Search results for "tandem"

Urinary ethyl glucuronide (uEtG) as a marker for alcohol consumption in liver transplant candidates: a real-world cohort

2020

 In order to reduce alcohol relapse after liver transplantation (LT), the German national guidelines for waiting-list maintenance and organ allocation demand a minimum 6-month period of alcohol abstinence pre-LT, confirmed by measuring urinary ethyl glucuronide (uEtG). Between January 2015 and June 2016, uEtG was measured at least once in 339 cirrhotic patients with an indication for LT at the University Medical Center Mainz. uEtG was measured with an enzyme-linked immunosorbent assay (ELISA) screening test (cutoff value: 500 µg/L). For uEtG values ≥ 500 µg/L, liquid chromatography-mass spectrometry (LC-MS/MS) was performed as a confirmatory assay. Data were collected prospectively in a tra…

Human milk enhances antioxidant defenses against hydroxyl radical aggression in preterm infants

2008

Background: Preterm infants endowed with an immature antioxidant defense system are prone to oxidative stress. Hydroxyl radicals are very aggressive reactive oxygen species that lack specific antioxidants. These radicals cannot be measured directly, but oxidation byproducts of DNA or phenylalanine in urine are reliable markers of their activity. Human milk has a higher antioxidant capacity than formula. Objective: We hypothesized that oxidative stress associated with prematurity could be diminished by feeding human milk. Design: We recruited a cohort of stable preterm infants who lacked perinatal conditions associated with oxidative stress; were not receiving prooxidant or antioxidant drugs…

DXYS156: a multi-purpose short tandem repeat locus for determination of sex, paternal and maternal geographic origins and DNA fingerprinting

2002

In forensic science and in legal medicine Y chromosomal typing is indispensable for sex determination, for paternity testing in the absence of the father and for distinguishing males in multiple rape cases. Another potential application is the estimation of paternal geographic origin or family name from a crime stain to narrow down the range of suspects and thus reduce costs of mass screenings. However, Y typing alone cannot provide a sufficiently resolved DNA fingerprint as required for court convictions. Thus, there is a dilemma whether or not to sacrifice valuable material for the sake of extensive Y chromosomal investigations when stain DNA is limited (typically allowing only few PCR am…

Effect of inhibiting carnitine biosynthesis on male rat sexual performance.

2008

l-carnitine has a documented role as a cofactor in cellular energy metabolism and fatty acid beta-oxidation pathways and it has also been considered to function in reproductive biology. We investigated whether decreasing concentrations of L-carnitine using an inhibitor of its biosynthesis, mildronate (3-(2,2,2-trimethylhydrazinium)-propionate), would influence the sexual behavior or sperm quality in male rats. Mildronate treatment induced a significant decrease in carnitine concentration and an increase in gamma-butyrobetaine (GBB) concentration in both plasma and testes extracts. However, the expression of carnitine palmitoyltransferase I in testes and testosterone concentration in plasma …

Detection of changes in mitochondrial hydrogen sulfide i n vivo in the fish model Poecilia mexicana (Poeciliidae)

2019

ABSTRACT In this paper, we outline the use of a mitochondria-targeted ratiometric mass spectrometry probe, MitoA, to detect in vivo changes in mitochondrial hydrogen sulfide (H2S) in Poecilia mexicana (family Poeciliidae). MitoA is introduced via intraperitoneal injection into the animal and is taken up by mitochondria, where it reacts with H2S to form the product MitoN. The MitoN/MitoA ratio can be used to assess relative changes in the amounts of mitochondrial H2S produced over time. We describe the use of MitoA in the fish species P. mexicana to illustrate the steps for adopting the use of MitoA in a new organism, including extraction and purification of MitoA and MitoN from tissues foll…

Binding site of different tannins on a human salivary proline-rich protein evidenced by dissociative photoionization tandem mass spectrometry

2015

Abstract The sensation of astringency is thought to originate from the interaction occurring between tannins and the salivary proline-rich proteins (PRPs). Astringency perception can be modified by the structure of tannins. Herein, we study the interactions occurring between the human salivary PRP, IB5, and three model tannins with different structure, epigallocatechin gallate and the procyanidin dimers B2 and B2 3′ O -gallate, using the coupling of mass spectrometry and VUV-synchrotron radiation. The results obtained indicate that the structure of tannins, in particular the degree of polymerization and the galloylation, does not modify the binding site on IB5 involved in the interaction.

Vapor Phase Deposited Single Junction and Tandem Perovskite Solar Cells.

2019

Efficient wide band gap double cation – double halide perovskite solar cells

2017

In this work we study the band gap variation and properties of the perovskite compound Cs0.15FA0.85Pb(BrxI1−x)3 as a function of the halide composition, with the aim of developing an efficient complementary absorber for MAPbI3 in all-perovskite tandem devices. We have found the perovskite stoichiometry Cs0.15FA0.85Pb(Br0.7I0.3)3 to be a promising candidate, thanks to its band gap of approximately 2 eV. Single junction devices using this perovskite absorber lead to a maximum PCE of 11.5%, among the highest reported for solar cells using perovskites with a band gap wider than 1.8 eV.

High voltage vacuum-deposited CH3NH3PbI3-CH3NH3PbI3 tandem solar cells

2018

The recent success of perovskite solar cells is based on two solid pillars: the rapid progress of their power conversion efficiency and their flexibility in terms of optoelectrical properties and processing methods. That versatility makes these devices ideal candidates for multi-junction photovoltaics. We report an optically optimized double junction CH3NH3PbI3–CH3NH3PbI3 tandem solar cell where the matched short-circuit current is maximized while parasitic absorption is minimized. The use of an additive vacuum-deposition protocol allows us to reproduce calculated stack designs, which comprise several charge selective materials that ensure appropriate band alignment and charge recombination…

3D photonic crystal intermediate reflectors for enhanced light-trapping in tandem solar cells

2012

The concept of 3D photonic crystals embedded in tandem solar cells as intermediate reflective layers is investigated. Numerical as well as experimental results will be presented.