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排序方式: 共有340条查询结果,搜索用时 31 毫秒
171.
Durno AS Webb JA Gauthier MJ Bienzle D 《Journal of the American Animal Hospital Association》2011,47(2):122-128
Two dogs presented with suspected renal disease and polycythemia. Abdominal ultrasound examinations performed on both dogs revealed coalescing masses causing bilateral renomegaly. Serum erythropoietin (EPO) concentrations were physiologically inappropriate. Postmortem examinations revealed renal T-cell lymphoma in both dogs. One of the two dogs also had involvement of the liver and mesentery. EPO-immunohistochemistry on tissue samples demonstrated positive staining in tumor cells and occasional normal renal cells. This report illustrates that paraneoplastic EPO production may induce polycythemia. The pattern of EPO-immunohistochemistry staining suggested that the mechanism of production was due to tumor production of EPO and local hypoxia-induced EPO production from compression of normal renal cells and vasculature. 相似文献
172.
Pinard CL Gauvin D Moreau M Martel-Pelletier J Pelletier JP Troncy E 《Veterinary ophthalmology》2011,14(5):296-303
Objectives Phase I: To evaluate levels of prostaglandin E2 (PGE2), nitrites and nitrates (NOx), tumor necrosis factor‐alpha (TNF‐α) and expression of inducible cyclo‐oxygenase (COX‐2), nitric oxide synthase (NOS‐2), and matrix metalloproteinases (MMP‐3 and ‐9) in canine aqueous humor following repeated anterior chamber paracenteses (ACP). Phase II: to evaluate the effect of carprofen on PGE2, NOx, and TNF‐α in canine aqueous humor following ACP. Animals studied Four beagles in phase I and 8 beagles in phase II. Procedures Phase I: ACP was performed at time (T) 0, 4 and 8 h. Phase II: A randomized, placebo‐controlled cross‐over design with four dogs per group where carprofen was given 4.4 mg/kg/day on day (D) 1, 2 and 3. ACP was performed at T0 and T1.5 on D3. Statistical analysis was performed with repeated measures anova and post hoc Tukey‐Kramer multiple‐comparison procedure. In phase II, TNF‐α level was analyzed with a Wilcoxon signed‐rank test. Results Phase I: PGE2 significantly increased (P < 0.0001) to plateau at T4. NOX was decreased at T4 (P < 0.06), but increased at T8 (P < 0.0001). COX‐2 showed detectable expression only at T8. TNF‐α, NOS‐2, MMP‐3 and ‐9 were undetectable at all time points. Phase II: At T1.5, PGE2 was significantly elevated in both groups but was lower in the carprofen group (P = 0.037). NOx and TNF‐α did not statistically increase in either group. Conclusions Following ACP, significant increases in PGE2 levels confirmed inflammation characterized by a rise of COX‐2. The NOx pathway took longer to induce as compared with PGE2. Carprofen decreased PGE2 levels and could help control intraocular inflammation. 相似文献
173.
Gabriela Grille Nathalie Gauthier José Buenahora César Basso Olivier Bonato 《Phytoparasitica》2011,39(3):235-238
Bemisia tabaci adults were collected from pepper and melon at different commercial production greenhouses in Argentina and Uruguay. The
biotype status of adults was then established using cytochrome oxidase I gene (mtCOI) as molecular marker. Only the Q biotype
was found on all plants sampled. This is the first report of the Q biotype in Argentina and Uruguay. 相似文献
174.
Walnut (Juglans spp.) ecophysiology in response to environmental stresses and potential acclimation to climate change 总被引:1,自引:0,他引:1
? Context
Walnuts (Juglans spp.) are ecologically and commercially important trees, yet synthesis of past and current research findings on walnut ecophysiology is lacking, especially in terms of potential acclimation to climate change.? Aims
This study aims to (1) investigate walnut ecophysiology by comparing its attributes to associated deciduous angiosperms, (2) address potential acclimation of walnut to climate change, and (3) identify areas for prioritization in future research.? Results
There is considerable uncertainty regarding the magnitude of potential effects of climate change on walnut. Some studies tend to indicate walnut could be negatively impacted by climate change, while others do not. Walnut may be at a disadvantage due to its susceptibility to drought and frost injury in current growing regions given the projected increases in temperature and extreme climatic events. Other regions that are currently considered cold for walnut growth may see increased establishment and growth depending upon the rate of temperature increase and the frequency and severity of extreme climatic events.? Conclusion
Research investigating a combination of environmental factors, such as temperature, carbon dioxide, ozone, water, and nitrogen is needed to (1) better project climate change effects on walnut and (2) develop management strategies for walnut acclimation and adaptation to climate change. 相似文献175.
