Electron self-energy and effective mass in a single heterostructure

In this paper, we investigate the electron self-energy and effective mass in a single heterostructure using Green-function method. Numerical calculations of the electron self-energy and effective mass for GaAs/AlAs heterostructure are performed. The results show that the self energy (effective mass) of electron, which incorporate the energy of electron coupling to interface-optical phonons and half three-dimension LO phonons, monotonically increase(decrease) from that of interface polaron to that of 3D bulk polaron with the increase of the distance between the position of the electron and interface.Comment: 10 pages, 2 figure

Effective Silencing of Sry Gene with RNA Interference in Developing Mouse Embryos Resulted in Feminization of XY Gonad

Delivering siRNA or shRNA into the developing embryos is still a main challenge to use of RNAi in mammalian systems. Here we analyze several factors influencing RNAi-mediated silencing of Sry gene, which is a tightly controlled spatiotemporal expressed gene and only shortly expressed in developing mouse embryo gonad. A Sry gene-specific shRNAs expression vector (pSilencer4.1/Sry565) was constructed. The shRNA constructs were mixed with polyethylenimines (PEIs) to form a complex and then injected into pregnant mice though tail vein. Our results showed that Sry gene was downregulated significantly in developing embryos. Further study revealed that knocking-down of Sry expression resulted in feminization of gonad development in mouse embryos and the expression level of Sox9 and Wt1 gene was also significantly changed by downregulation of Sry. The transfection efficiency is associated with the amount of plasmid DNA injection, injection time, injection speed, and volume. Our studies suggest that transplacental RNAi could be implemented by tail vein injection of plasmid vector into pregnant mice

Longitudinal associations between triglycerides and metabolic syndrome components in a Beijing adult population, 2007-2012

Background: Longitudinal associations between triglycerides (TG) and other metabolic syndrome (MetS) components have rarely been reported. The purpose was to investigate the longitudinal association between TG and other MetS components with time. Methods: The longitudinal study was established in 2007 on individuals who attended health check-ups at Beijing Tongren Hospital and Beijing Xiaotangshan Hospital. Data used in this study was based on 7489 participants who had at least three health check-ups over a period of 5-year follow up. Joint model was used to explore longitudinal associations between TG and other MetS components after adjusted for age. Results: There were positive correlations between TG and other MetS components except for high density lipoprotein (HDL), and the correlations increased with time. A negative correlation was displayed between TG and HDL, and the correlation also increased with time. Among all five pairs of TG and other MetS components, the marginal correlation between TG and body mass index (BMI) was the largest for both men and women. The marginal correlation between TG and fasting plasma glucose was the smallest for men, while the marginal correlation between TG and diastolic blood pressure was the smallest for women. Conclusions: The longitudinal association between TG and other MetS components increased with time. Among five pairs of TG and other MetS components, the longitudinal correlation between TG and BMI was the largest. It is important to closely monitor subjects with high levels of TG and BMI in health check-up population especially for women, because these two components are closely associated with development of hypertension, diabetes, cardiovascular disease and other metabolic diseases

Radiosensitization and growth inhibition of cancer cells mediated by an scFv antibody gene against DNA-PKcs in vitro and in vivo

<p>Abstract</p> <p>Background</p> <p>Overexpression of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) is commonly occurred in cancers and causes radioresistance and poor prognosis. In present study, the single-chain variable antibody fragments (scFv) targeting DNA-PKcs was developed for the application of radiosensitization in vitro and in vivo. A humanized semisynthetic scFv library and the phage-display antibodies technology were employed to screen DNA-PKcs scFv antibody.</p> <p>Methods</p> <p>DNA-PKcs epitopes were predicted and cloned. A humanized semisynthetic scFv library and the phage-display antibodies technology were employed to screen DNA-PKcs scFv antibody. DNA damage repair was analyzed by comet assay and immunofluorescence detection of γH2AX foci. The radiosensitization in vivo was determined on Balb/c athymic mice transplanted tumours of HeLa cells.</p> <p>Results</p> <p>Four epitopes of DNA-PKcs have been predicted and expressed as the antigens, and a specific human anti-DNA-PKcs scFv antibody gene, anti-DPK3-scFv, was obtained by screening the phage antibody library using the DNA-PKcs peptide DPK3. The specificity of anti-DPK3-scFv was verified, <it>in vitro</it>. Transfection of HeLa cells with the anti-DPK3-scFv gene resulted in an increased sensitivity to IR, decreased repair capability of DNA double-strand breaks (DSB) detected by comet assay and immunofluorescence detection of γH2AX foci. Moreover, the kinase activity of DNA-PKcs was inhibited by anti-DPK3-scFv, which was displayed by the decreased phosphorylation levels of its target Akt/S473 and the autophosphorylation of DNA-PKcs on S2056 induced by radiation. Measurement of the growth and apoptosis rates showed that anti-DPK3-scFv enhanced the sensitivity of tumours transplanted in Balb/c athymic mice to radiation therapy.</p> <p>Conclusion</p> <p>The antiproliferation and radiosensitizing effects of anti-DPK3-scFv via targeting DNA-PKcs make it very appealing for the development as a novel biological radiosensitizer for cancer therapeutic potential.</p

