全文获取类型
收费全文 | 2735509篇 |
免费 | 208306篇 |
国内免费 | 13645篇 |
专业分类
耳鼻咽喉 | 37413篇 |
儿科学 | 89322篇 |
妇产科学 | 73760篇 |
基础医学 | 384760篇 |
口腔科学 | 76521篇 |
临床医学 | 249302篇 |
内科学 | 530220篇 |
皮肤病学 | 60310篇 |
神经病学 | 210544篇 |
特种医学 | 106419篇 |
外国民族医学 | 945篇 |
外科学 | 413606篇 |
综合类 | 79545篇 |
现状与发展 | 45篇 |
一般理论 | 854篇 |
预防医学 | 204283篇 |
眼科学 | 64641篇 |
药学 | 205403篇 |
99篇 | |
中国医学 | 12852篇 |
肿瘤学 | 156616篇 |
出版年
2021年 | 22128篇 |
2019年 | 23934篇 |
2018年 | 33022篇 |
2017年 | 25543篇 |
2016年 | 27562篇 |
2015年 | 32699篇 |
2014年 | 44646篇 |
2013年 | 62466篇 |
2012年 | 86604篇 |
2011年 | 91927篇 |
2010年 | 55126篇 |
2009年 | 50996篇 |
2008年 | 83706篇 |
2007年 | 88758篇 |
2006年 | 89409篇 |
2005年 | 86337篇 |
2004年 | 82010篇 |
2003年 | 78271篇 |
2002年 | 75557篇 |
2001年 | 136036篇 |
2000年 | 139727篇 |
1999年 | 117456篇 |
1998年 | 31202篇 |
1997年 | 27687篇 |
1996年 | 27576篇 |
1995年 | 27750篇 |
1994年 | 25771篇 |
1993年 | 23400篇 |
1992年 | 90081篇 |
1991年 | 87427篇 |
1990年 | 84458篇 |
1989年 | 80943篇 |
1988年 | 74150篇 |
1987年 | 72662篇 |
1986年 | 68028篇 |
1985年 | 64727篇 |
1984年 | 48003篇 |
1983年 | 40562篇 |
1982年 | 23050篇 |
1979年 | 42470篇 |
1978年 | 29342篇 |
1977年 | 24962篇 |
1976年 | 23231篇 |
1975年 | 24930篇 |
1974年 | 29826篇 |
1973年 | 28469篇 |
1972年 | 26505篇 |
1971年 | 24182篇 |
1970年 | 22675篇 |
1969年 | 20943篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
41.
Qing-Yang Que Lin-Cheng Zhang Jia-Qi Bao Sun-Bin Ling Xiao Xu 《World journal of gastrointestinal surgery》2022,14(5):397-408
Over the last 40 years, the incidence and prevalence of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) have continued to increase. Compared to other epithelial neoplasms in the same organ, GEP-NENs exhibit indolent biological behavior, resulting in more chances to undergo surgery. However, the role of surgery in high-grade or advanced GEP-NENs is still controversial. Surgery is associated with survival improvement of well-differentiated high-grade GEP-NENs, whereas poorly differentiated GEP-NENs that may benefit from resection require careful selection based on Ki67 and other tissue bio markers. Additionally, surgery also plays an important role in locally advanced and metastatic disease. For locally advanced GEP-NENs, isolated major vascular involvement is no longer an absolute contraindication. In the setting of metastatic GEP-NENs, radical intended surgery is recommended for patients with low-grade and resectable metastases. For unresectable metastatic disease, a variety of surgical approaches, including cytoreduction of liver metastasis, liver transplantation, and surgery after neoadjuvant treatment, show survival benefits. Primary tumor resection in GEP-NENs with unresectable metastatic disease is associated with symptom control, prolonged survival, and improved sensitivity toward systemic therapies. Although there is no established neoadjuvant or adjuvant strategy, increasing attention has been given to this emerging research area. Some studies have reported that neoadjuvant therapy effectively reduces tumor burden, improves the effectiveness of subsequent surgery, and decreases surgical complications. 相似文献
42.
