bluuebunny/crossref_metadata_2025 huggingface dataset:
COVID‐19 detection with severity level analysis using the deep features, and wrapper‐based selection of ranked features
Authors: Öksüz Coşku , Urhan Oğuzhan , Güllü Mehmet Kemal
Published: December 2021

The SARS‐COV‐2 virus, which causes COVID‐19 disease, continues to threaten the whole world with its mutations. Many methods developed for COVID‐19 detection are validated on the data sets generally including severe forms of the disease. Since the severe forms of the disease have prominent signatures on X‐ray images, the performance to be achieved is high. To slow the spread of the disease, effective computer‐assisted screening tools with the ability to detect the mild and the moderate forms of the disease that do not have prominent signatures are needed. In this work, various pretrained networks, namely GoogLeNet, ResNet18, SqueezeNet, ShuffleNet, EfficientNetB0, and Xception, are used as feature extractors for the COVID‐19 detection with severity level analysis. The best feature extraction layer for each pre‐trained network is determined to optimize the performance. After that, features obtained by the best layer are selected by following a wrapper‐based feature selection strategy using the features ranked based on Laplacian scores. The experimental results achieved on two publicly available data sets including all the forms of COVID‐19 disease reveal that the method generalized well on unseen data. Moreover, 66.67%, 90.32%, and 100% sensitivity are obtained in the detection of mild, moderate, and severe cases, respectively.
Programmed Assembly of DNA Templates by Silver Nanowires
Authors: Vittala Sandeepa K. , Zhao Yumeng , Han Da
Published: December 2021

DNA origami templates are known to exhibit many advantages to integrate functional components at desirable locations for nanoelectronic applications. In order to immobilize conducting or semiconducting species in a bottom‐up approach, the programmed assembly of DNA templates is of utmost necessity. This report demonstrates the silver nanowires enabled bridging of two linear DNA origami (DO) nanostructures by utilizing the host‐guest interaction of biotin‐STV and sequence‐specific silver metallization of poly(dG‐dC) DNA nanowires (in 10 % yield) using (dA)10 coated AgNPs (15 nm). The enzymatic synthesis of 750 bp, 1500 bp and 3000 bp bis‐biotinylated poly(dG‐dC), facile synthesis of 1 : 1 biotin‐STV and silver‐nanowire bridged DNA templates were characterized by gel electrophoresis, atomic force microscope imaging techniques. The strategy utilized here provides a method that can precisely connect heterogeneous templates towards bottom‐up fabrication of practical nanoelectronics.
Characterizing worry content and impact in pregnant and postpartum women with anxiety disorders during COVID‐19
Authors: Green Sheryl M. , Furtado Melissa , Inness Briar E. , Frey Benicio N. , McCabe Randi E.
Published: December 2021

The novel COVID pandemic has had a substantial impact on global mental health, including those populations that are inherently vulnerable such as pregnant and postpartum (perinatal) women. Anxiety disorders (ADs) are the most common mental health disorders during the perinatal period, affecting up to one in five women. However, since the onset of the pandemic, up to 60% of perinatal women are experiencing moderate to severe levels of anxiety. Given the substantial increase in perinatal anxiety during COVID, we sought to better understand its phenomenology by characterizing the collective worry content and impact of COVID using a content analysis. Eighty‐four treatment‐seeking pregnant (n = 35) and postpartum (n = 49) women with a principal AD, participated in this study between April and October 2020. In addition to completing questionnaire measures and a semistructured diagnostic interview, participants were asked to (1) describe their top excessive and uncontrollable worries, (2) describe additional COVID and non‐COVID worries, and (3) describe how the pandemic had affected their lives. All responses were given verbally and transcribed verbatim by assessors. A content analysis led to the emergence of various COVID and non‐COVID worry and impact themes. One third of participant's principal worries were specific to COVID, and 40% of COVID worries were specific to the perinatal context. Understanding the worry content and impact of COVID may improve symptom detection and inform the development of targeted treatment strategies to support the mental health needs of perinatal women with ADs throughout the pandemic and thereafter. Understanding pandemic‐specific worries is important for perinatal symptom screening and may allow for the development of targeted treatment strategies to address COVID‐specific worries and impact.
Mechanochemical Nucleophilic Substitution of Alcohols via Isouronium Intermediates**
Authors: Dalidovich Tatsiana , Nallaparaju Jagadeesh Varma , Shalima Tatsiana , Aav Riina , Kananovich Dzmitry G.
Published: December 2021

An expansion of the solvent‐free synthetic toolbox is essential for advances in the sustainable chemical industry. Mechanochemical reactions offer a superior safety profile and reduced amount of waste compared to conventional solvent‐based synthesis. Herein a new mechanochemical method was developed for nucleophilic substitution of alcohols using fluoro‐N,N,N′,N′‐tetramethylformamidinium hexafluorophosphate (TFFH) and K2HPO4 as an alcohol‐activating reagent and a base, respectively. Alcohol activation and reaction with a nucleophile were performed in one milling jar via reactive isouronium intermediates. Nucleophilic substitution with amines afforded alkylated amines in 31–91 % yields. The complete stereoinversion occurred for the SN2 reaction of (R)‐ and (S)‐ethyl lactates. Substitution with halide anions (F−, Br−, I−) and oxygen‐centered (CH3OH, PhO−) nucleophiles was also tested. Application of the method to the synthesis of active pharmaceutical ingredients has been demonstrated.
Searching beyond the streetlight: Neonicotinoid exposure alters the neurogenomic state of worker honey bees
Authors: Tsvetkov Nadejda , Zayed Amro
Published: December 2021

