Scanning force microscopy (SFM) is one of the most widely used techniques in biomaterials research. In addition to imaging the materials of interest, SFM enables the mapping of mechanical properties ...and biological responses with sub-nanometer resolution and piconewton sensitivity. This review aims to give an overview of using the scanning force microscope (SFM) for investigations on dental materials. In particular, SFM-derived methods such as force-distance curves (scanning force spectroscopy), lateral force spectroscopy, and applications of the FluidFM
will be presented. In addition to the properties of dental materials, this paper reports the development of the pellicle by the interaction of biopolymers such as proteins and polysaccharides, as well as the interaction of bacteria with dental materials.
Obesity and its impact on COVID-19 de Leeuw, Angélica J. M.; Oude Luttikhuis, Maureen A. M.; Wellen, Annemarijn C. ...
Journal of molecular medicine (Berlin, Germany),
07/2021, Letnik:
99, Številka:
7
Journal Article
Recenzirano
Odprti dostop
The severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) pandemic has proven a challenge to healthcare systems since its first appearance in late 2019. The global spread and devastating ...effects of coronavirus disease 2019 (COVID-19) on patients have resulted in countless studies on risk factors and disease progression. Overweight and obesity emerged as one of the major risk factors for developing severe COVID-19. Here we review the biology of coronavirus infections in relation to obesity. In particular, we review literature about the impact of adiposity-related systemic inflammation on the COVID-19 disease severity, involving cytokine, chemokine, leptin, and growth hormone signaling, and we discuss the involvement of hyperactivation of the renin-angiotensin-aldosterone system (RAAS). Due to the sheer number of publications on COVID-19, we cannot be completed, and therefore, we apologize for all the publications that we do not cite.
The symbiosis between vertically transmitted asexual endophytic fungi and grasses is common and generally considered to be mutualistic. Recent studies have accumulated evidence of negative effects of ...endophytes on plant fitness, prompting a debate on the true nature of the symbiosis. Genetic factors in each of the two partners show high variability and have a range of effects (from positive to negative) on plant fitness. In addition, interacting environmental factors might modify the nature of the symbiosis. Finally, competition and multitrophic interactions among grass consumers are influenced by endophytes, and the effects of plant neighbours or consumers could feedback to affect plant fitness. We propose a mutualism–parasitism continuum for the symbiosis between asexual endophytes and grasses, which is similar to the associations between plants and mycorrhizal fungi.
The adsorption of bovine serum albumin (BSA) on surfaces of dental enamel and of dental materials was investigated by scanning force spectroscopy. This method provides adhesion forces which can be ...measured as a function of contact time between protein and surface, pH, wettability, and isoelectric point of the surface. Whereas the chosen ceramic and composite materials resemble very well the adhesion on natural enamel, a much stronger adhesion was found for the more hydrophobic surfaces, that is, gold, titanium, poly(methyl methacrylate) (PMMA), and poly(tetrafluoroethylene) (PTFE). On hydrophilic surfaces, adhesion is mainly influenced by the electrostatic forces between protein and surface. However, the conformational change of BSA at pH values above pH 8 has to be taken into account. On the very hydrophobic PTFE surface, the special interface structure between PTFE and water plays an important role which governs BSA adhesion.
We treat optimal equidistant and optimal non-equidistant inspection times for interval censoring of exponential distributions. We provide in particular a new approach for determining the optimal ...non-equidistant inspection times. The resulting recursive formula is related to a formula for optimal spacing of quantiles for asymptotically best linear estimates based on order statistics and to a formula for optimal cutpoints by the discretisation of continuous random variables. Moreover, we show that by the censoring with the optimal non-equidistant inspection times as well as with optimal equidistant inspection times, there is no loss of information if the number of inspections is converging to infinity. Since optimal equidistant inspection times are easier to calculate and easier to handle in practice, we study the efficiency of optimal equidistant inspection times with respect to optimal non-equidistant inspection times. Moreover, since the optimal inspection times are only locally optimal, we also provide some results concerning maximin efficient designs.
The aim of this study was to examine the contamination of game meat with copper and zinc and establish whether the use of alternative (non-lead) ammunition can lead to higher or unsafe levels of ...copper and zinc in the meat of roe deer, wild boar and red deer. The research project "Safety of game meat obtained through hunting" (LEMISI) was conducted in Germany with the purpose of examining the entry of lead as well as copper and zinc into the meat of hunted game when using either lead or non-lead ammunition. The outcome of this study shows that the usage of both lead-based ammunition and alternative non-lead ammunition results in the entry of copper and zinc into the edible parts of the game. Using non-lead ammunition does not entail dangerously elevated levels of copper and zinc, so replacing lead ammunition with alternative ammunition does not introduce a further health problem with regard to these metals. The levels of copper and zinc in game meat found in this study are in the range found in previous studies of game. The content of copper and zinc in game meat is also comparable to those regularly detected in meat and its products from livestock (pig, cattle, sheep) for which the mean human consumption rate is much higher. From the viewpoint of consumer health protection, the use of non-lead ammunition does not pose an additional hazard through copper and zinc contamination. A health risk due to the presence of copper and zinc in game meat at typical levels of consumer exposure is unlikely for both types of ammunition.
