Synthesis and photophysical characterization of novel triphenylamine-benzimidazole derivatives

Research on organic luminescent materials has been intensely pursued due to their importance in technological applications related to signaling, fluorescent biosensory/chemosensory materials, molecular switches and organic light emitting diodes (OLEDs). Organic fluorophores such as triphenylamine and benzimidazole derivatives have attracted a particular attention owing to their high emission efficiency being widely used as electron transporters and emitting layers for OLEDs.1 Recently, we have been investigating the potential of heterocyclic systems bearing functionalized (benz)imidazole derivatives exhibiting high thermal stability, interesting emissive and chemosensory properties.2 In this communication we report the synthesis and photophysical characterization of triphenylamine-benzimidazoles (compounds 1a-d) which were synthesized by a one step reaction through the Na2S2O4 reduction of several commercially available o-nitroanilines in the presence of triphenylamine aldehyde in DMSO at 120 °C. Compounds 1a-d bear different functionalization at position 5 of the benzimidazole with electron-donor or acceptor groups (Figure 1). A comprehensive spectral and photophysical investigation of these compounds including absorption, fluorescence and triplet-triplet absorption spectra, together with quantum yields of fluorescence, internal conversion, intersystem crossing and singlet oxygen and rate constants for the radiative and radiationless processes has been undertaken in solution at room temperature. It is shown that compounds 1a-d exhibit high fluorescence quantum yields (0.70-0.78). Additionally, a comparison between the optical and photophysical properties of 1a-d will be also presented and discussed.Fundação para a Ciência e a Tecnologia (FCT

Synthesis and characterization of the ground and excited states of tripodal-like oligothienyl-imidazoles

Six new thiophene oligomers, here designated as tripodal-like oligothienyl imidazoles, were synthesized and have been investigated in ethanol solution at room and low temperature. The oligomers bear a common core where two or more thiophenes are linked to one or more imidazole unit which further links through its alpha position to a different number of incremental thiophene units. The study involves a comprehensive spectral and photophysical investigation where the properties of the singlet and triplet states have been investigated regarding absorption, fluorescence and phosphorescence, transient triplet-triplet absorption together with all relevant quantum yields (fluorescence, internal conversion, intersystem crossing and singlet oxygen) and lifetimes. In addition, DFT quantum chemical calculations were performed to gain a detailed understanding of the molecular geometry and optical properties of the investigated oligomers. From the overall data, the radiative (kF) and radiationless (kNR, kIC and kISC) rate constants have been determined and it is shown that, in contrast with the parent oligothiophenes, the radiative competes with the radiationless deactivation channels. The results show that, by comparison with the oligothiophene counterparts, there is an augment of the relative contributions of the internal conversion and fluorescence processes relative to the S1~~T1 intersystem crossing. Phosphosphorescence emission was found for the simplest member of the investigated compounds, with a low quantum yield and a lifetime of 8 picos. The data also show that the introduction of a 4,5-dithienyl-imidazole moiety in a bi- or terthiophene oligomer results in, respectively, a 20-fold and a 3-fold increase of the fluorescence quantum yield relative to their oligothiophene counterparts.Fundação para a Ciência e a Tecnologia (FCT

The influence of the relative position of the thiophene and pyrrole rings in donor-acceptor thienylpyrrolyl benzothiazole derivatives. A photophysical and theoretical investigation

A detailed spectroscopic and photophysical study has been carried out on a series of heterocyclic compounds -known to display nonlinear optical properties- consisting on one electron donating thienylpyrrolyl π-conjugated system functionalized with an electron acceptor benzothiazole moiety. The absorption, emission and triplet-triplet absorption together with all relevant quantum yields (fluorescence, intersystem crossing and internal conversion), excited state lifetimes and the overall set of deactivation rate constants (kF, kIC and kISC) were obtained in solution at room (293 K) and low (77 K) temperature. The optimized ground-state molecular geometries for the compounds together with the prediction of the lowest vertical one-electron excitation energy and the relevant molecular orbital contours for the compounds were also determined using the density functional theory (DFT) at the B3LYP/3 21G* level. The experimental results showed that the photophysical properties are influenced by the relative position of the pyrrole and thiophene relative to the benzothiazole groups.Fundação para a Ciência e a Tecnologia (FCT

