bluuebunny/crossref_metadata_2025 huggingface dataset:
Chiral Recognition on Bare Gold Surfaces by Quartz Crystal Microbalance
Authors: Xiao Xiangyun , Chen Chao , Zhang Yehao , Kong Huihui , An Rong , Li Shuang , Liu Wei , Ji Qingmin
Published: September 2021

Quartz crystal microbalance (QCM) is one of the powerful tools for the studies of molecular recognition and chiral discrimination. Its efficiency mainly relies on the design of the functional sensitive layer on the electrode surface. However, the organic sensitive layer may easily cause dissipation of oscillation or detachment and weaken the signal transfer during the molecular recognition processes. In this work, we reveal for the first time that the bare metal surface without the organic selector layer has the capability for chiral recognition in the QCM system. During the adsorption of various chiral amino acids, relatively higher selectivity of D‐enantiomers on gold (Au) surface was shown by the QCM detection. Based on analyses of the surface crystalline structure and density functional theory calculations, we demonstrate that the chiral nature of Au surface plays an important role in the selective binding of specific D‐amino acids. These results may open new insights on chiral detection by QCM system. It will also promote the construction of novel chiral sensing systems with both efficient detection and separation capability.
Stabilization of Reactive Nitrene by Silylenes without Using a Reducing Metal
Authors: Ding Yi , Sarkar Samir Kumar , Nazish Mohd , Muhammed Shahila , Lüert Daniel , Ruth Paul Niklas , Legendre Christina M. , Herbst‐Irmer Regine , Parameswaran Pattiyil , Stalke Dietmar , Yang Zhi , Roesky Herbert W.
Published: September 2021

Herein, we report the stabilization of nitrene reagents as the source of a nitrogen atom to synthesize nitrogen‐incorporated R1LSi‐N←SiLR2 (1) [L=PhC(NtBu)2; R1=NTMS2, R2=NTMS]. Compound 1 is synthesized by reacting LSi(I)‐SiIL with 3.1 equivalents of Me3SiN3 at low temperature to afford a triene‐like structural framework. Whereas the reaction of the LSi(I)‐SiIL with 2.1 equivalents of Me3SiN3 at room temperature produced silaimine 2 with a central four‐membered Si2N2 ring which is accompanied by a silylene LSi and a cleaved silylene fragment. 1 further reacts with AgOTf at room temperature to yield compound 3 which shows coordination of nitrene to silver with the triflate salt. The compounds 1 and 2 were fully characterized by NMR, mass spectrometry, and X‐ray crystallographic analysis. The quantum mechanical calculations reveal that compounds 1 and 2 have dicoordinated monovalent N atoms having two active lone pairs of electrons. These lone pairs are stabilized by hyperconjugative interactions.
On‐Surface Synthesis of a Dicationic Diazahexabenzocoronene Derivative on the Au(111) Surface
Authors: Biswas Kalyan , Urgel José I. , Xu Kun , Ma Ji , Sánchez‐Grande Ana , Mutombo Pingo , Gallardo Aurelio , Lauwaet Koen , Mallada Benjamin , de la Torre Bruno , Matěj Adam , Gallego José M. , Miranda Rodolfo , Jelínek Pavel , Feng Xinliang , Écija David
Published: September 2021

The atomically precise control over the size, shape and structure of nanographenes (NGs) or the introduction of heteroatom dopants into their sp2‐carbon lattice confer them valuable electronic, optical and magnetic properties. Herein, we report on the design and synthesis of a hexabenzocoronene derivative embedded with graphitic nitrogen in its honeycomb lattice, achieved via on‐surface assisted cyclodehydrogenation on the Au(111) surface. Combined scanning tunnelling microscopy/spectroscopy and non‐contact atomic force microscopy investigations unveil the chemical and electronic structures of the obtained dicationic NG. Kelvin probe force microscopy measurements reveal a considerable variation of the local contact potential difference toward lower values with respect to the gold surface, indicative of its positive net charge. Altogether, we introduce the concept of cationic nitrogen doping of NGs on surfaces, opening new avenues for the design of novel carbon nanostructures.
Block Copolymers Based on Ethylene and Methacrylates Using a Combination of Catalytic Chain Transfer Polymerisation (CCTP) and Radical Polymerisation
Authors: Baffie Florian , Patias Georgios , Shegiwal Ataulla , Brunel Fabrice , Monteil Vincent , Verrieux Ludmilla , Perrin Lionel , Haddleton David M. , D'Agosto Franck
Published: September 2021

Two scalable polymerisation methods are used in combination for the synthesis of ethylene and methacrylate block copolymers. ω‐Unsaturated methacrylic oligomers (MMAn) produced by catalytic chain transfer (co)polymerisation (CCTP) of methyl methacrylate (MMA) and methacrylic acid (MAA) are used as reagents in the radical polymerisation of ethylene (E) in dimethyl carbonate solvent under relatively mild conditions (80 bar, 70 °C). Kinetic measurements and analyses of the produced copolymers by size exclusion chromatography (SEC) and a combination of nuclear magnetic resonance (NMR) techniques indicate that MMAn is involved in a degradative chain transfer process resulting in the formation of (MMA)n‐b‐PE block copolymers. Molecular modelling performed by DFT supports the overall reactivity scheme and observed selectivities. The effect of MMAn molar mass and composition is also studied. The block copolymers were characterised by differential scanning calorimetry (DSC) and their bulk behaviour studied by SAXS/WAXS analysis.
Relationship between microstructure evolution and properties enhancement of carbon nanotubes‐filled polybutylene terephthalate/polypropylene blends induced by thermal annealing
Authors: Shang Mengyao , Gao Zhuyi , Cheng Henglun , Wu Chinan , Shentu Baoqing
Published: September 2021

