Novel Magnetic Nanoparticle Adsorbents for Organic and Inorganic Contaminants

Water is not only a resource, but a life source. However, water pollution is one of the most challenging global issues that seriously threatened to people's life and sustainable development. With the continual concern over the presence of naturally-occurring and anthropogenic organic and inorganic contaminants in the aquatic environment, there is a growing need for the implementation of innovative treatment methods for the elimination of these contaminants from natural waters and wastewater effluents. Featuring high adsorption capacity, good regenerability, and surface area accessibility, magnetic nanoparticles (MNPs) have emerged as a new generation of sorbent materials for environmental decontamination in the past few years. Due to their superparamagnetic property that can be attracted to a magnetic field, it is easy to separate these MNPs adhered with contaminants from aqueous solution or complicated matrices by simply applying an external magnetic field; no filtration, centrifugation or gravitational separation is needed, making them a much more sustainable option than more traditional approaches for removing organic and inorganic contaminants. In this doctoral research, 4 different novel magnetic-core composite nanoparticle sorbents were developed for organic and metal contaminants remediation in aquatic systems. These sorbents have a core-shell structure with a magnetite core and a silica porous layer that permanently confines surfactant micelles (namely as Mag-PCMAs, targeting organic contaminants removal) or are functionalized with metal-binding organic ligands (namely as Mag-Ligands, targeting metal contaminants removal). The physicochemical properties of these magnetic nanoparticle sorbent was fully characterized via transmission electron microscopy, scanning electron microscopy, thermogravimetric analyses, fourier transform infrared spectroscopy, superconducting quantum interference device magnetometer, X-ray diffraction and BET porosimeter. The removal efficiencies of organic contaminants such as PAHs, emerging organic contaminants (EOCs, including pharmaceuticals, industrial additives) onto Mag-PCMAs and metal contaminants such as cadmium, lead, mercury, chromium and etc. onto Mag-Ligand were evaluated across a wide range of environmental conditions (e.g. pH, water hardness). The adsorption isotherms and kinetics of various contaminants onto the magnetic nanoparticle sorbents were determined respectively. Competitive sorption studies were conducted to determine the selectivity sequence among multiple metal ions onto Mag-Ligands. Isothermal titration microcalorimetry (ITC) was used to obtain key quantitative thermodynamic binding data of the interactions between Mag-Ligand and metal ions, providing the enthalpy, entropy and free energy of binding values as well as binding constants. Micelle swelling agent was used to optimize Mag-PCMAs’ porous structure for increasing pore volume and surface area to achieve higher removal efficiency and sorption kinetics. In addition, study was investigated on simultaneous removal of metal contaminants and PAHs across a variety of environmental conditions. The regenerability and reusability of these magnetic nanoparticle sorbents were also studied; both Mag-PCMAs and Mag-Ligand can be regenerated via rinsing with methanol or dilute acid, and can be reused for several treatment cycles without significant decrease on efficiency. This study has provided a rapid, effective and more sustainable approach for organic and metal contaminants remediation from aquatic systems

Positive association between different triglyceride glucose index-related indicators and psoriasis: evidence from NHANES

BackgroundPsoriasis is a chronic inflammatory skin disease with effects that extend beyond the skin. Insulin resistance (IR) has been associated with psoriasis, but it remains unclear how indicators related to the triglyceride glucose (TyG) index, which were associate with IR, are associated with the condition.ObjectiveThe purpose of this study was to investigate the association between psoriasis and three TyG-related indicators: triglyceride glucose-body mass index (TyG-BMI), triglyceride glucose-waist to height ratio (TyG-WHtR), and triglyceride glucose-waist circumference (TyG-WC).MethodsData from adults aged 20 to 80 years in the National Health and Nutrition Examination Survey (NHANES) from 2003 to 2006 and 2009 to 2014 were utilized. Institutional Review Board approval and documented written consent was obtained from participants by NHANES (Protocol #2005–06). The patients were divided into three groups based on TyG-BMI, TyG-WC, and TyG-WHtR: Q1 (1st quintile), Q2 (2nd-3rd quintiles), and Q3 (4th-5th quintiles). Differences between the groups were further explored. Multivariate logistic regressions were used to investigate the correlation between these three indicators and psoriasis, with results expressed as odds ratios (OR) and 95% confidence intervals (CI). Subgroup analysis and supplementary analysis was further conducted to explore potential influencing factors.ResultsThe study included 9,291 participants, of which 260 had psoriasis. Compared Q2 and Q3 of TyG-BMI, TyG-WC, and TyG-WHtR to Q1, there were significantly associate with psoriasis. Among the three indicators, TyG-WC consistently had the highest OR values in Models 1 and 2 (Model 1: Q3 OR (95% CI) = 2.155 (1.442-3.220); Model 2: Q3 OR (95% CI) = 2.029 (1.341-3.069)). While in Model 3, the TyG-BMI shows more significant relationship with psoriasis (Model 3 of TyG-BMI: Q3 OR (95% CI) = 1.948 (1.300-3.000)). Similar results were observed in the majority of subgroups and in supplementary analysis.ConclusionThis study identified a stable and strong positive association between TyG-related indicators (TyG-BMI, TyG-WC, and TyG-WHtR) and psoriasis. This association persisted even after adjusting for multiple factors. It is suggested that high IR is significantly associated with psoriasis

Structural analysis and insertion study reveal the ideal sites for surface displaying foreign peptides on a betanodavirus-like particle

