Characterization of a hierarchical network of hyaluronic acid/gelatin composite for use as a smart injectable biomaterial

Hybrid HA/Ge hydrogel particles are embedded in a secondary HA network to improve their structural integrity. The internal microstructure of the particles is imaged through TEM. CSLM is used to identify the location of the Ge molecules in the microgels. Through indentation tests, the Young's modulus of the individual particles is found to be 22 ± 2.5 kPa. The overall shear modulus of the composite is 75 ± 15 Pa at 1 Hz. The mechanical properties of the substrate are found to be viable for cell adhesion. The particles' diameter at pH = 8 is twice that at pH = 5. The pH sensitivity is found to be appropriate for smart drug delivery. Based on their mechanical and structural properties, HA-Ge hierarchical materials may be well suited for use as injectable biomaterials for tissue reconstruction.     

Phytochemical analysis and Enzyme Inhibition Assay of Aerva javanica for Ulcer

Background

Nickel ferrite, a kind of soft magnetic materials is one of the most attracting class of materials due to its interesting and important properties and has many technical applications, such as in catalysis, sensors and so on. In this paper the synthesis of NiFe₂O₄ nanoparticles by the hydrothermal method is reported and the inhibition of surfactant (Glycerol or Sodium dodecyl sulfate) on the particles growth is investigated.

Methods

For investigation of the inhibition effect of surfactant on NiFe₂O₄ particles growth, the samples were prepared in presence of Glycerol and Sodium dodecyl sulfate. The X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), vibrating sample magnetometer (VSM) and inductively coupled plasma atomic emission spectrometer (ICP-AES) techniques were used to characterize the samples.

Results

The results of XRD and ICP-AES show that the products were pure NiFe₂O₄ and also nanoparticles grow with increasing the temperature, while surfactant prevents the particle growth under the same condition. The average particle size was determined from the Scherrer's equation and TEM micrographs and found to be in the range of 50-60 nm that decreased up to 10-15 nm in presence of surfactant. The FT-IR results show two absorption bands near to 603 and 490 cm^-1 for the tetrahedral and octahedral sites respectively. Furthermore, the saturated magnetization and coercivity of NiFe₂O₄ nanoparticles were in the range of 39.60 emu/g and 15.67 Q_e that decreased for samples prepared in presence of surfactant. As well as, the nanoparticles exhibited a superparamagnetic behavior at room temperature.

Conclusions

Nanosized nickel ferrite particles were synthesized with and without surfactant assisted hydrothermal methods. The results show that with increasing of temperature, the crystallinity of nanoparticles is increased. In the presence of surfactants, the crystallinity of NiFe₂O₄ nanoparticles decreased in comparison with surfactant- free prepared samples. All of the nickel ferrite nanoparticles were superparamagnetic at room temperature.

Graphical abstract

     

Furoquinoline alkaloids from Melicope bonwickii (F.Muell.) T.Hartley

Investigation on the leaves of Melicope bonwickii (F.Muell.) T.Hartley (Rutaceae) afforded a new 7-(2'-hydroxy-3'-chloroprenyloxy)-4-methoxyfuroquinoline (1) together with the known 7-(2',3'-epoxyprenyloxy)-4-methoxyfuroquinoline (2), evellerine (3) kokusaginine (4) and an amide aurantiamide acetate (5). Compounds 1 and 2 showed significant activity against cervical cell lines (Hela).     

Fixed Point Tehorems in Fuzzy Inner Product Spaces

In this paper, we obtain some new fixed point theorems in fuzzy-Banach spaces by considering the t-norms of h-type and a linear mapping of weakly demicompact.     

