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1.
Artigo em Inglês | MEDLINE | ID: mdl-32352282

RESUMO

Two-dimensional (2D) semiconductors have been a central focus for next-generation electronics and optoelectronics owing to their great potential to extend the scaling limits in a silicon transistor. However, due to the lack of surface dangling bonds in most 2D semiconductors, such as graphene and transition metal dichalcogenides (TMDs), the direct growth of the high-κ film on these 2D materials via an atomic layer deposition (ALD) technique often produces dielectrics with poor quality, which hinders their integration in the modern semiconductor industry. Here, we comprehensively investigate the ALD growth of the Al2O3 layer on 2D exfoliated black phosphorus (BP). Intriguingly, we found that the 2D BP with "silicon-like" characteristics possesses a native surface oxide layer PxOy after air exposure. The PxOy-induced surface dangling bonds enable the spontaneous integration of the high-quality Al2O3 layer on the BP flake without any pretreatments to functionalize the surface. Additionally, the Al2O3 layer could effectively passivate BP to prevent its degradation in ambient conditions, which addresses the most serious problem of the BP material. Moreover, the Al2O3-encapsulated BP field-effect transistor (FET) exhibits good electrical transport performance, with a high hole mobility of ∼420 cm2 V-1 s-1 and electron mobility of ∼80 cm2 V-1 s-1. Moreover, the high-quality Al2O3 layer can also be integrated into the top-gated BP transistor and inverter. Our findings reveal the silicon-like characteristics of BP for the high-κ ALD dielectric growth technology, which promises the seamless integration of 2D BP in the modern semiconductor industry.

2.
Mol Cell Probes ; : 101585, 2020 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-32376213

RESUMO

OBJECTIVE: Apoptosis is a prominent form of neuron death in cerebral ischemia-reperfusion-induced injury. Accompanied with the pathogenesis, Circ_002664 is upregulated. However, its role in the neuron apoptosis and the underlying mechanisms are unknown. METHODS: In this study, HT22 cells were treated with oxygen glucose deprivation and reoxygenation (OGD/R). The cell viability, apoptosis, proliferation and mitochondrial potential were examined. The expressions of interested genes, Circ_002664, miR-182-5p and Herpud1, were measured. The roles of these genes in OGD/R-induced cell injury were investigated by knockdown, overexpression alone or in combination. Additionally, the interactions between Circ_002664, miR-182-5p and Herpud1 were validated by luciferase report assay. The levels of MAP2, CHOP, Cytochrome C (CYC) and cleaved caspase-3 were determined. RESULTS: OGD/R treatment significantly increased cell apoptosis, decreased cell proliferation and mitochondrial potential, as well as increased Circ_002664 and Herpud1 expressions, and decreased miR-182-5p level. Circ_002664 knockdown markedly inhibited the effects by OGD/R on cell survival and altered expression of miR-182-5p and Herpud1. MiR-182-5p was observed sponged by Circ_002664 and negatively mediated its effect above mentioned, and this was by directly targeting Herpud1. Additionally, it was observed that CHOP expressions were regulated by Circ_002664/miR-182-5p/Herpud1 pathway, and in turn mediated its regulation in CYC and cleaved caspase-3. CONCLUSIONS: In summary, our data showed that the Circ_002664 importantly contributed to neuronal cell apoptosis induced by OGD/R treatment, and this might be achieved by directly targeting miR-182-5p/Herpud1 pathway.

