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stabilization and detection of labile reaction intermediates in supramolecular containers

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Chinese Chemical Letters 2024年第6期35卷 47-52页

作者： Rui Wang Yang Liang Julius Rebek jr. Yang Yu Center for supramolecular Chemistry&Catalysis and Department of Chemistry College of ScienceShanghai UniversityShanghai 200444China skaggs Institute for Chemical Biology and Department of Chemistry The Scripps Research InstituteLa JollaCA 92037United States

Detection and observation of reactive intermediates is an essential step in investigation of reaction ***,most reactive intermediates are unstable and present at low concentrations;their short lifetimes make them difficult to detect and *** containers offer opportunities for the stabilization and characterization of those labile species,through isolation from the media and protection inside the cavity of the *** this review,we summarize the examples of labile reaction intermediates that are stabilized and characterized with the help of supramolecular *** container compounds include carcerands,deep cavitands and amide *** focus on unstable guest species-cyclobutadiene,benzocyclopropenone,o-benzyne,1,2,4,6-cycloheptatetraene,anti-Bredt's olefin,fluorophenoxycarbene,O-acylisoamide,and hemiaminalthat act as intermediates in certain organic reactions.

关键词： supramolecular containers Reaction intermediates Labile species stabilization short-lived species detection supramolecular chemistry

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Localized-states quantum confinement induced by roughness in CdMnTe/CdTe heterostructures grown on si(111) substrates

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Journal of semiconductors 2024年第9期45卷 28-35页

作者： Leonarde N.Rodrigues Wesley F.Inoch Marcos L.F.Gomes Odilon D.D.Couto jr. Bráulio s.Archanjo sukarno O.Ferreira Physics Department Federal University of ViçosaViçosa36570-900Minas GeraisBrazil Instituto de Física Gleb Wataghin Universidade Estadual de CampinasCampinas13083-859São PauloBrazil National Institute of Metrology Quality and Technology(Inmetro) Materials Metrology Division(DIMAT)Xerém2525-020Rio de JaneiroBrazil

This work shows that despite a lattice mismatch of almost 20%, CdMnTe/CdTe/CdMnTe heterostructures grown directly on si(111) have surprisingly good optical emission properties. The investigated structures were grown by molecular beam epitaxy and characterized by scanning transmission electron microscopy, macro-and micro-photoluminescence. Low temperature macro-photoluminescence experiments indicate three emission bands which depend on the CdTe layer thickness and have different confinement characteristics. Temperature measurements reveal that the lower energy emission band (at 1.48 eV)is associated to defects and bound exciton states, while the main emission at 1.61 eV has a weak 2D character and the higher energy one at 1.71 eV has a well-defined (zero-dimensional, 0D) 0D nature. Micro-photoluminescence measurements show the existence of sharp and strongly circularly polarized (up to 40%) emission lines which can be related to the presence of Mn in the heterostructure. This result opens the possibility of producing photon sources with the typical spin control of the diluted magnetic semiconductors using the low-cost silicon technology.

关键词： CdMnTe/CdTe/CdMnTe heterostructure CdTe/CdMnTe quantum emitters quantum dot-like emission silicon(111)substrate

Biliary complications associated with weight loss,cholelithiasis and choledocholithiasis

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World Journal of Gastrointestinal Pharmacology and Therapeutics 2024年第4期15卷 1-8页

作者： Marcelo A Ribeiro jr Gabriela K Tebar Helena B Niero Leticia s Pacheco Department of surgery Division of TraumaCritical Care and Acute Care SurgerySheikh Shakhbout Medical CityAbu Dhabi 11001United Arab Emirates Department of surgery Pontifical Catholic University of São Paulo-Campus SorocabaSorocaba 18030070SPBrazil

Biliary complications like cholelithiasis and choledocholithiasis are more common in bariatric surgery patients due to obesity and rapid weight *** with a body mass index>40 face an eightfold risk of developing *** surgery,especially after laparoscopic Roux-en-Y gastric bypass(LRYGB),30%of patients develop biliary disease due to rapid weight *** aim of this review is to analyze the main biliary complications that occur after bariatric surgery and its management.A review of the literature was conducted mainly from 2010 up to 2023 with regard to biliary complications associated with bariatric patients in sciELO,PubMed,and *** undergoing LRYGB have a higher incidence(14.5%)of symptomatic calculi post-surgery compared to those undergoing laparoscopic sleeve gastrectomy at 4.1%.Key biliary complications within 6 to 12 months post-surgery include:Cholelithiasis:36%;Biliary colic/dyskinesia:3.86%;Acute cholecystitis:0.98%-18.1%;Chronic cholecystitis:70.2%;Choledocholithiasis:0.2%-5.7%and Pancreatitis:0.46%-9.4%.surgeons need to be aware of these complications and consider surgical treatments based on patient symptoms to enhance their quality of life.

