A nanogenerator, as a self-powered system, can operate without an external power supply for energy harvesting, signal processing, and active sensing. Here, near-infrared (NIR) photothermal triggered ...pyroelectric nanogenerators based on pn-junctions are demonstrated in a p-Si/n-ZnO nanowire (NW) heterostructure for self-powered NIR photosensing. The pyroelectric-polarization potential (pyro-potential) induced within wurtzite ZnO NWs couples with the built-in electric field of the pn-junction. At the moment of turning on or off the NIR illumination, external current flow is induced by the time-varying internal electric field of the pn-heterostructure, which enables a bias-free operation of the photodetectors (PDs). The NIR PD exhibits a high on/off photocurrent ratio up to 107 and a fast photoresponse component with a rise time of 15 μs and a fall time of 21 μs. This work provides an unconventional strategy to achieve active NIR sensing, which may find promising applications in biological imaging, optoelectronic communications, and optothermal detections.
Robots that can move, feel, and respond like organisms will bring revolutionary impact to today's technologies. Soft robots with organism‐like adaptive bodies have shown great potential in vast ...robot–human and robot–environment applications. Developing skin‐like sensory devices allows them to naturally sense and interact with environment. Also, it would be better if the capabilities to feel can be active, like real skin. However, challenges in the complicated structures, incompatible moduli, poor stretchability and sensitivity, large driving voltage, and power dissipation hinder applicability of conventional technologies. Here, various actively perceivable and responsive soft robots are enabled by self‐powered active triboelectric robotic skins (tribo‐skins) that simultaneously possess excellent stretchability and excellent sensitivity in the low‐pressure regime. The tribo‐skins can actively sense proximity, contact, and pressure to external stimuli via self‐generating electricity. The driving energy comes from a natural triboelectrification effect involving the cooperation of contact electrification and electrostatic induction. The perfect integration of the tribo‐skins and soft actuators enables soft robots to perform various actively sensing and interactive tasks including actively perceiving their muscle motions, working states, textile's dampness, and even subtle human physiological signals. Moreover, the self‐generating signals can drive optoelectronic devices for visual communication and be processed for diverse sophisticated uses.
Actively perceiving and responsive soft robots that can use the triboelectric effect and self‐generating electricity to sense and respond to stimuli are demonstrated. They are enabled by self‐powered and highly stretchable triboelectric proximity‐ and pressure‐sensing skins. After homogeneous integration, these soft robots can actively perceive their body‐motions, working states, environment stimuli, baby diaper conditions, and even human pulses by self‐generating electricity.
Display omitted
•Quantifying the restoration progress of ecological quality.•Ecological quality showed an increasing trend with an interannual change of 2.46%.•The spatial aggregation effect of ...ecological quality levels gradually diminishes.•Agricultural land has the most significant impact on regional ecological quality.
Human uncontrolled land use is the main cause of ecosystem degradation and increased rock desertification in karst areas of Southern China. Landscape ecological quality assessment (LEQA) based on land use plays a significant role in promoting sustainable ecological restoration in karst rocky desertification areas. This paper selects the karst plateau canyon rocky desertification comprehensive control demonstration area in South China as the research object to accurately quantify the impact of ecological management on landscape ecological quality changes (LEQ). Based on the characteristics of the karst ecological environment, the basic theory of spatial heterogeneity and landscape pattern is applied to evaluate the ecological quality of the study area at three levels: landscape stability, landscape disturbance degree, and ecological restoration and reconstruction ability. The results showed that the comprehensive score of regional ecological quality increased from 0.539 to 0.662 from 2015-2020. However, the ecological quality level of unused land and mining areas was still poor, and unsound production activities such as ore mining were the main hindrances to improvements in landscape ecological quality. Areas of better ecological quality were mainly distributed to the north and south of the study area. Treatment measures such as returning farmland to forest and agroforestry effectively improved the ecological environment quality of these areas, but the ecological benefits brought by the treatment in different areas varied significantly. The current analysis results show that the land use-based landscape ecological quality evaluation method is applicable in karst areas with special ecological environments. This work provides a new quantitative research method for the unique ecological environment in karst areas; it can accurately identify trends in ecological environment quality changes and provide a basis for sustainable ecological restoration.
