bluuebunny/crossref_metadata_2025 huggingface dataset:
New Insights into the Nature of Co‐components and Their Impact on Pd Structure: X‐ray Absorption Studies on Toluene Acetoxylation Catalysts
Authors: Gatla Suresh , Radnik Jörg , Madaan Neetika , Pohl Marga‐Martina , Mathon Olivier , Rogalev Andrei , Narayana Kalevaru Venkata , Martin Andreas , Pascarelli Sakura , Brückner Angelika
Published: September 2015

Co‐components are a powerful tool to tune the performance of catalysts, but their nature and their impact on the catalysts is often controversially discussed. In this study X‐ray absorption spectroscopy (XAS) was employed to elucidate the nature of co‐components and their impact on the catalytic reaction. In anatase‐supported Pd‐based catalysts for the gas‐phase acetoxylation of toluene, less noble co‐components (e.g., Mn, Co, and Sb) spread over the support in their oxidic form and changed their valence state on stream. Incorporated atoms such as C or a small part of the Sb affect the electronic structure of Pd. For the noble Au, only a weak interaction with the support and Pd was observed during time on stream. Only XAS at the K‐edges together with investigations of the Pd L‐edge for a better understanding of the electronic structure, supplemented by STEM for elemental mapping, allow such detailed insights.
Regio‐ and Diastereoselective and Enantiospecific Metal‐Free C(sp3)H Arylation: Facile Access to Optically Active 5‐Aryl 2,5‐Disubstituted Pyrrolidines
Authors: Haldar Surajit , Roy Subhra Kanti , Maity Bholanath , Koley Debasis , Jana Chandan K.
Published: September 2015

Optically active 5‐aryl 2,5‐disubstituted pyrrolidines are the principal structural moiety of many bioactive compounds including natural products and catalysts for asymmetric synthesis. A highly regio‐ and diastereoselective and enantiospecific method for direct CH arylation of aliphatic amine has been developed. Structurally diverse enantiopure arylated pyrrolidines were synthesized from commercially available starting materials, through a single‐step three‐component reaction under metal‐ and oxidant‐free conditions. Furthermore, the complex analogous structure of CCK antagonist RP 66803 and angiotensin‐converting enzyme inhibitors was easily constructed using the synthesized arylated pyrrolidine derivative. Detailed theoretical calculations (M06‐2X/TZVPP/SMD//M06‐2X/6‐31+G(d,p) level) were also carried to investigate the mechanism and high level of stereocontrol involved in this direct sp3 CH arylation reaction. Preference for a given regio‐ and stereoselectivity in the arylated product can be explained through elucidation of the mechanism for dehydration, generating azomethine ylide, and for the final re‐aromatization step. The calculated energies reveals that the re‐aromatization step is essentially rate determining, accompanying an activation barrier of Δ≠=25.6 kcal mol−1.
On the Critical Effect of the Metal (Mo vs. W) on the [3+2] Cycloaddition Reaction of M3S4 Clusters with Alkynes: Insights from Experiment and Theory
Authors: Bustelo Emilio , Gushchin Artem L. , Fernández‐Trujillo M. Jesús , Basallote Manuel G. , Algarra Andrés G.
Published: September 2015

Whereas the cluster [Mo3S4(acac)3(py)3]+ ([1]+, acac=acetylacetonate, py=pyridine) reacts with a variety of alkynes, the cluster [W3S4(acac)3(py)3]+ ([2]+) remains unaffected under the same conditions. The reactions of cluster [1]+ show polyphasic kinetics, and in all cases clusters bearing a bridging dithiolene moiety are formed in the first step through the concerted [3+2] cycloaddition between the CC atoms of the alkyne and a Mo(μ‐S)2 moiety of the cluster. A computational study has been conducted to analyze the effect of the metal on these concerted [3+2] cycloaddition reactions. The calculations suggest that the reactions of cluster [2]+ with alkynes feature ΔG≠ values only slightly larger than its molybdenum analogue, however, the differences in the reaction free energies between both metal clusters and the same alkyne reach up to approximately 10 kcal mol−1, therefore indicating that the differences in the reactivity are essentially thermodynamic. The activation strain model (ASM) has been used to get more insights into the critical effect of the metal center in these cycloadditions, and the results reveal that the change in reactivity is entirely explained on the basis of the differences in the interaction energies Eint between the cluster and the alkyne. Further decomposition of the Eint values through the localized molecular orbital‐energy decomposition analysis (LMO‐EDA) indicates that substitution of the Mo atoms in cluster [1]+ by W induces changes in the electronic structure of the cluster that result in weaker intra‐ and inter‐fragment orbital interactions.
Cobalt(III) Chaperone Complexes of Curcumin: Photoreduction, Cellular Accumulation and Light‐Selective Toxicity towards Tumour Cells
Authors: Renfrew Anna K. , Bryce Nicole S. , Hambley Trevor
Published: September 2015

Light‐activated prodrugs offer the potential for highly selective tumour targeting. However, the application of many photoactivated chemotherapeutics is limited by a requirement for oxygen, or for short activation wavelengths that can damage surrounding tissue. Herein, we present a series of cobalt(III)‐curcumin prodrugs that can be activated by visible light under both oxygenated and hypoxic conditions. Furthermore, the photoproduct can be controlled by the activation wavelength: green light yields free curcumin, whereas blue light induces photolysis of curcumin to a phototoxic product. Confocal fluorescence microscopy and phototocytotoxicity studies in DLD‐1 and MCF‐7 tumour cells demonstrated that the cobalt(III) prodrugs are nontoxic in the dark but accumulate in significant concentrations in the cell membrane. When cells were treated with light for 15  min, the cytotoxicity of the cobalt complexes increased by up to 20‐fold, whereas free curcumin exhibited only a two‐fold increase in cytotoxicity. The nature of the ancillary ligand and cobalt reduction potential were found to strongly influence the stability and biological activity of the series.
A Comparative Study of Nutrients, Cadmium, and Chromium Bioremoval Efficiencies of Three Emergent Macrophytes From a Metal‐Contaminated Wastewater
Authors: Kouki Soulwène , Saidi Neila , M'hiri Fadhel , Hafiane Amor
Published: September 2015

