bluuebunny/crossref_metadata_2025 huggingface dataset:
Deep learning‐based classification of preclinical breast cancer tumor models using chemical exchange saturation transfer magnetic resonance imaging
Authors: Bie Chongxue , Li Yuguo , Zhou Yang , Bhujwalla Zaver M. , Song Xiaolei , Liu Guanshu , van Zijl Peter C. M. , Yadav Nirbhay N.
Published: October 2021

Chemical exchange saturation transfer (CEST) magnetic resonance imaging has shown promise for classifying tumors based on their aggressiveness, but CEST contrast is complicated by multiple signal sources and thus prolonged acquisition times are often required to extract the signal of interest. We investigated whether deep learning could help identify pertinent Z‐spectral features for distinguishing tumor aggressiveness as well as the possibility of acquiring only the pertinent spectral regions for more efficient CEST acquisition. Human breast cancer cells, MDA‐MB‐231 and MCF‐7, were used to establish bi‐lateral tumor xenografts in mice to represent higher and lower aggressive tumors, respectively. A convolutional neural network (CNN)‐based classification model, trained on simulated data, utilized Z‐spectral features as input to predict labels of different tissue types, including MDA‐MB‐231, MCF‐7, and muscle tissue. Saliency maps reported the influence of Z‐spectral regions on classifying tissue types. The model was robust to noise with an accuracy of more than 91.5% for low and moderate noise levels in simulated testing data (SD of noise less than 2.0%). For in vivo CEST data acquired with a saturation pulse amplitude of 2.0 μT, the model had a superior ability to delineate tissue types compared with Lorentzian difference (LD) and magnetization transfer ratio asymmetry (MTRasym) analysis, classifying tissues to the correct types with a mean accuracy of 85.7%, sensitivity of 81.1%, and specificity of 94.0%. The model's performance did not improve substantially when using data acquired at multiple saturation pulse amplitudes or when adding LD or MTRasym spectral features, and did not change when using saliency map‐based partial or downsampled Z‐spectra. This study demonstrates the potential of CNN‐based classification to distinguish between different tumor types and muscle tissue, and speed up CEST acquisition protocols.
Racist connotations in xenophobic outbreaks: An Afrocentric evaluation
Authors: Montle Malesela Edward
Published: October 2021

The democratic jurisdiction in Africa meant to re‐instil peace in the continent, unite her people and champion the philosophy of Ubuntu. It has endeavoured to eradicate the enduring legacies of colonial hegemony and assert a new identity distinguished by autonomous ideologies. Despite the dispensation of these efforts, African societies are still bedevilled by colonial fragments. This is evinced by the appalling racist undertones and xenophobic spells that are overbearing in Africa in the democratic wave. Today, the African continent is vexed by the increasing rate of xenophobic outbreaks that sometimes appear to be anchored in racist connotations. This, inter alia, menaces African humanism and social development in African societies. This qualitative paper has aimed to uproot racist precipitants in xenophobic attacks. It is theoretical in nature and evaluates the rapport between racism and xenophobia from an Afrocentric perspective. The study has found that the xenophobic sentiments in the present day are framed within the imaginings of race. It has illuminated racial identity as a catalyst for xenophobia.
A randomized double‐blind placebo‐controlled trial of the effectiveness of melatonin on neurocognition and sleep in survivors of childhood cancer
Authors: Lubas Margaret M. , Mandrell Belinda N. , Greene William L. , Howell Carrie R. , Christensen Robbin , Kimberg Cara I. , Li Chenghong , Ness Kirsten K. , Srivastava Deo Kumar , Hudson Melissa M. , Robison Leslie L. , Krull Kevin R. , Brinkman Tara M.
Published: October 2021

Background

Adult survivors of childhood cancer are at risk of developing sleep and neurocognitive problems, yet few efficacious interventions exist targeting these prevalent late effects. Melatonin has known sleep‐promoting effects; however, it has not been well studied among childhood cancer survivors.

Method

Survivors (n = 580; mean age = 33.5 years; 26 years post‐diagnosis) from the St. Jude Lifetime Cohort were randomized (1:1) to a six‐month double‐blind placebo‐controlled trial of 3 mg time‐release melatonin within three strata (stratum 1: neurocognitive impairment only; stratum 2: neurocognitive and sleep impairment; stratum 3: sleep impairment only). Neurocognitive performance was assessed at baseline and post‐intervention using standardized measures. Sleep was assessed via self‐report and actigraphy. Independent samplettests compared mean change scores from baseline to six months. Post‐hoc analyses compared the prevalence of clinically significant treatment responders among melatonin and placebo conditions within and across strata.

Results

Intent‐to‐treat analyses revealed no statistically significant differences in neurocognitive performance or sleep from baseline to post‐intervention. However, among survivors with neurocognitive impairment only, a larger proportion randomized to melatonin versus placebo demonstrated a treatment response for visuomotor speed (63% vs 41%,P = 0.02) and nonverbal reasoning (46% vs 28%,P = 0.04). Among survivors with sleep impairment only, a larger proportion treated with melatonin demonstrated a treatment response for shifting attention (44% vs 28%,P = 0.05), short‐term memory (39% vs 19%,P = 0.01), and actigraphy‐assessed sleep duration (47% vs 29%,P = 0.05).

