171 research outputs found

    Generation of fully non-stationary random processes consistent with target seismic accelerograms

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    Abstract In this paper, a method for generating samples of a fully non-stationary zero-mean Gaussian process, having a target acceleration time-history as one of its own samples, is presented. The proposed method requires the following steps: i) divide the time axis of the target accelerogram in contiguous time intervals in which a uniformly modulated process is introduced as the product of a deterministic modulating function per a stationary zero-mean Gaussian sub-process, whose power spectral density (PSD) function is filtered by two Butterworth filters; ii) estimate, in the various time intervals, the parameters of modulating functions by least-square fitting the expected energy of the proposed model to the energy of the target accelerogram; iii) estimate the parameters of the PSD function of the stationary sub-process, once the occurrences of maxima and of zero-level up-crossings of the target accelerogram, in the various intervals, are counted; iv) obtain the evolutionary spectral representation of the fully non-stationary process by adding the various contribution evaluated in the various intervals

    Microencapsulation effectiveness of small active molecules in biopolymer by ultrasonic atomization technique

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    A method to produce biopolymeric (alginate) microparticles by ultrasonic assisted atomization, previously developed, has been applied to the production of microparticles loaded with a small active molecule (theophylline). Fine loaded alginate droplets have been cross-linked with divalent ions to produce microparticles. Once produced, the particles have been separated by centrifugation or filtration and then they have been dried. Drug release has been evaluated by dissolution tests, dissolving the dried particles in acidic solution at pH 1 for a given time and then at pH 7 to simulate the stomach and intestinal environment, respectively. The encapsulation efficiency and the drug loading have been investigated and the operating conditions have been changed to clarify the role of the transport phenomena on the overall process. To increase the drug loading, shorter separation time and better network’s structure were identified as the key operating parameters to allow the process to gain interest from a practical point of view

    Intensification of biopolymeric microparticles production by ultrasonic assisted atomization

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    In this work ultrasonic atomization process is applied to produce biopolymer microparticles with potential applications in pharmaceutical and nutraceutical fields. Natural polymer (alginate)/water solution is atomized by ultrasonic assisted process and the droplets spray is reticulated using a solution of copper sulfate, where the Cu2+ ions cause the formation of a network structure (hard porous gel). Several operating parameters (solution concentration, flow rate, atomization power) are changed to study their effects on the produced microparticles. Literature correlations able to predict the features of the droplets as functions of process parameters are optimized using a statistical approach. Furthermore, the energy requirement for the drops production is compared with the energy required by traditional techniques to evaluate the intensification effect of the ultrasonic on the atomization process. doi:10.1016/j.cep.2009.08.00

    Quantification of Some Heavy Metals in Hair of Dairy Cows Housed in Different Areas from Sicily as a Bioindicator of Environmental Exposure—A Preliminary Study

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    Simple Summary: Heavy metals are considered one of the most critical pollutants that contaminate the environment through anthropogenic or natural activities. Animals are very good indicators of environmental pollution as they inhabit the same space as humans and are exposed to the same pollutants. The levels of selected heavy metals in hair samples of Holstein dairy cows are evaluated in this study. The gathered results would emphasize the usefulness of hair samples as possible bioindicators of heavy metal exposure that, in the long term, could be harmful to the final consumer. Moreover, this study gives an overview about the scenario of anthropogenic activity effects on heavy metal accumulation in dairy cows from Ragusa, a peculiar Sicilian province particularly dedicated to cow breeding for milk production. Abstract: The objective of this preliminary study was to evaluate the levels of selected heavy metals in hair samples of Holstein dairy cows reared on agricultural soils characterized by grassland subjected to anthropogenic impacts. Ninety Holstein-Friesian cows were enrolled in the study and divided into six groups according to farm origin. From each animal, hair samples were collected in order to determine the content of aluminum, chromium, iron, copper, zinc, arsenic, cadmium, and lead. One-way analysis of variance was applied to assess statistically significant differences in the studied heavy metals among the six groups. A significant effect of groups (p < 0.05) on all tested heavy metals was observed. In this study, the low concentration of heavy metals in the hair of the studied animals led us to think that the cows were subjected to low levels of these compounds, preventing them from bioaccumulating. Although the current study provides only preliminary results, it highlights the importance of investigating the concentration of heavy metals in cow hair to improve the health and welfare of both humans and animals

    Unilateral condylar hyperplasia recurrence after orthognathic surgery: a case report

