全文获取类型
收费全文 | 60069篇 |
免费 | 5352篇 |
国内免费 | 2695篇 |
专业分类
耳鼻咽喉 | 982篇 |
儿科学 | 697篇 |
妇产科学 | 661篇 |
基础医学 | 8394篇 |
口腔科学 | 872篇 |
临床医学 | 6004篇 |
内科学 | 10493篇 |
皮肤病学 | 1607篇 |
神经病学 | 4022篇 |
特种医学 | 3275篇 |
外国民族医学 | 9篇 |
外科学 | 6977篇 |
综合类 | 5465篇 |
现状与发展 | 7篇 |
一般理论 | 19篇 |
预防医学 | 3188篇 |
眼科学 | 1651篇 |
药学 | 6143篇 |
20篇 | |
中国医学 | 2780篇 |
肿瘤学 | 4850篇 |
出版年
2024年 | 223篇 |
2023年 | 861篇 |
2022年 | 2107篇 |
2021年 | 2840篇 |
2020年 | 1705篇 |
2019年 | 1970篇 |
2018年 | 2191篇 |
2017年 | 1889篇 |
2016年 | 2307篇 |
2015年 | 3260篇 |
2014年 | 3686篇 |
2013年 | 3753篇 |
2012年 | 5426篇 |
2011年 | 5318篇 |
2010年 | 3364篇 |
2009年 | 2773篇 |
2008年 | 3336篇 |
2007年 | 3231篇 |
2006年 | 2917篇 |
2005年 | 2651篇 |
2004年 | 2042篇 |
2003年 | 2054篇 |
2002年 | 1777篇 |
2001年 | 1259篇 |
2000年 | 986篇 |
1999年 | 799篇 |
1998年 | 477篇 |
1997年 | 444篇 |
1996年 | 306篇 |
1995年 | 268篇 |
1994年 | 238篇 |
1993年 | 177篇 |
1992年 | 198篇 |
1991年 | 199篇 |
1990年 | 177篇 |
1989年 | 154篇 |
1988年 | 112篇 |
1987年 | 108篇 |
1986年 | 95篇 |
1985年 | 62篇 |
1984年 | 48篇 |
1983年 | 29篇 |
1982年 | 22篇 |
1981年 | 46篇 |
1980年 | 26篇 |
1979年 | 38篇 |
1978年 | 19篇 |
1977年 | 19篇 |
1976年 | 19篇 |
1974年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
Yapu Cao Kaixiang He Qingqing Li Xin Chen Haiying Mo Zhihao Li Qiaolin Ji Ganpeng Li Gang Du Haiying Yang 《Journal of basic microbiology》2023,63(1):17-25
Gastrodia elata is an achlorophyllous and fully mycoheterotrophic orchid which obtains carbon and other nutrients from Armillaria species in its life cycle. Many researchers suggested that plant hormones, as signing molecules, play a central role in the plant–fungi interaction. In the process of Armillaria gallica 012 m cultivation, both exogenous indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) distinctly stimulated the growth of mycelia in solid media. The differential expression genes (DEGs) of A. gallica 012 m with IAA versus blank control (BK) and IBA versus BK were investigated. The results showed that more than 80% of DEGs of the IAA group were coincident with the DEGs of the IBA group, and more than half of upregulated DEGs and most of the downregulated DEGs of the IAA group coincided with those DEGs of the IBA group. Above research implied that A. gallica 012 m could perceive IAA and IBA, and possess similar responses and signaling pathways to IAA and IBA. The overlapping differential genes of the IAA group and IBA group were analyzed by GO term, and the results showed that several DEGs identified were related to biological processes including positive regulation of the biological process and biological process. The downregulated NmrA-like and FKBP_C genes might be benefit to the growth of mycelia. Those results can explain that exiguous IAA and IBA improved the growth of A. gallica to some extent. We speculate that IAA and IBA are signaling molecules, and regulate the expression of growth-related genes of A. gallica 012 m by the same signaling pathway. 相似文献
103.
Second part of an item featuring action research with four different trusts to investigate factors relating to the implementation of the local pay policy. Describes methodologies used, such as clinical team diagnosis and cognitive mapping. Looks at the way forward, listing critical factors in ensuring successful implementation. 相似文献
104.
Ivan Karel Bohdana Kalvodová Martin Filipec Eva Boháčová Petr Soucek Ctibor Povýšil Jiří Vacík Marie Tlusťáková 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》1997,235(3):186-189
Background: The highly swelling poly(glycerol monomethacrylate) gel (polyGLYMA) and hydrophilic polymer poly(triethylenglycol monomethacrylate (polyTEGMA) were tested as potential viscoelastics for intraopertive use in anterior segment surgery. Methods: PolyGLYMA was implanted into the anterior chamber in 5 rabbits, and 40% polyTEGMA in 16 rabbits. The eyes were enucleated 1 week to 3 months after the operation. The corneal endothelium was examined with specular microscopy, and then the whole eye histopathologically. Results: In all eyes of the polyGLYMA group, the clinical findings were characterized by a marked ciliary injection and severe secondary glaucoma, and the histologic ones by a marked inflammatory infiltration and thickening of Descemet's membrane in the anterior chamber angle. Specular microscopy revealed a decrease in the endothelial cell density and polymorphism of the endothelial cells. In the polyTEGMA group, the anterior segment and the fundus were physiologic all the time, and specular microscopy and histologic findings showed no degenerative and/or inflammatory changes. Conclusions: PolyGLYMA proved unsuitable for intracameral application in rabbits. The new polymer polyTEGMA is characterized by high biologic tolerance after its implantation into the anterior chamber of rabbits. PolyTEGMA 40% might be considered as a potential viscoelastic material in humans. 相似文献
105.
