bluuebunny/crossref_metadata_2025 huggingface dataset:
Degradation of flame retardance: A comparison of ethylene‐vinyl acetate and low‐density polyethylene cables with two different metal hydroxides
Authors: Tan Yi , Wachtendorf Volker , Kukofka Tobias , Klack Patrick , Ruder Jörg , Lin Xuebao , Schartel Bernhard
Published: October 2020

The durability of flame retardancy is a challenge for cables over long lifetimes. The degradation of flame retardance is investigated in two kinds of exposures, artificial weathering and humidity. In this basic study, typical mineral flame retardants in two polymers frequently used in cable jackets are investigated to get the fundamental picture. Aluminum hydroxide (ATH) and magnesium hydroxide (MDH) are compared in ethylene‐vinyl acetate (EVA), and further in EVA and linear low‐density polyethylene (LLDPE) cables containing the same ATH. The changes in chemical structure at the surface are studied through attenuated total reflectance Fourier transform infrared spectroscopy (ATR‐FTIR), the formation of cracks, and changes in color are investigated. The cone calorimeter and a bench scale fire testing cable module are utilized to evaluate the fire behavior of the cables. Although the flame retardancy deteriorated slightly, it survived harsh exposure conditions for 2000 h. Compared to EVA/MDH and LLDPE/ATH, the fire behavior of EVA/ATH is the least sensitive. Taken together, all of the results converge to estimate that there will be no problem with flame retardancy performance, for materials subjected to natural exposure for several years; the durability of fire retardancy is questionable for longer periods, and thus requires further investigation.
Biodegradability and improved mechanical performance of polyhydroxyalkanoates/agave fiber biocomposites compatibilized by different strategies
Authors: Gallardo‐Cervantes Miguel , González‐García Yolanda , Pérez‐Fonseca Aida Alejandra , González‐López Martín Esteban , Manríquez‐González Ricardo , Rodrigue Denis , Robledo‐Ortíz Jorge Ramón
Published: October 2020

In this work, biocomposites made of polyhydroxyalkanoates (PHA) with natural fibers were produced via compression molding. In particular, polyhydroxybutyrate (PHB) and polyhydroxybutyrate‐co‐hydroxyvalerate (PHBV) were reinforced with 20 wt% of agave fibers. Different compatibilization strategies were investigated to improve the fiber‐matrix interaction: fiber surface treatment in PHA solution, fiber surface treatment in maleated PHA solution, fiber propionylation, and extrusion with maleated PHA. The biocomposites were characterized in terms of morphology, mechanical properties, water absorption, and biodegradability by CO2production tracking. In general, fiber propionylation was the best strategy for mechanical properties enhancement and water uptake decreasing. Biocomposites with propionylated fibers showed improved flexural strength (170% for PHB and 84% for PHBV). The flexural modulus was also enhanced with propionylated fibers up to 19% and 18% compared to uncompatibilized biocomposites (PHB and PHBV, respectively). Tensile strength increased by 16% (PHB) and 14% (PHBV), and the water absorption was reduced using propionylated fibers going from 6.6% to 4.4% compared with biocomposites with untreated fibers. Most importantly, the impact strength was also improved for all biocomposites by up to 96% compared with the neat PHA matrices. Finally, it was found that the compatibilization did not negatively modify the PHA biodegradability.
Polyamine microcapsules featured with high storage stability used for one‐component epoxy adhesive
Authors: Ni Dong , Luo Yan , Cong Yuxiang
Published: October 2020

One‐component epoxy adhesives have great promising prospects in industrial applications. However, it faces the challenge to reduce the activity of curing agents for achieving long‐term storage and controlled release. Microencapsulation is a feasible and effective solution. In this paper, multi‐polyaniline (MPAN) was successfully encapsulated with polyetherimide (PEI), a thermoplastic resin, as the shell material by using solvent evaporation method with dichloromethane (DCM) as solvent. The impacts of different preparation parameters on the structure and properties of microcapsules were investigated by single variable control method. It is found that the resulted microcapsules under the optimal process parameters, namely PVA concentration 1 wt%, core/shell mass ratio 1:1 and stirring rate 700 rpm, exhibits a smooth and dense spherical surface with an average particle size concentrated around 17.8 μm. Compared with the pure curing agent, the encapsulated curing agent effectively prolonged the shelf life of the epoxy adhesive at 40°C for at least 60 days, indicating excellent storage stability. The microencapsulated MPAN curing agent prepared in our research is of potential applications in the fields of electronic component bonding, potting and circuit board sealing due to its high storage stability and encapsulation efficiency (74%).
A highly elastic and sensitive sensor based on GSP/HPAM composited hydrogel
Authors: Luo Chunhui , Wei Ning , Fu Weinxin
Published: October 2020

Development of conductive hydrogels to mimic the structures and properties of human skin has attracted enormous scientific interests. However, applications of such materials are often restricted by their poor mechanics and moderate sensitivities. Herein, a highly‐stretchable, self‐healing, and conductive hydrogel, comprised of grape seed extracted polymer and hydrophobically associated polyacrylamide (GSP‐HPAM), was fabricated by simple mixing and in‐situ polymerization. Compared with the single HPAM gels, the rigid GSP polymer could form sufficient hydrogen bonds and ionic interactions, which endowed the gel with effective energy dissipation mechanism and greatly improved the uniformity of network. As a result, the GSP‐HPAM gel exhibited enhanced mechanics, that is, the tensile strength, strain, and compression stress of GSP‐HPAM hydrogel were 0.7 MPa, 3000% and 28.3 MPa, respectively. Furthermore, the gel demonstrated linear strain‐dependant conductivity between 0% and 1000% with gauge factor around 3.43, superior to most hydrogel‐based strain sensors. In addition, the gel was able to monitor human body motion, such as, finger bending and pulse rate. This multiple functional gel might find potential applications in artificial skin, soft robotics, and wearable devices.
Chitosan/gelatin‐based bioactive and antibacterial coatings deposited via electrophoretic deposition
Authors: Nawaz Aneeqa , Ur Rehman Muhammad Atiq
Published: October 2020

