bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recalibration and merging of SSU observations for stratospheric temperature trend studies
Authors: Zou Cheng‐Zhi , Qian Haifeng , Wang Wenhui , Wang Likun , Long Craig 
Published: November 2014

AbstractLong‐term observations from the Stratospheric Sounding Unit (SSU) during 1979–2006 onboard NOAA historical polar orbiting satellites were recalibrated for climate change investigation. A two‐point linear calibration equation, with cold space and an internal blackbody warm target as end‐point references, was used to transfer SSU raw counts data into radiances. The warm target temperature was represented by measurements from the space side thermistor on the blackbody, and the cold space radiance was assumed to be zero. Space view corrections due to an electrical interference were applied. Intersatellite calibration was conducted simultaneously by applying calibration offsets determined from residual intersatellite biases. The recalibration reached an accuracy of 0.1–0.2 K for global means and thus is expected to improve the consistency in stratospheric temperature time series in climate reanalyses. The recalibrated SSU radiances were further adjusted to develop Version 2 of the NOAA stratospheric temperature time series. The effects being adjusted included those from changes in instrument cell pressure and atmospheric carbon dioxide concentration, viewing angle differences, and semidiurnal tides due to orbital drift. Intersatellite biases were carefully removed to ensure smooth transitions between satellite pairs. Differences from Version 1 included improved radiance calibration, improved adjusting schemes for diurnal drift and intersatellite biases, removal of time‐varying cell pressure adjustment for NOAA‐9 channel 1, and excluding NOAA‐7 channel 2 in the time series. In addition to the final merged data set, intermediate synthetic time series corresponding to different adjustments were also created to quantify their impact on the final trend as well as its reliability and uncertainty. Excellent matching between satellite pairs, especially the 7 year overlaps between NOAA‐11 and NOAA‐14 during 1997–2004, in intermediate as well as the final time series provided strong evidence on the validity of adjustments and thus confidence on the resulting trends. The Version 2 global mean trends for 1979–2006 were −0.69 ± 0.18, −0.77 ± 0.15, and −0.85 ± 0.15 K/decade for SSU channels 1, 2, and 3, representing temperatures of middle stratosphere, upper stratosphere, and stratosphere‐mesosphere, respectively. Among these, cooling of channel 2 was stronger and channel 3 weaker than those in UK Met Office (UKMO) data by about 1 K during the entire SSU period from 1979 to 2006. Finally, the average of the channel 1 and channel 3 anomalies in Version 2 was close to channel 2 anomalies to within 0.2 K for the entire 1979–2006 period with identical trends. This feature was found consistent with chemistry‐climate model simulations.
Hygroscopic growth and cloud forming potential of Arctic aerosol based on observed chemical and physical characteristics (a 1 year study 2007–2008)
Authors: Silvergren S. , Wideqvist U. , Ström J. , Sjogren S. , Svenningsson B. 
Published: November 2014

AbstractAerosol particle samples were collected, and the particle size distribution was measured during 1 year at the Zeppelin station (474 m asl) on Svalbard. The chemical constituents, hygroscopicity, and cloud forming properties of the aerosol were analyzed. The aerosol contained mostly sulfate and nitrate during the summer, whereas from September to February the main components were sodium and chloride. The highest concentration (20%) of water‐soluble organic matter was sampled in December. The hygroscopic growth factors for the water‐soluble fraction were 1.56–2.01 at 90% relative humidity, peaking in October, when the measured supersaturations needed for cloud drop formation were also the lowest. Sea‐salt components showed a positive correlation with the cloud forming capability, whereas the organic content had no correlation. The hygroscopicity factors, or κ values, were determined in three ways for each month: (1) κH‐TDMA from measurements of the hygroscopic growth of particles produced from atomization of the filter extracts, (2) κCCNC from measurements of the critical supersaturation as a function of size for these particles, and (3) κchem was modeled based on the organic and inorganic composition of the filter samples. Using the measured particle size distributions and the critical activation diameters from the Cloud Condensation Nuclei Counter (CCNC) measurements, it was found that the number of CCN varied more with supersaturation during the summer months. The best agreement between all three κ values was in December and January. Comparisons with earlier studies do not suggest any trend in the Arctic aerosol seasonal variability over the last decade.
Synthesis of Trifluoromethanesulfanylbenzofulvenes via a Cascade Electrophilic Cyclization under Mild Conditions
Authors: Xiao Qing , Zhu Hui , Li Guangming , Chen Zhiyuan 
Published: November 2014

