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1.
J Musculoskelet Neuronal Interact ; 21(4): 560-567, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34854396

RESUMO

OBJECTIVES: To explore the role and mechanism of miR-125a-3p in rheumatoid arthritis (RA) progression. METHODS: The RA-tissues and fibroblast-like synovial cells in rheumatoid arthritis (RA-FLS) were used in this study. qRT-PCR, western blot and ELISA assay were performed to detect the expression levels of IL-6, IL-ß and ΤΝF-α. Dual-luciferase reporter gene assay was used to observe the binding effect of miR-125a-3p and MAST3, and CCK-8 was used to observe the effect of miR-125a-3p on the proliferation of RA-FLS. RESULTS: miR-125a-3p was significantly downregulated in the RA-tissues and RA-FLS, and miR-125a-3p could inhibit the proliferation and reduce the inflammation response of RA-FLS. Besides, MAST3 was found as a target of miR-125a-3p, and increased MAST3 could reverse the effects of miR-125a-3p on RA-FLS including decreased proliferation, reduced inflammation level and the inactivation of Wnt/ß-catenin and NF-κB pathways. CONCLUSIONS: This study suggests that miR-125a-3p could inactivate the Wnt/ß-catenin and NF-κB pathways to reduce the proliferation and inflammation response of RA-FLS via targeting MAST3.

2.
Phytomedicine ; : 153860, 2021 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-34836743

RESUMO

BACKGROUND: The inflammatory state of diabetes promotes high platelet response and endothelial adhesion, which are the main risk factors for cardiovascular events. Tetramethylpyrazine (TMP) is an amide alkaloid isolated from the traditional Chinese medicine Rhizoma Ligustici Chuanxiong, which has been widely used in the clinical treatment of ischemic cardiovascular disease. PURPOSE: This study aimed to investigate whether TMP could alleviate diabetes-induced high platelet response and endothelial adhesion and the underlying mechanisms. METHODS: Type 2 diabetes mellitus (T2DM) rat model was established by high-fat feeding combined with low dose of streptozotocin. Rats in the TMP treatment group were administered with TMP (100 or 200 mg/kg) for 21 days. Cultured human umbilical vein endothelial cells (HUVECs) were stimulated with glucose (5.5 mM) to induce endothelial activation. The NOD-like receptor protein 3 (NLRP3) over- and low-expressing cell models were established via transfection of NLRP3 lentivirus plasmid into HUVECs. INF39 (25 mg/kg), a chemical inhibitor of NLRP3 inflammasome, was used to explore the role of NLRP3 in T2DM associated high platelet response and endothelial adhesion. RESULTS: TMP effectively improved the prothrombotic phenotypes and inhibited the expression of vascular inflammatory factors and adhesion molecules in T2DM rats. TMP inhibited NLRP3 inflammasome and reduced the adhesion of HUVECs to platelets and monocytes in vitro. Over-expression of NLRP3 blocked the effect of TMP on HUVECs activation and adhesion, while TMP had no effect on NLRP3 low-expressing HUVECs. The NLRP3 inhibitor INF39 produced similar effects of TMP on diabetes-induced high platelet response, endothelial adhesion and vascular inflammation. CONCLUSION: TMP ameliorates diabetes-induced high platelet response and endothelial adhesion via inhibiting NLRP3 inflammasome activation in T2DM rats, which provide a new basis for the clinical prevention and treatment of diabetes-associated cardiovascular events.

3.
Nano Today ; 41: 101308, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34630625

RESUMO

A once-in-a-century global public health crisis, the COVID-19 pandemic has damaged human health and world economy greatly. To help combat the virus, we report a self-resetting molecular probe capable of repeatedly detecting SARS-CoV-2 RNA, developed by orchestrating a fuel dissipative system via DNA nanotechnology. A set of simulation toolkits was utilized to design the probe, permitting highly consistent signal amplitudes across cyclic detections. Uniquely, full width at half maximum regulated by dissipative kinetics exhibits a fingerprint signal suitable for high confidential identifications of single-nucleotide variants. Further examination on multiple human-infectious RNA viruses, including ZIKV, MERS-CoV, and SARS-CoV, demonstrates the generic detection capability and superior orthogonality of the probe. It also correctly classified all the clinical samples from 55 COVID-19 patients and 55 controls. Greatly enhancing the screening capability for COVID-19 and other infectious diseases, this probe could help with disease control and build a broader global public health agenda.

