全文获取类型
收费全文 | 2506篇 |
免费 | 166篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 89篇 |
妇产科学 | 54篇 |
基础医学 | 325篇 |
口腔科学 | 79篇 |
临床医学 | 253篇 |
内科学 | 577篇 |
皮肤病学 | 44篇 |
神经病学 | 191篇 |
特种医学 | 215篇 |
外科学 | 206篇 |
综合类 | 16篇 |
一般理论 | 1篇 |
预防医学 | 202篇 |
眼科学 | 26篇 |
药学 | 186篇 |
中国医学 | 8篇 |
肿瘤学 | 209篇 |
出版年
2023年 | 11篇 |
2022年 | 41篇 |
2021年 | 68篇 |
2020年 | 30篇 |
2019年 | 68篇 |
2018年 | 77篇 |
2017年 | 48篇 |
2016年 | 49篇 |
2015年 | 63篇 |
2014年 | 84篇 |
2013年 | 106篇 |
2012年 | 105篇 |
2011年 | 115篇 |
2010年 | 71篇 |
2009年 | 76篇 |
2008年 | 144篇 |
2007年 | 138篇 |
2006年 | 120篇 |
2005年 | 122篇 |
2004年 | 96篇 |
2003年 | 95篇 |
2002年 | 75篇 |
2001年 | 80篇 |
2000年 | 83篇 |
1999年 | 72篇 |
1998年 | 47篇 |
1997年 | 26篇 |
1996年 | 33篇 |
1995年 | 22篇 |
1994年 | 22篇 |
1993年 | 20篇 |
1992年 | 25篇 |
1991年 | 47篇 |
1990年 | 26篇 |
1989年 | 40篇 |
1988年 | 38篇 |
1987年 | 34篇 |
1986年 | 40篇 |
1985年 | 31篇 |
1984年 | 22篇 |
1983年 | 19篇 |
1982年 | 11篇 |
1981年 | 10篇 |
1980年 | 15篇 |
1979年 | 11篇 |
1976年 | 13篇 |
1972年 | 10篇 |
1970年 | 10篇 |
1968年 | 10篇 |
1965年 | 10篇 |
排序方式: 共有2696条查询结果,搜索用时 31 毫秒
1.
Intratemporal vascular tumors: detection with CT and MR imaging 总被引:1,自引:0,他引:1
Lo WW; Shelton C; Waluch V; Solti-Bohman LG; Carberry JN; Brackmann DE; Wade CT 《Radiology》1989,171(2):445-448
The diagnostic contributions of computed tomography (CT) and magnetic resonance (MR) imaging were compared in 12 patients with benign intratemporal vascular tumors (hemangioma or vascular malformation). The tumors included six in the internal acoustic canal and six in the geniculate ganglion region. Clinical and histologic correlations were made. Two of the six patients with tumors in the internal acoustic canal underwent CT, and both required gas cisternography to show the tumor. Five patients in that group underwent MR imaging, and all five studies showed the tumor. All six patients with geniculate ganglion tumors underwent CT. Results in one study were questionable, and five showed the tumor. Five patients in this group underwent MR imaging, but the MR findings were positive in only two cases. MR imaging should therefore be performed before CT in the evaluation of facial nerve dysfunction, as it demonstrated all tumors in the internal acoustic canal and some in the geniculate ganglion region. If MR findings are negative, CT should then be performed to rule out a possible geniculate ganglion lesion. 相似文献
2.
von Hippel-Lindau disease affecting 43 members of a single kindred 总被引:22,自引:0,他引:22
We present a 6-generation kindred of over 221 members, 43 of whom were affected with von Hippel-Lindau (vHL) disease. Through a simple screening protocol, we diagnosed vHL retrospectively in 15 cases, and for the first time in 28, 11 of whom were presymptomatic. We found many complications of vHL in previously diagnosed relatives and in new cases. This study has demonstrated the utility and benefit of preventive surveillance in those known to have vHL, and of presymptomatic screening for affected relatives in families with vHL. The features of vHL were reviewed in our 43 cases and 511 cases from the medical literature. The patterns, frequencies, and ages of onset for each lesion were compared. Renal malignancies caused almost as much mortality in vHL as CNS malignancies. This family was exceptional for absence of pheochromocytoma and erythrocythemia, for more renal and pancreatic cysts and malignancies, and for slightly fewer eye or CNS lesions. Bilateral renal adenocarcinomata were found presymptomatically in five young subjects, who had bilateral nephrectomy and hemodialysis. Three survived long-term after renal transplants. Five relatives had pancreatic malignancies, which are definite although uncommon manifestations of vHL. Recommendations are made for family screening, which was economical and effective. Bayesian calculations help to predict risks for genetic counseling. The molecular basis of vHL may soon be found, since it has been linked to DNA markers on the short arm of chromosome 3. 相似文献
3.
