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   390722篇
  免费   33332篇
  国内免费   10874篇
耳鼻咽喉   4540篇
儿科学   7621篇
妇产科学   5092篇
基础医学   26914篇
口腔科学   8904篇
临床医学   40582篇
内科学   53323篇
皮肤病学   3766篇
神经病学   14441篇
特种医学   9531篇
外国民族医学   25篇
外科学   40910篇
综合类   68038篇
现状与发展   29篇
一般理论   48篇
预防医学   39510篇
眼科学   2758篇
药学   40583篇
  684篇
中国医学   53812篇
肿瘤学   13817篇
  2024年   1691篇
  2023年   7499篇
  2022年   13937篇
  2021年   18446篇
  2020年   17930篇
  2019年   17586篇
  2018年   16050篇
  2017年   15158篇
  2016年   14701篇
  2015年   14191篇
  2014年   28812篇
  2013年   28669篇
  2012年   25015篇
  2011年   26912篇
  2010年   21651篇
  2009年   18917篇
  2008年   17381篇
  2007年   17758篇
  2006年   15117篇
  2005年   12970篇
  2004年   10519篇
  2003年   9190篇
  2002年   7254篇
  2001年   6311篇
  2000年   5231篇
  1999年   4312篇
  1998年   3500篇
  1997年   3141篇
  1996年   2754篇
  1995年   2508篇
  1994年   2325篇
  1993年   1913篇
  1992年   1753篇
  1991年   1610篇
  1990年   1416篇
  1989年   1332篇
  1988年   1209篇
  1987年   1042篇
  1986年   930篇
  1985年   2238篇
  1984年   2475篇
  1983年   1535篇
  1982年   1982篇
  1981年   1429篇
  1980年   1257篇
  1979年   1076篇
  1978年   901篇
  1977年   688篇
  1976年   819篇
  1975年   557篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
浅议中医理论的科学美   总被引:4,自引:0,他引:4  
科学美是美学形态分类中的一种 ,它从本质上反映事物运动的内在联系 ,属于美的深层形式。中医理论中存在简明、对称、新奇等科学美  相似文献   
122.
川芎嗪对肾缺血再灌注时c-fos bcl-2 ICAM-1蛋白表达的影响   总被引:1,自引:0,他引:1  
目的 探讨大鼠肾缺血再灌注损伤不同时间c -fos、细胞淋巴瘤 /白血病 - 2、细胞间粘附分子- 1蛋白的表达及川芎嗪对其影响。方法 用免疫组化法检测大鼠急性肾缺血再灌注不同时间内及川芎嗪干预后c -fos、细胞淋巴瘤 /白血病 - 2、细胞间粘附分子 - 1蛋白表达的分布及强度变化。结果 c -fos蛋白分布于近曲小管、远曲小管、集合管上皮细胞的细胞核、细胞浆内 ,再灌注后 1h表达明显增强 ,3h达高峰 ,6h锐减。细胞淋巴瘤 /白血病 - 2蛋白主要分布于近曲小管上皮细胞的细胞浆 ,再灌注后 1h表达明显增强 ,6h达高峰 ,2 4h仍有较强表达。细胞间粘附分子 - 1蛋白分布在肾血管、肾小管等部位 ,其中以肾血管为著 ,其表达增强于再灌注后 1h ,直到 2 4h仍有增高趋势。川芎嗪干预后c -fos、细胞间粘附分子 - 1蛋白表达明显下降 (P <0 0 1 )。细胞淋巴瘤 /白血病 - 2表达明显增高 (P <0 .0 1 )。结论 川芎嗪对肾缺血再灌注损伤有较好的保护作用  相似文献   
123.
OBJECTIVE: Failure after ileal pouch-anal anastomosis (IPAA) is reported with a frequency of 10-20%. The failed IPAA can be excised or defunctioned. Indications for excision and further management of an indefinitely diverted pouch are poorly described. The aim of the present investigation was to investigate pouch-related problems and the histopathological pattern of the pouch mucosa in this group of patients. METHOD: In a cohort of 620 patients having IPAA with a median follow-up of 14 years, 56 patients with failure were identified. The patients with defunctioned pouches were assessed with regard to pouch-related problems and endoscopy with biopsies was performed. Biopsies were stained with haematoxylin-eosin, PAS for neutral mucins and Alcian blue/high iron diamine for sialomucins/sulphomucins. Morphological changes were grouped into three types modified according to Veress and assessed for dysplasia. RESULTS: Twenty-two patients with an indefinitely diverted pouch were found. The follow-up time after surgery for failure was 10 years. Thirteen patients completed the follow-up. Except for two patients with pelvic/perineal pain, there were no clinical problems. The majority of patients displayed mild to moderate macroscopic signs of inflammation. Morphologically, findings ranged from a preserved mucosal pattern to intense inflammatory reaction. No case of dysplasia or carcinoma was found. CONCLUSION: Most patients with an indefinitely diverted pouch had no complaints regarding the pouch. There was no case of dysplasia. Indefinite diversion may be preferable to pouch excision, especially given the associated morbidity.  相似文献   
124.
