全文获取类型
收费全文 | 124篇 |
免费 | 5篇 |
出版年
2021年 | 2篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2016年 | 1篇 |
2015年 | 6篇 |
2014年 | 4篇 |
2013年 | 4篇 |
2012年 | 4篇 |
2011年 | 4篇 |
2010年 | 5篇 |
2009年 | 2篇 |
2008年 | 4篇 |
2007年 | 10篇 |
2006年 | 5篇 |
2005年 | 8篇 |
2004年 | 7篇 |
2003年 | 2篇 |
2002年 | 1篇 |
2001年 | 8篇 |
2000年 | 1篇 |
1999年 | 6篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1996年 | 1篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 5篇 |
1982年 | 6篇 |
1981年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1937年 | 2篇 |
排序方式: 共有129条查询结果,搜索用时 15 毫秒
121.
122.
Morphometric and metabolic indices of disuse in muscles of hibernating ground squirrels. 总被引:4,自引:0,他引:4
J M Steffen D A Koebel X J Musacchia W K Milsom 《Comparative biochemistry and physiology. B, Comparative biochemistry》1991,99(4):815-819
1. Morphological, biochemical and metabolic characteristics of hindlimb muscles from summer-active (SA), winter-active (WA) and hibernating (H) golden-mantled ground squirrels (Spermophilus lateralis) were examined to identify alterations resulting from seasonal periods of inactivity. 2. Cross-sectional areas of fibers from the soleus were reduced in both WA and H, although only significantly (P less than 0.05) in WA. Fibers in the EDL exhibited significant reductions in cross-sectional areas in both H and WA groups. Muscle fiber and capillary densities were altered in quantitative agreement with changes in cross-sectional areas. 3. Protein content was reduced 20% (P less than 0.05) in EDL from H and WA groups, but reductions (10%) in the soleus were not statistically significant. RNA content in WA and H groups was significantly decreased in soleus (20%) and EDL (35%) compared with SA, but DNA content was unchanged. 4. In the plantaris, triglyceride content was unchanged, but citrate synthase activity in H (210 +/- 13 mumol min-1 g-1) was significantly greater than in SA (177 +/- 10). In contrast, LDH activity in H was reduced by 25% (P less than 0.05) compared with SA. 5. These results demonstrate atrophic effects associated with seasonal inactivity in hibernating ground squirrels, but suggest the existence of natural mechanisms which limit the response. 相似文献
123.
124.
P. J. Butler W. K. Milsom A. J. Woakes 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1984,154(2):167-174
Summary Heart rate and pulmonary artery blood flow of resting green turtles,Chelonia mydas, at 29°C increased with lung ventilation (heart rate from 24±5 to 51±8 beats min). When swimming at 0.6 m s–1 in water at 30°C, oxygen uptake was 2.83 times and respiratory frequency was 2.75 times the resting values. Heart rate was 1.33 times that during ventilation at rest but 2.83 times that at the end of a breath hold at rest. Partial pressures of oxygen and carbon dioxide, lactic acid concentration and pH of arterial blood, when swimming at 0.5 m s–1, were similar to those soon after ventilation at rest. Pulmonary blood flow did not decline to low levels between breaths, when the animals were swimming, as it did when they were at rest.In active turtles it appears that pulmonary perfusion remains elevated, supplying oxygen to the locomotory muscles at a sufficiently high rate to support the complete aerobic production of energy, and that respiratory frequency is kept as low as possible, as surfacing for air increases the metabolic cost of swimming. 相似文献
125.
126.
127.
SYNOPSIS. Ochromonas danica in a complex natural growth medium dies at 6–10 C in 4 days; O. malhamensis in ∼2 days. O. danica grown in the medium supplemented with 4.0% glycerol survived at −10±2 C for 35 days, and with 8% glycerol 29 days. O. malhamensis lasted only to 5 days in these media supplemented with 4% glycerol. Ethylene glycol and dimethylsulfoxide were too toxic to be effective. Difficulties in freeze-preservation of certain other phagocytic cells, notably blood granulocytes having comparatively simple flexuous outer membranes, add interest to use of O. danica and O. malhamensis as test organisms for preservation methods, especially in the convenient, inexpensive -10 to -20 C range. Biphasic media with an overlay of distilled water serve for conservation at room temperature. Problems of mutational erosion of these photosynthetic phagotrophs are discussed. 相似文献
128.
129.