Shear Bond Strength Evaluation of an Experimental Dentin Adhesive In Comparison With 5 Commercial Adhesives in a Dental School Setting

The aim of the in-vitro study was to evaluate the shear bond strength of a newly developed experimental dentin adhesive and compare it with the shear bond strength of different commercially available dentin adhesives in a dental school setting

Применение полномостового резонансного инвертора для ремонта специальной техники в полевых условиях

Определено, что при проведении ремонтов автотранспортной и специальной техники вдали от стационарных баз наиболее энергоемкими и трудозатратными являются сварочные работы. На основании проведенного исследования была предложена инновационная конструкция сварочного инвертора, использующего эффект резонанса, обладающая повышенной надежностью, недорогого конструктивного исполнения (в условиях серийного производства). С целью повышения надежности и удешевления предлагаемой конструкции инвертора предложен целый ряд новых подходов. Исследуется инверторный полномостовой источник сварочного тока с реализацией резонансного эффекта, обладающий стабильностью и плавностью работы, высокой надежностью, потому что схема данного преобразователя не чувствительна к перепадам питающего напряжения

The Effect of COVID-19 On Antibiotic Resistance

Over three years have passed since the beginning of the COVID-19 pandemic. During these times we have experienced significant changes in all areas of our life. In healthcare, more attention was focused on COVID-19 than other concerns. An unexpected consequence of the pandemic was a silent progression of an increased spread of multi-resistant pathogens. While antibiotic use during the pandemic varied across healthcare settings, antibiotics were prescribed for COVID-19 patients, even though antibiotics are known not to be effective against viruses.1 In dentistry, antibiotics were prescribed to prevent potential dental infections, since many dental offices were not open. Antimicrobial resistance was one of our greatest public health concerns prior to the COVID-19 pandemic, and it remains so

Hazardous Noise Level Measured in a Dental Clinic: A Comprehensive Study

This project intends to determine the amount of long term noise exposure to dentists in the modern-day dental environment. By systematically conducting noise collection within a standard dental environment, the institution can identify ways to minimize the amount of noise within the dental environment. This will provide new instruments and or resources to dentists to mitigate the overall risk of dental health professionals in relation to hearing loss over time

Activity-Independent Prespecification of Synaptic Partners in the Visual Map of Drosophila

SummarySpecifying synaptic partners and regulating synaptic numbers are at least partly activity-dependent processes during visual map formation in all systems investigated to date [1–5]. In Drosophila, six photoreceptors that view the same point in visual space have to be sorted into synaptic modules called cartridges in order to form a visuotopically correct map [6, 7]. Synapse numbers per photoreceptor terminal and cartridge are both precisely regulated [8–10]. However, it is unknown whether an activity-dependent mechanism or a genetically encoded developmental program regulates synapse numbers. We performed a large-scale quantitative ultrastructural analysis of photoreceptor synapses in mutants affecting the generation of electrical potentials (norpA, trp;trpl), neurotransmitter release (hdc, syt), vesicle endocytosis (synj), the trafficking of specific guidance molecules during photoreceptor targeting (sec15), a specific guidance receptor required for visual map formation (Dlar), and 57 other novel synaptic mutants affecting 43 genes. Remarkably, in all these mutants, individual photoreceptors form the correct number of synapses per presynaptic terminal independently of cartridge composition. Hence, our data show that each photoreceptor forms a precise and constant number of afferent synapses independently of neuronal activity and partner accuracy. Our data suggest cell-autonomous control of synapse numbers as part of a developmental program of activity-independent steps that lead to a “hard-wired” visual map in the fly brain

Nox4 Mediates Renal Cell Carcinoma Cell Invasion through Hypoxia-Induced Interleukin 6- and 8- Production

