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1.
Biomed Environ Sci ; 37(9): 1015-1029, 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39401995

RESUMO

Objective: This study investigated the epidemic characteristics and spatio-temporal dynamics of hemorrhagic fever with renal syndrome (HFRS) in Qingdao City, China. Methods: Information was collected on HFRS cases in Qingdao City from 2010 to 2022. Descriptive epidemiologic, seasonal decomposition, spatial autocorrelation, and spatio-temporal cluster analyses were performed. Results: A total of 2,220 patients with HFRS were reported over the study period, with an average annual incidence of 1.89/100,000 and a case fatality rate of 2.52%. The male:female ratio was 2.8:1. 75.3% of patients were aged between 16 and 60 years old, 75.3% of patients were farmers, and 11.6% had both "three red" and "three pain" symptoms. The HFRS epidemic showed two-peak seasonality: the primary fall-winter peak and the minor spring peak. The HFRS epidemic presented highly spatially heterogeneous, street/township-level hot spots that were mostly distributed in Huangdao, Pingdu, and Jiaozhou. The spatio-temporal cluster analysis revealed three cluster areas in Qingdao City that were located in the south of Huangdao District during the fall-winter peak. Conclusion: The distribution of HFRS in Qingdao exhibited periodic, seasonal, and regional characteristics, with high spatial clustering heterogeneity. The typical symptoms of "three red" and "three pain" in patients with HFRS were not obvious.


Assuntos
Epidemias , Febre Hemorrágica com Síndrome Renal , Estações do Ano , Análise Espaço-Temporal , Humanos , China/epidemiologia , Masculino , Feminino , Adulto , Adolescente , Pessoa de Meia-Idade , Adulto Jovem , Febre Hemorrágica com Síndrome Renal/epidemiologia , Incidência , Cidades/epidemiologia , Idoso , Criança , Análise por Conglomerados
2.
Sci Data ; 11(1): 799, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39025902

RESUMO

Callosobruchus maculatus is one of the most competitive stored grain pests, which causes a great loss to agricultural economy. However, due to an inadequacy of high-quality reference genome, the molecular mechanisms for olfactory and hypoxic adaptations to stored environments are unknown and require to be revealed urgently, which will contribute to the detection and prevention of the invasive pests C. maculatus. Here, we presented a high-quality chromosome-level genome of C. maculatus based on Illumina, Nanopore and Hi-C sequencing data. The total size was 1.2 Gb, and 65.17% (797.47 Mb) of it was identified to be repeat sequences. Among assembled chromosomes, chromosome 10 was considered the X chromosome according to the evidence of reads coverage and homologous genes among species. The current version of high-quality genome provides preferable data resources for the adaptive evolution research of C. maculatus.


Assuntos
Besouros , Genoma de Inseto , Animais , Besouros/genética
3.
Nat Prod Res ; : 1-7, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38752874

RESUMO

Two new withanolides named physaminilides L (1) and M (2), together with four known ones (3-6) were isolated from the Physalis minima L. The structures were established by analysis of the HR ESIMS, IR and NMR spectroscopic data. The absolute configurations were determined through NOESY and ECD spectra. For compounds 1-5 assayed at 20 µM and compound 6 at 10 µM, inhibition rates of hepatic fibrosis were 22.19%, 15.29%, 37.07%, 9.27%, 12.45%, and 37.03%, respectively.

