Search

Mineral Trioxide Aggregate (MTA) is the gold standard for vital pulp treatment (VPT), but its superiority over novel calcium silicate-based cements in permanent teeth lacks systematic evidence. This study aimed to compare the efficacy of these materials in VPT through a network meta-analysis. A systematic search was conducted in MEDLINE, EMBASE, Cochrane Library, and Web of Science until January 20, 2024. The inclusion criteria were randomized controlled trials involving VPT with biomaterials and reversible or irreversible pulpitis diagnoses in mature permanent teeth. The primary outcome was the odds ratio (OR) of failure rates with 95% confidence intervals. In the 21 eligible trials, failure rates were significantly higher with calcium-hydroxide than MTA at six (OR 2.26 [1.52-3.36]), 12 (OR 2.53 [1.76-3.62]), and 24 months (OR 2.46 [1.60-3.79]). Failure rates for Totalfill at six (OR 1.19 [0.55-2.58]) and 12 months (OR 1.43 [0.71-2.92]), and Biodentine at six (OR 1.09 [0.66-1.78]), 12 (OR 1.21 [0.74-1.96]), and 24 months (OR 1.47 [0.81-2.68]) were not significantly different from MTA. The results were similar in the direct pulp capping subgroup, whereas, in the partial and full pulpotomy subgroup, there was not enough evidence to achieve significant differences. MTA, Biodentine, and Totalfill are the most efficient materials for VPT. However, calcium-hydroxide-based materials are not recommended in VPT. [ABSTRACT FROM AUTHOR]

Background: Women are typically diagnosed with estrogen receptor-positive breast cancer around the postmenopausal period when declining estrogen levels initiate changes in lipid profiles. Aromatase inhibitors (AI) are used to prevent the progression of cancer; however, a further reduction in estrogen levels may have detrimental effects on lipid levels, which was our working hypothesis. Methods: Our meta-analysis was conducted on the lipid profiles of postmenopausal breast cancer patients at baseline and at different treatment time points. Results: We identified 15 studies, including 1708 patients. Studies using anastrozole (ANA), exemestane (EXE), letrozole (LET), and tamoxifen (TMX) were involved. Subgroup analyses revealed that 3- and 12-month administrations of LET and EXE lead to negative changes in lipid profiles that tend to alter the lipid profile undesirably, unlike ANA and TMX. Conclusions: Our results suggest that, despite statistically significant results, EXE and LET may not be sufficient to cause severe dyslipidemia in patients without cardiovascular comorbidities according to the AHA/ACC Guideline on the Management of Blood Cholesterol. However, the results may raise the question of monitoring the effects of AIs in patients, especially those with pre-existing cardiovascular risk factors such as dyslipidemia. [ABSTRACT FROM AUTHOR]

Biocompatible Cu(II)-doped layered double hydroxide (CMA) nanoparticles were developed to combat reactive oxygen species. The 2-dimensional nanozymes showed both superoxide dismutase- and catalase-like activities in chemical assays, while proving as efficient antioxidants in the reduction of intracellular oxidative stress. The results indicate the great promise of CMA in antioxidant therapies. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the biological outcomes of bone‐level implants restored with long vs. short abutments, with regard to the 'one abutment at one time' protocol. The systematic search was performed in five databases: MEDLINE (PubMed), EMBASE, Web of Science, Scopus, and CENTRAL for randomized controlled trials up to January 14, 2023. Data were collected for marginal bone loss, bleeding on probing, and probing pocket depth by two reviewers. As effect size measure, mean difference (MD), and risk ratio (RR) were used for continuous and categorical outcomes, R‐statistics software was used for conducting statistical analyses. For quality and certainty assessment, Risk of Bias Tool 2, ROBINS‐I, and GRADE approach were used. The search resulted in 4055 records without any duplicates. After title, abstract, and full‐text analysis, eight articles were found eligible for inclusion. Bone‐level and platform‐switched implants presented less marginal bone loss after 6 months and 1 year as well, when long abutments were used (MD 0.63, 95% CI: [−0.16; 1.42]) and (MD 0.26, 95% CI: [−0.02; 0.53]). However, subgroup analysis revealed no difference in marginal bone loss when applying 'one abutment at one time' protocol (p = 0.973). Bleeding on probing and probing pocket depth presented similarly good results in both groups without almost any differences (RR 0.97, 95% CI: [0.76; 1.23]) and (MD −0.05, 95% CI: [−1.11; 1.01]). Longer abutments on bone‐level implants seem to be a favorable choice for decreasing early marginal bone loss, irrespective of connection timing. [ABSTRACT FROM AUTHOR]

We conducted a meta-analysis and systematic review to investigate the efficacy of chitosan-containing chewing gums, and to test their inhibitory effects on Streptococcus mutans. The systematic search was performed in three databases (Cochrane Library, EMBASE, and PubMed) and included English-language randomized–controlled trials to compare the efficacy of chitosan in reducing the number of S. mutans. To assess the certainty of evidence, the GRADE tool was used. Mean differences were calculated with a 95% confidence interval for one outcome: bacterial counts in CFU/mL. The protocol of the study was registered on PROSPERO, registration number CRD42022365006. Articles were downloaded (n = 6758) from EMBASE (n = 2255), PubMed (n = 1516), and Cochrane (n = 2987). After the selection process, a total of four articles were included in the qualitative synthesis and three in the quantitative synthesis. Our results show that chitosan reduced the number of bacteria. The difference in mean quantity was −4.68 × 105. The interval of the random-effects model was [−2.15 × 106; 1.21 × 106] and the prediction interval was [1.03 × 107; 9.40 × 106]. The I2 value was 98% (p = 0.35), which indicates a high degree of heterogeneity. Chitosan has some antibacterial effects when used as a component of chewing gum, but further studies are needed. It can be a promising antimicrobial agent for prevention. [ABSTRACT FROM AUTHOR]

Small catchments in mountainous regions affect downstream rivers as a primary source of sediment supply and also generate flash swasfloods, especially during extreme events. These floods have significantly shaped the catchments of small streams in the Mecsek Hills and some rural areas over the past two decades. However, there has been no previous study examining the hydromorphology of headwater catchments in low mountain environments in Hungary. The present study was meant to investigate the fundamental hydrogeomorphological properties of a first-order catchment. A customary and detailed GIS survey of 50-metre sections was aimed at deciphering flash flood vulnerability and geomorphic interrelations within a micro-watershed. We found moderate susceptibility to flash floods compared to the whole Mecsek Hills. Stable large woody debris jams were identified during the field survey as major geomorphic channel features functioning as natural barriers which drive channel evolution and reduce flood hazards. [ABSTRACT FROM AUTHOR]

