全文获取类型
收费全文 | 1561篇 |
免费 | 72篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 5篇 |
妇产科学 | 4篇 |
基础医学 | 183篇 |
口腔科学 | 10篇 |
临床医学 | 83篇 |
内科学 | 124篇 |
皮肤病学 | 13篇 |
神经病学 | 56篇 |
特种医学 | 16篇 |
外科学 | 30篇 |
综合类 | 143篇 |
预防医学 | 28篇 |
眼科学 | 647篇 |
药学 | 219篇 |
1篇 | |
中国医学 | 41篇 |
肿瘤学 | 39篇 |
出版年
2024年 | 1篇 |
2023年 | 23篇 |
2022年 | 39篇 |
2021年 | 44篇 |
2020年 | 41篇 |
2019年 | 52篇 |
2018年 | 51篇 |
2017年 | 45篇 |
2016年 | 31篇 |
2015年 | 30篇 |
2014年 | 74篇 |
2013年 | 83篇 |
2012年 | 73篇 |
2011年 | 80篇 |
2010年 | 102篇 |
2009年 | 52篇 |
2008年 | 60篇 |
2007年 | 65篇 |
2006年 | 75篇 |
2005年 | 56篇 |
2004年 | 52篇 |
2003年 | 45篇 |
2002年 | 36篇 |
2001年 | 26篇 |
2000年 | 22篇 |
1999年 | 28篇 |
1998年 | 19篇 |
1997年 | 16篇 |
1996年 | 16篇 |
1995年 | 18篇 |
1994年 | 17篇 |
1993年 | 13篇 |
1992年 | 11篇 |
1991年 | 5篇 |
1990年 | 14篇 |
1989年 | 13篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 46篇 |
1984年 | 27篇 |
1983年 | 30篇 |
1982年 | 35篇 |
1981年 | 27篇 |
1980年 | 22篇 |
1979年 | 5篇 |
1978年 | 11篇 |
1977年 | 4篇 |
1975年 | 3篇 |
1970年 | 1篇 |
排序方式: 共有1655条查询结果,搜索用时 15 毫秒
1.
目的研究Stargardt病(Stargardts disease,STGD)的眼底表现和眼底荧光血管造影(fundus fluorescein angiography,FFA)的特征.方法对27例54眼STGD患者进行视力、眼底及FFA检查.结果STGD患者的视力在0.02~0.10者46眼,占85.2%.眼底检查黄斑部均有横径为1.5~3.0 PD大小、呈青灰色并有金箔样反光的横椭圆形萎缩灶,其中15例30眼伴有眼底黄色斑点,占55.6%.FFA检查黄斑部病变为透见荧光,其中8例16眼呈"牛眼"状;22例44眼呈暗脉络膜背景,占81.5%.结论FFA检查在STGD的诊断中极为重要,在病程的不同阶段可有不同FFA表现. 相似文献
2.
79只眼底病患眼的光照黄斑部试验(MPT)结果显示:中心性浆液性脉络膜视网膜病变、老年性黄斑变性渗出型和Rieger型中心性渗出性脉络膜视网膜病变患眼的光照黄斑恢复时间显著延长,其它黄斑部病变患眼也有不同程度的延长。本文结合眼底荧光血管造影和黄斑视野域值试验对光照黄斑部试验的机理进行了探讨。 相似文献
3.
Johannes M. A. Van Gerven Johan P. Boot Herman H. P. J. Lemkes Jaap A. Van Best PhD 《Documenta ophthalmologica. Advances in ophthalmology》1992,80(2):183-188
The morphological base for the impaired function of the blood retinal barrier was studied in 50 eyes of 10 insulin dependent and 21 non-insulin dependent patients with various levels of diabetic retinopathy. The permeability of the blood retinal barrier (PBRB) was determined by vitreous fluorophotometry with correction for autofluorescence, lenstransmission and non-protein bound plasma fluorescein concentration. Morphological abnormalities of diabetic retinopathy assessed by fundus photography and fluorescein angiography were individually scored on a decimal scale and related to the PBRB by multiple regression analysis. The Pbrb was not correlated to morphological abnormalities of non-proliferative retinopathy [(1) microaneurysms, (2) hard exudates, (3) soft exudates, (4) intraretinal hemorrhages, (5) fluorescein leakage, and (6) capillary closure, p > 0.3]. The PBRB was correlated to morphological abnormalities of (pre)proliferative retinopathy [(1) intraretinal microvascular abnormalities (Sirma) and (2) new vessels (Sneo): pbrb = A – B.SIRMA – C.Sneo with PBRB in nm/sec, A = 1.5 ± 0.5, B = 0.9 ± 0.2 and C = 1.7 ± 0.4, R2 = 0.65, p < 0.0001]. It can be concluded that the increased blood retinal barrier permeability in diabetic patients is mainly due to (pre)proliferative abnormalities and not to non-proliferative abnormalities. 相似文献
4.
