全文获取类型
收费全文 | 5468篇 |
免费 | 297篇 |
国内免费 | 45篇 |
专业分类
耳鼻咽喉 | 48篇 |
儿科学 | 145篇 |
妇产科学 | 85篇 |
基础医学 | 895篇 |
口腔科学 | 491篇 |
临床医学 | 497篇 |
内科学 | 1255篇 |
皮肤病学 | 180篇 |
神经病学 | 257篇 |
特种医学 | 312篇 |
外科学 | 467篇 |
综合类 | 54篇 |
一般理论 | 1篇 |
预防医学 | 409篇 |
眼科学 | 125篇 |
药学 | 353篇 |
中国医学 | 49篇 |
肿瘤学 | 187篇 |
出版年
2023年 | 49篇 |
2022年 | 112篇 |
2021年 | 175篇 |
2020年 | 109篇 |
2019年 | 101篇 |
2018年 | 180篇 |
2017年 | 100篇 |
2016年 | 106篇 |
2015年 | 162篇 |
2014年 | 188篇 |
2013年 | 252篇 |
2012年 | 277篇 |
2011年 | 300篇 |
2010年 | 208篇 |
2009年 | 137篇 |
2008年 | 210篇 |
2007年 | 221篇 |
2006年 | 210篇 |
2005年 | 158篇 |
2004年 | 123篇 |
2003年 | 121篇 |
2002年 | 111篇 |
2001年 | 81篇 |
2000年 | 86篇 |
1999年 | 79篇 |
1998年 | 100篇 |
1997年 | 101篇 |
1996年 | 112篇 |
1995年 | 80篇 |
1994年 | 82篇 |
1993年 | 84篇 |
1992年 | 72篇 |
1991年 | 55篇 |
1990年 | 55篇 |
1989年 | 81篇 |
1988年 | 70篇 |
1987年 | 59篇 |
1986年 | 64篇 |
1985年 | 49篇 |
1984年 | 64篇 |
1980年 | 51篇 |
1977年 | 40篇 |
1976年 | 41篇 |
1975年 | 38篇 |
1965年 | 52篇 |
1964年 | 50篇 |
1963年 | 47篇 |
1962年 | 41篇 |
1961年 | 40篇 |
1960年 | 66篇 |
排序方式: 共有5810条查询结果,搜索用时 40 毫秒
61.
DAVID M. ALBALA DEAN G. ASSIMOS RALPH V. CLAYMAN JOHN D. DENSTEDT MICHAEL GRASSO JORGE GUTIERREZ-ACEVES ROBERT I. KAHN RAYMOND J. LEVEILLEE JAMES E. LINGEMAN JOSEPH N. MACALUSO JR. LARRY C. MUNCH STEPHEN Y. NAKADA ROBERT C. NEWMAN MARGARET S. PEARLE GLENN M. PREMINGER JOEL TEICHMAN JOHN R. WOODS 《The Journal of urology》2001,166(6):2072-2080
PURPOSE: The efficacy of shock wave lithotripsy and percutaneous stone removal for the treatment of symptomatic lower pole renal calculi was determined. MATERIALS AND METHODS: A prospective randomized, multicenter clinical trial was performed comparing shock wave lithotripsy and percutaneous stone removal for symptomatic lower pole only renal calculi 30 mm. or less. RESULTS: Of 128 patients enrolled in the study 60 with a mean stone size of 14.43 mm. were randomized to percutaneous stone removal (58 treated, 2 awaiting treatment) and 68 with a mean stone size of 14.03 mm. were randomized to shock wave lithotripsy (64 treated, 4 awaiting treatment). Followup at 3 months was available for 88% of treated patients. The 3-month postoperative stone-free rates overall were 95% for percutaneous removal versus 37% lithotripsy (p <0.001). Shock wave lithotripsy results varied inversely with stone burden while percutaneous stone-free rates were independent of stone burden. Stone clearance from the lower pole following shock wave lithotripsy was particularly problematic for calculi greater than 10 mm. in diameter with only 7 of 33 (21%) patients becoming stone-free. Re-treatment was necessary in 10 (16%) lithotripsy and 5 (9%) percutaneous cases. There were 9 treatment failures in the lithotripsy group and none in the percutaneous group. Ancillary treatment was necessary in 13% of lithotripsy and 2% percutaneous cases. Morbidity was low overall and did not differ significantly between the groups (percutaneous stone removal 22%, shock wave lithotripsy 11%, p =0.087). In the shock wave lithotripsy group there was no difference in lower pole anatomical measurements between kidneys in which complete stone clearance did or did not occur. CONCLUSIONS: Stone clearance from the lower pole following shock wave lithotripsy is poor, especially for stones greater than 10 mm. in diameter. Calculi greater than 10 mm. in diameter are better managed initially with percutaneous removal due to its high degree of efficacy and acceptably low morbidity. 相似文献
62.
63.
64.
