全文获取类型
收费全文 | 28417篇 |
免费 | 1393篇 |
国内免费 | 156篇 |
专业分类
耳鼻咽喉 | 353篇 |
儿科学 | 510篇 |
妇产科学 | 531篇 |
基础医学 | 3818篇 |
口腔科学 | 727篇 |
临床医学 | 2080篇 |
内科学 | 7608篇 |
皮肤病学 | 428篇 |
神经病学 | 2184篇 |
特种医学 | 850篇 |
外科学 | 4482篇 |
综合类 | 120篇 |
一般理论 | 1篇 |
预防医学 | 923篇 |
眼科学 | 543篇 |
药学 | 1973篇 |
中国医学 | 62篇 |
肿瘤学 | 2773篇 |
出版年
2023年 | 142篇 |
2022年 | 304篇 |
2021年 | 541篇 |
2020年 | 299篇 |
2019年 | 334篇 |
2018年 | 520篇 |
2017年 | 407篇 |
2016年 | 481篇 |
2015年 | 492篇 |
2014年 | 713篇 |
2013年 | 854篇 |
2012年 | 1283篇 |
2011年 | 1461篇 |
2010年 | 811篇 |
2009年 | 713篇 |
2008年 | 1381篇 |
2007年 | 1452篇 |
2006年 | 1387篇 |
2005年 | 1357篇 |
2004年 | 1285篇 |
2003年 | 1258篇 |
2002年 | 1298篇 |
2001年 | 923篇 |
2000年 | 953篇 |
1999年 | 850篇 |
1998年 | 341篇 |
1997年 | 249篇 |
1996年 | 235篇 |
1995年 | 212篇 |
1994年 | 204篇 |
1993年 | 164篇 |
1992年 | 613篇 |
1991年 | 643篇 |
1990年 | 545篇 |
1989年 | 555篇 |
1988年 | 536篇 |
1987年 | 508篇 |
1986年 | 440篇 |
1985年 | 436篇 |
1984年 | 324篇 |
1983年 | 245篇 |
1979年 | 238篇 |
1978年 | 134篇 |
1977年 | 141篇 |
1974年 | 129篇 |
1973年 | 119篇 |
1972年 | 138篇 |
1971年 | 130篇 |
1969年 | 137篇 |
1967年 | 129篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
111.
112.
T. Otsuka H. Zaraket T. Takano K. Saito S. Dohmae W. Higuchi T. Yamamoto 《Clinical microbiology and infection》2007,13(3):325-327
In total, 269 methicillin-resistant Staphylococcus aureus (MRSA) and 434 methicillin-susceptible S. aureus (MSSA) isolates were investigated to determine their macrolide-lincosamide-streptogramin B (MLS(B)) resistance phenotypes and genotypes. The constitutive phenotype (61.3% in MRSA, 1.3% in MSSA) and erm(A) gene predominated among the 261 erythromycin-resistant MRSA isolates, while the inducible phenotype (38.7% in MRSA, 94.0% in MSSA) and erm(C) gene were more prevalent among the 150 erythromycin-resistant MSSA isolates. There was a higher incidence of the MLS(B) inducible phenotype compared with other countries, perhaps because MLS(B) antibiotics are not recommended as first-line agents against S. aureus in Japan. 相似文献
113.
Four cases of trigeminal schwannoma with different clinical presentations are reported. Two patients had root-type tumors and two ganglion-type tumors. Computed tomography demonstrated the mass in each case, but extension of the tumor into Meckel's cave, displaced but uninvolved seventh and eighth cranial nerves, extension of the tumor into the orbit or into the infratemporal fossa, and other anatomical details were far more clearly shown by magnetic resonance imaging, which provided confirmation of the mass lesions in the base of the brain and within the posterior fossa. 相似文献
114.
S Arai C Arai M Fujimaki Y Iwamoto M Kawarada Y Saito Y Nomura T Suzuki 《Journal of comparative pathology》1991,104(4):439-441
Cutaneous tumour-like growths were observed on the face and other areas of the body surface of young Chilean flamingos. In the cells of these lesions, avian pox-specific cytoplasmic inclusion bodies were observed by light microscopy and virus particles were detected under an electron-microscope. It was diagnosed as avian pox. 相似文献
115.
