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Journal of Pharmaceutical Analysis 2016年第4期6卷 242-248页

作者： Ruchir Bhomia Vivek Trivedi Nichola J.coleman john c.mitchell School of Science University of GreenwichCentral Avenue

The effects of temperature,pH and long-term storage on the secondary structure and conformation changes of bovine haemoglobin（bHb） were studied using circular dichroism（cD） and ultraviolet-visible（UV-vis） *** network software was used to deconvolute the cD data to obtain the fractional content of the five secondary *** storage stability of bHb solutions in pH 6,7 and8 buffers was significantly higher at 4 ℃ than at 23 ℃ for the first 3 days.A complete denaturation of bHb was observed after 40 days irrespective of storage temperature or *** bHb solutions were also exposed to heating and cooling cycles between 25 and 65 ℃ and structural changes were followed by UVvis and cD *** experiments demonstrated that α-helix content of bHb decreased steadily with the increasing temperature above 35 ℃ at all pH *** loss in a-helicity and gain in random coil conformations was pH-dependent and the greatest under alkaline ***,there was minimal recovery of the secondary structure content upon cooling to 25 ℃.The use of bHb as a model drug is very common and this study elucidates the significance of storage and processing conditions on its stability.

关键词： Bovine haemoglobin circular dichroism Thermal stability Storage stability Ultraviolet-visible spectroscopy

Monitoring real time polymorphic transformation of sulfanilamide by diffuse reflectance visible spectroscopy

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Journal of Pharmaceutical Analysis 2016年第3期6卷 179-183页

作者： Tracy O.Ehiwe Bruce D.Alexander john c.mitchell Martin J.Snowden Laura J.Waters Medway centre for Formulation Science Faculty of Engineering and Science University of Greenwich at Medway School of Applied Sciences University of Huddersfield

This study investigated the development of a novel approach to surface characterization of drug poly- morphism and the extension of the capabilities of this method to perform ＇real time＇ in situ measure- ments. This was achieved using diffuse reflectance visible （DRV） spectroscopy and dye deposition, using the pH sensitive dye, thymol blue （TB）. Two polymorphs, SFN-β and SFN-γ, of the drug substance sulfanilamide （SFN） were examined. The interaction of adsorbed dye with polymorphs showed different behavior, and thus reported different DRV spectra. consideration of the acid/base properties of the morphological forms of the drug molecule provided a rationalization of the mechanism of differential coloration by indicator dyes. The kinetics of the polymorphic transformation of SFN polymorphs was monitored using treatment with TB dye and DRV spectroscopy. The thermally-induced transformation fitted a first-order solid-state kinetic model （R2=0.992）, giving a rate constant of 2.43 × 10^- 2 s 1.

关键词： Polymorphic transformation Sulfanilamide Diffuse reflectance visible spectroscopy Powder X-ray diffraction Differential scanning calorimetry

Effect of plasma surface treatment of poly(dimethylsiloxane) on the permeation of pharmaceutical compounds

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Journal of Pharmaceutical Analysis 2017年第5期7卷 338-342页

作者： Laura J.Waters catherine V.Finch A.K.M.Mehedi H.Bhuiyan Karl Hemming john c.mitchell Department of Pharmacy School of Applied Science University of Huddersfield Medway centre for Pharmaceutical Sciences University of Greenwich

This paper addresses the modification of poly(dimethylsiloxane), i.e. PDMS, using plasma surface treatment and a novel application of the membrane created. A set of model compounds were analysed to determine their permeation through PDMS, both with and without plasma treatment. It was found that plasma treatment reduced permeation for the majority of compounds but had little effect on some compounds, such as caffeine,with results indicating that polarity plays an important role in permeation, as is seen in human skin. Most importantly, a direct correlation was observed between plasma-modified permeation data and literature data through calculation of membrane permeability(K_p) values suggesting plasma-modified silicone membrane(PMSM) could be considered as a suitable in vivo replacement to predict clinical skin permeation.

