bluuebunny/crossref_metadata_2025 huggingface dataset:
Neurochemical and Cognitive Beneficial Effects of Moderate Physical Activity and Catechin in Aged Rats
Authors: Ramis Margarita R. , Sarubbo Fiorella , Moranta David , Tejada Silvia , Lladó Jerònia , Miralles Antoni , Esteban Susana
Published: April 2021

A healthy aging process is a requirement for good life quality. A relationship between physical activity, the consumption of antioxidants and brain health has been stablished via the activation of pathways that reduce the harmful effects of oxidative stress, by inducing enzymes such as SIRT1, which is a protector of brain function. We analyzed the cognitive and neurochemical effects of applying physical exercise in elderly rats, alone or in combination with the antioxidant catechin. Several tests of spatial and episodic memory and motor coordination were evaluated. In addition, brain monoaminergic neurotransmitters and SIRT1 protein levels were assessed in the brains of the same rats. The results show that physical activity by itself improved age-related memory and learning deficits, correlating with the restoration of brain monoaminergic neurotransmitters and SIRT1 protein levels in the hippocampus. The administration of the antioxidant catechin along with the exercise program enhanced further the monoaminergic pathways, but not the other parameters studied. These results agree with previous reports revealing a neuroprotective effect of physical activity, probably based on its ability to improve the redox status of the brain, demonstrating that exercise at an advanced age, combined with the consumption of antioxidants, could produce favorable effects in terms of brain health.
Contribution of Adipose Tissue Oxidative Stress to Obesity-Associated Diabetes Risk and Ethnic Differences: Focus on Women of African Ancestry
Authors: Nono Nankam Pamela A. , Nguelefack Télesphore B. , Goedecke Julia H. , Blüher Matthias
Published: April 2021

Adipose tissue (AT) storage capacity is central in the maintenance of whole-body homeostasis, especially in obesity states. However, sustained nutrients overflow may dysregulate this function resulting in adipocytes hypertrophy, AT hypoxia, inflammation and oxidative stress. Systemic inflammation may also contribute to the disruption of AT redox equilibrium. AT and systemic oxidative stress have been involved in the development of obesity-associated insulin resistance (IR) and type 2 diabetes (T2D) through several mechanisms. Interestingly, fat accumulation, body fat distribution and the degree of how adiposity translates into cardio-metabolic diseases differ between ethnicities. Populations of African ancestry have a higher prevalence of obesity and higher T2D risk than populations of European ancestry, mainly driven by higher rates among African women. Considering the reported ethnic-specific differences in AT distribution and function and higher levels of systemic oxidative stress markers, oxidative stress is a potential contributor to the higher susceptibility for metabolic diseases in African women. This review summarizes existing evidence supporting this hypothesis while acknowledging a lack of data on AT oxidative stress in relation to IR in Africans, and the potential influence of other ethnicity-related modulators (e.g., genetic-environment interplay, socioeconomic factors) for consideration in future studies with different ethnicities.
Glycerol Improves Intracerebral Hemorrhagic Brain Injury and Associated Kidney Dysfunction in Rats
Authors: Chang Cheng-Yi , Pan Ping-Ho , Li Jian-Ri , Ou Yen-Chuan , Liao Su-Lan , Chen Wen-Ying , Kuan Yu-Hsiang , Chen Chun-Jung
Published: April 2021

In stroke patients, the development of acute kidney injury (AKI) is closely linked with worse outcomes and increased mortality. In this study, the interplay between post-stroke and AKI and treatment options was investigated in a rodent model of hemorrhagic stroke. Intrastriatal collagenase injection for 24 h caused neurological deficits, hematoma formation, brain edema, apoptosis, blood–brain barrier disruption, oxidative stress, and neuroinflammation in Sprague Dawley rats. Elevation of serum blood urea nitrogen, serum creatinine, urine cytokine-induced neutrophil chemoattractant-1, and urine Malondialdehyde, as well as moderate histological abnormality in the kidney near the glomerulus, indicated evidence of kidney dysfunction. The accumulation of podocalyxin DNA in urine further suggested a detachment of podocytes and structural deterioration of the glomerulus. Circulating levels of stress hormones, such as epinephrine, norepinephrine, corticosterone, and angiotensin II were elevated in rats with intracerebral hemorrhage. Osmotic agent glycerol held promising effects in alleviating post-stroke brain injury and kidney dysfunction. Although the detailed protective mechanisms of glycerol have yet to be determined, the intrastriatal collagenase injection hemorrhagic stroke model in rats allowed us to demonstrate the functional and structural integrity of glomerulus are targets that are vulnerable to post-stroke injury and stress hormones could be surrogates of remote communications.
Effects of Lithium Chloride and Nitric Oxide Inhibitor on Orthodontic Tooth Movement in the Rat
Authors: Talebian Reza , Jafari Farhad , Dehpour Ahmad Reza , Gruber Reinhard
Published: April 2021

