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排序方式: 共有1977条查询结果,搜索用时 273 毫秒
991.
992.
993.
Systemic dry cow therapy--a preliminary report 总被引:1,自引:0,他引:1
Efficacy of three different treatment regimens in the elimination and prevention of Staphylococcus aureus intramammary infection was studied in 106 dry cow periods. At drying off, norfloxacin nicotinate was given subcutaneously to 44 cows at 10 mg/kg, oxytetracycline-HCl was administered intramuscularly to 18 cows at 20 mg/kg, 500 mg cephapirin benzathine were infused into each udder quarter of 21 cows, and a group of 23 cows served as an untreated control. Number of existing Staphylococcus aureus intramammary infections was reduced only in the norfloxacin nicotinate treatment group. New infection rate appeared lower in the two systemic treatment groups. The percentage of infected quarters remained the same throughout the dry period in the norfloxacin treatment group but number of infected quarters increased by 33 to 85% (significant in the cephapirin group) in the other groups. Minimal inhibitory concentration of the drugs for 57 S. aureus isolates was determined. Isolates were sensitive to norfloxacin and cephapirin and moderately sensitive to oxytetracycline. Results suggest that systemic dry cow therapy using norfloxacin nicotinate, which possesses large distribution volume, long half-life, and is highly active against the pathogen involved, was more effective than the other treatments. 相似文献
994.
T Winkler HS Sharma E St?lberg RD Badgaiyan P Alm J Westman 《Canadian Metallurgical Quarterly》1998,14(1-3):131-139
The possibility that nitric oxide is somehow involved in the early bioelectrical disturbances following spinal cord injury in relation to the later pathophysiology of the spinal cord was examined in a rat model of spinal cord trauma. A focal trauma to the rat spinal cord was produced by an incision of the right dorsal horn of the T 10-11 segments under urethane anaesthesia. The spinal cord evoked potentials (SCEP) were recorded using epidural electrodes placed over the T9 and T12 segments of the cord following supramaximal stimulation of the right tibial and sural nerves in the hind leg. Trauma to the spinal cord significantly attenuated the SCEP amplitude (about 60%) immediately after injury which persisted up to 1 h. However, a significant increase in SCEP latency was seen at the end of 5 h after trauma. These spinal cord segments exhibited profound upregulation of neuronal nitric oxide synthase (NOS) immunoreactivity, and the development of edema and cell injury. Pretreatment with a serotonin synthesis inhibitor drug p-chlorophenylalanine (p-CPA) or an anxiolytic drug diazepam significantly attenuated the decrease in SCEP amplitude, upregulation of NOS, edema and cell injury. On the other hand, no significant reduction in SCEP amplitude, NOS immunolabelling, edema or cell changes were seen after injury in rats pretreated with L-NAME. These observations suggest that nitric oxide is somehow involved in the early disturbances of SCEP and contribute to the later pathophysiology of spinal cord injury. 相似文献
995.
SS Winkler JE Holden JF Sackett DC Flemming SC Alexander 《Canadian Metallurgical Quarterly》1977,12(1):19-20
Uptake of D-glucose anomers by isolated rat retina was studied. After 3 min incubation at 37 degrees C in the presence of alpha or beta anomer (750 mug/ml), a significantly greater uptake (1.32 mg/g wet tissue) of beta-anomer was observed compared with that of alpha-D-glucose (1.11 mg/g wet tissue). This result and other data suggest that the carrier for D-glucose transport in the retina prefers the beta-anomer stereospecifically. 相似文献
996.
997.
998.
Kl. Winkler 《Molecular nutrition & food research》1971,15(5):597-597
999.
Pumera M Wang J Opekar F Jelínek I Feldman J Löwe H Hardt S 《Analytical chemistry》2002,74(9):1968-1971
A microfabricated electrophoresis chip with an integrated contactless conductivity detection system is described. The new contactless conductivity microchip detector is based on placing two planar sensing aluminum film electrodes on the outer side of a poly(methyl methacrylate) (PMMA) microchip (without contacting the solution) and measuring the impedance of the solution in the separation channel. The contactless route obviates problems (e.g., fouling, unwanted reactions) associated with the electrode-solution contact, offers isolation of the detection system from high separation fields, does not compromise the separation efficiency, and greatly simplifies the detector fabrication. Relevant experimental variables, such as the frequency and amplitude of the applied ac voltage or the separation voltage, were examined and optimized. The detector performance was illustrated by the separation of potassium, sodium, barium, and lithium cations and the chloride, sulfate, fluoride, acetate, and phosphate anions. The response was linear (over the 20 microM-7 mM range) and reproducible (RSD = 3.4-4.9%; n = 10), with detection limits of 2.8 and 6.4 microM (for potassium and chloride, respectively). The advantages associated with the contactless conductivity detection, along with the low cost of the integrated PMMA chip/detection system, should enhance the power and scope of microfluidic analytical devices. 相似文献
1000.
Holger Petersen 《Information Processing Letters》2002,81(2):75-79
We disprove a conjecture of López-Ortiz by showing that the Element Distinctness Problem for n numbers of size O(logn) can be solved in O(n2(logn)3/2(loglogn)1/2) steps by a nondeterministic one-tape Turing machine. Further we give a simplified algorithm for solving the problem for shorter numbers in time O(n2logn) on a deterministic one-tape Turing machine and a new proof of the matching lower bound. 相似文献