全文获取类型
收费全文 | 1533篇 |
免费 | 178篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 150篇 |
妇产科学 | 27篇 |
基础医学 | 201篇 |
口腔科学 | 90篇 |
临床医学 | 157篇 |
内科学 | 284篇 |
皮肤病学 | 50篇 |
神经病学 | 46篇 |
特种医学 | 173篇 |
外科学 | 234篇 |
综合类 | 38篇 |
预防医学 | 95篇 |
眼科学 | 40篇 |
药学 | 53篇 |
中国医学 | 2篇 |
肿瘤学 | 93篇 |
出版年
2023年 | 14篇 |
2022年 | 10篇 |
2021年 | 13篇 |
2020年 | 14篇 |
2019年 | 7篇 |
2018年 | 44篇 |
2017年 | 46篇 |
2016年 | 41篇 |
2015年 | 60篇 |
2014年 | 76篇 |
2013年 | 107篇 |
2012年 | 46篇 |
2011年 | 29篇 |
2010年 | 78篇 |
2009年 | 91篇 |
2008年 | 28篇 |
2007年 | 48篇 |
2006年 | 48篇 |
2005年 | 25篇 |
2004年 | 28篇 |
2003年 | 13篇 |
2002年 | 19篇 |
2001年 | 15篇 |
2000年 | 9篇 |
1999年 | 24篇 |
1998年 | 101篇 |
1997年 | 86篇 |
1996年 | 99篇 |
1995年 | 64篇 |
1994年 | 74篇 |
1993年 | 39篇 |
1992年 | 14篇 |
1991年 | 21篇 |
1990年 | 13篇 |
1989年 | 31篇 |
1988年 | 29篇 |
1987年 | 28篇 |
1986年 | 26篇 |
1985年 | 24篇 |
1984年 | 12篇 |
1983年 | 9篇 |
1982年 | 20篇 |
1981年 | 15篇 |
1980年 | 16篇 |
1977年 | 9篇 |
1976年 | 13篇 |
1975年 | 9篇 |
1956年 | 8篇 |
1955年 | 6篇 |
1954年 | 7篇 |
排序方式: 共有1739条查询结果,搜索用时 62 毫秒
351.
352.
Quality assessment of transfusion practice in elective surgery 总被引:3,自引:0,他引:3
AM Giovanetti ; A Parravicini ; L Baroni ; D Riccardi ; MN Pizzi ; D Almini ; G Sirchia 《Transfusion》1988,28(2):166-169
A program of quality assurance (QA) was adopted to improve blood transfusion practice in elective surgery at a large urban hospital. For this purpose, a cooperative multidisciplinary group was formed, key indicators were identified, and an organization was set up. Data collected by this organization in the 1-year period needed for implementation of the program indicated that blood misuse was common practice. In fact, overrequest, overtransfusion, excessive reconstitution of whole blood (i.e., concurrent transfusion of red cells and fresh-frozen plasma), and underuse of predeposit were found in all ten surgical departments of the hospital. In a pilot study, data were collected from one surgical department during and after the implementation phase of the QA program; comparison of these data showed a postimplementation reduction of about two thirds in overtransfusion, whereas overrequest, reconstitution of whole blood, and predeposit rates remained unchanged. These results prompted continuation of the program in order to reach a definitive evaluation of its effectiveness. 相似文献
353.
JU Adelman A Brod RL Von Seggern LK Mannix AM Rapoport 《Cephalalgia : an international journal of headache》1998,18(9):605-611
Newer acute care migraine medications demonstrate improved rapidity of action, consistent effectiveness, excellent safety profiles, and rarely cause rebound headaches. Their use could decrease the need for migraine-preventive medication. The present analysis derives a formula that can be used by practitioners to determine the cost-effectiveness of various migraine-preventive medications relative to selected acute-care medications. We propose a measure called the cost-equivalent number (CEN), the number of headaches per month at which the cost of the preventive medication equals the cost savings in acute-care treatment realized by using the preventive medication. The use of the CEN individualizes the decision of whether to use a migraine-preventive medication, weighing both the efficacy and cost of the preventive medication against the cost of the acute-care medication. A CEN lower than the migraine frequency suggests that use of a preventive medication will be cost-effective. 相似文献
354.
Focal cortical dysplasia: appearance on MR images 总被引:15,自引:0,他引:15
355.
