Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 92
Filtrar
1.
Nucleic Acids Res ; 51(D1): D1312-D1324, 2023 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-36300629

RESUMO

With the exponential growth of multi-omics data, its integration and utilization have brought unprecedented opportunities for the interpretation of gene regulation mechanisms and the comprehensive analyses of biological systems. IAnimal (https://ianimal.pro/), a cross-species, multi-omics knowledgebase, was developed to improve the utilization of massive public data and simplify the integration of multi-omics information to mine the genetic mechanisms of objective traits. Currently, IAnimal provides 61 191 individual omics data of genome (WGS), transcriptome (RNA-Seq), epigenome (ChIP-Seq, ATAC-Seq) and genome annotation information for 21 species, such as mice, pigs, cattle, chickens, and macaques. The scale of its total clean data has reached 846.46 TB. To better understand the biological significance of omics information, a deep learning model for IAnimal was built based on BioBERT and AutoNER to mine 'gene' and 'trait' entities from 2 794 237 abstracts, which has practical significance for comprehending how each omics layer regulates genes to affect traits. By means of user-friendly web interfaces, flexible data application programming interfaces, and abundant functional modules, IAnimal enables users to easily query, mine, and visualize characteristics in various omics, and to infer how genes play biological roles under the influence of various omics layers.


Assuntos
Bases de Dados Genéticas , Animais , Regulação da Expressão Gênica , Genoma , Bases de Conhecimento , Software , Multiômica
2.
J Am Chem Soc ; 146(22): 15428-15437, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38795044

RESUMO

Chemical recycling to monomers (CRM) offers a promising closed-loop approach to transition from current linear plastic economy toward a more sustainable circular paradigm. Typically, this approach has focused on modulating the ceiling temperature (Tc) of monomers. Despite considerable advancements, polymers with low Tc often face challenges such as inadequate thermal stability, exemplified by poly(γ-butyrolactone) (PGBL) with a decomposition temperature of ∼200 °C. In contrast, floor temperature (Tf)-regulated polymers, particularly those synthesized via the ring-opening polymerization (ROP) of macrolactones, inherently exhibit enhanced thermodynamic stability as the temperature increases. However, the development of those Tf regulated chemically recyclable polymers remains relatively underexplored. In this context, by judicious design and efficient synthesis of a biobased macrocyclic diester monomer (HOD), we developed a type of Tf -regulated closed-loop chemically recyclable poly(ketal-ester) (PHOD). First, the entropy-driven ROP of HOD generated high-molar mass PHOD with exceptional thermal stability with a Td,5% reaching up to 353 °C. Notably, it maintains a high Td,5% of 345 °C even without removing the polymerization catalyst. This contrasts markedly with PGBL, which spontaneously depolymerizes back to the monomer above its Tc in the presence of catalyst. Second, PHOD displays outstanding closed-loop chemical recyclability at room temperature within just 1 min with tBuOK. Finally, copolymerization of pentadecanolide (PDL) with HOD generated high-performance copolymers (PHOD-co-PPDL) with tunable mechanical properties and chemical recyclability of both components.

3.
Cancer Sci ; 115(2): 477-489, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38081591

RESUMO

Inhibition of cholesterol de novo synthesis (DNS) by statins has controversial effects on the treatment of hepatocellular carcinoma (HCC). High fatty acid conditions have been reported to limit the effect of statins on metabolism diseases. Whether high fatty acid conditions interfere with the effect of statins on HCC remains unclear. Here, we reported that inhibiting cholesterol DNS with atorvastatin promoted the oncogenic capabilities of diethylnitrosamine (DEN) in mice fed high fatty acid diets (HFD). The combined analysis of metabolomics and transcriptomics revealed that arachidonic acid (AA) metabolism was the most significant changed pathway between mice with and without atorvastatin treatment. In vitro, in the presence of AA precursor linoleic acid (LA), atorvastatin promoted the proliferation and migration ability of HCC cell lines. However, in the absence of LA, these phenomena disappeared. TCGA and tissue microarray examination revealed that prostaglandin e synthase 2 (PTGES2), a key enzyme in AA metabolism, was associated with the poor outcome of HCC patients. Overexpression of PTGES2 promoted the proliferation and migration of HCC cell lines, and knockdown of PTGES2 inhibited the proliferation and migration of cells. Additionally, atorvastatin upregulated PTGES2 expression by enhancing Sterol-regulatory element binding protein 2 (SREBP2)-mediated transcription. Knockdown of PTGES2 reversed the proliferation and migration ability enhanced by atorvastatin. Overall, our study reveals that a high fatty acid background is one of the possible conditions limiting the application of statins in HCC, under which statins promote the progression of HCC by enhancing SREBP2-mediated PTGES2 transcription.


