全文获取类型
收费全文 | 15254篇 |
免费 | 839篇 |
国内免费 | 148篇 |
专业分类
耳鼻咽喉 | 96篇 |
儿科学 | 321篇 |
妇产科学 | 224篇 |
基础医学 | 1724篇 |
口腔科学 | 413篇 |
临床医学 | 1356篇 |
内科学 | 4763篇 |
皮肤病学 | 180篇 |
神经病学 | 1486篇 |
特种医学 | 607篇 |
外科学 | 2175篇 |
综合类 | 26篇 |
预防医学 | 497篇 |
眼科学 | 138篇 |
药学 | 670篇 |
中国医学 | 9篇 |
肿瘤学 | 1556篇 |
出版年
2023年 | 126篇 |
2022年 | 214篇 |
2021年 | 409篇 |
2020年 | 287篇 |
2019年 | 350篇 |
2018年 | 410篇 |
2017年 | 332篇 |
2016年 | 406篇 |
2015年 | 428篇 |
2014年 | 599篇 |
2013年 | 802篇 |
2012年 | 1158篇 |
2011年 | 1204篇 |
2010年 | 668篇 |
2009年 | 691篇 |
2008年 | 1063篇 |
2007年 | 1133篇 |
2006年 | 1032篇 |
2005年 | 996篇 |
2004年 | 992篇 |
2003年 | 810篇 |
2002年 | 738篇 |
2001年 | 108篇 |
2000年 | 81篇 |
1999年 | 105篇 |
1998年 | 127篇 |
1997年 | 122篇 |
1996年 | 91篇 |
1995年 | 83篇 |
1994年 | 65篇 |
1993年 | 76篇 |
1992年 | 54篇 |
1991年 | 65篇 |
1990年 | 50篇 |
1989年 | 30篇 |
1988年 | 25篇 |
1987年 | 35篇 |
1986年 | 40篇 |
1985年 | 29篇 |
1984年 | 33篇 |
1983年 | 24篇 |
1982年 | 17篇 |
1981年 | 15篇 |
1980年 | 15篇 |
1979年 | 10篇 |
1978年 | 12篇 |
1977年 | 10篇 |
1972年 | 10篇 |
1967年 | 10篇 |
1966年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Multislice computed tomography in the preoperative assessment of adult-to-adult living donor liver transplantation: personal results 总被引:6,自引:0,他引:6
Fraioli F Francone M Catalano C Napoli A Danti M Rossi M Pediconi F Rassariello R 《La Radiologia medica》2003,105(5-6):436-444
PURPOSE: To evaluate the possible role of multislice spiral computed tomography (MSCT) as the sole imaging examination in the preoperative assessment of potential donors undergoing adult-to-adult living donor liver transplantation (LDLT). MATERIALS AND METHODS: Fifteen patients underwent MSCT with 0.5-second gantry rotation time. Pre- (4 X 2.5 mm collimation) and post-contrast (4 X 1 mm collimation) acquisitions during arterial and portal venous phases were performed after intravenous administration of 140 ml of non ionic contrast agent at 4-5 ml/s, with a delay time of 25 and 60 seconds, respectively. Pre-contrast scans with 80 and 140 kVp were acquired at the same level used to assess liver density. Real-time interaction with the post-contrast 3D data set was performed on a dedicated workstation to determine total and lobar liver volume, and to assess arterial and venous vascular anatomy. RESULTS: Steatosis was found in three patients, who as a consequence were excluded as possible candidates. MSCT correctly identified five cases of arterial anatomical variations: two cases of the right hepatic artery arising from the superior mesenteric artery, two cases of the common hepatic artery arising from the superior mesenteric artery and one case of the left hepatic artery arising from left gastric artery. In two cases portal trifurcation was considered a criterion for exclusion. A 4% error in the liver volume calculation was found at surgery, in no case considered significant. Two patients underwent surgery and three have been short-listed. CONCLUSIONS: MSCT enables complete preoperative evaluation of potential donors undergoing LDLT. Total and lobar volume determination provided accurate and reproducible information. MSCT enabled correct surgical planning without intra-operative complications. One of the limits of the technique was the poor visualization of the biliary anatomy with the need to perform an intraoperative cholangiography in all the patients. 相似文献
992.
