Quantitation of resveratrol in red wines by means of stable isotope dilution analysis-ultra-performance liquid chromatography-Quan-time-of-flight mass spectrometry and cross validation

A stable isotope dilution analysis (SIDA) was developed for the quantitative analysis of the health-promoting phytoalexin (E)-resveratrol in red wines by means of UPLC-QuanTOF-MS. After hemisynthetic preparation of (E)-3,5,4'-trihydroxy-2,4,6-trideuterostilbene ((E)-[(2)H(3)]-resveratrol) as the stable isotope labeled internal standard, validation experiments revealed recovery rate of 96.2 ± 0.8% RSD, thus demonstrating the robustness and accuracy of the SIDA-UPLC-QuanTOF-MS method. Repeatability and reproducibility expressed as RSD showed excellent values of 3.0% and 4.0% for (E)-[(2)H(3)]-resveratrol. Cross validation against a SIDA-HPLC-MS/MS analysis using a triple quadrupole mass spectrometer revealed comparable data, but the SIDA-UPLC-QuanTOF-MS was four times faster, thus making the latter method preferential for an accurate high-throughput analysis of wine samples. Comparison of the SIDA data to those obtained by quantitation using a standard addition method and external calibration, respectively, revealed 97.7% and 32.4% of the resveratrol concentration determined by means of SIDA-UPLC-QuanTOF-MS and 101.0% and 12.7% of the resveratrol levels found by using SIDA-HPLC-MS/MS.     

Associations between CXCR1 polymorphisms and pathogen-specific incidence rate of clinical mastitis,test-day somatic cell count,and test-day milk yield

The CXCR1 gene plays an important role in the innate immunity of the bovine mammary gland. Associations between single nucleotide polymorphisms (SNP) CXCR1c.735C>G and c.980A>G and udder health have been identified before in small populations. A fluorescent multiprobe PCR assay was designed specifically and validated to genotype both SNP simultaneously in a reliable and cost-effective manner. In total, 3,106 cows from 50 commercial Flemish dairy herds were genotyped using this assay. Associations between genotype and detailed phenotypic data, including pathogen-specific incidence rate of clinical mastitis (IRCM), test-day somatic cell count, and test-day milk yield (MY) were analyzed. Staphylococcus aureus IRCM tended to associate with SNP c.735C>G. Cows with genotype c.735GG had lower Staph. aureus IRCM compared with cows with genotype c.735CC (rate ratio = 0.35, 95% confidence interval = 0.14–0.90). Additionally, a parity-specific association between Staph. aureus IRCM and SNP c.980A>G was detected. Heifers with genotype c.980GG had a lower Staph. aureus IRCM compared with heifers with genotype c.980AG (rate ratio = 0.15, 95% confidence interval = 0.04–0.56). Differences were less pronounced in multiparous cows. Associations between CXCR1 genotype and somatic cell count were not detected. However, MY was associated with SNP c.735C>G. Cows with genotype c.735GG out-produced cows with genotype c.735CC by 0.8 kg of milk/d. Results provide a basis for further research on the relation between CXCR1 polymorphism and pathogen-specific mastitis resistance and MY.     

Integration and electrical characterization of carbon nanotube via interconnects

Carbon nanotubes (CNTs) are considered a promising material for interconnects in the future generations of microchips because of their low electrical resistance and excellent mechanical stability. In particular, CNT-based contacts appear advantageous when compared with current tungsten or copper technologies and could therefore find an application as metal contacts interconnecting the transistors with the back end of line of the microchip. In this work, the integration of vertical CNT bundles in sub-micron contact holes is evaluated at wafer scale and the major integration challenges encountered in the practical realization of the process are discussed. Nickel PVD films were used to selectively grow CNT into the contact holes at temperatures as low as 400 °C, which is the thermal budget available for contacts. The height of the contacts and the length of the CNT are controlled by a chemical mechanical polishing step (CMP) after embedding the CNT into SiO₂. Ti/Au metal pads are then formed onto the CNT bundles by PVD and lift-off. The integrated CNT are electrically characterized and an annealing treatment was found to improve the CNT-via resistance. As the electrical properties of the CNT can be evaluated, the structure and the process presented constitute a test vehicle for the development of high-quality CNT-contacts.     

