Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 157
Filtrar
1.
J Environ Manage ; 365: 121563, 2024 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-38909575

RESUMO

Steel slag (SS) is a byproduct that comes from the production of crude steel in alkaline oxidation furnaces. Resource utilization of steel slag, a calcium-silicon solid waste, is an urgent problem. This paper investigates a solid waste disposal method that applies different steel slag contents to modify dispersive soil. The engineering properties and modification mechanisms of dispersive soil specimens are studied and revealed by performing microstructure, mineral evolution, unconfined compressive strength (UCS), and tensile strength analysis. The pinhole test, mud ball crumb test (BCT), and mud cube crumb test (CCT) were carried out to determine the dispersivity of the soil specimens. Results show that when the steel slag content increases from 1% to 10%, the unconfined compressive strength and tensile strength increase by 176.05% and 75.40%, respectively. For soil specimens without curing time under 50 mm water head, the weight loss of the specimen with 10% steel slag content decreases by 72.03% compared to specimens with 1% steel slag content. Microstructural and mineralogical analyses indicate that the hydration reaction of steel slag changes the ionic composition of the soil and generates reaction products with effects such as filling and connection. To sum up, steel slag effectively improves water stability and mechanical properties of dispersive soil.

2.
Int J Mol Sci ; 25(7)2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38612477

RESUMO

Cell division cycle 23 (CDC23) is a component of the tetratricopeptide repeat (TPR) subunit in the anaphase-promoting complex or cyclosome (APC/C) complex, which participates in the regulation of mitosis in eukaryotes. However, the regulatory model and mechanism by which the CDC23 gene regulates muscle production in pigs are largely unknown. In this study, we investigated the expression of CDC23 in pigs, and the results indicated that CDC23 is widely expressed in various tissues and organs. In vitro cell experiments have demonstrated that CDC23 promotes the proliferation of myoblasts, as well as significantly positively regulating the differentiation of skeletal muscle satellite cells. In addition, Gene Set Enrichment Analysis (GSEA) revealed a significant downregulation of the cell cycle pathway during the differentiation process of skeletal muscle satellite cells. The protein-protein interaction (PPI) network showed a high degree of interaction between genes related to the cell cycle pathway and CDC23. Subsequently, in differentiated myocytes induced after overexpression of CDC23, the level of CDC23 exhibited a significant negative correlation with the expression of key factors in the cell cycle pathway, suggesting that CDC23 may be involved in the inhibition of the cell cycle signaling pathway in order to promote the differentiation process. In summary, we preliminarily determined the function of CDC23 with the aim of providing new insights into molecular regulation during porcine skeletal muscle development.


Assuntos
Músculo Esquelético , Células Satélites de Músculo Esquelético , Animais , Ciclossomo-Complexo Promotor de Anáfase , Células Musculares , Suínos
3.
Nat Prod Bioprospect ; 14(1): 23, 2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38517590

RESUMO

In this study, two new kaurane diterpenes (16, 17), together with 12 lignans (1-12), a triterpene (15), and two other compounds (13, 14) were isolated from the woods of Agathis dammara. The structure of the new compound was determined by HR ESIMS and 1D/2D NMR spectroscopy, and its absolute configuration was determined by electronic circular dichroism (ECD) exciton chirality method. Compounds 5, 11, 14 exhibit significant hypoglycaemic activity in zebrafish, and their mechanism of action is to enhance glucose uptake in zebrafish.

4.
Nat Commun ; 15(1): 150, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38167842

RESUMO

Metal carbido complexes bearing single-carbon-atom ligand such as nitrogenase provide ideal models of adsorbed carbon atoms in heterogeneous catalysis. Trimetallic µ3-carbido clusterfullerenes found recently represent the simplest metal carbido complexes with the ligands being only carbon atoms, but only few are crystallographically characterized, and its formation prerequisite is unclear. Herein, we synthesize and isolate three vanadium-based µ3-CCFs featuring V = C double bonds and high valence state of V (+4), including VSc2C@Ih(7)-C80, VSc2C@D5h(6)-C80 and VSc2C@D3h(5)-C78. Based on a systematic theoretical study of all reported µ3-carbido clusterfullerenes, we further propose a supplemental Octet Rule, i.e., an eight-electron configuration of the µ3-carbido ligand is needed for stabilization of metal carbido clusters within µ3-carbido clusterfullerenes. Distinct from the classic Effective Atomic Number rule based on valence electron count of metal proposed in the 1920s, this rule counts the valence electrons of the single-carbon-atom ligand, and offers a general rule governing the stabilities of µ3-carbido clusterfullerenes.

