1
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Fricke SN, Haber S, Hua M, Salgado M, Helms BA, Reimer JA. Magnetic resonance insights into the heterogeneous, fractal-like kinetics of chemically recyclable polymers. Sci Adv 2024; 10:eadl0568. [PMID: 38569038 PMCID: PMC10990270 DOI: 10.1126/sciadv.adl0568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 02/28/2024] [Indexed: 04/05/2024]
Abstract
Moving toward a circular plastics economy is a vital aspect of global resource management. Chemical recycling of plastics ensures that high-value monomers can be recovered from depolymerized plastic waste, thus enabling circular manufacturing. However, to increase chemical recycling throughput in materials recovery facilities, the present understanding of polymer transport, diffusion, swelling, and heterogeneous deconstruction kinetics must be systematized to allow industrial-scale process design, spanning molecular to macroscopic regimes. To develop a framework for designing depolymerization processes, we examined acidolysis of circular polydiketoenamine elastomers. We used magnetic resonance to monitor spatially resolved observables in situ and then evaluated these data with a fractal method that treats nonlinear depolymerization kinetics. This approach delineated the roles played by network architecture and reaction medium on depolymerization outcomes, yielding parameters that facilitate comparisons between bulk processes. These streamlined methods to investigate polymer hydrolysis kinetics portend a general strategy for implementing chemical recycling on an industrial scale.
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Affiliation(s)
- Sophia N. Fricke
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Shira Haber
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Mutian Hua
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Mia Salgado
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Brett A. Helms
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Jeffrey A. Reimer
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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2
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Neidhart EK, Hua M, Peng Z, Kearney LT, Bhat V, Vashahi F, Alexanian EJ, Sheiko SS, Wang C, Helms BA, Leibfarth FA. C-H Functionalization of Polyolefins to Access Reprocessable Polyolefin Thermosets. J Am Chem Soc 2023; 145:27450-27458. [PMID: 38079611 DOI: 10.1021/jacs.3c08682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Upcycling plastic waste into reprocessable materials with performance-advantaged properties would contribute to the development of a circular plastics economy. Here, we modify branched polyolefins and postconsumer polyethylene through a versatile C-H functionalization approach using thiosulfonates as a privileged radical group transfer functionality. Cross-linking the functionalized polyolefins with polytopic amines provided dynamically cross-linked polyolefin networks enabled by associative bond exchange of diketoenamine functionality. A combination of resonant soft X-ray scattering and grazing incidence X-ray scattering revealed hierarchical phase morphology in which diketoenamine-rich microdomains phase-separate within amorphous regions between polyolefin crystallites. The combination of dynamic covalent cross-links and microphase separation results in useful and improved mechanical properties, including a ∼4.5-fold increase in toughness, a reduction in creep deformation at temperatures relevant to use, and high-temperature structural stability compared to the parent polyolefin. The dynamic nature of diketoenamine cross-links provides stress relaxation at elevated temperatures, which enabled iterative reprocessing of the dynamic covalent polymer network with little cycle-to-cycle property fade. The ability to convert polyolefin waste into a reprocessable thermoformable material with attractive thermomechanical properties provides additional optionality for upcycling to enable future circularity.
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Affiliation(s)
- Eliza K Neidhart
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, United States
| | - Mutian Hua
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Zhengxing Peng
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Logan T Kearney
- Chemical Science Division, Oak Ridge National Lab, Oak Ridge, Tennessee 37830, United States
| | - Vittal Bhat
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, United States
| | - Foad Vashahi
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, United States
| | - Erik J Alexanian
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, United States
| | - Sergei S Sheiko
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, United States
| | - Cheng Wang
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Brett A Helms
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Frank A Leibfarth
- Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27514, United States
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3
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Ciccia NR, Shi JX, Pal S, Hua M, Malollari KG, Lizandara-Pueyo C, Risto E, Ernst M, Helms BA, Messersmith PB, Hartwig JF. Diverse functional polyethylenes by catalytic amination. Science 2023; 381:1433-1440. [PMID: 37769088 DOI: 10.1126/science.adg6093] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 08/28/2023] [Indexed: 09/30/2023]
Abstract
Functional polyethylenes possess valuable bulk and surface properties, but the limits of current synthetic methods narrow the range of accessible materials and prevent many envisioned applications. Instead, these materials are often used in composite films that are challenging to recycle. We report a Cu-catalyzed amination of polyethylenes to form mono- and bifunctional materials containing a series of polar groups and substituents. Designed catalysts with hydrophobic moieties enable the amination of linear and branched polyethylenes without chain scission or cross-linking, leading to polyethylenes with otherwise inaccessible combinations of functional groups and architectures. The resulting materials possess tunable bulk and surface properties, including toughness, adhesion to metal, paintability, and water solubility, which could unlock applications for functional polyethylenes and reduce the need for complex composites.
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Affiliation(s)
- Nicodemo R Ciccia
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
- Division of Chemical Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Jake X Shi
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
- Division of Chemical Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Subhajit Pal
- Departments of Materials Science and Engineering and Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Mutian Hua
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Katerina G Malollari
- Departments of Materials Science and Engineering and Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA
| | | | - Eugen Risto
- BASF SE, 67056 Ludwigshafen am Rhein, Germany
| | | | - Brett A Helms
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Phillip B Messersmith
- Departments of Materials Science and Engineering and Bioengineering, University of California, Berkeley, Berkeley, CA 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - John F Hartwig
- Department of Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA
- Division of Chemical Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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4
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Wu D, Yao B, Wu S, Hingorani H, Cui Q, Hua M, Frenkel I, Du Y, Hsiai TK, He X. Room-Temperature Annealing-Free Gold Printing via Anion-Assisted Photochemical Deposition. Adv Mater 2022; 34:e2201772. [PMID: 35703311 PMCID: PMC9884391 DOI: 10.1002/adma.202201772] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 04/11/2022] [Indexed: 05/30/2023]
Abstract
Metal patterning via additive manufacturing has been phasing-in to broad applications in many medical, electronics, aerospace, and automotive industries. While previous efforts have produced various promising metal-patterning strategies, their complexity and high cost have limited their practical application in rapid production and prototyping. Herein, a one-step gold printing technique based on anion-assisted photochemical deposition (APD), which can directly print highly conductive gold patterns (1.08 × 107 S m-1 ) under ambient conditions without post-annealing treatment, is introduced. Uniquely, the APD uses specific ion effects with projection lithography to pattern Au nanoparticles and simultaneously sinter them into tunable porous gold structures. The significant influence of kosmotropic or chaotropic anions in the precursor ink on tuning the morphologies and conductivities of the printed patterns by employing a series of different ions, including Cl- ions, in the printing process is presented. Additionally, the resistance stabilities and the electrochemical properties of the APD-printed gold patterns are carefully investigated. The high conductivity and excellent conformability of the printed Au electrodes are demonstrated with reliable performance in electrophysiological signal delivery and acquisition for biomedical applications. This work exploits the potential of photochemical-deposition-based metal patterning in flexible electronic manufacturing.
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Affiliation(s)
- Dong Wu
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Bowen Yao
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Shuwang Wu
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Hardik Hingorani
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Qingyu Cui
- Department of Bioengineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Mutian Hua
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Imri Frenkel
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Yingjie Du
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Tzung K Hsiai
- Department of Bioengineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
| | - Ximin He
- Department of Materials Science and Engineering, University of California, Los Angeles (UCLA), Los Angeles, CA, 90095, USA
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5
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Bernhardt PA, Hua M, Bortnik J, Ma Q, Verronen PT, McCarthy MP, Hampton DL, Golkowski M, Cohen MB, Richardson DK, Howarth AD, James HG, Meredith NP. Active Precipitation of Radiation Belt Electrons Using Rocket Exhaust Driven Amplification (REDA) of Man-Made Whistlers. J Geophys Res Space Phys 2022; 127:e2022JA030358. [PMID: 35860435 PMCID: PMC9285445 DOI: 10.1029/2022ja030358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 04/27/2022] [Accepted: 05/16/2022] [Indexed: 06/15/2023]
Abstract
Ground-based very low frequency (VLF) transmitters located around the world generate signals that leak through the bottom side of the ionosphere in the form of whistler mode waves. Wave and particle measurements on satellites have observed that these man-made VLF waves can be strong enough to scatter trapped energetic electrons into low pitch angle orbits, causing loss by absorption in the lower atmosphere. This precipitation loss process is greatly enhanced by intentional amplification of the whistler waves using a newly discovered process called rocket exhaust driven amplification (REDA). Satellite measurements of REDA have shown between 30 and 50 dB intensification of VLF waves in space using a 60 s burn of the 150 g/s thruster on the Cygnus satellite that services the International Space Station. This controlled amplification process is adequate to deplete the energetic particle population on the affected field lines in a few minutes rather than the multi-day period it would take naturally. Numerical simulations of the pitch angle diffusion for radiation belt particles use the UCLA quasi-linear Fokker Planck model to assess the impact of REDA on radiation belt remediation of newly injected energetic electrons. The simulated precipitation fluxes of energetic electrons are applied to models of D-region electron density and bremsstrahlung X-rays for predictions of the modified environment that can be observed with satellite and ground-based sensors.
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Affiliation(s)
| | - M. Hua
- Department of Atmospheric and Oceanography ScienceUCLALos AngelesCAUSA
| | - J. Bortnik
- Department of Atmospheric and Oceanography ScienceUCLALos AngelesCAUSA
| | - Q. Ma
- Department of Atmospheric and Oceanography ScienceUCLALos AngelesCAUSA
- Center for Space PhysicsBoston UniversityBostonMAUSA
| | - P. T. Verronen
- Sodankylä Geophysical ObservatoryUniversity of OuluSodankyläFinland
- Space and Earth Observation CentreFinnish Meteorological InstituteHelsinkiFinland
| | - M. P. McCarthy
- Department of Earth and Space SciencesUniversity of WashingtonSeattleWAUSA
| | - D. L. Hampton
- Geophysical InstituteUniversity of AlaskaFairbanksAKUSA
| | - M. Golkowski
- Department of Electrical EngineeringUniversity of Colorado DenverDenverCOUSA
| | - M. B. Cohen
- School of Electrical and Computer EngineeringGeorgia Institute of TechnologyAtlantaGAUSA
| | - D. K. Richardson
- School of Electrical and Computer EngineeringGeorgia Institute of TechnologyAtlantaGAUSA
| | - A. D. Howarth
- Department of Physics and AstronomyUniversity of CalgaryCalgaryABCanada
| | - H. G. James
- Department of Physics and AstronomyUniversity of CalgaryCalgaryABCanada
| | - N. P. Meredith
- British Antarctic SurveyNatural Environment Research CouncilCambridgeUK
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Abstract
Hydrogels have gained tremendous attention due to their versatility in soft electronics, actuators, biomedical sensors, etc. Due to the high water content, hydrogels are usually soft, weak, and freeze below 0°C, which brings severe limitations to applications such as soft robotics and flexible electronics in harsh environments. Most existing anti-freezing gels suffer from poor mechanical properties and urgently need further improvements. Here, we took inspirations from tendon and coniferous trees and provided an effective method to strengthen polyvinyl alcohol (PVA) hydrogel while making it freeze resistant. The salting-out effect was utilized to create a hierarchically structured polymer network, which induced superior mechanical properties (Young's modulus: 10.1 MPa, tensile strength: 13.5 MPa, and toughness: 127.9 MJ/m3). Meanwhile, the cononsolvency effect was employed to preserve the structure and suppress the freezing point to -60°C. Moreover, we have demonstrated the broad applicability of our material by fabricating PVA hydrogel-based hydraulic actuators and ionic conductors.
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Affiliation(s)
- Sidi Duan
- Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Shuwang Wu
- Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Mutian Hua
- Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Dong Wu
- Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Yichen Yan
- Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Xinyuan Zhu
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Ximin He
- Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
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7
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Hua M, Wu S, Jin Y, Zhao Y, Yao B, He X. Tough-Hydrogel Reinforced Low-Tortuosity Conductive Networks for Stretchable and High-Performance Supercapacitors. Adv Mater 2021; 33:e2100983. [PMID: 34060153 DOI: 10.1002/adma.202100983] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/31/2021] [Indexed: 05/26/2023]
Abstract
All-solid-state supercapacitors are seeing emerging applications in flexible and stretchable electronics. Supercapacitors with high capacitance, high power density, simple form factor, and good mechanical robustness are highly desired, which demands electrode materials with high surface area, high mass loading, good conductivity, larger thickness, low tortuosity, and high toughness. However, it has been challenging to simultaneously realize them in a single material. By compositing a superficial layer of tough hydrogel on conductive and low tortuous foams, a thick capacitor electrode with large capacitance (5.25 F cm-2 ), high power density (41.28 mW cm-2 ), and good mechanical robustness (ε = 140%, Γ = 1000 J m-2 ) is achieved. The tough hydrogel serves as both a load-bearing layer to maintain structural integrity during deformation and a permeable binder to allow interaction between the conductive electrode and electrolyte. It is shown that the tough hydrogel reinforcement is beneficial for both electrical and mechanical stability. With a simple design and facile fabrication, this strategy is generalizable for various conductive materials.