On the porosity of polypyrrole films

Polypyrrole (PPy) films doped with anions of various size, charge and chemical nature (inorganic, surfactant, with aromatic ring) were electrochemically synthesized and investigated by low-temperature N₂ sorption experiments at −196 °C. The specific surface area, total pore volume, average pore radius, pore size distribution and other parameters for oxidized PPy films using dodecylsulfate, 2-naphthalene sulfonate, 1,5-naphthalene disulfonate, poly(4-styrenesulfonate), tosylate, perchlorate, nitrate and chloride as dopant ions, were calculated. The obtained data show that although the average pore radius of investigated mesoporous PPy films (17–19 Å) is practically independent of the dopant anion used, however the latter determines the total pore volume and specific surface area values in different PPy materials investigated. As the total pore volumes for PPy films doped with large amphiphilic anions show the smallest values, the corresponding values for PPy/small inorganic anions, are up to 2 times higher.     

A trial of three regimens for primary amyloidosis: colchicine alone, melphalan and prednisone, and melphalan, prednisone, and colchicine

BACKGROUND: Primary systemic amyloidosis is an uncommon disease characterized by the accumulation in vital organs of a fibrillar protein consisting of monoclonal light chains. METHODS: We treated 220 patients with biopsy-proved amyloidosis. The patients were randomly assigned to receive colchicine (72 patients), melphalan and prednisone (77), or melphalan, prednisone, and colchicine (71). They were stratified according to their chief clinical manifestations: renal disease (105 patients), cardiac involvement (46), peripheral neuropathy (19), or other (50). RESULTS: The median duration of survival after randomization was 8.5 months in the colchicine group, 18 months in the group assigned to melphalan and prednisone, and 17 months in the group assigned to melphalan, prednisone, and colchicine (P<0.001). Among patients who had a reduction in serum or urine monoclonal protein at 12 months, the overall length of survival was 50 months, whereas among those without a reduction at 12 months, the overall length of survival was 36 months (P=0.03). Thirty-four patients (15 percent) survived for five years or longer. CONCLUSIONS: Therapy with melphalan and prednisone results in objective responses and prolonged survival as compared with colchicine in patients with primary amyloidosis.     

Cartilage Turnover Reflected by Metabolic Processing of Type II Collagen: A Novel Marker of Anabolic Function in Chondrocytes

The aim of this study was to enable measurement of cartilage formation by a novel biomarker of type II collagen formation. The competitive enzyme-linked immunosorbent assay (ELISA) Pro-C2 was developed and characterized for assessment of the beta splice variant of type II procollagen (PIIBNP). This is expected to originate primarily from remodeling of hyaline cartilage. A mouse monoclonal antibody (Mab) was raised in mouse, targeting specifically PIIBNP (QDVRQPG) and used in development of the assay. The specificity, sensitivity, 4-parameter fit and stability of the assay were tested. Levels of PIIBNP were quantified in human serum (0.6–2.2 nM), human amniotic fluid (163–188 nM) and sera from different animal species, e.g., fetal bovine serum (851–901 nM) with general good linearity (100% (SD 7.6) recovery) and good intra- and inter-assay variation (CV% < 10). Dose (0.1 to 100 ng/mL) and time (7, 14 and 21 days) dependent release of PIIBNP were evaluated in the conditioned medium from bovine cartilage explants (BEX) and human cartilage explants (HEX) upon stimulation with insulin-like growth factor (IGF-1), transforming growth factor (TGF)-β1 and fibroblastic growth factor-2 (FGF-2). TGF-β1 and IGF-1 in concentrations of 10–100 ng/mL significantly (p < 0.05) induced release of PIIBNP in BEX compared to conditions without treatment (WO). In HEX, IGF-1 100 ng/mL was able to induce a significant increase of PIIBNP after one week compared to WO. FGF-2 did not induce a PIIBNP release in our models. To our knowledge this is the first assay, which is able to specifically evaluate PIIBNP excretion. The Pro-C2 assay seems to provide a promising and novel marker of type II collagen formation.     

