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排序方式: 共有410条查询结果,搜索用时 15 毫秒
61.
Myers CJ Magdesian KG Kass PH Madigan JE Rhodes DM Marks SL 《Veterinary journal (London, England : 1997)》2009,181(2):137-144
This retrospective study describes the use of and complications associated with parenteral nutrition (PN) administration to 53 equine neonates at the University of California Veterinary Medical Teaching Hospital. Medical records were examined and information obtained on signalment, physical examination, clinical diagnosis, outcome, total hospitalization time, insulin administration, microbiology culture results, other complications (i.e. thrombophlebitis) and necropsy findings. Complete blood count and serum biochemistry analytes, venous blood gas, serum electrolyte and glucose concentrations, and blood lactate concentration results were compared before and during PN administration in all foals. Seventeen foals (32%) developed hypertriglyceridemia (>200mg/dL). Triglyceride concentrations >200mg/dL were significantly (P=0.049) associated with non-survival. Forty-seven foals (89%) developed hyperglycemia (blood glucose >120mg/dL) and eight (15%) developed catheter-related complications (thrombosis or local sepsis). Packed cell volume, total protein, creatinine, blood urea nitrogen, and sorbitol dehydrogenase concentrations decreased while foals were on PN, while serum chloride concentration increased. This study highlighted that hypertriglyceridemia during the acute phase of neonatal illness may be detrimental to outcome, and that the safety of lipid-containing solutions in foals warrants further study. 相似文献
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63.
Liquid manure storage may contribute to methane(CH4) emission and this emission can be greatly reduced if appropriate management practices are applied. Biofiltration has been used in other fields for mitigating greenhouse gas(GHG) emission(e.g.,landfill) and shown promise for mitigation CH4 emission from liquid manure storage. It has been reported that biofilter was capable of reducing 80% of CH4 emissions from manure storage. The CH4 removal efficiency is influenced by many factors,including CH4 and O2 concentrations,temperature,moisture,composition of the filter bed,nutrient,and empty bed residency time(EBRT) . Biological conversion of methane of a biofilter is a slow process due to the low water solubility of methane. The residence times(EBRT) between 5 min and 5 h have been used,whereas a typical EBRT of 25 s is used for common biofilter applications. Temperature at which methanotrophic bacteria are active ranges from 10oC to 45oC. The maximum activity is found at around 30oC. The optimal filter bed water content depends on both the gas flow rate and the type of filter bed(soil,compost,etc.) and ranges from 30%-70% of the water holding capacity. Compost is the best material for filter bed. The optimal pH for methanotrophic bacteria is neutral to slightly acidic. Copper and nitrogen compounds especially nitrate are important nutrients to methanotrophic bacteria but their optimal concentrations have not been founded. Phosphorus and other elements such as potassium and manganese are reported to affect the performance of methanotrophic bacteria but need further confirmation. 相似文献
64.
寻觅那只古老的花瓶,你曾用它插放过岁月静好时的叹息。在灯光的终点处,一只金羽鸟停在水罐上,唱着古老的曲调。有一种梦想泛着微蓝的光芒,有一种优雅绽放出原始的姿态。 相似文献
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66.
Zhai Y Pierre D Si R Deng W Ferrin P Nilekar AU Peng G Herron JA Bell DC Saltsburg H Mavrikakis M Flytzani-Stephanopoulos M 《Science (New York, N.Y.)》2010,329(5999):1633-1636
We report that alkali ions (sodium or potassium) added in small amounts activate platinum adsorbed on alumina or silica for the low-temperature water-gas shift (WGS) reaction (H(2)O + CO → H(2) + CO(2)) used for producing H(2). The alkali ion-associated surface OH groups are activated by CO at low temperatures (~100°C) in the presence of atomically dispersed platinum. Both experimental evidence and density functional theory calculations suggest that a partially oxidized Pt-alkali-O(x)(OH)(y) species is the active site for the low-temperature Pt-catalyzed WGS reaction. These findings are useful for the design of highly active and stable WGS catalysts that contain only trace amounts of a precious metal without the need for a reducible oxide support such as ceria. 相似文献
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68.
