全文获取类型
收费全文 | 721篇 |
免费 | 82篇 |
国内免费 | 8篇 |
专业分类
儿科学 | 14篇 |
妇产科学 | 3篇 |
基础医学 | 56篇 |
口腔科学 | 3篇 |
临床医学 | 109篇 |
内科学 | 318篇 |
皮肤病学 | 6篇 |
神经病学 | 13篇 |
特种医学 | 37篇 |
外科学 | 51篇 |
综合类 | 3篇 |
预防医学 | 68篇 |
眼科学 | 4篇 |
药学 | 99篇 |
肿瘤学 | 27篇 |
出版年
2022年 | 4篇 |
2021年 | 5篇 |
2020年 | 5篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 13篇 |
2014年 | 7篇 |
2013年 | 17篇 |
2012年 | 20篇 |
2011年 | 8篇 |
2010年 | 15篇 |
2009年 | 6篇 |
2008年 | 26篇 |
2007年 | 23篇 |
2006年 | 17篇 |
2005年 | 20篇 |
2004年 | 21篇 |
2003年 | 32篇 |
2002年 | 39篇 |
2001年 | 34篇 |
2000年 | 36篇 |
1999年 | 40篇 |
1998年 | 24篇 |
1997年 | 15篇 |
1996年 | 19篇 |
1995年 | 11篇 |
1994年 | 14篇 |
1993年 | 8篇 |
1992年 | 22篇 |
1991年 | 20篇 |
1990年 | 29篇 |
1989年 | 33篇 |
1988年 | 33篇 |
1987年 | 35篇 |
1986年 | 31篇 |
1985年 | 15篇 |
1984年 | 15篇 |
1983年 | 11篇 |
1982年 | 6篇 |
1981年 | 11篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 9篇 |
1976年 | 5篇 |
1974年 | 3篇 |
1973年 | 4篇 |
1972年 | 6篇 |
1971年 | 4篇 |
1968年 | 6篇 |
排序方式: 共有811条查询结果,搜索用时 0 毫秒
81.
本文对胃食管反流病(GERD)和Barrett食管(BE)的某些方面进行了总结,可能对临床医师有一定帮助。 相似文献
82.
目的 探讨相对健康的中老年人血中糖化血红蛋白(HbAlc)含量对颈动脉硬化的影响.方法 从广州生物库队列中单纯随机抽样收集1863名年龄≥50岁的广州市居民的个人资料,问卷调查其病史、体格检查及测定血清空腹血糖、血脂、HbA1c的含量并应用彩色多普勒超声测量颈总动脉内膜-中层厚度(intima media thickness,IMT).在调整相关混染因素后,应用协方差分析进行连续变量分析.结果 (1)在调整年龄、性别和空腹血糖等因素后,平均颈总动脉IMT随HbA1c含量升高呈明显增加趋势(P=0.005).线性回归模型显示,在调整年龄、性别、吸烟状态、腰围、收缩压和舒张压、甘油三酯、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇和空腹血糖等潜在危险因素后,结果仍然显示HbA1c水平与平均颈总动脉IMT有明显的线性相关(回归系数为0.014,P=0.03);(2)经过调整多种潜在混杂因素后,与HbA1c理想组(HbA1c<6.5%)比较,良好组(HbA1c为6.5%~7.5%)和差组(HbA1c>7.5%)发生颈动脉硬化的比值比(95%置信区间)分别为1.62(1.10,2.38)和1.76(0.86,3.63),趋势检验(P=0.01).结论 相对健康的中老年人HbA1c含量升高是颈动脉硬化的独立危险因素之一,提示降低HbA1c水平对阻止或延缓颈动脉硬化的发生与发展有重要意义. 相似文献
83.
