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1.
J Nanosci Nanotechnol ; 20(2): 1140-1147, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383114

RESUMO

The fabrication of bimetallic catalysts has been taken great focus in the concept of heterogeneous catalysis due to their high efficiency and economic concerns. In this work, a series of bimetallic Ru-Re catalysts were designed and synthesized for the selective hydrogenation of dimethyl terephthalate (DMT) to 1,4-cyclohexane dicarboxylate (DMCD) under mild condition. Characterization techniques including the XRD, TEM, STEM-HAADF EDX elemental mapping, H2-TPR, and XPS were used to study the surface chemical property, the morphology, as well as the catalytic behavior of different samples. It was revealed that the monometallic Ru catalyst already has the capacity to activate and transform DMT into DMCD. Whilst the promotion effect can be optimized to a maximum with only small amount of Re, with the mass ratio of Ru/Re as 10:1. It was also revealed that the addition of Re could largely enhance the distribution of surface active metal species, facilitate the charge transfer between Ru and Re, as well as strengthen the Ru-Re synergistic interaction, which further led to the modification of the redox ability and the catalytic performances of samples. However, excessive addition of Re caused strong interaction between Ru and Re, and further limited the H2 activation and the seasonable release of the active reducible metal species, which was responsible for the depressed catalytic performances in the presence of higher Re loading. The Ru1.25Re0.13/AC catalyst displayed the DMT conversion of 82% with DMCD selectivity of 96% under mild condition of 70 °C at 3 MPa. The specific rate of Ru1.25Re0.13/AC based on per gram of Ru was 0.44 mol·g-1 Ru·h-1.

2.
J Nanosci Nanotechnol ; 20(2): 1215-1223, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383121

RESUMO

Designing a highly active, stable and cost-effective electrocatalyst with multiple functionalities toward hydrogen evolution and oxygen reduction applications is crucial for the development of renewable energy sources. Here, the synthesis of hollow PtNi nanostrings via a facile two-step template method is reported. The PtNi nanostrings own Pt-rich rough surfaces, and hollow string-like structure with the structural disorder morphology. Impressively, the unique hollow PtNi nanostrings exhibit excellent electrocatalytic activity toward the hydrogen evolution and oxygen reduction reactions. The obtained overpotential is only 44.60 mV at current density of 10 mA cm-2 for hydrogen evolution reaction. Furthermore, the hollow PtNi nanostrings exhibit a high mass activity of 2.5 A mg-1Pt and a superior specific activity of 3.89 mA cm-2 at 0.90 V versus reversible hydrogen electrode in oxygen reduction reaction, respectively, which are 10 and 9 times higher than those of the commercial Pt/C. This work provides a promising approach for the synthesis of highly bifunctional electrocatalysts with a hollow sting-like structure to promote their application in the hydrogen evolution and oxygen reduction reactions.

3.
Appl Opt ; 58(27): 7311-7318, 2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31674375

RESUMO

Precision glass molding (PGM) has become a viable processing method for large-volume aspheric optical elements. The optimization of a PGM process is an obstacle to the realization of mass production. The current work is focused on optimizing the process parameters to gain satisfactory surface shape. But the machining cycle time is not optimized. When setting the process route in the machine interface, going to the next step after reaching the target temperature rather than reaching the target time is usually set for the heating and cooling phase. Thus, the time to complete the heating and cooling stages of the production cycle is known only in the actual production. As for chalcogenide glass, its physical and chemical properties are greatly dependent on temperature. So, it is necessary to effectively simulate these stages to obtain the cost in time for actual production. Due to the excellent availability of numerical simulation, the rapid development of computing technology, and the increase of task scale in data and information processing, the finite element method can be applied to simulate the whole molding process. In this paper, a heat transfer model is established with the partial differential equation toolbox in MATLAB software. MSC.Marc software is used to simulate the heating stage at the same time. The numerical results are consistent, indicating that the heat transfer model established in MATLAB is, at least to a certain extent, valid. The heat transfer model needs further improvement by considering temperature-dependent properties such as viscoelasticity to make it a more effective tool for process analysis and optimization.

