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Covalent organic frameworks (COFs) are crystalline porous polymers constructed from organic building blocks into ordered two- or three-dimensional networks through dynamic covalent bonds. Attributed to their high porosity, well-defined structure, tailored functionality and excellent chemical stability, COFs have been considered ideal sorbents for various separation applications. The synthesis of COFs mainly employs the solvothermal method, which usually requires organic solvents in sealed Pyrex tubes, resulting in unscalable powdery products and environmental pollution that seriously limits their practical applications. Herein, our protocol focuses on an emerging synthesis method for COFs based on organic flux synthesis without adding solvents. The generality of this synthesis protocol has been applied in preparing various types of COFs, including olefin-linked, imide-linked, Schiff-based COFs on both gram and kilogram scales. Furthermore, organic flux synthesis avoids the disadvantages of solvothermal synthesis and enhances the crystallization and porosity of COFs. Typically, COF synthesis takes 3-5 d to complete, and subsequent washing procedures leading to pure COFs need 1 d. The procedure for kilogram-scale production of COFs with commercially available monomers is also provided. The resulting COFs are suitable for separation applications, particularly as adsorbent materials for industrial gas separation and water treatment applications. The protocol is suited for users with prior expertise in the synthesis of inorganic materials and porous organic materials.
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Metal-organic frameworks (MOFs) have shown great research and application value in various types of hydrosilylation reactions. However, studies on photocatalysis-induced hydrosilylation using MOFs are extremely rare. Metal nanoparticles (MNPs)@MOFs are extensively studied for their excellent structural tunability and photocatalytic activity, but there are few reports on their application in photocatalytic hydrosilylation. Here, a novel photocatalyst consisting of platinum (Pt) nanoparticles immobilized in a MOF framework is synthesized and used for photocatalytic hydrosilylation. The effects of various factors on hydrosilylation conversion are investigated, including catalyst concentration, substrate ratio, and irradiation intensity. Furthermore, the photoreactivity of the synthesized Pt catalyst is evaluated in the presence of different concentrations of 2-chlorothixanthone as a photosensitizer. It is noteworthy that the conversion of the reaction increases with increasing catalyst concentration or photosensitizer concentration, whereas increasing the polymethylhydrosiloxane content does not lead to a significant increase in conversion. This study demonstrates the potential of MNPs@MOFs as efficient photocatalysts for photoinduced hydrosilylation reactions and paves the way for future applications in this area.
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OBJECTIVES: Detection of early neoplastic lesions is crucial for improving the survival rates of patients with gastric cancer. Optical enhancement mode 2 is a new image-enhanced endoscopic technique that offers bright images and can improve the visibility of neoplastic lesions. This study aimed to compare the detection of neoplastic lesions with optical enhancement mode 2 and white-light imaging (WLI) in a high-risk population. METHODS: In this prospective multicenter randomized controlled trial, patients were randomly assigned to optical enhancement mode 2 or WLI groups. Detection of suspicious neoplastic lesions during the examinations was recorded, and pathological diagnoses served as the gold standard. RESULTS: A total of 1211 and 1219 individuals were included in the optical enhancement mode 2 and WLI groups, respectively. The detection rate of neoplastic lesions was significantly higher in the optical enhancement mode 2 group (5.1% vs. 1.9%; risk ratio, 2.656 [95% confidence interval, 1.630-4.330]; p < 0.001). The detection rate of neoplastic lesions with an atrophic gastritis background was significantly higher in the optical enhancement mode 2 group (8.6% vs. 2.6%, p < 0.001). The optical enhancement mode 2 group also had a higher detection rate among endoscopists with different experiences. CONCLUSIONS: Optical enhancement mode 2 was more effective than WLI for detecting neoplastic lesions in the stomach, and can serve as a new method for screening early gastric cancer in clinical practice. CLINICAL REGISTRY: United States National Library of Medicine (https://www. CLINICALTRIALS: gov), ID: NCT040720521.
