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1.
Insect Biochem Mol Biol ; 139: 103654, 2021 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-34571141

RESUMO

In insects, the juvenile hormone (JH) biosynthetic pathway regulates the in vivo JH titer. Thus, its downregulation potentially contributes to the lowering of JH titers typically observed in insects undergoing reproductive diapause, a developmental arrest at the adult stage. However, no systematic evidence has yet been presented to demonstrate the physiological and genetic roles of JH biosynthetic genes in reproductive diapause. In this work, we performed RNA interference (RNAi)-based reverse genetic analyses by targeting JH biosynthetic genes, followed by analysis of the reproductive diapause traits in Colaphellus bowringi, an economically important cabbage beetle. We identified a total of 22 genes encoding homologues of enzymes involved in the mevalonate pathway and the JH branch of JH biosynthesis in C. bowringi. Among these, 18 genes showed significant downregulation of their expression in the long day-induced diapausing females, compared to the short day-induced reproductive females. RNAi knockdown of almost any one of the 18 genes in reproductive females reduced the expression of the JH-responsive gene, Krüppel homolog1 (Kr-h1), indicating a lowered circulating JH. Most importantly, depleting transcripts of 3-hydroxy-3-methylglutaryl-CoA reductase 2 (HMGR2), farnesyl-pyrophosphate synthase 1 (FPPS1) and juvenile hormone acid methyltransferase 1 (JHAMT1) induced diapause-associated traits, including immature and inactive ovaries, large accumulations of lipids and adult burrowing behavior. Meanwhile, genes related to ovarian development, lipid accumulation and stress response showed expression patterns like those of diapausing females. RNAi-mediated diapause phenotypes could be reversed to reproductive phenotypes by application of methoprene, a JH receptor agonist. These results suggest that photoperiodic reproductive diapause in C. bowringi is triggered by transcriptional suppression of JH biosynthetic genes, with HMGR2, FPPS1 and JHAMT1 playing a critical role in this process. This work provides sufficient evidence to reveal the physiological roles of JH biosynthetic genes in reproductive diapause.

2.
BMC Plant Biol ; 21(1): 404, 2021 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-34488625

RESUMO

BACKGROUND: Brassica carinata (A) Braun has recently gained increased attention across the world as a sustainable biofuel crop. B. carinata is grown as a summer crop in many regions where high temperature is a significant stress during the growing season. However, little research has been conducted to understand the mechanisms through which this crop responds to high temperatures. Understanding traits that improve the high-temperature adaption of this crop is essential for developing heat-tolerant varieties. This study investigated lipid remodeling in B. carinata in response to high-temperature stress. A commercial cultivar, Avanza 641, was grown under sunlit-controlled environmental conditions in Soil-Plant-Atmosphere-Research (SPAR) chambers under optimal temperature (OT; 23/15°C) conditions. At eight days after sowing, plants were exposed to one of the three temperature treatments [OT, high-temperature treatment-1 (HT-1; 33/25°C), and high-temperature treatment-2 (HT-2; 38/30°C)]. The temperature treatment period lasted until the final harvest at 84 days after sowing. Leaf samples were collected at 74 days after sowing to profile lipids using electrospray-ionization triple quadrupole mass spectrometry. RESULTS: Temperature treatment significantly affected the growth and development of Avanza 641. Both high-temperature treatments caused alterations in the leaf lipidome. The alterations were primarily manifested in terms of decreases in unsaturation levels of membrane lipids, which was a cumulative effect of lipid remodeling. The decline in unsaturation index was driven by (a) decreases in lipids that contain the highly unsaturated linolenic (18:3) acid and (b) increases in lipids containing less unsaturated fatty acids such as oleic (18:1) and linoleic (18:2) acids and/or saturated fatty acids such as palmitic (16:0) acid. A third mechanism that likely contributed to lowering unsaturation levels, particularly for chloroplast membrane lipids, is a shift toward lipids made by the eukaryotic pathway and the channeling of eukaryotic pathway-derived glycerolipids that are composed of less unsaturated fatty acids into chloroplasts. CONCLUSIONS: The lipid alterations appear to be acclimation mechanisms to maintain optimal membrane fluidity under high-temperature conditions. The lipid-related mechanisms contributing to heat stress response as identified in this study could be utilized to develop biomarkers for heat tolerance and ultimately heat-tolerant varieties.


