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   4624篇
  免费   307篇
  国内免费   23篇
耳鼻咽喉   32篇
儿科学   183篇
妇产科学   95篇
基础医学   774篇
口腔科学   62篇
临床医学   325篇
内科学   838篇
皮肤病学   67篇
神经病学   324篇
特种医学   81篇
外科学   503篇
综合类   120篇
现状与发展   1篇
一般理论   4篇
预防医学   388篇
眼科学   149篇
药学   533篇
中国医学   73篇
肿瘤学   402篇
  2023年   28篇
  2022年   65篇
  2021年   118篇
  2020年   80篇
  2019年   109篇
  2018年   133篇
  2017年   87篇
  2016年   106篇
  2015年   137篇
  2014年   171篇
  2013年   257篇
  2012年   333篇
  2011年   356篇
  2010年   213篇
  2009年   151篇
  2008年   254篇
  2007年   239篇
  2006年   281篇
  2005年   222篇
  2004年   184篇
  2003年   143篇
  2002年   152篇
  2001年   99篇
  2000年   101篇
  1999年   63篇
  1998年   41篇
  1997年   27篇
  1996年   16篇
  1995年   17篇
  1994年   17篇
  1993年   16篇
  1992年   55篇
  1991年   54篇
  1990年   49篇
  1989年   57篇
  1988年   39篇
  1987年   32篇
  1986年   30篇
  1985年   39篇
  1984年   28篇
  1983年   32篇
  1981年   15篇
  1980年   22篇
  1979年   33篇
  1978年   17篇
  1977年   22篇
  1976年   15篇
  1974年   17篇
  1973年   18篇
  1972年   15篇
排序方式: 共有4954条查询结果,搜索用时 171 毫秒
1.
2.
BACKGROUND: Penetrating injuries of the perineum are rare but very dangerous. Since the genitourinary and colorectal organs may be injured, how to evaluate surgical management of the injury is very important.METHODS: The present report presents a case of penetrating injury of the perineum by a wooden stick when the patient fell on the upright wooden stick from a tree. The three feet long stick entered the perineal region just left lateral to the anal opening. Upon reaching the thoracic cavity, it broke and only a foot stick was left in the subcutaneous plane. These injuries are potentially serious with risk of damage to multiple organs. Exploratory laprotomy was done, and bladder injury was repaired. The entry wound and the track of stick was thoroughly washed and allowed for secondary intention healing.RESULTS: The post operative period was uneventful and the patient recovered fully.CONCLUSION: Meticulous evaluation and surgical management of perineal injuries are the key to prevent devastating complications.  相似文献   
3.
ObjectivesSevere acute kidney injury (AKI) is a known risk factor for infection and mortality. However, whether stage 1 AKI is a risk factor for infection has not been evaluated in adults. We hypothesized that stage 1 AKI following cardiac surgery would independently associate with infection and mortality.MethodsIn this retrospective propensity score–matched study, we evaluated 1620 adult patients who underwent nonemergent cardiac surgery at the University of Colorado Hospital from 2011 to 2017. Patients who developed stage 1 AKI by Kidney Disease Improving Global Outcomes creatinine criteria within 72 hours of surgery were matched to patients who did not develop AKI. The primary outcome was an infection, defined as a new surgical-site infection, positive blood or urine culture, or development of pneumonia. Secondary outcomes included in-hospital mortality, stroke, and intensive care unit (ICU) and hospital length of stay (LOS).ResultsStage 1 AKI occurred in 293 patients (18.3%). Infection occurred in 20.9% of patients with stage 1 AKI compared with 8.1% in the no-AKI group (P < .001). In propensity-score matched analysis, stage 1 AKI independently associated with increased infection (odds ratio [OR]; 2.24, 95% confidence interval [CI], 1.37-3.17), ICU LOS (OR, 2.38; 95% CI, 1.71–3.31), and hospital LOS (OR, 1.30; 95% CI, 1.17-1.45).ConclusionsStage 1 AKI is independently associated with postoperative infection, ICU LOS, and hospital LOS. Treatment strategies focused on prevention, early recognition, and optimal medical management of AKI may decrease significant postoperative morbidity.  相似文献   
4.
OBJECTIVE: To analyse morbidity after completion total thyroidectomy compared with primary total thyroidectomy in a specialist thyroid surgery centre. DESIGN: Retrospective study. SETTING: Tertiary referral hospital, India. PATIENTS: Medical records of 143 patients who had total thyroidectomy between January 1990 and December 1999. 95 had primary thyroidectomies and 48 were completion thyroidectomies. MAIN OUTCOME MEASURES: Complication rate in both groups. RESULTS: The groups were comparable in respect of clinicopathological variables. Residual tumour was found in 19/48 (40%). After completion thyroidectomy, transient hypoparathyroidism and transient recurrent laryngeal nerve palsy were recorded in 8/48 (17%) and 2/48 (4%), respectively. No permanent hypoparathyroidism or permanent recurrent laryngeal nerve palsy was recorded in the completion thyroidectomy group. CONCLUSIONS: Completion thyroidectomy can be done with acceptable morbidity in a specialist thyroid surgery centre. Fear of increased morbidity after the procedure should not deter surgeon from doing this operation or referring the patients to a specialist centre.  相似文献   
5.