Cell culture-based influenza vaccine manufacturing is of growing importance. Depending on virus strains, differences in infection dynamics, virus-induced apoptosis, cell lysis and virus yields are observed. Comparatively little is known concerning details of virus–host cell interaction on a cellular level and virus spreading in a population of cells in bioreactors. In this study, the infection of MDCK cells with different influenza A virus strains in lab-scale microcarrier culture was investigated by flow cytometry. Together with the infection status of cells, virus-induced apoptosis was monitored. A mathematical model has been formulated to describe changes in the concentration of uninfected and infected adherent cells, dynamics of virus particle release (infectious virions, hemagglutinin content), and the time course of the percentage composition of the cell population. 相似文献
5.
We studied retrospectively 12 eyes with a solitary choroidal hemangioma in 12 patients over a period of 13 years. A peculiar, even hyperfluorescence of the tumor within the retinal venous phases occurred in all 12 cases. In all but four patients, laser therapy was performed to reduce subretinal fluid and partially destroy the tumor. Two of the three eyes without extensive retinal detachment or cystoid macular edema at the initial visit regained a final vision of 20/30 or better. The remaining 5 patients with the two major complications had a final vision of 20/80 or worse due to degenerative retinal changes. We believe that laser treatment is definitely advisable in the early stages of a circumscribed choroidal hemangioma.The study was performed at the Institute of Ophthalmology, University of Nijmegen. 相似文献
6.
本文用苏州产裂隙灯对3只猕猴双眼黄斑周围视网膜共36个部位进行随机持续光照,视网膜辐照度为226.8mW/cm~2。照射时间分别为30、45、60、90、120、150、180min。用检眼镜、眼底荧光血管造影对光照即刻到2个月的受照区视网膜进行观察。结果:持续光照120min以上,出现视网膜损伤。经统计学计算,本文提出:裂隙灯使用的相对安全时间阈值为98min。并提出多部位投照方法。 相似文献
7.
Miwa Baba Ryozo Oishi Kiyomi Saeki 《Naunyn-Schmiedeberg's archives of pharmacology》1988,337(4):423-428
Summary The effects of opioids on the permeability of the blood-brain barrier (BBB) were examined in mice with sodium fluorescein as an indicator of the permeability. The brain was perfused with saline 30 min after injection of sodium fluorescein (40 mg/kg, i. v.) and examined by fluorometry. Morphine hydrochloride (0.3–10 mg/kg, s. c.) markedly increased the brain level of sodium fluorescein dose-dependently without influencing the plasma level, when administered 20 min before sodium fluorescein injection. Intracerebroventricularly (i. c. v.) injected morphine hydrochloride (0.5 and 1.0 Erg) increased the brain sodium fluorescein level. Buprenorphine (0.1 and 0.5 mg/kg, s. c.) was also effective. However, pentazocine, ethylketazocine, U-50488H and SKF-10047 had no significant influence. The i.c.v. administration of [D-Ala2, McPhe4, Gly(ol)5]enkephalin (0.1 g) and [D-Ala2, D-Leu5]enkephalin (0.5 g) but not of [D-Thr2, Leu5]enkephalin-Thr increased the brain level of sodium fluorescein significantly. A small dose of naloxone (i. p.) significantly inhibited the effects of morphine, buprenorphine, [D-Ala2, McPhe4, Gly(ol)5]enkephalin and [D-Ala3, D-Leu5]enkephalin. ICI-174864 co-administered i. c. v. with [D-Ala2, D-Leu5]enkephalin was ineffective in antagonizing the effect of the latter. These findings suggest that the stimulation of µ opioid receptors results in an increase in BBB permeability to sodium fluorescein.
Send offprint requests to K. Saeki 相似文献
8.
