PVP Passivated δ-CsPbI3: Vacancy Induced Visible-Light Absorption and Efficient Photocatalysis.

The aqueous instability of halide perovskite seriously hinders its direct application in water as a potential photocatalyst. Here, we prepared a new type of polyvinylpyrrolidone (PVP) passivated δ-CsPbI3 (δ-CsPbI3@PVP) microcrystal by a facile method. This material can be uniformly dispersed in water and stably maintain its crystal structure for a long time, breaking through the bottleneck of halide perovskite photocatalysis in water. Under visible light, δ-CsPbI3@PVP can almost completely photodegrade organic dyes (including Rhodamine B, methylene blue, and crystal violet) in only 20 min. The efficient photocatalytic activity is attributed to the enhanced visible light absorption arising from PbI2 defects in δ-CsPbI3@PVP and the intrinsic low photoluminescence quantum yield of δ-CsPbI3, which induces efficient light absorption and photocatalytic activity. We highlight δ-CsPbI3@PVP as an effective aqueous photocatalyst, and this study provides new insights into how to exploit the potential of halide perovskite in photocatalytic applications.

[Inhibition of GMA-induced ubiquitination process in 16HBE malignantly transformed cells on protein CD44 and MMP14].

OBJECTIVE: To observe the effect of the ubiquitination process on the expression of CD44 antigen(CD44) and matrix metalloproteinase-14(MMP14) in human bronchial epithelial(16HBE) malignantly transformed cells induced by glycidyl methacrylate(GMA). METHODS: Successfully resuscitated 16HBE cells were cultured using a final concentration of 8 µg/mL GMA as the treatment group and 1 µg/mL dimethyl sulfoxide as the solvent control group, each time stained for 72 h, and then stained again after an interval of 24 h. After repeating the staining three times, the cells were cultured in passages respectively. The 40th generation(P40) GMA-treated group and the same-generation solvent control group were subjected to soft agar colony formation assay and concanavalin A(ConA) agglutination test to confirm that the 40th generation of GMA-induced malignant transformed 16HBE cells possessed malignant transformed cell characteristics.5, 10, 20, 40, 60 µmol/L anacardic acid were used to inhibit the ubiquitination process of GMA-induced malignant transformed 16HBE cells. The protein expression of CD44 and MMP14 were detected by western blotting, while the transcript levels of CD44, MMP14, and TFAP2A were assessed by real-time fluorescence quantitative PCR(qPCR). RESULTS: (1) In the soft agar colony formation assay, the number of clones formed by the cells in the solvent control group was 22, and the number of clones created by the malignantly transformed cells in the GMA-treated group was 208. In the ConA agglutination test, the cells in the solvent control group were uniformly dispersed in ConA solution, and no obvious agglutination occurred for 30 min, whereas the cells in the GMA-treated group were agglutinated in the 5th min, and the agglutinated cells were larger and more rapidly agglutinated. The agglomerates were more significant and faster, and the sensitivity of agglutination was increased. (2) After differential inhibition of GMA-induced ubiquitination in malignantly transformed 16HBE cells, the expression levels of CD44 and MMP14 were reduced in GMA-induced malignantly transformed 16HBE cells compared with the control group(P<0.05). The transcript levels of MMP14 and CD44 decreased with increasing inhibitor concentration(P<0.05), and the transcript levels of the upstream transcription factor TFAP2A were also simultaneously reduced(P<0.05). CONCLUSION: Inhibition of the cellular ubiquitination process mediates the down-regulation of protein expression and transcriptional expression of CD44 and MMP14 in GMA-induced malignantly transformed 16HBE cells.

Nitrogen-Doped Graphene Quantum Dot-Passivated δ-Phase CsPbI3: A Water-Stable Photocatalytic Adjuvant to Degrade Rhodamine B.

