bluuebunny/crossref_metadata_2025 huggingface dataset:
Decentralized robust adaptive neural dynamic surface control for multi‐machine excitation systems with static var compensator
Authors: Zhang Xiuyu , Wang Shuran , Zhu Guoqiang , Ma Jia , Li Xiaoming , Chen Xinkai
Published: November 2018

Focusing on solving the control problem of the multimachine excitation systems with static var compensator (SVC), this paper proposes a decentralized neural adaptive dynamic surface control (DNADSC) scheme, where the radial basis function neural networks are used to approximate the unknown nonlinear dynamics of the subsystems and compensate the unknown nonlinear interactions. The main advantages of the proposed DNADSC scheme are summarized as follows: (1) the strong nonlinearities and complexities are mitigated when the SVC equipment are introduced to the multimachine excitation systems and the explosion of complexity problem of the backstepping method is overcome by combining the dynamic surface control method with neural networks (NNs) approximators; 2) the tracking error of the power angle can be kept in the prespecified performance curve by introducing the error transformed function; (3) instead of estimating the weighted vector itself, the norm of the weighted vector of the NNs are estimated, leading to the reduction of the computational burden. It is proved that all the signals in the multimachine excitation system with SVC are semiglobally uniformly ultimately bounded.
Adaptive state‐feedback control with sensor failure compensation for asymptotic output tracking
Authors: Song Ge , Tao Gang
Published: November 2018

This paper addresses a new adaptive output tracking problem in the presence of uncertain plant dynamics and uncertain sensor failures. A new unified nominal state‐feedback control law is developed to deal with various sensor failures, which is directly constructed by state sensor outputs. Such a new state‐feedback compensation control law is able to ensure the desired plant‐model matching properties under different failure patterns. Based on the nominal compensation control design, a new adaptive compensation control scheme is proposed, which guarantees closed‐loop signal boundedness and asymptotic output tracking. The new adaptive compensation scheme not only expands the sensor failures types that the system could tolerate but also avoids some signal processing procedures that the traditional fault‐tolerant control techniques are forced to encounter. A complete stability analysis and a representative simulation study are conducted to evaluate the effectiveness of the proposed adaptive compensation control scheme.
Experimental and Theoretical Insights into the Bioinspired Formation of Disordered Ba‐Calcite
Authors: Seknazi Eva , Levy Davide , Polishchuk Iryna , Katsman Alex , Pokroy Boaz
Published: November 2018

Calcite has the ability to host large amounts of intracrystalline inclusions, a phenomenon that is known to be the case in biominerals and has been demonstrated in bioinspired synthetic systems. In this study, barium ion is focused on as the inclusion. Highly substituted Ba‐calcite possesses disordered carbonate orientations, characteristic of symmetry. It is shown that calcite experiences an order–disorder transition, in which the carbonate groups undergo progressive loss of their rotational order with increasing amounts of incorporated Ba, and reach complete rotational disorder for a critical amount of Ba. This transition is characterized and a theoretical model justifying the influence of Ba is proposed. Moreover, the disordered Ba‐substituted calcite has been previously identified as a high‐temperature phase or as a highly metastable room‐temperature phase. Those descriptions are challenged by successfully synthesizing it under slow‐rate conditions and by studying its thermal behavior, and it is concluded that the fully disordered Ba‐calcite is stable, whereas the transitional, partially disordered Ba‐calcite phase is metastable.
Carbazole–Dibenzofuran Dyads as Metal‐Free Single‐Component White‐Color Photoemitters
Authors: Tabata Kenichi , Yamada Tetsuya , Kita Hiroshi , Yamamoto Yohei
Published: November 2018

White‐color light emitters from single organic molecule without heavy metals are valuable for practical applications in organic light‐emitting devices. In this study, carbazole (Cz)–dibenzofuran (DBF) donor–acceptor dyads are designed for white‐color light emitters. Originally, these molecules show photoluminescence (PL) in near ultraviolet region. However, upon successive ultraviolet (UV) irradiation, white‐color PL appears, comprising dual‐color phosphorescence from the amorphous and crystalline state of the dyad. A continuous UV irradiation makes the twisting angle between the Cz and DBF planes flatten through the triplet‐excited state, which proceeds crystallization. Thermal annealing and UV irradiation can switch the blue‐ and white‐color phosphorescences from the dyad. Furthermore, charge injection generates white‐color electroluminescence. The materials with PL color modulation ability by UV‐light irradiation and heating can be applicable as light‐ and thermo‐sensors.
Pillared MXene with Ultralarge Interlayer Spacing as a Stable Matrix for High Performance Sodium Metal Anodes
Authors: Luo Jianmin , Wang Chuanlong , Wang Huan , Hu Xiaofei , Matios Edward , Lu Xuan , Zhang Wenkui , Tao Xinyong , Li Weiyang
Published: November 2018

