全文获取类型
收费全文 | 17276篇 |
免费 | 821篇 |
国内免费 | 154篇 |
专业分类
耳鼻咽喉 | 205篇 |
儿科学 | 424篇 |
妇产科学 | 153篇 |
基础医学 | 2110篇 |
口腔科学 | 464篇 |
临床医学 | 1051篇 |
内科学 | 4756篇 |
皮肤病学 | 327篇 |
神经病学 | 1127篇 |
特种医学 | 780篇 |
外科学 | 2824篇 |
综合类 | 54篇 |
预防医学 | 401篇 |
眼科学 | 211篇 |
药学 | 1022篇 |
中国医学 | 31篇 |
肿瘤学 | 2311篇 |
出版年
2024年 | 13篇 |
2023年 | 142篇 |
2022年 | 263篇 |
2021年 | 505篇 |
2020年 | 280篇 |
2019年 | 333篇 |
2018年 | 435篇 |
2017年 | 338篇 |
2016年 | 423篇 |
2015年 | 430篇 |
2014年 | 521篇 |
2013年 | 719篇 |
2012年 | 1051篇 |
2011年 | 1212篇 |
2010年 | 656篇 |
2009年 | 559篇 |
2008年 | 1020篇 |
2007年 | 1177篇 |
2006年 | 1070篇 |
2005年 | 1130篇 |
2004年 | 1116篇 |
2003年 | 1024篇 |
2002年 | 1032篇 |
2001年 | 216篇 |
2000年 | 204篇 |
1999年 | 213篇 |
1998年 | 273篇 |
1997年 | 203篇 |
1996年 | 184篇 |
1995年 | 176篇 |
1994年 | 172篇 |
1993年 | 171篇 |
1992年 | 111篇 |
1991年 | 125篇 |
1990年 | 96篇 |
1989年 | 78篇 |
1988年 | 68篇 |
1987年 | 51篇 |
1986年 | 54篇 |
1985年 | 49篇 |
1984年 | 39篇 |
1983年 | 33篇 |
1982年 | 47篇 |
1981年 | 32篇 |
1980年 | 30篇 |
1979年 | 27篇 |
1978年 | 25篇 |
1977年 | 13篇 |
1976年 | 16篇 |
1974年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
Gerhard Opelz Masahiro Kiuchi Mitsuo Takasugi 《International journal of immunogenetics》1975,2(1):1-7
Loss of antigenicity in the mixed lymphocyte culture (MLC) reaction of lymphocytes precultured at 22°C for 7–10 days was accompanied by a decrease in bone-marrow-derived lymphocytes (B cells) from 22 ± 1% to 13 ± 1%, and an increase in thymus-derived lymphocytes (T cells) from 65 ± 2% to 83 ± 1% (P < 0.001). Depletion of B cells from a fresh lymphocyte suspension by either antihuman immunoglobulin-coated column fractionation or by sheep red blood cell (SRBC) rosette formation resulted in a significant reduction of the cell's ability to stimulate in MLC (P < 0.001). Coating of lymphocytes with rabbit antihuman brain serum abrogated their ability to respond but not the ability to stimulate in MLC. 相似文献
83.
Qiang Liu Koichi Ohshirna Yuichi Masuda Masahiro Kikuchi 《Pathology international》1995,45(2):131-136
The Epstein-Barr virus (EBV) has been shown to be associated with numerous human malignancies including Burktt's lymphoma and nasopharyngeal lymphoepithelioma. In addition, some typical gastric adenocarcinomas were also recently reported to demonstrate EBV relevance. The present study was designed to detect EBV in primary gastric lymphoma, using the in situ hybridization (ISH) method, in which oligo-nucleotide probes for the EBERl RNA and the EBV DNA W region have been used. Of the 49 cases of primary gastric lymphoma studied, which all showed B cell immunopheno-type, EBER1 sequences could only be found in four cases, including two low-grade cases and two high-grade cases of histological subtypes while the number of positive cells was less than 50% of the tumor cells. In one case of low-grade mucosa associated lymphoid tissue (MALT) lymphoma, the EBER1 -positive neoplastic cells were found in the regional lymph node, but the primary site of the stomach showed no positive signals. The EBV presence was further confirmed by the EBV DNA ISH. Using the ISH method, rare or occasional positive lymphoid cells (probably non-tumorous bystander cells) could be detected in 10 other cases including all histological subtypes. The present study shows that only a small proportion of primary gastric lymphoma is associated with EBV, and such positive cases could be found in both high- and low-grade histological subtypes. It is also suggested that the EBV presence in the neoplastic cells of some cases of primary gastric lymphoma is most likely a secondary phenomenon. 相似文献
84.
