The Use of Mineral Trioxide Aggregate in The Treatment of Horizontal Root Fractures: A Case Presentation and Literature Update

Root fracture is a rarely seen traumatic injury in permanent dentition. It has a prevalence of 0.5-7 %. Tooth survival is significantly affected by the type of healing and the location of the root fracture. Additionally, the patient’s age, stage of root development, mobility and dislocation of the coronal fragment, and diastasis between fragments following this kind of injury are among the important factors. In this case presentation, the management with MTA plug and 6-year follow-up of a horizontal root fracture was reported. A literature update regarding the use of MTA in the management of horizontal root fractures was also added to discuss its merit

Activin Receptor Type 2 A (ACVR2A)-dependent Proteomic and Glycomic Alterations in a Microsatellite Unstable (MSI) Colorectal Cancer Cell Line Model System

DNA mismatch repair-deficient colorectal tumors exhibit a high-frequency of microsatellite instability (MSI-H) and accumulate somatic frameshift mutations in genes harboring repetitive DNA sequences. Biallelic frameshift mutations in the A8 coding repeat of the activin receptor type 2 A (ACVR2A or ACVR2) gene occur at high frequency in these tumors thereby abrogating normal receptor and signaling function. Nevertheless, it is not clear if protein deficiency is modifying the glycosylation pattern as well as the whole proteomic constellation of cells, since it has been shown that proteomic and glycomic alterations have emerging significance in cancer cells. Here, we compensated the loss of function by reconstitution of ACVR2 into a MSI-H colon cancer cell line and analyzed its impact on the protein pattern of these cells. As a model system we used the MSI colorectal cancer cell line HCT116-AWE that enables doxycycline-inducible expression of target genes. Applying retroviral genomic targeting and recombination-mediated cassette exchange (RMCE) technology we have generated stable clones that allow dox-regulated expression of a single copy ACVR2 transgene. Fragment analysis, determination of the transgene transcript level, dox-inducible expression of wildtype ACVR2 protein and functional analysis by ligand-stimulated activation of signal transduction and expression of specific target genes confirmed successful gene reconstitution. Upon induction of receptor expression, glyco-gene chip expression analysis of ACVR2-induced versus -uninduced cells revealed ACVR2-dependent upregulation of the glycosyltransferase LNFG, an important regulator of Notch signaling. Moreover, metabolic labeling experiments showed a significant decrease in fucose incorporation and a modest increase in mannosamine uptake, indicating significant glycan alterations of newly synthesized proteins due to ACVR2 re-expression. By applying a Click-it chemistry approach and subsequent mass spectrometry analysis a list of proteins, differentially expressed between ACVR2-deficient and -proficient cells, was identified. These results suggest that ACVR2 signaling can affect glycomic and proteomic modifications that might cause alterations in many cellular processes like growth suppression, cell death, cell adhesion and communication properties or invasion and metastasis of these MSI tumor cells. This study is of major relevance because it may define and provide a novel source of MSI tumor-specific carbohydrate epitope changes in cell surface levels, thereby initiating analysis of glycan function related to MSI. At the same time new tumor markers could be established, which are not only monitors for diagnosis or therapy, but also represent the biological characteristics of cancer cells

Turkish Paediatric Dentists’ Knowledge, Experiences and Attitudes Regarding Child Physical Abuse

Objectives Numerous studies have shown that the education of health professionals is essential to effectively respond to child abuse. The present study aimed to evaluate Turkish paediatric dentists\u27 knowledge, experiences and attitudes regarding child physical abuse. Materials and methods An electronic questionnaire was e‐mailed to 518 paediatric dentists. Participants’ knowledge of diagnostic indicators of child physical abuse, and their past experiences, attitudes and self‐assessment of educational needs were evaluated. Results The response rate was 40.9% (n = 212). Participants who completed their undergraduate education before 1997 received significantly less education on child physical abuse than participants who completed their education more recently (P \u3c 0.001). Although statistically insignificant, participants who completed their doctorate/specialty training after 2012 received increased education on child physical abuse (P = 0.06). Of the participants, 43.9% suspected physical abuse; however, only 12.7% reported it. ‘I did not know where and how to report’ was the most common reason for not reporting physical abuse. The rate of suspicion was higher among dentists from state hospitals or oral health centres (P \u3c 0.05). Of the participants, 70.3% did not know about the legal sanctions for delay in or not reporting suspected cases. Only 15.6% assessed themselves as competent to diagnose and report physical abuse. Almost all of them acknowledged their need for more education on this topic. Conclusion Turkish paediatric dentists’ educational needs for diagnosing and reporting of child physical abuse cases should be met

Detection of silver nanoparticles inside leaf of European beech (Fagus sylvatica L.)

