全文获取类型
收费全文 | 9233篇 |
免费 | 597篇 |
国内免费 | 54篇 |
专业分类
耳鼻咽喉 | 95篇 |
儿科学 | 247篇 |
妇产科学 | 192篇 |
基础医学 | 1082篇 |
口腔科学 | 170篇 |
临床医学 | 836篇 |
内科学 | 2274篇 |
皮肤病学 | 209篇 |
神经病学 | 1071篇 |
特种医学 | 356篇 |
外科学 | 1560篇 |
综合类 | 16篇 |
一般理论 | 1篇 |
预防医学 | 442篇 |
眼科学 | 122篇 |
药学 | 648篇 |
中国医学 | 14篇 |
肿瘤学 | 549篇 |
出版年
2023年 | 64篇 |
2022年 | 179篇 |
2021年 | 280篇 |
2020年 | 158篇 |
2019年 | 222篇 |
2018年 | 271篇 |
2017年 | 207篇 |
2016年 | 224篇 |
2015年 | 234篇 |
2014年 | 331篇 |
2013年 | 433篇 |
2012年 | 601篇 |
2011年 | 606篇 |
2010年 | 364篇 |
2009年 | 324篇 |
2008年 | 503篇 |
2007年 | 533篇 |
2006年 | 510篇 |
2005年 | 543篇 |
2004年 | 504篇 |
2003年 | 419篇 |
2002年 | 381篇 |
2001年 | 173篇 |
2000年 | 203篇 |
1999年 | 159篇 |
1998年 | 111篇 |
1997年 | 70篇 |
1996年 | 62篇 |
1995年 | 53篇 |
1994年 | 66篇 |
1993年 | 41篇 |
1992年 | 103篇 |
1991年 | 113篇 |
1990年 | 100篇 |
1989年 | 90篇 |
1988年 | 88篇 |
1987年 | 85篇 |
1986年 | 66篇 |
1985年 | 58篇 |
1984年 | 39篇 |
1983年 | 42篇 |
1982年 | 24篇 |
1980年 | 18篇 |
1979年 | 24篇 |
1978年 | 14篇 |
1976年 | 13篇 |
1974年 | 20篇 |
1973年 | 19篇 |
1972年 | 15篇 |
1970年 | 18篇 |
排序方式: 共有9884条查询结果,搜索用时 15 毫秒
101.
Karamanoukian HL Dancona G Ricci M Bergsland J Salerno TA 《Journal of cardiac surgery》1999,14(5):390-391
Bleeding after aortic root replacement with a valved conduit may be problematic and difficult to control. A few technical details that may facilitate hemostasis in aortic root surgery are described. 相似文献
102.
Ricci M Karamanoukian HL D'Ancona G Bergsland J Salerno TA 《Journal of cardiac surgery》1999,14(6):460-461
The "single suture" technique, which consists of placing a suture in the oblique sinus of the posterior pericardium and connecting it to a vaginal tape, is commonly adopted in off-pump coronary artery revascularization to obtain elevation of the heart and coronary artery exposure. This report describes the use of this technique to expose the anterior wall of the heart in the setting of ventricular aneurysm repair. 相似文献
103.
Bisiach E Ricci R Silani G Cossa FM Crespi MG 《Cortex; a journal devoted to the study of the nervous system and behavior》1999,35(5):701-711
Thirteen right brain-damaged patients who were found to neglect pictures presented on the left of a display were presented the same stimuli, intermixed with foils, in a yes-no recognition test. Fifty per cent of patients claimed to have already seen one or more of the previously neglected pictures. This demonstrates that visual information that fails to access consciousness in neglect patients does retain the ability to surface as explicit memory at a later stage. 相似文献
104.
Troisi E Silvestrini M Matteis M Monaldo BC Vernieri F Caltagirone C 《Journal of neurology》1999,246(12):1172-1176
This study assessed the use of transcranial Doppler ultrasound in detecting selective changes in cerebral blood flow velocity
during emotional processes. The role of the respective hemispheres in emotional processing is controversial. Cerebral control
of emotional processing has previously been investigated by analysis of patients with unilateral brain damage, experiments
with selective stimulation of only one hemisphere, and more recently by imaging techniques measuring local cerebral blood
flow. We investigated mean flow velocity continuously and simultaneously in both the right and left middle cerebral arteries
(MCAs) in 16 healthy right-handed young subjects at rest and during the performance of three tasks: task 1: 15 slides with
nonemotional content; task 2: 15 slides with negative emotional content; task 3: 15 slides with nonemotional content with
different content from that in task 1. The three tasks produced significantly different effects on the right and left hemispheres.
During the two nonemotional tasks the increase in mean flow velocity over basal values was similar in the two MCAs (task 1:
left MCA = 3.27 ± 1.9%; right MCA = 3.63 ± 2.1%; task 3: left MCA = 2.42 ± 0.7%; right MCA = 2.56 ± 1.3%); the negative emotional
task was accompanied by a significantly higher increase in the right (11.31 ± 1.6%) than in the left MCA (4.72 ± 3.7%; analysis
of variance two-way interaction: side of recording x task, F = 43.6, P < 0.001). These results show the possibility of obtaining specific functional information from bilateral transcranial Doppler
ultrasound and suggest the involvement of the right hemisphere in emotional processing.
Received: 4 March 1999 Received in revised form: 29 June 1999 Accepted: 5 August 1999 相似文献
105.
We describe our experience with 8 Italian patients having mucopolysaccharidosis type IV, diagnosed between 1 and 10 years of life, who presented odontoid hypoplasia causing cervical myelopathy. We discuss the possibility of cranio-cervical stabilization in order to reduce the neurological complications. 相似文献
106.
