bluuebunny/crossref_metadata_2025 huggingface dataset:
X‐Ray Scattering Reveals Ion‐Induced Microstructural Changes During Electrochemical Gating of Poly(3‐Hexylthiophene)
Authors: Thomas Elayne M. , Brady Michael A. , Nakayama Hidenori , Popere Bhooshan C. , Segalman Rachel A. , Chabinyc Michael L.
Published: September 2018

The heterogeneous microstructure of semicrystalline polymers complicates the relationship between their electrical conductivity and carrier concentration. Charge transport models typically describe conductivity with an assumption of uniform doping throughout the material. Here, the evolution in morphology and optoelectronic properties of poly(3‐hexylthiophene) (P3HT) is reported as a function of carrier concentration in an organic electrochemical transistor using a polymeric ionic liquid (PIL) as the gate insulator. Operando grazing incidence X‐ray scattering reveals that negatively charged ions from the dielectric first infiltrate the amorphous regions of the semiconductor, and then penetrate the crystalline regions at a critical carrier density of 4 × 1020 cm−3. Upon infiltration, the crystallites expand by 12% in the alkyl stacking direction and compress by 4% in the π–π stacking direction. The change in crystal structure of P3HT correlates with a sharply increasing effective carrier mobility. UV–visible spectroscopy reveals that holes induced in P3HT first reside in the crystalline regions of the polymer, which verifies that a charge carrier need not be in the same physical domain as its associated counterion. The dopant‐induced morphological changes of P3HT rationalize the dependence of mobility on carrier concentration, suggesting a phase transition of crystalline regions at high carrier concentration.
Oxygen Defect Modulated Titanium Niobium Oxide on Graphene Arrays: An Open‐Door for High‐Performance 1.4 V Symmetric Supercapacitor in Acidic Aqueous Electrolyte
Authors: Zhang Xiyue , Deng Shengjue , Zeng Yinxiang , Yu Minghao , Zhong Yu , Xia Xinhui , Tong Yexiang , Lu Xihong
Published: September 2018

Despite appealing supercapacitive properties, the acidic aqueous supercapacitors (SCs) are still suffering from low operating voltage (<1 V) leading to unsatisfactory energy densities. Herein, for the first time, it is reported that the oxygen defect modulated Ti2Nb10O29−x (TNOx) on interlinked graphene array (denoted as TNOxG) can achieve a wide potential window up to 1.8 V in 1 m H2SO4 electrolyte and deliver an extremely high capacitance up to 368.9 F g−1 at 0.5 A g−1. Accompanying the improved charge transfer efficiency and preferable H ion diffusion, the oxygen defects in TNOxG are capable of stimulating more pseudocapacitive behavior and simultaneously suppressing oxygen evolution reaction. Furthermore, a 1.4 V high voltage quasi‐solid‐state TNOxG‐based symmetric supercapacitor is demonstrated, yielding a maximum energy density of 0.58 mWh cm−3 at a power density of 0.57 W cm−3 and exceptionally excellent cycling durability. It is believed that this strategy of oxygen defect modulation to optimize reaction kinetics will lead to further improvements in the performance of high‐voltage aqueous SCs.
In Situ Synchrotron X‐Ray Diffraction Characterization of Corrosion Products of a Ti‐Based Metallic Glass for Implant Applications
Authors: Gostin Petre Flaviu , Addison Owen , Morrell Alexander P. , Zhang Yue , Cook Angus J. M. C. , Liens Alethea , Stoica Mihai , Ignatyev Konstantin , Street Steven R. , Wu Jing , Chiu Yu‐Lung , Davenport Alison J.
Published: September 2018

Ti‐based bulk metallic glasses are under consideration for implants due to their high yield strength and biocompatibility. In this work, in situ synchrotron X‐ray diffraction (XRD) is used to investigate the corrosion products formed from corrosion of Ti40Zr10Cu34Pd14Sn2 bulk metallic glass in artificial corrosion pits in physiological saline (NaCl). It is found that Pd nanoparticles form in the interior of the pits during electrochemical dissolution. At a low pit growth potential, the change in lattice parameter of the Pd nanoparticles is consistent with the formation of palladium hydride. In addition, a salt layer very close to the dissolving interface is found to contain CuCl, PdCl2, ZrOCl2∙8H2O, Cu, Cu2O, and several unidentified phases. The formation of Pd nanoparticles (16 ± 10 nm at 0.7 V vs Ag/AgCl) containing small amounts of the other alloying elements is confirmed by transmission electron microscopy. The addition of albumin and/or H2O2 does not significantly influence the nature of the corrosion products. When considering the biological compatibility of the alloy, the biological reactivity of the corrosion products identified should be explored.
Sustained and Bioresponsive Two‐Stage Delivery of Therapeutic miRNA via Polyplex Micelle‐Loaded Injectable Hydrogels for Inhibition of Intervertebral Disc Fibrosis
Authors: Feng Ganjun , Zha Zengshi , Huang Yong , Li Junjie , Wang Yuheng , Ke Wendong , Chen Hongying , Liu Limin , Song Yueming , Ge Zhishen
Published: September 2018

