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Layered double hydroxide (LDH) material with abundant OH was successfully prepared by co-precipitation method, and a water purification system of Ni2Fe0.25Al0.75-LDH activated peroxymonosulfate (PMS) was constructed to rapidly degrade sulfamethoxazole (SMX) pollutants. The optimal conditions for the degradation of SMX in the system were as follows: 0.30 g/L Ni2Fe0.25Al0.75-LDH, 0.30 mM PMS, pH = 7 and 90 % SMX was removed in 10 min and almost completely in 40 min, which was consistent with the predicted results of response surface methodology (RSM) analysis. The abundant OH in Ni2Fe0.25Al0.75-LDH could form M(O)OSO3 complexes with PMS, accelerating the generation of reactive oxygen species (ROS) and promoting the removal of SMX. Quenching experiments and electron paramagnetic resonance (EPR) spectra showed that SO4-, OH, O2- and 1O2 also existed in the system. The surface-bound SO4- and O2- contributed greatly to the removal of SMX and the electron transfer between metals was also conducive to the production of active substances. The possible degradation pathways and intermediates of SMX were proposed. The toxicity assessment software tool (T.E.S.T) and total organic carbon (TOC) results indicated that the Ni2Fe0.25Al0.75-LDH/PMS system could reduce the overall environmental risk of SMX to some extent. This study provided a new strategy for the practical application of heterogeneous catalysts in sewage treatment.

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Drug delivery advances rely on using nano- and microsized carriers to transfer therapeutic molecules, although challenges persist in increasing the availability of new and even approved pharmaceutical products. Particle shape, a critical determinant in how these carriers distribute within the body after administration, raises opportunities of using, for instance, micrometer-sized nonspherical particles for vascular targeting and thereby creating new prospects for precise drug delivery to specific targeted areas. The versatility of polycrystalline silicon microfabrication allows for significant variation in the size and shape of microchips, and so, in the current work, photolithography was employed to create differently shaped polysilicon microchips, including cuboids, cubes, bars, and cylinders, to explore the influence of particle shape on cellular interactions. These microchips with different shapes and lateral dimensions, accounting for surface areas in the range of ca. 15 to 120 µm2 and corresponding total volumes of 0.4 to 27 µm3, serve as ideal models for investigating their interactions with macrophages with diameters of ca. 20 µm. Side-scattering imaging flow cytometry was employed for studying the interaction of label-free prepared microchips with RAW 264.7 macrophages. Using a dose of 3 microchips per cell, results show that cuboids exhibit the highest cellular association (ca. 25%) and uptake (ca. 20%), suggesting their potential as efficient carriers for targeted drug delivery to macrophages. Conversely, similarly sized cylinders and bar-shaped microchips exhibit lower uptakes of about 8% and about 6%, respectively, indicating potential benefits in evading macrophage recognition. On average, 1-1.5 microchips were internalized, and ca. 1 microchip was surface-bound per cell, with cuboids showing the higher values overall. Macrophages respond to microchips by increasing their metabolic activity and releasing low levels of intracellular enzymes, indicating reduced toxicity. Interestingly, increasing the particle dose enhances macrophage metabolic activity without significantly affecting enzyme release.

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Nitrogen-doped carbon materials are effective catalysts for peroxymonosulfate (PMS) activation to eliminate organic contaminants. In this research, the activity of nitrogen-doped carbon materials was significantly improved by optimizing the carbon source, and the reusability of the catalyst is used to select the best catalyst instead of depending on the performance in the first use, for avoiding the "short-life" catalyst with great initial activity. Fixing ferric nitrate nonahydrate and melamine as the metal and nitrogen sources, four catalysts were prepared using glucose, glucosamine hydrochloride, dopamine, and trimesic acid as the carbon sources, respectively. Based on the performance in PMS activation for sulfamethoxazole (SMX) removal, in the first use, the activity was Fe-DA-CN (carbon source: dopamine) > Fe-BTC-CN (carbon source: trimesic acid) > Fe-GLU-CN (carbon source: glucosamine) > Fe-DGLU-CN (carbon source: glucose). With no washing for the second time use, the activity was Fe-BTC-CN (0.135 min-1) â‰« Fe-DA-CN (0.037 min-1) > Fe-GLU-CN (0.032 min-1) > Fe-DGLU-CN (0.017 min-1). The large specific surface area, superior graphitization, and high CO/C-N group content endow Fe-BTC-CN with high ability in PMS activity. Surface-bound radicals are responsible for SMX elimination, and most of the SMX degradation intermediates have lower ecotoxicity than SMX.

