Photoactivation of Chlorine and Its Catalytic Role in the Formation of Sulfate Aerosols.

We present a novel mechanism for the formation of photocatalytic oxidants in deliquescent NaCl particles, which can greatly promote the multiphase photo-oxidation of SO2 to produce sulfate. The photoexcitation of the [Cl--H3O+-O2] complex leads to the generation of Cl and OH radicals, which is the key reason for enhancing aqueous-phase oxidation and accelerating SO2 oxidation. The mass normalization rate of sulfate production from the multiphase photoreaction of SO2 on NaCl droplets could be estimated to be 0.80 × 10-4 µg·h-1 at 72% RH and 1.33 × 10-4 µg·h-1 at 81% RH, which is equivalent to the known O3 liquid-phase oxidation mechanism. Our findings highlight the significance of multiphase photo-oxidation of SO2 on NaCl particles as a non-negligible source of sulfate in coastal areas. Furthermore, this study underscores the importance of Cl- photochemistry in the atmosphere.

Tunable and Non-Invasive Printing of Transmissive Interference Colors with 2D Material Inks.

Interference colors hold significant importance in optics and arts. Current methods for printing interference colors entail complex procedures and large-scale printing systems for the scarcity of inks that exhibit both sensitivity and tunability to external fields. The production of highly transparent inks capable of rendering transmissive colors has presented ongoing challenges. Here, a type of paramagnetic ink based on 2D materials that exhibit polychrome in one magnetic field is invented. By precisely manipulating the doping ratio of magnetic elements within titanate nanosheets, the magneto-optical sensitivity named Cotton-Mouton coefficient is engineerable from 728 to a record high value of 3272 m-1 T-2, with negligible influence on its intrinsic wide optical bandgap. Combined with the sensitive and controllable magneto-responsiveness of the ink, modulate and non-invasively print transmissive interference colors using small permanent magnets are precised. This work paves the way for preparing transmissive interference colors in an energy-saving and damage-free manner, which can expand its use in widespread areas.

Ampere-Level Current Density CO2 Reduction with High C2+ Selectivity on La(OH)3-Modified Cu Catalysts.

The carbon dioxide reduction reaction (CO2RR) driven by electricity can transform CO2 into high-value multi-carbon (C2+) products. Copper (Cu)-based catalysts are efficient but suffer from low C2+ selectivity at high current densities. Here La(OH)3 in Cu catalyst is introduced to modify its electronic structure towards efficient CO2RR to C2+ products at ampere-level current densities. The La(OH)3/Cu catalyst has a remarkable C2+ Faradaic efficiency (FEC2+) of 71.2% which is 2.2 times that of the pure Cu catalyst at a current density of 1,000 mA cm-2 and keeps stable for 8 h. In situ spectroscopy and density functional theory calculations both show that La(OH)3 modifies the electronic structure of Cu. This modification favors *CO adsorption, subsequent hydrogenation, *CO─*COH coupling, and consequently increases C2+ selectivity. This work provides a guidance on facilitating C2+ product formation, and suppressing hydrogen evolution by La(OH)3 modification, enabling efficient CO2RR at ampere-level current densities.

Mesonia profundi sp. nov., isolated from deep-sea sediment of the Mariana Trench.

