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581.
Astronomical instruments operating in the infrared-millimeter region often require internal sources for detector monitoring, instrument calibration, and health checking. We describe the design, modeling, and experimental evaluation of thermal emitters with a fast speed of response and low-power dissipation, suitable for the far-infrared-submillimeter region. The development of an internal illuminator for the Herschel Spectral and Photometric Imaging Receiver (SPIRE) satellite instrument is used as an example of the optimization of the design to meet particular requirements. A prototype illuminator design for SPIRE has been developed that, for a power dissipation of 1.5 mW, provides an equivalent blackbody temperature of 45 K with a 90% settling time of 220 ms.  相似文献   
582.
583.
In this paper, we propose an algorithm that, using the extended Kalman filter, solves the inverse problem of estimating the conductivity/resistivity distribution in electrical impedance tomography (EIT). The algorithm estimates conductivity/resistivity in a wide range. The purpose of this investigation is to provide information for setting and controlling air volume and pressure delivered to patients under artificial ventilation. We show that, when the standard deviation of the measurement noise level raises up to 5% of the maximal measured voltage, the conductivity estimates converge to the expected vector within 7% accuracy of the maximal conductivity value, under numerical simulations, with spatial a priori information. A two-phase identification procedure is proposed. A cylindrical phantom with saline solution is used for experimental evaluation. An abrupt modification on the resistivity distribution of this solution is caused by the immersion of a glass object. Estimates of electrode contact impedances and images of the glass object are presented.  相似文献   
584.
BACKGROUND: Auxiliary liver transplantation offers an alternative method to conventional transplantation in acute liver failure. It is especially challenging for children because lifelong immunosuppression may be avoided. However, experience with this procedure is rare and there is controversy about whether to place the graft orthotopically or heterotopically. METHODS: We present the case of a 3-year-old boy with acute liver failure due to non-ABC hepatitis complicated by aplastic anemia who underwent auxiliary liver transplantation. Segments 2 and 3 of the graft were implanted heterotopically in the right lower abdomen. RESULTS: Good liver function was immediately restored. Aplastic anemia resolved 3 weeks after transplantation. Immunosuppressive therapy was discontinued after 14 months, and the graft was left to atrophy. Thirty-nine months after transplantation the boy is alive and well with normal liver function tests and normal blood cell counts. CONCLUSIONS: Heterotopic auxiliary liver transplantation allowed recovery of the native liver in a child with acute liver failure and aplastic anemia due to non-ABC hepatitis.  相似文献   
585.
Summary The polymerization of hexachlorocyclotriphosphazene (trimer) is studied in different solvents. A soluble low molecular weight polymer is obtained when benzene is the solvent, a highly cross-linked polymer when cyclohexane is the solvent, and a mixture of soluble and insoluble polymers results when the solvent is chlorobenzene. The conversion-concentration curve for the trimer shows a dependence of the amount of soluble and insoluble polymer formed on the trimer concentration. No polymerization took place when the solvent was toluene, nitrobenzene or THF, but a reaction between solvent and trimer was detected.  相似文献   
586.
The aim of this study was to determine for sardines (Sardina pilchardus) the effect of (i) chilling in ice and water in small expanded polystyrene boxes during distribution and in ice thereafter and (ii) chilling in ice and water for the entire storage period. These storage methods were compared with storage of the fish in ice in wooden boxes or in expanded polystyrene boxes. Three storage experiments were performed to take into account the variability in handling conditions and seasonality. There were significant (P < 0.05) differences in the results of some of the sensory, physical, chemical, and microbiological analyses performed that showed that the fish were of better quality when preserved in water and ice than when preserved in ice alone. The effects of dewatering of the fish after transport and subsequent storage in ice were also significantly different (P < 0.05) from those of storage in ice, with the former storage method resulting in better sensory and microbial indices. However, oxidative rancidity, as measured by thiobarbituric acid-reactive substances, was higher for the dewatered fish than for fish preserved in water and ice throughout the storage period. It is concluded that for sardines, storage in water and ice, either only during transport or throughout the storage period, can be useful as an alternative preservation method during distribution and retail sale.  相似文献   
587.
对于原棉纤维性能的深入了解有助于纺纱厂在挑选和管理纤维时做出更为优化的决策,乌斯特技术公司推出的USTERHVIMF100可帮助纺纱厂改善纤维选择和纤维管理,从而降低成本、提高利润和改善产品质量。  相似文献   
588.
The objective was to identify and sequence the sua gene (GenBank no. DQ232760; http://www.ncbi.nlm.nih.gov/genbank/) and detect Streptococcus uberis adhesion molecule (SUAM) expression by Western blot using serum from naturally S. uberis-infected cows in strains of S. uberis isolated in milk from cows with mastitis from geographically diverse areas of the world. All strains evaluated yielded a 4.4-kb sua-containing PCR fragment that was subsequently sequenced. Deduced SUAM AA sequences from those S. uberis strains evaluated shared >97% identity. The pepSUAM sequence located at the N terminus of SUAM was >99% identical among strains of S. uberis. Streptococcus uberis adhesion molecule expression was detected in all strains of S. uberis tested. These results suggest that sua is ubiquitous among strains of S. uberis isolated from diverse geographic locations and that SUAM is immunogenic.  相似文献   
589.
