Background: Teeth discoloration is one of the adverse effects of orthodontic treatment which causes aesthetic issues that effect on a person’s appearance. The management of teeth discoloration can be ...done with bleaching because it is easier to perform, faster, more effective, and more conservative than other treatments such as crowns and veneers. There are two types of bleaching techniques supervised by dentists: home bleaching and in-office bleaching. In-office bleaching is one of the most conservative and non-invasive treatment options to restore the aesthetics of discolored teeth. Purpose: This case report observes management of tooth discoloration after orthodontic treatment with in office bleaching using hydrogen peroxide 40%. Case 1: A 24-year-old woman came to Universitas Hasanuddin Dental and Oral Hospital with complaints of yellowish upper and lower teeth after removal of her fixed orthodontic appliance. Case 2: A 24 years old woman came to Universitas Hasanuddin Dental and Oral Hospital with complaints of upper and lower front teeth appearing yellowish in color, noticed from 2 years ago and had undergone orthodontic treatment for four years. Case Management: From clinical examination, both patients’ teeth have no history of caries, sensitive tooth and gingival recession. The Teeth were sensitive to vitality test. The discoloration was treated with external bleaching using 40% hydrogen peroxide. Conclusion: External Bleaching using 40% hydrogen peroxide have results in significant discoloration without changing the shape and arrangement of the patient’s teeth
Results on beam tests of 3D silicon pixel sensors aimed at the ATLAS Insertable-B-Layer and High Luminosity LHC (HL-LHC)) upgrades are presented. Measurements include charge collection, tracking ...efficiency and charge sharing between pixel cells, as a function of track incident angle, and were performed with and without a 1.6 T magnetic field oriented as the ATLAS Inner Detector solenoid field. Sensors were bump bonded to the front-end chip currently used in the ATLAS pixel detector. Full 3D sensors, with electrodes penetrating through the entire wafer thickness and active edge, and double-sided 3D sensors with partially overlapping bias and read-out electrodes were tested and showed comparable performance.
Aim: Atherosclerosis is responsible for high morbidity and mortality rates around the world. Local arterial oxidative stress is involved in all phases of atherosclerosis development. Mitochondria is ...a relevant source of the oxidants, particularly under certain risky conditions, such as hypercholesterolemia. The aim of this study was to test whether lowering the production of mitochondrial oxidants by induction of a mild uncoupling can reduce atherosclerosis in hypercholesterolemic LDL receptor knockout mice. Methods: The mice were chronically treated with very low doses of DNP (2,4-dinitrophenol) and metabolic, inflammatory and redox state markers and atherosclerotic lesion sizes were determined.Results: The DNP treatment did not change the classical atherosclerotic risk markers, such as plasma lipids, glucose homeostasis, and fat mass, as well as systemic inflammatory markers. However, the DNP treatment diminished the production of mitochondrial oxidants, systemic and tissue oxidative damage markers, peritoneal macrophages and aortic rings oxidants generation. Most importantly, development of spontaneous and diet-induced atherosclerosis (lipid and macrophage content) were significantly decreased in the DNP-treated mice. In vitro, DNP treated peritoneal macrophages showed decreased H2O2 production, increased anti-inflammatory cytokines gene expression and secretion, increased phagocytic activity, and decreased LDL-cholesterol uptake.Conclusions: These findings are a proof of concept that activation of mild mitochondrial uncoupling is sufficient to delay the development of atherosclerosis under the conditions of hypercholesterolemia and oxidative stress. These results promote future approaches targeting mitochondria for the prevention or treatment of atherosclerosis.
Silica nanoparticles (SiO2NPs) from renewable sources can be used in very different materials, such as paints, membranes for fuel cells, Li-ion batteries, adsorbents, catalysts, and so on. Brazil is ...the world’s largest producer of sugarcane and generates huge amounts of sugarcane waste ash (SWA), which is a Si-rich source. This study investigates a method to produce highly pure SiO2NPs from SWA. The SiO2NPs were characterized by inductively coupled plasma optical emission spectroscopy, scanning and transmission electron microscopy (TEM), X-ray diffraction analyses, specific surface area and pore distribution, UV and Fourier transform infrared spectroscopy, and thermogravimetric analyses and applied as an adsorbent material in the removal of acid orange 8 (AO8) dye from aqueous solution. The SiO2 content was 88.68 and 99.08 wt % for SWA and SiO2NPs, respectively. TEM images of SWA and SiO2NPs exhibit drastic alterations of the material size ranging from several micrometers to less than 20 nm. The SiO2NPs showed a specific surface area of 131 m2 g–1 and adsorption capacity of around 230 mg g–1 for acid orange 8 dye. Furthermore, the recycling of the SiO2NPs adsorbent after AO8 adsorption was very satisfactory, with reuse for up to five cycles being possible. The results indicate that it was possible to obtain highly pure silica in a nanosize from the waste material and produce an adsorbent with high adsorption capacity and the possibility of reuse.
