全文获取类型
收费全文 | 124429篇 |
免费 | 11517篇 |
国内免费 | 7297篇 |
专业分类
耳鼻咽喉 | 1343篇 |
儿科学 | 1828篇 |
妇产科学 | 1661篇 |
基础医学 | 13231篇 |
口腔科学 | 2023篇 |
临床医学 | 14988篇 |
内科学 | 19370篇 |
皮肤病学 | 1372篇 |
神经病学 | 6566篇 |
特种医学 | 4481篇 |
外国民族医学 | 51篇 |
外科学 | 14171篇 |
综合类 | 19659篇 |
现状与发展 | 30篇 |
一般理论 | 24篇 |
预防医学 | 10001篇 |
眼科学 | 3089篇 |
药学 | 12564篇 |
100篇 | |
中国医学 | 6960篇 |
肿瘤学 | 9731篇 |
出版年
2024年 | 415篇 |
2023年 | 1545篇 |
2022年 | 3975篇 |
2021年 | 5379篇 |
2020年 | 4183篇 |
2019年 | 3675篇 |
2018年 | 3947篇 |
2017年 | 3846篇 |
2016年 | 3478篇 |
2015年 | 5276篇 |
2014年 | 6701篇 |
2013年 | 6678篇 |
2012年 | 9679篇 |
2011年 | 10231篇 |
2010年 | 7039篇 |
2009年 | 5902篇 |
2008年 | 7256篇 |
2007年 | 7242篇 |
2006年 | 6862篇 |
2005年 | 6399篇 |
2004年 | 5140篇 |
2003年 | 5045篇 |
2002年 | 4400篇 |
2001年 | 3021篇 |
2000年 | 2474篇 |
1999年 | 2201篇 |
1998年 | 1369篇 |
1997年 | 1279篇 |
1996年 | 960篇 |
1995年 | 906篇 |
1994年 | 743篇 |
1993年 | 540篇 |
1992年 | 718篇 |
1991年 | 647篇 |
1990年 | 506篇 |
1989年 | 427篇 |
1988年 | 408篇 |
1987年 | 360篇 |
1986年 | 309篇 |
1985年 | 250篇 |
1984年 | 215篇 |
1983年 | 198篇 |
1982年 | 165篇 |
1981年 | 166篇 |
1980年 | 138篇 |
1979年 | 148篇 |
1978年 | 100篇 |
1977年 | 82篇 |
1976年 | 82篇 |
1973年 | 73篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
D Johnstone M Limacher M Rousseau C S Liang L Ekelund M Herman D Stewart M Guillotte G Bjerken W Gaasch 《The American journal of cardiology》1992,70(9):894-900
The Studies of Left Ventricular Dysfunction (SOLVD) trials were designed to evaluate the effects of enalapril on long-term mortality in patients with severe left ventricular (LV) dysfunction. Patients with LV ejection fractions less than or equal to 0.35 and symptoms of congestive heart failure (CHF) were enrolled in the treatment trial, whereas those with no history of overt CHF and taking no treatment directed for LV dysfunction were enrolled in the prevention trial. The baseline clinical characteristics of SOLVD patients were compared to characterize differences between patients in these 2 separate but concurrent trials. From over 70,000 patients screened with LV dysfunction, 4,228 patients were enrolled in the prevention trial and 2,569 patients in the treatment trial. Ischemic heart disease was the primary cause of LV dysfunction in both prevention (83%) and treatment (71%) trial patients. Prior myocardial infarction was present in 80% of the prevention and 66% of the treatment trial patients (p less than 0.001). In the prevention trial, infarction was recent (less than or equal to 6 months) in 27% patients and remote (greater than 6 months) in 57% patients. Treatment trial patients had proportionately more women (20 vs 13%; p less than 0.001) and non-Caucasians (20 vs 14%; p less than 0.001), as well as the coexisting risk factors of hypertension (42 vs 37%; p less than 0.001) and diabetes (26 vs 15%; p less than 0.001) than did prevention trial patients. Clinical characteristics of patients in both trials were influenced by the gender and race of enrolled patients. Similarly, coronary artery bypass surgery was performed less often in women and non-Caucasians.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
52.
