bluuebunny/crossref_metadata_2025 huggingface dataset:
Epigenetika in samomorilno vedenje
Authors: Uršič Katarina , Videtič Paska Alja
Published: October 2018

Samomor je dobro opisan javnozdravstveni problem. Glede na število samomorov se Slovenija že dolgo uvršča v svetovni vrh. Na biološki ravni so bile opravljene številne genetske in biokemijske raziskave živčnih prenašalcev, v zadnjih letih so pogostejše tudi raziskave na področju epigenetike, kamor uvrščamo delovanje nekodirajočih RNA (miRNA), metilacijo DNA in posttranslacijske modifikacije histonov. Mikro RNA so kratke, 19–25 nukleotidov dolge enoverižne molekule RNA, ki se specifično vežejo na mRNA in znižajo izražanje tarčnih genov. Pri žrtvah samomora so zaznali spremembe v izražanju miRNA v povezavi z možganskim nevrotrofnim dejavnikom (BDNF) in njegovim receptorjem (TrkB), transkripcijskimi in rastnimi dejavniki ter poliaminskim sistemom. Metilacija DNA je proces dodajanja metilne skupine na mesto 5C citozina, posledica pa je znižanje prepisovanja genov. S študijami globalnega vzorca metilacije so pri žrtvah samomora prepoznali spremenjene vzorce metilacije promotorskih regij. Številni promotorji so pripadali genom, vpletenim v kognitivne funkcije. Na ravni posameznih genov so spremembe v vzorcu metilacije promotorske regije opazili pri BDNF in genu za receptor TrkB, ribosomski RNA in serotoninskem receptorju tipa 2A. Histoni so osnovni gradniki jedrnega kromatina; predstavljajo proteinsko osnovo, okoli katere se navije DNA. Tako skupaj tvorijo nukleosom. Histone sestavlja globulni centralni del in N-terminalni rep. Dolžina slednjega je lahko različna in na aminokislinskih ostankih repa so lahko prisotne posttranslacijske modifikacije. Med njimi so najpogostejše acetilacija in metilacija lizinov in argininov, fosforilacija serinov in treoninov, ubikvitinacija in sumoilacija lizinov in ADP-ribozilacija. Pri žrtvah samomora so opazili spremembe modifikacij histonov pri TrkB in poliaminskem sistemu. Številne študije tako povezujejo epigenetske mehanizme s samomorilnim vedenjem.
Economia urbana e regional: território, cidade e desenvolvimento
Authors: de Moura Pires Mônica , Rubiera Morollón Fernando , da Silva Gomes Andréa , Polèse Mario
Published: October 2018

O livro é composto por três partes. A primeira trata dos fundamentos da Economia Urbana e Regional, referindo-se às suas bases conceituais e analíticas e os fundamentos da Economia de Aglomeração. A segunda parte aborda a Economia Urbana, tratando das principais teorias da localização e do impacto da distância e do espaço sobre a atividade econômica. A última parte foca na Economia Regional para compreender a forma e a estrutura das cidades e a localização das atividades econômicas, ampliando o conjunto do território e introduzindo as possíveis políticas econômicas para enfrentar as desigualdades entre territórios.
Engineering induction of singular neural rosette emergence within hPSC-derived tissues
Authors: Knight Gavin T , Lundin Brady F , Iyer Nisha , Ashton Lydia MT , Sethares William A , Willett Rebecca M , Ashton Randolph Scott
Published: October 2018

Human pluripotent stem cell (hPSC)-derived neural organoids display unprecedented emergent properties. Yet in contrast to the singular neuroepithelial tube from which the entire central nervous system (CNS) develops in vivo, current organoid protocols yield tissues with multiple neuroepithelial units, a.k.a. neural rosettes, each acting as independent morphogenesis centers and thereby confounding coordinated, reproducible tissue development. Here, we discover that controlling initial tissue morphology can effectively (>80%) induce single neural rosette emergence within hPSC-derived forebrain and spinal tissues. Notably, the optimal tissue morphology for observing singular rosette emergence was distinct for forebrain versus spinal tissues due to previously unknown differences in ROCK-mediated cell contractility. Following release of geometric confinement, the tissues displayed radial outgrowth with maintenance of a singular neuroepithelium and peripheral neuronal differentiation. Thus, we have identified neural tissue morphology as a critical biophysical parameter for controlling in vitro neural tissue morphogenesis furthering advancement towards biomanufacture of CNS tissues with biomimetic anatomy and physiology.
An NAD+-dependent novel transcription factor controls stage conversion in Entamoeba
Authors: Manna Dipak , Lentz Christian Stephan , Ehrenkaufer Gretchen Marie , Suresh Susmitha , Bhat Amrita , Singh Upinder
Published: October 2018

Developmental switching between life-cycle stages is a common feature among parasitic pathogens to facilitate disease transmission and pathogenesis. The protozoan parasite Entamoeba switches between invasive trophozoites and dormant cysts, but the encystation process remains poorly understood despite being central to amoebic biology. We identify a transcription factor, Encystation Regulatory Motif-Binding Protein (ERM-BP), that regulates encystation. Down-regulation of ERM-BP decreases encystation efficiency resulting in abnormal cysts with defective cyst walls. We demonstrate that direct binding of NAD+ to ERM-BP affects ERM-BP conformation and facilitates its binding to promoter DNA. Additionally, cellular NAD+ levels increase during encystation and exogenous NAD+ enhances encystation consistent with the role of carbon source depletion in triggering Entamoeba encystation. Furthermore, ERM-BP catalyzes conversion of nicotinamide to nicotinic acid, which might have second messenger effects on stage conversion. Our findings link the metabolic cofactors nicotinamide and NAD+ to transcriptional regulation via ERM-BP and provide the first mechanistic insights into Entamoeba encystation.
Deletion of KCNQ2/3 potassium channels from PV+ interneurons leads to homeostatic potentiation of excitatory transmission
Authors: Soh Heun , Park Suhyeorn , Ryan Kali , Springer Kristen , Maheshwari Atul , Tzingounis Anastasios V
Published: October 2018

