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Han SY, Telford EJ, Kundu AK, Bintrim SJ, Turkel S, Wiscons RA, Zangiabadi A, Choi ES, Li TD, Steigerwald ML, Berkelbach TC, Pasupathy AN, Dean CR, Nuckolls C, Roy X. Interplay between Local Moment and Itinerant Magnetism in the Layered Metallic Antiferromagnet TaFe 1.14Te 3. Nano Lett 2023; 23:10449-10457. [PMID: 37934894 DOI: 10.1021/acs.nanolett.3c03112] [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] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
Two-dimensional antiferromagnets have garnered considerable interest for the next generation of functional spintronics. However, many bulk materials from which two-dimensional antiferromagnets are isolated are limited by their air sensitivity, low ordering temperatures, and insulating transport properties. TaFe1+yTe3 aims to address these challenges with increased air stability, metallic transport, and robust antiferromagnetism. Here, we synthesize TaFe1+yTe3 (y = 0.14), identify its structural, magnetic, and electronic properties, and elucidate the relationships between them. Axial-dependent high-field magnetization measurements on TaFe1.14Te3 reveal saturation magnetic fields ranging between 27 and 30 T with saturation magnetic moments of 2.05-2.12 μB. Magnetotransport measurements confirm that TaFe1.14Te3 is metallic with strong coupling between magnetic order and electronic transport. Angle-resolved photoemission spectroscopy measurements across the magnetic transition uncover a complex interplay between itinerant electrons and local magnetic moments that drives the magnetic transition. We demonstrate the ability to isolate few-layer sheets of TaFe1.14Te3, establishing TaFe1.14Te3 as a potential platform for two-dimensional spintronics.
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Affiliation(s)
- Sae Young Han
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Evan J Telford
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
- Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027, United States
| | - Asish K Kundu
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, PO Box 5000, Upton, New York 11973, United States
| | - Sylvia J Bintrim
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Simon Turkel
- Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027, United States
| | - Ren A Wiscons
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Amirali Zangiabadi
- Department of Applied Physics and Applied Mathematics, Columbia University, 500 W 120th St, New York, New York 10027, United States
| | - Eun-Sang Choi
- National High Magnetic Field Laboratory, 1800 E Paul Dirac Dr, Tallahassee, Florida 32310, United States
| | - Tai-De Li
- Nanoscience Initiative at Advanced Science Research Center, Graduate Center of the City University of New York, 85 St. Nicholas Terrace, New York, New York 10031, United States
- Department of Physics, The City College of New York, 160 Convent Avenue, New York, New York 10031, United States
| | - Michael L Steigerwald
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Timothy C Berkelbach
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Abhay N Pasupathy
- Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027, United States
- Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, PO Box 5000, Upton, New York 11973, United States
| | - Cory R Dean
- Department of Physics, Columbia University, 538 West 120th Street, New York, New York 10027, United States
| | - Colin Nuckolls
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
| | - Xavier Roy
- Department of Chemistry, Columbia University, 3000 Broadway, New York, New York 10027, United States
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2
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Yin Y, Zhou Y, Fu S, Zuo X, Lin YC, Wang L, Xue Y, Zhang Y, Tsai EHR, Hwang S, Kissenger K, Li M, Cotlet M, Li TD, Yager KG, Nam CY, Rafailovich MH. Enhancing Crystallization in Hybrid Perovskite Solar Cells Using Thermally Conductive 2D Boron Nitride Nanosheet Additive. Small 2023; 19:e2207092. [PMID: 36631283 DOI: 10.1002/smll.202207092] [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] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 12/29/2022] [Indexed: 06/17/2023]
Abstract
Controlling crystallization and grain growth is crucial for realizing highly efficient hybrid perovskite solar cells (PSCs). In this work, enhanced PSC photovoltaic performance and stability by accelerating perovskite crystallization and grain growth via 2D hexagonal boron nitride (hBN) nanosheet additives incorporated into the active perovskite layer are demonstrated. In situ X-ray scattering and infrared thermal imaging during the perovskite annealing process revealed the highly thermally conductive hBN nanosheets promoted the phase conversion and grain growth in the perovskite layer by facilitating a more rapid and spatially uniform temperature rise within the perovskite film. Complementary structural, physicochemical, and electrical characterizations further showed that the hBN nanosheets formed a physical barrier at the perovskite grain boundaries and the interfaces with charge transport layers, passivating defects, and retarding ion migration. As a result, the power conversion efficiency of the PSC is improved from 17.4% to 19.8%, along with enhanced device stability, retaining ≈90% of the initial efficiency even after 500 h ambient air storage. The results not only highlight 2D hBN as an effective additive for PSCs but also suggest enhanced thermal transport as one of the pathways for improved PSC performance by 2D material additives in general.
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Affiliation(s)
- Yifan Yin
- Department of Material Science and Chemical Engineering, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Yuchen Zhou
- Department of Material Science and Chemical Engineering, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Shi Fu
- Department of Material Science and Chemical Engineering, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Xianghao Zuo
- Department of Material Science and Chemical Engineering, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Yu-Chung Lin
- Department of Material Science and Chemical Engineering, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Likun Wang
- Department of Material Science and Chemical Engineering, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Yuan Xue
- Department of Material Science and Chemical Engineering, Stony Brook University, Stony Brook, NY, 11794, USA
| | - Yugang Zhang
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Esther H R Tsai
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Sooyeon Hwang
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Kim Kissenger
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Mingxing Li
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Mircea Cotlet
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Tai-De Li
- Advanced Science Research Center, Graduate Center of City University of New York, New York, NY, 10031, USA
| | - Kevin G Yager
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Chang-Yong Nam
- Department of Material Science and Chemical Engineering, Stony Brook University, Stony Brook, NY, 11794, USA
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973, USA
| | - Miriam H Rafailovich
- Department of Material Science and Chemical Engineering, Stony Brook University, Stony Brook, NY, 11794, USA
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3
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Jain A, Kassem S, Fisher RS, Wang B, Li TD, Wang T, He Y, Elbaum-Garfinkle S, Ulijn RV. Connected Peptide Modules Enable Controlled Co-Existence of Self-Assembled Fibers Inside Liquid Condensates. J Am Chem Soc 2022; 144:15002-15007. [PMID: 35946870 DOI: 10.1021/jacs.2c05897] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Supramolecular self-assembly of fibrous components and liquid-liquid phase separation are at the extremes of the order-to-disorder spectrum. They collectively play key roles in cellular organization. It is still a major challenge to design systems where both highly ordered nanostructures and liquid-liquid phase-separated domains can coexist. We present a three-component assembly approach that generates fibrous domains that exclusively form inside globally disordered, liquid condensates. This is achieved by creating amphiphilic peptides that combine the features of fibrillar assembly (the amyloid domain LVFFA) and complex coacervation (oligo-arginine and adenosine triphosphate (ATP)) in one peptide, namely, LVFFAR9. When this hybrid peptide is mixed in different ratios with R9 and ATP, we find that conditions can be created where fibrous assembly is exclusively observed inside liquid coacervates. Through fluorescence and atomic force microscopy characterization, we investigate the dynamic evolution of ordered and disordered features over time. It was observed that the fibers nucleate and mature inside the droplets and that these fiber-containing liquid droplets can also undergo fusion, showing that the droplets remain liquid-like. Our work thus generates opportunities for the design of ordered structures within the confined environment of biomolecular condensates, which may be useful to create supramolecular materials in defined compartments and as model systems that can enhance understanding of ordering principles in biology.
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Affiliation(s)
- Ankit Jain
- Nanoscience Initiative at Advanced Science Research Center, Graduate Center of the City University of New York, New York, New York 10031, United States
| | - Salma Kassem
- Nanoscience Initiative at Advanced Science Research Center, Graduate Center of the City University of New York, New York, New York 10031, United States
| | - Rachel S Fisher
- Structural Biology Initiative at Advanced Science Research Center, Graduate Center of the City University of New York, New York, New York 10031, United States
| | - Biran Wang
- Molecular Cytology, Memorial Sloan Kettering Cancer Center, New York, New York 10065, United States
| | - Tai-De Li
- Nanoscience Initiative at Advanced Science Research Center, Graduate Center of the City University of New York, New York, New York 10031, United States.,Department of Physics, City College of New York, City University of New York, New York, New York 10031, United States
| | - Tong Wang
- Nanoscience Initiative at Advanced Science Research Center, Graduate Center of the City University of New York, New York, New York 10031, United States
| | - Ye He
- Neuroscience Initiative at Advanced Science Research Center, Graduate Center of the City University of New York, New York, New York 10031, United States.,Division of Science, The City College of New York, New York, New York 10031, United States
| | - Shana Elbaum-Garfinkle
- Structural Biology Initiative at Advanced Science Research Center, Graduate Center of the City University of New York, New York, New York 10031, United States.,Ph.D. Programs in Biochemistry and Chemistry, The Graduate Center of the City University of New York, New York, New York 10016, United States
| | - Rein V Ulijn
- Nanoscience Initiative at Advanced Science Research Center, Graduate Center of the City University of New York, New York, New York 10031, United States.,Ph.D. Programs in Biochemistry and Chemistry, The Graduate Center of the City University of New York, New York, New York 10016, United States.,Department of Chemistry Hunter College, City University of New York, New York, New York 10065, United States
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4
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Li TD, Bieling P, Weichsel J, Mullins RD, Fletcher DA. The molecular mechanism of load adaptation by branched actin networks. eLife 2022; 11:e73145. [PMID: 35748355 PMCID: PMC9328761 DOI: 10.7554/elife.73145] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 06/07/2022] [Indexed: 11/13/2022] Open
Abstract
Branched actin networks are self-assembling molecular motors that move biological membranes and drive many important cellular processes, including phagocytosis, endocytosis, and pseudopod protrusion. When confronted with opposing forces, the growth rate of these networks slows and their density increases, but the stoichiometry of key components does not change. The molecular mechanisms governing this force response are not well understood, so we used single-molecule imaging and AFM cantilever deflection to measure how applied forces affect each step in branched actin network assembly. Although load forces are observed to increase the density of growing filaments, we find that they actually decrease the rate of filament nucleation due to inhibitory interactions between actin filament ends and nucleation promoting factors. The force-induced increase in network density turns out to result from an exponential drop in the rate constant that governs filament capping. The force dependence of filament capping matches that of filament elongation and can be explained by expanding Brownian Ratchet theory to cover both processes. We tested a key prediction of this expanded theory by measuring the force-dependent activity of engineered capping protein variants and found that increasing the size of the capping protein increases its sensitivity to applied forces. In summary, we find that Brownian Ratchets underlie not only the ability of growing actin filaments to generate force but also the ability of branched actin networks to adapt their architecture to changing loads.