A comparative study of the metal tolerance and removal capacities of three emergent macrophyte species was established in an artificially contaminated wastewater. The removal efficiencies of chromium (Cr), cadmium (Cd), ammoniacal‐nitrogen (NH4‐N), nitrate‐nitrogen (NO3‐N), and ortho‐phosphate (PO4‐P) by mono‐cultures of Arundo donax, Phragmites communis, and Typha latifolia were determined. The leaf number as well as Cr‐ and Cd‐plant tissue contents were assessed after 15 days of exposure to metal concentration gradients. Arundo donax achieved the highest removal efficiencies of NH4‐N (72%) and PO4‐P (83%). However, P. communis and T. latifolia accomplished significantly higher reduction rates of NO3‐N (86 and 82%, respectively). With exposure to the wastewater metal contamination, A. donax was more resistant than the other two species and produced the highest leaf number for both pollutants Cr (13 leaves at 20 mg Cr/L) and Cd (14 leaves at 2 ppm). In addition, compared to P. communis and T. latifolia, A. donax showed significantly higher accumulative capacities for Cr and Cd in terms of dry weight (DW) of the plant biomass in both belowground (16.9 mg Cr/kg DW, 189 μg Cd/kg DW) and aboveground (10.1 mg Cr/kg DW, 130 μg Cd/kg DW) parts.
Cycle Factors and Renewal Theory
Authors: Kahn Jeff , Lubetzky Eyal , Wormald Nicholas
Published: September 2015

For which values of k does a uniformly chosen 3‐regular graph G on n vertices typically contain n/k vertex‐disjoint k‐cycles (a k‐cycle factor)? To date, this has been answered for k = n and for k ≪  log n; the former, the Hamiltonicity problem, was finally answered in the affirmative by Robinson and Wormald in 1992, while the answer in the latter case is negative since with high probability (w.h.p.) most vertices do not lie on k‐cycles.

A major role in our study of this problem is played by renewal processes without replacement, where one wishes to estimate the probability that in a uniform permutation of a given set of positive integers, the partial sums hit a designated target integer. Using sharp tail estimates for these renewal processes, which may be of independent interest, we settle the cycle factor problem completely: the “threshold” for a k‐cycle factor in G as above is κ0 log2 n with . To be precise, G contains a k‐cycle factor w.h.p. if

urn:x-wiley:00103640:media:cpa21613:cpa21613-math-0002

and w.h.p. does not contain one if . Thus, for most values of n the threshold concentrates on the single integer K0(n). As a byproduct, we confirm the “comb conjecture,” an old problem concerning the embedding of certain spanning trees in the random graph (n,p).© 2015 Wiley Periodicals, Inc.
Safety, pharmacokinetics, and pharmacodynamics of PD 0348292, an oral, direct factor Xa inhibitor, after single and multiple dosings in healthy subjects
Authors: Xuan Dawei , McBride Scott , Wastall Philip , Porcari Anthony , DiCarlo Lorenzo , Boyd Rebecca A.
Published: September 2015

Objective: The objective of this study was to evaluate PD 0348292 safety, pharmacokinetics, and pharmacodynamics in healthy subjects.

Methods: Three phase 1 studies were conducted. Studies 1001 and 1021 were single ascending‐dose studies in healthy subjects randomized to oral PD 0348292 (2.5–150 and 0.1–2.5 mg, respectively) or placebo. Study 1003 was a multiple ascending‐dose study in which 3 cohorts of young subjects received multiple doses of PD 0348292 (5–30 mg) every 12 hours or placebo, and 1 cohort of elderly subjects received a single dose (5 mg) of PD 0348292 or placebo. Drug plasma concentrations were measured. The effects of PD 0348292 on thrombin generation and typical coagulation measures such as prothrombin time, and international normalized ratio were evaluated.

Results: Single doses of PD 0348292 were well tolerated. Minor bleeding‐related adverse events were observed following multiple doses of PD 0348292. PD 0348292 exposure increased less than proportionally at doses > 20 mg. Median peak concentrations occurred 3 to 4 hours following administration, and the mean terminal t1/2 value was approximately 10 hours. PD 0348292 demonstrated robust and concentration‐dependent inhibition of thrombin generation, and modest and dose‐related increases in typical coagulation measures.

Conclusions: The safety, pharmacokinetics, and pharmacodynamics of PD 0348292 were acceptable for future clinical development.
Charge Localization in the Lithium Iron Phosphate Li3Fe2(PO4)3 at High Voltages in Lithium‐Ion Batteries
Authors: Younesi Reza , Christiansen Ane , Loftager Simon , García‐Lastra Juan Maria , Vegge Tejs , Norby Poul , Holtappels Peter
Published: September 2015

Possible changes in the oxidation state of the oxygen ion in the lithium iron phosphate Li3Fe2(PO4)3 at high voltages in lithium‐ion (Li‐ion) batteries are studied using experimental and computational analysis. Results obtained from synchrotron‐based hard X‐ray photoelectron spectroscopy and density functional theory (DFT) show that the oxidation state of O2− ions is altered to higher oxidation states (Oδ−, δ<2) upon charging Li3Fe2(PO4)3 to 4.7 V.
Identification of polymorphism in ethylone hydrochloride: synthesis and characterization
Authors: Maheux Chad R. , Alarcon Idralyn Q. , Copeland Catherine R. , Cameron T. Stanley , Linden Anthony , Grossert J. Stuart
Published: September 2015

