全文获取类型
收费全文 | 1761篇 |
免费 | 51篇 |
国内免费 | 61篇 |
学科分类
医药卫生 | 1873篇 |
出版年
2025年 | 7篇 |
2024年 | 19篇 |
2023年 | 47篇 |
2022年 | 88篇 |
2021年 | 96篇 |
2020年 | 82篇 |
2019年 | 63篇 |
2018年 | 57篇 |
2017年 | 40篇 |
2016年 | 38篇 |
2015年 | 65篇 |
2014年 | 117篇 |
2013年 | 147篇 |
2012年 | 80篇 |
2011年 | 115篇 |
2010年 | 108篇 |
2009年 | 92篇 |
2008年 | 98篇 |
2007年 | 88篇 |
2006年 | 71篇 |
2005年 | 53篇 |
2004年 | 40篇 |
2003年 | 36篇 |
2002年 | 28篇 |
2001年 | 18篇 |
2000年 | 20篇 |
1999年 | 16篇 |
1998年 | 17篇 |
1997年 | 14篇 |
1995年 | 5篇 |
1994年 | 8篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 7篇 |
1986年 | 7篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 2篇 |
1982年 | 9篇 |
1981年 | 9篇 |
1980年 | 11篇 |
1979年 | 3篇 |
1978年 | 5篇 |
1977年 | 7篇 |
1976年 | 3篇 |
1971年 | 1篇 |
排序方式: 共有1873条查询结果,搜索用时 15 毫秒
1.
The mortality from ulcerative colitis in Denmark, calculated on the basis of the mortality statistics, was 0.5/100,000/year for the period 1960–69. The total material consists of 110 females and 108 males with ulcerative colitis. The mortality showed a decreasing tendency during the study period, but the fall was not significant. The distribution of the deaths between rural and urban areas corresponded to the distribution of the general population. 93 % of the deaths took place in hospital, the greater part in surgical departments. 相似文献
2.
《Modern rheumatology / the Japan Rheumatism Association》2013,23(4):331-332
AbstractLow-field extremity magnetic resonance imaging (lfMRI) is currently commercially available and has been used clinically to evaluate rheumatoid arthritis (RA). However, one disadvantage of this new modality is that the field of view (FOV) is too small to assess hand and wrist joints simultaneously. Thus, we have developed a new lfMRI system, compacTscan, with a FOV that is large enough to simultaneously assess the entire wrist to proximal interphalangeal joint area. In this work, we examined its clinical value compared to conventional 1.5 tesla (T) MRI. The comparison involved evaluating three RA patients by both 0.3 T compacTscan and 1.5 T MRI on the same day. Bone erosion, bone edema, and synovitis were estimated by our new compact MRI scoring system (cMRIS) and the κ coefficient was calculated on a joint-by-joint basis. We evaluated a total of 69 regions. Bone erosion was detected in 49 regions by compacTscan and in 48 regions by 1.5 T MRI, while the total erosion score was 77 for compacTscan and 76.5 for 1.5 T MRI. These findings point to excellent agreement between the two techniques (κ = 0.833). Bone edema was detected in 14 regions by compacTscan and in 19 by 1.5 T MRI, and the total edema score was 36.25 by compacTscan and 47.5 by 1.5 T MRI. Pseudo-negative findings were noted in 5 regions. However, there was still good agreement between the techniques (κ = 0.640). Total number of evaluated joints was 33. Synovitis was detected in 13 joints by compacTscan and 14 joints by 1.5 T MRI, while the total synovitis score was 30 by compacTscan and 32 by 1.5 T MRI. Thus, although 1 pseudo-positive and 2 pseudo-negative findings resulted from the joint evaluations, there was again excellent agreement between the techniques (κ = 0.827). Overall, the data obtained by our compacTscan system showed high agreement with those obtained by conventional 1.5 T MRI with regard to diagnosis and the scoring of bone erosion, edema, and synovitis. We conclude that compacTscan is useful for diagnosis and estimation of disease activity in patients with RA. 相似文献
3.
