RESUMO
Reclaimed asphalt pavements (RAP) provide economic and environmental benefits. In recent decades, their use has increased, but rheological properties are affected by RAP aging, increasing stiffness, cracking, and susceptibility to water. To counteract these effects, rejuvenating agents are used, but they must be properly dosed to design quality mixtures. Therefore, different binders were analyzed, including virgin binder (VBB), binder modified by SBS polymer (MB), AC-RAP, binder softened using a rejuvenating agent, and binders softened with doses (15%, 30%, and 45%) of AC-RAP. The rheological properties were evaluated by dynamic shear rheometry (DSR) and beam-bending rheometry (BBR) tests, while the linear amplitude sweep (LAS) test was used to measure fatigue cracking and the multiple stress creep recovery (MSCR) test was used to measure rutting. A mixing chart was constructed based on a high temperature AC-RAP to satisfy the performance grade (PG 76-22). The results showed that softened binders become flexible, but when AC-RAP is added, they turn stiff and behave better than MB. Moreover, combining a rejuvenating agent and AC-RAP reduces the aging stiffness of RAP, improving its rheological properties without compromising the rutting or cracking resistance.
RESUMO
Researchers in cancer nanomedicine are exploring a revolutionary multifaceted carrier for treatment and diagnosis, resulting in the proposal of various drug cargos or "magic bullets" in this past decade. Even though different nano-based complexes are registered for clinical trials, very few products enter the final stages each year because of various issues. This prevents the formulations from entering the market and being accessible to patients. In the search for novel materials, the exploitation of 2D nanosheets, including but not limited to the highly acclaimed graphene, has created extensive interest for biomedical applications. A unique set of properties often characterize 2D materials, including semiconductivity, high surface area, and their chemical nature, which allow simple decoration and functionalization procedures, structures with high stability and targeting properties, vectors for controlled and sustained release of drugs, and materials for thermal-based therapies. This review discusses the challenges and opportunities of recently discovered 2D nanosheets for cancer therapeutics, with special attention paid to the most promising design technologies and their potential for clinical translation in the future.
RESUMO
Heparin-based silver nanoparticles (AgHep-NPs) and gold nanoparticles (AuHep-NPs) were produced by a photochemical method using silver nitrate and chloroauric acid as metal precursors and UV light at 254 nm. UV-Vis spectroscopy graphs showed absorption for AgHep-NPs and AuHep-NPs at 420 nm and 530 nm, respectively. TEM revealed a pseudospherical morphology and a small size, corresponding to 10-25 nm for AgHep-NPs and 1.5-7.5 nm for AuHep-NPs. Their antifungal activity against Candida albicans, Issatchenkia orientalis (Candida krusei), and Candida parapsilosis was assessed by the microdilution method. We show that AgHep-NPs were effective in decreasing fungus density, whereas AuHep-NPs were not. Additionally, the viability of human gingival fibroblasts was preserved by both nanoparticle types at a level above 80%, indicating a slight cytotoxicity. These results are potentially useful for applications of the described NPs mainly in dentistry and, to a lesser extent, in other biomedical areas.
Assuntos
Antifúngicos , Candida/crescimento & desenvolvimento , Citotoxinas , Fibroblastos/metabolismo , Gengiva/metabolismo , Ouro , Nanopartículas Metálicas/química , Processos Fotoquímicos , Prata/química , Antifúngicos/síntese química , Antifúngicos/química , Antifúngicos/farmacologia , Linhagem Celular , Citotoxinas/síntese química , Citotoxinas/química , Citotoxinas/farmacologia , Ouro/química , Ouro/farmacologia , HumanosRESUMO
El propósito de este estudio fue caracterizar los componentes de los cementos comerciales para uso en odontología MTA Angelus ® Blanco (Angelus, Lodrina, Paraná Brasil) y de Biodentine TM (Septodont, Saint-Maur-des Fosses, Francia) mediante Microscopia Electrónica de Barrido, difracción de rayos X, fluorescencia de rayos X, espectrometría de dispersión de electrones y espectroscopia infrarroja. Los dos cementos se mezclaron según las indicaciones del fabricante. Se les practicó un estudio de textura de superficie mediante el microscopio electrónico de barrido (MEB), un análisis de difracción de rayos X (DRX), un análisis de fluorescencia de rayos X (FRX), un análisis de espectrometría de energía dispersiva (EDS) y un análisis de espectroscopia infrarroja (IR), para determinar los grupos funcionales. Resultados: Se presentó una diferencia en el análisis XRD entre Biodentine presentó Na2O y ZrO2 mientras que están ausentes en el MTA. El MTA presentó Cr2O3 y BiO2 ausentes en el Biodentine. En el análisis de EDS las diferencias fueron en el agente radiopacador y que el Biodentine presentó Cl a diferencia del MTA y en el análisis estadístico realizado, a pesar de que prácticamente se presentaron los mismos componentes, los porcentajes en los contenidos de éstos fueron estadísticamente signifi cativos. En el análisis de MEB hay una gran diferencia, el MTA presenta una superfi cie porosa e irregular, el Biodentine una forma fi brilar e irregular. Conclusión: Existe una gran similitud en los componentes químicos entre el MTA Angelus y Biodentine con excepción de los componentes químicos para proporcionarles radiopacidad, el tamaño y la forma del grano y en el caso del Biodentine el cloruro de calcio.
The aim of the present study was to characterize components of commercial cements used in dentistry MTA Angelus® White (Angelus Lodrina, Parana Brazil) and Biodentine TM (Septodont, Saint-Maurdes Fosses, France). Techniques used for said characterization were Scanning Electron Microscope, X-Ray Diffraction, X Ray Fluorescence, Electron Dispersion Spectrometry, and Infrared Spectroscopy. Both cements were mixed according to manufactures instructions. A study of surface texture was conducted with Scanning Electron Microscope (SEM), and X Ray Diffraction (XRD) analysis, and X Ray fluorescence analysis (XRF), an analysis of Dispersive Energy Spectrometry (DES), as well as an Infra Red Spectroscopy (IRS) in order to determine functional groups. Results: In XRD analysis, a difference was found: Biodentine exhibited Na2O and ZrO2. These elements were absent in MTA. MTA presented Cr2O3 and BiO2 which in turn were absent in Biodentine. EDS analysis revealed that differences were found in the radio-opacifying agent, and that Biodentine presented CaCl2 differing in this from MTA. Statistical analysis conducted revealed statistically signifi cant percentages in contents, even though components were found to be practically the same. SEM analysis revealed marked differences: MTA presented irregular and porous surface whereas Biodentine exhibited irregular and filament form. Conclusion: There is a great similarity in the chemical components of MTA Angelus and Biodentine, with the exception of chemical components providing radio-opacity, the size and form of the grain, and, in Biodentine presence of calcium chloride.