4.
Org Lett ; 23(19): 7381-7385, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34546064

RESUMO

DNA-encoded library (DEL) technology is a powerful tool in the discovery of bioactive probe molecules and drug leads. Mostly, the success in DEL technology stems from the molecular diversity of the chemical libraries. However, the construction of DELs has been restricted by the idiosyncratic needs and the required low concentration (∼1 mM or less) of the library intermediate. Here, we report visible-light-promoted on-DNA radical coupling reactions via an electron donor-acceptor (EDA) complex and a reversible adsorption to solid support (RASS) strategy. This protocol provides a unique solution to the challenges of increasing the reactivity of highly diluted DNA substrates and reducing the residues of heavy metals from photocatalysts. A series of on-DNA indole sulfone and selenide derivatives were obtained with good to quantitative conversions. It is anticipated that these mild-condition on-DNA radical reactions will significantly improve the chemical diversity of DELs and find widespread utility to DEL construction.

5.
Small ; 17(44): e2103623, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34546645

RESUMO

Carbon dots (CDs) are widely studied for years due to their unique luminescent properties and potential applications in many fields. However, aggregation-caused quenching, monotonous emission modes, and unsustainable preparation impose restrictions on their performance and practical applications. Here, this work reports the facile synthesis of sustainable silk-derived multimode emitting CDs with dispersed-state fluorescence (DSF), aggregation-induced fluorescence (AIF), and aggregation-induced room temperature phosphorescence (AIRTP) through radiating sericin proteins in a household microwave oven (800 W, 2.5 min). The structure, luminescent properties, and the mechanism are investigated and discussed. The sericin-derived CDs have graphitized cores and heteroatom-cluster-rich surfaces. The DSF corresponds to the graphitized cores and the AIF origins from the aggregation-induced abundant orbital energy levels on the heteroatom-cluster-rich surfaces. The presence of abundant hydrogen bonds and small gap between the lowest singlet and triplet excited states induces AIRTP. Finally, based on the unique multimode emission of the prepared CDs, their applications in high-performance white-light-emitting diode, information encryption, anti-counterfeiting, and visual humidity sensors are demonstrated.

6.
BMC Ophthalmol ; 21(1): 299, 2021 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-34391397

RESUMO

BACKGROUND: To evaluate the prevalence of myopia in school students in Urumqi, China, and explore the influence of the interaction between parental myopia and poor reading and writing habits on myopia to identify the at-risk population and provide evidence to help school students avoid developing myopia. METHODS: A cross-sectional survey was conducted with 6,883 school students aged 7-20 years in Urumqi in December 2019. The Standard Eye Chart and mydriatic optometry were used to determine whether students had myopia. Falconer's method was used to calculate the heritability of parental myopia. Multivariate unconditional logistic regression models were used to analyze the risk factors for myopia and the additive and multiplicative interaction of parental myopia and poor reading and writing habits. RESULTS: After standardizing the age of the 6,883 students, the overall prevalence rate of myopia was 47.50 %. The heritability of parental myopia was 66.57 % for boys, 67.82 % for girls, 65.02 % for the Han group, and 52.71 % for other ethnicities. There were additive interactions between parental myopia and poor reading and writing habits; among them, parental myopia and poor eye habits when reading and writing (the distance between the eyes and book is less than 30 cm when reading and writing, fingers block the sight of one eye while holding the pen, and leaning one's body when reading and writing; habit 1) increased the risk of myopia by 10.99 times (odds ratio [OR] = 10.99, 95 % confidence interval [CI] = 8.33-14.68), parental myopia and poor reading posture (reading while lying down, walking, or in the car; habit 2) increased the risk of myopia by 5.92 times (OR = 5.92, 95 % CI = 4.84-7.27). There was no multiplicative interaction between parental myopia and habit 1 or habit 2 (OR = 0.69, 95 % CI = 0.44-1.08; OR = 0.89, 95 % CI = 0.66-1.21, respectively). CONCLUSION: The prevalence of myopia among students in Urumqi, Xinjiang is relatively high. The risk of developing myopia is affected by parental myopia and poor reading and writing habits. In addition, parental myopia amplifies the harm caused by poor reading and writing habits, thereby increasing the risk of myopia. Students with parents who have myopia should be targeted during myopia prevention efforts.


