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Evaluating physical changes of iron oxide nanoparticles due to surface modification with oleic acid

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Chinese Physics B 2020年第10期29卷 186-194页

作者： S Rosales N casillas A Topete O Cervantes G González j A Paz M E Cano Centro Universitario de Ciencias Exactas e Ingenienas Universidad de GuadalajaraBlvd.Marcelino Garcia Burragan 1421C.P.44430GuadalajaraJaliscoMexico Centro Universitario de la Cienegu Universidad de GuadalajaraAv.Universidad 1115C.P.47820OcotlanJaliscoMexico Centro Universitario de Ciencias de In Salud Universidad de Guadalajara.Sierra Mojada 950C.P.44340GuadalajaraJaliscoMexico

The physical characterization of a colloidal system of superficially modified magnetic nanoparticles (MNPs) is presented. The system consists of oleic acid-coated iron oxide nanoparticles (OAMNP) suspended in water. A structural analysis is carried out by using standard physical techniques to determine the diameter and shape of the MNPs and also the width of the coating shell. The colloidal stability and the polydispersity index of this ferrofluid are determined by using Zeta potential measurements. Additionally, the magnetic characterization is conducted by obtaining the DC magnetization loops, and the blocking temperatures are determined according to the ZFC–FC protocol. Finally, the values of power absorption density P of the ferrofluid are estimated by using a magneto-calorimetric procedure in a wide range of magnetic field amplitude H and frequency f. The experimental results exhibit spherical-like shape of OAMNP with (20 ± 4) nm in diameter. Due to the use of coating process, the parameters of the magnetization loops and the blocking temperatures are significantly modified. Hence, while the uncoated MNPs show a blocking state of the magnetization, the OAMNP are superparamagnetic above room temperature (300 K). Furthermore, the reached dependence P versus f and P versus H of the ferrofluid with coated MNPs are clearly fitted to linear and quadratic correlations, respectively, showing their accordance with the linear response theory.

关键词： nanoparticles ferrofluid magnetic hyperthermia functionalization

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脉冲神经网络的发展（英文）

宁波大学学报(理工版) 2025年第02期 59-70页

作者： TALANOV Max FEDOROVA Alina KIPELKIN Ivan VALLVERDU jordi EROKHIN victor 梅西纳大学工程系塞尔维亚人工智能研发研究所喀山联邦大学信息技术与智能系统学院罗巴切夫斯基大学 StoLab 加泰罗尼亚高等研究院哲学系意大利国家研究委员会(IMEM-CNR)电子与磁性材料研究所

脉冲神经网络(SNNs)代表了一种生物启发计算框架,它将神经科学和人工智能联系在一起,在时序数据处理、能效和实时决策方面具有独特优势.探讨了SNN技术的演化过程,强调了其与高级学习机制的集成,如尖峰时间依赖可塑性(STDP)和与深度学习... 详细信息

脉冲神经网络(SNNs)代表了一种生物启发计算框架,它将神经科学和人工智能联系在一起,在时序数据处理、能效和实时决策方面具有独特优势.探讨了SNN技术的演化过程,强调了其与高级学习机制的集成,如尖峰时间依赖可塑性(STDP)和与深度学习架构的融合.利用忆阻器作为纳米级突触设备,显著提高了能效、适应性和可扩展性,解决了神经形态计算中的关键问题.通过相图和非线性动力学分析,验证了系统在不同工作负载下的稳定性和鲁棒性.这些进步使SNNs成为机器人、物联网和自适应低功耗人工智能系统等应用领域的一项变革性技术,为神经形态硬件和混合学习范式的未来创新铺平了道路.

