全文获取类型
收费全文 | 6237篇 |
免费 | 466篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 123篇 |
妇产科学 | 96篇 |
基础医学 | 1158篇 |
口腔科学 | 137篇 |
临床医学 | 554篇 |
内科学 | 1260篇 |
皮肤病学 | 200篇 |
神经病学 | 707篇 |
特种医学 | 230篇 |
外科学 | 513篇 |
综合类 | 12篇 |
一般理论 | 6篇 |
预防医学 | 595篇 |
眼科学 | 136篇 |
药学 | 383篇 |
中国医学 | 16篇 |
肿瘤学 | 559篇 |
出版年
2024年 | 9篇 |
2023年 | 65篇 |
2022年 | 108篇 |
2021年 | 190篇 |
2020年 | 125篇 |
2019年 | 167篇 |
2018年 | 171篇 |
2017年 | 184篇 |
2016年 | 200篇 |
2015年 | 236篇 |
2014年 | 263篇 |
2013年 | 348篇 |
2012年 | 533篇 |
2011年 | 537篇 |
2010年 | 302篇 |
2009年 | 288篇 |
2008年 | 413篇 |
2007年 | 442篇 |
2006年 | 380篇 |
2005年 | 388篇 |
2004年 | 316篇 |
2003年 | 308篇 |
2002年 | 250篇 |
2001年 | 58篇 |
2000年 | 48篇 |
1999年 | 51篇 |
1998年 | 44篇 |
1997年 | 43篇 |
1996年 | 22篇 |
1995年 | 23篇 |
1994年 | 29篇 |
1993年 | 18篇 |
1992年 | 28篇 |
1991年 | 17篇 |
1990年 | 12篇 |
1989年 | 14篇 |
1988年 | 5篇 |
1987年 | 13篇 |
1986年 | 9篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1982年 | 8篇 |
1981年 | 7篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1977年 | 6篇 |
1973年 | 3篇 |
1968年 | 2篇 |
排序方式: 共有6719条查询结果,搜索用时 15 毫秒
41.
Stolzenburg JU Franz T Kallidonis P Minh D Dietel A Hicks J Nicolaus M Al-Aown A Liatsikos E 《BJU international》2011,107(6):970-974
Study Type – Therapy (case series) Level of Evidence 4 What’s known on the subject? and What does the study add? The use of robotic arms for instrument and camera manipulation has been proposed for more than a decade. The current study provides a direct comparison of robotic camera movement to the conventional human camera holding assistance in real operative room setting.
OBJECTIVE
? To assess, in a prospective randomized study, the efficiency of the FreeHand® (Prosurgics Ltd, Bracknell, UK) compared to manual camera control during the performance of endoscopic extraperitoneal radical prostatectomy (EERPE).PATIENTS AND METHODS
? Three surgeons performed 50 EERPE for localized prostate cancer. In group A (n= 25), procedures were performed with manual control of the camera by the assistant, whereas group B (n= 25) patients were treated with the assistance of the FreeHand® robotic device. ? The EERPE procedure was divided into several steps. ? Total operation duration, time for each surgical step, number of camera movements, number of movement errors, number of times the lens was cleaned, blood loss and margin status were compared.RESULTS
? No statistically significant difference was observed in terms of patient age, preoperative prostate‐specific antigen level, Gleason score, positive cores and prostate volume. ? The average operation duration required for the performance of each step did not differ significantly between the two groups. ? Significant differences in favour of the FreeHand® camera holder were observed in case of horizontal and zooming camera movement, camera cleaning and camera errors. ? Vertical camera movements were performed significantly faster by the human assistant compared to the robotic camera holder. ? The average total operation duration was similar for both groups. ? Positive surgical margins were detected in one patient in each group (4% of the patients).CONCLUSIONS
? A comparison of the FreeHand® robotic camera holder with human camera control during EERPE showed a similar time requirement for the performance of each step of the procedure. ? The robotic system provided accurate and fast movements of the camera without compromising the outcome of the procedure. 相似文献42.