3.
Nan Fang Yi Ke Da Xue Xue Bao ; 40(3): 361-369, 2020 Mar 30.
Artigo em Chinês | MEDLINE | ID: mdl-32376584

RESUMO

OBJECTIVE: To investigate the role of miR129 in mediating the effect of chloroquine to enhance cisplatin- induced apoptosis in nasopharyngeal carcinoma cells (HNE1). METHODS: MTT assay was used to detect the viability of HNE1 cells treated with different concentrations of cisplatin. Colony formation of HNE1 cells treated with cisplatin and chloroquine, alone or in combination, was observed using crystal violet staining. BALB/C unde mice were inoculated with HNE1 cells and randomly divided into 4 groups with 6 mice in each group. The mice received intraperitoneal injections of cisplatin and chloroquine, alone or in combination once every 3 days for 4 consecutive weeks, and the tumor growth was observed in each group. The expression of miR129 in HNE1 cells treated with chloroquine, cisplatin, or both was detected with qPCR. The effects of miR129 suppression with a miR129 inhibitor on the expressions of autophagy related proteins p62, LC3B, Beclin1 and the drug-resistant related protein P-glycoprotein (P-gp) were examined using Western blotting in HNE1 cells treated with chloroquine, cisplatin, or both; the changes in cell apoptosis were detected Annexin V/PI double staining. RESULTS: Chloroquine combined with cisplatin significantly inhibited HNE1 cell proliferation in vitro and the growth of HNE1 cell-derived tumor in nude mice as compared with cisplatin alone (P < 0.01). In cultured HNE1 cells, inhibition of the expression of miR129 significantly promoted autophagy and up-regulated P-gp expression (P < 0.01); Chloroquine obviously inhibited cisplatin-induced autophagy and up-regulated the expression of miR129 in HNE1 cells (P < 0.01). Transfection of the cells with the miR129 inhibitor abolished the inhibitory effect of chloroquine on cisplatin-induced autophagy, and significantly increased the cell survival rate (P < 0.05) and lower the cell apoptotic rate (P < 0.01) after combined treatment with chloroquine and cisplatin. CONCLUSIONS: Chloroquine enhances the pro-apoptotic effect of cisplatin by up-regulating miR129 to inhibit autophagy and drug resistance in HNE1 cells.

4.
Polymers (Basel) ; 12(5)2020 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-32357433

RESUMO

Although sulfonic acid (SA)-based proton-exchange membranes (PEMs) dominate fuel cell applications at low temperature, while sulfonation on polymers would strongly decay the mechanical stability limit the applicable at elevated temperatures due to the strong dependence of proton conduction of SA on water. For the purpose of bifunctionally improving mechanical property and high-temperature performance, Nafion membrane, which is a commercial SA-based PEM, is composited with fabricated silica nanofibers with a three-dimensional network structure via electrospinning by considering the excellent water retention capacity of silica. The proton conductivity of the silica nanofiber-Nafion composite membrane at 110 °C is therefore almost doubled compared with that of a pristine Nafion membrane, while the mechanical stability of the composite Nafion membrane is enhanced by 44%. As a result, the fuel cell performance of the silica nanofiber-Nafion composite membrane measured at high temperature and low humidity is improved by 38%.

5.
Environ Res ; 186: 109524, 2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32353787

RESUMO

Herein, a simple wireless charger which provided an alternative to conventional connection for delivering the electricity was employed to power the microbial electrolysis cell (MEC) for hydrogen recovery from organics. The coulombic efficiency of the wireless power transmission (WPT) was 75.37%, which was nearly similar to the average value of the conventional wired power transmission (CWPT) at the same experimental conditions (78.23%). The energy efficiency was 130.58%, it was clearly that the wireless charging (141.57%) slightly resulted in energy losing compared with conductive wire connection. The saving cost of WPT-driven MEC was a promising compensation to the energy loss according to the economic analysis of WPT, i.e., the WPT can be cost-beneficial once the distance between charger and reactor beyond a limited value. Overall, the feasibility of WPT suggests a straightforward way to construct large-scale MES with low cost and comparable performance.

6.
Artigo em Inglês | MEDLINE | ID: mdl-32223146

RESUMO

The energy dissipation issue has become one of the greatest challenges of the modern electronic industry. Incorporating graphene into the electronic devices has been widely accepted as a promising approach to solve this issue, due to its superior carrier mobility and thermal conductivity. Here, using Raman spectroscopy and infrared thermal microscopy, we identify the energy dissipation behavior of graphene device with different thicknesses. Surprisingly, the monolayer graphene device is demonstrated to have a comparable energy dissipation efficiency per unit volume with that of a few-layer graphene device. This has overturned the traditional understanding that the energy dissipation efficiency will reduce with the decrease of functional materials dimensions. Additionally, the energy dissipation speed of the monolayer graphene device is very fast, promising for devices with high operating frequency. Our finding provides a new insight into the energy dissipation issue of two-dimensional materials devices, which will have a global effect on the development of the electronic industry.

