bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanism and Prevention of Rockburst in Steeply Inclined and Extremely Thick Coal Seams for Fully Mechanized Top-Coal Caving Mining and Under Gob Filling Conditions
Authors: He Shengquan , Song Dazhao , Li Zhenlei , He Xueqiu , Chen Jianqiang , Zhong Taoping , Lou Quan
Published: March 2020

The steeply inclined and extremely thick coal seams (SIETCS) under the condition of gob filling frequently suffer from the occurrence of rockbursts. Figuring out the mechanisms of rockbursts under this condition for taking targeted measures to mitigate rockburst hazards in SIETCS is of great significance. Using the typical SIETCS with an average dip angle of 87° at Wudong Coal Mine (WCM) as a case study, a mechanical model and elastic deformation energy (EDE) function of a “steeply inclined suspended roof structure” was developed, and the influence factors were analyzed by theoretical analysis. Simultaneously, the rockburst risk assessment was carried out based on the theory of a rockburst start-up. The pressure relief measures are optimized by comparing the pressure relief effects of three kinds of destress blasting schemes. The results indicate that the damage characteristics of rockburst are mainly floor heave, the sidewall’s inward deformation and roof subsidence. The damage degree of headentry on the roof side is more severe than that of tailentry, and the resultant impacts showed the directionality from the roof side to the coal side. The steeply inclined and suspended roof breakage is one of the main causes for the occurrence of rockbursts. The EDE of the roof increases with an increasing dip angle of the coal seam from 0° to 72.6° and then decreases as the dip angle increases. Furthermore, that increase is accompanied by the decrease of the lateral pressure coefficient and the supporting force coefficient. The EDE stored in the roof is sufficient to cause roof breakage and induce rockburst after the complete roof exceeds a certain length. The mechanism of rockburst in SIETCS for fully mechanized top-coal caving mining under gob filling conditions was proposed, i.e., “high compressive stress concentration plus breakage of the suspended roof-induced stress” rockburst, and this is further verified by ground destruction, microseismic (MS) monitoring and numerical modeling. The results also indicate that alternate deep and shallow hole-blasting modes are more suitable for pressure relief in SIETCS.
Heavy Oil Laminar Flow in Corrugated Ducts: A Numerical Study Using the Galerkin-Based Integral Method
Authors: Alves dos Santos Júnior Valdecir , Rodrigues de Farias Neto Severino , Gilson Barbosa de Lima Antonio , Fernandes Gomes Igor , Buriti Galvão Israel , Maria Rufino Franco Célia , Evangelista Franco do Carmo João
Published: March 2020

Fluid flow in pipes plays an important role in different areas of academia and industry. Due to the importance of this kind of flow, several studies have involved circular cylindrical pipes. This paper aims to study fully developed internal laminar flow through a corrugated cylindrical duct, using the Galerkin-based integral method. As an application, we present a study using heavy oil with a relative density of 0.9648 (14.6 °API) and temperature-dependent viscosities ranging from 1715 to 13000 cP. Results for different fluid dynamics parameters, such as the Fanning friction factor, Reynolds number, shear stress, and pressure gradient, are presented and analyzed based on the corrugation number established for each section and aspect ratio of the pipe.
Stall Control by Plasma Actuators: Characterization along the Airfoil Span
Authors: Zoppini Giulia , Belan Marco , Zanotti Alex , Di Vinci Lorenzo , Campanardi Giuseppe
Published: March 2020

A dielectric barrier discharge actuator (DBD) is considered and studied as a stall recovery device. The DBD is installed on the nose of a NACA0015 airfoil with chord × span 300 × 930 mm. The geometry of the exposed electrode has periodic triangular tips purposely designed for the case under study. Wind tunnel tests have been carried out over a range of airspeeds up to 35 m/s with a Reynolds number of 700 k. The flow morphology has been characterized by means of the particle image velocimetry technique, obtaining velocity fields and pressure coefficients. By exploring different planes along the model span, the three-dimensional effect of the DBD has been reconstructed, identifying the flow region mainly sensitive to the plasma actuation. Finally, the actuator effectiveness has been quantified accounting for the power consumption data, leading to defining further design improvements in view of a better efficiency.
Comparative Study on the Effects of Three Membrane Modification Methods on the Performance of Microbial Fuel Cell
Authors: Fan Liping , Shi Junyi , Gao Tian
Published: March 2020

Proton exchange membrane is an important factor affecting the power generation capacity and water purification effect of microbial fuel cells. The performance of microbial fuel cells can be improved by modifying the proton exchange membrane by some suitable method. Microbial fuel cells with membranes modified by SiO2/PVDF (polyvinylidene difluoride), sulfonated PVDF and polymerized MMA (methyl methacrylate) electrolyte were tested and their power generation capacity and water purification effect were compared. The experimental results show that the three membrane modification methods can improve the power generation capacity and water purification effect of microbial fuel cells to some extent. Among them, the microbial fuel cell with the polymerized MMA modified membrane showed the best performance, in which the output voltage was 39.52 mV, and the electricity production current density was 18.82 mA/m2, which was 2224% higher than that of microbial fuel cell with the conventional Nafion membrane; and the COD (chemical oxygen demand) removal rate was 54.8%, which was 72.9% higher than that of microbial fuel cell with the conventional Nafion membrane. Modifying the membrane with the polymerized MMA is a very effective way to improve the performance of microbial fuel cells.
Instantaneous Rotational Speed Algorithm for Locating Malfunctions in Marine Diesel Engines
Authors: Kazienko Damian , Chybowski Leszek
Published: March 2020