Assuntos
Miopia , Leitura , China/epidemiologia , Estudos Transversais , Feminino , Hábitos , Humanos , Masculino , Miopia/epidemiologia , Pais , Postura , Prevalência , Fatores de Risco , Instituições Acadêmicas , Estudantes , Inquéritos e Questionários , Redação
7.
Ann Palliat Med ; 10(7): 7960-7969, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34353082

RESUMO

BACKGROUND: Rheumatoid arthritis (RA) is a chronic joint disease. The study aimed to explore the effects of microRNA (miR)-449 and histone deacetylase 1 (HDAC1) on the proliferation, invasion, and apoptosis of synovial fibroblasts in rheumatoid arthritis. METHODS: Synovial tissue was collected from 20 patients with RA and 20 patients with osteoarthritis (OA) who underwent joint replacement surgery. RA synovial fibroblasts (RASFs) and OA synovial fibroblasts (OASFs) were isolated and cultured. Real-time quantitative PCR was used to detect the expression levels of miR-449 and HDAC1 in synovial tissues and cells. Western blot was performed to detect the cellular expression levels of HDAC1 protein, and apoptosis and invasion-related proteins. The proliferation, invasion, and apoptosis of RASFs were detected by MTT assay, Transwell assay, and flow cytometry. The dual-luciferase reporter gene was used to test the targeting relationship between inflammatory miR-449 and HDAC1. RESULTS: Compared with normal synovial tissue and OASFs, the levels of HDAC1 messenger RNA in RA synovial tissue and RASF cells were significantly increased (P<0.01), while the expression levels of miR-449 were significantly decreased (P<0.01). The dual-luciferase reporter gene experiment confirmed that miR-449 could specifically bind to the 3' untranslated region of HDAC1 to inhibit its luciferase activity (P<0.05). HDAC1 inhibition or miR-449 overexpression significantly inhibited the proliferation and invasion of RASFs (P<0.001), while inducing their apoptosis (P<0.001). HDAC1 overexpression reversed the biological effects of miR-449 on RASFs (P<0.001). CONCLUSIONS: miR-449 inhibits the proliferation and invasion of RASFs and induces their apoptosis by targeting HDAC1, thereby exerting a protective effect against RA.


Assuntos
Artrite Reumatoide , MicroRNAs , Apoptose/genética , Artrite Reumatoide/genética , Proliferação de Células/genética , Fibroblastos , Histona Desacetilase 1/genética , Humanos , MicroRNAs/genética
8.
Ann Clin Lab Sci ; 51(4): 487-493, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34452886

