| 1. |
- Zhang, Cheng, et al.
(författare)
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A Blockchain-based Model Migration Approach for Secure and Sustainable Federated Learning in IoT Systems
- 2023
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Ingår i: IEEE Internet of Things Journal. - : IEEE. - 2327-4662. ; 10:8, s. 6574-6585
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Tidskriftsartikel (refereegranskat)abstract
- Model migration can accelerate model convergence during federated learning on the Internet of Things (IoT) devices and reduce training costs by transferring feature extractors from fast to slow devices, which, in turn, enables sustainable computing. However, malicious or lazy devices may migrate the fake models or resist sharing models for their benefit, reducing the desired efficiency and reliability of a federated learning system. To this end, this work presents a blockchain-based model migration approach for resource-constrained IoT systems. The proposed approach aims to achieve secure model migration and speed up model training while minimizing computation cost. We first develop an incentive mechanism considering the economic benefits of fast devices, which breaks the Nash equilibrium established by lazy devices and encourages capable devices to train and share models. Second, we design a clustering-based algorithm for identifying malicious devices and preventing them from defrauding incentives. Third, we use blockchain to ensure trustworthiness in model migration and incentive processes. Blockchain records the interaction between the central server and IoT devices and runs the incentive algorithm without exposing the devices’ private data. Theoretical analysis and experimental results show that the proposed approach can accelerate federated learning rates, reduce model training computation costs to increase sustainability, and resist malicious attacks.
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| 2. |
- Jing, Shuping, et al.
(författare)
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Household Transmission of Human Adenovirus Type 55 in Case of Fatal Acute Respiratory Disease
- 2019
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Ingår i: Emerging Infectious Diseases. - : Centers for Disease Control and Prevention (CDC). - 1080-6040 .- 1080-6059. ; 25:9, s. 1756-1758
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Tidskriftsartikel (refereegranskat)abstract
- We identified a case of fatal acute respiratory disease from household transmission of human adenovirus type 55 (HAdV-55) in Anhui Province, China. Computed tomography showed severe pneumonia. Comparative genomic analysis of HAdV-55 indicated the virus possibly originated in Shanxi Province, China. More attention should be paid to highly contagious HAdV-55.
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| 3. |
- Liu, Yi, et al.
(författare)
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Porous, robust, thermally stable, and flame retardant nanocellulose/polyimide separators for safe lithium-ion batteries
- 2023
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 11:43, s. 23360-23369
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Tidskriftsartikel (refereegranskat)abstract
- The safety of lithium-ion batteries (LIBs) is paramount for all users. One effective way to improve safety is incorporating heat-resistant polyimide (PI) separators, which can increase the thermal stability of batteries and minimize the risk of thermal runaway. However, preparing PI separators with both an ideal pore structure and adequate mechanical properties remains as a challenge. Here, we introduced decabromodiphenyl ethane (DBDPE) and cellulose nanofibers (CNFs) into PI and produced a hybrid separator with an outstanding pore structure and excellent mechanical properties. Aided with DBDPE, the separators attain a well-defined and uniform pore size (20 nm), while demonstrating high porosities (78%) through phase inversion processes. Owing to the addition of CNFs, the mechanical properties of the separators were significantly improved, with a tensile strength of 25.4 MPa and an elastic modulus of 550.1 MPa. Moreover, the separators demonstrate high ion conductivity (0.45 mS cm-1), excellent thermal-dimensional stability (up to 200 degrees C), remarkable flame retardancy, and outstanding electrolyte wettability. At room temperature, the batteries with the separators demonstrate comparable performance with those of polypropylene (PP) separators. However, when subjected to thermal shock treatments, the batteries with the separators outperform those with PP, showcasing their superior performance. The work introduces a novel strategy for designing high-performance separators, thereby paving the way for advancements in the fabrication of LIBs with enhanced safety features. A porous, robust, and thermally stable hybrid separator was developed to solve the dilemma between desired pore structures and mechanical properties in polyimide separators by introducing decabromodiphenyl ethane and cellulose nanofibers.