Intervertebral disc degeneration (IDD) is frequently caused by gradual pathological changes inside intervertebral discs (IVDs) and progressive fibrosis. MicroRNA‐29 (miR‐29) family possesses potent fibrosis suppression capability, but their application for treatment of chronic IDD is limited due to lack of suitable local delivery systems. In this report, given various overexpressed matrix metalloproteinases (MMPs) during IDD, injectable MMP‐degradable hydrogels encapsulating MMP‐responsive polyplex micelles are developed for sustained and bioresponsive delivery of miR‐29a into nucleus pulposus cells via a two‐stage process. Cationic block copolymers are designed to complex miR‐29a, and subsequently mixed with the poly(ethylene glycol) (PEG) gelation precursors and MMP‐cleavable peptide cross‐linkers for in situ formation of polyplex micelle‐encapsulated hydrogels in the diseased IVDs. In the presence of MMPs, the polyplex micelles are first released by MMP cleavage of the hydrogels, and subsequently, MMPs‐responsive detachment of PEG shells from polyplex micelles contributes to efficient cellular uptake and endosomal escape. MiR‐29a is demonstrated to effectively silence the expression of MMP‐2, inhibit the fibrosis process, and reverse IDD in animal models through blocking the β‐catenin translocation pathway from the cytoplasm to the nucleus. This two‐stage bioresponsive local miRNA delivery system represents a novel and promising strategy for the treatment of chronic IDD.
Additive Manufacturing: Applications and Directions in Photonics and Optoelectronics
Authors: Camposeo Andrea , Persano Luana , Farsari Maria , Pisignano Dario
Published: September 2018

The combination of materials with targeted optical properties and of complex, 3D architectures, which can be nowadays obtained by additive manufacturing, opens unprecedented opportunities for developing new integrated systems in photonics and optoelectronics. The recent progress in additive technologies for processing optical materials is here presented, with emphasis on accessible geometries, achievable spatial resolution, and requirements for printable optical materials. Relevant examples of photonic and optoelectronic devices fabricated by 3D printing are shown, which include light‐emitting diodes, lasers, waveguides, optical sensors, photonic crystals and metamaterials, and micro‐optical components. The potential of additive manufacturing applied to photonics and optoelectronics is enormous, and the field is still in its infancy. Future directions for research include the development of fully printable optical and architected materials, of effective and versatile platforms for multimaterial processing, and of high‐throughput 3D printing technologies that can concomitantly reach high resolution and large working volumes.
Modeling of fouling in cross‐flow microfiltration of suspensions
Authors: Weeranoppanant Nopphon , Amar Levy I. , Tong Evelyn , Faria Monica , Hill Michael I. , Leonard Edward F.
Published: September 2018

Cross‐flow filtration of fine suspensions through microsieves occurs in microprocessing. The interaction of particles with surfaces in microenvironments has been extensively studied, but predominantly in monolayers and not with an eye to microfiltration. Here, we introduce a microfiltration model that pertains to particles that might be seen as fine in a macroscopic environment, but are large enough to intrude significantly into the shear layer of a microchannel. Thus, particle accumulation upon the sieve couples the steady‐state filtrate flux and the suspension flow through the microchannel that feeds the sieve. We envision and create a stable, stationary multilayer of particles whose thickness is shear‐limited and we identify and verify the structure and parameters that limit steady filtration in this environment. At first, a packed bed of particles forms, growing into and regulated by the micro channel's shear flow. A critical shear stress is shown to determine the thickness of the bed, seen as a stationary and stable multilayer of particles through which filtration may occur. As the bed thickens, at the expense of channel area for suspension flow, surface shear stress increases until no further particle adherence is possible. We built a simple example using hard noninteracting polymer microspheres and conducted cross‐flow filtration experiments over Aquamarijn™ microsieves (uniform pore size of 0.8 μm). We observed a steady cake‐layer thickness and because of the simple geometry afforded by uniform spheres, we could approximate the force balance, cake resistance, and filtration rate from first principles. The good fit of our data to the proposed mechanism lays a firm basis for the semiquantitative analysis of the behavior of more complex suspensions. © 2018 American Institute of Chemical Engineers AIChE J, 65: 207–213, 2019
Natural Environments Near Schools: Potential Benefits for Socio‐Emotional and Behavioral Development in Early Childhood
Authors: Scott J. Taylor , Kilmer Ryan P. , Wang Chuang , Cook James R. , Haber Mason G.
Published: September 2018

Features of the natural environment such as tree canopy and green space have been found to promote health and well‐being; however, minimal research has investigated potential benefits of nature near schools for early childhood development. This study examined differences in teacher ratings of preschoolers’ socio‐emotional and behavioral functioning in relation to the presence of natural elements (e.g., trees, parks) near children's homes and schools. Students’ development of emotional and behavioral regulatory skills was the greatest when there were high levels of tree canopy either at home or school. Additionally, students developed greater independence and social skills when their schools were in neighborhoods with limited impervious surface (e.g., concrete); this trend was the most pronounced for students from neighborhoods low in impervious surface. Further, results suggested that associations with tree canopy may fluctuate seasonally (i.e., stronger relationships in the spring) and that the potential impact of school nature may depend on levels of home nature exposure. Although not yielding causal evidence regarding the impact of nature exposure or the effectiveness of greening interventions, findings suggest that school administrators and city planners could collaborate to maximize potential benefits of greening efforts near schools or within their catchment zones.
On‐the‐ground health and safety experiences of non‐union casino hotel workers: A focus‐group study stratified by four occupational groups
Authors: Romero Diana , Flandrick Kathleen , Kordosky Jason , Vossenas Pamela
Published: September 2018

Objectives

To understand the health‐ and safety‐related experiences of specific occupations among non‐union casino hotel employees to identify processes leading to worker health and safety risks.