Background
Ischemic colitis is a common disorder often without clear indications for surgical management. The aim of this study was to identify risk factors that predict the need for surgery.Methods
Patients were identified retrospectively based on International Classification of Disease codes and admission over an 8-year period.Results
A total of 253 patients presented with ischemic colitis. A total of 205 patients were managed nonsurgically, 12 underwent immediate surgery (within 12 hours of presentation), and 36 had delayed surgery. On univariate analysis, risk factors that predicted delayed surgery were peripheral vascular disease, atrial fibrillation, hypotension, tachycardia, absence of bleeding per rectum, free intraperitoneal fluid on computed tomography scan, intensive care unit admission, vasopressors, mechanical ventilation, and increased lactate level on admission. Intraperitoneal fluid on computed tomography scan and absence of bleeding per rectum were predictive of surgical intervention on multivariate analysis.Conclusions
In patients with ischemic colitis, several risk factors were associated with the need for subsequent surgery during the same admission. These factors could be used to select patients for immediate surgery before worsening of their clinical condition. 相似文献4.
杨延峰 《浙江中医药大学学报》2007,31(1):76-77
[目的]探讨姜连清肠煎在治疗慢性溃疡性结肠炎中的疗效。[方法]采用姜连清肠煎对42例慢性溃疡性结肠炎患者进行临床观察。[结果]治愈16例,好转24例,无效2例,总有效率95.2%。[结论]本病多病程长,本虚标实多见。姜连清肠煎采取标本同治,故有较好疗效。 相似文献
5.
血清C反应蛋白和D-二聚体联合检测在溃疡性结肠炎病情活动性判断中的价值 总被引:1,自引:0,他引:1
目的通过检测溃疡性结肠炎(UC)患者的血清C反应蛋白(CRP)及D-二聚体水平,探讨二者在UC患者病情活动及严重程度判断中的应用价值。方法分别采用胶乳增强免疫比浊法与免疫扩散比浊法检测64例活动期UC患者、45例缓解期UC患者及40例健康对照者血清CRP及D-二聚体水平,并对活动期患者行肠镜及病理组织学检查,评价病情程度。结果(1)活动期UC组患者血清CRP及D-二聚体水平与缓解期UC组及对照组比较,差异均有统计学意义(P<0.01);缓解期UC组CRP水平与对照组比较,差异有统计学意义(P<0.05),而D-二聚体水平与对照组比较,差异无统计学意义(P>0.05)。(2)重型UC患者血清CPR及D-二聚体水平与轻、中型患者比较,差异有统计学意义(P<0.05)。结论血清CRP及D-二聚体水平可作为评价UC患者病情活动性及严重程度的良好指标。 相似文献
6.
目的 探讨亚甲基四氢叶酸还原酶(MTHFR)基因C677T和A1298C位点多态性与浙江汉族人群溃疡性结肠炎(UC)的关系.方法 采用限制性片段长度多态性PCR(PCR-RELP)法,在274例UC患者和726例正常对照者中检测MTHFR C677T及A1298C基因多态性分布差异.结果 UC患者中,MTHFR C677T突变等位基因(T)和基因型(CT+TT)频率与正常对照组相比差异无统计学意义(P>0.05);而MTHFR A1298C突变等位基因(C)和基因型(AC+CC)频率均高于正常对照组(35.77%比29.96%,P=0.013;52.19%比44.90%,P=0.039).另外,MTHFR 677纯合子突变基因型(TT)、突变等位基因(T)以及677CT/1298AC复合基因型频率在广泛性结肠炎患者中明显高于远端结肠炎(37.66%比14.72%,P=0.0002;49.35%比32.99%,P=0.0004;29.87%比15.23%,P=0.006);重度UC患者的MTHFR 1298位点突变等位基因(C)频率显著低于(轻+中)度患者(18.97%比33.88%,P=0.022).结论 MTHFR C677T及A1298C基因多态性与浙江汉族UC明显相关.Abstract: Objective To investigate the association between the genetic polymorphisms of methylenetetrahydrofolate reductase (MTHFR) and ulcerative colitis (UC) of Han ethnic population in Zhejiang, China. Methods Two hundred and seventy-four consecutive patients with UC and 726 healthy controls (HC) were studied. The genetic polymorphisms of MTHFR (C677T and A1298C) were genotyped using PCR-RELP methods. Results The frequencies of variant allele and genotype in MTHFR A1298Cgene were higher in UC patients than in the HC (35.77% vs 29. 96%, P =0. 013; 52. 19% vs 44. 90%,P=0.039; respectively). However, there were no significant discrepancies of the allele and genotype frequencies in the MTHFR C677T gene between the UC patients and the HC (P > 0. 05 ). In addition, the MTHFR 677Tr homozygote, T allele and 677CT/1298AC compound genotype were more prevalent in patients with extensive colitis than in those with distal colitis (37. 66% vs 14. 72% ,P = 0. 0002; 49. 35% vs 32.99% ,P =0. 0004; 29. 87% vs 15.23% ,P =0. 006; respectively). Furthermore,the variant allele in the MTHFR A1298C gene (C) in severe UC patients was significantly lower than in mild and moderate UC patients (18.97% vs 33. 88% ,P =0. 022). Conclusion The genetic polymorphisms of MTHFR C677T and A1298C are obviously associated with Han ethnic population with UC in Zhejiang province. 相似文献