Orthodontic tooth movement in a rodent model is reduced by lithium chloride (LiCl), a mood-stabilizing agent with antithyroid effects. Considering the established inhibitory effect of N(omega)-nitro-L-arginine methyl ester (L-NAME) on orthodontic tooth movement and the possible role of nitric oxide synthase in LiCl mechanism of action, the question arises if these two mechanisms are synergistic. To answer this question, 70 male Sprague Dawley rats were randomly divided into seven groups: untreated group without any interventions (i), and the orthodontic tooth movement groups receiving daily saline injection (ii), 300 (iii), and 600 mg/kg (iv) of LiCl per os, 10 mg/kg of L-NAME (v) and the combinations of 300 (vi) and 600 mg/kg LiCl (vii) with L-NAME. The first molar was moved towards the incisor with 60 g of mesial tipping force applied by an activated fixed coil spring for two weeks. The resulted distance between the first and the second molar was measured using a feeler gauge. The serum parameters were also determined. We report here that both concentrations of LiCl significantly decreased tooth movement. Even though L-NAME was capable of reducing orthodontic tooth movement, no synergistic effects with LiCl were observed. Moreover, L-NAME had no impact on the robust and significant increase of thyroid-stimulating hormone (TSH) and decrease of triiodothyronine (T3) and thyroxine (T4) in the LiCl treated rats. These findings suggest LiCl significantly decreases the orthodontic tooth movement in rats; however, this ability seems not to be principally mediated through nitric oxide synthase.
Resilience Assessment for the Northern Sea Route Based on a Fuzzy Bayesian Network
Authors: Qiao Weiliang , Ma Xiaoxue , Liu Yang , Lan He
Published: April 2021

The safety level of the northern sea route (NSR) is a common concern for the related stakeholders. To address the risks triggered by disruptions initiating from the harsh environment and human factors, a comprehensive framework is proposed based on the perspective of resilience. Notably, the resilience of NSR is decomposed into three capacities, namely, the absorptive capacity, adaptive capacity, and restorative capacity. Moreover, the disruptions to the resilience are identified. Then, a Bayesian network (BN) model is established to quantify resilience, and the prior probabilities of parent nodes and conditional probability table for the network are obtained by fuzzy theory and expert elicitation. Finally, the developed Bayesian networkBN model is simulated to analyze the resilience level of the NSR by back propagation, sensitivity analysis, and information entropy analysis. The general interpretation of these analyses indicates that the emergency response, ice-breaking capacity, and rescue and anti-pollution facilities are the critical factors that contribute to the resilience of the NSR. Good knowledge of the absorptive capacity is the most effective way to reduce the uncertainty of NSR resilience. The present study provides a resilience perspective to understand the safety issues associated with the NSR, which can be seen as the main innovation of this work.
Design and Evaluation of Large-Scale IoT-Enabled Healthcare Architecture
Authors: Said Omar , Tolba Amr
Published: April 2021

Employment of the Internet of Things (IoT) technology in the healthcare field can contribute to recruiting heterogeneous medical devices and creating smart cooperation between them. This cooperation leads to an increase in the efficiency of the entire medical system, thus accelerating the diagnosis and curing of patients, in general, and rescuing critical cases in particular. In this paper, a large-scale IoT-enabled healthcare architecture is proposed. To achieve a wide range of communication between healthcare devices, not only are Internet coverage tools utilized but also satellites and high-altitude platforms (HAPs). In addition, the clustering idea is applied in the proposed architecture to facilitate its management. Moreover, healthcare data are prioritized into several levels of importance. Finally, NS3 is used to measure the performance of the proposed IoT-enabled healthcare architecture. The performance metrics are delay, energy consumption, packet loss, coverage tool usage, throughput, percentage of served users, and percentage of each exchanged data type. The simulation results demonstrate that the proposed IoT-enabled healthcare architecture outperforms the traditional healthcare architecture.
A Transformer-Less Buck-Boost Grid-Tied Inverter with Low Leakage-Current and High Voltage-Gain
Authors: Chang Chien-Hsuan , Chen Yi-Fan
Published: April 2021

To improve the efficiency of photovoltaic (PV) grid-tied systems and simplify the circuit structure, many pseudo DC-link inverters have been proposed by combining a sinusoidal pulse-width modulation (SPWM) controlled buck-boost converter and a low-frequency polarity unfolder. However, due to the non-ideal characteristics of power diodes, the voltage-gain of a buck-boost converter is limited. To meet the needs of grid-connected systems with low input voltage and 220 Vrms utility, this paper uses two two-switch buck-boost converters with coupled inductors to develop a transformer-less buck-boost grid-tied inverter with low leakage-current and high voltage-gain. The proposed inverter is charging on the primary side of the coupled inductor and discharging in series on the primary side and the secondary side so that the voltage-gain can be greatly increased. Furthermore, the utility line can be connected to the negative end of the PV array to suppress leakage current, and the unfolding circuit can be simplified to reduce the conduction losses. High-frequency switching is only performed in one metal-oxide-semiconductor field-effect transistor (MOSFET) in each mode, which can effectively improve conversion efficiency. A prototype was implemented to obtain experimental results and to prove the validity of the proposed circuit structure.
A Comparative Numerical Analysis on the Effect of Welding Consumables on the Ballistic Resistance of SMAW Joints of Armor Steel
Authors: Saxena Ambuj , Dwivedi Shashi Prakash , Sharma Shubham , Srivastava Vishal Shankar , Singh Gursharan , Singh Jujhar , Chattopadhyaya Somnath , I. Pruncu Catalin
Published: April 2021