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The locus-specific methylation of three genes (GSTP1, RNF219, and KIAA1539, also known as FAM214B) in the total pool of blood cell-free DNA, including cell-free DNA from plasma and cell-surface-bound DNA, of patients with prostate cancer and healthy donors was studied on the MiSeq platform. Our study found a higher methylation index of loci for total cell-free DNA compared with cell-free DNA. For total cell-free DNA, the methylation of GSTP1 in each of the 11 positions provided a complete separation of cancer patients from healthy donors, whereas for cell-free DNA, there were no positions in the three genes allowing for such separation. Among the prostate cancer patients, the minimum proportion of GSTP1 genes methylated in any of the 17 positions was 12.1% of the total circulated DNA fragments, and the minimum proportion of GSTP1 genes methylated in any of the 11 diagnostically specific positions was 8.4%. Total cell-free DNA was shown to be more convenient and informative as a source of methylated DNA molecules circulating in the blood than cell-free DNA.

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First time, this study synthesized a magnetic-modified sludge biochar (MSBC) as an activator of peroxymonosulfate (PMS) to eliminate sulfamethoxazole (SMX). The removal efficiency of SMX reached 96.1% at t = 60 min by PMS/MSBC system. The larger surface area and magnetic Fe3O4 of MSBC surface enhanced its activation performance for PMS. The PMS decomposition, premixing and reactive oxygen species (ROS) identification experiments combined with Raman spectra analysis demonstrated that the degradation process was dominated by surface-bound radicals. The transformed products (TPs) of SMX and the main degradation pathways were identified and proposed. The ecotoxicity of all TPs was lower than that of SMX. The magnetic performance was beneficial for its reuse and the removal efficiency of SMX was 83.3% even after five reuse cycles. Solution pH, HCO3- and CO32- were the critical environmental factors affecting the degradation process. MSBC exhibited environmental safety for its low heavy metal leaching. PMS/MSBC system also performed excellent removal performance for SMX in real waters including drinking water (88.1%), lake water (84.3%), Yangtze River water (83.0%) and sewage effluent (70.2%). This study developed an efficient PMS activator for SMX degradation in various waters and provided a workable way to reuse and recycle municipal sludge.

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A one-step hydrothermal method for preparation of copper oxides with different valences using ascorbic acid as a reducing reagent was developed for environmental remediation. The results suggested that the notable degradation performance of CuO0 may be attributable to the abundant active sites, such as Cu or Cu-O, and was not significantly related to the Cu valence state. In contrast to direct degradation of pollutants by traditional superoxide radicals (O2•-), O2•- played an important role in the reduction of high-valence Cu ions (Cu(III)). In addition, a series of radical quenching, electron paramagnetic resonance (EPR), and electrochemical experiments validated the existence of direct electron transfer between methylene blue (MB) and PMS mediated by CuO0 and surface-bound radicals. The results suggested that the CuO0/PMS system may be less susceptible to diverse ions and natural organic matter other than dihydrogen phosphate anions. The mechanism of MB degradation under alkaline conditions was different from that under acidic conditions in that it was not reliant on radicals or charge transfer but direct oxidation by PMS. This study provides new insights into the heterogeneous processes involved in PMS activation by the copper oxides. Furthermore, this paper devotes to providing theoretical basis on pollutant removal via PMS activated by copper oxides and developing low-cost and high-efficiency catalysts.