7.
P. Vento T. Kiviluoto H. J. Järvinen S. Soinila 《Scandinavian journal of gastroenterology》2013,48(2):180-189
Background: Nitric oxide (NO) has an important role both in normal physiology and pathological events of the colon. Our aim was to study possible changes of the three nitric oxide synthases in ulcerative colitis (UC). Methods: Tissue samples from normal colon and least and moderately affected regions of ulcerative colitis colon were obtained at surgery and immunostained for NOS-1, NOS-2, NOS-3, and GAP-43, a marker of nerve fibers. Quantitative analysis of NOS-1 immunoreactivity was performed on the circular muscle layer. Results: NOS-1-immunoreactive fibers in the muscularis mucosae disappeared in least affected and moderately affected UC colon. Quantitative analysis of NOS-1-immunoreactive nerve fibers in the circular muscle showed no differences between normal and diseased colon. NOS-2 immunoreactivity appeared apically in the epithelial cells. In normal colon some specimens showed immunoreactivity in lower parts of crypts. NOS-2 immunoreactivity increased according to the severity of UC. NOS-3 immunoreactivity was exclusively localized in the vascular endothelium. The difference in NOS-3 staining intensity between the lamina propria and submucosa observed in normal tissue disappeared in moderately affected UC colon. The number of NOS-3-immunoreactive vascular profiles increased in the lamina propria of UC colon. Conclusions: All three NOS isoforms show specific changes in UC colon. 相似文献
8.
R. Holma P. Salmenperä J. Lohi H. Vapaatalo R. Korpela 《Scandinavian journal of gastroenterology》2013,48(6):630-635
Background: Certain lactobacilli reduce the severity of experimental colitis. The aim of this study was to compare the effects of a human strain Lactobacillus rhamnosus GG and a rat strain Lactobacillus reuteri R2LC on acetic acid-induced colitis in rats. Methods:Lactobacillus rhamnosus GG, Lactobacillus reuteri R2LC or sulphasalazine were given orally to the rats. Colitis was assessed 72 h after induction with acetic acid. Results:Lactobacillus reuteri R2LC significantly antagonized body weight loss caused by inflammation compared with Lactobacillus rhamnosus GG and sulphasalazine, and oedema formation in the colon compared with sulphasalazine. Lactobacillus reuteri R2LC reduced the median value of macroscopic ulceration and the protein content of inducible nitric oxide synthase by 50% and the median of the protein content of inducible cyclooxygenase by 30% compared with that of the colitis control group, and Lactobacillus rhamnosus GG reduced the median of inducible nitric oxide protein content by 40% and increased the median of inducible cyclooxygenase protein content by 30% compared with the median value of the colitis control group, but these differences were not statistically significant. Conclusions: The rat strain Lactobacillus reuteri R2LC, but not the human strain Lactobacillus rhamnosus GG, is of benefit in reducing the severity of acetic acid-induced colitis in rats. These results suggest that it is not the total amount of Lactobacillus but the particular species or strain of Lactobacillus that is important in attenuating experimental colitis. 相似文献
9.
