全文获取类型
收费全文 | 27374篇 |
免费 | 1432篇 |
国内免费 | 102篇 |
专业分类
耳鼻咽喉 | 428篇 |
儿科学 | 515篇 |
妇产科学 | 332篇 |
基础医学 | 3702篇 |
口腔科学 | 667篇 |
临床医学 | 1879篇 |
内科学 | 6798篇 |
皮肤病学 | 682篇 |
神经病学 | 1841篇 |
特种医学 | 1184篇 |
外国民族医学 | 1篇 |
外科学 | 4484篇 |
综合类 | 146篇 |
一般理论 | 2篇 |
预防医学 | 725篇 |
眼科学 | 365篇 |
药学 | 2106篇 |
中国医学 | 80篇 |
肿瘤学 | 2971篇 |
出版年
2022年 | 298篇 |
2021年 | 453篇 |
2020年 | 278篇 |
2019年 | 351篇 |
2018年 | 459篇 |
2017年 | 364篇 |
2016年 | 442篇 |
2015年 | 434篇 |
2014年 | 643篇 |
2013年 | 737篇 |
2012年 | 1201篇 |
2011年 | 1284篇 |
2010年 | 724篇 |
2009年 | 695篇 |
2008年 | 1162篇 |
2007年 | 1318篇 |
2006年 | 1242篇 |
2005年 | 1331篇 |
2004年 | 1256篇 |
2003年 | 1122篇 |
2002年 | 1082篇 |
2001年 | 1038篇 |
2000年 | 972篇 |
1999年 | 916篇 |
1998年 | 322篇 |
1997年 | 228篇 |
1996年 | 252篇 |
1995年 | 198篇 |
1994年 | 162篇 |
1993年 | 200篇 |
1992年 | 637篇 |
1991年 | 553篇 |
1990年 | 536篇 |
1989年 | 535篇 |
1988年 | 516篇 |
1987年 | 489篇 |
1986年 | 463篇 |
1985年 | 431篇 |
1984年 | 316篇 |
1983年 | 263篇 |
1982年 | 162篇 |
1979年 | 247篇 |
1978年 | 161篇 |
1977年 | 185篇 |
1973年 | 178篇 |
1972年 | 187篇 |
1971年 | 190篇 |
1970年 | 173篇 |
1969年 | 186篇 |
1968年 | 172篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
Background: The term 'pigmented epithelioid melanocytoma (PEM)' was recently used for borderline melanocytic tumor/low-grade melanoma including cases previously diagnosed as human animal-type melanoma and epithelioid blue nevus. No Japanese cases have been reported.
Methods: We reviewed 219 cases previously diagnosed as blue nevus in Japan. Common blue nevus was identified in 154 cases and cellular blue nevus in 65 cases.
Results: We have found two Japanese cases of PEM previously diagnosed as cellular blue nevus. Two patients were female. The age at presentation was 32 and 28 years. Two lesions were on the buttock. Two cases fulfilled histological criteria proposed for PEM. There is no evidence of recurrence or metastases.
Conclusions: PEM is a distinct melanocytic tumor and the unifying diagnostic term. PEM is present in Japanese, but these cases may be previously diagnosed as cellular blue nevus. Japanese pathologists should recognize a new concept of PEM, and when they make a diagnosis of PEM, they should be recommended sentinel lymph node sampling. 相似文献
Methods: We reviewed 219 cases previously diagnosed as blue nevus in Japan. Common blue nevus was identified in 154 cases and cellular blue nevus in 65 cases.
Results: We have found two Japanese cases of PEM previously diagnosed as cellular blue nevus. Two patients were female. The age at presentation was 32 and 28 years. Two lesions were on the buttock. Two cases fulfilled histological criteria proposed for PEM. There is no evidence of recurrence or metastases.
