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71.
Cadmium is a non-essential metal with a wide distribution that has severe toxic effects on aquatic animals. Changes in hematology and muscle physiology were examined in silver carp (Hypophthalmichthys molitrix) exposed to environmentally relevant levels of cadmium (0.01 mg L-1 ) for 96 h. Cadmium exposure induced significant increases in the red blood cell count, and in the plasma concentrations of cortisol, glucose, and lactate. This suggests that the dose of cadmium was sufficient to cause stress, possibly associated with impaired gas exchange at the gills. There were no changes in hemoglobin concentration or plasma protein concentration. Significant decreases in muscle energy fuels (ATP and glycogen), and increases in muscle lactate persisted until the end of the exposure period, respectively. The changes in muscle lactate and protein in silver carp differed from those observed in response to exposure of fish to cadmium and heavy metals in other studies. The study highlights the importance of selecting unpolluted release sites with suitable water conditions for the survival of newly released individuals for stock enhancement of the Xiangjiang River.  相似文献   
72.
Although previous studies showed that the principal oncoprotein encoded by Epstein-Barr virus, latentmembrane protein 1 (LMP1) 5 could induce the nasopharyngeal carcinoma cells in G_2/M phase increased, littleis known about the target molecules and mechanisms. The present study demonstrated that LMP1 couldinduce the accumulation of p53 protein and upregulate its transactivity in a dose dependent manner, whichresulted in the decrease of the kinase activity of cdc2/cyclin B complex and inducing arrest at G2/M phasethrough the activation of NF-κB and AP-1 signaling pathways, and the effect of NF-κB was more obviousthan that of AP-1. This study provided some significant evidence for further elucidating the molecularmechanisms that LMP1 had effects on the surveillance mechanism of cell cycle and promoting the survivalof transformed cells and tumorigenesis.  相似文献   
73.
莴苣花药发育过程中钙的分布特征   总被引:1,自引:0,他引:1  
减数分裂前,莴苣花药中的钙颗粒很少。减数分裂后,花药绒毡层细胞中的钙颗粒明显增加, 同时在花药药室基质中也出现许多细小的钙颗粒。刚从四分体中释放出的小孢子内钙颗粒很少,伴随着花粉外壁物质在小孢子表面的沉积,钙颗粒开始积累在花粉壁部位。随后,小孢子中开始出现钙颗粒。当小孢子开始形成液泡后,钙颗粒向其中聚集,伴随着小液泡融合成大液泡,体积较大的钙颗粒主要集中在液泡中,而细胞质基质中的钙颗粒很少。随着二胞花粉中的大液泡消失,花粉细胞质中的钙颗粒变得很少。在以后的发育中,只有花粉壁中积累较多的钙颗粒。在莴苣花药发育过程中,钙与绒毡层细胞的退化和小孢子液泡形成以及二胞花粉中大波泡的消失有关。而花粉外壁表面积累丰富的钙与以后花粉的萌发有关。  相似文献   
74.
湖南鸭鹅寄生吸虫的记述(吸虫纲:复殖目)   总被引:3,自引:0,他引:3  
  相似文献   
75.
Peroxiredoxin V(Prx V)是过氧化物酶peroxiredoxins家族中的一员,在神经细胞中含量丰富,具有通过清除细胞内活性氧(reactive oxygen species,ROS)和过氧亚硝酸盐抑制氧化应激诱导的细胞凋亡的作用。过量的一氧化氮(nitric oxide,NO)具有较强的神经毒性,可引起小胶质细胞炎性反应,诱导神经细胞凋亡从而引发神经退行性疾病,而且可诱导神经小胶质细胞Prx V的表达,参与小胶质细胞的活性调控过程。但是,NO诱导的海马神经细胞凋亡过程中Prx V的作用尚不清楚。该研究利用硝普化钠(sodium nitroprusside dihydrate,SNP)作为NO供体,检测了NO诱导的HT22小鼠海马神经细胞的凋亡及对Prx V蛋白表达的影响。结果显示,SNP诱导的HT22细胞凋亡呈现时间、浓度依赖性;并特异性地抑制了Prx V的表达,致使细胞内ROS水平升高,激活线粒体依赖的经典凋亡途径,导致HT22细胞的凋亡。该研究结果揭示,NO通过抑制细胞内Prx V的表达导致细胞内ROS水平升高,最终诱导HT22细胞发生凋亡的机制,为保护NO诱导的神经细胞凋亡提供了新的理论依据。  相似文献   
76.