7.
Cell Death Dis ; 11(3): 206, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-32231199

RESUMO

Gastric cancer (GC) has a high mortality rate, and metastasis is the main reason for treatment failure. It is important to study the mechanism of tumour invasion and metastasis based on the regulation of key genes. In a previous study comparing the expression differences between GES-1 and SGC-7901 cells, PCDHGA9 was selected for further research. In vitro and in vivo experiments showed that PCDHGA9 inhibited invasion and metastasis. A cluster analysis suggested that PCDHGA9 inhibited epithelial-mesenchymal transition (EMT) through the Wnt/ß-catenin and TGF-ß pathways. Laser confocal techniques and western blotting revealed that PCDHGA9 inhibited the nuclear translocation of ß-catenin, regulated T cell factor (TCF)/ /lymphoid enhancer factor (LEF) transcriptional activity, directly impacted the signal transmission of the TGF-ß/Smad2/3 pathway, strengthened the adhesion complex, weakened the effects of TGF-ß, and blocked the activation of the Wnt pathway. In addition, PCDHGA9 expression was regulated by methylation, which was closely related to poor clinical prognosis. The aim of this study was to elucidate the molecular mechanism by which PCDHGA9 inhibits EMT and metastasis in GC to provide a new theoretical basis for identifying GC metastasis and a new target for improving the outcome of metastatic GC.

8.
Environ Res ; 183: 109145, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32035407

RESUMO

To investigate the influence of antibiotics on microbial interactions in a biofilm community, we set up eight replicate reactors of microbial electrolysis cell (MEC) and applied a broad-spectrum antibiotic florfenical (FLO) as an environmental disturbance. According to the results, exposure to FLO resulted in degradation of reactor performance. The MEC could also rebound back to the comparably stable state at a certain time which exhibited a great resilience ability in response to antibiotic disturbance. The FLO perturbation showed a significant influence on the electroactive biofilms (EABs) with a distinct reformation of the community structure. Network analysis revealed that microbial interactions in the biofilms after full recovery became much closer, with a rapid increase in the positive interactions between the predominant genus Geobacter and other microorganisms as compared to the stage before FLO disturbance. Moreover, the keystone species in the networks after full recovery possessed more connections between Geobacter and potential synergistic species. Our results demonstrated that FLO, with broad-spectrum antibacterial ability, could restructure the EABs with more positive interactions for hydrogen production. This study demonstrated the response mechanisms of the MECs to the antibiotic disturbance, providing a scientific reference for the rapid development of this biotechnology to treat wastewater containing antibiotics.

9.
Acta Cir Bras ; 34(12): e201901202, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32049183

RESUMO

PURPOSE: To explore the potential role and unclear molecular mechanisms of vaccarin in wound healing. METHODS: Rats' skin excision model to study the effects of vaccarin on wound healing in vivo . Hematoxylin and eosin staining was performed to evaluate Histopathologic characteristics. Immunohistochemistry was employed to assess the effects of vaccarin in accelerating angiogenesis. Western blot was used to evaluate relative protein expressed levels. RESULTS: Vaccarin could significantly promote wound healing and endothelial cells and fibroblasts proliferation in the wound site. Immunohistochemistry and Western blot studies showed that the nodal proteins and receptor (bFGFR) related to angiogenesis signaling pathway were activated, and the microvascular density in the wound site was markedly higher than that in the control group. CONCLUSIONS: The present study was the first to demonstrate that vaccarin is able to induce angiogenesis and accelerate wound healing in vivo by increasing expressions of p-Akt, p-Erk and p-bFGFR. This process is mediated by MAPK/ERK and PI3K/AKT signaling pathways.


