Effects of fluctuations in river water level on virus removal by bank filtration and aquifer passage--a scenario analysis

Riverbank filtration is an effective process for removing pathogenic viruses from river water. Despite indications that changing hydraulic conditions during floods can affect the efficacy of riverbank filtration to remove viruses, the impact on advection and dispersion of viruses in the riverbank is not well understood. We investigated the effects of fluctuations in river water level on virus transport during riverbank filtration, considering 3-D transient groundwater flow and virus transport. Using constant removal rates from published field experiments with bacteriophages, removal of viruses with distance from the riverbank was simulated for coarse gravel, fine gravel and fine sandy gravel. Our simulations showed that, in comparison with steady flow conditions, fluctuations in river water level cause viruses to be transported further at higher concentrations into the riverbank. A 1-5 m increase in river water levels led to a 2- to 4-log (log10 reduction in concentration relative to the initial concentration in the river) increase in virus concentration and to up to 30% shorter travel times. For particular cases during the receding flood, changing groundwater flow conditions caused that pristine groundwater was carried from further inland and that simulated virus concentrations were more diluted in groundwater. Our study suggests that the adverse effect of water level fluctuations on virus transport should be considered in the simulation of safe setback distances for drinking water supplies.

Electrocatalytic degradation kinetic of 4-chlorophenol by the Pd/C gas-diffusion electrode system

A Pd/C gas-diffusion cathode which generated H2O2 through a two-electron reduction process of fed oxygen molecule was used to degrade 4-chlorophenol in an undivided electrolysis device. The kinetics of 4-chlorophenol degradation has been investigated by the electrochemical oxidation processes. By inspecting the relationship between the rate constants (k) and influencing factors, using first-order kinetics to describe the electrochemical oxidation process of 4-chlorophenol, a kinetic model of 4-chlorophenol degradation process was proposed to calculate the 4-chlorophenol effluent concentration: C = C0 exp( -3:76 × 10(-6) C(-0.5)0 J(2) M(-0.7) Q(0.17) Dt). It was found that the electrocatalytic degradation rate of 4-chlorophenol was affected by current density, electrode distance, air-feeding rate, electrolyte concentration and initial 4-chlorophenol concentration. The kinetics obtained from the experiments under corresponding electrochemical conditions could provide an accurate estimation of 4-chlorophenol effluent concentration and lead to better design of the electrochemical reactor.

Optimization of microalgal production in a shallow outdoor flume

The marine diatom Cyclotella cryptica was grown over a period of 13 months in a 48-m(2) shallow outdoor flume. The use of foil arrays at intervals of 1.2 m to effect systematic vertical mixing in the flume was found to significantly enhance microalgal production (p = 0.006). Average photosynthetic efficiencies (based on visible irradiance) with and without the foil arrays in place were 9.6 +/- 0.8 and 7.5 +/- 0.5% (+/-95% confidence intervals), respectively. A cost-benefit analysis indicated that the foil arrays were cost-effective if the value of the algae exceeded about $2.28 kg(1) of ash-free dry weight (AFDW). Parallel experiments performed in four 9.2-m(2) flumes showed that production was maximized when the cells were grown on a 2-day batch cycle between harvests rather than on a 1- or 3-day batch cycle. The optimum initial concentration (immediately after harvesting) of the algae was negatively correlated with the time interval between harvests and ranged from approximately 39 g AFDW/m(3) on a 3-day cycle to 213 g AFDW/m(3) on a 1-day cycle. The increase in production resulting from growth on a 2-day rather than a 1-day batch cycle was about 19% and was statistically significant at p = 0.0003. Growth of C. cryptica over a total period of 122 days during the 13-month study in the 48-m(2) flume under near-optimal conditions (2-day batch cycle, initial concentration 155 g AFDW/m(3)) resulted in an average production rate (+/-95% confidence interval) of 29.7 +/- 2.7 g AFDW/m(2) d.

Wireless telecardiological monitoring system for the homecare area

In following the directive "ambulant medical treatment is preferable to in hospital treatment" the home care area is becoming more and more important in western societies. In this paper a system for monitoring cardiological risk patients is presented. Special attention was paid to an automatic detection of life-threatening events and the initiation of immediate help.

