bluuebunny/crossref_metadata_2025_split huggingface dataset:
A micellar electrokinetic chromatography approach using diastereomeric derivatization and a volatile surfactant for the enantioselective separation of selenomethionine
Authors: Pérez‐Míguez Raquel , Marina Maria Luisa , Castro‐Puyana María 
Published: May 2019

AbstractA MEKC methodology with UV detection was developed for the enantioselective separation of selenomethionine (SeMet). The use of (+)‐1‐(9‐fluorenyl)ethyl chloroformate (FLEC) as chiral derivatization reagent to form SeMet diastereomers enabled their subsequent separation using ammonium perfluorooctanoate (APFO) as a volatile pseudostationary phase. The effect of APFO concentration and pH, temperature, injection volume, and derivatization conditions (time and FLEC/SeMet ratio) were evaluated in order to select the best separation conditions. A chiral resolution of 4.4 for DL‐SeMet was achieved in less than 6 min using 100 mM APFO at pH 8.5 as electrophoretic buffer. Satisfactory results were obtained in terms of linearity, precision (RSD from 3.4 to 5.1% for migration times and from 1.8 to 4.6% for corrected peak areas), accuracy, and LODs (3.1 × 10−6 M and 3.7 × 10−6 M for d and l enantiomers, respectively). The method was successfully applied to the determination of l‐SeMet in food supplements.
Model‐based clustering for noisy longitudinal circular data, with application to animal movement
Authors: Ranalli M. , Maruotti A. 
Published: May 2019

AbstractIn this work, we introduce a model for circular data analysis to robustly estimate parameters, under a longitudinal clustering setting. A hidden Markov model for longitudinal circular data combined with a uniform conditional density on the circle to capture noise observations is proposed. A set of exogenous covariates is available; they are assumed to affect the evolution of clustering over time. Parameter estimation is carried out through a hybrid expectation–maximization algorithm, using recursions widely adopted in the hidden Markov model literature. Examples of application of the proposal on real and simulated data are performed to show the effectiveness of the proposal.
Charging history and fluid evolution for the Carboniferous volcanic reservoirs in the western Chepaizi Uplift of Junggar Basin as determined by fluid inclusions and basin modelling
Authors: Shi Bingbing , Chang Xiangchun , Xu Youde , Mao Lixin , Zhang Jianhua , Li Yang 
Published: May 2019

Fluid inclusions are rich in the Carboniferous volcanic reservoirs in the western Chepaizi Uplift, occurring in liquid, gaseous, and gas–liquid phases. In this study, the fluid inclusions were investigated in terms of petrographic, optical, and microthermometric characteristics, coupled with pressure–volume–temperature–composition (PVTX) simulations. Two periods of hydrothermal activities in the Carboniferous volcanic reservoirs were suggested by the bimodal distributions of Th (homogenization temperatures) of fluid inclusions with 120–140°C and 160–190°C as the main peaks. The early charged fluids were characterized by a low temperature, low salinity, relatively higher density, and low G/L (gas–liquid volumetric ratio) of aqueous inclusions, whilst the late charged fluids featured a high temperature, moderate salinity, moderate density, and high G/L of aqueous inclusions. The oil inclusions hosted in calcite or quartz veins exhibited light yellow and yellowish‐green fluorescence, whereas those in the microcracks cutting or within quartz or calcite veins showed blue‐white fluorescence. The burial and geothermal histories imply an existence of abnormal hydrothermal activity under overpressure and high temperature, which is evidenced by the simulated trapping pressure that is higher than the lithostatic pressure and the measured Th values that are higher than the formation paleo‐temperatures. The Th range is widely and continuously distributed and, in combination with the burial history, indicates that the hydrocarbon accumulation in the research area has been a continuous process since the Paleogene. Combined with the reconstruction of tectonic evolution and hydrocarbon generation and expulsion, two oil‐charging episodes were defined, that is, the Late Oligocene–Early Miocene (23–16 Ma) and the Late Miocene–Holocene (6 Ma–). The western section of the Aika Fault Belt (F2), together with the sheet sandbodies of the Toutunhe Formation (J2t), and the unconformities between Carboniferous–Cretaceous may have served as the migration pathways.
Homocysteine, rather than age of onset, is a better predictor for cognitive function in older adults with bipolar disorder
Authors: Chen Pao‐Huan , Liu Hsing‐Cheng , Lu Mong‐Liang , Chen Chun‐Hsin , Chang Ching‐Jui , Chiu Wei‐Che , Sun I‐Wen , Liu Shen‐Ing , Tsai Shang‐Ying , Chiu Chih‐Chiang , Stewart Robert 
Published: May 2019

