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The intermolecular [4 + 2] cycloaddition of o-hydroxy benzyl alcohols with isochroman ketals was realized by CF3CO2H catalysis. A broad range of bisbenzannulated [6,6]-spiroketals were formed under the metal-free mild conditions in moderate to excellent yields (45-98%) with mostly excellent diastereoselectivities (up to >20 : 1 dr). Furthermore, the enantioselective version was also preliminarily investigated and the bisbenzannulated [6,6]-spiroketal was obtained with 61% ee in the presence of Sc(OTf)3/Feng's chiral N,N'-dioxide ligand. Some of the bisbenzannulated [6,6]-spiroketal products showed good in vitro antifungal activities against Sclerotinia sclerotiorum and Rhizoctonia solani.
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Mechanical thrombectomy (MT) has become an effective re-airway method for cerebral ischemia-reperfusion injury (CI/RI). However, at present, there are few studies on the impact of MT therapy on the prognosis of CI/RI patients at home and abroad. Therefore, this paper aims to analyze the relevant factors affecting the prognosis of CI/RI patients after MT therapy. The main regulatory miRNAs during CI/RI in patients with MT were screened and studied. Serums were obtained from 80 patients (moderate to severe stroke) who underwent MT. Clinical information was recorded using a unified standard questionnaire. According to the modified Rankin Scale, the patients were divided into a good prognosis group and a poor prognosis group. The clinical data were compared respectively, and univariate and multivariate Logistic regression analysis was performed. ROC curves were drawn, and Kaplan-Merier method determined whether different NIHSS scores at admission had any difference in the in-hospital survival rate of CI/RI patients treated with MT. miRNAs in serum were detected and screened out. Cell and animal models were established, in which miRNAs and apoptotic molecules were detected. miRNA target genes were predicted, and the mechanism of miRNA regulation of apoptosis was verified. Gender, smoking, drinking, diabetes, hypertension, hyperlipidemia, age, and alcohol consumption suggested no difference in the two groups. The rates of smoking history, diabetes, hypertension, and hyperlipidemia in the poor prognosis group were higher than those in the good prognosis group. Smoking and diabetes were independent risk factors for poor prognosis. miR-127-5p expression in CI/RI patients with poor prognosis was higher than that in those with good prognosis. miR-127-5p expression was also elevated in both cell and animal models. Cell apoptosis was weakened after miR-127-5p knockdown, and tissue infarction in animal models was also reduced. FAIM2 was a target gene of miR-127-5p. silencing FAIM2 enhanced apoptosis after miR-127-5p knockdown. miR-127-5p/FAIM2 axis can be a new strategy to treat and prevent brain injury in CI/RI patients treated with MT.
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Isquemia Encefálica , Diabetes Mellitus , Hiperlipidemias , Hipertensão , MicroRNAs , Traumatismo por Reperfusão , Animais , Humanos , Traumatismo por Reperfusão/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Infarto Cerebral , Isquemia Encefálica/genética , Apoptose/genética , Proteínas de Membrana , Proteínas Reguladoras de ApoptoseRESUMO
BACKGROUND: Chronic inflammation has been connected by epidemiological evidence to coronary artery disease (CAD) along with myocardial infarction (MI). Nevertheless, it is still unclear whether reverse causality or confounders account for these connections. Our objectives are to examine the causality between inflammatory cytokines and CAD/MI as well as the potential mediating influence of lipid characteristics. METHODS: We acquired instrumental variables through genome-wide association studies meta-analyses of 41 inflammatory cytokines (8293 individuals). Genetic associations with CAD (122 733 cases and 424 528 controls), MI (~61 505 cases and 577 716 controls) and five candidate lipid mediators were obtained from the corresponding genome-wide association studies. A two-step, two-sample Mendelian randomization analysis was applied, followed with comprehensive sensitivity analyses. RESULTS: Genetically determined growth regulated oncogene-α was causally linked to a decreased incidence of CAD [odds ratio (OR), 0.97; 95% confidence interval (CI), 0.95-0.99; P = .007] and MI (OR, 0.95; 95% CI, 0.92-0.98; P = .002). There is suggestive evidence indicating a causal impact of macrophage inflammatory protein-1ß upon CAD (OR, 1.04; 95% CI, 1.01-1.07; P = .010) and MI (OR, 1.07; 95% CI, 1.02-1.11; P = .002). Furthermore, we discovered suggestive causal connections between tumor necrosis factor-related apoptosis-inducing ligand and CAD (OR, 0.97; 95% CI, 0.95-1.00; P = .020). Two-step Mendelian randomization analysis revealed that triglycerides partially mediate the effect of growth regulated oncogene-α on CAD (proportion-mediated: 13.28%) and MI (8.05%). CONCLUSIONS: We provided novel genetic evidence supporting the causality of inflammatory cytokines on CAD/MI and elucidate the mediating effect of triglycerides in the causal pathways linking inflammatory cytokines and CAD/MI.
