Crystal structure of the stereoregular ethylene-alt-styrene copolymer synthesized with a zirconocene-based catalyst

A stereoregular alternating ethylene-styrene copolymer, also stretchable in fiber form, has been obtained with rac-isopropylidenebis( l-indenyl)zirconium dimethyldiamide activated by the methylalumoxane catalytic system. From X-ray diffraction fiber spectra, an isotactic structure has been assigned to this copolymer as well as the previously described stereoregular ethylene-styrene copolymers. The polymer has zigzag planar chain conformation with phenyl groups oriented perpendicularly to the chain axis. The crystallographic symmetry in B2/m. Lattice constants (monoclinic, unique axis c): a = 10.23, b = 15.53, c = 5.12 Angstrom; gamma = 98.6 degrees. The disagreement index for measured reflections is R-1 = 0.10

THE ROLE OF BUTYRIC ACID AS A OPROTECTIVE AGENT AGAINST INFLAMMATORY BOWEL DISEASE

Inflammatory Bowel disease (IBD), such as Crohn's disease and ulcerative colitis, are pathologies characterized by a chronic inflammation of the gastrointestinal tract. Their etiopathogenesis is not yet fully understood. Immune system and heat shock proteins (HSPs) dysfunctions are considered to be among the most likely causes of these diseases. Butyrate is a short-chain fatty acid produced by intestinal microflora. It has a trophic, benefical and protective role in the colonic mucosa, and it also induces changes in Hsp levels and localization. It may therefore be a valuable complementary therapeutic agent when used alongside trraditional drugs (mesalazine and corticosteroids) to treat the production of butyrate in the endoluminal environment may promote clinical remission in IBD patients. Due to these characteristics, there has been keen interest in the use of butyrate as a novel therapeutic supplement in the recent years. The current findings need to be validated through further clinical trials to better define the bbiomolecular dynamics of butyrate in the colonocytes of IBD patients

Neural-Based Ensembles and Unorganized Machines to Predict Streamflow Series from Hydroelectric Plants

Estimating future streamflows is a key step in producing electricity for countries with hydroelectric plants. Accurate predictions are particularly important due to environmental and economic impact they lead. In order to analyze the forecasting capability of models regarding monthly seasonal streamflow series, we realized an extensive investigation considering: six versions of unorganized machines—extreme learning machines (ELM) with and without regularization coefficient (RC), and echo state network (ESN) using the reservoirs from Jaeger’s and Ozturk et al., with and without RC. Additionally, we addressed the ELM as the combiner of a neural-based ensemble, an investigation not yet accomplished in such context. A comparative analysis was performed utilizing two linear approaches (autoregressive model (AR) and autoregressive and moving average model (ARMA)), four artificial neural networks (multilayer perceptron, radial basis function, Elman network, and Jordan network), and four ensembles. The tests were conducted at five hydroelectric plants, using horizons of 1, 3, 6, and 12 steps ahead. The results indicated that the unorganized machines and the ELM ensembles performed better than the linear models in all simulations. Moreover, the errors showed that the unorganized machines and the ELM-based ensembles reached the best general performances

Electronic Cigarettes and Cardiovascular Risk: Caution Waiting for Evidence

Electronic cigarettes use is a growing trend in contemporary societies, with the propensity to compete with traditional tobacco smoking. Some preclinical studies demonstrated the toxic and detrimental effects of electronic cigarettes liquid components. Its impact on human health remains unknown and insufficiently studied. While some studies suggest that electronic cigarettes use might be associated with endothelial dysfunction, impaired platelet function and increased risk of adverse clinical events, other studies did not confirm these findings and epidemiological data mostly suggest that the use of electronic cigarettes appears to be safer than that of traditional tobacco cigarettes. This article provides an up-to-date overview of the current state of knowledge regarding electronic cigarettes and their impact on human health, with special emphasis on their effect on cardiovascular diseases

Internal jugular vein fenestration: a rare but possible event. A case report and review of the literature

While fenestration and duplication are relatively common in the arteries, they are extremely rare in the venous compartment: internal jugular vein fenestration has been reported occurring in 0.4% of unilateral neck dissections. Familiarity with these morphological anomalies is important for the radiologist and for the surgeon to prevent neurovascular injury, especially in neck surgery and interventional catheterization. We present the case of a patient harboring a fenestration of the left internal jugular vein, diagnosed by magnetic resonance angiography, and a systematic review of the literature. To our knowledge, from 1985 until 2016 only 36 patients (including the present) were diagnosed as having an internal jugular vein morphological anomaly. Out of 36 patients, only 11 (30,5%) were diagnosed using radiological imaging; the high rate of intra-operative diagnoses (22/36, 62,5%) is likely related to the limited use of diagnostic imaging or to misdiagnosis/misinterpretation of a relatively unknown and rare morphological anomaly. A contrast enhanced computed tomography or magnetic resonance angiography should be considered in case of vascular procedures in a patient with known internal jugular vein anomaly

ORal anticoagulants In fraGile patients with percutAneous endoscopic gastrostoMy and atrIal fibrillation: the (ORIGAMI) study

BACKGROUND: Randomized trials support the safety and efficacy of direct oral anticoagulants (DOACs) versus vitamin K antagonists (VKAs) in patients with nonvalvular atrial fibrillation, leading to increased use of these compounds. Crushed forms of DOACs have been shown to be reliable, but evidence supporting percutaneous endoscopic gastrostomy (PEG) delivery is lacking. PEG is a long-term option for enteral food and drug delivery in patients unable to maintain oral intake, bypassing the risks and disadvantages of parenteral nutrition.AIMS: The ORal anticoagulants In fraGile patients with percutAneous endoscopic gastrostoMy and atrIal fibrillation (ORIGAMI) study investigates the safety and efficacy of Edoxaban administered via PEG in patients with atrial fibrillation and a clinical indication for a long-term anticoagulation.DESIGN: In this prospective, single-centre observational study, 12 PEG-treated patients with indication to anticoagulation will receive edoxaban via PEG and will be followed up to 6 months. Plasma antifactor Xa activity and edoxaban concentrations will be assessed. Thromboembolic (ischaemic stroke, systemic embolism, venous thromboembolism) and bleeding events (Bleeding Academic Research Consortium and Thrombolysis in Myocardial Infarction) will be recorded at 1 and 6 months.PRELIMINARY CASES: A retrospective analysis of five atrial fibrillation cases undergoing PEG implantation at our Institution who received edoxaban via PEG showed plasma anti-FXa levels at a steady state of 146 ± 15 ng/ml, without major adverse event at a mean follow-up of 6 months.CONCLUSION: ORIGAMI prospectively investigates PEG-administration of edoxaban in PEG-treated patients requiring long-term anticoagulation. Our preliminary retrospective data support this route of DOAC administration. CLINICALTRIALS.GOV IDENTIFIER: NCT04271293

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