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1.
J Am Chem Soc ; 2024 Oct 04.
Article in English | MEDLINE | ID: mdl-39365080

ABSTRACT

The pursuit of precision in the engineering of metal nanoparticle assemblies has long fascinated scientists, but achieving atomic-level accuracy continues to pose a significant challenge. This research sheds light on the hierarchical assembly processes of two high-nuclearity Cu(I) nanoclusters (NCs). By employing a multiligand cooperative stabilization strategy, we have isolated a series of thiacalix[4]arene (TC4A)/alkynyl coprotected Cu(I) NCs (Cux, where x = 9, 13, 17, 22). These NCs are intricately coassembled from the fundamental building units of {Cu4(TC4A)} and alkynyl-stabilized Cu5L6 in various ratios. By capturing active anion templates such as O2-, Cl-, or C22- that are generated in situ, we have further explored the secondary structural self-assembly of these clusters. Cu13 serves as a secondary assembly module for constructing Cu38 and Cu43, which exhibit the highest nuclearity reported to date among Cu(I) NCs encased in macrocyclic ligands. Notably, Cu38 demonstrates an impressive Faradaic efficiency of 62.01% for hydrocarbons at -1.57 V vs RHE during CO2 electroreduction, with 34.03% for C2H4 and 27.98% for CH4. This performance establishes it as an exceptionally rare, large, atomically precise metal NC (nuclearity >30) capable of catalyzing the formation of highly electro-reduced hydrocarbon products. Our research has introduced a new approach for constructing high-nuclearity Cu(I) NCs through a hierarchical assembly method and investigating their potential in the electrocatalytic transformation of CO2 into hydrocarbons.

2.
Immunopharmacol Immunotoxicol ; 46(5): 703-714, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39134472

ABSTRACT

BACKGROUND: Gremlin1 is a multifunctional protein whose expression is demonstrated to be involved in a series of physiology and pathological processes. The association between Gremlin1 and apcial periodontitis (AP) has been established. M1-polarized macrophages are crucial immune cells that exacerbate the progression of apical periodontal inflammatory response, but the function of Gremlin1 during macrophages activation in periapical lesions is still unclear. This study attempts to explore the regulatory effects of Gremlin1 on macrophage polarization on apical periodontitis microenviroment. METHODS: Clinical specimens were used to determine the expression of Gremlin1 in periapical tissues by immunohistochemical (IHC) staining. Then, the disease models of periapical inflammation in rats were established, and adenovirus- associated virus (AAVs) was used to blockade Gremlin1 expression. Lentivirus carrying sh-Gremlin1 particles were used to transfect THP-1 induced M1-subtype macrophages. To assess the expression of associated molecules, Western blot, immunofluorescence staining were performed. RESULTS: Gremlin1 was significantly up-regulated in the periapical tissues of subjects with AP as identified by IHC staining, and positively correlated with levels of M1 macrophage-associated genes. Rats AP model with inhibition of Gremlin1 in periapical lesions exhibited limited infiltration of macrophages and decreased expression of M1 macrophage-related genes in periapical lesions. Furthermore, Gremlin1 blockade substantially decreased the Notch1/Hes1 signaling pathway activation level. The in vitro experiments confirmed the above results. CONCLUSION: Taken together, current study illustrated that the Gremlin1 suppression in periapical lesions inhibited M1 macrophage polarization through Notch1/Hes1 axis. Moreover, Gremlin1 may act as a potential candidate in the treatment of AP.


Subject(s)
Intercellular Signaling Peptides and Proteins , Macrophages , Periapical Periodontitis , Receptor, Notch1 , Signal Transduction , Transcription Factor HES-1 , Animals , Periapical Periodontitis/pathology , Periapical Periodontitis/metabolism , Periapical Periodontitis/immunology , Receptor, Notch1/metabolism , Humans , Macrophages/metabolism , Macrophages/immunology , Rats , Intercellular Signaling Peptides and Proteins/genetics , Intercellular Signaling Peptides and Proteins/metabolism , Male , Transcription Factor HES-1/metabolism , Transcription Factor HES-1/genetics , Female , Rats, Sprague-Dawley , THP-1 Cells , Macrophage Activation/drug effects , Disease Models, Animal
3.
Chem Sci ; 15(20): 7643-7650, 2024 May 22.
Article in English | MEDLINE | ID: mdl-38784741

