167 research outputs found
Caracterização morfológica da plataforma da ilha do Faial
A plataforma insular do Faial foi cartografada com recurso a um vasto conjunto de dados geofísicos e geológicos. A análise da
morfologia da plataforma permitiu perceber quais os factores que mais contribuiram para a sua evolução
Serum lipids and prostate cancer
Background: Conflicting results are found in the literature relating serum lipids levels and prostate cancer. Some results imply a relationship between them; others contradict this association. The purpose of this study was to investigate a possible association between serum lipids levels and prostate cancer, at time of diagnosis. Methods: We measured serum levels of total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides in 237 patients submitted to a prostate biopsy, with PSA between 2 and 10 ng/ml. Patients without cancer at biopsy were used as controls, and the others were considered as cases. No information about lipid-lowering therapy, including statins, was available neither in cases nor in controls. Cases were divided into risk groups, according to the disease severity, based on staging. Lipids levels were compared between groups, using parametric and nonparametric tests. Logistic regression analysis and odds ratios were calculated. Results: LDL and total cholesterol levels were lower in patients with cancer, with the difference being statistically significant for LDL cholesterol (p = 0.010) and borderline for total cholesterol (p = 0.050). No significant differences were found between the several risk groups. Odds ratios for low LDL cholesterol (<130 mg/dl) and low total cholesterol (<200 mg/dl), with prostate cancer as the outcome, were 1.983 and 1.703, respectively. There were no significant differences between cases and controls for the other lipids. Conclusion: Lower LDL cholesterol (<130 mg/dl) and lower total cholesterol (<200 mg/dl) serum levels seem to associate with prostate cancer, at time of diagnosis.publishersversionpublishe
Nanoemulsions for enhancement of curcumin bioavailability and their safety evaluation: effect of emulsifier type
This work aimed at evaluating the effects of different emulsifiers on curcumin-loaded nanoemulsions behavior during digestion, its safety and absorption, to develop nanoemulsions that provide safety and improved curcumin functionality. Nanoemulsions (NEs) were produced using two bio-based (lecithin (LEC) and rhamnolipids (RHAM)) and one synthetic (Tween®80 (TWE)) emulsifier at similar concentrations. Different NEs were subjected to in vitro digestion. The cytotoxicity and permeability tests were performed in Caco-2 cells. NE_TWE were stable during all phases of in vitro digestion, whereas NE_LEC and NE_RHAM were found to be unstable from the gastric phase. NE_TWE showed 100% of free fatty acids released, followed by NE_RHAM and NE_LEC. Curcumins bioaccessibility and stability increased in the following order: NE_LEC > NE_RHAM > NE_TWE. NE_LEC and NE_TWE did not show cytotoxic effects in any of the concentrations tested, while NE_RHAM presented high cytotoxicity in all concentrations tested. The apparent permeability coefficients were determined for NE_LEC and NE_TWE; however, the results were not statistically different. These results showed that the emulsifier used has a high impact on nanoemulsions behavior under the digestion process and on their cytotoxicity. This work contributed to the state-of-the-arts progress on the development of safer curcumin delivery systems with improved functionality, particularly regarding the proper selection of ingredients to produce said systems.This study was supported by the Portuguese Foundation for Science and Technology (FCT)
under the scope of the strategic funding of UIDB/04469/2020 unit and under the scope of project
PTDC/AGR-TEC/5215/2014.info:eu-repo/semantics/publishedVersio
Boreholes plans optimization methodology combining geostatistical simulation and simulated annealing
