全文获取类型
收费全文 | 111篇 |
免费 | 7篇 |
国内免费 | 7篇 |
专业分类
妇产科学 | 1篇 |
基础医学 | 9篇 |
口腔科学 | 3篇 |
临床医学 | 23篇 |
内科学 | 23篇 |
皮肤病学 | 3篇 |
神经病学 | 2篇 |
特种医学 | 20篇 |
外科学 | 22篇 |
综合类 | 2篇 |
预防医学 | 5篇 |
眼科学 | 4篇 |
药学 | 3篇 |
肿瘤学 | 5篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2013年 | 3篇 |
2011年 | 2篇 |
2010年 | 9篇 |
2009年 | 4篇 |
2008年 | 7篇 |
2007年 | 10篇 |
2006年 | 8篇 |
2005年 | 1篇 |
2004年 | 7篇 |
2003年 | 3篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1998年 | 7篇 |
1997年 | 7篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有125条查询结果,搜索用时 15 毫秒
71.
72.
A Nkengne†‡§ C Bertin§ GN Stamatas§ A Giron†‡ A Rossi§ N Issachar§ B Fertil¶ 《Journal of the European Academy of Dermatology and Venereology》2008,22(8):982-991
Background and objective The facial appearance of a person does not always reflect the chronological age; some people look younger or older than they really are. Many studies have described the changes in skin properties (colour, wrinkles, sagging, micro relief, etc.) with age, but few of them have analysed their influence on the perceived age. The primary objective of this study was to assess the contribution of individual skin attributes of the face on the perceived age of Caucasian women. Secondary objectives were to assess the influence of age and gender of graders with regard to the age perception. Subjects and method A random sample of 173 subjects of 20 to 74 years of age was taken from a database of more than 5000 healthy Caucasian women. A trained grader performed visual assessment of facial skin attributes (using a visual analogue scale), and a front face photograph was taken from each subject. Photographs were shown to 48 graders (20 men and 28 women, aged 22–64 years) who were asked to estimate the age of the subjects. Graders were classified as young (less than 35 years), middle age (35–50 years) and seniors (older than 50 years). Partial Least Square regression models were built to predict the chronological and the perceived age from the measured facial individual attributes. The contribution of each attribute within the regression model enabled to measure the relevance of this attribute with regards to age prediction. Results The eye area and the skin colour uniformity were the main attributes related to perceived age. For age prediction, older graders’ estimations were more driven by lips border definition shape and eyes opening, whereas younger graders’ (older than 50 years) estimations were more driven by dark circles, nasolabial fold and brown spots. There were statistically significant differences in graders’ age perception between gender and among age ranges. Our findings suggest that female graders are more accurate than male, and younger graders (under 35 years) are more accurate than older (over 50 years) to predict Caucasian women age from facial photographs. Conclusions Different skin attributes influence the estimation of age. These attributes have a different weight in the evaluation of the perceived age, depending on the age and of the observer. The most important attributes to estimate age are eyes, lips and skin colour uniformity. 相似文献
73.
74.
75.
A simplified quantitative cervical mucus penetration test 总被引:1,自引:1,他引:0
A simplified quantitative cervical mucus penetration test was developed and
applied to the semen of 21 prospective donors in order to evaluate its
performance. Analysis of the data using stepwise multiple regression
revealed that the concentration of spermatozoa in mucus was related
primarily to the concentration of progressive spermatozoa in the semen (63%
of variance explained), and secondarily to the average path velocity of
spermatozoa in semen (70% of variance explained by a model incorporating
both variables). However, consistent with previous studies, the derived
indices of penetration efficiency including the percentage successful
collisions (PSC), percentage successful entries (PSE) and the motile
density ratio (MDR) were not significantly correlated with any of the semen
variables examined, although multiple regression did derive models which
explained 27-31% of the variance in these three dependent variables. The
strong correlation and correspondence between the PSC and the MDR suggests
that the latter may provide a simplified index of penetration efficiency
for routine clinical use and further research in this area.
相似文献
76.
