3,616 research outputs found
Galaxy Clusters in the Line of Sight to Background Quasars: II. Environmental effects on the sizes of baryonic halo sizes
Based on recent results on the frequency of MgII absorption line systems in
the "QSO behind RCS clusters" survey (QbC), we analyse the effects of the
cluster environment on the sizes of baryonic haloes around galaxies. We use two
independent models, i) an empirical halo occupation model which fits current
measurements of the clustering and luminosity function of galaxies at low and
high redshifts, and ii) the GALFORM semi-analytic model of galaxy formation,
which follows the evolution of the galaxy population from first principles,
adjusted to match the statistics of low and high redshift galaxies. In both
models we constrain the MgII halo sizes of field and cluster galaxies using
observational results on the observed MgII statistics. Our results for the
field are in good agreement with previous works, indicating a typical \mgii\
halo size of $r_MgII ~ 50h_71^-1kpc in the semi-analytic model, and slightly
lower in the halo occupation number approach. For the cluster environment, we
find that both models require a median MgII halo size of r_MgII< 10h_71^-1kpc
in order to reproduce the observed statistics on absorption line systems in
clusters of galaxies. Based on the Chen & Tinker (2008) result that stronger
systems occur closer to the MgII halo centre, we find that strong absorption
systems in clusters of galaxies occur at roughly a fixed fraction of the
cold-warm halo size out to 1h_71^-1Mpc from the cluster centres. In contrast,
weaker absorption systems appear to occur at progressively shorter relative
fractions of this halo as the distance to the cluster centre decreases.Comment: 12 pages, 8 figures, accepted for publication in MNRA
The chronic bronchitis phenotype in subjects with and without COPD: the PLATINO study
Little information exists regarding the epidemiology of the chronic bronchitis phenotype in unselected chronic obstructive pulmonary disease (COPD) populations. We examined the prevalence of the chronic bronchitis phenotype in COPD and non-COPD subjects from the PLATINO study, and investigated how it is associated with important outcomes.Post-bronchodilator forced expiratory volume in 1 s/forced vital capacity = 2 yrs. We also analysed another definition: cough and phlegm on most days, at least 3 months per year for >= 2 yrs.Spirometry was performed in 5,314 subjects (759 with and 4,554 without COPD). the proportion of subjects with and without COPD with chronic bronchitis defined as phlegm on most days, at least 3 months per year for >= 2 yrs was 14.4 and 6.2%, respectively. Using the other definition the prevalence was lower: 7.4% with and 2.5% without COPD. Among subjects with COPD, those with chronic bronchitis had worse lung function and general health status, and had more respiratory symptoms, physical activity limitation and exacerbations.Our study helps to understand the prevalence of the chronic bronchitis phenotype in an unselected COPD population at a particular time-point and suggests that chronic bronchitis in COPD is possibly associated with worse outcomes.Boehringer Ingelheim GmbHAsociacion Latinoamericana de ToraxCent Univ Venezuela, Hosp Univ Caracas, Serv Neumonol, Fac Med, Caracas 1030, VenezuelaUCLA Sch Publ Hlth, Los Angeles, CA USAUniv Republica, Fac Med, Hosp Maciel, Montevideo, UruguayInst Resp Dis, Mexico City, DF, MexicoUniversidade Federal de São Paulo, São Paulo, BrazilUniv Fed Pelotas, Fac Med, Pelotas, BrazilPontificia Univ Catolica Chile, Fac Med, Dept Salud Publ, Santiago, ChilePontificia Univ Catolica Chile, Fac Med, Catedra Neumol, Santiago, ChileUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc
Identification and Validation of Compounds Targeting Leishmania major Leucyl-Aminopeptidase M17
Leishmaniasis is a neglected tropical disease; there is currently no vaccine and treatment is reliant upon a handful of drugs suffering from multiple issues including toxicity and resistance. There is a critical need for development of new fit-for-purpose therapeutics, with reduced toxicity and targeting new mechanisms to overcome resistance. One enzyme meriting investigation as a potential drug target in Leishmania is M17 leucyl-aminopeptidase (LAP). Here, we aimed to chemically validate LAP as a drug target in L. major through identification of potent and selective inhibitors. Using RapidFire mass spectrometry, the compounds DDD00057570 and DDD00097924 were identified as selective inhibitors of recombinant Leishmania major LAP activity. Both compounds inhibited in vitro growth of L. major and L. donovani intracellular amastigotes, and overexpression of LmLAP in L. major led to reduced susceptibility to DDD00057570 and DDD00097924, suggesting that these compounds specifically target LmLAP. Thermal proteome profiling revealed that these inhibitors thermally stabilized two M17 LAPs, indicating that these compounds selectively bind to enzymes of this class. Additionally, the selectivity of the inhibitors to act on LmLAP and not against the human ortholog was demonstrated, despite the high sequence similarities LAPs of this family share. Collectively, these data confirm LmLAP as a promising therapeutic target for Leishmania spp. that can be selectively inhibited by drug-like small molecules.</p
