New three-dimensional poly(decanediol-co-tricarballylate) elastomeric fibrous mesh fabricated by photoreactive electrospinning for cardiac tissue engineering applications

Reactive electrospinning is capable of efficiently producing in situ crosslinked scaffolds resembling the natural extracellular matrix with tunable characteristics. In this study, we aimed to synthesize, characterize, and investigate the in vitro cytocompatibility of electrospun fibers of acrylated poly(1,10-decanediol-co-tricarballylate) copolymer prepared utilizing the photoreactive electrospinning process with ultraviolet radiation for crosslinking, to be used for cardiac tissue engineering applications. Chemical, thermal, and morphological characterization confirmed the successful synthesis of the polymer used for production of the electrospun fibrous scaffolds with more than 70% porosity. Mechanical testing confirmed the elastomeric nature of the fibers required to withstand cardiac contraction and relaxation. The cell viability assay showed no significant cytotoxicity of the fibers on cultured cardiomyoblasts and the cell-scaffolds interaction study showed a significant increase in cell attachment and growth on the electrospun fibers compared to the reference. This data suggests that the newly synthesized fibrous scaffold constitutes a promising candidate for cardiac tissue engineering applications. - 2018 by the authors.We would like to thank Fatima Mraiche for supplying the H9C2 cardiomyoblasts and Nabeel Abdulrahman for his support in the fluorescent imaging. The support of Qatar University Central Lab Unit team led by Saeed Al-Meer is highly appreciated. We acknowledge Michelle Somerville at the University of Bristol for her help with tissue culture studies.Scopu

The Bridging Language between Diglossia of Classical and Colloquial Arabic/ اللغة التجسيرية بين ازدواجية الفصحى والعامية

استهدف البحث الحالي تحديد أسباب الازدواجية، مثل: الأمية، وحصر القراءة والكتابة على النخبة، وتشكيل نمط لغوي يمثل الاستقلال والسيادة، وكذلك حصر أهم مشكلات الازدواجية، مثل: ضياع الهوية، وانقراض الفصحى، والتفكك الاجتماعي؛ مما كان سببا في ضرورة إيجاد لغة تجسيرية تقرب الفجوة بين: العامية، والفصحى، مع تحديد ملامح هذه اللغة التجسيرية، وآليات بناء المناهج وإعداد المواد التعليمية واللغوية في ضوء نموذج رباعي للغة التجسيرية اقترحه البحث الحالي؛ بما يساعد على بناء مناهج للغة العربية تقرب بين: العامية، والفصحى، ومن أهم نتائج الدراسة الحالية: أن اللغة التجسيرية تساعد على سهولة تعلم اللغة العربية وعدم شعور المتعلم بالغربة والانفصام اللغوي، كما توصلت الدراسة إلى إمكانية وضع تصور مقترح لبناء مناهج اللغة العربية في ضوء معطيات لغة تجسيرية شائعة ومألوفة على الآذان تسد الفجوة ما بين العامية والفصحى. The current research aims at identifying the causes of diglossia, such as: illiteracy, limited reading culture and writing for the elite, and forming a language pattern that represents independence and sovereignty. In addition, this research identifies the primary issues of this bridging language, and to find linguistic and social mechanisms for diglossia, such as: loss of identity, classical language extinction, and social disintegration; which leads to generate a bridging language, which closes the gap between: colloquial and classical Arabic, to highlight specific features of building and preparing educational curricula and linguistic materials In the paradigm of a quadruple model flow of the bridging language proposed by this research; to help approximate between classical and colloquial Arabic. Among the most important results of this study: that the bridging language helps to learn, reinforce linguistic and communication retainment and prevent the Arabic language deterioration, The Bridging language evades learner and user sense of alienation, and linguistic schizophrenia. The study also finds the possibility of developing a proposed concept for building Arabic language curricula in light of common and familiar bridging language data which is common and familiar that bridges the gap between colloquial and classical Arabic

Magnetar-like X-Ray Bursts from a Rotation-powered Pulsar, PSR J1119-6127

Two energetic hard X-ray bursts have recently triggered the Fermi and Swift space observatories from the rotation powered pulsar, PSR J1119-6127. We have performed in depth spectral and temporal analyses of these two events. Our extensive searches in both observatory data for lower luminosity bursts uncovered 10 additional events from the source. We report here on the timing and energetics of the 12 bursts from PSR J1119-6127 during its burst active phase of 2016 July 26 and 28. We also found a spectral softer X-ray flux enhancement in a post burst episode, which shows evidence of cooling. We discuss here the implications of these results on the nature of this unusual high-field radio pulsar, which firmly place it within the typical magnetar population.Comment: Revised version, accepted for publication in ApJL. An expanded version of Table 1, as well as the light curves of all Fermi/GBM detected bursts can be found at http://magnetars.sabanciuniv.edu/psrj1119.ph

