Evaluation of blood lead levels in opium addicts and healthy control group using novel deep eutectic solvent based dispersive liquid-liquid microextraction followed by GFAAS.

Today, drug dealers and sellers add lead compounds to these substances to get more profit. As a result, drug users are heavily exposed to lead, and lead poisoning is clearly seen in most of them. Therefore, it is especially important to check the blood lead levels in these people. In this research, an efficient and eco-friendly pretreatment method was established by deep eutectic solvent for dispersive liquid-liquid microextraction (DES - DLLME) followed by graphite furnace atomic absorption spectrometry (GFAAS) analysis. The selected hydrophilic deep eutectic solvent consists of l-menthol and (1S)-( +)-camphor-10-sulfonic acid (CSA) at a 5:1 molar ratio as a green solvent instead of traditional toxic organic solvents. Under the optimal extraction conditions, the introduced method exhibited good linearity with coefficient of determination (r2) 0.9975 and an acceptable linear range of 0.3-80 µg L-1. Accordingly, the detection limit was 0.1 µg L-1 (S/N = 3) for lead ions, and the high enrichment factor (240) was obtained. The proposed method was successfully applied to analysis lead ions in real blood samples, which is a promising technique for biological samples. The case samples were classified and analyzed based on age, duration of consumption, and type of substance. The results showed that there was no significant difference between blood lead levels in different age groups and different duration of use, while blood lead levels were higher in opium residue (shireh) users than in opium users.

Interactions of airborne graphene oxides with the sexual reproduction of a model plant: When production impurities matter.

The increasing use of graphene-related materials (GRMs) in everyday-life products raises concerns for their possible release into the environment and consequent impact on organisms. GRMs have widely varying effects on plants and, according to recent evidences, graphene oxide (GO) has the potential to interfere with the sexual reproduction owing to its acidic properties and production residues. Here, stigmas of the model plant Cucurbita pepo (summer squash) were subjected to simulated dry depositions of GO and GO purified from production residues (PGO). Stigmas were then hand-pollinated and GRM deposition was checked by ESEM and confocal microscopy. Analysis of stigma integrity, pH homeostasis and pollen-stigma interactions did not reveal negative effects. Fruit and seed production were not affected, but GO depositions of 22.1 ± 7.2 ng mm-2 affected the normal development of seeds, decreasing seed dimensions, seed germination and germination speed. The elemental analysis revealed that GO has significant quantities of production residues, such as strong acids and oxidants, while PGO has only traces, which justifies the differences observed in the effects caused by the two materials. Our results show that GO depositions of up to 11.1 ± 3.6 ng mm-2, which fall within the variation range of total dry particulate matter depositions reported in the literature, are safe for reproduction of C. pepo. This is the first "safety" limit ever recorded for depositions of "out-of-the-box" GO concerning the reproduction of a seed plant. If confirmed for wind-pollinated species, it might be considered for policymaking of GRMs emissions in the air.

Simultaneous detection of ten kinds of insecticide residues in honey and pollen using UPLC-MS/MS with graphene and carbon nanotubes as adsorption and purification materials.

An analytical method of simultaneous detection of ten insecticide residues in honey and pollen was established. The samples were purified with QuEChERS approach using new adsorbents and analyzed with UPLC-MS/MS. The results showed that both of graphene and carbon nanotubes were highly efficient adsorbents for the dSPE clean up to eliminate coextractives in the samples, and graphene was superior to carbon nanotubes for the detection of pesticide residues in honey and pollen samples. The proposed method was used to detect pesticide residues in 25 honey samples and 30 pollen samples which were randomly collected from more than ten provinces in China. All honey samples contain 1-27 µg/kg of chlorpyrifos residues. Only 4% of the honey samples were detected containing acetamiprid and imidacloprid, while the other seven pesticides were not detected. Chlorpyrifos residues were found in all pollen samples (5-66 µg/kg), among which twenty percent exceeded the maximum residue limits (MRLs, 50 µg/kg, European Commission Regulation). Most of the pollen samples containing pesticide concentrations higher than MRLs were collected from rape, followed by lotus, camellia, and rose. Besides, 36.7% and 33.3% of the pollen samples had imidacloprid and flupyradifurone higher than 5 µg/kg. A total of 26.7% pollen samples were detected containing bifenthrin, while none of the other six pesticides were detected in pollen samples.

