Evaluation of silver nanoparticle acute and chronic effects on freshwater amphipod (Hyalella azteca).

Silver nanoparticles (AgNPs) are known to cause ecotoxic effects, but there are no existing derived ambient water quality criteria (AWQC) for these nanomaterials to protect freshwater aquatic life due to insufficient toxicological data. We exposed Hyalella azteca to silver nitrate, citrate-coated AgNPs (citrate-AgNPs), and polyvinylpyrrolidone-coated AgNPs (PVP-AgNPs) in a 10-day and 28-day water-only static renewal system with clean sand as a substrate for the amphipods and compared their point estimates with the United States Environmental Protection Agency (USEPA) AWQC for silver. We observed that all treatments decreased the survival, growth, and biomass of H.

Evaluation of active matrix metalloproteinase-8 (aMMP-8) chair-side test as a diagnostic biomarker in the staging of periodontal diseases.

Objective: There is a need for a reliable complementary diagnostic tool that ideally helps to screen, differentiate sites, activities of and predict future periodontal tissue destruction. The purpose of this cross-sectional study was to investigate the screening and prevention potential of the chair-side/point-of-care (PoC) diagnostic test of salivary active matrix metalloproteinase-8 (aMMP-8) levels at different stages of periodontal disease and periodontal health.

Material & Methods: 80 individuals were included in this study; 18 with periodontitis stage 3 (P-Stage III), 19 with periodontitis stage-4 (P-Stage IV), 21 with gingivitis, and 22 with clinically healthy periodontium (H).

Storm sampling to assess inclement weather impacts on water quality in a karst watershed: Sinking Creek, Watauga watershed, East Tennessee.

Sinking Creek (HUC 06010103046), in the Watauga watershed of northeast Tennessee, is impaired due to Escherichia coli. To assess how E. coli and other water quality parameters fluctuated during storm events, water samples were collected with automated samplers during eight storms at two locations: Sinking Creek and a feeder spring.

Emerging environmental contaminants (silver nanoparticles) altered the catabolic capability and metabolic fingerprinting of microbial communities.

Microbial community functional diversity enhances the degradation of organic matter and pollutants in the environment, but there is a growing concern that these ecosystem services may be altered by the introduction of emerging environmental contaminants including silver nanoparticles (AgNPs) into aquatic systems. We added 0, 25, 50, 75, 100, and 125 mg L (nominal concentrations) of citrate-AgNP and polyvinylpyrrolidone-AgNP (PVP-AgNP) each to freshwater sediment and examined their antimicrobial effects on microbial communities using community-level physiological profiling. The results showed that citrate-AgNP decreased the overall microbial catabolic activity by 80% from 1.

Antimicrobial properties of silver nanoparticles may interfere with fecal indicator bacteria detection in pathogen impaired streams.

Silver nanoparticles (AgNPs) are expected to enter aquatic systems, but there are limited data on how they might affect microbial communities in pathogen impaired streams. We examined microbial community responses to citrate-AgNP (10.9 ± 0.

Peri-Implant Sulcus Fluid (PISF) Matrix Metalloproteinase (MMP) -8 Levels in Peri-Implantitis.

Introduction: Matrix Metalloproteinase (MMP) -8 plays crucial role in pathogenesis of periodontitis and is also a possible biomarker candidate in peri-implantitis.

Aim: The aim of the study was to analyse MMP-8 levels in peri-Implant Sulcus Fluid (PISF) from peri-implantitis affected implants in smoking and non-smoking patients with different periodontal health status of natural teeth before and after peri-implantitis treatment.

Settings And Design: Altogether 29 patients with peri-implantitis were recruited and divided into two study groups (11 with healthy periodontium or gingivitis, i.

Application of multivariate statistical methodology to model factors influencing fate and transport of fecal pollution in surface waters.

The increasing number of polluted watersheds and water bodies with total maximum daily loads (TMDLs) has resulted in increased research to find methods that effectively and universally identify fecal pollution sources. A fundamental requirement to identify such methods is understanding the microbial and chemical processes that influence fate and transport of fecal indicators from various sources to receiving streams. Using the Watauga River watershed in northeast Tennessee as a model to better understand these processes, multivariate statistical analyses were conducted on data collected from four creeks that have or are expected to have pathogen TMDLs.

Particle size, surface charge and concentration dependent ecotoxicity of three organo-coated silver nanoparticles: comparison between general linear model-predicted and observed toxicity.

Mechanism underlying nanotoxicity has remained elusive. Hence, efforts to understand whether nanoparticle properties might explain its toxicity are ongoing. Considering three different types of organo-coated silver nanoparticles (AgNPs): citrate-coated AgNP, polyvinylpyrrolidone-coated AgNP, and branched polyethyleneimine-coated AgNP, with different surface charge scenarios and core particle sizes, herein we systematically evaluate the potential role of particle size and surface charge on the toxicity of the three types of AgNPs against two model organisms, Escherichia coli and Daphnia magna.

Immunoassay-based diagnostic point-of-care technology for oral specimen.

We have outlined our progress in developing a novel point-of-care platform to quantify micro-organisms causing dental infections and/or inflammatory markers reflecting an oral disease status. This system is based on a sandwich immunoassay technology known as ABICAP (Antibody Immuno Column for Analytical Processes) using poly-horseradish peroxidase conjugates. This assay enabled us to quantify 500 colony-forming units of Streptococcus sobrinus per milliliter of saliva.

Comparison of in vivo (Draize method) and in vitro (Corrositex assay) dermal corrosion values for selected industrial chemicals.

Skin irritation is a common occupational hazard for employees engaged in the manufacture, transport, and use of industrial chemicals. The most common method used to evaluate dermal irritation and/or corrosion has typically been in vivo tests using rabbits (Draize method). Several in vitro test methods have been developed, with Corrositex being the first to gain approval by a regulatory agency (U.

Toxicity of boron to the duckweed, Spirodella polyrrhiza.

Boron is an essential nutrient for plants and the potential exists for efficient removal of this element by wetland treatment systems due to accumulation by plants. To evaluate the efficacy of using Spirodella polyrrhiza to treat boron-contaminated wastewater or to be a suitable species for removing other nutrients from boron-containing wastewater the toxicity of this micronutrient was determined using standard methods. Frond production is apparently a more sensitive endpoint than either growth rate or the presence of abnormal fronds.