bluuebunny/crossref_metadata_2025 huggingface dataset:
Does the use of alternative predictor methods reduce subgroup differences? It depends on the construct
Authors: Arthur Winfred , Keiser Nathanael L. , Atoba Olabisi A. , Cho Inchul , Edwards Bryan D.
Published: September 2020

Using a bare‐bones meta‐analysis, the present study examined the effectiveness of the use of commonly considered alternative predictor methods as a means to reduce subgroup differences (i.e., the method‐change approach), taking into account the constructs assessed. With a focus on assessment centers, interviews, situational judgment tests, and work samples as alternative methods, the results indicated that consonant with the construct/method distinction, the effectiveness of a method in reducing subgroup differences is a function of the constructs assessed. Specifically, there are larger White‐African American subgroup differences that favor Whites for cognitive constructs on paper‐and‐pencil tests compared to the alternative methods; and most notably, the opposite result was obtained for noncognitive constructs such that, compared to paper‐and‐pencil assessments, substantially larger White‐African American subgroup differences were observed for alternative methods. A similar pattern of results was obtained for White‐Hispanic comparisons, albeit based on a smaller number of data points. In summary, the study's results indicate that the ubiquitously asserted effectiveness of the method‐change approach for reducing subgroup differences is overstated, with said effectiveness depending on the construct assessed.
A concerted research effort to advance the hydrological understanding of tropical páramos
Authors: Correa Alicia , Ochoa‐Tocachi Boris F , Birkel Christian , Ochoa‐Sánchez Ana , Zogheib Charles , Tovar Carolina , Buytaert Wouter
Published: September 2020

Páramos, a neotropical alpine grassland‐peatland biome of the northern Andes and Central America, play an essential role in regional and global cycles of water, carbon, and nutrients. They act as water towers, delivering water and ecosystem services from the high mountains down to the Pacific, Caribbean, and Amazon regions. Páramos are also widely recognized as a biodiversity and climate change hot spots, yet they are threatened by anthropogenic activities and environmental changes. Despite their importance for water security and carbon storage, and their vulnerability to human activities, only three decades ago, páramos were severely understudied. Increasing awareness of the need for hydrological evidence to guide sustainable management of páramos prompted action for generating data and for filling long‐standing knowledge gaps. This has led to a remarkably successful increase in scientific knowledge, induced by a strong interaction between the scientific, policy, and (local) management communities. A combination of well‐established and innovative approaches has been applied to data collection, processing, and analysis. In this review, we provide a short overview of the historical development of research and state of knowledge of the hydrometeorology, flux dynamics, anthropogenic impacts, and the influence of extreme events in páramos. We then present emerging technologies for hydrology and water resources research and management applied to páramos. We discuss how converging science and policy efforts have leveraged traditional and new observational techniques to generate an evidence base that can support the sustainable management of páramos. We conclude that this co‐evolution of science and policy was able to successfully cover different spatial and temporal scales. Lastly, we outline future research directions to showcase how sustainable long‐term data collection can foster the responsible conservation of páramos water towers.
Tyrosine‐derived polycarbonate nerve guidance tubes elicit proregenerative extracellular matrix deposition when used to bridge segmental nerve defects in swine
Authors: Burrell Justin C. , Bhatnagar Divya , Brown Dan P. , Murthy N. Sanjeeva , Dutton John , Browne Kevin D. , Laimo Franco A. , Ali Zarina S. , Rosen Joseph M. , Kaplan Hilton M. , Kohn Joachim , Cullen D. Kacy
Published: September 2020

Promising biomaterials should be tested in appropriate large animal models that recapitulate human inflammatory and regenerative responses. Previous studies have shown tyrosine‐derived polycarbonates (TyrPC) are versatile biomaterials with a wide range of applications across multiple disciplines. The library of TyrPC has been well studied and consists of thousands of polymer compositions with tunable mechanical characteristics and degradation and resorption rates that are useful for nerve guidance tubes (NGTs). NGTs made of different TyrPCs have been used in segmental nerve defect models in small animals. The current study is an extension of this work and evaluates NGTs made using two different TyrPC compositions in a 1 cm porcine peripheral nerve repair model. We first evaluated a nondegradable TyrPC formulation, demonstrating proof‐of‐concept chronic regenerative efficacy up to 6 months with similar nerve/muscle electrophysiology and morphometry to the autograft repair control. Next, we characterized the acute regenerative response using a degradable TyrPC formulation. After 2 weeks in vivo, TyrPC NGT promoted greater deposition of pro‐regenerative extracellular matrix (ECM) constituents (in particular collagen I, collagen III, collagen IV, laminin, and fibronectin) compared to commercially available collagen‐based NGTs. This corresponded with dense Schwann cell infiltration and axon extension across the lumen. These findings confirmed results reported previously in a mouse model and reveal that TyrPC NGTs were well tolerated in swine and facilitated host axon regeneration and Schwann cell infiltration in the acute phase across segmental defects ‐ likely by eliciting a favorable neurotrophic ECM milieu. This regenerative response ultimately can contribute to functional recovery.
Comprehensive laboratory reference intervals for routine biochemical markers and pro‐oxidant‐antioxidant balance (PAB) in male adults
Authors: Ghazizadeh Hamideh , Kathryn Bohn Mary , Ghaffarian Zirak Roshanak , Kamel Khodabandeh Atieh , Zare‐Feyzabadi Reza , Saberi‐Karimian Maryam , Timar Ameneh , Jaberi Naghmeh , Mohammadi‐Bajgiran Maryam , Sharifan Payam , Tayefi Maryam , Silakhori Samaneh , Emamian Marzieh , Oladi Mohammad Reza , Esmaily Habibollah , Ferns Gordon A. , Adeli Khosrow , Ghayour‐Mobarhan Majid
Published: September 2020

Background

Reference values of biochemical markers are influenced by various parameters including age, sex, region, and lifestyle. Hence, we aimed to determine age‐ and BMI‐specific reference intervals (RIs) for important clinical biomarkers in a healthy adult male population from northeastern Iran. This is also the first study to investigate reference values for pro‐oxidant‐antioxidant balance (PAB).

