高温对小鼠神经元骨架蛋白及热休克蛋白70表达的影响

目的:观察39℃环境对体外培养的小鼠皮层神经元骨架蛋白(β-tubulin)和热休克蛋白70(HSP70)表达的影响,探讨HSP70的神经保护作用. 方法:取小鼠胚胎大脑皮层进行神经元原代培养,将培养好的神经元分为37℃培养的对照组和39℃刺激30 min后0, 2, 6, 24和72 h的高温组. 分别进行荧光免疫染色,应用激光共聚焦扫描观察神经元β-tubulin和HSP70的表达. 结果:39℃刺激后,高温组神经元β-tubulin荧光强度均低于37℃对照组,且随着恢复时间的延长其荧光强度值逐渐升高. 高温组神经元HSP70荧光强度均高于37℃对照组,且随着恢复时间的延长其荧光强度值先升高后降低,于2 h时达高峰,24 h仍维持在较高的水平. 高温可导致HSP70荧光分布转移至细胞核,并随着恢复时间的延长逐渐转移至细胞浆. 结论:高温可以导致神经元形态变化,骨架蛋白结构紊乱可能是神经元形态变化的重要原因之一,HSP70可能参与并起到保护作用.     

哮喘发作与细胞骨架重建相关基因的差异表达

目的:研究外周血嗜酸性粒细胞(EOS)在哮喘发作时与细胞骨架相关基因的差异表达.方法:应用Super SMART cDNA synthesis技术从总RNA合成足量的双链cDNA. 经液相杂交消减两组共同序列,以抑制性PCR方式扩增差异表达序列. 构建上调与下调cDNA文库,菌落PCR扩增差异片段,应用差异筛选技术进一步鉴定差异表达基因并测序,结果通过核酸数据库进行同源性比较.结果:构建了高效的上调与下调消减cDNA文库,经鉴定及同源性分析有6个与细胞骨架重建有关,包括上调基因slingshot磷酸酶(SSH-2L),蛋白磷酸酶1β亚型(PP1Cβ),无功能糖基转移酶样蛋白(DOCK-8),蛋白酪氨酸磷酸酶非受体型6 (PTPN6)与非受体型12(PTPN12);下调基因,肌凝蛋白调节轻链结合蛋白(MIR).结论:这些骨架重建相关基因的差异表达可能参与了哮喘发作,进一步进行功能研究可能为哮喘治疗提供新的作用靶点.     

Half Metallic Ferromagnetism and Transport Properties of Zinc Chalcogenides ZnX2Se4 (X = Ti,V, Cr) for Spintronic Applications

In ferromagnetic semiconductors, the coupling of magnetic ordering with semiconductor character accelerates the quantum computing. The structural stability, Curie temperature (T_c), spin polarization, half magnetic ferromagnetism and transport properties of ZnX₂Se₄ (X = Ti, V, Cr) chalcogenides for spintronic and thermoelectric applications are studied here by density functional theory (DFT). The highest value of T_c is perceived for ZnCr₂Se₄. The band structures in both spin channels confirmed half metallic ferromagnetic behavior, which is approved by integer magnetic moments (2, 3, 4) μ_B of Ti, V and Cr based spinels. The HM behavior is further measured by computing crystal field energy ΔE _crystal, exchange energies Δ _x(d), Δ _x (pd) and exchange constants (N_o α and N_o β ). The thermoelectric properties are addressed in terms of electrical conductivity, thermal conductivity, Seebeck coefficient and power factor in within a temperature range 0–400 K. The positive Seebeck coefficient shows p-type character and the PF is highest for ZnTi2Se4 (1.2 × 10¹¹ W/mK²) among studied compounds.     

Curcumin May Prevent Basement Membrane Disassembly by Matrix Metalloproteinases and Progression of the Bladder Cancer

Authors present a review of crucial mechanisms contributing to the invasion of the basement membrane (BM) of the urothelium by cancer cells and to the progression of bladder cancer (BC). The breeching of the urothelial BM, facilitated by an aberrant activation of matrix metalloproteinases (MMP) is particularly perilous. Inhibition of activation of these proteinases constitutes a logic opportunity to restrain progression. Because of limited efficacy of current therapeutic methods, the search for the development of alternative approaches constitutes “the hot spot” of modern oncology. Recent studies revealed significant anticancer potential of natural phytochemicals. Especially, curcumin has emerged as a one of the most promising phytochemicals and showed its efficacy in several human malignancies. Therefore, this article addresses experimental and clinical data indicating multi-directional inhibitory effect of curcumin on the growth of bladder cancer. We particularly concentrate on the mechanisms, by which curcumin inhibits the MMP’s activities, thereby securing BM integrity and alleviating the eventual cancer invasion into the bladder muscles. Authors review the recently accumulating data, that curcumin constitutes a potent factor contributing to the more effective treatment of the bladder cancer.     

