bluuebunny/crossref_metadata_2025 huggingface dataset:
Nickel‐Catalyzed Intramolecular Decarbonylative Coupling of Aryl Selenol Esters
Authors: Bai Jin‐Hua , Qi Xiu‐Juan , Sun Wei , Yu Tian‐Yang , Xu Peng‐Fei
Published: February 2021

This report describes a method for Ni‐catalyzed intramolecular decarbonylative coupling, which enables the conversion of areneselenol esters to diaryl selenides. The inexpensive and readily available catalyst can be employed under mild reaction conditions for the construction of structurally diverse diaryl selenides, including heterocyclic and natural product derivatives.

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Towards Photoswitchable Contrast Agents for Absolute 3D Temperature MR Imaging
Authors: Wellm Vanessa , Groebner Jens , Heitmann Gernot , Sönnichsen Frank D. , Herges Rainer
Published: February 2021

Temperature can be used as clinical marker for tissue metabolism and the detection of inflammations or tumors. The use of magnetic resonance imaging (MRI) for monitoring physiological parameters like the temperature noninvasively is steadily increasing. In this study, we present a proof‐of‐principle study of MRI contrast agents (CA) for absolute and concentration independent temperature imaging. These CAs are based on azoimidazole substituted NiII porphyrins, which can undergo Light‐Driven Coordination‐Induced Spin State Switching (LD‐CISSS) in solution. Monitoring the fast first order kinetic of back isomerisation (cis to trans) with standard clinical MR imaging sequences allows the determination of half‐lives, that can be directly translated into absolute temperatures. Different temperature responsive CAs were successfully tested as prototypes in methanol‐based gels and created temperature maps of gradient phantoms with high spatial resolution (0.13×0.13×1.1 mm) and low temperature errors (<0.22 °C). The method is sufficiently fast to record the temperature flow from a heat source as a film.
S‐Carboxyanhydrides: Ultrafast and Selective Ring‐Opening Polymerizations Towards Well‐defined Functionalized Polythioesters
Authors: Wang Yanchao , Li Maosheng , Wang Shixue , Tao Youhua , Wang Xianhong
Published: February 2021

Aliphatic polythioesters are popular polymers because of their appealing performance such as metal coordination ability, high refractive indices, and biodegradability. One of the most powerful approaches for generating these polymers is the ring‐opening polymerization (ROP) of cyclic monomers. However, the synthesis of precisely controlled polythioesters via ROP of thiolactones still faces formidable challenges, including the minimal functional diversity of available thiolactone monomers, as well as inevitable transthioesterification side reactions. Here we introduce a hyperactive class of S‐carboxyanhydride (SCA) monomers derived from amino acids that are significantly more reactive than thiolactones for ultrafast and selective ROP. Inclusion of the initiator PPNOBz ([PPN]=bis(triphenylphosphine)‐iminium) with chain transfer agent benzoic acid, the polymerizations that can be operated in open vessels reach complete conversion within minutes (1–2 min) at room temperature, yielding polythioesters with predictable molecular weight, low dispersities, retained stereoregularity and chemical recyclability. Most fascinating are the functionalized SCAs that allow the incorporating of functional groups along the polythioester chain and thus finely tune their physicochemical performance. Computational studies were carried out to explore the origins of the distinctive rapidity and exquisite selectivity of the polymerizations, offering mechanistic insight and explaining why high polymerizability of SCA monomer is able to facilitate exquisitely selective ring‐opening for enchainment over competing transthioesterification and backbiting reactions.
An Integrated Design of a Polypseudorotaxane‐Based Sea Cucumber Mimic
Authors: Li Longyu , Lin Qianming , Tang Miao , Tsai Esther H. R. , Ke Chenfeng
Published: February 2021

The development of integrated systems that mimic the multi‐stage stiffness change of marine animals such as the sea cucumber requires the design of molecularly tailored structures. Herein, we used an integrated biomimicry design to fabricate a sea cucumber mimic using sidechain polypseudorotaxanes with tunable nano‐to‐macroscale properties. A series of polyethylene glycol (PEG)‐based sidechain copolymers were synthesized to form sidechain polypseudorotaxanes with α‐cyclodextrins (α‐CDs). By tailoring the copolymers’ molecular weights and their PEG grafting densities, we rationally tuned the sizes of the formed polypseudorotaxanes crystalline domain and the physical crosslinking density of the hydrogels, which facilitated 3D printing and the mechanical adaptability to these hydrogels. After 3D printing and photo‐crosslinking, the obtained hydrogels exhibited large tensile strain and broad elastic‐to‐plastic variations upon α‐CD (de)threading. These discoveries enabled a successful fabrication of a sea cucumber mimic, demonstrating multi‐stage stiffness changes.
Consecutive β,β′‐Selective C(sp3)−H Silylation of Tertiary Amines with Dihydrosilanes Catalyzed by B(C6F5)3
Authors: Fang Huaquan , Xie Kaixue , Kemper Sebastian , Oestreich Martin
Published: February 2021

Tris(pentafluorophenyl)borane has been found to catalyze the two‐fold C(sp3)−H silylation of various trialkylamine derivatives with dihydrosilanes, furnishing the corresponding 4‐silapiperidines in decent yields. The multi‐step reaction cascade involves amine‐to‐enamine dehydrogenation at two alkyl residues and two electrophilic silylation reactions of those enamines, one inter‐ and one intramolecular.
Optic neuritis after ocular trauma in anti‐aquaporin‐4 antibody‐positive neuromyelitis optica spectrum disorder
Authors: Akaishi Tetsuya , Himori Noriko , Takeshita Takayuki , Fujihara Kazuo , Misu Tatsuro , Takahashi Toshiyuki , Fujimori Juichi , Ishii Tadashi , Aoki Masashi , Nakazawa Toru , Nakashima Ichiro
Published: February 2021

Objective

The aim of this study was to report the possible association between minor trauma to the eyes and the subsequent occurrence of optic neuritis in patients with serum anti‐aquaporin‐4 (AQP4) antibody‐positive neuromyelitis optica spectrum disorder (NMOSD).