James K. Hartsfield Bryan D. Hall Arthur W. Grix Boris G. Kousseff Jose F. Salazar Scott M. W. Haufe 《American journal of medical genetics. Part A》1993,45(5):552-557
We report on 7 patients (6 M, 1 F) with Coffin-Lowry syndrome who have a sensorineural hearing deficit in addition to developmental delay and characteristic facial changes. One of the patients also had a history of premature exfoliation of primary teeth. These are previously unappreciated clinical signs that may aid in the early diagnosis of Coffin-Lowry syndrome. Early diagnosis and recognition of a hearing deficit in the patient can lead to the use of hearing aids to help the patient achieve his or her full potential. These “;new”; clinical manifestations expand the phenotype of Coffin-Lowry syndrome and constitute an additional indication of pleiotropy. © 1993 Wiley-Liss, Inc. 相似文献
4.
K.A. Eaton F.M. Rimini E. Zak D.J. Brookman L.M.A. Hopkins P. J. Carmell LG. Yates C. A. Morrice B.A. Lall H. N. Newman 《Journal of clinical periodontology》1997,24(3):189-197
Abstract Several previous studies have evaluated the effects of 0.12% chlorhexidine digluconate (ChD) mouthrinses on plaque and gingival inflammation. However, previously, none have been based in general dental practices. The aim of this study was to evaluate the potential to conduct controlled periodontal clinical trials in co-operation with general dental practitioners (gdps). The project took place in 5 general dental practices in the South of England. 121 healthy subjects (24 at 4 sites and 25 at the 5th). aged 18-65 years, mean 35 ± 12) years participated in a double-blind, randomised study during which they received full mouth assessments for plaque and gingival bleeding at baseline, 6 and 12 weeks. 60 subjects were randomly asigned to use the 0.12% ChD mouth wash and 6i the placebo. The assessments were carried out by 5 gpds, who had previously achieved inter-examiner κ scores of 0.78–0.85 (mean 0.81) for the plaque index (PlI), and of 0.73–0.94 (mean 0.87) for a modified gingival index (mGI), and who maintained κ scores of 0.51–0.90 for PII and of 0.73–1.00 for mGI during the 12 months required to complete the study. 98 subjects (48 ChD and 50 placebo) completed the study. Even though the baseline levels of plaque and gingivitis were low, by week 12, mean whole mouth piaque score of the ChD mouthwash users had fallen from 1.33 at baseline to 0.96 and was significantly lower (p < 0.001) than for the placebo users, 1.31 at baseline to 1.13. Whole-mouth gingival bleeding score fell from 0.56 to 0.42 in the ChD mouthwash group but was unchanged (0.54–0.55) in the placebo group. A subsidiary data analysis which considered the effects at sites indicated that within these overall differences, the ChD users experienced almost 2× the reduction from plaque score 2 at baseline at proximal molar sites over a 12-week period (50.6% ChD versus 27.6% placebo). It was concluded that 0.12% ChD mouthwash reduced plaque accumulation fay 28% and gingival inflammation by 25% over a 12–week period, that it is feasible for a group of gdps to maintain high levels of inter–examiner consistency in the use of PlI and mGI, that it is also feasible to carry out such a multicentre study in general dental practice, and that the use of mean mouth scores per subject to analyse the effects of mouthrinses may well mask variations in response throughout the mouth. 相似文献
5.
