Ultra-stable dendrite-free Na and Li metal anodes enabled by tin selenide host material

Lithium/sodium metal anodes are considered promising candidates to realize high-energy-density batteries because of their high theoretical specific capacity and low potential. However, their cycling stability are hindered by uncontrolled dendrites growth. Herein, SnSe nanoparticles are tightly anchored on the fiber of carbon cloth (CC) to construct SnSe@CC host material in order to control Li/Na nucleation behavior and restrain dendrites growth. It is demonstrated that the alloying product of Li15Sn4/Na15Sn4 with strong metal affinity can provide abundant active nucleation sites, and three-dimensional structure of CC host can significantly decrease the local electric current, thereby guiding homogeneous metal deposition without Li and Na dendrites. Meanwhile, the conversion product of Li2Se/Na2Se will uniformly cover on the surface of metal to serve as ultra-stable solid state interface film. As a result, high-capacity Li metal anode (20 mAh·cm-2) and Na metal anode (10 mAh·cm-2) can work steadily with ultra-long lifespans over 5000 and 6000 h with low overpotentials of 7 mV and 141 mV, respectively. Moreover, the assembled Li and Na metal full batteries exhibit superior electrochemical performances, confirming the practicability of metal anode confined in composite host. Such a strategy of conversion-alloying-type materials as hosts opens up a new path for dendrite-free metal anode electrode.

Boosting Manganese Selenide Anode for Superior Sodium-Ion Storage via Triggering α → β Phase Transition

Sodium-ion batteries (SIBs) have been extensively studied owing to the abundance and low-price of Na resources. However, the infeasibility of graphite and silicon electrodes in sodium-ion storage makes it urgent to develop high-performance anode materials. Herein, α-MnSe nanorods derived from δ-MnO2 (δ-α-MnSe) are constructed as anodes for SIBs. It is verified that α-MnSe will be transferred into β-MnSe after the initial Na-ion insertion/extraction, and δ-α-MnSe undergoes typical conversion mechanism using a Mn-ion for charge compensation in the subsequent charge-discharge process. First-principles calculations support that Na-ion migration in defect-free α-MnSe can drive the lattice distortion to phase transition (alpha → beta) in thermodynamics and dynamics. The formed β-MnSe with robust lattice structure and small Na-ion diffusion barrier boosts great structure stability and electrochemical kinetics. Hence, the δ-α-MnSe electrode contributes excellent rate capability and superior cyclic stability with long lifespan over 1000 cycles and low decay rate of 0.0267% per cycle. Na-ion full batteries with a high energy density of 281.2 Wh·kg-1 and outstanding cyclability demonstrate the applicability of δ-α-MnSe anode.

Bismuth Telluride Nanoplates Hierarchically Confined by Graphene and N-Doped C as Conversion-Alloying Anode Materials for Potassium-Ion Batteries

Potassium-ion batteries (PIBs) have broad application prospects in the field of electric energy storage systems because of its abundant K reserves, and similar "rocking chair" operating principle as lithium-ion batteries (LIBs). Aiming to the large volume expansion and sluggish dynamic behavior of anode materials for storing large sized K-ion, bismuth telluride (Bi2 Te3 ) nanoplates hierarchically encapsulated by reduced graphene oxide (rGO), and nitrogen-doped carbon (NC) are constructed as anodes for PIBs. The resultant Bi2 Te3 @rGO@NC architecture features robust chemical bond of Bi─O─C, tightly physicochemical confinement effect, typical conductor property, and enhanced K-ion adsorption ability, thereby producing superior electrochemical kinetics and outstanding morphological and structural stability. It is visually elucidated via high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) that conversion-alloying dual-mechanism plays a significant role in K-ion storage, allowing 12 K-ion transport per formular unit employing Bi as redox site. Thus, the high first reversible specific capacity of 322.70 mAh g-1 at 50 mA g-1 , great rate capability and cyclic stability can be achieved for Bi2 Te3 @rGO@NC. This work lays the foundation for an in-depth understanding of conversion-alloying mechanism in potassium-ion storage.

Advanced Anode Materials for Rechargeable Sodium-Ion Batteries

Rechargeable sodium-ion batteries (SIBs) have been considered as promising energy storage devices owing to the similar "rocking chair" working mechanism as lithium-ion batteries and abundant and low-cost sodium resource. However, the large ionic radius of the Na-ion (1.07 Å) brings a key scientific challenge, restricting the development of electrode materials for SIBs, and the infeasibility of graphite and silicon in reversible Na-ion storage further promotes the investigation of advanced anode materials. Currently, the key issues facing anode materials include sluggish electrochemical kinetics and a large volume expansion. Despite these challenges, substantial conceptual and experimental progress has been made in the past. Herein, we present a brief review of the recent development of intercalation, conversion, alloying, conversion-alloying, and organic anode materials for SIBs. Starting from the historical research progress of anode electrodes, the detailed Na-ion storage mechanism is analyzed. Various optimization strategies to improve the electrochemical properties of anodes are summarized, including phase state adjustment, defect introduction, molecular engineering, nanostructure design, composite construction, heterostructure synthesis, and heteroatom doping. Furthermore, the associated merits and drawbacks of each class of material are outlined, and the challenges and possible future directions for high-performance anode materials are discussed.