Glucose-to-fructose isomerization is the key process in the reaction sequence that can lead to the total conversion of biomass into valuable fine chemicals. However, it is challenging to find an efficient, cost-effective- and waste-minimized process to produce High Fructose Corn Syrup (HFCS) without using non-green approaches. To this end, hydrotalcite (MgAl-layered double hydroxides (MgAl-LDH)) catalyzed glucose isomerization in ethanol seemed to be one of the most promising processes in the last decade. In contrast to the well-studied reaction carried out in aqueous solutions, when ethanolic solutions are used, many potentially important properties of the LDHs cannot be studied in terms of how they affect their own catalytic abilities. Neither the effect of the basic site distribution, nor the morphological aspects and the role of surface hydration have been elucidated so far. In this study, the systematic alteration of the textural and structural parameters of hydrotalcites and hydrocalumites (Ca2Al-LDH) revealed clear structure–activity-selectivity relationships. These indicate that the rate-determining factor is the hydrophilicity and the LDH surface factors affecting it, which determine the catalytic performance of the LDH catalyst more than any other factor. This is evidenced by the fact that the catalytic efficiency of hydrotalcites can be improved by reducing their basicity. When isomerizations catalyzed by the easily recyclable LDH with suitable surface features are carried out, a truly similar catalytic performance (71% glucose conversion, 83% fructose selectivity, 59% fructose yield) can be achieved as was previously described, but at a significantly lower reaction temperature (120 °C → 80 °C). [ABSTRACT FROM AUTHOR]

The Pannonian Basin was located in the southernmost, disputed limit of permafrost during the Last Glacial Maximum (LGM). In the western part of the basin, over an area of 1,200 km2, more than 150 sites with polygonal patterned ground were surveyed, and 72 sediment samples from forms identified as relict sand wedges were collected. Ten optically stimulated luminescence ages were obtained from the infills, while morphometric analyses were also carried out on satellite images. Our study revealed that the polygonal networks developed in several phases, from 15.01 ± 1.68 to 23.0 ± 1.7 ka. The polygons have an average diameter of 13–23 m and are mainly present on flat surfaces, intruding into the gravelly, alluvial host of the paleo‐Rába. Statistical analyses highlighted the short transportation period of the sandy infill and multiple sediment provenances. This study adds further data to assess the presence of permafrost or deep seasonal frost and to the interpretation of the LGM in the central European periglacial domain. [ABSTRACT FROM AUTHOR]

Background Bracket failure increases the treatment time of orthodontic therapy and burdens patients with unnecessary costs, increased chair time, and possible new appointments. Objective To compare the bond failures of different orthodontic materials based on the results of available clinical studies. Search methods A systematic search of clinical trials was performed in the Cochrane, Embase, and Pubmed databases with no limitations. The list of investigated techniques contained conventional acid-etch primer (CM-AEP), self-etch primer (SEP), self-cure resin (SCR), and simple or resin-modified glass ionomer (RM-GIC) materials and procedures. Selection criteria Clinical studies reporting the failure rate of bonded brackets after using direct adhesive techniques on buccal sites of healthy teeth were included. Data collection and analysis Bracket failure rates from eligible studies were extracted by two authors independently. Risk ratios (RRs) were pooled using the random-effects model with DerSimonian–Laird estimation. Results Thirty-four publications, involving 1221 patients, were included. Our meta-analysis revealed no significant difference in the risk of bracket failures between SEP and CM-AEP. After 6, 12, and 18 months of bonding, the values of RR were 1.04 [95% confidence interval (CI), 0.67–1.61], 1.37 (95% CI, 0.98–1.92), and 0.93 (95% CI, 0.72–1.20), respectively. At 18 months, bracket failure was 4.9 and 5.2% for SEP and CM-AEP, respectively. Heterogeneity was good or moderate (I 2 < 42.2%). The results of RM-GIC at 12 months indicated a 57% lower risk of bracket failure using SCR as compared with RM-GIC (RR: 0.38; 95% CI, 0.24–0.61). At 18 months, bracket failures for SCR and RM-GIC were 15.8 and 36.6%, respectively (RR: 0.44; 95% CI, 0.37–0.52, I 2 = 78.9%), demonstrating three to six times higher failure rate than in the case of etching primer applications. Limitations A major limitation of the present work is that the included clinical trials, with no exceptions, showed variable levels of risk of bias. Another possible problem affecting the outcome is the difference between the clustering effects of the split mouth and the parallel group bracket allocation methods. Conclusions and implications The results revealed no significant difference between SEP and CM-AEP up to 18 months after application. RM-GIC had much worse failure rates than acid-etching methods; additionally, the superiority of SCR over RM-GIC was evident, indicating strong clinical relevance. Registration Prospero with CRD42020163362. [ABSTRACT FROM AUTHOR]

Mesenchymal stem/stromal cells (MSCs) are found in almost all postnatal organs. Under appropriate environmental cues, multipotency enables MSCs to serve as progenitors for several lineage-specific, differentiated cell types. In vitro expansion and differentiation of MSCs give the opportunity to obtain hardly available somatic cells, such as neurons. The neurogenic potential of MSCs makes them a promising, autologous source to restore damaged tissue and as such, they have received much attention in the field of regenerative medicine. Several stem cell pool candidates have been studied thus far, but only a few of them showed neurogenic differentiation potential. Due to their embryonic ontology, stem cells residing in the stroma of the dental pulp chamber are an exciting source for in vitro neural cell differentiation. In this study, we review the key properties of dental pulp stem cells (DPSCs), with a particular focus on their neurogenic potential. Moreover, we summarize the various presently available methods used for neural differentiation of human DPSCs also emphasizing the difficulties in reproducibly high production of such cells. We postulate that because DPSCs are stem cells with very close ontology to neurogenic lineages, they may serve as excellent targets for neuronal differentiation in vitro and even for direct reprogramming. [ABSTRACT FROM AUTHOR]

Objectives: We aimed to conduct a systematic review on published data in order to investigate the efficacy of mouthwash products containing chlorine dioxide in halitosis. Study design: Systematic review and meta-analysis Methods: Our search was conducted on 14th October 2021. We searched the following electronic databases: MEDLINE, Embase, Scopus, Web of Science, and CENTRAL. We analysed data on adults with halitosis, included only randomised controlled trials and excluded in vitro and animal studies. The interventional groups used chlorine dioxide, and the comparator groups used a placebo or other mouthwash. Our primary outcomes were changes in organoleptic test scores (OLS) and Volatile Sulfur Compound (VSC) levels from baseline to the last available follow-up. Results: We found 325 articles in databases. After the selection process, ten articles were eligible for qualitative synthesis, and 7 RCTs with 234 patients were involved in the meta-analysis. Our findings showed a significant improvement in the parameters of the chlorine dioxide group compared to the placebo group in OLS one-day data (mean difference (MD): -0.82; 95% confidence intervals (95% CIs): [-1.04 –-0.6]; heterogeneity: I2 = 0%, p = 0.67); and one-week OLS data (MD: -0.24; 95% CIs: [-0.41 –-0.07]; I2 = 0%, p = 0.52); and also changes in H2S one-day data (standardised mean difference (SMD): -1.81; 95% CIs: [-2.52 –-1.10]); I2 = 73.4%, p = 0.02). Conclusion: Our data indicate that chlorine dioxide mouthwash may be a good supportive therapy in oral halitosis without known side effects. [ABSTRACT FROM AUTHOR]

