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Radiat Environ Biophys ; 59(4): 583-600, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32780196


In recent decades, nanomaterials have been extensively investigated for many applications. Composites doped with different metal nanoparticles have been suggested as effective shielding materials to replace conventional lead-based materials. The use of concretes as structural and radiation protective material has been influenced by the addition of nanomaterials. Several elements with high atomic number and density, such as lead, bismuth, and tungsten, have the potential to form nanoparticles that offer significant enhancements in the shielding ability of composites. Their performance for a range of particle concentrations, particle sizes, and photon energies have been investigated. This review is an attempt to gather the data published in the literature about the application of nanomaterials in radiation shielding, including the use of polymer composites and concretes for protection against X-rays and gamma radiation.

Nanocompostos , Proteção Radiológica , Raios gama , Metais Pesados , Nanopartículas , Tamanho da Partícula , Fótons , Raios X
Artif Cells Nanomed Biotechnol ; 47(1): 436-442, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30704300


Gene and drug delivery systems need crucial update in the issue of nanocarriers. Layered double hydroxides (LDHs) are known as biocompatible inorganic lamellar nanomaterials with versatile properties. In the present study, Zn/Al-LDH nanoparticle was synthesized and characterized by FTIR, XRD, SEM, TEM and Zeta potential tests and then intercalated with valproate and methyldopa by co-precipitation and ion exchange methods. These nanocarriers were applied as high activity nanolayers-based delivery systems. On the other hand, Zn/Al-LDH + plasmid/gene (pCEP4/Cdk9) evaluated on C2C12 myoblast cells. Co-operation loading indicated high efficiency of sorting and release of drugs. Additionally, the Real-Time PCR and Western blotting results for plasmid-gene (pCEP4/Cdk9) delivery showed that Zn/Al-LDH nanoparticles can be used as an effective carrier in cellular uptake and release of genes for gene therapy. Easy and cost-effective production of Zn/Al-LDH nanoparticles proposed them as potential alternatives for the traditional routs of drug/gene delivery.

Portadores de Fármacos , Técnicas de Transferência de Genes , Hidróxidos , Mioblastos/metabolismo , Nanopartículas/química , Animais , Portadores de Fármacos/química , Portadores de Fármacos/farmacologia , Hidróxidos/química , Hidróxidos/farmacologia , Camundongos , Mioblastos/citologia , Pentamidina/química , Pentamidina/farmacologia , Plasmídeos/química , Plasmídeos/farmacologia , Poliésteres/química , Poliésteres/farmacologia
Eur J Dent ; 12(1): 105-110, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29657533


Objective: In this study, we compared the effects of 0.12% chlorhexidine (CHX) and nano zinc oxide (NZO) on the microshear bond strength of dentin with a fifth-generation adhesive after acid etching. Materials and Methods: Forty molar teeth were randomly divided into four main groups based on dentin surface treatment technique (a) control (single bond 2); (b) NZO; (c) CHX; and (d) NZO + CHX. In each group, half of the samples underwent thermocycling, with no thermocycling in the other half. Then, failure mode was evaluated under a stereomicroscope. Statistical analysis was performed using t-test, two-way ANOVA, and Chi-squared test. Results: The mean microshear bond strength of the groups without thermocycling was more than that of the groups with thermocycling, but there were no statistically significant differences between the groups with and without thermocycling in pair-wise comparisons. Conclusion: Pretreatment with NZO and CHX separately and simultaneously had no effect on the microshear bond strength of a fifth-generation adhesive.

Iran J Psychiatry Behav Sci ; 8(1): 5-12, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24995024


OBJECTIVE: Providing treatment and educational services for consumers and their caregivers is more effective if those services are implemented based on their characteristics and differences. To partly address this objective, the present study aimed to describe and compare characteristics and differences of chronic hospitalized and household maintained consumers and their caregivers who were regular users of educational and rehabilitation programs of the Iranian Society Supporting Individuals with Schizophrenia (ISSIS) in Tehran, Iran. METHODS: Two hundred and thirty one consumers were evaluated based on demographics, and clinical and symptom-related characteristics. Their caregivers (n = 231) were independently evaluated based on their knowledge on schizophrenia, family function, burden, and availability of social services and support for them. Data were analyzed by performing independent sample t-test and Mann-Whitney U. RESULTS: The study findings revealed hospitalized consumers were older, had longer length of illness, greater severity of positive and negative symptoms and lower efficacy in basic life skills in comparison with household maintained consumers. The caregivers of the hospitalized consumers had greater objective and subjective burdens and lower knowledge on schizophrenia in comparison with caregivers of household maintained consumers. While household maintained consumers had more access to medical insurance, their caregivers had more access to the supportive organizations, more availability of substitute caregiver and assistant caregiver compared with caregivers of hospitalized consumers. CONCLUSION: Our findings suggest the need to promote specific interventions and treatment programs for Iranian consumers and their caregivers based on their characteristics and differences due to schizophrenia. DECLARATION OF INTEREST: None.