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Doença da Artéria Coronariana , Citocinas , Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Infarto do Miocárdio , Humanos , Doença da Artéria Coronariana/genética , Infarto do Miocárdio/genética , Citocinas/metabolismo , Citocinas/genética , Inflamação/genética , Predisposição Genética para Doença , Lipídeos/sangue , Polimorfismo de Nucleotídeo ÚnicoRESUMO
Recently, consumers have become increasingly interested in natural, health-promoting, and chronic disease-preventing medicine and food homology (MFH). There has been accumulating evidence that many herbal medicines, including MFH, are biologically active due to their biotransformation through the intestinal microbiota. The emphasis of scientific investigation has moved from the functionally active role of MFH to the more subtle role of biotransformation of the active ingredients in probiotic-fermented MFH and their health benefits. This review provides an overview of the current status of research on probiotic-fermented MFH. Probiotics degrade toxins and anti-nutritional factors in MFH, improve the flavor of MFH, and increase its bioactive components through their transformative effects. Moreover, MFH can provide a material base for the growth of probiotics and promote the production of their metabolites. In addition, the health benefits of probiotic-fermented MFH in recent years, including antimicrobial, antioxidant, anti-inflammatory, anti-neurodegenerative, skin-protective, and gut microbiome-modulating effects, are summarized, and the health risks associated with them are also described. Finally, the future development of probiotic-fermented MFH is prospected in combination with modern development technologies, such as high-throughput screening technology, synthetic biology technology, and database construction technology. Overall, probiotic-fermented MFH has the potential to be used in functional food for preventing and improving people's health. In the future, personalized functional foods can be expected based on synthetic biology technology and a database on the functional role of probiotic-fermented MFH.
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Anti-Infecciosos , Alimentos Fermentados , Probióticos , Humanos , Alimento Funcional , AntioxidantesRESUMO
Members of Bifidobacterium are among the first microbes to colonize the human intestine naturally, their abundance and diversity in the colon are closely related to host health. Recently, the gut microbiota has been gradually proven to be crucial mediators of various metabolic processes between the external environment and the host. Therefore, the health-promoting benefits of Bifidobacterium spp. and their applications in food have gradually been widely concerned. The main purpose of this review is to comprehensively introduce general features, colonization methods, and safety of Bifidobacterium spp. in the human gut, highlighting its health benefits and industrial applications. On this basis, the existing limitations and scope for future research are also discussed. Bifidobacteria have beneficial effects on the host's digestive system, immune system, and nervous system. However, the first prerequisite for functioning is to have enough live bacteria before consumption and successfully colonize the colon after ingestion. At present, strain breeding, optimization (e.g., selecting acid and bile resistant strains, adaptive evolution, high cell density culture), and external protection technology (e.g., microencapsulation and protectants) are the main strategies to address these challenges in food application.
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Microbioma Gastrointestinal , Probióticos , Humanos , Bifidobacterium/metabolismo , Alimento FuncionalRESUMO
Numerous studies have indicated enrichment of circular RNA (circRNA) in the brain takes on a momentous role in cerebral ischemia-reperfusion (CIR) injury. A recent study discovered a novel circCRIM1, was highly expressed in the middle cerebral artery occlusion-reperfusion (MCAO/R) model. Nevertheless, its specific biological function remained unknown. The study was to explore circCRIM1 in CIR-induced neuronal apoptosis. As measured, circCRIM1 and TXNIP were up-regulated, while miR-141-3p was down-regulated in MCAO/R mouse model and OGD/R SH-SY5Y cells. Depleting circCRIM1 reduced the number of apoptotic neurons in MCAO/R rats, increased the number of Nissl bodies, prevented reactive oxygen species production and oxidative stress imbalance in brain tissues, repressed cleaved caspase-3, Bax, and Cyto C protein levels and increased Bcl-2 levels. Overexpression of circCRIM1 further repressed neuronal activity and accelerated apoptosis in OGD/R model, disrupted redox balance. Depleting circCRIM1 had the opposite effect in OGD/R model. Knocking down miR-141-3p or TXNIP weakened the effects of knocking down circCRIM1 or overexpressing circCRIM1, separately. Mechanistically, circCRIM1 exerted an active role in CIR injury via miR-141-3p to mediate TXNIP. All in all, the circCRIM1/miR-141-3p/TXNIP axis might be a latent therapeutic target for CIR injury.