Multiphysical analysis of nanoparticles and their effects on plants.

Nanoparticles are the magic bullets and at the leading edge in the field of nanotechnology, and their unique properties make these materials indispensable and superior in many areas, including the electronic field. Extensive applications of nanomaterials are incontrovertibly entering our living system. The increasing use of nanomaterials into the ecosystem is one of the crucial environmental factors that human being is facing. Nanomaterials raise noticeable toxicological concerns; particularly their accumulation in plants and the resultant toxicity may affect the food chain. Here, we analyzed the characterization of nanomaterials, such as graphene, Al2 O3 , TiO2 , and semi-insulating or conducting nanoparticles. Quantitative evaluation of the nanomaterials was conducted and their commercialization aspects were discussed. Various characterization techniques, scanning electron microscopy, X-ray diffraction, and ultraviolet rays were utilized to identify the morphology, phase, absorbance, and crystallinity. In addition, we analyzed the effects of nanomaterials on plants. The toxicity of nanoparticles has severe effects on loss of morphology of the plants. Potential mechanisms including physical and physiological effects were analyzed. In future studies, it is indispensable to assess widely accepted toxicity evaluation for safe production and use of nanomaterials.

Mineralogy, Structure, and Habitability of Carbon-Enriched Rocky Exoplanets: A Laboratory Approach.

Carbon-enriched rocky exoplanets have been proposed to occur around dwarf stars as well as binary stars, white dwarfs, and pulsars. However, the mineralogical make up of such planets is poorly constrained. We performed high-pressure high-temperature laboratory experiments (P = 1-2 GPa, T = 1523-1823 K) on chemical mixtures representative of C-enriched rocky exoplanets based on calculations of protoplanetary disk compositions. These P-T conditions correspond to the deep interiors of Pluto- to Mars-sized planets and the upper mantles of larger planets. Our results show that these exoplanets, when fully differentiated, comprise a metallic core, a silicate mantle, and a graphite layer on top of the silicate mantle. Graphite is the dominant carbon-bearing phase at the conditions of our experiments with no traces of silicon carbide or carbonates. The silicate mineralogy comprises olivine, orthopyroxene, clinopyroxene, and spinel, which is similar to the mineralogy of the mantles of carbon-poor planets such as the Earth and largely unaffected by the amount of carbon. Metals are either two immiscible iron-rich alloys (S-rich and S-poor) or a single iron-rich alloy in the Fe-C-S system with immiscibility depending on the S/Fe ratio and core pressure. We show that, for our C-enriched compositions, the minimum carbon abundance needed for C-saturation is 0.05-0.7 wt% (molar C/O ∼0.002-0.03). Fully differentiated rocky exoplanets with C/O ratios more than that needed for C-saturation would contain graphite as an additional layer on top of the silicate mantle. For a thick enough graphite layer, diamonds would form at the bottom of this layer due to high pressures. We model the interior structure of Kepler-37b and show that a mere 10 wt% graphite layer would decrease its derived mass by 7%, which suggests that future space missions that determine both radius and mass of rocky exoplanets with insignificant gaseous envelopes could provide quantitative limits on their carbon content. Future observations of rocky exoplanets with graphite-rich surfaces would show low albedos due to the low reflectance of graphite. The absence of life-bearing elements other than carbon on the surface likely makes them uninhabitable.

Image-guided synergistic photothermal therapy using photoresponsive imaging agent-loaded graphene-based nanosheets.

