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   26596篇
  免费   1379篇
  国内免费   138篇
耳鼻咽喉   275篇
儿科学   533篇
妇产科学   550篇
基础医学   3367篇
口腔科学   665篇
临床医学   2306篇
内科学   7078篇
皮肤病学   673篇
神经病学   2342篇
特种医学   583篇
外科学   3989篇
综合类   134篇
现状与发展   1篇
一般理论   6篇
预防医学   1990篇
眼科学   489篇
药学   1463篇
中国医学   61篇
肿瘤学   1608篇
  2023年   202篇
  2022年   390篇
  2021年   951篇
  2020年   436篇
  2019年   865篇
  2018年   1072篇
  2017年   598篇
  2016年   626篇
  2015年   736篇
  2014年   919篇
  2013年   1322篇
  2012年   2241篇
  2011年   2184篇
  2010年   1229篇
  2009年   1065篇
  2008年   1827篇
  2007年   1868篇
  2006年   1740篇
  2005年   1696篇
  2004年   1424篇
  2003年   1365篇
  2002年   1266篇
  2001年   137篇
  2000年   82篇
  1999年   143篇
  1998年   176篇
  1997年   156篇
  1996年   130篇
  1995年   132篇
  1994年   106篇
  1993年   98篇
  1992年   76篇
  1991年   68篇
  1990年   43篇
  1989年   37篇
  1988年   38篇
  1987年   40篇
  1986年   42篇
  1985年   45篇
  1984年   43篇
  1983年   25篇
  1982年   39篇
  1981年   45篇
  1980年   32篇
  1979年   34篇
  1978年   34篇
  1977年   24篇
  1976年   30篇
  1975年   21篇
  1974年   22篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Background: Zinc is an essential trace element for the normal growth and development of human beings. The main objective was to evaluate the nutritional status of zinc and its association with nutritional indicators in a series of children with chronic diseases. Methods: The prevalence of patients with dietary zinc deficiency or deficit zinc intake (<80% DRI: dietary reference intake) was analyzed through prospective 72 h dietary surveys, and serum zinc deficiency or hypozincemia (≤70 µg/dL in children under 10 years of age in both sexes and in females older than 10 years and <74 μg/dL in males older than 10 years) was measured through atomic absorption spectrophotometry. The participants were classified according to their nutritional status by body mass index (BMI). Results: Mean serum zinc level in obese (87 µg/dL), undernourished (85 µg/dL), and eutrophic children (88 µg/dL) were normal, but in the undernutrition (60% DRI) and eutrophic (67% DRI) groups the mean dietary zinc intake was low compared to that in the obesity group (81% DRI). There were different associations between nutritional parameters, dietary zinc intake, and serum zinc. All patients with hypozincemia had dietary zinc deficiency. Conclusions: In the whole series, 69% of participants showed a zinc intake lower than recommended and might be at high risk of zinc deficiency.  相似文献   
92.
Free-roaming camels, especially those crossing national borders, pose a high risk for spreading Middle East respiratory syndrome coronavirus (MERS-CoV). To prevent outbreaks, active surveillance is necessary. We found that a high percentage of dromedaries in Tunisia are MERS-CoV seropositive (80.4%) or actively infected (19.8%), indicating extensive MERS-CoV circulation in Northern Africa.  相似文献   
93.
Maternal and Child Health Journal - To identify and describe the frequency and characteristics of disrespect and abuse practices towards women during facility-based delivery in four hospitals in...  相似文献   
94.
95.
We report 3 cases of Puumala virus infection in a family in Switzerland in January 2019. Clinical manifestations of the infection ranged from mild influenza-like illness to fatal disease. This cluster illustrates the wide range of clinical manifestations of Old World hantavirus infections and the challenge of diagnosing travel-related hemorrhagic fevers.  相似文献   
96.
International Urology and Nephrology - To test the value of preoperative and postoperative cystatin C (CysC) as a predictor on kidney function after partial (PN) or radical nephrectomy (RN) in...  相似文献   
97.