Conclusion

Melatonin was not associated with improved neurocognitive performance or sleep in our intent‐to‐treat analyses; however, a subset of survivors demonstrated a clinically significant treatment response.
A comparative study on thermal conductivity and permittivity of composites based on linear low‐density polyethylene and poly(lactic acid) filled with hexagonal boron nitride
Authors: Lebedev Sergey M.
Published: October 2021

Thermal conductivity (λ) and permittivity (ε′) of polymer composites based on linear low‐density polyethylene (LLDPE) and poly(lactic acid) (PLA) filled with hexagonal boron nitride (hBN) were considered in this work. It is found that all developed composites possess dielectric properties and enhancement thermal conductivity compared with neat polymer matrices. Unlike carbonaceous materials (carbon black, graphite, graphene, carbon nanotubes), hBN is a good insulator and is therefore more applicable as a filler for heat‐releasing materials with a purely white appearance. At the same time, both LLDPE/hBN and PLA/hBN composites at 40 wt% filler content possess the comparable value of λ about 0.7 W/(m K), which is almost 95% and 250% higher than those for the neat LLDPE and PLA, respectively.
A comparative study of the interaction between the dried ink layer andPLAfilm used for packaging purposes
Authors: Izdebska‐Podsiadły Joanna , Samoraj Marta , Blachowski Konrad , Markowski Leszek , Godlewski Henryk , Dąbrowa Tomasz , Żołek‐Tryznowska Zuzanna
Published: October 2021

This research aims at comparing the interactions between the water‐based printing ink and polylactide (PLA) printing base. As a reference base, a polyethylene terephthalate (PET) film was chosen. The wettability of both films was investigated. The Owens–Wendt method was applied to calculate the surface free energy (SFE). The values of SFE and its polar and dispersive components were compared with the surface tension (ST) of the ink and the polar and dispersive components of ST. The wetting envelopes of the investigated PLA and PET films are presented. Finally, the bonding strength between the dried ink layer and the printing base was analyzed. The PET film exhibited higher values of SFE. However, the bonding strength between the dried ink layer and the printing base was higher for PLA films. Our results reveal that PLA films can be an excellent choice as packaging materials, with comparable or even better print quality than conventional fossil‐based plastics.
Comparative proteomics of thylakoids from Arabidopsis grown in laboratory and field conditions
Authors: Flannery Sarah E. , Pastorelli Federica , Wood William H. J. , Hunter C. Neil , Dickman Mark J. , Jackson Philip J. , Johnson Matthew P.
Published: October 2021

Compared to controlled laboratory conditions, plant growth in the field is rarely optimal since it is frequently challenged by large fluctuations in light and temperature which lower the efficiency of photosynthesis and lead to photo‐oxidative stress. Plants grown under natural conditions therefore place an increased onus on the regulatory mechanisms that protect and repair the delicate photosynthetic machinery. Yet, the exact changes in thylakoid proteome composition which allow plants to acclimate to the natural environment remain largely unexplored. Here, we use quantitative label‐free proteomics to demonstrate that field‐grown Arabidopsis plants incorporate aspects of both the low and high light acclimation strategies previously observed in laboratory‐grown plants. Field plants showed increases in the relative abundance of ATP synthase, cytochrome b6f, ferredoxin‐NADP+ reductases (FNR1 and FNR2) and their membrane tethers TIC62 and TROL, thylakoid architecture proteins CURT1A, CURT1B, RIQ1, and RIQ2, the minor monomeric antenna complex CP29.3, rapidly‐relaxing non‐photochemical quenching (qE)‐related proteins PSBS and VDE, the photosystem II (PSII) repair machinery and the cyclic electron transfer complexes NDH, PGRL1B, and PGR5, in addition to decreases in the amounts of LHCII trimers composed of LHCB1.1, LHCB1.2, LHCB1.4, and LHCB2 proteins and CP29.2, all features typical of a laboratory high light acclimation response. Conversely, field plants also showed increases in the abundance of light harvesting proteins LHCB1.3 and CP29.1, zeaxanthin epoxidase (ZEP) and the slowly‐relaxing non‐photochemical quenching (qI)‐related protein LCNP, changes previously associated with a laboratory low light acclimation response. Field plants also showed distinct changes to the proteome including the appearance of stress‐related proteins ELIP1 and ELIP2 and changes to proteins that are largely invariant under laboratory conditions such as state transition related proteins STN7 and TAP38. We discuss the significance of these alterations in the thylakoid proteome considering the unique set of challenges faced by plants growing under natural conditions.
Proteomic and electron microscopy study of myogenic differentiation of alveolar mucosa multipotent mesenchymal stromal cells in three‐dimensional culture
Authors: Saburina Irina N. , Kosheleva Nastasia V. , Kopylov Arthur T. , Lipina Tatiana V. , Krasina Marina E. , Zurina Irina M. , Gorkun Anastasiya A. , Girina Svetlana S. , Pulin Andrey A. , Kaysheva Anna L. , Morozov Sergey G.
Published: October 2021

