全文获取类型
收费全文 | 168篇 |
免费 | 4篇 |
出版年
2021年 | 2篇 |
2020年 | 2篇 |
2017年 | 2篇 |
2016年 | 6篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 8篇 |
2012年 | 7篇 |
2011年 | 4篇 |
2010年 | 2篇 |
2009年 | 3篇 |
2008年 | 4篇 |
2007年 | 7篇 |
2006年 | 2篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 7篇 |
2000年 | 7篇 |
1999年 | 10篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 1篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1981年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1976年 | 4篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1972年 | 1篇 |
1961年 | 1篇 |
1956年 | 1篇 |
1953年 | 1篇 |
1927年 | 1篇 |
1926年 | 1篇 |
1925年 | 1篇 |
排序方式: 共有172条查询结果,搜索用时 15 毫秒
131.
132.
133.
Upper thermal limits of the hearts of Arctic cod Boreogadus saida: adults compared with larvae
下载免费PDF全文
![点击此处可从《Journal of fish biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
H. E. Drost J. Fisher F. Randall D. Kent E. C. Carmack A. P. Farrell 《Journal of fish biology》2016,88(2):718-726
Wild adult and reared larval Boreogadus saida were acclimated to 3·5° C before testing their cardiac response to acute warming. Heart rate transition temperatures during warming were similar for adult and larval hearts, except that the maximum temperature for heart rate was 3° C warmer for adults. Thus, in a rapidly warming Arctic Ocean, the upper temperature limit for larval rather than adult B. saida appears more likely to dictate the southern range of the species. 相似文献
134.
The techniques and protocols used to successfully capture, transport and breed Arctic cod Boreogadus saida, as well as to rear their larvae through to adulthood are summarized. Breeding B. saida will increase the opportunity to study this fish species, which is a critical part of the Arctic food web. 相似文献
135.
J.T. Drost J.P.C. Grutters G.-J. van der Wilt Y.T. van der Schouw A.H.E.M. Maas 《Netherlands heart journal》2015,23(12):585-591
Background
Women with a history of preeclampsia are at increased risk for future hypertension and cardiovascular disease (CVD); until now it is not clear whether preventive measures are needed.Methods
A decision-analytic Markov model was constructed to evaluate healthcare costs and effects of screening and treatment (100 % compliance) for hypertension post preeclampsia based on the available literature. Cardiovascular events and CVD mortality were defined as health states. Outcomes were measured in absolute costs, events, life-years and quality-adjusted life-years (QALYs). Sensitivity and threshold analyses were performed to address uncertainty.Results
Over a 20-year time horizon, events occurred in 7.2 % of the population after screening, and in 8.5 % of the population without screening. QALYs increased from 16.37 (no screening strategy) to 16.40 (screening strategy), an increment of 0.03 (95 % CI 0.01;0.05) QALYs. Total expected costs were € 8016 in the screening strategy, and € 9087 in the none screening strategy (expected saving of € 1071 (95 % CI − 3146;-87) per person).Conclusion
Annual hypertension screening and treatment in women with a history of preeclampsia may save costs, for at least a similar quality of life and survival due to prevented CVD compared with standard care.Electronic supplementary material
The online version of this article (doi:10.1007/s12471-015-0760-z) contains supplementary material, which is available to authorized users. 相似文献136.
Abstract. The effects of grazing by cattle and horses on vegetation development were studied in the well‐drained border zone of the Oostvaardersplassen nature reserve, a managed eutrophic wetland in the young Zuidelijk Flevoland polder in The Netherlands. At the start of the study period, 12 yr after the area was enclosed by dykes, the vegetation was dominated by Phragmites australis and tall herbs, particularly Cirsium arvense. Over the next 8 yr, different plant communities developed under different grazing regimes. In all communities, C. arvense was gradually replaced by Urtica dioica, and stands dominated by these two species expanded at the expense of P. australis. The shrub Sambucus nigra invaded the stands of C. arvense and U. dioica. Grazing affected the rate of these developments and the degree to which the grass Poa trivialis became dominant. When cattle were enclosed at a relatively high stocking rate in an area of Phragmites australis and tall herbaceous vegetation during summer, P. trivialis became dominant within 4 yr. The introduction of herbivores led to a faster spread of S. nigra, which contains cyanogenic glycosides which only ruminants can detoxify. Horses, as hind‐gut fermenters, did not feed on S. nigra. Grazing pressure and herbivore species, therefore, are two important variables that can be used to manage the development of Phragmites‐ and shrub vegetation: the greater the grazing pressure by cattle or horses the greater the area dominated by grasses, and a relatively high grazing pressure by cattle will retard S. nigra expansion. 相似文献
137.
D J Putney J R Malayer T S Gross W W Thatcher P J Hansen M Drost 《Biology of reproduction》1988,39(3):717-728
Effect of in vitro heat stress on protein and prostaglandin synthesis and secretion by bovine conceptuses and endometrium was examined. Conceptuses (n = 11) and endometrium (n = 10) obtained on Day 17 of pregnancy were cultured at thermoneutral (39 degrees C, 24 h) or heat stress (39 degrees C, 6 h; 43 degrees C, 18 h) temperatures in medium supplemented with L-[4,5-3H]leucine (100 microCi) and arachidonic acid (10 micrograms/ml). Radiolabeled protein secreted into culture medium increased with time in both groups. Heat stress reduced (p less than 0.001) incorporation of [3H]leucine into intracellular and secreted proteins by conceptuses but did not alter incorporation of [3H]leucine by endometrium. In particular, heat stress reduced by 72% the secretion of bovine trophoblast protein-1, the conceptus polypeptide believed to cause extension of luteal lifespan. Two-dimensional, sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that heat stress altered the array of proteins in endometrial and conceptus tissues, as evidenced by the induction of "heat-shock proteins." Endometrial secretion of prostaglandin F (p less than 0.001) and conceptus secretion of prostaglandin E2 (p less than 0.05) increased in response to heat stress. Sensitivity of bovine conceptuses and endometrium to heat stress in vitro suggests that infertility associated with maternal heat stress may be caused, partially by alterations in signals required for maintenance of the corpus luteum during early pregnancy. 相似文献
138.
139.
140.
A simple, inexpensive, flexible, balloon catheter is described, as well as its use in the collection of embryos through the cervix in cattle. The device is a commercially available balloon catheter which has been modified by the extension of its tip. Placement is with the aid of a stylet under rectal guidance. Nonsurgical recovery of bovine embryos has major advantages over surgical collection because of its repeatability and applicability to field conditions. Success with the technique depends on the diameter of the cervical canal and the manipulative skill of the operator. A 32% recovery rate from 14 superovulated cows is reported. 相似文献