Morphometric indices from high-resolution DEMs can contribute to the estimation of flash flood susceptibility in mountainous areas. We have screened 25 morphometric indices commonly used in literature, and based on a correlation matrix, selected those which showed the strongest relationship with flash flood generation: area (A), drainage texture (Rt), drainage density (Dd), elongation ratio (Re), form factor (Ff), lemniscate method (k), Gravelius coefficient (GC), forested area (Fa) and relief ratio (Rr). Among them Dd, Rt and Rr had a direct impact on flash flood generation, while A, Re, Fa, Ff, k and GC are in inverse relationship with the intensity of flash floods. Our summary map shows the prioritization of the watersheds on a scale of 0 to 9. The flash flood susceptibility ranking was empirically verified using hydrological data (20-year water regime obtained from 14 official stream gauges). Our conclusions only partially agree with former observations which may be explained by the particular lithology and morphology of the Mecsek Mountains. Since the lower sections of the watersheds are urbanized, for optimal watershed management more detailed GIS analyses of anthropogenic controls on flash flood hazard are needed in the future. [ABSTRACT FROM AUTHOR]

Effective oxidative transformation of toluene into valuable products was achieved under solvent‐free reaction conditions with as‐prepared nickel nanoparticles as heterogeneous catalysts in liquid phase. The crystalline structure and size of the as‐prepared nanoparticles were confirmed by X‐ray diffractometry (XRD) and dynamic light scattering (DLS). The catalytic implications of the different crystalline forms (face‐centred cubic: fcc; hexagonal close‐packed: hcp) of these nanocatalysts were investigated. The product selectivity of toluene oxidation was found to vary depending on the crystalline forms of the catalyst. Fcc nanocatalysts showed remarkable chemoselectivity (83 mol %) for the product benzyl alcohol and were readily reusable. In contrast, the hcp Ni phase showed reasonable reusability but lower chemoselectivity (29 mol %) compared to its fcc counterpart. Moreover, the simple organic solvents used had a remarkable effect on the crystal structure and phase purity of the Ni nanocrystals, which also affected the catalytic process. [ABSTRACT FROM AUTHOR]

Litz wires consist of many individual, isolated conductor strands. Certain litz wires are fabricated by simply twisting the bundle of strands, hence a wire pitch is realized. In this paper, the ac resistance of coils made of such twisted litz wire are calculated by combining two-dimensional finite element simulation and circuit laws. In so doing, the inherently three-dimensional problem can be solved at much lower computational cost. Results are presented for the current distribution, and for the alternating current resistance of coils, validated against measured data. [ABSTRACT FROM AUTHOR]

Over the past decades, in the mountainous, hilly and/or urban areas of Hungary several high-intensity storms were followed by severe flash flooding and other hydrologic consequences. The overall aim of this paper was to upgrade the national flash flood susceptibility map of Hungary first published by Czigány et al. (2011). One elementary watershed level (FFSIws) and three settlement level flash flood susceptibility maps (FFSIs) were constructed using 13 environmental factors that influence flash flood generation. FFSI maps were verified by 2,677 documented flash flood events. In total, 5,458 watersheds were delineated. Almost exactly 10% of all delineated watersheds were included into the category of extreme susceptibility. While the number of the mean-based FFSIs demonstrated a normal quasi-Gaussian distribution with very low percentages in the quintile of low and extreme categories, the maximum-based FFSIs overemphasized the proportion of settlements of high and extreme susceptibility. These two categories combined accounted for more than 50% of all settlements. The highest accuracy at 59.02% for class 5 (highest susceptibility) was found for the majority based FFSIs. The current map has been improved compared to the former one in terms of (i) a higher number of conditional factors considered, (ii) higher resolution, (iii) being settlement-based and (iv) a higher number of events used for verification. [ABSTRACT FROM AUTHOR]

Statins are used to treat hypercholesterolemia, with several pleiotropic effects. Alongside their positive effects (for example, decreasing blood pressure), they can also bring about negative effects/symptoms (such as myopathy). Their main mechanism of action is inducing apoptosis, the key step being the release of cytochrome c from the mitochondria. This can be facilitated by oxidative stress, through which glutathione is oxidized. In this research, glutathione was used as a respiratory substrate to measure the mitochondrial oxygen consumption of rat liver with an O2 electrode. The reduction of cytochrome c was monitored photometrically. Hydrophilic (pravastatin) and lipophilic (simvastatin) statins were used for the measurements. Pravastatin reduces the reduction of cytochrome c and the oxygen consumption of the mitochondria, while simvastatin, on the other hand, increases the reduction of cytochrome c and the mitochondrial oxygen consumption. The results make it seem probable that statins influence the mitochondrial oxygen consumption through cytochrome c. Simvastatin could enhance the oxidizing capacity of free cytochrome c, thereby increasing oxidative stress and thus facilitating apoptosis. The observed effects could further the understanding of the mechanism of action of statins and thereby aid in constructing optimal statin therapy for every patient. [ABSTRACT FROM AUTHOR]

The detection and quantification of antioxidant molecules is an important task in food science, the fine chemical industry and healthcare. Antioxidants help in preventing the deterioration of nutrition and healthcare products, while eliminating over-the-limit exogenic reactive species, which may lead to illnesses. In our contribution, an inexpensive and rapid method to determine the concentration of various molecular antioxidants was developed. The principle of the analysis relies on the cupric ion reducing antioxidant capacity (CuPRAC) method, which is based on the color-changing reduction of chelated Cu2+ ions. This complex was successfully immobilized on an alginate-functionalized layered double hydroxide (dLDH) nanosheet via electrostatic interactions. The synthesis conditions of alginate (NaAlg) and the cupric complex were optimized, and the optimized composite was fabricated on cellulose paper to obtain a sensing platform. The paper-based sensor was superior to the ones prepared without the dLDH support, as the limit of detection (LOD) values decreased, and the linearity ranges broadened. The results offer a single-point measurement to evaluate the antioxidant efficiency in a cuvette-based method. The superior ability of the sensor was assigned to the presence of solid dLDH particles, as they offer adsorption sites for the dissolved antioxidant molecules, which contributes significantly to the decrease of the diffusion limitation during the detection process. [ABSTRACT FROM AUTHOR]

Background: Maternal overnutrition during pregnancy predisposes the offspring to cardiometabolic diseases. Objectives: This systematic review and meta‐analysis aimed to investigate the association between maternal overnutrition and offspring's blood pressure (BP) and the effect of offspring's obesity on this association. Data sources: PubMed, EMBASE, Clinicaltrials.gov, CENTRAL. Study selection and data extraction: Human studies published in English before October 2021 were identified that presented quantitative estimates of association between maternal overnutrition just before or during pregnancy and the offspring's BP. Synthesis: Random‐effect model with the DerSimonian and Laird weighting method was used to analyse regression coefficients or mean differences. Results: After selection, 17 observational studies (140,517 mother‐offspring pairs) were included. Prepregnancy body mass index (ppBMI) showed positive correlation with BP in offspring (regression coefficient for systolic: 0.38 mmHg per kg/m2, 95% confidence interval (CI) 0.17, 0.58; diastolic: 0.10 mmHg per kg/m2, 95% CI 0.05, 0.14). These indicate 1.9 mmHg increase in systolic and 0.5 mmHg increase in diastolic BP of offspring with every 5 kg/m2 gain in maternal ppBMI. Results on coefficients adjusted for offspring's BMI also showed association (systolic: 0.08 mmHg per kg/m2, 95% CI 0.04, 0.11; diastolic: 0.03 mmHg per kg/m2, 95% CI 0.01, 0.04). Independent from ppBMI, gestational weight gain (GWG) showed positive correlation with systolic BP (systolic BP: 0.05 mmHg per kg, 95% CI 0.01, 0.09), but not after adjustment for offspring's BMI. Mean systolic BP was higher in children of mothers with excessive GWG than in those of mothers with optimal GWG (difference: 0.65 mmHg, 95% CI 0.25, 1.05). Conclusions: Independent from offspring's BMI, higher prepregnancy BMI may increase the risk for hypertension in offspring. The positive association between GWG and offspring's systolic BP is indirect via offspring's obesity. Reduction in maternal obesity and treatment of obesity in children of obese mothers are needed to prevent hypertension. [ABSTRACT FROM AUTHOR]