RESUMO

OBJECTIVE: Hepatitis B X-interacting protein (HBXIP) interacts with hepatitis B virus X protein to participate in the replication of the hepatitis B virus and carcinogenesis. Cellular growth and metastasis of non-small-cell lung cancer (NSCLC) are repressed by HBXIP inhibition. However, the role and mechanism of HBXIP on NSCLC cell growth remain unknown. MATERIALS: Expression of HBXIP was assessed by qRT-PCR and Western blot. siRNA targeting HBXIP was applied to detect cell viability and proliferation by MTT and colony formation assays. In vivo tumor growth was assessed, and anti-tumor immunity was determined by flow cytometry. The downstream partners involved in HBXIP-mediated tumorigenesis were detected by Western blot. RESULTS: Expression of HBXIP and neuropilin1-1 (NRP-1) was higher in NSCLC tissues and cells than in paracancerous tissues and human lung epithelial cells. siRNA-mediated knockdown of HBXIP decreased the cell viability of NSCLC and suppressed proliferation. Protein expression of Lin28B and NRP-1 was reduced by the knockdown of HBXIP, and over-expression of Lin28B attenuated the HBXIP silence-induced decrease of NRP-1. In vivo tumor growth was suppressed by HBXIP silencing, and the knockdown of HBXIP enhanced anti-tumor immunity through the increase of CD4+ and CD8+ T lymphocytes. CONCLUSION: Down-regulation of HBXIP reduced Lin28B-mediated NRP-1 to suppress NSCLC cell growth and enhance anti-tumor immunity.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Biomarcadores Tumorais/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/patologia , Neuropilina-1/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Apoptose , Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Proliferação de Células , Feminino , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Neuropilina-1/genética , Prognóstico , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
9.
Virulence ; 12(1): 2162-2170, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34402737

RESUMO

The quinolone resistance crpP genes can mediate decreased susceptibility to quinolones. However, diversification and prevalence of crpP genes and crpP-carrying integrative and conjugative elements (ICEs) still need to be elucidated. In this study, genome sequencing was conducted for 200 Chinese Pseudomonas aeruginosa isolates, 16 of which were fully sequenced. All the 37 available CrpP variants were collected for phylogenetic analysis, 10 CrpP enzymes were chosen to conduct cloning and antimicrobial susceptibility test, and 22 crpP-carrying Tn6786-related ICEs were selected for detail genetic dissection analysis. Then, typing/nomenclature schemes for crpP variants and crpP-carrying ICEs were established for the first time. The 10 representative CrpP enzymes were confirmed to mediate decreased susceptibility to one to three quinolones. Tn6786-related ICEs displayed high-level diversification in both nucleotide sequences and modular structures. Mainly, massive gene acquisition/loss occurred across the whole genomes of Tn6786-related ICEs. 53.5% (107/200) of the tested clinical P. aeruginosa isolates from China carried crpP genes, which were exclusively located within chromosome-borne Tn6786-related ICEs. The crpP-carrying ICEs were at active stages of evolution and had the high potential to be an important vector for the dissemination of resistance genes besides crpP. The present study furthered the understanding of the bioinformatics and epidemiology of crpP genes and crpP-carrying ICEs.

10.
BMC Pediatr ; 21(1): 347, 2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34399722

RESUMO

BACKGROUND: Eczema is a chronic inflammatory disease associated with impaired quality of life. We identified indoor environmental risk factors, to provide strong evidence for the prevention and control of eczema in preschool children. METHODS: Using a cross-sectional study with stratified random cluster sampling, we conducted a self-administered questionnaire survey among 8153 parents of children aged 2-8 years in 60 kindergartens in six districts of Urumqi city during August 2019. RESULTS: Among 8153 preschool children, 12.0% of the children have been diagnosed with eczema. Multivariate logistic regression analysis showed that caesarean section (odds ratio [OR] = 1.18, 95% confidence interval [CI]: 1.03-1.36), being an only child (OR = 1.36, 95% CI: 1.18-1.57), presence of mould or moisture in the mother's home before pregnancy (OR = 1.53, 95% CI: 1.17-2.00), presence of flies or mosquitoes in the dwelling currently (OR = 1.31, 95% CI: 1.10-1.55), pets kept in the child's home currently (OR = 1.23, 95% CI: 1.01-1.51), presence of pets during child's first year (OR = 1.45, 95% CI: 1.14-1.85), and family history of eczema (OR = 3.53, 95% CI: 2.98-4.19) are the risk factors for the development of eczema, whereas ethnicity other than the Han Chinese (OR = 0.77, 95% CI: 0.61-0.96) is a protective factor for eczema. CONCLUSION: Preschool children in Urumqi are at a high risk of eczema, particularly those of the Han Chinese ethnicity. Parents should be attentive to the indoor living environment of children and take actions to reduce indoor humidity, pest control and elimination, and avoid raising pets to reduce the risk of development of eczema in children.