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Developing highly efficient, stable, recyclable, and application value heterogeneous catalysts in advanced oxidation processes has essential application value in the degradation of refractory pollutants. In this paper, the CoNi alloy anchored onto N-doped porous carbon (CoNi-600@NC) catalyst was prepared using bimetallic doped metal-organic frameworks as precursors. The magnetic CoNi-600@NC can activate peroxymonosulfate (PMS) to degrade sulfamethoxazole (SMX). Therefore, SMX can be removed 100% within 25 min. CoNi-600@NC/PMS has a broad pH (3-9) application range, good applicability, and repeatability. Radical quenching, quantitative and electrochemical experiments proved that the degradation of SMX was dominated by free radical (Superoxide anions) and non-free radical pathways (surface-bound radicals). Mechanistic analysis showed that the interaction between Co-Nx/pyridine N-sites and graphitized carbon with PMS induced the formation of surface-bound active species. Moreover, CoNi nanoparticles promoted the redox cycle of metals. The synergistic catalytic mechanisms between the CoNi alloy and the abundant functional groups gave CoNi-600@NC excellent catalytic properties and applicability. Using density functional theory predicted the reaction sites of SMX and proposed four degradation pathways. The toxicity of intermediates was comprehensively evaluated. In addition, a CoNi-600@NC continuous flow reactor was constructed with a daily treatment capacity of 45 L and 100% SMX removal. This study expands the application of persulfate advanced oxidation technology by synthesizing recyclable magnetic catalysts and provides new synergistic degradation mechanisms for removing refractory organics.

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In electrochemical advanced oxidation processes (EAOPs), the rate-limiting step is the mass transfer of pollutants to the electrodes due to the limited active surface areas. To this end, we established a three-dimensional (3D) EAOP system by coupling conventional graphite electrodes with dispersed carbon nanotubes (CNTs). The electrodes (particularly the anode) induced electric field spontaneously polarized CNTs into dispersed reactive particle electrodes (CNT-PEs) in the solution, which remarkably promoted electrochemical activation of peroxydisulfate (PDS) to generate surface CNT-PDS* complexes and surface-bound radicals (SBRs). Based on the excited potential (ECNT-PEs) at different positions in the 3D electric field, CNT-PEs were activated into three states. (i) ECNT-PEs < Eorganic, CNT-PEs are chemically inert toward DCP oxidation; (ii) Eorganic < ECNT-PEs < Ewater, CNT-PEs will oxidize DCP via an electron-transfer process (ETP); (iii) ECNT-PEs > Ewater, both CNT-PDS* complexes and the anode will oxidize water to produce SBRs. Thus, DCP could be oxidized by CNT-PDS* complexes via ETP to form polychlorophenols on the CNT surface, causing rapid deactivation of the micro-electrodes. In contrast, SBRs attack DCP directly into chloride ions and hydroxylated products, maintaining the surface cleanliness and activity of CNT-PEs for long-term operations.

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The plasma membrane (PM) of cells is a dynamic structure whose morphology and composition is in constant flux. PM morphologic changes are particularly relevant for the assembly and disassembly of signaling platforms involving surface-bound signaling proteins, as well as for many other mechanochemical processes that occur at the PM surface. Surface-bound membrane proteins (SBMP) require efficient association with the PM for their function, which is often achieved by the coordinated interactions of intrinsically disordered regions (IDRs) and globular domains with membrane lipids. This review focuses on the role of IDR-containing SBMPs in remodeling the composition and curvature of the PM. The ability of IDR-bearing SBMPs to remodel the Gaussian and mean curvature energies of the PM is intimately linked to their ability to sort subsets of phospholipids into nanoclusters. We therefore discuss how IDRs of many SBMPs encode lipid-binding specificity or facilitate cluster formation, both of which increase their membrane remodeling capacity, and how SBMP oligomers alter membrane shape by monolayer surface area expansion and molecular crowding.

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In this study, activation of peroxymonosulfate (PMS) by amorphous FeOOH to degrade sulfamethoxazole (SMX) was investigated. The amorphous FeOOH showed a better performance in the decomposition of PMS and the degradation of SMX than the crystallized α-FeOOH and ß-FeOOH. The quenching experiments and EPR measurements suggested that the mechanism of PMS activation by amorphous FeOOH was mainly the surface-bound radicals (●OH and SO4●-). Basically, the surface-bound ●OH radicals were the dominate reactive oxide species in this system, which were mainly generated via the decomposition of amorphous FeOOH-PMS complexes. The degradation of SMX was significantly inhibited with the presence of H2PO4-, and this adverse impact was negligibly affected by the increase of H2PO4- concentration, implying that the inhibition of SMX degradation was caused by competitive adsorption. Consequently, the Fe-OH bonds on the amorphous FeOOH were proposed as the reactive sites for forming amorphous FeOOH-PMS complexes. Besides, the amorphous FeOOH showed a better performance in the degradation of SMX in the acid conditions than that in the base conditions due to the surface charge of amorphous FeOOH. More importantly, the reduction efficiency of Fe(III) was significantly enhanced due to the excellent conductivity of amorphous FeOOH.

