1,273 research outputs found
Magnetic and elastic properties of CoFe2O4- polydimethylsiloxane magnetically oriented elastomer nanocomposites
Magnetic elastic structured composites were prepared by using CoFe 2O4 ferromagnetic and superparamagnetic nanoparticles as fillers in polydimethylsiloxane (PDMS) matrixes, which were cured in the presence of a uniform magnetic field. Cobalt-iron oxide nanoparticles of three different average sizes (between 2 and 12 nm) were synthesized and characterized. The smallest nanoparticles presented superparamagnetic behavior, with a blocking temperature of approximately 75 K, while larger particles are already blocked at room temperature. Macroscopically structured-anisotropic PDMS-CoFe2O4 composites were obtained when curing the dispersion of the nanoparticles in the presence of a uniform magnetic field (0.3 T). The formation of the particle's chains (needles) orientated in the direction of the magnetic field was observed only when loading with the larger magnetically blocked nanoparticles. The SEM images show that the needles are formed by groups of nanoparticles which retain their original average size. The Young's moduli of the structured composites are four times larger when measured along the oriented needles than in the perpendicular direction. Magnetization (VSM) and ferromagnetic resonance curves of the structured composites were determined as a function of the relative orientation between the needles and the probe field. The remanence magnetization was 30 higher when measured parallel to the needles, while the coercive field remains isotropic. These observations are discussed in terms of the individual nanoparticle's properties and its aggregation in the composites. © 2011 American Institute of Physics.Fil:Soledad Antonel, P. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Jorge, G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Perez, O.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:MartĂn Negri, R. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina
Enhancement of Water Transport and Microstructural Changes Induced by High-Intesity Ultrasound Application on Orange Peel Drying
The main aim of this work was to evaluate the effect of high-intensity ultrasound (US) on the drying kinetics of orange peel as well as its influence on the microstructural changes induced during drying. Convective drying kinetics of orange peel slabs were carried out at a relative humidity of 26.5±0.9%, 40 °C and 1 m/s with (AIR+US) and without (AIR) ultrasound application. In order to identify the US effect on water transport, drying kinetics were analyzed by taking the diffusion theory into account. Fresh, AIR and AIR+US dried samples were
analyzed using Cryo-Scanning Electron Microscopy. Results showed that the drying kinetics of orange peel were significantly improved by US application, which involved a significant (p<0.05) improvement of mass transfer coefficient and effective moisture diffusivity. The
effects on mass transfer properties were confirmed with microstructural observations. In the cuticle surface of flavedo, the pores were obstructed by the spread of the waxy components, this fact evidencing US effects on the air solid interfaces. Furthermore, the cells of the albedo were disrupted by US, as it created large intercellular air spaces facilitating water transfer through the tissue.The authors would like to acknowledge the financial support of MICINN and CEE (European Regional Development Fund) from projects Ref. DPI2009-14549-C04-04, PSE-060000-2009-003, and FP6-2004-FOOD-23140 HIGHQ RTE.GarcĂa PĂ©rez, JV.; Ortuño Cases, C.; Puig GĂłmez, CA.; CĂĄrcel CarriĂłn, JA.; PĂ©rez Munuera, IM. (2012). Enhancement of Water Transport and Microstructural Changes Induced by High-Intesity Ultrasound Application on Orange Peel Drying. 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Some applications of air-borne power ultrasound to food processing. In M. J. W., Povey, T. J. Mason (Eds.), Ultrasound in Food Processing. UK: London, Chapman & Hall.Gallego-JuĂĄrez, J. A., RodrĂguez-Corral, G., GĂĄlvez-Moraleda, J. C., & Yang, T. S. (1999). A new high intensity ultrasonic technology for food dehydration. Drying Technology, 17(3), 597â608.Garau, M. C., Simal, S., Femenia, A., & RossellĂł, C. (2006). Drying of orange skin: drying kinetics modelling and functional properties. Journal of Food Engineering, 75(2), 288â295.Garau, M. C., Simal, S., Rossello, C., & Femenia, A. (2007). Effect of air-drying temperature on physico-chemical properties of dietary fibre and antioxidant capacity of orange (Citrus aurantium v. Canoneta) by-products. Food Chemistry, 104(3), 1014â1024.Garcia-Perez, J. V., CĂĄrcel, J. A., De la Fuente, S., & Riera, E. (2006). Ultrasonic drying of