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Affiliation(s)
- Tai-De Li
- Department of Bioengineering & Biophysics Program, University of California, BerkeleyBerkeleyUnited States
- Division of Biological Systems & Engineering, Lawrence Berkeley National LaboratoryBerkeleyUnited States
- Advanced Science Research Center, City University of New YorkNew YorkUnited States
| | - Peter Bieling
- Division of Biological Systems & Engineering, Lawrence Berkeley National LaboratoryBerkeleyUnited States
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San FranciscoSan FranciscoUnited States
- Department of Systemic Cell Biology, Max Planck Institute of Molecular PhysiologyDortmundGermany
| | - Julian Weichsel
- Department of Chemistry, University of California, BerkeleyBerkeleyUnited States
| | - R Dyche Mullins
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San FranciscoSan FranciscoUnited States
| | - Daniel A Fletcher
- Department of Bioengineering & Biophysics Program, University of California, BerkeleyBerkeleyUnited States
- Division of Biological Systems & Engineering, Lawrence Berkeley National LaboratoryBerkeleyUnited States
- Chan Zuckerberg BiohubSan FranciscoUnited States
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5
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Giebel BM, Cime S, Rodgers L, Li TD, Zhang S, Wang T. Short-term exposure to soils and sludge induce changes to plastic morphology and 13C stable isotopic composition. Sci Total Environ 2022; 821:153375. [PMID: 35093377 DOI: 10.1016/j.scitotenv.2022.153375] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [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: 10/26/2021] [Revised: 12/16/2021] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
There is concern about the buildup of plastic waste in soil, their degradation into microplastics, and their potential to interfere with the natural processing of soil organic carbon and other nutrient cycling processes. Here we used scanning electron microscopy (SEM) and 13C isotope ratio mass spectrometry to determine if precut consumer plastics comprised of either high density polyethylene (HDPE), a blend of linear low density polyethylene and low density polyethylene (L/LDPE), or polyethylene terephthalate (PETE) would degrade or transform during a short-term, 32 day, exposure to soil or sludge in laboratory microcosms. SEM confirmed morphological changes occurred to all plastics, but the attachment of biofilm and presence of microorganisms mostly favored PETE and HDPE surfaces. These observations support the idea that abiotic and/or biotic processes may degrade plastics in soil; however distinguishable and significant changes in mean stable isotopic values (Δδ13C) of ~0.2-0.7‰ were only observed for exposed PETE and HDPE. This indicates that each plastic's degradation in soil may be dependent on their physical and chemical properties, with L/LDPE being more resistant and less prone to degradation compared to the others, and less dependent on the environmental conditions or properties of the soil or sludge. Our experiments were short-term and while the mechanisms of degradation are not clear, the results provide strong motivation for further studies of plastic fate and processing in soil systems. Direct mechanistic studies using stable isotopic approaches in combination with other characterizations and techniques are clearly warranted and may lead to a significant enhancement in our present understanding of the interactions and dynamics of plastics in the soil environment.
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Affiliation(s)
- Brian M Giebel
- Environmental Sciences Initiative, Advanced Science Research Center, The Graduate Center, City University of New York, New York, NY 10031, USA.
| | - Schidza Cime
- Chemical Engineering Department, The City College of New York, City University of New York, New York, NY 10031, USA
| | - Lauren Rodgers
- Environmental Sciences Initiative, Advanced Science Research Center, The Graduate Center, City University of New York, New York, NY 10031, USA
| | - Tai-De Li
- Nanoscience Initiative, Advanced Science Research Center, The Graduate Center, City University of New York, New York, NY 10031, USA
| | - Sheng Zhang
- Nanoscience Initiative, Advanced Science Research Center, The Graduate Center, City University of New York, New York, NY 10031, USA
| | - Tong Wang
- Nanoscience Initiative, Advanced Science Research Center, The Graduate Center, City University of New York, New York, NY 10031, USA
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6
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Jung Y, Sharifi Golru S, Li TD, Biddinger EJ, Tu RS, Chen X. Tuning water-responsiveness with Bombyx mori silk-silica nanoparticle composites. Soft Matter 2021; 17:7817-7821. [PMID: 34612350 DOI: 10.1039/d1sm00794g] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Bombyx (B.) mori silk's water-responsive actuation correlates to its high β-sheet crystallinity. In this research, we demonstrated that stiff silica nanoparticles can mimic the role of dispersed β-sheet nanocrystals and dramatically increase amorphous silk's water-responsive actuation energy density to ∼700 kJ m-3.
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Affiliation(s)
- Yeojin Jung
- Department of Chemical Engineering, The City College of New York, 160 Convent Avenue, New York, NY 10031, USA.
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7
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Azeem I, El yaagoubi M, Sousa AML, Li TD, Yameen B, Lau KHA. Binding enhancements of antibody functionalized natural and synthetic fibers. RSC Adv 2021; 11:30353-30360. [PMID: 35480255 PMCID: PMC9041155 DOI: 10.1039/d1ra04645d] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 09/02/2021] [Indexed: 12/05/2022] Open
Abstract
Development of low cost biosensing using convenient and environmentally benign materials is important for wide adoption and ultimately improved healthcare and sustainable development. Immobilized antibodies are often incorporated as an essential biorecognition element in point-of-care biosensors but these proteins are costly. We present a strategy of combining convenient and low-cost surface functionalization approaches for increasing the overall binding activity of antibody functionalized natural and synthetic fibers. We demonstrate a simple one-step in situ silica NP growth protocol for increasing the surface area available for functionalization on cotton and polyester fabrics as well as on nanoporous cellulose substrates. Comparing this effect with the widely adopted and low cost plant-based polyphenol coating to enhance antibody immobilization, we find that both approaches can similarly increase overall surface activity, and we illustrate conditions under which the two approaches can produce an additive effect. Furthermore, we introduce co-immobilization of antibodies with a sacrificial “steric helper” protein for further enhancing surface activities. In combination, several hundred percent higher activities compared to physical adsorption can be achieved while maintaining a low amount of antibodies used, thus paving a practical path towards low cost biosensing. Cotton, nanoporous cellulose and polyester fabric surfaces are functionalized with combinations of in situ grown silica NPs, polyphenol coating, and protein co-immobilization to enhance surface area, antibody binding efficiency, and biosensing.![]()
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Affiliation(s)
- Iqra Azeem
- Department of Chemistry and Chemical Engineering, Syed Babar Ali School of Science and Engineering (SBASSE), Lahore University of Management Sciences (LUMS), Lahore 54792, Pakistan
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, UK
| | - Marwa El yaagoubi
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, UK
| | - Ana M. L. Sousa
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, UK
| | - Tai-De Li
- Advanced Science Research Center (ASRC) of Graduate Center, Department of Physics in City University of New York, CUNY, New York, NY 10031, USA
| | - Basit Yameen
- Department of Chemistry and Chemical Engineering, Syed Babar Ali School of Science and Engineering (SBASSE), Lahore University of Management Sciences (LUMS), Lahore 54792, Pakistan
| | - King Hang Aaron Lau
- Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, UK
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8
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Yun JP, Li TD, Liu F, Zhang WQ. [The study on the detection method for mercury in blood with direct mercury analyzer]. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 2020; 38:770-771. [PMID: 33142385 DOI: 10.3760/cma.j.cn121094-20190403-000134] [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] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To establish a method for determining mercury in blood with direct mercury analyzer. Methods: After the whole blood sample was extracted by solvent and removed by nitric acid, it was then measured by direct mercury analyzer. Results: After optimizing the conditions of the instrument, the linear range was 0.3-60.0 μg/L and the curve correlation coefficient was higher than 0.999. The lower limit of quantitations was 0.3 μg/L and the minimum quantitative concentration was 3.0 μg/L. The recovery and relative standard deviations (RSD) was 95.2%-97.6% and 1.4%-3.3%. Conclusion: The method is stable, reliable, easy to operate and has high sensitive. It can be used to determine mercury in blood.