Ura Hitoshi; Denda Ayumi; Yokose Yoshihiko; Tsutsumi Masahiro; Konishi Yoichi 《Carcinogenesis》1987,8(11):1595-1600
The effects of dietary vitamin E (VE) on the steps of hepatocarcinogenesis,the induction and growth of -glutamyltranspeptidase (GGT)-positivefoci and their evolution into persistent nodules, were analyzedin the liver of rats treated with diethylnitrosamine (DEN).The induction of GGT-positive foci was inhibited by a diet containing0.361.5% VE given after initiation with 200 mg/kg bodyweight (b.w.) DEN for 6 weeks with partial hepatectomy (PH)on week 3. The numbers and areas of GGT-positive foci were enhancedby diets containing 036 and 0.72% VE, given for 1 week afterinitiation with 10 mg/kg b.w. DEN and PH, followed by selectionby 0.02/ 2-acetylaminofluorene (AAF) and carbon tetrachloride(CCl4), but these were not enhanced by a diet containing 1.5%VE. Remodeling of hyperplastic nodules was not affected by thediet containing 0.72% VE given after initiation with DEN andselection for 12 weeks. The staining characteristics of GGTwere different between remodeling and persistent nodules, exceptfor those of the glutathione-S-transferase placental form (GST-P).The results obtained suggest that VE could prevent the veryearly events during hepatocarcinogenesis, the induction of phenotypicallyaltered foci, but could no longer affect the later stages, theevolution of foci into persistent nodules. 相似文献
85.
Persistent effect of a low dose of preadministered diethylnitrosamine on the induction of enzyme-altered foci in rat liver 总被引:1,自引:0,他引:1
Takahashi Seiichi; Tsutsumi Masahiro; Nakae Dai; Denda Ayumi; Kinugasa Tetsuo; Konishi Yoichi 《Carcinogenesis》1987,8(4):509-513
The effect of a low dose of preadministered diethylnitrosamine(DEN) on the induction of enzyme-altered foci in the liversof male full-grown Fischer 344 rats was studied. As a pretreatment,DEN at a dose of 10 mg/kg body wt was injected i.p. At varioustimes after DEN pretreatment a complete initiation, consistingof administration of the same dose of DEN by the same routein rats subjected to partial hepatectomy (PH), was performed,followed by application of selection pressure. Enzyme-alteredfoci stained with -glutamyltrans-peptidase (-GTP) and glutathioneS-transferase placental form (GST-P) were then assayed. Decreasesin the numbers and areas of foci in the rats which receivedsaline + PH 14 or 28 days after DEN pretreatment were observedin comparison with rats which received saline + PH immediatelyafter DEN. On the other hand, the numbers and areas of fociwere not decreased in rats which received the complete initiation,consisting of DEN + PH, at various times after DEN pretreatmentwhen compared with rats which received these at the same timeas the DEN pretreatment. This persistent effect of DEN pretreatmenton the complete initiation lasted up to 182 days after the timeof DEN pretreatment. In this experiment, GST-P was found tobe a more sensitive marker for the detection of putative preneoplasticliver-cell foci than -GTP. 相似文献
86.
