Compact and portable quartz-enhanced photoacoustic spectroscopy sensor for carbon monoxide environmental monitoring in urban areas.

We report on the realization, calibration, and test outdoor of a 19-inches rack 3-units sized Quartz Enhanced Photoacoustic Spectroscopy (QEPAS) trace gas sensor designed for real-time carbon monoxide monitoring in ambient air. Since CO acts as a slow energy relaxer when excited in the mid-infrared spectral region, its QEPAS signal is affected by the presence of relaxation promoters, such as water vapor, or quenchers like molecular oxygen. We analyzed in detail all the CO relaxation processes with typical collisional partners in an ambient air matrix and used this information to evaluate oxygen and humidity-related effects, allowing the real CO concentration to be retrieved.

Quartz-enhanced photoacoustic spectroscopy exploiting low-frequency tuning forks as a tool to measure the vibrational relaxation rate in gas species.

We demonstrated that quartz-enhanced photoacoustic spectroscopy (QEPAS) is an efficient tool to measure the vibrational relaxation rate of gas species, employing quartz tuning forks (QTFs) as sound detectors. Based on the dependence of the QTF resonance frequency on the resonator geometry, a wide range of acoustic frequencies with narrow detection bandwidth was probed. By measuring the QEPAS signal of the target analyte as well as the resonance properties of different QTFs as a function of the gas pressure, the relaxation time can be retrieved.

Potent protection of gallic acid against DNA oxidation: results of human and animal experiments.

Gallic acid (3,4,5-trihydroxybenzoic acid, GA) is a constituent of plant derived foods, beverages and herbal remedies. We investigated its DNA protective properties in a placebo controlled human intervention trial in single cell gel electrophoresis experiments. Supplementation of drinking water with GA (12.

Impact of spinach consumption on DNA stability in peripheral lymphocytes and on biochemical blood parameters: results of a human intervention trial.

Introduction: A controlled intervention trial was conducted to assess the impact of spinach consumption on DNA stability in lymphocytes and on health-related biochemical parameters.

Methods: The participants (n = 8) consumed homogenised spinach (225 g/day/person) over a period of 16 days. DNA migration was monitored in single cell gel electrophoresis-comet assays under standard conditions, which reflect single- and double-strand breaks, after treatment of nuclei with lesion-specific enzymes (formamidopyrimidine glycosylase, FPG and endonuclease III, ENDO III) and after treatment of intact cells with H(2)O(2) before, during and after intervention.

Impact of paper filtered coffee on oxidative DNA-damage: results of a clinical trial.

Coffee is among the most frequently consumed beverages worldwide and epidemiological studies indicate that its consumption is inversely related to the incidence of diseases in which reactive oxygen species (ROS) are involved (liver cirrhosis, certain forms of cancer and neurodegenerative disorders). It has been postulated that antioxidant properties of coffee may account for this phenomenon. To find out if consumption of paper filtered coffee which is the most widely consumed form in Central Europe and the US protects humans against oxidative DNA-damage, a controlled intervention trial with a cross-over design was conducted in which the participants (n=38) consumed 800ml coffee or water daily over 5 days.

Antioxidant responses to an acute ultra-endurance exercise: impact on DNA stability and indications for an increased need for nutritive antioxidants in the early recovery phase.

Antioxidant requirements have neither been defined for endurance nor been defined for ultra-endurance athletes. To verify whether an acute bout of ultra-endurance exercise modifies the need for nutritive antioxidants, we aimed (1) to investigate the changes of endogenous and exogenous antioxidants in response to an Ironman triathlon; (2) to particularise the relevance of antioxidant responses to the indices of oxidatively damaged blood lipids, blood cell compounds and lymphocyte DNA and (3) to examine whether potential time-points of increased susceptibility to oxidative damage are associated with alterations in the antioxidant status. Blood that was collected from forty-two well-trained male athletes 2 d pre-race, immediately post-race, and 1, 5 and 19 d later was sampled.

Instant coffee with high chlorogenic acid levels protects humans against oxidative damage of macromolecules.

Scope: Coffee is among the most frequently consumed beverages. Its consumption is inversely associated to the incidence of diseases related to reactive oxygen species; the phenomenon may be due to its antioxidant properties. Our primary objective was to investigate the impact of consumption of a coffee containing high levels of chlorogenic acids on the oxidation of proteins, DNA and membrane lipids; additionally, other redox biomarkers were monitored in an intervention trial.