The fabrication of biocompatible and antibacterial coatings on metallic implants remains a significant challenge for load‐bearing orthopedic implants. This study focuses on the electrophoretic deposition of chitosan/gelatin/Ag‐Mn doped mesoporous bioactive glass nanoparticles (Ag‐Mn MBGNs) composite on the PEEK/bioactive glass layer (called as multi‐structured coatings), which had been deposited electrophoretically on 316L stainless steel. The EPD parameters for the deposition of the chitosan/gelatin/Ag‐Mn MBGNs coatings were optimized via Taguchi design of experiment approach. Scanning electron microscopy images confirmed that the chitosan/gelatin/Ag‐Mn MBGNS layer was deposited on the PEEK/BG layer. The addition of biologically active metallic ions (Mn and Ag) and molecules (chitosan) showed a strong effect on the growth of bacteria. Moreover, the inclusion of Mn and Ag showed a negligible toxic effect on the bioactivity (the ability of the coating to form a bond with the natural bone) of the coatings. Furthermore, the multi‐structured coatings presented appropriate wettability and surface roughness for orthopedic applications. Overall, this study provides a direct solution to improve the bioactivity, antibacterial activity, and surface properties of deposited chitosan/gelatin coatings on orthopedic implants that are more manufacturable and translational from research to an industrial scale.
Chitosan hydrogel loaded with Aloe vera gel and tetrasodium ethylenediaminetetraacetic acid (EDTA) as the wound healing material: in vitro and in vivo study
Authors: Salehi Majid , Zamiri Sina , Samadian Hadi , Ai Jafar , Foroutani Laleh , Ai Arman , Khanmohammadi Mehdi
Published: October 2020

The main aim of the current study was to develop a chitosan hydrogel containing Aloe vera gel and Ethylenediaminetetraacetic acid (EDTA) as the wound healing materials. Chitosan with the concentration of (2% w/v) was prepared in AA (0.5%, v/v) and Tetrasodium EDTA (0.01% w/w) and AV (0.5% v/v) were added to the prepared polymer solution. As prepared solution was cross‐linked by β‐GP with the weight ratio of 1/6 w/w (1 chitosan and 6 β‐GP). The characterization of the hydrogels showed that the hydrogels have porous structures and interconnected pores with the pores size range from 41.5 ± 14 to 48.3 ± 11 μm. The swelling and weight loss measurements of the hydrogels showed that the hydrogels could swell up to 240% of their initial weight during 8 h and loss 79.7 ± 3.5% of the initial weight during 14 days. The antibacterial studies depicted that the prepared Cs/tEDTA/AV hydrogel inhibited the growth of Staphylococcus aureus (the minimum inhibition concentration, MIC of 73 ± 4.8) and Pseudomonas aeruginosa (the MIC of 40 ± 7.9). Moreover, the prepared hydrogels were hemocompatible (Cs/tEDTA/AV: OD of 0.24 ± 0.30) and biocompatible (Cs/tEDTA/AV: OD of 0.38 ± 0.01). At the final stage, the wound healing assessments in the animal model revealed that the application of the prepared hydrogels effectively enhanced the wound healing process. In conclusion, the results confirmed the efficacy of the prepared hydrogels as the wound healing materials.
Composite Spectra, Paper XXIII: HD 69479/80, a 90‐day binary with a cool‐giant primary
Authors: Griffin R. Elizabeth , Griffin Roger F.
Published: October 2020

HD 69479/80 is a composite‐spectrum binary whose components are a late‐G giant and an early‐A dwarf. The orbit has a period of only 91 days (which seems short for a system containing a cool giant with a radius of ∼13 solar radii), and a very small, but probably significantly non‐zero, eccentricity. We separated the component spectra by a procedure of spectral subtraction, using a standard single giant spectrum as a template, and found the closest match to the spectrum of the cool component to be that of 15 Cyg (G8 III). We measured the radial velocity of the secondary component from each uncovered spectrum, solved the SB2 orbit for the system, and derived a mass ratio m1/m2 of 1.318. Fitting synthetic spectra to the spectra of the secondary component indicated a Teff of 9250 K, log g = 3.75, and a rotational velocity of ∼90 km s−1. We determined the difference in absolute magnitude, δV, between the component stars to be 1.07 mag, the late‐type component being the brighter; we could thence calculate radii and luminosities for both components, plot their H–R diagram positions, and fit evolutionary tracks. The best‐fitting tracks indicated masses of 2.9 M⊙ for the giant and 2.2 M⊙ for the dwarf, which was fully in keeping with the mass ratio given by the SB2 orbit. The track for the dwarf star confirms that this component has begun to evolve away from the ZAMS. Fitting the corresponding isochrone to those H–R diagram positions indicated a log (age) of the system of approximately 8.60 Gyr since the cool star evolved from the ZAMS, which is a little younger than the ages deduced for many cool giants. We also detected the λ 6707‐Å lithium line in the spectrum of the giant component, thus adding to the evidence that it is near the start of its primary ascent of the red‐giant branch.
Assessment and management of new and emerging risks for Europe's dietary supplement companies operating with botanicals
Authors: Delisi Riccardo , Daglia Maria , Pagliaro Mario
Published: October 2020

