bluuebunny/crossref_metadata_2025_split huggingface dataset:
High sensitivity of gross primary production in the Rocky Mountains to summer rain
Authors: Berkelhammer M. , Stefanescu I. C. , Joiner J. , Anderson L. 
Published: March 2017

AbstractIn the catchments of the Rocky Mountains, peak snowpack is declining in response to warmer spring temperatures. To understand how this will influence terrestrial gross primary production (GPP), we compared precipitation data across the intermountain west with satellite retrievals of solar‐induced fluorescence (SIF), a proxy for GPP. Annual precipitation patterns explained most of the spatial and temporal variability of SIF, but the slope of the response was dependent on site to site differences in the proportion of snowpack to summer rain. We separated the response of SIF to different seasonal precipitation amounts and found that SIF was approximately twice as sensitive to variations in summer rain than snowpack. The response of peak GPP to a secular decline in snowpack will likely be subtle, whereas a change in summer rain amount will have precipitous effects on GPP. The study suggests that the rain use efficiency of Rocky Mountain ecosystems is strongly dependent on precipitation form and timing.
High‐frequency radar ground clutter spatial correlation analysis: Transverse ionospheric drift velocity
Authors: Theurer Timothy E. , Bristow William A. 
Published: March 2017

AbstractA method of evaluating transverse ionospheric winds from oblique high‐frequency radar ground scatter is presented. Measurements of the two‐point, two‐time mutual coherence function (MCF) of ground clutter targets made by the Kodiak Super Dual Auroral Radar Network (SuperDARN) HF‐phased array radar illustrate that the spatial distribution of the backscattered electric field moves coherently across the radar aperture over time. Diffraction theory is applied to illustrate that the observations are consistent with an ionospheric drift transverse to the look direction of the radar. A general theoretical expression for the MCF is derived whose amplitude contours in the space‐time plane may be simply related to the azimuth angular spectrum and Doppler spectrum of the incident signal and a transverse ionospheric drift between the radar and the illuminated area. A method of estimating ionospheric drift from the observed MCF is developed and applied to observations made by the Kodiak SuperDARN radar.
Cosmic ray modulation and radiation dose of aircrews during the solar cycle 24/25
Authors: Miyake Shoko , Kataoka Ryuho , Sato Tatsuhiko 
Published: March 2017

AbstractWeak solar activity and high cosmic ray flux during the coming solar cycle are qualitatively anticipated by the recent observations that show the decline in the solar activity levels. We predict the cosmic ray modulation and resultant radiation exposure at flight altitude by using the time‐dependent and three‐dimensional model of the cosmic ray modulation. Our galactic cosmic ray (GCR) model is based on the variations of the solar wind speed, the strength of the heliospheric magnetic field, and the tilt angle of the heliospheric current sheet. We reproduce the 22 year variation of the cosmic ray modulation from 1980 to 2015 taking into account the gradient‐curvature drift motion of GCRs. The energy spectra of GCR protons obtained by our model show good agreement with the observations by the Balloon‐borne Experiment with a Superconducting magnetic rigidity Spectrometer (BESS) and the Payload for Antimatter Matter Exploration and Light‐nuclei Astrophysics (PAMELA) except for a discrepancy at the solar maximum. Five‐year annual radiation dose around the solar minimum at the solar cycle 24/25 will be approximately 19% higher than that in the last cycle. This is caused by the charge sign dependence of the cosmic ray modulation, such as the flattop profiles in a positive polarity.
Noncapillary Electrophoresis
Authors: Li Youxin , Jia Feifei , Xu Ran , Wang Dandan 
Published: March 2017

AbstractCapillary electrophoresis (CE) is being widely applied in pharmaceutical, biological, food, chemical, environmental, and clinical fields owing to its high efficiency, universality, sensitivity, trace consumption of sample, high sample throughput, and variety of operating modes. However, it is also facing great challenges in determination and analysis of ultratrace samples, semipreparation or preparation of samples, multidimensional analysis, and coupling of multiple technologies. Load capacity is a key factor that affects the solution of these issues. It is thought that the direct increase in capillary diameter is a shortcut. Many papers and patents reported the development of various electrophoresis methods in large capillaries (>150 µm), which are uniformly named wide‐bore electrophoresis (WBE) here. This article describes the progress in WBE, including the theory, methods, applications, and so on.
Monolithic High‐Performance Liquid Chromatography Columns
Authors: Desire Christopher T. , Hilder Emily F. , Arrua R. Dario 
Published: March 2017

