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Efficient Solvent-Free Preparation of Imines, and Their Subsequent Oxidation with <i>m</i>-CPBA to Afford Oxaziridines

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Green and Sustainable Chemistry 2019年第4期9卷 143-154页

作者： Luis álvarez-Santamaría Eusebio Juaristi Alexa Berenice Arroyo-Colín Jorge Palma.flores Fanny Araceli Cabrera-rivera Jaime Escalante Centro de Investigaciones Químicas Universidad Autónoma del Estado de Morelos Cuernavaca Morelos Mexico Departamento de Química Centro de Investigación y de Estudios Avanzados Ciudad de México México El Colegio Nacional Luis Gonzáles Obregón 23 Centro Histórico Ciudad de México México

A simple one-pot procedure for the preparation of imines from the corresponding aldehydes and amines, and their subsequent oxidation reaction with m-CPBA to produce synthetically useful oxaziridines is reported. The method is applicable to imines derived from both aliphatic and aromatic aldehydes and diverse alkyl amines. Short reaction times, essentially quantitative yields, very mild reaction conditions, and easy purification are the main features of the procedure reported herein.

关键词： Solvent-Free Reaction Imines Oxaziridines Oxidation Reaction m-CPBA

Ubiquitin-proteasome system and oxidative stress in liver transplantation

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World Journal of Gastroenterology 2018年第31期24卷 3521-3530页

作者： Norma Alva Arnau Panisello-Roselló Marta.flores Joan Roselló-Catafau Teresa Carbonell Department of Cell Biology Physiology and ImmunologyUniversity of Barcelona Experimental Pathology Department Institute of Biomedical Research of Barcelona

A major issue in organ transplantation is the development of a protocol that can preserve organs under optimal conditions. Damage to organs is commonly a consequence of flow deprivation and oxygen starvation following the restoration of blood flow and reoxygenation. This is known as ischemia-reperfusion injury(IRI): a complex multifactorial process that causes cell damage. While the oxygen deprivation due to ischemia depletes cell energy, subsequent tissue oxygenation due to reperfusion induces many cascades, from reactive oxygen species production to apoptosis initiation. Autophagy has also been identified in the pathogenesis of IRI, although such alterations and their subsequent functional significance are controversial. Moreover, proteasome activation may be a relevant pathophysiological mechanism. Different strategies have been adopted to limit IRI damage, including the supplementation of commercial preservation media with pharmacological agents or additives. In this review, we focus on novel strategies related to the ubiquitin proteasome system and oxidative stress inhibition, which have been used to minimize damage in liver transplantation.

关键词： Liver transplant Ischemia-reperfusion injury Oxidative stress Proteasome Redox regulation Ubiquitin

Cytotoxic effect of Spirulina platensis extracts on human acute leukemia Kasumi-1 and chronic myelogenous leukemia K-562 cell lines

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Asian Pacific Journal of Tropical Biomedicine 2017年第1期7卷 14-19页

作者： Flor Yohana.flores Hernandez Sanghamitra Khandual Inocencia Guadalupe Ramírez López Center for Investigation and Assistance in Technology Design for State of JaliscoC.P.45019ZapopanJaliscoMexico

Objective: To evaluate the cytotoxic effects of Spirulina platensis extracts on acute leukemia Kasumi-1 and chronic leukemia K-562 cancer cell ***: Various concentrations of Spirulina platensis extracts(0.25–50.00 mg/m L)obtained with different solvents were used to treat cell lines for 72 h. For cytotoxic effect studies, cell viability test with trypan blue solution, MTT assay and microscopic cytomorphological assessment were ***: Spirulina extract obtained with 70% ethanol showed significant cytotoxicity in K562 and Kasumi-1 cell lines. With trypan blue solution, IC_(50) values were found to be4.64 mg/m L for K-562 and 3.68 mg/m L for Kusumi-1 cell lines. Spirulina aqueous extract also showed cytotoxicity with trypan blue method, at a slightly higher dose; where IC_(50) values were 12.68 mg/m L for K-562 and 2.13 mg/m L for Kusumi-1 cell lines. The IC_(50) values were found 0.40 mg/m L for K-562 and 0.31 mg/m L for Kusumi-1 cell lines for the 70% ethanol extract according to the MTT assay. Spirulina extract obtained with water also showed cytotoxicity but the dose was a little higher where IC_(50) values were15.77 mg/m L for K-562 and 9.44 mg/m L for Kusumi-1 cell lines. The effect of cytotoxicity with ethanol extract is quite comparable with that observed for cyclophosphamide, which is a chemical used as anticancer ***: The cytotoxicity exhibited by Spirulina extract to cancer cell lines might be due to the presence of phytopigments(carotenoids, chlorophyll, phycocyanin) as well as polysaccharides that were reported previously as constituents of the extract. So crude extracts of Spirulina can be used as a source to develop anticancer drugs.

