bluuebunny/crossref_metadata_2025 huggingface dataset:
Narrow band imaging versus white light for detecting sessile serrated lesion: A prospective randomized multicenter study
Authors: Staudenmann Dominic , Liu Ken , Varma Poornima , Wong May , Rai Sonam , Tsoutsman Tatiana , Choi Kyung Ho , Saxena Payal , Kaffes Arthur John
Published: September 2021

Objectives

Colonoscopy is the gold standard diagnostic test used to detect early colorectal lesions and prevent colorectal carcinoma. Narrow band imaging (NBI) is an imaging technique that provides improved image resolution of the mucosa during endoscopy. Whether NBI improves the detection of sessile serrated lesion (SSL) is controversial—our aim was to assess this during routine colonoscopy.

Methods

We conducted a multicenter, prospective, randomized, controlled trial. Patients underwent colonoscopy for screening, surveillance, or symptoms. They were randomized to either high‐definition white light (HD‐WL) or NBI in a 1:1 ratio. The primary outcome was SSL detection rate. Secondary outcomes were adenoma detection rate (ADR) and polyp detection rate (PDR).

Results

A total of 400 patients were randomized to NBI (N = 200) or HD‐WL (N = 200). The total colonoscopy time was slightly longer in the NBI group compared to HD‐WL (median time 14 vs. 12 min, p = 0.033). There were no statistically significant differences in SSL detection rate (7.5% NBI vs. 8.0% HD‐WL; p = 0.852), ADR (41.0% NBI vs. 37.5% HD‐WL; p = 0.531), or PDR (61.0% NBI vs. 54.0% HD‐WL; p = 0.157) between the two groups. No significant predictors of SSL detection were found on univariable or multivariable analysis. Increasing age and increased withdrawal time were an independent predictors of polyp detection and increasing age was also an independent predictor of adenoma detection on multivariable analysis.

Conclusion

In the hands of experienced colonoscopists, NBI does not improve SSL detection compared to HD‐WL. Withdrawal time and patient age remain important factors for polyp and adenoma detection.
Evolution of winter molting strategies in European and North American migratory passerines
Authors: Pageau Claudie , Sonnleitner Jared , Tonra Christopher M. , Shaikh Mateen , Reudink Matthew W.
Published: September 2021

Molt is critical for birds as it replaces damaged feathers and worn plumage, enhancing flight performance, thermoregulation, and communication. In passerines, molt generally occurs on the breeding grounds during the postbreeding period once a year. However, some species of migrant passerines that breed in the Nearctic and Western Palearctic regions have evolved different molting strategies that involve molting on the overwintering grounds. Some species forego molt on the breeding grounds and instead complete their prebasic molt on the overwintering grounds. Other species molt some or all feathers a second time (prealternate molt) during the overwintering period. Using phylogenetic analyses, we explored the potential drivers of the evolution of winter molts in Nearctic and Western Palearctic breeding passerines. Our results indicate an association between longer photoperiods and the presence of prebasic and prealternate molts on the overwintering grounds for both Nearctic and Western Palearctic species. We also found a relationship between prealternate molt and generalist and water habitats for Western Palearctic species. Finally, the complete prealternate molt in Western Palearctic passerines was linked to longer days on the overwintering grounds and longer migration distance. Longer days may favor the evolution of winter prebasic molt by increasing the time window when birds can absorb essential nutrients for molt. Alternatively, for birds undertaking a prealternate molt at the end of the overwintering period, longer days may increase exposure to feather‐degrading ultra‐violet radiation, necessitating the replacement of feathers. Our study underlines the importance of the overwintering grounds in the critical process of molt for many passerines that breed in the Nearctic and Western Palearctic regions.
Persistent yet vulnerable: resurvey of anAbiesecotone reveals few differences but vulnerability to climate change
Authors: Nelson Kellen N. , O’Dean Emily , Knapp Eric E. , Parker Albert J. , Bisbing Sarah M.
Published: September 2021

Climate change is shifting forest tree species distributions across elevational and latitudinal gradients, and these changes are often pronounced at ecotones where species meet their climatic bounds and are replaced by other species. Using an extensive ecotone composed of lower‐montane white fir (Abies concolorvar.lowiana) and upper‐montane red fir (Abies magnificavar.magnifica) in the central Sierra Nevada range of California, USA, we (1) examined how the demographics of the ecotone have responded to recent climate using a field observational study and a historical dataset, (2) quantified climate drivers across species life stages using contemporary demographic data, and (3) tested the potential impacts of future climate on species‐specific seedling survival and growth in a fully factorial growth chamber experiment that varied temperature, growing season length, and water availability. A re‐examination of the ecotone midpoint after 35 yr suggested a reduction inA. concolorsapling and tree densities and a rise inA. magnificaproportional dominance between surveys. Seedling abundances across the ecotone indicated thatA. magnificatends to dominate the regeneration layer and currently forms an important component of the seedling community at elevations below those whereA. magnificasaplings or trees begin to co‐dominate stands. Observational and experimental assessments suggest that temperature and precipitation serve as important drivers, differentiatingA. concolorvs.A. magnificadistributions, and are primary stressors at the seedling stage. Seedlings of both species were adversely affected by experimental climate treatments, althoughA. concolorexhibited greater survival and a more conservative growth strategy under extreme climatic stress thanA. magnifica. Projections indicate that historical climate conditions will rise by an amount greater than the ecotone’s current elevational extent by the end of the 21st century. Differential drivers of species abundances suggest that the projected climate will expand conditions that promoteA. concolorabundance and impedeA. magnificaabundance across the ecotone; however, disturbance activity and microclimatic conditions will also influence regeneration and overstory tree dynamics. Our study demonstrates the importance of quantifying species‐specific responses to climate and indicates that widespread regeneration failure may be one possible consequence in which species exhibit strong sensitivity to projected climate conditions.
Zeolitic‐Imidazolate Framework Derived Intermetallic Nickel Zinc Carbide Material as a Selective Catalyst for CO2 to CO Reduction at High Pressure
Authors: Maluf Nágila E. C. , Braga Adriano H. , Gothe Maitê L. , Borges Laís R. , Alves Gustavo A. S. , Gonçalves Renato V. , Szanyi János , Vidinha Pedro , Rossi Liane M.
Published: August 2021

