bluuebunny/crossref_metadata_2025 huggingface dataset:
An oxorhenium complex bearing a chiral cyclohexane‐1‐olato‐2‐thiolato ligand: Synthesis, stereochemistry, and theoretical study of parity violation vibrational frequency shifts
Authors: Saleh Nidal , Bast Radovan , Vanthuyne Nicolas , Roussel Christian , Saue Trond , Darquié Benoît , Crassous Jeanne
Published: November 2017

In our effort towards measuring the parity violation energy difference between two enantiomers, a simple chiral oxorhenium complex 5 bearing enantiopure 2‐mercaptocyclohexan‐1‐ol has been prepared as a potential candidate species. Vibrational circular dichroism revealed a chiral environment surrounding the rhenium atom, even though the rhenium is not a stereogenic center itself, and enabled to assign the (1S,2S)‐(−) and (1R,2R)‐(+) absolute configuration for 5. For both compound 5 and complex 4, previously studied by us and bearing a propane‐2‐olato‐3‐thiolato ligand, relativistic calculations predict parity violating vibrational frequency differences of a few hundreds of millihertz, above the expected sensitivity attainable by a molecular beam Ramsey interferometer that we are constructing.
Biomimetic syntheses of racemic natural products
Authors: Zask Arie , Ellestad George
Published: November 2017

Racemic natural products are rarely produced in plants and microorganisms and are thought to be the result of nonenzymatic, spontaneous reactions. These compounds are often highly complex with multiple contiguous chiral centers that present a challenge to organic synthesis. Formation of these racemates often occurs by cyclization reactions that can generate multiple stereocenters from achiral precursors. Biomimetic synthesis of these racemic natural products provides support for their proposed nonenzymatic spontaneous biosynthesis. These elegant syntheses also provide scalable and efficient routes to these complex natural products. Although the number of reported racemic natural products is relatively low, an isolated natural product that has a very small optical rotation has been shown to be a true racemate. Thus, the occurrence of racemic natural products could be more common than thought.
Lipase‐catalyzed enantioselective transesterification of prochiral 1‐((1,3‐dihydroxypropan‐2‐yloxy)methyl)‐5,6,7,8‐tetrahydroquinazoline‐2,4(1H,3H)‐dione in ionic liquids
Authors: Kołodziejska Renata , Studzińska Renata , Pawluk Hanna
Published: November 2017

The application of ionic liquids as solvents for transesterification of prochiral pirymidine acyclonucleoside using lipase (EC 3.1.1.3) Amano PS from Burkholderia cepacia (BCL) is reported. The effect of using medium reaction, acyl group donor, and temperature on the activity and enantioselectivity of BCL was studied. From the investigated ionic solvents, the hydrophobic ionic liquid [BMIM]PF6] was the preferred medium for enzymatic reactions. However, the best result was obtained in the mixture [BMIM][PF6]:TBME (1:1 v/v) at 50°C. Enzyme activity and selectivity in [BMIM][PF6]:TBME (1:1 v/v) was slightly higher in than in conventional organic solvents (for example, TBME), and in this condition, good activity and enantioselectivity were associated with unique properties of ionic liquid such as hydrophobicity and high polarity. Independently of solvents, monester of (R)‐configuration was obtained in excess. Under optimal conditions, desymmetrization of the prochiral compound using different acyl donors was performed. If vinyl butyrate was used as the acylating agent, BCL completely selectively acylated enantiotopic hydroxyl groups.
LEGO‐Inspired Drug Design: Unveiling a Class of Benzo[d]thiazoles Containing a 3,4‐Dihydroxyphenyl Moiety as Plasma Membrane H+‐ATPase Inhibitors
Authors: Tung Truong‐Thanh , Dao Trong T. , Junyent Marta G. , Palmgren Michael , Günther‐Pomorski Thomas , Fuglsang Anja T. , Christensen Søren B. , Nielsen John
Published: November 2017

The fungal plasma membrane H+‐ATPase (Pma1p) is a potential target for the discovery of new antifungal agents. Surprisingly, no structure–activity relationship studies for small molecules targeting Pma1p have been reported. Herein, we disclose a LEGO‐inspired fragment assembly strategy for the design, synthesis, and discovery of benzo[d]thiazoles containing a 3,4‐dihydroxyphenyl moiety as potential Pma1p inhibitors. A series of 2‐(benzo[d]thiazol‐2‐ylthio)‐1‐(3,4‐dihydroxyphenyl)ethanones was found to inhibit Pma1p, with the most potent IC50 value of 8 μm in an in vitro plasma membrane H+‐ATPase assay. These compounds were also found to strongly inhibit the action of proton pumping when Pma1p was reconstituted into liposomes. 1‐(3,4‐Dihydroxyphenyl)‐2‐((6‐(trifluoromethyl)benzo[d]thiazol‐2‐yl)thio)ethan‐1‐one (compound 38) showed inhibitory activities on the growth of Candida albicans and Saccharomyces cerevisiae, which could be correlated and substantiated with the ability to inhibit Pma1p in vitro.
Anchoring a Sulfonate Group to an Electron‐Transporting Molecule by an Alkyl Chain and Its Use as the Counter Anion in a Phosphorescent Cationic Iridium Complex
Authors: Wang Pei , Luo Ningzi , Song Xiangzhi , He Lei
Published: November 2017