关键词：脉冲神经网络忆阻器相图高能效人工智能神经形态计算

AT1 receptor downregulation:A mechanism for improving glucose homeostasis

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World journal of Diabetes 2023年第3期14卷 170-178页

作者： Diana L Lopez Oscar E casillas Hiram j jaramillo Tatiana Romero-Garcia j.Gustavo Vazquez-jimenez Department of Internal Medicine General Hospital of MexicaliMexicali 21000Baja CaliforniaMexico Faculty of Medicine Autonomous University of Baja CaliforniaMexicali 21000Baja CaliforniaMexico Faculty of Sports Autonomous University of Baja CaliforniaMexicali 21289Baja CaliforniaMexico

There is a pathophysiological correlation between arterial hypertension and diabetes mellitus, established since the pre-diabetic state in the entity known as insulin resistance. It is known that high concentrations of angiotensin-Ⅱ enable chronic activation of the AT1 receptor, promoting sustained vasoconstriction and the consequent development of high blood pressure. Furthermore, the chronic activation of the AT1 receptor has been associated with the development of insulin resistance. From a molecular outlook, the AT1 receptor signaling pathway can activate the jNK kinase. Once activated, this kinase can block the insulin signaling pathway, favoring the resistance to this hormone. In accordance with the previously mentioned mechanisms, the negative regulation of the AT1receptor could have beneficial effects in treating metabolic syndrome and type 2diabetes mellitus. This review explains the clinical correlation of the metabolic response that diabetic patients present when receiving negatively regulatory drugs of the AT1 receptor.

关键词： Type 2 diabetes mellitus High blood pressure Insulin receptor Insulin signaling pathway AT1 receptor Angiotensin II signaling pathway

Stereodynamics of O（^3P）＋H2 at Scattering Energies of 0.5, 0.75, and 1.0 eV

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Chinese journal of Chemical Physics 2010年第2期23卷 149-154,I0001页

作者： victor Wei-keh Wu 国立高雄应用科技大学、化学材料工程系高雄80782 胜利者基础研究实验室、比勒费尔德D-33602 德国

Quasiclassical trajectory calculation of the title reaction O（^3P）＋H2→OH＋H at three different scattering energies of 0.5, 0.75, and 1.0 eV on the lowest electronic potential energy surface 1^3A＂ has been done. Distribution P（θr） of polar angles between the relative velocityk of the reactant and rotational angular momentum vector j＇ of the product, distribution P（φr） of the azimuthal as well as dihedral angles correlating k-k＇-j＇, 3-dimensional distri-bution, and polarization-dependent differential cross sections （PDDCSs）dependent upon the scattering angle of the product molecule OH between the relative velocity k of the reactant and k＇ of the product at different scattering energies of 0.5, 0.75, and 1.0 eV are presented and discussed.

关键词： Quasiclassical trajectory calculation Stereodynamics Alignment Rotational angular momentum Polarization-dependent differential cross section O+H2 reaction

Finite Element Analysis of Residual Stress and Distortion in an Eccentric Ring Induced by Quenching

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材料热处理学报 2004年第05B期25卷 746-751页

作者： LI M. victor Portland State University PO Box 751-ME Portland OR 97207-075J USA

The residual stresses and distortion induced by quenching in an eccentric ring were investigated in this study with finite element method. The ring was made of AISI 52100 steel. A fully coupled 3D temperature-displacement analysis was performed to simulate heat transfer, phase transformations, and mechanical stresses and strains during the heating and subsequent quenching processes. Commercial FEA package ABAQUS/Standard 6.4 was used for the analyses along with user subroutines developed by the authors to model the thermal and mechanical constitutive behavior. The simulation results show that transformation plasticity plays an important role on the residual stress distribution.

关键词：残余应力有限元分析变形偏心环相变塑性

Analysis of per-and polyfluoroalkyl substances in Houston Ship Channel and Galveston Bay following a large-scale industrial fire using ion-mobility-spectrometry-mass spectrometry

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journal of Environmental Sciences 2022年第5期34卷 350-362页

作者： Alan Valdiviezo Noor AAly Yu-Syuan Luo Alexandra Cordova Gaston casillas MaKayla Foster Erin SBaker Ivan Rusyn Interdisciplinary Faculty of Toxicology Texas A&M UniversityCollege StationTX 77843USA Department of Veterinary Integrative Biosciences Texas A&M UniversityCollege StationTX 77843USA Department of Environmental and Occupational Health Texas A&M UniversityCollege StationTX 77843USA Department of Chemistry North Carolina State UniversityRaleighNC 27695USA