In the present investigation, a comparative study of ballistic impact behavior of Armox 500T (base metal) and its weldments prepared by low hydrogen ferrite (weldment-1) and austenitic stainless steel (weldment-2) consumables against 7.62 AP bullet has been performed with the help of finite element analysis code Abaqus 2017. Further, the result is validated with the experimental results. The experiment has been performed on the base metal, weldment-1, and weldment-2 against 7.62 AP bullet. Further, a two-dimensional explicit model has been developed for given purpose to simulate the bullet penetration at such high strain rate (103 s−1). Both bullet and plate are considered as deformable. Experimental results revealed that the depth of penetration in the base metal, weldment-1, and weldment-2 is 10.93, 13.65, and 15.20 mm respectively. Further computational results revealed that the depth of penetration of base metal, weldment-1, and weldment-2 is 10.11, 12.87, and 14.60 mm, respectively. Furthermore, weldment-1 shows more resistance against 7.62 AP bullet than weldment-2 in experimentation as well as FEA results. The percentage difference between experimental and FEA results are less than 10% which shows the prediction capability of FEA models. A feasibility analysis has been presented for using the welding consumables to weld the Armox 500T plate. Finally, in terms of ballistic resistance, the low hydrogen ferrite consumables are more appropriate than austenitic stainless-steel electrodes.
Exploring the Traveler’s Intentions to Use Public Transport during the COVID-19 Pandemic While Complying with Precautionary Measures
Authors: Abdullah Muhammad , Ali Nazam , Dias Charitha , Campisi Tiziana , Javid Muhammad Ashraf
Published: April 2021

Public transport use has drastically declined during the COVID-19 pandemic because the virus spreads through close contact with infected people and contaminated surfaces, especially in closed-environments. Evidence suggests that following the necessary safety guidelines can limit the spread of the virus, however, non-compliance to precautionary measures has been reported widely. Ignoring the precautionary measures may lead to quick transmission of the virus since public transport vehicles generally resemble closed-environments. This study explores people’s intentions to use public transport during the COVID-19 pandemic while adhering to precautionary measures. For this purpose, a total of 1516 useable responses were collected through a questionnaire survey conducted in Lahore, Pakistan. Regression models were developed to model the intentions to use public transport during the pandemic, to adhere to the precautionary measures while using public transport during the pandemic, and to use public transport while suffering from COVID-19 disease. The results of this study will help in understanding the intentions of the public transport users during the COVID-19 pandemic. It will also provide insights for policymakers and public transport operators about further necessary actions to promote safe public transport use during the current and any possible future pandemics. As public transport use declined during the pandemic, policy implications for alternative mobility options such as demand-responsive-transport (DRT) are also presented. Considering the study results, a policy interventions framework is proposed to promote the safe use of various public transport modes, particularly in developing regions.
Development of the Artificial Intelligence and Optical Sensing Methods for Oil Pollution Monitoring of the Sea by Drones
Authors: Bukin Oleg , Proschenko Dmitry , Korovetskiy Denis , Chekhlenok Alexey , Yurchik Viktoria , Bukin Ilya
Published: April 2021

The oil pollution of seas is increasing, especially in local areas, such as ports, roadsteads of the vessels, and bunkering zones. Today, methods of monitoring seawater are costly and applicable only in the case of big ecology disasters. The development of an operative and reasonable project for monitoring the sea surface for oil slick detection is described in this article using drones equipped with optical sensing and artificial intelligence. The monitoring system is implemented in the form of separate hard and soft frameworks (HSFWs) that combine monitoring methods, hardware, and software. Three frameworks are combined to fulfill the entire monitoring mission. HSFW1 performs the function of autonomous monitoring of thin oil slicks on the sea surface, using computer vision with AI elements for detection, segmentation, and classification of thin slicks. HSFW2 is based on the use of laser-induced fluorescence (LIF) to identify types of oil products that form a slick or that are in a dissolved state, as well as measure their concentration in solution. HSFW3 is designed for autonomous navigation and drone movement control. This article describes AI elements and hardware complexes of the three separate frameworks designed to solve the problems with monitoring slicks of oil products on the sea surface and oil products dissolved in seawater. The results of testing the HSFWs for the detection of pollution caused by marine fuel slicks are described.
Optimal Multi-Operation Energy Management in Smart Microgrids in the Presence of RESs Based on Multi-Objective Improved DE Algorithm: Cost-Emission Based Optimization
Authors: Ghiasi Mohammad , Niknam Taher , Dehghani Moslem , Siano Pierluigi , Haes Alhelou Hassan , Al-Hinai Amer
Published: April 2021

