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1.
Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited heart muscle disease that may result in arrhythmia, heart failure and sudden death. The hallmark pathological findings are progressive myocyte loss and fibro fatty replacement, with a predilection for the right ventricle. This study focuses on the adipose tissue formation in cardiomyocyte by considering the signal transduction pathways including Wnt/ β ‐catenin and Wnt/Ca2+ regulation system. These pathways are modelled and analysed using stochastic petri nets (SPN) in order to increase our comprehension of ARVC and in turn its treatment regimen. The Wnt/ β ‐catenin model predicts that the dysregulation or absence of Wnt signalling, inhibition of dishevelled and elevation of glycogen synthase kinase 3 along with casein kinase I are key cytotoxic events resulting in apoptosis. Moreover, the Wnt/Ca2+ SPN model demonstrates that the Bcl2 gene inhibited by c‐Jun N‐terminal kinase protein in the event of endoplasmic reticulum stress due to action potential and increased amount of intracellular Ca2+ which recovers the Ca2+ homeostasis by phospholipase C, this event positively regulates the Bcl2 to suppress the mitochondrial apoptosis which causes ARVC.Inspec keywords: molecular biophysics, enzymes, cancer, muscle, Petri nets, cellular biophysics, bioelectric potentials, biomembranes, tumours, cardiology, genetics, biochemistry, calciumOther keywords: heart failure, sudden death, hallmark pathological findings, progressive myocyte loss, fibro fatty replacement, adipose tissue formation, signal transduction pathways, Ca2+ regulation system, stochastic petri nets, ARVC, $β‐catenin model, Wnt signalling, glycogen synthase kinase 3, Bcl2 gene, c‐Jun N‐terminal kinase protein, petri Net modelling approach, Ca2+ signalling pathways, arrhythmogenic right ventricular cardiomyopathy, inherited heart muscle disease, Ca2+ SPN model, Ca  相似文献   

2.
The present study focused on the synthesis of spherical silver nanoparticles (Ag NPs) using Gundelia tournefortii L. aerial part extract. The plant extract could reduce silver ions into Ag NPs. To identify the compounds responsible for the reduction of silver ions, functional groups present in plant extract were investigated by Fourier transform infrared spectroscopy. Techniques used to characterise synthesised nanoparticles included field emission scanning electron microscopy, X‐ray diffraction and transmission electron microscopy. UV‐visible spectrophotometer showed the absorbance peak in the range of 400–450 nm. The Ag NPs showed antibacterial activities against both gram positive (Staphylococcus aureus and Bacillus Cereus) and gram negative (Salmonella typhimurium and Escherichia coli) microorganisms. The results confirmed that this protocol was simple, rapid, eco‐friendly, low‐priced and non‐toxic; therefore, it could be used as an alternative to conventional physical/chemical methods. Only 5 min were required for the conversion of silver ions into Ag NPs at room temperature, without the involvement of any hazardous chemical.Inspec keywords: nanoparticles, silver, nanofabrication, microorganisms, Fourier transform infrared spectra, transmission electron microscopy, ultraviolet spectra, visible spectraOther keywords: Ag, temperature 293 K to 298 K, chemical method, physical method, Salmonella typhimurium, Escherichia coli, gram negative microorganisms, Bacillus Cereus, Staphylococcus aureus, gram positive microorganisms, antibacterial activities, absorbance peak, UV‐visible spectrophotometer, transmission electron microscopy, X‐ray diffraction, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, functional groups, plant extract, Gundelia tournefortii L. aerial part extract, spherical silver nanoparticle synthesis, silver nanoparticle green synthesis, natural source  相似文献   

3.
Buffer allocation in serial production lines is one of the important design issues, and hence it has been studied extensively in the literature. In this paper, we analyse the problem to characterise the optimal buffer allocation; specifically, we study the cases with single and multiple bottleneck stations under various experimental conditions. In addition, we develop an efficient heuristic procedure to allocate buffers in serial production lines to maximise throughput. The results of the computational experiments indicate that the proposed algorithm is very efficient in terms of both solution quality and CPU time requirements. Moreover, the characterisation study yields interesting findings that may lead to important practical implications. A comprehensive bibliography is also provided in the paper.  相似文献   