Methods

Herein, we present three patients who developed acute optic neuritis with visual disturbances after accidental minor trauma to their eyes, without any fundus abnormality or orbital floor fractures present.

Results

Two of the three patients had a preceding history of neurological disturbances compatible with NMOSD (e.g., myelitis, area postrema syndrome) before the occurrence of trauma. One patient was rapidly treated with steroid pulse therapy and plasmapheresis, and he fully recovered visual acuity. The other two, who were left untreated in the acute phase, had sequelae of severe visual disturbances in the affected eyes.

Conclusions

These cases suggest possible association between minor trauma to the eyes and the subsequent occurrence of optic neuritis in patients with serum anti‐AQP4 antibodies. Avoiding ocular trauma and early administration of steroid pulse therapy in response to optic neuritis after trauma are desired in such cases.
The value of fragmented QRS in predicting the prognosis of chronic total occlusion patients with myocardial infarction history undergoing percutaneous coronary intervention: A 24‐months follow‐up study
Authors: Yang Tiangui , Fu Xi , Fu Peng , Chen Jie , Xu Changlu , Liu Xiaoxia , Niu Tiesheng
Published: February 2021

Background

Fragmented QRS (fQRS) is a marker of local myocardial scar. This study aimed to analyze the relationship between fQRS and coronary collateral circulation (CCC) and evaluate the predictive value of fQRS for long‐term clinical outcomes among patients with chronic total occlusion (CTO) and prior myocardial infarction (MI) who underwent percutaneous coronary intervention (PCI).

Methods

A total of 862 patients with a definite history of MI who had one CTO coronary artery and underwent PCI between 2013 and 2018 were continuously analyzed. Patients were divided into group A (no Q wave and fQRS, n = 206), group B (fQRS, n = 265), group C (Q wave, n = 391). All patients were followed up for 2 years.

Results

The incidence rate of major adverse cardiovascular events (MACE) in group B was significantly lower than in group C (group B vs. C: 7.2% vs. 11.3%, P = 0.043). The percentage of good CCC was 94.2%, 88.3%, and 82.9% in group A, B, and C (p < .001), respectively. The improvement of cardiac function in group B and A were more significant than in group C. Multivariate Cox regression analysis showed fQRS was an independent protective factor of MACE after PCI within 2 years in CTO patients with prior MI (RR = 0.668, 95% CI [0.422–0.917], p = .001).

Conclusion

fQRS is an independent protective factor of prognosis in patients with prior MI and one CTO vessel who underwent PCI, presenting with a higher rate of good CCC, less occurrence of MACE, and better heart function than in Q wave patients.
Enhanced Nanostructure Dynamics on Au(111) with Adsorbed Sulfur due to Au−S Complex Formation
Authors: Spurgeon Peter M. , Liu Da‐Jiang , Windus Theresa L. , Evans James W. , Thiel Patricia A.
Published: February 2021

The front cover artwork is provided by Dr. Peter Spurgeon, Dr. Da‐Jiang Liu, and Prof. Jim Evans at Ames Laboratory USDOE and Iowa State University. The top images show the decay of a 2D Au island on Au(111) in the presence of 24 milli‐monolayers of S. The enhancement of island decay with increasing S coverage is quantified in the lower left image for ∼85 nm2 Au islands. The Au‐S complexes implicated as facile mass carriers enhancing decay are also illustrated. Read the full text of the Article at 10.1002/cphc.202000884.
Metacognitive beliefs across eating disorders and eating behaviours: A systematic review
Authors: Palmieri Sara , Mansueto Giovanni , Ruggiero Giovanni Maria , Caselli Gabriele , Sassaroli Sandra , Spada Marcantonio M.
Published: February 2021

Background

Literature has pointed out a probable association between metacognitive beliefs and eating disorders. To date, no study has synthetized all research exploring the differences or similarities in metacognitive beliefs across different eating disorders diagnoses and eating problems.

Aims

To review the evidence on metacognitive beliefs across the spectrum of eating disorders and eating behaviours.

Method

A comprehensive search was conducted on PubMed and PsycInfo. The search terms used were: ‘eating disorders/anorexia/bulimia/binge eating disorder/binge eating’ AND ‘metacognitions/metacognitive beliefs’. A manual search of reference lists was also run.

Results

Eleven studies were identified. Anorexia Nervosa was broadly characterized by higher levels of metacognitive beliefs compared to the general population, particularly negative beliefs about worry and beliefs about the need to control thoughts. Positive beliefs about worry were higher in Anorexia Nervosa compared to Bulimia Nervosa and Eating Disorder Not Otherwise Specified, and in Bulimia Nervosa compared to Eating Disorder Not Otherwise Specified. Negative beliefs about worry were higher in Anorexia Nervosa compared to Bulimia Nervosa. Cognitive self‐consciousness was higher in Anorexia Nervosa compared to Bulimia Nervosa and Eating Disorder Not Otherwise Specified.