Optimization of an efficient semi-solid culture protocol for sterilization and plant regeneration of Centella asiatica (L.) as a medicinal herb

The present study investigates the effects of different concentrations, as well as type of plant growth regulators (PGRs) and medium (MS, Duchefa) on the growth and development of Centella asiatica in semi-solid culture. In addition, a protocol for successful sterilization of C.asiatica explants prepared from field-grown plants highly exposed to fungal and bacterial contamination was determined. Results for sterilization treatments revealed that applying HgCl? and Plant Preservative Mixture (PPM) with cetrimide, bavistin and trimethoprim which were included after washing with tap water, followed by the addition of PPM in the medium, produced a very satisfactory result (clean culture 90 ± 1.33%) and TS5 (decon + cetrimide 1% + bavistin 150 mg/L + trimethoprim 50 mg/L + HgCl?0.1% + PPM 2% soak and 2 mL/L in medium) was hence chosen as the best method of sterilization for C.asiatica. The synergistic combination of 6 benzylaminopurine (BAP) and 1-naphthaleneacetic acid (NAA) in concentrations of 2 mg/L and 0.1 mg/L, respectively, in Duchefa medium compared with MS induced the most optimal percentage of sprouted shoots (93 ± 0.667), number of shoots (5.2 ± 0.079) and nodes (4 ± 0.067) per explant, leaf per explant (14 ± 0.107) and shoot length (4.1 ± 0.67 cm). Furthermore, optimum rooting frequency (95.2 ± 0.81%), the number of roots/shoot (7.5 ± 0.107) and the mean root length (4.5 ± 0.133 cm) occurred for shoots that were cultured on full-strength MS medium containing 0.5 mg/L indole-3-butyric acid (IBA). In this study, the acclimatized plantlets were successfully established with almost 85% survival. The findings of this study have proven an efficient medium and PGR concentration for the mass propagation of C.asiatica. These findings would be useful in micropropagation and ex situ conservation of this plant.     

Thermal management

Journal of Thermal Analysis and Calorimetry -     

Hall Effect on Falkner-Skan Boundary Layer Flow of FENE-P Fluid over a Stretching Sheet

The Falkner-Skan boundary layer steady flow over a flat stretching sheet is investigated in this paper. The mathematical model consists of continuity and the momentum equations, while a new model is proposed for MHD Finitely Extensible Nonlinear Elastic Peterlin (FENE-P) fluid. The effects of Hall current with the variation of intensity of non-zero pressure gradient are taken into account. The governing partial differential equations are first transformed to ordinary differential equations using appropriate similarity transformation and then solved by Adomian decomposition method (ADM). The obtained results are validated by generalized collocation method (GCM) and found to be in good agreement. Effects of pertinent parameters are discussed through graphs and tables. Comparison with the existing studies is made as a limiting case of the considered problem at the end.     

Synthesis and properties of a soluble and widely conjugated polyacetylene with anthryl pendant

The metathesis polymerization of an anthrylacetylene bearing an alkyl ester group, 9‐(10‐hexoxycarbonyl)anthrylacetylene ( 1 ), was conducted with various transition‐metal catalysts. A completely soluble black polymer was obtained from 1 in a good yield when W‐based catalysts were employed. The polymerization at a high monomer concentration (1 M) and a high temperature (80 °C) led to the formation of poly( 1 ) with a weight‐average molecular weight of 297 × 10³ in an 80% yield. The use of cocatalysts unexpectedly decreased both the yield and molecular weight of poly( 1 ). Rh‐catalyzed and Mo‐catalyzed polymerizations, however, resulted in poor yields of the polymer. The ultraviolet–visible spectrum of poly( 1 ) showed a significantly redshifted absorption (λ_max = 571) with a cutoff at 780 nm, which verified the very high order of conjugation of the main chain. Poly( 1 ) exhibited the largest third‐order nonlinear optical susceptibility [χ⁽³⁾ (−ω; ω, 0, 0) = − 1.9 × 10⁻¹⁰ esu] among the polymers from the monosubstituted polyacetylenes synthesized so far. The electrical conductivity of poly( 1 ) in an I₂‐doped state was 8.77 × 10⁻⁴ at 293 K. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4717–4723, 2000