N-Coordinated Cu-Ni Dual-Single-Atom Catalyst for Highly Selective Electrocatalytic Reduction of Nitrate to Ammonia.

As a traditional method of ammonia (NH3 ) synthesis, Haber-Bosch method expends a vast amount of energy. An alternative route for NH3 synthesis is proposed from nitrate (NO3 - ) via electrocatalysis. However, the structure-activity relationship remains challenging and requires in-depth research both experimentally and theoretically. Here an N-coordinated Cu-Ni dual-single-atom catalyst anchored in N-doped carbon (Cu/Ni-NC) is reported, which has competitive activity with a maximal NH3 Faradaic efficiency of 97.28%. Detailed characterizations demonstrate that the high activity of Cu/Ni-NC mainly comes from the contribution of Cu-Ni dual active sites. That is, (1) the electron transfer (Ni â†’ Cu) reveals the strong electron interaction of Cu-Ni dual-single-atom; (2) the strong hybridizations of Cu 3d-and Ni 3d-O 2p orbitals of NO3 - can accelerate electron transfer from Cu-Ni dual-site to NO3 - ; (3) Cu/Ni-NC can effectively decrease the rate-limiting step barriers, suppress N-N coupling for N2 O and N2 formation and hydrogen production.

Boosting CO Catalytic Oxidation Performance via Highly Dispersed Copper Atomic Clusters: Regulated Electron Interaction and Reaction Pathways.

Copper-loaded ceria (Cu/CeO2) catalysts have become promising for the catalytic oxidation of industrial CO emissions. Since their superior redox property mainly arises from the synergistic effect between Cu and the CeO2 support, the dispersion state of Cu species may dominate the catalytic performance of Cu/CeO2 catalysts: the extremely high or low dispersity is disadvantageous for the catalytic performance. The nanoparticle catalysts usually present few contact sites, while the single-atom catalysts tend to be passivated due to their relatively single valence state. To achieve a suitable dispersion state, we synthesized a superior Cu/CeO2 catalyst with Cu atomic clusters, realizing high atomic exposure and unit atomic activity simultaneously via favorable electron interaction and an anchoring effect. The catalyst reaches a 90% CO conversion at 130 °C, comparable to noble-metal catalysts. According to combined in situ spectroscopy and density functional theory calculations, the superior CO oxidation performance of the Cu atomic cluster catalyst results from the joint efforts of effective adsorption of CO at the electrophilic sites, the CO spillover phenomenon, and the efficient bicarbonate pathway triggered by hydroxyl. By providing a superior atomic cluster catalyst and uncovering the catalytic oxidation mechanism of Cu-Ce dual-active sites, our work may enlighten future research on industrial gaseous pollutant removal.

Incompatibility Mechanism Between Radix Paeoniae Alba and Veratrum nigrum Focusing on Estrogen-Estrogen Receptor Pathway in Immature/Ovariectomized Mice.

Radix paeoniae alba (RPA) and Veratrum nigrum (VN) L. belong to the 18 incompatible medicaments and have been prohibited for thousands of years in China. Previous studies focused on the chemical constituents that induced the toxicological response of the two agents, but this study offers preliminary insight into the pharmacodynamics and mechanism on estrogenic activity, which is responsible for their incompatibility. We undertook a characterization of the interaction on estrogenic activity of RPA and VN using in vivo models of immature and ovariectomized (OVX) mice and in vitro studies focused on estrogen receptor (ER) pathway for further mechanism. VN disturbed the estrogenic efficacy of RPA in promoting development of uterus and vagina in immature mice, and reversing the atrophy of reproductive tissues in OVX mice by decreasing the increase of serum estrogen level and upregulation of ER expression in reproductive tissues by treatment with RPA. Besides, VN antagonized the estrogenic efficacy of RPA in stimulating the binding with ERα and ERß, increasing ERα/ß-estrogen response element (ERE) luciferase reporter gene expression and promoting MCF-7 cell viability. This study provided evidence that VN antagonized the estrogenic efficacy of RPA by decreasing the up-regulations of estrogen biosynthesis in circulation and ERs in target tissues caused by RPA, and through ER-ERE-dependent pathway.

Radix Paeoniae Alba increases serum estrogen level and up-regulates estrogen receptor expression in uterus and vagina of immature/ovariectomized mice.

Radix Paeoniae Alba (RPA) is widely used in clinical treatment for gynecological diseases, particularly abnormal menstruation, menstrual pain, and breast tenderness; however, no scientific evidence base links RPA to estrogen replacement therapy. In this study, we characterize estrogenic activity of RPA using immature and ovariectomized (OVX) mice together with in vitro studies focus on estrogen receptor (ER) pathway for molecular mechanism. RPA treatments demonstrated significant estrogenic activity, as indicated by promoting the development of uterus and vagina in immature mice, reversing the atrophy of uterus and vagina in OVX mice, up-regulating the expressions of ERα and ERß at protein and mRNA level in reproductive tissues. Meanwhile, RPA significantly increased serum estradiol and clearly decreased serum luteinizing hormone and follicle-stimulating hormone of immature/OVX mice. Moreover, RPA could induce ER positive MCF-7 cell from S-phase to G2 stage and induce proliferation and no influence on ER negative MDA-MB-231 cell. RPA could bind with ERα and ERß and significantly stimulate ERα/ß-estrogen response element (ERE) luciferase reporter gene expression. All activities were inhibited by the ER antagonist ICI 182,780. This study illustrates RPA exerts estrogenic effects by stimulating biosynthesis of estrogen in circulation, up-regulating ERs in target tissues, and mimicking the estrogen through ER-ERE-dependent pathway.

