ANTIBACTERIAL AND PHOTOCATALYTIC ABILITY OF THE Ag/TiO2 COATING ON THE GLASS SURFACE.

The coating on the glass surface was made by heating the mixture of resinate Ag and tetra-n-butyl orthotitanate (TBO) at 570 oC for 1 hour. The characteristics and structure of the mixture Ag/TiO2 with the content of Ag : TiO2 from 0 – 8 (% mol) were studied by the methods such as XRD, FTIR, UV-viz, SEM, EDS. The research results of antibacterial ability and the degradation of blue methylene (MB) were shown that this coating can be used for antibacterial and photocatalytic abilit

Pharmacology and clinical drug candidates in redox medicine

SIGNIFICANCE Oxidative stress is suggested to be a disease mechanism common to a wide range of disorders affecting human health. However, so far, the pharmacotherapeutic exploitation of this, for example, based on chemical scavenging of pro-oxidant molecules, has been unsuccessful. Recent Advances: An alternative emerging approach is to target the enzymatic sources of disease-relevant oxidative stress. Several such enzymes and isoforms have been identified and linked to different pathologies. For some targets, the respective pharmacology is quite advanced, that is, up to late-stage clinical development or even on the market; for others, drugs are already in clinical use, although not for indications based on oxidative stress, and repurposing seems to be a viable option. CRITICAL ISSUES For all other targets, reliable preclinical validation and drug ability are key factors for any translation into the clinic. In this study, specific pharmacological agents with optimal pharmacokinetic profiles are still lacking. Moreover, these enzymes also serve largely unknown physiological functions and their inhibition may lead to unwanted side effects. FUTURE DIRECTIONS The current promising data based on new targets, drugs, and drug repurposing are mainly a result of academic efforts. With the availability of optimized compounds and coordinated efforts from academia and industry scientists, unambiguous validation and translation into proof-of-principle studies seem achievable in the very near future, possibly leading towards a new era of redox medicine

Non-canonical chemical feedback self-limits nitric oxide-cyclic GMP signaling in health and disease

Nitric oxide (NO)-cyclic GMP (cGMP) signaling is a vasoprotective pathway therapeutically targeted, for example, in pulmonary hypertension. Its dysregulation in disease is incompletely understood. Here we show in pulmonary artery endothelial cells that feedback inhibition by NO of the NO receptor, the cGMP forming soluble guanylate cyclase (sGC), may contribute to this. Both endogenous NO from endothelial NO synthase and exogenous NO from NO donor compounds decreased sGC protein and activity. This effect was not mediated by cGMP as the NO-independent sGC stimulator, or direct activation of cGMP-dependent protein kinase did not mimic it. Thiol-sensitive mechanisms were also not involved as the thiol-reducing agent N-acetyl-L-cysteine did not prevent this feedback. Instead, both in-vitro and in-vivo and in health and acute respiratory lung disease, chronically elevated NO led to the inactivation and degradation of sGC while leaving the heme-free isoform, apo-sGC, intact or even increasing its levels. Thus, NO regulates sGC in a bimodal manner, acutely stimulating and chronically inhibiting, as part of self-limiting direct feedback that is cGMP independent. In high NO disease conditions, this is aggravated but can be functionally recovered in a mechanism-based manner by apo-sGC activators that re-establish cGMP formatio

Reactive oxygen-related diseases: therapeutic targets and emerging clinical indications

SIGNIFICANCE Enhanced levels of reactive oxygen species (ROS) have been associated with different disease states. Most attempts to validate and exploit these associations by chronic antioxidant therapies have provided disappointing results. Hence, the clinical relevance of ROS is still largely unclear. RECENT ADVANCES We are now beginning to understand the reasons for these failures, which reside in the many important physiological roles of ROS in cell signaling. To exploit ROS therapeutically, it would be essential to define and treat the disease-relevant ROS at the right moment and leave physiological ROS formation intact. This breakthrough seems now within reach. CRITICAL ISSUES Rather than antioxidants, a new generation of protein targets for classical pharmacological agents includes ROS-forming or toxifying enzymes or proteins that are oxidatively damaged and can be functionally repaired. FUTURE DIRECTIONS Linking these target proteins in future to specific disease states and providing in each case proof of principle will be essential for translating the oxidative stress concept into the clinic. Antioxid. Redox Signal. 23, 1171-1185

Effect of time and temperature on the survival rate of mouse sperm (Mus musculus var. Albino) in short-term preservation without cryoprotectant agents

In this study, we studied the use of physiological saline solution (NaCl 0,9%) or dulbecco’s phosphatebuffered saline (D-PBS) for mature sperms short-term preservation. After being collected from epididymides, sperms were adjusted to desired concentration (2x106 sperms/ml) with NaCl 0.9% solution or D-PBS solution (the dishes containing sperms were covered by mineral oil) and stored at 4oC, iooC and room temperature (RT/26oC

ARSENIC POLLUTION IN GROUNDWATER IN RED RIVER DELTA, VIETNAM : SITUATION AND HUMAN EXPOSURE

Joint Research on Environmental Science and Technology for the Eart

Spatial variations of arsenic in groundwater from a transect in the Northwestern Hanoi