AbstractThe introduction of the (trifluoromethyl)thio moiety into organic molecules has aroused comprehensive interest recently. We describe herein an efficient and chemoselective synthesis of trifluoromethanesulfanylbenzofulvenes through BiCl3‐ or TsOH‐promoted cascade electrophilic cyclization reactions. The presence of the trifluoromethanesulfanyl cation (CF3S+) would facilitate the electrophilic ring closure and nucleophilic attack of chloride or TsOH. This reaction provides a concise method for the synthesis of chlorine‐ or tosyloxy‐substituted trifluoromethanesulfanylbenzofulvenes in good to excellent yields.magnified image
Highly chlorine and oily fouling tolerant membrane surface modifications by in situ polymerization of dopamine and poly (ethylene glycol) diacrylate for water treatment
Authors: Kim Hyo Won , Lee Hee Dae , Jang Seung Jin , Park Ho Bum 
Published: November 2014

ABSTRACTHere we show a simple hydrophilic‐membrane surface modification method using in situ polymerization of aqueous dopamine and poly(ethylene glycol) diacrylate (PEGDA) mixture to improve both oily fouling and chemical resistance of membranes for water treatment. Polydopamine (PD) induced from aqueous dopamine solution has been extensively studied for facile membrane surface modification but the PD layer is very susceptible to chemical attack (e.g., sodium hypochlorite [NaClO]). To overcome this disadvantage, in this study, crosslinked poly(ethylene glycol) (XLPEG) chains were successfully introduced with PD layer using PEGDA with a thermal free radical initiator. As a result, the XLPEG/PD‐coated membranes showed excellent chemical stability against chlorine attack as well as much improved oily fouling tolerant behavior, without any sacrifice of original water permeance, as compared with only PD‐coated membranes. This surface modification method will be readily used for many membranes for water treatment from flat sheet to hollow fiber membrane modules. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41661.
A revised branch‐and‐price algorithm for dial‐a‐ride problems with the consideration of time‐dependent travel cost
Authors: Hu Ta‐Yin , Chang Chin‐Ping 
Published: November 2014

SummaryDeveloping demand responsive transit systems are important with regard to meeting the travel needs for elderly people. Although Dial‐a‐ride Problems (DARP) have been discussed for several decades, most researchers have worked to develop algorithms with low computational cost under the minimal total travel costs, and fewer studies have considered how changes in travel time might affect the vehicle routes and service sequences. Ignoring such variations in travel time when design vehicle routes and schedules might lead to the production of inefficient vehicle routes, as well as incorrect actual vehicle arrival times at the related nodes. The purpose of this paper is to construct a DARP formulation with consideration of time‐dependent travel times and utilizes the traffic simulation software, DynaTAIWAN, to simulate the real traffic conditions in order to obtain the time‐dependent travel time matrices. The branch‐and‐price approach is introduced for the time‐dependent DARP and tested by examining the sub‐network of Kaohsiung City, Taiwan. The numerical results reveal that the length of the time window can significantly affect the vehicle routes and quantitative measurements. As the length of the time window increases, the objective value and the number of vehicles will reduce significantly. However, the CPU time, the average pickup delay time, the average delivery delay time and the average actual ride time (ART)/direct ride time (DRT) will increase significantly as the length of the time window increases. Designing the vehicle routes to reduce operating costs and satisfy the requirements of customers is a difficult task, and a trade‐off must be made between these goals. Copyright © 2014 John Wiley & Sons, Ltd.
Synthesis and Characterisation of Self‐Assembled and Self‐Adjuvanting Asymmetric Multi‐Epitope Lipopeptides of Ovalbumin
Authors: Eskandari Sharareh , Stephenson Rachel J. , Fuaad Abdullah Ahmad , Apte Simon H. , Doolan Denise L. , Toth Istvan 
Published: November 2014

