Multielement electrochemical vapor generation system coupled with atomic fluorescence spectrometer for simultaneous measurement of trace levels of As and Hg in coastal seawater samples.

Background: Toxic elements As and Hg in coastal waters affect human health through the food chain even at trace levels. The simultaneous determination of As and Hg in seawater using electrochemical vapor generation (ECVG) with atomic fluorescence spectrometer (AFS) currently has technical bottlenecks. One is the need for a simple and efficient chemical reaction cell and corresponding parameters to generate both AsH and Hg vapors, and the other is a suitable preservation method of the mixed standard solutions.

Mesenchymal stem cells may alleviate angiotensin II-induced myocardial fibrosis and hypertrophy by upregulating SFRS3 expression.

Introduction And Objectives: The development of cardiac fibrosis (CF) and hypertrophy (CH) can lead to heart failure. Mesenchymal stem cells (MSCs) have shown promise in treating cardiac diseases. However, the relationship between MSCs and splicing factor arginine/serine rich-3 (SFRS3) remains unclear.

On-site monitoring of dissolved Sb species in natural waters by an automatic system using flow injection coupled with hydride generation atomic fluorescence spectrometer.

Antimony (Sb) is a toxic and potentially carcinogenic element in the environment. The toxicity of Sb(III) is ten times that of Sb(V). Therefore, on-site monitoring technique for dissolved Sb species is crucial for the study of Sb environmental processes.

Why is Superlubricity of Diamond-Like Carbon Rare at Nanoscale?

Hydrogenated diamond-like carbon (HDLC) is a promising solid lubricant for its superlubricity which can benefit various industrial applications. While HDLC exhibits notable friction reduction in macroscale tests in inert or reducing environmental conditions, ultralow friction is rarely observed at the nanoscale. This study investigates this rather peculiar dependence of HDLC superlubricity on the contact scale.

Unveiling the tribological potential of MXenes-current understanding and future perspectives.

Reducing energy consumption and CO emissions by improving the tribological performance of mechanical systems relies on the development of new lubrication concepts. Two-dimensional (2D) materials have been the subject of extensive tribological research due to their unique physical and chemical properties. 2D transition metal carbides, nitrides, and carbonitrides (MXenes), with their tuneable chemistry and structure, are a relatively new addition to the family of 2D materials.

Simultaneous Measurement of Trace Levels of Hg, As, Sb, and Bi in Coastal Seawater with a Multichannel Chemical Vapor Generation Atomic Fluorescence Spectrometer.

Trace levels of Hg, As, Sb, and Bi in coastal seawater have been simultaneously detected by a laboratory-built multichannel chemical vapor generation coupled to an atomic fluorescence spectrometer. The system was configured with a built-in electrochemical H generator as the fuel supplier to replace chemical H produced by the oxidation of potassium borohydride under acidic conditions in traditional instruments. The electrochemical H generator not only isolated the atomization process from the chemical vapor injection process but also improved the stability of atomization, excitation, and fluorescence emission in the hydrogen flame, making it easier to optimize conditions for CVG while introducing evaporating multielement vapors.

Shipboard determination of arsenite and total dissolved inorganic arsenic in estuarine and coastal waters with an automated on-site-applicable atomic fluorescence spectrometer.

The speciation of trace level arsenic (As) in estuarine and coastal waters is crucial for both biogeochemical and toxicological studies of this toxic metalloid. However, the accurate and on-site determination of As in complex seawater matrices is challenging because of the low concentration of As, the easy conversion of arsenite (As(III)) to arsenate (As(V)), and the considerable effect of salinity on the determination of As via conventional methods. In this study, a custom-made shipboard atomic fluorescence spectrometer (AFS) is reported for the on-site speciation of inorganic As in estuarine and coastal waters.

[Advances in On-site Analytical Methods for Inorganic Arsenic in Environmental Water].

Arsenic is a ubiquitous metalloid element in the environment. Arsenic is classified as a group A carcinogen and has caused serious impacts on human health. For example, chronic poisoning caused by arsenic in groundwater is a global health problem.

Source tracing and health risk assessment of phthalate esters in household tap-water: A case study of the urban area of Quanzhou, Southeast China.

The occurrence of phthalate esters (PAEs) in household tap water has been investigated via the presence of their geochemical characteristics in the pretreatment and transfer processes of water plants in the urban and suburban areas of the subtropical medium-sized city of Quanzhou, southeast China. The results for all approximately 300 tap water samples collected from 6 sampling stations at household kitchens from Nov. 30, 2017, to Dec.

The association between blood albumin level and cardiovascular complications and mortality risk in ICU patients with CKD.

