Search

Abstract Recapitulating the natural extracellular physical microenvironment has emerged as a promising method for tissue regeneration, as multiple physical interventions, including ultrasound, thermal and electrical therapy, have shown great potential. However, simultaneous coupling of multiple physical cues to highly bio-mimick natural characteristics for improved tissue regeneration still remains formidable. Coupling of intrinsic electrical and mechanical cues has been regarded as an effective way to modulate tissue repair. Nevertheless, precise and convenient manipulation on coupling of mechano-electrical signals within extracellular environment to facilitate tissue regeneration remains challengeable. Herein, a photothermal-sensitive piezoelectric membrane was designed for simultaneous integration of electrical and mechanical signals in response to NIR irradiation. The high-performance mechano-electrical coupling under NIR exposure synergistically triggered the promotion of osteogenic differentiation of stem cells and enhances bone defect regeneration by increasing cellular mechanical sensing, attachment, spreading and cytoskeleton remodeling. This study highlights the coupling of mechanical signals and electrical cues for modulation of osteogenesis, and sheds light on alternative bone tissue engineering therapies with multiple integrated physical cues for tissue repair. Graphical Abstract

Reduced photosynthesis results directly from nitrogen or water deficiency in wheat plants, and leads to a decrease in grain yield. In this study, by measuring the effects of water and N deficiencies, both individually and combined, we characterized the responses of wheat (Triticum aestivum L. Yumai 49–198) plants to these two deficiencies using physiological measurements and comparative proteomics. Significant decreases in grain yield and leaf photosynthetic performance were observed in all deficiency conditions, and 106 photosynthetic proteins that showed responses were identified. Nitrogen deficiency induced the least change in photosynthetic proteins, and similar changes in most of these proteins were also observed for the combined nitrogen and water deficiencies. Water deficiency induced the largest change in photosynthetic proteins and resulted in the lowest 1000-kernel weight. Severe decreases in photosynthesis in both the water-deficiency and combined N and water deficiency groups were reflected mainly in an imbalanced ATP/NADPH ratio associated with the light reaction, which influences carbon metabolism in the Calvin cycle. Photorespiration was respectively stimulated or inhibited by N or water deficiency, while suppression of photorespiratory flux and activation of nitrogen recycling were observed in the combined N and water deficiency treatments. Comparison of photosynthetic proteins between experimental sites suggested that precipitation affected linear electron flow in the photoreaction, and thus photosynthetic efficiency. Our results provide a baseline for future studies of the roles of these photosynthetic proteins in the response to N or water deficiency and their effect on 1000-kernel weight.

With the intensification of global climate problems, electric heating has recently attracted much attention as a clean and low-carbon heating method. Carbon nanotubes (CNTs) are an ideal medium for electric heating applications due to their excellent mechanical, electrical, and thermal properties. The preparation of electrothermal films based on an aqueous CNT dispersion as a raw material is environmentally friendly. However, in the traditional one-step filtration method, the residual excess dispersant and the small aspect ratio of the CNTs in the preparation process limit the performance of electrothermal CNT films. In this paper, we report a two-step filtration method that removes the free dispersant and small CNTs in the first filtration step and obtains denser CNT films by controlling the pores of the filter membrane in the second filtration step. The results suggest that, compared to the CNT1 film obtained from one-step filtration, the CNT1-0.22 film, obtained from two-step filtration using 1 and 0.22 μm membranes, has a smoother and flatter surface, and the surface resistance is 80.0 Ω sq−1, which is 29.4% lower. The convective radiation conversion efficiency of the CNT1-0.22 film is 3.36 mW/°C, which is 36.1% lower. We anticipate that such CNT films could be widely applied in building thermal insulation and underfloor heating.

Under abiotic stress, plant root exudates can improve plant growth performance. However, studies on the effect of root exudates on the stress resistance of another plant are insufficient. In this study, root exudates (REs) were extracted from Suaeda glauca to explore their effect on alfalfa seedlings under salt stress. The results showed that the plant height and fresh weight of alfalfa significantly increased by 47.72% and 53.39% after 7 days of RE treatment at a 0.4% NaCl concentration. Under 1.2% salt stress, REs reduced the Malondialdehyde content in alfalfa by 30.14% and increased the activity of its antioxidant enzymes (peroxidase and catalase) and the content of its osmotic regulators (soluble sugar and proline) by 60.68%, 52%, 45.67%, and 38.67%, respectively. Soil enzyme activity and the abundance of soil-beneficial bacteria were increased by REs. Spearman analysis showed that urease and neutral phosphatase were related to the richness of beneficial bacteria. Redundancy analysis confirmed that urease affected the composition of the soil bacterial community. The partial least squares structural equation model (PLS-SEM) revealed that REs had a direct positive effect on alfalfa growth under salt stress by regulating the plant’s injury and antioxidant systems, and the soil bacterial community had an indirect positive effect on alfalfa growth through soil enzyme activity.

