bluuebunny/crossref_metadata_2025_split huggingface dataset:
The contributions of admixture and genetic drift to diversity among post‐contact populations in the Americas
Authors: Koehl Anthony J. , Long Jeffrey C. 
Published: October 2017

AbstractObjectiveWe present a model that partitions Nei's minimum genetic distance between admixed populations into components of admixture and genetic drift. We applied this model to 17 admixed populations in the Americas to examine how admixture and drift have contributed to the patterns of genetic diversity.Materials and MethodsWe analyzed 618 short tandem repeat loci in 949 individuals from 49 population samples. Thirty‐two samples serve as proxies for continental ancestors. Seventeen samples represent admixed populations: (4) African‐American and (13) Latin American. We partition genetic distance, and then calculate fixation indices and principal coordinates to interpret our results. A computer simulation confirms that our method correctly estimates drift and admixture components of genetic distance when the assumptions of the model are met.ResultsThe partition of genetic distance shows that both admixture and genetic drift contribute to patterns of genetic diversity. The admixture component of genetic distance provides evidence for two distinct axes of continental ancestry. However, the genetic distances show that ancestry contributes to only one axis of genetic differentiation. The genetic distances among the 13 Latin American populations in this analysis show contributions from both differences in ancestry and differences in genetic drift. By contrast, the genetic distances among the four African American populations in this analysis owe mostly to genetic drift because these groups have similar fractions of European and African ancestry.ConclusionThe genetic structure of admixed populations in the Americas reflects more than admixture. We show that the history of serial founder effects constrains the impact of admixture on allele frequencies to a single dimension. Genetic drift in the admixed populations imposed a new level of genetic structure onto that created by admixture.
Evaluation of patient nasal saline irrigation practices following endoscopic sinus surgery
Authors: Yoo Frederick , Ference Elisabeth H. , Kuan Edward C. , Lee Jivianne T. , Wang Marilene B. , Suh Jeffrey D. 
Published: October 2017

BackgroundFunctional endoscopic sinus surgery (FESS) is an effective treatment for chronic rhinosinusitis (CRS). Postoperative management strategies after FESS often vary from surgeon to surgeon. Recent data suggests that nasal saline irrigation following FESS is almost universally recommended; however, patient adherence has not been formally evaluated. The purpose of this study is to evaluate postoperative nasal irrigation practices and its effects on short‐term outcomes in post‐FESS patients.MethodsEighty‐two patients were followed prospectively following FESS at a tertiary‐academic medical institution for 3 postoperative visits. Patients were surveyed on their irrigation practices (start date, frequency, and volume per irrigation per side), and adherence to prescribed antibiotic and steroid regimens. At each visit, 22‐item Sino‐Nasal Outcome Test (SNOT‐22) questionnaires and endoscopic examinations were evaluated by the Lund‐Kennedy Endoscopy Score (LKES). Factors evaluated include: patient demographics (age, sex, ethnicity), preoperative Lund‐Mackay and SNOT‐22 scores, comorbidities, extent of procedure, and use of nasal packing and/or spacers.ResultsAdherence to irrigation instructions was 82.9%. Factors significantly associated with compliance with irrigation instructions included younger age (p = 0.0022), prior irrigation (p < 0.0001), revision surgery (p = 0.0014), and non‐native English language speaking (p = 0.0095). Patients were more likely to irrigate with larger volumes if they were younger (p = 0.0284), had prior irrigation (p < 0.0001), or had revision surgery (p = 0.0056).ConclusionMultiple factors are associated with patient compliance with nasal saline irrigation after FESS. Ethnic and cultural considerations, such as language barriers, should also be considered to improve outcomes. Identification of patients who may be noncompliant could potentially benefit from increased preoperative counseling to improve adherence rates.
Dexamethasone attenuates methacholine‐mediated aquaporin 5 downregulation in human nasal epithelial cells via suppression of NF‐κB activation
Authors: Chang Yung‐Lung , Jian Kai Ren , Lin Chun‐Shu , Wang Hsing‐Won , Liu Shao‐Cheng 
Published: October 2017