Today, in various leading power utilities in developing countries, achieving optimal operational energy management and planning, taking into account the costs reduction of generation, transmission and distribution of electricity, and also reducing the emission of an environmental pollutant becomes more and more important. Optimal use of renewable energy sources (RESs) is an effective way to achieve these goals. In this regard, in this research article, an improved multi-objective differential evolutionary (IMODE) optimization algorithm is suggested and performed to dispatch electricity generations in a smart microgrid (MG) system, taking into account economy and emission as competitive issues. In this paper, a nonlinear equation of multi-objective optimization issue with various equality and inequality limitations is formulated in order to lower the total operational costs of the MG considering environmental pollution effects simultaneously. In order to address the issue of optimal operation of the MG in single-objective and multi-objective forms, an intelligent method according to the improved differential evolutionary (IDE) optimization is utilized and performed and the proposed algorithm is implemented on different problems. First, it is assumed that there is no limit to the exchange of power overhead, and secondly, the limitation of power exchange with the upstream grid is considered. In multi-objective mode, these two modes are also considered. In order to show the impact of renewable energy on the cost, in the third part of the simulations, the operation is solved with maximum participation of renewable energy sources. In the final section, the sensitivity analysis on the number of populations in this problem is performed. The obtained results of the simulation are compared to differential evolutionary (DE) and particle swarm optimization (PSO) techniques. The effectiveness of the suggested multi-operational energy management method is confirmed by applying a study case system.
Semi-Active Control for a Helicopter with Multiple Landing Gears Equipped with Magnetorheological Dampers
Authors: Luong Quoc Viet , Jang Dae-Sung , Hwang Jai-Hyuk
Published: April 2021

Due to their extensive use in various applications, helicopters need to be able to land in a variety of conditions. Typically, a helicopter landing gear system with skids or passive wheel-dampers is designed based on only one critical touchdown condition. Thus, this helicopter landing gear system may not perform well in different landing conditions. A landing gear system with magnetorheological (MR) dampers would be a promising candidate to solve this problem. However, a semi-active controller must be designed to determine the electrical current applied to the MR damper to directly manage the damping force. This paper presents a new skyhook controller, called the skyhook extended controller, for a helicopter with multiple landing gears equipped with MR dampers to reduce the helicopter’s acceleration at the center of gravity in off-normal landing attitude conditions. A 9-DOF simulation model of a helicopter with multiple MR landing gears was built using RECURDYN. To verify the effectiveness of the proposed controller, co-simulations were executed with RECURDYN and MATLAB in different initial pitch and roll angles at touchdown. The main simulation results show that the proposed controller can greatly decrease the peak and rms acceleration of the helicopter’s center of gravity compared to a traditional skyhook controller and passive damper.
Filtered BERT: Similarity Filter-Based Augmentation with Bidirectional Transfer Learning for Protected Health Information Prediction in Clinical Documents
Authors: Kang Min , Lee Kye Hwa , Lee Youngho
Published: April 2021

For the secondary use of clinical documents, it is necessary to de-identify protected health information (PHI) in documents. However, the difficulty lies in the fact that there are few publicly annotated PHI documents. To solve this problem, in this study, we propose a filtered bidirectional encoder representation from transformers (BERT)-based method that predicts a masked word and validates the word again through a similarity filter to construct augmented sentences. The proposed method effectively performs data augmentation. The results show that the augmentation method based on filtered BERT improved the performance of the model. This suggests that our method can effectively improve the performance of the model in the limited data environment.
Dynamic Identification of Tensile Force in Tie-Rods by Interferometric Radar Measurements
Authors: Camassa Domenico , Castellano Anna , Fraddosio Aguinaldo , Miglionico Giuseppe , Piccioni Mario Daniele
Published: April 2021

An experimental investigation on the accuracy of dynamically determined tensile force in tie-rods by applying the interferometric radar technique was performed. Tie-rods were used in historical masonry constructions for absorbing thrusts of arches and vaults, and the radar interferometry may represent a fast and easy non-destructive approach for the tensile force identification in the occasion of structural assessments. Laboratory dynamic tests on a cable under a known tensile force show that, provided that a suitable dynamic identification model is used, tensile force evaluations made stating from interferometric radar measurements were characterized by a very good accuracy (mean error in the tensile force estimation less than 2%), comparable with evaluations made starting from accelerometric measurements. In particular, the dynamic identification model considered is a modified version of a model proposed in the literature. The influence on the accuracy in the determination of the tensile force of some features of the experimental setup, like, e.g., the employ of corner reflectors, is discussed.
Wind Energy Assessment during High-Impact Winter Storms in Southwestern Europe
Authors: Gonçalves Ana , Liberato Margarida L. R. , Nieto Raquel
Published: April 2021

The electricity produced through renewable resources is dependent on the variability of weather conditions and, thus, on the availability of the resource, as is the case with wind energy. This study aims to assess the wind resource available and the wind energy potential (WEP) during the December months for the three years 2017, 2018, and 2019, in southwestern Europe, when several high-impact storms affected the region. Additionally, a comparison of Prandtl’s logarithmic law and Power-law equations for extrapolation of the vertical wind profile is performed for onshore conditions, to evaluate the differences in terms of energy production, with the use of different equations. To assess the effect of the strong winds associated with the storms, 10 m wind components are used, with a 6-hourly temporal resolution, for the December months over the southwestern Europe region (30° N–65° N; 40° W–25° E). Results are compared to the climatology (1981–2010) and show an increase of wind intensity of 1.86 m·s−1 in southwestern Europe during December 2019, and a decrease up to 2.72 m·s−1 in December 2018. WEP is calculated for the selected wind turbine, 4 MW E-126 EP3—ENERCON, as well as the values following the wind resource record, that is, (i) higher values in December 2019 in the offshore and onshore regions, reaching 35 MWh and 20 MWh per day, respectively, and (ii) lower values in December 2018, with 35 MWh and 15 MWh per day for offshore and onshore. Differences in WEP when using the two equations for extrapolation of wind vertical profile reached 60% (40%) in offshore (onshore) regions, except for the Alps, where differences of up to 80% were reached. An additional analysis was made to understand the influence of the coefficients of soil roughness and friction used in each equation (Prandtl’s logarithmic law and Power-law), for the different conditions of onshore and offshore. Finally, it is notable that the highest values of wind energy production occurred on the stormy days affecting southwestern Europe. Therefore, we conclude that these high-impact storms had a positive effect on the wind energy production in this region.
Seasonal Variations of Carbonyls and Their Contributions to the Ozone Formation in Urban Atmosphere of Taiyuan, China
Authors: Liu Zeqian , Cui Yang , He Qiusheng , Guo Lili , Gao Xueying , Feng Yanli , Wang Yuhang , Wang Xinming
Published: April 2021