Sodium (Na) metal is a promising alternative to lithium metal as an anode material for the next‐generation energy storage systems due to its high theoretical capacity, low cost, and natural abundance. However, dendritic/mossy Na growth caused by uncontrollable plating/stripping results in serious safe concerns and rapid electrode degradation. This study presents Sn2+ pillared Ti3C2 MXene serving as a stable matrix for high‐performance dendrite‐free Na metal anode. The intercalated Sn2+ between Ti3C2 layers not only induces Na to nucleate and grow within Ti3C2 interlayers, but also endows the Ti3C2 with larger interlayer space to accommodate the deposited Na by taking advantage of the “pillar effect,” contributing to uniform Na deposition. As a result, the pillar‐structured MXene‐based Na metal electrode could enable high current density (up to 10 mA cm−2) along with high areal capacity (up to 5 mAh cm−2) over long‐term cycling (up to 500 cycles). The full cell using MXene‐based Na metal anode exhibits superior electrochemical performance than that using host‐less commercial Na. It is believed that the well‐controlled MXene‐based Na anode not only extends the application scope of MXene, but also provides guidance in designing high‐performance Na metal batteries.
Hybrid Nanovehicles: One Machine, Two Engines
Authors: Chen Chuanrui , Soto Fernando , Karshalev Emil , Li Jinxing , Wang Joseph
Published: November 2018

Nanomotors have emerged as promising and versatile nanorobotic tools in a variety of medical, sensing, decontamination, and manufacturing applications due to their unique ability to operate and perform task at small scales. This review focuses on the current progress and future perspectives of hybrid nanomotors based on two power sources, with a special highlight on their distinct advantages, unique propulsion behaviors, adaptive operation, and potential applications. Such incorporation of multiple engines into a single nanoscale vehicle addresses certain limitations of nanomotors based on a single propulsion mode and adds new dimensions for advanced motion management. These attractive capabilities of hybrid nanoscale vehicles are discussed along with the challenges and opportunities when coupling several propulsion modes into a single device. With continuous innovations, it is expected that hybrid nanomotors will have a profound impact upon the field of nanorobotics.
Opportunities and Challenges of Interface Engineering in Bimetallic Nanostructure for Enhanced Electrocatalysis
Authors: Shao Qi , Wang Pengtang , Huang Xiaoqing
Published: November 2018

The development of bimetal based catalysts via interfacial engineered strategy has been intensively explored due to its great potential for enhancing the electrochemical performance. The significant progress achieved by the interfacial engineering is mainly derived from its great ability on tuning the intermediate adsorption, controlling the electron and mass transportation, preventing catalysts from serious aggregation, as well as providing advanced promoter for the rational design of highly efficient catalysts. Here, the recent works on the interfacial engineered strategy for developing highly efficient bimetal based electrocatalysts are outlined. The advantages of interfacial engineered strategy on manipulating the activity, selectivity, and stability of catalysts are first discussed. The recent synthetic approaches for controlling the interface structures and the related hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, and electroreduction of carbon dioxide are elaborated based on three major categories, involving metal/metal, metal/metal compound, and metal/support interfaces. Challenges and perspectives of this field are represented in the final section.
Direct Stereolithographic 3D Printing of Microfluidic Structures on Polymer Substrates for Printed Electronics
Authors: Zips Sabine , Wenzel Ole Jonas , Rinklin Philipp , Grob Leroy , Terkan Korkut , Adly Nouran Yehia , Weiß Lennart , Wolfrum Bernhard
Published: November 2018

Both stereolithographic printing of microfluidics and inkjet printing of electronics are promising tools for the fabrication of lab‐on‐a‐chip devices. However, the combination of these two technologies has been a challenge so far, as the 3D‐printed components usually have to be bonded manually to the substrates functionalized with printed electronics. Here, a surface modification method is demonstrated for enabling the direct stereolithographic printing of microfluidic structures onto a variety of different substrates that are usually employed for printed electronics. The approach makes use of an acrylate‐terminated silane that covalently binds substrate and polymer network of the 3D print. The bonding strength is quantified and the compatibility of the concept with printed electrodes in a microfluidic channel is evaluated.
Switchable Holographic Device Based on Reversible Electrodeposition
Authors: Cho Seong M. , Kim Sujung , Kim Yong‐Hae , Hwang Chi‐Young , Kim Tae‐Youb , Cheon Sang Hoon , Kim Joo Yeon , Ah Chil Seong , Song Juhee , Ryu Hojun , Hwang Chi‐Sun , Lee Jeong‐Ik
Published: November 2018

A new switchable holographic device concept using reversible electrodeposition (RED) technology is proposed. The proposed device has a structure in which the cavity structure is changed by the reversible deposition of Ag, and thus the characteristics of the reflected light are modulated. It has a high reflectance due to a mirror reflection structure and exhibits phase modulation by the reversible deposition of Ag. Because the proposed device is a current‐driven device, it is expected to overcome the limitation in the scaling down of the pitch in spatial light modulators, which is considered a limitation of liquid crystal device. A passive type switchable holographic device with a 1 µm pitch is implemented using the proposed device. The successful implementation of a switchable holographic image using the fabricated device is confirmed. The proposed device is expected to be applicable as an active metasurface and spatial light modulator device in the visible light region in the future because it has a large modulation in the visible light region.
Static Regulation and Dynamic Evolution of Single‐Atom Catalysts in Thermal Catalytic Reactions
Authors: Li Hongliang , Wang Menglin , Luo Laihao , Zeng Jie
Published: November 2018

