bluuebunny/crossref_metadata_2025 huggingface dataset:
Annotated functional decomposition
Authors: Tubić Stefan , Cvetanović Miloš , Radivojević Zaharije , Stojanović Saša
Published: March 2021

Experiences gained from the domain‐specific courses showed that students focus mostly on how to implement solutions and less on what must be considered within the solution. In the case of information systems‐related courses, students focus on system development using specific languages and frameworks while often disregard the required logical checks and constraints. This paper introduces annotated functional decomposition (AFD) to assist students in overcoming the challenge of understanding the logic of an information system. AFD leverages methodological concepts from computational thinking and represents a problem decomposition approach that is extended with additional levels of decomposition. These levels of decomposition are orthogonal and implemented with annotations that enrich a decomposition with information regarding control and data flow, as well as reuse and implementation details. AFD could be exercised with a supporting AFD Tool developed as an Eclipse IDE plugin that performs syntax and semantic checks along with the generation of UML sequential diagrams. The AFD Tool and its source code are available free of charge. Quantitative and qualitative evaluations of AFD Tool usage during an information systems course revealed that students who used AFD achieved higher average grades than those who used UML for solving the same problems, and moreover that students perceived AFD as easy to understand and use.
Investigation of Vitamin D2 and Vitamin D3 Hydroxylation by Kutzneria albida
Authors: Schmitz Lisa Marie , Kinner Alina , Althoff Kirsten , Rosenthal Katrin , Lütz Stephan
Published: March 2021

The active vitamin D metabolites 25‐OH−D and 1α,25‐(OH)2−D play an essential role in controlling several cellular processes in the human body and are potentially effective in the treatment of several diseases, such as autoimmune diseases, cardiovascular diseases and cancer. The microbial synthesis of vitamin D2 (VD2) and vitamin D3 (VD3) metabolites has emerged as a suitable alternative to established complex chemical syntheses. In this study, a novel strain, Kutzneria albida, with the ability to form 25‐OH−D2 and 25‐OH−D3 was identified. To further improve the conversion of the poorly soluble substrates, several solubilizers were tested. 100‐fold higher product concentrations of 25‐OH−D3 and tenfold higher concentrations of 25‐OH−D2 after addition of 5 % (w/v) 2‐hydroxypropyl β‐cyclodextrin (2‐HPβCD) were reached. Besides the single‐hydroxylation products, the human double‐hydroxylation products 1,25‐(OH)2−D2 and 1,25‐(OH)2−D3 and various other potential single‐ and double‐hydroxylation products were detected. Thus, K. albida represents a promising strain for the biotechnological production of VD2 and VD3 metabolites.
Probing the Interaction of Huntingtin Exon‐1 Polypeptides with the Chaperonin Nanomachine GroEL
Authors: Wälti Marielle A. , Kotler Samuel A. , Clore G. Marius
Published: March 2021

Huntington's disease arises from polyQ expansion within the exon‐1 region of huntingtin (httex1), resulting in an aggregation‐prone protein that accumulates in neuronal inclusion bodies. We investigate the interaction of various httex1 constructs with the bacterial analog (GroEL) of the human chaperonin Hsp60. Using fluorescence spectroscopy and electron and atomic force microscopy, we show that GroEL inhibits fibril formation. The binding kinetics of httex1 constructs with intact GroEL and a mini‐chaperone comprising the apical domain is characterized by relaxation‐based NMR measurements. The lifetimes of the complexes range from 100 to 400 μs with equilibrium dissociation constants (KD) of ∼1–2 mM. The binding interface is formed by the N‐terminal amphiphilic region of httex1 (which adopts a partially helical conformation) and the H and I helices of the GroEL apical domain. Sequestration of monomeric httex1 by GroEL likely increases the critical concentration required for fibrillization.
Hierarchical Silica Inverse Opals as a Catalyst Support for Asymmetric Molecular Heterogeneous Catalysis with Chiral Rh‐diene Complexes
Authors: Deimling Max , Kousik Shravan R. , Abitaev Karina , Frey Wolfgang , Sottmann Thomas , Koynov Kaloian , Laschat Sabine , Atanasova Petia
Published: March 2021

The efficacy of heterogeneous catalysis relies heavily on diffusion and distribution of reactants within catalyst supports. However, the presence of confinement, essential for reaction selectivity, drastically slows down molecular transport. Here, macro‐mesoporous silica inverse opal (SiO2−IO) films were used as a model system to study the rather unexplored molecular infiltration behavior using a probe molecule resembling a catalyst via confocal laser scanning microscopy (CLSM). CLSM analysis revealed homogeneous tracer distribution in SiO2−IO and attachment to both transport and mesopores. Bulk macro‐mesoporous SiO2−IO support was used for the attachment of mono‐ and bis‐functionalized chiral Rh‐diene complexes, and the catalytic activity and selectivity with respect to the support was studied. Lower enantioselectivity was observed with the bis‐functionalized ligand due to ligand entanglement and reduced accessibility of the active site, while the mono‐functionalized ligand gave an excellent enantioselectivity of 94 %ee in the asymmetric 1,2‐addition of triphenylboroxine to N‐tosylimines and could be recycled up to three times.
Application of nanoparticles in chiral analysis and chiral separation
Authors: Aboul‐Enein Hassan Y. , Bounoua Nadia , Rebizi Mohamed , Wagdy Hebatallah
Published: March 2021

Chiral molecules in relation to particular biological roles are stereoselective. Enantiomers differ significantly in their biochemical responses in biological environment. Despite the current advancement in drug discovery and pharmaceutical biotechnology, the chiral separation of some racemic mixtures continues to be one of the greatest challenges, because the available techniques are too costly and time consuming for the assessment of therapeutic drugs in the early stages of development worldwide.