Assuntos
Cesárea , Eczema , Animais , Pré-Escolar , Estudos Transversais , Eczema/epidemiologia , Eczema/etiologia , Feminino , Humanos , Gravidez , Prevalência , Qualidade de Vida , Fatores de Risco
11.
Int Immunopharmacol ; 100: 108070, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34454292

RESUMO

RESEARCH QUESTION: In previous studies, we demonstrated that the human decidua and decidual stromal cells express high levels of CCL2 (chemokine (C-C motif) ligand 2, also known as monocyte chemotactic protein-1) and its receptor CCR2 (chemokine receptor 2). DSC-derived CCL2 interacts with CCR2 on DICs, causing the production and secretion of Th2-type cytokines, which promotes a Th2 bias at the maternal-foetal interface. Many pathogens may be present in the genital tract during pregnancy, but whether they affect immune regulation, especially Th2 regulation remains unknown. Toll-like receptors (TLRs) are a family of pattern-recognition receptors that recognise specific components of microbes and certain host molecules and play an important role in the host innate immune response. We examined TLR expression and evaluated whether TLRs could affect CCL2 secretion and subsequently induce Th1/Th2 responses. DESIGN: We used quantitative real-time PCR to measure TLR expression in the decidua and DSCs (decidual stromal cells). DSCs were cultured in the presence or absence of the TLR2 agonists PAM3CSK4, PGN-Sa, and zymosan, the TLR3 agonist poly (I:C) and the TLR4 agonist LPS. Then, the supernatants were assayed for CCL2 secreted by DSCs and IL-4, IFN-γ, IL-10, and TNF-α produced by DICs. RESULTS: Costimulation with TLR2, TLR3 and TLR4 agonists resulted in enhancing CCL2 production compared with that in the controls. Additionally, these TLR2, 3, and 4 agonists stimulated CD80/CD86 on DSCs and regulated IL-4 and IL-10 secretion on DICs. TLR2 and TLR3 agonists may promote Th1/Th2 immune bias. CONCLUSIONS: TLRs may induce Th1/Th2 responses by affecting the secretion of CCL2 at the maternal-foetal interface.

12.
Eur J Pharmacol ; 908: 174363, 2021 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-34297966

RESUMO

Aging-related diseases, especially vascular and neurological disorders cause huge economic burden. How to delay vascular and neurological aging is one of the insurmountable questions. G protein-coupled estrogen receptor 1 (GPER) has been extensively investigated in recent years due to its multiple biological responses. In this review, the function of GPER in aging-related diseases represented by vascular diseases, and neurological disorders were discussed. Apart from that, activation of GPER was also found to renovate the aging brain characterized by memory decline, but in a manner different from another two nuclear estrogen receptors estrogen receptor (ER)α and ERß. This salutary effect would be better clarified from the aspects of synaptic inputs and transmission. Furthermore, we carefully described molecular mechanisms underpinning GPER-mediated effects. This review would update our understanding of GPER in the aging process. Targeting GPER may represent a promising strategy in the aging-related disorders.