In a greenhouse experiment, silver nanoparticles (Ag-NPs) were applied on European beech (Fagus sylvatica L.) leaves using the droplet application method. Scanning electron microscopy (SEM) analyses showed that after 24 h silver nanoparticles were mostly present in aggregates or as single particles on the surface of the leaf, surrounding or covering the stomata. Analyses of cross sections of the leaf revealed that some silver nanoparticles were adhering to the cell walls of the mesophyll and palisade cells, most likely after penetration into the leaf through the stomata as particles and not as Ag ions. Our preliminary results showed evidence of foliar uptake of silver nanoparticles in European beech. This opens new insights on the ability of trees to take up solid nanosized particles, eventually contained in raindrops, through their leaves, and potentially transport them to other parts of the tree. This study would be helpful for investigating the role of trees in atmospheric ultrafine particle mitigation

Chemical elements recorded by Quercus mongolica Fisch. ex Ledeb. Tree rings reveal trends of pollution history in Harbin, China

Rapid industrialization has led to a dramatic increase in air pollution. In China, the factors driving the abundance and composition of smog, particularly fine particulate matter, remain poorly understood, and short-term air pollution data are available from few air quality monitoring networks. Using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), chemical elements (Mg, Al, Si, S, K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Tl, Pb, Bi) were analyzed in Quercus mongolica Fisch. ex Ledeb. tree rings from Harbin, China, in latewood at 5-year resolution over the period 1965–2020. The temporal trend of some elements was influenced by physiological factors, by environmental factors such as pollution, or influenced by both. Mg, K, Zn, Cu, Ni, Pb, As, Sr and Tl showed changes in pollution levels over time. The signal of K, Zn, Ni, Cu and Pb in trees from Harbin statistically did not differ from those at the control site after the 2000s. Our analysis confirmed the success of the undertaken emission reduction measures, which lead to an improvement in China’s urban air quality after 2010. However, As increased from 2000 to 2020 in Harbin which is consistent with rising As concentrations in China. Our study proved that dendrochemistry is a reliable tool to monitor the long-term history of pollution and to contribute to extending instrumental records of pollution back in time

Detection of silver nanoparticles inside leaf of European beech (Fagus sylvatica L.)

In a greenhouse experiment, silver nanoparticles (Ag-NPs) were applied on European beech (Fagus sylvatica L.) leaves using the droplet application method. Scanning electron microscopy (SEM) analyses showed that after 24 h silver nanoparticles were mostly present in aggregates or as single particles on the surface of the leaf, surrounding or covering the stomata. Analyses of cross sections of the leaf revealed that some silver nanoparticles were adhering to the cell walls of the mesophyll and palisade cells, most likely after penetration into the leaf through the stomata as particles and not as Ag ions. Our preliminary results showed evidence of foliar uptake of silver nanoparticles in European beech. This opens new insights on the ability of trees to take up solid nanosized particles, eventually contained in raindrops, through their leaves, and potentially transport them to other parts of the tree. This study would be helpful for investigating the role of trees in atmospheric ultrafine particle mitigation

Charge-carrier behavior in Ba-, Sr- and Yb-filled CoSb3_3: NMR and transport studies

We report $^{59}$Co NMR and transport measurements on $n$-type filled skutterudites Ba$_x$Yb$_y$Co$_4$Sb$_{12}$ and $A$$_x$Co$_4$Sb$_{12}$ ($A$= Ba, Sr), promising thermoelectric materials. The results demonstrate consistently that a shallow defect level near the conduction band minimum dominates the electronic behavior, in contrast to the behavior of unfilled CoSb$_3$. To analyze the results, we modeled the defect as having a single peak in the density of states, occupied at low temperatures due to donated charges from filler atoms. We fitted the NMR shifts and spin-lattice relaxation rates allowing for arbitrary carrier densities and degeneracies. The results provide a consistent picture for the Hall data, explaining the temperature dependence of the carrier concentration. Furthermore, without adjusting model parameters, we calculated Seebeck coefficient curves, which also provide good consistency. In agreement with recently reported computational results, it appears that composite native defects induced by the presence of filler atoms can explain this behavior. These results provide a better understanding of the balance of charge carriers, of crucial importance for designing improved thermoelectric materials.Comment: 9 pages, 8 figure