Neonicotinoid insecticides have been implicated in honey bee declines, with many studies showing that sublethal exposure impacts bee behaviors such as foraging, learning, and memory. Despite the large number of ecotoxicological studies carried out to date, most focus on a handful of worker phenotypes leading to a “streetlight effect” where the a priori choice of phenotypes to measure may influence the results and conclusions arising from the studies. This bias can be overcome with the use of toxicological transcriptomics, where changes in gene expression can provide a more objective view of how pesticides alter animal traits. Here, we used RNA sequencing to examine the changes in neurogenomic states of nurse and forager honey bees that were naturally exposed to neonicotinoids in the field and artificially exposed to neonicotinoids in a controlled experiment. We found that neonicotinoid exposure influenced the neurogenomic state of foragers and nurses in different ways; foragers experienced shifts in expression of genes involved in cognition and development, while nurses experienced shifts in expression of genes involved in metabolism. Our study suggests that neonicotinoids influence nurse and forager bees in a different manner. We also found no to minimal overlap in the differentially expressed genes in our study and in previously published studies, which might help reconcile the seemingly contradictory results often reported in the neonicotinoid literature.
A temporal trophic shift from primary parasitism to facultative hyperparasitism during interspecific competition between two coevolved scelionid egg parasitoids
Authors: Haye Tim , Zhang Jinping , Risse Marion , Gariepy Tara D.
Published: December 2021

Understanding competition between scelionid parasitoids that exploit the same host may provide insight into strategies that allow coexistence on a shared resource. Competition studies typically focus on interactions between native and exotic parasitoids that do not share an evolutionary history; however, coevolved parasitoids may be more likely to demonstrate strategies to avoid or exploit a shared resource. We examined intrinsic and extrinsic competition between Asian Trissolcus japonicus (Ashmead) and T. cultratus (Mayr) (Hymenoptera: Scelionidae) associated with Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) that share an evolutionary history. Interspecific interactions were assessed by providing parasitized egg masses to each species at various intervals post‐parasitism, and measuring host acceptance, developmental suitability, and guarding behaviour. Trissolcus japonicus showed high acceptance of parasitized hosts up to 72 h following oviposition by T. cultratus, despite a very poor developmental outcome. In contrast, T. cultratus generally avoided ovipositing in H. halys eggs containing T. japonicus early‐instar larvae but did not avoid parasitizing H. halys that contained eggs and third instar larvae. The adaptive value of this behaviour was supported by developmental outcome: T. cultratus outcompeted T. japonicus eggs but not early‐instar larvae, and a trophic shift occurred wherein T. cultratus developed as a facultative hyperparasitoid on third instar T. japonicus larvae. Trissolcus japonicus guarded egg masses 8–12× longer and displayed more aggressive interactions than T. cultratus, suggesting T. japonicus is the superior extrinsic competitor. Development as a facultative hyperparasitoid provided a competitive niche for Asian T. cultratus and confirms its instrinsic competitive superiority. This also occurs in a biologically distinct European population of T. cultratus, suggesting that facultative hyperparasitism as a competitive strategy is retained in geographically separated populations that have not coevolved with H. halys or T. japonicus.
Volume Increments for Crystalline Borates
Authors: Wied Jan K. , Bsharat Ahd , Sauskojus Wolfgang , Mangstl Martin , Weber Johannes , Schmedt auf der Günne Jörn
Published: December 2021

A set of volume increments for ionic oxido‐borates is developed for trigonal‐planar and tetrahedral coordinated boron fragments in densely packed crystal structures. For this purpose, the cell volume of 277 alkaline‐ and earth alkaline borate structures was analyzed with respect to the volume of different anionic borate building units. The volume increments help to determine the number of formula equivalents in a cell which is especially useful for the structure solution process starting from powder diffraction data. This was demonstrated on a new methylammonium borate, [H3CNH3]B5O6(OH)4 ⋅ CH3NHCOH which could be solved from powder X‐ray diffraction data. The compound crystallizes in the monoclinic space group P 1 21/c 1 with the lattice parameters a=7.3040(1) Å, b=11.6377(1) Å, c=17.1065(3) Å, β=107.2167(9)° and Z=4. The structure model is supported as well by 1H, 11B, 13C and 15N solid‐state NMR and quantum chemical calculations.
Synthesis and Electronic Properties of Conjugated syn,syn‐Dithienothiazine Donor‐Acceptor‐Donor Dumbbells
Authors: Nau Jennifer , Brüning Vincent , Biesen Lukas , Knedel Tim‐Oliver , Janiak Christoph , Müller Thomas J. J.
Published: December 2021

A series of conjugated syn,syn‐dithienothiazine donor‐acceptor‐donor dumbbells is readily synthesized by Suzuki coupling or a one‐pot α‐lithiation‐zincation‐Negishi coupling sequence in moderate to good yield. The title compounds are all electron‐rich reversible oxidizable redox systems with a relatively narrow range of oxidation potentials according to cyclic voltammetry. UV/Vis and fluorescence spectroscopy however show a significant effect of the electronic nature of the conjugated bridging system on absorption and emission characteristics. Furthermore, a highly polar excited state can be corroborated by Lippert‐Mataga analysis of the emission solvatochromicity as well as by TD‐DFT calculation of absorption and emission maxima, which classify these dumbbell systems as redox active, luminescent low band gap chromophores with experimentally determined optical band gaps between 2.20 and 2.50 eV.
Genetic variability and genome‐wide marker association studies for starch traits contributing to low glycaemic index in pearl millet
Authors: Yadav Chandra Bhan , Srivastava Rakesh K. , Beynon Sarah , Englyst Klaus , Gangashetty Prakash I. , Yadav Rattan S.
Published: December 2021

