全文获取类型
收费全文 | 344篇 |
免费 | 28篇 |
专业分类
儿科学 | 9篇 |
妇产科学 | 2篇 |
基础医学 | 72篇 |
口腔科学 | 8篇 |
临床医学 | 24篇 |
内科学 | 127篇 |
皮肤病学 | 13篇 |
神经病学 | 10篇 |
特种医学 | 5篇 |
外科学 | 27篇 |
综合类 | 5篇 |
预防医学 | 22篇 |
眼科学 | 4篇 |
药学 | 24篇 |
肿瘤学 | 20篇 |
出版年
2023年 | 9篇 |
2022年 | 7篇 |
2021年 | 13篇 |
2020年 | 8篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 10篇 |
2016年 | 3篇 |
2015年 | 7篇 |
2014年 | 14篇 |
2013年 | 16篇 |
2012年 | 27篇 |
2011年 | 14篇 |
2010年 | 15篇 |
2009年 | 9篇 |
2008年 | 12篇 |
2007年 | 11篇 |
2006年 | 10篇 |
2005年 | 12篇 |
2004年 | 7篇 |
2003年 | 6篇 |
2002年 | 11篇 |
2001年 | 6篇 |
2000年 | 10篇 |
1999年 | 10篇 |
1998年 | 2篇 |
1997年 | 4篇 |
1993年 | 3篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1990年 | 9篇 |
1989年 | 7篇 |
1988年 | 8篇 |
1986年 | 5篇 |
1985年 | 11篇 |
1984年 | 11篇 |
1983年 | 4篇 |
1981年 | 7篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1976年 | 2篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1969年 | 2篇 |
1968年 | 3篇 |
1967年 | 4篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有372条查询结果,搜索用时 15 毫秒
1.
Randomized placebo-controlled study of low-dose warfarin for the prevention of central venous catheter-associated thrombosis in patients with cancer. 总被引:13,自引:0,他引:13
Stephen Couban Michael Goodyear Margot Burnell Sean Dolan Parveen Wasi David Barnes Darlene Macleod Erica Burton Pantelis Andreou David R Anderson 《Journal of clinical oncology》2005,23(18):4063-4069
PURPOSE: In this multicenter, randomized, placebo-controlled clinical trial, we studied whether warfarin 1 mg daily reduces the incidence of symptomatic central venous catheter (CVC) -associated thrombosis in patients with cancer. PATIENTS AND METHODS: Two hundred fifty-five patients with cancer who required a CVC for at least 7 days were randomly assigned to receive warfarin 1 mg or placebo. RESULTS: There were 11 (4.3%) symptomatic CVC-associated thromboses among 255 patients, with no difference in the incidence of symptomatic CVC-associated thrombosis between patients taking warfarin 1 mg daily (six of 130 patients; 4.6%) and patients taking placebo (five of 125 patients; 4.0%; hazard ratio, 1.20; 95% CI, 0.37 to 3.94). Warfarin had no effect on CVC life span (84 days v 63 days in control and warfarin groups, respectively; 95% confidence limit, -16 to 55 days; P = .09), and it did not affect the number of premature CVC removals (23.2% v 25.4% in control and warfarin groups, respectively; 95% confidence limit of difference -8.34 to 12.71; P = .68) or the frequency of major bleeding episodes (2% v 0% in control and warfarin groups, respectively; P = .5, Fisher's exact test). CONCLUSION: Symptomatic CVC-associated thrombosis in patients with cancer, although significant, is less common than previously reported. In this study, the administration of warfarin 1 mg daily did not reduce the incidence of symptomatic CVC-associated thrombosis in patients with cancer. However, the low rate of symptomatic CVC-associated thrombosis means that a much larger trial is required to address this issue definitively. 相似文献
2.
3.