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Affiliation(s)
- Mutian Hua
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Shuwang Wu
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Yin Jin
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Yusen Zhao
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Bowen Yao
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Ximin He
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
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8
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Liu XH, Liu LP, Xu XM, Hua M, Kang Q, Li A, Huang L. FOXN2 suppresses the proliferation and invasion of human hepatocellular carcinoma cells. Eur Rev Med Pharmacol Sci 2021; 25:731-737. [PMID: 33577027 DOI: 10.26355/eurrev_202101_24634] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
OBJECTIVE The aim of this study was to explore the roles of FOXN2 (Fork head Box N2) in mediating the proliferation and invasion of hepatocellular carcinoma (HCC) cells. PATIENTS AND METHODS Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was used to determine expression of FOXN2 in HCC tissues and cells. Transfection of plasmid containing FOXN2 was used to exogenously overexpress FOXN2 in vitro. Cell Counting Kit-8 (CCK-8) assay and transwell assay were applied to detect the proliferation and invasion of HCC cells, respectively. RESULTS FOXN2 expression decreased significantly in both HCC tissues and cells (p<0.05). Upregulation of FOXN2 significantly inhibited the proliferation and invasion of HCC cells (p<0.05). CONCLUSIONS FOXN2 acts as a regulator in the progression of HCC. Our findings suggest that FOXN2 may be a novel therapeutic monitoring and prognosis biomarker in HCC.
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Affiliation(s)
- X-H Liu
- Department of Oncology, Department of Hematology; The First Affiliated Hospital of Gannan Medical University, Ganzhou, China.
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9
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Alsaid Y, Wu S, Wu D, Du Y, Shi L, Khodambashi R, Rico R, Hua M, Yan Y, Zhao Y, Aukes D, He X. Tunable Sponge-Like Hierarchically Porous Hydrogels with Simultaneously Enhanced Diffusivity and Mechanical Properties. Adv Mater 2021; 33:e2008235. [PMID: 33829563 DOI: 10.1002/adma.202008235] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 02/07/2021] [Indexed: 06/12/2023]
Abstract
Crosslinked polymers and gels are important in soft robotics, solar vapor generation, energy storage, drug delivery, catalysis, and biosensing. However, their attractive mass transport and volume-changing abilities are diffusion-limited, requiring miniaturization to avoid slow response. Typical approaches to improving diffusion in hydrogels sacrifice mechanical properties by increasing porosity or limit the total volumetric flux by directionally confining the pores. Despite tremendous efforts, simultaneous enhancement of diffusion and mechanical properties remains a long-standing challenge hindering broader practical applications of hydrogels. In this work, cononsolvency photopolymerization is developed as a universal approach to overcome this swelling-mechanical property trade-off. The as-synthesized poly(N-isopropylacrylamide) hydrogel, as an exemplary system, presents a unique open porous network with continuous microchannels, leading to record-high volumetric (de)swelling speeds, almost an order of magnitude higher than reported previously. This swelling enhancement comes with a simultaneous improvement in Young's modulus and toughness over conventional hydrogels fabricated in pure solvents. The resulting fast mass transport enables in-air operation of the hydrogel via rapid water replenishment and ultrafast actuation. The method is compatible with 3D printing. The generalizability is demonstrated by extending the technique to poly(N-tertbutylacrylamide-co-polyacrylamide) and polyacrylamide hydrogels, non-temperature-responsive polymer systems, validating the present hypothesis that cononsolvency is a generic phenomenon driven by competitive adsorption.
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Affiliation(s)
- Yousif Alsaid
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90 095, USA
| | - Shuwang Wu
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90 095, USA
| | - Dong Wu
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90 095, USA
| | - Yingjie Du
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90 095, USA
| | - Lingxia Shi
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90 095, USA
| | - Roozbeh Khodambashi
- The Polytechnic School, Fulton School of Engineering, Arizona State University, Mesa, AZ, 85 212, USA
| | - Rossana Rico
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90 095, USA
| | - Mutian Hua
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90 095, USA
| | - Yichen Yan
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90 095, USA
| | - Yusen Zhao
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90 095, USA
| | - Daniel Aukes
- The Polytechnic School, Fulton School of Engineering, Arizona State University, Mesa, AZ, 85 212, USA
| | - Ximin He
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90 095, USA
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10
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Abstract
Hydrogels with attractive stimuli-responsive volume changing abilities are seeing emerging applications as soft actuators and robots. However, many hydrogels are intrinsically soft and fragile for tolerating mechanical damage in real world applications and could not deliver high actuation force because of the mechanical weakness of the porous polymer network. Conventional tough hydrogels, fabricated by forming double networks, dual cross-linking, and compositing, could not satisfy both high toughness and high stimuli responsiveness. Herein, we present a material design of combining responsive and tough components in a single hydrogel network, which enables the synergistic realization of high toughness and actuation performance. We showcased this material design in an exemplary tough and thermally responsive hydrogel based on PVA/(PVA-MA)-g-PNIPAM, which achieved 100 times higher toughness (∼10 MJ/m3) and 20 times higher actuation stress (∼10 kPa) compared to conventional PNIPAM hydrogels, and a contraction ratio of up to 50% simultaneously. The effects of salt concentration, polymer ratio, and structural design on the mechanical and actuation properties have been systematically investigated. Utilizing 4D printing, actuators of various geometries were fabricated, as well as lattice-architected hydrogels with macro-voids, presenting 4 times faster actuation speed compared to bulk hydrogel, in addition to the high toughness, actuation force, and contraction ratio.
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Affiliation(s)
- Mutian Hua
- Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, California 90095 United States
| | - Dong Wu
- Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, California 90095 United States
| | - Shuwang Wu
- Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, California 90095 United States
| | - Yanfei Ma
- Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, California 90095 United States
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Yousif Alsaid
- Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, California 90095 United States
| | - Ximin He
- Department of Materials Science and Engineering, University of California Los Angeles, Los Angeles, California 90095 United States
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11
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Wu S, Hua M, Alsaid Y, Du Y, Ma Y, Zhao Y, Lo CY, Wang C, Wu D, Yao B, Strzalka J, Zhou H, Zhu X, He X. Poly(vinyl alcohol) Hydrogels with Broad-Range Tunable Mechanical Properties via the Hofmeister Effect. Adv Mater 2021; 33:e2007829. [PMID: 33554414 DOI: 10.1002/adma.202007829] [Citation(s) in RCA: 145] [Impact Index Per Article: 48.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/28/2020] [Indexed: 05/26/2023]
Abstract
Hydrogels, exhibiting wide applications in soft robotics, tissue engineering, implantable electronics, etc., often require sophisticately tailoring of the hydrogel mechanical properties to meet specific demands. For examples, soft robotics necessitates tough hydrogels; stem cell culturing demands various tissue-matching modulus; and neuron probes desire dynamically tunable modulus. Herein, a strategy to broadly alter the mechanical properties of hydrogels reversibly via tuning the aggregation states of the polymer chains by ions based on the Hofmeister effect is reported. An ultratough poly(vinyl alcohol) (PVA) hydrogel as an exemplary material (toughness 150 ± 20 MJ m-3 ), which surpasses synthetic polymers like poly(dimethylsiloxane), synthetic rubber, and natural spider silk is fabricated. With various ions, the hydrogel's various mechanical properties are continuously and reversibly in situ modulated over a large window: tensile strength from 50 ± 9 kPa to 15 ± 1 MPa, toughness from 0.0167 ± 0.003 to 150 ± 20 MJ m-3 , elongation from 300 ± 100% to 2100 ± 300%, and modulus from 24 ± 2 to 2500 ± 140 kPa. Importantly, the ions serve as gelation triggers and property modulators only, not necessarily required to remain in the gel, maintaining the high biocompatibility of PVA without excess ions. This strategy, enabling high mechanical performance and broad dynamic tunability, presents a universal platform for broad applications from biomedicine to wearable electronics.
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Affiliation(s)
- Shuwang Wu
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Mutian Hua
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Yousif Alsaid
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Yingjie Du
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Yanfei Ma
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Yusen Zhao
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Chiao-Yueh Lo
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Canran Wang
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Dong Wu
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - Bowen Yao
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Joseph Strzalka
- X-Ray Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Hua Zhou
- X-Ray Science Division, Argonne National Laboratory, Argonne, IL, 60439, USA
| | - Xinyuan Zhu
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, China
| | - Ximin He
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA, 90095, USA
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12
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Niu W, Wang X, Zheng Y, Wu S, Hua M, Wang Y, Zhang X, Tok AIY, He X, Zhang S. Inorganic Photonic Microspheres with Localized Concentric Ordering for Deep Pattern Encoding and Triple Sensory Microsensor. Small 2020; 16:e2003638. [PMID: 33107169 DOI: 10.1002/smll.202003638] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 09/11/2020] [Indexed: 06/11/2023]
Abstract
Photonic microspheres offer building units with unique topological structures and specific optical functions for diverse applications. Here, a new class of inorganic photonic microspheres with superior robustness, optical and electrical properties is reported by introducing a unique localized concentric ordering architecture and chemical interaction, which further serve as building blocks for deep pattern encoding and multiple sensory optoelectronic devices. Benefiting from localized concentric ordering architecture, the resultant photonic microspheres demonstrate orientation- and angle-independent structural colors. Notably, the formation of well-combined lamellae inorganic layers by chemical interaction grants the microspheres superior mechanical robustness, excellent solvent resistance, thermal stability, and multiple optoelectronic properties simultaneously, rarely seen in previous reports. Owing to these merits, such microspheres are used to construct diverse encoded photonic patterns for anti-counterfeiting applications. Interestingly, cross-communication among neighboring microspheres creates complex photonic sub-patterns, which provide "fingerprint information" with deep encryption security. Moreover, a single photonic microsphere-based optoelectronic microsensor is demonstrated for the first time, which achieves appealing application for real-time health monitoring and safety warning toward triple environmental stimuli. This work not only provides a new kind of robust, multifunctional photonic material, but also opens a new avenue for their uses as complexed pattern encoding and multi-parametric sensing platforms.
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Affiliation(s)
- Wenbin Niu
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, West Campus, 2 Linggong Rd., Dalian, 116024, China
| | - Xiao Wang
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, West Campus, 2 Linggong Rd., Dalian, 116024, China
| | - Yu Zheng
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, West Campus, 2 Linggong Rd., Dalian, 116024, China
| | - Shuwang Wu
- Department of Materials Science and Engineering, University of California, Los Angeles, CA, 90095, USA
| | - Mutian Hua
- Department of Materials Science and Engineering, University of California, Los Angeles, CA, 90095, USA
| | - Yunpeng Wang
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, West Campus, 2 Linggong Rd., Dalian, 116024, China
| | - Xiaohe Zhang
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, West Campus, 2 Linggong Rd., Dalian, 116024, China
| | - Alfred Iing Yoong Tok
- School of Material Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore
| | - Ximin He
- Department of Materials Science and Engineering, University of California, Los Angeles, CA, 90095, USA
| | - Shufen Zhang
- State Key Laboratory of Fine Chemicals, Dalian University of Technology, West Campus, 2 Linggong Rd., Dalian, 116024, China
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13
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Ma Y, Hua M, Wu S, Du Y, Pei X, Zhu X, Zhou F, He X. Bioinspired high-power-density strong contractile hydrogel by programmable elastic recoil. Sci Adv 2020; 6:6/47/eabd2520. [PMID: 33208374 PMCID: PMC7673813 DOI: 10.1126/sciadv.abd2520] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/02/2020] [Indexed: 05/22/2023]
Abstract
Stimuli-responsive hydrogels have large deformability but-when applied as actuators, smart switch, and artificial muscles-suffer from low work density due to low deliverable forces (~2 kPa) and speed through the osmotic pressure-driven actuation. Inspired by the energy conversion mechanism of many creatures during jumping, we designed an elastic-driven strong contractile hydrogel through storing and releasing elastic potential energy in polymer network. It can generate high contractile force (40 kPa) rapidly at ultrahigh work density (15.3 kJ/m3), outperforming current hydrogels (~0.01 kJ/m3) and even biological muscles (~8 kJ/m3). This demonstrated elastic energy storing and releasing method endows hydrogels with elasticity-plasticity switchability, multi-stable deformability in fully reversible and programmable manners, and anisotropic or isotropic deformation. With the high power density and programmability via this customizable modular design, these hydrogels demonstrated potential for broad applications in artificial muscles, contractile wound dressing, and high-power actuators.
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Affiliation(s)
- Yanfei Ma
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
- Department of Material Science and Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mutian Hua
- Department of Material Science and Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Shuwang Wu
- Department of Material Science and Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Yingjie Du
- Department of Material Science and Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Xiaowei Pei
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China
| | - Xinyuan Zhu
- School of Chemistry and Chemical Engineering, State Key Laboratory of Metal Matrix Composites, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Feng Zhou
- State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
| | - Ximin He
- Department of Material Science and Engineering, University of California Los Angeles, Los Angeles, CA 90095, USA.