Ambient carbonyls are critical precursors of ozone (O3) and secondary organic aerosols (SOA). To better understand the pollution characteristics of carbonyls in Taiyuan, field samplings were conducted, and 13 carbonyls were detected in an urban site of Taiyuan for the four seasons. The total concentration of carbonyls in the atmosphere was 19.67 ± 8.56 μg/m3. Formaldehyde (7.70 ± 4.78 μg/m3), acetaldehyde (2.95 ± 1.20 μg/m3) and acetone (5.57 ± 2.41 μg/m3) were the dominant carbonyl compounds, accounting for more than 85% of the total carbonyls. The highest values for formaldehyde and acetone occurred in summer and autumn, respectively, and the lowest occurred in winter. The variations for acetaldehyde were not distinct in the four seasons. Formaldehyde and acetone levels increased obviously in the daytime and decreased at night, while acetaldehyde did not show significant diurnal variations. Higher temperature and stronger sunlight intensity could facilitate the photochemical reaction of volatile organic compounds (VOCs) and enhance the O3 levels in summer. Formaldehyde and acetaldehyde contributed 70–95% of carbonyls’ ozone formation potential (OFP) caused by carbonyls with the highest totals of 268.62 μg/m3 and 38.14 μg/m3, respectively. The highest concentrations of carbonyls from south and southwest winds in summer suggest that the coke industries in the southern Taiyuan Basin should be, firstly, controlled for the alleviation of ozone pollution.
Effects of Densification on Urban Microclimate—A Case Study for the City of Vienna
Authors: Loibl Wolfgang , Vuckovic Milena , Etminan Ghazal , Ratheiser Matthias , Tschannett Simon , Österreicher Doris
Published: April 2021

Climate adaptation, mitigation, and protecting strategies are becoming even more important as climate change is intensifying. The impacts of climate change are especially tangible in dense urban areas due to the inherent characteristics of urban structure and materiality. To assess impacts of densification on urban climate and potential adaptation strategies a densely populated Viennese district was modeled as a typical sample area for the city of Vienna. The case study analyzed the large-scale densification potential and its potential effects on microclimate, air flow, comfort, and energy demand by developing 3D models of the area showing the base case and densification scenarios. Three methods were deployed to assess the impact of urban densification: Micro-climate analysis (1) explored urban heat island phenomena, wind pattern analysis (2) investigated ventilation and wind comfort at street level, and energy and indoor climate comfort analysis (3) compared construction types and greening scenarios and analyzed their impact on the energy demand and indoor temperatures. Densification has negative impacts on urban microclimates because of reducing wind speeds and thus weakening ventilation of street canyons, as well as accelerating heat island effects and associated impact on the buildings. However, densification also has daytime cooling effects because of larger shaded areas. On buildings, densification may have negative effects especially in the new upper, sun-exposed floors. Construction material has less impact than glazing area and rooftop greening. Regarding adaptation to climate change, the impacts of street greening, green facades, and green roofs were simulated: The 24-h average mean radiant temperature (MRT) at street level can be reduced by up to 15 K during daytime. At night there is only a slight reduction by a few tenths of 1 K MRT. Green facades have a similar effect on MRT reduction, while green roofs show only a slight reduction by a few tenths of 1 K MRT on street level. The results show that if appropriate measures were applied, negative effects of densification could be reduced, and positive effects could be achieved.
Immediate and Delayed Meteorological Effects on COVID-19 Time-Varying Infectiousness in Tropical Cities
Authors: Seposo Xerxes , Ng Chris Fook Sheng , Madaniyazi Lina
Published: April 2021

