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Currently, the popular Rich Model steganalysis features usually contain a large number of redundant feature components which may bring “curse of dimensionality” and large computation cost, but the existing feature selection methods are difficult to effectively reduce the dimensionality when there are many strongly correlated effective feature components. This paper proposes a novel selection method for Rich Model steganalysis features. First, the separability of each feature component in the submodels of Rich Model is measured based on the Fisher criterion, and the feature components are sorted in the descending order based on the separability. Second, the correlation coefficient between any two feature components in each submodel is calculated, and feature selection is performed according to the Fisher value of each component and the correlation coefficients. Finally, the selected submodels are combined as the final steganalysis feature. The results show that the proposed feature selection method can effectively reduce the dimensionalities of JPEG domain and spatial domain Rich Model steganalysis features without affecting the detection accuracies.

The treatment of difficult-to-heal wounds remains a substantial clinical challenge due to deteriorative tissue microenvironment including the loss of extracellular matrix (ECM), excessive inflammation, impaired angiogenesis, and bacterial infection. Inspired by the chemical components, fibrous structure, and biological function of natural ECM, antibacterial and tissue environment-responsive glycopeptide hybrid hydrogel was developed for chronic wound healing. The hydrogel can facilitate the cell proliferation and macrophage polarization to M2 phenotype, and show potent antibacterial efficacy against both Gram-negative and Gram-positive bacteria. Significantly, the glycopeptide hydrogel accelerated the reconstruction of methicillin-resistant

Inactivation of the flavoenzyme-encoding gene flsO1 in fluostatin biosynthesis led to the isolation of four new angucyclinone derivatives (11, 12, 14, and 15), among which fluostarenes A (14) and B (15) featured the unprecedented 6/6/5/6/6 pentacyclic skeleton with fusion of a benzo[b]fluorene and a six-membered lactone ring. Both 14 and 15 were putatively generated via quinone methide-mediated nonenzymatic reactions. Fluostarene B (15) exhibited cytotoxicity against several cancer cell lines with IC50 values ranging from 7 to 10 μM. Fluostarenes A (14), B (15), and PK1 (16) showed α-glucosidase inhibition activity with IC50 of 0.89, 1.58, and 0.13 μM, respectively. Successful complementation of the ΔflsO1 mutant with alpK from kinamycin biosynthesis suggests that FlsO1 should function equivalently to AlpK as a putative C-5 hydroxylase.

Epoxide hydrolases (EHs) have been characterized and engineered as biocatalysts that convert epoxides to valuable chiral vicinal diol precursors of drugs and bioactive compounds. Nonetheless, the regioselectivity control of the epoxide ring opening by EHs remains challenging. Alp1U is an α/β-fold EH that exhibits poor regioselectivity in the epoxide hydrolysis of fluostatin C (compound 1) and produces a pair of stereoisomers. Herein, we established the absolute configuration of the two stereoisomeric products and determined the crystal structure of Alp1U. A Trp-186/Trp-187/Tyr-247 oxirane oxygen hole was identified in Alp1U that replaced the canonical Tyr/Tyr pair in α/β-EHs. Mutation of residues in the atypical oxirane oxygen hole of Alp1U improved the regioselectivity for epoxide hydrolysis on 1. The single site Y247F mutation led to highly regioselective (98%) attack at C-3 of 1, whereas the double mutation W187F/Y247F resulted in regioselective (94%) nucleophilic attack at C-2. Furthermore, single-crystal X-ray structures of the two regioselective Alp1U variants in complex with 1 were determined. These findings allowed insights into the reaction details of Alp1U and provided a new approach for engineering regioselective epoxide hydrolases.

