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The detection of thrombin by using CdS nanocrystals (CdS NCs), gold nanoparticles (AuNPs) and luminol is investigated in this work. Thrombin is detected by three methods. One is called the quenching method. It is based on the quenching effect of AuNPs on the yellow fluorescence of CdS NCs (with excitation/emission wavelengths of 355/550 nm) when placed adjacent to CdS NCs. The second method (called amplification method) is based on an amplification mechanism in which the plasmonics on the AuNPs enhance the emission of CdS NCs through distance related Förster resonance energy transfer (FRET). The third method is ratiometric and based on the emission by two luminophores, viz. CdS NCs and luminol. In this method, by increasing the concentration of thrombin, the intensity of CdS NCs decreases, while that of luminol increases. The results showed that ratiometric method was most sensitive (with an LOD of 500 fg.mL-1), followed by the amplification method (6.5 pg.mL-1) and the quenching method (92 pg.mL-1). Hence, the latter is less useful. Graphical abstract Schematic representation of three different methods (quenching, amplification and ratiometric) were applied for detection of thrombin via aptasensor. The CdS nanocrystals, streptavidin (Str) coated AuNPs and also Str-luminol coated AuNPs were used for the construction steps of the electrochemiluminescence (ECL)-based biosensor.
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Aptâmeros de Nucleotídeos/metabolismo , Técnicas Biossensoriais/métodos , Compostos de Cádmio/química , Pontos Quânticos/química , Sulfetos/química , Trombina/análise , Aptâmeros de Nucleotídeos/genética , Sequência de Bases , Eletroquímica , Eletrodos , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Medições Luminescentes , Trombina/metabolismoRESUMO
Background: Knee osteoarthritis (KOA) is a chronic degenerative pathology that is associated with multiple risk factors such as age, sex, obesity, or metabolic syndrome (MetS). The present clinical trial aimed to investigate the influence of the environment of origin, body mass index (BMI), and MetS parameters on the KOA differentiated degrees. Methods: 85 patients were admitted for the clinical study. The KOA presence was investigated using X-rays analysis. The Kellgren−Lawrence classification (KL) of the KOA severity and the MetS characteristic parameters using freshly collected blood were performed for each patient. All data collected were used for ANOVA statistic interpretation. Results: The total cholesterol and glycemia were found to be statistically significant (p < 0.028, and p < 0.03, respectively), with a high level in patients with severe KOA compared to healthy ones. Patients from rural regions are 5.18 times more prone to develop severe KOA when compared to ones from urban areas. Conclusions: The results of the statistical analysis confirmed the correlation between the incidence and severity of KOA and the influence of increased values of BMI, glycemia, triglycerides, and total cholesterol. The investigations revealed a statistically significant influence of the environment of origin on the KOA degree of the patients.
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(1) Background: Prosthetically-driven implant positioning is a prerequisite for long-term successful treatment. Transferring the planned implant position information to the clinical setting could be done using either static or dynamic guided techniques. The 3D model of the bone and surrounding structures is obtained via cone beam computed tomography (CBCT) and the patient's oral condition can be acquired conventionally and then digitalized using a desktop scanner, partially digital workflow (PDW) or digitally with the aid of an intraoral scanner (FDW). The aim of the present randomized clinical trial (RCT) was to compare the accuracy of flapless dental implants insertion in partially edentulous patients with a static surgical template obtained through PDW and FDW. Patient outcome and time spent from data collection to template manufacturing were also compared. (2) Methods: 66 partially edentulous sites (at 49 patients) were randomly assigned to a PDW or FDW for guided implant insertion. Planned and placed implants position were compared by assessing four deviation parameters: 3D error at the entry point, 3D error at the apex, angular deviation, and vertical deviation at entry point. (3) Results: A total of 111 implants were inserted. No implant loss during osseointegration or mechanical and technical complications occurred during the first-year post-implants loading. The mean error at the entry point was 0.44 mm (FDW) and 0.85 (PDW), p ≤ 0.00; at implant apex, 1.03 (FDW) and 1.48 (PDW), p ≤ 0.00; the mean angular deviation, 2.12° (FDW) and 2.48° (PDW), p = 0.03 and the mean depth deviation, 0.45 mm (FDW) and 0.68 mm (PDW), p ≤ 0.00; (4) Conclusions: Despite the statistically significant differences between the groups, and in the limits of the present study, full digital workflow as well as partially digital workflow are predictable methods for accurate prosthetically driven guided implants insertion.