4.
In this study, the bacterial strain CEES 33 was isolated from the coastal area of the Red Sea, Jeddah, Kingdom of Saudi Arabia. The bacterium isolate was identified and characterized by using biochemical and molecular methods. The isolate CEES 33 has been identified as Gram‐negative rod shaped and cream pigmented spherical colonies. It also demonstrated a positive result for nitrate reduction, oxidase, catalase, citrate utilization, lipase and exopolysaccharide production. Strain CEES 33 was characterized at the molecular level by partial 16S rRNA sequencing and it has been identified as Marinobacter lipolyticus (EMBL|LN835275.1). The lipolytic activity of the isolate was also observed 2.105 nkatml−1. Furthermore, the bacterial aqueous extract was used for green synthesis of silver nanoparticles (AgNPs), which was further confirmed by UV‐visible spectra (430 nm), XRD and SEM analysis. Moreover, the biological functional group that involved in AgNPs synthesis was confirmed by FTIR spectra. The biological activities of AgNPs were also investigated, which showed a significant growth inhibition of Candida albicans with 16 ± 2 mm zone of inhibition at 10 μg dose/wells. Therefore, bacterium Marinobacter lipolyticus might be used in future for lipase production and nanoparticles fabrication for biomedical application, to control fungal diseases caused by C. albicans.Inspec keywords: enzymes, molecular biophysics, biochemistry, silver, nanoparticles, nanofabrication, nanomedicine, antibacterial activity, biomedical materials, ultraviolet spectra, visible spectra, Fourier transform infrared spectra, microorganisms, reduction (chemical), RNA, molecular configurations, X‐ray diffraction, scanning electron microscopy, diseasesOther keywords: lipase production, silver nanomaterial modulation, anticandidal activities, bacterial strain CEES 33, bacterial isolate, biochemical method, molecular method, gram‐negative rod shaped colonies, cream pigmented spherical colonies, nitrate reduction, oxidase, catalase, citrate utilisation, exopolysaccharide production, molecular level, partial 16S rRNA sequencing, Marinobacter lipolyticus strain EMBL|LN835275.1, lipolytic activity, bacterial aqueous extract, green synthesis, UV‐visible spectra, X‐ray diffraction, scanning electron microscopy, biological functional group, AgNPs synthesis, Fourier transform infrared spectroscopy, Candida albicans, media plate, industrial lipase production, biomedical application, fungal diseases, wavelength 430 nm, Ag  相似文献   

5.
The present study reports an eco‐friendly and rapid method for the synthesis of core–shell nanoclusters using the modified reverse micelle method. It is a green synthetic method which uses Sesbania grandiflora Linn extract which acts as a reducing and capping agent. It is observed that this method is very fast and convenient and the nanoclusters are formed with 5–10 min of the reaction time without using harsh conditions. The core–shell nanoclusters so prepared were characterised using UV–Vis spectroscopy, scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, and X‐ray photoelectron spectroscopy. Further, their effective antibacterial activity towards the gram‐positive bacteria Staphylococcus aureus was found to be due to their smaller particle size.Inspec keywords: iron compounds, copper compounds, nanoparticles, particle size, nanofabrication, nanomedicine, biomedical materials, core‐shell nanostructures, antibacterial activity, ultraviolet spectra, visible spectra, microorganisms, reduction (chemical), scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectraOther keywords: biosynthesis, γ‐Fe2 O3 ‐CuO core‐shell nanoclusters, aqueous extract, Sesbania grandiflora Linn fresh leaves, antimicrobial activity, Staphylococcus aureus strains, eco‐friendly method, modified reverse micelle method, green synthetic method, reducing agent, capping agent, UV‐visible spectroscopy, scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, antibacterial activity, gram‐positive bacteria Staphylococcus aureus, particle size, time 5 min to 10 min, Fe2 O3 ‐CuO  相似文献   

