[Show abstract][Hide abstract] ABSTRACT: Association between dietary intake of vegetables and fruits and risk of hip fracture has been reported for many years. However, the findings remain inconclusive. We conducted a meta-analysis to evaluate the relationship between intake of vegetables and fruits, and risk of hip fracture. Literature search for relevant studies was performed on PubMed and Embase databases. Five observational studies were included in the meta-analysis. Summary hazard ratio (HR) with corresponding 95% confidence interval (CI) was calculated from pooled data using the random-effects model irrespective of heterogeneity. Sensitivity and subgroup analysis were performed to explore possible reasons for heterogeneity. The summary HR for hip fracture in relation to high intake vs. low intake of only vegetables, only fruits, and combined intake of fruits and vegetables, was 0.75 (95% CI, 0.61–0.92), 0.87 (95% CI, 0.74–1.04), and 0.79 (95% CI, 0.61–1.03), respectively. Subgroup analyses based on study design, geographical location, number of cases, and gender showed similar results. Increased intake of vegetables, but not fruits, was found to be associated with a lower risk of hip fracture. Large prospective clinical trials with robust methodology are required to confirm our findings.
Full-text · Article · Jan 2016 · Scientific Reports
[Show abstract][Hide abstract] ABSTRACT: Model:
, 2011, 51, 1474-1491), we reported a new de novo design method, namely Automatic Tailoring and Transplanting (AutoT&T). It overcomes some intrinsic problems in conventional fragment-based build-up methods. In this study, we describe an upgraded version, i.e. AutoT&T2. Structural operations conducted by AutoT&T2 have been largely optimized by introducing several new algorithms. As result, its overall efficiency in multi-round optimization jobs has been speeded up by a few thousand folds. With this improvement, it is now practical to conduct structural crossover among multiple lead molecules by using AutoT&T2. Three different test cases are described in this study, which demonstrate the new features and versatile applications of AutoT&T2. The AutoT&T2 software suite is available to the public. Besides, a web portal for running AutoT&T2 on-line is provided at http://www.sioc-ccbg.ac.cn/software/att2 for testing.
No preview · Article · Jan 2016 · Journal of Chemical Information and Modeling
[Show abstract][Hide abstract] ABSTRACT: MicroRNAs (miRNAs) are being developed to enhance tissue regeneration. Here we show that a hyperbranched polymer with high miRNA-binding affinity and negligible cytotoxicity can self-assemble into nano-sized polyplexes with a 'double-shell' miRNA distribution and high transfection efficiency. These polyplexes are encapsulated in biodegradable microspheres to enable controllable two-stage (polyplexes and miRNA) delivery. The microspheres are attached to cell-free nanofibrous polymer scaffolds that spatially control the release of miR-26a. This technology is used to regenerate critical-sized bone defects in osteoporotic mice by targeting Gsk-3β to activate the osteoblastic activity of endogenous stem cells, thus addressing a critical challenge in regenerative medicine of achieving cell-free scaffold-based miRNA therapy for tissue engineering.
Preview · Article · Jan 2016 · Nature Communications
[Show abstract][Hide abstract] ABSTRACT: Heterostructure engineering of atomically thin two-dimensional materials offers an exciting opportunity to fabricate atomically sharp interfaces for highly tunable electronic and optoelectronic devices. Here, we demonstrate abrupt interface between two completely dissimilar material systems, i.e, GaTe-MoS2 p-n heterojunction transistors, where the resulting device possesses unique electronic properties and self-driven photoelectric characteristics. Fabricated heterostructure transistors exhibit forward biased rectifying behavior where the transport is ambipolar with both electron and hole carriers contributing to the overall transport. Under illumination, photo-excited electron-hole pairs are readily separated by large built-in potential formed at the GaTe-MoS2 interface efficiently generating self-driven photocurrent within < 10 ms. Overall results suggest that abrupt interfaces between vastly different material systems with different crystal symmetries still allow efficient charge transfer mechanisms at the interface and are attractive for photo-switch, photo-detector, and photovoltaic applications owing to large built-in potential at the interface.
