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Preparation and Characterization of Flexible, Transparent and Thermally Stable Aromatic Co-polyamides

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Chinese Journal of Polymer Science 2019年第2期37卷 136-141页

作者： José Antonio Tec-Sánchez Andrés Iván Oliva Arias Manuel Aguilar-Vega Juan Valerio Cauich-Rodríguez José Luis Santiago-García Unidad de Materiales Centro de Investigación Científica de Yucatán A. C. centro de investigación y de estudios avanzados del ipn Unidad Mérida Departamento de Física Aplicada

Two aromatic co-polyamides were synthesized combining two diacid monomers containing bulky pendant groups, 5-(9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboximido)isophthalic acid(deAIA) and 5-tert-butylisophthalic acid(TERT), with 4,4′-(hexafluoroisopropylidene)dianiline(HFA) or 2,3,5,6-tetramethyl-1,4-phenylenediamine(Durene) by direct polycondensation. The structures of the obtained aromatic co-polyamides were confirmed by FTIR, Raman and 1 H-nMR. The co-copolyamide films, DHTH and DDTD, exhibited rms-roughness values between 0.94 and 1.60 nm, respectively. Moreover, they presented good thermal stability up to300 °C. young's moduli of the co-polyamide films were between 4.1 and 4.3 GPa. X-ray diffraction results showed that the co-polyamide films were amorphous due to the incorporation of both bulky pendant groups, tert-butyl and dibenzobarrelene. The combination of bulky pendant groups provided intrinsically transparent co-polyamide films with a transmittance higher than 88% in the range of 400-780 *** to these outstanding film and optical properties, they are suggested to be flexible substrates in applications for solar cell and other portable electronic devices.

关键词： Co-polyamides Flexible films Transmittance Thermal stability Polycondensation

road to stemness in hepatocellular carcinoma

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World Journal of Gastroenterology 2017年第37期23卷 6750-6776页

作者： Teresita nJ Flores-Téllez Saúl Villa-Trevino Carolina Pina-Vázquez departam ento de Biología Celular Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional(CINVESTAV-IPN) Av.IPN No.2508 Col

Carcinogenic process has been proposed to relay on the capacity to induce local tissue damage and proliferative repair. Liver has a great regeneration capacity and currently, most studies point towards the dominant role of hepatocytes in regeneration at all levels of liver damage. The most frequent liver cancer is hepatocellular carcinoma(HCC). Historical findings originally led to the idea that the cell of origin of HCC might be a progenitor cell. However, current linage tracing studies put the progenitor hypothesis of HCC origin into question. In agreement with their dominant role in liver regeneration, mature hepatocytes are emerging as the cell of origin of HCC, although, the specific hepatocyte subpopulation of origin is yet to be determined. The relationship between the cancer cell of origin(CCO) and cancer-propagating cells, known as hepatic cancer stem cell(HCSC) is unknown. It has been challenging to identify the definitive phenotypic marker of HCSC, probably due to the existence of different cancer stem cells(CSC) subpopulations with different functions within HCC. There is a dynamic interconversion among different CSCs, and between CSC and non-CSCs. Because of that, CSC-state is currently defined as a description of a highly adaptable and dynamic intrinsic property of tumor cells, instead of a static subpopulation of a tumor. Altered conditions could trigger the gain of stemness, some of them include: EMT-MET, epigenetics, microenvironment and selective stimulus such as chemotherapy. This CSC heterogeneity and dynamism makes them out reach from therapeutic protocols directed to a single target. A further avenue of research in this line will be to uncover mechanisms that trigger this interconversion of cell populations within tumors and target it.

关键词： Cancer stem cell Liver progenitor cell Liver stem progenitor cell Stemness Plasticity Cancer cell of origin Cancer stem cells subpopulations

Microstructural evaluation and nanohardness of an AlCoCuCrFeniTi high-entropy alloy

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International Journal of Minerals,Metallurgy and Materials 2019年第5期26卷 634-641页

作者： C.D.Gómez-Esparza R.Peréz-Bustamante J.M.Alvarado-Orozco J.Mu?oz-Salda?a R.Martínez-Sánchez J.M.Olivares-Ramírez A.Duarte-Moller centro de investigación en Materiales avanzados (CIMAV) Laboratorio Nacional de Nanotecnología COnACyT-Corporación Mexicana de investigación en Materiales S.A.de C.V.(COMIMSA) centro de Ingeniería y desarrollo Industrial Querétaro Campus centro de investigación y de estudios avanzados del ipn Unidad Querétaro Universidad Tecnológica de San Juan del Río Escuela de Ingeniería Civil Industrialy Mecánica Universidad De La Salle Bajío

An AlCoCuCrFeniTi high-entropy alloy(HEA) was prepared by mechanical alloying and sintering to study the effect of Ti addition to the widely studied AlCoCuCrFeni system. The structural and microstructural characteristics were investigated by X-ray diffraction(XRD), scanning electron microscopy(SEM), and transmission electron microscopy(TEM). The formation of four micrometric phases was detected: a Cu-rich phase with a face-centered cubic(fcc) structure, a body-centered cubic(bcc) solid solution with Cu-rich plate-like precipitates(fcc), an ordered bcc phase, and a tetragonal structure. The XRD patterns corroborate the presence of a mixture of bcc-, fcc-, and tetragonal-structured phases. The Vickers hardness of the alloy under study was more than twice that of the AlCoCuCrFeni alloy. nanoindentation tests were performed to evaluate the mechanical response of the individual phases to elucidate the relationship between chemical composition, crystal structure, and mechanical performance of the multiphase microstructure of the AlCoCuCrFeniTi HEA.

