Search

Establishing predictive models for the pathological response and lymph node metastasis in locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (nCRT) based on MRI radiomic features derived from the tumor and mesorectal compartment (MC). This study included 209 patients with LARC who underwent rectal MRI both before and after nCRT. The patients were divided into a training set (n = 146) and a test set (n = 63). Regions of interest (ROIs) for the tumor and MC were delineated on both pre- and post-nCRT MRI images. Radiomic features were extracted, and delta radiomic features were computed. The predictive endpoints were pathological complete response (pCR), pathological good response (pGR), and lymph node metastasis (LNM). Feature selection for various models involved sequentially removing features with a correlation coefficient > 0.9, and features with P-values ≥ 0.05 in univariate analysis, followed by LASSO regression on the remaining features. Logistic regression models were developed, and their performance was evaluated using the area under the receiver operating characteristic curve (AUC). Among the 209 LARC patients, the number of patients achieving pCR, pGR, and LNM were 44, 118, and 40, respectively. The optimal model for predicting each endpoint is the combined model that incorporates pre- and delta-radiomics features for both the tumor and MC. These models exhibited superior performance with AUC values of 0.874 (for pCR), 0.801 (for pGR), and 0.826 (for LNM), outperforming the MRI tumor regression grade (mrTRG) which yielded AUC values of 0.800, 0.715, and 0.603, respectively. The results demonstrate the potential utility of the tumor and MC radiomics features, in predicting treatment efficacy among LARC patients undergoing nCRT. [ABSTRACT FROM AUTHOR]

To investigate the difference of the components and antioxidant activity between the Se-enriched and the common chlorella extract, as well as the correlation between the components and antioxidant activity. This study determined the content of total nitrogen, total sugar, polyphenols, flavonoids, saponins, total selenium, polysaccharide and polysaccharide selenium in selenium-enriched and common chlorella extract and their ability to reduce Fe3+, scavenge DPPH·, ABTS+·, · OH and O2-·, as well as the correlation between the content and antioxidant capacity. The results showed that compared with common chlorella extract, selenium-enriched chlorella extract contained more content of total sugar, polyphenol, flavonoid, total selenium, polysaccharide and polysaccharide selenium (P<0.05), but less total nitrogen and saponins (P<0.05). The Se-enriched chlorella extract had higher activity in reducing Fe3+ and scavenging DPPH· and ABTS+·, but lower activity in scavenging ·OH and O2-· than that of common chlorella extract. Correlation analysis showed that higher content of nitrogen, total sugar, polyphenols, flavonoids, saponins, total selenium, polysaccharide and polysaccharide selenium could strengthen the antioxidant activity (P<0.05). The ·OH scavenging capacity was negatively correlated with total selenium and polysaccharide selenium (P<0.05). In general, Se-enriched chlorella extract had more physiological active substances (except total nitrogen and saponins) and stronger antioxidant activity, which would provide the potential application for Se-enriched chlorella extract in health food products. [ABSTRACT FROM AUTHOR]

While advances in technology have led to the widespread use of artificial intelligence (AI) in frontline services, the AI empathic effect is often overlooked. Based on emotional contagion theory, this research explores the impacts of AI emotional mimicry and empathic concern in service success and failure via experimental designs, respectively. Results indicate that AI with high emotional mimicry and empathic concern resulted in higher arousal and pleasure, increasing tourists' continuous usage intention. Arousal and pleasure played significant mediating roles in service success. However, while empathic concern significantly affected continuous usage intention through pleasure, arousal did not have a similar effect. The joint effects of extrinsic and intrinsic anthropomorphism (emotional mimicry) were significant in a successful service context, but not in service failure. These results have important implications for the development and promotion of AI and enriches theoretical applications of emotional contagion theory and empathy. [ABSTRACT FROM AUTHOR]

