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苯丙氨酸解氨酶在催化反式苯丙烯酸向L-苯丙氨酸转化中新的稳定作用

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氨基酸和生物资源 1988年第2期16卷 36-42页

作者： christopher t.evans Dayle Canrad Kin Hanna 李广武武汉大学生物系

用分离株SPA1O从反式苯丙烯酸生产的L-辈丙氨酸产量减少到起初观测的26%,起初的实验是生产菌与新鲜底物二次作用而进行的。含苯丙氨酸解氨酶细胞的稳定性(再用可能性)明显地受反式苯丙烯酸盐的浓度和最初反应pH的影响。使用2%的反式苯... 详细信息

用分离株SPA1O从反式苯丙烯酸生产的L-辈丙氨酸产量减少到起初观测的26%,起初的实验是生产菌与新鲜底物二次作用而进行的。含苯丙氨酸解氨酶细胞的稳定性(再用可能性)明显地受反式苯丙烯酸盐的浓度和最初反应pH的影响。使用2%的反式苯丙烯酸盐,L-苯丙氨酸的产量在PH9.0连续培养3次后比在最适pH10.2时的产量大7倍。细胞在存在有5%的反式苯丙烯酸盐时的作用相当不稳定。渗透因子,如甲苯、二甲苯能促进L-本丙氨酸的合成量,但同时也会增加苯丙氨酸解氨酶的不稳定性。有几种效应物表明对苯丙氨酸解氨酶的起始转化速率起促进作用,但只有山梨醇,藻酸盐,戌二醛,聚乙二醇和甘油使其具一定程度的稳定性。用不同的气体对培养物和生物反应器进行通气搅动,表明氧气促进苯丙氨酸解氨酶失活,二氧化碳有少的影响,而氮气使苯丙氨酸解氨酶活性在培养基中几个星期都具明显的稳定性。氯离子的存在(来自HCl)以及底物的通气搅动降低酶的再用可能性,用硫酸取代盐酸,并用氮气进行通气搅动,在26℃时,导致极好的最初转化速率,并且酶活相当稳定,但在30℃时效果差些,反应物中含有1.5M山梨醇使苯丙氨酸解氨酶活性稳定连续维持几个培养周期。

关键词：苯丙烯酸 L-苯丙氨酸苯丙氨酸解氨酶转化速率生物反应器细胞转化分离株藻酸盐氯离子培养物

Exploring impacts of COVID-19 on spatial and temporal patterns of visitors to Canadian Rocky Mountain National Parks from social media big data

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Journal of Forestry Research 2024年第4期35卷 13-33页

作者： Dehui Christina Geng Amy Li Jieyu Zhang Howie W.Harshaw christopher Gaston Wanli Wu Guangyu Wang National Park Research Centre Faculty of ForestryUniversity of British ColumbiaVancouver V6T 1Z4Canada Faculty of Applied Science University of British ColumbiaVancouver V6T 1Z3Canada Paul G.Allen School of Computer Science&Engineering University of WashingtonSeattleWA 98195USA Faculty of Kinesiology Sportand RecreationUniversity of AlbertaEdmonton T6G 2J9Canada Department of Wood Science Faculty of ForestryUniversity of British ColumbiaVancouver V6T 1Z4Canada

COVID-19 posed challenges for global tourism *** in visitor temporal and spatial patterns and their associated determinants pre-and peri-pandemic in Canadian Rocky Mountain National Parks are *** was collected through social media programming and analyzed using spatiotemporal analysis and a geographically weighted regression(GWR)*** highlight that COVID-19 significantly changed park visitation *** tended to explore more remote areas *** GWR model also indicated distance to nearby trails was a significant influence on visitor *** results indicate that the pandemic influenced tourism temporal and spatial *** research presents a novel approach using combined social media big data which can be extended to the field of tourism management,and has important implications to manage visitor patterns and to allocate resources efficiently to satisfy multiple objectives of park management.