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Affiliation(s)
- J P Yun
- Shenzhen Prevention and Treatment Center for Occupational Diseases, Shenzhen 518000, China
| | - T D Li
- Shenzhen Prevention and Treatment Center for Occupational Diseases, Shenzhen 518000, China
| | - F Liu
- Shenzhen Prevention and Treatment Center for Occupational Diseases, Shenzhen 518000, China
| | - W Q Zhang
- Shenzhen Prevention and Treatment Center for Occupational Diseases, Shenzhen 518000, China
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9
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Park Y, Jung Y, Li TD, Lao J, Tu RS, Chen X. β-Sheet Nanocrystals Dictate Water Responsiveness of Bombyx Mori Silk. Macromol Rapid Commun 2020; 41:e1900612. [PMID: 32125047 DOI: 10.1002/marc.201900612] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 02/12/2020] [Accepted: 02/20/2020] [Indexed: 12/12/2022]
Abstract
Water-responsive (WR) materials that strongly swell and shrink in response to changes in relative humidity (RH) have shown a great potential to serve as high-energy actuators for soft robotics and new energy-harvesting systems. However, the design criteria governing the scalable and high-efficiency WR actuation remain unclear, and thus inhibit further development of WR materials for practical applications. Nature has provided excellent examples of WR materials that contain stiff nanocrystalline structures that can be crucial to understand the fundamentals of WR behavior. This work reports that regenerated Bombyx (B.) mori silk can be processed to increase β-sheet crystallinity, which dramatically increases the WR energy density to 1.6 MJ m-3 , surpassing that of all known natural muscles, including mammalian muscles and insect muscles. Interestingly, the maximum water sorption decreases from 80.4% to 19.2% as the silk's β-sheet crystallinity increases from 19.7% to 57.6%, but the silk's WR energy density shows an eightfold increase with higher fractions of β-sheets. The findings of this study suggest that high crystallinity of silk reduces energy dissipation and translates the chemical potential of water-induced pressure to external loads more efficiently during the hydration/dehydration processes. Moreover, the availability of B. mori silk opens up possibilities for simple and scalable modification and production of powerful WR actuators.
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Affiliation(s)
- Yaewon Park
- Advanced Science Research Center (ASRC), City University of New York, 85, St. Nicholas Terrace, New York, NY, 10031, USA
| | - Yeojin Jung
- Advanced Science Research Center (ASRC), City University of New York, 85, St. Nicholas Terrace, New York, NY, 10031, USA.,Department of Chemical Engineering, The City College of New York, 160 Convent Avenue, New York, NY, 10031, USA
| | - Tai-De Li
- Advanced Science Research Center (ASRC), City University of New York, 85, St. Nicholas Terrace, New York, NY, 10031, USA.,Department of Physics, The City College of New York, 160 Convent Avenue, New York, NY, 10031, USA
| | - Jianpei Lao
- Department of Chemical Engineering, The City College of New York, 160 Convent Avenue, New York, NY, 10031, USA
| | - Raymond S Tu
- Advanced Science Research Center (ASRC), City University of New York, 85, St. Nicholas Terrace, New York, NY, 10031, USA.,Department of Chemical Engineering, The City College of New York, 160 Convent Avenue, New York, NY, 10031, USA
| | - Xi Chen
- Advanced Science Research Center (ASRC), City University of New York, 85, St. Nicholas Terrace, New York, NY, 10031, USA.,Department of Chemical Engineering, The City College of New York, 160 Convent Avenue, New York, NY, 10031, USA.,Ph.D. Program in Chemistry and Physics, The Graduate Center of the City University of New York, 365 5th Ave, New York, NY, 10016, USA
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10
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Li TD, Bieling P, Mullins D, Fletcher DA. Dynamics of Force-Regulated Branched Actin Network Density. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.2460] [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: 11/25/2022] Open
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11
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Zuo X, Xue Y, Zhou Y, Yin Y, Li TD, Wang L, Chuang YC, Chang CC, Rafailovich MH, Guo Y. The use of low cost, abundant, homopolymers for engineering degradable polymer blends: Compatibilization of poly(lactic acid)/styrenics using poly(methyl methacrylate). POLYMER 2020. [DOI: 10.1016/j.polymer.2019.122010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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12
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Yun JP, Zhang AH, Liu F, Li TD, Lin YR, Pan QY. [Elemental and isotopic determination of lead in whole blood by ISIS-ICP-MS]. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 2019; 37:619-622. [PMID: 31495121 DOI: 10.3760/cma.j.issn.1001-9391.2019.08.016] [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] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To establish a method for determination of lead and istope ratios in the blood by ISIS-ICP-MS. Methods: After wet digestion, the blood sample was on-line addition of thallium as internal standard and analyzed by ISIS-ICP-MS. Results: The limit of detection was 0.03 μg/L and the lower limit of quantification was 0.08 μg/L. The detection concentration was 0.45 μg/L and the minimum quantitative concentration was 1.49 μg/L. The relative standard deviations (RSD) were 0.3%~1.7%. The recovery was between 91.0% and 103.4%. The precision of the major lead isotope ratios was better than 0.3%. The calibrated isotope ratios of the standard liquid are close to the certificate. Conclusion: The method has a low detection limit, good precision and high accuracy, it is feasible for determination of lead concentration and isotope ratios in the bloune.
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Affiliation(s)
- J P Yun
- Shenzhen Prevention and Treatment center for Occupational Diseases, Shenzhen 518000, China
| | - A H Zhang
- Guangdong Province Hospital for Occupational Disease Prevention and Treatment, Guangzhou 510000, China
| | - F Liu
- Shenzhen Prevention and Treatment center for Occupational Diseases, Shenzhen 518000, China
| | - T D Li
- Shenzhen Prevention and Treatment center for Occupational Diseases, Shenzhen 518000, China
| | - Y R Lin
- Shenzhen Prevention and Treatment center for Occupational Diseases, Shenzhen 518000, China
| | - Q Y Pan
- Guangdong Province Hospital for Occupational Disease Prevention and Treatment, Guangzhou 510000, China
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13
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Li TD, Zhang W, Cai JM, Lin YR, Yun JP, Liu F. [Determination of Sevoflurane, Isoflurane and Enflurane in the air of workplace by gas chromatography]. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 2019; 37:453-456. [PMID: 31256530 DOI: 10.3760/cma.j.issn.1001-9391.2019.06.012] [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] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To establish a solvent desorption gas chromatographic method for determination of Sevoflurane, Isoflurane and Enflurane in the air of the Workplace. Methods: Sevoflurane, Isoflurane and Enflurane were collected with activated carbon tube and desorbed with dichloromethane, separated with DB-1 capillary columns, and then detected with flame ionization detector. Results: The linearity ranges were 1.9-304.8 μg/ml for Sevoflurane, 2.1-300.4 μg/ml for Isoflurane and 1.7-305.2 μg/ml for Enflurane, The correlation coefficient was both >0.999. Their limits of detection were 0.6 μg/ml, 0.6 μg/ml and 0.5 μg/ml, and Their limits of quatification were 1.9 μg/ml, 2.1 μg/ml and 1.7 μg/ml, and their minimum detectable concentrations were 0.1、0.2 and 0.1 mg/m(3) per 4.5 L of air. Their relative standard deviations (RSD) were 2.5%-3.0%, 2.3%-3.1% and 2.2%-3.0%. The average desorption efficiencies were 101.1%-103.3%, 100.7%-102.7% and 101.0%-102.9%. The sampling efficiency was both 100%. The breakthrough volume of 100 mg actived carbon was 3.7 mg, 3.4 mg and 3.4 mg. Sevoflurane, Isoflurane and Enflurane in activated carbon tube could be kept at least 10 days at room temperature without significant losses. Conclusion: The method shows lower detection limit, high accuracy and precision. It is feasible for determination of Sevoflurane, Isoflurane and Enflurane in the air of workplace.
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Affiliation(s)
- T D Li
- Prevention and Treatment Center for Occupational Diseases, Shenzhen 518001, China
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14
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Rywkin S, Korzun B, Adam J, Li TD. Raman and surface analysis studies of (CuGaSe 2) 0.8(CuAlSe 2) 0.2 single crystals. Acta Crystallogr A Found Adv 2019. [DOI: 10.1107/s205327331909209x] [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: 11/10/2022] Open
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15
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16
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Sousa AML, Li TD, Varghese S, Halling PJ, Aaron Lau KH. Highly Active Protein Surfaces Enabled by Plant-Based Polyphenol Coatings. ACS Appl Mater Interfaces 2018; 10:39353-39362. [PMID: 30299089 DOI: 10.1021/acsami.8b13793] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Proteins represent complex biomolecules capable of wide-ranging but also highly specific functionalities. Their immobilization on material supports can enable broad applications from sensing and industrial biocatalysis to biomedical interfaces and materials. We demonstrate the advantages of using aqueous-processed cross-linked polyphenol coatings for immobilizing proteins, including IgG, avidin, and various single and multidomain enzymes on diverse materials, to enable active biofunctional structures (e.g., ca. 2.2, 1.7, 1.1, and 4.8 mg·m-2 active phosphatase on nanoporous cellulose and alumina, steel mesh, and polyester fabric, respectively). Enzyme assays, X-ray photoelectron spectroscopy, silver staining, supplemented with contact angle, solid-state 13C NMR, HPLC, and ESI-MS measurements were used to characterize the polyphenols, coatings, and protein layers. We show that the functionalization process may be advantageously optimized directly for protein activity rather than the traditional focus on the thickness of the coating layer. Higher activities (by more than an order of magnitude in some cases) and wider process pH and material compatibility are demonstrated with polyphenol coatings than other approaches such as polydopamine. Coatings formed from different plant polyphenol extracts, even at lowered purity (and cost), were also found to be highly functional. Chemically, our results indicate that polyphenol coatings differ from polydopamine mainly because of the elimination of amine groups, and that polyphenol layers with intermediate levels of reactivity may better lead to high immobilized protein activity. Overall, an improved understanding of simple-to-use polyphenol coatings has been obtained, which enabled a significant development in active protein surfaces that may be applied across diverse materials and nanostructured supports.