Conclusions: PEM is a distinct melanocytic tumor and the unifying diagnostic term. PEM is present in Japanese, but these cases may be previously diagnosed as cellular blue nevus. Japanese pathologists should recognize a new concept of PEM, and when they make a diagnosis of PEM, they should be recommended sentinel lymph node sampling. 相似文献
13.
T Niho C Ito Y Shibutani H Hashizume K Yamaguchi 《Nihon yakurigaku zasshi. Folia pharmacologica Japonica》1986,88(4):309-320
The pharmacological properties of MO-8282 (1,2,3,4-tetrahydro-2-methyl-9H-dibenzo [3,4: 6,7]cyclohepta [1,2-c]pyridine maleate) as an antidepressant were investigated. At doses 10 times less than those of amitriptyline, MO-8282 showed similar potencies in reducing the duration of immobility during forced swimming in rats and in potentiating stereotype induced by L-DOPA. Intermediate doses of MO-8282 reduced the duration of immobility during forced swimming, in mice as well, suppressed muricide behavior of olfactory-bulbectomized rats and antagonized clonidine-induced suppression of exploratory activity in mice. MO-8282 moderately antagonized the ptosis but not the hypothermia induced by reserpine in mice. MO-8282 exhibited weak antagonism against the tremor, lacrimation and diarrhea induced by tremorine, but its activity was milder than that of amitriptyline. The uptake of noradrenaline into rat hypothalamic synaptosomes was inhibited by MO-8282 at concentrations 20 times less than equally effective doses of amitriptyline, but the uptake of dopamine or serotonin was unaffected by MO-8282. A single oral administration of MO-8282 at a dose of 30 mg/kg accelerated noradrenaline turnover, but did not affect dopamine and serotonin turnover in the rat brain. MO-8282 strongly inhibited noradrenaline-, histamine- or adenosine-sensitive adenylate cyclase activity of guinea pig brain. Its mode of action differed from that of imipramine, rather resembling that of mianserin. MO-8282 did not affect monoamine oxidase activity of rat liver. These results suggest that the pharmacological characteristics of MO-8282 are different from those of tricyclic antidepressants and rather similar to those of mianserin, but more potent. The results, therefore, indicate that MO-8282 is possibly a novel antidepressant. 相似文献
14.
Cloning of regions required for contact hemolysis and entry into LLC-MK2 cells from Shigella sonnei form I plasmid: virF is a positive regulator gene for these phenotypes. 总被引:10,自引:5,他引:5
下载免费PDF全文
![点击此处可从《Infection and immunity》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Two distinct regions required for both contact hemolysis and entry into LLC-MK2 cells were cloned into Escherichia coli from the Shigella sonnei form I plasmid, pSS120. The first region was cloned into an E. coli HB101 strain containing noninvasive Tn1 insertion mutants of the form I plasmid, and expression of ipa (invasion plasmid antigen) gene products was restored. The plasmid carrying the first region was then transformed into E. coli lacking the form I plasmid, and additional DNA fragments from the form I plasmid were cloned into the same recipient on compatible vectors. Five of these double transformants were found to be positive for contact hemolysis activity. Restriction analysis of these five clones indicated that the previously reported ipa locus and the invA locus were present on the second plasmid region. Only the strains carrying both of these regions were active in contact hemolysis and cell invasion assays. Several proteins, including the a, b, c, and d proteins encoded by the ipa genes, were detected in the double transformants by Western blot (immunoblot) analysis with serum of a monkey convalescing from shigellosis. A positive regulator was suggested to exist in the first region, since the amounts of most of these proteins were simultaneously increased in the presence of this region. Subcloning and nucleotide sequencing indicated that this positive regulator gene was virF. Product analysis of the virF gene with minicells showed that two peptides (30 and 21 kilodaltons) were synthesized and that at least the 30-kilodalton protein was essential for regulation of the ipa genes. 相似文献
15.
16.
17.