5.
Anim Reprod ; 20(4): e20230040, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38074942

RESUMO

GnRH analogues were widely used for controlld ovary stimulation, but their effects on oocyte quality remain contradictory. This study aimed to explore the influence of GnRH analogues on oocyte quality in mice. A total of 120 mice were randomly assigned to four groups:(i)GnRH-a+PMSG group; (ii) GnRH-ant+PMSG group; (iii) PMSG group; (iv) Control group. Ovaries were collected for quantitative real-time polymerase chain reaction (qRT-PCR) to assess GDF9 and BMP15 mRNA expression, and protein expression were evaluated by western blotting. Moreover, embryo developmental progress in vitro and implantation rate in vivo were recorded. Compared with control group, both GDF9 mRNA and protein expressions were strengthened in PMSG group, but reduced in the presence of GnRH-a or GnRH-ant. The GnRH-a group exhibited decreased BMP15 mRNA expression compared to PMSG group, while the GnRH-ant group did not show the same pattern. BMP15 protein expression were not statisticlly different among the four groups. Notably, there was no statistically difference in the expression of these two factors between GnRH-a and GnRH-ant groups. The percentage of zygotes progressing to the 2-cell stage and percentage of 2-cell advancing to the blastocyst stage were similar in the PMSG group and control group. However, both the GnRH-a and GnRH-ant groups showed decreased embryos development rates compared to other two groups. The embryonic implantation rate in control group (53.3%) was higher than that in the GnRH-a and GnRH-ant groups (33.3% and 30.8%, P<0.05). The difference between the PMSG (45.0%) and GnRHa group was statistically significant (P value of 0.023), but not between the PMSG and GnRH-ant group (P value of 0.486). No statistical difference was confirmed between GnRH-a and GnRH-ant groups. Our findings shed light on the safety of GnRH analogues in ovary stimulation, and highlight the need for further research to establish optimal and effective controlled ovary stimulation protocol.

6.
Epigenetics ; 18(1): 2237789, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37506369

RESUMO

Long non-coding RNAs (lncRNAs) are involved in the process of muscle cell differentiation and play an important role. Previous studies have shown that lncRNA-MEG3 promotes the differentiation of porcine skeletal muscle satellite cells (PSCs), but the regulatory mechanism of MEG3 interaction with target protein has not been well studied. We demonstrated that MEG3 can bind dihydrolipoamide succinyltransferase (DLST) by RNA pull down and RIP-qPCR. Subsequently, knockdown and overexpression experiments showed that DLST promotes PSCs differentiation. Rescue experiments showed that the expression of DLST protein was significantly increased with MEG3 overexpression and decreased with MEG3 knockdown, while its mRNA expression was not changed. Furthermore, we have successfully predicted and validated that the transcription factor myogenic differentiation (MYOD) binds to the MEG3 core promoter though utilizing chromatin immunoprecipitation (CHIP) and luciferase reporter assays. The results indicated that MYOD acts as a transcription factor of MEG3 to promote MEG3 transcription. Knockdown of MEG3 in vivo indicated that MEG3 is involved in skeletal muscle regeneration. It is concluded that MYOD acts as a transcription factor to induce MEG3 expression. MEG3 acts as a molecular scaffold to bind and promote DLST protein expression. This paper provides a new molecular mechanism for MEG3 to promote the differentiation of PSCs.