Myocyte differentiation is featured by adaptation processes, including mitochondria repopulation and cytoskeleton re‐organization. The difference between monolayer and spheroid cultured cells at the proteomic level is uncertain. We cultivated alveolar mucosa multipotent mesenchymal stromal cells in spheroids in a myogenic way for the proper conditioning of ECM architecture and cell morphology, which induced spontaneous myogenic differentiation of cells within spheroids. Electron microscopy analysis was used for the morphometry of mitochondria biogenesis, and proteomic was used complementary to unveil events underlying differences between two‐dimensional/three‐dimensional myoblasts differentiation. The prevalence of elongated mitochondria with an average area of 0.097 μm2 was attributed to monolayer cells 7 days after the passage. The population of small mitochondria with a round shape and area of 0.049 μm2 (p < 0.05) was observed in spheroid cells cultured under three‐dimensional conditions. Cells in spheroids were quantitatively enriched in proteins of mitochondria biogenesis (DNM1L, IDH2, SSBP1), respiratory chain (ACO2, ATP5I, COX5A), extracellular proteins (COL12A1, COL6A1, COL6A2), and cytoskeleton (MYL6, MYL12B, MYH10). Most of the Rab‐related transducers were inhibited in spheroid culture. The proteomic assay demonstrated delicate mechanisms of mitochondria autophagy and repopulation, cytoskeleton assembling, and biogenesis. Differences in the ultrastructure of mitochondria indicate active biogenesis under three‐dimensional conditions.
Antibiotic use and associated factors in adult outpatients from 2000 to 2019
Authors: Franchi Carlotta , Mandelli Sara , Fortino Ida , Nobili Alessandro
Published: October 2021

The aims of the study were to assess the changes in 19‐years use of antibiotics (overall, by age, sex and geographical area) and of those classes deemed to be quality indicators for their consumption and to evaluate factors associated to antibiotic use. We analyzed drug prescription data collected in the administrative database of the Lombardy Region (Northern Italy) for outpatients aged 40+ years from 2000 to 2019. Logistic regression analyses were performed to evaluate the association between receiving at least one antibiotic prescription and year of observation, gender, age groups, area of residence, polypharmacy and hospitalizations in the index year. The prevalence of patients prescribed with antibiotics remained high from 2000 (33.8%) to 2019 (32.6%). Prevalence of use of second‐line choice antibiotics (penicillin combinations with beta‐lactamase inhibitors, third and fourth generation cephalosporins, macrolides) continued to increase, only fluoroquinolones decreased in 2019 (19%) comparing to 2018 (26%), at the time when the Italian Medicines Agency promulgated safety warnings. Females (OR 1.28, 95%CI 1.27–1.28), people living in Brescia (OR 1.24, 95%CI 1.24–1.25), those exposed to polypharmacy (OR 2.57, 95%CI 2.56–2.57) and those hospitalized 1 to 3 (OR 1.86, 95%CI 1.85–1.86) or more than 3 (OR 2.02, 95%CI 2.01–2.03) times a year had a statistically significant higher risk of receiving antibiotics. The high use of antibiotics over the study period further reinforces the need of impactful interventions, in order to improve the rational use of antibiotics and to reduce the risks of antimicrobial resistance. The differences outlined should be considered when monitoring and planning these interventions.
Photobleaching Effect on the Radiation‐Induced Attenuation of an Ultralow Loss Optical Fiber at Telecommunication Wavelengths
Authors: Campanella Cosimo , Morana Adriana , De Michele Vincenzo , Vidalot Jeoffray , Marin Emmanuel , Boukenter Aziz , Ouerdane Youcef , Paillet Philippe , Girard Sylvain
Published: October 2021

An unexpected high sensitivity to radiation has recently been discovered in a new generation of ultralow loss pure‐silica core optical fiber, the Corning Vascade EX1000. It is investigated how the injected power level of the probing signal at 1310 and 1550 nm affects the radiation‐induced attenuation (RIA) during and after steady‐state X‐ray exposure up to a total ionizing dose (TID) of 250 kGy (SiO2) at room temperature. The experiments confirm this fiber's high sensitivity to radiations, mainly due to the generation of metastable defects absorbing in the infrared domain. RIA kinetics are characterized by a non‐monotonic behavior, reaching a maximum of the radiation‐induced losses at 3.3 kGy (SiO2). Through successive radiation tests, the RIA dependence on the signal power level at the dose corresponding to the maximum of the RIA is studied, finding out that, for the two investigated wavelengths, the RIA follows a power law dependence in the 100 nW–1 mW injected power range, whose exponent seems independent on the dose rate (between 1 and 6 Gy s−1). The results highlight a clear photobleaching phenomenon, with the RIA associated to these metastable defects strongly reduced at higher injected powers of mW levels.
The oriented swap process and last passage percolation
Authors: Bisi Elia , Cunden Fabio Deelan , Gibbons Shane , Romik Dan
Published: October 2021

We present new probabilistic and combinatorial identities relating three random processes: the oriented swap process (OSP) on n particles, the corner growth process, and the last passage percolation (LPP) model. We prove one of the probabilistic identities, relating a random vector of LPP times to its dual, using the duality between the Robinson–Schensted–Knuth and Burge correspondences. A second probabilistic identity, relating those two vectors to a vector of “last swap times” in the OSP, is conjectural. We give a computer‐assisted proof of this identity for after first reformulating it as a purely combinatorial identity, and discuss its relation to the Edelman–Greene correspondence. The conjectural identity provides precise finite‐n and asymptotic predictions on the distribution of the absorbing time of the OSP, thus conditionally solving an open problem posed by Angel, Holroyd, and Romik.
MOVER confidence intervals for a difference or ratio effect parameter under stratified sampling
Authors: Tang Yongqiang
Published: October 2021