Ethylone, a synthetic cathinone with psychoactive properties, is a designer drug which has appeared on the recreational drug market in recent years. Since 2012, illicit shipments of ethylone hydrochloride have been intercepted with increasing frequency at the Canadian border. Analysis has revealed that ethylone hydrochloride exists as two distinct polymorphs. In addition, several minor impurities were detected in some seized exhibits. In this study, the two conformational polymorphs of ethylone hydrochloride have been synthesized and fully characterized by FTIR, FT‐Raman, powder XRD, GC‐MS, ESI‐MS/MS and NMR (13C CPMAS, 1H, 13C). The two polymorphs can be distinguished by vibrational spectroscopy, solid‐state nuclear magnetic resonance spectroscopy and X‐ray diffraction. The FTIR data are applied to the identification of both polymorphs of ethylone hydrochloride (mixed with methylone hydrochloride) in a laboratory submission labelled as 'Ocean Snow Ultra’. The data presented in this study will assist forensic scientists in the differentiation of the two ethylone hydrochloride polymorphs. This report, alongside our recent article on the single crystal X‐ray structure of a second polymorph of this synthetic cathinone, is the first to confirm polymorphism in ethylone hydrochloride. © 2015 Canada Border Services Agency. Drug Testing and Analysis published by John Wiley & Sons, Ltd. © 2015 Canada Border Services Agency. Drug Testing and Analysis published by John Wiley & Sons, Ltd.
Pulmonary Chlamydia muridarum challenge activates lung interstitial macrophages which correlate with IFN‐γ production and infection control in mice
Authors: Gracey Eric , Baglaenko Yuriy , Prayitno Nadia , Van Rooijen Nico , Akram Ali , Lin Aifeng , Chiu Basil , Inman Robert D.
Published: September 2015

Protective immunity to the pathogen Chlamydia is dependent on a robust IFN‐γ response generated by innate and adaptive lymphocytes. Here we assess the role of the macrophage in orchestrating a protective response in vivo to the murine pathogen, Chlamydia muridarum. During acute pulmonary and peritoneal infection, resident macrophages in both sites are infected with C. muridarum and adopt an inflammatory phenotype. In the lung, this activation is restricted to interstitial macrophages, which harbor higher levels of C. muridarum 16sRNA than alveolar macrophages. We examined innate and adaptive lymphocyte activation in the peritoneal cavity with macrophage depletion and with adoptive transfer of infected macrophages. These experiments demonstrate macrophage activation correlates with a protective IFN‐γ response and effective control of C. muridarum. These studies suggest that a quantitative or qualitative alteration in macrophages may play a key role in the development of Chlamydia‐associated diseases.
Seven‐Coordinate Luminophores: Brilliant Luminescence of Lanthanide Complexes with C3v Geometrical Structures
Authors: Yanagisawa Kei , Nakanishi Takayuki , Kitagawa Yuichi , Seki Tomohiro , Akama Tomoko , Kobayashi Masato , Taketsugu Tetsuya , Ito Hajime , Fushimi Koji , Hasegawa Yasuchika
Published: September 2015

Enhanced luminescence properties of mononuclear lanthanide complexes with asymmetric seven‐coordination structures are reported for the first time. The lanthanide complexes are composed of a lanthanide ion (EuIII or TbIII), three tetramethyl heptanedionato ligands, and one triphenylphosphine oxide ligand. The coordination geometries of the lanthanide complexes have been evaluated by using single‐crystal X‐ray analyses and shape‐measurement calculations. The complexes are categorized to be seven‐coordinate monocapped octahedral structures (point group C3v). The seven‐coordinate lanthanide complexes show high intrinsic emission quantum yields, extra‐large radiative rate constants, and unexpected small nonradiative rate constants. The brilliant luminescence properties have been elucidated in terms of the asymmetric coordination geometry and small vibrational quanta related to thermal relaxation.
On‐line preconcentration strategy for the simultaneous quantification of three local anesthetics in human urine using CZE
Authors: del Mar LópezGuerrero María , Hernández‐Mesa Maykel , Cruces‐Blanco Carmen , García‐Campaña Ana M.
Published: September 2015

The simultaneous determination of usually employed anesthetics (procaine, lidocaine, and bupivacaine) has been developed and validated using CE with ultraviolet detection at 212 nm. The separation of these three drugs has been achieved in less than 7 min, using a temperature of 25ºC and 25 kV, with a 150 mM citrate buffer (pH 2.5) as BGE. Field‐amplified sample injection (FASI) has been used for on‐line sample preconcentration. Ultrapure water and ACN 50/50 (v/v) mixture gave the greatest enhancement factor when it was employed as an injection solvent. Injection voltage and time were optimized, being 13 kV and 13 s, the optimum values, respectively. To avoid the possible irreproducibility associated with the electrokinetic injection, an internal standard such as tetracaine, was employed. The instrumental detection limits (LOD S/N = 3) for the compounds ranged between 2.6 and 7.0 μg L−1 and the quantitation limits (LOQ S/N = 10) between 37.8 and 55.9 μg L−1. The detection limits obtained in real human urine samples ranged between 55.2 and 83.6 μg L−1 and the quantitation limits between 196.0 and 276.0 μg L−1. The proposed method has demonstrated its applicability to the analysis of these local anesthetics in urine samples without any pretreatment, allowing the rapid determination of these target analytes.
Combined use of cyclofructans and an amino acid ester‐based ionic liquid for the enantioseparation of huperzine A and coumarin derivatives in CE
Authors: Stavrou Ioannis J. , Breitbach Zachary S. , Kapnissi‐Christodoulou Constantina P.
Published: September 2015

