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   1095篇
  免费   81篇
  国内免费   10篇
耳鼻咽喉   8篇
儿科学   51篇
妇产科学   23篇
基础医学   128篇
口腔科学   20篇
临床医学   86篇
内科学   242篇
皮肤病学   30篇
神经病学   122篇
特种医学   163篇
外科学   84篇
综合类   44篇
一般理论   1篇
预防医学   42篇
眼科学   13篇
药学   94篇
中国医学   7篇
肿瘤学   28篇
  2023年   7篇
  2021年   10篇
  2019年   10篇
  2018年   21篇
  2017年   6篇
  2016年   29篇
  2015年   54篇
  2014年   24篇
  2013年   34篇
  2012年   34篇
  2011年   40篇
  2010年   40篇
  2009年   38篇
  2008年   33篇
  2007年   34篇
  2006年   34篇
  2005年   36篇
  2004年   31篇
  2003年   26篇
  2002年   19篇
  2001年   24篇
  2000年   23篇
  1999年   19篇
  1998年   30篇
  1997年   48篇
  1996年   39篇
  1995年   29篇
  1994年   23篇
  1993年   21篇
  1992年   19篇
  1991年   28篇
  1990年   26篇
  1989年   35篇
  1988年   32篇
  1987年   20篇
  1986年   30篇
  1985年   22篇
  1984年   24篇
  1983年   17篇
  1982年   11篇
  1981年   8篇
  1980年   10篇
  1979年   5篇
  1978年   5篇
  1977年   8篇
  1976年   9篇
  1973年   6篇
  1970年   7篇
  1969年   4篇
  1967年   5篇
排序方式: 共有1186条查询结果,搜索用时 31 毫秒
131.
132.
The authors report the case of a patient treated by salazosulfapyridine and presenting with hepatitis and mononucleosis. The clinical pattern was similar to infectious mononucleosis including pharyngitis and lymphadenopathy but infection by Epstein Barr virus or cytomegalovirus has been ruled out by serological tests. Responsibility of salazosulfapyridine was highly suggested by the following facts: hepatocellular necrosis was sharply centrolobular, plasmocytosis was the main finding in the white blood cells count and all abnormalities rapidly improved after treatment withdrawal. The authors point out that salazosulfapyridine intolerance could mimic infectious mononucleosis and viral hepatitis. In such cases the drug must be rapidly withdrawn to avoid massive hepatic necrosis.  相似文献   
133.
134.
Objective To observe the time course of changes in synaptophysin (P38) expression in the cortex and hippocampus of rats with posttraumatic epilepsy (PTE), and explore the role of synaptic plasticity in the epileptogenesis of PTE. Methods Thirty-seven male Sprague-Dawley rats were randomized into normal control group (n=5), sham-operated group (n=12) with intracortical saline injection, and PTE model group (n=20) with stereotactic FeCl<,2> injection (0.1 mol/L, 10 μ1) into the motor cortex. The expression of P38 in the brain cortex and hippocampus of the rats was detected immunohistochemically at 1 h and 7, 14 and 30 days after the injections. Results Most of the rats with FeCl<,2> injection developed isolated epileptiform discharges soon alter the injection. Compared with the sham-operated groups, the rats in PTE group showed significantly decreased P38 expression in the right frontal cortex at all the time points of measurement (P<0.05). At 1 h after FeCl<,2> injection, P38 expression in the polymorphic layer, stratum lacunosum and stratum radiatum of the right hippocampai CA3 area and DG molecular layer underwent no significant changes (P>05), but at 7 days, the expression increased significantly in all the stratum regions of the right hippocampal CA3 area, and this high expression level was maintained till 30 days after the injection. Conclusion Synaptic plasticity alterations in relation to P38 expression changes in the cortex and hippocampus may play an important role in the epileptogenesis of PTE in this rat model.  相似文献   
135.