This article suggested broadening the standard methods for diagnosing the technical condition of diesel engines to include an analysis of the instantaneous rotational speed of compression combustion engines with the use of a novel algorithm. The authors revised the subject concerning the use of the analysis of instantaneous changes in the rotational speed of an engine when assessing its technical condition and the location of the malfunction. An algorithm and its practical implementation in a prototype diagnostic system called SpeedMA were presented. This article reported the test results of the prototype in the context of indicating the engine cylinder in which ignition failed to occur. Tests were carried out for two marine engines: a low-speed trunk engine directly driving the fixed-pitch propeller and a medium-speed trunk engine driving the alternator. For each case, an analysis was carried out for different engine loads and at individual cylinders in which combustion failed to occur. The experimental results showed an unambiguous relation between the combustion process of the examined engines and changes in the instantaneous rotational speed. The results also confirmed the usefulness of the proposed method and showed the correct operation of the presented diagnostic algorithm. The proposed diagnostic system could be used during the operation of engines running in real ship engine rooms.
Barrier Analysis for the Deployment of Renewable-Based Mini-Grids in Myanmar Using the Analytic Hierarchy Process (AHP)
Authors: Numata Masako , Sugiyama Masahiro , Mogi Gento
Published: March 2020

Energy access remains a challenge for many countries, as recognized by sustainable development goal 7 of the United Nations Development Programme. Although the Myanmar government has set a target of 100% electrification by 2030, less than half of the households are currently connected to the national grid. To expedite electrification, decentralized approaches should be considered. Mini-grids are an effective alternative that can fill the gap between a solar home system and the national grid; however, many of the existing mini-grids in Myanmar are powered by diesel generators. Diesel fuel is significantly more expensive in rural areas than in urban areas due to high transportation costs. Although mini-grids powered by solar photovoltaics and batteries are cost-competitive with diesel generators, the deployment of renewable energy-based mini-grids is slow. In this study, we analyzed the barriers to mini-grid deployment and prioritized the barriers. We conducted a questionnaire survey with stakeholders using the analytic hierarchy process to identify the prioritization of each barrier factor. The K-means clustering method was used to determine tendencies and showed that there was no single, dominant solution. Our results confirm the difficulty of mini-grid deployment and suggest multi-pronged approaches that go beyond economic considerations.
Security of IoT Application Layer Protocols: Challenges and Findings
Authors: Nebbione Giuseppe , Calzarossa Maria Carla
Published: March 2020

IoT technologies are becoming pervasive in public and private sectors and represent presently an integral part of our daily life. The advantages offered by these technologies are frequently coupled with serious security issues that are often not properly overseen or even ignored. The IoT threat landscape is extremely wide and complex and involves a wide variety of hardware and software technologies. In this framework, the security of application layer protocols is of paramount importance since these protocols are at the basis of the communications among applications and services running on different IoT devices and on cloud/edge infrastructures. This paper offers a comprehensive survey of application layer protocol security by presenting the main challenges and findings. More specifically, the paper focuses on the most popular protocols devised in IoT environments for messaging/data sharing and for service discovery. The main threats of these protocols as well as the Common Vulnerabilities and Exposures (CVE) for their products and services are analyzed and discussed in detail. Good practices and measures that can be adopted to mitigate threats and attacks are also investigated. Our findings indicate that ensuring security at the application layer is very challenging. IoT devices are exposed to numerous security risks due to lack of appropriate security services in the protocols as well as to vulnerabilities or incorrect configuration of the products and services being deployed. Moreover, the constrained capabilities of these devices affect the types of security services that can be implemented.
A Comparative Study of the Role of Interpersonal Communication, Traditional Media and Social Media in Pro-Environmental Behavior: A China-Based Study
Authors: Han Ruixia , Xu Jian
Published: March 2020

Previous studies have confirmed that information exposure affects pro-environmental behavior. With the rise of social media, new questions emerge in terms of whether different types of information exposure affect pro-environmental behavior differently. Based on a survey of 550 people that was carried out in China, this study aims to compare the different roles of interpersonal communication, traditional media, and social media in affecting the relationships between people’s environmental risk perception, willingness to contribute to the environment, environmental knowledge, environmental concerns, and pro-environmental behavior. Our research discovered that: (1) traditional media has almost no effect on pro-environmental behavior; (2) interpersonal communication can affect pro-environmental behavior through significantly affecting environmental risk perception; (3) social media affects pro-environmental behavior mainly by strengthening the effects of interpersonal communication. The research reveals that while different types of information exposure affect pro-environmental behavior differently, interpersonal communication plays a central role. Concerning the mutual influence between social media and interpersonal communication, we propose that we could promote pro-environmental behavior by activating social media communication.
Small-Sided Games as a Methodological Resource for Team Sports Teaching: A Systematic Review
Authors: Fernández-Espínola Carlos , Abad Robles Manuel Tomás , Giménez Fuentes-Guerra Francisco Javier
Published: March 2020