6.
Phytomedicine research received tremendous attention for novel therapeutic agent due to their safety and low cost. We assessed a novel nanoformulation of Biophytum sensitivum (BS), natural flavonoids for their improved efficacy and superior bioavailability against crude extract for prostate cancer cells (PC3). We prepared a nanomedicine of BS by nanoprecipitation method and size analysis via DLS and SEM revealed a range of 100–118 nm and surface zeta potential as −9.77 mV. FTIR was performed to evaluate functional for presence of carbonyl and aromatic rings, respectively. Human PC3 cells showed concentration at 0.5, 0.8, and 1 mg/ml dependent cytotoxicity 22, 39, and 56% for 24 h, whereas 43, 41, and 67% for 48 h of BS nanomedicine compared with crude 11, 22, and 53% for 24 h and 38, 31, and 60% for 48 h, respectively. Haemocompatibility of BS nanomedicine at the concentration of 0.5, 0.8, and 1 mg/ml did not show blood aggregation. Cellular uptake was confirmed using rhodamine‐conjugated BS nanomedicine for 48 h. Interestingly, BS nanomedicine 1 mg/ml decreases the nitrite productions in PC3 cells. Collectively, BS nanomedicine has the potential anti‐cancer agents with biocompatible and enhanced efficacy can be beneficial for the treatment of prostate cancerInspec keywords: nanomedicine, cancer, cellular biophysics, tumours, solubility, scanning electron microscopy, electrokinetic effects, Fourier transform infrared spectra, bloodOther keywords: Biophytum sensitivum, cell viability, nitrite production, prostate cancer cells, phytomedicine, therapeutic agent, natural flavonoids, pharmacological anti‐tumour agent, anti‐cancer agent, aqueous solubility, metabolism, dissolution rates, bioavailability, dynamic light scattering, scanning electron microscopy, surface zeta potential, FTIR, cytotoxicity, haemocompatibility, blood aggregation, cellular uptake level, cell membrane, cell nucleus, rhodamine‐conjugated BS nanomedicine, wave number 3358.07 cm‐1 , wave number 2312.65 cm‐1 , wave number 1737.86 cm‐1 , wave number 1508.33 cm‐1 , time 24 h, time 48 h  相似文献   

7.
Nanoscale aluminium trihydroxide (ATH) is examined to its suitability for carbon fibre reinforced plastics (CFRP) as a novel flame retardant. In particular the influence of particle size and concentration of ATH to the fire behaviour of epoxy polymer matrices is determined. The particle size is adjusted by means of different dispersing techniques. By SEM images and viscosity measurements the homogeneity of the produced ATH dispersions for the liquid ones and of cured epoxy–ATH nanocomposites is determined. Based on these pre-results, selected ATH dispersions are used for the manufacturing of CFRP which are produced by the proved injection technology. The thermal stability of the ATH nanocomposite plates and the corresponding CFRP plates are analyzed by means of quantitative single difference thermoanalysis (QSDTA). The fire behaviour is characterised by using the OSU chamber test. Both tests indicate a reduced heat release rate by decreasing the ATH particle size, i.e. the thermal load decreases. A combined fire protection mechanism is discussed for the improved fire protection through ATH nanoparticles.  相似文献   

8.
A growing number of research information systems use a semantic linkage technique to represent in explicit mode information about relationships between elements of its content. This practice is coming nowadays to a maturity when already existed data on semantically linked research objects and expressed by this scientific relationships can be recognized as a new data source for scientometric studies. Recent activities to provide scientists with tools for expressing in a form of semantic linkages their knowledge, hypotheses and opinions about relationships between available information objects also support this trend. The study presents one of such activities performed within the Socionet research information system with a special focus on (a) taxonomy of scientific relationships, which can exist between research objects, especially between research outputs; and (b) a semantic segment of a research e-infrastructure that includes a semantic interoperability support, a monitoring of changes in linkages and linked objects, notifications and a new model of scientific communication, and at last—scientometric indicators built by processing of semantic linkages data. Based on knowledge what is a semantic linkage data and how it is stored in a research information system we propose an abstract computing model of a new data source. This model helps with better understanding what new indicators can be designed for scientometric studies. Using current semantic linkages data collected in Socionet we present some statistical experiments, including examples of indicators based on two data sets: (a) what objects are linked and (b) what scientific relationships (semantics) are expressed by the linkages.  相似文献   