SUMMARY: Heat stress poses a significant threat to maize, especially when combined with drought. Recent research highlights the potential of water replenishment to ameliorate grain weight loss. However, the mitigating mechanisms of heat in drought stress, especially during the crucial early grain‐filling stage, remain poorly understood. We investigated the mechanism for mitigating heat in drought stress by water replenishment from the 12th to the 32nd days after silking in a controlled greenhouse experiment (Exp. I) and field trial (Exp. II). A significant reduction in grain weight was observed in heat stress compared to normal conditions. When water replenishment was applied to increase soil water content (SWC) under heat stress, the grain yield exhibited a notable increase ranging from 28.4 to 76.9%. XY335 variety was used for transcriptome sequencing to analyze starch biosynthesis and amino acid metabolisms in Exp. I. With water replenishment, the transcripts of genes responsible for trehalose 6‐phosphate phosphates (TPP), alpha‐trehalase (TRE), ADP‐glcpyrophosphorylase, and starch synthase activity were stimulated. Additionally, the expression of genes encoding TPP and TRE contributed to an enhanced conversion of trehalose to glucose. This led to the conversion of sucrose from glucose‐1‐phosphate to ADP‐glucose and ADP‐glucose to amylopectin, ultimately increasing starch production by 45.1%. Water replenishment to boost SWC during heat stress also elevated the levels of essential amino acids in maize, including arginine, serine, tyrosine, leucine, glutamic acid, and methionine, providing valuable support to maize plants in adversity. Field trials further validated the positive impact of water replenishment on SWC, resulting in a notable increase in grain yield ranging from 7.1 to 9.2%. This study highlights the vital importance of adapting to abiotic stress and underscores the necessity of developing strategies to counteract its adverse effects on crop yield. [ABSTRACT FROM AUTHOR]

This paper investigates the secure optimal tracking control problem for cyber-physical systems, in which the controller-actuator channel is jammed by denial-of-service attacks. Without leveraging model knowledge, learning-based tracking control algorithms are proposed by utilizing the measured input-output data. The impact of malicious attacks on tracking performance is discussed. More specifically, an augmented system consisted of the system model and the reference model is derived. Then the states of the augmented system are rewritten by utilizing the input, output, and reference trajectory, following which both the Bellman equation and algebraic Riccati equation are given. The conditions of existence and uniqueness of the solution to the algebraic Riccati equation are derived. Furthermore, both policy iteration and value iteration learning-based tracking control algorithms are provided for cyber-physical systems against denial-of-service attacks, and the convergence of the algorithms is also proved. Finally, a DC motor system and a numerical example are given to illustrate the effectiveness of the proposed control algorithms. [ABSTRACT FROM AUTHOR]

Biomass-derived porous carbons with developed porosity, tunable microstructures and surface chemistry, good chemical stability, and excellent electronic conductivity have been widely developed for multipurpose applications. Compared to the conventional carbonization followed by activation process, the integrated carbonization and activation (one-pot) process can simplify the synthesis procedure, reduce energy consumption and the production cost. Moreover, biomass is directly mixed with chemical activators, which have considerable catalytic activities in improving the quality of bio-oil and syngas during a high temperature process. This paper reviewed the one-pot synthesis of porous carbon materials from biomass. The developments and challenges of these porous carbon materials in energy storage and conversion are discussed to clarify their structure–function relationships. Physicochemical properties of biomass-derived porous carbons are generally affected by several factors such as biomass type, activating agent, heating method, synthesis conditions, and heteroatom doping process. An ideal strategy for the synthesis of porous carbons should be rationally designed on the basis of understanding the physicochemical properties and morphology structure of biomass. Further studies are required to develop sustainable and cost-effective activation strategies for producing biomass-derived porous carbons with tunable characteristics such as high specific surface area, hierarchical pore structure, and appropriate heteroatom-doping, which have high potential in frontier energy applications such as CO2 capture and electrochemical energy storage (e.g., supercapacitors and rechargeable ion batteries) and conversion (e.g., water splitting and CO2RR) for boosting carbon neutrality. Finally, future challenges are proposed with the aim of promoting the one-pot synthesis of porous carbons toward industrial application. [ABSTRACT FROM AUTHOR]