Introduction: At the initial part of the gastrointestinal tract, multiple tissues serve the normal function of food delivery. Periodontal structures are integral elements of these. When they deteriorate, it is extremely challenging to regenerate and reconstruct them. The conventional intervention for periodontal disease is scaling and root planning with the aim of reducing pathogenic bacteria. However, periodontal pathogens can rapidly recolonize treated areas. Probiotics have been proposed as novel tools for managing oral health by suppressing pathogenic bacteria through their anti-inflammatory effect, but the available data are controversial. Aim: Therefore, we performed a meta-analysis to study the effect of probiotics on periodontal pathogenic bacteria. Methods: The study was registered in PROSPERO under registration number CRD42018094903. A comprehensive literature search from four electronic databases (PubMed, Cochrane CENTRAL, Embase, and Web of Science) yielded nine eligible records for statistical analysis. Studies measuring bacterial counts in saliva and supra- and subgingival plaque were included. Bacterial counts were analyzed using standard mean difference (SMD) and by a random effects model with the DerSimonian–Laird estimation. Results: The results showed a significant decrease in the overall count of Aggregatibacter actinomycetemcomitans in the probiotic-treated group compared to the control at 4 weeks (SMD: −0.28; 95% CI: −0.56–−0.01; p = 0.045) but not later. Analyzing the bacterial counts in subgroups, namely, in saliva and supra- and subgingival plaque, separately, yielded no significant difference. Probiotics had no significant effect on the overall count of Porphyromonas gingivalis at 4 weeks (SMD: −0.02; 95% CI: −0.35−0.31; p = 0.914) or later. Subgroup analysis also revealed no significant difference between treatment and control groups nor did probiotics significantly decrease the overall and subgroup bacterial counts of Prevotella intermedia , Tannerella forsythia , and Fusobacterium nucleatum. Conclusion: Our data support the beneficial effect of probiotics in reducing A. actinomycetemcomitans counts, but not of other key periodontal pathogenic bacteria in periodontal disease patients. However, due to the complex mechanism associated with periodontal disease and the limitations of the available studies, there is a further need for well-designed randomized clinical trials to assess the efficacy of probiotics. [ABSTRACT FROM AUTHOR]

Herein, we report novel catalytic methodologies for protodecarboxylations and decarboxylative deuterations of carboxylic acids utilizing a silver-containing hybrid material as a heterogeneous noble metal catalyst. After an initial batch method development, a chemically intensified continuous flow process was established in a simple packed-bed system which enabled gram-scale protodecarboxlyations without detectable structural degradation of the catalyst. The scope and applicability of the batch and flow processes were demonstrated through decarboxylations of a diverse set of aromatic carboxylic acids. Catalytic decarboxylative deuterations were achieved on the basis of the reaction conditions developed for the protodecarboxylations using D2O as a readily available deuterium source. [ABSTRACT FROM AUTHOR]

Background: Amelogenesis, the formation of dental enamel, is well understood at the histomorphological level but the underlying molecular mechanisms are poorly characterized. Ameloblasts secrete enamel matrix proteins and Ca2+, and also regulate extracellular pH as the formation of hydroxyapatite crystals generates large quantities of protons. Genetic or environmental impairment of transport and regulatory processes (e.g. dental fluorosis) leads to the development of enamel defects such as hypomineralization. Aims: Our aims were to optimize the culture conditions for the three-dimensional growth of ameloblast-derived HAT-7 cells and to test the effects of fluoride exposure on HAT-7 spheroid formation. Methods: To generate 3D HAT-7 structures, cells were dispersed and plated within a Matrigel extracellular matrix scaffold and incubated in three different culture media. Spheroid formation was then monitored over a two-week period. Ion transporter and tight-junction protein expression was investigated by RT-qPCR. Intracellular Ca2+ and pH changes were measured by microfluorometry using the fluorescent dyes fura-2 and BCECF. Results: A combination of Hepato-STIM epithelial cell differentiation medium and Matrigel induced the expansion and formation of 3D HAT-7 spheroids. The cells retained their epithelial cell morphology and continued to express both ameloblast-specific and ion transport-specific marker genes. Furthermore, like two-dimensional HAT-7 monolayers, the HAT-7 spheroids were able to regulate their intracellular pH and to show intracellular calcium responses to extracellular stimulation. Finally, we demonstrated that HAT-7 spheroids may serve as a disease model for studying the effects of fluoride exposure during amelogenesis. Conclusion: In conclusion, HAT-7 cells cultivated within a Matrigel extracellular matrix form three-dimensional, multi-cellular, spheroidal structures that retain their functional capacity for pH regulation and intracellular Ca2+ signaling. This new 3D model will allow us to gain a better understanding of the molecular mechanisms involved in amelogenesis, not only in health but also in disorders of enamel formation, such as those resulting from fluoride exposure. [ABSTRACT FROM AUTHOR]

Objectives: Periodontal ligament stem cells (PDLSCs) have an underlined significance as their high proliferative capacity and multipotent differentiation provide an important therapeutic potential. The integrity of these cells is frequently disturbed by the routinely used irrigative compounds applied as periodontal or endodontic disinfectants (e.g., hydrogen peroxide (H2O2) and chlorhexidine (CHX)). Our objectives were (i) to monitor the cytotoxic effect of a novel dental irrigative compound, chlorine dioxide (ClO2), compared to two traditional agents (H2O2, CHX) on PDLSCs and (ii) to test whether the aging factor of PDLSC cultures determines cellular responsiveness to the chemicals tested. Methods: Impedimetry (concentration-response study), WST-1 assays (WST = water soluble tetrazolium salt), and morphology analysis were performed to measure changes in cell viability induced by the 3 disinfectants; immunocytochemistry of stem cell markers (STRO-1, CD90, and CD105) measured the induced mesenchymal characteristics. Results: Cell viability experiments demonstrated that the application of ClO2 does not lead to a significant decrease in viability of PLDSCs in concentrations used to kill microbes. On the contrary, traditional irrigants, H2O2, and CHX are highly toxic on PDLSCs. Aging of PLDSC cultures (passages 3 vs. 7) has characteristic effects on their responsiveness to these agents as the increased expression of mesenchymal stem cell markers turns to decreased. Conclusions and clinical relevance: While the active ingredients of mouthwash (H2O2, CHX) applied in endodontic or periodontitis management have a serious toxic effect on PDLSCs, the novel hyperpure ClO2 is less toxic providing an environment favoring dental structure regenerations during disinfectant interventions. [ABSTRACT FROM AUTHOR]