9.
CO2 concentration ([CO2]) in a greenhouse may be a limiting factor for plant growth. Current greenhouse CO2 control strategy usually depends on expert experience, which may control [CO2] in a moderate range but cannot make it optimal due to lack of considering plant photochemistry reactions. A state‐space kinetic model structure covering major photosynthetic reactions as affected by CO2 is useful for [CO2] control strategy development in a greenhouse because modern control theories are usually based on state‐space models. In this work, a state‐space kinetic model structure for photosynthesis was built, which describes the major reaction cascades of photophosphorylation, Calvin cycle, and biophysical processes such as CO2 transport through the stomata under moderate [CO2] range without considering photorespiration. Simulations were performed with a large range of model parameters to demonstrate the effect of [CO2] on stable sugar production and the flexibilities of the developed model structure. The results clearly show whether increasing of CO2 will lead to more production of sugar or not in different scenarios. The model structure may be extended to cover other photosynthetic influence factors such as temperature by using the well‐known Arrhenius equation.Inspec keywords: state‐space methods, botany, photosynthesis, vegetation, carbon compounds, agricultural engineeringOther keywords: photosynthetic activities, plant growth, plant photochemistry reactions, state‐space kinetic model structure, photosynthetic reactions, state‐space control strategy development, greenhouse, photophosphorylation, Calvin cycle, photorespiration, Arrhenius equation, C3 , CO2   相似文献   

10.
The aim of this study was to develop a new fast-disintegrating tablet formulation containing 1?mg tacrolimus for sublingual application. First, solid dispersions containing tacrolimus (2.5%, 5% and 10% w/w) incorporated in Ac-Di-Sol(?) and carriers (inulin 1.8?kDa and 4?kDa, and polyvinylpyrrolidone (PVP) K30) were prepared by freeze drying. Subsequently, a tablet formulation composed of a mixture of the solid dispersions, Ac-Di-Sol(?), mannitol, Avicel(?) PH-101 and sodium stearyl fumarate was optimized concerning drug load in the solid dispersions and the type of carrier. Tablet weight was kept constant at 75?mg by adjusting the amount of Avicel(?) PH-101. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRPD) results indicated the absence of the drug in the crystalline state, which was confirmed by the scanning electron microscopy (SEM). These results suggest that tacrolimus incorporated in all of the solid dispersions was fully amorphous. Dissolution of the tablets containing solid dispersions with a low drug load highly depends on the type of carrier and increased in the order: PVP K30 < inulin 4?kDa < inulin 1.8?kDa. Solid dispersions with a drug load of 10% w/w incorporated in the carriers yielded optimal formulations. In addition, the physicochemical characteristics and the dissolution behavior of the tablet formulation containing inulin 1.8 kDa-based solid dispersions with a drug load of 10% w/w did not change after storage at 20°C/45%RH for 6 months indicating excellent storage stability.  相似文献   

11.
Architecture and composition of Scaffolds are influential factors in the regeneration of defects. Herein, synthesised iron oxide (magnetite) nanoparticles (MNPs) by co‐precipitation technique were evenly distributed in polylactic‐co‐glycolic acid (PLGA)–gelatine Scaffolds. Hybrid structures were fabricated by freeze‐casting method to the creation of a matrix with tunable pores. The synthesised MNPs were characterised by transmission electron microscopy, Fourier transform infrared spectroscopy, X‐ray diffraction spectroscopy, and vibrating sample magnetometer analysis. Scanning electron microscopy micrographs of porous Scaffolds confirmed the formation of unidirectional microstructure, so that pore size measurement indicated the orientation of pores in the direction of solvent solidification. The addition of MNPs to the PLGA–gelatine Scaffolds had no particular effect on the morphology of the pores, but reduced slightly pore size distribution. The MNPs contained constructs demonstrated increased mechanical strength, but a reduced absorption capacity and biodegradation ratio. Stability of the MNPs and lack of iron release was the point of strength in this investigation and were determined by atomic absorption spectroscopy. The evolution of rat bone marrow mesenchymal stem cells performance on the hybrid structure under a static magnetic field indicated the potential of super‐paramagnetic constructs for further pre‐clinical and clinical studies in the field of neural regeneration.Inspec keywords: transmission electron microscopy, biodegradable materials, nanofabrication, freezing, mechanical strength, tissue engineering, X‐ray diffraction, cellular biophysics, precipitation (physical chemistry), biomedical materials, iron compounds, porosity, scanning electron microscopy, atomic absorption spectroscopy, gelatin, nanoparticles, porous materials, bone, nanocomposites, Fourier transform infrared spectraOther keywords: unidirectional microstructure, pore size measurement, mechanical strength, atomic absorption spectroscopy, hybrid structure, super‐paramagnetic responsive PLGA–gelatine–magnetite scaffolds, unidirectional porous structure, tissue engineering Scaffolds, co‐precipitation technique, polylactic‐co‐glycolic acid–gelatine Scaffolds, freeze‐casting method, transmission electron microscopy, Fourier‐transform infrared spectroscopy, X‐ray diffraction spectroscopy, scanning electron microscopy micrographs, pore size distribution, absorption capacity, iron oxide nanoparticles, Fe3 O4   相似文献   