An electron‐transporting anion prepared by anchoring a sulfonate group onto an electron‐transporting molecule through a flexible alkyl chain and its use as the counter anion in a cationic iridium complex is reported. The flexible alkyl chain improves the solubility of the bulky anion in water or in polar organic solvents. The anion exhibits similar photophysical and electrochemical properties to the parent electron‐transporting molecule. Within the complex, the anion does not disturb the phosphorescence of the cation in the solid film. Solution‐processed small‐molecule organic light‐emitting diodes (OLEDs) using the complex as the dopant show superior performances over the reference device using the conventional complex with a PF6− counter anion. It is revealed that anchoring anionic groups to optoelectronically active molecules with flexible alkyl chains is a feasible approach to develop optoelectronically active anions for assembling ion pairs with advanced optoelectronic properties.
CRISPR/Cas9‐Based Safe‐Harbor Gene Editing in Rhesus iPSCs
Authors: Yada Ravi Chandra , Ostrominski John W. , Tunc Ilker , Hong So Gun , Zou Jizhong , Dunbar Cynthia E.
Published: November 2017

NHP iPSCs provide a unique opportunity to test safety and efficacy of iPSC‐derived therapies in clinically relevant NHP models. To monitor these cells in vivo, there is a need for safe and efficient labeling methods. Gene insertion into genomic safe harbors (GSHs) supports reliable transgene expression while minimizing the risk the modification poses to the host genome or target cell. Specifically, this protocol demonstrates targeting of the adeno‐associated virus site 1 (AAVS1), one of the most widely used GSH loci in the human genome, with CRISPR/Cas9, allowing targeted marker or therapeutic gene insertion in rhesus macaque induced pluripotent stem cells (RhiPSCs). Furthermore, detailed instructions for screening targeted clones and a tool for assessing potential off‐target nuclease activity are provided. © 2017 by John Wiley & Sons, Inc.
Tetramer bis‐(8‐hydroxyquinoline) Zinc Crystals Prepared by Physical Vapor Deposition Method
Authors: Wei Zhixian , Song Hui , Dai Chenghu , Chen Zhen , Yan Xueyu , Ji Ziwu , Pang Zhiyong , Han Shenghao
Published: November 2017

High quality single crystals of bis‐(8‐hydroxyquinoline) zinc (ZnQ2), a π‐conjugated molecular semiconductor with high thermal stability, good electron transport ability and excellent electroluminescence properties, were prepared by physical vapor deposition (PVD) method in a double zone tube furnace. X‐ray single crystal diffraction (XSCD) indicates that the sample was ZnO2 tetramer, (ZnQ2)4, with the triclinic unit cell parameters: a = 10.8537(15) Å, b = 11.8814(16) Å, c = 13.0532(18) Å, α = 74.119(2)°, β = 73.449(2)°, γ = 70.999(2)°, volume = 1494.9(4) Å3 and Z = 1. The crystallization mechanism analysis suggests a classical crystal growth process at low temperatures (300 and 320 °C) and an existence of non‐classical particle‐attachment crystal growth pathway at high temperature (340 °C). The (ZnQ2)4 crystals also show enhanced photoluminescence (PL) intensities and narrower full width at half maximum (FWHM) compared with that of the ZnQ2 thin film.
Decrease misconduct allegations among students on the spectrum
Authors: McCarthy Claudine
Published: November 2017

No doubt your campus has seen an increase in the number of students with autism spectrum disorder or Asperger's syndrome. Their social, behavioral, and communication challenges can lead to disruptions or misunderstandings among the campus community, often resulting in allegations of misconduct.
New guide helps students with mental health issues navigate university life
Authors: Novis David
Published: November 2017

Among college students, mental health problems are common. The 2016 National College Health Assessment reported that nearly 40 percent of students found themselves “so depressed it was difficult to function” within the previous 12 months — with 19 percent feeling “overwhelming anxiety,” and 10 percent “seriously considering suicide.” These numbers are alarming, as the pressure placed upon college students nowadays is only amplified and exasperated for those experiencing such a degree of anxiety, depression, and other mental health issues. Fortunately, however, the Judge David L. Bazelon Center for Mental Health Law has published “Campus Mental Health: Frequently Asked Questions” to help students with mental health disabilities on campus.
In Grid Protection, New Technologies Can Threaten and Secure Utilities
Authors: Hawkins Ronald
Published: November 2017

The risks and security challenges that utilities must manage have increased substantially in recent decades.
Genetic analysis of bentonite—Permian Wangpo shale in Liangshan, Hanzhong, South Shaanxi Province
Authors: Shao Tiequan , Tang Hanhua , Liu Yunhuan , Jiang Kaituo , Hu Bo , Jia Chenhui , Wang Qi , Zhang Yanan , Zhang Hu , Qin Jiachen
Published: November 2017

Fine pyroclastic materials form bentonites through subsidence, hydrolysis, and argillation in alkaline marine environments, which can further transform to K‐bentonite. Bentonites or K‐bentonites are quite popular with geologists because their formation often reflects geologic events. However, studies mainly focus on K‐bentonite, and research on ordinary bentonites in China is almost nonexistent. Recent research shows that the Wangpo shale consists of ordinary bentonites. Through thorough field investigations, indoor experimentation and analysis, and comparison of petrologic and geochemical characteristics of the Wangpo shale with K‐bentonites, this paper explores the nature and genesis of source rocks and provides a basis for the study of ordinary bentonites. The petrological study shows that the Wangpo shale is a montmorillonite vitric tuff, which is mainly composed of montmorillonite and small amounts of quartz, opal, and heulandite. These indicate that it is a typical bentonite. In addition, the rock contains an abundance of fossils reflecting a coastal–shallow sea depositional environment. We chose the elements with stable chemical characteristics for obtaining source rock characteristics, and the results showed that the Wangpo shale has a genetic relationship with neutral alkaline magma. As a boundary between the Upper Permian and the Middle Permian, the Wangpo shale has an internal connection with eruption of the Emeishan basalt in Southwest China. In combination with previous work, it can be inferred that studying the volcanic activity represented by the Wangpo shale plays an important role in studying Emeishan large igneous provinces and the end‐Guadalupian mass extinction.
The CEO as a key microfoundation of global strategy: Task demands, CEO origin, and the CEO's international background
Authors: Kunisch Sven , Menz Markus , Cannella Albert A.
Published: November 2017

