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1.
Org Lett ; 2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32052975

RESUMO

The first photoredox-catalyzed defluoroborylation of polyfluoroarenes with NHC-BH3 has been facilely achieved at room temperature via a single-electron-transfer (SET)/radical addition pathway. This new strategy makes full use of the advantage of photoredox catalysis to generate the key boryl radical via direct activation of a B-H bond. Good functional group tolerance and high regioselectivity offer this protocol incomparable advantages in preparing a wide array of valuable polyfluoroarylboron compounds. Moreover, both computational and experimental studies were performed to illustrate the reaction mechanism.

2.
Mol Med Rep ; 21(1): 429-437, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31746387

RESUMO

The present study examined whether lipoxin A4 (LXA4) increases the expression of HO­1, and inhibits the production of interleukin 6 (IL­6) and monocyte chemotactic protein 1 (MCP­1) in LXA4­induced protection during hyperoxia­induced injury in murine lung epithelial cells (MLE­12) and what signal pathway may participate in the actions of LXA4 inhibiting IL­6 and MCP­1. MLE­12 cells were exposed to air or hyperoxia with or without pretreatment with LXA4, Zinc protoporphyrin IX (ZnPP­IX), IL­6, anti­IL­6, MCP­1, anti­MCP­1, inhibitors of p38 mitogen­activated protein kinase (p38 MAPK), protein kinase B (Akt) and extracellular signal­regulated kinase 1/2 (ERK1/2) signaling pathways. The cell survival rates, cell viability, apoptosis rates, expression of superoxide dismutase (SOD), heme oxygenase­1 (HO­1), IL­6 and MCP­1, and the activations of p38 MAPK, ERK1/2 and Akt were measured. LXA4 significantly increased the cell survival rates, cell viability, SOD levels and HO­1 expression, reduced the apoptosis rates, and inhibited the MCP­1 and IL­6 levels induced by hyperoxia in cells. ZnPP­IX, an inhibitor of HO­1, blocked LXA4­induced protection on cell viability in cells exposed to hyperoxia. Anti­IL­6 and anti­MCP­1 improved the cell viability of cells exposed to hyperoxia. Inhibition of p38 MAPK and ERK1/2 blocked the expression of MCP­1 and IL­6 induced by hyperoxia. LXA4 inhibited the activation of p38 MAPK and ERK1/2 induced by hyperoxia, and increased the activation of the Akt signaling pathway, which was inhibited by hyperoxia. Therefore, LXA4 attenuated hyperoxia­induced injury in MLE­12 cells via the upregulation of HO­1 expression. The protection of LXA4 in hyperoxia­induced cell injury may be associated with the downregulation IL­6 and MCP­1 levels via the inhibition of the p38 MAPK and ERK1/2 signaling pathways.

3.
Org Lett ; 22(2): 488-492, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-31873033

RESUMO

We herein report a phosphine-mediated domino process of MBH-type reaction/umpolung γ-addition through the rational integration of the privileged reactivities of alkynoate. Simply by manipulating the nucleophilic reagent, the developed protocol offers a facile, diversity-oriented construction of a wide range of three-substituted coumarins.

4.
Artigo em Inglês | MEDLINE | ID: mdl-31849140

RESUMO

A photoinduced SET process enables the direct B-H bond activation of NHC-boranes. In contrast to common hydrogen atom transfer (HAT) strategies, this photoinduced reaction simply takes advantage of the beneficial redox potentials of NHC-boranes, thus obviating the need for extra radical initiators. The resulting NHC-boryl radical was used for the borylation of a wide range of α-trifluoromethylalkenes and alkenes with diverse electronic and structural features, providing facile access to highly functionalized borylated molecules. Labeling and photoquenching experiments provide insight into the mechanism of this photoinduced SET pathway.