Steven P. Rowe MD PhD Martin G. Pomper MD PhD 《CA: a cancer journal for clinicians》2022,72(4):333-352
The authors define molecular imaging, according to the Society of Nuclear Medicine and Molecular Imaging, as the visualization, characterization, and measurement of biological processes at the molecular and cellular levels in humans and other living systems. Although practiced for many years clinically in nuclear medicine, expansion to other imaging modalities began roughly 25 years ago and has accelerated since. That acceleration derives from the continual appearance of new and highly relevant animal models of human disease, increasingly sensitive imaging devices, high-throughput methods to discover and optimize affinity agents to key cellular targets, new ways to manipulate genetic material, and expanded use of cloud computing. Greater interest by scientists in allied fields, such as chemistry, biomedical engineering, and immunology, as well as increased attention by the pharmaceutical industry, have likewise contributed to the boom in activity in recent years. Whereas researchers and clinicians have applied molecular imaging to a variety of physiologic processes and disease states, here, the authors focus on oncology, arguably where it has made its greatest impact. The main purpose of imaging in oncology is early detection to enable interception if not prevention of full-blown disease, such as the appearance of metastases. Because biochemical changes occur before changes in anatomy, molecular imaging—particularly when combined with liquid biopsy for screening purposes—promises especially early localization of disease for optimum management. Here, the authors introduce the ways and indications in which molecular imaging can be undertaken, the tools used and under development, and near-term challenges and opportunities in oncology. 相似文献
43.
K.V.P. SaiKiran Debasish Biswal Sonu Kumari Agrawal Priyam Batra Tanu Sagar S.K. Choudhary Nishant Verma Rama Chaudhry 《Indian journal of medical microbiology》2022,40(2):274-278
PurposeAnaerobic infections are common yet life-threatening. They are being recovered from all sites of the body, including the cardiovascular system. This study was aimed to determine the retrospective analysis on the isolation of anaerobes in cardiovascular samples received for a decade-long duration. It helps in knowing the frequency of isolation of anaerobic causes of cardiovascular infection.MethodsAll cardiovascular samples from the department of Cardio-thoracic vascular surgery from January 2010 to December 2020 were studied.ResultsOf 601 samples received, predominant samples were vegetations and valvular tissues of 258, followed by 98 samples of pericardial tissues, 92 samples of embolus, 90 samples of blood and post-operative collections, and 63 excised aneurysms and vascular grafts. Of the total, 15 samples grew anaerobes where Clostridium species were the predominant isolates. Clostridioides difficile was isolated in 2 samples.ConclusionsAnaerobes in cardiovascular samples are uncommon yet form a significant cause of morbidity and mortality. Most infections are from the contiguous spread, penetrating trauma, and hematogenous causing endocarditis or valvular infections. These conditions and samples form the seat of infectious focus and clinical suspicion towards the anaerobic cause of these conditions, especially in conventional routine culture-negative samples. Timely diagnosis of anaerobic infections plays a vital role in the good prognostic outcome of patients undergoing cardiothoracic and vascular surgery. 相似文献
44.
Biomedical Engineering - The possible use of the vortex effect in medical transfusion–infusion solution heaters was studied. A design for a device is presented, along with the trial results.... 相似文献
45.
Laura A. Huppert MD Ozge Gumusay MD Dame Idossa MD Hope S. Rugo MD 《CA: a cancer journal for clinicians》2023,73(5):480-515
Hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer is defined by the presence of the estrogen receptor and/or the progesterone receptor and the absence of HER2 gene amplification. HR-positive/HER2-negative breast cancer accounts for 65%–70% of all breast cancers, and incidence increases with increasing age. Treatment varies by stage, and endocrine therapy is the mainstay of treatment in both early stage and late-stage disease. Combinations with cyclin-dependent kinase 4/6 inhibitors have reduced distant recurrence in the early stage setting and improved overall survival in the metastatic setting. Chemotherapy is used based on stage and tumor biology in the early stage setting and after endocrine resistance for advanced disease. New therapies, including novel endocrine agents and antibody-drug conjugates, are now changing the treatment landscape. With the availability of new treatment options, it is important to define the optimal sequence of treatment to maximize clinical benefit while minimizing toxicity. In this review, the authors first discuss the pathologic and molecular features of HR-positive/HER2-negative breast cancer and mechanisms of endocrine resistance. Then, they discuss current and emerging therapies for both early stage and metastatic HR-positive/HER2-negative breast cancer, including treatment algorithms based on current data. 相似文献
46.