H Saito K Kishi M Narita T Furukawa E Nagura T Maekawa T Abe A Shibata 《Leukemia research》1992,16(3):217-226
To test the relationship between DMs and drug resistance in newly established AML cell lines, KY821, and its clone KY821A3, the latter had lost DMs during cloning, were cultured in increasing concentrations of MTX. KY821 became resistant against 2 x 10(-4) M MTX, whereas KY821A3 did against 2 x 10(-5) M MTX in a same period. Enhanced enzyme activities of DHFR were correspondent to the increased DMs numbers and DHFR gene amplification in both resistant clones. The amplified DHFR gene was located on DMs by in situ hybridization. These data indicated that the presence of DMs in KY821 would facilitate the acquisition of drug resistance. 相似文献
116.
Shiro Saito Makoto Hata Ryuichi Fukuyama Kosuke Sakai Jun Kudoh Hiroshi Tazaki Nobuyoshi Shimizu 《International journal of urology》1997,4(2):178-185
Background Mutation converts the H-ras gene into an activated oncogene in about 10% of human bladder cancers. Codons 12 and 61 are the major "hot spots" for activation. A simple and accurate method to detect point mutations in these codons may be clinically useful for early diagnosis of bladder cancer.
Methods Bladder cancer samples from 50 patients, plus 10 samples of normal bladder mucosa, were analyzed for possible point mutation of the H-ras gene at either codon 12 or codon 61. The H-ras gene DNA segments that include these 2 codons were amplified by PCR methods, then the possible presence of a point mutation was evaluated at each codon by susceptibility of the respective DNA segments to digestion with the restriction enzyme and by dot blot hybridization assay. A bladder cancer patient who had an H-ras gene mutation was examined to see whether the mutation was also detectable in the cells released in the urine.
Results Definite or possible point mutations were found in 6 (1 2%) out of 50 bladder cancer patients, while no mutation was detected in normal mucosa. A point mutation could also be detected in cells isolated from the patient's urine sample.
Conclusion The prevalence of point mutations at codon 1 2 or codon 61 of the H-ras gene found in this study was similar to that previously estimated for human bladder cancer by DNA transfection assay. The method we have used for detecting point mutations of the H-ras gene provides a simple and highly accurate way to detect mutated cancer cells even in the urine. It may be clinically usable for early diagnosis of bladder cancer. 相似文献
Methods Bladder cancer samples from 50 patients, plus 10 samples of normal bladder mucosa, were analyzed for possible point mutation of the H-ras gene at either codon 12 or codon 61. The H-ras gene DNA segments that include these 2 codons were amplified by PCR methods, then the possible presence of a point mutation was evaluated at each codon by susceptibility of the respective DNA segments to digestion with the restriction enzyme and by dot blot hybridization assay. A bladder cancer patient who had an H-ras gene mutation was examined to see whether the mutation was also detectable in the cells released in the urine.
Results Definite or possible point mutations were found in 6 (1 2%) out of 50 bladder cancer patients, while no mutation was detected in normal mucosa. A point mutation could also be detected in cells isolated from the patient's urine sample.
Conclusion The prevalence of point mutations at codon 1 2 or codon 61 of the H-ras gene found in this study was similar to that previously estimated for human bladder cancer by DNA transfection assay. The method we have used for detecting point mutations of the H-ras gene provides a simple and highly accurate way to detect mutated cancer cells even in the urine. It may be clinically usable for early diagnosis of bladder cancer. 相似文献
117.