Nowadays, the prospection plans have the difficult task of ensuring a more complete and rich characterization of the rock mass for the purpose of optimizing costs and increasing safety in geotechnical projects. Currently, boreholes location and depth are mainly defined based on experience and know-how of professionals, as such, it is user-dependent. Hence, there is a lack of methodologies to help the decision-makers in defining the optimal location of boreholes (with relevant information). Therefore, this paper presents a methodology based on the use of geostatistical conditional simulation allied to a stochastic global optimization algorithm (Simulated Annealing) to develop optimized boreholes plans comparing a uni-objective and a multi-criteria optimization approaches. In this work, the optimized location is considered the one that minimizes uncertainty translated by either the average local variance or the average width of 95% probability intervals of simulated values at unsampled locations. This methodology was applied using preliminary information obtained from previously executed boreholes using as variable the empirical rock mass classification system, Rock Mass Rating, in a Chilean deposit.This research is inserted in LNEC project named P2I-RockGeoStat and was partially funded by FCT (Fundação para a Ciência e Tecnologia, Portugal) in the scope of project PEst-UID/CEC/00319/2013, included in ISISE project UID/ECl/04029/2013 as well as the PhD grant SFRH/BD/89627/2012, and by the Chilean Commission for Scientific and Technological Research, through Project CONICYT PIA Anillo ACT1407.info:eu-repo/semantics/publishedVersio
Borehole plan optimization in rock masses using geostatistical simulation
The economical and safety aspects related with geotechnical engineering, in detail with prospecting works, are significant and increasingly complex. Therefore, optimizing costs that simultaneously guarantee the quantity and quality of information to characterize the rock mass are, nowadays, one of the most important factors in underground works.
The borehole plans, normally defined using the knowhow of a professional, imply large costs in the geotechnical industry, thus this paper presents a new methodology allowing the optimization of such plans. This methodology allies geostatistical techniques (turning bands simulation to model rock mass properties like the Rock Mass Rating or RMR) with a stochastic global optimization algorithm, Simulated Annealing (SA). It relies on sparse information about RMR and randomly generates new points that intend to represent possible locations for additional boreholes. Furthermore, SA is adapted to perform the optimization of a set of points with different depth coordinates in order to represent the reality of the mechanical boreholes, where the information is obtained along the hole. Considering the number of additional boreholes to drill, SA finds a global solution minimizing an objective function, which aims at quantifying the uncertainty on RMR at locations without information.
An application to a gold mine deposit located in Chile is finally presented in order to illustrate and validate the methodology.Agência de Desenvolvimento Económico do Chile através do projeto Innova Chile-CORFO 11IDL2-10630Comissão Científica e Tecnológica de Investigação chilena através dos projetos CONICYT / FONDECYT / REGULAR / N°1130085 e CONICYT PIA Anillo ACT 1407P2I-RockGeoStat do LNE
Synthesis and antibacterial activity of ionic liquids and organic salts based on penicillin g and amoxicillin hydrolysate derivatives against resistant bacteria
Fundacao para a Ciencia e Tecnologia through projects (PTDC/QUI-QOR/32406/2017, PEst-C/LA0006/2013) and PTDC/BTM-SAL/29786/2017, and one contract under Investigador FCT (L.C.B.).
ZP thanks to Fundacao para a Ciencia e a Tecnologia, MCTES, for the Norma transitoria DL 57/2016 Program Contract.
