Electrospun Structural Hybrids of Acyclovir-Polyacrylonitrile at Acyclovir for Modifying Drug Release

In traditional pharmaceutics, drug–crystalline nanoparticles and drug–polymer composites are frequently explored for their ability to modify drug release profiles. In this study, a novel sort of hybrid with a coating of acyclovir crystalline nanoparticles on acyclovir-polyacrylonitrile composites was fabricated using modified, coaxial electrospinning processes. The developed acyclovir-polyacrylonitrile at the acyclovir nanohybrids was loaded with various amounts of acyclovir, which could be realized simply by adjusting the sheath fluid flow rates. Compared with the electrospun composite nanofibers from a single-fluid blending process, the nanohybrids showed advantages of modifying the acyclovir release profiles in the following aspects: (1) the initial release amount was more accurately and intentionally controlled; (2) the later sustained release was nearer to a zero-order kinetic process; and (3) the release amounts at different stages could be easily allocated by the sheath fluid flow rate. X-ray diffraction results verified that the acyclovir nanoparticles were in a crystalline state, and Fourier-transform infrared spectra verified that the drug acyclovir and the polymer polyacrylonitrile had a good compatibility. The protocols reported here could pave the way for developing new types of functional nanostructures.

Fabrication of Millable Polyurethane Elastomer/Eucommia Ulmoides Rubber Composites with Superior Sound Absorption Performance

Sound absorbing materials combining millable polyurethane elastomer (MPU) and eucommia ulmoides rubber (EUG) were successfully fabricated via a physical blending process of EUG and MPU. The microstructure, crystallization performances, damping, mechanical and sound absorption properties of the prepared MPU/EUG composites were investigated systematically. The microstructure surface of various MPU/EUG composites became rough and cracked by the gradual incorporation of EUG, resulting in a deteriorated compatibility between EUG and MPU. With the increase of EUG content, the storage modulus (E’) of various MPU/EUG composites increased in a temperature range of −50 °C to 40 °C and their loss factor (tanδ) decreased significantly, including a reduction of the tanδ of MPU/EUG (70/30) composites from 0.79 to 0.64. Specifically, the addition of EUG sharply improved the sound absorption performances of various MPU/EUG composites in a frequency range of 4.5 kHz–8 kHz. Compared with that of pure MPU, the sound absorption coefficient of the MPU/EUG (70/30) composite increased 52.2% at a pressure of 0.1 MPa and 16.8% at a pressure of 4 MPa, indicating its outstanding sound absorption properties.

Machine learning assisted optimization of blending process of polyphenylene sulfide with elastomer using high speed twin screw extruder

Random forest regression was applied to optimize the melt-blending process of polyphenylene sulfide (PPS) with poly(ethylene-glycidyl methacrylate-methyl acrylate) (E-GMA-MA) elastomer to improve the Charpy impact strength. A training dataset was constructed using four elastomers with different GMA and MA contents by varying the elastomer content up to 20 wt% and the screw rotation speed of the extruder up to 5000 rpm at a fixed barrel temperature of 300 °C. Besides the controlled parameters, the following measured parameters were incorporated into the descriptors for the regression: motor torque, polymer pressure, and polymer temperatures monitored by infrared-ray thermometers installed at four positions (T1 to T4) as well as the melt viscosity and elastomer particle diameter of the product. The regression without prior knowledge revealed that the polymer temperature T1 just after the first kneading block is an important parameter next to the elastomer content. High impact strength required high elastomer content and T1 below 320 °C. The polymer temperature T1 was much higher than the barrel temperature and increased with the screw speed due to the heat of shear. The overheating caused thermal degradation, leading to a decrease in the melt viscosity and an increase in the particle diameter at high screw speed. We thus reduced the barrel temperature to keep T1 around 310 °C. This increased the impact strength from 58.6 kJ m−2 as the maximum in the training dataset to 65.3 and 69.0 kJ m−2 at elastomer contents of 20 and 30 wt%, respectively.

Specificity and Origin of the Stability of the Sr Isotopic Ratio in Champagne Wines

The 87Sr/86Sr ratio of 39 Champagnes from six different brands, originating from the whole “Appellation d’Origine Contrôlée” (AOC) Champagne was analyzed to establish a possible relation with the geographical origin. Musts (i.e., grape juice) and base wines were also analyzed to study the evolution of the Sr isotopic ratio during the elaboration process of sparkling wine. The results demonstrate that there is a very homogeneous Sr isotopic ratio (87Sr/86Sr = 0.70812, n = 37) and a narrow span of variability (2σ = 0.00007, n = 37). Moreover, the Sr concentrations in Champagnes have also low variability, which can be in part explained by the homogeneity of the bedrock in the AOC Champagne. Measurements of the 87Sr/86Sr ratio from musts and base wines show that blending during Champagne production plays a major role in the limited variability observed. Further, the 87Sr/86Sr of the musts were closely linked to the 87Sr/86Sr ratio of the vineyard soil. It appears that the 87Sr/86Sr of the product does not change during the elaboration process, but its variability decreases throughout the process due to blending. Both the homogeneity of the soil composition in the Champagne AOC and the blending process during the wine making process with several blending steps at different stages account for the unique and stable Sr isotopic signature of the Champagne wines.

