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Objectives As prevalence of molar-incisor hypomineralisation varies considerably in different countries and regions, the aim of this study was to obtain representative epidemiological data for schoolchildren living in the canton of Basel-Landschaft, Switzerland. Material and methods A representative population of schoolchildren of three different age groups, i.e. 1st grade (mean age: 7.4 years), 6th grade (mean age: 12.6 years), and 9th grade (mean age: 15.7 years) visiting compulsory schools in the canton of Basel-Landschaft, Switzerland, was examined. The presence or absence of molar-incisor hypomineralisation at time of examination was recorded as well as potential influencing factors such as age group, gender, nationality, or the children’s place of residence. Results A total of 1252 schoolchildren could be included. On average, the prevalence of MIH in the study population was 14.8%. No statistically significant differences were found for nationality, gender, or place of residence. Although not statistically significant, children from the youngest age group had the highest while children from the oldest age group had the lowest MIH prevalence. Conclusion With a mean value of 14.8%, MIH prevalence among schoolchildren living in the canton of Basel-Landschaft, Switzerland, is comparable to mean values recorded globally. Clinical relevance This study represents the first study on MIH prevalence in Switzerland and also provides further evidence on potential influencing factors.

The technology for generating positive ideas is based on human experience, the need to improve the technological process or reduce the operating costs of production and the basic amount of industrial waste. The work examines the audit of industrial buildings and an over-view of advanced technologies for the production of building materials from waste. Current measurements of energy consumption, exceeding the limits and increasing the cost of re-sources require the formation of scientific and technological accents for the development of mixture combinations in the formation of building materials. In the course of the experiments, the thermal properties of polystyrene, ecowool, expanded polystyrene, mineral wool, expanded clay, ecowool with expanded clay were studied. Experiences show that standard insulation technologies do not work productively in the case of industrial buildings with minimal funding. An integrated technology for obtaining a by-product from secondary resources is needed. Waste audit at the enterprise showed the possibility of using primary building materials for the generation of by-products. The available equipment with minimal modifications makes it possible to obtain a new product during the endothermic process of expanded clay swelling. The pressing of cotton wool with a lightweight expanded clay structure allows obtaining sheet materials of the required density up to 1 by 1 m in size. The flexibility of the obtained material allows it to be cut with a cutting tool to the required volume. The possibility of obtaining materials of different densities is convenient for use in any enterprise, when issuing recommendations for increasing the thermal resistance of the shell. The conducted studies of the thermal resistance of the obtained material show the convenience of manufacturing a product to comply with the sanitary conditions of an industrial enterprise. The experiments were carried out according to standard methods. The need to transfer buildings of industrial enterprises to an energy-saving heating mode is caused by the need to reduce the operating costs of enterprises.

This is a review of current practices and upcoming developments regarding hepatocellular carcinoma (HCC). This includes a contemporary review of the diagnosis, staging, and treatment of HCC. Furthermore, the authors provide a review of certain ongoing trials and future directions of various treatment modalities for HCC.

Let $$(P_t)$$ ( P t ) be the transition semigroup of the Markov family $$(X^x(t))$$ ( X x ( t ) ) defined by SDE $$\begin{aligned} \mathrm{d}X= b(X)\mathrm{d}t + \mathrm{d}Z, \qquad X(0)=x, \end{aligned}$$ d X = b ( X ) d t + d Z , X ( 0 ) = x , where $$Z=\left( Z_1, \ldots , Z_d\right) ^*$$ Z = Z 1 , … , Z d ∗ is a system of independent real-valued Lévy processes. Using the Malliavin calculus we establish the following gradient formula $$\begin{aligned} \nabla P_tf(x)= {\mathbb {E}}\, f\left( X^x(t)\right) Y(t,x), \qquad f\in B_b({\mathbb {R}}^d), \end{aligned}$$ ∇ P t f ( x ) = E f X x ( t ) Y ( t , x ) , f ∈ B b ( R d ) , where the random field Y does not depend on f. Moreover, in the important cylindrical $$\alpha $$ α -stable case $$\alpha \in (0,2)$$ α ∈ ( 0 , 2 ) , where $$Z_1, \ldots , Z_d$$ Z 1 , … , Z d are $$\alpha $$ α -stable processes, we are able to prove sharp $$L^1$$ L 1 -estimates for Y(t, x). Uniform estimates on $$\nabla P_tf(x)$$ ∇ P t f ( x ) are also given.

