全文获取类型
收费全文 | 4054篇 |
免费 | 193篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 53篇 |
妇产科学 | 58篇 |
基础医学 | 452篇 |
口腔科学 | 132篇 |
临床医学 | 243篇 |
内科学 | 1001篇 |
皮肤病学 | 145篇 |
神经病学 | 337篇 |
特种医学 | 210篇 |
外科学 | 546篇 |
综合类 | 13篇 |
一般理论 | 1篇 |
预防医学 | 248篇 |
眼科学 | 130篇 |
药学 | 279篇 |
中国医学 | 15篇 |
肿瘤学 | 394篇 |
出版年
2023年 | 34篇 |
2022年 | 49篇 |
2021年 | 110篇 |
2020年 | 61篇 |
2019年 | 83篇 |
2018年 | 105篇 |
2017年 | 61篇 |
2016年 | 90篇 |
2015年 | 66篇 |
2014年 | 127篇 |
2013年 | 152篇 |
2012年 | 214篇 |
2011年 | 285篇 |
2010年 | 151篇 |
2009年 | 140篇 |
2008年 | 186篇 |
2007年 | 185篇 |
2006年 | 215篇 |
2005年 | 214篇 |
2004年 | 201篇 |
2003年 | 184篇 |
2002年 | 153篇 |
2001年 | 118篇 |
2000年 | 109篇 |
1999年 | 108篇 |
1998年 | 36篇 |
1997年 | 31篇 |
1996年 | 37篇 |
1995年 | 23篇 |
1994年 | 25篇 |
1993年 | 22篇 |
1992年 | 58篇 |
1991年 | 53篇 |
1990年 | 52篇 |
1989年 | 62篇 |
1988年 | 62篇 |
1987年 | 47篇 |
1986年 | 44篇 |
1985年 | 50篇 |
1984年 | 39篇 |
1983年 | 29篇 |
1982年 | 16篇 |
1979年 | 27篇 |
1978年 | 16篇 |
1977年 | 22篇 |
1976年 | 8篇 |
1975年 | 12篇 |
1974年 | 17篇 |
1973年 | 10篇 |
1969年 | 12篇 |
排序方式: 共有4268条查询结果,搜索用时 0 毫秒
41.
42.
PURPOSE: To investigate optical coherence tomography images of spontaneous macular hole closure. METHOD: Case report. In a 60-year-old woman with full-thickness macular hole, posterior vitreous detachment, and previous branch retinal vein occlusion, we observed the entire course of spontaneous macular hole closure by use of optical coherence tomography. RESULTS: Spontaneous macular hole closure began as the inward protrusion of the tissue around the margin of the macular hole. The protruding tissue then connected to bridge the macular hole, which mimicked a foveal retinal detachment. The bridged tissue gradually thickened, and the foveal detachment and perifoveal cysts resolved. The fovea eventually regained its normal configuration. CONCLUSIONS: The bridging of the protruding retinal tissue over the macular hole plays a key role in spontaneous macular hole closure. 相似文献
43.