Association of anticardiolipin antibodies with intraglomerular thrombi and renal dysfunction in lupus nephritis 总被引:12,自引:0,他引:12
Bhandari S; Harnden P; Brownjohn AM; Turney JH 《QJM : monthly journal of the Association of Physicians》1998,91(6):401-409
We studied positivity for anti-cardiolipin antibody, intraglomerular
capillary thrombi on renal biopsy, and the progression of renal disease in
51 patients (10 male and 41 female), mean age 37 years (range 17-65 years),
with a diagnosis of systemic lupus erythematosis and clinically evident
nephritis confirmed by renal biopsy. Serum creatinine, serum indicators of
disease activity and biopsies were analysed in subgroups according to
thrombi and anticardiolipin status. End-points were death or chronic
dialysis requirement and survival. Degree of sclerosis, crescent formation
and necrosed glomeruli were all greater in those specimens positive for
thrombi and in those specimens of patients who were serum ACA-positive,
suggesting a relationship to disease activity/severity at presentation. The
increase in serum anti-DNA antibodies and ANA and the reduction in C3 and
C4 were significant in ACA-positive patients, with a strong relationship to
disease activity when compared with changes in the ACA-negative patients (p
< 0.05 in all cases). There was no significant difference when patients
were separated according to the presence or absence of thrombi. Renal
function at presentation was worse in patients with intracapillary thrombi
and ACA positivity (p = 0.085 and p = 0.042, respectively). All patients
progressed, but only those with intracapillary thrombi or anti- cardiolipin
antibody positivity had a significant deterioration in renal function.
Twenty-one thrombotic episodes occurred in 14 patients, of whom 13 were
ACA-positive. Anticardiolipin antibody is a strong predictor of the
presence of intraglomerular thrombi in SLE patients with renal involvement.
The presence of thrombi and/or anticardiolipin antibodies indicate a worse
long-term renal outcome. Anti-cardiolipin antibody positivity is a strong
predictor of systemic vascular thrombotic complications.
相似文献
356.
Cerebral microgyria, thalamic cell size and auditory temporal processing in male and female rats 总被引:4,自引:2,他引:2
Herman AE; Galaburda AM; Fitch RH; Carter AR; Rosen GD 《Cerebral cortex (New York, N.Y. : 1991)》1997,7(5):453-464
Induction of microgyria by freezing injury to the developing somatosensory
cortex of neonatal rats causes a defect in fast auditory processing in
males, but not in females. It was speculated that early damage to the
cortex has sexually dimorphic cascading effects on other brain regions
mediating auditory processing, which can lead to the observed behavioral
deficits. In the current series of experiments, bilateral microgyri were
induced by placement of a freezing probe on the skulls of newborn male and
female rats, and these animals were tested in adulthood for auditory
temporal processing. Control animals received sham surgery. The brains from
these animals were embedded in celloidin, cut in the coronal plane and the
following morphometric measures assessed: microgyric volume, medial
geniculate nucleus (MGN) volume, cell number, and cell size, and, as a
control, dorsal lateral geniculate nucleus (dLGN) volume, cell number and
cell size. There were no sex differences in the cortical pathology of
lesioned animals. However, microgyric males had more small and fewer large
neurons in the MGN than their sham-operated counterparts, whereas there was
no difference between lesioned and sham-operated females. There was no
effect on dLGN cell size distribution in either sex. Microgyric males were
significantly impaired in fast auditory temporal processing when compared
to control males, whereas lesioned females exhibited no behavioral
deficits. These results suggest that early injury to the cerebral cortex
may have different effects on specific thalamic nuclei in males and
females, with corresponding differences in behavioral effects.
相似文献
357.
358.
359.
360.
Diabetic periodontitis: possible lipid-induced defect in tissue repair through alteration of macrophage phenotype and function 总被引:9,自引:0,他引:9
AM Iacopino 《Oral diseases》1995,1(4):214-229
BACKGROUND: Diabetes mellitus is a major health problem in the United States affecting approximately 13 million people. The five ‘classic’ complications which have historically been associated with the condition are microangiopathy, neuropathy, nephropathy, microvascu-lar disease, and delayed wound healing. Recently, per-iodontal disease (PD) has been declared the ‘sixth’ major complication of diabetes as diabetics demonstrate an increased incidence and severity of PD. The cellular and molecular basis for diabetic PD is unknown. HYPOTHESIS: Recent evidence suggests that PD and delayed dermal wound healing may be manifestations of the same general systemic deficit in diabetes involving impairment of the cellular and molecular signal of wounding via alterations in macrophage phenotype. Diabetes-induced hyperlipidemia may interfere with the normal cellular and molecular signal of wounding by alteration of macrophage function and subsequent dysregulation of cytokines at the wound site. RESULTS: Preliminary data in both animal models and humans suggests that hyperglycemia, in combination with elevations of serum low density lipoproteins and tri-glycerides, leads to formation of advanced glycation end products (AGES) which may alter macrophage phenotype. This may be responsible for dysregulation of macrophage cytokine production and increased inflammatory tissue destruction and alveolar bone loss. IMPLICATIONS: Future investigations will consider diabetic PD in the context of a generalized systemic wound healing deficit that manifests as PD in the face of constant pathologic wounding of the gingiva (bacterial plaque) or delayed dermal wound healing in instances of periodic traumatic wounding to other parts of the body. These types of studies will provide information concerning defective tissue repair in diabetics that will have clinical relevance for the understanding of PD and delayed dermal healing as well as applications of appropriate and specific therapies. 相似文献