Ukraine’s integration into global and European educational space, efficient implementation of educational reforms in this direction, the improvement of the quality of children and young people education is impossible without proper development of fundamental principles of marketing and management of educational innovations, first of all, among the Heads of New Ukrainian School. However, the absence of efficient mechanisms in Ukraine for training the above-mentioned Heads on marketing and management of educational innovations in New Ukrainian School negatively affects the quality of education therein and undermines the State education system in general. Therefore, the pressing issue at the current stage of education development in Ukraine is to determine the modalities and resources for the development of entrepreneurial and managerial competencies among the Heads of general secondary education institutions in the context of the power decentralization and establishment of consolidated territorial communities. With due regard for priority and pendency of the above-mentioned issue, its incomplete study, the principal objective of this study is to determine the key stages and describe the process of developing fundamental principles of marketing and management of educational innovations among the Heads of New Ukrainian School and measures for their efficient implementation. After performing analysis we have found that marketing and management of educational innovations of the Head of New Ukrainian School is his/her integrated, consistent and purposeful activity along with analysis and satisfaction of fundamentally new types of demand for educational services in the context of taking unconventional managerial decisions at his/her institution during such process. Moreover, with due regard to the aforementioned approach, we outlined the key stages of the fundamental principles development of marketing and management of educational innovations among the Heads of New Ukrainian School. So they include: the formation and control of specialists team towards development and implementation of educational innovations; determination of educational services market segment, demand for which needs to be satisfied; definition of criteria and conditions towards formation and satisfaction of demand for providing certain types of educational services etc. It is established that there are problems in the process of implementation of all above-mentioned stages, namely: absence of financial independence of educational institutions; the desire of the Heads of educational institutions to have legal and financial independence; positive managerial experience of the Heads of educational institutions regarding development and implementation of educational innovations etc. In order to avoid all above-mentioned problems, we have determined measures for the efficient implementation of marketing and management of educational innovations by the Heads of New Ukrainian School. They include: providing financial autonomy to educational institutions; performing professional training of the Heads of educational institutions, their deputies and teaching staff in general; forming new and improving the existing material and technical resources of educational institutions; implementing professionally oriented staff policy by the Heads of educational institutions in order to attract the most promising and young professionals to work as teachers etc. The scientific novelty of the obtained results is to determine, substantiate and analyze the key stages of fundamental principles development of marketing and management of educational innovations by the Heads of New Ukrainian School in the context of transformation of regulatory system and scientific and pedagogical approaches to children and young people education (shift in priorities and components of the development in this area of social activity). The obtained results of the research is the ground for studying and providing a practical solution of the problem regarding the formation of high-quality staffing and provision of fundamentally new educational services at educational institutions. Keywords: head of educational institution, educational innovations marketing of the Head of educational institution, educational innovations management of the Head of educational institution, New Ukrainian School, educational innovation. JEL Classіfіcatіon I20, I21, I22, I28, I29 Formulas: 0; fig.: 2; tabl.: 2; bibl.: 11.

The results of a parametric study of hydrodynamic stability in linear formulation of the Blasius boundary layer stability over two-layer compliant coatings are presented. In the calculations, experimental data for real silicon rubbers of several types on the elasticity modulus and the loss factor as functions of deformation frequency are used. Eight pairs of the coatings have been considered. The effect of coating layer thickness and external flow velocity on flow stability, in particular, on the behavior of the critical Reynolds number, has been studied parametrically. The regions of the critical Reynolds number of nonmonotonic nature, characteristic of most of coatings under consideration, have been found. A qualitative explanation of this effect is given. An analysis of the behavior of the critical Reynolds number allows determination of the optimal ratio of coating thicknesses for interaction with the flow.

