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1.
自2009年首次在湖南乌云界国家级自然保护区发现中华虎凤蝶种群以来,在该保护区持续开展了10余年的野外调查监测。通过对中华虎凤蝶湖南种群6个分布点的野外观测数据分析,结果表明中华虎凤蝶湖南种群栖息环境中的植被以禾本科、菊科、蔷薇科、百合科及豆科植物为主,共计有46科96属128种;不同栖息生境中种群数量差异较大,高山灌草丛为中华虎凤蝶湖南种群的主要生境,而梯田生境、乔木林生境中,其种群数量均很低,展现出与低矮芒草丛的保温遮阴特性以及寄主植物的分布密切相关。寄主植物的复壮和围栏的建设对中华虎凤蝶湖南种群的栖息环境起到了明显的保护作用、对其种群数量的增效作用显著。为深入研究中华虎凤蝶湖南种群的生物学和生态学特性提供了基础数据,为中华虎凤蝶湖南种群的保育工作开展奠定了理论基础,也为当地保护区的保护措施优化提供了科学依据。  相似文献   
2.
Scutellarin 7-O-β-d-glucuronide (scutellarin) has shown great potential as a chemotherapeutic agent for cancer treatment, but only at high dosage. Here we investigate the possibility of using low intensity ultrasound to reduce the scutellarin dosage. Ultrasound intensities of 1.0 W/cm2 and 0.05 W/cm2 were used for in vivo and in vitro experiments, respectively, and a very low dosage of scutellarin (15 nM) was used. Tumor-bearing Balb/c mice and SAS human-tongue squamous carcinoma cell suspensions were used for the in vivo and in vitro experiments, respectively. Each kind of subjects was divided into control, ultrasound-alone, scutellarin-alone, and combined ultrasound-scutellarin treatment groups. Only the combined treatment showed strong anticancer effects. In the in vivo case, the combined treatment significantly delayed tumor growth, initiated cellular chromatin changes (including a decrease in the number of cytoplasmic organelles and fragmentation of condensed nuclear chromatin), inhibited tumor angiogenesis and lymphangiogenesis, stopped cancer-cell proliferation, decreased MMP-2 and MMP-9 expression levels and caused cancer-cell apoptosis. In the in vitro case, the combined treatment produced cancer cell-shape irregularity in a manner seriously fractured microvilli, inhibited cancer-cell migratory and invasion activities, and induced cancer-cell apoptosis. Because the combined treatment did not increase intracellular ROS production, scutellarin is not a sonosensitizer so that the anticancer effect is not through sonodynamic therapy. Low-intensity ultrasound is merely increasing the permeability of scutellarin into cancer cells. Based on our results, one may perform localized chemotherapy using much reduced dosage of the drug with the help of low intensity ultrasound, which will greatly minimize side effects.  相似文献   
3.

Background

Gemcitabine and pemetrexed have been used as maintenance therapy. However, few systematic reviews and meta-analyses have assessed their effects in the newest studies. This systematic review and meta-analysis were conducted to assess the role of gemcitabine and pemetrexed in the maintenance treatment of non-small-cell lung carcinoma (NSCLC).

Methods

We performed a literature search using PubMed, EMBASE and Cochrane library databases from their inceptions to September 16, 2015. We also searched the American Society of Clinical Oncology (ASCO), European Society for Medical Oncology (ESMO), and National Comprehensive Cancer Network (NCCN) databases from 2008 to 2015. Two authors independently extracted the data. The Cochrane Collaboration’s risk of bias graph was used to assess the risk of bias. The GRADE system was used to assess the grading of evidence, and a meta-analysis was conducted using Stata 11.0 software.

Results

Eleven randomized controlled trial (RCT) studies were collected. Ten studies were included in the meta-analysis and divided into the following 4 groups: gemcitabine vs. best supportive care (BSC)/observation, pemetrexed vs. BSC/placebo, pemetrexed + bevacizumab vs. bevacizumab and pemetrexed vs. bevacizumab. Gemcitabine exhibited significantly improved progression-free survival (PFS) compared with BSC (hazard ratio (HR) = 0.62, p = 0.000). Pemetrexed exhibited significantly improved PFS (HR = 0.54, p = 0.000) and OS (HR = 0.75, p = 0.000) compared with BSC. Pemetrexed + bevacizumab almost exhibited significantly improved PFS (HR = 0.71, p = 0.051) compared with bevacizumab. Pemetrexed exhibited no improvement in PFS or overall survival (OS) compared with bevacizumab. Regarding the grade, the GRADE system indicated that the gemcitabine group was "MODERATE", the pemetrexed group was "HIGH", and both the pemetrexed + bevacizumab vs. bevacizumab groups and pemetrexed vs. B groups were "LOW".

