Advances in Electrochemical Detection Electrodes for As(III).

Arsenic is extremely abundant in the Earth's crust and is one of the most common environmental pollutants in nature. In the natural water environment and surface soil, arsenic exists mainly in the form of trivalent arsenite (As(III)) and pentavalent arsenate (As(V)) ions, and its toxicity can be a serious threat to human health. In order to manage the increasingly serious arsenic pollution in the living environment and maintain a healthy and beautiful ecosystem for human beings, it is urgent to conduct research on an efficient sensing method suitable for the detection of As(III) ions. Electrochemical sensing has the advantages of simple instrumentation, high sensitivity, good selectivity, portability, and the ability to be analyzed on site. This paper reviews various electrode systems developed in recent years based on nanomaterials such as noble metals, bimetals, other metals and their compounds, carbon nano, and biomolecules, with a focus on electrodes modified with noble metal and metal compound nanomaterials, and evaluates their performance for the detection of arsenic. They have great potential for achieving the rapid detection of arsenic due to their excellent sensitivity and strong interference immunity. In addition, this paper discusses the relatively rare application of silicon and its compounds as well as novel polymers in achieving arsenic detection, which provides new ideas for investigating novel nanomaterial sensing. We hope that this review will further advance the research progress of high-performance arsenic sensors based on novel nanomaterials.

Risk of Neurological Toxicities Following the Use of Different Immune Checkpoint Inhibitor Regimens in Solid Tumors: A Systematic Review and Meta-analysis.

OBJECTIVES: The objective of this study was to assess risk of neurological toxicities following the use of different immune checkpoint inhibitor (ICI) regimens in solid tumors. METHODS: Pubmed, Embase, and ClinicalTrials.gov databases were searched for publications, and data were analyzed using Review Manager 5.3 software to compare the risk of immune-related and nonspecific neurological complications potentially triggered by ICIs to controls. RESULTS: In total 23 randomized clinical trials comprising 11,687 patients were included in this meta-analysis. Patients with PD-L1 (OR, 0.29; 95% confidence interval [CI], 0.18-0.48; P<0.01) or programmed cell-death protein 1 (PD-1) inhibitor (OR, 0.21; 95% CI, 0.14-0.31; P<0.01) were less likely to develop any-grade peripheral neuropathy than chemotherapy, while the risk of grade 3-5 was also smaller for PD-1 inhibitor (OR, 0.16; 95% CI, 0.05-0.54; P=0.003). Combination therapy with CTLA4 and PD-1 inhibitor did not significantly increase the risk of any-grade (OR, 0.83; 95% CI, 0.21-3.32; P>0.05) or grade 3-5 (OR, 1.4; 95% CI, 0.2-9.61; P>0.05) peripheral neuropathy compared to monotherapy with CTLA4 or PD-1 inhibitor. However, difference in risk of immune-related adverse events (irAEs) involving central nervous system did not reach statistical significance in patients with different ICI regimens compared those under chemotherapy. Additionally, risk of experiencing paresthesia was in line with that of peripheral neuropathy (OR, 0.42; 95% CI, 0.28-0.62; P<0.01). CONCLUSIONS: This meta-analysis shows that PD-L1/PD-1 and CTLA4 inhibitor have decreased risk of peripheral neuropathy compared to chemotherapy, while combination therapy with CTLA4 and PD-1 inhibitor have no difference in neurological toxicities compared to monotherapy with CTLA4 or PD-1 inhibitor.

One-Step Synthesis of Dendritic Highly Branched Polystyrenes by Organotellurium-Mediated Copolymerization of Styrene and a Dienyl Telluride Monomer.

Dendritic highly branched polystyrenes (HB-PSts) were prepared by a one-step copolymerization of dienyl telluride 6 and St in the presence of organotellurium chain transfer agent 2. The molecular weight (MW), dendritic generation, and branching density were easily controlled by the ratio of 2 to 6 to styrene (St) with maintaining monodispersity. The branching efficiency estimated by a deuterium-labeling experiment showed that 6 quantitatively (>95 %) served as the branching point. The end group fidelity was high (ca. 90 %) as determined by the end group transformation to pyrene-derivative. Intrinsic viscosity of the HP-polystyrenes was significantly lower than that of linear polystyrenes and were easily tuned by the branching number and branching density. The method is compatible of various functional groups and chloro and acetoxy-substituted styrenes were also used as a comonomer. A tadpole block copolymer was also synthesized starting from linear PSt as a macroinitiator.

Synthesis of structurally controlled hyperbranched polymers using a monomer having hierarchical reactivity.

Hyperbranched polymers (HBPs) have attracted significant attention because of their characteristic topological structure associated with their unique physical properties compared with those of the corresponding linear polymers. Dendrimers are the most structurally controlled HBPs, but the necessity of a stepwise synthesis significantly limits their applications in materials science. Several methods have been developed to synthesize HBPs by a one-step procedure, as exemplified by the use of AB2 monomers and AB' inimers under condensation and self-condensing vinyl polymerization conditions. However, none of these methods provides structurally controlled HBPs over the three-dimensional (3D) structure, i.e., molecular weight, dispersity, number of branching points, branching density, and chain-end functionalities, except under special conditions. Here, we introduce a monomer design concept involving two functional groups with hierarchical reactivity and demonstrate the controlled synthesis of dendritic HBPs over the 3D structure by the copolymerization of the designed monomer and acrylates under living radical polymerization conditions.