4.
J Ethnopharmacol ; 325: 117830, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38301983

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Physalis angulata L., a traditional Chinese medicine called "Kuzhi" in China, was used traditionally to treat liver diseases (eg. icterus, hepatitis) as well as malaria, asthma, and rheumatism. AIM OF THE STUDY: Our study aimed to investigate the withanolides with anti-hepatic fibrosis effect from P. angulate. MATERIALS AND METHODS: Withanolides were obtained from the EtOH extract of P. angulate by bioassay-molecular networking analysis-guided isolation using column chromatography and normal/reversed-phase semipreparative HPLC. The structures of new withanolides were elucidated by combinations of spectroscopic techniques with NMR and ECD calculations. MTT cell viability assay, AO/EB staining method, cell wound healing assay, ELISA and Western blot experiments were employed to evaluate the anti-hepatic fibrosis activity and to uncover related mechanism. Molecular docking analysis and cellular thermal shift assay were used to evaluate and verify the interaction between the active withanolides and their potential targets. RESULTS: Eight unreported withanolides, withagulides A-H (1-8), along with twenty-eight known ones were obtained from P. angulate. Withanolides 6, 9, 10, 24, 27, and 29-32 showed marked anti-hepatic fibrosis effect with COL1A1 expression inhibition above 50 %. Physalin F (9), the main component in the active fraction, significantly decreased the TGF ß1-stimulated expressions of collagen I and α-SMA in LX-2 cells. Mechanism study revealed that physalin F exerted its anti-hepatic fibrosis effect via the PI3K/AKT/mTOR signaling pathway. CONCLUSION: This study suggested that withanolides were an important class of natural products with marked anti-hepatic fibrosis effect. The main withanolide physalin F might be a promising candidate for hepatic fibrosis treatment. The work provided experimental foundation for the use of P. angulate to treat hepatic fibrosis.


Assuntos
Physalis , Vitanolídeos , Vitanolídeos/farmacologia , Vitanolídeos/uso terapêutico , Vitanolídeos/química , Physalis/química , Simulação de Acoplamento Molecular , Fosfatidilinositol 3-Quinases , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/tratamento farmacológico , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Extratos Vegetais/química
5.
Molecules ; 29(2)2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38257331

RESUMO

Liver fibrosis is the initial pathological process of many chronic liver diseases. Targeting hepatic stellate cell (HSC) activation is an available strategy for the therapy of liver fibrosis. We aimed to explore the anti-liver fibrosis activity and potential mechanism of phomopsterone B (PB) in human HSCs. The results showed that PB effectively attenuated the proliferation of TGF-ß1-stimulated LX-2 cells in a concentration-dependent manner at doses of 1, 2, and 4 µM. Quantitative real-time PCR and Western blot assays displayed that PB significantly reduced the expression levels of α-SMA and collagen I/III. AO/EB and Hoechst33342 staining and flow cytometry assays exhibited that PB promoted the cells' apoptosis. Meanwhile, PB diminished the number of autophagic vesicles and vacuolated structures, and the LC3B fluorescent spots indicated that PB could effectively inhibit the accretion of autophagosomes in LX-2 cells. Moreover, rapamycin and MHY1485 were utilized to further investigate the effect of mTOR in autophagy and apoptosis. The results demonstrated that PB regulated autophagy and apoptosis via the mTOR-dependent pathway in LX-2 cells. In summary, this is the first evidence that PB effectively alleviates liver fibrosis in TGF-ß1-stimulated LX-2 cells, and PB may be a promising candidate for the prevention of liver fibrosis.


Assuntos
Autofagia , Fator de Crescimento Transformador beta1 , Humanos , Cirrose Hepática/tratamento farmacológico , Autofagossomos , Apoptose
6.
World J Clin Cases ; 11(32): 7865-7871, 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-38073688

RESUMO

BACKGROUND: Abernethy malformation, also known as congenital extrahepatic portosystemic shunt, is an uncommon malformation resulting from aberrant development of the portal venous system. Cystic fibrosis (CF) is an autosomal recessive genetic disease caused by mutations in the CFTR gene. It mainly affects the exocrine glands of the respiratory, digestive and reproductive systems. It is considered extremely rare in the Asian population. We present a clinical case involving a pediatric patient of Asian descent who was diagnosed with Abernethy malformation and CF. CASE SUMMARY: A 12-year-old girl presented with a medical history of recurring respiratory infections and hemoptysis, and chest computed tomography (CT) showed bronchiectasis. Whole exome sequencing was performed for the patient, yielding findings that revealed a compound heterozygous variant of the CFTR gene: c.233_c.234insT/p.Trp79fsTer3 (maternal origin); c.2909G>A/p.Gly970Asp (paternal origin). CF was diagnosed. The physician's attention was drawn to the presence of splenomegaly during disease progression. Abdominal enhanced CT revealed splenomegaly, compression of the left kidney, and multiple tortuous dilated vascular shadows were seen at the splenic hilum, which flowed back into the left renal vein and portal vein, suggesting Abernethy malformation type II. Intraoperatively, the abnormal blood flow was seen to merge into the inferior vena cava through the left renal vein without hepatic processing, and the pathology of liver biopsy showed hypoplastic, dilated or absent portal vein branches, both of which supported the diagnosis of Abernethy malformation type II. This represents the initial documented instance of Abernethy malformation accompanied by a CFTR gene mutation in the existing body of literature. CONCLUSION: Coexisting Abernethy malformation and CF are rare. Detailed medical history information, abdominal enhanced CT, venography and genetic testing contribute to diagnosis as well as differential diagnosis.

