全文获取类型
收费全文 | 1031篇 |
免费 | 64篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 43篇 |
妇产科学 | 11篇 |
基础医学 | 90篇 |
口腔科学 | 65篇 |
临床医学 | 94篇 |
内科学 | 176篇 |
皮肤病学 | 21篇 |
神经病学 | 30篇 |
特种医学 | 194篇 |
外科学 | 126篇 |
综合类 | 75篇 |
预防医学 | 60篇 |
眼科学 | 4篇 |
药学 | 45篇 |
中国医学 | 24篇 |
肿瘤学 | 41篇 |
出版年
2023年 | 3篇 |
2022年 | 6篇 |
2021年 | 6篇 |
2020年 | 7篇 |
2019年 | 6篇 |
2018年 | 22篇 |
2017年 | 19篇 |
2016年 | 17篇 |
2015年 | 17篇 |
2014年 | 30篇 |
2013年 | 62篇 |
2012年 | 51篇 |
2011年 | 49篇 |
2010年 | 44篇 |
2009年 | 40篇 |
2008年 | 46篇 |
2007年 | 63篇 |
2006年 | 33篇 |
2005年 | 28篇 |
2004年 | 26篇 |
2003年 | 16篇 |
2002年 | 17篇 |
2001年 | 23篇 |
2000年 | 11篇 |
1999年 | 19篇 |
1998年 | 62篇 |
1997年 | 49篇 |
1996年 | 37篇 |
1995年 | 24篇 |
1994年 | 27篇 |
1993年 | 24篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 7篇 |
1989年 | 22篇 |
1988年 | 25篇 |
1987年 | 26篇 |
1986年 | 14篇 |
1985年 | 21篇 |
1984年 | 9篇 |
1983年 | 15篇 |
1982年 | 10篇 |
1981年 | 8篇 |
1980年 | 10篇 |
1978年 | 8篇 |
1977年 | 7篇 |
1976年 | 9篇 |
1975年 | 5篇 |
1967年 | 1篇 |
1954年 | 1篇 |
排序方式: 共有1105条查询结果,搜索用时 0 毫秒
1.
Maxillary sinusitis in adults: an evaluation of placebo-controlled double-blind trials 总被引:1,自引:0,他引:1
BACKGROUND: In general practice, acute sinusitis is frequently diagnosed
and treated with antibiotics. OBJECTIVE: This study aimed to determine the
evidence for the effectiveness of antibiotic treatment in acute maxillary
sinusitis in adults by assessing the methodological quality of
placebo-controlled double-blind randomized trials. METHOD: An evaluation by
four raters through a 35-item scoring-scale for internal and external
validity of all placebo-controlled double-blind randomized trials on acute
sinusitis found between January 1966 and July 1996. RESULTS: Eighty-five
trials were excluded because they were not placebo-controlled,
double-blind, randomized, or were carried out in patients with chronic
sinusitis or in children. The three remaining trials were performed in
different populations (one in general practice) between 1973 and 1978. Only
one study claimed superiority of antibiotic treatment. Different inclusion
criteria and major outcome measures were used by the authors. The
reliability of major outcome events was reported poorly or not at all and
in two studies outcome measures were clinically inappropriate. The studies
scored 30-62% of the maximum attainable score for internal validity and
10-20% for external validity. CONCLUSION: The effectiveness of antibiotic
treatment in acute maxillary sinusitis in a general practice population is
not based sufficiently on evidence.
相似文献
2.