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Detección Precoz del Cáncer , Gastroscopía , Aumento de la Imagen , Neoplasias Gástricas , Humanos , Neoplasias Gástricas/diagnóstico por imagen , Neoplasias Gástricas/patología , Neoplasias Gástricas/diagnóstico , Masculino , Femenino , Persona de Mediana Edad , Estudios Prospectivos , Gastroscopía/métodos , Detección Precoz del Cáncer/métodos , Anciano , Aumento de la Imagen/métodos , Gastritis Atrófica/diagnóstico , Gastritis Atrófica/patología , Gastritis Atrófica/diagnóstico por imagen , AdultoRESUMEN
A long-standing topic in artificial intelligence is the effective recognition of patterns from noisy images. In this regard, the recent data-driven paradigm considers 1) improving the representation robustness by adding noisy samples in training phase (i.e., data augmentation) or 2) pre-processing the noisy image by learning to solve the inverse problem (i.e., image denoising). However, such methods generally exhibit inefficient process and unstable result, limiting their practical applications. In this paper, we explore a non-learning paradigm that aims to derive robust representation directly from noisy images, without the denoising as pre-processing. Here, the noise-robust representation is designed as Fractional-order Moments in Radon space (FMR), with also beneficial properties of orthogonality and rotation invariance. Unlike earlier integer-order methods, our work is a more generic design taking such classical methods as special cases, and the introduced fractional-order parameter offers time-frequency analysis capability that is not available in classical methods. Formally, both implicit and explicit paths for constructing the FMR are discussed in detail. Extensive simulation experiments and robust visual applications are provided to demonstrate the uniqueness and usefulness of our FMR, especially for noise robustness, rotation invariance, and time-frequency discriminability.
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The growing prevalence of lithium (Li) batteries has drawn public attention to Li as an emerging pollutant. The present study investigates the toxicity of Li+ on Chromochloris zofingiensis, examining physiological, biochemical and omics aspects. Results reveal hormesis effects of Li+ on C. zofingiensis growth. At Li+ concentrations below 5 mg L-1, Li+ can enhance chlorophyll content, mitochondrial activity, and antioxidant capacity, leading to increased dry cell weight and cell number. Conversely, when it exceeded 10 mg L-1, Li+ can reduce chlorophyll content, induce oxidative stress, and disrupt chloroplast and mitochondria structure and function, ultimately impeding cell growth. In addition, under 50 mg L-1 Li+ stress, microalgae optimize absorbed light energy use (increasing Fv/Fm and E TR ) and respond to stress by up-regulating genes in starch and lipid biosynthesis pathways, promoting the accumulation of storage components. Weighted gene co-expression network analysis indicates that peptidylprolyl cis/trans isomerase, GTPase and L-ascorbate oxidase might be the key regulators in response to Li+ stress. This research marks the toxic effects and molecular mechanisms of Li+ on freshwater microalga, which would improve our understanding of Li's toxicology and contributing to the establishment of Li pollution standards.
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Chlorophyceae , Microalgas , Antioxidantes/metabolismo , Microalgas/metabolismo , Litio/toxicidad , Fotosíntesis , Clorofila/metabolismo , Chlorophyceae/metabolismoRESUMEN
The significant advancement in deep learning has made it feasible to extract gender from faces accurately. However, such unauthorized extraction would pose potential threats to individual privacy. Existing protection schemes for gender privacy have exhibited satisfactory performance. Nevertheless, they suffer from gender inference from gender-related attributes and fail to support the recovery of the original image. In this paper, we propose a novel gender privacy protection scheme that aims to enhance gender privacy while supporting reversibility. Firstly, our scheme utilizes continuously optimized adversarial perturbations to prevent gender recognition from unauthorized classifiers. Meanwhile, gender-related attributes are concealed for classifiers, which prevents the inference of gender from these attributes, thereby enhancing gender privacy. Moreover, an identity preservation constraint is added to maintain identity preservation. Secondly, reversibility is supported by a reversible image transformation, allowing the perturbations to be securely removed to losslessly recover the original face when required. Extensive experiments demonstrate the effectiveness of our scheme in gender privacy protection, identity preservation, and reversibility.