Health status perception and airflow obstruction in five Latin American cities: the PLATINO study
Background: COPD is a highly prevalent disease but underdiagnosed, undertreated and possibly under-recognized by patients. Limited information exists regarding patients' perception of COPD severity. We compared patients' general, health status perception, degree of breathlessness and physical activity limitation with the severity of their respiratory condition measured by airway obstruction, in a population-based sample.Methods: We used postbronchodilator FEV(1)/FVC < 0.70 to define COPD. Patients' perception of their general. health status was derived from the question in general, you would say that your health is: excellent, very good, good, fair or poor?Results: Spirometry was performed in 5314 subjects: an FEV(1)/FVC ratio below 0.70 was found in 759 subjects. in persons with COPD, general. health status decreased with increasing GOLD stages. Over one-half of subjects with stage 2 and one third of those with stages 3 and 4 reported their health status as good to excellent. There was also a disparity between airway obstruction severity and breathlessness intensity. Although the more severe COPD stages were frequently associated with significant compromise of work and everyday activities, patients often tended to provide an optimistic self evaluation of their health status.Conclusions: the discrepancy observed between general health status, dyspnea severity, physical activity limitation and airway obstruction most likely reflect patients' underperception of disease severity, emphasizing the need for improving case-finding measures and multi-component evaluation of COPD subjects. (C) 2009 Elsevier B.V. All rights reserved.Boehringer Ingelheim GmbHCent Univ Venezuela, Hosp Univ Caracas, Serv Neumonol, Caracas 1030, VenezuelaUniv Calif Los Angeles, Sch Publ Hlth, Los Angeles, CA 90066 USAInst Resp Dis, Mexico City 14080, DF, MexicoUniv Republica, Hosp Maciel, Montevideo, UruguayUniversidade Federal de São Paulo, BR-04021070 São Paulo, BrazilPontificia Univ Catolica Chile, Dept Salud Publ, Santiago, ChilePontificia Univ Catolica Chile, Catedra Neumol, Santiago, ChileUniv Fed Pelotas, Fac Med, BR-96030002 Pelotas, RS, BrazilUniversidade Federal de São Paulo, BR-04021070 São Paulo, BrazilWeb of Scienc
Chronic obstructive pulmonary disease and body mass index in five Latin America cities: the PLATINO study
Background: the body mass index (BMI) is a prognostic factor for chronic obstructive pulmonary disease (COPD). Despite its importance, little information is available regarding BMI alteration in COPD from a population-based study. We examined characteristics by BMI categories in the total and COPD populations in five Latin-American cities, and explored the factors influencing BMI in COPD.Methods: COPD was defined as a postbronchodilator forced expiratory volume in the first second/forced vital capacity (FEV(1)/FVC)= 30.0 kg/m(2)).Results: Interviews were completed in 5571 subjects from 6711 eligible individuals, and spirometry was performed in 5314 subjects. There were 759 subjects with COPD and 4555 without COPD. Compared with the non-COPD group, there was a higher proportion of COPD subjects in the underweight and normal weight categories, and a lower proportion in the obese category. Over one-half COPD subjects had BMI over 25 kg/m(2). No differences in BMI strata among countries were found in COPD subjects. Factors associated with lower BMI in mates with COPD were aging, current smoking, and global initiative for chronic obstructive lung disease (GOLD) stages III - IV, whereas wheeze and residing in Santiago and Montevideo were associated with higher BMI. in females with COPD, current smoking, lower education, and GOLD stages II - IV were associated with lower BMI, while dyspnea and wheeze were associated with higher BMI.Conclusions: BMI alterations are common in COPD with no significant differences among countries. Current smoking, age, GOLD stages, education level, residing in Santiago and Montevideo, dyspnea and wheeze were independently associated with BMI in COPD. (c) 2008 Elsevier B.V. All rights reserved.Cent Univ Venezuela, Fac Med, Hosp Univ Caracas, Serv Neumonol, Caracas 1030, VenezuelaInst Resp Dis, Mexico City 14080, DF, MexicoUniversidade Federal de São Paulo, BR-04021070 São Paulo, BrazilUniv Republica, Hosp Maciel, Fac Med, Montevideo 2610, UruguayPontificia Univ Catolica Chile, Fac Med, Dept Salud Publ, Santiago, ChileUniv Calif Los Angeles, Sch Publ Hlth, Los Angeles, CA 90066 USAUniv Fed Pelotas Duque Caxias, Fac Med, Pelotas, RS, BrazilUniversidade Federal de São Paulo, BR-04021070 São Paulo, BrazilWeb of Scienc
Tuberculosis and airflow obstruction: evidence from the PLATINO study in Latin America
