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Dielectrics have long been considered as unsuitable for pure electrical switches; under weak electric fields, they show extremely low conductivity, whereas under strong fields, they suffer from irreversible damage. Here, we show that flexoelectricity enables damage-free exposure of dielectrics to strong electric fields, leading to reversible switching between electrical states—insulating and conducting. Applying strain gradients with an atomic force microscope tip polarizes an ultrathin film of an archetypal dielectric SrTiO 3 via flexoelectricity, which in turn generates non-destructive, strong electrostatic fields. When the applied strain gradient exceeds a certain value, SrTiO 3 suddenly becomes highly conductive, yielding at least around a 10 8 -fold decrease in room-temperature resistivity. We explain this phenomenon, which we call the colossal flexoresistance, based on the abrupt increase in the tunneling conductance of ultrathin SrTiO 3 under strain gradients. Our work extends the scope of electrical control in solids, and inspires further exploration of dielectric responses to strong electromechanical fields. Manipulating the electric state of large band gap dielectrics without any damage is quite challenging. Here, the authors demonstrate by mechanically introducing strain gradients that large electric fields are generated via flexoelectric interactions, resulting in a reversible Zener breakdown in SrTiO 3 , changing the resistivity by 10 8 .

High-quality genetic maps play important roles in QTL mapping and molecular marker-assisted breeding. Tea leaves are not only important vegetative organs but are also the organ for harvest with important economic value. However, the key genes and genetic mechanism of regulating leaf area have not been clarified. In this study, we performed whole-genome resequencing on “Jinxuan,” “Yuncha 1” and their 96 F1 hybrid offspring. From the 1.84 Tb of original sequencing data, abundant genetic variation loci were identified, including 28,144,625 SNPs and 2,780,380 indels. By integrating the markers of a previously reported genetic map, a high-density genetic map consisting of 15 linkage groups including 8,956 high-quality SNPs was constructed. The total length of the genetic map is 1,490.81 cM, which shows good collinearity with the genome. A total of 25 representative markers (potential QTLs) related to leaf area were identified, and there were genes differentially expressed in large and small leaf samples near these markers. GWAS analysis further verified the reliability of QTL mapping. Thirty-one pairs of newly developed indel markers located near these potential QTLs showed high polymorphism and had good discrimination between large and small leaf tea plant samples. Our research will provide necessary support and new insights for tea plant genetic breeding, quantitative trait mapping and yield improvement.

Multiferroic materials composed of ferromagnetic and ferroelectric components are interesting for technological applications due to sizable magnetoelectric coupling allowing the control of magnetic properties by electric fields. Due to being compatible with the silicon-based technology, HfO2-based ferroelectrics could serve as a promising component in the composite multiferroics. Recently, a strong charge-mediated magnetoelectric coupling has been predicted for a Ni/HfO2 multiferroic heterostructure. Here, using density functional theory calculations, we systematically study the effects of the interfacial oxygen stoichiometry relevant to experiments on the magnetoelectric effect at the Ni/HfO2 interface. We demonstrate that the magnetoelectric effect is very sensitive to the interface stoichiometry and is reversed if an oxidized Ni monolayer is formed at the interface. The reversal of the magnetoelectric effect is driven by a strong Ni−O bonding producing exchange-split polarization-sensitive antibonding states at the Fermi energy. We argue that the predicted reversal of the magnetoelectric effect is typical for other 3d ferromagnetic metals, such as Co and Fe, where the metal-oxide antibonding states have an opposite spin polarization compared to that in the pristine ferromagnetic metals. Our results provide an important insight into the mechanism of the interfacial magnetoelectric coupling, which is essential for the physics and application of multiferroic heterostructures.

The Rashba effect has recently attracted great attention owing to emerging physical properties associated with it. The interplay between the Rashba effect and the Zeeman effect, being produced by the exchange field, is expected to broaden the range of these properties and even result in novel phenomena. Here we predict an insulator-to-conductor transition driven by the Rashba–Zeeman effect. We first illustrate this effect using a general Hamiltonian model and show that the insulator-to-conductor transition can be triggered under certain Rashba and exchange-field strengths. Then, we exemplify this phenomenon by considering an Ag2Te/Cr2O3 heterostructure, where the electronic structure of the Ag2Te monolayer is affected across the interface by the proximity effect of the Cr2O3 antiferromagnetic layer with well-defined surface magnetization. Based on first-principles calculations, we predict that such a system can be driven into either insulating or conducting phase, depending on the surface magnetization orientation of the Cr2O3 layer. Our results enrich the Rashba–Zeeman physics and provide useful guidelines for the realization of the insulator-to-conductor transition, which may be interesting for experimental verification.