Assuntos
Proteína MyoD , RNA Longo não Codificante , Células Satélites de Músculo Esquelético , Animais , Diferenciação Celular/genética , Metilação de DNA , Proteína MyoD/genética , Proteína MyoD/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Células Satélites de Músculo Esquelético/metabolismo , Suínos , Fatores de Transcrição/genética
7.
J Am Chem Soc ; 145(30): 16778-16786, 2023 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-37406618

RESUMO

Endohedral metallofullerenes (EMFs) are sub-nano carbon materials with diverse applications, yet their formation mechanism, particularly for metastable isomers, remains ambiguous. The current theoretical methods focus mainly on the most stable isomers, leading to limited predictability of metastable ones due to their low stabilities and yields. Herein, we report the successful isolation and characterization of two metastable EMFs, Sc2C2@C1(39656)-C82 and Sc2C2@C1(51383)-C84, which violate the isolated pentagon rule (IPR). These two non-IPR EMFs exhibit a rare case of planar and pennant-like Sc2C2 clusters, which can be considered hybrids of the common butterfly-shaped and linear configurations. More importantly, the theoretical results reveal that despite being metastable, these two non-IPR EMFs survived as the products from their most stable precursors, Sc2C2@C2v(5)-C80 and Sc2C2@Cs(6)-C82, via a C2 insertion during the post-formation annealing stages. We propose a systematic theoretical method for predicting metastable EMFs during the post-formation stages. The unambiguous molecular-level structural evidence, combined with the theoretical calculation results, provides valuable insights into the formation mechanisms of EMFs, shedding light on the potential of post-formation mechanisms as a promising approach for EMF synthesis.

8.
J Phys Chem Lett ; 14(22): 5163-5171, 2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37253105

RESUMO

Surface-enhanced Raman spectroscopy (SERS) has been widely applied in the identification and characterization of DNA structures with high efficiency. Especially, the SERS signals of the adenine group have exhibited high detection sensitivity in several biomolecular systems. However, there is still no unanimous conclusion regarding the interpretation of some special kinds of SERS signals of adenine and its derivatives on silver colloids and electrodes. This Letter presents a new photochemical azo coupling reaction for adenyl residues, in which the adenine is selectively oxidized to (E)-1,2-di(7H-purin-6-yl) diazene (azopurine) in the presence of silver ions, silver colloids, and electrodes of nanostructures under visible light irradiation. The product, azopurine, is first found to be responsible for the SERS signals. This photoelectrochemical oxidative coupling reaction of adenine and its derivatives is promoted by plasmon-mediated hot holes and is regulated by positive potentials and pH of solutions, which opens up new avenues for studying azo coupling in the photoelectrochemistry of adenine-containing biomolecules on electrode surfaces of plasmonic metal nanostructures.

9.
Anim Biosci ; 36(9): 1336-1349, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37170506

RESUMO

OBJECTIVE: The study was conducted to screen differentially expressed miRNAs in sows at early pregnancy by high-throughput sequencing and explore its mechanism of action on embryo implantation. METHODS: The blood serum of pregnant and non-pregnant Landrace×Yorkshire sows were collected 14 days after artificial insemination, and exosomal miRNAs were purified for high throughput miRNA sequencing. The expression patterns of 10 differentially expressed (DE) miRNAs were validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The qRT-PCR quantified the abundance of serum exosomal miR-192 in pregnant and control sows, and the diagnostic power was assessed by receiver operating characteristic (ROC) analysis. The target genes of DE miRNAs were predicted with bioinformatics software, and the functional and pathway enrichment analysis was performed on gene ontology and the Kyoto encyclopedia of genes and genomes terms. Furthermore, a luciferase reporter system was used to identify the target relation between miR-192 and integrin alpha 4 (ITGA4), a gene influencing embryo implantation in pigs. Finally, the expression levels of miRNAs and the target gene ITGA4 were analyzed by qRT-PCR, and western blot, with the proliferation of BeWo cells detected by cell counting kit-8 (CCK-8). RESULTS: A total of 221 known miRNAs were detected in the libraries of the pregnant and non-pregnant sows, of which 55 were up-regulated and 67 were down-regulated in the pregnant individuals compared with the non-pregnant controls. From these, the expression patterns of 10 DE miRNAs were validated. The qRT-PCR analysis further confirmed a significantly higher expression of miR-192 in the serum exosomes extracted from pregnant sows, when compared to controls. The ROC analysis revealed that miR-192 provided excellent diagnostic accuracy for pregnancy (area under the ROC curve [AUC] = 0.843; p>0.001). The dual-luciferase reporter assay indicated that miR-192 directly targeted ITGA4. The protein expression of ITGA4 was reduced in cells that overexpressed miR-192. Overexpression of miR-192 resulted in the decreased proliferation of BeWo cells and regulated the expression of cell cycle-related genes. CONCLUSION: Serum exosomal miR-192 could serve as a potential biomarker for early pregnancy in pigs. miR-192 targeted ITGA4 gene directly, and miR-192 can regulate cellular proliferation.