4.
Sci Rep ; 9(1): 15192, 2019 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-31645637

RESUMO

Previous research has shown that genes play a substantial role in determining a person's susceptibility to age-related hearing impairment. The existing studies on this subject have different results, which may be caused by difficulties in determining the phenotype or the limited number of participants involved. Here, we have gathered the largest sample to date (discovery n = 9,675; replication n = 10,963; validation n = 356,141), and examined phenotypes that represented low/mid and high frequency hearing loss on the pure tone audiogram. We identified 7 loci that were either replicated and/or validated, of which 5 loci are novel in hearing. Especially the ILDR1 gene is a high profile candidate, as it contains our top SNP, is a known hearing loss gene, has been linked to age-related hearing impairment before, and in addition is preferentially expressed within hair cells of the inner ear. By verifying all previously published SNPs, we can present a paper that combines all new and existing findings to date, giving a complete overview of the genetic architecture of age-related hearing impairment. This is of importance as age-related hearing impairment is highly prevalent in our ageing society and represents a large socio-economic burden.

5.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 36(10): 989-992, 2019 Oct 10.
Artigo em Chinês | MEDLINE | ID: mdl-31598942

RESUMO

OBJECTIVE: To explore the nature and origin of chromosomal copy number variants (CNVs) in a pedigree affected with mental retardation. METHODS: Genomic CNVs of the proband were analyzed by next generation sequencing (NGS). Chromosomal karyotypes of the proband and his relatives were analyzed with high-resolution karyotyping and fluorescence in situ hybridization (FISH). RESULTS: Clinical phenotypes of the proband and other patients from the pedigree included mental retardation and mild dysmorphism. The results of NGS revealed that the proband carried a 16.24 Mb microduplication at 4p16.3-15.32 and a 2.2 Mb microdeletion at 8p23.3-23.2. Other patients of the pedigree harbored the same variants, while those without the phenotypes did not harbor the variants. The results of high-resolution karyotyping and FISH revealed that the mother of the proband carried a reciprocal translocation between 4p and 8p, and her karyotype was 46,XX,t(4;8)(p16;p23). No karyotypic abnormality was detected in his father. CONCLUSION: The abnormal phenotypes of this pedigree may be attributed to 4p microduplication in conjunct with 8p microdeletion derived from a maternal balanced translocation between 4p and 8p.


Assuntos
Aberrações Cromossômicas , Duplicação Cromossômica , Testes Genéticos , Deficiência Intelectual/genética , Cromossomos Humanos Par 4 , Cromossomos Humanos Par 8 , Feminino , Humanos , Hibridização in Situ Fluorescente , Cariotipagem , Linhagem , Fenótipo
6.
Nat Prod Res ; : 1-7, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31638430

RESUMO

Two new triterpene saponins, namely notoginsenoside Ng5 (1) and notoginsenoside Ng6 (2) were isolated from the leaves of Panax notoginseng, along with five known ones. Their structures were determined by chemical methods, NMR and X-ray experiments. The absolute configuration of compound 3 with four sugar units was confirmed by single crystal X-ray analysis. Compounds 2-4 and 6 inhibited PC12 cell damage induced by serum deprivation, and increased cell viability from 58.7 ± 6.7% to 66.7 ± 4.5%, 76.1 ± 6.1%, 64.7 ± 5.2% and 67.2 ± 5.0% at 10 µM, respectively.

7.
ACS Sens ; 4(10): 2809-2818, 2019 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-31566369

RESUMO

E-textiles are gaining growing popularity recently due to low cost, light weight, and conformable compatibility with clothes in wearable and portable smart electronics. Here, an easy-handing, low cost, and scalable fabricating strategy is reported to fabricate conductive, highly flexible, and mechanically stretchable/twisted fiber gas sensor with great wearability and knittability. The proposed gas sensor is built using commercially available cotton/elastic threads as flexible/stretchable templates and reduced graphene oxide/mesoporous zinc oxide nanosheets as sensing layers to form conducting fibers. The as-prepared fiber demonstrates sensitive sensing response, excellent long-term stability (84 days), low theoretical detection limit (43.5 ppb NO2), great mechanical deformation tolerance (3000 bending cycles, 1000 twisting cycles and 65% strain strength), and washing durability in room-temperature gas detection. More significantly, scalable wearable characteristics including repairability, reliability, stability, and practicability have been efficiently improved, which are achieved by knotting the fractured fibers, incorporating multiple sensors in series/parallel and weaving multisensor array networks integrated into clothes. The good sensing properties, superior flexibility, and scalable applications of wearable fibers may provide a broad window for widespread monitoring of numerous human activities in personal mobile electronics and human-machine interactions.