The novel coronavirus, which was first reported in Wuhan, China in December 2019, has been spreading globally at an unprecedented rate, leading to the virus being declared a global pandemic by the WHO on 12 March 2020. The clinical disease, COVID-19, associated with the pandemic is caused by the pathogen severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Aside from the inherent transmission dynamics, environmental factors were found to be associated with COVID-19. However, most of the evidence documenting the association was from temperate locations. In this study, we examined the association between meteorological factors and the time-varying infectiousness of COVID-19 in the Philippines. We obtained the daily time series from 3 April 2020 to 2 September 2020 of COVID-19 confirmed cases from three major cities in the Philippines, namely Manila, Quezon, and Cebu. Same period city-specific daily average temperature (degrees Celsius; °C), dew point (degrees Celsius; °C), relative humidity (percent; %), air pressure (kilopascal; kPa), windspeed (meters per second; m/s) and visibility (kilometer; km) data were obtained from the National Oceanic and Atmospheric Administration—National Climatic Data Center. City-specific COVID-19-related detection and intervention measures such as reverse transcriptase polymerase chain reaction (RT-PCR) testing and community quarantine measures were extracted from online public resources. We estimated the time-varying reproduction number (Rt) using the serial interval information sourced from the literature. The estimated Rt was used as an outcome variable for model fitting via a generalized additive model, while adjusting for relevant covariates. Results indicated that a same-day and the prior week’s air pressure was positively associated with an increase in Rt by 2.59 (95% CI: 1.25 to 3.94) and 2.26 (95% CI: 1.02 to 3.50), respectively. Same-day RT-PCR was associated with an increase in Rt, while the imposition of community quarantine measures resulted in a decrease in Rt. Our findings suggest that air pressure plays a role in the infectiousness of COVID-19. The determination of the association of air pressure on infectiousness, aside from the testing frequency and community quarantine measures, may aide the current health systems in controlling the COVID-19 infectiousness by integrating such information into an early warning platform.
Measurements of NOx and Development of Land Use Regression Models in an East-African City
Authors: Abera Asmamaw , Malmqvist Ebba , Mandakh Yumjirmaa , Flanagan Erin , Jerrett Michael , Gebrie Geremew Sahilu , Bayih Abebe Genetu , Aseffa Abraham , Isaxon Christina , Mattisson Kristoffer
Published: April 2021

Air pollution causes premature mortality and morbidity globally, but these adverse health effects occur over proportionately in low- and middle-income countries. Lack of both air pollution data and knowledge of its spatial distribution in African countries have been suggested to lead to an underestimation of health effects from air pollution. This study aims to measure nitrogen oxides (NOx), as well as nitrogen dioxide (NO2), to develop Land Use Regression (LUR) models in the city of Adama, Ethiopia. NOx and NO2 was measured at over 40 sites during six days in both the wet and dry seasons. Throughout the city, measured mean levels of NOx and NO2 were 29.0 µg/m3 and 13.1 µg/m3, respectively. The developed LUR models explained 68% of the NOx variances and 75% of the NO2. Both models included similar geographical predictor variables (related to roads, industries, and transportation administration areas) as those included in prior LUR models. The models were validated by using leave-one-out cross-validation and tested for spatial autocorrelation and multicollinearity. The performance of the models was good, and they are feasible to use to predict variance in annual average NOx and NO2 concentrations. The models developed will be used in future epidemiological and health impact assessment studies. Such studies may potentially support mitigation action and improve public health.
Bone Morphogenetic Proteins and Diabetic Retinopathy
Authors: Elmasry Khaled , Habib Samar , Moustafa Mohamed , Al-Shabrawey Mohamed
Published: April 2021

Bone morphogenetic proteins (BMPs) play an important role in bone formation and repair. Recent studies underscored their essential role in the normal development of several organs and vascular homeostasis in health and diseases. Elevated levels of BMPs have been linked to the development of cardiovascular complications of diabetes mellitus. However, their particular role in the pathogenesis of microvascular dysfunction associated with diabetic retinopathy (DR) is still under-investigated. Accumulated evidence from our and others’ studies suggests the involvement of BMP signaling in retinal inflammation, hyperpermeability and pathological neovascularization in DR and age-related macular degeneration (AMD). Therefore, targeting BMP signaling in diabetes is proposed as a potential therapeutic strategy to halt the development of microvascular dysfunction in retinal diseases, particularly in DR. The goal of this review article is to discuss the biological functions of BMPs, their underlying mechanisms and their potential role in the pathogenesis of DR in particular.
The Role of Androgens and Androgen Receptor in Human Bladder Cancer
Authors: Martínez-Rojo Elizabeth , Berumen Laura , García-Alcocer Guadalupe , Escobar-Cabrera Jesica
Published: April 2021

Bladder cancer (urothelial carcinoma) is one of the most frequently diagnosed neoplasms, with an estimated half a million new cases and 200,000 deaths per year worldwide. This pathology mainly affects men. Men have a higher risk (4:1) of developing bladder cancer than women. Cigarette smoking and exposure to chemicals such as aromatic amines, and aniline dyes have been established as risk factors for bladder cancer and may contribute to the sex disparity. Male internal genitalia, including the urothelium and prostate, are derived from urothelial sinus endoderm; both tissues express the androgen receptor (AR). Several investigations have shown evidence that the AR plays an important role in the initiation and development of different types of cancer including bladder cancer. In this article, we summarize the available data that help to explain the role of the AR in the development and progression of bladder cancer, as well as the therapies used for its treatment.
Structural Basis for the C-Terminal Domain of Mycobacterium tuberculosis Ribosome Maturation Factor RimM to Bind Ribosomal Protein S19
Authors: Zhang Haoran , Zhou Qiuxiang , Guo Chenyun , Feng Liubin , Wang Huilin , Liao Xinli , Lin Donghai
Published: April 2021

