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Phosphine/Benzocyclone-based neutral nickel Catalysts for Ethylene Polymerization and Copolymerization with Polar Monomers

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ch.nese Journal of Polymer Science 2024年第2期42卷 202-212,I0007页

作者： Fei Wang li Pan Vladislav A.Tuskaev Svetlana ch.Gagieva Yue-Sheng li Tianjin Key Lab of Composite&Functional Materials School of Material Science and EngineeringTianjin UniversityTianjin300072China Department of chemistry Lomonosov Moscow State UniversityRussian Federation InstitutionLeninskie Gory 1Moscow119991Russian Federation A n nesmeyanov Institute of Organoelement Compounds Russian Academy of SciencesVavilova st.28Moscow119991Russian Federation

The efficient copolymerization of olefin with polar monomers using nickel-based catalysts presents a longstanding challenge. In this contribution, three phosphine-benzocyclone ligands and corresponding neutral nickel catalysts(ni1: Ar = Ph;ni2: Ar = 2-(C_(6)H_(5))C_(6)H_(4);ni3: Ar = 2-[2',6'-(Me O)_(2)-C_(6)H3]C_(6)H_(4)) were prepared and applied for the ethylene polymerization and copolymerization with polar monomers without any cocatalyst. The bulky substituent groups in complexes ni2 and ni3 contributed to high catalytic activities(up to 7.24×10^(6) and 9.04×10^(6)g·mol ni^(-1)·h^(-1), respectively), and produced high-molecular-weight polyethylene(Mw up to 545.7 k Da). Complex ni3 exhibited high activities for ethylene polymerization at the level of 10^(6) g·mol ni^(-1)·h^(-1) across a wide range from 30 ℃ to 120 ℃, exhibiting excellent high temperature tolerance. These nickel complexes were also effectively employed in the copolymerization of ethylene with methyl acrylate, ethyl acrylate, butyl acrylate and lauryl acrylate, producing copolymers with high molecular weights(Mw up to 80.5 k Da) and high polar monomer incorporation(up to 8.2 mol%). Microstructure analyses revealed that the introduction of large sterically hindered substituents facilitated the incorporation of polar functional units into the polymer backbone. This study demonstrates the potential of these nickel-based catalysts for efficient copolymerization of olefin with polar monomers.

关键词： neutral nickel catalyst Ethylene polymerization Copolymerization Polar acrylate monomers

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Geochemistry and mineral chemistry of the armoor granitoids,eastern dharwar craton: implications for the redox conditions and tectono-magmatic environment

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Acta Geochimica 2024年第1期43卷 110-133页

作者： A.Ajay Kumar ch.ashok Department of Geology Osmania UniversityHyderabad 500007India CSIR-national Geophysical Research Institute UppalHyderabad 500007India

The mineralogical and geochemical characteristics of the K-rich granites from the Armoor granitic rocks in the northeastern portion of the Eastern Dharwar Craton(EDC) are *** order to understand its physicochemical conditions,the petrogenesis of the granitoid was explained from biotite chemistry and geochemical *** of mineral chemistry expose that compositionally,K-feldspar and plagioclase in Armoor granite rocks range from An0,Ab_(3-5.9),Or_(94-96.9) and An_(5-29,-Ab71.9-94.9),Or_(0-1.5),*** mineral chemistry of biotite crystals exhibits composition that varies from primary to re-equilibrated primary *** biotites from the Armoor granites generally exhibit an I-type trend,with calc-alkaline parental magma in a subduction *** chemistry of granites displays magnetite(oxidized)series nature,which has oxygen fugacity(fO_(2))=-15.1 to-16.7(log_(10) bar),under high oxidizing *** and pressure estimates for the crystallization of Armoor granites based on biotite composition are T=612-716 ℃ and 1.0-0.4 kbar,***,these rocks are metaluminous to slightly peraluminous and magnesian,with calc-alkaline potassiumrich *** the ch.ndrite normalized REE diagram,the granites have positive europium anomalies;rich Sr/Y,(Dy/Yb)_(n) ratios and reduced Mg#,Rb/Sr,Rb,Sr indicate that the melting of earlier rocks,crystal accumulation and residual garnet source formed at high *** examined granites show that they are produced from the melting of crustal ***,the extensive analyses of the described Armoor granite suggest that they were produced by crust sources and developed under oxidizing conditions in subduction setting.

