bluuebunny/crossref_metadata_2025 huggingface dataset:
Latent Nucleophiles in Lewis Base Catalyzed Enantioselective N‐Allylations of N‐Heterocycles
Authors: Zi You , Lange Markus , Schultz Constanze , Vilotijevic Ivan
Published: May 2019

Latent nucleophiles are compounds that are themselves not nucleophilic but can produce a strong nucleophile when activated. Such nucleophiles can expand the scope of Lewis base catalyzed reactions. As a proof of concept, we report that N‐silyl pyrroles, indoles, and carbazoles serve as latent N‐centered nucleophiles in substitution reactions of allylic fluorides catalyzed by Lewis bases. The reactions feature broad scopes for both reaction partners, excellent regioselectivities, and produce enantioenriched N‐allyl pyrroles, indoles, and carbazoles when chiral cinchona alkaloid catalysts are used.
Synthetic Haptens and Monoclonal Antibodies to the Cyanotoxin Anatoxin‐a
Authors: Quiñones‐Reyes Guillermo , Agulló Consuelo , Mercader Josep V. , Abad‐Somovilla Antonio , Abad‐Fuentes Antonio
Published: May 2019

Early warning systems for monitoring toxic events may benefit from the availability of monoclonal antibodies enabling the sensitive and specific detection of anatoxin‐a, a cyanotoxin involved in numerous cases of animal poisoning resulting from toxic algal blooms in freshwaters. Through the synthesis of three functionalized derivatives of anatoxin‐a, we have succeeded in generating the first‐ever reported immunoreagents (bioconjugates and antibodies) suitable for the development of immunoanalytical approaches aimed at rapid and onsite detection of this harmful cyanotoxin.
Synthesis and fabrication of high‐potent antimicrobial polymeric ultrathin coatings
Authors: Nagaraja Akshatha , Puttaiahgowda Yashoda Malgar , Devadiga Dheeraj
Published: May 2019

The development of antimicrobial coatings in various sectors is escalating nowadays. However, design, synthesis, and fabrication of simple antimicrobial polymer coatings with potent biocidal action against pathogenic microbes are necessary to emerge. The current article deals with fabrication of high efficient ultrathin coatings of synthesized polymer for controlling pathogenic bacteria and fungi. The article is intensified with simple synthesis, characterization, fabrication of ultrathin coatings and their antimicrobial studies. The polymer structure is elucidated by FTIR,1HNMR, and 13CNMR, and the thermal properties are explained by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The antimicrobial activity of a polymer and their ultrathin coatings against Escherichia coli, Staphylococcus aureus, tubercular‐variant Mycobacterium smegmatis, and Candida albicans are reported elaborately. The morphology of ultrathin coating and their interaction with microorganisms are studied using a scanning electron microscope and an atomic force microscope. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47893.
Investigation and improvement of the scorch behavior of silica‐filled solution styrene‐butadiene rubber compound
Authors: Wang Danling , Chen Sheng , Chen Li , Chen Boyu , Ren Fujun , Zhu Chenxi , Feng Jie
Published: May 2019

Effects of different silane coupling agents on scorch time of silica‐filled solution styrene‐butadiene rubber compounds were studied. The flocculation of silica at high temperature, which was characterized by rubber processing analyzer (RPA) and transmission electron microscope (TEM), has been proved to be an important factor affecting the scorch time of the compounds. In order to prolong the scorch time, the hybrid silane technology, that is, combining different silanes such as bis(triethoxysilypropyl)‐tetrasulfide (TESPT) and n‐octyltriethoxysilane (OTES) together, was developed to improve silica dispersion and suppress silica flocculation. The results showed that when the content of TESPT is fixed, the increase of OTES can effectively increase the scorch time due to the suppression of silica flocculation while not affecting the polymer crosslinking. This phenomenon is absent for the case where the OTES content is fixed, but the TESPT content is varied because the sulfur atoms in the TESPT molecules will also participate in the vulcanization process, leading to the decrease in scorch time. Through the present study, a connection between silica flocculation and scorch time has been built up, which is important for rubber composite processing. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2019,136, 47918.
Long time release of water soluble drug from hydrophilic nanofibrous material
Authors: Pan Nan , Qin Juanrong , Fan Yuwei , Li Zeke , Song Botao
Published: May 2019

In this study, mesoporous silica nanoparticles (MSNs) were embedded into the hydrophilic poly(vinyl alcohol) (PVA) nanofibrous mats to achieve sustained release of water soluble drug from hydrophilic nanofibrous mats. MSNs were successfully prepared based on a sol–gel method. Water soluble drug naproxen sodium was then loaded into the mesopores of the MSNs, and different amounts of the drug‐loaded MSNs were further incorporated into the fibers by the electrospinning process. Morphology of the nanofibrous mats was investigated, and it was found that all the fibers exhibited fibrous structure. Interestingly, lots of protrusions could be observed from the scanning electron microscopy images with high magnification, and numbers of the protrusions increased with the increasing of loading ratios of the MSNs from 5 to 15%. In addition, the wetting behaviors of the nanofibrous mats were also measured, and the water contact angles of all the mats were measured to be 0°. Finally, the drug release results indicated that all the PVA/MSNs composite nanofibrous mats showed an obviously prolonged drug release. The optimal loading ratio of the MSNs in the nanofibers was 10% due to the slowest drug release rate. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47922.
CFD and kinetic‐based modeling to optimize the sparger design of a large‐scale photobioreactor for scaling up of biofuel production
Authors: Ali Haider , Solsvik Jannike , Wagner Jonathan L. , Zhang Dongda , Hellgardt Klaus , Park Cheol Woo
Published: May 2019