In cattle, proper rumen functioning and digestion are intimately linked to chewing behavior. Yet, high grain feeding impairs chewing activity, increasing the risk of subacute ruminal acidosis and dysfermentation. This study aimed to screen 9 different phytogenic compounds for their potential to modulate chewing activity, meal size, rumino-reticular short-chain fatty acids (SCFA), and pH during consumption in a first daily meal and shortly thereafter in cattle fed a grain-rich diet. Treatments were control (total mixed ration without phytogenic) or addition of a phytogenic compound at a low or high dose. Phytogenic compounds and doses (all in mg/kg) were angelica root (6.6 and 66), capsaicin (10 and 100), gentian root (6.6 and 66), garlic oil (0.3 and 3), ginger extract (40 and 400), L-menthol (6.7 and 67), mint oil (15.3 and 153), thyme oil (9.4 and 94), and thymol (5 and 50), for the low and high groups, respectively. Before the start of the screening experiment, cows were fed to reach subacute ruminal acidosis conditions, confirmed with the time of ruminal pH <5.8 being 655 ± 148.2 min/d. During the screening experiment, the treatments were offered in a controlled meal (2.5 kg of DM for 4 h) as part of the daily diet with 65% concentrate. Each treatment was tested in 4 of the 9 cannulated Holstein cows using an incomplete Latin square design. Ruminal and reticular fluids were sampled before and after each treatment, and data collected before the meal were used as covariates. Chewing and ruminal pH were monitored during the treatment, followed by 2 h of complete feed restriction, and then 4 h of ad libitum feed intake without phytogenic. Data showed that supplementation of angelica root tended to linearly increase rumination time immediately after the first meal when feed was restricted (27.3, 41.9, and 42.6 ± 5.99 min for control, low and high groups, respectively). Capsaicin increased eating time (43.6, 49.4, and 66.4 ± 4.93 min) during consumption but did not affect ruminal total SCFA or mean ruminal pH. Garlic oil reduced the concentration of reticular total SCFA (75.7, 71.3, and 60.1 mM) and tended to decrease ruminal acetate-to-propionate ratio (2.50, 1.78, and 1.87 ± 0.177) with no effect on ruminal pH. The L-menthol affected reticular total SCFA quadratically (76.1, 64.9, and 81.0 ± 4.22%), and ruminal pH responded quadratically when feed was reintroduced ad libitum (6.0, 6.3, and 6.1 ± 0.07). Mint oil did not affect chewing or total SCFA during consumption, but the low dose increased ruminal pH (6.5, 6.7, and 6.5 ± 0.08). Thyme oil tended to lower the severity of ruminal acidosis. Overall, phytogenic compounds demonstrated distinct dose-dependent effects to beneficially influence chewing behavior, modulate fermentation, and mitigate ruminal acidosis in dairy cows under a high-grain challenge diet.  相似文献   
590.
PURPOSE: To compare the initial comfort afforded by silicone hydrogel lenses (lotrafilcon A) versus the comfort afforded by conventional hydrogel lenses (etafilcon A) in extended wear (EW). DESIGN: Prospective, double-masked and randomized controlled trial. METHODS: Lotrafilcon A and etafilcon A contact lenses were eye randomly fitted on an EW basis for 7 days and nights in 20 subjects. A forced-choice subject preference questionnaire was made. Subjects were comfort, dryness, red eye and visual quality after night wear and at the end of the day. Subjective scored satisfaction (scale: 1-5) and lens preference were assessed. RESULTS: Lotrafilcon A proved more comfortable after night wear (60%, CI95% 38-82%) and at the end of the day (70%, CI95% 49-90%) than etafilcon A after night wear (10%, CI95% 0-23%, P<0.05) and at the end of the day (20%, CI95% 2-38%, P<0.05). The feeling of dryness was more marked with etafilcon A after night wear (50%, CI95% 27-72%) and at the end of the day (50%, CI95% 27-72%) than it was with lotrafilcon A (15%, CI95% 0%-31%) after night wear (P>0.05) and at the end of the day (25%, CI95% 5%-44%, P<0.05). General satisfaction with the lotrafilcon A lens was 3.65 points (CI95% 3-4.2) and with etafilcon A 2.95 points (CI95% 2.5-3.3, P<0.05). Eighty percent (CI95% 62%-98%) of subjects preferred lotrafilcon A (P<0.05) for EW. CONCLUSIONS: In EW, lotrafilcon A contact lenses were more comfortable and led to less dryness after night wear and at the end of the day than etafilcon A contact lenses.  相似文献   
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