关键词： Armoor granites Oxygen fugacity Crystal accumulation Remelting Subduction

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Bile acids,gut microbiota,and therapeutic insights in hepatocellular carcinoma

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Cancer Biology & Medicine 2024年第2期21卷 144-162页

作者： Yang Song Harry ch Lau Xiang Zhang Jun Yu Institute of Digestive Disease and Department of Medicine and Therapeutics State Key Laboratory of Digestive DiseaseLi Ka Shing Institute of Health SciencesCUHK Shenzhen Research InstituteThe Chinese University of Hong KongHong KongChina Department of Gastroenterology Zhongshan Hospital Xiamen UniversityXiamen 361004China

Hepatocellular carcinoma(HCC)is a prevalent and aggressive liver *** interplay between bile acids(BAs)and the gut microbiota has emerged as a critical factor in HCC development and *** normal conditions,BA metabolism is tightly regulated through a bidirectional interplay between gut microorganisms and *** gut microbiota plays a critical role in BA metabolism,and BAs are endogenous signaling molecules that help maintain liver and intestinal *** note,dysbiotic ch.nges in the gut microbiota during pathogenesis and cancer development can disrupt BA homeostasis,thereby leading to liver inflammation and fibrosis,and ultimately contributing to HCC ***,understanding the intricate interplay between BAs and the gut microbiota is crucial for elucidating the mech.nisms underlying *** this review,we comprehensively explore the roles and functions of BA metabolism,with a focus on the interactions between BAs and gut microorganisms in ***,therapeutic strategies targeting BA metabolism and the gut microbiota are discussed,including the use of BA agonists/antagonists,probiotic/prebiotic and dietary interventions,fecal microbiota transplantation,and engineered *** summary,understanding the complex BA-microbiota crosstalk can provide valuable insights into HCC development and facilitate the development of innovative therapeutic approaches for liver malignancy.

关键词： Bile acid gut microbiota hepatocellular carcinoma therapeutics microbiota modulation

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Microbial electricity-driven anaerobic phenol degradation in bioelectrochemical systems

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Environmental Science and Ecotechnology 2024年第1期17卷 40-47页

作者： Shixiang Dai Falk Harnisch Micjel chávez Morejòn nina Sophie Keller Benjamin Korth Carsten Vogt Department of Environmental Microbiology Helmholtz Centre for Environmental Research GmbH-UFZLeipzigGermany Department of Isotope Biogeochemistry Helmholtz Centre for Environmental Research GmbH-UFZLeipzigGermany

Microbial electrochemical technologies have been extensively employed for phenol ***,previous research has yielded inconsistent results,leaving uncertainties regarding the feasibility of phenol degradation under strictly anaerobic conditions using anodes as sole terminal electron *** this study,we employed high-performance liquid chromatography and gas chromatography-mass spectrometry to investigate the anaerobic phenol degradation *** findings provide robust evidence for the purely anaerobic degradation of phenol,as we identified benzoic acid,4-hydroxybenzoic acid,glutaric acid,and other metabolites of this ***,no typical intermediates of the aerobic phenol degradation pathway were ***-chamber reactors(t0.4 V ***)exhibited a phenol removal rate of 3.5±0.2 mg L^(-1) d^(-1),while two-chamber reactors showed 3.6±0.1 and 2.6±0.9 mg L^(-1) d^(-1) at anode potentials of t0.4 and t 0.2 V,*** results also suggest that the reactor configuration certainly influenced the microbial community,presumably leading to different ratios of phenol consumers and microorganisms feeding on degradation products.

