bluuebunny/crossref_metadata_2025 huggingface dataset:
How do teens with a history of suicidal behavior and self‐harm interact with social media?
Authors: Szlyk Hannah S. , Li Xiao , Kasson Erin , Peoples JaNiene E. , Montayne Mandy , Kaiser Nina , Cavazos‐Rehg Patricia
Published: March 2023

Background

This study examines how engagement with depression‐related social media content varies by teens who report suicidal ideation, suicide attempts, and nonsuicidal self‐injury (NSSI) versus those who had not experienced each behavior.

Methods

Teens aged 15–17 years old (N = 93) were recruited from social media platforms from October 2016 to August 2018. Participants were asked three open‐ended questions about the advantages and disadvantages of networking about depression‐related content on social media. We conducted a qualitative analysis to capture themes in responses by question item. Univariate analyses were conducted to compare differences in the frequency of themes endorsed among the behavioral groups versus their counterparts.

Results

Among participants (female, 73%; non‐White, 45%; sexual minority, 57%), most (93%, n = 87) endorsed depressive symptoms. Sixty‐five percent (n = 60) endorsed suicidal ideation within the past year, who were more likely to indicate unhelpful social interactions (p = .02) as a disadvantage of following depression content than peers who did not endorse suicidal ideation within the past year. Eighty percent (n = 74) endorsed lifetime experience of NSSI, who were more likely to indicate negative impact on relationships (p = .01) from posting depression content than peers who did not experience NSSI. Fifty‐eight percent (n = 54) endorsed a lifetime suicide attempt, who were more likely to mention offering solutions (p = .03) to someone posting concerning content than peers who did not endorse a lifetime suicide attempt.

Conclusions

This study provides diverse and unique perspectives on how engagement with depression‐related social media varies by mental health behaviors and informs the use of social media for recruitment and outreach for teens.
Risk factors for perpetrating sexual aggression among adolescents: Differences by gender and sexual orientation
Authors: Hunter Julia , Bhuptani Prachi H. , Orchowski Lindsay M.
Published: March 2023

Although anyone—regardless of gender or sexual orientation—can perpetrate sexual aggression, most studies examining risk factors for engaging in sexual aggression include samples of boys and men, and do not consider the sexual orientation of the respondent. The current study addresses this gap in the literature by examining how risk factors for sexual aggression vary as a function of gender and sexual orientation in a sample of 1782 high school youth. Participants completed surveys evaluating engagement in consent behaviors, rape myth acceptance, perception of peer rape myth acceptance, perceived peer engagement in violence, and perceived peer support for violence. A one‐way MANOVA found that constructs varied as a function of gender and sexual orientation. Specifically, heterosexual boys reported lower engagement in consent behaviors, higher rape myth acceptance, and higher perceived peer support for violence compared to heterosexual girls and sexual minority girls. The results highlight the importance of considering gender and sexual orientation when designing sexual aggression prevention programs.
Molecular mechanisms of cancer cachexia‐related loss of skeletal muscle mass: data analysis from preclinical and clinical studies
Authors: Martin Agnès , Gallot Yann S. , Freyssenet Damien
Published: March 2023

Cancer cachexia is a systemic hypoanabolic and catabolic syndrome that diminishes the quality of life of cancer patients, decreases the efficiency of therapeutic strategies and ultimately contributes to decrease their lifespan. The depletion of skeletal muscle compartment, which represents the primary site of protein loss during cancer cachexia, is of very poor prognostic in cancer patients. In this review, we provide an extensive and comparative analysis of the molecular mechanisms involved in the regulation of skeletal muscle mass in human cachectic cancer patients and in animal models of cancer cachexia. We summarize data from preclinical and clinical studies investigating how the protein turnover is regulated in cachectic skeletal muscle and question to what extent the transcriptional and translational capacities, as well as the proteolytic capacity (ubiquitin–proteasome system, autophagy–lysosome system and calpains) of skeletal muscle are involved in the cachectic syndrome in human and animals. We also wonder how regulatory mechanisms such as insulin/IGF1–AKT–mTOR pathway, endoplasmic reticulum stress and unfolded protein response, oxidative stress, inflammation (cytokines and downstream IL1ß/TNFα–NF‐κB and IL6–JAK–STAT3 pathways), TGF‐ß signalling pathways (myostatin/activin A‐SMAD2/3 and BMP‐SMAD1/5/8 pathways), as well as glucocorticoid signalling, modulate skeletal muscle proteostasis in cachectic cancer patients and animals. Finally, a brief description of the effects of various therapeutic strategies in preclinical models is also provided. Differences in the molecular and biochemical responses of skeletal muscle to cancer cachexia between human and animals (protein turnover rates, regulation of ubiquitin‐proteasome system and myostatin/activin A‐SMAD2/3 signalling pathways) are highlighted and discussed. Identifying the various and intertwined mechanisms that are deregulated during cancer cachexia and understanding why they are decontrolled will provide therapeutic targets for the treatment of skeletal muscle wasting in cancer patients.
Epstein−Barr virus reactivation induces MYC‐IGH spatial proximity and t(8;14) in B cells
Authors: Sall Fatimata Bintou , Shmakova Anna , Karpukhina Anna , Tsfasman Tatyana , Lomov Nikolai , Canoy Reynand Jay , Boutboul David , Oksenhendler Eric , Toure Awa Oumar , Lipinski Marc , Wiels Joëlle , Germini Diego , Vassetzky Yegor
Published: March 2023