Thermal annealing induced microstructure evolution and properties enhancement of polybutylene terephthalate/polypropylene/carbon nanotubes (PBT/PP/CNTs) nanocomposites was methodically investigated. The electrical conductive PBT/PP/CNTs nanocomposites with a low percolation threshold were obtained by simple melt blending due to the selective location of the CNTs in PBT phase and the formation of the double percolation structure. Thermal annealing further remarkably decreased the volume resistivity of the nanocomposites, with the maximum reduction of seven orders of magnitude. Scanning electron microscope observation and rheology tests demonstrated that the relatively large CNTs agglomerates were redistributed to build more homogeneous CNTs networks after annealing. The phase coalescence during annealing promoted the formation of the more perfect co‐continuous structure. These phenomena helped to enhance the electrical conductivity of the nanocomposites. Flexural properties of the nanocomposites were also enhanced after annealing, which might be due to the more effective stress transfer between the polymer and CNTs induced by the reconstructed CNTs networks. The nanocomposites obtained in this study possess excellent electrical and mechanical properties, which can be applied to the fields of sensors, electromagnetic interference shielding, anti‐static materials, and so forth.
Identification of additional young nearby runaway stars based on Gaia data release 2 observations and the lithium test
Authors: Bischoff Richard , Mugrauer Markus , Torres Guillermo , Geymeier Michael , Neuhäuser Ralph , Stenglein Wolfgang , Michel Kai‐Uwe
Published: September 2021

Runaway stars are characterized by their remarkably high space velocities, and the study of their formation mechanisms has attracted considerable interest. Young, nearby runaway stars are the most favorable for identifying their place of origin, and for searching for possible associated objects such as neutron stars. Usually, the research field of runaway stars focuses on O‐ and B‐type stars, because these objects are better detectable at larger distances than late‐type stars. Early‐type runaway stars have the advantage that they evolve faster and can therefore better be confirmed to be young. In contrast to this, the catalog of Young runaway stars within 3 kpc by Tetzlaff, N., Neuhäuser, R., & Hohle, M. M. (2011, MNRAS, 410(1), 190–200) contains also stars of spectral type A and later. The objects in this catalog were originally classified as young ( Myr) runaway stars by using Hipparcos data to estimate the ages from their location in the Hertzsprung‐Russell diagram and evolutionary models. In this article, we redetermine and/or constrain their ages not only by using the more precise second data release of the Gaia mission, but also by measuring the equivalent width of the lithium (6,708 Å) line, which is a youth indicator. Therefore, we searched for lithium absorption in the spectra of 51 target stars, taken at the University Observatory Jena between March and September 2020 with the Échelle spectrograph FLECHAS, and within additional TRES‐spectra from the Fred L. Whipple Observatory. The main part of this campaign with its 308 reduced spectra, accessible at VizieR, was already published. In this work, which is the continuation and completion of the in 2015 initiated observing campaign, we found three additional young runaway star candidates.
Identification of colon tumor marker NKD1 via integrated bioinformatics analysis and experimental validation
Authors: Wang Yue , Yang Chunxia , Li Wenjing , Shen Ying , Deng Jianzhong , Lu Wenbin , Jin Jianhua , Liu Yongping , Liu Qian
Published: September 2021

Background

Colorectal cancer is an important death‐related disease in the worldwide. However, specific colon cancer tumor markers currently used for diagnosis and treatment are few. The purpose of this study is to screen the potential colon cancer markers by bioinformatics and verify the results with experiments.

Methods

Gene expression data were downloaded from two different databases: TCGA database and GEO datasets, which were then analyzed by two different methods (difference analysis and WGCNA method). Venn and PPI analysis obtained the potential core genes, which were then performed the GO enrichment and KEGG pathway analysis. Expressions levels of NKD1 in colon carcinoma tissues were further confirmed by immunohistochemical staining and western blot assays. Moreover, the function was measured by MTT, clone formation, and tumor transplantation experiments. Importantly, co‐immunoprecipitation, immunofluorescence, and protein stability assays were further performed to explore the underlying mechanism of NKD1 promoting cell proliferation.

Results

Nine potential core genes highly expressed in colon cancer samples were screened out by bioinformatics analysis. NKD1, one of the hub genes, highly expressed in the colon carcinoma tissues could enhance the proliferation of colon cancer cells. Mechanism research demonstrated that NKD1 was essential for the combination between Wnt signalosome (DVL) and β‐catenin, and that NKD1 knockout remarkably decreased the β‐catenin expression. Immunofluorescence assays further implied that NKD1 knockout significantly inhibited β‐catenin nuclear accumulation. Importantly, the stability of β‐catenin proteins was maintained by NKD1 in the colon cancer cells.