foodstuff in a fluidized bed. Parametric study. Ultrasonics, 44, 539â543.Garcia-Perez, J. V., CĂĄrcel, J. A., Benedito, J., & Mulet, A. (2007). Power ultrasound mass transfer enhancement in food drying. Food and Bioproducts Proccessing, 85(3), 247â254.GuinĂ©, R. P. F., Henrriques, F., Barroca, M. J. (2010). Mass transfer coefficients for the drying of pumpkin (Cucurbita moschata) and dried product quality. Food and Bioprocess Technology. doi: 10.1007/s11947-009-0275 , in press.Khalloufi, S., Almeida-Rivera, C., & Bongers, P. (2009). A theoretical model and its experimental validation to predict the porosity as a function of shrinkage and collapse phenomena during drying. Food Research International, 42(8), 1122â1130.Larrauri, J. A., RupĂ©rez, P., Bravo, L., & Saura-Calixto, F. (1996). High dietary fibre powders from orange and lime peels: associated polyphenols and antioxidant capacity. Food Research International, 29(8), 757â762.Mujumdar, A. S., & Law, C. L. (2010). Drying technology: trends and applications in postharvest processing. 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Mass transfer modelling during osmotic dehydration of hexahedral pineapple slices in limited volume solutions. Food and Bioprocess Technology, 3(3), 427â433.Salvador, A., Salvador, L., Besada, C., Larrea, V., Hernando, I., & Perez-Munuera, I. (2008). Reduced effectiveness of the treatment for removing astringency in persimmon fruit when stored at 15 °C: Physiological and microstructural study. Postharvest Biology and Technology, 49(3), 340â347.Sanchez, E. S., Simal, S., FemenĂa, A., Benedito, J., & RosellĂł, C. (2001). Effect of acoustic brining on lipolysis and on sensory characteristics of Mahon cheese. Journal of Food Science, 66(6), 892â896.Sanchez, E. S., Simal, S., FemenĂa, A., Llul, P., & RosellĂł, C. (2001). Proteolysis of Mahon cheese as affected by acoustic-assited brining. European Food Research and Technology, 212(2), 147â152.Sharma, A., & Gupta, M. N. (2006). Ultrasonic pre-irradiation effect upon aqueous enzymatic oil extraction from almond and apricot seeds. 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Targeted glutamate supply boosts insulin concentrations, ovarian activity, and ovulation rate in yearling goats during the anestrous season
The neuroendocrine regulation of the seasonal reproductive axis requires the integration of internal and external signals to ensure synchronized physiological and behavioral responses. Seasonal reproductive changes contribute to intermittent production, which poses challenges for optimizing goat product yields. Consequently, a significant objective in seasonal reproduction research is to attain continuous reproduction and enhance profitability in goat farming. Glutamate plays a crucial role as a modulator in several reproductive and metabolic processes. Hence, the aim of this study was to evaluate the potential impact of exogenous glutamate administration on serum insulin concentration and ovarian function during the out-of-season period in yearling goats. During the anestrous season, animals were randomly located in individual pens to form two experimental groups: (1) glutamate (n = 10, live weight (LW) = 29.1 ± 1.02 kg, body condition score (BCS) = 3.4 ± 0.2 units) and (2) control (n = 10; LW = 29.2 ± 1.07 kg, BCS = 3.5 ± 0.2), with no differences (p < 0.05) regarding LW and BCS. Then, goats were estrus-synchronized, and blood sampling was carried out for insulin quantification. Ovaries were ultrasonographically scanned to assess ovulation rate (OR), number of antral follicles (AFs), and total ovarian activity (TOA = OR + AF). The research outcomes support our working hypothesis. Certainly, our study confirms that those yearling goats treated with exogenous glutamate displayed the largest (p < 0.05) insulin concentrations across time as well as an augmented (p < 0.05) out-of-season ovarian activity
Ultrasonically enhanced desalting of cod (Gadus morhua). Mass transport kinetics and structural changes
The search for an alternative means of reconstituting dried and salted products prior to consumption is of
relevance for the food industry. New techniques should speed up the process while causing minimum
impact on product quality. Thereby, the aim of this work was to evaluate both the effect of high-intensity
ultrasound application on the desalting kinetics of cod, as well as the changes in its textural and
microstructural properties. Moisture and NaCl transport was studied separately by taking the diffusion
theory into account. The evolution in the swelling and hardness of cod during desalting was determined
and modeled by assuming first-order kinetics. A microstructural analysis of raw salted and desalted cod
