Percorrer por autor "Silva, Francisco"
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- Antitumoral and antimicrobial activities of block copolymer micelles containing gold bisdithiolate complexesPublication . Sousa, Andreia; Santos, Joana F.; Silva, Francisco; Sousa, Sílvia A.; Leitão, Jorge H.; Matos, António P.; Pinheiro, Teresa; Silva, Rafaela A. L.; Belo, Dulce; Almeida, Manuel; Marques, Fernanda; Fernandes, CéliaGold(III) bisdithiolate complexes have been reported as potential antimicrobial and antitumoral agents. The complex [Au(cdc)2]− (cdc=cyanodithioimido carbonate) displayed antimicrobial and outstanding antitumor activity against the ovarian cancer cells A2780 and A2780cisR, which are sensitive and resistant to cisplatin, respectively. However, poor water solubility may hamper its clinical use. Block copolymer micelles (BCMs) may solubilize hydrophobic drugs, improving their bioavailability and circulation time in blood. Aiming to provide water solubility, prolonged availability, and enhanced therapeutic indexes, BCMs loaded with [Au(cdc)2]− were synthesized and characterized. The BCM-[Au(cdc)2] micelles were prepared with a loading efficiency of 64.6% and a loading content of 35.3 mg [Au(cdc)2]−/gBCM. A hydrodynamic diameter of 77.31 ± 27.00 nm and a low polydispersity index of 0.18 indicated that the micelles were homogenous and good candidates for drug delivery. Cytotoxic activity studies against A2780/A2780cisR cells showed that BCM-[Au(cdc)2] maintained relevant cytotoxic activity comparable to the cytotoxicity observed for the same concentration of gold complexes. The Au uptake in A2780 cells, determined by PIXE, was ca. 17% higher for BCMs-[Au(cdc)2] compared to [Au(cdc)2]−. The BCMs-[Au(cdc)2] presented antimicrobial activity against S. aureus Newman and C. glabrata CBS138. These results evidenced the potential of BCM-[Au(cdc)2] for drug delivery and its promising anticancer and antimicrobial activities.
- Dose rate effects on the selective radiosensitization of prostate cells by GRPR-targeted gold nanoparticlesPublication . Marques, Ana; Belchior, Ana; Silva, Francisco; Marques, Fernanda; Campello, Maria Paula Cabral; Pinheiro, Teresa; Santos, Pedro; Santos, Luis; Matos, António P. A.; Paulo, AntónioFor a while, gold nanoparticles (AuNPs) have been recognized as potential radiosensitizers in cancer radiation therapy, mainly due to their physical properties, making them appealing for medical applications. Nevertheless, the performance of AuNPs as radiosensitizers still raises important questions that need further investigation. Searching for selective prostate (PCa) radiosensitizing agents, we studied the radiosensitization capability of the target-specific AuNP-BBN in cancer versus non-cancerous prostate cells, including the evaluation of dose rate effects in comparison with non-targeted counterparts (AuNP-TDOTA). PCa cells were found to exhibit increased AuNP uptake when compared to non-tumoral ones, leading to a significant loss of cellular proliferation ability and complex DNA damage, evidenced by the occurrence of multiple micronucleus per binucleated cell, in the case of PC3 cells irradiated with 2 Gy of γ-rays, after incubation with AuNP-BBN. Remarkably, the treatment of the PC3 cells with AuNP-BBN led to a much stronger influence of the dose rate on the cellular survival upon γ-photon irradiation, as well as on their genomic instability. Overall, AuNP-BBN emerged in this study as a very promising nanotool for the efficient and selective radiosensitization of human prostate cancer PC3 cells, therefore deserving further preclinical evaluation in adequate animal models for prostate cancer radiotherapy.
- Pesquisa, citação e referenciação bibliográfica : orientações práticasPublication . Conceição, Cristina Palma; Silva, FranciscoO presente texto pretende orientar a investigação e a consequente elaboração de trabalhos académicos na Escola Superior de Hotelaria e Turismo do Estoril (ESHTE), nomeadamente a citação, a referenciação bibliográfica, a estrutura e a redação, de acordo com normas internacionalmente reconhecidas. São incluídas as ferramentas de inteligência artificial (IA), dada a sua importância no panorama atual do desenvolvimento tecnológico, e que se reflete de igual modo na investigação e produção académicas.
- O Terrorismo InternacionalPublication . Silva, FranciscoConsiderando o impacto do terrorismo na liberdade e segurança das populações nos países ocidentais e, mais especificamente, em Portugal, quer considerado de forma individualizada, quer como parte de organizações internacionais, nomeadamente a NATO e a União Europeia, o presente trabalho de investigação individual analisa o terrorismo internacional, averiguando se deve constituir uma missão para as Forças Armadas ou para as Forças de Segurança, e se existem formas de cooperação e delimitação das áreas de actuação. Após, numa breve análise histórica, examinar as várias formas que o terrorismo assumiu no passado e qual a situação actual, o estudo detém-se com maior detalhe na legislação, na organização e nas capacidades das Forças Armadas e das Forças de Segurança para o combate ao terrorismo internacional de modo a verificar a sua adequação ou se existem lacunas, e quais. Em seguida, compara os resultados obtidos na análise descrita com situações semelhantes para propor soluções que permitam ultrapassar as lacunas identificadas e propõe um modelo de cooperação entre as Forças Armadas e as Forças de Segurança para o combate ao terrorismo internacional, cuja adequação e adaptação à realidade nacional está comprovada. Abstract: Considering the impact of terrorism upon the security and freedom of the populations in western countries and, more specifically, Portugal, taken both individually or as part of wider international organizations, namely NATO and the European Union, this paper deals with the International Terrorism, arguing whether it should be a mission for the Armed Forces or the Security Forces and whether there are ways of cooperation and a delimitation of areas of operation. After examining the historical background, the various forms that terrorism has assumed in the past and the current situation, the paper analyses the legal framework, the organization and the capabilities of the Portuguese Armed Forces and Security Forces to fight international terrorism in order to verify whether they are adequate or if there are outstanding shortfalls. It then compares the findings with similar situations to propose remedial actions that should be undertaken to overcome the identified shortfalls and offers a model whose suitability and appropriateness is proven in real life.