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91.
92.
A facile and binder‐free method is developed for the in situ and horizontal growth of ultrathin mesoporous Co3O4 layers on the surface of carbon fibers in the carbon cloth (ultrathin Co3O4/CC) as high‐performance air electrode for the flexible Zn–air battery. In particular, the ultrathin Co3O4 layers have a maximum contact area on the conductive support, facilitating the rapid electron transport and preventing the aggregation of ultrathin layers. The ultrathin feature of Co3O4 layers is characterized by the transmission electron microscopy, Raman spectra, and X‐ray absorption fine structure spectroscopy. Benefiting from the high utilization degree of active materials and rapid charge transport, the mass activity for oxygen reduction and evolution reactions of the ultrathin Co3O4/CC electrode is more than 10 times higher than that of the carbon cloth loaded with commercial Co3O4 nanoparticles. Compared to the commercial Co3O4/CC electrode, the flexible Zn–air battery using ultrathin Co3O4/CC electrode exhibits excellent rechargeable performance and high mechanical stability. Furthermore, the flexible Zn–air battery is integrated with a flexible display unit. The whole integrated device can operate without obvious performance degradation under serious deformation and even during the cutting process, which makes it highly promising for wearable and roll‐up optoelectronics.  相似文献   
93.
皖西霍山县白马尖植物区系和植被   总被引:4,自引:0,他引:4       下载免费PDF全文
本文论述了北亚热带典型地段——大别山主峰白马尖的植被和植物区系的特点,提出白马尖地区是一“生物避难所”。与纬度相近地区的比较研究,结果表明,海拔1000米以上的山地,植被类型和植物区系成份与皖南黄山、浙北天目山较一致,而低海拔地区与江苏的宜溧山区相似,特别是常绿阔叶树的属、种极为一致。值得指出的是耐寒常绿阔叶林类型的发现,为北亚热带植被地带的概念增添了新内容。文中对原圈定佛子岭水库库区周围为水源涵养林自然保护区认为不妥,将白马尖主峰整个集水区包括在内,才是完善的。  相似文献   
94.
藕莲有性繁殖栽培   总被引:2,自引:0,他引:2  
根据莲(Nelumbo nucifera)生物学特性,既可用藕作种进行无性繁殖,也可用种子播种进行有性繁殖。藕莲在我国有数千年的栽培历史,但素以无性系栽培。尚未见到有性繁殖栽培的报道。作者自1980年起进行了有性繁殖栽培试验。    相似文献   
95.
One new ent‐kaurane diterpenoid, 11β,16α‐dihydroxy‐ent‐kauran‐19‐oic acid ( 1 ), together with eight known analogues 2 – 9 were isolated from the aerial parts of Wedelia prostrata. One of the acidic diterpenoids, kaurenoic acid ( 3 ), was converted to seven derivatives, 10 – 16 . All compounds were evaluated for their cytotoxic activity in vitro against human leukemia (K562), liver (HepG‐2), and stomach (SGC‐7901) cancer cell lines. Only four kaurenoic acid derivatives, 13 – 16 , with 15‐keto and substitutions at C(19) position, exhibited notable cytotoxic activities on these tumor cell lines with IC50 value ranging from 0.05 to 3.71 μm . Compounds 10 – 12 , with oxime on C(15) showed moderate inhibitory effects and compounds 1 – 9 showed no cytotoxicities on them. Structure–activity relationships were also discussed based on the experimental data obtained. The known derivative, 15‐oxokaurenoic acid 4‐piperdin‐1‐ylbutyl ester ( 17 ), induced typical apoptotic cell death in colon SW480 cells upon evaluation of the apoptosis‐inducing activity by flow‐cytometric analysis.  相似文献   
96.
2008年至2009年间,在湖南和湖北两省的活禽市场中分离到了14株H6亚型禽流感病毒,为了解这14株病毒之间的分子特征和差异,我们运用PCR和测序鉴定对这14株病毒的NA基因进行了分型,并对其表面基因HA和NA进行序列测定及序列分析.14株H6亚型病毒中,H6N2亚型12株,H6N6亚型2株.序列测定和进化分析结果显示:DK/HN/284的HA基因与其它13株的HA差异性较大,差异性达到19.4%~20.2%,其余13株毒同源性在94.2%~99.9%;N2亚型NA基因的同源性在91.1%~99.9%,差异性比较大;两株N6亚型NA基因同源性为89.5%,差异明显.这些数据表明:不同毒株呈现一定的地域性差异.与我国周边其它地区的H6亚型禽流感毒株序列进行比较发现,只有DK/HN/284的HA基因与香港早期的毒株可能有着共同的来源,其余都与香港和韩国等的毒株有着较大的差异性,并且各个毒株的HA基因上潜在的糖基化位点和受体结合位点也有所不同,这些数据表明,这些毒株表现出明显的异源性.  相似文献   
97.