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Knee osteoarthritis (KOA) is a chronic multifactorial pathology and a current and essential challenge for public health, with a negative impact on the geriatric patient's quality of life. The pathophysiology is not fully known; therefore, no specific treatment has been found to date. The increase in the number of newly diagnosed cases of KOA is worrying, and it is essential to reduce the risk factors and detect those with a protective role in this context. The destructive effects of free radicals consist of the acceleration of chondrosenescence and apoptosis. Among other risk factors, the influence of redox imbalance on the homeostasis of the osteoarticular system is highlighted. The evolution of KOA can be correlated with oxidative stress markers or antioxidant status. These factors reveal the importance of maintaining a redox balance for the joints and the whole body's health, emphasizing the importance of an individualized therapeutic approach based on antioxidant effects. This paper aims to present an updated picture of the implications of reactive oxygen species (ROS) in KOA from pathophysiological and biochemical perspectives, focusing on antioxidant systems that could establish the premises for appropriate treatment to restore the redox balance and improve the condition of patients with KOA.
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The present study introduces the process performances of nitrophenols pertraction using new liquid supported membranes under the action of a magnetic field. The membrane system is based on the dispersion of silver-iron oxide nanoparticles in n-alcohols supported on hollow microporous polypropylene fibers. The iron oxide-silver nanoparticles are obtained directly through cyclic voltammetry electrolysis run in the presence of soluble silver complexes ([AgCl2]-; [Ag(S2O3)2]3-; [Ag(NH3)2]+) and using pure iron electrodes. The nanostructured particles are characterized morphologically and structurally by scanning electron microscopy (SEM and HFSEM), EDAX, XRD, and thermal analysis (TG, DSC). The performances of the nitrophenols permeation process are investigated in a variable magnetic field. These studies show that the flux and extraction efficiency have the highest values for the membrane system embedding iron oxide-silver nanoparticles obtained electrochemically in the presence of [Ag(NH3)2]+ electrolyte. It is demonstrated that the total flow of nitrophenols through the new membrane system depends on diffusion, convection, and silver-assisted transport.
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There is an increased interest in recycling valuable waste materials for usage in procedures with high added values. Silica microparticles are involved in the processes of catalysis, separation, immobilization of complexants, biologically active compounds, and different nanospecies, responding to restrictive requirements for selectivity of various chemical and biochemical processes. This paper presents the surface modification of accessible and dimensionally controlled recycled silica microfiber with titanium dioxide. Strong base species in organic solvents: methoxide, ethoxide, propoxide, and potassium butoxide in corresponding alcohol, activated the glass microfibres with 12-13 µm diameter. In the photo-oxidation process of a toxic micro-pollutant, cyclophosphamide, the new composite material successfully proved photocatalytic effectiveness. The present work fulfills simultaneously two specific objectives related to the efforts directed towards a sustainable environment and circular economy: recycling of optical glass microfibers resulted as waste from the industry, and their usage for the photo-oxidation of highly toxic emerging micro-pollutants.
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Citostáticos/química , Poluentes Ambientais/química , Vidro/química , Processos Fotoquímicos , Reciclagem/métodos , Dióxido de Silício/química , Resíduos , Catálise , Citostáticos/toxicidade , Poluentes Ambientais/toxicidade , Microesferas , Oxirredução , Propriedades de Superfície , Titânio/químicaRESUMO
Abstract: The present study aimed to assess the eighteen month follow-up patient-centered outcomes of a simple and predictable protocol for 3D-printed functional complete dentures manufactured using an improved poly(methyl methacrylate) (PMMA)-nanoTiO2. A detailed morphological and structural characterization of the PMMA-TiO2 nanocomposite, using SEM, EDX, XRD, and AFM, after 3D-printing procedure and post-wearing micro-CT, was also performed. METHODS: A total of 35 fully edentulous patients were enrolled in this prospective study. A 0.4% TiO2-nanoparticle-reinforced PMMA composite with improved mechanical strength, morphologically and structurally characterized, was used according to an additive computer-aided design and computer-aided manufacturing (CAD/CAM) protocol for complete denture fabrication. The protocol proposed involved a three-step appointment process. Before denture insertion, 1 week, 12 month, and 18-month follow up patients were evaluated via the Visual Analogue Scale (VAS, 0-10) and Oral Health Impact Profile for Edentulous Patients (OHIP-EDENT), with a higher score meaning poor quality of life. RESULTS: A total of 45 complete denture sets were inserted. OHIP-EDENT scored significantly better after 18 months of denture wearing, 20.43 (±4.42) compared to 52.57 (±8.16) before treatment; mean VAS was improved for all parameters assessed. CONCLUSIONS: Within the limitations of this study, we can state that the proposed workflow with the improved material used is a viable treatment option for patients diagnosed with complete edentulism.
