231 research outputs found
Compositional disorder and its influence on the structural, electronic and magnetic properties of MgC(Ni_{1-x}Co_{x})_{3} alloys using first-principles
First-principles, density-functional based electronic structure calculations
are carried out for MgC(Ni_{1-x}Co_{x})_{3} alloys over the concentration range
0\leq x\leq1, using Korringa-Kohn-Rostoker coherent-potential approximation
(KKR CPA) method in the atomic sphere approximation (ASA). The self-consistent
calculations are used to study the changes as a function of x in the equation
of state parameters, total and partial densities of states, magnetic moment and
the on-site exchange interaction parameter. To study the magnetic properties as
well as its volume dependence, fixed-spin moment calculations in conjunction
with the phenomenological Landau theory are employed. The salient features that
emerge from these calculations are (i) a concentration independent variation in
the lattice parameter and bulk modulus at x~0.75 with an anomaly in the
variation of the pressure derivative of bulk modulus, (ii) the fixed-spin
moment based corrections to the overestimated magnetic ground state for 0.0\leq
x\leq0.3 alloys, making the results consistent with the experiments, and (iii)
the possibility of multiple magnetic states at x~0.75, which, however, requires
further improvements in the calculations
Antiferromagnetic Order and Superconductivity in Sr4(Mg0.5-xTi0.5+x)2O6Fe2As2 with Electron Doping: 75As-NMR Study
We report an 75As-NMR study on iron (Fe)-based superconductors with thick
perovskitetype blocking layers Sr4(Mg0.5-xTi0.5+x)2O6Fe2As2 with x=0 and 0.2.
We have found that antiferromagnetic (AFM) order takes place when x=0, and
superconductivity (SC) emerges below Tc=36 K when x=0.2. These results reveal
that the Fe-pnictides with thick perovskitetype blocks also undergo an
evolution from the AFM order to the SC by doping electron carriers into FeAs
planes through the chemical substitution of Ti+4 ions for Mg+2 ions, analogous
to the F-substitution in LaFeAsO compound. The reason why the Tc=36 K when
x=0.2 being higher than the optimally electron-doped LaFeAsO with Tc=27 K
relates to the fact that the local tetrahedron structure of FeAs4 is optimized
for the onset of SC.Comment: 4 pages, 3 figures, 1 tabl
Effect of coronavirus disease 2019 (COVID‐19) on maternal, perinatal and neonatal outcome: systematic review.
Objective To evaluate the effect of coronavirus disease
2019 (COVID-19) on maternal, perinatal and neonatal
outcome by performing a systematic review of available
published literature on pregnancies affected by
COVID-19.
Methods We performed a systematic review to evaluate
the effect of COVID-19 on pregnancy, perinatal
and neonatal outcome. We conducted a comprehensive
literature search using PubMed, EMBASE, the
Cochrane Library, China National Knowledge Infrastructure
Database and Wan Fang Data up to and
including 20 April 2020 (studies were identified through
PubMed alert after that date). For the search strategy,
combinations of the following keywords and medical
subject heading (MeSH) terms were used: ‘SARS-CoV-2’,
‘COVID-19’, ‘coronavirus disease 2019’, ‘pregnancy’,
‘gestation’, ‘maternal’, ‘mother’, ‘vertical transmission’,
‘maternal–fetal transmission’, ‘intrauterine transmission’,
‘neonate’, ‘infant’ and ‘delivery’. Eligibility criteria
included laboratory-confirmed and/or clinically diagnosed
COVID-19, patient being pregnant on admission and
availability of clinical characteristics, including at least
one maternal, perinatal or neonatal outcome. Exclusion
criteria were non-peer-reviewed or unpublished reports,
unspecified date and location of the study, suspicion of duplicate reporting and unreported maternal or perinatal
outcomes. No language restrictions were applied.