The role of negative affect as a motivational factor in animal models of drug addiction has been underexplored in the context of cocaine self-administration. The present investigation studied the relationship between magnitude of affective response and quantity of cocaine consumed in order to clarify the affective components that drive drug use in a preclinical model. Rats self-administered (SA) cocaine 6 h/day for 14 consecutive days while their ultrasonic vocalizations (USVs) were recorded. Animals displayed an increase in 50-kHz call rates (indicating positive affect) when their drug levels were rapidly rising and an increase in 22-kHz call rates (indicating negative affect) when forced to abstain. The rate of 50-kHz calls predicted drug consumption during the 1st week of SA, but not week two. Contrarily, there was a strongly predictive positive association between rate of 22-kHz calls and amount of drug consumed during the 2nd week of SA. Experimental results indicate that after chronic cocaine self-administration, negative affect emerges when animals are deprived of expected drug during withdrawal. Moreover, the increase in USVs indicating negative affect when deprived of drug was directly related to drug intake, concurrent with a decay in the direct relationship between USVs indicating positive affect and drug intake. The present preclinical support for the widely hypothesized shift from positive to negative affect as a salient motivational factor in human drug abuse adds to growing evidence of the unique value of rat USVs for understanding the role of emotion in drug addiction.

Deformations of a compliant coating in a turbulent flow, measured previously and calculated in this work, are compared. The calculated spectral density of coating deformations at low frequencies (25–250 Hz) turned out to be almost two orders of magnitude higher than the measured one, and the rms value of the measured deformation was seven times lower than the calculated one. The transitional regime for stabilizing the forced coating oscillations under the action of a pressure wave is calculated. It is shown that the coating almost always works in the transition regime, without reaching the maximum deformation amplitudes that are characteristic of the steady state. It is concluded that it is necessary to use more complex boundary conditions that take into account the non-stationary character of the process because the amplitude of coating deformation varies in a complex way during the lifetime of organized structures moving in a turbulent boundary layer.

OBJECTIVES To identify independent predictors of and derive a risk score for invasive herpes simplex virus (HSV) infection. METHODS In this 23-center nested case-control study, we matched 149 infants with HSV to 1340 controls; all were ≤60 days old and had cerebrospinal fluid obtained within 24 hours of presentation or had HSV detected. The primary and secondary outcomes were invasive (disseminated or central nervous system) or any HSV infection, respectively. RESULTS Of all infants included, 90 (60.4%) had invasive and 59 (39.6%) had skin, eyes, and mouth disease. Predictors independently associated with invasive HSV included younger age (adjusted odds ratio [aOR]: 9.1 [95% confidence interval (CI): 3.4–24.5] 28 days), prematurity (aOR: 2.3, 95% CI: 1.1 to 5.1), seizure at home (aOR: 6.1, 95% CI: 2.3 to 16.4), ill appearance (aOR: 4.2, 95% CI: 2.0 to 8.4), abnormal triage temperature (aOR: 2.9, 95% CI: 1.6 to 5.3), vesicular rash (aOR: 54.8, (95% CI: 16.6 to 180.9), thrombocytopenia (aOR: 4.4, 95% CI: 1.6 to 12.4), and cerebrospinal fluid pleocytosis (aOR: 3.5, 95% CI: 1.2 to 10.0). These variables were transformed to derive the HSV risk score (point range 0–17). Infants with invasive HSV had a higher median score (6, interquartile range: 4–8) than those without invasive HSV (3, interquartile range: 1.5–4), with an area under the curve for invasive HSV disease of 0.85 (95% CI: 0.80–0.91). When using a cut-point of ≥3, the HSV risk score had a sensitivity of 95.6% (95% CI: 84.9% to 99.5%), specificity of 40.1% (95% CI: 36.8% to 43.6%), and positive likelihood ratio 1.60 (95% CI: 1.5 to 1.7) and negative likelihood ratio 0.11 (95% CI: 0.03 to 0.43). CONCLUSIONS A novel HSV risk score identified infants at extremely low risk for invasive HSV who may not require routine testing or empirical treatment.