Microalgal biofuels have not yet achieved wide‐spread commercialization, partially as a result of the complexities involved with designing and scaling up of their biosystems. The sparger design of a pilot‐scale photobioreactor (120 L) was optimized to enable the scale‐up of biofuel production. An integrated model coupling computational fluid dynamics and microalgal biofuel synthesis kinetics was used to simulate the biomass growth and novel biofuel production (i.e., bisabolene) in the photobioreactor. Bisabolene production from Chlamydomonas reinhardtii mutant was used as an example to test the proposed model. To select the optimal sparger configuration, a rigorous procedure was followed by examining the effects of sparger design parameters (number and diameter of sparger holes and gas flow rates) on spatially averaged bubble volume fraction, light intensity, friction velocity, power input, biomass concentration, and bisabolene production. The optimized sparger design increases the final biomass concentration by 18%, thereby facilitating the scaling up of biofuel production.
Virus clearance validation across continuous capture chromatography
Authors: Angelo James , Chollangi Srinivas , Müller‐Späth Thomas , Jusyte Simona , Xu Xuankuo , Ghose Sanchayita , Li Zhengjian
Published: May 2019

Multicolumn capture chromatography is gaining increased attention lately due to the significant economic and process advantages it offers compared with traditional batch mode chromatography. However, for wide adoption of this technology in clinical and commercial space, it requires scalable models for executing viral validation studies. In this study, viral validation studies were conducted under cGLP guidelines to assess retro‐ (X‐MuLV) and parvo‐virus (MVM) clearance across twin‐column continuous capture chromatography (CaptureSMB). A surrogate model was also developed using standard batch mode chromatography based on flow path modifications to mimic the loading strategy used in CaptureSMB. The results show that a steady state was achieved by the second cycle for both antibody binding and virus clearance and that the surrogate model using batch mode chromatography equipment provided impurity clearance that was comparable to that obtained during cyclical operation of CaptureSMB. Further, the log reduction values (LRVs) achieved during CaptureSMB were also comparable to the LRVs obtained using standard batch capture chromatography. This was expected since the mode of virus separation during protein A chromatography is primarily based on removal during the flow through and wash steps. Finally, this study also presents assessments on the resin cleaning strategy during continuous chromatography and how the duration of clean‐in‐place solution exposure impacts virus carryover.
Polycomb Repressive Complex 2: Modulator Development for Functional Regulation of a Multiprotein Complex by Using Structural Information
Authors: Tokodai Yasuaki , Yakushiji Fumika
Published: May 2019

Functional regulation of a protein complex is generally difficult because information of the target complex as a whole is limited. However, regulation of a protein complex is important for understanding complicated biological events in cells and therapeutic possibilities. This concept article introduces the potential for the functional regulation of a multiprotein complex, polycomb repressive complex 2 (PRC2), by developing chemical modulators. Functional regulatory mechanisms of PRC2 are described by using protein interaction information found through structural analyses. Subsequently, possibilities of novel chemical modulator development of PRC2 based on structural insights into the complex and related interactions are discussed.
Frustrated Interfaces Facilitate Dynamic Interactions between Native Client Proteins and Holdase Chaperones
Authors: He Lichun , Hiller Sebastian
Published: May 2019

Molecular chaperones are crucial for cellular life to ensure that all proteins obtain their right fold and functionality. Many chaperones promiscuously bind a wide spectrum of client proteins, ranging from nascent to quasi‐native and native proteins. Several recent studies have investigated, at atomic resolution, how chaperones interact with native proteins. Native proteins feature a wide variety of structural conformations, and therefore, a given chaperone cannot accomplish full surface complementarity to all of its client proteins. This limitation is circumvented by the recognition of frustrated regions on the client protein surface by the chaperone. In this interaction mode, the chaperone forms a multitude of transient local interactions with some segments of the client, whereas other parts are transiently not in favorable interactions. A permanent rearrangement of the client conformation on the chaperone occurs. Reconfiguration on the chaperone surface also gives the client a chance to fold into its correct, minimally frustrated conformation.
Targeted Heating of Enzyme Systems Based on Photothermal Materials
Authors: Wang Xuerui , Ou Gang , Zhou Ke , Wang Xiangqing , Wang Licheng , Zhang Xiaoyan , Feng Yi , Bai Yunpeng , Wu Hui , Xu Zhiping , Ge Jun
Published: May 2019

This study demonstrates that the enzymatic reaction rate can be increased significantly by targeted heating of the microenvironment around the enzyme, while maintaining the reaction system at environmental temperature. Enzyme molecules are covalently attached to the surface of Fe3O4@reduced graphite oxide (rGO). Under visible‐light irradiation, the reaction rate catalyzed by the enzyme–Fe3O4@rGO system is clearly enhanced relative to that of the free enzyme and a mixture of free enzyme and Fe3O4@rGO. This local heating mechanism contributes to promotion of the enzymatic reactions of the targeted heating of the enzyme (THE) system, which has been validated by using different enzymes, including lipase, glucose oxidase, and organophosphorus hydrolase. These results indicate that targeted heating of the catalytic centers has the same effect on speeding up reactions as that of traditional heating methods, which treat the whole reaction system. As an example, it is shown that the THE system promotes the sensitivity of an enzyme screen‐printed electrode by 14 times at room temperature, which implies that the THE system can be advantageous in improving enzyme efficiency, especially if heating the entire system is impossible or could lead to degradation of substrates or damage of components, such as in vitro bioanalysis of frangible molecules or in vivo diagnosis.
Trifluoromethylated Proline Surrogates as Part of “Pro–Pro” Turn‐Inducing Templates
Authors: Gadais Charlène , Van holsbeeck Kevin , Moors Samuel L. C. , Buyst Dieter , Fehér Krisztina , Van Hecke Kristof , Tourwé Dirk , Brigaud Thierry , Martin Charlotte , De Proft Frank , Pytkowicz Julien , Martins José C. , Chaume Grégory , Ballet Steven
Published: May 2019