Stratification is commonly employed in clinical trials to reduce the chance covariate imbalances and increase the precision of the treatment effect estimate. We propose a general framework for constructing the confidence interval (CI) for a difference or ratio effect parameter under stratified sampling by the method of variance estimates recovery (MOVER). We consider the additive variance and additive CI approaches for the difference, in which either the CI for the weighted difference, or the CI for the weighted effect in each group, or the variance for the weighted difference is calculated as the weighted sum of the corresponding stratum‐specific statistics. The CI for the ratio is derived by the Fieller and log‐ratio methods. The weights can be random quantities under the assumption of a constant effect across strata, but this assumption is not needed for fixed weights. These methods can be easily applied to different endpoints in that they require only the point estimate, CI, and variance estimate for the measure of interest in each group across strata. The methods are illustrated with two real examples. In one example, we derive the MOVER CIs for the risk difference and risk ratio for binary outcomes. In the other example, we compare the restricted mean survival time and milestone survival in stratified analysis of time‐to‐event outcomes. Simulations show that the proposed MOVER CIs generally outperform the standard large sample CIs, and that the additive CI approach performs better than the additive variance approach. Sample SAS code is provided in the Supplementary Material.
Microwave‐Assisted Production of 5‐Hydroxymethylfurfural from Glucose
Authors: Mason Jameson Brett , Sun Yujie
Published: October 2021

Among many biomass‐derived intermediate compounds, 5‐hydroxymethylfurfural (HMF) has been regarded as a platform chemical because it can be used to produce numerous valuable products. However, the difficulty of HMF isolation from reaction media coupled with its poor stability have significantly inhibited its large‐scale production and application. In this work, we report a single‐step process for the direct production of HMF from glucose using green chemical methods. Optimized glucose isomerization and dehydration under microwave irradiation achieved a respectable HMF yield (70 %) using a biphasic solvent mixture (water/THF), high glucose concentration (30 % w/v), catalytic amounts of AlCl3 (5 mol%) and HCl (15 mol%). The reaction can be completed within minutes at 165 °C. Overall, our microwave‐assisted strategy enables the direct conversion of commercially available glucose to the highly valuable platform chemical HMF without the use of expensive solvents or catalysts, suggesting an economically attractive approach for upgrading carbohydrates.
A Flexible Asymmetric NaFePO4/Carbon Cloth Supercapacitor Using Crosslinked Polyacrylate Gel as Electrolyte
Authors: Quan Yufei , Wang Sumin , Liu Pan , Shen Zhiruo , Wang Qiguan
Published: October 2021

With the development of light‐weight and bendable electric devices, nowdays, solid‐state supercapacitive devices have attracted great attention, in which the classic polymeric electrolytes such as polyvinyl alcohol and polyethylene oxide copolymers are generally used. However, the microphase separation in these polymers and low conductivity affect the ions transfer and the energy‐storage performance. In this work, a crosslinked sodium polyacrylate gel (NaPA) is synthesized to replace conventional polymeric electrolyte. Because NaPA is a kind of polymeric salt which has high native degree of ionization in water, the NaPA gel shows low resistance to ion transportation. By using NaPA gel as the electrolyte and carbon cloth as current collector, a flexible solid asymmetric supercapacitor assembled by positive NaFePO4/carbon cloth and negative activated carbon/carbon cloth electrode shows the maximum capacitance of 46.33 mF cm−2 at 1 mA cm−2, with a high stability of 87.33 % retention during 5000 charge and discharge cycles. Moreover, this flexible asymmetric supercapacitors showed nearly unchanged capacitance under different bending angles. It is found that the Na+ diffusion coefficient in NaFePO4/CC//NaPA supercapacitor is 8.05×10−14 cm2 ⋅ s, remarkable higher than CC//NaPA and NaFePO4/CC//PVA. The high diffusion coefficient and low resistance of NaPA lead to excellent capacitave performance of NaFePO4/CC//NaPA, delivering a good application prospect.
Catechol‐ and Phenol‐Containing Thio‐Schiff Bases: Synthesis, Electrochemical Properties and Biological Evaluation
Authors: Smolyaninov Ivan V. , Burmistrova Daria A. , Arsenyev Maxim V. , Almyasheva Nailya R. , Ivanova Ekaterina S. , Smolyaninova Susanna A. , Pashchenko Konstantin P. , Poddel'sky Andrey I. , Berberova Nadezhda T.
Published: October 2021

A number of novel catechol‐ and phenol‐containing Schiff bases with thiophenol or mercaptobenzimidazole groups have been synthesized. Electrochemical studies of the target compounds were carried out in order to establish the primary centres involved in redox reactions, and the mechanism of oxidative transformations. The antioxidant activities of the compounds were determined using different assays. Compounds combining the catechol group with the mercaptobenzimidazole or benzothiazoline cycles exhibit more pronounced antioxidant activity in the concerning tests. However, a significant promoting effect on the process of lipid peroxidation of rat brain homogenates was found in the presence of catechols. Antibacterial and cytotoxic effects of Schiff bases can be caused by the possibility of ROS and o‐benzoquinones generation. It was established that some compounds have a moderate bacteriostatic effect against Staphylococcus aureus strains. Schiff bases with catechol and heterocyclic groups exhibit a good antiproliferative activity (IC50<10 μM) towards MCF‐7, HTC‐116 and A549 cell lines.
Fabrication of Highly Catalytically Active Gold Nanostructures on Filter‐Paper and Their Applications towards Degradation of Environmental Pollutants
Authors: Khan Ghazanfar Ali , Esentürk Emren Nalbant , Bek Alpan , Bhatti Arshad Saleem , Ahmed Waqqar
Published: October 2021