目的:观察中药肾区皮肤外敷渗透加西药常规治疗高血压肾损害结果。方法:将部分中药粉碎微细化处理,将另部分中药液化处理.粉液混合装袋醋浸后外敷在肾区皮肤上,用药物导入仪肾区靶点式导人人体。并用一般西医常规治疗。结果:平均治疗3周血肌酐下降23%,BUN下降26%,24h蛋白尿下降23%,尿量增加16%,收缩压下降9%,舒张压下降7%。结论:中药的肾区皮肤外敷渗透加西医常规治疗效果明显高于一般常规治疗。  相似文献   
125.
OBJECTIVE: This study was designed to determine the relationship between interstitial cystitis (IC), endometriosis (endo), and chronic pelvic pain (CPP) in individuals in whom nongynecological and nonurological problems had been previously ruled out. METHODS: A prospective study of 162 consecutive women with a complaint of chronic pelvic pain seen in the clinic was performed between August 2002 and December 2005. These patients underwent a workup to exclude other causes of pelvic pain, had PUF (Pain Urgency and Frequency) questionnaires filled out, and underwent a laparoscopy and a cystoscopy with hydrodistention. Pain levels were determined, and treatment was reviewed and enumerated. Results were obtained and quantified. RESULTS: In this study, 123 (76%) patients were diagnosed with active endometriosis, 133 (82%) were diagnosed with interstitial cystitis, and 107 (66%) had both disease entities simultaneously. Thirteen (8%) patients were diagnosed with pathologies unrelated to endometriosis and interstitial cystitis. Pain levels were seen to decrease at 6 months in all groups of patients with the exception of those patients with endometriosis only. CONCLUSION: CPP is a difficult, taxing, and frustrating concern for many women in the United States. These individuals have traditionally been difficult to treat. A large number of women with CPP in our patient population have been shown to have endometriosis, interstitial cystitis, or both. Therefore, a workup for premenopausal individuals with CPP involves obtaining a history that keys into possible nongynecologic causes of pain, a complete accounting of urinary problems, and a thorough history of gynecological problems. A physical examination with a comprehensive history should be performed, and the investigation may include the possibility of a simultaneous laparoscopy and cystoscopy if warranted. These procedures can serve as both a means for diagnosis and treatment of these problems when encountered.  相似文献   
126.
Obesity is a risk factor for renal graft loss. Higher body mass index (BMI) in native kidneys is associated with glomerular hyperfiltration. Whether higher BMI in renal transplants is associated with hyperfiltration is unknown. We investigated the impact of BMI on renal hemodynamics 1 year post-transplant. We analyzed glomerular filtration rate (GFR, (125)I-iothalamate) and effective renal plasma flow (ERPF, (131)I-hippurate) in 838 kidney transplants. Data were analyzed for all patients and for the subpopulation without diabetes. Long-term impact of BMI and renal hemodynamics were explored by Cox-regression. With higher BMI GFR and filtration fraction (FF) increased significantly. Multivariate analysis supported impact of BMI on GFR (adjusted r(2) of the model 0.275) and FF (adjusted r(2) of the model 0.158). This association was not explained by diabetes mellitus. On Cox-regression analysis, lower GFR and higher FF were independent determinants of overall graft loss and graft loss by patient mortality. Lower GFR and higher BMI were determinants of death-censored graft loss, with borderline contribution of higher FF. In renal transplants higher BMI is independently associated with higher GFR and FF one year posttransplant, suggesting glomerular hyperfiltration with altered afferent-efferent balance. Mechanisms underlying the long-term prognostic impact of hyperfiltration deserve further exploration.  相似文献   
127.
