首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   7182篇
  免费   741篇
  国内免费   592篇
耳鼻咽喉   178篇
儿科学   70篇
妇产科学   66篇
基础医学   868篇
口腔科学   99篇
临床医学   984篇
内科学   1061篇
皮肤病学   88篇
神经病学   366篇
特种医学   353篇
外国民族医学   2篇
外科学   753篇
综合类   1239篇
现状与发展   2篇
预防医学   436篇
眼科学   120篇
药学   763篇
  12篇
中国医学   442篇
肿瘤学   613篇
  2024年   109篇
  2023年   165篇
  2022年   300篇
  2021年   379篇
  2020年   297篇
  2019年   264篇
  2018年   244篇
  2017年   261篇
  2016年   236篇
  2015年   399篇
  2014年   426篇
  2013年   353篇
  2012年   492篇
  2011年   631篇
  2010年   417篇
  2009年   296篇
  2008年   395篇
  2007年   347篇
  2006年   372篇
  2005年   364篇
  2004年   219篇
  2003年   253篇
  2002年   203篇
  2001年   189篇
  2000年   165篇
  1999年   117篇
  1998年   81篇
  1997年   92篇
  1996年   65篇
  1995年   64篇
  1994年   44篇
  1993年   28篇
  1992年   37篇
  1991年   31篇
  1990年   26篇
  1989年   29篇
  1988年   29篇
  1987年   16篇
  1986年   14篇
  1985年   24篇
  1984年   7篇
  1983年   8篇
  1982年   8篇
  1981年   7篇
  1979年   1篇
  1978年   3篇
  1977年   1篇
  1976年   3篇
  1975年   1篇
  1932年   1篇
排序方式: 共有8515条查询结果,搜索用时 15 毫秒
141.
Wang  Ying  Geng  Ping  Yin  Jian  Xiao  Qin  Xiong  Jiali  Ling  Bingyu  Wang  Huihui  Xu  Jiyang 《Immunologic research》2021,69(6):612-617
Immunologic Research -  相似文献   
142.
143.
144.
Defects in the function and development of GABAergic interneurons have been linked to psychiatric disorders, so preservation of these interneurons in brain slices is important for successful electrophysiological recording in various ex vivo methods. However, it is difficult to maintain the activity and morphology of neurons in slices from mice of >30 days old. Here we evaluated the N-methyl-D-glucamine(NMDG)-based artificial cerebrospinal fl uid(a CSF) method for the preservation of interneurons in slices from mice of up to ~6 months old and discussed the steps that may affect their quality during slicing. We found that the NMDG-a CSF method rescued more cells than sucrose-a CSF and successfully preserved different types of interneurons including parvalbumin- and somatostatin-positive interneurons. In addition, both the chemical and electrical synaptic signaling of interneurons were maintained. These results demonstrate that the NMDG-a CSF method is suitable for the preservation of interneurons, especially in studies of gap junctions.  相似文献   
145.
BackgroundAlthough bone defect is one of the most common orthopaedic diseases, treatment remains a challenge and an issue of debate. Guided bone regeneration (GBR) is primarily accompanied by barrier membranes; however, optional membranes show some inherent flaws in clinical application. The purpose of this study was to observe the healing velocity and quality of repairing canine radius segmental defect using transferred autologous periosteum combined with fascia lata, which can provide better biological safety than other materials.ResultsBone union was seen in most individuals from the autologous periosteum combined with fascia lata group, within an average of 14.2 weeks. Histopathologic and SEM examinations both showed the different osteogenesis state between groups. Necropsy confirmed US findings with regard to distance of bone defects and location.ConclusionThese findings suggest that autologous periosteum combined with fascia lata is as effective as a GBR membrane, even in long tubular bone defects. With reliable biological safety, the autologous periosteum combined with fascia lata is expected to achieve increasing application in orthopaedic trauma patients.

Level of evidence

Not applicable, animal study.  相似文献   
146.
147.

Background:

Current randomized trials have demonstrated the effects of short-term rosuvastatin therapy in preventing contrast-induced acute kidney injury (CIAKI). However, the consistency of these effects on patients administered different volumes of contrast media is unknown.

Methods:

In the TRACK-D trial, 2998 patients with type 2 diabetes and concomitant chronic kidney disease (CKD) who underwent coronary/peripheral arterial angiography with or without percutaneous intervention were randomized to short-term (2 days before and 3 days after procedure) rosuvastatin therapy or standard-of-care. This prespecified analysis compared the effects of rosuvastatin versus standard therapy in patients exposed to (moderate contrast volume [MCV], 200–300 ml, n = 712) or (high contrast volume [HCV], ≥300 ml, n = 220). The primary outcome was the incidence of CIAKI. The secondary outcome was a composite of death, dialysis/hemofiltration or worsened heart failure at 30 days.

