bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessing an ecological security network for a rapid urbanization region in Eastern China
Authors: Zhou De , Lin Zhulu , Ma Siming , Qi Jialing , Yan Tingting
Published: March 2021

Rapid urbanization leads to fragmentation of landscape and destruction of the ecological security network. A sound ecological security network promotes connectivity between ecological sources and mitigates the degradation of an ecological system. However, when identifying the ecological sources of the ecological network, studies available in the current literature did not simultaneously consider the structures, functions, and values of ecological patches. Our study aimed to fill this research gap, and our objective was to improve the framework for assessing the ecological security network. We demonstrated the application of the proposed framework through a case‐study of the urban agglomeration around Hangzhou Bay (UAHB), a rapid urbanization region in Eastern China. We improved the identification method of ecological sources by integrating the evaluations of ecosystem services value and ecological sensitivity, while we screened ecological sources by using the rank‐size rule and the natural breaks method. Based on the screened ecological sources, the ecological corridors were reconstructed and optimized for the UAHB region. The results from this study showed that ecological network has actually improved in the UAHB in the last 20 years. However, the structure and function of the ecological security network were strongly influenced by human activities and urban sprawl. The ecological security network has deteriorated locally in eastern coastal areas of UAHB during the past 20 years with strong spatial variability in ecological security patterns. To maintain an environment with well‐protected ecological quality, we proposed a set of five measures to improve the sustainable development of the ecological system.
Determining usages in post‐mining sites according to landscape design approaches
Authors: Gulpinar Sekban Demet Ulku , Acar Cengiz
Published: March 2021

Today, with the gradual expansion of city centres, mining sites neighbouring cities have become high‐potential landscapes on which user needs and urban ecological necessities can be satisfied. However, as works on such fields remain at the upper scale and planning level, subscale design efforts required to give the areas in question an identity and usage opportunities are quite limited. Within this context, the present study aims to create various usage paradigms by evaluating the landscaping potentials of new landscape elements in rehabilitated mining sites. The study defined these new landscape elements and determined usage scenarios for the landscape elements by following different design approaches. These new usage scenarios were categorized into three different design orientations as nature‐oriented, human‐oriented, and mixed‐use. These categorizations were then transformed into 30 paradigms based on deliberations with experts. The aim here was to define multipurpose usages required for natural and human needs in rehabilitated mining sites.
Characterising spatiotemporal vegetation variations using LANDSAT time‐series and Hurst exponent index in the Mekong River Delta
Authors: Tran Thuong V. , Tran Duy X. , Nguyen Ho , Latorre‐Carmona Pedro , Myint Soe W.
Published: March 2021

Spatiotemporal analysis and monitoring of vegetation help us investigate ecological health and guide better forest conservation and land management practices for sustainable development. This paper proposes the use of spatial analysis approaches (i.e., ordinary least squares [OLS] and the Hurst exponent) combined with time‐series analysis using enhanced vegetation index (EVI) data, derived from LANDSAT via the Google Earth Engine, to estimate the trends and sustainability of vegetation dynamics in the Tra Vinh Province in the Mekong River Delta. We also assessed the EVI changes connected to land change issues to examine the influence of land use conversion on vegetation dynamics. Results show that a large portion of the study area was covered by abundant vegetation (over 50% of the total area), and the increased EVI area was about 5.5‐times greater than the area of EVI reduction. Additionally, vegetation sustainability was being seriously compromised (e.g., a decrease in the total area of 8,275 ha) due to several land conversion drivers such as shrimp farming, urbanisation, and industrialisation. Furthermore, results obtained from this research provide insight into the spatiotemporal dynamics of vegetation coverage and reveal the consistency of future vegetation trends. Moreover, the study also quantitatively assessed the positive impacts of Buddhist doctrines on reducing the negative trend of vegetation change in the study area. These findings can lay the ground to formulate sustainable land and environmental plans that meet the 11th, 13th and 15th Sustainable Development Goals (SDGs) (i.e., the sustainable cities and communities, the climate actions, and the life on land). Besides, the analytical procedure adopted in this study can also be applicable to any other coastal areas that require the accurate assessment of vegetation status over time.
Comparison Study of the Effects of Cationic Liposomes on Delivery across 3D Skin Tissue and Whitening Effects in Pigmented 3D Skin
Authors: Lee Mi So , Lee Ju Won , Kim Su Ji , Pham‐Nguyen Oanh‐Vu , Park Jongmin , Park Ju Hyun , Jung Young Mee , Lee Jun Bae , Yoo Hyuk Sang
Published: March 2021

Charged phospholipids are employed to formulate liposomes with different surface charges to enhance the permeation of active ingredients through epidermal layers. Although 3D skin tissue is widely employed as an alternative to permeation studies using animal skin, only a small number of studies have compared the difference between these skin models. Liposomal delivery strategies are investigated herein, through 3D skin tissue based on their surface charges. Cationic, anionic, and neutral liposomes are formulated and their size, zeta‐potential, and morphology are characterized using dynamic light scattering and cryogenic‐transmission electron microscopy (cryo‐TEM). A Franz diffusion cell is employed to determine the delivery efficiency of various liposomes, where all liposomes do not exhibit any recognizable difference of permeation through the synthetic membrane. When the fluorescence liposomes are applied to 3D skin, considerable fluorescence intensity is observed at the stratum cornea and epithelium layers. Compared to other liposomes, cationic liposomes exhibit the highest fluorescence intensity, suggesting the enhanced permeation of liposomes through the 3D skin layers. Finally, the ability of niacinamide (NA)‐incorporated liposomes to suppress melanin transfer in pigmented 3D skin is examined, where cationic liposomes exhibit the highest degree of whitening effects.
Fluoropolymer‐Mediated Intracellular Delivery of miR‐23b for the Osteocyte Differentiation in Osteoblasts
Authors: Wang Sihan , Xing Jiakai , Xiong Boyu , Han Haobo , Hu Min , Li Quanshun
Published: March 2021