Research Summary

We explore the selection of new CEOs with international backgrounds as a key microfoundation of global strategy. Building on executive succession, upper echelons, and international business research, we argue that firms choose CEOs with international backgrounds to match their task demands. We further argue that depending on the CEO's origin from inside or outside the firm, different task demands matter. Specifically, we propose that the relationship between internal (firm‐level) task demands and the new CEO's international background is more pronounced for inside successions, whereas the relationship between external (industry‐level) task demands and the new CEO's international background is more pronounced for outside successions. An analysis of a sample of 363 CEO successions in S&P 500 firms supports our reasoning.

Managerial Summary

Choosing a CEO with the “right” experience is a crucial concern for many large firms. While firms increasing seem to select new CEOs with international backgrounds, not all firms do so. In this article, we explore several factors that might influence this choice. Our results reveal that the predecessor's international background, the firm's level of internationalization, and the level of internationalization of the firm's industry influence whether a CEO with an international background is selected. Moreover, while for inside successions, the firm's level of internationalization is particularly important, for outside successions, the level of internationalization of the firm's industry is particularly important. Our findings inform those who search, select, and appoint new CEOs, including boards of directors and (executive search) consultants.
Association between structural brain network efficiency and intelligence increases during adolescence
Authors: Koenis Marinka M.G. , Brouwer Rachel M. , Swagerman Suzanne C. , van Soelen Inge L.C. , Boomsma Dorret I. , Hulshoff Pol Hilleke E.
Published: November 2017

Adolescence represents an important period during which considerable changes in the brain take place, including increases in integrity of white matter bundles, and increasing efficiency of the structural brain network. A more efficient structural brain network has been associated with higher intelligence. Whether development of structural network efficiency is related to intelligence, and if so to which extent genetic and environmental influences are implicated in their association, is not known. In a longitudinal study, we mapped FA‐weighted efficiency of the structural brain network in 310 twins and their older siblings at an average age of 10, 13, and 18 years. Age‐trajectories of global and local FA‐weighted efficiency were related to intelligence. Contributions of genes and environment were estimated using structural equation modeling. Efficiency of brain networks changed in a non‐linear fashion from childhood to early adulthood, increasing between 10 and 13 years, and leveling off between 13 and 18 years. Adolescents with higher intelligence had higher global and local network efficiency. The dependency of FA‐weighted global efficiency on IQ increased during adolescence (rph=0.007 at age 10; 0.23 at age 18). Global efficiency was significantly heritable during adolescence (47% at age 18). The genetic correlation between intelligence and global and local efficiency increased with age; genes explained up to 87% of the observed correlation at age 18. In conclusion, the brain's structural network differentiates depending on IQ during adolescence, and is under increasing influence of genes that are also associated with intelligence as it develops from late childhood to adulthood.
Preventive effects of tonsil‐derived mesenchymal stem cells on osteoradionecrosis in a rat model
Authors: Park Hae Sang , Lee Jihae , Kim Jin‐Woo , Kim Ha Young , Jung Soo Yeon , Lee Sung Min , Park Chan Hum , Kim Han Su
Published: November 2017

Background

The purpose of this study was to investigate the effects of tonsil‐derived mesenchymal stem cells (MSCs) on osteoradionecrosis (ORN).

Method

We generated a mandibular ORN rat model using a combination of 20‐Gy single‐dose irradiation and tooth extraction. Study groups were negative control (tooth extraction only), ORN group (irradiation, tooth extraction), Matrigel‐1 group (Matrigel; BD Biosciences, San Jose, CA; irradiation, Matrigel application immediately after tooth extraction), tonsil‐derived MSC‐1 group (irradiation, tonsil‐derived MSC application immediately after tooth extraction), Matrigel‐4 group (irradiation, Matrigel application 4 weeks after tooth extraction), and tonsil‐derived MSC‐4 group (irradiation, tonsil‐derived MSC application 4 weeks after tooth extraction).

Result

Bone mineral density was significantly lower in the ORN group than in the negative control group. The tonsil‐derived MSC‐1 group showed significantly higher bone mineral density than did the ORN and tonsil‐derived MSC‐4 groups.

Conclusion

A single 20‐Gy dose of irradiation combined with tooth extraction successfully generated ORN in the rat model. The tonsil‐derived MSCs can be effective for bone regeneration in ORN, particularly when applied immediately after dentoalveolar trauma or surgery.
Complications of double free flap and free flap combined with locoregional flap in head and neck reconstruction: A systematic review
Authors: Chen Collin L. , Zenga Joseph , Roland Lauren T. , Pipkorn Patrik
Published: November 2017

Background

The purpose of this clinical review was to assess the feasibility of reconstructing complex head and neck defects with 2 or more free flaps simultaneously.

Methods

A total of 38 articles were reviewed. The patient population included those who received 2 or more free flaps or a single free flap plus a locoregional flap. The primary outcome assessed was rate of complications.

