螺旋藻多糖的药理作用研究

螺旋藻多糖（Ｐｏｌｙｓａｃｃｈａｒｉｄｅ ｏｆ Ｓｐｉｒｕｌｉｎａ）是从螺旋藻中提取的一种无毒的天然产物,具有多种生物学活性。为进一步探讨螺旋藻多糖的作用,本文以小鼠为动物模型,观察极大藻多糖对小鼠生物功能的影响。螺旋藻多糖可以提高受γ射线致死剂量照射的小鼠３０天内的存活率促进小鼠多能干细胞和造血祖细胞的增殖和分化;促进受到辐射损伤的小鼠造血系统的恢复,增强小鼠的抗辐射能力。螺旋藻多糖可以提高小鼠     

Expression and Purification of the BmK M1 Neurotoxin from the Scorpion Buthus martensii Karsch

The gene encoding a neurotoxin (BmK M1) from the scorpion Buthus martensii Karsch was expressed in Saccharomyces cerevisiae at a high level with the alcohol dehydrogenase promoter. SDS–PAGE of the culture confirmed expression and showed secretion into medium from yeast. Recombinant BmK M1 was purified rapidly and efficiently by ion exchange and gel filtration chromatography to homogeneity, produced a single band on tricine–SDS–PAGE, and processed the homologous N-terminus. Amino acid analysis and N-terminal sequencing demonstrated that the recombinant toxin was processed correctly from the α-mating factor leader sequence and was chemically identical to the native form. The expressed recombinant BmK M1 was toxic for mice, which indicated that it was biologically active. Quantitative estimation showed that recombinant BmK M1 had an LD₅₀ similar to that of the native toxin.     

ClC-2 Activation Modulates Regulatory Volume Decrease

ClC-2 belongs to a large family of chloride channels and its expression in certain cell types is associated with the appearance of swelling-activated chloride (Cl⁻) currents. In the present report, we examined the hypothesis that ClC-2 plays a role in regulatory volume decrease by expressing ClC-2 in Sf9 cells using the baculovirus system. First, we showed that ClC-2 protein expression is associated with appearance of a Cl⁻ conductance which is activated by hypo-osmotic shock and can be distinguished from swelling-activated chloride currents endogenous to Sf9 cells on the basis of its pharmacology and specific inhibition by an anti-ClC-2 antibody. Second, we show that the rate of regulatory volume decrease is significantly enhanced in Sf9 cells expressing ClC-2 protein. Hence, our data support the hypothesis that ClC-2 is capable of mediating regulatory volume decrease. Received: 12 August/Revised: 23 October 1998     

湖北土荆芥挥发油化学成分研究

用色谱－质谱联用技术对湖北产土荆芥挥发油的化学成分进行了分析。鉴定了８０种组分。其中主要组分是：薄荷醇（３１．３３１％）α－松油烯（１３．２１０％）,香芹烯醇（８．５２６％）、对伞花烃（８．３４３％）、１,８－桉叶油素（７．４１７％）等５种化合物。被鉴定的８０种成分,共占挥发油总含量的９９．１１２％。     

The first baleen whale marine protected area proposed for Bryde's whales in the Beibu Gulf,China

The establishment of marine protected areas (MPAs) for cetaceans is an important strategy to mitigate human disturbance and protect biodiversity. Despite abundant cetacean species, there are only a few MPAs dedicated to cetacean conservation in China, all of which are for inshore dolphins. Bryde's whales, the only nearshore baleen whale population in mainland China, are conflicting with intensive human activities, yet an effective conservation strategy is lacking. This study used species distribution models to analyze distribution patterns and suitable habitats of Bryde's whales in the Beibu Gulf and proposes the first baleen whale MPA in China. Our results showed Bryde's whales have a seasonal distribution pattern in the Beibu Gulf, and that the waters around Weizhou Island and the southeastern coast of Vietnam were their core habitats. The seasonal nighttime light data indicated a negative relationship between the number of ship lights and Bryde's whale sightings and suggest that Bryde's whales might be threatened by fisheries. We proposed an MPA based on the results, suggesting that the waters within 20 km around Weizhou Island should be declared a protected area. Furthermore, we recommend that anthropogenic activities in the waters around Weizhou Island are better managed to reduce negative impacts on marine life.     

Unveiling The Mechanism of The Dendrite Nucleation and Growth in Aqueous Zinc Ion Batteries

Aqueous zinc ion batteries (ZIBs) exhibit great potential for next-generation energy storage devices. However, significant challenges exist, including the uncontrollable formation of Zn dendrite and side reactions during zinc stripping and plating. The mechanism of Zn dendrite nucleation has yet to be fully understood. In this work, the first principles simulations are used to investigate the Zn dendrite formation process. The unintentionally adsorbed O²⁻ and OH⁻ ions are the inducing factors for Zn dendrite nucleation and growth on the Zn (0001) plane due to significantly increased Zn diffusion barriers. A top-down method is demonstrated to suppress the dendrite using delaminated V₂CT_x to capture O²⁻ and OH⁻ ions thanks to reduced Zn diffusion barriers. The experimental results revealed significantly suppressed Zn dendrite nucleation and growth, resulting in a layer-by-layer deposit/stripping of Zn. Based on the electrochemical evaluations, the V₂CT_x-coated Zn composite delivers a high coulombic efficiency of 99.3% at 1.0 mAh cm⁻². Furthermore, the full cell achieves excellent cyclic performance of 93.6% capacity retention after 2000 cycles at 1 A g⁻¹. This strategy has broad scalability and can be widely applied in designing metallic anodes for rechargeable batteries.