bluuebunny/crossref_metadata_2025 huggingface dataset:
Internet Addiction
Authors: Johnson Nicola F.
Published: November 2019

Internet addiction refers to what is considered to be abnormal, problematic, heavy, or overuse of the Internet. The significant increase in digital consumption, including online gaming and gambling has been widely researched since the Internet Addiction Test (IAT) was published in 1998. Despite increased digital consumption, including online gaming and gambling, the IAT continues to be utilized with few modifications. There has been much quantitative research into the phenomenon that reinforces the belief that heavy Internet use is abnormal and that dependence on the Internet constitutes a negative addiction. Despite this, the everyday, habitual, frequent use of digital devices and, in particular, dependence on smartphones, suggests the concept of Internet addiction is inadequate.
Practice Theories
Authors: Weenink Don , Spaargaren Gert
Published: November 2019

Practice theories perceive social life as practical activity. Social practices can be described as routinized behavior which integrates elements such as bodily know‐how, material objects, technology, understandings, and emotions. Practice theories focus on how such elements are interwoven through human activity. They acknowledge the coconstituting role of material objects and emphasize practical intelligibility, the embodied ways in which people know what and how to do next in a situation. The very capacity of individuals to act upon their environment is produced in and through social practices. Practice theories perceive social reality as one of a kind: No distinctions are made between social realms, layers or levels. So far, this branch of theorizing has proven its strength for understanding microphenomena in dispersed places and times. Recently, theorists have begun to conceptualize the dynamics of more extensive patterning of practice‐material arrangement bundles in time and space. For instance, they can appear more or less frequent, more or less firmly or densely clustered, and more or less related to other practices in more or less stringent and enduring ways. If practice theories manage to demonstrate utility and merit for understanding stability and change in larger social phenomena they are here to stay in sociology.
Sexualities, Cities and
Authors: Hubbard Phil
Published: November 2019

The sexual life of cities is understood to be more varied and liberated than that associated with rural life, with large cities in particular known as hubs for “queer” sexual life as well as serving as centers of sexual commerce and prostitution. This entry reviews dominant themes in urban sociology concerning the sexual life of cities, and draws conclusions about the changing importance of cities in an era when sexual relationships and identities are increasingly negotiated (and even transacted) at a distance.
Social Darwinism
Authors: Adams Matthew S.
Published: November 2019

Charles Darwin's work had an important, but complex, impact on social thinking in the nineteenth century. Although the language of evolution was integral to social thought before publication of
On the Origin of Species
in 1859, social theorists increasingly turned to evolutionary theory to help understand human societies as the significance of Darwin's contribution to the biological sciences became more apparent. Social Darwinism encompassed a melange of competing ideas, and had appeal across the political spectrum, but it nevertheless became a crucial component of theoretical interventions that were integral to the formation of modern sociology.
Laser‐Assisted, Large‐Area Selective Crystallization and Patterning of Titanium Dioxide Polymorphs
Authors: Gerlein Luis Felipe , Benavides-Guerrero Jaime Alberto , Cloutier Sylvain G.
Published: November 2019

Although ubiquitous in multiple industrial applications, the widespread use of solution‐based precursors for crystalline titanium dioxide (TiO2) for optoelectronic device integration remains limited due to its high processing temperature. This limitation generates material compatibility issues and complicates the fabrication steps, especially for low‐temperature substrates used in flexible hybrid electronics and low‐cost photovoltaics. It is currently possible to crystallize TiO2 at lower processing temperatures, but it requires a carefully controlled atmosphere or metallic doping of the amorphous precursor and can only achieve a low‐yield conversion of the precursor. Herein, a qualitative method is presented for the processing of an amorphous photosensitive precursor to achieve high‐yield conversion to highly crystalline TiO2 at room temperature and in ambient environment without added dopants using a low‐energy laser. Moreover, it demonstrates the ability to controllably convert precursor solutions to anatase or rutile TiO2 only by adjusting the laser power density. A real potential for the additive manufacturing of TiO2 structures for photocatalysis, printable flexible hybrid electronics, and low‐cost photovoltaics using low‐energy laser processing that is compatible with heat‐sensitive materials and flexible substrates is shown.
Nanofabrication on 2D and 3D Topography via Positive‐Tone Direct‐Write Laser Lithography
Authors: Heiskanen Samuli , Geng Zhuoran , Mastomäki Jaakko , Maasilta Ilari J.
Published: November 2019

Direct laser writing (DLW) lithography using two‐photon absorption is a powerful technique mostly used for the fabrication of complex structures in micro‐ and nanoscale, by photopolymerizing a negative‐tone resist. In contrast, herein, it is demonstrated that DLW is also well suited for fabricating nano‐ to microscale metallic structures using liftoff and a positive‐tone photoresist. It is shown first that versatile, fast, and large‐area fabrication is possible on flat 2D insulating substrates, and an expression for how the line width varies with the scanning speed is derived, with excellent agreement with the experiments. Even more interestingly, a unique application for the DLW lift‐off process is demonstrated, by fabricating submicron scale metallic wiring on uneven substrates with sloping elevation changes as high as 20 μm. Such fabrication is practically impossible with more standard lithographic techniques.
Lewis Acid‐Catalyzed Stereoselective α‐Addition of Chiral Aldehydes to Cyclic Dienol Silanes: Aqueous Synthesis of Chiral Butenolides
Authors: Adamkiewicz Anna , Węglarz Izabela , Butkiewicz Aleksandra , Woyciechowska Marta , Mlynarski Jacek
Published: November 2019

The stereoselective α‐addition to cyclic dienol silanes has rarely been exploited, in contrast to the well‐studied γ‐addition of conjugated butenolides. In this study, an unprecedent catalytic Mukaiyama aldol α‐addition of 2‐trimetylsiloxy furan to optically pure aldehydes in water‐containing solvents is reported. The synthetic utility of this concept was demonstrated in the efficient synthesis of six bioactive natural products: vitexolide D, curcucomosin C, villosin, chinensine C, (+)‐coronarin E and (E)‐labda‐7,11,13‐trien‐16,15‐olid.