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14
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Liu Q, Hua M, Yan S, Zhang C, Wang R, Yang X, Han F, Hou M, Ma D. Immunorelated gene polymorphisms associated with acute myeloid leukemia. Clin Exp Immunol 2020; 201:266-278. [PMID: 32349161 PMCID: PMC7419888 DOI: 10.1111/cei.13446] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 04/14/2020] [Accepted: 04/23/2020] [Indexed: 12/11/2022] Open
Abstract
Although the pathogenesis of acute myeloid leukemia (AML) is still unknown, accumulating evidence has revealed that immune response plays a vital part in the pathogenesis. Here, we investigated the involvement of 21 single nucleotide polymorphisms (SNPs) of immunorelated genes, including cytokines [interleukin (IL)-2, IL-4, IL-9, IL-12A, IL-22, interferon (IFN-α) and transforming growth factor (TGF)-β1], transcriptional regulatory genes (TBX21, STAT1, STAT3, STAT5B, STAT6, GATA3, FOXP3 and IRF4) and others (IL2RA, IL6R, NFKBIA) in 269 AML in-patients and 200 healthy controls. Furthermore, we analyzed the relationship between the SNPs and clinical characteristics. Immunorelated SNP genotyping was performed on the Sequenom MassARRAY iPLEX platform. All the SNPs in healthy controls were consistent with Hardy-Weinberg equilibrium. All final P-values were adjusted by Bonferroni multiple testing. Our results showed that IL-22 (rs2227491) was significantly associated with the white blood cell (WBC) counts. Signal transducer and activator of transcription 5B (STAT-5B) (rs6503691) showed a close relationship with the recurrent genetic abnormalities in patients with AML. We verified the negatively independent effect of age and risk of cytogenetics on overall survival (OS). More importantly, the GG genotype of IL-12A (rs6887695) showed a negative impact on AML prognosis independently. Furthermore, the relative expression of IL-12 was decreased in GG genotype, no matter under a co-dominant or recessive model. However, no correlation was observed between the SNPs mentioned above and disease susceptibility, risk stratification and survival. Our findings suggest that immunorelated gene polymorphisms are associated with prognosis in AML, which may perform as novel inspection targets for AML patients.
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Affiliation(s)
- Q. Liu
- Department of HematologyQilu HospitalShandong UniversityJinanChina
- Department of HematologyQilu Hospital, Cheeloo College of MedicineShandong UniversityJinanChina
- Department of HematologyTaian Central HospitalTaianShandongChina
| | - M. Hua
- Department of HematologyQilu HospitalShandong UniversityJinanChina
| | - S. Yan
- Department of HematologyQilu HospitalShandong UniversityJinanChina
| | - C. Zhang
- Department of HematologyQilu HospitalShandong UniversityJinanChina
| | - R. Wang
- Department of HematologyQilu HospitalShandong UniversityJinanChina
| | - X. Yang
- Department of HematologyQilu HospitalShandong UniversityJinanChina
| | - F. Han
- Department of HematologyQilu HospitalShandong UniversityJinanChina
| | - M. Hou
- Department of HematologyQilu HospitalShandong UniversityJinanChina
| | - D. Ma
- Department of HematologyQilu HospitalShandong UniversityJinanChina
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15
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Wu D, Song J, Zhai Z, Hua M, Kim C, Frenkel I, Jiang H, He X. Visualizing Morphogenesis through Instability Formation in 4-D Printing. ACS Appl Mater Interfaces 2019; 11:47468-47475. [PMID: 31741387 DOI: 10.1021/acsami.9b19730] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Heterogeneous growth in a myriad of biological systems can lead to the formation of distinct morphologies during the maturation processes of different species. We demonstrate that the distinct circumferential buckling observed in pumpkins can be reproduced by a core-shell barrel structure using four-dimensional (4D) printing, taking advantage of digital light processing (DLP)-based three-dimensional (3D) printing and stimulus-responsive hydrogels. The mechanical mismatch between the stiff core and compliant shell results in buckling instability on the surface. The initiation and development of the buckling are governed by the ratio of core/shell radius, the ratio of core/shell swelling ratios, and the mismatch between the core and shell in stiffness. Furthermore, the rigid core not only acts as a source of circumferential confinement but also sets a boundary at the poles of the entire structure. The heterogeneous structures with controllable buckling geometrically and structurally behave much like plants' fruits. This replicates the biological morphologic change and elucidates the general mechanism and dynamics of the complex instability formation of heterogeneous 3D objects.
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Affiliation(s)
- Dong Wu
- Department of Materials Science and Engineering , University of California, Los Angeles (UCLA) , Los Angeles , California 90095 , United States
| | - Jiaqi Song
- Department of Materials Science and Engineering , University of California, Los Angeles (UCLA) , Los Angeles , California 90095 , United States
| | - Zirui Zhai
- School for Engineering of Matter, Transport and Energy , Arizona State University , Tempe , Arizona 85281 , United States
| | - Mutian Hua
- Department of Materials Science and Engineering , University of California, Los Angeles (UCLA) , Los Angeles , California 90095 , United States
| | - Cheolgyu Kim
- Department of Materials Science and Engineering , University of California, Los Angeles (UCLA) , Los Angeles , California 90095 , United States
| | - Imri Frenkel
- Department of Materials Science and Engineering , University of California, Los Angeles (UCLA) , Los Angeles , California 90095 , United States
| | - Hanqing Jiang
- School for Engineering of Matter, Transport and Energy , Arizona State University , Tempe , Arizona 85281 , United States
| | - Ximin He
- Department of Materials Science and Engineering , University of California, Los Angeles (UCLA) , Los Angeles , California 90095 , United States
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16
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Qian X, Zhao Y, Alsaid Y, Wang X, Hua M, Galy T, Gopalakrishna H, Yang Y, Cui J, Liu N, Marszewski M, Pilon L, Jiang H, He X. Artificial phototropism for omnidirectional tracking and harvesting of light. Nat Nanotechnol 2019; 14:1048-1055. [PMID: 31686005 DOI: 10.1038/s41565-019-0562-3] [Citation(s) in RCA: 78] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 09/19/2019] [Indexed: 05/19/2023]
Abstract
Many living organisms track light sources and halt their movement when alignment is achieved. This phenomenon, known as phototropism, occurs, for example, when plants self-orient to face the sun throughout the day. Although many artificial smart materials exhibit non-directional, nastic behaviour in response to an external stimulus, no synthetic material can intrinsically detect and accurately track the direction of the stimulus, that is, exhibit tropistic behaviour. Here we report an artificial phototropic system based on nanostructured stimuli-responsive polymers that can aim and align to the incident light direction in the three-dimensions over a broad temperature range. Such adaptive reconfiguration is realized through a built-in feedback loop rooted in the photothermal and mechanical properties of the material. This system is termed a sunflower-like biomimetic omnidirectional tracker (SunBOT). We show that an array of SunBOTs can, in principle, be used in solar vapour generation devices, as it achieves up to a 400% solar energy-harvesting enhancement over non-tropistic materials at oblique illumination angles. The principle behind our SunBOTs is universal and can be extended to many responsive materials and a broad range of stimuli.
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Affiliation(s)
- Xiaoshi Qian
- Department of Material Science and Engineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Yusen Zhao
- Department of Material Science and Engineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Yousif Alsaid
- Department of Material Science and Engineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Xu Wang
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, USA
| | - Mutian Hua
- Department of Material Science and Engineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Tiphaine Galy
- Department of Mechanical and Aerospace Engineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Hamsini Gopalakrishna
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, USA
| | - Yunyun Yang
- Department of Material Science and Engineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Jinsong Cui
- Department of Material Science and Engineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Ning Liu
- Department of Material Science and Engineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Michal Marszewski
- Department of Mechanical and Aerospace Engineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Laurent Pilon
- Department of Mechanical and Aerospace Engineering, University of California Los Angeles, Los Angeles, CA, USA
| | - Hanqing Jiang
- School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, USA
| | - Ximin He
- Department of Material Science and Engineering, University of California Los Angeles, Los Angeles, CA, USA.
- California Nanosystems Institute, Los Angeles, CA, USA.
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17
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Zhao Y, Xuan C, Qian X, Alsaid Y, Hua M, Jin L, He X. Soft phototactic swimmer based on self-sustained hydrogel oscillator. Sci Robot 2019; 4:4/33/eaax7112. [PMID: 33137784 DOI: 10.1126/scirobotics.aax7112] [Citation(s) in RCA: 134] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 07/29/2019] [Indexed: 01/27/2023]
Abstract
Oscillations are widely found in living organisms to generate propulsion-based locomotion often driven by constant ambient conditions, such as phototactic movements. Such environment-powered and environment-directed locomotions may advance fully autonomous remotely steered robots. However, most man-made oscillations require nonconstant energy input and cannot perform environment-dictated movement. Here, we report a self-sustained soft oscillator that exhibits perpetual and untethered locomotion as a phototactic soft swimming robot, remotely fueled and steered by constant visible light. This particular out-of-equilibrium actuation arises from a self-shadowing-enabled negative feedback loop inherent in the dynamic light-material interactions, promoted by the fast and substantial volume change of the photoresponsive hydrogel. Our analytical model and governing equation unveil the oscillation mechanism and design principle with key parameters identified to tune the dynamics. On this autonomous oscillator platform, we establish a broadly applicable principle for converting a continuous input into a discontinuous output. The modular design can be customized to accommodate various forms of input energy and to generate diverse oscillatory behaviors. The hydrogel oscillator showcases agile life-like omnidirectional motion in the entire three-dimensional space with near-infinite degrees of freedom. The large force generated by the powerful and long-lasting oscillation can sufficiently overcome water damping and effectively self-propel away from a light source. Such a hydrogel oscillator-based all-soft swimming robot, named OsciBot, demonstrated high-speed and controllable phototactic locomotion. This autonomous robot is battery free, deployable, scalable, and integratable. Artificial phototaxis opens broad opportunities in maneuverable marine automated systems, miniaturized transportation, and solar sails.
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Affiliation(s)
- Yusen Zhao
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Chen Xuan
- Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Xiaoshi Qian
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Yousif Alsaid
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Mutian Hua
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Lihua Jin
- Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Ximin He
- Department of Materials Science and Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA. .,California NanoSystems Institute, Los Angeles, CA 90095, USA
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18
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Zhang L, Yu W, Pan X, Fang J, Hua M, Chen F, Jiang J. Thermal hazard assessment for synthesis of 3-methylpyridine-N-oxide. J Loss Prev Process Ind 2015. [DOI: 10.1016/j.jlp.2015.03.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Li W, Kong QY, Zhao CF, Zhao F, Li FH, Xia W, Wang R, Hu YM, Hua M. Adrenomedullin and adrenotensin regulate collagen synthesis and proliferation in pulmonary arterial smooth muscle cells. Braz J Med Biol Res 2013; 46:1047-1055. [PMID: 24345914 PMCID: PMC3935277 DOI: 10.1590/1414-431x20132882] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 07/29/2013] [Indexed: 11/22/2022] Open
Abstract
To understand the pathophysiological mechanisms of pulmonary arterial smooth muscle cell (PASMC) proliferation and extracellular-matrix accumulation in the development of pulmonary hypertension and remodeling, this study determined the effects of different doses of adrenomedullin (ADM) and adrenotensin (ADT) on PASMC proliferation and collagen synthesis. The objective was to investigate whether extracellular signal-regulated kinase (ERK1/2) signaling was involved in ADM- and ADT-stimulated proliferation of PASMCs in 4-week-old male Wistar rats (body weight: 100-150 g, n=10). The proliferation of PASMCs was examined by 5-bromo-2-deoxyuridine incorporation. A cell growth curve was generated by the Cell Counting Kit-8 method. Expression of collagen I, collagen III, and phosphorylated ERK1/2 (p-ERK1/2) was evaluated by immunofluorescence. The effects of different concentrations of ADM and ADT on collagen I, collagen III, and p-ERK1/2 protein expression were determined by immunoblotting. We also investigated the effect of PD98059 inhibition on the expression of p-ERK1/2 protein by immunoblotting. ADM dose-dependently decreased cell proliferation, whereas ADT dose-dependently increased it; and ADM and ADT inhibited each other with respect to their effects on the proliferation of PASMCs. Consistent with these results, the expression of collagen I, collagen III, and p-ERK1/2 in rat PASMCs decreased after exposure to ADM but was upregulated after exposure to ADT. PD98059 significantly inhibited the downregulation by ADM and the upregulation by ADT of p-ERK1/2 expression. We conclude that ADM inhibited, and ADT stimulated, ERK1/2 signaling in rat PASMCs to regulate cell proliferation and collagen expression.
