•Three different biopolymeric films composed by chitosan, Peg and gelatin were developed.•Porphyrin dye was successfully incorporated into the different films.•Their spectral-luminescent properties ...were investigated including fluorescence lifetimes, quantum yields, singlet oxygen formation and Triplet–triplet absorption spectra.•Intracellular localization studies of the compounds under study were performed onto HeLa cells.•The anticancer activity of all the generated systems was evaluated.
Porphyrins and some of its derivatives are well known and widely used as photosensitizers (PSs) for Photodynamic Therapy of Cancer (PDT).
The present study regards the characterization and evaluation of a synthesized asymmetric porphyrin dye in solution to be used as PS for PDT. This molecule was also incorporated into biopolymeric films composed by chitosan, polyethylene glycol (PEG) and gelatin in order to overtake some of the disadvantages inherent to the PS, but more important, to evaluate the potential of a system composed by the porphyrin/biopolymer to be applied as localized therapeutic agents.
FTIR spectroscopy showed a strong interaction between the polymers involved in the preparation of the films under study: film 1: chitosan, film 2: chitosan/PEG and film 3: chitosan/gelatin.
Photochemical studies were performed for the dye in solution and into the three different biopolymeric films. Ground state absorption showed the characteristic bands of these kinds of dyes in solution and also incorporated into the films. The films composed by porphyrin/chitosan and porphyrin into chitosan/gelatin, revealed the presence of non-emissive aggregates exhibiting a strong quenching effect in the fluorescence intensity, quantum yields and lifetimes. In this way, the system composed by the porphyrin incorporated into the chitosan/PEG film presents the best fluorescence quantum yield and lifetime.
The transient absorption spectra were obtained for all the systems indicating the formation of an excited triplet state of the porphyrins following excitation, which takes special importance in the generation of phototoxic species namely singlet oxygen.
Singlet oxygen quantum yields were also determined and the results obtained were very promising for the dye in solution but also for the dye into the different substrates. The release of the dye from the three different films onto a buffer solution was evaluated and we conclude that after a few days the dye was completely released by the substrates in acidic conditions.
Confocal microscopy was used for the determination of the intracellular localization of the compound under study onto HeLa cells (human cervical cancer cells line).
The evaluation of the PSs anticancer activity assumes special importance for PDT studies. The system should be less toxic in the dark and more active when irradiated, therefore, toxicity in the dark and phototoxicity studies onto HeLa cells were performed.
Recently, increased attention has been paid to the link between gut microbial composition and obesity. Gut microbiota is a source of endotoxins whose increase in plasma is related to obesity and ...insulin resistance through increased intestinal permeability in animal models; however, this relationship still needs to be confirmed in humans. That intestinal permeability is subject to change and that it might be the interface between gut microbiota and endotoxins in the core of metabolic dysfunctions reinforce the need to understand the mechanisms involved in these aspects to direct more efficient therapeutic approaches. Therefore, in this review, we focus on the emerging link between obesity and increased intestinal permeability, including the possible factors that contribute to increased intestinal permeability in obese subjects. We address the concept of intestinal permeability, how it is measured, and the intestinal segments that may be affected. We then describe 3 factors that may have an influence on intestinal permeability in obesity: microbial dysbiosis, dietary pattern (high-fructose and high-fat diet), and nutritional deficiencies. Gaps in the current knowledge of the role of Toll-like receptors ligands to induce insulin resistance, the routes for lipopolysaccharide circulation, and the impact of altered intestinal microbiota in obesity, as well as the limitations of current permeability tests and other potential useful markers, are discussed. More studies are needed to reveal how changes occur in the microbiota. The factors such as changes in the dietary pattern and the improvement of nutritional deficiencies appear to influence intestinal permeability, and impact metabolism must be examined. Also, additional studies are necessary to better understand how probiotic supplements, prebiotics, and micronutrients can improve stress-induced gastrointestinal barrier dysfunction and the influence these factors have on host defense. Hence, the topics presented in this review may be beneficial in directing future studies that assess gut barrier function in obesity.
Squaraine dyes have recently attracted interest as potential second generation photosensitizers for photodynamic therapy. Several cationic aminosquaraine dyes bearing benzoselenazole terminal nuclei ...were synthezised and their cytotoxic activity was tested against four different human tumor cell lines - breast (MCF-7), non-small cell lung (NCI-H460), cervical (HeLa) and hepatocellular (HepG2) carcinomas - and against a non-tumor porcine liver primary cell line (PLP2), both in the absence of light and under irradiation. All dyes, which displayed strong absorption within the phototherapeutic window, were found to exhibit photodynamic activity and were shown to be, in most cases, more cytotoxic, both in the dark and upon irradiation, than their benzothiazole analogues.