Results

Among double flaps, the minor complication rate was 6.96% and the major complication rate was 20.0%. In comparison, the free flap plus locoregional flap group had higher rates of minor and major complications of 30.4% and 29.5%, respectively. The median operating time was 660 minutes for double flaps and 602 minutes for free flap plus locoregional flap (P = .828).

Conclusion

Compared to the single free flap plus locoregional flap, double free flaps are relatively reliable without increasing surgical complications or decreasing flap survival, while only modestly increasing operating times.
β‐Catenin and interleukin‐1β–dependent chemokine (C‐X‐C motif) ligand 10 production drives progression of disease in a mouse model of congenital hepatic fibrosis
Authors: Kaffe Eleanna , Fiorotto Romina , Pellegrino Francesca , Mariotti Valeria , Amenduni Mariangela , Cadamuro Massimiliano , Fabris Luca , Strazzabosco Mario , Spirli Carlo
Published: November 2017

Congenital hepatic fibrosis (CHF), a genetic disease caused by mutations in the polycystic kidney and hepatic disease 1 (PKHD1) gene, encoding for the protein fibrocystin/polyductin complex, is characterized by biliary dysgenesis, progressive portal fibrosis, and a protein kinase A–mediated activating phosphorylation of β‐catenin at Ser675. Biliary structures of Pkhd1del4/del4
mice, a mouse model of CHF, secrete chemokine (C‐X‐C motif) ligand 10 (CXCL10), a chemokine able to recruit macrophages. The aim of this study was to clarify whether CXCL10 plays a pathogenetic role in disease progression in CHF/Caroli disease and to understand the mechanisms leading to increased CXCL10 secretion. We demonstrate that treatment of Pkhd1del4/del4
mice for 3 months with AMG‐487, an inhibitor of CXC chemokine receptor family 3, the cognate receptor of CXCL10, reduces the peribiliary recruitment of alternative activated macrophages (cluster of differentiation 45+F4/80+ cells), spleen size, liver fibrosis (sirius red), and cyst growth (cytokeratin 19–positive area), consistent with a pathogenetic role of CXCL10. Furthermore, we show that in fibrocystin/polyductin complex–defective cholangiocytes, isolated from Pkhd1del4/del4
mice, CXCL10 production is mediated by Janus kinase/signal transducer and activator of transcription 3 in response to interleukin 1beta (IL‐1β) and β‐catenin. Specifically, IL‐1β promotes signal transducer and activator of transcription 3 phosphorylation, whereas β‐catenin promotes its nuclear translocation. Increased pro‐IL‐1β was regulated by nuclear factor kappa‐light‐chain‐enhancer of activated B cells, and increased secretion of active IL‐1β was mediated by the activation of Nod‐like receptors, pyrin domain containing 3 inflammasome (increased expression of caspase 1 and Nod‐like receptors, pyrin domain containing 3). Conclusion: In fibrocystin/polyductin complex–defective cholangiocytes, β‐catenin and IL‐1β are responsible for signal transducer and activator of transcription 3–dependent secretion of CXCL10; in vivo experiments show that the CXCL10/CXC chemokine receptor family 3 axis prevents the recruitment of macrophages, reduces inflammation, and halts the progression of the disease; the increased production of IL‐1β highlights the autoinflammatory nature of CHF and may open novel therapeutic avenues. (Hepatology 2018;67:1903‐1919).
Infiltration into frozen soil: From core‐scale dynamics to hillslope‐scale connectivity
Authors: Appels Willemijn M. , Coles Anna E. , McDonnell Jeffrey J.
Published: November 2017

Infiltration into frozen soil is a key hydrological process in cold regions. Although the mechanisms behind point‐scale infiltration into frozen soil are relatively well understood, questions remain about upscaling point‐scale results to estimate hillslope‐scale run‐off generation. Here, we tackle this question by combining laboratory, field, and modelling experiments. Six large (0.30‐m diameter by 0.35‐m deep) soil cores were extracted from an experimental hillslope on the Canadian Prairies. In the laboratory, we measured run‐off and infiltration rates of the cores for two antecedent moisture conditions under snowmelt rates and diurnal freeze–thaw conditions observed on the same hillslope. We combined the infiltration data with spatially variable data from the hillslope, to parameterise a surface run‐off redistribution model. We used the model to determine how spatial patterns of soil water content, snowpack water equivalent (SWE), and snowmelt rates affect the spatial variability of infiltration and hydrological connectivity over frozen soil. Our experiments showed that antecedent moisture conditions of the frozen soil affected infiltration rates by limiting the initial soil storage capacity and infiltration front penetration depth. However, shallow depths of infiltration and refreezing created saturated conditions at the surface for dry and wet antecedent conditions, resulting in similar final infiltration rates (0.3 mm hr−1). On the hillslope‐scale, the spatial variability of snowmelt rates controlled the development of hydrological connectivity during the 2014 spring melt, whereas SWE and antecedent soil moisture were unimportant. Geostatistical analysis showed that this was because SWE variability and antecedent moisture variability occurred at distances shorter than that of topographic variability, whereas melt variability occurred at distances longer than that of topographic variability. The importance of spatial controls will shift for differing locations and winter conditions. Overall, our results suggest that run‐off connectivity is determined by (a) a pre‐fill phase, during which a thin surface soil layer wets up, refreezes, and saturates, before infiltration excess run‐off is generated and (b) a subsequent fill‐and‐spill phase on the surface that drives hillslope‐scale run‐off.
Delivery outcomes of large‐for‐gestational‐age newborns stratified by the presence or absence of gestational diabetes mellitus
Authors: Rosen Hadar , Shmueli Anat , Ashwal Eran , Hiersch Liran , Yogev Yariv , Aviram Amir
Published: November 2017

Objective

To evaluate separate and combined contributions of gestational diabetes mellitus (GDM) and large‐for‐gestational age (LGA) on delivery outcomes.