AbstractDesigning a lipopeptide (LP) vaccine with a specific asymmetric arrangement of epitopes may result in an improved display of antigens, increasing host‐cell recognition and immunogenicity. This study aimed to synthesise and characterise the physicochemical properties of a library of asymmetric LP‐based vaccine candidates that contained multiple CD4+ and CD8+ T‐cell epitopes from the model protein antigen, ovalbumin. These fully synthetic vaccine candidates were prepared by microwave‐assisted solid phase peptide synthesis. The C12 or C16 lipoamino acids were coupled to the N or C terminus of the OVA CD4 peptide epitope. The OVA CD4 LPs and OVA CD8 peptide constructs were then conjugated using azide–alkyne Huisgen cycloaddition to give multivalent synthetic vaccines. Physiochemical characterisation of these vaccines showed a tendency to self‐assemble in aqueous media. Changes in lipid length and position induced self‐assembly with significant changes to their morphology and secondary structure as shown by transmission electron microscopy and circular dichroism.
Iridium‐Catalyzed Reductive Nitro‐Mannich Cyclization
Authors: Gregory Alex W. , Chambers Alan , Hawkins Alison , Jakubec Pavol , Dixon Darren J. 
Published: November 2014

AbstractA new chemoselective reductive nitro‐Mannich cyclization reaction sequence of nitroalkyl‐tethered lactams has been developed. Relying on the rapid and chemoselective iridium(I)‐catalyzed reduction of lactams to the corresponding enamine, subsequent nitro‐Mannich cyclization of tethered nitroalkyl functionality provides direct access to important alkaloid natural‐product‐like structures in yields up to 81 % and in diastereoselectivities that are typically good to excellent. An in‐depth understanding of the reaction mechanism has been gained through NMR studies and characterization of reaction intermediates. The new methodology has been applied to the total synthesis of (±)‐epi‐epiquinamide in four steps.
Room‐Temperature Synthesis of Cu2−xE (E=S, Se) Nanotubes with Hierarchical Architecture as High‐Performance Counter Electrodes of Quantum‐Dot‐Sensitized Solar Cells
Authors: Chen Xin Qi , Li Zhen , Bai Yang , Sun Qiao , Wang Lian Zhou , Dou Shi Xue 
Published: November 2014

AbstractCopper chalcogenide nanostructures (e.g. one‐ dimensional nanotubes) have been the focus of interest because of their unique properties and great potential in various applications. Their current fabrications mainly rely on high‐temperature or complicated processes. Here, with the assistance of theoretical prediction, we prepared Cu2−xE (E=S, Se) micro‐/nanotubes (NTs) with a hierarchical architecture by using copper nanowires (Cu NWs), stable sulfur and selenium powder as precursors at room temperature. The influence of reaction parameters (e.g. precursor ratio, ligands, ligand ratio, and reaction time) on the formation of nanotubes was comprehensively investigated. The resultant Cu2−xE (E=S, Se) NTs were used as counter electrodes (CE) of quantum‐dot‐sensitized solar cells (QDSSCs) to achieve a conversion efficiency (η) of 5.02 and 6.25 %, respectively, much higher than that of QDSSCs made with Au CE (η=2.94 %).
Reversible Multistimuli‐Response Fluorescent Switch Based on Tetraphenylethene–Spiropyran Molecules
Authors: Qi Qingkai , Qian Jingyu , Ma Suqian , Xu Bin , Zhang Sean Xiao‐An , Tian Wenjing 
Published: November 2014