Conclusions

Metacognitive beliefs appear to be implicated in eating disorders and eating behaviours.
Predicting change through individual symptoms and relationship distress: A study of within‐ and between‐person processes in couple therapy
Authors: Tilden Terje , Ulvenes Pål , Zahl‐Olsen Rune , Hoffart Asle , Johnson Sverre Urnes , Wampold Bruce E. , Håland Åshild Tellefsen
Published: February 2021

Objective

In couple therapy clients often suffer from a blend of individual psychiatric symptoms as well as severe relational distress. However, research is inconclusive on whether relational change predicts symptom change or vice versa. Because answers to this question could have important clinical implications on what to focus on in couple therapy at which time in treatment, more research is recommended.

Method

In this study, data collected before every therapy session were used to test whether changes in relational functioning predicted symptom functioning or vice versa. The study used a multilevel modelling approach, and the variables of interest were disaggregated into within‐ and between‐person effects.

Results

The results indicated that if an individual improved more than expected on relational functioning, this predicted more improvement than expected on individual symptoms. No significant reciprocal relationship was found between these variables.

Conclusions

The clinical implication is discussed, suggesting that an emphasis on relational improvement seems to be an important mechanism during couple therapy that may facilitate the change on individual symptoms in the long run.
‘Someone on my level’: A Meta‐Ethnographic Review of Therapeutic Relationships in Cognitive Behavioural Therapy for Psychosis
Authors: Pipkin Alastair , Hogg Lorna , Armitage Sarah
Published: February 2021

Objectives

Cognitive Behavioural Therapy for Psychosis (CBTp) demonstrates variable and at times mild to moderate effect sizes; thus, its therapeutic processes are important to explore. Establishing a secure therapeutic relationship is one such key process where barriers may exist, including those related to psychotic symptoms and associated stigma. This review synthesizes the available qualitative research pertaining to the experience of the therapeutic relationship from the perspective of those experiencing psychosis.

Methods

A systematic review was undertaken using PRISMA guidelines. Search terms included variants of ‘psychosis’, ‘therapy’ and ‘qualitative’. PsycInfo, CINAHL, EmBase, MedLine and Web of Science were searched, and reference lists were hand‐scanned. Yardley's quality appraisal tool was utilized and Noblit and Hare's seven‐stage process for conducting a meta‐ethnographic review. A line‐of‐argument synthesis is presented.

Results

Fourteen papers were identified using inclusion and exclusion criteria. Twelve papers were deemed to have satisfactory quality. The line‐of‐argument synthesis used attachment theory to propose four semi‐distinct stages to establishing a therapeutic relationship: beginning; safety, hope and trust; the practicalities of therapy; and branching out. Findings suggest that the therapist's persona and use of CBTp techniques such as collaboration and shared agency over the process were important in establishing for the patient a sense of self as normal, equal and worthwhile.

Conclusions

Attachment security may be an important strand of CBTp and warrants further research and clinical investigation as a process and an outcome. Future research can benefit from increased transparency regarding researcher positionality as a potential source of bias.
Winter cereal responses to dose and application timing of trinexapac‐ethyl
Authors: Subedi Maya , Karimi Rezvan , Wang Zhijie , Graf Robert J. , Mohr Ramona M. , O'Donovan J. T. , Brandt Stu , Beres Brian. L.
Published: February 2021

Trinexapac‐ethyl (TE) is a plant growth regulator commonly used in cereal production systems. It retards plant growth by inhibiting gibberellin (GA) biosynthesis, thereby reducing the risk of stem lodging. Lodging at the latter stages of crop development can compromise grain yield and quality. Thus, application of TE may protect yield and quality in winter cereals. A field study was conducted from 2014 to 2017 across the Canadian Prairies to determine the effects of TE dose and application timings on lodging, canopy architecture, grain yield, and quality of winter cereals. Trinexapac‐ethyl treatments consisted of 0.6× (60 g a.i. ha−1) and 1× (100 g a.i. ha−1), which were applied to two winter wheat (Triticum aestivum L.) cultivars, 'Flourish’ and ‘Moats’, and a fall rye (Secale cereale L.) cultivar ‘Hazlet’, at Feekes 5 and 7 growth stages. Compared with the control, TE application increased grain yield by 3–8%, reduced plant height by 5–10%, and shortened internode length. Plant height reductions were most notable when TE was applied at the 1× rate at Feekes 7. The most responsive crop was fall rye, which could be expected given its tall stature relative to the wheat cultivars. Most of the tested environments, including irrigation, did not induce heavy stem lodging; therefore, observations of positive yield responses in the absence of lodging were unexpected. Our findings suggest that there is a role for TE in winter cereal production systems, provided the magnitude of crop responses justifies the added input costs.
Student communities contribute to necessary cultural change in the health sciences
Authors: Jain Neera R.
Published: February 2021

Research tells us that students with disabilities remain marginalized in health science education. Students report that their disabilities are often perceived as liabilities rather than professional assets. While improving access to and reach of accommodations in these programs is critical, this is just one aspect of a larger system in need of change. One route toward more‐positive educational spaces where students can flourish with disabilities is to support student disability communities on health science campuses.
COVID‐19 is the only issue that will matter in 2021
Authors: Hodges Dawn Z.
Published: February 2021

