bluuebunny/crossref_metadata_2025 huggingface dataset:
Sex differences in associations between spatial ability and corpus callosum morphology
Authors: Kurth Florian , Spencer Debra , Hines Melissa , Luders Eileen
Published: May 2018

Rotating mental representations of objects is accompanied by widespread bilateral brain activations. Thus, interhemispheric communication channels may play a relevant part when engaging in mental rotation tasks. Indeed, links between mental rotation and dimensions of the corpus callosum—the brain's main commissure system—have been reported. However, existing findings are sparse and inconsistent across studies. Here we set out to further characterize the nature of any such links, including their exact location across the corpus callosum. For this purpose, we applied an advanced image analysis approach assessing callosal thickness at 100 equidistant points in a sample of 38 healthy adults (19 men, 19 women), aged between 22 and 45 years. We detected a sex interaction, with significant structure–performance relationships in women, but not in men. Specifically, better mental rotation performance was linked to a thicker female corpus callosum within regions of the callosal splenium, posterior midbody, and anterior third. These findings may suggest sex differences in problem solving strategies where in women, more than in men, stronger interhemispheric connectivity—especially between occipitoparietal, frontal, and prefrontal regions—is associated with improved task performance. © 2018 Wiley Periodicals, Inc.
Detergent Compatible Extracellular Lipase from Streptomyces cellulosae AU‐10: A Green Alternative for the Detergent Industry
Authors: Boran Rukiye
Published: May 2018

Enzymes can decrease the environmental and economic load of detergent products by reducing the amount of chemicals used in detergents and by allowing washing at ambient temperatures. In this study, Streptomyces cellulosae AU‐10 (GenBank accession number: MG780240) lipase was purified 7.08‐fold with 68% yield using an aqueous 2‐phase system. The Streptomyces sp. AU‐10 lipase showed maximal activity at pH 9.0 and 40 °C. Hundred percent activities were measured in the pH range from 9.0 to 11.0 for 1 h. The enzyme was also highly stable at 30–50 °C. The values of Km and Vmax were calculated as 0.34 mM and 0.83 mM min−1, respectively. The lipase has high hydrolytic activity for olive oil and sunflower oil. The effect of ethylenediamine tetraacetic acid on the enzyme has shown that the lipase is a metalloenzyme. The activity increased in the presence of Fe2+, Cu2+, and various boron compounds. The enzyme has shown a good stability not only with surfactants but also with oxidizing agents. In addition, activities in the presence of Omo, Ariel, Tursil, Pril, and Fairy were measured as 108.8%, 115.6%, 98.35%, 140.4%, and 107.6%, respectively. Considering its remarkable ability, the S. cellulosae AU‐10 lipase can be considered as a potential additive in the detergent industry.
Economic sustainability? Examining the linkages and leakages between agriculture and hotels in Bhutan
Authors: Pratt Stephen , Suntikul Wantanee , Dorji Ugyen
Published: May 2018

Bhutan is known for its approach to high‐value, low‐volume tourism development. Bhutan has been cited as an example of a best case approach to sustainable tourism. However, like other landlocked countries, Bhutan relies heavily on imported goods from neighbouring countries such as India and Thailand, leading to significant economic leakages. This raises the question of how economically sustainable Bhutan's tourism is. This research employs a mixed microeconomic and macroeconomic analysis of linkages and leakages between different sectors in the Bhutanese tourism industry, in particular hotels and agriculture to ascertain the volume and value of these leakages.
Exploring “culturalization” in rural entrepreneurial context through content analysis
Authors: Magliacani Michela , Madeo Elena
Published: May 2018

Knowledge is a critical success factor for achieving a competitive advantage. A broad literature on organizational knowledge process has been provided, but investigations on knowledge creation beyond organizational boundaries are still lacking. This is the reason why the study explores, through the qualitative content analysis, the impact of the rural entrepreneurial context in a regional network project. The text processing and the words frequency explain how the spaces of interaction within the rural pilot cluster were too small, in terms of shared words, for activating a learning process of shared knowledge. The conceptual model that come out from the case study could be grounded to understand the “culturalization” of interorganizational knowledge in other cultural context.
Hillslope degradation in representative Italian areas: Just soil erosion risk or opportunity for development?
Authors: Brandolini Pierluigi , Pepe Giacomo , Capolongo Domenico , Cappadonia Chiara , Cevasco Andrea , Conoscenti Christian , Marsico Antonella , Vergari Francesca , Del Monte Maurizio
Published: May 2018

In recent years, much research have dealt with the impact of human and climate change on the morpho‐evolution of Mediterranean catchments characterized by high ecological and cultural value. In this paper, we speculated how humans can influence hillslope degradation by reviewing the relationships between denudation processes and land use changes in some representative areas located in different Italian regions (i.e., Liguria, Tuscany, Basilicata, and Sicily). The selected study cases are characterized by different climatic and geological features, land use, and land management and can be considered indicative of the hillslope degradation issues that affected the Apennines during the last century. We compared and discussed the main outcomes from previous studies, with the aim of identifying the main drivers leading to hillslope degradation and to shed light on the role of human action. We revealed that hillslope degradation can be mainly related to deforestation for land reclamation, cropland abandonment, and the increase of hazardous rainfall. Moreover, we focused on how human impact can have both positive and negative feedbacks. In some cases (e.g., badlands), the land levelling has produced an initial inhibition of land degradation, whereas after intensive agricultural practices, accelerated soil depletion has occurred, favouring erosion processes. Analogously, terracing controlled erosion as long as the entire terrace system was maintained, but abandoned terraced slopes can increase the magnitude of geo‐hydrological phenomena in response to high‐intensity rainfall. On‐the‐other‐hand, both rural landscape and related erosional landforms can be appreciated as elements of landscape diversity and contribute to tourism development.
A conceptual model of natural land degradation based on regressive pedogenesis in semiarid tropical environments
Authors: Vasu Duraisamy , Tiwary Pramod , Chandran Padikkal , Singh Surendra Kumar , Ray Sanjay Kumar , Butte Pravin , Parhad Vilas
Published: May 2018

