全文获取类型
收费全文 | 12549篇 |
免费 | 918篇 |
国内免费 | 1126篇 |
专业分类
14593篇 |
出版年
2024年 | 26篇 |
2023年 | 192篇 |
2022年 | 481篇 |
2021年 | 784篇 |
2020年 | 478篇 |
2019年 | 596篇 |
2018年 | 624篇 |
2017年 | 408篇 |
2016年 | 575篇 |
2015年 | 871篇 |
2014年 | 998篇 |
2013年 | 989篇 |
2012年 | 1177篇 |
2011年 | 1096篇 |
2010年 | 652篇 |
2009年 | 572篇 |
2008年 | 657篇 |
2007年 | 569篇 |
2006年 | 447篇 |
2005年 | 350篇 |
2004年 | 317篇 |
2003年 | 289篇 |
2002年 | 269篇 |
2001年 | 191篇 |
2000年 | 144篇 |
1999年 | 169篇 |
1998年 | 104篇 |
1997年 | 98篇 |
1996年 | 80篇 |
1995年 | 65篇 |
1994年 | 49篇 |
1993年 | 37篇 |
1992年 | 56篇 |
1991年 | 26篇 |
1990年 | 26篇 |
1989年 | 43篇 |
1988年 | 21篇 |
1987年 | 12篇 |
1986年 | 10篇 |
1985年 | 24篇 |
1984年 | 6篇 |
1983年 | 10篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Li Dongyang Liu Xiaoyu Li Tong Wang Xiaoran Jia Shuwei Wang Ping Wang Yu-Feng 《Neurochemical research》2021,46(4):980-991
Neurochemical Research - Oxytocin (OT) neuronal activity is the key factor for breastfeeding and it can be disrupted by mother-baby separation. To explore cellular mechanisms underlying OT neuronal... 相似文献
992.
993.
Lin Zhu Xiaoyan Yang Juyi Li Xiong Jia Xiangli Bai Ying Zhao Wenzhuo Cheng Meng Shu Yan Zhu Si Jin 《遗传学报》2021,48(2):134-146
Gene therapy has become the most effective treatment for monogenic diseases. Congenital LEPTIN deficiency is a rare autosomal recessive monogenic obesity syndrome caused by mutations in the Leptin gene. Ob/ob mouse is a monogenic obesity model, which carries a homozygous point mutation of C to T in Exon 2 of the Leptin gene. Here, we attempted to edit the mutated Leptin gene in ob/ob mice preadipocytes and inguinal adipose tissues using CRISPR/Cas9 to correct the C to T mutation and restore the production of LEPTIN protein by adipocytes. The edited preadipocytes exhibit a correction of 5.5% of Leptin alleles and produce normal LEPTIN protein when differentiated into mature adipocytes. The ob/ob mice display correction of 1.67% of Leptin alleles, which is sufficient to restore the production and physiological functions of LEPTIN protein, such as suppressing appetite and alleviating insulin resistance. Our study suggests CRISPR/Cas9-mediated in situ genome editing as a feasible therapeutic strategy for human monogenic diseases, and paves the way for further research on efficient delivery system in potential future clinical application. 相似文献
994.
Ning Xie Yunfan Bai Lu Qiao Yuru Bai Jian Wu Yan Li Mingzuo Jiang Bing Xu Zhen Ni Ting Yuan Yongquan Shi Kaichun Wu Feng Xu Jinhai Wang Lei Dong Na Liu 《Journal of cellular and molecular medicine》2021,25(8):4014-4027
The ADP-ribosylation factor-like proteins (ARLs) have been proved to regulate the malignant phenotypes of several cancers. However, the exact role of ARLs in gastric cancer (GC) remains elusive. In this study, we systematically investigate the expression status, interactive relations, potential pathways, genetic variations and clinical values of ARLs in GC. We find that ARLs are significantly dysregulated in GC and involved in various cancer-related pathways. Subsequently, machine learning models identify ARL4C as one of the two most significant clinical indicators among ARLs for GC. Furthermore, ARL4C silencing remarkably inhibits the growth and metastasis of GC cells both in vitro and in vivo. Moreover, enrichment analysis indicates that ARL4C is highly correlated with TGF-β1 signalling. Correspondingly, TGF-β1 treatment dramatically increases ARL4C expression and ARL4C knockdown inhibits the phosphorylation level of Smads, downstream factors of TGF-β1. Meanwhile, the coexpression of ARL4C and TGF-β1 worsens the prognosis of GC patients. Our work comprehensively demonstrates the crucial role of ARLs in the carcinogenesis of GC and the specific mechanisms underlying the GC-promoting effects of TGF-β1. More importantly, we uncover the great promise of ARL4C-targeted therapy in improving the efficacy of TGF-β1 inhibitors for GC patients. 相似文献
995.
996.
Guangxia Cui Huijie Leng Ke Wang Jianwei Wang Sainan Zhu Jing Jia Xing Chen Weiguang Zhang Lihua Qin Wenpei Bai 《PloS one》2013,8(12)
This study aims to evaluate the effects of Remifemin (isopropanolic extract of Cimicifuga Racemosa) on postmenopausal osteoporosis. 120 female Sprague-Dawley rats were randomly assigned to four groups: sham surgery with vehicle, ovariectomy with vehicle, ovariectomy with estradiol valerate, or ovariectomy with Remifemin. Daily oral administrations of the vehicle, estradiol valerate, or Remifemin began 2 weeks after surgery and lasted to 4, 8, or 12 weeks. Ten rats in each group were sacrificed at each timestep with assessment of bone mineral density, trabecular bone structure, and biomechanical parameters of the femur and lumbar vertebra. Bone turnover markers were evaluated 12 weeks after surgery. Both drugs prevented bone density loss in the distal end of the femur and preserved the trabecular bone structure in both the lumbar vertebra and distal end of the femur following ovariectomy. Both drugs protected bone stiffness at the tested regions and reduced bone reabsorption in ovariectomized rats. The preventive effects of Remifemin against bone-loss can rival those of estradiol valerate if treatment duration is adequately extended. In conclusion, Remifemin may demonstrate equivalent effects to estradiol valerate in terms of preventing postmenopausal osteoporosis. 相似文献
997.