Boosting cobalt ditelluride quantum-rods anode materials for excellent potassium-ion storage via hierarchical physicochemical encapsulation

The exploration of anode materials that can store large-sized K-ion to solve the poor kinetics and large volume expansion issues has become the key scientific bottlenecks hindering the development of potassium-ion batteries (PIBs). Herein, ultrafine CoTe₂ quantum rods physiochemically encapsulated by graphene and nitrogen-doped carbon (CoTe₂@rGO@NC) are regarded as anode electrodes for PIBs. Dual physicochemical confinement and quantum size effect not only enhance electrochemical kinetics but also restrain large lattice stress during repeated K-ion insertion/extraction process. Superior electronic conductivity, K-ion adsorption, and diffusion ability can be acquired for CoTe₂@rGO@NC, confirmed through first-principles calculations and kinetics study. K-ion insertion/extraction proceeds via a typical conversion mechanism relying on Co as the redox site, where the robust chemical bond of COCo plays an important role in maintaining the electrode stability. Accordingly, CoTe₂@rGO@NC contributes a high initial capacity of 237.6 mAh·g^-1 at 200 mA·g^-1, a long lifetime over 500 cycles with low-capacity decay of 0.10% per cycle. This research will lay the materials science foundation for the construction of quantum-rod electrodes.

Cr(OH)3nanosheets@ZIF67 electrocatalysts prepared by electrodeposition method for efficient oxygen evolution reaction

In this paper, a Cr(OH)₃NSs@ZIF67 (NSs = nanosheets) electrocatalyst is prepared on foam Ni via a simple and rapid electrochemical deposition method. Excellent electrocatalytic activity of Cr(OH)₃NSs@ZIF67 is demonstrated. It can use the overpotential of 281 mV and 390 mV respectively to drive 10 mA cm^-2and 50 mA cm^-2. It is observed that the Cr(OH)₃NSs@ZIF67 electrode has the highest initial current density at 1.57 V compared with the other two monomer electrodes and shows excellent stability at the end of 60 000 s. It has the largest electrochemical activity specific surface and lowest charge-transfer resistance, and M-O bonds (M = Co, Cr) and shifting of binding energy peaks at the interface lead to more active sites and more efficient electron transfer for oxygen evolution reaction. This work highlights the construction of highly efficient composite electrocatalysts composted of low-dimensional non-precious transition metal compounds and metalorganic frameworks, promoting the development of low-cost non-noble metal composites in energy chemistry.

Nitrogen and Oxygen Co-Doped Porous Hard Carbon Nanospheres with Core-Shell Architecture as Anode Materials for Superior Potassium-Ion Storage

The investigation of carbonaceous-based anode materials will promote the fast application of low-cost potassium-ion batteries (PIBs). Here a nitrogen and oxygen co-doped yolk-shell carbon sphere (NO-YS-CS) is constructed as anode material for K-ion storage. The novel architecture, featuring with developed porous structure and high surface specific area, is beneficial to achieving excellent electrochemical kinetics behavior and great electrode stability from buffering the large volume expansion. Furthermore, the N/O heteroatoms co-doping can not only boost the adsorption and intercalation ability of K-ion but also increase the electron transfer capability. It is also demonstrated by experimental results and DFT calculations that K-ion insertion/extraction proceeds through both intercalation and surface capacitive adsorption mechanisms. As expected, the NO-YS-CS electrodes show high initial charge capacity of 473.7 mAh g^-1 at 20 mA g^-1 , ultralong cycling life over 2500 cycles with the retention of 85.8% at 500 mA g^-1 , and superior rate performance (183.3 mAh g^-1 at 1.0 A g^-1 ). The K-ion full cell, with a high energy density of 271.4 Wh kg^-1 and an excellent cyclic stability over 500 cycles, is successfully fabricated with K₂ Fe[Fe(CN)₆ ] cathode. This work will provide new insight on the synthesis and mechanism understanding of high-performance hard carbon anode for PIBs.

Sb2S3-based conversion-alloying dual mechanism anode for potassium-ion batteries

The large volume expansion and sluggish dynamic behavior are the key bottleneck to suppress the development of conversion-alloying dual mechanism anode for potassium-ion batteries (PIBs). Herein, Sb2S3 nanorods encapsulated by reduced graphene oxide and nitrogen-doped carbon (Sb2S3@rGO@NC) are constructed as anodes for PIBs. The synergistic effect of dual physical protection and robust C-Sb chemical bonding boosts superior electrochemical kinetics and great electrode stability. Thus, Sb2S3@rGO@NC exhibits a high initial charge capacity of 505.6 mAh·g-1 at 50 mA·g-1 and a great cycle stability with the lifetime over 200 cycles at 200 mA·g-1. Ex situ XRD, XPS, and TEM characterizations confirm that the electrode undergoes a multielectron transfer process (Sb2S3↔ Sb + K2S ↔ KSb + K3Sb), where K-ion insert into/extract from the material via dual mechanisms of conversion and alloying. This work sheds a light on the construction of high-performance anode materials and the understanding of K-ion storage mechanism.

Dielectric travelling wave antennas for directional light emission

We present a combined experimental and numerical study of the far-field emission properties of optical travelling wave antennas made from low-loss dielectric materials. The antennas considered here are composed of two simple building blocks, a director and a reflector, deposited on a glass substrate. Colloidal quantum dots placed in the feed gap between the two elements serve as internal light source. The emission profile of the antenna is mainly formed by the director while the reflector suppresses backward emission. Systematic studies of the director dimensions as well as variation of antenna material show that the effective refractive index of the director primarily governs the far-field emission pattern. Below cut off, i.e., if the director's effective refractive index is smaller than the refractive index of the substrate, the main lobe results from leaky wave emission along the director. In contrast, if the director supports a guided mode, the emission predominately originates from the end facet of the director.