We report the image-guided synergistic photothermal antitumor effects of photoresponsive near-infrared (NIR) imaging agent, indocyanine green (ICG), by loading onto hyaluronic acid-anchored, reduced graphene oxide (HArGO) nanosheets. Loading of ICG onto either rGO (ICG/rGO) or HArGO (ICG/HArGO) substantially improved the photostability of photoresponsive ICG upon NIR irradiation. After 1min of irradiation, the NIR absorption peak of ICG almost disappeared whereas the peak of ICG on rGO or HArGO was retained even after 5min of irradiation. Compared with plain rGO, HArGO provided greater cellular delivery of ICG and photothermal tumor cell-killing effects upon laser irradiation in CD44-positive KB cells. The temperature of cell suspensions treated with ICG/HArGO was 2.4-fold higher than that of cells treated with free ICG. Molecular imaging revealed that intravenously administered ICG/HArGO accumulated in KB tumor tissues higher than ICG/rGO or free ICG. Local temperatures in tumor tissues of laser-irradiated KB cell-bearing nude mice were highest in those intravenously administered ICG/HArGO, and were sufficient to trigger thermal-induced complete tumor ablation. Immunohistologically stained tumors also showed the highest percentages of apoptotic cells in the group treated with ICG/HArGO. These results suggest that photoresponsive ICG-loaded HArGO nanosheets could serve as a potential theranostic nano-platform for image-guided and synergistic photothermal antitumor therapy.

The use of pencil lead as a matrix and calibrant for matrix-assisted laser desorption/ionisation.

Pencil lead is shown to be an effective matrix and calibrant in matrix-assisted laser desorption/ionisation (MALDI) mass spectrometry. Various groups of analytes, including peptides, polymers and actinide metals, can be readily ionised using MALDI when deposited onto a pencil lead matrix. The matrix is seen to have advantages in sample preparation relating to its hydrophobic properties and almost complete suppression of the matrix during analysis. Using pencil lead as a matrix is a quick and convenient method of qualitative analysis and has been shown to be quantitative for the isotope ratio analysis of actinide metals.

Determination of urinary beryllium, arsenic, and selenium in steel production workers.

Some of the most pernicious dangers of pollution arise from the presence of traces of toxic elements in the environment. In this work, we report on the determination of beryllium, arsenic, and selenium in the urine of steel production and steel quality control (QC) workers, in comparison to healthy control subjects. The urine samples were digested by a microwave system. Graphite furnace and hydride atomic absorption was used for the quantitative measurements of Be and As and Se, respectively. A quality control method for these procedures was established with concurrent analysis of Standard Trace Metals 7879 Level II and NIST SRM 2670 (Toxic Elements in Freeze Dried Urine). The results show that the urinary levels of these elements in steel production (As, 38.1 +/- 28.7 microg/L; Be, 1.58 +/- 0.46 microg/L, and Se, 69.2 +/- 28.8 +/- g/L) and in quality control workers (As, 23.9 +/- 18.1 microg/L; Be, 1.58 +/- 0.46 microg/L, and Se, 54.8 +/- 25.1 microg/L) are significantly higher than in the controls (As, 10.3 +/- 8.7 microg/L; Be, 0.83 +/- 0.46 microg/L; and Se, 32.3 +/- 13.5 microg/L). The possible connection of these elements with the etiology of disease and the possible role of selenium as a protective agent against the oncogenic and teratogenic action of other substances is discussed. We suggest the need for improvement of environmental conditions in the workplace through better ventilation and industrial hygiene practices.

Electric interactions between dust and hot plasmas in the solar system.

Interaction of the charged particles of a plasma with a solid body is an old problem which has been investigated under various conditions, in particular by the authors in several papers. However, the electric potential of the grains may be more sensitive than expected to the physical state of grain matter and the physical parameters of plasmas in the solar system. Using a new model accounting for porosity, a characteristic feature of grains observed in the solar system, we have investigated the secondary electron emission under electron impact for porous materials. The conclusion is that porosity has a significant influence on the rate of electron ejection. It follows that the floating potential of porous grains can be different from that of grains made of bulk material, with consequences for grain dynamics in the environment of planets or comets.