Assuntos
Brassica/metabolismo , Metabolismo dos Lipídeos , Lipídeos/química , Folhas de Planta/metabolismo , Estresse Fisiológico , Temperatura Alta
3.
Endocr Connect ; 10(8): 861-872, 2021 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-34319253

RESUMO

Plasma free fatty acids (FFAs) are elevated in obesity and can induce insulin resistance via endoplasmic reticulum (ER) stress. However, it is unknown whether hepatic insulin resistance caused by the elevation of plasma FFAs is alleviated by chemical chaperones. Rats received one of the following i.v. treatments for 48 h: saline, intralipid plus heparin (IH), IH plus the chemical chaperone 4-phenylbutyric acid (PBA), or PBA alone and a hyperinsulinemic-euglycemic clamp was performed during the last 2 h. PBA co-infusion normalized IH-induced peripheral insulin resistance, similar to our previous findings with an antioxidant and an IκBα kinase ß (IKKß) inhibitor. Different from our previous results with the antioxidant and IKKß inhibitor, PBA also improved IH-induced hepatic insulin resistance in parallel with activation of Akt. Unexpectedly, IH did not induce markers of ER stress in the liver, but PBA prevented IH-induced elevation of phosphorylated eukaryotic initiation factor-2α protein in adipose tissue. PBA tended to decrease circulating fetuin-A and significantly increased circulating fibroblast growth factor 21 (FGF21) without affecting markers of activation of hepatic protein kinase C-δ or p38 mitogen-activated protein kinase that we have previously involved in hepatic insulin resistance in this model. In conclusion: (i) PBA prevented hepatic insulin resistance caused by prolonged plasma FFA elevation without affecting hepatic ER stress markers; (ii) the PBA effect is likely due to increased FGF21 and/or decreased fetuin-A, which directly signal to upregulate Akt activation.

4.
Biomater Sci ; 9(13): 4648-4661, 2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34008632

RESUMO

Cancer resistance has been the huge challenge to clinical treatment. A photothermal therapy of second near-infrared (NIR-II) organic dye small molecule has been used to conquer the cancer resistance. However, the available NIR-II dye lacks selectivity and spreads throughout the body. It has toxicity and indiscriminate burn injuries normal cells and tissues during therapy. Hence, to improve the therapeutic outcomes, herein, for the first time, we report the mannose-modified zwitterionic nanoparticles loading IR1048 dye, aiming to overcome cancer cellular resistance. The targeting molecule mannose has been applied to modify zwitterionic polyester, and the obtained polyester is employed to load IR1048 to prolong the circulation time in the blood and improve the stability of loaded dye, due to the good cytocompatibility of polyester and the antifouling properties of zwitterions. In vitro experimental results show that the pH-responsive targeted nanoparticles display satisfactory photophysical properties, prominent photothermal conversion efficiency (44.07%), excellent photothermal stability, negligible cytotoxicity for normal cells and strong photothermal toxicity to drug-resistant cancer cells. Moreover, due to the mannose targeting effect, cancer cells can endocytose the nanoparticles effectively. All these results demonstrate potential application of this alternative hyperthermal delivery system with remote-controllable photothermal therapy of tumor for accurate diagnosis by NIR-II fluorescence imaging.


Assuntos
Hipertermia Induzida , Nanopartículas , Linhagem Celular Tumoral , Corantes Fluorescentes , Manose , Fototerapia , Terapia Fototérmica , Poliésteres
5.
J Plast Reconstr Aesthet Surg ; 74(8): 1908-1918, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33358677