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Affiliation(s)
- W Li
- Shandong University, Biomedical Engineering Institute, School of Control Science and Engineering, JinanShandong, China
| | - Q Y Kong
- Shandong University, Qilu Hospital, Department of Pediatrics, JinanShandong, China
| | - C F Zhao
- Shandong University, Qilu Hospital, Department of Pediatrics, JinanShandong, China
| | - F Zhao
- Weill Medical College of Cornell University, Department of Medicine, New YorkNY, USA
| | - F H Li
- Shandong University, Qilu Hospital, Department of Pediatrics, JinanShandong, China
| | - W Xia
- Shandong University, Qilu Hospital, Department of Pediatrics, JinanShandong, China
| | - R Wang
- Shandong University, Qilu Hospital, Key Laboratory of Cardiovascular Remodeling and Function Research, JinanShandong, China
| | - Y M Hu
- Shandong University, Biomedical Engineering Institute, School of Control Science and Engineering, JinanShandong, China
| | - M Hua
- Shandong Institute of Scientific and Technical Information, JinanShandong, China
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20
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Aaberg-Jessen C, Fogh L, Halle B, Jensen V, Brunner N, Kristensen BW, Abe T, Momii Y, Watanabe J, Morisaki I, Natsume A, Wakabayashi T, Fujiki M, Aldaz B, Fabius AWM, Silber J, Harinath G, Chan TA, Huse JT, Anai S, Hide T, Nakamura H, Makino K, Yano S, Kuratsu JI, Balyasnikova IV, Prasol MS, Kanoija DK, Aboody KS, Lesniak MS, Barone T, Burkhart C, Purmal A, Gudkov A, Gurova K, Plunkett R, Barton K, Misuraca K, Cordero F, Dobrikova E, Min H, Gromeier M, Kirsch D, Becher O, Pont LB, Kloezeman J, van den Bent M, Kanaar R, Kremer A, Swagemakers S, French P, Dirven C, Lamfers M, Leenstra S, Pont LB, Balvers R, Kloezeman J, Kleijn A, Lawler S, Leenstra S, Dirven C, Lamfers M, Gong X, Andres A, Hanson J, Delashaw J, Bota D, Chen CC, Yao NW, Chuang WJ, Chang C, Chen PY, Huang CY, Wei KC, Cheng Y, Dai Q, Morshed R, Han Y, Auffinger B, Wainwright D, Zhang L, Tobias A, Rincon E, Thaci B, Ahmed A, He C, Lesniak M, Choi YA, Pandya H, Gibo DM, Fokt I, Priebe W, Debinski W, Chornenkyy Y, Agnihotri S, Buczkowicz P, Rakopoulos P, Morrison A, Barszczyk M, Becher O, Hawkins C, Chung S, Decollogne S, Luk P, Shen H, Ha W, Day B, Stringer B, Hogg P, Dilda P, McDonald K, Moore S, Hayden-Gephart M, Bergen J, Su Y, Rayburn H, Edwards M, Scott M, Cochran J, Das A, Varma AK, Wallace GC, Dixon-Mah YN, Vandergrift WA, Giglio P, Ray SK, Patel SJ, Banik NL, Dasgupta T, Olow A, Yang X, Mueller S, Prados M, James CD, Haas-Kogan D, Dave ND, Desai PB, Gudelsky GA, Chow LML, LaSance K, Qi X, Driscoll J, Driscoll J, Ebsworth K, Walters MJ, Ertl LS, Wang Y, Berahovic RD, McMahon J, Powers JP, Jaen JC, Schall TJ, Eroglu Z, Portnow J, Sacramento A, Garcia E, Raubitschek A, Synold T, Esaki S, Rabkin S, Martuza R, Wakimoto H, Ferluga S, Tome CL, Debinski W, Forde HE, Netland IA, Sleire L, Skeie B, Enger PO, Goplen D, Giladi M, Tichon A, Schneiderman R, Porat Y, Munster M, Dishon M, Weinberg U, Kirson E, Wasserman Y, Palti Y, Giladi M, Porat Y, Schneiderman R, Munster M, Weinberg U, Kirson E, Palti Y, Gramatzki D, Staudinger M, Frei K, Peipp M, Weller M, Grasso C, Liu L, Becher O, Berlow N, Davis L, Fouladi M, Gajjar A, Hawkins C, Huang E, Hulleman E, Hutt M, Keller C, Li XN, Meltzer P, Quezado M, Quist M, Raabe E, Spellman P, Truffaux N, van Vurden D, Wang N, Warren K, Pal R, Grill J, Monje M, Green AL, Ramkissoon S, McCauley D, Jones K, Perry JA, Ramkissoon L, Maire C, Shacham S, Ligon KL, Kung AL, Zielinska-Chomej K, Grozman V, Tu J, Viktorsson K, Lewensohn R, Gupta S, Mladek A, Bakken K, Carlson B, Boakye-Agyeman F, Kizilbash S, Schroeder M, Reid J, Sarkaria J, Hadaczek P, Ozawa T, Soroceanu L, Yoshida Y, Matlaf L, Singer E, Fiallos E, James CD, Cobbs CS, Hashizume R, Tom M, Ihara Y, Ozawa T, Santos R, Torre JDL, Lepe E, Waldman T, Prados M, James D, Hashizume R, Ihara Y, Huang X, Yu-Jen L, Tom M, Mueller S, Gupta N, Solomon D, Waldman T, Zhang Z, James D, Hayashi T, Adachi K, Nagahisa S, Hasegawa M, Hirose Y, Gephart MH, Moore S, Bergen J, Su YS, Rayburn H, Scott M, Cochran J, Hingtgen S, Kasmieh R, Nesterenko I, Figueiredo JL, Dash R, Sarkar D, Fisher P, Shah K, Horne E, Diaz P, Stella N, Huang C, Yang H, Wei K, Huang T, Hlavaty J, Ostertag D, Espinoza FL, Martin B, Petznek H, Rodriguez-Aguirre M, Ibanez C, Kasahara N, Gunzburg W, Gruber H, Pertschuk D, Jolly D, Robbins J, Hurwitz B, Yoo JY, Bolyard C, Yu JG, Wojton J, Zhang J, Bailey Z, Eaves D, Cripe T, Old M, Kaur B, Serwer L, Yoshida Y, Le Moan N, Santos R, Ng S, Butowski N, Krtolica A, Ozawa T, Cary SPL, James CD, Johns T, Greenall S, Donoghue J, Adams T, Karpel-Massler G, Westhoff MA, Kast RE, Dwucet A, Wirtz CR, Debatin KM, Halatsch ME, Karpel-Massler G, Kast RE, Westhoff MA, Merkur N, Dwucet A, Wirtz CR, Debatin KM, Halatsch ME, Kievit F, Stephen Z, Wang K, Kolstoe D, Silber J, Ellenbogen R, Zhang M, Kitange G, Schroeder M, Sarkaria J, Kleijn A, Haefner E, Leenstra S, Dirven C, Lamfers M, Knubel K, Pernu BM, Sufit A, Pierce AM, Nelson SK, Keating AK, Jensen SS, Kristensen BW, Lachowicz J, Demeule M, Regina A, Tripathy S, Curry JC, Nguyen T, Castaigne JP, Le Moan N, Serwer L, Yoshida Y, Ng S, Davis T, Santos R, Davis A, Tanaka K, Keating T, Getz J, Kapp GT, Romero JM, Ozawa T, James CD, Krtolica A, Cary SPL, Lee S, Ramisetti S, Slagle-Webb B, Sharma A, Connor J, Lee WS, Maire C, Kluk M, Aster JC, Ligon K, Sun S, Lee D, Ho ASW, Pu JKS, Zhang ZQ, Lee NP, Day PJR, Leung GKK, Liu Z, Liu X, Madhankumar AB, Miller P, Webb B, Connor JR, Yang QX, Lobo M, Green S, Schabel M, Gillespie Y, Woltjer R, Pike M, Lu YJ, Torre JDL, Waldman T, Prados M, Ozawa T, James D, Luchman HA, Stechishin O, Nguyen S, Cairncross JG, Weiss S, Lun X, Wells JC, Hao X, Zhang J, Grinshtein N, Kaplan D, Luchman A, Weiss S, Cairncross JG, Senger D, Robbins S, Madhankumar A, Slagle-Webb B, Rizk E, Payne R, Park A, Pang M, Harbaugh K, Connor J, Wilisch-Neumann A, Pachow D, Kirches E, Mawrin C, McDonell S, Liang J, Piao Y, Nguyen N, Yung A, Verhaak R, Sulman E, Stephan C, Lang F, de Groot J, Mizobuchi Y, Okazaki T, Kageji T, Kuwayama K, Kitazato KT, Mure H, Hara K, Morigaki R, Matsuzaki K, Nakajima K, Nagahiro S, Kumala S, Heravi M, Devic S, Muanza T, Nelson SK, Knubel KH, Pernu BM, Pierce AM, Keating AK, Neuwelt A, Nguyen T, Wu YJ, Donson A, Vibhakar R, Venkatamaran S, Amani V, Neuwelt E, Rapkin L, Foreman N, Ibrahim F, New P, Cui K, Zhao H, Chow D, Stephen W, Nozue-Okada K, Nagane M, McDonald KL, Ogawa D, Chiocca E, Godlewski J, Ozawa T, Yoshida Y, Santos R, James D, Pang M, Liu X, Madhankumar AB, Slagle-Webb B, Patel A, Miller P, Connor J, Pasupuleti N, Gorin F, Valenzuela A, Leon L, Carraway K, Ramachandran C, Nair S, Quirrin KW, Khatib Z, Escalon E, Melnick S, Phillips A, Boghaert E, Vaidya K, Ansell P, Shalinsky D, Zhang Y, Voorbach M, Mudd S, Holen K, Humerickhouse R, Reilly E, Huang T, Parab S, Diago O, Espinoza FL, Martin B, Ibanez C, Kasahara N, Gruber H, Pertschuk D, Jolly D, Robbins J, Ryken T, Agarwal S, Al-Keilani M, Alqudah M, Sibenaller Z, Assemolt M, Sai K, Li WY, Li WP, Chen ZP, Saito R, Sonoda Y, Kanamori M, Yamashita Y, Kumabe T, Tominaga T, Sarkar G, Curran G, Jenkins R, Scharnweber R, Kato Y, Lin J, Everson R, Soto H, Kruse C, Kasahara N, Liau L, Prins R, Semenkow S, Chu Q, Eberhart C, Sengupta R, Marassa J, Piwnica-Worms D, Rubin J, Serwer L, Kapp GT, Le Moan N, Yoshida Y, Romero JM, Ng S, Davis A, Ozawa T, Krtolica A, James CD, Cary SPL, Shai R, Pismenyuk T, Moshe I, Fisher T, Freedman S, Simon A, Amariglio N, Rechavi G, Toren A, Yalon M, Shen H, Decollogne S, Dilda P, Chung S, Luk P, Hogg P, McDonald K, Shimazu Y, Kurozumi K, Ichikawa T, Fujii K, Onishi M, Ishida J, Oka T, Watanabe M, Nasu Y, Kumon H, Date I, Sirianni RW, McCall RL, Spoor J, van der Kaaij M, Kloezeman J, Geurtjens M, Dirven C, Lamfers M, Leenstra S, Stephen Z, Veiseh O, Kievit F, Fang C, Leung M, Ellenbogen R, Silber J, Zhang M, Strohbehn G, Atsina KK, Patel T, Piepmeier J, Zhou J, Saltzman WM, Takahashi M, Valdes G, Inagaki A, Kamijima S, Hiraoka K, Micewicz E, McBride WH, Iwamoto KS, Gruber HE, Robbins JM, Jolly DJ, Kasahara N, Warren K, McCully C, Bacher J, Thomas T, Murphy R, Steffen-Smith E, McAllister R, Pastakia D, Widemann B, Wei K, Yang H, Huang C, Chen P, Hua M, Liu H, Woolf EC, Abdelwahab MG, Fenton KE, Liu Q, Turner G, Preul MC, Scheck AC, Yoshida Y, Ozawa T, Butowski N, Shen W, Brown D, Pedersen H, James D, Zhang J, Hariono S, Yao TW, Sidhu A, Hashizume R, James CD, Weiss WA, Nicolaides TP, Olusanya T. EXPERIMENTAL THERAPEUTICS AND PHARMACOLOGY. Neuro Oncol 2013; 15:iii37-iii61. [PMCID: PMC3823891 DOI: 10.1093/neuonc/not176] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/21/2023] Open
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Ding H, Liu Q, Hua M, Ding M, Du H, Zhang W, Li Z, Zhang J. Associations between Vascular Endothelial Growth Factor Gene Polymorphisms and Susceptibility to Acute Mountain Sickness. J Int Med Res 2012; 40:2135-44. [PMID: 23321170 DOI: 10.1177/030006051204000611] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Objective: This study investigated associations between polymorphisms in the vascular endothelial growth factor (VEGF) gene and susceptibility to acute mountain sickness. Methods: Two hundred Han Chinese soldiers who developed acute mountain sickness after rapidly ascending to an altitude of < 3600 m and 200 control soldiers (who did not develop the condition) were enrolled in the study. Twelve single nucleotide polymorphisms (SNPs) of the VEGF gene were genotyped in all the study participants. Plasma VEGF concentrations were measured by enzyme-linked immunosorbent assay in 40 subjects with acute mountain sickness and 40 controls before and after exposure to high altitude. Results: The frequencies of the rs3025039 genotype and allele were significantly different between the groups. Two SNPs, rs3025039 (which involves a C→T allele variation at position 936 in the 3′ untranslated region) and rs3025030 (which involves a G→C allele variation in the intronic sequence), were associated with a decreased risk of acute mountain sickness. Conclusion: The SNPs rs3025039 and rs3025030 of the VEGF gene may be associated with a decreased risk of acute mountain sickness development.