Methods

Seven hundred and twenty (720) healthy men, aged 20‐60 years, were recruited from Sarakhs in the northeast region of Iran. Reference values for lipid profiles (total cholesterol, triglyceride, HDL‐C and LDL‐C), fasting blood glucose, inflammatory factors (hs‐CRP and PAB), minerals (zinc and copper), uric acid, and blood pressure were measured and statistically analyzed to establish accurate age‐ and BMI‐specific RIs in alignment with CLSI Ep28‐A3 guidelines.

Results

RIs for lipid profiles, inflammatory factors, minerals, and uric acid required no age partitioning with the exception of fasting blood glucose and blood pressure, which demonstrated significantly higher values in subjects aged 50 years and older. Among these biomarkers, only uric acid, blood pressure, and triglycerides demonstrated statistically significant increases in reference value concentrations with increasing BMI.

Conclusion

In this study, age‐ and BMI‐specific RIs for several biochemical markers were determined in healthy adult Iranian men. Partitioning by age and BMI was only required for a few analytes with most demonstrating no statistically significant changes with these covariates. These data can be useful to monitor various diseases in male adults with varying BMI in this region and others.
Increased body mass index is associated with decreased imaging quality of point‐of‐care abdominal aortic ultrasonography
Authors: Jeeji Archana K. , Ekstein Samuel F. , Ifelayo Oluwatomilona I. , Oyemade Kafayat A. , Tawfic Sarah S. , Hyde Robert J , Laughlin Michael J. , Lohse Christine M. , Mullan Aidan F. , Kummer Tobias , Bellamkonda Venkatesh R.
Published: September 2020

Background

Given that abdominal aorta is a retroperitoneal structure, increased body mass index (BMI) may have an adverse effect upon the quality of aortic ultrasonographic imaging.

Purpose

To assess the hypothesis that increased BMI is associated with worsening point‐of‐care abdominal aortic ultrasonographic image quality.

Methods

This is a retrospective single‐center study of point‐of‐care abdominal aortic ultrasound examinations performed in an academic emergency department (ED) with fellowship‐trained emergency ultrasonography faculty performing quality assurance review.

Results

Mean ± SD BMI was 27.4 ± 6.2, among the 221 included records. The overall quality rating decreased as BMI increased (correlation coefficient − 0.24; P < .001) and this persisted after adjustment for age and sex (P < .001). Although BMI was higher on average in the records that were of insufficient quality for clinical decisions when compared with those of sufficient quality (mean BMI 28.7 vs 27.0), this did not reach statistical significance in a univariable setting (P = .11) or after adjusting for age and sex (P = .14).

Conclusion

This study data shows a decrease in point‐of‐care abdominal aorta ultrasound imaging quality as BMI increases, though this difference did not result in a statistically significant impairment in achieving the minimum quality for clinical decisions. This finding may help ameliorate some clinician concerns about ultrasonography for patients with high BMI.
Artemia salina: A microcrustacean to assess engineered nanoparticles toxicity
Authors: Pecoraro Roberta , Scalisi Elena Maria , Messina Giuseppina , Fragalà Giuseppe , Ignoto Sara , Salvaggio Antonio , Zimbone Massimo , Impellizzeri Giuliana , Brundo Maria Violetta
Published: September 2020

The focus of this work was to investigate the toxicity of different metal nanoparticles (gold nanoparticles [AuNPs], silver nanoparticles [AgNPs], titanium dioxide nanoparticles [TiO2NPs]) on brine shrimpArtemia salina. We investigated if nanoparticles could have an influence on hatching of cysts and on mortality of larvae. Larvae (also called nauplii) and cysts were exposed to NPs for 24 hr in artificial seawater on microplates. At the end of the test, we assessed the endpoint (immobility/death) for the larvae by a stereomicroscope. Nauplii that appeared completely motionless, were counted as dead, and the percentages of mortality were calculated for each treatment. Instead for the cysts, the percentages of not‐hatched nauplii for each concentration considered were calculated by counting the number of whole cysts. Currently, nanoparticles toxicity has been investigated in several research; in our study we highlighted the nontoxicity of TiO2NPs onA. salinanauplii as shown by low percentages of immobilization and on cysts because TiO2NPs do not affect their hatching. Despite AuNPs exerted toxic effects on hatching, they did not affect larvae development as well as TiO2NPs. Otherwise, AgNPs induced mortality of the larvae and inhibited cysts hatching.
Identifying groups of people with similar sociobehavioural characteristics in Malawi to inform HIV interventions: a latent class analysis
Authors: Merzouki Aziza , Styles Amanda , Estill Janne , Orel Erol , Baranczuk Zofia , Petrie Karen , Keiser Olivia
Published: September 2020

Introduction

Within many sub‐Saharan African countries including Malawi, HIV prevalence varies widely between regions. This variability may be related to the distribution of population groups with specific sociobehavioural characteristics that influence the transmission of HIV and the uptake of prevention. In this study, we intended to identify groups of people in Malawi with similar risk profiles.