10.
Int J Mol Sci ; 24(7)2023 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-37047747

RESUMO

Myogenic differentiation is a complex biological process that is regulated by multiple factors, among which long noncoding RNAs (lncRNAs) play an essential role. However, in-depth studies on the regulatory mechanisms of long noncoding RNAs (lncRNAs) in myogenic differentiation are limited. In this study, we characterized the role of the novel lncRNA TCONS_00323213, which is upregulated during porcine skeletal muscle satellite cell (PSC) differentiation in myogenesis. We found that TCONS_00323213 affected the proliferation and differentiation of PSC in vitro. We performed quantitative polymerase chain reaction (qPCR), 5-ethynyl-20-deoxyuridine (EdU), western blotting, immunofluorescence staining, pull-down assays, and cleavage under targets and tagmentation (CUT and Tag) assays to clarify the effects and action mechanisms of TCONS_00323213. LncRNA TCONS_00323213 inhibited myoblast proliferation based on analyses of cell survival rates during PSC proliferation. Functional analyses revealed that TCONS_00323213 promotes cell differentiation and enhances myogenin (MyoG), myosin heavy chain (MyHC), and myocyte enhancer factor 2 (MEF2C) during myoblast differentiation. As determined by pull-down and RNA immunoprecipitation (RIP) assays, the lncRNA TCONS_00323213 interacted with PBX/Knotted Homeobox 2 (PKNOX2). CUT and Tag assays showed that PKNOX2 was significantly enriched on the MyoG promoter after lncRNA TCONS_00323213 knockdown. Our findings demonstrate that the interaction between lncRNA TCONS_00323213 and PKNOX2 relieves the inhibitory effect of PKNOX2 on the MyoG promoter, increases its expression, and promotes PSC differentiation. This novel role of lncRNA TCONS_00323213 sheds light on the molecular mechanisms by which lncRNAs regulate porcine myogenesis.


Assuntos
Desenvolvimento Muscular , RNA Longo não Codificante , Células Satélites de Músculo Esquelético , RNA Longo não Codificante/genética , RNA Longo não Codificante/fisiologia , Desenvolvimento Muscular/genética , Diferenciação Celular/genética , Células Satélites de Músculo Esquelético/citologia , Células Satélites de Músculo Esquelético/fisiologia , Animais , Suínos , Miogenina/genética , Miogenina/metabolismo , Cadeias Pesadas de Miosina/genética , Cadeias Pesadas de Miosina/metabolismo , Fatores de Transcrição MEF2/genética , Fatores de Transcrição MEF2/metabolismo , Técnicas de Silenciamento de Genes
11.
Exp Hematol Oncol ; 12(1): 38, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-37061723

RESUMO

BACKGROUND: Sustained activation of hepatocyte growth factor (HGF)/c-MET signaling is a major driver of hepatocellular carcinoma (HCC) progression, but underlying mechanism is unclear. ArfGAP With SH3 Domain, Ankyrin Repeat And PH Domain 2 (ASAP2) can reportedly activate GTPases and promote receptor tyrosine kinase signaling. However, the exact role of ASAP2 in HCC, especially for c-MET activation, also remains elusive. METHODS: ASAP2 expression levels in HCC tissues and cells were quantified using qRT-PCR, western blot (WB) analysis, and immunohistochemistry staining. Cell counting kit-8 (CCK-8) and colony formation assays were performed to evaluate cell proliferation rates. Flow cytometry assays were conducted to assess apoptosis rates. Wound healing and Transwell assays were performed to determine cell migration and invasion capacities. Epithelial-mesenchymal transition (EMT)-related marker expression levels were also examined. Subcutaneous implantation and tail vein injection models were applied for in vivo growth and metastasis evaluations, respectively. Bioinformatics analyses of The Cancer Genome Atlas and STRING datasets were performed to explore ASAP2 downstream signaling. Co-immunoprecipitation and Cycloheximide chasing experiments were performed to assess protein-protein interactions and protein half-life, respectively. RESULTS: ASAP2 had higher expression levels in HCC tissues than in normal liver, and also predicted poor prognosis. Knocking down ASAP2 significantly impaired cell proliferation, migration, and invasion capacities, but promoted apoptosis in HCC cells in vitro. However, overexpression of ASAP2 achieved the opposite effects. In vivo experiments confirmed that ASAP2 could promote HCC cell growth and facilitate lung metastasis. Interestingly, ASAP2 was essential for triggering EMT. Gene Set Enrichment Analysis demonstrated that c-MET signaling was greatly enriched in ASAP2-high HCC cases. Additionally, c-MET signaling activity was significantly decreased following ASAP knockdown, evidenced by reduced c-MET, p-AKT, and p-ERK1/2 protein levels. Importantly, ASAP2 knockdown effectively attenuated HGF/c-MET signaling-induced malignant phenotypes. c-MET and ASAP2 expression levels were positively correlated in our cohort. Mechanistically, ASAP2 can directly bind to CIN85, thereby disrupting its interaction with c-MET, and can thus antagonize CIN85-induced c-MET internalization and lysosome-mediated degradation. Notably, knocking down CIN85 can rescue the observed inhibitory effects caused by ASAP2 knockdown. CONCLUSIONS: This study highlights the importance of ASAP2 in sustaining c-MET signaling, which can facilitate HCC progression.