An experimental vaccine against American dermal leishmaniasis: experience in the State of Espírito Santo, Brazil 总被引:4,自引:0,他引:4
W Mayrink P Williams C A da Costa P A Magalh?es M N Melo M Dias A Oliveira Lima M S Michalick E Ferreira Carvalho G C Barros 《Annals of tropical medicine and parasitology》1985,79(3):259-269
A vaccine prepared from killed and sonicated promastigotes of five Brazilian strains of Leishmania was used during an epidemic of American dermal leishmaniasis that occurred in Viana county, State of Espírito Santo, Brazil. Initially, all of the participants in the vaccination programme had negative reactions to Montenegro antigen. Forty days after the last dose of vaccine had been given, 87.6% of the 216 vaccinated individuals had become Montenegro-positive whereas the 266 unvaccinated persons remained Montenegro-negative. The study area had an unstable population and details are given about the human population changes that occurred during the two-year study period. Taking into account population movements, 1.5% of those vaccinated and 6.4% of the unvaccinated group developed dermal leishmanial lesions by the end of the first year. At the end of the second year, 1.7% of those vaccinated and 8.9% of the unvaccinated group had become infected. The difference in infection rates of the two groups is statistically significant at both the end of the first and second years of observation. Diagnosis of the disease(s) was based on the clinical appearance of lesions combined with parasitological and/or immunological evidence and subsequent responses to treatment. The experience gained in Viana also provided information about the storage and administration of the experimental vaccine which have been used in mounting a randomized clinical trial. 相似文献
65.
In many transplantation centers domino liver transplantation is an established procedure, increasing the number of available liver grafts. Increasingly, grafts from familial amyloidotic polyneuropathy (FAP) patients are used. Ocular involvement is a well known manifestation of FAP, and can be vision-threatening. The aim of this study was to evaluate the risk of development of familial amyloidotic polyneuropathy ocular manifestations in domino liver recipients. Forty-four cirrhotic patients submitted to liver transplantation were studied, with an average of 6 years of follow up after the procedure. Twenty two patients had received a liver from a FAP donor (Group 1) and 22 had received a liver from a non-FAP cadaveric donor (Group 2). Both groups were similar for mean age and gender. Routine ophthalmological examinations with particular attention to amyloid deposition in the anterior segment and vitreous, peripheral retina state, lacrimal functions tests (Schirmer and tear break-up time) and pupillometry (dynamic and static) were performed. No statistically significant differences were observed in all studied ophthalmic parameters between the two groups. No FAP related ophthalmic manifestations were detected after 6 years of domino liver transplantation, but further prospective regular ophthalmological examinations are necessary to detect the eventual development of late ocular manifestations. 相似文献
66.
OBJECTIVE: To describe a technical modification for constructing a vagina in girls with congenital adrenal hyperplasia caused by 21-hydroxylase deficiency, using a narrower skin base but rich subcutaneous tissue, aiming to obtain both longer and larger vaginal segments with better cosmesis of the external genitalia. PATIENTS AND METHODS: From August 1997 to February 2001, 28 girls (aged 5 months to 17 years) had a neovagina constructed using a posterior-based omega-shaped flap. Twenty-six patients had a low vagina entering into the urogenital sinus and two had a high vagina that entered the urogenital sinus. In those with a high vagina the flap procedure was combined with the Passerini-Glazel technique. All the patients were scheduled for vaginal "calibrations" during the first year after surgery and, according to the result, would then undergo vaginal dilatation. RESULTS: Six children were re-operated; five had plastic surgery to correct genital folds that had regained a scrotal aspect, whereas one with a high vagina developed a urethral stricture, with urinary dribbling and infection, and had the urethra reconstructed. These six children are currently well. No hormone therapy was given to one child for 1 year who is scheduled for further surgery for a re-virilized clitoris. Two patients were lost to follow-up. Up to the last visit, 19 girls had not developed a vaginal stricture and the cosmesis of their external genitalia was deemed good. CONCLUSION: The posterior-based omega-shaped flap enabled both the construction of wider vaginal segments with a low risk of developing stenosis in those with a low vagina, and increased vaginal dimension when associated with the Passerini-Glazel technique for those with a high vagina. However, despite good cosmesis of the external genitalia, the follow-up is too short to confirm whether this technique will meet all the expectations. 相似文献
67.