Complementary approaches to understanding the plant circadian clock

Circadian clocks are oscillatory genetic networks that help organisms adapt to the 24-hour day/night cycle. The clock of the green alga Ostreococcus tauri is the simplest plant clock discovered so far. Its many advantages as an experimental system facilitate the testing of computational predictions. We present a model of the Ostreococcus clock in the stochastic process algebra Bio-PEPA and exploit its mapping to different analysis techniques, such as ordinary differential equations, stochastic simulation algorithms and model-checking. The small number of molecules reported for this system tests the limits of the continuous approximation underlying differential equations. We investigate the difference between continuous-deterministic and discrete-stochastic approaches. Stochastic simulation and model-checking allow us to formulate new hypotheses on the system behaviour, such as the presence of self-sustained oscillations in single cells under constant light conditions. We investigate how to model the timing of dawn and dusk in the context of model-checking, which we use to compute how the probability distributions of key biochemical species change over time. These show that the relative variation in expression level is smallest at the time of peak expression, making peak time an optimal experimental phase marker. Building on these analyses, we use approaches from evolutionary systems biology to investigate how changes in the rate of mRNA degradation impacts the phase of a key protein likely to affect fitness. We explore how robust this circadian clock is towards such potential mutational changes in its underlying biochemistry. Our work shows that multiple approaches lead to a more complete understanding of the clock

Orange Pectin Mediated Growth and Stability of Aqueous Gold and Silver Nanocolloids

International audienceThe role of orange based pectin in the nucleation and growth of silver and gold nanoparticles is addressed. Pectin is a complex polysaccharide found in fruits such as oranges, lemons, passion fruits or apples. It displays smooth and hairy chain regions contg. hydroxyl-​, ester-​, carboxylate- and eventually amine groups that can act as surface ligands interacting under various pH conditions more or less efficiently with growing nanometals. Here, a high methoxy pectin (>50​% esterified) was used as a stabilizer​/reducing agent in the prepn. of gold, silver and silver-​gold nanoparticles. Com. pectin (CP) and pectin extd. from orange bagasse (OP) were used. Optionally, trisodium citrate or oxalic acid we used to reduce AgNO3 and HAuCl4 in aq. environment. Characterization methods included UV-​vis absorption spectroscopy, transmission electron microscopy, electron diffraction and energy-​dispersive X-​ray spectroscopy. The results show that under different pH conditions, pectin and reducing agents allow producing various nanostructures shapes (triangles, spheres, rods, octahedrons and decahedrons) often with high polydispersity and sizes ranging between 5 nm and 30 nm. In addn., depending on Ag​/Au-​ratio and pH, the surface plasmon bands can be continuously shifted between 410 nm and 600 nm. Finally, pectin seems to be a highly efficient stabilizer of the colloidal systems that show a remarkable stability and unchanged optical spectral response even after five years

Onset of collectivity in neutron deficient Po196,198

We have studied via in-beam -ray spectroscopy Po196 and Po198, which are the first neutron-deficient Po isotopes to exhibit a collective low-lying structure. The ratios of yrast state energies and the E2 branching ratios of transitions from non-yrast to yrast states are indicative of a low-lying vibrational structure. The onset of collective motion in these isotopes can be attributed to the opening of the neutron i13/2 orbital at N112 and the resulting large overlap between the two valence protons in the h9/2 orbital and the valence neutrons in the i13/2 orbital

EPIdemiology of Surgery-Associated Acute Kidney Injury (EPIS-AKI) : Study protocol for a multicentre, observational trial

More than 300 million surgical procedures are performed each year. Acute kidney injury (AKI) is a common complication after major surgery and is associated with adverse short-term and long-term outcomes. However, there is a large variation in the incidence of reported AKI rates. The establishment of an accurate epidemiology of surgery-associated AKI is important for healthcare policy, quality initiatives, clinical trials, as well as for improving guidelines. The objective of the Epidemiology of Surgery-associated Acute Kidney Injury (EPIS-AKI) trial is to prospectively evaluate the epidemiology of AKI after major surgery using the latest Kidney Disease: Improving Global Outcomes (KDIGO) consensus definition of AKI. EPIS-AKI is an international prospective, observational, multicentre cohort study including 10 000 patients undergoing major surgery who are subsequently admitted to the ICU or a similar high dependency unit. The primary endpoint is the incidence of AKI within 72 hours after surgery according to the KDIGO criteria. Secondary endpoints include use of renal replacement therapy (RRT), mortality during ICU and hospital stay, length of ICU and hospital stay and major adverse kidney events (combined endpoint consisting of persistent renal dysfunction, RRT and mortality) at day 90. Further, we will evaluate preoperative and intraoperative risk factors affecting the incidence of postoperative AKI. In an add-on analysis, we will assess urinary biomarkers for early detection of AKI. EPIS-AKI has been approved by the leading Ethics Committee of the Medical Council North Rhine-Westphalia, of the Westphalian Wilhelms-University Münster and the corresponding Ethics Committee at each participating site. Results will be disseminated widely and published in peer-reviewed journals, presented at conferences and used to design further AKI-related trials. Trial registration number NCT04165369