bluuebunny/crossref_metadata_2025 huggingface dataset:
Conventional and microwave reactions of 1,3‐diaryl‐5,4‐enaminonitrile‐pyrazole derivative with expected antimicrobial and anticancer activities
Authors: Anwer Kurls E. , Sayed Galal H.
Published: March 2020

The present study illustrates conventional and microwave reactions of 5‐amino‐1,3‐diaryl‐pyrazole‐4‐carbonitrile derivative with phenacyl bromide under different conditions, hydrazine hydrate, hydroxylamine hydrochloride, tetrahydrofuran, phthalic anhydride, and cyanoacetic acid. The product of the latter reaction condensed with hydrazine and cyclohexanone to give the pyrazolotriazepine acetonitrile and cyclohexylidene derivatives. The new cyclohexylidene is used as key intermediate to synthesize some new spiro compounds. The behavior of the starting compound with benzaldehyde, ethylenediamine, phenylenediamine, sodium azide, 1‐amino‐2‐hydroxynaphthalene‐7‐sulphonic acid, diethylmalonate, terephthalaldehyde, acetyl chloride, and acetic anhydride were also investigated. The new compounds structures were established from spectroscopic data. Some of the new pyrazole derivatives showed antibacterial and anticancer activities.
RBCK1‐related disease: A rare multisystem disorder with polyglucosan storage, auto‐inflammation, recurrent infections, skeletal, and cardiac myopathy—Four additional patients and a review of the current literature
Authors: Phadke Rahul , Hedberg‐Oldfors Carola , Scalco Renata S. , Lowe David M. , Ashworth Michael , Novelli Marco , Vara Roshni , Merwick Aine , Amer Halima , Sofat Reecha , Sugarman Max , Jovanovic Ana , Roberts Mark , Nakou Vasiliki , King Andrew , Bodi Istvan , Jungbluth Heinz , Oldfors Anders , Murphy Elaine
Published: March 2020

In this article, we report four new patients, from three kindreds, with pathogenic variants in RBCK1 and a multisystem disorder characterised by widespread polyglucosan storage. We describe the clinical presentation of progressive skeletal and cardiac myopathy, combined immunodeficiencies and auto‐inflammation, illustrate in detail the histopathological findings in multiple tissue types, and report muscle MRI findings.
Meta‐Analysis of Efficacy of Rhubarb Combined With Early Enteral Nutrition for the Treatment of Severe Acute Pancreatitis
Authors: Chen Xinrong , Yang Kun , Jing Guanda , Yang Jie , Li Ka
Published: March 2020

Background

Whether to provide rhubarb combined with early enteral nutrition (rhubarb/EEN) to patients with severe acute pancreatitis (SAP) remains controversial. This study aimed to systematically explore the efficacy and safety of rhubarb/EEN in SAP patients.

Methods

We performed searches in EMBASE, PubMed, Medline, Cochrane Library, Chinese Biomedicine Literature Database (SinoMed), Chinese Scientific Journal Database (VIP), Chinese National Knowledge Infrastructure (CNKI), and Wanfang database to identify relevant literature comparing rhubarb/EEN with EEN for SAP.

Results

Eleven randomized controlled trials (724 patients) were included. Meta‐analysis showed significantly shorter length of hospital stay (days) (mean difference [MD], −4.49; 95% CI, −6.09 to −2.90; P < .00001), shorter length of intensive care unit stay (days) (MD, −2.82; 95% CI, −4.00 to −1.64; P < .00001), shorter length of severe abdominal pain (days) (MD, −2.20; 95% CI, −2.50 to −1.90; P < .00001), shorter length of abdominal distention (days) (MD, −2.31; 95% CI, −2.84 to −1.78; P < .00001), shorter length of abnormal bowel sounds (days) (MD, −0.98; 95% CI, −1.12 to −0.88; P < .00001), less hospitalization expenditure ($1422.75/¥ 10,000) (MD, −1.40; 95% CI, −1.23 to −0.73; P < .00001), and smaller Acute Physiology and Chronic Health Evaluation II scores (points) (MD, −2.18; 95% CI, −2.81 to −1.56; P < .00001) in the rhubarb/EEN group than in the EEN group. Compared with EEN, rhubarb/EEN group had lower levels of white blood cells (109/L) (MD, −2.77; 95% CI, −3.80 to −1.74; P < .00001), C‐reactive protein (mg/L) (MD, −10.71; 95% CI, −13.40 to −8.02; P < .00001), and interleukin‐6 (ng/L) (MD, −8.02; 95% CI, −11.38 to −4.65; P < .00001). However, there were no significant differences (P > .05) between the 2 groups in terms of mortality rate (%) (P = .40), infection rate (%) (P = .28), and incidence of multiple organ dysfunction syndrome (%) (P = .09), but the overall effective rate was higher in the rhubarb/EEN group (MD, 2.57; 95% CI, 1.22 to ≈5.42; P = .01).