Emerging evidence suggests that microRNAs (miRNAs) play key roles in the regulation of multiple biological processes, including the differentiation of osteoblasts. Although miRNA‐based gene therapy holds immense potential in the treatment of a variety of diseases, the intracellular delivery of miRNA remains challenging owing to the lack of efficient and safe gene carriers. In this study, a fluoropolymer (FP) is constructed through the modification of polyamidoamine (PAMAM) using heptafluorobutyric anhydride and then is used as a carrier for miR‐23b transfection to induce osteocyte differentiation of osteoblasts. The derivative FP is found to facilitate miR‐23b transfection due to its favorable endosomal escape from the "proton sponge" effect. Compared to PAMAM/miR‐23b, the FP/miR‐23b nanocomplex efficiently promotes the differentiation of osteoblasts and formation of calcified nodules, attributable to enhanced expression of various osteogenesis genes (runt‐related transfection factor 2 [RUNX2], alkaline phosphatase [ALP], osteopontin [OPN], and osteocalcin [OCN]). Thus, FP‐mediated miR‐23b transfection may be used as an effective strategy to facilitate osteogenic differentiation.
Free but fake speech: When giving primacy to the source decreases misinformation sharing on social media
Authors: Di Domenico Giandomenico , Nunan Daniel , Sit Jason , Pitardi Valentina
Published: March 2021

Social media platforms are facing increasing tensions in balancing the desire to maintain freedom of expression with limiting the spread of fake news and misinformation. This study investigates whether giving primacy to the source of misinformation on Facebook influences users' sharing behaviour. Two experimental studies show that when fake news is presented in a source‐primacy format, users are less likely to share the post because of reduced trust in the message and increased perceptions of deceptive intent. Additionally, this effect persists only when the person sharing the fake news has a weak interpersonal relationship with the receiver. The study extends current understanding of how misinformation is shared and provides insights into how presentation formats can be used to limit the spread of fake news without restricting freedom of speech.
Stimuli‐Responsive Multifunctional Phenylboronic Acid Polymers Via Multicomponent Reactions: From Synthesis to Application
Authors: Zeng Yuan , Zhu Chongyu , Tao Lei
Published: March 2021

Stimuli‐responsive polymers undergo changes under different environmental conditions. Among them, phenylboronic acid (PBA) containing polymers (PBA‐polymers) are unique, because they can selectively react with diols to generate borates that are sensitive to pH, sugars, and H2O2, and can be effectively used to synthesize smart drug carriers and self‐healing hydrogels. Recently, multifunctional PBA‐polymers (MF‐PBA‐polymers) have been developed using multicomponent reactions (MCRs) to introduce PBA groups into polymer structures. These MF‐PBA‐polymers have features similar to those of traditional PBA‐polymers; moreover, they exhibit additional properties, such as fluorescence, antimicrobial activity, and antioxidant capability, when different MCRs are used. In this mini review, the preparation of these MF‐PBA‐polymers are summarized and the new properties/functions that have been introduced into these polymers using different MCRs are discussed. The uses of these MF‐PBA‐polymers as fluorescent cell anticoagulants, drug carriers, and gelators of functional self‐healing hydrogels have been discussed. Additionally, the challenges encountered during their preparation are discussed and also the future developments in this field are touched upon.
Twist1 is required for the development of UVB‐induced squamous cell carcinoma
Authors: Eguiarte‐Solomon Fernando , Blazanin Nicholas , Rho Okkyung , Carbajal Steve , Felsher Dean W. , Tran Phuoc T. , DiGiovanni John
Published: March 2021

The transcription factor Twist1 has been reported to be essential for the formation and invasiveness of chemically induced tumors in mouse skin. However, the impact of keratinocyte‐specific Twist1 deletion on skin carcinogenesis caused by UVB radiation has not been reported. Deletion of Twist1 in basal keratinocytes of mouse epidermis using K5.Cre × Twist1flox/flox mice led to significantly reduced UVB‐induced epidermal hyperproliferation. In addition, keratinocyte‐specific deletion of Twist1 significantly suppressed UVB‐induced skin carcinogenesis. Further analyses revealed that deletion of Twist1 in cultured keratinocytes or mouse epidermis in vivo led to keratinocyte differentiation. In this regard, deletion of Twist1 in epidermal keratinocytes showed significant induction of early and late differentiation markers, including TG1, K1, OVOL1, loricrin, and filaggrin. Similar results were obtained with topical application of harmine, a Harmala alkaloid that leads to degradation of Twist1. In contrast, overexpression of Twist1 in cultured keratinocytes suppressed calcium‐induced differentiation. Further analyses using both K5.Cre × Twist1flox/flox mice and an inducible system where Twist1 was deleted in bulge region keratinocytes showed loss of expression of hair follicle stem/progenitor markers, including CD34, Lrig1, Lgr5, and Lgr6. These data support the conclusion that Twist1 has a direct role in maintaining the balance between proliferation and differentiation of keratinocytes and keratinocyte stem/progenitor populations. Collectively, these results demonstrate a critical role for Twist1 early in the process of UVB skin carcinogenesis, and that Twist1 may be a novel target for the prevention of cutaneous squamous cell carcinoma.
De novo c.2455C>T mutation of NPR2 gene in a fetus with shortened long bones and a ventricular septal defect conceived by a mother with a fragile site at 16q22.1 and a father with a rare heterochromatic variant of chromosome 4 from Vietnam
Authors: Ha Thi Minh Thi , Nguyen Tran Thao Nguyen , Nguyen Thi Mai Ngan , Nguyen Huu Nguyen
Published: March 2021