The mechanisms by which a high fat diet (HFD) promotes non-alcoholic fatty liver disease (NAFLD) appear to involve liver mitochondrial dysfunctions and redox imbalance. We hypothesized that a HFD ...would increase mitochondrial reliance on NAD(P)-transhydrogenase (NNT) as the source of NADPH for antioxidant systems that counteract NAFLD development. Therefore, we studied HFD-induced liver mitochondrial dysfunctions and NAFLD in C57Unib.B6 congenic mice with (Nnt+/+) or without (Nnt-/-) NNT activity; the spontaneously mutated allele (Nnt-/-) was inherited from the C57BL/6J mouse substrain. After 20 weeks on a HFD, Nnt-/- mice exhibited a higher prevalence of steatohepatitis and content of liver triglycerides compared to Nnt+/+ mice on an identical diet. Under a HFD, the aggravated NAFLD phenotype in the Nnt-/- mice was accompanied by an increased H2O2 release rate from mitochondria, decreased aconitase activity (a redox-sensitive mitochondrial enzyme) and higher susceptibility to Ca2+-induced mitochondrial permeability transition. In addition, HFD led to the phosphorylation (inhibition) of pyruvate dehydrogenase (PDH) and markedly reduced the ability of liver mitochondria to remove peroxide in Nnt-/- mice. Bypass or pharmacological reactivation of PDH by dichloroacetate restored the peroxide removal capability of mitochondria from Nnt-/- mice on a HFD. Noteworthy, compared to mice that were chow-fed, the HFD did not impair peroxide removal nor elicit redox imbalance in mitochondria from Nnt+/+ mice. Therefore, HFD interacted with Nnt mutation to generate PDH inhibition and further suppression of peroxide removal. We conclude that NNT plays a critical role in counteracting mitochondrial redox imbalance, PDH inhibition and advancement of NAFLD in mice fed a HFD. The present study provide seminal experimental evidence that redox imbalance in liver mitochondria potentiates the progression from simple steatosis to steatohepatitis following a HFD.
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•The Nnt genotype modifies the effects of high fat diet (HFD) on mouse liver.•The Nnt mutation from the C57BL/6J mouse aggravates HFD-induced fatty liver disease.•Functional Nnt preserves pyruvate metabolism and mitochondrial oxidative balance.•On HFD, mutated Nnt leads to the progression from simple steatosis to steatohepatitis.•The use of mice models carrying mutated Nnt in research must not be overlooked.
Even with all the biological problems associated with bisphenol-A (BPA), this chemical is still being widely used, especially in thermal paper receipts. In this study, renewable mesoporous silica ...nanoparticles (MSN), obtained from sugarcane ash, functionalized with hexadecyltrimethylammonium (CTAB) were applied as an adsorbent in the removal of BPA from the aqueous solution. The versatility of this material and its BPA adsorption capacity were tested at different pH values, being practically constant at pH between 4 and 9, with a slight increase in pH 10 and a greater increase in pH 11. The removal time evaluation indicates a very fast adsorption process, removing almost 90% of BPA in the first 20 min of contact. The kinetic model indicates a monolayer formation of BPA molecules on the MSN-CTAB surface. The maximum adsorption capacity (
Q
max
) was 155.78 mg g
−1
, one of the highest found in literature, and the highest for material from a renewable source.
Utilization of renewable mesoporous silica nanoparticles, from sugarcane ash, as an adsorbent for removal of an endocrine disruptive compound, bisphenol-A.