Multidrug-resistant tuberculosis (TB) is a serious threat to public health, calling for the development of new anti-TB drugs. Chaperon protein RimM, involved in the assembly of ribosomal protein S19 into 30S ribosomal subunit during ribosome maturation, is a potential drug target for TB treatment. The C-terminal domain (CTD) of RimM is primarily responsible for binding S19. However, both the CTD structure of RimM from Mycobacterium tuberculosis (MtbRimMCTD) and the molecular mechanisms underlying MtbRimMCTD binding S19 remain elusive. Here, we report the solution structure, dynamics features of MtbRimMCTD, and its interaction with S19. MtbRimMCTD has a rigid hydrophobic core comprised of a relatively conservative six-strand β-barrel, tailed with a short α-helix and interspersed with flexible loops. Using several biophysical techniques including surface plasmon resonance (SPR) affinity assays, nuclear magnetic resonance (NMR) assays, and molecular docking, we established a structural model of the MtbRimMCTD–S19 complex and indicated that the β4-β5 loop and two nonconserved key residues (D105 and H129) significantly contributed to the unique pattern of MtbRimMCTD binding S19, which might be implicated in a form of orthogonality for species-dependent RimM–S19 interaction. Our study provides the structural basis for MtbRimMCTD binding S19 and is beneficial to the further exploration of MtbRimM as a potential target for the development of new anti-TB drugs.
Ecklonia cava Extract and Its Derivative Dieckol Promote Vasodilation by Modulating Calcium Signaling and PI3K/AKT/eNOS Pathway in In Vitro and In Vivo Models
Authors: Lu Yu-An , Je Jun-Geon , Hwang Jin , Jeon You-Jin , Ryu BoMi
Published: April 2021

Nitric oxide (NO), an endothelial-derived relaxing factor synthesized by endothelial nitric oxide synthase (eNOS) in endothelial cells, enhances vasodilation by modulating vascular tone. The calcium concentration critically influences eNOS activation in endothelial cells. Thus, modulation of calcium-dependent signaling pathways may be a potential therapeutic strategy to enhance vasodilation. Marine algae reportedly possess protective effects against cardiovascular disorders, including hypertension and vascular dysfunction; however, the underlying molecular signaling pathways remain elusive. In the present study, we extracted and isolated dieckol from Ecklonia cava and investigated calcium transit-enhanced vasodilation. Calcium modulation via the well-known M3 muscarinic acetylcholine receptor (AchM3R), which is linked to NO formation, was investigated and the vasodilatory effect of dieckol was verified. Our results indicated that dieckol effectively promoted NO generation via the PI3K/Akt/eNOS axis and calcium transients influenced by AchM3R. We also treated Tg(flk: EGFP) transgenic zebrafish with dieckol to assess its vasodilatory effect. Dieckol promoted vasodilation by enlarging the dorsal aorta diameter, thus regulating blood flow velocity. In conclusion, our findings suggest that dieckol modulates calcium transit through AchM3R, increases endothelial-dependent NO production, and efficiently enhances vasodilation. Thus, E. cava and its derivative, dieckol, can be considered as potential natural vasodilators.
Microsurgical Anatomy of the Anterior Circulation of the Brain Adjusted to the Neurosurgeon’s Daily Practice
Authors: Poblete Tomas , Casanova Daniel , Soto Miguel , Campero Alvaro , Mura Jorge
Published: April 2021

The study of cerebrovascular anatomy can be difficult and may take time due to its intrinsic complexity. However, it can also be difficult for the following reasons: the excessive description of neuroanatomy making articles hard to read, the unclear clinical application of what is written, the use of simplified or intricate schematic drawings that are not always appropriate for effective teaching, the poor quality of neuroanatomy dissections and the use of unusual views of figures that are not strictly related to the most frequent neuroimages to be interpreted in daily practice. Because of this, we designed an article that incorporates original and accurate anatomical dissections in an attempt to improve its comprehensibility. Five formalin-fixed adult cadaveric heads, whose vessels were injected with a colored silicone mixture (red for arteries and blue for veins), were dissected and examined under a microscope with magnifications from 3× to 40×. Special emphasis has been placed on correlating topographic anatomy with routine neuroimaging studies from computed tomographic angiography (CTA) and digital subtraction angiography (DSA). The essential surgical anatomy in a neurosurgeon’s daily practice is also described. The cadaveric dissections included in this study contribute to the understanding of the cerebrovascular anatomy necessary for the neurosurgeon’s daily practice.
The Potential of FGF-2 in Craniofacial Bone Tissue Engineering: A Review
Authors: Novais Anita , Chatzopoulou Eirini , Chaussain Catherine , Gorin Caroline
Published: April 2021

Bone is a hard-vascularized tissue, which renews itself continuously to adapt to the mechanical and metabolic demands of the body. The craniofacial area is prone to trauma and pathologies that often result in large bone damage, these leading to both aesthetic and functional complications for patients. The “gold standard” for treating these large defects is autologous bone grafting, which has some drawbacks including the requirement for a second surgical site with quantity of bone limitations, pain and other surgical complications. Indeed, tissue engineering combining a biomaterial with the appropriate cells and molecules of interest would allow a new therapeutic approach to treat large bone defects while avoiding complications associated with a second surgical site. This review first outlines the current knowledge of bone remodeling and the different signaling pathways involved seeking to improve our understanding of the roles of each to be able to stimulate or inhibit them. Secondly, it highlights the interesting characteristics of one growth factor in particular, FGF-2, and its role in bone homeostasis, before then analyzing its potential usefulness in craniofacial bone tissue engineering because of its proliferative, pro-angiogenic and pro-osteogenic effects depending on its spatial-temporal use, dose and mode of administration.
Bacillus subtilis PcrA Helicase Removes Trafficking Barriers
Authors: Moreno-del Álamo María , Carrasco Begoña , Torres Rubén , Alonso Juan Carlos
Published: April 2021

