全文获取类型
收费全文 | 107440篇 |
免费 | 5454篇 |
国内免费 | 422篇 |
专业分类
耳鼻咽喉 | 1901篇 |
儿科学 | 3650篇 |
妇产科学 | 2278篇 |
基础医学 | 14191篇 |
口腔科学 | 3259篇 |
临床医学 | 7380篇 |
内科学 | 25968篇 |
皮肤病学 | 3513篇 |
神经病学 | 9174篇 |
特种医学 | 2363篇 |
外国民族医学 | 1篇 |
外科学 | 13017篇 |
综合类 | 650篇 |
一般理论 | 34篇 |
预防医学 | 10317篇 |
眼科学 | 2413篇 |
药学 | 7410篇 |
中国医学 | 610篇 |
肿瘤学 | 5187篇 |
出版年
2023年 | 839篇 |
2022年 | 1900篇 |
2021年 | 3905篇 |
2020年 | 1850篇 |
2019年 | 3453篇 |
2018年 | 4288篇 |
2017年 | 2599篇 |
2016年 | 2504篇 |
2015年 | 2636篇 |
2014年 | 3726篇 |
2013年 | 5362篇 |
2012年 | 7899篇 |
2011年 | 8529篇 |
2010年 | 4642篇 |
2009年 | 3609篇 |
2008年 | 6280篇 |
2007年 | 6452篇 |
2006年 | 5935篇 |
2005年 | 5977篇 |
2004年 | 5378篇 |
2003年 | 5003篇 |
2002年 | 4559篇 |
2001年 | 2650篇 |
2000年 | 3116篇 |
1999年 | 2157篇 |
1998年 | 693篇 |
1997年 | 586篇 |
1996年 | 430篇 |
1995年 | 392篇 |
1994年 | 331篇 |
1993年 | 262篇 |
1992年 | 588篇 |
1991年 | 472篇 |
1990年 | 457篇 |
1989年 | 345篇 |
1988年 | 356篇 |
1987年 | 306篇 |
1986年 | 278篇 |
1985年 | 278篇 |
1984年 | 190篇 |
1983年 | 186篇 |
1982年 | 147篇 |
1981年 | 151篇 |
1980年 | 122篇 |
1979年 | 156篇 |
1978年 | 127篇 |
1974年 | 121篇 |
1973年 | 89篇 |
1971年 | 96篇 |
1969年 | 91篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
目的 通过随机对照的临床研究来对比经口内镜下肌切开术(POEM)、肉毒素注射(BTI)和球囊扩张(BD)治疗贲门失弛缓症的安全性和有效性。方法 2011年11月至2012年5月45例贲门失弛缓症患者被随机平均分配到POEM组、BTI组和BD组。对治疗后3个月的疗效和安全性进行对比分析。主要结果是症状缓解率,次要结果是并发症发生率、下食管括约肌压力(LESP)和食管最大宽度。结果 所有45例患者均成功进行了内镜下的治疗,并且治疗后3个月随访成功率为100%。症状缓解率POEM组为100%,BTI组为66.7%,BD组为93.3%,其中POEM组和BTI组两组间的差异有统计学意义(P<0.05),而POEM组与BD组、BD组与BTI组之间差异无统计学意义。并发症发生率POEM组为13.3%,BTI组为0,BD组为6.7%,但3组间的差异无统计学意义。LESP、食管最大宽度在3组之间比较,术前和术后的差异均无统计学意义。结论 治疗后3个月,POEM的症状缓解率高于BTI和BD,而并发症发生率3种方法相似。 相似文献
992.
Antonio Ríos Zambudio Ana López-Navas Marcos Ayala-García María José Sebastián Anselmo Abdo-Cuza Jeannina Alán Laura Martínez-Alarcón Ector Jaime Ramírez Gerardo Muñoz Gerardo Palacios Juliette Suárez-López Roberto Castellanos Beatriz González Miguel Angel Martínez Ernesto Díaz Pablo Ramírez Pascual Parrilla 《The Journal of heart and lung transplantation》2012,31(8):850-857
993.