was also carried out by means of light microscopy and SEM techniques. Ultrasound application significantly
(p < 0.05) affected both moisture and NaCl transport and the increase in both effective diffusivities
(from 24% to 103%) was linked to the acoustic pressure applied. The desalting process induced the
swelling and the softening of the cod tissue, both of which are phenomena that are intensified by ultrasound
application. From the microstructural observations, it was shown that the application of highintensity
ultrasound modified the cod structure, e.g. the increase in the fiber width.The authors acknowledge the economic support of the project ref. DPI2013-37466-C03-03 co-funded by the Spanish Ministerio de Economia y Competitividad and the European Regional Development Found (ERDF). Cesar Ozuna thanks Universitat Politecnica de Valencia for an FPI grant (Ref. 2009-02). The author also wishes to thank Carmen Cambra S.L. for selecting the raw material.Ozuna LĂłpez, C.; Puig GĂłmez, CA.; GarcĂa PĂ©rez, JV.; Carcel CarriĂłn, JA. (2014). Ultrasonically enhanced desalting of cod (Gadus morhua). Mass transport kinetics and structural changes. Food Science and Technology. 59(1):130-137. doi:10.1016/j.lwt.2014.05.062S13013759
A Novel Small Molecule Inhibitor of Influenza A Viruses that Targets Polymerase Function and Indirectly Induces Interferon
Influenza viruses continue to pose a major public health threat worldwide and options for antiviral therapy are limited by the emergence of drug-resistant virus strains. The antiviral cytokine, interferon (IFN) is an essential mediator of the innate immune response and influenza viruses, like many viruses, have evolved strategies to evade this response, resulting in increased replication and enhanced pathogenicity. A cell-based assay that monitors IFN production was developed and applied in a high-throughput compound screen to identify molecules that restore the IFN response to influenza virus infected cells. We report the identification of compound ASN2, which induces IFN only in the presence of influenza virus infection. ASN2 preferentially inhibits the growth of influenza A viruses, including the 1918 H1N1, 1968 H3N2 and 2009 H1N1 pandemic strains and avian H5N1 virus. In vivo, ASN2 partially protects mice challenged with a lethal dose of influenza A virus. Surprisingly, we found that the antiviral activity of ASN2 is not dependent on IFN production and signaling. Rather, its IFN-inducing property appears to be an indirect effect resulting from ASN2-mediated inhibition of viral polymerase function, and subsequent loss of the expression of the viral IFN antagonist, NS1. Moreover, we identified a single amino acid mutation at position 499 of the influenza virus PB1 protein that confers resistance to ASN2, suggesting that PB1 is the direct target. This two-pronged antiviral mechanism, consisting of direct inhibition of virus replication and simultaneous activation of the host innate immune response, is a unique property not previously described for any single antiviral molecule
Inside the Outbreak of the 2009 Influenza A (H1N1)v Virus in Mexico
Influenza viruses pose a threat to human health because of their potential to cause global disease. Between mid March and mid April a pandemic influenza A virus emerged in Mexico. This report details 202 cases of infection of humans with the 2009 influenza A virus (H1N1)v which occurred in Mexico City as well as the spread of the virus throughout the entire country.From May 1st to May 5th nasopharyngeal swabs, derived from 751 patients, were collected at 220 outpatient clinics and 28 hospitals distributed throughout Mexico City. Analysis of samples using real time RT-PCR revealed that 202 patients out of the 751 subjects (26.9%) were confirmed to be infected with the new virus. All confirmed cases of human infection with the strain influenza (H1N1)v suffered respiratory symptoms. The greatest number of confirmed cases during the outbreak of the 2009 influenza A (H1N1)v were seen in neighbourhoods on the northeast side of Mexico City including Iztapalapa, Gustavo A. Madero, Iztacalco, and Tlahuac which are the most populated areas in Mexico City. Using these data, together with data reported by the Mexican Secretariat of Health (MSH) to date, we plot the course of influenza (H1N1)v activity throughout Mexico.Our data, which is backed up by MSH data, show that the greatest numbers of the 2009 influenza A (H1N1) cases were seen in the most populated areas. We speculate on conditions in Mexico which may have sparked this flu pandemic, the first in 41 years. We accept the hypothesis that high population density and a mass gathering which took in Iztapalapa contributed to the rapid spread of the disease which developed in three peaks of activity throughout the Country
