Volumetric and Fluorescence Studies of Aqueous Solutions Containing <i>n</i>-Octylamine, Cetyltrimethylammonium Bromide, and Salt

Densities of aqueous solutions containing n-octylamine, 0.0500 mol kg-1 cetyltrimethylammonium bromide (CTAB), and sodium chloride/potassium chloride have been determined and used to derive the standard partial molar volumes of n-octylamine at 298.15 K. The effect of the additives (sodium chloride, potassium chloride, and n-octylamine) on the polarities of the micelles have also been investigated by static fluorescence spectra using pyrene as a probe at 298.15 K. It has been observed that the postmicellar transitions of sphere-to-rodlike, as indicated by the amplified changes in the standard partial molar volumes of n-octylamine, are affected strongly by the addition of an electrolyte. The effect of sodium chloride on the postmicellar transition of CTAB is much weaker than potassium chloride. Polarity of the interior of the mixed micelle and therefore the solubilized site of pyrene vary with molality of the additives. This is considered to be caused by the difference in chemical structure and hydrophobic nature of the mixed micelle. The results of fluorescence spectra reveal the possible microscopic causes for the effect of additives on the postmicellar transition of CTAB

Additional file 1 of Effect of initial COVID-19 outbreak during first trimester on pregnancy outcome in Wuxi, China

Additional file 1

DataSheet_1_Responses of bacterioplankton, particle- and colony-attached bacterial communities to Phaeocystis globosa blooms in Mirs Bay, China.docx

Microalgae blooms are a frequent occurrence in coastal waters worldwide. It is reasonable to assume that these blooms have various influences on bacterial communities, which in turn may affect the development and dissipation of the bloom. However, the bacterial community characteristics, particularly of attached bacteria, associated with microalgae blooms remain unclear. In this study, we investigated the community profiles of bacteria using high-throughput sequencing during a Phaeocystis globosa bloom in Mirs Bay, southern China, in January 2021. Bacteria living in three habitats, i.e., bacterioplankton, particle-attached bacteria, and colony-attached bacteria, were studied from the exponential growth phase to the decline growth phase of the bloom. Distinct variations in bacterial community composition existed among the three habitats. Bacteroidota, Proteobacteria, and Cyanobacteria were the dominant phyla of bacterioplankton, particle–attached bacteria, and colony-attached bacteria, respectively. Richness and diversity were significantly highest (p < 0.01) in particle-attached bacteria, followed by bacterioplankton, and lowest in colony-attached bacteria. The community diversities of bacterioplankton and particle-attached bacteria decreased significantly (p < 0.05) as the bloom shifted from the exponential to the decline phase. During the decline growth phase of the bloom, Bacteroidota and Verrucomicrobiota were the dominant remarkably abundant bacteria in the bacterioplankton community, whereas Verrucomicrobiota was dominant in the particle-attached bacteria community. No significant difference was observed in the colony-attached bacterial community between the exponential and decline phases of the P. globosa bloom owing to their complex network. The results of this study suggest that P. globose bloom has a profound impact on marine bacteria, particularly species that can decompose organic matter, which could play a crucial role in the dissipation of algal blooms.</p

Luminescent Zn(II) Coordination Polymers for Highly Selective Sensing of Cr(III) and Cr(VI) in Water