Objective
The purpose of this study was to analyze the clinical features and prognostic factors of surgical outcome of foot drop caused by lumbar degenerative disease and put forward the clinical stage.Methods
We retrospectively reviewed 135 patients with foot drop due to lumbar degenerative disease. The clinical features and mechanism were analyzed. Age, sex, duration of palsy, preoperative muscle strength of tibialis anterior (TA), sensation defect of affected lower limb, affected foot, diagnosis and compressed nerve roots were recorded and compared with surgical outcome.Results
Foot drop was observed in 8.1% of all inpatients of lumbar degenerative disease. L5 nerve root compression was observed in 126 of all 135 patients (93.3%). Single, double and triple roots compression was observed respectively in 43, 83, and 9 patients (31.9%, 61.5%, and 6.6%). But there was no significant relationship between preoperative muscle strength of TA and the number of compressed roots. The muscle strength of TA was improved in 113 (83.7%) patients after surgery, but it reached to >=4 in only 21 (15.6%) patients. Improvement of the muscle strength of TA was almost stable at the 6-month follow-up. At the last follow-up, the muscle strength of TA was 1, 2, 3, 4, 5 respectively in 28, 24, 62, 13, 8 patients. Multivariate logistic regression showed duration of palsy (p=0.0360, OR=2.543), preoperative muscle strength of TA (p=0.0064, OR=5.528) and age (p=0.0309, OR=3.208) were factors that influenced recovery following an operation.Conclusions
L5 nerve root was most frequently affected. The muscle strength of TA improved in most patients after surgery, but few patients can get a good recovery from foot drop. Patients of shorter duration of palsy, better preoperative muscle strength of TA and younger age showed a better surgical outcome. 相似文献998.
In eukaryotic cells short-lived proteins are degraded in a specific process by the ubiquitin-proteasome system (UPS), whereas long-lived proteins and damaged organelles are degraded by macroautophagy (hereafter referred to as autophagy). A growing body of evidence now suggests that autophagy is important for clearance of protein aggregates that form in cells as a consequence of ageing, oxidative stress, alterations that elevate the amounts of certain aggregation-prone proteins or expression of aggregating mutant variants of specific proteins. Autophagy is generally considered to be a non-specific, bulk degradation process. However, a recent study suggests that p62/SQSTM1 may link the recognition of polyubiquitinated protein aggregates to the autophagy machinery.1 This protein is able to polymerize via its N-terminal PB1 domain and to recognize polyubiquitin via its C-terminal UBA domain. It can also recruit the autophagosomal protein LC3 and co-localizes with many types of polyubiquitinated protein aggregates.1 Here we discuss possible implications of these findings and raise some questions for further investigation. 相似文献
999.
hOGG1 Ser326Cys Polymorphism and Risk of Hepatocellular Carcinoma among East Asians: A Meta-Analysis
Wenjun Wang Shuangsuo Dang Yaping Li Mingzhu Sun Xiaoli Jia Rui Wang Jingkun Liu 《PloS one》2013,8(4)
Background
The hOGG1 gene encodes a DNA glycosylase enzyme responsible for DNA repair. The Ser326Cys polymorphism in this gene may influence its repair ability and thus plays a role in carcinogenesis. Several case-control studies have been conducted on this polymorphism and its relationship with the risk of hepatocellular carcinoma (HCC) among East Asians. However, their results are inconsistent.Methods
We performed a meta-analysis of published case-control studies assessing the association of the hOGG1 Ser326Cys polymorphism with HCC risk among East Asians. PubMed, EMBASE, SCI, BIOSIS, CNKI and WanFang databases were searched. A random-effect model was used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs). Analyses were conducted for additive, dominant and recessive genetic models.Results
Eight studies were identified involving 2369 cases and 2442 controls assessing the association of the hOGG1 Ser326Cys polymorphism with HCC risk among East Asians. Applying a dominant genetic model, only in the Chinese population, the Cys allele was significantly associated with increased risk of HCC (OR 1.56, 95% CI 1.12–2.17). However, two studies influenced this finding according to sensitivity analysis. Furthermore, considerable heterogeneity and bias existed among Chinese studies.Conclusion
There is limited evidence to support that the hOGG1 Ser326Cys polymorphism is associated with HCC risk among East Asians. Well-designed and large-sized studies are required to determine this relationship. 相似文献1000.
Trust is a vital lubricant that increases the sense of security in social interactions. In this study, we investigated the intergroup trust between the Uyghur and the Han, the two largest ethnic groups in Xinjiang, China, with a Go/No-Go Association Task. Specifically, we instructed Uyghur and Han participants to respond to ethnic faces (Uyghur vs. Han) and trust/distrust words and measured the strength of the automatic associations between the faces and words for both in-group and out-group pairs. As expected, both ethnic groups showed implicit in-group trust and out-group distrust, but the Han group demonstrated stronger in-group trust and out-group distrust toward the Uyghur than the Uyghur group toward the Han. However, the magnitude of distrust of the Han toward the Uyghur was small to medium as compared with that reported by other intergroup relationship research. In addition, participant geographic location was associated with out-group distrust. These findings offer implications for developing effective strategies to encourage trust between conflicting groups. 相似文献