26 research outputs found

    Математическое моделирование возникновения и распространения лесных пожаров с учетом противопожарных барьеров

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    С помощью метода математического моделирования изучается процесс распространения верховых лесных пожаров при наличии противопожарных разрывов и заслонов. Математически данная задача сводится к решению уравнений Рейнольдса для турбулентного течения с учетом химических реакций. Для получения дискретного аналога использован метод контрольного объема. С помощью численных расчетов получены распределения полей скорости, температуры, концентраций кислорода, летучих продуктов пиролиза, горения и объемных долей конденсированной фазы, получены контуры распространения верховых лесных пожаров, определена зависимость размеров противопожарных разрывов и заслонов при которых верховой пожар прекращает распространение.Using the method of mathematical modeling, the propagation of high forest fires in the presence of fire breaks and barriers is studied. Mathematically, this problem reduces to solving the Reynolds equations for a turbulent flow, taking into account chemical reactions. To obtain a discrete analog, the control volume method was used. Using numerical calculations, the distributions of the fields of velocity, temperature, oxygen concentrations, volatile pyrolysis products, combustion, and volume fractions of the condensed phase, the propagation contours of upland forest fires were obtained, the dependence of the size of fire breaks and barriers at which the top fire stops propagation was determined

    Regional Disparities in Caries Experience and Associating Factors of Ghanaian Children Aged 3 to 13 Years in Urban Accra and Rural Kpando

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    (1) The objective of this socio-epidemiologic cross-sectional study was to investigate caries burdens in Ghanaian children aged 3 to 13 years. The main focus was the analysis of urban–rural disparities and associating socio-demographic and behavioural factors. (2) Standardized caries examination with documentation of decayed, missing, filled deciduous (dmft) and permanent teeth (DMFT) was conducted in 11 school facilities according to WHO guidelines. A parental questionnaire gathered data considering associating factors. Descriptive statistics were used to evaluate their influence on caries prevalence and experience using mean dmft+DMFT, Significant Caries Index (SiC), and Specific Affected Caries Index (SaC). (3) In total, 313 study participants were included (mean age 7.7 ± 3.8 years; 156 urban, 157 rural). The urban region showed slightly higher caries prevalence (40.4% vs. 38.9%). The rural region had higher caries experience in mean dmft+DMFT (1.22 ± 2.26 vs. 0.96 ± 1.58), SiC (3.52 ± 2.73 vs. 2.65 ± 1.71), and SaC (3.15 ± 2.68 vs. 2.37 ± 1.68). Lower education and occupation level of parents and rural residence were associated to higher caries values. Sugary diet showed an inverse relation with caries prevalence and oral hygiene practices supported the generally known etiologic correlation. (4) This study highlights the importance of targeting children vulnerable to caries due to social inequality with adequate preventive means. The implementation of regular dental screening and education, e.g. in schools, may be helpful

    Clinical Oral Investigations / Efficacy of desensitizing products containing 8% arginine and calcium carbonate for hypersensitivity relief in MIH-affected molars : an 8-week clinical study

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    Objectives The objective of this study was to compare the efficacy in reducing hypersensitivity in molar incisor hypomineralization (MIH)-affected molars immediately and over 8 weeks combining a single in-office application and a homed-based program with desensitizing products containing 8% arginine and calcium carbonate. Materials and methods Nineteen children with at least one MIH-affected molar with hypersensitivity were included. Hypersensitivity was assessed with an evaporative (air) stimulus and a tactile stimulus. Each child received a single in-office treatment with a desensitizing paste containing 8% arginine and calcium carbonate (elmex Sensitive Professional desensitizing paste), followed by 8 weeks of brushing twice daily with a desensitizing toothpaste containing 8% arginine, calcium carbonate with 1450 ppm fluoride (elmex Sensitive Professional toothpaste), using the elmex Sensitive Professional toothbrush. Additionally, the corresponding mouthwash (elmex Sensitive Professional mouthwash) was used. Clinical assessments were made at baseline, immediately after the in-office treatment and after 1, 2, 4 and 8 weeks of brushing twice daily. Results Fifty-six molars with an air blast hypersensitivity score of 2 or 3 (Schiff Cold Air Sensitivity Scale) were included. Application of the desensitizing paste decreased hypersensitivity significantly immediately and throughout the 8 weeks recalls (p < 0.001). Conclusions In conclusion, 8% arginine and calcium carbonate were able to reduce hypersensitivity successfully during this 8-week trial. Clinical relevance Hypersensitivity is a major complaint in patients with MIH. This is the first study evaluating the desensitizing effect of a desensitizing paste containing 8% arginine and calcium carbonate in patients with MIH.(VLID)355274