Background: Studies involving the association of blood albumin with prognosis in patients with chronic kidney disease (CKD) during intensive care unit (ICU) were scarce.

Aim: We investigated whether reduced blood albumin level independently associated with an increased risk of cardiovascular (CV) complications and 1-year mortality risk in ICU patients with CKD.

Methods: The Medical Information Mart for Intensive Care III (MIMIC-III) database was used.

Qualitative analysis of trace quinolone antibiotics by SERS with fine structure dependent sensitivity.

Antibiotics are widely used in daily life, which has created a global scenario where many pathogenic organisms have become effectively resistant to antibiotics. The abuse or overuse of antibiotics causes significant environmental pollution and even endangers human health. It is well-known that antibiotics' efficacy (toxicity) is determined by molecular structure.

Toward a versatile flow technique: Development and application of reverse flow dual-injection analysis (rFDIA) for determining dissolved iron redox species and soluble reactive phosphorus in seawater.

A versatile flow analyzer that extended the features of reverse flow injection analysis (rFIA) was developed in this study and named reverse flow dual-injection analysis (rFDIA). Compared with typical rFIA, the analyzer requires less reagent and is more environmentally friendly, which has two injection valves and two reagent loops for the accurate and successive injection of two reagents. With a 2-m long liquid waveguide capillary cell (LWCC) and a spectrophotometer, the analyzer was applied to underway determination of dissolved iron redox species in estuarine and coastal waters.

The pivotal role of oxygen in establishing superlow friction by inducing the in situ formation of a robust MoS transfer film.

The achievement of superlow friction is vital for the engineering application of hydrogenated diamond-like carbon (H-DLC), but it always fails in an oxygen atmosphere. In this paper, robust superlow friction was achieved by MoS flakes and H-DLC composite films in a large range of atmospheres, especially in oxygen. The results showed that the composite structure could only retain the superlow friction for an short time in pure argon, nitrogen and carbon dioxide; surprisingly, oxygen was capable of remaining in the near frictionless state with a friction coefficient as low as 0.

Preparation of a novel monolith-based adsorbent for solid-phase microextraction of sulfonamides in complex samples prior to HPLC-MS/MS analysis.

Effective extraction is an essential step in the sensitive and accurate analysis of sulfonamides (SAs) in complex samples. In this study, based on the chemical properties of SAs, a novel monolith-based adsorbent using 4-vinylbenzoic acid and 4-vinylphenylboronic acid as dual-functional monomers was tailored and employed as efficient extraction phase of solid-phase microextraction. Various characterized techniques were applied to investigate the structure and morphology of the obtained adsorbent.

Spatial distribution and seasonal variation of phthalate esters in the Jiulong River estuary, Southeast China.

The spatial distribution and seasonal variation of 16 phthalate esters (PAEs) in water, suspended particulate matter (SPM) and sediment were investigated in the Jiulong River estuary, Fujian, Southeast China. Of the 16 PAE congeners analyzed, only six PAEs, including dimethyl phthalate (DMP), diethyl phthalate (DEP), diisobutyl phthalate (DIBP), di-n-butyl phthalate (DBP), di(2-ethylhexyl) phthalate (DEHP) and diisononyl phthalate (DINP), were identified and quantified. The total concentrations of the six PAEs (∑PAEs) detected for all seasons ranged from 3.

Occurrence, spatial distribution, historical trend and ecological risk of phthalate esters in the Jiulong River, Southeast China.

The occurrence and spatial distribution of phthalate esters (PAEs) in the Jiulong River of southeast China were investigated in water and sediment samples collected from 35 stations along the river in Mar. 2014. The historical trend of the past 26years was reconstructed with a sediment core collected in Dec.

COMMD7 functions as molecular target in pancreatic ductal adenocarcinoma.

Our previous studies provided evidence that COMMD7 was associated with tumor progression in human solid cancer. Herein, we aimed to investigate its expression pattern, clinical significance, and biological function in pancreatic ductal adenocarcinoma (PDAC). We found that high COMMD7 expression was specifically detected in PDAC tissues and PDAC cell lines.

Removal of high-salinity matrices through polymer-complexation-ultrafiltration for the detection of trace levels of REEs using inductively coupled plasma mass spectrometry.

The polymer-complexation-ultrafiltration (PCUF) technique was applied to separate trace levels of rare earth elements (REEs), including scandium, yttrium and the lanthanides, from high-salinity matrices prior to their determination by inductively coupled plasma mass spectrometry (ICP-MS). The REEs were converted into REE-polymer complexes using the water-soluble polymer polyacrylic acid (PAA) at a specified pH, retained on the ultrafiltration membrane of centrifugal filter units, and finally eluted using diluted nitric acid to achieve separation from matrices with relatively high levels of various inorganic ions, such as sodium, potassium, calcium, magnesium, and chlorine ions. Numerous factors affecting the PCUF efficiency were optimized.