Burkitt lymphoma (BL) is a B cell malignancy associated with the Epstein−Barr virus (EBV). Most BL cases are characterized by a t(8;14) chromosomal translocation involving the MYC oncogene and the immunoglobulin heavy chain gene (IGH). The role of EBV in promoting this translocation remains largely unknown. Here we provide the experimental evidence that EBV reactivation from latency leads to an increase in the proximity between the MYC and IGH loci, otherwise located far away in the nuclear space both in B‐lymphoblastoid cell lines and in patients' B‐cells. Specific DNA damage within the MYC locus, followed by the MRE11‐dependent DNA repair plays a role in this process. Using a CRISPR/Cas9‐based B cell model to induce specific DNA double strand breaks in MYC and IGH loci, we have shown that the MYC‐IGH proximity induced by EBV reactivation leads to an increased t(8;14) translocation frequency.
The impact of mild hypercholesterolemia on injury repair in the rat patellar tendon
Authors: Waugh Charlie M. , Mousavizadeh Rouhollah , Lee Jenny , Screen Hazel R. C. , Scott Alexander
Published: March 2023

Hypercholesterolemia is associated with tendon pathology and injury prevalence. Lipids can accumulate in the tendon's extracellular spaces, which may disrupt its hierarchical structure and the tenocytes physicochemical environment. We hypothesized that the tendon's ability to repair after injury would be attenuated with elevated cholesterol levels, leading to inferior mechanical properties. Fifty wild‐type (sSD) and 50 apolipoprotein E knock‐out rats (ApoE−/−) were given a unilateral patellar tendon (PT) injury at 12 weeks old; the uninjured limb served as a control. Animals were euthanized at 3‐, 14,‐ or 42‐days postinjury and PT healing was investigated. ApoE−/− serum cholesterol was double that of SD rats (mean: 2.12 vs. 0.99 mg/mL, p < 0.001) and cholesterol level was related to the expression of several genes after injury; notably rats with higher cholesterol demonstrated a blunted inflammatory response. There was little physical evidence of tendon lipid content or differences in injury repair between groups, therefore we were not surprised that tendon mechanical or material properties did not differ between strains. The young age and the mild phenotype of our ApoE−/− rats might explain these findings. Hydroxyproline content was positively related to total blood cholesterol, but this result did not translate to observable biomechanical differences, perhaps due to the narrow range of cholesterol levels observed. Tendon inflammatory and healing activity is modulated at the mRNA level even with a mild hypercholesterolemia. These important initial impacts need to be investigated as they may contribute to the known consequences of cholesterol on tendons in humans.
Formosanin C suppresses cancer cell proliferation and migration by impeding autophagy machinery
Authors: Chu Man‐Ling , Lin Pei‐Wen , Liu Yu‐Wen , Wu Shan‐Ying , Lan Sheng‐Hui , Su Chun‐Li , Liu Hsiao‐Sheng
Published: March 2023

Formosanin C (FC) is a natural compound extracted from Paris formosana Hayata with anticancer activity. FC induces both autophagy and apoptosis in human lung cancer cells. FC‐induced depolarization of mitochondrial membrane potential (MMP) may trigger mitophagy. In this study, we clarified the effect of FC on autophagy, mitophagy, and the role of autophagy in FC‐related cell death and motility. We found FC caused the continuous increase of LC3 II (representing autophagosomes) from 24 to 72 h without degradation after treatment of lung and colon cancer cells, indicating that FC blocks autophagic progression. In addition, we confirmed that FC also induces early stage autophagic activity. Altogether, FC is not only an inducer but also a blocker of autophagy progression. Moreover, FC increased MMP accompanied by overexpression of COX IV (mitochondria marker) and phosphorylated Parkin (p‐Parkin, mitophagy marker) in lung cancer cells, but no colocalization of LC3 with COX IV or p‐Parkin was detected under confocal microscopy. Moreover, FC could not block CCCP (mitophagy inducer)‐induced mitophagy. These results imply that FC disrupts mitochondria dynamics in the treated cells, and the underlying mechanism deserves further exploration. Functional analysis reveals that FC suppresses cell proliferation and motility through apoptosis and EMT‐related pathway, respectively. In conclusion, FC acts as an inducer as well as a blocker of autophagy that results in cancer cell apoptosis and decreased motility. Our findings shed the light on the development of combined therapy with FC and clinical anticancer drugs for cancer treatment.
Effect of roots on the soil detachment process in grassland and shrubland
Authors: Ma Jianye , Ma Bo , Li Zhanbin , Wang Chenguang , Zhang Zeyu , Li Gui
Published: March 2023