Supported metallic nanoparticles (NPs) have recently become a promising candidate for the degradation of environmental pollutants. In this work, we report the fabrication of highly catalytically active, surfactant‐free interconnected Au nanostructures directly on filter paper. The width of nanostructures is only a few nanometers and they contain high concentration of low‐coordination atoms. Our approach involves the immersion and evaporation of Au precursor solution on the filter paper and its subsequent reduction. This approach generates filter paper‐based gold substrates (FPGS) not only in a simple and straightforward fashion that can be executed in a matter of minutes but can also be easily scaled up for large‐scale production. Owing to their surfactant‐free nature, FPGS are well suited for the degradation of both cationic and anionic dyes by providing large unhindered surface for dye adsorption. The FPGS were able to completely degrade methyl orange (MO) and methylene blue (MB) dyes and also showed excellent reusability and stability.
Ethylene Hydroformylation with Carbon Dioxide Catalyzed by Ruthenium Supported on Titanate Nanotubes: Infrared Spectroscopic Evidence of Surface Species
Authors: Chavez‐Mulsa Alejandra , Fierro‐Gonzalez Juan C. , Handy Brent E. , Santos‐López Iván Alonso , Jimenez‐Lam Sergio Aarón , De Haro Del Río David A. , De la Rosa Javier Rivera , Flores‐Escamilla Gerardo Antonio
Published: October 2021

Ru nanoparticles supported on titanate nanotubes (Ru/TiNT) were catalytically active in the ethylene hydroformylation using CO2 as reactant (at atmospheric pressure and moderate temperatures) to give propanal and ethane. The rate of propanal formation at 100 °C with a molar feed ratio of 1 : 1 : 1 : 8 (CO2 : C2H4 : H2 : Ar) was 0.128 molpropanal molRu−1 h−1. Raman spectra and X‐ray diffraction data characterizing the catalyst confirmed the presence of the crystalline structure of Na2Ti3O7 for TiNT, whereas transmission electron microscopy (TEM) images evidenced its tubular morphology and the presence of finely dispersed Ru nanoparticles with an average diameter of 0.8 nm. Infrared spectra measured under reaction conditions allowed the identification of surface species that participate in the catalysis, namely CO bonded to the Ru nanoparticles, Ru‐ethyl and Ru‐acyl species and adsorbed propanal. The data show that conversion of CO2 to CO was crucial for the formation of the Ru‐acyl species, regarded as a key reaction intermediate to give propanal.
Supramolecular Catalyst Functions in Catalytic Amount: Cucurbit[7]uril Accelerates Click Reaction in Water
Authors: Feng Xuepu , Zhao Fen , Qian Rui , Guo Mengbi , Yang Jing , Yang Rui , Meng DongLing
Published: October 2021

Macrocycles have garnered significant interest for their potential utility as supramolecular catalysts in modulating chemical transformations. Here, we report a reusable supramolecular catalytic system to accelerate copper(I) catalyzed Click cycloaddition (CuAAC) reactions in water. Our system comprises of 5 mol % CuI and 0.5 mol % of the supramolecular co‐catalyst, cucurbit[7]uril (CB7), which stabilizes and prevents the oxidation of CuI. This catalysis can be cycled is that the triazole product or alkyne reactant hardly bind in the cavity of CB7 while there is an interaction between azide reactant and CB7 through molecular recognition. The dual catalysts can be facilely separated from the reaction system. As a result, the catalyst system can be recycled and reused for more than 10 consecutive cycles while maintaining high catalytic activity.
Unveiling the Substituent Effects in the Stereochemistry of [3+2] Cycloaddition Reactions of Aryl‐ and Alkyldiazomethylphosphonates with Norbornadiene within a MEDT Perspective
Authors: Domingo Luis R , Acharjee Nivedita
Published: October 2021

The [3+2] cycloaddition (32CA) reactions of norbornadiene with aryl and alkyl substituted diazomethylphosphonates (SDAPs) have been studied within the molecular electron density theory (MEDT). Electron localization function (ELF) shows the presence of apseudoradicalC3 center at the alkyl SDAPs, classifying them aspseudo(mono)radicalspecies, while the aryl SDAP is classified as a zwitterionic one, owing to the delocalization of the C3 electron density on the C3‐P bond. These 32CA reactions present high activation enthalpies in dichloromethane, between 17.3 and 21.6 kcal mol−1, being strongly exothermic by more than 33.8 kcal mol−1. While these 32CA reactions present a totalsynfacial selectivity, theendo/exostereoselectivity depends on the steric hindrance caused by the bulk substituents present in these SDAPs along the approach to norbornadiene. Interestingly the phenyl group provokes a lesser hindrance than that of the small methyl group, justifying the 95 % ofexostereoselectivity experimentally observed. ELF and the AIM (Atoms‐in‐Molecules) analyses account for the bonding changes along these 32CA reactions. The energy cost for the rupture of the norbornadiene C−C and that of the SDAPs N−N double bonds are the major contributors to the activation energies of these non‐polar 32CA reactions.
Synthesis of 2′‐Deoxy‐2′‐fluoro‐L‐cytidine and Fluorinated L‐Nucleic Acids for Structural Studies
Authors: Dantsu Yuliya , Zhang Ying , Zhang Wen
Published: October 2021