Results We identified a high number of relevant case
reports and case series, but only 24 studies, including
a total of 324 pregnant women with COVID-19,
met the eligibility criteria and were included in the
systematic review. These comprised nine case series
(eight consecutive) and 15 case reports. A total of 20
pregnant patients with laboratory-confirmed COVID-19
were included in the case reports. In the combined data
from the eight consecutive case series, including 211
(71.5%) cases of laboratory-confirmed and 84 (28.5%)
of clinically diagnosed COVID-19, the maternal age
ranged from 20 to 44 years and the gestational age
on admission ranged from 5 to 41weeks. The most
common symptoms at presentation were fever, cough,
dyspnea/shortness of breath, fatigue and myalgia. The
rate of severe pneumonia reported amongst the case series
ranged from 0% to 14%, with the majority of the cases
requiring admission to the intensive care unit. Almost
all cases from the case series had positive computed
tomography chest findings. All six and 22 cases that
had nucleic-acid testing in vaginal mucus and breast
milk samples, respectively, were negative for severe acute
respiratory syndrome coronavirus 2 (SARS-CoV-2). Only
four cases of spontaneous miscarriage or termination were
reported. In the consecutive case series, 219/295 women
had delivered at the time of reporting and 78% of them
had Cesarean section. The gestational age at delivery
ranged from 28 to 41 weeks. Apgar scores at both 1 and
5 min ranged from 7 to 10. Only eight neonates had
birth weight <2500 g and nearly one-third of neonates
were transferred to the neonatal intensive care unit. There
was one case of neonatal asphyxia and death. In 155
neonates that had nucleic-acid testing in throat swab, all,
except three cases, were negative for SARS-CoV-2. There
were no cases of maternal death in the eight consecutive
case series. Seven maternal deaths, four intrauterine fetal
deaths (one with twin pregnancy) and two neonatal deaths
(twin pregnancy) were reported in a non-consecutive case
series of nine cases with severe COVID-19. In the case
reports, two maternal deaths, one neonatal death and two
cases of neonatal SARS-CoV-2 infection were reported.
Conclusions Despite the increasing number of published
studies on COVID-19 in pregnancy, there are insufficient
good-quality data to draw unbiased conclusions with
regard to the severity of the disease or specific
complications of COVID-19 in pregnant women, as
well as vertical transmission, perinatal and neonatal
complications. In order to answer specific questions in
relation to the impact of COVID-19 on pregnant women
and their fetuses, through meaningful good-quality
research, we urge researchers and investigators to
present complete outcome data and reference previously
published cases in their publications, and to record such
reporting when the data of a case are entered into one
or several registries.post-print1026 K
Rheological Behaviour of an Insoluble Lemon Fibre as Affected by Stirring, Temperature, Time and Storage
The final
publication is available at link.springer.comIn this work, the effect the preparation method (two different stirring systems at two temperatures and times), fibre concentration (between 2% and 3%), temperature (between 10 °C and 50 °C) and storage time (between 24 h and 50 days at 5 °C) had on the flow properties of a suspension of dietary lemon fibre prepared with a 45° Brix sucrose solution were evaluated. This information will be helpful in order to discover the best possibilities of using fibre to increase the viscosity of certain kinds of products, depending on the processing, storage and consumption conditions. The obtained results indicate that all the aspects which contribute to increase component solubilisation and the interaction of the insoluble fraction with the aqueous phase when preparing the suspension, such as a decrease in particle size, a rise in temperature or a longer homogenization time, entail a higher apparent viscosity. Moreover, favoring the solubilisation in the preparation process leads to a more stable rheological behaviour of the suspension during storage. As expected, the apparent viscosity of suspensions was dependent on the shear rate, concentration and temperature. A thixotropic behaviour of fibre suspension was only observed at a very low shear rate (5 s -1). © 2010 Springer Science + Business Media, LLC.Córdoba Sequeira, A.; Camacho Vidal, MM.; Martínez Navarrete, N. (2012). Rheological Behaviour of an Insoluble Lemon Fibre as Affected by Stirring, Temperature, Time and Storage. Food and Bioprocess Technology. 5(3):1083-1092. doi:10.1007/s11947-010-0478-2S1083109253Akdogan, H., & McHugh, T.-H. (2000). Flow characterization of peach products during extrusion. Food Engineering and Physical Properties, 65(3), 471–475.Alonso, M.