To evaluate interdental biofilm reduction and composition after powered toothbrushing with a side-to-side (sonic) toothbrush compared to manual toothbrushing following single brushing exercises in periodontally healthy young adults.All participants brushed with a side-to-side toothbrush without toothpaste in four different modes: toothbrush (a) inactivated without instruction (OFF-NI), (b) activated without instruction (ON-NI), (c) inactivated with instruction (OFF-I), and (d) activated with instruction (ON-I) at consecutive visits (single brushing exercises). Before and after brushing, the Approximal Plaque Index (API) was assessed at three interdental spaces and plaque samples were taken from two interdental sites. Biofilm reduction and composition were analyzed microbiologically by total bacterial load and 16S rRNA sequencing.Thirty participants (age: 22.9 ± 2.5 years) completed the study. Most participants showed no or incomplete plaque removal assessed by API following single brushing exercises, while the frequency of API reduction was higher after ON-NI compared to OFF-I (p = 0.023). Irrespective of the brushing mode, a significant reduction of total bacterial load was detected with lower bacterial counts after OFF-NI compared to ON-NI (p = 0.008) and ON-I (p = 0.007). Biofilm composition showed slight changes in the relative abundances of bacterial taxa, regardless of the brushing mode.Manual and powered toothbrushing with a side-to-side toothbrush, with and without instruction, showed incomplete interdental biofilm removal in periodontally healthy young adults following single brushing exercises.Data has to be validated in further studies on other groups, however, in periodontally healthy young adults, additional devices seem to be necessary for sufficient interdental cleaning.

Objectives This study analysed if children of families in need of dental interventions can be identified by using the caries status of the first-born child as a predictor for caries in younger siblings of the same family. Material and methods All children aged 4 to 15 years, i.e. 13,596 children, visiting a compulsory school in the canton of Basel-Stadt, Switzerland, during the school year 2017/2018 were analysed. Total caries experience and untreated carious lesions at time of examination were recorded as well as a subset of socioeconomic factors such as gender, age, nationality, birth order and the family’s place of residence. Results A total of 6738 schoolchildren who had at least one sibling of school age could be included. Differences in caries experience and the presence of active carious lesions were found for age, nationality and place of residence but not for gender or birth order. Younger siblings had odds of having a history of caries 3.7 times higher (95% confidence interval: 3.0–4.4) and odds of having active carious lesions 3.5 times higher (95% confidence interval: 2.6–4.7) if the eldest child in the family already had caries. Conclusion Caries could be shown to be family-dependent. Younger siblings had a more than three-fold higher risk for caries if the first-born child already had carious lesions. Clinical relevance Based on these results, the caries status of the first-born child could be used as a potential indicator to detect vulnerable families and to initiate targeted preventive measures.

We report the properties of first synthesized ceramic samples of a perovskite solid solution (PbFe1/2Ta1/2O3)x[(PbMg1/3Nb2/3O3)0.7(PbTiO3)0.3]1−x, x = 0.4, 0.5. The solution is a single-phase material contrary to broadly studied multiphase (magnetic/ferroelectric) composites. Both compounds are ferroelectrics with a diffuse phase transition. An increase in x value results in a decrease in phase transition diffuseness, and an increase in the remnant polarization. 207Pb NMR shows that iron ions are nonuniformly distributed over octahedral sites and tend to random occupation of these sites in the perovskite structure. In particular, the NMR data indicate a tendency to form regions with a higher concentration of iron in the perovskite structure. Magnetic measurements show the coexistence of superparamagnetic and paramagnetic phases in the samples. The paramagnetoelectric (PME) coefficients determined by a dynamic method at room temperature have values β ≈ 0.15 × 10−15 s A−1 (x = 0.4) and 0.54 × 10−15 s A−1 (x = 0.5) at low magnetic fields (± 300 Oe), which are three thousands times larger than that in most single-phase magnetoelectric materials. Our measurements show that the main contribution to the PME response is caused by the superparamagnetic phase. Because the ME response is proportional to dM2/dH, it can be amplified by many orders of magnitude for the multiferroics with the superparamagnetic phase due to a sharp change of magnetization with the field.

Purpose: The regions of the country have different levels of Information technology development, so an important step in the implementation of the informational support policy is the assessment of the region's readiness for the transition to the digital economy. In accordance with the digitization program, an important factor is also the study of the first results of the strategy for correcting plans for further digital development. Methodology: The main methods of research in the course of conducting the given research include: analysis, description, monitoring, comparison, economic analysis, and statistical-economic method. Result: The concept of “digital economy” was considered, the characteristics of digitization within the Belgorod region were characterized, the main directions of digitization of the region and the region’s readiness to transition to a digital economy were identified. Applications: This research can be used for the universities, teachers, and students. Novelty/Originality: In this research, the model of The Development of the Digital Economy in the Belgorod Region is presented in a comprehensive and complete manner.

