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1.
Oxid Med Cell Longev ; 2021: 6699821, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33542784

RESUMO

Saffron is commonly used in traditional medicines and precious perfumes. It contains pharmacologically active compounds with notably potent antioxidant activity. Saffron has a variety of active components, including crocin, crocetin, and safranal. Oxidative stress plays an important role in many cardiovascular diseases, and its uncontrolled chain reaction is related to myocardial injury. Numerous studies have confirmed that saffron exact exhibits protective effects on the myocardium and might be beneficial in the treatment of cardiovascular disease. In view of the role of oxidative stress in cardiovascular disease, people have shown considerable interest in the potential role of saffron extract as a treatment for a range of cardiovascular diseases. This review analyzed the use of saffron in the treatment of cardiovascular diseases through antioxidant stress from four aspects: antiatherosclerosis, antimyocardial ischemia, anti-ischemia reperfusion injury, and improvement in drug-induced cardiotoxicity, particularly anthracycline-induced. Although data is limited in humans with only two clinically relevant studies, the results of preclinical studies regarding the antioxidant stress effects of saffron are promising and warrant further research in clinical trials. This review summarized the protective effect of saffron in cardiovascular diseases and drug-induced cardiotoxicity. It will facilitate pharmacological research and development and promote utilization of saffron.

2.
PLoS One ; 16(2): e0246279, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33529214

RESUMO

Tail adipose as one of the important functional tissues can enhance hazardous environments tolerance for sheep. The objective of this study was to gain insight into the underlying development mechanisms of this trait. A quantitative analysis of protein abundance in ovine tail/rump adipose tissue was performed between Chinese local fat- (Kazakh, Hu and Lanzhou) and thin-tailed (Alpine Merino, Tibetan) sheep in the present study by using lable-free approach. Results showed that 3400 proteins were identified in the five breeds, and 804 were differentially expressed proteins, including 638 up regulated proteins and 83 down regulated proteins in the tail adipose tissues between fat- and thin-tailed sheep, and 8 clusters were distinguished for all the DEPs' expression patterns. The differentially expressed proteins are mainly associated with metabolism pathways and peroxisome proliferator activated receptor signaling pathway. Furthermore, the proteomics results were validated by quantitative real-time PCR and Western Blot. Our research has also suggested that the up-regulated proteins ACSL1, HSD17ß4, FABP4 in the tail adipose tissue might contribute to tail fat deposition by facilitating the proliferation of adipocytes and fat accumulation in tail/rump of sheep. Particularly, FABP4 highly expressed in the fat-tail will play an important role for tail fat deposition. Our study might provide a novel view to understanding fat accumulation in special parts of the body in sheep and other animals.

3.
Mol Cell ; 2021 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-33571424

RESUMO

Mediator is a universal adaptor for transcription control. It serves as an interface between gene-specific activator or repressor proteins and the general RNA polymerase II (pol II) transcription machinery. Previous structural studies revealed a relatively small part of Mediator and none of the gene activator-binding regions. We have determined the cryo-EM structure of the Mediator at near-atomic resolution. The structure reveals almost all amino acid residues in ordered regions, including the major targets of activator proteins, the Tail module, and the Med1 subunit of the Middle module. Comparison of Mediator structures with and without pol II reveals conformational changes that propagate across the entire Mediator, from Head to Tail, coupling activator- and pol II-interacting regions.

4.
J Agric Food Chem ; 2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33594885

RESUMO

Glycerol-plasticized high-amylose corn starch/konjac glucomannan (HCS/KGM) composite films incorporated with various concentrations of ß-cyclodextrin (ß-CD) were prepared and investigated for structural, mechanical, and physical properties. The results of X-ray diffraction, attenuated total reflectance Fourier transform infrared spectroscopy, thermogravimetric analyses, and scanning electron microscopy indicated that ß-CD excluded from the polymer chains and aggregated to form crystals during film formation, which drove HCS to interact with KGM more compactly. The thickness and transparency of the films increased after ß-CD was incorporated. More associations of HCS/KGM enhanced the mechanical properties and reduced the moisture content of the films. The water vapor permeability of the HCS/KGM composite film was also improved significantly with the incorporation of ß-CD. The enhanced association between biopolymers in the presence of ß-CD will advance the development of a degradable active composite packaging film.