Inorganic halide perovskite CsPbI3 is highly promising in the photocatalytic field for its strong absorption of UV and visible light. Among the crystal phases of CsPbI3, the δ-phase as the most aqueous stability; however, directly using it in water is still not applicable, thus limiting its dye photodegradation applications in aqueous solutions. Via adopting nitrogen-doped graphene quantum dots (NGQDs) as surfactants to prepare δ-phase CsPbI3 nanocrystals, we obtained a water-stable material, NGQDs-CsPbI3. Such a material can be well dispersed in water for a month without obvious deterioration. High-resolution transmission electron microscopy and X-ray diffractometer characterizations showed that NGQDs-CsPbI3 is also a δ-phase CsPbI3 after NGQD coating. The ultraviolet-visible absorption spectra indicated that compared to δ-CsPbI3, NGQDs-CsPbI3 has an obvious absorption enhancement of visible light, especially near the wavelength around 521 nm. The good dispersity and improved visible-light absorption of NGQDs-CsPbI3 benefit their aqueous photocatalytic applications. NGQDs-CsPbI3 alone can photodegrade 67% rhodamine B (RhB) in water, while after compositing with TiO2, NGQDs-CsPbI3/TiO2 exhibits excellent visible-light photocatalytic ability, namely, it photodegraded 96% RhB in 4 h. The strong absorption of NGQDs-CsPbI3 in the visible region and effective transfer of photogenerated carriers from NGQDs-CsPbI3 to TiO2 play the key roles in dye photodegradation. We highlight NGQDs-CsPbI3 as a water-stable halide perovskite material and effective photocatalytic adjuvant.

Impact of online public opinion regarding the Japanese nuclear wastewater incident on stock market based on the SOR model.

The exposure of the Japanese nuclear wastewater incident has shaped online public opinion and has also caused a certain impact on stocks in aquaculture and feed industries. In order to explore the impact of network public opinion caused by public emergencies on relevant stocks, this paper uses the stimulus organism response(SOR) model to construct a framework model of the impact path of network public opinion on the financial stock market, and it uses emotional analysis, LDA and grounded theory methods to conduct empirical analysis. The study draws a new conclusion about the impact of online public opinion on the performance of relevant stocks in the context of the nuclear waste water incident in Japan. The positive change of media sentiment will lead to the decline of stock returns and the increase of volatility. The positive change of public sentiment will lead to the decline of stock returns in the current period and the increase of stock returns in the lag period. At the same time, we have proved that media attention, public opinion theme and prospect theory value have certain influences on stock performance in the context of the Japanese nuclear wastewater incident. The conclusion shows that after the public emergency, the government and investors need to pay attention to the changes of network public opinion caused by the event, so as to avoid the possible stock market risks.

TMT-based quantitative proteomic analysis reveals the underlying mechanisms of glycidyl methacrylate-induced 16HBE cell malignant transformation.

Glycidyl methacrylate (GMA) has been widely used as tackifying/crosslinking copolymer monomer in the industrial section. Occupational and environmental exposure to GMA is inevitable. GMA is classified as a Group 2 A carcinogen. However, it still lacks a sufficient understanding of its carcinogenicity at the protein level. The major pathways and players during the malignant transformation process remain unknown. In this study, we first established and characterized a malignant transformation model using human bronchial epithelial (16HBE) cells exposed to 8 µg/mL GMA. Then the proteomics approach, western-blot analysis as well as quantitative PCR (qPCR) analysis were employed to investigate its underlying mechanisms of carcinogenicity. Our results showed that the 16HBE cells exposed to GMA and passaged to the 40th generation had undergone a malignant transformation. Proteomic analysis revealed that 123 proteins were significantly up-regulated while 160 proteins were down-regulated during the process of malignant transformation. Importantly, further pathway analysis identified the extracellular matrix-receptor (ECM-receptor) interaction pathway to be one of the major players mediating the process and most of the differentially expressed proteins (DEPs) were up-regulated, including two vital proteins, CD44 and MMP14, as well as members from integrin family. These results provide direct proteomic evidence that DEPs related to the ECM-receptor interaction pathway play an active role in reinforcing the carcinogenicity of GMA. The findings of this study might deepen our understanding of the underlying mechanisms of GMA carcinogenicity and thus facilitate the risk assessment of GMA.

Physicochemical Properties of Granular and Gelatinized Lotus Rhizome Starch with Varied Proximate Compositions and Structural Characteristics.