关键词： Leukemia Cytotoxicity Spirulina Carotenoids

Mechanical and natural ventilation systems in a greenhouse designed using computational fluid dynamics

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International Journal of Agricultural and Biological Engineering 2014年第1期7卷 1-16页

作者： Jorge flores-Velazquez Juan I.Montero Esteban J.Baeza Juan C.Lopez Mexican Institute of Water Technology.Paseo Cuauhnáhuac 8532 Col.ProgresoC.P.62550JiutepecMor.Mexico Institut de Recerca i Tecnologia Agroalimentàries 08348Cabrils(Barcelona)Spain IFAPA Centro La Mojonera(Junta de Andalucía) Camino San Nicolás 104745 La MojoneraAlmeríaSpain Fundación Cajamar.Estación Experimental“Las Palmerillas”Autovía del Mediterráneo Km 416 704710El EjidoAlmeríaSpain

The aim of this study was to analyse air exchange and temperature distribution in a greenhouse with combined mechanical and natural ventilation and to design more efficient mechanical ventilation *** this purpose,a computational fluid dynamics(CFD)model of the greenhouse was *** configurations were considered:Configuration 1(mechanical ventilation and closed roof ventilators),Configurations 2 and 3(mechanical ventilation and roof ventilators open 30%and 100%,respectively).After validation,the CFD model was used to improve the design of the greenhouse mechanical ventilation system in each of the three configurations *** greenhouse lengths,28 m,50 m,75 m and 100 m,were used in the *** to fan ventilation only,roof ventilation improved the climate of fan-ventilated greenhouses in terms of the air exchange rate(22%)and climate uniformity because the internal air was mixed better than with mechanical ventilation *** the greenhouse length increased,more advantages were achieved with natural ventilation compared to mechanical *** most configurations,there was a strong linear correlation between temperature gradient and greenhouse *** greenhouse whose regression line had the steepest slope was the one with closed roof *** the fan capacity produced a general reduction in temperature,but the effect was less intense for the greenhouses with open roof *** to box inlet ventilators,an enlarged continuous inlet in the wall opposite the fans increased overall system performance because it eliminated backflow recirculation zones,which are prone to produce high temperatures.

关键词： greenhouse cooling fan ventilation roof ventilators combined ventilation

Synthesis of surface controlled nickel/palladium hydride nanodendrites with high performance in benzyl alcohol oxidation

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Nano Research 2019年第6期12卷 1467-1472页

作者： Zipeng Zhao Michelle M.flores Espinosa Jihan Zhou Wang Xue Xiangfeng Duan Jianwei Miao Yu Huang Department of Materials Science and Engineering University of CaliforniaLos AngelesCA 90095USA Department of Physics and Astronomy University of CaliforniaLos AngelesCA 90095USA Department of Chemistry and Biochemistry University of CaliforniaLos AngelesCA 90095USA California Nanosystems Institute University of CaliforniaLos AngelesCA 90095USA

Benzaldehyde byproduct is an imperative intermediate in the production of fine chemicals and *** selectivity to benzaldehyde is therefore critical in alcohol oxidation reactions at the industrial ***,we report a simple but innovative method for the synthesis of palladium hydride and nickel palladium hydride nanodendrites with controllable morphology,high stability,and excellent catalytic *** synthesized dendrites can maintain the palladium hydride phase even after their use in the chosen catalytic ***,the high surface area morphology and unique interaction between nickel-rich surface and palladium hydride (β-phase) of these nanodendrites are translated in an enhanced catalytic activity for benzyl alcohol oxidation *** Ni/PdH0.43 nanodendrites demonstrated a high selectivity towards benzaldehyde of about 92.0% with a conversion rate of 95.4%,showing higher catalytic selectivity than their PdH0.43 counterparts and commercial Pd/*** present study opens the door for further exploration of metal/metal-hydride nanostructures as next-generation catalytic materials.

关键词： benzyl alcohol selectivity benzaldehyde palladium hydride oxidation nanodendrites

Role of vitamin B_(12) on methylmalonyl-CoA mutase activity

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2012年第6期13卷 423-437页

作者： Tóshiko TAKAHASHI-IIGUEZ Enrique GARCíA-HERNANDEZ Roberto ARREGUíN-ESPINOSA María Elena.flores Department of Molecular Biology and Biotechnology Institute of Biomedical ResearchNational Autonomous University of MexicoD.F.04510Mexico Department of Chemistry of Biomacromolecules Institute of ChemistryNational Autonomous University of MexicoD.F.04510Mexico

