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31.
The primary objective of this study was to construct an immune-related long noncoding RNAs (IRLs) classifier to precisely predict the prognosis and immunotherapy response of patients with thymic epithelial tumors (TET). Based on univariable Cox regression analysis and Lasso regression, six prognosis-related IRLs (AC004466.3, , AC138207.2, AC148477.2, HOXB-AS1 and SNHG8) were selected to build an IRL classifier. Importantly, results of qRT-PCR validated that higher expression levels of AL450270.1, AC138207.2, AC148477.2 and SNHG8 as well as lower expression levels of AC004466.3, and HOXB-AS1 in TETs samples compared with normal controls. The IRL classifier could effectively classify patients into the low-risk and high-risk groups based on the different survival parameters. In terms of predictive ability and clinical utility, the IRL classifier was superior to Masaoka staging system. Additionally, IRL classifier is significantly associated with immune cells infiltration (dendritic cells, activated CD4 memory T cells and tumor-infiltrating lymphocyte (TIL), T cell subsets in particular), immune microenvironment (immune score and immune checkpoint inhibitors) and immunogenicity (TMB) in TETs, which hints that IRL classifier is tightly correlated with immune characteristics and might guide more effective immunotherapy strategies for TETs patients. Encouragingly, according to TIDE algorithm, there were more immunotherapy responders in the low-risk IRL subgroup and the IRL score was robustly negatively linked to the immunotherapeutic response. To sum up, the IRL classifier was established, which can be used to predict the prognosis, immune infiltration status, immunotherapy response in TETs patients, and may facilitate personalized counseling for immunotherapy. AL450270.1相似文献
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潮棕壤线虫群落对土地利用方式的响应 总被引:4,自引:0,他引:4
作者对潮棕壤不同土地利用方式(旱田、撂荒地和林地)下土壤线虫群落时空分布特征进行了研究, 结果表明, 不同土地利用方式能够影响线虫群落及其优势属的时空分布。线虫优势属对不同土地利用方式的响应不同, 撂荒地和林地处理中板唇属(Chiloplacus)线虫主要分布在5–30 cm土层, 而其他线虫优势属则主要分布在0–20 cm土层; 在旱田处理中, 短体属(Pratylenchus)线虫均匀分布在各个土层。由于土地利用方式的改变而引起的土壤环境因素的变化能够对土壤线虫产生影响, 研究发现土壤孔隙度、土壤有机碳、全氮和碳氮比与土壤线虫优势属的数量具有显著的正相关关系。线虫区系分析结果表明, 撂荒地和林地处理中土壤环境相对稳定, 土壤食物网向较成熟的阶段演替。线虫区系分析方法可用来揭示不同土地利用方式下土壤食物网的变化, 为进一步研究土壤生态过程对土地利用方式的响应提供了有效的工具。 相似文献
34.
摘要:【目的】分析蓝细菌病毒A-4L在鱼腥藻(Anabaena sp.) PCC 7120藻苔中形成同心圆噬斑的原因,阐明A-4L的一个重要生物学特征,为分离、鉴定和筛选新的水华蓝藻病毒提供借鉴。【方法】用初始滴度为2.8×1010PFU/mL的A-4L悬液感染鱼腥藻,在不同时间点收集裂解液绘制一步生长曲线,获得A-4L对鱼腥藻的潜伏期和释放量。将适量A-4L悬液感染不同培养时间的藻苔,逐日观察和记录藻苔病变情况。培养藻苔并接种适量A-4L悬液,分别置于完全持续光照(Light:Dark=24 h:0 h,L:D=24 h:0 h)条件;完全周期光照(L:D=14 h:10h)条件;或前3 d周期光照转后3 d持续光照的条件下,比较不同光照条件对同心圆噬斑形成的影响。然后挑取单个噬斑进行扩大培养,纯化后,负染电镜观察A-4L的超微形态。【结果】A-4L的潜伏期为0.5-2h,释放量约为247 IU/cell (Infectious Units)。在周期光照条件下,藻苔接种A-4L 3-4 d后,出现同心圆噬斑,且同心圆数量与攻毒后的天数(n)有相关性,为“n-1”;同心圆间距约为3 mm。与周期光照条件相比,在持续光照条件下未形成同心圆噬斑。而在周期光照条件转持续光照条件下,由先周期光照时所形成的同心圆在转持续光照后逐渐消失,证实同心圆噬斑的形成依赖于周期光照。负染电镜观察显示A-4L具有一个近似球形的头部,直径约为50 nm以及长度约为10 nm的尾部,形态与短尾蓝细菌病毒相似。【结论】A-4L是一株能形成同心圆噬斑的蓝细菌病毒,并揭示其同心圆噬斑形成的关键条件是周期光照。 相似文献
35.
