Electrochemical modification of high contact stainless steel 304 surfaces for antimicrobial applications

Crude oils are the essential resources for the usages of industrial purposes in various forms and the refining is a key process of separating the mixture of raw crude oils. In the existing research there were expected to investigate the impact of salts, organic acids, mercaptans and elemental sulfur of crude oils on the corrosion rates of seven different types of ferrous metals in both qualitatively and quantitatively. The chemical compositions of such selected ferrous metals and the above mentioned corrosive properties of two different types of crude oils were measured by the standard instruments and methodologies. A set of similar sized metal coupons were prepared from seven different types of metals and the corrosion rates of such metals were determined by the relative weight loss method. In addition, that the corroded metal surfaces were analyzed under the microscope, decayed metal concentrations and deductions of the initial hardness of metal coupons were measured. According to the obtained results that there were observed the lower corrosion rates from stainless steels with at least 12% of chromium and nickel, higher corrosive impact from salt, formations of FeS, Fe2O3, corrosion cracks and pitting corrosion.

The effect of primers on shear bond strength of acrylic resins to different types of metals

Chapter 2.1.1 - Pyrometallurgical Principles

Children in low- and middle-income countries are particularly vulnerable in the months following an initial health event (IHE), with increased risk of mortality caused mostly by infectious diseases. Due to exposure to a wide range of environmental stressors, hospitalization in itself might increase child vulnerability at discharge. The goal of this study was to disentangle the role of hospitalization on the risk of subsequent infection. Data from a prospective, longitudinal, international, multicenter mother-and-child cohort were analysed. The main outcome assessed was the risk of subsequent infection within 3 months of initial care at hospital or primary healthcare facilities. First, risk factors for being hospitalized for the IHE (Step 1) and for having a subsequent infection (Step 2) were identified. Then, inpatients were matched with outpatients using propensity scores, considering the risk factors identified in Step1. Finally, adjusted on the risk factors identified in Step2, Cox regression models were performed on the matched data set to estimate the effect of hospitalization at the IHE on the risk of subsequent infection. Among the 1312 children presenting an IHE, 210 (16%) had a subsequent infection, mainly lower-respiratory infections. Although hospitalization did not increase the risk of subsequent diarrhoea or unspecified sepsis, inpatients were 1.7 (95% Confidence Intervals [1.0-2.8]) times more likely to develop a subsequent lower-respiratory infection than comparable outpatients. For the first time, our findings suggest that hospitalization might increase the risk of subsequent lower-respiratory infection adjusted on severity and symptoms at IHE. This highlights the need for robust longitudinal follow-up of at-risk children and the importance of investigating underlying mechanisms driving vulnerability to infection.

BackgroundRisks for subsequent multidrug-resistant gram-negative bacteria (MDRGNB) infection and long-term outcome after hospitalization among patients with MDRGNB colonization remain unknown.MethodsThis observational study enrolled 817 patients who were hospitalized in the study hospital in 2009. We defined MDRGNB as a GNB resistant to at least three different antimicrobial classes. Patients were classified into MDRGNB culture-positive (MDRGNB-CP; 125 patients) and culture-negative (MDRGNB-CN; 692 patients) groups based on the presence or absence of any MDRGNB identified from either active surveillance or clinical cultures during index hospitalization. Subsequent MDRGNB infection and mortality within 12 months after index hospitalization were recorded. We determined the frequency and risk factors for subsequent MDRGNB infection and mortality associated with previous MDRGNB culture status.ResultsIn total, 129 patients had at least one subsequent MDRGNB infection (MDRGNB-CP, 48.0%; MDRGNB-CN, 10.0%), and 148 patients died (MDRGNB-CP, 31.2%; MDRGNB-CN, 15.9%) during the follow-up period. MDR Escherichia coli and Acinetobacter baumannii were the predominant colonization microorganisms; patients with Proteus mirabilis and Pseudomonas aeruginosa had the highest hazard risk for developing subsequent infection. After controlling for other confounders, MDRGNB-CP during hospitalization independently predicted subsequent MDRGNB infection (hazard ratio [HR], 5.35; 95% confidence interval [CI], 3.72–7.71), all-cause mortality (HR, 2.42; 95% CI, 1.67–3.50), and subsequent MDRGNB infection-associated mortality (HR, 4.88; 95% CI, 2.79–8.52) after hospitalization.ConclusionsHarboring MDRGNB significantly increases patients’ risk for subsequent MDRGNB infection and mortality after hospitalization, justifying the urgent need for developing effective strategies to prevent and eradicate MDRGNB colonization.