Background

A heterozygous natriuretic peptide receptor 2 (NPR2) gene c.2455C>T mutation was identified as a cause of familial idiopathic short stature (ISS). Only two cases with this mutation were reported previously, and the probands with ISS had no organ system defects.

Methods

Next‐generation sequencing (NGS) was performed on an amniotic fluid DNA sample of a fetus with shortened long bones and a small ventricular septal defect detected by an obstetric ultrasound examination. The pathogenic variant of the fetus was confirmed by Sanger sequencing. Sanger sequencing, G‐banded, and C‐banded karyotyping of the fetus's parents were subsequently performed.

Results

A de novo NPR2 gene c.2455C>T, p.(Arg819Cys) mutation was identified in the fetus. No microdeletion or microduplication was identified in the fetus by copy number variation sequencing with a maximum resolution of 400 kb. The two previous miscarriages experienced by the fetus's parents were interpreted as a result of chromosomal aberrations, including a maternal fragile site at 16q22.1 and a rare paternal variant involving in a large G‐band‐positive and C‐band‐positive block of paracentric heterochromatin of chromosome 4p.

Conclusion

This report provides clinical signs of a de novo heterozygous NPR2 gene c.2455C>T mutation in the fetus and shows paternal chromosomal aberrations causing repeated pregnancy loss.
Oversight question looms in lawsuit on Mississippi mental health system
Authors: Enos Gary
Published: March 2021

Mississippi state officials appear to be moving closer to resolving a long‐standing federal lawsuit over deficiencies in the state's mental health system, though a controversial question of who may oversee system improvements after a final agreement is reached still looms over the parties' discussions.
Medicaid directors offer strategies to expand behavioral health
Authors: Canady Valerie A.
Published: March 2021

The economic fallout from the pandemic and long‐standing racial and ethnic disparities have no doubt impacted the country's emotional well‐being, according to the National Association of Medicaid Directors (NAMD), which has released a report offering states options to consider to promote the health and well‐being of its members and expand access to behavioral health services.
Advocates praise support from new COVID‐19 relief package
Authors: Canady Valerie A.
Published: March 2021

The House last week passed the $1.9 trillion COVID‐19 relief bill, garnering support, not to mention relief, from mental health advocates who are praising the billions of dollars that will fund crucial mental health and substance use services.
APA to accredit master's program in health service psychology
Authors: Canady Valerie A.
Published: March 2021

Following a nearly 70‐year‐old debate between the American Psychological Association (APA) and the field about the role of master's‐trained individuals in psychology, the APA is inching a step closer to accrediting master's‐level programs in health service psychology. The move seeks to ensure quality in training, officials announced.
Mathematical modeling of the dynamics of a hydroelastic system—A hollow cylinder with inhomogeneous initial stresses and compressible fluid
Authors: Akbarov Surkay D. , Sevdimaliyev Yusif M. , Valiyev Gurbanali J.
Published: March 2021

This work attempts to present mathematical modeling of the dynamics of the hydroelastic system consisting of a hollow cylinder with inhomogeneous initial stresses and a compressible barotropic inviscid fluid which filled the interior of the cylinder. The motion of the cylinder is described with the 3D linearized theory of elastic waves in bodies with initial stresses; however, the flow of the fluid is described with the linearized Euler equations for compressible inviscid fluid. Formulations of the boundary conditions on the outer surface of the cylinder and compatibility conditions between the cylinder and fluid on the interior surface of the cylinder are presented. Concrete formulations are made for the axisymmetric case, and general aspects of the solution methods of the formulated problems are considered. Under these considerations, two types of problem are selected: (1) the axisymmetric longitudinal wave propagation and (2) fluid flow profile on the outer free surface of the cylinder—the “circular” radial moving load. Numerical results are presented and discussed for the first type of problem. In particular, it is established that the character of the influence of the inhomogeneous initial stresses on the wave propagation velocity in the hydroelastic system under consideration depends on the dimensionless wavenumber. The perspective of future investigations is also presented and discussed.
SimPET—An open online platform for the Monte Carlo simulation of realistic brain PET data. Validation for 18F‐FDG scans
Authors: Paredes‐Pacheco José , López‐González Francisco Javier , Silva‐Rodríguez Jesús , Efthimiou Nikos , Niñerola‐Baizán Aida , Ruibal Álvaro , Roé‐Vellvé Núria , Aguiar Pablo
Published: March 2021

Purpose

SimPET (www.sim‐pet.org) is a free cloud‐based platform for the generation of realistic brain positron emission tomography (PET) data. In this work, we introduce the key features of the platform. In addition, we validate the platform by performing a comparison between simulated healthy brain FDG‐PET images and real healthy subject data for three commercial scanners (GE Advance NXi, GE Discovery ST, and Siemens Biograph mCT).