13.
Clin Oral Implants Res ; 32(9): 1105-1114, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34219293

RESUMO

OBJECTIVE: To compare the outcome after extensive lateral guided bone regeneration using deproteinized bovine bone mineral (DBBM) with or without autogenous bone chips in a canine model of chronic horizontal alveolar ridge defect. MATERIALS AND METHODS: The second, third and fourth lower premolars of both sides were extracted, and the buccal bone walls were completely removed in five beagle dogs. After 4 weeks, DBBM particles mixed with autogenous bone chips at a ratio of 1:1 were grafted at one side (DBBM/Auto group), while DBBM particles alone were grafted at the contralateral side (DBBM group). The graft materials on both sides were covered by a resorbable collagen membrane and fixation pins. Microcomputed tomographic volume and histomorphometric analyses were performed at 16 weeks post-surgery. RESULTS: The ridges of both groups were recovered horizontally, but new bone formation beyond the original ridge contour at the defect site was not found. The DBBM group exhibited a larger total radiographic augmented volume and new bone volume compared with the DBBM/Auto group, but the differences were minimal (p > .05). Histologically, the regenerated area and new bone area were also slightly larger without any statistical significance in the DBBM group than in the DBBM/Auto group (p > .05). CONCLUSION: The addition of autogenous bone chips to DBBM for lateral ridge augmentation may confer no advantage over grafting DBBM alone with respect to both space maintenance and de novo bone formation in dogs.


Assuntos
Aumento do Rebordo Alveolar , Substitutos Ósseos , Processo Alveolar , Animais , Regeneração Óssea , Transplante Ósseo , Bovinos , Cães , Minerais
14.
Front Cell Infect Microbiol ; 11: 690799, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34211858

RESUMO

In this study, a detailed genetic dissection of the huge and complex bla NDM-carrying genetic elements and their related mobile genetic elements was performed in Enterobacteriaceae. An extensive comparison was applied to 12 chromosomal genetic elements, including six sequenced in this study and the other six from GenBank. These 12 genetic elements were divided into five groups: a novel IME Tn6588; two related IMEs Tn6523 (SGI1) and Tn6589; four related ICEs Tn6512 (R391), Tn6575 (ICEPvuChnBC22), Tn6576, and Tn6577; Tn7 and its derivatives Tn6726 and 40.7-kb Tn7-related element; and two related IMEs Tn6591 (GIsul2) and Tn6590. At least 51 resistance genes, involved in resistance to 18 different categories of antibiotics and heavy metals, were found in these 12 genetic elements. Notably, Tn6576 carried another ICE Tn6582. In particular, the six bla NDM-carrying genetic elements Tn6588, Tn6589, Tn6575, Tn6576, Tn6726, and 40.7-kb Tn7-related element contained large accessory multidrug resistance (MDR) regions, each of which had a very complex mosaic structure that comprised intact or residual mobile genetic elements including insertion sequences, unit or composite transposons, integrons, and putative resistance units. Core bla NDM genetic environments manifested as four different Tn125 derivatives and, notably, two or more copies of relevant Tn125 derivatives were found in each of Tn6576, Tn6588, Tn6589, and 40.7-kb Tn7-related element. The huge and complex bla NDM-carrying genetic elements were assembled from complex transposition and homolog recombination. Firstly identified were eight novel mobile elements, including three ICEs Tn6576, Tn6577, and Tn6582, two IMEs, Tn6588 and Tn6589, two composite transposons Tn6580a and Tn6580b, and one integron In1718.


Assuntos
Infecções por Enterobacteriaceae , Enterobacteriaceae , Antibacterianos/farmacologia , Elementos de DNA Transponíveis , Enterobacteriaceae/genética , Humanos , Integrons/genética , Plasmídeos/genética , beta-Lactamases/genética
15.
Artigo em Inglês | MEDLINE | ID: mdl-34214662