关键词： high-entropy alloys mechanical alloying microstructure nanoindentation

A versatile microfluidic device for multiple ex vivo/ in vitro tissue assays unrestrained from tissue topography

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Microsystems & nanoengineering 2020年第1期6卷 806-819页

作者： Jose M.de Hoyos-Vega Alan M.Gonzalez-Suarez Jose L.Garcia-Cordero Unidad Monterrey Centro de Investigacion y de Estudios Avanzados del IPNVia del conocimiento 201Parque PIITApodacaNL 66628Mexico

Precision-cut tissue slices are an important in vitro system to study organ function because they preserve most of the native cellular microenvironments of organs,including complex intercellular ***,during sample manipulation or slicing,some of the natural surface topology and structure of these tissues is lost or ***,we introduce a microfluidic platform to perform multiple assays on the surface of a tissue section,unhindered by surface *** device consists of a valve on one side and eight open microchannels located on the opposite side,with the tissue section sandwiched between these two *** the valve is actuated,eight independent microfluidic channels are formed over a tissue *** strategy prevents cross-contamination when performing assays and enables *** irregular tissues such as an aorta,we conducted multiple in vitro and ex vivo assays on tissue sections,including short-term culturing,a drug toxicity assay,a fluorescence immunohistochemistry staining assay,and an immune cell assay,in which we observed the interaction of neutrophils with lipopolysaccharide(LPS)-stimulated *** microfluidic platform can be employed in other disciplines,such as tissue physiology and pathophysiology,morphogenesis,drug toxicity and efficiency,metabolism studies,and diagnostics,enabling the conduction of several assays with a single biopsy sample.

关键词： metabolism topography versatile

nano to micro size transition of hydroxyapatite in porcine bone during heat treatment with low heating rates

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Progress in natural Science:Materials International 2020年第4期30卷 494-501页

作者： Angélica M.Castillo-Paz Sandra M.Londo?o-Restrepo Liliana Tirado-Mejía M.A.Mondragón Mario E.Rodríguez-García Grupo de Optoelectrónica Instituto Interdisciplinario de las Ciencias Universidad del Quindío centro de investigación y de estudios avanzados del ipn departamento de nanotecnología Centro de Física Aplicada y Tecnología Avanzada Universidad Nacional Autónoma de México Campus Juriquilla

This work focuses on the changes of raw hydroxyapatite obtained from porcine bones during heat treatment with heating rates of 2.5 and 5.0 °C/min between 600 °C and 1100 °C. High-Resolution transmission electron microscopy(HR-TEM) images showed that raw hydroxyapatite was formed by high-ordered nanometric platelet crystals with a length of around 18 nm and width around 7 nm. High-Resolution scanning electron microscopy(HR-SEM) images evidenced the coalescence phenomena during heating giving. It was found that the growth of the crystals and the transition from nano to a micro-size occurred at around 700 °C. And the changes in the full width at half maximum(FWHM) for the characteristic(002) plane of the X-ray diffraction patterns and the FWHM of the characteristic Raman band at 960 cm-1 for ν1 PO43-exhibited the transition from nano to a micro size, that was confirmed by HR-SEM images and the thermogravimetric(TG) analysis. The porosity of the BIOHAp changes from intra nanometric to intercrystalline.

关键词： Bone composition Hydroxyapatite nanoparticles Mineral composition Porosity formation Raman analysis

Tale of two kinases:Protein kinase A and Ca^(2+)/calmodulin-dependent protein kinase Ⅱ in pre-diabetic cardiomyopathy

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World Journal of Diabetes 2021年第10期12卷 1704-1718页

作者： Pamela Gaitán-González Rommel Sánchez-Hernández José-Antonio Arias-Montaño Angélica Rueda department of Biochemistry Centro de Investigación y de Estudios Avanzados del Instituto Politécnico NacionalCiudad de México 07360Mexico department of Physiology Biophysics and NeurosciencesCentro de Investigación y de Estudios Avanzados del Instituto Politécnico NacionalCiudad de México 07360Mexico

Metabolic syndrome is a pre-diabetic state characterized by several biochemical and physiological alterations,including insulin resistance,visceral fat accumulation,and dyslipidemias,which increase the risk for developing cardiovascular *** syndrome is associated with augmented sympathetic tone,which could account for the etiology of pre-diabetic *** review summarizes the current knowledge of the pathophysiological consequences of enhanced and sustainedβ-adrenergic response in pre-diabetes,focusing on cardiac dysfunction reported in diet-induced experimental models of pre-diabetic *** research reviewed indicates that both protein kinase A and Ca^(2+)/calmodulin-dependent protein kinase Ⅱ play important roles in functional responses mediated byβ1-adrenoceptors;therefore,alterations in the expression or function of these kinases can be *** review also outlines recent information on the role of protein kinase A and Ca^(2+)/calmodulin-dependent protein kinase Ⅱ in abnormal Ca^(2+)handling by cardiomyocytes from diet-induced models of pre-diabetic cardiomyopathy.