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Isquemia Encefálica , MicroRNAs , Neuroblastoma , Traumatismo por Reperfusão , Camundongos , Humanos , Ratos , Animais , MicroRNAs/genética , MicroRNAs/metabolismo , Isquemia Encefálica/genética , Isquemia Encefálica/metabolismo , Reperfusão , Infarto da Artéria Cerebral Média/genética , Infarto da Artéria Cerebral Média/metabolismo , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/metabolismo , Apoptose/genética , Tiorredoxinas/genética , Glucose/metabolismo , Proteínas de Ciclo CelularRESUMO
With the rapid advancement of network communication and big data technologies, the Internet of Things (IoT) has permeated every facet of our lives. Meanwhile, the interconnected IoT devices have generated a substantial volume of data, which possess both economic and strategic value. However, owing to the inherently open nature of IoT environments and the limited capabilities and the distributed deployment of IoT devices, traditional access control methods fall short in addressing the challenges of secure IoT data management. On the one hand, the single point of failure issue is inevitable for the centralized access control schemes. On the other hand, most decentralized access control schemes still face problems such as token underutilization, the insecure distribution of user permissions, and inefficiency.This paper introduces a blockchain-based access control framework to address these challenges. Specifically, the proposed framework enables data owners to host their data and achieves user-defined lightweight data management. Additionally, through the strategic amalgamation of smart contracts and hash-chains, our access control scheme can limit the number of times (i.e., n-times access) a user can access the IoT data before the deadline. This also means that users can utilize their tokens multiple times (predefined by the data owner) within the deadline, thereby improving token utilization while ensuring strict access control. Furthermore, by leveraging the intrinsic characteristics of blockchain, our framework allows data owners to gain capabilities for auditing the access records of their data and verifying them. To empirically validate the effectiveness of our proposed framework and approach, we conducted extensive simulations, and the experimental results demonstrated the feasibility and efficiency of our solution.
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BACKGROUND: Great efforts have been made to improve the oral bioaccessibility of lipophilic ingredients with multi-functionalities. Achieving intestinal delivery of lipophilic ingredients and their encapsulation in micelles composed of bile salts and lipid hydrolysates (i.e. fatty acids) is critical for improving oral bioaccessibility. Therefore, oil-core microcapsules are considered ideal carriers of lipophilic ingredients. Previous studies have reported oil-core/zein-shell microcapsules constructed by a one-step anti-solvent process. Still, its efficacy as an intestinal delivery system was limited because if the porous shell structure. RESULTS: Zein solution was pretreated with ultrasound and tannic acid (TA) cross-linking. Composite oil-core microcapsule (COM) with a compact shell structure was successfully prepared by using modified zein solution in the anti-solvent process. Fourier-transform infrared spectroscopy and circular dichroism analyses indicated that ultrasound and TA synergistically promote the conformational transition of zein from α-helix to ß-sheet and enhance the hydrophobic interactions among protein chains. The above changes contribute to the strengthen of shell zein network. Correspondingly, COM presents superior encapsulation efficiency and environmental stability over the simple oil-core microcapsule (SOM) prepared without the use of ultrasound and TA. Furthermore, antioxidant activity of ß-carotene was well retained during the encapsulation process. In vitro studies indicated that COM was more resistant to digestibility and acid-induced swelling. More than 87% of ß-carotene could be released in the intestine in a sustainable way. The controllable release behavior thus promoted a significant increase in bioaccessibility of ß-carotene encapsulated in COM compared to SOM (85.9% versus 48.5%). CONCLUSION: The COM generated here shows potential for bioaccessibility improvement of lipophilic ingredients. © 2022 Society of Chemical Industry.