The conversion of CO2 into CO is an important step in CO2 utilization to achieve clean fuels and value‐added chemicals. Herein, we explored the pyrolysis of zeolitic imidazolate framework‐8 (ZIF‐8) loaded with different amounts of Ni2+ to obtain Ni−Zn carbide (Ni3ZnC) embedded in N‐doped carbon. Ni is present in the intermetallic compound, while Zn excess remains on the N‐doped carbon. The Ni3ZnC phase catalyzes the selective hydrogenation of CO2 into CO via the reverse water gas shift reaction, reaching 100 % CO selectivity at ∼30 % CO2 conversion at 450 °C and atmosphere pressure (CO2 : H2=1 : 4, GHSV=30000 mL gcat−1 h−1). The methanation reaction of CO2/CO, which is usually favored over Ni catalysts, is suppressed. The selectivity to CO at the expense of CH4 is related to the stability of chemisorbed CO in the Ni3ZnC surface, which is lower compared to Ni surfaces. The Ni3ZnC@NC catalyst is selective towards CO over a wide range of conditions, including high pressure, that is usually required for the conversion of CO to hydrocarbons and alcohols via the Fisher‐Tropsch synthesis (FTS) process. Contrarily, a classical Ni/SiO2 catalyst prepared by impregnation produces CH4 under high pressure.
A randomized, double blind, parallel, placebo‐controlled study to investigate the efficacy of Lactobacillus paracasei N1115 in gut development of young children
Authors: Wang Shijie , Xun Yiping , Ahern Grace J. , Feng Lili , Zhang Dong , Xue Yuling , Ross Reynolds Paul , Doolan Andrea M. , Stanton Catherine , Zhu Hong
Published: September 2021

In this clinical trial, the safety and effectiveness of Lactobacillus paracasei N1115 (LP N1115) were investigated as a potential probiotic to enhance gut development in young children born by caesarean section. Infants and young children between the ages of 6 months and 3 years were administered with a probiotic consisting of LP N1115 strain (n = 30) or placebo supplement (n = 30) over an 8 weeks intervention. And the stool consistency, bowel habits, salivary cortisol, fecal microbiota, and short‐chain fatty acid metabolism were investigated. Efficacy data were obtained from 58 participants who completed the study. Overall, the placebo functioned similarly to LP N1115 group in relation to stool consistency, gastrointestinal symptoms, salivary cortisol, and short‐chain fatty acids. However, the scoring data relating to the 6–18 months subgroup receiving LP N1115 remained stable over 8 weeks in comparison to placebo. Analysis of the fecal microbiota using 16S rRNA amplicon sequencing revealed that the phyla Firmicutes represented 62% of the microbial relative abundance in the feces of the subjects during the intervening period. No significant changes in alpha‐ or beta‐diversity were noted between the placebo and LP N1115 groups overtime and at each time point. Differential abundance analysis indicated an increase in Lactobacillus in LP N1115 group at weeks 4 (p < .05) and 8 (p < .05) in comparison to the placebo group. These results suggest that probiotic supplementation with LP N1115 was well tolerated by the young children and subtle changes in the microbiome were noted throughout the intervention period.
Highly Stereoselective Aldol Reactions by Memory of Chirality: Synthesis of Quaternary β‐Hydroxy α‐Amino Acids
Authors: Roupnel Loïc , Guillot Régis , Gori Didier , Viswambharan Baby , Kouklovsky Cyrille , Alezra Valérie
Published: September 2021

We describe here an asymmetric aldol reaction based on the principle of Memory of Chirality. From α‐amino acids such as leucine and methionine, we have synthesized in two steps quaternary α‐amino acid derivatives with high diastereoselectivity and enantioselectivity, using the chirality of the initial α‐amino acid as the only chirality source. Furthermore, we were able to determine the relative and absolute configurations of the aldol products thanks to crystallographic structures and thus showed that the relative configuration depended on the aldehyde employed. We proposed a stereoselectivity explanation and obtained also quaternary β‐hydroxy α‐amino acids after acidic hydrolysis.
β‐Caryophyllene may attenuate hyperoxaluria‐induced kidney dysfunction in rats by regulating stress marker KIM‐1/MCP‐1 and NF‐κB signaling pathway
Authors: Xu Xia , Yan Jiamiao
Published: September 2021