We describe a method for storing sequences of optical data pulses by converting them into long-lived acoustic excitations in an optical fiber through the process of stimulated Brillouin scattering. These stored pulses can be retrieved later, after a time interval limited by the lifetime of the acoustic excitation. In the experiment reported here, smooth 2-nanosecond-long pulses are stored for up to 12 nanoseconds with good readout efficiency: 29% at 4-nanosecond storage time and 2% at 12 nanoseconds. This method thus can potentially store data packets that are many bits long. It can be implemented at any wavelength where the fiber is transparent and can be incorporated into existing telecommunication networks because it operates using only commercially available components at room temperature. 相似文献
176.
177.
Salmonella enterica causes a variety of diseases, including gastroenteritis and typhoid fever. The success of this pathogen depends on its capacity to proliferate within host cells in a membrane-bound compartment. We found that the Salmonella-containing vacuole recruited the plus-end-directed motor kinesin. Bacterial effector proteins translocated into the host cell by a type III secretion system antagonistically regulated this event. Among these effectors, SifA targeted SKIP, a host protein that down-regulated the recruitment of kinesin on the bacterial vacuole and, in turn, controlled vacuolar membrane dynamics. 相似文献
178.
Asian carp farming systems: towards a typology and increased resource use efficiency 总被引:1,自引:0,他引:1
Resource use efficiency in Asian carp farming systems is analysed based on a survey of 2493 farms of nine countries. Multivariate classification of farms by intensity and diversity identified six farm types: four types of specialized aquaculture farms at different levels of intensity, and two types of integrated agriculture–aquaculture systems. Pond‐based, specialized semi‐extensive systems (using mainly inorganic fertilizers and feeds of off‐farm origin), and integrated semi‐intensive systems (using feeds and fertilizer of both on and off‐farm origin) are by far the most common types, accounting for 59% and 27% of all farms respectively. Specialized semi‐extensive systems also show the highest protein and nutrient (N and P) use efficiencies, and among the highest labour use efficiency. Super‐intensive cage farms are less efficient in nutrient and labour use, but provide very high returns to land and capital investment. On average, the aquaculture components of integrated agriculture– aquaculture systems are less nutrient, land, and labour efficient than specialized semi‐extensive systems. Integrated semi‐extensive systems (using organic fertilizers of on‐farm origin) are particularly inefficient across all indicators. Hence in practice, gains in overall resource use efficiency through on‐farm integration with agricultural production are constrained by the relative inefficiency of the aquaculture subsystems on integrated farms. Although such systems can likely be improved, integration as such is not a panacea to increasing resource use efficiency. Wide variation in resource use efficiency within all systems indicates potential for substantial efficiency gains through improved management regardless of the fundamental choice of system. 相似文献
179.
Jean-Pierre Allais Michel Barbier 《Plant foods for human nutrition (Dordrecht, Netherlands)》1968,16(1-4):215-222
Résumé Nous avons obtenu avec un rendement acceptable des échantillons de -sitostérol purs par le procédé suivant: la double liaison en 22 d'un propionate de stigmastérol de pureté 95% est hydrogénée en présence de Pd/C. Le propionate de -sitostérol formé est isolé par chromatographie préparative sur couche mince d'alumine imprégnée de nitrate d'argent.Nous avons contrôlé la pureté du produit obtenu par spectrométrie de masse.
Note de laboratoire 相似文献
Summary Samples of pure -sitosterol have been obtained with a satisfactory yield by the following method.The double linkage in 22 of a stigmasterol propionate of 95% purity is hydrogenated in the presence of Pd/C. The -sitosterol propionate is isolated by preparatory thin layer chromatography on silver nitrate impregnated aluminium.The purity of the product has been verified by mass spectrometry.
Zusammenfassung Wir erhielten mit annehmbarem Wirkungsgrad Muster von reinem -Sitosterin nach folgender Methode:In Gegenwart von Pd/C wird die Doppelbindung bei 22 eines Stigmasterin-Propionates mit 95%-er Reinheit hydriert. Das gebildete -Sitosterin-propionat wird durch präparative DC auf mit Silbernitrat imprägnierter Aluminiumoxidschicht isoliert.Die Reinheit des erhaltenen Produktes wurde mit dem Massenspektrometer geprüft.
Note de laboratoire 相似文献
180.
高纯度茶氨酸的合成与特性(英文) 总被引:5,自引:0,他引:5
YAN Shou He Jean-Pierre DUFOUR MarcMEURENS 《茶叶科学》2003,23(2):99-104
报道了一种改进的茶氨酸(γ-谷酰基乙胺)的合成方法,包括L-谷氨酸的去氢成为吡咯烷酮羟酸(PCA),然后再加纯的乙胺(99%,气-液)反应,得率92.6%,再在84%乙醇溶液中重结晶后,高纯度茶氨酸(A型) 的得率37.4%。其结晶在透视和扫描电镜下呈长方形棱柱,具丝光状。A型茶氨酸的融点为224℃。B型茶氨酸从L-PCA合成,为甘蓝叶状,边缘呈波浪型,融点217—218℃。用HPLC分析证明,A和B型茶氨酸是混合异构体,A型含47.9%的L-茶氨酸,B型含90.9%的L-茶氨酸,100%的L-茶氨酸的旋光度(á)为+8.57。 相似文献