Single‐atom catalysts provide an ideal platform to bridge the gap between homogenous and heterogeneous catalysts. Here, the recent progress in this field is reported from the perspectives of static regulation and dynamic evolution. The syntheses and characterizations of single‐atom catalysts are briefly discussed as a prerequisite for catalytic investigation. From the perspective of static regulation, the metal–support interaction is illustrated in how the supports alter the electronic properties of single atoms and how the single atoms activate the inert atoms in supports. The synergy between single atoms is highlighted. Besides these static views, the surface reconstruction, such as displacement and aggregation of single atoms in catalytic conditions, is summarized. Finally, the current technical challenges and mechanistic debates in single‐atom heterogeneous catalysts are discussed.
Cascade Reaction in Human Live Tissue Allows Clinically Applicable Diagnosis of Breast Cancer Morphology
Authors: Tanei Tomonori , Pradipta Ambara R. , Morimoto Koji , Fujii Motoko , Arata Mayumi , Ito Akihiro , Yoshida Minoru , Saigitbatalova Elena , Kurbangalieva Almira , Ikeda Jun‐ichiro , Morii Eiichi , Noguchi Shinzaburo , Tanaka Katsunori
Published: November 2018

Clean operating margins in breast cancer surgery are important for preventing recurrence. However, the current methods for determining margins such as intraoperative frozen section analysis or imprint cytology are not satisfactory since they are time‐consuming and cause a burden on the patient and on hospitals with a limited accuracy. A “click‐to‐sense” probe is developed based on the detection of acrolein, which is a substance released by oxidatively stressed cancer cells and can be visualized under fluorescence microscopy. Using live breast tissues resected from breast cancer patients, it is demonstrated that this method can quickly, selectively, and sensitively differentiate cancer lesion from normal breast gland or benign proliferative lesions. Since acrolein is accumulated in all types of cancers, this method could be used to quickly assess the surgical margins in other types of cancer.
A Cost Analysis of Fully Solution‐Processed ITO‐Free Organic Solar Modules
Authors: Guo Jie , Min Jie
Published: November 2018

Organic photovoltaics (OPVs) have become a potential candidate for clean and renewable photovoltaic productions. This work examines the current cost drivers and potential avenues to reduce costs for organic solar modules by constructing a comprehensive bottom‐up cost model. The direct manufacturing cost (MC) and the minimum sustainable price (MSP) for an opaque single solar module (SSM) (MC = 187 ¥ m−2, MSP = 297 ¥ m−2) and for a tandem solar module (MC = 224 ¥ m−2, MSP = 438 ¥ m−2) are analyzed in detail. Within this calculation, the most expensive layers and processing steps are identified and highlighted. Importantly, the low levelized cost of energy (LCOE) value for an SSM with a 10% power conversion efficiency in a 20‐year range from 0.185 to 0.486 ¥ kWh−1, with a national average of 0.324 ¥ kWh−1 in China under an average solar irradiance of 1200 kWh m−2 year−1. Moreover, the impact on the cost of alternative materials and constructions, process throughputs, module efficiency, and module lifetime, etc., is presented and avenues to further reduce the MSP and LCOE values are indicated. The analysis shows that OPVs can emerge as a competitive alternative to established power generation technologies if the remaining issues (e.g., active layer material cost, module efficiency, and lifetime) can be resolved.
Reducing Saturation‐Current Density to Realize High‐Efficiency Low‐Bandgap Mixed Tin–Lead Halide Perovskite Solar Cells
Authors: Li Chongwen , Song Zhaoning , Zhao Dewei , Xiao Chuanxiao , Subedi Biwas , Shrestha Niraj , Junda Maxwell M. , Wang Changlei , Jiang Chun‐Sheng , Al‐Jassim Mowafak , Ellingson Randy J. , Podraza Nikolas J. , Zhu Kai , Yan Yanfa
Published: November 2018

The unsatisfactory performance of low‐bandgap mixed tin (Sn)–lead (Pb) halide perovskite subcells has been one of the major obstacles hindering the progress of the power conversion efficiencies (PCEs) of all‐perovskite tandem solar cells. By analyzing dark‐current density and distribution, it is identified that charge recombination at grain boundaries is a key factor limiting the performance of low‐bandgap mixed Sn–Pb halide perovskite subcells. It is further found that bromine (Br) incorporation can effectively passivate grain boundaries and lower the dark current density by two–three orders of magnitude. By optimizing the Br concentration, low‐bandgap (1.272 eV) mixed Sn–Pb halide perovskite solar cells are fabricated with open‐circuit voltage deficits as low as 0.384 V and fill factors as high as 75%. The best‐performing device demonstrates a PCE of >19%. The results suggest an important direction for improving the performance of low‐bandgap mixed Sn–Pb halide perovskite solar cells.
Iron, erythropoietin, and inflammation regulate hepcidin in Bmp2‐deficient mice, but serum iron fails to induce hepcidin in Bmp6‐deficient mice
Authors: Wang Chia‐Yu , Canali Susanna , Bayer Abraham , Dev Som , Agarwal Aneesh , Babitt Jodie L.
Published: November 2018