53.
Wen Zhao Jian Sun Jia-Wei Zheng Jun Li Yue He Zhi-Yuan Zhang 《Otolaryngology--head and neck surgery》2006,135(5):758-764
OBJECTIVE: To study the effect of the cervical plexus and the accessory nerve to the function of the trapezius muscle. STUDY DESIGN AND SETTING: Eighteen adult male Sprague-Dawley rats were randomly divided into three groups. The neurotomies were performed in the left sides and the right sides served as within-subject controls. In group A, the accessory nerve was transected. The C2-5 were transected in group B, and both of the accessory nerve and C2-5 were cut in group C. The electrophysiologic, myophysiologic, and histologic changes of the muscles were measured. RESULTS: There were significant differences (P < 0.05) between the three groups in the recovery rates of the transverse area of the muscles. The CMAP recorded from the experimental sides in group B were similar to the control sides. The values of the maximum tension of the tetanus contraction between the two sides showed no differences either (P > 0.05). CONCLUSION: The accessory nerve supplies the most important motor input to the trapezius. Motor innervations of the cervical plexus are not very significant. 相似文献
54.
55.
目的探讨胃黏膜内pH值对胆源性胰腺炎病情预后评估及在决定手术冶疗中应用的价值。方法对确诊的146例胆源性胰腺炎患者经鼻插入胃黏膜二氧化碳张力计(TRIP-NGS导管)测定胃黏膜内pH值,每隔12小时测定一次,并进行APACHEⅡ评分,将2组数据与外科治疗进行相关分析。结果①pH值变化反映胆源性胰腺炎病情发展变化,与器官衰竭数呈负相关;②外科干预治疗与内科治疗比较差异有统计学意义(P〈0.05);③pHI〉7.25与pH〈7.25患者开腹手术病死率和细菌培养阳性率比较差异有统计学意义(P〈0.05)。结论pH值对胆源性胰腺炎外科治疗有指导意义。外科处理原则是:①胆道无梗阻,以内科保守治疗为主;②伴胆道梗阻,先行经内镜十二指肠乳头括约肌切开术、经内镜鼻胆管引流术、B超导引引流、腹腔灌洗等,如胆道引流不畅或pH值持续下降,则开腹手术。 相似文献
56.
We review our experience with brain abscesses presenting as primary brain tumor over a 5-year period (1983 to 1988). Four of 66 (6%) patients admitted with the diagnosis of primary brain tumor by computed tomographic scans were found at craniotomy to have brain abscesses. Periapical abscesses found after surgery were determined to be the cause of brain abscess in two of four patients. Our experience suggests that periapical abscess may be a more frequent cause of brain abscess than previously thought, and should be considered before surgery in patients with a suspected brain tumor. 相似文献
57.
An evaluation of the cardiovascular safety profile of duloxetine: findings from 42 placebo-controlled studies. 总被引:3,自引:0,他引:3
Joachim Wernicke Alberto Lledó Joel Raskin Daniel K Kajdasz Fujun Wang 《Drug safety》2007,30(5):437-455
BACKGROUND AND OBJECTIVE: In recent years, new classes of medication, such as the serotonin-noradrenaline reuptake inhibitors (SNRIs), have been developed for use in the treatment of major depressive disorder (MDD). For many years, treatment options were largely limited to the use of monoamine oxidase inhibitors (MAOIs), tricyclic antidepressants (TCAs) and selective serotonin reuptake inhibitors (SSRIs). However, there have been published reports of orthostatic hypotension, arrhythmias and corrected QT (QTc) interval changes in patients treated with TCAs. As new medications become available, it is important to understand how their cardiovascular safety profile compares with that of more established agents to aid clinicians and patients in choosing the best treatment options. This study was designed to evaluate the cardiovascular safety profile of the SNRI duloxetine through evaluation of cardiovascular-related parameters and adverse events (AEs). METHODS: The cardiovascular safety of duloxetine was assessed using all placebo-controlled duloxetine clinical trial data as of December 2005. This consisted of data from 42 placebo-controlled