1,234 research outputs found
Risk of Covid-19 in shielded and nursing care home patients: cohort study in general practice
Background: Covid-19 cases were first detected in the UK in January 2020 and vulnerable patients were asked to shield from March to reduce their risk of Covid-19 infection. Aim: To determine the risk and determinants of Covid-19 diagnosis in shielded vs. non-shielded groups adjusted for key comorbidities not explained by shielding. Design: Retrospective cohort study of adults with COVID-19 infection between 1/2/20-15/5/20 in West London. Method: Individuals diagnosed with Covid-19 were identified in SystmOne records using clinical codes. Infection risks were adjusted for socio-demographic factors, nursing home status and comorbidities. Results: Of 57,713 adults, 573 (1%) individuals were identified as shielded and 1,074 adults had documented Covid-19 infections (1.9%). Covid-19 infection rate in the shielded group individuals compared with non-shielded adult individuals was 6.5 % (37/573) vs. 1.8 % (1,037/57, 140), p30kg/m2) 1.39 (1.18-1.63) p<0.001, and age 1.02 (1.01-1.02) p<0.001. Male gender was associated with lower risk of Covid-19 infection: 0.71 (0.62-0.82) p<0.001. Conclusion: Shielded individuals had a higher Covid-19 infection rate compared with non-shielded individuals, after adjusting for socio-demographic factors, nursing home status, and comorbidities
Seed germination and seedling establishment of some wild almond species
Wild almond species are important genetic resources for resistance to unsuitable condition, especially drought stress. They have been used traditionally as rootstocks in some areas of Iran. So far, 21 wild almond species and 7 inter species hybrids have been identified in Iran. To study seed germination and seedling establishment of some of these species, three separate experiments were designed. In the first experiment, the application of gibberellic acid (GA3) (0, 250, 500 and 750 ppm) for 24 h was studied on germination characteristics of four wild almond accessions after stratification at 5 ± 0.5°C in Perlite media. Germination percentage, index vigor and root initiation factors were different in almond accessions, but were not affected by hormonal treatments. In the second experiment, seeds of another six wild almond accessions were stratified to compare their germination ability. Germination percentage, index vigor and root initiation were different among accessions significantly. In the last experiment, the establishment and vigor of 14 accessions from eight almond species have been evaluated in plastic bags in outdoor conditions. Two ecotypes of Prunus spp. had the highest stem diameter and length at all growing stages.Keywords: Amygdalus, germination percentage, index vigor, root initiation, stem length, stem diameter
Activated biochars as sustainable and effective supports for hydrogenations
Activated biochars were obtained from pyrolysis and CO2-physical activation of four different biomasses including tannery shaving waste (T), vine wood waste (W), barley waste (B) and Sargassum, brown macroalgae of Venice lagoon (A). The potential of obtained carbonaceous materials as the supports of Ni,Al catalysts was investigated in levulinic acid (LA) conversion to Îł-valerolactone (GVL) as a model hydrogenation reaction. Al-containing species as the Lewis acid sites for the dehydration step were incorporated to the supports using wet impregnation or precipitation. Ni as a hydrogenation active phase was added to the supports via wet impregnation. Biochar-based supports and catalysts were characterized by AAS, elemental analysis, FTIR, N2 physisorption, XRD, SEM, EDS, TEM, He-TPD, NH3-TPD and TPR techniques. The catalysts were tested for LA hydrogenation to GVL in a batch system and aqueous medium. The results showed that Ni supported on activated biochar was not active due to a lack of Lewis acid sites for dehydration. Precipitated Al-containing species on the biochar-based supports demonstrated a better catalytic performance in the reaction compared to impregnated one because of different interactions with the support and Ni species. Among different supports, the activated biochars obtained from T and W acted as the best ones. A higher catalytic efficiency was strongly influenced by the chemical (aromaticity and stability, presence of N,O-doped and functional groups), textural (the porous texture and surface area), and morphological (higher dispersion of active phases) properties of activated biochars obtained from different biomasses with different natures
New constraints for QCD matter from improved Bayesian parameter estimation in heavy-ion collisions at LHC
The transport properties of quark-gluon plasma created in relativistic heavy-ion collisions are quantified by an improved global Bayesian analysis using the CERN Large Hadron Collider Pb-Pb data at root s(NN) = 2.76 and 5.02 TeV. The results show that the uncertainty of the extracted transport coefficients is significantly reduced by including new sophisticated collective flow observables from two collision energies for the first time. This work reveals the stronger temperature dependence of specific shear viscosity, a lower value of specific bulk viscosity, and a higher hadronization switching temperature than in the previous studies. The sensitivity analysis confirms that the precision measurements of higher-order harmonic flow and their correlations are crucial in extracting accurate values of the transport properties. (C) 2022 The Author(s). Published by Elsevier B.V.Peer reviewe
MCM-41 supported co-based bimetallic catalysts for aqueous phase transformation of glucose to biochemicals