[Determination of N-nitrosamines in rubber products by solid phase extraction purification and ultra high performance liquid chromatography-tandem mass spectrometry].

A method using C18 solid phase extraction (SPE) for purification and ultra high performance liquid chromatography (UHPLC) coupled with electrospray ionization tandem mass spectrometry (ESI-MS/MS) for detection was developed to simultaneously determine 13 N-nitrosamines in rubber products. The analytes were extracted with methanol (60 degrees C, 30 min) with the aid of ultrasonic technique and then purified by a C18 SPE cartridge. The analytes were separated on a C18 chromatographic column and qualitatively and quantitatively detected by a mass spectrometer with positive ESI at multiple reaction monitoring (MRM) mode.

[Determination of carcinogenic aromatic amines derived from azo colorants in textiles and leather by ultra high performance liquid chromatography-tandem mass spectrometry].

A rapid determination method was developed for the quantification and confirmation of 22 carcinogenic aromatic amines derived from azo colorants in textiles and leather by ultra high performance liquid chromatography-tandem electrospray ionization mass spectrometry (UHPLC-MS/MS). The methods of EN 14362-1:2012 (for textiles) and ISO 17234-1:2010 (for leather) were adopted for sample pretreatment, finally diluted with methanol. The target compounds were separated by an Eclipse XDB-C18 RRHD column and eluted with methanol and water in gradient, and then determined by positive electrospray ionization mass spectrometry under multiple reaction monitoring (MRM) mode.

MicroRNA-34a targets Bcl-2 and sensitizes human hepatocellular carcinoma cells to sorafenib treatment.

MiR-34a, a direct target of p53, has been shown to target several molecules associated with the cell cycle and cell survival pathways, and its dysregulation is implicated in cancer drug resistance or sensitivity in several human cancers. However, the correlation between miR-34a expression and chemoresistance has not been explored in HCC. In this study, we confirmed that miR-34a was significantly down-regulated in HCC tissues and HCC cell lines by qRT-PCR.

Several important in vitro improvements in the amplification, differentiation and tracing of fetal liver stem/progenitor cells.

Objective: We previously isolated fetal liver stem/progenitor cells (FLSPCs), but there is an urgent need to properly amplify FLSPCs, effectively induce FLSPCs differentiation, and steadily trace FLSPCs for in vivo therapeutic investigation.

Methods: FLSPCs were maintained in vitro as adherent culture or soft agar culture for large-scale amplification. To direct the differentiation of FLSPCs into hepatocytes, FLSPCs were randomly divided into four groups: control, 1% DMSO-treated, 20 ng/ml HGF-treated and 1% DMSO+20 ng/ml HGF-treated.

[Determination of four Sudan dyes in chili oil by high performance liquid chromatography with on-line photochemical derivatization and fluorescence detection].

A method for the measurement of Sudan I, Sudan II, Sudan III and Sudan B in chili oil using high performance liquid chromatography (HPLC) with on-line photochemical derivatization and fluorescence detection has been developed. The Sudan dyes were separated on an SB-C18 column in a single run by the mixed mobile phase of acetonitrile-water with a gradient program. A laboratory-built time/energy programmed photochemical reactor (PCR) with an ultraviolet mercury lamp was installed between a photodiode array detector (PDA) and a fluorescence detector (FLD), and it was applied to convert the non-or weakly fluorescent Sudan dyes into fluorescence emission components.

[Simultaneous determination of 19 phthalate esters in cosmetics using gas chromatography-mass spectrometry].

A method was developed for the simultaneous determination of 19 phthalate esters (PAEs) at trace level in cosmetics by solid phase extraction (SPE) purification and gas chromatography-mass spectrometry (GC-MS) detection. The PAEs were extracted from cosmetic samples by dichloromethane with ultrasonic-assisted technique, purified by an SPE column packed with silica gel and neutral alumina (2: 3, m/m) with the elution of 20 mL of mixed solvent of ethyl acetate-hexane (8: 2, v/v). Qualitative and quantitative analysis were carried out by GC-MS in full scan and selected ion monitoring modes.

Prognostic significance of metadherin overexpression in hepatitis B virus-related hepatocellular carcinoma.

Metadherin (MTDH), which is an HIV-1 or TNF-α-inducible transcript, has a crucial role in several types of cancer by regulating multiple cellular signaling processes. However, to date, the role of MTDH in hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) is still unclear. In the present study, we detected MTDH expression in normal liver, chronic hepatitis B and HBV-related HCC tissues.