全文获取类型
收费全文 | 752篇 |
免费 | 53篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 49篇 |
妇产科学 | 10篇 |
基础医学 | 98篇 |
口腔科学 | 42篇 |
临床医学 | 63篇 |
内科学 | 121篇 |
皮肤病学 | 31篇 |
神经病学 | 27篇 |
特种医学 | 218篇 |
外科学 | 27篇 |
综合类 | 34篇 |
预防医学 | 39篇 |
眼科学 | 4篇 |
药学 | 21篇 |
肿瘤学 | 42篇 |
出版年
2018年 | 5篇 |
2017年 | 5篇 |
2016年 | 9篇 |
2015年 | 7篇 |
2014年 | 14篇 |
2013年 | 12篇 |
2012年 | 8篇 |
2011年 | 16篇 |
2010年 | 22篇 |
2009年 | 24篇 |
2008年 | 26篇 |
2007年 | 14篇 |
2006年 | 18篇 |
2005年 | 11篇 |
2004年 | 11篇 |
2003年 | 10篇 |
2002年 | 5篇 |
2001年 | 14篇 |
2000年 | 8篇 |
1999年 | 14篇 |
1998年 | 39篇 |
1997年 | 44篇 |
1996年 | 40篇 |
1995年 | 36篇 |
1994年 | 23篇 |
1993年 | 31篇 |
1992年 | 19篇 |
1991年 | 17篇 |
1990年 | 13篇 |
1989年 | 23篇 |
1988年 | 28篇 |
1987年 | 44篇 |
1986年 | 25篇 |
1985年 | 16篇 |
1984年 | 8篇 |
1983年 | 12篇 |
1982年 | 14篇 |
1981年 | 20篇 |
1980年 | 17篇 |
1979年 | 8篇 |
1978年 | 6篇 |
1977年 | 9篇 |
1976年 | 21篇 |
1975年 | 10篇 |
1934年 | 4篇 |
1933年 | 3篇 |
1932年 | 2篇 |
1930年 | 3篇 |
1927年 | 4篇 |
1926年 | 4篇 |
排序方式: 共有827条查询结果,搜索用时 31 毫秒
821.
Oral Diseases (2010) 16 , 769–773 Objective: The aim of this work was to determine the frequency and nature of oral manifestations secondary to use of cardiovascular drugs. Methods: Five hundred and thirty one patients attending an adult cardiology clinic in Saudi Arabia were questioned about the occurrence of oral dryness, dysgeusia, or burning sensation and were clinically evaluated for the presence of oral mucosal or gingival disease. Data were statistically analyzed with chi‐squared tests, odds ratios and Student’s t‐test. Results: Oral symptoms and/or signs were recorded in 75 (14.1%) patients with xerostomia being the most common (7.5%), followed by lichenoid (lichen planus‐like) lesions (3.6%) and dysgeusia (1.9%). Xerostomia was significantly more frequent in patients with a history of diabetes mellitus and in female patients (P < 0.05). There were no statistically significant differences (P > 0.05) between patients with or without oral manifestations when age, gender, cardiovascular risk factor, cardiac disease, type of cardiac drug used or the number of medications were assessed. There was a trend for xerostomia to be less frequent in patients receiving therapy with angiotensin converting enzyme inhibitors and a slight trend of xerostomia to be more likely with increased number of non‐cardiac and total number of agents per subject. The number of non‐cardiac and total medications taken by patients with potential oral manifestations tended to be greater than that of patients without oral manifestations. Conclusions: The frequency of potential oral manifestations in patients receiving cardiovascular agents was 14.1%. The occurrence and character of the oral manifestations had no significant relation with individual cardiac drugs, although there was a trend for oral manifestations to be likely with increasing number of drugs. 相似文献
822.