KCNQ2/3 channels, ubiquitously expressed neuronal potassium channels, have emerged as indispensable regulators of brain network activity. Despite their critical role in brain homeostasis, the mechanisms by which KCNQ2/3 dysfunction lead to hypersychrony are not fully known. Here, we show that deletion of KCNQ2/3 channels changed PV+ interneurons’, but not SST+ interneurons’, firing properties. We also find that deletion of either KCNQ2/3 or KCNQ2 channels from PV+ interneurons led to elevated homeostatic potentiation of fast excitatory transmission in pyramidal neurons. Pvalb-Kcnq2 null-mice showed increased seizure susceptibility, suggesting that decreases in interneuron KCNQ2/3 activity remodels excitatory networks, providing a new function for these channels.
Aberrant information transfer interferes with functional axon regeneration
Authors: Ding Chen , Hammarlund Marc
Published: October 2018

Functional axon regeneration requires regenerating neurons to restore appropriate synaptic connectivity and circuit function. To model this process, we developed an assay in Caenorhabditis elegans that links axon and synapse regeneration of a single neuron to recovery of behavior. After axon injury and regeneration of the DA9 neuron, synapses reform at their pre-injury location. However, these regenerated synapses often lack key molecular components. Further, synaptic vesicles accumulate in the dendrite in response to axon injury. Dendritic vesicle release results in information misrouting that suppresses behavioral recovery. Dendritic synapse formation depends on dynein and jnk-1. But even when information transfer is corrected, axonal synapses fail to adequately transmit information. Our study reveals unexpected plasticity during functional regeneration. Regeneration of the axon is not sufficient for the reformation of correct neuronal circuits after injury. Rather, synapse reformation and function are also key variables, and manipulation of circuit reformation improves behavioral recovery.
Confidence in eating disorder knowledge does not predict actual knowledge in collegiate female athletes
Authors: Rosa-Caldwell Megan E. , Todden Christopher , Caldwell Aaron R. , Breithaupt Lauren E.
Published: October 2018

Background

Eating disorders are serious psychological disorders with long term health impacts. Athletic populations, tend to have higher incidences of eating disorders compared to the general population. Yet there is little known about athletes’ eating disorder knowledge and how it relates to their confidence in their knowledge. Therefore, the purpose of our study was to evaluate collegiate female athletes’ eating disorder (ED) knowledge and confidence in their knowledge. 51 participants were recruited from a National Association of Intercollegiate Athletics (NAIA) university in the mid-west and asked to complete a 30-question exam assessing one’s knowledge of five different categories related to eating disorders. Confidence in the correctness of answers was assessed with a 5-point Likert-scale (1 = very unconfident, 5 = very confident). A one-way ANOVA was used to determine differences between scores on different categories and overall scores. A simple regression analysis was used to determine if confidence or age was predictive in knowledge scores.

Results

The average score of participants was 69.1%, SD = 10.8% with an average confidence of 3.69/5, SD = 0.33. Athletes scored lowest with regards to Identifying Signs and Symptoms of EDs compared to other sub-scores (p < 0.05). There was no relationship between knowledge and confidence scores.

Discussion

There is limited ED knowledge among collegiate female athletes. This may be problematic as many athletes appear confident in the correctness of their answers despite these low scores. Coaches should be aware of this lack of knowledge and work with clinical practitioners, such as dieticians, team physicians and athletic trainers to educate and monitor their athletes on eating disorders, specifically signs and symptoms.
Effects of sleep deprivation on executive functioning, cognitive abilities, metacognitive confidence, and decision making
Authors: Aidman Eugene , Jackson Simon A. , Kleitman Sabina
Published: October 2018

Performance on many decision‐making tasks is underpinned by metacognitive monitoring, cognitive abilities, and executive functioning. Fatigue‐inducing conditions, such as sleep loss, compromise these factors, leading to decline in decision performance. Using a 40‐hr sleep deprivation protocol, we examined these factors and the resulting decision performance. Thirteen Australian Army male volunteers (aged 20–30 years) were tested at multiple time points on psychomotor vigilance, inhibitory control, task switching, working memory, short‐term memory, fluid intelligence, and decision accuracy and confidence in a medical diagnosis‐making test. Assessment took place in the morning and night over two consecutive days, during which participants were kept awake. Consistent with previous work, cognitive performance declined after a night without sleep. Extending previous findings, self‐regulation and self‐monitoring suffered significantly greater declines immediately after the sleepless night. These results indicate that the known decline in complex decision‐making performance under fatigue‐inducing conditions might be facilitated by metacognitive rather than cognitive mechanisms.
Dual Functions of Crystallization Control and Defect Passivation Enabled by Sulfonic Zwitterions for Stable and Efficient Perovskite Solar Cells
Authors: Zheng Xiaopeng , Deng Yehao , Chen Bo , Wei Haotong , Xiao Xun , Fang Yanjun , Lin Yuze , Yu Zhenhua , Liu Ye , Wang Qi , Huang Jinsong
Published: October 2018