Methods

The platform provides a graphical user interface to a set of automatic scripts taking care of the code execution for the phantom generation, simulation (SimSET), and tomographic image reconstruction (STIR). We characterize the performance using activity and attenuation maps derived from PET/CT and MRI data of 25 healthy subjects acquired with a GE Discovery ST. We then use the created maps to generate synthetic data for the GE Discovery ST, the GE Advance NXi, and the Siemens Biograph mCT. The validation was carried out by evaluating Bland‐Altman differences between real and simulated images for each scanner. In addition, SPM voxel‐wise comparison was performed to highlight regional differences. Examples for amyloid PET and for the generation of ground‐truth pathological patients are included.

Results

The platform can be efficiently used for generating realistic simulated FDG‐PET images in a reasonable amount of time. The validation showed small differences between SimPET and acquired FDG‐PET images, with errors below 10% for 98.09% (GE Discovery ST), 95.09% (GE Advance NXi), and 91.35% (Siemens Biograph mCT) of the voxels. Nevertheless, our SPM analysis showed significant regional differences between the simulated images and real healthy patients, and thus, the use of the platform for converting control subject databases between different scanners requires further investigation.

Conclusions

The presented platform can potentially allow scientists in clinical and research settings to perform MC simulation experiments without the need for high‐end hardware or advanced computing knowledge and in a reasonable amount of time.
Management of low back pain: Treatment provision within private practice in the UK in the context of clinical guidelines
Authors: Murtagh Shemane , Bryant Elizabeth , Hebron Clair , Ridehalgh Colette , Horler Christopher , Trosh Caroline , Olivier George
Published: March 2021

Objective

To summarise the combination of treatments private UK‐based physiotherapists use with patients who have low back pain (LBP) and the extent to which the treatments used are consistent with clinical guideline recommendations.

Design

Cross‐sectional observational survey.

Methods

Data were collected from physiotherapists within private UK‐based clinics using an online standardised data collection system to record the treatment they provided for patients who had LBP with/without leg pain. Treatment data were classified into those that are ‘recommended’, ‘not recommended’ and had ‘no recommendation’.

Results/Findings

Treatment provided to 8003 patients were included in the analyses. Most patients (95.0%) were provided with a ‘recommended’ treatment. Approximately half of the patients who received ‘recommended’ treatment were also provided with other treatments that were either ‘not recommended’ (16.7%), had ‘no recommendation’ (16.6%) or a combination of both (13.0%). Few patients were provided with only treatments that were ‘not recommended’ and/or treatment with ‘no recommendation’ (4.6%).

Conclusion

This study provides insight into the self‐reported practice of participating physiotherapists and highlights how they generally adopted a multimodal treatment model for patients with LBP. Consistent with the National Institute for Health and Care Excellence guidelines, most patients received information and advice often in conjunction with exercise and manual therapy. Only a small proportion of patients were provided with treatments that are ‘not recommended’ and/or treatment that had ‘no recommendation’. These findings are useful in documenting the implementation of clinical guidelines given the need for practitioners to balance the best available evidence with patient expectation and preference and to facilitate the therapeutic alliance.
Hydroacoustic Surveys Underestimate Yellow Perch Population Abundance: The Importance of Considering Habitat Use
Authors: Mrnak Joseph T. , Sikora Logan W. , Jake Vander Zanden M. , Hrabik Thomas R. , Sass Greg G.
Published: March 2021

When estimating fish population abundance, it is important to recognize that differing habitat use may cause one gear type to be more effective and less biased than another. We generated and compared population abundance estimates (PE) for adult Yellow Perch Perca flavescens in Crystal Lake, Wisconsin using a spring mini-fyke net mark–recapture survey and summer hydroacoustic surveys. Mean PE from the spring mark–recapture survey was 11,051 adult Yellow Perch (95% confidence limits of 9,878 and 12,541). This mean was 4.0–8.5 times greater than the range of mean summer hydroacoustic estimates (mean ± 95% CI = 1,291 ± 312 and 2,912 ± 703). Due to Yellow Perch spawning behavior, we assumed that the spring mark–recapture survey sampled the entire adult population, while summer hydroacoustics sampled the postspawn pelagic component. Using the mean of all hydroacoustic surveys (PE = 2,492; n = 5), we estimated that approximately 22% of adult Yellow Perch selected for pelagic habitats postspawn. Our study emphasizes the importance of evaluating gear bias and has implications for future assessments, particularly when the target species may exhibit multiple habitat preferences within a lake.
Ingestion of PIT Tags by Hatchery-Reared Juvenile Steelhead and Subsequent Detection at Main-Stem Dams in the Columbia River Basin
Authors: Peterson Douglas P. , Engle Rod O.
Published: March 2021