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Affiliation(s)
- Ana M L Sousa
- WestCHEM/Department of Pure & Applied Chemistry , University of Strathclyde , 295 Cathedral Street , Glasgow G1 1XL , U.K
| | - Tai-De Li
- Advanced Science Research Center (ASRC) of Graduate Center and Department of Physics in City College of New York , CUNY , New York , New York 10031 , United States
| | - Sabu Varghese
- Department of Chemistry , Lancaster University , Lancaster LA1 4YB , U.K
| | - Peter J Halling
- WestCHEM/Department of Pure & Applied Chemistry , University of Strathclyde , 295 Cathedral Street , Glasgow G1 1XL , U.K
| | - King Hang Aaron Lau
- WestCHEM/Department of Pure & Applied Chemistry , University of Strathclyde , 295 Cathedral Street , Glasgow G1 1XL , U.K
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17
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Zarubin VA, Li TD, Humagain S, Ji H, Yager KG, Greenbaum SG, Vuong LT. Improved Anisotropic Thermoelectric Behavior of Poly(3,4-ethylenedioxythiophene):Poly(styrenesulfonate) via Magnetophoresis. ACS Omega 2018; 3:12554-12561. [PMID: 31457990 PMCID: PMC6644634 DOI: 10.1021/acsomega.8b00999] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 09/20/2018] [Indexed: 06/10/2023]
Abstract
There is strong demand for achieving morphological control of conducting polymers in its many potential applications, from energy harvesting to spintronics. Here, the static magnetic-field-induced alignment of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) particles is demonstrated. PEDOT:PSS thin films cast under modest mT-level magnetic fields exhibit a fourfold increase in the Seebeck coefficient and doubled electrical conductivity. Atomic force microscopy measurements confirm the presence of conducting islands that exhibit a 10-fold increase in the local charge carrier mobility and threshold behavior that is associated with phase separation. High-resolution scanning electron microscopy identifies a consistent structural coil-to-rod transition, and three-dimensional time-of-flight secondary-ion mass spectrometry imaging shows that the rodlike structures coincide with PEDOT domains that generally align with the magnetic field and cluster on the outer surface. Grazing-incidence small-angle X-ray scattering, Raman spectra, electron paramagnetic resonance, and circular dichroism spectroscopy point to the physical nature of the magnetophoretic alignment, which is expected to occur via magnetic coupling of PEDOT domains with polaron modes. Because casting under mT-level magnetic fields increases the electrical conductivity and Seebeck coefficient of PEDOT:PSS thin films without additional dopants that commonly limit the thermoelectric performance, our research reveals that low-field magnetophoresis significantly influences the structure and corresponding physical properties of PEDOT:PSS. Our results also point to concerns that the presence of small external magnetic fields in laboratory settings may appreciably and inadvertently influence the PEDOT:PSS morphology during settling, drying, or annealing processes.
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Affiliation(s)
- Vera A. Zarubin
- Bronx
High School of Science, 75 W 205th Street, Bronx, New York 10468, United
States
| | - Tai-De Li
- Department
of Physics, City College of New York and Advanced Science Research
Center, Graduate Center of the City University
of New York, 85 St Nicholas
Terrace, New York 10031, United States
| | - Sunita Humagain
- Department
of Physics, Hunter College of the
City University of New York, 695 Park Avenue, New York, New York 10065, United
States
- Department
of Physics, Graduate Center of the City
University of New York, 365 5th Avenue, New York, New York 10016, United
States
| | - Haojie Ji
- Department
of Physics, Queens College of the
City University of New York, 65-30 Kissena Blvd, Flushing, New York 11367, United
States
| | - Kevin G. Yager
- Center
for Functional Nanomaterials, Brookhaven
National Laboratory, Upton, New York 11973, United States
| | - Steven G. Greenbaum
- Department
of Physics, Hunter College of the
City University of New York, 695 Park Avenue, New York, New York 10065, United
States
- Department
of Physics, Graduate Center of the City
University of New York, 365 5th Avenue, New York, New York 10016, United
States
| | - Luat T. Vuong
- Department
of Physics, Queens College of the
City University of New York, 65-30 Kissena Blvd, Flushing, New York 11367, United
States
- Department
of Physics, Graduate Center of the City
University of New York, 365 5th Avenue, New York, New York 10016, United
States
- Department
of Mechanical Engineering, University of
California at Riverside, Bourns Hall, Riverside, California 92521, United States
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18
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Lin YR, Li TD, Liu F, Yun JP, Xie YX, Chen JH. [Simultaneous determination of various volatile organic compounds in urine by headspace GC-MS]. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 2018; 36:305-307. [PMID: 29996258 DOI: 10.3760/cma.j.issn.1001-9391.2018.04.019] [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] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To establish a method for determination of acetone, dichloromethane, hexane, 1, 1, 1-trichloroethane, 1, 2-dichloroethane, benzene, toluene, ethylbenzene etc organic compounds in urine by headspace gas chromatography-mass spectrometry (GC-MS) . Methods: Headspace gases of urine samples were injected into GC and determined by mass. Results: Determination of urine components were in a good linear range in their concentration range of this method. The correlation coefficients were between 0.996 and 1.000 with the detection limits between 0.1 μg/L and 4.5 μg/L, the precisions were between 1.3% and 4.6%, the recovery rates were between 86.2% and 97.4%. Conclusion: This method has the advantages of low detection limits, high accuracy, high precision and simple pretreatment, which is suitable for the determination of the content of various volatile organic compounds in urine.
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Affiliation(s)
- Y R Lin
- Shenzhen Prevention and Treatment center for Occupational Diseases, Shenzhen 518001, China
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19
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Li TD, Liu F, Pan XF, Tao X, Zhao W, Yan HF. [Determination of methylenedianiline in urine by high performance liquid chromatography-tandemmass spectrometry]. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 2018; 36:308-311. [PMID: 29996259 DOI: 10.3760/cma.j.issn.1001-9391.2018.04.020] [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] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To develop a method for determination of metabolites of diphenylmethane diisocyanate (MDI) in urine, i.e. methylenedianiline (MDA) by high performance liquid chromatography-tandem mass (LC-MS-MS) . Methods: Urine samples were prepared by hydrolyzation with sulfuric acid and extraction by acetonitrile, and then separated on a Shim-pack XR-ODS column, analyzed with high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) . The external solvent standard calibration were tested. Results: The linearity ranges were 0.05~20.00 μg/L, The related coefficients were 0.999 5. The limit of detection was 0.02 μg/L. The rats of recovery were 91.0%~103.4%. The relative standard deviations were between 2.7%~7.3%. Conclusion: The method was sensitive, accurate and suitable for the MDA determination in urine of MDI exposed population.
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Affiliation(s)
- T D Li
- Shenzhen Prevention and Treatment center for Occupational Diseases, Shenzhen 518001, China
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20
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Li TD, Zhang S, Liu F, Guo X, Tian DC, Chen JH. [Simultaneous determination of 12 rodenticides in whole blood and urine samples by high performance liquid chromatography-tandemmass spectrometry]. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 2018; 36:538-541. [PMID: 30248773 DOI: 10.3760/cma.j.issn.1001-9391.2018.07.017] [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] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Objective: To develop a method for Simultaneous and rapid determination of 12 rodenticides including pindone, vacor, coumatetralyl, warfarin, diphacinone, coumachlor, chlorphacinon, difenacoum, brodifacoum, bromadiolone, difethialone and flocoumafen in whole blood and urine samples by high performance liquid chromatography-tandem mass (LC-MS-MS) . Methods: The whole blood samples were precipitated with acetonitrile, purified by OstroTM 96-well plate, The urine samples were extracted by acetonitrile, and then separated on a ODS column, analyzed with high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) . The external standard calibration were tested. Results: A good linearity was observed in their respective concentration ranges of 12 rodenticides. The related coefficients were 0.993 0~0.999 8. The limit of detections were 0.05 μg/L~1.4 μg/L. The rates of recovery were 92.5%~118.0%. The relative standard deviations were between 0.8%~17.3%. Conclusion: The method was simple, rapid, sensitive, accurate and suitable for simultaneous detection of the 12 rodenticides in whole blood and urine samples of intoxicated patients.
