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排序方式: 共有314条查询结果,搜索用时 11 毫秒
161.
Marcio A. Mazutti Giovani Zabot Gabriela Boni Aline Skovronski Débora de Oliveira Marco Di Luccio J. Vladimir Oliveira Maria Isabel Rodrigues Helen Treichel Francisco Maugeri 《Biomass & bioenergy》2010,34(5):780-786
This work reports hot-air convective drying of thin-layer fermented and non-fermented sugarcane bagasse. For this purpose, experiments were carried out in a laboratory-scale dryer assessing the effects of solid-state fermentation (SSF) on the drying kinetics of the processing material. The fermented sugarcane bagasse in SSF was obtained with the use of Kluyveromyces marxianus NRRL Y-7571. Drying experiments were carried out at 30, 35, 40 and 45 °C, at volumetric air flow rates of 2 and 3 m3 h?1. The ability of ten different thin-layer mathematical models was evaluated towards representing the experimental drying profiles obtained. Results showed that the fermented sugarcane bagasse presents a distinct, faster drying, behavior from that verified for the non-fermented material at the same conditions of temperature and volumetric air flow rate. It is shown that the fermented sugarcane bagasse presented effective diffusion coefficient values of about 1.3 times higher than the non-fermented material. A satisfactory agreement between experimental data and model results of the thin-layer drying of fermented and non-fermented sugarcane bagasse was achieved at the evaluated experimental conditions. 相似文献
162.
163.
Parrish T.B. Schaeffer A. Catanese M. Rogel M.J. 《IEEE engineering in medicine and biology magazine》2005,24(2):35-40
Functional magnetic resonance imaging (fMRI) is an ideal method to noninvasively explore the whole brain for cortical activation related to acupuncture. The results from this study demonstrate that fMRI can identify specific cortical regions associated with acupuncture stimulation. The choice of acupuncture stimulation using visual or auditory points simplifies the interpretation of the results because the anatomic correlates are well defined. The magnitude and extent of the activations were different for the auditory and the visual stimulation; this may be due to the relative potency of the acupuncture points used, the overall imbalance associated with these systems, and the interpretation of the acupuncture point by the acupuncturist. Nevertheless, these data reflect significant blood-flow changes within the appropriate regions of the brain in response to stimulation of acupuncture points in the lower leg. With the appropriate experimental design, a clearer understanding of the neural substrate associated with acupuncture is likely to provide considerable insights into acupuncture treatment. This type of scientific approach to investigating and validating alternative medicine techniques is critical for the widespread acceptance of these methods. 相似文献
164.
S Bastuji-Garin A Schaeffer P Wolkenstein B Godeau C Carville I Durand-Zaleski M Meignan 《Canadian Metallurgical Quarterly》1998,114(6):1551-1555
OBJECTIVE: The purpose of this study was to determine the prevalence and nature of a horizontal cleft in the posterior aspect of Hoffa's infrapatellar fat pad and to show pathologic processes involving this cleft. MATERIALS AND METHODS: Fifty consecutive MR imaging examinations of the knee were evaluated for the presence and appearance of a cleft in the infrapatellar fat pad. Examples of abnormalities involving the cleft were collected from additional MR studies. MR imaging, gross dissection, and histologic examination of a cadaveric knee were also performed to evaluate the anatomy and histology of the cleft. RESULTS: The cleft in the infrapatellar fat pad was revealed on MR imaging in 45 of 50 knees and had a variable shape, either linear (82%), pipe-shaped (7%), or globular-shaped (11%). Joint effusion or anterior cruciate ligament tear did not affect the appearance of the cleft. The cleft was located anterior to the distal insertion of the anterior cruciate ligament on the tibia. At gross dissection of the cadaveric knee, the roof of the cleft was formed by the ligamentum mucosum (infrapatellar plica), and the cleft was lined with synovium. The prospective evaluation of additional MR imaging examinations of the knee revealed pathologic entities of the cleft such as ganglion cysts, loose bodies, nodular synovitis, and amyloid. CONCLUSION: A horizontal cleft located in the posterior aspect of the infrapatellar fat pad is a common and normal MR imaging finding with a prevalence of 90%. The horizontal cleft is lined with synovium and its roof is formed by the ligamentum mucosum (infrapatellar plica). This cleft communicates with the knee joint. A distended cleft can form a prominent recess mimicking pathologic processes; conversely, disorders can arise in the cleft. 相似文献
165.