In this paper, I consider not only the crisis in conservative neoliberalism and free market economics, but a crisis of representation and plausibility in progressive new liberalism; a situation which ...leads to deadlock for progressivism in which things cannot progress. In order to address this state of crisis in the global perception of the “white left,” Critical Theory, as a mode of Western liberal thought, needs to rethink the direction of its own criticism. Additionally, Critical Theory needs to adjust its focus to respond to the deadlock presented by the rise of right-wing populism and the derogation of liberal values in these regressive times (I refer antonymically, here, to Jürgen Habermas’s use of the term “progressive”). The radical democratic ideal advocated by Habermas, comprising universal equality and emancipation, should still be the goal for liberalism, and for Critical Theory, but first of all, the achievements and advances liberal progressivism has already made need to be secured to prevent society from regressing. This does not mean making a choice between neoliberalism and authoritarianism, but that a new paradigm of thinking is due. I argue that universality is anterior to cultural pluralism, as are social topics to cultural issues, and justice of distribution to justice of identity. In the complex world of modernity, good things do not come together if there is conflict between desirable values, so choices need to be made: a ranking of real, material conditions is necessary, to ensure cohesion and progression.
Self-powered ZnO/perovskite heterostructured ultraviolet （UV） photodetectors （PDs） based on the pyro-phototronic effect have been recently reported as a promising solution for energy-efficient, ...ultrafast-response, and high-performance UV PDs. In this study, the temperature dependence of the pyro-phototronic effect on the photo-sensing performance of self-powered ZnO/perovskite heterostructured PDs was investigated. The current responses of these PDs to UV light were enhanced by 174.1% at 77 K and 28.7% at 300 K owing to the improved pyro-phototronic effect at low temperatures. The fundamentals of the pyro-phototronic effect were thoroughly studied by analyzing the charge- transfer process and the time constant of the current response of the PDs upon UV illumination. This work presents in-depth understandings about the pyro- phototronic effect on the ZnO/perovskite heterostructure and provides guidance for the design and development of corresponding optoelectronics for ultrafast photo sensing, optothermal detection, and biocompatible optoelectronic probes.
•Accurate preoperative grading of meningiomas is clinically relevant to enhance decision-making and improve the prognosis of patients.•cMRI, ADC and SWI radiomic model may be helpful for the ...prediction of meningioma grade.•Radiomic model based on cMRI, ADC map and SWI yielded the best prediction performance in predicting the meningioma grade.
To investigate the prediction performance of radiomic models based on multiparametric MRI in predicting the meningioma grade.
In all, 229 low-grade Grade I and 87 high-grade Grade II/III patients with pathologically diagnosed meningiomas were enrolled. Radiomic features from conventional MRI (cMRI), ADC maps and SWI were extracted based on the volume of entire tumor. Classification performance of different radiomic models (cMRI, ADC, SWI, cMRI + ADC, cMRI + SWI, ADC + SWI, and cMRI + ADC + SWI models) was evaluated by a nested LOOCV approach, combining the LASSO feature selection and RF classifier that was trained (1) without subsampling, and (2) with the synthetic minority over-sampling technique (SMOTE). The prediction performance of radiomic models was assessed using ROC curve and AUC of them was compared using Delong’s test.
The cMRI + ADC + SWI model demonstrated the best performance without or with subsampling, which AUCs were 0.84 and 0.81, respectively. Following the cMRI + ADC + SWI model, the AUC range of the other models was 0.75−0.80 without subsampling, and was 0.71−0.79 with subsampling. Although the cMRI + ADC model and cMRI + SWI model showed higher AUCs than the cMRI model without subsampling (0.77 vs 0.80, P = 0.037 and 0.77 vs 0.80, P = 0.009, respectively), there was no significant difference among these models with subsampling (0.78 vs 0.77, P = 0.552 and 0.78 vs 0.79, P = 0.246, respectively).