Three-phase composites of NiFe2O4/Ni@C nanoparticles derived from metal-organic frameworks as electrocatalysts for the oxygen evolution reaction

Composite electrocatalysts of carbon and metals or metal compounds with homogeneous active sites can be obtained through the carbonization of metal organic framework (MOF) materials under inert atmosphere. In this work, a three-phase composite electrocatalysts NiFe₂O₄/Ni@C were prepared via pyrolysis from self-assembled MOF nanosheets aggregates. The excellent electrocatalytic activity of the obtained electrocatalysts with various Ni:Fe ratios is demonstrated. Especially, the NiFe₂O₄/Ni@C sample with the mole ratio of Ni:Fe = 1:1 can use the overpotential (η) of 330 and 423 mV to drive 10 and 50 mA cm^-2 respectively. After 80 000 s/22 h, the current density could retained 90% of the initial current density. The excellent activity and stability of the electrocatalysts are attributed to nickel and iron ions with uniform dispersion at atomic level in the NiFe₂O₄ phase and the synergistic effect of nickel and NiFe₂O₄ nanoparticles with amorphous carbon atoms or nanoparticles around.

[Analysis of clinicopathologic characteristics of gastric cancer patients undergoing gastrectomy based on a single-center gastric cancer database with above 10 000 cases]

Objective: The storage of medical data has been digitized in China, but a unified and structured model has not yet been established. The standardized collection, analysis and sorting of tumor clinical data is the foundation of improving the standard of tumor diagnosis and treatment. Therefore, establishing a database platform of gastric cancer (GC) is an urgent need to integrate data resources and improve the level of diagnosis and treatment. The population economics indexes of GC patients in the last 20 years are analyzed in a single-center GC database. The medical records were structured by natural language processing technology. Authors aim to investigate the clinical pathological characteristics, staging and survival of the GC patients with gastrectomy. Method: A retrospective cohort study was carried out. Clinicopatological data of patients receiving surgical treatment from 2000 to 2019 were retrospectively collected. According to the gastric cancer TNM staging guidelines from the Union for International Cancer Control and the American Joint Committee on Cancer (UICC/AJCC) 8th edition, the structured gastric cancer clinicopathological data were re-evaluated and interpreted. The Kaplan-Meier method and the log-rank test were used to compare survival rate among different groups of patients with complete follow-up data of 2010-2016. Results: Clinicopathological data of 13 492 GC patients were enrolled. The ratio of men to women in the whole group was 3.25:1.00, including 10 320 men with average onset age of 59.68 years, which was basically stable in recent 20 years, and 3172 women with average onset age of 55.93 years, which presented a trend of average increasement of 0.17 year per year. The average hospitalization duration for GC patients showed a decreasing trend year by year, which was 13.87 days in 2019. Average hospitalization cost for GC patients was increasing year by year, with a peak of 83 600 CNY in 2017 and 75 400 CNY in 2019. By natural language identification and exclusion criteria screening, a total of 7218 GC patients obtained structured clinicopathological information. Analysis on clinicopathological characteristics of 3626 GC patients in the last 5 years showed that the average diameter of tumor was (4.44±2.61) cm; the average number of harvested lymph node was 24.30±13.29; the proportion of surgical methods were as following: open surgery in 1398 cases (38.55%), laparoscopic surgery in 1856 cases (51.19%) and robotic surgery in 372 cases (10.26%). The postoperative pathological stage was as following: IA in 658 cases (18.15%), IB in 318 cases (8.77%), IIA in 559 cases (15.42%), IIB in 543 (14.98%), III A in 632 (17.43%), III B in 612 cases (16.88%), III C in 276 cases (7.61%), and IV in 28 cases (0.77%). Complete follow-up data of 3431 patients from 2010 to 2016 were presented. The 1-, 3- and 5-year survival rates were 82%, 69% and 60%, respectively for the whole group. The 1-, 3- and 5-year survival rates for patients undergoing laparoscopic surgery were 83%, 70% and 64%, respectively, and for those undergoing open surgery were 81%, 67% and 56%, respectively, and the difference between the two groups was not statistically significant (P=0.109). The 5-year survival rate of GC patients with different AJCC stages was as following: 88% in IA, 77% in IB, 70% in II A, 62% in II B, 44% in III A, 32% in III B, 22% in III C, and 17% in IV. Conclusion: This study provides basic data for the establishment of comprehensive diagnosis and treatment model of multicenter, shedding light on the improvement of comprehensive treatment of GC in China.

Performance of the BL03U beamline at SSRF

The vacuum ultraviolet beamline BL03U with a photon energy range from 7 eV upwards has been constructed at the 3.5 GeV Shanghai Synchrotron Radiation Facility. Equipped with an APPLE-Knot undulator, this beamline is dedicated to angle-resolved photoemission spectroscopy. An energy-resolving power of higher than 4.6 × 10⁴ has been achieved in the photon energy range 21.6-48 eV, which is almost the same as the theoretical estimation.

Vertical distribution of microbial communities and their response to metal(loid)s along the vadose zone-aquifer sediments

AIMS

This study attempted to demonstrate the vertical shift in bacterial, archaeal and fungal communities along the vadose zone-aquifer sediments and their respective responses to environmental factors.

METHODS AND RESULTS

We collected samples from the vadose zone and three aquifer sediments along a 42·5 m bore of a typical agricultural land. The results showed that the bacterial community shifted greatly with depth. The classes of Actinobacteria (19·5%) and NC10 (11·0%) were abundant in the vadose zone while Alphaproteobacteria (22·3%) and Gammaproteobacteria (20·1%) were enriched in the aquifer. Archaeal and fungal communities were relatively more homogeneous with no significant trend as a function of depth. Process analyses further indicated that selection dominated in the bacterial community, whereas stochastic processes governed archaeal and fungal communities. Moreover environment-bacteria interaction analysis showed that metal(loid)s, especially alkali metal, had a closer correlation with the bacterial community than physicochemical variables.

CONCLUSIONS

Depth strongly affected bacterial rather than archaeal and fungal communities. Metal(loid)s prevailed over physicochemical variables in shaping the bacterial community in the vadose zone-aquifer continuum.