Methods

We used data from the Demographic and Health Survey in Malawi (2015 to 2016), and stratified the analysis by sex. We considered demographic, socio‐behavioural and HIV‐related variables. Using Latent Class Analysis (LCA), we identified groups of people sharing common sociobehavioural characteristics. The optimal number of classes (groups) was selected based on the Bayesian information criterion. We compared the proportions of individuals belonging to the different groups across the three regions and 28 districts of Malawi.

Results

We found nine groups of women and six groups of men. Most women in the groups with highest risk of being HIV positive were living in female‐headed households and were formerly married or in a union. Among men, older men had the highest risk of being HIV positive, followed by young (20 to 25) single men. Generally, low HIV testing uptake correlated with lower risk of having HIV. However, rural adolescent girls had a low probability of being tested (48.7%) despite a relatively high HIV prevalence. Urban districts and the Southern region had a higher percentage of high‐prevalence and less tested groups of individuals than other areas.

Conclusions

LCA is an efficient method to find groups of people sharing common HIV risk profiles, identify particularly vulnerable sub‐populations, and plan targeted interventions focusing on these groups. Tailored support, prevention and HIV testing programmes should focus particularly on female household heads, adolescent girls living in rural areas, older married men and young men who have never been married.
A bioinformatic prediction of antigen presentation from SARS‐CoV‐2 spike protein revealed a theoretical correlation of HLA‐DRB1*01 with COVID‐19 fatality in Mexican population: An ecological approach
Authors: Romero‐López José Pablo , Carnalla‐Cortés Martha , Pacheco‐Olvera Diana L. , Ocampo‐Godínez Juan Moisés , Oliva‐Ramírez Jacqueline , Moreno‐Manjón Julia , Bernal‐Alferes Brian , López‐Olmedo Nancy , García‐Latorre Ethel , Domínguez‐López María Lilia , Reyes‐Sandoval Arturo , Jiménez‐Zamudio Luis
Published: September 2020

SARS‐CoV‐2 infection is causing a pandemic disease that is reflected in challenging public health problems worldwide. Human leukocyte antigen (HLA)‐based epitope prediction and its association with disease outcomes provide an important base for treatment design. A bioinformatic prediction of T cell epitopes and their restricted HLA Class I and II alleles was performed to obtain immunogenic epitopes and HLA alleles from the spike protein of the severe acute respiratory syndrome coronavirus 2 virus. Also, a correlation with the predicted fatality rate of hospitalized patients in 28 states of Mexico was done. Here, we describe a set of 10 highly immunogenic epitopes, together with different HLA alleles that can efficiently present these epitopes to T cells. Most of these epitopes are located within the S1 subunit of the spike protein, suggesting that this area is highly immunogenic. A statistical negative correlation was found between the frequency of HLA‐DRB1*01 and the fatality rate in hospitalized patients in Mexico.
Seroprevalence of hepatitis A virus infection in Central‐West of Tunisia
Authors: Ayouni Kaouther , Kharroubi Ghassen , Mallekh Rym , Hammami Walid , Marouani Ridha , Mhamdi Moncef , Ben Salah Afif , Triki Henda , Bettaieb Jihène
Published: September 2020

Hepatitis A infections still represent a major global health concern. During the past years, a transition pattern of the hepatitis A epidemiology was noted in many parts of the world. In Tunisia, there is not a recent survey on age‐specific hepatitis A virus seroprevalence. This study aimed to investigate the seroprevalence of hepatitis A virus infection in Central‐West Tunisia, representative of regions with lowest socioeconomic level in the country, before vaccine implementation. Sera obtained from the blood samples of subjects were screened for the detection of hepatitis A virus. The seroprevalence was evaluated by detection of total antibodies to hepatitis A virus using commercially available immunoassay kits. A total of 1379 subjects, aged 5–75 years (mean age: 29.0 ± 17.3 years) were studied. The global anti‐hepatitis A virus seroplevalence was 84.7% (95% confidence interval: [82.6–86.5]). A higher hepatitis A virus seroprevalence was showed in subjects aged 10–14 years compared to those aged less than 10 years (50.0% vs. 31.0%). In subjects aged 20–29 years, a rapid increase in the hepatitis A virus prevalence was noted; it reached 97.0%. The seroprevalence of anti‐hepatitis A virus differed by zone of residence (81.1% in rural area vs. 72.4% in urban area, p = .005) and increased significantly with lower level of education (p = .019). There was no statistical significant seroprevalence difference between male and female: 84.2% versus 85.2%, respectively. Our study confirm the transition pattern of the hepatitis A virus endemicity in Tunisia from high to intermediate and provide an evaluation of the hepatitis A virus epidemiological situation before vaccine implementation.
Retarded decline of the share of SARS‐CoV‐2‐positive children in North Rhine‐Westphalia, Germany
Authors: Häusler Martin , van Helden Josef , Kleines Michael
Published: September 2020