Plant roots play an important role in reducing soil detachment and increasing soil erosion resistance. Current studies have mainly focused on the quantification of the soil detachment rate (SDR). However, few studies have been conducted to explore the variation in the SDR and root effects during the soil detachment process. In this study, undisturbed soil samples were collected from four shrublands (with the main species Caragana korshinskii, C. korshinskii mixed with Agropyron cristatum, C. korshinskii mixed with Bothriochloa ischaemum, and C. korshinskii mixed with Artemisia gmelinii) and three grasslands (with the main species B. ischaemum, B. ischaemum mixed with A. cristatum, and B. ischaemum mixed with A. gmelinii) on the Loess Plateau, China. The samples were subjected to flow scouring through hydraulic flume experiments under six different shear stresses. The duration of this experiment was 6 min, and the SDR of each minute was estimated. The results showed that the SDR of shrubland was higher than that of grassland in each detachment process. The dominant factors affecting SDR gradually changed from the root–soil composite properties to the hydrodynamic parameters in this process. The effect of roots on the SDR was stronger than that of soil properties in the root–soil composite. In the early detachment stage, the 0–2 mm fine roots had the strongest effect on the SDR, while it was affected by the combined effect of fine roots and coarse roots in the later stage. When the fibrous roots were mixed with the tap roots, the fibrous roots had a significant negative effect on the SDR and mainly affected the early detachment stage. However, the tap roots had a weak effect in all stages. With the detachment process, the soil erosion resistance first increased and then stabilized, and the variations were mainly concentrated from 0 to 3 min. The roots mainly affected the SDR and soil erosion resistance by influencing rill erodibility parameters.
Effect of the Grain‐for‐Green Program on forest fragmentation
Authors: Zhang Mei , Yu Shichuan , Ye Quanping , Li Zhen , Yin Daihao , Zhao Zhong
Published: March 2023

Fragmentation profoundly alters the character and pattern of forests, influencing biodiversity in the context of global climate change. Forest area density (FAD) is currently considered the most effective method for characterizing forest fragmentation. Therefore, reasonable and accurate quantification of FAD and its relationship with forest cover changes are essential for evaluating forest fragmentation in the Loess Plateau under the implementation of the Grain‐for‐Green Program (GGP). Based on land use/cover (LULC) in 1998–2022, we integrated the Random forest (RF) algorithm and the conversion of land use and its effects at small regional extent (CLUE‐S) model to derive LULC in 2030. Subsequently, we proposed a multi‐scale window threshold to evaluate forest fragmentation by constructing nonlinear models. Furthermore, we explored the relationship between FAD and forest cover changes by spatial regression models. The results are as follows: (1) in 1998–2030, the main conversion of LULC was of the cropland to broad‐leaf forests and grassland. (2) The 43 × 43 window served as the optimal multi‐scale threshold to assess forest fragmentation. (3) The GGP slowed down forest fragmentation. (4) The degree of fragmentation in broad‐leaf forests was higher than that in coniferous forests. (5) Spatial error model (SEM) was the most appropriate for establishing the spatial relationship between forest fragmentation and forest cover changes. In conclusion, since the implementation of the GGP, forest cover changes had a significant impact on forest fragmentation and its multi‐scale threshold. This research provides a basis for the reasonable configuration of land resources in the Loess Plateau and novel methods for studying forest cover changes and fragmentation.
Online Conversations for Equity, Action, and Networking: A Pilot Project Highlighting Diversity in the Ocean Sciences
Authors: Johanif Dira , Alemayehu Eden , Chan Tiffany , Nöel Erin , Santamaria Charles , Davis Shannon , Evensen K Garrett , Lillquist Jessica , Mabry Lee , Lockwood Lucy , Ploumi Konstantina Tania , Rosenthal Isaac , Roy Michael , San Antonio Christine , Sheldon Patrick , Luis Kelly
Published: March 2023

The onset of the COVID‐19 pandemic and the Black Lives Matter movement urged institutions to redress shortcomings in their diversity, equity, and inclusion goals and initiatives. The School for the Environment (SFE) at the University of Massachusetts Boston (UMass Boston), a public research minority serving university in the United States of America, responded to this call through launching the Online Conversations for Equity, Action, and Networking (OCEAN) program. This pilot project funded by Woods Hole Sea Grant aimed to amplify the voices of Black, Indigenous, and People of Color (BIPOC) in the marine sciences. A collective of SFE undergraduate and graduate students hosted virtual department seminars, undergraduate meet and greets, and podcast interviews for invited BIPOC speakers. Pre‐ and post‐surveys were developed to evaluate the efficacy and reach of the OCEAN programming and the results indicate that the program had an overall positive effect on the UMass Boston community. Ultimately, the OCEAN program provides an example for launching and evaluating virtual BIPOC science engagement and outreach initiatives.
Expanding the genetic spectrum of giant axonal neuropathy: Two novel variants in Iranian families
Authors: Ashrafi Mahmoud Reza , Dehnavi Ali Zare , Tavasoli Ali Reza , Heidari Morteza , Ghahvechi Akbari Masoud , Ronagh Ali Reza , Ghafouri Mohammad , Mahdieh Nejat , Mohammadi Pouria , Rezaei Zahra
Published: March 2023

Background

Giant axonal neuropathy (GAN) is a progressive childhood hereditary polyneuropathy that affects both the peripheral and central nervous systems. Disease‐causing variants in the gigaxonin gene (GAN) cause autosomal recessive giant axonal neuropathy. Facial weakness, nystagmus, scoliosis, kinky or curly hair, pyramidal and cerebellar signs, and sensory and motor axonal neuropathy are the main symptoms of this disorder. Here, we report two novel variants in the GAN gene from two unrelated Iranian families.

Methods

Clinical and imaging data of patients were recorded and evaluated, retrospectively. Whole‐exome sequencing (WES) was undertaken in order to detect disease‐causing variants in participants. Confirmation of a causative variant in all three patients and their parents was carried out using Sanger sequencing and segregation analysis. In addition, for comparing to our cases, we reviewed all relevant clinical data of previously published cases of GAN between the years 2013–2020.