Land degradation occurs in all the climatic regions, however, the adverse effects are more pronounced in the semiarid tropical (SAT) environments due to increasing aridity and water scarcity. Though natural processes can also cause land degradation, it is generally attributed to anthropogenic factors. In this study, we elucidate the role of climate and landscape driven soil forming processes in land degradation through a conceptual model. For this, morphological, physical, and chemical properties of the soils occurring in a part of the SAT Deccan Plateau region, India, were characterized. The trend of climatic variables, namely, the mean annual rainfall, potential evapotranspiration, and maximum summer temperature during the last century (1901–2010) showed that the increase in aridity negatively influenced the soil forming processes. The results showed that rainfall variability, temperature, potential evapotranspiration, and hydrological behaviour of the SAT soils were the primary drivers of the soil forming processes and they were identified through examination of the soil variability by factor analysis. The depth distribution of selected indicators (% clay, pH, calcium carbonate, exchangeable sodium percentage, exchangeable magnesium percentage, and hydraulic conductivity) indicated that the current pedogenic processes operating in the SAT environment caused the undesirable modification in soil properties. Through our conceptual model, we discuss the mechanism of the formation of pedogenic carbonate, subsoil sodicity, and subsequent reduction in hydraulic conductivity which leads to the land and vegetation degradation in the SAT environments.
Calcium–sodium exchange equilibria in two soils of Chambal Command Area of Rajasthan, India
Authors: Singh Balendra , Srivastava Prakash Chandra , Shrivastava Manoj
Published: May 2018

Calcium–sodium exchange equilibria were studied at 15 and 25 °C in 2 smectite dominant soils belonging to Typic Haplustalf (Bundi Series) and Typic Pellustert (Chambal series) of Chambal Command Area of Rajasthan (India). These soils had preference for Na+ over Ca2+; however, the soil of Bundi Series at low Na saturation (10%) showed a preference for Ca2+ at lower temperature only. Higher specificity for Na+ in Chambal Series was related to the presence of zeoloites. The relationship between exchangeable sodium ratio and sodium adsorption ratio was nonlinear, and Chambal Series could maintain relatively lower sodium adsorption ratio even at higher exchangeable sodium ratio. Among different calculated selectivity coefficients, Gapon selectivity coefficient (KG) registered the lowest coefficient of variation. The values of thermodynamic equilibrium constant (K) were greater than unity indicating higher preference for Na+, especially in Chambal Series. The Ca↔Na exchange reaction was associated with an increase in the entropy of the system in these soils.
Physiological and transcriptional responses to salt stress in salt‐tolerant and salt‐sensitive soybean (Glycine max[L.] Merr.) seedlings
Authors: Ning Lihua , Kan Guizhen , Shao Hongbo , Yu Deyue
Published: May 2018

Excess salinity is a major environmental threat to agriculture. However, the adaptive mechanisms underlying salt tolerance in soybean (Glycine max[L.] Merr.) remain unclear. The aim of this study was to investigate the differences between salt‐tolerant and salt‐sensitive soybeans in their physiological characteristics and the expression patterns of 8 cation antiporters under salt stress. The inhibitory effects of salt stress on growth and photosynthesis in salt‐sensitive soybean were stronger than those in salt‐tolerant soybean. The concentration of phosphate and most other ions in the seedlings significantly declined under a 150‐mM‐NaCl treatment. Relative K+, Mg2+, and P concentrations were significantly positively correlated with relative net photosynthetic rate.GmNHX1(Glyma.10G158700) andGmNcl1(Glyma.03g171500) had similar expression patterns in the salt‐tolerant and salt‐sensitive cultivars. Furthermore, a significant correlation was present between the transcript levels of these 2 genes and the Na+concentration in soybean leaves. In addition toGmSALT3, which is the major gene in soybean for salt tolerance in previous studies,GmNHX1andGmNcl1may be associated with salt tolerance in soybean to some extent. The salt‐tolerant cultivars in this study maintained higher K+, Mg2+, and P concentrations in the leaf and had higher photosynthetic rates than the salt‐sensitive cultivar did under salt stress. These findings can provide theoretical references for the molecular breeding of salt‐tolerant soybean and the sustainable use of saline soils.
1305 nm Few‐Layer MoTe2‐on‐Silicon Laser‐Like Emission
Authors: Fang Hanlin , Liu Jin , Li Hongji , Zhou Lidan , Liu Lin , Li Juntao , Wang Xuehua , Krauss Thomas F. , Wang Yue
Published: May 2018