RESUMO

BACKGROUND: Human adipose mesenchymal stem cells (hADSCs) show poor survival after transplantation, limiting their clinical application. Tissue regeneration resulting from stem cell treatment may be caused by attenuation of hypoxia-inducible factor-1α (HIF-1α). In this study, we constructed hADSCs stably expressing HIF-1α and investigated the potential effects of HIF-1α expression in the ischemic microenvironment on mitochondrial apoptosis and survival of hADSCs, and studied the mechanisms involved. METHOD: Apoptosis was induced by an ischemic microenvironment in vitro. ADSCs with stable HIF-1α expression were established. Cell survival and apoptosis were observed by CCK-8 assay, western blotting, flow cytometry, and fluorescence staining. ADSCs were subcutaneously transplanted into nude mice in the location where a hypoxia ischemic microenvironment was simulated in vivo. After 1, 3, and 7 d, mitochondrial apoptotic proteins were evaluated by immunohistochemistry and immunofluorescence staining. RESULTS: Exogenous HIF-1α downregulated mitochondrial reactive oxygen species, cytochrome c, caspase-9, and caspase-3, but inhibited mitochondrial membrane potential depolarization and increased the Bcl-2/bax ratio. HIF-1α prevented apoptosis and promoted vascular endothelial growth factor (VEGF) secretion as demonstrated by enzyme-linked immunosorbent assay (ELISA), terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining, and flow cytometry analysis. HIF-1α enhanced the survival of transplanted ADSCs in nude mice. CONCLUSION: We have shown that through inhibition of the mitochondria-mediated apoptotic pathway and promotion of VEGF secretion in hADSCs in an ischemic microenvironment, HIF-1α may potentially be applied in clinical therapy and as an alternative strategy for improving hADSC therapy.


Assuntos
Tecido Adiposo/citologia , Apoptose/fisiologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Isquemia/fisiopatologia , Mitocôndrias/metabolismo , Transplante de Células-Tronco , Adulto , Proliferação de Células , Sobrevivência Celular , Feminino , Humanos , Técnicas In Vitro
6.
Diabetes Metab Syndr Obes ; 13: 4787-4800, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33304104

RESUMO

Purpose: Diabetic Macular Edema has been one of the research hotspots all over the world. But as the global population continues to grow, the number of OCT images requiring manual analysis is becoming increasingly unaffordable. Medical images are often fuzzy due to the inherent physical processes of acquiring them. It is difficult for traditional algorithms to use low-quality data. And traditional algorithms usually only provide diagnostic results, which makes the reliability and interpretability of the model face challenges. To solve problem above, we proposed a more intuitive and robust diagnosis model with self-enhancement ability and clinical triage patients' ability. Methods: We used 38,057 OCT images (Drusen, DME, CNV and Normal) to establish and evaluate the model. All data are OCT images of fundus retina. There were 37,457 samples in the training dataset and 600 samples in the validation dataset. In order to diagnose these images accurately, we propose a multiscale transfer learning algorithm. Firstly, the sample is sent to the automatic self-enhancement module for edge detection and enhancement. Then, the processed data are sent to the image diagnosis module to determine the disease type. This process makes more data more effective and can be accurately classified. Finally, we calculated the accuracy, precision, sensitivity and specificity of the model, and verified the performance of the model from the perspective of clinical application. Results: The model proposed in this paper can provide the diagnosis results and display the detection targets more intuitively. The model reached 94.5% accuracy, 97.2% precision, 97.7% sensitivity and 97% specificity in the independent testing dataset. Conclusion: Comparing the performance of relevant work and ablation test, our model achieved relatively good performance. It is proved that the model proposed in this paper has a stronger ability to recognize diseases even in the face of low-quality images. Experiment results also demonstrate its clinical referral capability. It can reduce the workload of medical staff and save the precious time of patients.