Assuntos
Carcinoma Hepatocelular , Inibidores de Hidroximetilglutaril-CoA Redutases , Neoplasias Hepáticas , Humanos , Camundongos , Animais , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Ácidos Graxos/metabolismo , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Ácido Araquidônico/farmacologia , Prostaglandina-E Sintases/genética , Atorvastatina/farmacologia , Linhagem Celular Tumoral , Colesterol , Proliferação de Células
4.
Am J Physiol Gastrointest Liver Physiol ; 326(6): G697-G711, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38591127

RESUMO

Sterol regulatory element binding protein (SREBP) cleavage-activating protein (SCAP) is a widely expressed membrane glycoprotein that acts as an important modulator of lipid metabolism and inflammatory stress. N-glycosylation of SCAP has been suggested to modulate cancer development, but its role in nonalcoholic steatohepatitis (NASH) is poorly understood. In this study, the N-glycosylation of SCAP was analyzed by using sequential trypsin proteolysis and glycosidase treatment. The liver cell lines expressing wild-type and N-glycosylation sites mutated SCAP were constructed to investigate the N-glycosylation role of SCAP in regulating inflammation and lipid accumulation as well as the underlying mechanisms. The hepatic SCAP protein levels were significantly increased in C57BL/6J mice fed with Western diet and sugar water (WD + SW) and diabetic db/db mice, which exhibited typical liver steatosis and inflammation accompanied with hyperglycemia. In vitro, the enhanced N-glycosylation by high glucose increased the protein stability of SCAP and hence increased its total protein levels, whereas the ablation of N-glycosylation significantly decreased SCAP protein stability and alleviated lipid accumulation and inflammation in hepatic cell lines. Mechanistically, SCAP N-glycosylation increased not only the SREBP-1-mediated acetyl-CoA synthetase 2 (ACSS2) transcription but also the AMPK-mediated S659 phosphorylation of ACCS2 protein, causing the enhanced ACSS2 levels in nucleus and hence increasing the histone H3K27 acetylation (H3K27ac), which is a key epigenetic modification associated with NASH. Modulating ACSS2 expression or its location in the nuclear abolished the effects of SCAP N-glycosylation on H3K27ac and lipid accumulation and inflammation. In conclusion, SCAP N-glycosylation aggravates inflammation and lipid accumulation through enhancing ACSS2-mediated H3K27ac in hepatocytes.NEW & NOTEWORTHY N-glycosylation of SCAP exacerbates inflammation and lipid accumulation in hepatocytes through ACSS2-mediated H3K27ac. Our data suggest that SCAP N-glycosylation plays a key role in regulating histone H3K27 acetylation and targeting SCAP N-glycosylation may be a new strategy for treating nonalcoholic steatohepatitis (NASH).


Assuntos
Histonas , Peptídeos e Proteínas de Sinalização Intracelular , Metabolismo dos Lipídeos , Proteínas de Membrana , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica , Animais , Glicosilação , Histonas/metabolismo , Acetilação , Camundongos , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Metabolismo dos Lipídeos/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Masculino , Humanos , Fígado/metabolismo , Fígado/patologia
5.
Small ; 19(28): e2207196, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37026435

RESUMO

The exploring of economical, high-efficiency, and stable bifunctional catalysts for hydrogen evolution and oxygen evolution reactions (HER/OER) is highly imperative for the development of electrolytic water. Herein, a 3D cross-linked carbon nanotube supported oxygen vacancy (Vo )-rich N-NiMoO4 /Ni heterostructure bifunctional water splitting catalyst (N-NiMoO4 /Ni/CNTs) is synthesized by hydrothermal-H2 calcination method. Physical characterization confirms that Vo -rich N-NiMoO4 /Ni nanoparticles with an average size of ≈19 nm are secondary aggregated on CNTs that form a hierarchical porous structure. The formation of Ni and NiMoO4 heterojunctions modify the electronic structure of N-NiMoO4 /Ni/CNTs. Benefiting from these properties, N-NiMoO4 /Ni/CNTs drives an impressive HER overpotential of only 46 mV and OER overpotential of 330 mV at 10 mA cm-2 , which also shows exceptional cycling stability, respectively. Furthermore, the as-assembled N-NiMoO4 /Ni/CNTs||N-NiMoO4 /Ni/CNTs electrolyzer reaches a cell voltage of 1.64 V at 10 mA cm-2 in alkaline solution. Operando Raman analysis reveals that surface reconstruction is essential for the improved catalytic activity. Density functional theory (DFT) calculations further demonstrate that the enhanced HER/OER performance should be attributed to the synergistic effect of Vo and heteostructure that improve the conductivity of N-NiMoO4 /Ni/CNTs and facilitatethe desorption of reaction intermediates.