5.
Talanta ; 225: 122064, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33592783

RESUMO

Quantum dots (QDs) based fluorescent nanobeads are considered as promising materials for next generation point-of-care diagnosis systems. In this study, we carried out, for the first time, the synthesis of QDs nanobeads using polystyrene (PS) nanobead as the template. QDs loading on PS nanobead surface in this method can be readily achieved by the use of polyelectrolyte, avoiding the time-consuming and uncontrollable silane reagents-involved functionalization procedure that conventional synthesis of silica-based QDs nanobeads often suffer from. Notably, the application of QDs nanobeads in suspension microarray for H5N1 virus detection leads to a sensitivity lower than 25 PFU/mL. In addition, QDs nanobead was also incorporated into lateral flow assay for SARS-CoV-2 antibody detection, leading to more than one order of magnitude detection sensitivity as compared to that of commercial one based on colloid gold.

6.
BMC Genomics ; 22(1): 127, 2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33602144

RESUMO

BACKGROUND: The quality and yield of wool determine the economic value of the fine-wool sheep. Therefore, discovering markers or genes relevant to wool traits is the cornerstone for the breeding of fine-wool sheep. In this study, we used the Illumina HiSeq X Ten platform to re-sequence 460 sheep belonging to four different fine-wool sheep breeds, namely, Alpine Merino sheep (AMS), Chinese Merino sheep (CMS), Aohan fine-wool sheep (AHS) and Qinghai fine-wool sheep (QHS). Eight wool traits, including fiber diameter (FD), fiber diameter coefficient of variance (FDCV), fiber diameter standard deviation (FDSD), staple length (SL), greasy fleece weight (GFW), clean wool rate (CWR), staple strength (SS) and staple elongation (SE) were examined. A genome-wide association study (GWAS) was performed to detect the candidate genes for the eight wool traits. RESULTS: A total of 8.222 Tb of raw data was generated, with an average of approximately 8.59X sequencing depth. After quality control, 12,561,225 SNPs were available for analysis. And a total of 57 genome-wide significant SNPs and 30 candidate genes were detected for the desired wool traits. Among them, 7 SNPs and 6 genes are related to wool fineness indicators (FD, FDCV and FDSD), 10 SNPs and 7 genes are related to staple length, 13 SNPs and 7 genes are related to wool production indicators (GFW and CWR), 27 SNPs and 10 genes associated with staple elongation. Among these candidate genes, UBE2E3 and RHPN2 associated with fiber diameter, were found to play an important role in keratinocyte differentiation and cell proliferation. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment results, revealed that multitude significant pathways are related to keratin and cell proliferation and differentiation, such as positive regulation of canonical Wnt signaling pathway (GO:0090263). CONCLUSION: This is the first GWAS on the wool traits by using re-sequencing data in Chinese fine-wool sheep. The newly detected significant SNPs in this study can be used in genome-selective breeding for the fine-wool sheep. And the new candidate genes would provide a good theoretical basis for the fine-wool sheep breeding.

7.
Biomark Med ; 15(1): 43-55, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33427499

RESUMO

Background: Triple-negative breast cancer (TNBC) is characterized by fast tumor increase, rapid recurrence and natural metastasis. We aimed to identify a genetic signature for predicting the prognosis of TNBC. Materials & methods: We conducted a weighted correlation network analysis of datasets from the Gene Expression Omnibus. Multivariate Cox regression was used to construct a risk score model. Results: The multi-factor risk scoring model was meaningfully associated with the prognosis of patients with TBNC. The predictive power of the model was demonstrated by the time-dependent receiver operating characteristic curve and Kaplan-Meier curve, and verified using a validation set. Conclusion: We established a long noncoding RNA-based model for the prognostic prediction of TNBC.