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Relaciones Interpersonales , Privacidad , Reconocimiento en PsicologíaRESUMEN
BACKGROUND: The induction of lipid and astaxanthin accumulation in microalgae is often achieved through abiotic stress. However, this approach usually leads to oxidative stress, which results in relatively low growth rate. Phytohormones, as important small molecule signaling substances, not only affect the growth and metabolism of microalgae but also influence the intracellular reactive oxygen species level. This study aimed to screen phytohormones that could promote the fatty acids and astaxanthin yield of heterotrophic Chromochloris zofingiensis without causing oxidative damage, and further investigate the underlying mechanisms. RESULTS: In the present study, among all the selected phytohormones, the addition of exogenous salicylic acid (SA) could effectively promote cell growth along with the yield of total fatty acids (TFA) and astaxanthin in heterotrophic C. zofingiensis. Notably, the highest yields of TFA and astaxanthin were achieved at 100 µM SA, 43% and 97.2% higher compared with the control, respectively. Interestingly, the intracellular reactive oxygen species (ROS) levels, which are usually increased with elevated TFA content under abiotic stresses, were significantly decreased by SA treatment. Comparative transcriptome analysis unveiled significant alterations in overall carbon metabolism by SA. Specifically, the upregulation of fatty acid synthesis pathway, upregulation of ß-carotene-4-ketolase (BKT) in carotenoid synthesis aligned with biochemical findings. Weighted gene co-expression network analysis highlighted ABC transporters and GTF2B-like transcription factor as potential key regulators. CONCLUSION: This study found that salicylic acid can serve as an effective regulator to promote the celling growth and accumulation of fatty acids and astaxanthin in heterotrophic C. zofingiensis without ROS elevation, which provides a promising approach for heterotrophic production of TFA and astaxanthin without growth inhibition.
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BACKGROUND: Child maltreatment can increase the risk of lifetime non-suicidal self-injury (NSSI) and suicidal self-injury (SSI), but there is limited knowledge regarding the differences of potentially psychological mechanisms between NSSI with and without SSI. METHODS: Participants, 3918 community-based Chinese young men aged 18-34 years in Chengdu, were included in this study. We investigated the association between depression, anxiety, psychosis, child maltreatment, adulthood traumatic events, impulsivity, alcohol dependence, drug abuse, and lifetime of NSSI among participants with and without SSI. Parallel mediation analysis was utilized to explore the mediators for the relation between child maltreatment and NSSI. RESULTS: The prevalence of lifetime NSSI was 6.1 % (95 % CI: 5.4 %-6.9 %) among young men. Anxiety and impulsivity partially mediated the effect of child maltreatment on NSSI either with (indirect effect: 51.2 %) or without SSI (indirect effect: 34.3 %). Depression was independently and significantly associated with only NSSI but not with NSSI+SSI. Alcohol dependence and psychosis were independently and significantly associated with NSSI+SSI and mediated the effect of child maltreatment on NSSI+SSI. LIMITATIONS: The cross-sectional survey data limits the robustness of the proof to the causal relationships. CONCLUSIONS: Anxiety and impulsivity are associated with NSSI either with or without SSI and partially mediate the effect of child maltreatment on NSSI. Depression is associated with only NSSI, while alcohol dependence and psychosis are only associated with NSSI+SSI. It could be crucial to improve treatment and recovery of alcohol dependence and psychosis for preventing young men engaged in NSSI from attempting SSI.
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Experiencias Adversas de la Infancia , Alcoholismo , Conducta Autodestructiva , Adulto , Humanos , Masculino , Ansiedad/epidemiología , Ansiedad/psicología , Estudios Transversales , Conducta Impulsiva , Factores de Riesgo , Conducta Autodestructiva/epidemiología , Conducta Autodestructiva/psicología , Ideación Suicida , Adolescente , Adulto JovenRESUMEN
Cadmium, an environmental pollutant, is highly toxic and resistant to degradation. It exhibits toxicity at elevated doses but triggers excitatory effects at low doses, a phenomenon referred to as hormesis. Microalgae, as primary producers in aquatic ecosystems, demonstrate hormesis induced by cadmium, though the specific mechanisms are not yet fully understood. Consequently, we examined the hormesis of cadmium in Chromochloris zofingiensis. A minimal Cd2+ concentration (0.05 mg L-1) prompted cell proliferation, whereas higher concentrations (2.50 mg L-1) inhibited growth. The group exposed to higher doses exhibited increased levels of reactive oxygen species (ROS), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT). Contrastingly, the group exposed to low doses exhibited a moderate antioxidant response without significantly increasing ROS. This implies that increased levels of antioxidative components counteract excessive ROS, maintaining cellular redox balance and promoting growth under conditions of low Cd2+. Validation experiments have established that NADPH oxidase-derived ROS primarily coordinates the hormesis effect in microalgae. Comparative transcriptome analysis has proved the involvement of antioxidant systems and photosynthesis in regulating hormesis. Notably, Aurora A kinases consistently displayed varying expression levels across all Cd2+ treatments, and their role in microalgal hormesis was confirmed through validation with SNS-314 mesylate. This study unveils the intricate regulatory mechanisms of Cd-induced hormesis in C. zofingiensis, with implications for environmental remediation and industrial microalgae applications.
