bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of the Unique Viscoelastic Properties of the Mitral Valve Anterior Leaflet
Authors: Figueroa Lysmarie , Brazile Bryn , Lin Sallie , Nelson Brandon , Liao Jun 
Published: June 2021

The most common mitral valve (MV) disease is the MV regurgitation, in which the anterior leaflet and the posterior leaflet cannot coapt well and hence result in the leaking of blood from the left ventricle to the left atrium during the systolic phase. The treatment options include MV replacement and repair. In order to develop a bioprosthetic or a tissue engineered mitral valve leaflets that behaves similarly to the native MV, the mechanical properties of the native MV leaflets must be well understood (Grashow et al., 2006). In this study, we aim to characterize the unique viscoelastic properties of mitral valve anterior leaflet by studying the mechanical behavior of the tissue in regards to stress‐relaxation, creep, and tissue failure. Mitral valve anterior leaflets (MVAL) of porcine specimens were obtained from a local abattoir. These specimens were then further dissected in the circumferential direction into a dog‐bone shape samples for mechanical testing at a target load level of 600 grams. The testing protocol for each sample was performed as follows: after preconditioning, leaflet tissue was subjected to (1) stress‐relaxation for 15 minutes, followed by (2) creep for 15 minutes, and finally (3) the sample is ultimately pulled to failure. All testing was performed in a PBS bath using a Test Resources uniaxial testing machine. We observed a normal degree of stress relaxation similar to other types of collagenous tissues (~30% – 50%), but negligible creep. Understanding the unique viscoelastic properties of the native MV leaflets at different loading levels would help to better design bioprosthetics or tissue engineered mitral valves that mimics the natural design and the optimal tissue behavior.Support or Funding InformationThis research was funded by the National Science Foundation Award No. DMR‐1359437 at the Agricultural and Biological Engineering Department at Mississippi State University.Special thanks to Sourav Patnaik and Xiaodan Shi for their contribution to the project and to the UPR‐PRISE Program NIH Grant #R25GM096955 for funding and supporting its students through participation in research experiences during their summer internships
Management of Distal Radius Fractures in Adolescent Patients
Authors: Greig Danielle , Silva Mauricio 
Published: June 2021

Background:
While management recommendations for distal radius fractures in both young and skeletally mature patients have been generally well-established, controversy still exists regarding optimal management in adolescent patients approaching skeletal maturity. Thus, the goal of this review is to analyze relevant literature and provide expert recommendations regarding the management of distal radius fractures in this patient population.

Methods:
A PubMed search was performed to identify literature pertaining to distal radius fractures in adolescent patients, defined as 11 to 14 years in girls and 13 to 15 years in boys. Relevant articles were selected and summarized.

Results:
Distal radius fractures demonstrate significant potential for remodeling of angular deformity and bayonet apposition, even in patients older than 12 years of age. Rotational forearm range of motion and functional outcomes are acceptable with up to 15 degrees of residual angulation. Closed reduction and percutaneous pinning reduces fracture redisplacement but has a high associated complication rate. There is no literature comparing plate versus pin fixation of distal radius fractures in the pediatric population, but in adults plate fixation is associated with higher cost with no improvement in long-term functional outcomes.

Conclusions:
Remodeling can still be expected to occur in adolescent patients, and even with residual deformity functional outcomes after distal radius fractures are excellent. Up to 15 degrees of residual angulation can be accepted before considering operative management. Smooth pins should be considered over plates as first-line operative management for unstable fractures that fail nonoperative treatment.
Proximal Humerus Fractures: What Alignment is Acceptable in Children 10 and Up?
Authors: Shahriar Rajin , Hosseinzadeh Pooya 
Published: June 2021

Background:
Fractures of the proximal humerus in skeletally immature patients are rare, and even rarer still in individuals approaching skeletal maturity. Concepts regarding remodeling potential, amount of deformity and functional demands can guide our treatment decision making, but criteria are poorly defined. The purpose of this manuscript is to discuss the issues and the best available evidence.