8.
Clin Lab ; 65(10)2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31625369

RESUMO

BACKGROUND: Our multicenter clinical trial study for stage 4 chronic kidney disease (CKD) populations was conducted at 21 centers in China during the period 2011 to 2016. The CKD definition is based on glomerular filtration rate (GFR) values which can be estimated by creatinine-based predictive formulas. The validity and reliability of GFR estimation is thus largely dependent on the accurate and precise serum creatinine (SCr) measurements. As an integral part of this multicenter study, it is important to ensure the precision, accuracy, and center-to-center comparability of the SCr results. METHODS: Prior to initiating the study, we unified the measurement method of SCr determination as an enzymatic method and standardized the procedure in all of the laboratories. Then, the analytical performance of each analyzer at each laboratory was evaluated, including precision, accuracy, and comparability. RESULTS: All within-run and total CVs of the low and high level internal quality control (IQC) were comprised between 0.2% and 4.1% (< 1/3 CLIA'88). Total error of the IQC fall within the maximum 12% at all centers. The analytical bias against the Standard Reference material 967a target was less than ± 0.5% at Central Laboratory, indicating good accuracy. Correlation between the analyzers and the reference method were very high (r > 0.99). Passing-Bablok regression showed no significant deviation from linearity (p > 0.05). Bland-Altman analysis also showed good agreement (≥ 95% of results fell within the 95% limits of agreement). CONCLUSIONS: Performance evaluation helped in addressing preanalytical variations in measurement and gave op-timal quality assurance of laboratory measurement in the context of a multicenter clinical trial study.

9.
Appl Opt ; 58(26): 7121-7126, 2019 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-31503983

RESUMO

This work explores the variable curvature mirror's (VCM) elastic bending rules through modeling it as a thin elastic plate with an exponential thickness distribution actuated with a uniform pressure under simply supported boundary conditions. By using the small-parameter method, the general analytical expression of a plate's deflection is worked out. The results calculated by the analytical solution are compared to the finite element analysis of a VCM model with the same specific parameters. We demonstrate that the two have a good correlation with the each other. This analytical solution is an effective way to predict a VCM's deflection.

10.
Artigo em Inglês | MEDLINE | ID: mdl-31484371

RESUMO

A novel graphite-phase carbon nitride (g-C3N4)/bismuth ferrite (BiFeO3)/carbon nanotubes (CNTs) ternary magnetic composite (CNBT) was prepared by a hydrothermal synthesis. Using this material, Cr(VI) and methylene blue (MB) were removed from wastewater through synergistic adsorption and photocatalysis. The effects of pH, time, and pollutant concentration on the photocatalytic performance of CNBT, as well as possible interactions between Cr(VI) and MB species were analyzed. The obtained results showed that CNTs could effectively reduce the recombination rate of electron-hole pairs during the photocatalytic reaction of the g-C3N4/BiFeO3 composite, thereby improving its photocatalytic performance, while the presence of MB increased the reduction rate of Cr(VI). After 5 h of the simultaneous adsorption and photocatalysis by CNBT, the removal rates of Cr(VI) and MB were 93% and 98%, respectively. This study provides a new theoretical basis and technical guidance for the combined application of photocatalysis and adsorption in the treatment of wastewaters containing mixed pollutants.

11.
J Am Chem Soc ; 141(40): 15773-15778, 2019 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-31545036

RESUMO

A new strategy was developed for the asymmetric total synthesis of (-)-vinigrol. The strategy involved a linear sequence of 15 steps from 3-methyl-butanal (14 steps from chloro-dihydrocarvone) and did not need protecting groups. The synthetically challenging 1,5-butanodecahydronaphthalene core was constructed efficiently via a type II intramolecular [5+2] cycloaddition, followed by a unique ring-contraction cascade.

