bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diagonalizable matrices whose graph is a tree: the minimum number of distinct eigenvalues and the feasibility of eigenvalue assignments
Authors: Saiago Carlos M. 
Published: December 2019

Abstract
Considered are combinatorially symmetric matrices, whose graph is a given tree, in view of the fact recent analysis shows that the geometric multiplicity theory for the eigenvalues of such matrices closely parallels that for real symmetric (and complex Hermitian) matrices. In contrast to the real symmetric case, it is shown that (a) the smallest example (13 vertices) of a tree and multiplicity list (3, 3, 3, 1, 1, 1, 1) meeting standard necessary conditions that has no real symmetric realizations does have a diagonalizable realization and for arbitrary prescribed (real and multiple) eigenvalues, and (b) that all trees with diameter < 8 are geometrically di-minimal (i.e., have diagonalizable realizations with as few of distinct eigenvalues as the diameter). This re-raises natural questions about multiplicity lists that proved subtly false in the real symmetric case. What is their status in the geometric multiplicity list case?
Influence of a Stepped Heat Curing on the Performance of High-Strength Portland Pozzolana Cement–Based Mortars
Authors: Mishra Sarad , Harish Kizhakkumodom Venkatanarayanan 
Published: December 2019

Abstract
In this study, the effects of a stepped heat curing regime originally developed for the Indian conditions on the performance properties of high strength cementitious mortars (HSCMs) containing portland pozzolana cement (PPC) were evaluated. Six mixtures were cast without and with heat curing, including two control mixtures (CM-NC and CM-HC), two silica fume mixtures (SF-NC and SF-HC), and two rice husk ash mixtures (RHA-NC and RHA-HC). Results indicated that stepped heat curing improved the 7-day strength of all mixtures substantially, but mixtures were unable to maintain very high strength levels up to 28 days. The 28-day strengths of heat-cured specimens were comparable with that of the respective normal water-cured specimens. The trends obtained for flexural, impact, and dynamic split tensile strengths supported the compressive strength trends. The durability properties of mixtures were affected to some extent by the use of high temperature for longer duration despite certain improvements in their matrices. Thus, longer durations of high temperature of 200°C up to 48 h should be avoided for HSCMs containing PPC. Under normal water and heat curing, the addition of SF and RHA lowered the early-age compressive strength of HSCMs, whereas at 28 days, their strength and durability improved. In addition, the performances of SF and RHA mixtures were comparable to each other.
Analysis of Helmet Damage and Associated Head Injuries Arising from Real-World Equestrian Fall Accidents
Authors: Clark J. Michio , Connor Thomas A. , Williams Claire , Clissold Jonathan , McGoldrick Adrian , Hill Jerry , Annaidh Aisling Ni , Gilchrist Michael D. 
Published: December 2019

Abstract
There is significant difference between the loading conditions used to certify equestrian helmets and the environment in which they are commonly used. This may affect their ability to provide adequate protection against head injury during a riding accident. The efficacy of helmet performance under real-world riding conditions can be judged by examining physical damage to the helmet during an impact, along with details of any head injury that may have been sustained by the rider. The present study considered the influence of different impact events on helmet damage sustained during real-world equestrian racing and eventing accidents. Video analysis of the accidents and assessment of the corresponding helmets allowed helmet damage to be matched to impacts. From a total of 1,119 accident videos and 218 inspected helmets, there was a total of 18 cases for which both the helmet and unobstructed video views of the accident sequence were available, along with details of any injuries sustained by the rider. All 18 cases involved the riders falling from their horses and impacting their heads against the turf. For 7 of the 18 cases, head impacts occurred in which a rider’s head was also either kicked, crushed, or stomped on by a horse: those subsequent impacts led to significant helmet damage, suggesting that the helmets provided protection for the riders during those secondary and tertiary impacts. Surprisingly, 11 of the 18 cases involved only a fall for which none of the helmets had any evident damage, despite 6 of those cases involving diagnosed concussions and 1 hematoma. This indicates that traumatic brain injury can occur in equestrian sports even while the rider wears a helmet, which suggests that there is scope to further improve the ability of equestrian helmets to protect against concussion when riders fall and impact their head against turf.
Identification of the Genetic Requirements for Zinc Tolerance and Toxicity inSaccharomyces cerevisiae
Authors: Zhao Yun-ying , Cao Chun-lei , Liu Ying-li , Wang Jing , Li Jie , Li Shi-yun , Deng Yu 
Published: December 2019