A Gram-stain-negative, aerobic, rod-shaped, non-flagellated, non-gliding bacterial strain, designated MT50T, was isolated from a deep-sea sediment sample collected from the Mariana Trench. Optimal growth of strain MT50T was observed at 25 °C, pH 7.0-7.5 and in the presence of 3-5 % (w/v) NaCl. The strain was positive for oxidase and catalase. Phylogenetic analysis of 16S rRNA gene sequences revealed that strain MT50T is affiliated with the genus Mesonia, showing the highest sequence similarity (98.5 %) to the type strain of Mesonia ostreae. The digital DNA-DNA hybridization and average nucleotide identity values between strain MT50T and four closely related type strains of known Mesonia species (14.1-54.8 % and 72.7-86.8 %, respectively) were all below the threshold values to discriminate bacterial species, indicating that strain MT50T is affiliated with a novel species within the genus. The genomic G+C content deduced from the genome of strain MT50T was 36.2 mol%. The major fatty acids of strain MT50T were iso-C15 : 0, iso-C17 : 0 3-OH and anteiso-C15 : 0. The predominant respiratory quinone of the strain was MK-6. The polar lipids of strain MT50T included phosphatidylethanolamine and two unidentified lipids. Based on the polyphasic data presented in this study, strain MT50T represents a novel species of the genus Mesonia, for which the name Mesonia profundi sp. nov. is proposed. The type strain is MT50T (=MCCC 1K07833T=KCTC 92380T).

Formation Mechanism of Environmentally Persistent Free Radicals on Alkaline Earth Oxide Surfaces.

The formation of environmentally persistent free radicals (EPFRs) is usually related to transition-metal oxides in particulate matter (PM). However, recent studies suggest that alkaline-earth-metal oxides (AEMOs) in PM also influence EPFRs formation, but the exact mechanism remains unclear. Here, density functional theory calculations were performed to investigate the formation mechanism of EPFRs by C6H5OH on AEMO (MgO, CaO, and BaO) surfaces and compare it with that on transition-metal oxide (ZnO and CuO) surfaces. Results indicate that EPFRs can be rapidly formed on AEMOs by dissociative adsorption of C6H5OH, accompanied by electrons transfer. As the alkalinity of AEMOs increases, both adsorption energy and the number of electron transfers gradually increase. Also, the stability of the formed EPFRs is mainly attributed to the electrostatic and van der Waals interactions between the phenoxy radical and surfaces. Notably, the formation mechanism of EPFRs on AEMOs is similar to that on ZnO but differs from that on CuO, as suggested through geometric structure and charge distribution analyses. This study not only elucidates the formation mechanisms of EPFRs on AEMOs but also provides theoretical insights into addressing EPFRs pollution.

Discovery of novel anaplastic lymphoma kinase (ALK) and histone deacetylase (HDAC) dual inhibitors exhibiting antiproliferative activity against non-small cell lung cancer.

A series of novel benzimidazole derivatives were designed and synthesised based on the structures of reported oral available ALK inhibitor and HDAC inhibitor, pracinostat. In enzymatic assays, compound 3b, containing a 2-acyliminobenzimidazole moiety and hydroxamic acid side chain, could inhibit both ALK and HDAC6 (IC50 = 16 nM and 1.03 µM, respectively). Compound 3b also inhibited various ALK mutants known to be involved in crizotinib resistance, including mutant L1196M (IC50, 4.9 nM). Moreover, 3b inhibited the proliferation of several cancer cell lines, including ALK-addicted H2228 cells. To evaluate its potential for treating cancers in vivo, 3b was used in a human A549 xenograft model with BALB/c nude mice. At 20 mg/kg, 3b inhibited tumour growth by 85% yet had a negligible effect on mean body weight. These results suggest a attracting route for the further research and optimisation of dual ALK/HDAC inhibitors.

Spontaneous molecular bromine production in sea salt aerosols.

Bromine chemistry is responsible for the catalytic ozone destruction in the atmosphere. The heterogeneous reactions of sea-salt aerosols are the main abiotic sources of reactive bromine in the atmosphere. Here, we present a novel mechanism for the activation of bromide ions (Br-) by O2 and H2O in the absence of additional oxidants. The laboratory and theoretical calculation results demonstrated that under dark conditions, Br-, O2 and H3O+ could spontaneously generate Br and HO2 radicals through a proton-electron transfer process at the air‒water interface and in the liquid phase. Our results also showed that light and acidity could significantly promote the activation of Br- and the production of Br2. The estimated gaseous Br2 production rate under light conditions was up to 1.55×1010 molecules·cm-2·s-1 under light and acidic conditions; these results showed a significant contribution to the atmospheric reactive bromine budget. The reactive oxygen species (ROS) generated during Br- activation could promote the multiphase oxidation of SO2 to produce sulfuric acid, while the increase in acidity had a positive feedback effect on Br- activation. Our findings highlight the crucial role of the proton-electron transfer process in Br2 production.