New models for teaching sports have arisen in the last years, characterised by the use of more contextualised situations, modified games, tactical awareness, transference of technical–tactical learning and different teaching progression, among other aspects. In this regard, small-sided games must be highlighted, due to their ability to integrate physical fitness, technique and tactical behaviour stimuli in similar conditions to the real game. Therefore, the aim of this systematic review was to analyse and describe the methodological possibilities that SSGs can provide regarding the teaching of technical–tactical aspects in team sports at young ages. The guidelines of the PRISMA declaration were followed with the purpose of conducting a systematic search. The search was performed in the databases Pubmed, Web of Science, Scopus and SportDiscus. From the 451 identified in an early phase, plus the 20 found in the references of other studies, only 47 met the inclusion criteria and were selected. The results yielded scientific evidence that justifies the use of small-sided games as a methodological resource for sports teaching at young ages. Among the main reasons, it can be highlighted that a reduction in the number of players and in the size of the pitch area increases the total ball contact per player and, therefore, the number of technical actions. Moreover, the intentional modification of certain rules helps to develop some sport training fundamentals.
Equipment for Testing Measuring Devices at a Low-Level Radon Activity Concentration
Authors: Fialova Eliska , Otahal Petr P. S. , Vosahlik Josef , Mazanova Monika
Published: March 2020

The National Institute for Nuclear, Biological, and Chemical Protection, under the European project 16ENV10 MetroRADON (the European metrology program for innovation and research, EMPIR), has developed unique equipment for the testing of measuring devices at low-level radon activity concentrations. The equipment consists particularly of an airtight low-level radon chamber (LLRCH) with an inner volume of 324 liters; a Rn-222 type RF 5 flow-through source with a Ra-226 activity of 4.955 kBq developed by Czech Metrological Institute within the above-mentioned project; and a pressure vessel as a radon-free air source. The mass flow controller of the Bronkhorst EL-Flow type is a part of the apparatus and ensures the requested airflow through the radon source—partialized if necessary—through the chamber. The homogeneity of the atmosphere in the chamber is ensured by means of a continuously regulated fan (airflows in the range of 0.1–3.5 m·s−1 can be established). Another important chamber component is the measuring device of climatic conditions, since temperature, air pressure, and relative humidity must be determined. The construction of the equipment allows the time-stable radon activity concentration to be maintained at a precise level for several days. Radon concentration values can be arbitrarily and continuously set in the range from 100 Bq·m−3 to 300 Bq·m−3.
Examination of Transition Readiness, Medication Adherence, and Resilience in Pediatric Chronic Illness Populations: A Pilot Study
Authors: Verma Tanvi , Rohan Jennifer
Published: March 2020

The present study assessed the relationship between resilience, adherence, and transition readiness in adolescents/young adults with chronic illness. Participants included 50 patients (Mean age, Mage = 17.3 ± 2.1 years) diagnosed with an oncology disorder (n = 7; 12.1%), hematology disorder (n = 5; 8.6%), nephrology disorder (n = 31; 53.4%), or rheumatology disorder (n = 7; 12.1%). Patients were administered questionnaires assessing resilience (Conner–Davidson Resilience Scale 25-item questionnaire, CD-RISC-25), transition readiness (Self-Management and Transition to Adulthood with Rx=Treatment, STARx), and self-reported medication adherence (Medication Adherence Module, MAM). Medical chart reviews were conducted to determine objective medication adherence rates based on pharmacy refill history (medication adherence ratios). A multivariate correlation analysis was used to examine the relationship between resilience, transition readiness, and adherence. There was a moderate relationship (r = 0.34, p ≤ 0.05) between resilience (M = 74.67 ± 13.95) and transition readiness (M = 67.55 ± 8.20), such that more resilient patients reported increased readiness to transition to adult care. There also was a strong relationship (r = 0.80, p ≤ 0.01) between self-reported medication adherence (M = 86.27% ± 15.98) and pharmacy refill history (Mean Medication Adherence Ratio, MMAR = 0.75 ± 0.27), which indicated that self-reported adherence was consistent with prescription refill history across pediatric illness cohorts. Our findings underscore the importance of assessing resilience, transition readiness, and adherence years before transitioning pediatric patients to adult providers to ensure an easier transition to adult care.
The Repolarization Period during the Head-Up Tilt Test in Children with Vasovagal Syncope
Authors: Kolarczyk Ewelina , Markiewicz-Łoskot Grażyna , Szydłowski Lesław
Published: March 2020