ABSTRACT

Attaining meticulous dominion over the binding milieu of catalytic metal sites remains an indispensable pursuit to tailor product selectivity and elevate catalytic activity. By harnessing the distinctive attributes of a Zr4+-anchored thiacalix[4]arene (TC4A) metalloligand, we have pioneered a methodology for incorporating catalytic Ag1+ sites, resulting in the first Zr-Ag bimetallic cluster, Zr2Ag7, which unveils a dualistic configuration embodying twin {ZrAg3(TC4A)2} substructures linked by an {AgSal} moiety. This cluster unveils a trinity of discrete Ag sites: a pair ensconced within {ZrAg3(TC4A)2} subunits and one located between two units. Expanding the purview, we have also crafted ZrAg3 and Zr2Ag2 clusters, meticulously mimicking the two Ag site environment inherent in the {ZrAg3(TC4A)2} monomer. The distinct structural profiles of Zr2Ag7, ZrAg3, and Zr2Ag provide an exquisite foundation for a precise comparative appraisal of catalytic prowess across three Ag sites intrinsic to Zr2Ag7. Remarkably, Zr2Ag7 eclipses its counterparts in the electroreduction of CO2, culminating in a CO faradaic efficiency (FECO) of 90.23% at -0.9 V. This achievement markedly surpasses the performance metrics of ZrAg3 (FECO: 55.45% at -1.0 V) and Zr2Ag2 (FECO: 13.09% at -1.0 V). Utilizing in situ ATR-FTIR, we can observe reaction intermediates on the Ag sites. To unveil underlying mechanisms, we employ density functional theory (DFT) calculations to determine changes in free energy accompanying each elementary step throughout the conversion of CO2 to CO. Our findings reveal the exceptional proficiency of the bridged-Ag site that interconnects paired {ZrAg3(TC4A)2} units, skillfully stabilizing *COOH intermediates, surpassing the stabilization efficacy of the other Ag sites located elsewhere. The invaluable insights gleaned from this pioneering endeavor lay a novel course for the design of exceptionally efficient catalysts tailored for CO2 reduction reactions, emphatically underscoring novel vistas this research unshrouds.

4.
Zhongguo Zhong Yao Za Zhi ; 49(10): 2754-2765, 2024 May.
Article in Chinese | MEDLINE | ID: mdl-38812176

ABSTRACT

This study deciphered the ameliorating effect and molecular mechanism of the total glucosides of White Paeony Capsules(TGP) in the treatment of mice model with acute lung injury(ALI) via NOD-like receptor thermal protein domain associated protein 3(NLRP3) signaling pathway of the inflammasome. The study established an inflammasome activation model of primed bone marrow-derived macrophages(BMDMs), and its molecular mechanism was investigated by Western blot(WB), immunofluorescence staining, enzyme-linked immunosorbent assay(ELISA), and flow cytometry. C57BL/6J mice were randomly divided into a blank control group, a TGP group, a model group(LPS group), LPS+low-and high-dose TGP groups, LPS+MCC950 group, and LPS+MCC950+TGP group, with eight mice per group. The ALI model was induced in mice. Finally, bronchoalveolar lavage fluid(BALF) and lung tissue were collected. Lung index and lung weight wet-to-dry ratio were determined for each group of mice. The pathological changes in lung tissue were observed through hematoxylin-eosin(HE) staining. The number of neutrophils in the BALF of each group was detected using flow cytometry. The levels of interleukin(IL)-1ß, IL-6, and tumor necrosis factor(TNF)-α in the BALF were determined by ELISA. The expressions of IL-1ß, IL-18, IL-6, and TNF-α in the lung tissue were determined by real-time quantitative PCR(RT-qPCR). This study demonstrated that TGP dramatically blocked the activation of the NLRP3 inflammasome by inhibiting the production of upstream mitochondrial reactive oxygen species(mtROS) and the subsequent oligomerization of apoptosis-associated specks(ASC). Additionally, in the ALI mice model, compared with the blank control group, the model group showed alveolar structure rupture, thic-kening of alveolar septa, and dramatically increased lung index, lung weight wet-to-dry ratio in lung tissue, neutrophil count, and inflammatory factor levels. Compared with the model group, the pathological morphology of lung tissue was significantly ameliorated in the TGP and MCC950 groups, and the lung index and lung weight wet-to-dry ratio were significantly reduced. Neutrophil counts were reduced, and levels of inflammatory factors were significantly downregulated. Notably, compared with the MCC950 group, there was no significant difference in effect in the MCC950+TGP group. Collectively, the study reveals that TGP may ameliorate ALI in mice by inhibiting the activation of NLRP3 inflammasome, providing a safe and effective drug candidate for the prevention or treatment of ALI/ARDS.


