全文获取类型
收费全文 | 6016篇 |
免费 | 417篇 |
国内免费 | 51篇 |
专业分类
耳鼻咽喉 | 41篇 |
儿科学 | 132篇 |
妇产科学 | 135篇 |
基础医学 | 1100篇 |
口腔科学 | 99篇 |
临床医学 | 519篇 |
内科学 | 1550篇 |
皮肤病学 | 180篇 |
神经病学 | 598篇 |
特种医学 | 85篇 |
外科学 | 570篇 |
综合类 | 26篇 |
一般理论 | 3篇 |
预防医学 | 453篇 |
眼科学 | 82篇 |
药学 | 463篇 |
中国医学 | 21篇 |
肿瘤学 | 427篇 |
出版年
2024年 | 10篇 |
2023年 | 107篇 |
2022年 | 272篇 |
2021年 | 405篇 |
2020年 | 192篇 |
2019年 | 265篇 |
2018年 | 286篇 |
2017年 | 183篇 |
2016年 | 224篇 |
2015年 | 225篇 |
2014年 | 307篇 |
2013年 | 346篇 |
2012年 | 492篇 |
2011年 | 519篇 |
2010年 | 271篇 |
2009年 | 231篇 |
2008年 | 362篇 |
2007年 | 353篇 |
2006年 | 311篇 |
2005年 | 298篇 |
2004年 | 236篇 |
2003年 | 212篇 |
2002年 | 197篇 |
2001年 | 20篇 |
2000年 | 8篇 |
1999年 | 33篇 |
1998年 | 28篇 |
1997年 | 22篇 |
1996年 | 13篇 |
1995年 | 10篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1988年 | 1篇 |
1987年 | 4篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1963年 | 1篇 |
1931年 | 1篇 |
1928年 | 1篇 |
排序方式: 共有6484条查询结果,搜索用时 11 毫秒
101.
Clinical characteristics and long-term outcome in patients with heart failure complicating acute myocardial infarction 总被引:1,自引:0,他引:1
Macín SM Perna ER Augier N Cialzeta J Farías EF Fontana M Agüero M Badaracco JR 《Revista espa?ola de cardiología》2005,58(7):789-796
INTRODUCTION AND OBJECTIVES: To evaluate the clinical characteristics and prognosis of heart failure (HF) development in patients hospitalized for acute myocardial infarction (AMI). PATIENTS AND METHOD: Between May 1990 and March 2000, 836 consecutive patients were admitted with a diagnosis of AMI within 24 h of symptom onset. HF was defined as the presence of rales and a third heart sound with gallop, and evidence of pulmonary congestion on chest x-ray. It was diagnosed in 263 subjects (31.5%). RESULTS: The mean age of patients with HF (group 1) was 63.4 (11.4) years compared with 59.9 (11.6) years in those without HF (group 2) (P<.01). There were differences between groups 1 and 2 in history of diabetes (36% vs 20%; P<.001) or previous HF (9.2% vs 1.1%; P<.001). The reperfusion strategy used in patients with Q-wave infarction, with or without HF, was primary angioplasty in 15% and 14%, respectively (P=.81), and thrombolytic agents in 28% and 37%, respectively (P=.013). Patients with HF were more likely to develop recurrent angina (26.8% vs 19.6%; P=.02), pericarditis (17.5% vs 6.3%; P<.001), and atrial fibrillation (12.3% vs 5.1%; P<.01). In-hospital mortality in groups 1 and 2 was 15.6% and 2.3% (P<.001), respectively, and 10-year survival was 10% and 30%, respectively (P<.001). The variables associated with mortality were: age (HR=1.022; P<.001), hyperglycemia (HR=1.748 per 1.0-g/L increase; P<.001), leukocytosis (HR=1.035 per 1000-cell/.L increase; P<.001), and HF (HR=1.308; P=.028). CONCLUSIONS: AMI is still frequently complicated by HF, which increases short- and long-term morbidity and mortality. Heart failure, age, hyperglycemia, and leukocytosis at admission were independent predictors of mortality during follow-up. 相似文献
102.