Knowledge on the mechanisms of viral spread, of time‐related changes, and age‐specific factors of severe acute respiratory syndrome coronavirus 2 infections is important to develop recommendations aimed at controlling the pandemic. In this context, longitudinal data on proportions of positive results in different age groups are rare. Data on total positive counts and on shares of positive counts deriving from a private (MVZ) and a University (RWTH) laboratory were analyzed retrospectively and compared with public data on total positive counts of the Robert Koch Institute (RKI). Data were covered for Weeks 9–24 of the year 2020 and all patient ages. Total positive counts were lower in children compared to adults. Proportions of children and adults tested positive were 3%–5% and 5%–7%, respectively. RKI and MVZ data showed similar time‐related patterns. Patients of 20–60 years of age did account for the initial virus spread (maximum infection rates at Weeks 9–11). Thereafter, infection rates decreased in older patients whereas children did not show a comparable time‐related decrease. Pediatric data generated in outpatient settings and hospitals differed markedly which should be considered in further studies. In summary, compared with adults children are less affected by severe acute respiratory syndrome coronavirus 2 infections and are unlikely to account for the initial viral spread. However, children show sustained viral activity and may serve as a viral reservoir.
Sleep problems in Rett syndrome animal models: A systematic review
Authors: Zhang Xinyan , Lin Jian‐Sheng , Spruyt Karen
Published: September 2020

Due to the discovery of Rett Syndrome (RTT) genetic mutations, animal models have been developed. Sleep research in RTT animal models may unravel novel neural mechanisms for this severe neurodevelopmental heritable rare disease. In this systematic literature review we summarize the findings on sleep research of 13 studies in animal models of RTT. We found disturbed efficacy and continuity of sleep in all genetically mutated models of mice, cynomolgus monkeys, and Drosophila. Models presented highly fragmented sleep with distinct differences in 24‐hr sleep/wake cyclicity and circadian arrhythmicity. Overall, animal models mimic sleep complaints reported in individuals with RTT. However, contrary to human studies, in mutant mice, attenuated sleep delta waves, and sleep apneas in non‐rapid eye movement sleep were reported. Future studies may focus on sleep structure and EEG alterations, potential central mechanisms involved in sleep fragmentation and the occurrence of sleep apnea across different sleep stages. Given that locomotor dysfunction is characteristic of individuals with RTT, studies may consider to integrate its potential impact on the behavioral analysis of sleep.
Monolithic full‐color microdisplay using patterned quantum dot photoresist on dual‐wavelength LED epilayers
Authors: Li Peian , Zhang Xu , Li Yangfeng , Qi Longheng , Tang Chak Wah , Lau Kei May
Published: September 2020

A passive‐matrix monolithic full‐color InGaN light emitting diode (LED) microdisplay with 40 × 40 full‐color pixels is demonstrated. Each full‐color pixel consists of red, green, and blue (RGB) subpixels that have a pitch size of 40 μm × 120 μm. The full‐color microdisplay is monolithically fabricated on blue/green dual‐wavelength LED epilayers, using red quantum dot photoresist as a color converter. Pure RGB emission and a wide color gamut are achieved, as shown by electroluminescence spectra. Full‐color patterns with controllable grayscale and color mixing can be clearly rendered driven by a full‐color microdisplay controller, indicating tremendous potential of this novel approach for full‐color LED microdisplays in the future.
Resting Energy Expenditure, Fetal Biometric Parameters by Ultrasound, and Birthweight in Chinese Pregnant Women With Gestational Diabetes Mellitus
Authors: Liu Fang , Quan Haiying , Lai Yaping , Gu Xiaoning , Liu Dongmei , Yang Min
Published: September 2020

Objectives

To explore the relationships between resting energy expenditure (REE) according to indirect calorimetry, fetal biometric parameters by ultrasound, and birthweight in gestational diabetes mellitus (GDM).

Methods

Sixty‐five women with GDM and 60 in the control group were enrolled. The REE, birthweight, and fetal biometric parameters according to ultrasound, including biparietal diameter, head circumference, abdominal circumference (AC), and femur length, were measured.

Results

The AC at 29 to 32 weeks and 37 to 40 weeks was larger in the GDM than in the control group (P < 0.01), birthweight was higher in the GDM than in the control group (P < 0.01), and women in the GDM group had higher REE than those in the control group at all stages of pregnancy (P < 0.01). In the control group, all fetal biometric parameters were correlated with birthweight at 37 to 40 weeks (r= 0.418, 0.678, 0.741, and 0.635 for biparietal diameter, head circumference, AC, and femur length, respectively,P < 0.05); however, in the GDM group, only AC was correlated with birthweight at 37 to 40 weeks (r= 0.707;P < 0.05). In the GDM group, REE was correlated with birthweight at all three stages of pregnancy (r= 0.369, 0.381, and 0.446 for 21 to 24, 29 to 32, and 37 to 40 weeks, respectively,P < 0.05), and REE was correlated with AC at 37 to 40 weeks (r= 0.431;P < 0.05).

Conclusions

REE is correlated with birthweight in women with GDM from the middle to the end of pregnancy. REE by indirect calorimetry might be potential index for medical nutrition therapy in GDM.
Modified Posterior Pedicle Middle Turbinate Flap: An Additional Option for Skull Base Resurfacing
Authors: Pistochini Andrea , Russo Federico , Coden Elisa , Sileo Giorgio , Battaglia Paolo , Bignami Maurizio , Volpi Luca , Castelnuovo Paolo
Published: September 2020

Objectives/Hypothesis

Although the Hadad‐Bassagusteguy flap represents the first choice for middle and posterior skull base reconstruction and coverage of exposed bony areas, in some cases it is unavailable. The aim of this study is to describe, as an alternative option in selected cases, a modified posterior pedicle middle turbinate flap (mPPMTF) extended to the lacrimal area. Anatomical features, step‐by‐step harvesting technique, and surgical applications are presented.

