Inflammation assessment and therapeutic monitoring based on highly sensitive and multi-level electrochemical detection of PGE2.

Prostaglandin E2 (PGE2), an eicosane, regulates the physiological activity of inflammatory cells and represents a potential therapeutic target for facilitating tissue repair in vivo. In our work, an electrochemical immunosensor employing Ketjen black-Au nanoparticles (KB-Au) and poly tannic acid nanospheres conjugated with anti-PGE2 polyclonal antibody (PTAN-Ab) was designed to ultra-sensitively analyze PGE2 levels secreted by living cells and tissues. Antibody assembly strategies were explored to achieve signal amplification. Moreover, we studied the therapy effects of docosahexaenoic acid (DHA), arachidonic acid (AA), hyaluronic acid (HA), and small molecule 15-hydroxyprostaglandin dehydrogenase inhibitor (SW033291) on inflammation and evaluated the protective functions of HA and SW033291 in a murine model subjected to colitis induced by dextran sulfate sodium (DSS) using the developed sensor. The sensor exhibited a linear range of 10-5-106 fg/mL and a detection limit (LOD) of 10-5 fg/mL. Fetal bovine serum (FBS) samples were used to achieve high recovery of target analytes. This study not only presents an effective strategy for ultra-sensitively monitoring PGE2 but also provides valuable insights into assessing the degree of inflammation and the therapeutic effect of related drugs. Research on human health monitoring and regenerative medicine could greatly benefit from the findings.

SDC-DeepLabv3+: Lightweight and Precise Localization Algorithm for Safflower-Harvesting Robots.

Harvesting robots had difficulty extracting filament phenotypes for small, numerous filaments, heavy cross-obscuration, and similar phenotypic characteristics with organs. Robots experience difficulty in localizing under near-colored backgrounds and fuzzy contour features. It cannot accurately harvest filaments for robots. Therefore, a method for detecting and locating filament picking points based on an improved DeepLabv3+ algorithm is proposed in this study. A lightweight network structure, ShuffletNetV2, was used to replace the backbone network Xception of the traditional DeepLabv3+. Convolutional branches for 3 different sampling rates were added to extract information on the safflower features under the receptive field. Convolutional block attention was incorporated into feature extraction at the coding and decoding layers to solve the interference problem of the near-color background in the feature-fusion process. Then, using the region of interest of the safflower branch obtained by the improved DeepLabv3+, an algorithm for filament picking-point localization was designed based on barycenter projection. The tests demonstrated that this method was capable of accurately localizing the filament. The mean pixel accuracy and mean intersection over union of the improved DeepLabv3+ were 95.84% and 96.87%, respectively. The detection rate and weights file size required were superior to those of other algorithms. In the localization test, the depth-measurement distance between the depth camera and target safflower filament was 450 to 510 mm, which minimized the visual-localization error. The average localization and picking success rates were 92.50% and 90.83%, respectively. The results show that the proposed localization method offers a viable approach for accurate harvesting localization.

Mechanochemical remediation of contaminated soil: A review.

Mechanochemical techniques have been garnering growing attention in remediation of contaminated soil. This paper summarizes the performance, mechanism, influential factors, and environmental impacts of mechanochemical remediation (MCR) for persistent organic pollutants (POPs) contaminated soil and heavy metal(loid) s (HMs) contaminated soil. Firstly, in contrast to other technologies, MCR can achieve desirable treatment of POPs, HMs, and co-contaminated soil, especially with high-concentration pollutants. Secondly, POPs undergo mineralization via interaction with mechanically activated substances, where aromatic and aliphatic pollutants in soil may go through varied degradation routes; inorganic pollutants can be firmly combined with soil particles by fragmentation and agglomeration induced by mechanical power, during which additives may enhance the combination but their contact with anionic metal(loid)s may be partially suppressed. Thirdly, the effect of MCR primarily hinges on types of milling systems, the accumulation of mechanical energy, and the use of reagents, which is basically regulated through operating parameters: rotation speed, ball-to-powder ratio, reagent-to-soil ratio, milling time, and soil treatment capacity; minerals like clay, metal oxides, and sand in soil itself are feasible reagents for remediation, and alien additives play a crucial role in synergist and detoxification; additionally, various physicochemical properties of soil might influence the mechanochemical effect to varying degrees, yet the key influential performance and mechanism remain unclear and require further investigation. Concerning the assessment of soil after treatment, attention needs to be paid to soil properties, toxicity of POPs' intermediates and leaching HMs, and long-term appraisement, particularly with the introduction of aggressive additives into the system. Finally, proposals for current issues and forthcoming advancements in this domain are enumerated in items. This review provides valuable insight into mechanochemical approaches for performing more effective and eco-friendly remediation on contaminated soil.