关键词： tourism management Social media big data National parks COVID-19 Geographical weighted regression

Dynamics of self-hybridized exciton–polaritons in 2D halide perovskites

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Light(Science & Applications) 2024年第1期13卷 13-22页

作者： Surendra B.Anantharaman Jason Lynch christopher E.Stevens christopher Munley Chentao Li Jin Hou Hao Zhang Andrew torma thomas Darlington Francis Coen Kevin Li Arka Majumdar PJames Schuck Aditya Mohite Hayk Harutyunyan Joshua R.Hendrickson Deep Jariwala Department of Electrical and Systems Engineering University of PennsylvaniaPhiladelphiaPA19104USA KBR Inc. BeavercreekOH45431USA Air Force Research Laboratory Sensors DirectorateWright-Patterson Air Force BaseOH45433USA Department of Physics University of WashingtonSeattleWA98195USA Department of Physics Emory UniversityAtlantaGA30322USA Department of Chemical and Biomolecular Engineering Rice UniversityHoustonTX77005USA Department of Materials Science and Nanoengineering Rice UniversityHoustonTX77005USA Applied Physics Program Smalley‐Curl InstituteRice UniversityHoustonTX77005USA Department of Mechanical Engineering Columbia UniversityNew YorkNY10027USA Department of Electrical and Computer Engineering University of WashingtonSeattleWA98195USA

Excitons,bound electron–hole pairs,in two-dimensional hybrid organic inorganic perovskites(2D HOIPs)are capable of forming hybrid light-matter states known as exciton-polaritons(E–Ps)when the excitonic medium is confined in an optical *** the case of 2D HOIPs,they can self-hybridize into E–Ps at specific thicknesses of the HOIP crystals that form a resonant optical cavity with the ***,the fundamental properties of these self-hybridized E–Ps in 2D HOIPs,including their role in ultrafast energy and/or charge transfer at interfaces,remain ***,we demonstrate that>0.5µm thick 2D HOIP crystals on Au substrates are capable of supporting multiple-orders of self-hybridized E–P *** E–Ps have high Q factors(>100)and modulate the optical dispersion for the crystal to enhance sub-gap absorption and *** varying excitation energy and ultrafast measurements,we also confirm energy transfer from higher energy E–Ps to lower energy E–***,we also demonstrate that E–Ps are capable of charge transport and transfer at *** findings provide new insights into charge and energy transfer in E–Ps opening new opportunities towards their manipulation for polaritonic devices.

关键词： charge polar excitation

tHE tRANSFORMAtION OF tHE StAtE OF NItROGEN IN DIAMOND

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Science in China,Ser.B 1985年第10期 1009-1021页

作者：亓曾笃 t.evans Shanghai Institute of Ceramics Academia Sinica University of Reading England

Synthetic type Ib diamonds have been treated in the temperature range of 1500℃—2500℃ under stabilizing pressures of 6.5 GPa and 9.5 GPa. All nitrogen aggregates found in natural type Ia diamonds have been produeed. the single substitutional nitrogen was converted into A-centres, B-centres and N3-centres. the 7,3 μm peak of the infrared absorption spectrum and the associated platelets have been farmed. the synthetic type Ib diamonds have become much harder after heat treatment at above 2000℃ under a stabilizing pressure of about 9.5 GPa. Natural type Ia diamonds have been treated up to 2700℃ under a stabilizing pressure of about 9.5 GPa. the 7.3μm, 7.8μm, 8.5μm, 9.1μm, 9.9μm absorption peaks in infrared absorption spectrum have been changed. A-centres have been converted into B-centres and broken up into single nitrogen atoms, forming N3-centres.