8.
Biochem Biophys Res Commun ; 540: 75-82, 2021 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-33450483

RESUMO

The ongoing pandemic of COVID-19 alongside the outbreaks of SARS in 2003 and MERS in 2012 underscore the significance to understand betacoronaviruses as a global health challenge. SARS-CoV-2, the etiological agent for COVID-19, has infected over 50 million individuals' worldwide with more than ∼1 million fatalities. Autophagy modulators have emerged as potential therapeutic candidates against SARS-CoV-2 but recent clinical setbacks urge for better understanding of viral subversion of autophagy. Using MHV-A59 as a model betacoronavirus, time-course infections revealed significant loss in the protein level of ULK1, a canonical autophagy-regulating kinase, and the concomitant appearance of a possible cleavage fragment. To investigate whether virus-encoded proteases target ULK1, we conducted in-vitro and cellular cleavage assays and identified ULK1 as a novel bona fide substrate of SARS-CoV-2 papain-like protease (PLpro). Mutagenesis studies discovered that ULK1 is cleaved at a conserved PLpro recognition sequence (LGGG) after G499, separating its N-terminal kinase domain from a C-terminal substrate recognition region. Over-expression of SARS-CoV-2 PLpro is sufficient to impair starvation-induced autophagy and disrupt formation of ULK1-ATG13 complex. Finally, we demonstrated a dual role for ULK1 in MHV-A59 replication, serving a pro-viral functions during early replication that is inactivated at late stages of infection. In conclusion, our study identified a new mechanism by which PLpro of betacoronaviruses induces viral pathogenesis by targeting cellular autophagy.


Assuntos
Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Autofagia , /enzimologia , Animais , Autofagia/genética , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Células Cultivadas , Camundongos
9.
BMC Genomics ; 22(1): 78, 2021 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-33485316

RESUMO

BACKGROUND: Copy number variation (CNV) is an important source of genetic variation that has a significant influence on phenotypic diversity, economically important traits and the evolution of livestock species. In this study, the genome-wide CNV distribution characteristics of 32 fine-wool sheep from three breeds were analyzed using resequencing. RESULTS: A total of 1,747,604 CNVs were detected in this study, and 7228 CNV regions (CNVR) were obtained after merging overlapping CNVs; these regions accounted for 2.17% of the sheep reference genome. The average length of the CNVRs was 4307.17 bp. "Deletion" events took place more frequently than "duplication" or "both" events. The CNVRs obtained overlapped with previously reported sheep CNVRs to variable extents (4.39-55.46%). Functional enrichment analysis showed that the CNVR-harboring genes were mainly involved in sensory perception systems, nutrient metabolism processes, and growth and development processes. Furthermore, 1855 of the CNVRs were associated with 166 quantitative trait loci (QTL), including milk QTLs, carcass QTLs, and health-related QTLs, among others. In addition, the 32 fine-wool sheep were divided into horned and polled groups to analyze for the selective sweep of CNVRs, and it was found that the relaxin family peptide receptor 2 (RXFP2) gene was strongly influenced by selection. CONCLUSIONS: In summary, we constructed a genomic CNV map for Chinese indigenous fine-wool sheep using resequencing, thereby providing a valuable genetic variation resource for sheep genome research, which will contribute to the study of complex traits in sheep.

10.
Sheng Wu Gong Cheng Xue Bao ; 37(1): 253-265, 2021 Jan 25.
Artigo em Chinês | MEDLINE | ID: mdl-33501806

RESUMO

Based on observing the cytological characteristics of the flower buds of the functional male sterile line (S13) and the fertile line (F142) in eggplant, it was found that the disintegration period of the annular cell clusters in S13 anther was 2 days later than that of F142, and the cells of stomiun tissue and tapetum in F142 disintegrated on the blooming day, while it did not happen in S13. The comparative transcriptomic analysis showed that there were 1 436 differential expression genes (DEGs) (651 up-regulated and 785 down-regulated) in anthers of F142 and S13 at 8, 5 days before flowering and flowering day. The significance analysis of GO enrichment indicated that there were more unigene clusters involved in single cell biological process, metabolism process and cell process, and more catalytic activity and binding function were involved in molecular functions. Through KEGG annotation we found that the common DEGs were mainly enriched in the biosynthesis of secondary metabolites, metabolic pathway, protein processing in endoplasmic reticulum, biosynthesis of amino acids, carbon metabolism and plant hormone signal transduction. The fifteen genes co-expression modules were identified from 16 465 selected genes by weighted gene co-expression network analysis (WGCNA), three of which (Plum2, Royalblue and Bisque4 modules) were highly related to S13 during flower development. KEGG enrichment showed that the specific modules could be enriched in phenylpropanoid biosynthesis, photosynthesis, porphyrin and chlorophyll metabolism, α-linolenic acid metabolism, polysaccharide biosynthesis and metabolism, fatty acid degradation and the mutual transformation of pentose and glucuronic acid. These genes might play important roles during flower development of S13. It provided a reference for further study on the mechanism of anther dehiscence in eggplant.