This study identifies new and emerging risks in the botanicals sector with the aim of fostering the success of nutraceutical and dietary supplement companies based on quality, product safety, and consumer trust. Focusing on the Italian nutraceutical market, an analysis was conducted based on interviews with experts. The outcomes of the analysis and the resulting guidelines on how to manage safety and quality by preventing risk at firms commercializing botanical‐based nutraceuticals and dietary supplements are of direct relevance to industry practitioners and to bioeconomy and biotechnology scholars. © 2020 Society of Industrial Chemistry and John Wiley & Sons Ltd
Mechanism and optimization of supramolecular complexation‐enhanced fluorescence spectroscopy for the determination of SN‐38 in plasma and cells
Authors: Zhao Kena , Guo Tao , Sun Xian , Xiong Ting , Ren Xiaohong , Wu Li , Yang Rui , Sun Huimin , Shi Senlin , Zhang Jiwen
Published: October 2020

Quantitative detection of two different forms of SN‐38 in biological samples is, currently, cumbersome and difficult. A revisit to the mechanism of supramolecular complexation‐enhanced fluorescence spectroscopy helps to optimize the determination of SN‐38 in plasma and the cellular pharmacokinetics in A549 cells based on the supramolecular complexation. Firstly, the inclusion mechanism dominated by thermodynamic constants was determined by measuring kinetic/thermodynamic parameters (kon, koff, ΔG, ΔH, ΔS). On this basis, the best effect of fluorescence sensitization was optimized through screening the interaction conditions (cyclodextrin species and concentrations, drug levels, temperature, pH of the buffer, and reaction time). Furthermore, the proportional relationship between the concentration of the inclusion complex and the fluorescence intensity was confirmed. Finally, a highly sensitive, selective spectrofluorimetric method was established and validated for quantitative analysis of the lactone and carboxylate molecular states of SN‐38 plasma levels in rats and cell membrane transfer kinetics in A549 cell lines. The limits of detection for the lactone and carboxylate forms in plasma were found to be 0.44 ng·ml−1 and 0.28 ng·ml−1, respectively. Precision and accuracy met the requirements of biological samples analysis. The proposed detection method provided a reference for elucidating the biodistribution of SN‐38.
Hybrid Conversion of5‐Hydroxymethylfurfural to5‐Aminomethyl‐2‐furancarboxylic acid: Toward New Bio‐sourced Polymers
Authors: Lancien Antoine , Wojcieszak Robert , Cuvelier Eric , Duban Matthieu , Dhulster Pascal , Paul Sébastien , Dumeignil Franck , Froidevaux Renato , Heuson Egon
Published: October 2020

Hybrid catalysis, which combines chemo‐ and biocatalytic benefits, is an efficient way to address green chemistry principles.5‐Hydroxymethylfurfural (HMF) is a versatile building block in numerous industrial applications. To date, few studies have described the production of its amine derivatives and their polymers. Finding a good methodology to directly transform HMF to5‐aminomethyl‐2‐furancarboxylic acid (AMFC) therefore represents an important challenge. After selecting the best oxidation catalyst for HMF conversion to5‐aldehyde‐2‐furancarboxylic acid and immobilizing a transaminase onto a solid carrier, we implemented the first one‐pot/two‐steps hybrid catalytic process to produce AMFC (77 % yield); this is the most efficient AMFC catalytic production method from HMF reported to date. This process also produced2,5‐furandicarboxylic acid (21 % yield) as a major secondary product that can be applied to polymer syntheses such as polyethylene furanoate. Herein, we report a novel way to access new biosourced polymers based on HMF oxidized and aminated derivatives.
Süßer Kälteschutz
Authors: Tetsch Larissa
Published: October 2020

Vor allem in Norddeutschland ziehen viele Menschen Grünkohl im eigenen Gemüsebeet. Sie schwören darauf, dass Kohl, der nach dem ersten Frost geerntet wird, süßer schmeckt. Tatsächlich schützen Grünkohlpflanzen ihre Zellen durch höhere Zuckerkonzentrationen vor schädlichen Eiskristallen.
Catalytic Property and Stability of Subnanometer Pt Cluster on Carbon Nanotube in Direct Propane Dehydrogenation
Authors: Sun Xiaoying , Xue Jiahui , Ren Yu , Li Xinyu , Zhou Lijing , Li Bo , Zhao Zhen
Published: October 2020

Main observation and conclusion

The stability of nanosized platinum catalyst in direct propane dehydrogenation reaction is one of most critical challenges, which hinders the further improvements of catalytic performance. The cokes from side reaction covering the active site seriously undermine the catalyst stability. In this work, first principles calculations are performed to explore the catalytic properties of supported subnanometer platinum cluster on carbon nanotube support and focus is put on the inhibition of deep dehydrogenation. The reactivities of metal, interface, and tin promoter are investigated at the same footing. The whole reaction pathway from propane adsorption to propene desorption is revealed for different sites. It turns out that the C—H bond activation in propane is not the catalytic step with the largest barrier. Instead, the desorption of propene is more difficult. The comparison between different sites indicates that the interface between metal and support and Sn promoter is helpful to curb the propene deep dehydrogenation. Moreover, a descriptor is proposed to screen the potential effective propane direct dehydrogenation catalyst. The current work provides important insights on the development of new dehydrogenation catalyst.
Awareness, knowledge and treatment decisions for erosive tooth wear: A case‐based questionnaire among Danish dentists
Authors: Mortensen Diana , Mulic Aida , Pallesen Ulla , Twetman Svante
Published: October 2020

Objective

To examine the knowledge and experience of erosive tooth wear (ETW) among Danish dental practitioners and, based on two cases, explore their treatment decisions.