AbstractMonolithic HPLC (high‐performance liquid chromatography) columns have emerged over the recent decades as highly attractive alternatives to conventional HPLC technology. A monolith is considered to be a continuous piece of porous material. Two types of monolithic columns have been developed for liquid chromatography (LC) applications; they are polymer monoliths and silica monoliths, which differ based on their porous properties. Polymer monoliths consist solely of macropores (pores larger than 50 nm), while silica monoliths possess both macropores and mesopores (pores between 2 and 50 nm). Silica monoliths therefore possess higher surface areas than polymer monoliths and have mainly been utilied for the separation of small molecules, where excellent separation performance has been demonstrated. Polymer monoliths on the other hand have been shown to provide excellent separation performance for larger molecules, where the convective transport of these molecules is unhindered by the presence of mesopores.Polymer and silica monoliths can be prepared in a variety of ways, resulting in varied surface chemistries and flow properties, thus allowing their application in a wide range of chromatographic modes, including reversed‐phase (RP), ion‐exchange, hydrophilic interaction, and hydrophobic interaction chromatography (HIC), to name a few. This has allowed for the separation of a variety of analytes, from small molecules such as alkylbenzenes, to larger molecules such as peptides and proteins. They have also found application for the separation of DNA. In recent years, significant attention has been focused on improving and understanding the behavior of these materials and alternative synthetic routes for their preparation.
Time‐Resolved Spectroscopy: Instrumentation and Applications
Authors: Ariese Freek , Roy Khokan , Ravi Kumar Venkatraman , Sudeeksha Hanehalli Chandrashekhar , Kayal Surajit , Umapathy Siva 
Published: March 2017

AbstractLight–matter interaction may lead to three fundamental phenomena, viz. (i) absorption, (ii) emission, and (iii) scattering. Spectroscopic techniques based on these phenomena are used to characterize the materials of interest, not only stable compounds but also short‐lived species during molecular transformations. Determining the electronic and molecular structure of the transient species is crucial in order to understand various photochemical, physical, and biological processes of fundamental and technological importance. Identifying various redox species during photosynthesis, understanding the photoinduced charge transfer process in solar cells, unraveling the photochemistry of vision that involves photoisomerization of retinal, etc. require spectroscopic techniques that can resolve various transient species in time and were practically impossible until the advent of pulsed lasers.The absorption of a photon by a molecule may initiate a cascade of dynamic molecular events, namely vibrational relaxation (VR), solvation dynamics, internal conversion (IC), intersystem crossing (ISC), electron transfer, isomerization reactions, etc., which can occur at femtosecond (fs) to picosecond (ps) timescales. Bimolecular reaction dynamics in liquids, such as H‐atom abstraction reaction, are typically diffusion controlled and therefore can be observed at nanosecond (ns) timescales. Therefore, time‐dependent (time‐resolved) spectroscopy has been an exquisite tool to follow the molecular dynamics after an initial phototrigger.Apart from studying molecular dynamics, time resolution can also be used to distinguish conformers, isomers or enantiomers, or distinguish identical compounds in different environments. It can also be applied to suppress unwanted signals occurring at different timescales, for instance fluorescence suppression in Raman experiments, or selectively detect compounds deeper inside a sample.In this article, we first give an introduction to the fundamentals of time‐resolved electronic absorption, spontaneous excited‐state resonance Raman, and coherent Raman scattering and emission techniques, spanning the range from femtosecond to microsecond timescales. Important technical aspects of time‐resolved spectroscopic equipment are also discussed. We then present some examples of cis–trans isomerization, thermal equilibrium of the two lowest triplet states, H‐atom abstraction reactions, etc. and demonstrate the molecular dynamic events after an initial phototrigger by a comprehensive kinetic analysis of the peak position, width and intensity of the marker bands in the time‐resolved electronic absorption, and Raman and emission spectra.
Single‐Cell Label‐Free Profiling
Authors: Falcón‐Banchs Roberto , Sohn Lydia L. , Rivest Francois 
Published: March 2017