Assuntos
Infertilidade Masculina , Solanum melongena , Flores/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Humanos , Masculino , Redes e Vias Metabólicas/genética , Solanum melongena/genética , Transcriptoma/genética
11.
Lasers Surg Med ; 2021 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-33508159

RESUMO

BACKGROUND AND OBJECTIVE: To compare changes in skin sensitivity before and after treatment with a 1064-nm Q-switched Nd:YAG laser in healthy individuals, and to provide a reference for clinicians to use this laser reasonably. STUDY DESIGN/MATERIALS AND METHODS: Nineteen healthy female volunteers underwent 10 random unilateral 1064-nm Q-switched Nd:YAG laser treatments. The skin transepidermal water loss rate (TEWL), skin glossiness, epidermal and dermal thickness and density, current perception threshold (CPT) value, facial blood perfusion were determined before and after treatment at different time points. Moreover, the changes in skin barrier function, blood vessels, and sensory nerve reaction in the treated and untreated sides of the face were recorded before and after treatment. RESULTS: Seventeen volunteers completed the 12-month follow-up study after 1064-nm Q-switched Nd:YAG laser treatment. At D3, M3, and M6, skin TEWL was decreased on the treated side of the face. Skin glossiness was significantly improved in the early post-treatment period (D1-D7) and M3, M6, and M12 compared with the untreated side of the face. There was no significant change in dermal and epidermal thickness or density at all time points before and after treatment. There were no significant differences in sensory nerve CPT values and local blood flow volume or velocity between the treated side of the face and the untreated side before and after treatment. CONCLUSION: Multiple low-energy 1064-nm Q-switched Nd:YAG laser treatments will not affect the barrier function of facial skin, skin nerve sensitivity, or local microcirculation of healthy skin over the long term. Therefore, 1064-nm Q-switched Nd:YAG laser treatment is safe, and does not alter skin sensitivity. Lasers Surg. Med. © 2021 Wiley Periodicals LLC.

12.
Biomol NMR Assign ; 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33398629

RESUMO

Vaccinia virus (VACV) belonging to the poxvirus family enters the host cell via two different entry pathways; either endocytosis or virus/host cell membrane fusion. With respect to the virus/host cell membrane fusion, there are eleven viral membrane proteins forming a complicated entry-fusion complex (EFC), including A28, A21, A16, F9, G9, G3, H2, J5, L5, L1 and O3, to conduct the fusion function. These EFC components are highly conserved in all poxviruses and each of them is essential and necessary for the fusion activity. So far, with the exceptions of L1 and F9 whose crystal structures were reported, the structural information about other EFC components remains largely unclear. We aim to conduct a structural and functional investigation of VACV virus-entry membrane protein A28. In this work, we expressed and purified a truncated form of A28 (14 kDa; residues 38-146, abbreviated as tA28 hereinafter), with deletion of its transmembrane domain (residues 1-22) and a hydrophobic segment (residues 23-37). And the assignments of its backbone and side chain 1H, 13C and 15N chemical shifts of tA28 are reported. The secondary structure propensity from TALOS+ indicates that tA28 does contain three α-helices, six ß-strands and connecting loops. Aside from this, we demonstrated that tA28 does interact with fusion suppressor viral protein A26 (residues 351-500) by the 1H-15N HSQC spectrum. We interpret that A28 binding to A26 deactivates EFC fusion activity. The current study provides a valuable framework towards further structural analyses of this protein and for better understanding virus/host cell membrane fusion mechanism in association with virus entry.