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Antioxidantes , Microalgas , Antioxidantes/metabolismo , Cadmio/análisis , Especies Reactivas de Oxígeno/metabolismo , Hormesis , Ecosistema , Fotosíntesis , Glutatión/metabolismo , Superóxido Dismutasa/metabolismoRESUMEN
Numerous studies have extensively examined the risk factors associated with suicidal ideation (SI). Nevertheless, there has been a dearth of research analyzing the potential positive factors, such as attachment and cognitive flexibility, that might contribute to a reduction in SI and facilitate more effective interventions. This study aimed to investigate the chain-mediating effects of attachment and cognitive flexibility on the family atmosphere and SI. Data were collected from 856 (range = 18-28 years old, 240 males) emerging adults who completed the Family Atmosphere Scale, the Relationship Questionnaire, the Cognitive Flexibility Scale, and the Self-rated Ideation of Suicide Scale. The findings revealed that the family atmosphere not only exerted a direct influence on SI but also operated through a chain-mediation mechanism involving fearful attachment and cognitive control flexibility. This study concludes that fearful attachment and cognitive control flexibility may mediate the impact of a negative family atmosphere on SI.
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BACKGROUND/OBJECTIVE: People living with HIV (PLWH) are prone to mental health problems and evidence indicates that HIV-related stigma can negatively impact mental health-related quality of life. This study explored potential mechanisms between HIV-related stigma and mental health-related quality of life, specifically whether anxiety or depression mediates, and whether social support moderates, the relationship. METHOD: A total of 1197 Chinese PLWH participated in the study. The Berger HIV Stigma Scale, the Hospital Anxiety and Depression Scale (HADS), the 12-item Brief Health Survey (SF-12), and the Multidimensional Scale of Perceived Social Support (MSPSS) were employed. RESULTS: HIV-related stigma was negatively associated with mental health-related quality of life. Anxiety and depression partially mediated the relationship between HIV-related stigma and mental health-related quality of life; social support played a moderating role. CONCLUSIONS: The mental health-related quality of life in PLWH was shown to be indirectly affected by HIV-related stigma through anxiety and depression in China. The negative impact of HIV-related stigma decreased with increased social support.
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Ansiedad , Depresión , Infecciones por VIH , Calidad de Vida , Estigma Social , Humanos , Estudios Transversales , Pueblos del Este de Asia , Infecciones por VIH/complicaciones , Infecciones por VIH/psicología , Apoyo SocialRESUMEN
As an important organ of the human body, effective protection of the skin during trauma is crucial. An ideal wound dressing should have adhesion, adsorption of wound secretions, and good antibacterial properties. Two kinds of natural polysaccharide-based hydrogels, carboxyethyl chitosan/oxidized pectin hydrogel (CEC/OP) and carboxyethyl chitosan/oxidized pectin/polyethyleneimine hydrogel (CEC/OP/PEI), were reported by using carboxyethyl chitosan as the matrix, and oxidized pectin and branched polyethyleneimine as the crosslinking agents. Both hydrogels could be formed in a short time and exhibited the pH responsively due to the presence of imine bond. Compared with carboxyethyl chitosan/oxidized pectin hydrogel, polyethyleneimine containing hydrogel can form gel quickly, a more compact and stable three-dimensional space network structure was formed, which exhibited better swelling performance, the swelling ration, rheology property, self-repair ability, and antibacterial performance. When the mass fractions of carboxyethyl chitosan and oxidized pectin solutions are 4 wt% and 9 wt%, respectively, the hydrogel exhibited an antibacterial efficiency of >96 % against both Staphylococcus aureus and Escherichia coli. After adding 0.75 wt% polyethyleneimine, the antibacterial efficiency of hydrogel could reach up to >98 %. More importantly, the polyethyleneimine containing hydrogel has a significant effect in the treatment of bacterially infected wounds.