H Angus-Leppan GA Lambert J Michalicek 《Cephalalgia : an international journal of headache》1997,17(6):625-630
Co-existence of facial and occipital pain may occur in occipital neuralgia, migraine and cluster headache; suggesting convergence of trigeminal and cervical afferents. Such convergence has been shown in humans and other animals, but the site and extent of this are uncertain. In anaesthetized adult cats, the superior sagittal sinus and occipital nerve were stimulated electrically, and extracellular recordings made in the dorsolateral area of the upper cervical cord using glass-coated tungsten electrodes. Of 49 units in 10 cats, 33 (67%) had input from the superior sagittal sinus and the occipital nerve. Thirteen (27%) had superior sagittal sinus input and 3 (6%) had occipital nerve input. Convergent receptive fields were identified mechanically in 7 units. These experiments in cats show convergent input from occipital nerve and superior sagittal sinus on dorsolateral area units in two-thirds of cases studied. This experimental site of trigeminocervical convergence may relate to referral of pain in occipital neuralgia and other headaches. 相似文献
3.
In patients with PG-dependent renal function, NSAID administration
constantly reduces GFR and RBF in a dose-dependent fashion. In this
situation, the risk of overt acute renal failure is high and should be
taken into proper account. In contrast, the incidence of NSAID-related
renal structural alterations appears to be very low, yet the absolute
number of patients may be significant considering the wide use of such
drugs. Concerning the antiproteinuric effect of NSAIDs, the unfavourable
ratio risk/benefit does not seem to support their indication in proteinuric
nephropathies. The development of PGHS-2 selective inhibitors is promising,
and may open new therapeutical strategies in the treatment of the
progression of renal disease.
相似文献
4.
Pathomechanics of structural foot deformities 总被引:2,自引:0,他引:2
D Tiberio 《Physical therapy》1988,68(12):1840-1849
This article presents the most common structural foot deformities encountered in clinical practice. The deformities are defined, and the expected compensations at the subtalar joint (STJ) are described. The theoretical consequences of the STJ compensations on proximal and distal tissues are presented. A biomechanical rationale for certain tissue disorders is described. The possible effects of abnormal STJ compensation on osseous development are briefly discussed. 相似文献
5.
D G Sawutz S S Singh L Tiberio E Koszewski C G Johnson C L Johnson 《Immunopharmacology》1992,24(1):1-10
In this study, we examined the effect of TNFa on bradykinin (BK) B2 receptor binding and function in human A431 epidermoid carcinoma cells. [3H]BK binds to a single class of receptors on A431 cells in a saturable and reversible manner. A binding affinity (KD) of 3.0 +/- 0.3 nM (n = 4) and a Bmax of 151 +/- 14 fmols/10(6) cells, representing approximately 90,000 BK receptors per cell, was observed. The rank order of potency for BK agonist peptides indicates that the A431 BK receptor appears to be of the B2 subtype. When A431 cells were incubated with TNFa (10 ng/ml) for 48 h prior to BK binding, a significant decrease in the number of BK receptors compared to control was observed. TNFa did not influence the affinity of BK binding to A431 cells and direct addition of TNFa to the binding assay did not effect BK binding. BK-stimulated IP1 formation appeared to be increased in TNFa treated cells compared to control whereas histamine-stimulated IP1 formation was not influenced. Both control and TNFa treated cells were greater than 95% viable. However, TNFa treated cells were blocked in the G1 phase of the cell cycle resulting in a decrease in DNA synthesis. This may be one mechanism for the TNFa-induced decrease in BK receptors in A431 cells. 相似文献
6.
M Floriani S M Giulini S Bonardelli N Portolani M Benvenuti A Pouchè G Tiberio 《Angiology》1988,39(11):967-972
Within a group of 2,000 patients evaluated, most of them with symptoms of cerebrovascular insufficiency, 441 had a monolateral or bilateral cervical bruit. The 627 sides with an audible bruit were divided into main groups (A) symptomatic (TIA and/or stroke homolateral to the bruit), (B) possibly symptomatic (non-side-related symptoms), (C) asymptomatic (C1, in totally asymptomatic patients; C2, in patients with symptoms dependent on the hemisphere contralateral to the cervical bruit). Each patient was studied by means of clinical (history, blood pressure in both upper limbs, phonoendoscopic auscultation at various levels) and noninvasive instrumental examinations (CW Doppler spectrum analysis). An apparently primitive cervical bruit corresponded to a lesion of the carotid bifurcation in 61% of the cases (positive predictive value) whereas a normal bifurcation was detected in 70% of the cases in which the cervical bruit was considered as secondary (negative predictive value); the diagnostic accuracy of the "critical auscultation" has a value therefore of 63%, with a sensitivity of 84% and a specificity of 40%. The results obtained in the different groups of patients (symptomatic or asymptomatic) were not significantly different (chi-square). Even though maintaining the value of a cervical bruit as a sign of carotid stenosis or occlusion and consequently confirming the importance of neck auscultation, the authors conclude that the critical auscultation as commonly performed is not capable of excluding the presence of a carotid lesion with sufficient reliability, even in totally asymptomatic patients. 相似文献
7.