Various nanoparticles became one of the most investigated and explored nanotechnology‐derived nanostructures especially in chirality where several studies are reported to improve enantiomeric separation of different racemic mixtures. The production of surface‐modified nanoparticles has contributed to these limitations in terms of sensitivity, accuracy, and enantioselectivity that can be optimized and therefore makes these surface‐modified nanoparticles convenient for enantiomeric identification and separation.
Addressing Environmental Challenges of Porphyrin Mixtures Obtained from Statistical Syntheses
Authors: Hölzel Helen , Muth Maximilian , Lungerich Dominik , Jux Norbert
Published: March 2021

Invited for this month's cover are the groups of Dominik Lungerich at the Yonsei University (Korea) and Norbert Jux at the Friedrich‐Alexander‐University Erlangen‐Nuernberg (Germany). The cover picture shows a laboratory bench, with instruments, equipment, and a chalkboard. Here, the question arises if in academic research exists a way to implement the philosophy of “reduce, reuse and recycle”. The recycle sign underlines the rising awareness for this topic, which is steadily gaining in importance. Especially in porphyrin sciences, using semi‐automated flash chromatography can decrease significantly the cost of consumables, such as chlorinated solvents and silica gel. With a re‐usable glass column for preparative separation, even the purification of statistical reaction mixtures can be managed, while reducing the waste and thus the environmental factor significantly. Read the full text of their Full Paper at 10.1002/cmtd.202000055.
From Chain‐ to Graphene‐like Hydroxyl‐terminated (ZnO)n Clusters with n≤6 Obtained via Zinc Dimethoxide Hydrolysis and Condensation: Ab initio Structural, Electronic, Vibrational and Optical Properties Calculations
Authors: Romero Mariano , Mombrú Dominique , Pignanelli Fernando , Faccio Ricardo , Mombrú Álvaro W.
Published: March 2021

Recent reports are focusing on the structural evolution from the atomic‐scale and also at the expenses of alkyl zinc alkoxide precursors towards (ZnO)n clusters and nanostructures with different interesting motifs, but still not much is known about their electronic properties. In this manuscript, we present a theoretical study using DFT and TD‐DFT methodologies on the hydrolysis and condensation of zinc dimethoxide precursor in its monomeric, dimeric and trimeric forms towards thermodynamically stable hydroxyl‐terminated (ZnO)n clusters with novel chain‐ and graphene‐like fashions. For all cases, distinct vibrational and optical spectra features were assigned evidencing a global monotonic decrease in the opto‐electronic gap with increasing oligomerization and cyclization stages. In addition, the electron‐affinity of all clusters was also observed to be enhanced with increasing oligomerization and cyclization stages and the electronic charge localization in ‐e charged clusters was observed to be strongly related to the presence of zinc‐oxo subunits and other particular structural features. Our calculations also indicate that the stabilization through hydroxyl termination of both chain‐ and graphene‐like ZnO clusters not only could be a promising driving force to obtain larger atomic‐scale 1D and 2D nanostructures but also envisage interesting properties, particularly as electronic acceptor materials for energy applications.
Perennial forages influence mineral and protein concentrations in annual wheat cropping systems
Authors: Clemensen Andrea K. , Grusak Michael A. , Duke Sara E. , Hendrickson John R. , Franco José G. , Archer David W. , Roemmich James N. , Liebig Mark A.
Published: March 2021

Agricultural land management may influence crop nutritional quality. However, few studies have explored potential connections between crop quality with different land management strategies. We analyzed mineral and crude protein concentrations in spring wheat grain (Triticum aestivum L.) samples from a study in Mandan, ND conducted from 2006 to 2014. The study introduced a perennial forage phase into an annual spring wheat cropping system, in three to four replicates, and previously found yield benefits and enhanced soil parameters in the perennial forage treatments. We determined whether integrating a perennial forage phase into continuous wheat would also affect crop nutritional quality by measuring wheat grain mineral and protein concentrations. Crude protein concentration was greater (p < .05) when wheat followed alfalfa (Medicago sativa L.) and increased linearly after 2–5 yr of established alfalfa. We observed comparable wheat grain crude protein and mineral concentrations between continuous annually fertilized wheat and unfertilized wheat following perennial forages. Negative correlations (p < .001) were observed between wheat grain yield and crude protein, potassium (K), magnesium (Mg), nickel (Ni), phosphorus (P), sulfur (S), and zinc (Zn) concentrations. Discriminate multivariate analyses showed, with 96% predictive accuracy, that differences in crude protein and mineral concentration were largely driven by year of wheat harvest. Differences between harvest years were likely due to timely precipitation at critical Growth Stage 3, during spikelet development. Study outcomes highlighted the important role of perennial forages and environmental factors to influence protein and mineral concentration in spring wheat grain.
An analytical model for squirrel cage induction machine with broken rotor bars derived based on the multiple coupled circuit theory and the winding function approach
Authors: Fu Qiang , Guo Qing , Zhang Wei , Cui Weimin , Zhao Ling
Published: March 2021