Results

Three patients from two unrelated families were included. Using WES, we identified a novel nonsense variant [NM_022041.3:c.1162del (p.Leu388Ter)], in a 7‐year‐old boy of family 1, and a likely pathogenic missense variant [NM_022041.3:c.370T>A (p.Phe124Ile)], in two affected siblings of the family 2. Clinical examination revealed typical features of GAN‐1 in all three patients, including walking difficulties, ataxic gait, kinky hair, sensory‐motor polyneuropathy, and nonspecific neuroimaging abnormalities. Review of 63 previously reported cases of GAN indicated unique kinky hair, gait problem, hyporeflexia/areflexia, and sensory impairment were the most commonly reported clinical features.

Conclusions

One homozygous nonsense variant and one homozygous missense variant in the GAN gene were discovered for the first time in two unrelated Iranian families that expand the mutation spectrum of GAN. Imaging findings are nonspecific, but the electrophysiological study in addition to history is helpful to achieve the diagnosis. The molecular test confirms the diagnosis.
Delay differential equation model of forest biomass and competition between wood‐based industries and synthetic‐based industries
Authors: Dipesh  , Kumar Pankaj
Published: March 2023

Wood plays a very important role for daily household needs. In this paper, we have taken three parameters, forest biomass density
, wood‐based industries density
, and synthetic‐based industries density
in the proposed mathematical modeling. The forest biomass is assumed to grow logistically, which requires a fixed time to achieve full growth. The excessive cutting of wood for the growth of wood‐based industries not only depletes these forest resources, but there comes a delay in the growth of forest biomass as well. On the contrary, the growth of synthetic‐based industry is independent of forest biomass, yet there is a competition between wood‐based products and synthetic‐based products as per market demands. With the help of differential equation, we studied the stability of the system. Delay plays a significant role in the system to understand the complex behavior of the system about non‐zero equilibrium point. Hopf‐bifurcation observed and directional analysis is studied using normal form theory and manifold reduction. MATLAB software is used to graphical representation of the system.
Dynamical behavior of rotavirus epidemic model with non‐probabilistic uncertainty under Caputo–Fabrizio derivative
Authors: Jena Rajarama Mohan , Chakraverty Snehashish , Nisar Kottakkaran Sooppy
Published: March 2023

Rotavirus infection is also a major cause of death in babies and children. Rotavirus causes severe diarrhea in babies and infants in developed and underdeveloped countries. It has multiple types of transmission: human to human and human to the environment. This paper investigates the time‐fractional order rotavirus epidemic model in an uncertain environment defined in the Caputo–Fabrizio (CF) derivative sense. In the titled model, the initial conditions are considered as fuzzy numbers. A double parametric form (DPF) of fuzzy numbers has been used in the fuzzy fractional rotavirus model. A semi‐analytical approach called the homotopy perturbation Elzaki transform method (HPETM) has been employed to solve the present model with the fuzzy initial condition. In order to derive the existence and uniqueness of the solution of the model, the concept of fixed‐point theory is utilized. Various fuzzy and interval solutions have been computed by considering different values of fractional orders, fuzzy parameters, and parameters involved in the given model.
The role of tumor activation and inhibition with saturation effects in a mathematical model of tumor and immune system interactions undergoing oncolytic viral therapy
Authors: Vithanage G. V. R. K. , Wei Hsiu‐Chuan , Jang Sophia R‐J
Published: March 2023

We propose and study a mathematical model governing interactions between cancer and immune system with an oncolytic viral therapy (OVT), wherein cancer cells can activate and inhibit immune cells simultaneously with saturations. When the therapy is not applied, it is shown that the interaction can support at most three hyperbolic positive equilibria where two of them are always asymptotically stable and the other is a saddle point. The reachable stable tumor burden can be either small or large depending on initial tumor size. We analyze the full model by proving global asymptotic stability of the virus‐free equilibrium that corresponds to OVT failure. Sufficient conditions based on model parameters are derived under which the model is uniformly persistent. The proposed system is validated using a mouse model of human pancreatic cancer carried out by Koujima et al. Global sensitivity analysis indicates that the rates of tumor‐mediated killing and immune cell exhaustion are critical for tumor progression and therapy success. Numerical bifurcation analysis reveals that the saddle point can be utilized to estimate the maximum tumor load for eradication by OVT. Moreover, an immunosuppressive microenvironment may enhance viral therapy efficacy.
On optimally solving sub‐tree scheduling for wireless sensor networks with partial coverage: A branch‐and‐cut algorithm
Authors: Bianchessi Nicola
Published: March 2023

Given a wireless sensor network, we consider the problem to minimize its total energy consumption over consecutive time slots with respect to communication activities. Nonempty and disjoint subsets of nodes are required to be active and connected under a tree topology configuration in the different time slots, and each network node must be active in a unique time slot. Moreover, the power required by the same pair of network nodes to communicate on the associated direct channel may vary in the different time slots. The problem has been recently introduced in the literature under the name Sub‐Tree Scheduling for Wireless Sensor Networks with Partial Coverage. We focus on the exact solution of the problem. We present a branch‐and‐cut (BC) algorithm based on a novel integer linear programming formulation which allows avoiding the introduction of symmetries in the solution space. In particular, the algorithm relies on an efficient and nontypical separation algorithm for known valid inequalities, and on an easy‐to‐implement primal bound heuristic. The effectiveness of the BC algorithm is empirically shown through an extensive experimental analysis involving 300 newly generated benchmark instances with up to 200 network nodes and 8 time slots. Additionally, the experimental results show that the BC algorithm represents a valid computational tool to benchmark the performance of heuristics addressing the problem, and can be used in practice, as an heuristic solver, to tackle problem instances that are not too large.
Racial/ethnic disparities in sleep‐disordered breathing during pregnancy in the nuMoM2b study
Authors: Lucchini Maristella , Rayport Yael , Valeri Linda , Jelic Sanja , St‐Onge Marie‐Pierre , O'Brien Louise M. , Alcantara Carmela
Published: March 2023

Objective

The aim of this study was to assess the prevalence and severity of sleep‐disordered breathing (SDB) across racial/ethnic groups in 3702 pregnant people at 6 to 15 and 22 to 31 weeks gestational age, examine whether BMI modifies the association between race/ethnicity and SDB, and investigate whether interventions to reduce weight might reduce racial/ethnic disparities in SDB.