Carol A. Janney MS Jane A. Cauley DR PH Peggy M. Cawthon PhD MPH Andrea M. Kriska PhD for the Osteoporotic Fractures in Men Study Group 《Journal of the American Geriatrics Society》2010,58(6):1128-1133
OBJECTIVES: To describe the change in physical activity (total, leisure, household, occupational) in men over a mean 5‐year follow‐up period and to identify sociodemographic and health factors associated with change in physical activity. DESIGN: Prospective cohort study; Osteoporotic Fractures in Men Study; data collected March 2000 through May 2006. SETTING: Six U.S. clinical centers. PARTICIPANTS: Volunteer sample of ambulatory community‐dwelling men aged 65 and older (N=5,161). MEASUREMENTS: Self‐reported physical activity assessed at baseline and Visit 2 (V2) (5 years apart) according to the Physical Activity Scale for the Elderly (PASE) (unitless, relative measure of physical activity). RESULTS: At baseline, PASE scores averaged 16.8±35.5 for occupational, 37.0±34.0 for leisure, 95.9±43.2 for household, and 149.7±67.6 for total physical activity. Occupational (?6.2±33.9), leisure (?3.2±37.3), household (?9.9±44.3), and total (?19.3±67.7) physical activity change scores declined, on average, from baseline to V2. On average, change in total PASE scores declined more with age: ?15.6±71.6 for men younger than 70, ?16.4±67.0 for men aged 70 to 74, ?21.4±66.9 for men aged 75 to 79, and ?29.5±60.7 for men aged 80 and older. Living alone, smoking cigarettes, poor health, and higher blood pressure were associated with greater declines in physical activity over time. Although average scores declined, some older men (1,335, 26%) reported increasing physical activity levels. Better physical and mental health, living with others, and being younger were associated with the probability of increasing physical activity over time. CONCLUSION: Over the 5‐year period, the majority of men reported declines in total physical activity. Older men in poor health who live alone have a high risk of physical activity declines and may be an important group to target for exercise interventions. 相似文献
823.
Zhao ZZ Nyholt DR Le L Martin NG James MR Treloar SA Montgomery GW 《Molecular human reproduction》2006,12(11):671-676
Endometriosis is a common gynaecological disease with symptoms of pelvic pain and infertility which affects 7-10% of women in their reproductive years. Activation of an oncogenic allele of Kirsten rat sarcoma viral oncogene homologue (KRAS) in the reproductive tract of mice resulted in the development of endometriosis. We hypothesized that variation in KRAS may influence risk of endometriosis in humans. Thirty tagSNPs spanning a region of 60.7 kb across the KRAS locus were genotyped using iPLEX chemistry on a MALDI-TOF MassARRAY platform in 959 endometriosis cases and 959 unrelated controls, and data were analysed for association with endometriosis. Genotypes were obtained for most individuals with a mean completion rate of 99.1%. We identified six haplotype blocks across the KRAS locus in our sample. There were no significant differences between cases and controls in the frequencies of individual single-nucleotide polymorphisms (SNPs) or haplotypes. We also developed a rapid method to screen for 11 common KRAS and BRAF mutations on the Sequenom MassARRAY system. The assay detected all mutations previously identified by direct sequencing in a panel of positive controls. No germline variants for KRAS or BRAF were detected. Our results demonstrate that any risk of endometriosis in women because of common variation in KRAS must be very small. 相似文献
824.
825.
Kaiting Fan MS RN Wenya Cao MS RN Hong Chang MS RN Fei Tian PhD DR 《Journal of clinical hypertension (Greenwich, Conn.)》2023,25(11):1009-1018
The use of machine learning (ML) in predicting disease prognosis has increased, and researchers have adopted different methods for variable selection to optimize early screening for AIS to determine its prognosis as soon as possible. We aimed to improve the understanding of the predictors of poor functional outcome at three months after discharge in AIS patients treated with intravenous thrombolysis and to construct a highly effective prognostic model to improve prediction accuracy. And four ML methods (random forest, support vector machine, naive Bayesian, and logistic regression) were used to screen and recombine the features for construction of an ML prognostic model. A total of 352 patients that had experienced AIS and had been treated with intravenous thrombolysis were recruited. The variables included in the model were NIHSS on admission, age, white blood cell count, percentage of neutrophils and triglyceride after thrombolysis, tirofiban, early neurological deterioration, early neurological improvement, and BP at each time point or period. The model's area under the curve for predicting 30-day modified Rankin scale was 0.790 with random forest, 0.542 with support vector machine, 0.411 with naive Bayesian, and 0.661 with logistic regression. The random forest model was shown to accurately evaluate the prognosis of AIS patients treated with intravenous thrombolysis, and therefore they may be helpful for accurate and personalized secondary prevention. The model offers improved prediction accuracy that may reduce rates of misdiagnosis and missed diagnosis in patients with AIS. 相似文献
826.
827.