6.
Phytochem Anal ; 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31512326

RESUMO

INTRODUCTION: Polygoni Orientalis Fructus (POF) is a clinically effective Chinese medicine. Raw POF (RPOF) and POF Tostus (POFT) are used separately in clinics. However, incomplete progress has been made on quality control. OBJECTIVE: To establish a comprehensive method for quality assessment of RPOF and POFT and to discriminate these two varieties. METHODOLOGY: High-performance liquid chromatography combined with the diode array detector (HPLC-DAD) methods were developed for fingerprinting and quantitative analysis of seven major compounds in RPOF and POFT, and the main components were determined by HPLC-DAD coupled with Fourier-transform ion cyclotron resonance-mass spectrometry. Chemometric approaches were performed to discriminate RPOF and POFT and to screen discriminatory components. RESULTS: Fingerprints were established and 12 common peaks were identified, cannabisin G and cannabisin E were firstly identified from POF. In quantitative analysis, all analytes showed good regression (R > 0.9996) within test ranges and the recovery of the method was in the range 96.6-104.3%. Fingerprints in conjunction with similarity analysis and hierarchical clustering analysis (HCA) demonstrated the consistent quality of RPOF and showed a clear discrimination between RPOF and POFT. Principal component analysis, partial least-squares discriminant analysis, and heatmap-HCA on quantitative data not only gave a clear differentiation between RPOF and POFT, but they also suggested that quercetin, 3,5,7-trihydroxychromone, and N-trans-feruloyltyramine acted as the main factors responsible for the sample differences. CONCLUSIONS: Chromatographic analysis in combination with chemometric analysis provides a simple and reliable method of comparing and evaluating the qualities of RPOF and POFT.

7.
Artigo em Inglês | MEDLINE | ID: mdl-31383652

RESUMO

In this study, we analyzed the global metabolomic changes associated with Toxoplasma gondii infection in mice in the presence or absence of sulfadiazine sodium (SDZ) treatment. BALB/c mice were infected with T. gondii GT1 strain and treated orally with SDZ (250 µg/ml in water) for 12 consecutive days. Mice showed typical manifestations of illness at 20 days postinfection (dpi); by 30 dpi, 20% had survived and developed latent infection. We used ultraperformance liquid chromatography-mass spectrometry to profile the serum metabolomes in control (untreated and uninfected) mice, acutely infected mice, and SDZ-treated and infected mice. Infection induced significant perturbations in the metabolism of α-linolenic acid, purine, pyrimidine, arginine, tryptophan, valine, glycerophospholipids, and fatty acyls. However, treatment with SDZ seemed to alleviate the serum metabolic alterations caused by infection. The restoration of the serum metabolite levels in the treated mice was associated with better clinical outcomes. These data indicate that untargeted metabolomics can reveal biochemical pathways associated with restoration of the metabolic status of T. gondii-infected mice following SDZ treatment and could be used to monitor responses to SDZ treatment. This study provides a new systems approach to elucidate the metabolic and therapeutic effects of SDZ in the context of murine toxoplasmosis.