RBF neural network dynamic sliding mode control based on lambert W function for piezoelectric stick-slip actuator.

This paper presents a novel approach for increasing the precision of high-precision positioning control experiments for a piezoelectric stick-slip actuator system. This is achieved through dynamic sliding mode control with a radial basis function neural network (RBFNN) based on the Lambert W function. The proposed control strategy is divided into two parts: scanning mode control and stepping mode control. For scanning control, a dynamic sliding mode controller was designed to solve the jitter problem in traditional sliding mode control. The introduction of the RBFNN avoids the effects of uncertainty terms and unknown disturbances in the model; reduces the controller gain, which must be adjusted; and improves the robustness of the system to disturbances. The stability of the dynamic sliding mode controller based on the RBFNN was verified through a Lyapunov analysis, and the Lambert W function was introduced to optimize the controller parameters responsible for the time lag in the closed-loop control system. This optimization improved the system's robustness against time delays, which can adversely affect its performance. Simulation and experimental results indicated that the proposed control strategy achieved a positioning control accuracy of <40 nm during the scanning phase and was robust in the presence of a load. In long-distance positioning control experiments, the control strategy achieved a control target of 40 µm while maintaining the positioning control accuracy and reducing the impact of time lag on the system.

Clinical significance of downregulated NISCH expression in skin cutaneous melanoma: Modulation of tumor cell invasion, migration, and EMT via PAK1 inhibition.

OBJECTIVE: This study aimed to investigate the expression and functional role of NISCH in skin cutaneous melanoma (SKCM), exploring its association with clinical characteristics and its potential impact on human skin melanoma cell behavior. METHODS: The research assessed differential NISCH expression in SKCM tissues using the GEPIA (Gene Expression Profiling Interactive Analysis) database and validated these findings through immunohistochemical staining of 45 clinical samples. To affirm NISCH expression at the cellular level, three human skin melanoma cell lines (RPMI-7951, A375, MEL-5), and the human normal skin cell line HEMa underwent quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and Western blotting. Transwell experiments evaluated the migration and invasion capabilities of RPMI-7951 and A375 cells post-transduction with NISCH or PAK1 lentiviral activation particles. Additionally, qRT-PCR analysis of epithelial-mesenchymal transition (EMT)-related gene expression (Vimentin, E-cadherin, N-cadherin) was conducted in A375 and RPMI-7951 cells. RESULTS: SKCM tissues exhibited significantly reduced NISCH expression compared to normal tissues. Immunohistochemical analysis revealed predominant nuclear localization of NISCH in melanoma cells, with reduced expression significantly correlating with sex, advanced stage, and lymph node metastasis. Melanoma cell lines displayed lower NISCH expression levels compared to normal skin cells. Functional experiments showcased that NISCH overexpression suppressed p-PAK1/PAK1, while PAK1 upregulation notably increased melanoma cell migration, invasion, and induced EMT. Remarkably, NISCH overexpression counteracted PAK1-induced effects on EMT, migration, and invasion in melanoma cells. CONCLUSION: NISCH may significantly influence the aggressive behavior of SKCM cells via the PAK1 pathway, making it a potential therapeutic target for managing melanoma metastasis.