Objectives: Diagnostic imaging plays an important role in the pre-treatment workup of knee osteoarthritis (OA) and rheumatoid arthritis (RA). Herein, we identified a useful MRI sign of infrapatellar fat pad (IPFP) to improve diagnosis. Methods: Eighty-one age- and sex-matched RA and OA patients each, with pathological diagnosis and pre-treatment MRI were retrospectively evaluated. All randomized MR images were blinded and independently reviewed by two radiologists. The assessment process included initial diagnosis, sign evaluation, and final diagnosis, with a 3-week interval between each assessment. Broken-fat pad (BFP) sign was assessed on sagittal T2-weighted-imaging in routine MRI. The area under the curve and Cohen's kappa (κ) were used to assess the classification performance. Two shape features were extracted from IPFP for quantitative interpretation. Results: The median age of the study population was 57.6 years (range: 31.0–78.0 years). The BFP sign was detected more frequently in patients with RA (72.8%) than those with OA (21.0%). Both radiologists achieved better performance by referring to the BFP sign, with accuracies increasing from 58.0 to 75.9% and 72.8 to 79.6%, respectively. The inter-reader correlation coefficient showed an increase from fair (κ = 0.30) to substantial (κ = 0.75) upon the consideration of the BFP sign. For quantitative analysis, the IPFP of RA had significantly lower sphericity (0.54 ± 0.04 vs. 0.59 ± 0.03, p < 0.01). Despite larger surface-volume-ratio of RA (0.38 ± 0.05 vs. 0.37 ± 0.04, p = 0.25) than that of OA, there was no statistical difference. Conclusions: The BFP sign is a potentially important diagnostic clue for differentiating RA from OA with routine MRI and reducing misdiagnosis. Critical relevance statement: With the simple and feasible broken-fat pad sign, clinicians can help more patients with early accurate diagnosis and proper treatment, which may be a valuable addition to the diagnostic workup of knee MRI assessment. Key points: • Detailed identification of infrapatellar fat pad alterations of patients may be currently ignored in routine evaluation. • Broken-fat pad sign is helpful for differentiating rheumatoid arthritis and osteoarthritis. • The quantitative shape features of the infrapatellar fat pad may provide a possible explanation of the signs. • This sign has good inter-reader agreements and is feasible for clinical application. [ABSTRACT FROM AUTHOR]

Metabolic diseases such as obesity and diabetes are often thought to be caused by reduced energy expenditure, which poses a serious threat to human health. Cold exposure, exercise and caloric restriction have been shown to promote adipose tissue browning and thermogenesis. These physiological interventions increase energy expenditure and thus have emerged as promising strategies for mitigating metabolic disorders. However, that increased adipose tissue browning and thermogenesis elevate thermogenic consumption is not a reasonable explanation when humans and animals confront energetic challenges imposed by these interventions. In this review, we collected numerous results on adipose tissue browning and whitening and evaluated this bi‐directional conversion of adipocytes from the perspective of energy homeostasis. Here, we propose a new interpretation of the role of adipose tissue browning under energetic challenges: increased adipose tissue browning and thermogenesis under energy challenge is not to enhance energy expenditure, but to reestablish a more economical thermogenic pattern to maintain the core body temperature. This can be achieved by enhancing the contribution of non‐shivering thermogenesis (adipose tissue browning and thermogenesis) and lowering shivering thermogenesis and high intensity shivering. Consequently, the proportion of heat production in fat increases and that in skeletal muscle decreases, enabling skeletal muscle to devote more energy reserves to overcoming environmental stress. [ABSTRACT FROM AUTHOR]

The 3R (reuse, recycling, and recovery) waste management of wind turbine blades (WTBs) is becoming a popular subject, since it has a great practical significance in the disposal of the large numbers of upcoming end-of-life WTBs. Repurposing or reuse is a priority option, but the disposal of end-of-life WTBs on a large scale is a great challenge. Recycling or recovery is considered a priority for effectively dealing with end-of-life WTBs. This review focuses on the progress and challenges in the recycling and recovery of end-of-life WTBs, which are mainly composed of fiber-reinforced polymer composites. Among the commonly-used recycling methods, one advantage of thermal recycling processes is their tolerance of contaminated material. Thermal recycling processes can also effectively treat various polymer composites on a large scale. In particular, pyrolysis and cement kiln co-processing currently show the highest potential in treating end-of-life WTBs in commercial applications. In addition, chemical recycling processes such as solvolysis are promising methods that can achieve the closed-loop recovery of monomers and high-quality fibers, if green and recyclable solvents as well as mild reaction processes can be developed. Importantly, the life cycle management (LCM) of WTBs ending with solvolysis recycling is identified as the most circular and low-carbon solution. The recycling and recovery of end-of-life WTBs have been developed at an initial stage. Although a number of commercial applications have been achieved, most of these projects are built on extensive methods, focusing on mechanical recycling and cement kiln co-processing. This review will guide researchers to make more effort in the recycling of end-of-life WTBs, covering the reuse of gas and oil products as fuels for sustaining thermal processes and the development of green closed-loop recycling processes. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the image quality and diagnostic performance of AI-assisted compressed sensing (ACS) accelerated two-dimensional fast spin-echo MRI compared with standard parallel imaging (PI) in clinical 3.0T rapid knee scans. Methods: This prospective study enrolled 130 consecutive participants between March and September 2022. The MRI scan procedure included one 8.0-min PI protocol and two ACS protocols (3.5 min and 2.0 min). Quantitative image quality assessments were performed by evaluating edge rise distance (ERD) and signal-to-noise ratio (SNR). Shapiro-Wilk tests were performed and investigated by the Friedman test and post hoc analyses. Three radiologists independently evaluated structural disorders for each participant. Fleiss κ analysis was used to compare inter-reader and inter-protocol agreements. The diagnostic performance of each protocol was investigated and compared by DeLong's test. The threshold for statistical significance was set at p < 0.05. Results: A total of 150 knee MRI examinations constituted the study cohort. For the quantitative assessment of four conventional sequences with ACS protocols, SNR improved significantly (p < 0.001), and ERD was significantly reduced or equivalent to the PI protocol. For the abnormality evaluated, the intraclass correlation coefficient ranged from moderate to substantial between readers (κ = 0.75–0.98) and between protocols (κ = 0.73–0.98). For meniscal tears, cruciate ligament tears, and cartilage defects, the diagnostic performance of ACS protocols was considered equivalent to PI protocol (Delong test, p > 0.05). Conclusions: Compared with the conventional PI acquisition, the novel ACS protocol demonstrated superior image quality and was feasible for achieving equivalent detection of structural abnormalities while reducing acquisition time by half. Clinical relevance statement: Artificial intelligence–assisted compressed sensing (ACS) providing excellent quality and a 75% reduction in scanning time presents significant clinical advantages in improving the efficiency and accessibility of knee MRI for more patients. Key Points: • The prospective multi-reader study showed no difference in diagnostic performance between parallel imaging and AI-assisted compression sensing (ACS) was found. • Reduced scan time, sharper delineation, and less noise with ACS reconstruction. • Improved efficiency of the clinical knee MRI examination by the ACS acceleration. [ABSTRACT FROM AUTHOR]