Tea plants are economically important woody plants that originated in southwestern China. The Yunnan Province in China is regarded as the central origin of tea plants owing to the abundance and diversity of the tea germplasm present in this region. However, there is a lack of knowledge regarding the genetic diversity and evolutionary relationships among tea plants in this region. Here, a total of 266,397 high-quality single nucleotide polymorphisms were obtained using double digest restriction-site associated DNA sequencing from 468 tea accessions collected from Yunnan. The phylogenetic relationship and population structure of the 468 tea accessions revealed remarkable inter- and intraspecific introgression across different sect. Thea species. We found that Camellia taliensis (W. W. Smith) Melchior is the main genetic donor that greatly contributed to the domestication of C . sinensis (L.) O. Kuntze, as evidenced by the frequent generation of genetic intermediates derived from the hybridization between C. sinensis and C. taliensis in Lincang, Xishuangbanna, and Pu’er. Notable genetic differences were observed across the populations from distinct regions of Yunnan. Additionally, the Lancang River may have attenuated the genetic interflow between Lincang and Pu’er. Finally, a core collection of 50 tea accessions was constructed based on the genetic diversity of the 468 tea accessions. Our results provide novel insights into the evolutionary and domestication history of tea plants in Yunnan Province and can facilitate the development of strategies for the conservation, breeding, and utilization of the core collection.

Tea plants, which are among the world’s most economically important beverage crops, exhibit extensive genetic diversity and are rich in secondary metabolites. While structural variations (SVs) drive phenotypic diversification, their regulatory roles in transcriptional networks and agronomic traits remain underexplored in this perennial crop. Here, we construct a pangenome from 22 representative tea accessions and their wild relatives. Genomic SV analysis reveals that 22% of the gene promoters contain variants influencing flavonoid, amino acid, and terpenoid biosynthesis. Population SV analysis of 275 tea accessions reveals three haplotypes in the ANS3 promoter, with Hap1, containing a 192 bp insertion, predominantly found in wild relatives but largely lost in modern cultivars. This insertion increases CtANS3 expression and anthocyanin content in wild relatives. Additionally, a 159 bp insertion in the CtLRR1 promoter reduces resistance to Colletotrichum gloeosporioides in wild relatives. Our findings underscore SVs as pivotal regulators of flavor differentiation and adaptive evolution during tea plant domestication. The regulatory roles of structural variations (SVs) in transcriptional networks and agronomic traits of tea plants are largely unexplored. Here, the authors assemble the pangnome from 22 representative tea accessions and their wild relative and reveal SVs driving gene expression alteration and agronomic traits diversification.

Postmastectomy breast reconstruction is limited by radiotherapy-induced tissue damage, as silicone implants are prone to capsular contracture, and autologous adipose grafts are limited by resorption and necrosis. In this study, two biomaterials were developed: an injectable decellularized omentum hydrogel-adipose composite (Adipose-dECM) using decellularized omentum hydrogel (dECM) bioactivity for tissue integration and an alginate-reinforced dECM hydrogel (Alg-dECM) for mechanical resilience. O-dECM, Adipose-dECM, Adipose, Alg-dECM, and Silicone were compared in a subcutaneous evaluation in female SD rats (n = 30). Half of the rats underwent radiotherapy (28 Gy) on day 16. The recorded outcomes included small-amplitude oscillatory shear rheology, scanning electron microscopy (porosity), enzymatic mass retention (collagenase), fibrous capsule thickness, inflammatory cell density, the ratio of type I to type III collagen, and angiogenesis. Adipose-dECM showed early postradiotherapy volume retention, although the results were not statistically significant. However, long-term retention decreased to 30.75% on day 50. Compared with the other implants, Adipose-dECM had the lowest inflammatory infiltration and reduced collagen I deposition, although its capsular thickness was similar. Enhanced angiogenesis was detected in Adipose-dECM, with significantly greater CD31+ areas in the peri-implant tissue (1.31% vs 0.10%, p < 0.0001) and septa (0.60% vs 0.07%, p < 0.0001). After radiotherapy, the CD31 level remained elevated in peri-implant regions (0.84% vs 0.34%, p = 0.0010) and septa (0.29% vs 0.06%, p = 0.0003). Adipose-dECM enhanced radiation tolerance through anti-inflammatory modulation and angiogenesis. Nevertheless, its long-term volumetric stability was substantially inferior to that of silicone, indicating the need for material-level strategies to slow degradation while preserving bioactivity. Adipose-dECM therefore shows promise as a radiation-compatible bioactive scaffold for breast reconstruction but requires further optimization for durable clinical translation.