BackgroundCholinergic stimulation plays a major role in inflammatory airway diseases. However, its role in airway surface liquid homeostasis and aquaporin 5 (AQP5) regulation remains unclear. In this study we sought to determine the effects of methacholine and dexamethasone on AQP5 expression in human nasal epithelial cells (HNEpC).MethodsHNEpC were cultured with methacholine or dexamethasone at 4 concentrations in vitro. The subcellular distribution of AQP5 was explored using immunocytochemistry. The pharmacologic effects of methacholine and dexamethasone on the expression of the phosphorylation of cyclic adenosine monophosphate–responsive element binding protein (p‐CREB), AQP5, and nuclear factor‐kappaB (NF‐κB) were examined using Western blotting.ResultsAQP5 was found to be located in cell membrane and cytoplasm and present in every group without a statistically significant difference. Methacholine inhibited expression of AQP5 and p‐CREB in HNEpC, whereas dexamethasone increased these protein levels dose‐dependently in a statistically significant manner. In turn, HNEpC treated with methacholine and dexamethasone showed the same trends as those intervened separately with these 2 drugs. Moreover, dexamethasone had the ability to reverse the inhibitory effect of methacholine. Western blotting revealed that, after incubation with 10−4 mol/L methacholine, NF‐κB increased significantly, by 186.67%, compared with the untreated control group. Again, such an increase could be significantly reversed after dexamethasone treatment.ConclusionNF‐κB activation is important for inhibition of p‐CREB/AQP5 expression after methacholine intervention, and dexamethasone adjusts it to the opposite side. This observation could provide additional insight into the anti‐inflammatory effects of glucocorticoids that contribute to maintaining airway surface liquid and mucosal defense.
Einblicke in die duale Aktivität einer bifunktionalen Dehydratase‐Cyclase‐Domäne
Authors: Sung Kwang Hoon , Berkhan Gesche , Hollmann Tim , Wagner Lisa , Blankenfeldt Wulf , Hahn Frank 
Published: October 2017

AbstractSauerstoffheterocyclen sind verbreitete Strukturmotive in Polyketid‐Naturstoffen. Wir berichten über strukturelle und mechanistische Untersuchungen zu AmbDH3, einer Polyketidsynthase‐Domäne mit dualer Aktivität als Dehydratase (DH) und pyranbildende Cyclase in der Ambruticin‐Biosynthese. AmbDH3 ähnelt monofunktionalen DH‐Domänen und verwendet H51 und D215 zur Dehydratisierung. Durch Mutationsstudien und In‐vitro‐Experimente konnte V173 als entscheidende Aminosäure für die Cyclisierungsaktivität identifiziert werden. Vergleichbare Motive wurden zudem in der scheinbar monofunktionalen Domäne AmDH2 gefunden, welche zusätzlich eine unerwartete Cyclisierungsaktivität zeigte. Unsere Ergebnisse ebnen den Weg zur möglichen Entdeckung bisher verborgener Cyclasen in Biosynthesewegen. Sie ermöglichen zudem interessante Aussichten für die Entwicklung neuer Biokatalysatoren für die chemoenzymatische Synthese und die Herstellung pyranhaltiger Polyketide durch kombinatorische Biosynthese.
Isolation and Characterization of a Non‐Rigid Hexamethylbenzene–SO2+ Complex
Authors: Malischewski Moritz , Seppelt Konrad 
Published: October 2017

AbstractDuring our studies towards the preparation of the pentagonal‐pyramidal hexamethylbenzene dication C6(CH3)62+, we isolated the unprecedented dicationic species C6(CH3)6SO2+ (AsF6−)2 from the reaction of hexamethylbenzene with a mixture of anhydrous HF, AsF5, and liquid SO2. This compound can be understood as a complex of unknown SO2+ with hexamethylbenzene. Herein, we report on its synthesis, molecular structure, and spectroscopic characterization.
Iron promotion of V‐HMS mesoporous catalysts for ultra‐deep oxidative desulfurization
Authors: Liu Shuzhi , Zhao Fulin , Sun Hongping , Liu Xianjun , Cui Baochen 
Published: October 2017

