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   384827篇
  免费   25306篇
  国内免费   2824篇
耳鼻咽喉   5272篇
儿科学   8343篇
妇产科学   10274篇
基础医学   53848篇
口腔科学   11936篇
临床医学   30455篇
内科学   79977篇
皮肤病学   8673篇
神经病学   27629篇
特种医学   14109篇
外国民族医学   82篇
外科学   61854篇
综合类   9951篇
现状与发展   1篇
一般理论   64篇
预防医学   17532篇
眼科学   9579篇
药学   31709篇
  1篇
中国医学   2177篇
肿瘤学   29491篇
  2021年   2514篇
  2019年   2838篇
  2018年   4646篇
  2017年   3547篇
  2016年   3667篇
  2015年   4157篇
  2014年   5875篇
  2013年   7634篇
  2012年   10392篇
  2011年   10646篇
  2010年   6395篇
  2009年   6051篇
  2008年   9801篇
  2007年   10637篇
  2006年   10566篇
  2005年   9628篇
  2004年   9168篇
  2003年   8893篇
  2002年   8561篇
  2001年   28474篇
  2000年   28961篇
  1999年   23801篇
  1998年   5130篇
  1997年   4159篇
  1996年   3732篇
  1995年   3521篇
  1994年   3150篇
  1993年   2886篇
  1992年   16213篇
  1991年   14959篇
  1990年   14301篇
  1989年   14122篇
  1988年   12723篇
  1987年   12212篇
  1986年   11235篇
  1985年   10425篇
  1984年   7006篇
  1983年   5680篇
  1982年   2769篇
  1979年   5564篇
  1978年   3400篇
  1977年   3013篇
  1975年   2695篇
  1974年   3106篇
  1973年   2912篇
  1972年   2881篇
  1971年   2833篇
  1970年   2551篇
  1969年   2594篇
  1968年   2287篇
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
1.
Whether the underlying mutations are homozygous, heterozygous, or co-inherited with other hemoglobinopathies, sickle cell disease is known to afflict the kidneys, leading to the clinical entity known as sickle cell nephropathy (SCN). Although common, SCN remains diagnostically elusive. Conventional studies performed in the context of renal disorders often fail to detect early stage SCN. This makes the quest for early diagnosis and treatment more challenging, and it increases the burden of chronic kidney disease-related morbidity among patients. Novel diagnostic tools have been employed to overcome this limitation. In this study, we discuss various biomarkers of SCN, including those employed in clinical practice and others recently identified in experimental settings, such as markers of vascular injury, endothelial dysfunction, tubulo-glomerular damage, and oxidative stress. These include kidney injury molecule-1, monocyte chemoattractant protein-1, N-acetyl-B-D-glucosaminidase, ceruloplasmin, orosomucoid, nephrin, and cation channels, among others. Furthermore, we explore the potential of novel biomarkers for refining diagnostic and therapeutic approaches and describe some obstacles that still need to be overcome. We highlight the importance of a collaborative approach to standardize the use of promising new biomarkers. Finally, we outline the limitations of conventional markers of renal damage as extensions of the pathogenic process occurring at the level of the organ and its functional subunits, with a discussion of the expected pattern of clinical and biochemical progression among patients with SCN.  相似文献   
2.
Background

Osimertinib is effective in patients with T790M mutation-positive advanced non-small-cell lung cancer (NSCLC) resistant to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). However, its effectiveness and safety in patients with poor performance status (PS) are unknown.

Methods

Enrolled patients showed disease progression after treatment with gefitinib, erlotinib, or afatinib; T790M mutation; stage IIIB, IV, or recurrent disease; and PS of 2–4. Osimertinib was orally administered at a dose of 80 mg/day. The primary endpoint of this phase II study (registration, jRCTs061180018) was response rate and the secondary endpoints were progression-free survival (PFS), overall survival (OS), disease control rate, and safety.

Results

Thirty-three patients were enrolled, of which 69.7% and 24.2% had PS of 2 and 3, respectively. One patient was excluded due to protocol violation; in the remaining 32 patients, the response rate was 53.1%; disease control rate was 75.0%; PFS was 5.1 months; and OS was 10.0 months. The most frequent adverse event of grade 3 or higher severity was lymphopenia (12.1%). Interstitial lung disease (ILD) was observed at all grades and at grades 3–5 in 15.2% (5/33) and 6.1% (2/33) of patients, respectively. Treatment-related death due to ILD occurred in one patient. Patients negative for activating EGFR mutations after osimertinib administration had longer median PFS than those positive for these mutations.

Conclusion

Osimertinib was sufficiently effective in EGFR-TKI-resistant, poor PS patients with T790M mutation-positive advanced NSCLC. Plasma EGFR mutation clearance after TKI treatment could predict the response to EGFR-TKIs.