Study design

Anatomic dissection study and case report.

Methods

Four mPPMTFs were raised in two fresh‐frozen cadaver heads. A study of the vascular supply and measurements of length, width, and area of the flap were performed. The ability of the flap to cover the ventral skull base, particularly the upper clivus area, was tested. A clinical case in which an mPPMTF was used for clivus resurfacing after osteoradionecrosis is reported.

Results

The vascular supply of the mPPMTF was identified as the middle turbinate branch of the sphenopalatine artery. The flap had a mean length of 6.92 cm, mean maximum width of 1.08 cm, and mean total area of 5.33 cm2. The flap was able to reach the upper clivus, with a clival coverage ratio of 70.66%. In the clinical case, good surgical outcomes were observed, with accelerated re‐epithelization without complications.

Conclusions

The mPPMTF represents an alternative to the Hadad‐Bassagusteguy flap for posterior cranial fossa and nasopharynx resurfacing. The main drawbacks are its technically demanding and time‐consuming harvesting.

Level of Evidence

4 Laryngoscope, 131:E767–E774, 2021
Purposes of peer review: A qualitative study of stakeholder expectations and perceptions
Authors: Severin Anna , Chataway Joanna
Published: September 2020

Stakeholders might have diverging or conflicting expectations about the functions that peer review should fulfil. We aimed to explore how stakeholder groups perceive peer review and what they expect from it. We conducted qualitative focus group workshops with early‐, mid‐, and senior career scholars, editors, and publishers. We recruited participants following a purposive maximum variation sampling approach. To identify purposes of peer review, we conducted a thematic analysis. Stakeholders expected peer review (1) to assess the contributions of a manuscript, (2) to conduct quality control, (3) to improve manuscripts, (4) to assess the suitability of manuscripts for a journal, (5) to provide a decision‐making tool for editors, (6) to provide feedback by peers, (7) to curate a community, and (8) to provide a seal of accreditation for published articles. Stakeholders with different roles and tasks in the peer review process differed in the value they attached to the functions of peer review. Early‐ and mid‐career researchers valued social and feedback functions of peer review, while senior career researchers and editors expected it to instead perform a technical assessment of manuscripts and serve as a decision‐making tool. Publishers expected peer review to assess the suitability of manuscripts for their journals and to provide a seal of accreditation. This revealed a potential tension between functions of peer review. Stakeholder expectations are shaped by how stakeholders perceive their own roles both in relation to the peer review process and within their scientific community.
The cathodic protection potential criteria: Evaluation of the evidence
Authors: Googan Chris
Published: September 2020

Recent publications have ascribed the mechanism of cathodic protection (CP) in soils to the development of passivity at the steel surface. This view has, in turn, prompted discussion on the need to re‐evaluate the long‐established criteria for protection. This paper presents a contribution to that discussion. It advances, or rather it restates, the proposition that neither immunity nor passivity is necessarily relevant. It argues that protection is simply a consequence of a potential‐driven lowering of the anodic dissolution rate. However, it also emerges that elucidating any mechanism convincingly requires dependable field or laboratory data on the very low corrosion rates occurring on cathodically polarised specimens. A critical review of published data highlights a lack of reliability in this area.
Mergers, executive compensation and firm performance: The case of Africa
Authors: Amewu Godfred , Paul Alagidede Imhotep
Published: September 2020

This study examines the impact of executive compensation on firm performance after successful mergers and acquisitions (M&A) in Africa between 2005 and 2016. Using accounting and financial performance measures and controlling for firm, deal and corporate governance factors, we show that executive compensation induced by M&A in Africa negatively affect the performance of listed firms. There is also evidence to support the impact of firm size, deal size, target destination, foreign ownership, diversification, outside board representation and executive ownership on the pay‐performance nexus. Besides, corporate governance factors in Africa, generally, worsen firm performance, especially for cash and total pay.
Numerical simulation for the mixed convective flow of non‐Newtonian fluid with activation energy and entropy generation
Authors: Ijaz Khan Muhammad , Alzahrani Faris
Published: September 2020

Here, mathematical modeling is performed for the nonlinear mixed convection in dissipative convective flow of micropolar fluid towards a stretched surface. Mixed convection occurs when both forced and natural convection mechanisms act together. Mixed convection problems are categorized by Grashof number. This is also addressed as situations where both buoyant and pressure forces interact. Slip condition is considered at the boundary for the velocity. Magnetohydrodynamics (MHD) fluid is considered. Novel features of nanofluids like Brownian motion and thermophoresis diffusions are further addressed. Convective condition is imposed at the stretched boundary. Concentration of material particles is discussed with activation energy. Nonlinear partial differential equations are converted into ordinary ones via appropriate similarity transformations. The velocity, temperature, concentration, skin friction, Nusselt number, and entropy generation are discussed numerically with the help of built‐in‐shooting method. Our obtained outcomes show that the velocity of material particles reduces against larger slip parameter and micropolar parameter. Temperature enhances for larger thermal Biot and Eckert numbers. Concentration of fluid particles is more versus solutal Biot number and activation energy parameter. Furthermore, entropy rate increases for higher values of micropolar fluid parameter and activation energy parameter while it declines against slip parameter.
A 3D hybrid‐shot spiral sequence for hyperpolarized imaging
Authors: Tyler Andrew , Lau Justin Y. C. , Ball Vicky , Timm Kerstin N. , Zhou Tony , Tyler Damian J. , Miller Jack J.
Published: September 2020

Purpose

Hyperpolarized imaging experiments have conflicting requirements of high spatial, temporal, and spectral resolution. Spectral‐spatial RF excitation has been shown to form an attractive magnetization‐efficient method for hyperpolarized imaging, but the optimum readout strategy is not yet known.