Mechanism of high susceptibility of iron-overloaded mouse to Vibrio vulnificus infection 总被引:2,自引:0,他引:2
Vibrio vulnificus produces fulminant septicemia in humans with underlying conditions, particularly those with diseases that elevate the iron level. The effect of a high iron level on the virulence of V. vulnificus was therefore investigated in mice treated with iron dextran. The mice loaded with iron became highly susceptible to V. vulnificus infection, the LD50 (50% lethal dose) decreased five logs when infected per peritoneum. However, when infected via the oral route, the LD50 was affected little unless the mouse was treated with an additional drug such as cyclophosphamide or D-galactosamine. Mice with or without iron-overloading died when the bacterial concentration in the blood reached 10(5) cfu/ml or above. Iron increased the growth rate of the bacteria, both inside and outside of the animal, quickly reaching a lethal concentration in the iron-overloaded mouse. V. vulnificus, grown with or without the addition of iron, showed strong cytotoxicity on the isolated cells or within the animal at high bacterial concentration. Iron overload stimulated the production of tumor necrosis factor alpha (TNF-alpha), a major factor of septic shock, in mice upon infection with the bacteria, probably caused by the endotoxin; however, the neutrophils, whose migration is effected by TNF-alpha, appeared to be less active. Taken together, the major virulence factor of V. vulnificus appeared to be the accelerated growth of bacteria to quickly reach the lethal level and the lower activity of immune cells including neutrophil as a result of iron-overloading. These two effects manifest other virulence factors, the host's as well as bacterial. Such factors, other than TNF-alpha stimulated by the endotoxin, enhanced cytotoxicity, which kills the host cells including the host's immune cells. 相似文献
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云南省香格里拉大峡谷藏族神山在自然保护中的意义 总被引:11,自引:1,他引:11
位于云南省西北部迪庆藏族自治州境内的香格里拉大峡谷拥有独特的自然人文景观和丰富的生物多样性。藏族作为当地最重要的原住民族,他们的文化对当地的自然环境具有重要的影响。为了解藏族传统文化中的神山崇拜对香格里拉大峡谷地区自然环境的影响,本文应用民族生态学、植物生态学和文化人类学的研究方法,结合文献资料的分析,对香格里拉大峡谷的藏族神山进行了调查和研究,并对处于不同保护状态下(神山与非神山)的两个典型植物群落即高山松(Pinus densata)群落和云南黄果冷杉(Abies ernestii var. salouenensis)群落进行了比较。结果显示,在相同的样地面积内(20 m×20 m),神山植物群落在物种数量(20,14)和群落盖度(100%,85%)方面都明显高于非神山植物群落(11,2;70%,60%)。结合入户调查资料,发现广泛分布于香格里拉大峡谷的藏族神山构成了一个“自下而上”的乡土保护体系,它不仅在保护生物多样性、维护当地脆弱的生态环境等方面发挥着重要的作用,而且还可以提供多种非林产品,实现多种生态功能。文章探讨了发挥乡土保护体系的保护功效及应用传统文化知识以促进自然保护的重要性,建议应当尊重和保护原住民的传统文化,发掘其中优秀的自然保护知识和经验,引导其发挥更加有效的自然保护功能,使民族传统保护体系成为现代自然保护体系的有力补充。 相似文献
38.