β‐Caryophyllene (BCP), a bicyclic sesquiterpene, has proved to exhibit antioxidant and anti‐inflammatory activities. The present study is carried out to investigate BCP impact on hyperoxaluria‐induced kidney dysfunction in male Wistar rats. The animals were categorized into four groups, namely, Group I, control rats; Group II, ethylene glycol (inducer); Group III, inducer + BCP (100 µM/kg bw); Group IV, BCP alone. After the treatment period, the rate of creatinine clearance and the concentration of urea in urine and serum were assessed. Histopathology reports were conducted to study renal and liver tissues, while the reverse transcription‐polymerase chain reaction studies were carried out for messenger RNA expression of inflammatory (nuclear factor kappa B) and endoplasmic reticulum (ER) stress (kidney dysfunction molecule‐1, monocyte chemoattractant protein‐1, glucose binding protein 78, CHOP, activating factor 4, and X‐box binding protein‐1) markers as well as antioxidant activity for the hyperoxaluric rats. Western blot was performed to investigate the level of protein expression by the treatment group on apoptotic (Bcl‐2, Bax, caspase‐3, and caspase‐9) proteins. The results show BCP to possess a renoprotective effect under hyperoxaluric conditions by decreasing the level of the inflammatory and ER stress markers and restoring the enzymes' antioxidant activities. The histology reports depicted the satisfactory morphology of glomerulus in diseased rats. Furthermore, the results of Western blot suggested that BCP may possess inhibitory action on apoptosis by affecting the mitochondrial‐dependent apoptotic pathway. Therefore, BCP can be considered as a potential candidate for the therapy of hyperoxaluric‐induced kidney complications.
Small extracellular vesicles released by infused mesenchymal stromal cells target M2 macrophages and promote TGF‐β upregulation, microvascular stabilization and functional recovery in a rodent model of severe spinal cord injury
Authors: Nakazaki Masahito , Morita Tomonori , Lankford Karen L. , Askenase Philip W , Kocsis Jeffery D.
Published: September 2021

Intravenous (IV) infusion of bone marrow‐derived mesenchymal stem/stromal cells (MSCs) stabilizes the blood‐spinal cord barrier (BSCB) and improves functional recovery in experimental models of spinal cord injury (SCI). Although IV delivered MSCs do not traffic to the injury site, IV delivered small extracellular vesicles (sEVs) derived from MSCs (MSC‐sEVs) do and are taken up by a subset of M2 macrophages. To test whether sEVs released by MSCs are responsible for the therapeutic effects of MSCs, we tracked sEVs produced by IV delivered DiR‐labelled MSCs (DiR‐MSCs) after transplantation into SCI rats. We found that sEVs were released by MSCs in vivo, trafficked to the injury site, associated specifically with M2 macrophages and co‐localized with exosome markers. Furthermore, while a single MSC injection was sufficient to improve locomotor recovery, fractionated dosing of MSC‐sEVs over 3 days (F‐sEVs) was required to achieve similar therapeutic effects. Infusion of F‐sEVs mimicked the effects of single dose MSC infusion on multiple parameters including: increased expression of M2 macrophage markers, upregulation of transforming growth factor‐beta (TGF‐β), TGF‐β receptors and tight junction proteins, and reduction in BSCB permeability. These data suggest that release of sEVs by MSCs over time induces a cascade of cellular responses leading to improved functional recovery.
Effects of vine top shading on the accumulation of C6/C9 compounds in 'Cabernet Sauvignon’ (Vitis vinifera L.) grape berries in northwestern China
Authors: Zhang Zhenzhen , Qiao Dan , He Lei , Pan Qiuhong , Wang Shuwei
Published: September 2021

BACKGROUND

The Xinjiang Uygur Autonomous Region is an arid and semi‐arid region with low rainfall and strong sunlight; thus, grape berries in this region accumulate sugar content rapidly, and the ripening process is shorter than that in other regions. Although previous studies illustrated that altered sunlight conditions could influence the aroma profiles of grape berries, less attention has been paid to the effect of vine top shading on volatile compounds under a dry–hot climate.

RESULT

We focused on the effects of vine top shading on the concentrations of linolenic and linoleic acids, as well as their metabolites, the C6/C9 compounds, in grape berries. Four vine top shading treatments at veraison (ripening onset) and post‐veraison (skin full coloration) were performed by reducing solar exposure to the grapevines by 20% and 50% respectively. Apart from (E)‐2‐hexenal in the 20% shading treatment of 2016, (E)‐2‐hexenal were not promoted by the 50% shading and 20% shading treatments during veraison to harvest in both of the vintages. By contrast, the influence of vine top shading from post‐veraison till harvest was different between the two vintages; these C6 compounds were decreased in both of the shading treatments in 2016, whereas most of them were promoted in 2017, possibly related to daily sunshine hours in this period. In addition, the C9 compound nonanal with very low concentration exhibits a significant difference among various treatments by two‐factor analysis of variance. As for linolenic acid and linoleic acid, two types of C6 compound biosynthetic precursors, four shading treatments all reduced their concentration, except for linolenic acid in the 50% shading treatment of 2016. Moreover, it appeared to have no apparent correlation between the variations of two precursors and their volatile metabolites, indicating that there is a complex impact of vine shading on C6 compound biosynthesis.

