bluuebunny/crossref_metadata_2025 huggingface dataset:
Fastness of dye‐based ink‐jet printing inks in aqueous solution in the presence and absence of oxygen
Authors: Blaznik Barbara , Kovač Franci , Bizjak Grega , Bračko Sabina
Published: April 2022

Photodegradation of the ink‐jet prints is a complex process in which many external and internal factors are involved. Nevertheless, the role of colorants and various accompanying substances in the ink is often overlooked. Our research work aimed to determine the fastness of water‐based ink‐jet inks in aqueous solutions. A printing ink often contains a complex mixture of colorants to achieve optimal optical properties of color and a suitable fastness of the print. Therefore, we investigated the composition and stability of cyan, magenta, yellow, and black inks under the influence of UVC light in the presence of oxygen as well as in an inert environment based on TLC chromatography and spectrophotometric analysis. The process of photodegradation was evaluated based on ink amount and half‐life. According to the results, the majority of inks consist of at least two colorants that differ in color and polarity. The results have shown that the presence of oxygen negatively affects the stability of inks; therefore, the inert atmosphere prolongs the durability of ink in water solution.
Boosting Efficiency in Light‐Driven Water Splitting by Dynamic Irradiation through Synchronizing Reaction and Transport Processes**
Authors: Sender Maximilian , Huber Fabian L. , Moersch Maximilian C. G. , Kowalczyk Daniel , Hniopek Julian , Klingler Sarah , Schmitt Michael , Kaufhold Simon , Siewerth Kevin , Popp Jürgen , Mizaikoff Boris , Ziegenbalg Dirk , Rau Sven
Published: April 2022

This work elaborates the effect of dynamic irradiation on light‐driven molecular water oxidation to counteract deactivation. It highlights the importance of overall reaction engineering to overcome limiting factors in artificial photosynthesis reactions. Systematic investigation of a homogeneous three‐component ruthenium‐based water oxidation system revealed significant potential to enhance the overall catalytic efficiency by synchronizing the timescales of photoreaction and mass transport in a capillary flow reactor. The overall activity could be improved by a factor of more than 10 with respect to the turnover number and a factor of 31 referring to the external energy efficiency by controlling the local availability of photons. Detailed insights into the mechanism of light driven water oxidation could be obtained using complementary methods of investigation like Raman, IR, and UV/Vis/emission spectroscopy, unraveling the importance of avoiding high concentrations of excited photosensitizers.
Woody plant secondary chemicals increase in response to abundant deer and arrival of invasive plants in suburban forests
Authors: Morrison Janet A. , Roche Bernadette , Veatch‐Blohm Maren
Published: April 2022

Plants in suburban forests of eastern North America face the dual stressors of high white‐tailed deer density and invasion by nonindigenous plants. Chronic deer herbivory combined with strong competition from invasive plants could alter a plant's stress‐ and defense‐related secondary chemistry, especially for long‐lived juvenile trees in the understory, but this has not been studied. We measured foliar total antioxidants, phenolics, and flavonoids in juveniles of two native trees, Fraxinus pennsylvanica (green ash) and Fagus grandifolia (American beech), growing in six forests in the suburban landscape of central New Jersey, USA. The trees grew in experimental plots subjected for 2.5 years to factorial treatments of deer access/exclosure × addition/no addition of the nonindigenous invasive grass Microstegium vimineum (Japanese stiltgrass). As other hypothesized drivers of plant secondary chemistry, we also measured nonstiltgrass herb layer cover, light levels, and water availability. Univariate mixed model analysis of the deer and stiltgrass effects and multivariate structural equation modeling (SEM) of all variables showed that both greater stiltgrass cover and greater deer pressure induced antioxidants, phenolics, and flavonoids, with some variation between species. Deer were generally the stronger factor, and stiltgrass effects were most apparent at high stiltgrass density. SEM also revealed that soil dryness directly increased the chemicals; deer had additional positive, but indirect, effects via influence on the soil; in beech photosynthetically active radiation (PAR) positively affected flavonoids; and herb layer cover had no effect. Juvenile trees’ chemical defense/stress responses to deer and invasive plants can be protective, but also could have a physiological cost, with negative consequences for recruitment to the canopy. Ecological implications for species and their communities will depend on costs and benefits of stress/defense chemistry in the specific environmental context, particularly with respect to invasive plant competitiveness, extent of invasion, local deer density, and deer browse preferences.
A test of frequency‐dependent selection in the evolution of a generalist phenotype
Authors: Blain Stephanie A. , Chavarie Louise , Kinney Mackenzie H. , Schluter Dolph
Published: April 2022

A solitary population of consumers frequently evolves to the middle of a resource gradient and an intermediate mean phenotype compared to a sympatric pair of competing species that diverge to either side via character displacement. The forces governing the distribution of phenotypes in these allopatric populations, however, are little investigated. Theory predicts that the intermediate mean phenotype of the generalist should be maintained by negative frequency‐dependent selection, whereby alternate extreme phenotypes are favored because they experience reduced competition for resources when rare. However, the theory makes assumptions that are not always met, and alternative explanations for an intermediate phenotype are possible. We provide a test of this prediction in a mesocosm experiment using threespine stickleback that are ecologically and phenotypically intermediate between the more specialized stickleback species that occur in pairs. We manipulated the frequency distribution of phenotypes in two treatments and then measured effects on a focal intermediate population. We found a slight frequency‐dependent effect on survival in the predicted direction but not on individual growth rates. This result suggests that frequency‐dependent selection might be a relatively weak force across the range of phenotypes within an intermediate population and we suggest several general reasons why this might be so. We propose that allopatric populations might often be maintained at an intermediate phenotype instead by stabilizing or fluctuating directional selection.
Effects of density, species interactions, and environmental stochasticity on the dynamics of British bird communities
Authors: Sandal Lisa , Grøtan Vidar , Sæther Bernt‐Erik , Freckleton Robert P. , Noble David G. , Ovaskainen Otso
Published: April 2022

