Tuning of the luminescence in poly((silanylene)thiophene)s

Synthetic routes to alternating copolymers consisting of oligosilylene blocks and oligothiophene blocks (T-x; x = 1, 2, 3, 4, or 6 rings) are presented. Solubility requirements for obtaining acceptable molecular weights and, eventually, for film formation are met by the introduction of butyl groups replacing methyls on the silicon atoms and by employing T-6 blocks carrying two octyl substituents. Additionally, substituted oligothiophenes are synthesized as an aid in the interpretation of NMR, absorption, and fluorescence spectra. Regarding the electronic configuration of the oligothiophene blocks, NMR spectra show clear differences between plain oligothiophenes, end-substituted oligothiophenes, and polymers, indicative of pi-sigma interactions with the oligosilylene blocks and possible through-conjugation to adjacent blocks in polymers. Red shifts in optical spectra show a parallel trend across the various compounds based on the same oligothiophene unit, related to the stabilization of photoexcited states on the oligothiophene by the oligosilylene substituents. These effects are strong in T-2-based compounds and reduced fdr longer T-n. The main feature of the spectra is the decrease of the transition energies with the size of the oligothiophene blocks in the polymers. Since this effect is also found in fluorescence, it enables one to adjust the luminescence wavelength by choosing the proper block length (''chemical tuning''). Fluorescence quantum efficiencies in solution are found to be remarkably high in polymers based on T-2 blocks. Spin-coated films of T-2-based (or T-3-based) polymers show evidence of T-4 (T-6) impurity blocks that act as an exciton trap

The influence of different intermittent myofeedback training schedules on learning relaxation of the trapezius muscle while performing a gross-motor task

The aim of this study was to investigate the influence of different intermittent myofeedback training schedules, as provided by a Cinderella-based myofeedback system, on learning relaxation and resistance to extinction of the trapezius muscle, in subjects performing a unilateral gross-motor task. Eighteen healthy subjects performed the task without and with feedback to study baseline and learning relaxation. Subsequently, resistance to extinction was investigated by performing the task without feedback. The gross-motor task consisted of continuously moving the dominant arm between three target areas at a constant pace. Subjects were randomly assigned into three groups, characterized by the sequence of feedback schedules with which the task was performed on 3 consecutive days. Auditory feedback was provided after a 5-, 10-, or 20-s interval when a pre-set level of 80% rest was not reached. Bipolar surface electromyography recordings performed at the dominant upper trapezius muscle were quantified using relative rest time (RRT) and root mean square (RMS) parameters. Learning relaxation was defined as an increase in RRT and a decrease in RMS values. Results showed the highest RRT levels as well as a decrease in RMS for the 10-s schedule. Additionally, the 10-s schedule was unique in its ability to elevate muscular rest above the 20% level, which may be considered relevant in preventing myalgia. None of the three schedules showed resistance to extinction. It was concluded that the 10-s interval was preferred over the 5- and 20-s schedules in learning trapezius relaxation in subjects performing a unilateral gross-motor task

Pregnancy outcomes in women with Budd-Chiari syndrome or portal vein thrombosis A multicentre retrospective cohort study

OBJECTIVE: To evaluate current practice and outcomes of pregnancy in women previously diagnosed with Budd-Chiari syndrome and/or portal vein thrombosis, with and without concomitant portal hypertension. DESIGN AND SETTING: Multicentre retrospective cohort study between 2008-2021. POPULATION: Women who conceived in the predefined period after the diagnosis of Budd-Chiari syndrome and/or portal vein thrombosis. METHODS AND MAIN OUTCOME MEASURES: We collected data on diagnosis and clinical features. The primary outcomes were maternal mortality and live birth rate. Secondary outcomes included maternal, neonatal and obstetric complications. RESULTS: Forty-five women (12 Budd-Chiari syndrome, 33 portal vein thrombosis; 76 pregnancies) were included. Underlying prothrombotic disorders were present in 23 of 45 women (51%). Thirty-eight women (84%) received low-molecular-weight heparin during pregnancy. Of 45 first pregnancies, 11 (24%) ended in pregnancy loss and 34 (76%) resulted in live birth of which 27 at term age (79% of live births and 60% of pregnancies). No maternal deaths were observed, one woman developed pulmonary embolism during pregnancy and two women (4%) had variceal bleeding requiring intervention. CONCLUSIONS: The high number of term live births (79%) and lower than expected risk of pregnancy-related maternal and neonatal morbidity in our cohort suggest that Budd-Chiari syndrome and/or portal vein thrombosis should not be considered as an absolute contra-indication for pregnancy. Individualized, nuanced counselling and a multidisciplinary pregnancy surveillance approach are essential in this patient population