Subject(s)
Acute Lung Injury , Drugs, Chinese Herbal , Glucosides , Inflammasomes , Mice, Inbred C57BL , NLR Family, Pyrin Domain-Containing 3 Protein , Paeonia , Animals , Acute Lung Injury/drug therapy , Acute Lung Injury/metabolism , Acute Lung Injury/immunology , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/genetics , Glucosides/pharmacology , Glucosides/chemistry , Mice , Inflammasomes/metabolism , Inflammasomes/drug effects , Male , Paeonia/chemistry , Drugs, Chinese Herbal/administration & dosage , Drugs, Chinese Herbal/pharmacology , Drugs, Chinese Herbal/chemistry , Capsules , Lung/drug effects , Lung/immunology , Lung/metabolism , Humans , Interleukin-1beta/genetics , Interleukin-1beta/immunology , Interleukin-1beta/metabolism
5.
Inorg Chem ; 63(15): 6767-6775, 2024 Apr 15.
Article in English | MEDLINE | ID: mdl-38569160

ABSTRACT

Electrolytic hydrogen production via water splitting holds significant promise for the future of the energy revolution. The design of efficient and abundant catalysts, coupled with a comprehensive understanding of the hydrogen evolution reaction (HER) mechanism, is of paramount importance. In this study, we propose a strategy to craft an atomically precise cluster catalyst with superior HER performance by cocoupling a Mo2O4 structural unit and a Cu(I) alkynyl cluster into a structured framework. The resulting bimetallic cluster, Mo2Cu17, encapsulates a distinctive structure [Mo2O4Cu17(TC4A)4(PhC≡C)6], comprising a binuclear Mo2O4 subunit and a {Cu17(TC4A)2(PhC≡C)6} cluster, both shielded by thiacalix[4]arene (TC4A) and phenylacetylene (PhC≡CH). Expanding our exploration, we synthesized two homoleptic CuI alkynyl clusters coprotected by the TC4A and PhC≡C- ligands: Cu13 and Cu22. Remarkably, Mo2Cu17 demonstrates superior HER efficiency compared to its counterparts, achieving a current density of 10 mA cm-2 in alkaline solution with an overpotential as low as 120 mV, significantly outperforming Cu13 (178 mV) and Cu22 (214 mV) nanoclusters. DFT calculations illuminate the catalytic mechanism and indicate that the intrinsically higher activity of Mo2Cu17 may be attributed to the synergistic Mo2O4-Cu(I) coupling.

6.
Parasite ; 31: 19, 2024.
Article in English | MEDLINE | ID: mdl-38530212

ABSTRACT

Trichomonads are protozoan symbionts with the capacity to infect vertebrates including humans and non-human primates (NHPs), sometimes with pathogenic effects. However, their diversity and prevalence in NHPs in China are poorly understood. A total of 533 fecal samples were collected from captive NHPs in Yunnan Province, China, of which 461 samples from Macaca fascicularis and 72 from Macaca mulatta. Trichomonadidae species were identified using PCR amplification of the ITS-1/5.8S/ITS-2 sequences. The overall prevalence of trichomonads in NHPs was determined to be 11.4% (61/533), with gender, diarrhea, and region identified as potential risk factors for the infections. Sequence alignment and phylogenetic analysis identified three species of trichomonads, i.e., Trichomitopsis minor (n = 45), Pentatrichomonas hominis (n = 11), and Tetratrichomonas sp. (n = 5). To the best of our knowledge, this is the first study to report Trichomitopsis minor infection in NHPs in China. Of note, Pentatrichomonas hominis is generally recognized as a parasitic organism affecting humans. Collectively, our results suggest that NHPs are potential sources of zoonotic trichomonad infections, highlighting the importance of surveillance and control measures to protect human and animal populations.


Title: Prévalence des Trichomonadidae intestinaux chez les primates non humains captifs en Chine. Abstract: Les Trichomonadidae sont des symbiotes protozoaires capables d'infecter les vertébrés, notamment les humains et les primates non humains (PNH), parfois avec des effets pathogènes. Cependant, leur diversité et leur prévalence chez les PNH en Chine sont mal comprises. Au total, 533 échantillons fécaux ont été collectés sur des PNH captifs dans la province du Yunnan, en Chine, dont 461 échantillons de Macaca fascicularis et 72 de Macaca mulatta. Les espèces de Trichomonadidae ont été identifiées par amplification PCR des séquences ITS-1/5.8S/ITS-2. La prévalence globale des Trichomonadidae dans les PNH a été déterminée à 11,4 % (61 / 533) et le sexe, la diarrhée et la région ont été identifiés comme facteurs de risque potentiels d'infection. L'alignement des séquences et l'analyse phylogénétique ont identifié trois espèces de Trichomonadidae, à savoir Trichomitopsis minor (n = 45), Pentatrichomonas hominis (n = 11) et Tetratrichomonas sp. (n = 5). À notre connaissance, il s'agit de la première étude à signaler une infection par Trichomitopsis minor chez les PNH en Chine. Il convient de noter que Pentatrichomonas hominis est généralement reconnu comme un organisme parasitaire affectant les humains. Collectivement, nos résultats suggèrent que les PNH sont des sources potentielles d'infections zoonotiques à Trichomonadidae, soulignant l'importance des mesures de surveillance et de contrôle pour protéger les populations humaines et animales.


