Encapsulation of zingerone by self-assembling peptides derived from fish viscera: Characterization, interaction and effects on colon epithelial cells.

The purpose of the present work was to encapsulate zingerone (a bioactive compound from ginger) by self-assembling peptides derived from fish viscera. The encapsulation conditions were investigated and the structure of fish peptides-zingerone complex was characterized. The interaction between zingerone and fish peptides was investigated using fluorescence spectroscopy. Further research was performed on the in vitro release of zingerone and fish peptide-zingerone as well as their antiproliferative effects on colon epithelial Caco-2 cells. The results demonstrated that zingerone can be successfully encapsulated by self-assembling peptides derived from fish viscera with high encapsulation efficiency and loading capacity. Furthermore, transmission electron microscope and confocal laser scanning microscope observations revealed the successful encapsulation of zingerone by fish viscera peptides. In addition, in vitro release and antiproliferative activity against Caco-2 cells can be significantly increased by encapsulating zingerone via peptide self-assembly. The current study advances knowledge of encapsulation of bioactive compounds through peptide self-assembly.

Configurable direction sensitivity of skin-mounted microfluidic strain sensor with auxetic metamaterial.

Electromechanical coupling plays a key role in determining the performance of stretchable strain sensor. Current regulation of the electromechanical coupling in stretchable strain sensor is largely restricted by the intrinsic mechanical properties of the device. In this study, a microfluidic strain sensor based on the core-shell package design with the auxetic metamaterial (AM) is presented. By overriding the mechanical properties of the device, the AM in the package effectively tunes the deformation of the microfluidic channel with the applied strain and configures the directional strain sensitivity with a large modulation range. The gauge factor (GF) of the strain sensor in the radial direction of the channel can be gradually shifted from the intrinsically negative value to a positive one by adopting the AMs with different designs. By simply replacing the AM in the package, the microfluidic strain sensor with the core-shell package can be configurated as an omnidirectional or directional stretchable strain sensor. With the directional sensitivity brought by the rational AM design, the application of the AM-integrated strain sensor in the skin-mounted tactile detection is demonstrated with high tolerance to unintended wrist movements.

Photosynthetic compensation of maize in heterogeneous light is impaired by restricted photosynthate export.

When a plant is exposed to heterogeneous light, the photosynthesis of unshaded leaves is often stimulated to compensate for the decline in photosynthesis of shaded leaves, i.e., photosynthetic compensation. However, a decline of photosynthesis in unshaded leaves, which means an impairment of photosynthetic compensation, has also been widely reported. Herein, two cultivars of maize (Zea mays L.), 'Rongyu1210' (RY) and 'Zhongdan808' (ZD), were studied comparatively. Both cultivars performed evident photosynthetic compensation under heterogeneous light (HL) as the light phase begins (8:30 a.m.). However, as the light phase continues (10:30 a.m.), an impairment of photosynthetic compensation took place in HL-treated ZD, but not in HL-treated RY. For both cultivars, nitrogen content of unshaded leaves was higher under HL, indicating a preferential nitrogen distribution towards unshaded leaves. This is related to the photosynthetic compensation but not the cause of the impairment. In addition, no obvious difference was found in the response of photosynthates (sucrose and starch) to HL between cultivars at 8:30 a.m. However, at 10:30 a.m., the content of photosynthates decreased significantly in unshaded leaves of HL-treated RY, along with increased abundances of both sucrose transporters (SUTs) and H+-ATPase (EC 7.1.2.1). In contrast, it increased along with decreased abundances of SUTs and H+-ATPase in HL-treated ZD. These results suggest that the photosynthetic compensation is impaired when photosynthates export of unshaded leaves is restricted. This suggestion is further confirmed by the results of 13C labeling and dry weight detection on young leaves as 'sink'.

A programmable and skin temperature-activated electromechanical synergistic dressing for effective wound healing.

Mechanical regulation and electric stimulation hold great promise in skin tissue engineering for manipulating wound healing. However, the complexity of equipment operation and stimulation implementation remains an ongoing challenge in clinical applications. Here, we propose a programmable and skin temperature-activated electromechanical synergistic wound dressing composed of a shape memory alloy-based mechanical metamaterial for wound contraction and an antibacterial electret thin film for electric field generation. This strategy is successfully demonstrated on rats to achieve effective wound healing in as short as 4 and 8 days for linear and circular wounds, respectively, with a statistically significant over 50% improvement in wound closure rate versus the blank control group. The optimally designed electromechanical synergistic stimulation could regulate the wound microenvironment to accelerate healing metabolism, promote wound closure, and inhibit infection. This work provided an effective wound healing strategy in the context of a programmable temperature-responsive, battery-free electromechanical synergistic biomedical device.

Potential importance of malate diffusion in the response of maize photosynthesis to heterogeneous light.

