全文获取类型
收费全文 | 2124121篇 |
免费 | 157643篇 |
国内免费 | 6411篇 |
专业分类
耳鼻咽喉 | 27522篇 |
儿科学 | 71412篇 |
妇产科学 | 59281篇 |
基础医学 | 310919篇 |
口腔科学 | 58763篇 |
临床医学 | 201375篇 |
内科学 | 406542篇 |
皮肤病学 | 45153篇 |
神经病学 | 174097篇 |
特种医学 | 78725篇 |
外国民族医学 | 651篇 |
外科学 | 303125篇 |
综合类 | 48790篇 |
现状与发展 | 1篇 |
一般理论 | 813篇 |
预防医学 | 176834篇 |
眼科学 | 48004篇 |
药学 | 155736篇 |
8篇 | |
中国医学 | 4801篇 |
肿瘤学 | 115623篇 |
出版年
2019年 | 17193篇 |
2018年 | 24263篇 |
2017年 | 18465篇 |
2016年 | 20451篇 |
2015年 | 23261篇 |
2014年 | 32002篇 |
2013年 | 49553篇 |
2012年 | 66858篇 |
2011年 | 71029篇 |
2010年 | 41857篇 |
2009年 | 38819篇 |
2008年 | 65490篇 |
2007年 | 69250篇 |
2006年 | 69797篇 |
2005年 | 67220篇 |
2004年 | 64661篇 |
2003年 | 61762篇 |
2002年 | 59881篇 |
2001年 | 95658篇 |
2000年 | 98137篇 |
1999年 | 82398篇 |
1998年 | 23577篇 |
1997年 | 21322篇 |
1996年 | 21138篇 |
1995年 | 20241篇 |
1994年 | 18763篇 |
1993年 | 17583篇 |
1992年 | 65852篇 |
1991年 | 64779篇 |
1990年 | 62986篇 |
1989年 | 60147篇 |
1988年 | 55436篇 |
1987年 | 54856篇 |
1986年 | 51805篇 |
1985年 | 49729篇 |
1984年 | 37593篇 |
1983年 | 31805篇 |
1982年 | 19209篇 |
1981年 | 17036篇 |
1979年 | 34427篇 |
1978年 | 24759篇 |
1977年 | 20535篇 |
1976年 | 19855篇 |
1975年 | 20516篇 |
1974年 | 24988篇 |
1973年 | 24318篇 |
1972年 | 22429篇 |
1971年 | 20914篇 |
1970年 | 19367篇 |
1969年 | 17823篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
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
62.
63.
R C Pattinson L C Snyman A P Macdonald 《Suid-Afrikaanse tydskrif vir geneeskunde》2006,96(11):1191-1194
AIM: To evaluate whether the introduction of a strict protocol approach based on the systemic evaluation of critically ill pregnant women with complications of abortion affected outcome. SETTING: Indigent South Africans managed in the regional and tertiary hospitals of the Pretoria Academic Complex. METHOD: Since 1997 a standard definition of severe acute maternal morbidity (SAMM) has been used in the Pretoria Academic Complex. All cases of SAMM and maternal deaths were entered on the Maternal Morbidity and Mortality Audit System programme. A comparison of outcome of severely ill women who had complications of abortion was made between 1997-1998 (original protocol) and 2002-2004 (strict protocol). OUTCOME MEASURES: The mortality index and prevalence of organ system failure or dysfunction. RESULTS: In 1997-1998 there were 43 women with SAMM who survived and a further 10 maternal deaths due to complications of abortion, compared with 107 women with SAMM and 7 maternal deaths during 2002-2004. The mortality index declined from 18.9% in 1997-1998 to 6.1% in 2002-2004 (p = 0.02, odds ratio 0.28, 95% confidence limits 0.10 - 0.79). Significantly more women had hypovolaemic shock in 2002-2004 compared with 1997-1998 (54.4% v. 35.8%, p = 0.04), but fewer women had immune system failure including septic shock (18.4% v. 47.2%, p = 0.0002) and metabolic dysfunction (0 v. 5.7%, p = 0.03) and there was a trend to less renal failure (10.5% v. 22.6%, p = 0.06) and cardiac failure (4.4% v. 13.2%, p = 0.08). CONCLUSION: The strict protocol approach based on systemic evaluation in managing critically ill pregnant women with complications of abortion, coupled with an intensive, regular feedback mechanism, has been associated with a reduction in the mortality index. 相似文献
64.