Methods

We sent a validated questionnaire electronically to all active members of The Danish Dental Association and The Association of Public Health Dentists in Denmark. The questionnaire had two parts; the first focused on scoring, recordkeeping, knowledge and experience of ETW. The second part presented two patients with different severity of erosive lesions to explore the dentists preventive and restorative treatment decisions.

Results

We received 442 answers from 4,490 potentially eligible dentists in Denmark (response rate 9.8%). The majority (78%) was female and the median age was 44 years. Nearly all respondents (97%) registered ETW in the charts and 49% recorded “always” or “often” the patients' diet history, most commonly with aid of interviews. The respondents perceived the prevalence of ETW to be higher today than 10–15 years ago and male patients (15–25 years) appeared more affected than females. The majority (82%) thought that they usually found the probable cause of the condition with carbonated beverages being the most common factor. The treatment included dietary guidance, soft tooth brushing with non‐abrasive fluoride toothpaste, topical fluoride applications and direct composite restorations.

Conclusion

The majority of Danish dentists taking part of this survey had adopted a minimally invasive approach for the management of erosive tooth wear in young adults. There was however room for improvements in diagnosis, scoring and case documentation.
The intelligent multi‐domain service function chain deployment: Architecture, challenges and solutions
Authors: Zhang Chuangchuang , Wang Xingwei , Dong Anwei , Zhao Yong , Li Fuliang , Huang Min
Published: October 2020

Network function virtualization (NFV) technology achieves flexible service deployment by replacing the middleboxes with virtual network functions (VNFs). In NFV, a set of VNFs are chained in a given order, called service function chain (SFC), and accordingly, data flow is steered to traverse all the VNFs in order to offer a service. With a large number of network devices and end users being connected into Internet, there is a growing demand for large‐scale multi‐domain networks to dynamically deploy the SFC across multiple network domains, in order to support efficient service provisioning. To this end, in this paper, we first investigate the state of the art of multi‐domain SFC deployment, and then propose an intelligent multi‐domain SFC deployment (IMSD) architecture by leveraging software‐defined networking (SDN), NFV, and deep learning technologies. Furthermore, we discuss the potential challenges to realize the IMSD and provide some promising solutions.
Root cause analysis of indeterminate diagnoses in serous fluids cytopathology
Authors: Gokozan Hamza N. , Harbhajanka Aparna , Lyden Sandra , Michael Claire W.
Published: October 2020

Introduction

The International System for Reporting Serous Fluid Cytopathology proposed five diagnostic categories: Nondiagnostic (ND), Negative for Malignancy (NFM), Atypia of Undetermined Significance (AUS), Suspicious for Malignancy (SFM) and Malignant (MAL) (Primary or Metastatic). The indeterminate (AUS/SFM) categories are challenging for management. The goal of this study is to reveal the root causes contributing to indeterminate diagnoses (ID).

Materials and Methods

We searched our archives between 1 January 2017 and 30 June 2019, and performed a root cause analysis (RCA) using the “5 whys” method to determine the contributing factors of ID.

Results

Nine hundred eleven specimens were evaluated and diagnosed: ND (9, 1%), NFM (667, 73.2%), AUS (51, 5.6%), SFM (27, 3%) and MAL (157, 17.2%). More than one factor contributed to 38/78 ID. Low volume (<50 cc), and low cellularity were identified in 31 and 51 cases, respectively. Three cases were simply deferred to concurrent biopsy. Eleven cases were called atypical, favor reactive mesothelium despite confirmatory IHC. Atypical lymphoid population was reported in seven cases. Cellblocks (CB) were low in cellularity despite volume >1000 mL in 13 cases. Two mesotheliomas were underdiagnosed as suspicious.

Conclusions

Low cellularity and low volume were the most common contributing factors, highlighting the importance of adequate sample collection. Adequate volume specimens with low cellularity may benefit from a close inspection and a second CB. Some IDs can be switched to NFM or MAL with careful consideration of clinical, radiologic findings and ancillary testing, and concurrent surgical pathology correlation when available.
Targeted and passive environmental DNA approaches outperform established methods for detection of quagga mussels, Dreissena rostriformis bugensis in flowing water
Authors: Blackman Rosetta C. , Ling Kar Keun Sean , Harper Lynsey R. , Shum Peter , Hänfling Bernd , Lawson‐Handley Lori
Published: October 2020

The early detection of invasive non‐native species (INNS) is important for informing management actions. Established monitoring methods require the collection or observation of specimens, which is unlikely at the beginning of an invasion when densities are likely to be low. Environmental DNA (eDNA) analysis is a highly promising technique for the detection of INNS—particularly during the early stages of an invasion.

Here, we compared the use of traditional kick‐net sampling with two eDNA approaches (targeted detection using both conventional and quantitative PCR and passive detection via metabarcoding with conserved primers) for detection of quagga mussel, Dreissena rostriformis bugensis, a high priority INNS, along a density gradient on the River Wraysbury, UK.

All three molecular tools outperformed traditional sampling in terms of detection. Conventional PCR and qPCR both had 100% detection rate in all samples and outperformed metabarcoding when the target species was at low densities. Additionally, quagga mussel DNA copy number (qPCR) and relative read count (metabarcoding) were significantly influenced by both mussel density and distance from source population, with distance being the most significant predictor.