Sucralfate versus cimetidine in reflux esophagitis. A single-blind multicenter study 总被引:1,自引:0,他引:1
W Hameeteman D M v d Boomgaard W Dekker M Schrijver I C Wesdorp G N Tytgat 《Journal of clinical gastroenterology》1987,9(4):390-394
A single-blind randomized multicenter study was performed in 42 patients with endoscopically documented reflux esophagitis. Patients were randomly given 400 mg cimetidine q.i.d. or a suspension of 1 g sucralfate q.i.d. for a period of 8 weeks. Forty patients were evaluated after 8 weeks. Symptomatic improvement was good and was comparable in both groups. We saw side-effects in only three patients, two on sucralfate and one on cimetidine, and these did not necessitate withdrawal from the study. Endoscopy showed improvement of esophagitis in 53% and healing in 31% of patients after sucralfate treatment. With cimetidine, improvement was seen in 67% and healing in 14%. One patient on cimetidine developed a stricture during treatment. We conclude that treatment with sucralfate improves symptoms and lessens severity of reflux esophagitis and that the results with sucralfate appear to be comparable to those obtained with cimetidine. Sucralfate is a valid alternative to H2-receptor antagonist therapy. 相似文献
84.
Relation between vacA subtypes, cytotoxin activity, and disease in Helicobacter pylori-infected patients from the netherlands 总被引:4,自引:0,他引:4
Zhi-Jun Pan M.D. René W.M. van der Hulst M.D. Ph.D. Guido N.J. Tytgat M.D. Ph.D. Jacob Dankert M.D. Ph.D. Arie van der Ende Ph.D. 《The American journal of gastroenterology》1999,94(6):1517-1521
OBJECTIVE: The vacuolating cytotoxin of Helicobacter pylori (H. pylori) is encoded by vacA, of which allelic variation has been described. In the U.S., H. pylori strains with the signal sequence allele s1a are associated with enhanced gastric inflammation and with peptic ulcer disease (PUD). The m1 middle region allele is linked with more severe gastric epithelial damage. However, the distribution of H. pylori genotypes and the association with disease may be different in other geographical areas. The aim of this study was to establish whether vacA types among H. pylori isolates from Dutch patients are associated with disease. METHODS: The cytotoxin activity of the H. pylori isolates from 34 PUD patients and 46 patients with functional dyspepsia (FD) was assessed by an in vitro assay using HeLa cells as indicator cells. The vacA types and cagA status of the isolates were assessed by polymerase chain reaction (PCR). RESULTS: vacA s1-type H. pylori displayed cytotoxin activity more frequently than s2 vacA-type H. pylori (p = 0.003). This difference was not significant when only cagA+ H. pylori were considered. H. pylori isolates with the m1 vacA type exhibited a higher cytotoxin activity, independent of cagA (p = 0.006). Ninety-four percent (32/34) of the PUD patients and 74% (34/46) of the FD patients were infected with s1 vacA-type H. pylori (p = 0.04). When only cagA+ H. pylori were considered, s1 vacA type was not associated with disease. In addition, neither the s1a nor s1b subtypes correlated with disease. CONCLUSIONS: An association between vacA subtypes and disease could not be established in this patient population, due to the strong linkage between vacA s1 type and cagA. 相似文献
85.
Paul Fockens MD Carin G. Manshanden MD J.Jan B. van Lanschot MD Hugo Obertop MD Guido N.J. Tytgat MD 《Gastrointestinal endoscopy》1997,46(6):487-491
Background: Half of the patients who undergo surgery for cancer of the esophagus or gastric cardia present with recurrent disease within 2 years after the operation. We investigated the value of endosonography for the early detection of recurrent disease. Methods: Forty-three patients entered a follow-up protocol in which endosonography was performed every 6 months within the first 2 years after resection. Results: During 16 of a total of 66 examinations, suspicious abnormalities were found. In three patients free fluid was seen, but recurrence could not be confirmed during follow-up. In eight patients suspicious lymph nodes were seen; six died within 6 months, one was alive with a proven recurrence at 6 months, and one was alive without recurrence at 22 months. In five patients focal wall-thickening or a mass was seen; three died within 6 months, and two were alive with a proven recurrence at 2 and 5 months. After exclusion of free fluid, the positive predictive value of abnormalities on endoscopic ultrasonography (EUS) was 92%. Conclusions: Endosonography, performed at 6-month intervals after resection of cancer of the esophagus or gastric cardia, is accurate in the early detection of locoregional recurrent disease. Two thirds of the patients were still without symptoms when the recurrence was found. (Gastrointest Endosc 1997;46:487-91.) 相似文献
86.
