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   1273274篇
  免费   88536篇
  国内免费   3246篇
耳鼻咽喉   16547篇
儿科学   42799篇
妇产科学   34667篇
基础医学   183924篇
口腔科学   34673篇
临床医学   112079篇
内科学   255312篇
皮肤病学   30564篇
神经病学   103516篇
特种医学   46407篇
外国民族医学   423篇
外科学   184430篇
综合类   25086篇
一般理论   464篇
预防医学   103350篇
眼科学   27813篇
药学   90772篇
  3篇
中国医学   2902篇
肿瘤学   69325篇
  2021年   12122篇
  2019年   12668篇
  2018年   18976篇
  2017年   13720篇
  2016年   14971篇
  2015年   16781篇
  2014年   21820篇
  2013年   33261篇
  2012年   47302篇
  2011年   49383篇
  2010年   28155篇
  2009年   25435篇
  2008年   44533篇
  2007年   47162篇
  2006年   46550篇
  2005年   45180篇
  2004年   43317篇
  2003年   41231篇
  2002年   39439篇
  2001年   53839篇
  2000年   55121篇
  1999年   46435篇
  1998年   12817篇
  1997年   11370篇
  1996年   11291篇
  1995年   10802篇
  1994年   9962篇
  1993年   9296篇
  1992年   35667篇
  1991年   34582篇
  1990年   33953篇
  1989年   32474篇
  1988年   29684篇
  1987年   29677篇
  1986年   27758篇
  1985年   26703篇
  1984年   19949篇
  1983年   16827篇
  1982年   10088篇
  1979年   18225篇
  1978年   13177篇
  1977年   11177篇
  1976年   10510篇
  1975年   11108篇
  1974年   13465篇
  1973年   12987篇
  1972年   11933篇
  1971年   11154篇
  1970年   10388篇
  1969年   9748篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Purpose:  To evaluate all consecutive patients treated with infliximab for hidradenitis suppurativa (HS).
Patients and methods:  Within 1 year, all consecutive patients seen in our department for HS (1) resistant to usual medical therapies (2) which could not be easily cured by surgery (3) not treated with new medication within 2 months before inclusion were treated intravenously with infliximab (5 mg/kg) without corticosteroids premedication. Four infusions were planned (week 0, week 2, week 6 and week 10) before the interruption of therapy and follow-up. Clinical activity of HS and quality of life of the patients were assessed immediately before the first, the third and the fourth infusions of infliximab.
Results:  Seven patients were included. Five completed the four infusions. Two patients received only three infusions because of severe side effects. The Sartorius score moderately improved with infliximab (mean score at week 0: 94 ± 39, at week 6: 71 ± 38 and at week 10: 83 ± 48). At week 6, patients judged the efficacy of therapy as marked ( n  = 1), moderate ( n  = 4) or null ( n  = 2). At week 10, five patients were evaluated and judged this efficacy as marked ( n  = 2), moderate ( n  = 2) or null ( n  = 1). The mean Skindex-29 score varied from 22 ± 11 (E: 25 ± 9, S: 13 ± 5, F: 28 ± 12) at week 0 to 18 ± 10 (E: 22 ± 8, S: 12 ± 8, F: 22 ± 12) at week 10.
Conclusion:  The efficacy of infliximab in severe HS is partial. More experience is needed before finding a place for infliximab in the therapeutic armamentarium for HS.  相似文献   
32.
AIM: The innovations for disease management need to be thoroughly evaluated so that their benefits and potential downsides can be compared with the already existing approaches. Endovascular laser (EVL) treatment for varicose veins offers today several advantages over surgical standard stripping. The Italian Endovenous-laser Working Group (IEWG) is a homogeneous group of surgeons and phlebologists who have been using EVL since 1999 and has undertaken to examine EVL in a multicenter study starting from a well defined rationale, with the benefit of a single protocol to use. METHODS: In a cooperative, multicenter, clinical study, 1076 limbs in 1050 patients, mean age of 54.5 years, 241 males and 809 females affected by chronic venous insufficiency (CVI) were considered eligible for surgery and stratified by CEAP classification in a four-year period (January 1999 December 2003). Inclusion criteria were insufficiency of the great and/or small saphenous vein at various levels, beyond those accessory saphenous trunks with incompetence in the saphenofemoral junction. In all cases truncular reflux apparead up on duplex scan examination, with or without associated varicosities. All the patients underwent a surgery on the basis of the clinical assessment. All the centres involved performed treatment in conformity with the Food and Drug Administration (FDA) validated procedure, using an endo-laser venous system kit with a 810-980 nm diode. Duplex scan was performed in all patients after 36 months with very few lost to follow-up cases. RESULTS: In the immediate postoperative period the results have been impressive, with a very effective closure of incompetent great saphenous vein and the other treated varicose veins (the early occlusion rate has been 99%). Major complications have not been detected: in particular, no deep venous thrombosis (DVT) evaluated duplex ultrasound. The patients' acceptability and satisfaction regarding the procedure, have been measured by means of a questionnaire on the quality of life, and the result was 96.7%. After 36 months, the total occusion rate of saphenous trunks has been 97%. CONCLUSIONS: The first important Italian experience with EVL based on preoperative, perioperative and postoperative duplex control and which is also based on the patients' satisfaction at mid/long-term has indicated some advantages over the standard treatment with the stripping method. In terms of reduced postoperative pain, shorter sick leave, a faster resumption of the normal activities, and, in particular, the total absence of DVT, we can conclude that EVL is a good solution for all patients with anatomic and hemodinamic patterns for saphenous vein surgery.  相似文献   
33.