Synthesis and application. All three molecular approaches were more sensitive than traditional kick‐net sampling for the detection of the quagga mussel in flowing water, and both qPCR and metabarcoding enabled estimates of relative abundance. Targeted approaches were more sensitive than metabarcoding, but metabarcoding has the advantage of providing information on the wider community and consequently the impacts of INNS.
Flexible MoO2 Nanocrystals@N‐doped Carbon Nanofibers Film as a Self‐Supporting Anode for Quasi‐Solid‐State Sodium‐Ion Batteries
Authors: Wang Shichao , Liu Yang , Zhang Jinyang , Wang Yuyang , Hou Linrui , Yuan Changzhou
Published: October 2020

Herein, a bottom‐up electrospinning protocol is first developed to finely synthesize MoO2 nanocrystals@N‐doped carbon nanofibers (MoO2 NCs@N‐CNFs) film. The monodispersed MoO2 NCs of ≈2.1 nm in size are well confined in the 1D N‐CNFs. When evaluated as a self‐supporting anode for quasi‐solid‐state (QS) sodium‐ion batteries (SIBs) using the polyvinylidene fluoride hexafluoropropylene‐based Na+‐conducting gel electrolyte, the resultant MoO2 NCs@N‐CNFs exhibit remarkable Na+ storage behaviors in terms of reversible capacities and high‐rate cycling capabilities, benefiting from its synergistically structural and componential merits. More significantly, the contribution herein offers a simple yet efficient method to synthesize advanced hybrid anodes for QS SIBs.
Long‐term arsenic exposure impairs differentiation in mouse embryonal stem cells
Authors: McMichael Benjamin D. , Perego M. Chiara , Darling Caitlin L. , Perry Rebekah L. , Coleman Sarah C. , Bain Lisa J.
Published: October 2020

Arsenic is a contaminant found in many foods and drinking water. Exposure to arsenic during development can cause improper neuronal progenitor cell development, differentiation, and function, while in vitro studies have determined that acute arsenic exposure to stem and progenitor cells reduced their ability to differentiate. In the current study, P19 mouse embryonal stem cells were exposed continuously to 0.1‐μM (7.5 ppb) arsenic for 32 weeks. A cell lineage array examining messenger RNA (mRNA) changes after 8 and 32 weeks of exposure showed that genes involved in pluripotency were increased, whereas those involved in differentiation were reduced. Therefore, temporal changes of select pluripotency and neuronal differentiation markers throughout the 32‐week chronic arsenic exposure were investigated. Sox2 and Oct4 mRNA expression were increased by 1.9‐ to 2.5‐fold in the arsenic‐exposed cells, beginning at Week 12. Sox2 protein expression was similarly increased starting at Week 16 and remained elevated by 1.5‐fold to sixfold. One target of Sox2 is N‐cadherin, whose expression is a hallmark of epithelial–mesenchymal transitions (EMTs). Exposure to arsenic significantly increased N‐cadherin protein levels beginning at Week 20, concurrent with increased grouping of N‐cadherin positive cells at the perimeter of the embryoid body. Expression of Zeb1, which helps increase the expression of Sox2, was also increased started at Week 16. In contrast, Gdf3 mRNA expression was reduced by 3.4‐ to 7.2‐fold beginning at Week 16, and expression of its target protein, phospho‐Smad2/3, was also reduced. These results suggest that chronic, low‐level arsenic exposure may delay neuronal differentiation and maintain pluripotency.
Refined metadynamics through canonical sampling using time‐invariant bias potential: A study of polyalcohol dehydration in hot acidic solutions
Authors: Kondo Tomomi , Sasaki Takehiko , Ruiz‐Barragan Sergi , Ribas‐Ariño Jordi , Shiga Motoyuki
Published: October 2020

We propose a canonical sampling method to refine metadynamics simulations a posteriori, where the hills obtained from metadynamics are used as a time‐invariant bias potential. In this way, the statistical error in the computed reaction barriers is reduced by an efficient sampling of the collective variable space at the free energy level of interest. This simple approach could be useful particularly when two or more free energy barriers are to be compared among chemical reactions in different or competing conditions. The method was then applied to study the acid dependence of polyalcohol dehydration reactions in high‐temperature aqueous solutions. It was found that the reaction proceeds consistently via an SN2 mechanism, whereby the free energy of protonation of the hydroxyl group created as an intermediate is affected significantly by the acidic species. Although demonstration is shown for a specific problem, the computational method suggested herein could be generally used for simulations of complex reactions in the condensed phase.
A reduction of the spectrum problem for odd sun systems and the prime case
Authors: Buratti Marco , Pasotti Anita , Traetta Tommaso
Published: October 2020

A k‐cycle with a pendant edge attached to each vertex is called a k‐sun. The existence problem for k‐sun decompositions of Kv, with k odd, has been solved only when k = 3 or 5. By adapting a method used by Hoffmann, Lindner, and Rodger to reduce the spectrum problem for odd cycle systems of the complete graph, we show that if there is a ‐sun system of ( odd) whenever lies in the range and satisfies the obvious necessary conditions, then such a system exists for every admissible . Furthermore, we give a complete solution whenever k is an odd prime.
Expansion of human mesenchymal stem/stromal cells on temporary liquid microcarriers
Authors: Hanga Mariana P , Nienow Alvin W , Murasiewicz Halina , Pacek Andrzej W , Hewitt Christopher J , Coopman Karen
Published: October 2020

BACKGROUND

Traditional large‐scale culture systems for human mesenchymal stem/stromal cells (hMSCs) use solid microcarriers as attachment substrates. Although the use of such substrates is advantageous because of the high surface‐to‐volume ratio, cell harvest from the same substrates is a challenge as it requires enzymatic treatment, often combined with agitation. Here, we investigated a two‐phase system for expansion and non‐enzymatic recovery of hMSCs. Perfluorocarbon droplets were dispersed in a protein‐rich growth medium and were used as temporary liquid microcarriers for hMSC culture.