Stolzenburg JU Rabenalt R Do M Schwalenberg T Winkler M Dietel A Liatsikos E 《European urology》2008,53(5):931-940
OBJECTIVES: Based on our recently published anatomic studies, we present the most recent refinement of the endoscopic extraperitoneal radical prostatectomy (EERPE), the intrafascial nerve-sparing EERPE (nsEERPE). METHODS: As part of the intrafascial technique, the dissection plane is directly on the prostatic capsule, freeing the prostate laterally from its thin surrounding fascia that contains small vessels and nerves. The technique enables puboprostatic ligament preservation, leaving intact endopelvic fascia, periprostatic fascia, and neurovascular bundles. The operation was performed in 150 patients with indications for nerve-sparing procedure. RESULTS: The mean operative time was 131 min (range: 50-210 min) and the mean catheterization time was 5.9 d (range: 4-20 d). Twelve months postoperatively, 94.3% of the patients were continent (no need for pads), 4.6% had minimal stress incontinence, and one patient required >2 pads/d. At the 12-mo follow-up, the potency rates (erections sufficient for intercourse with or without the use of phosphodiesterase 5 [PDE5] inhibitors) of the patients who underwent bilateral intrafascial nsEERPE were 89.7% (age: 44-55 yr), 81.1% (age: 56-65 yr), and 61.9% (age: >65 yr). Positive surgical margins in pT2 and pT3 tumors were 4.5% and 29.4%, respectively. CONCLUSIONS: The intrafascial nsEERPE enables the dissection of the prostate with limited trauma to the surrounding fascias and the enclosed neurovascular bundles. We propose that the preserved neurovascular bundles with intrafascial nsEERPE are more viable. The results advocate this proposition. 相似文献
43.
Reliability of serial bone scintigraphy classification according to Conway in Legg-Calvé-Perthes disease 总被引:2,自引:0,他引:2
Serial bone scintigraphy in Legg-Calvé-Perthes disease (LCP) has a good early prognostic value. So far, no intra- and inter-observer reliability study on this classification has been published. Serial technetium scintigraphy of the hips was performed in 40 children with LCP disease, and the hips were classified based on their scintigraphic patterns according to Conway. Forty hips were classified twice by six observers. The two assessments were made in a different order, with a minimum time interval of one month. Unweighted kappa coefficients were calculated. Only moderate reliability was measured: intra-observer reliability: kappa = 0.573 and inter-observer reliability: kappa = 0.525. Serial bone scintigraphy in LCP has an inter- and intra-observer reliability that is only moderate. The reliability is better than that observed for the radiological Catterall classification and head-at-risk factors, but worse than the reliability of the radiological Herring classification. 相似文献
44.
Endothelial cell dysfunction after coronary artery bypass grafting with extracorporeal circulation in patients with type 2 diabetes mellitus. 总被引:1,自引:0,他引:1
Karla Lehle Jürgen G Preuner Anja Vogt Leopold Rupprecht Andreas Keyser Reinhard Kobuch Christof Schmid Dietrich E Birnbaum 《European journal of cardio-thoracic surgery》2007,32(4):611-616
OBJECTIVE: Type 2 diabetes mellitus is a well-known risk factor in patients with severe coronary artery disease undergoing coronary artery bypass grafting (CABG). The aim of the study was to analyze the endothelial dysfunction in these patients by evaluating postoperative soluble inflammatory cytokines. METHODS: Patients undergoing CABG without (n=15, group A) and with (n=14, group B) diabetes mellitus were analyzed for their release of E-selectin, interleukin-6 (IL-6), and tumor necrosis factor (TNF) up to 3 days postoperatively. A pharmacokinetic quantitative kinetic evaluation (Kinetica 2000) of maximum concentrations (c(max)), time to reach c(max) (t(max)), area under the curve (AUC(0-inf)), and terminal elimination half time (t(1/2)) was performed using a non-compartmental model. RESULTS: There was no difference in preoperative plasma concentrations of the cytokines and in the postoperative kinetic analyses of TNF when comparing both groups. However, the release of IL-6 was restricted with c(max) of 1055+/-543 pg/ml for group B versus 2112+/-1532 pg/ml for group A (p< or =0.05), paralleled by a decrease in the absolute amount (AUC(0-inf)) of IL-6. The t(1/2) remained unaffected (13.9+/-6.6h and 12.7+/-4.6h, respectively). The AUC(0-inf) of E-selectin decreased by a factor of 1.7 (p< or =0.05) with unchanged c(max) but reduced t(1/2) (12.9+/-10h for group B vs 33.1+/-20.4h for group A; p< or =0.01) referring to an augmented endothelial uptake and degradation of E-selectin. CONCLUSIONS: CABG with extracorporeal circulation could be used to verify a specific endothelial dysfunction in diabetic patients characterized by an impaired release of IL-6 and an increased turnover of E-selectin. 相似文献
45.
46.