30-Day morbidity and mortality of bariatric metabolic surgery in adolescence during the COVID-19 pandemic â The GENEVA study
Background: Metabolic and bariatric surgery (MBS) is an effective treatment for adolescents with severe obesity. Objectives: This study examined the safety of MBS in adolescents during the coronavirus disease 2019 (COVID-19) pandemic. Methods: This was a global, multicentre and observational cohort study of MBS performed between May 01, 2020, and October 10,2020, in 68 centres from 24 countries. Data collection included in-hospital and 30-day COVID-19 and surgery-specific morbidity/mortality. Results: One hundred and seventy adolescent patients (mean age: 17.75 ± 1.30 years), mostly females (n = 122, 71.8%), underwent MBS during the study period. The mean pre-operative weight and body mass index were 122.16 ± 15.92 kg and 43.7 ± 7.11 kg/m2, respectively. Although majority of patients had pre-operative testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (n = 146; 85.9%), only 42.4% (n = 72) of the patients were asked to self-isolate pre-operatively. Two patients developed symptomatic SARS-CoV-2 infection post-operatively (1.2%). The overall complication rate was 5.3% (n = 9). There was no mortality in this cohort. Conclusions: MBS in adolescents with obesity is safe during the COVID-19 pandemic when performed within the context of local precautionary procedures (such as pre-operative testing). The 30-day morbidity rates were similar to those reported pre-pandemic. These data will help facilitate the safe re-introduction of MBS services for this group of patients
30-day morbidity and mortality of sleeve gastrectomy, Roux-en-Y gastric bypass and one anastomosis gastric bypass: a propensity score-matched analysis of the GENEVA data
Background: There is a paucity of data comparing 30-day morbidity and mortality of sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and one anastomosis gastric bypass (OAGB). This study aimed to compare the 30-day safety of SG, RYGB, and OAGB in propensity score-matched cohorts. Materials and methods: This analysis utilised data collected from the GENEVA study which was a multicentre observational cohort study of bariatric and metabolic surgery (BMS) in 185 centres across 42 countries between 01/05/2022 and 31/10/2020 during the Coronavirus Disease-2019 (COVID-19) pandemic. 30-day complications were categorised according to the ClavienâDindo classification. Patients receiving SG, RYGB, or OAGB were propensity-matched according to baseline characteristics and 30-day complications were compared between groups. Results: In total, 6770 patients (SG 3983; OAGB 702; RYGB 2085) were included in this analysis. Prior to matching, RYGB was associated with highest 30-day complication rate (SG 5.8%; OAGB 7.5%; RYGB 8.0% (p = 0.006)). On multivariate regression modelling, Insulin-dependent type 2 diabetes mellitus and hypercholesterolaemia were associated with increased 30-day complications. Being a non-smoker was associated with reduced complication rates. When compared to SG as a reference category, RYGB, but not OAGB, was associated with an increased rate of 30-day complications. A total of 702 pairs of SG and OAGB were propensity score-matched. The complication rate in the SG group was 7.3% (n = 51) as compared to 7.5% (n = 53) in the OAGB group (p = 0.68). Similarly, 2085 pairs of SG and RYGB were propensity score-matched. The complication rate in the SG group was 6.1% (n = 127) as compared to 7.9% (n = 166) in the RYGB group (p = 0.09). And, 702 pairs of OAGB and RYGB were matched. The complication rate in both groups was the same at 7.5 % (n = 53; p = 0.07). Conclusions: This global study found no significant difference in the 30-day morbidity and mortality of SG, RYGB, and OAGB in propensity score-matched cohorts
Search for a vector-like quark TâČ â tH via the diphoton decay mode of the Higgs boson in proton-proton collisions at = 13 TeV
A search for the electroweak production of a vector-like quark TâČ, decaying to a top quark and a Higgs boson is presented. The search is based on a sample of proton-proton collision events recorded at the LHC at = 13 TeV, corresponding to an integrated luminosity of 138 fbâ1. This is the first TâČ search that exploits the Higgs boson decay to a pair of photons. For narrow isospin singlet TâČ states with masses up to 1.1 TeV, the excellent diphoton invariant mass resolution of 1â2% results in an increased sensitivity compared to previous searches based on the same production mechanism. The electroweak production of a TâČ quark with mass up to 960 GeV is excluded at 95% confidence level, assuming a coupling strength ÎșT = 0.25 and a relative decay width Î/MTâČ < 5%
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