Additional file 3: The averaged density distribution of the 3D reconstructions. The mass densities of the RBS are spherically averaged and plotted as a function of the particle radius. Below a radius of 115 Å is the density of enclosed RNA fragments (The RNA fragments do not belong to the virus genome, they are arbitrarily enclosed bacterial RNA). The density distribution between 115–150 Å and 150–190 Å are the capsid and the protrusion respectively. In the capsid shell, each subunit arranged in a “jerry-roll” structure results in that the capsid shell looks like two layers (two density peaks)

Simultaneous removal of cadmium and nitrate in aqueous media by nanoscale zerovalent iron (nZVI) and Au doped nZVI particles

Nanoscale zerovalent iron (nZVI) has demonstrated high efficacy for treating nitrate or cadmium (Cd) contamination, but its efficiency for simultaneous removal of nitrate and Cd has not been investigated. This study evaluated the reactivity of nZVI to the co-contaminants and by-product formation, employed different catalysts to reduce nitrite yield from nitrate, and examined the transformation of nZVI after reaction. Nitrate reduction resulted in high solution pH, negatively charged surface of nZVI, formation of Fe3O4 (a stable transformation of nZVI), and no release of ionic iron. Increased pH and negative charge contributed to significant increase in Cd(II) removal capacity (from 40 mg/g to 188 mg/g) with nitrate present. In addition, nitrate reduction by nZVI could be catalyzed by Cd(II): while 30% of nitrate was reduced by nZVI within 2 h in the absence of Cd(II), complete nitrate reduction was observed in the presence of 40 mg-Cd/L due to the formation of Cd islands (Cd(0) and CdO) on the nZVI particles. While nitrate was reduced mostly to ammonium when Cd(II) was not present or at Cd(II) concentrations ≥ 40 mg/L, up to 20% of the initial nitrate was reduced to nitrite at Cd(II) concentrations < 40 mg/L. Among nZVI particles doped with 1 wt. % Cu, Ag, or Au, nZVI deposited with 1 wt. % Au reduced nitrite yield to less than 3% of the initial nitrate, while maintaining a high Cd(II) removal capacity

Versailles project on advanced materials and standards (VAMAS) interlaboratory study on measuring the number concentration of colloidal gold nanoparticles

We describe the outcome of a large international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS). A total of 50 laboratories delivered results for the number concentration of 30 nm gold colloidal nanoparticles measured using particle tracking analysis (PTA), single particle inductively coupled plasma mass spectrometry (spICP-MS), ultraviolet-visible (UV-Vis) light spectroscopy, centrifugal liquid sedimentation (CLS) and small angle X-ray scattering (SAXS). The study provides quantitative data to evaluate the repeatability of these methods and their reproducibility in the measurement of number concentration of model nanoparticle systems following a common measurement protocol. We find that the population-averaging methods of SAXS, CLS and UV-Vis have high measurement repeatability and reproducibility, with between-labs variability of 2.6%, 11% and 1.4% respectively. However, results may be significantly biased for reasons including inaccurate material properties whose values are used to compute the number concentration. Particle-counting method results are less reproducibile than population-averaging methods, with measured between-labs variability of 68% and 46% for PTA and spICP-MS respectively. This study provides the stakeholder community with important comparative data to underpin measurement reproducibility and method validation for number concentration of nanoparticles

Versailles project on advanced materials and standards (VAMAS) interlaboratory study on measuring the number concentration of colloidal gold nanoparticles

We describe the outcome of a large international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS). A total of 50 laboratories delivered results for the number concentration of 30 nm gold colloidal nanoparticles measured using particle tracking analysis (PTA), single particle inductively coupled plasma mass spectrometry (spICP-MS), ultraviolet-visible (UV-Vis) light spectroscopy, centrifugal liquid sedimentation (CLS) and small angle X-ray scattering (SAXS). The study provides quantitative data to evaluate the repeatability of these methods and their reproducibility in the measurement of number concentration of model nanoparticle systems following a common measurement protocol. We find that the population-averaging methods of SAXS, CLS and UV-Vis have high measurement repeatability and reproducibility, with between-labs variability of 2.6%, 11% and 1.4% respectively. However, results may be significantly biased for reasons including inaccurate material properties whose values are used to compute the number concentration. Particle-counting method results are less reproducibile than population-averaging methods, with measured between-labs variability of 68% and 46% for PTA and spICP-MS respectively. This study provides the stakeholder community with important comparative data to underpin measurement reproducibility and method validation for number concentration of nanoparticles

Versailles project on advanced materials and standards (VAMAS) interlaboratory study on measuring the number concentration of colloidal gold nanoparticles

We describe the outcome of a large international interlaboratory study of the measurement of particle number concentration of colloidal nanoparticles, project 10 of the technical working area 34, "Nanoparticle Populations" of the Versailles Project on Advanced Materials and Standards (VAMAS). A total of 50 laboratories delivered results for the number concentration of 30 nm gold colloidal nanoparticles measured using particle tracking analysis (PTA), single particle inductively coupled plasma mass spectrometry (spICP-MS), ultraviolet-visible (UV-Vis) light spectroscopy, centrifugal liquid sedimentation (CLS) and small angle X-ray scattering (SAXS). The study provides quantitative data to evaluate the repeatability of these methods and their reproducibility in the measurement of number concentration of model nanoparticle systems following a common measurement protocol. We find that the population-averaging methods of SAXS, CLS and UV-Vis have high measurement repeatability and reproducibility, with between-labs variability of 2.6%, 11% and 1.4% respectively. However, results may be significantly biased for reasons including inaccurate material properties whose values are used to compute the number concentration. Particle-counting method results are less reproducibile than population-averaging methods, with measured between-labs variability of 68% and 46% for PTA and spICP-MS respectively. This study provides the stakeholder community with important comparative data to underpin measurement reproducibility and method validation for number concentration of nanoparticles