ObjectivesThe association between older‐age bipolar disorder and cognitive impairments may be mediated by vascular burden. The aim of the study was to examine the difference of cognitive function between older people with late‐onset bipolar disorder (LOBD) and early‐onset bipolar disorder (EOBD) by considering rigorous vascular risk burden evaluation, comprehensive cognitive tests, and relevant biochemistry data.MethodsWe recruited 95 outpatients aged over 55 with a DSM‐IV‐TR diagnosis of bipolar I disorder. Fifty had LOBD, defined by age of onset after 40. Cognitive function was evaluated through a battery of tests assessing verbal memory, attention/speed, visuospatial function, verbal fluency, and cognitive flexibility. Vascular risk assessments included individual disorders, 10‐year Framingham cardiovascular risk scores, and serum levels of homocysteine, vitamin B12, folate, and triiodothyronine.ResultsNo differences were observed between LOBD and EOBD on any cognitive test after adjusting for potential confounders. In addition to age and educational years, multiple linear regression analyses indicated significantly negative associations between serum homocysteine levels and cognitive performances in attention, psychomotor speed, verbal memory, and executive function.ConclusionsAmong older people with bipolar disorder, LOBD is not associated with more cognitive dysfunction in this study. However, higher serum homocysteine levels were significantly associated with worse cognitive performance in this particular group. Clinicians therefore have to pay attention to the cognitive function in older bipolar patients with higher levels of homocysteine.
Effects of the presence of probiotic bacteria in the aging medium on the surface roughness and chemical composition of two dental alloys
Authors: Musa Trolic Ines , Todoric Zrinka , Pop Acev Darko , Makreski Petre , Pejova Biljana , Spalj Stjepan 
Published: May 2019

AbstractThe aims of this study were: (a) to determine if the presence of probiotic bacteria in an aging medium, that is, artificial saliva in this study, has relevant effects on the surface roughness and the chemical composition of two main alloys used in dentistry (NiTi and stainless steel [SS]) and (b) in the case of NiTi, if these effects are influenced by the coating of the alloy (rhodium and titanium nitride). Atomic force microscopy and Raman spectroscopy were used to study the surface morphology and identify metal oxides formed on the surface of the alloys. Experiments demonstrated that the probiotic bacteria Lactobacillus reuteri can induce processes that alter some features of the surface such as roughness and chemical composition. The effect is dependent on the type of alloy and coating. The bacteria increased roughness in the case of uncoated NiTi more than saliva alone (pH = 4.8). Probiotic bacteria tend to decrease the corrosive influence of saliva on NiTi when the alloy is coated with rhodium or titanium nitride and this effect was also evidenced on SS. Raman spectroscopy confirmed that only SS samples are prone to oxidation processes, predominantly associated with exposure to saliva rather than probiotic bacteria.
Suboptimal geographic accessibility to comprehensive HIV care in the US: regional and urban–rural differences
Authors: Masiano Steven P , Martin Erika G , Bono Rose S , Dahman Bassam , Sabik Lindsay M , Belgrave Faye Z , Adimora Adaora A , Kimmel April D 
Published: May 2019