SIGNIFICANCE AND IMPACT OF THE STUDY

Our study provides a new perspective on the structure of microbial communities from the vadose zone to the deep aquifers.

Delivering Focused Ultrasound to Intervertebral Discs Using Time-Reversal

Chronic low back pain causes more disability worldwide than any other condition and is thought to arise in part through loss of biomechanical function of degenerate intervertebral discs (IVDs). Current treatments can involve replacing part or all of the degenerate IVDs by invasive surgery. Our vision is to develop a minimally invasive approach in which high intensity focused ultrasound (HIFU) is used to mechanically fractionate degenerate tissue in an IVD; a fine needle is then used to first remove the fractionated tissue and then inject a biomaterial able to restore normal physiologic function. The goal of this manuscript is to demonstrate the feasibility of trans-spinal HIFU delivery using simulations of 3-D ultrasound propagation in models derived from patient computed tomography (CT) scans. The CT data were segmented into bone, fat and other soft tissue for three patients. Ultrasound arrays were placed around the waist of each patient model, and time-reversal was used to determine the source signals necessary to create a focus in the center of the disc. The simulations showed that for 0.5 MHz ultrasound, a focus could be created in most of the lumbar IVDs, with the pressure focal gain ranging from 3.2-13.7. In conclusion, it is shown that with patient-specific planning, focusing ultrasound into an IVD is possible in the majority of patients despite the complex acoustic path introduced by the bony structures of the spine.

Development of a rapid immunochromatographic assay for detection of antibodies against porcine epidemic diarrhea virus

An immunochromatographic test strip was developed for the detection of antibodies against porcine epidemic diarrhea virus (PEDV) in porcine serum. In this test, the recombinant nucleocapsid protein of PEDV was expressed in soluble form and purified by using Ni-NTA resin and gel filtration chromatography. The purified recombinant N protein conjugated with colloidal gold was dispensed on a conjugate pad as the detector. Staphylococcal protein A and rabbit anti-N protein IgG were blotted on a nitrocellulose membrane for the test and control lines, respectively. The immunochromatographic test strip specifically detected PEDV antibodies within 10 min and had higher sensitivity (96.0%) and specificity (90.8%) than those of commercial enzyme-linked immunosorbent assay (ELISA) kits. Our newly developed strip has great potential for the early diagnosis of PEDV infection.

Logistic-function-based nonlinear companding transform for asymmetrical hybrid optical orthogonal frequency division multiplexing visible light communications systems

In this paper, a logistic-function-based nonlinear companding transform (LNCT) is proposed to reduce the peak-to-average power ratio of asymmetrical hybrid optical orthogonal frequency division multiplexing (AHO-OFDM) signals in visible light communications (VLC). First, the positive and negative amplitudes of the bipolar AHO-OFDM signal are divided into two groups as the positive and nonnegative groups. Then, a peak detection is employed frame-by-frame to locate the group where the maximum peak occurs. Finally, the piecewise companding transform consisting of the nonlinear logistic function and a linear function is performed on the amplitude groups with and without the maximum peak, respectively. The simulation results show that the proposed LNCT scheme outperforms the classical linear nonsymmetrical transform method in terms of the complementary cumulative distribution function with a competing bit error rate performance, thus demonstrating its application potential in AHO-OFDM-based VLC systems.

Analysis of evolution and genetic diversity of sweetpotato and its related different polyploidy wild species I. trifida using RAD-seq

BACKGROUND

Sweetpotato (Ipomoea batatas (L.) Lam.) is one of the most important crops from the family of Convolvulaceae. It is widely reported that cultivated sweetpotato was originated from Ipomoea trifida. However, diploid, tetraploid and hexaploid I. trifida were found in nature. The relationship, between them, and among them and sweetpotato, is remaining unclear.

RESULTS

In the present study, we detected the genome diversity and relationship of sweetpotato and different polyploidy types I. trifida using Restriction-site Associated DNA Sequencing (RAD-seq). A total of 38,605 RAD-tags containing 832,204 SNPs had been identified. These tags were annotated using five public databases, about 11,519 tags were aligned to functional genes in various pathways. Based on SNP genotype, phylogenetic relation analysis results confirmed that cultivated sweetpotato has a closer relationship with I. trifida 6× than with I. trifida 4X and I. trifida 2×. Besides, 5042 SSRs were detected in I. trifida 6×, and 3202 pairs of high-quality SSR primers were developed. A total of 68 primers were randomly selected and synthesized, of which 61 were successfully amplified.

CONCLUSION

These results provided new evidence that cultivated sweetpotato originated from I. trifida 6×, and that I. trifida 6× evolved from I. trifida 4X and I. trifida 2×. Therefore, using I. trifida 6× as the model plant of sweetpotato research should be more practical than using I. trifida 2× in the future. Meanwhile, sequence information and markers from the present study will be helpful for sweetpotato and I. trifida studies in the future.

Correlation between expression of LRP16, Ki67 and EGFR and breast cancer clinical pathologic factors and prognosis

OBJECTIVE

To investigate the expression of leukemia-related protein 16 (LRP16), proliferating cell nuclear antigen K-67 (Ki67) and epidermal growth factor receptor-1 (EGFR-1) in breast cancer tissue and to explore the correlation between the expression of those proteins and breast cancer clinical pathologic factors and prognosis.

PATIENTS AND METHODS

The expressions of LRP16, Ki67 and EGFR in breast cancer tissues of 86 cases were detected by the immunohistochemical method and the correlations between the expression of LRP16, Ki67 and EGFR and clinical pathologic factors and prognosis were investigated.