Methods

Using purposive, criterion sampling, 61 workers participated in 13 recorded focus groups (FGs). A semi‐structured topic guide addressed work‐related health and safety impacts, workplace hazards, and management responses, among others. FG transcripts were analyzed following grounded theory methodology. Demographic and occupational health information was collected via survey.

Results

Codes (97) were collapsed into seven themes: activities/exposures negatively affecting health/safety; barriers to health/safety; injury/pain occurrences; coping mechanisms; job vulnerability; management policies/enforcement; lack of management concern for employees. From these themes emerged the Dynamic Theoretical Framework of Employee Health and Safety Risk.

Conclusions

“Management's lack of concern” creates a negative environment whereby employer‐controlled factors jeopardize employees’ health and safety. Interventions targeting management's lack of concern for employee health and safety could favorably change work‐based risks.
Phenolic Building Blocks for the Assembly of Functional Materials
Authors: Rahim Md. Arifur , Kristufek Samantha L. , Pan Shuaijun , Richardson Joseph J. , Caruso Frank
Published: September 2018

Phenolic materials have long been known for their use in inks, wood coatings, and leather tanning. However, there has recently been a renewed interest in engineering advanced materials from phenolic building blocks. The intrinsic properties of phenolic compounds, such as metal chelation, hydrogen bonding, pH responsiveness, redox potentials, radical scavenging, polymerization, and light absorbance, have made them a distinct class of structural motifs for the synthesis of functional materials. Materials prepared from phenolic compounds often retain many of these useful properties with synergistic effects in applications ranging from catalysis to biomedicine. This Review provides an overview of the diverse functional materials that can be prepared from natural and synthetic phenolic building blocks, as well as their applications.
Promoting Terminal Olefin Metathesis with a Supported Cationic Molybdenum Imido Alkylidene N‐Heterocyclic Carbene Catalyst
Authors: Pucino Margherita , Inoue Mariko , Gordon Christopher P. , Schowner Roman , Stöhr Laura , Sen Suman , Hegedüs Csaba , Robé Emmanuel , Tóth Flórián , Buchmeiser Michael R. , Copéret Christophe
Published: September 2018

Silica‐supported cationic Mo‐imido alkylidene N‐heterocyclic carbene catalysts, prepared by surface organometallic chemistry, display contrasting olefin metathesis activity for terminal and internal olefins. The high metathesis activity towards terminal alkenes is attributed to the strong σ‐donating property of the NHC ancillary ligand, which disfavors the formation of the parent square‐planar metallacyclobutane, an off‐cycle reaction intermediate resulting from the reaction with ethylene, one of the metathesis products. This tailored ligand environment also allowed the first trigonal bipyramidal (TBP) metallacyclobutane reaction intermediate for supported Mo metathesis catalysts to be identified.
Bayesian modeling and forecasting of Value‐at‐Risk via threshold realized volatility
Authors: Chen Cathy W.S. , Watanabe Toshiaki
Published: September 2018

This study proposes a threshold realized generalized autoregressive conditional heteroscedastic (GARCH) model that jointly models daily returns and realized volatility, thereby taking into account the bias and asymmetry of realized volatility. We incorporate this threshold realized GARCH model with skew Student‐t innovations as the observation equation, view this model as a sharp transition model, and treat the realized volatility as a proxy for volatility under this nonlinear structure. Through the Bayesian Markov chain Monte Carlo method, the model can jointly estimate the parameters in the return equation, the volatility equation, and the measurement equation. As an illustration, we conduct a simulation study and apply the proposed method to the US and Japan stock markets. Based on quantile forecasting and volatility estimation, we find that the threshold heteroskedastic framework with realized volatility successfully models the asymmetric dynamic structure. We also investigate the predictive ability of volatility by comparing the proposed model with the traditional GARCH model as well as some popular asymmetric GARCH and realized GARCH models. This threshold realized GARCH model with skew Student‐t innovations outperforms the competing risk models in out‐of‐sample volatility and Value‐at‐Risk forecasting.
Anforderungen und Konzept für eine automatisierte Zustandserfassung von Bauwerken mittels Bilderfassung und ‐auswertung
Authors: Reinhardt Markus , Gebauer Daniel , Marx Steffen
Published: September 2018

Dieser Bericht stellt die Forschungsausrichtung des Eisenbahn‐Bundesamts bzgl. der Digitalisierung im Bauwesen dar und stellt das in diesem Rahmen durchgeführte erste Projekt kurz vor. Prognoseverfahren zur Abschätzung des Zustands und zur Planung von Instandhaltungsmaßnahmen werden in weiten Bereichen der stationären Industrie bereits eingesetzt. Diese Technologie, das Predictive Maintenance (PM), auch für das Bauwesen zu erschließen, ist eines der zentralen Themen der aktuellen Forschung und logische Folge der konsequenten Einführung und Nutzung digitaler Technologien. Neben der Erfassung und Lokalisation der Daten sind die Analyse, die Bewertung und die Ableitung konkreter Maßnahmen die zu untersuchenden Fragestellungen. Die Leibniz Universität Hannover (LUH) hat im Auftrag des Eisenbahn‐Bundesamts (EBA) im Rahmen eines Projekts die Grundanforderungen zur Erkennung und Klassifizierung von Schäden an Stahlbetonbrücken anhand optischer Kriterien untersucht.
Grundlagen – Einsatzgebiete – rechtliche Rahmenbedingungen für Drohnensysteme
Authors: Holst Ralph
Published: September 2018