Conclusions

Combination of EEN and rhubarb may improve the gastrointestinal function, inhibit systemic inflammation and disease severity, and enhance the efficacy of enteral nutrition, leading to better therapeutic effectiveness in SAP patients.
Effect of 6‐thioguanine, as an electrolyte additive, on the electrochemical behavior of an Al–air battery
Authors: Hou Changsheng , Chen Shixing , Wang Zuokai , Wang Guixiang , Dong Guojun
Published: March 2020

In this study, the electrochemical behavior of an Al–air battery is improved by mixing 6‐thioguanine into 4.0 M NaOH electrolyte. The electrochemical performance of the Al electrodes is analyzed using potentiodynamic polarization, potentiostatic oxidation, and electrochemical impedance spectroscopy. The surface morphology of the Al electrodes after discharging for 1,000 s is characterized using scanning electron microscopy coupled with X‐ray elemental mapping for Al, O, C, N, and S. Furthermore, the utilization efficiencies of these samples are also determined. The results show that the corrosion resistance of the Al electrodes initially increases and then decreases with an increase in 6‐thioguanine concentration. The presence of 6‐thioguanine enhances the corrosion resistance to the maximum, with a corrosion current density (Icorr) of 6.170 mA/cm2, and corrosion inhibition efficiency (η) of 36.56%, at 0.5 mM of 6‐thioguanine.
Effect of cold rolling on microstructure, corrosion and electrochemical response of the lean duplex stainless steel LDX 2101® by a correlative EBSD–SKPFM investigation
Authors: Fuertes Nuria , Pettersson Rachel
Published: March 2020

This study elucidates the effect of cold rolling on the microstructure, corrosion and electrochemical response of the lean duplex stainless steel LDX 2101®. With thickness reductions of 0%, 20% and 40%, three different specimens are investigated in terms of microstructure (electron backscattered diffraction [EBSD] and energy‐dispersive X‐ray spectroscopy [EDS]), corrosion properties (ASTM G150, ASTM G61 and field testing), passive film properties (X‐ray photoelectron spectroscopy) and electrochemical response (scanning Kelvin probe force microscopy [SKPFM]). It is shown that deformation of LDX 2101 leads to changes in the microstructure such as mechanical twinning and martensite formation. The combination of EBSD, EDS and SKPFM maps shows that the work function is clearly dependent on composition, deformation and local misorientation, but not on the crystallographic orientation of the grains in the microstructure. Zones with low work function are seen to have the highest pitting susceptibility, which includes deformed ferritic, martensitic phase and areas with a high concentration of dislocations such as grain boundaries and mechanical twins. The overall conclusion is that cold deformation up to a 40% thickness reduction has a significant influence on the microstructure, but a small impact on the corrosion resistance of LDX 2101.
An analysis of social media marketing strategy and performance in the context of fashion brands: The case of Taiwan
Authors: Wu Chih‐Wen , Guaita Martínez José Manuel , Martín Martín José María
Published: March 2020

This study examines the social media strategy and performance of fashion brands. Drawing upon the resource‐based view, the study explores the influence of entrepreneurial orientation, innovation orientation, and market orientation on social media strategy and performance. Analysis was conducted using data on 207 Taiwanese fashion brands. These data were collected from a mail survey. Structural equation modeling and fuzzy‐set qualitative comparative analysis were used to test the empirical relationships proposed in the research hypotheses. The results indicate that social media strategy affects performance; entrepreneurial orientation and innovation orientation affect social media strategy; entrepreneurial orientation positively affects performance; and innovation orientation and market orientation positively affect performance.
5‐amino‐2‐methylpyridinium hydrogen fumarate: An XRD and NMR crystallography analysis
Authors: Corlett Emily K. , Blade Helen , Hughes Leslie P. , Sidebottom Philip J. , Walker David , Walton Richard I. , Brown Steven P.
Published: March 2020

Single‐crystal X‐ray diffraction structures of the 5‐amino‐2‐methylpyridinium hydrogen fumarate salt have been solved at 150 and 300 K (CCDC 1952142 and 1952143). A base–acid–base–acid ring is formed through pyridinium‐carboxylate and amine‐carboxylate hydrogen bonds that hold together chains formed from hydrogen‐bonded hydrogen fumarate ions. 1H and 13C chemical shifts as well as 14N shifts that additionally depend on the quadrupolar interaction are determined by experimental magic angle spinning (MAS) solid‐state nuclear magnetic resonance (NMR) and gauge‐including projector‐augmented wave (GIPAW) calculation. Two‐dimensional homonuclear 1H‐1H double‐quantum (DQ) MAS and heteronuclear 1H‐13C and 14N‐1H spectra are presented. Only small differences of up to 0.1 and 0.6 ppm for 1H and 13C are observed between GIPAW calculations starting with the two structures solved at 150 and 300 K (after geometry optimisation of atomic positions, but not unit cell parameters). A comparison of GIPAW‐calculated 1H chemical shifts for isolated molecules and the full crystal structures is indicative of hydrogen bonding strength.
Quality control of uroflowmetry and urodynamic data from two large multicenter studies of male lower urinary tract symptoms
Authors: Aiello Martino , Jelski Joseph , Lewis Amanda , Worthington Jo , McDonald Charlotte , Abrams Paul , Gammie Andrew , Harding Chris , Biers Suzanne , Hashim Hashim , Lane J. Athene , Drake Marcus J.
Published: March 2020

Aim

The International Continence Society (ICS) has standardized quality control and interpretation of uroflowmetry and urodynamics. We evaluated traces from two large studies of male lower urinary tract symptoms (UPSTREAM and UNBLOCS) against ICS standards of urodynamic equipment and practice.

Methods

Ten percent of uroflowmetry and urodynamics traces were selected at random from hospital sites. A data capture template was designed from the ICS Fundamentals of Urodynamic Practice checklist. Two pretrained blinded assessors extracted the data, with a third assessor to arbitrate. Departmental records of calibration checks and equipment maintenance were scrutinized.

Results

Seven out of twenty‐five (28%) departments reported no calibration checks. Four sites (16%) could not provide annual service records. In 32 out of 296 (10.8%) uroflowmetry traces, findings were affected by artifact. One hundred ten urodynamic study traces were reviewed; in 11 records (10%), key pressure traces were incompletely displayed. In 30 (27.2%), reference zero was not set to atmospheric pressure. Resting pressures were outside the expected range for 36 (32.7%). Pressure drift was seen in 18 traces (16.4%). At pressure‐flow study commencement, permission to void was omitted in 15 (13.6%). Cough testing after voiding was done in 71.2%, but the resulting cough spikes were significantly different in 16.5%. Erroneous diagnosis of bladder outlet obstruction (BOO) was identified in six cases (5.5%).