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Zeína , Cápsulas , Zeína/química , beta Caroteno/química , Micelas , Intestinos , SolventesRESUMO
The assembly of biomolecules and ions (e.g., biomineralization process) generates many intricate structures in nature. However, human beings' control over the assembly processes of ions is in its infant stage compared with nature. Here, it is reported that the intermediate valence metal ions in the electrolyte can influence the growth speed of certain crystal facets and in turn adjust the shape of the electrodeposits created by anodic electrodeposition. This is because the intermediate valence metal ions (e.g., Pb2+ , Mn2+ , etc.) can be oxidized by the electrochemically oxidized high valence ions (e.g., Ag2+ and Ag3+ ). Therefore, the concentration of the electrochemically oxidized high valence ions can be controlled by the intermediate valence ions, affecting the growth kinetics of the electrodeposits. Taking the anodic electrodeposition of Ag7 O8 NO3 as an example, the role of intermediate valence ions in tailoring the shape of the Ag7 O8 NO3 electrodeposits is demonstrated. Moreover, the growth location of the second-order structure can be controlled by the intermediate valence metal ions. Additionally, the designed complex microarchitectures starting from certain crystal facets to form hollow nanoframes can be selectively etched. The control capability over the electrochemical assembly process of metal ions is significantly strengthened by introducing intermediate valence ions into the electrolyte.
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Galvanoplastia , Metais , Humanos , Metais/química , Eletrodos , Íons , EletrólitosRESUMO
Lactoferrin (Lf), a bioactive protein initially found in many biological secretions including milk, is regarded as the nutritional supplement or therapeutic ligand due to its multiple functions. Research on its mode of action reveals that intact Lf or its active peptide (i.e., lactoferricin) shows an important multifunctional performance. Oral delivery is considered as the most convenient administration route for this bioactive protein. Unfortunately, Lf is sensitive to the gastrointestinal (GI) physicochemical stresses and lactoferricin is undetectable in GI digesta. This review introduces the functionality of Lf at the molecular level and its degradation behavior in GI tract is discussed in detail. Subsequently, the absorption and transport of Lf from intestine into the blood circulation, which is pivotal to its health promoting effects in various tissues, and some assisting labeling methods are discussed. Stabilization technologies aiming at preserving the structural integrity and functional properties of orally administrated Lf are summarized and compared. Altogether, this work comprehensively reviews the structure-function relationship of Lf, its oral fate and the development of stabilization technologies for the enhancement of the oral bioavailability of Lf. The existing limitations and scope for future research are also discussed.
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Lactoferrina , Leite , Animais , Fenômenos Químicos , Trato Gastrointestinal/metabolismo , Leite/químicaRESUMO
BACKGROUND AND AIMS: Observational studies have shown an association between mental health and coronary artery disease (CAD) in patients with diabetes. Nevertheless, whether these associations are causal is still unknown. In this two-sample Mendelian randomization (MR) study, we aimed to assess the causality between mental health and CAD in patients with diabetes. METHODS AND RESULTS: Single-nucleotide polymorphisms (SNPs) associated with: depression (807,553 individuals), anxiety (83,556 individuals) and neuroticism (329,821 individuals) were identified from the largest genome-wide association studies (GWAS). Summary-level data for CAD were extracted from the recently published GWAS of 15,666 diabetic patients (3968 CAD cases and 11,696 controls). The inverse-variance weighted (IVW) method was used for the main analysis. Sensitivity analyses included weighted median, maximum likelihood, and the MR-Egger method. Genetic liability to depression was significantly associated with a higher risk of CAD in patients with diabetes (odds ratio [OR], 1.286; 95%CIï¼1.018-1.621ï¼p = 0.035). For anxiety and neuroticism, no causal association with CAD in patients with diabetes was observed. Consistent results were obtained in most sensitivity analyses. CONCLUSIONS: This MR study provides genetic evidence that depression is a potential risk factor for CAD in patients with diabetes. However, anxiety and neuroticism were not causally associated with CAD in patients with diabetes. Mental health treatments should be enhanced to prevent CAD in patients with diabetes.