High speed broadband photodetectors (PDs) have attracted significant interest for many applications such as imaging, gas sensing, and night vision. In this study, the widest reported detection range is achieved from 254 nm to 1800 nm by integrating CsPb(BrCl)3: Yb3+ nanocrystals (NCs) with Germanium (Ge) on a Si substrate. To overcome the persistent photoconductance (PPC) effect that limits the detector response speed in the UV region, this study proposes a down conversion technology to convert UV light to 980 nm infrared light by applying a CsPb(BrCl)3: Yb3+ NCs. The response time of the hybrid PD at 275 nm decreased significantly from several hundred seconds to 1.21 µs. Moreover, benefiting from the CsPb(BrCl)3: Yb3+ NCs antireflection layer, the responsivity of a hybrid CsPb(BrCl)3: Yb3+ NCs /Ge metal semiconductor metal (MSM) PD has enhanced the whole detection band, especially at 1310 nm, which increased by 80% from 0.16 to 0.29 A W−1. This work promotes the development of perovskite integrated optoelectronic devices and provides a feasible route for broad‐band PD from the UV to near infrared (NIR) band. [ABSTRACT FROM AUTHOR]

Due to the advantages of low propagation loss, wide operation bandwidth, continuous delay tuning, fast tuning speed, and compact footprints, chirped Bragg grating waveguide has great application potential in wideband phased array beamforming systems. However, the disadvantage of large group delay error hinders their practical applications. The nonlinear group delay spectrum is one of the main factors causing large group delay errors. To solve this problem, waveguides with nonlinear gradient widths are adopted in this study to compensate for the nonlinear effect of the grating apodization on the mode effective index. As a result, a linear group delay spectrum is obtained in the experiment, and the group delay error is halved. [ABSTRACT FROM AUTHOR]

Brown adipose tissue (BAT) has been widely studied in targeting against metabolic diseases such as obesity, type 2 diabetes and insulin resistance due to its role in nutrient metabolism and energy regulation. Whether exercise promotes adipose tissue thermogenesis and browning remains controversial. The results from human and rodent studies contradict each other. In our opinion, fat thermogenesis or browning promoted by exercise should not be a biomarker of health benefits, but an adaptation under the stress between body temperature regulation and energy supply and expenditure of multiple organs. In this review, we discuss some factors that may contribute to conflicting experimental results, such as different thermoneutral zones, gender, training experience and the heterogeneity of fat depots. In addition, we explain that a redox state in cells potentially causes thermogenesis heterogeneity and different oxidation states of UCP1, which has led to the discrepancies noted in previous studies. We describe a network by which exercise orchestrates the browning and thermogenesis of adipose tissue with total energy expenditure through multiple organs (muscle, brain, liver and adipose tissue) and multiple pathways (nerve, endocrine and metabolic products), providing a possible interpretation for the conflicting findings. [ABSTRACT FROM AUTHOR]