Our knowledge of the factors affecting species abundances is mainly based on time‐series analyses of a few well‐studied species at single or few localities, but we know little about whether results from such analyses can be extrapolated to the community level. We apply a joint species distribution model to long‐term time‐series data on British bird communities to examine the relative contribution of intra‐ and interspecific density dependence at different spatial scales, as well as the influence of environmental stochasticity, to spatiotemporal interspecific variation in abundance. Intraspecific density dependence has the major structuring effect on these bird communities. In addition, environmental fluctuations affect spatiotemporal differences in abundance. In contrast, species interactions had a minor impact on variation in abundance. Thus, important drivers of single‐species dynamics are also strongly affecting dynamics of communities in time and space.
Practical outpatient management of worsening chronic heart failure
Authors: Girerd Nicolas , Mewton Nathan , Tartière Jean‐Michel , Guijarro Damien , Jourdain Patrick , Damy Thibaud , Lamblin Nicolas , Bayes‐Génis Antoni , Pellicori Pierpaolo , Januzzi James L. , Rossignol Patrick , Roubille François ,   a panel of multidisciplinary experts and the Heart Failure Working Group of the French Society of Cardiology
Published: April 2022

Management of worsening heart failure (WHF) has traditionally been hospital‐based, but with the rising burden of heart failure (HF), the pressure on healthcare systems exerted by this disease necessitates a different strategy than long (and costly) hospital stays. A strategy for outpatient intravenous (IV) diuretic treatment of WHF has been developed in certain American centres in the past 10 years, whereas European centres have been mostly favouring ‘classic’ in‐hospital management of WHF. Embracing novel, outpatient approaches for treating WHF could substantially reduce the burden on healthcare systems while improving patient's satisfaction and quality of life. The present article is intended to provide essential knowledge and practical guidelines aimed at helping clinicians implement these new ambulatory approaches using day hospital and/or at‐home hospitalization. The topics addressed by our group of HF experts include the pathophysiological background of diuretic therapy, the most suitable profile of WHF that may be managed in an ambulatory setting, the pharmacological protocols that can be used, as well as a detailed description of healthcare structures that can be proposed to deliver these ambulatory care interventions. The practical aspects of day hospital and hospital‐at‐home IV diuretic administration are specifically emphasized. The algorithm provided along with the practical IV diuretic protocols should assist HF clinicians in implementing this new approach in their local clinical setting.
Unmasking the prevalence of amyloid cardiomyopathy in the real world: results from Phase 2 of the AC‐TIVE study, an Italian nationwide survey
Authors: Merlo Marco , Pagura Linda , Porcari Aldostefano , Cameli Matteo , Vergaro Giuseppe , Musumeci Beatrice , Biagini Elena , Canepa Marco , Crotti Lia , Imazio Massimo , Forleo Cinzia , Cappelli Francesco , Perfetto Federico , Favale Stefano , Di Bella Gianluca , Dore Franca , Girardi Francesca , Tomasoni Daniela , Pavasini Rita , Rella Valeria , Palmiero Giuseppe , Caiazza Martina , Carella Maria Cristina , Igoren Guaricci Andrea , Branzi Giovanna , Caponetti Angelo Giuseppe , Saturi Giulia , La Malfa Giovanni , Merlo Andrea Carlo , Andreis Alessandro , Bruno Francesco , Longo Francesca , Rossi Maddalena , Varrà Guerino Giuseppe , Saro Riccardo , Di Ienno Luca , De Carli Giuseppe , Giacomin Elisa , Arzilli Chiara , Limongelli Giuseppe , Autore Camillo , Olivotto Iacopo , Badano Luigi , Parati Gianfranco , Perlini Stefano , Metra Marco , Emdin Michele , Rapezzi Claudio , Sinagra Gianfranco
Published: April 2022

Aim

To investigate the prevalence of amyloid cardiomyopathy (AC) and the diagnostic accuracy of echocardiographic red flags of AC among consecutive adult patients undergoing transthoracic echocardiogram for reason other than AC in 13 Italian institutions.

Methods and results

This is an Italian prospective multicentre study, involving a clinical and instrumental work‐up to assess AC prevalence among patients ≥55 years old with an echocardiogram suggestive of AC (i.e. at least one echocardiographic red flag of AC in hypertrophic, non‐dilated left ventricles with preserved ejection fraction). The study was registered at
ClinicalTrials.gov (NCT04738266). Overall, 381 patients with an echocardiogram suggestive of AC were identified among a cohort of 5315 screened subjects, and 217 patients completed the investigations. A final diagnosis of AC was made in 62 patients with an estimated prevalence of 29% (95% confidence interval 23%–35%). Transthyretin‐related AC (ATTR‐AC) was diagnosed in 51 and light chain‐related AC (AL‐AC) in 11 patients. Either apical sparing or a combination of ≥2 other echocardiographic red flags, excluding interatrial septum thickness, provided a diagnostic accuracy >70%.