Conclusions

Erroneous diagnosis of BOO is a serious error of interpretation, as it could lead to unnecessary surgery. Other errors of standardization, testing, and interpretation were identified with lower risk of adverse implications. Inconsistent documentation of service records mean equipment accuracy is uncertain.
Molecular Recognition by Zn(II)‐Capped Dynamic Foldamers
Authors: Eccles Natasha , della Sala Flavio , Le Bailly Bryden A. F. , Whitehead George F. S. , Clayden Jonathan , Webb Simon J.
Published: March 2020

Two α‐aminoisobutyric acid (Aib) foldamers bearing Zn(II)‐chelating N‐termini have been synthesized and compared with a reported Aib foldamer that has a bis(quinolinyl)/mono(pyridyl) cap (BQPA group). Replacement of the quinolinyl arms of the BQPA‐capped foldamer with pyridyl gave a BPPA‐capped foldamer, then further replacement of the linking pyridyl with a 1,2,3‐triazole gave a BPTA‐capped foldamer. Their ability to relay chiral information from carboxylate bound to Zn(II) at the N‐terminus to a glycinamide‐based NMR reporter of conformational preference at the C‐terminus was measured. The importance of the quinolinyl arms became readily apparent, as the foldamers with pyridyl arms were unable to report on the presence of chiral carboxylate in acetonitrile. Low solubility, X‐ray crystallography and 1H NMR spectroscopy suggested that interfoldamer interactions inhibited carboxylate binding. However changing solvent to methanol revealed that the end‐to‐end relay of chiral information could be observed for the Zn(II) complex of the BPTA‐capped foldamer at low temperature.
Structural considerations for charge‐enhanced Brønsted acid catalysts
Authors: Payne Curtis , Kass Steven R.
Published: March 2020

All three N‐methylated and N‐protonated hydroxypyridinium BArF4– salt isomers were synthesized and their hydrogen bond donating abilities were investigated. DFT and G4 theory computations along with IR spectroscopic measurements were found to be effective methods for predicting the catalytic activities of these O–H and N–H Brønsted acids. A UV‐vis titration approach for rapidly quantifying hydrogen bond donating ability revealed that carbon‐hydrogen bonds also can participate in electrostatic interactions, but the presence of multiple equilibrium complexes results in a limitation of this method. In the methylated series of hydroxypyridines, the ortho and para isomers displayed modest rate enhancements relative to the meta derivative. Protonation introduces a new acidic site and the ortho hydroxypyridinium ion salt is a significantly more active catalyst than all of the other species examined. This is indicative of bidentate activation by the N–H and O–H acidic sites, and suggests a new design strategy for improving charge‐enhanced catalysts.
Hyaluronic acid vinyl esters: A toolbox toward controlling mechanical properties of hydrogels for 3D microfabrication
Authors: Zerobin Elise , Markovic Marica , Tomášiková Zuzana , Qin Xiao‐Hua , Ret Davide , Steinbauer Patrick , Kitzmüller Jakob , Steiger Wolfgang , Gruber Peter , Ovsianikov Aleksandr , Liska Robert , Baudis Stefan
Published: March 2020

In this study, a thorough exploration of constitutional parameters of thiol‐ene photocrosslinkable hydrogels based on hyaluronic acid vinyl ester was conducted in order to decipher their impact on material properties. These constitutional parameters originated from the process of synthesis (macromer size and degree of substitution) and from the process of formulation (photoinitiator concentration, macromer content, and thiol‐to‐ene ratio). Various macromers were obtained with a broad variety of degrees of substitution. Photorheology measurements were performed in order to determine the influence of the structure parameters on photoreactivity and the physical properties of hydrogels. Final crosslink densities and photoreactivities dramatically increase with increasing number of functional groups, macromer concentrations as well as with photoinitiator concentration. Swellabilities of the hydrogels were determined as complementary reference values. Mass swelling ratios as well as mass loss increased with decreasing degree of substitution as a result of increased mesh size and hydrophilicity. Finally, hyaluronic acid vinyl ester formulations were used to encapsulate fluorescent‐labeled immortalized human adipose‐derived mesenchymal stem cells in 3D via UV and by high‐resolution two‐photon polymerization. Cell‐survival was successfully studied via confocal laser scanning microscopy during the course of 2 weeks.
Plasma medical oncology: Immunological interpretation of head and neck squamous cell carcinoma
Authors: Witzke Katharina , Seebauer Christian , Jesse Katja , Kwiatek Elisa , Berner Julia , Semmler Marie‐Luise , Boeckmann Lars , Emmert Steffen , Weltmann Klaus‐Dieter , Metelmann Hans‐Robert , Bekeschus Sander
Published: March 2020

The prognosis of patients suffering from advanced‐stage head and neck squamous cell carcinoma (HNSCC) remains poor. Medical gas plasma therapy receives growing attention as a novel anticancer modality. Our recent prospective observational study on HNSCC patients suffering from contaminated tumor ulcerations without lasting remission after first‐line anticancer therapy showed remarkable efficacy of gas plasma treatment, with the ulcerated tumor surface decreasing by up to 80%. However, tumor growth relapsed, and this biphasic response may be a consequence of immunological and molecular changes in the tumor microenvironment that could be caused by (a) immunosuppression, (b) tumor cell adaption, (c) loss of microbe‐induced immunostimulation, and/or (d) stromal cell adaption. These considerations may be vital for the design of clinical plasma trials in the future.
Implantable Neuroamplifers for Electrocorticography Using Flexible and Biocompatible Technology
Authors: Marcoleta Juan Pablo , Nogueira Waldo , Yoma Néstor Becerra , Wuth Jorge , Jakimovski Filip , Fuenzalida Victor M. , Doll Theodor
Published: March 2020