No preview · Article · Jan 2016 · ACS Applied Materials & Interfaces
[Show abstract][Hide abstract] ABSTRACT: 2D layered materials have attracted increasing interest, owing to their unique properties and large potential for versatile applications. As one of the 2D layered semiconductors, tin disulfide (SnS2) is rarely reported compared with other 2D materials like molybdenum disulfide (MoS2). Herein, high quality SnS2 flakes were grown by a facile and low-cost path, and photodetectors based on thin SnS2 flakes were fabricated and characterized. These flakes are of high quality according to the results of XRD, Raman and TEM measurements, and present hexagonal and half-hexagonal forms with an average diameter of 100 μm. The devices based on these SnS2 flakes showed wavelength dependent photo-responsive characteristics as the illuminating wavelength varied in the UV-Vis range (from 100 to 800 nm). They also showed excellent photo-responsive characteristics under monochromic illumination using three different wavelengths (533, 405 and 255 nm) with high photo-responsivity and high external quantum efficiency (EQE). The experimental results agree well with the first-principles calculated band structure and optical absorption coefficient curve.
[Show abstract][Hide abstract] ABSTRACT: The structural, electronic, and magnetic properties of the GaS monolayer doped by 12 different kinds of atoms were investigated systemically using first-principles calculations. N is found to be the most promising candidate for p-type doping among dopants at the S site, including nonmetal atoms H, B, C, N, O, and F and transition metal atoms V, Cr, Mn, Fe, Co, and Ni. Transition metal atoms appear to be hardly incorporated in the GaS monolayer under either S- or Ga-rich conditions. While the net magnetic moments of doped GaS by nonmetal atoms are either 0 or 1 μB, the value of transition metal dopants decreases from 5 to 0 μB by adding the number of valence electrons from V to Ni. In the case of transition metal dopants at the Ga site, the majority spin states of Cr and Co are located closest to the conduction band minimum and valence band maximum, respectively. Magnetic ground states exist in all of the monolayers doped by these impurities. Indirect band gap of the pristine GaS monolayer is regulated to be direct from one type of spin channel by introducing B and Mn in the S site and V, Fe, Co, and Ni in the Ga site.
No preview · Article · Dec 2015 · The Journal of Physical Chemistry C
[Show abstract][Hide abstract] ABSTRACT: L-Aspartate-β-semialdehyde dehydrogenase (ASADH) is a key enzyme in the aspartate pathway. In bacteria, ASADH is highly specific for the cofactor NADP(+) rather than NAD(+) . Limited information on cofactor utilization is available, and neither the wild-type protein nor the available mutants could utilize NAD(+) efficiently. In this study, we identified several residues crucial for cofactor utilization by Escherichia coli ASADH (ecASADH) by mutating residues within the cofactor binding center. Among the investigated mutants, ecASADH-Q350N and ecASADH-Q350N/H171A, which exhibited markedly improved NAD(+) utilization, were further investigated by various biochemical approaches and molecular modeling. Relative to the wild type, the two mutants showed approximately 44-fold and 66-fold increases, respectively, in the constant kcat /Km of NAD(+) . As desired, they could also utilize NADH efficiently to synthesize L-homoserine in cascade reactions in vitro.
[Show abstract][Hide abstract] ABSTRACT: Surface trap defects are the limited factor for quantum dots (QDs) application in solar cells. The trapping states can be efficiently suppressed by coating a shell of wider band gap material around the core QDs. We choose CdSe0.65Te0.35 (simplified as CdSeTe) as a model core material, and CdS shell was then overcoated around the CdSeTe core QD to decrease surface defect density and to increase the stability of the core QDs. By optimizing the thickness of the CdS shell, the power conversion efficiency (PCE) of the CdSeTe/CdS quantum dots sensitized solar cells (QDSCs) is enhanced by 13% in comparison with that of plain CdSeTe QDSCs. Transient absorption (TA), incident-photo-to-carrier conversion efficiency (IPCE), open-circuit voltage decay (OVCD), and electrochemical impedance spectroscopy (EIS) measurements confirmed the suppressed charge recombination process in internal QDs and QD/TiO2/electrolyte interfaces with the overcoating of CdS shell around CdSeTe core QDs. With the further overcoating of a-TiO2 and SiO2 barrier layers around the QD-sensitized photoanode, the PCE of champion CdSeTe QDSCs achieved 9.48% (Jsc = 20.82 mA/cm2, Voc = 0.713 V, FF = 0.639) with average PCE 9.39 ± 0.09% under AM 1.5 G one full sun illumination.