Background: Electrocardiography (ECG) and the head-up tilt test (HUTT) are vital in clinical work-up in children with vasovagal syncope (VVS). Ventricular repolarization parameters (QT) measured during the HUTT can be indicative of electrical instability; however, these parameters are not frequently assessed. This study aimed to investigate if ventricular repolarization parameters measured during the HUTT could be indicative of future ventricular arrhythmias in children with syncope. Methods: The shape and amplitude of the T-wave and parameters of the repolarization period (QT, QTpeak, Tpeak-Tend) were evaluated in a resting ECG performed on the first day of hospitalization and in ECGs performed during three phases of the HUTT. Results: In the after-tilt phase of the HUTT, 19/30 children displayed a change in T-wave morphology. QTc was significantly longer in VVS I compared to that in VVS II patients, but not in the controls (p = 0.092). Conclusions: We need further follow-up studies to establish the clinical importance of abnormal dynamics of the repolarization period in children with VVS and negative HUTT. Therefore, children with abnormal T-wave refraction and prolonged duration of the TpTe should remain under the care of a cardiological outpatient.
Randomized Trial Examining Effects of Animal Assisted Intervention and Stress Related Symptoms on College Students’ Learning and Study Skills
Authors: Pendry Patricia , Carr Alexa M. , Gee Nancy R. , Vandagriff Jaymie L.
Published: March 2020

Animal Visitation Programs (AVPs) targeting college students’ stress and academic success have increased, despite limited research on academic outcomes. This randomized controlled trial (N = 349) examined the effects of incorporating levels of Human–animal Interaction (HAI) (0%, 50% or 100%) with therapy dogs in a four-week academic stress management program. Conditions included (1) Academic Stress Management (ASM) content only (0% HAI), (2) Human–animal Interaction only (100% HAI) and (3) equal combinations of ASM content and HAI (50% HAI). Intention-to-treat (ITT) analyses examined the effects of students’ risk status (N = 146; depression, anxiety, perceived stress, worry) and treatment condition on students’ learning and study strategies at posttest and follow-up. The results showed interactions between condition and risk status demonstrating higher posttest levels of WILL (i.e., anxiety, attitude, motivation) (Β = 0.582, p = 0.005) and SELFREGULATION (i.e., concentration, self-testing, study aids, time management) (Β = 0.501, p = 0.031) for at-risk students receiving equal combinations of HAI and content presentations. Moderation effects remained at follow-up (Β = 0.626, p = 0.005; Β = 0.630, p = 0.007). At-risk students receiving only HAI (100%) also showed higher levels of WILL at posttest (Β = 0.481, p = 0.021) and follow up (Β = 0.490, p = 0.038). University administrators should consider providing at-risk students with targeted programs with varying levels of HAI and ASM content, depending on the targeted academic outcome.
Biomonitoring of Mercury in Hair among a Group of Eritreans (Africa)
Authors: Astolfi Maria Luisa , Protano Carmela , Marconi Elisabetta , Massimi Lorenzo , Piamonti Daniel , Brunori Marco , Vitali Matteo , Canepari Silvia
Published: March 2020

Small-scale or artisanal mining, using gold-mercury amalgamation to extract gold from ore, is a significant source of exposure for the workers and nearby populations. Few studies on hair mercury (Hg) have been conducted in Africa despite the fact that Africa has several gold deposits. No studies have been conducted in Eritrea that is one of the emerging gold producing countries in Africa. The aim of the study was to assess the Hg concentration in hair samples (n = 120) of a population living in Asmara, capital of Eritrea, and to evaluate the influence of some factors on the Hg levels in hair. Information on age, height, weight, occupation, smoking and fish consumption of participants were collected via questionnaire. Hair Hg concentration was significantly higher among women compared to men (p < 0.001) and among women preparing spicy products in Medeber market compared to those who did other jobs (p = 0.010). These results highlight the need for routine biomonitoring surveys and for health promotion campaigns devoted to local decision makers and workers.
The Oral Health Status of Chinese Elderly People with and without Dementia: A Cross-Sectional Study
Authors: Gao Sherry Shiqian , Chen Kitty Jieyi , Duangthip Duangporn , Lo Edward Chin Man , Chu Chun Hung
Published: March 2020

Objective: The objective of this study was to compare the caries, periodontal status, and toothbrushing practices of Chinese elderly people with and without dementia. Methods: This cross-sectional study recruited Chinese people aged 65 years or over attending daycare centers in Hong Kong. The participants’ dementia status was identified from their medical record. Their demographic information and toothbrushing practices were obtained through a questionnaire survey. Caries experience, periodontal status, and oral hygiene were measured using the Decayed, Missing, and Filled Teeth (DMFT) Index, Community Periodontal Index, and Visible Plaque Index (VPI), respectively. The case matching process, using the propensity score, was conducted to match the participants in dementia and nondementia groups. The chi-square test and t-test were conducted for analysis. Results: A total of 341 elderly people participated in this study. After case matching by gender and age, 129 participants with dementia were matched with 99 participants without dementia. The mean age and mean DMFT of the dementia group versus the nondementia group were 80.9 ± 7.5 vs. 79.4 ± 6.7 (p = 0.428) and 22.5 ± 7.9 vs. 19.2 ± 9.3 (p = 0.041), respectively. There was no significant difference of periodontal status observed. The VPI of dementia and nondementia groups were 77% and 63%, respectively (p = 0.027). Though they had no difference in frequency of toothbrushing, more dementia participants encountered difficulties in toothbrushing than those without dementia (57% vs. 8%, p < 0.001). Conclusion: Compared with elderly people without dementia, Chinese elderly people with dementia had more caries experience and poorer oral hygiene in Hong Kong. They were more likely to have difficulty in performing toothbrushing.
Assessing Seasonal Nitrate Contamination by Nitrate Dual Isotopes in a Monsoon-Controlled Bay with Intensive Human Activities in South China
Authors: Li Jiacheng , Cao Ruixue , Lao Qibin , Chen Fajin , Chen Chunqing , Zhou Xin , Meng Yafei , Zhu Qingmei
Published: March 2020

