bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development and validation of an experimental and theoretical method for the chiral discrimination of dinotefuran
Authors: Silva Camilla Fonseca , Guimarães Luciana , Borges Keyller Bastos , Nascimento Clebio Soares 
Published: November 2019

AbstractDinotefuran is a low‐cost agrochemical considered a highly toxic product. In this sense, there is a need for its constant environmental, biological, and food control, aiming to ensure its use to humans as well as to preserve biodiversity and ecosystems. In the present work, we developed an experimental and theoretical method for dinotefuran chiral discrimination. According to the main results, the dinotefuran enantioselective separation was efficiently optimized by high‐performance liquid chromatography evaluating the influence of different percentage compositions in the mobile phase to improve the resolution of the peaks in the chromatogram. The novelty of this work was the proposition of a reduced molecular model for the chiral selector amylose‐Tris‐(3,5‐dimethylphenylcarbamate) polysaccharide that was able to adequately describe at the molecular level its interaction with the dinotefuran enantiomers. Besides, the thermodynamic and structural parameters obtained via density functional theory calculations pointed out the chiral discrimination as well as the enantiomeric elution order of the analyte studied, confirming the experimental data, thus validating our proposed method. Finally, hydrogen bonds and repulsive interactions played a key role in the discrimination between the diastereomeric complexes, and consequently, for the dinotefuran enantioselective separation.
Investigation of the chiral recognition ability of human carboxylesterase 1 using indomethacin esters
Authors: Takahashi Masato , Takani Daisuke , Haba Masami , Hosokawa Masakiyo 
Published: November 2019

AbstractHuman carboxylesterase 1 (hCES1) is an enzyme that plays an important role in hydrolysis of pharmaceuticals in the human liver. In this study, elucidation of the chiral recognition ability of hCES1 was attempted using indomethacin esters in which various chiral alcohols were introduced. Indomethacin was condensed with various chiral alcohols to synthesize indomethacin esters. The synthesized esters were hydrolyzed with a human liver microsome (HLM) solution and a human intestine microsome (HIM) solution. High hydrolytic rate and high stereoselectivity were confirmed in the hydrolysis reaction in the HLM solution but not in the HIM solution, and these indomethacin esters were thought to be hydrolyzed by hCES1. Next, these indomethacin esters were hydrolyzed in recombinant hCES1 solution and the hydrolysis rates of the esters were calculated. The stereoselectivity confirmed in HLM solution was also confirmed in the hCES1 solution. In the hydrolysis reaction of esters in which a phenyl group is bonded next to the ester, the Vmax value of the (R) form was 10 times larger than that of the (S) form.
Clinical, cytologic, and immunohistochemical features of sarcomas involving body cavity fluids
Authors: Chen Athena L. , Janko Elizabeth , Pitman Martha B. , Chebib Ivan 
Published: November 2019

BackgroundSarcomas are uncommon findings in body cavity fluids. Diagnosis may be challenging because sarcoma cells in fluids can round up and lose their characteristic appearance seen on smears and histologic sections. This study characterizes the cytologic features of sarcomas involving body cavity fluids.MethodsEffusion fluids and cerebrospinal fluids diagnosed as positive for sarcoma were reviewed.ResultsForty‐three fluids from 28 patients (median age, 47 years) were positive for sarcoma. Four patients who presented with positive fluids were alive at 1 to 10.7 years' follow‐up (median, 22.5 months). Twenty‐four patients died 2 days to 2 years (median, 19 days) after their positive fluid diagnoses. Twenty‐eight specimens from 20 patients had slides available for review. Although 18 of the 28 positive fluids had a morphology comparable to that of their primary, 4 small round blue cell tumors (SRBCTs) and 4 spindle cell tumors showed epithelioid morphology, 1 SRBCT had pleomorphic morphology, and 1 epithelioid primary had SRBCT morphology. Nine fluids had tumor cells in large, cohesive clusters mimicking carcinoma; workup was performed for 10, predominantly to rule out carcinoma and mesothelioma.ConclusionsSarcoma morphology may be altered in exfoliated cytology specimens. Workup on cell blocks aids in the differential diagnosis, especially for carcinoma and mesothelioma. Unsurprisingly, fluid cytology positive for sarcoma portends poor survival.
Modeling the hepatic arterial flow in living liver donor after left hepatectomy and postoperative boundary condition exploration
Authors: Ma Renfei , Hunter Peter , Cousins Will , Ho Harvey , Bartlett Adam , Safaei Soroush 
Published: November 2019