993.
Rovaris M Comi G Ladkani D Wolinsky JS Filippi M;European/Canadian Glatiramer Acetate Study Group 《AJNR. American journal of neuroradiology》2003,24(1):75-81
BACKGROUND AND PURPOSE: Despite extensive use of MR imaging to provide markers of multiple sclerosis (MS) activity and accumulated disease burden, the magnitude of the relationship between clinical and MR findings is still debated. Using data from the European/Canadian glatiramer acetate (GA) trial, we investigated short-term correlations between clinical and MR measures of disease activity in patients with relapsing-remitting MS (RRMS). METHODS: In a 9-month, double-blinded, placebo-controlled study, 239 patients with RRMS were randomly assigned to receive 20 mg GA (n = 119) or placebo (n = 120). Clinical assessment included monthly neurologic examinations with Expanded Disability Status Scale scoring and visits for symptoms suggestive of relapse. Dual-echo T2-weighted and pre- and postcontrast T1-weighted brain MR images were obtained at baseline and monthly during follow-up. Contrast-enhancing and new T2-hyperintense lesions were counted, and total T2-hyperintense and T1-hypointense lesion volumes were measured. RESULTS: Significant univariate correlations were found between the number of relapses during the study period and the number of enhancing lesions at baseline (r = 0.25) and during follow-up (r = 0.30) in the study population as a whole. Multivariable analysis showed that two independent factors were more strongly correlated with relapse frequency: the number of relapses during the 2 years before entry and the number of on-trial enhancing lesions, in the whole study population and in the placebo group. CONCLUSION: In RRMS, MR imaging measures of inflammatory activity are modestly but significantly correlated with the occurrence of clinical attacks over the short term. Clinical and MR imaging assessment can provide complementary outcome measures for RRMS trials. 相似文献
994.
995.
Beelke M Angeli S Del Sette M Gandolfo C Cabano ME Canovaro P Nobili L Ferrillo F 《Sleep medicine》2003,4(3):219-223
BACKGROUND: Under particular conditions a patent foramen ovale (PFO) can potentially give rise to ischemic stroke by means of paradoxic embolization. In obstructive sleep apnea syndrome (OSAS) right to left shunting (RLSh) can occur through PFO during periods of nocturnal apnea. Our study aimed to evaluate the prevalence of PFO diagnosed by means of transcranial Doppler (TcD) in subjects with OSAS. METHODS: Seventy-eight consecutive subjects with OSAS (mean age 53+/-12 years) and 89 normal controls (mean age 48+/-9 years) underwent TcD with intravenous application of agitated physiological saline solution. The test was performed on patients at rest and during Valsalva maneuver. RESULTS: PFO was present in 21 out of 78 patients with OSA (27%) and in 13 out of 89 control patients (15%). Seventeen out of 21 patients with OSA showed PFO only during Valsalva maneuver (85%) with respect to 12 out of 13 subjects of the control group (92%). Prevalence of PFO in OSAS was statistically different with respect to the control group (P<0.05). However, no statistically significant differences could be found for the prevalence of provocative-only shunting PFO with respect to already at rest shunting PFO in patients with OSAS with respect to the control group. CONCLUSIONS: Prevalence of PFO in subjects with OSA is significantly higher than in normal controls. The shunt is frequently present only during Valsalva maneuver. 相似文献
996.
Duct-to-mucosa versus end-to-side pancreaticojejunostomy reconstruction after pancreaticoduodenectomy: results of a prospective randomized trial 总被引:22,自引:0,他引:22
Bassi C Falconi M Molinari E Mantovani W Butturini G Gumbs AA Salvia R Pederzoli P 《Surgery》2003,134(5):766-771
BACKGROUND: Anastomotic failure is still a significant problem that affects the outcome of pancreaticoduodenectomy. There have been many techniques proposed for the reconstruction of pancreatic digestive continuity, but there have been few prospective and randomized studies that compare their efficacy. METHODS: In the current work, 144 patients who underwent a pancreaticoduodenectomy with soft residual tissue were assigned randomly to receive either a duct-to-mucosa anastomosis (group A) or a 1-layer end-to-side pancreaticojejunostomy (group B). RESULTS: The 2 treatment groups were found not to have any differences in regards to vital statistics, underlying disease, or operative techniques. The postoperative course was complicated in 54% of the 144 patients, with a comprehensive incidence of abdominal complications in 36% (group A, 35%; group B, 38%; P=not significant). The principal complication was pancreatic fistulas, which occurred in 14% of patients (group A, 13%; group B, 15%; P=not significant). Two patients (2%) required reoperation; the postoperative mortality rate was 1%. CONCLUSION: The 2 methods that were studied revealed no significant difference the rate of complications. 相似文献
997.
