Tetraphenylethene-based mononuclear aggregation-induced emission (AIE)-active mechanofluorochromism gold(I) complexes with different auxiliary ligands.

In this study, a series of tetraphenylethene-containing gold(I) complexes with different auxiliary ligands have been synthesized. These complexes were characterized using a variety of techniques including nuclear magnetic resonance spectroscopy, mass spectrometry, and single crystal X-ray diffraction. Their aggregation-induced emission (AIE) behaviors were investigated through ultraviolet/visible and photoluminescence spectrum analyses, and dynamic light scattering measurements. Meanwhile, their mechanofluorochromic properties were also studied via solid-state photoluminescence spectroscopy. Intriguingly, all these mononuclear gold(I) molecules functionalized by tetraphenylethene group demonstrated AIE phenomena. Furthermore, five gold(I) complexes possessing diverse auxiliary ligands exhibited distinct fluorescence changes in response to mechanical grinding. For luminogens 2-5, their solids showed reversible mechanofluorochromic behaviors triggered by the mutual transformation of crystalline and amorphous states, while for luminogen 1, blue-green-cyan three-color solid fluorescence conversion was realized by sequential mechanical grinding and solvent fumigation. Based on this stimuli-responsive tricolored fluorescence feature of 1, an information encryption system was successfully constructed.

High-performance composite elastomers with abundant heterostructures for enhanced electromagnetic wave absorption with ultrabroad bandwidth.

Two-dimensional (2D) MXene has attracted vast attention in electromagnetic wave absorption (EWA), but there remains a contradiction between maintaining impedance matching and enhancing dielectric loss. Herein, the multi-scale architectures of ecoflex/2D MXene (Ti3C2Tx)@zero-dimensional CoNi sphere@one-dimensional carbon nanotube composite elastomers were successfully constructed by simple liquid-phase reduction and thermo-curing method. The binding between the hybrids as fillers and ecoflex as a matrix greatly enhanced the EWA capability of the obtained composite elastomer and improved its mechanical properties. Owing to its good impedance matching, abundant heterostructures, and synergistic electrical and magnetic losses, this elastomer exhibited an excellent minimum reflection loss of -67 dB at 9.46 GHz under a thickness of 2.98 mm. In addition, its ultrabroad effective absorption bandwidth reached 6.07 GHz. This achievement will pave the way for the exploitation of multi-dimensional heterostructures as high-performance electromagnetic absorbers with superior EWA ability.

Protocatechuic acid alleviates polycystic ovary syndrome symptoms in mice by PI3K signaling in granulosa cells to relieve ROS pressure and apoptosis.

BACKGROUND: Polycystic ovary syndrome (PCOS) is a complicated gynecological endocrine disease that occurs in women of childbearing age. Protocatechuic acid is a phenol-rich compound derived from herbs and owns vital functions in numerous diseases. Howbeit, protocatechuic acid's impact on PCOS is unknown. METHODS: A combination of in vivo and in vitro models was examined in this study. C57BL/6 mice were injected subcutaneously daily with dehydroepiandrosterone to establish a PCOS mouse model, and protocatechuic acid was intraperitoneally injected into PCOS mice. Granulosa cells of PCOS ovaries were also isolated. The function of protocatechuic acid was appraised using enzyme-linked immunosorbent assay, hematoxylin-eosin staining, reactive oxygen species (ROS) and LC3 levels analysis, flow cytometry, quantitative real-time PCR, and western blot. Meanwhile, the mechanism of protocatechuic acid was assessed with a series of molecular experiments. RESULTS: Protocatechuic acid owned no apparent toxic effect on mice. Functionally, protocatechuic acid owned a function of mitigating PCOS in vivo. Meanwhile, protocatechuic acid repressed ROS, autophagy, and apoptosis of PCOS ovarian granulosa cells in vitro. Mechanistically, rescue assays elucidated that the protective function of protocatechuic acid against PCOS was interrelated to the activation of the PI3K/AKT/mTOR axis. CONCLUSION: Protocatechuic acid alleviated PCOS symptoms in mice through PI3K signaling in granulosa cells to reduce ROS levels and apoptosis.

Kinetics and mechanism of Thallium(I) oxidation by Permanganate: Role of bromide.