关键词： tHE tRANSFORMAtION OF tHE StAtE OF NItROGEN IN DIAMOND

Subpopulations of regulatory t cells are associated with subclinical atherosclerotic plaques,levels of LDL,and cardiorespiratory fitness in the elderly

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Journal of Sport and Health Science 2024年第3期13卷 288-296,I0002页

作者： tim Böttrich Pascal Bauer Vincent Gröβer Magdalena Huber Hartmann Raifer torsten Frech Svenja Nolte theresa Dombrowski Franz Cemic Natascha Sommer Robert Ringseis Klaus Eder Karsten Krüger christopher Weyh Department of Exercise Physiology and Sports therapy Institute of Sports ScienceJustus-Liebig-UniversityGiessen 35394Germany Department of Cardiology and Angiology Justus-Liebig-University GiessenGiessen 35392Germany Institute for Systems Immunology Center for Tumor und ImmunologyMarburg 35032Germany tH Mittelhessen Department of Computer ScienceUniversity of Applied Sciences GiessenGiessen 35390Germany Department of Internal Medicine Universities of Giessen and Marburg Lung Center(UGMLC)Member of the German Center for Lung Research(DZL)Giessen 35394Germany Excellence Cluster Cardio-Pulmonary Institute(CPI) Justus-Liebig UniversityGiessen 35394Germany Institute of Animal Nutrition and Nutrition Physiology Justus-Liebig-University GiessenGiessen 35390Germany

Background:Atherosclerosis forms the pathological basis for the development of cardiovascular *** pathological processes initially develop without clinically relevant symptoms,the identification of early markers in the subclinical stage plays an important role for initiating early *** is evidence that regulatory t cells(tregs)are involved in the development of ***,the present study aimed to identify and investigate associations with tregs and their subsets in a cohort of healthy elderly individuals with and without subclinical atherosclerotic plaques(SAP).In addition,various lifestyle and risk factors,such as cardiorespiratory fitness,were investigated as associated ***:A cross-sectional study was performed in 79 participants(male:n=50;age=63.6±3.7 years;body mass index=24.9±3.1 kg/m2;mean±SD)who had no previous diagnosis of chronic disease and were not taking *** of the carotids to identify SAP,cardiovascular function measurement for vascular assessment and a cardiorespiratory fitness test to determine peak oxygen uptake were ***,tests were conducted to assess blood lipids and determine glucose *** of tregs and their subtypes(resting(rtregs)and effector/memory(mtregs))was performed by 8-chanel flow *** were categorized according to atherosclerotic plaque *** and logistic regression models were used to analyze associations between ***:SAP was detected in a total of 29 *** participants with plaque were older(64.8±3.6 years vs.62.9±3.5 years)and had higher peripheral systolic blood pressure(133.8±14.7 mmHg vs.125.8±10.9 mmHg).the participants with SAP were characterized by a lower percentage of rtregs(28.8%±10.7%vs.34.6%±10.7%)and a higher percentage of mtregs(40.3%±14.7%vs.30.0%±11.9%).Multiple logistic regression identified age(odds ratio(OR)=1.20(95%confidence interval(95%CI):1.011.42))and

关键词： Cardiorespiratory fitness Elderly Regulatory t cells Subclinical atherosclerosis

Coverage and determinants of infant postnatal care in Nigeria:A population-based cross-sectional study

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Pediatric Investigation 2024年第1期8卷 27-36页

作者： Bolaji Emmanuel Egbewale Olusola Oyedeji Jesse Bump christopher Robert Sudfeld Department of Global Health and Population Takemi Program in International HealthHarvard T.H.Chan School of Public HealthBostonMassachusettsUSA Department of Community Medicine College of Health SciencesLadoke Akintola University of TechnologyOgbomosoNigeria Department of Pediatrics and Child Health College of Health SciencesLadoke Akintola University of TechnologyOgbomosoNigeria