6.
Macromol Rapid Commun ; 44(6): e2200888, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36583944

RESUMO

Polymer dielectrics with high energy density are of urgent demand in electric and electronic devices, but the tradeoff between dielectric constant and breakdown strength is still unsolved. Herein, the synthesis and molar mass control of three alternating [1.1.1]propellane-(meth)acrylate copolymers, denoted as P-MA, P-MMA, and P-EA, respectively, are reported. These copolymers exhibit high thermal stability and are semi-crystalline with varied glass transition temperatures and melting temperatures. The rigid bicyclo[1.1.1]pentane units in the polymer backbone promote the orientational polarization of the polar ester groups, thus enhancing the dielectric constants of these polymers, which are 4.50 for P-EA, 4.55 for P-MA, and 5.11 for P-MMA at 10 Hz and room temperature, respectively. Moreover, the high breakdown strength is ensured by the non-conjugated nature of bicyclo[1.1.1]pentane unit. As a result, these copolymers show extraordinary energy storage performance; P-MA exhibits a discharge energy density of 9.73 J cm-3 at 750 MV m-1 and ambient temperature. This work provides a new type of promising candidates as polymer dielectrics for film capacitors, and offers an efficient strategy to improve the dielectric and energy storage properties by introducing rigid non-conjugated bicyclo[1.1.1]pentane unit into the polymer backbone.


Assuntos
Metanfetamina , Pentanos , Acrilatos , Polímeros
7.
BMC Biol ; 20(1): 136, 2022 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-35681201

RESUMO

BACKGROUND: Gene expression programs are intimately linked to the interplay of active cis regulatory elements mediated by chromatin contacts and associated RNAs. Genome-wide association studies (GWAS) have identified many variants in these regulatory elements that can contribute to phenotypic diversity. However, the functional interpretation of these variants remains nontrivial due to the lack of chromatin contact information or limited contact resolution. Furthermore, the distribution and role of chromatin-associated RNAs in gene expression and chromatin conformation remain poorly understood. To address this, we first present a comprehensive interaction map of nuclear dynamics of 3D chromatin-chromatin interactions (H3K27ac BL-HiChIP) and RNA-chromatin interactions (GRID-seq) to reveal genomic variants that contribute to complex skeletal muscle traits. RESULTS: In a genome-wide scan, we provide systematic fine mapping and gene prioritization from GWAS leading signals that underlie phenotypic variability of growth rate, meat quality, and carcass performance. A set of candidate functional variants and 54 target genes previously not detected were identified, with 71% of these candidate functional variants choosing to skip over their nearest gene to regulate the target gene in a long-range manner. The effects of three functional variants regulating KLF6 (related to days to 100 kg), MXRA8 (related to lean meat percentage), and TAF11 (related to loin muscle depth) were observed in two pig populations. Moreover, we find that this multi-omics interaction map consists of functional communities that are enriched in specific biological functions, and GWAS target genes can serve as core genes for exploring peripheral trait-relevant genes. CONCLUSIONS: Our results provide a valuable resource of candidate functional variants for complex skeletal muscle-related traits and establish an integrated approach to complement existing 3D genomics by exploiting RNA-chromatin and chromatin-chromatin interactions for future association studies.


Assuntos
Estudo de Associação Genômica Ampla , Locos de Características Quantitativas , Animais , Cromatina/genética , Músculo Esquelético , Polimorfismo de Nucleotídeo Único , RNA , Suínos
8.
Sensors (Basel) ; 23(3)2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36772587

RESUMO

The rapid development of the aviation industry has put forward higher and higher requirements for material properties, and the research on smart material structure has also received widespread attention. Smart materials (e.g., piezoelectric materials, shape memory materials, and giant magnetostrictive materials) have unique physical properties and excellent integration properties, and they perform well as sensors or actuators in the aviation industry, providing a solid material foundation for various intelligent applications in the aviation industry. As a popular smart material, piezoelectric materials have a large number of application research in structural health monitoring, energy harvest, vibration and noise control, damage control, and other fields. As a unique material with deformation ability, shape memory materials have their own outstanding performance in the field of shape control, low-shock release, vibration control, and impact absorption. At the same time, as a material to assist other structures, it also has important applications in the fields of sealing connection and structural self-healing. Giant magnetostrictive material is a representative advanced material, which has unique application advantages in guided wave monitoring, vibration control, energy harvest, and other directions. In addition, giant magnetostrictive materials themselves have high-resolution output, and there are many studies in the direction of high-precision actuators. Some smart materials are summarized and discussed in the above application directions, aiming at providing a reference for the initial development of follow-up related research.

