Transformations of organic micropollutants undergoing permanganate/bisulfite treatment: Kinetics, pathways and toxicity.

Permanganate/bisulfite (PM/BS) is a relatively new advanced oxidation process that can degrade organic micropollutants at extraordinary high rates. In this study, the degradability of PM/BS process towards different representative types of compounds was studied by investigating the kinetics, reaction site specificity and transformation chemistry. Acesulfame (ACE) and carbamazepine (CBZ) were two typical compounds containing olefinic moieties.

Optical properties, source apportionment and redox activity of humic-like substances (HULIS) in airborne fine particulates in Hong Kong.

Humic-like substances (HULIS) account for a considerable fraction of water-soluble organic matter (WSOM) in ambient fine particulates (PM) over the world. However, systemic studies regarding the chemical characteristics, sources and redox activity of HULIS are still limited. In this study, the mass concentration, optical properties, and reactive oxygen species (ROS)-generation potential of HULIS were investigated in PM samples collected in Hong Kong during 2011-2012, and they all showed higher levels on days under regional pollution than on days under long range transport (LRT) pollution and local emissions.

Chirality Transfer in Galvanic Replacement Reactions.

Demand for the transfer of chirality from a pre-engineered nanoparticle to any other metal is of fundamental importance for developing a wide range of chirality-related applications. Herein, we show that binary alloy chiral nanoparticles (CNPs) with an engineerable composition can be formed from metallic CNPs with intrinsic structural chirality serving as sacrificial templates (STs), via a galvanic replacement reaction (GRR). This GRR-mediated chirality transfer is a general phenomenon and results in the formation of Cu-Ag CNPs with solid morphology and mesoporous CNPs made of Ag-Au, Ag-Pt, and Ag-Pd.

Integration of sub-organ quantitative imaging LA-ICP-MS and fractionation reveals differences in translocation and transformation of CeO and Ce in mice.

Information on the risk of exposure to cerium oxide (CeO) nanoparticles (NPs) is limited. To assess risk, we must know where and how such NPs are distributed to the body after exposure, both short- and long-term. In this work, an integrated approach of quantitative LA-ICP-MS bioimaging and fractionation was employed to study the translocation and transformation of CeO and Ce in mouse spleen and liver.

Sorption and desorption of organic UV filters onto microplastics in single and multi-solute systems.

Sorption studies of organic pollutants by microplastics (MPs) in single-solute systems are well established in the literature. However, actual aquatic environments always contain a mixture of contaminants. Prediction of the fate and biological effects of MPs-mediated chemical exposure requires a better understanding of sorption-desorption processes of multiple organic contaminants by MPs.

Fate of UV filter Ethylhexyl methoxycinnamate in rat model and human urine: Metabolism, exposure and demographic associations.

Ethylhexyl methoxycinnamate (EHMC) is one of the most frequently used UV filters in sunscreens and other cosmetic products. Its ubiquitous presence in various environmental matrices and its endocrine disrupting properties have been widely reported. However, we know little about the effect of EHMC exposure on humans, mainly due to its fast metabolism.

Synthesis of the Tricyclic Picrotoxane Motif by an Oxidative Cascade Cyclization.

An oxidative cascade cyclization of β-keto esters has been developed for the construction of the tricyclic picrotoxane motif in a single step, and DFT calculations suggested a possible cationic cyclization mechanism. This cascade cyclization can be operated on a 20 g scale to obtain a 77% total yield of the tricyclic products, which in turn can be converted to versatile intermediates for further elaboration to picrotoxanes and their structurally related compounds.

Symmetrically backfolded molecules emulating the self-similar features of a Sierpinski triangle.

We synthesized self-similar molecules (G3 and G2; based on phenylalkynyl backbones) with symmetrically backfolded shapes inspired by the famous fractal of a Sierpinski triangle. Unlike the more traditional, starburst dendrimers, the centripetal-shaped Sierpinski molecules feature side branches symmetrically bent away from the growth direction of the main branch, thus contrasting the natural-tree shape. Molecule G3 exhibits three distinct levels of the structural hierarchy comprising the primary, secondary and tertiary branches, while the smaller G2 contains only features of the 1 and 2 orders.