Methods

Differences by race/ethnicity in SDB prevalence and severity were quantified via linear, logistic, or quasi‐Poisson regression. Controlled direct effect was used to estimate whether intervening on BMI would remove/diminish differences by race/ethnicity in SDB severity.

Results

This study comprised 61.2% non‐Hispanic White (nHW), 11.9% non‐Hispanic Black (nHB), 18.5% Hispanic, and 3.7% Asian people. SDB prevalence was higher for nHB compared with nHW pregnant people at 6 to 15 weeks (odds ratio [OR] 1.81, 95% CI [1.07, 2.97]), whereas at 21 to 32 weeks, Asian pregnant people had a higher SDB prevalence than nHW (OR 2.2, 95% CI [1.1, 4.0]). The severity of SDB differed across racial/ethnic groups in early pregnancy, with nHB pregnant people having a higher apnea‐hypopnea index (AHI) (OR 1.35, 95% CI [1.07, 1.69]) compared with nHW. Having overweight/obesity was associated with a higher AHI (β = 2.36, 95% CI [1.97, 2.84]). Controlled direct effect analyses indicated that in early pregnancy, nHB and Hispanic pregnant people would have a lower AHI compared with nHW people had they had normal weight.

Conclusions

This study extends knowledge on racial/ethnic disparities in SDB to a pregnant population.
Incidence of ultrasonographic signs of pneumothorax in asymptomatic neonates
Authors: Montero Gato Jon , Sacristán Pablo Andrés , Vázquez Nerea López , Martín Mónica de las Heras , Amorós Ana Gutiérrez , Fernández Lorena Rodeño
Published: March 2023

Introduction

Pneumothorax in neonates can be life‐threatening. In neonates without respiratory distress, spontaneous pneumothorax can also develop under certain conditions.

Objectives

To determine the incidence of ultrasonographic signs of pneumothorax in asymptomatic neonates using lung ultrasound as the diagnostic tool.

Methods

This was an observational prospective study conducted at the Basurto University Hospital (Bilbao, Spain) between January 2018 and December 2020. Lung ultrasound was performed during routine examination of asymptomatic neonates admitted to the maternity ward.

Results

Of a total of 204 asymptomatic neonates included in the study, 21 (10.3%) presented ultrasound signs of pneumothorax (Group A), and 183 (89.7%) had a normal lung ultrasound (Group B). Lung ultrasound was performed after a mean of 19 h of life (range 9–34). The presence of A‐lines behind the sternum in the anterior transverse plane, at the intermammillary level, was observed in 100% of patients in Group A compared to no cases in Group B (p < 0.0001). The neonates of Group A presented the lung point located in the midclavicular line, indicative of a mild air leak.

Conclusions

Lung ultrasound allows precise detection of suspected small‐sized air leaks that can be detected in asymptomatic neonates. The true incidence of pneumothorax in asymptomatic neonates may be substantially higher than previously described in the literature.
Burning characteristics of ammonium nitrate propellant containing fine ammonium perchlorate – influence of porosity of ammonium perchlorate**
Authors: Tsuchiya Hironori , Togashi Ryoto , Kohga Makoto
Published: March 2023

Fine porous ammonium perchlorate (PAP) has small holes in its crust, and the voids in the particles are connected to the outside. The porosity of PAP results in fine bubble contamination in a propellant because the voids in PAP cannot be completely charged with a binder. Fine bubble contamination can improve the burning rate characteristics of an ammonium perchlorate (AP) propellant. The influence of the porosity of PAP on the burning characteristics of an ammonium nitrate (AN)/AP propellant and the effect of Fe2O3 as a catalyst on them were investigated in this study. The void fraction of the propellant increased with increasing mass ratio between AP and all oxidizers (ξ) and ranged from 1.3 % to 3.2 %. The porosity of PAP increased the burning rate of AN/AP propellants. This effect increased with decreasing pressure and was independent of ξ. However, porosity had minimal influence on the burning rate of AN/AP propellants with Fe2O3. The effect of the catalyst on the increase in the burning rate due to the porosity of PAP was influenced by pressure and ξ. The effect on the AN/AP propellant was greatest when ξ was in the 0.5–0.6 range.
Deriving mechanism‐based pharmacodynamic models by reducing quantitative systems pharmacology models: An application to warfarin
Authors: Falkenhagen Undine , Knöchel Jane , Kloft Charlotte , Huisinga Wilhelm
Published: March 2023