Philip A. Rozario Nancy L. Morrow-Howell Enola K. Proctor 《Quality of life research》2006,15(4):755-759
Using the SF-12 to measure physical and mental functioning, the authors examine the intra-individual changes in health-related
quality of life (HRQOL) 6 months post-discharge for depressed older adults. In addition, they examine three sets of predictors
that might influence these changes. The sample of depressed older adults was recruited from an inpatient geropsychiatry unit.
Although their physical and mental health scores on the SF-12 were lower than comparable norms, the sample showed an average
increase in their mental functioning but a decrease in the physical functioning over the 6 months. Negative life-events were
significant predictors of people who reported no change in their mental health functioning and decreases in their physical
health functioning. Interestingly, those who experienced positive life events were more likely to report declines and younger
participants were more likely to report no change in their physical functioning. The findings indicate that the effects of
depression on HRQOL can have enduring effects on a sample of previously hospitalized older adults. The significance of life
event changes might signify the importance of taking into account non-traditional areas of medical interventions. Further,
the findings indicate the usefulness of the SF-12 quantifying HRQOL outcomes. 相似文献
65.
66.
67.
68.
Zinc sulfate addition to glass-ionomer-based cements: influence on physical and antibacterial properties, zinc and fluoride release. 总被引:5,自引:0,他引:5
Prudencio W R Osinaga Rosa Helena M Grande Rafael Y Ballester Maria Regina L Simionato Célia Regina M Delgado Rodrigues Antonio Muench 《Dental materials》2003,19(3):212-217
OBJECTIVES: The aim of this study is to evaluate the effect of ZnSO(4) addition to a conventional glass ionomer and a resin-modified glass ionomer on solubility, flexural strength, zinc and fluoride (F) release, and Streptococcus mutans growth inhibition. METHODS: 5 or 10% ZnSO(4) was added to Vitremer and Ketac-Fil powders. Solubility test was performed based on ISO 7489. Flexural strength was determined by 3-point bending test based on ISO 4049. Zn release/uptake was determined by atomic emission spectrometry; F release/uptake was measured using a F-specific electrode. Both release measurements were performed for 15 d before and 15 d after recharging. Antibacterial test was conducted according to agar plate methods against S. mutans, by measuring the inhibition halos in 1-h and 15-d specimens. Data were analyzed by ANOVA. RESULTS: Solubility increased with higher ZnSO(4) content, but remained below the ISO 7489 limit. Flexural strength was not affected by ZnSO(4) addition, and Vitremer performed better than Ketac-Fil. The control materials released no zinc. Vitremer with 10% ZnSO(4) released the highest amount of zinc. Fluoride release was similar for Ketac-Fil and Vitremer. In both cases, the highest amounts were released in the first 24 h. The growth inhibition halo of S. mutans was similar for both materials with highest content of ZnSO(4) and occurred only with 1-h specimens. SIGNIFICANCE: Zinc addition decreased microorganisms growth and improved fluoride release, without significantly affecting the materials' flexural strength and solubility. 相似文献
69.
Daoyan Wei Henry Q. Xiong James L. Abbruzzese Keping Xie 《Journal of gastrointestinal cancer》2003,33(1):43-60
Pancreatic cancer is a lethal disease characterized by early metastasis, local invasion, and resistance to conventional therapies. To understand its etiology and eventually make prevention of it possible and effective, appropriate carcinogenesis models will certainly help us understand the effects of environmental and genetic elements on pancreatic carcinogenesis. The development of new treatment strategies to control cancer metastasis is of immediate urgency. Fulfillment of this task relies on our knowledge of the cellular and molecular biology of pancreatic cancer metastasis and the availability of biologically and clinically relevant model systems. Many of the existing pancreatic cancer carcinogenesis and metastasis animal models are described in this review. The advantages and disadvantages of each model and their clinical implications are discussed, and special attention is focused on experimental therapeutic strategies targeting pancreatic cancer metastasis. 相似文献
70.
Johannes Brettschneider Axel Petzold Sigurd D Süssmuth Georg B Landwehrmeyer Albert C Ludolph Jan Kassubek Hayrettin Tumani 《Movement disorders》2006,21(12):2224-2227
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