The missing piece in the jigsaw of silicon photonics is a light source that can be easily incorporated into the standard silicon fabrication process. Here, silicon laser‐like emission is reported that employs few‐layer semiconducting transition metal dichalogenides of molybdenum ditelluride (MoTe2) as a gain material in a silicon photonic crystal L3 nanocavity. An optically pumped MoTe2‐on‐silicon laser‐like emission at 1305 nm, i.e. in the center of the “O‐band” of optical communications, is demonstrated at room temperature and with a threshold power density of 1.5 kW/cm2. The surprising insight is that, contrary to common understanding, a monolayer MoTe2 is not required to achieve higher efficiency laser‐like operation. Instead, few‐layer MoTe2 offers a higher overlap between the two dimensional (2D) gain material and the optical mode for sufficient gain. The ability to use few‐layer material opens new opportunities for deploying manufacturing methods such as chemical vapor deposition and thereby brings 2D‐on‐silicon devices a step closer to becoming a scalable technology.
Toward the Optimization of a Cr‐V Bimetallic Catalyst for Producing Bimodal Polyethylene: Effect of Vanadium Content and Calcination Temperature
Authors: Liu Bao , Tian Zhou , Jin Yulong , Zhao Ning , Liu Boping
Published: May 2018

This work covers the synthesis of bimodal polyethylene with a SiO2‐supported vanadium‐oxide/silyl‐chromate (Cr‐V) bimetallic catalyst, which is prepared by using the residual hydroxyl groups on the VOx/SiO2 catalyst precursor to support chromium species. The effects of vanadium content and calcination temperature of the support on catalyst activity and polymer properties are investigated in detail. It is found that increasing vanadium content in the Cr‐V catalyst leads to the decline of catalyst activity, while the molecular weight of the resulting polyethylene is raised. On the other hand, the decline of catalytic activity at high vanadium content in the Cr‐V catalyst can be remedied by decreasing the calcination temperature of the support, and the molecular weight of the polymers is reduced at the same time. However, too low a calcination temperature is not beneficial for catalyst activity due to the poisoning effect of the excess hydroxyl groups on the active sites, and this would cause the increase of molecular weight as well.
Mass Production of Functional Amine–Conjugated PAN Nanofiber Mat via Syringeless Electrospinning and CVD
Authors: Moon Seongjun , Park Kyueun , Seo Eunbyeol , Lee Kyung Jin
Published: May 2018

Polymeric nanofiber webs have attained much attention because they can provide high surface area with various functional groups. To obtain the polymeric nanofiber webs, electrospinning is the most attractive method because this can provide the versatility of material selection. However, it is relatively difficult to obtain the nanofiber webs, which have highly reactive functional groups and high mechanical strength with high production rate. Here, the helically probed rotating cylinder (HPRC) system based on syringeless electrospinning and chemical vapor deposition (CVD) is introduced to prepare the polyacrylonitrile (PAN) nanofiber webs, having high functional groups and high mechanical strength in fast production rate. The HPRC system can provide the PAN nanofiber webs in high production rate, and the CVD process can provide high reactive functional groups on the PAN nanofiber. In addition, the nanofiber webs can be applied to diverse potential application fields, which require a high number of functional moieties.
A Very Simple Strategy for Preparing External Stress‐Free Two‐Way Shape Memory Polymers by Making Use of Hydrogen Bonds
Authors: Fan Long Fei , Rong Min Zhi , Zhang Ming Qiu , Chen Xu Dong
Published: May 2018

Development of two‐way shape memory polymers that operate free of external force remains a great challenge. Here, the design criteria for this type of material are proposed, deriving a novel fabrication strategy accordingly, which employs conventional crosslinked polyurethane (PU) containing crystalline poly(ε‐caprolactone) (PCL) as the proof‐of‐concept material. Having been simply trained by stretching and thermal treatment without additional ingredients and chemicals, the PU is coupled with a two‐way shape memory effect. The core advancement of this study lies in the successful conversion of the inherent hydrogen bond network, which is often the easiest to overlook, into an internal stress provider. The temperature‐dependent reversible melting/recrystallization of the crystalline phases elaborately works with the tensed hydrogen bond network, leading to implementation of the two‐way shape memory effect. An average reversible strain of as high as ≈20% along the stretch direction is obtained through cooperation adjustment of chemical crosslinking density, crystallinity, and concentration of hydrogen bonds. Meanwhile, the highest internal tension offered by the hydrogen bond network is determined to be 0.10 MPa. Owing to the great convenience characterized by material selection, preparation, programming, and application, the current work may open up an avenue for production and usage of the smart material.
Ring‐Opening Polymerization of a New Diester Cyclic Dimer of Mandelic and Glycolic Acid: An Efficient Synthesis Method for Derivatives of Amorphous Polyglycolide with High Tg
Authors: Nakajima Hajime , Loos Katja , Ishizu Shinobu , Kimura Yoshiharu
Published: May 2018

In this study, poly(mandelate‐co‐glycolate) (PMG), a modified polyglycolide (PGL), is prepared by ring‐opening polymerization (ROP) of L‐3‐phenyl‐1,4‐dioxane‐2,5‐dione (PDD); the cyclic dimer of biobased mandelic acid and glycolic acid. The resulting polymer shows an increased glass transition temperature (Tg) due to the incorporation of phenyl groups in the chain. High molecular weight PMG is obtained by bulk ROP at 150 °C, and it exhibits a glassy amorphous state with enhanced thermal properties such as a Tg being 35 °C higher than conventional PGL. PDD is also copolymerized with glycolide (GL) and lactide (LA), resulting in poly(mandelate‐co‐glycolate/glycolate) ((P(MG/GL)) with GL and poly(mandelate‐co‐glycolate/lactide) ((P(MG/LA)) with LA. The thermal properties of P(MG/GL) and P(MG/LA) are found to be distinctly different from PMG and conventional PGL and polylactide, and they are tunable with a changing molar ratio of PDD, GL, and LA. Therefore, PDD opens an elegant way to control and tailor the properties of biobased polyesters.
pH‐Responsive Poly(dimethylsiloxane) Copolymer Decorated Magnetic Nanoparticles for Remotely Controlled Oil‐in‐Water Nanoemulsion Separation
Authors: Yang Jing , Loh Xian Jun , Tan Beng Hoon , Li Zibiao
Published: May 2018