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Affiliation(s)
- T D Li
- Shenzhen Prevention and Treatment center for Occupational Diseases, Shenzhen 518001, China
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21
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Lavini F, Calò A, Gao Y, Albisetti E, Li TD, Cao T, Li G, Cao L, Aruta C, Riedo E. Friction and work function oscillatory behavior for an even and odd number of layers in polycrystalline MoS 2. Nanoscale 2018; 10:8304-8312. [PMID: 29687826 DOI: 10.1039/c8nr00238j] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A large effort is underway to investigate the properties of two-dimensional (2D) materials for their potential to become building blocks in a variety of integrated nanodevices. In particular, the ability to understand the relationship between friction, adhesion, electric charges and defects in 2D materials is of key importance for their assembly and use in nano-electro-mechanical and energy harvesting systems. Here, we report on a new oscillatory behavior of nanoscopic friction in continuous polycrystalline MoS2 films for an odd and even number of atomic layers, where odd layers show higher friction and lower work function. Friction force microscopy combined with Kelvin probe force microscopy and X-ray photoelectron spectroscopy demonstrates that an enhanced adsorption of charges and OH molecules is at the origin of the observed increase in friction for 1 and 3 polycrystalline MoS2 layers. In polycrystalline films with an odd number of layers, each crystalline nano-grain carries a dipole due to the MoS2 piezoelectricity, therefore charged molecules adsorb at the grain boundaries all over the surface of the continuous MoS2 film. Their displacement during the sliding of a nano-size tip gives rise to the observed enhanced dissipation and larger nanoscale friction for odd layer-numbers. Similarly, charged adsorbed molecules are responsible for the work function decrease in odd layer-number.
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Affiliation(s)
- Francesco Lavini
- Advanced Science Research Center, City University of New York, 85 St Nicholas Terrace, New York, New York 10031, USA.
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22
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Lampel A, McPhee SA, Park HA, Scott GG, Humagain S, Hekstra DR, Yoo B, Frederix PWJM, Li TD, Abzalimov RR, Greenbaum SG, Tuttle T, Hu C, Bettinger CJ, Ulijn RV. Polymeric peptide pigments with sequence-encoded properties. Science 2018; 356:1064-1068. [PMID: 28596363 DOI: 10.1126/science.aal5005] [Citation(s) in RCA: 203] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 05/08/2017] [Indexed: 12/19/2022]
Abstract
Melanins are a family of heterogeneous polymeric pigments that provide ultraviolet (UV) light protection, structural support, coloration, and free radical scavenging. Formed by oxidative oligomerization of catecholic small molecules, the physical properties of melanins are influenced by covalent and noncovalent disorder. We report the use of tyrosine-containing tripeptides as tunable precursors for polymeric pigments. In these structures, phenols are presented in a (supra-)molecular context dictated by the positions of the amino acids in the peptide sequence. Oxidative polymerization can be tuned in a sequence-dependent manner, resulting in peptide sequence-encoded properties such as UV absorbance, morphology, coloration, and electrochemical properties over a considerable range. Short peptides have low barriers to application and can be easily scaled, suggesting near-term applications in cosmetics and biomedicine.
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Affiliation(s)
- Ayala Lampel
- Advanced Science Research Center at the Graduate Center of the City University of New York, 85 Saint Nicholas Terrace, New York, NY 10031, USA
| | - Scott A McPhee
- Advanced Science Research Center at the Graduate Center of the City University of New York, 85 Saint Nicholas Terrace, New York, NY 10031, USA
| | - Hang-Ah Park
- Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA
| | - Gary G Scott
- WestCHEM and Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, UK
| | - Sunita Humagain
- Department of Physics and Astronomy, Hunter College, City University of New York, 695 Park Avenue, New York, NY 10065, USA.,Ph.D. programs in Biochemistry, Chemistry and Physics, The Graduate Center of the City University of New York, NY 10016, USA
| | - Doeke R Hekstra
- Department of Molecular and Cellular Biology, School of Engineering and Applied Sciences, FAS Center for Systems Biology, Harvard University, Cambridge, MA 02138, USA
| | - Barney Yoo
- Department of Chemistry, Hunter College, City University of New York, 695 Park Avenue, New York, NY 10065, USA
| | - Pim W J M Frederix
- Groningen Biomolecular Sciences and Biotechnology Institute, Rijksuniversiteit Groningen, Groningen, Netherlands
| | - Tai-De Li
- Advanced Science Research Center at the Graduate Center of the City University of New York, 85 Saint Nicholas Terrace, New York, NY 10031, USA
| | - Rinat R Abzalimov
- Advanced Science Research Center at the Graduate Center of the City University of New York, 85 Saint Nicholas Terrace, New York, NY 10031, USA
| | - Steven G Greenbaum
- Department of Physics and Astronomy, Hunter College, City University of New York, 695 Park Avenue, New York, NY 10065, USA.,Ph.D. programs in Biochemistry, Chemistry and Physics, The Graduate Center of the City University of New York, NY 10016, USA
| | - Tell Tuttle
- WestCHEM and Department of Pure and Applied Chemistry, University of Strathclyde, 295 Cathedral Street, Glasgow G1 1XL, UK
| | - Chunhua Hu
- Department of Chemistry, Silver Center for Arts and Science, 100 Washington Square East, New York University, New York, NY 10003, USA
| | - Christopher J Bettinger
- Department of Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA.,Department of Biomedical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA.,McGowan Institute of Regenerative Medicine, 450 Technology Drive, Suite 300, Pittsburgh, PA 15219, USA
| | - Rein V Ulijn
- Advanced Science Research Center at the Graduate Center of the City University of New York, 85 Saint Nicholas Terrace, New York, NY 10031, USA. .,Ph.D. programs in Biochemistry, Chemistry and Physics, The Graduate Center of the City University of New York, NY 10016, USA.,Department of Chemistry, Hunter College, City University of New York, 695 Park Avenue, New York, NY 10065, USA
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23
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Bieling P, Hansen SD, Akin O, Li TD, Hayden CC, Fletcher DA, Mullins RD. WH2 and proline-rich domains of WASP-family proteins collaborate to accelerate actin filament elongation. EMBO J 2017; 37:102-121. [PMID: 29141912 PMCID: PMC5753033 DOI: 10.15252/embj.201797039] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 09/19/2017] [Accepted: 09/20/2017] [Indexed: 02/04/2023] Open
Abstract
WASP‐family proteins are known to promote assembly of branched actin networks by stimulating the filament‐nucleating activity of the Arp2/3 complex. Here, we show that WASP‐family proteins also function as polymerases that accelerate elongation of uncapped actin filaments. When clustered on a surface, WASP‐family proteins can drive branched actin networks to grow much faster than they could by direct incorporation of soluble monomers. This polymerase activity arises from the coordinated action of two regulatory sequences: (i) a WASP homology 2 (WH2) domain that binds actin, and (ii) a proline‐rich sequence that binds profilin–actin complexes. In the absence of profilin, WH2 domains are sufficient to accelerate filament elongation, but in the presence of profilin, proline‐rich sequences are required to support polymerase activity by (i) bringing polymerization‐competent actin monomers in proximity to growing filament ends, and (ii) promoting shuttling of actin monomers from profilin–actin complexes onto nearby WH2 domains. Unoccupied WH2 domains transiently associate with free filament ends, preventing their growth and dynamically tethering the branched actin network to the WASP‐family proteins that create it. Collaboration between WH2 and proline‐rich sequences thus strikes a balance between filament growth and tethering. Our work expands the number of critical roles that WASP‐family proteins play in the assembly of branched actin networks to at least three: (i) promoting dendritic nucleation; (ii) linking actin networks to membranes; and (iii) accelerating filament elongation.
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Affiliation(s)
- Peter Bieling
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, CA, USA .,Department of Bioengineering & Biophysics Program, University of California, Berkeley, CA, USA.,Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Scott D Hansen
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, CA, USA
| | - Orkun Akin
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, CA, USA
| | - Tai-De Li
- Department of Bioengineering & Biophysics Program, University of California, Berkeley, CA, USA.,Chan Zuckerberg Biohub, San Francisco, CA, USA.,Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | - Daniel A Fletcher
- Department of Bioengineering & Biophysics Program, University of California, Berkeley, CA, USA .,Chan Zuckerberg Biohub, San Francisco, CA, USA.,Biological Systems & Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - R Dyche Mullins
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, CA, USA
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Abstract
Protein-coated microbeads provide a consistent approach for activating and expanding populations of T cells for immunotherapy but do not fully capture the properties of antigen presenting cells. In this report, we enhance T cell expansion by replacing the conventional, rigid bead with a mechanically soft elastomer. Polydimethylsiloxane (PDMS) was prepared in a microbead format and modified with activating antibodies to CD3 and CD28. A total of three different formulations of PDMS provided an extended proliferative phase in both CD4+-only and mixed CD4+-CD8+ T cell preparations. CD8+ T cells retained cytotoxic function, as measured by a set of biomarkers (perforin production, LAMP2 mobilization, and IFN-γ secretion) and an in vivo assay of targeted cell killing. Notably, PDMS beads presented a nanoscale polymer structure and higher rigidity than that associated with conventional bulk material. These data suggest T cells respond to this higher rigidity, indicating an unexpected effect of curing conditions. Together, these studies demonstrate that adopting mechanobiology ideas into the bead platform can provide new tools for T cell based immunotherapy.