During the past 30 years, millions of hatchery-reared Pacific salmon Oncorhynchus spp. have been implanted with PIT tags to estimate their survival and track their migration through the extensive system of hydroelectric dams in the Columbia River basin. The mark–recapture models that are used for these analyses assume that the tags are not lost, making it important to understand retention rates for PIT tags and the fate of shed tags. To understand the potential fate of shed PIT tags in a production hatchery, we distributed 12-mm PIT tags in two traditional cement raceways and the two circular tanks of a partial reuse aquaculture system (PRAS) containing juvenile summer steelhead O. mykiss. We then monitored the detection of these PIT tags at the time that the fish were released as smolts and at main-stem dams during their migration. The probability that a loose PIT tag was inside a steelhead smolt at release ranged from 0.200 to 0.519 across the raceways and tanks, confirming that the fish consumed tags during hatchery rearing. Detections at six dams—including one located 1,208 km from the release site—and up to 36 d after smolt release confirmed that some ingested tags remained in the steelhead during their migration. The estimates of apparent survival for smolts with ingested and implanted PIT tags suggested that some ingested tags were being excreted during migration through the Columbia River basin. The results highlight the need to reevaluate assumptions about the fate of shed PIT tags in steelhead production hatcheries and ensure that biologists and managers have reliable estimates of tag retention.
A refitting experiment on long bone identification
Authors: Morin Eugène , Boileau Arianne , Ready Elspeth
Published: March 2021

Refitting is an important analytical tool in archaeology that can yield valuable information on site formation processes and on the range of activities practiced at a site, including tool production, tool curation, and discard behavior, among others. In the present paper, we use refit data from a control assemblage of red deer (Cervus elaphus) long bones to assess problems of specimen identification and representation in an experiment where bones were processed for marrow. Three goals motivated this experiment: (i) to assess how different methods of NISP (number of identified specimens) calculation affect comparisons of the relative abundances of long bone regions, (ii) to evaluate whether long bone shaft regions vary with respect to the probability of identification, and (iii) to ascertain the potential refit rate for a well‐preserved and fully‐collected sample of faunal specimens. Our results show no statistical differences in terms of patterns of skeletal representation between the two methods of NISP calculation (single vs. multiple NISP counts) that we assessed. Our data also indicate that the shape, particularly the cross‐section, of fragments clearly impacts the probability of identification and refitting. Moreover, the refitting experiment reveals that, in ideal conditions, a majority of specimens (>95%) from the NISP sample can be refitted, which leads to largely reconstructed skeletal elements. Thus, the comparatively very low refit rates recorded in archaeological sites, including samples that are well preserved, suggest that the often limited extent of excavations, along with offsite discard and/or extensive sharing of parts, substantially reduce the possibility of finding refits in a faunal sample.
Unmasking the potential role of plant‐based medicine “Plumbagin” in oral cancer—A Novel Paradigm
Authors: Taneja Neeraj , Alam Aftab , Patnaik Ranjana S. , Taneja Tannu
Published: March 2021

Introduction

Cancer is a deadly disease affecting 185 countries with about 10 million deaths worldwide. Barring high cost, modern cancer treatment and allopathic medicines are double‐edged sword due to the side effects which is a major concern to worry; therefore, the time has come to look for plant‐based herbal treatment like Plumbagin.

Objectives

To enlighten the role of Plumbagin in cancer treatment, to highlight the much‐needed plant extract Plumbagin for oral cancer treatment, and to encourage the further research on medicinal plants that result in the discovery of potent anticancer agent.

Methodology

Literature search was accomplished using Google‐scholar, PubMed, EBSCO, and Scopus databases. Data were collected by electronic and manual search. The articles were scrutinized carefully and those which were not relevant to our search were omitted. The data were compiled depicting the role of Plumbagin in different types of cancer and cancer cell lines in general and oral cancer in particular.

Results

In vitro and in vivo studies of Plumbagin have shown anti‐oncogenic properties in almost all types of cancer of the body. But only a few in vitro studies and in vivo studies have been conducted to prove its anticancer potential in oral cancer.

Conclusion

Plant‐based medicines are being increasingly recognized as useful complementary treatments for cancer as they are most suited, safe, cost‐effective, and easily biodegradable with no significant side‐effects. Plumbagin is one such phytocompound that has immense anti‐oncogenic medicinal and therapeutic properties. There is an urgent need to do more studies on this novel drug for oral cancer. Additionally, clinical studies are also required for the evolution of Plumbagin as anticancer drug for oral cancer.
A novel phosphorus‐nitrogen flame retardant for improving the flame retardancy of polyamide 6: Preparation, properties, and flame retardancy mechanism
Authors: Zheng Tao , Wang Wengui , Liu Yaochi
Published: March 2021

In this work, a novel phosphorus–nitrogen flame retardant (CN‐DOPO), which was successfully prepared via a facile method of graphitic carbon nitride (g‐C3N4) and 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO). Polyamide 6 (PA6) composites were then prepared through melt blending with different ratios of g‐C3N4/DOPO and different contents of CN‐DOPO. CN‐DOPO was characterized and confirmed using X‐ray diffraction (XRD), Fourier transform infrared spectra (FTIR), and scanning electron microscopy (SEM). PA6/CN‐DOPO composites were investigated by limiting oxygen index (LOI), vertical combustion (UL‐94), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), and thermogravimetric analysis‐infrared spectrometry (TGA‐IR). The results indicated LOI value was increased from 23.4% to 29.2% and successfully passed UL‐94 V‐0 rating when the presence of CN‐DOPO increased to 15 wt%. Moreover, mechanical properties of PA6/CN‐DOPO composites had not deteriorated significantly due to CN‐DOPO having better dispersion and compatibility in PA6. The morphological of char layer revealed that CN‐DOPO formed a highly integrated char layer surface during the combustion process, as compared to that of pure PA6. Meanwhile, CN‐DOPO decomposed to release gases could inhibit decomposition by diluting flammable volatiles. Accordingly, the special gas‐condensed phase synergistic flame‐retardant mechanism of PA6/CN‐DOPO was proposed. This work indicated that CN‐DOPO could endow PA6 with highly effective flame‐retardant and good mechanical performance.
Modeling of the resin transfer molding process including viscosity dependence with time and temperature
Authors: Soares Laisa Luiz , Amico Sandro Campos , Isoldi Liércio André , Souza Jeferson Avila
Published: March 2021

