全文获取类型
收费全文 | 8715篇 |
免费 | 384篇 |
国内免费 | 53篇 |
专业分类
耳鼻咽喉 | 101篇 |
儿科学 | 189篇 |
妇产科学 | 78篇 |
基础医学 | 1208篇 |
口腔科学 | 198篇 |
临床医学 | 467篇 |
内科学 | 2208篇 |
皮肤病学 | 229篇 |
神经病学 | 516篇 |
特种医学 | 206篇 |
外科学 | 1527篇 |
综合类 | 16篇 |
一般理论 | 1篇 |
预防医学 | 225篇 |
眼科学 | 143篇 |
药学 | 479篇 |
中国医学 | 12篇 |
肿瘤学 | 1349篇 |
出版年
2023年 | 48篇 |
2022年 | 79篇 |
2021年 | 168篇 |
2020年 | 95篇 |
2019年 | 116篇 |
2018年 | 162篇 |
2017年 | 135篇 |
2016年 | 163篇 |
2015年 | 194篇 |
2014年 | 263篇 |
2013年 | 280篇 |
2012年 | 516篇 |
2011年 | 465篇 |
2010年 | 354篇 |
2009年 | 260篇 |
2008年 | 535篇 |
2007年 | 537篇 |
2006年 | 550篇 |
2005年 | 606篇 |
2004年 | 614篇 |
2003年 | 570篇 |
2002年 | 574篇 |
2001年 | 174篇 |
2000年 | 176篇 |
1999年 | 162篇 |
1998年 | 111篇 |
1997年 | 110篇 |
1996年 | 107篇 |
1995年 | 85篇 |
1994年 | 58篇 |
1993年 | 74篇 |
1992年 | 85篇 |
1991年 | 70篇 |
1990年 | 74篇 |
1989年 | 57篇 |
1988年 | 44篇 |
1987年 | 43篇 |
1986年 | 38篇 |
1985年 | 51篇 |
1984年 | 38篇 |
1983年 | 26篇 |
1982年 | 18篇 |
1981年 | 19篇 |
1980年 | 19篇 |
1979年 | 17篇 |
1978年 | 30篇 |
1977年 | 18篇 |
1974年 | 17篇 |
1972年 | 25篇 |
1970年 | 22篇 |
排序方式: 共有9152条查询结果,搜索用时 0 毫秒
51.
Ochiai K Ishihara C Tomioka H 《International archives of allergy and immunology》1999,118(2-4):443-446
BACKGROUND: We reported on the constitutive interferon-gamma receptor (IFN-gammaR) expression on eosinophils. But signal transduction through IFN-gammaR on eosinophils remains to be elucidated. In this study, we examined the involvement of the Jak/Stat pathway in the signaling of eosinophils after IFN-gammaR conjugation by the ligand binding. METHODS: Purified peripheral eosinophils were stimulated with IFN-gamma at 37 degrees C for 1-60 min. Tyrosine phosphorylation of IFN-gammaR, Jak1, Jak2, and Stat1alpha was examined by immunoblotting. Gel-shift assay was also examined to show the formation of Stat1alpha-DNA complexes. RESULTS: We show that binding of IFN-gamma to human eosinophils initiated a series of events that resulted in the rapid tyrosine phosphorylation of not only the IFN-gammaRalpha chain but also Jak1, Jak2, and Stat1alpha. In addition, IFN-gamma enhanced the DNA-binding activity of Stat1alpha. CONCLUSION: These data indicate that IFN-gamma affects eosinophils through its specific receptor and utilizes the Jak/Stat pathway as its mode of signaling. 相似文献
52.
Akishi Ooi Toru Kameya Masaru Tsumuraya Ken Yamaguchi Kaoru Abe Yukio Shimosato Noboru Yanaihara 《Virchows Archiv : an international journal of pathology》1985,405(3):311-323
Summary Nine pancreatic endocrine tumours of patients with watery diarrhoea hypokalaemia achlorhydria (WDHA) syndrome were examined by immunohistochemistry and electron microscopy. All cases revealed neoplastic proliferation of VIP (vasoactive intestinal peptide)-immunoreactive (IR) cells. Immunoreactivity to a novel peptide hormone PHM-27, which is processed from a common big precursor peptide of VIP (prepro VIP/PHM-27), was identified in VIP-IR cells of 8 tumours. VIP-PHM-IR cells had secretory granules measuring about 130 to 220 nm in diameter. Radioimmunoassay of tumour tissue extracts showed high VIP and PHM contents in proportional amounts in most cases. According to the results of immunostaining, the 8 tumours fell into two large groups; 5 with PP (pancreatic polypeptide)-IR cells and 3 with CT (calcitonin)-IR cells. The former group demonstrated VIP cells and PP cells intermingled in various proportions, including one tumour in which coexistence of PP-IR and VIP-IR in the same cells was demonstrated. Cell heterogeneity of the tumours and possible relationships of VIP, PP and CT cells were discussed.This work was supported in part by Grants-in-Aid for Cancer Research from the Ministry of Health and Welfare and from the Ministry of Education, Science and Culture, Japan 相似文献
53.
