Crystal structure and second harmonic generation in Bi₂TeO₅: An X-N study from synchrotron and neutron diffraction data

Ló,pez, C.A.,Bâ,ati, E.,Ferná,ndez-Dí,az, M.T.,Saouma, F.O.,Jang, J.I.,Alonso, J.A. Academic Press 2019 Journal of solid state chemistry Vol.276 No.-

<P><B>Abstract</B></P> <P>Bi<SUB>2</SUB>TeO<SUB>5</SUB> has been obtained in polycrystalline form via solid state reaction and structurally characterized from both synchrotron and neutron powder diffraction data, enabling the precise determination of the atomic positions. The crystal structure is defined in the acentric <I>Amb</I>2 space group, containing three crystallographically unequivalent Bi atoms. The position of the stereochemically active electron lone pairs of both Bi<SUP>3+</SUP> and Te<SUP>4+</SUP> ions is inferred to be opposite to the strongly covalent BiO and TeO chemical bonds; the global electron polarization arises from the non-compensated Bi<SUP>3+</SUP> lone electron pairs. Additionally, from difference Fourier maps between synchrotron and neutron diffraction data (X-N technique) it was possible to observe experimental evidence of the lone electron pair for Bi<SUP>3+</SUP>. Nonlinear optical measurements display highly active second harmonic generation response, comparable to that of reference AgGaSe<SUB>2</SUB>.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The crystal structure is defined in the non-centrosymmetric <I>Amb</I>2 space group. </LI> <LI> Fourier maps between synchrotron and neutron diffraction data (X-N technique). </LI> <LI> Experimental evidence of Bi<SUP>3+</SUP>lone electron pair from X-N study. </LI> <LI> Nonlinear optical measurements display highly active SHG response. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

First report of Gymnosporangium clavipes Cooke & Peck affecting Crataegus mexicana var. Chapeado and C. gracilior in Mexico

D. Alvarado-Rosales,E. H. Nieto-López,D. Téliz-Ortiz,V. Ayala-Escobar,R. Nieto-Angel,H. V. Silva-Rojas,S. G. Leyva-Mir,A. Jiménez-Nieto,C. Méndez-Inocencio 한국식물병리학회 2015 식물병연구 Vol.21 No.3

The tejocote (Crataegus spp.) is a tree considered to be native to Mexico. The aim of this study was to identify the causal agent of tejocote rust in the State of Puebla. Tejocote fruits were sampled in 2012 and 2013. The fungus was studied morphologically using light and scanning electron microscopy and molecularly using phylogenetic analysis of 18S and 28S rDNA genes. The fungus was identified as Gymnosporangium clavipes on tejocote fruits. To our knowledge, this is the first confirmed report of Gymnosporangium clavipes Cooke & Peck affecting Crataegus mexicana var. Chapeado and C. gracilior in Puebla Mexico.

Molecular Engineering of Zinc Phthalocyanines with Phosphinic Acid Anchoring Groups

Ló,pez‐,Duarte, Ismael,Wang, Mingkui,Humphry‐,Baker, Robin,Ince, Mine,Martí,nez‐,Dí,az, M. Victoria,Nazeeruddin, Mohammad K.,Torres, Tomá,s,Grä,tzel, Mich WILEY‐VCH Verlag 2012 Angewandte Chemie Vol.124 No.8

<P><B>Zwei Zinkphthalocyanin‐Photosensibilisatoren</B> mit verschiedenen Phosphinsäure‐Ankergruppen (siehe Schema) wurden synthetisiert. Solarzellen mit diesen Verbindungen verfügen über eine Photostromdichte von (7.6±0.2) mA cm<SUP>−2</SUP> bei geschlossenem Stromkreis, eine Spannung von (559±30) mV bei offenem Stromkreis und einen Füllfaktor von 0.76±0.03; dies entspricht einem Gesamtwirkungsgrad von 3.24 % unter 1 sun.</P>