关键词： Microbial electroremediation Geobacter Extracellular electron transfer Anaerobic phenol degradation Microbial syntrophy

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Boron-containing compounds as labels,drugs,and theranostic agents for diabetes and its complications

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World Journal of Diabetes 2024年第6期15卷 1060-1069页

作者： Marvin A Soriano-Ursúa R Ivan Cordova-chávez Eunice D Farfan-García George Kabalka Department of Physiology Escuela Superior de MedicinaInstituto Politécnico NacionalCiudad de México 11340Mexico Department of Physiology Instituto Politécnico NacionalMexico City 11340Mexico Department of Biochemistry Instituto Politécnico NacionalMexico City 11340Mexico Department of chemistry The University of TennesseeKnoxvilleTN 37996United States

Diabetes is a disease with a high global *** strategies have failed to limit the advancement and impact of the *** early diagnosis and treatment will require the development of new *** this sense,boroncontaining compounds have been reported as agents with the ability to reduce glycemia and *** have also been used for labeling and measuring carbohydrates and other molecules linked to the initial stages of diabetes and its *** addition,certain boron compounds bind to molecules related to diabetes development and their biological activity in the regulation of elevated ***,it should be noted that some boron compounds appear to exert beneficial effects on diabetes complications such.as accelerating wound healing while ameliorating pain in diabetic patients.

关键词： Boron Carbohydrates Metabolism Diabetes Boronodipyrromethene

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Highly divergent sympatric lineages of Leptotila verreauxi(Aves:Columbidae)suggest a secondary contact area in the Isthmus of Tehuantepec,Mexico

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Avian Research 2024年第1期15卷 12-21页

作者： Orlando J.Espinosa-chávez Adolfo G.navarro-Sigüenza Hernando Rodríguez-Correa Luis A.Sánchez-González Museo de Zoología“Alfonso L.Herrera” Depto.de Biología EvolutivaFacultad de CienciasUniversidad Nacional Autonoma de MexicoApdo.Postal 70-399CP 04510Ciudad de MexicoMexico Posgrado en Ciencias Biologicas Unidad de PosgradoEdificio D1◦PisoCircuito de PosgradosCiudad UniversitariaUniversidad Nacional Autonoma de MexicoCoyoacanCP 04510CDMXMexico Escuela nacional de Estudios Superiores Unidad Morelia Universidad Nacional Autonoma de Mexico.Antigua Carretera a Patzcuaro No.8701 Col.Ex Hacienda de San Jose de la HuertaC.P.58190MoreliaMichoacanMexico

Due to a complex geological and biotic history,the Isthmus of Tehuantepec(IT),has been long recognized as a driver for the evolutionary divergence of numerous lowland and highland *** distributed in the lowlands of the American continent,the White-Tipped Dove(Leptotila verreauxi)is a polytypic species with 13 recognized *** of these have been recorded in Mexico,and the distribution of three abuts at the IT,suggesting a contact *** estimate phylogenetic patterns,divergence times and genetic differentiation,we examined two mt DnA(nD2 and COI)and one n DnA(β-fibint 7)*** also used correlative ecological niche models(EnM)to assess whether ecological differences across the IT may have acted as a biogeographical *** estimated paleodistributions during the Middle Holocene,Last Glacial Maximum and Last Interglacial,to evaluate the influence of climate ch.nges on the distribution and demographic *** results showed genetically distinct lineages that diverged approximately 2.5 million years *** and ecological factors may have played a dual role in promoting differentiation,but also in the formation of a secondary contact zone in the southern *** ecological niche comparisons indicated that the ecological niche of sympatric lineages at the IT are not identical,suggesting niches divergence;in addition,environmental niche models across the region indicated no abrupt biogeographic barriers,but the presence of regions with low *** results suggest that genetic differentiation originated by a vicariant event probably related to environmental factors,favored the evolution of different ecological ***,the absence of a biogeographic barrier but the presence of less suitable areas in the contact regions,suggest that secondary contact zones may be also maintained by climatic factors for the eastern group,but also by biotic interactions for the western group.