Methods

In a retrospective cohort study of term singleton deliveries between 2007 and 2014 in Tel Aviv, Israel, outcomes were compared between non‐GDM/AGA pregnancies (reference) and three study groups: non‐GDM/LGA, GDM/appropriate for gestational age (AGA) and GDM/LGA.

Results

Overall, there were 62 102 deliveries, of which 53 201 (85.7%) were eligible for inclusion. Of these, 43 775 (82.3%) were non‐GDM/AGA, 6441 (12.1%) non‐GDM/LGA, 2351 (4.4%) GDM/AGA, and 634 (1.2%) GDM/LGA. Compared with the reference group, the study groups had higher mean maternal age and higher rates of previous cesarean delivery, polyhydramnios, induction of labor, and cesarean delivery. Considering only women attempting vaginal delivery, the three groups were independently associated with adverse outcomes including cesarean delivery (adjusted odds ratio [aOR], 1.5, 1.6, and 2.6 for non‐GDM/LGA, GDM/AGA, and GDM/LGA, respectively), mainly for prolonged first stage of labor, and hypoglycemia (aOR, 1.9, 2.5, and 4.6, respectively). LGA with and without GDM was associated with shoulder dystocia (aOR, 14.5 and 6.9, respectively), prolonged second stage, and jaundice.

Conclusion

GDM and LGA share similarities in pregnancy complications. The presence of both has a cumulative impact.
A polyelectrolyte multilayer platform for investigating growth factor delivery modes in human liver cultures
Authors: Lin Christine , Romero Raimundo , Sorokina Lioudmila V. , Ballinger Kimberly R. , Place Laura W. , Kipper Matt J. , Khetani Salman R.
Published: November 2017

Polyelectrolyte multilayers (PEMs) of chitosan and heparin are useful for mimicking growth factor (GF) binding to extracellular matrix (ECM) as in vivo. Here, we developed a PEM platform for delivering bound/adsorbed GFs to monocultures of primary human hepatocytes (PHHs) and PHH/non‐parenchymal cell (NPC) co‐cultures, which are useful for drug development and regenerative medicine. The effects of ECM protein coating (collagen I, fibronectin, and Matrigel®) and terminal PEM layer on PHH attachment/functions were determined. Then, heparin‐terminated/fibronectin‐coated PEMs were used to deliver varying concentrations of an adsorbed model GF, transforming growth factor β (TGFβ), to PHH monocultures while using soluble TGFβ delivery via culture medium as the conventional control. Soluble TGFβ delivery caused a severe, monotonic, and sustained downregulation of all PHH functions measured (albumin and urea secretions, cytochrome‐P450 2A6 and 3A4 enzyme activities), whereas adsorbed TGFβ delivery caused transient upregulation of 3 out of 4 functions. Finally, functionally stable co‐cultures of PHHs and 3T3‐J2 murine embryonic fibroblasts were created on the heparin‐terminated/fibronectin‐coated PEMs modified with adsorbed TGFβ to elucidate similarities and differences in functional response relative to the monocultures. In conclusion, chitosan‐heparin PEMs constitute a robust platform for investigating the effects of GF delivery modes on PHH monocultures and PHH/NPC co‐cultures. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 971–984, 2018.
Validation of the distress tolerance scale‐short form in obsessive compulsive disorder
Authors: Garner Lauryn E. , Van Kirk Nathaniel , Tifft Eric D. , Krompinger Jason W. , Mathes Brittany M. , Fraire Maria , Falkenstein Martha J. , Brennan Brian P. , Crosby Jesse M. , Elias Jason A.
Published: November 2017

Objective

This study aimed to develop and validate the Distress Tolerance Scale‐Short Form (DTS‐SF), a modification of the original Distress Tolerance Scale, in a severe/complex sample of individuals with obsessive compulsive disorder (OCD). Currently, there are multiple self‐report measurements of distress tolerance (DT), highlighting the need for a more refined measure.

Method

Participants included 222 individuals with a primary diagnosis of OCD (57% male, average age = 31) seeking intensive/residential treatment. Participants completed surveys at admission, discharge, and each week.

Results

An exploratory factor analysis revealed a one‐factor solution representing overall DT ability. The DTS‐SF was found to be sensitive to treatment effects. Appropriate associations between the DTS‐SF and other measures were also found, with lower DT associated with greater OCD and depression severity and lower reported quality of life.

