bluuebunny/crossref_metadata_2025_split huggingface dataset:
Adiposity‐Independent Effects of Aging on Insulin Sensitivity and Clearance in Mice and Humans
Authors: Ehrhardt Nicole , Cui Jinrui , Dagdeviren Sezin , Saengnipanthkul Suchaorn , Goodridge Helen S. , Kim Jason K. , Lantier Louise , Guo Xiuqing , Chen Yii‐Der I. , Raffel Leslie J. , Buchanan Thomas A. , Hsueh Willa A. , Rotter Jerome I. , Goodarzi Mark O. , Péterfy Miklós 
Published: February 2019

ObjectiveAging is associated with impaired insulin sensitivity and increased prevalence of type 2 diabetes. However, it remains unclear whether aging‐associated insulin resistance is due to increased adiposity or other age‐related factors. To address this question, the impact of aging on insulin sensitivity was investigated independently of changes in body composition.MethodsCohorts of mice aged 4 to 8 months (“young”) and 18 to 27 months (“aged”) exhibiting similar body composition were characterized for glucose metabolism on chow and high‐fat diets. Insulin sensitivity was assessed by hyperinsulinemic‐euglycemic clamp analyses. The relationship between aging and insulin resistance in humans was investigated in 1,250 nondiabetic Mexican Americans who underwent hyperinsulinemic‐euglycemic clamps.ResultsIn mice with similar body composition, age had no detrimental effect on plasma glucose and insulin levels. While aging did not diminish glucose tolerance, hyperinsulinemic‐euglycemic clamps demonstrated impaired insulin sensitivity and reduced insulin clearance in aged mice on chow and high‐fat diets. Consistent with results in the mouse, age remained an independent determinant of insulin resistance after adjustment for body composition in Mexican American males.ConclusionsThis study demonstrates that in addition to altered body composition, adiposity‐independent mechanisms also contribute to aging‐associated insulin resistance in mice and humans.
Maasai pastoralists kill lions in retaliation for depredation of livestock by lions
Authors: Ontiri Enoch M. , Odino Martin , Kasanga Antony , Kahumbu Paula , Robinson Lance W. , Currie Tom , Hodgson Dave J. 
Published: February 2019

Abstract

The borders of national parks in Kenya are hotspots for human–wildlife conflict. The deliberate killing of lions by Maasai pastoralists is illegal, but continues despite mitigation attempts. Currently, there is a somewhat pervasive opinion, within the human–wildlife conflict literature, that lions are killed by Maasai people either as cultural ceremony or indiscriminately in response to the loss of livestock.

We reconsider the indiscriminate reputation of lion‐killing, using a combination of structured dialogue and quantitative analysis. Focus group discussions with Maasai pastoralists in three different pastoral regions, performed by in‐country experts, minimized the risk of cross‐cultural misinterpretation through a platform of shared Kenyan heritage.

In our survey of 213 Maasai pastoralist communities, we found universal agreement that humans and lions should coexist in Kenya.

Maasai communities distinguished among drought, disease, theft, loss and depredation as drivers of livestock losses. Maasai also distinguished among predatory species that take their livestock. The only cause of livestock loss that provoked increased killing of lions, was depredation by lions. Lion‐killing was not provoked by other predatory species. We found regional variation in the baseline probability of lion‐killing, and discuss the sources of this variation.

The probability of lion‐killing increases as an act of retribution for predation of livestock that discriminates among species of carnivore. This, coupled with universal acceptance of coexistence between lions and Maasai pastoralists, should guide mitigation strategies for human–wildlife interactions in Kenya and beyond.

A plain language summary is available for this article.
The effects of intraband and interband carrier‐carrier scattering on hot‐carrier solar cells: A theoretical study of spectral hole burning, electron‐hole energy transfer, Auger recombination, and impact ionization generation
Authors: Tsai Chin‐Yi 
Published: February 2019