Quantum Hall Effect across Graphene Grain Boundary

Charge carrier scattering at grain boundaries (GBs) in a chemical vapor deposition (CVD) graphene reduces the carrier mobility and degrades the performance of the graphene device, which is expected to affect the quantum Hall effect (QHE). This study investigated the influence of individual GBs on the QH state at different stitching angles of the GB in a monolayer CVD graphene. The measured voltage probes of the equipotential line in the QH state showed that the longitudinal resistance (R_xx) was affected by the scattering of the GB only in the low carrier concentration region, and the standard QHE of a monolayer graphene was observed regardless of the stitching angle of the GB. In addition, a controlled device with an added metal bar placed in the middle of the Hall bar configuration was introduced. Despite the fact that the equipotential lines in the controlled device were broken by the additional metal bar, only the R_xx was affected by nonzero resistance, whereas the Hall resistance (R_xy) revealed the well-quantized plateaus in the QH state. Thus, our study clarifies the effect of individual GBs on the QH states of graphenes.     

Improving Fast Charging-Discharging Performances of Ni-Rich LiNi0.8Co0.1Mn0.1O2 Cathode Material by Electronic Conductor LaNiO3 Crystallites

Fast charging-discharging is one of the important requirements for next-generation high-energy Li-ion batteries, nevertheless, electrons transport in the active oxide materials is limited. Thus, carbon coating of active materials is a common method to supply the routes for electron transport, but it is difficult to synthesize the oxide-carbon composite for LiNiO₂-based materials which need to be calcined in an oxygen-rich atmosphere. In this work, LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) coated with electronic conductor LaNiO₃ (LNO) crystallites is demonstrated for the first time as fast charging-discharging and high energy cathodes for Li-ion batteries. The LaNiO₃ succeeds in providing an exceptional fast charging-discharging behavior and initial coulombic efficiency in comparison with pristine NCM811. Consequently, the NCM811@3LNO electrode presents a higher capacity at 0.1 C (approximately 246 mAh g⁻¹) and a significantly improved high rate performance (a discharge specific capacity of 130.62 mAh g⁻¹ at 10 C), twice that of pristine NCM811. Additionally, cycling stability is also improved for the composite material. This work provides a new possibility of active oxide cathodes for high energy/power Li-ion batteries by electronic conductor LaNiO₃ coating.     

Plant‐derived glucose transport inhibitors with potential antitumor activity

Glucose, a key nutrient utilized by human cells to provide cellular energy and a carbon source for biomass synthesis, is internalized in cells via glucose transporters that regulate glucose homeostasis throughout the human body. Glucose transporters have been used as important targets for the discovery of new drugs to treat cancer, diabetes, and heart disease, owing to their abnormal expression during these disease conditions. Thus far, several glucose transport inhibitors have been used in clinical trials, and increasing numbers of natural products have been characterized as potential anticancer agents targeting glucose transport. The present review focuses on natural product glucose transport inhibitors of plant origin, including alkaloids, flavonoids and other phenolic compounds, and isoprenoids, with their potential antitumor properties also discussed.     

耐甲氧西林金黄色葡萄球菌PBP2a 382～443片段的原核表达及鉴定

目的对编码耐甲氧西林金黄色葡萄球菌(MRSA)及青霉素结合蛋白2a(PBP2a)382~443位氨基酸的mecA基因片段进行克隆、表达及鉴定。方法根据基因文库登录的mecA基因的编码序列,针对编码PBP2a382~443位氨基酸的mecA基因片段,设计合成4条寡核苷酸片段,再将4条片段人工拼接成目的基因片段,然后克隆至PET-His载体,经酶切鉴定、测序正确后,转化E.coliBL21(DE3)plysS,用IPTG进行诱导表达,并对表达的蛋白以MRSA胶乳凝集试剂盒进行鉴定。结果构建了相应的PET-His克隆,经诱导表达和鉴定,证实成功表达出目的蛋白。结论成功表达出PBP2a382~443片段,为其进一步的纯化和应用奠定了基础。