Ανάπτυξη νέων σκουαραϊνικών παραγώγων με βιολογικό ενδιαφέρον

Τα υδατοδιαλυτά παράγωγα του σκουαραϊκού οξέος μπορούν να χρησιμοποιηθούν ως φωτοευαισθητοποιητές σε φωτοδυναμική θεραπεία και άλλες πιθανές βιολογικές εφαρμογές. Επίσης, βρίσκουν ποικίλες τεχνολογικές εφαρμογές και εφαρμογές στην επιστήμη υλικώνWater-soluble squaraine derivatives can be used as photosensitizers in photodynamic therapy and other possible biological applications. Moreover, they find many technological applications as well as applications in materials science

Lowering the operating temperature of gold acetylene hydrochlorination catalysts using oxidized carbon supports

The commercialization of gold for acetylene hydrochlorination represents a major scientific landmark. The development of second-generation gold catalysts continues with a focus on derivatives and drop-in replacements with higher activity and stability. Here, we show the influence that the support surface oxygen has on the activity of carbon supported gold catalysts. Variation in the surface oxygen content of carbon is achieved through careful modification of the Hummers chemical oxidation method prior to the deposition of gold. All oxidized carbon-based catalysts resulted in a marked increase in activity at 200 °C when compared to the standard nontreated carbon, with an optimum oxygen content of ca. 18 at % being observed. Increasing oxygen and relative concentration of C–O functionality yields catalysts with light-off temperatures 30–50 °C below the standard catalyst. This understanding opens a promising avenue to produce high activity acetylene hydrochlorination catalysts that can operate at lower temperatures

Sulfur promotion in Au/C catalyzed acetylene hydrochlorination

The formation of highly active and stable acetylene hydrochlorination catalysts is of great industrial importance. The successful replacement of the highly toxic mercuric chloride catalyst with gold has led to a flurry of research in this area. One key aspect, which led to the commercialization of the gold catalyst is the use of thiosulphate as a stabilizing ligand. This study investigates the use of a range of sulfur containing compounds as promoters for production of highly active Au/C catalysts. Promotion is observed across a range of metal sulfates, non‐metal sulfates, and sulfuric acid treatments. This observed enhancement can be optimized by careful consideration of either pre‐ or post‐treatments, concentration of dopants used, and modification of washing steps. Pre‐treatment of the carbon support with sulfuric acid (0.76 m) resulted in the most active Au/C in this series with an acetylene conversion of ≈70% at 200 °C

Drug Survival of Interleukin (IL)‑17 and IL‑23 Inhibitors for the Treatment of Psoriasis: A Retrospective Multi‑country, Multicentric Cohort Study

Background: Drug survival, defined as the length of time from initiation to discontinuation of a given therapy, allows comparisons between drugs, helps to predict patient's likelihood of remaining on a specific treatment, and achieving the best decision for each patient in daily clinical practice. Objective: The aim of this study was to provide data on drug survival of secukinumab, ixekizumab, brodalumab, guselkumab, tildrakizumab, and risankizumab in a large international cohort, and to identify clinical predictors that might have an impact on the drug survival of these drugs. Methods: This was a retrospective, multicentric, multi-country study that provides data of adult patients with moderate to severe psoriasis who started treatment with an interleukin (IL)-17 or IL-23 inhibitor between 1 February 2015 and 31 October 2021. Data were collected from 19 distinct hospital and non-hospital-based dermatology centers from Canada, Czech Republic, Italy, Greece, Portugal, Spain, and Switzerland. Kaplan-Meier estimator and proportional hazard Cox regression models were used for drug survival analysis. Results: A total of 4866 treatment courses (4178 patients)-overall time of exposure of 9500 patient-years-were included in this study, with 3164 corresponding to an IL-17 inhibitor (secukinumab, ixekizumab, brodalumab) and 1702 corresponding to an IL-23 inhibitor (guselkumab, risankizumab, tildrakizumab). IL-23 inhibitors had the highest drug survival rates during the entire study period. After 24 months of treatment, the cumulative probabilities of drug survival were 0.92 (95% confidence interval [CI] 0.89-0.95) for risankizumab, 0.90 (95% CI 0.88-0.92) for guselkumab, 0.80 (95% CI 0.76-0.84) for brodalumab, 0.79 (95% CI 0.76-0.82) for ixekizumab, and 0.75 (95% CI 0.73-0.77) for secukinumab. At 36 months, only guselkumab [0.88 (95% CI 0.85-0.91)], ixekizumab [0.73 (95% CI 0.70-0.76)], and secukinumab [0.67 (95% CI 0.65-0.70)] had more than 40 patients at risk of drug discontinuation. Only two drugs had more than 40 patients at risk of drug discontinuation at 48 months, with ixekizumab demonstrating to have a higher cumulative probability of drug survival [0.71 (95% CI 0.68-0.75)] when compared with secukinumab [0.63 (95% CI 0.60-0.66)]. Secondary failure was the main cause for drug discontinuation. According to the final multivariable model, patients receiving risankizumab, guselkumab, and ixekizumab were significantly less likely to discontinue treatment than those receiving secukinumab. Previous exposure to biologic agents, absent family history of psoriasis, higher baseline body mass index (BMI), and higher baseline Psoriasis Area and Severity Index (PASI) were identified as predictors of drug discontinuation. Conclusion: The cumulative probability of drug survival of both IL-17 and IL-23 inhibitors was higher than 75% at 24 months, with risankizumab and guselkumab demonstrating to have overall cumulative probabilities ≥ 90%. Biological agent chosen, prior exposure to biologic agents, higher baseline BMI and PASI values, and absence of family history of psoriasis were identified as predictors for drug discontinuation. Risankizumab, guselkumab, and ixekizumab were less likely to be discontinued than secukinumab