Bimetallic Fe‐V‐HMS (HMS, hexagonal mesoporous silica) catalysts with various molar ratios of iron to vanadium were synthesized using a co‐synthesis method, and investigated for oxidative desulfurization of dibenzothiophene (DBT) using tert‐butyl hydroperoxide as an oxidant. The catalysts were characterized using X‐ray diffraction, temperature‐programmed desorption of ammonia, Fourier transform infrared spectroscopy and N2 physical adsorption–desorption techniques. The Fe‐V‐HMS catalyst with a 2:1 molar ratio of iron to vanadium exhibited the highest total acidity and the highest catalytic activity. DBT was almost completely oxidized to dibenzothiophenesulfone, a species with a higher polarity that could be subsequently adsorbed on the Fe‐V‐HMS, and therefore the Fe‐V‐HMS acts as both a catalyst and an adsorbent simultaneously. The desulfurization rate was 98.1%. A pseudo‐first‐order model was fitted to the experimental data, and the activation energy was found to be 38.79 kJ mol−1. The encouraging performance of Fe‐V‐HMS offers the prospect of the design of a one‐pot oxidative desulfurization process without needing extraction of sulfones from fuel oil with a chemical solvent.
Dual‐template crown ether‐functionalized hierarchical porous silica: Preparation and application for adsorption of energy metal lithium
Authors: Xu Xuechao , Qiu Fengxian , Yang Dongya , Zheng Xudong , Wang Yuanyuan , Pan Jianming , Zhang Tao , Xu Jicheng , Li Chunxiang 
Published: October 2017

Lithium is the lightest energy metal element on earth and it has applications in lithium batteries and nuclear fusion. With the development of high‐tech and widespread applications of lithium, the demand for lithium continues to increase. In this work, a hierarchical porous lithium adsorbent (2M12C4‐HPS) was synthesized from a precursor of hierarchical porous silica (HPS), the HPS being obtained via a dual‐template technique. The microstructure and morphology of 2M12C4‐HPS were characterized using scanning electron microscopy, transmission electron microscopy, X‐ray diffraction and nitrogen adsorption–desorption measurements. The obtained hierarchical porous 2M12C4‐HPS containing two kinds of pores with different sizes (peaking at about 2.01 and 7.82 nm) has a high specific surface area (1143.56 m2 g−1). Fourier transform infrared spectroscopy and thermogravimetric analysis were used to confirm the surface organic functional groups of 2M12C4‐HPS, indicating that the functional group 2‐methylol‐12‐crown‐4 (2M12C4) was grafted on HPS successfully. The lithium adsorption properties, kinetics and isotherms of 2M12C4‐HPS were investigated. The adsorption kinetics can be described by the pseudo‐second‐order kinetic model and the adsorption isotherms well fit the Langmuir isotherm equation. In addition, 2M12C4‐HPS exhibited excellent specificity towards Li+. And the maximum adsorption rate of 2M12C4‐HPS is up to about 94.34%. The obtained results indicate that 2M12C4‐HPS has a broad commercial application prospect for adsorption of lithium.
Maximum actuation strain for dissipative dielectric elastomers with simultaneous effect of prestretch and temperature
Authors: Deng Lei , He Zhicheng , Li Eric , Chen Shoue 
Published: October 2017

ABSTRACTA dielectric elastomer can generate giant deformation by the voltage actuation, but the deformation is often hindered by the electromechanical instability and “snap‐through deformation,” which may lead to electrical breakdown. In this study, for the first time, the mathematical model is established for dissipative dielectric elastomers in the dynamic model with simultaneous effect of prestretch and temperature in order to achieve maximum actuation strain. The deformation of the dissipative dielectric elastomer: VHB 4905/4910 is investigated for the two simple actuation methods: constant and ramping voltage actuation, respectively. The best combined conditions of voltage and prestretch to obtain a large deformation at different operating temperatures are studied in detail. Under the best combined conditions, the influences of three factors: voltage, prestretch, and temperature on the maximum actuation strain are analyzed. This study should offer a great help in the design of dielectric elastomer actuators, and give the guidance to the accomplishment of the large deformation of dissipative dielectric elastomer actuators. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45850.
Poly(dimethylsiloxane)‐toughened syntactic foams
Authors: Ullas A.V. , Kumar D. , Roy P. K. 
Published: October 2017

