全文获取类型
收费全文 | 7494篇 |
免费 | 655篇 |
国内免费 | 1017篇 |
出版年
2024年 | 10篇 |
2023年 | 167篇 |
2022年 | 232篇 |
2021年 | 534篇 |
2020年 | 372篇 |
2019年 | 463篇 |
2018年 | 392篇 |
2017年 | 317篇 |
2016年 | 396篇 |
2015年 | 556篇 |
2014年 | 684篇 |
2013年 | 646篇 |
2012年 | 744篇 |
2011年 | 625篇 |
2010年 | 423篇 |
2009年 | 378篇 |
2008年 | 388篇 |
2007年 | 321篇 |
2006年 | 267篇 |
2005年 | 249篇 |
2004年 | 195篇 |
2003年 | 198篇 |
2002年 | 159篇 |
2001年 | 95篇 |
2000年 | 52篇 |
1999年 | 48篇 |
1998年 | 64篇 |
1997年 | 35篇 |
1996年 | 34篇 |
1995年 | 19篇 |
1994年 | 10篇 |
1993年 | 20篇 |
1992年 | 16篇 |
1991年 | 14篇 |
1990年 | 8篇 |
1989年 | 12篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1974年 | 1篇 |
1970年 | 1篇 |
1950年 | 2篇 |
排序方式: 共有9166条查询结果,搜索用时 15 毫秒
61.
Food restriction (FR) is hypothesized to decrease body fat content of an animal and thus prevent obesity. However, the response
of energy budget to a continuous (CFR) or discontinuous FR (DFR) remains inconsistent. In the present study, effects of CFR
or DFR and refeeding on energy budget and behavior were examined in male Swiss mice. CFR significantly decreased the energy
expenditure associated with basal metabolic rate (BMR) and activity behavior, but not sufficiently to compensate for energy
deficit and thus resulted in lower body mass and fat content. DFR mice had a significantly higher food intake on ad libitum
days and showed increases in BMR and activity after 4 weeks’ DFR, which might resulted in lower body mass and less body fat
than controls. After being refed ad libitum, both CFR and DFR mice had similar body mass, BMR, and behavioral patterns to
controls but had 95% and 75% higher fat content. This suggested that not only CFR but also DFR would be a significant factor
in the process of obesity for animals that were refed ad libitum. It also indicated that food restriction interrupted many
times by periods of ad libitum feeding had the same long-term effects like continuous underfeeding. 相似文献
62.
Kerstin Johannesson Zuzanna Zagrodzka Rui Faria Anja Marie Westram Roger K. Butlin 《Journal of evolutionary biology》2020,33(3):342-351
Genetic incompatibilities contribute to reproductive isolation between many diverging populations, but it is still unclear to what extent they play a role if divergence happens with gene flow. In contact zones between the "Crab" and "Wave" ecotypes of the snail Littorina saxatilis, divergent selection forms strong barriers to gene flow, while the role of post‐zygotic barriers due to selection against hybrids remains unclear. High embryo abortion rates in this species could indicate the presence of such barriers. Post‐zygotic barriers might include genetic incompatibilities (e.g. Dobzhansky–Muller incompatibilities) but also maladaptation, both expected to be most pronounced in contact zones. In addition, embryo abortion might reflect physiological stress on females and embryos independent of any genetic stress. We examined all embryos of >500 females sampled outside and inside contact zones of three populations in Sweden. Females' clutch size ranged from 0 to 1,011 embryos (mean 130 ± 123), and abortion rates varied between 0% and 100% (mean 12%). We described female genotypes by using a hybrid index based on hundreds of SNPs differentiated between ecotypes with which we characterized female genotypes. We also calculated female SNP heterozygosity and inversion karyotype. Clutch size did not vary with female hybrid index, and abortion rates were only weakly related to hybrid index in two sites but not at all in a third site. No additional variation in abortion rate was explained by female SNP heterozygosity, but increased female inversion heterozygosity added slightly to increased abortion. Our results show only weak and probably biologically insignificant post‐zygotic barriers contributing to ecotype divergence, and the high and variable abortion rates were marginally, if at all, explained by hybrid index of females. 相似文献
63.
