全文获取类型
收费全文 | 5433篇 |
免费 | 318篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 75篇 |
儿科学 | 105篇 |
妇产科学 | 81篇 |
基础医学 | 678篇 |
口腔科学 | 380篇 |
临床医学 | 480篇 |
内科学 | 1158篇 |
皮肤病学 | 90篇 |
神经病学 | 442篇 |
特种医学 | 197篇 |
外科学 | 832篇 |
综合类 | 24篇 |
一般理论 | 2篇 |
预防医学 | 377篇 |
眼科学 | 82篇 |
药学 | 419篇 |
中国医学 | 16篇 |
肿瘤学 | 328篇 |
出版年
2023年 | 27篇 |
2022年 | 36篇 |
2021年 | 82篇 |
2020年 | 60篇 |
2019年 | 73篇 |
2018年 | 126篇 |
2017年 | 96篇 |
2016年 | 124篇 |
2015年 | 138篇 |
2014年 | 142篇 |
2013年 | 271篇 |
2012年 | 368篇 |
2011年 | 357篇 |
2010年 | 239篇 |
2009年 | 224篇 |
2008年 | 330篇 |
2007年 | 332篇 |
2006年 | 343篇 |
2005年 | 369篇 |
2004年 | 358篇 |
2003年 | 343篇 |
2002年 | 317篇 |
2001年 | 51篇 |
2000年 | 30篇 |
1999年 | 57篇 |
1998年 | 74篇 |
1997年 | 52篇 |
1996年 | 42篇 |
1995年 | 48篇 |
1994年 | 38篇 |
1993年 | 30篇 |
1992年 | 32篇 |
1991年 | 41篇 |
1990年 | 25篇 |
1989年 | 29篇 |
1988年 | 31篇 |
1987年 | 36篇 |
1986年 | 25篇 |
1985年 | 30篇 |
1984年 | 34篇 |
1983年 | 21篇 |
1982年 | 31篇 |
1981年 | 26篇 |
1980年 | 19篇 |
1979年 | 18篇 |
1978年 | 21篇 |
1977年 | 21篇 |
1976年 | 16篇 |
1975年 | 18篇 |
1974年 | 19篇 |
排序方式: 共有5766条查询结果,搜索用时 31 毫秒
101.
Udo A. Heuschen M.D. Erik H. Allemeyer M.D. Ulf Hinz M.Sc. Frank Autschbach M.D. Tanja Uehlein Christian Herfarth M.D. Gundi Heuschen M.D. 《Diseases of the colon and rectum》2002,45(6):776-786
PURPOSE: Pouchitis represents a serious threat to patients with ulcerative colitis after restorative proctocolectomy with ileal pouch-anal anastomosis. The frequency of pouchitis is high, and it implies the risk of pouch failure and the risk of malignant mucosal transformation in the pouch. Early detection and precise classification of the inflammatory process are required for adequate therapy, which might be facilitated using a scoring system. The aim of the present study was to validate two existing scoring systems in routine outpatient practice.
METHOD: The Heidelberg Pouchitis Activity Score and the Pouchitis Disease Activity Index developed at the Mayo Clinic were simultaneously prospectively applied in a consecutive series of 103 outpatient consultations of 41 patients at our hospital and comparatively validated against the diagnosis of pouchitis or no pouchitis concurrently made by a physician and a surgeon.
RESULTS: The median score of examinations in which the clinicians diagnosis was consistent with pouchitis were significantly higher than those of examinations inconsistent with pouchitis in both scoring systems (Heidelberg Pouchitis Activity Score, 17 (interquartile range, 14–21) and 8 (interquartile range, 5–10), respectively, P < 0.001; Pouchitis Disease Activity Index, 7 (interquartile range, 5–8) and 2.5 (interquartile range, 1–4), respectively, P < 0.001). The sensitivity and specificity in the two total scores were 84 and 79.5 percent, respectively (Heidelberg Pouchitis Activity Score), and 60 and 96.2 percent, respectively (Pouchitis Disease Activity Index); in the field clinical manifestations 44 and 73.1 percent, respectively (Heidelberg Pouchitis Activity Score), and 20 and 87.2 percent, respectively (Pouchitis Disease Activity Index); in the field endoscopic manifestations 88 and 83.3 percent, respectively (Heidelberg Pouchitis Activity Score), and 60 and 89.7 percent, respectively (Pouchitis Disease Activity Index); and in the field histologic manifestations 72 and 76.9 percent, respectively (Heidelberg Pouchitis Activity Score), and 44 and 96.2 percent, respectively (Pouchitis Disease Activity Index). Lowering the cutoff point for diagnosis of pouchitis in the Pouchitis Disease Activity Index by 2 points (pouchitis: score 5) would result in an 88 percent sensitivity and a 67 percent specificity.