Bacillus subtilis PcrA interacts with the RNA polymerase and might contribute to mitigate replication–transcription conflicts (RTCs). We show that PcrA depletion lethality is partially suppressed by rnhB inactivation, but cell viability is significantly reduced by rnhC or dinG inactivation. Following PcrA depletion, cells lacking RnhC or DinG are extremely sensitive to DNA damage. Chromosome segregation is not further impaired by rnhB or dinG inactivation but is blocked by rnhC or recA inactivation upon PcrA depletion. Despite our efforts, we could not construct a ΔrnhC ΔrecA strain. These observations support the idea that PcrA dismantles RTCs. Purified PcrA, which binds single-stranded (ss) DNA over RNA, is a ssDNA-dependent ATPase and preferentially unwinds DNA in a 3′→5′direction. PcrA unwinds a 3′-tailed RNA of an RNA-DNA hybrid significantly faster than that of a DNA substrate. Our results suggest that a replicative stress, caused by mis-incorporated rNMPs, indirectly increases cell viability upon PcrA depletion. We propose that PcrA, in concert with RnhC or DinG, contributes to removing spontaneous or enzyme-driven R-loops, to counteract deleterious trafficking conflicts and preserve to genomic integrity.
Microneedle Arrays for Sampling and Sensing Skin Interstitial Fluid
Authors: Kashaninejad Navid , Munaz Ahmed , Moghadas Hajar , Yadav Sharda , Umer Muhammad , Nguyen Nam-Trung
Published: April 2021

Dermal interstitial fluid (ISF) is a novel source of biomarkers that can be considered as an alternative to blood sampling for disease diagnosis and treatment. Nevertheless, in vivo extraction and analysis of ISF are challenging. On the other hand, microneedle (MN) technology can address most of the challenges associated with dermal ISF extraction and is well suited for long-term, continuous ISF monitoring as well as in situ detection. In this review, we first briefly summarise the different dermal ISF collection methods and compare them with MN methods. Next, we elaborate on the design considerations and biocompatibility of MNs. Subsequently, the fabrication technologies of various MNs used for dermal ISF extraction, including solid MNs, hollow MNs, porous MNs, and hydrogel MNs, are thoroughly explained. In addition, different sensing mechanisms of ISF detection are discussed in detail. Subsequently, we identify the challenges and propose the possible solutions associated with ISF extraction. A detailed investigation is provided for the transport and sampling mechanism of ISF in vivo. Also, the current in vitro skin model integrated with the MN arrays is discussed. Finally, future directions to develop a point-of-care (POC) device to sample ISF are proposed.
Carboxylated Graphene Nanoribbons for Highly-Selective Ammonia Gas Sensors: Ab Initio Study
Authors: Barkov Pavel V. , Glukhova Olga E.
Published: April 2021

The character and degree of influence of carboxylic acid groups (COOH) on the sensory properties (particularly on the chemoresistive response) of a gas sensor based on zigzag and armchair graphene nanoribbons are shown. Using density functional theory (DFT) calculations, it is found that it is more promising to use a carboxylated zigzag nanoribbon as a sensor element. The chemoresistive response of these nanoribbons is higher than uncarboxylated and carboxylated nanoribbons. It is also revealed that the wet nanoribbon reacts more noticeably to the adsorption of ammonia. In this case, carboxyl groups primarily attract water molecules, which are energetically favorable to land precisely on these regions and then on the nanoribbon’s basal surface. Moreover, the COOH groups with water are adsorption centers for ammonia molecules. That is, the carboxylated zigzag nanoribbon can be the most promising.
Psychosocial Factors and Obesity in Adolescence: A Case-Control Study
Authors: Andrie Elisabeth K. , Melissourgou Marina , Gryparis Alexandros , Vlachopapadopoulou Elpis , Michalacos Stephanos , Renouf Anais , Sergentanis Theodoros N. , Bacopoulou Flora , Karavanaki Kyriaki , Tsolia Maria , Tsitsika Artemis
Published: April 2021

Introduction: The continuously increasing prevalence of childhood obesity is reaching epidemic proportions. Greece is among the countries with the highest childhood obesity prevalence rates. The present study aims to identify psychosocial factors associated with excess body weight of adolescents. Methods: This case-control study was conducted in Athens, Greece, and included 414 adolescents aged 11–18 years. Anthropometric measurements were recorded, and an anonymous self-completed questionnaire captured the psychosocial background, family environment, peer relations, and school environment. Results: Of the total sample of adolescents, 54.6% had normal body weight and 45.4% were overweight or obese. A multivariate logistic regression analysis showed that the factors related to the presence of overweight/obesity were adolescents’ age (OR = 0.416, p < 0.001), area of residence, presence of anxiety (OR = 4.661, p = 0.001), presence of melancholia (OR = 2.723, p = 0.016), participation in sports (OR = 0.088, p <0.001), smoking (OR = 0.185, p = 0.005), and mother’s occupation (OR = 0.065, p < 0.001). Conclusion: Psychological problems, maternal occupation, the absence of physical activity, and poor school performance were associated with adolescent overweight/obesity. It is important that screening for the presence of psychosocial issues is included in childhood obesity policies and treatment.