Numerical analysis of impingement characteristics of supercooled large droplets on the surface of a rotating hood

The authors of this study numerically analyze the characteristics of impingement of supercooled large droplets on the surface of the rotating hood of an aircraft. We use the secondary development function of Fluent software to first compare the prevalent models of impinging supercooled large droplets and then develop a modified model to numerically simulate their characteristics of impingement on the surface of a rotating hood in order to examine the effects of the diameter of the droplets, the speed of rotation, and the corresponding velocity of inflow on them. The results showed that the efficiency of the loss of mass of the droplets caused by their splashing and rebounding was low on the top of the cone, while the efficiency of local droplet collection was the highest. The efficiency of mass loss quickly increased, while that of droplet collection sharply decreased in the area of transition from the top to the side. The efficiencies of mass loss and droplet collection were nearly constant on the side of the cone, while that of the latter decreased to zero on the tail of the cone. When the median volumetric diameter of the droplets was increased from 79 to 250 µm, the efficiency of the loss of mass increased by about 15% on the side of the cone, but that of local droplet collection changed only slightly. The efficiency of the loss of mass decreased by about 20%, while that of local droplet collection increased by about 2.6% on the top of the cone under this condition. When the speed of rotation was increased from 1200 to 4300 r/min and the corresponding velocity of inflow was increased from 30 to 140 m/s, the efficiency of mass loss increased by about 15% on the side of the cone, while that of local droplet collection changed little. The efficiency of mass loss on the top of the cone decreased by about 37.5%, while that of local droplet collection increased by about 8% in this case

Bioactive zwitterionic polymer brushes grafted from silicon wafers via SI-ATRP for enhancement of antifouling properties and endothelial cell selectivity

<p>Zwitterionic copolymers keep good resistance to platelet adhesion and nonspecific protein adsorption. In this study, A block copolymer brushes consisting of carboxybetaine methacrylate (CBMA) and glycidyl methacrylate (GMA) were grafted from silicon wafers via surface-initiated atom transfer radical polymerization, and then the Arg-Glu-Asp-Val (REDV) peptide was attached to the polymer brush via an reactive epoxy group of the P(GMA) unit to improve endothelial cells (ECs) selectivity. These modified surfaces were evaluated with scanning electron microscopy, atomic force microscopy, attenuated total reflectance-Fourier transform infrared spectra, X-ray photoelectron spectroscopy, and static water contact angle measurement. The results showed that REDV-modified zwitterionic brushes were successfully constructed on silicon wafers. The biocompatibility of the membrane was determined by plasma recalcification time assay and platelet adhesion test. The results showed that the modified substrate exhibited good blood compatibility. Moreover, the proliferation of ECs and smooth muscle cells onto the REDV-modified copolymer brushes were examined to demonstrate the synergistic effect of CBMA with antifouling property and REDV peptide with ECs selectivity. All assays showed that the silicon wafers displayed excellent EC selectivity after modification. In summary, REDV-modified zwitterionic brushes had great potential for cardiovascular stent implantation.</p

Effects of ultrasound treatment on muscle structure, volatile compounds, and small molecule metabolites of salted Culter alburnus fish

This study investigated the effects of ultrasound treatment on the quality of salted Culter alburnus fish. The results showed that with the increasing ultrasound power, the structural degradation of muscle fibers was intensified, and the conformation of myofibrillar protein was significantly changed. The high-power ultrasound treatment group (300 W) had relatively higher thiobarbiturate reactive substance content (0.37 mg malondialdehyde eq/kg) and peroxidation value (0.63 mmol/kg). A total of 66 volatile compounds were identified with obvious differences among groups. The 200 W ultrasound group exhibited fewer fishy substances (Hexanal, 1-Pentene-3-ol, and 1-Octane-3-ol). Compared with control group, ultrasound groups (200, 300 W) contained more umami taste-related amino peptides such as γ-Glu-Met, γ-Glu-Ala, and Asn-pro. In the ultrasound treatment group, L-isoleucine and L-methionine, which may be used as flavor precursors, were significantly down-regulated, while carbohydrates and its metabolites were up-regulated. Amino acid, carbohydrate, and FA (fatty acyls) metabolism products in salted fish were enriched by ultrasound treatment, and those products might ultimately be related to the taste and flavor of salted fish

Discovery of Potent and Simplified Piperidinone-Based Inhibitors of the MDM2–p53 Interaction

Continued optimization of the N-substituent in the piperidinone series provided potent piperidinone–pyridine inhibitors <b>6</b>, <b>7</b>, <b>14</b>, and <b>15</b> with improved pharmacokinetic properties in rats. Reducing structure complexity of the <i>N</i>-alkyl substituent led to the discovery of <b>23</b>, a potent and simplified inhibitor of MDM2. Compound <b>23</b> exhibits excellent pharmacokinetic properties and substantial in vivo antitumor activity in the SJSA-1 osteosarcoma xenograft mouse model

Discovery of AM-7209, a Potent and Selective 4‑Amidobenzoic Acid Inhibitor of the MDM2–p53 Interaction

Structure-based rational design and extensive structure–activity relationship studies led to the discovery of AMG 232 (<b>1</b>), a potent piperidinone inhibitor of the MDM2–p53 association, which is currently being evaluated in human clinical trials for the treatment of cancer. Further modifications of <b>1</b>, including replacing the carboxylic acid with a 4-amidobenzoic acid, afforded AM-7209 (<b>25</b>), featuring improved potency (<i>K</i>_D from ITC competition was 38 pM, SJSA-1 EdU IC₅₀ = 1.6 nM), remarkable pharmacokinetic properties, and in vivo antitumor activity in both the SJSA-1 osteosarcoma xenograft model (ED₅₀ = 2.6 mg/kg QD) and the HCT-116 colorectal carcinoma xenograft model (ED₅₀ = 10 mg/kg QD). In addition, <b>25</b> possesses distinct mechanisms of elimination compared to <b>1</b>