AbstractAchieving US state and municipal benchmarks to end the HIV epidemic and promote health equity requires access to comprehensive HIV care. However, this care may not be geographically accessible for all people living with HIV (PLHIV). We estimated county‐level drive time and suboptimal geographic accessibility to HIV care across the contiguous US, assessing regional and urban–rural differences. We integrated publicly available data from four federal databases to identify and geocode sites providing comprehensive HIV care in 2015, defined as the co‐located provision of core HIV medical care and support services. Leveraging street network, US Census and HIV surveillance data (2014), we used geographic analysis to estimate the fastest one‐way drive time between the population‐weighted county centroid and the nearest site providing HIV care for counties reporting at least five diagnosed HIV cases. We summarized HIV care sites, county‐level drive time, population‐weighted drive time and suboptimal geographic accessibility to HIV care, by US region and county rurality (2013). Geographic accessibility to HIV care was suboptimal if drive time was >30 min, a common threshold for primary care accessibility in the general US population. Tests of statistical significance were not performed, since the analysis is population‐based. We identified 671 HIV care sites across the US, with 95% in urban counties. Nationwide, the median county‐level drive time to HIV care is 69 min (interquartile range (IQR) 66 min). The median county‐level drive time to HIV care for rural counties (90 min, IQR 61) is over twice that of urban counties (40 min, IQR 48), with the greatest urban–rural differences in the West. Nationally, population‐weighted drive time, an approximation of individual‐level drive time, is over five times longer in rural counties than in urban counties. Geographic access to HIV care is suboptimal for over 170,000 people diagnosed with HIV (19%), with over half of these individuals from the South and disproportionately the rural South. Nationally, approximately 80,000 (9%) drive over an hour to receive HIV care. Suboptimal geographic accessibility to HIV care is an important structural barrier in the US, particularly for rural residents living with HIV in the South and West. Targeted policies and interventions to address this challenge should become a priority.
Hepatitis C risk perceptions and attitudes towards reinfection among HIV‐diagnosed gay and bisexual men in Melbourne, Australia
Authors: Schroeder Sophia E , Higgs Peter , Winter Rebecca , Brown Graham , Pedrana Alisa , Hellard Margaret , Doyle Joseph , Stoové Mark 
Published: May 2019

AbstractIntroductionGay and bisexual men (GBM) are at increased risk of hepatitis C/HIV co‐infection. In Australia, the availability of subsidized direct‐acting antiviral treatment for hepatitis C has rendered eliminating co‐infection possible. High reinfection rates in subgroups with continued exposure may compromise elimination efforts. To inform the development of hepatitis C risk reduction support in GBM, we explored reinfection risk perceptions and attitudes among GBM living with HIV recently cured from hepatitis C.MethodsBetween April and August 2017, 15 GBM living with diagnosed HIV were recruited from high caseload HIV primary care services in Melbourne following successful hepatitis C treatment. In‐depth interviews were conducted exploring understandings of hepatitis C risks, experiences of co‐infection and attitudes towards reinfection. Constructivist grounded theory guided data aggregation.ResultsParticipants’ understandings of their hepatitis C infection and reinfection trajectories were captured in three categories. Hepatitis C and HIV disease dichotomies: Hepatitis C diagnosis was a shock to most participants and contrasted with feelings of inevitability associated with HIV seroconversion. While HIV was normalized, hepatitis C was experienced as highly stigmatizing. Despite injecting drug use, interviewees did not identify with populations typically at risk of hepatitis C. Risk environments and avoiding reinfection: Interviewees identified their social and sexual networks as risk‐perpetuating environments where drug use was ubiquitous and higher risk sex was common. Avoiding these risk environments to avoid reinfection resulted in community disengagement, leaving many feeling socially isolated. Hepatitis C care as a catalyst for change: Engagement in hepatitis C care contributed to a better understanding of hepatitis C risks. Interviewees were committed to applying their improved competencies around transmission risk reduction to avoid reinfection. Interviewees also considered hepatitis C care as a catalyst to reduce their drug use.ConclusionsHepatitis C/HIV co‐infection among GBM cannot be understood in isolation from co‐occurring drug use and sex, nor as separate from their HIV infection. Hepatitis C prevention must address subcultural heterogeneity and the intersectionality between multiple stigmatized social identities. Hepatitis C care presents an opportunity to provide support beyond cure. Peer support networks could mitigate social capital loss following a commitment to behaviour change and reduce hepatitis C reinfection risks.
A novel trust‐region–based algorithm with flexible Jacobian updates for expedited optimization of high‐frequency structures
Authors: Pietrenko‐Dabrowska Anna 
Published: May 2019