Voice-driven face generation aims to explore the static and dynamic correlation between voice fragments and faces, so that it can generate corresponding face images from a given voice fragment. However, most of the existing research only consider one of the correlations. In addition, the methods on static face generation rely on time-aligned audio-visual data strictly, which limits the use of such static models to a certain extent. Therefore, a voice-driven static and dynamic face generation model (SDVF-GAN) is proposed based on conditional generative adversarial networks. SDVF- GAN builds a voice encoder network, which obtains more accurate auditory feature through the self-attention mechanism. Both the static and dynamic generation network takes these auditory features as input. For static generation network, it uses image discriminator based on the projection layer, which ensures it can synthesize static face images with consistent attributes ( age, gender) and high quality. The dynamic generation network uses the image discriminator and attention-based lip discriminator to generate a sequence of dynamic face image with lip synchronization. In experiment, the authors constructs an attribute-aligned Voice-Face dataset to optimize the parameters of static model and uses the existing LRW dataset to train the dynamic model. The results demonstrate that model studies the attribute correspondence and lip synchronization relationship between voice and face comprehensively, it can generate face images with higher quality and stronger correlation and synchronization. [ABSTRACT FROM AUTHOR]

An undoped Ge/SiGe quantum well has been grown by ultrahigh vacuum chemical vapor deposition, and the sharp interface with a characteristic length of 0.6 nm is confirmed by cross-sectional transmission electron microscopy and electron energy loss spectroscopy. In addition, a 2D hole gas with a high mobility of up to 4.6 × 105 cm2/V s is achieved in the Hall-bar shaped field effect transistor, showing a low percolation density of 8.7 × 1010 cm−2, a light hole effective mass of 0.071 m0, and a high effective g-factor of 11.3. These favorable properties confirm the benefits of high-quality interface, which has promising applications in the field of qubits. [ABSTRACT FROM AUTHOR]

Seafloor unconstrained environment video is shot in uncontrolled open sea area. There are multiple backgrounds, complex illumination and weather changes, and rapid growth of algae and attached lenses, which affect the stability of video shooting quality, resulting in difficulty in image recognition. At present, there is still no algorithm that is superior to other methods generally, and it is necessary to build a model combined with specific scenes and applications. In this paper, a fish identification method in tropical waters based on transfer learning under unconstrained environment is proposed. Firstly, the image is pre-processed by affine transformation to realize data enhancement. Furthermore, RestNet50 deep convolutional neural network is constructed based on transfer learning to compare the effect of fish recognition before and after transfer learning. The results show that, the accuracy and loss indicators are better than those of non-transfer learning when the trained model of imagenet is introduced as the initial weight of the network. When the model is trained to 150 epochs, the indicators begin to converge, which can better complete the fish identification task in tropical waters under unconstrained environment. [ABSTRACT FROM AUTHOR]

Owing to the widespread deployment of face and speaker recognition systems, research on attacks on neural‐network‐based biometric systems, which involves face or voice signal classification problems with a low‐dimensional output vector, has drawn increasing attention. Recently, cross‐modal voice‐to‐face (VTF) systems have learned to generate faces from voices by matching several biometric characteristics of the generated faces to those of speakers. However, attacks focusing on VTF systems with high‐dimensional face image outputs have not yet been conducted. In this paper, we introduce various adversarial attack methods for the VTF system under different attack conditions. These methods can generate a fake face close to the target face or far from the original face, by adding subtle perturbations to the original voice. Under the white‐box setting, we formulate a multiobjective optimization to generate target faces and improve the imperceptibility of the adversarial sample. Further a stepwise iterative optimization strategy is proposed to achieve faster and more effective attacks. Finally, the results of comparative experiments with various methods are demonstrated. Under the black‐box setting, the adversarial samples generated from surrogate models are able to generate the fake face far from the original one. Qualitative and quantitative experimental results show the high target face‐matching rate and irrelevance to the original face, as well as the imperceptibility of the adversarial audio. This study provides useful insights for privacy protection and improving generation robustness for information security. [ABSTRACT FROM AUTHOR]

The Sn composition graded GeSn layer with Sn content increased from 11% to 14.3% was grown on a Si substrate by molecular beam epitaxy. The structural properties of the GeSn layer are investigated, and the film is gradually relaxed along the thickness, reaching approximately 71.6%. The GeSn p–i–n detectors were fabricated by using a complementary metal oxide semiconductor compatible process. The GeSn detectors demonstrated a cutoff wavelength of approximately 3.3 μm at room temperature with a dark current of 0.3 A/cm2 @ -1 V. At a wavelength of 2000 nm, the GeSn detectors had a responsivity of 110 mA/W and -3 dB bandwidth (f3 dB) about 3 GHz. These results suggest that high Sn content relax GeSn can be grown by MBE and paves the way toward the feasibility of mid-infrared GeSn photonics. [ABSTRACT FROM AUTHOR]