AbstractTwo tetraphenylethene (TPE)‐functionalized spiropyran (SP) molecules with very similar structure were designed and synthesized. The two molecules exhibit aggregation‐induced emission (AIE) properties, as well as multistimuli‐responsive color‐changing properties, such as photochromism and acidchromism. The investigation of their different photochromic and acidchromic characteristics and dual‐response fluorescent switch during isomerization indicated that the different link position between TPE and SP will significantly affect the extended π‐conjugated system, resulting in completely different photochromic and acidchromic properties.
Investigation of the Enantioselectivity of Tetramethylammonium L‐hydroxyproline Ionic Liquid as a Novel Chiral Ligand in Ligand‐Exchange CE and Ligand‐Exchange MEKC
Authors: Liu Ruijuan , Du Yingxiang , Chen Jiaquan , Zhang Qi , Du Shuaijing , Feng Zijie 
Published: November 2014

AbstractChiral ionic liquids (ILs) have drawn more and more attention in separation science; however, only a few papers focused on the application of chiral ILs as chiral ligands in LE‐CE. In this article, a novel amino acid ionic liquid (AAIL), tetramethylammonium L‐hydroxyproline ([TMA][L‐OH‐Pro]), was first applied as a chiral ligand to evaluate its enantioselectivity towards several aromatic amino acids in ligand‐exchange capillary electrophoresis (LE‐CE) and ligand‐exchange micellar electrokinetic capillary chromatography (LE‐MEKC). In the LE‐CE system, excellent separations were achieved for tryptophan (Rs = 3.03) and 3, 4‐dihydroxyphenylalanine (DOPA) (Rs = 4.35). Several parameters affecting the enantioseparation were systematically investigated, including AAIL concentration, type and concentration of central metal ion, buffer pH, as well as applied voltage. The optimum separation was obtained with 60 mM AAIL containing 30 mM Cu (II) at pH 4.5. Additionally, an LE‐MEKC system was established to further study the enantioselectivity of [TMA][L‐OH‐Pro] towards selected analytes. As observed, the separations of the enantiomers of tryptophan, phenylalanine, and histidine were all improved compared to the LE‐CE system. The results indicated that the application of AAILs as chiral ligands is a promising method in chiral separation science. Chirality 27:58–63, 2015. © 2014 Wiley Periodicals, Inc.
New insights in the clockwork mechanism regulating lineage specification: Lessons from the Drosophila nervous system
Authors: Cattenoz Pierre B. , Giangrande Angela 
Published: November 2014

ABSTRACTBackground: Powerful transcription factors called fate determinants induce robust differentiation programs in multipotent cells and trigger lineage specification. These factors guarantee the differentiation of specific tissues/organs/cells at the right place and the right moment to form a fully functional organism. Fate determinants are activated by temporal, positional, epigenetic, and post‐transcriptional cues, hence integrating complex and dynamic developmental networks. In turn, they activate specific transcriptional/epigenetic programs that secure novel molecular landscapes. Results: In this review, we use the Drosophila Gcm glial determinant as a model to discuss the mechanisms that allow lineage specification in the nervous system. The dynamic regulation of Gcm via interlocked loops has recently emerged as a key event in the establishment of stable identity. Gcm induces gliogenesis while triggering its own extinction, thus preventing the appearance of metastable states and neoplastic processes. Conclusions: Using simple animal models that allow in vivo manipulations provides a key tool to disentangle the complex regulation of cell fate determinants. Developmental Dynamics 244:332–341, 2015. © 2014 Wiley Periodicals, Inc.
Connectivity cluster analysis for discovering discriminative subnetworks in schizophrenia
Authors: Atluri Gowtham , Steinbach Michael , Lim Kelvin O. , Kumar Vipin , MacDonald Angus 
Published: November 2014

