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排序方式: 共有499条查询结果,搜索用时 15 毫秒
491.
Bioluminescence ATP monitoring as a surrogate marker for microbial load on hands and surfaces in the home 总被引:2,自引:0,他引:2
Larson EL Aiello AE Gomez-Duarte C Lin SX Lee L Della-Latta P Lindhardt C 《Food microbiology》2003,20(6):735-739
To evaluate the validity and reliability of adenosine triphosphate (ATP) monitoring as a surrogate marker for cleanliness, the kitchen table surface in 225 inner-city homes was sampled by microbiologic culture and by two types of biomass monitoring systems (HY-LiTEtrade mark 2 ATP System and HY-RiSE Colour Hygiene Test Strip, EM Science, Gibbstown, New Jersey, USA). A randomly selected hand of the homemaker (n = 225) was also cultured and sampled with the ATP monitoring system immediately after handwashing. Log microbial counts on hands ranged from 3.2 to 7.0 and from the table, 1.0 to 5.5. While the traditional ATP readings (HY-LiTE) and the color strips were significantly correlated (R = 0.18, P = 0.01), there was no significant correlation between the ATP monitor readings and the colony-forming units counts on either the hands (R = 0.03, P = 0.62) or the table (R = 0.04, P = 0.58). Such biomass measurements are not a substitute for quantitation of microbial load. 相似文献
492.
Raffaele Romano Lucia De Luca Alessandra Aiello Danilo Rossi Fabiana Pizzolongo Paolo Masi 《International Journal of Food Science & Technology》2022,57(6):3826-3837
This work investigated the extraction of bioactive compounds from citrus peels, an agri-food waste. Carbon dioxide (CO2), an eco-friendly solvent, was used under liquid and supercritical conditions to perform the extractions from orange, tangerine and lemon peels. The possibility of using ethanol as a cosolvent at small percentages up to 20% was also studied. The extraction yield, total polyphenolic content, individual polyphenolic profile, antiradical activity and volatile organic compounds of the extracts were evaluated. The highest yields were obtained when 20% ethanol was used as a cosolvent in both liquid (at 20 MPa and 20 °C) and supercritical (at 30 MPa and 60 °C) CO2 extraction. In addition, the extracts obtained with liquid CO2 + 20% ethanol showed the highest content of naringin (35.26, 44.05 and 19.86 mg g-1 in orange, tangerine and lemon peel extracts, respectively) and terpenes, in particular limonene. This type of extract also showed the highest antiradical activity (31.78–59.51 µmolTE g-1) as measured by both ABTS·+ and DPPH·. These findings show that the extraction with a liquid CO2 and ethanol mixture could be a valid alternative to traditional solvent extraction using 80% less organic solvent and producing extracts with high antiradical capacity and rich in volatile organic compounds. 相似文献
493.
Synchronization Techniques for Power Quality Instruments 总被引:1,自引:0,他引:1
Aiello M. Cataliotti A. Cosentino V. Nuccio S. 《IEEE transactions on instrumentation and measurement》2007,56(5):1511-1519
The measurement of voltage characteristics in power systems requires the accurate estimation of the power supply frequency and signal synchronization, even in the presence of disturbances. The authors developed and tested two innovative techniques for instrument synchronization. The first is based on signal spectral analysis techniques performed by means of the Chirp- transform analysis. The second is a phase-locked loop (PLL) software based on a time-domain coordinate transformation and an innovative phase-detection technique. To evaluate how synchronization techniques are adversely affected by the application of a disturbing influence, experimental tests were carried out, taking into account the requirements of the standards. The proposed techniques were compared with a standard hardware solution. In this paper, the proposed techniques are described, the experimental results are presented, and the accuracy specifications are discussed. 相似文献
494.