AbstractPreoperative and postoperative hepatic perfusion is modeled with one‐dimensional (1‐D) Navier‐Stokes equations. Flow rates obtained from ultrasound (US) data and impedance resulted from structured trees are the inflow and outflow boundary condition (BC), respectively. Structured trees terminate at the size of the arterioles, which can enlarge their size after hepatectomy. In clinical studies, the resistance to pulsatile arterial flow caused by the microvascular bed can be reflected by the resistive index (RI), a frequently used index in assessing arterial resistance. This study uses the RI in a novel manner to conveniently obtain the postoperative outflow impedance from the preoperative impedance. The major emphasis of this study is to devise a model to capture the postoperative hepatic hemodynamics after left hepatectomy. To study this, we build a hepatic network model and analyze its behavior under four different outflow impedance: (a) the same as preoperative impedance; (b) evaluated using the RI and preoperative impedance; (c) computed from structured tree BC with increased radius of terminal vessels; and (d) evaluated using structured tree with both increased radius of root vessel, ie, the outlets of the postoperative hepatic artery, and increased radius of terminal vessels. Our results show that both impedance from (b) and (d) give a physiologically reasonable postoperative hepatic pressure range, while the RI in (b) allows for a fast approximation of postoperative impedance. Since hemodynamics after hepatectomy are not fully understood, the methods used in this study to explore postoperative outflow BC are informative for future models exploring hemodynamic effects of partial hepatectomy.
Population‐specific modelling of between/within‐subject flow variability in the carotid arteries of the elderly
Authors: Lassila Toni , Sarrami‐Foroushani Ali , Hejazi SeyedMostafa , Frangi Alejandro F. 
Published: November 2019

AbstractComputational fluid dynamics models are increasingly proposed for assisting the diagnosis and management of vascular diseases. Ideally, patient‐specific flow measurements are used to impose flow boundary conditions. When patient‐specific flow measurements are unavailable, mean values of flow measurements across small cohorts are used as normative values. In reality, both the between‐subjects and within‐subject flow variabilities are large. Consequently, neither one‐shot flow measurements nor mean values across a cohort are truly indicative of the flow regime in a given person. We develop models for both the between‐subjects and within‐subject variability of internal carotid flow. A log‐linear mixed effects model is combined with a Gaussian process to model the between‐subjects flow variability, while a lumped parameter model of cerebral autoregulation is used to model the within‐subject flow variability in response to heart rate and blood pressure changes. The model parameters are identified from carotid ultrasound measurements in a cohort of 103 elderly volunteers. We use the models to study intracranial aneurysm flow in 54 subjects under rest and exercise and conclude that OSI, a common wall shear‐stress derived quantity in vascular CFD studies, may be too sensitive to flow fluctuations to be a reliable biomarker.
Precise Control of Molecular Self‐Diffusion in Isoreticular and Multivariate Metal‐Organic Frameworks
Authors: Osborn Popp Thomas M. , Plantz Ariel Z. , Yaghi Omar M. , Reimer Jeffrey A. 
Published: November 2019