The oxidation of thallium(I) (Tl (I)) to Tl (III) is referred to as an efficient means for Tl removal. Bromide (Br‾) inevitably occurs in nearly all water sources at concentrations of 0.01-67 mg/L (0.14-960 µM). The effect of Br‾ remains largely unclear but likely of critical importance on the redox fate and thus the removal potential of Tl (I) during typical oxidation treatment processes. Here, we investigate the kinetics and tackle the mechanism of Tl (I) oxidation by permanganate (KMnO4) under the influence of Br‾. The results demonstrated that Br‾ at environmental levels exhibited significant catalytic effect on Tl (I) oxidation kinetics by KMnO4 at acidic pH of 4.0-7.0, while no significant effect of Br‾ was observed for Tl(I) oxidation under alkaline conditions of pH 8.0 and 9.0. It was found that the enhanced oxidation kinetics under acidic conditions was driven by the combined effect of and autocatalysis mediated by MnO2 and a fast oxidation kinetics served by in-situ formed bromine species. Through quantifying the relative contributions of those bromine species to the homogenous oxidation of Tl(I), HOBr, Br2 and Br2O were found to play roles in catalyzing the oxidation of Tl(I) by KMnO4. The results discussed herein highlight the critical role of Br‾ on the Tl(I) complex oxidation process by KMnO4 and may have implications for evaluating the redox cycle and removal potential of Tl in bromide-containing water treatment.

Kinetics of Thallium(I) Oxidation by Free Chlorine in Bromide-Containing Waters: Insights into the Reactivity with Bromine Species.

The oxidation of thallium [Tl(I)] to Tl(III) by chlorine (HOCl) is an important process changing its removal performance in water treatment. However, the role of bromide (Br-), a common constituent in natural water, in the oxidation behavior of Tl(I) during chlorination remains unknown. Our results demonstrated that Br- was cycled and acted as a catalyst to enhance the kinetics of Tl(I) oxidation by HOCl over the pH range of 5.0-9.5. Different Tl(I) species (i.e., Tl+ and TlOH(aq)) and reactive bromine species (i.e., HOBr/BrO-, BrCl, Br2O, and BrOCl) were kinetically relevant to the enhanced oxidation of Tl(I). The oxidation by free bromine species became the dominant pathway even at a low Br- level of 50 µg/L for a chlorine dose of 2 mg of Cl2/L. It was found that the reactions of Tl+/BrCl, Tl+/BrOCl, and TlOH(aq)/HOBr dominated the kinetics of Tl(I) oxidation at pH < 6.0, pH 6.0-8.0, and pH > 8.0, respectively. The species-specific rate constants for Tl+ reacting with individual bromine species were determined and decreased in the order: BrCl > Br2 > BrOCl > Br2O > HOBr. Overall, the presented results refine our knowledge regarding the species-specific reactivity of TI(I) with bromine species and will be useful for further prediction of thallium mobility in chlorinated waters containing bromide.

Transport of Tl(I) in water-saturated porous media: Role of carbonate, phosphate and macromolecular organic matter.

Understanding the transport behaviors of thallium (Tl) in porous media is of considerable interest for both natural soils and artificial filtration removal of Tl. In this context, the transport behaviors of Tl(I) in water-saturated sand columns under different conditions were systematically investigated. It was found that, in addition to the effects of pH and ionic strength (IS), the transport of Tl(I) depended on the carbonate, phosphate and macromolecular organic matter as well. Tl(I) broken the columns more difficultly under higher pH and lower IS conditions. Moreover, the adsorption of carbonate and phosphate on sand surfaces may increase the retention of Tl(I) in columns. As for macromolecular organic matter, humic acid (HA) facilitated Tl(I) transport, especially under neutral and alkaline conditions (7.0 and 9.8), which was possibly associated with Tl-complexes formation and competed adsorption between Tl(I) and HA. However, bovine serum albumin (BSA) impeded Tl(I) transport for the reason that deposited BSA might provide more adsorption sites for Tl(I), though Tl(I) had a slight effect on BSA transport. In order to evaluate the mechanisms of transport, a dual-sites non-equilibrium model was applied to fit the breakthrough curves of Tl(I). Retardation factor (R) values of individual Tl(I) transport from model calculations were found to be higher than that of Tl(I) transport with HA and lower than that of Tl(I) transport with BSA. The fraction of instantaneous sorption sites (ß) was found to decrease with increasing pH, implying nonequilibrium sorption is a main sorption mechanism of Tl(I) with pH increasing. The fundamental data obtained herein demonstrated that carbonate, phosphate and macromolecular organic matter significantly influenced the Tl(I) migration and could lead to the leaking or bindings of Tl(I) at Tl-occurring sites.

Thallium(I) Oxidation by Permanganate and Chlorine: Kinetics and Manganese Dioxide Catalysis.

