全文获取类型
收费全文 | 9848篇 |
免费 | 598篇 |
国内免费 | 65篇 |
专业分类
耳鼻咽喉 | 75篇 |
儿科学 | 271篇 |
妇产科学 | 247篇 |
基础医学 | 1459篇 |
口腔科学 | 297篇 |
临床医学 | 995篇 |
内科学 | 2190篇 |
皮肤病学 | 190篇 |
神经病学 | 1076篇 |
特种医学 | 200篇 |
外科学 | 784篇 |
综合类 | 38篇 |
一般理论 | 3篇 |
预防医学 | 848篇 |
眼科学 | 167篇 |
药学 | 743篇 |
中国医学 | 19篇 |
肿瘤学 | 909篇 |
出版年
2024年 | 13篇 |
2023年 | 95篇 |
2022年 | 232篇 |
2021年 | 334篇 |
2020年 | 225篇 |
2019年 | 241篇 |
2018年 | 293篇 |
2017年 | 228篇 |
2016年 | 274篇 |
2015年 | 314篇 |
2014年 | 431篇 |
2013年 | 570篇 |
2012年 | 745篇 |
2011年 | 789篇 |
2010年 | 400篇 |
2009年 | 358篇 |
2008年 | 642篇 |
2007年 | 699篇 |
2006年 | 641篇 |
2005年 | 556篇 |
2004年 | 536篇 |
2003年 | 486篇 |
2002年 | 480篇 |
2001年 | 51篇 |
2000年 | 40篇 |
1999年 | 69篇 |
1998年 | 84篇 |
1997年 | 80篇 |
1996年 | 51篇 |
1995年 | 55篇 |
1994年 | 44篇 |
1993年 | 37篇 |
1992年 | 34篇 |
1991年 | 34篇 |
1990年 | 20篇 |
1989年 | 35篇 |
1988年 | 14篇 |
1987年 | 15篇 |
1986年 | 25篇 |
1985年 | 21篇 |
1984年 | 27篇 |
1983年 | 27篇 |
1982年 | 23篇 |
1981年 | 20篇 |
1980年 | 19篇 |
1979年 | 21篇 |
1978年 | 14篇 |
1976年 | 9篇 |
1975年 | 8篇 |
1973年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
Quality of life in stroke survivor–caregiver dyads: a new conceptual framework and longitudinal study protocol 下载免费PDF全文
2.
Leonardo Jönck Staub Roberta Rodolfo Mazzali Biscaro Erikson Kaszubowski Rosemeri Maurici 《The Journal of emergency medicine》2019,56(1):53-69
Background
Lung ultrasound can accelerate the diagnosis of life-threatening diseases in adults with respiratory symptoms.Objective
Systematically review the accuracy of lung ultrasonography (LUS) for emergency diagnosis of pneumonia, acute heart failure, and exacerbation of chronic obstructive pulmonary disease (COPD)/asthma in adults.Methods
PubMed, Embase, Scopus, Web of Science, and LILACS (Literatura Latino Americana e do Caribe em Ciências da Saúde; until 2016) were searched for prospective diagnostic accuracy studies. Rutter-Gatsonis hierarchical summary receiver operating characteristic method was used to measure the overall accuracy of LUS and Reitsma bivariate model to measure the accuracy of the different sonographic signs. This review was previously registered in PROSPERO (Centre for Reviews and Dissemination, University of York, York, UK; CRD42016048085).Results
Twenty-five studies were included: 14 assessing pneumonia, 14 assessing acute heart failure, and four assessing exacerbations of COPD/asthma. The area under the summary receiver operating characteristic curve of LUS was 0.948 for pneumonia, 0.914 for acute heart failure, and 0.906 for exacerbations of COPD/asthma. In patients suspected to have pneumonia, consolidation had sensitivity of 0.82 (95% confidence interval [CI] 0.74–0.88) and specificity of 0.94 (95% CI 0.85–0.98) for this disease. In acutely dyspneic patients, modified diffuse interstitial syndrome had sensitivity of 0.90 (95% CI 0.87–0.93) and specificity of 0.93 (95% CI 0.91–0.95) for acute heart failure, whereas B-profile had sensitivity of 0.93 (95% CI 0.72–0.98) and specificity of 0.92 (95% CI 0.79–0.97) for this disease in patients with respiratory failure. In patients with acute dyspnea or respiratory failure, the A-profile without PLAPS (posterior-lateral alveolar pleural syndrome) had sensitivity of 0.78 (95% CI 0.67–0.86) and specificity of 0.94 (95% CI 0.89–0.97) for exacerbations of COPD/asthma.Conclusion
Lung ultrasound is an accurate tool for the emergency diagnosis of pneumonia, acute heart failure, and exacerbations of COPD/asthma. 相似文献3.
