6 research outputs found
The Superior Aspects of an Arc Downcomer Tray with Total Deflectors
A new structural tray Âľ the arc downcomer tray with total deflectors (ADTTD) was designed based on the numerical calculation of entropy generation rate. A pilot-scale setup was established to evaluate its hydrodynamics, heat transfer and mass transfer performances. The correlations for calculating the tray pressure drop and downcomer backup were derived. The measured temperature profiles of the liquid layer on the tray show that the flow pattern is nearly in an ideal mode if suitable deflectors are designed. The pressure drop of this tray decreases by approximately 50% compared with that of a conventional sieve tray in the region of intermediate to high vapor load. The liquid-phase Murphree tray efficiency of the tray is almost 30% higher than that of the traditional sieve tray under the same operating conditions. The weeping curve of the tray was also found to be a little lower than that of conventional trays. Experiments and industrial applications demonstrated that the ADTTD had some important advantages in lower pressure drop and energy-consumption, higher capacity and tray efficiency over the conventional sieve trays
Degradation Characteristics of Cellulose Acetate in Different Aqueous Conditions
Cellulose acetate (CA) is widely used in cigarette filters and packaging films, but due to its acetylation, it is difficult to degrade in the natural environment, and the problem of pollution has become a serious challenge. Understanding the degradation behavior and performance of CA in different environments is the basis and prerequisite for achieving its comprehensive utilization and developing efficient degradation methods. In this study, we investigated the degradation performance of CA in different aqueous environments to evaluate the effects of pH, salinity and microorganisms on CA degradation. The CA tows and films were immersed in HCl, NaOH solution, river water, seawater or homemade seawater for 16 weeks and the degradation mechanism was investigated by the changes in weight loss rate, degree of substitution, hydrophilicity, molecular structure and surface morphology. The results showed that the degradation of CA tow and film were the fastest in NaOH solution; the weight loss rates after 16 weeks were 40.29% and 39.63%, respectively, followed by HCl solution, and the degradation performance of CA tow was better than that of film. After 16 weeks of degradation in river water, seawater and homemade seawater, all the weight loss rates were less than 3%. In summary, this study illustrated that the environmental acidity, basicity and high concentration of inorganic salts had a critical promotion effect on the non-enzymatic hydrolysis of CA, whereas the number and type of microorganisms were the key factors affecting the biodegradation of CA
Dynamic Changes in Cell Wall Polysaccharides during Fruit Development and Ripening of Two Contrasting Loquat Cultivars and Associated Molecular Mechanisms
Loquats have drawn much attention due to their essential nutrients and unusual phenology, which fills a market gap in early spring. Fruit firmness (FF) is one of the most important quality attributes. Dynamic changes in FF, cell wall (CW) polysaccharides, CW hydrolase activity, and expression of CW metabolism-related genes during the fruit development and ripening stages of two contrasting loquat cultivars were compared. Although the two cultivars possessed similar FF at the initial fruitlet stage, Dawuxing was significantly firmer than Ninghaibai at all subsequent time points. FF was positively correlated with the contents of covalent-soluble pectin and hemicellulose, activity of peroxidase, and gene expressions of PME, EG, CAD6, and POD; and negatively correlated with the contents of water-soluble pectin, activities of polygalacturonase, endo-glucanase, cellobiohydrolase, and xylanase, and gene expressions of PG, EG2, PAL1, PAL3, and CAD5. Identifying molecular mechanisms underlying the differences in FF is useful for fundamental research and crop improvement in future
Structure-based drug discovery of novel fused-pyrazolone carboxamide derivatives as potent and selective AXL inhibitors
As a novel and promising antitumor target, AXL plays an important role in tumor growth, metastasis, immunosuppression and drug resistance of various malignancies, which has attracted extensive research interest in recent years. In this study, by employing the structure-based drug design and bioisosterism strategies, we designed and synthesized in total 54 novel AXL inhibitors featuring a fused-pyrazolone carboxamide scaffold, of which up to 20 compounds exhibited excellent AXL kinase and BaF3/TEL-AXL cell viability inhibitions. Notably, compound 59 showed a desirable AXL kinase inhibitory activity (IC50: 3.5 nmol/L) as well as good kinase selectivity, and it effectively blocked the cellular AXL signaling. In turn, compound 59 could potently inhibit BaF3/TEL-AXL cell viability (IC50: 1.5 nmol/L) and significantly suppress GAS6/AXL-mediated cancer cell invasion, migration and wound healing at the nanomolar level. More importantly, compound 59 oral administration showed good pharmacokinetic profile and in vivo antitumor efficiency, in which we observed significant AXL phosphorylation suppression, and its antitumor efficacy at 20 mg/kg (qd) was comparable to that of BGB324 at 50 mg/kg (bid), the most advanced AXL inhibitor. Taken together, this work provided a valuable lead compound as a potential AXL inhibitor for the further antitumor drug development
Design and Optimization of a Series of 1‑SulfonylÂpyrazolo[4,3‑<i>b</i>]pyridines as Selective c‑Met Inhibitors
c-Met
has emerged as an attractive target for targeted cancer therapy
because of its abnormal activation in many cancer cells. To identify
high potent and selective c-Met inhibitors, we started with profiling
the potency and in vitro metabolic stability of a reported hit <b>7</b>. By rational design, a novel sulfonylÂpyrazoloÂ[4,3-<i>b</i>]Âpyridine <b>9</b> with improved DMPK properties
was discovered. Further elaboration of π–π stacking
interactions and solvent accessible polar moieties led to a series
of highly potent and selective type I c-Met inhibitors. On the basis
of in vitro and in vivo pharmacological and pharmacokinetics studies,
compound <b>46</b> was selected as a preclinical candidate for
further anticancer drug development