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ZnO–SnO 2 branch–stem nanowires were fabricated on a Cu foil using a chemical vapor deposition system through a two-step process. Firstly, SnO 2 NWs were synthesized directly on a Cu foil substrate by evaporating SnO powder as a source material. Then, the as-synthesized SnO 2 NWs were used as templates for the growth of ZnO–SnO 2 branch–stem NWs. The effect of growth time on the growth of the SnO 2 NWs on the Cu foil was studied. The gas sensing properties of the SnO 2 NW and ZnO–SnO 2 branch–stem NW devices were studied using various toxic gases at different temperatures. Both devices exhibited high sensitivity, high selectivity, fast response and recovery times, and stability toward H 2 S gas. Compared to the pristine SnO 2 NW device, the ZnO–SnO 2 branch–stem NW device exhibited higher sensitivity and faster response rate toward H 2 S. Finally, the gas sensing mechanism was also discussed. [Display omitted] [ABSTRACT FROM AUTHOR]

• The protective effect of HLA-B*57:01/58:01 on HIV-1 CRF01_AE infection was examined. • The protective impact is impaired against CRF01_AE infection. • TW10-specific CD8+ T cells select for T242N even in CRF01_AE with viral fitness cost. • Less non-TW10 epitope presentation may contribute to the impaired protective impact. Human Leukocyte Antigen HLA-B*57:01 and B*58:01 are considered anti-HIV-1 protective alleles. HLA-B*57:01/58:01-restricted HIV-1 Gag TW10 (TSTLQEQIGW, Gag residues 240-249) epitope-specific CD8+ T cell responses that frequently select for a Gag escape mutation, T242N, with viral fitness cost are crucial for HIV-1 control. Although this finding has been observed in cohorts where HIV-1 subtype B or C predominates, the protective impact of HLA-B*57:01/58:01 has not been reported in Southeast Asian countries where HIV-1 CRF01_AE is the major circulating strain. Here, the effect of HLA-B*57:01/58:01 on CRF01_AE infection was investigated. The correlation of HLA-B*57:01/58:01 with viral load and CD4 counts were analyzed in the CRF01_AE-infected Vietnamese cohort (N = 280). The impact of the T242N mutation on CRF01_AE replication capacity was assessed. HLA-B*57:01/58:01 -positive individuals mostly had HIV-1 with T242N (62/63) but showed neither a significant reduction in viral load nor increased CD4 counts relative to B*57:01/58:01 -negative participants. In vitro and in vivo analyses revealed a significant reduction in viral fitness of CRF01_AE with T242N. In silico analysis indicated reduced presentation of epitopes in the context of CRF01_AE compared to subtype B or C in 10/16 HLA-B*57:01/58:01-restricted HIV-1 epitopes. The protective impact of HLA-B*57:01/58:01 on CRF01_AE infection is impaired despite strong suppressive pressure by TW10-specific CD8+ T cells. [ABSTRACT FROM AUTHOR]

Abstract: Streptococcus pneumoniae (pneumococcus) is responsible for significant morbidity and mortality in worldwide. After introduction of current pneumococcal vaccines, a marked decrease in the incidence of pneumococcal disease was observed. Unfortunately, serotype shifts in carriage and disease, including capsular switch and presence of antimicrobial resistance, have been found. Here we report live attenuated vaccine strain which is avirulent and can protect from systemic and mucosal pneumococcal diseases. Pep27, an autolysis-inducing factor of S. pneumoniae is known to mediate LytA-dependent and -independent lysis and it was thus expected to effect virulence. The loss of Pep27 had a much larger than expected decrease in virulence and has made the Pep27 mutant strain sufficiently avirulent to be used as a live vaccine. The pep27 mutation unexpectedly had lower level of capsular polysaccharide than the wild type (type 2, D39) strain. Moreover, the pep27 mutant showed rapid clearance by 24h post intranasal infection, and was not detected in lung and blood suggesting that mutant could not invade into the tissue. Even when 2×108 CFU were injected intravenously the mutant was not detected in the blood or brain after 4h. Whereas 4h after injection of 6×106 CFU of the wild type parent D39 strain, bacteremia was readily detected. Two dose intranasal immunizations with the live pep27 mutant in the absence of adjuvant elicited IgG antibody and serotype-independent protection against lethal intranasal challenge. Thus Pep27 was essential for virulence, and intranasal immunization with the pep27 mutant could provide protective immunity. [Copyright &y& Elsevier]

