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1.
Alan Rigter Jan PM Langeveld Drophatie Timmers-Parohi Jorg G Jacobs Peter LJM Moonen Alex Bossers 《BMC biochemistry》2007,8(1):6
Background
The common event in transmissible spongiform encephalopathies (TSEs) or prion diseases is the conversion of host-encoded protease sensitive cellular prion protein (PrPC) into strain dependent isoforms of scrapie associated protease resistant isoform (PrPSc) of prion protein (PrP). These processes are determined by similarities as well as strain dependent variations in the PrP structure. Selective self-interaction between PrP molecules is the most probable basis for initiation of these processes, potentially influenced by chaperone molecules, however the mechanisms behind these processes are far from understood. We previously determined that polymorphisms do not affect initial PrPC to PrPSc binding but rather modulate a subsequent step in the conversion process. Determining possible sites of self-interaction could elucidate which amino acid(s) or amino acid sequences contribute to binding and further conversion into other isoforms. To this end, ovine – and bovine PrP peptide-arrays consisting of 15-mer overlapping peptides were probed with recombinant sheep PrPC fused to maltose binding protein (MBP-PrP). 相似文献2.
3.
Metal/superconductor/semiconductor (Ag/Hg-1212/CdSe) hetero-nanostructures have been fabricated using pulse-electrodeposition
technique and are characterized by X-ray diffraction (XRD), full-width at half-maximum (FWHM) and scanning electron microscopy
(SEM) studies. The junction capacitance of Ag/Hg-1212, Hg-1212/CdSe and Ag/Hg-1212/CdSe heterojunctions is measured in dark
and under laser irradiation at room temperature. The nature of the junction formed and built-in-junction potentials were determined.
The increase in carrier concentration across the junction due to photo-irradiation has been observed. 相似文献
4.
One of the innovative technological directions for the high-temperature superconductors has been persued by fabricating the
heteroepitaxial multilayer structures such as superconductor-semiconductor heterostructures. In the present investigation,
metal/superconductor/semiconductor (Ag/Tl-2223/CdSe) hetero-nanostructures have successfully been fabricated using dc electrodeposition
technique and were characterized by X-ray diffraction (XRD), full-width at half-maximum (FWHM) and scanning electron microscopy
(SEM) studies. The measurement of junction capacitance as a function of biasing voltage was used for the estimation of junction
built-in-potential (V
D) and to study the charge distribution in a heterojunction. The Mott-Schottky plots were measured for each junction in dark
and under the photo-irradiation. The effect of laser irradiation on C-V characteristics of hetero-nanostructure has been studied. 相似文献
5.
Despite the burgeoning interest in the various biological functions and consequent therapeutic potential of the vast number of oligosaccharides found in nature on glycoproteins and cell surfaces, the development of combinatorial carbohydrate chemistry has not progressed as rapidly as expected. The reason for this imbalance is rooted in the difficulty of oligosaccharide assembly and analysis that renders synthesis a rather cumbersome endeavor. Parallel approaches that generate series of analogous compounds rather than real libraries have therefore typically been used. Since generally low affinity is obtained for interactions between carbohydrate receptors and modified oligosaccharides designed as mimetics of natural carbohydrate ligands, glycopeptides have been explored as alternative mimics. Glycopeptides have been proven in many cases to be superior ligands with higher affinity for a receptor than the natural carbohydrate ligand. High-affinity glycopeptide ligands have been found for several types of receptors including the E-, P-, and L-selectins, toxins, glycohydrolases, bacterial adhesins, and the mannose-6-phosphate receptor. Furthermore, the assembly of glycopeptides is considerably more facile than that of oligosaccharides and the process can be adapted to combinatorial synthesis with either glycosylated amino acid building blocks or by direct glycosylation of peptide templates. The application of the split and combine approach using ladder synthesis has allowed the generation of very large numbers of compounds which could be analyzed and screened for binding of receptors on solid phase. This powerful technique can be used generally for the identification and analysis of the complex interaction between the carbohydrates and their receptors. 相似文献
6.