The bone morphogenetic protein (BMP)‐SMAD signaling pathway is a key transcriptional regulator of hepcidin in response to tissue iron stores, serum iron, erythropoietic drive and inflammation to increase the iron supply when needed for erythropoiesis, but to prevent the toxicity of iron excess. Recently, BMP2 was reported to play a non‐redundant role in hepcidin regulation in addition to BMP6. Here, we used a newly validated BMP2 ELISA assay and mice with a global or endothelial conditional knockout (CKO) of Bmp2 or Bmp6 to examine how BMP2 is regulated and functionally contributes to hepcidin regulation by its major stimuli. Erythropoietin (EPO) did not influence BMP2 expression in control mice, and still suppressed hepcidin in Bmp2 CKO mice. Lipopolysaccharide (LPS) reduced BMP2 expression in control mice, but still induced hepcidin in Bmp2 CKO mice. Chronic dietary iron loading that increased liver iron induced BMP2 expression, whereas acute oral iron gavage that increased serum iron without influencing liver iron did not impact BMP2. However, hepcidin was still induced by both iron loading methods in Bmp2 CKO mice, although the degree of hepcidin induction was blunted relative to control mice. Conversely, acute oral iron gavage failed to induce hepcidin in Bmp6
−/− or CKO mice. Thus, BMP2 has at least a partially redundant role in hepcidin regulation by serum iron, tissue iron, inflammation and erythropoietic drive. In contrast, BMP6 is absolutely required for hepcidin regulation by serum iron.
Coping style and cortisol levels in infancy predict hair cortisol following new group formation in captive rhesus macaques (Macaca mulatta)
Authors: Linden Julie B. , Capitanio John P. , McCowan Brenda , Isbell Lynne A.
Published: November 2018

Social instability in primate groups has been used as a model to understand how social stress affects human populations. While it is well established that individual cercopithecines have different temperaments or personalities, little is known about how temperament mediates the experience of social instability in large, naturalistic groups. Here, we report findings from a study tracking a newly formed group of captive rhesus macaques (Macaca mulatta). We examine whether inter‐individual differences in temperament during infancy affect physiological responses to new group formation years later, measured through hair cortisol 9 months after the group was formed. Our results show that early life measures of temperament characteristics predict later‐life hypothalamic‐pituitary‐adrenal activity following new group formation, though not always in the directions we predicted. Individuals with higher blood cortisol concentrations in response to a novel stressor and lower blood cortisol concentrations following a Dexamethasone Suppression Test in infancy had lower hair cortisol values following new group formation later in life. Individuals characterized in infancy as more emotional or more active exhibited lower hair cortisol profiles 9 months after group formation. We suggest that these two temperament characteristics, emotionality and activity, may represent two different mechanisms leading to low hair cortisol values. That is, the physiological measure of low hair cortisol may have two different meanings depending on temperament characteristics of the individual. Our results demonstrate that temperament and physiological responsiveness measures in infancy can predict individual responses to a new group formation years later.
Induction of smell through transethmoid electrical stimulation of the olfactory bulb
Authors: Holbrook Eric H. , Puram Sidharth V. , See Reiner B. , Tripp Aaron G. , Nair Dinesh G.
Published: November 2018

Background

Anosmia has an estimated prevalence of 5% of the general population. Outside of inflammatory causes, therapeutic options are limited despite research advances. Bypassing peripheral neuronal damage through central stimulation is a potential therapeutic option that has shown success in other sensory systems, most notably with hearing. We performed a pilot study to determine the feasibility of inducing smell through artificial electrical stimulation of the olfactory bulbs in humans.

Methods

Subjects with a history of sinus surgery, including total ethmoidectomy, with intact ability to smell were enrolled. The ability to smell was confirmed with a 40‐item smell identification test. Awake subjects underwent nasal endoscopy and either a monopolar or bipolar electrode was positioned at 3 areas along the lateral lamella of the cribriform plate within the ethmoid sinus cavity. A graded stimulation current of 1–20 mA at 3.17 Hz was administered while cortical evoked potential (CEP) recordings were collected. Subjective responses of perceived smell along with reports of discomfort were recorded. Subjects with artificially induced smell underwent repeat stimulation after medically induced anosmia.

Results

Five subjects (age, 43–72 years) were enrolled. Three subjects reported smell perception smell with electrical stimulation. This was reproducible after inducing anosmia, but CEP recordings could not provide objective support. All subjects tolerated the study with minimal discomfort.

Conclusion

This is the first report of induced smell through transethmoid electrical stimulation of the olfactory bulb. These results provide a proof of concept for efforts in development of an olfactory implant system.
Direct Evidence for Ferrous Ion Oxidation and Incorporation in the Absence of Oxidants by Dps from Marinobacter hydrocarbonoclasticus
Authors: Penas Daniela , Pereira Alice S. , Tavares Pedro
Published: November 2018

Dps proteins (DNA‐binding protein from starved cells) are hollow‐sphere‐shaped, dodecameric enzymes found in bacteria and archaeal species. They can oxidize ferrous iron in a controlled manner using hydrogen peroxide or molecular oxygen as co‐substrate, and most of them confer physical protection through DNA binding. Oxidized iron is stored, as a mineral core, in a central cavity. Direct evidence is now provided that, furthermore, Dps proteins containing small mineral cores can oxidize and mineralize toxic ferrous ions in anaerobic conditions and in the absence of any additional aqueous oxidant co‐substrate. Dps proteins containing cores of 24 irons per dodecamer can oxidize about 5 ferrous irons per dodecamer, with that number approximately doubling for protein particles containing in average 96 irons per protein. This additional activity carries importance as it can be a detoxification mechanism present during anaerobic or oxygen‐limited growth conditions.
Supramolekulare Kapseln: starke und schwache Chalkogenbrücken im Vergleich
Authors: Riwar Leslie‐Joana , Trapp Nils , Root Katharina , Zenobi Renato , Diederich François
Published: November 2018