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Ultrahigh Nitrogen Doping of Carbon Nanosheets for High Capacity and Long Cycling Potassium Ion Storage
Authors: Chang Xingqi , Zhou Xiaolong , Ou Xuewu , Lee Chun‐Sing , Zhou Jiwei , Tang Yongbing
Published: November 2019

Potassium‐based energy storage devices (PESDs) are promising candidates for large‐scale energy storage applications owing to potassiums abundant in nature, the low standard redox potential (−2.93 V for K/K+ vs the standard hydrogen electrode) of potassium (K), and high ionic conductivity of K‐ion based electrolytes. However, lack of proper cathode and anode materials hinder practical applications of PESDs. In this work, carbon nanosheets doped with an ultrahigh content of nitrogen (22.7 at%) are successfully synthesized as an anode material for a K‐ion battery, which delivers a high capacity of 410 mAh g−1 at a current density of 500 mA g−1, which is the best result among the carbon based anodes for PESDs. Moreover, the battery exhibits an excellent cycling performance with a capacity retention of 70% after 3000 cycles at a high current density of 5 A g−1. In situ Raman, galvanostatic intermittent titration, and density functional theory calculations reveal that the ultrahigh N‐doped carbon nanosheet (UNCN) simultaneously combines the diffusion and pseudocapacitive mechanisms together, which remarkably improves its electrochemical performances in K‐ion storage. These results demonstrate the good potential of UNCNs as a high‐performance anode for PESDs.
Magnetic Resonance Imaging System–Driven Medical Robotics
Authors: Erin Onder , Boyvat Mustafa , Tiryaki Mehmet Efe , Phelan Martin , Sitti Metin
Published: November 2019

Magnetic resonance imaging (MRI) system–driven medical robotics is an emerging field that aims to use clinical MRI systems not only for medical imaging but also for actuation, localization, and control of medical robots. Submillimeter scale resolution of MR images for soft tissues combined with the electromagnetic gradient coil–based magnetic actuation available inside MR scanners can enable theranostic applications of medical robots for precise image‐guided minimally invasive interventions. MRI‐driven robotics typically does not introduce new MRI instrumentation for actuation but instead focuses on converting already available instrumentation for robotic purposes. To use the advantages of this technology, various medical devices such as untethered mobile magnetic robots and tethered active catheters have been designed to be powered magnetically inside MRI systems. Herein, the state‐of‐the‐art progress, challenges, and future directions of MRI‐driven medical robotic systems are reviewed.
Workers’ compensation claims for traumatic brain injuries among private employers—Ohio, 2001‐2011
Authors: Konda Srinivas , Al‐Tarawneh Ibraheem S. , Reichard Audrey A. , Tiesman Hope M. , Wurzelbacher Steven J. , Pinkerton Lynne E. , Meyers Alysha R. , Hendricks Scott A. , Tseng Chih‐Yu , Lampl Michael P. , Robins David C.
Published: November 2019

Background

The purpose of this analysis was to identify and prioritize high‐risk industry groups for traumatic brain injury (TBI) prevention efforts.

Methods

Workers with TBI from 2001 to 2011 were identified from the Ohio Bureau of Workers’ Compensation data. To prioritize industry groups by claim type (lost‐time (≥8 days away from work) and total claims) and injury event categories, we used a prevention index (PI) that averaged TBI counts and rate ranks (PI = (count rank + rate rank)/2). TBI rates per 10 000 estimated full‐time equivalent (FTE = 2000 h/y) workers were calculated.

Results

From 2001 to 2011, 12 891 TBIs were identified among private employers, resulting in a rate of 5.1 TBIs per 10 000 FTEs. Of these, 40% (n = 5171) were lost‐time TBIs, at a rate of 2.0 per 10 000 FTEs. Spectator Sports had the highest lost‐time TBI rate (13.5 per 10 000 FTEs), whereas General Freight Trucking had the greatest number of lost‐time TBIs (n = 293). Based on PIs, General Freight Trucking ranked first for lost‐time TBIs for all injury events combined. Several industry groups within Construction, General and Specialized Freight Trucking, Services to Building and Dwellings, Employment Services, and Restaurants and Other Eating Places ranked high across multiple injury event categories for lost‐time TBIs.

