Porous Poly(ionic Liquid) Membrane with Metal Nanoparticle Gradient: A Smart Actuator for Visualizing Chemical Reactions.

Poly(ionic liquid) (PIL)-based porous membranes are extensively investigated as soft polymer actuators. While PILs have shown significant advancements in membrane fabrication and stabilization of metal nanoparticles (MNPs), research on integrating MNPs into porous membranes to achieve actuation behavior under multiple stimuli is limited. Herein, this work presents a new paradigm for designing a porous PIL-polyacrylic acid (PAA) membrane with a distinct MNP gradient via a top-bottom diffusion approach involving a metal salt precursor solution and NaBH4 as a reducing agent. The strong binding sites provided by PILs, combined with the gradient distribution of -COO- groups across the membrane cross-section, play a significant role in controlling the MNPs' gradient distribution. Interestingly, the MNPs within the membrane display excellent catalytic activity in exothermic reactions such as H2O2 decomposition, dissipating uneven heat that quickly permeates the membrane network. This induces asymmetrical swelling of polymer chains, resulting in rapid membrane bending. Furthermore, such MNP-loaded membrane could serve as a portable test paper for visually monitoring H2O2. This advancement paves the way for the development of intricate smart actuation materials and expands their practical applications in various real-life scenarios.

Hierarchically Porous Poly(ionic liquid) - Organic Cage Composite Membrane for Efficient Iodine Capture.

The effective capture of iodine with high volatility and poisonousness is significant for reprocessing the spent nuclear fuel. In this article, we report a hierarchically porous poly(ionic liquid)-organic cage composite membrane (PIL@CC3) possessing a gradient content distribution of CC3 cage crystals throughout the membrane to capture iodine vapor. The introduction of microporous CC3 can significantly enhance the uptake capacity of iodine up to 980 mg g-1 , which is superior to that of a pristine PIL membrane carrying large meso- and macropores (99 mg g-1 ), and CC3 crystalline powder (662 mg g-1 ). Such enhanced performance benefits from the micro-meso-macroporous structure of the PIL@CC3 membrane in which the large meso- and macropores facilitate the mass transfer of iodine molecules from the external environment into the surface of the CC3 crystal, followed by diffusion of iodine molecules from the CC3 surface into the interior and exterior pores of the CC3 crystal. In addition, the asymmetric distribution of CC3 crystals across the PIL@CC3 membrane also displays its advantage in intercepting trace iodine, revealing its great potential for practical application. This study provides an idea for constructing hierarchically porous membrane composites for the removal of toxic vapors.

Continuous and Rapid Synthesis of UiO-67 by Electrochemical Methods for the Electrochemical Detection of Hydroquinone.

Continuous and rapid synthesis of UiO-67 under mild conditions has been achieved by electrochemical methods for the first time. In the reaction system, a zirconium sheet was utilized as electrodes and a metal source for the assembly of UiO-67. High-crystalline UiO-67 with a regular tetrahedral morphology of around 1 µm was obtained within 1.5 h under the optimized solvent composition, voltage, and temperature conditions. This electrochemical synthetic method of UiO-67 in our work overcomes the shortcomings of high temperature and pressure of a traditional solvothermal method, which proposes new ideas for the large-scale and rapid synthesis of UiO-67. The UiO-67 synthesized by an electrochemical method was prepared as a UiO-67-carbon paste electrode (CPE), which exhibited a linear response to hydroquinone (HQ) in the range of 5-300 µM with a detection limit of 3.6 × 10-9 M (S/N = 3), for the electrochemical detection of HQ. It was confirmed that UiO-67-CPE possessed excellent reusability and antiinterference ability for the detection of HQ, and its detection ability even did not change after standing for 3 months. We further tried to apply UiO-67-CPE to the practical determination of HQ in tap water and river water samples, and the results proved that the recovery rate is 97.9-104.7% in real samples.

Rapid and Low-Cost Electrochemical Synthesis of UiO-66-NH2 with Enhanced Fluorescence Detection Performance.

Rapid and low-cost synthesis of metal-organic frameworks (MOFs) are very meaningful for their future practical application. In the present study, a Zr-based ultrastable MOF, UiO-66-NH2, was successfully synthesized by electrochemical method using metal Zr as the metal source at room temperature and atmospheric pressure. The effects of the reaction conditions, including the ratio of solvent (electrolyte), the applied voltage and different reaction time, on the crystallinity, morphology, and synthesis rate of the product were fully investigated. The results confirm that electrochemically synthesized UiO-66-NH2 under the optimized condition possesses apparent merits such as high crystallinity, uniform morphology and high porosity. Moreover, the electrochemical synthesis method of UiO-66-NH2 is promising for the large-scale and economical synthesis of nanoscale product to gramme degree. Interestingly, the resulting UiO-66-NH2 synthesized by this electrochemical method exhibits more excellent performance for the fluorescence detection of Fe3+ ions in water (detection limit of 10-8 mol/L) than that of the material prepared by solvothermal method.