8.
Int J Mol Med ; 44(4): 1399-1413, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31432143

RESUMO

At present, thousands of circular RNAs (circRNAs) have been found in cancer and various tissues from different species. However, the expression of circRNAs during rat lung development remains largely unknown. In the present study, circRNA expression profiles were screened in three mixed rat lung tissues at 3 time­points [embryonic day (E) 19, E21 and post­natal (P) day 3] during fetal rat development with circRNA high­throughput sequencing. Preliminary results were verified by reverse transcription­PCR (RT­PCR) at 4 time­points (E16, E19, E21 and P3). A total of 375 circRNAs were differently expressed in E19 vs. E21 (fold change ≥1.5; P<0.05). At the same time, a total of 358 circRNAs were differently expressed in E21 vs. P3 (fold change ≥1.5; P<0.05). A total of 3 circRNAs (rno_circ:chr7:24777879­24784993, rno_circ:chr14:14620910­14624933 and rno_circ:chr3:1988750­â€‹1998592) were characterized by having consistent fold changes (≥1.5) between 3 time­points (E19, E21 and P3) and were selected for RT­PCR at 4 time­points (E16, E19, E21 and P3). Subsequently, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis of parent genes of the differentially expressed circRNAs revealed that these circRNAs may serve important roles in lung development. The present results support that these new found circRNAs participate in lung development. Furthermore, these findings may help to clarify the physiopathological mechanism of normal rat lung development, and may further provide a physiopathological basis of lung developmental diseases.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Pulmão/embriologia , Pulmão/metabolismo , Organogênese/genética , /genética , Animais , Biologia Computacional/métodos , Feminino , Imunofluorescência , Perfilação da Expressão Gênica , Ontologia Genética , Redes Reguladoras de Genes , Pulmão/citologia , MicroRNAs/genética , Gravidez , Ratos
9.
Adv Mater ; 31(41): e1904069, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31420926

RESUMO

Metasurfaces are artificially engineered ultrathin structures that can finely tailor and control electromagnetic wavefronts. There is currently a strong interest in exploring their capability to lift some fundamental limitations dictated by Lorentz reciprocity, which have strong implications in communication, heat management, and energy harvesting. Time-varying approaches have emerged as attractive alternatives to conventional schemes relying on magnetic or nonlinear materials, but experimental evidence is currently limited to devices such as circulators and antennas. Here, the recently proposed concept of space-time-coding digital metasurfaces is leveraged to break reciprocity. Moreover, it is shown that such nonreciprocal effects can be controlled dynamically. This approach relies on inducing suitable spatiotemporal phase gradients in a programmable way via digital modulation of the metasurface-elements' phase repsonse, which enable anomalous reflections accompanied by frequency conversions. A prototype operating at microwave frequencies is designed and fabricated for proof-of-concept validation. Measured results are in good agreement with theory, hence providing the first experimental evidence of nonreciprocal reflection effects enabled by space-time-modulated digital metasurfaces. The proposed concept and platform set the stage for "on-demand" realization of nonreciprocal effects, in programmable or reconfigurable fashions, which may find several promising applications, including frequency conversion, Doppler frequency illusion, optical isolation, and unidirectional transmission.

10.
Ital J Pediatr ; 45(1): 105, 2019 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-31426828

RESUMO

Deleterious consequences of the management of respiratory distress syndrome (RDS) with invasive ventilation have led to more in-depth investigation of non-invasive ventilation (NIV) modalities. NIV has significantly and positively altered the treatment outcomes and improved mortality rates of preterm infants with RDS. Among the different NIV modes, nasal intermittent positive pressure ventilation (NIPPV) has shown considerable benefits compared to nasal continuous positive airway pressure (NCPAP). Despite reports of heated humidified high-flow nasal cannula's (HHHFNC) non-inferiority compared to NCPAP, some trials have been terminated due to high treatment failure rates with HHHFNC use. Moreover, RDS management with the combination of INSURE (INtubation SURfactant Extubation) technique and NIV ensures higher success rates. This review elaborates on the currently used various modes of NIV and novel techniques are also briefly discussed.


Assuntos
Ventilação não Invasiva , Síndrome do Desconforto Respiratório do Recém-Nascido/terapia , Humanos , Recém-Nascido , Recém-Nascido Prematuro
11.
Nat Prod Res ; : 1-8, 2019 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-31342796

RESUMO

Three new flavonoids, pinocembrin-7-O-[3″-O-galloyl]-ß-D-glucose (1), pinocembrin-7-O-[2″-O-galloyl-4″,6″-hexahydroxydiphenoyl]-ß-D-glucose (2), 2',6'-dihydroxydihydrochalcone-4'-O-[2″-O-galloyl-4″,6″-hexahydroxydiphenoyl]-ß-D-glucopyranoside (3), and 12 known compounds (4-15) were isolated from Penthorum Chinense Pursh. The structures of all compounds were established mainly by NMR and MS experiments as well as the necessary chemical evidence. The anti-hyperlipidemic activities of the three new flavonoids were predicted by molecular docking.