The association of postoperative pulmonary complications in 109,360 patients with pressure‐controlled or volume‐controlled ventilation 下载免费PDF全文
A. Bagchi M. I. Rudolph P. Y. Ng F. P. Timm D. R. Long S. Shaefi K. Ladha M. F. Vidal Melo M. Eikermann 《Anaesthesia》2017,72(11):1334-1343
We thought that the rate of postoperative pulmonary complications might be higher after pressure‐controlled ventilation than after volume‐controlled ventilation. We analysed peri‐operative data recorded for 109,360 adults, whose lungs were mechanically ventilated during surgery at three hospitals in Massachusetts, USA. We used multivariable regression and propensity score matching. Postoperative pulmonary complications were more common after pressure‐controlled ventilation, odds ratio (95%CI) 1.29 (1.21–1.37), p < 0.001. Tidal volumes and driving pressures were more varied with pressure‐controlled ventilation compared with volume‐controlled ventilation: mean (SD) variance from the median 1.61 (1.36) ml.kg?1 vs. 1.23 (1.11) ml.kg?1, p < 0.001; and 3.91 (3.47) cmH2O vs. 3.40 (2.69) cmH2O, p < 0.001. The odds ratio (95%CI) of pulmonary complications after pressure‐controlled ventilation compared with volume‐controlled ventilation at positive end‐expiratory pressures < 5 cmH2O was 1.40 (1.26–1.55) and 1.20 (1.11–1.31) when ≥ 5 cmH2O, both p < 0.001, a relative risk ratio of 1.17 (1.03–1.33), p = 0.023. The odds ratio (95%CI) of pulmonary complications after pressure‐controlled ventilation compared with volume‐controlled ventilation at driving pressures of < 19 cmH2O was 1.37 (1.27–1.48), p < 0.001, and 1.16 (1.04–1.30) when ≥ 19 cmH2O, p = 0.011, a relative risk ratio of 1.18 (1.07–1.30), p = 0.016. Our data support volume‐controlled ventilation during surgery, particularly for patients more likely to suffer postoperative pulmonary complications. 相似文献
68.
DS Keller RN Tahilramani JR Flores-Gonzalez S. Ibarra EM Haas 《Surgical endoscopy》2016,30(6):2192-2198
Background
Our objective was to evaluate the impact of a novel multimodal pain management strategy on intraoperative opioid requirements, postoperative pain, narcotic use, and length of stay.Methods
Consecutive patients undergoing elective laparoscopic colorectal resection were managed with an experimental protocol. The protocol uses a post-induction, pre-incision bilateral TAP block and local peritoneal infiltration at port sites with long-acting liposomal bupivacaine (20 mL long-acting liposomal bupivacaine, 30 mL 0.25 % bupivacaine, 30 mL saline). Experimental patients were matched on age, body mass index, gender, comorbidity, diagnosis, and procedure to a control group that received no block or local wound infiltration. Both groups followed a standardized enhanced recovery pathway. Demographics, perioperative, and postoperative outcomes were evaluated. The main outcome measures were intraoperative opioids, postoperative pain, opioid use, and length of stay.Results
Fifty patients were analyzed—25 experimental and 25 controls. Patients were well matched on all demographics. In both cohorts, the main diagnosis was colorectal cancer and primary procedure performed a segmental resection. Operative times were similar (p = 0.41). Experimental patients received significantly less intraoperative fentanyl (mean 158 mcg experimental vs. 299 mcg control; p < 0.01). The experimental group had significantly lower initial (p < 0.01) and final PACU pain scores (p = 0.04) and shorter LOS (3.0 vs. 4.1 days, p = 0.04) compared to controls. Experimental patients trended toward shorter PACU times and lower opioid use and daily pain scores throughout the hospital stay. Postoperative complication and readmission rates were similar across groups. There were no reoperations or mortality.Conclusions
Our multimodal pain management strategy reduced intraoperative opioid administration. Postoperatively, improvements in PACU time, postoperative pain and narcotic use, and lengths of stay were seen in the experimental cohort. With the favorable finding from the pilot study, further investigation is warranted to fully evaluate the impact of this pain management protocol on patient satisfaction, clinical and financial outcomes.69.
目的探讨单核细胞向巨噬细胞分化过程中CD44 mRNA表达和黏附功能的变化。方法应用豆蔻佛波醇乙酯(PMA)诱导单核细胞系U937向巨噬细胞分化;应用RT-PCR分析U937细胞CD44 mRNA表达变化,并以β-actin作为内参进行半定量评价,并对主要条带进行测序;应用荧光染料BCECF/AM作为探针,测定黏附于激活的内皮细胞上的U937细胞数目。结果与对照组比较,PMA诱导的U937细胞CD44 mRNA总体表达显著增加(P=0.01037),异构体/标准CD44比例显著上升(P=0.0005551),测序结果显示PMA刺激后显著增加的是947 bp(V8 V9 V10)和1208 bp(V7 V8 V9 V10)CD44异构体。同时,PMA刺激后U937细胞黏附功能显著增加(P=0.0029)。结论单核细胞向巨噬细胞分化过程中CD44 mRNA,特别是947bp(V8 V9 V10)和1208 bp(V7 V8 V9 V10)CD44异构体的表达显著增加,可能与细胞黏附功能的增强相关。 相似文献
70.
RNA Synthesis in Cultures of Normal Human Peripheral Blood 总被引:6,自引:0,他引:6
RNA and DNA synthesis were measured in cultures of normal human peripheral blood using tritiated cytidine and thymidine and autoradiographictechnics. RNA synthesis preceded DNA synthesis by 24 hours. RNA synthesisoccurred predominantly in the large and medium-sized "blast-like" cells, butdid occur, to a lesser extent, in the small lymphocytes. RNA synthesis did notoccur in the absence of phytohemagglutinin, nor did DNA synthesis. Mechanisms of action of phytohemagglutinin are discussed with particular referenceto its possible antigenic nature. Submitted on August 12, 1963 Accepted on January 6, 1964 相似文献