For 2021, there's only one issue that will matter for higher education: COVID‐19. The pandemic is impacting every aspect of higher education, including technology, curriculum, learning, grades, COVID‐19 testing, campus safety, mental health, enrollment, mergers, closures, layoffs, and fundraising.
The effects of population synchrony, life history, and access constraints on benefits from fishing portfolios
Authors: Oken Kiva L. , Holland Daniel S. , PUNT ANDRÉ E.
Published: February 2021

Natural resources often exhibit large interannual fluctuations in productivity driven by shifting environmental conditions, and this translates to high variability in the revenue resource users earn. However, users can dampen this variability by harvesting a portfolio of resources. In the context of fisheries, this means targeting multiple populations, though the ability to actually build diverse fishing portfolios is often constrained by the costs and availability of fishing permits. These constraints are generally intended to prevent overcapitalization of the fleet and ensure populations are fished sustainably. As linked human‐natural systems, both ecological and fishing dynamics influence the specific advantages and disadvantages of increasing the diversity of fishing portfolios. Specifically, a portfolio of synchronous populations with similar responses to environmental drivers should reduce revenue variability less than a portfolio of asynchronous populations with opposite responses. We built a bioeconomic model based on the Dungeness crab (Metacarcinus magister), Chinook salmon (Oncorhynchus tshawytscha), and groundfish fisheries in the California Current, and used it to explore the influence of population synchrony and permit access on income patterns. As expected, synchronous populations reduced revenue variability less than asynchronous populations, but only for portfolios including crab and salmon. Synchrony with the longer‐lived groundfish population was not important because environmentally driven changes in groundfish recruitment were mediated by growth and natural mortality over the full population age structure, and overall biomass was relatively stable across years. Thus, building a portfolio of diverse life histories can buffer against the impacts of poor environmental conditions over short time scales. Increasing access to all permits generally led to increased revenue stability and decreased inequality of the fleet, but also resulted in less revenue earned by an individual from a given portfolio because more vessels shared the available biomass. This means managers are faced with a trade‐off between the average revenue individuals earn and the risk those individuals accept. These results illustrate the importance of considering connections between social and ecological dynamics when evaluating management options that constrain or facilitate fishers’ ability to diversify their fishing.
A Concise Stereoselective Total Synthesis of Methoxyl Citreochlorols and Their Structural Revisions
Authors: Sunnapu Ranganayakulu , Rajendar Goreti
Published: February 2021

A concise, stereoselective and protecting group free approaches for the total synthesis of (−)‐(2S,4R)‐ and (+)‐(2R,4S)‐3′‐methoxyl citreochlorols and their stereoisomers are demonstrated. All four stereoisomers were synthesized to establish the absolute stereochemistry of the reported structures and the structures were revised accordingly. The approach involves chelation controlled regioselective reduction of a diester, silyl iodide promoted ring‐opening iodo esterification of lactones, highly chemo‐ and regioselective ring‐opening of an epoxy ester, dichloromethylation of a carboxyl group, and syn‐ and anti‐selective reduction of the resulted β‐hydroxy ketone as key steps.
Intramolecular Heck Reaction in Total Synthesis of Natural Products: An Update
Authors: Paul Debobrata , Das Subhendu , Saha Sanu , Sharma Himangshu , Goswami Rajib Kumar
Published: February 2021

This review highlights the application of intramolecular Heck reaction in total synthesis of natural products which were successfully synthesized in recent years (2013 to 2019). Heck cyclization was used as one of the strategic steps for constructions of wide variety of cyclic scaffolds essential for preparation of different natural products.
The Winding Road towards an Atropo‐enantioselective ‘ARYNE Coupling’
Authors: Augros David , Comoy Corinne , Fort Yves , Leroux Frédéric R. , Panossian Armen
Published: February 2021

For the first time, the challenging atropo‐enantioselective coupling of in‐situ generated arynes and aryllithiums in the presence of a chiral ligand of lithium was investigated. This preliminary study demonstrates the feasibility of this concept, by affording enantioenriched axially chiral biaryls even in the case of products showing a high degree of steric congestion around the newly created aryl−aryl bond.
Structure, Content and Inter‐relationships between Self‐aspects: Integrating Findings from the Social Identity and Self Complexity Traditions
Authors: Banas Kasia , Smyth Lillian
Published: February 2021

The “social cure” literature from the social identity approach, and the self‐complexity literature are both concerned with the structure and content of the self, and their relationship to wellbeing. Our work seeks to integrate these two approaches by investigating the exact characteristics of the self‐concept that are associated with wellbeing, focusing in particular on self‐aspects that are supportive, positive, representative and compatible (“superaspects”). In a pre‐registered correlational study (n = 640) we found that the number of collective superaspects was positively associated with affect balance and quality of life (H1a), but the number of non‐collective superaspects was positively associated only with affect balance (H1b). We found no evidence that similarity between self‐aspects was negatively associated with wellbeing (H2), or that a self‐reported measure of positivity was more strongly associated with wellbeing than a calculated measure (H3). These findings suggest potential avenues for an integrated measurement of the self‐concept and its association with wellbeing.
Effective communication now more critical than ever
Authors: Enos Gary A.
Published: February 2021

As an undergraduate math major, Tyler Hayes envisioned a career in K–12 teaching. However, his experiences in college opened his eyes to the life‐changing effect higher education can have on young people and their families.
In Situ‐Grown Nitrogen‐Doped Carbon‐Nanotube‐Embedded Two Phases of Bimetal CoFe Alloy and CoFe2O4 Spinel Oxide as Highly Efficient Bifunctional Catalyst for Oxygen Reduction and Evolution Reactions in Rechargeable Zinc–Air Batteries
Authors: Kone Issa , Ahmad Zubair , Xie Ao , Kong Lingpo , Tang Yang , Sun Yanzhi , Chen Yongmei , Yang Xiaojin , Wan Pingyu
Published: February 2021

