297 research outputs found
La radiación-γ mantiene la calidad de la mantequilla de vaca
This investigation aims to study the use of gamma irradiation for keeping the quality of cows’ butter. Fresh butter samples were exposed to gamma irradiation at doses of 0, 2.5 and 5 kGy followed by refrigerated storage and the effects of these treatments on the microbiological aspects and lipid characteristics of butter samples were studied. Moreover, fatty acid profiles and unsaponifiable matter constituents were determined by gas chromatographic analysis, while the stability of butter was determined by rancimat. The results indicated that gamma irradiation at 2.5 kGy dose reduced the counts of total bacteria, lipolytic bacteria, coliforms, molds and yeasts, however, these counts gradually increased during cold storage. Also irradiation at 5 kGy dose greatly reduced the total bacterial count which gradually increased upon storage, while completely eliminated the other determined microorganisms. Irradiation treatments increased the acid value and peroxide value of butter, while the iodine number was not altered. Moreover, gas chromatographic analysis showed that gamma irradiation slightly increased the total volatile fatty acids, total saturated fatty acids and total hydrocarbons, while slightly decreased the total unsaturated fatty acids and total sterols. In addition, irradiation of butter decreased its stability as determined by rancimat and upon storage of both irradiated and non irradiated butter samples, the acid value gradually increased, while a flexuous changes in the peroxide value were observed. The present study proved that 2.5 and 5 kGy gamma irradiation doses could keep the quality of cows’ butter and increased its shelf life at 4±1ºC for 8 and 12 weeks as compared to 4 weeks for non irradiated butter (based on the visual appearance of mold growth on the surface of samples) without any effects on its sensory properties.En esta investigación se estudió el uso de la radiación gamma para mantener la calidad de la mantequilla de vaca. Muestras de mantequilla fresca fueron expuestas a diferentes dosis de radiación gamma (0, 2.5 y 5 kGy) y guardadas en frío. Se determinaron parámetros microbiológicos y lipídicos, incluyendo el análisis de ácidos grasos y constituyentes del insaponificable mediante cromatografía gaseosa, y la estabilidad de la mantequilla por rancimat. Los resultados indicaron que la radiación gamma a la dosis de 2.5 kGy reducía el número total de bacterias, bacterias lipolíticas, coliformes, hongos y levaduras, aunque la recuperación era gradual con el tiempo de almacenamiento. A la dosis de 5 kGy, el efecto sobre el número total de bacterias fue más acentuado, hubo una recuperación gradual, pero el resto de microorganismos estudiados desaparecieron completamente. Los tratamientos de irradiación aumentaron la acidez y los peróxidos en la mantequilla, sin alterar el índice de yodo. La radiación gamma aumentó ligeramente el total de ácidos grasos volátiles, de ácidos grasos saturados y de hidrocarburos; mientras que redujo ligeramente el total de ácidos grasos insaturados y el de esteroles. La irradiación de la mantequilla afectó negativamente su estabilidad, aumentando gradualmente la acidez tanto en las muestras irradiadas como en las no irradiadas. Con el presente estudio se demuestra que la irradiación gamma a las dosis de 2.5 y 5 kGy podría mantener la calidad de la mantequilla de vaca e incrementar su vida útil si se mantiene a 4±1ºC durante 8 y 12 semanas cuando se compara con la mantequilla no irradiada y almacenada durante 4 semanas (basado en la apariencia visual del crecimiento de hongos en la superficie de las muestras), sin efectos sobre las propiedades sensoriales
A new approach for solving systems of fractional differential equations via natural transform
In this paper, A new method proposed and coined by the authors as the natural variational iteration transform method(NVITM) is utilized to solve linear and nonlinear systems of fractional differential equations. The new method is a combination of natural transform method and variational iteration method. The solutions of our modeled systems are calculated in the form of convergent power series with easily computable components. The numerical results shows that the approach is easy to implement and accurate when applied to various linear and nonlinear systems of fractional differential equations
Review: The Stochastic Approach and Systems of Index Numbers
The main objective of the paper is to review a number of widely used multilateral index numbers for International comparisons of purchasing power parities (PPPs) and real incomes that can be derived using the stochastic approach. The paper discuss that price index numbers from commonly used methods like the Ikleacute, the Rao-weighted, and an additive multilateral system are all estimators of the parameters of the countryndashproductndashdummy (CPD) model. The paper also presents the method of moments (MOM) as an approach to estimate PPPs under the stochastic approach and shows how the GearyndashKhamis system of multilateral index numbers is a method of moments estimator of the parameters of the CPD model.nbs