In this paper, a squirrel cage induction machine (SCIM) with broken rotor bars is modeled by using the multiple coupled circuit theory and the winding function approach. This analytical model includes all the spatial harmonic components of air gap magnetomotive force and is applicable to the study of transient machine behaviors. Equivalent circuits that are consistent with the topologies of healthy and faulty cage rotors are developed. The equivalent circuit for the healthy rotor of a SCIM having an integer number of rotor bars per pole is simplified further by exploiting the symmetry of the winding functions of the stator. In the equivalent circuit for a healthy rotor, inserting an independent current source in the bar that breaks in the damaged rotor, whose current is the negative of the current through the same bar, and replacing all the voltage sources in the rest of the bars with short circuits result in an equivalent circuit that can be employed to solve for the deviations in rotor mesh currents caused by bar breakage. A simulation is carried out in MATLAB/Simulink for a 2.2 kW, three‐phase, four‐pole SCIM with 28 rotor bars and a laboratory test rig is built. The effectiveness of the proposed model was validated by the good agreement of the simulation results with the experimental data.
Implementing an integrated multi‐technology platform for drug checking: Social, scientific, and technological considerations
Authors: Wallace Bruce , Hills Rory , Rothwell Jake , Kumar Deepak , Garber Ian , van Roode Thea , Larnder Ashley , Pagan Flora , Aasen Jarred , Weatherston Jorin , Gozdzialski Lea , Ramsay Margo , Burek Piotr , Azam Md. Shafiul , Pauly Bernie , Storey Margaret‐Anne , Hore Dennis
Published: March 2021

The illicit drug overdose crisis in North America continues to devastate communities with fentanyl detected in the majority of illicit drug overdose deaths. The COVID‐19 pandemic has heightened concerns of even greater unpredictability in the drug supplies and unprecedented rates of overdoses. Portable drug‐checking technologies are increasingly being integrated within overdose prevention strategies. These emerging responses are raising new questions about which technologies to pursue and what service models can respond to the current risks and contexts. In what has been referred to as the epicenter of the overdose crisis in Canada, a multi‐technology platform for drug checking is being piloted in community settings using a suite of chemical analytical methods to provide real‐time harm reduction. These include infrared absorption, Raman scattering, gas chromatography with mass spectrometry, and antibody‐based test strips. In this Perspective, we illustrate some advantages and challenges of using multiple techniques for the analysis of the same sample, and provide an example of a data analysis and visualization platform that can unify the presentation of the results and enable deeper analysis of the results. We also highlight the implementation of a various service models that co‐exist in a research setting, with particular emphasis on the way that drug checking technicians and harm reduction workers interact with service users. Finally, we provide a description of the challenges associated with data interpretation and the communication of results to a diverse audience.
Contemporary screen time modalities among children 9–10 years old and binge‐eating disorder at one‐year follow‐up: A prospective cohort study
Authors: Nagata Jason M. , Iyer Puja , Chu Jonathan , Baker Fiona C. , Pettee Gabriel Kelley , Garber Andrea K. , Murray Stuart B. , Bibbins‐Domingo Kirsten , Ganson Kyle T.
Published: March 2021

Objective

To determine the prospective associations between contemporary screen time modalities in a nationally representative cohort of 9–10‐year‐old children and binge‐eating disorder at one‐year follow‐up.

Method

We analyzed prospective cohort data from the Adolescent Brain Cognitive Development (ABCD) Study (N = 11,025). Logistic regression analyses were conducted to estimate associations between baseline child‐reported screen time (exposure) and parent‐reported binge‐eating disorder based on the Kiddie Schedule for Affective Disorders and Schizophrenia (KSADS‐5, outcome) at one‐year follow‐up, adjusting for race/ethnicity, sex, household income, parent education, BMI percentile, site, and baseline binge‐eating disorder.

Results

Each additional hour of total screen time per day was prospectively associated with 1.11 higher odds of binge‐eating disorder at 1‐year follow‐up (95% CI 1.05–1.18) after adjusting for covariates. In particular, each additional hour of social networking (aOR 1.62, 95% CI 1.18–2.22), texting (aOR 1.40, 95% CI 1.08–1.82), and watching/streaming television shows/movies (aOR 1.39, 95% CI 1.14–1.69) was significantly associated with binge‐eating disorder.

Discussion

Clinicians should assess screen time usage and binge eating in children and adolescents and advise parents about the potential risks associated with excessive screen time.
Sandpipers go with the flow: Correlations between estuarine conditions and shorebird abundance at an important stopover on the Pacific Flyway
Authors: Canham Rachel , Flemming Scott A. , Hope David D. , Drever Mark C.
Published: March 2021

Estuaries of major rivers provide important stopover habitat for migratory birds throughout the world. These estuaries experience large amounts of freshwater inputs from spring runoff. Understanding how freshwater inputs affect food supply for migrating birds, and how birds respond to these changes will be essential for effective conservation of critical estuarine habitats. We estimated trends over time in counts of Western Sandpiper (Calidris mauri) and Pacific Dunlin (Calidris alpina pacifica) during northward migration on the Fraser River estuary, British Columbia, Canada, where shorebirds feed extensively on intertidal biofilm and invertebrates. We also examined whether counts were correlated with a suite of environmental variables related to local conditions (precipitation, temperature, wind speed and direction, solar radiation, tidal amplitude, and discharge rates from the Fraser River) during a total of 540 surveys from 1991 to 2019. Counts of Western Sandpiper declined ~54% (−2.0% per annum) over the entire study period, and 23% from 2009 to 2019 (−0.9% per annum). Counts of Pacific Dunlin did not show a statistically significant change over the study period. Counts of shorebirds were lower when discharge from the Fraser River was high, which we propose results from a complex interaction between the abrupt changes in salinity and the estuarine food web related to the quantity or quality of intertidal biofilm. Counts were also higher when tidal amplitude was lower (neap tides), potentially related to longer exposure times of the mudflats than during spring tides. Effects of wind are likely related to birds delaying departure from the stopover site during unfavorable wind conditions. The negative trend in migrating Western Sandpipers is consistent with declines in nonbreeding areas as observed in Christmas Bird Counts. Understanding causes of population change in migratory shorebirds highlights the need for research on mechanistic pathways in which freshwater inputs affect food resources at estuarine stopovers.
Electrophoretic separation of multiple chiral center analyte with a three cyclodextrins mixture
Authors: La Zuo , Danel Cécile , Grolaux Gaëlle , Charton Julie , Furman Christophe , Lipka Emmanuelle
Published: March 2021