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Affiliation(s)
- Lester H. Lambert
- Department of Biomedical Engineering, Columbia University, New York,
NY 10027, USA
| | | | - Sarah E. De Leo
- Department of Biomedical Engineering, Columbia University, New York,
NY 10027, USA
| | - Roddy S. O’Connor
- Department of Pathology and Laboratory Medicine, Perelman School of
Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Selene Nunez-Cruz
- Center for Cellular Immunotherapies, Perelman School of Medicine at
the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tai-De Li
- Advanced Science Research Center of CUNY, New York, NY 10031
| | - Jinglun Yuan
- Department of Biomedical Engineering, Columbia University, New York,
NY 10027, USA
| | - Michael C. Milone
- Department of Pathology and Laboratory Medicine, Perelman School of
Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
- Center for Cellular Immunotherapies, Perelman School of Medicine at
the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Lance C. Kam
- Department of Biomedical Engineering, Columbia University, New York,
NY 10027, USA
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25
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Gurarslan A, Jiao S, Li TD, Li G, Yu Y, Gao Y, Riedo E, Xu Z, Cao L. Van der Waals Force Isolation of Monolayer MoS 2. Adv Mater 2016; 28:10055-10060. [PMID: 27690280 DOI: 10.1002/adma.201601581] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2016] [Revised: 07/07/2016] [Indexed: 06/06/2023]
Abstract
Monolayer MoS2 can effectively screen the vdW interaction of underlying substrates with external systems by >90% because of the substantial increase in the separation between the substrate and external systems due to the presence of the monolayer. This substantial screening of vdW interactions by MoS2 monolayer is different from what reported at graphene.
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Affiliation(s)
- Alper Gurarslan
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
- Department of Fiber and Polymer Science, North Carolina State University, Raleigh, NC, 27695, USA
| | - Shuping Jiao
- Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China
| | - Tai-De Li
- CUNY-Advanced Science Research Center, New York, NY, 10031, USA
- School of Physics, Georgia Institue of Technology, Atlanta, GA, 30332, USA
| | - Guoqing Li
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
- Department of Fiber and Polymer Science, North Carolina State University, Raleigh, NC, 27695, USA
| | - Yiling Yu
- Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA
| | - Yang Gao
- CUNY-Advanced Science Research Center, New York, NY, 10031, USA
- School of Physics, Georgia Institue of Technology, Atlanta, GA, 30332, USA
| | - Elisa Riedo
- CUNY-Advanced Science Research Center, New York, NY, 10031, USA
- School of Physics, Georgia Institue of Technology, Atlanta, GA, 30332, USA
- Department of Physics, CUNY-City College of New York, New York, NY, 10031, USA
- Phyics Program, CUNY-The Graduate Center, New York, NY, 10016, USA
| | - Zhiping Xu
- Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China
| | - Linyou Cao
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
- Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA
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26
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Abstract
Monolayer MoS2 can effectively screen the vdW interaction of underlying substrates with external systems by >90% because of the substantial increase in the separation between the substrate and external systems due to the presence of the monolayer. This substantial screening of vdW interactions by MoS2 monolayer is different from what reported at graphene.
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Affiliation(s)
- Alper Gurarslan
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
- Department of Fiber and Polymer Science, North Carolina State University, Raleigh, NC, 27695, USA
| | - Shuping Jiao
- Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China
| | - Tai-De Li
- CUNY-Advanced Science Research Center, New York, NY, 10031, USA
- School of Physics, Georgia Institue of Technology, Atlanta, GA, 30332, USA
| | - Guoqing Li
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
- Department of Fiber and Polymer Science, North Carolina State University, Raleigh, NC, 27695, USA
| | - Yiling Yu
- Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA
| | - Yang Gao
- CUNY-Advanced Science Research Center, New York, NY, 10031, USA
- School of Physics, Georgia Institue of Technology, Atlanta, GA, 30332, USA
| | - Elisa Riedo
- CUNY-Advanced Science Research Center, New York, NY, 10031, USA
- School of Physics, Georgia Institue of Technology, Atlanta, GA, 30332, USA
- Department of Physics, CUNY-City College of New York, New York, NY, 10031, USA
- Phyics Program, CUNY-The Graduate Center, New York, NY, 10016, USA
| | - Zhiping Xu
- Department of Mechanical Engineering, Tsinghua University, Beijing, 100084, China
| | - Linyou Cao
- Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC, 27695, USA
- Department of Physics, North Carolina State University, Raleigh, NC, 27695, USA
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Li TD, Liu F, Xie YX, Chen JH. [Determination of tert-butyl alcohol in the air of the workplace by solvent desorption gas chromatography]. Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi 2016; 34:615-617. [PMID: 27682673 DOI: 10.3760/cma.j.issn.1001-9391.2016.08.016] [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] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Objective: To establish solvent desorption gas chromatographic method for determination of tert-butyl alcohol in the air of the workplace. Methods: After tert-butyl alcohol in the air of the workplace collected with activated carbon tube and desorbed with 2% 2-propanol in CS2, and then separated with DB-FFAP capillary column and detected with flame ionization detector. Results: The linearity ranges were 0.6~2 264.0 mg/L. The limit of quantification was 0.6 mg/L. The determination has a good reproducibility. The intraassay and interassay precisions were 2.8%~3.2% and 3.8%~5.7%. The desorption efficiencies were 93.9%~98.1%. Absorption efficiencies were 95.8%~100.0%. The breakthrough volume was above 7.1 mg in 100mg activated carbon. The samples in activated carbon tube could be stored for at least 14 days at ambient temperature. Conclusion: The method is feasible for determination of tert-butyl alcohol in the air of the workplace.
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Affiliation(s)
- T D Li
- Shenzhen Prevention and Treatment center for Occupational Diseases, Shenzhen 518001, China
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Bieling P, Li TD, Weichsel J, McGorty R, Jreij P, Huang B, Fletcher DA, Mullins RD. Force Feedback Controls Motor Activity and Mechanical Properties of Self-Assembling Branched Actin Networks. Cell 2016; 164:115-127. [PMID: 26771487 DOI: 10.1016/j.cell.2015.11.057] [Citation(s) in RCA: 167] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 11/12/2015] [Accepted: 11/23/2015] [Indexed: 01/07/2023]
Abstract
Branched actin networks--created by the Arp2/3 complex, capping protein, and a nucleation promoting factor--generate and transmit forces required for many cellular processes, but their response to force is poorly understood. To address this, we assembled branched actin networks in vitro from purified components and used simultaneous fluorescence and atomic force microscopy to quantify their molecular composition and material properties under various forces. Remarkably, mechanical loading of these self-assembling materials increases their density, power, and efficiency. Microscopically, increased density reflects increased filament number and altered geometry but no change in average length. Macroscopically, increased density enhances network stiffness and resistance to mechanical failure beyond those of isotropic actin networks. These effects endow branched actin networks with memory of their mechanical history that shapes their material properties and motor activity. This work reveals intrinsic force feedback mechanisms by which mechanical resistance makes self-assembling actin networks stiffer, stronger, and more powerful.
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Affiliation(s)
- Peter Bieling
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, Genentech Hall, 600 16(th) Street, San Francisco, CA 94158, USA; Department of Bioengineering and Biophysics Program, University of California, Berkeley, 648 Stanley Hall MC 1762, Berkeley, CA 94720, USA
| | - Tai-De Li
- Department of Bioengineering and Biophysics Program, University of California, Berkeley, 648 Stanley Hall MC 1762, Berkeley, CA 94720, USA; Physical Biosciences Division, Lawrence Berkeley National Laboratory, 648 Stanley Hall MC 1762, Berkeley, CA 94720, USA; Advance Science Research Center, City University of New York, 85 St. Nicholas Terrace, New York, NY 10031, USA
| | - Julian Weichsel
- Department of Chemistry, University of California, Berkeley, 207 Gilman Hall, Berkeley, CA 94720, USA
| | - Ryan McGorty
- Department of Biochemistry and Biophysics, University of California, San Francisco, Genentech Hall, 600 16(th) Street, San Francisco, CA 94158, USA
| | - Pamela Jreij
- Department of Bioengineering and Biophysics Program, University of California, Berkeley, 648 Stanley Hall MC 1762, Berkeley, CA 94720, USA
| | - Bo Huang
- Department of Biochemistry and Biophysics, University of California, San Francisco, Genentech Hall, 600 16(th) Street, San Francisco, CA 94158, USA
| | - Daniel A Fletcher
- Department of Bioengineering and Biophysics Program, University of California, Berkeley, 648 Stanley Hall MC 1762, Berkeley, CA 94720, USA; Physical Biosciences Division, Lawrence Berkeley National Laboratory, 648 Stanley Hall MC 1762, Berkeley, CA 94720, USA.
| | - R Dyche Mullins
- Department of Cellular and Molecular Pharmacology and Howard Hughes Medical Institute, University of California, San Francisco, Genentech Hall, 600 16(th) Street, San Francisco, CA 94158, USA.
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29
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Li TD, Chiu HC, Ortiz-Young D, Riedo E. Nanorheology by atomic force microscopy. Rev Sci Instrum 2014; 85:123707. [PMID: 25554301 DOI: 10.1063/1.4903353] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2014] [Accepted: 11/24/2014] [Indexed: 06/04/2023]
Abstract
We present an Atomic Force Microscopy (AFM) based method to investigate the rheological properties of liquids confined within a nanosize gap formed by an AFM tip apex and a solid substrate. In this method, a conventional AFM cantilever is sheared parallel to a substrate surface by means of a lock-in amplifier while it is approaching and retracting from the substrate in liquid. The normal solvation forces and lateral viscoelastic shear forces experienced by the AFM tip in liquid can be simultaneously measured as a function of the tip-substrate distance with sub-nanometer vertical resolution. A new calibration method is applied to compensate for the linear drift of the piezo transducer and substrate system, leading to a more precise determination of the tip-substrate distance. By monitoring the phase lag between the driving signal and the cantilever response in liquid, the frequency dependent viscoelastic properties of the confined liquid can also be derived. Finally, we discuss the results obtained with this technique from different liquid-solid interfaces. Namely, octamethylcyclotetrasiloxane and water on mica and highly oriented pyrolytic graphite.