AbstractUnderstanding the factors that affect self‐diffusion in isoreticular and multivariate (MTV) MOFs is key to their application in drug delivery, separations, and heterogeneous catalysis. Here, we measure the apparent self‐diffusion of solvents saturated within the pores of large single crystals of MOF‐5, IRMOF‐3 (amino‐functionalized MOF‐5), and 17 MTV‐MOF‐5/IRMOF‐3 materials at various mole fractions. We find that the apparent self‐diffusion coefficient of N,N‐dimethylformamide (DMF) may be tuned linearly between the diffusion coefficients of MOF‐5 and IRMOF‐3 as a function of the linker mole fraction. We compare a series of solvents at saturation in MOF‐5 and IRMOF‐3 to elucidate the mechanism by which the linker amino groups tune molecular diffusion. The ratio of the self‐diffusion coefficients for solvents in MOF‐5 to those in IRMOF‐3 is similar across all solvents tested, regardless of solvent polarity. We conclude that average pore aperture, not solvent‐linker chemical interactions, is the primary factor responsible for the different diffusion dynamics upon introduction of an amino group to the linker.
A differentiation program induced by bone morphogenetic proteins 4 and 7 in endodermal epithelial cells provides the molecular basis for efficient nutrient transport by the chicken yolk sac
Authors: Bauer Raimund , Tondl Philipp , Schneider Wolfgang J. 
Published: November 2019

AbstractBackgroundThe mammalian yolk sac provides nutrients for the growing fetus during critical early developmental processes such as neural tube closure, which precedes the functional maturation of the placenta. In contrast, oviparous species such as the chicken rely solely on the yolk sac for transfer of nutrients from the yolk to the developing embryo. However, the molecular mechanisms that provide the yolk sac with nutrient transfer competence remain poorly understood.ResultsWe demonstrate that the chicken endodermal epithelial cells (EEC), which are in close contact with the yolk, gain their nutrient‐transport competence by a paracrine crosstalk with the blood‐vessel forming mesodermal cell layer. Bone morphogenetic proteins (BMP) 4 and 7 produced by ectodermal and mesodermal cell layers likely initiate a differentiation program of EECs during the transition from the area vitellina to the area vasculosa. BMPs, by inducing SMAD signaling, promote the up‐regulation of endocytic receptor expression and thereby provide the EECs with the molecular machinery to produce triglyceride‐rich lipoprotein particles.ConclusionThis paracrine signaling cascade may constitute the basis for the EEC‐mediated mechanism underlying the efficient uptake, degradation, resynthesis, and transfer of yolk‐derived nutrients into the embryonic circulation, which assures proper energy supply and development of the growing fetus.
Microsatellite‐based analysis of genetic structure and gene flow ofMythimna separata(Walker) (Lepidoptera: Noctuidae) in China
Authors: Li Mei‐Mei , Li Bo‐Liao , Jiang Shi‐Xiong , Zhao Yu‐Wan , Xu Xiang‐Li , Wu Jun‐Xiang 
Published: November 2019

AbstractThe oriental armyworm,Mythimna separata, is a serious agricultural pest in China. Seasonal and roundtrip migration has recently led to sudden, localized outbreaks and crop losses. To evaluate genetic differentiation between populations in eastern and western China and elucidate gene flow, the genetic structure of 20 natural populations from nine provinces was examined using seven microsatellite markers. The results indicated high genetic diversity. However, little to moderate (0 < FST < 0.15) genetic differentiation was detected, and there was no correlation between genetic distance and geographical distance. Bayesian clustering analysis identified three groups whereas discriminant analysis of principal components identified ten clusters that were considered as two clear‐cut clusters and one admixed group. Gene flow occurred frequently in most population pairs, and an asymmetrical migration rate was detected in several pairwise population comparisons. The bottleneck test showed that few populations had experienced recent bottlenecks. Correspondingly, large‐scale and long‐distance migration ofM. separatahas caused low genetic differentiation and frequent gene exchange. Our findings are important for studying genetic evolution and help to improve predictions ofM. separataoutbreaks in China.
External disturbances impact helminth–host interactions by affecting dynamics of infection, parasite traits, and host immune responses
Authors: Cattadori Isabella M. , Pathak Ashutosh K. , Ferrari Matthew J. 
Published: November 2019