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Affiliation(s)
- H Ding
- Department of Respiratory Diseases, General Hospital of Chinese People's Armed Police Forces, Beijing, China
| | - Q Liu
- Department of Paediatrics, General Hospital of Chinese People's Armed Police Forces, Beijing, China
| | - M Hua
- Department of Respiratory Diseases, General Hospital of Chinese People's Armed Police Forces, Beijing, China
| | - M Ding
- Department of Respiratory Diseases, General Hospital of Chinese People's Armed Police Forces, Beijing, China
| | - H Du
- Department of Respiratory Diseases, General Hospital of Chinese People's Armed Police Forces, Beijing, China
| | - W Zhang
- Centres for Disease Control of Chinese People's Armed Police Forces, Beijing, China
| | - Z Li
- Centres for Disease Control of Chinese People's Armed Police Forces, Beijing, China
| | - J Zhang
- Department of Respiratory Diseases, General Hospital of Chinese People's Armed Police Forces, Beijing, China
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Luo ZW, He F, Fan HY, Wang XH, Hua M, Hu FC, Li XH, Liu ZX, Yu NT. First Report of Leaf Spot Disease Caused by Exserohilum rostratum on Pineapple in Hainan Province, China. Plant Dis 2012; 96:458. [PMID: 30727118 DOI: 10.1094/pdis-11-11-0979] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Pineapple (Ananas comosus (L.) Merr.) is an important perennial monocotyledonous plant that serves as an important fruit crop globally and is also produced in the Hainan Province of China where production in 2009 was 296,600 t. In July 2009, atypical symptoms of a leaf spot disease were observed on mature pineapple leaves in Chengmai County; approximately 15% of plants propagated from suckers became symptomatic after 150 to 300 days, eventually causing a 3 to 10% yield loss. In the initial infection stage, grayish white-to-yellowish white spots emerged on the leaf surfaces that ranged from 1.0 to 2.4 × 0.3 to 0.7 cm; black specks were not always present in the spots. Leaf spots also had distinctive light brown-to-reddish brown banding pattern on the edges. Several spots would often merge to form large lesions, 6.5 to 15.4 × 2.5 to 5.6 cm, covering more than 67% of the leaf surface, which can lead to death of the plant. Infected pineapple leaves collected from an orchard of Chengmai County were surface sterilized (75% ethanol for 30 s, 0.1% HgCl2 for 2 min, and rinsed three times in sterile distilled water). Leaf pieces were placed on potato dextrose agar medium and then incubated at 25°C. The emerging fungal colonies were grayish white to brown. Similar strains were obtained from Qionghai City and Wanning City subsequently. Two isolates, ITF0706-1 and ITF0706-2, were used in confirmation of the identity of the pathogen and in pathogenicity tests. Colonies were fast growing (more than 15 mm per day at 25 to 30°C) with dense aerial mycelia. Conidia were fusiform, pyriform to oval or cylindrical, olive brown to dark brown, 3 to 10 septate (typically 5 to 8), 33.2 to 102.5 × 9.0 to 21.3 μm, with a strongly protruding hilum bulged from the basal cell, which were similar to the Type A conidia described by Lin et al. (3). The strains were subjected to PCR amplification of the internal transcribed spacer (ITS)1-5.8S-ITS2 regions with universal primer pair ITS1/ITS4. The ITS sequence comparisons (GenBank Accession Nos. JN711431 and JN711432) shared between 99.60 and 99.83% identity with the isolate CATAS-ER01 (GenBank Accession No. GQ169762). According to morphological and molecular analysis, the two strains were identified as Exserohilum rostratum (Drechs.) Leonard & Suggs. Pathogenicity experiments were conducted five times and carried out by spraying a conidial suspension (105 CFU/ml) on newly matured leaves of healthy pineapple plants; plants sprayed with sterile water served as the negative control. Plants were incubated in the growth chamber at 20 to 25°C. Symptoms of leaf spot developed on test plants 7 days after inoculation while the control plants remained asymptomatic. Koch's postulates were fulfilled with the reisolation of the two fungal strains. Currently, E. rostratum is one of the most common pathogens on Bromeliads in Florida (2) and has been reported on Zea mays (4), Musa paradisiacal (3), and Calathea picturata (1) in China, but to our knowledge, this is the first report of leaf spot disease caused by E. rostratum on pineapple in Hainan Province of P.R. China. References: (1) L. L. Chern et al. Plant Dis. 95:1033, 2011. (2) R. M. Leahy. Plant Pathol. Circ. No. 393. Florida Department of Agriculture and Consumer Services Division of Plant Industry, 1999. (3) S. H. Lin et al. Australas. Plant Pathol. 40:246, 2011. (4) J. N. Tsai et al. Plant Pathol. Bull. 10:181, 2001.
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Affiliation(s)
- Z W Luo
- Institute of Tropical Fruit Tree, Hainan Academy of Agricultural Science; Haikou Investigation Station of Tropical Fruit Trees, Ministry of Agriculture, Haikou 571100, Hainan Province, P.R. China
| | - F He
- Institute of Tropical Fruit Tree, Hainan Academy of Agricultural Science; Haikou Investigation Station of Tropical Fruit Trees, Ministry of Agriculture, Haikou 571100, Hainan Province, P.R. China
| | - H Y Fan
- Institute of Tropical Fruit Tree, Hainan Academy of Agricultural Science; Haikou Investigation Station of Tropical Fruit Trees, Ministry of Agriculture, Haikou 571100, Hainan Province, P.R. China
| | - X H Wang
- Institute of Tropical Fruit Tree, Hainan Academy of Agricultural Science; Haikou Investigation Station of Tropical Fruit Trees, Ministry of Agriculture, Haikou 571100, Hainan Province, P.R. China
| | - M Hua
- Institute of Tropical Fruit Tree, Hainan Academy of Agricultural Science; Haikou Investigation Station of Tropical Fruit Trees, Ministry of Agriculture, Haikou 571100, Hainan Province, P.R. China
| | - F C Hu
- Institute of Tropical Fruit Tree, Hainan Academy of Agricultural Science; Haikou Investigation Station of Tropical Fruit Trees, Ministry of Agriculture, Haikou 571100, Hainan Province, P.R. China
| | - X H Li
- Institute of Tropical Fruit Tree, Hainan Academy of Agricultural Science; Haikou Investigation Station of Tropical Fruit Trees, Ministry of Agriculture, Haikou 571100, Hainan Province, P.R. China
| | - Z X Liu
- Institute of Tropical Bioscience and Biotechnology, China Academy of Tropical Agricultural Science, Haikou 571101, Hainan Province, P.R. China
| | - N T Yu
- Institute of Tropical Bioscience and Biotechnology, China Academy of Tropical Agricultural Science, Haikou 571101, Hainan Province, P.R. China
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Liu LM, Gao F, Hua M, Guan JY, Tang B, Li ZY. 266 THE SHORT TIME TREATMENT WITH SODIUM BUTYRATE ON GERMINAL VESICLE STAGE OOCYTES IMPROVES OOCYTE QUALITY AND DEVELOPMENTAL COMPETENCE IN PIGS. Reprod Fertil Dev 2011. [DOI: 10.1071/rdv23n1ab266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Oocyte maturation is a complex process during which the epigenetic modifications are dramatically changed, especially the histone acetylation and phosphorylation. Sodium butyrate (NaBu) is a histone deacetylase inhibitor that results in a more open structure of DNA. The aim of the present study was to analyse the role of NaBu in the meiosis of porcine oocytes and the subsequent embryonic developmental competence. Cumulus–oocyte complexes (COC) were collected from ovaries obtained at a local slaughterhouse. The COC were randomly divided into 3 groups and matured in vitro in medium (Hao et al. 2006) supplemented with 1 μM NaBu for 2 h [germinal vesicle (GV) stage, group 1] or for 22 h [GV to GV breakdown (GVBD) stage, group 2] or without treatment (control, group 3). After 44 h of in vitro maturation, the oocytes were denuded by 0.2% hyaluronidase, and oocytes with evenly dark ooplasm and visible first polar bodies were considered matured. The cortical granule distribution of matured oocytes was examined with immunostaining. The relative expression of CyclinB and Cdc2 of 3 group oocytes was determined with real-time PCR. Some matured oocytes from each group were collected and stimulated with electric pulse (2 direct current pulses of 1.2 kV cm–1 for 30 μs). The rate of parthenogenetic blastocyst was recorded, and cell number of each blastocyst was determined under an inverted fluorescence microscope after staining with 10 μg mL–1 of Hoechst 33342. The following results were found. 1) Compared with the control group (n = 70, 67.74 ± 1.64), oocyte maturation rates of group 1 and group 2 decreased significantly along with the extended treatments (n = 70, 59.57 ± 5.29 and 46.99 ± 1.22, respectively; P < 0.05). 2) The long time (22 h) treatment with NaBu inhibited the developmental competence (blastocyst rate) of oocytes (n = 30, 15.33 ± 3.47 v. 27.16 ± 2.10 P < 0.05), and the short time (2 h) treatment with NaBu on GV-stage oocytes inhibited the meiotic process slightly but improved the blastocyst rate (n = 30, 33.93 ± 2.51 v. 27.16 ± 2.10; P < 0.05). 3) The short time (2 h) treatment resulted in the migration of more cortical granules into the plasmasmic membrane and formed a monolayer with the membrane (compared with the control). 4) The exposure to NaBu from GV to GVBD stage induced the expression of the CyclinB and Cdc2 in the matured oocytes (4.68 ± 0.45 and 5.80 ± 0.58, respectively; P < 0.05) compared with the control. 5) Short time (2 h) exposure to NaBu on GV-stage oocytes inhibited the expression of the Cdc2 but increased the expression of the CylinB in the matured oocytes (0.43 ± 0.06 and 1.65 ± 0.26, respectively; P < 0.05) compared with the control. In conclusion, results of this study demonstrate that exposure to NaBu inhibits porcine oocyte meiosis in proportion to treatment length. However, a 2-h treatment with 1 μM NaBu improves oocyte developmental competence to the blastocyst stage. These results are useful for improving the developmental competent of oocytes for IVF and in vitro embryo production.
This work was supported by a grant (No. 2009CB941001) from the National Basic Research Program of China.