12.
Mater Sci Eng C Mater Biol Appl ; 103: 109848, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31349437

RESUMO

Graphene nanoplatelets (GNPs), multiwalled carbon nanotube (MWCNTs) and chitosan (CS) were self-assembled by a facile one-step hydrothermal reaction to obtain novel MWCNTs-CS enfolded GNPs (GNPs-MWCNTs-CS) composite. Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), UV-visible (UV-vis) absorption spectroscopy and zeta potential analysis were employed to characterize the morphology, surface composition, interaction, surface charge and stability of the GNPs-MWCNTs-CS composite. The electrochemical behaviors of GNPs-MWCNTs-CS composite modified glassy carbon electrode (GNPs-MWCNTs-CS/GCE) were investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The GNPs-MWCNTs-CS/GCE was used for fast and high sensitive determination of bisphenol A (BPA) by differential pulse voltammetry (DPV). Under the optimum conditions, the calibration curve obtained is linear for the current versus the BPA concentration in the range 0.1-100 µM with a detection limit of 0.05 nM (signal-to-noise ratio of 3, S/N = 3). The between-sensor reproducibility was 1.29% (n = 6) for 0.04 mM BPA. The proposed GNPs-MWCNTs-CS/GCE based sensor showed high resistance to interference, good repeatability and excellent reproducibility. Trace BPA in milk samples could also be reliably determined.


Assuntos
Compostos Benzidrílicos/análise , Técnicas Eletroquímicas , Grafite/química , Leite/química , Nanotubos de Carbono/química , Fenóis/análise , Animais , Sensibilidade e Especificidade
13.
Mol Med Rep ; 19(6): 4980-4988, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31059017

RESUMO

Deficiency of surfactant proteins (SPs) is the main cause of respiratory distress syndrome (RDS) and chronic lung diseases. Our previous study demonstrated that miR­431 was differentially expressed between infants with RDS and infants without RDS using microarray analysis. However, the potential role of miR­431 in the development of lung function is still unknown. In the present study, the morphological characteristics of lung tissues and the expression levels of miR­431 were examined at three time points of rat lung development [gestational days 19 and 21 (E19, and E21) and postnatal day (P3)]. The protein and mRNA levels of SMAD4 and SPs (SP­A, SP­B, SP­C and SP­D) were also validated by reverse transcription­quantitative polymerase chain reaction (RT­qPCR) and western blot analysis, respectively. The expression levels of miR­431 were gradually decreased over time periods of E19, E21 and P3, as determine using RT­qPCR and fluorescence in situ hybridization. Dual luciferase­reporter assays revealed that SMAD4 is a direct target of miR­431. The mRNA and protein expression levels of SMAD4 and SPs increased gradually in rat lung tissues from E19 to P3. The order of magnitude was as follows: E19, E21 and P3. The present study demonstrated that the expression level of miR­431 decreased in the order of E19, E21 and P3 during rat lung development. The target gene of miR­431, SMAD4, was negatively regulated by miR­431, and its expression levels in the rat lung tissue increased from E19 to the P3. Surfactant synthesis was further increased over the E19 to P3 time period. Further studies are required to determine how miR­431 regulates pulmonary surfactant synthesis by targeting SMAD4.