Thermoelectric enhancement in PbTe with K, Na co-doping from tuning the interaction of the light and heavy hole valence bands

The effect of K and K-Na substitution for Pb atoms in the rock salt lattice of PbTe was investigated to test a hypothesis for development of resonant states in the valence band that may enhance the thermoelectric power. We combined high temperature Hall-effect, electrical conductivity and thermal conductivity measurements to show that K-Na co-doping do not form resonance states but2 can control the energy difference of the maxima of the two primary valence sub-bands in PbTe. This leads to an enhanced interband interaction with rising temperature and a significant rise in the thermoelectric figure of merit of p-type PbTe. The experimental data can be explained by a combination of a single and two-band model for the valence band of PbTe depending on hole density that varies in the range of 1-15 x 10^19 cm^-3.Comment: 8 figure

First evidence of nanoparticle uptake through leaves and roots in beech (Fagus sylvatica L.) and pine (Pinus sylvestris L.)

Trees have been used for phytoremediation and as biomonitors of air pollution. However, the mechanisms by which trees mitigate nanoparticle pollution in the environment are still unclear. We investigated whether two important tree species, European beech (Fagus sylvatica L.) and Scots pine (Pinus sylvestris L.), are able to take up and transport differently charged gold nanoparticles (Au-NPs) into their stem by comparing leaf-to-root and root-to-leaf pathways. Au-NPs were taken up by roots and leaves, and a small fraction was transported to the stem in both species. Au-NPs were transported from leaves to roots but not vice versa. Leaf Au uptake was higher in beech than in pine, probably because of the higher stomatal density and wood characteristics of beech. Confocal (3D) analysis confirmed the presence of Au-NPs in trichomes and leaf blade, about 20–30 μm below the leaf surface in beech. Most Au-NPs likely penetrated into the stomatal openings through diffusion of Au-NPs as suggested by the 3D XRF scanning analysis. However, trichomes were probably involved in the uptake and internal immobilization of NPs, besides their ability to retain them on the leaf surface. The surface charge of Au-NPs may have played a role in their adhesion and uptake, but not in their transport to different tree compartments. Stomatal conductance did not influence the uptake of Au-NPs. This is the first study that shows nanoparticle uptake and transport in beech and pine, contributing to a better understanding of the interactions of NPs with different tree species

Promising bulk nanostructured Cu₂Se thermoelectrics via high throughput and rapid chemical synthesis

A facile and high yield synthesis route was developed for the fabrication of bulk nanostructured copper selenide (Cu2Se) with high thermoelectric efficiency. Starting from readily available precursor materials and by means of rapid and energy-efficient microwave-assisted thermolysis, nanopowders of Cu2Se were synthesized. Powder samples and compacted pellets have been characterized in detail for their structural, microstructural and transport properties. alpha to beta phase transition of Cu2Se was confirmed using temperature dependent X-ray powder diffraction and differential scanning calorimetry analyses. Scanning electron microscopy analysis reveals the presence of secondary globular nanostructures in the order of 200 nm consisting of <50 nm primary particles. High resolution transmission electron microscopy analysis confirmed the highly crystalline nature of the primary particles with irregular truncated morphology. Through a detailed investigation of different parameters in the compaction process, such as applied load, heating rate, and cooling profiles, pellets with preserved nanostructured grains were obtained. An applied load during the controlled cooling profile was demonstrated to have a big impact on the final thermoelectric efficiency of the consolidated pellets. A very high thermoelectric figure of merit (ZT) above 2 was obtained at 900 K for SPS-compacted Cu2Se nanopowders in the absence of the applied load during the controlled cooling step. The obtained ZT exceeds the state of the art in the temperature ranges above phase transition, approaching up to 25% improvement at 900 K. The results demonstrate the prominent improvement in ZT attributed both to the low thermal conductivity, as low as 0.38 W m(-1) K-1 at 900 K, and the enhancement in the power factor of nanostructured Cu2Se. The proposed synthesis scheme as well as the consolidation could lead to reliable production of large scale thermoelectric nanopowders for niche applications