Proline is often found as a turn inducer in peptide or protein domains. Exploitation of its restricted conformational freedom led to the development of the d‐Pro‐l‐Pro (corresponding to (R)‐Pro–(S)‐Pro) segment as a “templating” unit, frequently used in the design of β‐hairpin peptidomimetics, in which conformational stability is, however, inherently linked to the cis–trans isomerization of the prolyl amide bonds. In this context, the stereoelectronic properties of the CF3 group can aid in conformational control. Herein, the impact of α‐trifluoromethylated proline analogues is examined for the design of enhanced β‐turn inducers. A theoretical conformational study permitted the dipeptide (R)‐Pro–(R)‐TfmOxa (TfmOxa: 2‐trifluoromethyloxazolidine‐2‐carboxylic acid) to be selected as a template with an increased trans–cis rotational energy barrier. NMR spectroscopic analysis of the Ac‐(R)‐Pro–(R)‐TfmOxa–(S)‐Val‐OtBu β‐turn model, obtained through an original synthetic pathway, validated the prevalence of a major trans–trans conformer and indicated the presence of an internal hydrogen bond. Altogether, it was shown that the (R)‐Pro–(R)‐TfmOxa template fulfilled all crucial β‐turn‐inducer criteria.
Palladium‐Catalyzed Tunable Carbonylative Synthesis of Enones and Benzofulvenes
Authors: Peng Jin‐Bao , Wu Fu‐Peng , Spannenberg Anke , Wu Xiao‐Feng
Published: May 2019

A palladium‐catalyzed four‐component carbonylative coupling reaction involving aryl halides, internal alkynes, arylboronic acids, and CO has been developed for the first time. All‐carbon substituted α‐unsaturated ketones and benzofulvenes can be selectively obtained in a highly regio‐ and stereocontrolled manner. Using Cu(TFA)2 as the additive, a series of tetrasubstituted α‐unsaturated ketones were prepared in moderate to high yields. Using more acidic Lewis acid Cu(OTf)2 as the additive, multisubstituted benzofluvenes were synthesized in moderate yields. This efficient methodology involved the formation of three new C−C bonds, and provided a divergent method for the quick construction of multisubstituted α‐unsaturated ketones and benzofulvenes from easily available starting materials.
Modulation of Kinetic Pathways of Enzyme–Substrate Interaction in a Microfluidic Channel: Nanoscopic Water Dynamics as a Switch
Authors: Singh Priya , Mukherjee Dipanjan , Singha Subhankar , Das Ranjan , Pal Samir Kumar
Published: May 2019

Enzyme‐mediated catalysis is attributed to enzyme–substrate interactions, with models such as “induced fit” and “conformational selection” emphasizing the role of protein conformational transitions. The dynamic nature of the protein structure, thus, plays a crucial role in molecular recognition and substrate binding. As large‐scale protein motions are coupled to water motions, hydration dynamics play a key role in protein dynamics, and hence, in enzyme catalysis. Here, microfluidic techniques and time‐dependent fluorescence Stokes shift (TDFSS) measurements are employed to elucidate the role of nanoscopic water dynamics in the interaction of an enzyme, α‐Chymotrypsin (CHT), with a substrate, Ala‐Ala‐Phe‐7‐amido‐4‐methylcoumarin (AMC) in the cationic reverse micelles of benzylhexadecyldimethylammonium chloride (BHDC/benzene) and anionic reverse micelles of sodium bis(2‐ethylhexyl)sulfosuccinate (AOT/benzene). The kinetic pathways unraveled from the microfluidic setup are consistent with the “conformational selection” fit for the interaction of CHT with AMC in the cationic reverse micelles, whereas an “induced fit” mechanism is indicated for the anionic reverse micelles. In the cationic reverse micelles of BHDC, faster hydration dynamics (≈550 ps) aid the pathway of “conformational selection”, whereas in the anionic reverse micelles of AOT, the significantly slower dynamics of hydration (≈1600 ps) facilitate an “induced fit” mechanism for the formation of the final enzyme–substrate complex. The role of water dynamics in dictating the mechanism of enzyme–substrate interaction becomes further manifest in the neutral reverse micelles of Brij‐30 and Triton X‐100. In the former, the faster water dynamics aid the “conformational selection” pathway, whereas the significantly slower dynamics of water molecules in the latter are conducive to the “induced fit” mechanism in the enzyme–substrate interaction. Thus, nanoscopic water dynamics act as a switch in modulating the pathway of recognition of an enzyme (CHT) by the substrate (AMC) in reverse micelles.
Enantio‐ and Diastereoswitchable C−H Arylation of Methylene Groups in Cycloalkanes
Authors: Andrä Michal S. , Schifferer Lukas , Pollok Corina H. , Merten Christian , Gooßen Lukas J. , Yu Jin‐Quan
Published: May 2019

