Make a blog

lanounce59

1 year ago

Our results indicate that silver nanoparticles affect production and

Silver has been in use since ancient times in the form of metallic silver, and silver nitrate, and silver sulfadiazine for the treatment of burns, wounds and several bacterial infections. Silver and its compounds are known as effective antimicrobial agents (Jung et al., 2008 and Rai et al., 2009). In recent years, there has been substantial interest in the application of silver nanoparticles (AgNPs) in various fields. AgNPs have been applied in intercalation materials for electrical batteries, optical sensors, catalysts in chemical reactions, biosensors and bioactive materials, medical and pharmaceutical nanoengineering for delivery of therapeutic agents and for antimicrobial agents (Balan et al., 2007, Luo et al., 2006, Qureshi et al., 2011, Rybak et al., 2010, Thanh and Green, 2010 and Tolaymat et al., 2010). The main interest related to innovative products based on silver nanoparticles P276-00 concentrated on the management of diseases related to skin/wound infections (Ili? et al., 2009, Paladini et al., 2014 and Silva et al., 2014) and the design of antimicrobial agents and drug delivery vehicles (Kim et al., 2007, Ge et al., 2014, Narayanan and Park, 2014, Ramage et al., 2014 and Kumar and Poornachandra, 2015). AgNP as a metal possesses unique physicochemical characteristics, including a high ratio of surface area to mass, sizes in the range of nanometres (10− 9 m), high electrical and thermal conductivity, chemical stability, catalytic activity and nonlinear optical behaviour (Balan et al., 2007 and Tran et al., 2013). Heavy metals including silver, even in small concentrations can induce structural and functional changes and, thereby destroy the cell of a microorganism. At relatively high concentrations, heavy metals act as a general protoplasmic poison, inducing denaturation of proteins and nucleic acid. The antibacterial effect and possible mechanisms of AgNP actions involved in the deactivation of bacterial strains are known, often mistakenly interpreted as a basis for antifungal activity (Choi et al., 2008, Martínez-Casta?ón et al., 2008, Rai et al., 2009 and Xiu et al., 2011). However, little is known regarding the effects and mechanisms of their antifungal activity. It is most likely that, the size of the particle enhances its antimicrobial activity. Nanoparticles have a high surface to volume ratio which changes their properties when compared to non-nanoscale forms of the same material. Moreover, nanoparticles are able to penetrate biological membranes and cell walls more effectively, leading to cell death (Marambio-Jones and Hoek, 2010 and Xiu et al., 2011). The aggregation of nanoparticles drastically decreases their accessibility, resulting in insufficient functionality against microorganisms (Badawy et al., 2010 and Badawy et al., 2012). For this reason, homogeneous distribution of nanoparticles over building materials is required to guarantee better contact and reaction with microorganisms.

1 year ago

Statistical differences were observed among the study sites Mean Cs

1. Introduction
1.1. Radium contamination
Radium (226Ra) was used extensively during the 20th century predominantly in the form of luminescent paint. Waste generated from military, industrial and pharmaceutical products was regularly buried with little record of its location and inventory (Harvie, 1999). With a half-life of 1600 years, 226Ra contamination is a multigenerational issue. In the UK, a recent government report conservatively estimated there to be 150 to 250 contaminated legacy sites, whilst acknowledging there could be as many as a 1000 (DECC, 2012).

1 year ago

The entry of Cs into plants is

The ability of plants to take up 137Cs is usually represented by the transfer factor (TF) expressed as the ratio of 137Cs concentration in plant tissues to that in the soil. It is used widely to predict the concentration of radionuclides in agricultural crops and estimate the internal dose impacts on humans (Ban-Nai et al., 1999). Differences in soil-to-plant 137Cs TF values have been observed between plants (Broadley and Willey, 1997).

1 year ago

Worldwide alluvial aquifers are renowned as important groundwater resources

Worldwide, alluvial aquifers are renowned as important groundwater resources (Helena et al., 1999, García et al., 2001, Sanchez-Martos et al., 2002, Güler and Thyne, 2004, Lorite-Herrera and Jiménez-Espinosa, 2007, Al-Shaibani, 2008, Chae et al., 2009 and Faunt et al., 2009). Characterising the hydrochemical processes within these LEE011 alluvial aquifers is vital to understanding both the nature and extent of the groundwater resource, as well as its relationships with its surrounding environment, including influences of recharge and anthropogenic activities.

1 year ago

TIC10 Table nbsp shows the observed MDLs for target analytes in

The majority of analyte MDLs in seawater filtrate were < 5 pg L− 1. Musks exhibited the highest MDLs (3.2 to 51.1 pg L− 1). MDLs of other analytes ranged from 0.4 pg L− 1 (anti-DP) to 34.3 pg L− 1 (endrin). The MDL of MTCS was relatively low (0.7 pg L− 1).

1 year ago

More striking inconsistencies in the SS hysteresis patterns between scales

More striking inconsistencies in the SS hysteresis patterns between scales are observed when the occurrence of anti-clockwise hysteresis is examined. These event dynamics are extremely infrequently reported at Stations A and B. However, at Station C these account for 22% of the events, and 2% of the storm generated sediment flux. The generation of these sediment dynamics is likely the result of the JIB-04 sediment delivery pathway being a) extensive with a source distal to the main channel (Eder et al., 2010 and Marttila and Kl?ve, 2010), or b) slow-moving (Sadeghi et al., 2008). Given that these dynamics are observed at the outlet station only, during low magnitude events and following relatively dry antecedent conditions, it is highly unlikely that contributing area expansion, the capturing of headwater zones and widespread hydrological connectivity would result in significant contributions from distal sources (Ba?a, 2008, Giménez et al., 2012, Marttila and Kl?ve, 2010 and Webb and Walling, 1982). Rather, given the event characteristics, sub-surface flow is anticipated to be a significant contributor to both the storm-water discharge and, potentially, the material flux (e.g., Deasy et al., 2009 and Russell et al., 2001). Sub-surface particulate fluxes are likely to occur following soil pipe erosion (Verachtert et al., 2011), or detachment at the surface by raindrop impact which is subsequently delivered through soil macro-pores or sub-surface drains (Pilgrim and Huff, 1983). Although these sub-surface processes may be important during low magnitude events, as storm intensity increases, additional pathways of sediment movement become progressively important (Sayer et al., 2006), limiting the occurrence of anti-clockwise hysteresis events to low magnitude runoff events.

1 year ago

This research was conducted in the upper reaches of

Improved grassland dominates the catchment (76% by area), along with acid grassland (10%) and arable land (6%), with 2.88 livestock units (LU) ha− 1 (cattle and sheep). The average Olsen P concentration from across 38 fields (14% of catchment) is 23.6 mg kg− 1 (σ = 9.9 mg kg− 1) with a range of 8–46 mg kg− 1.