As a traditional and popular dietary supplement, lotus rhizome starch (LRS) has health benefits for its many nutritional components and is especially suitable for teenagers and seniors. In this paper, the approximate composition, apparent amylose content (AAC), and structural characteristics of five LRS samples from different regions were investigated, and their correlations with the physicochemical properties of granular and gelatinized LRS were revealed. LRS exhibited rod-shaped and ellipsoidal starch granules, with AAC ranging from 26.6% to 31.7%. LRS-3, from Fuzhou, Jiangxi Province, exhibited a deeper hydrogel color and contained more ash, with 302.6 mg/kg iron, and it could reach the pasting temperature of 62.6 °C. In comparison, LRS-5, from Baoshan, Yunnan Province, exhibited smoother granule surface, less fragmentation, and higher AAC, resulting in better swelling power and freeze-thaw stability. The resistant starch contents of LRS-3 and LRS-5 were the lowest (15.3%) and highest (69.7%), respectively. The enzymatic digestion performance of LRS was positively correlated with ash content and short- and long-term ordered structures but negatively correlated with AAC. Furthermore, the color and network firmness of gelatinized LRS was negatively correlated with its ash content, and the retrograde trend and freeze-thaw stability were more closely correlated with AAC and structural characteristics. These results revealed the physicochemical properties of LRS from different regions and suggested their advantages in appropriate applications as a hydrogel matrix.

Isomerization of Aziridines to Allyl Amines via Titanium and Chromium Cooperative Catalysis.

A Ti/Cr cooperative catalyst isomerizes aziridines to allyl amines under mild conditions. The reaction tolerates a broad range of aziridines with various nitrogen substituents. The titanium catalyst is most successful in opening 1,2-disubstituted aziridines, forming radical intermediates in a highly regioselective manner. The chromium catalyst appears to abstract an H• from these radical intermediates and then return the H• to the titanium system in the form of an H+ and an electron. The reaction is complementary to previous reports on the isomerization of aziridines to allyl amines.

Mental Representations of Time in English Monolinguals, Mandarin Monolinguals, and Mandarin-English Bilinguals.

This study recruited English monolinguals, Mandarin monolinguals, and Mandarin-English (ME) bilinguals to examine whether native English and native Mandarin speakers think about time differently and whether the acquisition of L2 English could reshape native Mandarin speakers' mental representations of temporal sequence. Across two experiments, we used the temporal congruency categorization paradigm which involved two-alternative forced-choice reaction time tasks to contrast experimental conditions that were assumed to be either compatible or incompatible with the internal spatiotemporal associations. Results add to previous studies by confirming that native English and native Mandarin speakers do think about time differently, and the significant crosslinguistic discrepancy primarily lies in the vertical representations of time flow. However, current findings also clarify the existing literature, demonstrating that the acquisition of L2 English does not appear to affect native Mandarin speakers' temporal cognition. ME bilinguals, irrespective of whether they attained elementary or advanced level of English proficiency, exhibited temporal thinking patterns commensurate with those of Mandarin monolinguals. Some theoretical implications regarding the effect of bilingualism on cognition in general can be drawn from the present study, a crucial one being that it provides evidence against the view that L2 acquisition can reshape habitual modes of thinking established by L1.

Highly Selective Hydrogenation of C═C Bonds Catalyzed by a Rhodium Hydride.

Under mild conditions (room temperature, 80 psi of H2) Cp*Rh(2-(2-pyridyl)phenyl)H catalyzes the selective hydrogenation of the C═C bond in α,ß-unsaturated carbonyl compounds, including natural product precursors with bulky substituents in the ß position and substrates possessing an array of additional functional groups. It also catalyzes the hydrogenation of many isolated double bonds. Mechanistic studies reveal that no radical intermediates are involved, and the catalyst appears to be homogeneous, thereby affording important complementarity to existing protocols for similar hydrogenation processes.

Based on BATMAN-TCM to Explore the Molecular Mechanism of Xihuang Pill Regulating Immune Function to Treat Breast Precancerous Lesions.