AbstractExternal perturbations, such as multispecies infections or anthelmintic treatments, can alter host–parasite interactions with consequences on the dynamics of infection. While the overall profile of infection might appear fundamentally conserved at the host population level, perturbations can disproportionately affect components of parasite demography or host responses, and ultimately impact parasite fitness and long‐term persistence.We took an immuno‐epidemiological approach to this reasoning and examined a rabbit–helminth system where animals were trickle‐dosed with either one or two helminth species, treated halfway through the experiment with an anthelmintic and reinfected one month later following the same initial regime. Parasite traits (body length and fecundity) and host immune responses (cytokines, transcription factors, antibodies) were quantified at fixed time points and compared before and after drug treatment, and between single and dual infections.Findings indicated a resistant host phenotype toTrichostrongylus retortaeformiswhere abundance, body length, and fecundity were regulated by a protective immune response. In contrast,Graphidium strigosumaccumulated in the host and, while it stimulated a clear immune reaction, many genes were downregulated both following reinfection and in dual infection, suggestive of a low host resistance.External perturbations affected parasite fecundity, including body length and number of eggs in utero, more significantly than abundance; however, there was no consistency in the parasite‐immune relationships.Disentangling the processes affecting parasite life history, and how they relate to host responses, can provide a better understanding of how external disturbances impact disease severity and transmission, and how parasites strategies adjust to secure persistence at the host and the population level.
Resource selection of mule deer in a shrub‐steppe ecosystem: influence of woodland distribution and animal behavior
Authors: Morano Sabrina , Stewart Kelley M. , Dilts Thomas , Ellsworth Alisa , Bleich Vernon C. 
Published: November 2019

AbstractUngulates inhabiting arid ecosystems are reliant on productive forb and shrub communities during summer months to meet nutritional demands for survival and reproduction. In the western United States, expansion of woodland vegetation into shrub‐dominated communities and the potential loss of habitat are of concern with regard to animal populations reliant on robust sagebrush shrub and forb vegetation. We used mixed‐effects logistic regression to model resource selection of female mule deer (Odocoileus hemionus) during the summers of 2005–2008. We considered selection at two spatial scales, and during three daily activity periods (night, crepuscular, and mid‐day) corresponding to resting and foraging. We evaluated habitat variables related to vegetation type, site productivity, terrain attributes, and fine‐scale abundance of pinyon–juniper cover. Those attributes allowed us to account for variation in site productivity and animal behaviors that could obscure the true relationship between density of pinyon–juniper woodland and habitat use by mule deer. We detected observable differences in habitat use by mule deer among the three activity periods with significant differences in movement rates. Deer were most active during crepuscular periods corresponding with foraging activity, and least active mid‐day when temperatures were highest. Summer habitat consisted of sites with high potential productivity, greater shrub abundance, and greater proximity to riparian areas. Deer avoided high levels of tree cover (>40% coverage) at all spatial and temporal scales, and in general selection declined with increasing pinyon–juniper cover, particularly during foraging periods. Nonetheless, mule deer selected areas with low to intermediate tree cover (10% to 40%) during resting periods and avoided areas of productive shrub and forb vegetation and riparian areas, when surrounded by denser stands of pinyon–juniper cover. These results emphasize the importance of productive shrub and forb vegetation to mule deer inhabiting semi‐arid regions and suggest that low levels of tree cover are beneficial, especially during resting periods. Nevertheless, dense pinyon–juniper cover was generally avoided even in areas of high site productivity. These relationships lend support to the concern that increases in large, dense stands of pinyon–juniper reduce availability of summer habitat and alter patterns of resource selection for mule deer, a shrub‐dependent ungulate.
Web of interactions among diversity approaches to identify ecosystem essential variables: Negev Highlands case study
Authors: Dor‐Haim Shayli , Orenstein Daniel E. , Shachak Moshe 
Published: November 2019