Resorcin[4]aren‐Cavitanden, entweder mit einem 2,1,3‐Benzotelluradiazol‐ oder einem 2,1,3‐Benzothiadiazol‐Motiv versehen, wurden zu chalkogenverbrückten, supramolekularen Kapseln dimerisiert. Ihr jeweiliges Verhalten variierte in Abhängigkeit von der Assoziationsstärke, wobei Te starke und S schwache Wechselwirkungen einging. Die enorme Stärke einer Vielzahl von 2Te‐2N‐Quadratwechselwirkungen führte in allen Lösungsmitteln zur Bildung einer chalkogenverbrückten, dimeren Kapsel. Dies wurde durch Röntgenkristallstrukturen mit 16 kleinen Te⋅⋅⋅N‐Abständen (≤2.9 Å) gezeigt und mittels nativer Elektrospray‐Ionisations‐Massenspektrometrie belegt. Beim S‐Cavitanden führte die lösungsmittelabhängige Kristallisation zu unterschiedlichen Anordnungen: entweder zu einer versetzten Kapsel mit 2S‐2N‐Quadratwechselwirkungen oder zu einem ineinandergreifenden 1D‐Polymer mit einem unendlichen π‐π‐Stapelnetzwerk. Die Assoziationskonstante zur Bildung der versetzten S‐Kapsel in [D8]THF bei 283 K, die allein auf schwachen 2S‐2N‐Quadratwechselwirkungen basiert, wurde als Ka=786 m−1 bestimmt.
Supramolecular Capsules: Strong versus Weak Chalcogen Bonding
Authors: Riwar Leslie‐Joana , Trapp Nils , Root Katharina , Zenobi Renato , Diederich François
Published: November 2018

Resorcin[4]arene cavitands containing either 2,1,3‐benzotelluradiazole or 2,1,3‐benzothiadiazole motifs were dimerized to supramolecular capsules by chalcogen bonding. Their respective behavior varied depending on the interaction strength of the chalcogen bonds with Te forming strong interactions and S weak interactions. The tremendous strength of multiple 2Te–2N square interactions led to formation of a chalcogen‐bonded dimeric capsule in all solvents, as shown by X‐ray crystal structures with 16 short Te⋅⋅⋅N distances (≤2.9 Å) and confirmed by native electrospray ionization mass spectrometry (ESI‐MS). With the S cavitand, solvent‐dependent crystallization resulted in different arrangements: either a shifted 2S–2N square‐bonded capsule or an interlocked 1D polymer with an infinite π–π stacking array. The association constant to form the dimeric capsule in [D8]THF at 283 K, solely based on weak 2S–2N square interactions, was determined as Ka=786 m−1.
Decreasing Surgical Site Infections by Developing a High Reliability Culture
Authors: Pettis Ann Marie
Published: November 2018

Today's fast‐paced and complex perioperative setting requires a collaborative and mindful approach to implementing evidence‐based practices and preventing patient harm. Recent changes in the health care landscape coupled with the potential harm caused by surgical site infections require a shift in culture in which all members of the perioperative team have zero tolerance for preventable harm. This article discusses high‐reliability organizations and examples of ways in which perioperative teams can apply the principles of high reliability to the prevention of surgical site infections. Characteristics of high‐reliability organizations include mindfulness, collaboration, standardization, and use of a structured model to implement evidence into practice. By understanding and applying these concepts and others described in this article, members of a multidisciplinary team should be more prepared to ensure that all staff members are following evidence‐based practices during every patient encounter.
Results of the 2018 AORN Salary and Compensation Survey
Authors: Bacon Donald R. , Stewart Kim A.
Published: November 2018

AORN conducted its 16th annual compensation survey for perioperative nurses in June 2018. A multiple regression model was used to examine how several variables, including job title, education level, certification, experience, and geographic region, affect perioperative nurse compensation. Comparisons between the 2018 data and data from previous years are presented. The effects of other forms of compensation (eg, on‐call compensation, overtime, bonuses, shift differentials, benefits) on total compensation also are examined. Additional analyses explore the current state of the nursing shortage and the sources of job satisfaction and dissatisfaction.
The Importance of Leak Testing Flexible Endoscopes
Authors: Rojo Cheron
Published: November 2018

Leak testing is a vital processing step that detects fluid invasion in an endoscope. Endoscopes that are inadequately leak tested can pose a risk for transmission of infection or injury to patients. If not detected, fluid invasion of an endoscope can damage the endoscope and increase repair costs. This article presents evidence to support leak testing, provides recommendations for correct leak testing, explains reasons for leak‐testing failures, and discusses a case scenario with a failed leak test and the approach that facility personnel took to improve the quality and consistency of leak testing their endoscopes.
Gas sensor for ammonia detection based on poly(vinyl alcohol) and polyaniline electrospun
Authors: Bittencourt Jéssyka Carolina , de Santana Gois Bruno Henrique , Rodrigues de Oliveira Vinicius Jessé , da Silva Agostini Deuber Lincon , de Almeida Olivati Clarissa
Published: November 2018

In this article, the results of the process and fabrication of ammonia gas sensors are obtained through the production of poly(vinyl alcohol) and polyaniline (PVA/PANI) nanofibers in different concentrations deposited on interdigitated electrodes (IDEs) The results showed good interaction between PVA and PANI, as well as the solvents involved, with good adhesion of the nanofibers in substrate, shown for morphological analysis by scanning electron microscopy (SEM). The good performance of the gas sensor was carried out by direct current measurements. It has been proven that the high surface density, dimensions, and quality of nanofibers are essential parameters for a good response of the ammonia gas sensor. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47288.
Electrosynthesis and characterizations of a multielectrochromic copolymer based on aniline and o‐nitroaniline in visible‐infrared region
Authors: Zhang Bo , Xu Chen , Xu Guoyue , Liu Chuyang , Zhang Jianchao , Guo Tengchao , Bu Honghan
Published: November 2018