12.
Int J Biol Sci ; 15(9): 1787-1801, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31523183

RESUMO

Tandem mass spectrometry (MS/MS)-based de novo peptide sequencing is a powerful method for high-throughput protein analysis. However, the explosively increasing size of MS/MS spectra dataset inevitably and exponentially raises the computational demand of existing de novo peptide sequencing methods, which is an issue urgently to be solved in computational biology. This paper introduces an efficient tool based on SW26010 many-core processor, namely SWPepNovo, to process the large-scale peptide MS/MS spectra using a parallel peptide spectrum matches (PSMs) algorithm. Our design employs a two-level parallelization mechanism: (1) the task-level parallelism between MPEs using MPI based on a data transformation method and a dynamic feedback task scheduling algorithm, (2) the thread-level parallelism across CPEs using asynchronous task transfer and multithreading. Moreover, three optimization strategies, including vectorization, double buffering and memory access optimizations, have been employed to overcome both the compute-bound and the memory-bound bottlenecks in the parallel PSMs algorithm. The results of experiments conducted on multiple spectra datasets demonstrate the performance of SWPepNovo against three state-of-the-art tools for peptide sequencing, including PepNovo+, PEAKS and DeepNovo-DIA. The SWPepNovo also shows high scalability in experiments on extremely large datasets sized up to 11.22 GB. The software and the parameter settings are available at https://github.com/ChuangLi99/SWPepNovo.

13.
J Vis Exp ; (150)2019 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-31475992

RESUMO

We herein present a method for the synthesis of HNbWO6, HNbMoO6, HTaWO6 solid acid nanosheet modified Pt/CNTs. By varying the weight of various solid acid nanosheets, a series of Pt/xHMNO6/CNTs with different solid acid compositions (x = 5, 20 wt%; M = Nb, Ta; N = Mo, W) have been prepared by carbon nanotube pretreatment, protonic exchange, solid acid exfoliation, aggregation and finally Pt particles impregnation. The Pt/xHMNO6/CNTs are characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and NH3-temperature programmed desorption. The study revealed that HNbWO6 nanosheets were attached on CNTs, with some edges of the nanosheets being bent in shape. The acid strength of the supported Pt catalysts increases in the following order: Pt/CNTs < Pt/5HNbWO6/CNTs < Pt/20HNbMoO6/CNTs < Pt/20HNbWO6/CNTs < Pt/20HTaWO6/CNTs. In addition, the catalytic hydroconversion of lignin-derived model compound: diphenyl ether using the synthesized Pt/20HNbWO6 catalyst has been investigated.

14.
Cell Biol Int ; 2019 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-31393045

RESUMO

Cardamonin (CD), a naturally occurring chalcone isolated from large black cardamom, was previously reported to suppress the proliferation of breast cancer cells. However, its precise molecular anti-tumor mechanisms have not been well elucidated. In this study, we found that CD markedly inhibited the proliferation of MDA-MB 231 and MCF-7 breast cancer cells through the induction of G2/M arrest and apoptosis. Reactive oxygen species (ROS) plays a pivotal role in the inhibition of CD-induced cell proliferation. Treatment with N-acetyl-cysteine (NAC), an ROS scavenger, blocked CD-induced G2/M arrest and apoptosis in this study. Quenching of ROS by overexpression of catalase also blocked CD-induced cell cycle arrest and apoptosis. We showed that CD enhanced the expression and nuclear translocation of Forkhead box O3 (FOXO3a) via upstream c-Jun N-terminal kinase, inducing the expression of FOXO3a and its target genes, including p21, p27, and Bim. This process led to the reduction of cyclin D1 and enhancement of activated caspase-3 expression. The addition of NAC markedly reversed these effects, knockdown of FOXO3a using small interfering RNA also decreased CD-induced G2/M arrest and apoptosis. In vivo, CD efficiently suppressed the growth of MDA-MB 231 breast cancer xenograft tumors. Taken together, our data provide a molecular mechanistic rationale for CD-induced cell cycle arrest and apoptosis in breast cancer cells.

15.
BMC Bioinformatics ; 20(1): 397, 2019 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-31315562

RESUMO

BACKGROUND: Tandem mass spectrometry (MS/MS)-based database searching is a widely acknowledged and widely used method for peptide identification in shotgun proteomics. However, due to the rapid growth of spectra data produced by advanced mass spectrometry and the greatly increased number of modified and digested peptides identified in recent years, the current methods for peptide database searching cannot rapidly and thoroughly process large MS/MS spectra datasets. A breakthrough in efficient database search algorithms is crucial for peptide identification in computational proteomics. RESULTS: This paper presents MCtandem, an efficient tool for large-scale peptide identification on Intel Many Integrated Core (MIC) architecture. To support big data processing capability, a novel parallel match scoring algorithm, named MIC-SDP (spectrum dot product), and its two-level parallelization are presented in MCtandem's design. In addition, a series of optimization strategies on both the host CPU side and the MIC side, which includes pre-fetching, optimized communication overlapping scheme, multithreading and hyper-threading, are exploited to improve the execution performance. CONCLUSIONS: For fair comparisons, we first set up experiments and verified the 28 fold times speedup on a single MIC against the original CPU-based implementation. We then execute the MCtandem for a very large dataset on an MIC cluster (a component of the Tianhe-2 supercomputer) and achieved much higher scalability than in a benchmark MapReduce-based programs, MR-Tandem. MCtandem is an open-source software tool implemented in C++. The source code and the parameter settings are available at https://github.com/LogicZY/MCtandem .


