全文获取类型
收费全文 | 2501篇 |
免费 | 160篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 77篇 |
儿科学 | 72篇 |
妇产科学 | 46篇 |
基础医学 | 348篇 |
口腔科学 | 72篇 |
临床医学 | 195篇 |
内科学 | 421篇 |
皮肤病学 | 74篇 |
神经病学 | 115篇 |
特种医学 | 231篇 |
外科学 | 312篇 |
综合类 | 107篇 |
预防医学 | 112篇 |
眼科学 | 128篇 |
药学 | 154篇 |
中国医学 | 13篇 |
肿瘤学 | 196篇 |
出版年
2023年 | 21篇 |
2022年 | 41篇 |
2021年 | 76篇 |
2020年 | 56篇 |
2019年 | 60篇 |
2018年 | 78篇 |
2017年 | 46篇 |
2016年 | 63篇 |
2015年 | 72篇 |
2014年 | 78篇 |
2013年 | 129篇 |
2012年 | 130篇 |
2011年 | 166篇 |
2010年 | 101篇 |
2009年 | 105篇 |
2008年 | 130篇 |
2007年 | 125篇 |
2006年 | 103篇 |
2005年 | 113篇 |
2004年 | 107篇 |
2003年 | 88篇 |
2002年 | 72篇 |
2001年 | 77篇 |
2000年 | 49篇 |
1999年 | 36篇 |
1998年 | 38篇 |
1997年 | 36篇 |
1996年 | 30篇 |
1995年 | 38篇 |
1994年 | 20篇 |
1993年 | 10篇 |
1992年 | 18篇 |
1991年 | 26篇 |
1990年 | 19篇 |
1989年 | 25篇 |
1988年 | 31篇 |
1987年 | 30篇 |
1986年 | 21篇 |
1985年 | 18篇 |
1984年 | 15篇 |
1983年 | 18篇 |
1982年 | 10篇 |
1980年 | 16篇 |
1978年 | 9篇 |
1977年 | 16篇 |
1976年 | 9篇 |
1975年 | 16篇 |
1974年 | 10篇 |
1972年 | 9篇 |
1971年 | 11篇 |
排序方式: 共有2673条查询结果,搜索用时 0 毫秒
11.
I?Satish?RaoEmail author Anand?C?Loya KS?Ratnakar VR?Srinivasan 《BMC clinical pathology》2005,5(1):11
Background
Lymph node infarction is known to occur in association with many non-neoplastic and neoplastic conditions however its occurrence in association with DIC is not reported hitherto in the literature. 相似文献12.
The dynamics of synthesis of alpha-fetoprotein (AFP) and albumin have been studied in rat and man by immunocytochemical localization of each protein in the liver and its quantitation in serum at different periods of normal intrauterine and extrauterine life. The proteins are present only in the cytoplasm of hepatocytes. During physiologic development, an inverse relationship exists between the serum concentrations of the two proteins, the latter for each appearing to be directly related to the number of hepatocytes synthesizing it. AFP-containing cells are randomly distributed, while albumin-containing cells are more uniformly spread out. Both, however, are often preferentially located around venous channels. In the case of AFP-containing cells, the last to disappear with advancing postnatal age are seen around the hepatic veins. When both proteins are present in serum, several hepatocytes seem to syntehsize the two simultaneously, though others contain only one of them. It is unlikely that in the physiologic state different populations of hepatocytes are assigned to synthesize AFP and albumin separately. 相似文献
13.
Primary and revision total knee arthroplasty have become common orthopaedic procedures. The operating surgeon, at times, may be faced with a difficult surgical case due to soft tissue contractures or bone deformities. A review of multiple surgical techniques using soft tissue releases and osteotomies are presented including their potential complications. Although these techniques are aimed at the atypical operative case, the operating surgeon may utilize them for ‘routine’ exposures as well. Importance is focused on the functional integrity of the knee extensor mechanism. 相似文献
14.
15.