AbstractThe effects of carrier‐carrier scattering resulting from the Coulomb‐potential interaction between two electrons on hot‐carrier solar cells are theoretically studied. Theoretical models and explicit formulas for calculating intraband carrier‐carrier scattering rates, electron‐to‐hole energy transfer rates, Auger recombination rates, and impact ionization generation rates are presented and derived. The numerical calculations from these formulas are obtained, and their effects on hot‐carrier solar cells are investigated. Several findings can be concluded from this study: (1) Intraband electron‐electron scattering and hole‐hole scattering are normally fast enough to randomize carrier distribution in the momentum space and thus maintain quasiequilibrium to establish electron and hole temperatures at a steady state; (2) spectral hole burning in hot‐carrier solar cells can be incurred by fast carrier extraction processes through energy‐selective contacts and slow intraband carrier‐carrier scattering; (3) energy transfer between electrons and holes via intraband electron‐hole scattering cannot guarantee that electrons and holes will maintain the same carrier temperature for hot‐carrier solar cells in all cases, especially if the difference between electron and hole temperatures is smaller than 100 K; and (4) materials with a band‐gap energy larger than 1 eV are favorable as conventional solar cells in which Auger recombination is not significant. On the contrary, materials with a band‐gap energy smaller than 0.5 eV are not suitable for conventional solar cells due to the detrimental effects of Auger recombination. However, they are ideal materials for realizing hot‐carrier solar cells due to beneficial effects of impact ionization generation, although these beneficial effects can be undermined by spectral hole burning.
The Role of the Headmaster Collar (Cervical) for Dropped Head Syndrome in Hodgkin Lymphoma Survivors
Authors: Kim Arum , Stubblefield Michael D. 
Published: February 2019

AbstractBackgroundDropped head syndrome is a potential late neurologic complication of radiation therapy in survivors of Hodgkin lymphoma. There is limited evidence for conservative management of this condition.ObjectiveTo discover patient utilization patterns of the commonly prescribed Headmaster Collar (cervical) in Hodgkin lymphoma survivors with radiation‐induced dropped head syndrome.DesignQuestionnaire‐based retrospective observational study.SettingSingle‐site academic cancer center.PatientsTwenty‐six Hodgkin lymphoma survivors treated with radiation therapy involving the mantle who were prescribed a Headmaster Collar for dropped head syndrome.Methods or InterventionsPatients were interviewed by phone with a structured set of questions.Main Outcome MeasurementsCompliance, patterns of use, individual modifications, and side effects of collar use.ResultsAlthough 58% of patients who were prescribed a Headmaster Collar eventually discontinued its use, 62% of all patients used the collar for more than 6 months. The majority of users wore the collar for up to 3 hours per day, usually for static seated activities. Thirty‐eight percent of patients made personal modifications to their collar, most commonly the addition of extra padding. All but one patient had complaints about the collar, most commonly discomfort, rigidity, and confinement.ConclusionsThe Headmaster Collar (cervical) is often utilized for a few hours a day, for longer than 6 months, to help with static seated activities. Insights from this study might help to improve future orthotic designs with better long‐term compliance rates for the treatment of radiation‐induced dropped head syndrome.Level of EvidenceIV
Optoelectronic and charge‐transport properties of truxene, isotruxene, and its heteroatomic (N, O, Si, and S) analogs: A DFT study
Authors: Tripathi Anuj , Prabhakar Chetti 
Published: February 2019

AbstractThe main objective of this work is to provide a detailed study of optoelectronic and charge‐transport properties of truxene, isotruxene, and their heteroatomic analogs (azatruxene and isoazatruxene, oxatruxene and isooxatruxene, silatruxene and isosilatruxene, and thiatruxene and isothiatruxene). Systematic studies of these molecules were performed by means of the density functional theory (DFT) and time‐dependent DFT (TD‐DFT) calculations. Electronic excitations (absorption spectra), reorganization energies (hole‐ and electron‐transport properties), electron affinities (EAs), ionization potentials (IPs), hole extraction potentials (HEPs), and electron extraction potentials (EEPs) for all the molecules were reported. Based on the comparative study, it is showed that thiatruxenes (isothiatruxene) are better hole‐transport materials than other truxene (isotruxene) analogs.
Crystal structure of the apo form of a β‐transaminase from Mesorhizobium sp. strain LUK
Authors: Kwon Sunghark , Park Hyun H. 
Published: February 2019

AbstractPyridoxal 5′‐phosphate (PLP)‐dependent β‐transaminases (βTAs) reversibly catalyze transamination reactions by recognizing amino groups linked to the β‐carbon atoms of their substrates. Although several βTA structures have been determined as holo forms containing PLP, little is known about the effect of PLP on the conversion of the apo structure to the holo structure. We determined the crystal structure of the apo form of a βTA from Mesorhizobium sp. strain LUK at 2.2 Å resolution to elucidate how PLP affects the βTA structure. The structure revealed three major disordered regions near the active site. Structural comparison with the holo form also showed that the disordered regions in the apo form are ordered and partially adopt secondary structures in the holo form. These findings suggest that PLP incorporation into the active site contributes to the structural stability of the active site architecture, thereby forming the complete active site. Our results provide novel structural insights into the role of PLP in terms of active site formation.
Evaluation of a noncanonical Cys40‐Cys55 disulfide linkage for stabilization of single‐domain antibodies
Authors: Kim Dae Young , Kandalaft Hiba , Hussack Greg , Raphael Shalini , Ding Wen , Kelly John F. , Henry Kevin A. , Tanha Jamshid 
Published: February 2019

AbstractIncorporation of noncanonical disulfide linkages into single‐domain antibodies (sdAbs) has been shown to enhance thermostability and other properties. Here, we evaluated the effects of introducing a novel disulfide linkage formed between Cys residues at IMGT positions 40 and 55 on the melting temperatures (T
ms), reversibility of thermal unfolding, solubility, and antigen‐binding affinities of three types of sdAbs (VHH, VH, and VL domains). The Cys40‐Cys55 disulfide linkage was tolerated by 9/9 VHHs, 12/12 VHs, and 2/11 VLs tested and its formation was confirmed by mass spectrometry. Using circular dichroism, we found that the Cys40‐Cys55 disulfide linkage increased sdAb T
m by an average of 10.0°C (range: 0–21.8°C). However, enhanced thermostability came at the cost of a partial loss of refolding ability upon thermal denaturation as well as, for some sdAbs, significantly decreased solubility and antigen‐binding affinity. Thus, Cys40/Cys55 can be added to the panel of known locations for introducing stabilizing noncanonical disulfide linkages into antibody variable domains, although its effects should be tested empirically for individual sdAbs.
A review of progress toward field application of transgenic mosquitocidal entomopathogenic fungi
Authors: Lovett Brian , Bilgo Etienne , Diabate Abdoulaye , St. Leger Raymond 
Published: February 2019

AbstractIn Africa, adult mosquito populations are primarily controlled with insecticide‐impregnated bed nets and residual insecticide sprays. This coupled with widespread applications of pesticides in agriculture has led to increasing insecticide resistance in mosquito populations. We have developed multiple alternative strategies for exploiting transgenic Metarhizium spp. directed at: (i) shortening the lifespan of adult mosquitoes; (ii) reducing transmission potential of Plasmodium spp.; (iii) reducing vector competence via pre‐lethal effects. The present challenge is to convert this promising strategy into a validated public health intervention by resolving outstanding issues related to the release of genetically modified organisms. © 2019 Society of Chemical Industry
Probing molecular environments with a fictitious isotopic dipole
Authors: Mohallem José R. , Velloso Paulo F. G. , Arapiraca Antonio F. C. 
Published: February 2019

AbstractA HD‐like (HD: mono‐deuterated hydrogen molecule) isotopic dipole moment is proposed as a sensible probe for molecular environments, in particular for electrostatic fields and polarizable (reactive) sites of molecules. Fictitious nuclear masses are chosen in order to yield a rigid dipole with a small appropriate magnitude. Upon subtracting the Born‐Oppenheimer energy, the interaction is reduced to field‐dipole‐like and dipole‐polarizability‐like terms, the last one being particularly informative since connected to potentially reactive sites. Possible asymmetries of this term appear as signatures of charged sites in the molecule. The field strength and orientation are easily obtained by identifying the minimum field‐dipole energy configuration and flipping the dipole from it. Tests with hydrogen, water, benzene, and chlorobenzene molecules confirm the good performance of the method. In an application to test the present models for hydrogen activation by a frustrated Lewis pair, the full potential of the method is assessed.
Design, Synthesis and Biological Evaluation of Substituted (1‐(4‐chlorobenzyl)‐1H‐indol‐3‐yl) 1H‐(1,2,3‐triazol‐4‐yl)methanones as Antifungal Agents
Authors: Shareef Mohd Adil , Rajpurohit Hemshikha , Sirisha K. , Sayeed Ibrahim Bin , Khan Irfan , Kadagathur Manasa , Ganapathi Thipparapu , Kumar C. Ganesh , Kamal Ahmed , Babu Bathini Nagendra 
Published: February 2019