Subject(s)
Primates , Trichomonas , Animals , China/epidemiology , Phylogeny , Prevalence , Intestines , Zoonoses/epidemiology
7.
Cell ; 187(5): 1127-1144.e21, 2024 Feb 29.
Article in English | MEDLINE | ID: mdl-38428393

ABSTRACT

Chloroplasts are green plastids in the cytoplasm of eukaryotic algae and plants responsible for photosynthesis. The plastid-encoded RNA polymerase (PEP) plays an essential role during chloroplast biogenesis from proplastids and functions as the predominant RNA polymerase in mature chloroplasts. The PEP-centered transcription apparatus comprises a bacterial-origin PEP core and more than a dozen eukaryotic-origin PEP-associated proteins (PAPs) encoded in the nucleus. Here, we determined the cryo-EM structures of Nicotiana tabacum (tobacco) PEP-PAP apoenzyme and PEP-PAP transcription elongation complexes at near-atomic resolutions. Our data show the PEP core adopts a typical fold as bacterial RNAP. Fifteen PAPs bind at the periphery of the PEP core, facilitate assembling the PEP-PAP supercomplex, protect the complex from oxidation damage, and likely couple gene transcription with RNA processing. Our results report the high-resolution architecture of the chloroplast transcription apparatus and provide the structural basis for the mechanistic and functional study of transcription regulation in chloroplasts.


Subject(s)
DNA-Directed RNA Polymerases , Plastids , Chloroplasts/metabolism , Cryoelectron Microscopy , DNA-Directed RNA Polymerases/genetics , Nicotiana/genetics , Photosynthesis , Plastids/enzymology
8.
Front Microbiol ; 15: 1287641, 2024.
Article in English | MEDLINE | ID: mdl-38328417

ABSTRACT

Through whole-genome re-sequencing of 18 Hymenopellis radicata germplasm resources collected from diverse regions in China, we identified significant variations in the form of Single Nucleotide Polymorphisms (SNPs) and Insertions and Deletions (InDels). These variations were comprehensively annotated, shedding light on the mutation types present in the entire genome of the H. radicata germplasm. This analysis revealed the number and position information of each mutation and provided insights into the overall genomic landscape of H. radicata germplasm. Utilizing SNP data, we delved into the population structure of the 18 H. radicata germplasm resources. The results indicated the presence of 2,335,179 Indel sites and 12,050,448 SNP sites. The population structure analysis unveiled two distinct subgroups among the H. radicata germplasm resources. Phenotypic statistics, principal component analysis, and phylogenetic tree results echoed the findings of the population structure analysis. Different strains of H. radicata from various regions in China exhibited notable differences in genetic diversity, mycelial growth rate, yield, and fruiting body characteristics. Significant disparities were observed between the two subgroups, while strains within each subgroup shared common characteristics. This research establishes a solid foundation for integrating H. radicata into diverse breeding programs. The data underscore the potential of H. radicata for genetic improvement and exploitation in breeding initiatives, paving the way for future advancements in this field.

9.
Chem Sci ; 14(48): 14280-14289, 2023 Dec 13.
Article in English | MEDLINE | ID: mdl-38098712

ABSTRACT

Skillfully engineering surface ligands at specific sites within robust clusters presents both a formidable challenge and a captivating opportunity. Herein we unveil an unprecedented titanium-oxo cluster: a calix[8]arene-stabilized metallamacrocycle (Ti16L4), uniquely crafted through the fusion of four "core-shell" {Ti4@(TBC[8])(L)} subunits with four oxalate moieties. Notably, this cluster showcases an exceptional level of chemical stability, retaining its crystalline integrity even when immersed in highly concentrated acid (1 M HNO3) and alkali (20 M NaOH). The macrocycle's surface unveils four specific, customizable µ2-bridging sites, primed to accommodate diverse carboxylate ligands. This adaptability is highlighted through deliberate modifications achieved by alternating crystal soaking in alkali and carboxylic acid solutions. Furthermore, Ti16L4 macrocycles autonomously self-assemble into one-dimensional nanotubes, which subsequently organize into three distinct solid phases, contingent upon the specific nature of the four µ2-bridging ligands. Notably, the Ti16L4 exhibit a remarkable capacity for photocatalytic activity in selectively reducing CO2 to CO. Exploiting the macrocycle's modifiable shell yields a significant boost in performance, achieving an exceptional maximum CO release rate of 4.047 ± 0.243 mmol g-1 h-1. This study serves as a striking testament to the latent potential of precision-guided surface ligand manipulation within robust clusters, while also underpinning a platform for producing microporous materials endowed with a myriad of surface functionalities.