Assuntos
Indutores da Angiogênese/farmacologia , Caryophyllaceae/química , Quinases de Proteína Quinase Ativadas por Mitógeno/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/efeitos dos fármacos , Extratos Vegetais/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Western Blotting , Proliferação de Células/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Imuno-Histoquímica , Masculino , Quinases de Proteína Quinase Ativadas por Mitógeno/análise , Fosfatidilinositol 3-Quinases/análise , Extratos Vegetais/química , Ratos Sprague-Dawley , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/análise , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/efeitos dos fármacos , Reprodutibilidade dos Testes , Transdução de Sinais , Fatores de Tempo
10.
Nano Lett ; 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32019309

RESUMO

Single-atom electrocatalysts (SAEs) can realize the target of low-cost by maximum atomic efficiency. However, they usually suffer performance decay due to high energy states, especially in a harsh acidic water splitting environment. Here, we conceive and realize a double protecting strategy that ensures robust acidic water splitting on Ir SAEs by dispersing Ir atoms in/onto Fe nanoparticles and embedding IrFe nanoparticles into nitrogen-doped carbon nanotubes (Ir-SA@Fe@NCNT). When Ir-SA@Fe@NCNT acts as a bifunctional electrocatalyst at ultralow Ir loading of 1.14 µg cm-2, the required overpotentials to deliver 10 mA cm-2 are 250 and 26 mV for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in 0.5 M H2SO4 electrolyte corresponding to 1370- and 61-fold better mass activities than benchmark IrO2 and Pt/C at an overpotential of 270 mV, respectively, resulting in only 1.51 V to drive overall water splitting. Moreover, remarkable stability is also observed compared to Pt/C-IrO2.

11.
Bioresour Technol ; 304: 122938, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32062393

RESUMO

Extracellular DNA (exDNA) can induce bias when evaluating the microbiota in wastewater treatment systems, particularly when cell lysis caused by thermal hydrolysis pretreatment (THP) releasing abundant DNA. However, the influence of such exDNA is still unknown. Accordingly, this study applied a pretreatment strategy for DNA extraction with proteinase K and DNase Ⅰ to minimize the influence of exDNA when evaluating the sludge microbiota. Lactobacillus and Peptostreptococcus were confirmed as the main THP-resistant microorganisms. Gram-positive bacteria were more resistant to THP, implying that the presence of a cell wall could promote THP resistance in bacteria. Moreover, the ability to form spores did not affect the resistance of bacteria to THP. These findings showed that resistant microbiota could be effectively evaluated by excluding exDNA, which can provide important insights into the understanding of microbiota dynamic and the effects of pretreatment on the precision of microbiota analysis in sludge.


Assuntos
Microbiota , Eliminação de Resíduos Líquidos , Anaerobiose , DNA , Hidrólise , Esgotos
12.
J Hazard Mater ; 386: 121966, 2020 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-31896006

RESUMO

On-line chemical cleaning with sodium hypochlorite (NaOCl) is widely employed for sustaining MBR permeability, during which the inevitable contact between activated sludge and NaOCl had been shown to trigger substantial release of dissolved organic matter (DOM). Therefore, this work further explored the formation mechanisms of such DOM by looking into the respective reactions of intracellular organic matter (IOM) and cell debris in activated sludge with NaOCl. The results showed that DOM was primarily produced from the dissolution of cell wall, while IOM release was insignificant at the NaOCl concentration of 25 mg/L as Cl2. On the basis of experimental observations, a three-step mechanism was proposed for elucidating the DOM formation from activated sludge upon NaOCl exposure: (i) NaOCl first damaged cells by perforating cellular wall, producing a considerable amount of humic-like substances and low-molecular-weight halogenated byproducts; (ii) IOM was released but rapidly degraded and humified by NaOCl, accompanied with the formation of relatively high-molecular-weight halogenated byproducts; (iii) the residual NaOCl and combined chlorine continued to react with cell wall or likely diffused into cells leading to the deactivation of DNA/enzymes. Consequently, this study offers mechanistic insights into the origination of emerging contaminants during on-line membrane cleaning of practical MBR.