Brain signals such as electroencephalography (EEG) and electrocorticography (ECoG) are used to diagnose epilepsy. ECoG signals are small and therefore require large amplification while keeping the recording electronics small enough to adapt to the surface of the brain. Moreover, the components have to be of low power to reduce the risk of brain damage while recording the brain. Herein, a neuroamplifier that is integrated in an ECoG is described. The amplifier, in combination with a novel multiplexing system that reduces the number of required amplifiers and ensures the flexibility of the ECoG, achieves the desired signal‐to‐noise ratio while reducing power consumption. The feasibility of the proposed design is validated though electronic simulations for different input signals, analyzing the actual amplification achieved and the response times. Moreover the circuit is implemented and real measurements are provided validating the simulations.
Comparison of Strain Characteristics and Contact Resistances of Heavily Phosphorus‐Doped Si Formed by Phosphorus Implantation and In Situ Phosphorus‐Doped Si Epitaxial Growth
Authors: Ko Eunjung , Lee Juhee , Shin Hyunsu , Park Seran , Ko Daehong
Published: March 2020

As transistor sizes reduce, the effect of contact resistivity on power consumption increases. To reduce contact resistivity, heavily phosphorus‐doped Si grown via in situ phosphorus‐doped (ISPD) Si epitaxial growth is studied actively. Laser spike annealing to the heavily phosphorus implanted (IMP) layers is demonstrated to replace ISPD Si epitaxial growth process and phosphorus profiles and strain characteristics are evaluated. Regardless of the doping method, the phosphorus concentrations of both samples and their tensile strains are equivalent. After laser annealing, the metal‐silicidation is conducted to measure contact resistivity. The Ni‐silicide formed on IMP sample has 3D clusters inducing greater morphological degradation than ISPD samples. The contact resistivity of IMP sample measured using the circular transmission line model (CTLM) (1.2–8.3 × 10−8 Ω cm2) is similar to that of the ISPD sample (1.1–5.5 × 10−8 Ω cm2) after Ni‐silicidation of the ISPD layer. This study performs strain engineering by achieving low contact resistance at lower cost while applying strain using the IMP process rather than the epitaxial process.
Chainmail Catalyst of Fe3O4@C/CNTO‐Modified Celgard Separator with Low Metal Loading for High‐Performance Lithium–Sulfur Batteries
Authors: Du Jingguang , Ahmed Waqas , Xu Jie , Zhang Mingyuan , Zhang Zhiliang , Zhang Xinsheng , Niu Dongfang
Published: March 2020

Developing the conductive and catalytic composite interface is an efficient way to boost up the conversion of lithium polysulfide (LiPSs) that can effectively resolve the shuttle effect. Besides, achieving the high performance with low metal loading has practical significance for the commercialization of lithium–sulfur (Li−S) batteries. Herein, the chainmail catalyst of Fe3O4@C/CNTO was prepared by annealing the iron phthalocyanine (FePc)/oxidized carbon nanotubes (CNTO) precursor in which FePc was used as iron and carbon sources and CNTO was functionalized as oxygen source and catalyst support. The conductive composite catalyst with low metal loading (5.4 wt%) was applied into the coating layer of Celgard separator with duplex functions in trapping and catalyzing intercepted LiPSs for high‐performance Li−S batteries. This work can help us to understand the importance of conductive and catalytic composite interface for promotion of LiPSs conversion and also offer a more feasible synthesis method of electrocatalyst for other energy storage systems.
Distortion‐Free Sensing of Neural Activity Using Graphene Transistors
Authors: Garcia‐Cortadella Ramon , Masvidal‐Codina Eduard , De la Cruz Jose M. , Schäfer Nathan , Schwesig Gerrit , Jeschke Christoph , Martinez‐Aguilar Javier , Sanchez‐Vives Maria V. , Villa Rosa , Illa Xavi , Sirota Anton , Guimerà Anton , Garrido Jose A.
Published: March 2020

Graphene solution‐gated field‐effect transistors (g‐SGFETs) are promising sensing devices to transduce electrochemical potential signals in an electrolyte bath. However, distortion mechanisms in g‐SGFET, which can affect signals of large amplitude or high frequency, have not been evaluated. Here, a detailed characterization and modeling of the harmonic distortion and non‐ideal frequency response in g‐SGFETs is presented. This accurate description of the input–output relation of the g‐SGFETs allows to define the voltage‐ and frequency‐dependent transfer functions, which can be used to correct distortions in the transduced signals. The effect of signal distortion and its subsequent calibration are shown for different types of electrophysiological signals, spanning from large amplitude and low frequency cortical spreading depression events to low amplitude and high frequency action potentials. The thorough description of the distortion mechanisms presented in this article demonstrates that g‐SGFETs can be used as distortion‐free signal transducers not only for neural sensing, but also for a broader range of applications in which g‐SGFET sensors are used.
Enhancing the Formation of Porous Potato Starch by Combining α‐Amylase or Glucoamylase Digestion with Acid Hydrolysis
Authors: Gonzalez Ana , Wang Ya‐Jane
Published: March 2020