On Planning of Optical Networks and Representation of their Uncertain Input Parameters

This paper studies the use of uncertain inputs in the strategic network planning process. To model uncertain planning inputs three essential parameters are needed the predicted value expressing for instance an expert’s view, the uncertainty level indicating the doubt there is about the predicted value, and the confidence parameter denoting the probability that the output parameter was estimated big enough (compared to the actual output). Several planning approaches that handle uncertain variables are distinguished and their strengths and shortcomings are indicated. This allows to indicate the pitfalls in some common planning practices that use a fixed safety margin to handle uncertainty. It is shown that they can lead to incorrect planning decisions, such as underestimation of the impact of the input uncertainty and overdimensioning in case of inaccurately modelled dimensioning problems. Both a theoretic model and simulation results are shown. A real-life planning problem is studied, including forecasting future network traffic from uncertain inputs and dimensioning a network to accommodate an uncertain traffic demand.     

Techno-economic evaluation of the island based introduction of optical cross connects in an IP-over-WDM network

This article compares several traffic grooming approaches, based on expected capital expenditures (capex) to dimension and expand the network. For small traffic demands, the link-by-link grooming approach (efficiently filling SDH frames) is most interesting. We illustrate that, as traffic increases, there comes a point where the savings in IP layer expenses realized by end-to-end grooming compensate the extra expenses of introducing the needed optical cross connects (OXCs). We study the network-wide migration from link-by-link towards end-to-end grooming at a single point in time, as well as a possible migration path, where OXCs are introduced gradually in so-called end-to-end grooming islands. This approach can lead to important savings in capex. We study total equipment costs as well as incremental and cumulative costs, indicating the total expenses to be paid by the operator over a certain time. The use of the Net Present Value (NPV) technique is clarified. Finally, also the sensitivity of the obtained results to changes in the component costs is studied.     

Impedance spectroscopy data for S2O8 anion electroreduction at Bi(1 1 1) plane

Electroreduction kinetics of the peroxodisulfate anions on the electrochemically polished Bi(1 1 1) single crystal electrode has been studied by impedance spectroscopy. Influence of the electrode potential, reaction intermediates, base electrolyte and reactant concentrations on the kinetic parameters of electroreduction has been established. Systematic analysis of the fitting results demonstrates the noticeable influence of adsorption of the reaction intermediate or reactant on the electroreduction rate of the S₂O₈²⁻ anions at the Bi(1 1 1) electrode. In the region of so-called “current pits” in the cyclic voltammetry curves, obtained by rotating disc electrode method, the mixed kinetics, i.e. the adsorption and “true” charge transfer limited steps have been established by impedance spectroscopy.     

Adsorption of 1,6-hexanediol on Bi single crystal electrodes

Cyclic voltammetry (CV) and electrochemical impedance spectroscopy have been employed for the quantitative study of 1,6-hexanediol (HD) adsorption at the Bi(0 0 1) and Bi(l 1 1)|0.05 M Na₂SO₄ aqueous solution interfaces. According to the experimental data the Bi(l 1 1) interface has more negative zero charge potential and the adsorption-desorption peaks appear at more negative potentials than in case of Bi(0 0 1) interface. However, the adsorption activity is practically similar for Bi(0 0 1) and Bi(l 1 1) planes. The surface area occupied by one adsorbed molecule S_max equal to 0.47 nm² at the maximum adsorption potential indicates that HD molecules have flat orientation on Bi(h k l) surfaces. For less concentrated solutions the capacitance decreases in the maximum adsorption area as HD concentration increases, but in case of HD concentrations above 0.5 M the capacitance starts to increase. Cyclic voltammetry results show the capacitive adsorption and desorption peaks at higher potential scan rates for solutions with addition of HD in the base electrolyte solution.