Quantitative systems pharmacology (QSP) models integrate comprehensive qualitative and quantitative knowledge about pharmacologically relevant processes. We previously proposed a first approach to leverage the knowledge in QSP models to derive simpler, mechanism‐based pharmacodynamic (PD) models. Their complexity, however, is typically still too large to be used in the population analysis of clinical data. Here, we extend the approach beyond state reduction to also include the simplification of reaction rates, elimination of reactions, and analytic solutions. We additionally ensure that the reduced model maintains a prespecified approximation quality not only for a reference individual but also for a diverse virtual population. We illustrate the extended approach for the warfarin effect on blood coagulation. Using the model‐reduction approach, we derive a novel small‐scale warfarin/international normalized ratio model and demonstrate its suitability for biomarker identification. Due to the systematic nature of the approach in comparison with empirical model building, the proposed model‐reduction algorithm provides an improved rationale to build PD models also from QSP models in other applications.
Electrical Characteristics of Gated Anode Diodes Based on Normally Off Recessed‐Gate GaN High‐Electron‐Mobility Transistors for Rectenna Applications
Authors: Takahashi Hidemasa , Ando Yuji , Tsuchiya Yoichi , Wakejima Akio , Suda Jun
Published: March 2023

AlGaN/GaN high‐electron‐mobility transistor (HEMT)‐based gated‐anode diodes (GADs) for a 5.8 GHz rectenna application are proposed. An anode of the GAD is formed by connecting a gate and a drain of a normally off GaN HEMT. Herein, a wide recessed HEMT structure reported in the previous article is modified to a buried‐type recessed gate HEMT structure. The gate‐to‐cathode distance is optimized to maximize device performance. Typical direct current (DC) characteristics of the HEMTs are a threshold voltage (Vth) of +0.4 V and a maximum drain current (Imax) of 450 mA mm−1. GADs using the HEMTs show the characteristics of maximum forward current (If) of 600 mA mm−1and reverse breakdown voltage (BVr) of more than 100 V. The GAD using the recessed gate structure HEMT is shown to significantly improveIfandBVrsimultaneously compared to the previous work using the wide recessed gate structure. The rectifying performance of a bridge‐type rectifier simulated with SPICE model of the GAD shows radio frequency (RF)–DC conversion efficiency of 84% and RF input power of 13 W at 5.8 GHz using four GADs with each gate width (Wg) of 400 μm.
Aloe‐emodin targets multiple signaling pathways by blocking ubiquitin‐mediated degradation of DUSP1 in nasopharyngeal carcinoma cells
Authors: Chen Shanlin , Guan Xiaoxue , Xie Lei , Liu Chuanyu , Li Chunhong , He Min , Hu Jiahua , Fan Hui , Li Quanwen , Xie Liuping , Yang Mingqing , Zhang Xiaoling , Xiao Shengjun , Tang Jianhong
Published: March 2023

Aloe‐emodin (AE) has been shown to inhibit the proliferation of several cancer cell lines, including human nasopharyngeal carcinoma (NPC) cell lines. In this study, we confirmed that AE inhibited malignant biological behaviors, including cell viability, abnormal proliferation, apoptosis, and migration of NPC cells. Western blotting analysis revealed that AE upregulated the expression of DUSP1, an endogenous inhibitor of multiple cancer‐associated signaling pathways, resulting in blockage of the extracellular signal‐regulated kinase (ERK)‐1/2, protein kinase B (AKT), and p38‐mitogen activated protein kinase（p38‐MAPK） signaling pathways in NPC cell lines. Moreover, the selective inhibitor of DUSP1, BCI‐hydrochloride, partially reversed the AE‐induced cytotoxicity and blocked the aforementioned signaling pathways in NPC cells. In addition, the binding between AE and DUSP1 was predicted via molecular docking analysis using AutoDock‐Vina software and further verified via a microscale thermophoresis assay. The binding amino acid residues were adjacent to the predicted ubiquitination site (Lys192) of DUSP1. Immunoprecipitation with the ubiquitin antibody, ubiquitinated DUSP1 was shown to be upregulated by AE. Our findings revealed that AE can stabilize DUSP1 by blocking its ubiquitin–proteasome‐mediated degradation and proposed an underlying mechanism by which AE‐upregulated DUSP1 may potentially target multiple pathways in NPC cells.
The state of human papillomavirus research in Africa
Authors: Kanmodi Kehinde Kazeem , Egbedina Eyinade Adeduntan , Amzat Jimoh , Aminu Kafayat , Nnyanzi Lawrence Achilles
Published: March 2023

Background

Human papillomavirus (HPV) research scholarship evaluation is pivotal to the strategic planning, implementation and sustainability of HPV prevention and control programmes in Africa. Hence, this study evaluated HPV research scholarship in Africa.

Methods

This review—a bibliometric analysis—investigated the trends, patterns, dynamics and funding of HPV‐related literature production in Africa with a focus on the inequalities existing across thematic and subject areas, researchers, institutions and countries/territories/dependencies. The study data were obtained from SCOPUS database and analysed using the Microsoft Excel 2021 software.

Result

From 1974 (inception year) till 16 July 2022, a total of 2587 SCOPUS‐indexed literature on HPV were produced by African authors, with an average production rate of 50.5 publications per year (1974–2021). A few publications (1.2%) were in the Social Sciences. Most (95.1%) publications were in English, only a few (3.9%) were in French, whereas none was in Arabic, Portuguese, Spanish, Swahili or any other official language of the African Union. South Africa, Nigeria and Egypt were the three most prolific African countries. The 10 most prolific researchers were affiliated to public institutions in South Africa, Tanzania and Botswana. The top 10 funding sponsors were public institutions in the United States, the United Kingdom, Belgium and South Africa. Moreover, researchers and institutions affiliated to South Africa, Nigeria, Kenya and Uganda were the predominant beneficiaries. Only two indigenous journals made the list of top 10 journals publishing HPV research outputs from Africa.