Triaryl Carbenium Ion Pair Mediated Electrocatalytic Benzylic C-H Oxygenation in Air.

The selective oxidation of benzylic C-H bonds is a pivotal transformation in organic synthesis. Undoubtedly, achieving efficient and highly selective aerobic oxidation of methylarenes to benzaldehydes has been highly challenging due to the propensity of benzaldehyde to undergo overoxidation under typical aerobic conditions. Herein, we propose an innovative approach to address this issue by leveraging electrocatalytic processes, facilitated by ion-pair mediators [Ph3C]+[B(C6F5)4]-. By harnessing the power of electrochemistry, we successfully demonstrated the effectiveness of our strategy, which enables the selective oxidation of benzylic C-H bonds in benzylic molecules and toluene derivatives. Notably, our approach exhibited high efficiency, excellent selectivity, and compatibility with various functional groups, underscoring the broad applicability of our methodology.

Efficient roxarsone degradation by low-dose peroxymonosulfate with the activation of recycling iron-base composite material: Critical role of electron transfer.

Pollutant degradation via electron transfer based on advanced oxidation processes (AOPs) provides an economical and energy-efficient method for pollution control. In this study, an iron-rich waste, heating pad waste (HPW), was recycled as a raw material, and a strong magnetic catalyst (Fe-HPW) was synthesized at high temperature (900 °C). Results showed that in the constructed Fe-HPW/PMS system, effective roxarsone (ROX) degradation and TOC removal (72.54%) were achieved at a low-dose of oxidant (PMS, 0.05 mM) and catalyst (Fe-HPW, 0.05 g L-1), the ratio of PMS to ROX was only 2.5:1. In addition, the released inorganic arsenic was effectively removed from the solution. The analysis of the experimental results showed that ROX was effectively degraded by forming PMS/catalyst surface complexes (Fe-HPW-PMS*) to mediate electron transfer in the Fe-HPW/PMS system. Besides, this system performed effective ROX degradation over a wide pH range (pH=3-9) and showed high resistance to different water parameters. Overall, this study not only provides a new direction for the recycling application of HPW but also re-emphasizes the neglected nonradical pathway in advanced oxidation processes.

Inhibiting IL11RA to mitigate hepatic metastasis in skin cutaneous melanoma: Comprehensive insights from in vitro and in vivo investigations.

OBJECTIVE: This study aimed to investigate the role of Interleukin-11 receptor alpha (IL11RA) in skin cutaneous melanoma (SKCM) metastasis to the liver. METHODS: Human SKCM cell lines (A375, A375-MA2, SK-MEL-28, RPMI-7951) and primary dermal fibroblasts (HDFa) were utilized to assess IL11RA expression. IL11RA siRNA was transfected into RPMI-7951 and A375-MA2 cells for Wound healing and Transwell invasion assays. Il11ra knockout (KO) mice and wild-type (WT) mice were injected with B16-F10 cells into the spleen to evaluate hepatic melanoma metastasis. Correlation between IL11RA and MMP family genes was explored using online databases, including LinkedOmics, TIMER (Tumor Immune Estimation Resource), and GEPIA (Gene Expression Profiling Interactive Analysis). RT-qPCR and Western blotting were performed for expression analysis of Mmp2 and Mmp9 in liver tissues of mice. The impact of IL11RA on the STAT3 pathway was investigated in vitro and in vivo. RESULTS: Elevated expression of IL11RA was observed in SKCM cell lines compared to normal cells. IL11RA downregulation significantly inhibited migratory and invasive capabilities of A375-MA2 and RPMI-7951 in vitro. Il11ra gene knockout in mice demonstrated a substantial reduction in hepatic melanoma metastasis. Correlation analyses revealed associations between IL11RA and MMP2/MMP8. Il11ra gene knockout significantly decreased Mmp2 expression while increasing Mmp8 in liver tissues. IL11RA correlated positively with STAT3, and its inhibition led to a suppressed STAT3 pathway in SKCM cells and mouse liver tissue. CONCLUSION: IL11RA plays a crucial role in SKCM metastasis, affecting migratory and invasive abilities. Targeting IL11RA may offer a promising avenue for therapeutic interventions in cutaneous melanoma progression.