Comparison of physicochemical properties of bio and commercial hydroxyapatite

A.L. Giraldo-Betancur,D.G. Espinosa-Arbelaez,A. del Real-López,B.M. Millan-Malo,E.M. Rivera-Muñoz,E. Gutierrez-Cortez,P. Pineda-Gomez,S. Jimenez-Sandoval,M.E. Rodriguez-García 한국물리학회 2013 Current Applied Physics Vol.13 No.7

This article reports a physicochemical comparison of synthetic and biological Hydroxyapatite (HAp). Eight samples were separated into two groups: bio and commercial hydroxyapatite (bio-HAp and commercial-HAp). The bio-HAp group containing defat, alkaline, and calcined samples taken from bovine bone were obtained by using three different treatments, in order to establish their effect on the final product quality. The commercial-HAp group, from different sources: NIST, sigma, apafill G, coralina, and biograft, were analyzed and compared with the bio-HAp results. Thermogravimetric analysis (TG) was used in order to establish thermal degradation of the samples; structural behavior was then analyzed by X-Ray Diffraction (XRD) to found the crystalline phases, as well as the crystalline quality. Fourier Transform Infrared Spectroscopy (FTIR) was performed in order to identify the corresponding HAp functional groups within the samples. The surface morphology was analyzed by Scanning Electron Microscopy (SEM) and the elemental composition was established by using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). It was found that the calcination process obtains HAp with comparable quality to the commercial samples. A crystallinity greater than 62% after the alkaline process was found. Additionally, the surface of the alkaline sample presents a transition behavior between dense and porous morphology.

The fibrogenic process and the unleashing of acute-on-chronic liver failure

Guillermo Nahúm López-Sánchez,Mayra Dóminguez-Pérez,Misael Uribe,Natalia Nuño-Lámbarri 대한간학회 2020 Clinical and Molecular Hepatology(대한간학회지) Vol.26 No.1

Acute-on-chronic liver failure (ACLF) is a life-threatening condition characterized by a rapid deterioration of previously well-compensated chronic liver diseases. One of the main obstacles in ACLF is the lack of knowledge of the pathogenesis and specific broad-spectrum treatments. An excessive systemic inflammatory response has been proposed to explain the pathogenesis of ACLF; this hypothesis involves stellate cells, which are implicated in many liver homeostatic functions that include vitamin A storage, regulation of sinusoidal blood flow, local inflammation, maintenance of the hepatocyte phenotype and extracellular matrix remodeling. However, when there is damage to the liver, these cells are the main target of the inflammatory stimulus, as a result, the secretion of the extracellular matrix is altered. Activated hepatic stellate cells raise the survival of neutrophils by the stimulation of granulocytes colonies and macrophages, which exacerbates liver inflammation and promotes damage to hepatocytes. Elevation of pathogen-associated molecular patterns is related to liver damage by different pathophysiological mechanisms of decompensation, showing ballooning degeneration and cell death with a predominance of cholestatic infection. Moreover, patients with ACLF present a marked elevation of C-reactive protein together with an elevation of the leukocyte count. Chronic liver disease is a complex pathological state with a heterogeneous pathophysiology in which genetic factors of the host and external triggers interact and culminate in hepatic insufficiency. The better understanding of such interactions should lead to a better comprehension of the disease and to the discovery of new treatment targets that will make acute decompensations preventable and even decrease mortality.

Neural Mechanisms in Eating Behaviors: A Pilot fMRI Study of Emotional Processing

Rosa M. Molina-Ruiz,T. García-Saiz,Jeffrey C.L. Looi,E. Via Virgili,M. Rincón Zamorano,Laura de Anta Tejado,Helena Trebbau López,Jose Luis Carrasco Perera,Marina Díaz-Marsá 대한신경정신의학회 2020 PSYCHIATRY INVESTIGATION Vol.17 No.3