This paper presents a numerical study of inelastic localisations in metals after utilising a thermodynamically consistent framework of viscoplastic formulation implemented into a commercial finite element code. The significance of using physically-based flow stress relations, instead of empirical relations, is examined by considering three microstructure-based constitutive equations developed previously for three different crystal types of metals. The same numerical values of material constants are used with a range of loading initial temperatures and velocity impacts. Differences of dynamic localisations between three body-centred cubic metals (niobium, tantalum and vanadium), one fcc metal (OFHC copper) and one hcp metal (titanium) are illustrated and discussed through studying the initiation and propagation of necking and shear bands in a circular bar and simple tension plane strain problems, respectively. Moreover, the effect of initial temperatures and strain rates on dynamic localisations is also scrutinised. Objective results using different mesh configurations are verified as a result of including viscosity in the constitutive models.

Crude oil is an energy resource that mostly composed with hydrocarbons and trace corrosive compounds as well found some cruxes in the petroleum refining industry because of the vast applications of the different types of metals. There were expected to investigate the effect of two different types of crude oils on the corrosion of seven types of selected ferrous metals in the pertinent research. The concerned corrosive properties of both crude oils were tested by standard methods and instruments also the chemical compositions of selected ferrous metals were tested. The corrosion rates of a series of similar size prepared metal coupons were tested after limited immersion time periods as three trials in crude oils by the weight loss method since aiding the microscopic analysis to identify the corrosion compounds. Apart from those speculations the decayed metallic elemental mounts from the metals into crude oils and the reductions of the initial hardness of metal coupons were tested. The obligatory results showed the relatively higher corrosion rates from carbon steels, relatively lower corrosion rates from stainless steels in both crude oils, formation of FeS in most of observations, decay of ferrous and copper into crude oils from some metals and slight reductions of the initial hardness of metal coupons due to the formation of the corrosion on the metal surfaces.

BackgroundIn ICU patients, digestive tract colonization by multidrug-resistant (MDR) Gram-negative (G−) bacteria is a significant risk factor for the development of infections. In patients undergoing extracorporeal membrane oxygenation (ECMO), colonization by MDR bacteria and risk of subsequent nosocomial infections (NIs) have not been studied yet. The aim of this study is to evaluate the incidence, etiology, risk factors, impact on outcome of gastrointestinal colonization by MDR G− bacteria, and risk of subsequent infections in patients undergoing ECMO.MethodsThis is a retrospective analysis of prospectively collected data: 105 consecutive patients, treated with ECMO, were admitted to the ICU of an Italian tertiary referral center (San Gerardo Hospital, Monza, Italy) from January 2010 to November 2015. Rectal swabs for MDR G− bacteria were cultured at admission and twice a week. Only colonization and NIs by MDR G− bacteria were analyzed.ResultsNinety-one included patients [48.5 (37–56) years old, 63% male, simplified acute physiology score II 37 (32–47)] underwent peripheral ECMO (87% veno-venous) for medical indications (79% ARDS). Nineteen (21%) patients were colonized by MDR G− bacteria. Male gender (OR 4.03, p = 0.029) and duration of mechanical ventilation (MV) before ECMO > 3 days (OR 3.57, p = 0.014) were associated with increased risk of colonization. Colonized patients had increased odds of infections by the colonizing germs (84% vs. 29%, p < 0.001, OR 12.9), longer ICU length of stay (LOS) (43 vs. 24 days, p = 0.002), MV (50 vs. 22 days, p < 0.001) and ECMO (28 vs. 12 days, p < 0.001), but did not have higher risk of death (survival rate 58% vs. 67%, p = 0.480, OR 0.68). Infected patients had almost halved ICU survival (46% vs. 78%, p < 0.001, OR 4.11).ConclusionsIn patients undergoing ECMO for respiratory and/or circulatory failure, colonization by MDR G− bacteria is frequent and associated with more the tenfold odds for subsequent infection. Those infections are associated with an increased risk of death.