Conclusion

Scholarly HPV research productivity in Africa is very low and worsened by multiple inequality gaps. There is an urgent need for equitably strengthening HPV research capacity in Africa.
An improved adaptive EWMA control chart for monitoring time between events with application in health sector
Authors: Aslam Muhammad , Khan Majid , Rasheed Zahid , Anwar Syed Masroor , Abbasi Saddam Akber
Published: March 2023

Nonconforming events rarely occur in high‐quality processes, and the time between events () is likely to be followed by a skewed distribution, such as an exponential distribution. This paper proposes the upper and lower‐sided improved adaptive exponentially weighted moving control charts for monitoring data modeled by the exponential distribution. The proposed control charts are labeled as control charts, that is, the and control chart, respectively. The control chart detects the upward shifts, while the control chart identifies the downward shifts in the process. The Monte Carlo simulations are used to approximate the run length distribution of the proposed control charts. Numerical results associated with various performance measures, such as average run length (), standard run length (), median run length (), extra quadratic loss (), relative average run length (), and performance comparison index () are computed. The proposed control charts compared to the respective existing control charts, such as , , , and control charts, at a single shift, as well as over a specified range of shifts. The comparison reveals that the proposed control charts outperform the existing control charts for both single specified shifts and over a certain range of shifts. Finally, real‐life data of hospital stay time for male patients with traumatic brain injury are analyzed for the applicability of the control chart in the health sector.
Who gets public goods? Effects of ethnic diversity and exclusion on urban and rural populations' access to water and sanitation
Authors: Jadoon Amira , Khalid Hina , Fox Ashley
Published: March 2023

Why do some countries provide better access to life‐saving public goods than others? An enduring explanation from the political economy literature points to ethnic heterogeneity in impeding public goods provision. However, previous studies have not examined how the “diversity deficit” directly affects access to improved water and sanitation, a leading cause of continued under‐5 mortality globally, and how this effect varies for urban versus rural communities. Using cross‐sectional time series analysis of 149 low and middle‐income countries between 1990 and 2013, this study explores the relationship between national ethnic diversity and ethnic‐based political exclusion, and rural and urban populations’ access to water and sanitation. We find that ethnic diversity rather than ethnic exclusion predicts lower access to water and sanitation, although more so for rural populations, and that this relationship may be the most pronounced in South Asia and sub‐Saharan Africa. This suggests that the negative impact of diversity rooted in coordination problems may be rooted at the national level for goods that require both long‐term investment and ongoing resources. Our findings provide a more nuanced understanding of how national‐level ethnic diversity can exert divergent effects on the provision of public goods to rural versus urban populations, while also highlighting regional variation.
Paying for nature‐based solutions: A review of funding and financing mechanisms for ecosystem services and their impacts on social equity
Authors: Thompson Austin , Bunds Kyle , Larson Lincoln , Cutts Bethany , Hipp J. Aaron
Published: March 2023

Funding and financing challenges remain a persistent barrier to implementing nature‐based solutions that enhance ecosystem services, facilitate adaptation to climate change, and combat environmental stressors in cities. In the absence of adequate public financial resources, private funds are often expected to fill the gap. But market‐driven, nature‐based solutions can contribute to an inequitable distribution of urban ecosystem services by focusing on net benefits provided by nature. To help foster sustainable development and ensure that nature‐based solutions reach diverse and historically marginalized populations and communities, this scoping review explores the ecosystem services provided by nature‐based solutions and the payment mechanisms that produce and maintain them, focusing on literature on the United States. Findings suggest that the net benefits provided by nature‐based solutions and the available payment mechanisms vary based on the solution utilized (e.g., urban trees, parks, community gardens). Further, the distribution of benefits from nature‐based solutions is influenced by local historical, cultural, political, economic, and environmental contexts, the voices included in decision‐making, and the payment mechanisms used. Inspired by social equity principles, we present a framework for ecosystem service provision that is sensitive to market‐driven funding, financing, and partnerships. Practitioners can use this framework to assess whether payment schemes work in tandem with place (the local context) and process (governance and planning approaches) to ameliorate or exacerbate disparities in nature‐based solutions and the benefits they provide to people.
Confidence intervals for prevalence estimates from complex surveys with imperfect assays
Authors: Bayer Damon M. , Fay Michael P. , Graubard Barry I.
Published: March 2023

There are established methods for estimating disease prevalence with associated confidence intervals for complex surveys with perfect assays, or simple random sample surveys with imperfect assays. We develop and study methods for the complicated case of complex surveys with imperfect assays. The new methods use the melding method to combine gamma intervals for directly standardized rates and established adjustments for imperfect assays by estimating sensitivity and specificity. One of the new methods appears to have at least nominal coverage in all simulated scenarios. We compare our new methods to established methods in special cases (complex surveys with perfect assays or simple surveys with imperfect assays). In some simulations, our methods appear to guarantee coverage, while competing methods have much lower than nominal coverage, especially when overall prevalence is very low. In other settings, our methods are shown to have higher than nominal coverage. We apply our method to a seroprevalence survey of SARS‐CoV‐2 in undiagnosed adults in the United States between May and July 2020.
Non‐Symmetrical Tetraaryl‐α‐Diimines via Transimination: A Promising Route for Non‐Symmetrical 1,3,4,5‐Tetraarylimidazolium Chlorides
Authors: Joy Bony P. , Paul Sudeep , Sethy Sandhyarani , Gudimetla Vittal B.
Published: March 2023

