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121.
122.
DR Smith PJ Fedorka-Cray R Mohan KV Brock TE Wittum PS Morley KH Hoblet LJ Saif 《Canadian Metallurgical Quarterly》1998,59(8):986-993
OBJECTIVE: To identify exposures to etiologic agents and to identify characteristics that could explain risk of disease for adult cattle in herds affected by winter dysentery (WD). ANIMALS: 229 lactating and nonlactating adult cattle (125 case and 104 control cattle) selected from 12 dairy herds. PROCEDURE: A case-control study, using multivariate conditional logistic regression and controlling for herd effects, was used to develop a model for risk factors associated with disease for each cow. RESULTS: Likelihood of developing disease increased as the ELISA value for bovine coronavirus (BCV) antigen detectable in feces increased (odds ratio [OR] = 2.94 for each 0.100 increase in BCV antigen ELISA value). Pregnant cattle were less likely to develop WD, compared with nonpregnant herdmates. Cows with high acute BCV antibody titers that seroresponded had greater odds of developing disease, compared with seroresponding cows with low acute titers. However, among those cows that did not serorespond, high acute antibody titers were associated with lower odds of developing the disease. CONCLUSION: In herds affected by WD, ill cows were more likely to shed detectable amounts of BCV antigen in their feces, and pregnancy appeared to protect cattle from the disease. The measured interaction between BCV seroresponse and acute BCV antibody titer may be evidence of an immunopathologic condition, but could also have been attributable to dynamics of the ELISA or study design. CLINICAL RELEVANCE: Factors that explained a cow's risk for illness within WD-affected herds may have been surrogate measures for that cow's nonspecific and BCV-specific immune profile. 相似文献
123.
The paper gives the results of measuring the temperatures of the attainable superheat of some liquids that are thermally unstable at these temperatures. The technique of heating a thin wire probe placed into a liquid under study with electric-current pulses has been used. The length of pulses is from 10–5 to 10–3 s, which corresponds to a heating rate of 105 to 108 K·s–1. The influence of a chemical reaction in the liquid phase on the temperature of the attainable superheat has been considered. In particular, it has been shown that boiling initiated by an elementary act of an exothermic chemical reaction is of a low probability. A method of calculating the temperature of the attainable superheat of thermally unstable liquids under conditions of quick heating has been developed. A method for the determination of the kinetic parameters of thermal decomposition from the measurements of the temperature of the attainable superheat is discussed. 相似文献
124.
125.
Several recent studies have reported that there is an imbalance of increased oxidant status and decreased antioxidant system in women with preeclampsia and that factor might contribute to the pathogenesis of the disease. The following study examined blood levels of some of the antioxidants (glutathione, glutathione-peroxidase and -SH groups) as markers of lipid peroxidation in women with preeclampsia compared with normal gestation. Blood levels of these antioxidants were found significantly decreased in women with preeclampsia, which allowed us to speculate that there were abnormally increased levels of lipid peroxides. We believe that lipid peroxides are toxic compounds that damage endothelial cells, increase peripheral vasoconstriction and increase thromboxane synthesis and decrease prostacyclin synthesis. We consider that lipid peroxides are not the cause but the effect of oxidative stress induced by ischaemic placenta and leukocytes activation, so the contribute but not induce pathogenesis in preeclampsia. 相似文献
126.
