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   1857篇
  免费   81篇
  国内免费   7篇
耳鼻咽喉   24篇
儿科学   34篇
妇产科学   37篇
基础医学   237篇
口腔科学   148篇
临床医学   108篇
内科学   373篇
皮肤病学   30篇
神经病学   293篇
特种医学   51篇
外科学   219篇
综合类   6篇
一般理论   1篇
预防医学   86篇
眼科学   94篇
药学   98篇
中国医学   19篇
肿瘤学   87篇
  2023年   14篇
  2022年   16篇
  2021年   49篇
  2020年   21篇
  2019年   42篇
  2018年   41篇
  2017年   23篇
  2016年   38篇
  2015年   59篇
  2014年   62篇
  2013年   95篇
  2012年   163篇
  2011年   160篇
  2010年   80篇
  2009年   80篇
  2008年   151篇
  2007年   113篇
  2006年   118篇
  2005年   105篇
  2004年   89篇
  2003年   92篇
  2002年   74篇
  2001年   36篇
  2000年   20篇
  1999年   30篇
  1998年   16篇
  1997年   13篇
  1996年   11篇
  1995年   3篇
  1994年   5篇
  1993年   8篇
  1992年   8篇
  1991年   9篇
  1990年   7篇
  1989年   8篇
  1988年   13篇
  1987年   8篇
  1986年   3篇
  1985年   5篇
  1984年   3篇
  1983年   6篇
  1980年   5篇
  1979年   10篇
  1978年   3篇
  1977年   3篇
  1976年   5篇
  1973年   5篇
  1972年   2篇
  1971年   3篇
  1970年   4篇
排序方式: 共有1945条查询结果,搜索用时 15 毫秒
141.
The clinical and epidemiological features, as well as complications presented by 39 patients with Bothrops, Porthidium and Bothriechis snakebites, are described. Patients were admitted during 1 year in 25 hospitals of Antioquia and Chocó and then, they were transferred to the Hospital Universitario San Vicente de Paúl in Medellín, 30 of them because of the presence of complications, eight because of lack of antivenoms and another one because of the desire of his relatives. Thirty--one (79.5%) of the patients were male, 13 (33.3%) children, 59% of them were bitten at the lower extremities, the majority (74.4%) by Bothrops asper. Twenty-one (53.8%) of the patients were initially attended by traditional healers and sought medical attention at the local hospitals after 2h in 87.2% of the cases. Edema (100%), hemorrhage (74.4%), blistering (38.5%) and necrosis (38.5%), were the local signs of envenomation, while blood coagulation alteration (79.5%), hematuria (74.4%), gingival bleeding (43.6%), hypovolemic shock (23.1%) and oliguria (23.1%), were the systemic signs of envenomation. The final grade of envenomation was severe in 29 patients (74.4%). Thirty patients (76.9%) had one or more complications of the envenomation: acute renal failure (ARF), 15 (38.5%); soft-tissue infection, 12 (30.8%); central nervous system (CNS) hemorrhage, 5 (12.8%); compartment syndrome, 3 (7.7%); soft--tissue hematomas, 6 (15.4%); and Abruptio placentae, one (2.6%). There were four deaths (10.3%), two from ARF and two from cerebral hemorrhage. Fourteen other patients (35.9%) had sequelae. The onset of serotherapy after 2h of the bite was associated with the occurrence of ARF and CNS hemorrhage (p=0.02), as well as the risk of death and sequelae (RR=2.5).  相似文献   
142.
143.
144.
The consumption of alcohol or nicotine is harmful to the integrity of bone tissue, hindering or even impeding the fixation and maintenance of bone implants. The aim of the present work was to evaluate the effects of ethanol and nicotine, when consumed alone and simultaneously, on both bone mechanical resistance and bone neoformation around hydroxyapatite implants. Twenty rats were divided into four groups: control (CT), alcohol (A), nicotine (N) and nicotine + alcohol (N + A). After 4 weeks of alcohol and/or nicotine consumption, dense (HAD) and porous (HAP) bodies were respectively implanted in a surgically produced bone defect in the right and left tibiae. After the surgeries, the animals continued to consume alcohol and/or nicotine. After ninety days, the animals were sacrificed and the tibiae and femurs were isolated for histological processing and mechanical assays. All the animals presented newly formed bone tissue close to the HAD and HAP ceramic bodies. The animals of the N + A group presented a smaller volume of neoformed bone. Group A animals presented smaller bone volume around the implants in relation to the animals from group N. Bone resistance to mechanical loads was smallest in animals from the N + A group, followed (in order) by the A and N groups. Thus, it can be concluded that nicotine or alcohol consumption produced negative effects on bone mechanical resistance and on the osteogenesis around the HAD and HAP implants. In addition, the simultaneous consumption of the two substances intensified their harmful effects.  相似文献   
145.
146.