Silicon-Containing Thiol-Specific Bioconjugating Reagent.

A new bioconjugation reagent containing silicon has been developed for the selective reaction with thiols. The inclusion of silicon significantly improves chemoselectivity and suppresses retro processes, thereby exceeding the capabilities of traditional reagents. The method is versatile and compatible with a broad range of thiols and unsaturated carbonyl compounds and yields moderate to high results. These reactions can be conducted under biocompatible conditions, thereby making them suitable for protein bioconjugation. The resulting conjugates display good stability in the presence of various biomolecules, which suggests their potential application for the synthesis of antibody-drug conjugates. Furthermore, the presence of a silicon moiety within the conjugated products opens up new avenues for drug release and bridging inorganics with other disciplines. This new class of silicon-containing thiol-specific bioconjugation reagents has significant implications for researchers working in bioanalytical science and medicinal chemistry and leads to innovative opportunities for advancing the field of bioconjugation research and medicinal chemistry.

Mechanochemical degradation performance of lindane in different types of soils: The effects of soil properties and elemental components.

Although mechanochemical remediation of organic-contaminated soil has received substantial attention in recent years, the effects of soil properties on soil remediation performance are not clear. In this work, the properties and elemental components of 16 soils were tested, and the mechanochemical degradation performance of lindane in these soils was investigated through experiments. Most importantly, the relationships between soil variables and the mechanochemical degradation rates of lindane in the additive-free and CaO systems were elucidated. The results showed that the mechanochemical degradation efficiencies of lindane in the 16 soils were significantly different without additives, with a range of 31.0 %-97.2 % after 4 h. The mechanochemical degradation rates of lindane in the 16 soils varied from 0.7 h-1 to 15 h-1 after the addition of 9 % CaO. Correlation analysis, redundancy analysis and the partial least squares path modeling results clearly showed that the main factors affecting the reaction rate (k1) without additives were organic matter (-) > clay (+) > bound water (-) > Si (+). After the addition of 9 % CaO, the order in which the main factors affected the reaction rate (k2) was organic matter (-) > bound water (-) > Ti/Fe/Al (-) > pH (+) > clay (+). The established and corrected multiple nonlinear regression equations can be used to accurately predict the mechanochemical degradation performance of hexachlorocyclohexanes in actual soils with and without additives.

Linkage conversions in single-crystalline covalent organic frameworks.

Single-crystal X-ray diffraction is a powerful characterization technique that enables the determination of atomic arrangements in crystalline materials. Growing or retaining large single crystals amenable to it has, however, remained challenging with covalent organic frameworks (COFs), especially suffering from post-synthetic modifications. Here we show the synthesis of a flexible COF with interpenetrated qtz topology by polymerization of tetra(phenyl)bimesityl-based tetraaldehyde and tetraamine building blocks. The material is shown to be flexible through its large, anisotropic positive thermal expansion along the c axis (αc = +491 × 10-6 K-1), as well as through a structural transformation on the removal of solvent molecules from its pores. The as-synthesized and desolvated materials undergo single-crystal-to-single-crystal transformation by reduction and oxidation of its imine linkages to amine and amide ones, respectively. These redox-induced linkage conversions endow the resulting COFs with improved stability towards strong acid; loading of phosphoric acid leads to anhydrous proton conductivity up to ca. 6.0 × 10-2 S cm-1.

Dual-Proton Conductor for Fuel Cells with Flexible Operational Temperature.