The pedestal of the rechargeable zinc–air battery (ZAB) is based on high‐performance bifunctional oxygen reduction/evolution reactions (ORR/OER) electrocatalysts. Herein, without any template or surfactant, in situ grown nitrogen‐doped carbon‐nanotube (NCNT)‐embedded with two phases of bimetal CoFe alloys and CoFe2O4 spinel oxide are constructed, using inexpensive materials of glucose, urea, and cobalt/iron acetates by programing the pyrolysis temperature. The obtained catalyst with optimal cobalt/iron acetates mass ratio (1:1) denoted as CoFe–CoFe2O4–NCNT not only exceeds Pt–Ru/C in terms of ORR half‐wave potentials [(0.88 vs 0.84 V versus reversible hydrogen electrode (RHE)] and limiting current densities (6.40 vs 5.40 mA cm−2), but also manifests superior OER activity with the potentials of (1.58 vs 1.67 V versus RHE) at 10 mA cm−2. Therefore, CoFe–CoFe2O4–NCNT exhibits a smaller value of (0.70 V versus RHE), surpassing that of Pt–Ru/C (0.85 V versus RHE) and shows excellent stability as well as outstanding methanol tolerance compared with the Pt–Ru/C commercial catalyst. In addition, CoFe–CoFe2O4–NCNT applied as a bifunctional air electrode in rechargeable ZAB displays a promising rechargeability performance with high‐discharge and low‐charge potentials and a relatively stable potential gap under 550 cycles, outperforming those of Pt–Ru/C.
In vitro bioaccessibility of macular xanthophylls from commercial microalgal powders of Arthrospira platensis and Chlorella pyrenoidosa
Authors: Tudor Cristina , Gherasim Elena Cristina , Dulf Francisc Vasile , Pintea Adela
Published: February 2021

The bioaccessibility of the major carotenoids present in two commercial microalgal supplements in powder form was investigated through a standardized in vitro digestion method. The dried biomass of Arthrospira platensis contained β‐carotene (36.8 mg/100 g) and zeaxanthin (20.8 mg/100 g) as the main carotenoids as well as a high content of saturated fatty acids (61% of total fatty acids), whereas that of Chlorella pyrenoidosa was rich in lutein (37.8 mg/100 g) and had a high level of unsaturated fatty acids (65% of total fatty acids). In the case of the latter, lutein bioaccessibility was not statistically enhanced after the replacement of porcine bile extract with bovine bile extract in the in vitro digestion protocol and after the addition of coconut oil (17.8% as against to 19.2% and 19.2% vs. 18.5%, respectively). In contrast, the use of bovine bile extract along with co‐digestion with coconut oil significantly enhanced the bioaccessibility of zeaxanthin from A. platensis, reaching the highest bioaccessibility of 42.8%.
A computational study of the reaction mechanism involved in the fast cleavage of an unconstrained amide bond assisted by an amine intramolecular nucleophilic attack
Authors: Cuesta Sebastián Adolfo , Rincón Luis , Torres F. Javier , Rodríguez Vladimir , Mora José Ramón
Published: February 2021

In the present work, the fast amide bond cleavage of [3‐((1R,5S,7s)‐3‐azabicyclo[3.3.1]nonane‐7‐carbonyl)‐3‐azabicyclo[3.3.1]nonane‐7‐carboxylic acid (bi‐ATDO)], through an intramolecular nucleophilic attack of an amine group is evaluated. First, six possible peptide bond cleavage mechanisms, two of them including a water molecule, are described at the ωB97XD/6–311 + G(d,p)//MP2/6–311 + G(d,p) level of theory. The reaction consisting of an intramolecular nitrogen nucleophilic attack followed by a proton transfer and the amide bond cleavage is determined as the most favorable mechanism. The activation free energy computed for the latter is 20.5 kcal mol−1, which agrees with the reported experimental result of 24.8 kcal mol−1. Inclusion of a water molecule to assist the first step of the reaction results in an activation free energy increase of about 17 kcal mol−1. All the steps in the most favorable mechanism are studied more in detail employing intrinsic reaction coordinate as well as the reaction force and reaction electronic flux analysis.
Toward an understanding of regulatory T cells in COVID‐19: A systematic review
Authors: Rahimzadeh Mahsa , Naderi Nadereh
Published: February 2021

A more detailed understanding of Treg cells in COVID‐19 infection will broaden our knowledge of the COVID‐19 immunopathology and give us more insight into the curative immune‐based strategies. We systematically searched electronic databases (PubMed, Google Scholar, EMBASE) and identified 18 eligible studies. Despite the inconsistencies between the results, we observed a trend toward decreasing Treg levels in severe COVID‐19 patients. This finding underlines the hypothesis that Tregs play a role in the pathogenesis of COVID‐19. Further studies on Tregs' functional aspects are necessary to illustrate Tregs' potential role in COVID‐19 disease.
Investigation of genetic variation: Neuraminidase gene of influenza A virus H1N1/pdm09, Shiraz, Iran (2015–2016)
Authors: Rashidi Omid , Moattari Afagh , Pirbonyeh Neda , Emami Amir , Kadivar Mohammad Rahim , Tavakoli Movaghar Nahid , Edalat Fahimeh
Published: February 2021