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Doença da Artéria Coronariana , Diabetes Mellitus , Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/epidemiologia , Doença da Artéria Coronariana/genética , Diabetes Mellitus/genética , Estudo de Associação Genômica Ampla/métodos , Humanos , Análise da Randomização Mendeliana/métodos , Saúde Mental , Polimorfismo de Nucleotídeo ÚnicoRESUMO
BACKGROUND AND AIMS: Observational studies have examined serum urate levels in relation to coronary heart disease (CHD) and myocardial infarction (MI). Whether these associations are causal remains controversial, due to confounding factors and reverse causality. We aim to investigate the causality of these associations using Mendelian randomization method. METHODS AND RESULTS: Instrumental variables were obtained from the largest genome-wide association studies of serum urate (457,690 individuals) to date. Summary statistics were from CARDIoGRAMplusC4D consortium (60,801 CHD cases; 43,676 MI cases), FinnGen (21,012 CHD cases; 12,801 MI cases), UK Biobank (10,157 CHD cases; 7018 MI cases), and Biobank Japan (29,319 CHD cases). Inverse-variance weighted method was applied as the main results. Other statistical methods and reverse MR analysis were conducted in the supplementary analyses. Elevated genetically determined serum urate levels were associated with increased risks of CHD and MI. The association pattern remained for the datasets in FinnGen, the combined results of three independent data sources (CHD: odds ratio (OR), 1.10; 95%CI, 1.06-1.15; p = 4.2 × 10-6; MI: OR, 1.12; 95%CI, 1.07-1.18; p = 2.7 × 10-6), and East Asian population. Interestingly, sex-specific subgroup analyses revealed that these associations kept in men only, but not among women in individuals of European ancestry. No consistent evidence was found for the causal effect of CHD or MI on serum urate levels. CONCLUSION: We provide consistent evidence for the causal effect of genetically predicted serum urate levels on CHD and MI, but not the reverse effect. Urate-lowering therapy may be of cardiovascular benefit in the prevention of CHD and MI, especially for men.
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Doença das Coronárias , Infarto do Miocárdio , Doença das Coronárias/diagnóstico , Doença das Coronárias/epidemiologia , Doença das Coronárias/genética , Feminino , Estudo de Associação Genômica Ampla , Humanos , Masculino , Análise da Randomização Mendeliana , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/genética , Polimorfismo de Nucleotídeo Único , Ácido ÚricoRESUMO
BACKGROUND AND AIMS: Observational studies have indicated that sedentary behavior is associated with myocardial infarction (MI), heart failure (HF), and atrial fibrillation (AF). Nevertheless, whether these associations are causal remain controversial, due to confounding factors (e.g., physical activity) and reverse causality. METHODS AND RESULTS: Instrumental variables were obtained from the largest genome-wide association studies of sedentary behavior (408,815 individuals) to date. We obtained summary statistics of MI from the CARDIoGRAMplusC4D consortium (171,875 individuals), HF from the HERMES Consortium (977,323 individuals), and AF from the Atrial Fibrillation Consortium (588,190 individuals). The inverse-variance weighted method was applied to obtain Mendelian randomization (MR) estimates, and other statistical methods were conducted in the sensitivity analyses. The main analyses were repeated using data from the FinnGen study. Multivariable MR analysis and mediation analysis were performed to evaluate the role of physical activity and other confounders. Genetically determined television watching was associated with MI (odds ratio [OR], 1.38; 95% CI, 1.19-1.59; p = 1.9 × 10-5) and HF (OR, 1.23; 95%CI, 1.09-1.38; p = 7.0 × 10-4) but not AF. The main results kept robust in most sensitivity analyses. The effect of sedentary behavior on MI and HF was partly mediated by body mass index (BMI). No consistent evidence was found for the causal effect of computer use and driving on MI, HF, or AF. CONCLUSIONS: Genetic liability to prolonged television watching is associated with higher risks of MI and HF. Interventions for reducing television watching time, such as public education and awareness campaigns, should be further investigated.