12.
Mol Biol Rep ; 50(5): 4273-4284, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36914869

RESUMO

INTRODUCTION: MicroRNAs (miRNAs)-a class of small endogenous non-coding RNAs-are widely involved in post-transcriptional gene regulation of numerous physiological processes. High-throughput sequencing revealed that the miR-192 expression level appeared to be significantly higher in the blood exosomes of sows at early gestation than that in non-pregnant sows. Furthermore, miR-192 was hypothesized to have a regulatory role in embryo implantation; however, the target genes involved in exerting the regulatory function of miR-192 required further elucidation. METHODS: In the present study, potential target genes of miR-192 in porcine endometrial epithelial cells (PEECs) were identified through biotin-labeled miRNA pull-down; functional and pathway enrichment analysis was performed via gene ontology analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment. Bioinformatic analyses were concurrently used to predict the potential target genes associated with sow embryo implantation. In addition, double luciferase reporter vectors, reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR), and Western blot were performed to verify the targeting and regulatory roles of the abovementioned target genes. RESULTS: A total of 1688 differentially expressed mRNAs were identified via miRNA pull-down. Through RT-qPCR, the accuracy of the sequencing data was verified. In the bioinformatics analysis, potential target genes of miR-192 appeared to form a dense inter-regulatory network and regulated multiple signaling pathways, such as metabolic pathways and the PI3K-Akt, MAPKs, and mTOR signaling pathways, that are relevant to the mammalian embryo implantation process. In addition, CSK (C-terminal Src kinase) and YY1 (Yin-Yang-1) were predicted to be potential candidates, and we validated that miR-192 directly targets and suppresses the expression of the CSK and YY1 genes. CONCLUSION: We screened 1688 potential target genes of miR-192 were screened, and CSK and YY1 were identified as miR-192 target genes. The outcomes of the present study provide novel insights into the regulatory mechanism of porcine embryo implantation and the identification of miRNA target genes.


Assuntos
Endométrio , MicroRNAs , Animais , Feminino , Células Epiteliais/metabolismo , Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Mamíferos/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , RNA Mensageiro/genética , Transdução de Sinais/genética , Suínos/genética , Endométrio/metabolismo
13.
Medicine (Baltimore) ; 101(50): e31841, 2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-36550804

RESUMO

BACKGROUND: Knee osteoarthritis (KOA) is a chronic musculoskeletal disease affecting the entire joint. Exercise therapy is the core treatment plan for non-surgical treatment of KOA, and tele-rehabilitation is also applied to KOA, but there is a lack of research on the comparison of pain and function recovery between different exercise methods combined Internet respectively. The study aims to compare the effects of power cycling and quadriceps training combined with online guidance separately on KOA mitigation of pain, recovery of function, quality of life, and adherence of participants in the community, compared to the control group. METHODS: This study is a single-blind, 12-week parallel randomized controlled trial. Seventy-two participants aged ≥ 50 years with KOA will be randomized into either the power cycling group, the quadriceps group or the control group. The intervention will be performed three times per week during 12 weeks. Outcome measures will be assessed at baseline, and at 4, 8, and 12 weeks after allocation. The primary outcome will be self-reported pain, assessed with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale. Secondary outcomes will include mitigation of knee pain, quality of life, improvement of functional physical performance, adherence of participants. DISCUSSION: By summarizing the study's strengths and limitations, this trial results may guide tele-rehabilitation of KOA in the community.Trial registration: The study was registered in the clinical trial registry ChiCTR2200059255, 27/04/2022.