Methods

In this work, we propose a novel 3D hybrid‐shot spiral sequence which features two constant density regions that permit the retrospective reconstruction of either high spatial or high temporal resolution images post hoc, (adaptive spatiotemporal imaging) allowing greater flexibility in acquisition and reconstruction.

Results

We have implemented this sequence, both via simulation and on a preclinical scanner, to demonstrate its feasibility, in both a

phantom and with hyperpolarized

pyruvate in vivo.

Conclusions

This sequence forms an attractive method for acquiring hyperpolarized imaging datasets, providing adaptive spatiotemporal imaging to ameliorate the conflict of spatial and temporal resolution, with significant potential for clinical translation.
Multispecies Fish Passage Evaluation at a Rock-Ramp Fishway in a Colorado Transition Zone Stream
Authors: Richer Eric E. , Fetherman Eric R. , Krone Elizabeth A. , Wright F. Boyd , Kondratieff Matt C.
Published: September 2020

Stream habitat fragmentation caused by manmade structures is ubiquitous in Colorado, creating a need for passage solutions that accommodate multiple fish species. This study tested the effectiveness of a rock-ramp fishway for passing nine fish species with a range of swimming abilities. The target species for the fishway design included Brassy Minnow Hybognathus hankinsoni (weakest swimming), Longnose Dace Rhinichthys cataractae, Longnose Sucker Catostomus catostomus, and Brown Trout Salmo trutta (strongest swimming). Testing included a 46-h enclosure study and 3-month extended study, during which fish passage was evaluated using PIT tags. All of the species exhibited successful passage through the fishway during the enclosure study, but movement probabilities varied by species. Five species were not detected at the fishway during the extended study, possibly due to issues with attraction flows, entrance conditions, or motivation. Hydraulic conditions within the fishway were also evaluated. Roughness elements maintained a benthic, low-velocity zone across a range of flows, even when surface and depth-averaged velocities surpassed the design criteria for the weakest swimming species. The methods from this study could be replicated at other locations to evaluate design criteria (e.g., slope, capacity, roughness, and configuration) and performance for a variety of fish species and fishway types.
A multisurface kinematic hardening model for the behavior of clays under combined static and undrained cyclic loading
Authors: Stoecklin Andreas , Friedli Balz , Puzrin Alexander M.
Published: September 2020

In dynamic geotechnical problems, soils are often subjected to a combination of sustained static and fast cyclic loading. Under such loading conditions, saturated and normally consolidated clays generally experience a build‐up of excess pore water pressure along with a degradation of stiffness and strength. If the strength of the soil falls below the static stress demand, a self‐driven failure is triggered. In this paper, a constitutive model is presented for the analysis of such problems, based on a general multisurface plasticity framework. The hardening behavior, the initial arrangement of the surfaces, and the nonassociated volumetric flow rule are defined to capture important aspects of cyclic clay behavior. This includes nonlinear hysteretic stress‐strain behavior, the effect of anisotropic consolidation, and the generation of excess pore water pressure during undrained cyclic loading along with a degradation of stiffness and strength. The model requires nine independent parameters, which can be derived from standard laboratory tests. A customized experimental program has been performed to validate the model performance. The model predictions show a good agreement with test results from monotonic and cyclic undrained triaxial tests, in particular with respect to the strain‐softening response and the number of loading cycles to failure. A procedure for a general stress‐space implicit numerical implementation for undrained, total stress‐based finite element analyses is presented, including the derivation of the consistent tangent operator. Finally, a simulation of the seismic response of a submarine slope is shown to illustrate a possible application of the presented model.
In utero myelomeningocele repair: The natural history of patients with incontinent pattern (sphincteric deficiency: leakage below 40 CMH20)
Authors: Macedo Antonio , Di Migueli Ricardo Del Debbio , Cavalheiro Sérgio , Moron Antonio , da Cruz Marcela Leal
Published: September 2020

Introduction

Since 2011 we have been following prospectively myelomeningocele patients treated in utero with particular interest to patients with sphincter weakness/deficiency. We investigated the changes of bladder pattern and upper urinary tract with time in children who underwent in utero repair and had low‐pressure incontinence based on urodynamic evaluation (UE).

Materials and Methods

From the 120 patients in our database, 117 had at least one UE. Of these, 30 were classified as incontinent when leaking at low pressure (<40 cmH20). We reviewed clinical evaluation, urinary tract ultrasound, voiding cystourethrography (VCUG), and other UE parameters at first and last evaluation.

Results

We found 30 cases (25.64%). Mean age at initial evaluation was 4.97 months followed by UE done initially at mean age of 5.73 months. Follow‐up was 28.4 months. Febrile urinary tract infection has been found in four patients (13.3%), hydronephrosis in four patients, and bladder neck thickening in three (10%). The VCUG showed vesicoureteral reflux in three cases (3/27, 11.1%). A total of 90% of patients had detrusor overactivity with mean maximum detrusor pressure (33.37 cmH20). Only 16.67% of patients showed normal bladder capacity. From the 30 patients, 23 had at least two UE. We noticed a change of bladder pattern as follows: six patients became of high‐risk pattern, five normal, and two with underactive bladder pattern. The average interval between the first and last UE was 25.5 months (median: 15 months).