A smart and recyclable oil absorber based on pH‐responsive block copolymer modified magnetic nanoparticles is constructed for effective separation of oil‐in‐water emulsions. Superparamagnetic iron(III) oxide (Fe3O4) nanoparticles are designed as the core materials for providing the separation force, and surface modification with poly(4‐vinylpyridine‐b‐dimethyl siloxane‐b‐4‐vinylpyridine) (P4VP‐PDMS‐P4VP) block copolymer is performed to supply switchable oil wettability. The mean hydrodynamic radius of the nanoparticles increases from 43.8 ± 3.6 to 75.2 ± 5.3 nm when the neutral pH is reduced to 3, due to the protonation and subsequent swelling of P4VP segments at lower pH. The nanoparticles show excellent separation performance and can absorb octadecene up to 78.2 times of their own weight, simply by switching the pH of the oil‐in‐water emulsion treated with the nanoparticles and using a magnetic field. The different dipole of P4VP‐PDMS‐P4VP and protonated P4VP‐PDMS‐P4VP, as confirmed by density functional theory calculations, is responsible for the different oil miscibility and wettability of the nanoparticles.
Bioresorbable Microspheres with Surface‐Loaded Nanosilver and Apatite as Dual‐Functional Injectable Cell Carriers for Bone Regeneration
Authors: Wei Pengfei , Yuan Zuoying , Cai Qing , Mao Jianping , Yang Xiaoping
Published: May 2018

Bone defect repair, especially in terms of infection, remains a big challenge in clinical therapy. To meet clinical requirements, the dual‐functional strategy including antibacterial activity and strong osteogenesis effect is a promising approach in bone tissue engineering. In the present study, bioresorbable porous‐structured microspheres are fabricated from amphiphilic block copolymer composed of poly(l‐lactide) and poly(ethyl glycol) blocks. After being surface coated with mussel‐inspired polydopamine, the microspheres are loaded with nanosilver via reduction of silver nitrate and apatite via biomineralization in sequence. The resulting composite microspheres are systematically characterized by in vitro coculturing with rat bone mesenchymal stromal cells and Staphylococcus aureus to evaluate cytotoxicity and antibacterial activity. In vivo evaluation is carried out by filling the composite microspheres into infected cranial defects in a rat model. The primary results indicate that the dual‐purpose microspheres have the capacity to defeat infection while promoting bone regeneration.
Redox‐Responsive Polymer with Self‐Immolative Linkers for the Release of Payloads
Authors: Iamsaard Supitchaya , Seidi Farzad , Dararatana Naruphorn , Crespy Daniel
Published: May 2018

Previous couplings of corrosion inhibitors to redox‐responsive polymers via covalent bonding suffer from several drawbacks. It is presented here novel redox‐responsive polymer‐corrosion inhibitor conjugates that contain self‐immolative linkers in their side chains. Very fast redox‐induced release of tryptamine, a drug and a corrosion inhibitor, is observed after applying a reductive trigger.
Probing the Viscoelastic Property of Pseudo Free‐Standing Conjugated Polymeric Thin Films
Authors: Zhang Song , Ocheje Michael U. , Luo Shaochuan , Ehlenberg Dakota , Appleby Benjamin , Weller Daniel , Zhou Dongshan , Rondeau‐Gagné Simon , Gu Xiaodan
Published: May 2018

The understanding of the structure‐mechanical property relationship for semiconducting polymers is essential for the application of flexible organic electronics. Herein pseudo free‐standing tensile testing, a technique that measures the mechanical property of thin films floating on the surface of water, is used to obtain the stress–strain behaviors of two semiconducting polymers, poly(3‐hexylthiophene) (P3HT) and poly(2,5‐bis(2‐decyltetradecyl)‐3,6‐di(thiophen‐2‐yl)diketopyrrolo[3,4‐c]pyrrole‐1,4‐dione‐alt‐thienovinylthiophene (DPP‐TVT) donor–acceptor (D–A) polymer. To our surprise, DPP‐TVT shows similar viscoelastic behavior to P3HT, despite DPP‐TVT possessing a larger conjugated backbone and much higher charge carrier mobility. The viscoelastic behavior of these polymers is due to sub room temperature glass transition temperatures (Tg), as shown by AC chip calorimetry. These results provide a comprehensive understanding of the viscoelastic properties of conjugated D–A polymers by thickness‐dependent, strain rate dependent, hysteresis tests, and stress‐relaxation tests, highlighting the importance of Tg for designing intrinsically stretchable conjugated polymers.
Softening and Shape Morphing of Stiff Tough Hydrogels by Localized Unlocking of the Trivalent Ionically Cross‐Linked Centers
Authors: Wang Jiahui , Li Tianzhen , Chen Fan , Zhou Dan , Li Baijia , Zhou Xiaohu , Gan Tiansheng , Handschuh‐Wang Stephan , Zhou Xuechang
Published: May 2018