A hierarchically porous polymer (HPP) consisting of micropores (∼1 nm) within a 3D continuous mesoporous wall (∼15 nm) was used to support well-defined Pt nanoparticles (2 nm in diameter) as a heterogeneous catalyst for the Suzuki–Miyaura cross-coupling reaction in the liquid phase. The ligand-capped nanoparticles were loaded into the polymer and treated with plasma to expose the active surface. The dual porosity was essential: the block polymer-templated mesopores provided the reactants facile access to the nanoparticle center, which was firmly immobilized by the microporous surface. Compared to inorganic mesoporous silica supports, which are intrinsically susceptible to basic hydrolysis, the Pt-HPP featured higher activity for all halide leaving groups, even in green solvents, as well as excellent recyclability. Only 5% decrease in activity was observed after 10 cycles. Pt-HPP was one of the most active heterogeneous catalysts for aryl chloride substrates compared to literature Pt or Pd examples. [ABSTRACT FROM AUTHOR]

Certain complexing agents (such as D-gluconate, D-isosaccharinate, etc.) as well as actinides and lanthanides are simultaneously present in cementitious radioactive waste repositories and (in the presence of water) are capable of forming complex compounds. Such processes may immobilize radionuclides and are of importance in the thermodynamic modelling of the aqueous chemistry of waste repositories. Nd(III) is considered to be a suitable model for trivalent lanthanides and actinides, due to the similarity of their ionic radii. In the current work, solid complexes isolated from aqueous solution containing Nd(III), Ca(II) and D-gluconate (Gluc−) were investigated. In an aqueous solution containing Nd(III) and Gluc−, the formation of a precipitate was observed at pH ≥ 8. This precipitate was found to redissolve around pH ~ 11, but reprecipitated when Ca(II) ions were added to the solution. In order to gain an insight in binary and ternary aqueous systems, in the present work we report the structure of these solid complexes obtained from XRD, FT-IR, Raman, SEM-EDAX and UV-DRS measurements. The structure of these solids, where possible, was compared with those identified in solution. The compositions of these complexes are suggested to be NdGlucH−1(OH) · 2H2O and CaNdGlucH−1(OH)3 · 2H2O, respectively. In these, the chemical environment of the Nd(III) was found to be the same as that in the NdGlucH−1(OH)0(aq) solution species. [ABSTRACT FROM AUTHOR]

Objective: Compare intraoperative and postoperative outcomes of endoscopic and microscopic stapes surgery to provide objective evidence on whether the former is a better alternative than the latter.Methods: We performed a systematic review and meta-analysis for studies that compared endoscopic stapes surgery with microscopic stapes surgery. Only studies that met predetermined criteria were selected and assessed for bias and quality. Primary outcomes were postoperative air-bone gap (ABG) and chorda tympani nerve injury. Secondary outcomes were average operating time, tympanic membrane (TM) perforation, and postoperative taste disturbance, pain, and dizziness. We calculated pooled odds ratios (ORs) with 95% confidence intervals (CIs) for dichotomous outcomes and weighted mean difference (WMD) with 95% CI for continuous outcomes. A confidence interval starting above 1.0 was considered as statistically significant. I2 and χ2 tests were used to quantify statistical heterogeneity. We used funnel plots to look for publication bias and performed a sensitivity analysis.Results: Six nonrandomized cohort studies were eligible. The primary outcomes were ABG < 10 dB: OR = 1.80 (95% CI: 0.96 to 3.38), ABG = 11 dB to 20 dB: OR = 1.49 (95% CI: 0.76 to 2.93), ABG > 20 dB: OR = 2.51 (95% CI: 0.77 to 8.22), and chorda tympani injury: OR = 3.51 (95% CI: 1.55 to 7.93). Secondary outcomes were taste: OR = 2.36 (95% CI: 1.01 to 5.51), average operation time: WMD = 0.14 (95% CI: -11.69 to 11.98), TM perforation: OR = 1.70 (95% CI: 0.44 to 6.58); pain: OR = 0.84 (95% CI: 0.36 to 1.96), and dizziness: OR = 2.15 (95% CI: 0.94 to 4.89).Conclusions: Endoscopic stapes surgery is a valid alternative to the microscope.Level Of Evidence: 2a Laryngoscope, 130: 2019-2027, 2020. [ABSTRACT FROM AUTHOR]

Due to its important role in both healthy groups and those with physical, mental and behavioral disorders, impulsivity is a widely researched construct. Among various self-report questionnaires of impulsivity, the Barratt Impulsiveness Scale is arguably the most frequently used measure. Despite its international use, inconsistencies in the suggested factor structure of its latest version, the BIS-11, have been observed repeatedly in different samples. The goal of the present study was therefore to test the factor structure of the BIS-11 in several samples. Exploratory and confirmatory factor analyses were conducted on two representative samples of Hungarian adults (N = 2,457; N = 2,040) and a college sample (N = 765). Analyses did not confirm the original model of the measure in any of the samples. Based on explorative factor analyses, an alternative three-factor model (cognitive impulsivity; behavioral impulsivity; and impatience/restlessness) of the Barratt Impulsiveness Scale is suggested. The pattern of the associations between the three factors and aggression, exercise, smoking, alcohol use, and psychological distress supports the construct validity of this new model. The new measurement model of impulsivity was confirmed in two independent samples. However, it requires further cross-cultural validation to clarify the content of self-reported impulsivity in both clinical and nonclinical samples. [ABSTRACT FROM AUTHOR]

Background: The quadrivalent human papillomavirus (HPV) vaccine has been assumed to give protection against genital warts (GW) as well as cervical cancer. Our main question was whether HPV vaccine has any effects on the prevention of GW reported in randomised controlled clinical trials (RCTs) and time-trend analyses.Methods: This meta-analysis was performed according to the PRISMA guidelines using the PICO format. We searched in three electronic databases (PubMed, Embase, Cochrane Trials), and assessed heterogeneity using the Q-test and I-squared statistics, meta-regression was also performed. Odds ratios (OR) and their confidence intervals (CI) were calculated. The sensitivity was tested by leave-one-out method. We evaluated the presence of publication bias using the funnel plot graph and the Copas selection model. The strength of evidence was assessed using the GRADE approach.Results: Eight RCTs (per-protocol populations) and eight time-trend ecological studies were included in this meta-analysis. A significant reduction (pooled OR = 0.03, 95% CI: 0.01-0.09; I-squared = 53.6%) of GW in young women was recorded in RCTs, and in time-trend analyses both in young women (pooled OR = 0.36, CI 95% = 0.26-0.51; I-squared = 98.2%), and in young men (pooled OR = 0.69, 95% CI = 0.61-0.78; I-squared = 92.7%). In subgroup analysis, a significant reduction of the number of GW events was observed especially in women under 21 years (pooled OR = 0.33, 95% CI = 0.17-0.63). Leave-one-out analysis showed that similar results could be obtained after excluding one study, meta-regression did not show significant difference.Conclusions: Prophylactic, quadrivalent HPV vaccination can prevent GW in healthy women and men, therefore, it should be included in routine immunization programme. [ABSTRACT FROM AUTHOR]

