Effect of electrode characteristics on electromyographic activity of the masseter muscle.

OBJECTIVES: The study investigated effects of electrode material, inter-electrode distance (IED), and conductive gel on electromyographic (EMG) activity recorded from the masseter muscle. MATERIALS AND METHODS: EMG was recorded unilaterally, as ten volunteers performed standardized oral tasks. Ag/AgCl and Ag coated with Au were the gel-based; Ag alloy coated with graphene, pure Ag coated with graphene and silver nanowire embedded electrodes were the gel-free materials tested. Ag/AgCl electrodes were tested at three different IEDs (i.e. 15 mm, 20 mm, 25 mm). An electrode relative performance index (ERPI) was defined and calculated for each of the standardized oral tasks that the volunteers performed. ERPI values obtained for the different oral tasks with different electrode materials and IEDs were compared using two-way repeated-measures ANOVA. RESULTS: ERPI values were not significantly influenced by IED. However, for the electrode materials statistically significant differences were found in ERPI values for all oral tasks. Of the gel-free electrode materials tested, pure silver electrodes coated with graphene had the highest ERPI values followed by Ag alloy electrodes coated with graphene and silver nanowire embedded electrodes. CONCLUSIONS: Within the limitations of the study, IED between 15 and 25 mm has a negligible effect on masseter muscle EMG. Graphene coated and silver nanowire embedded electrodes show promise as gel-free alternatives.

Efficacy of Wound Cleansers on Wound-Specific Organisms Using In Vitro and Ex Vivo Biofilm Models.

Biofilms are believed to be a source of chronic inflammation in non-healing wounds. PURPOSE: In this study, the pre-clinical anti-biofilm efficacy of several wound cleansers was examined using the Calgary minimum biofilm eradication concentration (MBEC) and ex vivo porcine dermal explant (PDE) models on Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), and Candida albicans biofilms. METHODS: A surfactant-based cleanser and antimicrobial-based cleansers containing ionic silver, hypochlorous acid (HOCl), sodium hypochlorite (NaOCl), and polyhexamethylene biguanide (PHMB) were tested on the MBEC model biofilms with a 10-minute application time. Select cleansers were then tested on the mature PDE biofilms with 10-minute applications followed by the application of cleanser-soaked gauze. The PDE model was further expanded to include single and daily applications of the cleansers to mimic daily and 72-hour dressing changes. RESULTS: In the MBEC model, PHMB- and HOCl-based cleansers reduced immature MRSA, C albicans, and P aeruginosa biofilm regrowth by > 3× when compared with silver, surfactant, and saline cleansers. The major differences could be elucidated in the PDE model in which, after daily application, 1 PHMB-based cleanser showed a statistically significant reduction (3-8 CFU/mL log reduction) in all mature biofilms tested, while a NaOCl-based cleanser showed significant reduction in 2 microorganisms (3-5 CFU/mL log reduction, P aeruginosa and MRSA).The other PHMB-based cleanser showed a statistically significant 3 log CFU/mL reduction in P aeruginosa. The remaining cleansers showed no statistically significant difference from the saline control. CONCLUSION: Results confirm that there are model-dependent differences in the outcomes of these studies, suggesting the importance of model selection for product screening. The results indicate that 1 PHMB-based cleanser was effective in reducing mature P aeruginosa, MRSA, and C albicans biofilms and that sustained antimicrobial presence was necessary to reduce or eliminate these mature biofilms.

Effectiveness of silver alloy-coated silicone urinary catheters in patients with acute traumatic cervical spinal cord injury: Results of a quality improvement initiative.