7.
Cancer Manag Res ; 15: 547-561, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37426392

RESUMO

Long non-coding RNAs (lncRNAs) are non-coding RNAs (ncRNAs) longer than 200nt. They have complex biological functions and take part in multiple fundamental biological processes, such as cell proliferation, differentiation, survival and apoptosis. Recent studies suggest that lncRNAs modulate critical regulatory proteins involved in cancer cell cycle, such as cyclin, cell cycle protein-dependent kinases (CDK) and cell cycle protein-dependent kinase inhibitors (CKI) through different mechanisms. To clarify the role of lncRNAs in the regulation of cell cycle will provide new ideas for design of antitumor therapies which intervene with the cell cycle progression. In this paper, we review the recent studies about the controlling of lncRNAs on cell cycle related proteins such as cyclin, CDK and CKI in different cancers. We further outline the different mechanisms involved in this regulation and describe the emerging role of cell cycle-related lncRNAs in cancer diagnosis and therapy.

8.
Plant Dis ; 107(12): 3825-3835, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37337445

RESUMO

Apple rust caused by Gymnosporangium yamadae is a significant disease in China's main apple production areas. We evaluated the effects of temperature, moisture, and ultraviolet (UV) light on the germination, infection, and survival of teliospore horns and basidiospores under artificially controlled environmental conditions. The temperature required for the germination and infection of teliospores and basidiospores of G. yamadae ranged from 5 to 25°C, with an optimum temperature of approximately 17°C. The teliospore horns germinated after soaking in distilled water for 5 min and required at least 2.3 h of development to produce basidiospores under the most favorable conditions. The basidiospores germinated only in free water and produced germ tubes 0.8 h after being placed in the water. The half-life of the basidiospore was 72.5 h in the dark and only 9.5 h when exposed to intense UV light. The basidiospores inoculated on the host leaves required at least 2.3 h of water exposure to cause rust lesions. A revised Weibull model could describe the relationships between the germination and infection of teliospore horns and basidiospores with temperature and wetness duration. Collectively, these results can serve as a valuable guide for developing a model to predict future apple rust epidemics and establish a method for effective control strategies.


Assuntos
Malus , Raios Ultravioleta , Temperatura , Germinação , Esporos Fúngicos , Água
9.
Sci Rep ; 13(1): 6888, 2023 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-37106016

RESUMO

Radix Astragali is one of the most famous and frequently used health food supplements and herbal medicines. Among more than 227 components of Radix Astragali, Astragaloside IV (AG IV) is famous functional compound and is commonly used as a quality marker for Radix Astragali. However, the relatively low content of AG IV in Radix Astragali (< 0.04%, w/w) severely limits its application. The purpose of this study is to improve the biotransformation of AG IV and its bioaccessibility during in vitro digestion by Poria cocos solid fermenting Radix Astragali. The optimum fermentation conditions were as follows: Inoculation amount 8 mL; fermentation time 10 d; fermentation humidity 90%. Through fermentation, the content of AG IV was increased from 384.73 to 1986.49 µg/g by 5.16-fold. After in vitro digestion, the contents of genistin, calycosin, formononetin, AG IV, Astragaloside II (AG II) and total flavonoids in fermented Radix Astragali (FRA) of enteric phase II (ENTII) were 34.52 µg/g, 207.32 µg/g, 56.76 µg/g, 2331.46 µg/g, 788.31 µg/g, 3.37 mg/g, which were 2.08-fold, 2.51-fold, 1.05-fold, 8.62-fold, 3.22-fold and 1.50-fold higher than those of control, respectively. The Scanning electron microscopy (SEM) of FRA showed rough surface and porous structure. The DPPH and ABTS radical scavenging rate of FRA were higher than those of control. These results showed that the Poria cocos solid fermentation could increase the content of the AG IV in Radix Astragali and improve the bioaccessibility and antioxidant activity of Radix Astragali, which is providing new ideas for future development and utilization of Radix Astragali.