Conclusions

Gemcitabine or pemetrexed compared with BSC/observation/placebo significantly improved PFS or OS. Whether pemetrexed + bevacizumab compared with bevacizumab alone significantly improves PFS requires further investigation.  相似文献   
4.
Papillary thyroid carcinoma (PTC) is the main type of thyroid carcinoma. Despite the good prognosis, some PTC patients may deteriorate into more aggressive diseases, leading to poor survival. Molecular technology has been increasingly used in the diagnosis and treatment of thyroid carcinoma. In this study, we identified that RNA Binding Motif Protein 47 (RBM47) was downregulated in PTC tissues and cells, and overexpression of RBM47 could activate autophagy and inhibit proliferation in PTC cells. RBM47 promotes but can not bind directly to Forkhead Box O3 (FOXO3). FOXO3 activates Autophagy Related Gene 3 (ATG3), ATG5, and RBM47 to form a loop and promote autophagy. RBM47 can bind directly to and stabilized lncRNA Small Nucleolar RNA Host Gene 5 (SNHG5) to inhibit PTC cells proliferation and activate autophagy in vitro and in vivo. SNHG5 inhibits ubiquitination and degradation of FOXO3 by recruiting Ubiquitin Specific Peptidase 21 (USP21), then promotes the translocation of FOXO3 from cytoplasm to nucleus. Our study revealed the regulatory mechanism of RBM47/SNHG5/FOXO3 axis on cell proliferation and autophagy in PTC, which may provide valuable insight for the treatment of PTC.Subject terms: Oncogenes, Head and neck cancer  相似文献   
5.
This study aims to figure out the methylation of long non-coding RNA GAS5 promoter in cervical cancer and the mechanism of GAS5 on the progression of cervical cancer cells. The expression of GAS5 and methylation state of GAS5 in cervical cancer tissues and cells were determined. With the aim to to explore the ability of GAS5 in the proliferation, cell cycle progression, apoptosis, invasion, migration as well as the tumor growth, and metastasis in nude mice were determined. The expression of GAS5 was decreased and methylation state of GAS5 was elevated in cervical cancer. Overexpression of GAS5 inhibited proliferation, cell cycle progression, invasion, migration while inducing apoptosis of cervical cancer cells as well as suppressed tumor growth and metastasis in nude mice. Our study demonstrates that abnormal methylation of GAS5 contributes to poor expression of GAS5 in cervical cancer. In addition, upregulation of GAS5 inhibits the cervical cancer development.  相似文献   
6.
Vinculin localizes to membrane adhesion junctions where it links actin filaments to the extracellular matrix by binding to the integrin-binding protein talin at its head domain (Vh) and to actin filaments at its tail domain (Vt). Vinculin can assume an inactive (closed) conformation in which Vh and Vt bind to each other, masking the binding sites for actin and talin, and an active (open) conformation in which the binding sites for talin and actin are exposed. We hypothesized that the contractile activation of smooth muscle tissues might regulate the activation of vinculin and thereby contribute to the regulation of contractile tension. Stimulation of tracheal smooth muscle tissues with acetylcholine (ACh) induced the recruitment of vinculin to cell membrane and its interaction with talin and increased the phosphorylation of membrane-localized vinculin at the C-terminal Tyr-1065. Expression of recombinant vinculin head domain peptide (Vh) in smooth muscle tissues, but not the talin-binding deficient mutant head domain, VhA50I, inhibited the ACh-induced recruitment of endogenous vinculin to the membrane and the interaction of vinculin with talin and also inhibited vinculin phosphorylation. Expression of Vh peptide also inhibited ACh-induced smooth muscle contraction and inhibited ACh-induced actin polymerization; however, it did not affect myosin light chain phosphorylation, which is necessary for cross-bridge cycling. Inactivation of RhoA inhibited vinculin activation in response to ACh. We conclude that ACh stimulation regulates vinculin activation in tracheal smooth muscle via RhoA and that vinculin activation contributes to the regulation of active tension by facilitating connections between actin filaments and talin-integrin adhesion complexes and by mediating the initiation of actin polymerization.  相似文献   
7.
生态资产核算与生态系统服务评估:概念交汇与重点方向   总被引:6,自引:0,他引:6  
刘焱序  傅伯杰  赵文武  王帅 《生态学报》2018,38(23):8267-8276
面向“山水林田湖草”统一管理的现实目标,对生态资产的准确刻画加深了资源管理者和使用者对生态系统服务的认识,是生态系统服务理论从学术研讨向决策实践过渡的重要桥梁。然而,当前的生态资产核算结果仍存在着较大的不确定性,使其决策支持作用受到质疑。基于对生态资产研究近今进展的总结,生态资产实际核算一般取自然资本与生态系统服务的交集分别作为存量和流量。如若将生态资产作为干部离任审计依据,则须把握先实物量后价值量的原则。在当前国际研究中,生态资产已经成为区域景观管理和农户生计决策的重要绩效评估与情景优选工具。完善生态系统服务评估模型、明晰生态系统服务供需关系、规范生态资产价值核算方法、提升生态资产决策支持能力4项内容应引起未来生态资产研究的重点关注。  相似文献   
8.
Sun  Weifeng  Wu  Yuanming  Ding  Wenwu  Wang  Li  Wu  Lunjie  Lin  Lu  Che  Zhenming  Zhu  Longbao  Liu  Yi  Chen  Xiaohua 《Bioprocess and biosystems engineering》2020,43(4):701-710
Bioprocess and Biosystems Engineering - Currently, some cases about the expression of flavor peptides with microorganisms were reported owing to the obvious advantages of biological expression over...  相似文献   
9.
王涵  赵文武  尹彩春 《生态学报》2023,43(6):2159-2170
在气候变化、人类活动等影响下,生态系统结构和功能可能发生大规模的突变,导致生态系统从一个相对稳定的状态进入另一个稳定状态,这种现象称为稳态转换。由于生态系统的复杂性,准确刻画生态系统多稳态并界定其临界点尚存在挑战,提升对生态系统稳态转换的检测和预测能力依旧是生态学领域研究的热点和难题。基于多稳态理论和稳态转换经典概念框架,阐释了稳态转换检测的理论基础;归纳总结出四种稳态转换检测方法的原理和优劣势;鉴于稳态转换的尺度依赖性,梳理了单一生态系统、区域综合生态系统和全球生态系统不同尺度下的稳态转换检测方法、研究思路和应用案例。基于研究进展和问题现状,提出在未来研究中,亟待发展适应复杂系统的综合检测方法;创新稳态转换多尺度分析的技术方法体系;深化生态系统稳态转换驱动机制研究,构建多元耦合机理模型;进而深化稳态转换检测结果链接生态系统管理的实践研究;解析生态系统服务和可持续发展机制。  相似文献   
10.
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