Chemical Implications of Rapid Reactive Absorption of I2O4 at the Air-Water Interface.

Marine aerosol formation involving iodine-bearing species significantly affects the global climate and radiation balance. Although recent studies outline the critical role of iodine oxide in nucleation, much less is known about its contribution to aerosol growth. This paper presents molecular-level evidence that the air-water interfacial reaction of I2O4 mediated by potent atmospheric chemicals, such as sulfuric acid (H2SO4) and amines [e.g., dimethylamine (DMA) and trimethylamine (TMA)], can occur rapidly on a picosecond time scale by Born-Oppenheimer molecular dynamics simulations. The interfacial water bridges the reactants while facilitating the DMA-mediated proton transfer and stabilizing the ionic products of H2SO4-involved reactions. The identified heterogeneous mechanisms exhibit the dual contribution to aerosol growth: (i) the ionic products (e.g., IO3-, DMAH+, TMAH+, and HSO4-) formed by reactive adsorption possess less volatility than the reactants and (ii) these ions, such as alkylammonium salts (e.g., DMAH+), are also highly hydrophilic, further facilitating hygroscopic growth. This investigation enhances not only our understanding of heterogeneous iodine chemistry but also the impact of iodine oxide on aerosol growth. Also, these findings can bridge the gap between the abundance of I2O4 in the laboratory and its absence in field-collected aerosols and provide an explanation for the missing source of IO3-, HSO4-, and DMAH+ in marine aerosols.

Generalized anxiety disorder among rural primary and middle school students during the outbreak of COVID-19: a multicenter study in three southern Chinese cities.

BACKGROUND: The major public health crisis caused by the rapid spread of the coronavirus disease 2019 (COVID-19) and the large-scale public health measures such as social isolation and school closures enforced by some countries have severely affected on the physical and mental wellbeing of children and adolescents globally. This study aimed to estimate the prevalence of the psychological impact and investigate the similarities and differences in the influential factors for generalized anxiety disorder among rural adolescents as a relatively lesser noticed population the outbreak of COVID-19. METHODS: From May 11 to 22, 2020, a total of 1,179 adolescents, including Grade 5-6 in primary school and Grade 7-8 in middle school, were selected by multistage sampling in three Southern Chinese cities (Shantou, Guangdong Province; Hezhou, Guangxi Province; Nanchong, Sichuan Province), and completed the questionnaires including sociodemographic, generalized anxiety disorder, academic stress, coronaphobia, knowledge of COVID-19, and precautionary measures. ANOVA, Chi-square test, Kruskalwallis H test and multivariate linear regression were performed in the statistical analysis. RESULTS: The average scores of generalized anxiety disorder during the past two weeks were 3.43 (SD 4.46), 4.47 (SD 5.15), and 4.10 (SD 4.94) in Shantou, Hezhou and Nanchong, respectively. For the pooled data, academic stress (P < 0.001), coronaphobia (P < 0.001), and precautionary measures (P = 0.002) contributed to the prediction of anxiety scores. Academic stress was significantly associated to anxiety symptoms in all cities (P all < 0.001). Coronaphobia was also significantly associated to anxiety symptoms in all cities (P all < 0.001). CONCLUSION: This study highlights the urgent need for researchers and policymakers to focus on the mental health of rural children and adolescents during the COVID-19 epidemic. The adolescents with academic stress and coronaphobia, the greater the risk that adolescents will suffer from anxiety, suggesting mental health counseling and professional family support are needed.