9.
Int J Mol Sci ; 24(23)2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-38068940

RESUMO

The principal difference between hydroponics and other substrate cultivation methods is the flowing liquid hydroponic cultivation substrate. Our previous studies have revealed that a suitable flowing environment of nutrient solution promoted root development and plant growth, while an excess flow environment was unfavorable for plants. To explain the thigmomorphogenetic response of excess flow-induced metabolic changes, six groups of lettuce (Lactuca sativa L.), including two flow conditions and three time periods, were grown. Compared with the plants without flow, the plants with flow showed decreased root fresh weight, total root length, root surface area, and root volume but increased average root diameter and root density. The roots with flow had more upregulated metabolites than those without flow, suggesting that the flow may trigger metabolic synthesis and activity. Seventy-nine common differential metabolites among six groups were screened, and enrichment analysis showed the most significant enrichment in the arginine biosynthesis pathway. Arginine was present in all the groups and exhibited greater concentrations in roots with flow than without flow. It can be speculated from the results that a high-flowing environment of nutrient solution promotes arginine synthesis, resulting in changes in root morphology. The findings provide insights on root thigmomorphogenesis affected by its growing conditions and help understand how plants respond to environmental mechanical forces.


Assuntos
Plantas , Hidroponia/métodos , Nutrientes , Arginina
10.
Int J Mol Sci ; 24(17)2023 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-37686137

RESUMO

The Japanese encephalitis virus (JEV) is a mosquito-borne flavivirus that causes viral encephalitis in humans, pigs and other mammals across Asia and the Western Pacific. Genetic screening tools such as CRISPR screening, DNA sequencing and RNA interference have greatly improved our understanding of JEV replication and its potential antiviral approaches. However, information on exon and intron mutations associated with JEV replication is still scanty. CRISPR-Cas9-mediated cytosine base editing can efficiently generate C: G-to-T: A conversion in the genome of living cells. One intriguing application of base editing is to screen pivotal variants for gene function that is yet to be achieved in pigs. Here, we illustrate that CRISPR-Cas9-mediated cytosine base editor, known as AncBE4max, can be used for the functional analysis of calreticulin (CALR) variants. We conducted a CRISPR-Cas9-mediated cytosine base editing screen using 457 single guide RNAs (sgRNAs) against all exons and introns of CALR to identify loss-of-function variants involved in JEV replication. We unexpectedly uncovered that two enriched sgRNAs targeted the same site in intron-2 of the CALR gene. We found that mutating four consecutive G bases in the intron-2 of the CALR gene to four A bases significantly inhibited JEV replication. Thus, we established a CRISPR-Cas9-mediated cytosine-base-editing point mutation screening technique in pigs. Our results suggest that CRISPR-mediated base editing is a powerful tool for identifying the antiviral functions of variants in the coding and noncoding regions of the CALR gene.


Assuntos
Calreticulina , Vírus da Encefalite Japonesa (Espécie) , Vírus da Encefalite Japonesa (Subgrupo) , Animais , Humanos , Antivirais , Calreticulina/genética , Sistemas CRISPR-Cas/genética , Citosina , Vírus da Encefalite Japonesa (Espécie)/genética , Edição de Genes , Íntrons/genética , Mamíferos , Mutação , RNA Guia de Sistemas CRISPR-Cas , Suínos
11.
Plant Cell Rep ; 41(2): 473-487, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34981152

RESUMO

KEY MESSAGE: TaPGLP1, a chloroplast stromal 2-phosphoglycolate phosphatase of wheat, is an ATG8-interacting protein and undergoes autophagic degradation in starvation-treated wheat mesophyll protoplasts. Selective autophagy in plants has been shown to target diverse cellular cargoes including whole chloroplasts (Chlorophagy) and several chloroplast components (Piecemeal chlorophagy). Most cargoes of selective autophagy are captured by the autophagic machinery through their direct or indirect interactions with the autophagy-essential factor ATG8. Here, we reported a new ATG8-interacting cargo of piecemeal chlorophagy, the wheat photorespiratory 2-phosphoglycolate phosphatase TaPGLP1. The TaPGLP1-mCherry fusions expressed in wheat protoplasts located in the chloroplast stroma. Strikingly, these fusions are translocated into newly formed chloroplast surface protrusions after a long time incubation of protoplasts in a nutrition-free solution. Visualization of co-expressed TaPGLP1-mCherry and the autophagy marker GFP-TaATG8a revealed physical associations of TaPGLP1-mCherry-accumulating chloroplast protrusions with autophagic structures, implying the delivery of TaPGLP1-mCherry fusions from chloroplasts to the autophagic machinery. TaPGLP1-mCherry fusions were also detected in the GFP-TaATG8a-labelled autophagic bodies undergoing degradation in the vacuoles, which suggested the autophagic degradation of TaPGLP1. This autophagic degradation of TaPGLP1 was further demonstrated by the enhanced stability of TaPGLP1-mCherry in protoplasts with impaired autophagy. Expression of TaPGLP1-mCherry in protoplasts stimulated an enhanced autophagy level probably adopted by cells to degrade the over-produced TaPGLP1-mCherry fusions. Results from gene silencing assays showed the requirement of ATG2s and ATG7s in the autophagic degradation of TaPGLP1. Additionally, TaPGLP1 was shown to interact with ATG8 family members. Collectively, our data suggest that autophagy mediates the degradation of the chloroplast stromal protein TaPGLP1 in starvation-treated mesophyll protoplasts.