7.
Carbohydr Polym ; 247: 116687, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32829815

RESUMO

Simultaneous stiffening, strengthening, and toughening of biodegradable polymers, such as poly(butylene adipate-co-terephthalate) (PBAT) and others, is necessary for their use in packaging and agriculture applications. However, a high content of nanoinclusions is usually required, leading to a tradeoff between composite toughness and strength or stiffness in the reinforcement. Herein, we report an iterative reinforcement strategy that uses one nanocomposite to reinforce PBAT. An in-situ grafting polymerized cellulose nanocrystal (CNC)/PBAT (CNC-g-PBAT) nanocomposite consisting of ungrafted/free PBAT (PBATf) was used as an inclusion directly to reinforce a commercial PBAT. At an exceptionally low CNC usage of 0.02 wt.%, we achieved a simultaneous enhancement of the Young's modulus by 26 %, tensile strength by 27 %, elongation at break by 37 %, and toughness by 56 % over those for PBAT. To the best of our knowledge, such reinforcement efficiency is the highest among similar biodegradable polymer nanocomposites reported in the literature. The rheology, differential scanning calorimetry, and wide-angle X-ray diffraction measurements confirmed the mechanical reinforcement attributed to a synergistic contribution from PBATf and CNC-g-PBAT. In particular, the use of PBATf enhanced both stiffness and toughness of the composites, while the CNC-g-PBAT interacted within the polymer matrix and increased the crystallinity of the polymer matrix, leading to the strengthening and toughening effect. The strategy proposed here is greatly beneficial to producing high-performance biodegradable polymer nanocomposite films for packaging and agricultural applications using a very low amount of nanoinclusion.


Assuntos
Plásticos Biodegradáveis/química , Nanocompostos/química , Poliésteres/química , Agricultura/métodos , Plásticos Biodegradáveis/síntese química , Varredura Diferencial de Calorimetria , Celulose/química , Elasticidade , Embalagem de Alimentos/métodos , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Transmissão , Nanocompostos/ultraestrutura , Nanopartículas/química , Reologia , Espectroscopia de Infravermelho com Transformada de Fourier , Resistência à Tração , Termogravimetria , Difração de Raios X
8.
J Environ Manage ; 270: 110878, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721317

RESUMO

Located in the hinterland of the Eurasian continent, the inland areas of northwestern China have an arid climate and are confronted with continuing challenges in water resources quantity and quality. Reclaimed water plays an important role in maintaining the sustainable use of urban water resources, especially in arid regions. In this paper, a system dynamics urban reclaimed water model (SDURWM) considering the status of arid regions in northwestern China was constructed. The supply and demand balance index (RWB) and the utilization efficiency index (RWUE) of reclaimed water were proposed as evaluation indicators. The potential of reclaimed water utilization (2016-2025) in three typical cities with similar natural environments and population sizes but with large economic differences were estimated by the SD model. Then the relevant values of reclaimed water quota, supply and resident awareness were adjusted within the range of 10%-20%. The predicted results from intervention demonstrate that the RWB of three cities will be closer or maintain to the ideal value, and that the RWUE will increase by about 0.1, compared with the non-intervention results. This indicates that a minor change of the targeted policies can invigorate the capacity of reclaimed water use in droughty cities. This paper provides some effective solutions for the government's planning of developing the potential of reclaimed water.


Assuntos
Purificação da Água , Água , China , Cidades , Abastecimento de Água
9.
Sci Total Environ ; 722: 137660, 2020 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-32179296

RESUMO

High salinity and low temperature are generally considered to have negative effects on the formation, stability and performance of aerobic granular sludge (AGS). This study investigated whether and how salinity acclimation strategies can enhance aerobic granulation at low temperature (12 °C) in three sequencing batch reactors (SBRs). Stepwise increased concentrations of NaCl (2-10 and 4-20 g/L) were added to the influent of R1 and R2 with steps of 1 and 2 g/L per week respectively, while R0 was set as a control (salt-free). The granulation processes in R1 and R2 were rapidly started up within 9 days, and were completed within 21 and 18 days, respectively. By contrast, R0 took 25 days and 49 days to start and complete granulation. The salinity acclimation strategies improved sludge hydrophobicity, reduced repulsion barrier between cells, and stimulated EPS production during granulation processes, which simultaneously promoted the formation of AGS. When the influent salinity reached 14 g/L on day 35, granule hydrophobicity, density and size in R2 sharply decreased and granules began to disintegrate afterwards. When operated under salt-free condition, sludge bulking occurred in R0 since day 60. The treatment performance was thus impaired in these two reactors, especially in R2 with significant biomass loss. Conversely, the AGS developed in R1 maintained stable structure with high biomass concentration (8.0 gSS/L) and excellent treatment performance for COD (90%), ammonium (95%) and total nitrogen (70%). Genera Thauera, Azoarcus, and Nitrosomonas were more enriched, while Flavobacterium and Meganema were more suppressed in R1, which would have contributed to granule stability and treatment performance. In conclusion, great care has to be taken for cultivating and operating AGS at low temperature for treating saline wastewater. Increasing salinity with a lower salt gradient provides a possibility for rapid granulation of AGS with excellent treatment performance under such conditions.