Preoperative Insertion of an Intra-Aortic Balloon Pump Improved the Prognosis of High-Risk Patients Undergoing Off-Pump Coronary Artery Bypass Grafting

This study investigated the efficacy and safety of preoperative insertion of an intra-aortic balloon pump (IABP) in high-risk coronary atherosclerotic disease patients undergoing off-pump coronary artery bypass grafting (OPCAB). A total of 232 patients were recruited to the study, of whom 107 underwent percutaneous insertion of an IABP prior to OPCAB. The remaining 125 patients underwent OPCAB alone. Pre-, peri- and postoperative parameters were compared between the two groups. Preoperative insertion of an IABP was associated with a shorter stay in intensive care, decreased incidence of postoperative dialysis and acute heart failure, and a reduction in postoperative mortality compared with OPCAB alone. There were no between-group differences in terms of haematocrit level, number of distal anastomoses, volume of postoperative drainage or incidence of reoperation for bleeding and postoperative stroke/cerebrovascular accident. In conclusion, preoperative insertion of an IABP improved the prognosis of high-risk CAD patients undergoing OPCAB.

Rectal cancer: 3D dynamic contrast-enhanced MRI; correlation with microvascular density and clinicopathological features

PURPOSE

The primary aim of this prospective study was to evaluate the relationship between three-dimensional dynamic contrast-enhanced magnetic resonance (3D-DCE-MR) imaging parameters and clinicopathological features of rectal cancer and assess their potential as new radiological prognostic predictors.

MATERIALS AND METHODS

Three-dimensional DCE-MR was performed on 26 cases of pathologically proved rectal adenocarcinoma 1 week prior to operation. Data were analysed to calculate transfer constant (Ktrans), leakage space (Ve) and rate constant (Kep) of both tumour and normal rectal wall. Microvessel density (MVD) was evaluated by immunohistochemical staining of surgical specimens. All findings were analysed prospectively and correlated with tumour/node/metastasis (TNM) staging, Dukes staging, histological grading, presence of lymph node metastasis, serosal involvement and MVD.

RESULTS

Mean Ktrans, Ve and Kep for tumours were as follows: Ktrans 7.123±3.850/min, Ve 14.2±3.0%, Kep 49.446±20.404/min, revealing the significant difference between the tumour and normal rectal wall (p=0.001). There was a significant difference for Ktrans not only between patients with and without lymphatic involvement (p=0.000), but also among Dukes staging (p=0.04) and pTNM staging (p=0.03). Kep showed moderate correlation with TNM stages (r=0.479, p=0.02). Ve and MVD revealed no significant correlation with the clinicopathological findings described above (p>0.05).

CONCLUSION

Owing to the moderate and strong relationship between Ktrans and clinicopathological elements, Ktrans might be the prognostic indicator of rectal cancer. Threedimensional DCE high-resolution MR imaging provides a competing opportunity to assess contrast kinetics.

Modifying the surface charge of pathogen-sized microspheres for studying pathogen transport in groundwater

Consuming pathogen-contaminated groundwater has caused many waterborne disease worldwide. Microspheres are often used as pathogen surrogates because they can be made similar to pathogens in terms of their sizes, buoyant densities, and shapes. Laboratory studies have, however, shown that the surface charges of microspheres are very different from those of pathogens of comparable sizes, and that their attenuation and transport behaviors differ significantly to those of the pathogens mimicked. Thus, for microspheres to be better surrogates, their surface charges need to be modified. We have demonstrated that the surface charge of a microorganism can be closely mimicked by microspheres covalently coated with a protein that has a similar pHPZC to the microorganism. Using MS2 bacteriophage to test our concept, 20 nm carboxylated microspheres were covalently coated with casein. Zeta potentials as a function of pH were determined for purified MS2, casein, and uncoated and coated microspheres. The uncoated microspheres were significantly more negatively charged than MS2. The coated microspheres displayed zeta potentials and a pHPZC value similar to MS2. The modified surface charge on the microspheres was stable for at least 4 mo. Using the concept developed from this study, surrogates for many specific pathogens of concern can be developed, and the results can be corrected with pathogen die-off determined independently in the laboratory. Protein-coated microspheres could provide a new and alternative approach to investigate pathogen transport in groundwater. Future research is required to validate the surrogates' resemblances to pathogens in terms of their attenuation and transport behaviors in groundwater.