clinical trials of 8504 patients who were treated with duloxetine. Additional information from a high-dose clinical pharmacology study and postmarketing safety surveillance are also presented. Of the placebo-controlled trials included in this analysis, clinical indications under investigation included MDD (15 studies), diabetic peripheral neuropathic pain (3 studies), fibromyalgia (2 studies), generalised anxiety disorder (3 studies) and lower urinary tract disorders (19 studies, all related to incontinence). Cardiovascular safety was evaluated based on vital signs, ECGs and the incidence of treatment-emergent AEs potentially related to cardiovascular safety. These safety parameters were analysed across all indications. To identify both serious and non-serious cardiovascular-related AEs, as well as AEs reported as the reason for discontinuation, a comprehensive list of terms derived from the Medical Dictionary for Regulatory Activities (version 8.0) was generated and used to search the duloxetine databases for cardiovascular-related events. RESULTS: Calculation of change from baseline to maximum in ECG parameters showed significant differences between treatment groups for all parameters, with decreases from baseline in RR, QRS and QT intervals for patients receiving duloxetine and increases from baseline for patients treated with placebo. These shifts were related to small heart rate changes, but the mean differences were not considered clinically relevant. Categorical analyses of shifts from normal to abnormal (or abnormal to normal) for heart rate and QT corrected for heart rate using Fridericia's formula (QTcF) values showed that most patients did not shift from their baseline category. Patients with MDD who were treated for up to 1 year with duloxetine had blood pressure changes early in treatment that then stabilised. Even in patients with elevated blood pressure at baseline in these clinical trials, no increased risk of sustained blood pressure elevation with duloxetine treatment was found. CONCLUSION: Overall, the findings presented here support our conclusions that use of duloxetine does not appear to be associated with significant cardiovascular risks in patients with conditions for which the drug has been approved or studied. 相似文献
58.
重度抑郁症大学生经短周期有氧运动处方干预后抑郁症状和心肺功能的变化 总被引:1,自引:0,他引:1
文安 《中国组织工程研究与临床康复》2007,11(17):3316-3318
目的:观察短周期有氧运动处方的干预对重庆抑郁症大学生抑郁症状和心肺功能的影响。方法:于2005-09/10选择陕西省西安市8所高校中的11例患抑郁症的大学生,男6例,女5例;年龄18~25岁。均符合美国社会精神疾病的诊断统计手册标准重度抑郁症的诊断标准;均对干预方案知情同意。采用自编运动处方,即修订跑台测试方法进行有氧运动干预,训练在每周一至周六进行,每日进行5组,每组3min,共干预3周;强度以周围毛细血管血乳酸浓度达(3.0±0.5)mmol/L为标准,组间间歇期为其1/2强度至恢复,乳酸浓度监测在每第6个训练计划日进行。心率作为监测指标,由于对于训练计划的适应,心率会逐步降低,所以通过提高跑台的转速增加运动强度。运动强度评价采用Bord自我用力感觉量表,强度保持在13,14级(比较困难)。检测最大摄氧量,以反映心肺功能耐力运动表现。在训练计划开始和结束时用汉密顿抑郁量表(5级评分,0~4分,分数越高表示抑郁症状越严重)评估患者抑郁症严重程度。结果:患抑郁症大学生11名均进入结果分析。训练后患抑郁症大学生汉密顿抑郁量表分为(13.12±5.54)分,较训练前明显下降[(19.55±3.30)分,P<0.01]。训练前后患抑郁症大学生最大摄氧量分别为(35.24±10.10),(33.91±10.23)mL/(kg·min),两者比较,差异不明显(P=1.000)。结论:重度抑郁症大学生经短周期有氧训练后,抑郁症状明显改善,心肺功能未见明显增强。 相似文献
59.
Liang Ying-rui梁英锐Department of Pathology Hunan Medical University Changsha 《中华医学杂志(英文版)》1989,102(1):53-59
The cytoplasm of human bile ductule epithelia was found to be Type V collagen positive, demonstrating that the epithelia were able to generate this type of collagen. The ductules proliferated greatly with Type V collagen positive cytoplasm in piece-meal necrosis of chronic active hepatitis (CAH). The capillary-like bile ductules inside human hepatic lobules were identified. Our findings might explain the mechanism of fibroplasia in CAH. 相似文献
60.