Haruhiko Ogawa Masaki Fujimura Motoyasu Saito Tamotsu Matsuda Nobuaki Akao Kaoru Kondo 《Clinical autonomic research》1994,4(1-2):19-28
Eosinophilic bronchitis without asthma can cause a persistent non-productive cough which is resistant to bronchodilator therapy. To understand the mechanism of the cough in this disorder, an animal model of eosinophilic bronchitis was developed. Guinea-pigs were treated with transnasal administration of polymyxin B or saline twice a week for 3 weeks. The number of eosinophils in bronchoalveolar lavage fluid increased in polymyxin B-treated animals when compared with those treated with saline. In addition, histological examination showed that the number of eosinophils infiltrated into the tracheal epithelium increased; injury to the tracheal epithelium was greater in polymyxin B-treated animals. The numbers of coughs induced by saline and each concentration of capsaicin (10–18, 10–16, 10–14M) were greater in the polymyxin B-treated animals. FK-224 (a neurokinin receptor antagonist) decreased the heightened cough reflex in this animal model of eosinophilic bronchitis. These findings suggest that neuropeptides, and particularly neurokinins, are involved in the heightened cough receptor sensitivity in eosinophilic bronchitis without asthma. This has implications for better understanding of this disorder and its treatment. 相似文献
118.
Yasuna Kobayashi Ryoko Sakai Naomi Ohshiro Masayuki Ohbayashi Noriko Kohyama Toshinori Yamamoto 《Drug metabolism and disposition》2005,33(5):619-622
Organic anion transporter 2 (Oat2 [SLC22A7]) is a multispecific organic anion transporter. Although several substrates of human Oat2 (hOat2) have been elucidated, a possible involvement of hOat2 in drug interaction is less defined. The purpose of this study was to investigate the interaction of theophylline with erythromycin mediated by hOat2 using a Xenopus laevis oocyte expression system. When expressed in Xenopus oocytes, hOat2 mediated the transport of theophylline and erythromycin. The finding indicates that the two compounds are novel substrates for hOat2. The apparent K(m) values for the uptake of hOat2 that mediated the transport of theophylline and erythromycin were 12.6 muM and 18.5 muM, respectively. The hOat2-mediated uptake of [(14)C]theophylline and [(14)C]erythromycin was cis-inhibited by adding erythromycin and theophylline, respectively. Our present findings suggest that hOat2 may, at least in part, be involved in the theophylline-erythromycin interaction in the human liver. 相似文献
119.
Y Terada H Suma T Saito S Fukuda T Takayama Y Wanibuchi S Furuta 《Kyobu geka. The Japanese journal of thoracic surgery》1990,43(11):873-877
The long term (10 to 15 years) results of coronary artery bypass grafting (CABG) were studied in 20 patients. The duration of follow-up was ranged from 130 to 170 months with mean 146.4 months. Ten out of 20 patients underwent coronary angiography (CAG), which disclosed that the late patency of saphenous vein (SV) grafts was 68.8% (11/16), but 54.5% (6/11) of patent SV grafts showed atherosclerotic changes such as irregularity and localized narrowing. On the other hand, internal thoracic artery (ITA) grafts were all patent without any atherosclerotic luminal changes. We recognized that ITA grafts were superior to SV grafts from an angiographic standpoint of view in the long term in Japan. 相似文献
120.
Akira Sezai Motomi Shiono Tatsuya Inoue Mitsumasa Hata Mitsuru Iida Tetsuya Niino Akira Saito Tsutomu Hattori Shinji Wakui Masao Soeda Nanao Negishi Yukiyasu Sezai 《Annals of thoracic and cardiovascular surgery》2004,10(3):191-194
The patient was a 48-year-old male who was diagnosed with unstable angina. He had worsening cardiogenic shock during coronary angiography. Emergency coronary artery bypass grafting (CABG) was performed. He had a methicillin-resistant Staphylococcus aureus (MRSA) mediastinitis on day 22 after CABG. Drains were placed in the anterior mediastinum, left thoracic cavity, and abscess cavity, and another drain was placed in the mediastinal space for continuous cleansing with povidone iodine, oxydol. For antibiotics, teicoplanin (TEIC) was administered intravenously and to the local site via the cleansing drain for about one month. No MRSA was detected by culture in discharges from the mediastinal drain. Inflammatory findings were improved, and the patient was discharged and resumed everyday life without recurrence of inflammation as of eight months. Although the number of cases of MRSA mediastinitis is small and accumulation of cases is necessary to investigate therapeutic methods and selection of antibiotics, our department will select closed continuous cleansing and TEIC for antibiotics as the first choice for MRSA mediastinitis, and accumulate cases to investigate its efficacy. 相似文献