Importance:In 2019,Nigeria had the largest number of under-5 child deaths globally and many of these deaths occurred within the first week of *** World Health Organization recommends infant postnatal care(PNC)attendance to support newborn survival;however,utilization of PNC is known to be low in many ***:this study examined coverage and individual-level determinants of infant PNC attendance in ***:Nigeria Demographic Health Survey(NDHS)2018 data were used to evaluate infant PNC coverage and *** PNC was defined as receipt of care within 2 days of *** delivered up to 2 years before the 2018 NDHS were *** examined predictors of infant PNC with modified Poisson regression models to estimate relative risks(RRs).Results:the national coverage of infant PNC was 37.3%(95%confidence interval[CI]:35.8%–38.7%).Significant heterogeneity in PNC attendance existed at state and regional *** delivery was strongly associated with the uptake of PNC(RR:6.07;95%CI:5.60–6.58).Greater maternal education,maternal employment,urban residence,female head of household,and greater wealth were also associated with an increased likelihood of PNC ***:the uptake of infant PNC is low and interventions are urgently needed to promote equity in access and increase demand for PNC in Nigeria.

关键词： Infant postnatal care Epidemiology Coverage Determinants Nigeria

Recent advances in the understanding and management of chronic pancreatitis pain

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Journal of Pancreatology 2024年第1期7卷 35-44页

作者： Jessica Walker Olivia L.Babyok Jami L.Saloman Anna evans Phillips Department of Internal Medicine University of Pittsburgh Medical CenterPittsburghPAUnited States Division of Gastroenterology Hepatology and NutritionDepartment of MedicineSchool of MedicineUniversity of PittsburghPittsburghPAUnited States Center for Pain Research Center for NeuroscienceSchool of MedicineUniversity of PittsburghPittsburghPAUnited States

Abdominal pain is the most common symptom of chronic pancreatitis(CP)and is often debilitating for patients and very difficult to *** date,there exists no cure for the *** strategies focus on symptom management and on mitigation of disease progression by reducing toxin exposure and avoiding recurrent inflammatory *** treatment protocols start with medical management followed by consideration of procedural or surgical intervention on selected patients with severe and persistent *** incorporation of adjuvant therapies to treat comorbidities including psychiatric disorders,exocrine pancreatic insufficiency,mineral bone disease,frailty,and malnutrition,are in its early *** clinical studies and animal models have been designed to improve investigation into the pathophysiology of CP pain,as well as to improve pain *** the array of tools available,many therapeutic options for the management of CP pain provide incomplete *** still remains much to discover about the neural regulation of pancreas-related *** this review,we will discuss research from the last 5 years that has provided new insights into novel methods of pain phenotyping and the pathophysiology of CP *** discoveries have led to improvements in patient selection for optimization of outcomes for both medical and procedural management,and identification of potential future therapies.

关键词： Central sensitization Chronic pancreatitis Pain phenotyping Peripheral sensitization

SARS-CoV-2 RBD and Its Variants Can Induce Platelet Activation and Clearance:Implications for Antibody therapy and Vaccinations against COVID-19

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Research 2024年第3期2023卷 1-15页

作者： Xiaoying Ma Jady Liang Guangheng Zhu Preeti Bhoria Aron A.Shoara Daniel t.MacKeigan christopher J.Khoury Sladjana Slavkovicl Lisha Lin Danielle Karakas Ziyan Chen Viktor Prifti Zhenze Liu Chuanbin Shen Yuchong Li Cheng Zhang Jiayu Dou Zack Rousseau Jiamin Zhang tiffany Ni Xi Lei Pingguo Chen Xiaoyu Wu Hamed Shaykhalishahi Samira Mubareka Kim AConnelly Haibo Zhang Ori Rotstein Heyu Ni Department of Laboratory Medicine and Pathobiology University of TorontoTorontoONCanada Department of Laboratory Medicine Keenan Research Centre for Biomedical Science of St.Michael’s HospitalTorontoONCanada toronto Platelet Immunobiology Group TorontoONCanada Department of Physiology University of TorontoTorontoONCanada CCOA therapeutics Inc. TorontoONCanada Canadian Blood Services Centre for Innovation TorontoONCanada the State Key Laboratory of Respiratory Disease Guangzhou Institute of Respiratory DiseaseThe First Affiliated Hospital of Guangzhou Medical UniversityGuangzhouGuangdongChina Department of Laboratory Medicine The Second Affliated Hospital of Guangzhou University of Chinese MedicineGuangzhouChina Advanced Pharmaceutics&Drug Delivery Laboratory Leslie Dan Faculty of PharmacyUniversity of TorontoTorontoONCanada Department of Medical Microbiology and Infectious Disease Sunnybrook Health Science CentreToronto ONCanada Department of Medicine University of TorontoTorontoONCanada Division of Cardiology.St.Michael's Hospital TorontoONCanada Department of Anesthesiology and Pain Medicine and Division of Critical Care Medicine University of TorontoTorontoONCanada interdepartmental Division of Critical Care Medicine University of TorontoTorontoONCanada Department of Surgery University of Toronto TorontoONCanada.