Three photoluminescent zinc coordination polymers (CPs), {[Zn₂(tpeb)₂(2,5-tdc)­(2,5-Htdc)₂]·2H₂O}_<i>n</i> (<b>1</b>), {[Zn₂(tpeb)₂(1,4-ndc)­(1,4-Hndc)₂]·2.6H₂O}_<i>n</i> (<b>2</b>), and {[Zn₂(tpeb)₂(2,3-ndc)₂]·H₂O}_<i>n</i> (<b>3</b>) (tpeb = 1,3,5-tri-4-pyridyl-1,2-ethenylbenzene, 2,5-tdc = 2,5-thiophenedicarboxylic acid, 1,4-ndc = 1,4-naphthalenedicarboxylic acid, and 2,3-ndc = 2,3-naphthalenedicarboxylic acid) were prepared from reactions of Zn­(NO₃)₂·6H₂O with tpeb and 2,5-H₂tdc, 1,4-H₂ndc, or 2,3-H₂ndc under solvothermal conditions. Compound <b>1</b> has a two-dimensional (2D) grid-like network formed from bridging 1D [Zn­(tpeb)]_<i>n</i> chains via 2,5-tdc dianions. <b>2</b> and <b>3</b> possess similar one-dimensional (1D) double-chain structures derived from bridging the [Zn­(tpeb)]_<i>n</i> chains via pairs of 1,4-ndc or 2,3-ndc ligands. The solid-state, visible emission by <b>1</b>–<b>3</b> was quenched by Cr³⁺, CrO₄^2–, and Cr₂O₇^2– ions in water with detection limits by the most responsive complex <b>3</b> of 0.88 ppb for Cr³⁺ and 2.623 ppb for Cr₂O₇^2– (pH = 3) or 1.734 ppb for CrO₄^2– (pH = 12). These values are well below the permissible limits set by the USEPA and European Union and the lowest so far reported for any bi/trifunctional CPs sensors. The mechanism of Cr³⁺ luminescence quenching involves irreversible coordination to free pyridyl sites in the CP framework, while the Cr⁶⁺ quenching involves reversible overlap of the absorption bands of the analytes with those of the excitation and/or emission bands for <b>3</b>

Three Zinc(II) Coordination Polymers Based on Tetrakis(4-pyridyl)cyclobutane and Naphthalenedicarboxylate Linkers: Solvothermal Syntheses, Structures, and Photocatalytic Properties

Solvothermal reactions of Zn­(NO₃)₂ with tetrakis­(4-pyridyl)­cyclobutane (tpcb) and 1,4-naphthalenedicarboxylic acid (1,4-H₂ndc) and 2,3-naphthalenedicarboxylic acid (2,3-H₂ndc) in different solvents led to the formation of three polydimensional coordination polymers {[Zn₂(H₂O)­(1,4-ndc)₂(tpcb)]}_<i>n</i> (<b>1</b>), {[Zn­(1,4-ndc)­(tpcb)_0.5]}_<i>n</i> (<b>2</b>), and {[Zn₂(H₂O)­(2,3-ndc)₂(tpcb)]}<i>_n</i> (<b>3</b>). Compounds <b>1</b>–<b>3</b> were characterized by elemental analysis, IR, powder X-ray diffraction (PXRD), and single crystal X-ray diffraction. Compound <b>1</b> is a three-dimensional (3D) (3,3)-connected net with a (10·12²)·(10²·12) Schläfli symbol. Compound <b>2</b> holds a 2-fold interpenetrating 3D framework with a (4²·6²·7²)·(4·6²·7³) Schläfli symbol, which shows hexagonal-prism-like one-dimensional channels. Compound <b>3</b> shows a two-dimensional (3,8)-connected network. The solid state luminescent, optical, and thermal stability properties of <b>1</b>–<b>3</b> at ambient temperature were also investigated. A comparative study on their photocatalytic activity toward the degradation of methyl orange and methyl blue in polluted water was explored. The results provided some interesting insights into solvent effects on the structures of zinc­(II) coordination polymers and their photocatalytic applications

Three Zinc(II) Coordination Polymers Based on Tetrakis(4-pyridyl)cyclobutane and Naphthalenedicarboxylate Linkers: Solvothermal Syntheses, Structures, and Photocatalytic Properties

Solvothermal reactions of Zn­(NO₃)₂ with tetrakis­(4-pyridyl)­cyclobutane (tpcb) and 1,4-naphthalenedicarboxylic acid (1,4-H₂ndc) and 2,3-naphthalenedicarboxylic acid (2,3-H₂ndc) in different solvents led to the formation of three polydimensional coordination polymers {[Zn₂(H₂O)­(1,4-ndc)₂(tpcb)]}_<i>n</i> (<b>1</b>), {[Zn­(1,4-ndc)­(tpcb)_0.5]}_<i>n</i> (<b>2</b>), and {[Zn₂(H₂O)­(2,3-ndc)₂(tpcb)]}<i>_n</i> (<b>3</b>). Compounds <b>1</b>–<b>3</b> were characterized by elemental analysis, IR, powder X-ray diffraction (PXRD), and single crystal X-ray diffraction. Compound <b>1</b> is a three-dimensional (3D) (3,3)-connected net with a (10·12²)·(10²·12) Schläfli symbol. Compound <b>2</b> holds a 2-fold interpenetrating 3D framework with a (4²·6²·7²)·(4·6²·7³) Schläfli symbol, which shows hexagonal-prism-like one-dimensional channels. Compound <b>3</b> shows a two-dimensional (3,8)-connected network. The solid state luminescent, optical, and thermal stability properties of <b>1</b>–<b>3</b> at ambient temperature were also investigated. A comparative study on their photocatalytic activity toward the degradation of methyl orange and methyl blue in polluted water was explored. The results provided some interesting insights into solvent effects on the structures of zinc­(II) coordination polymers and their photocatalytic applications