Oseltamivir and antiviral agents are frequently used for the prevention and treatment of influenza infection. However, resistance to oseltamivir has been reported globally due to a mutation in the Influenza virus neuraminidase gene. Such resistance will be detected by genotyping and phenotyping studies of viral isolates. The recent study aimed to determine the genetic mutation of neuraminidase gene in influenza A (H1N1) viruses isolated from children referred to Shiraz tertiary hospitals during 1 year (2015–2016) with influenza‐like symptoms. A total of 300 patients were registered and throat samples were taken. The throat swabs were used for viral RNA extraction. Detection of influenza A (H1N1) was performed using the one‐step real‐time polymerase chain reaction (qRT‐PCR) method. From positive isolates for H1N1, 51 random samples were evaluated for neuraminidase gene mutation with the nested PCR‐sequencing method. Of 300 cases, 102 (34%) isolates were detected as influenza A (H1N1) pdm09. Based on sequencing results, 2 of the 44 sequenced isolates exhibited H275Y substitution, which presented oseltamivir resistance. In comparison with reference strain, the phylogenetic analysis of sequenced isolates was classified in genogroup 6B. While this result is the first report of emerging oseltamivir‐resistant in the southwest of Iran, it is highly recommended to perform these evaluations on the different geographical regions in any prevalence area to plan treatment strategies for influenza.
A thin‐layer solid‐phase extraction–liquid film elution technique used for the enrichment of polycyclic aromatic hydrocarbons in water
Authors: Nukatsuka Isoshi , Satoh Ryota , Kihara Shigeki , Kitagawa Fumihiko
Published: February 2021

In this article, we propose a novel microsolid‐phase extraction and elution technique, which we called the thin‐layer solid‐phase extraction–liquid film elution technique. The thin‐layer solid‐phase extraction phase is an octadecylsilylated sol gel‐ coated porous silica thin film prepared on the outer wall of a test tube, which has a larger surface area for the extraction of the target compounds compared to a conventional solid‐phase microextraction phase. After optimization of the extraction procedure for five types of polycyclic aromatic hydrocarbons, the liquid film elution technique was investigated. Liquid film elution is an elution technique wherein the compounds extracted into the thin‐layer solid‐phase extraction phase are eluted using a small volume of solvent film formed around the extraction phase. The results show that the elution can be carried out using 150 μL of eluent. Enrichment factors between 20 and 34 were obtained for polycyclic aromatic hydrocarbons containing more than four aromatic rings in 10 mL aliquots of aqueous samples. Finally, recoveries of 85‐112% were obtained for polycyclic aromatic hydrocarbons containing more than four aromatic rings from spiked natural water samples using the thin‐layer solid‐phase extraction–liquid film elution technique.
Determination of phenols in natural and waste waters by capillary electrophoresis after preconcentration on magnetic nanoparticles coated with aminated hypercrosslinked polystyrene
Authors: Gubin Alexander , Sukhanov Pavel , Kushnir Aleksei , Sannikova Natalia , Konopleva Victoria , Nikulina Alla
Published: February 2021

An efficient sorbent for magnetic solid‐phase extraction was developed from Fe3O4 nanoparticles covered with aminated hypercrosslinked polystyrene. The sorbent has a saturation magnetization of 47 emu/g and a surface area of 509 mg/g and was tested for the extraction of 11 phenols from aqueous media. The optimum conditions were as follows: pH 3; adsorbent mass, 20.0 mg; adsorption time, 30 min; eluent (acetone) volume, 0.5 mL; and desorption time, 5 min. The enrichment factor after desorption reached 1595‐1716 and the maximum adsorption capacity was 501‐909 mg/g. Capillary electrophoresis was applied successively to separate 11 phenols after solid‐phase extraction. The best separation was achieved using a fused silica capillary and borate buffer (pH 10.7) as a supporting electrolyte. After optimization, the linearity range was from 0.2 to 950 μg/L, and the limits of detection were 0.05‐0.2 μg/L. The relative standard deviation varied from 6.1 to 8.7% (C = 1 μg/L) and from 2.9 to 3.5% (C = 500 μg/L). The determination of phenols is complicated in eutrophic water and spring water with a high content of humic and fulvic acids.
Contemporary Incremental Healthcare Costs for Chronic Rhinosinusitis in the United States
Authors: Bhattacharyya Neil
Published: February 2021

Objective/Hypothesis

Determine contemporary incremental increases in healthcare expenditures and utilization associated with chronic rhinosinusitis (CRS).

Study Design

Cross‐sectional analysis of national health care survey data.

Methods

Patients reporting a diagnosis of CRS were extracted from the 2018 Medical Expenditure Panel Survey medical conditions file and linked to the consolidated expenditures file. CRS patients were then compared to non‐CRS patients determining differences in healthcare utilization for office visits, emergency facility visits, and prescriptions filled as well as differences in total healthcare costs, office‐based costs, prescription medication costs, and self‐expenditures using demographically and comorbidity adjusted multivariate models. Results were compared to 2007, adjusted for inflation.

Results

An estimated 7.28 ± 0.36 million adult patients reported CRS in 2018 (3.0 ± 0.1% of the adult U.S. population). The additional incremental healthcare utilizations associated with CRS relative to non‐CRS patients for office visits, emergency facility visits, and number of prescriptions filled were 4.2 ± 0.6, 0.10 ± 0.03, and 6.0 ± 0.9, respectively (allP ≤ .003). Similarly, additional incremental healthcare expenditures associated with CRS for total health care expenses, office‐based visit expenditures, prescription expenditures, and self‐expenditures were $1,983 ± 569, $772 ± 139, $678 ± 213, and $68 ± 17, respectively (allP ≤ .002). Increases in total (+$1,062) and office based expenditures (+$360) compared to 2007 were significant.

