Nanoporous gold with microporous structure prepared by sodium dodecyl sulfate-mediated electrochemical dealloying.

Nanoporous gold (NPG) is a promising catalytic material for the oxidation of CO and methanol applications. However, NPGs are prone to extensive macroscopic cracking that often decrease mechanic properties of NPGs and depresses their catalytic action. To produce crack-free NPG with an ultra-finer porosity in room temperature, the anionic surfactant sodium dodecyl sulfate (SDS) was added in electrochemical dealloying process. SDS has the effect of reducing the surface diffusion of gold which hinder the initial coarsening of ligaments and prevents interior silver atoms from being exposed and dissolved. As a result, the pore and ligment size are finer, but higher residual silver of NPG samples. NPG with pore size down to 2 nm and the ligament 4.0 nm was successfully fabricated with 13.32 mM SDS in perchloric acid solution. The surface diffusion coefficient of Au atoms was 1.6 × 10-24m2·s-1, nearly 3 orders of magnitude smaller than that of Au atoms in the absence of SDS (2.8 × 10-21m2·s-1). Nanoindentation results demonstrated that high residual silver content made NPG samples harder and stiffer，the specific surface areas of NPG with 6.66 mM SDS was 190 m2g-1by BET. This work provided very important clues on how to control the crack free ultrafine nanoporous structure of other materials.

Study on Effects of Titanium Surface Microporous Coatings Containing Zinc on Osteoblast Adhesion and Its Antibacterial Activity.

Metal surface structure/biomedical function integration is the current research focus. In previous studies, we have successfully prepared the microporous coatings containing zinc on the pure titanium surface by MAO. In the study, osteoblasts were seeded on the surface of the microporous coatings containing zinc and the adhesion of osteoblasts were evaluated, and the antibacterial activity of the microporous coatings containing zinc is observed through in vitro bacterial experiments. The result indicates that the adhesion ability of osteoblasts on the surface of microporous coatings containing zinc was very good, and the coatings could obviously inhibit the growth of Staphylococcus aureus and had good antibacterial activity. In conclusion, the microporous coatings containing zinc on titanium surface have good osteogenic and antibacterial properties and have good application prospect.

Uniform Nickel Vanadate (Ni3V2O8) Nanowire Arrays Organized by Ultrathin Nanosheets with Enhanced Lithium Storage Properties.

Development of three-dimensional nano-architectures on current collectors has emerged as an effective strategy for enhancing rate capability and cycling stability of the electrodes. Herein, a novel type of Ni3V2O8 nanowires, organized by ultrathin hierarchical nanosheets (less than 5 nm) on Ti foil, has been obtained by a two-step hydrothermal synthesis method. Studies on structural and thermal properties of the as-prepared Ni3V2O8 nanowire arrays are carried out and their morphology has changed obviously in the following heat treatment at 300 and 500 °C. As an electrode material for lithium ion batteries, the unique configuration of Ni3V2O8 nanowires presents enhanced capacitance, satisfying rate capability and good cycling stability. The reversible capacity of the as-prepared Ni3V2O8 nanowire arrays reaches 969.72 mAh · g(-1) with a coulombic efficiency over 99% at 500 mA · g(-1) after 500 cycles.

Three-Dimensional Porous Iron Vanadate Nanowire Arrays as a High-Performance Lithium-Ion Battery.

Development of three-dimensional nanoarchitectures on current collectors has emerged as an effective strategy for enhancing rate capability and cycling stability of the electrodes. Herein, a new type of three-dimensional porous iron vanadate (Fe0.12V2O5) nanowire arrays on a Ti foil has been synthesized by a hydrothermal method. The as-prepared Fe0.12V2O5 nanowires are about 30 nm in diameter and several micrometers in length. The effect of reaction time on the resulting morphology is investigated and the mechanism for the nanowire formation is proposed. As an electrode material used in lithium-ion batteries, the unique configuration of the Fe0.12V2O5 nanowire arrays presents enhanced capacitance, satisfying rate capability and good cycling stability, as evaluated by cyclic voltammetry and galvanostatic discharge-charge cycling. It delivers a high discharge capacity of 293 mAh·g(-1) at 2.0-3.6 V or 382.2 mAh·g(-1) at 1.0-4.0 V after 50 cycles at 30 mA·g(-1).

Polypyrrole-encapsulated vanadium pentoxide nanowires on a conductive substrate for electrode in aqueous rechargeable lithium battery.