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Jiang Y, Zhao J, Hua M, Zhen X, Yan G, Hu Y, Sun H, Selvaggi L, Zannoni GF, Tagliaferri V, De Cicco S, Vellone VG, Romualdi D, Lanzone A, Guido M, Fassbender A, Vodolazkaia AV, Bossuyt XB, Kyama MK, Meuleman CM, Peeraer KP, Tomassetti CT, D'Hooghe TM, Lumini A, Nanni L, Manna C, Pappalardo S, Melin A, Lundholm C, Malki N, Swahn ML, Sparen P, Bergqvist A, Manna C, Crescenzi F, Farrag A, Sallam HN, Zou L, Ding G, Zhang R, Sheng J, Huang H, von Kleinsorgen C, Wilson T, Thiel-Moder U, Ebert AD, Reinfandt M, Papadopolous T, Melo AS, Rodrigues JK, Dib LA, Andrade AZ, Donabela FC, Ferriani RA, Navarro PA, Tocci A, Royo P, Lucchini C, Ramos P, Alcazar JL, Habara T, Terada S, Yoshioka N, Hayashi N, Haouzi D, Assou S, Monzo C, Anahory T, Dechaud H, De Vos J, Hamamah S, Gonzalez-Ramos R, Rojas C, Rocco J, Poch A, Sovino H, Kohen P, Munoz A, Devoto L, Aygen MA, Atakul T, Oner G, Ozgun MT, Sahin Y, Ozturk F, Li R, Qiao J, Zhylkova I, Feskov A, Feskova I, Somova O, Chumakova N, Bontekoe S, Blake D, Heineman MJ, Williams EC, Johnson NP, Motta A, Colaci D, Horton M, Faut M, Bisioli C, Kopcow L, de Zuniga I, Wiener-Megnazi Z, Khaytov M, Lahav - Baratz S, Shiloh H, Koifman M, Oslander R, Dirnfeld M, Sundqvist J, Andersson KL, Scarselli G, Gemzell-Danielsson K, Lalitkumar PGL, Tokushige N, Markham R, Crossett B, Ahn S, Nelaturi V, Khan A, Fraser IS, Van Vaerenbergh I, Fatemi HM, Blockeel C, Van Lommel L, In't Veld P, Schuit F, Kolibianakis EM, Devroey P, Bourgain C, Sugino N, Tamura I, Lee R, Maekawa R, Gelbaya T, Gordts S, D'Hooghe TN, Gergolet M, Nardo LG, Yu H, Wang H, Huang H, Lee C, Soong Y, Kremenska Y, Masliy Y, Goncharova Y, Kremenskoy M, Veselovskyy V, Zukin V, Sudoma I, Delgado-Rosas F, Gomez R, Tamarit S, Abad A, Simon C, Pellicer A, Racicot M, Dean NL, Antaki R, Menard S, Kadoch IJ, Garcia-Guzman R, Cabrera Romero L, Hernandez J, Palumbo A, Marshall E, Lowry J, Maybin JA, Collins F, Critchley HOD, Saunders PTK, Chaudhury K, Jana SK, Banerjee P, Mukherjee S, Chakravarty BN, Allegra A, Marino A, Lama A, Santoro A, Agueli C, Mazzola S, Volpes A, Delvoux B, de Graaff AA, D'Hooghe TM, Kyama CM, Dunselman GAJ, Romano A, Caccavo D, Pellegrino NM, Totaro I, Panzarino M, Nardelli C, Depalo R, Flores R, Montanana V, Monzo A, Polo P, Garcia-Gimeno T, Cabo A, Rubio JM, Pellicer A, de Graaff AA, Dunselman GAJ, Beets GL, van Lankveld JJ, Kim HY, Lee BS, Cho SH, Choi YS, Seo SK, Lee KE, Yang HI, Abubakirov A, Vacheyshvili T, Krechetova L, Ziganshina M, Demura T, Nazarenko T, Fulop I, Rucz A, Herczegh SZ, Ujvari A, Takacs SZ, Szakonyi T, Lopez - Muniz A, Zamora L, Serra O, Guix C, Lopez-Teijon M, Benadiva C, Alvarez JG, Goudakou M, Karkanaki A, Kalogeraki A, Mataliotakis I, Kalogiannidis I, Prapas I, Hosie M, Thomson KJ, Penny CB, Thomson KJ, Penny C, Hosie MJ, McKinnon B, Klaeser B, Bersinger N, Mueller MD, Horcajadas JA, Martinez-Conejero JA, Montesinos M, Morgan M, Fortuno S, Simon C, Pellicer A, Yi KW, Shin JH, Park HT, Kim T, Kim SH, Hur JY, Chan RWS, Chan YY, Ng EHY, Yeung WSB, Santulli P, Borghese B, Chopin N, Marcellin L, de Ziegler D, Chapron C, Elnashar A, Badawy A, Mosbah A, Tzioras S, Polyzos NP, Messini CI, Papanikolaou EG, Valachis A, Patavoukas E, Mauri D, Badawy A, Messinis IE, Acar N, Hirota Y, Tranguch S, Daikoku T, Burnum KE, Xie H, Kodama A, Osuga Y, Ustunel I, Friedman DB, Caprioli RM, Dey SK, Mitra A, Sahu R, Pal M, Bhattachrayya AK, Bhattachrya J, Ferrero S, Remorgida V, Rollandi GA, Biscaldi E, Cho S, Choi YS, Kim HY, Seo SK, Yang HI, Lee KE, Shin JH, Lee BS, Arena E, Morando A, Remorgida V, Ferrero S, Tomazevic T, Ban-Frangez H, Virant-Klun I, Verdenik I, Pozlep B, Vrtacnik-Bokal E, Valenzano Menada M, Biscaldi E, Remorgida V, Morotti M, Venturini PL, Rollandi GA, Ferrero S, Dimitriadis E, Salamonsen LA, Hannan N, O'Connor O, Rombauts L, Stoikos C, Mahmoudi M, Shaikh A, Mousavifar N, Rastin M, Baharara J, Tabasi N, Takemura Y, Fujimoto A, Osuga Y, Tsutsumi R, Ooi N, Yano T, Taketani Y, Karkanaki A, Goudakou M, Kalogiannidis I, Panagiotidis I, Prapas Y, Zhang D, Lv PP, Ding GL, Zhang RJ, Zou LB, Xu GF, Gao HJ, Zhu YM, Sheng JZ, Huang HF, Martinez-Conejero JA, Labarta E, Alama P, Pellicer A, Horcajadas JA, Bosch E. Posters * Endometriosis, Endometrium and Implantation. Hum Reprod 2010. [DOI: 10.1093/humrep/de.25.s1.242] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Piche T, Ducrotté P, Sabate JM, Coffin B, Zerbib F, Dapoigny M, Hua M, Marine-Barjoan E, Dainese R, Hébuterne X. Impact of functional bowel symptoms on quality of life and fatigue in quiescent Crohn disease and irritable bowel syndrome. Neurogastroenterol Motil 2010; 22:626-e174. [PMID: 20403099 DOI: 10.1111/j.1365-2982.2010.01502.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
BACKGROUND Patients with irritable bowel syndrome (IBS) and Crohn disease (CD) have impaired quality of life (Qol) associated with fatigue. Whether IBS-like symptoms have a similar impact on Qol and fatigue in quiescent CD than in IBS is currently unknown. Our aims were (i) to evaluate the prevalence of IBS-like symptoms in quiescent CD and (ii) to compare the impact of IBS-like symptoms on Qol and fatigue in both diseases. METHODS A total of 92 quiescent CD, 40 IBS and 20 healthy subjects similar in age were included prospectively in five French academic centers. IBS symptoms were evaluated through the Rome III criteria. The severity of IBS symptoms, Qol, fatigue, depression and anxiety was measured using questionnaires (Francis Score, Likert scales, Fatigue Impact Scale, short-form Beck and Hospital Anxiety and Depression Scale). KEY RESULTS Irritable bowel syndrome-like symptoms were found in 42/92 (45.6%) patients with quiescent CD. The presence of IBS-like symptoms was associated with significant more profound alterations of Qol, high scores of fatigue, depression, but similar levels of anxiety. Compared to CD patients with IBS-like symptoms, IBS patients had more severe gastrointestinal symptoms and alterations of Qol, but similar scores of fatigue, depression and anxiety. In quiescent CD patients, fatigue was independently associated with the presence of IBS-like symptoms (OR = 1.018, 95% CI: 1.002-1.034, P = 0.02). CONCLUSIONS & INFERENCES The prevalence of IBS-like symptoms is elevated in quiescent CD. The presence of IBS-like symptoms in quiescent CD is probably associated with the range of fatigue/depression disorders. The mechanism underlying the occurrence of IBS-like symptoms in quiescent CD needs to be further explored.
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Affiliation(s)
- T Piche
- Faculté de Médecine, Université de Nice Sophia-Antipolis, CHU de Nice, Pôle Digestif, Nice, France.
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Zhang DB, Hua M, Dumitrică T. Stability of polycrystalline and wurtzite Si nanowires via symmetry-adapted tight-binding objective molecular dynamics. J Chem Phys 2008; 128:084104. [DOI: 10.1063/1.2837826] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Huang SS, Liao QL, Hua M, Wu XM, Bi KS, Yan CY, Chen B, Zhang XY. Survey of heavy metal pollution and assessment of agricultural soil in Yangzhong district, Jiangsu Province, China. Chemosphere 2007; 67:2148-55. [PMID: 17275882 DOI: 10.1016/j.chemosphere.2006.12.043] [Citation(s) in RCA: 208] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Revised: 11/10/2006] [Accepted: 12/11/2006] [Indexed: 05/13/2023]
Abstract
We investigated concentrations of Hg, Cd, Pb, Zn, Cu, As, Ni, and Cr in samples of soil, cereal, and vegetables from Yangzhong district, China. Compared to subsoils, the sampled topsoils are enriched in Hg, Cd, Cu, Pb, Zn, and As. High levels of Cd and Hg are observed in most agricultural soils. Concentrations of Cr and Ni show little spatial variation, and high Cu, Pb, and Zn contents correspond well to areas of urban development. High As contents are primarily recorded at the two ends of the sampled alluvion. The contents of Cd, Hg, and total organic carbon (TOC) increase gradually to maximum values in the upper parts of soil profiles, while Cr and Ni occur in low concentrations within sampled profiles. As, Pb, Cu, and Zn show patterns of slight enrichment within the surface layer. Compared to data obtained in 1990, Cd and Hg show increased concentrations in 2005; this is attributed to the long-term use of agrochemicals. Cr and Ni contents remained steady over this interval because they are derived from the weathering of parent material and subsequent pedogenesis. The measured As, Cu, Pb, and Zn contents show slight increases over time due to atmospheric deposition of material sourced from urban anthropogenic activity. Low concentrations of heavy metals are recorded in vegetables and cereals because the subalkaline environment of the soil limits their mobility. Although the heavy metal concentrations measured in this study do not pose a serious health risk, they do affect the quality of agricultural products.
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Affiliation(s)
- S S Huang
- Geological Survey of Jiangsu Province, Nanjing 210018, China.
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Ma H, Niu Y, Wang Z, Li Z, Hua M, Xie Z. Association of the spectral features of heart period signal with SNP of NOS in the Chinese Han nationality population. Conf Proc IEEE Eng Med Biol Soc 2007; 2005:2463-6. [PMID: 17282736 DOI: 10.1109/iembs.2005.1616967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
To explore association of the spectral features of heart period signal with SNPs at 5 sites of NOS gene in the subjects (male89, female77, aged 62.40+/-2.5 yrs) by allele specific primer PCR technique. It was found that the TT allelic genotype of NOS2 C-1173T associated with the highest RPH and TT allelic genotype of NOS3 G894T associated with the highest APH in HPS spectral parameters. This suggests the SNPs of NOS2 C-1173T and NOS3 G894T may be the deep layer factors to result in the variability of HPS spectral parameters.
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Affiliation(s)
- H Ma
- Dept. of Geriatric, Chongqing Univ. of Med. Sci
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Bedford K, Wen L, Hua M, Kehoe P, Rissel C. Smoke near me and I smoke too': evaluation of a smoke-free homes program in central Sydney, NSW. Health Promot J Austr 2003. [DOI: 10.1071/he03108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Parker WB, Shaddix SC, Rose LM, Pham PT, Hua M, Vince R. Metabolism of O6-propyl and N6-propyl-carbovir in CEM cells. Nucleosides Nucleotides Nucleic Acids 2000; 19:795-804. [PMID: 10960036 DOI: 10.1080/15257770008035025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The metabolism of O6-propyl-carbovir and N6-propyl-carbovir, two selective inhibitors of HIV replication, has been evaluated in CEM cells. Both compounds were phosphorylated in intact cells to carbovir-5'-triphosphate. The metabolism of these two agents was inhibited by deoxycoformycin and mycophenolic acid, but not erythro-9-(2-hydroxy-3-nonyl)adenine. No evidence of the 5'-triphosphate of either compound was detected in CEM cells.
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Affiliation(s)
- W B Parker
- Southern Research Institute, Birmingham, AL 35205, USA
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31
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Abstract
The nucleotide substrate specificity of human glycinamide ribonucleotide transformylase, a chemotherapeutic target, has been examined. The enzyme accepts the sarcosyl analog of glycinamide ribonucleotide, carbocyclic glycinamide ribonucleotide, and two phosphonate derivatives of carbocyclic glycinamide ribonucleotide with V/K values, relative to that obtained for beta-glycinamide ribonucleotide, of 1, 27, 1.4, and 2.9%, respectively. Several other analogs of carbocyclic glycinamide ribonucleotide, namely a truncated phosphonate and 2',3'-dideoxy- and 2',3'-dideoxy-2',3'-didehydro-carbocyclic glycinamide ribonucleotide, were inhibitors of the enzyme, competitive against glycinamide ribonucleotide, with Ki values approximately 100 times higher than the Km for -glycinamide ribonucleotide. Although the results of the present study parallel those obtained previously with the avian enzyme (V. D. Antle, D. Liu, B. R. McKellar, C. A. Caperelli, M. Hua, and R. Vince (1996) J. Biol. Chem. 271, 6045-6049), quantitative differences between the two enzyme species have been uncovered.
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Affiliation(s)
- V D Antle
- Division of Pharmaceutical Sciences, College of Pharmacy, University of Cincinnati Medical Center, Ohio 45267-0004, USA
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King L, Thomas M, Gatenby K, Georgiou A, Hua M. "First aid for scalds" campaign: reaching Sydney's Chinese, Vietnamese, and Arabic speaking communities. Inj Prev 1999; 5:104-8. [PMID: 10385828 PMCID: PMC1730502 DOI: 10.1136/ip.5.2.104] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVES As a serious yet preventable problem, scald injuries in children have been a priority for prevention in Australia and other developed countries. Not only can the occurrence of scalds be prevented, but immediate first aid treatment offers an effective method for secondary prevention, reducing the severity of scalds. Despite the success of scald prevention initiatives, local evidence suggested that first aid knowledge was lacking in some minority ethnic groups. To redress this gap, the "First Aid for Scalds" campaign for those from a non-English speaking background was specifically targeted to three ethnic groups (Vietnamese, Chinese, and Arabic), with the aim of increasing the proportions of parents and caregivers who had correct knowledge of first aid treatment for scalds. The primary strategy was a media campaign, including advertisements on ethnic radio and in ethnic newspapers. METHODS The evaluation design included formative research and impact evaluation. The impact evaluation study involved random population based telephone surveys with each of the three language groups, before and after the campaign, to assess the reach and effectiveness of the campaign. RESULTS After the campaign, there were significant increases in the proportion of people who knew the correct first aid treatment for scalds. There were substantial variations in campaign recall and knowledge between each of the three language groups. The largest improvement was found in the Vietnamese group. CONCLUSION The association between campaign recall and increase in correct knowledge, and the absence of any similar interventions during the campaign period, give credence to the conclusion that the changes observed were a result of the campaign. The results demonstrate the value of community based injury prevention campaigns specifically targeting linguistically diverse communities.