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Fibrilação Atrial , Insuficiência Cardíaca , Infarto do Miocárdio , Fibrilação Atrial/genética , Estudo de Associação Genômica Ampla , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/genética , Humanos , Análise da Randomização Mendeliana , Infarto do Miocárdio/diagnóstico , Infarto do Miocárdio/epidemiologia , Infarto do Miocárdio/genética , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Comportamento SedentárioRESUMO
The Internet has become the main channel of information communication, which contains a large amount of secret information. Although network communication provides a convenient channel for human communication, there is also a risk of information leakage. Traditional image steganography algorithms use manually crafted steganographic algorithms or custom models for steganography, while our approach uses ordinary OCR models for information embedding and extraction. Even if our OCR models for steganography are intercepted, it is difficult to find their relevance to steganography. We propose a novel steganography method for character-level text images based on adversarial attacks. We exploit the complexity and uniqueness of neural network boundaries and use neural networks as a tool for information embedding and extraction. We use an adversarial attack to embed the steganographic information into the character region of the image. To avoid detection by other OCR models, we optimize the generation of the adversarial samples and use a verification model to filter the generated steganographic images, which, in turn, ensures that the embedded information can only be recognized by our local model. The decoupling experiments show that the strategies we adopt to weaken the transferability can reduce the possibility of other OCR models recognizing the embedded information while ensuring the success rate of information embedding. Meanwhile, the perturbations we add to embed the information are acceptable. Finally, we explored the impact of different parameters on the algorithm with the potential of our steganography algorithm through parameter selection experiments. We also verify the effectiveness of our validation model to select the best steganographic images. The experiments show that our algorithm can achieve a 100% information embedding rate and more than 95% steganography success rate under the set condition of 3 samples per group. In addition, our embedded information can be hardly detected by other OCR models.
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Algoritmos , HumanosRESUMO
An oral multi-unit delivery system was developed by incorporating the nanoparticle (NP) into the nanofiber mat and its efficiency for intestinal-specific delivery and controlled release of a peptide (insulin) was investigated. Initially, the influence of deacetylation degree (DD) of chitosan and ionic gelation methods on the properties of NPs was studied. High DD (95%) chitosan was attributed to higher encapsulation efficiency and stability when crosslinked with polyanion tripolyphosphate. Subsequently, the multi-unit system was fabricated using a pH-sensitive polymer (sodium alginate) as the coating layer to further encapsulate the NP. Fiber mat with an average diameter of 481 ± 47 nm could significantly decrease the burst release of insulin in acidic condition and release most amount of insulin (>60%) in the simulated intestinal medium. Furthermore, the encapsulated peptide remained in good integrity. This multi-unit carrier provides the better-designed vehicle for intestinal-specific delivery and controlled release of the peptide.
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Quitosana/química , Insulina/administração & dosagem , Administração Oral , Células CACO-2 , Preparações de Ação Retardada , Composição de Medicamentos , Sistemas de Liberação de Medicamentos , Humanos , Concentração de Íons de Hidrogênio , Insulina/química , Nanopartículas , Polifosfatos/químicaRESUMO
During the production and application of Bacillus thuringiensis (Bt) transgenic crops, large doses of insecticidal Bt toxic proteins are expressed continuously. The multi-interfacial behaviors of Bt proteins entering the environment in multi-media affects their states of existence transformation, transport and fate as well as biological and ecological impacts. Because both soil matrix and organisms will be exposed to Bt proteins to a certain extent, knowledge of the multi-interfacial behaviors and affecting factors of Bt proteins are vital not only for understanding the source-sink distribution mechanisms, predicting their bio-availability, but also for exploring the soil safety and environmental problems caused by the interaction between Bt proteins and soil matrix. This review summarized and analyzed various internal and external factors that affect the adsorption/ desorption and degradation of Bt proteins in the environment, so as to understand the multi-interfacial behaviors of Bt proteins. In addition, the reasons of concentration changes of Bt proteins in soil are discussed. This review will also discuss the existing knowledge of the combined effects of Bt proteins and other pollutants in environment. Finally, discussing the factors that should be considered when assessing the environmental risk of Bt proteins, thus to further improve the understanding of the environmental fate of Bt proteins.
