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   2810篇
  免费   222篇
  国内免费   20篇
耳鼻咽喉   49篇
儿科学   34篇
妇产科学   10篇
基础医学   367篇
口腔科学   38篇
临床医学   183篇
内科学   966篇
皮肤病学   17篇
神经病学   139篇
特种医学   63篇
外科学   611篇
综合类   6篇
预防医学   66篇
眼科学   12篇
药学   125篇
中国医学   3篇
肿瘤学   363篇
  2024年   4篇
  2023年   28篇
  2022年   82篇
  2021年   114篇
  2020年   71篇
  2019年   86篇
  2018年   97篇
  2017年   97篇
  2016年   101篇
  2015年   95篇
  2014年   101篇
  2013年   120篇
  2012年   194篇
  2011年   221篇
  2010年   122篇
  2009年   116篇
  2008年   150篇
  2007年   160篇
  2006年   169篇
  2005年   147篇
  2004年   133篇
  2003年   117篇
  2002年   132篇
  2001年   47篇
  2000年   45篇
  1999年   37篇
  1998年   36篇
  1997年   22篇
  1996年   12篇
  1995年   20篇
  1994年   10篇
  1993年   8篇
  1992年   19篇
  1991年   16篇
  1990年   8篇
  1989年   10篇
  1988年   7篇
  1987年   5篇
  1986年   6篇
  1985年   10篇
  1984年   11篇
  1983年   11篇
  1982年   5篇
  1981年   4篇
  1979年   7篇
  1978年   7篇
  1977年   7篇
  1976年   4篇
  1973年   4篇
  1971年   5篇
排序方式: 共有3052条查询结果,搜索用时 15 毫秒
81.
82.
83.
The basic region–leucine zipper (bZip) factor BTB, CNC homology 2 (BACH2) is known to have important roles in class switch recombination and somatic hypermutation (SHM) of the immunoglobulin (Ig) gene. In this study, we investigated the relationship between the expression of BACH2 and the status of SHM of the Ig heavy chain gene variable region (IgHV) for SHM in diffuse large B‐cell lymphoma (DLBCL). We examined 20 cases of DLBCL, 13 of which were germinal center B‐cell (GCB) DLBCL and 7 were non‐GCB DLBCL. Seven cases were negative, 6 were positive (cytoplasmic expression) and 7 were strongly positive (both nuclear and cytoplasmic expression) for BACH2. Confirmed mutation (CM) was identified in 8 cases and the CM index (number of confirmed mutations per 10 subclones) was distributed from 0 to 5. A CM index of 7 strongly positive (over‐expression) cases with BACH2 were distributed from 0 to 5, and that of 7 negative and 6 positive cases were distributed from 0 to 1. Over‐expression of BACH2 was statistically related to CM index (P = 0.008). In conclusion, over‐expression of BACH2 is critical for ongoing SHM of IgHV in DLBCL, and our data suggest that BACH2 may play an essential role for SHM of the Ig gene in B‐cell lymphoma.  相似文献   
84.
We report 2 cases of advanced gastric cancer with synchronous liver metastases who were successfully downstaged using S-1 plus low-dose cisplatin chemotherapy followed by surgical resection. S-1 was administered orally (80 mg/m(2)/day) twice daily for 14 consecutive days, and cisplatin (15 mg/m(2)) was infused over 1 h on days 1 and 8. Successful downstaging of the hepatic metastases was confirmed by imaging analyses; however, neither patient showed a complete response of the primary lesion in the stomach. Toxicities, according to the WHO criteria, were mild. The patients underwent surgical resection within 4 weeks after the last chemotherapy. Postoperatively, they were discharged without complications and received adjuvant chemotherapy. Both patients remained alive and well at 17 and 12 months after surgery, respectively, without recurrence. These cases provide further evidence that S-1 plus low-dose cisplatin chemotherapy enables downstaging of advanced gastric cancer and a subsequent potentially curative resection without serious complications.  相似文献   
85.
Toll-like receptors (TLRs) are innate recognition molecules for microbial products, but their direct interactions with corresponding ligands remain unclarified. LPS, a membrane constituent of gram-negative bacteria, is the best-studied TLR ligand and is recognized by TLR4 and MD-2, a molecule associated with the extracellular domain of TLR4. Although TLR4-MD-2 recognizes LPS, little is known about the physical interaction between LPS and TLR4-MD-2. Here, we demonstrate cell surface LPS-TLR4-MD-2 complexes. CD14 greatly enhances the formation of LPS-TLR4-MD-2 complexes, but is not coprecipitated with LPS-TLR4-MD-2 complexes, suggesting a role for CD14 in LPS loading onto TLR4-MD-2 but not in the interaction itself between LPS and TLR4-MD-2. A tentative dissociation constant (Kd) for LPS-TLR4-MD-2 complexes was approximately 3 nM, which is approximately 10-20 times lower than the reported Kd for LPS-MD-2 or LPS-CD14. The presence of detergent disrupts LPS interaction with CD14 but not with TLR4-MD-2. E5531, a lipid A antagonist developed for therapeutic intervention of endotoxin shock, blocks LPS interaction with TLR4-MD-2 at a concentration 100 times lower than that required for blocking LPS interaction with CD14. These results reveal direct LPS interaction with cell surface TLR4-MD-2 that is distinct from that with MD-2 or CD14.  相似文献   
86.
Cardiac amyloidosis is an infiltrative and restrictive cardiomyopathy caused by the extracellular deposition of amyloid fib-rils within the heart as systemic amyloidosis,lead-ing to heart failure,reduced quality of life,and death.[1]There are two major amyloid fibril proteins that af-fect the heart:amyloid immunoglobulin light chain(AL)and amyloid transthyretin(ATTR).The latter is further subdivided into wild-type ATTR and variant types based on the presence of a mutation in the transthyretin gene.  相似文献   
87.