Assuntos
Peptídeos/química , Software , Espectrometria de Massas em Tandem , Algoritmos , Bases de Dados de Proteínas , Humanos , Proteômica/métodos
16.
DNA Cell Biol ; 38(8): 796-807, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31295012

RESUMO

Myocardial hypertrophy is an important cause of heart failure and sudden death. Studies have shown that Mitofusin-2 (MFN2) is downregulated in myocardial hypertrophy, but the upstream regulation mechanism underlying its downexpression in cardiomyocytes is still unclear. This study aims to identify the expression profile of microRNAs (miRNAs) in hypertrophic cardiomyopathy (HCM) and explore the function of miRNA-20 in inducing cardiomyocyte hypertrophy through regulating MFN2. Through miRNA + mRNA microarray analysis, 1451 miRNAs were identified, 367 miRNAs expressed differently between groups. Meanwhile, a number of 24,718 mRNAs were identified, among which 5850 mRNAs were upregulated and 3005 mRNAs were downregulated in HCM group compared with the control group. Expression of hsa-miRNA-20a-5p was 2.26 times higher in the HCM group compared with the control group and 7 target gene prediction programs predicted MFN2 as a target of miRNA-20. In vitro model of hypertrophic cardiomyocytes displayed high expression level of miRNA-20, atrial natriuretic peptide (ANP) mRNA, and protein, accompanying low expression level of Mfn2 mRNA and protein, which meant miRNA-20 played a role in cardiomyocyte hypertrophy and might interact with MFN2 to function. Thereafter, overexpression of miRNA-20 led to cell hypertrophy accompanied with lowly expressed Mfn2 mRNA and protein. When transfected with miRNA-20 inhibitors, the expression of miRNA-20 and ANP gene was attenuated and MFN2 was the other way around. The cell surface area of Ang II group and mimic group was significantly larger compared with the control group, and in the inhibitor+Ang II group, the area was significantly decreased compared with the Ang II group. Dual-luciferase assays showed that miRNA-20 bound to 3' untranslated region of MFN2 and inhibited its expression. In conclusion, hypertrophic myocardium and normal myocardium have different miRNA expression profiles and the effect of miRNA-20 reducing the expression of MFN2 plays a role in promoting cardiomyocyte hypertrophy.


Assuntos
Cardiomiopatia Hipertrófica/genética , GTP Fosfo-Hidrolases/genética , MicroRNAs/genética , Proteínas Mitocondriais/genética , Miócitos Cardíacos/patologia , Regiões 3' não Traduzidas , Adulto , Angiotensina II/farmacologia , Animais , Estudos de Casos e Controles , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , Proteínas de Membrana/genética , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Miócitos Cardíacos/efeitos dos fármacos , Ratos Wistar
17.
Int J Med Sci ; 16(6): 793-799, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31337952

RESUMO

Background: Essential hypertension (EH) is a chronic disease of universal high prevalence and a well-established independent risk factor for cardiovascular and cerebrovascular events. The regulation of blood pressure is crucial for improving life quality and prognoses in patients with EH. Therefore, it is of important clinical significance to develop prediction models to recognize individuals with high risk for EH. Methods: In total, 965 subjects were recruited. Clinical parameters and genetic information, namely EH related SNPs were collected for each individual. Traditional statistic methods such as t-test, chi-square test and multi-variable logistic regression were applied to analyze baseline information. A machine learning method, mainly support vector machine (SVM), was adopted for the development of the present prediction models for EH. Results: Two models were constructed for prediction of systolic blood pressure (SBP) and diastolic blood pressure (DBP), respectively. The model for SBP consists of 6 environmental factors (age, BMI, waist circumference, exercise [times per week], parental history of hypertension [either or both]) and 1 SNP (rs7305099); model for DBP consists of 6 environmental factors (weight, drinking, exercise [times per week], TG, parental history of hypertension [either and both]) and 3 SNPs (rs5193, rs7305099, rs3889728). AUC are 0.673 and 0.817 for SBP and DBP model, respectively. Conclusions: The present study identified environmental and genetic risk factors for EH in northern Han Chinese population and constructed prediction models for SBP and DBP.