Granular porous starch has been prepared from A‐type starch, but not from B‐type starch, due, in part, to the smooth, dense surface of B‐type starch. This study prepares and characterizes acid‐hydrolyzed common corn (A‐type) and potato (B‐type) starches, followed by digestion with α‐amylase or glucoamylase. The results show that, compared to corn starch, potato starch is hydrolyzed faster by acid, whereas the degree of enzyme digestion varies with the starches and enzymes. The acid hydrolyzing conditions destabilize the crystalline lamellae and consequently increase the degree of binding and digestion in both enzymes, which result in the formation of the porous structure in the potato starch. A more defined porous structure is observed in the potato starch after the combination of extended acid hydrolysis and enzyme digestion. B‐type porous starch can be a better colonic delivery system compared to A‐type porous starch due to its more resistance to enzyme digestion.
The effects of three different microplastics on enzyme activities and microbial communities in soil
Authors: Yi Meiling , Zhou Shaohong , Zhang Lilan , Ding Shiyuan
Published: March 2020

Soils always receive microplastics (MPs) from plastic mulching, compost, and sewage irrigation, but the effects of MPs on soil environment remain largely unexplored. The objectives of this study were to investigate the effects of three MPs (membranous polyethylene (PE), fibrous polypropylene (PP), and microsphere PP) on enzyme activities and microbial community structure in one loamy and sandy soil. The concentration of microsphere PP (2 mg/g) was one‐tenth of those of the other two MPs (20 mg/g). The results showed that the effects of three MPs on urease, dehydrogenase, and alkaline phosphatase activities followed the order: fibrous PP > membranous PE > microsphere PP, membranous PE > microsphere PP > fibrous PP and fibrous PP > microsphere PP > membranous PE, respectively. Results from high‐throughput sequencing of 16S rRNA revealed that the membranous PE and fibrous PP raised the alpha diversities of the soil microbiota, whereas the diversity indexes of microbiota on MPs surfaces were significantly lower than those in the amended soils. MPs significantly altered the microbial community structure, especially for the enrichment of Acidobacteria and Bacteroidetes, the depletion of Deinococcus‐Thermus and Chloroflexi. Aeromicrobium, Streptomyces, Mycobacterium, Janibacter, Nocardia, Arthrobacter were prone to inhabit on the MPs surfaces.

Practitioner points

Three microplastics had different effects on soil enzyme activities.

Fibrous PP had a more persistent effect on microbial activity.

Membranous PE and fibrous PP raised the alpha diversities of soil microbiota.

The effects of membranous PE and fibrous PP on microbial communities were similar.

Distinct microbial communities were enriched on the surfaces of microplastics.
Online streaming feature selection with incremental feature grouping
Authors: Al Nuaimi Noura , Masud Mohammad M.
Published: March 2020

Today, the dimensionality of data is increasing in a massive way. Thus, traditional feature selection techniques are not directly applicable. Consequently, recent research has led to the development of a more efficient approach to the selection of features from a feature stream, known as streaming feature selection. Another active research area, related to feature selection, is feature grouping. Feature grouping selects relevant features by evaluating the hidden information of selected features. However, although feature grouping is a promising technique, it is not directly applicable to feature streams. In this paper, we propose a novel and efficient algorithm that uses online feature grouping, embedded within a new incremental technique, to select features from a feature stream. This technique groups similar features together; it assigns new incoming features to an existing group or creates a new group. To the best of our knowledge, this is the first approach that proposes the use of incremental feature grouping to perform feature selection from features. We have implemented this algorithm and evaluated it, using benchmark datasets, against state‐of‐the‐art streaming feature selection algorithms that use feature grouping or incremental selection techniques. The results show superior performance by the proposed technique through combining the online selection and grouping, in terms of prediction accuracy and running time.

This article is categorized under:

  Algorithmic Development > Spatial and Temporal Data Mining

  Technologies > Data Preprocessing

  Technologies > Classification

  Technologies > Machine Learning
Medicine: A Prescription for Medical Student Leadership Education
Authors: Schmidt John W. , Linenberger Stephen J.
Published: March 2020

This chapter proposes a medical school leadership curriculum that is context‐driven, dovetails seamlessly with the medical student experience, and goes beyond managerial and professional interests by developing purposeful physician‐leaders and focusing leadership knowledge on patient outcomes.
Two New Dinuclear MnII Cluster‐based Metal‐organic Frameworks: Syntheses, Crystal Structures, and Magnetic Properties
Authors: Fan Jing , Zhang Yan
Published: March 2020

Two new dinuclear MnII cluster‐based metal‐organic frameworks, namely [Mn2(L)(DMPU)3]n (1) and [Mn(L)0.5(4,4'‐bipy)0.5(H2O)]n (2) (H4L = biphenyl‐3,3',5,5'‐tetracarboxylic acid, DMPU = 1,3‐dimethyltetrahydropyrimidin‐2(1H)‐one, 4,4'‐bipy = 4,4'‐bipyridine), were solvothermally synthesized and characterized by single‐crystal X‐ray diffraction, powder X‐ray diffraction, and magnetic studies. Compound 1 crystallizes in the monoclinic P21/n space group and displays a 3D framework with 4‐connected crb/BCT‐type topology, and compound 2 crystallizes in the monoclinic C2/c space group and displays a 3D framework with (4,6)‐connected sqc422‐type topology. The magnetic studies of compounds 1 and 2 show the presence of weak antiferromagnetic interactions within the dinuclear MnII units.
Effects of Solvent and Reaction Time in Sonochemical Synthesis of Cadmium(II) Compounds and Use them as Template for Synthesis of Cadmium(II) Oxide Nano Structures
Authors: Souri Bagher , Rezvani Ali Reza , Abbasi Soheila , Hayati Payam , Janczak Jan
Published: March 2020