Assuntos
Autofagia/fisiologia , Cloroplastos/metabolismo , Monoéster Fosfórico Hidrolases/metabolismo , Proteínas de Plantas/metabolismo , Triticum/metabolismo , Proteínas Relacionadas à Autofagia/genética , Proteínas Relacionadas à Autofagia/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Células do Mesofilo/metabolismo , Monoéster Fosfórico Hidrolases/genética , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Transporte Proteico , Triticum/citologia , Triticum/genética , Proteína Vermelha Fluorescente
12.
Sensors (Basel) ; 23(1)2022 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-36616707

RESUMO

The applications of sensors in the aerospace industry are mostly concentrated in the middle and high frequencies, and low-frequency sensors often face the problems of low power and short working bandwidth. A lightweight, thin, high-power, low-frequency broadband transducer based on giant magnetostrictive material is designed. The design and optimization processes of the core components are introduced and analyzed emphatically. The finite element simulation results are validated by the PSV-100 laser vibration meter. Three basic configurations of the work panel are proposed, and the optimal configuration is determined by modal, acoustic, and vibration coupling analyses. Compared with the original configuration, it is found that the lowest resonant frequency of the optimal configuration is reduced by 24.6% and the highest resonant frequency within 2000 Hz is 1744.9 Hz, which is 54.2% higher than that of the original configuration. This greatly improves the vibration power and operating frequency range of the transducer. Then, the honeycomb structure is innovatively applied to the work panel, and it is verified that the honeycomb structure has a great effect on the vibration performance of the work panel. By optimizing the size of the honeycomb structure, it is determined that the honeycomb structure can improve the vibration power of the work panel to its maximum value when the distance between the half-opposite sides of the hexagon is H = 3.5 mm. It can reduce the resonant frequency of the work panel; the lowest resonant frequency is reduced by 12.8%. At the same time, the application of a honeycomb panel structure can reduce the weight of the transducer.

13.
Pharm Biol ; 60(1): 1055-1062, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35634726

RESUMO

CONTEXT: Mulisan decoction (MLS) is a classic formula of traditional Chinese medicine for treating hyperhidrosis. The mechanism remains unclear. OBJECTIVE: To investigate the antiperspirant effect and underlying mechanisms of MLS. MATERIALS AND METHODS: Fifty rats were divided into control, model, and three doses of MLS intervention groups (n = 10). Rats except for control group were induced diseases features of the applicable scope of MLS via i.p. reserpine (0.5 mg/kg/d) for 10 days. From day 11, MLS groups were administrated orally MLS at 0.6, 3, and 15 g/kg once a day for 14 days, respectively. After the last administration, sweating was induced in all rats via s.c. pilocarpine (25 mg/kg), the right hind foot of rats was stained, and sweat point numbers were observed. Rat serum was collected to detect IL-2, IL-6, IFN-γ, and TNF-α. Rat plasma was collected for endogenous metabolite analysis via UPLC-QE-Focus-MS. RESULTS: Rats treated with MLS presented a significant decrease in sweat point numbers (13.5%), increase in body weight (13.2%), and promotion in the balance of Th1/Th2 cytokine ratio via increasing IL-2 (38.3%), IFN-γ (20.1%), and TNF-α (22.0%) and decreasing IL-6 (24.7%) compared with the model group (p < 0.05). Plasma metabolomics disclosed 15 potential biomarkers related to model rats, of which two could be significantly reversed by MLS (p < 0.05). The involved pathways were pantothenate and CoA biosynthesis, and porphyrin metabolism. CONCLUSIONS: MLS demonstrated a good antiperspirant effect and metabolism improvement. These findings inspire more clinical study validation on immune improvement and antiperspirant effect.