OBJECTIVE: The specific mechanism of Xihuang Pill in the treatment of breast precancerous lesions and breast cancer has not yet been elucidated. METHODS: In our study, BATMAN-TCM (a Bioinformatics Analysis Tool for Molecular mechanisms of Traditional Chinese Medicine) was used to forecast the relationship among chemical components, immune targets, and diseases of each herb in Xihuang Pill and constructed a component-target-disease network. Taking breast precancerous lesion model rats as the research object, the molecular mechanism of Xihuang Pill regulating immunity was analyzed. RESULTS: BATMAN-TCM prediction showed that 309 genes were enriched in the biological process of "immune system response", which was the target of Xihuang Pill to regulate the immune system. The target of breast cancer disease and the genes related to Xihuang Pill's immune system response were crossed, and 88 cross genes were obtained. According to the enrichment results of GO/KEGG pathway, T cell activation was found to be the most relevant. We select Th1 cells (IL-2, IFN-γ) and Th2 cells (IL-4, IL-10) among them for animal experiment verification. The results show that Xihuang Pill can upregulate the serum IFN-γ and IL-2 levels, reduce the IL-4 and IL-10 levels, and regulate the balance of Th1/Th2 cells in the peripheral blood of rats with breast precancerous lesions. CONCLUSION: Xihuang Pill targets a variety of immune-related molecules related to breast precancerous lesions and is a traditional Chinese medicine formula that effectively regulates immune function.

Stereoselective Base-Catalyzed 1,1-Silaboration of Terminal Alkynes.

A base-catalyzed reaction that enables stereoselective 1,1-silaboration of terminal alkynes is described. This method not only offers a new strategy to functionalize simple and readily accessible alkynes beyond 1,2-difunctionalization, but also provides an unconventional atom- and step-economical approach to rapidly and reliably access versatile geminal silylboranes in the absence of transition metals and with exquisite stereoselectivity.

Iron-Catalyzed Reactions of 2-Pyridone Derivatives: 1,6-Addition and Formal Ring Opening/Cross Coupling.

In the presence of simple iron salts, 2-pyridone derivatives react with Grignard reagents under mild conditions to give the corresponding 1,6-addition products; if the reaction medium is supplemented with an aprotic dipolar cosolvent after the actual addition step, the intermediates primarily formed succumb to ring opening, giving rise to non-thermodynamic Z,E-configured dienoic acid amide derivatives which are difficult to make otherwise. Control experiments as well as the isolation and crystallographic characterization of a (tricarbonyl)iron pyridone complex suggest that the active iron catalyst generated in situ exhibits high affinity to the polarized diene system embedded into the heterocyclic ring system of the substrates, which likely serves as the actual recognition element.

A Mild and Direct Site-Selective sp2 C-H Silylation of (Poly)Azines.

A base-mediated protocol that allows for the site-selective sp2 C-H silylation of azines is described. This method is distinguished by its mild conditions, simplicity and excellent site-selective modulation for a diverse set of azines, even in the context of late-stage functionalization, while exhibiting orthogonal reactivity with classical silylation reactions.

sp3 C-H Arylation and Alkylation Enabled by the Synergy of Triplet Excited Ketones and Nickel Catalysts.

Triplet ketone sensitizers are of central importance within the realm of photochemical transformations. Although the radical-type character of triplet excited states of diaryl ketones suggests the viability for triggering hydrogen-atom transfer (HAT) and single-electron transfer (SET) processes, among others, their use as multifaceted catalysts in C-C bond-formation via sp3 C-H functionalization of alkane feedstocks still remains rather unexplored. Herein, we unlock a modular photochemical platform for forging C( sp3)-C( sp2) and C( sp3)-C( sp3) linkages from abundant alkane sp3 C-H bonds as functional handles using the synergy between nickel catalysts and simple, cheap and modular diaryl ketones. This method is distinguished by its wide scope that is obtained from cheap catalysts and starting precursors, thus complementing existing inner-sphere C-H functionalization protocols or recent photoredox scenarios based on iridium polypyridyl complexes. Additionally, such a platform provides a new strategy for streamlining the synthesis of complex molecules with high levels of predictable site-selectivity and preparative utility. Mechanistic experiments suggest that sp3 C-H abstraction occurs via HAT from the ketone triplet excited state. We believe this study will contribute to a more systematic utilization of triplet excited ketones as catalysts in metallaphotoredox scenarios.