关键词： Permeation PDMS Silicone Plasma Flux Hydrophobicity

Targeting TrkB–PSD-95 coupling to mitigate neurological disorders

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Neural Regeneration Research 2025年第3期20卷 715-724页

作者： Xin Yang Yu-Wen Alvin Huang john Marshall Department of Molecular Biology Cell Biology and BiochemistryBrown UniversityProvidenceRIUSA Department of Neurology Warren Alpert Medical School of Brown UniversityProvidenceRIUSA center for Translational Neuroscience Robert J.and Nancy D.Carney Institute for Brain Science and Brown Institute for Translational ScienceBrown UniversityProvidenceRIUSA

Tropomyosin receptor kinase B(TrkB)signaling plays a pivotal role in dendritic growth and dendritic spine formation to promote learning and *** activity-dependent release of brain-derived neurotrophic factor at synapses binds to pre-or postsynaptic TrkB resulting in the strengthening of synapses,reflected by long-term ***,the association of postsynaptic density protein-95 with TrkB enhances phospholipase cγ-ca^(2+)/calmodulin-dependent protein kinaseⅡand phosphatidylinositol 3-kinase-mechanistic target of rapamycin signaling required for long-term *** this review,we discuss TrkB-postsynaptic density protein-95 coupling as a promising strategy to magnify brain-derived neurotrophic factor signaling towards the development of novel therapeutics for specific neurological disorders.A reduction of TrkB signaling has been observed in neurodegenerative disorders,such as Alzheimer's disease and Huntington's disease,and enhancement of postsynaptic density protein-95 association with TrkB signaling could mitigate the observed deficiency of neuronal connectivity in schizophrenia and *** with brain-derived neurotrophic factor is problematic,due to poor pharmacokinetics,low brain penetration,and side effects resulting from activation of the p75 neurotrophin receptor or the truncated TrkB.T1 *** TrkB agonists and antibodies that activate TrkB are being intensively investigated,they cannot distinguish the multiple human TrkB splicing isoforms or cell type-specific *** TrkB–postsynaptic density protein-95 coupling provides an alternative approach to specifically boost TrkB signaling at localized synaptic sites versus global stimulation that risks many adverse side effects.

关键词： Angelman syndrome autism brain-derived neurotrophic factor depression neurodegenerative disorder neurodevelopmental disorder postsynaptic density protein-95 synaptic plasticity TrkB

cold plasma redistribution throughout geospace

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Science china(Technological Sciences) 2016年第9期59卷 1340-1345页

作者： Foster john c. Massachusetts Institute of Technology Haystack Observatory

The redistribution of the electrically charged cold plasma of ionospheric origin involves the equatorial,low,mid,auroral,and polar-latitude regions in a multi-step,system-wide process linking the regions of *** with ground and space-based instruments characterize the geospace plume-regularly occurring channels of enhanced plasma density flowing at both ionospheric and magnetospheric *** in the SAPS channel transports the eroded material to the noontime cusp in the ionosphere and to the dayside magnetopause at high *** the fluxes of cold plume plasma traverse the cusp and enter the polar cap,they form the polar tongue of *** the cusp the plume plasma provides a rich source of heavy ions for the magnetospheric injection and acceleration via the mechanisms operative on those field lines.

关键词： plasmasphere ionosphere geospace GPS TEc ionospheric electric field plume

Metagenomics: Facts and Artifacts, and computational challenges

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Journal of computer Science & Technology 2010年第1期25卷 71-81页

作者： john c. Wooley 叶玉珍 center for Research on BioSystems Calit2 University of California San Diego School of Informatics and computing Indiana University

Metagenomics is the study of microbial communities sampled directly from their natural environment, without prior culturing. By enabling an analysis of populations including many （so-far） unculturable and often unknown microbes, metagenomics is revolutionizing the field of microbiology, and has excited researchers in many disciplines that could benefit from the study of environmental microbes, including those in ecology, environmental sciences, and biomedicine. Specific computational and statistical tools have been developed for metagenomic data analysis and comparison. New studies, however, have revealed various kinds of artifacts present in metagenomics data caused by limitations in the experimental protocols and/or inadequate data analysis procedures, which often lead to incorrect conclusions about a microbial community. Here, we review some of the artifacts, such as overestimation of species diversity and incorrect estimation of gene family frequencies, and discuss emerging computational approaches to address them. We also review potential challenges that metagenomics may encounter with the extensive application of next-generation sequencing （NGS） techniques.