Assuntos
Antiperspirantes , Hiperidrose , Medicina Tradicional Chinesa , Animais , Antiperspirantes/farmacologia , Hiperidrose/tratamento farmacológico , Interleucina-2 , Interleucina-6 , Metabolômica , Ratos , Fator de Necrose Tumoral alfa
14.
Opt Express ; 28(17): 24550-24559, 2020 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-32906994

RESUMO

Soliton buildup dynamics in ultrafast fiber lasers are one of the most significant topics in both the fundamental and industrial fields. In this work, by using the dispersive Fourier transformation technique, the real-time spectral evolution of soliton buildup dynamics were investigated in the all-polarization-maintaining Yb-doped fiber laser, which is mode-locked by nonlinear polarization evolution technique through the cross splicing method. It was experimentally confirmed that the same stable soliton state could be achieved through different soliton starting processes because of the initial random noises. In one case, the maximum pulse energy during the soliton starting process could reach ∼15 times the stable pulse energy, which results in the spectral chaotic state and temporal shift. We also provide another soliton buildup case with the same cavity parameters, which illustrates more moderate evolution. It involves smaller energy variation and no complex transition state. These results would deepen our understanding of soliton buildup dynamics and be beneficial for the applications of ultrafast fiber lasers.

15.
Int J Syst Evol Microbiol ; 69(4): 1016-1023, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30702419

RESUMO

Cells of bacterial strains 4 G-K06T and 4MSK11T, isolated from soil samples collected from monsoon evergreen broad-leaved forest of the Dinghushan Mountain (112° 31' E 23° 10' N), Guangdong Province, PR China, were Gram-stain-negative, aerobic, non-spore-forming, non-motile and rod-shaped. Strain 4 G-K06T grew at 10-37 °C, pH 3.5-7.5 and 0-3.5 % (w/v) NaCl; while 4MSK11T grew at 4-42 °C, pH 3.5-7.5 and 0-2.5 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed strain 4 G-K06T formed a clade with Dyellaflagellata 4 M-K16T, Dyella acidisoli 4M-Z03T, Dyellahumi DHG40T and Dyellanitratireducens DHG59T, while strain 4MSK11T formed a clade with Dyellacaseinilytica DHOB09T and Dyellamobilis DHON07T, both within the genus Dyella. The result of the partial atpD, gyrB and lepA gene sequence analysis supported the conclusion based on 16S rRNA gene sequence analysis, which showed that these two strains represent two novel species of Dyella. The average nucleotide identity and digital DNA-DNA hybridization value for the whole genomes were 75.0-79.0 and 20.3-22.6 % between strains 4 G-K06T, 4MSK11T and those described Dyella species with genome sequences; while the DNA-DNA hybridization rates between strains 4 G-K06T, 4MSK11T and closely related Dyella species (without genome sequence) were 29.5-41.8 %. The major cellular fatty acids of these two strains were iso-C15 : 0, iso-C16 : 0 and iso-C17 : 1ω9c, while the major polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and several unidentified phospholipids and aminophospholipids. The only ubiquinone of these two strains was ubiquinone-8. The DNA G+C contents of 4 G-K06T and 4MSK11T were 60.4 and 61.3 mol%, respectively. On the basis of the evidence presented here, strains 4 G-K06T and 4MSK11T represent two novel species of the genus Dyella, for which the names Dyella monticola sp. nov. (type strain 4 G-K06T=LMG 30268T=GDMCC 1.1188T) and Dyella psychrodurans sp. nov. (type strain 4MSK11T=KCTC 62280T=GDMCC 1.1185T) are proposed.


Assuntos
Florestas , Gammaproteobacteria/classificação , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Gammaproteobacteria/isolamento & purificação , Genes Bacterianos , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/química
16.
Eur Radiol ; 29(7): 3678-3685, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30888481

RESUMO

OBJECTIVE: To explore the image quality (IQ) and diagnostic value of 70 kVp turbo high-pitch coronary CT angiography (THP-CCTA) using automated tube voltage selection (ATVS) and 30 mL of low-concentration contrast agent. METHODS: Patients who underwent 70 kVp THP-CCTA using ATVS with 30 mL of contrast agent (group A) were prospectively enrolled, and those who underwent conventional CCTA (100/120 kVp, prospective sequential mode with 65-75 mL of contrast agent) (group B) were retrospectively selected for study. IQ was assessed subjectively on a 5-point scale, and diagnostic value was assessed based on invasive coronary angiography as the gold standard. Heart rate (HR), HR fluctuation (HRF), body mass index (BMI), effective radiation dose (ED), and iodine uptake (IU) were recorded. RESULTS: A total of 796 patients (398/398 in groups A/B) were included. Between-group differences in age, gender, BMI, HR, HRF, and IQ values were not significant. The ED/IU values were 0.3 ± 0.1 mSv/9.0 ± 0.0 g and 5.8 ± 1.8 mSv/22.9 ± 1.0 g in groups A and B, respectively (p < 0.01). The sensitivity, specificity, positive and negative predictive values, and accuracy of THP-CCTA for the diagnosis of ≥ 50% stenosis were 94.8%, 97.5%, 92.0%, 98.4%, and 96.9% respectively. The mean HR and coronary calcium score were independent predictors of diagnostic image quality, and the best cutoff values were 71.5 bpm and 444.1 respectively. CONCLUSION: This third-generation dual-source CT imaging modality, a 70-kVp THP-CCTA system using ATVS with 30 mL of low-concentration contrast agent, produces high-quality images with high diagnostic accuracy for significant stenosis, with ultra low ED and IU. This technique was most promising in individuals with an HR < 71.5 bpm and coronary calcium score < 444.1. KEY POINTS: • Turbo high-pitch CCTA using 70 kVp via automated tube voltage selection and 30 mL of low-concentration contrast agent is feasible. • This protocol provides high diagnostic accuracy for significant coronary stenosis and reduces radiation doses and iodine uptake significantly. • This protocol was most promising in individuals with an HR < 71.5 bpm and coronary calcium score < 444.1.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Meios de Contraste/farmacologia , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reprodutibilidade dos Testes , Adulto Jovem
17.
Neurochem Res ; 43(2): 430-440, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29147958

