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   76838篇
  免费   5862篇
  国内免费   384篇
耳鼻咽喉   1007篇
儿科学   2186篇
妇产科学   1666篇
基础医学   10731篇
口腔科学   1255篇
临床医学   8772篇
内科学   14314篇
皮肤病学   2039篇
神经病学   7077篇
特种医学   2605篇
外科学   8599篇
综合类   533篇
现状与发展   4篇
一般理论   94篇
预防医学   8058篇
眼科学   1336篇
药学   6060篇
中国医学   486篇
肿瘤学   6262篇
  2024年   82篇
  2023年   720篇
  2022年   1545篇
  2021年   2898篇
  2020年   1686篇
  2019年   2591篇
  2018年   2831篇
  2017年   2208篇
  2016年   2641篇
  2015年   3123篇
  2014年   3855篇
  2013年   4861篇
  2012年   7165篇
  2011年   6888篇
  2010年   3918篇
  2009年   3172篇
  2008年   5097篇
  2007年   4842篇
  2006年   4398篇
  2005年   4123篇
  2004年   3483篇
  2003年   2957篇
  2002年   2537篇
  2001年   615篇
  2000年   526篇
  1999年   525篇
  1998年   444篇
  1997年   341篇
  1996年   260篇
  1995年   223篇
  1994年   184篇
  1993年   162篇
  1992年   177篇
  1991年   175篇
  1990年   158篇
  1989年   147篇
  1988年   124篇
  1987年   101篇
  1986年   103篇
  1985年   86篇
  1984年   79篇
  1983年   74篇
  1982年   42篇
  1981年   44篇
  1980年   44篇
  1979年   63篇
  1978年   57篇
  1975年   68篇
  1972年   50篇
  1971年   56篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
191.
192.
OBJECTIVE: Patients on L-thyroxine with a 'suppressed' TSH (< 0.05 mU/l) were compared to those in whom TSH was detectable but not elevated (0.05-4.0 mU/l), with regard to morbidity data. DESIGN: Biochemical data from Tayside Thyroid Register was matched to hospital admissions data obtained from Health Board Statistics. PATIENTS: The patients were identified from those registered on the computerized Tayside Register. MEASUREMENTS: Serum T4 and TSH assays, clinical assessment scores, and admission records with regard to ischaemic heart disease, overall fractures, fractured neck of femur and breast carcinoma. RESULTS: Over one year, 1180 patients on thyroxine replacement had clinical and biochemical assessment; 59% had a suppressed TSH and 38% 'normal' TSH. Patients with a suppressed TSH exhibited higher median serum thyroxine levels (146 nmol/l, range 77-252 vs 119 nmol/l, 58-224; P < 0.001). Patients under the age of 65 years on L-thyroxine had an increased risk of ischaemic heart disease compared to the general population (female 2.7 vs 0.7%, P < 0.001; male 6.4 vs 1.7%, P < 0.01), but the risk was no different between those with suppressed and normal TSH. There was no increase in risk for overall fracture, fractured neck of femur or breast carcinoma in those on thyroxine with suppressed or normal TSH. CONCLUSION: Patients under the age of 65 years on L-thyroxine had an increased risk of ischaemic heart disease. There was no excess of fractures in patients on L-thyroxine even if the TSH is suppressed.  相似文献   
193.
194.
195.
BACKGROUND/AIMS: Bamboo joint-like (BJL) appearance is an endoscopic finding characterized by swollen longitudinal folds transversed by erosive fissures or linear furrows on the lesser curvature side of gastric body and cardia. It has been reported to be associated with Crohn's disease (CD). This study was aimed to evaluate the incidence of BJL appearance in Korean patients with CD. METHODS: From January to December in 2005, we performed esophagogastroduodenoscopy (EGD) in patients diagnosed as CD and ulcerative colitis (UC) in our hospital. Non-inflammatory bowel disease (IBD) subjects with upper gastrointestinal symptoms who underwent EGD were consecutively enrolled during the same period. One endoscopist performed all the endoscopic examinations to avoid inter-observer variation. A dye-spraying technique with 0.4% indigocarmine was used to allow the detection of subtle changes during the endoscopic examination. RESULTS: A total of 21 patients with CD (mean age+/-SD, 40+/-15 yr; M/F, 13/8), 28 patients with UC (42+/-15 yr; 21/7), and 685 non-IBD subjects (49+/-14 yr; 354/331) were enrolled. EGD findings in CD patients were gastric erosions (11/21), chronic superficial gastritis (5/21), chronic atrophic gastritis (1/21), duodenal erosions or ulcers (2/21), and normal (2/21). Incidence of BJL appearance was significantly higher in patients with CD (47.6%, 10/21) than others (UC, 3.6%, 1/28; non-IBD, 0.1%, 1/685) (p< 0.0001). Among patients with CD, incidence of BJL appearance was not significantly different according to the sex, status of H. pylori infection, Vienna classification for phenotype, medications or EGD findings. CONCLUSIONS: BJL appearance on the gastric body and cardia can be a diagnostic clue to CD.  相似文献   
196.