the COVID-19 pandemic caused by SARS-CoV-2 virus is an ongoing global health *** cases of COVID-19 and the rare cases of COVID-19 vaccine-induced-thrombotic-thrombocytopenia(VItt)are both associated with thrombosis and thrombocytopenia;however,the underlying mechanisms remain inadequately *** infection and vaccination utilize the spike protein receptor-binding domain(RBD)of *** found that intravenous injection of recombinant RBD caused significant platelet clearance in *** investigation revealed the RBD could bind platelets,cause platelet activation,and potentiate platelet aggregation,which was exacerbated in the Delta and Kappa *** RBD–platelet interaction was partially dependent on theβ3 integrin as binding was significantly reduced inβ3−/−***,RBD binding to human and mouse platelets was significantly reduced with relatedαIIbβ3 antagonists and mutation of the RGD(arginine-glycine-aspartate)integrin binding motif to RGE(arginine-glycine-glutamate).We developed anti-RBD polyclonal and several monoclonal antibodies(mAbs)and identified 4F2 and 4H12 for their potent dual inhibition of RBD-induced platelet activation,aggregation,and clearance in vivo,and SARS-CoV-2 infection and replication in Vero E6 *** data show that the RBD can bind platelets partially thoughαIIbβ3 and induce platelet activation and clearance,which may contribute to thrombosis and thrombocytopenia observed in COVID-19 and *** newly developed mAbs 4F2 and 4H12 have potential not only for diagnosis of SARS-CoV-2 virus antigen but also importantly for therapy against COVID-19.

关键词： Antibody diagnosis vaccine

Predicting pollutant removal in constructed wetlands using artificial neural networks(ANNs)

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Water Science and Engineering 2020年第1期13卷 14-23页

作者： christopher Kiiza Shun-qi Pan Bettina Bockelmann-evans Akintunde Babatunde Hydro-environmental Research Centre School of EngineeringCardiff UniversityThe ParadeCardiff CF243AAUK School of Civil Engineering University of LeedsLeeds LS29JTUK

Growth in urban population,urbanisation,and economic development has increased the demand for water,especially in water-scarce ***,sustainable approaches to water management are needed to cope with the effects of the urbanisation on the water *** study aimed to design novel configurations of tidal-flow vertical subsurface flow constructed wetlands(VFCWs)for treating urban stormwater.A series of laboratory experiments were conducted with semi-synthetic influent stormwater to examine the effects of the design and operation variables on the performance of the VFCWs and to identify optimal design and operational strategies,as well as maintenance *** results show that the VFCWs can significantly reduce pollutants in urban stormwater,and that pollutant removal was related to specific VFCW *** based on the artificial neural network(ANN)method were built using inputs derived from data exploratory techniques,such as analysis of variance(ANOVA)and principal component analysis(PCA).It was found that PCA reduced the dimensionality of input variables obtained from different experimental design *** results show a satisfactory generalisation for predicting nitrogen and phosphorus removal with fewer variable inputs,indicating that monitoring costs and time can be reduced.

关键词： Constructed wetlands Urban stormwater Pollutant removal Artificial neural networks(ANNs) Principal component analysis(PCA)