D. Sforza G. Iaria L. Petagna A. Parente A. Anselmo F. Sergi S. Marzio F. Corrado S. Telli T.M. Manzia G. Tisone 《Transplantation proceedings》2019,51(1):140-142
Background
One daily dose of tacrolimus (QDT) improves adherence in kidney transplant (KT) recipients. A switch from twice-daily tacrolimus (BDT) to QDT showed similar efficacy and safety.Methods
The aim of our study was to demonstrate the long-term efficacy and safety of switching from BDT to QDT in KT recipients. Preliminary results have already been published. Forty-one patients (34 men and 7 women), mean age at KT of 43.9 ± 12.7 years, underwent a 1:1 dose switch from BDT to QDT; the mean time from KT to switch was 36.6 ± 16.1 months. In our study population, 4 patients received a living donor KT and 2 received a second allograft.Results
The mean follow-up was 86.8 ± 13 months from the switch and 126.2 ± 22.3 months from KT. Graft and patient survival rates were 90.2% and 95.1%, respectively. All patients maintained stable renal function during follow-up. During the first 3 months after the switch we observed a significant decrease in tacrolimus blood level (P = .0001). No significant differences were observed regarding tacrolimus dose before and after QDT introduction (P = not significant [NS]). Fourteen patients who stopped steroids under BDT treatment and 16 patients who stopped steroids after the switch are currently steroid-free.Conclusion
Our study showed safety and efficacy in switching from BDT to QDT. After early (<1 year) dose adjustment, tacrolimus blood levels remained stable throughout follow-up. Moreover, QDT represented a valid alternative for patients showing steroid side effects. 相似文献4.
5.
Background:
The results of a pilot colorectal cancer screening programme by biennial immunochemical faecal occult blood test (FOBT) are reported.Methods:
All residents aged between 50 and 69 years in the Italian province of Lecco were invited to have a FOBT. Those with a positive result were offered colonoscopy. FOBT uptake and compliance with colonoscopy were assessed. Detection rate and positive predictive value (PPV) for cancer and adenoma were calculated. Tumour stages were compared between screen‐detected cancers and other colorectal cancers diagnosed within the target age group.Results:
Some 38 693 (49·6 per cent) of 78 083 individuals had a FOBT and 2392 (6·2 per cent) had a positive result. Colorectal cancer was diagnosed in 4·6 per cent and advanced adenoma in 32·7 per cent. PPVs were 4·0 per cent for cancer, 28·1 per cent for advanced adenoma and 36·6 per cent for any adenoma. There was a significant difference in incidence of stage III/IV disease between screened and non‐screened cohorts. Compliance for colonoscopy was 92·0 per cent. Major determinants of compliance were age less than 59 years, female sex, high education level and non‐manual work.Conclusion:
These results justify extension of colorectal cancer screening to other regions of Italy. Copyright © 2009 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd. 相似文献6.
Khalil Fattouch Giuseppe Bianco Giuseppe Speziale Roberta Sampognaro Carlo Lavalle Francesco Guccione Pietro Dioguardi Giovanni Ruvolo 《European journal of cardio-thoracic surgery》2007,32(2):326-332
BACKGROUND: The inflammatory cascade has been hypothesized to be an important mechanism of post-ischaemic myocardial reperfusion injury and several studies demonstrated that C1 esterase inhibitor (C1-INH) is effective in post-ischaemia myocardial protection. Therefore, we aimed to investigate prospectively in a randomised double-blind study the cardioprotective effects of C1-INH in ST segment elevation myocardial infarction (STEMI) in patients who underwent emergent reperfusion with coronary artery bypass grafting (CABG). METHODS: In this study, we enrolled 80 patients affected with STEMI who underwent emergent CABG. Patients were assigned in two groups (C1-INH group: receive 1000 UI of C1-INH; and placebo group: receive a saline solution). The effects of C1-INH on complement inhibition, myocardial cell injury extension and clinical outcome were studied. Haemodynamic data and myocardial function were monitored. C1-INH, C3a, C4a complement activation fragments and cardiac troponin I (cTnI) serum levels were measured before, during and after surgery. RESULTS: Patient characteristics were not different between the two groups. The overall in-hospital mortality rate was 6.2%. No statistical significant difference was observed between the two groups with regard to early mortality (p=0.36). Statistical significant difference between the two groups was showed for cardiopulmonary bypass support (p=0.04), administration of high dose of inotropes drugs (p=0.001), time of intubation (p=0.03), intensive care unit (ICU) stay (p=0.04) and in-hospital stay (p=0.03). A significant improvement in mean arterial pressure (p=0.03), cardiac index (p=0.02) and stroke volume (p=0.03) was showed in C1-INH group versus placebo group. The serum cTnI levels were significantly low in the C1-INH group versus placebo group after reperfusion, during the observation period. Plasma levels of C3a and C4a complement fragments were reduced significantly in C1-INH group. No drugs-related adverse effects were observed. CONCLUSIONS: The inhibition of the classic complement pathway by C1-INH appears to be an effective mean of preserving ischaemic myocardium from reperfusion injury as demonstrated by low serum cTnI levels in C1-INH group. Therefore, the use of C1-INH during CABG as a rescue therapy in STEMI patients is probably an effective treatment to inhibit complement activity and to improve cardiac function and haemodynamic performance without impacting early mortality. Large randomised study should be performed to support our results. 相似文献
7.