PURPOSE: Efficacy and safety data regarding the unlabeled uses of botulinum toxins are reviewed, and the pharmacology, adverse effects, and characteristics of commercially available botulinum toxins are discussed. SUMMARY: More than 300 articles have been published on the use of botulinum toxins, particularly botulinum toxin type A, to treat conditions characterized by excessive smooth or skeletal muscle spasticity. Botulinum toxins are synthesized by Clostridium botulinum and cause temporary local paralysis of the injected muscle by inhibiting acetylcholine release at the neuromuscular junction. While botulinum toxins have Food and Drug Administration-approved labeling to treat a limited number of spasticity disorders, including cervical dystonia and blepharospasm, the toxins have more than 50 reported therapeutic uses. Among these uses, the most rigorously studied indications include achalasia, essential tremors, palmar hyperhidrosis, chronic anal fissures, headache prophylaxis, and limb spasticity. The main adverse effects of the toxins are pain and erythema at the injection site, although unintended paralysis of muscles adjacent to the site of toxin injection may also occur. CONCLUSION: Clinical studies support the use of botulinum toxins for certain conditions, although more studies are needed to establish the role of the drug relative to conventional therapies and to determine patient predictors of response. Although botulinum toxins are generally well tolerated, a patient-specific risk-benefit assessment should precede any decision to use them for unlabeled indications.  相似文献   
197.
The development of Lisch nodules in an eye that had undergone trabeculectomy with mitomycin C is described. Complete ophthalmologic examinations and genetic testing of a 12-year-old boy were performed. Lisch nodules can develop after trabeculectomy without the systemic manifestations of neurofibromatosis type 1.  相似文献   
198.
In contrast to other types of congenital heart defects, the treatment of hypoplastic left heart syndrome (HLHS) has become comparably successful only within the last decade. Postnatal management of circulatory disturbances of HLHS was previously often performed, similarly to other types of neonatal shock, without considering the peculiarities of postnatal hemodynamics. It is of overwhelming importance to limit pulmonary hyperperfusion by reducing systemic afterload and avoiding artificial respiration. The invention of selective hypothermic cerebral perfusion using the modified Blalock-Taussig shunt has decreased the need for long circulatory arrest times involving the brain, and promises a better neurological outcome. Postoperatively, sophisticated hemodynamic monitoring is mandatory to provide sufficient systemic oxygen delivery. α-blockers are usually given for strong afterload reduction. Hospital mortality is as low as 10–15% in centers experienced with the Norwood operation. The next surgical steps to create a serial systemic and pulmonary circulation involve superior cavopulmonary anastomosis performed as early as possible (4–6 months) and finally total cavopulmonary connection at an age of 3–4 years.  相似文献   
199.
Mark Raderstorf  Jennifer Kurtz 《AAOHN journal》2006,54(8):360-5; quiz 366-7
Occupational health nurses must intervene early and validate the conditions and experiences of employees with psychiatric disabilities. Occupational health nurses must ensure employees are receiving appropriate treatment. They must be aware of and prepared to mitigate iatrogenic influences. Occupational health nurses can facilitate resolution of workplace conflicts and issues regarding changing supervisors or departments. They can also facilitate return to work by establishing clear restrictions and coordinating accommodations. compassionate and supportive, yet assertive, approach is key to managing mental health disability. It will, in most cases, facilitate successful return to full-time work.  相似文献   
200.
3-Monochloro-1,2-propanediol (MCPD) is a well-known by-product of acid-hydrolyzed soy sauce during its manufacturing process. MCPD has been reported genotoxic in vitro, and reproductive toxicity and carcinogenicity in rats. To evaluate the immunomodulatory effect of MCPD on murine splenocyte and macrophage in vitro, we investigated splenocyte blastogenesis by concanavalin A (Con A), anti-CD3, and lipopolyssacharide (LPS), the production of cytokines from splenocyte, and the activity of mouse peritoneal macrophages. There was a significant decrease in lymphocyte blastogenesis to Con A or anti-CD3 at subtoxic dose of MCPD. A significant decrease in splenocyte blastogenesis to LPS was also observed. The production level of interferon (IFN)-gamma on splenocyte culture with Con A was significantly reduced at the higher concentration than 1.0mM of MCPD. The levels of interleukin (IL)-4 and IL-10 were also decreased at high concentrations of MCPD. There was a significant decrease in production of nitric oxide (NO) by peritoneal macrophages treated with MCPD. MCPD also inhibits tumor necrosis factor (TNF)-alpha production of stimulated macrophages. These results indicate that MCPD might be able to reduce the functionality of lymphocytes and peritoneal macrophages in vitro.  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