A complementary set of chiral N,N‐ligands enables the Pd‐catalyzed β‐C−H arylation of unbiased internal methylene groups in good yield and with high levels of enantio‐ and diastereoinduction. Both the dia‐ and enantioselectivity can be reversed, thus allowing the selective arylation of any of the four β‐C−H bonds in cycloalkanecarboxamides of various ring sizes. The method is applicable to a broad range of aryl iodides with electron‐withdrawing and ‐donating substituents in theo‐,m‐, orp‐position.
A novel phase field method for modeling the fracture of long bones
Authors: Shen Rilin , Waisman Haim , Yosibash Zohar , Dahan Gal
Published: May 2019

A proximal humerus fracture is an injury to the shoulder joint that necessitates medical attention. While it is one of the most common fracture injuries impacting the elder community and those who suffer from traumatic falls or forceful collisions, there are almost no validated computational methods that can accurately model these fractures. This could be due to the complex, inhomogeneous bone microstructure, complex geometries, and the limitations of current fracture mechanics methods.

In this paper, we develop a novel phase field method to investigate the proximal humerus fracture. To model the fracture in the inhomogeneous domain, we propose a power‐law relationship between bone mineral density and critical energy release rate. The method is validated by an in vitro experiment, in which a human humerus is constrained on both ends while subjected to compressive loads on its head, in the longitudinal direction, that lead to fracture at the anatomical neck. CT scans are employed to acquire the bone geometry and material parameters, from which detailed finite element meshes with inhomogeneous Young modulus distributions are generated.

The numerical method, implemented in a high performance computing environment, is used to quantitatively predict the complex 3D brittle fracture of the bone and is shown to be in good agreement with experimental observations. Furthermore, our findings show that the damage is initiated in the trabecular bone‐head and propagates outward towards the bone cortex. We conclude that the proposed phase field method is a promising approach to model bone fracture.
Nonadiabatic Dynamics Simulation Predict Intersystem Crossing in Nitroaromatic Molecules on a Picosecond Time Scale
Authors: Zobel J. Patrick , González Leticia
Published: May 2019

Previous time‐resolved spectroscopic experiments and static quantum‐chemical calculations attributed nitronaphthalene derivatives one of the fastest time scales for intersystem crossing within organic molecules, reaching the 100 fs mark. Nonadiabatic dynamics simulations on three nitronaphthalene derivatives challenge this view, showing that the experimentally observed ∼100 fs process corresponds to internal conversion in the singlet manifolds. Intersystem crossing, instead, takes place on a longer time scale of ∼1 ps. The dynamics simulations further reveal that the spin transitions occur via two distinct pathways with different contribution for the three systems, which are determined by electronic factors and the torsion of the nitro group. This study, therefore, indicates that the existence of sub‐picosecond intersystem crossing in other nitroaromatic molecules should be questioned.
Layered Confinement Reaction: Atomic‐level Dispersed Iron–Nitrogen Co‐Doped Ultrathin Carbon Nanosheets for CO2 Electroreduction
Authors: Tuo Jinqin , Zhu Yihua , Cheng Ling , Li Yuhang , Yang Xiaoling , Shen Jianhua , Li Chunzhong
Published: May 2019

High electrochemical over‐potential and low product selectivity are regarded as the main limitations of electroreduction of CO2. Here, we proposed a new strategy to synthesize metal porphyrin‐hybridized porous and ultra‐thin carbon nanosheets (MPPCN) by the confinement function of the layered template. The layered confinement reaction protects the coordination structure of metal and nitrogen atoms during subsequent high‐temperature treatment while ensuring the formation of ultra‐thin structures. This method effectively prevents the aggregation of metal atoms, so that the metal atoms exhibit a dispersed state of a single atomic level. MPPCN exhibit unexpected catalytic activity for electroreduction of CO2, and the catalytic reaction can be carried out at an over‐potential of 0.39 V. The faradaic efficiency of CO can reach 95.9 % at the potential of −0.7 V versus the reversible hydrogen electrode.
The ecological significance of extremely large flocks of birds
Authors: Møller Anders Pape , Laursen Karsten
Published: May 2019

Population size is generally limited by resource availability during and outside the breeding season. Therefore, maximum size of flocks may provide important information on population regulation and the influence of diet and trophic level on maximal degree of sociality. We hypothesized that (a) flock size should increase with nutrient availability; (b) flock size should decrease with latitude because productivity is higher at lower latitude; (c) aquatic habitats should have larger flocks than terrestrial habitats because the former are less accessible; (d) smaller species should have larger flocks because they require overall less food; (e) human‐impacted species that live in perturbed habitats should have smaller flocks than other species; (f) flock size should decrease with increasing trophic level because there is a reduction in biomass due to conversion at each trophic level; and (g) flocks of species depending on ancestral landscapes should have decreased in size in recent years due to human impact (e.g., land‐use). We obtained 1564 observations of flocks that exceeded 100,000 individuals in order to test the predictions listed above. Most effect sizes were small to medium accounting for 1%–9% of the variance, while large effects accounting for 25% or more were only found for total nitrogen used per km2 and area used for agriculture. Changes in large bird flocks were caused by habitat degradation and persecution, and temporal decline in size of large flocks revealed changes in nutrient use, reductions in nutrient cycling, and changes in flock size linked to trophic level.
RhIII‐Catalyzed Decarboxylative o‐Acylation of Arenes Bearing an Oxidizing Directing Group
Authors: Bera Suvankar , Chandrasekhar K. , Chatterjee Satadru , Killi Sunil Kumar , Sarkar Debabrata , Banerji Biswadip
Published: May 2019