关键词： Ca^(2+)/calmodulin-dependent protein kinase II Protein kinase A Metabolic syndrome Pre-diabetes Pre-diabetic cardiomyopathy β-Adrenoceptors

A survey of static and dynamic potential games

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Science China Mathematics 2016年第11期59卷 2075-2102页

作者： GOnZALEZ-SAnCHEZ David HERnAndeZ-LERMA Onesimo Consejo nacional de Ciencia y Tecnología Universidad de Sonora Hermosillo 83000 Mexico Mathematics department Centro de Investigación y de Estudios Avanzados del Instituto Politecnico National Mexico City 07000 Mexico

Potential games are noncooperative games for which there exist auxiliary functions, called potentials,such that the maximizers of the potential are also nash equilibria of the corresponding game. Some properties of nash equilibria, such as existence or stability, can be derived from the potential, whenever it exists. We survey different classes of potential games in the static and dynamic cases, with a finite number of players, as well as in population games where a continuum of players is allowed. Likewise, theoretical concepts and applications are discussed by means of illustrative examples.

关键词： noncooperative games potential games nash equilibrium dynamic games Markov games differential games population games

Effects of Silicon nanoparticles on the Transient Liquid Phase Bonding of 304 Stainless Steel

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Journal of Materials Science & Technology 2014年第3期30卷 259-262页

作者： H.M.Hdz-García A.I.Martinez R.Mu?oz-Arroyo J.L.Acevedo-Dávila F.García-Vázquez F.A.Reyes-Valdes Corporación Mexicana de investigación en Materiales S.A.de C.V. Ciencia y Tecnología No.790 Fracc.Saltillo 400 Saltillo Coah.CP.25290 Mexico centro de investigación y de estudios avanzados del ipn Carr.Mty-Saltillo km.13 Ramos Arizpe Coah.CP.25900 Mexico

Transient liquid phase （TLP） bonding of 304 stainless steel with nickel based filler metal, Bni-9, was performed to study the influence of silicon nanoparticles （nPs） on the mechanical and structural properties of the bonding area. It was found that silicon nPs act as a melting point depressant in the brazing process; the formation of silicon TLP induces the dissolution of elements of the metal filler and promotes a uniform distribution in the bonding area. Silicon nPs induce the development of smaller eutectic structures in the melting zone; it has been related to microhardness measurements, which are lower when the silicon nPs are used in the brazing process.

关键词： Brazing nanoparticles Silicon Stainless steel

Current and novel approaches in the pharmacological treatment of hepatocellular carcinoma

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World Journal of Gastroenterology 2023年第17期29卷 2571-2599页

作者： Fernanda Villarruel-Melquiades María Eugenia Mendoza-Garrido Claudia M García-Cuellar yesennia Sánchez-Pérez Julio Isael Pérez-Carreón Javier Camacho departamento de Farmacología Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional(CINVESTAV-IPN)Mexico City 07360Mexico departamento de Fisiología Biofísica y NeurocienciasCentro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional(CINVESTAVIPN)Mexico City 07360Mexico Subdirección de investigación Básica Instituto Nacional de Cancerología(INCan)Mexico City 14080Mexico Instituto nacional de Medicina Genómica Instituto Nacional de Medicina Genómica(INMEGEN)Mexico City 14610Mexico

Hepatocellular carcinoma(HCC)is one of the most lethal malignant tumours *** mortality-to-incidence ratio is up to 91.6%in many countries,representing the third leading cause of cancer-related *** drugs,including the multikinase inhibitors sorafenib and lenvatinib,are first-line drugs used in HCC ***,these therapies are ineffective in most cases due to late diagnosis and the development of tumour ***,novel pharmacological alternatives are urgently *** instance,immune checkpoint inhibitors have provided new approaches targeting cells of the immune ***,monoclonal antibodies against programmed cell death-1 have shown benefits in HCC *** addition,drug combinations,including first-line treatment and immunotherapy,as well as drug repurposing,are promising novel therapeutic ***,we review the current and novel pharmacological approaches to fight *** studies,as well as approved and ongoing clinical trials for liver cancer treatment,are *** pharmacological opportunities analysed here should lead to significant improvement in HCC therapy.

关键词： Liver cancer Systemic therapy Immunotherapy Drug repurposing Drug combinations Hepatocellular carcinoma