Objective Emotional processing dysfunction evident in eating disorders (ED) such as anorexia nervosa (AN) and bulimia nervosa (BN), is considered relevant to the development and maintenance of these disorders. The purpose of the current functional magnetic resonance imaging (fMRI) study was to pilot a comparison of the activity of the fronto-limbic and fronto-striatal brain areas during an emotion processing task in persons with ED. Methods 24 women patients with ED were scanned, while showing emotionally stimulating (pleasant, unpleasant) and neutral images from the International Affective Picture System (IAPS). Results During the pleasant condition, significant differences in Dorsolateral Prefrontal Cortex (DLPFC) activations were found with AN participants presenting greater activation compared to BN and ED comorbid groups (EDc) and healthy controls also showing greater activation of this brain area compared to BN and EDc. Left putamen was less activated in EDc compared to both controls (C) and AN. During the unpleasant condition, AN participants showed hyperactivation of the Orbito-Frontal Cortex (OFC) when compared to EDc. Conclusion This study highlights the potential functional relevance of brain areas that have been associated with self-control. These findings should help advance understanding the neural substrate of ED, though they should be considered as preliminary and be cautiously interpreted.

The Role of Mitochondrial Dynamic Dysfunction in Age-Associated Type 2 Diabetes

Vezza Teresa,Díaz-Pozo Pedro,Canet Francisco,de Marañón Aranzazu M.,Abad-Jiménez Zaida,García-Gargallo Celia,Roldan Ildefonso,Solá Eva,Bañuls Celia,López-Domènech Sandra,Rocha Milagros,Víctor Víctor M 대한남성과학회 2022 The World Journal of Men's Health Vol.40 No.3

Mitochondrial dynamics, such as fusion and fission, play a critical role in maintaining cellular metabolic homeostasis. The molecular mechanisms underlying these processes include fusion proteins (Mitofusin 1 [MFN1], Mitofusin 2 [MFN2], and optic atrophy 1 [OPA1]) and fission mediators (mitochondrial fission 1 [FIS1] and dynamin-related protein 1 [DRP1]), which interact with each other to ensure mitochondrial quality control. Interestingly, defects in these proteins can lead to the loss of mitochondrial DNA (mtDNA) integrity, impairment of mitochondrial function, a severe alteration of mitochondrial morphology, and eventually cell death. Emerging evidence has revealed a causal relationship between dysregulation of mitochondria dynamics and age-associated type 2 diabetes, a metabolic disease whose rates have reached an alarming epidemic-like level with the majority of cases (59%) recorded in men aged 65 and over. In this sense, fragmentation of mitochondrial networks is often associated with defects in cellular energy production and increased apoptosis, leading, in turn, to excessive reactive oxygen species release, mitochondrial dysfunction, and metabolic alterations, which can ultimately contribute to β-cell dysfunction and insulin resistance. The present review discusses the processes of mitochondrial fusion and fission and their dysfunction in type 2 diabetes, with special attention given to the therapeutic potential of targeting mitochondrial dynamics in this complex metabolic disorder.

Precipitation Hardening and Corrosion Behavior of Friction Stir Welded A6005-TiB2 Nanocomposite

N. Abu‑warda,M. D. López,B. González,E. Otero,M. D. Escalera‑Rodríguez,S. Cruz,P. Rey 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.8

Precipitation hardening and corrosion behavior of a friction stir welding (FSW) based on the aluminum alloy A6005 reinforcedwith TiB2nanoparticles have been studied. Mechanical alloying (MA) and hot extrusion techniques have beenemployed as processing route followed by FSW. Samples characterization has been performed by DSC and TEM, and precipitationstrengthening of the bulk samples and the FSW joint has been evaluated by micro-hardness tests after T6 thermaltreatment. TEM characterization revealed the presence of Mg–Si hardening phases, mainly of β′ phase, and dispersoids ofα-Al(FeMnCr)Si into the aluminum matrix. The results revealed that samples subjected to MA had less susceptibility toT6 thermal treatment and that the presence of nano-TiB2 reinforcement accelerates aging time. In addition, electrochemicaltests based on polarization tests have been performed in 3.5% NaCl solution to assess the effect of FSW process on corrosionbehavior. The FSW joint had worse corrosion behavior since the passive Al2O3film was not generated on the weldzone. SEM–EDS analysis revealed that pits nucleated mainly in sites with a higher presence of Fe contaminant which actscathodically with respect to the aluminum matrix, producing galvanic corrosion.