CONCLUSION

Vine top shading at veraison can reduce the accumulation of some C6 compounds in grape berries, but no consistent consequence was attained for the vine shading at pre‐veraison. The findings indicate the significance of grapevine solar exposure management at veraison in controlling the level of C6 compounds in a dry–hot region like Xinjiang. © 2021 Society of Chemical Industry.
Planck Spectroscopy
Authors: Xiao Yuzhe , Wan Chenghao , Salman Jad , Maywar Ian J. , King Jonathan , Shahsafi Alireza , Kats Mikhail A.
Published: August 2021

All spectrometers rely on some mechanism to achieve spectral selectivity; common examples include gratings, prisms, and interferometers with moving mirrors. A spectroscopic technique—here dubbed Planck spectroscopy—that measures the spectral emissivity of a surface using only a temperature‐controlled stage and a detector, without any wavelength‐selective optical components is experimentally demonstrated and validated. Planck spectroscopy involves the measurement of temperature‐dependent thermally emitted power, where the spectral selectivity is realized via the temperature and wavelength dependence of Planck's law. Planck spectroscopy in the mid infrared, for wavelengths from 3 to 13 µm—limited primarily by the bandwidth of the detector—with resolution of ≈1 µm is experimentally demonstrated and validated. The minimalistic setup of Planck spectroscopy can be implemented using infrared cameras to achieve low‐cost infrared hyperspectral imaging and imaging ellipsometry.
Poly(lactic acid)‐Based Film with Excellent Thermal Stability for High Energy Density Capacitor Applications
Authors: Wang Yonggui , Zhang Jinxi , Zhang Bowen , Ren Kailiang
Published: September 2021

Dielectric capacitors play a key role in high power electronics, electric vehicles, and medical devices. Due to the biodegradability, high thermal stability, and ease of processing, poly(lactic acid)‐based (PLA) films are widely used in applications of tissue engineering, actuators, and sensors. In this investigation, PLA films are prepared using a solution casting method for high energy density capacitor applications. It is found that the stretched poly(d‐lactic acid) (PDLA) film exhibits an energy density and charge discharge efficiency of 18.5 J cm−3 and 95%, respectively, at room temperature. Furthermore, after a heating time of 30 min at 100 °C, it is found that the energy density and chargedischarge efficiency of the stretched PDLA films are maintained at 11.2 J cm−3 and 76%, respectively. In comparison, the energy density and efficiency of the stretched PDLA film are 1.03‐fold and 53% higher, respectively, than those of the stretched poly(vinylidene fluoride‐hexafluoropropylene) film at 100 °C with the same heat treatment. Compared with a high temperature polyimide material, the energy density of the stretched PDLA film is 1.98‐fold higher at 100 °C. The PLA‐based material shows great promise for application in high energy density capacitors operating at a high temperature (100 °C).
Double Network Glycerol Gel: A Robust, Highly Sensitive, and Adaptive Temperature Sensor
Authors: Feng Zhanbin , Zhang Ziteng , Chu Bo , Zhang Xing‐Hong
Published: September 2021

Temperature sensors have great potential applications for the body temperature monitoring, it's a big challenge to prepare sensors with high sensitivity and maintaining adaptive properties for the long‐term applications. In this study, an organohydrogel for the temperature sensor is achieved via glycerol solvent replacement of water in the poly‐N‐acryloyl glycinamide (PNAGA)/carrageenans double network (DN) hydrogel. Owing to successful construction of strong multiple hydrogen bonding (H‐bonding) interactions among PNAGA chains and carrageenans, the PNAGA‐based glycerol gel (Gly‐gel) sensor exhibits excellent thermal stabilities, possesses high sensitivities (2% °C) resulted from the acceleration of mobility of ions at high temperature and shows high tensile strength of about 4 MPa without chemical crosslinkers (higher than most reported organohydrogel‐based temperature sensor) with self‐healable performance. In addition, the double network of Gly‐gel enables it excellent dual and triple shape memory performance with high fixing ratio (Rf, 88%), recovery ratio (Rr, 95%) under large deformations (above 80%) that are beneficial to the potential application in wearable devices. Different from previous temperature sensors, this work provides a facile approach to prepare overly sensitive temperature sensors with the combination of excellent thermal stability, high tensile strength and adaptive properties via the solvent replacement of hydrogel.
COVID‐19 impediments and business start‐ups in Pakistan: Evidence from the second wave of the pandemic
Authors: Soomro Bahadur Ali , Lakhan Ghulam Rasool , Shah Naimatullah
Published: September 2021

The present paper examines COVID‐19 impediments and business start‐ups in Pakistan when the country entered the second wave of the COVID‐19 pandemic. This study selected entrepreneurs in Pakistan to explore the effects of the second wave. The study findings highlight the significant negative impacts of fear of COVID‐19 (FC), COVID‐19 stress and anxiety (SA), and perceptions of the arrival of COVID‐19's second wave (ASW) on business start‐ups (BS). The findings may support policy makers in diminishing the fear, anxiety, and negative perceptions of the arrival of COVID‐19 waves.
On fundamental solutions of higher‐order space‐fractional Dirac equations
Authors: Faustino Nelson
Published: September 2021

Starting from the pseudo‐differential decomposition of the Dirac operator in terms of the fractional operator of order 1 and of the Riesz–Hilbert type operator we will investigate the fundamental solutions of the space‐fractional Dirac equation of Lévy–Feller typeinvolving the fractional Laplacian of orderα, with 2m≤α < 2m + 2 ( ), and the exponentiation operator as the hypercomplex counterpart of the fractional Riesz–Hilbert transform carrying theskewness parameter θ, with values in the range . Such model problem permits us to obtain hypercomplex counterparts for the fundamental solutions of higher‐order heat‐type equations in case where the even powers resp. odd powers ( ) resp. ( ) of are being considered.
Parteien zur Wahl
Authors: Bulmahn Maren
Published: September 2021

Mehr Geld für die Wissenschaft wünscht sich die deutsche Forschungsgemeinschaft, steuerliche Förderung und weniger Bürokratie möchte die chemische Industrie. Die GDCh hat nachgefragt, was die Parteien vorhaben.
Schaum in Aktion
Authors: Schad Tamara , Stubenrauch Cosima , Preisig Natalie , Drenckhan Wiebke , Blunk Dirk , Piening Heinrich
Published: September 2021