In this work, a squaraine dye CS5 was characterized and evaluated for its potential in photodynamic therapy. The studies were performed in ethanol and also in a powdered biopolymer, in this case ...chitosan. Ground state absorption, absolute fluorescence quantum yields, fluorescence lifetimes, and transient absorption were determined in order to evaluate the advantage of adsorbing the dye onto a biopolymer. Several concentrations of the dye, adsorbed onto chitosan, were prepared in order to evaluate the concentration effect on the photophysical parameters under study. A remarkable increase in the fluorescence quantum yield and lifetimes was detected when compared with the dye in solution. Also, a very clear dependence of the fluorescence quantum yield on the concentration range was found. A lifetime distribution analysis of these systems fluorescence evidenced the entrapment of the dye onto the chitosan environment with a monoexponential decay which corresponds to the monomer emission in slightly different environments. The transient absorption spectrum was obtained without sensitization indicating the existence of a triplet state which takes special importance in the generation of phototoxic species namely singlet oxygen. The subcellular localization of a photosensitizer is critical for efficient photoinduced cell death, in this way, colocalization studies were performed within HeLa cell line (human cervical carcinoma) through confocal microscopy. Toxicity in the dark and phototoxicity of CS5 were also evaluated for the same cellular model.
SCFA provide energy to the host and influence lipid and glucose metabolism, suggesting that they may have an impact on the occurrence of metabolic risk factors. The aim of the present study was to ...determine the concentration of SCFA in faeces of lean and obese individuals and to analyse whether associations between faecal SCFA and metabolic syndrome parameters are present. Lean (n 20) and obese (n 20) women of similar age (28·5 (sd 7·6) v. 30·7 (sd 6·5) years, P= 0·33) participated in the study. Anthropometric measurements, body composition, blood pressure and biochemical parameters were assessed. SCFA were extracted from faeces and quantified by GC. Blood pressure and blood glucose, although within the normal limits, were higher in the obese group compared to lean subjects (P< 0·05). Lower HDL concentration and higher insulin and homeostasis model assessment (HOMA) index were observed in the obese than in the lean group (P< 0·05). The median values of SCFA (% w/w) from the lean and obese groups were butyric (0·021 v. 0·044, P= 0·024), propionic (0·021 v. 0·051, P= 0·007) and acetic (0·03 v. 0·061, P= 0·01). SCFA correlated positively with metabolic syndrome risk factors such as adiposity, waist circumference and HOMA index (P< 0·05), and inversely with HDL (P< 0·05). Our results suggest that the higher faecal concentration of SCFA is associated with metabolic risk factors and thus may influence metabolic homeostasis.
Single-pixel imaging is an imaging technique that has recently attracted a lot of attention from several areas. This paper presents a study on the influence of the Hadamard basis ordering on the ...image reconstruction quality, using simulation and experimental methods. During this work, five different orderings, Natural, Walsh, Cake-cutting, High Frequency and Random orders, along with two different reconstruction algorithms, TVAL3 and NESTA, were tested. Also, three different noise levels and compression ratios from 0.1 to 1 were evaluated. A single-pixel camera was developed using a digital micromirror device for the experimental phase. For a compression ratio of 0.1, the Cake-cutting order achieved the best reconstruction quality, while the best contrast was achieved by Walsh order. For compression ratios of 0.5, the Walsh and Cake-cutting orders achieved similar results. Both Walsh and Cake-cutting orders reconstructed the images with good quality using compression ratios from 0.3. Finally, the TVAL3 algorithm showed better image reconstruction quality, in comparison with NESTA, when considering compression ratios from 0.1 to 0.5.
Ceramic sherds from approximately 20 samples of lead-glazed tableware, recovered from diverse archaeological sites, including three repurposed storage pits transformed into dumpsters within the ...medieval city of Santarém (13th–14th century), underwent a meticulous examination. This investigation utilised techniques such as micro-Raman, ground-state diffuse reflectance absorption, and X-ray fluorescence spectroscopies, in addition to X-ray diffraction and stereomicroscopy. A parallel study was conducted on contemporaneous European ceramics (glazed sherds) sourced from archaeological sites dating back to the 13th–15th centuries in Saintonge (France), Ardenne, Zomergem, and Bruges (Belgium), as well as Surrey–Hampshire, Kingston, and Cheam (England). The first premise for comparing the Santarem samples with European production locations was their frequent commercial relations with Portugal and the frequency of these productions being found in Portugal. The colour of the ceramic bodies is predominantly white or whitish, with a few exhibiting a vivid red hue. Analyses of the fabric, mineralogical, and elemental composition of the sherds suggest that the majority of Santarém’s glazed ceramics were locally or regionally produced, potentially derived from a Pliocene kaolin-rich sand formation. However, this conclusion is not supported by the absence of discovered lead glaze kilns or workshops in Santarém for the late Middle Ages.