The properties of proton conductors determine the operating temperature range of fuel cells. Typically, phosphoric acid (PA) proton conductors exhibit excellent proton conductivity owing to their high proton dissociation and self-diffusion abilities. However, at low temperatures or high current densities, water-induced PA loss causes rapid degradation of cell performance. Maintaining efficient and stable proton conductivity within a flexible temperature range can significantly reduce the start-up temperature of PA-doped proton exchange membrane fuel cells. In this study, a dual-proton conductor composed of an organic phosphonic acid (ethylenediamine tetramethylene phosphonic acid, EDTMPA) and an inorganic PA is developed for proton exchange membranes. The proposed dual-proton conductor can operate within a flexible temperature range of 80-160 °C, benefiting from the strong interaction between EDTMPA and PA, and the enhanced proton dissociation. Fuel cells with the EDTMPA-PA dual-proton conductor showed excellent cell stability at 80 °C. In particular, under the high current density of 1.5 A cm-2 at 160 °C, the voltage decay rate of the fuel cell with the dual-proton conductor is one-thousandth of that of the fuel cell with PA-only proton conductor, indicating excellent stability.

Clinical study of modified photodynamic therapy combined with Taohong Siwu Decoction in treating hypertrophic scar after severe burn.

OBJECTIVE: The aim of this study was to study the curative effect and the relative mechanism of modified photodynamic therapy combined with Taohong Siwu Decoction in the treatment of hyperplastic scar after severe burn, in order to provide a stable, safe and satisfactory scheme for scar repair. METHODS: Forty cases with hyperplastic scars after severe burns admitted to the plastic surgery department from May 2021 to May 2022 were divided into a control group and an observation group by means of the random number table method. The control group was treated with ordinary laser therapy combined with Taohong Siwu Decoction, while the observation group was treated with modified photodynamic therapy combined with Taohong Siwu Decoction. The Vancouver Scar Scale (VSS) was assessed in both groups, and the clinical effectiveness of both groups was compared. HE-staining was performed on the scar tissue of the same patient before and after treatment to observe the changes in the arrangement of fibroblasts. The Vascular Endothelial Growth Factor (VEGF), ß-Transforming Growth Factor (TGF-ß), and Platelet-Derived Growth Factor (PDGF) in the tissue samples of both groups were detected by quantitative real-time PCR. The patients were followed up for 6 months, and their satisfaction, side effects, and scar recurrence were observed. RESULTS: Compared with the control group, the VSS score in the observation group was lower (p < 0.05). The therapeutic effect of the observation group was superior to the control group after 3 months (p < 0.05). After 3-months of therapy, the arrangement of fibroblasts in the scar became looser in two groups, and the observation group was more looser. The VEGF, TGF-ß and PDGF levels in tissue samples of the observation group were lower than those in the control group after 3 months of treatment (p < 0.05). The satisfaction of the observation group was higher than that of the control group (p < 0.05). The adverse reactions between the two groups showed no difference (p > 0.05), while the recurrence rate was lower in the observation group (p < 0.05). CONCLUSION: Modified photodynamic therapy combined with Taohong Siwu Decoction shows remarkable efficacy in patients with hyperplastic scars after severe burns. It can improve the color, thickness, vascular distribution, and softness of the scar, and reduce the level of cytokines related to tissue repair. At the same time, it can improve patients' satisfaction with the aesthetic appearance and reduce the recurrence rate, providing a new comprehensive therapy that is safer and more effective, simple and quick, and easy to promote in the clinic.

Thiol-Specific Silicon-Containing Conjugating Reagent: ß-Silyl Alkynyl Carbonyl Compounds.

Site-specific modification of thiol-containing biomolecules has been recognized as a versatile and powerful strategy for probing our biological systems and discovering novel therapeutics. The addition of lipophilic silicon moiety opens up new avenues for multi-disciplinary research with broad applications in both the medicinal and material sciences. However, adhering to the strict biocompatibility requirements, and achieving the introduction of labile silicon handle and high chemo-selectivity have been formidable. In this paper, we report silicon-based conjugating reagents including ß-trialkylsilyl and silyl ether-tethered alkynones that selectively react with thiols under physiological conditions. The pH-neutral, metal-free and additive-free reaction yields stable products with broad substrate compatibility and full retention of silicon handles in most cases. Besides simple aliphatic and aromatic thiols, this approach is applicable in the labeling of thiols present in proteins, sugars and payloads, thereby expanding the toolbox of thiol conjugation.