Multi-site, multi-year monitoring of the oscillating Algol-type eclipsing binary CT Herculis

Lampens, P.,Strigachev, A.,Kim, S.-L.,Rodrí,guez, E.,Ló,pez-Gonzá,lez, M. J.,Vidal-Saí,nz, J.,Mkrtichian, D.,Koo, J.-R.,Kang, Y. B.,Van Cauteren, P.,Wils, P.,Kraicheva, Z.,Dimi EDP Sciences 2011 Astronomy and astrophysics Vol.534 No.2

<P>We present the results of a multi-site photometric campaign carried out in 2004–2008 for the Algol-type eclipsing binary system CT Her, the primary component of which displays δ Scuti-type oscillations. Our data consist of differential light curves collected in the filters B and V, which were analysed using the method of Wilson-Devinney (PHOEBE). After identifying an adequate binary model and removing the best-fit light-curve solution, we performed a Fourier analysis of the residual B and V light curves to investigate the pulsational behaviour. We confirm the presence of rapid pulsations with a main period of 27.2 min. Up to eight significant frequencies with semi-amplitudes in the range 3 to 1 mmag were detected, all of which lie in the frequency range 43.5–53.5 d<SUP>−1</SUP>. This result is independent of the choice of the primary’s effective temperature (8200 or 8700 K) since the light-curve models of the binary are very similar in both cases. This is yet another case of a complex frequency spectrum observed for an accreting δ Scuti-type star (after Y Cam). In addition, we demonstrate that the amplitudes of several pulsation frequencies provide evidence of variability on timescales as short as 1–2 years, perhaps even less. Moreover, our analysis takes into account some recently acquired spectra, from which we obtained the corresponding radial velocities for the years 2007–2009. Investigation of the O–C diagram shows that further monitoring of the epochs of eclipse minima of CT Her will cast new light on the evolution of its orbital period.</P>

Analysis of virulence traits of Staphylococcus aureus isolated from bovine mastitis in semi-intensive and family dairy farms

Jaquelina J. Guzmán-Rodríguez,Ma. Fabiola León-Galván,José E. Barboza-Corona,Mauricio Valencia-Posadas,Pedro D. Loeza-Lara,Mónica Sánchez-Ceja,Alejandra Ochoa-Zarzosa,Joel E. López-Meza,Abner J. Gutié 대한수의학회 2020 Journal of Veterinary Science Vol.21 No.5

Background: Staphylococcus aureus is one of the main microorganisms that causes bovine mastitis, and its well-known virulence characteristics and interactions with the environment are used to aid the design of more efficient therapies. Objectives: To determine whether the virulence traits, such as antibiotic resistance and biofilm-forming and internalization abilities, of S. aureus isolated from bovine mastitis are related to dairy production system types. Methods: The study was performed in the Mexican states of Guanajuato and Michoacan. Semi-intensive dairy farms (SIDFs) and family dairy farms (FDFs) (454 and 363 cows, respectively) were included. The 194 milk samples from mastitis affected quarters were collected and 92 strains of S. aureus were isolated and identified by biochemical and molecular tests. Antibiotic resistance, biofilm and internalization assays were performed on 30 randomly selected isolated strains to determine virulence traits, and these strains were equally allocated to the 2 dairy production systems. Results: All 30 selected strains displayed a high degree of resistance (50%–91.7%) to the antibiotics tested, but no significant difference was found between SIDF and FDF isolates. S. aureus strains from SIDFs had an average biofilm forming capacity of up to 36% (18.9%–53.1%), while S. aureus strains from FDFs registered an average of up to 53% (31.5%–77.8%) (p > 0.05). Internalization assays revealed a higher frequency of internalization capacity for strains isolated from FDFs (33.3%) than for those isolated from SIDFs (6.7%) (p > 0.05). fnbpA gen was detected in 46.6% of FDF strains and 33.3% of SIDF strains, and this difference was significant (p < 0.05). Conclusions: Our findings show that the virulence traits of S. aureus isolates analyzed in this study, depend significantly on several factors, such as phenotype, genotype, and environmental conditions, which are significantly related to dairy production system type and daily management practices.