Methods:
A search of the English literature was carried out using PubMed to identify papers on the topic of proximal humerus fractures in skeletally immature individuals.

Results:
The literature available on the topic of pediatric proximal humerus fractures is limited, especially regarding fractures in patients approaching skeletal maturity. Certainly, as the remodeling potential decreases and the amount of deformity and functional demand increase, the need for operative treatment increases. The exact tolerances and criteria have not been established. A variety of surgical techniques exist, and have been shown to be helpful.

Conclusions:
Operative treatment may be necessary in individuals approaching skeletal maturity. Concepts discussed in this paper regarding remodeling, amount of deformity and functional demand may help the surgeon to make appropriate treatment decisions. Future prospective comparative studies which are pending will hopefully shed further light on this matter.
When Should Instrumentation to the Pelvis be Considered in Minimally Ambulatory Adolescents With Neuromuscular Scoliosis?
Authors: Douleh Diana G. , Greig Danielle , Thompson Rachel , Garg Sumeet 
Published: June 2021

Introduction:
The goal of neuromuscular scoliosis (NMS) surgery is to improve sitting balance, facilitate daily care, and alleviate pain. In nonambulatory patients, where sitting balance is key, fusion to the pelvis is usually required. However, in minimally ambulatory patients, fusion to the pelvis remains controversial, and there is considerable practice variability in this patient population. The purpose of this study is to evaluate and summarize the available evidence regarding fusion constructs in minimally ambulatory patients with NMS and to provide expert opinion regarding when fusion to the pelvis should be considered.

Methods:
A search of the English literature was performed using PubMed to identify papers pertaining to patients with NMS treated with instrumented posterior spinal fusion. Papers published before 2000, case reports, and level V evidence were excluded.

Results:
The authors identified 8 studies for review. The majority included both nonambulatory and minimally ambulatory patients. Structured review of the literature demonstrated fusion to the pelvis may allow for greater curve and pelvic obliquity correction, but it is also associated with increased blood loss and operative time. There is no evidence that fusing to the pelvis decreases ambulatory status in minimally ambulatory patients.

Conclusions:
In minimally ambulatory patients with NMS, fusion short of the pelvis may be considered in patients with adequate head control without the presence of hip subluxation or dislocation and when pelvic obliquity is <15 degrees. Fusion to the pelvis is recommended in patients who do not meet these criteria.
Fine particulate pollution concentration in Addis Ababa exceeds the WHO guideline value
Authors: Kumie Abera , Worku Alemayehu , Tazu Zelalem , Tefera Worku , Asfaw Araya , Boja Getu , Mekashu Molla , Siraw Dawit , Teferra Solomon , Zacharias Kristin , Patz Jonathan , Samet Jonathan , Berhane Kiros 
Published: June 2021

Background:
Real-time monitoring of fine particulate matter (PM2.5) concentrations and assessing the health impact are limited in Ethiopia. The objective of this study is to describe current levels of PM2.5 air pollution in Addis Ababa and examine temporal patterns and to consider the health impact of current PM2.5 exposure levels.

Methods:
PM2.5 concentrations were measured using a centrally-located Beta Attenuator Monitor (BAM-1022) for 3 years (1 April 2017 to 31 March 2020), with data downloaded biweekly. Deaths attributable to current PM2.5 concentration levels were estimated using the AirQ+ tool. The daily average was estimated using hourly data.

Results:
The daily mean (SD) PM2.5 concentration was 42.4 µg/m3 (15.98). Two daily extremes were observed: morning (high) and afternoon (low). Sundays had the lowest PM2.5 concentration, while Mondays to Thursdays saw a continuous increase; Fridays showed the highest concentration. Seasons showed marked variation, with the highest values during the wet season. Concentration spikes reflected periods of intensive fuel combustion. A total of 502 deaths (4.44%) were attributable to current air pollution levels referenced to the 35 µg/m3 WHO interim target annual level and 2,043 (17.7%) at the WHO 10 µg/m3 annual guideline.