AbstractZinc is essential for almost all living organisms, since it serves as a crucial cofactor for transcription factors and enzymes. However, it is toxic to cell growth when present in excess. The present work aims to investigate the toxicity mechanisms induced by zinc stress in yeast cells. To this end, 108 yeast single-gene deletion mutants were identified sensitive to 6 mM ZnCl2 through a genome-wide screen. These genes were predominantly related to the biological processes of vacuolar acidification and transport, polyphosphate metabolic process, cytosolic transport, the process utilizing autophagic mechanism. A result from the measurement of intracellular zinc content showed that 64 mutants accumulated higher intracellular zinc under zinc stress than the wild-type cells. We further measured the intracellular ROS (reactive oxygen species) levels of 108 zinc-sensitive mutants treated with 3 mM ZnCl2. We showed that the intracellular ROS levels in 51 mutants were increased by high zinc stress, suggesting their possible involvement in regulating ROS homeostasis in response to high zinc. The results also revealed that excess zinc could generate oxidative damage and then activate the expression of several antioxidant defenses genes. Taken together, the data obtained indicated that excess zinc toxicity might be mainly due to the high intracellular zinc levels and ROS levels induced by zinc stress in yeast cells. Our current findings would provide a basis to understand the molecular mechanisms of zinc toxicity in yeast cells.
Probiotic Bifidobacterium Lactis Bacteria Inhibit the Invasion Phenotype of Shigella Dysenteriae Induced By Invasion Plasmid Antigen C
Authors: Mirfarsi Maryamsadat , Mehrabian Sedighe , Siasi Torbati Elham 
Published: December 2019

Background and Aims: Shigellosis is an acute gastroenteritis and Invasion plasmid antigen C (IpaC) is the first effector protein for Shigella invasion of intestinal cells. Among lactic acid bacteria, Bifidobacterium lactis (B. lactis) has received increasing attention for protection of a potential host against gastrointestinal infections. The aim of this study was to investigate the inhibitory activity of B. lactis against Shigella dysenteriae (S. dysenteriae) harboring IpaC gene strains from clinical specimens. Materials and Methods: Sixty stool samples of patients with bloody diarrhea were collected from three teaching hospitals in Tehran and subjected to further analysis for the identification of Shigella colonies by biochemical tests. DNA was assessed for IpaC gene by polymeraese chain reaction (PCR). Furthermore, IpaC gene expression analysis by real-time PCR was carried out to investigate whether probiotic B. lactis can inhibit the invasion phenotype of S. dysenteriae induced by IpaC. Results: Analysis of gene expression in S. dysenteriae harboring IpaC gene strains showed the expression of IpaC gene in treated S. dysentery with B. lactis being much lower than that of non-treated group (p<0.000). The results revealed that B. lactis at the concentration of 500 μg/ml bears strong inhibitory activity on the growth of S. dysenteriae by decreasing IpaC expression. Conclusions: Our results revealed the positive role of B. lactis in reducing the expression of the ipaC gene and inhibition of epithelial cell invasion by S. dysenteriae. Therefore, probiotics can be used as a complementary biotherapeutic agent in severe Shigella infection.
Genotyping of Acanthamoeba Species Isolated from Keratitis Patients by PCR Sequencing Methods in Tehran, Iran
Authors: Nayeri Chegeni Tooran , Ghaffarifar Fatemeh , Pirestani Majid , Khoshzaban Fariba , Dalimi Asl Abdolhosein , Maspi Nahid 
Published: December 2019