The results of three Partial Least Squares (PLS) regression models were used to gain a holistic view on the consequences of natural processes and anthropogenic pressures for water quality degradation ...and biodiversity decline in a multi-use watershed. The processes were soil erosion and wildfire risk; the pressures comprised land use conflicts, leachates from domestic and industrial waste, arable farming intensity and livestock density. Water quality was characterized for concentrations of nutrients (nitrate, phosphate), oxygen demands (Biochemical Oxygen Demand – BOD5, Chemical Oxygen Demand – COD) and various metals (e.g., As, Cr). Ecological integrity was assessed by the recently developed MELI (Multiple Ecological Level Index). In total, 18 variables were processed in the regression models. Two models were called “nested models” because they dealt with initial (pressures), intermediate (water quality) and final (MELI) environmental descriptors, used as dependent (MELI, quality) or independent (quality, pressures) variables. The third was called “bypass model” because it dealt solely with initial and final descriptors. Overall, the results of PLS regression linked the ineffective treatment of domestic sewage to water quality and ecological integrity declines in the studied watershed. Put another way, all models recurrently affirmed the major role of local factors, meaning of point source pollution, in determining the quality of stream water and the integrity of freshwater ecosystems. Sources of diffuse pollution were accounted for as contributing factors in the PLS regressions, but their influence was scarcely perceptible in the results. The poor treatment of domestic effluents is a public concern. In their strategic plans for mitigating this problem in the forthcoming years, administrative authorities are concentrated on management initiatives to improve the quality of provided services, instead of considering the construction of new wastewater treatment plants.
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•PLS regression and GIS were used to correlate spatial patterns of environmental descriptors in the Ave River basin (Portugal)•Results linked ecological integrity declines observed downstream to poor treatment of domestic sewage•The impact of industrial effluents and diffuse pollution sources are viewed as subsidiary•Local factors have a greater influence on the values of BOD5, COD, PO4, NO3 and Fe, than larger scale factors•Mitigation of urban pollution relies on the improvement of wastewater treatment and not on the construction of new plants
In this work, several benzothiazole-based aminosquaraine dyes, displaying strong absorption within the so-called phototherapeutic window (650⁻800 nm), were synthesized. The ability, of all the new ...dyes, to generate singlet oxygen was assessed by determining the correspondent phosphorescence emission and through the comparison with a standard. The quantum yields of singlet oxygen generation were determined and exhibited to be strongly dependent on the nature of the amino substituents introduced in the squaric ring. The photodynamic activity of the synthesized dyes was tested against four human tumor cell lines: breast (MCF-7), lung (NCI-H460), cervical (HeLa) and hepatocellular (HepG2) carcinomas; and a non-tumor porcine liver primary cell culture (PLP2). All the compounds synthesized were found to be able to inhibit tumor cells growth upon irradiation more than in the dark, in most of the cases, very significantly. Considering the photodynamic activity exhibited and the low toxicity displayed for the non-tumor cells, some of the synthetized dyes can be regarded as potential candidates as photosensitizers for PDT.
This is a systematic review about the association between empathic behavior and oxytocin (OXT). Searches were conducted in the electronic databases PubMed, Web of Science, PsycINFO, SciELO, and ...LILACS using the search terms “oxytocin”, “empathy”, and “empathic”. Forty-four studies were reviewed. Scarce findings point to a lack of association between baseline endogenous OXT levels and empathy traits, and for a trend towards a direct relationship between oxytocinergic reactivity and empathic functioning. The results showed that variations in empathy were related to polymorphisms in the OXT receptor gene, especially in rs53576, and that this relationship seems to mediated by individual, ethnic, and cultural characteristics. Most studies on the exogenous administration of OXT tested a single dose (24 IU) with positive effects mainly on the affective domain of empathy. At the neural level, findings were inconsistent. Taken together, the results of the studies reviewed support the existence of a relationship between OXT and empathy that is complex and multifaceted. Robust evidence is still needed to elucidate existing links. Future investigations could benefit from methodological improvements aimed at increasing the reproducibility and applicability of findings, as well as the systematic assessment of the effects of exogenous OXT considering dose and frequency of administration, genotyping, and hormonal availability at the peripheral and central levels. This should lead to significant progress in the understanding of the therapeutic possibilities of OXT in the domain of empathic behavior.
•Relationship between OXT and empathy is complex and multifaceted.•OXT is implicated in the neurobiology of empathic behavior.•Baseline OXT levels do not seem to be related with empathic behavior.•Variations in OXTR gene may contribute to explain the variability in prosocial behavior.•Effects of the exogenous administration of OXT are dependent on dimensions of empathy investigated.
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