Arsenic contamination of groundwater is a major health problem and has been a growing concern in the last decade in several regions of the world, especially in South and Southeast Asia, including the Red River delta, Vietnam. Regional groundwater studies have been carried out in the vicinity of Hanoi, on the banks of the Red River and its adjacent floodplains. In this study, the groundwater from a transect in the Northwestern area of Hanoi was examined. The results showed that 28.8% the wells of the B-B’ transect exceed the WHO guideline value for arsenic concentration in drinking water. The arsenic concentrations varied in a wide range from point to point, with the highest concentration found at Van Phuc and the lowest one found at Cam Yen. They also varied accordingly to the depth.References Anawar H.M., Akai J., Sakugawa H., Sakugawa H., 2004. Mobilization of arsenic from subsurface sediments by effect of bicarbonate ions in groundwater. Chemosphere, 54, 753-762. Appelo C.A.J., Postma D., 2004. Geochemistry, Groundwater and Pollution, second edition. Berg M., Tran H.C., Nguyen T.C., Pham H.V., Schertenleib R., Giger W., 2001. Arsenic contamination of groundwater and drinking water in Vietnam: A human health threat. Environmental Science Technology, 35(13), 2621-2626. Berg M., Stengel C., Pham T.K.T., Pham H.V., Sampson M.L., Leng M., Samreth S., Fredericks D., 2007. Magnitude of arsenic pollution in the Mekong and Red River Delta - Cambodia and Vietnam. Science of the Total Environment, 372, 413-425. Chowdhury U.K., Biswas B.K., Chowdhury T.R., Samanta G., Mandal B.K., Basu G.C., Chanda C.R., Lodh D., Saha K.C., Mukherjee S.K., Roy S., Kabir S., Quamruzzaman Q., Chakraborti D., 2000. Groundwater Arsenic Contamination in Bangladesh and West Bengal, India. Environmental Health Perpectives, 108(5), 393-397. Eiche E., Neumann T., Berg M., Weinman B., Van Geen A., Norra S., Berner Z., Pham T.K.T., Pham H.V., Stuben D., 2008. Geochemical processes underlying a sharp contrast in groundwater arsenic concentrations in a village on the Red River delta, Vietnam. Applied Geochemistry, 23, 3143-3154. Fendorf S., Michael H.A., Van Geen A., 2010. Spatial and temporal variations of groundwater arsenic in South and Southeast Asia. Science, 328, 1123. Doi: 10.1126/Science.1172974. General Statics Office of Vietnam, 2015. Regional statistics of Area, Population and Population density. McArthur J.M., Ravenscroft P., Safuilla S., Thirlwall M.F., 2001. Arsenic in groundwater: Testing pollution mechanisms for sedimentary aquifers in Bangladesh. Water Resources Research, 31(1), 109-117. Postma D., Larsen F., Nguyen T.M.H., Mai T.D., Pham H.V., Pham Q.N., Jessen S., 2007. Arsenic in groundwater of the Red River floodplain, Vietnam: Controlling geochemical processes and reactive transport modeling. Geochimica et Cosmochimica Acta, 71, 5054-5071. Postma D., Larsen F., Nguyen T.T., Pham T.K.T., Jakobsen R., Pham Q.N., Tran V.L., Pham H.V., Murray A.S., 2012. Groundwater arsenic concentrations in Vietnam controlled by sediment age. Nature GeoScience. Doi: 10.1038/NGEO1540. Smedley P.L., Kinniburgh D.G., 2002. A review of the source, behavior and distribution of arsenic in natural waters. Applied Geochemistry, 17, 517-568. Smedley P.L., 2006. Sources and distribution of arsenic in groundwater and aquifers. In T. Appelo (Ed.), Arsenic in Groundwater - A World Problem, 4-33. Van Geen A., Bostick B.C., Pham T.K.T., Vi M.L., Nguyen N.M., Dao M.P., Pham H.V., Radloff K., Aziz A., Mey J.L., Stahl M.O., Harvey C.H., Oates P., Weinman B., Stengel C., Frei F., Kipfer R., Berg M., 2013. Retardation of arsenic transport through a Pleistocene aquifer. Nature, 501, 204-208. Van Geen, A., Zheng Y., Versteeg R., Stute M., Horneman A., Dhar R., Steckler M., Gelman A., Small C., Ahsan H., Graziano J.H., Hussain I., Ahmed K.M., 2003. Spatial variability of arsenic in 6000 tube wells in a 25 km2 area of Bangladesh. Water Resources Research, 39(5), 1140. Doi:10.1029/2002WR001617. World Health Organization, 2011. Guidelines for drinking-water quality, fourth edition. Winkel L.H.E., Pham T.K.T., Vi M.L., Stengel C., Amini M., Nguyen T.H., Pham H.V., Berg M., 2011. Arsenic pollution of groundwater in Vietnam exacerbated by deep aquifer exploitation for more than a century. PNAS, 108(4), 1246-1251

Retardation of arsenic transport through a Pleistocene aquifer

Groundwater drawn daily from shallow alluvial sands by millions of wells over large areas of south and southeast Asia exposes an estimated population of over a hundred million people to toxic levels of arsenic. Holocene aquifers are the source of widespread arsenic poisoning across the region. In contrast, Pleistocene sands deposited in this region more than 12,000 years ago mostly do not host groundwater with high levels of arsenic. Pleistocene aquifers are increasingly used as a safe source of drinking water and it is therefore important to understand under what conditions low levels of arsenic can be maintained. Here we reconstruct the initial phase of contamination of a Pleistocene aquifer near Hanoi, Vietnam. We demonstrate that changes in groundwater flow conditions and the redox state of the aquifer sands induced by groundwater pumping caused the lateral intrusion of arsenic contamination more than 120 metres from a Holocene aquifer into a previously uncontaminated Pleistocene aquifer. We also find that arsenic adsorbs onto the aquifer sands and that there is a 16–20-fold retardation in the extent of the contamination relative to the reconstructed lateral movement of groundwater over the same period. Our findings suggest that arsenic contamination of Pleistocene aquifers in south and southeast Asia as a consequence of increasing levels of groundwater pumping may have been delayed by the retardation of arsenic transport