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991.
Qiuxin Wu Dadong Guo Hongsheng Bi Daoguang Wang Yuxiang Du 《Molecular and cellular biochemistry》2013,382(1-2):263-272
Ultraviolet B (UVB) could lead to the apoptosis of human lens epithelial cell and be hypothesized to be one of the important factors of cataractogenesis. In the human lens, Ca2+-ATPase is a major determinant of calcium homeostasis. Plasma membrane calcium ATPase1 (PMCA1) is a putative “housekeeping” isoform and is widely expressed in all tissues and cells, which plays an important role in calcium homeostasis. However, the effects of UVB-irradiation on the expression of PMCA1 and the cellular calcium homeostasis are still unclear. In the present study, we cultured human lens epithelial cells (HLE B-3) in vitro and investigated the effects of UVB irradiation on the expression of PMCA1 and the intracellular calcium homeostasis using real-time cell electronic sensing system, flow cytometry, fluo-3/AM probes, real-time quantitative PCR, and enzyme-linked immunosorbent assay techniques. We found that UVB irradiation could induce human lens epithelial cell death, cause intracellular calcium ion (Ca2+) elevation, inhibit Ca2+-ATPase activity and decrease the expression of PMCA1 at gene and protein levels, suggesting that the downregulation of PMCA1 and the disruption of calcium homeostasis may play important roles in UVB-induced HLE B-3 cell apoptosis. 相似文献
992.
993.
运用主分量分析法对霍山东、西两坡的105个样方进行了排序。前3个主分量占总信息量的70%左右。降维效果良好。排序图中,样方间距离抽象地表达了群落间的生态学相关程度。据此将所作样方划分为若干群系,分析了群落随环境梯度变化的规律、观测了群落演替的趋向。从而证明PCA法在该区森林群落研究中具有良好的适应性。 相似文献
994.
995.
Peng Zheng Jieyu Ge Jiayi Ji Jingling Zhong Hongyu Chen Daren Luo Wei Li Bo Bi Yongjun Ma Wanghui Tong Leiqin Han Siqi Ma Yuqi Zhang Jianping Wu Yanqiu Zhao Ronghui Pan Pengxiang Fan Mengzhu Lu Hao Du 《Plant biotechnology journal》2023,21(8):1671-1681
The fungal bioluminescence pathway (FBP) was identified from glowing fungi, which releases self-sustained visible green luminescence. However, weak bioluminescence limits the potential application of the bioluminescence system. Here, we screened and characterized a C3′H1 (4-coumaroyl shikimate/quinate 3′-hydroxylase) gene from Brassica napus, which efficiently converts p-coumaroyl shikimate to caffeic acid and hispidin. Simultaneous expression of BnC3′H1 and NPGA (null-pigment mutant in A. nidulans) produces more caffeic acid and hispidin as the natural precursor of luciferin and significantly intensifies the original fungal bioluminescence pathway (oFBP). Thus, we successfully created enhanced FBP (eFBP) plants emitting 3 × 1011 photons/min/cm2, sufficient to illuminate its surroundings and visualize words clearly in the dark. The glowing plants provide sustainable and bio-renewable illumination for the naked eyes, and manifest distinct responses to diverse environmental conditions via caffeic acid biosynthesis pathway. Importantly, we revealed that the biosynthesis of caffeic acid and hispidin in eFBP plants derived from the sugar pathway, and the inhibitors of the energy production system significantly reduced the luminescence signal rapidly from eFBP plants, suggesting that the FBP system coupled with the luciferin metabolic flux functions in an energy-driven way. These findings lay the groundwork for genetically creating stronger eFBP plants and developing more powerful biological tools with the FBP system. 相似文献
996.
997.
Central neuropathogenesis of vesicular stomatitis virus infection of immunodeficient mice. 总被引:4,自引:3,他引:1
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To determine whether central neuropathogenesis associated with vesicular stomatitis virus (VSV) infection is regulated by T cells, we have examined the effects of intranasal infection of mice lacking T cells. The mice examined were of two kinds: (i) thymus-deficient BALB/c nu/nu nice and (ii) BALB/c mice experimentally depleted of T cells by systemic infusions of a monoclonal antibody to the CD4 or CD8 cell surface molecules. These mice were infected intranasally with a single dose of replication-competent VSV. Brain tissue homogenates were analyzed for the presence of infectious virus. For each population of mice, infection-related mortality was assessed. In histological sections of brain, the distribution of viral antigens (Ags) was examined by immunocytochemistry. We found that recovery of infectious virus from homogenates of tissues obtained from athymic nu/nu animals was more than 10 times greater than that from samples from their euthymic littermates. With a single exception in a BALB/c nu/nu mouse, virus was not isolated from the spleen when it was administered intranasally. In these experimental infections, athymic mice succumbed 1 to 2 days before their euthymic littermates. A dose of virus that resulted in half of the nu/+ survival rate was uniformly lethal to nu/nu mice. In experiments with BALB/c mice depleted of either CD4+ or CD8+ T cells by in vivo antibody treatment, histological analysis revealed an increase in viral Ag distribution in comparison with control (medium-infused) infected mice. Necrosis and inflammation paralleled the extent of viral Ag expression. Viral Ags were detected in discrete areas that usually remain uninfected in immunocompetent mice. These areas include the neocortex and caudate putamen nuclei, the piriform cortex, and the lateral olfactory tract. Neuronal loss and necrosis were consistently found in the olfactory bulb and the horizontal/vertical band of Broca. In some of the T-cell depleted mice, necrosis was also evident in the hippocampus, fimbria, mammillary bodies, and hypothalamic nuclei. In the brain stem, perivascular cuffing was evident, but with little necrosis. Collectively, these data suggest that CD4+ and CD8+ T cells make only a minor contribution to the development of histopathology but rather function together to limit viral replication and transsynaptic or ventricular spread of virus, thus promoting recovery. The primary effectors of histopathology appear to be related more to the cytopathologic nature of the virus infection and non-T-cell-mediated mechanisms. 相似文献
998.
报道了新拟除虫菊酯PY115-α-(氰基-2-甲基-戊-2-烯基)-2,2-二甲基-3-(2,2-二氯乙烯基)-环丙烷羧酸酯及其立体异构体的杀虫选择性。PY115对库蚊的触杀、薰蒸作用明显高于甲醚菊酯、低于右旋丙烯菊酯。PY115的反体杀虫活性高于顺体;反体的两对外消旋体的杀虫活性亦具有明显的特异性,β体大于α体。 相似文献
999.
从19世纪到建国之前西方国家对我国进行的植物资源调查 总被引:8,自引:0,他引:8
世界上任何一个国家,在历史进程达到了某一时期时,总免不了要和别的国家进行文化科学的交往。我国远在汉代,甚至更早,就有了这样的交往。到了16—18世纪,即明代后期和清代前期,西方的许多国家中的许多人,不断地来到我国,从事各种科学文 相似文献
1000.
板栗干腐病研究:Ⅱ.症状及病原 总被引:4,自引:0,他引:4
对板栗干腐病症状及病原的研究结果表明:1.板栗干腐病主要发生于种仁上,其病斑大小、质地不一。按色泽可分为褐、黑、白、灰、黄五类。果实其它部位也偶有症状产生;2.此病为多种真菌复合侵染所致。主要的致病菌有Phoma、Phomopsis、Dothiorella、Gloeosporium和Cytospora等属真菌,另有十余种弱寄生及腐生菌有时也混合发生。 相似文献