AbstractIn this manuscript, we present connectivity cluster analysis (CoCA), a novel computational framework that takes advantage of structure of the brain networks to magnify reproducible signals and quash noise. Resting state functional Magnetic Resonance Imaging (fMRI) data that is used in estimating functional brain networks is often noisy, leading to reduced power and inconsistent findings across independent studies. There is a need for techniques that can unearth signals in noisy datasets, while addressing redundancy in the functional connections that are used for testing association. CoCA is a data driven approach that addresses the problems of redundancy and noise by first finding groups of region pairs that behave in a cohesive way across the subjects. These cohesive sets of functional connections are further tested for association with the disease. CoCA is applied in the context of patients with schizophrenia, a disorder characterized as a disconnectivity syndrome. Our results suggest that CoCA can find reproducible sets of functional connections that behave cohesively. Applying this technique, we found that the connectivity clusters joining thalamus to parietal, temporal, and visuoparietal regions are highly discriminative of schizophrenia patients as well as reproducible using retest data and replicable in an independent confirmatory sample. Hum Brain Mapp 36:756–767, 2015. © 2014 Wiley Periodicals, Inc.
Regional cerebellar volume and cognitive function from adolescence to late middle age
Authors: Bernard Jessica A. , Leopold Daniel R. , Calhoun Vince D. , Mittal Vijay A. 
Published: November 2014

AbstractCerebellar morphology and function have been implicated in a variety of developmental disorders, and in healthy aging. Although recent work has sought to characterize the relationships between volume and age in this structure during adolescence, young, and older adulthood, there have been no investigations of regional cerebellar volume from adolescence through late middle age. Middle age in particular has been largely understudied, and investigating this period of the lifespan may be especially important for our understanding of senescence. Understanding regional patterns of cerebellar volume with respect to age during this portion of the lifespan may provide important insight into healthy aging and cognitive function as well as pathology from adolescence into later life. We investigated regional cerebellar volume using a highly novel lobular segmentation approach in conjunction with a battery of cognitive tasks in a cross‐sectional sample of 123 individuals from 12 to 65 years old. Our results indicated that regional cerebellar volumes show different patterns with respect to age. In particular, the more posterior aspect of the neocerebellum follows a quadratic “inverse‐U” pattern while the vermis and anterior cerebellum follow logarithmic patterns. In addition, we quantified the relationships between age and a variety of cognitive assessments and found relationships between regional cerebellar volumes and performance. Finally, exploratory analyses of sex differences in the relationships between regional cerebellar volume, age, and cognition were investigated. Taken together, these results provide key insights into the development and aging of the human cerebellum, and its role in cognitive function across the lifespan. Hum Brain Mapp 36:1102–1120, 2015. © 2014 Wiley Periodicals, Inc.
Photoperiod is associated with hippocampal volume in a large community sample
Authors: Miller Megan A. , Leckie Regina L. , Donofry Shannon D. , Gianaros Peter J. , Erickson Kirk I. , Manuck Stephen B. , Roecklein Kathryn A. 
Published: November 2014

ABSTRACTAlthough animal research has demonstrated seasonal changes in hippocampal volume, reflecting seasonal neuroplasticity, seasonal differences in human hippocampal volume have yet to be documented. Hippocampal volume has also been linked to depressed mood, a seasonally varying phenotype. Therefore, we hypothesized that seasonal differences in day‐length (i.e., photoperiod) would predict differences in hippocampal volume, and that this association would be linked to low mood. Healthy participants aged 30–54 (M = 43; SD = 7.32) from the University of Pittsburgh Adult Health and Behavior II project (n = 404; 53% female) were scanned in a 3T MRI scanner. Hippocampal volumes were determined using an automated segmentation algorithm using FreeSurfer. A mediation model tested whether hippocampal volume mediated the relationship between photoperiod and mood. Secondary analyses included seasonally fluctuating variables (i.e., sleep and physical activity) which have been shown to influence hippocampal volume. Shorter photoperiods were significantly associated with higher BDI scores (R2 = 0.01, β = −0.12, P = 0.02) and smaller hippocampal volumes (R2 = 0.40, β = 0.08, P = 0.04). However, due to the lack of an association between hippocampal volume and Beck Depression Inventory scores in the current sample, the mediation hypothesis was not supported. This study is the first to demonstrate an association between season and hippocampal volume. These data offer preliminary evidence that human hippocampal plasticity could be associated with photoperiod and indicates a need for longitudinal studies. © 2014 Wiley Periodicals, Inc.