危害健康松属植物的小蠹虫经常与一些特殊的真菌相联系.在小蠹虫危害松属植物的过程中,这些真菌被小蠹虫的一些特殊结构或者体表携带到松属植物上.小蠹虫与其伴生菌的联系表明小蠹虫和其伴生菌之间是一种互惠互利的关系.伴生菌随小蠹虫扩散而被带到新的寄主树木.而伴生菌或作为小蠹虫的食物来源,但更重要的是,有些伴生菌能够通过其菌丝渗透寄主组织,释放毒素,致死寄主树木,以帮助小蠹虫降低寄主抗性.许多研究致力于探索小蠹虫/伴生菌联合体与寄主树木之间关系的特征和确定小蠹虫与其伴生菌相互关系在生态学上的意义.然而,不同小蠹虫和其伴生菌所组成的共生体系,不同小蠹虫的种群数量,和不同环境条件下同种小蠹虫与其伴生菌相互作用方式的差异使我们在研究小蠹虫和其伴生菌这个共生体系时,对它们各自在成功聚集寄主树木过程中所发挥的重要作用的概括变得非常困难. 相似文献
39.
Cheng-Jun He Cheng Peng Xiao-Fang Xie Li Guo Qin-Mei Zhou Xiao-Hong Li Ou Dai Zhao Geng Yi-Ping Guo 《Phytochemistry letters》2013,6(2):299-301
Two new dianthramide glucosides, N-(2′-β-d-glucopyranosyl-5′-hydroxysalicyl)-4-hydroxy-3-methoxyanthranilic acid methyl ester (1) and N-(2′-β-d-glucopyranosyl-5′-hydroxysalicyl)-4-hydroxyanthranilic acid methyl ester (2), together with five known glycosides, were isolated from the lateral roots of Aconitum carmichaelii. Their structures were elucidated by spectroscopic analyses. In the in vitro assays, compounds 1 and 2 showed activity against pentobarbital sodium-induced cardiomyocytes damage by recovering beating rhythm and increasing the cell viability. 相似文献
40.
Cindy Q. Tang Mei-Hua Zhao Xiao-Shuang Li Masahiko Ohsawa Xiao-Kun Ou 《Ecological Research》2010,25(1):149-161
Since 1985, originally forested mountainous areas of China have been allowed to return to their natural state after years
of exploitation including agriculture, development, and logging. The reforms began earlier in less accessible locations, so
that today the successional process is more advanced there. The vegetation in Luquan, Qiongzhusi, and Xishan near Kunming,
central Yunnan, exhibits, in a limited area, a range of stages of plant succession that are widely encountered throughout
the broader region, and thus affords a special opportunity for a comprehensive study. We analyzed the successional sequence
of these various plant communities. They ranged from pioneer coniferous and/or pioneer deciduous broad-leaved stands to pre-mature
semi-humid evergreen broad-leaved stands, through mixed coniferous and broad-leaved or mixed deciduous and evergreen broad-leaved
stands. The succession proceeded from pioneer coniferous Pinus and Keteleeria, and deciduous Platycarya and Alnus, to late-successional evergreen broad-leaved Cyclobalanopsis and Castanopsis. Two regeneration types of woody species in either the early successional (15–50 years), the mid-successional (40–80 years),
or the late-successional (80–180 years) stage were classified. Relatively high species diversity was found in the seral phase
at the three study sites. The late-successional stage was commonest where human disturbance was least evident. Poor soil chemical
properties under pioneer Pinus were seen as a limitation to plant growth, while the abundance of Alnus at the early stage led to an improved level of organic matter and nitrogen. 相似文献