Developing agricultural socialized services is of great significance for promoting agricultural sustainable development and ensuring food security. The use of the Internet provides new opportunities to promote the development of agricultural socialized services. Using data from the China Family Panel Studies (CFPS) in 2016 and 2018 with 8850 observations, this paper investigates the effects of Internet use on farmers’ adoption decision and adoption degree of agricultural socialized services, and explores the mediating effect of social networks. The adoption of agricultural socialized services is divided into adoption decision and adoption degree, and the Probit model and Tobit model are used for empirical analysis. The results showed that: (1) Internet use has a significant positive impact on both the adoption decision and the adoption degree of agricultural socialized services. Specifically, the impact of Internet use on the adoption decision and adoption degree of agricultural machinery services is greater than that of agricultural hired labor services. (2) The mechanism analysis found that social networks partially mediated the effect of Internet use on farmers’ adoption decision and adoption degree of agricultural socialized services. Furthermore, social networks have a greater mediating effect on the influence of Internet use on farmers’ adoption decision and adoption degree of agricultural machinery services compared to agricultural hired labor services. (3) The heterogeneity test found that Internet use has no significant impact on the adoption of agricultural socialized services by older farmers and farmers with a low education level. Therefore, it is crucial to fully leverage the potential of the Internet to facilitate the supply and demand of agricultural socialized services. Moreover, it is essential to integrate the market of agricultural socialized services with the rural social network to realize the synergy of “Internet plus social network”. This integration facilitates the organic connection between small farmers and modern agricultural development.

Image geolocation is an important technique for robotics and autonomous systems. The existing methods mainly extract local features from images directly and use global descriptors, which are aggregated by these local features, to retrieve candidate references from all references. Thus, the training efficiency is affected by the image noises and the accuracy is so limited that the further verification is extremely time consuming. To address these issues, this work proposes an image geolocation framework, which adds the noise filtering layer before local feature extraction. Based on this framework, an image geolocation method based on attention mechanism front loading and feature fusion is designed. In the noise filtering layer, the proposed method uses triplet attention to denoise images thus leading to higher training efficiency. In the feature aggregation layer, an improved SPP (spatial pyramid pooling) is designed to extract the local factors reflected by the position relationships among local features. Then, the local factors are incorporated with the global factors extracted by NetVLAD. The fused descriptors contain not only the statistic of the geometric elements but also the position relationships among them. The experimental results show that the proposed method outperforms NetVLAD in terms of the training convergence round and Recall@ N ( N = 1 , 5 , 10 , 20 ); especially, the convergence round of Recall@5 reduces from 25 to 10, the convergence round of Recall@10 reduces from 25 to 7, Recall@1 increases from 79.45% to 84.01%, and Recall@5 increases from 90.10% to 92.81%.

Image steganalysis has been widely studied, most of which can only complete the binary task of identifying the existence of hidden bits in an inquiry image. Currently, although some algorithms have been proposed to locate hidden bits, most of them mainly focus on the spatial domain, while usually ignoring the study of locating secret bits hidden in DCT domain for JPEG image. To address that challengeable problem, in this paper, towards two classical steganographic algorithms JSteg and F5, hiding bits in DCT domain, we propose a novel payload location method. The principal step of payload location is to estimate the cover image. We novelly propose to assign the different weights to the DCT coefficient residual in virtue of the texture of regions measured by the local variance, leading to the remarkable improvement of location results. Compared with the state of the art, the numerical experiments empirically verify that our proposed location method achieves the superior performance. In particular, when locating hidden bits in JSteg steganographic images with quality factor of 95 at the payload 0.1, the accuracy of location is remarkably improved from 46.18% to 90.22%.

In order to solve the contradiction between heating supply and demand in solar energy system in a residential area of Ordos, a solar heating system has been designed, tested, and analyzed for over a month. The main purpose of this paper is to evaluate the primary energy consumption, the carbon dioxide emissions, the initial investment, and the operation costs of the floor radiant and forced convection radiator configuration on the overall performance of the system, and analyzes its potential economic benefits. A parametric analysis has been performed in order to investigate the performance of a solar heating system integrated with dynamic automatic control system upon varying the different terminal device. Results from the present study indicate that the thermal comfort of the proposed system with forced convection radiator configuration is better than the conventional system, And the above four indices reductions from energy efficiency improvements and solar energy supply exceed over 50%.

