439 research outputs found
Boosting the chances to improve stroke treatment
Background and Purpose—There is a lack of agreement regarding measuring the effects of stroke treatment in clinical
trials, which often relies on the dichotomized value of 1 outcome scale. Alternative analyses consist mainly of 2
strategies: use all the information from an ordinal scale and combine information from several outcome scales in a
single estimate.
Methods—We reanalyzed 3 outcome scales that assessed patient recovery (modified Rankin Scale, National Institutes of
Health Stroke Scale, and Barthel Index). With data collected from the 1652 patients in the Citicoline pooling data
analysis, we used 2 standard techniques of exploratory multivariate analysis to analyze the distances among ranks and
to isolate the common and the unique information provided by each of the 3 scales.
Results—The different scale values correspond to gradually different patient status, confirming that information is lost
when a scale is collapsed to just 2 values, whether recovered or not. The scales shared 90.7% (95% CI, 84.5–96.9) of
their information, with no individual scale contributing unique information.
Conclusions—Salient stroke outcome information is lost when an ordinal scale is collapsed into fewer categories. In
contrast, the full scales provide a comprehensive patient outcome estimate. Furthermore, in the context of stroke clinical
trials, those scales are highly correlated, providing the rationale to pool them into a single estimate. These insights may
be used to optimize the analysis of stroke trials to increase study power to detect efficacious interventions.Postprint (published version
Indicadores de la modernización mexicana
Se sostiene aquí la hipótesis de que el proyecto neoliberal mexicano perjudica a las grandes mayorías y favorece fundamentalmente a los ya privilegiados, al menos a corto y mediano plazos. La obra presenta el marco internacional en que se está produciendo la modernización nacional; informa sobre algunos indicadores de la modernización económica a nivel macro; reflexiona sobre los procesos de reforma educativa que el modelo exige, promueve e impone; habla del papel de los medios de comunicación en el proceso y aterriza las consecuencias de la modernización en el caso de los obreros e indígenas.ITESO, A.C.Centro de Reflexión y Acción SocialCentro de Reflexión Teológic
ANALYSIS OF THE UV SOLAR IRRADIANCE FOR THE SYNTHESIS OF PRE-VITAMIN D3 ON THE SKIN, IN ROSARIO, ARGENTINA
In the last years, the study of vitamin D has raised due to the increase in the incidence of people who have deficient levels of this vitamin. Few foods contain vitamin D3 naturally, the main source of obtaining the ultraviolet (UV)solar radiation, which triggers the synthesis on the skin’s surface. In this study, the effective UV solar irradiance for the synthesis of pre-vitamin D3 was determined in Rosario city, Argentina, using three methods: a) ProportionalityCoefficient, b) Herman’s equation and c) TUV model. The values were compared in clear sky conditions at solar noon.The Solar Exposure Times (TES) that reach the minimum doses of solar UV radiation for the synthesis of pre-vitamin D3 and erythema were calculated, along the period june 2019 - may 2020. The variation of the TES to accumulate the minimum dose of pre-vitamin D3 and erythema with a photoexposure of 25 % of the body (face, neck and arms) is discusse
Insights onto the magnetic coupling at hexaferrite-based hard/soft bilayer systems
IBERTRIVA 2019 X Iberian Conference on Tribology – IBERTRIB, XI Iberian Vacuum Conference - RIVA, Seville, Spain,June 26-28Magnets are used in a variety of applications, such as generators, magnetic recording media,
components in RF and microwave devices. However, many of these magnets contain s rare
earths, critical elements whose extraction is environmentally harmful and that present price
volatility risks. Their replacement by cheaper and more environmentally friendly materials is
therefore sought.
In our case, we have focused on magnetically hard strontium hexaferrite (SrFe 12O19, SFO) as
the base for alternative permanent magnets (Figure 1a). The atomic arrangement of this ferrite
results in a high magnetocrystalline anisotropy and a coercive field, however, its magnetization
is moderate (1). It is well known that the coupling between a magnetically hard and soft material
improved magnetization while avoiding a high cost in coercitivity loss (2). However, results have
been disappointing so far as structural and geometrical limitations make it extremely challenging
to fabricate. In this work, we aim at further understanding the magnetic coupling at hard -soft
interfaces involving ferrites, for which we have deposited soft iron and cobalt metals on top of
SrFe12O19 thin films with controlled easy-axis of magnetization.
SFO thin films have been obtained by RF magnetron sputtering at 260W followed by a
subsequent annealing in air of 850ºC. Their structure and composition was characterized by
Raman spectroscospy (Figure 1b), Mössbauer spectroscopy, X-ray photoemission
spectroscopy and low-energy electron microscopy (LEEM). We have grown the magnetically
soft layer by molecular-beam epitaxy and we have analyzed the resulting bilayer system
through photoemission electron microscopy, LEEM and vibrating-sample magnetometry.
References
[1] R.C. Pullar, Hexagonal ferrites: a review of the synthesis, properties and applications of hexaferrite ceramics, Progress in Materials Science 57 (2012), pp 1191¿1334.
[2] Eric E. Fullerton, J. S. Jiang, M. Grimsditch, C. H. Sowers, and S. D. Bader, Exchange-spring behavior in epitaxial hard/soft magnetic bilayers, Phys. Rev. B 58 (1998) 1219
Comparative analysis of the chemical quality of fishmeal produced on the Northwest coast of Mexico
Objective: To evaluate the physico-chemical quality of fishmeal produced by four companies in different states of the Republic (Baja California Sur, Jalisco and Sinaloa).