Libra M Sorio R Buonadonna A Berretta M Stefanovski P Toffoli G Mazzaglia G Cordani N Stivala F Boiocchi M 《Tumori》2003,89(3):311-313
Platinum-based therapy is considered the standard treatment for patients with advanced ovarian cancer. Carboplatin has a more favorable toxicity profile than cisplatin; however, hypersensitivity reactions to carboplatin have been reported occasionally. We reviewed 112 cases of ovarian cancer treated with carboplatin at our institute to identify the hypersensitivity reactions to this chemotherapeutic agent. Hypersensitivity reactions were documented in nine cases (8%). No deaths occurred, but the reactions were judged severe in three of the 112 patients (2.6%). In our own experience with patients showing idiosyncrasy to carboplatin we observed successful resolution after retreatment with cisplatin. Since patients who relapse after initial treatment with carboplatin often respond to it a second time, it is important to continue this treatment. 相似文献
998.
Martino M Morabito F Console G Irrera G Messina G Pucci G Nardi M Nobile F Molica S Cicero G Palazzo S Peta A Musolino C Iacopino P 《Tumori》2003,89(4):385-390
Multiple factors contribute to transplant-related complications after high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation, including conditioning regimens, number of infused stem cells and clinical characteristics of patient at transplant. We compared the transplant-related complications of 141 patients affected with hematological malignancies with those of 109 patients with solid tumors. The total number of peripheral blood stem cell transplantations performed was 339. High-dose chemotherapy mainly consisted of melphalan-, busulphan- or thiotepa-based regimens. Despite the equal number of infused CD34+ cells, patients with a hematological malignancy showed a slower absolute neutrophil count (days to neutrophils > 0.5 x 10(9)/L, 10.6 +/- 3.6 for hematological malignancies versus 9.1 +/- 1.2 for solid tumors, P < 0.0001) and platelet recovery (days to platelets > 20 x 10(9)/L, 16.4 +/- 9.8 for hematological malignancies versus 12.3 +/- 4.1 for solid tumors, P < 0.0001) than patients with a solid tumor. A significantly higher requirement of red blood cell (3.3 +/- 4.1 versus 2.0 +/- 1.9, P < 0.0029) and platelet units (7.5 +/- 10.4 versus 4.2 +/- 3.4, P < 0.0001) was observed for hematological malignancies than for solid tumors. Five graft failures were documented exclusively in patients with a hematological malignancy. Moreover, such patients displayed a longer duration of mucositis (P < 0.0028) and hospital stay (P < 0.0001), but no difference was observed in terms of febrile episodes. Transplant-related mortality was similar between the two groups. In conclusion, patients with a hematological malignancy overall have more complications than those with a solid tumor. 相似文献
999.
Hospital acquired blood stream infection by Ralstonia pickettii in 9 cancer patients related to the heparin solution contamination used to flush the central venous catheter. 相似文献
1000.
Pacini S Gulisano M Peruzzi B Sgambati E Gheri G Gheri Bryk S Vannucchi S Polli G Ruggiero M 《Cancer Detection and Prevention》2003,27(5):327-332
Human skin fibroblasts were exposed to 0.2 T static magnetic field generated by a magnetic resonance tomograph. After 1h exposure, cell morphology was modified in association with a concomitant decrease in the expression of some sugar residues of glycoconjugates. Study of cell proliferation and mitogenic signal transduction showed a decrease of thymidine incorporation and of second messenger formation. However, cell viability, assessed by colony forming assay, was unaffected. These results demonstrate that the static magnetic field generated by routinely used magnetic resonance tomograph induces alterations on human skin fibroblasts. 相似文献