A robust Zn(ii)/Na(i)-MOF decorated with [(OAc)2(H2O)2]n2n- anions for the luminescence sensing of copper ions based on the inner filter effect.

Based on the inner filter effect, a luminescent Zn(ii)/Na(i) metal-organic framework (MOF) {[Zn2Na(L)(HL)2(H2O)2][OAc]·2H2O}n (1, H2L = 5-methyl-1,3-benzenedicarboxylic acid) with excellent stability was constructed for the fluorescence detection of Cu2+ ions. MOF 1 holds a 3D cationic framework in which [(OAc)2(H2O)2]n2n- anions are embedded into its 1D channels. Abundant hydrogen-bonding and π-π interactions in the MOF facilitate electron transfer from ligand-to-metal, resulting in a good luminescence peak at 412 nm and an efficient fluorescence quenching of MOF 1 in the presence of Cu2+ ions, due to the inner filter effect. The interactions between the Cu2+ ions and the OAc- anion in the channel endowed the Cu2+ ions with facile access to be adsorbed, and afforded the selective quenching of fluorescence. The MOF particles are well dispersed in water and the Cu2+ ions are pre-concentrated by adsorption, thus facilitating the determination of Cu2+ ions with a detection limit down to 0.65 µM. Our work thus paves a way for developing MOFs as an appealing platform to construct materials for environmental applications.

GnRH antagonist cetrorelix inhibits mitochondria-dependent apoptosis triggered by chemotherapy in granulosa cells of rats.

OBJECTIVE: Exposure to chemotherapy causes various adverse effects on the ovaries including premature ovarian failure and infertility. GnRH antagonist cetrorelix could reverse the ovarian damage during chemotherapy, but the mechanism remains unclear. The objectives of this study were to examine the role of the cetrorelix for prevention of mitochondria-dependent apoptosis in granulosa cells of rats during the treatment with cyclophosphamide(Cy), if the mitochondria-dependent apoptotic process was involved. METHODS: Female SD rats were injected with cetrorelix before and after administration of saline, or Cy. Main outcome measures were the apoptotic indexes, serum hormones, ultrastructure of granulosa cells, mitochondrial membrane potential, the kinetics of cytochrome c (Cyt-c) processing in cells, and apoptotic markers. RESULTS: The ovarian apoptotic indexes as shown by TUNEL assay were reduced by cetrorelix pretreatment and the rats regained normal hormonal profile. The ultrastructure and JC-1 fluorescence intensity assessments showed cetrorelix pretreatment inhibited mitochondrial dysfunction in granulosa cells induced by chemotherapy. Western blot analysis showed that cetrorelix suppressed the release of Cyt-c from mitochondria to cytoplasm. Meanwhile, cetrorelix pretreatment expressed less Bax, caspase-3 and Cyt-c in granulosa cells compared with chemotherapy alone. CONCLUSION: Cetrorelix could reduce the apoptosis in granulosa cells through inhibiting mitochondria-dependent apoptosis triggered by chemotherapy.

The GnRH antagonist reduces chemotherapy-induced ovarian damage in rats by suppressing the apoptosis.

OBJECTIVE: GnRH antagonist cetrorelix could reserve the ovarian follicles during chemotherapy, but the mechanism remains unclear. The objectives of this study were to examine the overall effect of cetrorelix against ovarian failure and to define if the apoptotic process was involved. METHODS: Female SD rats were injected with cetrorelix before and after administration of saline, or cyclophosphamide (Cy), or oral etoposide (VP). Main outcome measures were the number of ovarian follicles, serum hormones, ovary histology and apoptotic markers. RESULTS: The females exposed to Cy or VP had reduced body and ovary weights, which could be restored by cetrorelix pretreatment. Single cetrorelix treatment could increase the number of primordial follicles, but reduce the number of growing and mature follicles. As a consequence, the ovaries exposed to cetrorelix prior to Cy or VP showed significantly higher numbers of follicles at all developing stages than those exposed to Cy or VP alone. Meanwhile, the ovarian apoptotic indexes as shown by TUNEL assay were reduced by cetrorelix pretreatment and the ovary expressed less caspases-3 and more Bcl-2 compared with chemotherapy alone. Moreover, the rats regained normal hormonal profile after cetrorelix pretreatment without any alterations in ovarian expression of estrogen receptor (ER)alpha, ERbeta, or progesterone receptor (PR). CONCLUSION: Cetrorelix could reduce the chemotherapy-induced ovarian damage through regulating the expression of Bcl-2 and caspases-3 in the ovary, without any expressional alterations of nuclear receptors, suggesting the apoptosis pathway involved.