12.
Blind source separation (BSS) is a general signal processing method, which consists of recovering from a finite set of observations recorded by sensors, the contributions of different physical sources independently of the propagation medium and without any a priori knowledge of the sources. Recently, these methods paved a new way for the monitoring or the diagnosis of mechanical systems in a working environment. Actually, we show that BSS allows recovering the vibratory information issued from a single rotating machine working in a noisy environment by freeing the sensor signal from the contribution of other working machines. In that way, BSS can be used as a pre-processing step for rotating machine fault detection and diagnosis.  相似文献   

13.
This paper describes a case-study in the development of a new type of woven glass/epoxy prepreg for use in marine and civil infrastructure applications. Experimental tests were performed on the prepreg at different levels of matrix cure between 1% and 59% to determine the condition that provides the optimum handling, drape and tack properties at room temperature. Bias extension testing was used to characterise the shear resistance and residual stress, bending stiffness tests to assess the drape, and peel tests to determine the tack of the prepregs. A low level of cure (<20%) provided the prepreg with excellent handling and drape properties due to the low complex viscosity of the resin. However, the low cure level resulted in the prepreg having insufficient tack. A high level of cure (59%), on the other hand, provided poor handling, drape and tack properties. The optimum level of cure was found to be approximately 30%, which combined an acceptable level of handling, low residual stress, high drape and good tack. Based on this research, a new type of prepreg is being produced in commercial quantities in Australia for domestic use and overseas export.  相似文献   

14.
Background: Nitric oxide (NO) is a gaseous transmitter playing numerous physiological roles and characterized by a short half-life. Its binding to endogenous thiols increases its stability, facilitating its storage and transport. The purpose of this study was to investigate the nitrosated serum albumin (SA-SNO) and to provide a reference for its easy preparation for further use in in vitro studies.

Methods: Serum albumin (SA) was S-nitrosated by reacting with (i) NaNO2 in acidic medium; (ii) different low-molecular weight S-nitrosothiols (RSNO) (S-nitrosocysteine (CysNO), S-nitrosoglutathione (GSNO), and S,S'-dinitrosobucillamine (Buc(NO)2)); and (iii) diethylamine NONOate (DEA/NO). SA-SNO was purified by size exclusion chromatography and the S-nitrosation site and the rate were studied by mass spectrometry and Griess–Saville assay, respectively. Then, SA-SNO was characterized by spectrofluorimetry, dynamic light scattering, and circular dichroism. Finally, SA-SNO reactivity with citrate stabilized gold nanoparticles (AuNP-citrate) was investigated via determination of NO release.

Results: S-nitrosation rates of SA were 90.1?±?3.3, 76.8?±?2.7, 80.3?±?3.2, 84.8?±?5.0, and 15.4?±?1.9% (n?=?5), when SA was reacted with acidified NaNO2, CysNO, GSNO, Buc(NO)2, and DEA/NO, respectively. The physicochemical characterization indicated that the resulting product corresponded to a mono-S-nitrosothiol (on cysteine-34), and the conformational construction remained unchanged. Stability studies showed that the NO content was preserved over 1 week. AuNP-citrate reacted with SA-SNO with increase of its hydrodynamic diameter but preservation of SNO bond.