An IR electrochromic film constructed by copolymer of aniline and o‐nitroaniline has been successfully prepared by cyclic voltammetry. The effects of polymerization of aniline and o‐nitroaniline on electrochromic properties and optical properties were investigated by cyclic voltammetry, scanning electron microscopy, FTIR spectrometer, and UV–vis spectrophotometer. The results indicate that the film can exhibit three colors (apple green, dark green, and dark blue) at different voltages of −0.1, 0, and 0.8 V. Simultaneously, a fast response time (1.89 and 4.47 s), a high coloration efficiency, a significant optical modulation (60% between −0.1 and 0.8 V) and a large average emissivity range (Δεmax = 0.203) are achieved for the new film. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47290.
Antidiabetic potential: In vitro inhibition effects of bromophenol and diarylmethanones derivatives on metabolic enzymes
Authors: Demir Yeliz , Taslimi Parham , Ozaslan Muhammet Serhat , Oztaskin Necla , Çetinkaya Yasin , Gulçin İlhami , Beydemir Şükrü , Goksu Suleyman
Published: November 2018

Aldose reductase converts glucose to sorbitol in the polyol pathway. It is an important enzyme to prevent diabetic complications. In this study, we studied the inhibitory effects of bromophenol derivatives on aldose reductase (AR), α‐glucosidase, and α‐amylase enzymes. In the bromophenols series, compound 1f showed the maximum inhibition effect against AR with a Ki value of 0.05 ± 0.01 μM, while compound 1d showed the lowest inhibition effect against AR with a Ki value of 1.13 ± 0.99 μM. In addition, α‐amylase from porcine pancreas and α‐glucosidase from Saccharomyces cerevisiae were used as enzymes. In this study, all compounds were tested for the inhibition of the α‐glucosidase enzyme and demonstrated efficient inhibition profiles with Ki values in the range of 43.62 ± 5.28 to 144.37 ± 16.37 nM against α‐glucosidase. Additionally, these compounds were tested against the α‐amylase enzyme, which determined an effective inhibition profile with IC50 values in the range of 9.63–91.47 nM. These compounds can be selective inhibitors of AR, α‐glucosidase, and α‐amylase enzymes as antidiabetic agents.
Alkylated Aromatic Thioethers with Aggregation‐Induced Emission Properties—Assembly and Photophysics
Authors: Riebe Steffen , Saccone Marco , Stelzer Jacqueline , Sowa Andrea , Wölper Christoph , Soloviova Kateryna , Strassert Cristian A. , Giese Michael , Voskuhl Jens
Published: November 2018

In this contribution, we present the synthesis and self‐assembly of alkylated thioethers with interesting photophysical properties. To this end, the emission, absorption and excitation spectra in organic solvents and as aggregates in water were measured as well as the corresponding photoluminescence quantum yields and lifetimes. The aggregates in aqueous media were visualized and measured using transmission electron microscopy. Besides that, crystal structures of selected compounds allowed a detailed discussion of the structure–property relationship. Furthermore, the mesomorphic behavior was investigated using polarized optical microscopy (POM) as well as differential scanning calorimetry (DSC).
Terminal sliding mode observers for uncertain linear systems with matched disturbance
Authors: Mousavi Mohammad , Rahnavard Mostafa , Ayati Moosa , Hairi Yazdi Mohammad Reza
Published: November 2018

In this paper, a terminal sliding mode observer (TSMO) for systems with general state‐space representation is proposed. The effects of uncertainties and matched disturbances are incorporated in the system dynamics. Compared to conventional sliding mode observers, which are capable of finite time convergence of the measured states’ (outputs) errors and asymptotic convergence of unmeasured states’ errors, the proposed TSMO guarantees finite time convergence of all states. Three appropriate Lyapunov functions are defined for proving robust and finite time convergence of all state estimation errors of the TSMO. In addition, to highlight the effectiveness of the methodology, the developed TSMO is applied to a well‐known realistic wind turbine model. Results confirm that the proposed TSMO estimates all the states in finite time with good accuracy.
Model‐Reference Adaptive Moment Control of Uncertain Nonlinear Stochastic Systems
Authors: Beheshtipour Zohreh , Khaloozadeh Hamid , Amjadifard Roya
Published: November 2018

In this paper, a new model‐reference adaptive moment control method is proposed to control the first and second moments of an uncertain nonlinear system with additive external stochastic excitation. This method has established a closed‐loop control system that calculates an adaptive stochastic nonlinear input by introducing a Lyapunov function and adaptive update law. The proposed adaptive structure is innovative in trying to minimize two errors simultaneously: the moments tracking error and the error between the nonlinear system output and reference model. Furthermore, the proposed method can control the expected and covariance matrices of the states without needing to solve the complicated Fokker‐Planck‐Kolmogorov differential equation or using the approximate methods. Simulation has been performed on two practical examples, which show a good performance for the designed controller.
System reliability and component importance when components can be swapped upon failure
Authors: Najem Aesha , Coolen Frank P. A.
Published: November 2018