Uniform and high‐electronic‐quality perovskite thin films are essential for high‐performance perovskite devices. Here, it is shown that the 3‐(decyldimethylammonio)‐propane‐sulfonate inner salt (DPSI), which is a sulfonic zwitterion, plays dual roles in tuning the crystallization behavior and passivating the defects of perovskites. The synergistic effect of crystallization control and defect passivation remarkably suppresses pinhole formation, reduces the charge trap density, and lengthens the carrier recombination lifetime, and thereafter boosts the small‐area (0.08 cm2) planar perovskite device efficiency to 21.1% and enables a high efficiency of 18.3% for blade‐coating large‐area (1 cm2) devices. The device also shows good light stability, which remains at 88% of the initial efficiency under continuous unfiltered AM 1.5G light illumination for 480 h. These findings provide an avenue for simultaneous crystallization control and defect passivation to further improve the performance of perovskite devices.
Atomically Thin 2D Transition Metal Oxides: Structural Reconstruction, Interaction with Substrates, and Potential Applications
Authors: Yang Tong , Song Ting Ting , Callsen Martin , Zhou Jun , Chai Jian Wei , Feng Yuan Ping , Wang Shi Jie , Yang Ming
Published: October 2018

The discovery of graphene has stimulated dramatic research interest on other 2D materials including transition metal oxide (TMO) monolayers in order to realize novel functionalization and applications. Due to reduced bonding coordination and strong surface polarization, the structures of most TMOs in the monolayer limit are very different from their bulk counterparts, as well as their physical and chemical properties. In this brief review, the authors summarize recent research progress on atomically thin TMO layers. The focus is on the structural properties of the TMOs and their interaction with the substrates from the computational point of view. The authors also introduce the potential applications of the TMO 2D materials on supercapacitors, photocatalysts, batteries, and sensors.
A New Graphitic Carbon Nitride/Horseradish Peroxidase Hybrid Nano–Bio Artificial Catalytic System for Unselective Degradation of Persistent Phenolic Pollutants
Authors: Li Chunmei , Yu Siyu , Gu Lei , Han Juan , Dong Hongjun , Wang Yun , Chen Gang
Published: October 2018

It has always been a challenge to fabricate artificial catalytic system as one promising strategy of using solar energy for chemical synthesis, fuel production, electrochemical detection, pollutant degradation, etc. Here a new g‐C3N4/horseradish peroxidase hybrid nano–bio artificial catalytic system is exploited. The coupling effect between photocatalysis and biocatalysis cycles not only forcefully improves the separation efficiency of charge carriers but also continuously produces more OH active species, finally realizing high‐efficiency and unselective degradation of various persistent phenolic pollutants, such as bisphenol A, phenol, p‐nitrophenol, and 2‐naphthol. This work provides an innovative design idea to fabricate general artificial catalytic system that may be widely used in treatment of organic pollutants.
Surface Modifying Doped Silicon Nanowire Based Solar Cells for Applications in Biosensing
Authors: Smith Rasheid , Duan Wenqi , Quarterman Juliana , Morris Angie , Collie Ceryce , Black Marcie , Toor Fatima , Salem Aliasger K.
Published: October 2018

There is a growing demand for biosensors that are reliable, accurate, rapid, and cost effective. Appropriately functionalized silicon nanowires (SiNWs) have offered an alternative to the gold standards of enzyme linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR)‐based detection of proteins and DNA, respectively, by offering rapid label‐free accurate detection of analytes. However, a major barrier limiting the progression of this technology is the cost of fabricating uniform functional nanowires (NWs) for biosensing and electrically contacting these NWs. Preliminary results are presented demonstrating the feasibility of a novel class of SiNW‐based biosensor, which alleviates these issues. The SiNW‐based biosensor presented here uses a SiNW‐based solar cell (SiNW‐SC) as a transducing element. It is demonstrated that SiNW‐SCs can be modified by anchoring monoclonal antibodies specific for prostate‐specific antigen (PSA) to the surface of SiNW‐SCs. This surface modification allows for an increase in binding of PSA to the SiNW structures, which causes an increase in short‐circuit density of SiNW‐SCs when exposed to light and PSA. This paves the way for the development of a novel class of SiNW‐based biosensors using surface modification of SiNW‐SCs.
Functionalized Cellulose‐Co(II)‐Bis‐Terpyridine Hybrid Material as Colorimetric Sensor for Micromolar Aqueous Cyanide
Authors: Collins Cameron C. , Regalado‐Love Sean , Portillo Romeo I. , Boston David J. , Shores Matthew P. , Bhowmick Indrani
Published: October 2018

A novel surface modification approach is taken to cyanide‐sensing by using functionalized cellulose surface that is chemically modified by immobilizing cobalt(II)‐bis‐terpyridine complex on it. The cobalt(II)‐bis‐tpy complex can exhibit selective “naked eye” colorimetric detection of micromolar level cyanide in aqueous solution, where the visible red‐orange color of cobalt(II)‐bis‐tpy complex solution (aqueous) disappears in the presence of cyanide ions. In order to make the sensor more proficient and easy to use, these cobalt(II)‐bis‐tpy molecules are chemically grafted on the surface of microcrystalline cellulose and cellulose paper, which turns the color of functionalized cellulose orange‐red. Both of these colored cellulose powder and paper exhibit color loss in 10−6m aqueous solution of potassium cyanide. This functionalized hybrid inorganic–organic paper offers an easy “dip and detect” cyanide sensing.
A randomized trial of three novel regimens for recurrent acute myeloid leukemia demonstrates the continuing challenge of treating this difficult disease
Authors: Litzow Mark R. , Wang Xin V. , Carroll Martin P. , Karp Judith E. , Ketterling Rhett P. , Zhang Yanming , Kaufmann Scott H. , Lazarus Hillard M. , Luger Selina M. , Paietta Elisabeth M. , Pratz Keith W. , Tun Han Win , Altman Jessica K. , Broun Edward R. , Rybka Witold B. , Rowe Jacob M. , Tallman Martin S.
Published: October 2018