Luigia Carlucci Aiello Fabio Massacci 《Electronic Notes in Theoretical Computer Science》2003,55(1):51
Most approaches to formal protocol verification rely on an operational model based on traces of atomic actions. Modulo CSP, CCS, state-exploration, Higher Order Logic or strand spaces frills, authentication or secrecy are analyzed by looking at the existence or the absence of traces with a suitable property.We introduced an alternative operational approach based on parallel actions and an explicit representation of time. Our approach consists in specifying protocols within a logic language ( AL SP), and associating the existence of an attack to the protocol with the existence of a model for the specifications of both the protocol and the attack.In this paper we show that, for a large class of protocols such as authentication and key exchange protocols, modeling in AL SP is equivalent - as far as authentication and secrecy attacks are considered - to modeling in trace based models.We then consider fair exchange protocols introduced by N. Asokan et al. showing that parallel attacks may lead the trusted third party of the protocol into an inconsistent state. We show that the trace based model does not allow for the representation of this kind of attacks, whereas our approach can represent them. 相似文献
495.
LO Ohrnell R Br?nemark J Nyman P Nilsson P Thomsen 《Canadian Metallurgical Quarterly》1997,31(4):281-293
The present study reports on the late effects of increasing doses of radiation on the biomechanics of commercially pure titanium implants (fixtures) installed in the proximal tibia in 26 rats. Twelve weeks after various doses (10, 20, 30, and 35 Gy) of irradiation, the fixtures were inserted into rat tibiae, and after another eight weeks these were tested mechanically in vivo. Acute dose dependent skin reactions developed after all doses except 10 Gy, but most subsided within two to three weeks. There was a statistically significant reduction in torsion but the pull-out load was not significantly reduced for single doses up to 30 Gy. Histological analysis showed that bone remodelling was impaired. Shear stresses and shear moduli were estimated for the bone-implant interface and in the surrounding bone tissue. These estimated stresses and moduli were not found to be correlated to the dose of radiation. 相似文献
496.
Phenobarbital is known to reduce serum bilirubin concentration in the newborn infant, but optimal dosage is unknown. Ten pregnant women and their infants were given a standard regimen including prenatal maternal administration and postnatal administration to the infant during the first week of life. The plasma levels of phenobarbital in the infants were found to increase during the period of administration, and to remain high for many days beyond the period of hyperbilirubinemia. Optimal dose schedules for phenobarbital should be based both upon pharmacologic effects (including those other than bilirubin disposition) and upon the pharmacokinetic profile of the drug in the newborn infant. 相似文献
497.
LO Nilsson A Boman L S?vendahl G Grigelioniene C Ohlsson EM Ritzén J Wroblewski 《Canadian Metallurgical Quarterly》1999,84(1):370-373
Estrogens affect longitudinal bone growth through their action on endochondral bone formation. Two estrogen receptors are known, the classical estrogen receptor-alpha (ER alpha), newly demonstrated in human growth plate cartilage, and a recently cloned estrogen receptor-beta (ER beta). The present study aimed to localize a possible expression of ER beta protein in human growth plates. Tissue samples were obtained from tibial and femoral growth plates in four female pubertal patients undergoing epiphyseal surgery. Immunohistochemistry, using two different ER beta-specific antibodies, demonstrated positive staining for ER beta in hypertrophic epiphyseal chondrocytes from all patients. No staining was noted in resting or proliferative chondrocytes. These data suggest that in addition to ER alpha, human epiphyseal chondrocytes also express ER beta. The physiological role of ER beta in the regulation of longitudinal bone growth in humans remains to be elucidated. 相似文献
498.
Maider Garnica Anna Aiello Mattia Emanuela Ligotti Giulia Accardi Hugo Arasanz Ana Bocanegra Ester Blanco Anna Calabr Luisa Chocarro Miriam Echaide Grazyna Kochan Leticia Fernandez-Rubio Pablo Ramos Fanny Pojero Nahid Zareian Sergio Pieiro-Hermida Farzin Farzaneh Giuseppina Candore Calogero Caruso David Escors 《International journal of molecular sciences》2022,23(17)
The number of people that are 65 years old or older has been increasing due to the improvement in medicine and public health. However, this trend is not accompanied by an increase in quality of life, and this population is vulnerable to most illnesses, especially to infectious diseases. Vaccination is the best strategy to prevent this fact, but older people present a less efficient response, as their immune system is weaker due mainly to a phenomenon known as immunosenescence. The adaptive immune system is constituted by two types of lymphocytes, T and B cells, and the function and fitness of these cell populations are affected during ageing. Here, we review the impact of ageing on T and B cells and discuss the approaches that have been described or proposed to modulate and reverse the decline of the ageing adaptive immune system. 相似文献
499.