Progress toward developing next-generation biomaterials applied in complex bone defect is expected to effectively integrate osteogenic and anti-bacteria capability. However, current biomaterials often achieve the two functions separately. Inspired by photothermal effect, exogenous light-induced thermal variations can efficiently facilitate bone regeneration and bacteria eradication. Here, a bioactive hydrogel BMP-2@PNH-TA with simultaneously osteogenic and anti-bacterial capacities is presented, which is based on the near infrared (NIR) induced photothermal effect to perform integrated photothermal therapy (PTT). In detail, photothermal effect and photothermal-controlled release of osteogenic and anti-bacterial factors through sponge-like effect could exert integrated influence on bone regeneration under complex situation. The composite hydrogel can mediate pro-osteogenesis under mild temperature and controlled release of BMP-2 and tannin in response to NIR stimulation with low power, while efficiently eradicate bacteria via controlled release of O-HACC and thermal effect with high power. The customized PTT strategy significantly shortened the duration time of bone regeneration up to almost 50% in rat cranial bone defect. It is anticipated that the concept of integrated PTT for bone regeneration will cast new insights into developing high-performance therapeutic strategy with combined biological functions.

Graphene oxide (GO) has shown remarkable performance in the multiple-equilibrium-route adsorption (MER) process, which is characterized by further activation of GO through an in-situ reduction process based on single-equilibrium-route adsorption (SER), generating new adsorption sites and achieving an adsorption capacity increase. However, the effect of GO on MER adsorption in lateral size and thickness is still unclear. Here, GO sheets were sonicated for different lengths of time, and the adsorption of MER and SER was investigated at three temperatures to remove the typical cationic dye, acridine orange (AO). After sonication, we found that freshly prepared GO was greatly reduced in lateral size and thickness. In about 30 min, the thickness of GO decreased dramatically from several atomic layers to fewer atomic layers to a single atomic layer, which was completely stripped off; after that, the monolayer lateral size reduction dominated until it remained constant. Surface functional sites, such as hydroxyl groups, showed little change in the experiments. However, GO mainly reduces the C=O and C-O bonds in MER, except for the conjugated carbon backbone (C-C). The SER adsorption kinetics of all temperatures fitted the pseudo-first-order and pseudo-second-order models, yet room temperature preferred the latter. An overall adsorption enhancement appeared as sonication time, but the equilibrium capacity of SER GO generally increased with thickness and decreased with the single-layer lateral size, while MER GO conversed concerning the thickness. The escalated temperature facilitated the exfoliation of GO regarding the adsorption mechanism. Thus, the isotherm behaviors of the SER GO changed from the Freundlich model to Langmuir as size and temperature changed, while the MER GO were all of the Freundlich. A record capacity of ~4.3 g of AO per gram of GO was obtained from the MER adsorption with a sixty-minute ultrasonicated GO at 313.15 K. This work promises a cornerstone for MER adsorption with GO as an adsorbent.

The Yunnan-Guizhou Plateau in southwest China lies at the intersection between East and South Asia, and is characterised by highly complex vegetation ranging from subtropical forest to open grassland. There is a long history of human modification to the landscape, but we know surprisingly little of the biogeography of open habitats such as grassy biomes in the region. To investigate the historical continuity of grassy biomes in southwest China, we examined the biogeographies and evolutionary histories of two widespread and dominant C4 grasses, Themeda triandra and Heteropogon contortus, in Yunnan and southern Sichuan provinces, using chloroplast DNA markers in combination with climate data. We discovered that cool- and warm-adapted lineages have been widely distributed across the Yunnan-Guizhou Plateau for at least the last 2 million years, pre-dating any possible anthropogenic impact. Moreover, the high genetic diversity and strong spatial structure of both species suggests the continuous presence of multiple large populations, rather than a recent expansion from the dry valleys in response to anthropogenic deforestation. This is the first evidence for the long-term existence of extensive populations of C4 grasses in this region outside the dry valleys, and calls for a reappraisal of the conservation value of these grass-dominated landscapes.