Flow behavior inside the mold cavity of liquid molding processes such as resin transfer molding (RTM) is important information that is necessary to determine filling time and void formation. Most of the studies found in the literature use isothermal models with Newtonian fluids and constant viscosities. However, for some specific applications, the mold filling time dependence on temperature and the viscosity dependence on time and temperature must be considered to precisely predict the flow advance inside the mold. In this study, a viscosity model, that accounts for temperature and time dependence is coupled with a standard computational fluid dynamics (CFD) model to simulate the resin advance inside an RTM mold cavity. The model is simpler than similar methods that describe viscosity as a function of temperature and resin conversion. Nevertheless, the results show that the proposed model is capable of calculating flow advance, air and resin temperatures, and viscosity changes with time and temperature as expected in actual RTM and correlated processing of thick parts or with low injection pressure or high fiber content.
Self‐esteem as a mediator of parental attachment security and social anxiety
Authors: Seon Youngwoon
Published: March 2021

This study examined the mediating role of self‐esteem on the relationship between parental attachment security and social anxiety in children, separating maternal and paternal attachment. A total of 298 Korean children in 5th and 6th grade participated. Using structural equation modeling, results showed that the research model fit the data well and the mediating effects of self‐esteem were statistically significant. Self‐esteem fully mediated both relationships between maternal and paternal attachment security and social anxiety. This finding suggests the importance of maternal and paternal attachment security and self‐esteem as protective factors against social anxiety in children. Implications for practice and future research directions are discussed.
Controlling the molecular weight of poly(2,5‐bis[N‐methyl‐N‐hexylamino]phenylene vinylene) using nitrobenzene as an inhibitor
Authors: Garrison Michael D. , Sotuyo Ania , Stenger‐Smith John D. , Baldwin Lawrence C. , Baca Alfred J.
Published: March 2021

Poly(2,5‐bis[N‐methyl‐N‐hexylamino] phenylene vinylene) (BAM‐PPV) has been studied for several decades as an anti‐corrosion coating. Although the polymer is readily synthesized via base‐promoted radical chain polymerization, BAM‐PPV exhibits poor solubility at high‐molecular weights (Mw > 100 kDa), which limits its applications. In this work, the molecular weight of BAM‐PPV was modulated with nitrobenzene. At nitrobenzene loading as low as 0.9 mol%, the polymerization reaction produced low‐molecular weight BAM‐PPV (Mw = 5–46 kDa). The polymerization of BAM‐PPV was systematically studied via size‐exclusion chromatography (SEC), liquid chromatography–mass spectrometry (LC‐MS), and 1H NMR spectroscopy, which revealed suppression of the dimer intermediate before chain polymerization. Collectively, this work could expand the practical applications of BAM‐PPV for use in optoelectronic devices or corrosion inhibition coatings.
Characteristics of infants or children presenting to outpatient bronchopulmonary dysplasia clinics in the United States
Authors: Collaco Joseph M. , Agarwal Amit , Austin Eric D. , Hayden Lystra P. , Lai Khanh , Levin Jonathan , Manimtim Winston M. , Moore Paul E. , Sheils Catherine A. , Tracy Michael C. , Alexiou Stamatia , Baker Christopher D. , Cristea A. Ioana , Fierro Julie L. , Rhein Lawrence M. , Villafranco Natalie , Nelin Leif D. , McGrath‐Morrow Sharon A.
Published: March 2021

Introduction

Bronchopulmonary dysplasia (BPD) is a common respiratory sequelae of preterm birth, for which longitudinal outpatient data are limited. Our objective was to describe a geographically diverse outpatient cohort of former preterm infants followed in BPD‐disease specific clinics.

Methods

Seven BPD specialty clinics contributed data using standardized instruments to this retrospective cohort study. Inclusion criteria included preterm birth (<37 weeks) and respiratory symptoms or needs requiring outpatient follow‐up.

Results

A total of 413 preterm infants and children were recruited (mean age: 2.4 ± 2.7 years) with a mean gestational age of 27.0 ± 2.8 weeks and a mean birthweight of 951 ± 429 grams of whom 63.7% had severe BPD. Total, 51.1% of subjects were nonwhite. Severe BPD was not associated with greater utilization of acute care/therapies compared to non‐severe counterparts. Of children with severe BPD, differences in percentage of those on any home respiratory support (p = .001), home positive pressure ventilation (p = .003), diuretics (p < .001), inhaled corticosteroids (p < .001), and pulmonary vasodilators (p < .001) were found between centers, however no differences in acute care use were observed.