ABSTRACTThe potential of preformed elastomers as a toughening agent for epoxy–glass syntactic foam has been explored. Poly(dimethylsiloxane) microspheres were prepared by suspension polymerization. The microsphere dimensions could be varied from 58 to 255 µm by tuning the reaction parameters, particularly the stirring speed and feed concentration. Rheological studies indicated that the introduction of microballoons led to an increase in the viscosity of the resin, with the extent being proportional to the microballoon content. The zero shear viscosity increased from ∼103 mPa s at 30 °C to 105 mPa s as the microballoon loading was increased to 40%. Syntactic foams containing varying amounts of microballoons (40–60% v/v) were prepared, and an analogous set of toughened foams were also prepared, where a fraction of the microballoons was replaced with poly(dimethylsiloxane) microspheres (3–7%). The effect of increasing dimensions of the elastomeric microspheres on the mechanical properties was also studied. The improvement in properties was more pronounced when the microsphere size was equivalent to that of the constituent microballoons. An improvement of 40% and 185% in flexural strength and flexural toughness was observed upon the introduction of poly(dimethylsiloxane) microspheres of optimal dimensions (diameter ∼63 µm, 5% loading), without any undesirable increase in foam density. However, the compressive properties remained practically unaltered. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45882.
Visualization of hydrolysis in polylactide using near‐infrared hyperspectral imaging and chemometrics
Authors: Muroga Shun , Hikima Yuta , Ohshima Masahiro 
Published: October 2017

ABSTRACTThe hydrolysis of polylactide (PLA) occurs during melt processing, leading to product defects in, for example, appearance and mechanical properties. Hydrolyzed PLA products, whose mechanical properties were deteriorated, must be detected during processing to ensure the quality control of PLA products. In this study, near‐infrared (NIR) hyperspectral imaging was applied for evaluating the extent of hydrolysis. NIR spectra in the wavelength range from 1200 to 1600 nm were changed by (1) hydrolysis induced by molding and (2) crystallization induced by annealing. The changes in the NIR spectra mediated by these two factors were distinctly different but overlapping, leading to difficulty in evaluating PLA at only a single wavelength. Partial least squares regression was introduced for detecting the hydrolyzed PLA. NIR imaging combined with the constructed partial least square models clearly visualized the differences in the extent of hydrolysis in hydrolyzed PLA under varying degrees of crystallization. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45898.
Preparation of aerochitin‐TiO2 composite for efficient photocatalytic degradation of methylene blue
Authors: Dassanayake Rohan Suranga , Rajakaruna Erandathi , Abidi Noureddine 
Published: October 2017

ABSTRACTAn aerochitin–titania (TiO2) composite was successfully synthesized and characterized by Fourier transform infrared spectroscopy, X‐ray diffraction, thermogravimetric analysis, field emission scanning electron microscopy, and N2 adsorption isotherms. The photocatalytic activity of the composite was investigated on the degradation of the model organic pollutant, methylene blue (MB) dye, under UV irradiation. The aerochitin–TiO2 composite showed excellent adsorptive and photocatalytic activity with a degradation degree of 98% for MB. The first‐order rate constants for the photodegradation MB by TiO2 nanoparticles and aerochitin–TiO2 composite were found to be (3.49 ± 0.04) × 10−3 and (1.82 ± 0.02) × 10−2 min−1. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45908.
Controllable shape‐memory recovery regions in polymers through mechanical programming
Authors: Zhang Cheng , Gou Xiaofan , Xiao Rui 
Published: October 2017

ABSTRACTA temperature memory effect means a shape‐memory material can remember its deformation temperature. In general, a higher deformation temperature requires a higher activation temperature for shape recovery. In this work, we demonstrate that the unloading temperature can also significantly influence the shape‐memory performance. A series of shape‐memory tests are performed on Nafion while varying the loading and unloading temperatures. The results show that the loading temperature determines the final shape‐recovery region, while the unloading temperature influences the onset recovery region. We also develop a finite‐deformation viscoelastic model to investigate the above findings. The simulation results show good agreement with the experimental data, though the model predicts the recovery region occurring at a lower temperature. The model is further used to study the effects of the loading rate, unloading rate, and the holding time on the shape‐memory behaviors. The results suggest that a smaller loading rate and unloading rate and a longer holding time can shift the recovery region to a higher temperature. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2018,135, 45909.
Effect of trisilanolphenyl‐POSS on rheological, mechanical, and flame‐retardant properties of poly(ethylene terephthalate)/cyclotriphosphazene systems
Authors: Li Jiawei , Yan Xiaojie , Zeng Xiandong , Yi Lingmin , Xu Hong , Mao Zhiping 
Published: October 2017