Ricardo Becerro de Bengoa Vallejo Marta Elena Losa Iglesias Kevin T. Jules 《The Journal of foot and ankle surgery》2012,51(6):729-733
Hallux valgus, limitus, and rigidus are conditions affecting the first metatarsophalangeal joint that can be treated by arthroplasty. Excessive arthroplasty can compromise the insertion of the tendons at the base of the proximal phalanx of the hallux, leading to first metatarsophalangeal joint plantarflexion weakness, cock-up toe deformity, and altered forefoot loading. The present study investigated the anatomic length of insertion of the medial and lateral flexor hallucis brevis, extensor hallucis brevis, abductor hallucis, and adductor hallucis tendons into the base of the hallux proximal phalanx and the amount of bone that can be safely resected without compromising the insertional limits. A total of 43 specimens (22 right and 21 left) from 22 embalmed cadavers (11 male and 11 female) were dissected. The insertion lengths of the 5 tendons were measured, along with the dimensions of the hallux proximal phalanx. No statistically significant differences were found in any proximal phalanx measurements or tendon insertion lengths according to side (p > .05). Significant differences were found between the genders in most dimensions of the hallux proximal phalanx (p < .05). The medial insertion site, where the medial flexor brevis tendon and distal abductor hallucis muscle join, was longer than the lateral site (p < .001). To preserve the tendon’s insertion, hallux proximal phalanx resection should not exceed 3 mm. Resection of the tendons is ensured by removal of more than 7.88 mm and 9.37 mm in females and males, respectively. When performing hallux arthroplasty of the first metatarsophalangeal joint, we recommend calculating the length of the tendon insertions, instead of the length of the hallux proximal phalanx. 相似文献
994.
Pablo León-Atance Nicolás Moreno-Mata Federico González-Aragoneses Miguel Ángel Cañizares-Carretero Enrique Poblet-Martínez Marta Genovés-Crespo María Dolores García-Jiménez Antonio Francisco Honguero-Martínez Carlos Alberto Rombolá Carlos María Simón-Adiego Rafael Peñalver-Pacual Emilio Álvarez-Fernández 《Archivos de bronconeumologia》2012,48(2):49-54
IntroductionIn the scientific literature, contradictory results have been published on the prognostic value of the loss of expression of blood group antigen A (BAA) in lung cancer. The objective of our study was to analyze this fact in our surgical series.Patients and methodsIn a multicenter study, 402 non-small-cell lung cancer (NSCLC) patients were included. All were classified as stage-I according to the last 2009-TNM classification. We analyzed the prognostic influence of the loss of expression of BAA in the 209 patients expressing blood group A or AB.ResultsThe 5-year cumulative survival was 73% for patients expressing BAA vs 53% for patients with loss of expression (P=.03). When patients were grouped into stages IA and IB, statistical significance was only observed in stage I-A (P=.038). When we analyzed the survival according to histologic type, those patients with adenocarcinoma and loss of expression of BAA had a lower survival rate that was statistically very significant (P=.003). The multivariate analysis showed that age, gender and expression of BAA were independent prognostic factors.ConclusionsThe loss of expression of blood group antigen A has a negative prognostic impact in stage I NSCLC, especially in patients with adenocarcinoma. 相似文献
995.
996.
