Mechanism of Gas-Phase Ozonolysis of β‑Myrcene in the Atmosphere

β-Myrcene is one of the major monoterpenes in the atmosphere. Ozonolysis is one of the oxidation removal processes for myrcene in the atmosphere during the daytime. In this study, the mechanism of myrcene ozonolysis is studied using high-level quantum chemistry calculations and kinetic calculations. The reaction starts with the formation of primary ozonides (POZs), which decompose to three primary product channels as 4-vinyl-4-pentenal (<b>4V4P</b>) + (CH₃)₂OO and two Criegee intermediates (<i>anti</i>- and <i>syn</i>-My-CIs) + acetone with branching ratios of 0.73, 0.23, and 0.04, respectively. The Criegee intermediates (CIs) are formed with high excitation, and they could either isomerize promptly or be thermalized to stabilized CIs (sCIs) at fractions of 0.39, 0.23, and 0.25 for (CH₃)₂COO*, <i>anti</i>-My-CI*, and <i>syn</i>-My-CI*. For stabilized My-CIs, <i>syn</i>-My-CI would undergo unimolecular H-migration to a vinyl hydroperoxide (VHP), which decomposes readily to OH radical and a vinoxy-type radical, while <i>anti</i>-My-CI would most likely react with water vapor or cyclize to a bicyclic compound when relative humidity is low. Reaction of My-CIs with SO₂ is important only for conditions of low temperatures (<273 K) and low relative humidity. The predicted yields of 0.73 and 0.27 for <b>4V4P</b> and acetone agree reasonably with previous experimental measurements

Additional file 1: of A Facile Method for Preparation of Cu2O-TiO2 NTA Heterojunction with Visible-Photocatalytic Activity

The experimental details of preparing the Cu2O-TiO2 samples and further characterization results of Raman spectra and XRD patterns are provided as the supplemental information to support the discussion. (DOCX 2387 kb

Unveiling the Anomalous Hall Response of the Magnetic Structure Changes in the Epitaxial MnBi₂Te₄ Films

Recently discovered as an intrinsic antiferromagnetic topological insulator, MnBi2Te4 has attracted tremendous research interest, as it provides an ideal platform to explore the interplay between topological and magnetic orders. MnBi2Te4 displays distinct exotic topological phases that are inextricably linked to the different magnetic structures of the material. In this study, we conducted electrical transport measurements and systematically investigated the anomalous Hall response of epitaxial MnBi2Te4 films when subjected to an external magnetic field sweep, revealing the different magnetic structures stemming from the interplay of applied fields and the material’s intrinsic antiferromagnetic (AFM) ordering. Our results demonstrate that the nonsquare anomalous Hall loop is a consequence of the distinct reversal processes within individual septuple layers. These findings shed light on the intricate magnetic structures in MnBi2Te4 and related materials, offering insights into understanding their transport properties and facilitating the implementation of AFM topological electronics

Genome-wide identification and characterization of microRNAs differentially expressed in fibers in a cotton phytochrome A1 RNAi line