The aim of the present study was to evaluate the association between history of tuberculosis and airflow obstruction.A population-based, multicentre study was carried out and included 5,571 subjects aged >= 40 yrs living in one of five Latin American metropolitan areas: São Paulo (Brazil); Montevideo (Uruguay); Mexico City (Mexico); Santiago (Chile); and Caracas (Venezuela). Subjects performed pre- and post-bronchodilator spirometry and were asked whether they had ever been diagnosed with tuberculosis by a physician.The overall prevalence of airflow obstruction (forced expiratory volume in one second/forced vital capacity post-bronchodilator < 0.7) was 30.7% among those with a history of tuberculosis, compared with 13.9% among those without a history. Males with a medical history of tuberculosis were 4.1 times more likely to present airflow obstruction than those without such a diagnosis. This remained unchanged after adjustment for confounding by age, sex, schooling, ethnicity, smoking, exposure to dust and smoke, respiratory morbidity in childhood and current morbidity. Among females, the unadjusted and adjusted odds ratios were 2.3 and 1.7, respectively.In conclusion, history of tuberculosis is associated with airflow obstruction in Latin American middle-aged and older adults.Univ Fed Pelotas, BR-96020220 Pelotas, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilNatl Inst Resp Dis, Mexico City, DF, MexicoUniv Republica, Montevideo, UruguayCatholic Univ Chile, Santiago, ChileCent Univ Venezuela, Caracas, VenezuelaUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc
Quasars probing intermediate redshift star-forming galaxies
We present a sample of 46 [OIII]-emitting galaxies at z<0.8 detected in the
fibre spectra of quasars from the SDSS-DR7 through an automatic search
procedure. We also detect [OII] and Hb emission lines from most of these
galaxies in the SDSS spectra. We study both the emission and absorption
properties of a sub-sample of 17 galaxies in the redshift range z=0.4-0.7,
where MgII lines are covered by the SDSS spectra. The measured lower-limits on
the star-formation rates of these galaxies are in the range 0.2-20 M_sun/yr.
The emission line luminosities and (O/H) metallicities from R23 measured in
this sample are similar to what is found in normal galaxies at these redshifts.
Thus, this constitutes a unique sample of intermediate redshift star-forming
galaxies where we can study the QSO absorber - galaxy connection. Strong MgII
(W>1A) as well as MgI absorption lines are detected in the QSO spectra at the
redshift of most of these galaxies. Strong FeII (W>1A) absorption lines are
also generally detected whenever the appropriate wavelength ranges are covered.
This suggests that most of these systems could be bona-fide Damped Lyman-alpha
systems. We investigate various possible relations between the MgII rest
equivalent widths and the emission line properties. We find a possible (2
sigma) correlation between the emission-line metallicity of the galaxies and
the MgII rest equivalent width of the absorbers [truncated].Comment: 15 pages, 11 figures, 5 tables. accepted for publication in MNRA
Catalytic abatement of trichloroethylene over Mo and/or W-based bronzes
[EN] In this paper we present the results of the synthesis, characterization and catalytic behaviour of Mo(W)¿Nb¿V¿O mixed metal oxides bronzes for the catalytic oxidation of trichloroethylene. The catalysts were prepared hydrothermally with different Mo/W/Nb/V/P atomic ratio and heat-treated at 500 and 700 °C. They were characterized by several techniques as N2-adsorption, X-ray diffraction, FTIR, SEM-EDS, temperature programmed desorption, temperature programmed reduction, UV¿vis, Fourier transformed infrared spectroscopy of adsorbed pyridine and 18O/16O isotope exchange. X-ray diffraction patterns (XRD) of samples heat-treated at 500 °C suggest the presence of a semi-crystalline material with a diffraction peak at ca. 2¿ = 22.2°, while XRD patterns of samples heat-treated at 700 °C show the formation of a tetragonal tungsten bronze (TTB) structure. The activity for the catalytic abatement of trichloroethylene strongly depends on the heat-treatment temperature and the catalyst composition. Thus, samples with W/(Mo + W) atomic ratios of 0.25-0.75 and heat-treated at 500 °C are the most active ones. The enhanced activity has been related to the remarkable higher surface area of the catalyst and to the catalyst composition which influences the acid characteristics as well as the reducibility and reoxidation of the catalysts. The importance of the oxygen dissociation on the catalyst surface and the diffusion of oxygen species through the catalyst are also discussed.The authors wish to thank DGICYT in Spain (Project CTQ2009-14495 and CSD2009-00050-CONSOLIDER/INGENIO 2010) and Universitat Politecnica de Valencia for the financial support. N.B.R. acknowledges Catedra Cemex Sostenibilidad (UPV) for a fellowship. M.D.S. acknowledges Universitat Politecnica de Valencia for a fellowship.Blanch Raga, N.; Soriano Rodríguez, MD.; Palomares Gimeno, AE.; Concepción Heydorn, P.; Martínez Triguero, LJ.; López Nieto, JM. (2013). Catalytic abatement of trichloroethylene over Mo and/or W-based bronzes. Applied Catalysis B: Environmental. 130-131:36-43. https://doi.org/10.1016/j.apcatb.2012.10.016S3643130-13
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