Inflammatory cytokines are detected in the plasma of patients with renal cell carcinoma (RCC) and are associated with poor prognosis. However, the primary cell type involved in producing inflammatory cytokines and the biological significance in RCC remain unknown. Inflammation is associated with oxidative stress, upregulation of hypoxia inducible factor 1-alpha, and production of pro-inflammatory gene products. Solid tumors are often heterogeneous in oxygen tension together suggesting that hypoxia may play a role in inflammatory processes in RCC. Epithelial cells have been implicated in cytokine release, although the stimuli to release and molecular mechanisms by which they are released remain unclear. AMP-activated protein kinase (AMPK) is a highly conserved sensor of cellular energy status and a role for AMPK in the regulation of cell inflammatory processes has recently been demonstrated.We have identified for the first time that interleukin-6 and interleukin-8 (IL-6 and IL-8) are secreted solely from RCC cells exposed to hypoxia. Furthermore, we demonstrate that the NADPH oxidase isoform, Nox4, play a key role in hypoxia-induced IL-6 and IL-8 production in RCC. Finally, we have characterized that enhanced levels of IL-6 and IL-8 result in RCC cell invasion and that activation of AMPK reduces Nox4 expression, IL-6 and IL-8 production, and RCC cell invasion.Together, our data identify novel mechanisms by which AMPK and Nox4 may be linked to inflammation-induced RCC metastasis and that pharmacological activation of AMPK and/or antioxidants targeting Nox4 may represent a relevant therapeutic intervention to reduce IL-6- and IL-8-induced inflammation and cell invasion in RCC

Consumption of alcohol, cigarettes and illegal substances among physicians and medical students in Brandenburg and Saxony (Germany)

<p>Abstract</p> <p>Background</p> <p>Patients regard health care professionals as role models for leading a healthy lifestyle. Health care professionals' own behaviour and attitudes concerning healthy lifestyle have an influence in counselling patients. The aim of this study was to assess consumption of alcohol, cigarettes and illegal substances among physicians and medical students in two German states: Brandenburg and Saxony.</p> <p>Methods</p> <p>Socio-demographic data and individual risk behaviour was collected by an anonymous self-administered questionnaire. Physicians were approached via mail and students were recruited during tutorials or lectures.</p> <p>Results</p> <p>41.6% of physicians and 60.9% of medical students responded to the questionnaire; more than 50% of the respondents in both groups were females. The majority of respondents consumed alcohol at least once per week; median daily alcohol consumption ranged from 3.88 g/d (female medical students) to 12.6 g/d (male physicians). A significantly higher percentage of men (p < 0.05) reported hazardous or harmful drinking compared to women. A quarter of all participating physicians and one third of all students indicated unhealthy alcohol-drinking behaviour. The majority of physicians (85.7%) and medical students (78.5%) were non-smokers. Both groups contained significantly more female non-smokers (p < 0.05). Use of illegal substances was considerably lower in physicians (5.1%) than medical students (33.0%). Male students indicated a significantly (p < 0.001) higher level of illegal drug-use compared to female students.</p> <p>Conclusion</p> <p>More than one third of the medical students and health care professionals showed problematic alcohol-drinking behaviour. Although the proportion of non-smokers in the investigated sample was higher than in the general population, when compared to the general population, medical students between 18-24 reported higher consumption of illegal substances.</p> <p>These results indicate that methods for educating and promoting healthy lifestyle, particularly with respect to excessive alcohol consumption, tobacco use and abuse of illegal drugs should be considered.</p

Evaluation of effectiveness of class-based nutrition intervention on changes in soft drink and milk consumption among young adults

<p>Abstract</p> <p>Background</p> <p>During last few decades, soft drink consumption has steadily increased while milk intake has decreased. Excess consumption of soft drinks and low milk intake may pose risks of several diseases such as dental caries, obesity, and osteoporosis. Although beverage consumption habits form during young adulthood, which has a strong impact on beverage choices in later life, nutrition education programs on beverages are scarce in this population. The purpose of this investigation was 1) to assess soft drink and milk consumption and 2) to evaluate the effectiveness of 15-week class-based nutrition intervention in changing beverage choices among college students.</p> <p>Methods</p> <p>A total of 80 college students aged 18 to 24 years who were enrolled in basic nutrition class participated in the study. Three-day dietary records were collected, verified, and analyzed before and after the intervention. Class lectures focused on healthful dietary choices related to prevention of chronic diseases and were combined with interactive hands on activities and dietary feedback.</p> <p>Results</p> <p>Class-based nutrition intervention combining traditional lecture and interactive activities was successful in decreasing soft drink consumption. Total milk consumption, specifically fat free milk, increased in females and male students changed milk choice favoring skim milk over low fat milk. (1% and 2%).</p> <p>Conclusion</p> <p>Class-based nutrition education focusing on prevention of chronic diseases can be an effective strategy in improving both male and female college students' beverage choices. Using this type of intervention in a general nutrition course may be an effective approach to motivate changes in eating behaviors in a college setting.</p