Clinical Significance of Commensal Bacteria Isolated from Bronchoalveolar Lavage of Lung Transplant Recipients

Many studies have performed dosimetric studies using various metal implants however these are difficult to translate to other implants of a different geometry or material (Rijken and Colyer, J Appl Clin Med Phys 18:5:301-306, 2017; Ade and du Plessis, J Appl Clin Med Phys 18:5:162-173, 2017; Prabhakar et al. Rep Pract Oncol Radiother 18:209-213, 2013; Ng et al. Rep Pract Oncol Radiother 20:273-277, 2015; Reft et al. Med Phys 30:1162-1182, 2003; Sasaki et al., Nihon Hoshasen Gijutsu Gakkai Zasshi 72(9):735-745, 2016). In this study, the ability of the Monaco Monte Carlo algorithm (Elekta AB, Stockholm, Sweden) to model radiation transport through different types of metals was evaluated. Investigation of the capabilities and limitations of the algorithm is required for the potential use of Monaco for planning radiotherapy treatments when avoidance of metal implants is clinically undesirable. A MapCHECK 2 diode array (Sun Nuclear Corp, Melbourne, USA) and a PTW 30013 Farmer chamber was used to measure the dose at depth, downstream of 1cm × 5cm × 5cm metal blocks of three known compositions; stainless steel, aluminium and MCP96. The setup was imaged using a CT scanner and imported into the Monaco TPS where the beam arrangement was replicated. The density of the metals was overridden using the known electron density of each (IMPAC Medical Systems Inc, Monaco dose calculation technical reference. IMPAC Medical Systems, Sunnydale, CA, 2013). The differences between the dose measured using the ion chamber and calculated using Monaco downstream of the 1cm metal blocks were respectively: - 1.2%, - 2.2% and 9.5% when irradiated using a 6 MV beam, and - 0.9%, - 1.3% and 14%, when irradiated using a 15 MV beam. This was then repeated using 2cm and 3cm of each metal type giving similar results for aluminium and stainless steel and increased discrepancy for MCP96. Discrepancies between treatment planning software and measurements at depth have been shown to give uncertainties between 5 and 23% in previous studies (Rijken and Colyer, J Appl Clin Med Phys 18:5:301-306, 2017; Ade and du Plessis, J Appl Clin Med Phys 18:5:162-173, 2017; Prabhakar et al. Rep Pract Oncol Radiother 18:209-213, 2013; Ng et al. Rep Pract Oncol Radiother 20:273-277, 2015; Reft et al. Med Phys 30:1162-1182, 2003; Sasaki et al., Nihon Hoshasen Gijutsu Gakkai Zasshi 72(9):735-745, 2016). This study uses basic shapes providing results that remove the uncertainties in geometry and can therefore be applied to any shape. This will help determine whether errors in dose calculations are due to the TPS particle transport algorithms or due to other effects, such as inaccurate contouring or incorrect densities. Thus giving the planner an additional degree of freedom in their planning and decision making process.

In this study, different types of graphene, including single-, few-, and multi-layer graphene, were grown on a stainless steel (SS) mesh coated with Cu catalyst by using the chemical vapor deposition (CVD) method. Even though the SS mesh consisted of different types of metals, such as Fe, Ni, and Cr, which can also be used as catalysts, the reason for coating Cu catalyst on the SS surface had been related to the nature of the Cu, which promotes the growth of graphene with high quality and quantity at low temperature and time. The reaction temperature and run time, as the most important parameters of the CVD method, were varied, and thus led to the synthesis of different layers of graphene. Moreover, the presence of single-, few-, and multi-layer graphene was confirmed by employing two techniques, namely transmission electron microscopy (TEM) and Raman spectroscopy. On top of that, electron dispersive X-ray (EDX) was further applied to establish the influence of the CVD parameters on the growth of graphene.