Cyclofructans (CFs) and their derivatives have recently been proven to be efficient chiral selectors (CSs) for the enantioseparation of several analytes in CE, HPLC, and GC. In this study, the chiral separation ability of a number of native and derivatized CFs was examined in CE. Particularly, six different CFs, with different derivatization groups and cavity sizes [native CF‐6 and CF‐7, isopropyl cyclofructan‐6 (IPCF‐6), IPCF‐7, sulfated cyclofructan‐6 (SCF‐6), and SCF‐7] were used as CSs for the enantioseparation of huperzine A, warfarin, and coumachlor. Almost all of the examined CFs, except from SCF‐6 & ‐7, demonstrated relatively low and sometimes no chiral separation ability for huperzine A. In an effort to improve both resolution and efficiency, the chiral ionic liquid D‐Alanine tert butyl ester lactate (D‐AlaC4Lac) was added into the BGE. In most of the cases, the combination of CF with D‐AlaC4Lac resulted in an improvement in peak efficiency and/or resolution. When CF‐6 was utilized with D‐AlaC4Lac, a resolution of 1.4 was obtained, while the use of IPCF‐6/D‐AlaC4Lac provided a baseline enantioseparation. Although the combination of SCF‐7 and 40 mM D‐AlaC4Lac did not affect resolution, it dramatically increased peak efficiency from 24 000 to 117 000. In the case of warfarin and coumachlor, IPCF‐6 and IPCF‐7 proved to be the most effective CSs. It is, therefore, concluded that the size of the cavity and the CF derivatization are the key parameters for the chiral separation capability. It is also clear from this study that D‐AlaC4Lac is necessary for improved peak efficiencies and resolutions.
Carbon pools in stream‐riparian corridors: legacy of disturbance along mountain streams of south‐eastern Wyoming
Authors: Ruffing Claire M. , Dwire Kathleen A. , Daniels Melinda D.
Published: September 2015

Streams and their accompanying riparian environments are intrinsic components of terrestrial carbon cycling. However, they have been understudied in terms of the magnitude of their storage components and the role of disturbance in determining carbon storage capacity. This study presents partial carbon budgets for stream‐riparian corridors along six study reaches in mountain headwater streams of southeast Wyoming to evaluate the impact of tie‐driving, a historic disturbance legacy, on contemporary carbon storage. Detailed measurements of biomass were collected for in‐stream components of carbon including fine and coarse particulate organic matter and in‐stream large wood. Biomass was also estimated for riparian components including standing trees (live and dead), regenerating conifers, shrubs and herbaceous vegetation, downed wood, litter, and duff (partially decayed litter). Biomass was converted to carbon for all components and differences in storage were compared between tie‐driven and non‐driven reaches. Carbon content in riparian soils (to approximately 20 cm) was also measured. Twice the amount of carbon was stored in the riparian areas relative to the streams; most carbon was stored in standing trees (live and dead). While overall carbon storage within the riparian areas and streams were similar between disturbance conditions, the amount of carbon stored in large in‐stream wood and downed wood on the floodplain was significantly higher in systems that were not tie‐driven. The results of this study indicate that legacies of tie‐driving influence carbon storage within the region, while also capturing baseline estimates of carbon storage in the wake of recent bark beetle infestations. Copyright © 2015 John Wiley & Sons, Ltd.
The extreme 2013/2014 winter storms: hydrodynamic forcing and coastal response along the southwest coast of England
Authors: Masselink Gerd , Scott Tim , Poate Tim , Russell Paul , Davidson Mark , Conley Daniel
Published: September 2015

The southwest coast of England was subjected to an unusually energetic sequence of Atlantic storms during the 2013/2014 winter, with the 8‐week period from mid‐December to mid‐February representing the most energetic period since at least 1953. A regional analysis of the hydrodynamic forcing and morphological response of these storms along the SW coast of England highlighted the importance of both storm‐ and site‐specific conditions.

The key factor that controls the Atlantic storm wave conditions along the south coast of southwest England is the storm track. Energetic inshore wave conditions along this coast require a relatively southward storm track which enables offshore waves to propagate up the English Channel relatively unimpeded. The timing of the storm in relation to the tidal stage is also important, and coastal impacts along the macro‐tidal southwest coast of England are maximised when the peak storm waves coincide with spring high tide. The role of storm surge is limited and rarely exceeds 1 m.

The geomorphic storm response along the southwest coast of England displayed considerable spatial variability; this is mainly attributed to the embayed nature of the coastline and the associated variability in coastal orientation. On west‐facing beaches typical of the north coast, the westerly Atlantic storm waves approached the coastline shore‐parallel, and the prevailing storm response was offshore sediment transport. Many of these north coast beaches experienced extensive beach and dune erosion, and some of the beaches were completely stripped of sediment, exposing a rocky shore platform. On the south coast, the westerly Atlantic storm waves refract and diffract to become southerly inshore storm waves and for the southeast‐facing beaches this results in large incident wave angles and strong eastward littoral drift. Many south coast beaches exhibited rotation, with the western part of the beaches eroding and the eastern part accreting. © 2015 The Authors.Earth Surface Processes and Landformspublished by John Wiley & Sons Ltd.
Preparation and stability of W/O/W emulsions containing sucrose as weighting agent
Authors: Zhang Jian , Reineccius Gary A.
Published: September 2015