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Aberrantly methylated circulating DNA (cirDNA) has proven to be a good cancer marker, but its detection is limited by low concentrations, fragmentation, and insufficiency. Since the methylated cirDNA was shown to be more stable in circulation than the unmethylated one and was shown to bind with the blood cell surface, we studied the concentration, representation, and fragmentation of tumor-derived methylated DNA in cell-free and cell-surface-associated DNA. We found that long DNA fragments (more than 10 kb) are mainly associated with the surface of blood cells. However, in plasma short DNA fragments (100-1000 bp) were also found along with long DNA fragments. Isolation of short fragments after separation of cirDNA in 6% PAGE followed by quantitative PCR (L1 element) has shown that short DNA fragments in healthy females represent 22% versus 0.5-4.4% in breast cancer patients. The methylated form of the RARß2 gene was detected only in long DNA fragments by Real-time TaqMan PCR of bisulfite-converted DNA. The methylation index of cirDNA from healthy women was estimated at 0%, 9%, and 7% in plasma, PBS-EDTA, and trypsin eluates from the surface of blood cells, respectively. The methylation index of breast cancer patients' DNA was found to be 33%, 15%, and 61% in the same fractions confirming the overrepresentation of methylated DNA in csbDNA.

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Circulating DNA has already proven itself as a valuable tool in translational medicine. However, one of the overlooked areas of circulating DNA research is its association with different proteins, despite considerable evidence that this association might impact DNA's fate in circulation and its biological role. In this review, we attempt to shed light on current ideas about circulating DNA origins and forms of circulation, known biological effects, and the clinical potential of circulating tumor deoxyribonucleoprotein complexes.

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Natural organic matter (NOM) and iron oxides have been proved to be crucial factors controlling the behaviors of nanoparticles in heterogenous environment. Here, we conducted experimental and modeling study on the transport of titanium dioxide nanoparticles (TiO2 NPs) in iron oxide-coated quartz in the presence of NOM under acidic conditions. Results showed the antagonistic effects of iron oxides and NOM on TiO2 NPs mobility. The inhibition of iron oxides coated on quartz was crystal form-dependent other than quantity-dependent. Amorphous ferric oxyhydroxide with higher specific surface area brought more positive charge and favorable deposition sites onto quartz, and induced more retention of nanoparticles than two crystalline iron oxides, goethite and hematite. Dissolved organic matter (DOM) facilitated TiO2 NPs transport in iron oxide-coated quartz. In comparation with the limited enhancing effects of DOM, the NOM coatings on media surface partially or largely offset the inhibition of goethite on nanoparticles mobility through direct occupation of attachment sites and sites screening due to the steric repulsion of the macromolecules. Owing to the higher steric hindrance, humic acid, both in dissolved and media surface-bound states, exerted stronger facilitating effects on TiO2 NPs mobility relative to fulvic acid.

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M-BTCs (M = Fe, Co and Mn)/melamine were used to prepare N-doped carbon materials, and their performances as activator of peroxymonosulfate (PMS) for sulfamethazine (SMZ) removal were compared. M-BTC type metal-organic frameworks (MOFs) were synthesized under room temperature, with their yield about 7.5 times of ZIF-67 which is the most used MOFs to prepare N-doped carbon materials as the catalyst of persulfate-based advanced oxidation processes. Co-BTC/melamine derived N-doped carbon materials (Co-BTC/5MNC) performed the best, even better than that of ZIF-67 derived N-doped carbon materials. Initial pH (3-9), 0-10 mM inorganic anions (Cl-, NO3-, HCO3- and H2PO42-) and humic acid (5 and 10 mg/L) had no obvious inhibition on SMZ removal with Co-BTC/5MNC as catalyst. The results of both X-ray photoelectron spectroscopy and density functional theory (DFT) calculations indicated that N-coordinated cobalt single atom site (Co-Nx) was the possible active site of Co-BTC/5MNC. Importantly, surface-bound SO4•- was identified as the dominant reactive oxygen species for SMZ removal. The SO4•- generated through the charge transfer between PMS and catalyst, and was tightly adsorbed on Co-Nx site.