Here in we report, rhodium(III)‐catalyzed decarboxylative acylation of arenes using α‐oxocarboxylic acids as acyl surrogate. In this strategy, O–NHAc group act as an autocleavable oxidizing directing group (ODGauto), thus giving rise to ortho‐acylated phenols in moderate to good yields. Mechanistic studies provided strong support for a kinetically relevant C–H bond activation. According to the best of our knowledge, this is the first report of Rhodium catalyzed decarboxylative acylation.
Chemistry of Polydopamine – Scope, Variation, and Limitation
Authors: Liebscher Jürgen
Published: May 2019

Polydopamine (PDA) is a polymer easily obtained by oxidation of dopamine. It is composed of indole and dopamine units in various oxidation states and to a lesser extent of pyrroles. It adheres to all type of surfaces even under water due to its abundant catechol moieties assisted by amino groups. This property together with a widespread reactivity to nucleophiles and electrophiles allowing linkage of a variety of entities renders PDA extremely interesting for various applications in biology, biomedicine, membranes, catalysis, materials and water purification. The field of PDA is violently developing. The present review gives an overview about the chemistry and properties of PDA and its analogues with the focus on recent publications. Their widespread applications are occasionally touched. Analogues are obtained by two strategies: post‐modification of PDA and oxidative polymerization of dopamine analogues. Scope and limitations of these strategies are worked out giving impulses for future research in the field.
Construction of novel silicon‐phosphorus linear polymers with DDSQ and DOPO derivatives for effective flame retardancy of PC/ABS
Authors: Song Wenpeng , Zhang Wang , Li Yonggang , Ma Huijuan , Lin Tao , Lu Cuifen , Nie Junqi , Yang Guichun , Chen Zuxing
Published: May 2019

Two kinds of novel silicon‐phosphorus linear polymers were synthesized by the hydrosilylation reaction of double‐decker‐shaped silsesquioxane (DDSQ) and 9,10‐dihydro‐9‐oxa‐10‐ phosphaphenanthrene‐10‐oxide (DOPO) derivatives and characterized using 1H NMR, 31P NMR, and 29Si NMR. Flame‐retardant polycarbonate/acrylonitric‐butadiene‐styrene (PC/ABS) blends were prepared with different contents of silicon‐phosphorus linear polymers. The flame‐retardant properties of silicon‐phosphorus linear polymers as well as the morphology were investigated in detail by using thermogravimetric analysis (TGA), limiting oxygen index (LOI), (Underwriters Laboratory) UL‐94, microscale combustion calorimetry (MCC), and scanning electron microscopy (SEM), respectively. The silicon‐phosphorus linear polymers containing DDSQ and DOPO units can synergistically improve the flame retardancy and thermal stability of PC/ABS blends. Flame‐retardant polymers with different linkers between DDSQ and phosphate units show comparable effect on the flame retardancy of PC/ABS.
Timing the “magical number seven”: Presentation rate and regularity affect verbal working memory performance
Authors: Schwartze Michael , Brown Rachel M. , Biau Emmanuel , Kotz Sonja A.
Published: May 2019

The informative value of time and temporal structure often remains neglected in cognitive assessments. However, next to information about stimulus identity we can exploit temporal ordering principles, such as regularity, periodicity, or grouping to generate predictions about the timing of future events. Such predictions may improve cognitive performance by optimising adaptation to dynamic stimuli. Here, we investigated the influence of temporal structure on verbal working memory by assessing immediate recall performance for aurally presented digit sequences (forward digit span) as a function of standard (1000 ms stimulus‐onset‐asynchronies, SOAs), short (700 ms), long (1300 ms) and mixed (700–1300 ms) stimulus timing during the presentation phase. Participant's digit spans were lower for short and mixed SOA presentation relative to standard SOAs. This confirms an impact of temporal structure on the classic “magical number seven,” suggesting that working memory performance can in part be regulated through the systematic application of temporal ordering principles.
Survivin a pivotal antiapoptotic protein in rheumatoid arthritis
Authors: Zafari Parisa , Rafiei Alireza , Esmaeili Seyed‐Alireza , Moonesi Mohammadreza , Taghadosi Mahdi
Published: May 2019

Rheumatoid arthritis (RA) is an autoimmune disease, pathologically characterized by lymphocyte infiltration of the synovial membrane that leads to chronic inflammation and progressive joint damage. RA develops as a result of increased cell infiltration and cell proliferation as well as impaired cell death. Activated cells in joints including lymphocytes and fibroblast‐like synoviocytes (FLS) survive for a long time as a consequence of compromised apoptosis, but the mechanism underlying cell survival in synovium remains to be firmly established. Inhibition of apoptosis by survivin, as a critical antiapoptotic protein, contributes to both the persistence of autoreactive T lymphocytes and tumor‐like phenotype of FLS in RA. In addition to the antiapoptotic role, survivin also has prognostic relevance in RA prodromal phase. Hence, this review provides an overview of the current knowledge regarding the involvement of survivin protein in the pathogenesis of RA.
Viral receptors for flaviviruses: Not only gatekeepers
Authors: Oliveira Lilian G , Peron Jean Pierre Schatzmann
Published: May 2019