Drohnen bzw. UAV/UAS (unmanned aerial vehicles/systems) sind sehr stark weiterentwickelt worden und für unterschiedlichste Einsätze praxistauglich. Sie sind auch im zivilen Bereich angekommen und bieten zusammen mit passender Erfassungs/‐Aufnahmetechnik ein großes Einsatzpotenzial auch im Bereich der Verkehrsinfrastrukturen. Es wird für Eigentümer von Infrastrukturen immer wichtiger, umfassend, schnell und zeitnah über Art, Umfang und Zustand von Anlagen informiert zu sein. Dafür können UAS in Kombination mit bekannten und bewährten Verfahren einen wichtigen Beitrag leisten. In diesem Beitrag werden, bezogen auf den Einsatz im Infrastrukturbereich, die unterschiedlichen Systeme und Einsatzmöglichkeiten kurz vorgestellt. Dann wird der sehr wichtige Bereich der rechtlichen Regelungen in Deutschland, benachbarten und weiteren Ländern beleuchtet. Denn die große Einsatzfähigkeit führt auch zu missbräuchlichen bzw. gefährlichen Einsätzen. Hier gilt es Regelungen zu schaffen bzw. anzupassen, die einen Einsatz sowohl im professionellen wie privaten Bereich ermöglichen und trotzdem den Schutz von Anlagen und Dritter (Privatsphäre bzw. körperliche Unversehrtheit) gewährleisten. Im Ausblick werden kurz wichtige Aspekte zukünftiger Entwicklungen dargestellt.
Move to Nano‐Arthrology: Targeted Stimuli‐Responsive Nanomedicines Combat Adaptive Treatment Tolerance (ATT) of Rheumatoid Arthritis
Authors: Liu Lu , Guo Weisheng , Liang Xing‐Jie
Published: September 2018

Rheumatoid arthritis (RA) is one of the most popular chronic autoimmune diseases characterized with persistent synovial inflammation and bone destruction. Although considerable developments have been gained in clinical treatment of RA, the major drawback to RA therapy stems from the adaptive treatment tolerance (ATT) following the long‐term drug use, which causes compromised efficacy, sustained drug dose increase, and severe adverse events. To address these challenges, it is of great significance to put forward innovative therapeutic approaches for RA treatment. Nowadays, developments of nanotechnology‐based nanomedicines (NMs) for RA are in progress. Multifunctional NMs with targeted stimuli‐responsive features have been one of the central concepts in designing more accessible formulations for efficient RA treatment. These NMs are able to postpone RA progression effectively, because of their delivery and on‐demand release of medicaments at targeted sites in response to external or internal stimuli related to the RA pathophysiology without obvious adverse side‐effects on the normal tissues. Therefore, NMs have gained interest from pre‐clinical research scientists as well as clinical doctors worldwide. Herein, the authors highlight the recent attempts of targeted stimuli‐responsive NMs for RA therapy in the last 5 years. The described progresses may pave the way to novel and highly effective RA NMs.
Thirty‐day recurrence after ischemic stroke or TIA
Authors: Khanevski Andrej Netland , Bjerkreim Anna Therese , Novotny Vojtech , Næss Halvor , Thomassen Lars , Logallo Nicola , Kvistad Christopher E.
Published: September 2018

Background

Incidence of recurrent stroke is highest within 30 days after the initial ischemic stroke (IS) or TIA, but knowledge about early recurrence is lacking. We aimed to identify etiological groups with highest risk of early recurrence and assess how the TOAST classification identified index stroke etiology.

Methods

Medical records of 1874 IS and TIA patients in the Bergen NORSTROKE registry were retrospectively reviewed for identification of recurrent IS or TIA within 30 days after index IS or TIA. Stroke etiology was determined by review of electronical medical journals. Logistic regression was used to calculate odds ratios (OR) for 30‐day recurrence.

Results

Thirty‐three patients (1.8%) were readmitted with recurrent IS or TIA within 30 days after index stroke. By using TOAST, 12 patients were initially classified with stroke of unknown etiology (SUE). Etiologies behind recurrent IS or TIA were after the recurrent episode identified as extracranial large artery atherosclerosis (LAA) in 14 patients (42.4%), intracranial arterial pathology in seven patients (21.2%), active malignancy in six patients (18.2%), and cardio embolism in four patients (12.1%). Small vessel occlusion and SUE were the causes in one patient each. Logistic regression showed that patients with stroke of other determined etiology (SOE) and LAA had increased risk of 30‐day recurrence (OR = 9.72, 95% CI 1.84–51.3, p < 0.01 and OR = 4.36, 95% CI 2.01–9.47, p < 0.01, respectively).

