43 research outputs found

    Towards hydrogen-rich ionic (NH4)(BH3NH2BH2NH2BH3) and related molecular NH3BH2NH2BH2NH2BH3

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    Attempts of synthesis of ionic (NH4)(BH3NH2BH2NH2BH3) using metathetical approach resulted in a mixture of the target compound and a partly dehydrogenated molecular NH3BH2NH2BH2NH2BH3 product. The mixed specimen was characterized by NMR and vibrational spectroscopies, and the crystal structure of their cocrystal was solved from powder x-ray diffraction data, and supplemented by theoretical density functional theory calculations. Despite their impressive hydrogen content, and similarly to ammonia borane, both title compounds release hydrogen substantially polluted with borazine, and traces of ammonia and diborane.Comment: 8 pages, 10 Figures, 2 Tables, and electronic supplement of 19 page

    Advantages of Al based GEM detector aimed at plasma soft-semi hard X-ray radiation imaging

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    Development of gaseous detectors, more specifically Gas Electron Multiplier (GEM) based detectors, for application at tokamak plasma radiation monitoring/imaging in Soft−Semi Hard X-ray (S−SH) region is an ongoing research activity aiming to deliver valuable information on plasma shape, magnetic configuration, non-axisymmetry phenomena of the plasma, etc. Wide radiation range and brightness of plasma radiation impose some restrictions on choice of materials in the detecting chamber, as their interaction with the incident radiation may disrupt original signals. This work proposes usage of aluminum as GEM foils electrodes for the first time. The detector based on these foils was constructed and examined. The operational characteristics and spectral capabilities of such detector were compared with the ones based on the standard (commonly used) copper GEM foils. The laboratory tests were performed using X-ray tube and 55Fe sources to examine detectors’ capabilities in energy-resolved imaging. Additionally, simulations of origin and number of the generated electrons, which determine the detector signal, were performed for Al and Cu GEM foils for a wide energy range of incident photons. The experimental and modelling data demonstrated that Cu based GEM detector produces higher parasitic signal than Al one necessitating total elimination of copper from detector’s chamber

    Measurement capabilities upgrade of GEM soft X-ray measurement system for hot plasma diagnostics

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    The paper presents improvements of the developed system for hot plasma radiation measurement in the soft X-ray range based on a Gas Electron Multiplier (GEM) detector. Scope of work consists of a new solution for handling hardware time-synchronization with tokamak systems needed for better synchronization with other diagnostics and measurement quality. The paper describes the support of new modes of triggering on PC-side. There are communication and data path overview in the system. The new API is described, which provide separate channels for data and control and is more robust than the earlier solution. Work concentrates on stability and usability improvements of the implemented device providing better usage for end-user

    Development of 2D GEM-based SXR plasma imaging for DTT device: focus on readout structure

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    Creation and development of a new diagnostics useful for future thermonuclear reactors and helpful in studying impurity profiles, MHD modes/localization, and imaging are among urgent tasks in plasma research field. Global SXR imaging for DTT device in support of power exhaust programme and its consecutive impact for plasma core is an example of applicability of such diagnostics. This contribution presents the results of the ongoing development of the elaborated plasma X-ray imaging technology focusing on the design of the relevant structure of readout electrode. In order to achieve that, the details on the expected plasma radiation for the selected scenario for DTT machine were assessed. Then, the spatial distribution of plasma radiation intensity flux that will be reaching the detector window of the GEM based detector was simulated. Taking it into account along with the physical properties of the detector, the spatial and temporal distributions of charge cloud that will be reaching the readout plane were evaluated. The special design of the readout structure has been proposed that fulfil critical conditions originated from technological and physical constraints. The final effectiveness of the GEM based detector was evaluated proving that such detector is well suited for an effective plasma radiation imaging

    Effect of charging-up and regular usage on performance of the triple GEM detector to be employed for plasma radiation monitoring

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    After the problem of high-temperature plasma confinement, construction of diagnostics that is able to identify plasma contamination with impurities and to determine impurity distribution is another critically important issue. Solution of this problem would enable progress towards the success in controlled thermonuclear fusion. A new diagnostics, based on Gas Electron Multiplier (GEM) technology, has been recently developed for poloidal tomography focused on radiation of the metal impurities by monitoring in Soft X-Ray (SXR) region. GEM based detectors would undergo much less damage by neutrons than standard semiconductor diodes which results in better operational stability. This paper emphasizes the results of the latest examination of this type of detectors, showing influence of the charging-up effect on the detector performance and its physical properties for expected plasma radiation intensity. In addition, an undesired influence of aging of the detector window’s material on the performance of the GEM detector is also shown: regular (moderate or active) usage could lead to changes of material’s morphology as well as its composition. This study confirms the importance of further research into material’s optimization of GEM detectors used as a base for SXR tomographic diagnostics aimed to work under different plasma radiation conditions