Dieter P. Hoyer Martin Munteanu Ali Canbay Matthias Hartmann Anja Gallinat Andreas Paul Fuat H. Saner 《Transplant international》2014,27(6):625-633
Factors predicting survival after liver transplantation (LT) for irreversible acute liver failure (ALF) are rare. The aim of this study was to identify prognostic preoperative factors of patients with ALF that predict mortality after LT to avoid futile transplantation. From chart review, we identified 57 patients receiving transplants for ALF from 12/2000 to 09/2010. Recipient and donor data were analyzed and correlated with in‐hospital mortality and patient survival by univariable/multivariable logistic regression and Cox proportional hazards. The survival rates at 30 days and 12 months were 77.2% and 64.9%, respectively. The in‐hospital mortality rate was 29.8%. Follow‐up of patients discharged from the hospital alive showed 30‐day and 12‐month survivals of 100% and 92.5%, respectively. Multivariable analysis of factors known preoperatively showed that the lowest pH of the recipient before LT (P = 0.03) was independently associated with in‐hospital mortality, and the recipient's BMI (P = 0.03) and the lowest pH before LT (P = 0.03) were independently associated with patient survival. A pH of 7.26 was the calculated cutoff (ROC) for increased in‐hospital mortality. Donor factors did not affect patient survival. Patients with ALF and a pH ≤ 7.26 have the worst outcome after liver transplantation. Therefore, emergency liver transplantation should be critically discussed for each individual. 相似文献
47.
Purpose
The aim of this study was to compare the results of primary total knee arthroplasty with or without patelloplasty.Methods
We retrospectively reviewed 89 patients who had received total knee arthroplasty. In patelloplasty, the patellar cartilage was resected using a tangential saw cut, and in the traditional treatment, only the surrounding osteophytes were removed. The outcome was measured using radiographs, Knee Injury and Osteoarthritis Outcome Score, Oxford Knee Score, Knee Society Score, Knee Society Function Score and Knee Society Pain Score.Results
Patelloplasty patients had a better outcome according to the Oxford Knee Score (P = 0.012), Knee Injury and Osteoarthritis Outcome Score (P = 0.003) and all of the Knee Injury and Osteoarthritis Outcome Score subscales (P < 0.05). The patella was significantly thinner (P = 0.001) post-operatively in the patelloplasty patients, but there was no statistically significant correlation between Oxford Knee Score or Knee Injury and Osteoarthritis Outcome Score and post-operative patellar thickness in the patelloplasty group.Conclusions
In this follow-up, patelloplasty was better than traditional treatment in relieving pain and improving function and quality of life. 相似文献48.
Dagmara Borzych-Duzalka Yelda Bilginer Il Soo Ha Mustafa Bak Lesley Rees Francisco Cano Reyner Loza Munarriz Annabelle Chua Silvia Pesle Sevinc Emre Agnieszka Urzykowska Lily Quiroz Javier Darío Ruscasso Colin White Lars Pape Virginia Ramela Nikoleta Printza Andrea Vogel Dafina Kuzmanovska Eva Simkova Dirk E. Müller-Wiefel Anja Sander Bradley A. Warady Franz Schaefer for the International Pediatric Peritoneal Dialysis Network Registry 《Journal of the American Society of Nephrology : JASN》2013,24(4):665-676
Little information exists regarding the efficacy, modifiers, and outcomes of anemia management in children with CKD or ESRD. We assessed practices, effectors, and outcomes of anemia management in 1394 pediatric patients undergoing peritoneal dialysis (PD) who were prospectively followed in 30 countries. We noted that 25% of patients had hemoglobin levels below target (<10 g/dl or <9.5 g/dl in children older or younger than 2 years, respectively), with significant regional variation; levels were highest in North America and Europe and lowest in Asia and Turkey. Low hemoglobin levels were associated with low urine output, low serum albumin, high parathyroid hormone, high ferritin, and the use of bioincompatible PD fluid. Erythropoiesis-stimulating agents (ESAs) were prescribed to 92% of patients, and neither the type of ESA nor the dosing interval appeared to affect efficacy. The weekly ESA dose inversely correlated with age when scaled to weight but did not correlate with age when normalized to body surface area. ESA sensitivity was positively associated with residual diuresis and serum albumin and inversely associated with serum parathyroid hormone and ferritin. The prevalence of hypertension and left ventricular hypertrophy increased with the degree of anemia. Patient survival was positively associated with achieved hemoglobin and serum albumin and was inversely associated with ESA dose. In conclusion, control of anemia in children receiving long-term PD varies by region. ESA requirements are independent of age when dose is scaled to body surface area, and ESA resistance is associated with inflammation, fluid retention, and hyperparathyroidism. Anemia and high ESA dose requirements independently predict mortality.Almost three decades after the advent of recombinant erythropoietin, the management of renal anemia has become a recent focus of attention and changing paradigms. Whereas correction of hemoglobin (Hb) levels to near-normal has previously been recommended on the basis of association studies linking more severe anemia to morbidity and mortality with dialysis,1–3 interventional clinical trials consistently demonstrate that near-normalization of Hb increases the risk of vascular events and mortality in adults receiving maintenance hemodialysis and in those with CKD who are not undergoing dialysis.4–6 This has prompted ongoing reevaluation and revisions of treatment targets in patients exposed to erythropoiesis-stimulating agents (ESAs).7The appropriateness of applying treatment recommendations established in adult hemodialysis populations at high cardiovascular risk and adults with CKD to children undergoing dialysis is questionable because cardiovascular events are far less common in children with CKD. Furthermore, two thirds of children requiring dialysis initially opt for peritoneal dialysis (PD), and there are no systematic studies in the adult PD population to inform the optimal Hb target range in these patients. The risk profile of patients receiving PD may differ from that of the hemodialysis setting because of the absence of dialysis-induced intermittent hemoconcentration and lack of contact activation of the complement and coagulation systems.Further aspects to consider in pediatric anemia management are the greater physical activity of children and the need for optimal cognitive functioning at school.8,9 The significant physiologic variation of the normal Hb range with age10 and the relative ESA sensitivity that reportedly increases with age during early childhood are also noteworthy.11The registry of the International Pediatric Peritoneal Dialysis Network (IPPN) prospectively collects detailed clinical, biochemical, dialysis, and medication-related information (including ESA types and doses and modalities of iron supplementation) from a substantial number of children undergoing long-term PD around the world. In-depth analysis of this unique database has allowed us to (1) gain insight into the demographic characteristics of renal anemia and its treatment in the pediatric PD population worldwide, (2) explore the relationship between ESA dose requirements and body dimensions, (3) identify factors contributing to ESA resistance in children, and (4) associate anemia control with patient outcomes. 相似文献
49.
