MnSOD expression is increased in metastatic gastric cancer

BACKGROUND

Manganese superoxide dismutase (MnSOD) catalyzes the scavenging of superoxide radicals in order to protect cells from the damage caused by reactive oxygen species. Previous studies implicate MnSOD in cancer progression, but its role in gastric cancer metastasis is poorly understood.

MATERIALS AND METHODS

To determine whether MnSOD expression correlates with gastric cancer metastasis, we compared immunostaining for MnSOD in the primary tumors of gastric cancer patients with (n = 15) and without (n = 9) nodal metastases. These patients were matched for risk factors associated with gastric cancer metastasis, such as tumor site, depth, and grade. MnSOD expression was scored positive (increased) if MnSOD staining of tumor cells was more intense than MnSOD staining in corresponding normal gastric epithelial cells. Statistical analyses were via chi(2) test and Fisher's exact test.

RESULTS

MnSOD expression was increased in 14 of the 15 (93%) metastatic tumors, compared to only 4 of the 9 (44%) nonmetastatic tumors (P = 0.015). There was no significant difference in staining when the two groups were compared based on tumor grade (P = 0.70) or depth of tumor cell invasion (T stage) (P = 0.22).

CONCLUSIONS

MnSOD expression is upregulated in the primary tumors of gastric cancer patients with lymph node metastases. This finding supports an involvement of MnSOD and possibly the reactive oxygen status of the gastric tumor microenvironment in gastric cancer metastasis.

Macroporous Silicon Electrical Sensor for DNA Hybridization Detection

Macroporous silicon (pore diameter 1-2 microm) was used in an electrical sensor for real time, label free detection of DNA hybridization. Electrical contacts were made exclusively on the back side of the substrate, which allowed complete exposure of the porous layer to DNA. Hybridization of a DNA probe with its complementary sequence produced a reduction in the impedance and a shift in the phase angle resulting from a change in dielectric constant inside the porous matrix and a modification of the depletion layer width in the crystalline silicon structure. The effect of the DNA charge on the response was corroborated using peptide nucleic acid (PNA), an uncharged analog of DNA. The sensitivity and selectivity of the device were characterized and the sensing properties of the porous layer alone were investigated using self-supporting macroporous silicon membranes.

Lateral gas transport in soil adjacent to an old landfill: factors governing emissions and methane oxidation

Field investigations of lateral gas transport and subsequent emissions in soil adjacent to an old landfill in Denmark have been conducted during a one-year period. A significant seasonal variation in the emissions with high carbon dioxide and low methane fluxes in the summer (May to October) was observed. This was attributed to methane oxidation. Diumal measurements during a drop in barometric pressure showed that the fluxes of landfill gas changed dramatically within a very short time. The concentrations and the soil moisture content in the upper part of the soil profile had significant influence on the fluxes, as did the distance from the landfill border, temperature, barometric pressure and the pressure gradient. Statistical analyses proved that soil moisture described the largest part of the variation. No methane at all emitted during the summer. Calculations and isotope analyses showed that very high fractions of the laterally migrating methane were oxidised.

Lateral gas transport in soil adjacent to an old landfill: factors governing gas migration

Field experiments investigating lateral gas transport in soil adjacent to an old landfill in Denmark during a one-year period were conducted. A significant seasonal variation, with low concentrations of methane and high concentrations of carbon dioxide in the summer, caused by methane oxidation was observed. There was a good correlation between pressure above the barometric pressure and the methane concentration in the soil, indicating that advective flow was the controlling process. This was confirmed by calculations. Diurnal measurement during a drop in barometric pressure showed that lateral migration of landfill gas was a very dynamic system and the concentrations of LFG at a specific place and depth changed dramatically within a very short time. The experiments showed that change in barometric pressure was an important factor affecting gas migration at the Skellingsted landfill in Denmark.

