Study of noise and structural characteristics of twin-screw air compressor based on multi-physical field coupling.

For the problems of high noise and low efficiency of twin-screw air compressor, the mutual coupling effect of noise and structure for the twin-screw air compressor is studied by using acoustic-solid coupling technology. The simulation model of acoustic-structural coupling of twin-screw air compressor is established. Combining acoustic wave theory calculation with structural characteristics, the sound pressure level distribution and structural deformation law of different tangent planes of the shell at different frequencies under external excitation are studied. The results show that when the frequency is different, the more intensive the acceleration distribution on the shell surface is, the greater the sound pressure level is. At the same frequency, as the incident pressure wave increases, the deformation on the shell also increases, and the maximum shell deformation and the maximum sound pressure level both appear around 2000 Hz. As the frequency increases, the acceleration distribution on the surface of the shell becomes more denser and the sound pressure level becomes larger.

Development of Novel Paclitaxel-Loaded ZIF-8 Metal-Organic Framework Nanoparticles Modified with Peptide Dimers and an Evaluation of Its Inhibitory Effect against Prostate Cancer Cells.

Prostate cancer (PC) is one of the common malignant tumors of the male genitourinary system. Here, we constructed PTX@ZIF-8, which is a metal-organic-framework-encapsulated drug delivery nanoparticle with paclitaxel (PTX) as a model drug, and further modified the synthesized peptide dimer (Di-PEG2000-COOH) onto the surface of PTX@ZIF-8 to prepare a nanotargeted drug delivery system (Di-PEG@PTX@ZIF-8) for the treatment of prostate cancer. This study investigated the morphology, particle size distribution, zeta potential, drug loading, encapsulation rate, stability, in vitro release behavior, and cytotoxicity of this targeted drug delivery system, and explored the uptake of Di-PEG@PTX@ZIF-8 by human prostate cancer Lncap cells at the in vitro cellular level, as well as the proliferation inhibition and promotion of apoptosis of Lncap cells by the composite nanoparticles. The results suggest that Di-PEG@PTX@ZIF-8, as a zeolitic imidazolate frameworks-8-loaded paclitaxel nanoparticle, has promising potential for the treatment of prostate cancer, which may provide a novel strategy for the delivery system targeting prostate cancer.

Research Advances in Nucleic Acid Delivery System for Rheumatoid Arthritis Therapy.

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that affects the lives of nearly 1% of the total population worldwide. With the understanding of RA, more and more therapeutic drugs have been developed. However, lots of them possess severe side effects, and gene therapy may be a potential method for RA treatment. A nanoparticle delivery system is vital for gene therapy, as it can keep the nucleic acids stable and enhance the efficiency of transfection in vivo. With the development of materials science, pharmaceutics and pathology, more novel nanomaterials and intelligent strategies are applied to better and safer gene therapy for RA. In this review, we first summarized the existing nanomaterials and active targeting ligands used for RA gene therapy. Then, we introduced various gene delivery systems for RA treatment, which may enlighten the relevant research in the future.

Syntheses, characterization and properties of three coordination polymers with interpenetrating structures comprising 4,4'-(1H-1,2,4-triazol-1-yl)methylene-bis(benzonic acid).

Three new coordination polymers (CPs), {[Pb(tmdb)](H2O)} n (1), {[Zn(tmdb)(bimb)0.5]} n (2) and {[Zn3(tmdb)3(bpmb)1.5](H2O)6} n (3) (H2tmdb = 4,4'-(1H-1,2,4-triazol-1-yl)methylene-bis(benzonic acid), where bpmb = 1,4-bis(pyridin-4-ylmethoxy)benzene and bimb = 1,4-bis(imidazoly-1-yl)benzene), have been solvothermally or hydrothermally synthesized. Compound 1 is a 2D network with the point symbol (4·6·8)(4·62) and compound 2 is a 4-fold interpenetrating 3D network with spiral chains. The topological type of 2 is dmc (topos&RCSR.ttd) with the point symbol (4·82)(4·85). Compound 3 is a 3-fold interpenetrating 3D network with the point symbol (63)2(8·65)2(10·62)(8·10·64). The electrochemiluminescence (ECL) behaviors of 2 and 3 were studied. The applications of CP 2 and 3 in detecting ions were explored, and the results show that they can be used as fluorescent probes to selectively detect and identify Fe3+ ions in water. In addition, the applications of CP 2 and 3 in the adsorption and separation of dyes were researched. Furthermore, the gas adsorption of 3 was studied.