No preview · Article · Dec 2015 · The Journal of Physical Chemistry C
[Show abstract][Hide abstract] ABSTRACT: Body size, one of the most important quantitative traits under evolutionary scrutiny, varies considerably among species and
among populations within species. Revealing the genetic basis underlying this variation is very important, particularly in
humans where there is a close relationship with diseases and in domestic animals as the selective patterns are associated
with improvements in production traits. The Debao pony is a horse breed with small body size that is unique to China; however,
it is unknown whether the size-related candidate genes identified in Western breeds also account for the small body size of
the Debao pony. Here, we compared individual horses from the Debao population with other two Chinese horse populations using
SNPs identified with the Equine SNP 65 Bead Chip. The previously reported size-related candidate gene HMGA2 showed a significant signature for selection, consistent with its role observed in human populations. More interestingly,
we found a candidate gene TBX3, which had not been observed in previous studies on horse body size that displayed the highest differentiation and most significant
association, and thus likely is the dominating factor for the small stature of the Debao pony. Further comparison between
the Debao pony and other breeds of horses from around the world demonstrated that TBX3 was selected independently in the Debao pony, suggesting that there were multiple origins of small stature in the horse.
Preview · Article · Dec 2015 · Genome Biology and Evolution
[Show abstract][Hide abstract] ABSTRACT: Here, silica (SiO2) supported silver nano-particles (Ag NPs) and graphene quantum dots (GQDs) compounds were designed and synthesized via a “green” photochemical approach and an electrophoresis deposition technique in order to provide a highly active surface-enhanced Raman scattering (SERS) substrate. In this approach, the electrochemically prepared aqueous solution of GQDs was used as a solvent and a reducing agent to synthesize in-situ Ag-GQDs compounds under Ultraviolet (UV) irradiation. These compounds were collected on a SiO2 supported Si substrate through the electrophoresis deposition technique. Benefiting from their proper size (1–4 nm) and distribution in the spatial gaps between adjacent Ag NPs, GQDs could act as “hot spot” sites for lighting up the Raman scattering signals. Together with the enhanced adsorption of Rhodamine 6G (R6G) molecules through π-π stacking, the electrostatic interactions from GQDs, and the enlarged specific surface area provided by the SiO2 template, the as-prepared substrate exhibited a strong SERS signal with excellent reproducibility. The detection limit of R6G was pushed to 8.0 × 10−14 M. We hope our work provides a time-saving and facile approach for the design and creation of ultrasensitive SERS substrate for trace species detection.
No preview · Article · Dec 2015 · Journal of Alloys and Compounds
[Show abstract][Hide abstract] ABSTRACT: Due to the metastable property and arduous preparation, to control the size and shape of intermediate Sn
nanocrystals to tune functional properties still poses great challenge, and the physical and chemical properties are not fully investigated. Here, we report a simple one-pot template-free hydrothermal route to fabricate Sn
flower-like hierarchical structures self-assembled by aligned high-density nanoslices. In order to explore the growth mechanism, a series of samples with various hydrothermal time were prepared and examined by FESEM and Raman. Results show that the hydrothermal time influences the phases and morphology of the final products. Particularly, a sensor based on these Sn
was implemented to investigate the potential of Sn
for the ethanol detection, revealing that this material reacts to ethanol in a linear way with high response yet at lower temperature (190°C) than that of the well-known SnO
. Also, this intermediate tin oxide with rational control over dimension and morphology provides new opportunities for practical applications in gas sensing towards other reducing gases.
No preview · Article · Dec 2015 · Journal of Nanomaterials
[Show abstract][Hide abstract] ABSTRACT: Objective:
The incidence of gastric cancer is high in Chinese Tibetan. This study aimed to identify the differentially expressed microRNAs (miRNAs) and further explore their potential roles in Tibetan with gastric cancer so as to predict potential therapeutic targets.
A total of 10 Tibetan patients (male:female = 6:4) with gastric cancer were enrolled for isolation of matched gastric cancer and adjacent non-cancerous tissue samples. Affymetrix GeneChip microRNA 3.0 Array was employed for detection of miRNA expression in samples. Differential expression analysis between two sample groups was analyzed using Limma package. Then, MultiMiR package was used to predict targets for miRNAs. Following, the target genes were put into DAVID (Database for Annotation, Visualization and Integrated Discovery) to identify the significant pathways of miRNAs.