Abstract. A cadmium(II) zero‐dimensional supramolecular compound [Cd(L)2(I)2] (1), {L = 2‐picolylamine}, was fabricated by branch tube and sonochemical irradiation techniques. Regardless of the method utilized, the same crystallographic structure is obtained for the complex. To investigate the effects of reaction time and solvent on the creation of [Cd(L)2(I)2] (1) supramolecule compound, certain tests were designed and four specimens of 1 were fabricated through sonochemical process. Less reaction time led to the creation of smaller particles with mixed morphologies. To prepare cadmium(II) oxide micro‐crystals via calcination, four samples were utilized as new precursors. Micro‐ and nano‐sphere of cadmium(II) oxide could be fabricated from 1. The morphology and structure of micro‐ and nano‐crystals were identified by using Scanning Electron Microscopy (SEM), IR spectroscopy, and X‐ray powder diffraction (XRD).
Isolation of N‐Heterocyclic Carbene‐Stabilized Phosphorus and Arsenic Mononitride
Authors: Bockfeld Dirk , Tamm Matthias
Published: March 2020

Phosphorus mononitride (PN) and arsenic mononitride (AsN) species supported by two different N‐heterocyclic carbenes were prepared: The reaction of [(IDipp)NSiMe3] [IDipp = 1,3‐bis(2,6‐diisopropylphenyl)imidazolin‐2‐ylidene] with PCl3 or AsCl3 afforded the dichlorides [(IDipp)NECl2] (E = P, As) and, after the addition of IMes [IMes = 1,3‐bis(2,4,6‐trimethylphenyl)imidazolin‐2‐ylidene], the cationic chloro species [(IDipp)NE(Cl)(IMes)]Cl (E = P, As), which were reduced with potassium graphite (KC8) to yield the neutral compounds [(IMes)PN(IDipp)] and [(IMes)AsN(IDipp)], which exhibit the typical trans‐bent geometry of dicarbene‐dielement species in the solid state according to single‐crystal X‐ray diffraction.
A First Assessment of the Corrections for the Consistency of the IAU2000 and IAU2006 Precession-Nutation Models
Authors: Ferrándiz José M. , Koudsi Dhygham Al , Escapa Alberto , Belda Santiago , Modiri Sadegh , Heinkelmann Robert , Schuh Harald
Published: March 2020

The Earth precession-nutation model endorsed by resolutions of each the International Astronomical Union and the International Union of Geodesy and Geophysics is composed of two theories developed independently, namely IAU2006 precession and IAU2000A nutation. The IAU2006 precession was adopted to supersede the precession part of the IAU 2000A precession-nutation model and tried to get the new precession theory dynamically consistent with the IAU2000A nutation.

However, full consistency was not reached, and slight adjustments of the IAU2000A nutation amplitudes at the micro arcsecond level were required to ensure consistency. The first set of formulae for these corrections derived by Capitaine et al. (Astrophys 432(1):355–367, 2005), which was not included in IAU2006 but provided in some standards and software for computing nutations. Later, Escapa et al. showed that a few additional terms of the same order of magnitude have to be added to the 2005 expressions to get complete dynamical consistency between the official precession and nutation models. In 2018 Escapa and Capitaine made a joint review of the problem and proposed three alternative ways of nutation model and its parameters to achieve consistency to certain different extents, although no estimation of their respective effects could be worked out to illustrate the proposals. Here we present some preliminary results on the assessment of the effects of each of the three sets of corrections suggested by Escapa and Capitaine (Proceedings of the Journées, des Systémes de Référence et de la Rotation Terrestre: Furthering our Knowledge of Earth Rotation, Alicante, 2018) by testing them in conjunction with the conventional celestial pole offsets given in the IERS EOP14C04 time series.
Achievements of the First 4 Years of the International Geodynamics and Earth Tide Service (IGETS) 2015–2019
Authors: Boy Jean-Paul , Barriot Jean-Pierre , Förste Christoph , Voigt Christian , Wziontek Hartmut
Published: March 2020

We present the activities and improvements of the International Geodynamics and Earth Tide Service (IGETS) over the last four years. IGETS collects, archives and distributes long time series from geodynamic sensor, in particular superconducting gravimeter data currently from more than 40 stations and 60 different sensors. In addition to the raw 1-s and 1-min gravity and atmospheric pressure data (Level 1), IGETS produces end-user products on different levels. These include gravity and atmospheric pressure data corrected for major instrumental perturbations and ready for tidal analysis (Level 2). Since 2019, IGETS provides gravity residuals corrected for most geophysical contributions (Level 3) which can be used directly for geophysical applications without any expert knowledge in the processing of gravimetric time series.
Convergent momentum-space OPE and bootstrap equations in conformal field theory
Authors: Gillioz Marc , Lu Xiaochuan , Luty Markus A. , Mikaberidze Guram
Published: March 2020

Abstract

General principles of quantum field theory imply that there exists an operator product expansion (OPE) for Wightman functions in Minkowski momentum space that converges for arbitrary kinematics. This convergence is guaranteed to hold in the sense of a distribution, meaning that it holds for correlation functions smeared by smooth test functions. The conformal blocks for this OPE are conceptually extremely simple: they are products of 3-point functions. We construct the conformal blocks in 2-dimensional conformal field theory and show that the OPE in fact converges pointwise to an ordinary function in a specific kinematic region. Using microcausality, we also formulate a bootstrap equation directly in terms of momentum space Wightman functions.
On the Evolution of Regularized Dirac-Harmonic Maps from Closed Surfaces
Authors: Branding Volker
Published: March 2020

We study the evolution equations for a regularized version of Dirac-harmonic maps from closed Riemannian surfaces. We establish the existence of a global weak solution for the regularized problem, which is smooth away from finitely many singularities. Moreover, we discuss the convergence of the evolution equations and address the question if we can remove the regularization in the end.
Coiling of the Internal Carotid Artery is Associated with Hypertension in Patients Suspected of Stroke
Authors: van Rooij Josephus L. M. , Takx Richard A. P. , Velthuis Birgitta K. , Dankbaar Jan Willem , de Jong Pim A. ,   the DUST investigators
Published: March 2020

Purpose

The etiology of coiling (i.e. severe elongation) of the extracranial part of the internal carotid artery (ICA) is poorly understood with the proposed etiology being congenital, atherosclerotic or hypertension. The objective was to investigate the association of coiling with hypertension, carotid artery atherosclerosis and other cardiovascular risk factors.