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Quitosano , Hidrogeles , Humanos , Hidrogeles/farmacología , Hidrogeles/química , Quitosano/farmacología , Quitosano/química , Cicatrización de Heridas , Pectinas/farmacología , Pectinas/química , Polietileneimina , Antibacterianos/farmacología , Antibacterianos/química , Concentración de Iones de HidrógenoRESUMEN
One-step adsorptive purification of ethylene (C2H4) from a ternary mixture of acetylene (C2H2), C2H4, and ethane (C2H6) by a single material is of great importance but challenging in the petrochemical industry. Herein, a chemically robust olefin-linked covalent organic framework (COF), NKCOF-62, is designed and synthesized by a melt polymerization method employing tetramethylpyrazine and terephthalaldehyde as cheap monomers. This method avoids most of the disadvantages of classical solvothermal methods, which enable the cost-effective kilogram fabrication of olefin-linked COFs in one pot. Furthermore, NKCOF-62 shows remarkably selective adsorption of C2H2 and C2H6 over C2H4 thanks to its unique pore environments and suitable pore size. Breakthrough experiments demonstrate that polymer-grade C2H4 can be directly obtained from C2H2/C2H6/C2H4 (1/1/1) ternary mixtures through a single separation process. Notably, NKCOF-62 is the first demonstration of the potential to use COFs for C2H2/C2H6/C2H4 separation, which provides a blueprint for the design and construction of robust COFs for industrial gas separations.
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The Characterization and anticancer effects of extracellular polysaccharide (EPS) from DHA-producing microalga Crypthecodinium sp. SUN were studied in the present research. Results showed that EPS from C. sp. SUN have a molecular weight of 1.118 × 106 g/mol. EPS significantly inhibited the proliferation and migration of LA795 lung adenocarcinoma cells, and the apoptosis rate decreased in a concentration-dependent manner, reached 52 % at 15 mg/mL. C. sp. SUN EPS also significantly decreased reactive oxygen species (ROS) level by over 50 %, superoxide dismutase (SOD) activity by 76 %, and catalase (CAT) activity by 34 % at 10 mg/mL, indicating that EPS may inhibit tumor cell growth instead of killing tumor cells. Additionally, C. sp. SUN EPS suppressed cell proliferation by downregulating the expression of adhesion proteins and cyclin D1 in LA795 cells. In vivo experiments demonstrated that C. sp. SUN EPS inhibited the growth of lung adenocarcinoma tumors without affecting the normal body weight of nude mice. Collectively, the present study showed that C. sp. SUN EPS could be a potential substance for cancer treatment, which provided a research basis for future study on EPS and expanded the application of Crypthecodinium.
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Adenocarcinoma del Pulmón , Microalgas , Animales , Ratones , Microalgas/metabolismo , Ratones Desnudos , Polisacáridos/farmacología , Polisacáridos/metabolismo , Proliferación CelularRESUMEN
Covalent organic frameworks (COFs) with high specific porosity, easy functionalization, and tailored structure are an emerging class of crystalline porous polymers that have been extensively exploited as ideal materials in various fields. Among them, sp2-carbon linked COFs with high chemical stability, porous backbone, and unique π-electron conjugated architectures structure have raised widespread attention. Specifically, the porous channels of olefin-linked COFs could be packed with active sites for catalysis and guest molecules, while π-π stacking interactions and conjugation systems pave the way for electron transfer. In recent years, many efforts have been devoted to the development of sp2-carbon linked COFs for applications in catalysis, energy storage, gas adsorption, and separation. In this review, we highlight the design principles, synthesis strategies, and impactful applications of olefin-linked COFs. We are looking forward to this review to deepen the understanding of the synthesis of olefin-linked COFs and motivate the further development of these novel conjugated organic materials with distinctive physicochemical properties, as well as their applications in a variety of fields.
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Current 3D mesh steganography algorithms relying on geometric modification are prone to detection by steganalyzers. In traditional steganography, adaptive steganography has proven to be an efficient means of enhancing steganography security. Taking inspiration from this, we propose a highly adaptive embedding algorithm, guided by the principle of minimizing a carefully crafted distortion through efficient steganography codes. Specifically, we tailor a payload-limited embedding optimization problem for 3D settings and devise a feature-preserving distortion (FPD) to measure the impact of message embedding. The distortion takes on an additive form and is defined as a weighted difference of the effective steganalytic subfeatures utilized by the current 3D steganalyzers. With practicality in mind, we refine the distortion to enhance robustness and computational efficiency. By minimizing the FPD, our algorithm can preserve mesh features to a considerable extent, including steganalytic and geometric features, while achieving a high embedding capacity. During the practical embedding phase, we employ the Q-layered syndrome trellis code (STC). However, calculating the bit modification probability (BMP) for each layer of the Q-layered STC, given the variation of Q, can be cumbersome. To address this issue, we design a universal and automatic approach for the BMP calculation. The experimental results demonstrate that our algorithm achieves state-of-the-art performance in countering 3D steganalysis.