Conclusion

We believe that NKD1 well expressed in the colorectal carcinoma tissues can enhance the proliferation of colon cancer cells. Furthermore, the functions that NKD1 may have in colon cancer cells should be different from that NKD1 has played in the zebrafish. Thus, NKD1 could be a specific colorectal cancer marker.
The critical role of mesenchymal stromal/stem cell therapy in COVID‐19 patients: An updated review
Authors: Ebrahimi Mohsen , Rad Mohammad Taha Saadati , Zebardast Arghavan , Ayyasi Mitra , Goodarzi Golnaz , Tehrani Sadra Samavarchi
Published: September 2021

New coronavirus disease 2019 (COVID‐19), as a pandemic disaster, has drawn the attention of researchers in various fields to discover suitable therapeutic approaches for the management of COVID‐19 patients. Currently, there are many worries about the rapid spread of COVID‐19; there is no approved treatment for this infectious disease, despite many efforts to develop therapeutic procedures for COVID‐19. Emerging evidence shows that mesenchymal stromal/stem cell (MSC) therapy can be a suitable option for the management of COVID‐19. These cells have many biological features (including the potential of differentiation, high safety and effectiveness, secretion of trophic factors and immunoregulatory features) that make them suitable for the treatment of various diseases. However, some studies have questioned the positive role of MSC therapy in the treatment of COVID‐19. Accordingly, in this paper, we will focus on the therapeutic impacts of MSCs and their critical role in cytokine storm of COVID‐19 patients.
Identification and Composition of Clasper Scent Gland Components of the Butterfly Heliconius erato and Its Relation to Mimicry
Authors: Ehlers Stephanie , Szczerbowski Daiane , Harig Tim , Stell Matthew , Hötling Susan , Darragh Kathy , Jiggins Chris D. , Schulz Stefan
Published: September 2021

The butterfly Heliconius erato occurs in various mimetic morphs. The male clasper scent gland releases an anti‐aphrodisiac pheromone and additionally contains a complex mixture of up to 350 components, varying between individuals. In 114 samples of five different mimicry groups and their hybrids 750 different compounds were detected by gas chromatography/mass spectrometry (GC/MS). Many unknown components occurred, which were identified using their mass spectra, gas chromatography/infrared spectroscopy (GC/IR)‐analyses, derivatization, and synthesis. Key compounds proved to be various esters of 3‐oxohexan‐1‐ol and (Z)‐3‐hexen‐1‐ol with (S)‐2,3‐dihydrofarnesoic acid, accompanied by a large variety of other esters with longer terpene acids, fatty acids, and various alcohols. In addition, linear terpenes with up to seven uniformly connected isoprene units occur, e. g. farnesylfarnesol. A large number of the compounds have not been reported before from nature. Discriminant analyses of principal components of the gland contents showed that the iridescent mimicry group differs strongly from the other, mostly also separated, mimicry groups. Comparison with data from other species indicated that Heliconius recruits different biosynthetic pathways in a species‐specific manner for semiochemical formation.
Thiophene‐Based Dual Modulators of Aβ and Tau Aggregation
Authors: Ramesh Madhu , Acharya Anand , Murugan N. Arul , Ila Hiriyakkanavar , Govindaraju Thimmaiah
Published: September 2021

Alzheimer's disease is characterized by the accumulation of amyloid beta (Aβ) and Tau aggregates in the brain, which induces various pathological events resulting in neurodegeneration. There have been continuous efforts to develop modulators of the Aβ and Tau aggregation process to halt or modify disease progression. A few small‐molecule‐based inhibitors that target both Aβ and Tau pathology have been reported. Here, we report the screening of a targeted library of small molecules to modulate Aβ and Tau aggregation together with their in vitro, in silico and cellular studies. In vitro ThT fluorescence assay, dot blot assay, gel electrophoresis and transmission electron microscopy (TEM) results have shown that thiophene‐based lead molecules effectively modulate Aβ aggregation and inhibit Tau aggregation. In silico studies performed by employing molecular docking, molecular dynamics and binding‐free energy calculations have helped in understanding the mechanism of interaction of the lead thiophene compounds with Aβ and Tau fibril targets. In cellulo studies revealed that the lead candidate is biocompatible and effectively ameliorates neuronal cells from Aβ and Tau‐mediated amyloid toxicity.
Protein Design with Fluoroprolines: 4,4‐Difluoroproline Does Not Eliminate the Rate‐Limiting Step of Thioredoxin Folding
Authors: O' Loughlin Jennie , Napolitano Silvia , Rubini Marina
Published: September 2021

C4‐substituted fluoroprolines (4R)‐fluoroproline ((4R)‐Flp) and (4S)‐fluoroproline ((4S)‐Flp) have been used in protein engineering to enhance the thermodynamic stability of peptides and proteins. The electron‐withdrawing effect of fluorine can bias the pucker of the pyrrolidine ring, influence the conformational preference of the preceding peptide bond, and can accelerate the cis/trans prolyl peptide bond isomerisation by diminishing its double bond character. The role of 4,4‐difluoroproline (Dfp) in the acceleration of the refolding rate of globular proteins bearing a proline (Pro) residue in the cis conformation in the native state remains elusive. Moreover, the impact of Dfp on the thermodynamic stability and bioactivity of globular proteins has been seldom described. In this study, we show that the incorporation of Dfp caused a redox state dependent and position dependent destabilisation of the thioredoxin (Trx) fold, while the catalytic activities of the modified proteins remained unchanged. The Pro to Dfp substitution at the conserved cisPro76 in the thioredoxin variant Trx1P did not elicited acceleration of the rate‐limiting trans‐to‐cis isomerization of the Ile75‐Pro76 peptide bond. Our results show that pucker preferences in the context of a tertiary structure could play a major role in protein folding, thus overtaking the rules determined for cis/trans isomerisation barriers determined in model peptides.
Comparative studies on physicochemical properties of rice with germinated dark purple giant embryo rice and normal embryo rice
Authors: Chung Soo Im , Kang Mi Young
Published: September 2021

Background and objectives

As a cultivar developed by breeding, pigmented rice Keunnunjami has a dark purple pericarp and a giant embryo and has been found to possess strong antioxidant properties. The present study investigated the effect of 72‐hr germination on the physicochemical properties of Keunnunjami, in comparison with that of its parental pigmented normal embryo cultivar, Heukjinju, and ordinary normal brown rice.

Findings

Germination generally increased the amounts of reducing sugar, amino acids isoleucine, leucine, phenylalanine, valine, alanine, cysteine, glycine, proline, and tyrosine, and minerals such as calcium, magnesium, and phosphorus while it decreased the levels of histidine, lysine, methionine, threonine, arginine, aspartic acid, glutamic acid, serine, and potassium in the rice grains. The germinated Keunnujami exhibited higher amounts of essential and non‐essential amino acids and reducing sugar than the germinated Heukjinju and normal brown rice. The starch granules from all rice samples showed holes and pits on the surface after germination.

Conclusions

These changes in the chemical composition and morphological properties are possibly due to partial hydrolysis of starch and protein caused by enzymes that were activated during germination.

Significance and novelty

Results of this study could serve as the baseline information for evaluating the quality and possible food industry applications of germinated Keunnunjami.
The first description of a singular case of synchronous chronic myelomonocytic leukemia and diffuse large b‐cell lymphoma
Authors: Romano Alessandra , Giusti Michele , Di Giorgio MaryAnn , Lumera Giovanni , Laura Parrinello Nunziatina , Cosentino Sebastiano , Ippolito Massimo , Villari Loredana , Alberto Palumbo Giuseppe , Di Raimondo Francesco , Santo Signorelli Salvatore
Published: September 2021

In CMML, neoplastic monocytes can be distinguished based on their immunophenotype. Supportive care myeloid growth factors in concomitant extranodal non‐Hodgkin Lymphoma are safe.
Computational Analysis of Photophysical Properties and Reactivity of a New Phototherapeutic Cyclometalated Au(III)‐Hydride Complex
Authors: Scoditti Stefano , Mazzone Gloria , Sicilia Emilia
Published: September 2021

Gold(III) complexes have recently emerged as new versatile and efficacious metal containing anticancer agents. In an attempt to reconcile the specific affinity of such complexes for target sulfur containing biomolecules with their capability to strongly bind thiol‐containing compounds widely distributed in non‐tumoral cells, a new series of cyclometalated Au(III)‐hydride complexes has been proposed as photoactivatable anticancer prodrugs. Here, the computational exploration of the photophysical properties and reactivity in dark and under light irradiation of the first member of the series, named 1 a, is reported. Complex 1 a low hydricity in dark together with facile hydride substitution leading to H2 elimination under excitation by visible light have been examined by means of DFT and TD‐DFT computations. Both singlet and triplet excited states have been characterized, allowing the identification of the active species involved in photoactivation pathways leading to the controlled detachment of the hydride ligand. Also the viable two‐photon activation at the ideal phototherapeutic window has been investigated.
Microwave Spectrum of Two‐Top Molecule: 2‐Acetyl‐3‐Methylthiophene
Authors: Dindić Christina , Nguyen Ha Vinh Lam
Published: September 2021

The microwave spectrum of 2‐acetyl‐3‐methylthiophene (2A3MT) was recorded in the frequency range from 2 to 26.5 GHz using a molecular jet Fourier transform microwave spectrometer and could be fully assigned to the anti‐conformer of the molecule, while the syn‐conformer was not observable. Torsional splittings of all rotational transitions in quintets due to internal rotations of the acetyl methyl and the ring methyl groups were resolved and analyzed, yielding barriers to internal rotation of 306.184(46) cm−1 and 321.813(64) cm−1, respectively. The rotational and centrifugal distortion constants were determined with high accuracy, and the experimental values are compared to those derived from quantum chemical calculations. The experimentally determined inertial defect supports the conclusion that anti‐2A3MT is planar, even though a number of MP2 calculations predicted the contrary.
Dean executes enrollment strategy rooted in social justice
Authors: Enos Gary A.
Published: September 2021

Demands for higher quality and a deep‐seated drive for social justice fuel the efforts of Mildred Lewis, Ed.D., as Dean of Enrollment Services at Laney College in Oakland, Calif. The community college has taken a more strategic approach to enrollment management over the past four years, making sure prospective and incoming students have the tools necessary to know that Laney is a fit and that their journey will go smoothly when they get there.
Implementing general environmental duties: Regulators' perceptions of complementary toolkits
Authors: Edwards Joel , Windholz Eric , Faulkner Nicholas , Werbeloff Lara
Published: September 2021

Statutory general duties prioritise the prevention of harm, placing the onus for compliance on individuals and businesses alike to take steps to manage risks posed by their activities. In the case of general environmental duties specifically, they mandate that all parts of the community minimise the risk of environmental harm from their activities. However, encouraging compliant behaviour across such a diverse cohort is a significant challenge. To assist in meeting this challenge, general duties are supported by a variety of complementary regulatory tools. However, little is known about which complementary tools are used by regulators to support general environmental duties, and which factors may influence their application. This article addresses this knowledge gap, with a focus on Anglosphere countries where the use of statutory general duties is becoming increasingly popular. Through semi‐structured interviews with staff from environmental and occupational health and safety regulators, we demonstrate that the existence of a complementary tool does not necessarily mean it will be selected, and that staff responsible for the implementation of general duties are influenced by seven factors. These factors impact not only the selection of complementary tools, but when and how they are applied. The article concludes by discussing implications for practise and future research.
Aptamer‐functionalized Ti3C2‐MXene Nanosheets with One‐step Potentiometric Detection of Programmed Death‐ligand 1
Authors: Li Bin , Pu Wenyuan , Weng Lingyan , Lyu Peng , Xu Houxi , Zhang Wen , Ge Lilin , Kwok Hang Fai , Wu Qinan
Published: September 2021

This communication describes a simple sensitive one‐step potentiometric aptasensing method for quantitative detection of a referenced therapeutic biomarker (programmed death‐ligand 1, PD−L1). The aptasensor is constructed by modifying PD−L1‐specific aptamer on Ti3C2‐MXene nanosheets‐functionalized electrode. Introduction of PD−L1 induces the specific reaction between PD−L1 and aptamer, thereby resulting in the change of spatial structures. The surface electric potential of modified electrode is shifted upon addition of PD−L1 proteins before and after the reaction of aptamer with the analyte. Interestingly, potentiometric aptamer with Ti3C2‐MXene nanosheets can achieve a higher sensitivity and a lower detection limit toward target PD−L1 relative to aptamer‐modified electrode. Experimental results indicated that the linear range and detection limit of using Ti3C2‐MXene nanosheets were 0.01–100 ng mL−1 and 7.8 pg mL−1 PD−L1, respectively. Meanwhile, the specificity, reproducibility, storing stability and accuracy of potentiometric aptasensor are acceptable for the screening of PD−L1 in human serum samples.
Feature reduction scheme for anomaly‐based intrusion detection in wireless networks: Building of hybrid model
Authors: Gavel Shashank , Singh Jyotsana , Shukla Namrata , Raghuvanshi Ajay Singh , Tiwari Sudarshan
Published: September 2021

Anomaly‐based intrusion detection plays a crucial and essential role in providing security to computer networks. However, some concerns still exist for the sustainability and feasibility of existing approaches over modern networks. Specifically, these concerns relate to increasing many features from a network, thus making it difficult for a user to achieve high detection accuracy. This article presents a novel and efficient feature reduction scheme for fault‐based intrusion detection by efficiently handling the large feature from a network. Monarch butterfly optimization is used with a new correlation‐based fitness function to reduce features. Twin support vector machine is utilized with its unique classification in the proposed scheme. The proposed method is analyzed and evaluated with NSL‐KDD, CICIDS2017, AWID network security, and standard fault network datasets. The obtained results are verified using standard performance measures, that is, overall detection accuracy, F‐measure, FPR, and AUC score with time complexity. The results show the superiority and stability of the proposed scheme over the existing techniques.
Fully automated delineation of the optic radiation for surgical planning using clinically feasible sequences
Authors: Reid Lee B. , Martínez‐Heras Eloy , Manjón Jose V. , Jeffree Rosalind L. , Alexander Hamish , Trinder Julie , Solana Elisabeth , Llufriu Sara , Rose Stephen , Prior Marita , Fripp Jurgen
Published: September 2021

Quadrantanopia caused by inadvertent severing of Meyer's Loop of the optic radiation is a well‐recognised complication of temporal lobectomy for conditions such as epilepsy. Dissection studies indicate that the anterior extent of Meyer's Loop varies considerably between individuals. Quantifying this for individual patients is thus an important step to improve the safety profile of temporal lobectomies. Previous attempts to delineate Meyer's Loop using diffusion MRI tractography have had difficulty estimating its full anterior extent, required manual ROI placement, and/or relied on advanced diffusion sequences that cannot be acquired routinely in most clinics. Here we present CONSULT: a pipeline that can delineate the optic radiation from raw DICOM data in a completely automated way via a combination of robust pre‐processing, segmentation, and alignment stages, plus simple improvements that bolster the efficiency and reliability of standard tractography. We tested CONSULT on 696 scans of predominantly healthy participants (539 unique brains), including both advanced acquisitions and simpler acquisitions that could be acquired in clinically acceptable timeframes. Delineations completed without error in 99.4% of the scans. The distance between Meyer's Loop and the temporal pole closely matched both averages and ranges reported in dissection studies for all tested sequences. Median scan‐rescan error of this distance was 1 mm. When tested on two participants with considerable pathology, delineations were successful and realistic. Through this, we demonstrate not only how to identify Meyer's Loop with clinically feasible sequences, but also that this can be achieved without fundamental changes to tractography algorithms or complex post‐processing methods.
Paramagnetic Oxygen as Contrast Agent for a Potential PDT Treatment MRI Monitoring
Authors: Chevreux Sylviane , Four Mickaël , Lemercier Gilles
Published: September 2021