Image1_Fangji Dihuang formulation ameliorated DNCB-induced atopic dermatitis-like skin lesions by IL-17 signaling pathway: integrating network analysis and experimental validation.tif

Background: The Fangji Dihuang formulation (FJDHF) is a widely recognized Traditional Chinese Medicine (TCM) formula that consists of five plant drugs: Stephaniae Tetrandrae Radix, Cinnamomi Ramulus, Rehmanniae Radix, Saposhnikoviae Radix, and Glycyrrhiza Urensis Fisch. This formulation has been known to exhibit clinical therapeutic effects in the treatment of inflammatory skin diseases. However, there is a lack of pharmacological research on its anti-atopic dermatitis (AD) activity.Methods: To investigate the potential anti-AD activity of FJDHF, DNCB was used to induce AD-like skin inflammation in the back of mice. Following successful modeling, the mice were administered FJDHF orally. The extent of the inflammatory skin lesions was recorded at day 4, 7, 14 and 28. UHPLC-Q-Exactive Orbitrap MS was used to identify and match the compounds present in FJDHF with ITCM, TCMIP and TCMSID. In silico predictions of potential target proteins of the identified compounds were obtained from SwishTargetPrediction, ITCM and TargetNet databases. AD-related genes were identified from GSE32924 data set, and FJDHF anti-AD hub genes were identified by MCODE algorithm. ClueGo enrichment analysis was employed to identify the core pathway of FJDHF’s anti-AD effect. To further investigate the anti-AD effect of FJDHF, single-cell RNA sequencing data set (GSE148196) from AD patients was analyzed to determine the target cells and signaling pathways of FJDHF in AD. Finally, rt-PCR, flow cytometry, and mouse back skin RNA sequencing were utilized to validate our findings.Results: FJDHF was found to be effective in improving the degree of the AD-like lesions in the mice. Network pharmacological analysis revealed the core pathway of FJDHF to be the IL-17 signaling pathway, which is interactively associated with cytokines. Single-cell RNA sequencing analysis suggested that FJDHF may play an anti-AD role by influencing dendritic cells. Flow cytometry and rt-PCR results showed that FJDHF can reduce the influence of AD sample of IL-4, IFN-γ and the expression of IL-17. The RNA sequencing of mouse back skin also confirmed our conclusion.Conclusion: FJDHF may inhibit DNCB-induced AD-like skin inflammation in mice by inhibiting the IL-17 signaling pathway. Thus, FJDHF can be considered as a potential therapeutic agent for AD.</p

Ordering of Gold Nanorods in Confined Spaces by Directed Assembly

This paper describes an effective approach to order gold nanorods (NRs) within cylindrically confined microdomains of block copolymer- (BCP-) based supramolecular assemblies. Individual BCP micelles encapsulated with well-ordered NRs can be obtained by disassembling the supramolecular structures. The mismatch of binary polymer brushes with different lengths on the surface of the NRs was used to effectively improve the dispersion of the NRs within polymer matrix, due to enhanced wetting of the brushes by surrounding mismatch polymers. This enables us to quantitatively explore the location and orientation of the NRs within confined geometries. By varying the content of NRs, the aspect ratio of the NRs, or the diameter of the cylindrical BCP micelles, the orientation of the NRs within micelles can be tuned to form one-dimensional nanostrings with end-to-end organization of NRs along the micelles or with side-by-side twisted arrangement of NRs perpendicular to the micelles. UV–vis spectroscopy measurements and finite-difference time-domain (FDTD) calculations confirm that our approach provides a simple yet versatile route to tune the optical properties of the hybrid micelles by controlling the ordering of the NRs. This work provides guidelines for dispersing other functional anisotropic NPs, and lays groundwork for the fabrication of optical and electronic devices