It is well known that the photosynthetic performance of a leaf is highly dependent on the systemic regulation from distal parts within a plant under light heterogeneity. However, there are few studies focusing on C4-specific processes. In the present study, two cultivars of maize (Zea mays L.), 'Rongyu 1210' (RY) and 'Zhongdan 808' (ZD), were treated with heterogeneous light (HL). The net photosynthetic rate (Pn) of newly developed leaves was found to increase in HL-treated RY, while it decreased in HL-treated ZD. Result also showed a negative correlation between the Pn and the content of malate, a key metabolite in C4 photosynthesis, in these two cultivars. In HL-treated ZD, malate content increased with a decline in the abundance of NADP-malic enzyme (EC 1.1.1.40), suggesting that less malate was decarboxylated. Moreover, a restriction of malate diffusion is proposed in HL-treated ZD, since the interface length between mesophyll cells (MC) and bundle sheath cells (BSC) decreased. In contrast, malate diffusion and subsequent decarboxylation in HL-treated RY should be stimulated, due to an increase in the abundance of NADP-malate dehydrogenase (EC 1.1.1.82) and a decline in the content of malate. In this case, malate diffusion from MC to BSC should be systemically stimulated, thereby facilitating C4 photosynthesis of a maize leaf in heterogeneous light. While if it is systemically restricted, C4 photosynthesis would be suppressed.

Comparative study on the different responses of maize photosynthesis to systemic regulation under light heterogeneity.

Photosynthetic performance of a leaf is widely recognized to be systemically regulated by distal parts within the same plant. However, the effects of systemic regulation on different plant materials cannot be generalized. In this work, two cultivars of maize (Zea mays L.), 'Rongyu 1210' (RY) and 'Zhongdan 808' (ZD), were selected for a comparative study on the different responses of photosynthesis to light-dependent systemic regulation. After the growth of plants in heterogeneous light, the net photosynthetic rate of newly developed leaves increased in RY but decreased in ZD. A distinct capacity of CO2 fixation and assimilation between these two cultivars is also suggested. In ZD, the area of vascular bundles declined obviously, suggesting a restriction on carbohydrate export, which is also indicated by an increase in starch content. Resulting excessive accumulation of carbohydrates is proposed to inhibit the carbon assimilation, and eventually the photosynthesis. A decline in the area of bundle sheath cells also suggests a restriction on carbon assimilation. In contrast, these restrictions were unlikely to present in RY. This study reveals that the response of leaf photosynthetic performance to light heterogeneity is largely dependent on the systemic regulation of carbon assimilation, as well as carbohydrate export in maize.

Chlorite formation during ClO2 oxidation of model compounds having various functional groups and humic substances.

Chlorine dioxide (ClO2) has been used as an alternative to chlorine in water purification to reduce the formation of halogenated by-products and give superior inactivation of microorganisms. However, the formation of chlorite (ClO2-) is a major consideration in the application of ClO2. In order to improve understanding in ClO2- formation kinetics and mechanisms, this study investigated the reactions of ClO2 with 30 model compounds, 10 humic substances and 2 surface waters. ClO2- yields were found to be dependent on the distribution of functional groups. ClO2 oxidation of amines, di- and tri-hydroxybenzenes at pH 7.0 had ClO2- yields >50%, while oxidation of olefins, thiols and benzoquinones had ClO2- yields <50%. ClO2- yields from humic substances depended on the ClO2 dose, pH and varied with different reaction intervals, which mirrored the behavior of the model compounds. Phenolic moieties served as dominant fast-reacting precursors (during the first 5 min of disinfection). Aromatic precursors (e.g., non-phenolic lignins or benzoquinones) contributed to ClO2- formation over longer reaction time (up to 24  h). The total antioxidant capacity (indication of the amount of electron-donating moieties) determined by the Folin-Ciocalteu method was a good indicator of ClO2-reactive precursors in waters, which correlated with the ClO2 demand of waters. Waters bearing high total antioxidant capacity tended to generate more ClO2- at equivalent ClO2 exposure, but the prediction in natural water should be conservative.

Involvement of carbohydrates in long-term light-dependent systemic regulation on photosynthesis of maize under light heterogeneity.

It is widely recognized that different parts of a plant can communicate with each other via light-dependent long-distance signaling under heterogeneous light conditions. However, the mechanism of such systemic signaling has not been revealed yet. Our studies on different species suggest the involvement of carbohydrates in light-dependent systemic regulation between different parts of a plant under both short- and long-term light heterogeneity. Leaves exposed to better light condition perform enhanced photosynthetic capacity, and act to compensate for the decline in photosynthesis of other leaves under bad light condition within the same plant. This kind of compensatory photosynthesis has a close relationship to the distribution of carbohydrates, and can be regarded as an integrative strategy to make efficient use of sunlight at the whole-plant level.

Differential UV-vis absorbance can characterize the reaction of organic matter with ClO2.

UV-vis differential spectroscopy was applied to characterize and quantify the spectral changes after ClO2 oxidation of ten humic substances, seven aromatic model compounds and four surface waters. The differential spectra of ten humic substances after ClO2 oxidation all exhibited a peak near 230 nm and a broad absorbance band with a maximum at around 316 nm. The differential spectra after ClO2 oxidation were distinguished from the one after chlorination, which was indicative of their different oxidation mechanisms. The differential spectra after ClO2 treatment were well fitted by seven Gaussian bands with maxima at about 200, 225, 240, 276, 316, 385 and 457 nm. Differential absorbance at 316 nm and 400 nm (denoted as DA316 and DA400, respectively) were found to best quantify the degradation of organic matters during ClO2 oxidation with negligible interferences from water matrixes. Oxidation of substituted functional groups on aromatic structures, rather than destruction of aromatic rings, was more responsible for chlorite formation. Spectral parameters-DA316 and DA400 showed strong correlations with ClO2 consumption and chlorite formation during ClO2 oxidation of humic substances and surface water samples. The results demonstrate that DA316 and DA400 can serve as promising indicators of chlorite formation and ClO2 consumption, which provide a practical approach for online water quality monitoring during ClO2 water purification.