Surface-Induced Heterogeneity Analysis of an Alkanethiol Monolayer on Microcrystalline Copper Surface Using Sum Frequency Generation Imaging Microscopy

An octadecanethiol (ODT) self-assembled monolayer on microcrystalline copper is investigated by sum frequency generation (SFG) imaging microscopy and electron backscattering diffraction (EBSD). The strong SFG signal contrast across the domain boundary indicates the existence of grain structures on copper surface, which is further verified by EBSD measurements. The nonresonant contribution of SFG response shows anisotropy with respect to the in-plane rotation of the sample relative to the surface normal and varies in each crystal domain area. The resonant contribution of the monolayer, such as the amplitude ratio of CH₃-sym/CH₃-asym, is azimuthally nearly isotropic. Since the zzz tensor component of nonlinear susceptibility dominates, the resonant part of SFG spectra on the metal surface does not show any anisotropy. Further, a strong correlation between the local metal structures with the top monolayer packing behaviors is identified based on the statistical distribution analysis. Using the methyl group as an illustrative case, the variations in tilt angle of methyl group for different crystal grains, visualized in the SFG image, suggest that the underneath local grain structure contributes significantly to the overall monolayer packing behaviors measured on the macroscale

Grain Structures and Boundaries on Microcrystalline Copper Covered with an Octadecanethiol Monolayer Revealed by Sum Frequency Generation Microscopy

An octadecanethiol (ODT) self-assembled monolayer on microcrystalline copper was investigated by sum frequency generation (SFG) imaging microscopy. The crystal grain and grain boundaries of the copper surface were mapped in the SFG image based on the strong brightness contrast of the SFG signal across the boundary. Local SFG spectra reveal significant difference with each other as well as the average SFG spectra, indicating the heterogeneity of the copper surface resulting from copper grains with distinct crystallographic facets and orientations. It is demonstrated that the SFG signal of crystalline domain areas contains azimuthal anisotropy with respect to the plane of incidence. In addition, the statistical orientation analyses of amplitude ratio of CH₃-sym/CH₃-asym and corresponding contour maps imply that the orientation of ODT molecules is affected by the underlying copper

High-dose versus conventional-dose irradiation in cisplatin-based definitive concurrent chemoradiotherapy for esophageal cancer: a systematic review and pooled analysis

<div><p>We investigate whether high-dose (HD, ≥60 Gy) radiotherapy in definitive concurrent chemoradiotherapy (CCRT) based on cisplatin could yield benefits compared to conventional-dose (CD) CCRT. PubMed, Embase and Google Scholar were searched and data were pooled and analyzed for response rate, survival, failure patterns and toxicity. Results showed advantages in response rate, 5-year overall survival rate, local regional recurrence and distant failure rate compared to the CD arm with no difference in Grade ≥3 acute and late esophagitis, other toxicities were rare with moderate tolerance, subgroup analysis of squamous cell carcinoma also showed advantages for HD arm. We concluded that ≥60 Gy CCRT improved clinical outcomes compared to the CD arm, especially for esophageal squamous cell carcinoma. Our findings may provide a basis for future trials.</p></div

Relative <i>PxAdoR</i> mRNA level.

<p><b>(A) Effect of <i>PxAdoR</i> silencing by 500 ng/mL dsRNA feeding. (B) Effect of HEA feeding after silencing <i>PxAdoR</i>.</b> Analyzed sample were cDNAs that were reverse-transcribed from pooled RNA samples of 10 larvae. Bars represent the means ± standard deviations of technical replicates. *<i>P <</i> 0.05; **<i>P <</i> 0.001 (A) compared with the dsgfp group. (B) compared with the control.</p

cDNA sequence of <i>Plutella xylostella</i> Adenosine Receptor.

<p>The line box area indicates the open reading frame (ORF), which encodes protein of 440 amino acids. The start codon (ATG) and the stop codon (TGA) are highlighted in black. The sequence was deposited in the GenBank (Assession No.KR258794).</p

List of primers used in the study

<p>List of primers used in the study</p

Fabrication of Biocompatible, Luminescent Supramolecular Structures and Their Applications in the Detection of Dopamine

Supramolecular materials assembled by amide-functionalized surface active ionic liquid, <i>N</i>-dodecyl-<i>N</i>′-acetamido imidazolium bromide ([C₁₂ImCONH₂]­Br), and europium-containing polyoxometalates (Eu-POM) were fabricated in aqueous solution by a one-step method via ionic self-assembly strategy. The [C₁₂ImCONH₂]­Br/Eu-POM supramolecular structures exhibit favorable fluorescence properties and represent a 15-fold increase in quantum yield (∼13.68%) compared to Eu-POM. Besides, more fluorescence was quenched obviously with the increasing concentration of dopamine (DA) (within the range of 0–100 μM), based on which DA monitoring could be achieved. The detection limit was identified to be 0.1 μM. The supramolecular nanoparticles are highly specific for the detection of DA. In addition, the hybrid assemblies display not only low cytotoxicity but also excellent biocompatibility to MC3T3-E1 cells. As a result, as-prepared supramolecular materials with these superior properties show the promising application in some fields such as biochemistry and biomedical science