Resilience of systems to failures during functioning is of great practical importance. One of the strategies that might be considered to enhance reliability and resilience of a system is swapping components when a component fails, thus replacing it by another component from the system that is still functioning. This paper studies this scenario, particularly with the use of the survival signature to quantify system reliability, where it is assumed that such a swap of components requires these components to be of the same type. We examine the effect of swapping components on a reliability importance measure for the specific components, and we also consider the joint reliability importance of two components. Such swapping of components may be an attractive means toward more resilient systems and could be an alternative to adding more components to achieve redundancy of repair and replacement activities.
A Bayesian joint model of recurrent events and a terminal event
Authors: Li Zheng , Chinchilli Vernon M. , Wang Ming
Published: November 2018

Recurrent events could be stopped by a terminal event, which commonly occurs in biomedical and clinical studies. In this situation, dependent censoring is encountered because of potential dependence between these two event processes, leading to invalid inference if analyzing recurrent events alone. The joint frailty model is one of the widely used approaches to jointly model these two processes by sharing the same frailty term. One important assumption is that recurrent and terminal event processes are conditionally independent given the subject‐level frailty; however, this could be violated when the dependency may also depend on time‐varying covariates across recurrences. Furthermore, marginal correlation between two event processes based on traditional frailty modeling has no closed form solution for estimation with vague interpretation. In order to fill these gaps, we propose a novel joint frailty‐copula approach to model recurrent events and a terminal event with relaxed assumptions. Metropolis–Hastings within the Gibbs Sampler algorithm is used for parameter estimation. Extensive simulation studies are conducted to evaluate the efficiency, robustness, and predictive performance of our proposal. The simulation results show that compared with the joint frailty model, the bias and mean squared error of the proposal is smaller when the conditional independence assumption is violated. Finally, we apply our method into a real example extracted from the MarketScan database to study the association between recurrent strokes and mortality.
Cellular physiology controls photoautotrophic production of 1,2‐propanediol from pools of CO2 and glycogen
Authors: David Christian , Schmid Andreas , Bühler Katja
Published: November 2018

Synechocystis sp. PCC 6803 PG is a cyanobacterial strain capable of synthesizing 1,2‐propanediol from carbon dioxide (CO2) via a heterologous three‐step pathway and a methylglyoxal synthase (MGS) originating from Escherichia coli as an initial enzyme. The production window is restricted to the late growth and stationary phase and is apparently coupled to glycogen turnover. To understand the underlying principle of the carbon partitioning between the Calvin‐Benson‐Bassham (CBB) cycle and glycogen in the context of 1,2‐propanediol production, experiments utilizing 13C labeled CO2 have been conducted. Carbon fluxes and partitioning between biomass, storage compounds, and product have been monitored under permanent illumination as well as under dark conditions. About one‐quarter of the carbon incorporated into 1,2‐propanediol originated from glycogen, while the rest was derived from CO2 fixed in the CBB cycle during product formation. Furthermore, 1,2‐propanediol synthesis was depending on the availability of photosynthetic active radiation and glycogen catabolism. We postulate that the regulation of the MGS from E. coli conflicts with the heterologous reactions leading to 1,2‐propanediol in Synechocystis sp. PCC 6803 PG. Additionally, homology comparison of the genomic sequence to genes encoding for the methylglyoxal bypass in E. coli suggested the existence of such a pathway also in Synechocystis sp. PCC 6803. These findings are critical for all heterologous pathways coupled to the CBB cycle intermediate dihydroxyacetone phosphate via a MGS and reveal possible engineering targets for rational strain optimization.
A comparison of 3D ultrasound to MRI for the measurement and estimation of gastrocnemius muscle volume in adults and young people with and without cerebral palsy
Authors: Noorkoiv Marika , Theis Nicola , Lavelle Grace
Published: November 2018

Muscle volume (MV) is an important parameter for understanding muscle morphology and adaptations to training, growth and pathology. In this study, we assessed the validity of freehand 3D ultrasound (3DUS) for measuring medial gastrocnemius MV in adults, typically developing (TD) children and children with cerebral palsy (CP). We also assessed the validity between our direct measures of MV and estimates derived from anatomical cross sectional area (ACSA) and muscle length (ML), using previously outlined methods. The medial gastrocnemius of all groups was scanned with 3DUS and MRI. Images from both methods were digitized to derive MV, ACSA and ML. Measured MV was compared between methods and compared to estimated MV derived from recently published algorithms. MV had a mean difference of −0.13% (standard error of estimate (SEE) = 2.23%, R2 = 0.99) between MRI and 3DUS and 19.82% (SEE = 4.73% and R2 = 0.99) and −3.11% (SEE = 6.55%, R2 = 0.99) mean differences between the measured and estimated MV from two methods of estimation. The 3DUS is a valid method for the measurement of MV in adults, TD children and those with CP. Estimation methods of MV may be useful in clinical practice, but require further replication on various populations and careful methodological consideration. Clin. Anat. 32:319–327, 2019. © 2018 Wiley Periodicals, Inc.
How Palestinian students invoke the category “human” to challenge negative treatment and media representations
Authors: Heywood Emma , Goodman Simon
Published: November 2018