A capillary electrokinetic chromatography method (CEKC) was developed for complete stereoisomeric separation of a neutral, hydrophobic, multiple chiral center dihydropyridone analogue, a drug candidate proposed in type 2 diabetes treatment. A background electrolyte comprising three cyclodextrins was found to successfully separate the eight isomers. First an anionic cyclodextrin, the SBE‐β‐CD, was selected to allow the chiral separation of our neutral compound and partial resolutions of the eight isomers were obtained. Then, the effects of different parameters such as the nature and concentration of the other cyclodextrins added and pH of the buffer were examined. Finally, a triple CD‐system consisted of 15 mM SBE‐β‐CD plus 15 mM γ‐CD and 40 mM HP‐γ‐CD in a 50 mM borate background electrolyte at pH 10, was found to successfully separate the eight isomers. Last, the selectivity and limits of detection and quantification were evaluated for this optimized method.
Clustering Nuclear Magnetic Resonance: Machine learning assistive rapid two‐dimensional relaxometry mapping
Authors: Peng Weng Kung
Published: March 2021

Low‐field nuclear magnetic resonance (NMR) relaxometry is an attractive approach from point‐of‐care testing medical diagnosis to in situ oil‐gas exploration. One of the problems, however, is the inherently long relaxation time of the (liquid) samples, (and hence low signal‐to‐noise ratio) which causes unnecessarily long repetition time. In this work, a new class of methodology is presented for rapid and accurate object classification using NMR relaxometry with the aid of machine learning. It is demonstrated that the sensitivity and specificity of the classification is substantially improved with higher order of (pseudo)‐dimensionality (e.g., 2D‐ or multi‐dimensional). This new methodology (termed as ‘Clustering NMR’) may be extremely useful for rapid and accurate object classification (in less than a minute) using low‐field NMR.
The effect of plasma treatment process on the electrical conductivity and coating fastness of silver nanoparticles functionalized aramid fiber paper
Authors: Li Guanglu , Sun Zhenhua , Gao Songwei , Wang Yawen , Chen Shaojuan , Ma Jianwei
Published: March 2021

In this study, electrically conductive meta‐aramid fiber paper (MAFP) was prepared by combining low‐temperature plasma treatment and electroless plating. The influence of various plasma treatment parameters including nozzle speed, plasma cycle time and nozzle height on the electrical conductivity, washing fastness and bending fastness of silver‐coated MAFP was investigated. The results show that low‐temperature plasma treatment etched the surface of meta‐aramid fiber and increased the oxygen content on the MAFP surface. The optimal plasma treatment condition is: nozzle speed of 1 m/min, plasma cycle time of 80%, and nozzle height of 4–5 cm. The electrical resistance of the silver‐plated MAFP pre‐treated under this condition reached as low as 0.15 Ω/sq. In addition, the silver‐plated MAFP maintained high electrical conductivity (sheet resistance below 0.5 Ω/sq) after five washing cycles and 1000 bending cycles.
Accumulation of Insensitive Munition Compounds in the Earthworm Eisenia andrei from Amended Soil: Methodological Considerations for Determination of Bioaccumulation Factors
Authors: Lotufo G.R. , Boyd R.E. , Harmon A.R. , Bednar A.J. , Smith J.C. , Simini M. , Sunahara G.I. , Hawari J. , Kuperman R.G.
Published: March 2021

The present study investigates the bioaccumulation of the insensitive munition compounds 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO), developed for future weapons systems to replace current munitions containing sensitive explosives. The earthworm Eisenia andrei was exposed to sublethal concentrations of DNAN or NTO amended in Sassafras sandy loam. Chemical analysis indicated that 2- and 4-amino-nitroanisole (2-ANAN and 4-ANAN, respectively) were formed in DNAN-amended soils. The SumDNAN (sum of DNAN, 2-ANAN, and 4-ANAN concentrations) in soil decreased by 40% during the 14-d exposure period. The SumDNAN in the earthworm body residue increased until day 3 and decreased thereafter. Between days 3 and 14, there was a 73% decrease in tissue uptake that was greater than the 23% decrease in the soil concentration, suggesting that the bioavailable fraction may have decreased over time. By day 14, the DNAN concentration accounted for only 45% of the SumDNAN soil concentration, indicating substantial DNAN transformation in the presence of earthworms. The highest bioaccumulation factor (BAF; the tissue-to-soil concentration ratio) was 6.2 ± 1.0 kg/kg (dry wt) on day 3 and decreased to 3.8 ± 0.8 kg/kg by day 14. Kinetic studies indicated a BAF of 2.3 kg/kg, based on the earthworm DNAN uptake rate of 2.0 ± 0.24 kg/kg/d, compared with the SumDNAN elimination rate of 0.87 d–1 (half-life = 0.79 d). The compound DNAN has a similar potential to bioaccumulate from soil compared with trinitrotoluene. The NTO concentration in amended soil decreased by 57% from the initial concentration (837 mg NTO/kg dry soil) during 14 d, likely due to the formation of unknown transformation products. The bioaccumulation of NTO was negligible (BAF ≤ 0.018 kg/kg dry wt). Environ Toxicol Chem 2021;40:1713–1725. © 2021 SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.
Tolerability of lithium: A naturalistic discontinuation study in older inpatients (≥60 years)
Authors: Flapper Marinke , van Melick Els , van Campen Jos , Schutter Natasja , Kok Rob
Published: March 2021