Frederic Shapiro Christopher Cahill George Malatantis Ramesh C. Nayak 《Anatomical record (Hoboken, N.J. : 2007)》1995,241(1):39-48
Background: The immunogold labeling technique and transmission electron microscopy were used to demonstrate the expression and position of the intermediate filament vimentin in rat osteoblast and osteocyte cell bodies and cell processes. Conventional light and transmission electron microscopic studies of bone cells demonstrated adjacent cell linkage to be mediated by osteoblast and osteocyte processes present within the canalicular system traversing the bone matrix. The cell processes were filled with densely packed filaments, many of which have been shown previously to be actin microfilaments. The appearance, however, of 10 nm diameter filaments in some cell processes and the fact that the intermediate filament vimentin has been defined in many cells of mesenchymal origin raised the possibility that some of these filaments might be vimentin. The ultrastructural colloidal gold immunochemical technique allowed for demonstration in situ of the expression of vimentin filaments plus accurate definition of their position. Methods: The studies were performed in newborn rat femoral and tibial diaphyseal cortical bone and in 1-week-old repair bone from 2.4 mm diameter defects made through the lateral cortex in 6-week-old rat femurs and tibias. The bone tissues for the immunochemical study were fixed in 1% glutaraldehyde, 4% paraformaldehyde, and 0.1 M phosphate buffer (pH 7.4) for 2 days. Decalcification was performed in 6% EDTA for 2–3 days. Infiltration involved use of Lowicryl resin K4M, and the embedding and curing processes were performed in a cryostat with temperatures ?30°C. An antivimentin monoclonal antibody was used for labeling using the postembedding technique. Effective antibody dilutions ranged from 1:10 to 1:200, with the dilutions of 1:25 and 1:100 showing the best combination of filament labeling with the least matrix background. The grids were exposed to 10 nanometer gold colloid conjugated goat anti-mouse IgM for demonstration of binding. Results: Vimentin immunolabeling was defined clearly in relation to filaments within the osteoblast and osteocyte cell body cytoplasm, throughout the entire length of the osteoblast and osteocyte cell processes, and in close relationship to the intercellular gap junctions which were present within the cell processes both close to the cell bodies and within the canaliculi well away from them. Conclusions: Immunogold labeling demonstrates the presence of the intermediate filament vimentin in osteoblast and osteocyte cell bodies and processes of rat bone. Vimentin distribution is not concentrated to specific areas, is present throughout the extent of the bodies and processes, and is seen immediately adjacent to gap junctions. © 1995 Wiley-Liss, Inc. 相似文献
16.
Establishment of a human hepatocellular carcinoma cell line releasing hepatitis B virus surface antigen 总被引:4,自引:0,他引:4
P K Das N C Nayak K N Tsiquaye A J Zuckerman 《British journal of experimental pathology》1980,61(6):648-654
A new hepatocellular carcinoma cell line, DELSH-5, derived from operative wedge biospy from a HBsAg sero- and tissue-positive patient, has been continuously propagated in vitro for nearly 22 months. The cells not only resemble hepatocytes on light and electron microscopic examination but also possess biosynthetic markers of the latter such as albumin and alpha-foetoprotein which were demonstrated in the supernatant medium as well as in the tumour cell cytoplasm. Karyology of cloned cells shows moderate aneuploidy, the major model chromosome number being 61. Though in the initial few passages HBsAg could not be detected, from the 13th passage onwards this viral component could be consistently demonstrated in small amounts in the concentrated supernatant medium by the macro- and micro-ELISA techniques. The immunohistochemical techniques as well as electron microscopy have failed to demonstrate any virus component inside the cell. The cell line reported here is the third of its kind which will act as a useful laboratory model to obtain pure HBsAg and to study the hepatitis-B-virus--liver-cell interaction with particular reference to the oncogenic potential of the virus. 相似文献
17.
18.
Lamm WJ Starr IR Neradilek B Polissar NL Glenny RW Hlastala MP 《Respiratory physiology & neurobiology》2004,144(2-3):281-294
Hypoxic pulmonary vasoconstriction (HPV) is thought to protect gas exchange by decreasing perfusion to hypoxic regions. However, with global hypoxia, non-uniformity in HPV may cause over-perfusion to some regions, leading to high-altitude pulmonary edema. To quantify the spatial distribution of HPV and regional PO2 (PRO2) among small lung regions (approximately 2.0 cm3), five prone beagles (approximately 8.3 kg) were anesthetized and ventilated (PEEP approximately 2 cm H2O) with an F1O2 of 0.21, then 0.50, 0.18, 0.15, and 0.12 in random order. Regional blood perfusion (Q), ventilation (VA) and calculated PRO2 were obtained using iv infusion of 15 microm and inhalation of 1 microm fluorescent microspheres. Lung pieces were clustered by their relative blood flow response to each F1O2. Clusters were shown to be spatially grouped within animals and across animals. Lung piece resistance increased as PRO2 decreased to 60-70 mmHg but dropped at PRO2's < 60mmHg. Regional ventilation changed little with hypoxia. HPV varied more in strength of response, rather than PRO2 response threshold. In initially homogeneous VA/Q lungs, we conclude that HPV response is heterogeneous and spatially clustered. 相似文献
19.
20.
Acute porphyria is rare in orientals. We describe a Chinese woman with recurrent generalised tonic-clonic seizures and abdominal pain. Genomic DNA studies identified a heterozygous base substitution from guanine to adenine at nucleotide position 503, resulting in substitution of arginine by histidine at position 168 of the protein (R168H). This genetic abnormality is similar to the mutation reported in Caucasians with variegate porphyria. To the best of our knowledge, this is the first report in the English literature a Chinese patient with variegate porphyria with an identifiable mutation. A brief review of porphyria is presented. 相似文献