The objective of present study was to evaluate the use of sucrose as a weighting agent in W/O/W emulsions. Placing sucrose in the internal water phase could increase the density of the oil droplet and provide natural weighing to the oil phase. A 60 wt% sucrose solution with or without gelatin served as inner aqueous phase (W). Orange oil terpenes (OT) or Miglyol 812 (MCT) were compared as oil phase (O). Different concentrations of polyglycerol polyricinoleate (PGPR) were evaluated as lipophilic emulsifier. Gum Arabic (GA), modified starch (MS), and/or Tween 20 were evaluated as hydrophilic emulsifiers. Mean droplet diameter (MDD) and encapsulation efficiency (EE) were measured with yellow #6 as a marker incorporated in inner aqueous phase. Nano‐sized W/O emulsions were formed with MDD as small as of 72 nm by using Microfluidization. Gelling the inner phase significantly increased droplet size of W/O emulsions. GA‐stabilized W/O/W emulsions showed highest dye retention (EE > 85%) and smallest MDD (0.75 to 4.5 µm), whereas MS and Tween 20 showed poor performance (EE <50%). Both concentrated and diluted W/O/W emulsions with MCT as oil phase stabilized by GA showed good stability in MDD, EE and turbidity during four weeks of storage at 23 °C. The results demonstrated the potential and challenges of creating stable beverage cloud applications based on W/O/W emulsions using sucrose as a natural weighting agent. Copyright © 2015 John Wiley & Sons, Ltd.
Brain volumetric changes and cognitive ageing during the eighth decade of life
Authors: Ritchie Stuart J. , Dickie David Alexander , Cox Simon R. , Valdes Hernandez Maria del C. , Corley Janie , Royle Natalie A. , Pattie Alison , Aribisala Benjamin S. , Redmond Paul , Muñoz Maniega Susana , Taylor Adele M. , Sibbett Ruth , Gow Alan J. , Starr John M. , Bastin Mark E. , Wardlaw Joanna M. , Deary Ian J.
Published: September 2015

Later‐life changes in brain tissue volumes—decreases in the volume of healthy grey and white matter and increases in the volume of white matter hyperintensities (WMH)—are strong candidates to explain some of the variation in ageing‐related cognitive decline. We assessed fluid intelligence, memory, processing speed, and brain volumes (from structural MRI) at mean age 73 years, and at mean age 76 in a narrow‐age sample of older individuals (n = 657 with brain volumetric data at the initial wave, n = 465 at follow‐up). We used latent variable modeling to extract error‐free cognitive levels and slopes. Initial levels of cognitive ability were predictive of subsequent brain tissue volume changes. Initial brain volumes were not predictive of subsequent cognitive changes. Brain volume changes, especially increases in WMH, were associated with declines in each of the cognitive abilities. All statistically significant results were modest in size (absolute r‐values ranged from 0.114 to 0.334). These results build a comprehensive picture of macrostructural brain volume changes and declines in important cognitive faculties during the eighth decade of life. Hum Brain Mapp 36:4910–4925, 2015. © 2015 The Authors. Human Brain Mapping Published by Wiley Periodicals, Inc
Transition Metal‐Free One‐Pot Protocol Toward Conjugated Arylbutadiynyl Sulfides
Authors: Zhang Yanqin , Xiao Jing , Dong Wanrong , Peng Zhihong , An Delie
Published: September 2015

An efficient strategy toward conjugated arylbuta‐1,3‐diynyl sulfides (Ar–C≡C–C≡C–SR) was herein reported. In the newly developed one‐pot, three‐steps protocol, the synthetically or materially significant arylbuta‐1,3‐diynyl sulfides were obtained from easily accessible 4‐hydrocarbylthio‐1‐arylbuta‐1,3‐diones, avoiding usage of expensive terminal aryl acetylenes as substrates or any transition metal complexes as catalysts. The gram‐scale experiment of the efficient methodology with acceptable yield afforded a good alternative of industrial interest.
Strategies and long‐term outcomes in the surgical management of tympanojugular paragangliomas
Authors: Prasad Sampath Chandra , Mimoune Hassen Ait , Khardaly Mohsen , Piazza Paolo , Russo Alessandra , Sanna Mario
Published: September 2015

Background

The purpose of this study was to share our review of surgical strategies and long‐term outcomes in the management of tympanojugular paragangliomas.

Methods

This was a retrospective study with a literature review. The records of 184 patients with 185 tympanojugular paragangliomas were analyzed for tumor class, surgical procedure, preoperative vascular management, and perioperative sequelae.

Results

Of class C1, C2, C3, and C4 tumors, we found 46 (24.9%), 95 (51.3%), 41 (22.2%), and 3 (1.6%), respectively. One hundred four (56.2%) tumors had intracranial extensions and 8 (4.3%) involved the vertebral artery. A single‐stage procedure was adopted in 158 (85.4%) tumors. The infratemporal fossa type A approach was used in all cases. In 17 patients (9.7%), an intra‐arterial stenting of the internal carotid artery was performed. Gross‐total tumor removal was achieved in 166 cases (89.7%) and 4 (2.4%) among them developed a recurrence.