10.
Dalton Trans ; 52(44): 16303-16314, 2023 Nov 14.
Article in English | MEDLINE | ID: mdl-37855372

ABSTRACT

In the reaction of oxidizing 5-hydroxymethylfurfural (HMF), attaining high efficiency and selectivity in the conversion of HMF into DFF presents a challenge due to the possibility of forming multiple products. Polyoxometalates are considered highly active catalysts for HMF oxidation. However, the over-oxidation of products poses a challenge, leading to decreased purity and yield. In this work, metal-organic framework-derived Fe3O4/C and Co3O4/C were designed as carriers for the vanadium-substituted Keggin-type polyoxomolybdate H5PMo10V2O40·35H2O (PMo10V2). In this complex system, spinel oxides can effectively adsorb HMF molecules and cooperate with PMo10V2 to catalyze the aerobic oxidation of HMF. As a result, the as-prepared PMo10V2@Fe3O4/C and PMo10V2@Co3O4/C catalysts can achieve efficient conversion of HMF into DFF with almost 100% selectivity. Among them, PMo10V2@Fe3O4/C exhibits a higher conversion rate (99.1%) under milder reaction conditions (oxygen pressure of 0.8 MPa). Both catalysts exhibited exceptional stability and retained their activity and selectivity even after undergoing multiple cycles. Studies on mechanisms by in situ diffuse reflectance infrared Fourier transform spectroscopy and X-ray photoelectron spectroscopy revealed that the V5+ and Mo6+ in PMo10V2, together with the metal ions in the spinel oxides, act as active centers for the catalytic conversion of HMF. Therefore, it is proposed that PMo10V2 and M3O4/C (M = Fe, Co) cooperatively catalyze the transformation of HMF into DFF via a proton-coupled electron transfer mechanism. This study offers an innovative approach for designing highly selective and recyclable biomass oxidation catalysts.

11.
Chem Sci ; 14(37): 10212-10218, 2023 Sep 27.
Article in English | MEDLINE | ID: mdl-37772117

ABSTRACT

The accurate identification of catalytic sites in heterogeneous catalysts poses a significant challenge due to the intricate nature of controlling interfacial chemistry at the molecular level. In this study, we introduce a novel strategy to address this issue by utilizing a thiacalix[4]arene (TC4A)-protected Ti-oxo core as a template for loading Ag1+ ions, leading to the successful synthesis of a unique Ag/Ti bimetallic nanocluster denoted as Ti8Ag8. This nanocluster exhibits multiple surface-exposed Ag sites and possesses a distinctive "core-shell" structure, consisting of a {Ti4@Ag8(TC4A)4} core housing a {Ti2O2@Ag4(TC4A)2} motif and two {Ti@Ag2(TC4A)} motifs. To enable a comprehensive analysis, we also prepared a Ti2Ag4 cluster with the same {Ti2O2@Ag4(TC4A)2} structure found within Ti8Ag8. The structural disparities between Ti8Ag8 and Ti2Ag4 provide an excellent platform for a comparison of catalytic activity at different Ag sites. Remarkably, Ti8Ag8 exhibits exceptional performance in the electroreduction of CO2 (eCO2RR), showcasing a CO faradaic efficiency (FECO) of 92.33% at -0.9 V vs. RHE, surpassing the FECO of Ti2Ag4 (69.87% at -0.9 V vs. RHE) by a significant margin. Through density functional theory (DFT) calculations, we unveil the catalytic mechanism and further discover that Ag active sites located at {Ti@Ag2(TC4A)} possess a higher εd value compared to those at {Ti2O2@Ag4(TC4A)2}, enhancing the stabilization of the *COOH intermediate during the eCO2RR. This study provides valuable insights into the accurate identification of catalytic sites in bimetallic nanoclusters and opens up promising avenues for efficient CO2 reduction catalyst design.