Conclusion

We concluded that 43.47% of patients with low DLPP have kept the incontinent pattern. If the initial LPP was below 30 cmH20, 70% remained with the incontinet pattern.
Approximation of functions by a new construction ofBernstein‐Chlodowskyoperators: Theory and applications
Authors: Usta Fuat
Published: September 2020

The main motivation of this paper is to provide a generalization of Bernstein‐Chlodowsky type operators which depend on functionτby means of two sequences of functions. The newly defined operators fix the test function set{1, τ, τ2}. Then we present the approximation properties of newly defined operators, such as weighted approximation, degree of approximation and Voronovskaya type theorems. Finally, we present a series of numerical examples demonstrating the effectiveness of this newly defined Bernstein‐Chlodowsky operators for computing function approximation.
Efficacy of BRAF-Inhibitor Therapy in BRAF
V600E-Mutated Adult Langerhans Cell Histiocytosis
Authors: Hazim Antonious Z. , Ruan Gordon J. , Ravindran Aishwarya , Abeykoon Jithma P. , Scheckel Caleb , Vassallo Robert , Ryu Jay H. , Tobin W. Oliver , Koster Matthew J. , Bennani N. Nora , Rech Karen L. , Young Jason R. , Shah Mithun V. , Goyal Gaurav , Go Ronald S.
Published: September 2020

Langerhans cell histiocytosis (LCH) is a rare histiocytic neoplasm. To date, there is a lack of U.S. Food and Drug Administration–approved treatments in adult LCH to establish optimal first-line therapy. We conducted a retrospective, single-center case series evaluating the use of BRAF inhibitors in adult patients with BRAFV600E- LCH proven by biopsy. Our case series is the first to report the use of BRAF inhibitors as first-line therapy in adults with LCH. We also report the efficacy with single-agent dabrafenib in adult LCH. All but one of our patients had favorable response to targeted therapy.
Thermomechanical and structural characterization of polybutadiene/poly(ethylene oxide)/CNT stretchable electrospun fibrous membranes
Authors: Gürbüz Remzi , Sarac Baran , Soprunyuk Viktor , Yüce Eray , Eckert Jürgen , Ozcan Ali , Sarac A. Sezai
Published: September 2020

It is difficult to produce rubbery polymer nanofibers, that is, polybutadiene, by the method of electrospinning, since during electrospinning rubbery polymer fibers join and entangles due to their low Tg. For this reason, it is not easy to achieve the fiber form out of these polymers. Homogeneously electrospun carbon nanotubes (CNT)‐filled polybutadiene (PBu) and poly(ethylene oxide) (PEO) composite elastomeric fibers exhibit distinctive physical features such as uniform fiber diameter and distribution with significant improvements in thermomechanical properties. Controlled hydrophilicity/hydrophobicity with the components allows to generate homogenous, thermally stable and stretchable bio‐composite scaffold, and fibrous antibacterial membrane scaffolds out of PBu/PEO/CNT composite. We have combined the exciting properties of PEO with high pore density with the rubber elasticity of PBu via dissolving them in a dichloromethane/ethyl acetate organic solvent, and subsequently producing electrospun woven fibers with different PBu/PEO ratios. Frequency‐dependent thermomechanical characterization via dynamic mechanical analysis reveals pronounced changes in the onset and extent of melting, as well as the storage and loss modulus values at the onset of melting, in particular when small amounts (1.25% by wt%) of CNTs are present. The characteristic bands were detected for the PBu/PEO and PBu/PEO/CNT samples by means of Raman and Fourier‐transform infrared spectroscopy. CNT addition increases the hydrophobicity via the increase in roughness as attained by atomic force microscopy.
Acceleration of osteogenic differentiation by sustained release of BMP2 in PLLA/graphene oxide nanofibrous scaffold
Authors: Abazari Mohammad Foad , Nasiri Navid , Nejati Fatemeh , Kohandani Mina , Hajati‐Birgani Nazanin , Sadeghi Solmaz , Piri Peyman , Soleimanifar Fatemeh , Rezaei‐Tavirani Mostafa , Mansouri Vahid
Published: September 2020

After about three decades of experience, tissue engineering has become one of the most important approaches in reconstructive medical research to treat non‐self‐healing bone injuries and lesions. Herein, nanofibrous composite scaffolds fabricated by electrospinning, which containing of poly(L‐lactic acid) (PLLA), graphene oxide (GO), and bone morphogenetic protein 2 (BMP2) for bone tissue engineering applications. After structural evaluations, adipose tissue derived mesenchymal stem cells (AT‐MSCs) were applied to monitor scaffold's biological behavior and osteoinductivity properties. All fabricated scaffolds had nanofibrous structure with interconnected pores, bead free, and well mechanical properties. But the best biological behavior including cell attachment, protein adsorption, and support cells proliferation was detected by PLLA‐GO‐BMP2 nanofibrous scaffold compared to the PLLA and PLLA‐GO. Moreover, detected ALP activity, calcium content and expression level of bone‐related gene markers in AT‐MSCs grown on PLLA‐GO‐BMP2 nanofibrous scaffold was also significantly promoted in compression with the cells grown on other scaffolds. In fact, the simultaneous presence of two factors, GO and BMP2, in the PLLA nanofibrous scaffold structure has a synergistic effect and therefore has a promising potential for tissue engineering applications in the repair of bone lesions.
Comprehensive genetic features of gastric mixed adenoneuroendocrine carcinomas and pure neuroendocrine carcinomas
Authors: Koh Jiwon , Nam Soo Kyung , Kwak Yoonjin , Kim Gilhyang , Kim Ka‐Kyung , Lee Byung‐Chul , Ahn Sang‐Hoon , Park Do Joong , Kim Hyung‐Ho , Park Kyoung Un , Kim Woo Ho , Lee Hye Seung
Published: September 2020