The unique properties of fluorine atom on nucleic acid backbone can offer stricking functional and structural features. In order to extend the biological applications of L‐type nucleic acid, we chemically incorporate the fluoro‐modification into 2′‐position of L‐cytidine, and obtain a series of fluoro‐modified L‐DNAs/ L‐RNAs. Our melting study indicates that the 2′‐fluoro‐modification does not disrupt the thermostabilities of wild‐type L‐nucleic acids. Consistently, our X‐ray crystal structure reveals that fluoro‐moiety cause no structural perturbation, and the fluoro‐L‐cytidine forms the Watson‐Crick base pair with L‐guanosine virtually identical to nonmodified L‐type CG pair. This fluoro‐modified cytidine provides a useful biochemical strategy to investigate L‐nucleic acid as advanced molecular therapy.
On the Interaction of Surfactants with Gallium‐Based Liquid Metals
Authors: Handschuh‐Wang Stephan , Rauf Muhammad , Gan Tiansheng , Shang Wenhui , Zhou Xuechang
Published: October 2021

Liquid metals have aroused interest in the scientific communities of electronics, engineering and biomedicine. In particular, the stabilization of liquid metal nanodroplets by surfactants and macromolecules has been investigated in the past extensively. Herein, we investigate the change in interfacial tension of the liquid metal Galinstan in contact with aqueous electrolytes upon addition of surfactants in aqueous solutions. We show that is governed by the chemical environment, the structure of the electric double layer (EDL) and the surfactant charge. In most environments a critical micelle concentration (CMC) can be determined, the value of which is in favorable agreement with literature values. Furthermore, based on the selective adsorption of the surfactant, the structure of the EDL is predicted and discussed, and the adsorption of surfactants is employed to mitigate liquid metal droplet coalescence. In this regard, the data suggests that the packing parameter, change in IFT upon surfactant addition and charge density of EDL are the main contributors for liquid metal droplet stability.
Synthesis of Dumbbell‐Like DBATT Dimers**
Authors: Feofanov Mikhail , Lungerich Dominik , Akhmetov Vladimir , Amsharov Konstantin
Published: October 2021

Two‐dimensional acenes are promising candidates for applications in single‐molecule spectroscopy due to the electronic properties caused by their zig‐zag periphery. However, synthetic access to their dimers remains unexplored because of low solubility and reduced stability. Herein we report a facile approach towards two‐dimensional acenes dimers on the example of 2.3,8.9‐dibenzanthanthrene (DBATT) connected via rigid linker. The exploitation of dehydrative π‐extension on the last step of the synthesis allows avoiding difficulties connected with cumbersome purification of low soluble products. The technique was shown to be applicable for the synthesis of DBATT dimers connected rigidly with conjugated and non‐conjugated linkers, containing alternating para‐phenylene and bicyclo[2.2.2]octane moieties.
Highly Poison‐Resistant Single‐Atom Co–N4 Active Sites with Superior Operational Stability over 460 h for H2S Catalytic Oxidation
Authors: Lei Ganchang , Tong Yawen , Shen Lijuan , Zheng Yong , Liang Shijing , Lin Wei , Liu Fujian , Cao Yanning , Xiao Yihong , Jiang Lilong
Published: October 2021

Efficient catalytic elimination of hydrogen sulfide (H2S) with high activity and durability in nature gas and blast‐furnace gas is very critical for both fundamental catalytic research and applied environmental chemistry. Herein, atomically dispersed Co atom catalysts with Co–N4 sites that can transform H2S into S with conversion rate of ≈100% are designed and prepared. The representative 4Co‐N/NC achieves a sulfur yield of nearly 100% and TOF(Co) of 869 h–1 at 180 °C. Importantly, remarkable long‐term durability is achieved as well, with no obvious loss of catalytic activity in the run of 460 h, outperforming most of the reported catalysts. The short bond length and strong cooperation of Co–N are beneficial to improve the structural stability of the Co–N4 centers, and significantly enhanced resistance of water and sulfation over single‐atom Co‐catalyst. The present mechanism involves the stepwise hydrogen transfer process via the adsorbed *HOO and *HS intermediates.
Chemical Vapor Deposition Mediated Phase Engineering for 2D Transition Metal Dichalcogenides: Strategies and Applications
Authors: Hernandez Ruiz Karla , Wang Ziqian , Ciprian Matteo , Zhu Meifang , Tu Rong , Zhang Lianmeng , Luo Wei , Fan Yuchi , Jiang Wan
Published: October 2021

2D transition metal dichalcogenides (TMDs) are characterized by the presence of multiple crystal structures or phases, even at the ultrathin limit. Controlling phase transformations, namely, phase engineering, of 2D TMDs is crucial for realizing high‐performance 2D devices by combining phases with distinct physical and chemical properties. As a powerful approach for large‐scale production of high‐quality 2D TMDs, chemical vapor deposition (CVD) offers unique advantages in phase engineering due to its highly controllable synthesis processes. Starting with an introduction of the crystal structures and phase transformations of 2D TMDs, this review summarizes the recent developments in CVD‐mediated phase engineering strategies of TMDs, including control of temperature, precursors, catalysis, atmosphere, composition, and strain during the deposition process. Moreover, the representative applications of CVD‐based phase‐engineered TMDs in the field of transistors, photodetectors, photovoltaic cells, and catalysis are overviewed. Finally, the challenges, expectations of CVD‐based phase engineering, and future development of this versatile technique are discussed.
Structural Regulation of Pd‐Based Nanoalloys for Advanced Electrocatalysis
Authors: Li Menggang , Xia Zhonghong , Luo Mingchuan , He Lin , Tao Lu , Yang Weiwei , Yu Yongsheng , Guo Shaojun
Published: October 2021