Conclusion

In a cohort of consecutive adults with echocardiographic findings suggestive of AC and preserved left ventricular ejection fraction, the prevalence of AC (either ATTR or AL) was 29%. Easily available echocardiographic red flags, when combined together, demonstrated good diagnostic accuracy.
Natural killer cell‐mediated ADCC in SARS‐CoV‐2‐infected individuals and vaccine recipients
Authors: Hagemann Kerri , Riecken Kristoffer , Jung Johannes M. , Hildebrandt Heike , Menzel Stephan , Bunders Madeleine J. , Fehse Boris , Koch‐Nolte Friedrich , Heinrich Fabian , Peine Sven , Schulze zur Wiesch Julian , Brehm Thomas T. , Addo Marylyn M. , Lütgehetmann Marc , Altfeld Marcus
Published: April 2022

COVID‐19, caused by SARS‐CoV‐2, has emerged as a global pandemic. While immune responses of the adaptive immune system have been in the focus of research, the role of NK cells in COVID‐19 remains less well understood. Here, we characterized NK cell‐mediated SARS‐CoV‐2 antibody‐dependent cellular cytotoxicity (ADCC) against SARS‐CoV‐2 spike‐1 (S1) and nucleocapsid (NC) protein. Serum samples from SARS‐CoV‐2 resolvers induced significant CD107a‐expression by NK cells in response to S1 and NC, while serum samples from SARS‐CoV‐2‐negative individuals did not. Furthermore, serum samples from individuals that received the BNT162b2 vaccine induced strong CD107a expression by NK cells that increased with the second vaccination and was significantly higher than observed in infected individuals. As expected, vaccine‐induced responses were only directed against S1 and not against NC protein. S1‐specific CD107a responses by NK cells were significantly correlated to NK cell‐mediated killing of S1‐expressing cells. Interestingly, screening of serum samples collected prior to the COVID‐19 pandemic identified two individuals with cross‐reactive antibodies against SARS‐CoV‐2 S1, which also induced degranulation of NK cells. Taken together, these data demonstrate that antibodies induced by SARS‐CoV‐2 infection and anti‐SARS‐CoV‐2 vaccines can trigger significant NK cell‐mediated ADCC activity, and identify some cross‐reactive ADCC‐activity against SARS‐CoV‐2 by endemic coronavirus‐specific antibodies.
Mesenchymal stromal cells‐derived small extracellular vesicles modulate DC function to suppress Th2 responses via IL‐10 in patients with allergic rhinitis
Authors: Peng Ya‐Qi , Wu Zi‐Cong , Xu Zhi‐Bin , Fang Shu‐Bin , Chen De‐Hua , Zhang Hong‐Yu , Liu Xiao‐Qing , He Bi‐Xin , Chen Dong , Akdis Cezmi A. , Fu Qing‐Ling
Published: April 2022

Mesenchymal stromal cells (MSCs) are well known for their immunoregulatory roles on allergic inflammation particularly by acting on T cells, B cells, and dendritic cells (DCs). MSC‐derived small extracellular vesicles (MSC‐sEV) are increasingly considered as one of the main factors for the effects of MSCs on immune responses. However, the effects of MSC‐sEV on DCs in allergic diseases remain unclear.

MSC‐sEV were prepared from the induced pluripotent stem cells (iPSC)‐MSCs by anion‐exchange chromatography, and were characterized with the size, morphology, and specific markers. Human monocyte‐derived DCs were generated and cultured in the presence of MSC‐sEV to differentiate the so‐called sEV‐immature DCs (sEV‐iDCs) and sEV‐mature DCs (sEV‐mDCs), respectively. The phenotypes and the phagocytic ability of sEV‐iDCs were analyzed by flow cytometry. sEV‐mDCs were co‐cultured with isolated CD4+T cells or peripheral blood mononuclear cells (PBMCs) from patients with allergic rhinitis. The levels of Th1 and Th2 cytokines produced by T cells were examined by ELISA and intracellular flow staining. And the following mechanisms were further investigated.

We demonstrated that MSC‐sEV inhibited the differentiation of human monocytes to iDCs with downregulation of the expression of CD40, CD80, CD86, and HLA‐DR, but had no effects on mDCs with these markers. However, MSC‐sEV treatment enhanced the phagocytic ability of mDCs. More importantly, using anti‐IL‐10 monoclonal antibody or IL‐10Rα blocking antibody, we identified that sEV‐mDCs suppressed the Th2 immune response by reducing the production of IL‐4, IL‐9, and IL‐13 via IL‐10. Furthermore, sEV‐mDCs increased the level of Treg cells.

Our study identified that mDCs treated with MSC‐sEV inhibited the Th2 responses, providing novel evidence of the potential cell‐free therapy acting on DCs in allergic airway diseases.
Establishing an individualized model of conversion from normal cognition to Alzheimer's disease after 4 years, based on cognitive, brain morphology and neuropsychiatric characteristics
Authors: Ronat Lucas , Hoang Van‐Tien , Hanganu Alexandru
Published: April 2022

Objectives

The impact of neuropsychiatric symptoms (NPS) on cognitive performance has been reported, and this impact was better defined in the aging population. Yet the potential of using the impact of NPS on brain and cognitive performance in a longitudinal setting, as prediction of conversion – have remained questionable. This study proposes to establish a predictive model of conversion to Alzheimer's disease (AD) and mild cognitive impairment (MCI) based on current cognitive performance, NPS and their associations with brain morphology.