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Affiliation(s)
- L King
- School of Medical Education, University of New South Wales
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Lesjak M, Hua M, Ward J. Cervical screening among immigrant Vietnamese women seen in general practice: current rates, predictors and potential recruitment strategies. Aust N Z J Public Health 1999; 23:168-73. [PMID: 10330732 DOI: 10.1111/j.1467-842x.1999.tb01229.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
OBJECTIVE To ascertain cervical screening rates among Vietnamese women attending Vietnamese-speaking general practitioners (GPs) in Sydney, their recall of opportunistic recruitment by these GPs and their preferences for strategies to encourage screening. METHOD Women born in Vietnam aged 18-69 years were recruited through the waiting room of their GP and completed questionnaires in either Vietnamese or Chinese before and after their consultation. RESULTS Of 355 women seen during the survey period, 170 were ineligible. Of those eligible, 118 women (64% response rate) completed waiting room questionnaires. Of 86 women 'at risk', 56 (65%) reported having a cervical smear within two years or due on that day; 26 (86%) of those 30 women overdue for screening reported visiting a GP at least twice in the past six months. After adjustment for age and education, women who were more acculturated or had resided in Australia for the most years remained significantly more likely to be screened (p = 0.027 and p = 0.037 respectively). In the follow-up questionnaire, returned by 49 women (52%) who agreed to receive it, recall of opportunistic advice from the GP was low. Female GPs, free screening and more information in Vietnamese were the three most popular recruitment strategies. CONCLUSION Study confirms low participation rates in cervical screening by Vietnamese women using self-report. Recent immigrants and the least acculturated are least likely to be screened. IMPLICATIONS A community-based strategy involving Vietnamese-speaking GPs shows promise, inviting behavioural evaluation.
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Affiliation(s)
- M Lesjak
- Needs Assessment & Health Outcomes Unit, Central Sydney Area Health Service, New South Wales
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Wei W, Zuoliang Q, Xiaoxi L, Jiasheng D, Chuan Y, Hussain K, Hongtai H, Gontur S, Li Z, Hua M, Tisheng C. Free split and segmental latissimus dorsi muscle transfer in one stage for facial reanimation. Plast Reconstr Surg 1999; 103:473-80; discussion 481-2. [PMID: 9950533 DOI: 10.1097/00006534-199902000-00016] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The authors report the experience in facial reanimation using free innervated split and segmental latissimus dorsi muscle flap one-stage transfer in 86 patients with longstanding facial palsy. The segmental latissimus dorsi was taken from the distal part of the muscle so that the muscle flap had an ultra-long neurovascular pedicle of 13 to 17.5 cm in length. The muscle flap was made thinner by splitting the segmental muscle. The split segmental muscle flap was transferred to the paralyzed side of the face with its ultra-long neurovascular pedicle passing through a tunnel in the upper lip to the normal side of the face. The neurovascular pedicle of the muscle flap was anastomosed with the facial nerve, artery, and veins, respectively, on the normal side of the face. The operation was designed without the cross-facial nerve graft stage. From 1986 to October of 1997, 86 patients with long-standing facial paralysis were treated in our department. The duration of facial palsy in this series ranged from 1.5 to 51 years. A satisfactory result was obtained in 80 cases, evaluated at 8 months to 2 years postoperatively. The expression movement of the soft tissues of the face can be seen not only over transferred muscle but also on the paralyzed muscle covered by the splitting muscle flap. It is supposed that this is the result of muscle-muscle neurolization. Study of 66 specimens of latissimus dorsi muscle in the cadavers is discussed.
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Affiliation(s)
- W Wei
- Department of Plastic and Reconstructive Surgery at the Ninth People's Hospital at Shanghai Second Medical University, China
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Rajavashisth T, Qiao JH, Tripathi S, Tripathi J, Mishra N, Hua M, Wang XP, Loussararian A, Clinton S, Libby P, Lusis A. Heterozygous osteopetrotic (op) mutation reduces atherosclerosis in LDL receptor- deficient mice. J Clin Invest 1998; 101:2702-10. [PMID: 9637704 PMCID: PMC508861 DOI: 10.1172/jci119891] [Citation(s) in RCA: 191] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Previous studies of osteopetrotic (op) mice lacking macrophage colony-stimulating factor (M-CSF) have revealed an inhibition of atherosclerosis development in the apolipoprotein E (apo E)-deficient model and in a diet-induced model. Using LDL receptor-deficient mice, we now show that atheroma development depends on M-CSF concentration, as not only did homozygous osteopetrotic (op/op) mice have dramatically reduced lesions (approximately 0.3% of control lesion size) but heterozygous (op/+) mice had lesions < 1% of controls. Mice heterozygous for the op mutation (op/+) had plasma levels of M-CSF about half those in controls (+/+). The finding that an approximately 2-fold reduction in M-CSF expression reduced lesion size approximately 100-fold suggests the requirement for a threshold level of M-CSF. The effect of M-CSF on atherosclerosis did not appear to be mediated either by changes in plasma lipoprotein levels or alterations in the number of circulating monocytes, since both op/op and op/+ mice exhibited higher levels of atherogenic lipoprotein particles and (op/+) mice showed a near normal number of circulating monocytes. LDL receptor-null littermates of genotypes from op/op, op/+, to +/+ showed monocyte differentials of approximately 4.5, 8, and 10%, respectively. Taken together, these results suggest that the effects of M-CSF on atherogenesis may not be mediated by expression of M-CSF systemically or by modulation of the number of circulating monocytes. These studies support the conclusion that M-CSF participates critically in fatty streak formation and progression to a complex fibrous lesion.
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Affiliation(s)
- T Rajavashisth
- Atherosclerosis Research Center, Division of Cardiology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California 90048, USA.
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Styles LA, Lubin B, Vichinsky E, Lawrence S, Hua M, Test S, Kuypers F. Decrease of very late activation antigen-4 and CD36 on reticulocytes in sickle cell patients treated with hydroxyurea. Blood 1997; 89:2554-9. [PMID: 9116302] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Sickle cell disease (SCD) is characterized by repeated vaso-occlusive events, which result in substantial morbidity. Abnormal adhesion of sickle red blood cells (RBC) to the vascular endothelium is postulated to play a role in the pathogenesis of vaso-occlusion. Two adhesion receptors, very late activation antigen-4 (VLA-4) and CD36, are found in unusually high numbers on sickle cell reticulocytes and do mediate adhesion of sickle RBC to endothelium. Hydroxyurea (HU) therapy results in fewer vaso-occlusive episodes, and we postulated that HU-related modulation of VLA-4 and CD36 receptors may contribute to its clinical benefit. Using flow cytometry, eight patients were followed from the onset of HU treatment through a mean treatment length of 200 +/- 49 days. Mean corpuscular volume and percent fetal hemoglobin (Hb F) increased from 87% +/- 6% to 98% +/- 9% and 6.6% +/- 3.9% to 12.7% +/- 5.6%, respectively. The percentage of reticulocytes expressing VLA-4 decreased from 29.0% +/- 5.9% to 14.9% +/- 2.3% (P = .0003). Two thirds of the total decrease in VLA-4 expression occurred after 10 weeks of HU and plateaued by 20 weeks. Changes in VLA-4 expression occurred before substantial increases in Hb F. The percentage of reticulocytes expressing CD36 decreased from 55.3% +/- 6.4% to 42.6% (P = .0046). Changes in adhesion receptor expression were not caused by a decrease in reticulocytosis with HU therapy. This report is the first to associate a decrease in adhesion receptor expression with a therapy known to reduce the clinical severity of SCD.
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Affiliation(s)
- L A Styles
- Department of Hematology/Oncology, Children's Hospital, Oakland, CA 94609, USA
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Abstract
Several analogs of glycinamide ribonucleotide and phosphoribosylamine have been prepared and evaluated as substrates for glycinamide ribonucleotide synthetase purified from chicken liver. Glycinamide ribonucleotide analogs include side chain modifications wherein the glycine side chain (R = CH2NH2) has been replaced by R = CH2NHCH3 and R = CH2CH2NH2, ribose ring replacement by chiral cyclopentane and cyclopentene derivatives, and phosphate replacement by phosphonates. All of these, with the exception of the O-phosphonate, served as substrates for the reverse enzymatic reaction, with Vmax values comparable to that obtained with glycinamide ribonucleotide, although the Km values ranged from 21 to 118 times the Km for glycinamide ribonucleotide. Analogs of phosphoribosylamine examined as substrates for the forward reaction consist of chiral derivatives of cyclopentane and cyclopentene and a chiral carbocyclic phosphonate. These also served as substrates, with Km values ranging from 5 to 23 times the Km for phosphoribosylamine and with diminished Vmax values. These studies have begun to define the structural features of the nucleotide substrate necessary to support enzymatic activity. Sarcosine (N-methylglycine) and beta-alanine were also accepted as substrates, albeit with reduced affinity compared with glycine.
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Affiliation(s)
- V D Antle
- Division of Pharmaceutical Sciences, College of Pharmacy, University of Cincinnati Medical Center, Cincinnati, Ohio 45267-0004, USA
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Antle VD, Liu D, McKellars BR, Caperelli CA, Hua M, Vince R. Substrate specificity of glycinamide ribonucleotide transformylase from chicken liver. J Biol Chem 1996; 271:6045-9. [PMID: 8626389 DOI: 10.1074/jbc.271.11.6045] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Several glycinamide ribonucleotide analogs have been prepared and evaluated as substrates and/or inhibitors of glycinamide ribonucleotide transformylase from chicken liver. The side chain modified analogs, in which the glycine side chain, R = CH2NH2, has been replaced by R = CH2NHCH3 and R = CH2CH2NH2, are substrates, with V/K (relative intensity) of 2.4% and 16.3%, respectively. Several carbocyclic analogs of glycinamide ribonucleotide, including the phosphonate derivative of carbocyclic glycinamide ribonucleotide, did not serve as substrates, but were inhibitors of the enzyme, competitive against glycinamide ribonucleotide, with Ki values ranging from 7.4 to 23.6 times the Km for glycinamide ribonucleotide. However, the O-phosphonate analog of carbocyclic glycinamide ribonucleotide did support enzymatic activity, with V/K (relative intensity) of 0.8%. In addition, glycinamide ribonucleoside was neither a substrate for, nor an inhibitor of, glycinamide ribonucleotide transformylase. Furthermore, alpha-glycinamide ribonucleotide had no effect on enzyme activity. These studies have begun to define the structural features of the nucleotide substrate required to support enzymatic activity.
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Affiliation(s)
- V D Antle
- Division of Pharmaceutical Sciences, College of Pharmacy, University of Cincinnati Medical Center, Ohio 45267-0004, USA
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Kuypers FA, Lewis RA, Hua M, Schott MA, Discher D, Ernst JD, Lubin BH. Detection of altered membrane phospholipid asymmetry in subpopulations of human red blood cells using fluorescently labeled annexin V. Blood 1996; 87:1179-87. [PMID: 8562945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The phospholipids of the human red cell are distributed asymmetrically in the bilayer of the red cell membrane. In certain pathologic states, such as sickle cell anemia, phospholipid asymmetry is altered. Although several methods can be used to measure phospholipid organization, small organizational changes have been very difficult to assess. Moreover, these methods fail to identify subpopulations of cells that have lost their normal phospholipid asymmetry. Using fluorescently labeled annexin V in flow cytometry and fluorescent microscopy, we were able to identify and quantify red cells that had lost their phospholipid asymmetry in populations as small as 1 million cells. Moreover, loss of phospholipid organization in subpopulations as small as 0.1% of the total population could be identified, and individual cells could be studied by fluorescent microscopy. An excellent correlation was found between fluorescence-activated cell sorter (FACS) analysis results using annexin V to detect red cells with phosphatidylserine (PS) on their surface and a PS-requiring prothrombinase assay using similar red cells. Cells that bound fluorescein isothiocyanate (FITC)-labeled annexin V could be isolated from the population using magnetic beads covered with an anti-FITC antibody. Evaluation of blood samples from patients with sickle cell anemia under oxygenated conditions demonstrated the presence of subpopulations of cells that had lost phospholipid asymmetry. While only a few red cells were labeled in normal control samples (0.21% +/- 0.12%, n = 8), significantly increased (P < .001) annexin V labeling was observed in samples from patients with sickle cell anemia (2.18% +/- 1.21%, n = 13). We conclude that loss of phospholipid asymmetry may occur in small subpopulations of red cells and that fluorescently labeled annexin V can be used to quantify and isolate these cells.