Energy Transfer between Tb and Eu in LaPO: Pulsed versus Switched-off Continuous Wave Excitation.

The energy transfer (ET) between Tb and Eu is investigated experimentally and with available theoretical models in the regime of high Tb concentrations in ≈30 nm LaPO nanoparticles at room temperature. The ET efficiency approaches 100% even for lightly Eu-doped materials. The major conclusion from the use of pulsed laser excitation and switched-off continuous wave laser diode excitation is that the energy migration between Tb ions, situated on La sites with ≈4 Å separation, is not fast.

Fabrication of Nickel Oxide Nanopillar Arrays on Flexible Electrodes for Highly Efficient Perovskite Solar Cells.

Semiconductor nanomaterials with controlled morphologies and architectures are of critical importance for high-performance optoelectronic devices. However, the fabrication of such nanomaterials on polymer-based flexible electrodes is particularly challenging due to degradation of the flexible electrodes at a high temperature. Here we report the fabrication of nickel oxide nanopillar arrays (NiO NaPAs) on a flexible electrode by vapor deposition, which enables highly efficient perovskite solar cells (PSCs).

Quantifying silver nanoparticle association and elemental content in single cells using dual mass mode in quadrupole-based inductively coupled plasma-mass spectrometry.

In this study, a method of simultaneous dual mass detection for single cell analysis by quadrupole-based ICP-MS (ICP-QMS) is proposed. The method shows potential for use in quantitative investigations of nanoparticle association and elemental composition of cells. Dual mass detection had been attempted in the analysis of two-element core-shell nanoparticles and in isotope dilution analysis.

Removing acesulfame with the peroxone process: Transformation products, pathways and toxicity.

Emerging contaminants (ECs) are receiving considerable attention because of their widespread occurrence, persistence and potential threat to the environment, wildlife and humans. Acesulfame (ACE), an extensively used artificial sweetener, is the most worrisome example of ECs. The photolysis/photocatalysis, chlorination and/or permanganate oxidation of ACE produces transformation products (TPs) that are more persistent and toxic than precursors.

In(OTf)-Catalyzed Cascade Cyclization for Construction of Oxatricyclic Compounds.

A highly diastereoselective cascade cyclization reaction has been developed for establishing a series of oxatricyclic compounds using Chan's diene and simple keto alkynal substrates with only 1 mol % of In(OTf) as the catalyst in 82-92% yields. The potential utility of this synthetic strategy has been demonstrated in model studies for the construction the core structures of 1α,8α:4α,5α-diepoxy-4,5-dihydroosmitopsin and cortistatin A.

Formal Synthesis of (+)-Phomactin A.

A concise formal synthesis of (+)-phomactin A has been achieved. The key features of this synthetic strategy involve a one-pot Prins/Conia-ene cyclization protocol for the construction of the highly functionalized 1-oxadeclin core (AB ring) and a late-stage direct γ-hydroxylation of enone for the installation of the C ring.

Redox mediators and irradiation improve fenton degradation of acesulfame.

Widely recognized as a promising approach to degrading recalcitrant pollutants, Advanced Oxidation Processes (AOPs) have drawn much attention for their effectiveness and efficiency. Among all the AOPs, the Fenton system has been widely applied for oxidation and mineralization of micropollutants due to its ease of implementation and high catalytic efficiency. However, the necessity of preceding acidification, together with rapid consumption and slow regeneration of Fe(II) resulting in deterioration of reactivity, has reduced its competitiveness as a practical option for water treatment.

Joint Effects of Multiple UV Filters on Zebrafish Embryo Development.

The widespread use of UV filters has resulted in significant amounts of these chemicals appearing not only in the environment but also in organisms. This study first assessed the levels of nine UV filters in waters along the coast of Shenzhen, China, in tapwater, and in a nearby reservoir. UV filters were found to be high, in both winter and summer at most locations.

Impact of Lanthanide Nanomaterials on Photonic Devices and Smart Applications.