Conclusion

Patients with LAA and SOE had increased risk of recurrent IS or TIA within 30 days. TOAST was inadequate at identifying exact etiologies behind recurrent stroke at index event.
Engineering, on‐demand manufacturing, and scaling‐up of polymeric nanocapsules
Authors: Crecente‐Campo José , Alonso María José
Published: September 2018

Polymeric nanocapsules are versatile delivery systems with the capacity to load lipophilic drugs in their oily nucleus and hydrophilic drugs in their polymeric shell. The objective of this work was to expand the technological possibilities to prepare customized nanocapsules. First, we adapted the solvent displacement technique to modulate the particle size of the resulting nanocapsules in the 50–500 nm range. We also produced nanosystems with a shell made of one or multiple polymer layers i.e. chitosan, dextran sulphate, hyaluronate, chondroitin sulphate, and alginate. In addition, we identified the conditions to translate the process into a miniaturized high‐throughput tailor‐made fabrication that enables massive screening of formulations. Finally, the production of the nanocapsules was scaled‐up both in a batch production, and also using microfluidics. The versatility of the properties of these nanocapsules and their fabrication technologies is expected to propel their advance from bench to clinic.
Educational interactive hydraulic and geometric design of a spillway using labview and geometrical modeling
Authors: Allawi Faridoun A. M.
Published: September 2018

Based on theories of geometrical modeling, an educational interactive LabVIEW program is designed to enable hydraulic engineers to design 2D and 3D hydraulic structures like spillways and energy dissipater basins. The parametric definitions of curves and surfaces in geometrical modelling are based on matrices which are found to be useful when used for the geometrical design of hydraulic structures. The LabVIEW matrices, through the use of the build array functions, the build matrix functions, and the 3D parametric surface functions are used for achieving the purpose of designing this software. The LabVIEW matrices enable the designer to change the hydraulic design parameters very easily and quickly to obtain more reliable and more accurate 2D and 3D designs. With LabVIEW it is not required to write a program instead a block diagram is necessary to be designed for achieving a certain required engineering task which is much simpler than writing a program especially when the task is complicated. When used for class room demonstration, the environment of the program and its visual artifacts enabled the students to enhance their understandings regarding the design of spillway and energy dissipater structures. This research paper spots the light on the major parts of this interactive software for the hydraulic designs of spillways and energy dissipation basins.
USP14 as a novel prognostic marker promotes cisplatin resistance via Akt/ERK signaling pathways in gastric cancer
Authors: Fu Ying , Ma Gang , Liu Guolong , Li Bin , Li Hui , Hao Xishan , Liu Liren
Published: September 2018

Gastric cancer (GC) ranks the third leading cause of global cancer mortality. Despite recent progress in surgery combined with chemotherapy, the outcomes of GC patients have barely improved. Therefore, better understanding of the molecular mechanisms involved in chemoresistance of GC may help develop novel strategies to treat this deadly disease. Previous evidence has shown aberrant expressions of USP14 in multiple malignancies, suggesting an important role of USP14 in tumorigenesis. However, its role in modulating chemoresistance in GC still remains elusive. In this study, we observed that USP14 levels were significantly increased in GC tissues compared to the paired normal tissues. Multivariate analysis demonstrated that USP14 level was an independent prognostic factor for DFS in GC patients. Silencing of USP14 promoted proteasomal degradation of p‐ERK (T202/Y204) and p‐Akt (T308/S473), thus inactivating Akt and ERK signaling pathways. Interestingly, silencing of USP14 alone was not sufficient to cause overt effects on cell growth, proliferation, and apoptosis, while resulting in significant apoptosis in the presence of cisplatin in GC cells. Thus, knockdown of USP14 sensitized GC cells to cisplatin by triggering cisplatin‐induced apoptosis via impeding Akt and ERK signaling pathways. These results revealed a novel role of USP14 in modulating chemosensitivity of GC cells, suggesting USP14 may serve as not only a prognostic marker, but also a potential therapeutic target for GC patients.
Malignant transformation of a spiradenoma with blaschkoïd pattern
Authors: Salim Salma , Bounniyt Hafsae , El Amraoui Mohammed , Benzekri Asmae , Senouci Karima , Hassam Badredine
Published: September 2018

Key Clinical Message

Eccrine spiradenoma is a benign and rare adnexal tumor originating from cutaneous eccrine sweat glands. It usually presents as a solitary lesion. It can have different presentations, including a blaschkoid arrangement which is rare. Malignant transformation is possible and usually occurs after a long period of latency in multifocal types.
A serious case of primary Raynaud's phenomenon in an infant
Authors: Kobayashi Masaru , Takano Ken‐ichi , Kamizono Junji , Ichikawa Kotaro
Published: September 2018

Key Clinical Message

We present a case of severe Raynaud phenomenon (RP) in an infant. The current strategy of RP treatment is incomplete; excluding secondary Raynaud phenomenon is vital as well. This case aims to help those with similar symptoms in the future by gathering data on cases.
Nickel‐Nanoparticles on Doped Graphene: A Highly Active Electrocatalyst for Alcohol and Carbohydrate Electrooxidation for Energy Production
Authors: Shabnam Luba , Faisal Shaikh N. , Roy Anup K. , Gomes Vincent G.
Published: September 2018

