莫古礼(Floyd Alonzo McClure)在华采集和引种竹类植物的历史及其影响

竹类植物是美国采集者在我国采集和引种的一类主要植物。在众多的竹类植物采集者中, 莫古礼(Floyd Alonzo McClure)是最具代表性的一位, 他于1919-1940年在岭南大学开展竹类植物研究, 在此期间多次采集竹类植物标本并引种竹类植物到美国。本研究通过大量文献研究、档案查阅以及实地调研, 整理了莫古礼采集竹类植物的路线和采集地, 并对竹类植物学名进行校对, 分析了莫古礼在华研究、采集和引种竹类植物的历史及其影响。经统计, 莫古礼在华期间竹类植物标本采集地涉及12个省级行政区39个地级市, 主要集中在广东、海南、香港等地; 引种地涉及9个省级行政区的25个地级市; 共采集竹类植物标本727号1,840份, 隶属20属93种(含种下单位, 下同), 分别占我国竹类植物属和种的58.8%和17.4%; 共引种竹类植物255份, 隶属于17属77种, 分别占我国竹类植物属和种的50.0%和14.4%。莫古礼在华采集和引种竹类植物极大地发展了竹类植物分类学, 所采集的竹类植物标本为后人竹类植物研究提供了极大的帮助, 所引种的竹类植物极大丰富了美国竹类植物种类, 也促进了竹类植物在美国的应用。     

Level of protein kinase C activity correlates directly with resistance to adriamycin in murine fibrosarcoma cells

In this report, we demonstrate a direct correlation between protein kinase C (PKC) activity and adriamycin (ADR) resistance in mouse fibrosarcoma cells. PKC activity was measured in four murine UV-2237M fibrosarcoma cell lines that differed in the degrees to which they expressed resistance to ADR, which is an inhibitor of PKC. A comparison of the four cell lines revealed a positive correlation between the level of PKC activity and resistance to ADR. Incubation of the cells with the PKC inhibitor H-7 produced a partial reversal of ADR resistance. Taken together, these results suggest a role for PKC in the mechanism of ADR resistance.     

粳稻子预44中稻瘟病数量抗性位点分析

稻瘟病是世界范围内影响水稻(Oryza sativa)生产的主要病害。抗稻瘟病基因的发掘和育种利用是控制稻瘟病经济、环保的有效措施。为了揭示云南地方水稻品种子预44广谱持久抗瘟机制, 利用江南香糯和子预44杂交构建的F₇重组自交群体, 采用苗期稻瘟病菌自然诱发接种法, 通过调查田间抗瘟性表型数据, 结合基因型数据对子预44中的数量抗瘟性位点进行了分析。结果表明, 在连锁系数(logarithm of odds, LOD)大于2.0的域值上, 共检测出13个QTLs, 分别位于第1、2、6、8、12号染色体上。不同位点表型贡献值差异较大, 范围为5.8%-21.9%, 其中8号染色体上标记RM72-RM404之间的QTLs可解释约61.9%的表型变异, 很可能为一个主效抗瘟QTL位点。多个位点的主效和微效抗性相结合可能是子预44持久稻瘟病抗性的分子基础。     

MFN2 Couples Glutamate Excitotoxicity and Mitochondrial Dysfunction in Motor Neurons

Mitochondrial dysfunction plays a central role in glutamate-evoked neuronal excitotoxicity, and mitochondrial fission/fusion dynamics are essential for mitochondrial morphology and function. Here, we establish a novel mechanistic linker among glutamate excitotoxicity, mitochondrial dynamics, and mitochondrial dysfunction in spinal cord motor neurons. Ca²⁺-dependent activation of the cysteine protease calpain in response to glutamate results in the degradation of a key mitochondrial outer membrane fusion regulator, mitofusin 2 (MFN2), and leads to MFN2-mediated mitochondrial fragmentation preceding glutamate-induced neuronal death. MFN2 deficiency impairs mitochondrial function, induces motor neuronal death, and renders motor neurons vulnerable to glutamate excitotoxicity. Conversely, MFN2 overexpression blocks glutamate-induced mitochondrial fragmentation, mitochondrial dysfunction, and/or neuronal death in spinal cord motor neurons both in vitro and in mice. The inhibition of calpain activation also alleviates glutamate-induced excitotoxicity of mitochondria and neurons. Overall, these results suggest that glutamate excitotoxicity causes mitochondrial dysfunction by impairing mitochondrial dynamics via calpain-mediated MFN2 degradation in motor neurons and thus present a molecular mechanism coupling glutamate excitotoxicity and mitochondrial dysfunction.     

