全文获取类型
收费全文 | 5774篇 |
免费 | 319篇 |
国内免费 | 34篇 |
专业分类
耳鼻咽喉 | 304篇 |
儿科学 | 62篇 |
妇产科学 | 65篇 |
基础医学 | 909篇 |
口腔科学 | 115篇 |
临床医学 | 319篇 |
内科学 | 1326篇 |
皮肤病学 | 70篇 |
神经病学 | 529篇 |
特种医学 | 182篇 |
外科学 | 769篇 |
综合类 | 60篇 |
预防医学 | 203篇 |
眼科学 | 52篇 |
药学 | 578篇 |
中国医学 | 18篇 |
肿瘤学 | 566篇 |
出版年
2023年 | 27篇 |
2022年 | 65篇 |
2021年 | 113篇 |
2020年 | 66篇 |
2019年 | 83篇 |
2018年 | 95篇 |
2017年 | 78篇 |
2016年 | 93篇 |
2015年 | 79篇 |
2014年 | 131篇 |
2013年 | 152篇 |
2012年 | 229篇 |
2011年 | 307篇 |
2010年 | 142篇 |
2009年 | 130篇 |
2008年 | 240篇 |
2007年 | 257篇 |
2006年 | 234篇 |
2005年 | 280篇 |
2004年 | 302篇 |
2003年 | 249篇 |
2002年 | 226篇 |
2001年 | 242篇 |
2000年 | 239篇 |
1999年 | 207篇 |
1998年 | 70篇 |
1997年 | 72篇 |
1996年 | 79篇 |
1995年 | 55篇 |
1994年 | 66篇 |
1993年 | 52篇 |
1992年 | 158篇 |
1991年 | 146篇 |
1990年 | 139篇 |
1989年 | 120篇 |
1988年 | 118篇 |
1987年 | 113篇 |
1986年 | 113篇 |
1985年 | 96篇 |
1984年 | 68篇 |
1983年 | 54篇 |
1982年 | 33篇 |
1981年 | 24篇 |
1980年 | 22篇 |
1979年 | 39篇 |
1978年 | 26篇 |
1977年 | 27篇 |
1974年 | 23篇 |
1973年 | 18篇 |
1971年 | 20篇 |
排序方式: 共有6127条查询结果,搜索用时 15 毫秒
41.
A 48-year-old female, who had been having episodes of chest discomfort and oppression lasting for several minutes for 15 years was diagnosed as having a single left coronary artery by coronary angiography. The electrocardiogram taken during a chest pain attack demonstrated the depression of the ST-segment in leads II, III, aVF, and V4-6. The chest pain was relieved, and the ischemic change in ECG was improved by sublingual nitroglycerine. 201Thalium single photon emission computed tomography under stress indicated poor uptake in both the anterior and infero-posterior myocardium, which was compatible with the change in ECG either during the attack or during exercise. The anterior myocardial ischemia was reduced by propranolol and the chest pain was successfully relieved by propranolol. The chest pain in this case might have partly been due to the myocardial ischemia in the anterior and infero-posterior myocardium, under stress, which could have been the steal phenomenon to lateral myocardium due to the anatomical anomaly, besides other possible mechanisms for chest pain proposed in the case of single coronary artery. Our findings suggested that 201Thalium stress single photon emission computed tomography is a useful method for detecting the myocardial ischemia in patients with single coronary artery and those suffering from chest pain without any coronary stenosis. 相似文献
42.
T. Nada S. Ichiyama Y. Osada M. Ohta K. Shimokata N. Kato N. Nakashima 《The Journal of hospital infection》1996,32(4):305-317
Staphylococcus aureus isolates were collected from epidemiologically unrelated clinical sources in Japan between 1991 and 1993. A total of 40 isolates, five each of eight coagulase types, were analysed by polymerase chain reaction (PCR) of the coagulase gene, PCR-restriction fragment length polymorphism (RFLP) after AluI digestion, and pulsedfield gel electrophoresis (PFGE) of chromosomal DNA after SmaI digestion. The efficiency of discrimination among the isolates increased in the order of PCR < PCR-RFLP < PFGE, yielding five, 13 and 31 different types, respectively. To assess the clinical use of these methods, 42 additional methicillin-resistant S. aureus (MRSA) isolates collected from 27 inpatients in a hospital were analysed. PFGE and PCR-RFLP were able to discriminate 11 and four types, respectively. PFGE analysis detected cross-infection between four postoperative patients in an intensive-care unit, and in six neonates in intensive care. We conclude that of the three methods tested, PFGE analysis currently allows the most effective discrimination of MRSA strains. 相似文献
43.