Zsfia Lanszki Jzsef Lanszki Gbor Endre Tth Safia Zeghbib Ferenc Jakab Gbor Kemenesi 《Viruses》2022,14(7)
The Eurasian otter (Lutra lutra) is a piscivorous apex predator in aquatic habitats, and a flagship species of conservation biology throughout Europe. Despite the wide distribution and ecological relevance of the species, there is a considerable lack of knowledge regarding its virological and veterinary health context, especially in Central Europe. Canine morbillivirus (Canine distemper virus (CDV)) is a highly contagious viral agent of the family Paramyxoviridae with high epizootic potential and veterinary health impact. CDV is present worldwide among a wide range of animals; wild carnivores are at particular risk. As part of a retrospective study, lung-tissue samples (n = 339) from Eurasian otters were collected between 2000 and 2021 throughout Hungary. The samples were screened for CDV using a real-time RT-PCR method. Two specimens proved positive for CDV RNA. In one sample, the complete viral genome was sequenced using a novel, pan-genotype CDV-specific amplicon-based sequencing method with Oxford Nanopore sequencing technology. Both viral sequences were grouped to a European lineage based on the hemagglutinin-gene phylogenetic classification. In this article, we present the feasibility of road-killed animal samples for understanding the long-term dynamics of CDV among wildlife and provide novel virological sequence data to better understand CDV circulation and evolution. 相似文献
4.
Zainab Samad Ali Aahil Noorali Awais Farhad Safia Awan Nada Qaiser Qureshi Minaz Mawani Mushyada Ali Laiba Masood Ghufran Adnan Linda K. Shaw Fahim Haider Jafary Salim S. Virani Eric J. Velazquez Zulfiqar Bhutta Gerald S. Bloomfield Javed Tai 《Global Heart》2022,17(1)
Background and Objective:Few data exist on trends in acute myocardial infarction (AMI) patterns spanning recent epidemiological shifts in low middle-income countries (LMICs). To understand temporal disease patterns of AMI characteristics and outcomes between 1988–2018, we used digitized legacy clinical data at a large tertiary care centre in Pakistan.Methods:We reviewed digital health information capture systems maintained across the Aga Khan University Hospital and obtained structured elements to create a master dataset. We included index admissions of patients >18 years that were discharged between January 1, 1988, and December 31, 2018, with a primary discharge diagnosis of AMI (using ICD-9 diagnoses). The outcome evaluated was in-hospital mortality.Clinical characteristics derived from the electronic database were validated against chart review in a random sample of cases (k 0.53–1.00).Results:The final population consisted of 14,601 patients of which 30.6% (n = 4,470) were female, 52.4% (n = 7,651) had ST elevation MI and 47.6% (n = 6,950) had non-ST elevation MI. The median (IQR) age at presentation was 61 (52–70) years. Overall unadjusted in-hospital mortality was 10.3%. Across the time period, increasing trends were noted for the following characteristics: age, proportion of women, prevalence of hypertension, diabetes, proportion with NSTEMI (all ptrend < 0.001). In-hospital mortality rates declined significantly between 1988–1997 and 2008–2018 (13.8% to 9.2%, p < 0.001).Conclusions:The patterns of AMI have changed over the last three decades with a concomitant decline in in-hospital mortality at a tertiary care centre in Pakistan. Clinical digitized data presents a unique opportunity for gaining insights into disease patterns in LMICs. 相似文献
5.