RESUMO

Adult hippocampal neurogenesis plays a pivotal role in learning and memory. The suppression of hippocampal neurogenesis induced by an increase of oxidative stress is closely related to cognitive impairment. Neural stem cells which persist in the adult vertebrate brain keep up the production of neurons over the lifespan. The balance between pro-oxidants and anti-oxidants is important for function and surviving of neural stem cells. Ginsenoside Rg1 is one of the most active components of Panax ginseng, and many studies suggest that ginsenosides have antioxidant properties. This research explored the effects and underlying mechanisms of ginsenoside Rg1 on protecting neural stem cells (NSCs) from oxidative stress. The sub-acute ageing of C57BL/6 mice was induced by subcutaneous injection of D-gal (120 mg kg-1 day-1) for 42 day. On the 14th day of D-gal injection, the mice were treated with ginsenoside Rg1 (20 mg kg-1 day-1, intraperitoneally) or normal saline for 28 days. The study monitored the effects of Rg1 on proliferation, senescence-associated and oxidative stress biomarkers, and Akt/mTOR signalling pathway in NSCs. Compared with the D-gal group, Rg1 improved cognitive impairment induced by D-galactose in mice by attenuating senescence of neural stem cells. Rg1 also decreased the level of oxidative stress, with increased the activity of superoxide dismutase and glutathione peroxidase in vivo and in vitro. Rg1 furthermore reduced the phosphorylation levels of protein kinase B (Akt) and the mechanistic target of rapamycin (mTOR) and down-regulated the levels of downstream p53, p16, p21 and Rb in D-gal treated NSCs. The results suggested that the protective effect of ginsenoside Rg1 on attenuating cognitive impairment in mice and senescence of NSCs induced by D-gal might be related to the reduction of oxidative stress and the down-regulation of Akt/mTOR signaling pathway.


Assuntos
Disfunção Cognitiva/tratamento farmacológico , Galactose/farmacologia , Ginsenosídeos/metabolismo , Células-Tronco Neurais/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Disfunção Cognitiva/metabolismo , Glutationa Peroxidase/metabolismo , Camundongos Endogâmicos C57BL , Proteínas Proto-Oncogênicas c-akt/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo
18.
Int J Syst Evol Microbiol ; 67(3): 736-743, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27930272

RESUMO

Bacterial strains 4M-Z03T, 4M-K16T and DHG59T were isolated from forest soil samples collected from the Dinghushan Biosphere Reserve, Guangdong Province, PR China (112° 31' E 23° 10' N). The three strains grew well at 28 °C, pH 5.0-6.0 on R2A medium. On the basis of 16S rRNA gene sequence analysis, the three strains, together with Dyella humi DHG40T, formed a distinct phyletic clade within the genus Dyella, and the sequence similarities between any strains of the clade ranged from 97.8 to 98.5 %. Sequence analysis of concatenated partial gyrB, lepA and recA gene sequences also strongly suggested that the three strains represented three novel species of the genus Dyella. The respiratory lipoquinone of the three strains was ubiquinone-8, and their DNA G+C content was 58.2-59.0 mol%. The fatty acid profiles differed substantially among these three strains, although they had two common major fatty acids, iso-C15 : 0 and iso-C17 : 1ω9c. The DNA-DNA relatedness among the three strains and the type strains of the closest species of the genus Dyella examined was lower than 50 %. The results of genotypic and phenotypic characterization presented above demonstrate that the three strains examined represent three novel species of the genus Dyella, for which the names Dyella acidisoli sp. nov. (type strain 4M-Z03T=NBRC 111980T=KCTC 52131T), Dyella flagellata sp. nov. (type strain 4M-K16T=NBRC 111981T=KCTC 52130T) and Dyella nitratireducens sp. nov. (type strain DHG59T=NBRC 111472T=LMG 29201T=CGMCC 1.15439T) are proposed.