Background: Several studies have suggested that monitoring the depth of anaesthesia might prevent the development of postoperative cognitive decline. We aimed to conduct a meta-analysis to investigate the effects of bispectral index (BIS) monitoring in anaesthesia. Methods: We searched in six major electronic databases. Trials were included if they discussed anaesthesia with and without BIS monitoring or low (<50) and high (≥50) BIS levels and which measured the risk of postoperative delirium (POD) and/or postoperative cognitive dysfunction (POCD). Results: We included fourteen studies in the systematic review, eight of which were eligible for meta-analysis. BIS proved to be protective against POD at 1 day postoperatively in a cohort of 2138 patients (16.1% vs. 22.8% for BIS vs. no BIS groups, respectively; relative risk [RR] 0.71; 95% confidence interval [CI] 0.59 to 0.85, without significant between-study heterogeneity I2 = 0.0%, P = 0.590). The use of BIS was neutral for POCD at 1 week but protective for POCD at 12 weeks (15.8% vs. 18.8% for BIS vs. no BIS groups, respectively; RR = 0.84, CI: 0.66 to 1.08), without significant between-study heterogeneity (I2 = 25.8%, P = 0.260). The neutral association at 1 week proved to be underpowered with trial sequential analysis. In the comparison of low BIS versus high BIS, the incidence of POD at 1 day was similar in the groups. Conclusion: Our findings suggest a protective effect of BIS compared to not using BIS regarding the incidence of POD at 1 day and POCD at 12 weeks. However, limitations of the evidence warrant further investigation to identify those groups of patients by age, comorbid conditions and other individual variables who would benefit the most from the use of BIS monitoring. [ABSTRACT FROM AUTHOR]

It has been generally accepted for long that water molecules are integral parts of layered double hydroxides (LDHs). It is even thought that in the absence of water molecules, there is no LDH structure. It is shown in this contribution that via the solvolysis of Mg- or Ca-alkoxides and Al-alkoxide with methanol or propanol and co-precipitated in methanolic methoxide, water-free LDH-like structures could be constructed. These novel LDH-like materials proved to be more active and selective catalysts in a Knoevenagel condensation than the corresponding 'classical' LDHs. Synthesis, thought to be not possible to prepare, characterization and a catalytic application of water-free LDHs are described. Water molecules are replaced by small alcohol molecules in the interlayer space. [ABSTRACT FROM AUTHOR]

We assessed the cardiovascular safety of long-term direct-acting oral anticoagulant (DOAC) treatment. A search of the medical literature was performed from inception until May 31, 2019. Inclusion criteria were (1) randomized trial that assessed the clinical efficacy and/or safety of 1 or more DOAC, (2) control group including oral anticoagulation and/or antiplatelet and/or placebo treatment, and (3) the incidence of acute coronary syndrome during follow-up was reported. Fixed-effect and random-effects models were applied. The analyzed outcomes were myocardial infarction (MI), major bleeding, and mortality. Twenty-eight randomized clinical trials (196 761 patients) were included. Rivaroxaban was associated with a 21% reduction in the relative risk of MI when compared to placebo (relative risk [RR]: 0.79 [95% credible interval, CrI: 0.65-0.94]) and a 31% reduction (RR: 0.70 [95% CrI: 0.53-0.89]) when compared to dabigatran. Apixaban resulted in 24% (RR: 0.76 [95% CrI: 0.58-0.99]) and vitamin K antagonists anticoagulation resulted in 19% (RR: 0.81 [95% CrI: 0.65-0.98]) risk reduction compared to dabigatran. The computed probability of being the first best choice of treatment was 61.8% for rivaroxaban. Cardiovascular safety shows considerable heterogeneity among oral anticoagulants. Treatment with rivaroxaban is associated with reduced rate of MI. [ABSTRACT FROM AUTHOR]

Background: Endoscopic type I tympanoplasty was originally introduced in the 1990s, and the extensive spread of this practice can be easily observed. The conventional technique performed involves the repair of a tympanic membrane perforation, and is defined as microscopic type I tympanoplasty. Objective of Review: The aim of this study was the comparison of postoperative outcomes of both the endoscopic and the microscopic type I tympanoplasty. Type of Review: We conducted a meta‐analysis in accordance with the Preferred Reporting Items for Systematic Reviews and Meta‐analysis (PRISMA) guidelines. Search Strategy: A systematic literature search was performed in the databases of PubMed, Embase, Cochrane Library, Clarivate Analytics‐Web of Science, ClinicalTrials.gov, World Health Organization Library, and Scopus by inserting, 'myringoplasty OR (tympanoplasty AND perforation)' into the search query. We applied only a 'human' filter. We excluded non‐English studies. Additional records were identified by checking the references of relevant studies. Evaluation Method: Comparative studies were included in our analysis. We calculated the pooled odds ratio (OR) with 95% confidence interval (CI) for dichotomous outcomes and weighted mean difference (WMD) with a 95% CI for continuous outcomes. Additionally, we assessed the risk of bias and estimated the quality of evidence for each outcome. Results: Our systematic search yielded 16 studies (involving 1179 interventions), eligible for analysis. The pooled graft uptake rate (OR: 1.21, CI: 0.82‐1.77; I2 = 0.0%), the postoperative hearing results (WMD = −1.13; 95% CI: −2.72‐0.45; I2 = 78.1%) and the operation time (WMD = −21.11; 95% CI: −42.60‐0.38; I2 = 99.3%), were all comparable amongst the two techniques. In contrast, the endoscopic type I tympanoplasty outperforms when regarding the pooled canaloplasty rate (OR = 7.96; 95% CI: 4.30‐14.76; I2 = 0.0%, P = 1.000) and features an increase in desirable cosmetic results (OR = 19.29; 95% CI: 11.37‐32.73; I2 = 0.0%, P = 0.839), when compared with the microscopic approach. Conclusions: Based on our meta‐analysis, the surgical outcomes of endoscopic type I tympanoplasty in terms of graft uptake rate, postoperative hearing results and operation time were comparable to the microscopic type I tympanoplasty. In regards to cosmetics, an increase in desirable results was achieved in the endoscopic group, particularly the incidence of canaloplasty which proved to be significantly lower. [ABSTRACT FROM AUTHOR]

Ni(II)-containing layered double hydroxides (LDHs) were synthesized with various methods with the intention of placing the Ni(II) ions in different positions in/on the LDH. Ni(II) was introduced as a lattice-modifier into CaAl-, CaFe- and MgAl-LDHs or in the interlayer space in form of a complex anion or as the divalent component of NiAl-LDH or as surface dopant. The materials were structurally characterized by various instrumental methods; however, the final proof of lattice modification was proven by the Suzuki–Miyaura and the Heck coupling reactions. Each as-prepared catalyst was active and selective towards the coupling products with or without various additives. They could be recycled except the surface-doped material, in which intense leaching of the Ni(II) content was observed on reuse. Ni(II)-containing LDHs are active and recyclable catalysts in the Suzuki and Heck coupling reactions—this is the final proof that the Ni(II) ions are constituents of the lattice. [ABSTRACT FROM AUTHOR]