64.
65.
本研究分别利用SSR标记、InDel标记以及简化基因组测序技术对一套以普通野生稻为供体亲本,9311为受体亲本的染色体置换系进行基因型鉴定,并通过对其不同生育期的耐盐性鉴定,共发掘2个与发芽期耐盐相关的QTL,13个与苗期耐盐性相关的QTL。其中与苗期存活率相关的QTL qSSR5.1、苗期耐盐等级相关的QTL qSSG5.1均被定位于同一位点,该位点对苗期存活率、苗期耐盐等级均具有增效作用,贡献率分别为6.36%、8.13%。在此QTL内包含与非生物胁迫相关基因OsDi19-1。经序列比对发现,OsDi19-1启动子区域在两亲本间存在较大差异,且受到盐胁迫时该基因表达量上升。同时,鉴定出水稻芽期耐盐的优异种质资源CSSL72、苗期耐盐的优异种质资源CSSL23、CSSL153,为水稻育种中耐盐性的改良提供了新的种质资源。 相似文献
66.
本文报道了产自斯里兰卡的干皮孔菌属一个新种,该种的主要特征是具有平伏反卷或具菌盖的子实体,很小的孔口(每毫米8-10个),菌丝系统二系,生殖菌丝覆盖有刺状结晶,骨架菌丝橙棕色,细腊肠状担孢子(2.7-3.4×0.5-0.8μm)。基于ITS和nLSU序列的系统发育分析表明该新种属于干皮孔菌属的一个明确的分支。此外,将毛孔菌属组合到干皮孔菌属中,并报道了3个组合种,白边干皮孔菌、印度干皮孔菌和萨彦干皮孔菌。 相似文献
67.
Xiaoli Hu Rui Li Yanqing Wu Yi Li Xingfeng Zhong Guanyinsheng Zhang Yanmin Kang Shuhua Liu Ling Xie Junming Ye Jian Xiao 《Journal of cellular and molecular medicine》2020,24(14):8166-8178
The application of growth factors (GFs) for treating chronic spinal cord injury (SCI) has been shown to promote axonal regeneration and functional recovery. However, direct administration of GFs is limited by their rapid degradation and dilution at the injured sites. Moreover, SCI recovery is a multifactorial process that requires multiple GFs to participate in tissue regeneration. Based on these facts, controlled delivery of multiple growth factors (GFs) to lesion areas is becoming an attractive strategy for repairing SCI. Presently, we developed a GFs‐based delivery system (called GFs‐HP) that consisted of basic fibroblast growth factor (bFGF), nerve growth factor (NGF) and heparin‐poloxamer (HP) hydrogel through self‐assembly mode. This GFs‐HP was a kind of thermosensitive hydrogel that was suitable for orthotopic administration in vivo. Meanwhile, a 3D porous structure of this hydrogel is commonly used to load large amounts of GFs. After single injection of GFs‐HP into the lesioned spinal cord, the sustained release of NGF and bFGF from HP could significantly improve neuronal survival, axon regeneration, reactive astrogliosis suppression and locomotor recovery, when compared with the treatment of free GFs or HP. Moreover, we also revealed that these neuroprotective and neuroregenerative effects of GFs‐HP were likely through activating the phosphatidylinositol 3 kinase and protein kinase B (PI3K/Akt) and mitogen‐activated protein kinase/extracellular signal‐regulated kinase (MAPK/ERK) signalling pathways. Overall, our work will provide an effective therapeutic strategy for SCI repair. 相似文献
68.