To improve the outcome of relapsed/refractory acute myeloid leukemia (AML), a randomized phase II trial of three novel regimens was conducted. Ninety patients were enrolled and were in first relapse or were refractory to induction/re‐induction chemotherapy. They were randomized to the following regimens: carboplatin‐topotecan (CT), each by continuous infusion for 5 days; alvocidib (formerly flavopiridol), cytarabine, and mitoxantrone (FLAM) in a timed sequential regimen; or sirolimus combined with mitoxantrone, etoposide, and cytarabine (S‐MEC). The primary objective was attainment of a complete remission (CR). A Simon two‐stage design was used for each of the three arms. The median age of the patients in the FLAM arm was older at 62 years compared with 55 years for the CT arm and the S‐MEC arm. The overall response was 14% in the CT arm (5/35, 90% CI 7%‐35%), 28% in the FLAM arm (10/36, 90% CI, 16%‐43%), and 16% in the S‐MEC arm (3/19, 90% CI, 4%‐36%). There were nine treatment‐related deaths, seven of which occurred in the FLAM arm with four of these in elderly patients. We conclude that the FLAM regimen had an encouraging response rate and should be considered for further clinical development but should be used with caution in elderly patients.
One, Two, Three: A Bioorthogonal Triple Labelling Strategy for Studying the Dynamics of Plant Cell Wall Formation In Vivo
Authors: Simon Clemence , Lion Cedric , Spriet Corentin , Baldacci‐Cresp Fabien , Hawkins Simon , Biot Christophe
Published: October 2018

Reported herein is an in vivo triple labelling strategy to monitor the formation of plant cell walls. Based on a combination of copper‐catalysed alkyne–azide cycloaddition (CuAAC), strain‐promoted azide–alkyne cycloaddition (SPAAC), and Diels–Alder reaction with inverse electronic demand (DARinv), this methodology can be applied to various plant species of interest in research. It allowed detection of the differential incorporation of alkynyl‐, azido‐, and methylcyclopropenyl‐tagged reporters of the three main monolignols into de novo biosynthesized lignin in different tissues, cell types, or cell wall layers. In addition, this triple labelling was implemented with different classes of chemical reporters, using two monolignol reporters in conjunction with alkynylfucose to simultaneously monitor the biosynthesis of lignin and non‐cellulosic polysaccharides. This allowed observation of their deposition occurring contemporaneously in the same cell wall.
Schaltbare Katalyse zur Herstellung von Multiblock‐Polyestern aus einer Mischung von Propylenoxid, Lactid und Phthalsäureanhydrid
Authors: Stößer Tim , Mulryan Daniel , Williams Charlotte K.
Published: October 2018

Schaltbare Polymerisationskatalyse ermöglicht die Synthese von Multiblock‐Polyestern mit hohen Selektivitäten bezüglich Blockpolymeren aus Mischungen von Monomeren. Der Al‐Salphen‐Katalysator “schaltet” zwischen zwei unterschiedlichen Polymerisationsmechanismen und polymerisiert hoch selektiv Mischungen der kommerziell verfügbarer Monomere Lactid, Phthalsäureanhydrid und Propylenoxid. Aufeinanderfolgende Zugaben von Monomermischungen erlauben die Synthese von Multiblock‐Polyestern mit 3, 7, 11, 15, 19 und 23 Blöcken. Diese einmalige Selektivität der Katalyse erlaubt die Verwendung von vollkommen neuen Multiblock‐Polyestern für zukünftige Anwendungen.
Nebulization Prior to Isolation, Ionization, and Dissociation of the Neutral Serine Octamer Allows Its Characterization
Authors: Zhang Hong , Wei Zhenwei , Jiang Jie , Cooks R. Graham
Published: October 2018

Nebulization of enantiomerically mixed serine solutions, followed by ion deflection and gentle on‐line protonation, is used to isolate and characterize the strongly preferred homochiral neutral serine octamer (Ser8). The separation of the nebulization and ionization steps and the use of the enantiomeric l‐serine ion (l‐d3Ser)8H+ as a soft protonating agent ensured that neutral (d‐Ser)8 was characterized without interference from serine octamer ((d‐Ser)8H+) ions. MS/MS experiments showed that the ionized neutral octamer and the protonated octamer formed directly by ESI have the same structures. Experiments in which the temperature of the heated transfer tube was varied indicate dissociation of the neutral octamer to the dimer. Field‐free nebulization of racemic serine forms the separate homochiral species with very high chiral selectivity. We suggest that the homochiral preference is a property of (d‐Ser)8 and that the preference observed earlier for (d‐Ser)8H+ is simply an expression of this feature of the neutral cluster.
Inversion Triggered by Protonation—A Rubyrin with Embedded α,β′‐Pyridine Moieties
Authors: Myśliborski Radomir , Hurej Karolina , Pawlicki Miłosz , Latos‐Grażyński Lechosław
Published: October 2018

Incorporation of α,β′‐pyridine into a [26]hexaphyrin(1.1.0.1.1.0) frame resulted in formation of 29,33‐diaza‐A,D‐di‐p‐benzi[26]hexaphyrin (A,D‐di‐p‐pyrirubyrin), which acquires a strictly planar conformation with two nitrogen pyridine atoms directed to the center of the macrocyclic core. The mode of α,β′‐pyridine incorporation results in efficient 26‐electron π‐conjugation, as shown by the clear spectroscopic and structural aromatic features. The formation of the trication and tetracation through protonation is accompanied by a conformational flip of one or two pyridinium moieties to result in N‐confused or doubly N‐confused conformers of the original macrocyclic frame.
Synthesis and Properties of a Highly Congested Tri(9‐anthryl)methyl Radical
Authors: Nishiuchi Tomohiko , Aibara Seito , Kubo Takashi
Published: October 2018