The impact of shift work on burnout syndrome, depression, anxiety and stress: A case study in the metalworking industry

Shift work has been linked to health disorders, decreases in workers’ safety and productivity, and poor family and social relationships. However, the relationship between this type of work and the incidence of psychosocial health disorders is not yet well characterized. This study aims to analyse the impact of the shift work in the prevalence of the burnout syndrome, anxiety, depression and stress. A total of 175 workers from the production sector of a metalworking industry, operating in three different shifts (morning, afternoon and night), participated in the study. The burnout syndrome was assessed with the Shirom-Melamed Burnout Measure and the anxiety, depression and stress were measured through the Depression Anxiety Stress Scales (DASS). The obtained levels of burnout syndrome and stress were low, while anxiety and depression exhibited higher levels. Contrary to what was expected, the morning shift presented higher levels of psychosocial health disorders. However, no significant differences were found between the three shifts. These results can be explained by several factors such as the workers’ age, years of work in the shift work and the existence of a second job.info:eu-repo/semantics/publishedVersio

Uloga prirodnih spojeva kod raka mliječnih žlijezda u štakora; blagotvorni učinci vodenog ekstrakta Santolina chamaecyparissus L.

Breast cancer is the most diagnosed cancer among women, and a leading cause of death worldwide. Santolina chamaecyparissus L. is a plant with multiple health benefits, including anticancer and anti-diabetic properties. This study aimed to assess the chemopreventive effects of S. chamaecyparissus aqueous extract (SCE) in an animal model of mammary cancer. A total of 28 four-week-old female Wistar rats were divided into four groups: control, MNU-induced (IND), SCE-supplemented (SCE), and SCE+IND. SCE was added to drinking water (12.72 mg/kg body weight) ad libitum. MNU was administered via the intraperitoneal route at 50 days of age. Weekly monitoring of body weight, food/drink intake, humane endpoints, and number of mammary tumours were recorded. Twenty weeks after MNU administration, animals were sacrificed by anaesthetic overdose and a necropsy was performed. Blood samples were used to determine blood count and serum biochemistry analysis, while kidney and liver samples were analysed for oxidative stress. Tumour samples were collected for gene expression and histology studies. SCE chemical composition was analysed by LC-MS and contained 19 phenolic compounds, with the most abundant being myricetin-O-glucuronide and 1,3-O-dicaffeoylquinic acid. Two animals in the IND group were sacrificed due to exceeding the humane endpoint limits. SCE supplementation delayed mammary tumour development, reducing its volume and weight. SCE had a positive impact on haematological parameters, particularly the neutrophil-lymphocyte ratio (P=0.026). No significant differences were observed in serum biochemistry, except for creatinine kinase MB, or in oxidative stress markers. Gene expression analysis showed significantly reduced VEGF expression levels (P=0.0158) in tumours from SCE+IND. These findings suggest that SCE is deserving of further study to identify the individual compounds and to understand its influence on animal models during cancer development.Rak dojke najčešće je dijagnosticiran rak u žena i vodeći uzrok smrti na svijetu. Santolina chamaecyparissus L. je biljka s višestrukim blagotvornim učincima za zdravlje, uključujući antitumorska i antidijabetička svojstva. Cilj je ove studije bio procijeniti kemopreventivne učinke vodenog ekstrakta S. chamaecyparissus (SCE) na životinjama obeljelim od raka mliječnih žlijezda. Dvadeset i osam četiri ženki starih tjedna wistar štakora podijeljeno je u četiri skupine: kontrolnu, MNU-inducirano (IND), s dodatkom SCE (SCE) i SCE+IND. Skupini SCE je dodan vodi za piće (12,72 mg/kg tjelesne mase) ad libitum; MNU je primijenjen intraperitonealnim putem u 50. danu života. Tjedno je bilježeno praćenje tjelesne mase, unosa hrane/tekućine, humano usmrćivanje i broj tumora mliječnih žlijezda. Dvadeset tjedana nakon primjene MNU, životinje su žrtvovane predoziranjem anestetikom i obavljena je razudba. Uzorci krvi su rabljeni za određivanje krvne slike i analizu biokemije seruma, dok su uzeti uzorci bubrega i pluća rabljeni za analize oksidativnog stresa. Uzorci tumora su prikupljeni za studije ekspresije gena i histološke studije. Analiziran je kemijski sastav skupine SCE pomoću LC-MS i otkriveno je da sadrži 19 fenolnih spojeva od kojih su najobilniji bili miricetin-O-glukuronid i 1,3-O-dikafeoilkina kiselina. Dvije životinje iz IND skupini žrtvovane su zbog prekoračenja ograničenja za humano usmrćivanje. Skupini SCE dodatak je odgodio razvoj tumora mliječnih žlijezda, smanjujući njegov volumen i masu. Skupina SCE je imala pozitivni učinak na hematološke parametre, posebice na omjer neutrofila i limfocita (P=0,026). Nikakve značajne razlike nisu otkrivene u biokemiji seruma, osim kreatinin kinaze MB, niti u markerima oksidativnog stresa. Analiza ekspresije gena pokazala je značajno smanjene razina ekspresije VEGF (P=0,0158) u tumora iz skupine SCE+IND. Ovi nalazi ukazuju da bi skupinu SCE trebalo dodatno ispitati da bi se identificirali pojedinačni spojevi i razumio njegov utjecaj na životinjama oboljelih od raka mliječnih žlijezda