Assuntos
Pulmão/crescimento & desenvolvimento , MicroRNAs/metabolismo , Regiões 3' não Traduzidas , Animais , Animais Recém-Nascidos , Sequência de Bases , Feminino , Pulmão/metabolismo , Pulmão/patologia , MicroRNAs/genética , Microscopia Eletrônica , Gravidez , Proteínas Associadas a Surfactantes Pulmonares/genética , Proteínas Associadas a Surfactantes Pulmonares/metabolismo , Ratos , Ratos Sprague-Dawley , Alinhamento de Sequência , Proteína Smad4/química , Proteína Smad4/genética , Proteína Smad4/metabolismo
14.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 27(2): 594-599, 2019 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-30998176

RESUMO

OBJECTIVE: To investigate the effect of microvascular endothelial cells (MEC) on the proliferation of hematopoictic stem cells (HSC) under different culture conditions in vitro. METHODS: The MEC from lung tissue of C57BL/6 mice and the HSC from bone marrow of GFP mice were used for non-contact co-culture, 2 D contact co-culture, at same time the single MEC and single HSC culture were seted up and were used as control group. The cell counting and CCK-8 method were used to detect and compare the proliferation levels of suspension cells in different groups on day 1, 3, 5 and 7. RESULTS: MEC presented adherent growth. In process of cell culture in vitro, the number of suspension cells in MEC and HSC co-culture group and single HSC culture group increased, the suspension cells in 2D contact and non-contact co-culture groups more early gated into logarithmic growth phase as compared with suspension cells in control group, the proliferation level of suspention cells in 2D contact culture group was higher than that in non-contact co-culture group and single HSC culture group (P<0.05), the proliferation level of suspension cells in non-contact co-culture group was higher than that in single HSC culture group (P<0.05). CONCLUSION: The culture of HSC in vitro can proliferate HSC, MEC can promote the proliferation of HSC, MEC also can promote the HSC proliferation by non-contact co-culture in vitro, which relates with the effect of cytokines secreted from MEC; the effect of MEC and HSC contact co-culture on the proliferation of HSC is stronger than that of non-contact co-culture, which relates with the regulation of cell-cell contact.


Assuntos
Medula Óssea , Células-Tronco Hematopoéticas , Animais , Células da Medula Óssea , Proliferação de Células , Células Endoteliais , Camundongos , Camundongos Endogâmicos C57BL
15.
Org Lett ; 21(8): 2658-2662, 2019 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-30942601

RESUMO

A photoinduced, phosphoranyl radical-mediated protocol for the direct N-O cleavage of strained cycloketone oximes via a polar/SET crossover process was developed for the first time. This visible-light-driven direct N-O activation mode for oxime offers beneficial features such as streamlined synthetic process and versatile photochemical reactivities. Consequently, the alkenes and α-trifluoromethyl alkenes with varied electronic and structural features acted as competent radical receptors in this protocol, enabling facile accesses to a range of elongated cyano and/or gem-difluoroalkene-bearing compounds.

16.
Org Lett ; 21(7): 2166-2170, 2019 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-30908056

RESUMO

A one-pot squaramide-catalyzed enantioselective ring-reorganization domino sequence (Michael addition/intramolecular ring-opening/lactamization) of 3-hydroxyoxindole and methyleneindolinone, which can be readily derived from 3-oxindole, has been established in this work. As a result, novel polycyclic quinolinone-spirooxindoles bearing three contiguous chiral centers were efficiently and step-economically assembled under mild conditions in high yields (up to 97%) with excellent enantioselectivities (up to >99% ee) and moderate to good diastereoselectivities (up to >95:5 dr).

17.
Chemistry ; 25(18): 4673-4677, 2019 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-30840339

RESUMO

One-pot ring-opening/ring-closure process of combining methyleneindolinone with 3-aminooxindole has been developed in this work. Novel polycyclic spirooxindoles were efficiently assembled under mild conditions in high yields (up to 95 %) with moderate to good diastereoselectivities (up to >95:5 d.r.) through simple filtration.