Palladium (Pd)‐based materials have attracted increasing attentions as a kind of novel candidate catalysts for many electrocatalytic reactions to replace classic platinum (Pt) catalysts, especially in the fuel cell‐related electrocatalysis. However, the requirement of high activity and stability toward further practical applications makes the development of Pd‐based catalysts cease to advance. Combining alloying and structure‐controlled strategies has well addressed this challenge by optimizing the adsorption/desorption behaviors toward reaction intermediates. Herein, the recent advances of rational structural designs in terms of tuning the dimensionalities of Pd‐based nanoalloys are overviewed. To further enhance the intrinsic electrocatalytic activity, several advanced strategies, including intermetallics, doping, defects, surface, and interface engineering, are presented to engineer the electronic and/or physical properties of Pd‐based electrocatalysts. Using typical electrocatalytic reactions as probes, the significance of structural regulation of Pd‐based nanocrystals on the enhanced electrocatalysis is demonstrated. Finally, several possible trends and challenges for future advanced research directions are presented. It is anticipated that the rational structural regulation can make promising Pd‐based catalysts touch the ceiling of electrocatalytic activity and stability.
Generation of logic designs for efficiently solving ordinary differential equations on field programmable gate arrays
Authors: Bartel Silas , Korch Matthias
Published: October 2021

Ordinary differential equations can be used to describe simulation models. As such, solving these equations is an important task in the high performance computing (HPC) domain. Field programmable gate arrays (FPGAs) are a promising platform, expected to be usable as efficient accelerators for such computations. While the use of hardware description languages (HDLs) can produce very efficient logic designs, their unique concept is hard to adopt for scientists and software engineers. High‐level synthesis (HLS) tools promise faster development, but bear the risk of lower performance and increased resource consumption of the final design. But even when using HLS tools the user still requires specialized knowledge about FPGAs and circuit design. In order to reach a wide adoption of FPGAs in HPC applications, a need for simple to use tools which enable performant designs was identified. This article proposes a framework that is able to automatically generate specific and optimized solver logic from easy to handle configuration files. No manual development, nor special FPGA or programming knowledge is required. To measure the capability of the proposed tool, the performance was evaluated for different solver methods and compared with an alternative hand optimized HLS implementation. The logic generated by this improved approach is up to 43 times faster than its hand optimized HLS counterpart, depending on the solution method.
Dauerhaftigkeit und Robustheit von Schraubenverbindungen bei Kranbahnträgern
Authors: Misiek Thomas , Götz Frank , Volz Michael
Published: October 2021

Der Beitrag behandelt ausgewählte Themen im Zusammenhang mit Schraubenverbindungen bei Kranbahnträgern. Eingangs wird auf das Verhalten der Verbindung beim Anziehen und unter äußerer Beanspruchung eingegangen. Die Bedeutung der Vorspannkraft für die Schraubenverbindung wird diskutiert. Die Vorspannkraftverlusten zugrunde liegenden Mechanismen sowie diesen entgegenwirkende Sicherungsmaßnahmen werden vorgestellt. Im Anschluss werden diese Sicherungsmaßnahmen in kranbahntypischen Schraubenverbindungen beschrieben. Den Abschluss bilden Überlegungen zur Überprüfung der Verbindungen im Zusammenhang mit der Montage und dem Betrieb der Krananlage.
Scissor‐Shaped Photochromic Dyads: Hierarchical Self‐Assembly and Photoresponsive Property
Authors: Tashiro Keigo , Saito Takuho , Arima Hironari , Suda Natsuki , Vedhanarayanan Balaraman , Yagai Shiki
Published: October 2021

Unique relationships between hierarchically organized biological nanostructures and functions have motivated chemists to construct sophisticated artificial nanostructured systems from small and simple synthetic molecules through self‐assembly. As one of such sophisticated systems, we have investigated scissor‐shaped photochromic dyads that can hierarchically self‐assemble into discrete nanostructures showing photoresponsive properties. We synthesized various azobenzene dyads and found that these dyads adopt intramolecularly folded conformation like a closed scissor, and then self‐assemble into toroidal nanostructures by generating curvature. The toroids further organize into nanotubes and further into helical supramolecular fibers depending on the nature of alkyl substituents. All of these nanostructures can be dissociated and reorganized through the photoisomerization of azobenzene units. On the other hand, the introduction of stilbene chromophores instead of azobenzenes leads to one‐dimensional supramolecular polymerization, which upon the intramolecular photocyclization of stilbene chromophores shifts to curved self‐assembly leading to helicoidal fibers with distinct supramolecular chirality.
Evolution of pyrolysis and gasification as waste to energy tools for low carbon economy
Authors: Porshnov Dmitry
Published: October 2021

The paper aims to review the state of the art in the field of pyrolysis and gasification of waste and to identify approaches that can be prospective considering the upcoming transformation of society. The results show that the transition to a circular, low carbon economy will significantly change the composition of municipal wastes, making thermochemical approaches more and more competitive. However, it does not mean that pyrolysis and gasification will outperform incineration in the field of traditional waste to energy. Novel thermochemical waste management approaches must not be viewed as competitors, but rather as the successors of the traditional mass‐burn incineration. The transition to a circular, low carbon economy will result in an emergence of new needs, new products and thus in possibilities of new pyrolysis and gasification‐based business models different from the waste to energy concept. Negative emissions, energy storage, stabilization of renewable grids as well as renewable fuels must be mentioned as examples of such new products. Thus, thermochemical processing technologies should be embedded into the wider concept of circular, low carbon economy as the source of energy for recycling, a technology of tertiary recycling of synthetic polymers and as a way to transform nonrecyclable rejects into fuels, negative emissions, and other marketable products.