Historische Kulturgüter wie alte Kutschen lassen sich nun ohne Putzhilfen wie Wattestäbchen reinigen. Feinste Bläschen saugen Schmutz auf und wischen über Oberflächen.
(M)Ein ganz persönlicher Beitrag
Authors: Leusmann Eliza
Published: September 2021

Wer nachhaltig lebt, lebt unbequem – so die gängige Vorstellung. Aber wer Bestehendes und Gegebenheiten hinterfragt, kann ohne übermäßige Anstrengung zu weniger Verschwendung beitragen. Einige Ideen abseits von kälter waschen, seltener duschen und weniger Fertiggerichte kaufen.
"Planetare Leitplanken" ‐‐ Maximilian Hempel im Interview
Authors: Zbikowski Frauke
Published: September 2021

Kreislaufwirtschaft ist einer der zentralen Förderschwerpunkte der Deutsche Bundesstiftung Umwelt. Maximilian Hempel, Abteilungsleiter für Umweltforschung und Naturschutz, erläutert, wie es dazu kam.
Karriere: Nachhaltigkeit in der Industrie "mit langem Atem"
Authors: Zbikowski Frauke
Published: September 2021

Die chemische Industrie kommt nicht daran vorbei, nachhaltiger zu werden. Dies meinen junge Chemieingenieurinnen und Chemiker, die an ihren Arbeitsplätzen dazu beitragen, dass die Unternehmen ihre Rohstoffbasis umstellen, weniger Lösungsmittel verwenden oder die Umweltauswirkungen der Produktion minimieren. Das Chemiestudium bereitet auf solche Aufgaben nicht immer vor.
Nachruf: Wittko Francke (1940‐2020)
Authors: Schulz Stefan , Meier Chris
Published: September 2021

Am 27. Dezember 2020 starb Wittko Francke, Professor für Organische Chemie. Sein zentrales Forschungsgebiet war die chemische Ökologie.
Adaptive event‐triggered control of pure‐feedback systems with quantized input and unknown input delay
Authors: Xia Xiaonan , Zhang Tianping , Kang Guanpeng , Fang Yu
Published: September 2021

This article presents an adaptive event‐triggered dynamic surface control for pure‐feedback systems with unknown input time‐delay and quantized input. Event‐triggered and quantized input are both of discontinuity, which will make their integral item nondifferentiable and the integral mean value theorem cannot be applied. In order to solve the design problem of input delay system with discontinuous input, an auxiliary tracking error, an auxiliary system and Lyapunov–Krasovskii functionals are well designed, which can effectively deal with the input delay and allows the time delay to be unknown. Moreover, the improved event‐triggered quantized control can greatly reduce the amount of calculation of traditional quantized control and avoid unnecessary network access. The stability analysis shows that all signals in the closed‐loop system are semi‐globally uniformly ultimately bounded, and the output constraint is not violated. A simulation example of practical control system is conducted to demonstrate the effectiveness of proposed control protocol.
Robust saddle‐point criterion in second‐order partial differential equation and partial differential inequation constrained control problems
Authors: Treanţă Savin
Published: September 2021

In this article, for a given class of multi‐dimensional scalar variational control problems (named ) with mixed constraints implying second‐order partial differential equations and inequations, we introduce an auxiliary (modified) class of variational control problems (named ), which is much easier to study, and provide some characterization results of and by using the notions of normal weak robust optimal solution and robust saddle‐point associated with a Lagrange functional corresponding to . For this aim, we consider scalar multiple integral cost functionals and the notion of convexity associated with a multiple integral functional driven by an uncertain multi‐time controlled second‐order Lagrangian.
Pharmacokinetics, Mechanism, and Docking Study of Antioxidant Aryl‐Bisthiourea Derivatives for Alzheimer's Disease
Authors: Bahadur Ali , Iqbal Shahid , Shoaib Muhammad , Zulqarnain Muhammad , Shah Mazloom , Abd‐Rabboh Hisham S. M. , Perwez Usama , Qayyum Muhammad Abdul , Zaman Ajmal
Published: September 2021

Novel aryl‐bisthiourea derivatives (3 a–3 j) were synthesized by a two‐step route for the study of free‐radical scavenging property and acetylcholinesterase enzyme (AChE) inhibition study. The effect of the electronic environment on the aryl structure of ArBTU on the AChE inhibition was studied. Lineweaver‐Burk plot was used for kinetic study of inhibition of AChE by using ArBTU derivatives which exhibited very good bioactivity of inhibition against acetylcholinesterase enzyme. Central Nervous System (CNS) permeability and the Blood‐Brain Barrier values of all ArBTU derivatives (3 a–3 j) were also similar to the reference value (>−2 logPS< −3 and >−0.3 log BB< −1), respectively. The molecular docking study of derivative 3 g presented a very good interactions with tested protein. The mechanism of AChE inhibition was found from the kinetic studies of novel ArBTU derivatives. A pharmacokinetic study of AChE inhibition was also evaluated. ArBTU derivatives (3 a–3 j) exhibited the best lead‐like potential. Molecular docking study described the binding ability of the highly effective derivative 3 g with the acetylcholinesterase enzyme.
Comparative MD Study of Inhibitory Activity of Opaganib and Adamantane‐Isothiourea Derivatives toward COVID‐19 Main Protease Mpro
Authors: Jovanović Jelena Đorović , Antonijević Marko , El‐Emam Ali A. , Marković Zoran
Published: September 2021