Thomas JB Kline MC Schiller SB Ellerbe PM Sniegoski LT Duewer DL Sharpless KE 《Analytical and bioanalytical chemistry》1996,356(1):1-9
In Standard Reference Material 968b, fat-soluble vitamins and cholesterol in human serum, certified values are provided for cholesterol, retinol, retinyl palmitate, -tocopherol, trans--carotene, total -carotene (trans plus cis isomers), total -carotene, and lutein. Non-certified values are also reported for -tocopherol (includes -tocopherol), -tocopherol, zeaxanthin, -cryptoxanthin, trans-lycopene, trans-lycopene, trans--carotene, total lycopene, 9-cis-carotene, 13- plus 15-cis--carotene, and 15-cis--carotene. Both certified and non-certified values are based on the agreement among results from three different liquid chromatographic analytical procedures developed at NIST and from an interlaboratory comparison exercise among institutions that participate in a NIST-managed Micronutrients Measurement Quality Assurance Program. Cholesterol is certified in this material using the NIST isotope dilution/mass spectrometric definitive method. 相似文献
7.
Enzymatic Oxygen Microsensor Based on Bilirubin Oxidase Applied to Microbial Fuel Cells Analysis 下载免费PDF全文
Matteo Grattieri Sofia Babanova Carlo Santoro Edoardo Guerrini Stefano PM Trasatti Pierangela Cristiani Massimiliano Bestetti Plamen Atanassov 《Electroanalysis》2015,27(2):327-335
A selective oxygen biosensor based on bilirubin oxidase (BOx) was developed. The sensor was used for determining oxygen profiles in a membraneless, single‐chamber microbial fuel cell (SCMFC), fed with raw wastewater. The linear response of the sensor was optimized by a diffusion layer of silica gel. A computer‐controlled stage was used to obtain accurate and precise measurements. Oxygen concentration in biofilms covering electrodes was measured, showing 3 mg L?1 of O2 in the bulk solution, decreasing to 0 mg L?1 in the cathodic biofilm. The MFC generated power in the range of 0–0.08 mW, associated to the oxygen content. 相似文献
8.
9.
C. S. Phinney K. E. Murphy M. J. Welch P. M. Ellerbe S. E. Long K. W. Pratt S. B. Schiller L. T. Sniegoski M. S. Rearick T. W. Vetter R. D. Vocke 《Fresenius' Journal of Analytical Chemistry》1998,361(2):71-80
The National Institute of Standards and Technology (NIST) has developed several Standard Reference Materials (SRMs) based
on human serum. NIST SRM 909b, Human Serum, is a lyophilized human serum material with concentrations for seven organic and
six inorganic analytes at two levels certified solely by definitive methods (DMs). This material provides the vehicle by which
high precision, high accuracy measurements made with DMs at NIST can be transferred through the measurement hierarchy to other
laboratories. Isotope dilution gas chromatographic-mass spectrometric (GC-IDMS) methods were applied to measure cholesterol,
creatinine, glucose, urea, uric acid, triglycerides, and total glycerides. Thermal ionization isotope dilution mass spectrometry
(TI-IDMS) was used for determination of lithium, magnesium, potassium, calcium, and chloride. In addition, chloride was determined
by coulometry, providing a comparison between two DMs. Sodium, which lacks a stable isotope that would permit isotope dilution
mass spectrometric (IDMS) measurement, was determined by gravimetry. SRM 909b includes certified values for total glycerides
and triglycerides, which were not certified in the previous lot of this material (SRM 909a). Improvement in uniformity of
vial fill weight in the production of SRM 909b resulted in smaller certified uncertainties over previous freeze-dried serum
SRMs. Uncertainties at the 99% level of confidence for relative expanded uncertainty (%) for certification of the organic
analytes on a mmol/L/g basis ranged from 0.44% for urea (level II) to 5.04% for glucose (level II). (In-house studies have
shown glucose to be a relatively unstable analyte in similar lyophilized serum materials, degrading at about 1% per year.)
Relative expanded uncertainties (99% C.I.) for certification of inorganic analytes on a mmol/L/g basis ranged from 0.25% for
chloride (level I) to 0.49% for magnesium (level II).
Received: 30 July 1997 / Revised: 24 October 1997 / Accepted: 31 October 1997 相似文献
10.
Alan Rigter Jan Priem Drophatie Timmers-Parohi Jan PM Langeveld Fred G van Zijderveld Alex Bossers 《BMC biochemistry》2009,10(1):29-16