High frequency of SEN virus infection in thalassemic patients and healthy blood donors in Iran
<p>Abstract</p> <p>Background</p> <p>SEN virus is a blood-borne, circular ssDNA virus and possessing nine genotypes (A to I). Among nine genotypes, SENV-D and SENV-H genotypes have the strong link with patients with unknown (none-A to E) hepatitis infections. Infection with blood-borne viruses is the second important cause of death in thalassemic patients. The aim of this study was to determine the frequency of SENV-D and SENV-H genotypes viremia by performing nested-PCR in 120 and 100 sera from healthy blood donors and thalassemic patients in Guilan Province, North of Iran respectively. Also, to explicate a possible role of SEN virus in liver disease and established changes in blood factors, the serum aminotransferases (ALT and AST) and some of the blood factors were measured.</p> <p>Results</p> <p>Frequency of SENV-D, SENV (SENV-H or SENV-D) and co-infection (both SENV-D and SENV-H) viremia was significantly higher among thalassemic patients than healthy individuals. Frequency of SENV-H viremia was significantly higher than SENV-D among healthy individuals. In comparison to SENV-D negative patients, the mean of mean corpuscular hemoglobin was significantly higher in SENV-D positive and co-infection cases (<it>P </it>< 0.05). The means of AST and ALT were significantly higher in thalassemic patients than healthy blood donors, but there were not any significant differences in the means of the liver levels between SENV-positive and -negative individuals in healthy blood donors and thalassemic patients. High nucleotide homology observed among PCR amplicon's sequences in healthy blood donors and thalassemic patients.</p> <p>Conclusions</p> <p>The high rate of co-infection shows that different genotypes of SENV have no negative effects on each other. The high frequency of SENV infection among thalassemic patients suggests blood transfusion as main route of transmission. High frequency of SENV infection in healthy individuals indicates that other routes rather than blood transfusion also are important. Frequency of 90.8% of SENV infection among healthy blood donors as well as high nucleotide homology of sequenced amplicons between two groups can probably suggest that healthy blood donors infected by SENV act partly as a source of SENV transmission to the thalassemic patients. In conclusion, SENV-D isolate in Guilan Province may be having a pathogenic agent for thalassemic patients.</p
Response Surface Methodology (RSM) implementation in zro particles reinforced aluminium chips by Hot Equal Channel Pressing (ECAP)
In recent years, the interest on solid-state recycling of aluminum chips increases over
the years due to the less energy consumption of the process. This research studies the
quantitative effects of preheating temperature and volume fraction of Zirconium
Dioxide when it is reinforced to the Aluminum alloy AA6061 on its mechanical
properties. The parameters of the experiment are preheating temperature and volume
fraction of ZrO . Temperature are varied between 450 and 550 ℃ according to the
boundary parameters. The volume fraction of ZrO consists of 5, 10 and 15% of the
reinforcement. Increasing the volume fraction of ZrO correlates with the increase of
mechanical and physical properties. Design of Experimental with factorial design was
implemented to analyse the magnitude of response on the mechanical properties from
the variable of parameters. The preheating temperature was revealed to be the most
significant factor affecting the yield strength and the microhardness of the composite
followed by the volume fraction of ZrO . It is revealed that the most optimum
temperature is 550 ℃ and the optimum percentage of volume fraction is 9.28%. Both highest microhardness and yield strength were obtained from these optimum
temperatures. Scanning Electron Microscope (SEM) revealed on how elongation in
Zirconia chips is affected by the amount of ZrO reinforcement. Energy Dispersive
Spectroscopy (EDS) analysis performed revealed on the arbitrary weight out of total
weight for every element in the composite such as Al, Zr, O and Si
PARP inhibition by olaparib or gene knockout blocks asthma-like manifestation in mice by modulating CD4+ T cell function