Conclusion

A thorough understanding of skull base techniques and a logical decision‐making process in the management of tympanojugular paragangliomas can achieve a high rate of success in terms of recurrences and complications. © 2015 Wiley Periodicals, Inc. Head Neck 38: 871–885, 2016
Injected biodegradable polyurethane scaffolds support tissue infiltration and delay wound contraction in a porcine excisional model
Authors: Adolph Elizabeth J. , Guo Ruijing , Pollins Alonda C. , Zienkiewicz Katarzyna , Cardwell Nancy , Davidson Jeffrey M. , Guelcher Scott A. , Nanney Lillian B.
Published: September 2015

The filling of wound cavities with new tissue is a challenge. We previously reported on the physical properties and wound healing kinetics of prefabricated, gas‐blown polyurethane (PUR) scaffolds in rat and porcine excisional wounds. To address the capability of this material to fill complex wound cavities, this study examined the in vitro and in vivo reparative characteristics of injected PUR scaffolds employing a sucrose porogen. Using the porcine excisional wound model, we compared reparative outcomes to both preformed and injected scaffolds as well as untreated wounds at 9, 13, and 30 days after scaffold placement. Both injected and preformed scaffolds delayed wound contraction by 19% at 9 days and 12% at 13 days compared to nontreated wounds. This stenting effect proved transient since both formulations degraded by day 30. Both types of scaffolds significantly inhibited the undesirable alignment of collagen and fibroblasts through day 13. Injected scaffolds were highly compatible with sentinel cellular events of normal wound repair cell proliferation, apoptosis, and blood vessel density. The present study provides further evidence that either injected or preformed PUR scaffolds facilitate wound healing, support tissue infiltration and matrix production, delay wound contraction, and reduce scarring in a clinically relevant animal model, which underscores their potential utility as a void‐filling platform for large cutaneous defects. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1679–1690, 2016.
Histone Acetyltransferase GCN5 Regulates Osteogenic Differentiation of Mesenchymal Stem Cells by Inhibiting NF-κB
Authors: Zhang Ping , Liu Yunsong , Jin Chanyuan , Zhang Min , Tang Fuchou , Zhou Yongsheng
Published: September 2015

As the most well-studied histone acetyltransferase (HAT) in yeast and mammals, general control nonderepressible 5 (GCN5) was documented to play essential roles in various developmental processes. However, little is known about its role in osteogenic differentiation of mesenchymal stem cells (MSCs). Here, we detected the critical function of GCN5 in osteogenic commitment of MSCs. In this role, the HAT activity of GCN5 was not required. Mechanistically, GCN5 repressed nuclear factor kappa B (NF-κB)-dependent transcription and inhibited the NF-κB signaling pathway. The impaired osteogenic differentiation by GCN5 knockdown was blocked by inhibition of NF-κB. Most importantly, the expression of GCN5 was decreased significantly in the bone tissue sections of ovariectomized mice or aged mice. Collectively, these results may point to the GCN5-NF-κB pathway as a novel potential molecular target for stem cell mediated regenerative medicine and the treatment of metabolic bone diseases such as osteoporosis. © 2015 American Society for Bone and Mineral Research.
Large Deformation Mechanisms, Plasticity, and Failure of an Individual Collagen Fibril With Different Mineral Content
Authors: Depalle Baptiste , Qin Zhao , Shefelbine Sandra J , Buehler Markus J
Published: September 2015

Mineralized collagen fibrils are composed of tropocollagen molecules and mineral crystals derived from hydroxyapatite to form a composite material that combines optimal properties of both constituents and exhibits incredible strength and toughness. Their complex hierarchical structure allows collagen fibrils to sustain large deformation without breaking. In this study, we report a mesoscale model of a single mineralized collagen fibril using a bottom-up approach. By conserving the three-dimensional structure and the entanglement of the molecules, we were able to construct finite-size fibril models that allowed us to explore the deformation mechanisms which govern their mechanical behavior under large deformation. We investigated the tensile behavior of a single collagen fibril with various intrafibrillar mineral content and found that a mineralized collagen fibril can present up to five different deformation mechanisms to dissipate energy. These mechanisms include molecular uncoiling, molecular stretching, mineral/collagen sliding, molecular slippage, and crystal dissociation. By multiplying its sources of energy dissipation and deformation mechanisms, a collagen fibril can reach impressive strength and toughness. Adding mineral into the collagen fibril can increase its strength up to 10 times and its toughness up to 35 times. Combining crosslinks with mineral makes the fibril stiffer but more brittle. We also found that a mineralized fibril reaches its maximum toughness to density and strength to density ratios for a mineral density of around 30%. This result, in good agreement with experimental observations, attests that bone tissue is optimized mechanically to remain lightweight but maintain strength and toughness. © 2015 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research (ASBMR).
Enhanced Efficiency of Dye–sensitized Solar Cells Based on Bulk Synthesized TiO2 Nanorods Annealed at Different Temperatures
Authors: Sayahi Hani , Hamadanian Masood , Mohsenzadeh Farshid , Aghapoor Kioumars , Kiani Mohammad Ali
Published: September 2015

In this study, bulk TiO2 nanorods are synthesized by hydrothermal method in order to be used in the dye‐sensitized solar cells (DSSCs). These nanorods are annealed at different temperatures and deposited electrophoretically. The influence of post heat treatment has been thoroughly investigated on fabricated DSSCs using electrochemical impedance spectroscopy (EIS). The results have revealed that the diameter, size and density of the prepared bulk nanorods are function of annealing temperatures. Optimization of the prepared DSSCs has led to an improved efficiency (ca. 3.82%) under AM 1.5 simulated sunlight.
Condensation of Aryl Aldehydes, 2‐naphthol, and Thioacetamide Catalyzed by N‐halo Reagents in Neutral Media
Authors: Khazaei Ardeshir , Abbasi Fatemeh , Moosavi‐Zare Ahmad Reza , Khazaei Marzieh , Beyzavi M. Hassan
Published: September 2015