AbstractIn this article, various techniques used for label‐free single‐cell profiling are discussed. Single‐cell assays have gained much popularity because of their potential use in studying heterogeneity in cell populations related to biology and disease. Cellular properties such as morphology, surface markers, electrophysiology, and mechanical properties are discussed in relation to specific label‐free platforms. The techniques are presented by their operation method, and advantages and limitations are discussed.
Biomedical Application ofRaman andFT‐IRSpectroscopies: Label‐Free Imaging of Liver Insult
Authors: Kochan K. , Baranska Malgorzata , Maslak E. 
Published: March 2017

AbstractImaging via vibrational spectroscopy techniques (Raman, Fourier transform infrared spectroscopy, FT‐IR) combined with chemometric analysis is becoming increasingly popular in the field of biomedical research. This results from numerous advantages of FT‐IR and Raman spectroscopies for the study of biological samples and the potential of their application in the context of pathogenesis studies as well as diagnostic use. Each technique, owing to its specificity, has slightly different attributes, which affect the scope of its application (diagnostics vs pathogenesis, micro‐ vs macroscale, tissue vs cellular and subcellular level, etc.) as well as its limitations. Increased recognition of the usefulness of FT‐IR and Raman‐based chemical imaging is visible through the multitude of their applications for various biological samples and a variety of diseases. In this work, we present a review of the adaptation of both techniques for liver‐based research, associated with its most common disorders. We introduce the basics of both techniques with particular emphasis on their advantages and limitations in terms of applications in the field of biomedical research. As the number of successful adaptation of vibrational spectroscopy‐based techniques for biological samples is already tremendous, we focus only on the liver‐related research in the context of lifestyle diseases. The importance and prevalence of lifestyle diseases due to the development of civilization are continually growing. A close connection between liver and lifestyle diseases results from the multitude of liver functions, particularly in terms of metabolism. Lifestyle diseases are linked inseparably with impaired liver function through nonalcoholic fatty liver disease (NAFLD), which can subsequently develop into a multitude of other dysfunctions, including fibrosis, cirrhosis, and cancer.
Ground‐Based Aerosol Measurements
Authors: Herckes Pierre , Fraser Matthew P. , Solomon Paul A. 
Published: March 2017

AbstractThis article summarizes the collection methods and analytical approaches used for the analysis of time‐integrated samples (i.e. samples collected over a period of time and returned to the laboratory for analysis) and continuous methods (i.e. in‐field measurements) for the measurement of airborne particles. The collection method needs to be considered an integral part of the quantification process since how samples are collected can impact whether the results represent what is in the air or have been modified. Thus, the primary focus of this article is on measurement process, collection and analysis, with only a short description of the motivation for these measurements.
Radiocarbon Analysis for Biofuel Quantification in Fuel Blends
Authors: Culp Randy 
Published: March 2017

Abstract

Fuel blends, particularly those composed of a mixture of biobase and fossil sources, are comparatively new in the energy marketplace relative to pure fossil fuels such as gasoline or pure biobase fuels such as sugarcane‐derived ethanol. A developing market exists for these blends of biobase and fossil fuels and accompanying this is the need for accurate assessment of each source's contribution in the mixture. In the United States, the Energy Independence and Security Act of 2007 mandates that specific levels of renewable fuel be established by 2022. Currently, this requirement is met by the 10% ethanol, derived primarily from corn, which is added to most gasoline sold in the United States. This mandate requires that the accurate determination of this addition of renewable fuel be provided. The well‐developed technology of radiocarbon dating, measuring the abundance of the
14
C atoms in a material, can determine the source material based on the abundance or absence of
14
C, similar to but distinct from age determination in radiocarbon dating. Relative to other analytical techniques,
14
C determination is the only one able to unambiguously determine a fossil‐fuel‐derived product. The use of radiocarbon, as a determinant of a biobase product, stems from the natural occurrence of
14
C in plants as a result of
14
CO
2
uptake during photosynthesis along with the far more abundant stable isotopes of carbon
13
CO
2
and
12
CO
2
. Once harvested, the biobase source material such as corn or sugarcane will no longer take up
14
CO
2
and will retain the majority of the
14
C absorbed with only a minor loss through the continuous process of radioactive decay.
14
C has a half‐life of 5730 years, the time required to halve the
14
C content, and becomes undetectable, or indiscernible from background activity, after approximately 10 half‐lives or 57 000 years. Carbon‐containing materials older than this have no measurable
14
C activity and are considered fossil in origin. This is a far shorter time than is required for the maturation of petroleum hydrocarbons or other fossil fuels so they are in essence at or below background
14
C activity by the nature of their long‐term formation. This paper discusses the use of
14
C and stable isotope of carbon to determine the mixing of biobase and fossil fuel‐derived materials.
Analysis of Orphan and Difficult Herbicides and/or Pesticides
Authors: Raina‐Fulton Renata , Yang Liu 
Published: March 2017