Patients with acute traumatic cervical spinal cord injury (ATCSCI) have an increased risk of catheter-associated urinary tract infection (CAUTI). The effectiveness of silver alloy-coated silicone urinary catheters (SACC) in preventing CAUTI in ATCSCI is unknown and was the objective of this study. We performed a quality improvement initiative in an attempt to reduce CAUTI in patients undergoing spine surgery at a single quaternary center. Prior to July 2015, all patients received a latex indwelling catheter (LIC). All patients with ATCSCI with limited hand function (AIS A,B, or C) received a SACC. Incidence of CAUTI, microbiology, duration of infection, antibiotic susceptibility, and catheter-associated adverse events were recorded prospectively. We studied 3081 consecutive patients over the three years, of whom 302 (9.8%) had ATCSCI; 63% of ATCSCI patients were ASIA Impairment Scale (AIS) A or B. The overall rate of CAUTI was 19% (585/3081), and was 38% (116/302) in patients with ATCSCI. Of 178 ATCSCI patients with LIC, 100 (56%) developed a CAUTI compared with 28 of 124 (23%) patients with SACC (p < 0.05). Poly-microbial and gram-positive infection was more common in LIC than in SACC (p < 0.05). Median duration of infection was 9 days in SACC group and 12 days in LIC group (p = 0.08). Resistance to trimethoprim (p < 0.001) and ciprofloxacin (p < 0.05) were more common in LIC group. There was no difference in catheter-associated adverse events or length of stay between the groups. This quality improvement initiative illustrates the effectiveness of antiseptic silver alloy-coated silicone urinary catheters in patients with ATCSCI. In our population, the use of SACC reduces the incidence and the complexity of CAUTI.

Silver acupuncture for myofascitis: A protocol for systematic review and meta-analysis.

BACKGROUND: This systematic review aims to evaluate the effectiveness and safety of silver acupuncture in treatment of myofascitis. METHODS: Electronic databases of all silver acupuncture for myofascitis will be searched at PubMed, Cochrane Library, Springer, Embase, China National Knowledge Infrastructure, Wanfang, and Chinese Biological Medical disc from inception to March 31, 2020, with language restricted in Chinese and English. The primary outcome is visual analog scale, a short pain scale with sensitivity and comparability. Secondary outcomes included Clinical Assessment Scale for Cervical Spondylosis, Japanese Orthopaedic Association Scores, Oswestry dysfunction index, American Orthopaedic Foot and Ankle Society-Ankle Hindfoot scale, Foot and Ankle Ability Measure, The Cumberland ankle instability tool, Pittsburgh sleep quality index, self-rating anxiety scale, self-depression rating scale, and follow-up relapse rate. The systematic review and searches for randomized controlled trials of this therapy for myofascitis. The Cochrane RevMan V5.3 bias assessment tool is implemented to assess bias risk, data integration risk, meta-analysis risk, and subgroup analysis risk (if conditions are met). Mean difference, standard mean deviation, and binary data will be used to represent continuous results. RESULTS: This study will provide a comprehensive review and evaluation of the available evidence for the treatment of myofascitis with this therapy. CONCLUSION: This study will provide new evidence to evaluate the effectiveness and side effects of silver acupuncture for myofascitis. Due to the data are not personalized, no formal ethical approval is required. ETHICS AND DISSEMINATION: There is no requirement of ethical approval and it will be in print or disseminated by electronic copies. PROSPERO REGISTRATION NUMBER: CRD42020151476.

Potential of metabolic engineering in bacterial nanosilver synthesis.

The widespread applications of silver nanoparticles in present days demand an industrial-scale production process. The ability of bacteria to synthesise silver nanoparticles can be exploited to overcome many shortcomings associated with conventional production processes, such as high cost and nanoparticle toxicity. However, lack of a standardised protocol and suboptimal yield remain a major obstacle for bacterial synthesis route. A potential, yet unexplored, solution to this problem could be envisioned through rewiring of the metabolic network to direct cellular resources towards the product of interest. Mathematical modelling of metabolic pathway is the key to understand and manipulate the cellular metabolism for enhanced production of desired metabolite(s). The present study provides a perspective on the scope of metabolic engineering approaches to enhance bacterial synthesis of silver nanoparticles.

Pilot estuarine mesocosm study on the environmental fate of Silver nanomaterials leached from consumer products.

Although nanosilver consumer products (CPs) enjoy widespread availability, the environmental fate, leaching, and bioaccumulation behaviors of silver nanoparticles (AgNPs) from these products are not well understood. In this work, three nanosilver CPs, two AgNP standards, and an ionic silver (Ag(+)) standard were studied in estuarine mesocosms. The CPs exhibited long-term release of significant amounts of silver over a 60d residence time in the mesocosms, and ultimately released 82 - 99% of their total silver loads. Measurements of total silver as a function of time, by inductively coupled plasma mass spectrometry (ICP-MS), indicated that the silver was transferred from the water column and accumulated in the estuarine biota, including hard clams, grass shrimp, mud snails, cordgrass stalks and leaves, biofilms, intertidal sediment, and sand. The ICP-MS results and calculations of bioconcentration and trophic transfer factors indicated that significant amounts of silver were taken up by the organisms through trophic transfer. Silver was also adsorbed from the seawater into the biofilms, sediment, and sand, and from the sand into the clams.