Assuntos
Medicamentos de Ervas Chinesas , Wolfiporia , Antioxidantes , Fermentação , Medicamentos de Ervas Chinesas/química , Biotransformação , Digestão , Cromatografia Líquida de Alta Pressão/métodos
10.
J Hazard Mater ; 454: 131497, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37119574

RESUMO

Uranium is one of the most important radionuclides but could also cause potential health risks to human beings due to its radioactive and chemical toxicity. It is an urgent task to develop a simple but efficient sensing platform for UO22+, the main existing form of uranium in environment. Herein, a rhodamine-functionalized carbon dots (o-CDs-Rho) was synthesized and applied for UO22+ sensing through a simple but novel aggregation-enhanced FRET strategy. The weak FRET efficiency (16.2%) of o-CDs-Rho in dispersed solution is significantly enhanced (>77.2%) after UO22+ triggered aggregation due to the increased number of rhodamine acceptors around each CDs from dispersed 80 to aggregated 2800. This is the first ratiometric fluorescence sensor with an inverse change of fluorescence intensity at dual emission wavelengths under single-wavelength excitation for UO22+. Under optimized experiment conditions, o-CDs-Rho nanosensor shows a low detection limit of 53 nM and excellent selectivity. Meanwhile, the as-prepared nanosensor also shows high reliability and stability. These excellent properties make it successful in detecting uranium content in real samples.

11.
Nat Prod Res ; : 1-8, 2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36606546

RESUMO

The spirohydantoin-containing cucurbitane-type triterpenoid, kaguacidine A (1), was isolated and purified from 95% ethanol extract of vines of Momordica charantia L. (Cucurbitaceae). Its unprecedented chemical structure, a spirohydantoin substituent at C-23 of cucurbitane, was elucidated by extensive spectroscopic analyses, including HRESIMS, IR, optical rotation, 1 D- and 2 D-NMR spectra. The possible biosynthetic pathway is deduced and may be attributed to the metabolic activity of microbial symbionts in M. charantia L. Compound 1 was evaluated for anti-inflammatory activity against LPS-induced NO production in RAW 264.7 cells and anti-proliferative activity against four cancer cell lines, including HEp-2, MCF-7, Hep-G2, and WiDr. Compound 1 showed moderate anti-inflammatory activity with an IC50 value of 18.5 ± 0.4 µg/mL and weak anti-proliferative activity against MCF-7, HEp-2, Hep-G2, and WiDr with IC50 values of >40, 33.8 ± 0.6, 31.0 ± 0.7, and 27.0 ± 0.7 µM, respectively.

12.
Cancer Biother Radiopharm ; 38(9): 650-662, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35704039

RESUMO

Background: Bladder cancer (BLCA) is a malignant tumor occurring in bladder mucosa. Metadherin (MTDH) has been implicated in tumor progression; however, its molecular biological mechanisms in BLCA remain unclear. Materials and Methods: Cell functions were tested after BLCA cells were transfected by both short hairpin RNAs and small interfering RNAs to silence MTDH. Furthermore, in-house RNA sequencing (RNA-seq) was performed with T24 cells after the knockdown of MTDH. In addition, MTDH-related pathways were explored. Finally, MTDH mRNA and protein expression levels were examined using multiple detection methods in BLCA tissues. Results: MTDH knockdown could largely inhibit cell proliferation, viability, and migration and induce apoptosis of BLCA cells. In-house RNA-seq showed that MTDH knockdown led to extracellular matrix organization and cell division. The integrated analysis showed that the comprehensive expression of MTDH at the mRNA level was 0.47 and that at the protein level was 0.54, based on 11 platforms, including 1485 BLCA and 180 non-BLCA samples. Conclusions: MTDH promotes the growth of BLCA cells through the pathway of cell division. This study provides new directions and biomarkers for future treatment.