Histochemical localization of putative stem cells in irreversible pulpitis.

OBJECTIVES: Our study aimed to observe the distribution of putative stem cells in irreversible pulpitis and to investigate the expression of specific molecules. SUBJECTS AND METHODS: Extracted third molar teeth were collected and divided into two groups: the normal pulp group and inflamed pulp group. Real-time PCR was applied to detect the expression of several embryonic and dentinogenic genes. The expression of mesenchymal cell markers (STRO-1, CD90, and CD146) and stromal cell-derived factor 1α (SDF-1α)/CXC chemokine receptor 4 (CXCR4) proteins was examined by immunohistochemical analysis. RESULTS: The expression levels of most embryonic and dentinogenic genes were not statistically different between the two groups. Immunohistochemical analysis revealed that in inflamed pulp, cells with positive expression for STRO-1, CD90, and CD146 mainly resided in two specific niches, both adjacent to inflammatory sites: one in the pulp core and another in the odontoblast layer. SDF-1α- and CXCR4-positive cells were significantly correlated with STRO-1-positive cells. Double immunofluorescence analysis indicated that STRO-1-positive cells overlapped with SDF-1α- and CXCR4-positive cells near the inflammatory site. CONCLUSIONS: This study gave a direct observation of putative stem cells distributed in irreversible pulpitis and implied a role of SDF-1α/CXCR4 signaling in stem cell-based therapies for reparative dentinogenesis.

Treatment of Idiopathic Membranous Nephropathy for Moderate or Severe Proteinuria: A Systematic Review and Network Meta-Analysis.

Objective: Numerous studies have demonstrated that the efficacy of drugs differs in idiopathic membranous nephropathy (IMN) patients with moderate or high proteinuria. However, there is no systematic comparison confirming it. This network meta-analysis (NMA) was performed to respectively compare the efficacy of ten IMN treatments in patients with moderate and high proteinuria and compare the risk of adverse events with 10 IMN regimens. Methods: Randomized controlled trials (RCTs) and observational studies analyzing the main therapeutic regimens for IMN were included from some databases. Network comparisons were performed to analyze the rates of total remission (TR), bone marrow suppression, and gastrointestinal symptoms. The surface under the cumulative ranking area (SUCRA) was calculated to rank interventions. Results: Seventeen RCTs and eight observational studies involving 1778 patients were pooled for comparison of ten interventions. Steroid + tacrolimus (TAC) showed the highest probabilities of TR whether patients had severe proteinuria or not (SUCRA 89.5% and 88.9%, separately). Rituximab (RTX) was more beneficial for TR on patients with proteinuria <8 g/d (SUCRA 66.0%) and was associated with a lower risk of bone marrow suppression and gastrointestinal symptoms (SUCRA 21.7% and 21.4%, separately). TAC + RTX and steroids + cyclophosphamide induced the highest rates of bone marrow suppression (SUCRA 90.6% and 88.3%, separately) and gastrointestinal symptoms (SUCRA 86.0% and 72.1%, separately). Conclusions: Steroids + TAC showed significant efficacy in patients with all degrees of proteinuria, while RTX was more effective in patients with moderate proteinuria and was safer in bone marrow suppression and gastrointestinal symptoms.

Effects of BMAL1 on dentinogenic differentiation of dental pulp stem cells via PI3K/Akt/mTOR pathway.

