全文获取类型
收费全文 | 1323408篇 |
免费 | 86025篇 |
国内免费 | 1753篇 |
专业分类
耳鼻咽喉 | 18716篇 |
儿科学 | 43363篇 |
妇产科学 | 37512篇 |
基础医学 | 190980篇 |
口腔科学 | 36168篇 |
临床医学 | 115516篇 |
内科学 | 249589篇 |
皮肤病学 | 29781篇 |
神经病学 | 99065篇 |
特种医学 | 52413篇 |
外国民族医学 | 241篇 |
外科学 | 201999篇 |
综合类 | 28329篇 |
现状与发展 | 2篇 |
一般理论 | 413篇 |
预防医学 | 92045篇 |
眼科学 | 30534篇 |
药学 | 103507篇 |
7篇 | |
中国医学 | 3439篇 |
肿瘤学 | 77567篇 |
出版年
2019年 | 9648篇 |
2018年 | 14303篇 |
2017年 | 11108篇 |
2016年 | 12670篇 |
2015年 | 14149篇 |
2014年 | 19168篇 |
2013年 | 28439篇 |
2012年 | 38161篇 |
2011年 | 40310篇 |
2010年 | 24282篇 |
2009年 | 22582篇 |
2008年 | 37375篇 |
2007年 | 40182篇 |
2006年 | 40545篇 |
2005年 | 38623篇 |
2004年 | 37091篇 |
2003年 | 35436篇 |
2002年 | 34122篇 |
2001年 | 70359篇 |
2000年 | 72040篇 |
1999年 | 59842篇 |
1998年 | 14933篇 |
1997年 | 13305篇 |
1996年 | 13163篇 |
1995年 | 12400篇 |
1994年 | 11243篇 |
1993年 | 10703篇 |
1992年 | 44483篇 |
1991年 | 43075篇 |
1990年 | 42384篇 |
1989年 | 40820篇 |
1988年 | 36770篇 |
1987年 | 35726篇 |
1986年 | 33706篇 |
1985年 | 31776篇 |
1984年 | 23099篇 |
1983年 | 19602篇 |
1982年 | 10876篇 |
1979年 | 20789篇 |
1978年 | 14195篇 |
1977年 | 12568篇 |
1976年 | 11019篇 |
1975年 | 12523篇 |
1974年 | 14545篇 |
1973年 | 14210篇 |
1972年 | 13483篇 |
1971年 | 12676篇 |
1970年 | 11745篇 |
1969年 | 11257篇 |
1968年 | 10163篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
H Gunen S S Hacievliyagil O Yetkin G Gulbas L C Mutlu E In 《The European respiratory journal》2007,29(4):660-667
The present study was designed to evaluate the hypothesis that nebulised budesonide (NB) might be an alternative to systemic corticosteroids (SC) in the treatment of patients with exacerbations of chronic obstructive pulmonary disease (ECOPD). Patients hospitalised with ECOPD (n = 159) were randomised into three groups. Group 1 received only standard bronchodilator treatment (SBDT), group 2 received SC (40 mg prednisolone) plus SBDT, and group 3 received NB (1,500 microg q.i.d.) plus SBDT. Improvement during 10-day hospitalisation was compared with exacerbation and rehospitalisation rates after discharge. While mean+/-sd age was 64.1+/-8.9 yrs (female/male = 0.1), mean forced expiratory volume in one second (FEV(1)) at admission was found to be 37.2+/-12.2% predicted. Arterial blood gases and spirograms recovered faster in groups 2 and 3. While improvements in arterial oxygen tension (P(a,O(2))) and forced vital capacity (FVC) in group 2, and improvements in P(a,O(2)), FVC and FEV(1) in group 3, became significant at 24-h control, the first significant improvement in group 1 appeared in arterial oxygen saturation at 72-h control. The mean improvement of P(a,O(2)) after 10 days was 1.20 and 1.06 kPa (9 and 8 mmHg) higher in group 2 and 3, respectively, than in group 1. Blood glucose exhibited an upward trend only in group 2. The study demonstrates that nebulised budesonide may be an effective and safe alternative to systemic corticosteroids in the treatment of exacerbations of chronic obstructive pulmonary disease. 相似文献
992.