Cocrystallization of (μ‑S₂)^2– and (μ-S)^2– and Formation of an [η²‑S₃N(SiMe₃)₂] Ligand from Chalcogen Reduction by (N₂)^2– in a Bimetallic Yttrium Amide Complex

The reactivity of the (N₂)^2– complex {[(Me₃Si)₂N]₂Y­(THF)}₂(μ-η²:η²-N₂) (<b>1</b>) with sulfur and selenium has been studied to explore the special reductive chemistry of this complex and to expand the variety of bimetallic rare-earth amide complexes. Complex <b>1</b> reacts with elemental sulfur to form a mixture of compounds, <b>2</b>, that is the first example of cocrystallized complexes of (S₂)^2– and S^2– ligands. The crystals of <b>2</b> contain both the (μ-S₂)^2– complex {[(Me₃Si)₂N]₂Y­(THF)}₂(μ-η²:η²-S₂) (<b>3</b>) and the (μ-S)^2– complex {[(Me₃Si)₂N]₂Y­(THF)}₂(μ-S) (<b>4</b>), respectively. Modeling of the crystal data of <b>2</b> shows a 9:1 ratio of <b>3</b>:<b>4</b> in the crystals of <b>2</b> obtained from solutions that have 1:1 to 4:1 ratios of <b>3</b>/<b>4</b> by ¹H NMR spectroscopy. The addition of KC₈ to samples of <b>2</b> allows for the isolation of single crystals of <b>4</b>. The [S₃N­(SiMe₃)₂]⁻ ligand was isolated for the first time in crystals of [(Me₃Si)₂N]₂Y­[η²-S₃N­(SiMe₃)₂]­(THF) (<b>5</b>), obtained from the mother liquor of <b>2</b>. In contrast to the sulfur chemistry, the (μ-Se₂)^2– analogue of <b>3</b>, namely, {[(Me₃Si)₂N]₂Y­(THF)}₂(μ-η²:η²-Se₂) (<b>6</b>), can be cleanly synthesized in good yield by reacting <b>1</b>, with elemental selenium. The (μ-Se)^2– analogue of <b>4</b>, namely, {[(Me₃Si)₂N]₂Y­(THF)}₂(μ-Se) (<b>7</b>), was synthesized from Ph₃PSe

Expanding Yttrium Bis(trimethylsilylamide) Chemistry Through the Reaction Chemistry of (N₂)^2–, (N₂)^3–, and (NO)^2– Complexes

The reaction chemistry of the side-on bound (N₂)^2–, (N₂)^3–, and (NO)^2– complexes of the [(R₂N)₂Y]⁺ cation (R = SiMe₃), namely, [(R₂N)₂(THF)­Y]₂(<i>μ</i>-η²:η²-N₂), <b>1</b>, [(R₂N)₂(THF)­Y]₂(<i>μ</i>-η²:η²-N₂)­K, <b>2</b>, and [(R₂N)₂(THF)­Y]₂(<i>μ</i>-η²:η²-NO), <b>3</b>, with oxidizing agents has been explored to search for other (E₂)^<i>n</i>−, (E = N, O), species that can be stabilized by this cation. This has led to the first examples for the [(R₂N)₂Y]⁺ cation of two fundamental classes of [(monoanion)₂Ln]⁺ rare earth systems (Ln = Sc, Y, lanthanides), namely, oxide complexes and the tetraphenylborate salt. In addition, an unusually high yield reaction with dioxygen was found to give a peroxide complex that completes the (N₂)^2–, (NO)^2–, (O₂)^2– series with <b>1</b> and <b>3</b>. Specifically, the (<i><i>μ</i>-</i>O)^2– oxide-bridged bimetallic complex, [(R₂N)₂(THF)­Y}₂(<i><i>μ</i>-</i>O), <b>4</b>, is obtained as a byproduct from reactions of either the (N₂)^2– complex, <b>1</b>, or the (N₂)^3– complex, <b>2</b>, with NO, while the oxide formed from <b>2</b> with N₂O is a polymeric species incorporating potassium, {[(R₂N)₂Y]₂(<i><i>μ</i>-</i>O)₂K₂(<i><i>μ</i>-</i>C₇H₈)}_<i>n</i>, <b>5</b>. Reaction of <b>1</b> with 1 atm of O₂ generates the (O₂)^2– bridging side-on peroxide [(R₂N)₂(THF)­Y]₂(<i>μ</i>-η²:η²-O₂), <b>6</b>. The O–O bond in <b>6</b> is cleaved by KC₈ to provide an alternative synthetic route to <b>5</b>. Attempts to oxidize the (NO)^2– complex, <b>3</b>, with AgBPh₄ led to the isolation of the tetraphenylborate complex, [(R₂N)₂Y­(THF)₃]­[BPh₄], <b>7</b>, that was also synthesized from <b>1</b> and AgBPh₄. Oxidation of the (N₂)^2– complex, <b>1</b>, with the radical trap (2,2,6,6-tetramethylpiperidin-1-yl)­oxyl, TEMPO, generates the (TEMPO)⁻ anion complex, (R₂N)₂(THF)­Y­(η²-ONC₅H₆Me₄), <b>8</b>