Methods

156 participants with MCI from the Alzheimer's Disease Neuroimaging Initiative database cognitively stable after a 4‐year follow‐up were compared to 119 MCI participants who converted to AD. Each participant underwent a neuropsychological assessment evaluating verbal memory, language, executive and visuospatial functions, a neuropsychiatric inventory evaluation and a 3 Tesla MRI. The statistical analyses consisted of 1) baseline comparison between the groups; 2) analysis of covariance model (controlling demographic parameters including functional abilities) to specify the variables that distinguish the two subgroups and; 3) used the significant ANCOVA variables to construct a binary logistic regression model that generates a probability equation to convert to a lower cognitive performance state.

Results

Results showed that MCI who converted to AD in comparison to stable MCI, exhibited a higher NPS prevalence, a lower cognitive performance and a higher number of involved brain structures. Functional abilities, memory performance and the sizes of inferior temporal, hippocampal and amygdala sizes were significant predictors of MCI to AD conversion. We also report two models of conversion that can be implemented on an individual basis for calculating the percentage risk of conversion after 4 years.

Conclusion

These analytical methods might be a good way to anticipate cognitive and brain declines.
Medicare reimbursement trends from 2000 to 2020 in head and neck surgical oncology
Authors: Quereshy Humzah A. , Quinton Brooke A. , Cabrera Claudia I. , Li Shawn , Tamaki Akina , Fowler Nicole
Published: April 2022

Background

Considering limited data exploring reimbursement trends at the subspecialty level within head and neck surgical oncology, we sought to characterize these trends for head and neck‐specific codes from 2000 to 2020.

Methods

Using the Centers for Medicare and Medicaid Services' Physician Fee Schedule Look‐Up Tool, reimbursement data, adjusted to 2020 U.S. dollars, for 37 head and neck surgical oncologic procedure codes were collected from 2000 to 2020.

Results

From 2000 to 2020, despite gross reimbursement for all head and neck procedures increasing by 23.2%, when adjusted for inflation, physician reimbursement decreased by 19.4%. Only 4 of 37 examined codes increased in net reimbursement over the study period.

Conclusion

Medicare reimbursement for the most common head and neck oncologic procedure codes decreased from 2000 to 2020. Further research is necessary to explore the implications of these trends on the delivery of patient care.
Congenital malformations: Prevalence and characteristics of newborns admitted into Federal Medical Center, Asaba
Authors: Chimah Osaretin U. , Emeagui Kennedy N. , Ajaegbu Obinna C. , Anazor Chioma V. , Ossai Chukwuma A. , Fagbemi Adeniyi J. , Emeagui Omoadoni D.
Published: April 2022

Background

Congenital malformations account for a significant cause of perinatal mortality and morbidity. Understanding the burden and pattern of congenital malformation is key in monitoring the trend and improving the health care of neonates especially those in low‐income countries.

Objective

This was a prospective cross‐sectional study to determine the prevalence and characteristics of congenital malformations among neonates admitted to the neonatal unit.

Method

All newborns with congenital malformation admitted into the neonatal unit of Federal Medical Center, Asaba whose parents gave consent were recruited for the study for a 1‐year period from January 2020 to December 2020. Appropriately indicated laboratory and radio‐diagnostic investigations were done to confirm internal anomalies. Data were collected using a structured questionnaire and analyzed with a statistical package for social sciences version 26.0.

Results

The total admission for the period was 752 with 46 of the neonates (6.1%) having congenital malformation. The predominant system affected was the cardiovascular system (57%), central nervous system (33%), and digestive system (30%). Atrioventricular septal defect (31%) and patent ductus arteriosus (31%) were the commonest types of cardiovascular malformation. A significant number of newborns with congenital anomalies died (43.5%).

Conclusion

Congenital malformation was seen among one in 18 neonates affecting mostly the cardiovascular and central nervous system. A high index of suspicion, early complete physical examination, and radio‐diagnostic investigations are relevant for the complete evaluation of CM in neonates. Advanced maternal age was associated with the presence of multiple organ anomalies.
Mortality in hospitalized older adults with COVID‐19 during three waves: A multicenter retrospective cohort study
Authors: Wong Eric Kai Chung , Watt Jennifer , Zou Hanyan , Chandraraj Arthana , Zhang Alissa W. , Norman Richard , Piggott Katrina Lynn , Straus Sharon E. , Liu Barbara
Published: April 2022

Background

The waves of COVID‐19 infections in Ontario, Canada, were marked by differences in patient characteristics and treatment. Our objectives were to (i) describe patient characteristics, treatment, and outcomes of hospitalized older adults with COVID‐19 between waves 1, 2, and 3, (ii) determine if there was an improvement in in‐hospital mortality in waves 2 and 3 after adjusting for covariates.

Methods

This retrospective cohort study was done in five acute care hospitals in Toronto, Ontario. Consecutive hospitalized older adults aged ≥65 years with confirmed COVID‐19 infection were included. Wave 1 extended from March 11 to July 31, 2020, wave 2 from August 1, 2020 to February 20, 2021, and wave 3 from February 21 to June 30, 2021. Patient characteristics and outcomes were abstracted from charts. A logistic regression model was used to determine the association between COVID‐19 and in‐hospital mortality in waves 2 and 3 compared with wave 1.

Results

Of the 1671 patients admitted to acute care, 297 (17.8%) were admitted in wave 1, 751 (44.9%) in wave 2, and 623 (37.3%) in wave 3. The median age of our cohort was 77.0 years (interquartile range: 71.0–85.0) and 775 (46.4%) were female. The prevalence of frailty declined in progressive waves. The use of dexamethasone, remdesivir, and tocilizumab was significantly higher in waves 2 and 3 compared with wave 1. In the unadjusted analysis, in‐hospital mortality was unchanged between waves 1 and 2, but it was lower in wave 3 (18.3% vs. 27.4% in wave 1). After adjustment, in‐hospital mortality was unchanged in waves 2 and 3 compared with wave 1.