We have studied the effects of semi-synthetic diets rich in either n-9 (olive oil, OO) or n-6 (corn oil, CO), or n-3 (fish oil, FO, as MaxEPA) fatty acids on the levels of major PUFA in platelet lipids, on the generation of inositol phosphates by [3H]inositol labelled platelets after stimulation with thrombin and of thromboxane B2 (TxB2) by platelet rich plasma (PRP) after stimulation with collagen. The predicted elevations of oleic (OA), linoleic (LA) and eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids were observed in platelet lipids of each animal group, but in the MaxEPA fed group accumulation of EPA was associated with depletion of linoleic acid (LA) rather than of arachidonic acid (AA). Basal levels of inositol-tris-phosphate (IP3) in platelets were lowest in the OO group and highest in the CO group, whereas the increment after thrombin stimulation (1 unit/ml NIH) was maximal in the OO group and minimal in the FO group. Instead, when generation of TxB2 by stimulated platelets was evaluated, no appreciable difference among the various groups could be detected, in accordance with the limited modifications of platelet AA content induced by the diets. The overall data indicate that dietary fatty acids modulate the pathway of inositol phosphate generation in rabbit platelets, independently of modifications of TxB2 production.  相似文献   
6.
A rare case of an advanced primary broad ligament carcinoma is discussed, with a review of the literature regarding its incidence, presentation and management. This patient showed a complete response to adjuvant cisplatin-based chemotherapy following panhysterectomy and is presently without any evidence of disease, 15 months after completion of her treatment.  相似文献   
7.
Supplementation of the diet of adult male rats with 4,000 ppm zinc as ZnSO4 for 30 to 32 days increased the zinc content in the testis and sperm by 25 and 18 per cent respectively, but did not change the same in accessory reproductive tissues, e.g. epididymis, seminal vesicle and prostate. The incidence of conception from mating between normal females and zinc fed males was lower as compared to mating between normal females and control males. This observation indicated reduced fertility of the males resulting from additional zinc ingestion. Motility of the sperm collected from the epididymis (tail) of the zinc treated rats was found to be inhibited. It has been suggested that excess zinc in the sperm was responsible for their poor motility and hence a reduced fertilising capacity.  相似文献   
8.
The methanolic fraction of P. indica root extract was found to possess significant antiulcer activity in different experimental animal models. In preventive antiulcer tests, significant protective actions in acetylsalicylic acid, serotonin and indomethacin-induced gastric lesions were observed in experimental rats. The extract also afforded significant protection to chemically-induced duodenal lesion in guineapigs. Significant enhancement of healing process in acetic acid-induced chronic gastric lesions were also observed in the extract-treated animals.  相似文献   
9.
Chymase is known to generate angiotensin II in the vascular wall. In this study we investigated a novel role for chymase other than angiotensin II production in vascular proliferation after balloon injury. Chymase promoted the migration of vascular smooth muscle cells in the matrix-coated invasion chambers and activated promatrix metalloproteinase-2 obtained from the culture medium of vascular smooth muscle cells. Two weeks after balloon injury, significant neointimal formation was found in dog carotid arteries. After injury, active matrix metalloproteinase-2 was increased in parallel with the augmentation of chymase activity that was seen in the proliferating region of the vascular wall. The oral administration of NK3201 (1 mg/kg per day), a chymase inhibitor, prevented neointimal formation and significantly suppressed both active matrix metalloproteinase-2 and chymase activities 2 weeks after injury. These results suggest that chymase inhibitors can prevent the development of intimal hyperplasia via the inhibition of matrix metalloproteinase-2 activation in balloon-injured arteries.  相似文献   
10.
Summary Primary presentation of an intradural Non-Hodgkin’s lymphoma is rare. Recently these B cell lymphomas of mucosa associated lymphoid tissue (MALT) have gained acceptance as an important pathological subtype and are distinguishable from other primary CNS lymphomas that exhibit aggressive behaviour. Over the past decade a number of these lesions have been reported to resemble a meningioma both intra-operatively and radiologically. The authors outline such a case of marginal zone B cell lymphoma that clinically and radiologically resembled a meningioma. This case illustrates the rare occurrence of low grade dural B cell lymphoma and the need to consider this entity in the differential diagnosis of CNS lesions, if appropriate targeted therapy is to be administered.  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