Discovery of very-high-energy emission from RGB J2243+203 and derivation of its redshift upper limit

Very-high-energy (VHE; $>$ 100 GeV) gamma-ray emission from the blazar RGB J2243+203 was discovered with the VERITAS Cherenkov telescope array, during the period between 21 and 24 December 2014. The VERITAS energy spectrum from this source can be fit by a power law with a photon index of $4.6 \pm 0.5$, and a flux normalization at 0.15 TeV of $(6.3 \pm 1.1) \times 10^{-10} ~ \textrm{cm}^{-2} \textrm{s}^{-1} \textrm{TeV}^{-1}$. The integrated \textit{Fermi}-LAT flux from 1 GeV to 100 GeV during the VERITAS detection is $(4.1 \pm 0.8) \times 10^{\textrm{-8}} ~\textrm{cm}^{\textrm{-2}}\textrm{s}^{\textrm{-1}}$, which is an order of magnitude larger than the four-year-averaged flux in the same energy range reported in the 3FGL catalog, ($4.0 \pm 0.1 \times 10^{\textrm{-9}} ~ \textrm{cm}^{\textrm{-2}}\textrm{s}^{\textrm{-1}}$). The detection with VERITAS triggered observations in the X-ray band with the \textit{Swift}-XRT. However, due to scheduling constraints \textit{Swift}-XRT observations were performed 67 hours after the VERITAS detection, not simultaneous with the VERITAS observations. The observed X-ray energy spectrum between 2 keV and 10 keV can be fitted with a power-law with a spectral index of $2.7 \pm 0.2$, and the integrated photon flux in the same energy band is $(3.6 \pm 0.6) \times 10^{-13} ~\textrm{cm}^{-2} \textrm{s}^{-1}$. EBL model-dependent upper limits of the blazar redshift have been derived. Depending on the EBL model used, the upper limit varies in the range from z $<~0.9$ to z $<~1.1$

ABA triblock copolymers: from controlled synthesis to controlled function

The ABA amphiphilic block copolymers, poly(hydroxyethyl methacrylate-hlock-methylphenylsilane-block-hydroxyethyl methacrylate) (PHEMA-PMPS-PHEMA) and poly[oligo(ethylene glycol) methyl ether methacrylate-block-methylphenylsilane-block-oligo(ethylene glycol). methyl ether methacrylate] (POEGMA-PMPS-POEGMA) were successfully synthesised via atom transfer radical polymerisation (ATRP). Macroinitiators suitable for the ATRP of oligo(ethylene glycol) methyl ether methacrylate and 2-hydroxyethyl methacrylate were synthesised from the condensation reaction of alpha,omega-dihalopolymethylphenylsilane and 2'-hydroxyethyl 2-bromo-2-methylpropanoate. The copolymers were characterised using H-1 NMR and C-13 NMR spectroscopy and molecular weight characteristics were determined using size exclusion chromatography and H-1 NMR. The aggregation behaviour of some of the copolymers in water was studied using transmission and scanning electron microscopy and dynamic light scattering. These revealed the prevalent aggregate species to be micelles. Larger aggregates of 300-1000 nm diameter were also observed. The UV induced degradation of the aggregates was studied by UV-Vis spectroscopy. The thermal behaviour of selected copolymers was studied by differential scanning calorimetry and microphase separation of the two components was demonstrated