Methods

A case control study was performed in patients suspected of stroke, with (cases) or without (controls) coiling of the ICA determined on compute tomography angiography (CTA). Baseline characteristics included age, gender, hypertension, diabetes, smoking and hypercholesterolemia. Coiling of the ICA and atherosclerotic plaque at the carotid bifurcation were assessed on CTA. Logistic regression analyses were conducted.

Results

Coiling was identified in 108 patients with a median age of 71 years. Cases were compared with 256 controls with a median age of 69 years. Hypertension was present in 63% of the patients with coiling compared to 51% in the control group. Univariable analysis showed that hypertension was significantly associated with coiling, with an odds ratio of 1.65 (95% confidence interval (CI) 1.04–2.61, p = 0.034). Multivariable analysis corrected for age and sex resulted in an odds ratio of 1.71 (95% CI 1.05–2.80, p = 0.032), while correcting for atherosclerotic plaque at the bifurcation yielded an odds ratio of 1.63 (95% CI 1.00–2.66, p = 0.049). Age and atherosclerotic plaque were not significantly associated with coiling.

Conclusion

The main finding of this study was the significant association of hypertension with coiling of the ICA and the absence of an association with age, plaques and atherosclerotic risk factors other than hypertension.
Acceptor substrate determines donor specificity of an aromatic prenyltransferase: expanding the biocatalytic potential of NphB
Authors: Johnson Bryce P. , Scull Erin M. , Dimas Dustin A. , Bavineni Tejaswi , Bandari Chandrasekhar , Batchev Andrea L. , Gardner Eric D. , Nimmo Susan L. , Singh Shanteri
Published: March 2020

Aromatic prenyltransferases are known for their extensive promiscuity toward aromatic acceptor substrates and their ability to form various carbon-carbon and carbon-heteroatom bonds. Of particular interest among the prenyltransferases is NphB, whose ability to geranylate cannabinoid precursors has been utilized in several in vivo and in vitro systems. It has therefore been established that prenyltransferases can be utilized as biocatalysts for the generation of useful compounds. However, recent observations of non-native alkyl-donor promiscuity among prenyltransferases indicate the role of NphB in biocatalysis could be expanded beyond geranylation reactions. Therefore, the goal of this study was to elucidate the donor promiscuity of NphB using different acceptor substrates. Herein, we report distinct donor profiles between NphB-catalyzed reactions involving the known substrate 1,6-dihydroxynaphthalene and an FDA-approved drug molecule sulfabenzamide. Furthermore, we report the first instance of regiospecific, NphB-catalyzed N-alkylation of sulfabenzamide using a library of non-native alkyl-donors, indicating the biocatalytic potential of NphB as a late-stage diversification tool.

Key Points

• NphB can utilize the antibacterial drug sulfabenzamide as an acceptor.

• The donor profile of NphB changes dramatically with the choice of acceptor.

• NphB performs a previously unknown regiospecific N-alkylation on sulfabenzamide.

• Prenyltransferases like NphB can be utilized as drug-alkylating biocatalysts.
Ice-rafted debris as a source of non-conservative behaviour for the εNd palaeotracer: insights from a simple model
Authors: Vogt-Vincent Noam , Lippold Jörg , Kaboth-Bahr Stefanie , Blaser Patrick
Published: March 2020

Neodymium isotopic composition (εNd) has enjoyed widespread use as a palaeotracer, principally because it behaves quasi-conservatively in the modern ocean. However, recent bottom water εNd reconstructions from the eastern North Atlantic are difficult to interpret under assumptions of conservative behaviour. The observation that this apparent departure from conservative behaviour increases with enhanced ice-rafted debris (IRD) fluxes has resulted in the suggestion that IRD leads to the overprinting of bottom water εNd through reversible scavenging. In this study, a simple water column model successfully reproduces εNd reconstructions from the eastern North Atlantic at the Last Glacial Maximum and Heinrich Stadial 1, and demonstrates that the changes in scavenging intensity required for good model-data fit is in good agreement with changes in the observed IRD flux. Although uncertainties in model parameters preclude a more definitive conclusion, the results indicate that the suggestion of IRD as a source of non-conservative behaviour in the εNd tracer is reasonable and that further research into the fundamental chemistry underlying the marine neodymium cycle is necessary to increase confidence in assumptions of conservative εNd behaviour in the past.
Bounds on the Objective Value of Feasible Roundings
Authors: Neumann Christoph , Stein Oliver , Sudermann-Merx Nathan
Published: March 2020

For mixed-integer linear and nonlinear optimization problems we study the objective value of feasible points which are constructed by the feasible rounding approaches from Neumann et al. (Comput. Optim. Appl. 72, 309–337, 2019; J. Optim. Theory Appl. 184, 433–465, 2020). We provide a-priori bounds on the deviation of such objective values from the optimal value and apply them to explain and quantify the positive effect of finer grids of integer feasible points on the performance of the feasible rounding approaches. Computational results for large scale knapsack problems illustrate our theoretical findings.
Analysis of inter-regional effects caused by the wide-area operation of the power grid in Japan: an implication for carbon pricing schemes
Authors: Nakano Satoshi , Washizu Ayu
Published: March 2020