Pearl millet grains are naturally rich in high quality starch, dietary fibre, polyphenols and important micronutrients. Grains from a random subset of the global diversity panel (PMiGAP) comprising 166 pearl millet accessions were assessed for total starch (TS), rapidly digestible Starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) content based on available glucose percentage after digestion at various time points. Highly significant genetic variations for SDS, RS and other starch traits were evident amongst the PMiGAP accessions leading to the identification of best accessions for use in the future pearl millet‐breeding programmes. To identify potential candidate genes associated with these starch traits, genome‐wide association studies (GWAS) were performed using 78K single‐nucleotide polymorphisms (SNPs) well distributed across the seven chromosomes of pearl millet. A total of 902 SNPs showed a strong association with various starch traits at ‐log p‐value range from 4.0–9.08. A total of 364 probable candidate genes were identified in the flanking regions of the significantly associated SNPs and high LD (linkage disequilibrium) region, which explains a correlation between nearby variants. Out of these, 19 probable candidate genes exhibited functional relationships with the starch biosynthesis pathway. Three starch synthase genes (Pgl_GLEAN_10026059 and Pgl_GLEAN_10027180) were found to be key probable candidate genes for SDS owing to their prior demonstrated involvement in amylose biosynthesis. Pgl_GLEAN_10018323, encoding β‐amylase and Pgl_GLEAN_10009197, encoding α‐amylase enzyme were identified as probable candidate genes for RDS content. The genetic variability being reported for SDS and RS in the germplasm panel, and the SNP markers associated with such variability, raises the possibility of developing pearl millet varieties with low glycaemic index using conventional and molecular breeding approaches.
Who and what drives informed options trading after the market opens?
Authors: Kang Jongho , Kang Jangkoo , Lee Jaeram
Published: December 2021

This study examines what affects the return predictability of option order imbalances immediately after the market opening and who contributes to this predictability. Although intraday momentum is insignificant, option order imbalances in the first 10 min of trading significantly predict the returns of stock index and index futures for the remainder of the day. Simple market timing strategies result in significant profits even after transaction costs are incurred. This predictive power is more prominent when uncertainty exists in the market or options are attractive to informed investors. Such predictability is mainly driven by institutional traders rather than day traders.
Comparing adjuvant radiation to adjuvant chemoradiation in postsurgical p16+ oropharyngeal carcinoma patients with extranodal extension or positive margins
Authors: Fenlon Jordan B. , Hutten Ryan J. , Weil Christopher R. , Lloyd Shane , Cannon Donald M. , Kerrigan Kathleen , Cannon Richard B. , Hitchcock Ying J.
Published: December 2021

Background

Adjuvant guidelines in surgically resected p16+ oropharyngeal carcinoma (OPC) with positive surgical margins (PSM) or extranodal extension (ENE) are based on randomized controlled trials predating p16 status. It remains unclear if adjuvant chemotherapy is necessary in p16+ patients with these features.

Methods

The National Cancer Database was used to identify cases of nonmetastatic p16+ OPC diagnosed from 2010 to 2017. Patients treated with surgical resection followed by adjuvant radiation (aRT) or adjuvant chemoradiation (aCRT) were eligible for analysis.

Results

A total of 14 071 patients were eligible for analysis. Overall survival (OS) was not statistically different between aRT and aCRT in patients with PSM (hazard ratio (HR) 0.84, 95% confidence interval (CI) 0.56–1.28), ENE (HR 0.93, 95% CI 0.69–1.27) or both (HR 0.73, 95% CI 0.41–1.31).

Conclusions

In patients with p16+ OPC with ENE, PSM, or both, adding chemotherapy to aRT was not associated with improved OS.
Experimental analysis to study the effect of perforated louvered strip‐coiled spring insert on heat transfer performance in a double pipe heat exchanger
Authors: Kumar Rajan , Chandra Prakash
Published: December 2021

Experiments have been conducted to study the effect of louvered strip‐coiled spring (PLSCS) turbulators having different pitches and the same angle of attack on thermal performance and pressure drop of a concentric tube heat exchanger. Two inserts in combined form were used for experimentation under turbulent flow at different Reynolds numbers (Re) ranging between 5000 and 20,000. Two pitches (40 mm and 50 mm) of elliptical‐shaped perforated louvered strips (PLS) having the same angles of attack have been taken that were welded on the central core rod. Spring inserts have the same coil diameter of 12 mm with two varying pitches to achieve pitch ratios of 0.5 and 1. Both heat transfer and pressure drop increase with a decrease in pitches of both LS and spring inserts. Nusselt number has the maximum value with spring of pitch 6 mm in combination with a PLS of 40 mm pitch at which is 130.75% higher than the plain tube at the lowest Re among the PLSCS inserts. With perforation, a slight increase in both Nusselt number and friction factor was observed. The maximum thermal performance efficiency value is 1.105 for the lowest Re value.
Using geographic information systems to inform the public health response to COVID‐19 and structural racism: The role of place‐based initiatives
Authors: Siegal Rachel , Cooper Haley , Capers Tiffany , Kilmer Ryan P. , Cook James R. , Garo Laurie
Published: December 2021