Elephantopus mollis Kunth (EM), which belongs to Asteraceae family, has been used as a folk medicine with diverse therapeutic properties. Previous studies reported that crude extracts of this plant could inhibit several cancer cell lines, including breast carcinoma MCF-7, liver carcinoma HepG2, colorectal carcinoma DLD-1, lung carcinoma NCI–H23, etc. In this study, the anticancer activity and associated molecular mechanism of EM which is distributed in Vietnam were investigated. The cytotoxicity of various EM extracts was evaluated on different cell lines by MTT assay. In addition, the effects of EM extracts on cell growth, cell morphology, nuclear morphology, caspase-3 activation, and mRNA expression levels of apoptosis-related genes were also examined. Our results demonstrated that ethyl acetate extract (EM-EA) caused proliferative inhibition and apoptotic induction towards A549 lung cancer cells (IC 50 = 18.66 μg/ml, SI = 5.8) and HL60 leukemia cells (IC 50 = 7.45 μg/ml, SI = 14.5) while petroleum ether extract (EM-PE) showed high toxicity to HL60 cell line (IC 50 = 11.14 μg/ml, SI = 6.7). Notably, Raji lymphoma cells were also affected by these extracts (IC 50 < 20 μg/ml, SI > 4), which has not been reported yet. Furthermore, mechanisms of EM extracts were elucidated. The significant downregulation of PCNA mRNA level induced by EM-EA/PE extracts contributed to the cell-growth restraint. EM-EA extract might activate apoptosis in A549 cells through both extrinsic and intrinsic signaling pathways by causing a 1.55-fold increase in BID , 3.65-fold increase in BAK and 3.11-fold decrease in BCL-2 expression level. Meanwhile, with EM-EA-extract treatment, HL60 cells might encounter P53-dependent apoptotic deaths. The combination of antiproliferation and apoptosis activation contributed to the high efficacy of EM extracts. These findings not only proved the anticancer potential of EM but also provided further insights into the mechanisms of EM extracts. Image 1 [ABSTRACT FROM AUTHOR]

This study aims to investigate the mutual effect of integrating alginate (Alg) into N,O-carboxymethyl chitosan (NOCC) – aldehyde hyaluronic acid (AHA) network regarding degradation behavior and biocompatibility of the hybrid hydrogel. The introduction of Alg not only generated the synergistic effect between electrostatic interaction and Schiff-base crosslinking, which was proved to significantly enhance the system stability and prolong degradation time, but also circumvented the limitation of bio-inert property of Alg-based composites. This approach is versatile and does not required extra effort to modify chemical compositions of the hydrogel components. Fourier Transform Infrared Spectroscopy (FT-IR) analysis was used to study the crosslinking mechanism of obtained fast gelling hybrid. The variation of volume ratios between three constituent components was found to modulate the gel-forming ability, biodegradation and biocompatibility of acquired hydrogel networks. Among investigated formulations, 6:4(1:1) NOCC-Alg-AHA sample possessed desired interconnected porous structure as shown by SEM technique, appropriate water uptake capacity, extended degradation time and excellent cell attachment and proliferation through in vitro studies, which is a promising injectable scaffold and/or encapsulating substrate for tissue engineering applications. Image 1 • Prolong degradation rate of NOCC - AHA hydrogel without chemical modification by adding Alg. • Investigate the effect of hybrid crosslink at different volume ratio of NOCC, AHA and Alg. • Resolve the bio-inert of Alg to enhance cell adhesion and proliferation by endogenous interactions within the system. • Be used as an in-situ base to load inorganic phases, cells or drugs for further application in tissue engineering. [ABSTRACT FROM AUTHOR]

Electrochromic devices (ECDs) rely on interfacial charge-transfer and ion transport. They generally suffer from a decline in their operational performance, which is caused by irreversible redox reactions, ion accumulation, or overpotential at the solution/electrode interface. Herein, we implement high-performance ECDs with excellent optical modulation (45.9%), fast switching speed (3 s), high coloring efficiency (98.1 cm2/C), and excellent long-term performance (>1000 cycles) under the bias of 0.7 V through in-depth optimization of device components and modulation of its driving characteristics. Three requirements for device structure and operation were considered to implement high-performance ECDs; i) uniformity and robustness of the electrochromic (EC) film in the working electrode (WE), ii) high surface area and fast redox properties of the complementary electrode, iii) total offsetting of the charge applied in the device during the coloring/bleaching process. Various electrodeposition methods such as galvanostatic, potentiostatic, pulsed potential, and triple pulse potential application were exploited to fabricate the active layers, and the active layers produced under optimized conditions through individual studies on the most stable film stability, electrochemical behavior, EC and ion storage characteristics were assembled in the devices. Under all optimized conditions, we constructed high-performance ECDs composed of electrodeposited Prussian blue (PB) as an EC layer and tungsten trioxide (WO 3) as a complementary layer, respectively. In particular, the offset of the charge applied to the device between the coloring and bleaching processes drastically improved the long-term stability of EC performance under low operating bias. The results provide a useful basis for enhancing the performance of ECDs and can be widely applied to various ECDs. [ABSTRACT FROM AUTHOR]