RESULTS

Positive expression rates of LRP16, Ki67 and EGFR in breast cancer tissue were 52.3%, 70.9% and 16.3%, respectively. There was no statistical difference in the expression of RP16, Ki67 and EGFR between different age groups (p>0.05). The expression of LRP16 was correlated with clinical stage, histological grade, tumor size and lymphatic metastasis (p<0.05); the expression of Ki67 was correlated with clinical stage, histological grade, tumor size and lymphatic metastasis (p<0.05); the expression of EGFR was correlated with histological grade (p<0.05). Comparison of postoperative local recurrence and metastasis time between LRP 16 positive group and negative group showed statistically significant difference (p<0.05); comparison of postoperative local recurrence and metastasis time between Ki67 positive group and negative group also showed statistically significant difference (p<0.05); comparison of postoperative local recurrence and metastasis time between EGFR positive group and negative group showed no statistically significant difference (p<0.05).

CONCLUSIONS

Detection of expression levels of LPR16, Ki67 and EGFR in breast cancer tissue improves the understanding of biological behaviors of breast cancer, which in turn provide clinical guidance in diagnosis, treatment and prognosis assessment.

TGF-β1 promotes human hepatic carcinoma HepG2 cells invasion by upregulating autophagy

OBJECTIVE

To study the role of TGF-β1 in autophagy and invasion ability of human hepatic carcinoma HepG2 cells.

MATERIALS AND METHODS

Cultured HepG2 cells were treated with different concentrations of TGF-β1 for 24 h. The protein expression levels of autophagy relative marker LC3 and Beclin1 were detected by Western blot. The effect of TGF-β1 on invasion ability of HepG2 cells was detected with transwell method.

RESULTS

The results demonstrated that TGF-β1 was able to activate autophagy of HepG2 cells in a dose-dependent manner. Autophagy inhibitor 3-methyladenine (3-MA) could reverse TGF-β1 induced autophagy process. Also, TGF-β1 significantly promotes the invasion ability of HepG2 cells; however, this process could effectively reverse by autophagy inhibitor 3-MA.

CONCLUSIONS

TGF-β1 enhances HepG2 cells invasion by upregulating autophagy.

GP5 Protein-based ELISA for the Detection of PRRSV Antibodies

Porcine reproductive and respiratory syndrome virus (PRRSV) is an important swine pathogen, causing huge economic losses each year worldwide. Immunization with vaccines containing the glycoprotein 5 (GP5) of PRRSV is the main measure to induce neutralizing antibodies and control the disease. Here, we developed a GP5 protein-based ELISA for detecting antibodies against PRRSV. The overall yield of purified GP5 in E. coli flask culture was more than 45 mg/L cell culture. Western blot and IFA indicated that the GP5 protein was highly immunogenic. After optimization and validation with IDEXX PRRS using 566 clinical sera, the DSN, DSP, and accuracy of GP5-ELISA were 81.39%, 75.96%, and 80.39%, respectively. Besides, GP5-ELISA is highly specific, showing no cross-reactions with sera against other important swine pathogens. Hence, GP5 is a good diagnostic antigen and the GP5 protein-based ELISA has the potential to be used in the field.

Unraveling Photoinduced Spin Dynamics in the Topological Insulator Bi(2)Se(3)

We report on a time-resolved ultrafast optical spectroscopy study of the topological insulator Bi_{2}Se_{3}. We unravel that a net spin polarization cannot only be generated using circularly polarized light via interband transitions between topological surface states (SSs), but also via transitions between SSs and bulk states. Our experiment demonstrates that tuning photon energy or temperature can essentially allow for photoexcitation of spin-polarized electrons to unoccupied topological SSs with two distinct spin relaxation times (∼25 and ∼300  fs), depending on the coupling between SSs and bulk states. The intrinsic mechanism leading to such distinctive spin dynamics is the scattering in SSs and bulk states which is dominated by E_{g}^{2} and A_{1g}^{1} phonon modes, respectively. These findings are suggestive of novel ways to manipulate the photoinduced coherent spins in topological insulators.

165 THE EFFECT OF shRNA TARGETING CLUSTER OF DIFFERENTIATION ANTIGEN 14 ON GENE EXPRESSION OF TNF-α, TLR4, AND IL-6 IN LIPOPOLYSACCHARIDE-INDUCED BUFFALO PERIPHERAL BLOOD MONOCYTE/MACROPHAGE

Cluster of differentiation antigen 14 (CD14) plays a crucial role in the inflammatory response to lipopolysaccharide (LPS), which interacts with TLR4 and MD-2 to enable cell activation, leading to inflammation. Several studies have proved that upstream inhibition of bacterial LPS/toll-like receptor 4 (TLR4)/CD14-mediated inflammation pathway is an effective therapeutic approach for attenuating damaging immune activation. In this study, to explore the effect of CD14 down-regulation on TLR4 signal conductive-related genes expression after stimulation by LPS, five CD14 shRNA (319/421/755/970/1041) sequences and a negative control sequence (NC-1864) were synthesised and used to construct lentiviral recombinant plasmid pSicoR-GFP-shRNA. Lentiviral recombinant plasmids of pSicoR-GFP-shRNA and fusion expression vector of pDsRed-N1-buffalo CD14 were co-transfected into HEK293 using liposome. At 72 h after transfection, the expression of exogenous buffalo CD14 mRNA was reduced at different level for all shRNA plasmids, in which shRNA-1041 had the highest interfering efficiency by RT-qPCR and fluorescence-activated cell sorting analysis. Then, buffalo peripheral blood monocyte/macrophage was purified and infected by the CD14 shRNA lentivirus. After 7 days of infection, the cells were stimulated by 1 µg mL–1 LPS for 3 h, then the mRNA expression level of CD14, TLR4, IL-6, and TNF-α transcripts in the cells were detected by the RT-qPCR method. After stimulation by LPS, the expression of endogenous CD14 was significantly reduced by CD14 shRNA-1041, the mRNA expression level of TLR4, IL-6, and TNF-α genes was also significantly down-regulated in comparison with control group (P ≤ 0.01). In conclusion, the selected CD14 shRNA-1041 cannot only inhibit the expression of endogenous CD14 mRNA in buffalo peripheral blood monocyte/macrophage, but also downregulate the mRNA expression of CD14, TLR4, IL-6, and TNF-α. The above results demonstrate that knockdown of endogenous CD14 has obvious coordination effects on the signal conductive function of TLR4 after stimulating by LPS, and shRNA technology will provide a new way to prevent endotoxin-related diseases in livestock. This work was supported by the National Transgenic Project (2009ZX08007-009B), Guangxi natural science funding (2012GXNSFCB053002), and funding of State Key Laboratory of Subtropical Bioresource Conservation and Utilisation (KSL-CUSAb-2012-02).