Results of studying stability of the Blasius boundary layer on a two-layer compliant coating in the linear formulation are reported. The computations are based on experimental parameters of viscoelasticity of a real coating, which reveal the dependences of its elasticity modulus and loss coefficient on frequency. Parametric investigations of the influence of the coating layer thicknesses and free-stream velocity on flow stability, in particular, on the critical Reynolds number, are performed. Regions of a nonmonotonic behavior of the critical Reynolds number are found, which allow one to determine the optimal thicknesses of the upper and lower layers for intense interaction with the flow. An explanation of this effect is proposed.

The defects created in commercial dental alloys during blasting with alumina particles propelled in compressed air under pressure 0.1 and 0.4 MPa have been studied using positron annihilation spectroscopy, scanning electron microscopy and X-ray diffraction. It was observed that higher pressure causes the increase in roughness and damaged zone range. The type of defects was determined as vacancies on dislocations. The defect concentration decreases with the depth and depends on alloys’ type and applied pressure. The Rutherford backscattering spectroscopy and variable energy positron beam studies indicate shallow alumina deposition in material and show that small pressure of 0.1 MPa is not enough to remove metal surface oxides completely in 60 s in all studied dental alloys.

The paper reports studies of pure, polycrystalline iron samples exposed to proton implantation with energies of 73 keV and 173 keV and doses of 3 × 1015, 1016 and 3 × 1016 cm−2. Additionally, two samples were exposed to multiple implantation with different energies and fluencies. Variable energy positron beam (VEP) was applied to the detection of irradiation-induced defects and their distribution. In turn, elastic recoil detection (ERD) method was used to estimate hydrogen concentration and its range. Analysis of VEP results was performed with VEPFIT code. The strong reduction of positron diffusion lengths in the implanted layers point out the presence of defects with high concentration. The thicknesses of these layers are in good agreement with hydrogen range evaluated by ERD. However, the presence of defects with lower concentration behind implanted zone was also detected when the free fitting was performed. The long range effect cannot be excluded.

The development of methods to prolong the shelf life of food products is an urgent and timely task. The effect of ultraviolet bactericidal irradiation on the shelf life of chopped fish semi-finished products from the low-profitable raw materials of the Northern Basin with the addition of amaranth flour has been studied. The rationale for the use of the main raw material – whiting (Micromesistius poutassou) of intact frozen, as well as components that affect the formability of semi-finished products has been presented. The laboratories' air with various groups of risk factors has been studied; the influence of ultraviolet radiation on changing the microbiological and organoleptic characteristics of chilled chopped fish semi-finished products with amaranth flour during storage and depending on production factors has been investigated. The study of the effect of bactericidal irradiation on the shelf life of the finished product has been carried out under sterile and non-sterile conditions. The results of microbiological studies of experimental samples before and after ultraviolet irradiation and their analysis compared with the control have been presented. The bactericidal dose (exposure) and the efficiency for this type of product during planar irradiation, as well as the irradiation time sufficient for the death of pathogenic microflora have been calculated. To achieve the desired bactericidal efficiency, the exposure time is 5 s. The effect of ultraviolet bactericidal irradiation on the products under investigation has been studied in accordance with the calculated data, and a comparative analysis of the results obtained has been performed. In the course of the research it has been found that the use of ultraviolet irradiation allows to increase the shelf life of cooled semi-finished products, the highest bactericidal efficiency is achieved by irradiating samples from 5 to 30 s. Further increase in exposure time for the shelf life of chopped fish semi-finished products does not have a significant effect. A scientifically grounded shelf life of chilled chopped fish semi-finished products subjected to irradiation has been established: 3 days at the temperature of 0 ± 2 °C.

Experiments on the effect of two-layer compliant coatings on the surface friction of a flat plate at flow velocities of up to 16 m/s carried out in a water tunnel are described. To document the properties of the coatings, the dynamic viscoelastic properties of used rubbers were measured in the frequency range approximately corresponding to the frequency range of wall pressure oscillations at current flow velocities. The data on characteristics of the viscoelastic properties of coatings and experimental data on interaction of coatings with the flow form a database required to test various theories and semi-empirical models for predicting the effectiveness of such interaction.