Vitamin B 12 is an organometallic compound with important metabolic derivatives that act as cofactors of certain enzymes,which have been grouped into three subfamilies depending on their *** them,methylmalonyl-CoA mutase (MCM) has been extensively *** enzyme catalyzes the reversible isomerization of L-methylmalonyl-CoA to succinyl-CoA using adenosylcobalamin (AdoCbl) as a cofactor participating in the generation of radicals that allow isomerization of the *** crystal structure of MCM determined in Propionibacterium freudenreichii *** has helped to elucidate the role of this cofactor AdoCbl in the reaction to specify the mechanism by which radicals are generated from the coenzyme and to clarify the interactions between the enzyme,coenzyme,and *** existence of human methylmalonic acidemia (MMA) due to the presence of mutations in MCM shows the importance of its role in *** recent crystallization of the human MCM has shown that despite being similar to the bacterial protein,there are significant differences in the structural organization of the two *** studies have identified the involvement of an accessory protein called MMAA,which interacts with MCM to prevent MCM's inactivation or acts as a chaperone to promote regeneration of inactivated *** interdisciplinary studies using this protein as a model in different organisms have helped to elucidate the mechanism of action of this isomerase,the impact of mutations at a functional level and their repercussion in the development and progression of MMA in *** is still necessary to study the mechanisms involved in more detail using new methods.

关键词： Vitamin B 12 Methylmalonyl-CoA mutase (MCM) MMAA MeaB Methylmalonic academia (MMA) Protectase Reactivase

基于多种深度学习算法的田间玉米籽粒检测与计数

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智慧农业（中英文） 2022年第4期4卷 49-60页

作者：刘晓航张昭刘嘉滢张漫李寒 Paulo flores 韩雄哲中国农业大学智慧农业系统集成研究教育部重点实验室北京100083 中国农业大学农业农村部农业信息获取技术重点实验室北京100083 北达科他州州立大学农业与生物工程系美国法戈58102 韩国江原大学生物系统工程系韩国春川24341 韩国江原大学韩国春川24341

为快速准确获取玉米收获过程中遗失籽粒数信息,进行收割损失调节等管理,对比评估了单阶段和两阶段主流目标检测网络对田间玉米籽粒计数的性能。首先,利用RGB相机获取包含不同背景和不同光照的图像数据,并进一步生成数据集;其次,构建籽... 详细信息

为快速准确获取玉米收获过程中遗失籽粒数信息,进行收割损失调节等管理,对比评估了单阶段和两阶段主流目标检测网络对田间玉米籽粒计数的性能。首先,利用RGB相机获取包含不同背景和不同光照的图像数据,并进一步生成数据集;其次,构建籽粒识别的不同目标检测网络,包括Mask RCNN、EfficientDet-D5、YOLOv5-L、YOLOX-L,并利用所采集的420幅有效图像对构建的四种网络进行训练、验证、测试,图像数分别为200、40和180幅;最后,依据测试集图像的识别结果进行籽粒计数性能评价。试验结果表明,YOLOv5-L网络对测试集图像检测的平均精度为78.3%,模型尺寸仅为89.3 MB;籽粒计数的检测正确率、漏检率和F1值分别为90.7%、9.3%和91.1%,处理速度为55.55 f/s,识别与计数性能均优于Mask R-CNN、EfficientDet-D5和YOLOX-L网络,并对具有不同地表遮挡程度和籽粒聚集状态的图像具有较强的鲁棒性。深度学习目标检测网络YOLOv5-L可实现实际作业中玉米收获损失籽粒的实时监测,精度高、适用性强。

关键词：收获损失田间玉米籽粒深度学习籽粒计数 YOLOv5-L YOLOX-L Mask R-CNN EfficientDet-D5

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

Influence of Data Clouds Fusion From 3D RealTime Vision System on Robotic Group Dead Reckoning in Unknown Terrain

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IEEE/CAA Journal of Automatica Sinica 2020年第2期7卷 368-385页

作者： Mykhailo Ivanov Oleg Sergyienko Vera Tyrsa Lars Lindner Wendy flores-Fuentes Julio Cesar Rodriguez-Quinonez Wilmar Hernandez Paolo Mercorelli Universidad Autónoma de Baja California MexicaliB.C.21100Mexico Universidad de Las Américas Quito 170125Equador Leuphana University of Lueneburg Lüneburg 21335Germany

This paper proposes the solution of tasks set required for autonomous robotic group behavior optimization during the mission on a distributed area in a cluttered hazardous *** navigation scheme uses the benefits of the original real-time technical vision system(TVS)based on a dynamic triangulation *** method uses TVS output data with fuzzy logic rules processing for resolution *** on previous researches,the dynamic communication network model is modified to implement the propagation of information with a feedback method for more stable data exchange inside the robotic *** to the comparative analysis of approximation methods,in this paper authors are proposing to use two-steps post-processing path planning aiming to get a smooth and energy-saving *** article provides a wide range of studies and computational experiment results for different scenarios for evaluation of common cloud point influence on robotic motion planning.

关键词： Data transfer group behavior machine vision navigation robotic group(RG) vision system