关键词： metagenomics next-generation sequencing (NGS) taxonomic/functional profiling statistical approaches comparative metagenomics

Materials-oriented integrated design and construction of structures in civil engineering—A review

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Frontiers of Structural and civil Engineering 2022年第1期16卷 24-44页

作者： Xing MING john c.HUANG Zongjin LI Institute of Applied Physics and Materials Engineering University of MacaoMacao SAR 999078China cHc Engineering LLCFairfaxVA 20030USA

Design is a goal-oriented planning activity for creating products,processes,and systems with desired functions through *** is a decision-making exploration:the design outcome may vary greatly depending on the designer’s knowledge and *** design is one type of design philosophy that takes an interdisciplinary and holistic *** civil engineering,structural design is such an activity for creating buildings and ***,structural design in many countries has emphasized a performance-based philosophy that simultaneously considers a structure’s safety,durability,serviceability,and ***,integrated design in civil engineering has become more popular,useful,and ***-oriented integrated design and construction of structures(MIDcS)combine materials engineering and structural engineering in the design stage:it fully utilizes the strengths of materials by selecting the most suitable structural forms and construction *** paper will explore real-world examples of MIDcS,including the realization of MIDcS in timber seismic-resistant structures,masonry arch structures,long-span steel bridges,prefabricated/on-site extruded light-weight steel structures,fiber-reinforced cementitious composites structures,and fiber-reinforced polymer bridge ***,advanced material design methods such as bioinspired design and structure construction technology of additive manufacturing are briefly reviewed and discussed to demonstrate how MIDcS can combine materials and structures.A unified strengthdurability design theory is also introduced,which is a human-centric,interdisciplinary,and holistic approach to the description and development of any civil infrastructure and includes all processes directly involved in the life cycle of the ***,this paper lays out future research directions for further development in the field.

关键词： integrated design and construction fiber-reinforced concrete fiber-reinforced polymer light-weight steel structures digital fabrication composites

An Improved Evolvable Oscillator and Basis Function Set for control of an Insect-Scale Flapping-Wing Micro Air Vehicle

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Journal of computer Science & Technology 2012年第5期27卷 966-978页

作者： john c.Gallagher Michael W.Oppenheimer Department of computer Science and Engineering Wright State University control Sciences Branch Air Force Research Laboratory

This paper introduces an improved evolvable and adaptive hardware oscillator design capable of supporting adaptation intended to restore control precision in damaged or imperfectly manufactured insect-scale flapping-wing micro air vehicles. It will also present preliminary experimental results demonstrating that previously used basis function sets may have been too large and that significantly improved learning times may be achieved by judiciously culling the oscillator search space. The paper will conclude with a discussion of the application of this adaptive, evolvable oscillator to full vehicle control as well as the consideration of longer term goals and requirements.

关键词： evolvable and adaptive hardware micro air vehicle evolutionary algorithm

Two decades of variable retention in British columbia: a review of its implementation and effectiveness for biodiversity conservation

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Ecological Processes 2019年第1期8卷 402-423页

作者： William J.Beese john Deal B.Glen Dunsworth Stephen J.mitchell Timothy J.Philpott Vancouver Island University 900 Fifth StreetNanaimoBC V9R 5S5Canada Western Forest Products 118–1334 Island Hwy.Campbell RiverBC V9W 8C9Canada Glen Dunsworth Ecological consulting 7857 Shangri-La Rd.LantzvilleBC V0R 2H0Canada University of British columbia 2424 Main MallVancouverBC V6T 1Z4Canada Bc Min.of Forests Lands and Nat.Res.Oper400–640 Borland St.Williams LakeBC V2G 4T1Canada