Objective: To determine the degree of knowledge that cardiologists from São Paulo, Brazil, have regarding a low‐prevalent entity associated with a high rate of sudden death—Brugada syndrome. Methods: Two hundred forty‐four cardiologists were interviewed by an instrument divided in two parts: in the first, we recorded gender, age, and data related to academic profile. The second—answered only by the professionals that manifested having some degree of knowledge on the syndrome—had 28 questions that evaluated their knowledge. The answers were spontaneous and they did not have a chance to consult. We used uni‐ and multivariate analysis on the average percentage of right and wrong answers, and the influence of the academic profile. Results: The predominant gender was the male gender (61.1%), the average age was 44.32 ± 10.83 years, 40% with more than 20 years after obtaining their degree, 44% were educated in public institutions, 69% had a residency in cardiology, 20% had overseas practice, 12% had postdegree, 41% were linked to an educational institution, 24% with publication(s) in an indexed journal, 17.2% were authors of chapters in books, 2.5% had edited books, and 10% were linked to the Brazilian Society of Cardiac Arrhythmias. The average percentage of right answers was 45.7%. Conclusion: The sample studied revealed a little knowledge on the entity. A residency in cardiology was the factor of greater significance in the percentage of right answers. Other significant factors were the link of the interviewed person to an educational institution, or the Brazilian Society of Cardiac Arrhythmias, and having a specialist degree.  相似文献   
147.
Sonographic demonstration of abdominal venous thromboses subsequent to pancreatic benign inflammatory diseases has been seldom reported up to now. Seven cases of thromboses of the portal venous system associated with acute or chronic pancreatitis are reported. All cases were detected by sonography in patients without clinical manifestations of portal hypertension. Echogenic thrombus within the lumen of the vein was observed only in the short-term follow-up of acute pancreatitis. Cavernomatous transformation was observed in 6 patients with long-term calcifying pancreatitis. Extrinsic compression by pseudocyst of the pancreas was observed in only 1 case. In all the other cases, thromboses seems to be secondary to local inflammatory phenomena during previous episodes of acute pancreatitis.  相似文献   
148.
The aim of our study was to evaluate the benefits of supplementation with 800 mg/day of alpha-tocopherol with regard to cellular viability in HIV-1 seropositive patients undergoing anti-retroviral therapy. A total of 29 patients participated in the study, of whom 14 were given the supplement and 15 a placebo. The analyses were carried out before treatment commenced and after 60, 120 and 180 days. The plasma levels of HIV-1 RNA showed a significant decrease as a consequence of treatment time in the groups studied (p = 0.0001), although the difference between the treatments over time was not verified (p = 0.7343). The percentage of viable lymphocytes showed a significant increase as a consequence of treatment time in both groups studied (p = 0.0002) and a significant difference between the treatments over time (p = 0.0472). The percentage of lymphocytes in apoptosis showed a significant reduction over time (p = 0.0003), as well as a significant difference between the treatments over time (p = 0.0321). The significant increase in cellular viability indicates that supplementation with alpha-tocopherol offers an additional positive effect on cellular preservation in HIV-1 individuals undergoing anti-retroviral therapy; however, it represents an additional risk of anti-retroviral therapeutic failure, possibly due to drug-drug interaction involving up-regulation of metabolic clearance.  相似文献   
149.
150.
Obesity represents a continuously growing global epidemic and is associated with the development of type 2 diabetes mellitus. The etiology of type 2 diabetes is related to the resistance of insulin-sensitive tissues to its action leading to impaired blood glucose regulation. Photobiomodulation (PBM) therapy might be a non-pharmacological, non-invasive strategy to improve insulin resistance. It has been reported that PBM therapy in combination with physical exercise reduces insulin resistance. Therefore, the aim of this study was to investigate the effects of PBM therapy on insulin resistance in obese mice. Male Swiss albino mice received low-fat control diet (n?=?16, LFC) or high-fat diet (n?=?18, HFD) for 12 weeks. From 9th to 12th week, the mice received PBM therapy (LASER) or Sham (light off) treatment and were allocated into four groups: LFC Sham (n?=?8), LFC PBM (n?=?8), HFD Sham (n?=?9), and HFD PBM (n?=?9). The PBM therapy was applied in five locations: to the left and right quadriceps muscle, upper limbs and center of the abdomen, during 40 s at each point, once a day, 5 days a week, for 4 weeks (780 nm, 250 mW/cm2, 10 J/cm2, 0.4 J per site; 2 J total dose per day). Insulin signaling pathway was evaluated in the epididymal adipose tissue. PBM therapy improved glucose tolerance and phosphorylation of Akt (Ser473) and reversed the HFD-induced reduction of GLUT4 content and phosphorylation of AS160 (Ser588). Also, PBM therapy reversed the increased area of epididymal and mesenteric adipocytes. The results showed that chronic PBM therapy improved parameters related to obesity and insulin resistance in HFD-induced obesity in mice.  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