Conclusions

The high‐ranking industry groups identified from our study can be used to effectively direct occupational TBI prevention efforts.
Microwave‐Assisted Synthesis as an Efficient Method to Enhance the Catalytic Activity of Zr‐Based Metal Organic Framework UiO‐66 in a Heterocyclization Reaction
Authors: Nguyen Linh Ho Thuy , Nguyen Trang Thi Thu , Dang Y. Thi , Tran Phuong Hoang , Le Hoang Doan Tan
Published: November 2019

Zr‐based metal‐organic frameworks have been considered promising heterogeneous catalysts in various reactions. It has been proven that the defect sites in these frameworks, which result from deficiency of linkers, could act as the reaction active sites. In this work, microwave irradiation was used for rapid synthesis and increasing defects on Zr6 clusters of metal‐organic framework UiO‐66. Powder X‐ray diffraction, thermal gravimetric analysis, and N2 sorption isotherms were performed to characterize and calculate the defect number in the framework. UiO‐66 prepared by microwave method for a few minutes could reach 1.8 missing linkers per cluster. The material with acetic acid as a co‐catalyst showed highly heterogeneous catalytic activity in the solvent‐free heterocyclization of 2,2‐disubstituted 2,3‐dihydroquinazolin‐4(1H)‐ones from anthranilamide and ketones/aldehydes. The synthetic scheme consisted of zirconium cluster catalysed carbonyl group of anthranilamide to achieve the C−N propitious combination and succeeding ring closure process.
Visible Light‐Mediated C2‐Quaternarization of N‐Alkyl Indoles through Oxidative Dearomatization using Ir(III) Catalyst
Authors: Shukla Gaurav , Dahiya Anjali , Alam Tipu , Patel Bhisma K.
Published: November 2019

In the presence of [Ir(dtbbpy)(ppy)2]PF6 photocatalyst and white LEDs, one‐third of N‐alkylated indoles undergo oxidative dearomatization and serves twice as the C2‐electrophilic partner. The remaining two‐third act as the C3‐nucleophile, prompting two sequential electrophilic substitutions with the in situ generated C2‐electrophile that leads to C2‐quaternary indolinones at room temperature.
Detecting Counterion Dynamics in DNA–Protein Association
Authors: Pletka Channing C. , Nepravishta Ridvan , Iwahara Junji
Published: November 2019

Due to a high density of negative charges on its surface, DNA condenses cations as counterions, forming the so‐called “ion atmosphere”. Although the release of counterions upon DNA–protein association has been postulated to have a major contribution to the binding thermodynamics, this release remains to be confirmed through a direct observation of the ions. Herein, we report the characterization of the ion atmosphere around DNA using NMR spectroscopy and directly detect the release of counterions upon DNA–protein association. NMR‐based diffusion data reveal the highly dynamic nature of counterions within the ion atmosphere around DNA. Counterion release is observed as an increase in the apparent ionic diffusion coefficient, which directly provides the number of counterions released upon DNA–protein association.
Cobalt(III)‐Catalyzed C−H Amidation of Dehydroalanine for the Site‐Selective Structural Diversification of Thiostrepton
Authors: Scamp Ryan J. , deRamon Edward , Paulson Eric K. , Miller Scott J. , Ellman Jonathan A.
Published: November 2019

Thiostrepton is a potent antibiotic against a broad range of Gram‐positive bacteria, but its medical applications have been limited by its poor aqueous solubility. In this work, the first C(sp2)−H amidation of dehydroalanine (Dha) residues was applied to the site selective modification of thiostrepton to prepare a variety of derivatives. Unlike all prior methods for the modification of thiostrepton, the alkene framework of the Dha residue is preserved and with complete selectivity for the Z‐stereoisomer. Additionally, an aldehyde group was introduced by C−H amidation, enabling oxime ligation for the installation of an even greater range of functionality. The thiostrepton derivatives generally maintain antimicrobial activity, and importantly, eight of the derivatives displayed improved aqueous solubility (up to 28‐fold), thereby addressing a key shortcoming of this antibiotic. The exceptional functional group compatibility and site selectivity of CoIII‐catalyzed C(sp2)−H Dha amidation suggests that this approach could be generalized to other natural products and biopolymers containing Dha residues.
A Deep‐Cycle Aqueous Zinc‐Ion Battery Containing an Oxygen‐Deficient Vanadium Oxide Cathode
Authors: Liao Meng , Wang Jiawei , Ye Lei , Sun Hao , Wen Yunzhou , Wang Chuang , Sun Xuemei , Wang Bingjie , Peng Huisheng
Published: November 2019

Rechargeable aqueous zinc‐ion batteries are attractive because of their inherent safety, low cost, and high energy density. However, viable cathode materials (such as vanadium oxides) suffer from strong Coulombic ion–lattice interactions with divalent Zn2+, thereby limiting stability when cycled at a high charge/discharge depth with high capacity. A synthetic strategy is reported for an oxygen‐deficient vanadium oxide cathode in which facilitated Zn2+ reaction kinetic enhance capacity and Zn2+ pathways for high reversibility. The benefits for the robust cathode are evident in its performance metrics; the aqueous Zn battery shows an unprecedented stability over 200 cycles with a high specific capacity of approximately 400 mAh g−1, achieving 95 % utilization of its theoretical capacity, and a long cycle life up to 2 000 cycles at a high cathode utilization efficiency of 67 %. This work opens up a new avenue for synthesis of novel cathode materials with an oxygen‐deficient structure for use in advanced batteries.
Copper‐Catalyzed Enantioselective Allylic Alkylation with a γ‐Butyrolactone‐Derived Silyl Ketene Acetal
Authors: Jette Carina I. , Tong Z. Jaron , Hadt Ryan G. , Stoltz Brian M.
Published: November 2019

Herein, we report a Cu‐catalyzed enantioselective allylic alkylation using a γ‐butyrolactone‐derived silyl ketene acetal. Critical to the development of this work was the identification of a novel mono‐picolinamide ligand with the appropriate steric and electronic properties to afford the desired products in high yield (up to 96 %) and high ee (up to 95 %). Aryl, aliphatic, and unsubstituted allylic chlorides bearing a broad range of functionality are well‐tolerated. Spectroscopic studies reveal that a CuI species is likely the active catalyst, and DFT calculations suggest ligand sterics play an important role in determining Cu coordination and thus catalyst geometry.
Controllable Conversion of CO2on Non‐Metallic Gold Clusters
Authors: Yang Dan , Pei Wei , Zhou Si , Zhao Jijun , Ding Weiping , Zhu Yan
Published: November 2019