AbstractIn the perusal of our endeavour towards the synthesis of new bioactive agents, a new series of substituted (1‐(4‐chlorobenzyl)‐1H‐indol‐3‐yl) 1H‐(1,2,3‐triazol‐4‐yl) methanones (8a‐u) were designed, synthesized and investigated for their antimicrobial activity with special emphasis on their anti‐Candida potential and Candida biofilm inhibition. Among them, the hybrids 8e, 8f, and 8o demonstrated significant antifungal activity on most of the tested fungal strains with MIC values ranging between 1.9–7.8 μg/mL. In addition, the most promising compounds were found to be effective biofilm inhibitors. We have studied the Field emission Scanning Electron Microscope (FE‐SEM) micrographs for 8f to know the damage of the cells with altered membrane integrity and release of intracellular contents thereby validating the in vitro biofilm inhibition assay. Further, in enzymatic assay, active compounds inhibited ergosterol biosynthesis. Furthermore, docking studies revealed that they effectively bind to 14α‐demethylase (CYP51), thereby inhibiting ergosterol biosynthesis. Interestingly, they exhibited lower cytotoxicity in the normal cell line (MRC5).
Facile and Green One‐Pot Synthesis of Fluorophore Chromeno[4,3‐b]quinolin‐6‐one Derivatives Catalyzed by Halloysite Nanoclay under Solvent‐free Conditions
Authors: Ataee‐Kachouei Tahereh , Nasr‐Esfahani Mahboobeh , Baltork Iraj Mohammadpoor‐ , Mirkhani Valiollah , Moghadam Majid , Tangestaninejad Shahram , Kia Reza 
Published: February 2019

AbstractIn this study, we demonstrated a straightforward method for the easy access of chromeno[4,3‐b]quinolin‐6‐ones via a one‐pot three‐component reaction of 4‐hydroxycoumarin, aldehydes and aryl amines in the presence of halloysite nanoclay as an eco‐friendly, inexpensive and green heterogeneous catalyst under solvent‐free conditions. Moreover, symmetric and unsymmetric bis‐chromeno[4,3‐b]quinolin‐6‐ones were obtained from dialdehyde or diamines in good yields by this method. To date, this is the first report on the synthesis of symmetric and unsymmetric bis‐chromeno[4,3‐b]quinolin‐6‐ones via such a one‐pot, multicomponent reaction. Some prepared chromeno[4,3‐b]quinolin‐6‐ones displayed as interesting fluorophore compounds, hereupon their fluorescence properties were considered. Good to excellent yields, short reaction times and avoidance of toxic solvents are the significant features of this green procedure.
Size‐Control and Surface Modification of Flexible Metal‐Organic Framework MIL‐53(Fe) by Polyethyleneglycol for 5‐ Fluorouracil Anticancer Drug Delivery
Authors: Nguyen Thi Hoai Phuong , Ninh Ha Duc , Tran Chinh Van , Le Bac Thanh , Bhosale Sheshanath V. , La Duong Duc 
Published: February 2019

AbstractThe flexible metal‐organic frameworks (MOFs) materials, also called soft porous crystals which combine the crystalline order of the underlying coordination network with cooperative structural transformability, have been extensively studied as promising materials for various applications such as sensing, drug delivery, catalysis, host‐guest complex etc. Among them MOFs is effectively used as a carrier for drug delivery. Herein, a flexible metal‐organic framework MIL‐53(Fe) functionalized with polyethyleneglycol (PEG) was successfully fabricated by ultrasonication. The prepared material was characterized by scanning electron microscopy (SEM), X‐ray diffraction (XRD), transmittance electron microscopy (TEM), Brunauer‐Emmett‐Teller (BET) surface area and infrared spectroscopy (IR). The effect of the PEG content on the morphology and particles size of the MIL‐53 was investigated in detail. The resultant flexible MIL‐53(Fe)‐PEG materials were seen to be homogeneous with the morphology of hexagonal bipyramidal structure, approximately 700 nm in length and 400 nm in diameter. Furthermore, we investigated loading of 5‐fluorouracil (5‐FU) drug and its release in vitro conditions by employing MIL‐53(Fe)‐PEG. The results showed that in vitro condition, only 31% of the drug released after 3 h, and released completely after approximately 6 days. Thus, we believe that use of MIL‐53(Fe)‐PEG may overcome current issue of sustain release.
A Facile One Pot Synthesis of Cu2O@TiO2: A Nanocomposite Catalyst for Enhanced Visible Light Driven Photocatalysis#
Authors: Surikanti Ganesh Reddy , Bandarapu Arun Kumar , Sunkara Manorama V. 
Published: February 2019