Conclusion

The DTS‐SF was found to be a valid and reliable measure with high clinical utility for quickly and accurately measuring DT.
The effects of reinforcer magnitude in the preceding and upcoming ratios on between‐ratio pausing in multiple, mixed, and single fixed‐ratio schedules
Authors: Young Rachel , Foster T. Mary , Bizo Lewis A.
Published: November 2017

Hens responded under multiple fixed‐ratio schedules with equal response requirements and either a 1‐s or a 6‐s reinforcer. Upcoming reinforcer size was indicated by key color. Components were presented in a quasirandom series so that all four component transitions occurred. Postreinforcement pauses were affected by the upcoming and preceding reinforcer size, with longer pauses after large reinforcers followed by small reinforcers than when followed by large ones, and longer pauses after small reinforcers that were followed by small reinforcers rather than large ones. Pauses increased with fixed‐ratio size and the effects of reinforcer size were larger the larger the ratio. When reinforcer size was not signaled—mixed fixed‐ratio schedules—pauses were shorter after small than after large reinforcers. Signalling the upcoming reinforcer attenuated the effect of the previous reinforcer size on pause duration when small was followed by small and when either small or large by large, but enhanced the effect when large was followed by small. There was no effect of reinforcer size on pause duration when single fixed‐ratio schedules were arranged. The effects of reinforcer size on pauses depends on the size and range of the fixed ratios as well as the exact procedures used in the study.
Engineering Students' Epistemic Cognition in the Context of Problem Solving
Authors: Faber Courtney , Benson Lisa C.
Published: November 2017

Background

Students' beliefs about knowledge (epistemic beliefs) and their motivations toward processing information (epistemic motivation) have been suggested as influencing aspects of learning.

Purpose

This study investigated the relationship between engineering students' approach to solving an open‐ended homework problem and their epistemic motivation, engineering epistemic beliefs, and epistemic cognition.

Methods

The initial quantitative phase of this sequential explanatory mixed methods study employed a k‐means cluster analysis to identify homogenous subgroups of biomedical engineering students based on their epistemic beliefs and epistemic motivation measured using a survey (n= 50). Eighteen of these students were interviewed to explore their epistemic cognitions when solving an open‐ended homework problem. Transcripts were analyzed and results were overlaid with the clusters to investigate relationships between students' approaches to problem solving and their epistemic beliefs, motivation, and cognition.

Results

Three clusters of students were identified based on three constructs of epistemic beliefs and epistemic motivation: source of engineering knowledge, certainty of engineering knowledge, and closed‐mindedness. Students in the same cluster activated similar components of epistemic cognition, such as their desired outcomes for solving the problem. Additionally, we identified that the instructor's description of the problem and how the assignment was structured influenced how students approached solving the problem.

Conclusions

Comparison of clusters revealed that having more constructivist epistemic beliefs does not guarantee that students will set epistemic aims or make epistemic gains. Additionally, students' approaches to solving the open‐ended problem were influenced by their lack of desire to consider other ideas. The outcomes of this study provide a more complete understanding of students' epistemic cognitions and beliefs related to problem solving in the classroom.
On unavoidable‐induced subgraphs in large prime graphs
Authors: Malliaris M. , Terry C.
Published: November 2017

Chudnovsky, Kim, Oum, and Seymour recently established that any prime graph contains one of a short list of induced prime subgraphs [1]. In the present article, we reprove their theorem using many of the same ideas, but with the key model‐theoretic ingredient of first determining the so‐called amount of stability of the graph. This approach changes the applicable Ramsey theorem, improves the bounds and offers a different structural perspective on the graphs in question. Complementing this, we give an infinitary proof that implies the finite result.
Preparation and comparative evaluation of 99mTc‐HYNIC‐cNGR and 99mTc‐HYNIC‐PEG2‐cNGR as tumor‐targeting molecular imaging probes
Authors: Vats Kusum , Satpati Drishty , Sharma Rohit , Kumar Chandan , Sarma Haladhar Dev , Banerjee Sharmila
Published: November 2017

The tripeptide sequence asparagine‐glycine‐arginine (NGR) specifically recognizes aminopeptidase N (APN or CD13) receptors highly expressed on tumor cells and vasculature. Thus, NGR peptides can precisely deliver therapeutic and diagnostic compounds to CD13 expressing cancer sites. In this regard, 2 NGR peptide ligands, HYNIC‐c(NGR) and HYNIC‐PEG2‐c(NGR), were synthesized, radiolabeled with 99mTc, and evaluated in CD13‐positive human fibrosarcoma HT‐1080 tumor xenografts. The radiotracers, 99mTc‐HYNIC‐c(NGR) and 99mTc‐HYNIC‐PEG2‐c(NGR), could be prepared in approximately 95% radiochemical purity and exhibited excellent in vitro and in vivo stability. The radiotracers were hydrophilic in nature with log P values being −2.33 ± 0.05 and −2.61 ± 0.08. The uptake of 2 radiotracers 99mTc‐HYNIC‐c(NGR) and 99mTc‐HYNIC‐PEG2‐c(NGR) was similar in nude mice bearing human fibrosarcoma HT‐1080 tumor xenografts, which was significantly reduced (P < .05) during blocking studies. The 2 radiotracers being hydrophilic cleared rapidly from blood, liver, and intestine and were excreted through renal pathway. The pharmacokinetics of 99mTc‐labeled HYNIC peptide could not be modulated through introduction of PEG2 unit, thus posing a challenge for studies with other linkers towards enhanced tumor uptake and retention.
A synthesis of [14C]sodium ferrocyanide decahydrate
Authors: Egan Judith A. , Filer Crist N.
Published: November 2017

The 2‐step synthesis of [14C]sodium ferrocyanide decahydrate is described. Ferrous hydroxide was prepared from iron powder and then reacted with [14C]sodium cyanide to afford the product. The [14C]sodium ferrocyanide decahydrate was characterized by HPLC and 13C NMR.
Topical adjuvants incompletely remove adherent Staphylococcus aureus from implant materials
Authors: Ernest Emily P. , Machi Anthony S. , Karolcik Brock A. , LaSala Paul R. , Dietz Matthew J.
Published: November 2017