Stand-level retention is an important component of sustainable forest management which aims to balance ecological,social and economic ***-term retention of mature forest structures at the time of harvesting(variable retention)is intended to produce future forest stands that more closely resemble conditions that develop after natural disturbances,thereby maintaining greater diversity of habitats for a variety of *** includes features such as live and dead trees representing multiple canopy layers,undisturbed understory vegetation and coarse woody *** the past two decades,variable retention has become common on forest lands in the temperate rainforests of coastal British columbia(Bc)and has been applied to a lesser extent in inland forest *** review of studies in Bc and in similar forest types in our region indicates that both aggregated and dispersed retention can contribute to biodiversity conservation by providing short-term‘life-boating’habitat for some species and by enhancing the structural characteristics of future *** example,greater abundance of species present in the pre-harvest forest have been documented for vegetation,birds,carabid beetles,gastropods,ectomycorrhizal fungi and soil fauna in retention cutblocks compared to *** are,however,some negative consequences for timber production such as wind damage to retained trees and reduced growth rates of tree regeneration compared to *** authors suggest an adaptive management approach for balancing competing objectives when faced with *** includes monitoring the implementation and effectiveness of various strategies for achieving *** two decades of experience applying variable retention harvesting to industrial-scale management of forest lands in Bc suggests that it is possible to balance production of wood with biodiversity conservation.

关键词： Alternative silvicultural systems clearcutting Biological legacies Forest biodiversity Old-growth Variable retention British columbia

An electrochemical process that uses an Fe^0/TiO2 cathode to degrade typical dyes and antibiotics and a bio-anode that produces electricity

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Frontiers of Environmental Science & Engineering 2016年第4期10卷 25-32页

作者： chaojie Jiang Lifen Liu john c. crittenden Key Laboratory of Industrial Ecology and Environmental Engineering (Ministry of Education) School of Environmental Science and Technology Dalian University of Technology Dalian 116024 China School of civil and Environmental Engineering Georgia Institute of Technology Atlanta GA 30332 USA

In this study a new water treatment system that couples （photo-） electrochemical catalysis （PEc or Ec） in a microbial fuel cell （MFc） was configured using a stainless-steel （SS） cathode coated w th Fe / TiO2. We examined the destruction of methylene blue （MB） and tetracycline. Fe^0/TiO2 was prepared using a chemical reduction-deposition method and coated onto an SS wire mesh （500 mesh） using a sol technique. The anode generates electricity using microbes （bio-anode）. connected via wire and ohmic resistance, the system requires a short reaction time and operates at a low cost by effectively remowng 94% MB （initial concentration 20 mg·L^-1） and 83% TOc/TOco under visible light illumination （50 W; 1.99 mW·cm^-2 for 120 rain, MFc-PEc）. The removal was similar even without light irradiation （MFc-Ec）. The EEo of the MFc-PEc system was approximately 0.675 kWh·m^-3. order-l whereas that of the MFc-Ec system was zero. The system was able to remove 70% cOD in tetracycline solution （initial tetracycline concentration 100 mg·L^-1） after 120 min of visible light illumination; without light, the removal was 15% lower. The destruction of MB and tetracycline in both traditional photocatalysis and photoelectrocatalysis systems was notably low. The electron spinresonance spectroscopy （ESR） study demonstrated that. OH was formed under visible light, and. 02 was formed without light. The bio-electricity-activated O2 and ROS （reactive oxidizing species） generation by Fe^0/TiO2 effectively degraded the pollutants. This cathodic degradation improved the electricity generation by accepting and consuming more electrons from the bio-anode.

关键词： Bio-anodePhotocatalytic cathode Fe^0/TiO2 ESRDye and antibioticsAdvanced oxidation