The mechanical properties (e.g., stiffness, stretchability) of prefabricated hydrogels are of pivotal importance for diverse applications in tissue engineering, soft robotics, and medicine. This study reports a feasible method to fabricate ultrasoft and highly stretchable structures from stiff and tough hydrogels of low stretchability and the application of these switchable hydrogels in programmable shape‐morphing systems. Stiff and tough hydrogel structures are first fabricated by the mechanical strengthening of Ca2+‐alginate/polyacrylamide tough hydrogels by addition of Fe3+ ions, which introduces Fe3+ ionically cross‐linked centers into the Ca2+ divalent cross‐linked hydrogel, forming an additional and much less flexible trivalent ionically cross‐linked network. The resulting stiff and tough hydrogels are exposed to an L‐ascorbic acid (vitamin C, VC) solution to rapidly reduce Fe3+ to Fe2+. As a result, flexible divalent ionically cross‐linked networks are formed, leading to swift softening of the stiff and tough hydrogels. Moreover, localized stiffness variation of the tough hydrogels can be realized by precise patterning of the VC solution. To validate this concept, sequential steps of VC patterning are carried out for local tuning of the stiffness of the hydrogels. With this strategy, localized softening, unfolding, and sequential folding of the tough hydrogels into complex 3D structures is demonstrated.
Ion‐Conductive and Thermal Properties of a Synergistic Poly(ethylene carbonate)/Poly(trimethylene carbonate) Blend Electrolyte
Authors: Li Zhenguang , Mogensen Ronnie , Mindemark Jonas , Bowden Tim , Brandell Daniel , Tominaga Yoichi
Published: May 2018

Electrolytes comprising poly(ethylene carbonate) (PEC)/poly(trimethylene carbonate) (PTM C) with lithium bis(trifluoromethane sulfonyl)imide (LiTFSI) are prepared by a simple solvent casting method. Although PEC and PTMC have similar chemical structures, they are immiscible and two glass transitions are present in the differential scanning calorimetry (DSC) measurements. Interestingly, these two polymers change to miscible blends with the addition of LiTFSI, and the ionic conductivity increases with increasing lithium salt concentration. The optimum composition of the blend electrolyte is achieved at PEC6PTMC4, with a conductivity as high as 10−6 S cm−1 at 50 °C. This value is greater than that for single PEC‐ and PTMC‐based electrolytes. Moreover, the thermal stability of the blend‐based electrolytes is improved as compared to PEC‐based electrolytes. It is clear that the interaction between CO groups and Li+ gives rise to a compatible amorphous phase of PEC and PTMC.
Amine‐Triggered Dopamine Polymerization: From Aqueous Solution to Organic Solvents
Authors: Liu Xinghuan , Kang Junjie , Wang Yiqing , Li Wei , Guo Heling , Xu Liang , Guo Xuhong , Zhou Feng , Jia Xin
Published: May 2018

Dopamine (DA) polymerization has received significant attention in many fields, however, almost all of the works are limited to aqueous solution and hamper its wide application. This paper reports that amines can trigger DA polymerization by capturing the H+ from DA hydrochloride and intermediates to accelerate the generation of radical species in water or organic solvents. Increasing concentration and decreasing pKb of amines cause the reaction equilibrium to shift toward the product polydopamine (PDA). Water‐soluble and easily‐removable Na2SO4 nanowires and NaCl cubes can be used as templates to prepare different morphologies of hollow PDA structures by DA polymerization in ethanol solution. The carbonization production of PDA nanotubes at 900 °C (PDNC‐900) is obtained and demonstrates electrochemical activity in the oxygen reduction reaction that is comparable to that of Pt/C.
TEMPO Driven Mild and Modular Route to Functionalized Microparticles
Authors: Hafeez Sumbul , Barner Leonie , Nebhani Leena
Published: May 2018

The synthesis of crosslinked polymeric microspheres (3.8–15.0 µm) via (2,2,6,6‐tetramethylpiperidin‐1‐yl)oxyl (TEMPO) initiated thiol‐ene dispersion polymerization under ambient conditions is reported for the first time. The initiating ability of TEMPO for the thiol‐ene reaction is validated by electron paramagnetic resonance (EPR) and 1H nuclear magnetic resonance (NMR) spectroscopy on model reactions between 1‐octadecanethiol and two electron deficient enes, n‐butylacrylate and divinyl sulfone. Critically, the TEMPO resonance observed in the EPR spectra decreases with time when TEMPO is mixed with thiol and an electron deficient ene. The 1H NMR spectra demonstrate formation of up to 90% of thioether under ambient conditions. Based on these model reactions, a variety of crosslinked polymeric microspheres are synthesized with excellent morphological stability using poly(vinyl pyrrolidone) as surfactant. The ability of the microspheres for a second TEMPO initiated thiol‐ene reaction is demonstrated by the ligation of fluorescein‐5‐maleimide (an ene) to the microspheres' surface containing excess of thiol functionality and by ligation of cysteine (containing a thiol group) to the microspheres' surface containing an excess of ene functionality. The synthesized polymeric microspheres are characterized using scanning electron microscopy, differential scanning calorimetry, Fourier‐transform infrared spectroscopy, zeta potential, and X‐ray photoelectron spectroscopy.
Intramolecular Copper‐Containing Hyperbranched Polytriazole Assemblies for Label‐Free Cellular Bioimaging and Redox‐Triggered Copper Complex Delivery
Authors: Ban Qingfu , Du Junjie , Sun Wen , Chen Jianxin , Wu Si , Kong Jie
Published: May 2018