Acetylene hydrochlorination using Au supported on activated carbon catalysts

Acetylene hydrochlorination is a major industrial method to produce vinyl chloride monomer (VCM). Traditionally, the manufacture of VCM relied on the use of a HgCl2/C catalyst, posing serious environmental concerns due to the loss of toxic Hg species from the surface of the support to the environment. Consequently, there has been an urgent need for the development of novel, environmentally friendly replacement catalysts. Chapter 3: In the first part of the thesis, a general approach to identify the best catalyst for the acetylene hydrochlorination reaction using a data set of key performance indicators has been introduced. The proposed universal method allows a direct comparison among metal and metal-free catalysts and demonstrates that Au-based catalysts are the best-in-class materials for this particular reaction. Chapter 4: This part of the study is focused on identifying the structure-activity relationship of the carbon support, and therefore a sequence of characterizations studies was performed. The physical and chemical properties of the carbonaceous materials, such as the texture, porosity, surface graphitization, surface functional groups, and surface acidic sites distribution were analysed. The results illustrated that the higher activity is associated with high porosity, high graphitization degree and low surface acidic groups. This work aims to illustrate a rationalized set of criteria for support evaluation and development. Chapter 5: In this study the effect that N-methyl-2-pyrrolidone (NMP) has on improving the activity and the stability of Au-based catalysts has been thoroughly investigated. Using a simple wet impregnation method, a 1 wt.% Au- NMP catalyst has been prepared. The study showed that the Au-NMP catalyst displays higher activity when tested at different temperatures in comparison to the standard catalyst, while it also exhibits a greater performance when compared to the commercial catalyst as validated at Johnson Matthey. Characterisation of the Au-NMP complex, including single crystal diffraction, Raman, IR spectroscopy and NMR, confirmed the coordination of the NMP to the Au centre via the N moiety, while it was identified that the structure of Au-NMP is a salt complex with a 1:2 ratio respectively. Finally, a series of NMP derivatives were used for the preparation of 1 wt.% Au-NMP(derivatives) illustrating that the co-existence of O and N is of a great importance for the high activity of the catalyst, as seen from the comparison of NMP with analogous structures

Mathematics Education Out in the Rural Scape : Experimenting With Radical Democracy for Commons

The purpose of this paper is to discuss a pedagogic experimentation in the rural scape at a Greek village that tends to challenge the neoliberal and capitalist politics of economic austerity in the area. A group of young educated people in their 30s instead of migrating to the ‘West’ for a secure job have opted to return at their place of origin for a way of living around the values of a common ownership economy. They experiment with a vision of radical democratic pedagogy as vital for life. It unfolds in their relations, first with children as part of an after-school workshop and second with the adults in varied interactions as part of sharing knowledge for manual work in the land and with hand-made constructions. As such mathematical ideas, skills and competences are being entangled in diverse opportunities of life reorganisation around what they perceive as their commons

Mathematics Education Out in the Rural Scape : Experimenting With Radical Democracy for Commons

The purpose of this paper is to discuss a pedagogic experimentation in the rural scape at a Greek village that tends to challenge the neoliberal and capitalist politics of economic austerity in the area. A group of young educated people in their 30s instead of migrating to the ‘West’ for a secure job have opted to return at their place of origin for a way of living around the values of a common ownership economy. They experiment with a vision of radical democratic pedagogy as vital for life. It unfolds in their relations, first with children as part of an after-school workshop and second with the adults in varied interactions as part of sharing knowledge for manual work in the land and with hand-made constructions. As such mathematical ideas, skills and competences are being entangled in diverse opportunities of life reorganisation around what they perceive as their commons

Mathematics Education Out in the Rural Scape : Experimenting With Radical Democracy for Commons

The purpose of this paper is to discuss a pedagogic experimentation in the rural scape at a Greek village that tends to challenge the neoliberal and capitalist politics of economic austerity in the area. A group of young educated people in their 30s instead of migrating to the ‘West’ for a secure job have opted to return at their place of origin for a way of living around the values of a common ownership economy. They experiment with a vision of radical democratic pedagogy as vital for life. It unfolds in their relations, first with children as part of an after-school workshop and second with the adults in varied interactions as part of sharing knowledge for manual work in the land and with hand-made constructions. As such mathematical ideas, skills and competences are being entangled in diverse opportunities of life reorganisation around what they perceive as their commons