As a proof of concept, we demonstrate in this preliminary study that 3O2 could be used as magnetic Contrast Agent (CA) to monitor photodynamic treatments (PDT). In this purpose, and using a well‐studied Photo‐Sensitizer (PS) from our team (Ruteg), we highlighted that the combined action of the PS and irradiation led to significant changes in T1 (and R1) values of the protons of the water molecules. We assume that with these conclusive results using relaxometric measurements, transposition to Magnetic Resonance Imaging (MRI) in pertinent conditions (oxygen concentration, magnetic field) should be achievable.
The Caputo–Fabrizio (CF) and Atangana–Baleanu in Caputo sense (ABC) fractional time‐derivative approach on transient free convection flow between two vertical parallel plates: A semi‐analytical solution
Authors: Jha Basant K. , Oyelade Ismaila Olatoye , B. Malgwi Peter
Published: September 2021

A comparative analysis on semi‐analytical solution of transient free convection flow of fractional Maxwell viscoelastic fluid between two vertical parallel plates has been investigated by employing the Caputo–Fabrizio (CF) and Atangana–Baleanus in Caputo sense (ABC) fractional time derivative. The semi‐analytical solutions for dimensionless temperature, velocity, skin friction, and mass flux are obtained using both approach (CF and ABC) and solution presented in the Laplace domain. The Riemann sum approximation was used to invert all solutions from the Laplace domain to the time domain. The influence of pertinent parameters on dimensionless temperature and velocity for both CF and ABC approach are presented graphically and in tabular form and thereafter discussed. The significant result obtained from this study is that both temperature and velocity in CF and ABC increase as the time and relaxation time parameter increases, while temperature and velocity via CF and ABC model decrease when the fractional parameter increases. It is also significant to note that, temperature, velocity, skin friction, and mass flux have a higher value in the CF model than the ABC model.
Current and recommended practices for evaluating adverse drug events using electronic health records: A systematic review
Authors: Ng Ding Quan , Dang Emily , Chen Lijie , Nguyen Mary Thuy , Nguyen Michael Ky Nguyen , Samman Sarah , Nguyen Tiffany Mai Thy , Cadiz Christine Luu , Nguyen Lee , Chan Alexandre
Published: September 2021

Electronic health records (EHR) are widely used sources of real‐world data in pharmacoepidemiologic research. As there is no end‐to‐end guidance for generating medication safety evidence with EHR, this study conducted a systematic review to determine the current and recommended practices in the literature. PubMed, Scopus, and CINAHL were searched for English articles published between 1 January 2010 and 11 June 2020. Selected articles were published in peer‐reviewed journals, conducted in the United States, analyzed structured EHR data, and defined drug exposure and adverse drug events (ADEs). The study evaluated methodological quality with a modified Newcastle‐Ottawa Scale (NOS) score ranging from 0 to 9 points. Data synthesis was performed with thematic analysis. Twenty‐six from 3885 articles were selected. The majority were cohort studies (85%). The studies were well designed, with a median NOS score of 9. Drug exposure was defined with dispensing (58%) and prescribing (31%) records. ADEs were defined across five categories: diagnosis codes (77%), validated outcome algorithms (35%), objective measures (35%), treatment procedures (19%), and antidotes (2%). Common covariates were age (89%), gender (85%), comorbidities (81%), and medication‐co‐medication use (73%). Four studies (15%) empirically defined covariates in a data‐driven manner. Twenty‐two (85%) analyzed covariates as confounders or effect modifiers in their analyses. Results were analyzed with either intention‐to‐treat (73%) or as‐treated (39%) approaches. Key recommendations include selecting dispensing rather than prescribing records, considering a proxy date of dispensation where applicable, selecting new instead of prevalent drug users, improving adoption of validated outcome algorithms, and not utilizing objective measures as the primary indicator of ADEs.
A facile chemical process to form an ultrathin hydroxyapatite layer with a customizable silver‐releasing function on a titanium implant
Authors: Ohtsu Naofumi , Kakuchi Yuko , Takahara Toyofumi , Yoshida Yutaka
Published: September 2021

Silver‐containing hydroxyapatite (Ag/HAp) layer on a bioinert material provides both bioactive and antibacterial properties; however, the Ag release duration needs to be customized to a patient's age and metabolism for minimizing the toxic effects. Herein, we present a facile chemical process to produce an ultrathin Ag/HAp layer on a Ti implant with a customized Ag‐releasing profile. The process involves the following steps: preparation of a slurry‐type reagent by mixing calcium phosphate powder with an aqueous AgNO3solution, burying a Ti substrate in the slurry, and heating the slurry in air. An HAp layer, approximately 50 nm thick, with Ag particle deposits was obtained using this process. The Ag‐particle content can be varied by adjusting the concentration of AgNO3solution used for slurry preparation, resulting in different Ag‐release profiles in a physiological solution. For instance, Ag release was retained for up to 30 days when 100 mM AgNO3was used, whereas the release lasted 15 days when 10 mM AgNO3was used. The duration of the antibacterial activity varied accordingly, but Ag‐release‐derived cytotoxicity was not observed irrespective of the AgNO3concentration. In addition, differentiation of osteoblast‐like cells was facilitated owing to the formation of the HAp layer. Thus, the chemical process presented in this study allows the production—at a clinical site—of an Ag/HAp layer customized to the patient's needs.
3‐Degenerate induced subgraph of a planar graph
Authors: Gu Yangyan , Kierstead H. A. , Oum Sang‐il , Qi Hao , Zhu Xuding
Published: September 2021