The future of cephalopod populations, fisheries, culture, and research in Europe

International audienc

Cartilha sobre conta vinculada

Orientações básicas sobre a operacionalização da Conta Vinculada nos termos do art. 19-A e Anexo VII da Instrução Normativa SLTI/MP nº 2, de 30 de abril de 2008, com alterações posteriores

Psychosocial impact of undergoing prostate cancer screening for men with BRCA1 or BRCA2 mutations.

OBJECTIVES: To report the baseline results of a longitudinal psychosocial study that forms part of the IMPACT study, a multi-national investigation of targeted prostate cancer (PCa) screening among men with a known pathogenic germline mutation in the BRCA1 or BRCA2 genes. PARTICPANTS AND METHODS: Men enrolled in the IMPACT study were invited to complete a questionnaire at collaborating sites prior to each annual screening visit. The questionnaire included sociodemographic characteristics and the following measures: the Hospital Anxiety and Depression Scale (HADS), Impact of Event Scale (IES), 36-item short-form health survey (SF-36), Memorial Anxiety Scale for Prostate Cancer, Cancer Worry Scale-Revised, risk perception and knowledge. The results of the baseline questionnaire are presented. RESULTS: A total of 432 men completed questionnaires: 98 and 160 had mutations in BRCA1 and BRCA2 genes, respectively, and 174 were controls (familial mutation negative). Participants' perception of PCa risk was influenced by genetic status. Knowledge levels were high and unrelated to genetic status. Mean scores for the HADS and SF-36 were within reported general population norms and mean IES scores were within normal range. IES mean intrusion and avoidance scores were significantly higher in BRCA1/BRCA2 carriers than in controls and were higher in men with increased PCa risk perception. At the multivariate level, risk perception contributed more significantly to variance in IES scores than genetic status. CONCLUSION: This is the first study to report the psychosocial profile of men with BRCA1/BRCA2 mutations undergoing PCa screening. No clinically concerning levels of general or cancer-specific distress or poor quality of life were detected in the cohort as a whole. A small subset of participants reported higher levels of distress, suggesting the need for healthcare professionals offering PCa screening to identify these risk factors and offer additional information and support to men seeking PCa screening

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements