全文获取类型
收费全文 | 768篇 |
免费 | 72篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 56篇 |
妇产科学 | 10篇 |
基础医学 | 102篇 |
口腔科学 | 19篇 |
临床医学 | 66篇 |
内科学 | 179篇 |
皮肤病学 | 11篇 |
神经病学 | 53篇 |
特种医学 | 83篇 |
外科学 | 88篇 |
综合类 | 25篇 |
预防医学 | 59篇 |
眼科学 | 3篇 |
药学 | 39篇 |
中国医学 | 2篇 |
肿瘤学 | 38篇 |
出版年
2021年 | 10篇 |
2020年 | 10篇 |
2019年 | 20篇 |
2018年 | 21篇 |
2017年 | 8篇 |
2016年 | 8篇 |
2015年 | 11篇 |
2014年 | 10篇 |
2013年 | 32篇 |
2012年 | 30篇 |
2011年 | 29篇 |
2010年 | 36篇 |
2009年 | 25篇 |
2008年 | 25篇 |
2007年 | 31篇 |
2006年 | 27篇 |
2005年 | 29篇 |
2004年 | 17篇 |
2003年 | 26篇 |
2002年 | 15篇 |
2001年 | 17篇 |
2000年 | 12篇 |
1999年 | 22篇 |
1998年 | 22篇 |
1997年 | 16篇 |
1996年 | 16篇 |
1995年 | 17篇 |
1994年 | 8篇 |
1993年 | 12篇 |
1992年 | 14篇 |
1991年 | 6篇 |
1990年 | 19篇 |
1989年 | 15篇 |
1988年 | 15篇 |
1987年 | 20篇 |
1986年 | 14篇 |
1985年 | 13篇 |
1983年 | 10篇 |
1982年 | 6篇 |
1980年 | 9篇 |
1979年 | 18篇 |
1978年 | 14篇 |
1977年 | 10篇 |
1976年 | 10篇 |
1975年 | 8篇 |
1973年 | 7篇 |
1972年 | 7篇 |
1969年 | 5篇 |
1968年 | 11篇 |
1967年 | 12篇 |
排序方式: 共有840条查询结果,搜索用时 15 毫秒
1.
HOCK LEONG EE MBBS MRCP CHEE LEOK GOH MBBS FRCP KHOO ES-Y. CHAN PHD POR ANG MBBS MRCP 《Dermatologic surgery》2006,32(1):34-40
BACKGROUND: Acquired bilateral nevus of Ota-like macules (Hori's nevus) is a common dyschromatosis among Asian women. Q-switched lasers have been used successfully as a treatment modality. OBJECTIVE: The purpose of this study was to compare the efficacy of using the Q-switched 532 nm neodymium:yttrium-aluminum-garnet (Nd:YAG) laser followed by the 1,064 nm laser versus the Q-switched 1,064 nm Nd:YAG laser alone in the treatment of Hori's nevus. METHODS: This is a prospective left-right comparative study. Ten women with bilateral Hori's nevus were recruited and treated with a combination of the Q-switched 532 and 1,064 nm Nd:YAG lasers on the right cheek and the Q-switched 1,064 nm Nd:YAG laser alone on the left cheek. Only one laser treatment session was performed. The degree of pigmentation was objectively recorded with a mexameter. Subjective assessment was made by both patients and two blinded, nontreating dermatologists. RESULTS: At 6 months, there was a statistically significant difference (p = .009) of 35.10 points using objective mexameter measurements between the two sides, favoring the side treated with a combination of 532 and 1,064 nm laser treatment. Subjective grading by the patients and blinded dermatologists also confirmed that combination therapy was more successful after one treatment. Although combination treatment had a higher incidence of mild postinflammatory changes, this disappeared within 2 months. CONCLUSIONS: Concurrent use of the Q-switched 532 nm Nd:YAG laser in combination with the 1,064 nm laser is more effective in pigment clearance than the Q-switched 1,064 nm Nd:YAG laser alone for Hori's nevi. 相似文献
2.
Serial radionuclide studies using both Tc-99m DTPA (perfusion) and I-131 hippuran (tubular function) were correlated with histologic findings in 25 patients with renal transplants. These cases included 15 cases of cyclosporin-A nephrotoxicity (CsA-NT) and ten cases of acute cellular rejection that were retrospectively selected on the basis of biopsy findings and favorable clinical response to therapy specific for each of these conditions. The serial radionuclide studies enabled the correct diagnosis in 12 of 15 cases of CsA-NT and eight of ten cases of acute rejection. Posttherapy radionuclide studies, furthermore, demonstrated improvement consistent with clinical response. In all cases, the radionuclide results were available at least 24 hours before biopsy findings. These results indicate that serial radionuclide studies evaluating interval changes in both perfusion and tubular function are of significant value in the diagnosis and follow-up of CsA-NT and acute cellular rejection in transplant recipients. This initial experience suggests a sensitivity of 80%. 相似文献
3.
4.
R.P. Butt J.P. Huggins D. Greiling B. Hopkins S. Gaboardi D. Winslow M. Ronald S. Lewis S. Ward E. Levett J. Owen F. Burslem M. Collis S. Bailey P.V. Fish G. Whitlock S. Billotte K. James A. Mcelroy J. Blagg 《International journal of experimental pathology》2004,85(1):A20-A21
Introduction Fibrosis is a component of many tissue pathologies leading to loss of normal tissue function, primarily due to excessive collagen deposition. Collagen is deposited following cleavage of the C- and N- terminal peptides from the pro-collagen molecule. The cleavage of the globular C-peptide by PCP reduces solubility of the fibrillar collagen molecule, resulting in deposition of insoluble collagen. Increased insoluble collagen deposition is a feature of all organ fibroses, with inhibition of this process, a key potential anti-fibrotic mechanism. The aim of this work was to discover potent and selective PCP inhibitors as experimental, topically applied, anti-fibrotic drugs for clinical evaluation.