Shelly L. Vaden DVM PhD DACVIM Coral A. Turman DVM Tonya L. Harris Steven L. Marks BVSc MS MRCVS DACVIM 《Journal of Veterinary Emergency and Critical Care》2010,20(5):479-487
Objective – To evaluate the prevalence of albuminuria in dogs and cats admitted to the ICU or recovering from an anesthetic event. Design – Prospective clinical study over a 10‐week period in 2003. Setting – Veterinary teaching hospital. Animals – One hundred and five dogs and 22 cats. Interventions – Urine was collected from dogs and cats admitted to the ICU or recovering from an anesthetic event. When possible, a second urine sample was collected approximately 48 hours later from those animals that had albuminuria during the initial screening. Measurements and Main Results – All dog samples and most cat samples were screened for albumin using a commercial point‐of‐care immunoassay. Aliquots of samples that tested positive were stored at –20°C until subsequent albumin quantification via antigen capture ELISA. Albuminuria was detected in 63 of 105 (60.0%) dogs and in 14 of 22 (63.6%) cats; the prevalence was higher in animals admitted to ICU than in those recovering from anesthesia. In subsequent samples from 26 dogs, urine albumin decreased in 20 (76.9%) when compared with the first sample; urine albumin was undetectable in 5 (19.2%). In subsequent samples from 6 cats, 4 (66.7%) had decreases in urine albumin when compared with the first sample; 1 (16.7%) was negative for urine albumin. Eleven of 12 dogs (91.7%) and 3 of 4 cats (75%) that died within 3 days of admission to the ICU had abnormal urine albumin; whereas 52 of 93 (55.9%) and 11 of 18 (61.1%) dogs and cats, respectively, who survived more than 3 days had abnormal urine albumin. Dogs with albuminuria were at increased risk of death. Conclusions – The prevalence of albuminuria in animals admitted to the ICU or recovering from anesthesia is higher than reported previously and transient in some patients. The presence of albuminuria may be a negative prognostic indicator in this population. 相似文献
69.
T. R. Marks Sally E. Simpson 《The Journal of Horticultural Science and Biotechnology》2013,88(5):815-824
Three physiologically distinct forms of the same genotype of Quercus robur ‘Fastigiata’, all derived from adult budwood, were identified following the growth of severely-pruned hedge plants grafted onto juvenile seedling rootstocks. Only explants from the form displaying the juvenile-like characteristic of over-winter leaf retention were capable of establishing sustainable cultures in vitro, although growth was not as rapid as those from a two year old seedling source. Pruning to release correlative inhibition of buds low on the scion framework produced vigorous shoot growth, but explants from these failed to show sustained growth in vitro. Withholding light from stockplants reduced excessive phenolic oxidation in explants taken from flushing unripe shoots, however, despite a beneficial effect on culture initiation, later growth was dependent upon the juvenile- or adult-like physiology of the original explant. A new medium was devised for this subject, which in addition to promoting growth generally, also stimulated the flushing of shoot apices. The relevance to in vitro culture of expression of juvenile habit in the stockplant is discussed. 相似文献
70.
Rapid urbanization and spontaneous economic development has brought about profound changes in urban landscapes throughout the world. The task of managing transforming urban landscapes, particularly urban green spaces, so as to provide sufficient natural amenity for increasing urban populations, is one of the critical challenges facing policy makers. However, little empirical evidence exists about the evolving path of urban green spaces along with economic development and urbanization. This study attempts to fill in this knowledge gap through an econometric analysis of panel data across 285 Chinese cities during a period of rapid urbanization and economic growth (2001–2010). The results point to the existence of an N-shaped environmental Kuznets curve (EKC) for an important aspect of environmental quality: urban green spaces. Urban green space coverage increases at the initial stage of economic development, and then it starts to decrease as GDP per capita exceeds RMB50,855 and then increases again at a high GDP per capita level (RMB107,558). Large elasticity (>1) is expected as GDP per capita grows to a higher level (beyond RMB128,095). By the end of 2010, 30% of Chinese cities are still located on the downward-sloping path and only four cities have attained elasticities greater than one. The findings present a challenging and pressing call for policy makers to effectively manage the tradeoffs between continuous economic development and better natural amenities. 相似文献