Nickel nanoparticles supported on nitrogen doped graphene (Ni−NGr) as highly efficient electrocatalyst were synthesized via controlled thermal annealing using a mixture of graphene oxide, nickel nitrate and uric acid. The synthesized Ni−NGr catalyst presented excellent electrocatalytic performance for ethanol, glucose and glycerol oxidation, stemming from the synergistic effects of nickel and N‐graphene. The electrocatalytic activity was enhanced by the high surface area and nitrogen‐based active sites of pyridinic and graphitic N in doped graphene. These N‐moieties enhanced the accessibility of active sites while preventing agglomeration of nickel nanoparticles on the doped graphene surface. The hybrid electrocatalyst performances were significantly improved and are suited for electrooxidation application in fuel cells.
Electrochemical Conversion of CO2 to HCOOH at Tin Cathode: Development of a Theoretical Model and Comparison with Experimental Results
Authors: Proietto Federica , Galia Alessandro , Scialdone Onofrio
Published: September 2018

The electrochemical reduction of pressurized carbon dioxide at tin cathode is considered a very promising process for the production of formic acid. Here, the process was studied in an undivided cell with the aim of developing a simple theoretical model. First, a large series of polarization and electrolyses was performed in order to evaluate the kinetic of the process. According to the literature, experimental results can be described by a simple reaction mechanism, which involves the following key stages: (i) mass transfer of CO2 to the cathode; (i) its adsorption described by a Langmuir equation; (iii) the reduction of adsorbed CO2. A simple model was developed based on the cathodic conversion of pressurized CO2 to HCOOH and on its anodic oxidation. The theoretical model was in a good agreement with experimental results collected in this work and in previous ones and well described the effect of several operative parameters, including current density, pressure and kind of reactor.
Entrapment of THF‐Stabilized Iridacyclic IrIII Silylenes from Double H−Si Bond Activation and H2 Elimination
Authors: Binh Dang Ho , Hamdaoui Mustapha , Fischer‐Krauser Diane , Karmazin Lydia , Bailly Corinne , Djukic Jean‐Pierre
Published: September 2018

The reaction of H3SiR (R=Ph, nBu) with cationic η5‐C5Me5‐ (Cp*) and benzo[h]quinolinyl‐based iridacycle [1 b]+ gives rise to new [(IrH)→SiRH2]+ adducts. In the presence of THF these adducts readily undergo elimination of H2 gas at subambient temperature to form THF‐stabilized metallacyclic IrIII silylene complexes, which were characterized in situ by NMR spectroscopy, trapped in minute amounts by reactive crystallization, and structurally characterized by XRD. Theoretical investigations (static DFT‐D reaction‐energy profiling, ETS‐NOCV) support the promoting role of THF in the H2 elimination step and the consolidation of the Ir‐to‐Si interaction in the spontaneous (ΔG<0) formation of Ir silylenes in the presence of THF. Mechanistic insights indicate that the Ir silylene species arising from the [1 b]+/phenylsilane system are relevant catalytic species in the hydrodefluorination of fluoroalkanes.
Experimental methods in chemical engineering: Preface
Authors: Patience Gregory S.
Published: September 2018

Chemical engineering research encompasses a plethora of subjects ranging from nanoscale to climate change, from medicine to hazardous waste management, and from electronics and photonics to process intensification, manufacturing, and modelling. The 2017 AIChE meeting included 8000 oral presentations and posters with all these diverse topics. Here we identify experimental methods and instrumentation that straddle these subjects based on Can. J. Chem. Eng. articles published from 2016–2017. Temperature, pH, pressure, and flow rate are the physical properties most researchers report. We identified over 50 experimental techniques, reactor types, and modelling methodologies and show that articles with an experimental focus are more strongly linked than those that concentrate on hydrodynamic modelling and numerical simulation. Spectroscopy dominates instrumental techniques to characterize solids and catalyst properties and we classify 36 instruments according to what property they measure and the scale, nature of the phase, composition, and morphology. A bibliometric analysis grouped the physicochemical properties into three major research clusters centered around solid properties, liquid phase properties, and gas phase and aqueous phase properties. Articles in this special series describe the basic principles of one experimental method or instrument that appears frequently in the journal. Together with a short background, the articles highlight fields of application, assess the sources of error, detection thresholds, and uncertainty. This series provides chemical engineers with a concise, accessible reference guide to help identify and choose appropriate experimental techniques and instruments.
Injectable Hydrogel of Vitamin B9 for the Controlled Release of Both Hydrophilic and Hydrophobic Anticancer Drugs
Authors: Panja Aditi , Das Sujoy , Chakraborty Atanu , Chakraborty Priyadarshi , Pal Suman , Nandi Arun K.
Published: September 2018

Folic acid (FA), vitamin B9, is a good receptor of drugs triggering cellular uptake via endocytosis. FA is sparingly soluble in water. Herein, a new approach for the formation of FA hydrogel by the hydrolysis of glucono‐δ‐lactone in PBS buffer under physiological conditions has been reported. The gel has a fibrillar network morphology attributable to intermolecular H‐bonding and π‐stacking interactions. The thixotropic property of the gel is used for the encapsulation of both hydrophilic [doxorubicin (DOX)] and hydrophobic [camptothecin (CPT)] drugs. The loading of DOX and CPT into the gel is attributed to the H‐bonding interaction between FA and drugs. The release of DOX is sustainable at pH 4 and 7, and the Peppas model indicates that at pH 7 the diffusion of the drug is Fickian but it is non‐Fickian at pH 4. The release of CPT is monitored by fluorescence spectroscopy, which also corroborates the combined release of both drugs. The metylthiazolyldiphenyltetrazolium bromide assay of FA hydrogel demonstrates nontoxic behavior and that the cytotoxicity of the DOX‐loaded FA hydrogel is higher than that of pure DOX, with a minimal effect on normal cells.
Alternative data processing techniques for serial NMR experiments
Authors: Shchukina Alexandra , Urbańczyk Mateusz , Kasprzak Paweł , Kazimierczuk Krzysztof
Published: September 2018