Assuntos
Osteoartrite do Joelho , Humanos , Osteoartrite do Joelho/tratamento farmacológico , Qualidade de Vida , Método Simples-Cego , Articulação do Joelho , Dor , Terapia por Exercício/métodos , Resultado do Tratamento , Ensaios Clínicos Controlados Aleatórios como Assunto
14.
J Am Chem Soc ; 144(47): 21587-21595, 2022 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-36354144

RESUMO

Azafullerenes derived from nitrogen substitution of carbon cage atoms render direct modifications of the cage skeleton, electronic, and physicochemical properties of fullerene. Gas-phase ionized monometallic endohedral azafullerene (MEAF) [La@C81N]+ formed via fragmentation of a La@C82 monoadduct was detected in 1999, but the pristine MEAF has never been synthesized. Here, we report the synthesis, isolation, and characterization of the first pristine MEAF La@C81N, tackling the two-decade challenge. Single-crystal X-ray diffraction study reveals that La@C81N has an 82-atom cage with a pseudo C3v(8) symmetry. According to DFT computations, the nitrogen substitution site within the C82 cage is proposed to locate at a hexagon/hexagon/pentagon junction far away from the encapsulated La atom. La@C81N exists in stable monomer form with a closed-shell electronic state, which is drastically different from the open-shell electronic state of the original La@C82. Our breakthrough in synthesizing a new type of azafullerene offers a new insight into the skeletal modification of fullerenes.

15.
Anal Chem ; 94(40): 13719-13727, 2022 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-36173369

RESUMO

Based on the Venturi self-pumping effect, real-time sniffing with mass spectrometry (R-sniffing MS) is developed as a tool for direct and real-time mass spectrometric analysis of both gaseous and solid samples. It is capable of dual-mode operation in either gaseous or solid phase, with the corresponding techniques termed as Rg-sniffing MS and Rs-sniffing MS, respectively. In its gaseous mode, Rg-sniffing MS is capable of analyzing a gaseous mixture with response time (0.8-2.1 s rise time and 7.3-9.6 s fall time), spatial resolution (<80 µm), three-dimensional diffusion imaging, and aroma distribution imaging of red pepper. In its solid mode, an appropriate solvent droplet desorbs the sample from a solid surface, followed by the aspiration of the mixture using the Venturi self-pumping effect into the mass spectrometer, wherein it is ionized by a standard ion source. Compared with the desorption electrospray ionization (DESI) technique, Rs-sniffing MS demonstrated considerably improved limit of detection (LOD) values for arginine (0.07 µg/cm2 Rs-sniffing vs 1.47 µg/cm2 DESI), thymopentin (0.10 µg/cm2 vs 2.67 µg/cm2), and bacitracin (0.16 µg/cm2 vs 2.28 µg/cm2). Rs-sniffing is applicable for the detection of C60(OCH3)6Cl-, an intermediate in the methoxylation reaction involving C60Cl6 (solid) and methanol (liquid). The convenient and highly sensitive R-sniffing MS has a characteristic separation of desorption from the ionization process, in which the matrix atmosphere of desorption can be interfaced by a pipe channel and self-pumped by the Venturi effect with consequent integration using a standard ion source. The R-sniffing MS operates in a voltage-, heat-, and vibration-free environment, wherein the analyte is ionized by a standard ion source. Consequently, a wide range of samples can be analyzed simultaneously by the R-sniffing MS technique, regardless of their physical state.