Endogenous and synthetic agonists of GPR119 differ in signalling pathways and their effects on insulin secretion in MIN6c4 insulinoma cells

Background and purpose:

GPR119 is a G protein-coupled receptor that is preferentially expressed in islet cells and mediates insulin secretion. Oleoyl-lysophosphatidylcholine and oleoylethanolamide (OEA) act as endogenous ligands for this receptor, whereas PSN375963 and PSN632408 are two recently reported synthetic agonists. In this study, we explored mechanisms underlying GPR119-induced insulin secretion. In addition, we assessed the potential utility of the synthetic agonists as tools for exploring GPR119 biology.

Experimental approach:

We examined natural and synthetic GPR119 agonist activity at GPR119 in MIN6c4 and RINm5f insulinoma cells. We evaluated insulin secretion, intracellular calcium [Ca²⁺]_i, ion channel involvement and levels of cAMP.

Key results:

We report that increases in insulin secretion induced by OEA were associated with increased cAMP and a potentiation of glucose-stimulated increases in [Ca²⁺]_i. We also demonstrate that ATP-sensitive K⁺ and voltage-dependent calcium channels were required for GPR119-mediated increases in glucose-stimulated insulin secretion. In contrast to OEA, the synthetic GPR119 agonist PSN375963 and PSN632408 have divergent effects on insulin secretion, cAMP and intracellular calcium in MIN6c4 cells.

Conclusions and implications:

The endogenous ligand OEA signals through GPR119 in a manner similar to glucagon-like peptide-1 (GLP-1) and its receptor with respect to insulin secretion, [Ca²⁺]_i and cAMP. In addition, PSN375963 and PSN632408 substantially differ from OEA and from one another. These studies suggest that the commercially available synthetic agonists, although they do activate GPR119, may also activate GPR119-independent pathways and are thus unsuitable as GPR119-specific pharmacological tools.

Real time heart ischemia detection in the smart home care system

In this paper, a novel real-time algorithm for detecting ischemia in the ECG signal is proposed. The goal of this research is to meet the requirements of some smart cardiac home care devices, which can automatically diagnose the ECG and detect the heart risks outside the hospital, especially heart ischemia without symptoms in their early stages. The algorithm is developed based on a real time R peak detector, time domain traditional ECG parameters, the advanced morphologic parameters from Karhunen-Loève transform, and the adaptive neurofuzzy logic classification. Besides, in order to improve the reliability of our algorithm, several significant constraints of the ECG signal are considered. As a result, the ischemia episodes can be detected if the ischemic alteration persists longer than one minute in the ECG signal.

New approach in developing of the algorithms for resuscitation assistance

The algorithms used in automated external defibrillators (AED) do not provide the necessary reliability of detection of fibrillation, especially in presence of artifacts. The system described in this article allows detecting different artifacts, improving the detection quality. Also an approach is suggested, to extend the AED functions to detect pulseless electrical activity. The new algorithm uses the impedance signal as an additional parameter to diagnose the cardiac arrest. The parallel analysis of ECG and impedance signals allows detecting noise, motion, respiration and hemodynamic parameters. The comparative tests of the algorithm demonstrated the excellent performance of the algorithm.

Identification of Vibrio harveyi using PCR amplification of the toxR gene

AIMS

The aim of this study was to develop an effective method for the identification of Vibrio harveyi based on using the toxR gene as a taxonomic marker.

METHODS AND RESULTS

Primers for the toxR gene were designed for specificity to V. harveyi, and incorporated in a polymerase chain reaction (PCR). The results of the PCR, which took <5 h from DNA extraction to amplification, revealed positive amplification of the toxR gene fragment in 20 V. harveyi isolates including type strains, whereas DNA from 23 other Vibrionaceae type strains and 13 Vibrio parahaemolyticus strains were negative. The detection limit of the PCR was 4.0 x 10(3) cells ml(-1). In addition, the technique enabled the recognition of V. harveyi from diseased fish.

CONCLUSIONS

The PCR was specific and sensitive, enabling the identification of V. harveyi within 5 h.

SIGNIFICANCE AND IMPACT OF THE STUDY

The PCR allowed the rapid and sensitive detection of V. harveyi.

Enhanced Basal Apoptosis in Cultured Term Human Cytotrophoblasts is Associated with a Higher Expression and Physical Interaction of p53 and Bak

We tested the hypothesis that the expression levels of p53 and the pro-apoptotic mediators from the Bcl-2 family are higher in cytotrophoblasts, when compared to cultures with abundant syncytiotrophoblasts. Cytotrophoblasts isolated from normal term human placentas were cultured in Dulbecco's Modified Eagle medium (DMEM) for 24 h, when the cytotrophoblast phenotype predominates, in DMEM for 72 h, when the syncytiotrophoblast phenotype predominates, or in Ham's-Waymouth medium or DMEM with 1.5% dimethylsulfoxide, each of which maintains the cytotrophoblast phenotype through 72 h of culture. Apoptosis was assessed by detection of cleavage products of poly-ADP-ribose polymerase, by expression of cleaved cytokeratin 18 intermediate filaments, and by assessment of caspase-3 activity. Independent of time in culture, cytotrophoblasts showed higher levels of apoptosis compared to syncytiotrophoblasts. Cytotrophoblasts also expressed a 2-fold higher level of p53, a 2-fold lower level of 60 kDa Mdm-2 protein, a 2-fold higher level of Bak, but no differences in the expression of 90 kDa Mdm-2, Bcl-2, Bcl-X(L), Mcl-1, Bax, Bad, and Bad phosphorylated at the serine(112), serine(136), or serine(155) sites, compared to the syncytiotrophoblasts. Using co-immunoprecipitation, we demonstrated a greater degree of Bak-p53 interaction in cytotrophoblasts than in syncytiotrophoblasts. We also detected Bak-Mcl-1 interaction that was no different between the two phenotypes. Among the proteins studied, enhanced p53 activity, differential Bak expression, and Bak-p53 interactions may contribute to the higher level of constitutive apoptosis in cultures of cytotrophoblasts compared to syncytiotrophoblasts.

Impact of data quality and model complexity on prediction of pesticide leaching

Accurate input data for leaching models are expensive and difficult to obtain which may lead to the use of "general" non-site-specific input data. This study investigated the effect of using different quality data on model outputs. Three models of varying complexity, GLEAMS, LEACHM, and HYDRUS-2D, were used to simulate pesticide leaching at a field trial near Hamilton, New Zealand, on an allophanic silt loam using input data of varying quality. Each model was run for four different pesticides (hexazinone, procymidone, picloram and triclopyr); three different sets of pesticide sorption and degradation parameters (i.e., site optimized, laboratory derived, and sourced from the USDA Pesticide Properties Database); and three different sets of soil physical data of varying quality (i.e., site specific, regional database, and particle size distribution data). We found that the selection of site-optimized pesticide sorption (Koc) and degradation parameters (half-life), compared to the use of more general database derived values, had significantly more impact than the quality of the soil input data used, but interestingly also more impact than the choice of the models. Models run with pesticide sorption and degradation parameters derived from observed solute concentrations data provided simulation outputs with goodness-of-fit values closest to optimum, followed by laboratory-derived parameters, with the USDA parameters providing the least accurate simulations. In general, when using pesticide sorption and degradation parameters optimized from site solute concentrations, the more complex models (LEACHM and HYDRUS-2D) were more accurate. However, when using USDA database derived parameters, all models performed about equally.