Arboviruses have been a huge threat for human health since the discovery of yellow fever virus in 1901. Arboviruses are arthropod born viruses, mainly transmitted by mosquitoes and ticks, responsible for more than thousands of deaths annually. The Flavivirideae family is probably the most clinically relevant, as it is composed of very important agents, such as dengue, yellow fever, West Nile, Japanese encephalitis, and, recently, Zika virus. Intriguingly, despite their structural and genomic similarities, flaviviruses may cause conditions ranging from mild infections with fever, cutaneous rash, and headache, to very severe cases, such as hemorrhagic fever, encephalitis, Guillain-Barré syndrome, and microcephaly. These differences may greatly rely on viral burden, tissue tropism, and mechanisms of immune evasion that may depend on both viral and host genetic factors. Unfortunately, very little is known about the biology of these factors, and how they orchestrate these differences. In this context, viral structural proteins and host cellular receptors may have a great relevance, as their interaction dictates not only viral tissue tropism, but also a plethora on intracellular mechanisms that may greatly account for either failure or success of infection. A great number of viral receptors have been described so far, although there is still a huge gap in understanding their overall role during infection. Here we discuss some important aspects triggered after the interaction of flaviviruses and host membrane receptors, and how they change the overall outcome of the infection.
The impact of chemotherapy sequence on survival in node‐positive invasive lobular carcinoma
Authors: Tamirisa Nina , Williamson Hannah V. , Thomas Samantha M. , Westbrook Kelly E. , Greenup Rachel A. , Plichta Jennifer K. , Rosenberger Laura H. , Hyslop Terry , Hwang Eun‐Sil Shelley , Fayanju Oluwadamilola M.
Published: May 2019

Background and Objectives

We sought to evaluate the impact of chemotherapy sequence on survival by comparing node‐positive invasive lobular carcinoma (ILC) patients who received neoadjuvant (NACT) and adjuvant (ACT) chemotherapy.

Methods

cT1‐4c, cN1‐3 ILC patients in the National Cancer Data Base (2004‐2013) who underwent surgery and chemotherapy were divided into NACT and ACT cohorts. Kaplan‐Meier curves and Cox proportional hazards modeling were used to estimate unadjusted and adjusted overall survival (OS), respectively.

Results

Five thousand five hundred fifty‐one (35.6%) of 15 573 ILC patients treated with chemotherapy received NACT. NACT patients had similar rates of pT3/4 disease (26.6% vs 26.2%), nodal involvement (median 3 vs 4), and number of lymph nodes examined (median 13 vs 14) but higher rates of mastectomy (81.8% vs 74.5%, P < 0.001) vs ACT patients. 3.4% of NACT patients experienced pathologic complete response (pCR). Unadjusted 10‐year OS was worse for NACT vs ACT patients (65.1% vs 54.4%, log‐rank P < 0.001). After adjustment for known covariates, NACT continued to be associated with worse OS (hazard ratio [HR], 1.38; 95% confidence interval [CI], 1.25‐1.52).

Conclusions

In node‐positive ILC, NACT yielded low rates of pCR, was not associated with lower rates of mastectomy or less extensive axillary surgery, and was associated with worse survival vs ACT, suggesting limited benefit for these patients.
Impact of hypofractionated schemes in radiotherapy for locally advanced head and neck cancer patients
Authors: Franzese Ciro , Fogliata Antonella , Franceschini Davide , Navarria Pierina , Cozzi Luca , Tomatis Stefano , De Virgilio Armando , Spriano Giuseppe , Scorsetti Marta
Published: May 2019

Objective

To analyze two cohorts of locally advanced head and neck cancer (LAHNC) patients treated with two schedules of hypofractionated radiotherapy and 5 versus 3 mm clinical target volume–planning target volume (CTV‐PTV) margins.

Methods

145 patients were included. The patient cohort was divided into two groups. Group A included 97 patients treated with 69.96/54.45 grays (Gy) to the high‐risk and low‐risk volumes, respectively, in 33 fractions, with 5 mm margins. Group B included 48 patients treated with 66/54 Gy in 30 fractions using 3 mm margins. Toxicity was recorded according to the Common Toxicity Criteria version 3. Patient outcomes for locoregional control (LRC), disease‐free survival (DFS), and overall survival (OS) were determined.

Results

Median follow‐up was 26 months. In terms of toxicity, acute dysphagia worsened significantly (P = 0.003) in group B, whereas acute salivary toxicity tended to significance (P = 0.071). No significant late toxicity differences were recorded. Rates of LRC at 1 and 2 years were 90.1% ± 2.6% and 84.2% ± 3.4%, respectively, with superiority for group A (P = 0.045). The statistical significance remained for the low‐dose level (P = 0.007) but not for high dose (P = 0.110). Rates of DFS at 1 and 2 years were 84.9% ± 3.1% and 76.5% ± 3.9%, respectively, whereas rates of OS were 95.9% ± 1.8% and 91.6% ± 2.7%, respectively. No differences were observed between the two groups in terms of DFS (P = 0.270) and OS (P = 0.152).

Conclusion

The use of reduced CTV to PTV margins and dose reduction with hypofractionation schedule can improve the pattern of toxicity in LAHNC patients. This approach resulted in an increased rate of locoregional progression, particularly in low‐risk regions.

Level of Evidence

4

Laryngoscope, 130:E163–E170, 2020
Aberrant innominate artery: A possible hazard during total laryngectomy
Authors: Nijkamp Jamie , Jaafar Rohaizam Bin Japar , Postma Linda , Snoeijs Maarten , Qiu Shao Shan Shan , Tan Bing
Published: May 2019

Background

Surgical management in laryngeal carcinoma remains a challenge with countless unexpected complications. Great vessel anomalies such as anomaly of the innominate artery carry high risk of morbidity and mortality if not managed properly.