Ibrahim bin Jantan Mira Febrina Yalvema Nazni Wasi Ahmad Jamia Azdina Jamal 《Pharmaceutical biology》2013,51(6):526-532
AbstractThe leaf oils of eight Cinnamomum. species (C. rhyncophyllum. Miq., C. microphyllum. Ridl., C. pubescens. Kochummen, C. mollissimum. Hook. f., C. impressicostatum. Kosterm, C. scortechinii. Gamb., C. sintoc. Bl., and C. cordatum. Kosterm) were investigated for their larvicidal and adulticidal activities against Aedes aegypti. (Aedes aegypti Lynn) and Aedes albopictus. (Aedes albopictus Skuse). Acute mortalities of the fourth instar larvae and the adult mosquitoes were determined according to the standard WHO methods. Among the essential oils studied, the leaf oils of C. rhyncophyllum., C. microphyllum., C. pubescens., C. mollissimum., and C. impressicostatum. showed significant effects against the larvae of Ae. aegypti. and Ae. albopictus. with concentrations that caused 50% mortality (LC50) values of less than 12.8 and 11.8 µg ml?1, respectively. The essential oils that showed strong larvicidal effects also demonstrated relatively strong adulticidal effects on the mosquitoes after 3 h exposure with LC50 values ranging from 133.0 to 243.0 µg ml?1 against Ae. aegypti. and from 118.0 to 194.0 µg ml?1 against Ae. albopictus.. The efficacy of the oils toward the larvae and adult mosquitoes of both species was nonselective as the LC50 values showed little variation. The chemical composition of the oils was investigated by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). This study suggested that the essential oils containing high levels of benzyl benzoate and benzyl salicylate exhibited strong insecticidal activities against the larvae and adult mosquitoes. 相似文献
6.
Ultrastructure and cell cycle distribution of erythropoietic cells in heterozygotes and homozygotes for haemoglobin E 总被引:1,自引:0,他引:1
S N Wickramasinghe M Hughes P Wasi S Fucharoen R A Litwinczuk 《British journal of haematology》1984,57(4):685-694
S ummary. Marrow aspirates from heterozygotes and homozygotes for haemoglobin E (HbE) have been studied by electron microscopy and by the technique of combined Feulgen microspectrophotometry and 3 H-thymidine autoradiography. The erythropoietic cells of heterozygotes did not contain any precipitated globin chains and the proliferating erythroblasts of such individuals showed no abnormality in their distribution in the different stages of interphase. By contrast, 0–1.5% of late erythroblast profiles and 3.1–12.8% of marrow reticulocyte profiles of homozygotes contained intracellular inclusions resembling precipitated α-chains. Although precipitated globin chains were not seen in the early polychromatic erythroblasts of homozygotes, the number of these cells in the G2 phase relative to that in the S phase was increased. These data indicate that there is (1) probably little or no imbalance of globin chain synthesis in heterozygotes, (2) a substantial degree of imbalance in homozygotes, and (3) a disturbance of erythroblast proliferation in homozygotes which cannot be attributed to the deleterious effects of detectable intracellular α-chain precipitates. The electron microscope and cell cycle distribution data in the homozygotes for HbE were similar to those in two heterozygotes for β thalassaemia. 相似文献
7.
8.
Incidence and risk factors for pulmonary tuberculosis among the poor in the northern region of Poland 总被引:1,自引:0,他引:1
J Romaszko A Buciński R Wasiński A Ros?an K Bednarski 《The international journal of tuberculosis and lung disease》2008,12(4):430-435
SETTING: The falling trends in pulmonary tuberculosis (PTB) incidence observed in European countries may be due both to an improving epidemiological situation and to a shift of tuberculosis (TB) towards socially important subpopulations; this trend may cause some TB cases to go unnoticed. Identification of such risk groups should be the basis for prevention programmes aimed at containing the spread of the disease. OBJECTIVE: To evaluate the incidence and risk factors for PTB among the poor. DESIGN: The study material was based on the data of 7380 people living in poverty, including 243 homeless adults, aged between 18 and 96 years. Potential medical and socio-economic risk factors were evaluated with regard to PTB incidence. RESULTS: The TB incidence rate in the group studied was estimated at 730 per 100,000 population. The main risk factor was homelessness, with a TB incidence rate in the homeless group of 4290/100,000. According to our data, socio-economic factors correlated much more closely with a final TB diagnosis than subjective disease symptoms. CONCLUSIONS: Efficient TB control requires prevention programmes aimed at systematic monitoring of the homeless. A population with such a high proportion of TB patients is a dangerous source of TB. 相似文献
9.