Using Limma package in R, a total of 27 differentially expressed miRNAs were screened out in gastric cancer, including 25 down-regulated (e.g. hsa-miR-148a-3p, hsa-miR-148b-3p and hsa-miR-363-3p) and 2 up-regulated miRNAs. According to multiMiR package, a number of 1445 target genes (e.g. Wnt1, KLF4 and S1PR1) of 13 differentially expressed miRNAs were screened out. Among those miRNAs, hsa-miR-148a-3p, hsa-miR-148b-3p and hsa-miR-363-3p were identified with the most target genes. Furthermore, three miRNAs were significantly enriched in numerous common cancer-related pathways, including "Wnt signaling pathway", "MAPK signaling pathway" and "Jak-STAT signaling pathway".
The present study identified a downregulation and enrichment in cancer-related pathways of hsa-miR-148a-3p, hsa-miR-148b-3p and hsa-miR-363-3p in Tibetan with gastric cancer, which can be suggested as therapeutic targets.
Preview · Article · Dec 2015 · Cancer Cell International
[Show abstract][Hide abstract] ABSTRACT: Th2-promoting cytokine IL-25 might contribute to bronchial mucosal vascular remodelling in asthma through its receptor expressed by vascular endothelial and vascular smooth muscle cells.
By utilising a newly established chronic asthma murine model induced by direct exposure of the airways to IL-25 alone, we examined effects of IL-25 on angiogenesis, vascular remodelling and expression of angiogenic factors, compared changes with those in a “classical” ovalbumin (OVA)-induced murine asthma model. IL-25 and OVA were intranasally instilled into the airways of BALB/c mice for up to 55 days. Airways vessels and angiogenic factors, including Von Willebrand Factor (vWF), amphiregulin, angiogenin, endothelin-1, transcription factor ERG, basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), insulin-like growth factor (IGF-1) and vascular endothelial growth factor (VEGF) in lung sections, homogenates and BAL fluid were detected and quantified by immunostaining or enzyme linked immunosorbent assay (ELISA). An in house assay was also utilised to compare the effects of IL-25 and other Th2-cytokines on angiogenesis by human vascular endothelial cells.
Repetitive intranasal challenge with IL-25 alone or OVA alone in OVA-presensitised animals significantly increased peribronchial vWF + vessels in the murine airways, which was associated with remarkably elevated expression of amphiregulin, angiogenin, endothelin-1, bFGF, EGF, IGF-1, VEGF and ERG. IL-25, but not Th-2-cytokines induced human angiogenesis in vitro.
The data suggest that chronic exposure of murine airways to IL-25 alone is able to reproduce a local angiogenic milieu. Thus, blocking IL-25 may attenuate vascular remodelling and improve outcomes in asthma patients.
Preview · Article · Dec 2015 · Respiratory Research
[Show abstract][Hide abstract] ABSTRACT: Charge recombination at an electrode/electrolyte interface is the main factor to limit the power conversion efficiency (PCE) of quantum dot sensitized solar cells (QDSCs). Herein, we present a novel and facile strategy based on successive coating of a sensitized electrode with a combination of blocking layers in appropriate sequence for suppressing the charge recombination. In this scenario, modification of the exposed surface of both TiO2 particles and QDs with an amorphous TiO2 (am-TiO2) layer via a classical TiCl4 hydrolysis treatment plays a fundamental role to enhance the effectiveness of a recombination blocking ZnS/SiO2 barrier layer. This strategy allows construction of CdSe0.65Te0.35 QD based champion QDSCs exhibiting a new PCE record of 9.28% and a certified PCE of 9.01% under full one sun illumination. The specific nature and sequence of the layering process is critical for the gain of photovoltaic performance. Control experiments indicate that the am-TiO2 is superior to a crystalline TiO2 layer in serving as the passivation/buffer layer and improving the photovoltaic performance of the cells. Insight from impedance spectroscopy (IS) and open circuit voltage decay (OCVD) measurements demonstrates that when the am-TiO2 layer is located at the interface between the QD sensitized photoanode and the ZnS/SiO2 barrier layer, it inhibits remarkably the charge recombination at the photoanode/electrolyte interface and prolongs the electron lifetime.