A new three‐component, highly efficient and solvent‐free approach for the synthesis of known and new 1‐thioamido‐alkyl‐2‐naphthol derivatives was investigated. This was achieved via a one‐pot condensation by reacting aryl aldehydes, 2‐naphthol, and thioacetamide in the presence of catalytic amount of 1,3,5‐trichloro‐1,3,5‐triazinane‐2,4,6‐trione (TCCA) and 1,3‐dichloro‐5,5‐dimethylhydantoin (DCDMH). Mechanistically, the in situ generation of Cl+ ion from TCCA and DCDMH is proposed to catalyse the reactions in neutral media. In the presented work, most of the products have been reported for the first time.
Synthesis of Novel and Thermally Stable Water Insoluble Coumarin‐based Azo Dyes via a Mild and Green Procedure
Authors: Kiani Mahtab , Karami Bahador
Published: September 2015

A series of novel azo coumarin dyes were synthesized by the diazotization of 7‐amino coumarins in the presence of catalytic amounts of tungstate sulfuric acid (TSA) followed by coupling with phenol derivatives. Tungstate sulfuric acid catalyzes this reaction at room temperature and short reaction time with high yields.
New Cu(I) Coordination Complexes Based on Tetrathiafulvalene Substituted Triazol‐pyridine Ligand: Synthesis, Properties and Theoretical Studies
Authors: Li Gao‐Nan , He Li‐Rong , Xia Dong , Li Lin , Cheng Wen‐Feng , Li Kai‐Xiu , Cui Feng , Niu Zhi‐Gang
Published: September 2015

Two Cu(I) complexes based on the thioethyl‐bridged triazol‐pyridine ligand with tetrathiafulvalene unit (TTF‐TzPy, L), [Cu(I)(Binap)(L)]BF4 (5, Binap=2,2’‐bis(diphenylphosphino)‐1,1’‐binaphthyl) and [Cu(I)(Xantphos)(L)]BF4 (6, Xantphos=9,9‐dimethyl‐4,5‐bis(diphenylphosphino)‐xanthene), have been synthesized. All new compounds are characterized by elemental analyses, 1H NMR and mass spectroscopies. The complex 5 has been determined by X‐ray structure analyses which shows that the central copper (I) ion assumes distorted tetrahedral geometry. The photophysical, computational and electrochemical properties of L and 5‐6 have been investigated. The most representative molecular orbital energy‐level diagrams and the spin‐allowed singletsinglet electronic transitions of the three compounds have been calculated with density functional theory (DFT) and time‐dependent DFT (TD‐DFT). The luminescence bands of Cu(I) complexes 5‐6 have been assigned as mixed intraligand and metal‐to‐ligand charge transfer 3(MLCT+π→π*) transitions through analysis of the photophysical properties and DFT calculations. The electrochemical studies reveal that 5‐6 undergo reversible TTF/TTF+•/TTF2+ redox processes and one irreversible Cu+→Cu2+ oxidation process.
Mechanical Loading Stimulates Expression of Collagen Cross‐Linking Associated Enzymes in Periodontal Ligament
Authors: Kaku Masaru , Rosales Rocabado Juan Marcelo , Kitami Megumi , Ida Takako , Akiba Yosuke , Yamauchi Mitsuo , Uoshima Katsumi
Published: September 2015

Type I collagen, a major extracellular component of the periodontal ligament (PDL), is post‐translationally modified by a series of specific enzymes. Among the collagen‐modifying enzymes, lysyl oxidase (LOX) is essential to initiate collagen cross‐linking and lysyl hydroxylases (LHs) to regulate the cross‐linking pathways that are important for tissue specific mechanical properties. The purpose of this study was to investigate the effects of mechanical loading on the expression of collagen‐modifying enzymes and subsequent tissue changes in PDL. Primary human PDL cells were subjected to mechanical loading in a 3D collagen gel, and gene expression and collagen component were analyzed. Wistar rats were subjected to excessive occlusal loading with or without intra‐peritoneal injection of a LOX inhibitor, β‐aminopropionitrile (BAPN). Upon mechanical loading, gene expression of LH2 and LOX was significantly elevated, while that of COL1A2 was not affected on hPDL‐derived cells. The mechanical loading also elevated formation of collagen α‐chain dimers in 3D culture. The numbers of LH2 and LOX positive cells in PDL were significantly increased in an excessive occlusal loading model. Notably, an increase of LH2‐positive cells was observed only at the bone‐side of PDL. Intensity of picrosirius red staining was increased by excessive occlusal loading, but significantly diminished by BAPN treatment. These results demonstrated that mechanical loading induced collagen maturation in PDL by up‐regulating collagen‐modifying enzymes and subsequent collagen cross‐linking which are important for PDL tissue maintenance. J. Cell. Physiol. 231: 926–933, 2016. © 2015 Wiley Periodicals, Inc.
Stress‐Induced Activation of Apoptosis Signal‐Regulating Kinase 1 Promotes Osteoarthritis
Authors: Zhang Qian‐Shi , Eaton Gregory J. , Diallo Carol , Freeman Theresa A.
Published: September 2015

Apoptosis signal‐regulated kinase 1 (ASK1) has been shown to affect a wide range of cellular processes including stress‐related responses, cytokine and growth factor signaling, cell cycle and cell death. Recently, we reported that lack of ASK1 slowed chondrocyte hypertrophy, terminal differentiation and apoptosis resulting in an increase in trabecular bone formation. Herein, we investigated the role of ASK1 in the pathogenesis of osteoarthritis (OA). Immunohistochemistry performed on articular cartilage samples from patients with OA showed ASK1 expression increased with OA severity. In vitro analysis of chondrocyte hypertrophy, maturation and ASK1 signaling in embryonic fibroblasts from ASK1 knockout (KO) and wild type (WT) mice was examined. Western analysis demonstrated an increase in ASK1 signaling commensurate with chondrogenic maturation during differentiation or in response to stress by the cytokines, tumor necrosis factor alpha or interleukin 1 beta in WT, but not in ASK1 KO embryonic fibroblasts. Surgically induced moderate or severe OA or OA due to natural aging in WT and ASK1 KO mice was assessed by microCT of subchondral bone, immunohistochemistry, histology, and OARSI scoring. Immunohistochemistry, microCT and OARSI scoring all indicated that the lack of ASK1 protected against OA joint degeneration, both in surgically induced OA and in aging mice. We propose that the ASK1 MAP kinase signaling cascade is an important regulator of chondrocyte terminal differentiation and inhibitors of this pathway could be useful for slowing chondrocyte maturation and cell death observed with OA progression. J. Cell. Physiol. 231: 944–953, 2016. © 2015 Wiley Periodicals, Inc.
Investigation of distillation systems using heavy or intermediate entrainers for separating toluene–methanol: process economics and control
Authors: Ma Jian , Li Weisong , Ni Chunli , Li Ye , Huang Shanyuan , Shen Changlin , Xu Chunjian
Published: September 2015