13.
J Biosci Bioeng ; 129(2): 199-205, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31587942

RESUMO

The corrosive issues are comprehensively caused in oilfield rejection system, in which sulfide is one of (bio-)chemical factors leading to high corrosive rate and blocking problem. Generally, aerobic treatment is a well-established and cost-effective unit for sulfide removal before oilfield wastewater reinjection. However, the residual dissolved oxygen (DO), which causes chemical, biological and electrochemical corrosion to water injection pipeline equipment, is still high after multi-stage filtration of DO removal. Here, a novel system to achieve quick and efficient DO removal through a three-electrode (cathode-anode-cathode)-upflow bioelectrochemical reactor (RCAC) was constructed before wastewater reinjection. Bioelectrodes were well established by utilizing organic matters of oilfield wastewater and conducted extracellular electron transport to achieve a steady DO removal from ∼5 mg/L to 0.01 mg/L (HRT 6 h), the DO removal efficiency reached approximately 100%, and the downside biocathode made the largest contribution for DO removal. In the treated wastewater, the corrosion rate of stainless steel N80 ultimately declined over 30 days testing. As a result of DO removal and ammonia conversion to nitrate by bioelectrodes, the corrosive microorganisms were substantially changed. Especially, sulfate-reducing bacteria (SRB) on the surface of N80 immersed in treated wastewater were decreased in abundance; while nitrate-reducing bacteria (NRB) enriched more, which can compete with SRB to prevent biological corrosion.

14.
Chemosphere ; 245: 125484, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31864053

RESUMO

Wastewater from high-speed railway trains represents a mobile reservoir of microorganisms with antibiotic resistance. It harbors abundant and diverse antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs). This study investigated the removal of ARB and ARGs in a pilot-scale reactor, which consisted of an anaerobic/anoxic/oxic process, anaerobic/anoxic/aerobic process, and ozone-based disinfection to treat 1 m3/day wastewater from an electric multiple unit high-speed train. Further, the high prevalence of two mobile genetic elements (intI1 and Tn916/615) and five ARGs (tetA, tetG, qnrA, qnrS, blaNDM-1, and ermF) was investigated using quantitative PCR. Significant positive correlations between ARGs (tetA, blaNDM-1, and qnrA) and intI1 were identified (R2 of 0.94, 0.85, and 0.70, respectively, P < 0.01). Biological treatment could significantly reduce Tn916/1545 (2.57 logs reduction) and Enterococci (2.56 logs reduction of colony forming unit (CFU)/mL), but the qnrS abundance increased (1.19 logs increase). Ozonation disinfection could further significantly decrease ARGs and Enterococci in wastewater, with a reduction of 1.67-2.49 logs and 3.16 logs CFU/mL, respectively. Moreover, food-related bacteria families which may contain opportunistic or parasitic pathogens (e.g., Moraxellaceae, Carnobacteriaceae, and Ruminococcaceae) were detected frequently. Enterococci filtered in this study shows multi-antibiotic resistance. Our study highlights the significance to mitigate antibiotic resistance from wastewater generated from high-speed railway trains, as a mobile source.


Assuntos
Resistência Microbiana a Medicamentos/genética , Ferrovias , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/microbiologia , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Desinfecção , Genes Bacterianos/efeitos dos fármacos , Ozônio
15.
Sci Total Environ ; 706: 136063, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31855630

RESUMO

Effectiveness of N might be modified in rice cultivation under future climate change with elevated atmospheric CO2 concentration ([CO2]). At present, limited information is available to understand how plant N uptake and N use efficiency respond to elevated [CO2] and/or temperature in Chinese double rice cropping systems. A four-year field experiment was therefore conducted using open-top chambers with varying [CO2] (ambient, ambient +60 µmol mol-1) and varying temperature (ambient, ambient +2 °C) in Hubei Province, Central China. Compared with ambient conditions, elevated [CO2] increased plant N uptake and N use efficiency, as measured by fertilizer N recovery efficiency (NRE), N agronomic efficiency (NAE), N physiological efficiency (NPE) and apparent system N use efficiency (NUEsys), in both early rice and late rice. CO2 enrichment tended to decrease soil mineral N concentration since more N was assimilated by plants. Elevated temperature led to lower plant N uptake and decreased NRE and NAE in early rice, due to a reduction in grain yield induced by heat injury. In contrast, warming increased plant N uptake and N use efficiency in late rice as no heat stress existed. Warming tended to increase soil mineral N concentration in early rice but had negligible effects in late rice. When elevated [CO2] and temperature were combined, the positive effects of CO2 enrichment for N utilization were able to compensate for the negative effects of warming in early rice, while the interaction was synergetic in late rice. Hence, co-elevation of [CO2] and temperature led to higher N use efficiency (64.6% for NUEsys across four years) and decreased annual N surplus by 28.6-36.5 kg N ha-1 compared with ambient conditions. Our findings confirm that CO2 enrichment and air warming can improve N use efficiency at both crop level and system level in Chinese double rice cultivation.