87.
Five genetic markers in the interleukin 1 family in relation to
inflammatory bowel disease 总被引:10,自引:1,他引:10 下载免费PDF全文
Background—An imbalance between theproinflammatory cytokine interleukin 1β (IL-1β) and theanti-inflammatory cytokine IL-1 receptor antagonist (IL-1ra) has beenpostulated as a pathogenic factor in inflammatory bowel disease (IBD).
Aims—To study allelic frequenciesof novel polymorphisms in the genes for IL-1β and IL-1ra in patientswith IBD and to assess the relation between ex vivo cytokine productionand allelic variants of the IL-1β and IL-1ra genes.
Subjects—Two hundred and seventyhealthy controls, 74 patients with ulcerative colitis (UC), 72 withCrohn's disease (CD), 40 with primary sclerosing cholangitis for theallelic frequencies, and 60 healthy individuals for the ex vivostimulation test.
Methods—Genotyping was performed bypolymerase chain reaction and subsequent cleavage with specificendonucleases (Mwo1, MspAI1, Alu1, Taq1, BsoF1) for five novelrestriction fragment length polymorphisms (RFLPs) in the genes forIL-1ra and IL-1β.
Results—No significant differences were found inthe allelic frequencies or allele carriage rates of the markers in theIL-1β and IL-1ra genes between CD, UC, and healthy controls. Noassociation between the genetic markers and cytokine production levelswas observed. Patients with UC carried the combination of both the infrequent allele of the Taq1 RFLP and the Mwo1 RFLP significantly morefrequently (35.2% in UC versus 71.1% in controls).
Conclusions—UC is associatedwith carriage of both infrequent alleles of the Taq1 and Mwo1 RFLPs.However, it could not be confirmed whether the association reflects apathogenic mechanism underlying UC.
相似文献
Aims—To study allelic frequenciesof novel polymorphisms in the genes for IL-1β and IL-1ra in patientswith IBD and to assess the relation between ex vivo cytokine productionand allelic variants of the IL-1β and IL-1ra genes.
Subjects—Two hundred and seventyhealthy controls, 74 patients with ulcerative colitis (UC), 72 withCrohn's disease (CD), 40 with primary sclerosing cholangitis for theallelic frequencies, and 60 healthy individuals for the ex vivostimulation test.
Methods—Genotyping was performed bypolymerase chain reaction and subsequent cleavage with specificendonucleases (Mwo1, MspAI1, Alu1, Taq1, BsoF1) for five novelrestriction fragment length polymorphisms (RFLPs) in the genes forIL-1ra and IL-1β.
Results—No significant differences were found inthe allelic frequencies or allele carriage rates of the markers in theIL-1β and IL-1ra genes between CD, UC, and healthy controls. Noassociation between the genetic markers and cytokine production levelswas observed. Patients with UC carried the combination of both the infrequent allele of the Taq1 RFLP and the Mwo1 RFLP significantly morefrequently (35.2% in UC versus 71.1% in controls).
Conclusions—UC is associatedwith carriage of both infrequent alleles of the Taq1 and Mwo1 RFLPs.However, it could not be confirmed whether the association reflects apathogenic mechanism underlying UC.
相似文献
88.
Bile duct injury after laparoscopic cholecystectomy: the value of endoscopic retrograde cholangiopancreatography. 总被引:3,自引:0,他引:3 下载免费PDF全文
P H Davids J Ringers E A Rauws L T de Wit K Huibregtse M N van der Heyde G N Tytgat 《Gut》1993,34(9):1250-1254
This study describes the value of endoscopic retrograde cholangiopancreatography (ERCP) in patients with bile duct injury after laparoscopic cholecystectomy. Twelve consecutive patients were studied over a one year period. In all patients the biliary tree was visualised during ERCP. Four patients had complete bile duct obstruction, seven patients had a stricture (two with concomitant leakage), and one patient had leakage from a hepatic branch. Three patients with complete obstruction, presented with a relatively prolonged symptom free, 'silent' period before diagnosis. In all four patients with complete transection, a proximal hepaticojejunostomy was performed. In one patient with a tough fibrous stricture, secondary to incorrect clip placement, passage of the guidewire was impossible, leaving surgical reconstruction as the only therapeutic option. All remaining seven patients with leakage or strictures, or both were successfully treated by endoscopic sphincterotomy only (n = 1) or sphincterotomy and subsequent stent placement (n = 6). When patients do not recover uneventfully after laparoscopic cholecystectomy even without cholestasis or jaundice, early ERCP is recommended as a safe and valuable method to detect bile duct injury and to suggest treatment. Subsequently, more than half of such patients can be treated endoscopically. Extended follow up is needed to evaluate the longterm results. 相似文献
89.