Lundberg K Kinloch A Fisher BA Wegner N Wait R Charles P Mikuls TR Venables PJ 《Arthritis and rheumatism》2008,58(10):3009-3019
OBJECTIVE: To map the antibody response to human citrullinated alpha-enolase, a candidate autoantigen in rheumatoid arthritis (RA), and to examine cross-reactivity with bacterial enolase. METHODS: Serum samples obtained from patients with RA, disease control subjects, and healthy control subjects were tested by enzyme-linked immunosorbent assay (ELISA) for reactivity with citrullinated alpha-enolase peptides. Antibodies specific for the immunodominant epitope were raised in rabbits or were purified from RA sera. Cross-reactivity with other citrullinated epitopes was investigated by inhibition ELISAs, and cross-reactivity with bacterial enolase was investigated by immunoblotting. RESULTS: An immunodominant peptide, citrullinated alpha-enolase peptide 1, was identified. Antibodies to this epitope were observed in 37-62% of sera obtained from patients with RA, 3% of sera obtained from disease control subjects, and 2% of sera obtained from healthy control subjects. Binding was inhibited with homologous peptide but not with the arginine-containing control peptide or with 4 citrullinated peptides from elsewhere on the molecule, indicating that antibody binding was dependent on both citrulline and flanking amino acids. The immunodominant peptide showed 82% homology with enolase from Porphyromonas gingivalis, and the levels of antibodies to citrullinated alpha-enolase peptide 1 correlated with the levels of antibodies to the bacterial peptide (r2=0.803, P<0.0001). Affinity-purified antibodies to the human peptide cross-reacted with citrullinated recombinant P gingivalis enolase. CONCLUSION: We have identified an immunodominant epitope in citrullinated alpha-enolase, to which antibodies are specific for RA. Our data on sequence similarity and cross-reactivity with bacterial enolase may indicate a role for bacterial infection, particularly with P gingivalis, in priming autoimmunity in a subset of patients with RA. 相似文献
103.
Pozzilli P Crinò A Schiaffini R Manfrini S Fioriti E Coppolino G Pitocco D Visalli N Corbi S Spera S Suraci C Cervoni M Matteoli MC Patera IP Ghirlanda G;IMDIAB Group 《Diabetes technology & therapeutics》2003,5(6):965-974
In a pilot study, the metabolic effects of continuous subcutaneous insulin infusion (CSII) versus intensive subcutaneous insulin therapy (ISIT) started at diagnosis in patients with Type 1 diabetes and continued for a 2-year period were evaluated and compared. Twenty-three patients (between 12 and 35 years old, mean +/- SD 18.4 +/- 9 years) were randomized into two treatment groups (CSII vs. ISIT), and both received supplemental nicotinamide (NA), 25 mg/kg of body weight. CSII was started immediately after admission to the hospital. Parameters of metabolic control [insulin dose, hemoglobin A1c (HbA1c), and C-peptide] were evaluated for a 2-year follow-up period. Data are presented for a total of 19 patients who remained in the study for its duration. Two years after diagnosis, mean +/- SD HbA1c was 6.3 +/- 0.5% and 6.2 +/- 0.3% for the CSII and ISIT groups, respectively (p=not significant). Compared with baseline values, an increase of baseline C-peptide of 38% for the CSII group and 27% for the ISIT group was observed; however, the difference between the groups was not significant. The insulin requirement for the entire duration of the study, but not at entry and 3 months, was significantly higher in CSII compared with ISIT patients (0.62 +/- 0.4 IU/kg/day vs. 0.3 +/- 0.4 IU/kg/day, respectively; p<0.01). After trial completion patients on CSII continued with this mode of therapy. Implementation of CSII as well as ISIT at diagnosis of Type 1 diabetes and continuation for 2 years thereafter achieved similar and optimal metabolic control, but more insulin was required with the CSII group. Both types of intensive insulin therapy combined with NA are able to preserve C-peptide secretion or even increase baseline levels for up to 2 years after diagnosis. 相似文献
104.
