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101.
In this study, a model hydrophilic drug (porphyrin) was encapsulated within hydrophobic polylactic acid (PLA) nanoparticles (NPs) with different crystallinity and the relevant release behaviors were investigated. The crystalline modification was done using a modified nanoprecipitation method, where homo and stereocomplexed PLA NPs with different average diameters based on varying polymer concentrations and solvent/nonsolvent ratios (S/N) were prepared. Entrapment efficiency and drug release of sterocomplexed-PLA NPs were compared with neat poly(l -lactic acid) (PLLA) NPs. Furthermore, to get the more sustained release, porphyrin-loaded NPs were immobilized within electrospun poly(d ,l -lactide-co-glycolide (PLGA) nanofibers (NFs). Outcomes revealed that solution concentration and solvent/nonsolvent ratio play significant roles in the formation of homo and stereocomplexed NPs. On the other hand, it was found that the formation of stereocrystals did not significantly affect the size and morphology of NPs compared with neat NPs. With regard to the entrapment efficiency and drug content, stereocomplexd-PLA NPs behave relatively the same as neat PLLA NPs while the more sustained release was observed for stereocomplexed NPs. Also, it was observed that electrospinning of PLGA solution loaded by NPs led to the uniform distribution of NPs into PLGA fibers. Encapsulating the drug-loaded NPs into nanofibers decreased the rate of drug release by 50% after 24 h, compared with direct loading of drug into PLGA NFs. We conclude that it is possible to tune the entrapment efficiency and modify the release rate of the drug by giving small changes in the process parameters without altering the physical properties of the original drug substance and polymer. 相似文献
102.
A new high: Cannabis as a budding source of carbon-based materials for electrochemical power sources
Zahra I. Rana Ami R. Shah Alice V. Llewellyn Katrina Mazloomian Patricia McAlernon Thomas S. Miller Patrick L. Cullen Paul R. Shearing Dan J.L. Brett 《Current Opinion in Electrochemistry》2022
Cannabis sativa L., a low-cost, fast-growing herbaceous plant, is seeing a resurgence in widespread cultivation as a result of new policies and product drive. Its biodegradable and environmentally benign nature coupled with its high specific surface area and three-dimensional hierarchal structure makes it an excellent candidate for use as a biomass-derived carbon material for electrochemical power sources. It is proposed that this ‘wonder crop’ could have an important role in the energy transition by providing high-functioning carbon-based materials for electrochemistry. In this article, all instances of C. sativa usage in batteries, fuel cells and supercapacitors are discussed with a focus on highlighting the high capacity, rate capability, capacitance, current density and half-wave potential that can be achieved with its utilisation in the field. 相似文献
103.
Kamyabi Mohammad Ali Alipour Zahra Moharramnezhad Mohsen 《Journal of Solid State Electrochemistry》2021,25(2):445-456
Journal of Solid State Electrochemistry - Here is reported a new feasible and facile method for the determination of amoxicillin by the electrochemiluminescence (ECL) method. The ECL signal was... 相似文献
104.
Structural Chemistry - The measured densities and viscosities of the binary mixtures of the isobutanol and 2-methylcyclohexanol were reported experimentally in a certain range of concentrations at... 相似文献
105.
Safari Nasimeh Imanzadeh Gholamhassan Asgharzadeh Roghayyeh Hosseyni Seyyedeh Tahereh Shamkhali Amir Nasser Soltanzadeh Zahra 《Chemistry of Heterocyclic Compounds》2021,57(6):640-645
Chemistry of Heterocyclic Compounds - In this work, new pyrazole derivatives were prepared by one-pot three-component reaction emloying symmetric and asymmetric 1,2-disulfonyl-hydrazines,... 相似文献
106.
Abdolahi Sahar Hajjami Maryam Gholamian Fatemeh 《Research on Chemical Intermediates》2021,47(5):1883-1904
Research on Chemical Intermediates - The aim of present investigation is the synthesis of mesoporous catalyst based on hexagonal mesoporous silica. HMS support has exceptional properties such as... 相似文献
107.
108.
The behaviour of a dislocation pileup with a finite-strength source is investigated in the presence of various stress gradients within a continuum model where a free-dislocation region exists around the source. Expressions for dislocation density and stress field within the pileup are derived for the situation where there are first and second spatial gradients in applied stress. For a pileup configuration under an applied stress, yielding occurs when the force acting on the leading dislocations at the pileup tips reaches the obstacle strength, and at the same time, it is required that the source be at the threshold stress for dislocation production. A numerical methodology is presented to solve the underlying equations that represent the yielding conditions. The yield stress calculated for a pileup configuration is found to depend on stress gradients, obstacle spacing and source/obstacle strengths. It increases with increasing the first stress gradient, yet dependent on the second stress gradient. Furthermore, while the dependency of yield stress on the obstacle spacing intensifies with increasing the first stress gradient, it diminishes with an increase of second stress gradient. Therefore, the second stress gradient, as a newly introduced parameter, can provide a new physical insight into the size-dependent plasticity phenomena at small length scales. 相似文献
109.
Jaber Javidi Mohsen Esmaeilpour Zahra Rahiminezhad Fatemeh Nowroozi Dodeji 《Journal of Cluster Science》2014,25(6):1511-1524
In this study H3PW12O40·9H2O and H3PMo12O40·6H2O (HPA) particles were changed into nano forms by heat-treatment in an autoclave as a simple, repaid, inexpensive and one step method. The particle size of these nanoparticles was around 25 nm. The as-synthesized nanostructures were characterized by dynamic light scattering, X-ray powder diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy and inductively coupled plasma analyzer. Thermal stability of nanoparticles was surveyed by thermal gravimeter analyse. Acidity of prepared nanoparticles was investigated by pyridine adsorption method. Results showed rising acidity by declining particle size of HPA. 相似文献
110.
The hydrogen bond strength, molecular geometry, π-electron delocalization, and physical properties such as dipole moment, chemical potential, and chemical hardness of 4-nitropyridine-3-thiol and its 29 derivatives have been studied by means of density functional method with 6-311++G** basis set in gas phase and water solution. Also, the excited-state properties of intramolecular hydrogen bonding in these systems have been investigated theoretically using the time-dependent density functional theory method. The HOMA, NICS, PDI, ATI, FLU, and FLUπ indices as well-established aromaticity indicators have been examined. Natural bond orbital analysis is also performed for better understanding the nature of intramolecular interactions. The electron density and Laplacian (?2 ρ) properties, estimated by AIM calculations, indicate that H···O bond possesses low ρ and positive ?2 ρ values, which are in agreement with electrostatic character of the HBs, whereas S–H bond has covalent character. Numerous correlations between topological, geometrical, and energetic parameters are also found. 相似文献