Gold nanoparticles in metallic or plasmonic state have been widely used to catalyze homogeneous and heterogeneous reactions. However, the catalytic behavior of gold catalysts in non‐metallic or excitonic state remain elusive. Atomically precise Aunclusters (n=number of gold atoms) bridge the gap between non‐metallic and metallic catalysts and offer new opportunities for unveiling the hidden properties of gold catalysts in the metallic, transition regime, and non‐metallic states. Here, we report the controllable conversion of CO2over three non‐metallic Aunclusters, including Au9, Au11, and Au36, towards different target products: methane produced on Au9, ethanol on Au11, and formic acid on Au36. Structural information encoded in the non‐metallic clusters permits a precise correlation of atomic structure with catalytic properties and hence, provides molecular‐level insight into distinct reaction channels of CO2hydrogenation over the three non‐metallic Au catalysts.
Manganese‐Catalyzed β‐Methylation of Alcohols by Methanol
Authors: Schlagbauer Martin , Kallmeier Fabian , Irrgang Torsten , Kempe Rhett
Published: November 2019

We report an earth‐abundant‐metal‐catalyzed double and single methylation of alcohols. A manganese catalyst, which operates at low catalyst loadings and short reaction times, mediates these reactions efficiently. A broad scope of primary and secondary alcohols, including purely aliphatic examples, and 1,2‐aminoalcohols can be methylated. Furthermore, alcohol methylation for the synthesis of pharmaceuticals has been demonstrated. The catalyst system tolerates many functional groups among them hydrogenation‐sensitive examples and upscaling is easily achieved. Mechanistic investigations are indicative of a borrowing hydrogen or hydrogen autotransfer mechanism involving a bimetallic K‐Mn catalyst. The catalyst accepts hydrogen as a proton and a hydride from alcohols efficiently and reacts with a chalcone via hydride transfer.
Reconstruction of the historical distribution ranges of imperilled stream fishes from a global endemic hotspot based on molecular data: Implications for conservation of threatened taxa
Authors: Chakona Albert , Gouws Gavin , Kadye Wilbert T. , Jordaan Martine S. , Swartz Ernst R.
Published: November 2019

Understanding historical distribution patterns of freshwater fishes prior to human impacts is crucial for informing effective strategies for biodiversity conservation. However, incomplete information on species occurrence records, the existence of cryptic species and sensitivity to small sample sizes limit the application of historical records in natural history collections as well as conventional species distribution modelling algorithms to infer past distributions of species.

This study used molecular data as an alternative and objective approach to reconstruct the historical distribution ranges of four stream fishes from the Breede River system in the Cape Fold Ecoregion, a global hotspot of imperilled endemic freshwater biodiversity in southern Africa.

The study used 249 occurrence records and 208 mitochondrial cytochrome b sequences to reconstruct the potential historical ranges of four taxa: Galaxias sp. ‘zebratus nebula', Galaxias sp. ‘zebratus Riviersonderend', Pseudobarbus sp. ‘burchelli Breede' and Pseudobarbus skeltoni.

All four taxa historically had broader distribution ranges across the Breede River system before human impacts, but they have suffered severe attrition as the main‐stem populations have been extirpated.

The severe decline in the historical ranges of these four taxa is a result of multiple impacts, particularly hydrological modification, habitat degradation and the introduction of non‐native species, which are also global challenges for freshwater ecosystems.

The approach presented in this study has great potential for reconstructing historical ranges of stream‐dwelling taxa from disparate regions where fragmentation has resulted from human‐mediated impacts. This information is crucial for identifying appropriate conservation strategies such as river rehabilitation and eradication of non‐native species, as well as guiding reintroductions and informing assisted gene flow where these are deemed necessary interventions.
Optimization of dietary RNA interference delivery to western flower thrips Frankliniella occidentalis and onion thrips Thrips tabaci
Authors: Andongma Awawing A. , Greig Carolyn , Dyson Paul J. , Flynn Natasha , Whitten Miranda M. A.
Published: November 2019

In insect reverse genetics, dietary delivery of interfering RNAs is a practical approach in nonmodel species, such as thrips, whose small size, and feeding behavior restricts the use of other delivery methods. In a laboratory context, an unsuitable diet could confound the interpretation of an RNA interference (RNAi) phenotype, however well‐formulated artificial diets can minimize experimental variability, reduce the need for insect handling, and can further be used for roles, such as delivering double‐strand RNA (dsRNA)‐expressing recombinant bacteria. In this study, artificial diets for oral delivery of dsRNA were developed for two important pest thrips species, western flower thrips (Frankliniella occidentalis) and onion thrips (Thrips tabaci), with the goal of (a) stimulating feeding behavior, (b) supporting optimal growth rates of dsRNA‐expressing symbiotic bacteria, and (c) nutritionally supporting the thrips for sufficient periods to observe RNAi phenotypes. The efficacy of artificial diets for ingesting “naked” dsRNA or dsRNA‐expressing symbionts and dsRNA delivery via host plant uptake was evaluated. Compared with previously published diet formulations, new combinations based on tryptone, yeast, and soy were superior for enhancing feeding and longevity. However, simply adding “naked” dsRNA to an artificial diet was an unreliable form of RNAi delivery in our hands due to dsRNA degradation. Delivery via host plants was more successful, and the new diet formulation was suitable for symbiont‐mediated dsRNA delivery, which we believe is the most convenient approach for large‐scale knockdown experiments. This study, therefore, provides alternative methodologies for thrips rearing, dietary RNAi delivery, and insights into the challenges of performing dietary RNAi in nonmodel insects.
Integrated Transcriptome Analyses Revealed Key Target Genes in Mouse Models of Autism
Authors: Duan Weicheng , Wang Kang , Duan Yijie , Chu Xufeng , Ma Ruoyun , Hu Ping , Xiong Bo
Published: November 2019