In this study, the inhibitory potency of four adamantly‐ isothiourea derivatives (compounds 1 [4‐bromobenzyl (Z)‐N′‐(adamantan‐1‐yl)‐4‐phenylpiperazine‐1‐carbothioimidate], 2 [3,5‐bis(trifluoromethyl)benzyl (Z)‐N′‐(adamantan‐1‐yl)‐4‐phenylpiperazine‐1‐carbothioimidate], 3 [4‐bromobenzyl (Z)‐N‐(adamantan‐1‐yl)morpholine‐4‐carbothioimidate] and 4 [3,5‐bis(trifluoromethyl)benzyl (Z)‐N‐(adamantan‐1‐yl)morpholine‐4‐carbothioimidate]) was evaluated against SARS‐CoV‐2 targeted proteins. The investigated compounds 1–4 possess a similar structure to opaganib, which is used in studies like a potential drug for COVID‐19 treatment. Since examined adamantly‐isothiourea derivatives (1–4) shown broad‐spectrum of antibacterial activity and significant in vitro cytotoxic effects against five human tumor cell lines and shown similarity in structure with opaganib, it was of interest to study their inhibitory potency toward some SARS‐CoV‐2 proteins such as SARS‐CoV‐2 main protease Mpro and mutation of SARS‐CoV‐2 Spike (S) Protein D614G. The inhibitory potency of studied compounds is examined using molecular docking and molecular dynamic simulations. The results of molecular docking simulations indicate compound 1 as the most prominent candidate of inhibition of SARS‐CoV‐2 main protease Mpro (▵Gbind=11.24 kcal/mol), while almost the same inhibition potency of all studied compounds is exhibited toward D614G. Regarding the results obtained by molecular dynamic simulations, compounds 1 and 4 possess similar inhibitory potency toward SARS‐CoV‐2 main protease Mpro as opaganib (▵Gbind
40 kcal/mol).
Theoretical Investigation of the Chiral Transition of α‐Alanine Cu2+ Complex in Water Solution
Authors: Yang Xiaocui , Jiang Chunxu , Zhang Xuejiao , Liu Fang , Tong Hua , Hu Yuming , Ma Hongyuan , Gao Feng , Wang Zuocheng
Published: September 2021

The chiral transition of S‐α‐alanine Cu2+ complex (S−A) in water solution was investigated by density functional theory combined with SMD solvation model. In principle, the chiral transition of S−A could be realized via the following four pathways: carbonyl oxygen as the bridge, carbonyl oxygen and amino nitrogen as the bridge, amino nitrogen as the bridge and Cu as the bridge. The potential energy surface calculation shows that under the effect of implicit solvent, the reaction channel with Cu as the bridge is the most dominant, and the energy barrier of the rate‐determining steps is 103.3 kJ mol−1. The subdominant channel of hydrogen migration is the bridge channel of amino nitrogen, and the energy barrier of the rate‐determining steps is 183.5 kJ mol−1. The remaining two channels are inferior channels. Under the explicit solvent effect, the channel with amino‐nitrogen as the bridge is the most advantageous, and the energy barrier of the rate‐determining steps is reduced to 138.0 kJ mol−1. The subdominant channel for hydrogen migration is Cu, and the energy barrier of the rate‐determining steps increases to 145.3 kJ mol−1. The remaining two channels are inferior channels. The results show that S−A complex can better maintain its chiral characteristics in water solution, and the divalent copper salt of α‐alanine is safe to supplement Cu2+ and alanine in living bodies.
Green and Facile Synthesis of Luminescent CQDs from Pomegranate Peels and its Utilization in the Degradation of Azure B and Amido Black 10B by Decorating it on CuO Nanorods
Authors: Vyas Yogeshwari , Chundawat Priyanka , Dharmendra  , Punjabi Pinki B. , Ameta Chetna
Published: September 2021

Green fluorescent water‐soluble carbon quantum dots (CQDs) of size 6 nm were fabricated by carbonization of pomegranate (Punica granatum) peels at a mild temperature of 160 °C for 12 h. The CuO NRs were prepared by the precipitation method. The formation of CQDs and CuO nanorods (NRs) was confirmed. The chemical composition and morphological features of CQD, CuO, and composite (CuO/CQDs) are characterized by XRD, FESEM, HRTEM, FTIR, EDX, XPS, and BET. XRD and TEM analysis shows the amorphous nature of CQDs and the monoclinic nature of CuO NRs. The CuO NRs decorated with CQDs have given the maximum photocatalytic activity for the degradation of Azure B (97 %) and Amido black 10 B (94 %) than CuO NRs alone. Several water quality parameters have been measured before and after degradation. Hence bio‐based luminescent CQDs with a high yield were synthesized for the first time through a greener route.
Size‐Dependent Cobalt Catalyst for Lithium Sulfur Batteries: From Single Atoms to Nanoclusters and Nanoparticles
Authors: Zhou Xing , Meng Ruijin , Zhong Ning , Yin Shuangfeng , Ma Guoqiang , Liang Xiao
Published: September 2021