BACKGROUND: Microalbuminuria and macroalbuminuria constitute risk factors for ESRD and death in non-transplanted populations. Whether microalbuminuria (especially in non-proteinuric patients) and macroalbuminuria constitute risk factors for graft loss and death is presently unknown in renal transplantation. METHODS: We retrospectively assessed the association between urinary albumin excretion (UAE) and ESRD and death in renal transplantation. RESULTS: UAE was measured in 616 (397 proteinuric; 219 non-proteinuric patients) renal transplant recipients. They were grafted for 62 months (range: 6-192). During the 40 months (3.7-99) thereafter, 31 patients underwent dialysis and 32 died. Microalbuminuria (vs. normoalbuminuria) and macroalbuminuria (vs. microalbuminuria) were powerful risk factors for graft loss [OR: 14.25 (2.88-52.3) and 16.41 (7.46-36.0), respectively, both p < 0.0001], even after adjustments on renal function and diabetes. Among the 219 non-proteinuric patients, microalbuminuria (vs. normoalbuminuria) was a significant risk factor for graft loss [OR: 23.09 (1.93-276.4), p = 0.0132]. Both microalbuminuria (vs. normoalbuminuria) [OR: 5.55 (2.43-12.66), p < 0.0001] and macroalbuminuria (vs. microalbuminuria) [OR: 4.12 (1.65-10.29), p = 0.0024] were predictive of death. CONCLUSIONS: Microalbuminuria and macroalbuminuria are powerful independent predictors of ESRD and death. Microalbuminuria is a risk factor for graft loss even in non-proteinuric patients. UAE provides additional information on renal and patient prognosis as compared to proteinuria and renal function.  相似文献   
128.
Flavocoxid (Limbrel), a proprietary mixture of flavonoid molecules (baicalin and catechin), was tested against a traditional nonsteroidal anti-inflammatory drug, naproxen, for the management of the signs and symptoms of moderate osteoarthritis (OA) in humans. Discomfort and global disease activity were used as the primary end points, and safety assessments were also taken for both treatments as a secondary endpoint. In this double-blind study, 103 subjects were randomly assigned to receive either flavocoxid [500 mg twice daily (BID)] or naproxen (500 mg BID) in a 1-month onset of action trial. Outcome measures included the short Western Ontario and McMaster University Osteoarthritis Index, subject Visual Analogue Scale for discomfort and global response, and investigator Visual Analogue Scale for global response and fecal occult blood. Both flavocoxid and naproxen showed significant reduction in the signs and symptoms of knee OA (P ≤ .001). There were no statistically detectable differences between the flavocoxid and naproxen groups with respect to any of the outcome variables. Similarly, there were no statistically detectable differences between the groups with respect to any adverse event, although there was a trend toward a higher incidence of edema and nonspecific musculoskeletal discomfort in the naproxen group. In this short-term pilot study, flavocoxid was as effective as naproxen in controlling the signs and symptoms of OA of the knee and would present a safe and effective option for those individuals on traditional nonsteroidal anti-inflammatory drugs or cyclooxygenase-2 inhibitors. A low incidence of adverse events was reported for both groups.  相似文献   
129.
Acute encephalopathy associated with influenza and other viral infections   总被引:7,自引:0,他引:7  
Acute encephalopathy is the most serious complication of pediatric viral infections, such as influenza and exanthem subitum. It occurs worldwide, but is most prevalent in East Asia, and every year several hundreds of Japanese children are affected by influenza-associated encephalopathy. Mortality has recently declined, but is still high. Many survivors are left with motor and intellectual disabilities, and some with epilepsy. This article reviews various syndromes of acute encephalopathy by classifying them into three major categories. The first group caused by metabolic derangement consists of various inherited metabolic disorders and the classical Reye syndrome. Salicylate is a risk factor of the latter condition. The second group, characterized by a systemic cytokine storm and vasogenic brain edema, includes Reye-like syndrome, hemorrhagic shock and encephalopathy syndrome, and acute necrotizing encephalopathy. Non-steroidal anti-inflammatory drugs, such as diclofenac sodium and mephenamic acid, may aggravate these syndromes. Severe cases are complicated by multiple organ failure and disseminated intravascular coagulation. Mortality is high, although methylprednisolone pulse therapy may be beneficial in some cases. The third group, characterized by localized edema of the cerebral cortex, has recently been termed acute encephalopathy with febrile convulsive status epilepticus, and includes hemiconvulsion-hemiplegia syndrome and acute infantile encephalopathy predominantly affecting the frontal lobes. Theophylline is a risk factor of these syndromes. The pathogenesis is yet to be clarified, but an increasing body of evidence points to excitotoxicity and delayed neuronal death.  相似文献   
130.
Abstract Calcaneal fracture is the most common of the tarsal fractures and represents 1%–2% of all fractures. The fractures may be divided into extra-articular (not affecting the joint) and intra-articular (involving the talo-calcaneal and calcaneal cuboid joints) types. The management of heel fractures includes nonoperative and operative treatments, but no clear consensus has been reached. The choice of operative treatment is still controversial with many factors influencing the final clinical outcome. Many studies have assessed the outcome of treatment of calcaneal fractures, but there is a general disagreement on their management. The objective of this study was to collect and evaluate the scientific evidence reported in the literature supporting the different treatments for calcaneal fractures.  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