This article is categorized under:

Bioenergy > Systems and Infrastructure
Predicting home sale prices: A review of existing methods and illustration of data stream methods for improved performance
Authors: Shi Donghui , Guan Jian , Zurada Jozef , Levitan Alan S.
Published: October 2021

The need for accurate and unbiased assessment of residential real property has always been important not only to financial institutions lending on or holding such assets but also to municipalities that rely on property taxes as their critical source of revenue. The common methodology for predicting residential property sale price is based on traditional multiple regression in spite of known issues. Machine learning methods have been proposed as an alternative approach but the results are far from satisfactory. A review of existing studies and relevant issues can help researchers better assess the pros and cons of the approaches in this important stream of research and move the field forward. This article provides such a review. In our review, we have noticed that common to both the regression‐based methods and machine learning methods are the use of batch‐mode learning. Thus in addition to providing a review of recent research on batch‐based residential property prediction models, this article also explores a new approach to constructing residential property price prediction models by treating past sale records as an evolving data stream. The results of our study show that the data stream approach outperforms the traditional regression method and demonstrate the potential of data stream methods in improving prediction models for residential property prices.

This article is categorized under:

Application Areas > Business and Industry

Technologies > Machine Learning

Technologies > Prediction
The tumor immune microenvironments of HPV+ and HPV− head and neck cancers
Authors: Gameiro Steven F. , Evans Andris M. , Mymryk Joe S.
Published: October 2021

Human papillomaviruses (HPVs) are the etiological agent of a significant, and increasing, fraction of head and neck squamous cell carcinomas (HNSCC)—a heterogenous group of malignancies in the head and neck region. HPV infection accounts for approximately 25% of all cases, with the remainder typically caused by smoking and excessive alcohol consumption. These distinct etiologies lead to profound clinical and immunological differences between HPV‐positive (HPV+) and HPV‐negative (HPV−) HNSCC, likely related to the expression of exogenous viral antigens in the HPV+ subtype. Specifically, HPV+ HNSCC patients generally exhibit better treatment response compared to those with HPV− disease, leading to a more favorable prognosis, with lower recurrence rate, and longer overall survival time. Importantly, a plethora of studies have illustrated that the tumor immune microenvironment (TIME) of HPV+ HNSCC has a strikingly distinct immune composition to that of its HPV− counterpart. The HPV+ TIME is characterized as being immunologically “hot,” with more immune infiltration, higher levels of T‐cell activation, and higher levels of immunoregulation compared to the more immunologically “cold” HPV− TIME. In general, cancers with an immune “hot” TIME exhibit better treatment response and superior clinical outcomes in comparison to their immune “cold” counterparts. Indeed, this phenomenon has also been observed in HPV+ HNSCC patients, highlighting the critical role of the TIME in influencing prognosis, and further validating the use of cancer therapies that capitalize on the mobilization and/or modulation of the TIME.

This article is categorized under:

Cancer > Molecular and Cellular Physiology

Infectious Diseases > Molecular and Cellular Physiology
The promises and challenges of women's colleges: Leadership and equity
Authors: Lewis Abigail Sara
Published: October 2021

Women's colleges have a unique and successful history in fostering women's leadership relying on transformational and feminist leadership frameworks. Yet, their work in creating more inclusive and intersectional campus communities often falls short. This article offers some solutions on how women's colleges can best move forward to advance leadership and equity on campus.
The role of Asian American and Native American Pacific Islander‐Serving Institutions in reframing leadership education
Authors: Gogue Demeturie Toso‐Lafaele , Venturanza Rikka J. , Cuenza‐Uvas Aida , Nguyen Mike Hoa
Published: October 2021

Leadership education within postsecondary institutions has often failed to consider the ways in which Asian Americans and Pacific Islanders (AAPIs) make sense of their leadership identity. This article explores the role that Asian American and Native American Pacific Islander‐Serving Institutions have in fostering AAPI leaders through culturally relevant practices and services that recognize and embrace students’ racial and ethnic backgrounds.
Block Factorization of the Relative Entropy via Spatial Mixing
Authors: Caputo Pietro , Parisi Daniel
Published: October 2021

We consider spin systems in thed-dimensional lattice$${\mathbb Z} ^d$$Zdsatisfying the so-called strong spatial mixing condition. We show that the relative entropy functional of the corresponding Gibbs measure satisfies a family of inequalities which control the entropy on a given region$$V\subset {\mathbb Z} ^d$$V⊂Zdin terms of a weighted sum of the entropies on blocks$$A\subset V$$A⊂Vwhen eachAis given an arbitrary nonnegative weight$$\alpha _A$$αA. These inequalities generalize the well known logarithmic Sobolev inequality for the Glauber dynamics. Moreover, they provide a natural extension of the classical Shearer inequality satisfied by the Shannon entropy. Finally, they imply a family of modified logarithmic Sobolev inequalities which give quantitative control on the convergence to equilibrium of arbitrary weighted block dynamics of heat bath type.