AbstractThe concept of ecosystem diversity essential variables (EEVs) offers a foundation for ecosystem studies. Identification of EEVs continues to be a challenge in the field of ecology, due to the lack of a conceptual and applied framework. This paper develops a conceptual framework, offering theoretical foundation and a methodology for identifying EEVs, reflecting essential biodiversity and geodiversity variables. We start with a conceptual model of ecosystem essential variables linking biodiversity and geodiversity processes into ecosystem diversity as a web of interactions (WoI). The WoI components and interactions enable the identification of EEVs and their essentiality by relating interactions among diversities to variables that identify them. We tested our conceptual pass way by analyzing drivers and feedbacks of ecosystem processes in the Negev Highlands. Based on the general models and research of the Negev Highlands, we present four steps for EEVs: (1) developing a general conceptual model of the abiotic and biotic components of the ecosystem that links both biodiversity and geodiversity and their interactions; (2) testing the validity of the general model for a specific ecosystem to find out the hydro‐geo‐ecological drivers and feedbacks controlling ecosystem diversity; (3) constructing a WoI that adds to the regular analysis of an ecosystem as an interaction among geodiversity and biodiversity by breaking down the two components of diversities into subcomponent and their interactions; and (4) translating of the WoI components and interactions to EEVs. We suggest that EEVs should be related not only to the components but also to the interactions among diversities. These steps are essential for developing a scientific framework that allows for systematic identification of EEVs and justification regarding the final selection of the essential variables. We suggest that the approach can potentially be applied to all global terrestrial system.
Stream network geometry and the spatial influence of aquatic insect subsidies across the contiguous United States
Authors: Kopp Darin A. , Allen Daniel C. 
Published: November 2019

AbstractEmergent aquatic insects transport aquatic‐derived resources into terrestrial ecosystems but are rarely studied at landscape or regional scales. Here, we investigate how stream network geometry constrains the spatial influence of aquatic insect subsidies in terrestrial ecosystems. We also explore potential factors (i.e., climate, topography, soils, and vegetation) that could produce variation in stream network geometry and thus change the extent of aquatic insect subsidies from one region to another. The stream signature is the percentage of aquatic insect subsidies traveling a given distance into the terrestrial ecosystem, relative to what comes out of the stream. We use this concept to model the spatial extent (area) and distribution (spatial patterning) of aquatic subsidies in terrestrial ecosystems across the contiguous United States. Our findings suggest that at least 8% of the subsidies measured at the aquatic–terrestrial boundary (i.e., the 8% stream signature) are typically transferred throughout the entire watershed and that variation in this spatial extent is largely influenced by the drainage density of the stream network. Moreover, we found stream signatures from individual stream reaches overlap such that the spatial extent of the 8% stream signature often includes inputs from multiple stream reaches. Landscape‐scale stream network characteristics increased the area of overlapping stream signatures more than reach‐scale channel properties. Finally, we found runoff was an important factor influencing stream network geometry suggesting a potential effect of climate on aquatic‐to‐terrestrial linkages that have been understudied.
Analysis of particle deposition in a new‐type rectifying plate system during shale gas extraction
Authors: Peng Shanbi , Chen Qikun , Zheng Chao , Liu Enbin 
Published: November 2019

AbstractMuch less attention has been focused on the particle deposition in rectifying plate though it is a common problem in shale gas pipe systems. The effects of particle parameter and flow field on the deposition and distribution of particle in a new‐type rectifying plate system are investigated. Both the computational fluid dynamics (CFD) method and the experiment method are used in order to analyze the particle deposition under various conditions. The accuracy of simulation model is verified with measurements in the experiment and from analyzing, and it is found that the Boltzmann equation can well describe the relationship between gas Reynolds number and particle deposition in the rectifying plate system. It is also found from investigation that the particle deposition is greatly affected by the particle parameter. Deposition rate rises with the increase of the particle diameter; however, it reduces gradually with the decrease of particle shape factor. Moreover, the particle mass concentration is an essential dimension that can give a prediction of where the particle may deposit.