The synthesis of persistent, neutral organic radicals is challenging because of their inherent reactivities. Herein, we report the synthesis and characterization of a highly congested mesityl‐substituted tri(9‐anthryl)methyl (TAntM) radical (1). The scaffold was successfully synthesized by circumventing the steric hindrance imposed by the bulky groups surrounding the central methyl carbon atom. The radical has a threefold propeller structure, and the unpaired electron is mainly localized on the central carbon atom. Owing to its congested structure, 1 is remarkably stable, which facilitated handling under ambient conditions. Evaluation of the dynamic behavior of the TAntM scaffold indicated that the stability is due to the bulky anthryl units and the mesityl substituents. Because of its high persistence, wide‐range absorption, and good reversible redox properties, 1 has promising applications in organic devices.
Simultaneous Manipulation of O‐Doping and Metal Vacancy in Atomically Thin Zn10In16S34 Nanosheet Arrays toward Improved Photoelectrochemical Performance
Authors: Meng Linxing , Rao Dewei , Tian Wei , Cao Fengren , Yan Xiaohong , Li Liang
Published: October 2018

The facile hydrothermal synthesis of Zn10In16S34 atomically thin nanosheet arrays on fluorine‐doped tin oxide glass (FTO) substrates is presented. Through controlling heat treatment in air, O‐doping and Zn, S vacancies were simultaneously introduced in Zn10In16S34 nanosheets with adjusted phase, morphology, chemical compositions, and energy level distribution. The surface defect states are passivated by depositing ultrathin Al2O3 film by atomic layer deposition technology. The performance of Zn10In16S34 photoanodes is largely improved, with 4.7 times higher current density and reduced onset potential. The experimental results and density functional theory calculations indicate that the enhancement is attributed to the fast photoexcited electron–hole pair separation, decreased surface transfer impedance, prolonged carrier lifetime, and reduced overpotential of oxygen evolution reaction.
Switch Catalysis To Deliver Multi‐Block Polyesters from Mixtures of Propene Oxide, Lactide, and Phthalic Anhydride
Authors: Stößer Tim , Mulryan Daniel , Williams Charlotte K.
Published: October 2018

Switchable polymerisation catalysis enables block polymer sequence selectivity from monomer mixtures, resulting in the formation of multiblock polyesters. The aluminium salphen catalyst switches between two different polymerisation mechanisms and selectively enchains mixtures of commercially available monomers: lactide, phthalic anhydride, and propene oxide. Sequential monomer mixture additions yield multi‐block polyesters featuring 3, 7, 11, 15, 19, 23, and 27 blocks. The unparalleled catalytic selectivity can be used to access completely new multi‐block polyesters relevant for future applications.
Photochromism and decolorization controlled by auxiliary ligands of complexes derived from 1‐methyl‐4,4′‐bipyridinium cation
Authors: Liu Jin‐jian
Published: October 2018

Three 1‐methyl‐4,4′‐bipyridinium (MQ+)‐based complexes, {[Cd(MQ)(p‐BDC)Br]⋅H2O}n (1), {[Cd(MQ)(m‐BDC)(H2O)Br]⋅3H2O}n (2) and Cu(MQ)Br2 (3) (p‐H2BDC = 1,4‐benzenedicarboxylic acid, m‐H2BDC = 1,3‐benzenedicarboxylic acid), have been synthesized and structurally characterized. Compounds 1 and 2 are one‐dimensional coordination polymers constituted of one coordinated MQ+ cation, one coordinated Br− ion and chains of Cd2+ ions connected by deprotonated BDC2− units, which both have photochromism but different decolorization behaviors. The structures and photoresponsive behaviors controlled by auxiliary ligands have been explored. Compound 3 is constituted of one Cu+ center, one MQ+ ligand and two coordinated Br− ions in a ‘V’ configuration, exhibiting no photochromism.
Is the DOSPERT gender invariant? A psychometric test of measurement invariance
Authors: Zhang Don C. , Foster Garett C. , McKenna Michael G.
Published: October 2018

It is well established in the risk literature that men tend to take more risks than women. This gender difference, however, is often qualified by its domain specificity. Considering recent research on the domain generality of risk taking as a disposition, there is a need to examine the degree to which men take more risks than women, in general. In order to make substantive conclusions about the gender differences in risk‐taking propensity, one must first establish measurement invariance, which is required for the meaningful interpretation of observed group differences. In this paper, we examined the measurement invariance of the Domain‐Specific Risk‐Taking scale (DOSPERT)—one of the most popular measures of individual differences in risk taking. We found that the DOSPERT violated configural invariance in a bifactor model, indicating that the underlying factor structure of the DOSPERT differs between men and women. Even after removing the social risk dimension, DOSPERT still failed to reach scalar invariance. Taken together, these findings suggest that score differences in the DOSPERT may be due to response artifacts rather than true differences in the latent construct. Therefore, gender differences in the DOSPERT must be interpreted with caution. Implications for the measurement of risk taking are discussed.
Evolution of Antigenic Variation in African Trypanosomes: Variant Surface Glycoprotein Expression, Structure, and Function
Authors: Bangs James D.
Published: October 2018

The process of antigenic variation in parasitic African trypanosomes is a remarkable mechanism for outwitting the immune system of the mammalian host, but it requires a delicate balancing act for the monoallelic expression, folding and transport of a single variant surface glycoprotein (VSG). Only one of hundreds of VSG genes is expressed at time, and this from just one of ≈15 dedicated expression sites. By switching expression of VSGs the parasite presents a continuously shifting antigenic facade leading to prolonged chronic infections lasting months to years. The basics of VSG structure and switching have been known for several decades, but recent studies have brought higher resolution to many aspects this process. New VSG structures, in silico modeling of infections, studies of VSG codon usage, and experimental ablation of VSG expression provide insights that inform how this remarkable system may have evolved.
A population‐averaged approach to diagnostic test meta‐analysis
Authors: Preisser John S. , Inan Gul , Powers James M. , Chu Haitao
Published: October 2018