Moreno-Merino S Congregado M Gallardo G Jimenez-Merchan R Trivino A Cozar F Lopez-Porras M Loscertales J 《Interactive Cardiovascular and Thoracic Surgery》2012,15(1):81-85
Primary spontaneous pneumothorax is a pathology mainly affecting healthy young patients. Clinical guidelines do not specify the type of pleurodesis that should be conducted, due to the lack of comparative studies on the different techniques. The aim of this study was to compare talc poudrage and pleural abrasion in the treatment of spontaneous pneumothorax. A retrospective comparative study was performed, including 787 patients with primary spontaneous pneumothorax. The 787 patients were classified into two groups: Group A (pleural abrasion) n = 399 and Group B (talc pleurodesis) n = 388. The variables studied were recurrence, surgical time, morbidity and in-hospital length of stay. Statistical analysis was done by an unpaired t-test and Fisher's exact test (SSPS 18.0). Statistically significant differences were observed in the variables: surgical time (A: 46 ± 12.3; B: 37 ± 11.8 min; P < 0.001); length of stay (A: 4.7 ± 2.5; B: 4.3 ± 1.8 days; P = 0.01); apical air camera (A: 25; B: 4; P < 0.001); pleural effusion (A: 6; B: 0; P = 0.05). Talc poudrage shows shorter surgical times and length of stay, and lower re-intervention rates. Morbidity is lower in patients with talc poudrage. Statistically significant differences were not observed in recurrence, persistent air leaks, atelectasis and haemothorax. 相似文献
997.
Gervasini G Garcia M Macias RM Cubero JJ Caravaca F Benitez J 《Transplant international》2012,25(4):471-480
We retrospectively examined the association of polymorphisms in the CYP3A, CYP2J2, CYP2C8, and ABCB1 genes with pharmacokinetic (PKs) and pharmacodynamic (PDs) parameters of tacrolimus in 103 renal transplant recipients for a period of 1 year. CYP3A5 expressers had lower predose concentrations (C(0) )/dose and higher dose requirements than nonexpressers throughout the study. Among CYP3A5*1 carriers, those also carrying the CYP3A4*1B allele showed the lowest C(0) /dose, as compared with CYP3A4*1/CYP3A5*3 carriers (54.28±26.45, 59.12±24.00, 62.43±41.12, and 57.01±17.34 vs. 112.37± 76.60, 123.21±59.57, 163.34±76.23, and 183.07±107.82 at 1 week, 1 month, 5 months, and 1 year after transplantation). In addition, CYP3A4*1B/CYP3A5*1 carriers showed significantly lower dose-corrected exposure than CYP3A4*1/CYP3A5*1 carriers 1 year after transplantation (57.01±17.34 vs. 100.09±24.78; P=0.016). Only the ABCB1 TGC (3435-2677-1236) haplotype showed a consistent association with PDs (nephrotoxicity; OR=4.73; CI: 1.3-16.7; P=0.02). Our findings indicate that the CYP3A4*1B-CYP3A5*1 haplotype may have a more profound impact in tacrolimus PKs than the CYP3A5*1 allele. This study does not support a critical role of the CYP450 or ABCB1 single nucleotide polymorphisms in the occurrence of toxicity or acute rejection in renal transplant recipients treated with tacrolimus. 相似文献
998.
Drnovšek N Novak S Dragin U Čeh M Gorenšek M Gradišar M 《International orthopaedics》2012,36(8):1739-1745
Purpose
The aim of the study was to verify the ability of nanoparticulate bioactive glass (BAG) to infiltrate into the porous titanium (Ti) layer on Ti-based implants to promote osseointegration.Methods
The porous titanium layer on Ti-based implants was impregnated with nanoparticulate BAG. The implants without or with BAG were implanted bilaterally in tibial holes of ten New Zealand white rabbits. The rabbits were sacrificed after ten weeks for examinations. Beside histological examination, EDXS analysis of polished cross-sections of explanted implants was also performed with the aim to quantitatively evaluate the bone-to-pore contact and bone-in-pore ratio.Results
After ten weeks, EDXS analyses of cross-sections of the explanted implants confirmed that bioactive glass was fully resorbed and that the pores throughout the thickness of the porous titanium layer were to a large extent filled with a new bone. In the absence of bioactive glass, only the outer part of the porous layer was filled with bone. The implants without BAG in the porous Ti-layer exhibited similar bone-to-pore contact, while significant improvement of bone ingrowth into the pores was observed for the implants with BAG (38%), as opposed to those without it (22%).Conclusion
This study confirmed that the nanoparticulate bioactive glass within the porous titanium surface layer on implants promotes osseointegration and stimulates the formation of bone within the pores. 相似文献999.
