bluuebunny/crossref_metadata_2025_split huggingface dataset:
Age as a determining variable in the practice or abandonment of physical exercise among young people
Authors: Portela-Pino Iago , Valverde-Esteve Teresa , Martínez-Patiño María José 
Published: June 2021

Background
Numerous studies have reported a gradual decline in the practice of physical exercise with age, confirming high dropout rates in the adolescent period. The aim of this study was to investigate the motivation or barriers that lead to greater or lesser adherence to physical exercise among children and adolescents.

Methods
In this study, 1,081 individuals volunteered to participate [239 children (age: 10.89 ± .66 years) and 842 adolescents (age: 14.9 ± 1.75 years)]. For this purpose, we used the Self-Report on Motivation for Exercising (AMPEF) and Self-Report on Barriers to Exercising (ABPEF) questionnaires.

Results
The most significant motivational factors in the practice of physical exercise (in both children and adolescents) are competition, social recognition and challenge (t = -16.02, p < .001), prevention and positive health (t = 5.24, p < .001) and affiliation, fun and well-being (t = -19.54, p < .001), while the barriers focus on fatigue and laziness (t = -13.20, p < .001) and body image and physical-social anxiety (t = -5.71, p < .001). It is also observed that adolescents showed significantly higher motivation than children and greater presence of barriers in the practice of physical exercise.

Conclusions
The age is a determining variable to include in preventive and intervention programs for the practice of physical exercise.
Burnout among medical students of a medical college in Kathmandu; A cross-sectional study
Authors: Shrestha Dhan Bahadur , Katuwal Nagendra , Tamang Ayush , Paudel Agrima , Gautam Anu , Sharma Muna , Bhusal Ujwal , Budhathoki Pravash 
Published: June 2021

Background
Medical students are more prone to burnout than the general population and students of other faculties due to the demanding nature of medical education with limited time and resources. Burnout has a negative impact on the academics and personal life of the students which can continue into their professional life and ultimately hamper patient care. The purpose of this study is to determine the prevalence of burnout among medical students of a medical college and find its association with age, gender, and year of study.

Materials and methods
This cross-sectional study was conducted among medical students of a medical college in Kathmandu, Nepal from 14 January to 7 March, 2021. Stratified sampling followed by a simple random sampling technique was employed to select study participants. Data was collected through a self-administered questionnaire using the English version of the Oldenburg Burnout Inventory adapted for students (OLBI-S) and analyzed in STATA version 15.

Results
The prevalence of burnout was found out to be 65.9% (n = 229). And of the remaining, 12.7% were exhausted, 11.4% were disengaged and 10.0% were neither exhausted nor disengaged. Burnout had no significant association with age in years, gender, and year of study.

Conclusions
This study shows an alarming prevalence of burnout in almost two-thirds of medical students. These results indicate the necessity of employing effective strategies by relevant authorities for the mental well-being of future physicians. Further multicenter prospective studies are required for a better understanding of the prevalence and associated factors of burnout.
Factors associated with rs1801394 of the methionine synthase reductase gene polymorphism in patients with rheumatoid arthritis
Authors: Krylov M. Yu. , Gridneva G. I. , Muravyev Yu. V. 
Published: June 2021

Clinical response to methotrexate (MT) therapy in rheumatoid arthritis (RA) can be predicted on the basis of some single nucleotide polymorphisms (SNPs) of genes, involved in folate metabolism. One of these SNPs is the rs1801394 (A66G) polymorphism of the methionine synthase reductase gene (MTRR). We investigated the association of this polymorphism with the clinical characteristics of RA patients after 6 months of MT therapy. Studies of the relationship between the response to MT therapy and the rs1801394 polymorphism have not been carried out in Russia previously.Objective: to study the possible association of the rs1801394 polymorphism with the clinical characteristics of patients with RA after 6 months of MT therapy.Patients and methods. The study included 60 patients with RA who met the ACR / EULAR criteria (2010) and received≥20 mg MT per week continuously. Based on the EULAR criteria, patients were divided into two groups: group 1 (n=30) with a good (DAS28>1.2) and group 2 (n=30) with an unsatisfactory (DAS28 <1.2) response to MT therapy. Genotyping of the rs1801394 polymorphism was performed by allelic discrimination using real-time polymerase chain reaction.Results and discussion. The frequency distribution of the A66G polymorphism genotypes in both groups was similar, however, in the 2nd group with an unsatisfactory response, there was a tendency towards a higher frequency of the mutant GG genotype (p=0.067). An association of the A66G polymorphism with gender and disease duration was found. In group 1, the AG genotype was more often detected in men than in women (p=0.017). In group 2, the AG genotype was also more common in men (p=0.075). In addition, in this group, carriers of the G allele (genotypes AG and GG) had a longer duration of the disease than carriers of the AA genotype (p=0.003 and p=0.005, respectively).Conclusion. In the present study, the relationship of the studied polymorphism rs1801394 of the MTRR gene with gender and duration of RA disease was established.
Safety and efficacy of 23-valent polysaccharide pneumococcal vaccine in patients with systemic lupus erythematosus
Authors: Tarasova G. M. , Belov B. S. , Cherkasova M. V. , Aseeva E. A. , Reshetnyak T. M. , Popkova T. V. , Kosheleva N. M. 
Published: June 2021