Background and Aims: Amoebae of the genus Acanthamoeba are unicellular amphizoic opportunistic pathogens that may cause fatal granulomatous encephalitis, eye keratitis, amebic pneumonitis and skin nodules as well as abscesses in humans and animals. Acanthamoeba keratitis is caused by trauma to the eye, contaminated cleaning solutions and the use of contact lenses. The aim of the present study was to identify the genotypes of Acanthamoeba in all patients with a clinical diagnosis of Acanthamoeba keratitis referring to eye clinic in Tehran using polymerase chain reaction (PCR). Materials and Methods: In this study, samples were collected from 35 patients who had referred to the eye clinic and were cultured on 1.5% non-nutrient agar. DNA was extracted, and then PCR amplification was performed using genus specific primers. Sequencing analysis and basic local alignment search tool search were conducted to determine the genotypes. Phylogenetic tree was generated using maximum likely algorithm in phylogenetic program MEGA version 6. Results: Eight cases were positive for Acanthamoeba using genus specific primer pairs. All specimens were reported as genotype T4. Conclusions: Determination of genotypes showed all isolates belonging to genotype T4; this abundance may be due to its higher prevalence in the environment or its greater virulence. However, further analysis of clinical and environmental samples is necessary to clarify this property.
In Vitro Evaluation of Antifungal Activity of Three Traditionally Used Medicinal Plants; Umbilicus Intermedius Boiss, Cuminum Cyminum and Zingiber Officinale Extracts
Authors: Takesh Ameneh , Fatahinia Mahnaz , Mahmoudabadi Ali Zarei 
Published: December 2019

Background and Aims: The study aimed to determine the effectiveness of three medicinal plant extracts on fungi with three methods and to compare methods. Material and methods: This study examined the antifungal properties of cumin (Cuminum cyminum L), ginger (Zingiber officinale Roscoe) and Nafe Venus (Umbilicus intermedius boiss) extracts against fungi including, Aspergillus spp., Penicillium spp., Mucor spp., Stemphylium spp., Drechslera spp., Alternaria spp., Cladosporium spp., and Aureobasidium pullulans. Furthermore, 17 candida isolates including, C. albicans, C. glabrata and C. dubliniensis were tested. In the present study two methods of disc diffusion method, agar wells diffusion method were used for assay. Then, the mixing with culture medium method was used for assessment of the antifungal activity of extracts against Alternaria sp.(as black mold), A. terreus (as hyaline mold) and C. albicans (as yeast) to compare methods as well. Results: No fungi were susceptible to extracts in disc diffusion method and agar wells diffusion method. But, this study showed that in mixing with culture medium method, cumin extract has valuable anti-fungal property and Umbilicus intermedius boiss has the inhibitory properties against the black fungi. Furthermore, it is found that mixing with culture medium method is more efficient than disc and agar well diffusion methods. Alternaria sp. and C. albicans were susceptible and resistant to all extracts. Conclusions: it is found that mixing with culture medium method is more efficient than disc and agar well diffusion methods and inhibitory potency of the extracts varies according to the type of extraction and their concentration.
Neutrophil Gelatinase-associated Lipocalin Value in Patients' Urine with Gram Positive Cocci Infection in the Urinary Tract
Authors: Saadi Somayeh , Tabatabaei Seyed Mahdi , Hooshmandi Zahra , Salehizadeh Somayeh 
Published: December 2019

Background and Aims: This study aimed to investigate the amount of Neutrophil gelatinase-associated lipocalin (NGAL) in patients' urine with Grampositive cocci infections Materials and Methods: The microbial culture was prepared from 100 urine samples and the results were recorded. The genus and bacterial were species identified and an antibiogram test was conducted to investigate their resistance. Human Lipocalin /NGAL enzyme-linked immunosorbent assay test was used. To analyze the data, Tukey and One Way ANOVA tests were used. Results: The highest mean of NGAL in the patient group was related to the men's category with 8.77, and the gender had a significant impact on the mean of NGAL. White blood cells has a significant impact on the mean of NGAL (p<0.05). The negative significance of the mean value also indicates the amount of NGAL being higher in the patient group. Conclusions: These data suggest a relationship between the amount of NGAL with white blood cells value in patients who present urinary infection of Grampositive cocci. NGAL value plays an important role as an adjuvant and surrogate marker in early diagnosis of urinary tract infections and acute renal damage in line with microbiological investigations.
Honey Bee Dry Venom Reduces Hepatitis B Virus Surface Antigen Secretion in PLC/PRF/5 Cell Line
Authors: Khani Hussein , Ghorbani Mahdi , Nojoomi Farshad , Mohebbi Alireza 
Published: December 2019