The transformation of glucose into valuable biochemicals was carried out on different MCM-41-supported metallic and bimetallic (Co, Co-Fe, Co-Mn, Co-Mo) catalysts and under different reaction conditions (150 °C, 3 h; 200 °C, 0.5 h; 250 °C, 0.5 h). All catalysts were characterized using N2 physisorption, Temperature Programmed Reduction (TPR), Raman, X-ray Diffraction (XRD) and Temperature Programmed Desorption (TPD) techniques. According to the N2-physisorption results, a high surface area and mesoporous structure of the support were appropriate for metal dispersion, reactant diffusion and the formation of bioproducts. Reaction conditions, bimetals synergetic effects and the amount and strength of catalyst acid sites were the key factors affecting the catalytic activity and biochemical selectivity. Sever reaction conditions including high temperature and high catalyst acidity led to the formation mainly of solid humins. The NH3-TPD results demonstrated the alteration of acidity in different bimetallic catalysts. The 10Fe10CoSiO2 catalyst (MCM-41 supported 10 wt. þ, 10 wt. %Co) possessing weak acid sites displayed the best catalytic activity with the highest carbon balance and desired product selectivity in mild reaction condition. Valuable biochemicals such as fructose, levulinic acid, ethanol and hydroxyacetone were formed over this catalyst
MCM-41 Supported Co-based Bimetallic Catalysts for Aqueous Phase Transformation of Glucose in Biochemicals
The transformation of glucose into valuable biochemicals was carried out on different MCM-41-supported metallic and bimetallic (Co, Co-Fe, Co-Mn, Co-Mo) catalysts and under different reaction conditions (150 °C, 3 h; 200 °C, 0.5 h; 250 °C, 0.5 h). All catalysts were characterized using N2 physisorption, Temperature Programmed Reduction (TPR), Raman, X-ray Diffraction (XRD) and Temperature Programmed Desorption (TPD) techniques. According to the N2-physisorption results, a high surface area and mesoporous structure of the support were appropriate for metal dispersion, reactant diffusion and the formation of bioproducts. Reaction conditions, bimetals synergetic effects and the amount and strength of catalyst acid sites were the key factors affecting the catalytic activity and biochemical selectivity. Sever reaction conditions including high temperature and high catalyst acidity led to the formation mainly of solid humins. The NH3-TPD results demonstrated the alteration of acidity in different bimetallic catalysts. The 10Fe10CoSiO2 catalyst (MCM-41 supported 10 wt.þ, 10 wt.%Co) possessing weak acid sites displayed the best catalytic activity with the highest carbon balance and desired product selectivity in mild reaction condition. Valuable biochemicals such as fructose, levulinic acid, ethanol and hydroxyacetone were formed over this catalyst
Ingestion rate and feeding behavior of guppy (Poecilia reticulata Peters) larvae fed on nauplii of Artemia urmiana and Artemia franciscana
Artemia nauplii, despite their marine origin, have a good potential for application in the freshwater ornamental fish culture. In this study, two types of Artemia urmiana and Artemia franciscana were used for feeding of Guppy (Poecilia reticulata Peters) Larvae. Newly hatched fresh nauplii at three different densities of 3, 6, and 12 ind./ml as live feeds were compared for measuring larval ingestion rate. Results showed that type and density of Artemia nauplii had significant effects on ingestion rate (P<0.05). The average ingestion rate in larvae which maintain 12 hours starvation (first set of experiment) were 36, 244, and 664 ind./larvae/day for A. urmiana, correspondingly, for A. franciscana were 160, 480, and 880 ind./larvae/day at densities of 3, 6, and 12 ind./ml, respectively. The average ingestion rate of guppy larvae with 24, 48 and 72 hours feeding preconditions (2^nd, 3^rd and 4^th set of experiment) were significantly (P<0.05) decreased. After starvation, the ingestion rate of guppy larvae fed A. urmiana had range 22-54, 86-102, and 148-188 ind./larvae/day, correspondingly, for A. franciscana 66-100, 100-260, and 200-224 ind./larvae/day at 3, 6, and 12 ind./ml, respectively. The use of suitable densities of 6 and 12 ind./ml from Artemia nauplii could increase efficiency of utilization and also improve Guppy larvae production
Generating GHZ state in 2m-qubit spin network
We consider a pure 2m-qubit initial state to evolve under a particular
quantum me- chanical spin Hamiltonian, which can be written in terms of the
adjacency matrix of the Johnson network J(2m;m). Then, by using some techniques
such as spectral dis- tribution and stratification associated with the graphs,
employed in [1, 2], a maximally entangled GHZ state is generated between the
antipodes of the network. In fact, an explicit formula is given for the
suitable coupling strengths of the hamiltonian, so that a maximally entangled
state can be generated between antipodes of the network. By using some known
multipartite entanglement measures, the amount of the entanglement of the final
evolved state is calculated, and finally two examples of four qubit and six
qubit states are considered in details.Comment: 22 page
A general algorithm for manipulating non-linear and linear entanglement witnesses by using exact convex optimization
A generic algorithm is developed to reduce the problem of obtaining linear
and nonlinear entanglement witnesses of a given quantum system, to convex
optimization problem. This approach is completely general and can be applied
for the entanglement detection of any N-partite quantum system. For this
purpose, a map from convex space of separable density matrices to a convex
region called feasible region is defined, where by using exact convex
optimization method, the linear entanglement witnesses can be obtained from
polygonal shape feasible regions, while for curved shape feasible regions,
envelope of the family of linear entanglement witnesses can be considered as
nonlinear entanglement witnesses. This method proposes a new methodological
framework within which most of previous EWs can be studied. To conclude and in
order to demonstrate the capability of the proposed approach, besides providing
some nonlinear witnesses for entanglement detection of density matrices in
unextendible product bases, W-states, and GHZ with W-states, some further
examples of three qubits systems and their classification and entanglement
detection are included. Also it is explained how one can manipulate most of the
non-decomposable linear and nonlinear three qubits entanglement witnesses
appearing in some of the papers published by us and other authors, by the
method proposed in this paper. Keywords: non-linear and linear entanglement
witnesses, convex optimization. PACS number(s): 03.67.Mn, 03.65.UdComment: 37 page
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