Kazunari Okada Yang Il Kim Kimihiro Nakashima Izuru Tada Takanori Yoshida Michio Kobayashi Shigeo Yokoyama 《Surgery today》1993,23(7):626-631
A case of small fibrolamellar hepatocellular carcinoma (HCC) coexistent with a HCC of common type is herein reported. A 56-year-old man was diagnosed as having multi-nodular type HCC with liver cirrhosis. The serum alpha-fetoprotein (AFP) level was slightly increased. The patient underwent a partial caudate lobectomy and lateral segmentectomy. Histologically, both resected tumors were small HCCs measuring less than 2 cm in diameter. One was a fibrolamellar type located in the caudate lobe, while the other was the common type in the lateral segment of the liver. Positive immunohistochemical staining for AFP was observed in the tumor cells of the HCC of common type but was not observed in the fibrolamellar HCC. We also reviewed previously reported cases of fibrolamellar HCC in Japan, and discussed the clinicopathologic implications of this disease. 相似文献
44.
Development of new immunoradiometric assay for CA 125 antigen using two monoclonal antibodies produced by immunizing lung cancer cells 总被引:4,自引:0,他引:4
Mihoko Kunimatsu Keigo Endo Tetsuo Nakashima Toshikazu Awaji Tsuneo Saga Yuji Watanabe Yasutaka Kawamura Hitoya Ohta Mitsuru Koizumi Harumi Sakahara Junji Konishi Shingo Fujii Takahide Mori Kanji Torizuka Yoichiro Matsuoka Tsuyoshi Nakagawa Nobuo Yamaguchi 《Annals of nuclear medicine》1988,2(2):73-79
CA 125 is an antigen associated with non-mucinous epithelial ovarian cancer, which is defined by OC 125 antibody developed by immunizing ovarian cancer cells. We have produced two monoclonal antibodies, 130-22 and 145-9, by using the human lung adenocarcinoma cell line PC-9. Both 130-22 and 145-9 antibodies recognized CA 125 antigen. However, the binding sites seemed to be separate from those of OC 125. Testing by 9 immunoradiometric assays (IRMA), using different combinations of the 3 monoclonal antibodies 130-22, 145-9 and OC 125 demonstrated that the best standard curve for detecting CA 125 could be obtained by a "simultaneous sandwich" assay based on a mixture of 125I-labeled OC 125 and 130-22 or 145-9 coated beads. One-step IRMA, using 130-22 as a tracer and 145-9 as an immunoadsorbent, also showed good reproducibility and sensitivity for measuring CA 125. Antigens were detectable in the culture supernatants of PC-9 cells and 5 of 6 ovarian cancer and endometrial adenocarcinoma cells. These results indicate that one-step IRMA using 130-22 and 145-9 is useful for detecting CA 125 antigen. 相似文献
45.
SOLANUM ACULEATISSIMUM (Solanaceae) plants, which were cultivated in the open field, were harvested once a month from June 1985 to January 1986. The growth matter and content of steroid saponins, aculeatiside A and B which are precursors of steroid hormones in root, were then measured in order to examine their seasonal variations during one vegetation period. The aerial parts of the plants died of chill and frost in January. In November the dry weight of root reached the maximum, and the content of steroid saponins was more than 10% and showed a maximum. The yield of steroid saponins per plant was greatest in November. These results suggest that November is the appropriate time for harvest, and that S. ACULEATISSIMUM can be more useful than the DIOSCOREA species which is now used as a source plant of steroid hormones. 相似文献
46.
M Koizumi K Endo M Kunimatsu H Sakahara T Nakashima Y Kawamura Y Watanabe Y Ohmomo Y Arano A Yokoyama 《Journal of immunological methods》1987,104(1-2):93-102
Radionuclides or anti-cancer drugs may be coupled to antibodies for specific transport to target tissues. We have previously reported that several proteins could be rapidly and efficiently labeled with gallium (67Ga) by using deferoxamine (DFO) as a bifunctional chelating agent. In the present paper, we have described the use of hetero-bifunctional agents for the conjugation of DFO with antibodies and investigated the effect of coupling agents on in vitro properties and biodistribution of 67Ga-labeled antibodies. 67Ga-labeled monoclonal antibodies retained antigen-binding activity when prepared under optimum conditions. The use of hetero-bifunctional reagents, such as succinimidyl 6-maleimido-hexanoate (EMCS) or N-succinimidyl-3-(2-pyridyldithio)-propionate (SPDP), which link thioether bonds and disulfide bridges prevented the formation of polymerized antibodies. Although high non-specific uptake in the liver was observed with radiolabels prepared by the homo-bifunctional agent glutaraldehyde, uptake in the liver was low with conjugates linked by hetero-bifunctional agents. 67Ga-labeled antibodies with thioether bonds showed in vivo stability, but the clearance from the circulation was the fastest with the radiolabel holding disulfide bonds. The coupling reagents used to link DFO and antibodies greatly influenced both in vitro properties and in vivo distribution of labeled antibodies and 67Ga-labeled antibodies provide a good model for the study of coupling methods and biodistribution of antibody conjugates. 相似文献
47.