Assuntos
Oryza , Dióxido de Carbono , China , Solo , Temperatura
16.
Genes (Basel) ; 11(1)2019 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-31877985

RESUMO

MicroRNAs (miRNAs) are short noncoding RNA molecules that regulate gene expression at the posttranscriptional level. Reverse transcription-quantitative PCR (RT-qPCR) is one of the most common methods used for quantification of miRNA expression, and the levels of expression are normalized by comparing with reference genes. Thus, the selection of reference genes is critically important for accurate quantification. The present study was intended to identify appropriate miRNA reference genes for normalizing the level of miRNA expression in Citrus sinensis L. Osbeck and Citrus reticulata Blanco infected by Xanthomonas citri subsp. citri, which caused citrus canker disease. Five algorithms (Delta Ct, geNorm, NormFinder, BestKeeper and RefFinder) were used for screening reference genes, and two quantification approaches, poly(A) extension RT-qPCR and stem-loop RT-qPCR, were used to determine the most appropriate method for detecting expression patterns of miRNA. An overall comprehensive ranking output derived from the multi-algorithms showed that poly(A)-tailed miR162-3p/miR472 were the best reference gene combination for miRNA RT-qPCR normalization in citrus canker research. Candidate reference gene expression profiles determined by poly(A) RT-qPCR were more consistent in the two citrus species. To the best of our knowledge, this is the first systematic comparison of two miRNA quantification methods for evaluating reference genes. These results highlight the importance of rigorously assessing candidate reference genes and clarify some contradictory results in miRNA research on citrus.

17.
Int J Mol Sci ; 20(23)2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31775391

RESUMO

: Tea (Camellia sinensis) is enriched with bioactive secondary metabolites, and is one of the most popular nonalcoholic beverages globally. Two tea reference genomes have been reported; however, the functional analysis of tea genes has lagged, mainly due to tea's recalcitrance to genetic transformation and the absence of alternative high throughput heterologous expression systems. A full-length cDNA collection with a streamlined cloning system is needed in this economically important woody crop species. RNAs were isolated from nine different vegetative tea tissues, pooled, then used to construct a normalized full-length cDNA library. The titer of unamplified and amplified cDNA library was 6.89 × 106 and 1.8 × 1010 cfu/mL, respectively; the library recombinant rate was 87.2%. Preliminary characterization demonstrated that this collection can complement existing tea reference genomes and facilitate rare gene discovery. In addition, to streamline tea cDNA cloning and functional analysis, a binary vector (pBIG2113SF) was reengineered, seven tea cDNAs isolated from this library were successfully cloned into this vector, then transformed into Arabidopsis. One FL-cDNA, which encodes a putative P1B-type ATPase 5 (CsHMA5), was characterized further as a proof of concept. We demonstrated that overexpression of CsHMA5 in Arabidopsis resulted in copper hyposensitivity. Thus, our data demonstrated that this represents an efficient system for rare gene discovery and functional characterization of tea genes. The integration of a tea FL-cDNA collection with efficient cloning and a heterologous expression system would facilitate functional annotation and characterization of tea genes.