-L., Larrodé, O., & Zapico, J. (1995). Rheological behaviour of infant foods. Journal of Texture Studies, 26, 193–202.Duran, L., & Costell, E. (1982). Rheology of apricot puree: Characterization of flow. Journal of Texture Studies, 13, 43–58.Flint O (1996) Microscopía de los alimentos. Manual de métodos prácticos utilizando la miscroscopía óptica. Ed. Acribia S-A, Zaragoza, 28, 108–111Grigelmo-Miguel, N., Gorinstein, S., & Martín-Belloso, O. (1999a). Characterisation of peach dietary fiber concentrate as food ingredient. Food Chemistry, 65, 175–181.Grigelmo-Miguel, N., Ibarz-Ribas, A., & Martín-Belloso, O. (1999b). Rheology of peach dietary fibre suspensions. Journal of Food Engineering, 39, 91–99.Guerrero S-N & Alzamora S-M. (1998). Effect of pH, temperature and glucose addition on flow behaviour of fruit purées: II. Peach, papaya and mango purées. Journal of Food Engineering, 37, 77–101.Guillon, F., & Champ, M. (2000). Structural and physical properties of dietary fibres, and consequences of processing on human physiology. Food Research International, 33, 233–245.Hahn, S.-J., Ree, T., & Eyring, G.-H. (1959). Flow mechanism of thixotropic substances. Industrial and Engineering Chemistry Research, 51, 856–857.Jongaroontaprangsee, S., Tritrong, W., & Chokanaporn, W. (2007). Effects of drying temperature and particle size on hydration properties of dietary fiber powder from lime and cabbage by-products. International Journal of Food Properties, 10, 887–897.Lario, Y., Sendra, E., Garcıa-Perez, J., Fuentes, C., Sayas-Barbera, E., Fernández-López, J., et al. (2004). Preparation of high dietary fiber powder from lemon juice by-products. Innovation of Food Science Emerging Technologies, 5, 113–117.Mahmoud M-I & Fugitt M (1996) Rheological properties of a calorically dense nutritional supplement as a function of nitrogen source and dietary fiber. In: IFT Annual Meeting. Book of Abstracts. 80A-26, 183Mizrahi, S. (1979). A review of the physicochemical approach to the analysis of the structural viscosity of fluid fruit products. Journal of Texture Studies, 10, 67–82.Paredes, M.-D.-C., Rao, M.-A., & Bourne, M.-C. (1998). Rheological characterization of salad dressings: 1. Steady shear, thixotropy and effect of temperature. Journal of Texture Studies, 19, 247–258.Raghavendra, S.-N., Ramachandra Swamy, S.-R., Rastogi, N.-K., Raghavarao, K.-S.-M.-S., Kumar, S., & Tharanathan, R.-N. (2006). Grinding characteristics and hydration properties of coconut residue: A source of dietary fiber. Journal of Food Engineering, 72, 281–286.Sakata, T., & Saito, M. (2007). Insoluble dietary fiber of wheat bran increased viscosity of pig whole cecal contents in vitro. Journal of Nutrition Science and Vitaminology, 53(4), 380–381.Saldaña, S., Martínez-Navarrete, N., & Chiralt, A. (2000). Caracterización Reológica de Alimentos de alta viscosidad. In P. Fito, A. Chiralt, A. Andrés, & N. Martínez-Navarrete (Eds.), Series de Ciencia e Ingeniería de Alimentos. Investigación del postgrado del IAD-DTA. Vol I (p. 383). Valencia: Editorial de la Universidad Politécnica de Valencia.Sangnark, A., & Noomhorm, A. (2003). Effect of particle sizes on functional properties of dietary fibre prepared from sugarcane bagasse. Food Chemistry, 80(2), 221–229
DETERMINACIÓN SEROLÓGICA DE LA INFECCIÓN CON Mycoplasma hyopneumoniae EN UNA GRANJA PORCINA DE LIMA
Se realizó un estudio serológico para determinar el momento de mayor infección con Mycoplasma hyopneumoniae de una granja porcina de crianza intensiva en la provincia de Lima, en el periodo abril-agosto del 2002. Se tomaron muestras quincenales de sangre en 30 animales desde el nacimiento hasta las 16 semanas de edad. Se utilizó la prueba comercial de ELISA Chekit®-Hyoptest-II para la detección de anticuerpos. El 66.3% (20/ 30) de los animales presentaron anticuerpos contra M. hyopeumoniae determinándose que el mayor porcentaje seroconvirtió a las 12 semanas, por lo que se concluye que el periodo crítico corresponde a las 9-10 semanas de edad donde el M. hyopneumoniae inicia la infección que condujo a la seroconversión. El sexo y número de partos de la madre no afectó el momento de la infección. Palabras clave: porcino, Mycoplasma hyopneumoniaeA serological study was conducted to identify the age of highest infection with Mycoplasma hyopneumoniae in pigs under an intensive rearing system in the Lima province, during the period April – August, 2002. Blood samples were collected fortnightly from birth till 16 months of age in 30 piglets. The commercial test ELISA Chekit®-Hyoptest- II was used for the detection of antibodies. The 66.3% (20/30) of the animals showed antibodies against M. hyopneumoniae. The critical period for starting the infection occurred at 9-10 weeks of age. Sex and number of parturition did not affect the time of initial infection
Validation of a methodology for grouping intakes of pressurized irrigation networks into sectors to minimize energy consumption