AIM: This study aimed to investigate the effect of the circadian clock gene Bmal1 on dentinogenic differentiation of dental pulp stem cells (DPSCs) under inflammatory conditions. METHODOLOGY: Dental pulp stem cells were isolated from the pulp tissue of the healthy donor and were then stimulated with different concentrations of lipopolysaccharide (LPS) to mimic inflammatory conditions. Real-time polymerase chain reaction was used to detect the gene expression of circadian clock genes Bmal1, Clock, Per1, Per2, Cry1, and Cry2. Western blot (WB) was applied to analyse the protein expression of circadian clock proteins (BMAL1, CLOCK) and dentinogenic differentiation-related proteins (DSPP, DMP1). In addition, the apoptosis and osteogenic differentiation of DPSCs were also analysed in the presence of different concentrations of LPS. RESULTS: The expression of circadian clock genes of DPSCs significantly changed in an inflammatory environment. WB analysis shows that BMAL1 is relevant to the dentinogenic differentiation of DPSCs. In low concentrations of LPS-mimicked inflammatory conditions, the expression of BMAL1 increased and promoted the dentinogenic differentiation of DPSCs. However, under high concentrations of LPS-mimicked inflammatory conditions, the expression of BMAL1 decreased and inhibited the dentinogenic differentiation of DPSCs. Moreover, the effects of BMAL1 on dentinogenic differentiation of DPSCs may be through PI3K/Akt/mTOR pathway. CONCLUSIONS: This study showed that the circadian clock gene Bmal1 affected dentinogenic differentiation of DPSCs, providing a new insight for clinical stem cell-based restorative dentinogenesis therapies.

[A review on voluntary or involuntary eye movement classification methods based on electro-oculogram and their applications].

The eye-computer interaction technology based on electro-oculogram provides the users with a convenient way to control the device, which has great social significance. However, the eye-computer interaction is often disturbed by the involuntary eye movements, resulting in misjudgment, affecting the users' experience, and even causing danger in severe cases. Therefore, this paper starts from the basic concepts and principles of eye-computer interaction, sorts out the current mainstream classification methods of voluntary/involuntary eye movement, and analyzes the characteristics of each technology. The performance analysis is carried out in combination with specific application scenarios, and the problems to be solved are further summarized, which are expected to provide research references for researchers in related fields.

The potential mechanism of atmospheric new particle formation involving amino acids with multiple functional groups.

Amino acids are recognized as significant components of atmospheric aerosols. However, their potential role in atmospheric new particle formation (NPF) is poorly understood, especially aspartic acid (ASP), one of the most abundant amino acids in the atmosphere. It has not only two advantageous carboxylic acid groups but also one amino group, both of which are both effective groups enhancing NPF. Herein, the participation mechanism of ASP in the formation of new particle involving sulfuric acid (SA)-ammonia (A)-based system has been studied using the Density Functional Theory (DFT) combined with the Atmospheric Clusters Dynamic Code (ACDC). The results show that the addition of ASP molecules in the SA-A-based clusters provides a promotion on the interaction between SA and A molecules. Moreover, ACDC simulations indicate that ASP could present an obvious enhancement effect on SA-A-based cluster formation rates. Meanwhile, the enhancement strength R presents a positive dependence on [ASP] and a negative dependence on [SA] and [A]. Besides, the enhancement effect of ASP is compared with that of malonic acid (MOA) with two carboxylic acid groups (Chemosphere, 2018, 203, 26-33), and ASP presents a more obvious enhancement effect than MOA. The mechanism of NPF indicates that ASP could contribute to cluster formation as a "participator" which is different from the "catalytic" role of MOA at 238 K. These new insights are helpful to understand the mechanism of NPF involving organic compounds with multiple functional groups, especially the abundant amino acids, such as the ASP, in the urban/suburban areas with intensive human activities and industrial productions and therefore the abundant sources of amino acids. Furthermore, the NPF of the SA-A-based system involving amino acid should be considered when assessing the environmental risk of amino acid.

Catalytic sulfate formation mechanism influenced by important constituents of cloud water via the reaction of SO2 oxidized by hypobromic acid in marine areas.