120 years of nanosilver history: implications for policy makers.

Nanosilver is one nanomaterial that is currently under a lot of scrutiny. Much of the discussion is based on the assumption that nanosilver is something new that has not been seen until recently and that the advances in nanotechnology opened completely new application areas for silver. However, we show in this analysis that nanosilver in the form of colloidal silver has been used for more than 100 years and has been registered as a biocidal material in the United States since 1954. Fifty-three percent of the EPA-registered biocidal silver products likely contain nanosilver. Most of these nanosilver applications are silver-impregnated water filters, algicides, and antimicrobial additives that do not claim to contain nanoparticles. Many human health standards for silver are based on an analysis of argyria occurrence (discoloration of the skin, a cosmetic condition) from the 1930s and include studies that considered nanosilver materials. The environmental standards on the other hand are based on ionic silver and may need to be re-evaluated based on recent findings that most silver in the environment, regardless of the original silver form, is present in the form of small clusters or nanoparticles. The implications of this analysis for policy of nanosilver is that it would be a mistake for regulators to ignore the accumulated knowledge of our scientific and regulatory heritage in a bid to declare nanosilver materials as new chemicals, with unknown properties and automatically harmful simply on the basis of a change in nomenclature to the term "nano".

An evaluation of the quality of root fillings in mandibular incisors and maxillary and mandibular canines using different methodologies.

OBJECTIVES: To evaluate the quality of root fillings in mandibular incisors and maxillary and mandibular canines using different methodologies of evaluation, namely radiographs, the fluid transport test and the percentage of gutta-percha (PGP), and to determine if a correlation occurs between the results of the different methodologies used. METHODS: One group of mandibular incisors with oval canals (n=20) and one group of maxillary and mandibular canines (n=20) were instrumented and obturated by cold lateral compaction using AH 26 as the sealer. The filled roots were bucco-lingually and mesio-distally radiographed. Using a scoring system, the quality of each root filling was radiographically evaluated, the higher the score the poorer the quality. Fluid transport along the root filling was then measured using a fluid transportation device. Each root was horizontally sectioned 4 and 6mm from the apex. Images of the cross-sections were taken, using a microscope and a digital camera. Images were scanned into a PC as TIFF images. Using a KS 100 Imaging system the canal area and the gutta-percha filled areas were measured. The percentage of gutta-percha filled areas was calculated. RESULTS: Considering the radiographic scores of the two different projections together the score was significantly higher for the mandibular incisors than for the canines (P=0.039). The radiographic score was significantly higher for the mesio-distal radiograph in comparison with the bucco-lingual radiograph (P=0.0001), for the canines as well as the incisors. Using only the bucco-lingual radiograph there was no significant difference between the mandibular incisors and the canines (P=0.992). The mandibular incisors displayed significantly more fluid transport than the canines (P=0.049). A significantly greater percentage of gutta-percha filled areas was found in the cross-sections of canines as compared to the cross-sections of mandibular incisors (P=0.000001). The correlation between the radiographic score of the mesio-distal radiograph and the PGP 4 and 6mm was significant (P=0.013). There was no significant correlation between the FT and the radiograph or the FT and the PGP. CONCLUSIONS: The quality of the root fillings in oval canal-mandibular incisors may be compromised.

Rapid reduction of Staphylococcus aureus populations on stainless steel surfaces by zeolite ceramic coatings containing silver and zinc ions.

This study demonstrates the anti-Staphylococcus aureus properties of stainless steel surfaces coated with zeolite containing 2.5% silver and 14% zinc ions. Stainless steel panels with and without the heavy-metal-containing coatings were inoculated with S. aureus and incubated at room temperature. Survival of S. aureus was significantly reduced by the silver/zinc coatings within 1 h. Many hospital surfaces could be constructed of stainless steel with silver/zinc zeolite coatings. Such measures may reduce rates of hospital-acquired S. aureus infection.