To investigate the hypoglycemic and lipid-lowering effects of white quinoa polysaccharide (WQP) in type 2 diabetic model mice, the mice were divided into model group, polysaccharide group (800 mg/kg) and normal control group. During the experiment, body weight, fasting blood glucose (FBG), and oral glucose tolerance test (OGTT) were measured. After four weeks of continuous feeding, the mice were dissected, and the serum indexes, liver indexes, and short-chain fatty acids (SCFAs) of the mice were determined. The intestinal contents of the mice were analyzed by 16S rRNA sequencing technology. Results showed that compared with diabetic mice, WQP intake could significantly inhibit the increase of body weight and FBG, improve OGTT, and alleviate insulin resistance in diabetic mice. At the same time, the total cholesterol (TC) content of diabetic mice decreased by 19%, and the low-density lipoprotein cholesterol (LDL-C) content decreased by 33%. The intake of WQP also reduced interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) by 21% and 22%, respectively. The contents of catalase (CAT) and glutathione (GSH) were increased by 20% and 24%, respectively. The content of malondialdehyde (MDA) was decreased by 25%. In addition, the intake of WQP significantly increased the content of SCFAs in diabetic mice (P

Genetically unmodified cardiomyocytes mandated for cardiac regenerative therapy is conceivable by "foot-print free" reprogramming of somatic cells to induced pluripotent stem cells (iPSC). In this study, we report generation of foot-print free hiPSC through messenger RNA (mRNA) based reprograming. Subsequently, we characterize cardiomyocytes derived from these hiPSC using molecular and electrophysiological methods to characterize their applicability for regenerative medicine. Our results demonstrate that mRNA-iPSCs differentiate ontogenetically into cardiomyocytes with increased expression of early commitment markers of mesoderm, cardiac mesoderm, followed by cardiac specific transcriptional and sarcomeric structural and ion channel genes. Furthermore, these cardiomyocytes stained positively for sarcomeric and ion channel proteins. Based on multi-electrode array (MEA) recordings, these mRNA-hiPSC derived cardiomyocytes responded predictably to various pharmacologically active drugs that target adrenergic, sodium, calcium and potassium channels. The cardiomyocytes responded chronotropically to isoproterenol in a dose dependent manner, inotropic activity of nifidipine decreased spontaneous contractions. Moreover, Sotalol and E-4031 prolonged QT intervals, while TTX reduced sodium influx. Our results for the first time show a systemic evaluation based on molecular, structural and functional properties of cardiomyocytes differentiated from mRNA-iPSC. These results, coupled with feasibility of generating patient-specific iPSCs hold great promise for the development of large-scale generation of clinical grade cardiomyocytes for cardiac regenerative medicine.

Objective To investigate the effect of isorhamnetin on the apoptosis of retinal cells in diabetic retinopathy (DR) rats. Methods The rats were divided into control group, DR model group, low and high dose isorhamnetin groups (ISO-L group, ISO-H group, 50, 150 mg/kg isorhamnetin orally, respectively) and positive drug group (150 mg/kg calcium dobesilate orally). The level of serum inflammatory factors was measured by ELISA; HE staining and TUNEL staining were performed to observe the pathological changes and cell apoptosis of retina. Western blot method was performed to detect protein expression of VEGF, Bax, caspase-3 and phosphorylation levels of p38 MAPK, NF-κB p65 in retinal tissue. Results Compared with the control group, the retina of the model group was arranged disorderly, the boundary was unclear, the inner and outer nuclear layers were edema, the number of cells was reduced, and the thickness of the retina became thinner, and the retinal cell apoptosis rate, serum TNF-α, IL-1β, IL-6 levels, VEGF, Bax, caspase-3 protein expression and p38 MAPK, NF-κB p65 phosphorylation were significantly increased (P＜0.05); Compared with the model group, the retinal tissue layers of the ISO-L, ISO-H, and positive drug groups had clearer boundaries, slightly looser structures, and increased retinal thickness, and the retinal cell apoptosis rate, serum TNF-α, IL-1β, IL-6 levels, VEGF, Bax, caspase-3 protein expression, and p38 MAPK, NF-κB p65 phosphorylation levels were significantly reduced (P＜0.05). Conclusions Isorhamnetin may ameliorate retinal injury and cell apoptosis in DR rats by inhibiting the MAPK/NF-κB signaling pathway.