A methodology to optimise the amount of energy consumed in pressurized irrigation systems was presented by Jimenez-Bello et al. (2010a). These authors proposed grouping pressurized irrigation network intakes, each of the water turnouts resulting from a shared hydrant, into sectors via a genetic algorithm. In the present research, the methodology was applied and validated in a water users association. Several energy efficiency indicators were calculated and compared during five consecutive seasons (2006-2010). The first two seasons, when the methodology was not employed, were used as reference for the results obtained from 2008 onwards, when the methodology was applied to the management of irrigation network. Results obtained in seasons 2008-2010 showed that the average energy savings were 16% in comparisons to the 2006 season. However, it should be noted that the potential, theoretical savings, could have been as high as 22.3% if the modelled grouping networks would have been accurately followed. There was in fact some discrepancy between the theoretical model outputs and the final groupings due to some intake restrictions. In addition, during the irrigation campaigns, the number of irrigation intakes that operated within each sector was not always equal to the modelled sectoring, a fact that reduced the overall water users association energy efficiency. This occurred particularly during rainy periods, when some users deliberately decided to close their manual irrigation intakes valves. Overall, results showed the potential of the validated methodology for optimising energy use. However, the final overall system efficiency might depend on specific constraints that need to be taken into account when attempting to use model output predictions.This research was supported by funds from Interreg IV SUDOEB project "Telerieg" and from MICIIN project Rideco CSD2006-0067. The authors would like to thank the Company Tecnicas Valencianas del Agua (TECVASA) and the IMPIVA institute for their support in this research study.Jiménez Bello, MÁ.; Martínez Alzamora, F.; Castel, JR.; Intrigliolo Molina, DS. (2011). Validation of a methodology for grouping intakes of pressurized irrigation networks into sectors to minimize energy consumption. Agricultural Water Management. 102(1):46-53. https://doi.org/10.1016/j.agwat.2011.10.005S4653102
EFFECT OF TWO ANTIOXIDANTS (TEMPO AND TEMPOL) ON RAM SEMEN CRYOPRESERVATION USING THE TRIS EXTENDER
Se emplearon 32 muestras de semen procedentes de cuatro ovinos a fin de ser criopreservadas con la adición dos antioxidantes: Tempo (2,2,6,6 tetrametil-1-piperidiniloxil) y Tempol (4-hidroxi 2,2,6,6 tetrametil-1-piperidiniloxil), en concentraciones de 0.5, 1.0 y 2.5 mM, para evaluar el efecto postdescongelamiento que pudieran tener sobre la motilidad progresiva, la viabilidad e integridad acrosomal y la capacitación espermática prematura. En cada concentración de los dos antioxidantes y del grupo control se utilizó un dilutor en base a Tris, realizándose ocho repeticiones, cada una con cuatro muestras de semen. Los resultados obtenidos demuestran que la adición de Tempo a una concentración de 0.5 mM mejora significativamente la calidad del semen criopreservado en comparación con el grupo control (p<0.05), incrementado los porcentajes de motilidad progresiva (79 vs. 67%), viabilidad e integridad acrosomal (70 vs. 58%) y reduciendo la capacitación espermática prematura (9 vs.15%). Por otro lado, la adición de Tempol disminuyó la calidad seminal postdescongelamiento en comparación con el control. En conclusión, la adición de Tempo 0.5 mM en un dilutor en base a Tris, al finalizar la fase de enfriamiento, podría constituir una estrategia para mejorar la calidad de semen ovino criopreservado.Thirty-two semen samples from four rams were frozed using two antioxidants, Tempo (2,2,6,6 tetramethyl-1-piperidinyloxyl) and Tempol (4-hidroxi 2,2,6,6 tetramethyl-1- piperidinyloxyl), each one in concentrations of 0.5, 1.0, and 2.5 mM, to evaluate the effects on post-thawing motility, viability, acrosomal integrity, and earlier sperm capacitation. Eight replications for each antioxidant concentration and control group, were done using four semen samples per replication. Semen samples were diluted on a Tris extender. Results showed that Tempo 0.5 mM improved frozen semen quality in comparison with control group (p<0.05), by increasing progresive motility (79 vs. 67%), viability and acrosomal integrity (70 vs. 58%), and decreasing earlier sperm capacitation (9 vs. 15%). On the other hand, Tempol decreased frozen semen quality. In conclusion, the use of Tempo 0.5 mM on a Tris extender, at the end of the cooling process, could be an alternative for improving the quality of frozed ram semen
Random scenarios generation with minimun energy consumption model for sectoring optimization in pressurized irrigation networks using a simulated annealing approach