Energetics and Mechanism of Conformational Transitions of Protein‐Like NIPAM‐Sodium Styrene Sulfonate Copolymers in Aqueous Solutions 下载免费PDF全文
Valerij Y. Grinberg Tatiana V. Burova Natalia V. Grinberg Alexander S. Dubovik Irina G. Plaschina Tatiana V. Laptinskaya Yubing Xiong Ping Yao Alexei R. Khokhlov 《Macromolecular chemistry and physics.》2015,216(24):2344-2355
Protein‐like and random NIPAM‐sodium styrene sulfonate copolymers of similar composition have been prepared by radical polymerization in water at temperatures above and below the LCST of PNIPAM, respectively. Thermal transitions of the copolymers in aqueous solutions have been studied by means of dynamic light scattering, viscometry, and high‐sensitivity differential scanning calorimetry. The phase separation or cooperative conformational transitions without phase separation were observed for the random or the protein‐like copolymers, respectively. Transition temperature, enthalpy, and heat capacity increment of the protein‐like copolymer differed insignificantly from those of the random copolymer of similar composition. The transition heat capacity increments of the protein‐like copolymers revealed that only 10–20% of their NIPAM links participate in the formation of a dense water‐free globule core. The coil–globule transitions of the protein‐like copolymers were described by the thermodynamic three‐state model according to the scheme “random coil?condensed coil?globule”, which is known to simulate the folding mechanism of globular proteins.
105.
Maciej Cabanski Brett Fields Stephanie Boue Natalia Boukharov Hector DeLeon Natalie Dror Marcel Geertz Emmanuel Guedj Anita Iskandar Ulrike Kogel Celine Merg Michael J. Peck Carine Poussin Walter K. Schlage Marja Talikka Nikolai V. Ivanov Julia Hoeng Manuel C. Peitsch 《Inflammation research》2015,64(7):471-486
106.
M. de los Ángeles Leal-Felipe M. del Carmen Arroyo-López M. del Cristo Robayna-Delgado Ana Gómez-Espejo Patricia Perera-Díaz Carmen D. Chinea-Rodríguez Natalia García-Correa Alejandro Jiménez-Sosa 《Australian critical care》2018,31(6):355-361
Background
Hospital-acquired pressure injuries are a costly and largely preventable complication occurring in a variety of acute care settings. Patients admitted to the intensive care unit are at greater risk of developing pressure injuries.Objective
To determine whether the efficiency of scales to measure pressure injury risk increase when a continuously updated 3-day moving average method is used.Methods
With a retrospective cohort design we recruited 3085 patients treated between June 2011 and February 2015 in the intensive care unit of a tertiary level university hospital.The present study included 2777 patients admitted to the Intensive Care Unit of the Hospital Universitario de Canarias, Spain.Patients were evaluated daily with two scales to measure pressure injury risk: the Current Risk Assessment Scale for Pressure injury in Intensive Care scale (EVARUCI scale) and the Conscious level-Mobility-Haemodynamics-Oxygenation-Nutrition Index (COMHON). The moving average was used to create a series of three day averages from the complete time-data set. The moving average method was used to analyze data points by creating series of averages of three days subsets of the time-data set. We calculated the efficiency of the method as the product of positive (PPV) and negative predicted values (NPV) for each scale.Results
The efficiency using the moving average method was: PPV x NPV = 0.483 × 0.907 = 0.438 (standard deviation = 0.059), for EVARUCI Scale, and. PPV x NPV = 0.552 × 0.806 = 0.445 (standard deviation = 0.075) for COMHON Index.Conclusions
The efficiency using the moving average method was higher, than the efficiency of other methods previously reported (0.360 ± 0.009 on average). The present study provides a useful procedure for nurses in clinical practice to assess whether a particular patient is protected against the appearance of pressure injury. The instrument should be used focusing on negative predictive value to indicate protection against pressure injury. 相似文献107.