Multiparametric radiomic model based on cMRI, ADC map and SWI yielded the best prediction performance in predicting the meningioma grade, which might offer potential guidance in clinical decision-making.
The Ti50-0.5xNi50-0.5xZrx series alloys were prepared by vacuum arc melting and subsequent suction casting. Metallographic observation and tensile mechanical tests show that adding trace amount of Zr ...can reduce grain size and increase higher tensile strength and elongation， however， excessive Zr content can easily lead to the formation of brittle intermetallic compound Zr2Ni and reduce its mechanical properties. The multi-pass cold-rolling deformation and annealing treatment on Ti49.9Ni49.9Zr0.2 alloy were carried out. The results show that the tensile strength σb and the elongation δ of the Ti50－0.5xNi50－0.5xZrx alloys increase with the increase of cold-rolling deformation. Compared with the unrolled alloys， after four-passes cold-rolling deformation， the tensile strength and the elongation after fracture of the alloys increase from 561 MPa，1.14% to 768 MPa ，35.1%，respectively.Microscopic observation of SEM and TEM show that the hard Ti2Ni particles distributed along the grain boundaries during the cold roll
Metallic three-dimensional lattice structures exhibit many favorable mechanical properties including high specific strength, high mechanical efficiency and superior energy absorption capability, ...being prospective in a variety of engineering fields such as light aerospace and transportation structures as well as impact protection apparatus. In order to further compare the mechanical properties and better understand the energy absorption characteristics of metal lattice structures, enhanced pyramidal lattice structures of three strut materials was prepared by 3D printing combined with investment casting and direct metal additive manufacturing. The compressive behavior and energy absorption property are theoretically analyzed by finite element simulation and verified by experiments. It is shown that the manufacturing method of 3D printing combined with investment casting eliminates stress fluctuations in plateau stages. The relatively ideal structure is given by examination of stress–strain behavior of lattice structures with varied parameters. Moreover, the theoretical equation of compressive strength is established that can predicts equivalent modulus and absorbed energy of lattice structures.
The continuing development of nonlinear optical imaging techniques has opened many new windows in biological exploration. In this study, a nonlinear optical microscopy-multiphoton microscopy (MPM) ...was expanded to detect tumor response in rectal carcinoma after neoadjuvant therapy; especially normal tissue, pre- and post-therapeutic cancerous tissues were investigated in order to present more detailed information and make comparison. It was found that the MPM has ability not only to directly visualize histopathologic changes in rectal carcinoma, including stromal fibrosis, colloid response, residual tumors, blood vessel hyperplasia, and inflammatory reaction, which had been proven to have important influence on estimation of the prognosis and the effect of neoadjuvant treatment, but also to provide quantitative optical biomarkers including the intensity ratio of SHG over TPEF and collagen orientation index. These results show that the MPM will become a useful tool for clinicians to determine whether neoadjuvant therapy is effective or treatment strategy is approximate, and this study may provide the groundwork for further exploration into the application of MPM in a clinical setting.
Abstract
Stitched fluorescence microscope images inevitably exist in various types of stripes or artifacts caused by uncertain factors such as optical devices or specimens, which severely affects the ...image quality and downstream quantitative analysis. Here, we present a deep learning-based Stripe Self-Correction method, so-called SSCOR. Specifically, we propose a proximity sampling scheme and adversarial reciprocal self-training paradigm that enable SSCOR to utilize stripe-free patches sampled from the stitched microscope image itself to correct their adjacent stripe patches. Comparing to off-the-shelf approaches, SSCOR can not only adaptively correct non-uniform, oblique, and grid stripes, but also remove scanning, bubble, and out-of-focus artifacts, achieving the state-of-the-art performance across different imaging conditions and modalities. Moreover, SSCOR does not require any physical parameter estimation, patch-wise manual annotation, or raw stitched information in the correction process. This provides an intelligent prior-free image restoration solution for microscopists or even microscope companies, thus ensuring more precise biomedical applications for researchers.
PDF