54.
Kawada T Yamamoto K Kamiya A Ariumi H Michikami D Shishido T Sunagawa K Sugimachi M 《The Japanese journal of physiology》2005,55(3):157-163
The dynamic characteristics of the baroreflex neural arc from pressure input to efferent sympathetic nerve activity (SNA) reveal derivative characteristics in the frequency range of 0.01 to 0.8 Hz (i.e., the baroreflex gain augments with increasing frequency) and high-cut characteristics in the frequency range above 0.8 Hz (i.e., the baroreflex gain decreases with increasing frequency) in rabbits. The derivative characteristics accelerate the arterial pressure regulation via the baroreflex. The high-cut characteristics preserve the baroreflex gain against pulsatile pressure by attenuating the high-frequency components less necessary for arterial pressure regulation. However, to what extent the carotid sinus baroreceptor transduction from pressure input to afferent baroreceptor nerve activity (BNA) contributes to these characteristics remains unanswered. To test the hypothesis that the carotid sinus pressure-BNA transduction partly explains the derivative characteristics but not the highcut characteristics, we examined the dynamic BNA response to pressure input in the frequency range from 0.01 to 3 Hz by using a white noise analysis in 7 anesthetized rabbits. The transfer function from pressure input to BNA showed slight derivative characteristics in the frequency range from 0.01 to 0.3 Hz with approximately a 1.7-fold increase in dynamic gain, but it showed no high-cut characteristics. In conclusion, the carotid sinus baroreceptor transduction partly explained the derivative characteristics but not the high-cut characteristics of the baroreflex neural arc. The present results suggest the importance of the central processing from BNA to efferent SNA to account for the overall dynamic characteristics of the baroreflex neural arc. 相似文献
55.
Analysis of E-cadherin in diffuse-type gastric cancer using a mutation-specific monoclonal antibody 总被引:16,自引:0,他引:16 下载免费PDF全文
Becker KF Kremmer E Eulitz M Becker I Handschuh G Schuhmacher C Müller W Gabbert HE Ochiai A Hirohashi S Höfler H 《The American journal of pathology》1999,155(6):1803-1809
In-frame deletions from the E-cadherin mRNA, coding for a homophilic cell adhesion molecule, are characteristic for diffuse-type gastric carcinomas. Using immunohistochemical analysis the mutant form cannot be distinguished from normal E-cadherin, making results difficult to interpret. In this study, a rat monoclonal antibody, designated E-cad delta 9-1, was generated against a peptide spanning the fusion junction region between exons 8 and 10. This new epitope is present in an E-cadherin variant that lacks exon 9 from the mRNA due to different splice-site gene mutations. Using Western blotting and immunohistochemistry of E-cadherin-transfected cells, we demonstrate that E-cad delta 9-1 specifically reacts with E-cadherin lacking exon 9 but not with the wild-type protein. No immunoreactivity was observed in 31 nontumorous and embryonal tissues analyzed. In gastric carcinoma specimens known to express mutant E-cadherin mRNA lacking exon 9, E-cad delta 9-1 targets exclusively tumor cells in routine formalin-fixed and paraffin-embedded material from biopsies, primary tumors, and lymph node metastases. In a retrospective series of 172 diffuse-type gastric carcinomas expressing E-cadherin, E-cad delta 9-1 reacted with 22 tumors (13%). This new tumor marker-monoclonal antibody system could open novel avenues for selective diagnosis and specific therapy of a subgroup of diffuse-type gastric cancer patients. 相似文献
56.
Takanori Hirose Tadashi Hasegawa Kunihiko Seki Peng Yang Toshiaki Sano Hiroshi Morizumi Masaru Tsuyuguchi 《Ultrastructural pathology》1996,20(5):451-456
A case is reported of atypical glomus tumor occurring in the posterior inferior mediastinum of a 26-year-old woman complaining of severe back pain. The tumor was composed of atypical small, round tumor cells with scattered mitotic figures. In addition to sheet-like, diffuse proliferation of the tumor cells, some areas of the tumor contained small “glo-moid” cells arranged in organoid and hemangiopericytoma-like patterns. Immunohistochemically, many tumor cells were positive for muscle-type actins and a few cells were focally positive for desmin. Ultrastructural studies revealed smooth muscle features of tumor cells, that is, pinocytotic vesicles, external laminas, dense plaques, and occasional thin filaments with dense bodies. The patient remained well for 5 years and 4 months after the operation without additional radiation and chemotherapy. The tumor was diagnosed as an atypical, or low-grade malignant, glomus tumor morphologically. It seems important to recognize the presence of this type of tumor in sites other than extremities and to differentiate it from other malignant small, round cell tumors. 相似文献
57.
