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排序方式: 共有400条查询结果,搜索用时 23 毫秒
111.
Nwadike BS Wilson LP Stone EA 《Journal of the American Veterinary Medical Association》2000,217(12):1862-1865
A 2-year-old Himalayan cat was examined because of 4 days of vomiting, lethargy; and anorexia. The cat had undergone hysterectomy and removal of left ovarian remnants 5 days earlier. Results of laboratory testing and excretory urography were consistent with uremia and bilateral ureteral obstruction. Nephrostomy catheters were placed to drain urine and allow time for physiologic diuresis prior to definitive repair. During the next 2 days, the cat's physiologic status improved greatly. The cat underwent exploratory surgery, and both ureters were found to be ligated. The healthy proximal portions of the ureters were implanted into the bladder. Six months after surgery, the cat was doing well, and excretory urography demonstrated that both ureters were patent. Bilateral obstruction of the ureters is a life-threatening condition that can be difficult to correct in cats. Placement of nephrostomy catheters allows time for improvement in the cat's physiologic status prior to the protracted anesthesia time needed for surgical repair of the ureters. 相似文献
112.
Hereford x Angus cows (n = 36; initial wt = 568+/-59 kg) were used to evaluate effects of undegradable intake protein (UIP) supplementation on forage utilization and performance of beef cows fed low-quality hay. Treatments were control (unsupplemented) or one of three protein supplements. Supplements were fed at 1.3 kg DM/d and included UIP at low, medium, or high levels (53, 223, or 412 g UIP/kg supplement DM, respectively). Supplements were formulated to be isocaloric (1.77 Mcal NEm/kg) and to contain equal amounts of degradable intake protein (DIP; 211 g DIP/kg supplement DM). Intake of forage was measured daily during six 7-d collection periods, which approximated mo 7, 8, and 9 of gestation and mo 1, 2, and 3 of lactation. Prairie hay (5.8% CP) was offered daily for ad libitum consumption. Cows were weighed and condition-scored on d 7 of each period. Supplemented cows had greater (P = .01) total organic matter intake (g/kg BW) compared with control animals during gestation. Forage organic matter intake (g/kg BW) was greater (P< or =.02) for control cows than for supplemented cows during lactation. Digestion of OM and NDF was lower (P<.10) for control than for supplemented cows. Body weight of supplemented cows was greater (P = .01) than that of control cows on four of six weigh dates. Supplemental UIP did not affect (P> .10) cow body weight or condition score. Body condition scores of supplemented cows were higher (P = .02) during mo 9 of gestation and during mo 3 of lactation compared with controls. Reproductive performance was similar (P>.10) among treatment groups, and there were few differences in calf performance. These data were interpreted to suggest that supplemental protein can increase total tract OM and NDF digestion by beef cows and increase body weight. Increasing the level of UIP in the supplement had little effect on forage utilization or animal performance. 相似文献
113.
Costa JF Kiperstok AC David JP David JM Giulietti AM de Queiroz LP dos Santos RR Soares MB 《Fitoterapia》2007,78(7-8):510-514
Ethyl acetate and chloroform extracts from aerial parts of Portulaca werdermannii and P. hirsutissima were tested in lymphoproliferation assays and axenic cultures of Leishmania amazonensis and Trypanosoma cruzi. Both extracts of P. werdermannii and P. hirsutissima had a potent inhibitory activity on lymphocyte proliferation. On the contrary, only the chloroformic extract of both plants inhibited L. amazonensis growth, without effect on T. cruzi cultures. These results indicate these Portulaca species as potential sources of new active molecules for the treatment of leishmaniasis and immune-mediated pathologies. 相似文献
114.
A method for the isolation of six isoflavones (genistein, genistin, daidzein, daidzin, glycitein and glycitin) with high purity from Semen sojae praeparatum, a famous traditional Chinese medicine, by preparative HPLC is described. 相似文献
115.
An infrared radiometer system has been developed that can alert a pilot of an aircraft 2 to 9 minutes in advance of an encounter with clear air turbulence. The time between the warning and the clear air turbulence event varies with the flight altitude of the aircraft. In turbulence-free areas, the incidence of false alarms is found to be less than one in 3.4 hours of flight time compared to less than one per 10 hours of flight time in areas with turbulence. 相似文献
116.
Voegel LP 《Science (New York, N.Y.)》2002,295(5555):625
117.
118.
Doh YJ van Dam JA Roest AL Bakkers EP Kouwenhoven LP De Franceschi S 《Science (New York, N.Y.)》2005,309(5732):272-275
Nanoscale superconductor/semiconductor hybrid devices are assembled from indium arsenide semiconductor nanowires individually contacted by aluminum-based superconductor electrodes. Below 1 kelvin, the high transparency of the contacts gives rise to proximity-induced superconductivity. The nanowires form superconducting weak links operating as mesoscopic Josephson junctions with electrically tunable coupling. The supercurrent can be switched on/off by a gate voltage acting on the electron density in the nanowire. A variation in gate voltage induces universal fluctuations in the normal-state conductance, which are clearly correlated to critical current fluctuations. The alternating-current Josephson effect gives rise to Shapiro steps in the voltage-current characteristic under microwave irradiation. 相似文献
119.
van der Wiel WG De Franceschi S Fujisawa T Elzerman JM Tarucha S Kouwenhoven LP 《Science (New York, N.Y.)》2000,289(5487):2105-2108
We observe a strong Kondo effect in a semiconductor quantum dot when a small magnetic field is applied. The Coulomb blockade for electron tunneling is overcome completely by the Kondo effect, and the conductance reaches the unitary limit value. We compare the experimental Kondo temperature with the theoretical predictions for the spin- 12 Anderson impurity model. Excellent agreement is found throughout the Kondo regime. Phase coherence is preserved when a Kondo quantum dot is included in one of the arms of an Aharonov-Bohm ring structure, and the phase behavior differs from previous results on a non-Kondo dot. 相似文献
120.
Observing systems in nature has inspired humans to create technological tools that allow us to better understand and imitate biology. Biomimetics, in particular, owes much of its current development to advances in materials science and creative optical system designs. New investigational tools, such as those for microscopic imaging and chemical analyses, have added to our understanding of biological optics. Biologically inspired optical science has become the emerging topic among researchers and scientists. This is in part due to the availability of polymers with customizable optical properties and the ability to rapidly fabricate complex designs using soft lithography and three-dimensional microscale processing techniques. 相似文献