Assuntos
Salinidade , Aerobiose , Reatores Biológicos , Esgotos , Temperatura , Eliminação de Resíduos Líquidos
10.
Food Chem ; 302: 125186, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31400700

RESUMO

Enzymatic processing could reduce the allergenicity of peanut proteins while may lose the functional properties. Transglutaminase (TGase) is an enzyme for improving the functional properties of proteins/hydrolysates. No studies have been conducted on peanut hydrolysates that are crosslinked with TGase. In this study, allergenicity and functional properties of peanut protein hydrolysate cross-linked by TGase were tested. Papain, ficin and bromelain were selected out of eight food-grade enzymes for the kinetic analysis of peanut protein hydrolysis that lead to high reduction rate (K) of the IgE-binding property. Peanuts hydrolyzed by the three selected enzymes (200 AzU/g) were used for IgE binding, TGase-crosslinking and functional property characterization. After hydrolysis, the IgE-binding properties of the peanut soluble extracts were decreased (by 85%-95%); and functional properties were also decreased as compared to intact peanut protein extracts. The TGase crosslinked hydrolysates had similar IgE-binding properties to the un-crosslinked hydrolysates, but with higher functional properties.


Assuntos
Alérgenos/metabolismo , Arachis/imunologia , Proteínas de Plantas/metabolismo , Transglutaminases/metabolismo , Alérgenos/imunologia , Humanos , Hidrólise , Imunoglobulina E/metabolismo , Cinética , Proteínas de Plantas/imunologia
11.
Food Chem X ; 1: 100004, 2019 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31432004

RESUMO

Peanuts contain four major allergens with differences in allergenic potency. Thermal processing can influence the allergenic properties of peanuts. Until now, a kinetic model has not been reported to assess the changes of soluble allergen (extracted from processed peanuts) content as affected by various thermal processing methods. Our objective is to characterize the reaction kinetics of the thermal processing methods, including wet processing (boiling with/without high-pressure, steaming with/without high-pressure), deep-frying and dry processing (microwaving and roasting) using five time intervals. The relationships between processing time and extractable major allergen content could be explained by a simple linear regression kinetic model (except high-pressure steaming). Among all the methods with optimal processing point, frying for 6 min had a relatively lower IgE binding (linear epitopes) ratio, possibly due to the processing conditions, which caused break down, cross-linking and aggregation of Ara h 2, and a relatively lower solubility.

12.
ACS Omega ; 3(6): 6945-6954, 2018 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31458860

RESUMO

Acrylic pressure-sensitive adhesives with various polyester side-chain lengths were synthesized to investigate the effect of branching on phase separation and polymer mechanical performance. The polyester macromonomers (MMs) were produced through ring-opening co-polymerizations of l-lactide (l-LA) and ε-caprolactone (ε-CL) initiated with 2-hydroxyethyl methacrylate (HEMA), which provides the polyester chains with terminal vinyl groups. By varying the HEMA content, a range of MM chain lengths constructed from L10C4 (five l-LA and four ε-CL units) to L100C40 were obtained at a constant monomer mole ratio. Copolymerization of 2-ethylhexyl acrylate and acrylic acid with these MMs at constant mass composition provided a series of comb copolymers consisting of acrylic backbones with polyester branches of various chain lengths. Characterization of thin films cast from the polymers using thermal analysis and scanning probe microscopy showed a transition from a homogeneous phase to the formation of distinct microphases with increasing branching chain lengths. Rheological analysis of the linear viscoelastic responses was also used through small-amplitude oscillatory shear, and dynamic master curves were constructed by time-temperature superposition. The rheological data were also consistent with phase separation for the longer side-chain lengths of L50C20 and L100C40. The extra elastic contribution at low frequency and the temperature dependence of a T both show obviously effect of separated phases. Performance testing of polymer films showed that the chain extension resulted in a significant increase in both peel strength and shear resistance, which was accompanied by a modest decrease in film tackiness. The results demonstrate that tailoring branch chain structures provide a promising means for controlling the properties of the high-biomass content adhesive polymers.