Model-Free Adaptive Positioning Control of the Bidirectional Stick-Slip Piezoelectric Actuator with Coupled Asymmetric Flexure-Hinge Mechanisms.

A model-free adaptive positioning control strategy for piezoelectric stick-slip actuators (PSSAs) with uncertain disturbance is proposed. The designed controller consists of a data-driven self-learning feedforward controller and a model-free adaptive feedback controller with a radial basis function neural network (RBFNN)-based observer. Unlike the traditional model-based control methods, the model-free adaptive control (MFAC) strategy avoids the complicated modeling process. First, the nonlinear system of the PSSA is dynamically linearized into a data model. Then, the model-free adaptive feedback controller based on a data model is designed to avoid the complicated modeling process and enhance the robustness of the control system. Simultaneously, the data-driven self-learning feedforward controller is improved to realize the high-precision control performance. Additionally, the convergence of the tracking error and the boundedness of the control output signal are proved. Finally, the experimentally obtained results illustrate the advantages and effectiveness of the developed control methodology on the bidirectional stick-slip piezoelectric actuator with coupled asymmetric flexure-hinge mechanisms. The positioning error through the proposed controller reaches 30 nm under the low-frequency condition and 200 nm under the high-frequency condition when the target position is set to 100 µm. In addition, the target position can be accurately tracked in less than 0.5 s in the presence of a 100 Hz frequency.

Injectable hydrogels derived from marine polysaccharides as cell carriers for large corneal epithelial defects.

Injectable hydrogels have been employed for sutureless repair of corneal epithelial defects, which can perfectly fit the defect sites and minimize the associated discomfort. However, numerous hydrogels are ineffective in treating large corneal epithelial defects and still suffer from poor biocompatibility or weak applicability when used as cell carriers. Herein, hydroxypropyl chitin/carboxymethyl chitosan (HPCT/CMCS) temperature-sensitive hydrogels are fabricated, and their physicochemical properties and suitability for corneal epithelial repair are investigated. The results demonstrate that HPCT/CMCS hydrogels have excellent temperature sensitivity between 20 and 25 °C and a transparency of over 80 %. Besides, HPCT/CMCS hydrogels can promote cell proliferation and facilitate cell migration of primary rabbit corneal epithelial cells (CEpCs). A rabbit large corneal epithelial defect model (6 mm) is established, and CEpCs are transplanted into defect sites by HPCT/CMCS hydrogels. The results suggest that HPCT/CMCS/CEpCs significantly enhance the repair of large corneal epithelial defects with a healing rate of 99.6 % on day 8, while reducing inflammatory responses and scarring formation. Furthermore, HPCT/CMCS/CEpCs can contribute to the reconstruction of damaged tissues and the recovery of functional capacities. Overall, HPCT/CMCS hydrogels may be a feasible corneal cell carrier material and can provide an alternative approach to large corneal epithelial defects.

Peroxymonosulfate assisted mechanochemical remediation of high concentration DDTs contaminated soil.