RESULTS

hMSCs successfully attached to these liquid microcarriers, exhibiting similar morphologies to those cultured on solid ones. Fold increases of 3.03 ± 0.98 (hMSC1) and 3.81 ± 0.29 (hMSC2) were achieved on day 9. However, the maximum expansion folds were recorded on day 4 (4.79 ± 0.47 (hMSC1) and 4.856 ± 0.7 (hMSC2)). This decrease was caused by cell aggregation upon reaching confluency due to the contraction of the interface between the two phases. Cell quality, as assessed by differentiation, cell surface marker expression and clonogenic ability, was retained post expansion on the liquid microcarriers. Cell harvesting was achieved non‐enzymatically in two steps: first by inducing droplet coalescence and then aspirating the interface. Quality characteristics of hMSCs continued to be retained even after inducing droplet coalescence.

CONCLUSION

The prospect of a temporary microcarrier that can be used to expand cells and then ‘disappear’ for cell release without using proteolytic enzymes is a very exciting one. Here, we have demonstrated that hMSCs can attach and proliferate on these perfluorocarbon liquid microcarriers while, very importantly, retaining their quality.
What are the factors that cause emergency home visit in home medical care in Japan?
Authors: Kuroda Kaku , Miura Taro , Kuroiwa Shota , Kuroda Moe , Kobayashi Naoko , Kita Keiichiro
Published: October 2020

Background

In the home medical care setting, the factors causing emergency home visits (EHV) remain unclear. This study aimed to determine those factors and examine their relationship with EHV requests.

Methods

This is a single‐center retrospective observational study from data obtained from a home medical care clinic. We assessed the association between frequency of EHV and age, gender, level of care‐needed, cancer, and medical device in use with using Poisson regression analysis.

Results

A total of 608 EHV in 214 patients were analyzed. Common chief complaints were fever, death, and dyspnea. As factors that affect frequency of EHV because of fever, higher care‐needed level (RR: 3.35; 95% CI: 1.95‐5.74, P < .001), urinary catheter use (RR: 1.94; 95% CI: 1.22‐3.08, P = .005), and central venous port use (RR: 2.39; 95% CI: 1.44‐3.96, P = .001) showed significant correlation. Regarding EHV because of dyspnea, lung tumor (RR: 2.71; 95% CI: 1.26‐5.84, P = .011) and home oxygen use (RR: 3.96; 95% CI: 2.05‐7.68, P < .001) showed significant correlation. Regarding EHV because of all chief complaints, higher care‐needed level (RR: 1.59; 95% CI: 1.12‐2.26, P = .009), urinary catheter use (RR: 1.78; 95% CI: 1.13‐2.93, P = .014), and central venous port use (RR: 1.75; 95% CI: 1.04‐2.93, P = .034) showed positive correlation.

Conclusion

The factors associated with frequency of EHV because of fever or all chief complaints were urinary catheter use, central venous port use, and higher care‐needed level. As for dyspnea, they were lung cancer and home oxygen use. Our study suggests that the burdens on medical staffs, patients, and their families can be reduced through recognizing these risk factors.
A single‐step synthesis of 1,3,4,6‐tetraaryl‐5‐aryliminopiperazin‐2‐one
Authors: El‐Araby Moustafa E. , Omar Abdelsattar M. E.
Published: October 2020

Chemical diversity is a strong driver in drug discovery, and chemical reactions that produce multi‐substituted heterocycles can result in significant chemical diversity. Here, we report a reaction that leads to highly substituted piperazinone derivatives in a single step. This was discovered accidently while reacting phenylglyoxal and anilines under Povarov conditions. We elucidated the structure of the compound formed when 2‐(4‐trifluoromethyphenyl)‐2‐oxoacetaldehyde was reacted with 4‐methoxyaniline as (1,4‐bis(4‐hydroxyphenyl)‐5‐[(4‐hydroxyphenyl)imino]‐3,6‐diphenylpiperazin‐2‐one) (5e). The structure was confirmed after extensive spectral analyses, including correlation spectroscopy, nuclear Overhauser effect spectroscopy, heteronuclear single quantum correlation spectroscopy, and heteronuclear multiple‐bond correlation nuclear magnetic resonance spectroscopy, in addition to high‐resolution mass spectrometry. This reaction is unprecedented and can potentially be exploited as a short route to highly diversified heterocycles.
The use of human biospecimens for research
Authors: Aaron Roy , Aaron David , Racine‐Avila Jennifer , Menikoff Jerry
Published: October 2020

This discussion presents many of the ethical, legal, and financial issues that underlie the contemporary regulatory framework for research with human biospecimens. Some considerations, such as claims of donor control over their biospecimens, could potentially constrain researchers’ freedom of action. We first consider concepts underlying consent to donate biospecimens for research. A requirement to obtain consent for donation of a biospecimen could conceptually be based upon the autonomy of the donor, or on property rights of the donor, or a combination of both concepts. If these concepts affect how consent is implemented, it could have significant downstream consequences for research and researchers. We present elements of the revision of the common rule that affect the use of human biospecimens including the current consent regulations based on transparency and autonomy, and the distinction between consent for, and ownership of, biospecimens. One of the major judicial opinions that denied property rights for biospecimens is described together with some implications for the research community of attributing ownership of biospecimens to their donors. We then consider transactional aspects of biospecimen donation. Considering biospecimens as a negotiable commodity presents both constraints and opportunities for donors and researchers. Compensation for biospecimens can be negotiated under contract law. Allowing donor control of the secondary research use of deidentified biospecimens could have an inhibiting effect on research. If donors possessed such control, even deidentification would not necessarily eliminate their ability to influence future research. Accordingly, new models of biospecimen donation are appearing in which the research community will have a substantial interest.
Health‐related quality of life and treatment modality among esophageal squamous cell carcinoma survivors: A prospective study using time to deterioration model analysis
Authors: Liu Shuang , Lin Zheng , Lin Jianbo , Chen Huilin , Xie Qianwen , Rao Wenqing , Chen Yuanmei , Yu Kaili , Hu Zhijian
Published: October 2020

Background and Objectives

This study aimed to analyze the association between health‐related quality of life and treatment modality among esophageal squamous cell carcinoma (ESCC) survivors.