Intramolecular Cu‐containing amphiphilic hyperbranched polytriazoles are purposefully designed and synthesized via a Cu(I)‐catalyzed azide–alkyne cycloaddition (CuAAC) reaction, and are self‐assembled into spherical assemblies. Based on the metal coordination ability of triazole groups, the copper catalyst can be intramolecularly coordinated with triazole groups in the CuAAC, producing the copper‐triazole coordination polyprodrugs. Unexpectedly, the amphiphilic hyperbranched polytriaozle assemblies can also be applied as fluorescent nanoprobes with aggregation‐induced emission enhancement. The cellular uptake verifies their functional application for cellular bioimaging. Furthermore, the results of cell viability indicate that the mPEG‐hb‐S‐S‐PTAs assemblies are effective copper delivery systems for cancer therapy by releasing the anticancer copper‐triazole coordination complexes. Therefore, the amphiphilic hyperbranched polytriazoles may have very promising applications in complex copper delivery and label‐free cellular bioimaging.
Tunable, Quantitative Fenton‐RAFT Polymerization via Metered Reagent Addition
Authors: Nothling Mitchell D. , McKenzie Thomas G. , Reyhani Amin , Qiao Greg G.
Published: May 2018

A continuous supply of radical species is a key requirement for activating chain growth and accessing quantitative monomer conversions in reversible addition‐fragmentation chain transfer (RAFT) polymerization. In Fenton‐RAFT, activation is provided by hydroxyl radicals, whose indiscriminate reactivity and short‐lived nature poses a challenge to accessing extended polymerization times and quantitative monomer conversions. Here, an alternative Fenton‐RAFT procedure is presented, whereby radical generation can be finely controlled via metered dosing of a component of the Fenton redox reaction (H2O2) using an external pumping system. By limiting the instantaneous flux of radicals and ensuring sustained radical generation over tunable time periods, metered reagent addition reduces unwanted radical “wasting” reactions and provides access to consistent quantitative monomer conversions with high chain‐end fidelity. Fine tuning of radical concentration during polymerization is achieved simply via adjustment of reagent dose rate, offering significant potential for automation. This modular strategy holds promise for extending traditional RAFT initiation toward more tightly regulated radical concentration profiles and affords excellent prospects for the automation of Fenton‐RAFT polymerization.
Macroscopic Supramolecular Assembly through Electrostatic Interactions Based on a Flexible Spacing Coating
Authors: Zhang Qian , Liu Chongxian , Ju Guannan , Cheng Mengjiao , Shi Feng
Published: May 2018

Macroscopic supramolecular assembly (MSA) is a recent advance in supramolecular chemistry that involves associating large building blocks with a size larger than 10 µm through noncovalent interactions. However, until now the applicable material system is rather limited to hydrogels, and MSA of rigid materials with supramolecular interactions widely used in molecular assembly has rarely been reported due to the difficulty in achieving multivalency between rigid surfaces. Herein, the concept of flexible spacing coating is applied with highly flowable properties, and the electrostatic‐interaction‐driven MSA of relatively rigid polydimethylsiloxane building blocks is demonstrated. With the flexible spacing coating of a polyelectrolyte multilayer, the oppositely charged rigid building blocks can realize MSA under shaking in water for 5 min. The major contribution of the electrostatic interaction is confirmed by both qualitative controlled MSA experiments in other solvents, disassembly in ionic solution and quantitative results with an in situ force measurement method.
Synergy between Electrochemical ATRP and RAFT for Polymerization at Low Copper Loading
Authors: Wang Yi , Fantin Marco , Matyjaszewski Krzysztof
Published: May 2018

A dual‐concurrent atom transfer radical polymerization/reversible addition‐fragmentation chain‐transfer (ATRP/RAFT) system is used to control a radical polymerization by electrochemical reduction of small amount of copper complexes in the presence of a chain transfer agent (CTA). Electrochemical ATRP conditions provide a continuous supply of radicals, while the CTA aids the control over molecular weight and dispersity of poly(n‐butyl acrylate), even in the presence of low ppm amounts of catalyst. The polymerization could be turned “on” and “off” by shifting electrolysis potential. With as low as 10 ppm of Cu catalyst, addition of only 2% CTA (with respect to the ATRP initiator) improves control by decreasing dispersity from Ð = 1.41 to Ð = 1.25.
Effect of the Z‐ and Macro‐R‐Group on the Thermal Desulfurization of Polymers Synthesized with Acid/Base “Switchable” Dithiocarbamate RAFT Agents
Authors: Stace Sarah J. , Fellows Christopher M. , Moad Graeme , Keddie Daniel J.
Published: May 2018

Thermolysis is examined as a method for complete desulfurization of reversible addition‐fragmentation chain transfer (RAFT)‐synthesized polymers prepared with acid/base “switchable” N‐methyl‐N‐pyridyldithiocarbamates [RS2CZ or RS2CZH+]. Macro‐RAFT agents from more activated monomers (MAMs) (i.e., styrene (St), N‐isopropylacrylamide (NIPAm), and methyl methacrylate (MMA)) with RS2CZH+ and less activated monomers (LAMs) (i.e., vinyl acetate (VAc) and N‐vinylpyrolidone (NVP)) with RS2CZ are prepared by RAFT polymerization and analyzed by thermogravimetric analysis. In all cases, a mass loss consistent with loss of the end group (ZCS2H) is observed at temperatures lower than, and largely discrete from, that required for further degradation of the polymer. The temperatures for end group loss and the new end groups formed are strongly dependent on the identity of the R(P)n and the state of the pyridyl Z group; increasing in the series poly(MMA) < poly(St) ∼ poly(NIPAm) << poly(VAc) ∼ poly(NVP) for S2CZ and poly(MMA) < poly(St) ∼ poly(NIPAm) for S2CZH+. Clean end group removal is possible for poly(St) and poly(NVP). For poly(NIPAm), the thiocarbonyl chain end is removed, but the end group identity is less certain. For poly(MMA) and poly(VAc), some degradation of the polymer accompanies end group loss under the conditions used and further refinement of the process is required.
Exosomal miR‐423‐5p targets SUFU to promote cancer growth and metastasis and serves as a novel marker for gastric cancer
Authors: Yang Huan , Fu Hailong , Wang Bo , Zhang Xu , Mao Jiahui , Li Xia , Wang Mei , Sun Zixuan , Qian Hui , Xu Wenrong
Published: May 2018