Assuntos
Florestas , Filogenia , Microbiologia do Solo , Xanthomonadaceae/classificação , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Hibridização de Ácido Nucleico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/química , Xanthomonadaceae/genética , Xanthomonadaceae/isolamento & purificação
19.
Int J Syst Evol Microbiol ; 67(2): 212-217, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27902218

RESUMO

A Gram-stain-negative, aerobic, motile, rod-shaped bacterium, designated 7M-Z19T, was isolated from a soil sample collected from a Pinus massoniana forest of Dinghushan Biosphere Reserve, Guangdong Province, PR China. Strain 7M-Z19T grew at pH 4.5-7.5 (optimum pH 6.0-6.5), 10 to 37 °C (optimum 28 °C) and NaCl concentration up to 2.0 % (optimum 0 %, w/v). iso-C17 : 0, C18 : 1ω7c and C19 : 0ω8c cyclo were the major fatty acids (>10 %) while ubiquinone-10 was the only respiratory quinone detected in 7M-Z19T. The polar lipids of the strain consisted of phosphatidylethanolamine, phosphatidyldimethylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, six unidentified aminophospholipids, three unidentified phospholipids, six unidentified lipids and a glycolipid. The DNA G+C content was 65.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the isolate formed a distinct lineage with Dongia mobilis and Dongia rigui within the family Rhodospirillaceae, but with a low sequence similarity of 92.7 and 92.0 %, respectively. On the basis of phylogenetic, phenotypic, physiological and chemotaxonomic distinctiveness, strain 7M-Z19T should be placed in the family Rhodospirillaceae as a representative of a novel genus and species, for which the name Aliidongia dinghuensis gen. nov., sp. nov., is proposed. The type strain of the type species is 7M-Z19T (=NBRC 112240T=KCTC 52134T=CGMCC 1.15725T).


Assuntos
Florestas , Hidroxibutiratos/metabolismo , Filogenia , Poliésteres/metabolismo , Rhodospirillaceae/classificação , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Fosfolipídeos/química , Pinus , RNA Ribossômico 16S/genética , Rhodospirillaceae/genética , Rhodospirillaceae/isolamento & purificação , Análise de Sequência de DNA , Ubiquinona/química
20.
Int J Mol Sci ; 17(9)2016 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-27618015

RESUMO

The metanephric mesenchyme (MM) cells are a subset of kidney progenitor cells and play an essential role in mesenchymal-epithelial transition (MET), the key step of nephron generation. Six2, a biological marker related to Wnt signaling pathway, promotes the proliferation, inhibits the apoptosis and maintains the un-differentiation of MM cells. Besides, LiCl is an activator of Wnt signaling pathway. However, the role of LiCl in cellular regulation of MM cells remains unclear, and the relationship between LiCl and Six2 in this process is also little known. Here, we performed EdU assay and flow cytometry assay to, respectively, detect the proliferation and apoptosis of MM cells treated with LiCl of increasing dosages. In addition, reverse transcription-PCR (RT-PCR) and Western-blot were conducted to measure the expression of Six2 and some maker genes of Wnt and bone-morphogenetic-protein (BMP) signaling pathway. Furthermore, luciferase assay was also carried out to detect the transcriptional regulation of Six2. Then we found LiCl promoted MM cell proliferation at low-concentration (10, 20, 30, and 40 mM). The expression of Six2 was dose-dependently increased in low-concentration (10, 20, 30, and 40 mM) at both mRNA and protein level. In addition, both of cell proliferation and Six2 expression in MM cells declined when dosage reached high-concentration (50 mM). However, Six2 knock-down converted the proliferation reduction at 50 mM. Furthermore, Six2 deficiency increased the apoptosis of MM cells, compared with negative control cells at relative LiCl concentration. However, the abnormal rise of apoptosis at 30 mM of LiCl concentration implies that it might be the reduction of GSK3ß that increased cell apoptosis. Together, these demonstrate that LiCl can induce the proliferation and apoptosis of MM cells coordinating with Six2.


Assuntos
Apoptose/genética , Proliferação de Células/genética , Proteínas de Homeodomínio/metabolismo , Cloreto de Lítio/farmacologia , Fatores de Transcrição/metabolismo , Animais , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células HEK293 , Proteínas de Homeodomínio/genética , Humanos , Camundongos , Fatores de Transcrição/genética , Via de Sinalização Wnt
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA