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Syzygium aromaticum L.(Clove)Essential Oil as a Reducing Agent for the Green Synthesis of Silver Nanoparticles

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Open Journal of Applied Sciences 2019年第2期9卷 45-54页

作者： Matheus Vinicius de Oliveira Brisola Maciel Aline da Rosa Almeida michelle heck Machado Ana Paula Zapelini de Melo Cleonice Goncalves da Rosa Daniele Ziglia de Freitas Carolina Montanheiro Noronha Gerson Lopes Teixeira Rafael Dutra de Armas Pedro Luiz Manique Barreto Departamento de Ciencia e Tecnologia de Alimentos Universidade Federal de Santa CatarinaFlorianopolisBrasil Centro Universitario-Catolica de Santa Catarina JoinvilleBrasil

The present investigation details a green synthesis of silver nanoparticles (AgNP) using the essential oil of Syzygium aromaticum L. (clove) as reducing agent, which is a matrix with a high content of eugenol, an important compound for the reducing action of silver nitrate. The synthesis of AgNP was performed at different pH conditions (pH 7, 8, 9 and 10), and was monitored by UV-Vis Spectroscopy, Dynamic Light Scattering (DLS) and Transmission Electron Microscopy. The synthesized nanoparticles presented characteristic Surface Plasmon Resonance bands with maximum absorbance between 405 and 460 nm. The DLS analysis revealed particle sizes from 31 to 72 nm and zeta potential between -30.1 and -50.8 mV indicating good stability against the agglomeration of the particles in solution. The micrographs obtained by TEM showed different particle shapes and a predominance of spherical-shaped nanoparticles, and average size ranging from 27 to 94 nm. The clove-based silver nanoparticles were efficient in controlling the growth of Escherichia coli and Staphylococcus aureus bacteria, and the minimum inhibitory concentration ranged from 60 to 100 μL/mL. This study highlights the feasibility of clove essential oil as an alternative for the synthesis of silver nanoparticles by a simple, inexpensive and eco-friendly method.

关键词： Essential Oil Clove Eugenol Silver Nanoparticles Antibacterial Activity

STABILIZATION, REFORMATION AND MELTING OF POLY(L-LACTIDE) CRYSTALLITES

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Chinese Journal of Polymer Science 2007年第1期25卷 83-94页

作者： Tai-Yon Cho Barbara heck Gert Strobl Physikalisches Institut Albert-Ludwigs-Universitt Freiburg 79104 FreiburgGermany

The large size of the crystallites in poly（L-lactide） and the low growth rate enable detailed time- and temperaturedependent X-ray scattering studies of the ordering processes to be carded out. A layer located intermediate between crystals and melt-like regions is observed which finally takes on crystalline order. Recrystallization processes during heating change the complete stack structure rather than the crystallites individually and produce voids in the stacks, Establishment of a new stable structure after a temperature jump in the melting range can be followed in time. DSC experiments indicate times of melting of the order of minutes.

关键词： Poly(L-lactide) Polymer crystallization Small angle X-ray scattering Semicrystalline structure.

Is Compositionality a Trivial Principle？

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Frontiers of Philosophy in China 2013年第1期8卷 140-155页

作者： Richard G. heck, Jr. Department of Philosophy Brown University Providence RI 02912 USA

Primarily a response to Paul Horwich＇s ＂Composition of Meanings,＂ this paper attempts to refute his claim that compositionality--roughly, the idea that the meaning of a sentence is determined by the meanings of its parts and how they are there combined--imposes no substantial constraints on semantic theory or on our conception of the meanings of words or sentences.

关键词： compositionality Horwich meaning semantics

Object-Based Method Outperforms Per-Pixel Method for Land Cover Classification in a Protected Area of the Brazilian Atlantic Rainforest Region

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Pedosphere 2013年第3期23卷 290-297页

作者： T.RITTL M.COOPER R.J.heck M.V.R.BALLESTER Department of Soil Quality University of Wageningen Department of Soil Science University of So Paulo School of Environmental Sciences University of Guelph Center for Nuclear Energy in Agriculture (CENA) University of So Paulo

Conventional image classification based on pixels hinders the possibilities to obtain information contained in images, while modern object-based classification methods increase the acquisition of information about the object and the context in which it is inserted in the image. The objective of this study was to investigate the performance of different classification methods for land cover mapping in the vicinity of the Alto Ribeira Tourist State Park, a Brazilian Atlantic rainforest area. Two classification methods were tested, including i） a hybrid per-pixel classification using the image processing software ERDAS Imagine version 9.1 and ii） an object-based classification using the software eCognition version 5. In the first method, six different classes were established, while in the second method, another two classes were established in addition to the six classes in the first method. Accuracy assessment of the classification results presented showed that the object-based classification with a Kappa index value of 0.8687 outperformed the per-pixel classification with a Kappa index value of 0.2224. Application of the user＇s knowledge during the object-based classification process achieved the desired quality; therefore, the use of inter-relationships between objects, superelasses, subclasses, and neighboring classes were critical to improving the efficiency of land cover classification.

关键词： accuracy assessment image classification Kappa index user's knowledge

Brain-derived neurotrophic factor rs6265(Val66Met)single nucleotide polymorphism as a master modifier of human pathophysiology

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Neural Regeneration Research 2023年第1期18卷 102-106页

作者： Van Thuan Nguyen Braxton Hill Naiya Sims Aaron heck Marcus Negron Claire Lusk Cristi LGalindo Department of Biology Western Kentucky UniversityBowling GreenKYUSA

Brain-derived neurotrophic factor is the most prevalent member of the nerve growth factor *** its discovery in 1978,this enigmatic molecule has spawned more than 27,000 publications,most of which are focused on neurological ***-derived neurotrophic factor is indispensable during embryogenesis and postnatally for the normal development and function of both the central and peripheral nervous *** is becoming increasingly clear,however,that brain-derived neurotrophic factor likewise plays crucial roles in a variety of other biological functions independently of sympathetic or parasympathetic ***-derived neurotrophic factor is also increasingly recognized as a sophisticated environmental sensor and master coordinator of whole organismal *** that point,we recently found that a common nonsynonymous(Val66→Met)single nucleotide polymorphism in the brain-derived neurotrophic factor gene(rs6265)not only substantially alters basal cardiac transcriptomics in mice but subtly influences heart gene expression and function differentially in males and *** addition to a short description of recent results from associative neuropsychiatric studies,this review provides an eclectic assortment of research reports that support a modulatory role for rs6265 including and beyond the central nervous system.

关键词： brain-derived neurotrophic factor neuropsychiatric disorders rs6265 Val66Met

Determining minimum sample size for the conditioned Latin hypercube sampling algorithm

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Pedosphere 2024年第3期34卷 530-539页

作者： Daniel D.SAURETTE Asim BISWAS Richard J.heck Adam W.GILLESPIE Aaron A.BERG School of Environmental Sciences University of Guelph50 Stone Rd EastGuelph ON N1G 2W1(Canada) Ontario Ministry of Agriculture Food and Rural Affairs1 Stone Rd WestGuelph ON N1G 2Y4(Canada) Geography Environment&GeomaticsUniversity of Guelph50 Stone Rd EastGuelph ON N1G 2W1(Canada)

In digital soil mapping(DSM),a fundamental assumption is that the spatial variability of the target variable can be explained by the predictors or environmental *** to adequately sample the predictors have been well documented,with the conditioned Latin hypercube sampling(cLHS)algorithm receiving the most attention in the DSM *** advances in sampling design,a critical gap remains in determining the number of samples required for DSM *** propose a simple workflow and function coded in R language to determine the minimum sample size for the cLHS algorithm based on histograms of the predictor variables using the Freedman-Diaconis rule for determining optimal bin *** preprocessing was included to correct for multimodal and non-normally distributed data,as these can affect sample size determination from the *** on a user-selected quantile range(QR)for the sample plan,the densities of the histogram bins at the upper and lower bounds of the QR were used as a scaling factor to determine minimum sample *** technique was applied to a field-scale set of environmental covariates for a well-sampled agricultural study site near Guelph,Ontario,Canada,and tested across a range of *** results showed increasing minimum sample size with an increase in the QR *** sample size increased from 44 to 83 when the QR increased from 50% to 95% and then increased exponentially to 194 for the 99%*** technique provides an estimate of minimum sample size that can be used as an input to the cLHS algorithm.

关键词： bin width digital soil mapping normal distribution quantile range sampling design

Graded doped structure fabricated by vacuum spray method to improve the luminance of polymer light-emitting diodes

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Nano-Micro Letters 2009年第1期1卷 19-22页

作者： X.Mo T.Mizokuro C.heck N.Tanigaki T.Hiraga Materials Science Department Fudan University Photonics Research Institute National Institute of Advanced Industrial Science and Technology

An increase in luminance of a polymer light-emitting diode(PLED) was obtained by fabricating a graded doping structure using a vacuum spray method. The small electron transport molecule, Tris(8-hydroxyquinolinato) aluminum(III)(Alq3), was graded dispersed along the film in the direction of growth in the hole transport polymer poly(3-hexylthiophene-2,5-diyl)(P3HT, regiorandom) layer of the PLED, despite being dissolved in the same organic solvent as the polymer. The PLED reported here, which is composed of a graded structure, emitted brighter light than PLEDs composed of pure polymer or of a blend of active layers prepared by spin coating and/or vacuum spray methods.

关键词： Polymer light-emitting diodes Luminance Graded doped Vacuum spray

Identification of common and distinct origins of human serum and breastmilk IgA1 by mass spectrometry-based clonal profiling

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Cellular & Molecular Immunology 2023年第1期20卷 26-37页

作者： Kelly A.Dingess Max Hoek Danique M.Hvan Rijswijk Sem Tamara Maurits Aden Boer Tim Veth Mirjam J.A.Damen Arjan Barendregt michelle Romijn Hannah G.Juncker Britt Jvan Keulen Gestur Vidarsson Johannes Bvan Goudoever Albert Bondt Albert J.R.heck Biomolecular Mass Spectrometry and Proteomics Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical SciencesUniversity of UtrechtPadualaan 8Utrecht 3584 CHThe Netherlands Netherlands Proteomics Center Padualaan 8Utrecht 3584 CHThe Netherlands Amsterdam UMC Vrije UniversiteitUniversity of AmsterdamEmma Children’s HospitalAmsterdam Reproduction&Development Research InstituteDepartment of PediatricsAmsterdamthe Netherlands Department of Experimental Immunohematology Sanquin Research and Landsteiner LaboratoryAmsterdam UMCUniversity of AmsterdamAmsterdamNetherlands

The most abundant immunoglobulin present in the human body is IgA. It has the highest concentrations at the mucosal lining and in biofluids such as milk and is the second most abundant class of antibodies in serum. We assessed the structural diversity and clonal repertoire of IgA1-containing molecular assemblies longitudinally in human serum and milk from three donors using a mass spectrometry-based approach. IgA-containing molecules purified from serum or milk were assessed by the release and subsequent analysis of their Fab fragments. Our data revealed that serum IgA1 consists of two distinct structural populations, namely monomeric IgA1 (∼80%) and dimeric joining (J-) chain coupled IgA1 (∼20%). Also, we confirmed that IgA1 in milk is present solely as secretory (S)IgA, consisting of two (∼50%), three (∼33%) or four (∼17%) IgA1 molecules assembled with a J-chain and secretory component (SC). Interestingly, the serum and milk IgA1-Fab repertoires were distinct between monomeric, and J-chain coupled dimeric IgA1. The serum dimeric J-chain coupled IgA1 repertoire contained several abundant clones also observed in the milk IgA1 repertoire. The latter repertoire had little to no overlap with the serum monomeric IgA1 repertoire. This suggests that human IgA1s have (at least) two distinct origins;one of these produces dimeric J-chain coupled IgA1 molecules, shared in human serum and milk, and another produces monomeric IgA1 ending up exclusively in serum.

关键词： Antigen binding fragment Immunoglobulin A1 Clonal repertoires human milk Serum

单个观测对平差结果的影响及异常观测值的寻找

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测绘译丛 1990年第2期 1-12页

作者： heck,B 万日银