Nitrate (NO3−) dual isotope analysis was performed in Zhanjiang Bay, which is a closed bay with intensive human activities in South China, to investigate seasonal changes in the main NO3− sources and their biogeochemical processes in the monsoon-controlled climate. The relatively low N/P ratios in Zhanjiang Bay suggests that nitrogen (N) is a limiting nutrient, which indicates that the increase of N is favorable for phytoplankton proliferation. However, a sufficient amount of ammonium was found in our study area owing to intensive human activities, which can support biological processes. Thus, less NO3− biological processes were found, indicating that NO3− isotopic characteristics may reveal details of the mixing from various sources. The Bayesian mixing model showed that NO3− in the upper bay originated from manure (43%), soil N (30%), N fertilizer (17%), and N precipitation (10%) during winter, which reflects the local human activities; while NO3- sources during summer were mainly N fertilizer (36%), soil N (32%), and manure (31%), indicating the source as the runoff from the upper river basin. Our results suggest that nitrate dual-isotope was very useful for tracing the main NO3− sources in the condition of the sufficient ammonium, and runoff exerted an important impact on the shift in NO3− sources between both the local source and the source from the upper river basin during the two seasons in this monsoon-controlled bay.
An Anecdotal Case Report of Chronic Lymphatic Leukemia with del(11q) Treated with Ibrutinib: Artificial Nourishment and Physical Activity Program
Authors: Sica Antonello , Sagnelli Caterina , Papa Alfonso , Ciccozzi Massimo , Sagnelli Evangelista , Calogero Armando , Martinelli Erika , Casale Beniamino
Published: March 2020

Chronic lymphatic leukemia (CLL) is the most frequent type of leukemia in western countries and when association with del(11q) is correlated with a worse prognosis. We reported the clinical case of an 80-year-old patient with CLL related to del(11q) and a BMI of 16.4 kg/m2, who presented a voluminous mass in abdominal cavity (23 × 14 × 4 cm) which occupied the whole of the mesentery and the retroperitoneal space, treated with ibrutinib, adequate nutrition, and a program of physical activity. He showed a great improvement under ibrutinib therapy and took to artificial nourishment and adequate muscle rehabilitation until he recovered his autonomy. In August 2018, a 5-days-a-week training program was started: Physical activity for at least 20 min consisting of a fast walk in the open air three times a week and a moderate physical activity in the remaining two days of at least 20 consecutive minutes (cycling at a regular pace, carrying light weights). The exercise program included also aerobic, upper and lower limb resistance training, chore stability and stretches. The physical condition further improved and remained excellent throughout the follow-up period. In December 2018, his clinical condition was quite normal; a CT showed a great decrease of all lymphoadenomegaly, and FISH test did not show del(11q). He continued to cultivate his land, while still being treated with ibrutinib. The combination of the right therapy, adequate nutrition, and muscle rehabilitation is the best solution to improve the clinical condition of old cachectic CLL del(11q) patient.
Interval Hypoxic Training Enhances Athletic Performance and Does Not Adversely Affect Immune Function in Middle- and Long-Distance Runners
Authors: Jung Won-Sang , Kim Sung-Woo , Park Hun-Young
Published: March 2020

This study evaluated the effects of intermittent interval training in hypoxic conditions for six weeks compared with normoxic conditions, on hemodynamic function, autonomic nervous system (ANS) function, immune function, and athletic performance in middle- and long-distance runners. Twenty athletes were divided into normoxic training (normoxic training group (NTG); n = 10; residing and training at sea level) and hypoxic training (hypoxic training group (HTG); n = 10; residing at sea level but training in 526-mmHg hypobaric hypoxia) groups. All dependent variables were measured before, and after, training. The training frequency was 90 min, 3 d per week for six weeks. Body composition showed no significant difference between the two groups. However, the HTG showed more significantly improved athletic performance (e.g., maximal oxygen uptake). The hemodynamic function (e.g., oxygen uptake, oxygen pulse, and cardiac output) during submaximal exercise and ANS function (e.g., standard deviation and root mean square of successive differences, high frequency, and low/high frequency) improved more in the HTG. Immune function parameters were stable within the normal range before and after training in both groups. Therefore, hypoxic training was more effective in enhancing athletic performance, and improving hemodynamic and ANS function; further, it did not adversely affect immune function in competitive runners.
Despite Low Obesity Rates, Body Mass Index Under-Estimated Obesity among Russian Police Officers When Compared to Body Fat Percentage
Authors: Heinrich Katie M. , Gurevich Konstantin G. , Arkhangelskaia Anna N. , Karazhelyaskov Oleg P. , Poston Walker S. C.
Published: March 2020

