全文获取类型
收费全文 | 28115篇 |
免费 | 1851篇 |
国内免费 | 370篇 |
专业分类
耳鼻咽喉 | 536篇 |
儿科学 | 378篇 |
妇产科学 | 404篇 |
基础医学 | 4716篇 |
口腔科学 | 363篇 |
临床医学 | 2353篇 |
内科学 | 5421篇 |
皮肤病学 | 1291篇 |
神经病学 | 2012篇 |
特种医学 | 2079篇 |
外科学 | 3235篇 |
综合类 | 95篇 |
现状与发展 | 1篇 |
一般理论 | 4篇 |
预防医学 | 1039篇 |
眼科学 | 826篇 |
药学 | 2776篇 |
中国医学 | 423篇 |
肿瘤学 | 2384篇 |
出版年
2024年 | 21篇 |
2023年 | 222篇 |
2022年 | 795篇 |
2021年 | 1065篇 |
2020年 | 616篇 |
2019年 | 833篇 |
2018年 | 959篇 |
2017年 | 801篇 |
2016年 | 1261篇 |
2015年 | 1684篇 |
2014年 | 1903篇 |
2013年 | 2084篇 |
2012年 | 2932篇 |
2011年 | 2685篇 |
2010年 | 1797篇 |
2009年 | 1389篇 |
2008年 | 1662篇 |
2007年 | 1562篇 |
2006年 | 1331篇 |
2005年 | 1219篇 |
2004年 | 911篇 |
2003年 | 780篇 |
2002年 | 670篇 |
2001年 | 181篇 |
2000年 | 145篇 |
1999年 | 112篇 |
1998年 | 93篇 |
1997年 | 79篇 |
1996年 | 54篇 |
1995年 | 52篇 |
1994年 | 42篇 |
1993年 | 35篇 |
1992年 | 40篇 |
1991年 | 39篇 |
1990年 | 28篇 |
1989年 | 32篇 |
1988年 | 26篇 |
1987年 | 28篇 |
1986年 | 21篇 |
1985年 | 22篇 |
1984年 | 22篇 |
1983年 | 14篇 |
1982年 | 9篇 |
1981年 | 14篇 |
1980年 | 8篇 |
1979年 | 8篇 |
1978年 | 9篇 |
1973年 | 6篇 |
1971年 | 6篇 |
1967年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
4-1BB(CD137) is a member of the tumour necrosis factor receptor superfamily and is expressed on activated T cells, monocytes and natural killer (NK) cells. The interaction of 4-1BB and 4-1BB ligand provides a costimulatory signal leading to T-cell activation. The expression of 4-1BB has been known to be activation dependent. Interestingly, we found that expression of 4-1BB increased in human peripheral blood mononuclear cells after exposure to mitomycin C. Thus, we tested whether the treatment with other DNA-damaging agents, such as doxorubicin, bleomycin, and gamma-irradiation, could induce 4-1BB expression. The data indicated that 4-1BB expression increased dose-dependently by these agents reaching maximum at 2-3 days after the exposure. We found that the major 4-1BB-expressing population was CD3+ T cells, although a moderate number of CD14+ cells and a few NKB1+ cells also expressed 4-1BB. The levels of 4-1BB expression induced by anticancer drugs, were relatively lower than that induced by CD3 ligation. Interestingly, at subcytotoxic concentrations, doxorubicin and bleomycin considerably enhanced 4-1BB expression induced by CD3 ligation in CEM cells. The ligation of the damage-induced 4-1BB by monoclonal antibody enhanced the viability and proliferating capacity of the cells. In conclusion, the expression of 4-1BB might be one of the cellular responses of the immune cells against various genotoxic stresses. 相似文献
42.
Effect of ketamine on apoptosis by energy deprivation in astroglioma cells using flow cytometry system 总被引:3,自引:0,他引:3
Apoptosis is a programmed, physiologic mode of cell death that plays an important role in tissue homeostasis. As for the central nervous system, ischemic insults can induce pathophysiologic cascade of apoptosis in neurophils. Impairment of astrocyte functions during brain ischemia can critically influence neuron survival by neuronglia interactions. We aimed to elucidate the protective effect of ketamine on apoptosis by energy deprivation in astrocytes. Ischemic insults was induced with iodoacetate/ carbonylcyanide m-chlorophenylhydrazone (IAA/CCCP) 1.5 mM/20 microm or 150 microm/2 microm for 1 hr in the HTB-15 and CRL-1690 astrocytoma cells. Then these cells were reperfused with normal media or ketamine (0.1 mM) containing media for 1 hr or 24 hr. FITC-annexin-V staining and propidium iodide binding were determined by using flow cytometry. Cell size and granularity were measured by forward and side light scattering properties of flow cytometry system, respectively. An addition of ketamine during reperfusion increased the proportion of viable cells. Ketamine alleviated cell shrinkage and increased granularity during the early period, and ameliorated cell swelling during the late reperfusion period. Ketamine may have a valuable effect on amelioration of early and late apoptosis in the astrocytoma cells, even though the exact mechanism remains to be verified. 相似文献
43.
We report two cases of lichen planus pigmentosus (LPP) that developed in a unilateral linear pattern. The patients presented with unilateral linear brown macules on the extremities. Skin biopsy showed orthokeratosis, basal hydropic degeneration with scarce lymphohistiocytic infiltrates, and numerous melanophages in both patients. These patients, to the best of our knowledge, are the first cases of LPP presenting with a linear pattern. LPP should be considered in the differential diagnosis of linear hyperpigmented skin lesions. 相似文献
44.