13.
Crit Rev Food Sci Nutr ; : 1-11, 2021 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-33401939

RESUMO

With increasing awareness of environmental protection, petroleum-based raw materials are continuously decreasing, which in turn necessitated the development of eco-friendly sustainable biomaterials, as alternative strategy. Starch could be an ideal substitute. Corn starch has been used as a renewable material for development of biodegradable packaging, owing to great varieties, low cost, large-scale industrial production, and good films forming properties. Unfortunately, its poor mechanical and barrier properties have limited the application of starch-based films. Thence, plasticizers were added to overcome the aforementioned pitfalls and improve the films elongation, distribution, flexibility, elasticity, and rigidity. Addition of plasticizers can change the continuity and therefore would enhance the properties of corn starch-based films. While plasticization can improve the tensile strength and percent elongation, it can reduce the water resistance in prepared films. Herein, we focused on changes of starch granules during gelatinization process, types of biodegradable films, as well as the types of modified starch with plasticizers. Furthermore, the influence of plasticizers on corn starch-based films and the physicochemical properties of various types of corn starch-based films were also addressed.

14.
Int J Biol Macromol ; 170: 593-601, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33385448

RESUMO

A novel antimicrobial gel composed of κ-carrageenan (KC) and a cinnamon essential oil (CEO)/hydroxypropyl-ß-cyclodextrin (HPCD) composite was developed. The CEO/HPCD composite was characterized by UV-visible spectrophotometry and Fourier-transform infrared spectroscopy (FT-IR), and the changes in the principal components of CEO upon encapsulation by HPCD were analyzed by gas chromatography-mass spectrometry (GC-MS). The physicochemical properties, release kinetics and antimicrobial activity of the fabricated gels were investigated. The hardness of the KC gels increased with composite concentration in the range of 1.0-3.0% (w/v) and thereafter decreased. A similar trend was observed for the gumminess and chewiness, whereas the gel springiness remained essentially constant. The CEO/HPCD composite also enhanced the fluidity of the system, and the syneresis was positively correlated with the composite concentration. The controlled release of CEO from the gels was affected by the relative humidity (RH) and CEO content. The Ritger-Peppas model indicated that the CEO release kinetics from the gels proceeded through a combination of diffusion and framework erosion. The KC gel containing 5% CEO/HPCD composite displayed effective antimicrobial activity, prolonging the shelf life of sliced bread by at least two days. The reported gels may have potential applications as a promising material for food preservation.

15.
Int J Biol Macromol ; 173: 219-224, 2021 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-33482214

RESUMO

Sweet-waxy is a new type of maize with waxy and sugary double recessive genes. This study aims to clarify starch structural and functional properties of this maize type. Grains with sweet-waxy and waxy phenotypes were separated from an ear using the two sweet-waxy maize hybrids of ATN and NKY as materials. Compared with waxy maize starch, the sweet-waxy maize starch mainly comprises small-sized round granules despite the typical waxy character of both starches. Mw, Mn, and relative crystallinity of sweet-waxy starch were higher than those of waxy starch in both hybrids. The average chain length of waxy starch was higher in ATN but lower in NKY compared with that of sweet-waxy starch. However, polydispersity (Mw/Mn) and F1 fraction were high in sweet-waxy and waxy starches in ATN and NKY, respectively. Breakdown viscosity, gelatinization enthalpy and temperatures of both hybrids were low in sweet-waxy starch. Peak viscosity was higher in waxy starch in NKY and similar between sweet-waxy and waxy starches in ATN. Retrogradation percentage was high and low for sweet-waxy starches in ATN and NKY, respectively.

16.
Carbohydr Polym ; 254: 117314, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33357877

RESUMO

Herein, corn starch-based films were prepared by casting method and different concentrations of Zanthoxylum bungeanum essential oil (ZYO) were added to evaluate the morphological, optical, mechanical, and barrier properties of the resultant films. Additionally, structural analysis was carried out via atomic force microscopy and the antibacterial activities against Staphylococcus aureus, Escherichia coli, and Listeria monocytogenes were assessed. We found that the elongation at break was significantly increased (P < 0.05), whereas tensile strength, moisture content, solubility in water, and water vapor permeability rate were significantly decreased (P < 0.05) in films incorporated with ZYO compared with oil-free films. Furthermore, incorporation of ZYO increased the opacity and decreased the gloss of films. Incorporation of ZYO appears to increase the surface roughness and the antibacterial activity of the films. In sum, ZYO can potentially be used in food packaging, particularly food intended to be protected from light and susceptible to spoilage by microorganisms.