13.
Langmuir ; 33(50): 14295-14303, 2017 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-29206047

RESUMO

Macroporous materials polymerized from high internal phase emulsions (PolyHIPEs) possess well-defined interconnected porous structures and tunable device shapes. This provides interesting property characteristics well-suited for a variety of applications. However, such materials also demonstrate poor mechanical performances, which limit their potential use. As will be demonstrated, this results from the high surfactant content required by PolyHIPEs. Herein, a new approach is introduced for designing a highly efficient polymeric surfactant, which generates interconnected pores in PolyHIPEs through designing an incompatible surfactant and skeleton material. The surfactant also possesses a hyperbranched topology, which combines the strong amphipathy of small molecular surfactants and the nanosphere structure of Pickering emulsifiers to provide an excellent colloidal stability to HIPEs. A hyperbranched polyethylene having pendant sodium sulfonate groups (HBPE-SO3Na) was thus designed and synthesized via chain walking copolymerization of ethylene and 2-trimethylsilyloxyethyl acrylate followed by sulfonation. Stable HIPEs of styrene/divinylbenzene and water at a weight ratio of 1 to 5 were obtained with using HBPE-SO3Na. The polymerization of HIPEs produced interconnected macroporous polystyrenes (PSs) at a substantially lower surfactant content, for example, 0.5 wt % HBPE-SO3Na. The compressive Young's moduli of PolyHIPEs reached 104-111 MPa with 0.5-2 wt % HBPE-SO3Na, which is the first reported case of a PS-based PolyHIPE achieving its theoretical modulus. The PolyHIPE was used to support Au nanoparticles and embed in a column for oxidation of dimethylphenylsilane. A complete conversion of dimethylphenylsilanol was achieved with low column back pressure in a 50 h continuous reaction with no degradation of PolyHIPE integrity and mechanical property.

14.
Chaos ; 27(11): 114324, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29195308

RESUMO

Type 2 diabetes mellitus (T2DM) has become prevalent pandemic disease in view of the modern life style. Both diabetic population and health expenses grow rapidly according to American Diabetes Association. Detecting the potential onset of T2DM is an essential focal point in the research of diabetes mellitus. The intravenous glucose tolerance test (IVGTT) is an effective protocol to determine the insulin sensitivity, glucose effectiveness, and pancreatic ß-cell functionality, through the analysis and parameter estimation of a proper differential equation model. Delay differential equations have been used to study the complex physiological phenomena including the glucose and insulin regulations. In this paper, we propose a novel approach to model the time delay in IVGTT modeling. This novel approach uses two parameters to simulate not only both discrete time delay and distributed time delay in the past interval, but also the time delay distributed in a past sub-interval. Normally, larger time delay, either a discrete or a distributed delay, will destabilize the system. However, we find that time delay over a sub-interval might not. We present analytically some basic model properties, which are desirable biologically and mathematically. We show that this relatively simple model provides good fit to fluctuating patient data sets and reveals some intriguing dynamics. Moreover, our numerical simulation results indicate that our model may remove the defect in well known Minimal Model, which often overestimates the glucose effectiveness index.