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The preparation of membranes from polymer solutions by the phase inversion method, the immersion-precipitation technique has proved since the beginning of obtaining technological membranes the most versatile and simple possibility to create polymeric membrane nanostructures. Classically, the phase inversion technique involves four essential steps: Preparation of a polymer solution in the desired solvent, the formation of the polymer solution film on a flat support, the immersion of the film in a coagulation bath containing polymer solvents, and membrane conditioning. All phase inversion stages are important for the prepared membrane's nanostructure and have been studied in detail for more than six decades. In this paper, we explored, through an electrochemical technique, the influence of the contact time with the polymer film's environment until the introduction into the coagulation bath. The system chosen for membrane preparation is polysulfone-dimethylformamide-aqueous ethanol solution (PSf-DMF-EW). The obtained nanostructured membranes were characterized morphologically and structurally by scanning electron microscopy (SEM) and thermal analysis (TA), and in terms of process performance through water permeation and bovine serum albumin retention (BSA). The membrane characteristics were correlated with the polymeric film exposure time to the environment until the contact with the coagulation bath, following the diagram of the electrochemical parameters provided by the electrochemical technique.
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A series of sodium selective membranes with magnetic nano-inclusions using p-tertbutyl calix[4]arene as ionophore and polymeric matrix (polyvinyl chloride) have been developed, and the corresponding sodium selective sensors were obtained for the first time. A linear range was registered between 3.1 × 10-5 and 10-1moldm-3 and near Nernstian electrochemical answer: 55.73mV/decade has been recoreded for PVC (polyvinyl chloride) - based sodium selective sensor, with a response time of 45s. Due to their small dimensions, sensors could be used for measuring ions from the gingival crevicular fluid directly into the peri-odontal pocket, avoiding the difficulties of collecting an appropriate amount of fluid for analysis. Alterations in the inorganic ions level could be evidenced with this new device, assisting the early diagnosis and prevention of periodontal disease.
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Técnicas Biossensoriais , Íons/isolamento & purificação , Doenças Periodontais/diagnóstico , Sódio/isolamento & purificação , Diagnóstico Precoce , Líquido do Sulco Gengival/química , Humanos , Ionóforos/química , Membranas Artificiais , Cloreto de Polivinila/química , Potenciometria , Sódio/químicaRESUMO
OBJECTIVES: The aim of this study was to obtain a Poly(methylmethacrylate) (PMMA)-TiO2 nanocomposite material with improved antibacterial characteristics, suitable for manufacturing 3D printed dental prosthesis. METHODS: 0.2, 0.4, 0.6, 1, 2.5 by weight% of TiO2 nanoparticles have been added to the commercially available stereolithographic PMMA material and the obtained nanocomposites have been analyzed using FTIR, SEM and also tested for antimicrobial efficacy against bacterial cultures from Candida species (C. scotti). RESULTS: SEM images and EDX results highlighted the presence of TiO2 in PMMA nanocomposites. The elemental composition (EDX) also showed the presence of other fillers included in stereolithographic PMMA solution. FTIR analysis clearly revealed changes in polymeric matrix structure when adding TiO2 nanoparticles. Sample containing 0.4, 1 and 2.5wt% TiO2 nanoparticles inhibited the growth of Candida scotti strain in standard conditions according to the toxicity control method (DHA). Increasing quantity of nano-titania has resulted in particles fooling, forming new aggregates instead of the homogenous dispersion of nanoparticles with modified viscosity characteristics and expected lower mechanical parameters. CONCLUSIONS: Significant improvements in polymer characteristics and nice dispersion of the TiO2 nanoparticles have been noticed for 0.4wt%, therefore it was used for stereolitographic complete denture prototyping. CLINICAL SIGNIFICANCE: Incorporation of TiO2 nanoparticles in PMMA polymer matrix was proved to have antibacterial effects, specifically on Candida species. The newly obtained 0.4% nanocomposite was successfully used with stereolitographic technique for complete denture manufacturing. However, mechanical and biocompatibility tests need to be performed in order to extend the clinical usage.