Salvia miltiorrhiza bunge increases estrogen level without side effects on reproductive tissues in immature/ovariectomized mice.

Salvia miltiorrhiza bunge(SM) is a popular herb for alleviating menopausal symptoms, although the scientific evidence of applying SM to estrogen replacement therapy is limited. In this study, we characterized the estrogenic activity of SM using in vivo models of immature and ovariectomized (OVX) mice and performed in vitro studies focusing on the estrogen receptor (ER) pathway for further molecular characterizations. SM treatments demonstrated significant estrogenic activity by promoting the development of uterus and vagina in immature mice, restoring the estrus cycle and reversing the atrophy of reproductive tissues in OVX mice, as well as increasing the expressions of ERα and ERß at protein and mRNA level in the reproductive tissues. Meanwhile, SM significantly increased estradiol in serum, and decreased follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in the circulation of immature and OVX mice. SM could stimulate the binding effect of ERα and ERß, and significantly induce ERα/ß-estrogen response element (ERE) luciferase reporter gene expression. All these activities were inhibited by the ER antagonist ICI182, 780. This study demonstrates SM exerts estrogenic effects by stimulating biosynthesis of estrogen and increasing ERs in target tissues without side effects on reproductive tissues and through ER-ERE-dependent pathway.

Effect of the Interaction of Veratrum Nigrum with Panax Ginseng on Estrogenic Activity In Vivo and In Vitro.

Panax ginseng (GS) and Veratrum nigrum (VN) are representative of incompatible pairs in "eighteen antagonistic medicaments" that have been recorded in the Chinese medicinal literature for over 2,000 years. However, evidence linking interference effects with combination use is scare. Based on the estrogen-like effect of GS described in our previous studies, we undertake a characterization of the interaction on estrogenic activity of GS and VN using in vivo models of immature and ovariectomized (OVX) mice and in vitro studies with MCF-7 cells for further mechanism. VN decreased the estrogenic efficacy of GS on promoting the development of the uterus and vagina in immature mice, and reversing the atrophy of reproductive tissues in OVX mice. VN interfered with the estrogenic efficacy of GS by decreasing the increase of the serum estradiol and the up-regulation of ERα and ERß expressions by treatment with GS. And VN antagonized the estrogenic efficacy of GS on promoting the viability of MCF-7 cells and up-regulation of protein and gene expressions of ERs. In conclusion, this study provided evidence that GS and VN decreased effects on estrogenic activity, which might be related to regulation of estrogen secretion and ERs.

Short-time QiBaoMeiRan Formula Treatment Exerts Estrogenic Activities without Side Effects on Reproductive Tissues in Immature Mice.

The Chinese herbal preparation QiBaoMeiRan formula (QBMR) displayed estrogenic effects in ovariectomized rats after long-term administration in a previous study. The uterus and vagina are negatively influenced by estrogens in hormone therapy. While QBMR is known to be a phytoestrogen, its estrogenic effects and safety on reproductive tissues after short-term administration and its mechanism via estrogen receptor (ER) pathway haven't been studied. Here, we characterized its estrogenic effects using immature mice together with in vitro studies for further molecular characterization. Immature mice were treated with QBMR at doses of 1.125, 2.25, and 4.5 g/kg for 7 days. 1.125 and 2.25 g/kg QBMR promoted the growth and development of uterus and vagina, and upregulated ERα and ERß expression in reproductive tissues. QBMR had a stimulatory effect on proliferating cell nuclear antigen in vagina but not in uterus, and was without any influence on ki-67 antigen in uterus and vagina. QBMR significantly induced luciferase expression from the ERα/ß-estrogen response element (ERE) luciferase reporter and upregulated ERα and ERß expressions in MCF-7 cells, which were significantly inhibited by estrogen antagonist ICI182,780. This study demonstrated QBMR exerts estrogenic effects on reproductive tissues without side effects and through ER-ERE-dependent pathway.

Wu-tou decoction inhibits chronic inflammatory pain in mice: participation of TRPV1 and TRPA1 ion channels.

Wu-tou decoction (WTD) is a classic traditional Chinese medicine formula and has been used effectively to treat joint diseases clinically. Previous reports indicated that WTD possesses anti-inflammatory activity; however, its actions on pain have not been clarified. Here, we investigated the antinociceptive activity of WTD in CFA-induced mice, and its possible mechanism of the action associated with transient receptor potential (TRP) ion channels was also explored. Our results showed that 1.58, 3.15, and 6.30 g/kg WTD significantly attenuated mechanical, cold, and heat hypersensitivities. Moreover, WTD effectively inhibited spontaneous nociceptive responses to intraplantar injections of capsaicin and cinnamaldehyde, respectively. WTD also effectively suppressed jumping and wet-dog-shake behaviors to intraperitoneal injection of icilin. Additionally, WTD significantly reduced protein expression of TRPV1 and TRPA1 in dorsal root ganglia and skins of injured paw. Collectively, our data demonstrate firstly that WTD exerts antinociceptive activity in inflammatory conditions by attenuating mechanical, cold, and heat hypersensitivities. This antinociceptive effect may result in part from inhibiting the activities of TRPV1, TRPA1, and TRPM8, and the suppression of TRPV1 and TRPA1 protein by WTD was also highly effective. These findings suggest that WTD might be an attractive and suitable therapeutic agent for the management of chronic inflammatory pain.