Per-and polyfluoroalkyl substances(PFAS)are persistent organic pollutants of concern be-cause of their ubiquitous presence in surface and ground water;analytical methods that can be used for rapid comprehensive exposure assessment and fingerprinting of PFAS are *** the fires at the Intercontinental Terminals Company(ITC)in Deer Park,TX in 2019,large quantities of PFAS-containing firefighting foams were *** release of these substances into the Houston Ship Channel/Galveston Bay(HSC/GB)prompted con-cerns over the extent and level of PFAS contamination.A targeted liquid chromatography-tandem mass spectrometry(LC-MS/MS)-based study of temporal and spatial patterns of PFAS associated with this incident revealed presence of 7 species;their levels gradually de-creased over a 6-month *** the targeted LC-MS/MS analysis was focused on about 30 PFAS molecules,it may have missed other PFAS compounds present in firefighting ***,we utilized untargeted LC-ion mobility spectrometry-mass spectrome-try(LC-IMS-MS)-based analytical approach for a more comprehensive characterization of PFAS in these water *** analyzed 31 samples from 9 sites in the HSC/GB that were collected over 5 months after the *** data showed that additional 19 PFAS were detected in surface water of HSC/GB,most of them decreased gradually after the *** features detected by LC-MS/MS correlated well in abundance with LC-IMS-MS data;however,LC-IMS-MS identified a number of additional PFAS,many known to be compo-nents of firefighting *** findings therefore illustrate that untargeted LC-IMS-MS improved our understanding of PFAS presence in complex environmental samples.

关键词： Emergency Environmental disaster PFAS

Increasing effect of metamorphism on rock properties

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International journal of Mining Science and Technology 2015年第2期25卷 205-211页

作者： Akinbinu victor Abioye Department of Mining Engineering Federal University of Technology

This work studied the effect of increasing degree of metamorphism on the properties of *** properties investigated are the physical,mechanical and dynamic *** are important inputs in the design of many mining and civil engineering techniques such as in tunnelling,slope stability and dynamic activities associated with seismicity and *** work compared the degree of metamorphism examined through petrographic studies of the Transvaal Sequence in South Africa with the properties of the *** study shows that as the effect metamorphism increases,the state of stress,compaction of grains,cementation and the brittleness of the rocks *** addition,increase in the metamorphic effect increases the value of the rock *** degree of metamorphism of an outcrop is the key factor influencing its property *** the metamorphism effect of an outcrop may act as a guide to its engineering properties.

关键词： Geology of rock Rock property Brittleness Fragmentation and metamorphism

Changes in insomnia severity with advanced PAP therapy in patients with posttraumatic stress symptoms and comorbid sleep apnea:A retrospective,nonrandomized controlled study

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Military Medical Research 2019年第4期6卷 308-319页

作者： Barry j.Krakow Natalia D.McIver jessica j.Obando victor A.Ulibarri Sleep&Human Health Institute 6739 Academy Rd NE Ste380AlbuquerqueNM 87109USA Maimonides Sleep Arts&Sciences 6739 Academy Rd NE Ste380AlbuquerqueNM 87109USA Los Alamos Medical Center 3917 W RdLos AlamosNM 87544USA Institution:Mozaik Solutions Solana BeachCA 92075USA