Sanhita Sinharay Edward A. Randtke Christine M. Howison Natalia A. Ignatenko Mark D. Pagel 《Molecular imaging and biology》2018,20(2):240-248
Purpose
The detection of enzyme activities and evaluation of enzyme inhibitors have been challenging with magnetic resonance imaging (MRI). To address this need, we have developed a diamagnetic, nonmetallic contrast agent and a protocol known as catalyCEST MRI that uses chemical exchange saturation transfer (CEST) to detect enzyme activity as well as enzyme inhibition.Procedures
We synthesized a diamagnetic MRI contrast agent that has enzyme responsive and enzyme unresponsive CEST signals. We tested the ability of this agent to detect the activity of kallikrein 6 (KLK6) in biochemical solutions, in vitro and in vivo, with and without a KLK6 inhibitor.Results
The agent detected KLK6 activity in solution and also detected KLK6 inhibition by antithrombin III. KLK6 activity was detected during in vitro studies with HCT116 colon cancer cells, relative to the detection of almost no activity in a KLK6-knockdown HCT116 cell line and HCT116 cells treated with antithrombin III inhibitor. Finally, strong enzyme activity was detected within an in vivo HCT116 tumor model, while lower enzyme activity was detected in a KLK6 knockdown tumor model and in the HCT116 tumor model treated with antithrombin III inhibitor. In all cases, comparisons of the enzyme responsive and enzyme unresponsive CEST signals were critical for the detection of enzyme activity.Conclusions
This study has established that catalyCEST MRI with an exogenous diaCEST agent can evaluate enzyme activity and inhibition in solution, in vitro and in vivo.108.
Mattia Morri Paolo Chiari Cristiana Forni Antonella Orlandi Magli Domenica Gazineo Natalia Franchini Lorenzo Marconato Tiziana Giamboi Andrea Cotti 《Archives of physical medicine and rehabilitation》2018,99(5):893-899
Objective
To identify the factors associated with recovering autonomy in activities of daily living (ADL) in patients who have had a hip fracture.Design
A prospective cohort study.Setting
The orthopedic and orthogeriatric departments of 2 regional hospitals.Participants
Patients (N=742) aged ≥65 years with a diagnosis of fragility hip fracture.Main Outcome Measures
The level of autonomy at 4 months was assessed using the ADL scale.Results
The median score on the ADL scale at 4 months was 3 (interquartile range, 5). Half of the population was unable to recover their prefracture autonomy levels. The following were found to be risk factors: increasing age (B=.02, P<.001); an elevated number of comorbidities (B=.044, P=.005); a lower level of prefracture autonomy (B=.087, P<.001); more frequent use of an antidecubitus mattress (B=.211, P<.001); an increased number of days with disorientation (B=.002, P=.012); failure to recover deambulation (B=.199, P<.001); an increased number of days with diapers (B=.003, P<.001), with a urinary catheter (B=.03, P<.001), and with bed rails (B=.001, P=.014); and a nonintensive care pathway (B=.199, P=.014).Conclusions
Recovery of deambulation, treatment of disorientation and management of incontinence are modifiable factors significantly associated with the functional recovery of autonomy. 相似文献109.
110.
Olga Ivanitskaya MD PhD Elena Andreeva MD PhD Natalia Odegova MD 《Journal of ultrasound in medicine》2018,37(4):1039-1042
A ventricular septal aneurysm is a rare heart defect located in the muscular or membranous part of the septum. Muscular ventricular septal aneurysms are usually isolated, with a favorable prognosis. Membranous ventricular septal aneurysms are often associated with other heart anomalies, could result in serious complications, and may require surgical treatment. We describe 2 cases of prenatally diagnosed ventricular septal aneurysms: an isolated membranous ventricular septal aneurysm with a good outcome, which was initially misdiagnosed as an atrioventricular septal defect; and a muscular ventricular septal aneurysm associated with a hypoplastic aortic arch and severe hydrocephaly, which resulted in termination of the pregnancy. To our knowledge, the combination of a muscular ventricular septal aneurysm with an extracardiac anomaly has not been reported previously. 相似文献