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    Introduction: Unilateral Condylar Hyperplasia (UCH) is an uncommon condition resulting in facial asymmetry and malocclusion. At the time of diagnosis, an accurate evaluation of condylar activity through bone SPECT is necessary to determine the most appropriate surgical treatment. The Authors present a case of a UCH recurrence after orthognathic surgery in order to discuss about the clinical role of condylar SPECT in UCH therapeutic management. Case report: A 60-years old female patient was referred to the Department of Maxillo-Facial Surgery of Sapienza University of Rome for a relapse of mandibular laterodeviation. At the age of 24, she underwent orthognathic surgery after a diagnosis of UCH without condylar SPECT evaluation. As part of our clinical routine, condylar SPECT was performed and a significant difference in radiotracer uptake (20%) was found between the left condylar region and the contralateral one. She underwent high condilectomy and Bilateral Mandibular Sagittal Osteotomy. She had no evidence of recurrence till today. Discussion: Optimal surgical management of UCH is still controversial. In the diagnostic phase of UCH, a functional evaluation of condylar growth status by bone SPECT is an essential step to avoid long-term recurrence of mandibular asymmetry. On the basis of condylar metabolic activity, UCH can be classified in an active phase or a stationary phase. Clinical and functional evaluation of patients with mandibular asymmetry should be standardized in order to plan the most appropriate surgical and orthodontic treatment

    Designing in-vitro systems to simulate the in-vivo permeability of drugs

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    In this work an engineering approach, consisting in an experimental procedure and a model to derive the data, was presented and applied to improve the testing methods of pharmaceuticals. The permeability of several active molecules have been evaluated across a synthetic membrane. The permeability of these drugs measured through the artificial membrane were successfully correlated to their in-vivo permeability. The relationship with in-vivo permeability was derived, and then a rule to design systems to simulate the intestinal absorption was proposed to reduce the need for expensive and ethical problematic in-vivo measurement

    An engineering approach to biomedical sciences: advanced testing methods and pharmacokinetic modeling

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    In this paper, the philosophy of a research in pharmacology field, driven by an engineering approach, was described along with some case histories and examples. The improvement in the testing methods for pharmaceutical systems (in-vitro techniques), as well as the proposal and the testing of mathematical models to describe the pharmacokinetics (in-silico techniques) are reported with the aim of pointing out methodologies and tools able to reduce the need of expensive and ethical problematic in-vivo measurements

    Management Factors Influence AnimalWelfare and the Correlation to Infectious Diseases in Dairy Cows

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    Simple Summary: To investigate the relationship between some infectious diseases (Mycobacterium avium subsp. paratuberculosis, Chlamydiophila abortus, Neospora caninum, bovine viral diarrhea virus, and the bovine herpesvirus) and the dairy farms’ welfare scores, 36 dairy farms were monitored using the Italian National AnimalWelfare Reference Center (CreNBA) checklist. Farms and their animals were scored in five different areas, namely: Area A, “Farm management and personnel”; Area B, “Facilities and equipment”; Area C, “Animal-based measures”; Area D, “Inspection of microclimatic environmental conditions and alarm systems”; and Area E, “Biosecurity”. The recorded scores were compared between two farming conditions (access to pasture and indoor housing) and correlated with the serum data. Our results indicated that an accurate application of the checklist could be an instrument to prevent and control the spread of infections in dairy farms. Abstract: The present study assessed dairy cow welfare through the application of the Italian National Animal Welfare Reference Center (CReNBA) checklist in 36 dairy farms located in Ragusa (Italy) subjected to two different management conditions, housing with free access to pasture (Group 1, farms n = 17) and indoor housing (Group 2, farms n = 19). Five areas of investigation were considered: Area A, “Farm management and personnel”; Area B, “Facilities and equipment”; Area C, “Animal-based measures”; Area D, “Inspection of microclimatic environmental conditions and alarm systems”; and Area E, “Biosecurity”. Blood samples were collected by coccygeal venipuncture from all animals (4081 cows). The specific antibodies against Mycobacterium avium subsp. paratuberculosis, Chlamydiophila abortus, Neospora caninum, bovine viral diarrhea virus, and the bovine herpesvirus were assessed by enzyme linked immunosorbent assay (ELISA) serological test. Group 1 (access to pasture) showed a lower value of percentage score recorded in Area A (p = 0.02) and E (p = 0.01) than Group 2 (indoor housing). Herpesvirus (Infectious bovine rhinotracheitis - IBR - detection of gB antibodies/IBR-gB) blood concentrations were higher in the cows housed indoor versus those with access to pasture (p = 0.01). Farm management and personnel (score A) was correlated with the level of bovine viral diarrhea virus ( = 0.3754) and bovine-herpesvirus-specific antibodies (IBR-gB) ( = 0.4159). “Biosecurity” percentage score showed a significant correlation with Chlamydiophila abortus ( = 0.4621) in the cows with access to pasture and IBR-gB ( = 0.3435) in the cows housed fully indoors. Group 2 showed a significantly reduced level of antibodies against Neospora caninum. In conclusion, differences in the welfare assessment score were observed in the “Farm management and personnel” and “Biosecurity” between the two management conditions. It had an effect on the prevalence of herpesvirus, which occurred more in cattle with access to pasture. Therefore, an accurate application of the checklist could be an instrument to prevent and control the spread of infections in farms
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