DNA damage in response to an Ironman triathlon.

The major aims of this study were to investigate the effect of an Ironman triathlon on DNA migration in the single cell gel electrophoresis assay, apoptosis and necrosis in the cytokinesis-block micronucleus cytome assay with lymphocytes and on changes of total antioxidant capacity in plasma. Blood samples were taken 2 days (d) before, within 20 min, 1 d, 5 d and 19 d post-race. The level of strand breaks decreased (p<0.

Inhalative exposure to vanadium pentoxide causes DNA damage in workers: results of a multiple end point study.

Background: Inhalative exposure to vanadium pentoxide (V(2)O(5)) causes lung cancer in rodents.

Objective: The aim of the study was to investigate the impact of V(2)O(5) on DNA stability in workers from a V(2)O(5) factory.

Methods: We determined DNA strand breaks in leukocytes of 52 workers and controls using the alkaline comet assay.

DNA-protective effects of sumach (Rhus coriaria L.), a common spice: results of human and animal studies.

Sumach (Rhus coriaria L.) is widely used as a spice. The aim of this study was the investigation of its DNA-protective effects in humans and animals.

Use of single cell gel electrophoresis assays for the detection of DNA-protective effects of dietary factors in humans: recent results and trends.

This article summarises the results of human dietary intervention trials employing the comet assay (single cell gel electrophoresis, SCGE), which have been published in the last few years (i.e., between 2005 and 2008) and describes new trends and developments as well as current problems concerning the design of intervention trials and the interpretation of the results.

Use of conventional and -omics based methods for health claims of dietary antioxidants: a critical overview.

This article describes the principles and limitations of methods used to investigate reactive oxygen species (ROS) protective properties of dietary constituents and is aimed at providing a better understanding of the requirements for science based health claims of antioxidant (AO) effects of foods. A number of currently used biochemical measurements aimed of determining the total antioxidant capacity and oxidised lipids and proteins are carried out under unphysiological conditions and are prone to artefact formation. Probably the most reliable approaches are measurements of isoprostanes as a parameter of lipid peroxidation and determination of oxidative DNA damage.

Consumption of Brussels sprouts protects peripheral human lymphocytes against 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and oxidative DNA-damage: results of a controlled human intervention trial.

To find out if the cancer protective effects of Brussels sprouts seen in epidemiological studies are due to protection against DNA-damage, an intervention trial was conducted in which the impact of vegetable consumption on DNA-stability was monitored in lymphocytes with the comet assay. After consumption of the sprouts (300 g/p/d, n = 8), a reduction of DNA-migration (97%) induced by the heterocyclic aromatic amine 2-amino-1-methyl-6-phenyl-imidazo-[4,5-b]pyridine (PhIP) was observed whereas no effect was seen with 3-amino-1-methyl-5H-pyrido[4,3-b]-indole (Trp-P-2). This effect protection may be due to inhibition of sulfotransferase 1A1, which plays a key role in the activation of PhIP.

Proteome alterations induced in human white blood cells by consumption of Brussels sprouts: Results of a pilot intervention study.

Epidemiological studies indicate a correlation of cruciferous vegetables consumption with reduced incidence of cancer. This study was designed to investigate molecular mechanisms, which may help to understand the beneficial effects of Brussels sprout consumption. In order to avoid the limitations of in vitro model systems, we performed a dietary intervention study with five participants.

Coffee consumption induces GSTP in plasma and protects lymphocytes against (+/-)-anti-benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide induced DNA-damage: results of controlled human intervention trials.

A number of animal studies indicate that coffee protects against chemical induction of cancer; also human studies suggest that coffee consumption is inversely related with the incidence of different forms of cancer. The protective effects were attributed to induction of glutathione-S-transferases (GSTs) and aim of the present human study was to find out if coffee causes induction of GSTs and protects against DNA-damage caused by (+/-)-anti-B[a]P-7,8-dihydrodiol-9,10-epoxide (BPDE), the DNA-reactive metabolite of benzo(a)pyrene. Ten participants consumed 1L unfiltered coffee/d over 5 days.