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In the research of multi-image encryption (MIE), the image type and size are important factors that limit the algorithm design. For this reason, the multi-image (MI) hybrid encryption algorithm that can flexibly encrypt color images and grayscale images of various sizes is proposed. Based on this, combining the back propagation (BP) neural network compression technology and the MI hybrid encryption algorithm, an MI hybrid compression-encryption (MIHCE) scheme can be obtained to reduce the pressure of simultaneous transmission and storage of multiple cipher images. Besides, two chaotic maps are used in the scheme design process. By plotting the phase diagrams under different parameter conditions, the rich variation of the behavior of the chaotic maps in the phase space is exhibited. The MIHCE scheme based on the chaotic maps consists of three parts: 1) compressing the MI cube by using the BP neural network; 2) scrambling the compressed MI cube based on the knight tour problem and chaotic sequences; and 3) diffusing the scrambled MI cube. After the MIHCE is completed, the obtained cipher images are stored and transmitted. Subsequently, the security analysis and compression performance analysis prove the feasibility and safety of the designed compression-encryption scheme.
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Restoring missing areas without leaving visible traces has become a trivial task with Photoshop inpainting tools. However, such tools have potentially illegal or unethical uses, such as removing specific objects in images to deceive the public. Despite the emergence of many forensics methods of image inpainting, their detection ability is still insufficient when attending to professional Photoshop inpainting. Motivated by this, we propose a novel method termed primary-secondary network (PS-Net) to localize the Photoshop inpainted regions in images. To the best of our knowledge, this is the first forensic method devoted specifically to Photoshop inpainting. The PS-Net is designed to deal with the problems of delicate and professional inpainted images. It consists of two subnetworks: the primary network (P-Net) and the secondary network (S-Net). The P-Net aims at mining the frequency clues of subtle inpainting features through the convolutional network and further identifying the tampered region. The S-Net enables the model to mitigate compression and noise attacks to some extent by increasing the co-occurring feature weights and providing features that are not captured by the P-Net. Furthermore, the dense connection, Ghost modules, and channel attention blocks (C-A blocks) are adopted to further strengthen the localization ability of PS-Net. Extensive experimental results illustrate that PS-Net can successfully distinguish forged regions in elaborate inpainted images, outperforming several state-of-the-art solutions. The proposed PS-Net is also robust against some postprocessing operations commonly used in Photoshop.
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Soil moisture content (SWC) can change the diversity and composition of soil fungal communities by affecting soil texture and soil nutrients. To explore the response of soil fungal communities to moisture in the grassland ecosystem on the south shore of Hulun Lake, we set up a natural moisture gradient that was subdivided into high (HW), medium (MW), and low (LW) water contents. Vegetation was investigated by quadrat method, and aboveground biomass was collected by the mowing method. Soil physicochemical properties were obtained by internal experiments. The composition of the soil fungal community was determined using high-throughput sequencing technology. The results showed significant differences in soil texture, nutrients, and fungal species diversity under the moisture gradients. Although there was significant clustering of fungal communities in different treatments, the fungal community composition was not significantly different. According to the phylogenetic tree, the Ascomycota and Basidiomycota were the most important branches. The fungal species diversity was smaller when SWC was higher, and in this environment (HW), the fungal-dominant species were significantly related to SWC and soil nutrients. At this time, soil clay formed a protective barrier for the survival of the dominant classes Sordariomycetes and Dothideomycetes and increased their relative abundance. In summary, the fungal community responded significantly to SWC on the southern shore of the Hulun Lake ecosystem in Inner Mongolia, China, and the fungal community composition of the HW group was stable and easier to survive.
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Controllable modulation of the stacking modes of 2D (two-dimensional) materials can significantly influence their properties and functionalities but remains a formidable synthetic challenge. Here, an effective strategy is proposed to control the layer stacking of imide-linked 2D covalent organic frameworks (COFs) by altering the synthetic methods. Specifically, a modulator-assisted method can afford a COF with rare ABC stacking without the need for any additives, while solvothermal synthesis leads to AA stacking. The variation of interlayer stacking significantly influences their chemical and physical properties, including morphology, porosity, and gas adsorption performance. The resultant COF with ABC stacking shows much higher C2 H2 capacity and selectivity over CO2 and C2 H4 than the COF with AA stacking, which is not demonstrated in the COF field yet. Furthermore, the outstanding practical separation ability of ABC stacking COF is confirmed by breakthrough experiments of C2 H2 /CO2 (50/50, v/v) and C2 H2 /C2 H4 (1/99, v/v), which can selectively remove C2 H2 with good recyclability. This work provides a new direction to produce COFs with controllable interlayer stacking modes.