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   1702篇
  免费   101篇
  国内免费   2篇
耳鼻咽喉   20篇
儿科学   65篇
妇产科学   52篇
基础医学   223篇
口腔科学   123篇
临床医学   138篇
内科学   273篇
皮肤病学   23篇
神经病学   138篇
特种医学   94篇
外国民族医学   1篇
外科学   262篇
综合类   19篇
预防医学   86篇
眼科学   27篇
药学   89篇
中国医学   2篇
肿瘤学   170篇
  2023年   18篇
  2021年   25篇
  2020年   19篇
  2019年   24篇
  2018年   29篇
  2017年   18篇
  2016年   23篇
  2015年   29篇
  2014年   46篇
  2013年   58篇
  2012年   56篇
  2011年   60篇
  2010年   50篇
  2009年   56篇
  2008年   70篇
  2007年   47篇
  2006年   58篇
  2005年   61篇
  2004年   64篇
  2003年   63篇
  2002年   61篇
  2001年   43篇
  2000年   49篇
  1999年   54篇
  1998年   29篇
  1997年   35篇
  1996年   41篇
  1995年   36篇
  1994年   25篇
  1993年   20篇
  1992年   30篇
  1991年   31篇
  1990年   20篇
  1989年   38篇
  1988年   23篇
  1987年   28篇
  1986年   32篇
  1985年   22篇
  1983年   23篇
  1982年   16篇
  1980年   17篇
  1979年   12篇
  1978年   14篇
  1975年   15篇
  1973年   18篇
  1972年   14篇
  1970年   13篇
  1969年   13篇
  1967年   13篇
  1966年   13篇
排序方式: 共有1805条查询结果,搜索用时 15 毫秒
41.
A premature infant developed pericardial effusion four days after the insertion of a 25-gauge silastic percutaneous central venous catheter. The effusion contained parenteral nutrition fluid and resolved rapidly after withdrawal of the catheter. Pericardial effusion is a potential complication of percutaneous, as well as surgically placed, central venous catheters.  相似文献   
42.
Twenty-six adolescents, aged 13–18 years, with severe congenital heart disease were matched for sex, age and living area with 26 adolescents with repaired atrial septal defect and regarded as physically fit. These two groups were compared according to somatic condition, psychopathology, psychosocial functioning and chronic family difficulties. A higher rate of psychiatric problems in the complex group, an association between psychosocial functioning and physical capacity, as well as an association between psychosocial functioning and chronic family difficulties were observed. These findings suggest that physical capacity is of crucial importance for mental health and functioning of adolescents with congenital heart disease. The association with chronic family difficulties also suggests that a comprehensive biopsychosocial approach is necessary in the treatment and rehabilitation of these patients.  相似文献   
43.
Objective : Chronic middle ear disease is common in Aboriginal children, and may be linked to nasal inflammation and Eustachian tube dysfunction. The pattern of nasal inflammation is unknown. The study reported here was performed to define the role of allergy and infection in causing nasal inflammation in Aboriginal children with chronic middle ear disease.
Methodology : Thirty-one Aboriginal children aged between 3 and 7 years underwent clinical assessment, audiometry and allergy skin tests. Nasal swabs for bacterial culture and cytology were performed during the winter and again in spring to identify any seasonal variation. A randomized trial of nasal beclomethasone for 8 weeks was conducted in children with abnormal tympanometry to identify the effect of therapy upon nasal cytology.
Results : Twenty-six of the 31 children had abnormal tympanograms. Average hearing levels were reduced in nine children. Pathogenic organisms were isolated from most children: Streptococcus pneumoniae (82%), Haemophilus influenzae (79%), Moraxella catarrhalis (39%) and Staphylococcus aureus (29%). Eight of the 31 children (26%) were atopic. Nasal cytology disclosed a marked neutrophil infiltrate (80% of cells) during the winter, which fell significantly in spring to 52% of cells. Only two subjects had nasal eosinophilia of >10%. There was no effect of beclomethasone on nasal cytology.
Conclusions : Chronic ear disease in Aboriginal children is associated with nasal inflammation, neutrophil infiltration and the presence of bacteria. These features suggest respiratory infection as the main cause of chronic nasal inflammation in Aboriginal children with middle ear disease. There is a seasonal variation in the severity of the nasal infiltrate, consistent with increased infections during winter. Despite a high prevalence of atopy, allergic nasal disease was uncommon.  相似文献   
44.
Using the database from the Kabi Pharmacia International Growth Study, 105 patients with intrauterine growth retardation (IUGR) (82 males, 23 females) and 45 with Silver-Russell syndrome (SRS) (32 males, 13 females) with persistent postnatal growth failure were studied. Patients with IUGR had a birth length and birth weight more than 2 SD below the mean for gestational age. Their height deficit at the start of GH treatment was -3.0 SDS at a median chronological age of 8.7 years and a median bone age of 7.0 years. Mean paternal and maternal heights were 166 and 153 cm, respectively. The median dose of GH was 0.5 IU/kg/week, given at a median frequency of five injections/week. The median height SDS for chronological age after 1, 2 and 3 years of GH treatment were -2.5, -2.1 and -1.9, respectively. In the 45 patients with SRS, median chronological age and median bone age at the start of treatment were 6.7 and 3.2 years, respectively, and mean paternal and maternal heights were 167.5 and 160 cm, respectively. The median dose of GH was 0.7 IU/kg/week, given at a median frequency of six injections/week. The median height SDS for chronological age at the start of treatment and after 1, 2 and 3 years were -3.5, -2.9, -2.8 and -2.2, respectively. Although the criteria used by physicians when diagnosing SRS were not controlled or verified in this study, it appears that patients with SRS can be differentiated from those with IUGR with persistent growth failure by their reduced bone age for chronological age at the start of treatment, and by the fact that patients with SRS tended to be born to parents of normal height. GH treatment in both groups induced catch-up growth, though long-term follow-up studies will be required to assess the effects of treatment on final height.  相似文献   
45.