Background: The pathology, treatment and prognosis of malignant non-Wilms tumors (NWTs) are different, so it is necessary to differentiate these types of tumors. The purpose of this study was to review the clinical and imaging features of malignant NWTs and features of tumor metastasis. Methods: We retrospectively analyzed the CT images of 65 pediatric patients with NWTs from March 2008 to July 2020, mainly including clear cell sarcoma of the kidney (CCSK), malignant rhabdomyoma tumor of the kidney (MRTK) and renal cell carcinoma (RCC). Available pretreatment contrast-enhanced abdominal CT examinations were reviewed. The clinical features of the patients, imaging findings of the primary mass, and locoregional metastasis patterns were evaluated in correlation with pathological and surgical findings. Results: The study included CCSK (22 cases), MRTK (27 cases) and RCC (16 cases). There were no significant differences observed among the sex ratios of CCSK, MRTK and RCC (all P > 0.05). Among the three tumors, the onset age of MRTK patients was the smallest, while that of RCC patients was the largest (all P < 0.05). The tumor diameter of CCSK was larger than that of MRTK and RCC (all P < 0.001). For hemorrhage and necrosis, the proportion of MRTK patients was larger than that of the other two tumors (P = 0.017). For calcification in tumors, the proportion of calcification in RCC was highest (P = 0.009). Only MRTK showed subcapsular fluid (P < 0.001). In the arterial phase, the proportion of slight enhancement in RCC was lower than that in the other two tumors (P = 0.007), and the proportion of marked enhancement was the highest (P = 0.002). In the venous phase, the proportion of slight enhancement in RCC was lower than that in the other two tumors (P < 0.001). Only CCSK had bone metastasis. There was no liver and lung metastasis in RCC. Conclusions: NWTs have their own imaging and clinical manifestations. CCSK can cause vertebral metastasis, MRTK can cause subcapsular effusion, and RCC tumor density is usually high and calcification. These diagnostic points can play a role in clinical diagnosis. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) transition metal dichalcogenides (TMDs) with tantalizing layer-dependent electronic and optical properties have emerged as a paradigm for integrated flat opto-electronic devices, but their widespread applications are hampered by challenges in deterministic fabrication with demanded shapes and thicknesses, as well as light field manipulation in such atomic-thick layers with negligible thicknesses compared to the wavelength. Here we demonstrate ultra-sensitive light field manipulation in full visible ranges based on MoS2 laser prints exfoliated with nanometric precisions. The nontrivial interfacial phase shifts stemming from the unique dispersion of MoS2 layers integrated on the metallic substrate empower an ultra-sensitive resonance manipulation up to 13.95 nm per MoS2 layer across the entire visible bands, which is up to one-order-of-magnitude larger than their counterparts. The interlayer van der Waals interactions and the anisotropic thermal conductivity of layered MoS2 films endow a laser exfoliation method for on-demand patterning MoS2 with atomic thickness precision and subwavelength feature sizes. With this, nanometric flat color prints and further amplitude-modulated diffractive components for binocular stereoscopic images can be realized in a facile and lithography-free fashion. Our results with demonstrated practicality unlock the potentials of, and pave the way for, widespread applications of emerging 2D flat optics. The authors demonstrate fidelity colour prints and binocular stereoscopic images in multilayer MoS2 integrated on an Au substrate, showing nanometric layer sensitivity in the Fabry-Perot resonance changed by a facile laser recipe. [ABSTRACT FROM AUTHOR]

Main observation and conclusion: With the increasing demand of sustainable and eco‐friendly resources, it is very attractive to use waste leaves for activated carbon (AC) preparation that can be used in supercapacitors. Considering the practically collected leaves are commonly in mixed nature, and extra efforts are needed to sort these mixtures, we here report the first preparation of AC using mixed leaves from different plants, including Platanus acerifolia (PA), Firmiana platanifolia (FP) and Pistia stratiotes (PS), and compared the results with single leaves‐derived AC materials. These leave‐derived AC samples were characterized with FESEM, EDS, FTIR and Raman spectroscopy, and electrochemical tests. The AC derived from mixed leaves (PA3FP1PS2AC) showed a good specific capacitance of 246 F·g−1 at 1 A·g−1 in aqueous 3 mol·L–1 KOH. This sample further showed the largest specific capacitance of 201 F·g−1 at 5 A·g−1, as compared with the non‐mixed AC samples, and a good stability of 100.0% capacitance retention over 1000 cycles. Utilizing mixed leaves for AC preparation is not only demonstrated to be a promising approach of low cost and high‐performance AC production for supercapacitor applications, but may also help environmental protection by reducing the invasive species problem. [ABSTRACT FROM AUTHOR]