NMR measurements are often performed in a serial manner, that is, the acquisition of an FID signal is repeated under various conditions, either controlled (as temperature or pH changes) or uncontrolled (as reaction progress). The traditional approach to process “serial” data is to perform the Fourier transform of each FID in a series. However, it suffers from several problems, in particular, from the need to sample full Nyquist grid and reach a sufficient signal‐to‐noise ratio in each separate spectrum. The problems become particularly cumbersome in the case of multidimensional signals, where sampling is costly and sensitivity is an issue. Over the years, several methods of alternative, “joint” processing of FID series have been proposed. In this paper, we discuss the principles of some of them: Accordion Spectroscopy, Multidimensional Decomposition, Radon transform, a combination of Compressed Sensing and the Laplace transform. According to our knowledge, this is the first review on serial NMR data processing approaches. The reader is provided with MATLAB scripts allowing to perform simulations and processing using these algorithms.
Covariance nuclear magnetic resonance methods for obtaining protein assignments and novel correlations
Authors: Kancherla Aswani K. , Frueh Dominique P.
Published: September 2018

Protein nuclear magnetic resonance (NMR) assignment can be a tedious and error‐prone process, and it is often a limiting factor in biomolecular NMR studies. Challenges are exacerbated in larger proteins, disordered proteins, and often alpha‐helical proteins, owing to an increase in spectral complexity and frequency degeneracies. Here, several multidimensional spectra must be inspected and compared in an iterative manner before resonances can be assigned with confidence. Over the last 2 decades, covariance NMR has evolved to become applicable to protein multidimensional spectra. The method, previously used to generate new correlations from spectra of small organic molecules, can now be used to recast assignment procedures as mathematical operations on NMR spectra. These operations result in multidimensional correlation maps combining all information from input spectra and providing direct correlations between moieties that would otherwise be compared indirectly through reporter nuclei. Thus, resonances of sequential residues can be identified and side‐chain signals can be assigned by visual inspection of 4D arrays. This review highlights advances in covariance NMR that permitted to generate reliable 4D arrays and describes how these arrays can be obtained from conventional NMR spectra.
Triel‐Bonded Complexes between TrR3 (Tr=B, Al, Ga; R=H, F, Cl, Br, CH3) and Pyrazine
Authors: Michalczyk Mariusz , Zierkiewicz Wiktor , Scheiner Steve
Published: September 2018

Complexes between TrR3 (Tr=B, Al, Ga; R=H, F, Cl, Br, CH3) molecules and pyrazine have been characterized at the MP2 and CCSD(T) levels of theory. The adducts can be grouped according to the type of molecular arrangement. The first situation places the Tr atom in the plane of the pyrazine ring and contains a triel bond to the N lone pair. For the boron complexes the orbital interaction energy is almost equal to the electrostatic component, while the former is only half the latter for Tr=Al and Ga. The two monomers are stacked above one another in the second configuration, which depends to a greater degree upon orbital interaction and dispersion. The former complexes are more strongly bonded than the latter. Interaction energies (Eint) for the stronger complexes vary between −50 and −20 kcal/mol for BBr3 and Ga(CH3)3 paired respectively with pyrazine. Eint is much smaller for the stacked configurations, ranging from −8 for GaF3 to −1.4 kcal/mol for BF3. The value of the maximum of the electrostatic potential correlates poorly with Eint, attributed in part to monomer distortions upon complexation.
Probing Polymer Chain Conformation and Fibril Formation of Peptide Conjugates
Authors: Evgrafova Zhanna , Voigt Bruno , Baumann Monika , Stephani Madlen , Binder Wolfgang H. , Balbach Jochen
Published: September 2018

Covalent conjugates between a synthetic polymer and a peptide hormone were used to probe the molecular extension of these macromolecules and how the polymer modifies the fibril formation of the hormone. NMR spectroscopy of 15N labeled parathyroid hormone (PTH) was employed to visualize the conformation of the conjugated synthetic polymer, triggered by small temperature changes via its lower critical solution temperature. A shroud‐like polymer conformation dominated the molecular architecture of the conjugated chimeras. PTH readily forms amyloid fibrils, which is probably the physiological storage form of the hormone. The polyacrylate based polymers stimulated the nucleation processes of the peptide.
Bone Marrow Chimeras to Study Neuroinflammation
Authors: Laflamme Nathalie , Préfontaine Paul , Lampron Antoine , Rivest Serge
Published: September 2018