Objectives

Lithium is one of the most effective treatment options in both bipolar disorder and treatment‐resistant depression. The use of lithium in older patients declined during the last decades, probably resulting in undertreatment of older patients. To investigate how well lithium is tolerated in old age, we aimed to determine the frequency, reasons, and possible predictors of discontinuation due to adverse effects in a cohort of inpatients ≥60 years who had started with lithium.

Methods

We performed a retrospective cohort study based on chart reviews. Participants were in treatment at Parnassia Group at The Hague, The Netherlands. After inclusion (between January 2010 and December 2016), participants were followed until April 2017, when we performed data extraction and analysis.

Results

In our sample of 135 patients (median age 69 years, median follow‐up duration 18 months), 49 (36.3%) participants discontinued lithium. Only a minority (11 [8.1%]) of the participants discontinued solely due to adverse effects. The majority discontinued lithium due to psychiatric (18, 5%) reasons (most commonly mentioned within this subgroup: lack of effectiveness and noncompliance) or a combination of reasons (7.4%). None of the factors we studied (age, gender, Charlson Comorbidity Index, polypharmacy, renal function, and neurological history) were significantly associated with discontinuation due to adverse effects.

Conclusions

The frequency of lithium discontinuation in our cohort was in range with frequencies reported in younger patients. Older age itself should not be a reason to withhold lithium treatment.
Global health and innovation: A panoramic view on health human resources in the COVID‐19 pandemic context
Authors: Denis Jean Louis , Côté Nancy , Fleury Charles , Currie Graeme , Spyridonidis Dimitrios
Published: March 2021

While policy‐makers in many jurisdictions are paying increasing attention to health workforce issues, human resources remain at best only partially aligned with population health needs. This paper explores the governance of human resources during the pandemic, looking at the Quebec health system as a revelatory case. We identify three issues related to health human resource (HHR) policies: working conditions, recognition at work and scope of practice. We empirically probe these issues based on an analysis of popular media, policy reports and participant observation by the lead authors in various forums and research projects. Using an integrated model of HHR, we identify major vulnerabilities in this domain. Persistent labour shortages, endemic deficiencies in working environments and inequity across occupational categories limit the ability to address critical HHR issues. We propose three ways to eliminate HHR vulnerabilities: reorganize work through participatory initiatives, implement joint policy making to rebalance power across the health workforce, and invest in the development of capacities at all system levels.
The effect of combined exposure of zinc and nickel on the development of zebrafish
Authors: Yang Yongmeng , Yu Yue , Zhou Rong , Yang Yan , Bu Yuanqing
Published: March 2021

Excessive accumulation of Zn2+ or Ni2+ can cause various problems to aquatic animals. In this study, the developmental toxicity induced by individual or combined exposure of Zn2+ and Ni2+ to zebrafish embryos and larvae were evaluated to better understand the interaction between Zn2+ and Ni2+. Both of individual and combined exposure of Zn2+ and Ni2+ could cause obvious developmental toxicity, which mainly occurred after hatching, at a concentration‐dependent manner. The calculated 168‐h LC50 were 2.79 mg/L for Zn2+ and 7.44 mg/L for Ni2+. The interaction of Zn2+ and Ni2+ based on mortality was found to be an antagonism. Various malformations, including tail curving, spinal curvature, pericardial edema, and yolk sac edema, were observed with significant effects on body length and heartbeat rates after exposure of Zn2+ and Ni2+. Meanwhile, some genes related to cardiovascular development and bone formation were mainly down‐regulated by the individual and combined exposure of Zn2+ and Ni2+. The individual exposure was more toxic than combined exposure because the interaction of Zn2+ and Ni2+ was determined to be an antagonism. The down‐regulation of genes related to cardiovascular development and bone formation may contribute to the observed malformation and decreases of body length and heartbeat rates.
The impact of free returns on online purchase behavior: Evidence from an intervention at an online retailer
Authors: Patel Pankaj C. , Baldauf Christoph , Karlsson Stefan , Oghazi Pejvak
Published: March 2021

Whether free returns create economic value for online retailers is a question of increasing importance. Using order‐level data from an online fashion retailer in Sweden, we investigate the introduction of free returns for customers in Denmark starting November 1, 2017, but not for customers in Sweden, Norway, Finland, France, Germany, and the rest of Europe (the control group). Using difference‐in‐differences, with and without sample matching, the introduction of free returns increased the order bill by 54.95 Swedish Krona (SEK) (9.15%), product variety per order by 0.057 (8.74%), gross margin per order by 29.90 SEK (9.71%), and returns by 0.195 items per order (7.86%). This likelihood of increased returns was generally similar across different product categories. The findings are robust to parallel trends, event studies, placebo effects, alternative control groups (with Scandinavian countries, Sweden and Norway), country‐time trends, and correlations between outcome variables. Based on back‐of‐the‐envelope calculations, the cost of offering free returns is greater than the increase in gross profit driven by free returns. Though our results show that free returns may not be of short‐term benefit, retailers must also consider the long‐term strategic implications of free returns.
Nanoencapsulation in low‐molecular‐weight chitosan improves in vivo antioxidant potential of black carrot anthocyanin
Authors: Chatterjee Niladri Sekhar , Dara Pavan Kumar , Perumcherry Raman Sreerekha , Vijayan Divya K , Sadasivam Jayashree , Mathew Suseela , Ravishankar Chandragiri Nagarajarao , Anandan Rangasamy
Published: March 2021