ABSTRACTPoly(ethylene terephthalate) (PET) chips were coated by trisilanolphenyl–polyhedral oligomeric silsesquioxane (T‐POSS) and hexakis (para‐allyloxyphenoxy) cyclotriphosphazene (PACP) using the predispersed solution method, and PET/PACP/T‐POSS hybrids were further prepared by the melt‐blending method. The influence of T‐POSS on the rheological, thermal, and mechanical properties and flame retardancy of PET/PACP composites were discussed. The results suggest that T‐POSS was homogeneously dispersed in the PET matrix, which reduced the negative effects on polymer rheology and mechanical properties. For the PET/4%PACP/1%T‐POSS sample, the tensile strength at break and Tg increased from 29.67 MPa and 81.7 °C (PET/5%PACP) to 34.8 MPa and 85.8 °C, respectively, but the sample also self‐extinguished within 2 s, and the heat release capacity was reduced by 27.9% in comparison with that of neat PET.© 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45912.
Antimicrobial open‐cell polyurethane foams with quaternary ammonium salts
Authors: Demirci Fatma , Yildirim Kenan , Kocer Hasan B. 
Published: October 2017

ABSTRACTAn hydroxyl‐terminated quaternary ammonium salt polymer (QAP) was added to a foam formulation in various amounts between 1 and 5 wt %. The structures of the produced foams and their QAP content were characterized by Fourier transform infrared and EDXRF analyses. A linear polymer of QAP with a diisocyanate was also synthesized to support our investigations. The morphological changes such as the cell size and the cell structure of the produced foams were observed with scanning electron microscopy. Thermogravimetric analysis and dynamic mechanical analysis analyses were applied to examine the thermal and thermomechanical properties of the produced foams. Relatively low amount of QAP‐added foams showed very similar structural and thermomechanical properties to the unmodified foams. In addition, while the unmodified foams did not show any antimicrobial activity, the QAP‐added foams provided significant inactivation against Staphylococcus aureus, yeast and mold at concentrations of about 102 and 103 CFU within 5 h of contact time. The results showed that the addition of minute amount of QAP can significantly improve the biocidal performance of the produced foams without deteriorating their structure. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45914.
Plasmonic organic bulk–heterojunction solar cells based on hydrophobic gold nanorod insertion into active layers
Authors: Liu Zhihai , Wang Tuntun , Nanda Sitansu Sekhar , Yi Dong Kee , Lee Eun‐Cheol 
Published: October 2017

ABSTRACTIn this work, we fabricated plasmonic organic bulk–heterojunction solar cells by inserting hydrophobic gold nanorods (GNRs) into the active layers. Power conversion efficiency was improved from 7.43% to 8.22% because the plasmonic effect of GNRs improved the light harvesting efficiency. Maximum exciton generation rate was increased from 1.35 × 10−26 to 1.51× 10−26m−3 s−1, and the electron mobility was also increased from 8.6 × 10−5 to 1.5× 10−4cm−2 V−1 s−1. As a result, the short circuit current density was improved from 15.5 to 16.7 mA cm−2—the dominant reason for performance enhancement. The open circuit voltage and fill factor were improved simultaneously. The plasmonic device showed a highest PCE of 8.43%, indicating that doping GNRs into active layers is a simple and effective way to fabricate high‐performance organic solar cells. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45920.
Paired geochemical and technological analyses of basalt adze debitage at the Hālawa Dune Site, Molokaʻi Island, Hawaiʻi
Authors: MILLS PETER , LIMA PŪLAMA , BRANDT LOKELANI , KAHN JENNIFER , KIRCH PATRICK , LUNDBLAD STEVEN 
Published: October 2017

ABSTRACTWe analysed 1593 basalt artefacts from the Hālawa Dune Site, on the easternmost part of Molokaʻi Island, for a combination of geochemical and technological attributes to expose different reduction strategies related to basalt adze production and rejuvenation. West Molokaʻi is well known as a location where many outcrops were quarried to make adzes, but the island's east side has not been widely perceived as a location where adzes were produced in significant quantities in the prehistoric economy. We infer, however, through large‐scale geochemical non‐destructive energy‐dispersive X‐ray fluorescence (EDXRF) analyses, combined with technological analyses, that the majority of adzes at the Hālawa Dune Site were manufactured from local resources, supporting a predominantly localised pattern of adze production and use. Approximately one third of the adze debitage clearly related to use and rejuvenation (DA) is made from non‐local sources, but does not represent a heavy reliance on the full range of quarries on West Molokaʻi, and may also include samples derived from other islands or archipelagos.