18.
Molecules ; 24(22)2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31703459

RESUMO

This study describes the chemical constituents of Albiziae Cortex and their ability to ameliorate steatosis and promote proliferation and anti-oxidation in vitro. Together, five known lignan glycosides, (7S,8R)-erythro-syringylglycerol-ß-O-4'-sinapyl ether 9-O-ß-D-glucopyranoside (1), (+)-lyoniresinol-9'-O-gluco-side (2), (-)-lyoniresinol-9'-O-glucoside (3), picraquassioside C (4), and icariside E5 (5), were isolated from the Albiziae Cortex. Their structures were elucidated by extensive NMR and high-resolution mass spectrometry analysis and compared with reported data. Oil Red O staining results revealed that compounds 1, 2, and 3 attenuated lipid accumulation and lipid metabolic disorders in FFAs (oleate/palmitate, 2:1 ratio, 0.3 mM)-exposed HepG2 cells. The Cell Counting Kit 8 (CCK-8) assay results revealed that compounds 1 and 5 can significantly promote human umbilical vein endothelial cell (HUVEC) proliferation; meanwhile, these compounds did not exhibit significant cytotoxicity against HUVECs. In addition, 2',7'-dichlorofluorescein diacetate (DCFH-DA) staining results revealed that high glucose (HG)-induced reactive oxygen species (ROS) production was abolished by compounds 1, 2, and 3. This is the first report of the isolation of lignan skeletons from the genus Albizzia julibrissin with the ability to ameliorate steatosis and promote proliferation and anti-oxidation activities.

19.
Opt Lett ; 44(19): 4793-4796, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31568444

RESUMO

Computed tomography of chemiluminescence (CTC) is one kind of volumetric tomography which can recover 3D flame structures and has found extensive applications for spatiotemporally resolved measurements of flames. However, the existing CTC techniques rely on the pinhole model and fail when the flames are confined within a cylindrical glass due to image distortion caused by the refraction on both the internal and external surfaces of the glass. In this work, a refined camera model was developed by combining the pinhole camera model with Snell's laws using a reverse ray-tracing method to incorporate the effects of refraction. A proof-of-concept demonstration of CTC based on the refined camera model was conducted on a swirl flame confined within a 20-mm-thick K9 glass. The results proved the superiority of such technique against the existing version in terms of reconstruction accuracy. This work is expected to be especially useful for the study of combustion phenomena such as combustion instability for which the flames are typically confined within cylindrical combustors.

20.
Int J Mol Sci ; 20(18)2019 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-31533227

RESUMO

Cardiovascular complications are a major leading cause of mortality in patients suffering from type 2 diabetes mellitus (T2DM). Vascular endothelial dysfunction is a core pathophysiological event in the early stage of T2DM and eventually leads to cardiovascular disease. Vaccarin (VAC), an active flavonoid glycoside extracted from vaccariae semen, exhibits extensive biological activities including vascular endothelial cell protection effects. However, little is known about whether VAC is involved in endothelial dysfunction regulation under high glucose (HG) or hyperglycemia conditions. Here, in an in vivo study, we found that VAC attenuated increased blood glucose, increased glucose and insulin tolerance, relieved the disorder of lipid metabolism and oxidative stress, and improved endothelium-dependent vasorelaxation in STZ/HFD-induced T2DM mice. Furthermore, in cultured human microvascular endothelial cell-1 (HMEC-1) cells, we showed that pretreatment with VAC dose-dependently increased nitric oxide (NO) generation and the phosphorylation of eNOS under HG conditions. Mechanistically, VAC-treated HMEC-1 cells exhibited higher AMPK phosphorylation, which was attenuated by HG stimulation. Moreover, HG-triggered miRNA-34a upregulation was inhibited by VAC pretreatment, which is in accordance with pretreatment with AMPK inhibitor compound C (CC). In addition, both reactive oxygen species (ROS) scavenger N-acetyl-L-cysteine (NAC) and VAC abolished HG-evoked dephosphorylation of AMPK and eNOS, increased miRNA-34a expression, and decreased NO production. These results suggest that VAC impedes HG-induced endothelial dysfunction via inhibition of the ROS/AMPK/miRNA-34a/eNOS signaling cascade.


Assuntos
Angiopatias Diabéticas/metabolismo , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Glicosídeos/farmacologia , Substâncias Protetoras/farmacologia , Animais , Diabetes Mellitus Tipo 2/metabolismo , Angiopatias Diabéticas/tratamento farmacológico , Angiopatias Diabéticas/etiologia , Angiopatias Diabéticas/patologia , Modelos Animais de Doenças , Glicosídeos/química , Células Endoteliais da Veia Umbilical Humana , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Camundongos , MicroRNAs , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fosforilação , Substâncias Protetoras/química , Espécies Reativas de Oxigênio/metabolismo
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