Dehumanisation of opponents in conflict has been shown to be a common and damaging feature in the media. What is not understood is how this dehumanisation is challenged, which is the novel contribution that this research will make. Drawing on focus groups (four focus groups each with four to six participants) conducted in the West Bank in 2015 that discussed media coverage of international conflict, this article demonstrates the ways in which young Palestinian participants attempt to rehumanize themselves in the context of the Israeli–Palestinian conflict. Discursive analysis demonstrates how this was achieved in a number of ways: categorising Palestinians as “human being”; by directly and explicitly challenging the suggestion that Palestinians are less than human; by drawing the enemy into the category “human”; and by embodying the “human.” These findings, the first to address the talk of young Palestinians about the reporting of violent conflicts around the world, demonstrate the importance of categorization and how, in this case, the specifics of the use of the (human) category work to rehumanize Palestinians in the face of (claims of) dehumanisation.
Chemical Biology of Protein N‐Terminal Methyltransferases
Authors: Huang Rong
Published: November 2018

Protein α‐N‐terminal methylation is catalyzed by protein N‐terminal methyltransferases. The prevalent occurrence of this methylation in ribosomes, myosin, and histones implies its function in protein–protein interactions. Although its full spectrum of function has not yet been outlined, recent discoveries have revealed the emerging roles of α‐N‐terminal methylation in protein–chromatin interactions, DNA damage repair, and chromosome segregation. Herein, an overview of the discovery of protein N‐terminal methyltransferases and functions of α‐N‐terminal methylation is presented. In addition, substrate recognition, mechanisms, and inhibition of N‐terminal methyltransferases are reviewed. Opportunities and gaps in protein α‐N‐terminal methylation are also discussed.
Embolic stroke of undetermined source and patent foramen ovale closure: Practice insights from meta‐analysis?
Authors: Chatterjee Arka , Hillegass William B.
Published: November 2018

Key Points

Closure of patent foramen ovale (PFO) in embolic stroke of undetermined source (ESUS) reduces recurrent stroke compared with antiplatelet therapy in select patients but increases risk of atrial fibrillation.

Device closure is an attractive option for young patients with an anatomically higher risk PFO and imaging proven ESUS.

Benefit of PFO closure in ESUS compared with oral anticoagulation remains undefined.
Is the local guy, just a local guy?
Authors: Lemos Pedro A.
Published: November 2018

Key Points

The most important risk factors and preventive strategies for coronary atherosclerosis are systemic. However, the clinical manifestations of atherosclerotic disease frequently resemble a localized process, instead of a systemic one.

In this issue of CCI, Zhang and co‐workers described the association between the occurrence of stent failure and the changes in the 3D geometry of coronary segments induced by stent implantation.

The investigation of local modulators of coronary disease appears as a large and fertile field of future cardiovascular research.
BioResorbable scaffolds: Out of sight but not out of mind
Authors: Seth Ashok , Rastogi Vishal
Published: November 2018

Key Points

The article highlights the results of a new novel BioResorbable Scaffold in “real world” practice

Based on this, further design iterations could be reviewed for next generation BRS

Larger and longer‐term trials would be needed to define the safety and effectiveness of new BRS in daily clinical practice
Anthraquinones with Ionizable Sodium Sulfonate Groups as Renewable Cathode Materials for Sodium‐Ion Batteries
Authors: Zhu Limin , Liu Jingbo , Liu Ziqi , Xie Lingling , Cao Xiaoyu
Published: November 2018

In this study, the electrochemical performances of anthraquinone (C14H8O2) without modification, anthraquinone‐1‐sulfonic acid sodium (C14H7NaO5S) and anthraquinone‐1,5‐disulfonic acid disodium salts (C14H6Na2O8S2) as organic cathode materials for sodium‐ion batteries are reported for the first time. Ionizable sodium sulfonate functional groups lead to a significant enhancement of the structural stability of C14H8O2, yielding excellent cycle and rate performance. The C14H6Na2O8S2 and C14H7NaO5S electrodes exhibit initial discharge capacities of 195 and 209 mAh g−1, which are maintained at 131 and 93 mAh g−1, respectively, after 100 cycles at a current density of 30 mA g−1. Even at a high rate of 480 mA g−1, the initial discharge capacity of C14H6Na2O8S2 is 114 mAh g−1, indicating a high rate capability. Also, the results show that the carbonyl group is the Na+ storage location during charge/discharge. Owing to their superior electrochemical performance, these organic cathode materials demonstrate promise for use in environmentally friendly, sustainable sodium‐ion batteries.
The Chemistry of Nucleation: In Situ Pair Distribution Function Analysis of Secondary Building Units During UiO‐66 MOF Formation
Authors: Xu Hui , Sommer Sanna , Broge Nils Lau Nyborg , Gao Junkuo , Iversen Bo Brummerstedt
Published: November 2018

The concept of secondary building units (SBUs) is central to all science on metal‐organic frameworks (MOFs), and they are widely used to design new MOF materials. However, the presence of SBUs during MOF formation remains controversial, and the formation mechanism of MOFs remains unclear, due to limited information about the evolution of prenucleation cluster structures. Here in situ pair distribution function (PDF) analysis was used to probe UiO‐66 formation under solvothermal conditions. The expected SBU—a hexanuclear zirconium cluster—is present in the metal salt precursor solution. Addition of organic ligands results in a disordered structure with correlations up to 23 Å, resembling crystalline UiO‐66. Heating leads to fast cluster aggregation, and further growth and ordering results in the crystalline product. Thus, SBUs are present already at room temperature and act as building blocks for MOF formation. The proposed formation steps provide insight for further development of MOF synthesis.