JD Engel TM Kuzel MC Moceanu MG Oefelein AJ Schaeffer 《Canadian Metallurgical Quarterly》1998,52(5):778-784
BACKGROUND/AIMS: Correlations between serum levels of soluble tumor necrosis factor receptors p55 (TNFsRp55) and Child Pugh index have previously been reported in alcoholic patients with cirrhosis. We have undertaken this study to improve understanding of the role of tumor necrosis factor soluble receptors (TNFsRs) in alcoholic liver disease. METHODS: One hundred and two patients with alcoholic liver disease of various severity (23 pure steatosis, 22 fibrosis, seven acute alcoholic hepatitis without cirrhosis, 12 cirrhosis without acute alcoholic hepatitis, 14 cirrhosis with mild acute alcoholic hepatitis and 24 cirrhosis with severe acute alcoholic hepatitis) were studied. Blood was collected on EDTA and plasma was tested for TNFsR concentrations using ELISA assays. RESULTS: Plasma levels of TNFsRp55 and p75 increased progressively with the severity of liver disease, reaching a maximum in cirrhotic patients with severe acute alcoholic hepatitis. Plasma levels of TNFsRp55 in patients with fibrosis and of TNFsRp75 in patients with acute alcoholic hepatitis without cirrhosis were already higher than in healthy controls. In cirrhotic patients with or without acute alcoholic hepatitis TNFsRp55 and p75 were significantly increased compared with controls. In cirrhotic patients, plasma levels of TNFsRp55 correlated positively with all parameters of liver injury, whereas the TNFsRp75/ TNFsRp55 ratio correlated negatively. In cirrhotic patients with severe acute alcoholic hepatitis, the TNFsRp75/TNFsRp55 ratio was significantly lower than in all other groups. In cirrhotic patients with severe acute alcoholic hepatitis treated by prednisolone, the decrease in TNFsRp55 plasma levels between day 1 and day 15 was significantly more important in patients still alive at 2 months than in patients who died within 2 months. CONCLUSIONS: These results show that the expression of TNF-soluble receptors (TNFsRs) participates in the early phases of the alcoholic liver disease and that the TNFsRp75/TNFsRp55 ratio and plasma levels of TNFsRp55 may help to determine the diagnosis and the prognosis of severe acute alcoholic hepatitis in cirrhotics. 相似文献
166.
Agenor Gomes Pinto Garcia Alexandre S. Szklo Roberto Schaeffer Michael A. McNeil 《Energy Policy》2007
The first regulation of the “Energy Efficient Act” for electric motors, launched in 2002, established two sets of minimum efficiency performance standards (MEPS), for ‘standard’ (mandatory) and ‘high efficiency’ (voluntary) motors. An updated regulation, from the end of 2005 (Edict 553/2005), established the previous high-efficiency MEPS as mandatory for all motors in the Brazilian market. This paper analyses the consequences of this new regulation, which is foreseen to take effect in 2010. These new Brazilian MEPS are compatible with those implemented in other countries. The cost–benefit analysis, considered for different scenarios for industrial consumers, showed that motor substitution (from standard to high efficiency) is generally advantageous. A sample of nine thousand industrial motors has been used, with measured operation in actual conditions, to analyze the investment cost–benefit in three different scenarios. This analysis also demonstrated the benefit of motor substitution, with an average MWh cost from 20 to 35 US$, and with only a few substitutions presenting an unfavorable cost–benefit relationship to the user. We assess that Edict 553 avoided construction of 350 MW of hydroelectric capacity. Nevertheless, since the cost of conserved energy for this energy-saving measure is generally below the marginal cost of expansion of the Brazilian electric system, we propose mechanisms to share investment costs among the society as a whole, including demand-side bidding. 相似文献
167.
B. A. Brice Margaret L. Swain B. B. Schaeffer W. C. Ault 《Journal of the American Oil Chemists' Society》1945,22(9):219-224
Summary Existing ultraviolet spectrophotometric methods have been modified for application primarily to the detection and estimation
of low proportions of conjugated and nonconjugated unsaturated constituents in fats, oils, and soaps. The method is applicable
also to fatty materials having high proportions of these constituents.
Modifications include corrections for absorption by interfering substances, use of alkaline glycerol as an isomerization medium
in the analytical procedure, and correction of absorption data on the isomerized product for absorption by conjugated constituents
in the material before isomerization.
The presence of small proportions of highly unsaturated conjugated and nonconjugated compounds is established in lards, tallows,
tallow soaps, and highly purified esters and acids. Tall oil fatty acids are shown to contain approximately 10% of conjugated
diene acids and a small amount of linolenic acid.
One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, United
States Department of Agriculture. 相似文献
168.