Titanium alloy has been widely used in orthopedic surgeries as bone defect filling. However, the regeneration of high-quality new bones is limited due to the pro-inflammatory microenvironment around implants, resulting in a high occurrence rate of implant loosening or failure in osteological therapy. In this study, extracellular matrix-mimetic polysaccharide hydrogel co-delivering BMP-2 and interleukin (IL)-4 was composited with 3D printed titanium alloy to promote the osseointegration and regulate macrophage response to create a pro-healing microenvironment in bone defect. Notably, it is discovered from the bioinformatics data that IL-4 and BMP-2 could affect each other through multiple signal pathways to achieve a synergistic effect toward osteogenesis. The composite scaffold significantly promoted the osteoblast differentiation and proliferation of human bone marrow mesenchyme stem cells (hBMSCs). The repair of large-scale femur defect in rat indicated that the dual-cytokine-delivered composite scaffold could manipulate a lower inflammatory level in situ by polarizing macrophages to M2 phenotype, resulting in superior efficacy of mature new bone regeneration over the treatment of native titanium alloy or that with an individual cytokine. Collectively, this work highlights the importance of M2-type macrophages-enriched immune-environment in bone healing. The biomimetic hydrogel–metal implant composite is a versatile and advanced scaffold for accelerating in vivo bone regeneration, holding great promise in treating orthopedic diseases.

Reducing the use of chemical fertilizers in agricultural production is an inevitable requirement for achieving carbon neutrality and coping with global warming, and it is also an important measure for achieving green and sustainable agricultural development. Furthermore, the development of socialized services of green production provides a new approach to effectively reducing the use of fertilizers. Based on the survey data of 2202 rice growers in Jiangsu Province in 2021, this paper empirically analyzed the effects of socialized services of green production and social network on the reduction in fertilizer application by farmers. The results showed that both the socialized services of green production and social networks could significantly promote the reduction in fertilizer application by farmers. Social networks have a moderating effect between socialized services of green production and reduction in fertilizer application and can enhance the promotion of farmers’ adoption of socialized services of green production to reduce the application of fertilizers. With consideration of the potential endogenous problems of the model and the robustness test by replacing the key explanatory variables and the explained variables, all of the results were stable. Therefore, it is emphasized that the government should cultivate the main body of agricultural socialized services, improve the socialized service system of green production, and promote the green development of agriculture by service scale operation. Equally, it is necessary to strengthen the construction of rural social networks for the exchange of fertilization experience and give full play to the positive role of social networks in the reduction in fertilizer application by farmers.

Meroterpenoid furanasperterpene A (T2-3) with a novel 6/6/6/6/5 pentacyclic skeleton was isolated from the Aspergillus terreus GZU-31-1. Previously, we showed that T2-3 possessed significant lipid-lowering effects in 3T3-L1 adipocytes at 5 μM concentration. However, its therapeutic effect in metabolic disease and the underlying mechanisms of action remain unclear.High fat diet-induced obesity (DIO) mouse model and 3T3-L1 cell model were used to assess the anti-obesity effects of T2-3. Lipids in the adipocytes were examined by Oil Red O staining. β-catenin expression was examined by immunofluorescence and Western blotting, its activity was assessed by TOPflash/FOPflash assay.T2-3 possessed potent anti-obesity effects in DIO mice, it significantly reduced body weight and subcutaneous adipose tissue (SAT) mass. Mechanistic studies showed that T2-3 significantly inhibited 3T3-L1 preadipocyte differentiation as indicated by the reduced number of mature adipocytes. The treatments also reduced the expressions of critical adipogenic transcription factors CEBP-α and PPAR-γ in both 3T3-L1 adipocytes and SAT in DIO mice. Interestingly, T2-3 increased the cytoplasmic and nuclear expressions of β-catenin and the transcriptional activity of β-catenin in 3T3-L1 adipocytes; the elevated β-catenin expression was also observed in SAT of the T2-3-treated DIO mice. Indeed, upregulation of β-catenin activity suppressed adipogenesis, while β-catenin inhibitor JW67 reversed the anti-adipogenic effect of T2-3. Taken together, our data suggest that T2-3 inhibits adipogenesis by upregulating β-catenin activity.Our study is the first report demonstrating meroterpenoid furanasperterpene A as a novel 6/6/6/6/5 pentacyclic skeleton (T2-3) that possesses potent anti-adipogenic effect by targeting β-catenin signaling pathway. Our findings drive new anti-obesity drug discovery and provide drug leads for chemists and pharmacologists.