BACKGROUND

Anthocyanins are flavonoids that are potential antioxidant, anti‐inflammatory, anti‐obesity, and anti‐carcinogenic nutraceutical ingredients. However, low chemical stability and low bioavailability limit the use of anthocyanins in food. Nanoencapsulation using biopolymers is a recent successful strategy for stabilization of anthocyanins. This study reports the development, characterization, and antioxidant activity of black carrot anthocyanin‐loaded chitosan nanoparticles (ACNPs).

RESULTS

The ionic gelation technique yielded the ACNPs. The mean hydrodynamic diameter d and polydispersity index PDI of chitosan nanoparticles and ACNPs were found to be d = 455 nm and PDI = 0.542 respectively for chitosan nanoparticles and d = 274 nm and PDI = 0.376 respectively for ACNPs. The size distribution was bimodal. The surface topography revealed that the ACNPs are spherical and display a coacervate structure. Fourier transform infrared analysis revealed physicochemical interactions of anthocyanins with chitosan. The loading process could achieve an encapsulation efficiency of 70%. The flow behavior index η of encapsulated ACNPs samples revealed Newtonian and shear thickening characteristics. There was a marginal reduction in the in vitro antioxidant potential of anthocyanins after nanoencapsulation, as evidenced from 2,2‐diphenyl‐1‐picrylhydrazyl, ferric reducing antioxidant power, and 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid) assays. Interestingly, the in vivo antioxidant potential of anthocyanins improved following nanoencapsulation, as observed in the serum antioxidant assays.

CONCLUSION

The optimized nanoencapsulation process resulted in spherical nanoparticles with appreciable encapsulation efficiency. The nanoencapsulation process improved the in vivo antioxidant activity of anthocyanins, indicating enhanced stability and bioavailability. The promising antioxidant activity of the ACNPs suggests a potential for utilization as a nutraceutical supplement. © 2021 Society of Chemical Industry.
Verification of data in a nationwide transanal total mesorectal excision registry in China
Authors: An Yong‐Bo , Yao Hong‐Wei , Yang Xuan‐Hua , Zhang Xiao , Zhang Zhong‐Tao
Published: March 2021

Background and Objectives

Transanal total mesorectal excision is a surgical procedure for mid‐ and low rectal cancer. The Chinese TaTME Registry Collaborative is a nationwide database collecting information on patients who have undergone this procedure.

Methods

Centers were invited by the registry committee to participate in a three‐part data audit project: remote audits for data completeness and deviation values, onsite source verification of data accuracy, and an online survey of the characteristics of data managers.

Results

Twenty‐three tertiary centers participated in this project. The median case volume registered by the centers was 51 (interquartile range, 25–89). The overall data completeness for 30 verified variables was 89.1%. Eight centers achieved a high data completeness rate (>95%). The source data of eight centers were verified onsite. The overall accuracy rate was 90.4% (85.3%–97.6% across centers). Postoperative complications, mortality, and proximal/distal resection margin involvement were accurately reported in >95% of cases. The data completeness rate was higher if the data manager was a surgeon/surgical resident (94.2% vs. 84.8%, p = 0.045).

Conclusions

The completeness and accuracy of the data in the Chinese TaTME Registry Collaborative are acceptable. The quality of the data is highest when entered by colorectal surgeons and residents.
Vestibular Impairments on Objective Diagnostic Tests in HIV+ Women and Control Men and Women
Authors: Cohen Helen S. , Plankey Michael W. , Sangi‐Haghpeykar Haleh
Published: March 2021

Objective

To describe the value of two vestibular test batteries across ages in healthy men and women for detecting vestibular disorders and to compare the occurrence of vestibular disorders in the healthy adult population and women with human immunodeficiency virus (HIV) disease.

Study Design

Two groups were tested on the battery of objective diagnostic tests of the vestibular system.

Setting

Two tertiary care centers.

Subjects

Healthy controls (284 women and 105 men) and women (63) with HIV/AIDS (HIV+) who are being followed up in a longitudinal study of HIV. They were tested on objective diagnostic tests of the vestibular system.

Results

In all age decades, healthy controls had evidence of vestibular impairment, significantly more in older adults. HIV+ subjects, all females, did not differ from healthy control females.

Conclusion

These data suggest that at all ages, people do have decreased vestibular function, even young, asymptomatic, and apparently healthy adults. HIV disease, itself, does not cause an increased prevalence of peripheral vestibular disorders when HIV is controlled on antiretroviral medication.