Design/methodology/approach: The analyzed fishmeals were from six batches, sardine meal from California pilchard and Pacific thread herring (S. sagax and O. libertate), and skipjack tuna and (K. pelamis) processed by different Mexican companies. Proximal chemical analysis was carried out at the Centro de Investigaciones Biológicas del Noroeste (CIBNOR).
Results: The fishmeal’s quality parameters analyzed in this study showed similar values to those reported in the literature. The variations observed in their proximate chemical composition allow them to be classified according to the results of the analyses.
Limitations on study/implications: Considering that four of the six flours were produced from the same raw material, S. sagax, the high variability in their physico-chemical quality parameters indicates a lack of standardization in both production methods and quality controls among the producing companies.
Findings/conclusions: K. pelamis by-products can produce meals of equal or better physico-chemical quality than those produced from S. sagax. The development of official regulations establishing quality standards to fishmeal production at national level is desirable for competitiveness.Objective: To evaluate the physico-chemical quality of fishmeal produced by four companies in different states of the Republic (Baja California Sur, Jalisco, and Sinaloa).
Design/methodology/approach: The analyzed fishmeals were from six batches, sardine meal from California pilchard and Pacific thread herring (S. sagax and O. libertate), and skipjack tuna and (K. pelamis) processed by different Mexican companies. Proximal chemical analysis was carried out at the Centro de Investigaciones Biológicas del Noroeste (CIBNOR).
Results: The fishmeal’s quality parameters analyzed in this study showed similar values to those reported in the literature. The variations observed in their proximate chemical composition allow them to be classified according to the results of the analyses.
Limitations on study/implications: Considering that four of the six flours were produced from the same raw material, S. sagax, the high variability in their physico-chemical quality parameters indicates a lack of standardization in both production methods and quality controls among the producing companies.
Findings/conclusions: K. pelamis by-products can produce meals of equal or better physico-chemical quality than those produced from S. sagax. The development of official regulations establishing quality standards to fishmeal production at national level is desirable for competitiveness
Identification of Nontuberculous Mycobacteria in Drinking Water in Cali, Colombia
Nontuberculous mycobacteria (NTM) are ubiquitous microorganisms naturally resistant to antibiotics and disinfectants that can colonize drinking water supply systems. Information regarding the spread of NTM in specifically South America and Colombia is limited. We aimed to identify and characterize NTM present in tap water samples from Cali, Colombia. Drinking water samples and faucet biofilm swabs were collected in 18 places, including the city’s three main water treatment plants (WTPs). Filter-trapped material and eluates (0.45 μm) from swab washes were plated in 7H11 agar plates. Suspected colonies were evaluated microscopically, and NTM species were identified based on the rpoB gene. Antibiotic susceptibility testing was also performed. Fifty percent (9/18) of sampling points were positive for NTM (including two WTPs), from which 16 different isolates were identified: Mycobacterium mucogenicum (8/16), M. phocaicum (3/16), M. chelonae (2/16), M. mageritense (2/16), and M. fortuitum (1/16), all rapidly growing mycobacteria. A susceptibility profile was obtained from 68.75% (11/16) of the isolates. M. chelonae was the most resistant species. All NTM isolated are potentially responsible for human diseases; our findings might provide a baseline for exploring NTM transmission dynamics and clinical characterization, as well as potential associations between NTM species found in drinking water and isolates from patients
Substituent and ring effects on enthalpies of formation: 2-methyl- and 2-ethylbenzimidazoles versus benzene-and imidazole-derivatives
The enthalpies of combustion, heat capacities, enthalpies of sublimation and enthalpies of formation of 2-methylbenzimidazole (2MeBIM) and 2-ethylbenzimidazole (2EtBIM) are reported and the results compared with those of benzimidazole itself (BIM). Theoretical estimates of the enthalpies of formation were obtained through the use of atom equivalent schemes. The necessary energies were obtained in single-point calculations at the B3LYP/6-311+G(d,p) on B3LYP/6-31G* optimized geometries. The comparison of experimental and calculated values of benzenes, imidazoles and benzimidazoles bearing H (unsubstituted), methyl and ethyl groups shows remarkable homogeneity. The energetic group contribution transferability is not followed, but either using it or adding an empirical interaction term, it is possible to generate an enormous collection of reasonably accurate data for different substituted heterocycles (pyrazole-derivatives, pyridine-derivatives, etc.) from the large amount of values available for substituted benzenes and those of the parent (pyrazole, pyridine) heterocycles.We acknowledge the financial support of the DGI/MCyT (project nos. BQU-2003-00976, 01251 and 05827). This work has been partially supported by the DGI project no. BQU-2003-00894. A generous allocation of computational time at the CCC of the Universidad Auto´noma de Madrid is also gratefully acknowledged. Thanks are also due to Instituto de Cooperac¸a˜o Cientı´fica e Tecnolo´gica Internacional (ICCTI), Lisbon, Portugal, and Consejo Superior de Investigaciones Cientı´ficas (CSIC), Madrid, Spain, for a joint research project ICCTI/CSIC. MLPFA thanks Fundac¸a˜o para a Cieˆncia e Tecnologia (FCT), Lisbon, Portugal, for the award of a postdoctoral fellowship (PRAXIS XXI/BPD/16319/98)
and MT thanks MECD/SEEU (AP 2002-0603), Spain, for financial support
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