Assuntos
Neoplasias da Bexiga Urinária , Humanos , RNA Interferente Pequeno/genética , Neoplasias da Bexiga Urinária/genética , Divisão Celular , Proliferação de Células , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo
13.
Front Oncol ; 12: 1008856, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36263199

RESUMO

Long noncoding RNAs (lncRNAs), which lack protein-coding ability, can regulate cancer cell growth, proliferation, invasion, and metastasis. Tumor-associated macrophages (TAMs) are key components of the tumor microenvironment that have a significant impact on cancer progression. Small extracellular vesicles (sEV) are crucial mediators of intercellular communications. Cancer cell and macrophage-derived sEV can carry lncRNAs that influence the onset and progression of cancer. Dysregulation of lncRNAs, TAMs, and sEV is widely observed in tumors which makes them valuable targets for cancer immunotherapy. In this review, we summarize current updates on the interactions among sEV, lncRNAs, and TAMs in tumors and provide new perspectives on cancer diagnosis and treatment.

14.
Curr Med Sci ; 42(5): 1015-1021, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36057075

RESUMO

OBJECTIVE: Apatinib is a novel inhibitor of vascular endothelial growth factor receptor-2. The goal of this study was to evaluate overall survival (OS) after a combination of transarterial chemoembolization (TACE) and apatinib in patients with advanced hepatocellular carcinoma (HCC) and to identify the factors affecting patient survival. METHODS: Fifty-one patients with advanced HCC who received TACE in combination with apatinib in our hospital from June 2015 to May 2017 were enrolled. The OS and progression-free survival (PFS) were calculated using the Kaplan-Meier method. The log-rank test and Cox regression model were used to determine the factors affecting OS. RESULTS: The median OS and PFS of the patients were 15 months and 10 months, respectively. The 1-, 2-, and 3-year survival rates were 64.7%, 23.5%, and 1.8%, respectively. Univariate survival analysis showed that patients with Child-Pugh A (P=0.006), reduction rate of proper hepatic artery (P=0.016), hand-foot syndrome (P=0.005), secondary hypertension (P=0.050), and without ascites (P=0.010) had a better OS. Multivariate analysis showed that hand-foot syndrome (P=0.014), secondary hypertension (P=0.017), and reduction rate of proper hepatic artery (P=0.025) were independent predictors of better OS. CONCLUSION: TACE combined with apatinib is a promising treatment for advanced HCC. Hand-foot syndrome, secondary hypertension, and the reduction rate of proper hepatic artery were associated with a better OS.


Assuntos
Antineoplásicos , Carcinoma Hepatocelular , Quimioembolização Terapêutica , Síndrome Mão-Pé , Hipertensão , Neoplasias Hepáticas , Inibidores de Proteínas Quinases , Piridinas , Humanos , Antineoplásicos/uso terapêutico , Carcinoma Hepatocelular/tratamento farmacológico , Quimioembolização Terapêutica/métodos , Terapia Combinada , Síndrome Mão-Pé/terapia , Neoplasias Hepáticas/tratamento farmacológico , Prognóstico , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Piridinas/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico
16.
Front Med (Lausanne) ; 9: 828346, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35602511