8.
双—对二甲氨基苯甲醛缩二胺类希夫碱合成、表征及抗菌活性 总被引:9,自引:1,他引:8
目的:合成双-对二甲氨基苯甲醛缩二胺类希夫碱,并对其抗菌活性进行研究。方法:以对二甲氨基苯甲醛和二胺类为原料,经缩合反应,制得4种相应希夫碱。结果:结构经元素分析、红外光谱、核磁共振谱确定,4种化合物均未见文献报道,抗菌活性测试表明,它们具有一定抗菌活性。结论:乙酸是催化剂,对缩合反应有利,希夫碱化合物具有一定抗菌活性。 相似文献
9.
Portolani N Ronconi M Ghidoni S Gaverini G Coniglio A Tiberio GA Nodari F Giulini SM 《Chirurgia italiana》1999,51(5):335-343
The Authors discuss the principal early and long term predictive factors after liver resection in patients with hepatocellular carcinoma (HCC). The Authors report (131 cases) early mortality as 7.6%, entirely confined in the group, numerically prevalent and affected by cirrhosis. None of the 50 patients with chronic hepatitis (29 cases) or normal liver (21 cases) died after hepatic resection. Mortality is higher in Child B patients (20.7%) and in cases in which a massive haemotransfusion was given (p < 0.05), apart from the width of resection and from the number of hepatic resections. None of 41 cirrhotic Child A patients undergoing a limited hepatic resection (< or = 1 segment) died during the perioperative period. In the group of patients which survived to the resection, global survival at 5 years was 45%. The most important prognostic factor is local recurrence while cirrhosis and the degree of liver failure are not statistically significant. No feature can identify a subgroup of patients with a higher risk of recurrence, which is observed in 52% of patients with a follow up observation after more than 1 year. Among the 29 patients alive after more than 4 years from liver resection, only 11 didn't have local recurrence. The others were treated with iterative hepatic resections or with radiological techniques. In conclusion, the present experience suggests that, in selected cases, hepatic resection could be a low risk therapy (in cirrhotic patients as well). The long term results could improve with an aggressive attitude towards recurrence. 相似文献
10.
RAL Dampney Y. Hirooka PD Potts GA Head 《Clinical and experimental pharmacology & physiology》1996,23(Z3):105-111
- 1 It was first shown several years ago that the rostral part of the ventrolateral medulla (VLM) contains a high density of receptor binding sites for angiotensin II (AngII). In the present paper we briefly review recent studies aimed at determining the actions of both exogenous and endogenous angiotensin peptides in the rostral VLM, as well as their specific sites of action.
- 2 The results of these studies have shown that angiotensin peptides can excite pressor and sympathoexcitatory neurons in the rostral VLM, but do not appear to affect non-cardiovascular neurons in this region.
- 3 It is known that pressor neurons in the rostral VLM include both catecholamine and non-catecholamine neurons. There is evidence that, at least in conscious rabbits, both of these types of neurons are activated by AngII. The specific endogenous angiotensin peptide or peptides that affect pressor neurons in the rostral VLM have not yet been definitively identified.
- 4 It is also possible that different angiotensin peptides may have different effects on pressor neurons in the rostral VLM, mediated by different receptors. Further studies will be needed to define these different functions as well as the specific receptors and cellular mechanisms that subserve them.