Background:Sleep disorders frequently occur in posttraumatic stress disorder(PTSD)*** insomnia is a common feature of and criteria for the diagnosis of *** sleep disorder,obstructive sleep apnea(OSA),also occurs frequently in PTSD,and emerging research indicates OSA fuels chronic *** research has investigated the impact of OSA treatment on insomnia outcomes(Insomnia Severity Index,ISI)in trauma ***:OSA patients with moderately severe posttraumatic stress symptoms were studied in a retrospective chart ***-six patients who failed CPAP therapy due to expiratory pressure intolerance or complex sleep apnea or both underwent manual titration with advanced PAP modes[autobilevel(ABPAP);adaptive servo-ventilation(ASV)],which were subsequently *** use measured by objective data downloads divided the sample into three groups:compliant regular users(C-RU):n=68;subthreshold users(SC-RU):n=12;and noncompliant users(NC-MU):n=*** average follow-up was 11.89±12.22 *** and posttreatment ISI scores were analyzed to assess residual insomnia symptoms as well as cure ***:The C-RU group showed significant improvements in insomnia with very large effects compared to those in the NC-MU reference group(P=0.019).Insomnia severity significantly decreased in all three groups with large effects(C-RU,P=0.001;SC-RU,P=0.027;NC-MU,P=0.007).Hours of weekly PAP use and insomnia severity were inversely correlated(P=0.001,r=–0.321).However,residual insomnia symptoms based on established ISI cut-offs were quite common,even among the C-RU *** hoc analysis showed that several categories of sedating medications reported at baseline(hypnotics,anti-epileptic,opiates)as well as actual use of any sedating medication(prescription or nonprescription)were associated with smaller insomnia improvements than those in patients not using any sedating ***:In a retrospective,nonrandomized analysis of a selec

关键词： Insomnia Obstructive sleep apnea Complex insomnia CBT-I Posttraumatic stress symptoms CPAP Auto bi-level Adaptive servo-ventilation

Pronuclear formation by ICSI using chemically activated ovine oocytes and zona pellucida bound sperm

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journal of Animal Science and Biotechnology 2017年第2期8卷 370-377页

作者： j.E.Hernández-Pichardo Y.Ducolomb S.Romo M.E.Kjelland R.Fierro F.casillas M.Betancourt División de Ciencias Biológicas y de la Salud Departamento de Producción Agrícola y AnimalUniversidad Autónoma Metropolitana-XochimilcoCiudad de MexicoMexico Division de Ciencias Biologicas y de la Salud Departamento de Ciencias de la SaludUniversidad Autónoma Metropolitana-IztapalapaSan Rafael Atlixco 186CP 09340 Ciudad de MexicoMexico Departamento de Ciencias Pecuarias Facultad de EstudiosSuperiores CuautitlanUNAMCiudad de MexicoEstado de MexicoMexico Conservation Genetics&BiotechLLCValley CityNDUSA Division de Ciencias Biologicas y de la Salud Departamento de Biologia de la ReproduccionUniversidad Autonoma Metropolitana-lztapalapaCiudad de MexicoMexico Doctorado en Biologia Experimental Universidad Autonoma Metropolitana-lztapalapaCiudad de MexicoMexico

Background： In order to improve ICSI, appropiate sperm selection and oocyte activation is necessary. The objective of the present study was to determine the efficiency of fertilization using ICSI with chemically activated ovine oocytes and sperm selected by swim up（SU） or swim up ＋ zona pellucida（SU ＋ ZP） ***： Experiment 1, 4–20 replicates with total 821 in vitro matured oocytes were chemically activated with ethanol, calcium ionophore or ionomycin, to determine oocyte activation（precense of one PN）. Treatments showed similar results（54, 47, 42 %, respectively） but statistically differents（P 0.05）.Conclusions： Chemical activation induces higher ovine oocyte activation than mechanical activation. Ethanol slightly displays higher oocyte activation than calcium ionophore and ionomicine. Sperm selection with SU ＋ ZP increased AR/A and AR/D rates in comparison with SU in fresh and frozen-thawed sperm. According to this, in terms of fertilization rates, chemical activation after ICSI increased oocyte PN formation compared to mechanical activation. Also, fresh sperm treated with SU and SU ＋ ZP were significantly different than frozen-thawed sperm,but between sperm treatments no significant differences were obtained.

关键词： Ethanol ICSI Oocyte activation Ovine Pronucleus Zona pellucida