ObjectiveTo explore the effect of inspiratory muscle training (IMT) on patients with heart failure and further explore the impact of IMT on patients with heart failure with preserved ejection fraction.MethodsPubMed, EMBASE, Cochrane Library, CNKI, Wanfang and VIP databases were systematically searched. Randomized controlled trials of inspiratory muscle training in patients with heart failure were included. Revman 5.3 software was used to calculate the weighted mean difference (MD) of the combined effect size. The effects of IMT on the maximum oxygen uptake (peakVO2), maximum inspiratory pressure ( PI max), ventilation efficiency ( V E / VCO 2), six-minute walking distance (6MWD), forced expiratory volume (FEV1), forced vital capacity (FVC) and quality of life in patients with heart failure were compared and analyzed.ResultsAfter systematic retrieval and screening, 17 studies were included in this study, and the quality of the included studies was good. The results showed that IMT could increase peakVO2 (MD 2.53; 95% CI 1. 54, 3. 51; P < 0.0001) and PI max (MD 17.25; 95% CI 13. 75, 20. 75; P < 0.00001); improve the VE/VCO2 (MD −4.22; 95% CI −6.78, −1.66; P = 0.001) and significantly improve the quality of life in patients with heart failure (MD −13.34; 95% CI −20.42, −6.26; P = 0.0002). However, the effect of IMT on 6MWD in patients with heart failure was not statistically significant (MD 74.45; 95% CI −12.88,161.79; P = 0.09), and the effect on lung function (FEV1 and FVC) was also not statistically significant ( P = 0.08; P = 0.86). IMT had a more significant positive effect on peakVO2 (MD 2.98; 95% CI 1.63, 4.34; P < 0.0001) and quality of life (MD −14.52; 95% CI −18.53, −10.52; P < 0.00001) in patients with heart failure with preserved ejection fraction. Descriptive analysis suggested that IMT may positively affect dyspnoea in patients with heart failure. In addition, the choice of evaluation scale may affect the evaluation results of quality of life and dyspnoea.ConclusionIMT has a significant positive effect on respiratory status in patients with heart failure, but different dyspnoea and quality of life evaluation scales can affect the final evaluation results.

Surgical tasks are performed in a sequence of steps, and technical skill evaluation includes assessing task flow efficiency. Our objective was to describe differences in task flow for expert and novice surgeons for a basic surgical task. We used a hierarchical semantic vocabulary to decompose and annotate maneuvers and gestures for 135 instances of a surgeon's knot performed by 18 surgeons. We compared counts of maneuvers and gestures, and analyzed task flow by skill level. Experts used fewer gestures to perform the task (26.29; 95% CI = 25.21 to 27.38 for experts vs. 31.30; 95% CI = 29.05 to 33.55 for novices) and made fewer errors in gestures than novices (1.00; 95% CI = 0.61 to 1.39 vs. 2.84; 95% CI = 2.3 to 3.37). Transitions among maneuvers, and among gestures within each maneuver for expert trials were more predictable than novice trials. Activity segments and state flow transitions within a basic surgical task differ by surgical skill level, and can be used to provide targeted feedback to surgical trainees.

Ferroelectric HfO 2 -based materials hold great potential for the widespread integration of ferroelectricity into modern electronics due to their compatibility with existing Si technology. Earlier work indicated that a nanometre grain size was crucial for the stabilization of the ferroelectric phase. This constraint, associated with a high density of structural defects, obscures an insight into the intrinsic ferroelectricity of HfO 2 -based materials. Here we demonstrate that stable and enhanced polarization can be achieved in epitaxial HfO 2 films with a high degree of structural order (crystallinity). An out-of-plane polarization value of 50 μC cm –2 has been observed at room temperature in Y-doped HfO 2 (111) epitaxial thin films, with an estimated full value of intrinsic polarization of 64 μC cm –2 , which is in close agreement with density functional theory calculations. The crystal structure of films reveals the Pca 2 1 orthorhombic phase with small rhombohedral distortion, underlining the role of the structural constraint in stabilizing the ferroelectric phase. Our results suggest that it could be possible to exploit the intrinsic ferroelectricity of HfO 2 -based materials, optimizing their performance in device applications. Hafnium dioxide is of technological interest as it is compatible with silicon; however, previous work indicates that a nanometre grain size is required to generate ferroelectricity. Here ferroelectric Y-doped HfO 2 thin films with high crystallinity are grown with large crystal grain sizes, indicating that ferroelectricity is intrinsic.