Exosomes are critically involved in tumor growth, metastasis, and therapy resistance. Exosomes have the potential to be utilized as cancer biomarkers. In this study, we aimed to explore the roles and clinical values of exosomal miRNAs in gastric cancer. We found that the concentration of exosomes was significantly higher in the serum of gastric cancer patients and the culture supernatants of gastric cancer cells than that in healthy volunteers and gastric mucosa epithelial cells. In particular, miR‐423‐5p was elevated in the serum exosomes of gastric cancer patients, and the level of exosomal miR‐423‐5p was remarkably correlated with lymph node metastasis. High level of exosomal miR‐423‐5p was associated with poor outcome in gastric cancer patients. MiR‐423‐5p enriched exosomes could be internalized into gastric cancer cells, which enhanced cell proliferation and migration both in vitro and in vivo. Mechanistically, miR‐423‐5p inhibited the expression of suppressor of fused protein (SUFU) to enhance the proliferation and migration of gastric cancer cells. The expression levels of SUFU were significantly decreased in gastric cancer cells and the tumor tissues of gastric cancer patients. Taken together, our findings indicate that exosomes could deliver miR‐423‐5p to promote cancer growth and metastasis and serum exosomal miR‐423‐5p may serve as a potential marker for gastric cancer diagnosis and prognosis.
Exclusionary practices in two‐sided markets: The effect of radius clauses on competition between shopping centers
Authors: Brühn Tim , Götz Georg
Published: May 2018

We analyze exclusionary conduct of platforms in 2‐sided markets. Motivated by recent antitrust cases, we provide a discussion of the likely positive and normative effects of exclusivity clauses, which prevent tenants from opening outlets in other shopping centers covered by the clause. In a standard 2‐sided market model, we show that exclusivity agreements are especially profitable for the incumbent and detrimental to social welfare if competition is intense between the 2 shopping centers. We argue that the focus of courts on market definition is misplaced in markets determined by competitive bottlenecks.
Overconfidence and disappointment in venture capital decision making: An empirical examination
Authors: Graves Samuel B. , Ringuest Jeffrey
Published: May 2018

We examine the effects of overconfidence in venture capital investing. Overconfidence in financial decision making is a robust, well‐established finding, and its consequences for decisions by equity market investors, startup entrepreneurs, and CEO's of large firms have been comprehensively examined and documented. This paper considers the behavioral consequences of overconfidence by venture capitalists, comparing their anticipated returns to actual average returns. Our primary metric is Bell's disappointment, a measure of the difference between anticipated and actual payoff. We construct both deterministic and stochastic models, based on empirical data. We find that the average venture capitalist will experience substantial disappointment.
Green Tea Liquid Consumption Alters the Human Intestinal and Oral Microbiome
Authors: Yuan Xiaojie , Long Yong , Ji Zhaohua , Gao Jie , Fu Ting , Yan Min , Zhang Lei , Su Haixia , Zhang Weilu , Wen Xiaohui , Pu Zhongshu , Chen Hui , Wang Yufei , Gu Xu , Yan Binyuan , Kaliannan Kanakaraju , Shao Zhongjun
Published: May 2018

Scope

GTPs (green tea polyphenols) exert anti‐CRC (colorectal cancer) activity. The intestinal microbiota and intestinal colonization by bacteria of oral origin has been implicated in colorectal carcinogenesis. GT modulates the composition of mouse gut microbiota harmonious with anticancer activity. Therefore, the effect of green tea liquid (GTL) consumption on the gut and oral microbiome is investigated in healthy volunteers (n = 12).

Methods and results

16S sequencing and phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analysis of both fecal and saliva samples (collected before intervention, after 2 weeks of GTL (400 mL per day) and after a washout period of one week) in healthy volunteers show changes in microbial diversity and core microbiota and difference in clear classification (partial least squares‐discriminant analysis [PLS‐DA]). An irreversible, increased FIR:BAC (Firmicutes to Bacteroidetes ratio), elevated SCFA producing genera, and reduction of bacterial LPS synthesis in feces are discovered in response to GTL. GTL alters the salivary microbiota and reduces the functional pathways abundance relevance to carcinogenesis. Similar bacterial networks in fecal and salivary microbiota datasets comprising putative oral bacteria are found and GTL reduces the fecal levels of Fusobacterium. Interestingly, both Lachnospiraceae and B/E (Bifidobacterium to Enterobacteriacea ratio—markers of colonization resistance [CR]) are negatively associated with the presence of oral‐like bacterial networks in the feces.

Conclusion

These results suggest that GTL consumption causes both oral and gut microbiome alterations.
The genome sequence of a SNP type 3K strain of Mycobacterium leprae isolated from a seventh‐century Hungarian case of lepromatous leprosy
Authors: Mendum T. A. , Taylor G. M. , Donoghue H. D. , Wu H. , Szalontai C. , Marcsik A. , Molnár E. , Pálfi G. , Stewart G. R.
Published: May 2018