34.
35.
We aimed to evaluate the potential of the cerebrospinal fluid (CSF) axonal damage biomarker NfH(SMI35) in the laboratory-supported differential diagnosis of parkinsonian syndromes. Patients with idiopathic Parkinson's disease (PD; n = 22), multiple-system atrophy (MSA; n = 21), progressive supranuclear palsy (PSP; n = 21), corticobasal degeneration (CBD; n = 6), and age-matched controls (n = 45) were included. CSF levels of NfH(SMI35) were measured using ELISA. Levels of CSF NfH(SMI35) were elevated in PSP compared to PD and controls (P < 0.05 each). They were also significantly higher in MSA than in PD and controls (P < 0.05 each). NfH(SMI35) differentiated PD from PSP with a sensitivity of 76.5% and a specificity of 94.4%. Axonal damage as measured by CSF NfH(SMI35) is most prominent in the more rapidly progressive syndromes PSP and MSA as compared to PD or CBD. CSF NfH(SMI35) may therefore be of some value for the laboratory-supported differential diagnosis of atypical parkinsonian syndromes.  相似文献   
36.
Medullary thyroid carcinoma (MTC) is a rare form of thyroid cancer representing about 10% of all thyroid malignancies. It occurs mostly as a sporadic tumor or in association with autosomal dominant inherited cancer syndromes--multiple endocrine neoplasia (MEN) types 2A and 2B and familial MTC. Germline mutations in exons 8, 10, 11, 13, 14, 15 and 16 of the RET proto-oncogene are found in most of the familial cases. There are only a few published data reporting multiple germline mutations in the RET proto-oncogene. We have detected double germline mutations in 2 different exons on the same RET allele in two MEN 2 families. In the MEN 2A family, double germline mutation in exons 10 (Cys620Phe) and 13 (Tyr791Phe) was detected. In the MEN 2B family, beside the classical germline mutation in exon 16 (Met918Thr) a second germline mutation in exon 13 (Tyr791Phe) was found. This study revealed that MEN 2 syndromes can also be caused by double germline mutations in the RET proto-oncogene and these families can be added to small worldwide cohort of families with multiple germline mutations.  相似文献   
37.
Sniff nasal inspiratory pressure (SNIP) measurement is a volitional noninvasive assessment of inspiratory muscle strength. A maximum of 10 sniffs is generally used. The purpose of the present study was to investigate whether the maximum SNIP improved after the tenth sniff. In total, 20 healthy volunteers and 305 patients with various neuromuscular and lung diseases were encouraged to perform 40 and 20 sniffs, respectively. The best SNIP among the first 10 sniffs was lower than the best SNIP among the next 10 sniffs in the healthy volunteers and patients. The SNIP improvement after the twentieth sniff was marginal. In conclusion, a learning effect persists after the tenth sniff. The current authors suggest using 10 additional sniffs when the best result of the first 10 sniffs is slightly below normal, or when sniff nasal inspiratory pressure is used to monitor a progressive decline in inspiratory muscle strength.  相似文献   
38.
39.
Abstract: Background: Fetal pulse oximetry improves the assessment of fetal well‐being during labor. The objective of this study was to evaluate women's satisfaction with their experience with this additional technology. Methods: We surveyed women participating in the FOREMOST trial, a randomized controlled trial comparing the addition of fetal pulse oximetry (FPO) to conventional cardiotocograph (CTG) monitoring (intervention group), versus CTG‐only (control group), in the presence of nonreassuring fetal status during labor. Our survey evaluated 3 aspects of women's experience: labor, fetal monitoring, and participation in the research. The survey was administered within a few days of giving birth and repeated 3 months later. Results: No differences were found between the intervention and control groups for women's evaluations of their labor, fetal monitoring, research, or overall experiences when surveyed on both occasions. Within each study group, a small but statistically significant decline occurred in women's scores for their experience of labor and overall experience from the initial survey close to the time of giving birth, to 3 months later. The magnitude of differences in responses over time was similar for the both groups. Women were more satisfied after a spontaneous or assisted vaginal birth than after cesarean section. Length of time the research midwife was present had a significant positive effect on women's ratings of their experience several days after giving birth (p = 0.006), but no effect at 3 months. Conclusions: The addition of fetal pulse oximetry for the assessment of fetal well‐being during labor did not affect childbearing women's perceptions of fetal monitoring or their labor. Women evaluated their experience in the research process positively overall. Small changes occurred in women's perception of their satisfaction over time. (BIRTH 33:2 June 2006)  相似文献   
40.
B.  Greg  Brown  John  Growley  宋善俊 《美国医学会杂志》2006,25(2):124-126
过去15年来,有关动脉粥样硬化的流行病学、基础生物学和实验研究均支持下述假设:抗氧化剂可通过抑制动脉壁低密度脂蛋白的氧化而抑制动脉粥样硬化的发生。这种作用机制可抑制胆固醇酯通过巨噬细胞清除受体在动脉斑块内发生病理性沉积。胆固醇酯病理沉积是一种可引起斑块破裂及心血管事件的过程。同样,生物机制亦已确定,癌基因可被抗氧化剂阻断。  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