An economic model to assess the cost and benefits of the routine use of silver alloy coated urinary catheters to reduce the risk of urinary tract infections in catheterized patients.

Prevalence studies generally find nosocomial urinary tract infections to be the most common type of nosocomial infection, accounting for between 21% and 45% of all HAIs. The main risk factor appears to be the presence of a urinary catheter, with an estimated 80% of these infections being associated with their use. This paper describes a model which quantifies the extent of the burden of these infections in terms of the number of patients affected and the costs incurred by the hospital sector; and identifies the potential benefits of the routine use of silver alloy coated catheters, as a means of reducing the incidence of this type of infection. An illustrative model of the annual costs and benefits associated with the routine use of this intervention in adult, non-day case patients admitted to the medical and surgical specialties of NHS hospitals throughout England is presented. The results suggest that a 14.6% reduction in the incidence of urinary tract infections in catheterized medical patients, and a 11.4% reduction in catheterized surgical patients, would cover the cost of the intervention. Any further reduction in incidence would result in net positive benefits.

Estudo do comportamento da prata metálica, através das densidades óptica e de volume, com filmes radiográficos processados nas soluçöes convencional e monobanho / Behaviour study of metalic silver, across optical density and of volume, with radiographic films processed in conventional and monobath solutions

O presente trabalho teve a finalidade de analisar, através de um novo método de medida, a quantidade de prata metálica na emulsäo de filmes radiográficos. O método proposto baseia-se na determinaçäo da densidade de volume de prata reduzida em funçäo das variáveis: exposiçäo aos raios X, tipo de filmes e de soluçöes de processamento. Utilizamos para controle e comparaçäo as densidades ópticas obtidas em um fotodensitômetro, bem como a confecçäo de seus respectivos traçados característicos, para cada tipo de filme radiográfico (Kodak e Agfa) e processamento (Kodak e Inodon). A determinaçäo da densidade de volume ocupado pela prata metálica baseia-se nos princípios de morfometria. Utilizamos portanto, para sua obtençäo, de uma ocular com retículo de 25 pontos em um microscópio de luz, com objetiva de 97X. A densidade de prata da emulsäo foi estimada pelo método de Chalkley, da seguinte maneira: no microscópio, após a focalizaçäo do filme radiográfico, contaram-se os pontos coincidentes com os gräos de prata. Todas as faixas de exposiçäo em cada um dos filmes radiográficos processados, nos dois diferentes tipos de soluçöes, foram analisados, quarenta diferentes acampos, com um total de 1000 pontos. A comparaçäo do método proposto com o já consagrado da densitometria óptica e respectivos traçados característicos, foi realizada através das análises estatística e gráfica. Primeiro foi demonstrado, por um programa de ajuste de polinômios, que as variáveis apresentavam uma linearidade de primeiro grau; em seguida foram calculados os coeficientes de correlaçäo e as retas de regressäo da densidade de volume em relaçäo à densidade óptica. Os coeficientes de correlaçäo apresentavam níveis bastantes elevados, fato este confirmado graficamente pela similariedade dos traçados característicos obtidos pelos dois métodos de medida. Pelos resultados alcançados, chegamos à conclusäo que o método proposto, também é válido para a verificaçäo do efeito dos raios X sobre a emulsäo de filmes radiográficos periapicais, podendo ser utilizado portanto, nas pesquisas que visam analisar o comportamento dos filmes e processamento radiográfico

Determination of silver in biological samples using graphite furnace atomic absorption spectrometry based on Zeeman effect background correction and matrix modification.

A method for the determination of silver in human body fluids and biological material is described. The silver in an acid digest of biological samples and diluted body fluids is quantified using Zeeman graphite furnace atomic absorption spectrometry (ZGFAAS). The effects of NH4H2PO4 as matrix modifier and standard addition are discussed. Atomization from the graphite tube wall and from the pyrolytical tube with platform is also discussed and the peak height and the peak area are compared. The best results were achieved by using matrix modification, stabilized temperature platform furnace, integrated absorbance and standard addition technique. The calibration was linear up to 15 micrograms X L-1; the between-run precision was 5.9% at 40 micrograms X kg-1 of silver.