DDTs (DDT and its metabolites) contaminated sites urgently need to be treated efficiently and greenly. In this study, a horizontal planetary mechanochemical method with co-milling additives was developed aiming at efficiently degrading high-concentration DDTs in historical contaminated soil (∼7500 mg/kg). Peroxymonosulfate (PMS) was firstly used to the mechanochemical degradation of DDTs in historical contaminated soil, with a degradation efficiency of over 95% after 1 h of milling under the optimal milling conditions (CR = 30:1, r = 500 rpm, R = 1:4). Mechanism study indicated that DDTs in soil were partially dechlorinated and mineralized. The main products formed might be chlorinated aliphatic hydrocarbons, which need further treatment by ball milling or other methods. Under the action of mechanical energy, PMS could oxidize DDTs in soil through non-radical way rather than common radical way. Then, a comprehensive assessment of this remediation method was conducted by analyzing the changes in soil properties and acute biotoxicity after ball milling. Although PMS had a great performance on the degradation of DDTs, especially p, p'-DDE, it would cause the acidification and salinization of soil. Therefore, further pH adjustment and desalination treatment were suggested to reduce the negative impacts. This work successfully presents a practical approach to mechanochemical remediation of DDTs contaminated sites.

Integral back-stepping active disturbance rejection control for piezoelectric stick-slip drive nanopositioning stage.

Piezoelectric stick-slip driven nanopositioning stage (PSSNS) with nanometer resolution has been widely used in the field of micro-operation. However, it is difficult to achieve nanopositioning over large travel, and its positioning accuracy is affected by the hysteresis characteristics of the piezoelectric elements, external uncertain disturbances, and other nonlinear factors. To overcome the above-mentioned problems, a composite control strategy combining stepping mode and scanning mode is proposed in this paper, and an integral back-stepping linear active disturbance rejection control (IB-LADRC) strategy is proposed in the scanning mode control phase. First, the transfer function model of the system in the micromotion part was established, and then the unmodeled part of the system and the external disturbance were treated as the total disturbance and extended to a new system state variable. Second, a linear extended state observer was used as the core of the active disturbance rejection technique to estimate displacement, velocity, and total disturbance in real time. In addition, by introducing virtual control variables, a new control law was designed to replace the original linear control law and improve the positioning accuracy and robustness of the system. Furthermore, the effectiveness of the IB-LADRC algorithm was verified by simulation comparison experiments and experimentally validated on a PSSNS. Finally, experimental results show that the IB-LADRC is a practical solution for a controller capable of handling disturbances during the positioning of a PSSNS with a positioning accuracy of less than 20 nm, which essentially remains constant under load.

Mechanochemical remediation of lindane-contaminated soils assisted by CaO: Performance, mechanism and overall assessment.

Soil contamination caused by persistent organic pollutants (POPs) has been a worldwide concern for decades. With lindane-contaminated soil as the target, a mechanochemical method assisted by CaO was comprehensively evaluated in terms of its remediation performance, degradation mechanism and overall assessment. The mechanochemical degradation performance of lindane in cinnamon soil or kaolin was determined under different additives, lindane concentrations and milling conditions. 2,2-Diphenyl-1-(2,4,6-trinitrophenyl) hydrazinyl free radical (DPPH•) and electron spin resonance (ESR) tests evidenced that the degradation of lindane in soil was caused mainly by the mechanical activation of CaO to produce free electrons (e-) and the alkalinity of the generated Ca(OH)2. Dehydrochlorination or dechlorination by elimination, alkaline hydrolysis, hydrogenolysis and the subsequent carbonization were the main degradation pathways of lindane in soil. The main final products included monochlorobenzene, carbon substances and methane. The mechanochemical method with CaO was proved to also efficiently degrade lindane in three other soils and other hexachlorocyclohexane isomers and POPs in soil. The soil properties and soil toxicity after remediation were assessed. This work presents a relatively clear discussion of various aspects of the mechanochemical remediation of lindane-contaminated soil assisted by CaO.

A Rare Earth Metal Catalyzed Aerobic Dehydrogenation of N-Heterocycles.

Rare earth metals exhibit high catalytic activity and selectivity in various organic reactions due to their unique electronic properties. Among them, praseodymium has shown high catalytic activity under mild reaction conditions compared with transitional metals. Here, we report a strategy of Pr-catalyzed aerobic dehydrogenative aromatization of saturated N-heterocycles to produce 7 classes of products with a broad substrate scope.