In this research, we examine the socioeconomic impact of carbon pricing (CP) mechanism-related energy policies under the technical constraints of Japan. For this, we have created the Inter-Regional Input–Output Table for a Next Generation Energy System (IONGES) in 2030, considering these technical constraints. Namely, we created three Inter-Regional IONGESs with different assumptions for the wide-area operation of the power grid. The results show that the technical constraints of the power grid influence the interregional distribution of renewable energy. Top ten regional renewable energy sectors (TOP10), which has a large production scale, account for approximately 54% of renewable energy generation, which was found to be biased. From the viewpoint of consumers in each region, we analyzed the share of the electricity cost required to support their consumption. If the CP mechanism is implemented under the technical constraints of the current power grid, consumers in each region will be impacted unequally. However, it was found that such inequality will be solved under the wide-area operation of the power grid.
A nationwide survey on clinical practice patterns and bleeding complications of percutaneous native kidney biopsy in Japan
Authors:   Committee of Practical Guide for Kidney Biopsy 2019, Kawaguchi Takehiko , Nagasawsa Tasuku , Tsuruya Kazuhiko , Miura Kenichiro , Katsuno Takayuki , Morikawa Takashi , Ishikawa Eiji , Ogura Masao , Matsumura Hideki , Kurayama Ryota , Matsumoto Shinsuke , Marui Yuhji , Hara Shigeo , Maruyama Shoichi , Narita Ichiei , Okada Hirokazu , Ubara Yoshifumi
Published: March 2020

Background

Practice patterns and bleeding complications of percutaneous native kidney biopsy (PNKB) have not recently been investigated and the Japanese Society of Nephrology performed a nationwide questionnaire survey in 2018.

Methods

The survey consisted of nine sections about PNKB: (1) general indications; (2) indications for high-risk patients; (3) informed consent; (4) pre-biopsy evaluation; (5) procedures; (6) sedation; (7) post-biopsy hemostasis, bed rest, and examinations; (8) bleeding complications; and (9) specimen processing. A supplementary survey examined bleeding requiring transcatheter arterial embolization (TAE).

Results

Overall, 220 directors of facilities (nephrology facility [NF], 168; pediatric nephrology facility [PF], 52) completed the survey. Indications, procedures, and monitoring protocols varied across facilities. Median lengths of hospital stay were 5 days in NFs and 6 days in PFs. Gauge 14, 16, 18 needles were used in 5%, 56%, 33% in NFs and 0%, 63%, 64% in PFs. Mean limits of needle passes were 5 in NFs and 4 in PFs. The bed rest period was 16–24 h in 60% of NFs and 65% of PFs. Based on 17,342 PNKBs, incidence rates of macroscopic hematuria, erythrocyte transfusion, and TAE were 3.1% (NF, 2.8%; PF, 6.2%), 0.7% (NF, 0.8%; PF, 0%), and 0.2% (NF, 0.2%; PF, 0.06%), respectively. Forty-six percent of facilities processed specimens all for light microscopy, immunofluorescence, and electron microscopy, and 21% processed for light microscopy only. Timing of bleeding requiring TAE varied among PNKB cases.

Conclusion

Wide variations in practice patterns of PNKB existed among facilities, while PNKBs were performed as safely as previously reported.
Effect of B2O3 addition on mineralogical phases and leaching behavior of synthetic CaO–SiO2–MgO–Al2O3–CrOx slag
Authors: Lin Yong , Luo Qingyun , Yan Baijun , Fabritius Timo , Shu Qifeng
Published: March 2020

Boron oxide is frequently applied in modification of stainless steelmaking slag to mitigate the disintegration of slag. In this work, the effect of B2O3 on mineralogical phases and hexavalent chromium leaching behavior of synthetic CaO–SiO2–MgO–Al2O3–CrOx slag was investigated. Di-calcium silicate, merwinite, spinel, akermanite, and matrix phase were observed as main minerals in slags by scanning electron microscope (SEM) equipped with energy-dispersive spectrometry (EDS) and X-ray diffraction (XRD) techniques. It was found that 2% B2O3 addition is sufficient to eliminate the disintegration of synthetic slag by suppressing the phase transition to γ-Ca2SiO4. The size of spinel phase increases with increasing B2O3, which could be well interpreted by enhanced Ostwald ripening. The amount of Ca2SiO4 phase in slag was reduced by addition of B2O3; however, excess B2O3 (> 2%) addition would significantly increase chromium concentration and overall chromium distribution in Ca2SiO4 phase. Leaching results according to US-EPA-3060A method indicated that excess boron oxide addition (> 2%) leads to a significant increase of hexavalent chromium leaching concentrations and should be avoided for stabilizing stainless steel slag.
Pre-service teachers’ evidence-based reasoning during pedagogical problem-solving: better together?
Authors: Csanadi Andras , Kollar Ingo , Fischer Frank
Published: March 2020

This study investigates if collaboration and the level of heterogeneity between collaborating partners’ problem-solving scripts can influence the extent to which pre-service teachers engage in evidence-based reasoning when analyzing and solving pedagogical problem cases. We operationalized evidence-based reasoning through its content and process dimensions: (a) to what extent pre-service teachers refer to scientific theories or evidence of learning and instruction (content level) and (b) to what extent they engage in epistemic processes of scientific reasoning (process level) when solving pedagogical problems. Seventy-six pre-service teachers analyzed and solved a problem about an underachieving student either individually or in dyads. Compared with individuals, dyads of pre-service teachers referred less to scientific content, but engaged more in hypothesizing and evidence evaluation and less in generating solutions. A greater dyadic heterogeneity indicated less engagement in generating solutions. Thus, collaboration may be a useful means for engaging preservice teachers in analyzing pedagogical problems in a more reflective and evidence-based manner, but pre-service teachers may still need additional scaffolding to do it based on scientific theories and evidence. Furthermore, heterogeneous groups regarding the collaborating partners’ problem-solving scripts may require further instructional support to discuss potential solutions to the problem.