Composition of leachate from old landfills in Denmark

The Danish counties have performed numerous investigations of old landfills. These investigations have been presented in several reports, but no comprehensive summary of the findings has been carried out. The objective of this study was to evaluate the typical composition of leachates from old smaller landfills by a comprehensive review of the investigations carried out by the counties. In total 106 landfills were selected by criteria avoiding dilution effects. A database was constructed using a standard program. Statistical evaluations showed that the leachate concentrations in general decreased with the age of the landfill, and that the leachate concentrations were lower than found in other similar studies.

Lateral gas transport in soil adjacent to an old landfill: factors governing emissions and methane oxidation

Field investigations of lateral gas transport and subsequent emissions in soil adjacent to an old landfill in Denmark were conducted during a 1-year period. A significant seasonal variation in the emissions with high carbon dioxide and low methane fluxes in the summer (May to October) was observed. This was attributed to methane oxidation. Diurnal measurements during a drop in barometric pressure showed that the fluxes of landfill gas changed dramatically within a very short time. The concentrations and the soil moisture content in the upper part of the soil profile had significant influence on the fluxes, as did the distance from the landfill border, temperature, barometric pressure and the pressure gradient. Statistical analyses proved that soil moisture described the largest part of the variation. No methane is emitted during the summer. Calculations and isotope analyses showed that very high fractions of the laterally migrating methane were oxidised.

Predicting the impact and duration of persistent and mobile organic compounds in groundwater systems using a contaminant mass discharge approach

This study investigated methods for predicting the duration and impact on groundwater quality from persistent and mobile organic compounds (PMOCs) at a drinking water well field affected by multiple contaminant sources. The fungicide metabolite N,N-dimethylsulfamide (DMS), which frequently occurs above the Danish groundwater quality criterion (0.1 μg/L), was used as an example. By combining contaminant mass discharge (CMD) estimations, modeling, and groundwater dating, a number of important discoveries were made. The current center of contaminant mass was located near the source area. The CMD at the well field was predicted to peak in 2040, and an effect from the investigated sources on groundwater quality could be expected until the end of the 21st century. A discrepancy in the current CMD at the well field and the estimated arrival time from the studied source area suggested an additional pesticide source, which has not yet been thoroughly investigated. The presence of the unknown source was supported by model simulations, producing an improved mass balance after inclusion of a contaminant source closer to the well field. The approach applied here was capable of predicting the duration and impact of DMS contamination at a well field at catchment scale. It furthermore shows potential for identification and quantification of the contribution from individual sources, and is also applicable for other PMOCs. Predicting the duration of the release and impact of contaminant sources on abstraction wells is highly valuable for water resources management and authorities responsible for contaminant risk assessment, remediation, and long-term planning at water utilities.

Lateral gas transport in soil adjacent to an old landfill: factors governing gas migration

Field experiments investigating lateral gas transport in soil adjacent to an old landfill in Denmark during a one-year period were conducted. A significant seasonal variation, with low concentrations of methane and high concentrations of carbon dioxide in the summer, caused by methane oxidation was observed. There was a good correlation between pressure above the barometric pressure and the methane concentration in the soil, indicating that advective flow was the controlling process. This was confirmed by calculations. Diurnal measurement during a drop in barometric pressure showed that lateral migration of landfill gas was a very dynamic system and the concentrations of LFG at a specific place and depth changed dramatically within a very short time. The experiments showed that change in barometric pressure was an important factor affecting gas migration at the Skellingsted landfill in Denmark.

Long-term leaching through clayey till of N,N-dimethylsulfamide, a Persistent and Mobile Organic Compound (PMOC)