The sulfur redox conversion with catalytically improved kinetics is promising to mitigate the polysulfides shuttling. While the size of electrocatalyst always brings different catalytic behaviors for various heterogeneous catalytic reactions, it is yet to be explored for Li‐S batteries. Herein, a systematical study of size‐dependent catalytic activity toward polysulfides conversion and the relevance to electrochemical performance are reported, by constructing Co catalysts with different atomic scales from single atoms, atomic clusters to nanoparticles. Fundamental electrocatalytic studies are focused by probing the reduction kinetics and activation energies of sulfur chemistry. The single atomic Co shows the best charge transfer/kinetic toward sulfur redox, especially for the rate‐determining reaction (Li2S4 ↔ Li2S) as demonstrated by the significantly lowered energy barrier for Li2S nucleation/dissolution. This is owing to stronger geometric deformation of the catalyst with lower aggregation extent when it interacts with sulfur species, thus leading to decreased Gibbs free energy changes as elucidated by DFT calculations. The superior catalytic activity of single atomic Co promises a high specific capacity (4.98 mAh cm−2) at an areal loading of 4.3 mg cm−2 over long‐term cycling. The finding emphasizes the significance of the size‐dependent catalytic activity to the reaction kinetics and the overall performance of Li‐S batteries.
Perovskite/Si tandem solar cells: Fundamentals, advances, challenges, and novel applications
Authors: Cheng Yuanhang , Ding Liming
Published: September 2021

The world record device efficiency of single‐junction solar cells based on organic–inorganic hybrid perovskites has reached 25.5%. Further improvement in device power conversion efficiency (PCE) can be achieved by either optimizing perovskite films or designing novel device structures such as perovskite/Si tandem solar cells. With the marriage of perovskite and Si solar cells, a tandem device configuration is able to achieve a PCE exceeding the Shockley–Queisser limit of single‐junction solar cells by enhancing the usage of solar spectrum. After several years of development, the highest PCE of the perovskite/Si tandem cell has reached 29.5%, which is higher than that of perovskite‐ and Si‐based single‐junction cells. Here, in this review, we will (1) first discuss the device structure and fundamental working principle of both two‐terminal (2T) and four‐terminal (4T) perovskite/Si tandem solar cells; (2) second, provide a brief overview of the advances of perovskite/Si tandem solar cells regarding the development of interconnection layer, perovskite active layer, tandem device structure, and light management strategies; (3) third, discuss the challenges and opportunities for further developing perovskite/Si tandem solar cells. This review article, on the one hand, provides a comprehensive understanding to readers on the development of perovskite/Si tandems. On the other hand, it proposes various novel applications that may bring such tandems into the market in a near future.
“A Question of Integrity”: Academic Values Torn Between Organizational Affiliation, National Competitiveness and the Global Academic Community
Authors: Hölscher Michael
Published: September 2021

Values of higher education, as supported by the IAU, are grounded in the belief-systems and behaviour of the individual researchers/teachers and the academic community more generally. Although these values are influenced from the outside by educational policies and economic considerations, and although they also encompass societal views on science (e.g. trust in science), it is academia itself that has to uphold, and sometimes defend, the inner principles of higher education.
Higher Education and the Enduring Value of Hospitality: Reflections for the 21st Century
Authors: Blanco Gerardo L.
Published: September 2021

The 21st century is a perilous time for international collaboration among university actors. Mobility and international exchange have come to a total standstill as the world shelters in place, trying to slow down the course of a pandemic. However, the crisis of hospitality in higher education has been long in the making. Within universities, internationalization has been driven by profits and revenues for decades, while discussions of core values have been cast aside as utopian or idealistic. There are thousands of displaced, imprisoned and exiled academics, and there are millions of university-aged refugees in the world, with only a tiny fraction of them entering universities. Beyond university walls, scepticism toward the other has been brewing, popularizing xenophobic nationalism and construing mobility as a threat that must be curtailed or regulated to new extremes. As some governments have turned to authoritarianism, universities have become targets, and government actions have resulted in significant numbers of displaced and unemployed academics, many of whom look beyond national borders to find spaces where the pursuit of their ideas is less threatening and where they can exercise their intellectual calling. Responding to these needs requires hospitality, which is not unprecedented, but that has become a lower priority among many others such as the constant pressure to move up the rankings or league tables.
From Emergency Remote Teaching to Strategically Embracing Online Learning
Authors: Tzavara Dionisia
Published: September 2021

As a response to the Covid-19 pandemic, universities across the globe closed campuses, cancelled face-to-face classes, and resorted to digital instruction in an attempt to continue offering instruction, providing continuity to their students, and keeping the academic year going. This movement away from face-to-face instruction happened on a large scale (according to a World Economic Forum article “Some 1.5 billion students—close to 90% of all primary, secondary and tertiary learners in the world—are no longer able to physically go to school” (Kandri 2020), across various institutions and departments, and large numbers of students and academics were impacted by this shift to online instruction.
Is the Pandemic Leading to a Paradigm Shift in Higher Education?
Authors: Lamagna Carmen Z. , Khan Manzur H.
Published: September 2021

Indoor gatherings of many people are high-risk sites for the spread of COVID-19; this includes schools, colleges and university campuses. This evolving situation will not only be vastly disruptive but will also lead to a paradigm shift in higher education institutions (HEI).
A Personal Reflection on the Key Challenge for Higher Education: Improving the Quality of University Instruction
Authors: Dill David
Published: September 2021

Since the founding of the University of Bologna in 1088, the quality and societal impact of university-based research has steadily risen and is widely expected to continually improve in the future. But, while the effectiveness of university teaching over this same period has improved through the adoption of laboratory instruction, the seminar method, tutorials, and more valid and reliable means of assessing students, the qualitative enhancement and continuous development of instruction compared to research appears less certain. Why does this difference exist? I will argue the cause is to be found in the limitations of universities’ traditional collegial culture and in the failure of recent national efforts to improve academic quality to effectively address academic norms and values.
Universities as Lifelong Learning Institutions: A New Frontier for Higher Education?
Authors: Atchoarena David
Published: September 2021