关键词： Bariatric surgery Complications Choledocholithiasis Cholelithiasis Acute cholecystitis

Advancements in Catalysts for Electrochemical Nitrate Reduction: A sustainable Approach for Mitigating Nitrate Pollution: A Review

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Modern Research in Catalysis 2024年第1期13卷 1-28页

作者： Gerald D. s. Quoie jr. Jean Pierre Bavumiragira Varney Kromah state Key Laboratory of Pollution Control and Resources Reuse College of Environmental Science and Engineering Tongji University Shanghai China Key Laboratory of Yangtze River Water Environment Ministry of Education Tongji University Shanghai China Department of Mining Engineering College of Engineering University of Liberia Monrovia Liberia

Nitrate pollution is of great importance in both the environmental and health contexts, necessitating the development of efficient mitigation strategies. This review provides a comprehensive analysis of the many catalysts employed in the electrochemical reduction of nitrate to ammonia, and presents a viable environmentally friendly approach to address the issue of nitrate pollution. Hence, the electrochemical transformation of nitrate to ammonia serves the dual purpose of addressing nitrate pollution in water bodies, and is a useful agricultural resource. This review examines a range of catalyst materials such as noble and non-noble metals, metal oxides, carbon-based materials, nitrogen-doped carbon species, metal complexes, and semiconductor photocatalysts. It evaluates catalytic efficiency, selectivity, stability, and overall process optimization. The performance of catalysts is influenced by various factors, including reaction conditions, catalyst structure, loading techniques, and electrode interfaces. Comparative analysis was performed to evaluate the catalytic activity, selectivity, Faradaic efficiency, current density, stability, and durability of the catalysts. This assessment offers significant perspectives on the structural, compositional, and electrochemical characteristics that affect the efficacy of these catalysts, thus informing future investigations and advancements in this domain. In addition to mitigating nitrate pollution, the electrochemical reduction of nitrate to ammonia is in line with sustainable agricultural methods, resource conservation, and the utilization of renewable energy resources. This study explores the factors that affect the catalytic efficiency, provides new opportunities to address nitrate pollution, and promotes the development of sustainable environmental solutions.

关键词： Nitrate Pollution Electrochemical Reduction Ammonia sustainable Farming Catalysts

Water scarcity in Conakry, Guinea: Challenges and Proposed strategies for a Way Forward

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Journal of Water Resource and Protection 2024年第4期16卷 264-280页

作者： Bernard Lassimo Diawara Gerald D. s. Quoie jr Zhuo Li Justin Junior Loua College of Environmental science and Engineering Tongji University Shanghai China UNEP-Tongji Institute of Environment for sustainable Development Tongji University Shanghai China state Key Laboratory of Pollution Control and Resources Reuse Tongji University Shanghai China Business school Sichuan University Chengdu China

The capital of Guinea, Conakry, faces a notable difficulty due to a water shortage, which is worsened by the rapid increase in population and urban development. The Guinean Water Company (sEG) faces challenges in supplying water to the entire city due to its limited area of approximately 420 kmsup>2sup> and a population of 2 million. Moreover, the population growth rate is anticipated to increase dramatically, exacerbating the difficulty of fulfilling future water requirements. As a result, this study employs data from the Knoema website and the Institute of National statistics of Guinea (INs) to examine the water production and distribution process by the sEG. The study examines the challenges related to water scarcity in Conakry and suggests strategies to assist the city in managing the present circumstances and planning for the future. The primary objective is to get a long-lasting water supply and uphold water quality to advance public health.

关键词： Water scarcity Conakry Population Growth sDGs sEG

Between Quantum Mechanics and General Relativity

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Journal of Modern Physics 2024年第8期15卷 1199-1228页

作者： Walter James Christensen jr. Department of Physics and Astronomy Cal Poly Pomona University Pomona USA

The origin of elementary particle mass is considered as a function of n-valued graviton quanta. To develop this concept we begin in a cold region of “empty space” comprised of only microscopic gravitons oscillating at angular frequency ω. From opposite directions enters a pair of stray protons. Upon colliding, heat and energy are released. Customarily, this phase and what follows afterward would be described by Quantum Chromodynamics (QCD). Instead, we argue for an intermediary step. One in which neighboring gravitons absorb discrete amounts of plane-wave energy. Captured by the graviton, the planewave becomes a standing wave, whereupon its electromagnetic energy densities are converted into gravitational quanta. Immediately thereafter an elementary particle is formed and emitted, having both mass and spin. From absorption to conversion to emission occurs in less than 3.7 × 10−16 s. During this basic unit of hybrid time, general relativity and quantum physics unite into a common set of physical laws. As additional stray protons collide the process continues. Over eons, vast regions of spacetime become populated with low-mass particles. These we recognize to be dark matter by its effects on large scale structures in the universe. Its counterpart, dark energy, arises when the conversion of gravitational quanta to particle emission is interrupted. This causes the gravitational quanta to be ejected. It is recognized by its large scale effects on the universe.