Transabdominal sacrocolpopexy has been shown, in multiple long-term studies of its success and durability, to be the definitive
treatment option for post-hysterectomy vaginal vault prolapse. It is, however, associated with greater morbidity than vaginal
repair. We describe a minimally invasive technique for vaginal vault prolapse repair and present our experience with a minimum
of one-year follow-up. The surgical technique involves five laparoscopic ports—three for the da Vinci robot and two for the
assistant. After appropriate dissection a polypropylene mesh is attached to the sacral promontory and to the vaginal apex
by use of Gore-Tex sutures. The mesh material is then covered by the peritoneum. Patient analysis focused on complications,
urinary continence, patient satisfaction, and morbidity, with a minimum of 12 months follow-up. Forty-two patients with post-hysterectomy
vaginal vault prolapse underwent robot-assisted laparoscopic sacrocolpopexy at our institute and 35 have a minimum of 12 months
follow-up, with a mean follow-up of 36 months (range 12–48) in the group. Mean age was 67 (47–83) years and mean operating
time was 3.1 (2.15–4.75) h for the entire cohort. All but one patient were discharged home on postoperative day one; one patient
left on postoperative day two. One developed recurrent grade three rectocele, one had recurrent vault prolapse, and two suffered
from vaginal extrusion of mesh. All patients were satisfied with their outcome. The robot-assisted laparoscopic sacrocolpopexy
is a minimally invasive technique for vaginal vault prolapse repair, combining the advantages of open sacrocolpopexy with
the reduced morbidity of laparoscopy. We observed reduced hospital stay, low occurrence of complications, and high patient
satisfaction, with a minimum of 1-year follow-up. Most importantly, the long-term results of the robotic repair are similar
to those of open repair, but with significantly less morbidity. 相似文献
993.
994.
G. N. Smith Jr E. A. Mickler K. K. Payne J. Lee M. Duncan J. Reynolds B. Foresman D. S. Wilkes 《American journal of transplantation》2007,7(7):1856-1861
Parenchymal disease in the allograft lung is associated with interstitial remodeling believed to be mediated by matrix metalloproteinases (MMPs). Recent studies suggest high levels of MMP-9 are associated with bronchiolitis obliterans syndrome (BOS) in lung transplant recipients. Since BOS occurs late in the posttransplant period and may be preceded by episodes of acute rejection or infection, which are associated with interstitial remodeling, we examined MMP profiles in allograft bronchoalveolar lavage (BAL) fluid in the early posttransplant period (preceding BOS). Gelatin zymography, protein array analysis and specific ELISA on BAL fluids from transplanted lungs indicated that MMP-8, MMP-9 and TIMP-1 were strongly expressed in allograft BAL fluid from stable patients, or those with infection or rejection compared to BAL fluid from normal volunteers. Elevated expression of MMP-8, MMP-9 and TIMP-1 occurred early, and was sustained for the 3.2 years covered in this study. Elevations of MMP-8, MMP-9 and TIMP-1 in the first 2 years posttransplant appear to be associated with lung transplantation itself, and not infection or rejection. These data suggest that ongoing and clinically silent MMP activity could perpetuate progressive disease in the allograft lung. 相似文献
995.
Nienhaus A. Kromark K. Raulf-Heimsoth M. van Kampen V. Merget R. 《Trauma und Berufskrankheit》2007,10(1):75-77
Trauma und Berufskrankheit - Die Vermeidung gepuderter Latexhandschuhe gilt als wichtige Maßnahme zur Prävention von latexbedingten Haut- und Atemwegsallergien bei Beschäftigten im... 相似文献
996.
Z D Daniil E Zintzaras T Kiropoulos A I Papaioannou A Koutsokera A Kastanis K I Gourgoulianis 《The European respiratory journal》2007,30(5):957-964
Pleural effusion is a common complication of various diseases. Conventional methods are not always capable of establishing the cause of pleural effusion, so alternative tests are needed. The aim of this study was to explore means of discriminating between different pleural effusion groups, malignant, parapneumonic and tuberculous, based on the combined function of seven biological markers. Adenosine deaminase (ADA), interferon-gamma, C-reactive protein (CRP), carcinoembryonic antigen, interleukin-6, tumour necrosis factor-alpha and vascular endothelial growth factor concentration levels were measured in pleural fluid from 45 patients with malignant, 15 with parapneumonic and 12 with tuberculous pleural effusion. Receiver operating characteristic curve analysis, multinomial logit modelling and canonical variate analysis were applied to discriminate the pleural effusion groups. The three groups could be discriminated successfully using the measured markers. The most important parameters for discrimination were ADA and CRP concentration levels. An individual with an ADA concentration level of >45 U.L(-1) and a CRP concentration of <4 mg.dL(-1) was more likely to belong to the tuberculous pleural effusion group, whereas one with an ADA concentration level of <40 U.L(-1) and a CRP concentration of >6 mg.dL(-1) was more likely to belong to the parapneumonic pleural effusion group, and one with a CRP concentration of <4 mg.dL(-1) to the malignant pleural effusion group. The combination of adenosine deaminase and C-reactive protein levels might be sufficient for discriminating between the three different groups of exudative pleural effusion: malignant, tuberculous and parapneumonic. 相似文献
997.