A pressurized irrigation network may operate in two ways, namely, on demand and organized under operating sectors. In the first case, the user decides when to irrigate, and the pumping station has to meet the discharge and pressure head requirements of the group of users that is demanding water at any time. In the second case, the operating hydrants at a given moment are previously established, which permits identification of scenarios related to lesser energy consumption. In this work, a new model was developed that identifies such scenarios. The optimization process is carried out by means of simulated annealing (SA). The model was applied to an example and the result obtained was compared with the same network operating on demand and sectorized using the criterion of hydrant elevation with respect to the pumping station. The scenario adopted for SA saved 11.8% and 15.5% in energy consumption compared with the two other scenarios, and decreased the installed power requirement by 38.3% and 21.6%, respectively.García Prats, A.; Guillem Picó, S.; Martínez Alzamora, F.; Jiménez Bello, MA. (2012). Random scenarios generation with minimun energy consumption model for sectoring optimization in pressurized irrigation networks using a simulated annealing approach. Journal of Irrigation and Drainage Engineering. 138(7):613-624. doi:10.1061/(ASCE)IR.1943-4774.0000452S613624138
The Legionella effector WipB is a translocated Ser/Thr phosphatase that targets the host lysosomal nutrient sensing machinery
Legionella pneumophila infects human alveolar macrophages and is responsible for Legionnaire’s disease, a severe form of pneumonia. L. pneumophila encodes more than 300 putative effectors, which are translocated into the host cell via the Dot/Icm type IV secretion system. These effectors highjack the host’s cellular processes to allow bacterial intracellular growth and replication. Here we adopted a multidisciplinary approach to investigate WipB, a Dot/Icm effector of unknown function. The crystal structure of the N-terminal domain at 1.7 Å resolution comprising residues 25 to 344 revealed that WipB harbours a Ser/Thr phosphatase domain related to the eukaryotic phospho-protein phosphatase (PPP) family. The C-terminal domain (residues 365–524) is sufficient to pilot the effector to acidified LAMP1-positive lysosomal compartments, where WipB interacts with the v-ATPase and the associated LAMTOR1 phosphoprotein, key components of the lysosomal nutrient sensing (LYNUS) apparatus that controls the mammalian target of rapamycin (mTORC1) kinase complex at the lysosomal surface. We propose that WipB is a lysosome-targeted phosphatase that modulates cellular nutrient sensing and the control of energy metabolism during Legionella infection
The Peripheral Arterial disease study (PERART/ARTPER): prevalence and risk factors in the general population
<p>Abstract</p> <p>Background</p> <p>The early diagnosis of atherosclerotic disease is essential for developing preventive strategies in populations at high risk and acting when the disease is still asymptomatic. A low ankle-arm index is a good marker of vascular events and may be diminished without presenting symptomatology (silent peripheral arterial disease). The aim of the study is to know the prevalence and associated risk factors of peripheral arterial disease in the general population.</p> <p>Methods</p> <p>We performed a cross-sectional, multicentre, population-based study in 3786 individuals >49 years, randomly selected in 28 primary care centres in Barcelona (Spain). Peripheral arterial disease was evaluated using the ankle-arm index. Values < 0.9 were considered as peripheral arterial disease.</p> <p>Results</p> <p>The prevalence (95% confidence interval) of peripheral arterial disease was 7.6% (6.7-8.4), (males 10.2% (9.2-11.2), females 5.3% (4.6-6.0); <it>p </it>< 0.001).</p> <p>Multivariate analysis showed the following risk factors: male sex [odds ratio (OR) 1.62; 95% confidence interval 1.01-2.59]; age OR 2.00 per 10 years (1.64-2.44); inability to perform physical activity [OR 1.77 (1.17-2.68) for mild limitation to OR 7.08 (2.61-19.16) for breathless performing any activity]; smoking [OR 2.19 (1.34-3.58) for former smokers and OR 3.83 (2.23-6.58) for current smokers]; hypertension OR 1.85 (1.29-2.65); diabetes OR 2.01 (1.42-2.83); previous cardiovascular disease OR 2.19 (1.52-3.15); hypercholesterolemia OR 1.55 (1.11-2.18); hypertriglyceridemia OR 1.55 (1.10-2.19). Body mass index ≥25 Kg/m<sup>2 </sup>OR 0.57 (0.38-0.87) and walking >7 hours/week OR 0.67 (0.49-0.94) were found as protector factors.</p> <p>Conclusions</p> <p>The prevalence of peripheral arterial disease is low, higher in males and increases with age in both sexes. In addition to previously described risk factors we found a protector effect in physical exercise and overweight.</p
- …