Genetic mutations are the major pathogenic factor of Autism Spectrum Disorder (ASD). In recent years, more and more ASD risk genes have been revealed, among which there are a group of transcriptional regulators. Considering the similarity of the core clinical phenotypes, it is possible that these different factors may regulate the expression levels of certain key targets. Identification of these targets could facilitate the understanding of the etiology and developing of novel diagnostic and therapeutic methods. Therefore, we performed integrated transcriptome analyses of RNA‐Seq and microarray data in multiple ASD mouse models and identified a number of common downstream genes in various brain regions, many of which are related to the structure and function of the synapse components or drug addiction. We then established protein–protein interaction networks of the overlapped targets and isolated the hub genes by 11 algorithms based on the topological structure of the networks, including Sdc4, Vegfa, and Cp in the Cortex‐Adult subgroup, Gria1 in the Cortex‐Juvenile subgroup, and Kdr, S1pr1, Ubc, Grm2, Grin2b, Nrxn1, Pdyn, Grin3a, Itgam, Grin2a, Gabra2, and Camk4 in the Hippocampus‐Adult subgroup, many of which have been associated with ASD in previous studies. Finally, we cross compared our results with human brain transcriptional data sets and verified several key candidates, which may play important role in the pathology process of ASD, including SDC4, CP, S1PR1, UBC, PDYN, GRIN2A, GABRA2, and CAMK4. In summary, by integrated bioinformatics analysis, we have identified a series of potentially important molecules for future ASD research. Autism Res 2020, 13: 352–368. © 2019 International Society for Autism Research, Wiley Periodicals, Inc.

Lay Summary

Abnormal transcriptional regulation accounts for a significant portion of Autism Spectrum Disorder. In this study, we performed transcriptome analyses of mouse models to identify common downstream targets of transcriptional regulators involved in ASD. We identified several recurrent target genes that are close related to the common pathological process of ASD, including SDC4, CP, S1PR1, UBC, PDYN, GRM2, NRXN1, GRIN3A, ITGAM, GRIN2A, GABRA2, and CAMK4. These results provide potentially important targets for understanding the molecular mechanism of ASD.
Multifunctionalization of Indoles: Synthesis of 3‐Iodo‐2‐sulfonyl Indoles
Authors: Park Hyowon , Bae Junryeol , Son Soobin , Jang Hye‐Young
Published: November 2019

The selective multifunctionalization of indoles by using thiosulfonates, trimethyl sulfoxonium iodide (Me3SOI), and H2O2 was studied. The reaction of thiosulfonates with Me3SOI and H2O2 produced sulfonyl radicals and an iodination reagent, both of which were incorporated in indoles to form 3‐iodo‐2‐sulfonyl indoles under carefully controlled conditions. The related reaction mechanism and the substrate scope of 3‐iodo‐2‐sulfonyl indoles are presented.
An LC–MS/MS method for determination of O6‐benzylguanine and its metabolite O6‐benzyl‐8‐oxoguanine in human plasma
Authors: Mannem Chandana , Xu Yan
Published: November 2019

O6‐benzylguanine (O6BG) is an inhibitor of O6‐alkylguanine‐DNA alkyltransferase (AGT). It binds to AGT by transferring its benzyl moiety to the cysteine residue at the active site of the enzyme. O6BG synergizes the cytotoxic effects of alkylating agents by halting AGT‐mediated DNA repair. O6‐benzyl‐8‐oxoguanine (8‐oxo‐O6BG) is a metabolite of O6BG, which is an equally potent inhibitor of AGT. In this work, we report the development and validation of an LC–MS/MS method for simultaneous determination of O6BG and 8‐oxo‐O6BG in human plasma. O6BG and 8‐oxo‐O6BG along with the analog internal standard, pCl‐O6BG, were extracted from alkalinized human plasma by liquid–liquid extraction using ethyl acetate, dried under nitrogen and reconstituted in the mobile phase. Reverse‐phase chromatographic separation was achieved using isocratic elution with a mobile phase containing 80% acetonitrile and 0.05% formic acid in water at a flow rate of 0.600 ml/min. Quantification was performed using multiple‐reaction‐monitoring mode with positive ion‐spray ionization. The linear calibration ranges of the method for O6BG and 8‐oxo‐O6BG were 1.25–250 ng/ml and 5.00–1.00 × 103 ng/ml, respectively, with acceptable assay accuracy, precision, recovery and matrix factor. This method was applied to the measurement of O6BG and 8‐oxo‐O6BG in patient plasma samples from a prior phase I clinical trial.
Validation of l‐Tellurienylalanine as a Phenylalanine Isostere
Authors: Vurgun Nesrin , Nitz Mark
Published: November 2019