Comprehensive investigations of the possible formation pathways of sulfate, the main composition of atmospheric aerosol in marine areas, continue to challenge atmospheric chemists. As one of the most important oxidation routes of S(iv) contributing to sulfate formation, the reaction process of S(iv) oxidized by hypobromic acid, which is ubiquitous with the gas-phase mixing ratios of ∼310 ppt and has a well-known oxidative capacity, has attracted wide attention. However, little information is available about the detailed reaction mechanism. Especially, due to the abundant species in cloud water, the potential effect of these compositions on these reaction processes and the corresponding effect mechanism are also uncertain. Using high-level quantum chemical calculations, we theoretically elucidate the two-step mechanism of Br+ transfer proposed by experiment through the verification of the key BrSO3- intermediate formation and subsequent hydrolysis reaction or the uncovered reaction of BrSO3- intermediate with OH-. Further, the novel and more competitive mechanisms (OH+ or O atom transfer pathways) that have not been considered in previous studies, leading to sulfate formation directly, have been found. Furthermore, it should be mentioned that we revealed the effect mechanism of constituents catalyzed in cloud water, especially the important H2O-catalyzed mechanism. In addition, all the above pathways follow this catalytic mechanism. This finding indicates a linkage between the complex nature of the atmospheric constituents and related atmospheric reaction, as well as the enhanced occurrence of atmospheric secondary sulfate formation in the atmosphere. Hence, this exploration of sulfate formation related to hypobromic acid could provide a better understanding about the sources of sulfate in marine areas.

Inhibitor development of MTH1 via high-throughput screening with fragment based library and MTH1 substrate binding cavity.

MutT Homolog 1 (MTH1) has been proven to hydrolyze oxidized nucleotide triphosphates during DNA repair. It can prevent the incorporation of wrong nucleotides during DNA replication and mitigate cell apoptosis. In a cancer cell, abundant reactive oxygen species can lead to substantial DNA damage and DNA mutations by base-pairing mismatch. MTH1 could eliminate oxidized dNTP and prevent cancer cells from entering cell death. Therefore, inhibition of MTH1 activity is considered to be an anti-cancer therapeutic target. In this study, high-throughput screening techniques were combined with a fragment-based library containing 2,313 compounds, which were used to screen for lead compounds with MTH1 inhibitor activity. Four compounds with MTH1 inhibitor ability were selected, and compound MI0639 was found to have the highest effective inhibition. To discover the selectivity and specificity of this action, several derivatives based on the MTH1 and MI0639 complex structure were synthesized. We compared 14 complex structures of MTH1 and the various compounds in combination with enzymatic inhibition and thermodynamic analysis. Nanomolar-range IC50 inhibition abilities by enzyme kinetics and Kd values by thermodynamic analysis were obtained for two compounds, named MI1020 and MI1024. Based on structural information and compound optimization, we aim to provide a strategy for the development of MTH1 inhibitors with high selectivity and specificity.

Glyoxylic Sulfuric Anhydride from the Gas-Phase Reaction between Glyoxylic Acid and SO3: A Potential Nucleation Precursor.

Oxocarboxylic acids, one of the most important organic species, are detected in aerosols in various environments. Recent studies suggest that the gas-phase reactions between carboxylic acids and SO3 could form carboxylic sulfuric anhydrides, which might participate in nucleation. Here, glyoxylic acid (GA), the most abundant oxocarboxylic acid in the atmosphere, has been selected as an example to study the reactions between oxocarboxylic acids and SO3 and the nucleation potentials of products. The reaction between GA and SO3 that generates glyoxylic sulfuric anhydride (GSA) and the hydrolysis of GSA are investigated using computational methods. The results show that the reaction is almost barrierless, and GSA is stable against water. Additionally, the clusters of GSA and common nucleation species (sulfuric acid and ammonia) are more stable than the analogous clusters of GA, because they have more hydrogen bonds and proton transfers. It suggests that GA tends to transfer itself to a much better nucleation precursor, GSA, through a reaction with SO3, and GSA can drive nucleation and contribute to new particle formation (NPF). This mechanism might be general for all oxocarboxylic acids and could help to deeply understand the roles of oxocarboxylic acids in NPF.