We aimed to determine the pathogenesis of gastric mixed adenoneuroendocrine carcinoma (MANEC) and pure neuroendocrine carcinoma (NEC), which is largely unknown. Targeted DNA sequencing was performed on 34 tumor samples from 21 patients – 13 adenocarcinoma (ADC)/NEC components from MANECs and eight pure NECs – and 21 matched non‐neoplastic gastric tissues. Mutational profiles of MANECs/NECs were compared with those of other tumors using public databases. The majority (64.1%; 59/92) of mutations in MANEC were shared by both ADC and NEC components.TP53was the most commonly mutated gene in MANEC (69.2%, 9/13) and pure NEC (87.5%, 8/9). AllTP53mutations in MANEC were pathogenic mutations and were shared by both ADC and NEC components. A subset ofTP53WTMANECs had a microsatellite‐unstable phenotype or amplifications in various oncogenes includingERBB2andNMYC, and the onlyTP53WTpure NEC harboredMYCamplification. Compared to NEC in other organs, NECs arising from the stomach had unique features including less frequentRB1mutations. Differentially altered genes of MANEC ADC components were significantly associated with receptor tyrosine kinase signaling pathways, while differentially altered genes of MANEC NEC components were significantly associated with the NOTCH signaling pathway. Our data provide evidence suggesting a possible clonal origin of ADC and NEC components of MANEC, and we found that gastric MANECs and pure NECs are distinct entities with unique mutational profiles and underlying protein networks. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Reinforcement of poly(ether ketone) by introducing fluorene groups and their effect on thermal and mechanical properties
Authors: Wei Jiaxin , Shang Yingshuang , Xu Da , Wang Zhaoyang , Jiang Zilong , Gao Yanwei , Zhang Haibo
Published: September 2020

A series of novel poly(ether ketone) copolymers with different contents of fluorene groups were synthesized. The effects of fluorene group content on the thermal and mechanical properties of poly(ether ketone) copolymers were investigated. The introduction of a low content of fluorene groups can lead to an increase in glass transition temperature, thermal stability and heat deflection temperature. Among them, the heat deflection temperature of 10% fluorene‐containing poly(ether ketone) copolymers (PEK‐FD10) increases from 178 °C (pure poly(ether ketone)) to 196 °C, which means that the material has a higher heat resistance rating. Compared with poly(ether ketone)s, these copolymers have excellent mechanical properties. When the content of fluorene groups is only 2% (PEK‐FD2), the strength is significantly improved. And the flexural strength of PEK‐FD2 is 149.3 MPa, which is 12% higher than that of poly(ether ketone). It is worth noting that the fracture toughness and impact toughness are also increased significantly. The strain at break of PEK‐FD2 is up to 88% and the impact toughness of PEK‐FD2 is 54.6 J m−1. This suggests that the introduction of minute contents of fluorene groups can simultaneously increase the strength and toughness. © 2020 Society of Industrial Chemistry
Association between CD8 and PD‐L1 expression and outcomes after radical prostatectomy for localized prostate cancer
Authors: Vicier Cecile , Ravi Praful , Kwak Lucia , Werner Lillian , Huang Ying , Evan Carolyn , Loda Massimo , Hamid Anis A. , Sweeney Christopher J.
Published: September 2020

Background

Characterization of markers of both immune suppression and activation may provide more prognostic information than assessment of single markers in localized prostate cancer. We therefore sought to determine the association between CD8 and PD‐L1 expression in localized prostate tumors and biochemical recurrence (BCR) and metastasis‐free survival (MFS).

Methods

Tissue microarrays were constructed on 109 men undergoing radical prostatectomy (RP) for localized prostate cancer at Dana–Farber Cancer Institute between 1991 and 2008. Fluorescence immunohistochemistry was used to evaluate the expression of six immune markers (CD3, CD4, CD8, PD‐1, PD‐L1, FOXP3). Quantitative multispectral imaging analysis was used to calculate the density of each marker, which was dichotomized by the median as “high” or “low.” Cox proportional hazards regression models and Kaplan–Meier analyses were used to analyze associations between immune marker densities and time to BCR and MFS.

Results

Over a median follow‐up of 8.1 years, 55 (51%) and 39 (36%) men developed BCR and metastases, respectively. Median time to BCR was shorter in men with low CD8 (hazard ratio [HR] = 2.27 [1.27–4.08]) and high PD‐L1 expression (HR = 2.03 [1.17‐3.53]). While neither low CD8 or high PD‐L1 alone were independent predictors of BCR or MFS on multivariable analysis, men with low CD8 and/or high PD‐L1 had a significantly shorter time to BCR (median 3.5 years vs. NR) and MFS (median 10.8 vs. 18.4 years) compared to those with high CD8 and low PD‐L1 expression. The main limitation is the retrospective and singe‐center nature of the study.

Conclusion

The presence of higher CD8 and lower PD‐L1 expression in prostatectomy specimens was associated a low risk of biochemical relapse and metastatic disease. These findings are hypothesis‐generating and further study is needed.