The meta‐analysis of diagnostic accuracy studies is often of interest in screening programs for many diseases. The typical summary statistics for studies chosen for a diagnostic accuracy meta‐analysis are often two dimensional: sensitivities and specificities. The common statistical analysis approach for the meta‐analysis of diagnostic studies is based on the bivariate generalized linear‐mixed model (BGLMM), which has study‐specific interpretations. In this article, we present a population‐averaged (PA) model using generalized estimating equations (GEE) for making inference on mean specificity and sensitivity of a diagnostic test in the population represented by the meta‐analytic studies. We also derive the marginalized counterparts of the regression parameters from the BGLMM. We illustrate the proposed PA approach through two dataset examples and compare performance of estimators of the marginal regression parameters from the PA model with those of the marginalized regression parameters from the BGLMM through Monte Carlo simulation studies. Overall, both marginalized BGLMM and GEE with sandwich standard errors maintained nominal 95% confidence interval coverage levels for mean specificity and mean sensitivity in meta‐analysis of 25 of more studies even under misspecification of the covariance structure of the bivariate positive test counts for diseased and nondiseased subjects.
Multivariate learning framework for long‐term adaptation in the artificial pancreas
Authors: Shi Dawei , Dassau Eyal , Doyle Francis J.
Published: October 2018

The long‐term use of the artificial pancreas (AP) requires an automated insulin delivery algorithm that can learn and adapt with the growth, development, and lifestyle changes of patients. In this work, we introduce a data‐driven AP adaptation method for improved glucose management in a home environment. A two‐phase Bayesian optimization assisted parameter learning algorithm is proposed to adapt basal and carbohydrate‐ratio profile, and key feedback control parameters. The method is evaluated on the basis of the 111‐adult cohort of the FDA‐accepted UVA/Padova type 1 diabetes mellitus simulator through three scenarios with lifestyle disturbances and incorrect initial parameters. For all the scenarios, the proposed method is able to robustly adapt AP parameters for improved glycemic regulation performance in terms of percent time in the euglycemic range [70, 180] mg/dl without causing risk of hypoglycemia in terms of percent time below 70 mg/dl.
Effect of Costus spiralis (Jacq.) Roscoe Leaves, Methanolic Extract and Guaijaverin on Blood Glucose and Lipid Levels in a Type II Diabetic Rat Model
Authors: Duarte Regiane C. , Taleb‐Contini Silvia H. , Pereira Paulo S. , Oliveira Camila F. , Miranda Carlos Eduardo S. , Bertoni Bianca W. , Coppede Juliana S. , Willrich Guilherme B. , Crevelin Eduardo J. , França Suzelei C. , Pereira Ana Maria S.
Published: October 2018

This study aimed to isolate and identify flavonoids with hypoglycemic activity in Costus spiralis leaves. The methanolic extract (ME) was rich in flavonoids, while the powdered leaves (PL) contained considerable amounts of macro‐ and microelements. Oral acute treatment of streptozotocin (STZ)‐induced diabetic rats for 18 h with the C. spiralis PL, ME and isolated guaijaverin (GUA) lowered glycemia, improved oral glucose tolerance and inhibited liver lipid peroxidation. GUA and ME lowered plasma levels of low‐density and non‐high density lipoproteins; GUA also lowered total cholesterol levels. PL, ME and GUA did not significantly alter the plasma levels of triglycerides, high‐density lipoproteins, very low‐density lipoproteins, creatinine and aspartate transaminase, and the total protein levels in the kidney and liver tissues. Therefore, C. spiralis leaves are promising raw materials and rich sources of bioactive flavonoids for the development of novel antidiabetic drugs due to their hypoglycemic, antidyslipidemic and antioxidant actions.
Exosomes: Isolation, Analysis, and Applications in Cancer Detection and Therapy
Authors: Bu Hongchang , He Dinggeng , He Xiaoxiao , Wang Kemin
Published: October 2018

Exosomes are cell‐derived small extracellular vesicles that are naturally secreted by all types of cells and widely distributed in various biofluids. They carry a variety of key bioactive molecules (e.g., nucleic acids, proteins, growth factors, cytokines) from their parent cells and convey them to neighboring or even distant cells through circulation. In recent years, tumor‐derived exosomes have attracted great interest from investigators because they actively participate in nearly all aspects of tumor development and facilitate both tumor growth and metastasis through exosome‐mediated intercellular communication. The vesicular contents are increasingly considered potential biomarkers for tumor diagnoses and prognosis. With the progress made in isolation and analytical technologies, the functions of exosomes and their contents in tumor development are also becoming clearer. In this review article we describe the recent developments in exosome isolation techniques and analysis of exosomal contents. We also address their applications in cancer detection and therapy.
Recent Updates on Protein N‐Phosphoramidate Hydrolases
Authors: Jung Hoyoung , Shin Son Hye , Kee Jung‐Min
Published: October 2018

In contrast to well‐recognized protein phosphorylation on the side‐chain oxygen of Ser, Thr, or Tyr residues, analogous phosphoramidation of the nitrogen of His, Lys, and Arg side chains remains much less investigated, mainly due to the instability of post‐translational modifications and technical difficulties involved in their analysis. For example, reports on the enzyme activities responsible for the formation and hydrolysis of these phosphoramidates date back to as early as the 1950s, but some of these enzymes have only recently been identified and functionally characterized; this has been aided by the development of novel research tools. In this review, we summarize current knowledge of the enzymes that hydrolyze protein N‐phosphoramidates, in terms of their structure, activities, and biological functions, as well as the chemical tools used to investigate them.
Commercial Porcine Gastric Mucin Preparations, also Used as Artificial Saliva, are a Rich Source for the Lectin TFF2: In Vitro Binding Studies
Authors: Stürmer René , Harder Sönke , Schlüter Hartmut , Hoffmann Werner
Published: October 2018