Ni-Catalyzed Stannylation of Aryl Esters via C-O Bond Cleavage.

A Ni-catalyzed stannylation of aryl esters with air- and moisture-insensitive silylstannyl reagents via Csp2 -O cleavage is described. This protocol is characterized by its wide scope, including challenging combinations, thus enabling access to versatile building blocks and orthogonal C-heteroatom bond formations.

Palladium(0)-Catalyzed Intermolecular Allylic Dearomatization of Indoles by a Formal [4+2] Cycloaddition Reaction.

Bridged indoline derivatives were synthesized by an intermolecular Pd-catalyzed allylic dearomatization reaction of substituted indoles. The reaction between indoles and allyl carbonates bearing a nucleophilic alcohol side-chain proceeds in a cascade fashion, providing bridged indolines in excellent enantioselectivity.

Phosphine-Catalyzed Addition/Cycloaddition Domino Reactions of ß'-Acetoxy Allenoate: Highly Stereoselective Access to 2-Oxabicyclo[3.3.1]nonane and Cyclopenta[a]pyrrolizine.

Two classes of phosphine-catalyzed addition/cycloaddition domino reactions of ß'-acetoxy allenoate 1 have been developed. The reaction of 1 with 2-acyl-3-methyl-acrylonitrile 2 readily occurs to give 2-oxabicyclo[3.3.1]nonane 3, furnishing the ß'-addition/[4 + 4] cycloaddition domino sequence. In this sequence, ß'C of allenoate 1 is an electrophilic center, and its ß'C and γC serve as a 1,4-dipole. When the other reaction partner is switched to 2-acyl-3-(2-pyrrole)-acrylonitrile 8, a γ-addition/[3 + 2] cycloaddition domino reaction is instead observed, in which allenoate 1 exhibits dual electrophilic reactivity of γC and 1,3-dipole chemical behavior of ßC and ß'C. Furthermore, both of these two asymmetric variants have also been achieved with up to 93% ee. The domino reactions presented in this report are valuable for highly stereoselective construction of complex structures under mild reaction conditions.

Tertiary amine-catalyzed (4 + 2) annulations of δ-acetoxy allenoates: synthesis of multisubstituted 4H-pyran and 4H-chromene.

The DABCO-catalyzed divergent (4 + 2) annulations of δ-acetoxy allenoates 1 are reported. The chemical behavior of 1 under DABCO catalyst was found to be substrate dependent. Allenoate 1 with an aromatic group at δC preferentially reacted with salicylaldehyde derivative 2, delivering 4H-chromenes 3. On the other hand, allenoates 1 with an alkyl group at δC readily underwent (4 + 2) annulations with oxo diene 4 to afford 4H-pyrans 5.

[Determination of 2, 4-dichlorophenoxyacetic acid in air of workplace by high-performance liquid chromatography].

OBJECTIVE: To develop a method for determination of 2, 4-dichlorophenoxyacetic acid (2, 4-D) in the air of workplace by high-performance liquid chromatography. METHODS: 2, 4-D was collected by ultrafine glass filters, desorbed by methanol, separated by a C18 column, and detected by a UV detector. Identification and quantification of 2, 4-D were performed by retention time and peak areas, respectively. RESULTS: The linear range of the test was 2∼200 µg/ml; the elution efficiency was 94.6%- 95.9%; the limit of detection (S/N = 3) was 0.034 µg/ml (injection volume of 20 µl eluant); the lower limit of quantification (S/N = 10) was 0.11 µg/ml; the minimum detectable concentration was 0.011 mg/m(3); the minimum quantifiable concentration was 0.037 mg/m(3) (with sampled air volume of 45 L). CONCLUSION: This method is convenient and simple in sample collection and preparation, and satisfies all methodological requirements. Therefore, this method is useful for the determination of 2, 4-D in the air of workplace.