Level of Evidence

2 Laryngoscope, 131:E2318–E2322, 2021
Moisture‐Resistant and Mechanically Strong Polyimide‐Polymethylsilsesquioxane Hybrid Aerogels with Tunable Microstructure
Authors: Xi Shuang , Wang Xiaodong , Liu Ting , Zhang Ze , Zhang Xiaoxue , Shen Jun
Published: March 2021

Moisture‐resistant and mechanically strong polyimide (PI)‐polymethylsilsesquioxane hybrid aerogels with doubly cross‐linked structures are synthesized through sol–gel technology and supercritical CO2 fluid drying. By using bis(trimethoxysilylpropyl) amine as a cross‐linker, the end‐capped polyamide acid derived from biphenyl‐3,3′,4,4′‐tetracarboxylic dianhydride and 4,4′‐oxydianiline is cross‐linked with a silica network using methyltrimethoxysilane as the silica source precursor. The resultant hybrid aerogels show low density (0.12–0.15 g cm−3), low thermal conductivity (0.032–0.049 W m−1 K−1), high hydrophobicity (125–140°) and good thermal stability (above 435 °C) with tunable microstructure. With the increase of silica sol volume, the microstructure of hybrid aerogels transforms from fibrous network to hierarchical microstructure. Aerogels with high content of silica sol exhibit good moisture resistance, high Young's modulus (Max. 19.6 MPa), and high specific modulus (Max. 131 kN m kg−1), which are attributed to their unique hierarchical microstructure with a sheet skeleton. These hybrid aerogels are promising in the fields of thermal insulation, aerospace applications and so on.
A Practical and Efficient Synthesis of Uniform Conjugated Rod‐Like Oligomers
Authors: Hahn Daniel , Schneider Rebekka V. , Foitzik Elena , Meier Michael A. R.
Published: March 2021

Herein, a more practical and efficient synthesis protocol for the preparation of uniform rod‐like oligo(1,4‐phenylene ethynylene)s (OPE)s is presented. Applying an iterative reaction cycle consisting of a decarboxylative coupling reaction and a saponification of an alkynyl carboxylic ester, a uniform pentamer is obtained in ten steps with 14% overall yield. The copper‐free conditions prevent homocoupling until the trimer stage, resulting in a significantly easier work‐up of the products. Homocoupling is observed from the tetramer stage on, but a simple variation of the work‐up procedure also yields the uniform tetramer and pentamer. A thorough comparison with the commonly used and described Sonogashira approach reveals that with the new presented strategy, OPEs can be built in similar overall yield, but easier purification and in a quarter of the time. All oligomers are fully characterized by proton and carbon nuclear magnetic resonance spectroscopy (NMR), mass spectrometry (MS), size‐exclusion chromatography (SEC), and infrared spectroscopy (IR).
A Highly Selective Polymer Material using Benzo‐9‐Crown‐3 for the Extraction of Lithium in Presence of Other Interfering Alkali Metal Ions
Authors: Oral Iklima , Abetz Volker
Published: March 2021

The recovery of lithium from global water resources continues to be challenging due to interfering metal ions with similar solution properties. Hence, a lithium‐selective diblock copolymer system containing crown ethers (CEs) is developed. A polystyrene‐block‐poly(methacrylic acid) diblock copolymer is synthesized first via a one‐pot solution–emulsion reversible addition–fragmentation chain transfer polymerization. A subsequent Steglich esterification yields the CE functionalized polymer. The complexation properties with different alkali metals are first investigated by liquid−liquid extraction (LLE) in dichloromethane (DCM) − water systems using free benzo‐9‐crown (B9C3), benzo‐12‐crown‐4 (B12C4), and benzo‐15‐crown‐5 (B15C5) CEs as reference components, followed by the correspondingly CE‐functionalized polymers. Extraction complexation constants in the aqueous phase are determined and the impact of the complexation constants on the extractability is estimated. The B9C3 CE is especially appealing since it has the smallest cavity size among all CEs. It is too small to complex sodium or potassium ions; however, it forms sandwich complexes with a lithium‐ion resulting in extraordinary complexation constants in polymer systems avoiding other interfering alkali metal ions. On this basis, a new material for the efficient extraction of lithium ion traces in global water resources is established.
Ring‐Opening Metathesis Polymerization of Norbornene‐Based Monomers Obtained via the Passerini Three Component Reaction
Authors: Barther Dennis , Moatsou Dafni
Published: March 2021

Ring‐opening metathesis polymerization is a robust method to synthesize a variety of polymers by using ring‐strained molecules as monomers, e.g., norbornenes. However, the synthesis of monomers with multiple functional groups remains a challenge, albeit peptide functional norbornenes have previously been used. Here, the Passerini three component reaction is exploited to synthesize norbornenes with two variable functional groups varying in bulkiness and distance from the polymerizable alkene. The results indicate that the functional groups do not affect the kinetics of the polymerization, whereas the length of the linker has a minor effect. Furthermore, a diblock‐type copolymer is synthesized in a one‐pot fashion, also indicating good control of the polymerization process. The thermal properties of all polymers are evaluated, highlighting the effect of monomer composition. This synthetic approach can be transferred to a variety of compounds, thus promising highly diverse polymers with complex compositions and architectures.
Synthesis of Polymers Bearing a Chiral Backbone via Stereospecific Ionic Ring‐Opening Polymerization of Chiral Donor‐Acceptor Cyclopropanes
Authors: Emmerich Alexis , Daniliuc Constantin G. , Studer Armido
Published: March 2021

The stereospecific ionic ring‐opening polymerization of various donor‐acceptor cyclopropanes is reported. The chiral cyclopropane monomers are readily prepared with established methodology and stereospecific polymerization is best conducted with a catalytic amount of MgBr2 serving as a Lewis acid and as an initiator. Polymers with molecular masses of up to 7800 g mol−1 containing a stereocenter in every repeating unit are obtained and the substituents of the monomers can be readily varied to access a novel class of chiral polymers.
Management of Secondary Poor Response to Botulinum Toxin in Cervical Dystonia: A Multicenter Audit
Authors: Tucker Harry , Osei‐Poku Foster , Ashton Diane , Lally Rachael , Jesuthasan Aaron , Latorre Anna , Bhatia Kailash P. , Alty Jane E. , Kobylecki Christopher
Published: March 2021

Background

Botulinum toxin A (BoNT‐A) is an effective treatment for cervical dystonia. Nevertheless, up to 30% to 40% patients discontinue treatment, often because of poor response. The British Neurotoxin Network (BNN) recently published guidelines on the management of poor response to BoNT‐A in cervical dystonia, but adherence to these guidelines has not yet been assessed.