Black communities have been disproportionately impacted by the syndemic of COVID‐19 and structural racism. Place‐based initiatives (PBIs) are well‐positioned to respond to this syndemic. This study sought to highlight disparities in access to social determinants of health (SDH) between two racially segregated communities, assess residents' needs and measure resource accessibility in one predominantly Black community, and describe the PBI's response. We measured racial disparities in access to SDH before COVID‐19 using an SDH Index. We assessed participants' needs using a needs assessment and documented resource availability. A Geographic Information System (GIS) was used to measure resource accessibility. Results show inequities in access to SDH between the two communities before COVID‐19. Following the onset of COVID‐19, unemployment and food insecurity were higher in the predominantly Black community relative to the US population. Available resources did not always align with participants' needs and were less accessible for residents without private transportation. The PBI's response to the syndemic spanned SDH sectors. Inequitable access to SDH may be produced by structural racism and exacerbated by COVID‐19. PBIs are well‐equipped to employ a contextually informed, data‐driven, cross‐sector response to the syndemic.
A systematic review of acute telogen effluvium, a harrowing post‐COVID‐19 manifestation
Authors: Hussain Nabeel , Agarwala Preeti , Iqbal Kinza , Omar Hanaa Mohamed Sheikh , Jangid Gurusha , Patel Vraj , Rathore Sawai Singh , Kumari Chandani , Velasquez‐Botero Felipe , López Guadalupe Abigail Benítez , Vishwakarma Yogesh , Nipu Airin Parvin , Ahmed Noman Khurshid
Published: December 2021

This systematic review focuses on the clinical features, physical examination findings, outcomes, and underlying pathology of acute telogen effluvium (TE), a type of diffuse hair loss, occurring in coronavirus disease 2019 (COVID‐19) recovered patients. MEDLINE/PubMed and Embase databases were queried till October 2021 to identify studies reporting acute TE occurring after COVID‐19 recovery. Data were obtained from 19 studies, which included 465 patients who were diagnosed with acute TE. The median age of these patients was 44 years and 67.5% were females. The most common trichoscopic findings were decreased hair density, the presence of empty follicles, or short regrowing hair. The mean duration from COVID‐19 symptom onset to the appearance of acute TE was 74 days, which is earlier than classic acute TE. Most patients recovered from hair loss, while a few patients had persistent hair fall. Our results highlight the need to consider the possibility of post‐COVID‐19 acute TE in patients presenting with hair fall, with a history of COVID‐19 infection, in the context of COVID‐19 pandemic. Despite being a self‐limiting condition, hair loss post‐COVID‐19 is a stressful manifestation. Identifying COVID‐19 infection as a potential cause of acute TE will help the clinicians counsel the patients, relieving them from undue stress.
Influence of the COVID‐19 pandemic on the incidence and exacerbation of childhood allergic diseases
Authors: Ye Qing , Wang Bili , Liu Huihui
Published: December 2021

To explore the influence of changes in human lifestyle and the living environment caused by nonpharmaceutical interventions in coronavirus disease 2019 (COVID‐19) on allergic diseases, the present study enrolled children who came to the Children's Hospital of Zhejiang University for allergen detection between January 2019 and December 2020. By comparing the positive rates and levels of various allergen‐specific immunoglobulin E (IgE) before and during the COVID‐19 pandemic, the influence of changes in human lifestyle and the living environment caused by prevention and control measures in COVID‐19 on allergic diseases was evaluated. In 2019, 41 648 allergic children went to the hospital, but in 2020, due to the impact of the COVID‐19 epidemic, the number decreased to 24 714. In 2020, the number of allergy visits was the lowest in February and gradually increased. There were 45 879 children with total IgE > 17.5 IU/ml in 2 years, accounting for 69.13% of the total samples, of which the proportion was 68.52% (28 536/41 648) in 2019 and 70.17% (17 343/24 714) in 2020. A total of 29 906 children were positive for one or more allergens in 2 years. It accounts for 45.06% of the total number of samples, of which the proportion is 41.53% (17 296/41 648) in 2019 and 51.02% (12 610/24 714) in 2020. Except for cashew nuts, the positive number of other allergens in 2020 was less than in 2019, especially after June and July 2020. Except for Artemisia argyi, the positive rates of other allergens in 2020 were significantly higher than those in 2019 (p < 0.05). Moreover, the changing trend of the positive allergen rate in each month in 2020 was different from that in 2019. In 2020, except for Dermatophagoides farinae, Dermatophagoides pteronyssinus, and Crab, specific IgE levels of other allergens were not greater than those in 2019 (p < 0.05). Thus it can be seen, during the COVID‐19 pandemic, nonpharmaceutical interventions played a protective role in reducing children's exposure to allergens and alleviating allergic reactions.
Evaluation of a new NS1 rapid diagnostic test using a single acute‐phase serum panel collected during the largest dengue outbreak in Taiwan history in 2015
Authors: Liu Li‐Teh , Chen Chun‐Hong , Lin Ping‐Chang , Tsai Ching‐Yi , Hsu Miao‐Chen , Huang Bo‐Yi , Tsai Yan‐Yi , Tsai Jih‐Jin
Published: December 2021