BACKGROUND

The separation of methanol–toluene by introducing aniline or triethylamine (Et3N) is investigated, with aniline and Et3N as heavy and intermediate entrainers, respectively. First, the conventional extractive distillation process with aniline as the extractive entrainer (HE) and the direct/indirect separating sequences using Et3N as intermediate entrainer (IE‐D/IE‐I) have been designed and optimized with rigorous simulations. Subsequently, the dynamic performances of these optimized processes are investigated with simple temperature control strategies. Finally, the steady‐state process economics and dynamic performances for these processes are facilitated.

RESULTS

The IE‐I process has a 7.26% total annual cost (TAC) saving compared with the HE process and the total energy cost of the IE‐I process is 18.79% lower than that of the HE process. As to dynamic performances, the maximum transient deviation of the methanol product purity in the IE‐I process is much smaller than that in the HE process when ±20% feed flow rate disturbances are introduced. And when −20% step toluene composition disturbance is introduced, the new steady‐state methanol product purity in the HE process is 99.5 mol% while that in the IE‐I process is 99.8%.

CONCLUSIONS

The numerical and graphic comparisons indicate that the IE‐I process possesses advantages over the HE process to some extent. The small advantages possessed by the IE‐I process are mainly those of the use of lower‐grade heat source, lower energy consumption and smaller dynamic deviations under feed disturbances. © 2015 Society of Chemical Industry
Preparation of Constrained Unnatural Aromatic Amino Acidsvia Unsaturated Diketopiperazine Intermediate
Authors: Mollica Adriano , Costante Roberto , Mirzaie Sako , Carradori Simone , Macedonio Giorgia , Stefanucci Azzurra , Novellino Ettore
Published: September 2015

Unnatural aromatic amino acids are useful tools in drug discovery, since their insertion in bioactive peptide sequences can change the side chains spatial orientation, the backbone conformation and above all, their bioactivity. In this communication, we propose a straightforward method to synthesize 2′,6′‐dimethyl‐tyrosine and 2′,6′‐dimehylphenyl‐alanine derivatives as handling building blocks for peptide synthesis via unsaturated diketopiperazine (DKP) intermediate.
Thermoseparating aqueous two‐phase systems: Recent trends and mechanisms
Authors: Leong Yoong Kit , Lan John Chi‐Wei , Loh Hwei‐San , Ling Tau Chuan , Ooi Chien Wei , Show Pau Loke
Published: September 2015

Having the benefits of being environmentally friendly, providing a mild environment for bioseparation, and scalability, aqueous two‐phase systems (ATPSs) have increasingly caught the attention of industry and researchers for their application in the isolation and recovery of bioproducts. The limitations of conventional ATPSs give rise to the development of temperature‐induced ATPSs that have distinctive thermoseparating properties and easy recyclability. This review starts with a brief introduction to thermoseparating ATPSs, including its history, unique characteristics and advantages, and lastly, key factors that influence partitioning. The underlying mechanism of temperature‐induced ATPSs is covered together with a summary of recent applications. Thermoseparating ATPSs have been proven as a solution to the demand for economically favorable and environmentally friendly industrial‐scale bioextraction and purification techniques.
Face masks and basketball: NCAA division I consumer trends and a review of over‐the‐counter face masks
Authors: Gandy Jessica R. , Fossett Lela , Wong Brian J.F.
Published: September 2015

Objectives/Hypothesis

This study aims to: 1) determine the current consumer trends of over‐the‐counter (OTC) and custom‐made face mask usage among National Collegiate Athletic Association (NCAA) Division I athletic programs; and 2) provide a literature review of OTC face guards and a classified database.

Study Design

Literature review and survey.

Methods

Consumer trends were obtained by contacting all 352 NCAA Division I programs. Athletic trainers present in the office when called answered the following questions: 1) “When an athlete breaks his or her nose, is a custom or generic face guard used?” and 2) “What brand is the generic face guard that is used?” Data was analyzed to determine trends among athletic programs. Also, a database of OTC devices available was generated using PubMed, Google, and manufacturer Web sites.

Results

Among the 352 NCAA Division I athletic programs, 254 programs participated in the survey (72% response rate). The majority preferred custom‐made guards (46%). Disadvantages included high cost and slow manufacture turnaround time. Only 20% of the programs strictly used generic brands. For the face mask database, 10 OTC products were identified and classified into four categories based on design, with pricing ranging between $35.99 and $69.95.

Conclusion

Only a handful of face masks exist for U.S. consumers, but none of them have been reviewed or classified by product design, sport application, price, and collegiate consumer use. This project details usage trends among NCAA Division I athletic programs and provides a list of available devices that can be purchased to protect the nose and face during sports.

Level of Evidence

NA. Laryngoscope, 126:1054–1060, 2016