SARS-CoV-2 variant Alpha has a spike-dependent replication advantage over the ancestral B.1 strain in human cells with low ACE2 expression

Epidemiological data demonstrate that Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) Alpha and Delta are more transmissible, infectious, and pathogenic than previous variants. Phenotypic properties of VOC remain understudied. Here, we provide an extensive functional study of VOC Alpha replication and cell entry phenotypes assisted by reverse genetics, mutational mapping of spike in lentiviral pseudotypes, viral and cellular gene expression studies, and infectivity stability assays in an enhanced range of cell and epithelial culture models. In almost all models, VOC Alpha spread less or equally efficiently as ancestral (B.1) SARS-CoV-2. B.1. and VOC Alpha shared similar susceptibility to serum neutralization. Despite increased relative abundance of specific sgRNAs in the context of VOC Alpha infection, immune gene expression in infected cells did not differ between VOC Alpha and B.1. However, inferior spreading and entry efficiencies of VOC Alpha corresponded to lower abundance of proteolytically cleaved spike products presumably linked to the T716I mutation. In addition, we identified a bronchial cell line, NCI-H1299, which supported 24-fold increased growth of VOC Alpha and is to our knowledge the only cell line to recapitulate the fitness advantage of VOC Alpha compared to B.1. Interestingly, also VOC Delta showed a strong (595-fold) fitness advantage over B.1 in these cells. Comparative analysis of chimeric viruses expressing VOC Alpha spike in the backbone of B.1, and vice versa, showed that the specific replication phenotype of VOC Alpha in NCI-H1299 cells is largely determined by its spike protein. Despite undetectable ACE2 protein expression in NCI-H1299 cells, CRISPR/Cas9 knock-out and antibody-mediated blocking experiments revealed that multicycle spread of B.1 and VOC Alpha required ACE2 expression. Interestingly, entry of VOC Alpha, as opposed to B.1 virions, was largely unaffected by treatment with exogenous trypsin or saliva prior to infection, suggesting enhanced resistance of VOC Alpha spike to premature proteolytic cleavage in the extracellular environment of the human respiratory tract. This property may result in delayed degradation of VOC Alpha particle infectivity in conditions typical of mucosal fluids of the upper respiratory tract that may be recapitulated in NCI-H1299 cells closer than in highly ACE2-expressing cell lines and models. Our study highlights the importance of cell model evaluation and comparison for in-depth characterization of virus variant-specific phenotypes and uncovers a fine-tuned interrelationship between VOC Alpha- and host cell-specific determinants that may underlie the increased and prolonged virus shedding detected in patients infected with VOC Alpha

Global application of an unoccupied aerial vehicle photogrammetry protocol for predicting aboveground biomass in non‐forest ecosystems

P. 1-15Non-forest ecosystems, dominated by shrubs, grasses and herbaceous plants, provide ecosystem services including carbon sequestration and forage for grazing, and are highly sensitive to climatic changes. Yet these ecosystems are poorly represented in remotely sensed biomass products and are undersampled by in situ monitoring. Current global change threats emphasize the need for new tools to capture biomass change in non-forest ecosystems at appropriate scales. Here we developed and deployed a new protocol for photogrammetric height using unoccupied aerial vehicle (UAV) images to test its capability for delivering standardized measurements of biomass across a globally distributed field experiment. We assessed whether canopy height inferred from UAV photogrammetry allows the prediction of aboveground biomass (AGB) across low-stature plant species by conducting 38 photogrammetric surveys over 741 harvested plots to sample 50 species. We found mean canopy height was strongly predictive of AGB across species, with a median adjusted R2 of 0.87 (ranging from 0.46 to 0.99) and median prediction error from leave-one-out cross-validation of 3.9%. Biomass per-unit-of-height was similar within but different among, plant functional types. We found that photogrammetric reconstructions of canopy height were sensitive to wind speed but not sun elevation during surveys. We demonstrated that our photogrammetric approach produced generalizable measurements across growth forms and environmental settings and yielded accuracies as good as those obtained from in situ approaches. We demonstrate that using a standardized approach for UAV photogrammetry can deliver accurate AGB estimates across a wide range of dynamic and heterogeneous ecosystems. Many academic and land management institutions have the technical capacity to deploy these approaches over extents of 1–10 ha−1. Photogrammetric approaches could provide much-needed information required to calibrate and validate the vegetation models and satellite-derived biomass products that are essential to understand vulnerable and understudied non-forested ecosystems around the globe.S