Mucous gels (mucus) cover internal body surfaces. The secretory mucins MUC5AC and MUC6 and the protective peptide TFF2 are characteristic constituents of gastric mucus; TFF2 is co‐secreted with MUC6. Herein, we investigated two commercial mucin preparations by FPLC and proteomics, because they are model systems for studying the rheology of gastric mucins. One preparation is also used as a saliva substitute, for example, after radiation therapy. We show that both preparations contain TFF2 (≈0.6 to 1.1 %, w/w). The majority of TFF2 is strongly bound noncovalently to mucin in a manner that is resistant to boiling in SDS. First overlay assays with 125I‐labeled porcine TFF2 revealed that mucin binding is modulated by Ca2+ and can be blocked by the lectin GSA‐II and the antibody HIK1083, both recognizing the peripheral GlcNAcα1→4Galβ1→R moiety of MUC6. TFF2 binding was also inhibited in the presence of Me‐β‐Gal but less so by the α anomer. TFF2 may play a role in the oligomerization and secretion of MUC6, the rheology of gastric mucus, and the adherence of gastric microbiota. TFF2 in artificial saliva may be of benefit. TFF2 might also interact with the sugar moiety of various receptors.
A Metal‐Free N and P‐Codoped Carbon Nanosphere as Bifunctional Electrocatalyst for Rechargeable Zinc‐Air Batteries
Authors: Li Ping , Jang Haeseong , Zhang Jian , Tian Mochong , Chen Silong , Yuan Bing , Wu Zexing , Liu Xien , Cho Jaephil
Published: October 2018

Developing metal‐free electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are crucial for the large‐scale application of fuel cells and metal‐air batteries, which have attracted extensive attention. Herein, a facile and scalable route is developed to prepare N, P‐codoped carbon nanospheres (NPCs) with the assistance of cesium chloride (NPC‐“Cs”). After treatment with hot acid solution, no trace metals are left in the electrocatalyst, as determined by inductively coupled plasma atom emission spectrometry (ICP‐AES). The obtained metal‐free electrocatalyst exhibits outstanding bifunctional catalytic activity for ORR and OER. The half‐wave potential is 0.85 V for ORR in 0.1 M KOH, and an overpotential of 0.34 V for OER in 1 M KOH is required to reach a current density of 10 mA cm−2. Furthermore, zinc‐air primary and rechargeable batteries assembled with the metal‐free electrocatalyst show similar, or even better performance compared to precious metal‐based devices containing Pt/C or IrO2 as catalysts. A facile strategy is developed to synthesize the metal free bifunctional electrocatalyst for ORR and OER that is beneficial for the development of new‐energy technologies.
A Switch in the Hydrophobic/Hydrophilic Gas‐Adsorption Character of Prussian Blue Analogues: An Affinity Control for Smart Gas Sorption
Authors: Boudjema Lotfi , Long Jérôme , Salles Fabrice , Larionova Joulia , Guari Yannick , Trens Philippe
Published: October 2018

Porous coordination polymers are molecule‐based materials presenting a high degree of tunability, which offer many advantages for targeted applications over conventional inorganic materials. This work demonstrates that the hydrophilic/hydrophobic character of Prussian blue analogues having a lipophilic feature may be tuned to optimize the gas adsorption properties. The role of the coordinatively unsaturated metal sites is emphasized through a combination of theoretical and experimental study of water, ethanol, and n‐hexane adsorption.
AuBr3‐Catalyzed Chemoselective Annulation of Isocyanates with 2H‐Azirine
Authors: Wu Yufeng , Tian Bing , Witzel Sina , Jin Hongming , Tian Xianhai , Rudolph Matthias , Rominger Frank , Hashmi A. Stephen K.
Published: October 2018

The chemoselective cyclization of isocyanates with 2H‐azirine was achieved with AuBr3 as catalyst. This transfer sets the stage for the synthesis of aromatic oxazole‐ureas in a tandem process. The addition of a catalytic amount of phosphite enhances the process enormously. The reaction can also be performed in a one‐pot process using benzoyl azide instead of isocyanate under the same conditions. A detailed study on the role of the phosphite that was applied as an additive revealed that only non‐coordinated phosphite can reduce gold(III) and that gold(I) coordinated phosphite is not oxidized. Accompanied by the reduction of gold, HBr is generated in situ, which turned out to be the actual promotor in combination with the remaining AuBr3. The positive effect of acid can be explained by a strong N–Au coordination, which tends to break more easily in the presence of small amount of protic acid in the reaction solution.
Synthesis and Reactivity Studies of Amido‐Substituted Germanium(I)/Tin(I) Dimers and Clusters
Authors: Kelly John A. , Juckel Martin , Hadlington Terrance J. , Fernández Israel , Frenking Gernot , Jones Cameron
Published: October 2018