Adjuvant treatments including Betadine, Dakin's solution (sodium hypochlorite), or hydrogen peroxide (H2O2) have been attempted to eradicate prosthetic joint infection caused by biofilm or intracellular bacteria. The purpose of this study was to evaluate the in vitro abilities of chemical adjuvants to decrease Staphylococcus aureus (S. aureus) biofilm presence on orthopaedic implant grade materials, including titanium, stainless steel, and cobalt chrome. S. aureus biofilms were grown for 48 h and evaluated for baseline colony forming units/centimeter squared (CFU/cm2) and compared to treatments with Betadine, Dakin's solution, H2O2, or 1% chlorine dioxide (ClO2). Control discs (n = 18) across all metals had an average of 4.2 × 107 CFU/cm2. All treatments had statistically significant reductions in CFU/cm2 when compared to respective control discs (p < 0.05). For all metals combined, the most efficacious treatments were Betadine and H2O2, with an average 98% and 97% CFU/cm2 reduction, respectively. There were no significant differences between reductions seen with Betadine and H2O2, but both groups had statistically greater reductions than Dakin's solution and ClO2. There was no change in antibiotic resistance patterns after treatment. Analysis of S. aureus biofilms demonstrated a statistically significant reduction in biofilm after a five‐minute treatment with the modalities, with an average two log reduction in CFU/cm2. Statement of clinical significance: While statistically significant reductions in CFU/cm2 were accomplished with chemical adjuvant treatments, the overall concentration of bacteria never fell below 105 CFU/cm2, leading to questionable clinical significance. Further techniques to eradicate biofilm should be investigated. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1599–1604, 2018.
Development of a high‐throughput method based on thin‐film microextraction using a 96‐well plate system with a cork coating for the extraction of emerging contaminants in river water samples
Authors: Morés Lucas , Dias Adriana Neves , Carasek Eduardo
Published: November 2017

In this study, a new method was developed in which a biosorbent material is used as the extractor phase in conjunction with a recently described sample preparation technique called thin‐film microextraction and a 96‐well plate system. The method was applied for the determination of emerging contaminants, such as 3‐(4‐methylbenzylidene) camphor, ethylparaben, triclocarban, and bisphenol A in water samples. The separation and detection of the analytes were performed by high‐performance liquid chromatography with diode array detection. These contaminants are considered hazardous to human health and other living beings. Thus, the development of an analytical method to determine these compounds is of great interest. The extraction parameters were evaluated using multivariate and univariate optimization techniques. The optimum conditions for the method were 3 h of extraction time, 20 min of desorption with 300 μL of acetonitrile and methanol (50:50, v/v), and the addition of 5% w/v sodium chloride to the sample. The analytical figures of merit showed good results with linear correlation coefficients higher than 0.99, relative recoveries of 72–125%, interday precision (n = 3) of 4–18%, and intraday precision (n = 9) of 1–21%. The limit of detection was 0.3–5.5 μg/L, and the limit of quantification was 0.8–15 μg/L.
Kill rates and predation rates of wolves on beavers
Authors: Gable Thomas D. , Windels Steve K.
Published: November 2017

Wolves (Canis lupus) can be primary predators of beavers (Castor canadensis), but little is known about wolf‐beaver dynamics. We identified kills from 1 wolf (V009) of the Ash River Pack in Voyageurs National Park from 1 April to 5 November 2015 to provide direct estimates of wolf pack kill and predation rates of beavers. We documented 12 beaver kills by V009 during the 2015 ice‐free season and estimated V009 killed 22 beavers during this period. Based on the number of beavers killed by V009, we estimated the Ash River Pack removed 80–88 beavers (kill rate of 0.085–0.095 beavers/wolf/day), which was 38–42% of the beaver population in their home range during the ice‐free season. Even with this substantial level of predation in 2015, the beaver population in the Ash River Pack home range increased by an estimated 43% in 2016, which suggested dispersal from more densely populated adjacent areas likely compensated for the effects of wolf predation. We have presented the first direct estimate of wolf kill and predation rates on beavers, but more research is necessary to understand how wolf predation affects beaver populations under a variety of conditions. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.
Managed movement increases metapopulation viability of the endangered red wolf
Authors: Simonis Juniper L. , Harrison Rebecca B. , Long Sarah T. , Rabon David R. , Waddell William T. , Faust Lisa J.
Published: November 2017

Movement connects otherwise isolated populations, influencing demographic persistence and promoting gene flow. We evaluated the effect of movement on the genetic and demographic viability of the red wolf (Canis rufus) and tested the application of metapopulation theory to management of this endangered predator. The establishment of a captive subpopulation in the 1970s allowed persistence of the species and facilitated a reintroduction program that supported 2 wild subpopulations, one of which persists today. We assessed the effect of historical and potential future movement between the wild and captive subpopulations on the genetic and demographic viability of the metapopulation. We analyzed approximately 30 years of individual‐level data to quantify the effects of historical movement among subpopulations and constructed an individual‐based metapopulation model to predict the effects of future potential movement (i.e., releases of captive wolves) on the species’ persistence and genetic diversity. Counter to theory, increased movement has had positive demographic effects, with higherper capitamovement rates leading to increased metapopulation growth and decreased subpopulation synchrony. These counter‐theoretical results are likely due to differences in reproduction and survival rates among subpopulations and the small size of the metapopulation. Furthermore, higher rates of movement did not increase retention of genetic diversity, likely because of the active pedigree‐based breeding management of the species already maximizing gene retention. Our model indicates that future releases of captive wolves are necessary, but not sufficient, for the survival of the species, and must be combined with changes to demographic rates in both the captive and northeastern North Carolina subpopulations. Our results highlight the need for models and field data that more adequately describe the viability of small metapopulations. © 2017 The Wildlife Society.
Metal‐Dielectric Nanocavity for Real‐Time Tracing Molecular Events with Temperature Feedback
Authors: Milichko Valentin A. , Zuev Dmitry A. , Baranov Denis G. , Zograf George P. , Volodina Katerina , Krasilin Andrei A. , Mukhin Ivan S. , Dmitriev Pavel A. , Vinogradov Vladimir V. , Makarov Sergey V. , Belov Pavel A.
Published: November 2017