Materials and methods PCP was cloned from human osteosarcoma cells and enzymatic activity demonstrated using a PCP-specific peptide cleavage assay. Activities were confirmed by measuring cleavage of [3 H]C-peptide from type-I pro-collagen. A cell-based fibroplasias model was employed to demonstrate compound efficacy using collagen deposition, liberated C-peptide and histological endpoints. The activities of PCP inhibitors in fibroblast and epithelial in vitro cell proliferation and migration assays, and selectivity vs. a panel of MMPs were also determined.
Discussion In summary, we have identified and characterized potent and selective inhibitors of PCP for progression to clinical studies for investigation as a treatment paradigm for fibrotic disease.
Materials and methods PCP was cloned from human osteosarcoma cells and enzymatic activity demonstrated using a PCP-specific peptide cleavage assay. Activities were confirmed by measuring cleavage of [
Discussion In summary, we have identified and characterized potent and selective inhibitors of PCP for progression to clinical studies for investigation as a treatment paradigm for fibrotic disease.
Results 相似文献
5.
6.
7.
8.
H D White J T Rivers A H Maslowski J A Ormiston M Takayama H H Hart D N Sharpe R M Whitlock R M Norris 《The New England journal of medicine》1989,320(13):817-821
In a double-blind trial comparing two thrombolytic agents as treatment for acute myocardial infarction, we randomized 270 consecutive patients an average (+/- SD) of 2.5 +/- 0.6 hours after the onset of chest pain from a first myocardial infarction--135 to receive intravenous streptokinase (1.5 million units over 30 minutes) and 135 to receive intravenous recombinant tissue plasminogen activator (rt-PA) (100 mg over three hours). The primary end point was left ventricular function as assessed by cineangiography performed three weeks after infarction. The effects of the two agents on left ventricular function were similar. The ejection fraction was identical (58 +/- 12 percent) in both groups. The end-systolic volume was 61 +/- 29 ml in the streptokinase group and 66 +/- 31 ml in the rt-PA group (P not significant). Patency rates at three weeks for the infarct-related artery were also similar (75 percent in the streptokinase group and 76 percent in the rt-PA group). Reinfarction rates at 30 days were the same (5 percent) in both groups. One patient had a fatal intracerebral hemorrhage 13 hours after receiving rt-PA, and another had a fatal cerebellar hemorrhage 21 hours after receiving rt-PA for reinfarction nine days after treatment with streptokinase. An intention-to-treat analysis revealed that mortality at 30 days was 3.7 percent in the rt-PA group as compared with 7.4 percent in the streptokinase group (P greater than 0.2). Follow-up for a mean of 9.0 months revealed no significant difference in survival; we observed 12 deaths (8.9 percent) in the streptokinase group and 8 deaths (5.9 percent) in the rt-PA group (P = 0.34). We conclude that rt-PA and streptokinase, in the doses given, have similar effects on left ventricular function after a first myocardial infarction. Because of the small number of deaths, it is not possible to determine whether their effects on mortality are similar. 相似文献
9.
Interchromosomal duplications of the adrenoleukodystrophy locus: a phenomenon of pericentromeric plasticity 总被引:13,自引:5,他引:13
Eichler EE; Budarf ML; Rocchi M; Deaven LL; Doggett NA; Baldini A; Nelson DL; Mohrenweiser HW 《Human molecular genetics》1997,6(7):991-1002
A 9.7 kb segment encompassing exons 7-10 of the adrenoleukodystrophy (ALD)
locus of the X chromosome has duplicated to specific locations near the
pericentromeric regions of human chromosomes 2p11,10p11, 16p11 and 22q11.
Comparative sequence analysis reveals 92-96% nucleotide identity,
indicating that the autosomal ALD paralogs arose relatively recently during
the course of higher primate evolution (5-10 million years ago). Analysis
of sequences flanking the duplication region identifies the presence of an
unusual GCTTTTTGC repeat which may be a sequence-specific integration site
for the process of pericentromeric- directed transposition. The breakpoint
sequence and phylogenetic analysis predict a two-step transposition model,
in which a duplication from Xq28 to pericentromeric 2p11 occurred once,
followed by a rapid distribution of a larger duplicon cassette among the
pericentromeric regions. In addition to facilitating more effective
mutation detection among ALD patients, these findings provide further
insight into the molecular basis underlying a pericentromeric-directed
mechanism for non- homologous interchromosomal exchange.
相似文献
10.
Two types of phantoms were developed with which to evaluate the overall performance of digital subtraction angiography (DSA) systems. A dynamic phantom, called a "fish bone" phantom, consists of polyethylene tubes that simulate blood vessels with various lesions, such as stenoses, ulcers, and aneurysms. With this phantom, washout curves were obtained representing the relationship between iodine content and time. It will be useful for qualitative assessment of DSA images, evaluation of different image-processing schemes, and studies of blood flow analysis. A static phantom, called a "C-D" phantom, can be used for measurement of quantitative contrast-detail (C-D) diagrams and for daily monitoring of DSA systems. This was constructed of tubes of seven different diameters (2.15-0.28 mm) and 14 different concentrations of contrast medium (100%-1.1% Renografin-76 [meglumine and sodium diatrizoate]). The C-D diagrams were determined from an observer performance study using C-D phantom images obtained at four different DSA settings. 相似文献