Association of the insertion/deletion polymorphism of the angiotensin I-converting enzyme gene in patients of migraine with aura 总被引:2,自引:0,他引:2
Kowa H Fusayasu E Ijiri T Ishizaki K Yasui K Nakaso K Kusumi M Takeshima T Nakashima K 《Neuroscience letters》2005,374(2):129-131
Recently, several angiotensin I-converting enzyme (ACE) inhibitors and an angiotensin II receptor blocker were demonstrated to have a clinically important prophylactic effect in migraine. ACE is one of the key enzymes in the rennin-angiotensin-aldosterone system, which modulates vascular tension and blood pressure. In humans, serum ACE levels are strongly genetically determined. Individuals who were homozygous for the deletion (D) allele showed increased ACE activity levels. To investigate the role of ACE polymorphism in headache, we analyzed the ACE insertion (I)/deletion (D) genotypes of 54 patients suffering from migraine with aura (MwA), 122 from migraine without aura, 78 from tension-type headache (TH), and 248 non-headache healthy controls. The ACE D allele were significantly more frequent in the MwA than controls (p<0.01). The incidence of the D/D genotype in MwA (25.9%) was significantly higher than that in controls (12.5%; p<0.01; odds ratio=5.26, 95% confidence interval: 1.69-16.34, adjusted for age and gender). No differences in the remaining groups were found. Our results support the conclusion that the D allele and the D/D genotype in the ACE gene is a genetic risk factor for Japanese MwA. There seems to be a possible relationship between ACE activity and the pathogenesis of migraine. 相似文献
48.
49.
Alipov G Nakayama T Ito M Kawai K Naito S Nakashima M Niino D Sekine I 《Histopathology》2005,47(2):202-208
AIMS: The high incidence of clinically diagnosed prostatic cancer is exceeded by the frequency of tumours detected at autopsy. The Ets-1 proto-oncogene is expressed by a variety of malignant and normal tissues. Therefore, in this study, expression of Ets-1 protein was investigated in 'latent' prostatic cancer detected at autopsy, compared with benign prostatic hyperplasia, normal prostatic tissues and clinical prostatic cancer. METHODS AND RESULTS: Using immunohistochemistry, we analysed Ets-1 expression in 95 prostatic specimens including 19 cases of latent prostatic carcinoma (LPC) and 55 cases of clinical prostatic carcinoma (CPC), 11 cases of benign prostatic hyperplasia (BPH) and 10 cases of normal prostate (NP). Differences in the incidence of LPC and CPC suggest different courses for the biological progression of prostatic cancer. There was a significant difference in the degree of Ets-1 expression in CPC and LPC (P < 0.05). Ets-1 was not expressed in BPH and NP, but in malignant cases (57 of 74; 77.0%) commonly demonstrated immunoreactivity in the tumour cells. In our study the expression of Ets-1 between benign and malignant, and well, moderately and poorly differentiated adenocarcinomas of prostatic cancer showed significant differences. The presence of Ets-1 mRNA was confirmed by in-situ hybridization in human prostatic tissues. CONCLUSION: Our results suggest that Ets-1 might play an important role in carcinogenesis and/or the progression of human prostatic carcinomas. 相似文献
50.
Enhanced expression of type I interferon and toll-like receptor-3 in primary biliary cirrhosis 总被引:6,自引:0,他引:6
Takii Y Nakamura M Ito M Yokoyama T Komori A Shimizu-Yoshida Y Nakao R Kusumoto K Nagaoka S Yano K Abiru S Ueki T Matsumoto T Daikoku M Taniguchi K Fujioka H Migita K Yatsuhashi H Nakashima M Harada M Ishibashi H 《Laboratory investigation; a journal of technical methods and pathology》2005,85(7):908-920