Dengue virus (DENV) infection results mostly from the bites of virus‐carrying Aedes mosquitoes, which results in dengue fever (DF) with or without warning signs, severe dengue, or asymptomatic infections in humans. For point‐of care identification of DENV‐infected patients, a rapid diagnostic test (RDT) for DENV nonstructural protein 1 (NS1) has been developed to achieve early diagnosis and timely clinical management. We evaluated the performance of a new commercially available dengue NS1 RDT AsiaGen Dengue NS1 Antigen Rapid Diagnosis Test using real‐time qRT‐PCR as a reference method and compared the results with SD BIOLINE Dengue NS1 Ag using a single acute‐phase serum panel collected during the largest dengue outbreak in the history of Taiwan in 2015. The results suggested that the sensitivity and specificity of AsiaGen Dengue NS1 Antigen RDT (96.9% and 100%) were similar to those of SD BIOLINE Dengue NS1 RDT (100% and 100%) for detection in the acute phase of DENV‐2 infection. The results suggested that the sensitivity of both RDTs was similar (95.4% ~ 100%) for the sera collected at less than or equal to three days postsymptom onset (PSO). Our results suggested that the two DENV NS1 RDTs used in this study were promising for the timely diagnosis of DENV infection during dengue outbreaks, at least for DENV‐2 in areas where authorized medical laboratories are not available or medical resources are limited. However, the performance of AsiaGen DENV NS1 RDTs in the detection of primary/secondary infections and infection by serotypes of DENV other than DENV‐2 requires further investigation.
Toward Making Poly(ethylene terephthalate) Degradable in Aqueous Environment
Authors: Li Yanyan , Chen Junhe , Han Wanli , Yi Hongling , Wang Jianning , Xing Peixiang , Ren Jiaxiang , Yao Donggang
Published: December 2021

Polyethylene terephthalate (PET) is a non‐biodegradable polymer, and it takes hundreds of years or longer to degrade in nature. In the current study, it is demonstrated that the addition of calcium oxide (CaO) into PET renders a degradable PET in an aqueous environment. Specifically, PET/CaO composite samples are prepared by melt mixing and compression molding, and the capability of hydrolysis of the composite in an aqueous environment is evaluated using different characterization and testing methods. The results show that the PET/CaO mixture is thermally stable during melt processing, and the resulting composite undergoes controllable hydrolysis in a water bath with calcium terephthalate as a main hydrolysis byproduct. The PET/CaO composite is mechanically strong; for example, a 75/25 PET/CaO sample shows a strength comparable to that of the pure PET polymer. The results further show that the hydrolysis of the PET/CaO composite may be promoted by addition of other fillers such as glass fibers. It is anticipated that the development of such a degradable PET material may impact a number of application areas where disposable packaging materials and water dissolvable composite products are desired.
Frontal‐Photopolymerization of Fully Biobased Epoxy Composites
Authors: Noè Camilla , Hakkarainen Minna , Malburet Samuel , Graillot Alain , Adekunle Kayode , Skrifvars Mikael , Sangermano Marco
Published: December 2021

The radical‐induced cationic frontal photopolymerization (RICFP) of fully biobased epoxy composites is successfully demonstrated. This curing strategy considerably reduces the curing time and improves the efficiency of the composite fabrication. Two different natural fiber fabrics made of cellulose and flax fibers are embedded in two epoxy matrices, one derived from vanillin (diglycidylether of vanillyl alcohol‐DGEVA) and the other from petroleum (3,4‐epoxycyclohexylmethyl 3,4‐epoxycyclohexanecarboxylate‐CE). After RICFP the composites are characterized by means of dynamic mechanical thermal analysis and tensile tests. The mechanical properties improved with increasing fiber content, confirming a strong adhesion between the matrix and the reinforcing fiber fabrics, which is further evidenced by scanning electron microscopy analyses of the fracture surfaces. Furthermore, these fully bio‐based composites possess comparable or even higher mechanical strength compared with the corresponding epoxy composites fabricated with conventional CE resin. A promising facile route to high‐performing natural fiber‐biobased epoxy resin composites is presented.
Chemoinformatic Characterization of Synthetic Screening Libraries Focused on Epigenetic Targets
Authors: Flores‐Padilla E. Alexis , Juárez‐Mercado K. Eurídice , Naveja José J. , Kim Taewon D. , Alain Miranda‐Quintana Ramón , Medina‐Franco José L.
Published: December 2021

The importance of epigenetic drug and probe discovery is on the rise. This is not only paramount to identify and develop therapeutic treatments associated with epigenetic processes but also to understand the underlying epigenetic mechanisms involved in biological processes. To this end, chemical vendors have been developing synthetic compound libraries focused on epigenetic targets to increase the probabilities of identifying promising starting points for drug or probe candidates. However, the chemical contents of these data sets, the distribution of their physicochemical properties, and diversity remain unknown. To fill this gap and make this information available to the scientific community, we report a comprehensive analysis of eleven libraries focused on epigenetic targets containing more than 50,000 compounds. We used well‐validated chemoinformatics approaches to characterize these sets, including novel methods such as automated detection of analog series and visual representations of the chemical space based on Constellation Plots and Chemical Library Networks. This work will guide the efforts of experimental groups working on high‐throughput and medium‐throughput screening of epigenetic‐focused libraries. The outcome of this work can also be used as a reference to design and describe novel focused epigenetic libraries.
Dihydromyricetin Improves Cognitive Impairments in d‐Galactose‐Induced Aging Mice through Regulating Oxidative Stress and Inhibition of Acetylcholinesterase
Authors: Sun Cui‐Cui , Yin Zhong‐Ping , Chen Ji‐Guang , Wang Wen‐Jun , Zheng Guo‐Dong , Li Jing‐En , Chen Ling‐Li , Zhang Qing‐Feng
Published: December 2021

Scope

Alzheimer's disease (AD) is a neurodegenerative disease with phenomena of cognitive impairments. Oxidative stress and cholinergic system dysfunction are two widely studied pathogenesis of AD. Dihydromyricetin (DMY) is a natural dihydroflavonol with many bioactivities. In this study, it is aimed to investigate the effects of DMY on cognitive impairment in d‐galactose (d‐gal) induced aging mice.