Precursors of ammonium vanadium bronze (NH4V4O10) nanowires assembled on a conductive substrate were prepared by a hydrothermal method. After calcination at 360°C, the NH4V4O10 precursor transformed to vanadium pentoxide (V2O5) nanowires, which presented a high initial capacity of 135.0mA h g(-1) at a current density of 50mA g(-1) in 5M LiNO3 aqueous solution; while the specific capacity faded quickly over 50 cycles. By coating the surface of V2O5 nanowires with water-insoluble polypyrrole (PPy), the formed nanocomposite electrode exhibited a specific discharge capacity of 89.9mA h g(-1) at 50mA g(-1) (after 100 cycles). A V2O5@PPy //LiMn2O4 rechargeable lithium battery exhibited an initial discharge capacity of 95.2mA h g(-1); and after 100 cycles, a specific discharge capacity of 81.5mA h g(-1) could retain at 100mA g(-1).

Lack of association between Toll-like receptor 4 gene Asp299Gly and Thr399Ile polymorphisms and tuberculosis susceptibility: a meta-analysis.

OBJECTIVE: Toll-like receptor 4 (TLR4) plays a vital role in immunity to tubercle bacillus and its gene polymorphisms are supposed to affect tuberculosis susceptibility in some rather than all studies. Then, we integrated published data and performed a comprehensive meta-analysis to get more reliable estimations for the strength of associations between TLR4 gene polymorphisms and the risk of tuberculosis. METHODS: We systematically searched the electronic PubMed database for research articles about TLR4 gene polymorphisms and tuberculosis up to February 2012. Revman 5.0 software was adopted to conduct the meta-analysis. Crude odds ratio (ORs) and 95% confidence intervals (95% CIs) were calculated by either fixed-effects model or random-effects model. RESULTS: Finally, six case-control studies were identified, involving 1587 controls and 2110 patients. Overall, no significant associations were found between TLR4 gene Asp299Gly polymorphism and tuberculosis in the codominant models (GG vs AA: OR=1.56, 95% CI=0.76-3.21, P=0.23; GA vs AA: OR=1.01, 95% CI=0.84-1.23, P=0.89), the dominant model (GG+GA vs AA: OR=1.04, 95% CI=0.80-1.35, P=0.75), the recessive model (GG vs GA+AA: OR=1.55, 95% CI=0.75-3.19, P=0.24) and the allele model (G vs A: OR=1.06, 95% CI=0.81-1.40, P=0.66). Similarly, no significant associations between TLR4 gene Thr399Ile and tuberculosis were observed (all P>0.05). CONCLUSIONS: The present meta-analysis suggests that TLR4 gene Asp299Gly and Thr399Ile polymorphisms are not associated with the susceptibility of tuberculosis.

Anatomical variations of the upper thoracic sympathetic chain.

The aim is to clearly delineate the upper thoracic sympathetic chains and neural connections between the chains and ventral rami of the thoracic nerves, and to provide an anatomical foundation for successful upper thoracic sympathicotomy for treating upper essential hyperhidrosis. The upper thoracic sympathetic chains, upper five intercostal nerves, and neural connections between them in 50 halves of 25 adult cadavers have been dissected, measured, and mapped. The stellate ganglion had an incidence of 80%. The second to the fourth thoracic sympathetic ganglia were commonly located in the corresponding intercostal spaces with the presence of 92%, 68%, and 50%, respectively. The incidence of the first and second intercostal rami was 40% and 6%, and that of the ascending or descending rami from the second, third and fourth ganglia was 54%, 24%, and 14%, respectively. Additional rami communicantes joined the ventral ramus of the 1st thoracic nerve proximal to the point where the latter gave a branch to the brachial plexus. The farthest horizontal distance from the sympathetic chain to the junction between the additional rami communicantes and the second to the fourth intercostal nerves was 29.1 mm. Only 16% of cadavers had similar anatomy bilaterally. Anatomical variations of the upper thoracic sympathetic trunk in relation to intercostal nerves, which may be one of the causes resulting in surgical failures and recurrences, were striking. Attention should be given to such anatomical variations when planning thoracic sympathicotomy.

[The clinical application and research on vas deferens laser coagulation sterilization].

OBJECTIVE: To study the effect of Ar(+) laser on human vas deferens and to compare the effects of using different radiation levels with varying thickness of tissue and varying levels of injury. METHODS: After initial tests on animals, four human scrotums were opened and treated directly with Ar(+) laser radiation. Then 58 human individual scrotums were treated with radiation by the method of trans-skin puncture. The rate of sperm reduction and elimination was tested. RESULTS: In 60 cases, the sperms were found to be eliminated completely after six months of radiation treatment. In 2 cases the sperms were found not to be eliminated completely due to the insufficient radiation. CONCLUSION: Ar(+) laser is one of the best forms of radiation for coagulation of vas deferens. It can be used to coagulate vas deferens without any complications or sequelae.