U Freund RW Carlson RC Schaeffer V Puri MH Weil 《Canadian Metallurgical Quarterly》1976,143(5):709-716
An inventory of hemodynamic and respiratory measurements was obtained in two patients with acute respiratory failure syndrome prior to and during venoarterial extracorporeal membrane oxygenation for study of oxygen transport. As the inspired oxygen concentration fraction was reduced from 1.0 to 0.5 and paO2 was increased from less than 50 to physiologic ranges during extracorporeal membrane oxygenation, tachycardia and pulmonary hypertension were reversed. Total oxygen transport was reduced rather than increased. Oxygen consumption and oxygen extraction were not altered during extracorporeal membrane oxygenation. However, a striking reduction was observed in cardiac output. After reversal of anoxemia, the total of the cardiac output of the patient and the extracorporeal membrane oxygenation flow were less than the cardiac output of the patient prior to extracorporeal membrane oxygenation. These observations provide evidence that the beneficial effects of extracorporeal membrane oxygenation stem, at least in part, from a reduction of the work load on the heart. Since high cardiac output failure is observed during progression of adult respiratory distress syndrome, mechanical support of circulation during extracorporeal membrane oxygenation may be of primary therapeutic benefit. 相似文献
169.
Pregnancy has a negative impact on milk production in dairy cattle. Estimates of the effects of pregnancy are required in genetic evaluation models. Test-day records of Ayrshire, Jersey, Brown Swiss, and Guernsey breeds were analyzed phenotypically for the effect of pregnancy using 4 different models. Milk, fat, and protein yields were analyzed separately. The first model used a fourth-order Legendre polynomial regression on days in milk within classes of 10 d open. The second model fitted stage of pregnancy within days open classes to investigate the possible interaction between lactation stage and gestation stage. The third model included a fourth-order Legendre polynomial regression on days pregnant. In the fourth model, test-day records were divided into stage of pregnancy classes. Given that the effect of pregnancy was significant for all models, and that the adjusted R-squared values were consistent across the models, implying that the models for each trait fitted equally well within breeds, models were therefore compared based on the practicality of the results. Analysis of the first model indicated that milk production for cows with ≤180 d open tended to have low yields in the last part of lactation. Cows with longer days open, however, had proportionally higher milk yield throughout lactation, suggesting a possible confounding effect of production level with days open effects. Results from the analysis involving the second model illustrated that there was no apparent interaction between lactation stage and gestation stage. Results from the third and fourth models showed that milk and fat yields began to decline after about 4 mo of pregnancy for all breeds, and protein yield began to decline after about 2 mo of pregnancy for all breeds. A lack of records during the final 60 d of pregnancy (the typical dry period) severely limited the third model, as pregnancy effects could not be estimated accurately. This problem was lessened, however, with the fourth (stage of pregnancy) model, because test-day records for cows ≥210 d pregnant were grouped together, allowing for a moderate number of test-day records in the final class of days pregnant. Because the stage of pregnancy model showed a decline in production that increased as gestation progressed, and because there was not a lack of test-day records at the end of pregnancy, the fourth model provided the most realistic estimate of the effect of pregnancy on milk production. Further investigation is needed into the incorporation of stage of pregnancy effects into genetic evaluations. 相似文献
170.
A Etter DF Cully KK Liu B Reiss DK Vassilatis JM Schaeffer JP Arena 《Canadian Metallurgical Quarterly》1999,72(1):318-326
Glutamate-gated chloride channels have been described in nematodes, insects, crustaceans, and mollusks. Subunits from the nematode and insect channels have been cloned and are phylogenetically related to the GABA and glycine ligand-gated chloride channels. Ligand-gated chloride channels are blocked with variable potency by the nonselective blocker picrotoxin. The first two subunits of the glutamate-gated chloride channel family, GluClalpha and GluClbeta, were cloned from the free living nematode Caenorhabditis elegans. In this study, we analyze the blockade of these novel channels by picrotoxin. In vitro synthesized GluClalpha and GluClbeta RNAs were injected individually or coinjected into Xenopus oocytes. The EC50 values for picrotoxin block of homomeric GluClalpha and GluClbeta were 59 microM and 77 nM, respectively. Picrotoxin block of homomeric GluClbeta channels was promoted during activation of membrane current with glutamate. In addition, recovery from picrotoxin block was faster during current activation by glutamate. A chimeric channel between the N-terminal extracellular domain of GluClalpha and the C-terminal membrane-spanning domain of GluClbeta localized the higher affinity picrotoxin binding site to the membrane-spanning domains of GluClbeta. A point mutation within the M2 membrane-spanning domain of GluClbeta reduced picrotoxin sensitivity >10,000-fold. We conclude that picrotoxin blocks GluCl channels by binding to a site accessible when the channel is open. 相似文献