Background: An important portion of asthmatics do not respond to current therapies. Thus, the need for new therapeutic drugs is urgent. We have demonstrated a critical role for PARP in experimental asthma. Olaparib, a PARP inhibitor, was recently introduced in clinical trials against cancer. The objective of the present study was to examine the efficacy of olaparib in blocking established allergic airway inflammation and hyperresponsiveness similar to those observed in human asthma in animal models of the disease. Methods: We used ovalbumin (OVA)-based mouse models of asthma and primary CD4+ T cells. C57BL/6J WT or PARP-1-/- mice were subjected to OVA sensitization followed by a single or multiple challenges to aerosolized OVA or left unchallenged. WT mice were administered, i.p., 1 mg/kg, 5 or 10 mg/kg of olaparib or saline 30 min after each OVA challenge. Results: Administration of olaparib in mice 30 min post-challenge promoted a robust reduction in airway eosinophilia, mucus production and hyperresponsiveness even after repeated challenges with ovalbumin. The protective effects of olaparib were linked to a suppression of Th2 cytokines eotaxin, IL-4, IL-5, IL-6, IL-13, and M-CSF, and ovalbumin-specific IgE with an increase in the Th1 cytokine IFN-\u3b3. These traits were associated with a decrease in splenic CD4+ T cells and concomitant increase in T-regulatory cells. The aforementioned traits conferred by olaparib administration were consistent with those observed in OVA-challenged PARP-1-/- mice. Adoptive transfer of Th2-skewed OT-II-WT CD4+ T cells reversed the Th2 cytokines IL-4, IL-5, and IL-10, the chemokine GM-CSF, the Th1 cytokines IL-2 and IFN-\u3b3, and ovalbumin-specific IgE production in ovalbumin-challenged PARP-1-/-mice suggesting a role for PARP-1 in CD4+ T but not B cells. In ex vivo studies, PARP inhibition by olaparib or PARP-1 gene knockout markedly reduced CD3/CD28-stimulated gata-3 and il4 expression in Th2-skewed CD4+ T cells while causing a moderate elevation in t-bet and ifn-\u3b3 expression in Th1-skewed CD4+ T cells. Conclusions: Our findings show the potential of PARP inhibition as a viable therapeutic strategy and olaparib as a likely candidate to be tested in human asthma clinical trials
Novel TMC8 splice site mutation in epidermodysplasia verruciformis and review of HPV infections in patients with the disease
Epidermodysplasia verruciformis (EV) is a genodermatosis leading to infections with cutaneous HPV, persistent plane warts and a high rate of non-melanoma skin cancer (NMSC). Biallelic loss-of-function mutations in TMC6 and TMC8 are known to be causative.; The aim of this study was to report EV-causing mutations in four patients with EV and to give an overview of all described patients with EV.; We investigated four patients with classical features of EV from two families. All patients were affected by plane warts with typical EV histology since early childhood, and β-HPVs were detected on their skin. One patient had recurring cutaneous squamous cell carcinomas (cSCC) and carcinomas in situ (Bowen type). We sequenced both TMC6/8 for disease-causing mutations and quantified levels of gene expression. We also performed a systematic literature review to discuss these patients in the context of previously reported cases, mutations already identified, as well as HPV types.; Three patients of one family carried a homozygous splice site mutation in TMC8 resulting in aberrantly spliced transcripts that were not degraded. By contrast, no TMC6/8 mutation was detected in the patient from the other family. A systematic literature review revealed 501 described patients with EV. Around 40% of patients with EV analysed for genetic alterations carried no mutation in TMC6/8. While β-HPVs were identified in the majority of cases, α-HPVs were detected in several individuals.; The relatively high proportion of EV patients without mutation in TMC6/8 indicates the existence of EV-causing mutations in additional, presently unknown gene(s). However, a homozygous TMC8 splice site mutation in our patients resulted in aberrant transcripts which cannot retain the healthy phenotype. The literature review revealed that HPV-5 is the most commonly identified HPV in patients with EV, but HPV-3, HPV-14 and HPV-20 were unexpectedly identified more frequently than HPV-8
Recurrent respiratory papillomatosis: an overview of current thinking and treatment
Human papillomaviruses (HPV) infection in benign laryngeal papillomas is well established. The vast majority of recurrent respiratory papillomatosis lesions are due to HPV types 6 and 11. Human papillomaviruses are small non-enveloped viruses (>8 kb), that replicate within the nuclei of infected host cells. Infected host basal cell keratinocytes and papillomas arise from the disordered proliferation of these differentiating keratinocytes. Surgical debulking of papillomas is currently the treatment of choice; newer surgical approaches utilizing microdebriders are replacing laser ablation. Surgery aims to secure an adequate airway and improve and maintain an acceptable quality of voice. Adjuvant treatments currently used include cidofovir, indole-3-carbinol, ribavirin, mumps vaccine, and photodynamic therapy. The recent licensing of prophylactic HPV vaccines is a most interesting development. The low incidence of RRP does pose significant problems in recruitment of sufficient numbers to show statistical significance. Large multi-centre collaborative clinical trials are therefore required. Even so, sufficient clinical follow-up data would take several years
Frequency of MTHFR G1793A polymorphism in individuals with early coronary artery disease: cross-sectional study
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