Conclusion:
PM2.5 daily levels were 1.7 times higher than the WHO-recommended 24-hour guideline. The current annual mean PM2.5 concentration results in a substantial burden of attributable deaths compared to an annual mean of 10 µg/m3. The high PM2.5 level and its variability across days and seasons calls for citywide interventions to promote clean air.
Regional Variation of Early-onset Neonatal Group B Streptococcal Disease Prevention Strategies in Mainland China
Authors: Wang Yan , Zhao Yangyu , Zou Liying , Qiao Jie , Benitz William E. 
Published: June 2021

Background:
Prevention strategies can reduce the incidence of early-onset group B Streptococcus (GBS) neonatal sepsis (EOGBS). Rates of GBS colonization and infection vary among regions within China. China has not adopted a unified prevention strategy.

Methods:
To assess strategies to reduce EOGBS in China, models were developed to quantify residual EOGBS rates with intrapartum antibiotic prophylaxis in infants ≥ 35 weeks’ gestation in risk factor-based and antepartum screening-based strategies. Maternal GBS colonization rates and EOGBS incidence in 3 regions of China (A: Xiamen of Fujian province, B: Shanghai and C: Liuzhou of Guangxi province) were estimated from published data.

Results:
Estimates for GBS colonization and attack rates were 21.6%, 11.7% and 6.1% and 1.79, 1.79 and 0.58 per 1000 live births for regions A, B and C, respectively. Modeling predicted that strategies including screening cultures beginning at 36 weeks’ gestation and intrapartum antibiotic prophylaxis in 90% of eligible parturients could reduce EOGBS incidence to 0.44, 0.50 and 0.16 per 1000 live births in these regions. In region C, the expected EOGBS rate could be reduced to 0.28 per 1000 using a risk factor-based strategy.

Conclusions:
Different strategies for preventing EOGBS may be needed in different regions of mainland China. Screening strategies may be most appropriate in regions with higher attack rates, even with moderate levels of maternal GBS colonization. In areas with low attack rates, risk factor strategies that reduce morbidity by at least one-third may suffice.
Intrinsic attention to pain is associated with a pronociceptive phenotype
Authors: Adams Greig , Harrison Richard , Gandhi Wiebke , van Reekum Carien M. , Salomons Tim V. 
Published: June 2021

Abstract

Introduction:
Evidence suggests that attention to pain is a product of both incoming sensory signals and cognitive evaluation of a stimulus. Intrinsic attention to pain (IAP) is a measure that captures an individual's natural tendency to attend to a painful stimulus and may be important in understanding why pain disrupts cognitive functioning in some individuals more than others.

Objective:
In this study, we explored the extent to which IAP was associated with the modulation of incoming sensory signals characteristic of a pronociceptive phenotype: temporal summation (TS) and conditioned pain modulation (CPM).

Method:
44 healthy participants (23 female; Mage=23.57, S.D.=5.50) were assessed on IAP, TS and CPM.

Results:
We found that IAP was positively correlated with TS and CPM. A regression model showed that TS and CPM explained 39% of the variance in IAP scores. Both mechanisms seem to contribute independently to the propensity to attend to pain.

Conclusion:
These findings highlight that modulatory mechanisms at the spinal/supraspinal level exert a strong influence on an individual's ability to disengage from pain.
Best practices for virtual care to support youth with chronic pain and their families: a rapid systematic review to inform health care and policy during COVID-19 and beyond
Authors: Birnie Kathryn A. , Killackey Tieghan , Stinson Jennifer , Noel Melanie , Lorenzetti Diane L. , Marianayagam Justina , Jordan Isabel , Jordan Evie , Neville Alexandra , Pavlova Maria , Campbell Fiona , Lalloo Chitra 
Published: June 2021