AbstractThis article reviews the main chromatography/mass spectrometry methods for the analysis of four main categories of herbicides and related pesticides including cationic charged herbicides (quaternary ammonium (quat) herbicides), anionic charged herbicides or organophosphorus herbicides (glyphosate (GLYP) and glufosinate (GLUF)), sulfonylurea herbicides that utilize liquid chromatography‐positive ion electrospray ionization‐tandem mass spectrometry (LC‐ESI+‐MS/MS), and phenoxyacid herbicides that have optimal mass spectrometry (MS) sensitivity with liquid chromatography‐negative ion electrospray ionization‐tandem mass spectrometry (LC‐ESI−‐MS/MS). In addition, selective degradation products of these herbicides that have been analyzed by chromatography‐mass spectrometry methods will be reviewed. Selected pesticides that are frequently simultaneously analyzed in targeted class‐specific methods for these four chemical classes of herbicides will be further discussed. The focus of this review is on the chromatography‐mass spectrometric detection methods for these classes of herbicides with priority given to liquid chromatography (LC)‐tandem mass spectrometry methods. These methods apply to the analysis of herbicides in food and environmental samples although sample preparation or clean‐up requirements may vary. The review will provide an overview to users in the best currently available chromatography‐mass spectrometry methods for these targeted chemical classes with an approach to include a broad range of herbicides within the class for future diversity in method development.
Analytical Sampling from Industrial Processes
Authors: Waters Tony 
Published: March 2017

AbstractThis article introduces the important design characteristics of sampling systems for process analytical measurements. Design principles that are essential to the success of any process analyzer installation are discussed in full, and the consequences of neglecting those principles are highlighted. The application of sampling principles to homogeneous and heterogeneous process streams is considered in detail, as are the calibration and validation procedures, the maintenance concerns, and the necessary safety precautions. The article is not intended to be a comprehensive design manual or a tutorial. Copious references are provided to published literature and to textbooks that provide detailed explanations and design formulae.
Examining Relations between Aging, Life Story Chapters, and Well‐Being
Authors: Kirkegaard Thomsen Dorthe , Lind Majse , Pillemer David B. 
Published: March 2017

SummarySocio‐emotional selectivity theory holds that older age is associated with a sense of limited remaining time. We suggest that life story chapters may be involved in this experience. In this first study on the connection between socio‐emotional selectivity theory and chapters, we examined whether older age is associated with fewer, temporally less distant, and less positive future chapters. We also examined relations between chapters and subjective well‐being. Two samples (18–84 years) described past and future chapters and completed well‐being measures. Older age was associated with fewer, less temporally extended, and less positive future chapters. Less positive past chapters was most consistently related to lower subjective well‐being, but less positive future chapters also predicted lower subjective well‐being in some analyses. Copyright © 2017 John Wiley & Sons, Ltd.
East of the Andes: The genetic profile of the Peruvian Amazon populations
Authors: Di Corcia T. , Sanchez Mellado C. , Davila Francia T. J. , Ferri G. , Sarno S. , Luiselli D. , Rickards O. 
Published: March 2017