Conclusion

In‐hospital mortality in hospitalized older adults with COVID‐19 was similar between waves 1 and 3. Further research should be done to determine if COVID‐19 therapies have similar benefits for older adults compared with younger adults.
Unveiling the black swan of the finance‐growth Nexus: Assumptions and preliminary evidence of virtuous and unvirtuous cycles
Authors: Lauretta Eliana , Chaudhry Sajid M. , Santamaria Daniel
Published: April 2022

Empirical evidence behind the nature of the finance‐growth nexus and mediating drivers behind this association is well documented in the literature. However, a framework that depicts the association between credit creation, financial innovation and endogenous creation of boom‐bust cycles is less evident and the gap between empirical research and theoretical development remains. Hence, this study represents a first attempt to provide a framework that could explain the switch of economic cycles from virtuous to unvirtuous and vice versa. We examine the role of financial innovation and identify its “hidden soul” defined as the rate of financial innovation (RoFIN). We study RoFIN together with other structural factors, such as monopolistic financial power concentration and financial deregulation in the creation of what we identify as the wealth trap, as a potential mediating factor behind the creation of virtuous and unvirtuous cycles. A cross‐country statistical exercise using the VUC indicator on the United States, United Kingdom, and Euro area economies shows the exponential effect of the rate of financial innovation over time and provides indicative evidence in support of our framework. Finally, we report that the indicator is better able to identify the unvirtuous cycle stages than the traditionally used Credit‐to‐GDP ratio.
Brain tumor detection and patient survival prediction using U‐Net and regression model
Authors: Asthana Pallavi , Hanmandlu Madasu , Vashisth Sharda
Published: April 2022

Brain tumor segmentation is necessitated to ascertain the severity of tumor growth in a brain for possible treatment planning. In this work, we attempt the development of U‐Net‐based semantic segmentation of brain tumors. This network model is trained and tested on three MRI datasets: Brats 2018, Brats 2019, and Brats 2020. The trained U‐Net yields the dice scores of 0.893, 0.837, and 0.753 on Brats 2018; 0.912, 0.891, and 0.808 on Brats 2019, and of 0.917, 0.894, and 0.811 on Brats 2020 for the complete tumor, tumor core, and enhancing tumor respectively. This paper also presents a novel formulation of a regression model based on an Information set to predict the survival rates of patients affected with a brain tumor. The weights of the regression model are learned using the pervasive learning model based on the pervasive information set. The overall survival rates of patients are predicted using the proposed regression model on the three datasets for which High‐Grade Gliomas subjects are considered, and the model achieves the accuracies of 64.2%, 59.8%, and 60.5% on Brats 2018, 2019, and 2020 datasets respectively.
Mechanistic study on the coupling reaction of CO2 with propylene oxide catalyzed by (CH3)4PI·MgCl2
Authors: Ali Jemal Mohamed , Mohammed Ahmed Mustefa , Mekonnen Yedilfana Setarge
Published: April 2022

The mechanistic study of CO2 coupling with propylene oxide (PO) into cyclic carbonate catalyzed by (CH3)4PI has been investigated using the B3LYP/6‐311++G (d, p)/B3LYP/6‐31G (d) level of theory for non‐iodine atoms and LANL2DZ was used, together with its associated basis set for the iodine atom. Two hypothetical reaction mechanisms were proposed for the studied reaction and thermodynamic and kinetic parameters were computed for each step to determine the more favorable route. The density functional theory (DFT) study reveals that the reaction prefers to proceed through a three‐step mechanism (pathway II) than a tri‐molecular intermediate (pathway I) where the CO2 and the catalyst act simultaneously on the PO ring. The rate‐determining step of the catalytic reaction is found to be the ring‐opening step with an energy barrier of 27.1 kcal/mol (pathway II) in the gas phase, which is kinetically more favorable than that of non‐catalytic CO2 fixation with a relatively higher barrier of 63.7 kcal/mol. The synergetic effect of MgCl2 is tested as a cocatalyst for the (CH3)4PI/MgCl2 catalyzed reaction and it gave a better result and minimized the activation energy for the reaction and the rate‐determining step was the ring closure with the free energy of activation 18.8 kcal/mol in the gas phase. The polarizable continuum model was used to account for the solvent effect, obtaining the best results of 23.1 kcal/mol in water for pathway I and 16.5 kcal/mol and 14.9 kcal/mol in dimethyl sulfoxide for pathway II and binary system, respectively.
Fulleride‐metal η5 sandwich and multi‐decker sandwich complexes: A DFT prediction
Authors: Anila Sebastian , Suresh Cherumuttathu H.
Published: April 2022