Objective: to study the safety and efficacy of the 23-valent polysaccharide pneumococcal vaccine (PPV-23) in patients with systemic lupus erythematosus (SLE).Patients and methods. The study included 75 patients with definite diagnosis of SLE at the age of 19–68 years, 10 (13%) of them had high SLE activity, 18 (24%) – moderate, 42 (56%) – low, in 5 (7%) patients the disease was in remission. PPV-23 was injected subcutaneously in a single dose of 0.5 ml. In 60 patients the follow-up period was ≥12 months, in 15 – from 2 to 6 months. Patients were examined before and 1, 3 and 12 months after immunization.Results and discussion. In 38 (50.7%) patients, standard local vaccination reactions of mild and moderate severity were noted, in 1 (1.3%) – a general reaction of mild severity, in 2 (2.7%) – mild diarrhea during 1 day, in 1 (1.3%) – a hyperergic reaction of the Artyus phenomenon type, the symptoms were relieved within 7 days. During 12 months of follow-up, neither exacerbations of SLE, reliably associated with vaccination, nor new autoimmune phenomena, were detected. After 1 year of observation, the number of responders to vaccination was 58%, non-responders – 42%. The duration and activity of the disease, age over 50 years, glucocorticoid therapy > 10 mg per day, did not significantly affect the vaccine response. There was a decrease in the immune response in patients on biologic DMARDs (bDMARDs) therapy compared to patients without such treatment (43 and 68% of cases, respectively), p=0.058. There was no difference between rituximab and belimumab treated subjects. There was a tendency for the prevalence of vaccination responses among patients, who received bDMARDs <1 year before immunization, as well as among patients in whom this therapy was initiated after the administration of PPV-23. There was a positive trend in decrease of pneumonia, acute and exacerbations of chronic bronchitis episodes and sinusitis.Conclusion. Sufficient immunogenicity, good tolerability and clinical efficacy of PPV-23 in patients with SLE, including those who received combined immunosuppressive therapy, have been shown. The use of bDMARDs reduces the number of patients with a vaccine response. The number of responders to vaccination increases when immunization is carried out before the initiation of therapy with bDMARDs or when this therapy is initiated <1 year before immunization. Further long-term prospective studies in large patient cohorts are required.
Heterogeneity of the mild cognitive impairment syndrome (specialized outpatient service data analysis)
Authors: Lokshina A. B. , Zakharov V. V. , Grishina D. A. , Koberskaya N. N. , Mkhitaryan E. A. , Posohov S. I. , Yakhno N. N. 
Published: June 2021