Fabrizio MD Ratner LE Montgomery RA Kavoussi LR 《The Urologic clinics of North America》1999,26(1):247-56, xi
Live donor renal transplantation has many advantages including greater graft and patient survival, shorter waiting periods, improved human leukocyte antigen matching, and less cold ischemia. Until recently, disincentives from the operation, such as prolonged hospitalization, postoperative pain, and significant convalescence, have deterred live donor renal transplantation. This article describes the technique of laparoscopic live donor nephrectomy and briefly reports the results. The procedure has resulted in improved postoperative recovery and shorter convalescence, with no effect on recipient renal function. 相似文献
107.
BACKGROUND: Although acute cholecystitis is one of the most common indications for abdominal surgery in patients with acquired immunodeficiency syndrome (AIDS), previous studies have reported disappointingly high morbidity and mortality among those patients who have undergone cholecystectomy. The aims of this study were to analyze the indications for and the outcome of cholecystectomy performed for acute cholecystitis in patients with AIDS. METHODS: We retrospectively reviewed the hospital charts of 53 patients with AIDS who underwent open or laparoscopic cholecystectomy from 1992 to 1997. Statistical analysis using the chi-square, Student's t, and Fisher exact tests was conducted to determine whether cause of cholecystitis, type of surgical approach, and CD4+ T-lymphocyte count influenced outcome. RESULTS: The clinical findings and imaging by ultrasonography were always reliable in establishing diagnosis and guiding treatment of acute cholecystitis. Open cholecystectomy was performed in 24 patients (45%). The procedure was begun laparoscopically in 29 patients (55%) and converted to open in 4 (14%). The pathologic findings showed acalculous cholecystitis in 19 patients (36%) and cholelithiasis in 32 (60%). Morbidity was 34% and mortality was 2%. Type of operative approach, cause of cholecystitis, and CD4+ T-lymphocyte count (greater or less than 50 cells/mm3) did not significantly affect morbidity and mortality. The length of hospital stay was significantly influenced by the CD4+ T-lymphocyte count. CONCLUSIONS: These findings suggest that in most patients with AIDS, laparoscopic or open cholecystectomy may be performed with significant but acceptable morbidity and low mortality. 相似文献
108.
C. Ciacci MD R. Zarrilli MD PhD V. Ricci MD PhD A. De Luca MD G. Mazzacca MD C. Del Vecchio Blanco MD Dr. M. Romano MD 《Digestive diseases and sciences》1996,41(5):972-978
Gastric mucosal cell migration and proliferation are crucial events in the repair of gastric mucosal erosions. This study was designed to test the hypothesis that the H2 blockers roxatidine and ranitidine might stimulate migration and proliferation of gastric mucous cells derived from a human well-differentiated gastric adenocarcinoma cell line (MKN 28 cells)in vitro, in conditions independent of systemic factors and of acid inhibition. Confluent monolayers of MKN 28 cells were wounded with a razor blade and were then incubated with roxatidine or ranitidine. The number of cells migrating to the damaged area was determined 24 hr later. Cell proliferation was assessed by means of [3H]thymidine uptake and cell counts after incubation with roxatidine or ranitidine. Neither H2 antagonist significantly stimulated cell migration. On the other hand, cell proliferation was dose-dependently and significantly enhanced by incubation with roxatidine and ranitidine. Exogenous administration of TGF- significantly stimulated MKN 28 cell division. However, incubation with roxatidine or ranitidine did not increase the steady-state mRNA expression of TGF- or EGFR as assessed by northern blot analysis. Based on thesein vitro findings, we postulate that the ulcer healing effect of these H2 antagonistsin vivo might be due in part to stimulation of gastric mucosal cell proliferation.Data from this paper have been presented in part at the 1995 meeting of the American Gastroenterological Association and published in abstract form in Gastroenterology 108:A72, 1995. 相似文献
109.
E. Bertini C. Bosman G. Salviati R. Boldrini S. Servidei E. Ricci F. Del Nonno M. G. Gagliardi M. Bevilacqua 《Virchows Archiv : an international journal of pathology》1993,422(4):327-331
We present a undescribed condition in a girl who died at 8 years of hypertrophic cardiomyopathy. Muscle and endomyocardial biopsies disclosed a selective loss of thick filaments ultrastructurally. In muscle biopsy histochemical abnormalities of myofibrillar AT-Pase were confined to type 1 fibres. Gel electrophoresis of muscle homogenate showed no qualitative abnormalities of slow and fast myosin heavy chains (MHC) and light chains, and the amount of the different myosin isozymes was in agreement with histochemical myofibrillar ATPase findings. The pathogenetic mechanisms have not been elucidated in this case but we suspect an abnormality of the-cardiac MHC gene, the only gene expressed in the heart and in type 1 skeletal muscle fibres. 相似文献
110.
Fabrizio Tagliavini Giorgio Giaccone Orso Bugiani Blas Frangione 《Acta neuropathologica》1993,85(3):267-271
Summary Here ditary cerebral hemorrhage with amyloidosis Dutch type (HCHWA-D) is characterized clinically by recurrent strokes and pathologically by deposition of amyloid (A) in cerebral vessel walls and, to a lesser extent, in the neuropil. Distinct from Alzheimer's disease, amyloid formation in HCHWA-D is not associated with neurofibrillary changes. Since a central issue in the pathophysiology of Alzheimer's disease and related conditions is the role of A in the neurodegencrative process, we investigated HCHWA-D brains for the presence of neuritic abnormalities using antibodies to ubiquitin and to phosphorylated neurofilaments. The study showed that amyloid deposits in the vessel walls and in the neuropil were surrounded by abnormal ubiquitinated neurites, suggesting that A deposition induces neuritic changes.Supported by the Italian Ministry of Health. Department of Social Services, and by N.I.H. Grants AG05891 and AG08721 (to B.F.) 相似文献