Our purpose was to review and analyse the impact of pyrethroids and organophosphates exposure on human semen parameters. A comprehensive literature search was performed through MEDLINE via PubMed, Scopus and Webscience. Only cohort studies examining semen parameters in workers or general populations exposed to pyrethroids or organophosphates were included. Ejaculate volume, sperm count, concentration, motility, viability, normal morphology and seminal pH alterations were pooled using the Cochran–Mantel–Haenszel Method with the random effect model and expressed as weighted mean difference, risk ratios, 95% confidence intervals and p-values. Seven cross-sectional studies regarding pyrethroids were included. Four of them were eligible for meta-analysis. The only parameter affected by pyrethroid exposure was normal sperm morphology (WMD-7,61%, 95%CI –11,92 to −3,30;p = 0,0,005). Nine studies were selected to evaluate the impact of organophosphates on semen parameters with six of them eligible for meta-analysis. A significant reduction was detected for the following: ejaculate volume (WMD −0,47ml, 95%CI −0,69 to −0,25; p < 0,0001), sperm count (WMD-40,03, 95%CI −66,81 to −13,25;p = 0,003), concentration (WMD-13,69 x10⁶/mL, 95%CI −23, 27 to-4,12;p = 0,005) and motility (WMD −5,70%, 95%CI −12,89 to 1,50;p = 0,12). Despite the increase in sperm abnormality, it has been shown that pyrethroids are unrelated to reduced sperm quality. However, the negative association of organophosphates with spermatogenesis is noteworthy.  相似文献   
98.
BackgroundThe use of robotic-assisted total knee arthroplasty (TKA) has significantly increased over the past decade. Internet content is largely unregulated and may contain inaccurate and/or misleading information about robotic TKA. Our goal was to assess the content, quality, and readability of online material regarding robotic-assisted TKA.MethodsWe conducted an internet search for the top 50 web sites from each of the 3 most popular search engines (Google, Yahoo, and Bing) using the search term robotic total knee replacement. Each web site was assessed for content, quality, and readability. Web site quality was assessed utilizing the QUality Evaluation Scoring Tool (QUEST). Readability was assessed utilizing the Simple Measure of Gobbledygook, Flesch-Kincaid Grade Level, and Flesch Reading Ease Formula scores.ResultsGeneral risks of TKA were discussed in 47.2%, while benefits were discussed in 98.6% of all web sites. Inaccurate claims occurred at a significantly higher rate in physician/community hospital sources compared to university/academic web sites (59% vs 28%, P = .045). Web sites from university/academic web sites had the highest QUEST scores, while physician/community hospital sources scored the lowest (16.1 vs 10.6, P = .01). Most web sites were written at a college reading level or higher.ConclusionPatients should be counseled on the largely unregulated nature of online information regarding robotic-assisted TKA. Physicians and hospitals should consider revising the readability of their online information to a more appropriate level in order to provide accurate, evidence-based information to allow the patient to make an informed consent decision.  相似文献   
99.
In peritoneal dialysis (PD), a cloudy dialysate is an alarming finding. Bacterial peritonitis is the most common cause, however, atypical infections and non‐infectious causes must be considered. A 46‐year‐old man presented with asthenia, paraesthesia, foamy urine and hypertension. Laboratory testing revealed severe azotaemia, anaemia, hyperkalaemia and nephrotic‐range proteinuria. Haemodialysis was started through a central venous catheter. Later, due to patient preference, a Tenckhoff catheter was inserted. Conversion to PD occurred 3 weeks later, during hospitalization for a presumed central line infection. A month later, the patient was hospitalized for neutropenic fever. He was diagnosed an acute parvovirus infection and was discharged under isoniazid for latent tuberculosis. Four months later, the patient presented with fever and a cloudy effluent. Peritoneal fluid (PF) cytology was suggestive of infectious peritonitis, but the symptoms persisted despite antibiotic therapy. Bacterial and mycological cultures were negative. No neoplastic cells were detected. Mycobacterium tuberculosis eventually grew in PF cultures, despite previous negative molecular tests. Directed therapy was then initiated with excellent response. Thus, facing a cloudy effluent, one must consider multiple aetiologies. Diagnosis of peritoneal tuberculosis is hampered by the lack of highly sensitive and specific exams. Here, diagnosis was only possible due to positive mycobacterial cultures.  相似文献   
100.
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