AIM: To compare bacillus Calmette-Guerin (BCG) with epirubicin in adjuvant therapy of superficial bladder transitional cell carcinoma, with respect to recurrence, progression and survival. Prognostic factors are also evaluated. METHODS: Between October 1991 and September 1999, all patients harboring superficial bladder cancers (Ta or T1) with any of the relevant criteria (stage>a, grade>1, size>1 cm, multiple or recurrent tumors), after complete transurethral resection were randomized to receive either 81 mg Connaught strain BCG or 50 mg epirubicin. Patients with recurrences were eligible to crossover, even repeatedly, until progression. Recurrence, progression and survival were analyzed in relation to initial treatment, patient characteristics and tumor characteristics. RESULTS: There were 209 patients included in the study, 149 men and 60 women. The mean age was 69.9 years (range, 24-92). The BCG group consisted of 102 patients and the epirubicin group contained 107 patients. Final analysis was made at a median follow up of 23, 47 and 61 months for recurrence, progression and survival, respectively. The 10-year Kaplan-Meier estimates for recurrence-free, progression-free and disease-specific survival were 61%, 78% and 80%, respectively, for the BCG group. The corresponding figures were 32%, 74% and 92%, respectively, for the epirubicin group. Time to recurrence differed significantly between two treatment groups (P=0.0004). Multiplicity increased the risk of recurrence, while grading influenced recurrence, progression and disease specific survival. CONCLUSIONS: Bacillus Calmette-Guerin prolonged time to recurrence when compared with epirubicin. Grading was shown to be a universal prognostic factor for recurrence, progression and disease specific survival.  相似文献   
136.
Blood pressure control in normotensive members of hypertensive families   总被引:1,自引:0,他引:1  
The cardiovascular pressor responses to a stepwise increase in plasma norepinephrine or angiotensin II concentrations, induced by infusions, were studied in 23 normotensive subjects with a negative and 25 with a positive family history of essential hypertension. The two study groups had a similar mean age (24 +/- 2 (SD) yr), body weight, blood pressure (112/64 +/- 10/7 mmHg), heart rate, plasma and urinary sodium and potassium, and plasma norepinephrine, epinephrine, angiotensin II, renin and aldosterone levels. However, subjects with positive history differed from those with negative history of hypertension by a decreased pressor dose of infused norepinephrine (89 +/- 29 vs. 135 +/- 66 ng/kg/min; P less than 0.005), and a significant (P less than 0.01) shift to the left of the relationship between norepinephrine-induced changes in mean arterial pressure and concomitant changes in plasma norepinephrine. In contrast, the relation between stepwise increasing plasma angiotensin II levels and induced changes in diastolic blood pressure or plasma aldosterone did not differ significantly between the two study groups. These findings delineate a distinct abnormality which may often occur in normotensive offspring of hypertensive families. It is characterized by a selectively disturbed noradrenergic blood pressure control in the presence of a normal angiotensin-mediated blood pressure and aldosterone regulation.  相似文献   
137.
138.
The development of thrombolytic and neuroprotective agents for the treatment of acute stroke has created an imperative for improved imaging techniques in the assessment of acute stroke. Five cases are presented to illustrate the value of perfusion CT in the evaluation of suspected acute stroke. To obtain the perfusion data, a rapid series of images was acquired without table movement following a bolus of contrast medium. Cerebral blood flow, cerebral blood volume and mean transit time were determined by mathematically modelling the temporal changes in contrast enhancement in the brain and vascular system. Pixel‐by‐pixel analysis allowed generation of perfusion maps. In two cases, CT‐perfusion imaging usefully excluded acute stroke, including one patient in whom a low‐density area on conventional CT was subsequently proven to be tumour. Cerebral ischaemia was confirmed in three cases, one with an old and a new infarction, one with a large conventional CT abnormality but only a small perfusion defect, and one demonstrating infarct and penumbra. Perfusion CT offers the ability to positively identify patients with non‐haemorrhagic stroke in the presence of a normal conventional CT, to select those cases where thrombolysis is appropriate, and to provide an indication for prognosis.  相似文献   
139.
A twin infant who survived the death of his monochorionic co-twin in utero and was born with multiple jejunoileal atresias and severe cerebral damage is reported. The pathogenesis of these defects is discussed in the light of previously reported similar cases. The incidence of severe brain damage in twins born alive after the intrauterine death of a monochorionic co-twin is high, suggesting brain destruction by embolization of thromboplastin-rich material from the dead fetus via placental vascular anastomoses. A similar mechanism could be evoked in the present case to account for the intestinal atresias, which likely occurred after the 22nd gestational week, i.e. after the normal permeabilization of the embryonic gut. In the light of this observation and similar ones made by others, it is clear that surgical management of congenital defects during the neonatal period should be influenced by the knowledge of in-utero death of a monochorionic co-twin during the second half of gestation.  相似文献   
140.
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