Background and Aims: Currently, many efforts are directed toward functional Hepatitis B virus (HBV) treatment. This is achievable by suppression of HBV surface antigen (HBsAg) secretion. In this regard, use of natural products has been the areas of interest by scientific communities. Materials and Methods: Dried Honey Bee venom was extracted for assessing its anti-HBsAg secretion potential. Hepatoma cell-derived PLC/PRF/5 was propagated in complete medium. The cell line was treated by a serial dilution of Bee venom. Cell cytotoxicity (IC50) was measured by MTT colorimetric assay at three post-treatment times. HBsAg secretion was evaluated from PLC/PRF/5 supernatant treated by under-cytotoxic concentrations of Bee venom by using enzyme-linked immunosorbent assay. Results: The results indicated that dried Bee venom extract is able to reduce secretion of HBsAg from the cell line with Selectivity Index (SI) of eight. Reduced levels of HBsAg were in dose-dependent manner and it was in its lower concentrations at 8 ppm after 12 hr post treatment. The IC50 was observed to be 63.78 ppm. Conclusions: The Bee venom has anti-HBV activity. The way we used under-cytotoxic concentration of Bee venom, the HBsAg secretion was restored after 24 hr post treatment. Furthermore, mechanism of action of Bee venom in reducing HBsAg level needs to be further investigated.
Prothrombin Gene G20210A Variant in Angiographically Documented Patients with Coronary Artery Stenosis
Authors: Pourgholi Leyla , Goodarzynejad Hamidreza , Ziaee Shayan , Zare Elmira , Jalali Arash , Boroumand Mohammadali 
Published: December 2019

Background: Studies on the association between the prothrombin G20210A variant and coronary artery disease (CAD) risk are inconclusive. This study aimed to investigate the possible association between the G20210A variant in the prothrombin gene and documented CAD and its severity.
Methods: This study enrolled 1460 patients who were consecutively admitted for elective coronary angiography. Via the standard angiographic techniques, coronary angiographies were done and the presence and severity of CAD were determined through the clinical vessel score and the Gensini score. Prothrombin G20210A genotypes were identified using PCR-RFLP.
Results: This cross-sectional study was performed on 953 men and 507 women at a mean age of 58.21±10.33 years. The median and the interquartile range for the Gensini score were not statistically significantly different between the wild (GG) and mutant (AA+GA) genotypes (P=0.440). The association between the G20210A polymorphism and the severity of CAD with respect to the vessel score also showed no significant linear trend of higher numbers of diseased vessels (P= 0.765 for the Mantel–Haenszel test of linear trend) in the AA+GA genotype as compared with the GG genotype.
Conclusion: Our data failed to confirm the hypothesis that the G20210A variant mutation may be a significant determinant of CAD risk or its severity.

J Teh Univ Heart Ctr 2019;14(4):150-155

This paper should be cited as: Pourgholi L, Goodarzynejad H, Ziaee S, Zare E, Jalali A, Boroumand M. Prothrombin Gene G20210A Variant in Angiographically Documented Patients with Coronary Artery Stenosis. J Teh Univ Heart Ctr 2019;14(4):150-155.
Development of Pacemaker Lead Thrombosis in a Patient with Atrial Fibrillation during Apixaban Treatment
Authors: Adar Adem , Önalan Orhan , Cakan Fahri 
Published: December 2019

Apixaban was introduced in clinical use for nonvalvular atrial fibrillation as an alternative to warfarin. There is a dearth of information regarding apixaban use in patients suffering from atrial fibrillation with intracardiac foreign bodies such as pacemaker leads. In this report, we describe a 72-year-old female patient with a complaint of weakness in both legs of a few days’ duration. She was detected to have a thrombus over the pacemaker lead and inside the left atrial appendage during apixaban treatment. After the discontinuation of apixaban and the commencement of warfarin, the thrombus was resolved. Our case is the first report to show that apixaban treatment (5 mg, twice daily) may not prevent the development of pacemaker lead thrombosis in patients with atrial fibrillation.