Monoclonal antibodies against human granulocytes and myeloid differentiation antigens 总被引:4,自引:0,他引:4
Patrice Mannoni Anna Janowska-Wieczorek A. Robert Turner Locksley McGann Jean-Michael Turc 《Human immunology》1982,5(4):309-323
Monoclonal antibodies (MCA) were obtained by immunizing BALB/c mice with 99% pure granulocytes from normal donors or with a whole leukocyte suspension obtained from a chronic myelogenous leukemia (CML) patient, and then fusing the mouse spleen cells with a 315–43 myeloma cell clone. Four MCA were selected and studied using ELISA, immunofluorescence, cytotoxicity assays, and FACS analysis. Antibodies 80H.1. 80H.3. and 80H.5 (from normals) and 81H.1 (from CML) detected antigens expressed on neutrophils. Antibodies 80H.1 and 80H.3 (lgG) also reacted with monocytes but not with other blood cell subsets. Antibodies 80H.5 and 81H.1 (lgM) were cytotoxic and reacted strongly with most of the cells of the neutrophil maturation sequence. i.e., myeloblasts, promyelocytes, myelocytes, and mature granulocytes. Antibodies 80H.5 and 81H.1 also inhibited BFU-GM and CFU-E. Antigens recognized by 80H.3. 80H.5, and 81H.1 were expressed both on a proportion of cells from HL.60, KG.1, ML.1, and K562 myeloid cell lines, and on a proportion of blast cells isolated from patients with acute myelogenous leukemia. They were not found on lymphoid cell lines or lymphoid leukemia cells. These MCA recognize either late differentiation antigens expressed on mature neutrophils and monocytes (80H.1 and 80H.3) or early differentiation antigens (80H.5 and 81H.1) specific to the granulocytic lineage. They may be useful for a better definition of those antigens specific to hematopoietic stem cells and their relationship with normal or neoplastic hematopoiesis. 相似文献
9.
M. Vandenbranden J.L. de Coen R. Jeener L. Kanarek J.M. Ruyschaert 《Molecular immunology》1981,18(7):621-631
Interactions between rabbit-γ-immunoglobulins and model membranes (lipid monalayers, planar lipid bilayers, liposomes) have been investigated. No significant interaction was observed with immunoglobulins. However, immunoglobulins dialysed first vs aqueous buffer having pH 2 or 3 and then dialysed against pH 7 buffer presumably adopt a new conformation which allows their bindings to model membranes. This binding is hydrophobic and the immunoglobulin region interacting with the lipid acyl chains is probably located in the heavy chain, as suggested by labelling in this region by a photosensitive probe previously incorporated into the lipid hydrophobic core. Cleavage at the hinge region by papain or pepsin, or heating above 38°C, induces the loss of the hydrophobic conformation responsible for hydrophobic bindings. The binding capacity of immunoglobulins heated above 38°C is restored after momentary dialysis at pH 2. The possible existence of two Ig isomers is discussed in relation to the mechanism of γ-immunoglobulin passage through the endoplasmic membrane and fixation into the plasma membrane. 相似文献
10.
Differential staining of human alpha beta and gamma delta T cells by the fluorescein conjugate of an anti-CD3 monoclonal antibody. 下载免费PDF全文
The enumeration of total T cells, an important function of the clinical immunology laboratory, utilizes antibodies to CD3, the macromolecular complex associated with the antigen-specific receptors of T cells. We compared the ability of some commonly employed commercial anti-CD3 reagents to stain human peripheral blood lymphocytes. Surprisingly, the fluorescein isothiocyanate (FITC) conjugate of Coulter clone T3 (FITC-T3) stained most T cells brightly, but selectively stained gamma delta T cells very dimly or not at all. In contrast, the other anti-CD3 reagents studied (FITC-Leu 4, PE-T3, PE-Leu 4, and indirectly labelled T3 and Leu 4) stained all T cells equivalently. Dual-colour flow cytometric analysis with FITC-T3 and PE-Leu 4 readily demonstrated a FITC-T3-/PE-Leu 4+ population of T cells. This unique population stained dimly or not at all with a combination of anti-CD4 and anti-CD8 monoclonal antibodies and positively with the pan-gamma delta T cell antibody TCR delta 1. Moreover, an excellent correlation was found between the number of FITC-T3-/PE-Leu 4+ cells and the number of TCR delta 1+ cells in 32 normal individuals. Thus, the FITC-T3-/PE-Leu 4+ phenotype accurately marks all gamma delta T cells. In contrast to FITC-T3, both PE-conjugated and unconjugated T3 stained gamma delta T cells brightly. Therefore, T3 binds to an epitope present on all T cells, but fluoresceinylation specifically attenuates this antibody's ability to bind to gamma delta T cells. These findings indicate that the use of FITC-T3 can result in a significant and variable underestimation of peripheral blood T cell number and demonstrate further that the CD3 complexes of human alpha beta and gamma delta T cells are significantly different. 相似文献