Carbohydrates, for example in form of polysaccharides such as dextran are essential components of all living organisms and are involved in cell and bacterial adhesion. The latter can lead to biofilms ...which may either cause diseases or are beneficial in biofilm reactors. To utilize effects of bound carbohydrates it is required to know under which conditions they bind to solid surfaces such as dental materials or biofilm reactor walls. For this purpose one interesting question is to which amount the polysaccharides bind to the surface under a predefined condition. However, the quantification of bound carbohydrates is very difficult. A well‐known method to quantify carbohydrates in solution is the phenol‐sulfuric acid (PSA) assay. Here, this method is adapted for bound carbohydrates. This modified PSA assay delivers reproducible results and does only need a small amount of reagents and carbohydrates. In the case of dextran bound on titanium as biomaterial it delivers the expected results, that is that higher concentrations lead to a higher adsorbed amount.
Carbohydrates are essential components in biofilms and involved in bacterial adhesion. Thus it is of great importance to find out which amount of carbohydrates binds to surfaces under predefined conditions. The classical phenol‐sulfuric acid (PSA) assay is a method to quantify carbohydrates in solution. The presented modified assay allows now to determine the amount of carbohydrates which are adsorbed on a surface.
The hepatitis E virus (HEV) can cause acute and chronic hepatitis in humans. Infections with the zoonotic HEV genotype 3, which can be transmitted from infected wild boar and deer to humans, are ...increasingly detected in Europe. To investigate the spatiotemporal HEV infection dynamics in wild animal populations, a study involving 3572 samples of wild boar and three deer species from six different geographic areas in Germany over a 4‐year period was conducted. The HEV‐specific antibody detection rates increased between 2013–2014 and 2016–2017 in wild boar from 9.5% to 22.8%, and decreased in deer from 1.1% to 0.2%. At the same time, HEV‐RNA detection rates increased in wild boar from 2.8% to 13.3% and in deer from 0.7% to 4.2%. Marked differences were recorded between the investigated areas, with constantly high detection rates in one area and new HEV introductions followed by increasing detection rates in others. Molecular typing identified HEV subtypes 3c, 3f, 3i and a putative new subtype related to Italian wild boar strains. In areas, where sufficient numbers of positive samples were available for further analysis, a specific subtype dominated over the whole observation period. Phylogenetic analysis confirmed the close relationship between strains from the same area and identified closely related human strains from Germany. The results suggest that the HEV infection dynamics in wild animals is dependent on the particular geographical area where area‐specific dominant strains circulate over a long period. The virus can spread from wild boar, which represent the main wild animal reservoir, to deer, and generally from wild animals to humans.
In recent years, the pilocarpine model of temporal lobe epilepsy has become the most popular and widely used rodent model of this common and difficult-to-treat type of epilepsy. In this model, the ...cholinomimetic convulsant pilocarpine is used to induce a status epilepticus, which is followed by hippocampal damage and development of spontaneous recurrent seizures. In rats, pilocarpine is either administered alone or in combination with lithium, which allows a conspicuous reduction of the pilocarpine dose required to induce status epilepticus and results in a higher percentage of animals developing status epilepticus. In mice, lithium has only rarely been used in association with pilocarpine, which prompted us to directly compare the pilocarpine and lithium–pilocarpine models in this species. In contrast to rats, pretreatment with lithium in mice did not potentiate the convulsant effect of pilocarpine. The sequence of behavioral changes observed in mice undergoing a status epilepticus was very similar for lithium–pilocarpine compared to pilocarpine administered alone. All mice that survived status epilepticus developed epilepsy with spontaneous recurrent seizures. Epileptic mice exhibited significant increases of anxiety-related behavior and impaired learning and memory. Neuronal damage resulting from status epilepticus was essentially similar in the lithium–pilocarpine and pilocarpine models and was characterized by severe neurodegeneration in the hippocampal formation, resembling hippocampal sclerosis in mesial temporal lobe epilepsy. Mice in which pilocarpine or lithium–pilocarpine did not induce status epilepticus but only single brief seizures did not show any significant differences in behavior, spatial learning or hippocampal histology from controls. Our data demonstrate that the syndromes produced by pilocarpine and lithium–pilocarpine in mice are behaviorally and neuropathologically indistinguishable, and that both models can be used to study the relationship between seizures, neuronal damage and psychopathology.
Abstract
Background
Various methods exist for statistical inference about a prevalence that consider misclassifications due to an imperfect diagnostic test. However, traditional methods are known to ...suffer from truncation of the prevalence estimate and the confidence intervals constructed around the point estimate, as well as from under-performance of the confidence intervals’ coverage.
Methods
In this study, we used simulated data sets to validate a Bayesian prevalence estimation method and compare its performance to frequentist methods, i.e. the Rogan-Gladen estimate for prevalence,
RGE
, in combination with several methods of confidence interval construction. Our performance measures are (i) error distribution of the point estimate against the simulated true prevalence and (ii) coverage and length of the confidence interval, or credible interval in the case of the Bayesian method.
Results
Across all data sets, the Bayesian point estimate and the
RGE
produced similar error distributions with slight advantages of the former over the latter. In addition, the Bayesian estimate did not suffer from the
RGE
’s truncation problem at zero or unity. With respect to coverage performance of the confidence and credible intervals, all of the traditional frequentist methods exhibited strong under-coverage, whereas the Bayesian credible interval as well as a newly developed frequentist method by Lang and Reiczigel performed as desired, with the Bayesian method having a very slight advantage in terms of interval length.
Conclusion
The Bayesian prevalence estimation method should be prefered over traditional frequentist methods. An acceptable alternative is to combine the Rogan-Gladen point estimate with the Lang-Reiczigel confidence interval.
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