[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. The forms of arsenic in environmental water are diverse, which can easily be transformed into each other during the sampling process and transportation, resulting in errors in laboratory analysis results. Therefore, developing on-site analytical methods for arsenic and acquiring accurate data are the basis for the study of the morphological transformation and bio-absorption process of arsenic and accurately evaluating its toxicity. In the past few decades, laboratory-based analytical methods for arsenic have developed rapidly, but there are still huge challenges in the on-site analysis of arsenic. This review summarized the relevant reviews on analytical methods of arsenic in environmental water in the past decade (2011-2022); discussed the advances in on-site analytical methods such as colorimetric methods, luminescence-based methods, and electrochemical methods of arsenic; anticipated the future development of on-site analytical methods for arsenic in environmental waters; and provided references for the development and applications of new methods.

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. Therefore, structure-level qualitative analysis with high sensitivity and accuracy is vitally important. Characterized by fingerprinting recognition, Raman spectroscopy, especially surface-enhanced Raman spectroscopy (SERS), has become an essential qualitative analysis tool in various fields, such as environmental monitoring and food safety. With the exception of chirality, this study completed the qualitative trace analysis of 16 quinolone antibiotics (QNs) with fine molecular structure differences using SERS. The sensitivity was tuned in by one order of magnitude through the different electronegativity and steric hindrances of the slightly changed functional groups in the specific antibiotics. The fine structure dependent sensitivity enables SERS to be a powerful on-site monitoring tool to control the abuse of antibiotics with high toxicity; thus, decreasing the subsequent risk to the environmental ecology and human society.

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. HCC tissues with lower miR-34a expression displayed higher expression of Bcl-2 protein than those with high expression of miR-34a; therefore, an inverse correlation is evident between the miR-34a level and Bcl-2 expression. Moreover, patients with lower miR-34a expression had significantly poorer overall survival. Bioinformatics and luciferase reporter assays revealed that miR-34a binds the 3'-UTR of the Bcl-2 mRNA and represses its translation. Western blotting analysis and qRT-PCR confirmed that Bcl-2 is inhibited by miR-34a overexpression. Functional analyses indicated that the restoration of miR-34a reduced cell viability, promoted cell apoptosis and potentiated sorafenib-induced apoptosis and toxicity in HCC cell lines by inhibiting Bcl-2 expression. This study is the first to demonstrate that miR-34a induces sensitivity to the anti-tumor effect of sorafenib in human HCC cells, suggesting a potential role of miR-34a in the treatment of HCC.

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. To trace FLSPCs, the GFP gene was introduced into FLSPCs by liposome-mediated transfection. RESULTS: For amplifying FLSPCs, the soft agar culture were more suitable than the adherent culture, because the soft agar culture obtained more homogeneous cells. These cells were with high nuclear:cytoplasmic ratio, few cell organelles, high expression of CD90.1 and CD49f, and strong alkaline phosphatase staining. For inducing FLSPCs differentiation, treatment with HGF+DMSO was most effective (P<0.05), which was strongly supported by the typical morphological change and the significant decrease of OV-6 positive cells (P<0.01). In addition, the time of indocyanine green elimination, the percentage of glycogen synthetic cells, and the expressions of ALB, G-6-P, CK-8, CK-18 and CYP450-3A1 in HGF+DMSO-treated group were higher than in any other group. For tracing FLSPCs, after the selection of stable FLSPC transfectants, GFP expression continued over successive generations. CONCLUSIONS: FLSPCs can properly self-renew in soft agar culture and effectively differentiate into hepatocyte-like cells by HGF+DMSO induction, and they can be reliably traced by GFP expression.

[High current microsecond pulsed hollow cathode lamp excited ionic fluorescence spectrometry of alkaline earth elements in inductively coupled plasma with a Fassel-torch].

High current microsecond pulsed hollow cathode lamp (HCMP-HCL) excited ionic fluorescence spectrometry (IFS) of alkaline earth elements in inductively coupled plasma (ICP) with a Fassel-torch has been investigated. In wide condition ranges only IFS was observed, whilst atomic fluorescence spectrometry (AFS) was not detectable. More intense ionic fluorescence signal was observed at lower observation heights and at lower incident RF powers. Without introduction of any reduction organic gases into the ICP, the limit of detection (LOD, 3sigma) of Ba was improved by 50-fold over that of a conventional pulsed (CP) HCL with the Baird sleeve-extended torch. For Ca and Sr, the LODs by HCMP-HCL-ICP-IFS and CP-HCL-ICP-AFS show no significant difference. Relative standard deviations were 0.6%-1.4% (0.1-0.2 microg x mL(-1), n = 10) for 5 ionic fluorescence lines. Preliminary studies showed that the intensity of ionic fluorescence could be depressed in the presence of K, Al and P.

[Atomic/ionic fluorescence in microwave plasma torch discharge with excitation of high current and microsecond pulsed hollow cathode lamp: Ca atomic/ionic fluorescence spectrometry].

A system of atomic and ionic fluorescence spectrometry in microwave plasma torch (MPT) discharge excited by high current microsecond pulsed hollow cathode lamp (HCMP HCL) has been developed. The operation conditions for Ca atomic and ionic fluorescence spectrometry have been optimized. Compared with atomic fluorescence spectrometry (AFS) in argon microwave induced plasma (MIP) and MPT with the excitation of direct current and conventional pulsed HCL, the system with HCMP HCL excitation can improve AFS and ionic fluorescence spectrometry (IFS) detection limits in MPT atomizer and ionizer. Detection limits (3 sigma) with HCMP HCL-MPT-AFS/IFS are 10.1 ng.mL-1 for Ca I 422.7 nm, 14.6 ng.mL-1 for Ca II 393.4 nm, and 37.4 ng.mL-1 for Ca II 396.8 nm, respectively.