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Affiliation(s)
- Tai-De Li
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Hsiang-Chih Chiu
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Deborah Ortiz-Young
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
| | - Elisa Riedo
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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30
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Clausen CH, Brooks MD, Li TD, Grob P, Kemalyan G, Nogales E, Niyogi KK, Fletcher DA. Dynamic mechanical responses of Arabidopsis thylakoid membranes during PSII-specific illumination. Biophys J 2014; 106:1864-70. [PMID: 24806918 PMCID: PMC4017268 DOI: 10.1016/j.bpj.2014.03.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [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] [Received: 09/03/2013] [Revised: 02/25/2014] [Accepted: 03/10/2014] [Indexed: 10/25/2022] Open
Abstract
Remodeling of thylakoid membranes in response to illumination is an important process for the regulation of photosynthesis. We investigated the thylakoid network from Arabidopsis thaliana using atomic force microscopy to capture dynamic changes in height, elasticity, and viscosity of isolated thylakoid membranes caused by changes in illumination. We also correlated the mechanical response of the thylakoid network with membrane ultrastructure using electron microscopy. We find that the elasticity of the thylakoid membranes increases immediately upon PSII-specific illumination, followed by a delayed height change. Direct visualization by electron microscopy confirms that there is a significant change in the packing repeat distance of the membrane stacks in response to illumination. Although experiments with Gramicidin show that the change in elasticity depends primarily on the transmembrane pH gradient, the height change requires both the pH gradient and STN7-kinase-dependent phosphorylation of LHCII. Our studies indicate that lumen expansion in response to illumination is not simply a result of the influx of water, and we propose a dynamic model in which protein interactions within the lumen drive these changes.
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Affiliation(s)
- Casper H Clausen
- Bioengineering Department, University of California, Berkeley, California
| | - Matthew D Brooks
- Department of Plant and Microbial Biology, University of California, Berkeley, California; Howard Hughes Medical Institute, University of California, Berkeley, California
| | - Tai-De Li
- Bioengineering Department, University of California, Berkeley, California
| | - Patricia Grob
- Howard Hughes Medical Institute, University of California, Berkeley, California
| | - Gigi Kemalyan
- Howard Hughes Medical Institute, University of California, Berkeley, California
| | - Eva Nogales
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California; Molecular and Cell Biology Department, University of California, Berkeley, California; Howard Hughes Medical Institute, University of California, Berkeley, California
| | - Krishna K Niyogi
- Department of Plant and Microbial Biology, University of California, Berkeley, California; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California; Howard Hughes Medical Institute, University of California, Berkeley, California
| | - Daniel A Fletcher
- Bioengineering Department, University of California, Berkeley, California; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California.
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Abstract
Interactions between antiparallel microtubules are essential for the organization of spindles in dividing cells. The ability to form immobilized antiparallel microtubule pairs in vitro, combined with the ability to image them via TIRF microscopy, permits detailed biochemical characterization of microtubule cross-linking proteins and their effects on microtubule dynamics. Here, we describe methods for chemical micropatterning of microtubule seeds on glass surfaces in configurations that specifically promote the formation of antiparallel microtubule overlaps in vitro. We demonstrate that this assay is especially well suited for reconstitution of minimal midzone overlaps stabilized by the antiparallel microtubule cross-linking protein PRC1 and its binding partners. The micropatterning method is suitable for use with a broad range of proteins, and the assay is generally applicable to any microtubule cross-linking protein.
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Affiliation(s)
- Franck J Fourniol
- London Research Institute, Cancer Research UK, London, United Kingdom
| | - Tai-De Li
- Department of Bioengineering and Biophysics Group, University of California-Berkeley, Berkeley, California, USA
| | - Peter Bieling
- Department of Bioengineering and Biophysics Group, University of California-Berkeley, Berkeley, California, USA; Department of Cellular and Molecular Pharmacology, University of California-San Francisco, San Francisco, California, USA
| | - R Dyche Mullins
- Department of Cellular and Molecular Pharmacology, University of California-San Francisco, San Francisco, California, USA; Howard Hughes Medical Institute, Chevy Chase, Maryland, USA
| | - Daniel A Fletcher
- Department of Bioengineering and Biophysics Group, University of California-Berkeley, Berkeley, California, USA.
| | - Thomas Surrey
- London Research Institute, Cancer Research UK, London, United Kingdom.
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32
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Li TD, Clausen C, Brooks M, Grob P, Kemalyan G, Nogales E, Nyogi K, Fletcher D. Dynamic Mechanical Responses of Arabidopsis Thylakoid Membranes during PSII-Specific Illumination. Biophys J 2014. [DOI: 10.1016/j.bpj.2013.11.1023] [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: 10/23/2022] Open
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33
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Li TD, Bieling P, Fletcher DA, Mullins D. The Mechanical Properties of Dendritic Actin Network Assembly under Different Forces. Biophys J 2013. [DOI: 10.1016/j.bpj.2012.11.795] [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: 10/27/2022] Open
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34
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Lam WA, Chaudhuri O, Crow A, Webster KD, Li TD, Kita A, Huang J, Fletcher DA. Mechanics and contraction dynamics of single platelets and implications for clot stiffening. Nat Mater 2011; 10:61-6. [PMID: 21131961 PMCID: PMC3236662 DOI: 10.1038/nmat2903] [Citation(s) in RCA: 241] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2010] [Accepted: 10/22/2010] [Indexed: 05/20/2023]
Abstract
Platelets interact with fibrin polymers to form blood clots at sites of vascular injury. Bulk studies have shown clots to be active materials, with platelet contraction driving the retraction and stiffening of clots. However, neither the dynamics of single-platelet contraction nor the strength and elasticity of individual platelets, both of which are important for understanding clot material properties, have been directly measured. Here we use atomic force microscopy to measure the mechanics and dynamics of single platelets. We find that platelets contract nearly instantaneously when activated by contact with fibrinogen and complete contraction within 15 min. Individual platelets can generate an average maximum contractile force of 29 nN and form adhesions stronger than 70 nN. Our measurements show that when exposed to stiffer microenvironments, platelets generated higher stall forces, which indicates that platelets may be able to contract heterogeneous clots more uniformly. The high elasticity of individual platelets, measured to be 10 kPa after contraction, combined with their high contractile forces, indicates that clots may be stiffened through direct reinforcement by platelets as well as by strain stiffening of fibrin under tension due to platelet contraction. These results show how the mechanosensitivity and mechanics of single cells can be used to dynamically alter the material properties of physiologic systems.
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Affiliation(s)
- Wilbur A. Lam
- Department of Bioengineering, University of California, Berkeley, California 94720, USA
- Department of Pediatrics, Division of Pediatric Hematology/Oncology, University of California, San Francisco, California 94143, USA
| | - Ovijit Chaudhuri
- Department of Bioengineering, University of California, Berkeley, California 94720, USA
| | - Ailey Crow
- Graduate group in Biophysics, University of California, Berkeley, California 94720, USA
| | - Kevin D. Webster
- Graduate group in Biophysics, University of California, Berkeley, California 94720, USA
| | - Tai-De Li
- Department of Bioengineering, University of California, Berkeley, California 94720, USA
| | - Ashley Kita
- Department of Bioengineering, University of California, Berkeley, California 94720, USA
| | - James Huang
- Department of Pediatrics, Division of Pediatric Hematology/Oncology, University of California, San Francisco, California 94143, USA
| | - Daniel A. Fletcher
- Department of Bioengineering, University of California, Berkeley, California 94720, USA
- Graduate group in Biophysics, University of California, Berkeley, California 94720, USA
- Correspondence and requests for materials should be addressed to D.A.F.
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35
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Li TD, Inigo AR, Fann W, White JD, Huang YF, Wei PK. Development of a Controlled Environment Near-Field Optical Microscope for Organic Thin Film Studies. J CHIN CHEM SOC-TAIP 2010. [DOI: 10.1002/jccs.201000069] [Citation(s) in RCA: 1] [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: 11/09/2022]
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36
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Abstract
The viscoelastic dynamics of nanoconfined wetting liquids is studied by means of atomic force microscopy. We observe a nonlinear viscoelastic behavior remarkably similar to that widely observed in metastable complex fluids. We show that the origin of the measured nonlinear viscoelasticity in nanoconfined water and silicon oil is a strain rate dependent relaxation time and slow dynamics. By measuring the viscoelastic modulus at different frequencies and strains, we find that the intrinsic relaxation time of nanoconfined water is in the range 0.1-0.0001 s, orders of magnitude longer than that of bulk water, and comparable to the dielectric relaxation time measured in supercooled water at 170-210 K.
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Affiliation(s)
- Tai-De Li
- School of Physics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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37
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Szoszkiewicz R, Okada T, Jones SC, Li TD, King WP, Marder SR, Riedo E. High-speed, sub-15 nm feature size thermochemical nanolithography. Nano Lett 2007; 7:1064-9. [PMID: 17385937 DOI: 10.1021/nl070300f] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We report a nanolithography technique that allows simultaneous direct control of the local chemistry and topography of thin polymer films. Specifically, a heated atomic force microscope (AFM) tip can write sub-15 nm hydrophilic features onto a hydrophobic polymer at the rate of 1.4 mm per s. The thermally activated chemical reactions and topography changes depend on the chemical composition of the polymer, the raster speed, the temperature at the AFM tip/sample interface, and the normal load. This method is conceptually simple, direct, extremely rapid, achievable in a range of environments, and potentially adaptable to other materials systems.