46.
47.
BACKGROUND: Heel-height difference has been used to detect subtle knee flexion contractures, but the effects of thigh circumference differences and patient positioning during testing have not been evaluated. HYPOTHESIS: Differences in thigh circumference measurements and whether the patient's patellae are on or off the examination table during heel-height difference measurement will not affect the accuracy of detecting knee flexion contracture. STUDY DESIGN: Prospective cohort study. METHODS: Bilateral knee range of motion, prone heel-height difference with the patellae on and off the table, and thigh circumference at 5 and 15 cm proximal to the proximal pole of the patella were measured by one investigator on 50 consecutive patients who had undergone unilateral anterior cruciate ligament reconstruction. RESULTS: A high degree of correlation was demonstrated between the heel-height difference and the standard range of motion measurement. Differences in thigh girth and patellar position did not statistically affect the accuracy of the heel-height difference as an indicator of knee flexion contracture. CONCLUSION: Heel-height difference is a valid method of documenting knee flexion contractures. Compared with traditional goniometer assessment, this test is a more meaningful and easier way for detecting subtle knee flexion contractures of less than 10 degrees.  相似文献   
48.
A 40-year-old woman with recently diagnosed bacterial endocarditis was admitted to the hospital with gross hematuria and anemia. Computed tomography revealed a large right upper pole renal artery pseudoaneurysm, a wedge-shaped hypoperfused region of the left kidney, and a splenic abscess. Radiographic embolization of the right renal artery was performed to stabilize the bleeding. The splenic abscess was drained. Subsequent right nephrectomy and splenectomy were performed for persistent leukocytosis. This unusual presentation of a septic embolus and its management are discussed.  相似文献   
49.
In a prospective study, we evaluated the efficacy of extracorporeal lithotripsy (ECL) in the treatment of salivary stones. We define the indications for the treatment of submaxillary and parotid stones, depending on the diameter and the location of the stone. Twenty-seven patients were treated by ECL. All had a unique stone, in the salivary duct, with a diameter greater than 2 mm; the site was the parotid gland for ten cases, the submaxillary gland for seventeen cases. After six months, the results from a clinical and ultrasonography point of view, were the following: total efficacy or complete desintegration of the stone: 9 cases; partial efficacy or fragmentation of the calculi, with residual fragments with a diameter of less than 2 mm, which could be flushed out with possible spontaneous clearance: 10 cases; failure or the lack of the reduction in the size of the stone or partial fragmentation into concrements with a diameter of more than 2 mm: 8 cases. Based on our experience and the results reported in the medical literature, we propose an therapeutic approach to symptomatic salivary stones. ECL is the most preferable treatment for stones of the parotid duct or parotid gland. The treatment of stones of the submaxillary gland depends on the site and the size of the calculi; ECL should be proposed as first-line treatment when the stone diameter ranges from 2 to 10 mm and when it is situated in the pelvis of the duct or in the proximal duct; surgical resection of the submandibular gland is indicated when the stone is situated in the gland itself or when the diameter is more than 10 mm; when it is situated in the distal duct, a marsupialization should be performed.  相似文献   
50.
OBJECT: To date, both arteriovenous malformations (AVMs) and cavernomas have been considered to be congenital malformations. A recent survey of the literature has shown the potential for de novo generation of both familial and sporadic cavernomas as well as AVMs. Therefore, it was of interest to determine the biological behavior of these lesions in detail. METHODS: The proliferative and angiogenic capacities of the endothelium of 13 cavernomas and 25 AVMs obtained in patients recently treated (1997-1998) at one institution were studied. Immunohistochemical staining for proliferating cell nuclear antigen (PCNA), MIB-1, and vascular endothelial growth factor (VEGF) and its receptor Flk-1 was performed using standard staining procedures. Positive immunostaining of the nuclei of endothelial cells was observed in specimens of both AVMs and cavernomas for PCNA (80% of AVMs and 85% of cavernomas), and Flk-1 (80% of AVMs and 31% of cavernomas). Endothelial expression of VEGF in the 18 incompletely embolized AVMs was found in 72% of cases but only in 28% of the seven cases in which patients did not undergo endovascular treatment: it was found in 38% of cavernomas. Endothelial expression of MIB-1 was found in 12% of AVMs but in no cavernomas. CONCLUSIONS: These results indicate that there is endothelial proliferation as well as neoangiogenesis in cerebral cavernomas and AVMs. The increased level of angiogenesis in only partially obliterated AVMs underscores the need for radical and complete occlusion of cerebral AVMs to avoid recurrences and further risks of morbidity.  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