In some countries, obesity rates among police officers are higher than the general public, despite physically demanding jobs. Obesity rates based on body mass index (BMI) may lack accuracy as BMI does not directly address body composition. Since data are lacking for obesity rates among Russian police officers, this study documented and compared officer obesity rates to the adult Russian population and compared the accuracy of body mass index (BMI) for obesity classification to two direct measures of body composition. Moscow region police officers (N = 182, 84% men) underwent height, weight, waist circumference (WC), and body fat percentage (BF%) bioelectrical impedance measurements during annual medical examinations. BMI-defined obesity rates were 4.6% for men and 17.2% for women, which were >3 and >1.8 times lower than Russian adults, respectively. WC-defined obesity rates were similar to BMI (3.3% for men and 10.3% for women), but BF%-defined obesity rates were much higher (22.2% for men and 55.2% for women). Although obesity rates were lower than those found among police officers in other countries, BMI alone was not a particularly accurate method for classifying weight status among Russian police officers.
Lower Serum Fibroblast Growth Factor 21 Levels are Associated with Normal Lumbar Spine Bone Mineral Density in Hemodialysis Patients
Authors: Wu Yin-Ting , Hsu Bang-Gee , Wang Chih-Hsien , Lin Yu-Li , Lai Yu-Hsien , Kuo Chiu-Huang
Published: March 2020

Recent evidence has indicated that fibroblast growth factor 21 (FGF21) regulates longitudinal bone growth, with increased FGF21 levels leading to bone loss. The present study evaluated the relationship between bone mineral density (BMD) and serum FGF21 levels in patients undergoing hemodialysis (HD). We analyzed blood samples from 95 patients undergoing HD and measured BMD using dual-energy X-ray absorptiometry of the lumbar vertebrae (L2–L4). Serum FGF21 concentrations were determined using a commercially available enzyme-linked immunosorbent assay kit. Thirteen (11.6%) patients were found to have osteoporosis, 27 (28.4%) osteopenia, and 57 patients had normal BMD. Advanced age and decreased body mass index, height, body weight, waist circumference, and triglyceride level were associated with lower lumbar T-scores, as were increased alkaline phosphatase, urea reduction rate, fractional clearance index for urea, and FGF21 levels. Low log-FGF21, increased body mass index, increased pre-HD body weight, and increased logarithmically transformed triglycerides (log-TG) were found to be significantly and independently associated with lumbar BMD by multivariate forward stepwise linear regression analysis with adjustment for significant confounders. We conclude that high serum FGF21 level is negatively associated with BMD in patients undergoing HD.
Passive Smokers’ Support for Stronger Tobacco Control in Indonesia
Authors: Nurhasana Renny , Ratih Suci Puspita , Djaja Komara , Hartono Risky Kusuma , Dartanto Teguh
Published: March 2020

Secondhand smoke exposure in Indonesia is high, especially compared to other Southeast Asian countries. Passive smoking leads to negative impacts on health and socio-economic well-being. Therefore, increasing the price of cigarettes and, thereby, increasing barriers to access to cigarettes could be an effective way to reduce smoking prevalence and protect people from second-hand smoke. This study aims to assess passive smokers’ support for cigarette price increases in Indonesia. We perform a quantitative analysis with a cross-sectional design. The data were obtained through phone-based interviews of 1000 respondents aged 18 and older in Indonesia. Only 596 nonsmokers were included to be further analyzed in this study. This study found that 44.1% respondents have at least one family member who smokes. We considered the respondents’ age, gender, education level, employment, and the number of people living in the respondent’s household that are exposed to passive smoking. Our results demonstrate that passive smokers support stronger tobacco control such as increasing cigarette prices, regulating smoking behavior using a religious approach (Fatwa), and applying more effective pictorial health warnings.
Improving Education and Training of Dutch Major Hazard Control Inspectors: A 15 Years Longitudinal Case Study
Authors: Lindhout Paul , van der Werff Karel , Reniers Genserik L. L. M. E.
Published: March 2020

The education and training program for inspectors of Major Accident Hazard Establishments, specifically the EC Seveso III directive implicated Dutch chemical companies, changed considerably over a fifteen year period. This longitudinal, time-series cross sectional case study describes the development of the education and training program for Major Hazard Control inspectors, acting as regulators from the Labour inspectorate, belonging to the Dutch Ministry of Social Affairs and Employment. A blueprint had to be constructed in order to assess the development and quality of this program in four cross sections over time. The description highlights both the safety related content and the regulator skills parts of the program in its changing context. Professional standards, educational objectives, quality of education, evaluation method, education change process and the response to the dynamic operational environment were examined. The main findings are that the education and training program kept the same main structure over the time period while its contents were adapted to respond to external context changes. Internal evaluation of performance data and education style led to a shift in contents from theoretical knowledge towards safety management and inspection practice oriented experience related knowledge. An active teaching style, increased usage of professional standards and more systematic evaluation, starting from the blue print in this study, offer the best opportunities for further improvement. Current insights on regulatory performance lead to a recommended future perspective for the inspectors’ role to be translated into education and training: balancing empathy, inquisitiveness and support with control and enforcement, or rather: exert tough love, staying between too soft and too hard.
Shall We Dance? Dancing Modulates Executive Functions and Spatial Memory
Authors: Noguera Carmen , Carmona Dolores , Rueda Adrián , Fernández Rubén , Cimadevilla José Manuel
Published: March 2020