Herein, we report the fabrication of nanometer-sized reduced graphene oxide (rGO) spots by swift heavy-ion (SHI) bombardment. Such structures can be considered graphene quantum dots (QDs) embedded in a non-conducting matrix. Both the number density and the diameter of the rGO spots can be tailored by a suitable choice of irradiation parameters (i.e., ion type, fluence, and energy). The degree of graphene oxide defunctionalization by SHIs with different energies scaled well with the deposited electronic energy density. The resistance of the samples decreased nonlinearly with increasing ion dose and, at fluences above 1013 ions/cm2, was orders of magnitude lower than the initial value. An increase in the electronic stopping power of the ion resulted (i) in suppression of the structural ordering at low fluences and (ii) in increased amorphization efficiency and formation of sp-hybridized carbon chains of both polyynes and polycumulenes at high fluences. A hypothesis suggesting that the sp-C chains are bridges joining opposite sides of nanoholes created inside the track core and thus assuming the formation of a coupled QD-antidot system is presented. These phenomena were found to be absent in comparative experiments with 200 keV Xe ion irradiation, i.e., in the nuclear stopping regime.

The article studies the relevance and necessity of using by-products in the technology of food production, outlines the technology for the production of minced beef products using by-products, in particular, beef lung for the production of cutlet mass. The results of a sociological survey and analysis of consumer preferences of the population of Murmansk in relation to finished products and semi-finished products using by-products in technology are presented. A basic recipe for chopped products with by-products has been developed and its optimization has been carried out using the method of computer modeling. To search for a formulation close to the optimal formulation, the method of rotatable orthohanolic experiment planning was used. The results were processed according to standard methods using the Datafit 9.0 computer program. Experimental results of mathematical modeling are presented. The analysis of the obtained results has been carried out. It was found that chopped products made according to the specified recipe are well formed, during heat treatment they retain their shape, the taste of offal is weakly noticeable.

Caries is a complex microbial disease characterized by a multifactorial etiology. The disease is driven by cariogenic microbiota that metabolize dietary carbohydrates into acids, creating prolonged periods of low pH on the biofilm surrounding the teeth, which will result in loss of calcium from the teeth leading to carious lesions. Caries remains a major public health problem globally, ranking first for the decay of permanent teeth (2.3 billion people) and 12th for deciduous teeth (560 million children) according to the Global Burden of Disease study by the WHO in 2015. Different factors play a role in the development of the disease: (i) individual factors such as tooth morphology, saliva, and the oral microbiome, (ii) behavioral factors such as frequency and amount of fermentable carbohydrates in the host's diet and overall oral hygiene, and (iii) socioeconomic status and host genetics as well as modifying factors such as fluoride. Various models exist which explain the transition from a health-compatible oral microbiota to a cariogenic microbiota. Longitudinal studies may increase our knowledge of the oral microbial compositions in different age groups by analyzing the temporal sequence leading to carious lesions. Understanding the factors which control microbial colonization early in life as well as the keystone species that should be present or absent may provide us with strategies for the acquisition and maintenance of a health-promoting oral microbiome. Thus, the importance lies in understanding caries etiology to improve strategies for diagnosis, risk assessment, prevention, and (operative) treatment.

A high germination percentage and vigor level are two very important characteristics of high-quality seeds (Thomson, 1979). Unfortunately for agriculture and horticulture, seed germination and vigor can be markedly reduced by a number of factors, including the action of microorganisms (i.e., bacteria and fungi), viruses, and nematodes. The first part of this chapter deals with seed storage fungi, and includes information on the damage that they cause, the fungi involved, the means by which they are detected and identified, and methods for controlling them. The second part covers seedborne plant disease agents important in agriculture and horticulture, and provides examples of some of the economically important diseases caused by the various types of plant disease agents, the means by which these agents are detected and identified, and methods for controlling them. At the end of the chapter, there is an annotated bibliography of publications that provides the reader with additional information on all aspects of seed storage fungi and seedborne plant disease agents.