    Amino- and polyaminophthalazin-1(2H)-ones : synthesis, coordination properties, and biological activity

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    Amino- and polyaminophthalazinones were synthesized by the palladium‐catalyzed amination (alkyl- and arylamines, polyamines) of 4-bromophthalazinones in good yields. The coordinating properties of selected aminophthalazinones towards Cu(II) ions were investigated and the participation of the nitrogen atoms in the complexation of the metal ion was shown. A biological screening of the potential cytotoxicity of selected synthesized compounds on HT-29 and PC-3 cell lines, as well as on the L-929 cell line, proved that some amino derivatives of phthalazinone show interesting anticancer activities. The detailed synthesis, spectroscopic data, and biological assays are reported

    New genetic loci link adipose and insulin biology to body fat distribution.

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    Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

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    Abstract: Degenerative disease of the lumbar spine is one of the most common diseases of the human musculoskeletal system and a significant public health problem. The main manifestation of degenerative spine disease is back pain, which in most cases is treated symptomatically rather than causally. The diagnosis of degenerative spine disease has been previously based on medical history and diagnostic imaging. Recently, much attention has been devoted to the biochemical indicators of bone and cartilage metabolism, which are well understood among patients with osteoporosis. Bone turnover markers indicate the metabolic activity of bone and cartilage. They occur in blood serum, urine, and synovial fluid in the form of collagen-derived proteins or enzymes, involved in the formation or resorption of bone and cartilage tissue. The study below was aimed at assessing the usefulness of determining the markers of bone turnover and cartilage damage in the blood serum of people with degenerative disease of the lumbar spine diagnosed by MRI. The biochemical diagnostics included the measurement of inflammatory parameters. The results show that the degenerative disease of the spine is local, accompanied by inflammation, and vitamin D deficiency is among the factors leading to its development

    Human Milk Oligosaccharides: Health Benefits, Potential Applications in Infant Formulas, and Pharmacology

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    The first months of life are a special time for the health development and protection of infants. Breastfeeding is the natural and best way of feeding an infant, and positively influences their development and health. Breast milk provides the ideal balance of nutrients for the infant and contains countless bioactive ingredients such as immunoglobulins, hormones, oligosaccharides and others. Human milk oligosaccharides (HMOs) are a very important and interesting constituent of human milk, and are the third most abundant solid component after lactose and lipids. They are a structurally and biologically diverse group of complex indigestible sugars. This article will discuss the mechanisms of action of HMOs in infants, such as their anti-adhesive properties, properties modulating the immune system, and impact on bacterial flora development. Many health benefits result from consuming HMOs. They also may decrease the risk of infection by their interactions with viruses, bacteria or protozoa. The commercial use of HMOs in infant formula, future directions, and research on the use of HMOs as a therapy will be discussed

    Perspective of SGLT2 Inhibition in Treatment of Conditions Connected to Neuronal Loss: Focus on Alzheimer’s Disease and Ischemia-Related Brain Injury

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    Sodium-glucose co-transporter 2 inhibitors (SGLT2i) are oral anti-hyperglycemic agents approved for the treatment of type 2 diabetes mellitus. Some reports suggest their presence in the central nervous system and possible neuroprotective properties. SGLT2 inhibition by empagliflozin has shown to reduce amyloid burden in cortical regions of APP/PS1xd/db mice. The same effect was noticed regarding tau pathology and brain atrophy volume. Empagliflozin presented beneficial effect on cognitive function, which may be connected to an increase in cerebral brain-derived neurotrophic factor. Canagliflozin and dapagliflozin may possess acetylcholinesterase inhibiting activity, resembling in this matter Alzheimer&rsquo;s disease-registered therapies. SGLT2 inhibitors may prove to impact risk factors of atherosclerosis and pathways participating both in acute and late stage of stroke. Their mechanism of action can be related to induction in hepatocyte nuclear factor-1&alpha;, vascular endothelial growth factor-A, and proinflammatory factors limitation. Empagliflozin may have a positive effect on preservation of neurovascular unit in diabetic mice, preventing its aberrant remodeling. Canagliflozin seems to present some cytostatic properties by limiting both human and mice endothelial cells proliferation. The paper presents potential mechanisms of SGLT-2 inhibitors in conditions connected with neuronal damage, with special emphasis on Alzheimer&rsquo;s disease and cerebral ischemia
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