PG Tarazov VK Ryzhkov VN Polysalov KV Prozorovski? AA Polikarpov 《Canadian Metallurgical Quarterly》1998,11(1):55-9; discussion 59-60
BACKGROUND: We evaluated the safety and efficacy of transurethral electrovaporization of the prostate (TVP) as a new alternative treatment for patients with benign prostatic hyperplasia. METHODS: A total of 22 patients with symptomatic benign prostatic hyperplasia, including 4 with urinary retention, underwent TVP. If enough of a cavity was not created after 60 minutes of vaporization, transurethral resection of the prostate (TURP) was performed successively. International Prostate Symptom Score (I-PSS) with quality-of-life index, maximum flow rate, and postvoid residual volume were measured at baseline and at 2 weeks, 1, 3, and 6 months. A pressure-flow study was performed at baseline and at 3 or 6 months after surgery. RESULTS: TURP was required in 10 of 22 patients. At 6 months, mean I-PSS decreased from 20.0 to 5.2, quality-of-life index decreased from 4.6 to 1.1, mean maximum flow rate increased from 6.9 to 16.7 mL/s, and postvoid residual volume decreased from 152 to 32 mL. Detrusor pressure at maximum flow decreased from 108 to 39 cm H2O, with a significant relief of bladder outlet obstruction in 93% of the patients. Mean decrease in hematocrit was 4.4%, and in serum sodium, 4.8 mEq/L. None of the patients required transfusions or had TUR syndrome. A urethral stricture and a severe stress incontinence developed in 1 patient. CONCLUSION: TVP seems to be a safe and effective alternative to a standard TURP associated with fewer intraoperative complications. Although preliminary clinical results have been promising, further study is necessary to establish long-term efficacy and safety of this procedure. 相似文献
127.
NB Ampilova IIa Bereznaia KV Grachev EIa Gurevich EV Strakhovich 《Canadian Metallurgical Quarterly》1996,92(6):20-23
An algorithm and a personal computer program for automatic distinguishing between EEC records containing evoked and no potentials, based on the detected invariants reflecting experts' experience in evoked potential analysis have been developed. The efficiency of the programme (its high accuracy and speed, low volume) has been demonstrated in the system for automatic determination of the hearing level by long-latent evoked potentials. It is easily modifiable to identify evoked potentials from other modalities (visual, somatosensory ones) in the systems using the traditional and/or up-to-date computerized EEC equipment. 相似文献
128.
KV Iserson 《Canadian Metallurgical Quarterly》1998,16(3):483-484
Spontaneous intracranial hypotension due to a spinal cerebrospinal fluid (CSF) leak is a rare but increasingly recognized cause of postural headaches. The exact cause of these CSF leaks often remains unknown. The authors treated a 32-year-old man with a unique cause of spontaneous intracranial hypotension. He suffered an excruciating headache that was exacerbated by his being in an upright position. The results of four-vessel cerebral angiography were negative; however, magnetic resonance (MR) imaging of the brain revealed pachymeningeal enhancement and hindbrain herniation. A presumptive diagnosis of spontaneous intracranial hypotension was made. Myelography revealed extrathecal contrast material ventral to the cervical spinal cord as well as an unusual midline bone spur at C5-6. The patient's symptoms did not resolve with the application of epidural blood patches, and he subsequently underwent an anterior approach to the C5-6 spur. After discectomy, a slender bone spur that had pierced the thecal sac was found. After its removal, the dural rent was closed using two interrupted prolene sutures. The patient was discharged home 2 days later. On follow up his symptoms had resolved, and on MR imaging the pachymeningeal enhancement had resolved and the cerebellar herniation had improved slightly. 相似文献
129.
In this paper, the problem of local approximate output regulation is considered. The presented results answer the question: given a controller solving the local approximate output regulation problem, how to estimate the set of initial conditions for which approximate output regulation occurs. The results are illustrated by a disturbance rejection problem for the TORA system. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
130.
I. P. Raevsky A. N. Pavlov E. I. Bondarenko V. G. Poltavtsev A. P. Nesterenro 《Ferroelectrics Letters Section》1990,11(2):47-52
The PTCR effect in ferroelectrics with the diffuse phase transition BaSrNb2O6 (BSN) and Na0.5Bi0.5TiO3 (NBT) has some peculiarities: the δ(T) anomaly in BSN is observed below the Curie point, in NBT it doesn't coincide with the anomalies of other electrophysical and optical properties and shows an anomalously large temperature hysteresis. These peculiarities may be explained by the diffuseness of spontaneous polarization temperature dependence. Besides in NBT the percolation effects are of importance. 相似文献