Background: Aging is generally considered to be related to physical and cognitive decline. This is especially prominent in the frontal and parietal lobes, underlying executive functions and spatial memory, respectively. This process could be successfully mitigated in certain ways, such as through the practice of aerobic sports. With regard to this, dancing integrates physical exercise with music and involves retrieval of complex sequences of steps and movements creating choreographies. Methods: In this study, we compared 26 non-professional salsa dancers (mean age 55.3 years, age-range 49–70 years) with 20 non-dancers (mean age 57.6 years, age-range 49–70 years) by assessing two variables: their executive functions and spatial memory performance. Results: results showed that dancers scored better that non-dancers in our tests, outperforming controls in executive functions-related tasks. Groups did not differ in spatial memory performance. Conclusions: This work suggests that dancing can be a valid way of slowing down the natural age-related cognitive decline. A major limitation of this study is the lack of fitness assessment in both groups. In addition, since dancing combines multiple factors like social contact, aerobic exercise, cognitive work with rhythms, and music, it is difficult to determine the weight of each variable.
Risk Factors and Behaviours of Schoolchildren with Myopia in Taiwan
Authors: Cheng Han-Chih , Chang Koyin , Shen Elizabeth , Luo Kai-Shin , Ying Yung-Hsiang
Published: March 2020

Importance: Because of the high prevalence of myopia in Taiwan, understanding the risk factors for its development and progression is important to public health. Background: This study investigated the risk factors for myopia and their influence on the progression of myopia in schoolchildren in Taiwan. Design: Patients’ clinical records were obtained retrospectively from ophthalmologists. Questionnaires were given to collect demographic information, family background, hours spent on daily activities, myopia progression, and treatment methods. Participants: From a regional medical hospital in northern Taiwan, 522 schoolchildren with myopia participated in the study. Written informed consent was obtained from participants of legal age or the parents or legal guardians of younger children. Methods: Multivariable regression analyses were performed. Myopia measured in cycloplegic spherical equivalent (SE) was analysed, controlling for patients’ family and demographic information as well as their daily activity behaviours. Main Outcome Results: Children with high myopic parents were more myopic. Earlier onset age of myopia was associated with a higher level of myopia and greater annual myopic progression. Children reporting longer time usage of electronic devices had greater progression of myopia. Boys tended to be more myopic than girls. Lower levels of myopia were associated with more outdoor activities, and better vision care knowledge in children and parents. Conclusions and Relevance: In addition to genetics, education and environment can influence the development of myopia. Health policies for schoolchildren should promote protective activities and vision care knowledge at a young age, to protect the eyesight of schoolchildren.
Use of Electronic Cigarettes in European Populations: A Narrative Review
Authors: Kapan A. , Stefanac S. , Sandner I. , Haider S. , Grabovac I. , Dorner T.E.
Published: March 2020

The increasing popularity of electronic cigarettes in past decades has aroused public health concern. This study aims to review the literature on the prevalence of e-cigarette use among the general adult and young populations in Europe. We searched Medline and Google Scholar from September 2019, and included “prevalence of e-cigarettes”, “electronic cigarettes” or “e-cigarettes”, and “electronic nicotine delivery system” or “vaping”. The prevalence of current e-cigarette use ranged from 0.2% to 27%, ever-use ranged from 5.5% to 56.6% and daily use ranged from 1% to 2.9%. Current smokers of conventional cigarettes showed the highest prevalence for the use of e-cigarettes, ranging from 20.4% to 83.1%, followed by ex-smokers, with ranges from 7% to 15%. The following socio-demographic factors were associated with a higher chance of using e-cigarettes: male sex and younger age groups; results for economic status were inconclusive. In European countries, there is a higher prevalence of e-cigarette use among males, adolescents and young adults, smokers of conventional cigarettes, and former smokers.
Atmospheric Pollution Exposure Increases Disease Activity of Systemic Lupus Erythematosus
Authors: Blaskievicz Paula Henriques , Silva Ageo Mario Candido , Fernandes Vander , Junior Osvaldo Borges Pinto , Shimoya-Bittencourt Walkiria , Ferreira Silvana Margarida Benevides , da Silva Cristhiane Almeida Leite
Published: March 2020

Previous studies have shown that high levels of air pollutants may increase activity of systemic lupus erythematosus (SLE). The aim of this study is to analyze the association between pollutants originating from the Brazilian Legal Amazon and SLE activity. This is a retrospective longitudinal cohort study with patients with SLE in the General Hospital in Cuiabá, Brazil. The association with SLE activity was measured using the SLE disease activity index (SLEDAI) and data on air quality—PM2.5 and CO, published on the websites of the State Department of Environment and the Center for Weather Forecasting and Climate Studies. To assess the effect of daily concentrations of pollutants on SLEDAI scores, the generalized estimation equation (GEE) model was used. A total of 32 female patients were assessed, in 96 doctor’s appointments. The average SLEDAI score was 6 points (±5.05). GEE showed an association of disease activity with both higher rates of wildfires (p = 0.021) and average CO rate (p = 0.013), but there was no statistical association between particulate levels and SLE activity. The results suggest that variations in air pollution are associated with the activity of autoimmune rheumatic diseases.
Curcumin in Health and Diseases: Alzheimer’s Disease and Curcumin Analogues, Derivatives, and Hybrids
Authors: Chainoglou Eirini , Hadjipavlou-Litina Dimitra
Published: March 2020