E5531, a synthetic non-toxic lipid A derivative blocks the immunobiological activities of lipopolysaccharide. 总被引:6,自引:0,他引:6
T Kawata J R Bristol D P Rossignol J R Rose S Kobayashi H Yokohama A Ishibashi W J Christ K Katayama I Yamatsu Y Kishi 《British journal of pharmacology》1999,127(4):853-862
1. The major pathological responses to Gram-negative bacterial sepsis are triggered by endotoxin or lipopolysaccharide. As endotoxin is shed from the bacterial outer membrane, it induces immunological responses that lead to release of a variety of cytokines and other cellular mediators. As part of a program aimed at developing a therapeutic agent for septic shock, we have developed E5531, a novel synthetic lipopolysaccharide antagonist. 2. As measured by release by tumour necrosis factor-alpha, human monocytes or whole blood can be activated by lipopolysaccharide, lipid A, and lipoteichoic acid (from Gram-positive bacteria). E5531 potently antagonizes activation by all these agents while itself being devoid of agonistic activity. 3. The inhibitory activity of E5531 was dependent on time of addition. When 10 nM E5531 was added simultaneously with lipopolysaccharide or 1 - 3 h before addition of lipopolysaccharide, production of tumour necrosis factor-alpha was inhibited by more than 98%. The addition of E5531 1 h after lipopolysaccharide reduced the efficacy of E5531 by 47%. 4. Antagonistic activity of E5531 was specific for lipopolysaccharide as it was ineffective at inhibiting interferon-gamma mediated NO release of RAW 264.7 cells, phorbor 12-myristate 13-acetate stimulated superoxide anion production in human neutrophils, concanavalin A stimulated mitogenic activity in murine thymocytes and tumor necrosis factor-alpha induced E-selectin expression in human umbilical vein endothelial cells. 5. E5531 as well as MY4, an anti-CD14 antibody, inhibited radiolabelled lipopolysaccharide binding in human monocytes. 6. These results support our contention that E5531 is a potent antagonist of lipopolysaccharide-induced release of tumour necrosis factor-alpha and other cellular mediators and may be an effective therapeutic agent for human septic shock due to Gram-negative bacteria. 相似文献
44.
Kohno J Asai Y Nishio M Sakurai M Kawano K Hiramatsu H Kameda N Kishi N Okuda T Komatsubara S 《The Journal of antibiotics》1999,52(12):1114-1123
Four new antibiotics, TMC-171A (2), B (3), C (4) and TMC-154 (5) have been isolated from the fermentation of fungal strains Gliocladium sp. TC 1304 and TC 1282, respectively. Spectroscopic and degradation studies have shown that TMC-171s and TMC-154 were new members of the TMC-151 class of antibiotics, unique polyketides modified with a D-mannose and a D-mannitol or a D-arabitol. These compounds showed moderate cytotoxicity to various tumor cell lines. 相似文献
45.
S Fushiya Y Kishi K Hattori J Batkhuu F Takano A N Singab T Okuyama 《Planta medica》1999,65(5):404-407
The effect of an Egyptian medicinal plant, Cleome droserifolia (Forssk.) Del. on nitric oxide (NO) production in bacillus Calmette-Guérin-induced mouse peritoneal macrophages activated by lipopolysaccharide was investigated in vitro. The methanol extract of C. droserifolia reduced the NO production, and two flavonoids were isolated as the active components. The new one was determined to be 5,4'-dihydroxy-6,7,8,3',5'-pentamethoxyflavone (1) and the other was identified as 5,4'-dihydroxy-6,7,8,3'-tetramethoxyflavone (8-methoxycirsilineol; 2). Compound 1 concentration-dependently suppressed the NO production and was effective at a non-toxic concentration (12.5 micrograms/ml). The suppressive activity of 2 was weaker than that of 1. 相似文献
46.
Kishi HS 《Neurosurgery》2000,47(2):441-5; discussion 445-6
This article recountsOFF (Shimada) Kishi's experience when he was appointed as chief of the First Investigation Committee that evaluated the damage caused by the atom bomb dropped on Hiroshima. 相似文献
47.
Reduced MLH1 expression after chemotherapy is an indicator for poor prognosis in esophageal cancers.