Results:

Rosuvastatin treatment was associated with a significant reduction in CIAKI compared with the controls (2.1% vs. 4.4%, P = 0.050) in the overall cohort and in patients with MCV (1.7% vs. 4.5%, P = 0.029), whereas no benefit was observed in patients with HCV (3.4% vs. 3.9%, P = 0.834). The incidence of secondary outcomes was significantly lower in the rosuvastatin group compared with control group (2.7% vs. 5.3%, P = 0.049) in the overall cohort, but it was similar between the patients with MCV (2.0% vs. 4.2%, P = 0.081) or HCV (5.1% vs. 8.8%, P = 0.273).

Conclusions:

Periprocedural short-term rosuvastatin treatment is effective in reducing CIAKI and adverse clinical events for patients with diabetes and CKD after their exposure to a moderate volume of contrast medium.  相似文献   
148.
Objective: To detect the ultrastructural changes in rabbits with type II decompression sickness (DCS), and study the therapeutic effects of hyperbaric oxygen (HBO). Methods: Twenty-seven male New Zealand rabbits were randomly divided equally into the DCS group, HBO treatment group and control group. Experimental models of each group were prepared. Lung apex tissues were harvested to prepare paraffin- and EPON812-embedded tissues. Results: In the DCS group, macroscopic and histological examination revealed severe and rapid damage to lung tissue. Ultrastructural examination revealed exudation of red blood cells in the alveolar space. Type I alveolar epithelial cells exhibited retracted cell processes and swollen mitochondria, and type II cells showed highly swollen mitochondria and decrease in cytoplasmic lamellar bodies. Dilatation and congestion of capillary vessels were accompanied by swelling of endothelial cells and incomplete basement membrane. In the HBO treatment group, the findings were somewhat similar to those in the DCS group, but the extent of damage was lesser. Only a small amount of tiny bubbles could be seen in the blood vessels. Type I alveolar epithelia cells and endothelial cells of the capillaries illustrated slight shortening of cells, swollen cytoplasm and decreased cell processes. Type II alveolar epithelial cells showed slight swelling of the mitochondria, decreased vacuolar degeneration of lamellar bodies, and increase in the number of free ribosomes. Conclusions: Our microscopic and ultrastructural findings confirm that the lung is an important organ affected by DCS. We also confirmed that HBO can alleviate DCS-induced pulmonary damage.  相似文献   
149.
Objective: Long non-coding RNAs (lncRNAs) XIST and HIF1A-AS1 have been shown to play important regulatory roles in cancer biology, and lncRNA-XIST and HIF1A-AS1 are upregulated in several cancers such as glioblastoma, breast cancer and thoracoabdominal aorta aneurysm, however, its value in the diagnosis of non-small cell lung cancer (NSCLC) is unclear. The aim of this study is to evaluate the clinical significance of serum XIST and HIF1A-AS1 as a biomarker in the screening of NSCLC. Methods: Expression levels of lncRNA-XIST and HIF1A-AS1 in tumor tissues and serum from NSCLC patients were evaluated by quantitative real-time PCR, and its association with overall survival of patients was analyzed by statistical analysis. Moreover, the XIST and lncRNA-XIST expression correlation between tumor tissues and plasma was demonstrated by linear regression analysis. Results: The levels of XIST (P < 0.05) and HIF1A-AS1 (P < 0.05) were significantly increased in tumor tissues or serum from NSCLC patients as compared to those of control group. Correlation of lncRNA-XIST or HIF1A-AS1 expression between tumor tissues and serum from the same individuals was confirmed in NSCLC patients. Moreover, serum levels of XIST and HIF1A-AS1 were significantly decreased after surgical treatment as compared to pre-operative. The ROC curves illustrated strong separation between the NSCLC patients and control group, with an AUC of 0.834 (95% CI: 0.726-0.935; P < 0.001) for XIST and 0.876 (95% CI: 0.793-0.965; P < 0.001) for HIF1A-AS1, however, the combination of XIST and HIF1A-AS1 yielded an AUC of 0.931 (95% CI: 0.869-0.990; P < 0.001), which was significantly improved as compared to XIST or HIF1A-AS1 alone. Conclusion: Our results demonstrated that increased serum XIST and HIF1A-AS1 could be used as a predictive biomarker for NSCLC screening, and that combination of XIST and HIF1A-AS1 had a higher positive diagnostic efficiency of NSCLC than XIST or HIF1A-AS1 alone.  相似文献   
150.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号