A preliminary design of a knot undulator

The magnetic field configuration of the previously proposed knot undulator [Qiao et al. (2009). Rev. Sci. Instrum. 80, 085108] is realised in the design of a hybridized elliptically polarized undulator, which is presented. Although the details of the field distribution are not the same as those in the theoretical proposal, it is demonstrated that the practical knot undulator could work perfectly. In order to understand the minor discrepancies of the two, mathematical formulae of the synchrotron radiation are derived based on the Fourier transform of the magnetic field. From the results of calculations by simulation program, the discrepancies could be well interpreted by the corresponding formulae. The results show the importance of optimization of the end sections of the knot undulator to suppress the on-axis heat load. Furthermore, a study of the impact of the undulator on beam dynamics of the storage ring was conducted using the Shanghai Synchrotron Radiation Facility as an example and the results show that the knot undulator has little effect on the beam.

Spin-orbit splitting in graphene on metallic substrates

Substrate-induced spin-orbit splitting in graphene on Ni, Au and Ag(111) is examined on the basis of density-functional theory. The Rashba splitting of π bands along the ΓM direction of the graphene surface Brillouin zone in graphene on Ni(111) is found to be very small (a few millielectronvolts), consistent with the experimental report of Rader et al. Instead, very strong Rashba splitting (near 100 meV) can be obtained for graphene with a certain stretch distortion on a Au substrate. It can be ascribed to the effective match in energy between the C 2p and Au 5d bands, obtained from the analysis of densities of states. The net charge transfer between the graphene and the substrates just affects the spin-orbit effect indirectly. The small spin-orbit splitting induced by the Ag substrates indicates that heavy metals do not always produce large SO splitting. Our findings provide important insights that are useful for understanding the metal-induced Rashba effect in graphene.

Note: Leaf undulator to realize polarization control with low on-axis heat load

Here, a new operational mode of an electromagnetic elliptical undulator, called leaf undulator, is proposed and studied. It can provide linearly polarized radiation at an arbitrary polarization direction depending on the magnitude and polarity of the horizontal and vertical magnetic fields. The polarization direction becomes 45 degrees when the horizontal and vertical magnetic fields are equal in strength. It is also able to switch the operational mode to purely circular or elliptical one. To lower the on-axis power density generated by undulators operating in linear mode, different designs have been presented in the past. Leaf undulator can suppress the on-axis power density by an order of magnitude compared to the so-called Knot and Figure-8 undulators, while maintaining comparable photon flux of the fundamental harmonic. Furthermore, it is possible to reach a lower fundamental energy under linear mode than by any other design using comparable magnetic field strengths.

Knot undulator to generate linearly polarized photons with low on-axis power density

Heat load on beamline optics is a serious obstacle for devices designed to generate pure linearly polarized photons in third generation synchrotron radiation facilities. For permanent magnet undulators, this problem can be overcome by implementing a figure-eight design configuration. As yet there has been no good method to tackle this problem for electromagnetic elliptical undulators. Here, a novel design and operational mode is suggested, which can generate pure linearly polarized photons with very low on-axis heat load. Additionally, the minimum photon energy capability of linearly polarized photons can be significantly extended by this method.

Detection and localization of naturally transmitted avian leukosis subgroup J virus in egg-type chickens by in situ PCR hybridization

Avian leukosis virus (ALV) subgroup J (ALV-J) is an exogenous ALV and causes myeloid leukosis in meat-type chickens. We have previously reported the isolation and identification of ALV-J in commercial layer flocks from 12 farms in northern China. In this report, we further characterized this virus by in situ polymerase chain reaction (PCR) hybridization in various affected organs of chickens from six of the 12 farms. A routine method for hybridization of nucleic acid uses radioactive probe, such as a P32-labelled probe. We found that the non-radioactive digoxigenin (DIG) probe is sensitive enough to detect the nucleic acid of virus in chicken tissues. We used a pair of published primers (H5/H7) specific to the gp85 envelope gene and 3' region of pol gene of prototype ALV-J strain HPRS-103. The total RNA extracted from tumour, bone marrow, oviduct, liver and spleen of the diseased chickens from six commercial flocks, and cDNA was successfully amplified. Using the primers and cDNA, we obtained an ALV-J-specific cDNA probe of 545 bp in length by PCR. In situ PCR with H5/H7 primers was carried out in the paraffin sections from tissues of the diseased chickens, followed by in situ hybridization using the DIG-labelled cDNA probe. Positive hybridization signals were detected in the cytoplasm of paraffin sections of tumours and other organ tissues. The intensity of the signals was documented using an image analysis system measuring integral optical density (IOD). The IOD values for tissue sections treated by in situ PCR hybridization are significantly higher than that by in situ hybridization alone (P < 0.01). These data taken together suggest that in situ PCR hybridization is a more sensitive technique for detection of ALV-J in tissue sections.