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Affiliation(s)
- F A Kuypers
- Children's Hospital Oakland Research Institute, CA 94609, USA
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Larson DL, Hua M, Takemori AE, Portoghese PS. Possible contribution of a glutathione conjugate to the long-duration action of beta-funaltrexamine. J Med Chem 1993; 36:3669-73. [PMID: 8246236 DOI: 10.1021/jm00075a023] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The fumaramate derivative of naltrexone, beta-funaltrexamine (beta-FNA), is a highly selective long-lasting mu opioid receptor antagonist that is active both in vitro and in vivo, presumably as a result of covalent binding to a mu receptor-based sulfhydryl group. Glutathione, which occurs in significant levels in brain and liver, was found to undergo a Michael-type reaction with beta-FNA in the test tube to give a stable conjugate 3 which occurred as an isomeric mixture. When tested in the GPI and MVD smooth muscle preparations, 3 was found to possess one-tenth the agonist activity of beta-FNA is both tissues, but showed no irreversible antagonist activity. The same result was found for the cysteine conjugate 4, except for some irreversible antagonism in the MVD. Both conjugates antagonize the antinociceptive effect of morphine in the mouse radiant heat tail-flick assay on icv administration. This antagonism persisted and actually increased over 24 h and generally paralleled the duration profile of beta-FNA. On sc administration, beta-FNA and 3 showed similar duration of antagonistic effect, while 4 exhibited only marginal activity at the early time interval. When the compounds are compared by the dose to produce equivalent antagonism, beta-FNA and 3 appeared equally effective and accessible by either route, whereas 4 showed a large difference between the two routes. It is possible that the ultra-long antagonism of the conjugates may result from their enzymatic conversion to beta-FNA in the central nervous system in view of the fact that conjugate 5, which cannot be converted to beta-FNA, did not produce antagonism of long duration in vivo. Alternatively, the protracted antagonism could arise from sequestration of 3 and 4 in tissue compartments that interface with mu opioid receptors.
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Affiliation(s)
- D L Larson
- Department of Medicinal Chemistry College of Pharmacy, Medical School, University of Minnesota, Minneapolis 55455
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Friedmann EI, Hua M, Ocampo-Friedmann R. Terraforming Mars: dissolution of carbonate rocks by cyanobacteria. J Br Interplanet Soc 1993; 46:291-2. [PMID: 11540501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
One of the most difficult tasks in terraforming Mars is the release into the atmosphere of CO2 bound by the surface of Mars. Even if a sufficiently dense CO2 atmosphere can be created by appropriate technology, the maintenance of CO2 concentration remains a problem. As Mars lacks plate tectonics as well as active volcanism, an Earth-like carbon cycle cannot be reproduced there. We suggest that Matteia sp., a lime-boring cyanobacterium isolated from Negev desert rocks, be used to dissolve carbonate rocks both for initial release of CO2 and in design of a Martian carbon cycle.
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Affiliation(s)
- E I Friedmann
- Department of Biological Science, Florida State University, Tallahassee 32306-2043, USA
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43
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Hua M. A demographic dynamic model of age, marriage, parity and parity interval. Chin J Popul Sci 1992; 4:339-50. [PMID: 12318213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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44
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Wang J, Hua M. [Myosin polymorphism and exercise adaptation]. Sheng Li Ke Xue Jin Zhan 1991; 22:51-4. [PMID: 1829544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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45
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Yu XM, Hua M, Mense S. The effects of intracerebroventricular injection of naloxone, phentolamine and methysergide on the transmission of nociceptive signals in rat dorsal horn neurons with convergent cutaneous-deep input. Neuroscience 1991; 44:715-23. [PMID: 1661386 DOI: 10.1016/0306-4522(91)90090-b] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In anaesthetized rats, recordings were made from nociceptive dorsal horn neurons with convergent input from the skin and deep somatic tissues. The results of a previous study have shown that in these neurons the input from deep nociceptors is subjected to a much stronger tonic descending inhibition than is the input from cutaneous nociceptors. The aim of the present study was to find out whether at supraspinal levels opioidergic, adrenergic, or serotoninergic transmitters are involved in this quite specific inhibition of deep nociception. Injections of naloxone, phentolamine, and methysergide into the third ventricle showed that only naloxone is capable of abolishing the tonic inhibition of the deep nociceptive input to spinal neurons. The input from cutaneous nociceptors to the same cells was largely unaffected by naloxone. Thus the effects of intracerebroventricular injection of naloxone resembled those obtained with a spinal cold block in a previous study; with the exception that the increase in background activity--which is prominent during cold block--was missing after the injection of naloxone. The present results demonstrate that the tonic descending inhibition of the deep nociception operates with opioidergic synapses at the supraspinal level. In contrast, supraspinal adrenergic and serotoninergic mechanisms do not appear to contribute to the tonic inhibition. The data confirm and extend previous results which suggested that a particular portion of the descending antinociceptive system may act mainly on the input from deep nociceptors. Pharmacologically, this particular portion seems to be opioidergic in nature.
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Affiliation(s)
- X M Yu
- Institut für Anatomie und Zellbiologie, Universität Heidelberg, F.R.G
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Abstract
(+-)-cis-[4-[(2,5-Diamino-6-chloropyrimidinyl)amino]-2- cyclopentenyl]carbinol (5a) was synthesized from 2-amino-4,6-dichloropyrimidine and cis-4-(hydroxymethyl)cyclopentenylamine (2a) by subsequent preparation of the 5-[(4-chlorophenyl)azo] derivative of the resulting pyrimidine (3a) and reduction of the azo moiety with zinc and acetic acid. The carbocyclic analogue of 2',3'-didehydro-2',3'-dideoxy 2-amino-6-chloropurine (6a) and the corresponding 8-azapurine (9a) were prepared from 5a. The carbocyclic 2',3'-didehydro-2',3'-dideoxy analogues of guanine (7a) and 2,6-diaminopurine (8a), and 8-azaguanine (10a) and 8-aza-2,6-diaminopurine (11a) were prepared from 6a and 9a, respectively. The corresponding 2',3'-saturated series of 2-amino-6-substituted-purine carbocyclic nucleosides was prepared following the same scheme starting with cis-4-(hydroxymethyl)cyclopentylamine (2b). Carbocyclic 2',3'-didehydro-2',3'-dideoxyguanosine (carbovir, 7a) emerged as a potent and selective anti-HIV agent. Its hydrolytic stability and its ability to inhibit the infectivity and replication of HIV in T-cells at concentrations of approximately 200-400-fold below toxic concentrations make carbovir an excellent candidate for development as a potential antiretroviral agent.
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Affiliation(s)
- R Vince
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis 55455
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47
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Remmel RP, Yeom YH, Hua M, Vince R, Zimmerman CL. Liquid chromatographic assay of carbovir, a carbocyclic nucleoside active against human immunodeficiency virus. J Chromatogr 1989; 489:323-31. [PMID: 2753956 DOI: 10.1016/s0378-4347(00)82910-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Carbovir is a novel carbocyclic guanosine derivative that has potent in vitro activity against human immunodeficiency virus, the causative agent of acquired immunodeficiency syndrome (AIDS). Two methods of sample preparation were developed for the analysis of carbovir in rat blood. Solid-phase extraction on C18 extraction columns proved to be the most effective. Whole rat blood (200 microliters) was diluted with 0.8 ml of distilled water containing the internal standard. After two freeze-thaw cycles to lyse the red blood cells and subsequent centrifugation at 13,000 g, the supernatant was loaded on the C18 extraction columns. Carbovir and the internal standard were eluted with methanol-water (60:40). The extract was evaporated and reconstituted in mobile phase and the samples were injected onto a high-capacity reversed-phase column. The compounds were detected at 252 nm. Other nucleosides that could be used in the treatment of AIDS such as zidovudine and acyclovir did not interfere. Standard curves were linear over the concentration range 0.156-28.0 micrograms/ml (r2 greater than 0.99). The within-day coefficient of variation was less than 7.6% at all concentrations (n = 4). The between-day coefficient of variation ranged from 16.7 to 2.0% (n = 14). The limit of sensitivity was 0.05 micrograms/ml with a 200-microliters blood sample and the average extraction recovery was 74%. Carbovir was stable in rat blood for at least 4 h at 37 degrees C. The assay was used to determine the blood levels of carbovir in a rat after a 20 mg/kg intravenous dose.
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Affiliation(s)
- R P Remmel
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis 55455
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48
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Yeom YH, Remmel RP, Huang SH, Hua M, Vince R, Zimmerman CL. Pharmacokinetics and bioavailability of carbovir, a carbocyclic nucleoside active against human immunodeficiency virus, in rats. Antimicrob Agents Chemother 1989; 33:171-5. [PMID: 2719460 PMCID: PMC171451 DOI: 10.1128/aac.33.2.171] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Carbovir is a novel carbocyclic nucleoside which has been shown to have potent in vitro activity against human immunodeficiency virus, the causative agent of acquired immunodeficiency syndrome. Sprague-Dawley male rats were used to investigate the pharmacokinetics and bioavailability of carbovir. Six rats received carbovir (20 mg/kg of body weight) through the jugular vein, and blood samples were collected through the femoral vein 2, 5, 10, 15, 20, 30, 45, 60, 75, 90, 120, 150, 180, and 240 min after the dose. Four of these rats also received a 60-mg/kg oral dose of carbovir, and a similar blood sampling schedule was followed. Whole-blood samples were prepared by solid-phase extraction, and the carbovir concentration in the samples was analyzed by reversed-phase high-pressure liquid chromatography. The profile of carbovir concentration in blood versus time after the intravenous dose was biexponential, with a very rapid distribution phase. Terminal elimination half-life was 21.4 +/- 4.37 min, and total body clearance was 55.2 +/- 13.8 ml/min per kg, which was within the range of the hepatic blood flow. The volume of distribution at steady state was 1,123 +/- 250 ml/kg. The blood/plasma ratio and the plasma protein binding of carbovir in rat blood were determined in vitro by ultrafiltration. The plasma protein binding of carbovir was only 20% and was not concentration dependent. However, the blood/plasma ratio decreased significantly as concentration increased, indicating saturable binding sites in erythrocytes. After the oral dose, the terminal half-life was 81.0 +/- 67.6 min, indicating that oral carbovir followed "flip-flop" kinetics, with absorption being much slower than elimination of the drug from the body. Oral bioavailability was 0.101 +/- 0.035. Double peaks were present in the concentration-time profile for each rat receiving the oral dose, indicating either a delay in stomach emptying of the drug or slow dissolution of precipitated carbovir in the stomach and upper small intestine.
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Affiliation(s)
- Y H Yeom
- Department of Pharmaceutics, College of Pharmacy, University of Minnesota, Minneapolis 55455
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49
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Vince R, Hua M, Brownell J, Daluge S, Lee FC, Shannon WM, Lavelle GC, Qualls J, Weislow OS, Kiser R. Potent and selective activity of a new carbocyclic nucleoside analog (carbovir: NSC 614846) against human immunodeficiency virus in vitro. Biochem Biophys Res Commun 1988; 156:1046-53. [PMID: 2847711 DOI: 10.1016/s0006-291x(88)80950-1] [Citation(s) in RCA: 204] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Carbocyclic 2',3'-didehydro-2',3'-dideoxyguanosine (Carbovir: NSC 614846), a novel nucleoside analog, emerged as a potent and selective anti-HIV agent from a large screening program conducted by the National Cancer Institute and its contractors. Its hydrolytic stability and its ability to inhibit the infectivity and replication of HIV in T-cells at concentrations of approximately 200- to 400-fold below toxic concentrations make carbovir a top-priority candidate for development as a potential antiretroviral agent in the treatment of AIDS patients.
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Affiliation(s)
- R Vince
- Department of Medicinal Chemistry, College of Pharmacy, University of Minnesota, Minneapolis 55455
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50
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Friedmann EI, Hua M, Ocampo-Friedmann R. Cryptoendolithic lichen and cyanobacterial communities of the Ross Desert, Antarctica. Polarforschung 1988; 58:251-259. [PMID: 11538357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Cryptoendolithic microbial communities in the Ross Desert (McMurdo Dry Valleys) are characterized on the basis of photosynthetic microorganisms and fungi. Two eukaryotic communities (the lichen-dominated and Hemichloris communities) and three cyanobacterial communities (the red Gloeocapsa, Hormathonema-Gloeocapsa, and Chroococcidiopsis communities) are described. Eleven coccoid, one pleurocapsoid, and five filamentous cyanobacteria occurring in these communities are characterized and illustrated. The moisture grade of the rock substrate seems to affect pH, formation of primary iron stain, and the distribution of microbial communities.
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Affiliation(s)
- E I Friedmann
- Department of Biological Science, Florida State University, Tallahassee 32306-2043, USA
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