Timely diagnosis and optimal management of patients with cognitive impairment (CI) without dementia can potentially reduce the risk of their progression to dementia. In our study, we assessed the features of mild CI (MCI) syndrome in patients with neurological disorders based on the specialized outpatient service data analysis.Objective: to analyze clinical, neuropsychological, and neuroimaging characteristics of MCI syndrome in the Russian population in real clinical practice.Patients and methods. We enrolled 515 patients (209 men and 306 women, mean age – 71.2±8.0 years) with memory and/or other cognitive complaints. Seventy healthy volunteers (25 men and 45 women, mean age – 69.5±5.71 years) without cognitive complaints and central nervous system or mental disorders were enrolled in the control group. DSM-V diagnostic criteria for mild neurocognitive disorder were used. Participants underwent comprehensive neuropsychological testing with a qualitative and quantitative assessment of the results. In some of them (29.13%), brain magnetic resonance imaging (MRI) was performed.Results and discussion. The following types of MCI were identified in study participants: monofunctional non-amnestic type (MFNAT) – 1.2%, monofunctional amnestic type (MFAT) – 12.6%, polyfunctional amnestic type (PFAT) – 22.9%, polyfunctional non-amnestic type (PFNAT) – 63.3%. We found a higher prevalence of executive dysfunction and attention deficit in PFNAT, and executive dysfunction, attention deficit, and memory decline in PFAT. Cardiovascular risk factors and signs of vascular leukoencephalopathy on MRI were more frequently observed in PFNAT and PFAT.Conclusion. The clinical and neuropsychological analysis allows us to assume the pathophysiology of CI before the development of dementia. In the Russian population, cerebrovascular insufficiency plays a significant role in the development of MCI syndrome.
Sleep disorder trends in 1988–2018 among the 25–64 years old population in Russia/Siberia (WHO MONICA Psychosocial study)
Authors: Gafarov V. V. , Gromova E. A. , Panov D. O. , Gagulin I. V. , Tripelgorn A. N. , Gafarova A. V. 
Published: June 2021

Objective: to study sleep disorders prevalence and trends among the population of Novosibirsk (age group 25–64 years) in 1988–2018.Patients and methods. We screened a representative sample of a 25–64-year-old population: in 1988–1989 (II screening: 725 men, mean age – 43.4±0.4 years, response – 71.3%; 710 women, mean age – 44.8±0.4 years, response – 72%); in 1994–1995 (III screening: 647 men, mean age – 44.3±0.4 years, response – 82.1%; 391 women, mean age – 45.4±0.4 years, response – 72.5%); in 2003–2005 (IV screening: 576 men, mean age – 54.23±0.2 years, response – 61%; 1074 women, mean age – 54.27±0.2 years, response – 72%); in 2013–2016 (V screening: 427 men, mean age – 34±0.4 years, response – 71%; 548 women, mean age – 35±0.4 years, response – 72%); in 2016–2018 (VI screening: 275 men, mean age – 49±0.4 years, response – 72%; 390 women, mean age – 45±0.4 years, response – 75%) according to the standard MONICA Psychosocial study (MOPSY) protocol. Sleep disorders in the studied population were assessed with Jenkins Sleep Questionnaire.Results and discussion. We found a high prevalence of sleep disorders among the 25–64 years old population with the following trends: decrease from 1988–1989 to 1994–1995 (men – 11 and 8.6%, women – 21.8 and 16.6% respectively); increase in 2003–2018 (men – 13.1%, women – 20.5%). An increase in sleep disorders prevalence in 2003–2018 occurred mainly due to older age groups – 45–64 years (χ2 =122.061; υ=16; p<0.001 – men; χ2 =230.626; υ=16; p<0.001 – women). In 1988–2018 there was a 2-fold increase in sleep disorders prevalence among women than men in all age groups. This increase in sleep disorders prevalence was associated with increasing age, reaching its maximum in the 55–64 age group (men: 1988–1989 – 20.8%, 1994–1995 – 12.1%, 2016–2018 – 19.7%; χ2 =41.093; υ=12; p<0.001; women: 35.8; 21.8; 24.9% respectively; χ2 =22.01; υ=12; p<0.001). Different trends were observed in 25–44 years old women in 1988–2018 and in 35–44 years old men in 2013–2016: sleep disorders prevalence decreased (25–44 years old women: in 1988–1989 – 13.7%, in 1994–1995 – 7.9%, in 2013–2016 – 5.7%; χ2 =24.715; υ=8; p<0.001; 35–44 years old women 35–44: in 1988–1989 – 17.9%, in 1994–1995 – 20%, in 2013–2016 – 14.2%, in 2016–2018 – 10.3%; χ2 =21.177; υ=12; p<0.001 respectively; men: in 1988–1989 – 9.5%, in 1994–1995 – 9.3%, in 2013–2016 – 4.2% and in 2016–2018 – 11%; χ2 =12.67; υ=12; p<0.05 respectively).Conclusion. We found a high prevalence of sleep disorders among the 25–64 years old population with the following trends: a decrease from 1988–1989 to 1994–1995; an increase in 2003–2018 mainly due to older age groups. Sleep disorders prevalence decreased in younger women in 1988–2018. There also was a 2-fold increase in sleep disorders prevalence in women than men in all age groups and with increasing age in 1988–2018.
The Gender Wage Gap among Ph.D. Holders: Evidence from Italy
Authors: Alfano Vincenzo , Cicatiello Lorenzo , Gaeta Giuseppe Lucio , Pinto Mauro 
Published: June 2021