18.
Fitoterapia ; 137: 104262, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31284018

RESUMO

Eight undescribed 9,19-cycloartane type triterpenoid glycosides (cimdalglnoside A-H) and ten known analogues were obtained from the phytochemical research on the roots of Actaea dahurica (syn. Cimicifuga dahurica). All compounds were characterised by spectroscopic experiments, and chemical method. All the compounds isolated were assayed for cytotoxicity to five human cancer cell lines. Cimdalglnoside G showed promising cytotoxicities against Hela, and MCF-7 cell lines with IC50 values at 7.7 and 12.2 µM.


Assuntos
Actaea/química , Glicosídeos/farmacologia , Raízes de Plantas/química , Triterpenos/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , China , Glicosídeos/isolamento & purificação , Células HeLa , Humanos , Células MCF-7 , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Triterpenos/isolamento & purificação
19.
Fitoterapia ; 137: 104185, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31150768

RESUMO

Six new and one known dihydroagarofuran sesquiterpenoids esterified with organic acids were obtained from the leaves of Tripterygium wilfordii. Spectroscopic techniques (UV, IR, MS, NMR, ORD and CD) were used for the structure elucidation of the compounds. The structures of compounds 1 and 2 were confirmed by X-ray single crystallographic analyses. The inhibitory effects on NO production in LPS-induced macrophages of 1-7 were conducted. At 10 µmol/L, compounds 1, 2 and 7 showed moderate inhibitory effects on NO production in LPS-induced macrophages with inhibitory rate at 31.2 ±â€¯3.6, 40.9 ±â€¯4.3, and 66.79 ±â€¯3.1%, respectively.


Assuntos
Macrófagos/efeitos dos fármacos , Sesquiterpenos/farmacologia , Tripterygium/química , Animais , Camundongos , Estrutura Molecular , Óxido Nítrico/metabolismo , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Folhas de Planta/química , Células RAW 264.7 , Sesquiterpenos/isolamento & purificação
20.
Plant Physiol Biochem ; 141: 164-171, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31170640

RESUMO

For a comprehensive understanding of gene expression, enzyme activity and sugar concentrations in response to short-term water deficit in apple (Greensleeves), sugar-modulated gene expression and enzyme activities were analyzed. Water stress resulted in the accumulation of sorbitol, glucose, fructose, galactose and starch, accompanied by a significant reduction in photosynthesis and sucrose concentration. In response to short-term water deficits, the activities of aldose-6-phosphate reductase (A6PR; EC 1.1.1.200), sorbitol dehydrogenase (SDH; EC 1.1.1.14), neutral invertase (NINV; EC 3.2.1.26), sucrose synthase (SUSY; EC 2.4.1.13), and fructokinase (FK; EC 2.7.1.4) were higher, whereas cell wall invertase (CWINV; EC 3.2.1.26) and hexokinase (HK; EC 2.7.1.1) activities were lower. In addition, sucrose phosphate synthase (SPS; EC 2.4.1.14) activity increased during the initial stages of dehydration and then decreased as the drought strengthened. Transcript levels of MdA6PR, MdSDH1/2, MdNINV1/2, MdSUSY3, MdFK1/2/4, MdSOT1/2, MdSUC1-3, MdTMT2/3, MdvGT1, MdpGlcT1-4 were upregulated, whereas transcript levels of MdCWINV1/2, MdHK1/2/3/5, and MdTMT1 were downregulated after 6 days of water stress. These findings suggest that the sorbitol metabolism pathway is induced and high levels of hexose derived from photosynthetic products are transported into vacuoles for adjustment to the water deficit. Our results provide insights into the relationships between sugar levels and sugar-modulated gene and enzyme activity in response to the imposition of short-term water stress.


Assuntos
Metabolismo dos Carboidratos/genética , Secas , Regulação da Expressão Gênica de Plantas , Malus/fisiologia , Folhas de Planta/fisiologia , Parede Celular/metabolismo , Frutas/metabolismo , Glucosiltransferases/metabolismo , Malus/genética , Fotossíntese , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/fisiologia , Sorbitol/metabolismo , Estresse Fisiológico , Sacarose/metabolismo , beta-Frutofuranosidase/metabolismo
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