A graph is ‐degenerate if every nonnull subgraph of has a vertex of degree at most . We prove that every ‐vertex planar graph has a 3‐degenerate induced subgraph of order at least .
Achieving consistency in measures of HIV‐1 viral suppression across countries: derivation of an adjustment based on international antiretroviral treatment cohort data
Authors: Johnson Leigh F. , Kariminia Azar , Trickey Adam , Yiannoutsos Constantin T. , Ekouevi Didier K. , Minga Albert K. , Pascom Ana Roberta Pati , Han Win Min , Zhang Lei , Althoff Keri N. , Rebeiro Peter F. , Murenzi Gad , Ross Jonathan , Hsiao Nei‐Yuan , Marsh Kimberly
Published: September 2021

Introduction

The third of the Joint United Nations Programme on HIV/AIDS (UNAIDS) 90‐90‐90 targets is to achieve a 90% rate of viral suppression (HIV viral load <1000 HIV‐1 RNA copies/ml) in patients on antiretroviral treatment (ART) by 2020. However, some countries use different thresholds when reporting viral suppression, and there is thus a need for an adjustment to standardize estimates to the <1000 threshold. We aim to propose such an adjustment, to support consistent monitoring of progress towards the “third 90” target.

Methods

We considered three possible distributions for viral loads in ART patients: Weibull, Pareto and reverse Weibull (imposing an upper limit but no lower limit on the log scale). The models were fitted to data on viral load distributions in ART patients in the International epidemiology Databases to Evaluate AIDS (IeDEA) collaboration (representing seven global regions) and the ART Cohort Collaboration (representing Europe), using separate random effects models for adults and children. The models were validated using data from the World Health Organization (WHO) HIV drug resistance report and the Brazilian national ART programme.

Results

Models were calibrated using 921,157 adult and 37,431 paediatric viral load measurements, over 2010–2019. The Pareto and reverse Weibull models provided the best fits to the data, but for all models, the “shape” parameters for the viral load distributions differed significantly between regions. The Weibull model performed best in the validation against the WHO drug resistance survey data, while the Pareto model produced uncertainty ranges that were too narrow, relative to the validation data. Based on these analyses, we recommend using the reverse Weibull model. For example, if a country reports an 80% rate of viral suppression at <200 copies/ml, this model estimates the proportion virally suppressed at <1000 copies/ml is 88.3% (0.800.56), with uncertainty range 85.5–90.6% (0.800.70–0.800.44).

Conclusions

Estimates of viral suppression can change substantially depending on the threshold used in defining viral suppression. It is, therefore, important that viral suppression rates are standardized to the same threshold for the purpose of assessing progress towards UNAIDS targets. We have proposed a simple adjustment that allows this, and this has been incorporated into UNAIDS modelling software.
Estimating male circumcision coverage in 15 priority countries in sub‐Saharan Africa
Authors: Stegman Peter M. , Yee Randy , Davis Joshua , Tchuenche Michel , Linder Rachael , Zembe Lycias , Frescura Luisa , Kripke Katharine E.
Published: September 2021

Introduction

Given the importance of voluntary medical male circumcision (VMMC) in reducing HIV incidence, access to and use of quality data for programme planning and management are essential. Unfortunately, such data are currently not standardized for reliable and consistent programme use in priority countries. To redress this, the UNAIDS Reference Group (RG) on Estimates, Modelling, and Projection worked with partner Avenir Health to use the Decision Makers Program Planning Toolkit (DMPPT) 2 Online to provide estimates of VMMC coverage and to support countries to set age‐ and geographic‐specific targets. This article describes the methods and tools used for assembling, reviewing and validating VMMC programme data as part of the 2021 Estimates process.

Discussion

The approach outlined for integrating VMMC data using the DMPPT2 Online required significant country engagement as well as upgrades to the DMPPT2 Online. The process brought together local‐level VMMC stakeholders, for example Ministries of Health, the Joint United Nations Programme on HIV/AIDS (UNAIDS), the US President's Emergency Plan for AIDS Relief, the World Health Organization (WHO), VMMC implementers and so on, to review, amend and agree on historical and more recent VMMC data. The DMPPT2 Online was upgraded to align with the Spectrum and Naomi models used in the Annual HIV Estimates process. In addition, new and revised inputs were incorporated to enhance accuracy of modelled outputs. The process was successful in mobilizing stakeholders behind efforts to integrate VMMC into the annual HIV Estimates process and generating comprehensive, country‐owned and validated VMMC data that will enhance programme monitoring and planning.

Conclusions

VMMC programme data from most of the priority countries were successfully reviewed, updated, validated and incorporated into the annual HIV Estimates process in 2020. It is important to ensure that these data continue to be used for programme planning and management. Current and future data issues will need to be addressed, and countries will need ongoing support to do so. The integration of the DMPPT2 Online into the annual HIV Estimates process is a positive step forward in terms of streamlining country‐owned planning and analytical practices for the HIV response.
Coinfection between SARS‐CoV‐2 and vector‐borne diseases in Luanda, Angola
Authors: Sebastião Cruz S. , Gaston Celestina , Paixão Joana Paula , Sacomboio Euclides N. M. , Neto Zoraima , de Vasconcelos Jocelyne Neto , Morais Joana
Published: September 2021