R. Holma P. Juvonen M. Z. Asmawi H. Vapaatalo R. Korpela 《Scandinavian journal of gastroenterology》2013,48(9):1042-1047
Background: Galacto-oligosaccharides potentially attenuate colonic inflammation by two mechanisms: through beneficial effects on intestinal microflora and by increasing the colonic short-chain fatty acid concentration. The purpose of this study was to investigate the effects of galacto-oligosaccharides on the development of inflammation and on the growth of bifidobacteria in trinitrobenzene sulphonic acid (TNBS)-induced colitis, a model that has been shown to benefit from short-chain fatty acid administration and to be associated with alterations in the colonic microflora. Methods: Rats were given daily either whey-derived or lactose-derived galacto-oligosaccharides (4 g kg -1 day -1 , p.o.), starting 10 days before colitis induction, or dexamethasone (2 mg kg -1 day -1 , s.c., a positive control), starting at colitis induction. Colon wet weight, macroscopic damage and myeloperoxidase activity were assessed 72 h after the induction of colitis. Faecal bifidobacteria were counted at the beginning of the study, and immediately before and 72 h after colitis induction. Results: Galacto-oligosaccharides increased the colonic levels of bifidobacteria but also the levels of other bacterial species. Neither whey-derived nor lactose-derived galacto-oligosaccharides reduced the severity of inflammation. Conclusions: Galacto-oligosaccharides are able to modify gut microflora in severe TNBS-induced colitis, but unable to attenuate the inflammation. 相似文献
10.
Nermina Jahovic Nursal Gedik Feriha Ercan Serap şirvanci Meral Yüksel Göksel şener 《Scandinavian journal of gastroenterology》2013,48(8):954-962
Objective. The results of previous studies suggest that statins have a direct anti-inflammatory effect that is not directly related to their cholesterol-lowering activity. The aim of this study was to investigate the effect of simvastatin (SIM) and fluvastatin (FLU) on trinitrobenzene sulfonic acid (TNBS)-induced colonic inflammation in rats. Material and methods. The drugs were given for 3 days (0.1 and 1 mg/kg day?1; intraperitoneally) after induction of colitis. The lesions in the distal colon were scored at the macroscopic and microscopic level. Tissue malondialdehyde (MDA) and glutathione (GSH) levels, myeloperoxidase (MPO) activity and collagen content were assessed and formation of reactive oxygen species and peroxynitrite was monitored by chemiluminescence (CL) assay. Trunk blood was collected for the measurement of serum tumor necrosis factor (TNF)-α level. Results.Treatment with SIM reduced the lesion score of the colitis group at macroscopic level (p<0.05), but there was no effect of treatment with FLU. The increase in colonic MDA level of the colitis group was reduced by both drugs at all doses (p<0.05–0.001). The decrease in GSH and the an increase in MPO activity in the colitis group were reversed by SIM at all doses (p<0.01), but FLU had no effect. An increase in colonic lucigenin CL value in the colitis group was reduced by SIM and FLU at all doses (p<0.001) and an increase in peroxynitrite ratio in the colitis group showed a significant reduction in SIM-treated groups; FLU reduced this effect at a dose of 1 mg/kg (p<0.01). An increase in tissue collagen content and serum TNF-α level in the colitis group was reversed by both drugs at all doses (p<0.001). Conclusions. SIM and FLU seemed to be beneficial in a TNBS-induced rat colitis model through the prevention of lipid peroxidation, superoxide generation, cytokine production and neutrophil accumulation. 相似文献