The (C60CN)− formed by the reaction of CN− with fullerene shows high electron rich character, very similar to C60˙−, and it behaves as a large anion. Similar to Cp−, the bulky anion, (C60CN)−, acts as a strong η5 ligand towards transition metal centers. Previous studies on η5 coordination of fullerene cage are reported for pseudo fullerenes whereas the present study deals with sandwich complexes of (C60CN)− with Fe(II), Ru(II), Cr(II), Mo(II), and Ni(II) and multi‐decker sandwich complexes of CN–fullerides with Fe(II). The structural parameters of these complexes and the corresponding Cp− complexes showed very close resemblance. Analysis of the metal‐to‐carbon bonding molecular orbitals showed that sandwich complex [Fe(η5‐(C60CN)−)2] exhibit bonding features very similar to that of ferrocene. Also, a 6‐fold decrease in the band gap energy is observed for [Fe(η5‐(C60CN)−)2] compared to ferrocene. The energy of dissociation (ΔE) of the ligand (C60CN)− from [Fe(η5‐(C60CN)−)2] is slightly lower than the ΔE of a Cp* ligand from a ferrocene derivative wherein each cyclopentadienyl unit is substituted with four tertiary butyl groups. The (C60CN)− ligand behaved as one of the bulkiest ligands in the chemistry of sandwich complexes. Further, the coordinating ability of the dianion, (C60(CN)2)2− is evaluated which showed strong coordination ability simultaneously with two metal centers leading to the formation of multi‐decker sandwich and pearl‐necklace type polymeric structures.
A pyrosequencing protocol for rapid identification of SARS‐CoV‐2 variants
Authors: Allen Richard A. , Williams Christopher L. , Penrod Yvonne , McCloskey Cindy , Carpenter‐Azevedo Kristin , Huard Richard C. , King Ewa , Terence Dunn Samuel
Published: April 2022

Next‐generation sequencing (NGS) is the primary method used to monitor the distribution and emergence of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) variants around the world; however, it is costly and time‐consuming to perform and is not widely available in low‐resourced geographical regions. Pyrosequencing has the potential to augment surveillance efforts by providing information on specific targeted mutations for rapid identification of circulating and emerging variants. The current study describes the development of a reverse transcription (RT)‐PCR‐pyrosequencing assay targeting >65 spike protein gene (S) mutations of SARS‐CoV‐2, which permits differentiation of commonly reported variants currently circulating in the United States with a high degree of confidence. Variants typed using the assay included B.1.1.7 (Alpha), B.1.1.529 (Omicron), B.1.351 (Beta), B.1.375, B.1.427/429 (Epsilon), B.1.525 (Eta), B.1.526.1 (Iota), B.1.617.1 (Kappa), B.1.617.2 (Delta), B.1.621 (Mu), P1 (Gamma), and B.1.1 variants, all of which were confirmed by the NGS data. An electronic typing tool was developed to aid in the identification of variants based on mutations detected by pyrosequencing. The assay could provide an important typing tool for rapid identification of candidate patients for monoclonal antibody therapies and a method to supplement SARS‐CoV‐2 surveillance efforts by identification of circulating variants and novel emerging lineages.
Clinical findings from the landmark MEF2C‐related disorders natural history study
Authors: Cooley Coleman Jessica A. , Sarasua Sara M. , Moore Hannah Warren , Boccuto Luigi , Cowan Christopher W. , Skinner Steven A. , DeLuca Jane M.
Published: April 2022

Introduction

MEF2C‐related disorders are characterized by developmental and cognitive delay, limited language and walking, hypotonia, and seizures. A recent systematic review identified 117 patients with MEF2C‐related disorders across 43 studies. Despite these reports, the disorder is not easily recognized and assessments are hampered by small sample sizes. Our objective was to gather developmental and clinical information on a large number of patients.

Methods

We developed a survey based on validated instruments and subject area experts to gather information from parents of children with this condition. No personal identifiers were collected. Surveys and data were collected via REDCap and analyzed using Excel and SAS v9.4.

Results

Seventy‐three parents completed the survey, with 39.7% reporting a MEF2C variant and 54.8% reporting a deletion involving MEF2C. Limited speech (82.1%), seizures (86.3%), bruxism (87.7%), repetitive movements (94.5%), and high pain tolerance (79.5%) were some of the prominent features. Patients with MEF2C variants were similarly affected as those with deletions. Female subjects showed higher verbal abilities.

Conclusion

This is the largest natural history study to date and establishes a comprehensive review of developmental and clinical features for MEF2C‐related disorders. This data can help providers diagnose patients and form the basis for longitudinal or genotype–phenotype studies.
Risk factors associated with fixation‐related complications in microsurgical free flap reconstruction of the mandible
Authors: de Vicente Juan C. , Rodríguez‐Santamarta Tania , de Villalaín Lucas , Ruiz‐Ranz Marta , Rodríguez‐Torres Nerea , Cobo Juan L.
Published: April 2022

Background

Hardware complications (loosening of screws, infection, or exposure of the plate) in mandibular reconstruction with vascularized osseous free flaps impose significant morbidity, and frequently require revision surgery. Purpose of this study was to identify possible contributing factors for hardware complications.

Methods

This is a retrospective cohort study involving case series of patients who underwent microvascular mandible reconstructions between 2000 and 2020. Patient demographics, pathological, clinical, and treatment‐related factors were analyzed in univariate and multivariate analyses.

Results

Ninety‐one patients were enrolled, encompassing 63 reconstructions with fibular free flaps, 26 reconstructions with scapular, and 2 reconstructions with iliac flaps. Rate of hardware complications and plate exposure was 14.3% and 7.7%, respectively, with a median follow‐up time for extrusion of 29 months. In univariate analysis, preoperative radiotherapy (odds ratio [OR] = 6.57, p = .01), and secondary mandible reconstruction (OR = 4.3, p = .04) were significant predictors of hardware complications, and plate exposure was most frequently found in secondary reconstruction (37.5%, OR = 11.8, p = .04). Hypertension was the most commonly found comorbidity (24%), and it trended toward significance regarding plate exposure (p = .05). Only secondary mandible reconstruction was associated with osteosynthesis complications (OR = 12.53, p = .01) and plate exposure (OR = 23.86, p = .005) on multivariate analysis, while preoperative radiation therapy did not retain its relevance on plate exposure.