AbstractSimulation‐driven design closure is mandatory in the design of contemporary high‐frequency components. It aims at improving the selected performance figures through adjustment of the structure's geometry (and/or material) parameters. The computational cost of this process when employing numerical optimization is often prohibitively high, which is a strong motivation for the development of more efficient methods. This is especially important in the case of complex and multiparameter structures. In the paper, an expedited trust‐region–based algorithm for electromagnetic (EM)‐driven design optimization of high‐frequency structures is proposed. The presented technique involves a flexible sensitivity update scheme depending on the relative design changes with respect to the trust‐region size, as well as a direction of the design relocation and its alignment with the coordinate system axes. This allows for performing finite‐differentiation–based sensitivity updates less frequently and, consequently, brings considerable computational savings. Numerical results obtained for an ultra‐wideband antenna and a microwave coupler demonstrate that the proposed algorithm outperforms the reference procedure in terms of the number of EM simulations necessary to arrive at the optimized solution (around 50%). At the same time, the design quality loss is minor.
Morphologic, intraoperative, and histologic risk factors for sinonasal inverted papilloma recurrence
Authors: Lee Jake J. , Roland Lauren T. , Licata Jordan J. , Orlowski Hilary L.P. , Jiramongkolchai Pawina , Piccirillo Jay F. , Kallogjeri Dorina , Klatt‐Cromwell Cristine N. , Chernock Rebecca D. , Schneider John S. 
Published: May 2019

ObjectiveSinonasal inverted papillomas (IP) are benign neoplasms with a propensity for local recurrence. Many risk factors are reported, with little consistency between studies. This study aimed to comprehensively assess for demographic, imaging, histopathologic, and intraoperative risk factors for recurrence.MethodsWe performed a single‐center retrospective cohort study of patients with pathologically diagnosed IP without malignancy who underwent surgical resection between 1997 and 2018. Eligible patients were identified through a database maintained by the Department of Pathology. Logistic regression identified variables associated with recurrence, and conjunctive consolidation was performed to create a predictive model.ResultsOf 76 subjects, 37% (n = 28) had recurrence. Median follow‐up and time to recurrence were 2.9 (range 0.5–21.1) and 1.7 (range 0.2–13.0) years, respectively. Confirmed negative margins on histology were protective (odds ratio [OR] 0.25, 95% confidence interval [CI] 0.08–0.85). Frontal sinus involvement (adjusted odds ratio [aOR] 5.83, 95% CI 1.20–28.37), incomplete resection (aOR 9.67, 95% CI 2.24–41.72), and presence of dysplasia (aOR 4.38, 95% CI 1.01–19.10) were significantly associated with recurrence on multivariable analysis. A three‐level composite recurrence risk staging system was created by consolidating the above three variables. The recurrence risks of composite stage I, II, and III disease were 20%, 38%, and 100%, respectively. No demographic, imaging, staging, or surgical approach variables were associated with recurrence.ConclusionFrontal sinus involvement, incomplete resection, and dysplasia were significant risk factors for IP recurrence, whereas confirmed negative margins were protective. Creation of a composite staging system using the above variables may allow for risk stratification and a patient‐specific approach to postoperative IP management.Level of Evidence3Laryngoscope, 130:590–596, 2020
The coral ecosphere: A unique coral reef habitat that fosters coral–microbial interactions
Authors: Weber Laura , Gonzalez‐Díaz Patricia , Armenteros Maickel , Apprill Amy 
Published: May 2019

