This study focused on the formulation and characterization of silver nanoparticles (AgNP) functionalized with d-limonene. The nanoparticles were functionalized by phase inversion and the synthesis of the nanoparticles was performed in situ; particle size was determined by laser diffraction, zeta potential and optical colloidal stability using Multiscan 20 for a period of 24 hours at 37 °C; the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the formulated material on Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 29213, Klebsiella oxytoca ATCC 700324, Enterococcus casseliflavus ATCC 700327, Escherichia coli BLEE, carbapenem-resistant Pseudomona aeruginosa were determined. The nanoparticles showed colloidal stability at a d-limonene concentration of 3.93%, silver ions at 1.61 × 10−3%, non-ionic adjuvant at 24% and ascorbic acid at 5.88%; citric acid/citrate (1:1) 0.48M for a pH of 4.5 was used as a buffer system. The formulation was classified as a polydisperse system (PD = 0.0851), with a zeta potential of −11.6 mV and average particle size of 81.5 ± 0.9 nm. A particle migration velocity of −0.199 ± 0.006 mm∙h−1, a constant transmission profile and backscattering profile with variations of 10% were evidenced, which represents a stable formulation. The nanoparticles presented an MIC and an MBC of 28 μg∙mL−1 (5.6 × 10−2% d-limonene and 4.7 × 10−5% AgNP) against all tested bacteria.
Influenced by global financial crisis in 2008, many countries around the world have realized the significance of sustainable development. And green development, as the most important pathway to sustainability, has been implemented by various countries. In this context, green development has drawn great attention from academic researchers both at home and abroad in recent years and has become an interdisciplinary-oriented research direction. As an applied basic research field for exploring the structural change of resources and environment as well as regional sustainable development, geography plays an essential role in the research of green development. Based on an intensive literature review, this article firstly summarized the connotation and analytical framework of green development. Secondly, it systematically outlined the progress of green development research from the perspective of geography and thus extracted seven themes, that is, the influencing factors of green development, assessment methods, spatial and temporal characteristics of green development, green development and industrial transformation, green transformation of resource-based cities, the effect of green development, and green development institutions and recommendations. Comments were made on the existing studies including their shortcomings. Finally, future research emphases were discussed, aiming to provide references for further study on green development from the perspective of geography in China.
Using matricant method elastic moduli of occasionally heterogeneous isotropic and anisotropic elastic media were received. Anisotropic behaviour and conditions for change in anisotropy of media associated with averaging of one-dimensional periodic structures was determined.
With the development of material life, the importance of plants in life has become increasingly prominent, and indoor flowers are also popular. As we all know, plants have purified air, refreshing brainwashing, promote sleep, sterilization and other effects, such as mint, Clivia, aloe and so on. Therefore, the choice of plants corresponding to their own needs is particularly important, while to note that some flowers should not be placed indoors. And different flowers on the water, temperature, light, soil and other requirements are not the same.
Based on the analysis of the development and present situation of the standardization of forest cultivation in China and combined with the characteristics of forest cultivation, the main basis, principles and methods of establishing forest cultivation standard system were discussed and put forward. A standard system of forest cultivation was established, which included six sub-systems, namely, forest cultivation foundation, prenatal planning, artificial afforestation, tending management, harvest renewal etc. The ideas and management suggestions for standardization of forest cultivation in China in the future were put forward, such as to establish an authoritative and complete database and a supporting management system.
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