In cases of difficult biliary cannulation, transpancreatic sphincterotomy (TPS) can be an alternative approach of biliary access. However, its success and safety profile have not been studied in detail. A systematic review and meta-analysis were performed to study the overall cannulation success and adverse events of TPS. These outcomes were also compared to other advanced cannulation methods. A systematic literature search was conducted to find all relevant articles containing data on TPS. Successful biliary cannulation and complications rates [post-ERCP pancreatitis (PEP), bleeding, and perforation rates] were compared in the pooled analyses of prospective comparative studies. The overall outcomes were calculated involving all studies on TPS. TPS was superior compared to needle-knife precut papillotomy (NKPP) and the double-guidewire method (DGW) regarding cannulation success (odds ratio [OR] 2.32; 95% confidence interval [CI] 1.37-3.93; and OR 2.72; 95% CI 1.30-5.69, respectively). The rate of PEP did not differ between TPS and NKPP or DGW; however, TPS (only retrospective studies were available for comparison) proved to be worse than needle-knife fistulotomy in this regard (OR 4.62; 95% CI 1.36-15.72). Bleeding and perforation rates were similar among these advanced techniques. There were no data about long-term consequences of TPS. The biliary cannulation rate of TPS is higher than that of the other advanced cannulation techniques, while the safety profile is similar to those. However, no long-term follow-up studies are available on the later consequences of TPS; therefore, such studies are strongly needed for its full evaluation. [ABSTRACT FROM AUTHOR]

Objectives: Functional tooth replacement and bone regeneration are parts of the daily practice in modern dentistry, but well-reproducible and relatively inexpensive experimental models are still missing. We aimed to develop a new small animal model to monitor osseointegration utilizing the combination of multiple evaluation protocols. Material and methods: After cutting the tail between the C4 and C5 vertebrae in Wistar rats, costume made, parallel walled, non-threaded implants were placed into the center of the tail parallel with its longitudinal axis using a surgical guide. Osseointegration of the titanium implants was followed between 4 and 16 weeks after surgery applying axial extraction force, and resonance frequency analysis as functional tests, and histomorphometry and micro-CT as structural evaluations. Results: In functional tests, we observed that both methods are suitable for the detection of the time-dependent increase in osseointegration, but the sensitivity of the pull-out technique (an approximately five times increase with rather low standard error) was much higher than that of the resonance frequency analysis. In structural evaluations, changes in the detected bone implant contact values measured by histomorphometry (yielding 1.5 times increase, with low variations of data) were more reliable than micro-CT based evaluations to screen the developments of contact between bone and implant. Conclusion: Our results provide evidence that the caudal vertebrae osseointegration model is useful for the preclinical evaluation of implant integration into the bone. Clinical relevance: The combination of the biomechanical and structural tests offers a well-reproducible small animal system that can be suitable for studying the integration of various implant materials and surface treatments. [ABSTRACT FROM AUTHOR]

Introduction: Sandblasting is one of the oldest implant surface modifications to enhance osseointegration. Regarding its superiority over machined surface controversies still exist. Our objective was to compare implant failures (IF) and marginal bone level (MBL) changes between sandblasted and machined dental implants by a meta-analysis utilizing the available data. The PROSPERO registration number of the meta-analysis is CRD42018084190. Methods: The systematic search was performed in Cochrane, Embase and Pubmed. Inclusion criteria included participants with neither systemic diseases, nor excessive alcohol consumption, nor heavy smoking. We calculated pooled Risk Ratio (RRs) with confidence intervals of 95% (CIs) for dichotomous outcomes (implant failure) and weighted mean difference (WMD) CIs of 95% for continuous outcomes (marginal bone level change). We applied the random effect model with DerSimonian-Laird estimation. I2 and chi2 tests were used to quantify statistical heterogeneity and gain probability-values, respectively. Results: Literature search revealed 130 records without duplicates. Out of these, seven studies met the inclusion criteria and all were included in data synthesis, involving 362 sand-blasted and 360 machined implants. The results indicate that there is an 80% (RR = 0.2 95% CI:0.06–0.67; I2 = 0.0% p = 0.986) lower among sandblasted compared to machined implants after one year of use and 74% (RR = 0.26 95% CI:0.09–0.74; I2 = 0.0% p = 0.968) five years of use, respectively. In contrast, there is no significant difference in MBL (WMD:-0.10mm, 95% CI:-0.20, 0.01; p>0.05; I2 = 0.0%, p = 0.560 and WMD:-0.01mm, 95% CI:-0.12, 0.09; p>0.05; I2 = 26.2%, p = 0.258) between the two implant surfaces after one and five years of use. Conclusions: This meta-analysis reveals that sandblasting is superior over machined surface in implant failure but not in marginal bone level in healthy subjects. It also points out the need for further randomized clinical trials with large sample size for objective determination of the clinical benefits of certain implant surface modifications. [ABSTRACT FROM AUTHOR]

Aims: Our aim was to summarize the available literature on the effect of short- versus long-course antibiotic therapy on acute cholangitis.Methods: A systematic review was performed according to the PRISMA Statement. We searched three databases for papers discussing the length of ABT in acute cholangitis. Long and short therapy groups were defined based on the most recent guideline available at the time of publication of the articles. Primary outcomes were the rate of recurrent cholangitis and mortality; secondary outcomes included length of hospitalization and the duration of fever after ERCP. Data were extracted on these outcomes and on general characteristics. A narrative synthesis was then provided based on collected data.Results: Out of 692 articles produced by our search, four met our inclusion and exclusion criteria. These contained 205 acute cholangitis patients, with 137 and 68 patients receiving short and long antibiotic therapy, respectively. No significant difference was observed in any of the studies on the outcomes of mortality and duration of fever after ERCP between the two groups. One out of four studies found the rate of recurrent cholangitis to be significantly lower in the short antibiotic therapy group (0.0% vs. 13.3%, p = 0.036). Length of hospitalization was only compared in the same retrospective article, where it was found to be significantly shorter in the short-term antibiotic therapy group (with a median of 14 vs. 17.5 days, p < 0.001).Conclusions: Our review suggests short-course antibiotic therapy is non-inferior to long-course treatment; however, several limitations underline the need for well-designed randomized trials. [ABSTRACT FROM AUTHOR]

Periodontal ligament stem cells (PDLSCs) possess extensive regeneration potential. However, their therapeutic application demands a scaffold with appropriate properties. HydroMatrix (HydM) is a novel injectable peptide nanofiber hydrogel developed recently for cell culture. Our aim was to test whether HydM would be a suitable scaffold for proliferation and osteogenic differentiation of PDLSCs. PDLSCs were seeded on noncoated or HydM-coated surfaces. Both real-time impedance analysis and cell viability assay documented cell growth on HydM. PDLSCs showed healthy, fibroblast-like morphology on the hydrogel. After a 3-week-long culture in osteogenic medium, mineralization was much more intense in HydM cultures compared to control. Alkaline phosphatase activity of the cells grown on the gels reached the non-coated control levels. Our data provided evidence that PDLSCs can adhere, survive, migrate, and proliferate on HydM and this gel also supports their osteogenic differentiation. We first applied impedimetry for dental stem cells cultured on a scaffold. HydM is ideal for in vitro studies of PDLSCs. It may also serve not only as a reference material but also in the future as a promising biocompatible scaffold for preclinical studies. [ABSTRACT FROM AUTHOR]

Optimum conditions were searched for the synthesis of Cu(II)Cr(III)-L(ayered)D(ouble)H(ydroxide), then the intercalation and catalytic properties were studied. For the optimization, the molar ratio of the metal ions, pH, temperature and ageing time were systematically varied. Applying this LDH as the host, the anionic form of l-proline was intercalated into the interlayer space with the direct anion-exchange method. For the structural characterization of the pristine and the intercalated products, powder X-ray diffractometry, IR spectroscopy, scanning and transmission electron microscopies as well as thermal methods were used. The catalytic properties were investigated in the oxidation of allylic alcohol. The reaction parameters such as the solvent, oxidant and the catalysts treatment were varied. [ABSTRACT FROM AUTHOR]