AbstractScleractinian corals are bathed in a sea of planktonic and particle‐associated microorganisms. The metabolic products of corals influence the growth and composition of microorganisms, but interactions between corals and seawater microorganisms are underexplored. We conducted a field‐based survey to compare the biomass, diversity, composition, and functional capacity of microorganisms in small‐volume seawater samples collected adjacent to five coral species with seawater collected > 1 m away from the reef substrate on the same reefs. Seawater collected close to corals generally harbored copiotrophic‐type bacteria and its bacterial and archaeal composition was influenced by coral species as well as the local reef environment. Trends in picoplankton abundances were variable and either increased or decreased away from coral colonies based on coral species and picoplankton functional group. Genes characteristic of surface‐attached and potentially virulent microbial lifestyles were enriched in near‐coral seawater compared to reef seawater. There was a prominent association between the coral Porites astreoides and the coral symbiont Endozoicomonas, suggesting recruitment and/or shedding of these cells into the surrounding seawater. This evidence extends our understanding of potential species‐specific and reef site‐influenced microbial interactions that occur between corals and microorganisms within this near‐coral seawater environment that we propose to call the “coral ecosphere.” Microbial interactions that occur within the coral ecosphere could influence recruitment of coral‐associated microorganisms and facilitate the transfer of coral metabolites into the microbial food web, thus fostering reef biogeochemical cycling and a linkage between corals and the water column.
A geometric property in and its applications
Authors: Bachar M. , Khamsi M. A. , Mendez O. , Bounkhel M. 
Published: May 2019

AbstractIn this work, we initiate the study of the geometry of the variable exponent sequence space when . In 1931 Orlicz introduced the variable exponent sequence spaces while studying lacunary Fourier series. Since then, much progress has been made in the understanding of these spaces and of their continuous counterpart. In particular, it is well known that is uniformly convex if and only if the exponent is bounded away from 1 and infinity. The geometry of when either or remains largely ill‐understood. We state and prove a modular version of the geometric property of when , known as uniform convexity in every direction. We present specific applications to fixed point theory. In particular we obtain an analogue to the classical Kirk's fixed point theorem in when .
Submersions and curves of constant geodesic curvature
Authors: Godoy Molina M. , Grong E. , Markina I. 
Published: May 2019

AbstractConsidering Riemannian submersions, we find necessary and sufficient conditions for when sub‐Riemannian normal geodesics project to curves of constant first geodesic curvature or constant first and vanishing second geodesic curvature. We describe a canonical extension of the sub‐Riemannian metric and study geometric properties of the obtained Riemannian manifold. This work contains several examples illustrating the results.
Identification of a de novo FOXP1 mutation and incidental discovery of inherited genetic variants contributing to a case of autism spectrum disorder and epilepsy
Authors: Jay Kristy , Mitra Amit , Harding Taylor , Matthes David , Van Ness Brian 
Published: May 2019

AbstractBackgroundAutism spectrum disorder is commonly co‐diagnosed intellectual disability, language disorder, anxiety, and epilepsy, however, symptom management is difficult due to the complex genetic nature of ASD.MethodsWe present a next‐generation sequencing‐based case study with both de novo and inherited genetic variants and highlight the impact of structural variants on post‐translational regulation of protein expression. Since management of symptoms has classically been through pharmaceutical therapies, a pharmacogenomics screen was also utilized to determine possible drug/gene interactions.ResultsA de novo variant was identified within the FOXP1 3′ untranslated regulatory region using exome sequencing. Additionally, inherited variants that likely contribute to the current and potential future traits were identified within the COMT, SLC6A4, CYP2C19, and CYP2D6 genes.ConclusionThis study aims to elucidate how a collection of variant genotypes could potentially impact neural development resulting in a unique phenotype including ASD and epilepsy. Each gene's contribution to neural development is assessed, and the interplay of these genotypes is discussed. The results highlight the utility of exome sequencing in conjunction with pharmacogenomics screening when evaluating possible causes of and therapeutic treatments for ASD‐related symptoms.