Worldwide, Alzheimer’s disease (AD) is the most common neurodegenerative multifactorial disease influencing the elderly population. Nowadays, several medications, among them curcumin, are used in the treatment of AD. Curcumin, which is the principal component of Curcuma longa, has shown favorable effects forsignificantly preventing or treating AD. During the last decade, the scientific community has focused their research on the optimization of therapeutic properties and on the improvement of pharmacokinetic properties of curcumin. This review summarizes bibliographical data from 2009 to 2019 on curcumin analogues, derivatives, and hybrids, as well as their therapeutic, preventic, and diagnostic applications in AD. Recent advances in the field have revealed that the phenolic hydroxyl group could contribute to the anti-amyloidogenic activity. Phenyl methoxy groups seem to contribute to the suppression of amyloid-β peptide (Aβ42) and to the suppression of amyloid precursor protein (APP) andhydrophobic interactions have also revealed a growing role. Furthermore, flexible moieties, at the linker, are crucial for the inhibition of Aβ aggregation. The inhibitory activity of derivatives is increased with the expansion of the aromatic rings. The promising role of curcumin-based compounds in diagnostic imaging is highlighted. The keto-enol tautomerism seems to be a novel modification for the design of amyloid-binding agents. Molecular docking results, (Q)SAR, as well as in vitro and in vivo tests highlight the structures and chemical moieties that are correlated with specific activity. As a result, the knowledge gained from the existing research should lead to the design and synthesis ofinnovative and multitargetedcurcumin analogues, derivatives, or curcumin hybrids, which would be very useful drug and tools in medicine for both diagnosis and treatment of AD.
Deletion and Randomization of Structurally Variable Regions in B. subtilis Lipase A (BSLA) Alter Its Stability and Hydrolytic Performance Against Long Chain Fatty Acid Esters
Authors: Martínez Ronny , Bernal Claudia , Álvarez Rodrigo , Concha Christopher , Araya Fernando , Cabrera Ricardo , Dhoke Gaurao V. , Davari Mehdi D.
Published: March 2020

The continuous search for novel enzyme backbones and the engineering of already well studied enzymes for biotechnological applications has become an increasing challenge, especially by the increasing potential diversity space provided by directed enzyme evolution approaches and the demands of experimental data generated by rational design of enzymes. In this work, we propose a semi-rational mutational strategy focused on introducing diversity in structurally variable regions in enzymes. The identified sequences are subjected to a progressive deletion of two amino acids and the joining residues are subjected to saturation mutagenesis using NNK degenerate codons. This strategy offers a novel library diversity approach while simultaneously decreasing enzyme size in the variable regions. In this way, we intend to identify and reduce variable regions found in enzymes, probably resulting from neutral drift evolution, and simultaneously studying the functional effect of said regions. This strategy was applied to Bacillus. subtilis lipase A (BSLA), by selecting and deleting six variable enzyme regions (named regions 1 to 6) by the deletion of two amino acids and additionally randomizing the joining amino acid residues. After screening, no active variants were found in libraries 1% and 4%, 15% active variants were found in libraries 2% and 3%, and 25% for libraries 5 and 6 (n = 3000 per library, activity detected using tributyrin agar plates). Active variants were assessed for activity in microtiter plate assay (pNP-butyrate), thermal stability, substrate preference (pNP-butyrate, -palmitate), and compared to wildtype BSLA. From these analyses, variant P5F3 (F41L-ΔW42-ΔD43-K44P), from library 3 was identified, showing increased activity towards longer chain p-nitrophenyl fatty acid esters, when compared to BSLA. This study allowed to propose the targeted region 3 (positions 40–46) as a potential modulator for substrate specificity (fatty acid chain length) in BSLA, which can be further studied to increase its substrate spectrum and selectivity. Additionally, this variant showed a decreased thermal resistance but interestingly, higher isopropanol and Triton X-100 resistance. This deletion-randomization strategy could help to expand and explore sequence diversity, even in already well studied and characterized enzyme backbones such as BSLA. In addition, this strategy can contribute to investigate and identify important non-conserved regions in classic and novel enzymes, as well as generating novel biocatalysts with increased performance in specific processes, such as enzyme immobilization.
Biology and Therapeutic Targets of Colorectal Serrated Adenocarcinoma; Clues for a Histologically Based Treatment against an Aggressive Tumor
Authors: Alburquerque-González Begoña , López-Calderón Fernando F. , López-Abellán María Dolores , Esteban-Gil Ángel , García-Solano José , Conesa-Zamora Pablo
Published: March 2020

Serrated adenocarcinoma (SAC) is a tumor recognized by the WHO as a histological subtype accounting for around 9% of colorectal carcinomas. Compared to conventional carcinomas, SACs are characterized by a worse prognosis, weak development of the immune response, an active invasive front and a frequent resistance to targeted therapy due to a high occurrence of KRAS or BRAF mutation. Nonetheless, several high-throughput studies have recently been carried out unveiling the biology of this cancer and identifying potential molecular targets, favoring a future histologically based treatment. This review revises the current evidence, aiming to propose potential molecular targets and specific treatments for this aggressive tumor.