18.
Acta Trop ; 192: 87-90, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30738024

RESUMO

Hepatitis E virus (HEV) and influenza A virus (IAV) are two important pathogens which can infect humans and various animals causing public health problems. In this study, the seroprevalence and risk factors associated with HEV and IAV infection in farmed wild boars were investigated in China. A total of 758 serum samples were collected from farmed wild boars between 2015 and 2016, and antibodies against HEV and IAV were examined by enzyme-linked immunosorbent assay (ELISA) using commercially available kits. The overall prevalence of anti-HEV antibodies was 24.54% (186/758, 95% CI 21.48-27.60) in farmed wild boars. There were statistically significant differences in the HEV seroprevalence in farmed wild boars of different ages (<22 days: 8.33%; 22-66 days: 18.89%; >66 days: 26.36%) (P < 0.05) and different genders (50.00% in male and 23.49% in female) (P < 0.01). However, there was no statistically significant difference in the HEV seroprevalence in farmed wild boars of different regions and different years. The overall IAV seroprevalence was 5.80% (44/758, 95% CI 4.14-7.46), and there was no statistically significant difference in the IAV seroprevalence in farmed wild boars of different ages and genders, collected from different regions and different years. Our results indicate that HEV and IAV infections in farmed wild boars may pose a potential risk for human infection. To our knowledge, this is the first report of HEV and IAV seroprevalence in farmed wild boars in China, which provides baseline data for further studies and for control of HEV and IAV infection in farmed wild boars.


Assuntos
Animais Domésticos/virologia , Anticorpos Anti-Hepatite/sangue , Vírus da Hepatite E/imunologia , Vírus da Hepatite E/isolamento & purificação , Hepatite E/imunologia , Vírus da Influenza A/isolamento & purificação , Sus scrofa/virologia , Animais , China , Feminino , Hepatite E/epidemiologia , Humanos , Influenza Humana/epidemiologia , Masculino , Prevalência , Estudos Soroepidemiológicos , Suínos/virologia
19.
J Cell Mol Med ; 23(4): 2769-2781, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30729671

RESUMO

Periodontitis, an oral inflammatory disease caused by periodontal pathogen infection, is the most prevalent chronic inflammatory disease and a major burden on healthcare. The TAM receptor tyrosine kinases (Tyro3, Axl and Mertk) and their ligands (Gas6 and Pros1) play a pivotal role in the resolution of inflammation and have been associated with chronic inflammatory and autoimmune diseases. In this study, we evaluated the effects of exogenous Pros1 in in vitro and in vivo models of periodontitis. We detected higher Pros1 but lower Tyro3 levels in inflamed gingival specimens of periodontitis patients compared with healthy controls. Moreover, Pros1 was mostly localized in the gingival epithelium of all specimens. In cultured human gingival epithelial cells (hGECs), Porphyromonas gingivalis LPS (p.g-LPS) stimulation down-regulated Pros1 and Tyro3. Exogenous Pros1 inhibited p.g-LPS-induced production of TNF-α, IL-6, IL-1ß, MMP9/2 and RANKL in a Tyro3-dependent manner as revealed by PCR, Western blot analysis, ELISA and gelatin zymography. Pros1 also restored Tyro3 expression down-regulated by p.g-LPS in hGECs. In rats treated with ligature and p.g-LPS, administration of Pros1 attenuated periodontitis-associated gingival inflammation and alveolar bone loss. Our mechanistic studies implicated SOCS1/3 and STAT1/3 as mediators of the in vitro and in vivo anti-inflammatory effects of Pros1. Collectively, the findings from this work supported Pros1 as a novel anti-inflammatory therapy for periodontitis.

20.
Chem Commun (Camb) ; 55(18): 2712-2715, 2019 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-30758023

RESUMO

A visible-light-induced difluoroalkylation of N,N'-cyclicazomethine imine was successfully realized through a novel photoredox radical-radical cross-coupling reaction. This developed protocol exhibits high functional group tolerance and affords a variety of difluorinated 3-pyrazolidinone scaffolds. Extensive mechanistic investigations have been undertaken, well revealing the involvement of a reductive radical-radical coupling pathway.

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