58.
Uehara S Tsuchida M Kanno T Sasaki M Nishikibe M Fukamizu A 《International journal of molecular medicine》2003,11(6):723-727
We previously generated a strain of transgenic mice carrying the human renin gene, hRN8-12, in the background of C57BL/6j. In this study, we discovered that hRN8-12 male mice, but not females, developed obesity starting at 15 weeks of age. The body weight of 60-week-old male transgenic mice was 2 times higher than that of age-matched wild-type mice. Interestingly, male mice heterozygous for the human renin gene showed moderate weight gain compared with transgenic and wild-type mice. Obese hRN8-12 mice exhibited hyperglycemia, hyperinsulinemia, hyperleptinemia, and hyperlipidemia, and increase in weight in the adipose tissue, liver, heart, and kidneys. Histological analysis demonstrated that fatty hRN8-12 mice developed hypertrophy of pancreatic islets and fatty liver. These results suggested that hRN8-12 mice are associated with obesity dependent on the transgene dosage and should be a genetic model for late-onset obesity. 相似文献
59.
The reasons for the high accumulation of glutamate (Glu), aspartate (Asp) and glutamine (Gin) in high K and high glutathione
(HK/HG) dog red blood cells (DRBCs) have been explained as due to enhanced Glu/Asp influxes. However, in our study, Glu/Asp
influxes in high K and low glutathione (HK/LG) DRBCs were low, whereas their cellular Asp and Gin contents were high. In low
K (LK) DRBCs, there were also other variant cells with high Asp accumulation, but extremely low Glu/Asp influxes. So, the
high amino acid accumulation in DRBCs of these new variants might not be due to Glu/Asp influxes. To examine the high accumulation
of these amino acids in these variant DRBCs, first, LK and HK/LG DRBCs were classified into two subgroups with their Na-dependent
Glu/Asp influxes; one had clear Na-dependent Glu/Asp transport (GAT+), and the other failed to have any transport (GAT−). The influxes of both Glu and Asp in HK/HG DRBCs were the highest, and the order was HK/HG>LK/GAT+>HK/LG/GAT+>>LK/GAT−=HK/LG/GAT−. LK/GAT+ cells represented normal DRBCs. Glu/Asp influxes were only trace in both LK/GAT− and HK/LG/GAT− cells, but Glu and Asp concentration was high in HK/LG/GAT− cells whereas Asp concentration was high in LK/GAT− cells. In HK/HG cells, the conversion of Glu into Gin in whole cells was several fold higher than in the other cell groups
due to the differing amount of the substrate of glutamine synthetase, Glu, but glutamine synthetase activity itself was not
different among these cell groups. Furthermore, glutamine synthetase and glutaminase activities were not different among the
cell groups. Therefore, these enzymes were not involved in the high amino acid accumulation. 相似文献
60.
Isao Katayama Masaki Shimizu Myota Miura Masanobu Maruyama Masayuki Kobayashi Yuuichi Iino Masaru Izuo Susumu Wakatsuki 《Virchows Archiv : an international journal of pathology》1984,402(4):353-359
Summary In a study of 277 patients with breast carcinomas, the PAP immunoperoxidase method for demonstrating endogenous estrogen was correlated with the sucrose density gradient (SDG) assay and with histologic and clinical features. The results from the PAP method and SDG assay agreed in 59 of 84 patients (82.1%) on whom both methods were performed. Histologically, the PAP method was positive in 7 of 7 patients with non-invasive carcinomas, in 164 of 233 patients (70.4%) with common invasive ductal carcinoma, and in 21 of 22 of those with special histological types of invasive carcinomas not including Paget's disease, medullary or apocrine carcinoma, where only 5 of 14 were positive. Clinically, 15 of 18 patients with positive endogenous estrogen showed a response to endocrine therapy as opposed to 1 of 9 patients with a negative endogenous estrogen. The mean survival was 31.2 and 15.6 months, respectively for patients with positive and negative endogenous estrogen. Remission for longer than 2 years was seen more often in patients with positive endogenous estrogen. These results suggest a clinical utility of the present PAP method which, therefore, deserves a further trial as an alternative to histochemical methods aiming at the estrogen receptors.This work was supported by Grants-in Aid for Scientific Research from the Ministry of Education, Science, and Culture of Japan (No. 56480119).This paper was presented at the 72nd Annual Meeding of International Academy of Pathology (United States-Canadian Division), Atlanta, Georgia, March 1, 1983. 相似文献