Bart M Wiarda Mark Stolk Dimitri GN Heine Peter Mensink Mai E Thieme Ernst J Kuipers Jaap Stoker 《Journal of gastroenterology and hepatology》2013,28(3):464-471
Background and Aim: We aimed to prospectively determine patient burden and patient preference for magnetic resonance enteroclysis, capsule endoscopy and balloon‐assisted enteroscopy in patients with suspected or known Crohn's disease (CD) or occult gastrointestinal bleeding (OGIB). Methods: Consecutive consenting patients with CD or OGIB underwent magnetic resonance enteroclysis, capsule endoscopy and balloon‐assisted enteroscopy. Capsule endoscopy was only performed if magnetic resonance enteroclysis showed no high‐grade small bowel stenosis. Patient preference and burden was evaluated by means of standardized questionnaires at five moments in time. Results: From January 2007 until March 2009, 76 patients were included (M/F 31/45; mean age 46.9 years; range 20.0–78.4 years): 38 patients with OGIB and 38 with suspected or known CD. Seventeen patients did not undergo capsule endoscopy because of high‐grade stenosis. Ninety‐five percent (344/363) of the questionnaires were suitable for evaluation. Capsule endoscopy was significantly favored over magnetic resonance enteroclysis and balloon‐assisted enteroscopy with respect to bowel preparation, swallowing of the capsule (compared to insertion of the tube/scope), burden of the entire examination, duration and accordance with the pre‐study information. Capsule endoscopy and magnetic resonance enteroclysis were significantly preferred over balloon‐assisted enteroscopy for clarity of explanation of the examination, and magnetic resonance enteroclysis was significantly preferred over balloon‐assisted enteroscopy for bowel preparation, painfulness and burden of the entire examination. Balloon‐assisted enteroscopy was significantly favored over magnetic resonance enteroclysis for insertion of the scope and procedure duration. Pre‐ and post‐study the order of preference was capsule endoscopy, magnetic resonance enteroclysis and balloon‐assisted enteroscopy. Conclusion: Capsule endoscopy was preferred to magnetic resonance enteroclysis and balloon‐assisted enteroscopy; it also had the lowest burden. Magnetic resonance enteroclysis was preferred over balloon‐assisted enteroscopy for clarity of explanation of the examination, bowel preparation, painfulness and burden of the entire examination, and balloon‐assisted enteroscopy over magnetic resonance enteroclysis for scope insertion and study duration. 相似文献
77.
目的 研究中老年人核苷酸外焦磷酸酶/磷酸二酯酶1(ENPP1)基因多态位点rs1409181与左心室肥厚的关系.方法 从"广州生物库队列-CVD"项目中的1996名研究对象随机选出390名年龄≥50岁的中老年广州市居民,收集其个人资料与病史、体格检查并测定血清空腹血糖、血脂水平;应用彩色多普勒超声诊断仪,同步连接心电图,测定左心室舒张末期内径(LVIDD)、舒张期室间隔厚度(IVSD)、舒张期后壁厚度(LVPWD).根据Devereux公式计算左心室质量(LVM)和左心室质量指数(LVMI)以判断左心室肥厚.应用荧光定量PCR方法检测ENPP1基因rs1409181位点的基因型.结果 ENPP1基因GG、CG和CC 3个基因型组左心室肥厚的比率分别为21.5%、28.2%和37.5%.与GG基因型相比,CG和CC基因型经调整包括血压和胰岛素抵抗指数在内等多种混杂因素后,对左心室肥厚的比值比(OR)分别为1.39(95%CI:0.78~2.50)和2.36(95%CI:1.21~4.60),趋势检验P=0.01.结论 ENPP1基因多态位点rs1409181与左心室肥厚显著相关. 相似文献
78.
Objective To examine the association between genetic polymorphism of rs1409181 in ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) and left ventricular hypertrophy (LVH) among older Chinese in Guangzhou. Methods 390 subjects aged ≥50 years were randomly selected from the Guangzhou Biobank Cohort Study-CVD. Information on personal history, blood pressure, fasting plasma glucose and lipids were collected. Color Doppler ultrasound was used to measure the indicators of LVH, including left ventricular internal diastolic diameter (LVIDD) , thickness of the interventricular septum diastolic wall (IVSD) and the posterior wall diastolic diameter (LVPWD). LVIDD was calculated using Devereux ventricular mass (LVM)equation while the Left ventricular mass index (LVMI) equation was used to estimate LVH. The genotype of rs1409181 was determined by Taqman SNP genotyping kits using the ABI 7900HT real time PCR system. Results In the GG, CG and CC genotype groups, the proportions of LVH were 21.5%, 28.2% and 37.5% respectively. Compared with GG, the adjusted odds ratios (95% confidence interval) for the LVH were 1.39(0.78-2.50) and 2.36(1.21-4.60) for CG genotype and CC genotype of ENPP1 respectively (P for trend=0.01). Conclusion Polymorphism of ENPP1 gene rs1409181 was associated with LVH in the older Chinese people in Guangzhou. 相似文献
79.
80.