J Teh Univ Heart Ctr 2019;14(4):183-186

This paper should be cited as: Adem Adar, Orhan Önalan, Fahri Cakan. Development of Pacemaker Lead Thrombosis in a Patient with Atrial Fibrillation during Apixaban Treatment. J Teh Univ Heart Ctr 2019;14(4):183-186
The Relationship between Occupational Stress and Mental Health in Central Bafgh Iron Workers
Authors: Afkhami Aghda Mohammad , Afkhami Aghda Faezeh , Abdollahi Masoomeh , Falahati Maryam , Moahammad Mirzaee Hossein 
Published: December 2019

Introduction: Occupational stress is one of the most important phenomena in the workplace. Mental health, as an important factor in all personal, social, and occupational life aspects, is one of the areas of interest in mental health. The purpose of this study was to determine the relationship between job stress and mental health among workers of central iron ore in Bafgh City, Iran.
Methods: This was a descriptive correlational study. The statistical population included 2400 people (1600 workers and 800 employees) working in central Bafgh iron ore in 2014. The sample size was estimated as 331 using the Morgan and Krejcie table. Approximately, 216 persons were employed in the labor sector and 115 in the employment sector. Data collection tools included the Goldberg general health questionnaire (GHQ) and Depression Anxiety Stress Scales (DASS). The DASS was designed in three parts. The first part included demographic data (7 items). The second section had 28 questions and dealt with the participants' general health status. The third part included 42 questions and was about occupational stress. Later, Spss21 was used and Pearson correlation coefficient and regression tests were run to analyze the data and test the hypotheses.
Results: The results showed that mental health was higher in employees, while job stress was higher among the workers. This indicated a significant association between job stress and mental health in both employees and workers. However, regarding the demographic variables, only gender was related to mental health and rest of the demographic variables had no significant relationship with mental health and job stress (5≥participants).
Conclusion: Occupational stress was related to mental health in employees and workers; this can affect the level of production and product quality. Furthermore, occupational tress and mental health not only affect the workers and employees, but also expose the society and other people at risk. Consequently, it is necessary to plan and render different services at the occupation environment to decrease job stress and improve the current situation.
Determining Job Burnout Dimensions of Fars Province Gas Company Engineers
Authors: Bagherpour Iman , Feylizadeh Mohammad Reza 
Published: December 2019

Introduction: The growth of population and the irregular development of cities have increased the consumption of natural gas, which requires the development of a gas network and the installation of branches for consumers, which has led to an increase in the speed of work and stress of engineers supervising the gas company. Burnout is one of the diseases that occur in stressful jobs. Occupational burnout mediates the relationship between occupational requirements and health. The aim of this study was to determine the dimensions of burnout in supervisory engineers of Fars Province Gas Company.
Methods and Materials: The present study was a descriptive-correlational study performed on 50 out of 100 supervisory engineers in Fars Gas Company during a 3-month period. The method of data collection was self-made questionnaire and the part of emotional and job fatigue was assessed using Maslach burnout questionnaire. The content validity of the questionnaire was assessed qualitatively using the panel of experts and the reliability of the questionnaire was calculated by Cronbach's alpha. Data were analyzed by SPSS 21 software.
Results : Disease records showed that back pain (52درصد), foot pain (23درصد) and ocular disorders (32درصد) were the most common musculoskeletal disorders among observers. The results of multiple linear regression analysis showed that there is a significant relationship between psychological factors and work stress with marital status, number of children, disease records, housing status and environmental and biological factors (P <0.05) and due to high work stress Emotional exhaustion and subsequent stress are observed by supervising engineers, causing job burnout and depression among them. The mean emotional exhaustion among the participants was 96.2درصد.
Conclusion: The results of the study showed that more than 78.55درصد of the observers considered unsatisfactory health status. The deficiency and inadequacy of personal protective equipment and psychological problems, emotional exhaustion and stress are more evident among the subjects and require more basic measures in this regard. There was a significant relationship (P <0.05) between the studied areas and the components of psychiatric periodontal examinations with skeletal disorders (P <0.05).