AbstractObjectivesAssuming that the differences between the Andes and the Amazon rainforest at environmental and historical levels have influenced the distribution patterns of genes, languages, and cultures, the maternal and paternal genetic reconstruction of the Peruvian Amazon populations was used to test the relationships within and between these two extreme environments.Materials and MethodsWe analyzed four Peruvian Amazon communities (Ashaninka, Huambisa, Cashibo, and Shipibo) for both Y chromosome (17 STRs and 8 SNPs) and mtDNA data (control region sequences, two diagnostic sites of the coding region, and one INDEL), and we studied their variability against the rest of South America.ResultsWe detected a high degree of genetic diversity in the Peruvian Amazon people, both for mtDNA than for Y chromosome, excepting for Cashibo people, who seem to have had no exchanges with their neighbors, in contrast with the others communities. The genetic structure follows the divide between the Andes and the Amazon, but we found a certain degree of gene flow between these two environments, as particularly emerged with the Y chromosome descent cluster's (DCs) analysis.DiscussionThe Peruvian Amazon is home to an array of populations with differential rates of genetic exchanges with their neighbors and with the Andean people, depending on their peculiar demographic histories. We highlighted some successful Y chromosome lineages expansions originated in Peru during the pre‐Columbian history which involved both Andeans and Amazon Arawak people, showing that at least a part of the Amazon rainforest did not remain isolated from those exchanges.
Guanidine‐based polymeric microspheres with a nonleaching, antibacterial performance
Authors: Sun Xiaoxiao , Ji Junhui , Zhang Wei , Wang Gexia , Zhen Zhichao , Wang Pingli 
Published: March 2017

ABSTRACTPolyhexamethylene guanidine hydrochloride (PHGC) has excellent antibacterial activity, a low cytotoxicity, and wide applications. However, the high water solubility, poor compatibility, and retention of PHGC have constrained its applications in materials applied in water environments. In this study, suitable tailored polymer microspheres consisting of a hydrophobic poly(styrene‐co‐glycidyl methacrylate) (PSGMA) block and a hydrophilic block of PHGC were prepared with the two steps of emulsifier‐free copolymerization and a ring‐opening reaction. The product had a mean particle size of about 182.2 nm. The grafting efficiency of PHGC on PSGMA was affected by the reaction temperature and the PSGMA concentration. The microspheres had a nonleaching, antibacterial structure because of the chemical bond between PHGC and PSGMA. The sterilizing effect of the synthesized product was slightly affected by the grafting reaction, and it was analyzed by its emulsion of the minimal inhibitory concentration, which could kill 99.8% Staphylococcus aureus in 10 min. These microspheres could be a promising antibacterial material for application in water systems, such as in coatings, polymer commodities, and medical devices. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44821.
Synthesis and properties of sulfonated biphenyl poly(ether sulfone) and its mixed‐matrix membranes containing carbon nanotubes for gas separation
Authors: Zhao Nan , Liu Tao , Liu Zhongzhu , Su Yu , Yu Hongyang , Ma Jingjing , Yang Yanhua , Jiang Zhenhua 
Published: March 2017

ABSTRACTWe prepared mixed‐matrix membranes (MMMs) composed of carboxylated single‐walled carbon nanotubes (f‐SWCNTs) and a sulfonated biphenyl poly(ether sulfone) (S‐PPSU) polymer matrix. The thermal stability and properties of the pores of the S‐PPSU and f‐SWCNTs were characterized by thermogravimetric analysis and sorption isotherm curves, respectively; these showed that the surface and pore diameter decreased after the introduction of carboxyl groups to the single‐walled carbon nanotubes (SWCNTs), and the pore properties did not restore original values even when the f‐SWCNTs were preheated to 350 °C to remove carboxyl groups. The gas‐separation measurement showed that the MMMs comprised of the S‐PPSU and f‐SWCNTs possessed better gas‐separation properties than the ones composed of biphenyl poly(ether sulfone) and SWCNTs. The permeability for N2, O2, He, and CO2 and the selectivity for O2/N2 and O2/CO2 were enhanced simultaneously because of the good dispersion of f‐SWCNTs and the improved interaction between the two phases. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44995.