Abstract
This paper contributes to the literature on the gender wage gap by empirically analyzing those workers who hold the highest possible educational qualification, i.e., a Ph.D. The analysis relies on recent Italian cross-sectional data collected through a survey on the employment conditions of Ph.D. holders. The Oaxaca–Blinder decomposition analysis and quantile decomposition analysis are carried out, and the selection of Ph.D. holders into employment and STEM/non-STEM fields of specialization is taken into account. Findings suggest that a gender gap in hourly wages exists among Ph.D. holders, with sizeable differences by sector of employment and field of specialization.
Anti-Mafia Law Enforcement and Lending in Mafia Lands. Evidence from Judicial Administration in Italy
Authors: Calamunci Francesca M. , De Benedetto Marco Alberto , Silipo Damiano Bruno 
Published: June 2021

Abstract
The paper analyses the impact of a preventive measure aimed at fighting the criminal organizations’ activities on the bank-firm relationship in the four Italian regions with the highest density of mafia over the period 2004–2016. Taking advantage of the staggered firm-level anti-mafia enforcement actions, we implement a difference-in-differences approach and find that after entering judicial administration mafia-infiltrated firms experience a 19 per cent contraction of bank credit and have a higher probability of being credit rationed than a matched sample of legal companies. We also find that firms confiscated from the mafia experience a negative change in some demand-driven (value of production) and supply-driven (profitability) determinants of loans. Finally, we study whether confiscation of infiltrated firms produces externalities on non-infiltrated companies, and show that banks do not reassess the overall credit risk in local markets.
Composition of low-molecular-weight glutenin subunits in common wheat (Triticum aestivum L.) and their effects on the rheological properties of dough
Authors: Franaszek Sławomir , Salmanowicz Bolesław 
Published: June 2021

Abstract
The main purpose of this research was the identification and characterization of low-molecular-weight glutenin subunit (LMW-GS) composition in common wheat and the determination of the effect of these proteins on the rheological properties of dough. The use of capillary zone electrophoresis and reverse-phase high-performance liquid chromatography has made it possible to identify four alleles in the Glu-A3 and Glu-D3 loci and seven alleles in the Glu-B3 locus, encoding LMW-GSs in 70 varieties and breeding lines of wheat tested. To determine the technological quality of dough, analyses were performed at the microscale using a TA.XT Plus Texture Analyzer. Wheat varieties containing the Glu-3 loci scheme (Glu-A3b, Glu-A3f at the Glu-A3 locus; Glu-B3a, Glu-B3b, Glu-B3d, Glu-B3h at the Glu-B3 locus; Glu-D3a, Glu-D3c at the Glu-D3 locus) determined the most beneficial quality parameters.
Entrepreneurial Orientation and Start-Up Performance: A Configurational Approach
Authors: Fuentelsaz Lucio , González Consuelo , da Silva Jackson Andre 
Published: June 2021

Abstract
The relationship between entrepreneurial orientation and firm performance has been the object of a number of studies, but the literature has not yet reached a consensus about the true relationship between the two variables. Previous research attributes this lack of consensus to the moderating effect of numerous variables, including those related to the firm’s environment. While the literature evaluates the direct and moderating effects of uncertainty and hostility on the relationship between entrepreneurial orientation and firm performance, no one has investigated how these environmental variables simultaneously affect this relationship. To fill this gap, we use a configurational approach to clarify the nature of the relationship between entrepreneurial orientation and firm performance and investigate how hostility and uncertainty jointly moderate this relationship. Our arguments are tested using a sample of 140 Brazilian start-ups, and we conclude that there is a positive relationship between entrepreneurial orientation and firm performance. Nevertheless, this relationship is jointly conditioned by the level of environmental hostility and uncertainty.
Ultrasound to estimate the physical-mechanical properties of tropical wood species grown in an agroforestry system
Authors: Mascarenhas Adriano Reis Prazeres , Melo Rafael Rodolfo de , Santos Pimenta Alexandre , Stangerlin Diego Martins , Corrêa Fernando Luiz de Oliveira , Sccoti Marta Silvana Volpato , Paula Edgley Alves de Oliveira 
Published: June 2021