    Are There Any Common Genetic Risk Markers for Rheumatoid Arthritis and Periodontal Diseases? A Case-Control Study

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    Background. Several studies suggest that there is a biologically plausible connection between rheumatoid arthritis (RA) and periodontal diseases (PD). Both disorders are characterized as multifactorial diseases potentially sharing common risk factors. Based on the inflammatory nature of RA and PD, the impact of genetic variations of genes of the immune system on both diseases was studied in this study. Materials and Methods. We conducted a case-control study (n=201) comparing 101 RA patients suffering from periodontal disease of different severities (no/mild PD vs. severe PD) with 100 systemically healthy controls without RA and severe PD. The genotype, allele, and haplotype distributions of 22 SNPs of 13 pro- and anti-inflammatory cytokines were assessed applying sequence-specific PCR. Results. Evaluating the impact of cytokine SNPs in RA, we identified the G allele of rs1801275 in IL4Rα (p=0.043) and the G allele of rs361525 in TNFα (p=0.005) as disease-associated risk factors in bivariate analyses. In multivariate analyses, these significant associations could not be proven. The A allele of rs2430561 in IFNγ was indicative for severe periodontitis among the patients with rheumatoid arthritis (p=0.039). Investigating the impact of rs2430561 in IFNγ on comorbidity using binary logistic regression analyses, the A allele was confirmed as an independent risk factor for severe periodontal disease and RA (p=0.024). Conclusions. These results emphasize the association of genetic variations in proinflammatory cytokines (TNFα and IFNγ) and cytokine receptor (IL4Rα) and RA and periodontal diseases. In multivariate analyses, the A allele of IFNγ was proven to be a significant marker of RA and PD comorbidities. The study broadens the knowledge about disease-specific differences in genetic composition and provides an improved understanding of a possible association of both diseases

    rs2476601 in PTPN22 gene in rheumatoid arthritis and periodontitis—a possible interface?

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    Background!#!Rheumatoid arthritis (RA) and periodontitis (PD) are proven to share common risk markers, including genetic factors. In the present study we focused on genetic variants in PTPN22 (rs2476601), PADI4 (rs2240340), CTLA4 genes (rs3087243) and its impact on RA and PD.!##!Materials and methods!#!In the study 111 RA patients and 256 systemically healthy controls were involved. A subdivision of patients and controls was carried out according the severity of periodontitis (no/level 1 PD vs. level 2 PD).!##!Results!#!I. Evaluating the genetic impact on the occurrence of RA the T allele of rs2476601 (PTPN22) (bivariate: p &amp;lt; 0.001; multivariate: p = 0.018) and T allele of rs2240340 (PADI4) (bivariate: p = 0.006; multivariate: p = 0.070) were associated with an increased vulnerability to RA. II. Investigating the genetic influence on level 2 PD the T allele of rs2476601 (PTPN22) was shown to be associated with a higher susceptibility to PD within the RA group (bivariate: p = 0.043; multivariate: p = 0.024). III. The T allele of rs2476601 (PTPN22) was proven to be a significant marker of RA and level 2 PD comorbidity (bivariate: p &amp;lt; 0.001; multivariate: p = 0.028).!##!Conclusions!#!These results support the thesis that genetic variations may represent a possible link between PD and RA. The study increases knowledge about disease-specific and cross-disease genetic pattern