Abstract
The COVID-19 pandemic has acutely challenged health systems and catalyzed the need for widescale virtual care and digital solutions across all areas of health, including pediatric chronic pain. The objective of this rapid systematic review was to identify recommendations, guidelines, and/or best practices for using virtual care to support youth with chronic pain and their families (CRD42020184498). MEDLINE, CINAHL, Embase, APA PsychINFO, and Web of Science were searched the week of May 25, 2020, for English language peer-reviewed articles published since 2010 that (1) discussed children and adolescents aged <18 years reporting any type of chronic pain (ie, pain lasting >3 months); (2) focused on any type of virtual care (eg, telephone, telehealth, telemedicine, mHealth, eHealth, online, or digital); and (3) reported on guidelines, best practices, considerations, or recommendations for virtual care. Abstract and full text screening and data extraction were performed in duplicate. Meta-ethnography was used to synthesize concepts across articles. Of 4161 unique records screened, 16 were included addressing diverse virtual care and pediatric chronic pain conditions. Four key themes were identified: (1) opportunities to better leverage virtual care, (2) direct effective implementation of virtual care, (3) selection of virtual care platforms, and (4) gaps in need of further consideration when using virtual care to support youth with chronic pain and their families. No existing guidelines for virtual care for pediatric chronic pain were identified; however, best practices for virtual care were identified and should be used by health professionals, decision makers, and policymakers in implementing virtual care.
Scheduling of energy storage
Authors: Zachary Stan , Tindemans Simon H. , Evans Michael P. , Cruise James R. , Angeli David 
Published: June 2021

The increasing reliance on renewable energy generation means that storage may well play a much greater role in the balancing of future electricity systems. We show how heterogeneous stores, differing in capacity and rate constraints, may be optimally, or nearly optimally, scheduled to assist in such balancing, with the aim of minimizing the total imbalance (unserved energy) over any given period of time. It further turns out that in many cases the optimal policies are such that the optimal decision at each point in time is independent of the future evolution of the supply–demand balance in the system, so that these policies remain optimal in a stochastic environment.This article is part of the theme issue ‘The mathematics of energy systems’.
Temporal association of reduced serum vitamin D with COVID-19 infection: A single-institution case-control and historical cohort study
Authors: Gupta Diviya , Menon Sahit , Criqui Michael H. , Sun Bryan K. 
Published: June 2021

AbstractObjectivesVitamin D supplementation has been proposed for the prevention and treatment of COVID-19, but the relationship between the two is inconclusive: Reduced serum vitamin D may predispose to COVID-19, but it may also be a secondary consequence of infection. The objective of this study was to assess the temporal association between serum vitamin D levels and COVID-19.DesignA single-institution case-control study and a historical cohort studySettingUniversity of California San Diego (UCSD) Health System in San Diego, CaliforniaParticipantsPatients testing positive for COVID-19 from January 1, 2020 to September 30, 2020 with serum 25-hydroxy-vitamin D (25(OH)D) measured within 180 days of diagnosis. Patients were separated based on whether 25(OH)D was measured before (n=107; “pre-diagnosis”) or after (n=203; “post-diagnosis”) COVID-19 diagnosis. Subjects with 25(OH)D assessments prior to COVID-19 diagnosis were evaluated using a case-control study design, while subjects with 25(OH)D measured after COVID-19 diagnosis were analyzed with a historical cohort study design.Primary and Secondary Outcome MeasuresIn the pre-diagnosis study, a conditional logistic regression was performed using COVID-19 infection status as the binary dependent variable. In the post-diagnosis study, an ordinary least squares regression was performed using serum 25(OH)D levels as the continuous dependent variable.ResultsSerum 25(OH)D levels were not associated with the odds of subsequently testing positive for COVID-19 (OR 1.00, 95% CI: 0.98 to 1.02, p = 0.982). However, COVID-19 positive individuals had serum 25(OH)D measurements that were lower by 2.70 ng/mL (95% CI: −5.19 to −0.20, p = 0.034) compared to controls.ConclusionsIn our study population, serum 25(OH)D levels were not associated with risk of testing positive for COVID-19 but were reduced in subjects after being diagnosed with COVID-19 infection. These results raise the possibility that reduced serum 25(OH)D may be a consequence and not a cause of COVID-19 infection.
Early Epidemiological Evidence of Public Health Value of WA Notify, a Smartphone-based Exposure Notification Tool: Modeling COVID-19 Cases Averted in Washington State
Authors: Segal Courtney , Zhang Zhehao , Karras Bryant T , Revere Debra , Zane Gregory , Baseman Janet G 
Published: June 2021