Discussion

This examination of a multicenter collaborative registry of children born prematurely with respiratory disease demonstrates a diversity of management strategies among geographically distinct tertiary care BPD centers in the United States. This study reveals that the majority of children followed in these clinics were nonwhite and that neither variation in management nor severity of BPD at 36 weeks influenced outpatient acute care utilization. These findings suggest that post‐neonatal intensive care unit factors and follow‐up may modify respiratory outcomes in BPD, possibly independently of severity.
Normal growth variance by Z scores should be considered when interpreting the growth inhibitory effect of inhaled corticosteroids
Authors: Sidhu Sonam Tanna , Morphew Tricia , Galant Stanley P.
Published: March 2021

Background

Randomized clinical trials suggest that long‐term inhaled corticosteroid (ICS) treatment significantly inhibits growth velocity (GV) assessed by centimeters/year (cm/year) in primarily prepubescent, mild asthmatics. However, several observational studies measuring normal growth variance by Z score suggest the absence of the ICS inhibitory effect.

Objective

To demonstrate the generalizability of ICS growth inhibition in cm/year by establishing whether this measure exceeds the expected normal changes in GV by Z score for similar age and sex.

Methods

This was a retrospective, observational study comparing height and GV across a 2 year period in asthmatics aged 2–10 years, receiving ICS therapy (Group 3) with non‐asthmatics, and non‐ICS asthmatics (Groups 1 and 2), respectively. Generalized linear model procedure compared GV measures after adjustment for age, gender, and dependence of group differences on the age of the child.

Results

Before initiation of ICS therapy at baseline, Group 3 patients (n = 22) were shorter than Groups 1 (n = 67) and 2 (n = 44) by mean height in cm, and height for age Z score in the adjusted model (p < .05). GV was also significantly reduced in Group 3 after initiation of ICS therapy versus Groups 1 and 2 by 1.0–1.5 cm/year, respectively, p < .05, but not significantly in comparison to expected normal GV variance determined by Z score, p ≥ .05.

Conclusion

Our findings suggest the need to consider normal growth variance by Z scores in addition to absolute changes (cm/year) when interpreting the inhibitory effect of ICS on GV. Larger sample size studies will be necessary to confirm our findings.
Frequency of ventilator circuit changes to prevent ventilator‐associated pneumonia in neonates and children—A systematic review and meta‐analysis
Authors: Abiramalatha Thangaraj , Ramaswamy Viraraghavan Vadakkencherry , Thanigainathan Sivam , Pullattayil Abdul Kareem , Kirubakaran Richard
Published: March 2021

Objective

To assess the effect of different frequencies of ventilator circuit changes in neonates and children through a systematic review and meta‐analysis.

Interventions

(1) “No routine change of ventilator circuit (unless visibly soiled)” versus “routine change at any fixed interval”; (2) routine change of circuit at “less frequent” versus “more frequent” intervals.

Outcomes

Primary outcomes were VAP rate (number of VAP episodes per 1000 ventilator‐days) and all‐cause mortality before discharge.

Methods

MEDLINE, CENTRAL, EMBASE, and CINAHL were systematically searched from inception till November 3, 2020. Two authors assessed trial eligibility and risk of bias, and independently extracted data. Data were synthesized using fixed effects model. GRADE was used to assess certainty of evidence (CoE).

Results

We identified six studies enrolling 768 participants evaluating circuit changes at two fixed intervals. Meta‐analysis of studies on circuit changes “once in less than 7 days” versus “once weekly” showed no difference in VAP rate (risk ratio: 0.83 [0.38–1.81]; one randomized controlled trial (RCT) and 0.94 [0.49–1.81]; two before‐after studies) or mortality before discharge (0.67 [0.34–1.3]; one RCT and 1.01 [0.63–1.64]; two before‐after studies). CoE was very low. Less frequent circuit changes reduced health‐care costs. No study evaluating “circuit changes only when visibly soiled” versus “circuit changes at a fixed interval” was identified.

Conclusion

There is no evidence to suggest that ventilator circuits can be safely left unchanged until visibly soiled in neonates and children. Extending circuit changes interval to “once weekly” may not increase VAP rate (CoE—very low) and reduces healthcare costs.
Stability of sputum inflammatory phenotypes in childhood asthma during stable and exacerbation phases
Authors: Tsang Yuk Ping , Marchant Julie M. , Li Albert M. , Chang Anne B.
Published: March 2021

Background

Management strategies based on airway inflammation phenotypes are increasingly used for adults with asthma. While sputum‐based phenotypes are relatively stable in adults with asthma, there is little such data in childhood asthma. Hence, we aimed to evaluate the stability of sputum inflammatory phenotypes in children with asthma both in the stable and during exacerbation phases.

Methods

Sputum cellularity data from two previous prospective studies involving children with asthma were re‐evaluated and categorized into two inflammatory phenotypes: eosinophilic (>2.5% eosinophils) and noneosinophilic (≤2.5% eosinophils). Baseline values and follow‐up sputum inflammatory phenotype classification were compared in children with asthma during stable and exacerbation phases.

Results

Thirteen of 32 children (41%) with stable asthma demonstrated a change in sputum inflammatory phenotype 8 weeks later. In a different second cohort, both sputum eosinophils and neutrophils percentages increased and peaked on Day 1 of asthma exacerbation, but compared with baseline, 22% (2/9) and 13% (1/8) of these children had their sputum phenotype categorization changed on Day 1 and Day 3 of exacerbation, respectively.