Conclusions: SA-SNO prepared and stored under the reported conditions affords a well-defined reference suitable for in vitro studies.  相似文献   

15.
This work aims at developing and optimizing a valuable oral delivery carrier for the cannabinoid derivative CB13, which presents a high therapeutic potential in chronic pain states that respond poorly to conventional analgesics, but also shows highly unfavorable physicochemical properties. CB13-loaded lipid nanoparticles (LNP) formulations were developed through solvent-emulsion evaporation and optimized in terms of physicochemical properties, long-term stability, integrity under gastric simulated conditions and in vitro interaction with NIH 3T3, HEK 293T and Caco-2 cells. An optimized formulation of LNP containing CB13 was obtained from a wide range of conditions assayed and analyzed. The selection of the lipid core, production conditions and the inclusion of lecithin proved to be key factors for the final properties of encapsulation, integrity and performance of the carriers. The LNP formulation proposed proved to be a promising carrier for the oral delivery of CB13, a cannabinoid with high therapeutic potential in chronic pain states that currently lack a valid oral treatment.  相似文献   

16.
Franck-Condon factor arrays have been computed numerically to high vibrational quantum numbers for the band systems N2:C3IIB3II(Second Positive)N2:B3IIA3(First Positive)N2:A3X1(Vegard Kaplan)N2:a1IIX1(Lyman-Birge-Hopfield)N2+;A2IIX2(Meinel)N2+:B2X2(First Negative)and for the following ionization transitions N2X1N2+X2N2X1N2+A2IIN2X1N2+B2  相似文献   

17.
A chemoselective reductive method has been achieved for the preparation of 4-picrylamino-2,6-dinitrotoluene (PADNT), a new insensitive energetic material which has been characterised by spectral data and elemental analysis. Some explosive properties of the compound have also been determined and the results indicate that PANDT is quite safe to impact and friction.  相似文献   

18.
Gadolinium as a contrast agent in MRI technique combined with DTPA causes contrast induced nephropathy (CIN) and nephrogenic systemic fibrosis (NSF) which can reduce by usage of antioxidants such as N‐acetyl cysteine by increasing the membrane''s permeability leads to lower cytotoxicity. In this study, N ‐acetyl cysteine‐PLGA Nano‐conjugate was synthesized according to stoichiometric rules of molar ratios andafter assessment by FTIR, NMR spectroscopy and Atomic Force Microscopy (AFM) imaging was combined with Magnevist® (gadopentetate dimeglumine) and its effects on the renal cells were evaluated. MTT [3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐Diphenyltetrazolium Bromide] and cellular uptake assays have indicated relatively significant toxicity of magnevist (P  < 0.05) on three cell lines including HEK293, MCF7 and L929 compared to other synthesized ligands that shown no toxicity. Moreover, systemic evaluation has shown no notable changes of blood urea nitrogen (BUN) and creatinine in kidney of mice. In consequence, antioxidant effect was increased as well as the renal toxicity of the contrast agent reduced at the cell level. As a result, PLGA‐NAC nano‐conjugate can be a promising choice for decreasing the magnevist toxicity for treatment and prevention of CIN and will be able to open a new horizon to research on reduction of toxicity of contrast agents by using nanoparticles.Inspec keywords: blood, toxicology, nanofabrication, cellular biophysics, biomedical materials, nanoparticles, chromatography, cancer, biodegradable materials, biomedical MRI, kidney, pH, nanomedicine, patient treatment, diseases, atomic force microscopy, Fourier transform infrared spectraOther keywords: cellular toxicity, gadopentate dimeglumine, contrast agent, magnetic resonance imaging technique, diethylenetriamine pentaacetate, contrast‐induced nephropathy, nephrogenic systemic fibrosis, stoichiometric rules, molar ratios, dimethyl sulphoxide solution, chromatography techniques, nuclear magnetic resonance spectroscopy, atomic force microscopy imaging, Magnevist®, gadopentetate dimeglumine, renal cells, MTT cytotoxicity, human embryonic kidney‐293, L929 cell lines, in vitro conditions, cellular uptake assays, Magnevist uptake, antioxidant effect, renal toxicity, cell level, PLGA nanocarrier, acetylcysteine nanoconjugate, Magnevist toxicity, N‐acetylcysteine–PLGA nano‐conjugate, N‐acetyl cysteine‐poly‐lactic‐co‐glycolic acid nanoconjugate  相似文献   