High-energy scale revival and giant kink in the dispersion of a cuprate superconductor

In the present photoemission study of a cuprate superconductor Bi1.74Pb0.38Sr1.88CuO6+delta, we discovered a large scale dispersion of the lowest band, which unexpectedly follows the band structure calculation very well. Similar behavior observed in blue bronze and the Mott insulator Ca2CuO2Cl2 suggests that the origin of hopping-dominated dispersion in an overdoped cuprate might be quite complicated. A giant kink in the dispersion is observed, and the complete self-energy containing all interaction information is extracted for a doped cuprate. These results recovered significant missing pieces in our current understanding of the electronic structure of cuprates.

Calcidiol and prostate cancer

Epidemiological studies suggest that serum calcidiol (25(OH)-Vitamin D3) seems to be associated with several cancers including prostate cancer. We have made several experimental studies in order to clarify the mechanism(s) involved in the association. Calcidiol has been regarded as an inactive prohormone for calcitriol, which possesses the highest biological activity of the Vitamin D metabolites, when it is evaluated on the basis of bioactivity/nmol. However, we found recently that at the physiological concentration calcidiol (100-200 nM) is an active hormone, whereas calcitriol (1alpha,25(OH)2-Vitamin D3) (100 pM) is inactive in human primary prostate stromal cells. Calcidiol is able to inhibit cell growth and to induce or inhibit several genes including 1alpha-hydroxylase and 24-hydroxylase genes. This suggests that calcidiol might be an independent endocrine system involved in the control of cell differentiation and proliferation, whereas calcitriol might be mainly involved in the regulation of calcium and phosphorous balance. Several mechanisms may mediate the action of Vitamin D in the prostate. This is a review of some recent studies on the role of (1) Vitamin D metabolism, (2) growth factors and (3) fatty acid metabolism.

The role of Vitamin D3 metabolism in prostate cancer

Vitamin D deficiency increases risk of prostate cancer. According to our recent results, the key Vitamin D hormone involved in the regulation of cell proliferation in prostate is 25(OH) Vitamin D3. It is mainly acting directly through the Vitamin D receptor (VDR), but partially also through its 1alpha-hydroxylation in the prostate. A deficiency of 25(OH) Vitamin D is common especially during the winter season in the Northern and Southern latitudes due to an insufficient sun exposure, but Vitamin D deficient diet may partially contribute to it. A lack of Vitamin D action may also be due to an altered metabolism or Vitamin D resistance. Vitamin D resistance might be brought up by several mechanisms: Firstly, an increased 24-hydroxylation may increase the inactivation of hormonal Vitamin D metabolites resulting in a Vitamin D resistance. This is obvious in the cancers in which an oncogenic amplification of 24-hydroxykase gene takes place, although an amplification of this gene in prostate cancer has not yet been described. During the aging, the activity of 24-hydroxylase increases, whereas 1alpha-hydroxylation decreases. Furthermore, it is possible that a high serum concentration of 25(OH)D3 could induce 24-hydroxylase expression in prostate. Secondly, Vitamin D receptor gene polymorphism or defects may result in a partial or complete Vitamin D resistance. Thirdly, an overexpression or hyperphosphorylation of retinoblastoma protein may result in an inefficient mitotic control by Vitamin D. Fourthly, endogenous steroids (reviewed by [D.M. Peehl, D. Feldman, Interaction of nuclear receptor ligands with the Vitamin D signaling pathway in prostate cancer, J. Steroid Biochem. Mol. Biol. (2004)]) and phytoestrogens may modulate the expression of Vitamin D metabolizing enzymes. In summary, the local metabolism of hormonal Vitamin D seems to play an important role in the development and progression of prostate cancer.

Photocatalytic oxidation technology for humic acid removal using a nano-structured TiO2/Fe2O3 catalyst

A novel TiO2 coated haematite photocatalyst was prepared and used for removal of colored humic acids from wastewater in an UV bubble photocatalytic reactor. XRD analysis confirmed that nano-size anatase crystals of TiO2 were formed after calcination at 480 degrees C. SEM results revealed that nano-size particles of TiO2 were uniformly coated on the surface of Fe2O3 to form a bulk of nano-structured photocatalyst Fe2O3/TiO2. The porous catalyst had a BET surface area of 168 m2/g. Both the color and total organic carbon (TOC) conversion versus the residence time were measured at various conditions. The effects of pH value, catalyst loaded, initial humic acid concentration and reaction temperature on conversion were monitored. The experimental results proved that the photocatalytic oxidation process was not temperature sensitive and the optimum catalyst loading was found to be 0.4 g/l. Degradation and decolorization of humic acids have higher efficiency in acidic medium and at low initial humic acid concentration. The new catalyst was effective in removing TOC at 61.58% and color400 at 93.25% at 180 minutes illumination time and for 20 mg/l neutral humic acid aqueous solution. The kinetic analysis showed thatthe rate of photocatalytic degradation of humic acids obeyed the first order reaction kinetics.

Senescence and cytoskeleton: overproduction of vimentin induces senescent-like morphology in human fibroblasts

One characteristic feature of senescent fibroblasts is flat, enlarged, and heterogeneous cell shapes. The present study was aimed to understand the structural basis of the senescent cell morphology. SDS-gel electrophoresis as well as western blotting demonstrated that there occurred a prominent protein band about 57 kDa in the senescent cells as compared with normal young or immortalized cells growing rapidly, and the protein was identified with a cytoskeletal protein, vimentin. In fact, senescent fibroblasts contained approximately threefold more vimentin protein, and fourfold more vimentin mRNA than young embryonic fibroblasts. In the senescent cells, vimentin cytoskeleton occurred as densely bundled filaments in parallel with the long axis of cell bodies, whereas in young or actively growing cells it showed short and thin vimentin filaments or fur-like irregular networks. It was further demonstrated that senescent cell shapes could be induced when a vimentin expression construct was transfected in young fibroblasts. These results suggest that senescent fibroblasts overproduce vimentin protein, and the overproduced vimentin filaments bring about the senescent cell morphology.