Viscoelastic behaviour of highly filled polypropylene with solid and liquid Tin microparticles: influence of the stearic acid additive

In this work, highly filled composites made of a commercial polypropylene resin and low melting point Tin particles, up to 50 vol.% in loadings, have been prepared by melt blending process. The introduction of stearic acid (SA), a common dispersant, was investigated in compositions. The developed systems were characterized in terms of dynamic rheological testing. Final results confirmed a reduction of linear viscoelastic domain, by increasing filler loadings, with an effect more emphasized in the presence of SA. Contrary to literature studies, at equal filler content (50%), both moduli resulted to be superior for formulations containing the dispersing agent. A further rheological characterization continued on systems at 30 vol.% of particle loadings for highlighting differences depending on the SA addition. Specific tests were also performed at temperatures above the melting of Tin particles. Finally, optical microscopic analyses were carried out for gaining insight on sample microstructure, in controlled conditions of temperature and shear rate.

Simulation of sliver blending and evaluation of blending irregularity

The quality of blended yarn depends on the uniformity of the blending of the multi-component fibers in the yarn, and sliver blending is a process necessary for mixing fibers. The movement of fibers directly affects the distribution and mixing of fibers in the sliver. In this paper, the sliver blending process was simulated, and a method for the evaluation of sliver blending irregularity was proposed. The effects of passages of drawing and blending ratio on the sliver mixing uniformity were studied and verified both by experiment and simulation. The results show that the blending irregularity decreases gradually and tends to be stable with the increase of the passages of blending drawing. The more similar the blending ratio of the two components with approximately equal linear densities, the easier it is for the component fibers to mix evenly in the sliver. The simulation results are in good agreement with the measured values and previous research results. In addition, the blending irregularity of fiber components in the blended sliver can be predicted by the simulation method.

Study on the Interaction of the Sinicization of Christianity and the Reconstruction of Cross-border Ethnic Minorities Cultures in Yunnan

"I'm Sinicization of Christianity? which is the developing strategy and practice to make Christianity adapt to Chinese culture. It corresponds to the Christianization of Chinese ethnic minority people who believed in Christianity. From the perspective of cultural interaction, borrowing and blending, the study explores the motivation, process and characteristics of the interactive development between the localization and contextualization of Christianity in Yunnan ethnic minorities ' areas and the Christianization of ethnic minorities' cultures by historical com bi ng and synchronic comparison. Mostly between Christianity and ethnic minorities' traditional cultures had experienced from the estrangement, and coexisted with each other and blending process > and finished the Christian from "in" to the transition of “again”, so as to realize the Sinicizational characteristics of the regional > national > but also make the border ethnic cultural reconstruct.

Effect of Sago Starch Modifications on Polystyrene/Thermoplastic Starch Blends

The preparation of polystyrene/thermoplastic starch (PS/TPS) blends was divided into three stages. The first stage involved the preparation of TPS from sago starch. Then, for the second stage, PS was blended with TPS to produce a TPS/PS blend. The ratios of the TPS/PS blend were 20:80, 40:60, 60:40, and 80:20. The final stage was a modification of the composition of TPS/PS blends with succinic anhydride and ascorbic acid treatment. Both untreated and treated blends were characterized by their physical, thermal, and surface morphology properties. The obtained results indicate that modified blends have better tensile strength as the adhesion between TPS and PS was improved. This can be observed from SEM micrographs, as modified blends with succinic anhydride and ascorbic acid had smaller TPS dispersion in PS/TPS blends. The micrograph showed that there was no agglomeration and void formation in the TPS/PS blending process. Furthermore, modified blends show better thermal stability, as proved by thermogravimetric analysis. Water uptake into the TPS/PS blends also decreased after the modifications, and the structural analysis showed the formation of a new peak after the modification process.

A Series of Frequency Shift Antennas Based on Shape Blending

In this paper, an automatic antenna design method based on the shape blending algorithm is proposed. The algorithm is used to construct the shape of the wide slot of a CPW-fed antenna. Firstly, two basic shapes are chosen as the initial shape and the target shape. The shape blending process is then applied on them to get a series of shapes, which are used as the geometry structure of the wide slot. In this way, a series of CPW-fed wide slot antennas are obtained. And they have similar but gradually changing characteristics. The bandwidth ranges are 8.00–9.24 GHz, 7.95–9.05 GHz, 7.05–8.55 GHz, 6.95–8.13 GHz, and 6.55–7.50 GHz, respectively. The overall size of the antenna is 26 mm ∗ 20 mm ∗ 0.6 mm. Experimental results show that the resonant frequencies vary (via translation) with the change of slot shape in a specific frequency band. The experiments also validate that the antennas have omnidirectional radiation characteristics. The radiation gains and aperture efficiencies of the antennas are about 3.8–5.5 dBi and 57.7–83.0% at their centre frequencies, respectively. The experiment results show that the proposed antennas could be used in C-band and X-band radar applications.

Preparation of Long Sisal Fiber-Reinforced Polylactic Acid Biocomposites with Highly Improved Mechanical Performance

Green biodegradable plastics have come into focus as an alternative to restricted plastic products. In this paper, continuous long sisal fiber (SF)/polylactic acid (PLA) premixes were prepared by an extrusion-rolling blending process, and then unidirectional continuous long sisal fiber-reinforced PLA composites (LSFCs) were prepared by compression molding to explore the effect of long fiber on the mechanical properties of sisal fiber-reinforced composites. As a comparison, random short sisal fiber-reinforced PLA composites (SSFCs) were prepared by open milling and molding. The experimental results show that continuous long sisal fiber/PLA premixes could be successfully obtained from this pre-blending process. It was found that the presence of long sisal fibers could greatly improve the tensile strength of LSFC material along the fiber extension direction and slightly increase its tensile elongation. Continuous long fibers in LSFCs could greatly participate in supporting the load applied to the composite material. However, when comparing the mechanical properties of the two composite materials, the poor compatibility between the fiber and the matrix made fiber’s reinforcement effect not well reflected in SSFCs. Similarly, the flexural performance and impact performance of LSFCs had been improved considerably versus SSFCs.