RESUMO

Background: Uterine cervical neoplasms is widely concerned due to its high incidence rate. Early diagnosis is extremely important for prognosis. The purpose of this article is evaluating the efficacy of Raman spectroscopy in the diagnosis of suspected uterine cervical neoplasms. Methods: We searched PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of science up to September 1, 2021. By analyzing the true positive (TP), false positive (FP), true negative (TN) and false negative (FN) of six included study, we evaluated the pooled and grouping sensitivity, specificity, positive, and negative likelihood ratios (LR), and diagnostic odds ratio (DOR), with 95% confidence intervals (CI), based on random effects models. The overall diagnostic accuracy of Raman spectrum was evaluated by SROC curve analysis and AUC. Results: After screening with inclusion and exclusion criteria, a total of six study were included in the study. The pooled sensitivity and specificity was 0.98 (95% Cl, 0.93-0.99) and 0.95 (95% Cl, 0.89-0.98). The total PLR and NLR were 21.05 (95% CI, 8.23-53.86) and 0.03 (95% CI, 0.01-0.07), respectively. And the AUC of the SROC curve which show the overall diagnostic accuracy was 0.99 (0.98-1.00). Conclusion: Through analysis, we confirmed the role of Raman spectroscopy (RS) in the diagnosis of suspected uterine cervical tumors. Systematic Review Registration: [https://www.crd.york.ac.uk/prospero/], identifier [CRD42021284966].

17.
Arch Insect Biochem Physiol ; 111(1): e21898, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35434835

RESUMO

The three weevil species, Sternochetus gravis, S. mangiferae, and S. olivieri, have all been reported to be serious pests of mango fruits. Morphology, biology, and various management approaches of these economically important weevils have been well studied. However, no mitochondrial genomes have been reported from the genus Sternochetus. Herein, we assembled mitogenomes of all the three Sternochetus species to reveal their mitogenomic characteristics. A DNA library of 350 bp insert size was constructed and sequenced in Illumina's HiSeq 6000 platform with a pair-end 150 bp sequencing strategy by Novogene. The sequence reads were assembled using GetOrganelle v1.7.1 and the genes were annotated by Geneious Prime 2021.0.3 and MITOS Web Server. Coupled with 61 published mitogenomes from 13 subfamilies of Curculionidae, we reconstructed phylogenetic trees to resolve evolutionary relationships of these closely related species and also examined subfamily-level classification among Curculionidae. All three mitogenomes are double-stranded circular molecules with 22 transfer RNA genes, 13 protein-coding genes (PCGs), 2 ribosomal RNA genes, and 1 noncoding control region as in other insects. Higher interspecific nucleotide divergence (about 10%) of 13 PCGs indicated these three Sternochetus species diverged a long time ago. Phylogenetic analyses using both maximum likelihood and Bayesian inference methods showed that Sternochetus falls into the basal clade of Cryptorhynchini, a tribe in the subfamily Molytinae. The relationship of S. olivieri as a sister species to S. gravis + S. mangiferae was strongly supported. The monophyly of Cryptorhynchini was also well supported whereas Molytinae was suggested to be a polyphyletic group.


Assuntos
Besouros , Genoma Mitocondrial , Gorgulhos , Animais , Teorema de Bayes , Filogenia
18.
Chaos ; 32(2): 023125, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35232049

RESUMO

The threshold model has been widely adopted as a prototype for studying contagion processes on social networks. In this paper, we consider individual interactions in groups of three or more vertices and study the threshold model on hypergraphs. To understand how high-order interactions affect the breakdown of the system, we develop a theoretical framework based on generating function technology to derive the cascade condition and the giant component of vulnerable vertices, which depend on both hyperedges and hyperdegrees. First, we find a dual role of the hyperedge in propagation: when the average hyperdegree is small, increasing the size of the hyperedges may make the system fragile, while the average hyperdegree is relatively large, the increase of the hyperedges causes the system to be robust. Then, we identify the effects of threshold, hyperdegree, and hyperedge heterogeneities. The heterogeneity of individual thresholds causes the system to be more fragile, while the heterogeneity of individual hyperdegrees or hyperedges increases the robustness of the system. Finally, we show that the higher hyperdegree a vertex has, the larger possibility and faster speed it will get activated. We verify these results by simulating meme spreading on both random hypergraph models and hypergraphs constructed from empirical data.