We report on a Mycobacterium leprae genome isolated from the remains of an individual with lepromatous leprosy that were excavated from a seventh‐century Hungarian cemetery. We determined that the genome was from a single nucleotide polymorphism (SNP) type 3K0 M. leprae strain, a lineage that diverged early from other M. leprae lineages. This is one of the earliest 3K0 M. leprae genomes to be sequenced to date. A number of novel SNPs as well as SNPs characteristic of the 3K0 lineage were confirmed by conventional polymerase chain reaction and Sanger sequencing. Recovery of accompanying human DNA from the burial was poor, particularly when compared with that of the pathogen. Modern 3K0 M. leprae strains have only been isolated from East Asia and the Pacific, and so these findings require new scenarios to describe the origins and routes of dissemination of leprosy during antiquity that have resulted in the modern phylogeographical distribution of M. leprae.
Over 4,500 years of trepanation in Poland: From the unknown to therapeutic advisability
Authors: Lorkiewicz W. , Mietlińska J. , Karkus J. , Żądzińska E. , Jakubowski J. K. , Antoszewski B.
Published: May 2018

This paper discusses 6 trepanned skulls from central Poland, dating from the late Neolithic (3,000–2,800 BC) to early modern times (18th century AD). Four of them come from a small area in and around the town of Brześć Kujawski in Kujawy, a region of long‐lasting and intense human settlement in Poland. The analysed skulls provide striking evidence for the long history of trepanation in this part of Europe. Three surgical techniques were used: sawing, scraping, and drilling, either on their own or in combination with one another. Regardless of the method, all the trepanations were fully healed, which proves long‐term survival of the patients. All skulls belonged to adult males, who were generally at a higher risk of trauma in the populations from which 4 of the specimens derive. The studied skulls demonstrate a marked evolution in trepanation practices over time. Trepanations from the late medieval and early modern times tend to be smaller, less life threatening, and clearly made for therapeutic purposes to remedy cranial injuries. The remarkable skills of the surgeons who performed them could be linked to the influence of the renowned Danzig Anatomical School in Gdańsk, which was one of the leading centres of medical and anatomical research in northern and central Europe in the 17th and 18th centuries.
Dentin isotopic reconstruction of individual life histories reveals millet consumption during weaning and childhood at the Late Neolithic (4500 bp) Gaoshan site in southwestern China
Authors: Yi Bing , Liu Xiangyu , Yuan Haibing , Zhou Zhiqing , Chen Jian , Wang Tingting , Wang Yajuan , Hu Yaowu , Fuller Benjamin T.
Published: May 2018

Here, we present results of a pilot project that measured δ13C and δ15N values in bone collagen (ribs and femora) as well as dentin serial sections to examine individual dietary life histories at a Late Neolithic (4500 bp) site known as Gaoshan Ancient City (高山古城) located on the Chengdu Plain in Sichuan Province, China. The isotopic data of the bones indicate that humans consumed C3‐based foods, which corresponds to the dominance of rice agriculture in this region. However, the isotopic data of the dentin serial sections of five individuals display much more positive δ13C values than those of the bones, strongly suggesting that millets (a C4 crop) contributed substantially to human diets during the weaning process and early childhood. Furthermore, the isotopic profiles of dentin sections of the first molars and canines demonstrate that the cession of weaning was individually variable and completed between ~2.5 and 4 years of age. Although limited in scope, this pilot study offers new evidence of millet consumption during human growth and development even though individuals relied on rice exclusively as adults. Moreover, our study provides another perspective with which to rethink the role that millets played during the development and spread of millet agriculture to the south of China in terms of cultural exchange and migration.
Optimal state estimation for equality‐constrained systems with complex noise
Authors: Yu Xingkai , Li Jianxun , Xu Jian , Zhang Zhe
Published: May 2018

Accurate system description is important to obtain accurate state estimation for many application areas. Much a priori information and complex noise pollution exist in real systems and impact the accuracy of system descriptions. Thus, this paper focuses on the state estimation problem with prior information for systems with complex noise pollution. Considering the additional prior information about the state with constraint increase, the estimate quality is compared to classical state estimation methods, which cannot utilize the prior information. Therefore, linear systems with complex noise include additive noise and multiplicative noise, which are taken into account, and an optimal algorithm is deduced. For nonlinear systems and non‐Gaussian complex noise, an algorithm is proposed based on variational Bayesian inference to address this general problem. Furthermore, an algorithm comparison, a performance analysis, and a convergence analysis are presented. The estimation performance is illustrated in numerical target tracking examples.
The impact of obesity on perceived patient‐centred communication
Authors: Phelan S. M. , Lynch B. A. , Blake K. D. , Blanch‐Hartigan D. , Hardeman R. , Wilson P. , Branda M. , Finney Rutten L. J.
Published: May 2018

Objective

Patient–provider communication has been found to be less patient centred, on average, with patients who are members of stigmatized or minority groups. Obesity is a stigmatized condition, and thus, people with obesity may experience less patient‐centred communication (PCC). The objective of this study was to assess the association between patient body mass index (BMI) and self‐reported quality of PCC experienced over a 12‐month period and whether that relationship differed for men and women.

Methods

Data collected for the National Cancer Institute's Health Information National Trends Survey were analysed. Respondents who reported a BMI ≥ 18.5 kg/m2 and indicated having seen a healthcare provider outside of an emergency room in the last 12 months were included. PCC was measured using a validated six‐item scale. Multivariate logistic regression was used to model the odds of reporting PCC greater than the sample median.

Results

Compared with people with normal weight BMIs, no associations were found between overweight (odds ratio [OR] = 0.84, p = 0.17), class I & II obesity (OR = 0.94, p = 0.68) or class III obesity (OR = 0.86, p = 0.47) and PCC. There was a significant interaction (p = 0.015) such that for men, but not women, higher BMI was associated with less PCC.

Conclusion

Unlike evidence that women experience more weight stigma, in the healthcare domain, men may be at elevated risk of experiencing communication influenced by weight stigma.