Methods and Results

Mice are intraperitoneally injected with d‐gal for 16 weeks, and DMY is supplemented in drinking water. The results show that DMY significantly improves d‐gal‐induced cognitive impairments in novel object recognition and Y‐maze studies. H&E and TUNEL staining show that DMY could improve histopathological changes and cell apoptosis in mice brain. DMY effectively induces the activities of catalase, superoxide dismutase and glutathione peroxidase, and reduces malondialdehyde level in mice brain and liver. Furthermore, DMY reduces cholinergic injury by inhibiting the activity of Acetylcholinesterase (AChE) in mice brain. In vitro studies show that DMY is a non‐competitive inhibitor of AChE with IC50 value of 161.2 µg mL−1.

Conclusion

DMY alleviates the cognitive impairments in d‐gal‐induced aging mice partly through regulating oxidative stress and inhibition of acetylcholinesterase.
Physiological effects of human body imaging with 300 mT/m gradients
Authors: Molendowska Malwina , Fasano Fabrizio , Rudrapatna Umesh , Kimmlingen Ralph , Jones Derek K. , Kusmia Slawomir , Tax Chantal M. W. , Evans C. John
Published: December 2021

Purpose

The use of high‐performance gradient systems (i.e., high gradient strength and/or high slew rate) for human MRI is limited by physiological effects (including the elicitation of magnetophosphenes and peripheral nerve stimulation (PNS)). These effects, in turn, depend on the interaction between time‐varying magnetic fields and the body, and thus on the participant’s position with respect to the scanner’s isocenter. This study investigated the occurrence of magnetophosphenes and PNS when scanning participants on a high‐gradient (300 mT/m) system, for different gradient amplitudes, ramp times, and participant positions.

Methods

Using a whole‐body 300 mT/m gradient MRI system, a cohort of participants was scanned with the head, heart, and prostate at magnet isocenter and a train of trapezoidal bipolar gradient pulses, with ramp times from 0.88 to 4.20 ms and gradient amplitudes from 60 to 300 mT/m. Reports of magnetophosphenes and incidental reports of PNS were obtained. A questionnaire was used to record any additional subjective effects.

Results

Magnetophosphenes were strongly dependent on participant position in the scanner. 87% of participants reported the effect with the heart at isocenter, 33% with the head at isocenter, and only 7% with the prostate at isocenter. PNS was most widely reported by participants for the vertical gradient axis (67% of participants), and was the dominant physiological effect for ramp times below 2 ms.

Conclusion

This study evaluates the probability of eliciting magnetophosphenes during whole‐body imaging using an ultra‐strong gradient MRI system. It provides empirical guidance on the use of high‐performance gradient systems for whole‐body human MRI.
GNE myopathy: Don't sleep on the platelets
Authors: Beecher Grayson , Liewluck Teerin
Published: December 2021

See article on pages 284–290 in this issue.
Fast and stable modification of the Gauss–Newton method for low‐rank signal estimation
Authors: Zvonarev Nikita , Golyandina Nina
Published: December 2021

The weighted nonlinear least‐squares problem for low‐rank signal estimation is considered. The problem of constructing a numerical solution that is stable and fast for long time series is addressed. A modified weighted Gauss–Newton method, which can be implemented through the direct variable projection onto a space of low‐rank signals, is proposed. For a weight matrix that provides the maximum likelihood estimator of the signal in the presence of autoregressive noise of order p the computational cost of iterations is as N
tends to infinity, where N is the time‐series length, r is the rank of the approximating time series. Moreover, the proposed method can be applied to data with missing values, without increasing the computational cost. The method is compared with state‐of‐the‐art methods based on the variable projection approach in terms of floating‐point numerical stability and computational cost.
Hyperglycemia during induction therapy for acute lymphoblastic leukemia is temporally linked to pegaspargase administration
Authors: Pollock Netanya I. , Flamand Yael , Zhu Jia , Millington Kate , Stevenson Kristen , Silverman Lewis B. , Vrooman Lynda M. , Cohen Laurie E.
Published: December 2021

Background

Chemotherapy regimens containing glucocorticoids and pegaspargase are associated with hyperglycemia; however, the pattern and underlying risk factors are not well characterized. We determined the pattern of hyperglycemia and associated factors in children with acute lymphoblastic leukemia (ALL) receiving glucocorticoids and pegaspargase during induction.

Methods

Retrospective analysis of patients treated between 2010 and 2020 at a single institution. Pretreatment data, glucose values, and insulin regimens were abstracted from the record. Hyperglycemia was defined as two or more random glucose measurements ≥200 mg/dl. Analyses of demographic and clinical factors were conducted with logistic regression.