José Abal Arca Isaura Parente Lamelas Raquel Almazán Ortega José Blanco Pérez María Elena Toubes Navarro Pedro Marcos Velázquez 《Archivos de bronconeumologia》2009,45(10):502-507
Background and objectiveTo analyse frequency, characteristics and patient survival with lung cancer (LC) and Common Obstructive Pulmonary Disease (COPD), comparing them with patients that do not have COPD.Material and methodsA retrospective study, of patients diagnosed by means of cytohistology. Survival was estimated by the Kaplan-Meier method. Statistical analysis was carried out using SPSS 15.0.ResultsA total of 996 patients were diagnosed, 39.8% with COPD. Mean age70±9.19 years. GOLD stages: I 18.2%, II 53.6%, III 24%, IV 4.2%. The histological types: squamous cell carcinoma 48.2%, adenocarcinoma 22%, and small cell carcinoma 22.5%. Survival was longer in the COPD group.ConclusionsLC and COPD are combined in 39.8%. Squamous cell type is more frequent and survival was longer in the COPD group. 相似文献
8.
A comparison of the acute inflammatory response in adrenalectomised and sham-operated rats. 总被引:12,自引:8,他引:4 下载免费PDF全文
Carrageenin pleurisy was induced in adrenalectomised (ADX) and sham-operated (SHO) rats. The magnitude and duration of inflammation, as estimated by fluid exudation and cell migration, was greatly increased (approximately doubled) in ADX rats compared with that in their SHO controls. The content of eicosanoids (6-keto-prostaglandin F1 alpha (6-keto-PGF 1 alpha), thromboxane B2 (TXB2), and leukotriene B4 (LTB4] in inflammatory exudates from ADX rats was significantly (2-4 fold) greater than that of their SHO controls. Resident macrophages obtained from ADX rats produced more eicosanoids per cell per unit time when stimulated in vitro with zymosan, than did cells from the SHO controls. Administration of glucocorticoids blocked the inflammatory response and reduced the release of eicosanoids both in vitro and in vivo in both groups of rats. These data are consistent with the notion that physiological amounts of glucocorticoids exert a tonic inhibitory action on phospholipase activity in normal animals and that the increased secretion of these hormones during the inflammatory response serves to check and control the development of inflammation. 相似文献
9.
G. Vacca E. Marano V. Brescia Morra R. Lanzillo M. De Vito E. Parente G. Orefice 《Neurological sciences》2007,28(3):133-135
The prevalence of primary headache (PH) in a multiple sclerosis (MS) sample vs. control healthy subjects was investigated at a neurological clinic in 2004–2005: 122 of 238 (51%) MS patients and 57 of
238 (23%) controls proved to be affected by headache. The groups did not differ for the rates of PH types. Headache types
of MS patients were comparable to those of PH patients that were observed at the same institute in a case-control comparison.
First symptoms of headache preceded those of MS in two thirds of cases. Headache features did not significantly change after
MS onset. Comorbidity of MS and PH could be explained by some common clinical and biological traits. 相似文献
10.
F. M. O. Silva J. E. Vergara‐Parente J. K. N. Gomes M. N. Teixeira R. P. Lima 《Transboundary and Emerging Diseases》2007,54(3):119-122
Serum chemistry analyses represents a fundamental tool for the diagnosis and understanding of diseases in marine mammals. Although several studies are being conducted within the field of clinical pathology, haematological and serum chemistry data for Antillean manatees are deficient. The purpose of this study was to determine serum chemistry values for captive Antillean manatees within the CMA/Ibama facility in Brazil. Serum samples were obtained from five captive adult Antillean manatees fed with seagrass and analysed for aspartate aminotransferase, alanine aminotransferase, bilirubin, alkaline phosphatase, urea, creatinine, glucose, triglycerides, cholesterol, total protein, albumin, globulin, phosphate, chloride, calcium and uric acid. Blood chemistry parameters were determined using a semi‐automatic analyzer. Maximum, minimum, mean and standard deviations were calculated for each serum chemistry parameter. Differences on the values of males and females were verified using an unpaired Student's t‐test. All the parameters analysed were similar between sexes, with exception of AP, which was higher in females (191.43 ± 31.86 U/l). Alanine aminotransferase and uric acid values for Trichechus manatus manatus are reported for the first time in this paper. This study is the first to report serum chemistry parameter values for long‐term captive male and female Antillean manatees. Therefore, the lower values of albumin, phosphate, chloride, cholesterol and triglycerides obtained here highlight the importance of clinical pathology during health monitoring of captive marine mammals. 相似文献