CONCLUSIONS: Specificity and sensitivity of the Heidelberg Pouchitis Activity Score were satisfactory. The cutoff point for diagnosing pouchitis in the Pouchitis Disease Activity Index would have to be lowered to reach an acceptable sensitivity and specificity. The very poor validity of the field clinical manifestations in diagnosing pouchitis emphasizes the need for endoscopic and histologic examination for detection of pouchitis. The issue of whether the diagnosis of pouchitis should be based on endoscopic and histologic features alone, instead of additionally taking clinical features into account, should be addressed in future studies. 相似文献
102.
Marcus Bahra Dietmar Jacob Jan M. Langrehr Ulf P. Neumann Peter Neuhaus 《Journal of hepato-biliary-pancreatic sciences》2008,15(5):501-507
Background/Purpose
Carcinoma of the distal bile duct is associated with poor prognosis. Surgical resection remains the only potentially curative treatment. We conducted a retrospective study to identify prognostic factors determining longterm survival.Methods
From 1990 to 2006, 95 patients with distal and/or middle bile duct carcinoma had resections. Fifty-four patients underwent pylorus-preserving pancreaticoduodenectomy (57%) and 41 patients underwent standard Kausch-Whipple pancreaticoduodenectomy (43%). Nine patients underwent pancreaticoduodenectomy including portal vein resection (9%).Results
Overall 1-, 3-, and 5-year survival rates were 60%, 36%, and 29%, respectively. Five-year survival after R0 resection was 34%, and after R1 resection it was 0%. Four patients died during their hospital stay (4%). Multivariate analysis showed negative resection margins (P = 0.040), lymphatic vessel invasion (P = 0.036), and portal vein infiltration (P = 0.027) as strong predictors for survival, whereas the location of the tumor (distal bile duct vs middle bile duct) and lymph node status were not identified as independent prognostic factors.Conclusions
Five-year survival depends strongly on negative resection margins, independent of nodal status. Portal vein resections in patients with portal vein involvement fail to ameliorate long-term survival. Primary tumor site — middle bile duct or distal bile duct — did not determine prognosis.103.
Susanna?Nikolaus Georg?H.?Waetzig Sven?Butzin Monika?Ziolkiewicz Natalie?Al-Massad Florian?Thieme Ulf?L?vgren Birgitte?B.?Rasmussen Torsten?M.?Reinheimer Dirk?Seegert Philip?Rosenstiel Silke?Szymczak Stefan?SchreiberEmail authorView authors OrcID profile 《International journal of colorectal disease》2018,33(7):927-936
Purpose
Interleukin-6 (IL-6) production and signalling are increased in the inflamed mucosa in inflammatory bowel diseases (IBD). As published serum levels of IL-6 and its soluble receptors sIL-6R and sgp130 in IBD are from small cohorts and partly contradictory, we systematically evaluated IL-6, sIL-6R and sgp130 levels as markers of disease activity in Crohn’s disease (CD) and ulcerative colitis (UC).Methods
Consecutive adult outpatients with confirmed CD or UC were included, and their disease activity and medication were monitored. Serum from 212 CD patients (815 measurements) and 166 UC patients (514 measurements) was analysed, and 100 age-matched healthy blood donors were used as controls.Results
IL-6 serum levels were significantly elevated in active versus inactive CD and UC, also compared with healthy controls. However, only a fraction of IBD patients showed increased serum IL-6. IL-6 levels ranged up to 32.7 ng/mL in active CD (>?5000-fold higher than in controls), but also up to 6.9 ng/mL in inactive CD. Increases in active UC (up to 195 pg/mL) and inactive UC (up to 27 pg/mL) were less pronounced. Associations between IL-6 serum levels and C-reactive protein concentrations as well as leukocyte and thrombocyte counts were observed. Median sIL-6R and sgp130 levels were only increased by up to 15%, which was considered of no diagnostic significance.Conclusions
Only a minority of IBD patients shows elevated IL-6 serum levels. However, in these patients, IL-6 is strongly associated with disease activity. Its soluble receptors sIL-6R and sgp130 do not appear useful as biomarkers in IBD.104.