Environmental pollution with Persistent and Mobile Organic Compounds (PMOC) from anthropogenic activities is an increasing cause for concern. These compounds are readily leached to groundwater aquifers and are likely to resist degradation, putting pressure on groundwater resources. Pesticides can form PMOCs upon degradation in the environment. The PMOC N,N-dimethylsulfamide (DMS) was the most frequently detected pesticide metabolite in Danish drinking water wells in 2020, although the pesticidal use of the last parent compound (tolylfluanid) ended in 2007. This study aimed to improve the understanding of the leaching of the PMOC DMS from clayey tills by combining a review of compound properties, sources and use, comprehensive field observations and numerical flow and solute transport modeling. The modeling explored the mechanisms of DMS retention during vertical transport in clayey till and the fingerprint in the underlying aquifer. The results were supported by detailed field observations at an agricultural site with strawberry production. Porewater samples were collected from clayey till to a depth of 12 m bgs by a custom designed installation method of suction cups. Groundwater sampling (249 samples) was designed to provide vertical concentration profiles at various distances from the presumed sources. The review of properties showed that the parent compounds and intermediates degrade quickly in topsoil, releasing the highly persistent and mobile DMS. We tested the effect of fractures on transport with different hydraulic apertures and a scenario without fractures by numerical modeling. The results showed that the presence of fractures can smooth the breakthrough curve below the clayey till, leading to faster breakthrough, lower maximum concentration, and several decades of prolonged leaching in simulations with the largest aperture (20 μm). The fracture-matrix interaction is a possible explanation for the observed delay of leaching from clayey till. The vertical concentration profiles in groundwater were used for identifying the sources at the field site and testing source strengths. Assigning one point source (200 μg/L) and two diffuse sources (40-50 μg/L) to the model produced vertical concentration profiles that compared well with observed field data in clayey till and the aquifer. All results were integrated into a conceptual model for the environmental fate of PMOCs in soil and groundwater. The findings of this study imply that the presence of fractures in clayey till should be considered in conceptual site models, since they can substantially prolong the leaching of PMOCs to groundwater. The integration of comprehensive field investigations and numerical modeling is key to understand the fate of PMOCs in complex field systems with different source types. Together with widespread occurrences of PMOCs in groundwater systems, the results highlight the need for improved approval procedures for pesticides and biocides which considers their persistent and mobile metabolites.

Increasing market opportunities for renewable energy technologies with innovations in aquifer thermal energy storage

Heating and cooling using aquifer thermal energy storage (ATES) has hardly been applied outside the Netherlands, even though it could make a valuable contribution to the energy transition. The Climate-KIC project "Europe-wide Use of Energy from aquifers" - E-USE(aq) - aimed to pave the way for Europe-wide application of ATES, through the realization and monitoring of six ATES pilot plants across five different EU countries. In a preceding paper, based on preliminary results of E-USE(aq), conclusions were already drawn, demonstrating how the barriers for this form of shallow geothermal energy can be overcome, and sometimes even leveraged as opportunities. Based on final pilot project results, key economic and environmental outcomes are now presented. This paper starts with the analysis of specific technological barriers: unfamiliarity with the subsurface, presumed limited compatibility with existing energy provision systems (especially district heating), energy imbalances and groundwater contamination. The paper then shows how these barriers have been tackled, using improved site investigation and monitoring technologies to map heterogeneous subsoils. In this way ATES can cost-efficiently be included in smart grids and combined with other sources of renewable (especially solar) energy, while at the same time achieving groundwater remediation. A comparative assessment of economic and environmental impacts of the pilots is included, to demonstrate the sustainability of ATES system with different renewables and renewable-based technologies. The paper concludes with an assessment of the market application potential of ATES, including in areas with water scarcity, and a review of climate beneficial impact.

Comparative SEM and Cathodoluminescence Microanalysis of Porous GaP Structures

Electron microscopy and cathodoluminescence (CL) microanalysis were used for a comparative study of porous layers fabricated by electrochemical etching of n-GaP substrates in a sulfuric acid solution. Both the CL and morphology of porous layers were found to depend upon the anodic current density. At high current density (100 mA/cm2) anodization leads to the formation of so-called current-line oriented pores and an increase in the CL intensity. We observed self-induced voltage oscillations giving rise to a synchronous modulation of the diameter of pores and CL intensity. When the current density decreased to values as low as 1 mA/cm2 the pores began to grow along <111> crystallographic directions and the CL intensity was observed to be lower than that of bulk GaP.