Recombinant human epidermal growth factor (rhEGF), a polypeptide of 53 amino acid residues, is subject to degradation by numerous
enzymes, especially proteases, when it is applied on the skin for the treatment of open wound. Amastatin, aprotinin, bestatin,
EDTA, EGTA, gabexate, gentamicin, leupeptin, and TPCK were investigated for the possible protease inhibitors, which may use
to protect rhEGF from degradation by the enzymes in the skin. Skin homogenates containing protease inhibitors and rhEGF were
incubated at 37°C for 30 minutes. After the reaction was stopped with trifluoroacetic acid, the amount of rhEGF remaining
in the sample was determined with an HPLC method. The percentages of rhEGF degraded, at the skin/PBS ratio of 0.25, in the
mouse, rat, and human skin homogenate were 85%, 70%, and 46%, respectively. The degree of degradation of rhEGF in the cytosolic
fraction was higher than that in the membrane fraction and these enzyme reactions were completed in 30 minutes. Bestatin,
EGTA, and TPCK showed significant inhibitory effects on the degradation of rhEGF in the two fractions (p<0.05), while the
other protease inhibitors had no significant inhibitory effects or, even resulted in deleterious effects. Therefore, the formulation
containing one or several inhibitors among these effective inhibitors would be a promising topical preparation of rhEGF for
the treatment of open wound. 相似文献
106.
肾性骨病的骨膜下骨吸收 总被引:4,自引:0,他引:4
笔者采用手骨直接X线放大摄影和双手X线平片来研究慢性肾衰血透病人51例。特征性的指骨骨膜下吸收放大摄影发现25例占49%;平片为11例占21.6%,结果表明,放大摄影的阳性率明显高于平片(P<0.005),骨膜下吸收的二,三指中间指骨桡侧及指骨末端是肾性骨病的“靶区”,认为二者无显著差异(P>0.50)。骨膜下吸收还与血透时间,血磷,血钙和碱性磷酸酶水平相关。 相似文献
107.
Jeffrey M. Trent Barbara Weber X. Y. Guan Ji Zhang Francis Collins Ken Abel Austin Diamond Paul Meltzer 《Breast cancer research and treatment》1995,33(2):95-102
Summary The recognition of recurring sites of chromosome changes in malignancies has greatly facilitated the identification of genes implicated in the pathogenesis of human cancers. Based especially upon recent studies [1–4], it appears increasingly likely that a subset of recurring chromosome alterations will be recognized in human breast cancer. Currently recognized chromosome changes characterizing breast carcinoma include the recognition of cytologic features of gene amplification (e.g. double minutes [dmins] and homogeneously staining regions [HSRs]) [5–8]. As these and other chromosome regions are implicated in recurring abnormalities in breast cancer, it will become increasingly important to have band-or region-specific genomic libraries and probes in order to facilitate high resolution physical mapping and ultimately to clone breast cancer related genes [9]. Toward this end an important recent development in physical mapping has been the establishment of chromosome microdissection as a rapid and reproducible approach to rapidly isolate and characterize chromosome region-specific DNA, greatly facilitating the initial steps in positional cloning of disease-related genes [10–13]. In this brief report, we will highlight the application of chromosome microdissection to the generation of region-specific probes for both fluorescent in situ hybridization (FISH) and the generation of genomic microclone libraries. Additionally, efforts using this methodology to generate a microclone library encompassing the early onset breast/ovarian cancer (BRCA1) gene will be presented.Presented by Jeffrey M. Trent at the 16th Annual San Antonio Breast Cancer Symposium, San Antonio TX, USA, November 4, 1993; Minisymposium on Molecular Genetics in Breast Cancer. 相似文献
108.
A. Vallcanera Calatayud C. Sangüsa Nebot M. Martinez Fernandez H. Cortina Orts 《Pediatric radiology》1994,24(1):74-75
Severe unilateral varus deformity of the distal end of the femur secondary to a focal fibrous lesion is reported. It is a malformative process rare at this level, this being the first report of it in the radiological literature. The conventional radiograph is pathognomonic and CT is useful in the confirmation of the fibrous tissue. Osteotomy is indicated only if the deformity progresses or the angle of varus is severe. 相似文献
109.
目的了解斜角肌间隙内臂丛下干与邻近组织结构及胸1神经干与第1肋的关系,为临床诊治臂丛下干卡压症提供解剖学依据。②方法在21具42侧成人标本上观测臂丛下干与邻近结构的位置关系。③结果在42侧标本的斜角肌间隙内,有33侧在前斜角肌的后内侧存在孤立的肌束,臂丛下干分别从其前下方(23侧)或后上方(10侧)通过;组成臂丛下干的胸1神经干在斜越第1肋前内侧面时部分穿行于骨纤维管内。④结论该肌束的压迫或拱抬均可成为臂丛下干受压的因素之一;组成臂丛下干的胸1神经干在越过第1肋时易受压迫。 相似文献
110.
目的:研究英脱利匹特增强超声多普勒血流信号的作用。方法:在10 只兔中应用经颅超声多普勒检测静脉推注4 种不同剂量(0 .2、0.5、1.0、2.0ml/kg)20 % 英脱利匹特前后的动脉血流信号,并以等量的生理盐水作对照。结果:各种剂量20 % 的英脱利匹特注射后多普勒血流信号强度明显增强, 平均比生理盐水及注射前血流信号强度高26.8±9.7dB。注射生理盐水后多普勒血流信号强度未见明显改变。结论:静脉注射20 % 英脱利匹特能够增强血流信号,提高多普勒检测的敏感性。 相似文献