12.
Yi Chuan ; 45(5): 425-434, 2023 May 20.
Article in English | MEDLINE | ID: mdl-37194589

ABSTRACT

Hypothalamic median eminence (ME) is a potential niche for neurons and oligodendrocytes, and trophic factors may regulate hypothalamic function by inducing cellular changes in the ME region. To determine whether diet-induced plasticity exists in hypothalamic stem cells dormant under physiological conditions, we used a combination of a normal diet, a high-fat diet, and a ketogenic diet (a low-carb, high-fat diet) to compare the proliferation of tanycytes (TCs) and oligodendrocyte precursor cells (OPCs) in the ME area of mice under the different diets. The results showed that the ketogenic diet could induce and promote the proliferation of OPCs in the ME area, and blocking the fatty acid oxidation program could inhibit the proliferation of OPCs induced by a ketogenic diet. This study preliminarily revealed the diet-induced effect on OPCs in the ME region and provided enlightenment for further study on the function of OPCs in the ME region.


Subject(s)
Diet, Ketogenic , Oligodendrocyte Precursor Cells , Mice , Animals , Median Eminence , Cell Proliferation , Fatty Acids , Cell Differentiation
13.
Dalton Trans ; 52(17): 5438-5442, 2023 May 02.
Article in English | MEDLINE | ID: mdl-37083046

ABSTRACT

Accurate manipulation of ligands at specific sites in robust clusters is attractive but difficult, especially for those ligands that coordinate in intricate binding patterns. By linking the shuttlecock-like {Cu4(µ4-Cl)TC4A} motif and the phenylphosphate (PhPO32-) ligand, we elaborately design and synthesize two Cu(II)-thiacalix[4]arene metallamacrocycles (MMCs), namely Cu12L3 and Cu16L4, which have regular triangular and quadrilateral topologies, respectively. While keeping the core intact, the Cl- and PhPO32- in those two MMCs, which coordinated in a µ4-bridging fashion, can be accurately substituted with salicylate ligands. Theoretical calculations have been carried out to reveal the effect of ligand tailoring on the electronic structure of clusters. Structural regulation can affect the catalytic activity of these clusters, which has been verified by using the clusters as catalysts for selective sulfide oxidation.

15.
Chemosphere ; 327: 138477, 2023 Jun.
Article in English | MEDLINE | ID: mdl-36966928

ABSTRACT

The long-term effectiveness of heavy metal immobilization is always a concern. This study proposes a completely novel approach to enhance the stability of heavy metals by combined biochar and microbial induced carbonate precipitation (MICP) technology, to create a "surface barrier" of CaCO3 layer on biochar after lead (Pb2+) immobilization. Aqueous sorption studies and chemical and micro-structure tests were used to verify the feasibility. Rice straw biochar (RSB700) was produced at 700 °C, which shows high immobilization capacity of Pb2+ (maximum of 118 mg g-1). But the stable fraction only accounts for 4.8% of the total immobilized Pb2+ on biochar. After MICP treatment, the stable fraction of Pb2+ significantly increased to a maximum of 92.5%. Microstructural tests confirm the formation of CaCO3 layer on biochar. The CaCO3 species are predominantly calcite and vaterite. Higher Ca2+ and urea concentrations in cementation solution resulted in higher CaCO3 yield but lower Ca2+ utilization efficiency. The main mechanism of the "surface barrier" to enhance Pb2+ stability on biochar was likely the encapsulation effect: it physically blocked the contact between acids and Pb2+ on biochar, and chemically buffer the acidic attack from the environment. The performance of the "surface barrier" depends on both the yield of CaCO3 and their distribution uniformity on biochar's surface. This study shed lights on the potential application of the "surface barrier" strategy combining biochar and MICP technologies for enhanced heavy metal immobilization.


Subject(s)
Environmental Restoration and Remediation , Metals, Heavy , Soil Pollutants , Lead , Soil Pollutants/analysis , Charcoal/chemistry , Metals, Heavy/analysis , Calcium Carbonate , Soil/chemistry
16.
Int J Mol Sci ; 24(3)2023 Jan 24.
Article in English | MEDLINE | ID: mdl-36768624