AbstractBackgroundSecure and anonymous smartphone-based exposure notification tools are recently developed public health interventions that aim to reduce COVID-19 transmission and supplement traditional public health suriveillance. We assessed the impact of Washington State’s exposure notification tool, WA Notify, in mitigating the spread of COVID-19 during its first four months of implementation.MethodsDue to the constraints of privacy-preservation, aggregate metrics and disparate data sources were utilized to estimate the number of COVID-19 cases averted based on a modelling approach adapted from Wymant et al (2021) using the following parameters: number of notifications generated; the probability that a notified individual goes on to become a case; expected fraction of transmissions preventable by strict quarantine after notification; actual adherence to quarantine; and expected size of the full transmission chain if a contact had not been notified.ResultsThe model was run on a range of secondary attack rates (5.1%-13.706%) and quarantine effectiveness (53% and 64%). Assuming a 12.085% secondary attack rate and 53% quarantine effectiveness, the model shows that 5,500 cases (central 95% range of sensitivity analyses 2,800-8,200) were averted statewide during the first four months of its implementation. Based on an estimated COVID-19 case fatality of 1.4%, WA Notify saved 40-115 lives during the study period.ConclusionsThese findings demonstrate the value of exposure notification tools as a novel public health intervention to mitigate the spread of COVID-19 in the U.S. As new variants emerge and non-essential travel bans are lifted, exposure notification tools may continue to play a valuable role in limiting the spread of COVID-19.
Pre-infection 25-hydroxyvitamin D3 levels and association with severity of COVID-19 illness
Authors: Dror Amiel A. , Morozov Nicole G. , Daoud Amani , Namir Yoav , Orly Yakir , Shachar Yair , Lifshitz Mark , Segal Ella , Fischer Lior , Mizrachi Matti , Eisenbach Netanel , Rayan Doaa , Gruber Maayan , Bashkin Amir , Kaykov Edward , Barhoum Masad , Edelstein Michael , Sela Eyal 
Published: June 2021

AbstractObjectiveStudies have demonstrated a potential link between low vitamin D levels and both an increased risk of infection with SARS-CoV-2 and poorer clinical outcomes but have not established temporality. This retrospective study examined if, and to what degree, a relationship exists between pre-infection serum vitamin D levels and disease severity and mortality of SARS-CoV-19.Design and patientsThe records of individuals admitted between April 7th, 2020 and February 4th, 2021 to the Galilee Medical Center (GMC) in Nahariya, Israel with positive polymerase chain reaction (PCR) tests for SARS-CoV-2 were searched for vitamin D (VitD) levels measured 14 to 730 days prior to the positive PCR test.MeasurementsPatients admitted to GMC with COVID-19 were categorized according to disease severity and VitD level. Association between pre-infection VitD levels and COVID-19 severity was ascertained utilizing a multivariate regression analysis.ResultsOf 1176 patients admitted, 253 had VitD levels prior to COVID-19 infection. Compared with mildly or moderately diseased patients, those with severe or critical COVID-19 disease were more likely to have pre-infection vitamin D deficiency of less than 20 ng/mL (OR=14.30, 95%, 4.01-50.9; p < .001); be older (OR=1.039 for each year, 95% CI for OR, 1.017-1.061; p< .01), and have diabetes (OR=2.031, 95% CI for OR, 1.04-3.36; p= 0.038). Vitamin D deficiency was associated with higher rates of mortality (p<0.001) and comorbidities including COPD (p=0.006), diabetes (p=0.026), and hypertension (p=0.016).ConclusionsAmong hospitalized COVID-19 patients, pre-infection deficiency of vitamin D was associated with increased disease severity and mortality.