Conclusion

Secondary mandible reconstructions with vascularized osseous free flaps have a higher risk of osteosynthesis complications than primary reconstructions.
A 9 dB back‐off dual‐band asymmetric Doherty power amplifier using dual peaking amplifiers for reactance compensation
Authors: Xia Jing , Xie Zhonghui , Kong Wa , Liu Ruijia , Zhao Ziming , Zhu Xiao‐Wei
Published: April 2022

This paper proposes a dual‐band asymmetric Doherty power amplifier (ADPA) with 9 dB power back‐off range using dual parallel peaking amplifiers to realize reactance compensation for wideband operation at two frequency bands. To achieve dual‐band amplification, the specific phase delays of the carrier and peaking output matching networks (OMNs) required on the two target frequency bands were determined using the phase delay period repeatability principle combined with the Doherty impedance transformation first. Then, the carrier and peaking OMNs were designed according to the desired phase delay. More specifically, two parallel peaking amplifiers using the low‐order impedance transformation network were combined to generate the desired compensating reactance at the back‐off power range for wideband operation. For verification, a dual‐band ADPA operating over 2.35–2.75 and 3.2–3.6 GHz frequency bands was designed and measured. Experimental results show that, for the two frequency bands, the efficiencies at saturation are 53.6%–64.3% and 48%–67.8%, with the 9 dB back‐off efficiencies reaching 41.5%–53.3% and 40.5%–52.8%, respectively. When stimulated by a 20 MHz modulated signal, the designed ADPA can achieve the adjacent channel leakage ratio of −48 dBc after linearization.
A multisection‐feed multiband notch antenna for most wireless standards
Authors: Niamien Constant M. A.
Published: April 2022

This paper presents an unsophisticated compact straight notch with an optimized multisection feed. The design principle invokes the notch's first two resonant modes to set the operating bands. Then, two integrated capacitors and a multisection feed are fine‐set through a “quick” optimization process to cover GSM900 up to Wi‐Fi/5 GHz bands under S11 ≤ –10 dB. Finally, this optimized design is fabricated and validated experimentally. The covered bands are 940−1050 MHz (11.05%), 1710−2890 MHz (51.30%), 4845−5423 MHz (11.25%), and 5771−5970 MHz (3.38%), with a peak realized gain ranging between 1.2 and 5 dBi. The proposed antenna is attractive for mobile applications, particularly for ambient energy harvesting, where collecting power from every direction over a broad frequency range is crucial.
Development of an ultra‐thin parallel plate ionization chamber for dosimetry in FLASH radiotherapy
Authors: Gómez Faustino , Gonzalez‐Castaño Diego M. , Fernández Nicolás Gómez , Pardo‐Montero Juan , Schüller Andreas , Gasparini Alessia , Vanreusel Verdi , Verellen Dirk , Felici Giuseppe , Kranzer Rafael , Paz‐Martín Jose
Published: April 2022

Background

Conventional air ionization chambers (ICs) exhibit ion recombination correction factors that deviate substantially from unity when irradiated with dose per pulse magnitudes higher than those used in conventional radiotherapy. This fact makes these devices unsuitable for the dosimetric characterization of beams in ultra‐high dose per pulse as used for FLASH radiotherapy.

Purpose

We present the design, development, and characterization of an ultra‐thin parallel plate IC that can be used in ultra‐high dose rate (UHDR) deliveries with minimal recombination.

Methods

The charge collection efficiency (CCE) of parallel plate ICs was modeled through a numerical solution of the coupled differential equations governing the transport of charged carriers produced by ionizing radiation. It was used to find out the optimal parameters for the purpose of designing an IC capable of exhibiting a linear response with dose (deviation less than 1%) up to 10 Gy per pulse at 4
s pulse duration. As a proof of concept, two vented parallel plate IC prototypes have been built and tested in different ultra‐high pulse dose rate electron beams.

Results

It has been found that by reducing the distance between electrodes to a value of 0.25 mm it is possible to extend the dose rate operating range of parallel plate ICs to ultra‐high dose per pulse range, at standard voltage of clinical grade electrometers, well into several Gy per pulse. The two IC prototypes exhibit behavior as predicted by the numerical simulation. One of the so‐called ultra‐thin parallel plate ionization chamber (UTIC) prototypes was able to measure up to 10 Gy per pulse, 4
s pulse duration, operated at 300 V with no significant deviation from linearity within the uncertainties (ElectronFlash Linac, SIT). The other prototype was tested up to 5.4 Gy per pulse, 2.5
s pulse duration, operated at 250 V with CCE higher than 98.6% (Metrological Electron Accelerator Facility, MELAF at Physikalisch‐Technische Bundesanstalt, PTB).

Conclusions

This work demonstrates the ability to extend the dose rate operating range of ICs to ultra‐high dose per pulse range by reducing the spacing between electrodes. The results show that UTICs are suitable for measurement in UHDR electron beams.
Critical review of bariatric surgical outcomes in patients with Prader‐Willi syndrome and other hyperphagic disorders
Authors: Gantz Marie G. , Driscoll Daniel J. , Miller Jennifer L. , Duis Jessica B. , Butler Merlin G. , Gourash Linda , Forster Janice , Scheimann Ann O.
Published: April 2022

Objective

The aim of this study was to review bariatric procedure outcomes among patients with Prader‐Willi syndrome (PWS), melanocortin 4 receptor (MC4R) mutations, Bardet‐Biedl syndrome, and hypothalamic obesity.