RESUMO

Klebsiella pneumoniae (K. pneumoniae) is an important pathogen that can cause severe hospital- and community-acquired infections. To systematically investigate its methylation features, we determined the whole genome sequences of 14 K. pneumoniae strains covering varying serotypes, multilocus sequence typing (MLST), clonal groups (CGs), viscosity/virulence, and drug resistance. Their methylomes were further characterised using PacBio-SMRT and bisulfite technologies. We identified 15 methylation motifs (13 N6-methyladenine (6mA) and two 5-methylcytosine (5mC) motifs), among which eight were novel. Their corresponding DNA methylases (MTases) were also validated. Additionally, we analysed the genomic distribution of GATC and CCWGG methylation motifs shared by all strains, and identified differential distributive patterns of some hemi/un-methylated GATC motifs, which tend to be located within intergenic regions (IGRs). Specifically, we characterised the in vivo methylation kinetics at single base resolution on a genome-wide scale by simulating the dynamic processes of replication-mediated passive demethylation and MTase-catalysed re-methylation. The slower methylation rates of the GATC motifs in the replication origins (oriC) and IGRs implicate an epigenetic mechanism in the regulation of replication initiation and transcription. Our findings illustrate the first comprehensive dynamic methylome map of K. pneumoniae at single base resolution, and provide a useful reference to better understand epigenetic regulation in this and other bacterial species.

16.
J Phys Chem Lett ; 12(30): 7113-7119, 2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34296612

RESUMO

Combination of the merit of inorganic nanocrystals (NCs) and solution-processed conjugated polymer is a convenient strategy to obtain stable and efficient electroluminescent white-light-emitting diodes (el-WLEDs). In this work, an el-WLED was fabricated on the basis of Cd-free Cu-In-Zn-S (CIZS)/ZnS NCs blending with polyfluorene derivative poly[4-(octyloxy)-9,9-diphenylfluoren-2,7-diyl]-co-[5-(octyloxy)-9,9-diphenylfluoren-2,7-diyl] (PODPF), which exhibited a stable white light emission with a color rendering index value of 85. Meanwhile, it had a stable spectrum under high voltage due to the extremely weak energy transfer between PODPF and CIZS/ZnS NCs. To further improve the device performance, PC9O4 was used to replace PODPF, which presented better solubility and smoother film-forming properties. Thus, the maximum external quantum efficiency (EQE) of the optimized el-WLED was increased by 221% while maintaining a stable spectrum under high voltage. This work may provide a great foundation on color mixing cadmium-free el-WLEDs.

17.
An Acad Bras Cienc ; 93(suppl 1): e20201096, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34076206

RESUMO

BINGO (BAO from Integrated Neutral Gas Observations) is a unique radio telescope designed to map the intensity of neutral hydrogen distribution at cosmological distances, making the first detection of Baryon Acoustic Oscillations (BAO) in the frequency band 980 MHz - 1260 MHz, corresponding to a redshift range 0.127 < z < 0.449. BAO is one of the most powerful probes of cosmological parameters and BINGO was designed to detect the BAO signal to a level that makes it possible to put new constraints on the equation of state of dark energy. The telescope will be built in Paraíba, Brazil and consists of two \thicksim 40m mirrors, a feedhorn array of 50 horns, and no moving parts, working as a drift-scan instrument. It will cover a 15 ^{\circ} ∘ declination strip centered at \sim \delta ∼ δ =-15 ^{\circ} ∘ , mapping \sim ∼ 5400 square degrees in the sky. The BINGO consortium is led by University of São Paulo with co-leadership at National Institute for Space Research and Campina Grande Federal University (Brazil). Telescope subsystems have already been fabricated and tested, and the dish and structure fabrication are expected to start in late 2020, as well as the road and terrain preparation.