Caries is a complex microbial disease characterized by a multifactorial etiology. The disease is driven by cariogenic microbiota that metabolize dietary carbohydrates into acids, creating prolonged periods of low pH on the biofilm surrounding the teeth, which will result in loss of calcium from the teeth leading to carious lesions. Caries remains a major public health problem globally, ranking first for the decay of permanent teeth (2.3 billion people) and 12th for deciduous teeth (560 million children) according to the Global Burden of Disease study by the WHO in 2015. Different factors play a role in the development of the disease: (i) individual factors such as tooth morphology, saliva, and the oral microbiome, (ii) behavioral factors such as frequency and amount of fermentable carbohydrates in the host's diet and overall oral hygiene, and (iii) socioeconomic status and host genetics as well as modifying factors such as fluoride. Various models exist which explain the transition from a health-compatible oral microbiota to a cariogenic microbiota. Longitudinal studies may increase our knowledge of the oral microbial compositions in different age groups by analyzing the temporal sequence leading to carious lesions. Understanding the factors which control microbial colonization early in life as well as the keystone species that should be present or absent may provide us with strategies for the acquisition and maintenance of a health-promoting oral microbiome. Thus, the importance lies in understanding caries etiology to improve strategies for diagnosis, risk assessment, prevention, and (operative) treatment.

The aim of this study was to analyze the potential influence of long-term exposure in subinhibitory concentrations of chlorhexidine on the emergence of tolerant and/or persistent cells in oral streptococci. The two oral streptococcal isolates S. mutans ATCC25175 and S. sobrinus ATCC33402 were incubated, after long-term subinhibitory exposure to chlorhexidine, in liquid growth media containing high concentrations of chlorhexidine. A distinct subpopulation of more chlorhexidine-tolerant cells could be detected in streptococci that had been previously exposed to subinhibitory concentrations of chlorhexidine but not in the control strains. These more biocide-tolerant and persisting microbial subpopulations might also arise in vivo. Therefore, the rational and proper use of antimicrobials in dentistry, especially when used over a long period of time, is crucial.

The studies were carried out using the semi-insulating SI semiconductor. The surfaces (100) of GaAs were irradiated by the noble gases Ne+ and Kr+ ions. The fluences were in the range from 1 × 1013 cm−2 to 3 × 1016 cm−2. The dielectric functions were obtained for the virgin and implanted semiconductors. The investigations were carried out for the near surface layers applying the spectroscopic ellipsometry (SE). The chemical composition was determined using the X-ray photoelectron spectroscopy (XPS). It was found that the dielectric functions values and chemical compositions of the native oxides are different for the samples implanted with light and heavy noble gases ions.

The main methods used to measure viscoelastic properties of materials in a wide range of frequencies from 10−4 to 106 Hz are reviewed. It is demonstrated that the accuracy of many experimental methods can be increased by taking into account the form factors, which depend on the specimen type. An example of the form factor for a cylindrical specimen is provided, which is determined numerically on the basis of a two-dimensional deformation model taking into account the specimen geometry and Poisson’s ratio. The importance of the precise determination of Poisson’s ratio for rubber-like and complex-structured materials is demonstrated. Requirements to such measurements and a setup satisfying these requirements are described. Two methods for measuring viscoelastic properties of living tissues (compliance and disturbance propagation velocity) are considered. Based on the developed method of measuring these parameters for materials with a fixed thickness, methods for the creation of a unified standard of measurements of viscoelastic characteristics of living tissues are proposed.

The possibility of drag reduction due to compliant coatings of viscoelastic silicone rubbers has been tested experimentally. For this purpose, a series of single-layer coatings of various thicknesses was made of a homogeneous material. The experiments were carried out in a high-speed cavitation tunnel of Pusan National University. Dynamic viscoelastic properties of coating materials were carefully measured. The range of flow rates and coating thicknesses was calculated assuming that the coatings can interact intensively with the dynamic structures of the turbulent boundary layer only in the region of frequencies of their maximum compliance. The predicted range of coating parameters and flow velocities, in which the coatings reduce drag, is compared with experimental data.