Bioimpedance as a measure of fluids in patients with septic shock. A prospective observational study
Janne Meisner Madsen Theis S. Itenov Ellen Bjerre Koch Morten H. Bestle 《Acta anaesthesiologica Scandinavica》2023,67(3):319-328
Background
Septic shock is often treated with aggressive fluid resuscitation leading to profound fluid overload. The assessment of fluid status relies on suboptimal measures making treatment difficult. Bioelectrical impedance analysis is an alternative but the validity is unclear. The aim of this study was to determine the validity of bioelectrical impedance analysis for fluid measures in patients with septic shock.Methods
Single-center, prospective observational cohort study. We included adult ICU patients with septic shock. We evaluated the agreement between measures on the left and right side of the patient and measures 1 h apart by two bioelectrical impedance devices. Results are presented as Bland Altman plots with 95% Limits of Agreements (LoA) and as correlations between bioelectrical impedance analysis results and clinical markers of fluids.Results
Forty-nine patients were included. The agreement between measures on the left and the right side of the patient and after 1 h was overall without bias, but with wide LoA's. Fluid overload 1 h apart showed the most narrow 95% LoA (−2.4–2.9 L). The same wide limits of agreements were observed when comparing devices. For example, total body water with 95% LoA of −14.8 –16.7 L. Correlations between bioelectrical impedance analysis and clinical measures were low but statistically significant.Conclusions
In patients with septic shock bioelectrical impedance analysis had no systematic errors or bias, but wide limits of agreement, indicating that the devices have a large and uncorrectable random error. Fluid status by bioelectrical impedance analysis is not sufficiently accurate to guide treatment in this group of patients. 相似文献47.
48.
Maja Popovic Gorana Matovina-Brko Masa Jovic Lazar S Popovic 《World journal of clinical oncology》2022,13(1):28-38
Renal cell cancer (RCC) represents 2%-3% of all adulthood cancers and is the most common malignant neoplasm of the kidney (90%). In the mid-nineties of the last century, the standard of treatment for patients with metastatic RCC was cytokines. Sunititib and pazopanib were registered in 2007 and 2009, respectively, and have since been the standard first-line treatment for metastatic clear cell RCC (mccRCC). Renal cell cancer is a highly immunogenic tumor with tumor infiltrating cells, including CD8+ T lymphocytes, dendritic cells, natural killer cells (NK) and macrophages. This observation led to the design of new clinical trials in which patients were treated with immunotherapy. With the growing evidence that proangiogenic factors can have immunomodulatory effects on the host’s immune system, the idea of combining angiogenic drugs with immunotherapy has emerged, and new clinical trials have been designed. In the last few years, several therapeutic options have been approved [immunotherapy and immunotherapy/tyrosine kinase inhibitors (TKI)] for the first-line treatment of mccRCC. Nivolumab/ipilimumab is approved for the treatment of patients with inter mediate and poor prognoses. Several checkpoint inhibitors (pembrolizumab, nivolumab, avelumab) in combination with TKI (axitinib, lenvatinib, cabozan tinib) are approved for the treatment of patients regardless of their International mRCC Database Consortium prognostic group and PD-L1 expression. There is no specific and ideal biomarker that could help in selecting the ideal patient for the appropriate first-line treatment. 相似文献
49.
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
50.
Marie V. Plaisime PhD MPH Marie Jipguep-Akhtar PhD Joseph J. Locascio PhD Harolyn M. E. Belcher MD MHS Rachel R. Hardeman PhD MPH Katherine Picho-Kiroga PhD Sylvia P. Perry PhD Sean M. Phelan PhD MPH Michelle van Ryn PhD LMFT MPH John F. Dovidio PhD 《Health services research》2023,58(Z2):229-237