Adding Vitamin E-TPGS to the Formulation of Genexol-PM: Specially Mixed Micelles Improve Drug-Loading Ability and Cytotoxicity against Multidrug-Resistant Tumors Significantly

Genexol-PM, produced by Samyang Company (Korea) is an excellent preparation of paclitaxel (PTX) for clinical cancer treatment. However, it cannot resolve the issue of multidrug resistance (MDR)—a significant problem in the administration of PTX to cancer patients. To increase the efficacy of Genexol-PM against MDR tumors, a mixed micelle capable of serving as a vehicle for PTX was developed, and two substances were chosen as carrier materials: 1) Polyethylene glycol–polylactic acid (PEG-PLA), the original vehicle of Genexol-PM. 2) Vitamin E-TPGS, an inhibitor of P-glycoprotein (P-gp). P-gp has been proven to be the main cause of MDR. In vitro evaluation indicated that the mixed micelle was an ideal PTX delivery system for the treatment of MDR tumors; the mixed micelle also showed a significantly better drug-loading coefficient than Genexol-PM.     

隆德鱼的新材料及其系统关系的初步分析——辽宁西部晚中生代地层和鱼群研究之一

依据辽宁西部三个地点的新材料和宁夏、内蒙古的标本,对罗家峡隆德鱼(Longdeichthys luojiaxiaensis Liu,1982)的形态特征作了补充描述和修订,并初步分析讨论了“薄鳞鱼类”的研究现状以及隆德鱼的系统关系。认为隆德鱼可能已是鲱头鱼派(Clupeocephala)的成员,与德国和法国基末里期的Leptolepides sprattiformis(Blainville)最为相近。     

The Influence of Chronic Ego Depletion on Goal Adherence: An Experience Sampling Study

Although ego depletion effects have been widely observed in experiments in which participants perform consecutive self-control tasks, the process of ego depletion remains poorly understood. Using the strength model of self-control, we hypothesized that chronic ego depletion adversely affects goal adherence and that mental effort and motivation are involved in the process of ego depletion. In this study, 203 students reported their daily performance, mental effort, and motivation with respect to goal directed behavior across a 3-week time period. People with high levels of chronic ego depletion were less successful in goal adherence than those with less chronic ego depletion. Although daily effort devoted to goal adherence increased with chronic ego depletion, motivation to adhere to goals was not affected. Participants with high levels of chronic ego depletion showed a stronger positive association between mental effort and performance, but chronic ego depletion did not play a regulatory role in the effect of motivation on performance. Chronic ego depletion increased the likelihood of behavior regulation failure, suggesting that it is difficult for people in an ego-depletion state to adhere to goals. We integrate our results with the findings of previous studies and discuss possible theoretical implications.     

花生种子老化相关蛋白质的初步研究

本文以粤油 116花生(Arachis hypogaea L.)为材料,对不同处理种子的除子叶“种胚”(以下简称“种胚”)的蛋白质进行了研究.实验结果表明,当花生种子活力下降到一定程度时,其“种胚”内出现一种新蛋白质( pI6.2、MW 10 KD),随种子老化程度加深,含量逐渐增多.我们认为该蛋白质与花生种子老化存在着一定的相关关系,可作为该种子老化的标志.     

三峡库区三种林下地被物储水特性

通过对三峡库区3种森林类型(松栎混交林、栓皮栎纯林、马尾松纯林)林下地被物调查及其持水试验,分别得到3种森林类型林下地被物最大储水量、吸水速率等水文特征参数,结果表明,栓皮栎纯林林下苔藓层储水量最大,为其风干重的303．1％,松栎混交林林下的为283．8％,马尾松纯林林下的为242．3％．松栎混交林林下枯落物最大储水量为其风干重的282.2％,栓皮栎纯林林下的为262．5％,马尾松纯林林下的为239．3％。经分析拟合,得到林下苔藓层、林下枯落物吸水速率与浸泡时间之间关系式为S=kt^n,在同为中龄林条件下,3种森林类型林下苔藓层储水量均高于林下枯落物储水量,而林下地被物储水量随时间变化过程与森林类型无关。