Fibrin Enhances Differentiation, but not Apoptosis, and Limits Hypoxic Injury of Cultured Term Human Trophoblasts

We hypothesized that fibrin enhances apoptosis and modulates differentiation of trophoblast in vitro. Cytotrophoblasts isolated from normal term human placentas were cultured < or =72 h in DMEM-10%-FBS on a fibrin matrix in standard or hypoxic conditions. Trophoblasts were cultured on plastic (control), type I collagen (matrix control), or dishes with fibrinogen, fibrin degradation products (FDP), thrombin, plasma fibronectin or cellular fibronectin. Apoptosis was determined by western analysis of the cleavage products of poly-ADP-ribose polymerase and cytokeratin 18 and caspase 3 activity. Cell cycle regulation was quantified by expression of proliferating cell nuclear antigen (PCNA) and p27 protein. Differentiation was determined by media level of hCG and hPL. Compared to the two controls, fibrin matrix had no effect on trophoblast apoptosis or total cell death in standard conditions. Neither fibrin nor collagen altered expression of PCNA or p27. In contrast, fibrin significantly increased the secretion of both hCG and hPL. Fibrin, but not FDP, thrombin or fibronectins, promoted hormonal differentiation. Fibrin limited the impact of a < or =8h of hypoxia on trophoblast hormone release but did not avert the effects of 24h of low oxygen and did not alter apoptosis in hypoxic trophoblast. We conclude that fibrin provides an environment conducive for trophoblast re-epithelialization of the surface of villi, where injury is marked by fibrin deposition.

A laboratory study of bacteria-facilitated cadmium transport in alluvial gravel aquifer media

Colloids, including bacteria, can dramatically accelerate the transport of heavy metals in ground water. Batch and column experiments were conducted to investigate adsorption of cadmium (Cd) onto Bacillus subtilis spores or Escherichia coli vegetative cells and Cd transport in alluvial gravel aquifer media in the presence of these bacteria. Results of the batch experiments showed that adsorption of Cd onto the bacteria was (i) positively related to solution pH, bacterial concentration, and negative surface charge, but inversely related to Cd concentration and (ii) a rate-limited nonlinear process, but adsorption onto E. coli was much less. For column influent Cd concentrations of about 4 mg/L and bacterial concentrations of > or = 10(5) colony-forming units (cfu)/mL, there was a significant increase in total Cd effluent concentrations. In comparison with controls that did not have bacteria-facilitated transport, Cd traveled 17 to 20 times faster when it traveled with mobile bacteria. However, Cd traveled mostly 2 to 3 times slower during the desorption phase under the influence of bacteria retained in the column. The difference between total and dissolved Cd concentrations was significant during Cd cotransport with B. subtilis spores, but this concentration difference was very small during Cd cotransport with E. coli, suggesting an adsorption-dominant mechanism during Cd cotransport with the spores and the possibility of Cd chelation by the dissolved membrane vesicles secreted from E. coli cell walls. Bacteria-facilitated transport of heavy metals may pose a threat to ground water quality in sites such as landfills and following land disposal of industrial and domestic effluent and sludge.

Overexpression of cyclooxygenase-2 in non-small cell lung cancer

Evidence is accumulating to suggest that the inducible isoenzyme of cyclooxygenase (COX)-2 is up-regulated in human cancers and epidemiological studies indicate that COX inhibitors may have a protective effect on the development of lung cancer. We used immunohistochemistry and Western blotting to investigate COX expression in lung tumour specimens and three lung cancer cell lines. Sixty-five archival lung tissue samples, including 46 squamous cell and 6 adenocarcinoma lung resections, and 13 small cell lung cancer (SCLC) biopsies were studied. Dense and intense cytoplasmic COX-2 staining was found in all 52 resections from non-small cell lung cancer (NSCLC). The staining was diffuse and much stronger than adjacent respiratory epithelium. COX-2 staining was relatively weak in the majority of the SCLC samples. The bronchial and bronchiolar epithelium in the surrounding normal lung structures showed uniform COX immunoreactivity with apical concentration of the stain. There was no increase in COX-1 staining in any tumour type. Western blot analysis of the cancer lines revealed significantly higher expression of COX-1 in CORL23 line and COX-2 in two NSCLC cell lines (MOR/P; A549) compared with the expression of COX-1 and COX-2 in cultured normal bronchial epithelial cells. Our findings demonstrated COX-2 overexpression in NSCLC.