Francis J Podbielski Heron E Rodriguez Andrew M Brown Matthew J Blecha Mario R Salazar Mark M Connolly 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2004,8(3):213-216
Management of an indeterminate pulmonary nodule is a diagnostic challenge that commonly confronts primary care physicians and specialists. Patients often present with this radiographic finding in the course of an unrelated medical evaluation. We examined our institution's experience with percutaneous biopsy of lung nodules to determine the impact of this procedure on overall patient care. Although significant complications are uncommon, the expedience of percutaneous lung biopsy often supplants a surgical opinion prior to initiation of therapy without added diagnostic benefit or cost-savings. Hence, we caution practitioners to use this technique as an adjunct to diagnosis and not a substitute for multidisciplinary care. 相似文献
6.
Changes in nitric oxide release in vivo in response to vasoactive substances. 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《British journal of pharmacology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
1. Changes in the release of nitric oxide (NO) in vivo were studied in rats following the administration of endothelium-dependent and -independent vasodilators as well as the NO synthesis inhibitor, NG-nitro-L-arginine methyl ester (L-NAME). NO production was assessed by measuring variations of nitrate in plasma by capillary ion analysis. 2. Intravenous administration of the endothelium-dependent vasodilators, bradykinin (2 and 10 micrograms kg-1 min-1) or substance P (0.3-3 micrograms kg-1 min-1) caused a transient dose-dependent hypotension followed by an increase in plasma nitrate concentration (maximal increments: 33 +/- 5% and 38 +/- 6%, for bradykinin and substance P, respectively). Prior administration of L-NAME (10 mg kg-1 min-1) inhibited the hypotension and increase in plasma nitrate caused by these substances. Intravenous administration of sodium nitrate (200 micrograms kg-1) also produced a transitory elevation in plasma nitrate which was similar in magnitude as that caused by the vasodilators. A rapid and transitory increment in plasma nitrate was observed after i.v. administration of authentic NO (400 micrograms kg-1). 3. Rats receiving the endothelium-dependent vasodilators, prostacyclin (0.6 micrograms kg-1 min-1) or adenosine (3 mg kg-1 min-1) intravenously showed a drop in blood pressure paralleled by a decrease in plasma nitrate (maximal decreases: 34 +/- 5% and 24 +/- 4%, for prostacyclin and adenosine, respectively). A similar effect on the plasmatic concentration of nitrate was observed when L-NAME (10 mg kg-1 min-1, i.v.) was administered to the animals. 4. This study demonstrates that (i) changes in plasma nitrate can be detected in vivo after stimulation or inhibition of NO synthase, (ii) an increased production of NO, measured as plasma nitrate, is related to the hypotension caused by bradykinin and substance P and (iii) a diminished concentration of plasmatic nitrate is associated to the hypotension induced by adenosine or prostacyclin (endothelium-independent vasodilators), suggesting that the L-arginine: NO pathway is capable of rapid down-regulation in response to a fall in blood pressure. 相似文献
7.
MD MPHCecilia Albala MD MScMabel Y ez MPh Mat.Sc.Gabriela Salazar MD MPHFernando Vio 《Nutrition Research》1994,14(12):1797-1809
Body composition measured with isotopic dilution was compared with anthropometric measurements. The study was carried out in 47 subjects from both sexes, 65 to 92 years old. Total body water (TBW), anthropometric measurements, and dynamometry were assessed. TBW was significatively higher in men than women and decreased with age. Dynamometry and fatfree mass were well correlated (r=0.73 in males and r=0.58 in females) and significantly different between sexes. A negative correlation was found for dynamometry with age, being significant for women. Linear regression equations to predict TBW from anthropometric measurements in males and females were obtained: Males: TBW(I)=19.349+0.617 weight(kg) — 0.931 mid-arm circumference(cm)+0.122 dynamometry (kg) Females: TBW(l)=−5.531+0.343 weight(kg)-0.213 triceps skinfold (mm)+ 0.148 dynamometry(kg) + 3.424 wrist diameter (cm). This simple model is proposed for use in epidemiological and field studies where other more sophisticated methods can not be applied. 相似文献
8.
9.
LG Dortmund 《MedR Medizinrecht》2007,25(8):493-494
Abstrakt Vergibt ein behandelnder Arzt eine Laboruntersuchung an einen externen Laborarzt, kommt entweder direkt ein Vertragsverh?ltnis
zwischen dem Laborarzt und dem Patienten zustande oder der Patient haftet dem Laborarzt aus den Grunds?tzen der Gesch?ftsführung
ohne Auftrag. 相似文献
10.