Bone marrow transplantation is the standard of care for a host of diseases such as leukemia and multiple myeloma, as well as genetically inherited metabolic diseases affecting the central nervous system. In mouse models, bone marrow transplantation has proven a valuable tool for understanding the hematopoietic system and the homing of hematopoietic cells to their target organs. Many techniques have been developed to create chimeric mice, animals with a hematopoietic system derived from a genetic background that differs from the rest of the body. Current genetic tools allow for virtually limitless possibilities in the choice of donor mice. This protocol describes methods of bone marrow transplantation in mouse models for studies of the brain under basal and pathological conditions. Specific points to be addressed include the preparation of recipient mice by irradiation or chemotherapy; the choice, isolation, and injection of donor cells; and analytical methods such as fluorescence‐activated cell sorting and immunostaining. © 2018 by John Wiley & Sons, Inc.
Action‐selection perseveration in young children: Advances of a dynamic model
Authors: Cox Ralf F. A. , Smitsman Ad W.
Published: September 2018

This study presents an empirical test and dynamic model of perseverative limb selection in children of 14‐, 24‐, and 36‐months old (N = 66 in total). In the experiment, children repeatedly grasped a spoon with a single hand. In two separate conditions, the spoon was presented either four times on their right side or four times on their left side. In both conditions, following this training, the spoon was presented on midline for two more trials. This setup enabled us to determine whether children's limb selection was influenced by their prior choices in the task (i.e., perseveration). Individual children's handedness was determined in a third condition consisting of nine object presentations (laterally or on midline). A dynamic model for limb selection is presented combining external input, motor memory, and preferences. The model was used to simulate the experiment and reproduced the results, including the age‐related changes.
Transferability of biotic interactions: Temporal consistency of arctic plant–rodent relationships is poor
Authors: Soininen Eeva M. , Henden John‐Andre , Ravolainen Virve T. , Yoccoz Nigel G. , Bråthen Kari Anne , Killengreen Siw T. , Ims Rolf A.
Published: September 2018

Variability in biotic interaction strength is an integral part of food web functioning. However, the consequences of the spatial and temporal variability of biotic interactions are poorly known, in particular for predicting species abundance and distribution. The amplitude of rodent population cycles (i.e., peak‐phase abundances) has been hypothesized to be determined by vegetation properties in tundra ecosystems. We assessed the spatial and temporal predictability of food and shelter plants effects on peak‐phase small rodent abundance during two consecutive rodent population peaks. Rodent abundance was related to both food and shelter biomass during the first peak, and spatial transferability was mostly good. Yet, the temporal transferability of our models to the next population peak was poorer. Plant–rodent interactions are thus temporally variable and likely more complex than simple one‐directional (bottom‐up) relationships or variably overruled by other biotic interactions and abiotic factors. We propose that parametrizing a more complete set of functional links within food webs across abiotic and biotic contexts would improve transferability of biotic interaction models. Such attempts are currently constrained by the lack of data with replicated estimates of key players in food webs. Enhanced collaboration between researchers whose main research interests lay in different parts of the food web could ameliorate this.
Detection of bed position for automation of patient‐monitoring function
Authors: Inoue Madoka , Yasui Toshiyuki , Taguchi Ryo , Umezaki Taizo
Published: September 2018

In hospitals, in order to prevent a patient from falling and fall accidents, there is an increasing demand to detect a lifting movement and a leaving‐off movement of a patient with a camera installed in a hospital room. As a measure for efficiently detecting these operations, a process of specifying a bed position which is an occurrence position of an action is effective. We propose a method to detect bed position from image of monocular camera, using image features and framework of machine learning. By generating a viewpoint conversion image for an input image, a uniform bed shape is acquired even for images at different camera positions. Evaluation was made with 2160 still images and 3888 scene moving images to confirm the usefulness of the method.
Water primrose invasion changes successional pathways in an estuarine ecosystem
Authors: Khanna Shruti , Santos Maria J. , Boyer Jennifer D. , Shapiro Kristen D. , Bellvert Joaquim , Ustin Susan L.
Published: September 2018

Invasive species fundamentally change the bio‐physical and ecological characteristics of the ecosystems they invade. Rapidly expanding invasive species may facilitate the spread of other invasive species, and successive invasion events may lead to novel species interactions that may push the system beyond its equilibrium state and change successional pathways. Knowing the direction of the invasion front may be useful to predict impacts of invasive species. Water primrose (Ludwigia spp.), one of the invasive floating macrophytes in the Sacramento‐San Joaquin River Delta (hereafter, Delta), has increased in cover rapidly over the past three decades likely outcompeting native and non‐native species, changing their functional relationships, with cascading effects in the macrophyte communities of the aquatic ecosystem. In this study, we analyze the directionality of water primrose invasion and assess which spaces it occupies, whether it has overcrowded or outcompeted other vegetation communities, and its implications for succession in the Delta. We used imaging spectroscopy data acquired in June of 2004, June of 2008, November of 2014, and October of 2016 for the 2500 km2 of the Delta to map the communities of submerged macrophytes, floating macrophytes, and emergent marsh. We found that water primrose cover increased fourfold in the Delta over the past 13 yr, changing significantly in the central Delta and Liberty Island region from 122 ha in 2004 to 471 ha in 2016. Water primrose expanded first by spreading over open water and submerged macrophytes and, when that habitat was exhausted, primrose invasion switched direction and encroached into emergent marsh. This bilateral expansion to both open water and the marsh is likely to change rates of succession and affect the restoration of the native Delta marshes. Understanding the mechanisms behind the expansion dynamics of this invasive will allow managers to counter its impact on newly established vulnerable marshes.