Phased array antennas (PAAs) play a key role in many fields such as radar systems and wireless communication systems. Since PAAs based on optical methods outperform the electronic counterparts in beam directivity and instantaneous bandwidth, optical PAAs have aroused wide research interests. Here, we report and experimentally demonstrate an integrated 4-channel optical true time delay network for PAAs. The true time delay unit is based on a grating-assisted contradirectional coupler, assisted by index chirp engineering and asymmetric apodization. A linear group delay with both positive and negative dispersion coefficients can be obtained. For the 4-channel time delay network, the measured dispersion coefficient of each channel is 10.35, 4.00, −4.32 and −14.38 ps/nm with 7 nm available bandwidth, respectively. The calculated beam scanning angle can range from 36.4 degree to −33.9 degree for the beam steering. This time delay network can be extended to large scale with more delay units and cascaded structures, thus wider scanning range and better beam directivity can be achieved. [ABSTRACT FROM AUTHOR]

Wavelength interrogation has been widely used for fiber-optic sensors based on Fabry‐Perot interferometers (FPIs) because of its high measurement resolution. However, phase ambiguity often limits the measurement range to be less than one free-spectral range (FSR) of the FPI. Here, we investigate a simple but effective method that can eliminate the phase ambiguity of a silicon FPI temperature sensor using a fiber Bragg grating (FBG) fabricated on the lead-in fiber close to the silicon FPI. The reflection spectrum of the sensor shows sinusoidal fringes from the FPI and a single peak from the FBG. Assuming the FBG and the silicon FPI have similar temperatures, the FBG peak can be used merely as a marker to identify an FPI fringe peak without ambiguity even when it shifts by more than an FSR. Although the temperature resolution of the FBG is lower than that of the silicon FPI, the measurement range of the silicon FPI can be greatly improved without sacrificing the measurement resolution. Using a temperature sensor based on a 75-μm-thick silicon FPI, we demonstrated temperature measurement over a range of −60 to 140 °C (corresponding to a spectral shift of about five FSRs) with a resolution of 0.0033 °C. The measurement range with unambiguous peak recognition is expected to be larger than demonstrated in the experiment and only limited by the spectral bandwidth of the sensor system and the capability of materials used for the sensor construction. [ABSTRACT FROM AUTHOR]

We report a sensitive and mechanically robust fiber-optic refractometer with temperature compensation based on a Fabry–Perot interferometer formed by two chirped fiber Bragg gratings on a seven-core multicore fiber. A small part of the fiber cladding at the sensing region is etched to expose the outer cores to the environment. While the optical modes supported by the outer cores are affected by both temperature and refractive index (RI) changes of the surrounding liquid, the optical mode in the central core of the fiber is affected by the temperature changes only. The wavelength shift due to the RI change is obtained by subtracting the wavelength shift of the central core from that of one of the outer cores so that the temperature effect is removed. The demodulation can also remove the errors caused by the wavelength drift of laser. Due to the narrow spectral features of the sensor, the sensor shows a low RI detection limit of ${2.4} \times {10}^{-{6}}$ at a background RI of 1.316 at a wavelength of ~1550 nm. Because only a small part of the cladding is removed, the sensor maintains excellent mechanical strength and stability. [ABSTRACT FROM AUTHOR]

We report a fiber-optic strain sensor that can simultaneously achieve high resolution and large dynamic range. The sensor is a fiber-optic Fabry–Perot cavity formed by cascaded high-reflection chirped fiber Bragg gratings with opposite chirp directions. The reflection spectrum of the sensor features a series of narrow spectral notches with unequal spacings. The sensor is demodulated by the wavelength scanning of a distributed feedback laser diode through the current-injection modulation. The narrow spectral notch leads to high measurement resolution; while the unambiguous identification of the spectral notches through their unique spectral spacings results in large measurement range without the need for fringe counting. We have demonstrated a linear axial strain response of the sensor with strain resolution of $0.033~\mu \varepsilon $ over a range of $1000~\mu \varepsilon $. [ABSTRACT FROM AUTHOR]