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Bacillus thuringiensis , Adsorção , Bacillus thuringiensis/genética , Proteínas de Bactérias/genética , Endotoxinas , Proteínas Hemolisinas/genética , Plantas Geneticamente Modificadas , SoloRESUMO
Anomaly detection research was conducted traditionally using mathematical and statistical methods. This topic has been widely applied in many fields. Recently reinforcement learning has achieved exceptional successes in many areas such as the AlphaGo chess playing and video gaming etc. However, there were scarce researches applying reinforcement learning to the field of anomaly detection. This paper therefore aimed at proposing an adaptable asynchronous advantage actor-critic model of reinforcement learning to this field. The performances were evaluated and compared among classical machine learning and the generative adversarial model with variants. Basic principles of the related models were introduced firstly. Then problem definitions, modelling processes and testing were detailed. The proposed model differentiated the sequence and image from other anomalies by proposing appropriate neural networks of attention mechanism and convolutional network for the two kinds of anomalies, respectively. Finally, performances with classical models using public benchmark datasets (NSL-KDD, AWID and CICIDS-2017, DoHBrw-2020) were evaluated and compared. Experiments confirmed the effectiveness of the proposed model with the results indicating higher rewards and lower loss rates on the datasets during training and testing. The metrics of precision, recall rate and F1 score were higher than or at least comparable to the state-of-the-art models. We concluded the proposed model could outperform or at least achieve comparable results with the existing anomaly detection models.
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Time series classification and forecasting have long been studied with the traditional statistical methods. Recently, deep learning achieved remarkable successes in areas such as image, text, video, audio processing, etc. However, research studies conducted with deep neural networks in these fields are not abundant. Therefore, in this paper, we aim to propose and evaluate several state-of-the-art neural network models in these fields. We first review the basics of representative models, namely long short-term memory and its variants, the temporal convolutional network and the generative adversarial network. Then, long short-term memory with autoencoder and attention-based models, the temporal convolutional network and the generative adversarial model are proposed and applied to time series classification and forecasting. Gaussian sliding window weights are proposed to speed the training process up. Finally, the performances of the proposed methods are assessed using five optimizers and loss functions with the public benchmark datasets, and comparisons between the proposed temporal convolutional network and several classical models are conducted. Experiments show the proposed models' effectiveness and confirm that the temporal convolutional network is superior to long short-term memory models in sequence modeling. We conclude that the proposed temporal convolutional network reduces time consumption to around 80% compared to others while retaining the same accuracy. The unstable training process for generative adversarial network is circumvented by tuning hyperparameters and carefully choosing the appropriate optimizer of "Adam". The proposed generative adversarial network also achieves comparable forecasting accuracy with traditional methods.
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The insider threats have always been one of the most severe challenges to cybersecurity. It can lead to the destruction of the organisation's internal network system and information leakage, which seriously threaten the confidentiality, integrity and availability of data. To make matters worse, since the attacker has authorized access to the internal network, they can launch the attack from the inside and erase their attack trace, which makes it challenging to track and forensics. A blockchain traceability system for insider threats is proposed in this paper to mitigate the issue. First, this paper constructs an insider threat model of the internal network from a different perspective: insider attack forensics and prevent insider attacker from escaping. Then, we analyze why it is difficult to track attackers and obtain evidence when an insider threat has occurred. After that, the blockchain traceability system is designed in terms of data structure, transaction structure, block structure, consensus algorithm, data storage algorithm, and query algorithm, while using differential privacy to protect user privacy. We deployed this blockchain traceability system and conducted experiments, and the results show that it can achieve the goal of mitigating insider threats.
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BACKGROUND: Increasing food safety awareness of consumers promotes the development of rapid and sensitive detection techniques for pesticide residues. In this study, a new type of rapid detection card for organophosphorus and carbamate pesticide residues was developed by electrospinning. The card involved enzyme fiber mat (EFM) and substrate fiber mat (SFM) which were prepared by mixing poly(vinyl alcohol) with acetylcholinesterase (AChE) and indolyl acetate (IA), respectively. RESULTS: The mean diameter of fibers was 240 ± 53 nm for EFM and 387 ± 84 nm for SFM. Results of Fourier transform infrared and X-ray photoelectron spectroscopies confirmed that AChE and IA were successfully encapsulated into the fibers. The minimum concentrations of AChE and IA for effective detection were 1 and 3 mg mL-1 , respectively, and the optimal detection time was 15 min. The limits of detection for this card were 0.5 mg L-1 for omethoate, 1.5 mg L-1 for malathion, 0.1 mg L-1 for carbaryl and 0.02 mg L-1 for carbofuran. The detection card exhibited good storage stability and its activity could be maintained when stored at room temperature for at least 4 months. Additionally, the EFM can be reused three times. CONCLUSIONS: The detection card obtained here was superior to a commercial card in detecting pesticide residues in real food samples. Hence, this electrospun detection card has potential for simple, rapid and sensitive analysis of pesticide residues. © 2020 Society of Chemical Industry.