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Organoarsenic contaminants existing in water body threat human health and ecological environment due to insufficient bifunctional treatment technologies for organoarsenic degradation and inorganic arsenic immobilization. In order to safely and efficiently treat organoarsenic contaminants discharged into the aquatic environment, Co-Mn-Fe layered double hydroxide (CoMnFe-LDH) and Co-Mn-Fe layered double oxide (CoMnFe-LDO) were fabricated and employed as peroxymonosulfate (PMS) activator for organoarsenic degradation and inorganic arsenic immobilization, and p-arsanilic acid (p-ASA) was selected as target pollutant. Results demonstrated that the satisfactory removal of p-ASA (100.0%) in both CoMnFe-LDH/PMS and CoMnFe-LDO/PMS systems was obtained within 30 min, and substantial inorganic arsenic adsorption could be achieved (below 0.5 mg/L) in two systems with converting major inorganic arsenic species to arsenate. As XPS, ESR and quenching experiment revealed, the existence and generation of surface-bound radicals in two systems were identified. Based on density functional theory calculation and XPS analysis, the catalytic mechanism of CoMnFe-LDO/PMS system that PMS could be activated via direct electron transfer from adsorbed p-ASA was clarified, which differed from PMS activation via coupling with surface hydroxyl groups in CoMnFe-LDH/PMS system. Catalytic performance assessment under various critical operation parameters indicated that CoMnFe-LDH presented more stable ability of p-ASA removal in a wide pH range and complex aquatic environment. The recycle experiment demonstrated the excellent stability and reusability of CoMnFe-LDH(LDO). Besides, seven degradation products of p-ASA in CoMnFe-LDH/PMS system including phenolic compounds, azophenylarsonic acid, nitrobenzene and benzoquinne were identified by UV-Vis spectra and LC-TOF-MS analysis, and the corresponding degradation pathway was proposed. In summary, compared to CoMnFe-LDO/PMS, CoMnFe-LDH/PMS holds great promise for the development of an oxidation-adsorption process for efficient control of organoarsenic pollutant.

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The high affinity and/or selectivity of oligonucleotide-mediated binding offers a myriad of therapeutical and analytical applications, whose rational design implies an accurate knowledge of the involved molecular mechanisms, concurring equilibrium processes and key affinity parameters. Oligonucleotide-functionalized gold surfaces or nanostructures are regularly employed analytical platforms for the development of label-free optical or electrochemical biosensors, and recently, novel detection platform designs have been increasingly considering the synergistic effect of polyvalent binding, involving the simultaneous interaction of two or several oligonucleotide strands. Considering the general lack of studies involving ternary single-stranded DNA (ssDNA) interactions, a complementary analytical workflow involving capillary gel electrophoretic (CGE) mobility shift assay, microcalorimetry and computational modeling has been deployed for the characterization of a series of free and surface-bound binary and ternary oligonucleotide interactions. As a proof of concept, the DNA analogue of MicroRNA 21 (miR21), a well-known oncogenic short MicroRNA (miRNA) sequence, has been chosen as a target molecule, simulating limiting-case scenarios involved in dual molecular recognition models exploited in affinity (bio)sensing. Novel data for the characterization of oligonucleotide interacting modules is revealed, offering a fast and complete mapping of the specific or non-specific, often competing, binary and ternary order interactions in dynamic equilibria, occurring between various free and metal surface-bound oligonucleotides.