关键词： Dark Matter and Energy Gravitational Quanta Graviton standing Wave schwarzschild Metric General Relativity Quantum Physics Unified Field Theory Blackholes

Localized-states quantum confinement induced by roughness in CdMnTe/CdTe heterostructures grown on si(111) substrates

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Journal of semiconductors 2024年第9期 34-42页

作者： Leonarde do Nascimento Rodrigues Wesley Fiorio lnoch Marcos L.F.Gomes Odilon D.D.Couto jr. Bráulio s.Archanjo sukarno Olavo Ferreira Physics Department Federal University of Vi?osa Instituto de Física Gleb Wataghin Universidade Estadual de Campinas National Institute of Metrology Quality and Technology (Inmetro) Materials Metrology Division (DIMAT)

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For cervical cancer screening,which test is better,and forwhom?

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Gynecology and Obstetrics Clinical Medicine 2024年第2期4卷 77-78页

作者： Edward J Mayeaux jr Yun Zhao UsC school of Medicine Columbia Affiliate of Family and Preventive Medicine USC School of Medicine LibraryColumbiaSouth CarolinaUSA Peking University People's Hospital BeijingChina

In their January 2024 article,Vahteristo et al reported the results of their prospective randomised trial comparing human papillomavirus(HPV)-basedcervical cancer screening versus cytologyyscreening gin southern *** study examined using high-risk HPV(hrHPV)-based cervical cancer screening in Finland,a country with awell-established,high-qualitycytology screening programme and a low incidence of cervical *** 236000 individuals were involved in this long-term follow-up of the Finnish randomised HPV screening *** authors calculated the cervical cancer incidence and mortality rate ratios using Poisson regression.

关键词： cervical cancer mortality

Extreme drought triggers parallel shifts in wood anatomical and physiological traits in upper treeline of the Mediterranean Andes

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Ecological Processes 2024年第1期13卷 132-143页

作者： Luiz santini jr. Dylan Craven Daigard Ricardo Ortega Rodriguez Manolo Trindade Quintilhan stephanie Gibson-Carpintero Cristina Aravena Torres Fidel A.Roig Ariel A.Mu?oz Alejandro Venegas-Gonzalez Hémera Centro de Observación de la Tierra Universidad Mayor GEMA Center for Genomics Ecology and Environment Universidad Mayor Data Observatory Foundation ANID Technology Center Depart-ment of Forest sciences ESALQ-University of Sao Paulo Department of Plant Biology Institute of Biology University of Campinas Instituto de Geografía Universidad Nacional Autónoma de México (UNAM) Argentine Institute of Nivology Glaciology and Environmental Sciences(IANIGLA CONICET ) Institute of Geography Pontificia Universidad Católica de Valparaíso Instituto de Ciencias Agroalimentarias Animales y Ambientales (ICA3) Universidad de O'Higgins

Background Treeline ecotones of Mediterranean ecoregions have been affected by the increasing intensity and severity of droughts. Even though the effect of droughts on forest dynamics has been widely documented, knowledge is relatively scarce of how extreme climate episodes affect the hydraulic structure and, therefore, the phys-iology of woody plants. The Mediterranean Andes have experienced an uninterrupted period of drought since 2010, including an extremely dry year in 2019 with approximately 80% rainfall deficit. Here, we investigated shifts in wood anatomical and physiological traits of Kageneckia angustifolia, an endemic treeline species, in response to this drought *** We evaluated the xylem plasticity of three K. angustifolia populations across their natural distribution(31–35° sL) based on anatomical(vessel structure and distribution) and physiological(intrinsic water-use efficiency) variables in the tree rings. We focused on the period 2000–2020 that corresponds to before the megadrought(2000–2007),(ii) megadrought(2008–2018) and(iii) hyperdrought(2019–2020). The variables were annualized and analyzed by linear mixed-effects *** Our results provide insights to the anatomical and physiological mechanisms underlying the resilience of treeline forests to persistent droughts in central Chile. We found that the extreme drought in 2019–2020 triggered shifts in vessel size and frequency that increased hydraulic safety. These significant shifts in vessel traits occurred in parallel with a decrease in pit aperture area and an increase in water-use efficiency, further increasing the resilience of K. angustifolia to extreme drought *** Our results revealed coordinated shifts in vessel size and frequency and water-use efficiency in response to the megadrought, thereby reducing vulnerability to hydraulic failure. The apparent resilience of K. angustifolia to extreme droughts suggests that this adaptation to drought stress may incre

关键词： Dendro-anatomy Kageneckia angustifolia Xylem vulnerability Drought Climate change