The prevalence of hepatitis C virus (HCV) and the acquired immunodeficiency virus (HIV) is much higher in prisons than in community settings. Some explanatory factors for this burden include putative ...aspects of the prison environment, such as unprotected sexual relations and sexual violence, use of injectable drugs and syringe sharing. Nonetheless, efforts in better understanding the dynamics of both HCV and HIV are scarce in developing countries such as Brazil, which poses a risk not only to the inmates but to the community as well. In this investigation, we sought to determine the seroprevalence and sociodemographic and behavioral risk factors associated with HIV and anti-HCV antibodies among men detained at high-security institutions. This is an epidemiological, proportionally stratified observational study including 1,132 inmates aged 18 to 79 years-old (M.sub.age = 32.58±10.18) from eleven high-security prisons located in the State of Paraná, Brazil. We found that HIV and anti-HCV prevalence were 1.6% (95% CI: 1.0-2.5) and 2.7% (95% CI: 1.0-2.5), respectively. Risk factors associated with HIV included not receiving intimate visits (OR = 8.80, 95% CI: 1.15-66.88), already having another sexually transmitted infection (OR = 3.89, 95% CI: 1.47-10.29), and reporting attendance in HIV preventive campaigns (OR = 4.24, 95% CI: 1.58-11.36). Moreover, anti-HCV seroprevalence was associated with higher age (OR = 4.03, 95% CI: 1.61-10.07), criminal recidivism (OR = 2.58, 95% CI 1.02-6.52), and the use of injectable drugs (OR = 7.32, 95% CI 3.36-15.92). Although prisons might increase the risk for acquiring and transmitting HIV and HCV, the adoption of permanent epidemiological surveillance programs could help reducing the circulation of viruses, involving strategies focusing on screening, treating, and preventing infections to assure proper prisoner health. Moreover, these policies need to take place inside and outside the prison environment to offer continued assistance to former prisoners once they leave the institution.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Current asphalt binder production has significantly changed since the Strategic Highway Research Program Superpave days as a result of a number of economic, technical, and environmental reasons. ...Petroleum sources and product demands have changed considerably, and as a result, refining technologies have had to adapt as well as asphalt suppliers. Blending of crude oils and refining streams as well as additive treatment at various stages of extraction or refining by the addition of additives is now common practice and is continuing to grow. Considering asphalt as a straight-run vacuum residue from a single crude oil is now the exception. Most of the aforementioned changes can enhance binder properties when they are designed and controlled well. However, some of these changes trigger concerns about the quality and consistency of the delivered asphalt binder, especially as current specifications appear insufficient to ensure satisfactory field performance of the end products. The Asphalt Industry Research Consortium (AIRC) was launched by the Western Research Institute in 2015 to help industrial partners evolve with the changing asphalt binder landscape. This study provides select insights produced from the eight partners who helped launch the AIRC program to perform chemomechanical characterization of 52 asphalt binders from around the world. In this study, multiple techniques were instrumental to diagnose various refining processes, compositions, and binder modifiers. These techniques include rheology–Black space analysis, saturates, aromatics, resins–asphaltene Determinator (SAR-ADTM), Fourier transform infrared spectroscopy, Waxphaltene Determinator (WD), differential scanning calorimetry, and gel permeation chromatography/size-exclusion chromatography. This paper presents the potential of these techniques for diagnosing air-blown, high-asphaltene-content, high-wax-content, visbroken, styrene–butadiene–styrene-modified, ethylene–vinyl acetate-modified, and paraffin-modified binders and blends. The authors also believe that well-formulated and compatible blends of any of these production or modification methods may perform well in the field. Links are made between chemically based techniques and understanding how these are manifested in the physical/mechanical properties of the materials.
Martensitic stainless steel is a potential material class for selection in some tribological systems, particularly those subjected to wear by hard particles and corrosion. To improve its mechanical ...resistance, without loss of corrosion performance, surface treatments such as low-temperature nitriding and carburizing have been systematically employed. In this context, this paper studied martensitic stainless steel samples subjected to different plasma-assisted treatments, in the case the plasma nitriding and plasma carburizing. The treatments were carried out at temperatures of 300, 350 or 400°C, for different times, aiming to compare the scratch resistance of the treated surfaces. Specimens were initially characterized using X-Ray diffractometry, micro and nanohardness measurements. Scratch resistance was performed using the constant load mode for two levels, 8 and 15N. All worn tracks were evaluated using optical interferometry, to get information about the widths and depths of track profiles. Worn surfaces were analysed using scanning electron microscope, revealing tensile cracks on the surface of nitrided samples. The friction coefficient and the wear resistance were analysed and related to the geometry of scratches, which was associated to the micro-mechanism of wear. Despite the high hardness and low friction coefficient achieved using nitriding treatment, the global performance of carburized samples could be considered as more suitable, because the carburized case significantly minimized the cracks formation. Therefore, plasma carburized martensitic stainless steel can be considered an adequate combination for corrosion environments subjected to wear.
•A stainless steel is subject to different treatments of nitriding and carburizing.•High hardness and low friction coefficient were achieved using nitriding treatment.•Carburizing treatment minimizes the formation of tensile cracks.•Carburized stainless steel is a good option for environments subjected to wear.
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