The intelligent production of sheet metal is a comprehensive technology involving control science, computer science, and sheet metal production. Intelligent rolling is an important development in the production process of sheet metal. In this paper, a new symmetrical four-roller bending (SFRB) process is introduced, which consists of feeding, pre-bending, reverse roll bending, second bending, and forward roll bending and unloading. A control strategy is proposed for the process, including on-line monitoring of curvature, on-line identification of the springback law, on-line prediction of final reduction, and control strategy. A convenient and reliable on-line curvature monitoring method is proposed. The quantitative relationship between the reduction and the curvature, in the form of a quadratic function, was established by physical experiments and numerical simulation, and the online identification of the springback law was realized. An on-line prediction method of the final reduction is proposed, and the determination principle of the reduction of three pre-bending processes is given. Finally, the control strategy of the SFRB process was verified by physical experiments. The relative error of the curvature radius of the final formed parts can be controlled within 0.8%. This research provides new insights into intelligent rolling.

Inactivation of the flavoenzyme-encoding gene

Cloud services have become an increasingly popular solution to provide different services to clients. More and more data are outsourced to the cloud for storage and computing. With this comes concern about the security of outsourced data. In recent years, homomorphic encryption, blockchain, steganography, and other technologies have been applied to the security and forensics of outsourced data. While encryption technologies such as homomorphic encryption and blockchain scramble data so that they cannot be understood, steganography hides the data so that they cannot be observed. Traditional steganography assumes that the environment is lossless. Robust steganography is grounded in traditional steganography and is proposed based on a real lossy social network environment. Thus, researchers, who study robust steganography, believe that the measurement should follow traditional steganography. However, the application scenario of robust steganography breaks through the traditional default lossless environment premise. It brings about changes in the focus of steganography algorithms. Simultaneously, the existing steganography methods miss the evaluation of applicability and ease of use. In this paper, “default parameters” are observed by comparing the process of robust image steganography with traditional image steganography. The idea of “perfecting default parameters” is proposed. Based on this, the attribute set of measuring robust image steganography is presented. We call it PRUDA (Payload, Robustness, ease of Use, antiDetection, and Applicability). PRUDA perfects default parameters observed in the process of traditional steganography algorithms. Statistics on image processing attacks in mobile social apps and analyses on existing algorithms have verified that PRUDA is reasonable and can better measure a robust steganography method in practical application scenarios.

Heterologous expression of the fluostatin biosynthetic gene cluster from the marine-derived Micromonospora rosaria SCSIO N160 in Streptomyces albus J1074 led to the isolation of a novel isoindolequinone albumycin (1) and a known isoquinolinequinone mansouramycin A (2). The structure of 1 was elucidated on the basis of detailed 1D and 2D NMR spectroscopic analysis. Mansouramycin A (2) is active against methicillin-resistant Staphylococcus aureus ATCC 43300, with a MIC of 8 μg ml-1, while albumycin (1) displayed negligible antibacterial activities. This study represents another example of activation of secondary metabolites that are non-relevant to the heterologously introduced biosynthetic gene cluster in a bacterial host.

It is a potential threat to persons and companies to reveal private or company-sensitive data through the Internet of Things by the color image steganography. The existing rich model features for color image steganalysis fail to utilize the fact that the content-adaptive steganography changes the pixels in complex textured regions with higher possibility. Therefore, this article proposes a variant of spatial rich model feature based on the embedding change probabilities in differential channels. The proposed feature is extracted from the residuals in the differential channels to reduce the image content information and enhance the stego signals significantly. Then, the embedding change probability of each element in the differential channels is added to the corresponding co-occurrence matrix bin to emphasize the interference of the residuals in textured regions to the improved co-occurrence matrix feature. The experimental results show that the proposed feature can significantly improve the detection performances for the WOW and S-UNIWARD steganography, especially when the payload size is small. For example, when the payload size is 0.05 bpp, the detection errors can be reduced respectively by 5.20% and 4.90% for WOW and S-UNIWARD by concatenating the proposed feature to the color rich model feature CRMQ1.

