| 1. |
- Berto, Marcello, et al.
(författare)
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EGOFET Peptide Aptasensor for Label-Free Detection of Inflammatory Cytokines in Complex Fluids
- 2018
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Ingår i: ADVANCED BIOSYSTEMS. - : WILEY-V C H VERLAG GMBH. - 2366-7478. ; 2:2
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Tidskriftsartikel (refereegranskat)abstract
- Organic electronic transistors are rapidly emerging as ultrahigh sensitive label-free biosensors suited for point-of-care or in-field deployed applications. Most organic biosensors reported to date are based on immunorecognition between the relevant biomarkers and the immobilized antibodies, whose use is hindered by large dimensions, poor control of sequence, and relative instability. Here, an electrolyte-gated organic field effect transistor (EGOFET) biosensor where the recognition units are surface immobilized peptide aptamers (Affimer proteins) instead of antibodies is reported. Peptide aptasensor for the detection of the pro-inflammatory cytokine tumor necrosis factor alpha (TNF alpha) with a 1 x 10(-12) M limit of detection is demonstrated. Ultralow sensitivity is met even in complex solutions such as cell culture media containing 10% serum, demonstrating the remarkable ligand specificity of the device. The device performances, together with the simple one-step immobilization strategy of the recognition moieties and the low operational voltages, all prompt EGOFET peptide aptasensors as candidates for early diagnostics and monitoring at the point-of-care.
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| 2. |
- Jain, Sagar Motilal, et al.
(författare)
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Acid-catalyzed oligomerization via activated proton transfer to aromatic and unsaturated monomers in Nafion membranes : a step forward in the in situ synthesis of conjugated composite membranes
- 2016
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 6:106, s. 104782-104792
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Tidskriftsartikel (refereegranskat)abstract
- An approach to perform controlled acid-catalyzed oligomerization via vapor pressure control of thereactions inside Nafion membranes is presented. The interaction of Nafion with several classes ofaromatic (pyrrol, furan, thiophene) and unsaturated (methyl-acetylene) gas phase monomers was studiedas a function of contact time and temperature by in situ vibrational (FTIR) and electronic (UV-Vis)spectroscopy with the support from theoretical linear response and time dependent DFT calculations tomonitor the vibrations and the effective number of conjugated double bonds. The formation ofH-bonded adduct as seen from IR spectroscopy transforms the hydrogen bonded species into positivelycharged oligomers through an activated proton transfer mechanism where oligomerization progressthrough increasing contact time with the respective gas phase reactants at room temperature. Theactivated proton transfer oligomerization proceeds through the stepwise growth propagation cycles viacarbocationic intermediates, finally leads to the formation of irreversible, conjugated charged oligomersas a product. The colored, conjugated oligomeric Nafion composite products are formed at roomtemperature as a function of reaction time and are irreversible after complete degassing of the gas phasereactants as well stable in ambient environment stored for many days in pure oxygen or air and cannotbe extracted with common solvents, appearing strongly encapsulated inside Nafion membranes. This iscrucial for future applications of the presented route for direct production of conjugated species insideNafion and thus production and control of composite membrane materials of interest in fuel cells andcatalysis.
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| 3. |
- Saldan, Ivan, et al.
(författare)
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Hydrogen Sorption in the LiH-LiF-MgB2 System
- 2013
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Ingår i: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 117:33, s. 17360-17366
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Tidskriftsartikel (refereegranskat)abstract
- A composite material in the LiH-LiF-MgB2 system has been synthesized by high-energy ball milling. Some peaks in addition to that of the binary 2LiH-MgB2 and 2LiF-MgB2 systems are observed for the composite material by high-pressure differential scanning calorimetry (HP-DSC), indicating the formation of intermediate phases. In situ synchrotron radiation powder X-ray diffraction (SR-PXD) performed at 60 bar of H-2 and 390 degrees C shows a superposition of both reaction pathways that are typical for 2LiH-MgB2 and 2LiF-MgB2. After hydrogen absorption of the LiH-LiF-MgB2 composite the vibrational modes of LiBH4 were observed by attenuated total reflection infrared (ATR-IR) spectroscopy. The F-19 MAS NMR spectrum of the LiF-LiBH4 sample after heat treatment in hydrogen is strongly dominated by the centerband and spinning sidebands from LiF; in addition, a low-intensity resonance, very similar to that of [BF4](-) ion, is identified.