Conclusion

CRS continues to be associated with a substantial incremental increase in healthcare utilization and expenditures. These expenditures have significantly outpaced inflation expected increases. The national healthcare costs of CRS have increased to an estimated $14.4 billion per year.

Level of Evidence

3Laryngoscope, 131:2169–2172, 2021
Cardiac Risk Stratification in Liver Transplantation: Results of a Tiered Assessment Protocol Based on Traditional Cardiovascular Risk Factors
Authors: Robertson Marcus , Chung William , Liu Dorothy , Seagar Rosemary , O’Halloran Tess , Koshy Anoop N. , Horrigan Mark , Farouque Omar , Gow Paul , Angus Peter
Published: February 2021

Coronary artery disease (CAD) confers increased perioperative risk in patients undergoing liver transplantation (LT). Although routine screening for CAD is recommended, there are limited data on the effectiveness of screening strategies. We evaluated the safety and efficacy of a 3‐tiered cardiac risk‐assessment protocol that stratifies patients based on age and traditional cardiac risk factors. We peformed a single‐center, prospective, observational study of consecutive adult patients undergoing LT assessment (2010‐2017). Patients were stratified into low‐risk (LR), intermediate‐risk (IR), or high‐risk (HR) cardiac groups and received standardized investigations with selective use of transthoracic echocardiography (TTE), dobutamine stress echocardiography (DSE), computed tomography coronary angiography (CTCA), and coronary angiography (CA). Primary outcomes were cardiac events (CEs) and cardiovascular death up to 30 days after LT. Overall, 569 patients were included, with 76 patients identified as LR, 256 as IR, and 237 as HR. Cardiac risk factors included diabetes mellitus (26.0%), smoking history (47.3%), hypertension (17.8%), hypercholesterolemia (7.2%), family (17.0%) or prior history of heart disease (6.0%), and obesity (27.6%). Of the patients, 42.0% had ≥2 risk factors. Overall compliance with the protocol was 90.3%. Abnormal findings on TTE, DSE, and CTCA were documented in 3, 23, and 44 patients, respectively, and 12 patients were not listed for transplantation following cardiac assessment (1 LR, 2 IR, and 9 HR). Moderate or severe CAD was identified in 25.4% of HR patients on CTCA following a normal DSE. CEs were recorded in 7 patients (1.2%), with 2 cardiovascular deaths (0.4%). Cardiac risk stratification based on traditional cardiac risk factors with the selective use of DSE, CTCA, and CA is a safe and feasible approach that results in a low perioperative cardiac event rate.
Pepper Alkaloids and Processed Meat Intake: Results from a Randomized Trial and the European Prospective Investigation into Cancer and Nutrition (EPIC) Cohort
Authors: Wedekind Roland , Keski‐Rahkonen Pekka , Robinot Nivonirina , Viallon Vivian , Rothwell Joseph A. , Boutron‐Ruault Marie‐Christine , Aleksandrova Krasimira , Wittenbecher Clemens , Schulze Matthias B. , Halkjær Jytte , Rostgaard‐Hansen Agnetha Linn , Kaaks Rudolf , Katzke Verena , Masala Giovanna , Tumino Rosario , Santucci de Magistris Maria , Krogh Vittorio , Sacerdote Carlotta , Jakszyn Paula , Weiderpass Elisabete , Gunter Marc J. , Huybrechts Inge , Scalbert Augustin
Published: February 2021

Scope

Processed meat intake has been associated with adverse health outcomes. However, little is known about the type of processed meat more particularly responsible for these effects. This study aims to identify novel biomarkers for processed meat intake.

Methods and Results

In a controlled randomized cross‐over dietary intervention study, 12 healthy volunteers consume different processed and non‐processed meats for 3 consecutive days each. Metabolomics analyses are applied on post‐intervention fasting blood and urine samples to identify discriminating molecular features of processed meat intake. Nine and five pepper alkaloid metabolites, including piperine, are identified as major discriminants of salami intake in urine and plasma, respectively. The associations with processed meat intake are tested for replication in a cross‐sectional study (n = 418) embedded within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Three of the serum metabolites including piperine are associated with habitual intake of sausages and to a lesser extent of total processed meat.

Conclusion

Pepper alkaloids are major discriminants of intake for sausages that contain high levels of pepper used as ingredient. Further work is needed to assess if pepper alkaloids in combination with other metabolites may serve as biomarkers of processed meat intake.
Low‐stress over‐molding of media‐tight electronics using thermoplastic foam injection molding
Authors: Ott Constantin , Drummer Dietmar
Published: February 2021

Due to increasing automation and the associated rising demands on electronic assemblies, a suitable manufacturing process for large‐scale production is needed to protect such products. The big challenge in this context is the low‐stress encapsulation of the assemblies to protect them from external influences. In this study, the foam injection molding process was used to encapsulate FR4 (epoxy‐based PCB) with Polyamid66 (PA66). The focus was on the production of a good assembly in terms of the quality of the bond and the media tightness. These parameters can be used to evaluate the protective effect against the surrounding. In the tests, a leakage rate of 0.025 m/min and shear stress of 6.5 MPa was achieved at low‐foaming rates. This leakage is below the maximum acceptable threshold of 0.5 ml/min. The shear stress reaches values comparable to those in injection molding In addition to the requirements for leakage and composite quality, it could be shown that the internal mold pressure is reduced from 450 bar to below 10 bar by foaming. This can be used as the first indication of a reduced shear load on electronic components during over‐molding. The suitability of the new solution concept is demonstrated.
Intrinsic Amorphous Silicon Bilayers for Effective Surface Passivation in Silicon Heterojunction Solar Cells: A Comparative Study of Interfacial Layers
Authors: Sai Hitoshi , Hsu Hung-Jung , Chen Po-Wei , Chen Pei-Ling , Matsui Takuya
Published: February 2021

