428 research outputs found
Biobased catalyst in biorefinery processes: Sulphonated hydrothermal carbon for glycerol esterification
Sulphonated hydrothermal carbon (SHTC), obtained from D-glucose by mild hydrothermal carbonisation
and subsequent sulphonation with sulphuric acid, is able to catalyse the esterification of glycerol with dif-
ferent carboxylic acids, namely, acetic, butyric and caprylic acids. Product selectivity can be tuned by sim-
ply controlling the reaction conditions. On the one hand, SHTC provides one of the best selectivity towards 20 monoacetins described up to now without the need for an excess of glycerol. On the other hand, excellent selectivity towards triacylglycerides (TAG) can be obtained, beyond those described with other solid cata-
lysts, including well-known sulphonic resins. Recovery of the catalyst showed partial deactivation of the
solid. The formation of sulphonate esters on the surface, confirmed by solid state NMR, was the cause of
this behaviour. Acid treatment of the used catalyst, with subsequent hydrolysis of the surface sulphonate 25 esters, allows SHTC to recover its activity. The higher selectivity towards mono- and triesters and its renewable origin makes SHTC an attractive catalyst in biorefinery processe
Immunoparasitological Diagnosis Of Strongyloides Stercoralis In Garbage Collectors In UberlĂąndia, Mg, Brazil
The objective of this study was to determine the presence of Strongyloides stercoralis in urban garbage collectors through the use of immunological and parasitological methods. A total of 92 individuals were evaluated from August, 1997, to June, 1998. For the parasitological diagnosis Baermann and Lutz' methods were applied. The immunological diagnosis involved the indirect fluorescence antibody test (IFAT) and the enzyme-linked immunosorbent assay (ELISA) to detect specific IgG antibodies. Of the 92 workers examined, six (6.5%) were infected with larvae of S. stercoralis. The IFAT detected 19 (16.3%) and the ELISA 17 (18.5%) positive serum samples. The differences between the results of parasitological and immunological methods were statistically significant (p<0.05). These results demonstrate that there is a need to improve the health conditions of this category of city employees.6203/04/15180182CONCHA, R., HARRINGTON, J.R.W., ROGERS, A.L., Intestinal strongyloidiasis: Recognition, management and determinants of outcome (2005) J Clin Gastroenterol, 39, pp. 203-211SIDDIQUI, A.A., BERK, S.L., Diagnosis of Strongyloides stercoralis infection (2001) Clin Infect Dis, 33, pp. 1040-1047FERREIRA, M., Strongyloidiasis and acquired immunodeficiency syndrome (2003) Enf Emerg, 5, pp. 18-26VADLAMUDI, R.S., CHI, D.S., KRISHANASWAMY, G., Intestinal strongyloidiasis and hyperinfection syndrome (2006) Clin Mol Allergy, 4, pp. 1-13BAERMANN G. Eine Einfache methode zur auffindung von Ankylostomum (Nematoden) larven in Erdproben. Mededeel mit h. Geneesk Lab Weltvreden Feestbundel, Batavia, 1917, p. 41-7LUTZ, A.V., Schistosoma mansoni e a schistosomose, Segundo observaçÔes feitas no Brasil. (1919) Mem Inst Oswaldo Cruz, 11, pp. 121-125COSTA-CRUZ, J.M., BULLAMAH, C.B., GONĂALVEZ-PIRES, M.R.F., Cryo-microtome sections of coproculture larvae of Strongyloides stercoralis and Strongyloides ratti as antigen sources for the immunodiagnosis of human strongyloidiasis (1997) Rev Inst Med Trop SĂŁo Paulo, 39, pp. 313-317MACHADO, E.R., UETA, M.T., GONĂALVES-PIRES, M.R.F., Strongyloides venezuelensis alkaline extract for the diagnosis of human strongyloidiasis by enzyme-linked immunosorbent assay (2003) Mem Inst Oswaldo Cruz, 98, pp. 849-853MACHADO, E.R., COSTA-CRUZ, J.M., Strongyloides stercoralis and other enteroparasites in children at UberlĂąndia City, state of Minas Gerais, Brazil (1998) Mem Inst Oswaldo Cruz, 93, pp. 161-164PAULA, F.M., CASTRO, E., GONĂALVES-PIRES, M.R.F., Parasitological and immunological diagnoses of strongyloidiasis in immunocompromised and nonimmunocompromised children at UberlĂąndia City, state of Minas Gerais, Brazil (2000) Rev Inst Med Trop SĂŁo Paulo, 42, pp. 51-55OLIVEIRA, L.C.M., RIBEIRO, C.T., MENDES, D.M., Frequency of Strongyloides stercoralis in alcoholics (2002) Mem Inst Oswaldo Cruz, 97, pp. 119-121LINDO, J.F., CONWAY, D.J., ATKINS, N.S., Prospective evaluation of enzyme-linked immunosorbent assay and immunoblot methods for the diagnosis of endemic Strongyloides stercoralis infection (1994) Am J Trop Med Hyg, 51, pp. 175-179CLARK, C.S., LINNEMANN Jr, C.C., CLARK, J.G., Enteric parasites in workers occupationally exposed to sewage (1984) J Occup Med, 26, pp. 273-275SCHLOSSER, O., RALL, D., LAURECEAU, M.-N., Intestinal parasite carriage in workers exposed to sewage (1999) Eur J Epidemiol, 15, pp. 261-265GOMES, T.C., ALMEIDA, M.F., MUIRA, L.A., Helmintoses intestinais em população de rua da cidade do Rio de Janeiro. (2002) Rev Soc Bras Med Trop, 35, pp. 531-53
Field-induced XY behavior in the S=1/2 antiferromagnet on the square lattice
Making use of the quantum Monte Carlo method based on the worm algorithm, we
study the thermodynamic behavior of the S=1/2 isotropic Heisenberg
antiferromagnet on the square lattice in a uniform magnetic field varying from
very small values up to the saturation value. The field is found to induce a
Berezinskii-Kosterlitz-Thouless transition at a finite temperature, above which
a genuine XY behavior in an extended temperature range is observed. The phase
diagram of the system is drawn, and the thermodynamic behavior of the specific
heat and of the uniform and staggered magnetization is discussed in sight of an
experimental investigation of the field-induced XY behavior.Comment: 4 pages, 4 figure
Novel sources of Flavor Changed Neutral Currents in the model
Sources of Flavor Changed Neutral Currents (FCNC) naturally emerge from a
well motivated framework called 3-3-1 with right-handed neutrinos model,
for short, mediated by an extra neutral gauge boson .