Frilling B Schiele R Gitt AK Zahn R Schneider S Glunz HG Gieseler U Jagodzinski E Senges J;Maximal Individual Therapy in Acute Myocardial Infarction Study Group 《American heart journal》2004,148(2):306-311
Background
A meta-analysis of randomized trials has shown a significant reduction of mortality rate in patients receiving aspirin for secondary prevention after acute myocardial infarction (AMI). However, a significant number of patients do not receive aspirin after AMI. Little is known about why aspirin is withheld or the long-term outcome of these patients today.Methods
The Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) registry is a multicenter registry of patients with AMI in Germany.Results
Of 4902 patients, 509 (10%) did not receive aspirin at the time of discharge from the hospital. The mean follow-up period for these patients was 17 months. Relative contraindications to aspirin were significantly associated with the withholding of aspirin (in-hospital bleeding: odds ratio [OR], 3.56; 95% CI, 1.86-6.80; history of peptic ulcer: OR, 2.49; 95% CI, 1.62-3.83). Absolute contraindications to aspirin were rare (2.2%). Other medications of proven benefit were also given less often in these patients (β-blockers: 49.0% vs 61.9%, P <.001; angiotensin-converting enzyme inhibitors: 65.6% vs 70.2%, P = .06; statins: 12.2% vs 15.1%, P = .10). Patients who were not given aspirin were at high risk for vascular events. They were more likely to have a history of prior AMI (OR, 1.34; 95% CI, 1.02-1.79), were in critical clinical condition at admission more often (cardiogenic shock: OR, 1.98; 95% CI, 1.09-3.56; overt heart failure: OR, 1.6; 95% CI, 1.05-2.3), and received acute revascularization less often (OR, 1.32; 95% CI, 1.05-1.67). The 1-year mortality was 2-times higher in patients who did not receive aspirin than in patients who did receive aspirin (16.5% vs 8.3%, P <.001). A significant association of withheld aspirin at discharge with a higher long-term mortality rate was confirmed with multivariate analysis (OR, 1.62; 95% CI, 1.15-2.29).Conclusions
Ten percent of patients who sustained an AMI did not receive aspirin at the time of hospital discharge. Most of these patients were at high risk for cardiovascular events. Withheld aspirin was significantly associated with higher mortality rate during follow up. 相似文献105.
Harald?S?derb?ckEmail authorView authors OrcID profile Ulf?Gunnarsson Per?Hellman Gabriel?Sandblom 《International journal of colorectal disease》2018,33(10):1411-1417
Background
Our knowledge on the incidence of incisional hernia and risk factors for developing incisional hernia following surgery for colorectal cancer is far from complete.Methods
All procedures registered in the Swedish Colorectal Cancer Register (SCRCR) 2007–2013 were identified. Patients with comorbid disease diagnoses, registered at admissions and visits prior to the procedure and relevant to this study, were obtained from the National Patient Register (NPR). These diagnoses included cardiovascular disease, connective tissue disorders, liver cirrhosis, renal failure, diabetes, chronic obstructive lung disease and chronic inflammatory conditions. Data on occurrence of incisional hernias were obtained by combining data from the SCRCR and the NPR (International Classification of Diseases code).Results
During 2007–2013, 39,984 procedures were registered in the SCRCR. After excluding laparoscopic procedures, procedures repeated on the same patient, procedures with concomitant liver resection and procedures without laparotomy, 28,913 cases remained for analysis. Five years after surgery, the cumulative incidence of incisional hernia was 5.3%. In multivariate proportional hazard analysis, significantly increased risk for incisional hernia was found for the male gender (hazard ratio [HR] 1.40, 95% confidence interval [CI] 1.21–1.62), operation time exceeding 180 min (HR 1.25, CI 1.08–1.45), body mass index (BMI) >?30 (HR 1.78, CI 1.51–2.09), age <?70 years (HR 1.34, CI 1.16–1.56) and postoperative wound complication (HR 2.09, CI 1.70–2.58).Discussion
Men, patients younger than 70 years and patients with BMI?>?30 face a higher risk for incisional hernia. The risk is also increased in cases where the procedure takes longer than 3 h or where postoperative wound complications occur. These patients will benefit from measures aimed at preventing the development of incisional hernia.106.
Li X Tjwa M Van Hove I Enholm B Neven E Paavonen K Jeltsch M Juan TD Sievers RE Chorianopoulos E Wada H Vanwildemeersch M Noel A Foidart JM Springer ML von Degenfeld G Dewerchin M Blau HM Alitalo K Eriksson U Carmeliet P Moons L 《Arteriosclerosis, thrombosis, and vascular biology》2008,28(9):1614-1620
107.