The oxidation of the toxic heavy metal thallium(I) (Tl(I)) is an efficient way to enhance Tl removal from water and wastewater. However, few studies have focused on the kinetics of Tl(I) oxidation in water, especially at environmentally relevant pH values. Therefore, the kinetics and mechanisms of Tl(I) oxidation by the common agents KMnO4 and HOCl under environmentally relevant pH condition were explored in the present study. The results indicated that the pH-dependent oxidation of Tl(I) by KMnO4 exhibited second-order kinetics under alkaline conditions (pH 8-10) with the main active species being TlOH, while the reaction could be characterized by autocatalysis at pH 4-6, and Mn(III) might also play an essential role in the MnO2 catalysis. Furthermore, a two-electron transfer mechanism under alkaline conditions was preliminarily proposed by using linear free energy relationships and X-ray photoelectron spectroscopy (XPS) analysis. Distinctively, the reaction rate of Tl(I) oxidation by HOCl decreased with increasing pH, and protonated chlorine might be the main active species. Moreover, the Tl(I)-HOCl reaction could be regarded as first order with respect to Tl(I), but the order with respect to HOCl was variable. Significant catalysis by MnO2 could also be observed in the oxidation of Tl(I) by HOCl, mainly due to the vacancies on MnO2 as active sites for sorbing Tl. This study elucidates the oxidation characteristics of thallium and establishes a theoretical foundation for the oxidation processes in thallium removal.

Synthesis, Self-Assembly, and Biomedical Applications of Antimicrobial Peptide-Polymer Conjugates.

Antimicrobial peptides (AMPs) have been attracting much attention due to their excellent antimicrobial efficiency and low rate in driving antimicrobial resistance (AMR), which has been increasing globally to alarming levels. Conjugation of AMPs into functional polymers not only preserves excellent antimicrobial activities but reduces the toxicity and offers more functionalities, which brings new insight toward developing multifunctional biomedical materials such as hydrogels, polymer vesicles, polymer micelles, and so forth. These nanomaterials have been exhibiting excellent antimicrobial activity against a broad spectrum of bacteria including multidrug-resistant (MDR) ones, high selectivity, and low cytotoxicity, suggesting promising potentials in wound dressing, implant coating, antibiofilm, tissue engineering, and so forth. This Perspective seeks to highlight the state-of-the-art strategy for the synthesis, self-assembly, and biomedical applications of AMP-polymer conjugates and explore the promising directions for future research ranging from synthetic strategies, multistage and stimuli-responsive antibacterial activities, antifungi applications, and potentials in elimination of inflammation during medical treatment. It also will provide perspectives on how to stem the remaining challenges and unresolved problems in combating bacteria, including MDR ones.

Hydrogel scaffolds for differentiation of adipose-derived stem cells.

Natural extracellular matrices (ECMs) have been widely used as a support for the adhesion, migration, differentiation, and proliferation of adipose-derived stem cells (ADSCs). However, poor mechanical behavior and unpredictable biodegradation properties of natural ECMs considerably limit their potential for bioapplications and raise the need for different, synthetic scaffolds. Hydrogels are regarded as the most promising alternative materials as a consequence of their excellent swelling properties and their resemblance to soft tissues. A variety of strategies have been applied to create synthetic biomimetic hydrogels, and their biophysical and biochemical properties have been modulated to be suitable for cell differentiation. In this review, we first give an overview of common methods for hydrogel preparation with a focus on those strategies that provide potential advantages for ADSC encapsulation, before summarizing the physical properties of hydrogel scaffolds that can act as biological cues. Finally, the challenges in the preparation and application of hydrogels with ADSCs are explored and the perspectives are proposed for the next generation of scaffolds.

Pinching spine: A potential treatment for depression.

OBJECTIVE: To investigate whether pinching spine (PS, i.e. , a traditional Chinese manipulative therapy) is beneficial to ameliorating the depressive state (including behavioral deficit, retardative weight gain and decreased sucrose consumption) in a rat model of depression induced by chronic unpredictable stress (CUS) and to explore the candidate mechanism of action. METHODS: PS was performed on rats' spine once daily for 1 week after exposure to CUS. The open-field test, body weight measuring, and sucrose intake test were applied on different dates: before stress (d0), at the end of stress (d21) and after PS treatment (d28), respectively. Then the rats' hippocampuses were performed genome-wide microarray analysis, and the expression levels of several genes were evaluated by real-time polymerase chain reaction (PCR). RESULTS: Exposure to CUS resulted in decreases of behavioral activity and sucrose consumption, which were reversed significantly after PS treatment. The expression of several genes relevant to energy metabolism, anti-oxidation, and olfactory receptor, etc., were down-regulated, while the expression of those relevant to hemostasis, immunity-inflammation, and restriction of activities and ingestion, etc., were up-regulated in hippocampuses of rats exposed to CUS. PS treatment significantly inverted these changes. Furthermore, increase or decrease in gene expression evaluated by realtime PCR was concordant with up-regulated or down-regulated expression evaluated by microarray analysis. CONCLUSION: PS showed a potential antidepressant-like effect, of which the action mechanism might be due to gene expression regulation in hippocampus.