Kentaro Kishi Yuichiro Doki Masahiko Yano Takushi Yasuda Yoshiyuki Fujiwara Syuji Takiguchi Sontae Kim Ichiro Higuchi Morito Monden 《Clinical cancer research》2003,9(12):4368-4375
PURPOSE: Loss of function or expression of the mismatch repair gene MLH1 has been implicated in experimentally acquired resistance to cisplatin (CDDP) and other anticancer agents. The clinical significance of MLH1 expression was evaluated in advanced thoracic squamous cell carcinoma of the esophagus (ESCC) treated by neoadjuvant chemotherapy. EXPERIMENTAL DESIGN: We investigated MLH1 and P53 expression by immunohistochemistry in the surgical specimens of 107 patients who had undergone preoperative chemotherapy using CDDP along with 5-FU and ADM. These findings were correlated with the clinical outcome for this treatment. Biopsy samples before chemotherapy in 20 of these patients, and another 43 surgical specimens without chemotherapy, were also examined as control samples. RESULTS: In surgical specimens of ESCC, low MLH1 expression was not frequent without chemotherapy, whereas it was commonly observed after chemotherapy (14 versus 37%, P = 0.0057). Comparison between samples before and after chemotherapy revealed that MLH1 expression was unchanged during chemotherapy in 12 of 20 patients (60%) but was from high to low in 8 of 20 patients (40%). In the surgical specimen after neoadjuvant chemotherapy, MLH1 expression was not correlated with any clinicopathological factors, including the response to chemotherapy. However, low MLH1 showed poorer prognosis than high MLH1 (5-year survival 40.6 versus 19.3%, P = 0.0393), and in multivariate analysis, MLH1 was an independent prognostic factor for this multimodal treatment, following lymph node metastasis and clinical response to chemotherapy. Positive p53 expression, which was not affected by chemotherapy, was weakly associated with a poor response and clinical outcome, although this trend was not significant. CONCLUSIONS: In advanced ESCC, expression of MLH1 is reduced during CDDP-based chemotherapy, and this may partly account for poor postoperative survival. 相似文献
48.
Identification of HRK as a target of epigenetic inactivation in colorectal and gastric cancer. 总被引:3,自引:0,他引:3
49.
To clarify the nature of serous retinal detachment in Vogt-Koyanagi-Harada (VKH) syndrome, 42 consecutive eyes of 21 patients with acute phase VKH syndrome were examined using optical coherence tomography (OCT). OCT revealed two patterns of serous retinal detachment. Twenty-nine eyes (69%) had a true retinal detachment, 17 eyes (40%) had intraretinal fluid accumulation in the outer retina, and 4 eyes had both. Intraretinal fluid accumulation appeared as an oval space in the outer retina. On fluorescein angiography, the eyes with intraretinal fluid accumulation showed more severe dye leakage from the retinal pigment epithelium. 相似文献
50.
Kishi Y Nickander KK Schmelzer JD Low PA 《Journal of the peripheral nervous system : JPNS》2000,5(1):11-18
Chronic hyperglycemia results in a large deficit in nerve blood flow. Both autoxidative- and ischemia-induced lipid peroxidation occurs, with resultant peripheral sensory neuropathy in streptozotocin-induced diabetes in the rat. Free radical defenses, especially involving antioxidant enzymes, have been suggested to be reduced, but scant information is available on chronic hyperglycemia. We evaluated the gene expression of glutathione peroxidase, catalase, and superoxide dismutase (cuprozinc and manganese separately) in L4,5 dorsal root ganglion (DRG) and superior cervical ganglion, as well as enzyme activity of glutathione peroxidase in DRG and sciatic nerve in experimental diabetic neuropathy of 3 months and 12 months durations. We also evaluated nerve electrophysiology of caudal, sciatic-tibial, and digital nerves. A nerve conduction deficit was seen in all nerves in experimental diabetic neuropathy at both 3 and 12 months. Gene expression of glutathione peroxidase, catalase, cuprozinc superoxide dismutase, and manganese superoxide dismutase were not reduced in experimental diabetic neuropathy at either 3 or 12 months. Catalase mRNA was significantly increased in experimental diabetic neuropathy at 12 months. Glutathione peroxidase enzyme activity was normal in sciatic nerve. We conclude that gene expression is not reduced in peripheral nerve tissues in very chronic experimental diabetic neuropathy. Changes in enzyme activity may be related to duration of diabetes or due to post-translational modifications. 相似文献