Methods

Patients completed the EORTC QLQ‐C30 and EORTC QLQ‐OES18 at baseline and follow‐up. A time to deterioration model analysis was performed to compare longitudinal EORTC QLQ‐C30/QLQ‐OES18 data between surgery alone and surgery with adjuvant chemotherapy.

Results

For EORTC QLQ‐C30 scale, compared with surgery alone, significant delays in time to deterioration in role functioning (16.05 months vs. 15.00 months; p = .045), cognitive functioning (20.80 months vs. 16.26 months; p = .017), social functioning (19.09 months vs. 12.35 months; p = .001), and dyspnea (18.53 months vs. 14.62 months; p = .011) were observed for surgery with adjuvant chemotherapy. For QLQ‐OES18 scale, compared with surgery alone, significant delays in time to deterioration in dysphagia (13.75 months vs. 8.16 months; p = .005), choking when swallowing (20.67 months vs. 15.08 months; p = .001), and dry mouth (21.78 months vs. 17.28 months; p = .039) were observed for surgery with adjuvant chemotherapy.

Conclusions

Patients who received postoperative chemotherapy had significant delay in time to deterioration in multiple ESCC‐related symptoms, functions of EORTC QLQ‐C30 and EORTC QLQ‐OES18.
Surgical management of hepatocellular carcinoma patients with portal vein thrombosis: The United States Safety Net and Academic Center Collaborative Analysis
Authors: Ryon Emily L. , Kronenfeld Joshua P. , Lee Rachel M. , Yopp Adam , Wang Annie , Lee Ann Y. , Luu Sommer , Hsu Cary , Silberfein Eric , Russell Maria C. , Goel Neha , Merchant Nipun B. , Datta Jashodeep
Published: October 2020

Background

Although consensus guidelines generally discourage any surgical management (ASM; i.e., resection and/or transplantation) in patients with hepatocellular carcinoma (HCC) and portal vein thrombosis (PVT), recent series from Asia have challenged this paradigm.

Methods

Patients from the US Safety Net Collaborative database (2012–2014) with localized HCC and radiographically confirmed PVT were propensity‐score matched based on demographic and clinicopathologic factors associated with receipt of ASM and overall survival (OS). OS was compared between patients undergoing ASM and those not selected for surgery.

Results

Of 1910 HCC patients, 207 (14.5%) had localized disease and PVT. The majority received either liver‐directed therapies (LDTs; 34%) and/or targeted systemic therapies (36%). Twenty‐one patients (10.1%) underwent ASM (resection [n = 11], transplantation [n = 10]); a third experienced any complication with no 30‐day mortalities. Independent predictors of undergoing ASM were younger age, recent hepatology consultation, and lower model of end‐stage liver disease (MELD) score. After matching for age, comorbidities, MELD, tumor size, receipt of LDT, or systemic therapy, OS was significantly longer for patients selected for ASM versus non‐ASM patients (median not reached vs. 5.8 months, p < .001).

Conclusion

In a large North American multi‐institutional cohort, a minority of HCC patients with PVT were selected for ASM. Resection or transplantation was associated with improved survival and may have a role in the multimodality management in selected patients.
Comparison of Contrast‐Enhanced Ultrasound Versus Magnetic Resonance Imaging in the Detection and Characterization of Uterine Leiomyomas
Authors: Chhabra Pankaj , Daugherty Reza , LeNoir Ann Marie , Grilli Christopher , Makai Gretchen , Patel Nima , DeMauro Christopher
Published: October 2020

Objectives

Uterine fibroids are common findings in women with pelvic pain and abnormal uterine bleeding. The reference standard test in the pretreatment evaluation of fibroids is contrast‐enhanced magnetic resonance (MR) imaging. This study compared the number, size, location, and enhancement of uterine fibroids identified by contrast‐enhanced ultrasound (CEUS) and MR. The aim of this study was to demonstrate that CEUS performs similarly to MR and could be used as an alternative imaging modality.

Methods

In this prospective observational study, 26 women underwent transabdominal CEUS and MR examinations. Blinded to the original clinical MR interpretations, 2 readers reviewed the MR and CEUS studies for each patient. The number, size, location, and enhancement of each fibroid per patient were reported by MR and CEUS. A Pearson correlation coefficient was calculated for the number of fibroids identified by each modality.

Results

In total, 126 fibroids were imaged: 115 (91.3%) were observed on both examinations; 9 (7.1%) were observed by MR only; and 2 (1.6%) were observed by CEUS only. A high correlation was found between the modalities for the number of fibroids identified per patient (r = 0.97; P < .001). There was also no significant difference between the modalities for each patient in the fibroid number, size, location, or enhancement.

Conclusions

These findings suggest that transabdominal CEUS may represent an alternative to MR in pretreatment evaluation of uterine fibroids and could serve as a test of choice in patients with a contraindication to MR.
Tubed Supraglottic Laryngeal Closure to Treat Chronic Aspiration After Radiotherapy for Head and Neck Cancer
Authors: Ku Peter K. M. , Vlantis Alexander C. , Cho Ryan H. W. , Yeung Zenon W. C. , Ho Osan Y. M. , Hui Thomas S. C. , Abdullah Victor , van Hasselt Andrew , Tong Michael C. F.
Published: October 2020

Objectives/Hypothesis

To evaluate the long‐term swallowing outcomes after surgical treatment for chronic aspiration in patients treated with radiotherapy for head and neck cancer.

Study Design

This was a retrospective study.