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| 4. |
- Bai, Ru, et al.
(författare)
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Clinical characteristics and phylogenetic analysis of human enteric adenovirus type 41 (HAdV-F41) from children with gastroenteritis during SARS-CoV-2 pandemic
- 2024
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Ingår i: Infection, Genetics and Evolution. - : Elsevier. - 1567-1348 .- 1567-7257. ; 123
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Tidskriftsartikel (refereegranskat)abstract
- Human adenovirus type 41 (HAdV-F41) usually causes pediatrics gastroenteritis. However, it was reported to be associated with the outbreaks of severe acute hepatitis of unknown aetiology (SAHUA) in pediatrics during COVID-19 pandemic. In this study, we investigated the prevalence of enteric HAdV-F41 in 37,920 paediatric gastroenteritis cases from 2017 to 2022 in Guangzhou, China. All children presented were tested negative for SARS-CoV-2 during the “zero-COVID” period. The main clinical symptom of the children was diarrhea (96.5%). No fatalities nor liver abnormal symptoms was found. In 2021, one year since the pandemic of COVID-19, the prevalence of HAdV-F41 abruptly increased from 3.71% to 8.64% (P < 0.001). All of HAdV-F41 circulating worldwide were classified into eight different subtypes (G1-G8) based on the phylogenetic clustering permutation of the four capsid genes of HAdV-F41. G3 was the predominant subtype (56.2%; 77/137). CRV5 isolates from SAHUA cases belong to this subtype, in which N312D and H335D mutations in the short fiber knob were identified in both Guangzhou and CRV5 isolates, presumably changing the virus tropism by directly interacting with the heparin sulfate (HS) receptor. Additionally, a novel recombinant G6 subtype, which is unique and only circulating in China was first identified in this study. This is the first study highlighting the prevalence of HAdV-F41 in paediatric cases of gastroenteritis during COVID-19 pandemic in China. The clinical and viral evolution finding of HAdV-F41 provide insight into the clinical characteristics of children with HAdV-F41 infections as well as the uncertain role of HAdV-F41 in the cause of SAHUA.
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| 5. |
- Zhang, Songhong, et al.
(författare)
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Hydrophobic cryogels prepared via cryo-polymerization as oil carriers for biosynthesis of sophorolipids
- 2020
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Ingår i: Biochemical Engineering Journal. - : Elsevier BV. - 1369-703X. ; 161
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Tidskriftsartikel (refereegranskat)abstract
- Microbial synthesis of high-value biochemicals like biosurfactants using renewable substrates has attracted an intensive interest in the past decade. In this work, the bioproduction of sophorolipids was achieved by fermentation of different vegetable oils with the strain of Candida bombicola A0803 using novel hydrophobic poly(butyl methacrylate)(pBMA) cryogels as the oil substrate delivery carriers. The hydrophobic cryogels were prepared successfully via the cryo-polymerization of the reactive emulsion containing hydrophobic monomers under freezing conditions, and the characterization of cryogels was investigated experimentally. The results showed that the polymerization yields of 70 %–89 % were achieved and the cryogels had supermacropores with the maximum porosities of 92 %–96 % and good elasticity in organic solvents but rigid in water, which could provide preferable release properties for vegetable oils. Theie Young's elasticity modulus varied from 0.096 to 0.951 kPa in ethanol and acetone and the related aqueous solutions. With the pBMA cryogels as the delivery carriers of oil substrates, the maximum concentrations of sophorolipids produced for rapeseed, perilla seed and linseed oils were improved 14.5 %, 54.5 % and 53.7 %, while the maximum productivities were improved 14.5 %, 72.1 % and 42.7 % compared with those under the same fermentation condition of free carriers after 204 h–252 h of cultivation, indicating that the hydrophobic cryogels could be an interesting material for the potential applications in biosynthesis areas.
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