The Bone-Protecting Efficiency of Chinese Medicines Compared With Western Medicines in Rheumatoid Arthritis: A Systematic Review and Meta-Analysis of Comparative Studies

Background: Rheumatoid Arthritis (RA) is a systemic autoimmune disease leading to joint destruction. The prevention of bone and cartilage destruction has received increased attention in recent years.Objective: To evaluate the current evidences regarding the bone-protecting efficacy of Chinese medicine or the combination of Chinese medicine and Western medicine for RA.Methods: We comprehensively searched PubMed, Embase, the Cochrane Library (www.thecochranelibrary.com), the China National Knowledge Infrastructure (CNKI), the Database for Chinese Technical Periodicals (VIP), and SinoMed. We then performed a systematic review and cumulative meta-analysis of all randomized controlled trials (RCTs) assessing the two therapy methods.Results: Sixteen studies including 1,171 patients were included in the final analysis. The results showed that Chinese medicine could significantly improve the bone mineral density (BMD) (mean difference [MD] = 0.05 /g·cm−2, 95% CI [0.03, 0.08], P &lt; 0.00001), and decrease the serum matrix metalloproteinase 3 (MMP-3) ([SMD] = −2.84, 95% CI [−4.22, −1.47], P &lt; 0.0001).Conclusions: Chinese medicine may provide an efficiently alternative choice for the treatment of RA in terms of the bone-protecting efficiency. Given the inherent limitations of the included studies, future well-designed RCTs are required to confirm and update the findings of this analysis

Growth of highly nitrogen-doped amorphous carbon for lithium-ion battery anode

Amorphous nitrogen-doped carbon nanosheets was synthesized through thermal decomposition of ethylenediaminetetraacetic acid manganese disodium salt hydrate (C10H12N2O8MnNa22H2O). The as-synthesized nitrogen-doped carbon nanosheets were characterized by X-ray diffraction, scanning electron microscopy, transition electron microscopy and X-ray photoelectron spectroscopy. The N content of the as-synthesized carbon nanosheets could reach as high as 11.77 at.%, with an especially high total of 7.94 at.% pyridinic N pluspyrrolic N. When tested as anode material for lithium ion batteries, the optimized carbon nanosheets exhibited high capacity, excellent rate capability, and stable cyclability over 600 cycles. The specific capacity was still as high as 465.8 mAh g-1 at 0.5 C after 600 cycles,with a capacity decay from the 2nd cycle of 0.05% per cycle over 599 cycles. The excellent performance of C-600 is attributed to a synergistic effect of high surface area, numerous nanopores, high thermal stability, and low charge transfer resistance

Uniform Ni-rich LiNi0.6Co0.2Mn0.2O2 porous microspheres: facile designed synthesis and their improved electrochemical performance

A facile two-step synthetic route, i.e., combining the carbonate co-precipitation method and impregnation method, to prepare uniform porous Ni-rich LiNi0.6Co0.2Mn0.2O2 microsphere with an average diameter of ∼3 μm and BET specific surface area of 13.4 m2 g-1 is proposed for the first time. The XRD and TEM results confirm that the porous microspheres LiNi0.6Co0.2Mn0.2O2 material has a well-ordered α-NaFeO2 structure with stable in-plane [3x3]R30° ordering in the transition-metal layers. The exquisite morphology and ideal structure endow this nanocrystal-assembled porous LiNi0.6Co0.2Mn0.2O2 microspheres enhanced electrochemical performance such as high capacity, good cycling stability and excellent rate capability. Specifically, the as-prepared porous LiNi0.6Co0.2Mn0.2O2 cathode delivers a high discharge capacity of 79 mAh g-1 even at the ultrahigh rate 50C (10 A g-1), and 138 mAh g-1 at 1C after 100 cycles with an excellent cycle life. Additionally, the fast-charging test results are indicative of the fact that this cathode has sufficiently stable structure, because it can still deliver a discharge capacity higher than 123 mAh g-1 after 100 cycles with capacity retention of 90.1% at 5C charge and 1C discharge. The cyclic voltammetry (CV) and electrochemical impedance spectra (EIS) results demonstrate that the porous LiNi0.6Co0.2Mn0.2O2 cathode has a higher apparent lithium ion diffusion coefficient (insertion/extraction process are 8.67 x 10-8 and 3.78 x 10-8 cm2 s-1, respectively) and lower activation energy (29.3 KJ mol-1). Our results indicate that this preparation strategy may be facile and versatile for synthesis other high-capacity anode/cathode materials