It remains unclear whether vitamin D sufficiency optimizes response to bisphosphonate (BP) treatment in postmenopausal osteoporosis. We evaluated the role and possible mechanisms of vitamin D in adequate response to standard BP treatment for postmenopausal osteoporosis.MethodsWe included 120 postmenopausal osteoporotic women (aged 68 ± 8 years) receiving BP (alendronate or risedronate) at their annual follow-up, performing complete anamnesis, including treatment adherence, use of vitamin D supplements, and previous falls and fractures during the last year. We analyzed the evolution of bone mineral density (BMD) during this period and serum PTH and 25 hydroxyvitamin D (25(OH)D) and urinary NTx levels. Patients were classified as inadequate responders to antiosteoporotic treatment based on BMD loss > 2% and/or the presence of fragility fractures during the last year.ResultsThirty percent of patients showed inadequate response to BP treatment, with significantly lower levels of 25(OH)D (22.4 ± 1.3 vs. 26.6 ± 0.3 ng/ml, p = 0.01), a higher frequency of 25(OH)D levels < 30 ng/ml (91% vs. 69%, p = 0.019) and higher urinary NTx values (42.2 ± 3.9 vs. 30.9 ± 2.3 nM/mM, p = 0.01). Patients with 25(OH)D > 30 ng/ml had a greater significant increase in lumbar BMD than women with values < 30 ng/ml (3.6% vs. 0.8%, p < 0.05). The probability of inadequate response was 4-fold higher in patients with 25(OH)D < 30 (OR, 4.42; 95% CI, 1.22–15.97, p = 0.02).ConclusionsInadequate response to BP treatment is frequent in postmenopausal women with osteoporosis as is vitamin D insufficiency, despite vitamin D supplementation. Maintenance of 25(OH)D levels > 30 ng/ml is especially indicated for adequate response to BP treatment. 相似文献
1000.
M Gastaca A Matarranz F Muñoz A Valdivieso A Aguinaga M Testillano J Bustamante I Terreros MJ Suarez M Montejo J Ortiz de Urbina 《Transplantation proceedings》2012,44(6):1554-1556
Despite significant advances in orthotopic liver transplantation (OLT), biliary tract reconstruction is still a major source of complications. Choledochocholedochostomy with a T-tube used to be the standard procedure for biliary reconstruction after OLT. However, many centers currently avoid use of the T-tube because of the high incidence of complications. Our aim was to study the biliary complications occurring at our center when end-to-end choledochocholedochostomy (EE-CC) over a T-tube was used as the standard procedure for biliary reconstruction. A retrospective review was conducted of all patients who underwent liver transplantation from February 1, 1996, to April 30, 2010. Only patients requiring any therapy to treat biliary complications were considered, whereas those with concomitant hepatic artery complications were excluded. The study cohort consisted of 743 patients who had EE-CC with a T-tube.Of these, 73 patients (9.8%) experienced any biliary complication. Anastomotic strictures occurred in 17 patients (2.3%), and non-anastomotic strictures in 2 (0.3%). Fifteen patients with anastomotic strictures were successfully treated by dilatation and stenting. Bile leakage was diagnosed in 39 patients (5.2%). Leakage occurred at the anastomosis in 15 patients (2%), and at the exit site of the T-tube in 24 patients (3.2%). Tube opening was the only treatment used in 30 patients with bile leakage (76.9%). Seven patients experienced leaks after elective T-tube removal (1%). Overall, repeat surgery to manage biliary complications was needed in 9 patients (1.2%). The mortality rate from biliary complications was 0.13%. In conclusion, EE-CC with a T-tube was followed by a low incidence of biliary complications. The complication rate after elective T-tube removal and the repeat surgery rate were extremely low. These results might challenge the current trend to avoid T-tube stenting in OLT. 相似文献