Highly Selective and Sensitive Detection of Pb²⁺ in Aqueous Solution Using Tetra(4-pyridyl)porphyrin-Functionalized Thermosensitive Ionic Microgels

Tetra­(4-pyridyl)­porphyrin (TPyP)-functionalized thermosensitive ionic microgels (TPyP5-MGs) were synthesized by a two-step quaternization method. The obtained TPyP5-MGs have a hydrodynamic radius of about 189 nm with uniform size distribution and exhibit thermosensitive character. The TPyP5-MG microgel suspensions can optically respond to trace Pb²⁺ ions in aqueous solution with high sensitivity and selectivity over the interference of other 19 species of metal ions (Yb³⁺, Gd³⁺, Ce³⁺, La³⁺, Bi³⁺, Ba²⁺, Zn²⁺, Ni²⁺, Co²⁺, Mn²⁺, Cr³⁺, K⁺, Na⁺, Li⁺, Al³⁺, Cu²⁺, Ag⁺, Cd²⁺, and Fe³⁺) by using UV–visible spectroscopy. The sensitivity of TPyP5-MGs toward Pb²⁺ can be further improved by increasing the solution temperature. The limit of detection for TPyP5-MG microgel suspensions in the detection of Pb²⁺ in aqueous solution at 50 °C is about 25.2 nM, which can be further improved to be 5.9 nM by using the method of higher order derivative spectrophotometry and is much lower than the U. S. EPA standard for the safety limit of Pb²⁺ ions in drinking water. It is further demonstrated that the TPyP5-MG microgel suspensions have a potential application in the detection of Pb²⁺ in real world samples, which give consistent results with those obtained by elemental analysis

Thermosensitive Ionic Microgels via Surfactant-Free Emulsion Copolymerization and in Situ Quaternization Cross-Linking

A type of thermosensitive ionic microgel was successfully prepared via the simultaneous quaternized cross-linking reaction during the surfactant-free emulsion copolymerization of <i>N</i>-isopropylacrylamide (NIPAm) as the main monomer and 1-vinylimidazole or 4-vinylpyridine as the comonomer. 1,4-Dibromobutane and 1,6-dibromohexane were used as the halogenated compounds to quaternize the tertiary amine in the comonomer, leading to the formation of a cross-linking network and thermosensitive ionic microgels. The sizes, morphologies, and properties of the obtained ionic microgels were systematically investigated by using transmission electron microscopy (TEM), dynamic and static light scattering (DLS and SLS), electrophoretic light scattering (ELS), thermogravimetric analyses (TGA), and UV–visible spectroscopy. The obtained ionic microgels were spherical in shape with narrow size distribution. These ionic microgels exhibited thermosensitive behavior and a unique feature of poly­(ionic liquid) in aqueous solutions, of which the counteranions of the microgels could be changed by anion exchange reaction with BF₄K or lithium trifluoromethyl sulfonate (PFM-Li). After the anion exchange reaction, the ionic microgels were stable in aqueous solution and could be well dispersed in the solvents with different polarities, depending on the type of counteranion. The sizes and thermosensitive behavior of the ionic microgels could be well tuned by controlling the quaternization extent, the type of comonomer, halogenated compounds, and counteranions. The ionic microgels showed superior swelling properties in aqueous solution. Furthermore, these ionic microgels also showed capabilities to encapsulate and release the anionic dyes, like methyl orange, in aqueous solutions

Poly(<i>N</i>‑isopropylacrylamide-<i>co</i>-1-vinyl-3-alkylimidazolium bromide) Microgels with Internal Nanophase-Separated Structures

Microgels with internal nanophase-separated structures were fabricated by surfactant-free emulsion copolymerization of <i>N</i>-isopropylacrylamide (NIPAm) and ionic liquid comonomers, namely, 1-vinyl-3-alkylimidazolium bromide (VIM<i>n</i>Br) with various lengths <i>n</i> of long alkyl side chain, in an aqueous solution at 70 °C using <i>N</i>,<i>N</i>′-methylenebisacrylamide as the cross-linker. Combined techniques of transmission electron microscopy, dynamic and static light-scattering, differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), small-angle X-ray scattering (SAXS), and polarized optical microscopy were employed to systematically investigate the sizes, morphologies, and properties of the obtained microgels as well as the microstructures and phase transition of nanophases inside the microgels. The obtained P­(NIPAm/VIM<i>n</i>Br) microgels are spherical with narrow size distributions, and the nanophases have a radius of about 8–12 nm and are randomly distributed inside the microgels. The cooperative competition of the hydrophilic quaternary vinylimidazole moieties and hydrophobic long alkyl side chains determines the thermal sensitive behavior of the P­(NIPAm/VIM<i>n</i>Br) microgels. DSC and WAXD results reveal that the nanophases consist of the ordered alkyl side chains with a layered crystalline structure at low temperature, which exhibit a low melting temperature and a broad melting transition. SAXS results further show that the nanophases form a layered liquid crystalline structure at high temperature for the microgel suspensions and freeze-dried microgels

Additional file 1 of The impact of different endometrial preparation protocols on obstetric and neonatal complications in frozen-thawed embryo transfer: a retrospective cohort study of 3,458 singleton deliveries

Additional file 1: Table S1. Definition of obstetric and neonatal complications. Table S2. Univariate and multivariate analysis of predictor variables for HDP. Table S3. Univariate and multivariate analysis of predictor variables for LGA. Table S4. Univariate and multivariate analysis of predictor variables for SGA. Table S5. Univariate and multivariate analysis of predictor variables for preterm delivery

Polystyrene-<i>block</i>-poly(ethylene oxide) Reverse Micelles and Their Temperature-Driven Morphological Transitions in Organic Solvents

Polystyrene-<i>block</i>-poly(ethylene oxide) Reverse Micelles and Their Temperature-Driven Morphological Transitions in Organic Solvent

Coagulation factor FVII fine-tunes hepatic steatosis by blocking AKT-CD36-mediated fatty acid uptake

NAFLD is considered as a risk factor for cardiovascular and cerebrovascular disease owing to its close association with coagulant disturbances. However, the precise biological functions and mechanisms that connect coagulation factors to NAFLD pathology remain inadequately understood. Herein, with unbiased bioinformatic analyses followed by functional test, we demonstrate that hepatic expression of coagulation factor FVII decreases in patients and mice with NAFLD/NASH. By employing adenovirus-mediated F7-knockdown and hepatocyte-specific F7-knockout mouse models, our mechanistic investigations unveil a non-coagulant function of hepatic FVII in mitigating lipid accumulation and lipotoxicity. This protective effect is achieved through the suppression of fatty acid (FA) uptake, orchestrated via the AKT-CD36 pathway. Interestingly, we observed that intracellular FVII directly interacts with AKT and PP2A, thereby promoting their association and triggering the dephosphorylation of AKT. Therapeutic intervention through adenovirus-mediated liver-specific overexpression of FVII has resulted in noteworthy improvements in liver steatosis, inflammation, injury and fibrosis in severely afflicted NAFLD mice. In conclusion, our findings highlight coagulation factor FVII as a critical regulator of hepatic steatosis and a potential target for the treatment of NAFLD and NASH.</p