Background

The Kidney Disease: Improving Global Outcomes (KDIGO) group proposed to adopt the 48-h time window for the 0.3  mg/dL rise in serum creatinine (sCr) proposed by the Acute Kidney Injury Network (AKIN) group as a modification to the original risk, injury, failure, loss, and end-stage renal disease criteria, keeping the 7-day window for the 50 % increase in sCr from baseline. The present study evaluates the prevalence of acute kidney injury (AKI) and the accuracy of predicting mortality based on the KDIGO and AKIN criteria.

Patients and methods

We retrospectively studied a cohort of 2579 patients admitted to the intensive care unit of Nagoya University Hospital between 2005 and 2009.

Results

The total AKI prevalence was higher according to the KDIGO than to the AKIN criteria (38.4 versus 29.5 %). In-hospital mortality rates were higher among 238 patients classified as non-AKI by the AKIN but AKI by the KDIGO criteria than among those classified as non-AKI by both criteria (7.1 versus 2.7 %). Survival curves generated using KDIGO significantly differed among all stages, but not between AKIN stages I and II. Multivariate analysis showed that KDIGO criteria were better in a statistical model than the AKIN criteria according to the Akaike information criterion. Harrell’s C statistic was greater for the KDIGO than for the AKIN criteria.

Conclusions

The KDIGO criteria have improved sensitivity without compromising specificity for AKI and might predict mortality at least as well as the AKIN criteria.  相似文献   
88.
Investigation into arthritis as well as the numerous bone phenotypes found in mice lacking immune-related genes has highlighted the importance of the dynamic interplay between the bone and immune systems. It has recently led to both the emergence and subsequent rapid evolution of the field of osteoimmunology. Receptor activator of nuclear factor-κB ligand (RANKL) stimulates osteoclastogenesis through the nuclear factor of activated T cells, cytoplasmic 1 (NFATc1), which is well known as a crucial regulator of immunity. Studies on RANKL signaling revealed various immune-related genes which are involved in the regulation of osteoclastogenesis. Bone destruction in rheumatoid arthritis is caused by the enhanced activity of osteoclasts resulting from the activation of T cells. Here we describe our efforts to address the challenging question as to how abnormal T-cell activation mechanistically induces bone destruction. The scope of osteoimmunology has been extended to encompass a wide range of molecular and cellular interactions, the elucidation of which will provide a scientific basis for future therapeutic approaches to diseases related to both the bone and immune systems.  相似文献   
89.
The mechanisms that drive the development of diabetic nephropathy remain undetermined. Only 30-40% of patients with diabetes mellitus develop overt nephropathy, which suggests that other contributing factors besides the diabetic state are required for the progression of diabetic nephropathy. Endothelial dysfunction is associated with human diabetic nephropathy and retinopathy, and advanced diabetic glomerulopathy often exhibits thrombotic microangiopathy, including glomerular capillary microaneurysms and mesangiolysis, which are typical manifestations of endothelial dysfunction in the glomerulus. Likewise, diabetic mice with severe endothelial dysfunction owing to deficiency of endothelial nitric oxide synthase develop progressive nephropathy and retinopathy similar to the advanced lesions observed in humans with diabetes mellitus. Additionally, inhibitors of the renin-angiotensin system fail to be renoprotective in some individuals with diabetic nephropathy (due in part to aldosterone breakthrough) and in some mouse models of the disease. In this Review, we discuss the clinical and experimental evidence that supports a role for endothelial nitric oxide deficiency and subsequent endothelial dysfunction in the progression of diabetic nephropathy and retinopathy. If endothelial dysfunction is the key factor required for diabetic nephropathy, then agents that improve endothelial function or raise intraglomerular nitric oxide level could be beneficial in the treatment of diabetic nephropathy.  相似文献   
90.
Bleeding after gastric endoscopic submucosal dissection (ESD) remains problematic, especially in patients receiving antithrombotic therapy. Therefore, this study aimed to identify the risk factors. In this retrospective study, patients (n = 1,207) who underwent gastric ESD while receiving antithrombotic therapy were enrolled at Osaka Medical and Pharmaceutical University Hospital and 18 other referral hospitals in Japan. Risks of post-ESD bleeding were calculated using multivariable logistic regression. The dataset was divided into a derivation cohort and a validation cohort. We created a prediction model using the derivation cohort. The accuracy of the model was evaluated using the validation cohort. Post-ESD bleeding occurred in 142 (11.8%) participants. Multivariable analysis yielded an odds ratio of 2.33 for aspirin, 4.90 for P2Y12 receptor antagonist, 1.79 for cilostazol, 0.95 for other antithrombotic agents, 6.53 for warfarin, 5.65 for dabigatran, 7.84 for apixaban, 10.45 for edoxaban, 6.02 for rivaroxaban, and 1.46 for heparin bridging. The created prediction model was called safe ESD management using the risk analysis of post-bleeding in patients with antithrombotic therapy (SAMURAI). This model had good predictability, with a C-statistic of 0.77. In conclusion, use of the SAMURAI model will allow proactive management of post-ESD bleeding risk in patients receiving antithrombotic therapy.  相似文献   
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