No preview · Article · Nov 2015 · Chemistry of Materials
[Show abstract][Hide abstract] ABSTRACT: Electrolysis-assisted calciothermic reduction method is proposed and successfully used to prepare ferrotitanium alloy from ilmenite by using equal-molar CaCl2-NaCl molten salt as electrolyte, molybdenum rod as cathode, and graphite as anode at 973 K with cell voltages of 3.2–4.4 V under inert atmosphere. Thermodynamics analysis of the process is presented, and the products obtained are examined with x-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy. It is demonstrated that the calciothermic reduction of ilmenite is a stepwise process since intermediate CaTiO3 is observed in the products partially reduced. In the calciothermic reduction process, the reduction of FeTiO3 first gives rise to the formation of Fe and CaTiO3, which as intermediates will further react with calcium metal to form ferrotitanium alloys. This is in good agreement with the prediction of thermodynamics. Experimental results also show that increasing cell voltage can accelerate the formation of calcium metal through electrolysis of CaO and CaCl2 and, hence, promote the calciothermic reduction of ilmenite. As the electrolytic zone and reduction zone are combined in the same bath, the theoretical energy requirement for the production of FeTi in the calciothermic process is lower than that in the aluminothermic process.
Full-text · Article · Nov 2015 · JOM: the journal of the Minerals, Metals & Materials Society
[Show abstract][Hide abstract] ABSTRACT: The structural, electronic, transport and optical properties of black phosphorus/MoS 2 (BP/MoS 2) van der Waals (vdw) heterostructure are investigated by using first principles calculations. The band gap of BP/MoS 2 bilayer decreases with the applied normal compressive strain and a semiconductor-to-metal transition is observed when the applied strain is more than 0.85 Å. BP/MoS 2 bilayer also exhibits modulation of its carrier effective mass and carrier concentration by the applied compressive strain, suggesting that mobility engineering and good piezoelectric effect can be realized in BP/MoS 2 heterostructure. Because the type-II band alignment can facilitate the separation of photo-excited electrons and holes, and it can benefit from the great absorption coefficient in ultra-violet region, the BP/MoS 2 shows great potential to be a very efficient ultra-violet photodetector.
[Show abstract][Hide abstract] ABSTRACT: The in situ electroreduction mechanism of solid PbO in choline chloride-ethylene glycol deep eutectic solvent (ChCl-EG DES) is preliminarily clarified through systematical investigations at cell voltage 2.5 V and 353 K. Cyclic voltammetry of the cavity microelectrode loaded with PbO powders exhibits that solid PbO can be direct electrochemically reduced to metallic lead and increasing scan numbers is beneficial to the deoxidation process. Potentiostatic electrolysis with an assumed cathode of PbO pellet and a graphite anode shows that generated numerous gases are mainly composed of O2 with small amounts of Cl2 at anode whereas H2 is released and preferentially adsorbed on the surface of reduced metallic lead at cathode. Parts of Cl2 can remain in the electrolyte and react with it to form oxidizing Cl-3 ions. Besides, the dissolution-electrodeposition of PbO(s) → [PbO·Cl·EG]- → Pb(s) exists simultaneously with the direct deoxidation of PbO(s) → Pb(s) during the electrolysis process. ESI-MS analysis implies that complex anions [PbO·Cl·EG]- and [ChCl·O·EG]2- are formed in ChCl-EG-PbO solution before and after the deoxidation process, respectively. Furthermore, a reduction mechanism model of PbO bulk to metallic lead in ChCl-EG DES is proposed. The in situ electrolysis process takes place initially at the current collector/PbO/electrolyte 3PIs and then new formed Pb/PbO/electrolyte 3PIs expands until the whole bulk are metallized. These findings provide a basis for scientifically in-depth discussion on the implication and optimization of the electrochemical production of metals and alloys from metal oxides.
No preview · Article · Nov 2015 · Electrochimica Acta
[Show abstract][Hide abstract] ABSTRACT: Gastric cancer is one of the most common cancers of digestive system globally and Helicobacter pylori (HP) infection is believed to be a major risk factor. HP can be classified into different types based on the presence and expression level of CagA and VacA, and, when exposed to adverse environment, HP changes its phenotype from helical type to coccoid type, with each having different pathogenicity. The mechanisms of HP-induced gastric carcinogenesis and progression are complicated, including DNA nitration and oxidation induced by mutagenic factors, HP-induced epigenetic modifications, HP-induced disruption of the balance between cell proliferation and apoptosis, and HP-induced cancer cell invasion and metastasis. HP may also affect the biological function of cancer stem cells and induction of cell autophagy. The lipopolysaccharide produced by HP can act through toll-like receptor-4 (TLR-4) to induce gastric mucosal inflammation and is thereby linked to the development of gastric cancer.
No preview · Article · Nov 2015 · Discovery medicine