Assuntos
Gases , Espectrometria de Massas por Ionização por Electrospray , Arginina , Bacitracina , Metanol , Solventes , Espectrometria de Massas por Ionização por Electrospray/métodos , Timopentina
16.
ACS Omega ; 7(35): 31442-31447, 2022 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-36092566

RESUMO

A molecular tweezer trans-di(perylene-3-ylmethanaminobenzo)-18-crown-6 (DP-18C6) incorporating two perylene subunits in a single crown ether core was designed and synthesized as a host for fullerenes. Through the cooperative effect of the perylene subunits and the crown ether moiety, DP-18C6 can efficiently recognize fullerenes including C60, C70, and C76. 1H NMR titration and fluorescence titration experiments demonstrated that DP-18C6 can effectively grasp the fullerene molecule to form a 1:1 host-guest complex. Density functional theory calculations revealed the presence of intermolecular π-π interactions between the perylene subunits of DP-18C6 and the fullerene molecule. More importantly, DP-18C6 exhibited remarkably high binding selectivity for higher fullerenes over C60, revealing potential application for the separation of fullerenes by means of host-guest interactions.

17.
Nanomaterials (Basel) ; 12(18)2022 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-36144875

RESUMO

In the flames during low-pressure combustion, not only a rich variety of fullerenes but also many reactive intermediates can be produced (e.g., carbene, CH2) that are short-lived and cannot be stabilized directly under normal circumstances. These intermediates can be captured by fullerene carbon cages for stabilization. In this paper, three C71H2 isomers were synthesized in situ in low-pressure benzene-acetylene-oxygen diffusion flame combustion. The results, which were unambiguously characterized by single-crystal X-ray diffraction, show that the three isomers are carbene addition products of D5h-C70 on different sites. The relative energies and stability of different C71H2 isomers are revealed by Ultraviolet-Visible (UV-Vis) absorption spectroscopy, in combination with theoretical calculations, in this work. Both the in situ capture and theoretical study of these C71H2 isomers in low-pressure combustion will provide more information regarding carbene additions to other fullerenes or other carbon clusters at high temperatures.

18.
Proc Natl Acad Sci U S A ; 119(39): e2202563119, 2022 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-36122234

RESUMO

Hundreds of members have been synthesized and versatile applications have been promised for endofullerenes (EFs) in the past 30 y. However, the formation mechanism of EFs is still a long-standing puzzle to chemists, especially the mechanism of embedding clusters into charged carbon cages. Here, based on synthesis and structures of two representative vanadium-scandium-carbido/carbide EFs, VSc2C@Ih (7)-C80 and VSc2C2@Ih (7)-C80, a reasonable mechanism-C1 implantation (a carbon atom is implanted into carbon cage)-is proposed to interpret the evolution from VSc2C carbido to VSc2C2 carbide cluster. Supported by theoretical calculations together with crystallographic characterization, the single electron on vanadium (V) in VSc2C@Ih (7)-C80 is proved to facilitate the C1 implantation. While the V=C double bond is identified for VSc2C@Ih (7)-C80, after C1 implantation the distance between V and C atoms in VSc2C2@Ih (7)-C80 falls into the range of single bond lengths as previously shown in typical V-based organometallic complexes. This work exemplifies in situ self-driven implantation of an outer carbon atom into a charged carbon cage, which is different from previous heterogeneous implantation of nonmetal atoms (Group-V or -VIII atoms) driven by high-energy ion bombardment or high-pressure offline, and the proposed C1 implantation mechanism represents a heretofore unknown metal-carbon cluster encapsulation mechanism and can be the fundamental basis for EF family genesis.

19.
Chem Commun (Camb) ; 58(70): 9814-9817, 2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-35975480

RESUMO

A double-heptagon-containing C70H6 (dihept-C70H6) was isolated and unambiguously characterized in the soot of low-pressure combustion, which shares the identical heptagonal cage as dihept-C70Cl6 previously identified in the products of carbon arc, and thus represents the first nonclassical fullerene isolable in both carbon arc and combustion.

20.
Nanomaterials (Basel) ; 12(15)2022 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-35893515

RESUMO

Unlike traditional small molecule drugs, fullerene is an all-carbon nanomolecule with a spherical cage structure. Fullerene exhibits high levels of antiviral activity, inhibiting virus replication in vitro and in vivo. In this review, we systematically summarize the latest research regarding the different types of fullerenes investigated in antiviral studies. We discuss the unique structural advantage of fullerenes, present diverse modification strategies based on the addition of various functional groups, assess the effect of structural differences on antiviral activity, and describe the possible antiviral mechanism. Finally, we discuss the prospective development of fullerenes as antiviral drugs.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...