Makoto Osawa Yutaka Ito Toyohiro Hirai Rie Isozumi Shunji Takakura Yasuhiro Fujimoto Yoshitsugu Iinuma Satoshi Ichiyama Koichi Tanaka Michiaki Mishima 《Liver transplantation》2007,13(4):566-570
Invasive aspergillosis (IA) is a severe complication of liver transplantation. Risk factors for IA after deceased donor liver transplantation (DDLT) have been presented in several reports, but are not well established for living donor liver transplant recipients. Here, a retrospective case-control study was performed. Five cases with IA were investigated after living donor liver transplantation (LDLT) between January 1999 and December 2002 at Kyoto University Hospital. For comparison, living donor liver transplant recipients without IA were taken as controls. These patients had undergone LDLT 1 month before or after each IA case and had the same survival times as the latter. We evaluated the clinical and laboratory findings for both groups up until their demise. Patients with IA after LDLT had a very poor prognosis. By univariate analysis, risk factors for IA were preoperative intensive care unit stay (P = 0.02) and preoperative steroid administration (P = 0.02). Preoperative steroid administration for fulminant hepatitis possibly predisposed to the development of IA after LDLT. 相似文献
18.
Hidenobu Takahashi Masahiko Harada Tetsushi Ito Harubumi Kato 《Annals of thoracic and cardiovascular surgery》2007,13(3):191-194
Lymphoepithelioma is a lymphocyte-rich, poorly differentiated and non-keratinizing squamous cell carcinoma of the nasopharynx. Tumors arising outside the nasopharynx are rare and are designated as lymphoepithelioma-like carcinomas (LELCs). This is the third reported case of LELC of the trachea. A 27-year-old woman was referred to our hospital on suspicion of bronchial asthma on August 2000. A polypoid tumor of the cervical trachea was recognized on neck X-ray, neck computed tomography (CT) scan, and fiberoptic bronchoscopy. The protruding tumor was resected endoscopically by an electrosurgical snare. Histological and immunohistochemical examinations demonstrated large irregular polygonal cells extending in an islet or trabecular pattern among lymphoid stroma. These polygonal cells showed non-keratinization, atypia and prominent nucleoli. In situ hybridization showed these cells were infected with the Epstein-Barr (EB) virus. The infiltrating lymphocytes consisted of both T-and B-lymphocytes with no atypia. Thus the tumor was diagnosed as LELC. Blood examination revealed a past EB viral infection. Sphenoid resection of the tracheal cartilaginous portion was performed for residual tumor. We gave 50 Gy postoperative radiation, and she has been disease free in the 6-year follow-up period. 相似文献
19.
Yoshitaka Imoto Naoki Muguruma Tetsuo Kimura Masako Kaji Hiroshi Miyamoto Seisuke Okamura Susumu Ito Masahiko Nakasono Mitsuyoshi Hirokawa Toshiaki Sano 《Nihon Shokakibyo Gakkai zasshi》2007,104(3):401-406
Humoral hypercalcemia of malignancy (HHM) in neoplastic syndrome has been most commonly reported in squamous cell carcinoma. Gallbladder carcinoma with HHM is uncommon. In this report, we describe a male case of gallbladder carcinoma with marked hypercalcemia and a high level of serum parathyroid hormone-related peptide (PTHrP). An immunohistochemical examination using PTHrP was also positive. 相似文献
20.
Yoshinori Igarashi Naoki Okano Ken Ito Takahiko Mimura Kazumasa Miki 《Digestive endoscopy》2007,19(Z1):S109-S114
A 69‐year‐old man was admitted to Toho University Omori Medical Center complaining of icterus. Abdominal computed tomography, magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography were suspicious of cholangioma of inferior bile duct. Peroral cholangioscopy using narrow band imaging (NBI) was performed and it was possible to diagnose the mucosal spread lesions of cholangioma. Histological findings reflected the endoscopic findings. Mucosal spread lesions of cholangiocarcinoma were successfully diagnosed using the CHF‐B260 for NBI. 相似文献