[Effect of electro-acupuncture on clinical outcomes and ovarian hyperstimulation syndrome in in vitro fertilization and embryo transplantation].

OBJECTIVE: To observe the effect of electro-acupuncture (EA) on clinical outcomes and the occurrence of ovarian hyperstimulation syndrome (OHSS) in in vitro fertilization and embryo transplantation. METHODS: Totally 109 patients who routinely received in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) at Reproductive Center were assigned to the control group (56 cases) and the EA group (53 cases) according to even and odd-numbered date. Patients in the control group received controlled ovarian hyperstimulation (COH) referring to GnRH-a long protocol. On the basis of COH, those in the EA group received EA from the day of Gn injection to the day of embryo transfer. Estradiol (E2), vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), and angiotensin (AT) II were measured in all patients on the day of hCG injection, the day of ovum pick up (OPU), and the day of embryo transfer (ET), respectively. The oocyte retrieval rate, good quality embryo rate, clinical pregnancy rate, the abortion rate, and the occurrence of OHSS were compared between the two groups. RESULTS: Compared with the control group, serum E2 levels on the day of OPU and the day of ET were significantly lower in the EA group (P < 0.05). On the day of OPU levels of VEGF and IL-6 also significantly decreased (P < 0.05). Serum levels of VEGF and IL-6 reached the highest line on the day of hCG in the two groups, and then showed a decreasing trend. Compared with the control group at the same time point, serum levels of VEGF and IL-6 obviously decreased on on the day of OPU, hCG, and ET (P < 0.05). The occurrence of OHSS and the canceling rate of transplant cycle were significantly lower in the EA group than in the control group (P < 0.05). CONCLUSIONS: EA, as an adjunctive therapy, could reduce the occurrence of OHSS in IVF. Besides, it did not decrease good embryo rates and pregnancy rates in IVF-ET, which might be associated with lowering local vascular permeability of ovaries.

Daucosterol promotes the proliferation of neural stem cells.

Neural stem cells (NSCs) are self-regenerating cells, but their regenerative capacity is limited. The present study was conducted to investigate the effect of daucosterol (a sterolin) on the promotion of NSC proliferation and determine the corresponding molecular mechanism. Results of cell counting kit-8 (CCK-8) assay showed that daucosterol significantly increased the quantity of viable cells and the effectiveness of daucosterol was similar to that of basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF). Flow cytometry detection of CFSE-labeled (CFSE, carboxyfluorescein diacetate succinimidyl ester) NSCs showed that Div Index (or the average number of cell divisions) and % Divided (or the percentage of cells that divided at least once) of the cells were increased, indicating that daucosterol increased the percentage of NSCs re-entering the cell cycle. mRNA microarray analysis showed that 333 genes that are mostly involved in the mitotic cell cycle were up-regulated. By contrast, 627 genes that are mostly involved in differentiation were down-regulated. In particular, insulin-like growth factor I (IGF1) was considered as an important regulatory gene that functionally promoted NSC proliferation, and the increased expression of IGF1 protein was validated by ELISA. In addition, the phosphorylation of AKT was increased, indicating that the proliferation-enhancing activity of daucosterol may be involved in IGF1-AKT pathway. Our study provided information about daucosterol as an efficient and inexpensive growth factor alternative that could be used in clinical medicine and research applications.

Microarray Analysis of mRNA and MicroRNA Expression Profile Reveals the Role of ß -Sitosterol-D-glucoside in the Proliferation of Neural Stem Cell.

Neural stem cells (NSCs) are self-regenerating cells, but their regenerative capacity is limited. The present study was conducted to investigate the effect of ß -sitosterol-D-glucoside (BSSG) on the proliferation of hippocampal NSCs and to determine the corresponding molecular mechanism. Results of CCK-8 assay showed that BSSG significantly increased NSC proliferation and the effectiveness of BSSG was similar to that of basic fibroblast growth factor and epidermal growth factor. mRNA expression profiling showed that 960 genes were differentially expressed after NSCs were treated with BSSG. Among the 960 genes, IGF1 is considered as a key regulatory gene that functionally promotes NSC proliferation. MicroRNA (miRNA) expression profiling indicated that 30 and 84 miRNAs were upregulated and downregulated, respectively. miRNA-mRNA relevance analysis revealed that numerous mRNAs including IGF1 mRNA were negatively regulated by miRNAs with decreased expression, thereby increasing the corresponding mRNA expression. The increased expression of IGF1 protein was validated by ELISA. Picropodophyllin (PPP, an inhibitor of IGF-1R) inhibition test confirmed that the proliferation-enhancing effect depended on IGF1. This study provided information about BSSG as an efficient and inexpensive growth factor alternative, of which the effect is closely involved in IGF1.