It is one of the potential threats to the Internet of Things to reveal confidential messages by color image steganography. The existing color image steganalysis algorithm based on channel geometric transformation measures owns higher accuracy than the others, but it fails to utilize the correlation between the gradient amplitudes of different color channels. Therefore, this article points out that the color image steganography weakens the correlation between the gradient amplitudes of different color channels and proposes a color image steganalysis algorithm based on channel gradient correlation. The proposed algorithm extracts the co-occurrence matrix feature from the gradient amplitude residuals among different color channels and then combines it with the existing color image steganalysis features to train the ensemble classifier for color image steganalysis. The experimental results show that, for WOW and S-UNIWARD steganography, compared with the existing algorithms, the proposed algorithm outperforms the existing algorithms.

To explore the approaches and diagnostic yield of genetic testing for renal disease in children, we describe the genotype and phenotype of the national cohort of children with renal disease from 13 different regions of China recruited from 2014 to 2018 by building up the multicenter registration system (Chinese Children Genetic Kidney Disease Database, CCGKDD). Genetic diagnosis was confirmed in 42.1% of our cohort of 1001 pediatric patients with clinical suspicion of a genetic renal disease. Of the 106 distinct monogenetic disorders detected, 15 accounted for 60.7% of genetic diagnoses. The diagnostic yield was 29.1% in steroid resistant nephritic syndrome (SRNS), 61.4% in cystic renal disease, 17.0% in congenital anomalies of the kidney and urinary tract (CAKUT), 62.3% in renal tubular disease/renal calcinosis, and 23.9% for chronic kidney disease (CKD) 3 to 5 stage with unknown origin. Genetic approaches of target gene sequence (TGS), singleton whole-exome sequencing (WES) and trio-WES were performed with diagnostic rates of 44.8%, 36.2%, and 42.6%, respectively. The early use of trio-WES could improve the diagnostic rate especially in renal tubular disease and calcinosis. We report the genetic spectrum of Chinese children with renal disease. Establishment of the CCGKDD will improve the genetic work on renal disease.

Current typical adaptive steganography algorithms take the detection resistant capability into account adequately but usually cannot extract the embedded secret messages correctly when stego images suffer from compression attack. In order to solve this problem, a framework of adaptive steganography resisting JPEG compression and detection is proposed. Utilizing the relationship between Discrete Cosine Transformation DCT coefficients, the domain of messages embedding is determined; for the maximum of the JPEG compression resistant ability, the modifying magnitude of different DCT coefficients caused by messages embedding can be determined; in order to ensure the completely correct extraction of embedded messages after JPEG compression, error correct codes are used to encode the messages to be embedded; on the basis of the current distortion functions, the distortion value of DCT coefficients corresponding to the modifying magnitude in the embedding domain can be calculated; to improve the detection resistant ability of the stego images and realize the minimum distortion embedding, syndrome-trellis codes are used to embed the encoded messages into the DCT coefficients that have a smaller distortion value. Based on the proposed framework, an adaptive steganography algorithm resisting JPEG compression and detection is designed, which utilizes the relationship between coefficients in a DCT block and the means of that in three adjacent DCT blocks. The experimental results that demonstrate the proposed algorithm not only has a good JPEG compression resistant ability but also has a strong detection resistant performance. Comparing with current J-UNIWARD steganography under quality factor 85 of JPEG compression, the extraction error rates without pre-compression decrease from about 50% to nearly 0, while the stego images remain a good detection resistant ability comparing with a typical robust watermarking algorithm, which shows the validity of the proposed framework. Copyright © 2016 John Wiley & Sons, Ltd.