K Knapczyk M Duda D Czaplicki M Slomczynska 《Experimental and clinical endocrinology & diabetes》2007,115(7):411-416
Steroid hormones play an essential role in the ovarian cyclicity control and the progress of pregnancy. One of the crucial enzymes in the steroidogenesis is 3beta-hydroxysteroid dehydrogenase/Delta5-Delta4 isomerase (3betaHSD). The aim of the present study was to localize both 3betaHSD mRNA and protein in the ovary of pregnant swine. The immunolocalization of 3betaHSD was performed on paraplast sections of follicles and corpora lutea obtained on various days of gestation: 10, 18, 32, 50, 71 and 90 POST COITUM (p.c.). The obtained results were compared with those concerning follicular and luteal development in the ovaries of the cycling pig. Differences in 3betaHSD distribution between the ovarian follicles of cycling and pregnant pigs were concerned mainly in the pattern of immunostaining of the theca interna cells. In the porcine ovaries obtained on various days of pregnancy, some follicles exhibited positive immunostaining in most theca interna cells, while in other follicles this enzyme was expressed only in a relatively small percentage of theca interna cells. In the corpora lutea of the estrous cycle and pregnancy changes in the pattern of immunostaining were observed. At early and mid pregnancy (up to 71 day p.c.) 3betaHSD was observed in the large luteal cells while on day 71 p.c. the enzyme was present exclusively in the small luteal cells. The expression of 3betaHSD mRNA was detected by the use of RT-PCR technique in all investigated samples isolated at different stages of pregnancy. 相似文献
998.
K. K. Würzler M. Heisterkamp H. Böhm N. R. Kübler W. Sebald und J. F. Reuther 《Mund-, Kiefer- und Gesichtschirurgie》2004,8(2):75-82
ZusammenfassungFragestellung In der vorliegenden Studie am Göttinger Minischwein wurde die direkte Rekonstruktion des Unterkiefers nach ausgedehnter Kontinuitätsresektion mit autologem Knochen und einem osteoinduktiven Implantat untersucht.Methode An neun ausgewachsenen Göttinger Minischweinen wurde ein einseitiger, 5 cm langer Unterkieferkontinuitätsdefekt gesetzt. Die Rekonstruktion erfolgte bei vier Tieren mit einem 50×25×15 mm3 großen, kollagenen Träger, dotiert mit rhBMP-2 (400 µg/cm3). Bei zwei Tieren wurde nur der Träger alleine implantiert und bei drei Tieren das lokal resezierte Knochensegment replantiert. Die Knochenregeneration und Konsolidierung der Defekte wurde radiologisch und histologisch analysiert.Ergebnisse Nach Rekonstruktion mit dem osteoinduktiven Implantat zeigte sich bei allen Versuchstieren eine komplette knöcherne Konsolidierung des gesetzten Unterkieferkontinuitätsdefekts. Der gesamte Defekt wurde von einem biomechanisch hochwertigen, sich funktionell anpassenden Knochen überbrückt. Nach Replantation des ortsständigen autologen Knochens wird dieser nicht schnell genug knöchern integriert. In der Peripherie bilden sich nur unvollständige Knochenbrücken aus; dies führt zum vollständigen Versagen der Rekonstruktion. Ebenso findet bei der Implantation des Trägers alleine keine Konsolidierung statt.Schlussfolgerung Die direkte Rekonstruktion eines ausgedehnten, biomechanisch belasteten Defekts mit einem osteoinduktiven Implantat erwies sich als die überlegene Methode. Das hierbei entstehende knöcherne Regenerat erfährt eine unmittelbare funktionelle Strukturierung. Die Notwendigkeit zu extensiven adaptiven Umbauvorgängen wird hierdurch minimiert. 相似文献
999.
1000.
The rise in caesarean birth rate in Sagamu, Nigeria: reflection of changes in obstetric practice. 总被引:2,自引:0,他引:2
A retrospective and comparative study of women delivered by caesarean section over two different 3-year periods was conducted at Olabisi Onabanjo University Teaching Hospital, Sagamu, Nigeria. The caesarean section rate (CSR) increased from 10.3% in 1989-1991 to 23.1% in 2000-2003. The most frequent indication in both periods was different: prolonged/obstructed labour (20.0%) in 1989-1991 and antepartum haemorrhage (14.9%) in 2000-2003. Malpresentation, antepartum haemorrhage and pre-eclampsia/eclampsia were responsible for 51.7% of the difference in the CSR recorded between both periods. The CSR rose from 13.3% to 25.0% while the instrumental vaginal delivery (IVD) rate decreased significantly by 11.4% among the nulliparous women between the periods. Increase in CSR can be attributed mainly to reduction in IVD rate and alteration in the management of labour complications and induction policy. Strategies to reduce the CSR should cut across all indications and focus on encouraging instrumental vaginal deliveries, especially among nulliparous women. 相似文献