A randomized trial confirming the efficacy of reduced dose recombinant tissue plasminogen activator in a Chinese myocardial infarction population and demonstrating superiority to usual dose urokinase: the TUCC trial

BACKGROUND

Reports from Japan suggest effective myocardial infarction (MI) treatment in Asian patients with much lower doses of tissue plasminogen activators (tPA) than used in European and American regimens. Because increasing doses of fibrinolytics lead to increased bleeding complications, identification of patients who respond to reduced doses is of importance. We conducted a trial in the People's Republic of China in which reduced-dose recombinant tPA was compared with the standard local therapy, urokinase.

METHODS

Four hundred patients with acute MI within 12 hours of symptom onset were to be randomized to an 8-mg bolus of recombinant tPA followed by a 42-mg 90-minute infusion or 1.5 million units of urokinase as a 30-minute infusion. Patients received aspirin and heparin and underwent angiography to determine infarct artery patency 90 minutes after the start of therapy.

RESULTS

The Data and Safety Monitoring Board recommended premature termination after 342 patients were recruited. Infarct artery patency (grade 2 or 3) occurred in 79% of patients receiving recombinant tPA and in 53% of patients receiving urokinase (P <.001); Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow was 48% and 28%, respectively (P <.001). The higher-patency-rate recombinant tPA growth had better posttreatment left ventricular ejection fractions, 58.6% versus 54.7%, P <.01. Adverse events were infrequent and not significantly different in the 2 groups.

CONCLUSIONS

This study confirms that a substantially lower dose of recombinant tPA is effective in Asian patients compared with that required in Western patients even after consideration of body weight. Specific dose-response studies should be performed with fibrinolytic regimens to avoid overdosage with its attendant risks of excess bleeding.

Functional analysis of RET with Hirschsprung mutations affecting its kinase domain

BACKGROUND AND AIMS

Many missense mutations in the RET proto-oncogene were found in familial and sporadic cases of Hirschsprung disease (HSCR). The aim of this study was to make clear the mechanisms of RET dysfunction by HSCR mutations identified in its kinase domain.

METHODS

Ten kinase domain HSCR mutations were introduced into wild-type RET and constitutively activated RET with a multiple endocrine neoplasia 2A mutation, and the resulting mutant complementary DNAs were transfected into SK-N-MC primitive neuroectodermal tumor cells or NIH 3T3 fibroblast cells. The levels of activation of mutant RET and representative signaling molecules were investigated in the transfectants.

RESULTS

E762Q, S767R, R972G, and M980T mutations partially impaired the RET kinase activity and the representative signaling pathways. In particular, these mutations severely impaired the phospholipase C-gamma signaling pathway in SK-N-MC cells. S765P, R873Q, F893L, R897Q, and E921K mutations resulted in a complete loss of the RET kinase activity. The P973L mutation markedly decreased the expression of the RET protein with normal kinase activity.

CONCLUSIONS

Hirschsprung disease can result from these distant functional classes of kinase domain mutation of RET.

Differential effects of leukocyte common antigen-related protein on biochemical and biological activities of RET-MEN2A and RET-MEN2B mutant proteins

Protein-tyrosine-phosphatases (PTPs), in conjunction with protein-tyrosine kinases, play essential regulatory roles in diverse cellular activities by modulating the phosphorylation state of target proteins. Leukocyte common antigen-related (LAR) protein is a widely expressed receptor-type protein-tyrosine-phosphatase that is implicated in the regulation of intracellular signaling triggered by both cell adhesion and peptide growth factors. The gene for LAR is localized to human chromosome 1p32, a region frequently deleted in tumors of neuroectodermal origin, including neuroblastoma, pheochromocytoma, and medullary thyroid carcinoma. On the other hand, the RET gene codes for a transmembrane tyrosine kinase and is responsible for the development of multiple endocrine neoplasia (MEN) 2A and 2B. To explore the potential role of LAR in RET tyrosine kinase activity and RET-induced signal transduction, we cotransfected LAR and RET with a MEN2A or MEN2B mutation (designated RET-MEN2A or RET-MEN2B) into the NIH 3T3 cell line. Here we show that LAR reduces the constitutive tyrosine autophosphorylation and kinase activity of RET-MEN2A but not RET-MEN2B, accompanying a significant decrease of phosphorylation of phospholipase Cgamma, AKT, and ERK1/2. Interestingly, LAR expression significantly decreased the levels of disulfide-linked RET-MEN2A dimerization. Moreover, reduced oncogenic activity of RET-MEN2A by overexpression of LAR was observed both by an in vitro colony formation assay and by in vivo tumorigenicity in scid mice. These results thus suggest that LAR may contribute to deactivation of the RET-MEN2A mutant protein and reduction of its oncogenic activity in vivo.

"Hybrid" revascularization: video-thoracoscopy assisted MIDCAB combined with angioplasty

A "hybrid" revascularization technique has been developed for cases in which a chronic total occlusion of the left anterior descending coronary artery (LAD) cannot be recanalized by percutaneous coronary intervention, but the lesions in the right coronary artery and/or left circumflex artery are very good candidates for angioplasty. This technique, which uses video-thoracoscopy assisted minimally invasive direct coronary artery bypass to recanalize the occluded LAD and angioplasty to dilate favorable lesions in other vessels, would achieve complete revascularization in selected patients with multi-vessel disease. In this preliminary study of four patients, angioplasty and stenting were successful in all patients without any complications; complete revascularization was achieved in all 4 patients. No recurrence of angina and no cardiovascular events developed during follow-up; this study therefore supports the belief that the "hybrid" revascularization technique is both feasible and safe.