Probiotics partly reverse increased bacterial translocation after simultaneous liver resection and colonic anastomosis in rats 总被引:11,自引:0,他引:11
Seehofer D Rayes N Schiller R Stockmann M Müller AR Schirmeier A Schaeper F Tullius SG Bengmark S Neuhaus P 《The Journal of surgical research》2004,117(2):262-271
BACKGROUND: Bacterial translocation is one important cause of nosocomial infections following major abdominal surgery. Oral administration of probiotics has been proposed to diminish bacterial translocation. MATERIAL AND METHODS: In total 68 rats were divided into seven groups: five of the groups received standard rat chow and were subjected to either sham-operation, 70% liver resection, colonic anastomosis, or a combination of 30 or 70% liver resection with synchronous colonic anastomosis, respectively. In two additional groups with synchronous operation, a combination of four different lactic acid bacteria and four fibers was administered two times daily pre- and postoperatively. Bacterial concentrations in cecum, mesenteric lymph nodes, liver, and spleen were analyzed and blood cultures were taken 48 h after operation. Furthermore, the following parameters were assessed: histological changes in the intestine, intestinal paracellular permeability (Ussing chamber), bursting pressure of the colonic anastomosis, and mitosis rate of the remnant liver. RESULTS: Bacterial translocation was observed in all rats, except in the sham group. Following liver resection, the highest bacterial concentrations were seen in liver and spleen, following colon anastomosis in the mesenteric lymph nodes. Bacterial translocation was increased in the animals with combined operation, in parallel to the extent of liver resection. In rats with colon anastomosis, bacterial concentration in the cecum was also higher than in the sham group. Application of probiotics significantly decreased bacterial concentration in the lymph nodes. In addition, animals with a high cecal concentration of lactobacilli had less translocation than the others. No histological changes were observed in the intestine. Paracellular permeability for ions, but not for the larger molecule lactulose, was increased in the colon in all groups with colon anastomosis. The bursting pressure of the colon anastomosis was not significantly different between the groups. Seventy percent liver resection led to a high rate of hepatocyte mitosis, whereas combination with colon anastomosis impaired the regeneration process. CONCLUSION: Synchronous liver resection and colon anastomosis led to increased bacterial translocation compared to the single operations in the rat model. It is possible to diminish this process by oral administration of probiotics. Bacterial overgrowth in the cecum and impaired hepatic regeneration, but not histological changes or alterations of paracellular permeability, are potential pathogenic mechanisms for translocation in this setting. 相似文献
50.
Summary To clarify the heterogeneity of Type 1 (insulin-dependent) diabetes mellitus, differences between patients with different HLA risk antigens were investigated with regard to sex, age at diagnosis, season of year and calendar year at diagnosis of the disease. The study consisted of 293 HLA-typed patients from the Department of Paediatrics, University of Oulu, Oulu, Finland. HLA-Dw2 was extremely rare among diabetic patients, whereas Dw3 and Dw4 were associated with increased risk in this as in other series. Male patients more often had the HLA-A1 antigen than females. On comparison of the Dw3 positive patients, boys more frequently had the combination A1,B8 than girls. A1,B8-positive patients were more often diagnosed during the warm months, in the late summer and autumn. Patients with both Dw3 and Dw4 were younger at diagnosis when compared with the rest of the patients. The results support the concept of heterogeneity in the pathogenesis of Type 1 diabetes associated with HLA-linked genetic determinants. 相似文献