C. Y. Ponsioen M.D. K. Lam A.W.M. van Milligen de Wit M.D. Ph.D. K. Huibregtse M.D. Ph.D. G.N.J. Tytgat M.D. Ph.D. 《The American journal of gastroenterology》1999,94(9):2403-2407
OBJECTIVE: Symptomatic dominant strictures in primary sclerosing cholangitis are often treated with endoscopic stent therapy, but the optimal treatment duration is not well established. After a promising pilot study, we now report our 4 yr experience with short term endoscopic stent therapy for relief of dominant strictures. METHODS: Between January 1994 and October 1997, 32 patients with symptomatic primary sclerosing cholangitis with a dominant stricture at endoscopic retrograde cholangiopancreatography were treated with insertion of a 7- or 10-Fr polyethylene endoprosthesis, which was extracted after a mean of 11 days (range 1-23 days). Primary end points were changes in complaints and cholestasis after 2 months, and time interval until a repeat endoscopic treatment was deemed necessary. A secondary end point was the occurrence of treatment-related complications. RESULTS: Cholestatic complaints improved after 2 months in 83% of patients. Mean scores for pruritus, fatigue, and right upper quadrant pain decreased from 0.94, 1.0, and 0.87 to 0.26, 0.39, and 0.26, respectively. All improvements were significant. Of 14 patients presenting with jaundice, 12 regained normal serum bilirubin levels 2 months after short term endoscopic stenting. The mean levels of conjugated bilirubin, alkaline phosphatase, and gamma-glutamyl transpeptidase dropped significantly from 36 micromol/L, 309 U/L, and 426 U/L to 7 micromol/L, 205 U/L, and 258 U/L, respectively. The reintervention-free proportions after 1 and 3 yr were 80% and 60%. Seven transient procedure-related complications occurred in 45 therapeutic endoscopic retrograde cholangiopancreatographies. CONCLUSIONS: Short term endoscopic stenting for symptomatic dominant strictures in primary sclerosing cholangitis is effective and safe, and the beneficial effect is sustained for several years. 相似文献
90.
HLA-DR and -DQ phenotypes in inflammatory bowel disease: a meta-analysis. 总被引:18,自引:0,他引:18 下载免费PDF全文
BACKGROUND: Susceptibility to inflammatory bowel disease (IBD) is partially genetically determined and the HLA class II genes are candidates for a role in genetic susceptibility to IBD, because their products play a central role in the immune response. Multiple studies have reported associations between HLA-DR or -DQ phenotypes and either ulcerative colitis or Crohn's disease, but much of the data are still controversial. AIMS: To estimate overall associations between HLA class II phenotypes and IBD, and to establish the relative risk conferred by HLA-DR and -DQ phenotypes by meta-analysis. METHODS: Medline was searched for publications reporting on the relation between IBD and HLA class II phenotypes. Raw data were extracted by recalculating the number of phenotypes or the number of alleles of the main antigens. Odds ratios and confidence intervals were calculated according to the Mantel-Haenszel method. RESULTS: DR2, DR9, and DRB1*0103 were positively associated with ulcerative colitis, and a negative association was found for DR4 and ulcerative colitis. For Crohn's disease a positive association was found with DR7, DRB3*0301, and DQ4 and a negative association with DR2 and DR3. CONCLUSIONS: Both ulcerative colitis and Crohn's disease are associated with specific HLA class II phenotypes. Further analysis of these phenotypes and subgroup analysis may elucidate how these alleles contribute to susceptibility to IBD. 相似文献