Assuntos
Glucose/administração & dosagem , Modelos Biológicos , Simulação por Computador , Teste de Tolerância a Glucose , Fatores de Tempo
15.
Acta Physiol Plant ; 39(10)2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31736527

RESUMO

In order to explore the salt-stress responses of two rice varieties, the physiological responses and biochemical responses were investigated using proteomics and classical biochemical methods. The results showed that the seedling growth was inhibited under salt condition in two rice varieties, the seedling growth in the tolerant variety was better than the sensitive variety. The sensitive variety(L7) appeared obvious salt-injury under 3-day salt stress, the tolerant variety (T07339) keep normal growth under 7-day salt stress except that the shoot length was decreased. Through the growth-parameters analysis, most of them in L7 were restrained by salinity and most in T07339 were unaffected. In T07339, the fresh root weight, the content of chlorophyll and the fresh shoot weight were even increased after 7 days of salt stress. A comparison of two-dimensional gel electrophoresis (2-DGE) protein profiles revealed 8 differently expressed proteins. Four proteins were expressed in different pattern between sensitive and tolerant varieties. These results provide novel insights into the investigations of the salt-response proteins that involved in improved salt tolerance.

16.
J Chromatogr A ; 1467: 347-355, 2016 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-27544751

RESUMO

The separation of aminoglutethimide enantiomers by the continuous multicolumn chromatographic processes were investigated experimentally and theoretically, where the columns were packed with cellulose tris 3,5-dimethylphenyl-carbamate stationary phase (brand name Chiralcel OD) and mobile phase was a mixture of n-hexane and ethanol with monoethanolamine additive. The continuous enantioseparation processes included a synchronous shifting process (SMB) and an asynchronous shifting process (VARICOL), which allowed reducing the column number (here from six-column SMB to five-column VARICOL process). Transport-dispersive model with the consideration of both intraparticle mass transfer resistance and axial dispersion was adopted to design and optimize the operation conditions for the separation of aminoglutethimide enantiomers by SMB process and VARICOL process. According to the optimized operation conditions, experiments were carried out on VARICOL-Micro unit using five-column VARICOL process with 1/1.5/1.5/1 configuration and six-column SMB process with 1/2/2/1 configuration. Products of R-aminoglutethimide (R-AG) enantiomer and S-aminoglutethimide (S-AG) enantiomer with more than 99.0% purity were obtained continuously from extract stream and raffinate stream, respectively. Furthermore, the experiemntal data obtained from five-column VARICOL process were compared with that from six-column SMB process, the feasibility and efficiency for the separation of guaifenesin enantiomers by VARICOL processes were evaluated.


Assuntos
Aminoglutetimida/química , Cromatografia/instrumentação , Aminoglutetimida/isolamento & purificação , Celulose/análogos & derivados , Etanol , Guaifenesina/química , Guaifenesina/isolamento & purificação , Hexanos , Indicadores e Reagentes , Organofosfatos , Fenilcarbamatos , Estereoisomerismo
17.
Front Plant Sci ; 7: 571, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27200044

RESUMO

Abiotic stress is a primary threat to fulfill the demand of agricultural production to feed the world in coming decades. Plants reduce growth and development process during stress conditions, which ultimately affect the yield. In stress conditions, plants develop various stress mechanism to face the magnitude of stress challenges, although that is not enough to protect them. Therefore, many strategies have been used to produce abiotic stress tolerance crop plants, among them, abscisic acid (ABA) phytohormone engineering could be one of the methods of choice. ABA is an isoprenoid phytohormone, which regulates various physiological processes ranging from stomatal opening to protein storage and provides adaptation to many stresses like drought, salt, and cold stresses. ABA is also called an important messenger that acts as the signaling mediator for regulating the adaptive response of plants to different environmental stress conditions. In this review, we will discuss the role of ABA in response to abiotic stress at the molecular level and ABA signaling. The review also deals with the effect of ABA in respect to gene expression.

18.
Food Chem ; 164: 98-103, 2014 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-24996311

RESUMO

In this work, a simple, rapid and sensitive analytical method for the determination of rhodamine B in chili-containing foodstuffs is described. The dye is extracted from samples with methanol and analysed without further cleanup procedure by high-performance liquid chromatography (HPLC) coupled to fluorescence detection (FLD). The influence of matrix fluorescent compounds (capsaicin and dihydrocapsaicin) on the analysis was overcome by the optimisation of mobile-phase composition. The limit of determination (LOD) and limit of quantification (LOQ) were 3.7 and 10 µg/kg, respectively. Validation data show a good repeatability and within-lab reproducibility with relative standard deviations <10%. The overall recoveries are in the range of 98-103% in chili powder and in the range of 87-100% in chili oil depending on the concentration of rhodamine B in foodstuffs. This method is suitable for the routine analysis of rhodamine B due to its sensitivity, simplicity, reasonable time and cost.