The impact of intrinsic amorphous silicon bilayers in amorphous silicon/crystalline silicon (a‐Si:H/c‐Si) heterojunction solar cells is investigated. Intrinsic a‐Si:H films with a wide range of film densities and hydrogen contents are prepared via a plasma‐enhanced chemical vapor deposition (PECVD) technique by modifying various process parameters. For silicon heterojunction (SHJ) solar cells with a‐Si:H films applied as single i‐layers, the resulting surface passivation at the a‐Si:H/c‐Si interface is poor. However, surface passivation is significantly improved by applying intrinsic bilayers, which are composed of a porous interfacial layer (≈2 nm) and an overlying dense layer (≈8 nm). The microstructure factor R* of the interfacial a‐Si:H layer, which is related to the SiH bond microstructure and determined by infrared absorption spectroscopy, closely correlates to the surface passivation capability of the bilayers. A variety of PECVD process parameters (temperature, pressure, or precursor gas species) can be utilized to grow an interfacial layer for good surface passivation, provided that its R* is controlled within a suitable range. This indicates that R* is a key universal parameter for optimizing i‐bilayers and realizing high‐efficiency SHJ solar cells.
Effects of Ag2O Nanosheets on the Structural, Optical, and Dielectric Properties of GeO2 Stacked Layers
Authors: Alharbi Seham R. , Qasrawi Atef F. , Algarni Sabah E.
Published: February 2021

Herein, the effects of insertion of Ag2O nanosheets of thicknesses 25–75 nm between stacked layers of GeO2 on the structural, morphological, and optical properties of germanium dioxide are explored. While the stacking of GeO2/Ag2O/GeO2 layers does not alter the amorphous nature of the structure, significant effects on the transmittance, reflectance, absorption coefficient, Urbach's tails, and dielectric constant are observed. Silver oxide nanosheets successfully enhance the light absorbability of germanium dioxide in the visible and the infrared (IR) range of light. The light absorbability is increased by more than 12 times after the insertion of 75 nm‐thick Ag2O nanosheets. In addition, a widening in Urbach's tails and narrowing in the indirect bandgap of GeO2 are detected as a result of increasing Ag2O layer thickness. The dielectric constant and optical conductivity are also increased by ≈59.6% and 191.4% in the IR range of light. The enhancement in the optical properties of GeO2 that results from the insertion of Ag2O nanosheets makes germanium dioxide more appropriate for optoelectronic applications.
Adding Toxicological Context to Nanotoxicity Study Reporting Using the NanoTox Metadata List
Authors: Drobne Damjana
Published: February 2021

This paper proposes a list of specifications (NanoTox metadata list) to be reported about nanotoxicity experiments (metadata) together with resultant data to add toxicological context to reported studies. In areas involving nanomaterials (NMs), existing metadata reporting standards include the reporting of experimental conditions and protocols (MIRIBEL) and material characteristics (MINChar and MIAN), as well as reporting focused on specific experiments (MINBE). NanoCRED is a similarly transparent and structured framework, however, it is developed to guide risk assessors in evaluating the reliability and relevance of NM ecotoxicity studies. There is no reporting standard which would include interpretation of the aims and outcomes of nanotoxicity studies beyond regulatory purposes. The proposed NanoTox metadata reporting checklist is elaborated to extend reporting toward describing nanotoxicological context and thus is a logical complement to technology/material‐assay focused reporting checklists. It is further designed to allow for NM toxicity data and knowledge integration, reuse, and communication. Its ultimate goal is to adhere to the basic rules of toxicology when taking a stand on the toxicity of NMs and to limit speculations on safety. As nanotoxicology becomes more interdisciplinary with the advent of new tools and new materials to be tested, reporting standards will contribute to cross‐disciplinary communication.
Chromosomal Looping‐Based Expression Activation System in Yeast
Authors: Qiu Leilei , Wang Xiaoying , Zhuang Gui , Ouyang Xinhao , Huang Xi
Published: February 2021

There is growing evidence that 3D genome organization is a universal and significant mechanism of gene expression regulation. Tools to manipulate long‐range DNA interactions can advance the accurate control of chromosomal architecture. However, simple eukaryotic systems available to engineer chromosomal looping and gene expression are very limited. This study has developed a tool designated as chromosomal looping‐based expression activation system in yeast (CLEASY). Based on a modified yeast chromosome, it consists of conditionally interacting proteins, distal transcriptional regulatory elements, and a reporter gene. Exogenous chemical or light exposure induces the protein interaction, and results in the proximity of distal regulatory elements bound by these interacting proteins, and ultimately activates the reporter gene. In addition to this controllable induction, this system is compatible with the bivalent Cas9 complexes and their guide RNAs, to ensure target specificity and variability. Therefore, CLEASY can be utilized as a simplified eukaryotic model to engineer DNA looping machinery, and potentially serves as a fast platform to investigate looping mechanism and effective molecules.