The progressive myoclonus epilepsy of the Lafora type (LD; MIM 254780) is a rare autosomal recessive disorder characterized by epilepsy, myoclonus, progressive neurological deterioration, and the presence of periodic acid-Schiff-positive polyglucosan inclusions (Lafora bodies). Mutations in the EPM2A gene have recently been found to cause LD and about 30 or more mutations have been reported thus far. LD is relatively common in countries of the Mediterranean Basin, the Middle East, India, and Pakistan. Although a few sporadic cases with the typical LD phenotype have also been reported in the Far East including Korea and Japan, a recent effort to find mutations in Japanese LD families was not successful. In the present study, we report two novel mutations in a Korean girl with LD; a 1-bp insertion mutation (c.223insC; G75fsX107) in exon 1 and a missense mutation (c.559A>G; T187A) in exon 3 of the EPM2A gene. To our knowledge, this is the first report of a genetically confirmed case of LD in Koreans and also in the Far East. 相似文献
45.
Gye Won Kim Sung Youl Hong Soon Cheon Shin Sung Hee Lee Won Bae Kim 《Archives of pharmacal research》1987,10(1):18-24
Mouse monoclonal antibodies to Hepatitis B surface antigen(HBsAg) were prepared and their functional capabilities tested by the method of solid phase enzyme linked immuno sorbent assay(ELISA). HBsAg binding studies indicated that one monoclonal antibody 6E-1-1 bound more HBsAg at a faster rate than the other monoclonal antibodies. Also, for the binding inhibition studies with the selected monoclonal antibody 6E-1-1, one monoclonal antibody 8D-3-6 didn’t exhibit binding inhibition for HBsAg. Then, a simultaneous ELISA method was developed for the immunodiagnosis of HBsAg. Different combinations of two monoclonal antibodies as solid phase and horseradish peroxidase(HRPO) labeled phase were studied. The combination of monoclonal antibody of higher affinity constant (6E-1-1) immobilized in a solid phase and monoclonal antibody of lower affinity constant (8D-3-6) as a HRPO labeled phase was more sensitive when two monoclonal antibodies of different affinity constants for HBsAg were prepared. 相似文献
46.
Gyeol Seong Seungbaek Lee Yang Won Min Yeon Sil Jang Hong Seog Kim Eui-Joong Kim So-Young Park Cheol-Hyun Kim Dong Kyung Chang 《Nutrients》2021,13(2)
Non-viable bacteria, referred to as “paraprobiotics,” have attracted attention as potentially safer alternatives to probiotics. The aim of this study was to investigate the efficacy of heat-killed Lactobacillus casei DKGF7 on the symptomatic improvement of irritable bowel syndrome (IBS) in a rat disease model and to elucidate the underlying mechanisms that contribute to the beneficial effects of heat-killed probiotics. Seven male Wistar rats were induced with IBS by restraint stress and administered heat-killed L. casei DKGF7 for four weeks and then compared with seven rats in the control group. Stool consistency measured four weeks after initial treatment was the primary outcome measure. To investigate the mechanism of action of the heat-killed bacteria on IBS, we measured serum corticosterone levels, inflammatory cytokines in colon tissue, and expression of tight junction proteins (TJPs) in the epithelium. The treatment group showed significantly better stool consistency scores than the control group at week 4, as well as at every measured time point (all p values < 0.05). The treatment group showed lower serum corticosterone levels, lower colonic inflammatory cytokine levels, and higher expression of TJPs compared with the control group. Paraprobiotics such as heat-killed L. casei DKGF7 can improve stool consistency in a rat IBS model, which may indicate a potential therapeutic strategy for IBS treatment. 相似文献
47.
Pyoeng Gyun Choe Chang Kyung Kang Hyeon Jeong Suh Jongtak Jung Kyoung-Ho Song Ji Hwan Bang Eu Suk Kim Hong Bin Kim Sang Won Park Nam Joong Kim Wan Beom Park Myoung-don Oh 《Emerging infectious diseases》2021,27(1):327
We investigated the kinetics of severe acute respiratory syndrome coronavirus 2 neutralizing antibodies in 7 asymptomatic persons and 11 patients with pneumonia. The geometric mean titer of neutralizing antibodies declined from 219.4 at 2 months to 143.7 at 5 months after infection, indicating a waning antibody response. 相似文献
48.
Young June Choe Eun Hwa Choi Jong Woon Choi Byung Wook Eun Lucy Youngmin Eun Yae-Jean Kim Yeo Hyang Kim Young A. Kim Yun-Kyung Kim Ji Hee Kwak Hyuk Min Lee Hyunju Lee Joon Kee Lee June Dong Park Eun-Jin Kim Young Joon Park Jin Gwack Sang Won Lee 《Emerging infectious diseases》2021,27(4):1196
A concerning development during the coronavirus disease pandemic has been multisystem inflammatory syndrome in children. Reports of this condition in East Asia have been limited. In South Korea, 3 cases were reported to the national surveillance system for multisystem inflammatory syndrome in children. All case-patients were hospitalized and survived with no major disease sequelae. 相似文献
49.
Kim Si Hyun Park Jae Joon Kim Ki Hong Yang Hee Jo Kim Doo Sang Lee Chang Ho Jeon Youn Soo Shim Sung Ryul Kim Jae Heon 《International urology and nephrology》2021,53(9):1733-1746
International Urology and Nephrology - Late onset hypogonadism (LOH) is an age-dependent reduction of testosterone associated with alterations of metabolic profile, including glucose control,... 相似文献
50.