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| 4. |
- van Leeuwen, F., et al.
(författare)
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Gaia Data Release 1 : Open cluster astrometry: Performance, limitations, and future prospects
- 2017
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Ingår i: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 601
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Tidskriftsartikel (refereegranskat)abstract
- Context. The first Gaia Data Release contains the Tycho-Gaia Astrometric Solution (TGAS). This is a subset of about 2 million stars for which, besides the position and photometry, the proper motion and parallax are calculated using Hipparcos and Tycho-2 positions in 1991.25 as prior information. Aims. We investigate the scientific potential and limitations of the TGAS component by means of the astrometric data for open clusters. Methods. Mean cluster parallax and proper motion values are derived taking into account the error correlations within the astrometric solutions for individual stars, an estimate of the internal velocity dispersion in the cluster, and, where relevant, the effects of the depth of the cluster along the line of sight. Internal consistency of the TGAS data is assessed. Results. Values given for standard uncertainties are still inaccurate and may lead to unrealistic unit-weight standard deviations of least squares solutions for cluster parameters. Reconstructed mean cluster parallax and proper motion values are generally in very good agreement with earlier Hipparcos-based determination, although the Gaia mean parallax for the Pleiades is a significant exception. We have no current explanation for that discrepancy. Most clusters are observed to extend to nearly 15 pc from the cluster centre, and it will be up to future Gaia releases to establish whether those potential cluster-member stars are still dynamically bound to the clusters. Conclusions. The Gaia DR1 provides the means to examine open clusters far beyond their more easily visible cores, and can provide membership assessments based on proper motions and parallaxes. A combined HR diagram shows the same features as observed before using the Hipparcos data, with clearly increased luminosities for older A and F dwarfs.
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| 5. |
- Zoccali, Carmine, et al.
(författare)
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Neuropeptide Y as a risk factor for cardiorenal disease and cognitive dysfunction in chronic kidney disease : translational opportunities and challenges
- 2022
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Ingår i: Nephrology, Dialysis and Transplantation. - : Oxford University Press. - 0931-0509 .- 1460-2385. ; 37, s. 14-23
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Forskningsöversikt (refereegranskat)abstract
- Neuropeptide Y (NPY) is a 36-amino-acid peptide member of a family also including peptide YY and pancreatic polypeptide, which are all ligands to Gi/Go coupled receptors. NPY regulates several fundamental biologic functions including appetite/satiety, sex and reproduction, learning and memory, cardiovascular and renal function and immune functions. The mesenteric circulation is a major source of NPY in the blood in man and this peptide is considered a key regulator of gut-brain cross talk. A progressive increase in circulating NPY accompanies the progression of chronic kidney disease (CKD) toward kidney failure and NPY robustly predicts cardiovascular events in this population. Furthermore, NPY is suspected as a possible player in accelerated cognitive function decline and dementia in patients with CKD and in dialysis patients. In theory, interfering with the NPY system has relevant potential for the treatment of diverse diseases from cardiovascular and renal diseases to diseases of the central nervous system. Pharmaceutical formulations for effective drug delivery and cost, as well as the complexity of diseases potentially addressable by NPY/NPY antagonists, have been a problem until now. This in part explains the slow progress of knowledge about the NPY system in the clinical arena. There is now renewed research interest in the NPY system in psychopharmacology and in pharmacology in general and new studies and a new breed of clinical trials may eventually bring the expected benefits in human health with drugs interfering with this system.
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