Plasmonic nanoparticles coupled with metallic films forming nanometer scale cavities have recently emerged as a powerful tool for enhancement of light‐matter interaction. Despite high efficiency for sensing and light emission, such nanocavities exhibit harmful and uncontrolled optical heating which limits the ranges of light intensities and working temperature. In contrast to plasmonic nanoparticles, all‐dielectric counterparts possess low Ohmic losses, high temperature stability along with a strong temperature‐dependent Raman response. Here, we demonstrate that a silicon nanoparticle coupled with a thin gold film can serve as a multifunctional metal‐dielectric (hybrid) nanocavity operating up to 1200 K. Resonant interaction of light with such nanocavity enables molecular sensing, heat‐induced molecular events (protein unfolding), and their real‐time tracing with a nanoscale thermometry through the monitoring enhanced Raman scattering both from the nanoparticle and analyzed molecules. We model numerically the thermo‐optical properties of the hybrid nanocavity and reveal two alternative regimes of operation ‐ with and without strong optical heating while other functionalities are preserved. We believe that the concept of the multifunctional hybrid nanocavities holds great potential for diverse photochemical and photophysical applications.
RAFT Polymerization for the Synthesis of Tertiary Amine‐Based Diblock Copolymer Nucleic Acid Delivery Vehicles
Authors: McClellan Annie K. , Hao Taisen , Brooks Tracy A. , Smith Adam E.
Published: November 2017

The synthesis and characterization of a family of nine pH‐responsive, diblock copolymers designed to effectively deliver nucleic acids are reported. The stabilizing A block is comprised of an oligo(ethylene glycol) methyl ether methacrylate to impart water solubility. The cationic blocks of varying degrees of polymerization (DPs) are derived from three pH responsive, tertiary amine‐containing methacrylates capable of complexing negatively charged nucleic acids. The cytotoxicity studies utilizing human embryonic kidney cells (HEK‐293) and Michigan Cancer Foundation‐7 (MCF‐7) breast cancer cells indicate no decrease of cell viability with the diblock copolymers, with the exception of the two highest DPs of the cationic blocks with ethyl‐substitutes tertiary amine. Gene knockdown experiments indicate high siRNA delivery and MYC gene knockdown in MCF‐7 breast cancer cells for eight of the nine studied block copolymers. The results of the current study enable further development of the pH‐responsive copolymer family for promising nucleic acid delivery vehicles applicable for clinical use.
Energy Consumption for the Desalination of Salt Water Using Polyelectrolyte Hydrogels as the Separation Agent
Authors: Arens Lukas , Albrecht Julius B. , Höpfner Johannes , Schlag Karin , Habicht Axel , Seiffert Sebastian , Wilhelm Manfred
Published: November 2017

The energy consumption for a novel desalination approach using charged hydrogels under externally applied pressure is experimentally measured and calculated. The salt separation is based on a partial rejection of mobile salt ions caused by the fixed charges inside the polyelectrolyte network. Self‐synthesized and commercial poly(acrylic acid) hydrogels are used to study the desalination performance in reference to sodium chloride solutions within the concentration range of 0.1–35 g L−1. The influence of various synthetic parameters, such as the degree of crosslinking (DC) and the size and shape of the particles, is investigated. Furthermore, the effect of process parameters including the amount of the feed solution, the applied pressure profile, and the swelling time of the hydrogel is discussed. The best energy estimation found so far, is 8.9 kWh m−3 fresh water if a poly(acrylic acid) with a DC of 5 mol% is used in an infinite large salt bath.
Unexpected Large Depression of VPTT of a PNIPAM Microgel by Low Concentration of PVA
Authors: Tang Zhuo , Weng Junying , Guan Ying , Zhang Yongjun
Published: November 2017

Many low molecular weight and polymeric additives are found to be able to shift the phase transition temperature of poly(N‐isopropylacrylamide) (PNIPAM), however, a large change can only be observed at a high concentration of the additive. Particularly, poly(vinyl alcohol) (PVA), a polymeric additive, can only induce a very small change in the phase transition temperature of PNIPAM, even at a high concentration. Unexpectedly, it is found that a low concentration of PVA can dramatically reduce the volume phase transition temperature (VPTT) of the surface layer of poly(N‐isopropylacrylamide‐co‐2‐acrylamido‐phenylboronic acid) (P(NIPAM‐2‐AAPBA)) microgel. The concentration of PVA is about three orders of magnitude lower than the required concentration for other additives to achieve a comparable decrease in phase transition temperature of PNIPAM. The lowered VPTT cannot be explained by a change in the ionization degree of the PBA groups, or cross‐link density, or hydrophilicity–hydrophobicity balance of the gel. Instead, it is proposed that the adsorption of PVA chains onto the P(NIPAM‐2‐AAPBA) microgel spheres shortens the distance between the PVA and PNIPAM chains, allowing they influence the thermal behavior of PNIPAM more effectively and hence dramatically reducing the phase transition temperature of the latter.