AbstractThe highlight of this study is a successful attempt to obtain a visible light active photo catalyst by a single step synthesis procedure. The photocatalytic performance of Cu2O, a p‐type semiconducting oxide with a band gap in the visible region of the solar spectrum is improved by the presence of TiO2 on its surface. Nanocomposites of Cu2O@TiO2 were synthesized by a facile one pot synthesis route. X‐ray diffraction (XRD) studies confirmed the face centred cubic structure of Cu2O but was inconclusive about the TiO2 presence. Field Emission Scanning Electron Microscopy (FE‐SEM) images confirmed the octahedral morphology of the Cu2O particles and the presence of Ti and O on the surface. High Resolution Transmission Electron Microscopy (HR‐TEM) and Selected Area Electron Diffraction (SAED) studies established the presence of nanocrystalline anatase TiO2 on the Cu2O interfaces. The specific role of the nanoparticles of n‐type TiO2 positioned on the p‐type Cu2O in improving photo‐activity and making it visible light active was demonstrated. The photocatalytic activity of the composite was demonstrated by the degradation of a model dye Rhodamine B using visible light. It is observed that the photocatalytic activity is dependent on density of heterojunctions formed in the photo‐system which the nano‐crystalline TiO2 , has very effectively created on the Cu2O surface, which are responsible for the improved photocatalytic response. This work establishes that the in‐situ creation of Cu2O@TiO2 is effective in creating p‐n heterojunctions at the Cu2O@TiO2 interface, which result in arresting the recombination processes, leading to improved photocatalytic performance.
Transducing Protease Activity into DNA Output for Developing Smart Bionanosensors
Authors: Bui Hieu , Brown Carl W. , Buckhout‐White Susan , Díaz Sebastián A. , Stewart Michael H. , Susumu Kimihiro , Oh Eunkeu , Ancona Mario G. , Goldman Ellen R. , Medintz Igor L. 
Published: February 2019

AbstractDNA can process information through sequence‐based reorganization but cannot typically receive input information from most biological processes and translate that into DNA compatible language. Coupling DNA to a substrate responsive to biological events can address this limitation. A two‐component sensor incorporating a chimeric peptide‐DNA substrate is evaluated here as a protease‐to‐DNA signal convertor which transduces protease activity through DNA gates that discriminate between different input proteases. Acceptor dye‐labeled peptide‐DNAs are assembled onto semiconductor quantum dot (QD) donors as the input gate. Addition of trypsin or chymotrypsin cleaves their cognate peptide sequence altering the efficiency of Förster resonance energy transfer (FRET) with the QD and frees a DNA output which interacts with a tetrahedral output gate. Downstream output gate rearrangement results in FRET sensitization of a new acceptor dye. Following characterization of component assembly and optimization of individual steps, sensor ability to discriminate between the two proteases is confirmed along with effects from joint interactions where potential for cross‐talk is highest. Processing multiple bits of information for a sensing outcome provides more confidence than relying on a single change especially for the discrimination between different targets. Coupling other substrates to DNA that respond similarly could help target other types of enzymes.
The development of students' justifications for their positions regarding two theoretical models: Electron cloud or sodium chloride crystal—After engaging in different learning activities
Authors: Al‐Balushi Sulaiman M. , Martin‐Hansen Lisa 
Published: February 2019

AbstractThe purpose of this study was to explore high school students' ideas regarding two theoretical scientific models, either electron cloud or sodium chloride crystal, in the context of active learning in small groups. Conversations among peers regarding these models took place during two types of active learning activities: small‐group discussion and whole‐class debate. The study was conducted in four different high school classes, each of which was in a different school for girls in Oman. The study included 108 grade 10 female students. Two of the classes discussed the electron cloud and the other two classes discussed the sodium chloride model. Qualitative data included students' written responses to prompts, class worksheets, and field notes of student ideas in class debates. In each class, the teacher used a teaching sequence during which the participants expressed their justifications for their positions in writing regarding the particular model on five different occasions, as they progressed through three interactive small group learning activities. The participants' written responses were analyzed using a coding scheme comprising of eight different categories describing the participants' type of justifications regarding the theoretical scientific models: nonsense, approval, mental, experimental, appreciative, external, structural, and modeling. The findings indicated that participants' justifications for their positions regarding theoretical scientific models tended to change over time following each group learning activity. Participants focused their discussion more on external factors, such as the teacher, textbook, religion, and media, after discussions with peers in small groups. In contrast, later their attention focused more on the submicroscopic structural orientations of the model under study during and after engaging in a debating activity. The researchers reasoned that the nature of cognitive demands during each type of active learning activity might play a role in this regard. However, further research to advance the understanding of this phenomenon is needed.