全文获取类型
收费全文 | 176篇 |
免费 | 28篇 |
出版年
2022年 | 2篇 |
2021年 | 2篇 |
2019年 | 3篇 |
2018年 | 5篇 |
2017年 | 1篇 |
2016年 | 2篇 |
2015年 | 7篇 |
2014年 | 4篇 |
2013年 | 16篇 |
2012年 | 7篇 |
2011年 | 4篇 |
2010年 | 4篇 |
2009年 | 3篇 |
2008年 | 11篇 |
2007年 | 12篇 |
2006年 | 12篇 |
2005年 | 6篇 |
2004年 | 9篇 |
2003年 | 7篇 |
2002年 | 4篇 |
2001年 | 8篇 |
2000年 | 2篇 |
1999年 | 8篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1995年 | 5篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 10篇 |
1991年 | 8篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有204条查询结果,搜索用时 0 毫秒
201.
John R. Rowley John J. Skvarla John M. Pettitt 《Review of Palaeobotany and Palynology》1992,70(4):297-323
In Eucommia the foot layer plays a prominent part in microspore wall development. Bacules (>100 nm) are rods originating within the foot layer. Small bacules (diameter ca. 10 nm) form at the same time as the foot layer. The tectum is considered to be made up of these microbacular rods. Spinules ar continuous with the bacules. An endexine is differentiated during a middle to late microspore stage. Except for the pore the furrow includes tectum and foot layer on the endexine. Since the furrow consists of a region of reduced foot layer and the reduction is gradual near the polar ends of furrows, assessment of furrow length depends to some extent upon variations in exine infolding. The pore is well defined, but, because it is crossed by lamellations of the endexine and foot layer and often overlaid by tongues and bridges of foot layer plus tectum (including spinules) it is obscured from view using either light microscopy or scanning electron microscopy. 相似文献
202.
203.
R. Arlen Price Marie Aline Charles David J. Pettitt William C. Knowler 《American journal of physical anthropology》1993,92(4):473-479
Several studies have shown secular increases in obesity during the past 35 years, and others have reported increases in dietary fat consumption during the same period. Here we report a dramatic increase in obesity among Pima Indians born after World War II that appears to be associated with increased exposure to Western customs and diet following 1945. We examined the body mass index (BMI = weight in kilograms/height2 in meters) of 1,128 male and 1,372 female Pima Indians aged 15–65 years who were born between 1901 and 1964 and were examined between 1965 and 1990. We found large increases in BMI among Pima Indian men and women in post-World War II birth cohorts (1945 and later). The parallel changes in body mass index, dietary fat, and exposure to Western culture following World War II suggest that culturally mediated changes in diet and level of physical activity associated with modern industrialized society may have led to the large increases in obesity in the Pima Indians and to smaller parallel changes observed worldwide in westernized countries. © 1993 Wiley-Liss, Inc. 相似文献
204.
D. R. McCance R. L. Hanson M. A. Charles L. T. Jacobsson D. J. Pettitt P. H. Bennett W. C. Knowler 《BMJ (Clinical research ed.)》1994,308(6940):1323-1328
OBJECTIVE--To compare the ability of tests measuring two hour plasma glucose, fasting plasma glucose, and glycated haemoglobin concentrations in predicting the specific microvascular complications of non-insulin dependent diabetes mellitus. DESIGN--Cross sectional and longitudinal analysis of the relation between complications and concomitant results of the three tests. SETTING--Gila River Indian Community, Arizona. SUBJECTS--Pima Indians (cross sectional, n = 960), aged 25 years or above who were not receiving insulin or oral hypoglycaemic treatment at the baseline examination. MAIN OUTCOME MEASURES--Development of retinopathy and nephropathy. RESULTS--Cross sectionally, frequency distributions of logarithms of the three sets of results were bimodal, with the prevalence of retinopathy and nephropathy being, respectively, 12.0-26.7 and 3.9-4.2 times as high above as below cut off points which minimised overlap (two hour plasma glucose concentration 12.6 mmol/l; fasting plasma glucose concentration 9.3 mmol/l; glycated haemoglobin (HbA1c) concentration 7.8%). Longitudinally, each of the three measures of glycaemia significantly predicted the development of retinopathy (P < 0.0001) and nephropathy (P < 0.05). Receiver operating characteristic curves showed that two hour plasma glucose concentration was superior to fasting plasma glucose concentration (P < 0.05) for prevalent cases of retinopathy, but otherwise no variable had a significant advantage for detecting incident or prevalent cases of either complication. CONCLUSIONS--These findings suggest that determination of glycated haemoglobin or fasting plasma glucose concentrations alone may be acceptable alternatives to measuring glucose concentration two hours after challenge with 75 g glucose for the diagnosis of diabetes. 相似文献