<div><p>Cotton fiber is an important commodity throughout the world. Fiber property determines fiber quality and commercial values. Previous studies showed that silencing phytochrome A1 gene (<i>PHYA1</i>) by RNA interference in Upland cotton (<i>Gossypium hirsutum</i> L. cv. Coker 312) had generated <i>PHYA1</i> RNAi lines with simultaneous improvements in fiber quality (longer, stronger and finer fiber) and other key agronomic traits. Characterization of the altered molecular processes in these RNAi genotypes and its wild-type controls is a great interest to better understand the <i>PHYA1</i> RNAi phenotypes. In this study, a total of 77 conserved miRNAs belonging to 61 families were examined in a <i>PHYA1</i> RNAi line and its parental Coker 312 genotype by using multiplex sequencing. Of these miRNAs, seven (miR7503, miR7514, miR399c, miR399d, miR160, miR169b, and miR2950) were found to be differentially expressed in <i>PHYA1</i> RNAi cotton. The target genes of these differentially expressed miRNAs were involved in the metabolism and signaling pathways of phytohormones, which included Gibberellin, Auxin and Abscisic Acid. The expression of several MYB transcription factors was also affected by miRNAs in RNAi cotton. In addition, 35 novel miRNAs (novel miR1-novel miR35) were identified in fibers for the first time in this study. Target genes of vast majority of these novel miRNAs were also predicted. Of these, nine novel miRNAs (novel-miR1, 2, 16, 19, 26, 27, 28, 31 and 32) were targeted to cytochrome P450-like TATA box binding protein (TBP). The qRT-PCR confirmed expression levels of several differentially regulated miRNAs. Expression patterns of four miRNAs-targets pairs were also examined via RNA deep sequencing. Together, the results imply that the regulation of miRNA expression might confer to the phenotype of the <i>PHYA1</i> RNAi line(s) with improved fiber quality.</p></div

Fabrication of Heterostructured Metal Oxide/TiO₂ Nanotube Arrays Prepared via Thermal Decomposition and Crystallization

Heterostructured TiO₂ materials are of great importance in electronic and photochemical related applications. We report herein a simple, low-cost, and scalable fabrication of metal oxides heterostructured TiO₂ nanotube arrays (NTAs) through a combined strategy of thermal decomposition and crystallization. Various M_<i>x</i>O_<i>y</i>/TiO₂ heterostructured films (M = Zn, Ce, Cu, Cr...) were obtained by using TiO₂ NTAs as “nano-containers” as well as “nano-reactors”, while using M­(CH₃­COO)_<i>x</i> solutions as the precursors. SEM, XRD, EDS results demonstrated that Cu₂O/TiO₂ NTAs, ZnO/TiO₂ NTAs, Cr₂O₃/TiO₂ NTAs, and CeO₂/TiO₂ NTAs were successfully fabricated. Photocatalytic results revealed that the heterostructured M_<i>x</i>O_<i>y</i>/TiO₂ films could either enhance the UV photocatalytic activities or enable the visible light photocatalytic activities of the TiO₂ NTAs. This study provides a facile general approach to prepare M_<i>x</i>O_<i>y</i>/TiO₂ NTAs films, which could be very useful for environmental and energy areas

Distribution of mapped sequence reads.

<p>Distribution of mapped sequence reads.</p

Validation of expression patterns of differentially-expressed-known miRNAs in 10 DPA-fiber of <i>PHYA1</i>-RNAi line by qRT-PCR.

<p>The miRNA expression was represented as relative fold change 2^-ΔΔCT (ΔΔC_T = ΔC_{T RNAi} - ΔC_{T Coker 312}). The expression levels of miRNA were normalized by using U6 snRNA as a reference. Three biological replicates and three technical replicates were used for qRT-PCR analysis. The error bar represent the confidence limits. RF and CF denote fibers from RNAi and Coker 312 lines, respectively. MIR 169b was not detected in 10-DPA fiber by MIR Seq.</p

Trim reads statistics from raw data image file.

<p>Trim reads statistics from raw data image file.</p

Inverse correlation between the expression of four novel miRNAs and their target genes.

<p>(A) RNA Sequencing and qRT-PCR analysis of predicted target genes of four novel miRNAs in 10 DPA fiber; (B) miRNA Sequencing and qRT-PCR analysis of four novel miRNAs in 10 DPA fiber. Gene expression was represented as fold change 2^-ΔΔCT (ΔΔC_T = ΔC_{T RNAi} - ΔC_{T Coker 312}). The expression levels of the genes were normalized by <i>UBQ7</i> (Gen bank accession NO. DQ116441) and U6 snRNA as internal references for mRNAs and miRNAs, respectively. Three biological replicates and three technical replicates were included for qRT-PCR assays. The error bar represent the confidence limits.</p

Novel miRNAs identified in all libraries.

<p>Novel miRNAs identified in all libraries.</p