油茶象甲形态特征及生物学特性研究

油茶象甲Curculio chinensis Chevrolat是油茶的重要果实害虫,为害严重林分果实被害率高达79.3%。本文详细描述了该虫的形态特征;对其生物学特性进行了研究,结果表明该虫在广东省2年发生1代,以老熟幼虫在土内越过第1个冬天、以初羽化的成虫在土内越过第2个冬天,4月上中旬开始出土,5-6月为出土盛期。成虫栖息环境、产卵和油茶果实的生长发育有密切的关系,成虫无交配时多栖息在油茶嫩枝、嫩芽或油茶果实基部的枯萎花絮上,成虫交配盛期多被发现在油茶果实上;油茶果实一般以果皮厚度4.0-6.0 mm着卵量最多,林间每果一般只有1粒卵或1头幼虫。     

Prokaryotic Community Structure Driven by Salinity and Ionic Concentrations in Plateau Lakes of the Tibetan Plateau

The prokaryotic community composition and diversity and the distribution patterns at various taxonomic levels across gradients of salinity and physiochemical properties in the surface waters of seven plateau lakes in the Qaidam Basin, Tibetan Plateau, were evaluated using Illumina MiSeq sequencing. These lakes included Lakes Keluke (salinity, <1 g/liter), Qing (salinity, 5.5 to 6.6 g/liter), Tuosu (salinity, 24 to 35 g/liter), Dasugan (salinity, 30 to 33 g/liter), Gahai (salinity, 92 to 96 g/liter), Xiaochaidan (salinity, 94 to 99 g/liter), and Gasikule (salinity, 317 to 344 g/liter). The communities were dominated by Bacteria in lakes with salinities of <100 g/liter and by Archaea in Lake Gasikule. The clades At12OctB3 and Salinibacter, previously reported only in hypersaline environments, were found in a hyposaline lake (salinity, 5.5 to 6.6 g/liter) at an abundance of ∼1.0%, indicating their ecological plasticity. Salinity and the concentrations of the chemical ions whose concentrations covary with salinity (Mg²⁺, K⁺, Cl⁻, Na⁺, SO₄²⁻, and Ca²⁺) were found to be the primary environmental factors that directly or indirectly determined the composition and diversity at the level of individual clades as well as entire prokaryotic communities. The distribution patterns of two phyla, five classes, five orders, five families, and three genera were well predicted by salinity. The variation of the prokaryotic community structure also significantly correlated with the dissolved oxygen concentration, pH, the total nitrogen concentration, and the PO₄³⁻ concentration. Such correlations varied depending on the taxonomic level, demonstrating the importance of comprehensive correlation analyses at various taxonomic levels in evaluating the effects of environmental variable factors on prokaryotic community structures. Our findings clarify the distribution patterns of the prokaryotic community composition in plateau lakes at the levels of individual clades as well as whole communities along gradients of salinity and ionic concentrations.     

Methane Concentration in the Heartwood of Living Trees and Estimated Methane Emission on Stems in Upland Forests

The stems of living trees in upland forests might contribute to the global methane (CH₄) source, but the contribution is poorly understood. We investigated CH₄ concentration in the heartwood of living trees in dominant upland forests using field campaign and subsequently evaluated the importance of stem CH₄ emission in the context of the global total. We found that only 0%, 9.8%, and 1.8% of stems of living trees had substantial CH₄ concentration in heartwood of?≥?10,000 μL L^–1 in the boreal, temperate, and tropical and subtropical upland forests investigated, respectively. CH₄ concentration in heartwood depended mainly upon tree species and subsequently soil moisture. Relationships fitted indicate that CH₄ concentration followed a power function with respect to water content in heartwood, whereas nitrous oxide (N₂O) or carbon dioxide (CO₂) concentration linearly increased with water content in heartwood. Stem CH₄ emission was estimated at approximately 0.2–2 Tg yr^–1 globally, corresponding to less than 0.4% of the global total including all natural plus anthropogenic sources. Water content in heartwood is positively associated with soil water content. Soil water content rarely exceeds 40% v/v in upland forests, indicating stem CH₄ emission occurs mainly in the areas of low-lying upland forests with occasionally moist soils. More attentions should be paid on low-lying upland forests and forested wetlands in future when stem CH₄ emission needs to be estimated in all forests.

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谷氨酸转运体GLT-1的剪接变异体研究进展

随着对谷氨酸转运体1(glial glutamate transporter 1, GLT-1)研究的深入,发现GLT-1存在多种剪接变异体.这些变异体除在中枢神经系统大量分布外,在受试动物的其它部位也有分布.中枢神经系统内的GLT-1剪接变异体在星形胶质细胞和神经元上均有表达,且这些剪接变异体在中枢神经系统的分布还呈现出区域定位及亚细胞定位不均衡的特性.     

低剂量氯胺酮对工作记忆的影响

氯胺酮是一种N-甲基-D-天冬氨酸受体（NMDAR）阻滞剂，低剂量氯胺酮具有良好的镇痛、抗炎和抗抑郁作用，近年来受到了广泛的关注。但是低剂量氯胺酮对于高级认知功能的影响尚未全面阐明。工作记忆是涉及众多复杂认知活动的关键功能，有研究显示低剂量氯胺酮急性或慢性使用均会损伤工作记忆，其神经机制也开始受到关注。深入分析低剂量氯胺酮对于工作记忆的影响及其机制对于指导氯胺酮的临床使用具有重要意义。本文首先介绍了低剂量氯胺酮作用于神经系统的药理作用途径，以及工作记忆本身的神经环路机制，进而回顾了近年来关于低剂量氯胺酮对工作记忆的急性和慢性作用的相关研究，并重点分析了低剂量氯胺酮损伤工作记忆的可能的神经机制，希望对低剂量氯胺酮在临床中的合理使用提供科学依据。     

Depletion of serum-derived exosomes aggravates heat stress-induced damage of bovine mammary epithelial cells

Molecular Biology Reports - Exosomes are involved in intercellular communication, affecting many physiological and pathological process. The present study evaluated the effects of serum exosomes on...