For half a century now, lifelong learning has provided—with more or less intensity - the philosophical and conceptual background in which education policies have been framed (Kejawa, 2017). When Paul Lengrand defined l’éducation permanente (1970), learning was conceived as part of a humanistic vision of the world, intrinsically characterized by fundamental values like human dignity, equal rights and social justice and respect for cultural diversity, as well as a sense of shared responsibility and a commitment to international solidarity. Today, these principles remain fundamental aspects of our common humanity and the enduring ideals of what learning can achieve.
IAU: The Power to Foster Higher Education for Sustainable Development
Authors: Mongkhonvanit Pornchai , Rukspollmuang Chanita , Sawheny Yhing
Published: September 2021

Modernization theory, which believes that “development equates economic growth” and changes in social, political, and cultural structures are the pathways for societies to become modernized, has been the predominant paradigm for the development of nations for decades. However, the model was met with a lot of criticism, and there was a movement to rethink the real meaning of development and well-being. Alternatives for development were proposed, but the most widely accepted paradigm is “sustainability” or “sustainable development” which was defined by the World Commission on Environment and Development (WCED) in the 1987 Brundtland Report (also called “Our Common Future”) as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs.” Under this development paradigm, programs, initiatives, and actions aim not only at the preservation of a particular resource but also at other distinct areas: economic, environmental, and social - known as the three pillars of sustainability. The Brundtland Report has had a worldwide impact. “Agenda 21”, a comprehensive plan of action to build a global partnership for sustainable development to improve human lives and protect the environment, was adopted in the 1992 Earth Summit in Rio de Janeiro, followed by many other agendas, including the United Nations Millennium Development Goals (MDG) (2000–2015) and the present United Nations 2030 Agenda for Sustainable Development or the 17 SDGs.
Aligning Higher Education’s Promise of Well-Being with Sustainability as a Purpose of Education
Authors: Kohl Katrin , Hopkins Charles
Published: September 2021

In a world of increasing complexity, there is a growing demand for access to higher education. People of all ages aim at academic degrees to qualify for decent career opportunities in the future, often in hope of a better life. Numbers in higher education are globally on the rise with today approximately 38% gross enrolment in tertiary education (UNESCO 2018).
Knowledge and Partnerships for Sustainability and Equality
Authors: Habib Adam
Published: September 2021

We live in interesting, but dangerous times; our world today is as unequal as it was before World War I and II. We are increasingly becoming as socially and politically polarized as we were then. Right-wing populist and nativist parties stalk all of our lands, deepening divides among our communities both nationally and internationally. Political and economic elites are paralyzed about what to do, or at least have not been able to marshal the will to undertake what needs to be done.
Post-COVID-19: A Time of Opportunity for Asian Universities
Authors: Woon Eden Y.
Published: September 2021

By the end of 2019, IAU member universities were already grappling with a variety of issues and knew that 2020 was going to be a challenging year. But many of them were still optimistic and looked forward to IAU’s 70th Anniversary Year when universities would continue to push forward the frontiers of knowledge and play an increasing role of providing young people an understanding of the world beyond their hometown. And the key of this optimism was based on increased internationalization.
Creating Democratic Civic Universities in a Post-COVID-19 World: The IAU and Global Collaboration
Authors: Harkavy Ira
Published: September 2021

This essay is organized around four questions, the answers to which should, in my judgment, be helpful in thinking about universities now and in a post-pandemic world. My goal is to contribute to discussions and actions that result in the creation of democratic civic universities.
Planar solutions of higher-spin theory. Part I. Free field level
Authors: Didenko V. E. , Korybut A. V.
Published: August 2021

Abstract

Many black hole solutions of General Relativity are known to be linearly exact. This opens a way to study them in gauge theories that apart from gravity contain fields of higher spin s > 2. Starting with a black brane in AdS4 we find its free field higher- spin generalization that respects static and planar symmetry for all bosonic gauge fields s ≥ 0. The solution is found for both the higher-spin curvatures and potentials in the form suitable for further non-linear analysis and satisfies the multi copy relation.
Production of bioactive plant secondary metabolites through in vitro technologies—status and outlook
Authors: Wawrosch Christoph , Zotchev Sergey B.
Published: September 2021

Medicinal plants have been used by mankind since ancient times, and many bioactive plant secondary metabolites are applied nowadays both directly as drugs, and as raw materials for semi-synthetic modifications. However, the structural complexity often thwarts cost-efficient chemical synthesis, and the usually low content in the native plant necessitates the processing of large amounts of field-cultivated raw material. The biotechnological manufacturing of such compounds offers a number of advantages like predictable, stable, and year-round sustainable production, scalability, and easier extraction and purification. Plant cell and tissue culture represents one possible alternative to the extraction of phytochemicals from plant material. Although a broad commercialization of such processes has not yet occurred, ongoing research indicates that plant in vitro systems such as cell suspension cultures, organ cultures, and transgenic hairy roots hold a promising potential as sources for bioactive compounds. Progress in the areas of biosynthetic pathway elucidation and genetic manipulation has expanded the possibilities to utilize plant metabolic engineering and heterologous production in microorganisms. This review aims to summarize recent advances in the in vitro production of high-value plant secondary metabolites of medicinal importance.

Key points

• Bioactive plant secondary metabolites are important for current and future use in medicine

• In vitro production is a sustainable alternative to extraction from plants or costly chemical synthesis

• Current research addresses plant cell and tissue culture, metabolic engineering, and heterologous production

Graphical abstract