bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

AbstractBackgroundCongenital 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.ObjectiveThis was a prospective cross‐sectional study to determine the prevalence and characteristics of congenital malformations among neonates admitted to the neonatal unit.MethodAll 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.ResultsThe 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%).ConclusionCongenital 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

AbstractBackgroundThe 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.MethodsThis 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.ResultsOf 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.ConclusionIn‐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

AbstractEmpirical 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

AbstractBrain 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

AbstractThe 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

AbstractThe (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

AbstractNext‐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

AbstractIntroductionMEF2C‐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.MethodsWe 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.ResultsSeventy‐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.ConclusionThis 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

AbstractBackgroundHardware 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.MethodsThis 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.ResultsNinety‐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.ConclusionSecondary 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

AbstractThis 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

AbstractThis 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

AbstractBackgroundConventional 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.PurposeWe 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.MethodsThe 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.ResultsIt 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).ConclusionsThis 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

AbstractObjectiveThe 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.MethodsSystematic 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.ResultsA 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.ConclusionsBariatric 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.