    Data on IL-6 c.-174 G>C genotype and allele frequencies in patients with coronary heart disease in dependence of cardiovascular outcome

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    In this data article we present data on the distribution of alleles and genotypes of the interleukin (IL)-6 c.-174 G>C polymorphism (rs 1800795) in patients with coronary heart disease (CHD) in dependence of the incidence of new cardiovascular events (combined endpoint: myocardial infarction, stroke/TIA, cardiac death, death according to stroke) within three years follow-up. Moreover, we investigated putative associations between individual expression of IL-6 genotypes and IL-6 serum level. This investigation is a subanalysis of the article entitled “The Interleukin 6 c.-174 CC genotype is a predictor for new cardiovascular events in patients with coronary heart disease within three years follow-up“ (ClinicalTrials.gov identifier: NCT01045070) (Reichert et al., 2016) [1]. Keywords: Coronary heart disease, IL-6 serum level, IL-6 polymorphism, New cardiovascular event

    Is Periodontitis a Predictor for an Adverse Outcome in Patients Undergoing Coronary Artery Bypass Grafting? A Pilot Study

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    Periodontitis is a risk factor for atherosclerosis and coronary vascular disease (CVD). This research evaluated the relationship between periodontal conditions and postoperative outcome in patients who underwent coronary artery bypass grafting (CABG). A total of 101 patients with CVD (age 69 years, 88.1% males) and the necessity of CABG surgery were included. Periodontal diagnosis was made according to the guidelines of the Centers for Disease Control and Prevention (CDC, 2007). Additionally, periodontal epithelial surface area (PESA) and periodontal inflamed surface area (PISA) were determined. Multivariate survival analyses were carried out after a one-year follow-up period with Cox regression. All study subjects suffered from periodontitis (28.7% moderate, 71.3% severe). During the follow-up period, 14 patients (13.9%) experienced a new cardiovascular event (11 with angina pectoris, 2 with cardiac decompensation, and 1 with cardiac death). Severe periodontitis was not significant associated with the incidence of new events (adjusted hazard ratio, HR = 2.6; p = 0.199). Other risk factors for new events were pre-existing peripheral arterial disease (adjusted HR = 4.8, p = 0.030) and a history of myocardial infarction (HR = 6.1, p = 0.002). Periodontitis was not found to be an independent risk factor for the incidence of new cardiovascular events after CABG surgery

    Campylobacter Species of the Oral Microbiota as Prognostic Factor for Cardiovascular Outcome after Coronary Artery Bypass Grafting Surgery

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    Background: The oral microbiota has been implicated in a variety of systemic diseases, including cardiovascular (CV) disease. The main objective of this study (DRKS-ID: DRKS00015776) was to evaluate the prognostic importance of the oral microbiota for further CV events in patients undergoing coronary artery bypass grafting surgery (3-year follow-up). Methods: In this longitudinal cohort study, 102 CV patients were enrolled, of whom 95 completed the 3-year follow-up. The CV outcome was assessed using the major adverse cardiac and cerebrovascular events criteria. To evaluate subgingival colonization, 16S rRNA genes were amplified, targeting the V3/V4 region (Illumina MiSeq). Results: Regarding the specific number of operational taxonomic units (OTUs), no significant differences in CV outcome were determined (alpha diversity, Shannon index). In linear discriminant analyses and t-tests, the disease-specific differences in the beta diversity of the microbiota composition were evaluated. It was evident that bacteria species of the genus Campylobacter were significantly more prevalent in patients with a secondary CV event (p = 0.015). This hierarchical order also includes Campylobacter rectus, which is considered to be of comprehensive importance in both periodontal and CV diseases. Conclusions: Here, we proved that subgingival occurrence of Campylobacter species has prognostic relevance for cardiovascular outcomes in CV patients undergoing coronary artery bypass grafting
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