3D Printing Properties of Heat-Induced Sodium Alginate-Whey Protein Isolate Edible Gel.

The objective of this study was to develop a food 3D printing gel and investigate the effects of whey protein isolate (WPI), sodium alginate (SA), and water-bath heating time on the 3D printing performance of the gel. Initially, the influence of these three factors on the rheological properties of the gel was examined to determine the suitable formulation ranges for 3D printing. Subsequently, the formulation was optimized using response surface methodology, and texture analysis, scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy were conducted. The rheological results indicated that gels with WPI concentrations of 6-7 g, SA concentrations of 0.8-1.2 g, and water-bath heating times of 10-12 min exhibited lower yield stress and better self-supporting properties. The optimized formulation, determined through response surface methodology, consisted of 1.2 g SA, 6.5 g WPI, and a heating time of 12 min. This optimized formulation demonstrated enhanced extrusion capability and superior printing performance. SEM analysis revealed that the optimized gel possessed good mechanical strength, and FTIR spectroscopy confirmed the successful composite formation of the gel. Overall, the results indicate that the optimized gel formulation can be successfully printed and exhibits excellent 3D printing performance.

Angiopoietin-like protein 4 treated bone marrow-derived mesenchymal stem cells alleviate myocardial injury of patients with myocardial infarction.

Bone marrow-derived mesenchymal stem cells (BMSCs) and their exosomes are of great significance for the recovery of cardiac function in patients with myocardial infarction (MI). However, the underlying mechanisms of BMSCs applied to MI treatment remain unclear. Fluorescence-activated cell sorting (FACs) are performed to assess the apoptosis, reactive oxygen species levels and glucose uptake capacity of BMSCs. Reverse transcription polymerase chain reaction is conducted to detect the levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), hepatocyte growth factor (HGF), insulin-like growth factor (IGF), transforming growth factor-beta 1, connective tissue growth factor, and platelet-derived growth factor. The levels of apoptosis-related proteins were detected by Western blot. The levels of VEGF, bFGF, HGF, and IGF were assessed by enzyme-linked immunosorbent assay. The biochemical kits are applied to detect the levels of malondialdehyde, superoxide dismutase, and adenosine triphosphate/adenosine diphosphate. 2,3,5-triphenyltetrazolium and Masson staining and immunofluorescence are performed to assess myocardial function of rats. Angiopoietin-like protein 4 (ANGPTL4) alleviates apoptosis and oxidative stress of BMSCs induced by serum deprivation and hypoxia; ANGPTL4 activates paracrine and accelerate metabolic energy of BMSCs; and ANGPTL4 treated-BMSCs alleviate myocardial injury of rats with MI. ANGPTL4 treated-BMSCs alleviate myocardial injury in rats with MI, indicating the combination therapy of ANGPTL4 and BMSCs may alleviate myocardial injury in rats with MI.

A study on dynamic volatile organic compound emission characterization of water-based paints.

Volatile organic compounds (VOCs) emitted from surface coatings have caused growing public concern for air quality. Even the low-emitted VOC impact from water-based paints on indoor air quality in urban areas has caused concern. This paper presents experimental data using a mathematical model to simulate dynamic VOC emissions from water-based paints that is based on mass transfer and molecular diffusion theories. A series of field-analogous experiments were carried out to continuously measure the VOCs emitted from two typical water-based paints using a gas chromatography-flame-ionization detector monitor in an artificial wind tunnel system. In the study cases, the mass flux of VOCs emitted from the water-based paints was up to 50 microg/m2sec. It was found that the time needed to completely emit VOCs from water-based paints is just hundreds of seconds. However, the order of magnitude of the VOC emission rate from water-based paints is not lower than that from some dry building materials and solvent-based paints. The experimental data were used to produce a useful semiempirical correlation to estimate the VOC emission rates for water-based paints. This correlation is valid under appropriate conditions as suggested by this work with a statistical deviation of +/- 7.6%. With this correlation, it seems feasible to predict the dynamic emission rates for VOCs during a painting process. This correlation is applicable for assessing the hazardous air pollutant impact on indoor air quality or for environmental risk assessment. Associated with the dynamic VOC emission characterization, the air-exchange rate effect on the VOC emission rates is also discussed.