Abd A. Tahrani Kiran Dubb Neil T. Raymond Safia Begum Quratul A. Altaf Hamed Sadiqi Milan K. Piya Martin J. Stevens 《Diabetologia》2014,57(6):1249-1256
Aims/hypothesis
The aim of this work was to assess the impact of cardiac autonomic neuropathy (CAN) on the development and progression of chronic kidney disease (CKD) in patients with type 2 diabetes.Methods
We conducted a cohort study in adults with type 2 diabetes. Patients with end-stage renal disease were excluded. CKD was defined as the presence of albuminuria (albumin/creatinine ratio GFR >?3.4 mg/mmol) or an estimated (eGFR) <?60 ml min?1 1.73 m?2. CKD progression was based on repeated eGFR measurements and/or the development of albuminuria. CAN was assessed using heart rate variability.Results
Two hundred and four patients were included in the analysis. At baseline, the prevalence of CKD and CAN was 40% and 42%, respectively. Patients with CAN had lower eGFR and higher prevalence of albuminuria and CKD. Spectral analysis variables were independently associated with eGFR, albuminuria and CKD at baseline. After a follow-up of 2.5 years, eGFR declined to a greater extent in patients with CAN than in those without CAN (?9.0?±?17.8% vs ?3.3?±?10.3%, p?=?0.009). After adjustment for baseline eGFR and baseline differences, CAN remained an independent predictor of eGFR decline over the follow-up period (β?=??3.5, p?=?0.03). Spectral analysis variables were also independent predictors of eGFR decline.Conclusions/interpretation
CAN was independently associated with CKD, albuminuria and eGFR in patients with type 2 diabetes. In addition, CAN was an independent predictor of the decline in eGFR over the follow-up period. CAN could be used to identify patients with type 2 diabetes who are at increased risk of rapid decline in eGFR, so that preventative therapies might be intensified. 相似文献10.
Tahrani AA Ali A Raymond NT Begum S Dubb K Mughal S Jose B Piya MK Barnett AH Stevens MJ 《American journal of respiratory and critical care medicine》2012,186(5):434-441
Rationale: Diabetic peripheral neuropathy is common and causes significant morbidity. Obstructive sleep apnea (OSA) is also common in patients with type 2 diabetes. Because OSA is associated with inflammation and oxidative stress, we hypothesized that OSA is associated with peripheral neuropathy in type 2 diabetes. Objectives: To assess the relationship between OSA and peripheral neuropathy in patients with type 2 diabetes. Methods: A cross-sectional study of adults with type 2 diabetes recruited randomly from the diabetes clinic of two UK hospitals. Measurements and Main Results: Peripheral neuropathy was diagnosed using the Michigan Neuropathy Screening Instrument. OSA (apnea-hypopnea index ≥ 5 events/h) was assessed using home-based, multichannel respiratory monitoring. Serum nitrotyrosine was measured by ELISA, lipid peroxide by spectrophotometer, and microvascular function by laser speckle contrast imaging. Two hundred thirty-four patients (mean [SD] age, 57 [12] yr) were analyzed. OSA prevalence was 65% (median apnea-hypopnea index, 7.2; range, 0-93), 40% of which were moderate to severe. Neuropathy prevalence was higher in patients with OSA than those without (60% vs. 27%, P < 0.001). After adjustment for possible confounders, OSA remained independently associated with diabetic neuropathy (odds ratio, 2.82; 95% confidence interval, 1.44-5.52; P = 0.0034). Nitrotyrosine and lipid peroxide levels (n = 102, 74 with OSA) were higher in OSA and correlated with hypoxemia severity. Cutaneous microvascular function (n = 71, 47 with OSA) was impaired in OSA. Conclusions: We describe a novel independent association between diabetic peripheral neuropathy and OSA. We identified increased nitrosative/oxidative stress and impaired microvascular regulation as potential mechanisms. Prospective and interventional studies are needed to assess the impact of OSA and its treatment on peripheral neuropathy development and progression in patients with type 2 diabetes. 相似文献