Results

Two hundred thirteen patients, median age 6 years (range 1.0–18.9 years), 47% female, were included. The prevalence of hyperglycemia was 23% (n = 48). Mean glucose levels peaked 3 days following administration of pegaspargase. In multivariable analysis, age ≥10 years (odds ratio [OR] 6.2, 95% confidence interval [CI]: 2.9–13.4), female sex (OR 2.7, 95% CI: 1.2–6.2), and family history of diabetes (OR 3.2, 95% CI: 1.4–7.3) were predictive of hyperglycemia. Age ≥10 years (OR 19.4, 95% CI: 5.5–68.4), family history of diabetes (OR 8.2, 95% CI: 2.7–25.3), and higher body mass index (BMI) (OR 1.8, 95% CI: 1.1–2.9) were associated with insulin treatment.

Conclusions

Onset of hyperglycemia in children receiving induction chemotherapy for ALL is temporally linked to administration of pegaspargase. Older age, female sex, and family history of diabetes are predictive of hyperglycemia during induction; older age, family history of diabetes, and higher BMI are associated with insulin treatment. Frequent glucose monitoring is indicated during induction therapy for ALL.
Novel epoxy‐based glass fiber reinforced composites containing compatibilized para‐aramid fibers and silanized nanoclay for improved impact strength
Authors: Shelly Daksh , Nanda Tarun , Mehta Rajeev
Published: December 2021

This research developed epoxy‐based glass fiber reinforced composite (GFRPs) containing multi‐scale fiber reinforcement comprising of silanized nanoclay (nano‐reinforcement) and compatibilized para‐aramid (PA) fibers (micro‐reinforcement) for enhanced impact strength and tensile‐flexural properties. VARIM technique was used for fabrication of GFRPs. Surface modification (silanization) of nanoclay was confirmed by FTIR and that of PA fibers was confirmed by SEM‐EDS and FTIR. Dispersion/morphology of nanoclay in the processed nanocomposites was determined by XRD and TEM analysis. Three different methods were used for the compatibilization of PA fibers. All methods exhibited a substantial increase in impact strength without a decrease in flexural/tensile strength. Nanocomposite containing 1.0 phr MAH treated PA fibers and 2 phr silanized nanoclay showed the highest improvement in impact strength (34% higher than the reference composite) along with minor improvements in tensile strength (6%), and flexural modulus (13%). SEM micrographs of the fractured surface of impact test samples were used to identify the mechanisms/reasons for the improved mechanical performance of the newly developed GFRPs.
High time resolution measurement of solar irradiance onto driving car body for vehicle integrated photovoltaics
Authors: Wetzel Gustav , Salomon Leon , Krügener Jan , Bredemeier Dennis , Peibst Robby
Published: December 2021

Vehicle integrated photovoltaic (VIPV) systems have much different requirements on maximum power tracking compared to stationary setups. The occurrence of fast changes between full irradiance and shading are demanding. To evaluate the specific impact of these conditions on the specifications of VIPV systems, we conduct high resolution measurements of the incident irradiance onto a car body while driving. We investigate the influence of environmental conditions like weather, season and building density in an urban environment on measured irradiance on the roof and the sides of a vehicle. We find that weather conditions have the highest impact on the measured irradiance on the roof, while the relative irradiance on the side depends more heavily on the season. We also find that changes in irradiance occur predominantly at frequencies below 1 Hz, but changes with 100 Hz or more can occur in certain situations, with a tendency toward higher frequencies for sunny weather. This must be considered in maximum power point tracker design.
Phlegmatization of TATP and HMTD with Activated Charcoal as Training Aid for Explosive Detection Dogs
Authors: Wilhelm Isabel , Bikelytė Greta , Wittek Michael , Härtel Martin Andreas Christian , Röseling Dirk , Klapötke Thomas Matthias
Published: December 2021

Both TATP and HMTD could be phlegmatized by coprecipitation with active charcoal resulting in mixtures with a nominal content of 40 wt‐% (d40‐TATP) and 10 wt‐% (d10‐HMTD), respectively. In terms of impact and friction sensitivity for both peroxides a content of 40 wt‐% resulted in >30 Nm impact sensitivity and >360 N friction sensitivity. Both phlegmatized peroxides passed the Koenen Tube and Thermal Stability Test according to the UN recommendation on the transport of dangerous goods test manual. Investigations with a process mass spectrometer indicate that d40‐TATP can produce a saturated TATP headspace at least in the same time as the same amount of pure TATP. Measurements with the transpiration method demonstrated that the vapor pressure
at 298.15 K of d40‐TATP (2.3 Pa) and d32.7‐TATP (0.9 Pa) is lower than that of pure TATP (6.7 Pa). Headspace SPME‐GC/MS measurements revealed that the active charcoal does not contribute to the vapor profile of the training aid. Both d40‐TATP and d10‐HMTD were tested as training aids for explosive detection dog teams (EDD). In both differentiation track and realistic environment scenarios a detection rate of 100 % could be achieved by German Federal Police EDD with a false positive rate of solely 3 %.
Quantum Mechanical Investigation on Decomposition Pathways of BuNENA
Authors: Shim Hong‐Min , Kim Sung June , Park Young Chul , Min Byoung Sun
Published: December 2021

