The principal components analysis in kiwifruit (latent value and cumulative contribution).

<p>The principal components analysis in kiwifruit (latent value and cumulative contribution).</p

Chilling injury symptoms of ‘Hongyang’ kiwifruit.

<p>Representative pictures of ‘Hongyang’ kiwifruit after 90 days of cold storage followed by 5 days of shelf life at 20°C. (A) normal kiwifruit. (B) skin showing the brown symptom of CI (arrow). (C) normal flesh of kiwifruit. (D) flesh of kiwifruit showing the grainy symptom (arrow). (E) the cross-section of the normal flesh. (F) the cross-section of the flesh showing the grainy symptom (arrow). (G)the longitudinal section of the normal flesh. (H) the longitudinal section of the flesh showing the grainy symptom (arrow).</p

Effect of exogenous Put treatment on ethylene production rate of ‘Hongyang’ fruit.

<p>Kiwifruit were respectively immersed in 0 mM (control) and 2 mM putrescine (Put) for 10 min and then storage at 0°C and 90–95% relative humidity for 90 days. In storage time ‘+5’ denotes 5 days of shelf life at 20°C following storage at 0°C. Vertical bars represent standard error of means (n = 3). Asterisks show significant difference (<i>P <0</i>.<i>05</i>) for the samples between 2 mM Put treatment and control taken at the same time point.</p

Loading of principal components.

<p>Loading of principal components.</p

Effects of exogenous Put treatment on firmness, SSC, and titratable acidity of ‘Hongyang’ kiwifruit during storage at 0°C.

<p>Effects of exogenous Put treatment on firmness, SSC, and titratable acidity of ‘Hongyang’ kiwifruit during storage at 0°C.</p

Deformation Hysteresis of Electrohydrodynamic Patterning on a Thin Polymer Film

Electrohydrodynamic patterning is a technique that enables micro/nanostructures via imposing an external voltage on thin polymer films. In this investigation, we studied the electrohydrodynamic patterning theoretically and experimentally, with special interest focused on the equilibrium state. It is found that the equilibrium structure height increases with the voltage. In addition, we have observed, and believe it to be the first time, a hysteresis phenomenon exists in the relationship between the voltage and structure height. With an increase in the voltage, a critical value (the first critical voltage) is noticed, above which the polymer film would increase dramatically until it comes into contact with the template. However, with a decrease in the voltage, a smaller voltage (the second critical voltage) is needed to detach the polymer from the template. The mismatch of the first and second critical voltages distorts the voltage–structure height curve into an “S” shape. Such a phenomenon is verified for three representative templates and also by experiments. Furthermore, the effects of some parameters (e.g., polymer film thickness and dielectric constant) on this hysteresis phenomenon are also discussed

Bioprinting-Based PDLSC-ECM Screening for in Vivo Repair of Alveolar Bone Defect Using Cell-Laden, Injectable and Photocrosslinkable Hydrogels

Periodontitis is an inflammatory disease worldwide that may result in periodontal defect (especially alveolar bone defect) and even tooth loss. Stem-cell-based approach combined with injectable hydrogels has been proposed as a promising strategy in periodontal treatments. Stem cells fate closely depends on their extracellular matrix (ECM) characteristics. Hence, it is necessary to engineer an appropriate injectable hydrogel to deliver stem cells into the defect while serving as the ECM during healing. Therefore, stem cell-ECM interaction should be studied for better stem cell transplantation. In this study, we developed a bioprinting-based strategy to study stem cell–ECM interaction and thus screen an appropriate ECM for in vivo repair of alveolar bone defect. Periodontal ligament stem cells (PDLSCs) were encapsulated in injectable, photocrosslinkable composite hydrogels composed of gelatin methacrylate (GelMA) and poly­(ethylene glycol) dimethacrylate (PEGDA). PDLSC-laden GelMA/PEGDA hydrogels with varying composition were efficiently fabricated via a 3D bioprinting platform by controlling the volume ratio of GelMA-to-PEGDA. PDLSC behavior and fate were found to be closely related to the engineered ECM composition. The 4/1 GelMA/PEGDA composite hydrogel was selected since the best performance in osteogenic differentiation in vitro. Finally, in vivo study indicated a maximal and robust new bone formation in the defects treated with the PDLSC-laden hydrogel with optimized composition as compared to the hydrogel alone and the saline ones. The developed approach would be useful for studying cell–ECM interaction in 3D and paving the way for regeneration of functional tissue

Fabrication of Microscale Hydrogels with Tailored Microstructures based on Liquid Bridge Phenomenon

Microscale hydrogels (microgels) find widespread applications in various fields, such as drug delivery, tissue engineering, and biosensing. The shape of the microgels is a critical parameter that can significantly influence their function in these applications. Although various methods have been developed (e.g., micromolding, photolithography, microfluidics, and mechanical deformation method), it is still technically challenging to fabricate microgels with tailored microstructures. In this study, we have developed a simple and versatile method for preparing microgels by stretching hydrogel precursor droplets between two substrates to form a liquid bridge. Microgels with tailored microstructures (e.g., barrel-like, dumbbell-like, or funnel-like shapes) have been achieved through adjusting the distance between and the hydrophobicity of the two substrates. The developed method holds great potential to impact multiple fields, such as drug delivery, tissue engineering, and biosensing