Following previous works we calculate these sources and in addition we derive
new ones coming from CP-even and -odd neutral scalars which appear due to their
non-diagonal interactions with the physical standard quarks. Furthermore we
show that bounds related to the neutral mesons systems and may be significantly strengthened in the presence of these new
interactions allowing us to infer stronger constraints on the parameter space
of the model.Comment: Published version. 10 pages, 6 figure
Low Temperature Static and Dynamic Behavior of the Two-Dimensional Easy-Axis Heisenberg Model
We apply the self-consistent harmonic approximation (SCHA) to study static
and dynamic properties of the two-dimensional classical Heisenberg model with
easy-axis anisotropy. The static properties obtained are magnetization and spin
wave energy as functions of temperature, and the critical temperature as a
function of the easy-axis anisotropy. We also calculate the dynamic correlation
functions using the SCHA renormalized spin wave energy. Our analytical results,
for both static properties and dynamic correlation functions, are compared to
numerical simulation data combining cluster-Monte Carlo algorithms and Spin
Dynamics. The comparison allows us to conclude that far below the transition
temperature, where the SCHA is valid, spin waves are responsible for all
relevant features observed in the numerical simulation data; topological
excitations do not seem to contribute appreciably. For temperatures closer to
the transition temperature, there are differences between the dynamic
correlation functions from SCHA theory and Spin Dynamics; these may be due to
the presence of domain walls and solitons.Comment: 12 pages, 14 figure
Possible Gauge Theoretic Origin for Quark-Lepton Complementarity
Similarity between the weak interaction properties of quarks and leptons has
led to suggestions that the origin of lepton mixing angles may be related to
those of quarks. In this paper, we present a gauge model based on group that leads to a new form for the quark
lepton complementarity which predicts the solar neutrino mixing angle in terms
of the Cabibbo angle for the case of inverted mass hierarchy for neutrinos. We
also indicate how these ideas can be implemented in an inspired
trinification model, which is more
closely allied to string theory by the AdS/CFT correspondence.Comment: 9 pages, latex, no figures; presentation improved; results unchanged;
minor typos correcte
Chronic wasting disease risk assessment in Portugal: results and future work.
NĂșmero da Revista Portuguesa de CiĂȘncias VeterinĂĄrias, dedicado Ă publicação dos "Proceedings of the 10th Iberian Congress on Prions" que decorreu em Vila Real, Portugal de 19 1 20 de maio de 2022.Chronic wasting disease risk assessment in Portugal: results and future work.This work was supported by the project WastingPrionRisk [POCI-01-0145-FEDER-029947 / PTDC/
CVT-CVT/29947/2017] funded by the Portuguese Foundation for Science and Technology (FCT). FCT PhD grant [SFRH/BD/146961/2019] financed by FCT through FSE (Fundo Social Europeu). This work was also supported by national funds [UIDB/CVT/00772/2020], [LA/P/0059/2020] and [UIDB/04033/2020] by FCT.info:eu-repo/semantics/publishedVersio
âThat's cool, youâre a musician and you drinkâ: Exploring entertainersâ accounts of their unique workplace relationship with alcohol
This qualitative research investigates the alcohol experiences of entertainers who perform within licensed premises. Previous, mainly quantitative, studies have found that entertainers, specifically musicians, are an occupational group who drink excessively. This qualitative study draws on a wider sample of entertainers to examine their accounts of drinking in the workplace and the explanations they provide for this. We conducted individual semi-structured interviews (n = 24) with band-members, variety acts and DJs in Glasgow, Scotland. This revealed a workplace characterised by continual opportunities for often free alcohol consumption. Unlike most occupations, for entertainers âdrinking-on-the-jobâ was normative, expected, and sometimes encouraged by peers, the public, employers or sponsors. Entertainers also experienced performance-related incentives to drink before, during and/or after a show; including anxiety, matching their intoxication level to the audience's, and âreward-drinkingâ. This qualitative research confirms the unique nature of the entertainer-alcohol link, even in comparison to that found within other leisure industry occupations. While providing some explanation as to why entertainers might drink excessively, participantsâ accounts also suggested potential strategies for avoiding the negative outcomes of workplace drinking
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