A single step approach for the synthesis of non‐symmetrical tetraaryl‐α‐diimines via the transimination route at room temperature was developed. The reported procedure was found to be an elegant route for making non‐symmetrical tetraaryl‐α‐diimines, which upon cyclization yields a series of new non‐symmetrical 1,3,4,5‐tetraarylimidazolium chlorides, as stable N‐heterocyclic carbene (NHC) precursors.
Thermodynamic and Kinetic Studies of the Activities of Aldehydic C−H Bonds toward Their H‐Atom Transfer Reactions
Authors: Fu Yan‐Hua , Wang Fang , Zhao Ling , Zhang Yanwei , Shen Guang‐Bin , Zhu Xiao‐Qing
Published: March 2023

Aldehydes can not only accept hydrogen atoms to be reduced to alcohols, showing their oxidation properties; but also can donate hydrogen atoms of the C(sp2)−H bonds as hydrogen atom donors, showing their reduction properties. In this article, the hydrogen atom transfer reactions of eight aldehydes and free radicals in acetonitrile at 298 K were studied. The thermo‐kinetic parameters ΔG≠°(XH) of C(sp2)−H bonds in aldehydes were obtained by ΔG≠XH/Y=ΔG≠°(XH)+ΔG≠°(Y) as the ΔG≠°(Y) of free radicals were available in our previous work. The bond dissociation free energies ΔGo(XH) of C(sp2)−H bonds were calculated by iBonD HM method. The intrinsic resistance energies ΔG≠XH/X were determined as the ΔG≠°(XH) and ΔGo(XH) were available. ΔGo(XH), ΔG≠XH/X, and ΔG≠°(XH) were used to access the H‐donating abilities of C(sp2)−H bonds in aldehydes in thermodynamics, kinetics and actual HAT reactions. The scales and the effect of the structures of aldehydes on ΔGo(XH), ΔG≠XH/X, and ΔG≠°(XH) were discussed carefully. The oxidizing and reducing abilities of aldehydes, and the comparison of H‐donating abilities between C(sp2)−H of aldehydes with C(sp3)−H of the corresponding alcohols were also researched in detail. This paper not only fills the gap in the study of H‐donating activities of aldehydic C−H bonds, but also provides data support for the design and synthesis of more C(sp2)−H type antioxidants.
High Resolution Membrane Structures within Hybrid Lipid‐Polymer Vesicles Revealed by Combining X‐Ray Scattering and Electron Microscopy
Authors: Seneviratne Rashmi , Coates Georgina , Xu Zexi , Cornell Caitlin E. , Thompson Rebecca F. , Sadeghpour Amin , Maskell Daniel P. , Jeuken Lars J. C. , Rappolt Michael , Beales Paul A.
Published: March 2023

Hybrid vesicles consisting of phospholipids and block‐copolymers are increasingly finding applications in science and technology. Herein, small angle X‐ray scattering (SAXS) and cryo‐electron tomography (cryo‐ET) are used to obtain detailed structural information about hybrid vesicles with different ratios of 1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphocholine (POPC) and poly(1,2‐butadiene‐block‐ethylene oxide) (PBd22‐PEO14, Ms = 1800 g mol−1). Using single particle analysis (SPA) the authors are able to further interpret the information gained from SAXS and cryo‐ET experiments, showing that increasing PBd22‐PEO14 mole fraction increases the membrane thickness from 52 Å for a pure lipid system to 97 Å for pure PBd22‐PEO14 vesicles. Two vesicle populations with different membrane thicknesses in hybrid vesicle samples are found. As these lipids and polymers are reported to homogeneously mix, bistability is inferred between weak and strong interdigitation regimes of PBd22‐PEO14 within the hybrid membranes. It is hypothesized that membranes of intermediate structure are not energetically favorable. Therefore, each vesicle exists in one of these two membrane structures, which are assumed to have comparable free energies. The authors conclude that, by combining biophysical methods, accurate determination of the influence of composition on the structural properties of hybrid membranes is achieved, revealing that two distinct membranes structures can coexist in homogeneously mixed lipid‐polymer hybrid vesicles.
Engineering Single Cu Sites into Covalent Organic Framework for Selective Photocatalytic CO2 Reduction
Authors: Zhang Yize , Cao Lili , Bai Guoyi , Lan Xingwang
Published: March 2023

Photocatalytic CO2 conversion into value‐added chemicals is a promising route but remains challenging due to poor product selectivity. Covalent organic frameworks (COFs) as an emerging class of porous materials are considered as promising candidates for photocatalysis. Incorporating metallic sites into COF is a successful strategy to realize high photocatalytic activities. Herein, 2,2′‐bipyridine‐based COF bearing non‐noble single Cu sites is fabricated by chelating coordination of dipyridyl units for photocatalytic CO2 reduction. The coordinated single Cu sites not only significantly enhance light harvesting and accelerate electron–hole separation but also provide adsorption and activation sites for CO2 molecules. As a proof of concept, the Cu‐Bpy‐COF as a representative catalyst exhibits superior photocatalytic activity for reducing CO2 to CO and CH4 without photosensitizer, and impressively, the product selectivity of CO and CH4 can be readily modulated only by changing reaction media. Experimental and theoretical results reveal the crucial role of single Cu sites in promoting photoinduced charge separation and solvent effect in regulating product selectivity, which provides an important sight onto the design of COF photocatalysts for selective CO2 photoreduction.