Methods

Systematic published literature review used the following search terms: “Prader‐Willi syndrome,” “Bardet‐Biedl syndrome,” “hyperphagia,” “bariatric surgery,” “MC4R”/“melanocortin 4 receptor”, “hypothalamic obesity,” and “bariatric procedure.” Information collected included demographics, genetics, anthropometry, procedure type, outcomes, and complications, with inclusion of case series and clinical reports given the rarity of the disorders. For PWS, postoperative weight‐change percentage and BMI up to 14 years following surgery were analyzed using general linear mixed models, with descriptive outcomes for other conditions.

Results

A total of 54 publications were identified, with variable follow‐up periods for 202 patients (114 with PWS, 43 with MC4R mutations, 7 with Bardet‐Biedl syndrome, and 38 with hypothalamic obesity) among bariatric procedures. Weight loss of patients with PWS was greatest within 1 year of surgery, with weight‐change percentage not significantly different from 0 at 5 years. Long‐term results in other conditions were variable and featured suboptimal weight loss and increased reoperation risk.

Conclusions

Bariatric procedures among hyperphagic individuals, including those with PWS, report variable results and outcomes. Benefits of bariatric surgery may be less durable in hyperphagic disorders in comparison with other patients with severe obesity.
Financial burden for caregivers of adolescents and young adults with cancer
Authors: Nightingale Chandylen L. , Canzona Mollie R. , Danhauer Suzanne C. , Reeve Bryce B. , Howard Dianna S. , Tucker‐Seeley Reginald D. , Golden Shannon L. S. , Little‐Greene Denisha , Roth Michael E. , Victorson David E. , Salsman John M.
Published: April 2022

Objective

Adolescent and young adult (AYA) cancer survivors are vulnerable to cancer‐related financial burden, which is likely shared by their caregivers. This study aims to enhance an existing conceptual model of financial burden by conducting concept elicitation interviews with caregivers to generate knowledge that can be translated to inform instrumental and psychosocial support in cancer care.

Methods

Qualitative concept elicitation interviews were conducted with 24 caregivers of AYA cancer survivors (caregivers of adolescents, n = 12; caregivers of emerging adults, n = 12) recruited from four sites. Constant comparative methods were used to identify themes, and results were interpreted and organized into domains of the conceptual model. We also explored COVID‐19 related financial impacts among a subset (n = 12) of caregivers.

Results

Seven themes emerged, which varied by age group and strengthened the conceptualization of the model. Themes centered on: (1) direct and indirect costs of cancer; (2) impact of socioeconomic status on financial burden; (3) caregiver desire to shield AYAs from distress due to financial burden; (4) strategies to manage cancer‐related costs; (5) worries about AYAs' financial future; (6) seeking and receiving financial support; and (7) navigating the healthcare system. Findings also revealed that COVID‐19 exacerbates financial burden for some caregivers.

Conclusions

Building upon our prior work, we have adapted the conceptual model of financial burden to reflect perspectives of AYAs, oncology providers, and now, caregivers. An important next step is to develop a reliable and valid self‐report measure of financial burden among caregivers of AYA cancer survivors.
Association between requests for supportive care assistance and patients' characteristics, prior to treatment in a comprehensive cancer center
Authors: Razavi Marianne , Bergerot Cristiane Decat , Clark Karen Lynn , Loscalzo Matthew , Nuristani Hussai , Obenchain Richard , Baik Sharon H. , Dale William
Published: April 2022

Purpose

Patients with cancer experience a wide array of distress symptoms (emotional, practical, physical, and functional), which often hinders their quality of life and survival. Unfortunately, only a small proportion of these patients request assistance for these problems. This study explored the relationship between requests for supportive care assistance and distress of patients newly diagnosed with cancer.

Methods

This study was conducted at city of hope, an NCI‐designated comprehensive cancer center, and included 2658 patients treated between 2009 and 2017. Patients were asked to complete a 30‐item biopsychosocial problem‐related distress survey via SupportScreen®, prior to any treatment. Correlations between requests for assistance and distress domains were evaluated. Primary types of requests were examined for all patients, and general linear modeling was used to determine the significant predictors of requests for assistance. p‐values <0.05 were considered significant.

Results

Strong correlations were observed between distress subscales and requests for assistance (r ranging from 0.67 to 0.69). The primary types of requests varied by domain: items such as feeling anxious or fearful, finances, and sleep ranked first within the emotional, practical, and physical‐functional domains respectively (∼20% requests for each item). Verbal assistance was generally preferred to the written form of assistance, with the exception of a few items, including finances. Overall, household income of <$100,000 and completing the survey in Spanish were significant predictors of requests for assistance. Regarding the practical and physical‐functional domains, having an advanced stage of disease was significantly related to an increase in demands for assistance. Being older was associated to a decrease in requests for assistance vis‐à‐vis both the emotional and physical functional subscales.

Conclusion

We demonstrated that distress levels were strongly correlated with requests for assistance. Patients' clinical and demographic characteristics such as age, household income, disease stage and survey language were associated with inquiries for psychosocial support, highlighting the importance of targeting interventions towards those most likely to need them, to better aim patients' needs. Therefore, tailoring supportive care assistance to patients' characteristics could help boost the frequency of requests, reduce distress burden, and improve health outcomes.