Mass cytometry (MC) and imaging mass cytometry (IMCTM) have emerged as important tools for the study of biological heterogeneity. We recently demonstrated the use of l‐2‐tellurienylalanine (TePhe), a mimic of phenylalanine (Phe), as an MC‐ and IMC‐compatible protein synthesis reporter. In this work, the biochemical similarity of TePhe and its cognate analogue, Phe, are examined in the context of the RNase S complex. Isothermal titration calorimetry studies show that incorporation of TePhe preserves the interaction of S‐peptide with S‐protein, and the dissociation constants for the interaction of the Phe and TePhe peptides are within a factor of two. The resulting RNase S complex is catalytically active without significant alterations in the enzyme's kinetic parameters. Furthermore, circular dichroism spectroscopy does not reveal any changes to the secondary structure of TePhe‐substituted RNase S. These findings provide strong evidence that TePhe functions as a Phe isostere in the context of a folded protein. It is anticipated that incorporation of TePhe into peptides or peptidomimetic scaffolds will enable facile generation of MC and IMCTM probes.
Spontaneous reduction of a minimally complex cyst mimicking a renal cancer
Authors: Cicero Giuseppe , Blandino Alfredo , Italiano Fabio , Micalizzi Martina Francesca , Mazziotti Silvio
Published: November 2019

Renal cyst shrinkage is a rare finding. Since the collapsed cystic walls may mimic soft tissue components, this scenario has to be taken into account in the differential diagnosis of benign and malignant renal cysts.
Experimental and CFD Investigations of Biomass Thermochemical Conversion: Fundamental Mechanisms, Practical Application, and Advanced Design
Authors: Xiong Qingang , Hong Kun , Shu Shuli
Published: November 2019

No abstract.
Spin–Orbit Charge‐Transfer Intersystem Crossing (ISC) in Compact Electron Donor–Acceptor Dyads: ISC Mechanism and Application as Novel and Potent Photodynamic Therapy Reagents
Authors: Wang Zhijia , Ivanov Mikhail , Gao Yuting , Bussotti Laura , Foggi Paolo , Zhang Huimin , Russo Nino , Dick Bernhard , Zhao Jianzhang , Di Donato Mariangela , Mazzone Gloria , Luo Liang , Fedin Matvey
Published: November 2019

Spin–orbit charge‐transfer intersystem crossing (SOCT‐ISC) is useful for the preparation of heavy atom‐free triplet photosensitisers (PSs). Herein, a series of perylene‐Bodipy compact electron donor/acceptor dyads showing efficient SOCT‐ISC is prepared. The photophysical properties of the dyads were studied with steady‐state and time‐resolved spectroscopies. Efficient triplet state formation (quantum yield ΦT=60 %) was observed, with a triplet state lifetime (τT=436 μs) much longer than that accessed with the conventional heavy atom effect (τT=62 μs). The SOCT‐ISC mechanism was unambiguously confirmed by direct excitation of the charge transfer (CT) absorption band by using nanosecond transient absorption spectroscopy and time‐resolved electron paramagnetic resonance (TREPR) spectroscopy. The factors affecting the SOCT‐ISC efficiency include the geometry, the potential energy surface of the torsion, the spin density for the atoms of the linker, solvent polarity, and the energy matching of the 1CT/3LE states. Remarkably, these heavy atom‐free triplet PSs were demonstrated as a new type of efficient photodynamic therapy (PDT) reagents (phototoxicity, EC50=75 nm), with a negligible dark toxicity (EC50=78.1 μm) compared with the conventional heavy atom PSs (dark toxicity, EC50=6.0 μm, light toxicity, EC50=4.0 nm). This study provides in‐depth understanding of the SOCT‐ISC, unveils the design principles of triplet PSs based on SOCT‐ISC, and underlines their application as a new generation of potent PDT reagents.
Establishing Radiolanthanum Chemistry for Targeted Nuclear Medicine Applications
Authors: Aluicio‐Sarduy Eduardo , Thiele Nikki A. , Martin Kirsten E. , Vaughn Brett A. , Devaraj Justin , Olson Aeli P. , Barnhart Todd E. , Wilson Justin J. , Boros Eszter , Engle Jonathan W.
Published: November 2019

We report the first targeted nuclear medicine application of the lanthanum radionuclides 132/135La. These isotopes represent a matched pair for diagnosis via the positron emissions of 132La and therapy mediated by the Auger electron emissions of 135La. We identify two effective chelators, known as DO3Apic and macropa, for these radionuclides. The 18‐membered macrocycle, macropa, bound 132/135La with better molar activity than DO3Apic under similar conditions. These chelators were conjugated to the prostate‐specific membrane antigen (PSMA)‐targeting agent DUPA to assess the use of radiolanthanum for in vivo imaging. The 132/135La‐labeled targeted constructs showed high uptake in tumor xenografts expressing PSMA. This study validates the use of these radioactive lanthanum isotopes for imaging applications and motivates future work to assess the therapeutic effects of the Auger electron emissions of 135La.
Geometry and Temperature Chaos in Mixed Spherical Spin Glasses at Low Temperature: The Perturbative Regime
Authors: Arous Gérard Ben , Subag Eliran , Zeitouni Ofer
Published: November 2019

We study the Gibbs measure of mixed spherical p‐spin glass models at low temperature, in (part of) the 1‐RSB regime, including, in particular, models close to pure in an appropriate sense. We show that the Gibbs measure concentrates on spherical bands around deep critical points of the (extended) Hamiltonian restricted to the sphere of radius , where is the rightmost point in the support of the overlap distribution. We also show that the relevant critical points are pairwise orthogonal for two different low temperatures. This allows us to explain why temperature chaos occurs for those models, in contrast to the pure spherical models. © 2019 Wiley Periodicals, Inc.
Clustering‐Triggered Efficient Room‐Temperature Phosphorescence from Nonconventional Luminophores
Authors: Zheng Shuyuan , Hu Taiping , Bin Xin , Wang Yunzhong , Yi Yuanping , Zhang Yongming , Yuan Wang Zhang
Published: November 2019