Methods

We present our first experience with an aberrant innominate artery during total laryngectomy which complicated the whole surgical procedure and tracheostoma placement.

Results

We decided to place a pectoralis major muscle flap to separate and cover up the aberrant vessel from the trachea and end‐stoma which ultimately did not lead to major complications postoperatively and postradiation therapy.

Conclusion

Aberrant innominate artery is an extremely rare entity and failure of recognizance can lead to hazardous complications. Preoperative angiography needs to be done if there are high suspicions of aberrant vessels in the operative field. Careful dissection of the head and neck region, and prompt decision making are mandatory to manage such cases.

Levels of Evidence

Case Report
Chronic inflammatory response in the rat lung to commonly used contrast agents for videofluoroscopy
Authors: Ueha Rumi , Nativ‐Zeltzer Nogah , Sato Taku , Goto Takao , Nito Takaharu , Tsunoda Koichi , Belafsky Peter C. , Yamasoba Tatsuya
Published: May 2019

Objectives

Contrast agents (CAs) are essential for upper gastrointestinal and videofluoroscopic swallow studies (VFSSs). Recently, we reported that small amounts of Ba aspiration caused severe acute lung inflammation in a rodent model. However, the underlying molecular biological mechanisms of chronic response to CA aspiration remain unclear. The aims of this study were to explore the underlying molecular biological mechanisms of the chronic response to three kinds of CA aspiration on the lung.

Study Design

Animal model.

Methods

Eight‐week‐old male Sprague Dawley rats were divided into five groups (n = 6, each group). Three groups underwent tracheal instillation of one of three CAs: barium sulfate (Ba), ionic iodinated contrast agent (ICA), and nonionic iodinated contrast agent (NICA). A sham group was instilled with air and a control group was instilled with saline. All animals were euthanized 30 days after treatment and histological and gene analyses were performed.

Results

No animal died after CA or sham/control aspiration. Ba particles remained after 30 days and caused histopathologic changes and inflammatory cell infiltration. Iodinated ICA and NICA did not result in perceptible histologic change. Expression of Tnf, an inflammatory cytokine was increased in only Ba aspirated rats (P = .0076). Other inflammatory cytokines and fibrosis‐related genes did not alter between groups.

Conclusion

Aspirated Ba particles did not clear from the lung within a month and caused mild chronic pulmonary inflammation. ICA and NICA did not cause any inflammatory responses in the lungs, suggesting that ICA and NICA may be safer CAs for VFSS than Ba.

Level of Evidence

NA
A narrative review of the epidemiology, diagnosis, and treatment of latent stress urinary incontinence
Authors: Edenfield Autumn , Patnam Radhika , Swift Steven
Published: May 2019

Aims

To review the current literature on the development of latent stress urinary incontinence (SUI) or SUI that occurs following pelvic organ prolapse therapy in patients who were continent prior to therapy. To make recommendations on how to best evaluate and manage patients with pelvic organ prolapse who are continent.

Methods

This is a narrative review using Google scholar and cross referencing identified manuscripts. We used the British Medical Journals grading of literature to assign letter grades to level of statements and recommendations.

Results

The literature suggest about 40% of women with advanced pelvic organ prolapse who are continent will develop SUI after surgery to correct their pelvic organ prolapse. Reduction cough stress testing can help identify those patients at risk to develop SUI with a PPV of 60%. Reduction cough stress testing is best done using large rectal swabs or scopettes. The literature on how to best manage patients with advanced pelvic organ prolapse and are continent to avoid latent SUI is mixed and the best recommendations are based on sound literature that is incomplete.

Conclusions

Understanding that latent SUI is a potential complication in any subject with advanced pelvic organ prolapse is necessary to pre‐operative counseling. Deciding on the best management strategy is not clear cut and therefore should involve patient input in the decision making process.
Extension of a simplified Baldwin–Lomax model to nonequilibrium turbulence: Model, analysis and algorithms
Authors: Rong Yao , Layton William , Zhao Haiyun
Published: May 2019

Complex turbulence not at statistical equilibrium is impossible to simulate using eddy viscosity models due to a backscatter. This research presents the way to correct the Baldwin–Lomax model for nonequilibrium effects and gives an analysis of the energy evolution in the corrected model. Furthermore, a finite element approximation of the corrected eddy model with first‐order and second‐order time discretization is also presented. A numerical test is given to support the theory.
How Footwear Is Assessed in Patient Reported Measures for People with Arthritis: A Scoping Review
Authors: Tehan Peta E. , Carroll Matthew , Dalbeth Nicola , Rome Keith
Published: May 2019

Background

In people with arthritis, footwear may influence foot function, pain, and mobility. In order to measure the effectiveness of interventions and patient experience, patient‐reported outcome measures (PROMs), and patient‐reported experience measures (PREMs) are frequently used. The aim of the scoping review was to identify footwear item content within foot‐specific PROMs and PREMs used in people with arthritis.

Method

Original studies that developed or validated a footwear‐inclusive PROM or PREM for use in people with arthritis affecting the foot were included. A comprehensive search was conducted using AMED, CINAHL, MEDLINE, Scopus, SPORTDiscus, and Ovid Emcare and Embase. A content analysis of extracted footwear content items was performed, by coding item content and grouping into broad themes, then further narrowing down and defining themes under five main categories.