Half a century after its initial emergence, lanthanide photonics is facing a profound remodeling induced by the upsurge of nanomaterials. Lanthanide-doped nanomaterials hold promise for bioapplications and photonic devices because they ally the unmatched advantages of lanthanide photophysical properties with those arising from large surface-to-volume ratios and quantum confinement that are typical of nanoobjects. Cutting-edge technologies and devices have recently arisen from this association and are in turn promoting nanophotonic materials as essential tools for a deeper understanding of biological mechanisms and related medical diagnosis and therapy, and as crucial building blocks for next-generation photonic devices.

Fully Stretchable and Humidity-Resistant Quantum Dot Gas Sensors.

Stretchable gas sensors that accommodate the shape and motion characteristics of human body are indispensable to a wearable or attachable smart sensing system. However, these gas sensors usually have poor response and recovery kinetics when operated at room temperature, and especially suffer from humidity interference and mechanical robustness issues. Here, we demonstrate the first fully stretchable gas sensors which are operated at room temperature with enhanced stability against humidity.

Cyclometalated Iridium(III) Carbene Phosphors for Highly Efficient Blue Organic Light-Emitting Diodes.

Five deep blue carbene-based iridium(III) phosphors were synthesized and characterized. Interestingly, one of them can be fabricated into deep blue, sky blue and white organic light-emitting diodes (OLEDs) through changing the host materials and exciton blocking layers. These deep and sky blue devices exhibit Commission Internationale de l'Éclairage (CIE) coordinates of (0.

Chiroptically Active Metallic Nanohelices with Helical Anisotropy.

Manipulation of circular polarization states of light in the ultraviolet-visible-near infrared range, which cannot be operated using natural materials, is of fundamental interest derived from a wide range of chirality-associated optical, chemical and biological applications. To achieve this objective, chiral metamaterials made of metallic nanohelices (NHs) have been artificially designed and generated. The circular polarization manipulation is as a result of helical anisotropy and localized surface plasmon resonance of metallic NHs, and engineering helical structures and metallic composition gives rise to flexible tailoring of the circular polarization manipulation.

Ultraviolet-Visible Chiroptical Activity of Aluminum Nanostructures.

Ultraviolet (UV)-resonant metals (e.g., aluminum) typically have low melting point to cause a fabrication difficulty in helical sculpture to generate plasmons with chiroptical activity in the UV region.

Environmental behavior of 12 UV filters and photocatalytic profile of ethyl-4-aminobenzoate.

Ethyl-4-aminobenzoate (Et-PABA) is currently used as a substitute for 4-aminobenzoate (PABA) in sunscreens and anesthetic ointments. Despite its widespread use and hydrophilicity, Et-PABA has never been found in environmental waters. This study, probed the occurrence of Et-PABA in both seawater and drinking water sources in Hong Kong, and evaluated its transformation products (TPs) and environmental fate via cumulative potency and photocatalytic profile analyses.

Transformation of acesulfame in chlorination: Kinetics study, identification of byproducts, and toxicity assessment.

Acesulfame (ACE) is one of the most commonly used artificial sweeteners. Because it is not metabolized in the human gut, it reaches the aquatic environment unchanged. In the present study, the reactivity of ACE in free chlorine-containing water was investigated for the first time.

Development and application of a quantification method for water soluble organosulfates in atmospheric aerosols.

In recent years, organosulfates have been found as a significant component of secondary organic aerosols from both smog chamber experiments and field measurements. In this study, an indirect method was developed to estimate organosulfates in aerosol particles as a whole based on their sulfate functional group. A series of experiments were conducted to optimize and validate the method, and it was then applied to quantify organosulfates in the aerosol samples collected at three sampling characteristic sites in Shenzhen, with one close to a power plant (PP), one at a heavy traffic intersection (HTI), and one on the campus of Harbin Institute of Technology Shenzhen graduate school (HITSZ).

Photofunctionality in Porphyrin-Hybridized Bis(dipyrrinato)zinc(II) Complex Micro- and Nanosheets.

New bis(dipyrrinato)zinc(II) complex micro- and nanosheets containing zinc(II) porphyrin (N2) are synthesized. A liquid/liquid interface method between dipyrrin porphyrin ligand L2 and zinc acetate produces N2 with a large domain size. N2 can be layered quantitatively onto a flat substrate by a modified Langmuir-Schäfer method.