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Affiliation(s)
- Robert Szoszkiewicz
- School of Physics and Center for Organic Photonics and Electronics, Georgia Institute of Technology, Atlanta, Georgia 30332, USA
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Feng QZ, Li TD, Wei LX, Qiao X, Yi J, Wang L, Yang TS. Tempero-spatial dissociation between the expression of Fas and apoptosis after coronary occlusion. Mol Pathol 2004; 56:362-7. [PMID: 14645700 PMCID: PMC1187357 DOI: 10.1136/mp.56.6.362] [Citation(s) in RCA: 7] [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: 12/20/2022]
Abstract
AIMS To explore the role of Fas in cardiomyocytic apoptosis induced by ischaemia through determining the histological relation between Fas expression and apoptosis in rat myocardium during ischaemia/infarction. METHODS The myocardial ischaemia model was produced by ligating the left coronary artery in Sprague-Dawley rats. The rats were killed from 10 minutes to seven days after surgery. Apoptotic myocardial cells were detected by the in situ terminal deoxynucleotidyl transferase mediated nick end labelling method, and the expression of Fas by immunohistochemistry and western blotting. RESULTS Cardiomyocytic apoptosis appeared from three to 36 hours after ischaemia. The expression of Fas could be detected by western blot from before surgery to seven days of ischaemia. Apoptosis and the expression of Fas in the cardiomyocytes appeared in different regions of the myocardium: apoptosis in the ischaemic region, Fas in the regions surrounding ischaemic myocardium. CONCLUSION These results suggest that there is a tempero-spatial dissociation between the expression of Fas and apoptosis after coronary occlusion. Fas might not directly regulate the apoptosis of cardiomyocytes induced by ischaemia.
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Affiliation(s)
- Q Z Feng
- Department of Cardiology, General Hospital of Chinese PLA, 28 Fuxing Road, Beijing 100853, China.
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39
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Li TD. [Views on a non-endemic area for filariasis in Yunan Province]. Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2000; 18:196. [PMID: 12567655] [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: 04/20/2023]
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40
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Abstract
The importance of sequential events which lead to skin necrosis has significant implications in trauma, vascular injury, and wound healing. In this series of experiments, we tested the hypothesis that xanthine oxidase (XO) activity was increased along an ischemic gradient of a skin flap and that the XO enzyme activity correlated with an increase in neutrophils. There were two animal groups in which the skin flaps were raised and assayed at 0, 1, or 6 hr. In the other group, they were created as bipedicle flaps for 7 days, before the distal attachment was divided and the tissue assayed. In the acutely raised flaps, some animals were treated with the XO inhibitor, allopurinol. Xanthine dehydrogenase (XD) and XO activity was measured with a fluorometric pterin assay and neutrophil concentration was measured using a myeloperoxidase marker. In this model, there was consistent skin necrosis in the distal end of the skin flap (48 +/- 8%). The data showed that both XD and XO activity in the distal ends was statistically significantly increased over the sham control or proximal ends of the skin flaps at 1 hr (P < 0.05). XO activity remained elevated in the distal ends at 6 hr. Allopurinol significantly reduced the neutrophil concentrations in the distal ends of the skin flaps when compared to untreated animals (P < 0.05). Moreover, allopurinol reduced skin necrosis to 12 +/- 1%. Preconditioning of the skin flap reduced the XO activity to sham control levels. The observations implicate XO activity as source of free radical injury in skin necrosis seen in random skin flaps.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- R Rees
- Department of Surgery, University of Michigan, Ann Arbor 48109
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41
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Yang SX, Hong XF, Li TD. [Comparison of lipoperoxidative damage in plasma and platelet with the ratio of thromboxane A2 and prostaglandin I2 in blood stasis syndrome with coronary heart disease]. Zhongguo Zhong Xi Yi Jie He Za Zhi 1993; 13:661-2, 644. [PMID: 8155941] [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] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In order to study the biochemical and pathophysiological mechanism of the Blood Stasis Syndrome (BSS) or Non-BSS of coronary heart disease (CHD) patients, the activities of SOD, Selenium-glutathione peroxidase, the content of LPO in plasma and platelets and the contents of TXB2 and 6-keto-PGF1 alpha in plasma were determined in 109 BSS and Non-BSS of CHD patients compared with 98 healthy controls. It was discovered that the contents of TXB2, LPO, PL-LPO, and the ratio of TXB2/6-keto-PGF1 alpha were significantly increased in BSS-CHD patients compared with controls and Non-BSS-CHD patients. It was also discovered that the SOD activities and the contents of 6-keto-PGF1 alpha decreased significantly in Non-BSS-CHD patients. The results suggested that the injury of platelets by oxygen free radicals might be one of the primary injury factors in BSS-CHD patients. Our conclusion is that PGI2, SOD belong to the category of Heart-Qi, while TXA2, LPO to the Blood category. Therefore TXB2, 6-keto-PGF1 alpha, SOD, LPO should serve as some of the objective indexes for BSS patients of CHD.
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Affiliation(s)
- S X Yang
- Dept. of Cardiology, General Hospital of PLA, Beijing
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42
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Li TD. [Rethrombosis after coronary thrombolysis]. Zhonghua Nei Ke Za Zhi 1992; 31:246-8. [PMID: 1425006] [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: 12/27/2022]
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43
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Li TD, Gai LY, Wang SR. [Coronary thrombolysis with defibrase]. Zhonghua Nei Ke Za Zhi 1990; 29:88-90, 125-6. [PMID: 2209234] [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] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Clinical use of defibrase (DF), a fibrinolytic agent from venom of Agkistrodon acutus, was investigated in patients with acute myocardial infarction (AMI). Patients with AMI were randomized to tow groups, one receiving conventional therapy and DF, the other a control group having conventional treatment only. The patients in the DF group received intravenous DF 0.05 u or 0.075 u/kg over 1 hour immediately after the attack and 0.025 u/kg over 4 hours on the 5 th and 10 th day. The control patients received conventional therapy only. Of the patients randomized, 21 had coronary angiography and left ventriculography. Recanalization was seen in 10 of the 10 patients treated with DF, while only in 3 of the 11 patients in the control group. LVEF in the DF group was higher than that in the control group (61% vs 50%). However the difference was not significant. In the DF group, two patients developed petechia and blood oozing at the site of intravenous injection and one patient developed gum bleeding; all patients had transient thrombocytopnia, which returned to normal within 5 days. There was no intracranial hemorrhage, gross hematuria or hematemesis. In conclusion, DF possess thrombolytic as well as anticoagulant effects with minor bleeding complication. Early infusion of DF yields high patency rate and shows a trend toward preservation of LV function.
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Affiliation(s)
- T D Li
- Department of Cardiology, PLA General Hospital
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44
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Li TD, Yang WX. [Smooth muscle tumors of the alimentary tract--a review of 397 cases]. Zhonghua Zhong Liu Za Zhi 1986; 8:287-90. [PMID: 3757746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
397 cases of smooth muscle tumor of the alimentary tract were analysed. 385 were collected from the domestic literature in the recent 10 years and 12 are added by the authors. The tumor occurred more frequently in patients 40-60 years old. Diameter of the tumor ranged from 0.5-35 cm. The diameter of leiomyosarcoma was larger than that of leiomyoma on an average. The ratio of benign to malignant incidence was 3.2:1. Exclusive of 204 (51.4%) cases which occurred in the esophagus, the ratio was 1.1:1 in the other 193. In the 12 cases reported by the authors, it was 1:3. In the 193 cases of the GI tract, the lesion occurred in the stomach in 50.8%, in the small intestine in 29.0%, in the colon 1.0% and in the rectum 19.2%. The three most common clinical symptoms of those in the stomach and small intestine were abdominal mass (54.3%), bleeding (49.1%) and abdominal pain (45.7%). These 12 cases reported comprised 0.019% of 62, 088 patients admitted into our hospital, 0.09% of 12,678 tumor inpatients during the same period and 0.61% of 1,983 of malignant tumors in the alimentary tract. The preoperative diagnostic accuracy of this tumor was low, only 7.7% of all the GI neoplasms. On basis of the present data, improving the preoperative diagnostic accuracy is stressed.
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45
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Li TD. [Effect of pineal body extract on cytoxan-induced leucopenia in mice]. Zhonghua Zhong Liu Za Zhi 1985; 7:344-7. [PMID: 4092575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The effect of pig pineal extract on cytoxan-induced leucopenia in mice was studied. Three preparations of pineal body, Songlesu A, B and C, were used. All of them were effective in leucopenia. They delayed the time of the lowest white count, reduced the extent of white cell reduction and elevated and sustained the white count for several days despite the continuation of cytoxan injection. The effect of Songlesu A was most marked. The differences between the white count of group A (Songlesu A plus cytoxan) and the control (cytoxan plus normal saline) are very significant (P less than 0.01) in a period of 8-15 days after giving the drugs. After discontinuation of medication, the recovery of group A was better than that in the control group also very significantly (P less than 0.01). It is evident that Songlesu A is most worthy of further investigation. However, the effect of Songlesu A was no longer marked from the seventeenth day when the white count started to decline. This is most probably due to the severe bone marrow damage by the large dose of cytoxan accumulated or the protracted daily administration. Moreover, Songlesu A may sensitize the bone marrow to cytoxan toxicity or change the rate of recovery after bone marrow damage.
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