The in vitro antimicrobial activities of four endodontic sealers.

BACKGROUND: The purpose of this study was to investigate the antimicrobial activities of four endodontic sealers (GuttaFlow2, AH Plus, ProRoot MTA and RealSeal) against E. feacalis, E.coli and C.albicans. METHODS: The antimicrobial activities of four endodontic sealers were assessed by both agar diffusion test (ADT) and direct contact test (DCT) in this study. In ADT, the results were reported as the diameter of the growth inhibition zone. Both fresh and 1-day-setting sealers were measured. In DCT, microorganisms in suspension were exposed to the sealers for 10, 30 and 60 min and the survival of microorganisms were determined after exposure at different time points(after mixing, 1 and 7 days). The number of colony-forming unit (CFU) was counted. The results were analyzed with ANOVA and Tukey tests. RESULTS: Both ADT and DCT results showed that Guttaflow2 presented no effect against any tested microorganisms. In ADT, fresh RealSeal had the largest inhibition zone against all tested microbes, followed by AH Plus and ProRoot MTA. ProRoot MTA demonstrated inhibition zones against all the three test microbes after setting for 1 day, while the other three sealers showed no inhibition activity. In DCT, fresh AH Plus had the strongest antimicrobial effects against all the three tested microorganisms for every contact times, while its antimicrobial activity diminished significantly with time. Fresh RealSeal and ProRoot MTA also showed strong antimicrobial effect and still showed antimicrobial effect after 1-day-setting. The antibacterial effects of RealSeal against E. faecalis and antifungal effect of ProRoot MTA were observed after 7 days of setting. CONCLUSIONS: GuttaFlow2 had no antimicrobial activity. Freshly mixed RealSeal and AH Plus demonstrated strong antimicrobial effects. RealSeal showed antimicrobial effects after setting in DCT. ProRoot MTA showed high antimicrobial activity and exhibited anti-inflammation potentials after setting.

Mechanistic Insight into the Reaction of Organic Acids with SO3 at the Air-Water Interface.

The gas-phase reaction of organic acids with SO3 has been recognized as essential in promoting aerosol-particle formation. However, at the air-water interface, this reaction is much less understood. We performed systematic Born-Oppenheimer molecular dynamics (BOMD) simulations to study the reaction of various organic acids with SO3 on a water droplet. The results show that with the involvement of interfacial water molecules, organic acids can react with SO3 and form the ion pair of sulfuric-carboxylic anhydride and hydronium. This mechanism is in contrast to the gas-phase reaction mechanisms in which the organic acid either serves as a catalyst for the reaction between SO3 and H2 O or reacts with SO3 directly. The distinct reaction at the water surface has important atmospheric implications, for example, promoting water condensation, uptaking atmospheric condesation species, and incorporating "SO4 2- " into organic species in aerosol particles. Therefore, this reaction, typically occurring within a few picoseconds, provides another pathway towards aerosol formation.

A highly HDAC6-selective inhibitor acts as a fluorescent probe.

HDAC6 receives great attention because of its therapeutic potential for the treatment of various diseases. Selective fluorescence imaging for HDAC6 is important for its pathological and biological studies. However, specific detection of HDAC6 by using a fluorescent small molecule probe remains a great challenge. Herein, a series of fluorescent HDAC6-selective inhibitors incorporating a naphthalimide skeleton were designed and synthesized. A structure-activity relationship study identified that compound JW-1 had the greatest inhibitory activity and superior specificity against HDAC6. JW-1 could substantially increase α-tubulin acetylation and was active against a panel of six cancer cell lines. Photophysical characterization and cellular imaging of MDA-MB-231 cells demonstrated that JW-1 is a highly fluorescent, cell penetrable, small-molecule inhibitor of HDAC6 that can be used for the detection of HDAC6 in complex cellular environments.