Mingjun Zheng Yuexin Hu Rui Gou Ouxuan Liu Xin Nie Xiao Li Qing Liu Yingying Hao Juanjuan Liu Bei Lin 《Journal of cellular and molecular medicine》2020,24(5):2819-2831
Ovarian carcinoma has the highest mortality among the malignant tumours in gynaecology, and new treatment strategies are urgently needed to improve the clinical status of ovarian carcinoma patients. The Cancer Genome Atlas (TCGA) cohort were performed to explore the immune function of the internal environment of tumours and its clinical correlation with ovarian carcinoma. Finally, four molecular subtypes were obtained based on the global immune-related genes. The correlation analysis and clinical characteristics showed that four subtypes were all significantly related to clinical stage; the immune scoring results indicated that most immune signatures were upregulated in C3 subtype, and the majority of tumour-infiltrating immune cells were upregulated in both C3 and C4 subtypes. Compared with other subtypes, C3 subtype had a higher BRCA1 mutation, higher expression of immune checkpoints, and optimal survival prognosis. These findings of the immunological microenvironment in tumours may provide new ideas for developing immunotherapeutic strategies for ovarian carcinoma. 相似文献
69.
Rui Zhou Huiying Sun Siting Zheng Jingwen Zhang Dongqiang Zeng Jianhua Wu Zhenhua Huang Xiaoxiang Rong Jianping Bin Yulin Liao Min Shi Wangjun Liao 《Journal of cellular and molecular medicine》2020,24(5):3229-3241
The heterogeneity in prognoses and chemotherapeutic responses of colon cancer patients with similar clinical features emphasized the necessity for new biomarkers that help to improve the survival prediction and tailor therapies more rationally and precisely. In the present study, we established a s troma-related l ncRNA s ignature (SLS) based on 52 lncRNAs to comprehensively predict clinical outcome. The SLS model could not only distinguish patients with different recurrence and mortality risks through univariate analysis, but also served as an independent factor for relapse-free and overall survival. Compared with the conventionally used TNM stage system, the SLS model clearly possessed higher predictive accuracy. Moreover, the SLS model also effectively screened chemotherapy-responsive patients, as only patients in the low-SLS group could benefit from adjuvant chemotherapy. The following cell infiltration and competing endogenous RNA (ceRNA) network functional analyses further confirmed the association between the SLS model and stromal activation-related biological processes. Additionally, this study also identified three phenotypically distinct colon cancer subtypes that varied in clinical outcome and chemotherapy benefits. In conclusion, our SLS model may be a significant determinant of survival and chemotherapeutic decision-making in colon cancer and may have a strong clinical transformation value. 相似文献
70.
FGFRL1 affects chemoresistance of small‐cell lung cancer by modulating the PI3K/Akt pathway via ENO1
Rui Chen Deyu Li Meng Zheng Bin Chen Ting Wei Yu Wang Man Li Weimei Huang Qin Tong Qi Wang Yaru Zhu Wei Fang Linlang Guo Shun Fang 《Journal of cellular and molecular medicine》2020,24(3):2123-2134
Fibroblast growth factor receptor‐like 1 (FGFRL1), a member of the FGFR family, has been demonstrated to play important roles in various cancers. However, the role of FGFRL1 in small‐cell lung cancer (SCLC) remains unclear. Our study aimed to investigate the role of FGFRL1 in chemoresistance of SCLC and elucidate the possible molecular mechanism. We found that FGFRL1 levels are significantly up‐regulated in multidrug‐resistant SCLC cells (H69AR and H446DDP) compared with the sensitive parental cells (H69 and H446). In addition, clinical samples showed that FGFRL1 was overexpressed in SCLC tissues, and high FGFRL1 expression was associated with the clinical stage, chemotherapy response and survival time of SCLC patients. Knockdown of FGFRL1 in chemoresistant SCLC cells increased chemosensitivity by increasing cell apoptosis and cell cycle arrest, whereas overexpression of FGFRL1 in chemosensitive SCLC cells produced the opposite results. Mechanistic investigations showed that FGFRL1 interacts with ENO1, and FGFRL1 was found to regulate the expression of ENO1 and its downstream signalling pathway (the PI3K/Akt pathway) in SCLC cells. In brief, our study demonstrated that FGFRL1 modulates chemoresistance of SCLC by regulating the ENO1‐PI3K/Akt pathway. FGFRL1 may be a predictor and a potential therapeutic target for chemoresistance in SCLC. 相似文献