Conclusion

In children with asthma, sputum inflammatory phenotypes are variable in both stable and exacerbation phases, in contrast to data in adults.
Corticosteroids and pulmonary rehabilitation reducing long‐term morbidity in a patient with post‐COVID‐19 pneumonitis: A case study
Authors: Fanshawe Jack , Howell Jack , Omar Adhnan , Piper Megan , Simpson Thomas
Published: March 2021

Background

Whilst research efforts have focussed on treatment during the acute phase, little work has focussed on the long‐term sequelae of COVID‐19 infection. This case described a patient who remained symptomatic several weeks after discharge from hospital with what was diagnosed as a COVID‐19 infection. There were significant deficits shown in his functional exercise testing, his pulmonary functions testing and there was evidence of fibrotic changes on his radiology.

Methods

As part of a multidisciplinary clinic, he was started on steroids and a tailored pulmonary rehabilitation course over a course of 6–8 weeks. Thereafter, his exercise testing, pulmonary function tests and radiology were all repeated to see progress.

Results

On completing the course of corticosteroids and concurrent personalised pulmonary rehabilitation, there was a dramatic improvement in the patient's symptom severity, radiology and pulmonary function. The most significant improvement noted was in his exercise testing, namely a 6‐min walk test and 1 min of sit‐to‐stands. Before treatment, he had a Medical Reserch Council (MRC) score of 2, and after it returned to his baseline of 0.

Discussion

Using corticosteroids and exercise training that allowed quantitative evaluation throughout the stages of recovery was a valuable tool to gauge progress and response to treatment. These therapies present opportunity to prevent the development of irreversible pulmonary fibrosis that could prove to be a major breakthrough in reducing long‐term morbidity and improving the quality of life of those affected.
The symmetric designer protein Pizza as a scaffold for metal coordination
Authors: Vrancken Jeroen P. M. , Noguchi Hiroki , Zhang Kam Y. J. , Tame Jeremy R. H. , Voet Arnout R. D.
Published: March 2021

Symmetric proteins are currently of interest as they allow creation of larger assemblies and facilitate the incorporation of metal ions in the larger complexes. Recently this was demonstrated by the biomineralization of the cadmium‐chloride nanocrystal via the Pizza designer protein. However, the mechanism behind this formation remained unclear. Here, we set out to investigate the mechanism driving the formation of this nanocrystal via truncation, mutation, and circular permutations. In addition, the interaction of other biologically relevant metal ions with these symmetric proteins to form larger symmetric complexes was also studied. The formation of the initial nanocrystal is shown to originate from steric strain, where His 58 induces a different rotameric conformation on His 73, thereby distorting an otherwise perfect planar ring of alternating cadmium and chlorine ions, resulting in the smallest nanocrystal. Similar highly symmetric complexes were also observed for the other biological relevant metal ions. However, the flexibility of the coordinating histidine residues allows each metal ion to adopt its preferred geometry leading to either monomeric or dimeric β‐propeller units, where the metal ions are located at the interface between both propeller units. These results demonstrate that symmetric proteins are not only interesting to generate larger assemblies, but are also the perfect scaffold to create more complex metal based assemblies. Such metal protein assemblies may then find applications in bionanotechnology or biocatalysis.
Improved Wave Function Overlap and Carrier Confinement of AlGaN‐Based Deep‐Ultraviolet Light‐Emitting Diodes with Graded Composition Multiple Quantum Wells
Authors: Xiao Fu-an , Liang Xu , Liu Wen-jie , Hu Xiao-long
Published: March 2021

Herein, the electron–hole wave function overlaps as well as the carrier confinement are both improved by an inversely graded Al‐composition design in the multiple‐quantum‐well (MQW) active region of deep‐ultraviolet light‐emitting diodes (DUV–LEDs). Simulation results show that at a current of 250 mA, the light output power (LOP) of the DUV–LEDs with graded composition MQWs has achieved a remarkable enhancement of 38.7% as compared to that with conventional MQWs, and the efficiency droop is significantly reduced from 32.2% to 9.3%. The enhanced performance is attributed to the increased wave function overlap of the electrons and holes due to the alleviated polarization electric field. Furthermore, the depth of quantum wells (QWs) is increased by the increased polarization‐induced charges and results in a better carrier confinement in the well layers. In addition, the LOP is further enhanced by 20.5% and the efficiency droop is reduced to 6.2% by engineering the last quantum barrier in the graded MQWs, which is attributed to the further reduction in the electron leakage. The proposed structure provides a valuable guideline for the high‐efficiency DUV–LEDs.
Surface Engineering of 2D Carbon Nitride with Cobalt Sulfide Cocatalyst for Enhanced Photocatalytic Hydrogen Evolution
Authors: Zhou Min , Li Li , Zhang Sai , Yi Jianjian , Song Yanhua , Li Huaming , Xu Hui
Published: March 2021

It is a great challenge to design efficient noble‐metal‐free cocatalysts used in hydrogen production under visible light irradiation. Herein, it is demonstrated that a cobalt‐sulfide material (Co9S8) with the advantages of excellent functionality of charge transfer can be used as an effective cocatalyst to improve the photocatalytic hydrogen evolution of 2D graphitic carbon nitride (2D g‐C3N4). Interestingly, the developed CoNx bonds can strengthen the interface connection and ensure effective charge migration. Finally, the photocatalytic hydrogen evolution activity can be greatly improved. The optimal catalyst (20% Co9S8/2D g‐C3N4) shows 237.9 μmol hydrogen evolution at 5 h, which is 140 times that of 2D g‐C3N4. The good result indicates the positive role of the Co9S8 cocatalyst for active site engineering on 2D g‐C3N4.