18.
Front Microbiol ; 12: 676436, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34163453

RESUMO

Vibrio parahaemolyticus, the leading cause of seafood-associated gastroenteritis worldwide, has a strong ability to form biofilms on surfaces. Quorum sensing (QS) is a process widely used by bacteria to communicate with each other and control gene expression via the secretion and detection of autoinducers. OpaR is the master QS regulator of V. parahaemolyticus operating under high cell density (HCD). OpaR regulation of V. parahaemolyticus biofilm formation has been reported, but the regulatory mechanisms are still not fully understood. bis-(3'-5')-cyclic di-GMP (c-di-GMP) is an omnipresent intracellular second messenger that regulates diverse behaviors of bacteria including activation of biofilm formation. In this work, we showed that OpaR repressed biofilm formation and decreased the intracellular concentration of c-di-GMP in V. parahaemolyticus RIMD2210633. The OpaR box-like sequences were detected within the regulatory DNA regions of scrA, scrG, VP0117, VPA0198, VPA1176, VP0699, and VP2979, encoding a group of GGDEF and/or EAL-type proteins. The results of qPCR, LacZ fusion, EMSA, and DNase I footprinting assays demonstrated that OpaR bound to the upstream DNA regions of scrA, VP0117, VPA0198, VPA1176, and VP0699 to repress their transcription, whereas it positively and directly regulated the transcription of scrG and VP2979. Thus, transcriptional regulation of these genes by OpaR led directly to changes in the intracellular concentration of c-di-GMP. The direct association between QS and c-di-GMP metabolism in V. parahaemolyticus RIMD2210633 would be conducive to precise control of gene transcription and bacterial behaviors such as biofilm formation.

19.
Small ; 17(40): e2008079, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34142431

RESUMO

Biomass-derived carbon materials (BCMs) are encountering the most flourishing moment because of their versatile properties and wide potential applications. Numerous BCMs, including 0D carbon spheres and dots, 1D carbon fibers and tubes, 2D carbon sheets, 3D carbon aerogel, and hierarchical carbon materials have been prepared. At the same time, their structure-property relationship and applications have been widely studied. This paper aims to present a review on the recent advances in the controllable preparation and potential applications of BCMs, providing a reference for future work. First, the chemical compositions of typical biomass and their thermal degradation mechanisms are presented. Then, the typical preparation methods of BCMs are summarized and the relevant structural management rules are discussed. Besides, the strategies for improving the structural diversity of BCMs are also presented and discussed. Furthermore, the applications of BCMs in energy, sensing, environment, and other areas are reviewed. Finally, the remaining challenges and opportunities in the field of BCMs are discussed.


Assuntos
Carbono , Biomassa
20.
Front Cell Infect Microbiol ; 11: 638087, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33816340

RESUMO

Pseudomonas aeruginosa is noted for its intrinsic antibiotic resistance and capacity of acquiring additional resistance genes. In this study, the genomes of nine clinical P. aeruginosa isolates were fully sequenced. An extensive genetic comparison was applied to 18 P. aeruginosa accessory genetic elements (AGEs; 13 of them were sequenced in this study and located within P. aeruginosa chromosomes) that were divided into four groups: five related integrative and conjugative elements (ICEs), four related integrative and mobilizable elements (IMEs), five related unit transposons, and two related IMEs and their two derivatives. At least 45 resistance genes, involved in resistance to 10 different categories of antibiotics and heavy metals, were identified from these 18 AGEs. A total of 10 ß-lactamase genes were identified from 10 AGEs sequenced herein, and nine of them were captured within class 1 integrons, which were further integrated into ICEs and IMEs with intercellular mobility, and also unit transposons with intracellular mobility. Through this study, we identified for the first time 20 novel MGEs, including four ICEs Tn6584, Tn6585, Tn6586, and Tn6587; three IMEs Tn6853, Tn6854, and Tn6878; five unit transposons Tn6846, Tn6847, Tn6848, Tn6849, and Tn6883; and eight integrons In1795, In1778, In1820, In1784, In1775, In1774, In1789, and In1799. This was also the first report of two resistance gene variants bla CARB-53 and catB3s, and a novel ST3405 isolate of P. aeruginosa. The data presented here denoted that complex transposition and homologous recombination promoted the assembly and integration of AGEs with mosaic structures into P. aeruginosa chromosomes.


Assuntos
Antibacterianos , Pseudomonas aeruginosa , Cromossomos/metabolismo , Integrons , Pseudomonas aeruginosa/genética , beta-Lactamases/genética
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