17.
Cancer Lett ; 497: 28-40, 2021 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-33069768

RESUMO

Angiogenesis factors are widely known to promote tumor growth by increasing tumor angiogenesis in the tumor microenvironment, however, little is known whether their intracellular function is involved in tumorigenesis. Here we show that AGGF1 acts as a tumor suppressor by regulating p53 when acting inside tumor cells. AGGF1 antagonizes MDM2 function to inhibit p53 ubiquitination, increases the acetylation, phosphorylation, stability and expression levels of p53, activates transcription of p53 target genes, and regulates cell proliferation, cell cycle, and apoptosis. AGGF1 also interacts with p53 through the FHA domain. Somatic AGGF1 variants in the FHA domain in human tumors, including p.Q467H, p.Y469 N, and p.N483T, inhibit AGGF1 activity on tumor suppression. These results identify a key role for AGGF1 in an AGGF1-MDM2-p53 signaling axis with important functions in tumor suppression, and uncover a novel trans-tumor-suppression mechanism dependent on p53. This study has potential implications in diagnosis and therapies of cancer.

18.
Carbohydr Polym ; 251: 117039, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33142597

RESUMO

Recently, starch-based packaging materials have become one of research hot points. In the present study, glycerol-plasticized composite films based on high amylose corn starch (HCS) and konjac glucomannan (KGM) were developed. The influence of KGM on the film-forming properties of HCS and the physicochemical properties of the resulting films were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric (TG) analysis and water vapor permeability (WVP). The crystallinity and the proportion of short-range order structure of the films increased first and then declined with the addition of KGM. The micromorphology of the films exhibited the more even texture after KGM was incorporated in. The tensile strength, elongation at break and water resistance of HCS film were also improved significantly. The synergistic effect between HCS and KGM improved the film-forming ability of HCS. The optimal addition amount of KGM was 0.3 %.

19.
Entropy (Basel) ; 22(1)2020 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-33285839

RESUMO

The cross-slot geometry plays an important role in the study of nonlinear effects of viscoelastic fluids. The flow of viscoelastic fluid in a micro cross-slot with a high channel aspect ratio (AR, the ratio of channel depth to width) can be divided into three types, which are symmetric flow, steady-state asymmetric flow and time-dependent flow under the inlet condition with a constant velocity. However, the flow pattern of a viscoelastic fluid in the cross-slot when a stimulation is applied at inlets has been rarely reported. In this paper, the response of cross-slot flow under an external sinusoidal stimulation is studied by numerical simulations of a two-dimensional model representing the geometry with a maximum limit of AR. For the cases under constant inlet velocity conditions, three different flow patterns occur successively with the increase of Weissenberg number (Wi). For the cases under sinusoidal varying inlet velocity conditions, when the stimulation frequency is far away from the natural frequency of a viscoelastic fluid, the frequency spectrum of velocity fluctuation field shows the characteristics of a fundamental frequency and several harmonics. However, the harmonic frequency disappears when the stimulation frequency is close to the natural frequency of the viscoelastic fluid. Besides, the flow pattern shows spatial symmetry and changes with time. In conclusion, the external stimulation has an effect on the flow pattern of viscoelastic fluid in the 2D micro cross-slot channel, and a resonance occurs when the stimulation frequency is close to the natural frequency of the fluid.

20.
Food Res Int ; 138(Pt B): 109778, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33288164

RESUMO

High-fat diets (HFDs) can induce health problems including gut microbiota dysbiosis and cardiac dysfunction. In this study, we modulated the gut microbiota in mice to investigate whether Lycium barbarum polysaccharide (LBP), a potential prebiotic fiber, could alleviate HFD-induced myocardial injury. Mice fed a HFD were given LBP (HFPD group) by gavage once/day for 2 months. Left ventricular function and serum trimethylamine N-oxide were significantly improved in HFPD mice compared with HFD mice. HFD increased the abundances of Bifidobacterium, Lactobacillus, and Romboutsia, while LBP increased the abundances of Gordonibacter, Parabacteroides, and Anaerostipes. Fecal metabolic profiling revealed significant increases in metabolites involved in nicotinate, nicotinamide and purine metabolism pathways, as well as indole derivatives of tryptophan metabolites in the HFPD group. LBP reduced intestinal permeability and inflammatory cytokine levels, maintained a healthy intestinal microenvironment, and alleviated myocardial injury. Modulating the gut microbiota is a potential treatment for cardiovascular diseases.

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