ABSTRACT

Flame-retardant cycloaliphatic epoxy systems have long been studied; however, the research suffers from slow and unsatisfactory advances. In this work, we synthesized a kind of phosphorus-containing difunctional cycloaliphatic epoxide (called BCEP). Then, triglycidyl isocyanurate (TGIC) was mixed with BCEP to achieve epoxy systems that are rich in phosphorus and nitrogen elements, which were cured with 4-methylhexahydrobenzene anhydride (MeHHPA) to obtain a series of flame-retardant epoxy resins. Curing behaviors, flame retardancy, thermal behaviors, dielectric performance, and the chemical degradation behaviors of the cured epoxy system were investigated. BCEP-TGIC systems showed a high curing activity, and they can be efficiently cured, in which the incorporation of TGIC decreased the curing activity of the resin. As the ratio of BCEP and TGIC was 1:3, the cured resin (BCEP1-TGIC3) showed a relatively good flame retardancy with a limiting oxygen index value of 25.2%. In the cone calorimeter test, they presented a longer time to ignition and a lower heat release than the commercially available cycloaliphatic epoxy resins (ERL-4221). BCEP-TGIC systems presented good thermal stability, as the addition of TGIC delayed the thermal weight loss of the resin. BCEP1-TGIC3 had high dielectric performance and outperformed ERL-4221 over a frequency range of 1 HZ to 1 MHz. BCEP1-TGIC3 could achieve degradation under mild conditions in an alkali methanol/water solution. Benefiting from the advances, BCEP-TGIC systems have potential applications as electronic packaging materials in electrical and electronic fields.


Subject(s)
Epoxy Resins , Flame Retardants , Alkalies , Anhydrides , Electronics , Phosphorus , Resins, Plant
17.
Molecules ; 28(2)2023 Jan 05.
Article in English | MEDLINE | ID: mdl-36677592

ABSTRACT

Apigenin is a natural flavonoid with significant biological activity, but poor solubility in water and low bioavailability limits its use in the food and pharmaceutical industries. In this paper, apigenin-7-O-ß-(6″-O)-d-glucoside (AG) and apigenin-7-O-ß-(6″-O-succinyl)-d-glucoside (SAG), rare apigenin glycosyl and succinyl derivatives formed by the organic solvent-tolerant bacteria Bacillus licheniformis WNJ02 were used in a 10.0% DMSO (v/v) system. The water solubility of SAG was 174 times that of apigenin, which solved the application problem. In the biotransformation reaction, the conversion rate of apigenin (1.0 g/L) was 100% at 24 h, and the yield of SAG was 94.2%. Molecular docking showed that the hypoglycemic activity of apigenin, apigenin-7-glucosides (AG), and SAG was mediated by binding with amino acids of α-glucosidase. The molecular docking results were verified by an in vitro anti-α-glucosidase assay and glucose consumption assay of active compounds. SAG had significant anti-α-glucosidase activity, with an IC50 of 0.485 mM and enhanced glucose consumption in HepG2 cells, which make it an excellent α-glucosidase inhibitor.


Subject(s)
Apigenin , Hypoglycemic Agents , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/chemistry , Glycosylation , Apigenin/chemistry , Molecular Docking Simulation , alpha-Glucosidases/metabolism , Glucose , Glucosides/chemistry
18.
Transl Neurodegener ; 12(1): 1, 2023 01 09.
Article in English | MEDLINE | ID: mdl-36624510

ABSTRACT

BACKGROUND: Ribosomal protein S6 kinase 1 (S6K1) is a serine-threonine kinase that has two main isoforms: p70S6K (70-kDa isoform) and p85S6K (85-kDa isoform). p70S6K, with its upstream mammalian target of rapamycin (mTOR), has been shown to be involved in learning and memory and participate in the pathophysiology of Alzheimer's disease (AD). However, the function of p85S6K has long been neglected due to its high similarity to p70S6k. The role of p85S6K in learning and memory is still largely unknown. METHODS: We fractionated the postsynaptic densities to illustrate the differential distribution of p85S6K and p70S6K. Coimmunoprecipitation was performed to unveil interactions between p85S6K and the GluA1 subunit of AMPA receptor. The roles of p85S6K in synaptic targeting of GluA1 and learning and memory were evaluated by specific knockdown or overexpression of p85S6K followed by a broad range of methodologies including immunofluorescence, Western blot, in situ proximity ligation assay, morphological staining and behavioral examination. Further, the expression level of p85S6K was measured in brains from AD patients and AD model mice. RESULTS: p85S6K, but not p70S6K, was enriched in the postsynaptic densities. Moreover, knockdown of p85S6K resulted in defective spatial and recognition memory. In addition, p85S6K could interact with the GluA1 subunit of AMPA receptor through synapse-associated protein 97 and A-kinase anchoring protein 79/150. Mechanistic studies demonstrated that p85S6K could directly phosphorylate GluA1 at Ser845 and increase the amount of GluA1 in synapses, thus sustaining synaptic function and spine densities. Moreover, p85S6K was found to be specifically decreased in the synaptosomal compartment in the brains of AD patients and AD mice. Overexpression of p85S6K ameliorated the synaptic deficits and cognitive impairment in transgenic AD model mice. CONCLUSIONS: These results strongly imply a significant role for p85S6K in maintaining synaptic and cognitive function by interacting with GluA1. The findings provide an insight into the rational targeting of p85S6K as a therapeutic potential for AD.