Kouya Hattori Masahiro Akiyama Natsumi Seki Kyosuke Yakabe Koji Hase Yun-Gi Kim 《Nutrients》2021,13(6)
While poorly-absorbed sugar alcohols such as sorbitol are widely used as sweeteners, they may induce diarrhea in some individuals. However, the factors which determine an individual’s susceptibility to sugar alcohol-induced diarrhea remain unknown. Here, we show that specific gut bacteria are involved in the suppression of sorbitol-induced diarrhea. Based on 16S rDNA analysis, the abundance of Enterobacteriaceae bacteria increased in response to sorbitol consumption. We found that Escherichia coli of the family Enterobacteriaceae degraded sorbitol and suppressed sorbitol-induced diarrhea. Finally, we showed that the metabolism of sorbitol by the E. coli sugar phosphotransferase system helped suppress sorbitol-induced diarrhea. Therefore, gut microbiota prevented sugar alcohol-induced diarrhea by degrading sorbitol in the gut. The identification of the gut bacteria which respond to and degrade sugar alcohols in the intestine has implications for microbiome science, processed food science, and public health. 相似文献
87.
Fumie Takewaki Hanako Nakajima Daiki Takewaki Yoshitaka Hashimoto Saori Majima Hiroshi Okada Takafumi Senmaru Emi Ushigome Masahide Hamaguchi Masahiro Yamazaki Yoshiki Tanaka Shunji Nakajima Hiroshi Ohno Michiaki Fukui 《Nutrients》2021,13(6)
The aim of this research was to reveal the characteristics of gut microbiome altered by acarbose intervention in Japanese patients with type 2 diabetes (T2D) and its possible association with habitual dietary intake. Eighteen patients with T2D were administered acarbose for four weeks. The abundances of two major phyla, namely Actinobacteria and Bacteroidetes, were reciprocally changed accompanied by the acarbose intervention. There were also significant changes in the abundances of ten genera, including the greater abundance of Bifidobacterium, Eubacterium, and Lactobacillus and the lower abundance of Bacteroides in the group after the intervention than that before the intervention. Hierarchical clustering of habitual dietary intake was performed based on the pattern of changes in the gut microbiota and were classified into distinct three clusters. Cluster I consisted of sucrose, cluster II mainly included fat intake, and cluster III mainly included carbohydrate intake. Moreover, the amount of change in Faecalibacterium was positively correlated with the intake of rice, but negatively correlated with the intake of bread. The intake of potato was negatively correlated with the amount of change in Akkermansia and Subdoligranulum. Acarbose altered the composition of gut microbiome in Japanese patients with T2D, which might be linked to the habitual dietary intake. 相似文献
88.
89.
90.
Background/PurposeWe examined the effects and mechanisms of rikkunshito (RKT) and hangeshashinto (HST) on cisplatin-induced mucosal injuries in the rat small bowel.MethodsJuvenile rats were divided into 6 groups: sham control, cisplatin injection without kampo medicines, and cisplatin injection with oral administration of low and high doses of RKT (1000 mg/kg and 2000 mg/kg) and HST (500 mg/kg and 1000 mg/kg). Fecal condition, intestinal morphological changes, enterocyte proliferation, and enterocyte apoptosis were assessed.ResultsDiarrhea and atrophy of ileal villi observed in the cisplatin group were significantly improved in all kampo groups. Injury scores of the jejunum were significantly lower with RKT (2000 mg/kg) and HST (500 and 1000 mg/kg) than with cisplatin, and those of the ileum were significantly lower with HST (500 and 1000 mg/kg) than with cisplatin. Enterocyte proliferation of the jejunum was significantly increased with RKT (2000 mg/kg) and HST (500 mg/kg) compared with cisplatin, and those of the ileum were significantly increased in all kampo groups compared with the cisplatin group. Jejunal and ileal apoptosis following cisplatin administration was significantly inhibited by HST.ConclusionsRKT and HST prevented cisplatin-induced intestinal mucosal injury with increasing proliferation of intestinal epithelial cells. HST also attenuated cisplatin-induced crypt cell apoptosis. 相似文献