Abstract: Fine particle matter (PM) is correlated with male reproductive dysfunction in animals and humans, but the underlying mechanisms remain unknown. To investigate the toxic mechanism of PM, 32 male Sprague‐Dawley (SD) rats were exposed to saline or PM2.5 with the doses of 1.8, 5.4, and 16.2 mg/kg.b.w. via intratracheal instillation, respectively, one time every 3 days, in total times for 30 days. Sperm concentration, hormone level, the expressions of BTB‐associated protein and the mitogen‐activated protein kinase (MAPK) pathway, tumor necrosis factor α and transforming growth factor β3 levels were detected. The results showed a decrease in sperm number, testosterone and luteinizing hormone levels and altered ultrastructure of BTB in testis of rat after exposure to PM2.5. The protein levels of N‐Cadherin, Occludin, Claudin‐11, and Connexin‐43 were significantly decreased in the testes. TGF‐β3 content in testes showed increase, with the p‐p38/p38 MAPK ratio also increasing after PM2.5 exposure. These results demonstrate that PM2.5 restrained the expressions of BTB‐associated proteins through activating TGF‐β3/p38 MAPK pathway and decreasing testosterone secretion, and therefore lead to the damage of BTB resulting in the decrease of sperm quality, which might be the potential reasons for its negative effects on spermatogenesis and male reproduction. [ABSTRACT FROM AUTHOR]

The work presented in this paper shows that Fiber Bragg Grating (FBG) optical fiber sensors can potentially be used as receivers in a long-range guided wave torsional-mode pipe inspection system. Benefits over the conventional pulse-echo method arise due to reduced total travel distance of the ultrasonic guided wave reflections, since reflections from defects and structural features do not need to propagate a full round trip back to the transmitting collar. This is especially important in pipe configurations with high attenuation, such as coated and buried pipelines. The use of FBGs as receivers instead of conventional piezoelectric or magnetostrictive elements also significantly reduces cabling, since multiple FBG receivers can be placed along a single optical fiber which has a diameter on the order of only around 100 μm. The basic approach and sample results are presented in the paper. Additionally, a brief overview of some topics in ultrasonic guided waves is presented as a background to understand the inspection problem presented here. [ABSTRACT FROM AUTHOR]

In this article, a systematic study on the magnetic properties and strain tunability of 3d transition metal ions (Mn, Fe, Co, Ni) doped MoS2 using first-principles calculations is performed. Antiferromagnetic coupling is observed between Mn, Fe ions and the nearest neighbor Mo ions; whereas ferromagnetic coupling is observed in Co and Ni systems. It is also shown that by applying biaxial tensile strain, a significant change of the magnetic moment is observed in all transition metal doped MoS2 materials with a strain threshold. The changes of total magnetic moment have different mechanisms for different doping systems including an abrupt change of the bond lengths, charge transfer and strain induced structural anisotropy. These results demonstrate applying strain as a promising method for tuning the magnetic properties in transition metal ion doped monolayer MoS2. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of different pretreatment and reducing sugar content on furfural (F) and 5-hydroxymethylfurfural (HMF) contents of fermented lotus root by vinegar. The lotus root samples were fermented using vinegar for 15 days, at different solution concentrations and temperatures. The processing conditions were considered as inputs of neural network to predict the F and HMF contents of lotus root. Genetic algorithm was applied to optimize the structure and learning parameters of ANN. The developed genetic algorithm-artificial neural network (GA-ANN) which included 23 and 17 neurons in the first and second hidden layers, respectively, gives the lowest mean squared error (MSE). The correlation coefficient of ANN was compared with multiple linear regression-based models. The GA-ANN model was found to be a more accurate prediction method for the F and HMF contents of fermented lotus root than linear regression-based models. In addition, sensitivity analysis and Pearson's correlation coefficient were also analyzed to find out the relation between input and output variables. [ABSTRACT FROM AUTHOR]

We propose a robust steganography scheme for large-capacity lossless images based on visual cryptography and ptychography. The introduction of the quick response code as a container for information hiding can realize the lossless extraction of information and performs well in robustness when subjected to compression, noise, and tailoring attacks. The security of the proposed system is provided by the Arnold scrambling algorithm, the visual cryptographic scheme, and the structural parameters of ptychography. The proposed method is verified with optical experiments. In the experiments, a spatial light modulator is used to complete specific experiments through nonmechanical moving ptychography, which greatly reduces the error of traditional ptychography experiments and improves the quality of reconstruction. The results demonstrate that the method can achieve satisfactory robustness performance with high repeatability and excellent information fidelity. [ABSTRACT FROM AUTHOR]