关键词： Biogeographical boundary Humid and dry forests Isthmus of Tehuantepec Phylogeography Secondary contact

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Solid-liquid extraction for yttrium recovery using porous polymeric resin(XAD-7) functionalized with D_(2)EHPA

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Journal of Rare Earths 2024年第9期42卷 1764-1773,I0005页

作者： P.A.Martínez-Montoya R.G.Sanchez-Alvarado D.Y.Medina-Velazquez M.L.Carrera-Jota P.Garnica-chávez A.de J.Morales-Ramirez Higher School of chemical Engineering and Extractive Industries ESIQIEIPNDepartment of Metallurgical EngineeringUPALM S/NCol.LindavistaGustavo A.Madero Cd.de MéxicoC.P07738Mexico Metropolitan Autonomous University Department of MaterialsBasic Sciences and EngineeringAv.San Pablo No.180Col.Reynosa TamaulipasCd.de MéxicoC.P02200Mexico Center for Research.and Technological Innovation CIITECIPNCda.de CECATIs/nSanta CatarinaAzcapotzalcoC.P02250CDMXMexico

The recovery of yttrium is proposed by applying a solid-liquid extraction process using di-2-ethyl hexylphosphoric acid(D2EHPA) as extracting *** extracting agents were supported on a macro porous polymeric resin XAD-7(solid phase).Yttrium ions extraction and discharge tests were performed,firstly from a synthetic aqueous solution of 100 mg/L Y(liquid phase) at 25℃ with *** effects of pH of aqueous solutions bearing yttrium,volume fraction of extracting agents and the solid/liquid(S/L)ratio on the yttrium recovery were *** most favorable conditions for yttrium ions extraction are;20 vol% D_(2)EHPA functionalized resin,pH=1.5 and an S/L ratio of 10 mg/mL The discharge of yttrium ions was done under the same conditions of extraction stage,using a 2 mol/L [H_(2)SO_(4)] as stripping *** to 80% yttrium is extracted,while 75% yttrium is recovered in the striping *** all experiments,the reaction equilibrium is reached after 20 min,and the kinetics for the extraction stage was determined as a second-order ***,experiments were carried out to discharge the yttriumloaded resins,and it has been determined that the best pH value to strip the Y ions is *** tests of extraction and discharge for yttrium ions show that the functionalized resin can work at least five cycles without decreasing its ***,the proposed process was tested in a real solution with Y ions fro m a waste fluorescent la mp powder leached in H_(2)SO_(4),demonstrating the ability to effectively recover yttrium,separating it from various metals from the studied residue.

关键词： Yttrium recovery Rare earth solid-liquid extraction XAD-7 resin Fluorescent lamps recycling Solid-liquid kinetics extraction

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Commentary on“Desialylated Platelets Maintain Immune Quiescence through Regulating Kupffer Cells”

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Research 2024年第3期6卷 621-623页

作者： ch.n li Craig n.Morrell Aab Cardiovascular Research Institute University of Rochester School of Medicine and DentistryRochesterNYUSA Department of Pharmacology and Physiology University of Rochester School of Medicine and DentistryRochesterNYUSA Department of Medicine University of Rochester School of Medicine and DentistryRochesterNYUSA Department of Microbiology and Immunology University of Rochester School of Medicine and DentistryRochesterNYUSA Department of Pathology and Laboratory Medicine University of Rochester School of Medicine and DentistryRochesterNYUSA.

Platelets have long been studied for their roles in hemostasis and vascular injury repair. However, there is a continually evolving and deepening understanding that platelets initiate and regulate responses to tissue injury and pathogens, leading to platelets now being considered immune modulatory cells [1]. Platelets actively participate in host immune responses directly through pathogen engulfing and killing, or by regulating both innate and adaptive immune responses to infection or tissue injury [2]. Activated platelets promote inflammatory responses to tissue injury or infection by direct contact dependent interactions with immune cells and through indirect interactions via released soluble factors. However, mice that are deficient in platelets have skewed T helper cell differentiation [3] and increased vascular permeability [4], implying poorly defined roles for platelets in maintaining healthy immune homeostasis.