Co‐epidemics happening simultaneously can generate a burden on healthcare systems. The co‐occurrence of SARS‐CoV‐2 with vector‐borne diseases (VBD), such as malaria and dengue in resource‐limited settings represents an additional challenge to the healthcare systems. Herein, we assessed the coinfection rate between SARS‐CoV‐2 and VBD to highlight the need to carry out an accurate diagnosis and promote timely measures for these infections in Luanda, the capital city of Angola. This was a cross‐sectional study conducted with 105 subjects tested for the SARS‐CoV‐2 and VBD with a rapid detection test in April 2021. The participants tested positive for SARS‐CoV‐2 (3.80%), malaria (13.3%), and dengue (27.6%). Low odds related to testing positivity to SARS‐CoV‐2 or VBD were observed in participants above or equal to 40 years (odds ratio [OR]: 0.60, p = 0.536), while higher odds were observed in male (OR: 1.44, p = 0.392) and urbanized areas (OR: 3.78, p = 0.223). The overall co‐infection rate between SARS‐CoV‐2 and VBD was 11.4%. Our findings showed a coinfection between SARS‐CoV‐2 with malaria and dengue, which could indicate the need to integrate the screening for VBD in the SARS‐CoV‐2 testing algorithm and the adjustment of treatment protocols. Further studies are warranted to better elucidate the relationship between COVID‐19 and VBD in Angola.
Comparison of proteomic approaches used for the detection of potential biomarkers of Alzheimer's disease in blood plasma
Authors: Smirnova Tatiana Anatolievna , Viskin Anton , Hoskova Martina , Habartova Lucie , Setnicka Vladimir , Cejnar Pavel , Kuckova Stepanka
Published: September 2021

At present, Alzheimer's disease is detected mainly using psychological tests, which can only confirm the disease in its more advanced phases. Therefore, bioanalytical possibilities for detecting this disease earlier are being investigated. To date, the results of analyses, which focus mainly on the study of lipids and proteins either in cerebrospinal fluid or much less often in blood plasma, do not provide satisfactory results. In addition, cerebrospinal fluid sampling is uncomfortable for the patients and involves many health risks. In this work, we deal with proteomic analysis using Matrix‐Assisted Laser Desorption/Ionisation—Time of Flight and Liquid Chromatography coupled to tandem Mass Spectrometry of blood plasma with a focus on various ways of preanalytical sample treatments. This should lead to results improvement and facilitate the subsequent evaluation using principal component analysis and partial least squares discriminant analysis. The obtained results indicate the direction of further research, namely the study of interactions between proteins and lipids contained in blood plasma. These substances may be regarded as potential biomarkers allowing for the diagnosis of Alzheimer´s disease even in its early stages.
Deep learning methods for automatic segmentation of lower leg muscles and bones from MRI scans of children with and without cerebral palsy
Authors: Zhu Jiayi , Bolsterlee Bart , Chow Brian V. Y. , Cai Chengxue , Herbert Robert D. , Song Yang , Meijering Erik
Published: September 2021

Cerebral palsy is a neurological condition that is known to affect muscle growth. Detailed investigations of muscle growth require segmentation of muscles from MRI scans, which is typically done manually. In this study, we evaluated the performance of 2D, 3D, and hybrid deep learning models for automatic segmentation of 11 lower leg muscles and two bones from MRI scans of children with and without cerebral palsy. All six models were trained and evaluated on manually segmented T1‐weighted MRI scans of the lower legs of 20 children, six of whom had cerebral palsy. The segmentation results were assessed using the median Dice similarity coefficient (DSC), average symmetric surface distance (ASSD), and volume error (VError) of all 13 labels of every scan. The best performance was achieved by H‐DenseUNet, a hybrid model (DSC 0.90, ASSD 0.5 mm, and VError 2.6 cm3). The performance was equivalent to the inter‐rater performance of manual segmentation (DSC 0.89, ASSD 0.6 mm, and VError 3.3 cm3). Models trained with the Dice loss function outperformed models trained with the cross‐entropy loss function. Near‐optimal performance could be attained using only 11 scans for training. Segmentation performance was similar for scans of typically developing children (DSC 0.90, ASSD 0.5 mm, and VError 2.8 cm3) and children with cerebral palsy (DSC 0.85, ASSD 0.6 mm, and VError 2.4 cm3). These findings demonstrate the feasibility of fully automatic segmentation of individual muscles and bones from MRI scans of children with and without cerebral palsy.
Effectiveness of a group‐walking intervention for people with dementia based on quality of life and caregivers’ burden
Authors: Kohler Myrta , Mullis Jeanette , Karrer Melanie , Schwarz Juerg , Saxer Susi
Published: September 2021

Aims

To test the effectiveness of a 28‐week group‐walking intervention for person with dementia. Participants were accompanied by trained volunteers. The effectiveness was assessed according to the quality of life, ability to perform activities of daily living, independence, mobility, cognition, challenging behaviours and the burden on their caregiving relatives.

Design

Quasi‐experimental, one‐group, pretest–posttest trial.

Methods

Thirty‐two persons with dementia and their caregiving relatives were recruited. The nursing intervention consists on easy walking tours lasting three and a half hours. The walks were performed biweekly and each person with dementia had support from one or two trained volunteer helpers.

Results

The quality of life was stable through all seasons. The secondary outcomes were uneven. While the impairment (WHODAS) and the dependence (IADL) increased, the challenging behaviours and the burden on the caregivers were stable through all seasons.
Ask the Authors
Authors: Prather Heidi , Wu Fiona , Rampal Tarannum , Laza‐Cagigas Roberto
Published: September 2021

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