Development of a synthetic tissue engineered three‐dimensional printed bioceramic‐based bone graft with homogenously distributed osteoblasts and mineralizing bone matrix in vitro
下载免费PDF全文
![点击此处可从《Journal of tissue engineering and regenerative medicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Renate Gildenhaar Georg Berger Cynthia Gomes Ulf Linow Martin Hardt Barbara Peleska Jens Günster Michael Stiller Alireza Houshmand Khaled Abdel Ghaffar Ahmed Gamal Mohamed El‐Mofty Christine Knabe 《Journal of tissue engineering and regenerative medicine》2018,12(1):44-58
Over the last decade there have been increasing efforts to develop three‐dimensional (3D) scaffolds for bone tissue engineering from bioactive ceramics with 3D printing emerging as a promising technology. The overall objective of the present study was to generate a tissue engineered synthetic bone graft with homogenously distributed osteoblasts and mineralizing bone matrix in vitro, thereby mimicking the advantageous properties of autogenous bone grafts and facilitating usage for reconstructing segmental discontinuity defects in vivo. To this end, 3D scaffolds were developed from a silica‐containing calcium alkali orthophosphate, using, first, a replica technique – the Schwartzwalder–Somers method – and, second, 3D printing, (i.e. rapid prototyping). The mechanical and physical scaffold properties and their potential to facilitate homogenous colonization by osteogenic cells and extracellular bone matrix formation throughout the porous scaffold architecture were examined. Osteoblastic cells were dynamically cultured for 7 days on both scaffold types with two different concentrations of 1.5 and 3 × 109 cells/l. The amount of cells and bone matrix formed and osteogenic marker expression were evaluated using hard tissue histology, immunohistochemical and histomorphometric analysis. 3D‐printed scaffolds (RPS) exhibited more micropores, greater compressive strength and silica release. RPS seeded with 3 × 109 cells/l displayed greatest cell and extracellular matrix formation, mineralization and osteocalcin expression. In conclusion, RPS displayed superior mechanical and biological properties and facilitated generating a tissue engineered synthetic bone graft in vitro, which mimics the advantageous properties of autogenous bone grafts, by containing homogenously distributed terminally differentiated osteoblasts and mineralizing bone matrix and therefore is suitable for subsequent in vivo implantation for regenerating segmental discontinuity bone defects. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
108.
109.
Mia Forslin Katharina Fink Ulf Hammar Lena von Koch Sverker Johansson 《Archives of physical medicine and rehabilitation》2018,99(8):1483-1490
Objective
To identify predictors for employment status after 10 years in a cohort of people with multiple sclerosis (MS), with the aim to increase knowledge concerning factors present at an early stage that are important for working life and work-life balance.Design
A 10-year longitudinal observational cohort study.Setting
University hospital.Participants
A consecutive sample of people with MS (N=154) of working age were included at baseline, of which a total of 116 people participated in the 10-year follow-up; 27 people declined participation and 11 were deceased.Interventions
Not applicable.Main Outcome Measures
Baseline data on personal factors and functioning were used as independent variables. Employment status 10 years after baseline, categorized as full-time work, part-time work, and no work, was used as the dependent variable. A generalized ordinal logistic regression was used to analyze the predictive value of the independent variables.Results
Predictors for full- or part-time work after 10 years were young age (P=.002), low perceived physical impact of MS (P=.02), fatigue (P=.03), full-time work (P=.001), and high frequency of social/lifestyle activities (P=.001) at baseline. Low perceived physical impact of MS (P=.02) at baseline also predicted full-time work after 10 years.Conclusions
This study underlines the complexity of working life for people with MS, and indicates that it may be valuable to give more attention to the balance between working and private life, both in clinical practice and future research, to achieve a sustainable working life over time. 相似文献110.
Gregory Y. H. Lip Lars H. Rasmussen S. Bertil Olsson Eva Jensen Bengt Hamrén Ulf G. Eriksson Karin W?hlander 《British journal of clinical pharmacology》2015,80(6):1362-1373
AimsAZD0837 is a novel oral anticoagulant investigated in clinical studies for stroke prevention in patients with atrial fibrillation (AF). It is bioconverted to its active form, AR‐H067637, a potent, specific and reversible thrombin inhibitor. The effects on coagulation biomarkers were correlated with the pharmacokinetic (PK) exposure of AR‐H067637 to guide selection of the effective dose regimen for a confirmatory efficacy study in AF patients.MethodsBlood samples were obtained from 601 AF patients randomized to one of four doses of AZD0837 (blinded treatment) or dose‐adjusted vitamin K antagonists (VKA, open treatment) for 3–9 months. A pharmacodynamic model was developed to describe the time course of the AR‐H067637 exposure dependent effects and the effect of VKA on fibrin D‐dimer. The thrombin generation measured ex vivo in venous plasma was also investigated.ResultsThe PK exposure of AR‐H067637 was stable with an interindividual variability of 33% and no or minor influence of patient demographics or comedications. For AZD0837, D‐dimer levels decreased with more rapid onset than for VKA. The decrease in D‐dimer levels correlated with steady‐state plasma concentrations (C
ss) of AR‐H067637, with a maximum decrease of baseline D‐dimer levels estimated to approximately 60% for both AZD0837 and VKA therapy. The effect on thrombin generation correlated closely with the plasma concentration of AR‐H067637.ConclusionsThe effects on thrombin generation and fibrin D‐dimer levels correlated with the plasma concentration of its active form and provided comparable effects to well‐controlled VKA therapy at an exposure at least corresponding to the 300 mg once daily dose of AZD0837. 相似文献