本研究以总黄酮吸附量和解析率为检测指标,结合动态洗脱考察结果,考察11种树脂对赶黄草总黄酮的富集精制能力。优化树脂类型,选定了对总黄酮进行富集纯化较好的树脂HPD450;采用单因素及正交实验,确定最佳工艺条件:上样量10 mL,以6 mL/min的流速8 BV水、6 BV 80%甲醇溶液洗脱,pH值为6~7。以此方法得到90%以上的赶黄草总黄酮,实验结果良好,总黄酮精制工艺成效显著。用HPLC法精确测定赶黄草中槲皮苷、PGHG和ThA三个指标性黄酮成分,最佳色谱条件为:C18色谱柱,检测波长280 nm,进样量5μL,流动相:乙腈-0.05%磷酸溶液(0~25 min:12%~45%乙腈;25~40 min:45%~70%乙腈)梯度洗脱;精确测定赶黄草全草中3种黄酮成分的含量。采用分光光度法检测,指导优化总黄酮精制工艺,并以HPLC法精确测定三种黄酮代表成分。比较两种方法测定结果相一致,互为补充;故在工业生产时,可以分光光度法指导生产,以HPLC法精确定量测定。  相似文献   
98.
Protein kinase D (PKD) has been implicated in many aspects of tumorigenesis and progression, and is an emerging molecular target for the development of anticancer therapy. Despite recent advancement in the development of potent and selective PKD small molecule inhibitors, the availability of in vivo active PKD inhibitors remains sparse. In this study, we describe the discovery of a novel PKD small molecule inhibitor, SD-208, from a targeted kinase inhibitor library screen, and the synthesis of a series of analogs to probe the structure-activity relationship (SAR) vs. PKD1. SD-208 displayed a narrow SAR profile, was an ATP-competitive pan-PKD inhibitor with low nanomolar potency and was cell active. Targeted inhibition of PKD by SD-208 resulted in potent inhibition of cell proliferation, an effect that could be reversed by overexpressed PKD1 or PKD3. SD-208 also blocked prostate cancer cell survival and invasion, and arrested cells in the G2/M phase of the cell cycle. Mechanistically, SD-208-induced G2/M arrest was accompanied by an increase in levels of p21 in DU145 and PC3 cells as well as elevated phosphorylation of Cdc2 and Cdc25C in DU145 cells. Most importantly, SD-208 given orally for 24 days significantly abrogated the growth of PC3 subcutaneous tumor xenografts in nude mice, which was accompanied by reduced proliferation and increased apoptosis and decreased expression of PKD biomarkers including survivin and Bcl-xL. Our study has identified SD-208 as a novel efficacious PKD small molecule inhibitor, demonstrating the therapeutic potential of targeted inhibition of PKD for prostate cancer treatment.  相似文献   
99.
Melanoma is an aggressive skin malignancy with a high mortality rate; however, successful treatment remains a clinical challenge. Ivermectin, a broad-spectrum antiparasitic drug, has recently been characterized as a potential anticancer agent due to its observed antitumor effects. However, the molecular mechanisms of ivermectin remain poorly understood. In the current study, we tested the involvement of autophagy in the ivermectin mechanism of action in human melanoma cells. We exposed SK-MEL-28 cells to different concentrations of ivermectin (2.5, 5, and 10 μM) for 24 hours. Here, ivermectin-induced apoptosis, as evidenced by the upregulation of cleaved poly (ADP-ribose) polymerase, BAX expression, and caspase-3 activity and downregulation of BCL-2 expression. In line with the apoptosis response, ivermectin triggered autophagy. Pharmacological or genetic inhibition of autophagy further sensitized SK-MEL-28 cells to ivermectin-induced apoptosis. Mechanistically, ivermectin-induced TFE3(Ser321) dephosphorylation, activated TFE3 nuclear translocation and increased TFE3 reporter activity, which contributed to lysosomal biogenesis and the expression of autophagy-related genes, and subsequently, initiated autophagy in SK-MEL-28 cells. Moreover, N-acetyl-cysteine, an reactive oxygen species (ROS) scavenger, abrogated the effects of ivermectin on TFE3-dependent autophagy. Taken together, we demonstrated that ivermectin increases TFE3-dependent autophagy through ROS signaling pathways in human melanoma cells and that inhibiting autophagy enhances ivermectin-induced apoptosis in human melanoma cells.  相似文献   
100.
凝胶层析在发酵液中分离提纯透明质酸中的应用   总被引:1,自引:0,他引:1  
采用葡聚糖凝胶G-100,以0.1 mol/L氯化钠溶液为洗脱剂,在优化的凝胶层析条件(层析柱高度30 cm、进样量2 ml、洗脱流速1 ml/4 min)下,对透明质酸发酵液进行分离纯化,得到了高纯度的透明质酸.HA提取率达到79.85%,蛋白质去除率为84.93%.  相似文献   
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