Objectives

To assess adherence to and usefulness of BNN guidelines in clinical practice.

Methods

We undertook a retrospective medical notes audit of adherence to the BNN guidelines in 3 United Kingdom tertiary neurosciences centers.

Results

Of 76 patients identified with poor response, 42 (55%) had a suboptimal response and, following BNN recommendations, 25 of them (60%) responded to adjustments in BoNT dose, muscle selection or injection technique. Of the remaining 34 (45%) patients with no BoNT response, 20 (59%) were tested for immune resistance, 8 (40%) of whom showed resistance. Fourteen (18%) of all patients were switched to BoNT‐B, and 27 (36%) were referred for deep brain stimulation surgery. In those not immune to BoNT‐A, clinical improvement was seen in 5 (41%) after adjusting their dose and injection technique.

Conclusion

Our audit shows that optimizing BoNT dose or injection strategy largely led to improvements in those with suboptimal response and in those reporting no response without resistance. It would be helpful to standardize investigations of potential resistance in those with no therapeutic response.
Impact of detrusor underactivity on the postoperative outcomes after benign prostatic enlargement surgery
Authors: Plata Mauricio , Santander Jessica , Trujillo Carlos Gustavo , Bravo‐Balado Alejandra , Robledo Daniela , Higuera Tatiana , Caicedo Juan Ignacio
Published: March 2021

Introduction and Objective

Previous studies suggest that men with detrusor underactivity (DUA) have less symptomatic improvement after prostate surgery than those with normal contractility, but the available data is controversial. We aim to determine the differences in functional outcomes of patients with or without DUA who underwent photovaporization of the prostate (PVP) with GreenLight™180 W XPS.

Methods

A cohort of patients with lower urinary tract symptoms (LUTS) who underwent PVP between 2012 and 2019 was evaluated. Patients were stratified according to bladder contractility index (BCI). DUA was defined as BCI < 100. Those with normal contractility (BCI = 100–150) were included in Group 1, and those with DUA (BCI < 100) in Group 2. Primary outcomes were symptomatic improvement defined as a reduction ≥ 4 points in the international prostate symptom score (IPSS) and a reduction of at least 1 point in the quality of life (IPSS‐QoL). Complications according to the Clavien–Dindo classification were also recorded.

Results

A total of 271 patients who underwent PVP with GreenLight™ and met the inclusion criteria were assessed. Group 1 included 158 patients, while Group 2 included 113 patients. Mean follow‐up was 24 months. Patients with normal contractility had a median reduction of 11 points (18.9 ± 8.0 to 7.1 ± 7.0) while patients with DUA had a median reduction of 10 points (19.3 ± 6.9 to 8.6 ± 8.4) in IPSS score; these differences were not statistically significant (p = .20). Patients in Group 1 had a 1.92 higher chance of QoL improvement (OR, 1.92; 90% CI, 1.10–3.37), compared to those in Group 2. Failure to void after PVP was most frequently reported in DUA patients (OR, 2.36; 90% CI, 1.26–4.43). Sociodemographic characteristics, intraoperative complications, conversion rates, hospital stay, and urinary catheterization time were similar between groups.

Conclusions

Patients with LUTS, regardless of their BCI, improved their symptoms after PVP according to the IPSS. However, patients with DUA were more likely not to improve their QoL after the procedure and had a higher chance of failure to void in the immediate postoperative period. An appropriate counseling process with the patient discussing possible outcomes based on these findings should be encouraged.
Trends in the use and costs of intermittent urinary catheters in the Netherlands from 1997 to 2018: A population‐based observational study
Authors: Berendsen Sophie A. , van Doorn Tess , Blok Bertil F. M.
Published: March 2021

Aim

To obtain insight into the the use and costs of clean intermittent catheterization (CIC) in the Netherlands from 1997 to 2018.

Methods

For this population‐based study, data on the use and costs of disposable catheters were provided by the Drug Information Project database. This database contains information about the Dutch insured population, which increased from 9.9 to 17.1 million persons between 1997 and 2018 (64%–100% of the Dutch population). The following trends were evaluated: (1) CIC users, (2) distribution of users by gender and age‐group, (3) distribution of users by neurogenic and non‐neurogenic cause for CIC, (4) total costs, and (5) costs per user. Total users are adjusted for the Dutch population. Costs are corrected for inflation and expressed in euros.

Results

Extramural use of CIC increased from 14,258 users in 1997 to 45,909 users in 2018. CIC users per 100,000 persons nearly tripled from 92 users to 267 users. Male CIC users almost quadrupled from 92 to 334 per 100,000 insured persons, whereas female users more than doubled from 91 to 201 per 100,000 insured persons. In 2018, 49% of the users had a non‐neurogenic cause for CIC. Total costs increased from 16.4 million euros in 1997 to 74.6 million euros in 2018. Costs per user rose from 1151 to 1624 euros (41.1%).

Conclusions

The use and costs of disposable catheters in the Netherlands increased substantially over the past two decades. Non‐neurogenic bladder patients represent 49% of the population on CIC, which has not been described before in the literature.