Subject(s)
Alzheimer Disease , Cognitive Dysfunction , Animals , Mice , Alzheimer Disease/genetics , Receptors, AMPA , Cognitive Dysfunction/genetics , Cognition , Mice, Transgenic , Mammals
19.
Front Cardiovasc Med ; 9: 1038176, 2022.
Article in English | MEDLINE | ID: mdl-36457800

ABSTRACT

Background: Perivascular adipose tissue (PVAT), an active endocrine organ, exerts direct effect on vascular tone through paracrine. Activation of PVAT metabolism plays an inhibitory role in atherosclerosis via secreting relaxing factors. The present studies were designed to investigate the role of PVAT metabolism in regulation of hypertension. Materials and methods: Apolipoprotein E (ApoE) knockout mice with BMP4 knockout in adipose tissue or brown adipose tissue (aP2-DKO or UCP1-DKO, respectively) were used for exploring the role of impaired PVAT metabolism in hypertension. Vascular function was assessed using wire myography. The potential regulatory factor of vascular function was explored using qPCR and ELISA and further confirmed in perivascular fat cell line. Results: Knockout of BMP4 either in adipose tissue or specifically in BAT aggravates high-fat diet (HFD, 40% fat)-induced hypertension and endothelial dysfunction in ApoE-/- mice. In the meanwhile, deficiency of BMP4 also aggravates Ang II (angiotensin II) -induced hypertension and vascular remodeling in ApoE-/- mice. Moreover, deficiency of BMP4 inhibits NO release and induces ROS production. In vitro system, aortic rings pretreated with PVAT extracts from BMP4-DKO mice showed increased vasoconstriction and reduced endothelial-dependent relaxation compared with the controls. We further demonstrated that PVAT of BMP4-DKO mice expressed higher level of angiotensinogen (AGT) and Ang II compared with the controls. Conclusion: Impaired PVAT metabolism aggravates hypertension, and this effect is dependent on the activation of local renin-angiotensin-aldosterone system (RAAS). The results of this study first demonstrate the regulatory role of PVAT metabolism in hypertension.

20.
Zhongguo Zhong Yao Za Zhi ; 47(22): 6146-6154, 2022 Nov.
Article in Chinese | MEDLINE | ID: mdl-36471939

ABSTRACT

Since exploding rates of modern mental diseases, application of antidepressants has increased. Worryingly, the antidepressant-induced liver injury has gradually become a serious health burden. Furthermore, since most of the knowledge about antidepressant hepatotoxicity are from pharmacovigilance and clinical case reports and lack of observational studies, the underlying mechanisms are poorly understood and there is a lack of efficient treatment strategies. In this study, antidepressant paroxetine directly triggered inflammasome activation evidenced by caspase-1 activation and downstream effector cytokines interleukin(IL)-1ß secretion. The pretreatment of echinatin, a bioactive component of licorice, completely blocked the activation. This study also found that echinatin effectively inhibited the production of inflammasome-independent tumor necrosis factor α(TNF)-α induced by paroxetine. Mechanistically, the accumulation of mitochondrial reactive oxygen species(mtROS) was a key upstream event of paroxetine-induced inflammasome activation, which was dramatically inhibited by echinatin. In the lipopolysaccharide(LPS)-mediated idiosyncratic drug-induced liver injury(IDILI) model, the combination of LPS and paroxetine triggered aberrant activation of the inflammasome to induce idiosyncratic hepatotoxicity, which was reversed by echinatin pretreatment. Notably, this study also found that various bioactive components of licorice had an inhibitory effect on paroxetine-triggered inflammasome activation. Meanwhile, multiple antidepressant-induced aberrant activation of the inflammasome could be completely blocked by echinatin pretreatment. In conclusion, this study provides a novel insight for mechanism of antidepressant-induced liver injury and a new strategy for the treatment of antidepressant-induced hepatotoxicity.


Subject(s)
Antidepressive Agents , Chalcones , Chemical and Drug Induced Liver Injury, Chronic , Glycyrrhiza , Paroxetine , Animals , Humans , Mice , Antidepressive Agents/adverse effects , Chemical and Drug Induced Liver Injury, Chronic/prevention & control , Glycyrrhiza/chemistry , Inflammasomes/drug effects , Interleukin-1beta/metabolism , Lipopolysaccharides/toxicity , Mice, Inbred C57BL , NLR Family, Pyrin Domain-Containing 3 Protein , Paroxetine/adverse effects , Tumor Necrosis Factor-alpha , Chalcones/pharmacology , Chalcones/therapeutic use
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