Bone morphogenetic protein-2 (BMP-2), is a potential factor to enhance osseointegration of dental implants. However, the appropriate cellular system to investigate the osteogenic effect of BMP-2 in vitro in a standardized manner still needs to be defined. The aim of this study was to examine the effect of BMP-2 on the cell proliferation and osteogenic differentiation of human osteogenic progenitors of various origins: dental pulp stem cells (DPSC), human osteosarcoma cell line (Saos-2) and human embryonic palatal mesenchymal cell line (HEPM). For induction of osteogenic differentiation, cell culture medium was supplemented with BMP-2 homodimer alone or in combination with conventionally used differentiation inducing agents. Differentiation was monitored for 6-18 days. To assess differentiation, proliferation rate, alkaline phosphatase activity, calcium deposition and the expression level of osteogenic differentiation marker genes (Runx2, BMP-2) were measured. BMP-2 inhibited cell proliferation in a concentration and time-dependent manner. In a concentration which caused maximal cell proliferation, BMP-2 did not induce osteogenic differentiation in any of the tested systems. However, it had a synergistic effect with the osteoinductive medium in both DPSC and Saos-2, but not in HEPM cells. We also found that the differentiation process was faster in Saos-2 than in DPSCs. Osteogenic differentiation could not be induced in the osteoblast progenitor HEPM cells. Our data suggest that in a concentration that inhibits proliferation the differentiation inducing effect of BMP-2 is evident only in the presence of permissive osteoinductive components. β-glycerophosphate, was identified interacting with BMP-2 in a synergistic manner. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of a silver-containing hybrid material is reported as a novel heterogeneous noble metal catalyst. In order to eliminate the need for traditional immobilization techniques, and to create a solid material with structurally-bound silver catalytic centers, the layered structure of a naturally occurring mineral served as the basis of the initial catalyst design. The novel material was prepared by means of the urea-mediated homogeneous precipitation of the corresponding metal nitrates, and was fully characterized by means of diverse instrumental techniques (X-ray diffractometry, Raman, IR, UV-Vis, EPR, X-ray photoelectron spectroscopies, thermal methods as well as atomic force, scanning and transmission electron microscopies). The as-prepared material exhibited outstanding activity in silver-catalyzed C≡C bond activation to yield organic nitriles directly from terminal alkynes with less environmental concerns as compared to the classical synthesis methods. The effects of the reaction time, the temperature, as well as the role of various solvents, nitrogen sources and additives were carefully scrutinized in order to achieve high-yielding and selective nitrile formation. The heterogeneous nature of the reaction was verified and the solid catalyst was recycled and reused numerous times without loss of its activity or degradation of its structure, thereby offering a sustainable synthetic methodology. [ABSTRACT FROM AUTHOR]

We have recently developed a novel in vitro model using HAT-7 rat ameloblast cells to functionally study epithelial ion transport during amelogenesis. Our present aims were to identify key transporters of bicarbonate in HAT-7 cells and also to examine the effects of fluoride exposure on vectorial bicarbonate transport, cell viability, and the development of transepithelial resistance. To obtain monolayers, the HAT-7 cells were cultured on Transwell permeable filters. We monitored transepithelial resistance (TER) as an indicator of tight junction formation and polarization. We evaluated intracellular pH changes by microfluorometry using the fluorescent indicator BCECF. Activities of ion transporters were tested by withdrawal of various ions from the bathing medium, by using transporter specific inhibitors, and by activation of transporters with forskolin and ATP. Cell survival was estimated by alamarBlue assay. Changes in gene expression were monitored by qPCR. We identified the activity of several ion transporters, NBCe1, NHE1, NKCC1, and AE2, which are involved in intracellular pH regulation and vectorial bicarbonate and chloride transport. Bicarbonate secretion by HAT-7 cells was not affected by acute fluoride exposure over a wide range of concentrations. However, tight-junction formation was inhibited by 1mM fluoride, a concentration which did not substantially reduce cell viability, suggesting an effect of fluoride on paracellular permeability and tight-junction formation. Cell viability was only reduced by prolonged exposure to fluoride concentrations greater than 1mM. In conclusion, cultured HAT-7 cells are functionally polarized and are able to transport bicarbonate ions fromthe basolateral to the apical fluid spaces. Exposure to 1mM fluoride has little effect on bicarbonate secretion or cell viability but delays tight-junction formation, suggesting a novel mechanism that may contribute to dental fluorosis. [ABSTRACT FROM AUTHOR]

Host-guest composite materials were prepared applying the anionic forms of Ni(II)-amino acid ( l-histidine, l-cysteine, and l-tyrosine) as the guests and CaAl-layered double hydroxide (CaAl-LDH) as the host. The syntheses were performed either by introducing the amino acid anions first and then constructing the metal ion-amino acid complexes or intercalating the pre-prepared complexes in anionic forms. The pristine as well as the composite LDH samples were structurally characterized by X-ray diffractometry, mid IR spectroscopy and scanning electron microscopy. The structural features of the interlayer complexes were studied by UV-Vis, inductively coupled plasma optical emission, mid and far IR and X-ray absorption spectroscopies as well as energy-dispersed X-ray analysis. On the basis of the acquired data, structural models were constructed. The composites were applied as catalysts in the liquid-phase oxidation of cyclohexene applying peracetic acid and the in situ formed iodosyl benzene as oxidants. Using peracetic acid afforded epoxide, while applying iodosyl benzene provided cis diol as the major or exclusive oxidation product. The catalysts displayed good recycling properties. [ABSTRACT FROM AUTHOR]

Mn(II)-containing layered double hydroxides were prepared having the Mn(II) ions in various positions (i) on the layers as dopants, (ii) in the layers as their constituents and (iii) among the layers in the form of intercalated Mn(II) amino acid complexes. The substances were characterized by a range of instrumental methods (XRD, SEM, SEM-EDX) to indicate the positions of the Mn(II) ions. The catalytic activities of the composites were studied in the Ullmann-type etherification reaction. All materials promoted the reaction actively. However, only those having the Mn(II) ions in the structure of the LDH samples, the latter two, proved to be recyclable, i.e. they were real catalysts; the activity of the one prepared by doping deteriorated rapidly on reuse. [ABSTRACT FROM AUTHOR]

Boron-containing CaAl-layered double hydroxides (LDHs) were prepared by milling, as well as the dehydration-rehydration and the anion-exchange methods. The substances obtained were structurally characterized by powder X-ray diffraction measurements, scanning electron microscopy and infrared spectroscopy. Various borate species could be introduced among the layers and/or the outer surface of the CaAl-LDH. The materials were tested as catalysts in the Beckmann rearrangement of cyclohexanone oxime to ε-caprolactam in the liquid phase, at 373 K. Two of them, the samples prepared by dehydration-rehydration and anion exchange, proved to be active, selective and recyclable catalysts, while the one made by the mechanochemical method was practically inactive. The catalytic activity was tied to intercalated and/or surface-bonded triborate and tetraborate species. [ABSTRACT FROM AUTHOR]