Results

Nineteen articles satisfied inclusion criteria for this scoping exercise. Eleven PROMs met the inclusion criteria, five of which were designed for use in disease‐specific populations (rheumatoid arthritis and gout) and six designed for generic populations. Categories of the footwear specific content from the PROMs included pain, impairment and function, shoe‐specific characteristics, and psychosocial aspects. None of the included PROMs assessed footwear satisfaction. Eight PREMs relating to footwear experiences were identified. Seven of the PREMs were disease specific (inflammatory arthritis, osteoarthritis, rheumatoid arthritis, and systemic sclerosis) and one was generic. Content of the footwear‐related items of the included PREMs were categorized under pain, impairment and function, footwear satisfaction, and shoe‐specific characteristics. None of the PREM studies reported on psychosocial aspects of footwear.

Conclusions

Many different instruments have been used to measure the experience of footwear in patients with arthritis. However, no comprehensive tool that evaluates footwear and its relationship with pain, impairment, and disability; the psychosocial aspects of footwear; specific footwear features; and satisfaction is currently available for use in people with arthritis.

Level of Evidence

IV
Solid thermal explosion of autocatalytic material based on nonisothermal experiments: Multistage evaluations for 2,2′‐azobis(2‐methylpropionitrile) and 1,1′‐azobis(cyclohexanecarbonitrile)
Authors: Yu An‐Dong , Cao Chen‐Rui , Pan Xu‐Hai , Shu Chi‐Min , Wang Wei‐Jun
Published: May 2019

To achieve the thermal stability characteristics of azo compounds, a method for characterizing the kinetics of the reaction and decomposition for azo compounds based on nonisothermal calorimetric data was explored. Differential scanning calorimetry (DSC) was employed to analyze the thermal decomposition of two azo compounds, 2,2′‐azobis(2‐methylpropionitrile) and 1,1′‐azobis(cyclohexanecarbonitrile). DSC experiments were performed to acquire the exothermic peak temperature (Tp), exothermic final temperature (Tf), and heat of decomposition (△Hd). Corresponding thermokinetics were calculated using Flynn‐Wall‐Ozawa method. Moreover, data determined through DSC experiments were utilized to predict the self‐accelerating decomposition temperature, control temperature, and emergency temperature. A nonisothermal experiment was performed to investigate the runaway characteristics of azo compounds, the melting behavior that occurred in the decomposition process interfered with thermal analysis. Through dividing the reaction into several stages, multistage evaluations were carried out in the process of our study. During the thermal explosion simulation, the actual packing parameter of 25.0 kg was applied to ensure that the simulation results were more practical. Thermal safety parameters acquired from the simulation results can provide information on loss prevention and facilitated the establishment of an emergency relief system.

Highlights

The decomposition process was divided into several stages and considered melting behavior.

A green method contributes to intrinsic safety design.

Solid thermal explosion was simulated.
Decentralized adaptive consensus control for discrete‐time heterogeneous semiparametric multiagent systems
Authors: Li Shan , Ma Hongbin
Published: May 2019

Different from the consensus control of traditional multiagent systems, this paper studies the decentralized adaptive consensus control for discrete‐time heterogeneous hidden leader‐following semiparametric multiagent system, in which the dynamic equation of each agent has both parametric uncertainties and nonparametric uncertainties. In the considered system, there is a hidden leader agent who can receive the reference signal, but it can only affect the states of those agents who are in its neighborhood. For other following agents, they do not know the leader's existence or the reference signal, and they can only receive information from their neighbors. Our goal is to design decentralized adaptive controllers to make sure that all agents can track the reference signal, and the closed‐loop system achieves consensus in the presence of mutual coupling relations. Due to the existence of both parametric and nonparametric uncertainties in the system, we need to estimate them separately. For the parametric part, we propose a novel dead zone with threshold converging to zero to modify the traditional gradient update law, while for the nonparametric part, we introduce an auxiliary variable including both two uncertainties to facilitate the nonparametric uncertainties compensation. Based on the certainty equivalence principle in adaptive control theory, the decentralized adaptive controller is designed for each agent to make sure that all of them can track the reference signal. Finally, under the proposed control protocol, strict mathematical proofs are given by using Lyapunov theory; then, simulation results are provided to demonstrate the effectiveness of proposed decentralized adaptive controllers.
Electrospun Carbon Nanofiber Sprinkled with Co3O4 as an Efficient Electrocatalyst for Oxygen Reduction Reaction in Alkaline Medium
Authors: Selvakumar Karuppiah , Ulaganathan Mani , Senthil Kumar Sakkarapalayam Murugesan , Thangamuthu Rangasamy , Periasamy Padikkasu , Ragupathy Pitchai
Published: May 2019

Design and development of an efficient and earth abundant electrocatalyst for improving the kinetics of oxygen reduction reaction (ORR) is considered as important task especially in renewable energy sector and energy‐intensive appliances. In particular, developing a low cost, environmental benign, robust and stable ORR catalyst still remains a challenging task due to its sluggish kinetics. Here in this work we developed a simple and environmentally green electro‐spinning technique for decoration of cobalt oxides (Co3O4) on polyacrylonitrile (PAN) fibers to generate a hybrid nanostructure of carbon nanofiber‐ Co3O4 (CNF‐ Co3O4) during calcinations and employed resultant electrocatalyst towards ORR. The CNF provided active surface to seed as well an anchoring spot for nanocrystals and act as a conducting network. The resulting CNF‐Co3O4 hybrid displayed a supeior ORR current density that surpassed bare CNF and occurred via a 4 electron direct reduction pathway. It may due to the as formed heterogeneous interface during the decoration of Co3O4 on CNF leads to enhanced conductivity and thereby decreases ORR overpotential as well as enhanced reaction rate at CNF‐Co3O4 surface.