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In this study, a series of aluminum-based layered metal oxide with various divalent metals (M2+Al-LMOs) were prepared and employed in activation of peroxymonosulfate (PMS) for bisphenol A (BPA) degradation. The BPA removal rates of M2+Al-LMOs were ordered as: CoAl(100%) > MnAl(75.6%) > CuAl(63.2%) > NiAl(9.0%) > MgAl = ZnAl-LMO(0%). CoAl-LMO showed the highest kinetic constant (k = 1.329 µmol-1gcat-1s-1), which was 3.95 times of MnAl-LMO, 5.36 times of CuAl-LMO, 88.6 times of NiAl-LMO and 443 times of MgAl-LMO and ZnAl-LMO, respectively, and also exhibited the highest TOC removal rate (83.3%). The surface-bound sulfate radical (SO4·-) and singlet oxygen (1O2) were elucidated as the dominant reactive oxygen species (ROS) for BPA degradation. The M2+Al-LMOs/PMS system not only displayed wide applicability in different pH and inorganic anions environments, but also had excellent stability and reusability. This work provides a novel family of M2+Al-LMOs to activate PMS for water treatment.

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Indirect electrochemical oxidation by hydroxyl radicals is the predominant degradation mechanism in electrolysis with a boron-doped diamond (BDD) anode. However, this electrochemical method exhibits low reactivity in removal of hydrophilic aromatic pollutants owing to mass transfer limitation. In this study, the combination of ultraviolet light and BDD electrolysis could increase the degradation rate of hydrophilic aromatic pollutants by approximately 8-10 times relative to electrolysis alone. According to the results of the scavenging experiments and identification of benzoic acid oxidation products, surface-bound hydroxyl radical (•OH(surface)) was the primary reactive species degrading aromatic pollutants in the BDD electrolysis process, whereas freely-diffusing homogeneous hydroxyl radical (•OH(free)) was the major reactive species in the UV-assisted BDD electrolysis process. Cyclic voltammetry revealed that UV light decomposed H2O2 formed on the BDD anode surface, thus retarding O2 evolution and facilitating •OH(free) generation. This work also explored the potential application of UV-assisted BDD electrolysis in removing COD from bio-pretreated landfill leachate containing high concentrations of hydrophilic aromatic pollutants. This study shed light on the importance of the existing state of •OH on removal of pollutants during BDD electrolysis, and provided a facile and efficient UV-assisted strategy for promoting degradation of hydrophilic aromatic pollutants.

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It is a challenge to simultaneously treat the combined pollutants of chromium(VI) (Cr(VI)) and organics (such as phenol) in wastewater. Here, a stable and efficient redox system based on FeS2 sulfidated zero valent iron (FeS2/Fe0) and persulfate (PS) was developed to synchronously remove Cr(VI) and phenol. 100% of phenol (10 mg/L) was oxidized in 10 min and Cr(VI) (20 mg/L) was completely reduced to Cr(III) in 90 min in the FeS2/Fe0+PS system with a pH range of 3.0-9.0, respectively. phenol was selectively oxidized without re-oxidizing Cr(III) in such system. The surface-bound Fe2+ was the major reactive species to synchronously reduce Cr(VI) and oxidize phenol. The mechanisms were elucidated that the phenol degradation was accelerated by the generated Cr(III) complexing with its products, and that SO42-, whose production speed was accelerated by the PS activation to oxidize phenol and FeS2, was conductive to corrode Fe0 to regenerate the surface-bound Fe2+ for reducing Cr(VI) and oxidizing phenol. It is potential to develop a high-performance and large-scaled FeS2/Fe0-based redox platform to remediate the complex pollution of Cr(VI) and organics.

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Measurements of fluorescence intensity of the hydrophobic pyridinium salt (DTPSH) remaining in the organic phase after partition experiments in the DCM/H2O system allowed an approximate method to be developed to estimate the mean number of molecules (N = 942) on the surface of 22.8 nm gold nanoparticles and the separation (1.89 nm) between these organic molecules. This protocol is based on the ability that the organic molecules possess to coat the surface of the nanoparticle, which can migrate from the organic to the aqueous phase as a result of the driving force of the strong binding of sulfur to gold. To validate our estimation, we used a projection of the results obtained by Wales and Ulker to solve the Thomson problem, a mathematicians' challenge, used as a model to calculate the mean distance (1.82 nm) separating particles on the surface, in excellent agreement with the results obtained by our method. The quality of results, the simplicity of calculations, the low fluorescence detection limit, and the inexpensive materials, recommend this procedure for rapid estimates of the mean number of molecules on the surface of nanoparticles.