Abstract
The great diversity of tropical wood species makes it difficult to obtain information about their technological properties. The present work employed ultrasound to estimate the physical and mechanical properties of four wood species: African mahogany (Khaya senegalensis), ‘freijó’ (Cordia goeldiana), ‘paricá’ (Schizolobium amazonicum), and teak (Tectona grandis). Nineteen-year-old adult trees were selected and harvested from an agroforestry system (AFS) located in the Brazilian Amazon. From the harvested trees, 1.5 m logs were sawn and test specimens were obtained for physical-mechanical assays. The ultrasound propagation speed (V
0) and the dynamic modulus of elasticity (E

d
) were obtained from applying ultrasound longitudinally in wood samples. Values of V
0 decreased from the lightest wood (paricá) to the heaviest (African mahogany), and E

d
presented the opposite behavior. For the physical properties, the coefficient of determination (R
2) ranged from 12 to 35% and the best linear regression models were fitted for the basic density, having V
0 and E

d
as independent variables. For the mechanical properties, the values of R
2 varied from 18 to 63% and higher correlations were found between parallel-to-grain compression strength and E

d
, and rigidity, static bending and Ed. Ultrasound presented the potential to estimate the properties of tropical wood species from the ASF.
Influence of Deep Rolling and Induction Hardening on Microstructure Evolution of Crankshaft Sections made from 38MnSiVS5 and 42CrMo4
Authors: Fischer A. , Scholtes B. , Niendorf T. 
Published: June 2021

Abstract
In order to improve properties of complex automotive components, such as crankshafts, in an application-oriented way, several surface hardening treatments can be applied. Concerning the material performance the definition of adequate process parameters influences the resulting surface properties and, thus, the effectiveness of surface hardening treatments. To analyze most relevant process-microstructure-property relationships, the present paper reports results obtained by two different well-established surface hardening procedures, i. e. deep rolling as a mechanical treatment and induction hardening as a thermal treatment. For each hardening process widely used crankshaft steel grades, i. e. a medium carbon 38MnSiVS5 microalloyed steel and a quenched and tempered 42CrMo4 were selected and thoroughly characterized upon processing, using equal parameter settings. The results reveal that deep rolling in contrast to induction hardening proves to be a less sensitive surface layer treatment with regard to small differences in the initial microstructure, the chemical composition and the applied process parameters. Differences in microstructure evolution with respect to the applied surface hardening treatment are studied and discussed for the highly stressed fillet region of automotive crankshaft sections for all conditions. In this context, high-resolution SEM-based techniques such as EBSD and ECCI are proven to be very effective for fast qualitative evaluation of induced microstructural changes.
Review on the mechanical properties and biocompatibility of titanium implant: The role of niobium alloying element
Authors: Farrahnoor Ahmad , Zuhailawati Hussain 
Published: June 2021

AbstractBiomedical titanium alloys with elastic moduli close to that of cortical bone have gained great attention in the field of bone implantation. A low modulus is desirable in an implant to prevent stress shielding, which usually leads to critical clinical issues, such as bone resorption and implant loosening. The use of β-type titanium with nontoxic alloying elements, such as niobium, as a novel candidate of implant material for replacing failed hard tissues has shown great potential. This review describes a titanium implant application alloyed with niobium and the mechanical properties and bioactivity of various titanium alloys sintered at different temperatures.
Preparation and post-treatment of silver powders for front contact pastes of silicon solar cells
Authors: Deng Dunying , Chen Zhaoyong , Hu Yongle , Tong Yonggang , Liang Xiubing 
Published: June 2021

Abstract
Corrugated-surface silver powders were prepared for front contact pastes of silicon solar cells. The effects of using different pH controlling agents on the powder diameter, morphology, and conversion of silver ions to silver powders were investigated. Silver powders with wrinkled surface and 100% conversion were prepared, and ground by using spiral jet milling and tumbling ball milling, respectively. Silver powders ground by using spiral jet milling had better size distribution, higher tap density, and corrugated surface, the tap density of silver powders ground by using spiral jet milling was 6.52 g cm–3. The silver powders were used to prepare front contact pastes of silicon solar cells, the aspect ratio of printed gridlines was 0.34.