Pure organic room‐temperature phosphorescence (RTP) and luminescence from nonconventional luminophores have gained increasing attention. However, it remains challenging to achieve efficient RTP from unorthodox luminophores, on account of the unsophisticated understanding of the emission mechanism. Herein, we propose a strategy to realize efficient RTP in nonconventional luminophores through incorporation of lone pairs together with clustering and effective electronic interactions. The former promotes spin‐orbit coupling and boosts the consequent intersystem crossing, whereas the latter narrows energy gaps and stabilizes the triplets, thus synergistically affording remarkable RTP. Experimental and theoretical results of urea and its derivatives verify the design rationale. Remarkably, RTP from thiourea solids with unprecedentedly high efficiency of up to 24.5 % is obtained. Further control experiments testify the crucial role of through‐space delocalization on the emission. These results will spur the future fabrication of nonconventional phosphors and advance the understanding of the underlying emission mechanism.
Automated Growth of Si1−xGex Single Crystals with Constant Axial Gradient by Czochralski Technique
Authors: Abrosimov Nikolay V. , Kurlov Vladimir N. , Schewski Robert , Winkler Jan
Published: November 2019

This contribution presents the growth of Si1−xGex crystals with constant gradient of composition for X‐ray or γ‐ray diffraction optics using automated control of the crystal shape during the growth process. The key idea is to achieve a constant concentration gradient by continuously decreasing the crystal diameter during the main crystal growth phase. For this purpose a concept has been developed for a proper planning of the radius trajectory matching all technological requirements. Si1−xGex single crystals with constant gradients between 0.10 and 0.16 at% cm−1 have been grown using an automated control system.
The Limits of Three‐Dimensionality: Systematic Assessment of Effective Anode Macrostructure Dimensions for Mixed‐Culture Electroactive Biofilms
Authors: Moß Christopher , Behrens Andreas , Schröder Uwe
Published: November 2019

This study analyzes the biofilm growth and long‐term current production of mixed‐culture, electrochemically active biofilms (EABs) on macrostructured electrodes under low‐shear‐force conditions. The channel dimensions were altered systematically in the range 400 μm to 2 mm, and the channel heights were varied between 1 and 4 mm to simulate macrostructures of different scales. Electrodes with finer‐structured surfaces produced higher current densities in the short term owing to their large surface area but were outperformed in the long term because the accumulation of biomass led to limitations of mass transfer into the structures. The best long‐term performance was observed for electrodes with channel dimensions of 1×4 mm, which showed no significant decrease in performance in the long term. Channels with a diameter of 400 μm were overgrown by the biofilm, which led to a transition from 3 D to 2 D behavior, indicating that structures of this scale might not be suitable for long‐term operation under low‐shear‐stress conditions.
Evolutionary impacts differ between two exploited populations of northern bottlenose whale (Hyperoodon ampullatus)
Authors: Feyrer Laura Joan , Bentzen Paul , Whitehead Hal , Paterson Ian G. , Einfeldt Anthony
Published: November 2019

Interpretation of conservation status should be informed by an appreciation of genetic diversity, past demography, and overall trends in population size, which contribute to a species' evolutionary potential and resilience to genetic risks. Low genetic diversity can be symptomatic of rapid demographic declines and impose genetic risks to populations, but can also be maintained by natural processes. The northern bottlenose whaleHyperoodon ampullatushas the lowest known mitochondrial diversity of any cetacean and was intensely whaled in the Northwest Atlantic over the last century, but whether exploitation imposed genetic risks that could limit recovery is unknown. We sequenced full mitogenomes and genotyped 37 novel microsatellites for 128 individuals from known areas of abundance in the Scotian Shelf, Northern and Southern Labrador, Davis Strait, and Iceland, and a newly discovered group off Newfoundland. Despite low diversity and shared haplotypes across all regions, both markers supported the Endangered Scotian Shelf population as distinct from the combined northern regions. The genetic affinity of Newfoundland was uncertain, suggesting an area of mixing with no clear population distinction for the region. Demographic reconstruction using mitogenomes suggests that the northern region underwent population expansion following the last glacial maximum, but for the peripheral Scotian Shelf population, a stable demographic trend was followed by a drastic decline over a temporal scale consistent with increasing human activity in the Northwest Atlantic. Low connectivity between the Scotian Shelf and the rest of the Atlantic likely compounded the impact of intensive whaling for this species, potentially imposing genetic risks affecting recovery of this population. We highlight how the combination of historical environmental conditions and modern exploitation of this species has had very different evolutionary impacts on structured populations of northern bottlenose whales across the western North Atlantic.
Ruthenium(II) Catalysed Highly Regioselective C‐3 Alkenylation of Indolizines and Pyrrolo[1,2‐a]quinolines
Authors: Jadhav Pankaj Pandit , Kahar Nilesh Machhindra , Dawande Sudam Ganpat
Published: November 2019

Discovered the Ruthenium(II) catalysed highly stereo‐ and regioselective protocol for the oxidative C‐3 alkenylation of indolizines and pyrrolo[1,2‐a]quinolines. The methodology represents the first example for the directing group assisted C–C bond formation reaction of the indolizines. Under mild reaction conditions, this method provides an ample substrate scope to produce C‐3 alkenyl indolizines in excellent to moderate yields. However, pyrrolo[1,2‐a]quinolines underwent alkenynation at elevated temperature to furnish C‐3 alkenyl derivatives. The functionalized indolizines were selectively reduced to obtain their saturated derivatives.
Proline Derived Bicyclic Derivatives through Metal Catalysed Cyclisations of Allenes: Synthesis of Longamide B, Stylisine D and their Derivatives
Authors: Jovanovic Milos , Petkovic Milos , Jovanovic Predrag , Simic Milena , Tasic Gordana , Eric Slavica , Savic Vladimir
Published: November 2019