Assuntos
Rede Social
19.
Food Chem X ; 14: 100286, 2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35330883

RESUMO

Four novel triterpene glycosides, taimordisins A-D (1-4), were discovered from fresh fruits of Taiwanese Momordica charantia. The chemical framework and relative stereochemistry of these four natural products were isolated, purified, and determined by using various separation and spectroscopy techniques. Each of them features a unique bicyclic-fused or trifuso-centro-fused ring system. Notably, 1 and 2 are cucurbitane-based compounds possessing a new C-24 and C-2″ carbon-carbon linkage with 5-hydroxy-2-(hydroxymethyl)tetrahydro-4H-pyran-4-one and 6-(hydroxymethyl)tetrahydro-4H-pyran-3,4,4-triol units, respectively, and represented an unprecedented molecular skeleton. In terms of biosynthesis, they all originate from a common precursor 3-hydroxycucurbita-5,24-dien-19-al-7,23-di-O-ß-glucopyranoside. Of two sugar moieties, the one at 23-O-ß-glucopyranoside grants each individual congener uniqueness likely through microbial symbiont-mediated intramolecular transformation into two major types of furo[2,3-b]pyranone and furo[3,2-c]pyranone derivatives. These new products possess desirable anti-inflammatory biological activities in addition to being generally regarded as safe.

20.
J Phys Chem A ; 126(1): 125-144, 2022 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-34935392

RESUMO

We report the results on the combustion of single, levitated droplets of exo-tetrahydrodicyclopentadiene (JP-10) doped with titanium-aluminum-boron (Ti-Al-B) reactive metal nanopowders (RMNPs) in an oxygen (60%)-argon (40%) atmosphere by exploiting an ultrasonic levitator with droplets ignited by a carbon dioxide laser. Ultraviolet-visible (UV-vis) emission spectroscopy revealed the presence of gas-phase aluminum (Al) and titanium (Ti) atoms. These atoms can be oxidized in the gas phase by molecular oxygen to form spectroscopically detected aluminum monoxide (AlO) and titanium monoxide (TiO) transients. Analysis of the optical ignition videos supports that the nanoparticles are ignited before JP-10. The detection of boron monoxide (BO) further proposes an active surface chemistry through the oxidation of the RMNPs and the release of at least BO into the gas phase. The oxidation of gas-phase BO by molecular oxygen to boron dioxide (BO2) plus atomic oxygen might operate in the gas phase, although the involvement of surface oxidation processes of RMNPs to BO2 cannot be discounted. The UV-vis emission spectra also revealed the key reactive intermediates (OH, CH, C2, and HCO) of the oxidation of JP-10. Electronic structure calculations reveal that the presence of reactive radicals has a profound impact on the oxidation of JP-10. Although titanium monoxide (TiO) reacts to produce titanium dioxide (TiO2), it does not engage in an active JP-10 chemistry as all abstraction pathways are endoergic by more than 217 kJ mol-1. This is similar for atomic aluminum and titanium, whose hydrogen abstraction reactions from JP-10 were revealed to be endoergic by at least 77 kJ mol-1. Therefore, aluminum and titanium react preferentially with molecular oxygen to produce their monoxides. However, the formation of BO, AlO, and BO2 supplies a pool of highly reactive radicals, which can abstract hydrogen from JP-10 via transition states ranging from only 1 to 5 kJ mol-1 above the separated reactants, forming JP-10 radicals along with the hydrogen abstraction products (boron hydride oxide, aluminum monohydroxide, and metaboric acid) in the overall exoergic reactions. These abstraction barriers are well below the barriers of abstractions for ground-state atomic oxygen and molecular oxygen. In this sense, gas-phase BO, AlO, and BO2 catalyze the oxidation of gas-phase JP-10 via hydrogen abstraction, forming highly reactive JP-10 radicals. Overall, the addition of RMNPs to JP-10 not only provides a higher energy density fuel but is also expected to lead to shorter ignition delays compared to pure JP-10 due to the highly reactive pool of radicals (BO, AlO, and BO2) formed in the initial stage of the oxidation process.

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