This work was also supported by the Associate Laboratory for Green Chemistry, which is financed by national funds from FCT/MEC, UIDB/50006/2020 and co‐financed by the ERDF under the PT2020 Partnership Agreement (POCI‐01‐ 0145‐FEDER‐007265). The authors also thank Solchemar company for support.The preparation and characterization of ionic liquids and organic salts (OSILs) that contain anionic penicillin G [secoPen] and amoxicillin [seco-Amx] hydrolysate derivatives and their in vitro antibacterial activity against sensitive and resistant Escherichia coli and Staphylococcus aureus strains is reported. Eleven hydrolyzed β-lactam-OSILs were obtained after precipitation in moderate-to-high yields via the neutralization of the basic ammonia buffer of antibiotics with different cation hydroxide salts. The obtained minimum inhibitory concentration (MIC) data of the prepared compounds showed a relative decrease of the inhibitory concentrations (RDIC) in the order of 100 in the case of [C2OHMIM][seco-Pen] against sensitive S. aureus ATCC25923 and, most strikingly, higher than 1000 with [C16Pyr][seco-Amx] against methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300. These outstanding in vitro results showcase that a straightforward transformation of standard antibiotics into hydrolyzed organic salts can dramatically change the pharmaceutical activity of a drug, including giving rise to potent formulations of antibiotics against deadly bacteria strains.publishersversionpublishe
Development and characterization of nanostructured lipid carriers for cannabidiol delivery
Supplementary data to this article can be found online at https://doi.org/10.1016/j.foodchem.2023.138295.This study evaluated the physicochemical characteristics of nanostructured lipid carriers (NLCs) as a potential vehicle for cannabidiol (CBD), a lipophilic molecule with great potential to promote health benefits. NLCs were produced using hemp seed oil and fully-hydrogenated soybean oil at different proportions. The emulsifiers evaluated were soybean lecithin (SL), Tween 80 (T80) and a mixture of SL:T80 (50:50). CBD was tested in the form of CBD-rich extract or isolate CBD, to verify if it affects the NLCs characteristics. Based on particle size and polydispersity, SL was considered the most suitable emulsifier to produce the NLCs. All lipid proportions evaluated had no remarkable effect on the physicochemical characteristics of NLCs, resulting in CBD-loaded NLCs with particle size below 250 nm, high CBD entrapment efficiency and CBD retention rate of 100% for 30 days, demonstrating that NLCs are a suitable vehicle for both CBD-rich extract or isolate CBD.This study received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie SkłodowskaCurie grant agreement No 101062938 and was supported by Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit, and by LABBELS – Associate Laboratory in Biotechnology, Bioengineering and Microelectromechanical Systems, LA/P/0029/2020. Fernanda L. Lüdtke thanks Iceland Liechtenstein Norway Grants (PT-INNOVATION-0105) for the fellowship
Volatiles of the Inflorescences of the Madeiran Orchids, Goodyera macrophylla Lowe and Gennaria diphylla (Link) Parl. and Their Role in Pollination
Goodyera macrophylla, considered a rare endemic, and Gennaria diphylla are two native terrestrial Orchidaceae species that
can be found mainly in Madeiran Laurisilva. The volatile compounds contributing to the floral scent of these two Madeiran
orchids were analysed and compared for the first time. The volatiles, isolated by distillation-extraction in a Likens-Nickersontype apparatus, and those extracted by headspace sorption, were analysed by GC and GC-MS. The main volatile components
isolated by distillation-extraction were γ-terpinene (13%) and n-nonanal (11%) in G. macrophylla and n-octacosane (19%)
and n-heptacosane (13%) in G. diphylla. The main volatile components isolated by headspace sorption were p-cymene (21%),
α-pinene (15%) and linalool (14%) in G. macrophylla and cis-arbusculone (28%) and lilac alcohol (26%) in G. diphylla. The
importance of the volatiles in the pollination of these orchids is discussed.Portuguese Foundation for the
Science and Technology (FCT, Fundação para a
Ciência e Tecnologia) has sponsored this work,
through the Centre of Macaronesian Studies (CEM).
The authors are also grateful to the Madeiran Centre
of Science and Technology (CITMA) for financial
support.info:eu-repo/semantics/publishedVersio
Optimization of wood flour acetylation by factorial design and partial least squares regression
Acetylation was performed to reduce the polarity of wood and increase its compatibility with polymer matrices for the production of composites. These reactions were performed first as a function of acetic acid and anhydride concentration in a mixture catalyzed by sulfuric acid. A concentration of 50%/50% (v/v) of acetic acid and anhydride was found to produced the highest conversion rate between the functional groups. After these reactions, the kinetics were investigated by varying times and temperatures using a 3² factorial design, and showed time was the most relevant parameter in determining the conversion of hydroxyl into carbonyl groups
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