Methods

The data of patients who underwent radiotherapy for head and neck cancer and who subsequently required a laryngectomy or a tubed supraglottic laryngeal closure (TSLC) for recurrent aspiration pneumonia between 2004 and 2017 were retrieved from a tertiary referral hospital dysphagia clinic. The Functional Oral Intake Scale (FOIS) and the Swallowing Performance and Status Scale (SPSS) were used to assess swallowing function.

Results

Of the 17 patients who required surgery for chronic aspiration secondary to radiotherapy for head and neck cancer, two underwent a laryngectomy and 15 a TSLC. During a mean follow‐up of 77 months, the FOIS and SPSS scores significantly improved at 12, 24, and 36 months after laryngectomy and TSLC relative to the baseline (P < .05). Both patients who underwent laryngectomy and 11 of the 15 (73.3%) who underwent a TSLC resumed oral feeding. Both laryngectomy patients had episodes of recurrent aspiration pneumonia after surgery due to leakage through the tracheoesophageal puncture or prosthesis, whereas none of the TSLC patients had these episodes.

Conclusion

A tubed supraglottic laryngeal closure, which is a reversible procedure that preserves the larynx and allows for natural phonation, should be considered an alternative to laryngectomy for the control of chronic aspiration.

Level of Evidence

4 Laryngoscope, 131:E1234–E1243, 2021
Biofeedback Training Improves Swallowing in a Unique Case of Upper Esophageal Sphincter Hypotonicity
Authors: Romain Dustin , Evans Lauran K. , Diaz Yvette , Allen Kathryn , Galek Kristine
Published: October 2020

Hypotonicity of the upper esophageal sphincter (UES) has been reported only two times previously in the literature, with no reports of treatment options for this rarity. We present a third case of hypotonic UES found during high‐resolution pharyngeal manometry. Although the patient had nearly absent resting pressures of the UES, pressures during and post‐swallow were normal. It was hypothesized that the patient might be able to increase pre‐swallow UES pressure using biofeedback. Using a chin up/out maneuver during manometry, the patient was able to achieve a more normal swallow pressure pattern. This case also highlights the need to complete manometry alongside other swallow imaging techniques for effective treatment planning and patient outcomes. Laryngoscope, 131:E1567–E1569, 2021
Agricultural development risks increasing gully erosion and cumulative sediment yields from headwater streams in Great Barrier Reef catchments
Authors: Shellberg Jeffrey G.
Published: October 2020

Protecting headwater streams is essential to minimise downstream sediment loads to rivers, estuaries, and oceans. This study analyses the gully and sheet erosion risk from a 33,000 ha agricultural development proposal in the Normanby catchment draining to the Great Barrier Reef (GBR) Lagoon, Australia. The slope‐area threshold for channel initiation was assessed for existing gully channel head locations using satellite images and a hydrologically enforced digital elevation model (SRTM). Thresholds were used to predict whether other stream lines (1:25k scale) were prone to gully incision under development. Results indicated that 430 km out of 1,200 km of streams were at risk of gullying, which could increase erosion by 2‐times, delivering 7,500 t yr−1locally and 1,700 t yr−1(worth A$1.8 million) to the GBR. Sheet erosion under agriculture is estimated (RUSLE) to increase by 13‐times from 0.12 to 1.5 t ha−1 yr−1, with 2,200 t yr−1to streams and 900 t yr−1(worth A$1 million) to the GBR. Buffering (±50 m) 560 km of headwater streams would cover 5,600 ha or 17% of the area. Precision agriculture using higher resolution topographic data (LiDAR) and improved slope‐area thresholds for gully erosion should be a minimum prerequisite for development, which would reduce but not eliminate increased sediment loads to the GBR. Forest clearance for agriculture is ongoing in Australia, but this first‐world country does not have effective policies or regulations to protect headwater streams or cumulative impacts to the World Heritage Great Barrier Reef, despite millions of dollars spent annually to reduce past land degradation.
Converting alfalfa pasture into annual cropland achieved high productivity and kept soil organic carbon in a semiarid area
Authors: Zhang Xu‐Long , Zhao Yang‐Yang , Gao Wen‐Juan , Song Xin , Zhang Xin‐Tan , Shi Xiao‐Yan , Li Feng‐Min
Published: October 2020

Converting alfalfa (Medicago sativa L.) into annual cropland (rotated cropland, RC) is commonly done to reuse degraded alfalfa pasture. However, it is a big challenge for RC to achieve high productivity and maintain high soil organic carbon (SOC) to the levels achieved by previous alfalfa pasture. We converted a long‐term alfalfa pasture into RC in 2010, and studied the effects of fertilization on soil moisture, crop productivity, and SOC in the RC and in continuous cropland (CC), both under plastic film mulching, from 2010 to 2018. Before the conversion, alfalfa pasture had a higher SOC (12.3%) and total N (7.7%) than CC. However, not only severe soil desiccation occurred, but the available P and inorganic‐N were only about 39.4 and 25.1% of levels for CC. After the conversion, soil moisture in RC (measured at 0–0.6 m depth) was up to CC levels only after 1 year, and was restored to 95.3 and 69.2% of CC levels at 0.6–2 and 2–5 m depths only after 9 years. Crop yield and biomass in RCF (RC with fertilization) were comparable to those for CCF (CC with fertilization) after two years from conversion due to the increased available P and inorganic‐N, and sufficient soil moisture restoration at 0–0.6 m depath. SOC in RC decreased by 8.1% over the 9 years, while RCF consistently kept SOC levels up to those of pre‐conversion alfalfa pasture. These findings help to eliminate concerns about the continuously low production and rapid decline of SOC in croplands converted from alfalfa and suggest ways to support sustainable high‐productivity and high SOC sequestration in dryland farming.