关键词： Platelet homeostasis Immune

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Standardizing MI-TliF, a Proposal for a Reproducible Technique

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Open Journal of Modern neurosurgery 2024年第2期14卷 91-103页

作者： Iván Ulises Sámano López Jesús Alberto Pérez Contreras Emmanuel Cantú chávez Diana chávez lizárraga Ana Sofía Peña Blesa Thania Karina Gutiérrez Anch.ndo Á ngeles Pedregal Ciudad de México México

Background: Minimally invasive transforaminal lumbar interbody fusion (MI TliF) is a widely known and performed technique, however its versatility among different physicians continues to hinder its replication and results. Therefore, this study aimed to provide a step-by-step surgical guide to perform a safe MI-TliF, based on the results obtained in patients operated on by a single surgeon over a period of 12 years. Patients and methods: A retrospective, single center, longitudinal, and observational cohort study was conducted with 931 patients who underwent MI TliF by a single surgeon between 2010 and 2022 using the technique described on this paper, each with a minimum follow-up of 12 months. Criteria included Schizas classification, listhesis according to Meyerding classification, number of levels treated, cage size, and complications (screw repositioning or cerebrospinal fluid leak). Patient clinical outcomes were assessed using the Oswestry Disability Index (ODI), Visual Analog Scale (VAS) for pre- and postoperative radicular pain. Thin slice CT scans were used to assess the progression of the fusion using the Bridwell classification. In the statistical analysis, percentages, median, and interquartile range (IQR) were calculated. Results: nine hundred and thirty one patients underwent MI TliF using the technique described, eight hundred and eighty (94.5%) had a single level treated and fifty one (5.5%) had a 2 level procedure (982 levels), an 8mm cage was placed on five hundred and seventeenlevels (52.7%), six hundred and sixty three levels(67.6%) achieved grade I fusion, two hundred and sixty six levels (27.1%) achieved grade II fusion, 52 levels (5.3) achieved grade III fusion and one level (0.1) achieved a grade IV fusion or non-union. Revision surgery was performed on 3 patients (0.3%) for screw repositioning, cerebrospinal fluid leak was present on 2 patients during surgery and treated before closure. VAS scores and ODI were improved at 12 months postop (V

关键词： MITliF Lumbar Interbody Fusion Technique Pain Relief and Disability

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Academic Stress Assessment Using Virtual Reality as an Educational Tool in Spine Surgery

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Open Journal of Modern neurosurgery 2024年第2期14卷 114-123页

作者： Diana chávez lizárraga Jesús Alberto Pérez Contreras Fernando Alvarado Gómez Evelyn Quintero Medina Emmanuel Cantú chávez Iván Ulises Sámano López Ana Sofía Peña Blesa Department of neurosurgery ángeles Pedregal Ciudad de México México Department of Traumatology and Orthopedics Hospital Santa Fe Bogotá Colombia

Introduction: The evaluation of academic stress in medical students and residents is a topic of significant interest, given the considerable challenges they face during their learning process with traditional teach.ng methods. The use of technologies like virtual reality presents an opportunity to enhance their skills through simulations and training. The main objective of this study is to qualitatively assess the stress levels experienced by medical students and residents by integrating virtual reality into their current learning methods, aiming to improve their ability to manage stressors in their practice. Material and Methods: A questionnaire was conducted with 12 medical students and 12 Traumatology and orthopedics residents. The purpose of the questionnaire was to evaluate the levels of academic stress using the SISCO inventory. The stress levels were calculated by transforming average values into percentages, and the following criteria were assigned: 0 to 33% for Mild Stress, 34 to 66% for Moderate Stress, and 67 to 100% for Deep Stress. Then, a virtual reality class focused on spine surgery was provided. Both medical students and residents were trained using the non nocere SharpSurgeon software platform and Oculus Quest 2 virtual reality glasses. At the end of the session, a second questionnaire related to the practice with virtual reality was conducted with the same evaluation criteria and a comparative analysis was carried out. Results: 12 undergraduate students from Hospital Angeles Mexico, CDMX and 12 traumatology and orthopedics residents at Hospital Santa Fe, Bogota were evaluated. The students in CDMX reported an average qualitative stress of 28.50% during habitual practices, which decreased to an average of 14.67% after virtual reality practice. Residents in Bogotá experienced an average qualitative stress of 30.50% with their current learning methods but this reduced to an average of 13.92% after using virtual reality. These findings indicate that t

关键词： Virtual Reality Academic Stress Learning Strategies Spine Surgery Training

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