Annulations of allene‐substituted proline derivatives promoted by transition metals have been investigated as a general way to access bicyclic structures with a bridgehead nitrogen. Two processes, Pd‐ and Ag‐catalysed cyclisations, have been employed complementary to control the substitution pattern of the product. The investigated methodologies afforded the bicyclic derivatives in comparable yields, while Ag‐catalysis showed higher level of diastereoselectivity. Both processes have been utilized in the synthesis of naturally occurring pyrroles longamide B, stylisine D and their derivatives.
The Hofmeister Anion Effect on Ionophore‐based Ion‐selective Nanospheres Containing Solvatochromic Dyes
Authors: Li Xiaoang , Zhai Jingying , Xie Xiaojiang
Published: November 2019

Recently reported ionophore‐based ion‐selective nanospheres contained pH‐independent and positively charged solvatochromic dyes. Here, we evaluate systematically the effect of anions to the fluorescence response of the nanospheres. The anion interference was found significant for anion concentrations above 10 mM. The sensor responses in the presence of various anion background was studied. While target ion (K+) causes the fluorescence of the nanospheres to decrease, increasing anion background also leads to lower fluorescence intensity. Lipophilic anions such as ClO4−, SCN−, and I− exhibited much more interference than hydrophilic anions (e. g., NO3−, Cl−, F−, SO42−). The trend of the anion interference followed the Hofmeister series. A theoretical model was also demonstrated based on anion adsorption on the surface of the nanospheres.
Mass transfer of a neutral solute in polyelectrolyte grafted soft nanochannel with porous wall
Authors: Roy Debashis , Bhattacharjee Saikat , De Sirshendu
Published: November 2019

A soft nanochannel involves a soft interface that contains a polyelectrolyte layer (PEL) sandwiched between a rigid surface and a bulk electrolyte solution. Mass transfer of a neutral solute in a combined electroosmotic and pressure driven flow through a polyelectrolyte grafted charged nanochannel with porous wall is presented in this work. Assuming the PEL as fixed charged layer and PEL‐electrolyte interface as a semi‐penetrable membrane, analytical solutions were obtained for potential distributions (for small wall potential). Velocity profiles were also derived in the same domains, for both inside and outside the PEL. Convective‐diffusive species balance equation was semi‐analytically solved inside the PEL. Expression of length averaged Sherwood number was also obtained and effects of different parameters, namely, drag parameter (α), Debye parameter , and PEL thickness were studied in detail. The variation of permeate concentration and permeation flux across the porous wall was obtained.
One‐step preparation of organic‐inorganic hybrid capsules based on simultaneous gelation and silicification
Authors: Kurayama Fumio , Bahadur Newaz Mohammed , Sato Masahide , Furusawa Takeshi , Suzuki Noboru
Published: November 2019

Enzyme encapsulation within alginate capsules usually suffers from low encapsulation efficiency and leakage of enzyme. In this study, alginate‐aminosilane hybrid capsules with high encapsulation efficiency, good retention and high storage stability of enzyme have been prepared by a novel method, in which viscous solution containing enzyme, calcium chloride as a crosslinker, and 3‐(2‐aminoethylamino)propyltrimethoxysilane as an aminosilane was dripped into alginate solution, facilitating the formation of alginate‐aminosilane hybrid shell at alginate/droplet interface. Results showed that the hybrid capsules could encapsulate formate dehydrogenase with molecular weight of 74 kDa with encapsulation efficiency of 98% and have the ability to protect the enclosed enzyme from denaturation by chaotropic effect of calcium ion. Furthermore, the capsules were reused efficiently for 20 cycles without loss of the enzyme activity. The approach developed in this study could evolve as a generic platform of enzyme immobilization for various biotechnological applications.
Atmospheric Deposition of Coal-Related Pollutants in the Pacific Northwest of the United States from 1950 to 2016
Authors: Sousa Matthew , Benson Bryce , Welty Connor , Price Dylan , Thirkill Ruth , Erickson William , Cummings Mackenzie , Dunnivant Frank M.
Published: November 2019

Coal-related elements are toxic and persistent pollutants that have spread globally since the industrial revolution, mainly from point-source emissions. A sediment core was collected from Deep Lake in northeastern Washington State (USA) by the Washington State Department of Ecology, with the aim of assessing recent changes in atmospheric deposition in the US Pacific Northwest. The core was divided into depth intervals and dated by lead-210. A sample from each cross section was digested and analyzed for toxic metals and metalloids using inductively coupled plasma–mass spectrometry. Data show recent increases in the concentrations of arsenic, barium, selenium, and mercury. Comparison with 1993 US Geological Survey ice core data from the Upper Fremont Glacier in Wyoming (USA), Asian coal consumption data, and weather patterns suggests that pollutant inputs to Deep Lake sediments are the result of coal-burning activities in the Asia–Pacific region. Most notably, mercury deposition in Deep Lake has increased from approximately 20 ppb in 1996 to 9470 ppb in 2014 (an ~400-fold increase), and since 1993 when the ice core was analyzed. Environ Toxicol Chem 2020;39:335–342. © 2019 SETAC