The unimolecular decomposition pathways of n‐butyl nitroxyethylnitramine (BuNENA) were computationally investigated. The O−NO2 bond dissociation energies (BDEs) are found to be smaller than the N−NO2 BDEs. The consecutive NO2 elimination via TSA1 is more favorable kinetically than that via TSA2 although both of them form the same intermediate of n‐butyl‐aminoacetaldehyde (BuAAA). Isomerization of n‐butyl‐nitramineethyloxidanyl radical (BuNEȮ) formed by homolytic cleavage of O−NO2 bond was found to eliminate NO2 with a negative bond dissociation energy. Among the NO2 elimination pathways, the formation of C4H9NCH2 (PB2b), CH2O, and NO2 from BuNEȮ via the saddle point TSB2a was found to be the most kinetically favorable with a low activation energy barrier. In contrast, the consecutive HONO elimination is the most thermodynamically favorable with a high exothermicity (−▵H0). The first‐principle kinetic Monte Carlo (kMC) simulations show that the NO2 elimination of BuNEȮ via TSB2a plays an important role in driving the decomposition of BuNENA.
Influence of Magnesium Doping on the Photocatalytic and Antibacterial Properties of Hematite Nanostructures
Authors: Joseph Julie Ann , Nair Sinitha B. , Mary Surya A. , John Sareen Sarah , Shaji Sadasivan , Philip Rachel Reena
Published: December 2021

Herein, the effect of magnesium doping on hematite nanostructures prepared by a simple and cost‐effective electrochemical method is reported. Photocatalytic and antibacterial studies on the undoped and doped samples suggest improved performance for the Mg‐doped samples. Structural studies using X‐ray diffraction, Raman spectroscopy, and X‐ray photoelectron spectroscopy (XPS) in combination with field‐emission scanning electron microscopy for surface morphology confirm the Mg presence in the nanostructured hematite phase of iron oxide. Analyses of the valence band (VB) XPS spectra along with optical reflectance spectra indicate a shift in VB edge, characteristic of a conductivity type conversion from n‐type in hematite to p‐type in Mg‐doped hematite. The room temperature electrical conductivity is increased by three orders, and the optical bandgap is reduced by around 0.08 eV for moderately doped hematite nanostructures.
Outlier‐robust set‐membership estimation for discrete‐time linear systems
Authors: Chen Aijun , Ngoc Dinh Thach , Raïssi Tarek , Shen Yi
Published: December 2021

In many industrial applications, physical equipment for measuring may suffer from transient malfunctions, which can cause data outliers. This article addresses the problem of guaranteed set‐membership estimation of uncertain linear systems subject to outliers in measurements. To solve this problem, a robust set‐membership estimator is designed using the forward‐backward contraction procedure and a zonotopic filter. The setting up of these techniques offers two main advantages. On the one hand, outliers can be identified and discarded, which helps to resume the guaranteed property and avoid deadlock situations. On the other hand, the proposed method uses set‐inversion to fuse the available historical data, so as to attenuate the effect of uncertainties. Numerical examples are provided to show the efficiency of the proposed estimator.
On the role of feature and signal selection for terrain learning in planetary exploration robots
Authors: Ugenti Angelo , Vulpi Fabio , Domínguez Raúl , Cordes Florian , Milella Annalisa , Reina Giulio
Published: December 2021

Increasing the terrain awareness of planetary exploration rovers is one key technology for future space robotics to successfully accomplish long‐distance and long‐duration missions. In contrast to most of the existing algorithms that use visual or depth data for terrain classification, the approach presented in this study tackles the problem using proprioceptive sensing, for example, vibration or force measurements. The underlying assumption is that these signals, being directly modulated by the terrain properties, are well descriptive of a given surface. Therefore, terrain signature can be inferred via learning algorithms that are trained on either the signals directly or a signal‐derived feature set. Following the latter approach, first, a physics‐based signal augmentation process is presented that aims at maximizing the information content. Then, a feature selection algorithm based on a scoring system and an iterative search is developed to decrease the computational cost while preserving high classification accuracy. The resulting most informative feature subspace can be used to train a support vector machine (SVM) classifier. For comparison, the time histories of the selected proprioceptive signals are used to train a deep convolutional neural network (CNN). Results obtained from real experiments using the SherpaTT rover confirm that proprioceptive sensing is effective in predicting terrain type with an accuracy higher than 90% for both algorithms in generalization tasks. When the two learning approaches are contrasted in extrapolation problems, for example, predicting observations acquired at previously unseen velocity or terrain, CNN outperforms the standard SVM. Furthermore, CNN holds the additional advantage of learning features automatically from signal spectrograms, reducing the need of a priori knowledge at the expense of higher computational efforts.
Local path planning for autonomous mobile robots by integrating modified dynamic‐window approach and improved follow the gap method
Authors: Hossain Tagor , Habibullah Habibullah , Islam Rafiqul , Padilla Ricardo V.
Published: December 2021

Mobile robots need to automatically generate a safe, goal‐oriented, and fast collision‐free trajectory in real‐time during the movement in an indoor/outdoor environment. A planned trajectory must be adaptable and drivable with environmental changes where various static and moving obstacles may be present. The ultimate goal of a robot is to reach the destination without hitting any obstacles, therefore, a reactive local path planning algorithm is needed. In this paper, a novel local algorithm is proposed by integrating dynamic window approach (DWA) and improved follow the gap method (IFGM) to generate a collision‐free trajectory for a mobile robot which is capable to avoid any moving obstacles presenting in the surrounding environment. In this proposed method, first, a safety distance is maintained according to the relative position of obstacles and the robot. Moreover, find a feasible gap to direct the robot toward the desired goal. Besides, the heading angle is calculated to change the direction of the robot for avoiding collision with nearby obstacles. After that, calculate the appropriate velocity for the robot. Finally, a robust, safe, and goal‐directed trajectory is generated which does not suffer from global convergence and local minima problems. The performance and effectiveness of this proposed algorithm are evaluated by experimental results.