  相似文献   
3.
4.
The use of radiation for primary liver cancers has historically been limited because of the risk of radiation-induced liver disease. Treatment fields have become more conformal because of several technical advances, and this has allowed for dose escalation. Stereotactic body radiation therapy (SBRT), also known as stereotactic ablative radiotherapy, is now able to safely treat liver tumors to ablative doses while sparing functional liver parenchyma by using highly conformal therapy. Several retrospective and small prospective studies have examined the use of SBRT for liver cancers; however, there is a lack of well-powered randomized studies to definitively guide management in these settings. Recent advances in systemic therapy for primary liver cancers have improved outcomes; however, the optimal selection criteria for SBRT as a local therapy remain unclear among other liver-directed options such as radiofrequency ablation, transarterial chemoembolization, and radioembolization.  相似文献   
5.
Peng  L. Q.  Wu  X. X.  Chen  G.  Cai  H. Z.  Tang  Y. P.  Chen  Q. Y.  Chen  X. Y. 《Bulletin of experimental biology and medicine》2022,173(3):335-340
Bulletin of Experimental Biology and Medicine - This study aimed to explore the effects of Wenyang Zhenshuai granules (WZG) on the morphology of cardiomyocytes, cell viability, and the expression...  相似文献   
6.
7.
Post-induction hypotension is common and associated with postoperative complications. We hypothesised that pneumatic leg compression reduces post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy. In this double-blind randomised study, patients were allocated randomly to the pneumatic leg compression group (n = 50) or control (n = 50). In the intervention group, pneumatic leg compression was initiated before induction of anaesthesia. In the control group, pneumatic leg compression was initiated 20 min after anaesthesia induction. The primary outcome was the incidence of post-induction hypotension in these groups. Post-induction hypotension was defined as systolic blood pressure < 90 mmHg during the first 20 min after induction. Haemodynamic variables and area under the curve of post-induction systolic blood pressure over time were assessed. Complications associated with pneumatic leg compression were recorded, including: peripheral neuropathy; compartment syndrome; extensive bullae beneath the leg sleeves; and pulmonary thromboembolism. The incidence of post-induction hypotension decreased in the pneumatic leg compression group compared with that in the control group; 5 (10%) vs. 29 (58%), respectively, p < 0.001. In the pneumatic leg compression group, the lowest systolic, diastolic and mean blood pressures 20 min after induction of anaesthesia were significantly greater than the control group. Pneumatic leg compression resulted in an increased area under the curve of systolic blood pressure in the first 20 min after induction, p = 0.001. There were no pneumatic leg compression-related complications. Pneumatic leg compression reduced post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy, suggesting that it is an effective and safe intervention to prevent post-induction hypotension among elderly patients undergoing general anaesthesia.  相似文献   
8.

Physical activity brings significant health benefits to middle-aged adults, although the research to date has been focused on late adulthood. This study aims to examine how ageing affects the self-reported and accelerometer-derived measures of physical activity levels in middle-aged adults. We employed the data recorded in the UK Biobank and analysed the physical activity levels of 2,998 participants (1381 men and 1617 women), based on self-completion questionnaire and accelerometry measurement of physical activity. We also assessed the musculoskeletal health of the participants using the dual-energy X-ray absorptiometry (DXA) measurements provided by the UK Biobank. Participants were categorised into three groups according to their age: group I younger middle-aged (40 to 49 years), group II older middle-aged (50 to 59 years), and group III oldest middle-aged (60 to 69 years). Self-reported physical activity level increased with age and was the highest in group III, followed by group II and I (P?<?0.05). On the contrary, physical activity measured by accelerometry decreased significantly with age from group I to III (P?<?0.05), and the same pertained to the measurements of musculoskeletal health (P?<?0.05). It was also shown that middle-aged adults mostly engaged in low and moderate intensity activities. The opposing trends of the self-reported and measured physical activity levels may suggest that middle-aged adults over-report their activity level as they age. They should be aware of the difference between their perceived and actual physical activity levels, and objective measures would be useful to prevent the decline in musculoskeletal health.

  相似文献   
9.
The Dutch Drug Rediscovery Protocol (DRUP) and the Australian Cancer Molecular Screening and Therapeutic (MoST) Program are similar nonrandomized, multidrug, pan-cancer trial platforms that aim to identify signals of clinical activity of molecularly matched targeted therapies or immunotherapies outside their approved indications. Here, we report results for advanced or metastatic cancer patients with tumors harboring cyclin D-CDK4/6 pathway alterations treated with CDK4/6 inhibitors palbociclib or ribociclib. We included adult patients that had therapy-refractory solid malignancies with the following alterations: amplifications of CDK4, CDK6, CCND1, CCND2 or CCND3, or complete loss of CDKN2A or SMARCA4. Within MoST, all patients were treated with palbociclib, whereas in DRUP, palbociclib and ribociclib were assigned to different cohorts (defined by tumor type and alteration). The primary endpoint for this combined analysis was clinical benefit, defined as confirmed objective response or stable disease ≥16 weeks. We treated 139 patients with a broad variety of tumor types; 116 with palbociclib and 23 with ribociclib. In 112 evaluable patients, the objective response rate was 0% and clinical benefit rate at 16 weeks was 15%. Median progression-free survival was 4 months (95% CI: 3-5 months), and median overall survival 5 months (95% CI: 4-6 months). In conclusion, only limited clinical activity of palbociclib and ribociclib monotherapy in patients with pretreated cancers harboring cyclin D-CDK4/6 pathway alterations was observed. Our findings indicate that monotherapy use of palbociclib or ribociclib is not recommended and that merging data of two similar precision oncology trials is feasible.  相似文献   
10.
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