Three amide ligands of varying steric bulk and electronic properties were utilized to prepare a series of amido‐germanium(II)/tin(II) halide compounds, (LEX)n, (L= ‐N{B(DipNCH)2}(SiMe3), TBoL; ‐N{B(DipNCH)2}(SiPh3), PhBoL; ‐N(Dip)(tBu), DBuL; Dip=C6H3iPr2‐2,6; E=Ge or Sn; X=Cl or Br; n=1 or 2). Reductions of these with a magnesium(I) dimer, {(MesNacnac)Mg}2 (MesNacnac=[(MesNCMe)2CH]−, Mes=mesityl), afforded singly bonded amido‐digermynes (TBoLGe−GeTBoL and PhBoLGe−GePhBoL), and an amido‐distannyne (PhBoLSn−SnPhBoL), in addition to several low‐valent, amido stabilized tetrel–tetrel bonded cluster compounds, (DBuLGe)4, (DBuLSn)6 and Sn5(TBoL)4. The nature of the products resulting from these reactions was largely dependent on the steric bulk of the amide ligand employed. Cluster (DBuLGe)4 possessed an unusual folded butterfly structure, the bonding and electronic of which were examined using DFT calculations. Reactions of the amido‐germanium(I) compounds with H2 were explored, and gave rise to the amido‐digermene, TBoL(H)Ge=Ge(H)TBoL and the cyclotetragermane, {DBuL(H)Ge}4. Reactions of (DBuLGe)4 with a series of unsaturated small molecule substrates yielded DBuLGeOGeDBuL, DBuLGe(μ‐C2H4)2GeDBuL and DBuLGe(μ‐1,4‐C6H8)(μ‐1,2‐C6H8)GeDBuL. The latter results imply that (DBuLGe)4 can act as a masked source of the digermyne DBuLGeGeDBuL in these reactions. All further reactivity studies indicated that the germanium(I) compounds exhibit a “transition‐metal‐like” behavior, which is closely related to that previously described for bulky digermynes and related compounds.
ACHEMA 2018: Adsorption
Authors: Ambrosy Jonas Moritz , Berg Frederik , Birkmann Jan , Bucher Dirk , Muthmann Johanna , Schmittmann Sonja , Bläker Christian
Published: October 2018

Auf der ACHEMA 2018 stellten sich 24 Firmen mit Bezug zum Themenfeld Adsorption vor. Das weit gefächerte Ausstellerfeld reichte von Adsorbentienherstellern über Messgeräteentwickler bis hin zu Anlagenbauern. Aufgrund der zeitlichen Nähe zur Fachmesse IFAT/Entsorga waren in diesem Jahr etwas weniger Aussteller vertreten als in den vorausgehenden Jahren. Der Bericht umreißt die wichtigsten Trends und Neuerungen aus der Adsorptionstechnik, die auf den Ständen präsentiert und in Gesprächen von den Ausstellern thematisiert wurden.
Niobium Doping in BiVO4: Interplay Between Effective Mass, Stability, and Pressure
Authors: Sarker Hori Pada , Rao Pratap M. , Huda Muhammad N.
Published: October 2018

We have applied density functional theory to study the electronic structure changes caused by Nb incorporation in BiVO4 and the application of external pressure. The overall solubility of Nb in BiVO4 is usually high, and the presence of oxygen vacancies affect the dopability of Nb in BiVO4. Through the analyses of the chemical‐potential landscape, we have determined the single‐phase stability zone of BiVO4 with the Nb doping. The most favorable Nb doping is simultaneous substitutions at both V‐ and Bi‐sites. Even though Nb substitution at only V‐site is next favorable, the band gap change is not very significant which agrees with an earlier experiment. However, it does change the electron effective mass by 20 % owing to the presence of Nb 4d bands in the conduction bands, which explains better catalytic activity by Nb‐doped BiVO4. In addition, application of external pressure the single‐phase stability zone in the chemical‐potential landscape. We have also focused on the local structural distortions near the Nb doping site, especially on the BiO8 octahedra. We have shown here that pressure‐induced symmetrization of BiO8 dodecahedron lowers the electron's effective mass further and therefore can help to improve the photoconduction property of BiVO4.
ArCH2+: A Detectable Noble Gas Molecule
Authors: Fortenberry Ryan C. , Ascenzi Daniela
Published: October 2018

The noble gas molecular cation, ArCH2+, has been observed in mass spectrometry experiments, and the present work is providing high‐level quantum chemical predictions for the vibrational and rotational spectroscopic data necessary to observe this molecule in situ in other laboratory conditions. The Ar−C stretch in this cation is a bright fundamental vibrational frequency that should be observable in the early regions of the far‐infrared at 421.2 cm−1 for the universally most common 36Ar isotope. The near‐prolate nature of this molecule and its 2.91 D dipole moment should also make it distinguishable for submillimeter detection, as well. Furthermore, the Ar−C bond strength in ArCH2+ is greater than the global minimum for the dissociation of the experimentally known ArOH+ cation. As a result, the infrared spectrum of this simple organo‐noble gas molecule is likely waiting to be observed and may already exist in the spectra of hydrocarbon cations in argon‐matrix condensed phase experiments.
DServ‐LB: Dynamic server load balancing algorithm
Authors: S Wilson Prakash , P Deepalakshmi
Published: October 2018

In recent years, web services have been largely accessed by the customer, and it increases the network traffic on the internet. To provide the services for the large number of customer, dynamic clustering concept has been implemented that provides the ability to add or remove the servers on demand. But managing and processing the large set of traffic are very complicated. Load balancing technic helps to resolve the problems of network traffic and give efficient network management. In this paper, we proposed a dynamic server load balancing algorithm (DServ‐LB) using OpenFlow switches in software‐defined networking. The OpenFlow switches support the dynamic programmability. Also, we used the sFlow protocol, which is used to monitor the servers resource information periodically and the controller. Based on the server resource availability, the controller installs forwarding rules in the OpenFlow switches. For implementation, we used Mininet for network emulation, POX controller, and Docker container as Mininet hosts. The result shows that the proposed DServ‐LB improves the overall network performance and efficiently utilizes the server resources if compared with existing load balancing algorithms.