Assuntos
Capsicum/química , Cromatografia Líquida de Alta Pressão/métodos , Corantes de Alimentos/análise , Rodaminas/análise , Fluorescência , Limite de Detecção , Reprodutibilidade dos Testes , Espectrometria de Fluorescência , Especiarias/análise
19.
J Comput Biol ; 20(7): 524-39, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23829652

RESUMO

In modern systems biology the modeling of longitudinal data, such as changes in mRNA concentrations, is often of interest. Fully parametric, ordinary differential equations (ODE)-based models are typically developed for the purpose, but their lack of fit in some examples indicates that more flexible Bayesian models may be beneficial, particularly when there are relatively few data points available. However, under such sparse data scenarios it is often difficult to identify the most suitable model. The process of falsifying inappropriate candidate models is called model discrimination. We propose here a formal method of discrimination between competing Bayesian mixture-type longitudinal models that is both sensitive and sufficiently flexible to account for the complex variability of the longitudinal molecular data. The ideas from the field of Bayesian analysis of computer model validation are applied, along with modern Markov Chain Monte Carlo (MCMC) algorithms, in order to derive an appropriate Bayes discriminant rule. We restrict attention to the two-model comparison problem and present the application of the proposed rule to the mRNA data in the de-differentiation network of three mRNA concentrations in mammalian salivary glands as well as to a large synthetic dataset derived from the model used in the recent DREAM6 competition.


Assuntos
Algoritmos , Amilases/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Modelos Estatísticos , Glândula Parótida/citologia , RNA Mensageiro/genética , Proteínas e Peptídeos Salivares/genética , Amilases/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Teorema de Bayes , Humanos , Cadeias de Markov , Simulação de Dinâmica Molecular , Método de Monte Carlo , Glândula Parótida/metabolismo , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas e Peptídeos Salivares/metabolismo , Fatores de Tempo
20.
PLoS One ; 8(6): e64860, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23798995

RESUMO

Insulin signaling is essential for ß-cell survival and proliferation in vivo. Insulin also has potent mitogenic and anti-apoptotic actions on cultured ß-cells, with maximum effect in the high picomolar range and diminishing effect at high nanomolar doses. In order to understand whether these effects of insulin are constitutive or can be subjected to physiological modulation, it is essential to estimate the extracellular concentration of monomeric insulin within an intact islet. Unfortunately, the in vivo concentration of insulin monomers within the islet cannot be measured directly with current technology. Here, we present the first mathematical model designed to estimate the levels of monomeric insulin within the islet extracellular space. Insulin is released as insoluble crystals that exhibit a delayed dissociation into hexamers, dimers, and eventually monomers, which only then can act as signaling ligands. The rates at which different forms of insulin dissolve in vivo have been estimated from studies of peripheral insulin injection sites. We used this and other information to formulate a mathematical model to estimate the local insulin concentration within a single islet as a function of glucose. Model parameters were estimated from existing literature. Components of the model were validated using experimental data, if available. Model analysis predicted that the majority of monomeric insulin in the islet is that which has been returned from the periphery, and the concentration of intra-islet monomeric insulin varies from ~50-300 pM when glucose is in the physiological range. Thus, our results suggest that the local concentration of monomeric insulin within the islet is in the picomolar 'sweet spot' range of insulin doses that activate the insulin receptor and have the most potent effects on ß-cells in vitro. Together with experimental data, these estimations support the concept that autocrine/paracrine insulin signalling within the islet is dynamic, rather than constitutive and saturated.


Assuntos
Comunicação Autócrina , Células Secretoras de Insulina/fisiologia , Insulina/fisiologia , Modelos Biológicos , Algoritmos , Líquido Extracelular/metabolismo , Glucose/fisiologia , Humanos , Ilhotas Pancreáticas/citologia , Cinética , Transdução de Sinais
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