以南荻幼穗为外植体,进行了组织培养与快速繁殖技术的研究。结果表明:最佳诱导培养基:MS+2.0mg·L-12,4-D+0.1mg·L-16-BA+0.5g·L-1水解酪蛋白+0.5g·L-1脯氨酸;最佳分化培养基:MS+0.5mg·L-1NAA+0.5mg·L-1KT+0.5mg·L-1IAA+2.0mg·L-16-BA+0.5g·L-1水解酪蛋白+0.5g·L-1脯氨酸;最佳生根培养基:MS+1.0mg·L-1NAA+0.25mg·L-1Met。炼苗后,移入营养土与珍珠岩(1:1)的基质中,移栽成活率高达100%。该体系的建立为南荻规模化生产及遗传改良提供了前提条件。  相似文献   
77.
以尾巨桉优良无性系无菌苗茎段为外植体,通过对噻唑基脲类新型分裂素(N-phenyl-N′-[6-(2-chlorobenzothiazol)-yl]urea,PBU)等多种不同浓度生长调节剂组合的优化,进行胚性愈伤组织诱导及植株再生研究。结果表明,在添加了2mg·L^-1PBU和0.05mg·L^-1IAA的改良MS培养基上,茎段外植体培养5d后愈伤组织诱导率达96%以上。将愈伤组织接种在添加1mg·L^-16-BA和0.05mg·L^-1NAA的MS培养基上,诱芽率达90.8%。随后在添加了0.8mg·L^-1PBU与0.05mg·L^-1IAA的1/2MS培养基上诱导芽伸长,用1/2MS培养基附加0.5mg·L^-1IBA诱导生根,移栽后得到完整再生植株。  相似文献   
78.
We report the fabrication of high performance organic solar cells by spray‐coating the photoactive layer in air. The photovoltaic blends consist of a blend of carbazole and benzothiadiazole based donor–acceptor copolymers and the fullerene derivative PC70BM. Here, we formulate a number of photovoltaic inks using a range of solvent systems that we show can all be deposited by spray casting. We use a range of techniques to characterize the structure of such films, and show that spray‐cast films have comparable surface roughness to spin‐cast films and that vertical stratification that occurs during film drying reduces the concentration of PCBM towards the underlying PEDOT:PSS interface. We also show that the active layer thickness and the drying kinetics can be tuned through control of the substrate temperature. High power conversion efficiencies of 4.3%, 4.5% and 4.6% were obtained for solar cells made from a blend of PC70BM with the carbazole‐based co‐polymers PCDTBT, P2 and P1. By applying a low temperature anneal after the deposition of the cathode, the efficiency of spray‐cast solar‐cells based on a P2:PC70BM blend is increased to 5.0%. Spray coating holds significant promise as a technique capable of fabricating large‐area, high performance organic solar cells in air.  相似文献   
79.
By homologous EST searching and nested PCR a new human gene GJB5 encoding gap junction protein p-5 was identified. GJB5 was genetically mapped to human chromosome 1p33-p35 by FISH. RT-PCR revealed that it was expressed in skin, placenta and fetal skin. DMA sequencing of GJB5 was carried out in 142 patients with sensorineural hearing impairment and probands of 36 families with genetic diseases, including erythrokeratodermia (5 families), Char-cot-Marie-Tooth disease (13), ptosis (4), and retinitis pigmentosa and deafness (14). Two mis-sense mutations (686A→G, H229R; 25C→T, L9F) were detected in two sensorineural hearing impairment families. A heterologous deletion of 18 bp within intron was found in 3 families with heredity hearing impairment, and in one of the 3 families, a missense mutation (R265P) was identified also. But the deletion and missense mutation seemed not segregating with hearing impairment in the family. No abnormal mRNA or mRNA expression was detected in deletion carriers by RT-PCR anal  相似文献   
80.
江西叶蜂一新属八新种(膜翅目)   总被引:1,自引:3,他引:1  
本文报道了采自江西省的叶蜂1新属8新种:其中牯岭叶蜂属Gulingia,gen.nov.隶属于平背叶蜂亚科Alantinae,并与北美的PhrotosomaMacGilivray近似,但后者唇舌不延长,颚眼距显著,前胸侧板腹面尖,中胸侧板平坦,前翅小脉交于第1盘室中部,后翅具封闭M室,后臀室柄长,触角窝距显著狭于内眶宽,触角第2节长大于宽等,与新属区别明显。文中报道的8个新种中,竹内牯岭叶蜂Gulingiatakeuchi,sp.nov.;脉黑元叶蜂Taxonusaterritina,sp.nov.和中华新盔叶蜂Neocorymbassinisca,sp.nov.仅分布于江西省,白胫前室叶蜂Alomorphanigromacula,sp.nov.分布于江西和浙江,黑眶前室叶蜂Alomorphanigriceps,sp.nov.分布于江西、浙江和福建,女贞宽腹叶蜂Macrophyaligustri,sp.nov.分布于江西和湖南,洼颜宽腹叶蜂Macrophyaplanatoides,sp.nov.分布于江西、湖南和广东  相似文献   
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