19.
《Composites Part A》2004,35(1):11-16
A new cost effective method of fabricating strong plywood-type composites from strips of hemp fibres is reported, which takes advantage of the first frosts in autumn. The extracellular ice formed in the plants detaches the fibre layers from the woody material. In a three-point bending test 20×20×100 mm3 fibre/epoxy test beams with a similar structure to that of plywood were found to be of comparable strength, the highest flexural strength being 65 MPa. A two-component epoxy resin (Araldite®) was used as an adhesive. The mass fraction of the strips was 50–80%. The compressive stress during the manufacturing process was 0.1 or 8 MPa. The good appearance, manufacturing properties and workability of the biofibre composites make them suitable especially for floor and furniture manufacture.By pressing together 48 layers of hemp or flax mats which were originally intended for insulation purposes composites were produced that were even stronger than those made from strips. Hemp was spring harvested, which somewhat reduced the strength of fibre bundles. The great advantage of spring harvesting hemp fibre is that no artificial retting or drying is needed which makes the industrial raw materials, and therefore the final products, economically attractive. The highest flexural strengths of the test beams were around 140 MPa and stiffness 6 GPa with a fibre mass fraction of 50–60%. A 6 MPa compressive stress was applied during the manufacturing process.  相似文献   

20.
In this study, the authors developed pectin‐stabilised selenium nanoparticles (pectin‐SeNPs) for curcumin (Cur) encapsulation and evaluated their physicochemical properties and biological activities. Results showed that pectin‐SeNPs and Cur‐loaded pectin‐SeNPs (pectin‐SeNPs@Cur) exhibited monodisperse and homogeneous spherical structures in aqueous solutions with mean particle sizes of ∼61 and ∼119 nm, respectively. Cur was successfully encapsulated into pectin‐SeNPs through hydrogen bonding interactions with an encapsulation efficiency of ∼60.6%, a loading content of ∼7.4%, and a pH‐dependent and controlled drug release in vitro. After encapsulation was completed, pectin‐SeNPs@Cur showed enhanced water solubility (∼500‐fold), dispersibility, and storage stability compared with those of free Cur. Moreover, pectin‐SeNPs@Cur possessed significant free radical scavenging ability and antioxidant capacity in vitro, which were stronger than those of pectin‐SeNPs. Antitumour activity assay in vitro demonstrated that pectin‐SeNPs@Cur could inhibit the growth of HepG2 cells in a concentration‐dependent manner, and the nanocarrier pectin‐SeNPs exhibited a low cytotoxic activity against HepG2 cells. Therefore, the results suggested that pectin‐SeNPs could function as effective nanovectors for the enhancement of the water solubility, stability, and in vitro bioactivities of hydrophobic Cur.Inspec keywords: hydrogen bonds, selenium, nanoparticles, solubility, drug delivery systems, toxicology, hydrophobicity, free radicals, particle size, nanofabrication, cancer, nanomedicine, drugs, biomedical materials, encapsulation, cellular biophysics, pH, organic compoundsOther keywords: pectin‐decorated selenium nanoparticles, pectin‐stabilised selenium nanoparticles, curcumin encapsulation, Cur‐loaded pectin‐SeNPs, nanocarrier pectin‐SeNPs, physicochemical properties, biological properties, homogeneous spherical structures, monodisperse spherical structures, aqueous solutions, particle size, hydrogen bonding interactions, encapsulation efficiency, loading content, pH‐dependent drug release, in vitro controlled drug release, water solubility, free radical scavenging ability, in vitro antioxidant capacity, in vitro antitumour activity assay, HepG2 cells, cytotoxic activity, in vitro bioactivity, hydrophobic curcumin, Se  相似文献   

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