INTRODUCTION: Dental healthcare workers are exposed to various infectious agents that may present an occupational risk. Although vaccinations rank among the most cost-effective health measures, vaccine hesitancy is present among healthcare workers. METHODS: A structured anonymous questionnaire was completed by 1111 dental healthcare workers – dentists, dental hygienists, prophylaxis assistants, dental assistants, dental technicians, and dental students. Demographic data and immunisation status, either by vaccination or by immunity after disease, were collected. Additionally, employers and employees were asked about their current workplace vaccination policy, including questions about information provided on the risk of hepatitis B (HBV) infection, whether HBV vaccination was compulsory and who paid for compulsory vaccinations. RESULTS: The overall response rate was 55.7%. Approximately half of the participants were dentists; only 17 technicians completed the questionnaire. The most common immunisation was for HBV (94.7% of participants). Only 19.2% of participants reported immunisation against human papillomavirus. Uncertainty over immunisation status was highest for Haemophilus influenzae type B (46.7%). Only a minority of participants (17.4%) received a yearly vaccination against seasonal influenza, whereas two-thirds never get vaccinated. The participants’ level of awareness related to the seven general vaccinations (HBV, influenza, measles, mumps, rubella, varicella, and tetanus) was medium to high, whereas their level of awareness related to vaccinations against HBV and influenza was medium. Half of the employees stated that they were informed about the risk of HBV at their current workplace and over three-quarters of employers indicated that they provided such information to their employees. Compulsory HBV vaccination was implemented at approximately half of the dental practices. CONCLUSION: The Swiss dental healthcare workers participating in this study had a medium level of awareness towards vaccinations. Almost all participants were vaccinated against HBV, but they were particularly hesitant about the seasonal influenza vaccination. As a considerable number of participants was unaware of their immunisation status, more comprehensive information on infectious diseases, vaccination and prevention is essential.

Study objective We determine the optimal correction factor for cerebrospinal fluid WBC counts in infants with traumatic lumbar punctures. Methods We performed a secondary analysis of a retrospective cohort of infants aged 60 days or younger and with a traumatic lumbar puncture (cerebrospinal fluid RBC count ≥10,000 cells/mm3) at 20 participating centers. Cerebrospinal fluid pleocytosis was defined as a cerebrospinal fluid WBC count greater than or equal to 20 cells/mm3 for infants aged 28 days or younger and greater than or equal to 10 cells/mm3 for infants aged 29 to 60 days; bacterial meningitis was defined as growth of pathogenic bacteria from cerebrospinal fluid culture. Using linear regression, we derived a cerebrospinal fluid WBC correction factor and compared the uncorrected with the corrected cerebrospinal fluid WBC count for the detection of bacterial meningitis. Results Of the eligible 20,319 lumbar punctures, 2,880 (14%) were traumatic, and 33 of these patients (1.1%) had bacterial meningitis. The derived cerebrospinal fluid RBCs:WBCs ratio was 877:1 (95% confidence interval [CI] 805 to 961:1). Compared with the uncorrected cerebrospinal fluid WBC count, the corrected one had lower sensitivity for bacterial meningitis (88% uncorrected versus 67% corrected; difference 21%; 95% CI 10% to 37%) but resulted in fewer infants with cerebrospinal fluid pleocytosis (78% uncorrected versus 33% corrected; difference 45%; 95% CI 43% to 47%). Cerebrospinal fluid WBC count correction resulted in the misclassification of 7 additional infants with bacterial meningitis, who were misclassified as not having cerebrospinal fluid pleocytosis; only 1 of these infants was older than 28 days. Conclusion Correction of the cerebrospinal fluid WBC count substantially reduced the number of infants with cerebrospinal fluid pleocytosis while misclassifying only 1 infant with bacterial meningitis of those aged 29 to 60 days.

Calculation results are presented for the form factor of a flat ring in a linear formulation of the theory of elasticity. The form factor accounts for the influence of the sample dimensions and Poisson’s ratio on the modulus of elasticity being measured. The two-dimensional problem of elastic deformation of a ring with boundary conditions specified for its entire surface was solved. Six flat rings of various sizes were made and their modulus of elasticity was measured to validate the results of calculations. The dispersion of values of Young’s modulus, corrected by the calculated form factor, did not exceed 2.5%, which corresponds to the range of error of measurement methods for the modulus of elasticity.