Metal adhesion issues in dry grinding: The role of active fillers

Our understanding of humoral response to human papillomavirus (HPV) infection has been mainly derived from studies in women. The role of serum antibodies in the natural history of HPV in men has yet to be investigated. Data from 285 male participants of a natural history study were used to determine the epidemiologic factors associated with HPV 16/18 seropositivity and explore the role of HPV 16 and 18 serum antibodies in subsequent HPV infections. Serum antibodies were detected by use of HPV 16- and 18 virus-like particles enzyme-linked immunoassay. Logistic regression and Generalized Estimating Equation was used for the evaluation of risk factors. The risk of subsequent HPV infection by baseline antibody status was assessed by incidence rate ratio and its confidence intervals. Men ages 36 to 44 years compared with men ages 18 to 25 years were four times more likely to be seropositive to HPV 16/18. In addition, being divorced, separated, or widowed; being a former smoker; and having sex with men was positively and independently associated with HPV 16/18 seropositivity. Our findings on the potential role of HPV 16 or 18 serum antibodies in subsequent infection were inconclusive. Large prospective studies are warranted to adequately address questions on the role of natural immunity in the natural history of HPV infections in men.

This paper describes a program of making ‘global’ fits to the large amount of experimental equation of state (EOS) data on monatomic metals that has become available in recent years. The fits are made within the framework of a phenomenological scaling theory for metallic liquids which incorporates recently discovered general theoretical properties of the EOS of liquids. The theory is expected to be applicable to monatomic metals up to high temperatures (~ 10 to 100 x the melting temperature Tm) and at all densities, so long as the metallic bonding does not change character — as, for instance, might be caused by electronic phase transitions or sufficiently large thermal electron excitations. The goal of the present fitting studies is to obtain consistent tabular representations of the EOS of metals over a wide range of densities (0.5 ≤ ρ/ρo ≤ 2) and temperatures (up to several eV) which are reliable enough both to be used in applied work (errors < ~5%) and to serve as a guide to future theoretical and experimental studies of metals. Fits to experimental data for examples of three different types of metals — Na, Pb, and Ta — will be discussed.

The ubiquity of electronic devices has made them indispensable in daily life. Nevertheless, this high priority leads to a surge in electronic waste, or e-waste, which is extremely dangerous for the environment and human health. E-waste contributes to environmental pollution and threatens ecosystems and human health. Management of recycling methods and efficient e-waste is crucial to lower these dangers. Traditional recycling techniques are effective, but often release harmful pollutants. The present study has attempted to use the metal-resistant Exiguobacterium himgiriensis isolated from e-waste, such as the Printed Circuit Board (PCB), to investigate its efficiency in removing heavy metals from these substrates. By using ICP-OES, it has been found that this species of bacterium recovered different types of metals (Co 84.67%, Ni 83.25%, Pb 80.17%, Cu 80.06%, Zn 76.71%, Al 76.13%, Fe 71.74%, and Ag 64.97% respectively) within 5 days under laboratory conditions. Detecting structural and functional group changes in the control PCB and bioleached residue by the FT-IR, FE-SEM, EDS, and XRD techniques confirms the evidence of bioleaching. Bacteria can increase their dissolving capacity and decrease surface tension by chemically changing metals. E. himgiriensis bioleaches PCB samples for 5 days, resulting in rougher, uneven surfaces with fractures and fissures. FT-IR spectroscopy reveals the bacterium's impact on metals, particularly Si, O, and Fe. This study could help reduce environmental pollution and health risks associated with e-waste by developing an economical and environmentally friendly method for bioleaching different metals in PCB.