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In edge-fog computing networks, it is very crucial to ensure that group keys are secure and reliable. In recent years, there has been much interest in group key updating schemes based on Chinese remainder theorem (CRT). It is mostly necessary to utilize the extended Euclidean algorithm to compute the inverse element in conventional schemes. But it does not always exist an inverse element. It leads to the computation being complicated and infeasible. Thus, we propose a scheme for updating group keys and batch verification based on Euler function and Chinese remainder theorem (EF-CRT). Group keys can be constructed directly using Euler function without requiring inverse elements. In addition, we design a batch verification scheme using the updated group key. The proposed EF-CRT scheme accomplishes dynamic group key updates, message integrity authentication, forward and backward security, and conditional privacy protection. Simultaneously, we prove that the security of EF-CRT is existentially unforgeable under the chosen message attack. In experiments with the java pairing-based cryptography library, the proposed scheme shows efficiency both in computational and communication overhead.

Federated learning has emerged as a promising paradigm by collaboratively training a global model through sharing local gradients without exposing raw data. However, the shared gradients pose a threat to privacy leakage of local data. The central server may forge the aggregated results. Besides, it is common that resource-constrained devices drop out in federated learning. To solve these problems, the existing solutions consider either only efficiency, or privacy preservation. It is still a challenge to design a verifiable and lightweight secure aggregation with drop-out resilience for large-scale federated learning. In this article, we propose VOSA, an efficient verifiable and oblivious secure aggregation protocol for privacy-preserving federated learning. We exploit aggregator oblivious encryption to efficiently mask users’ local gradients. The central server performs aggregation on the obscured gradients without revealing the privacy of local data. Meanwhile, each user can efficiently verify the correctness of the aggregated results. Moreover, VOSA adopts a dynamic group management mechanism to tolerate users’ dropping out with no impact on their participation in future learning process. Security analysis shows that the VOSA can guarantee the security requirements of privacy-preserving federated learning. The extensive experimental evaluations conducted on real-world datasets demonstrate the practical performance of the proposed VOSA with high efficiency.

ABSTRACTCholangiocarcinoma (CCA) is a fatal tumor associated with chronic inflammation. Circular RNAs (circRNAs) have been evidenced to be involved in tumorigenesis and tumor progression. This study aimed to explore the effects and potential molecular mechanism of circSETD3 in CCA progression. Levels of CircSETD3 and microRNA (miR)-421 in CCA tissue and cell lines were measured using quantitative real-time polymerase-chain reaction (qRT-PCR). A direct target of miR-421 was predicted using TargetScan and further confirmed by a dual-luciferase reporter assay. Cell proliferation and apoptosis were measured using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and flow cytometry, respectively. The activity of caspase-3 was also examined using caspase-3 activity detection kits. Moreover, the levels of B-cell lymphoma-2 modifying factor (BMF), B-cell lymphoma 2 (BCL2), and Bcl-2-associated X protein (BAX) in TFK1 cells were assessed using qRT-PCR and western blot analysis. We found that circSETD3 was downregulated, while miR-421 was upregulated in CCA tissues and cell lines. CircSETD3 negatively regulated miR-421 levels in TFK1 cells. Functional assays revealed that circSETD3-plasmid inhibited cell proliferation, induced apoptosis, promoted caspase-3 activity, enhanced Bax and cleaved-Caspase 3 expression, and reduced Bcl-2 levels, and these effects were reversed by miR-421 mimic. Meanwhile, similar results were observed in miR-421 inhibitor-transfected TFK1 cells, and these results were abolished by BMF-siRNA. BMF, a direct target of miR-421, was downregulated in CCA tissues and cell lines. These findings demonstrate that circSETD3 inhibits proliferation and induces apoptosis in CCA cells by regulating the miR-421/BMF axis, indicating its potential as a promising candidate for CCA therapy.

Domain-specific programming frameworks are usually effective to simplify the development of large-scale applications on supercomputers. This paper introduces a programming framework named JAUMIN for large-scale numerical applications on unstructured meshes. Based on this framework, serial codes are only required to be written for large-scale parallel application suitable for modern supercomputers with tens of thousands of CPU cores.

Our previous study showed that miR-29 attenuates muscle wasting in chronic kidney disease. Other studies found that miR-29 has anti-fibrosis activity. We hypothesized that intramuscular injection of exosome-encapsulated miR-29 would counteract unilateral ureteral obstruction (UUO)-induced muscle wasting and renal fibrosis. We used an engineered exosome vector, which contains an exosomal membrane protein gene Lamp2b that was fused with the targeting peptide RVG (rabies viral glycoprotein peptide). RVG directs exosomes to organs that express the acetylcholine receptor, such as kidney. The intervention of Exo/miR29 increased muscle cross-sectional area and decreased UUO-induced upregulation of TRIM63/MuRF1 and FBXO32/atrogin-1. Interestingly, renal fibrosis was partially depressed in the UUO mice with intramuscular injection of Exo/miR29. This was confirmed by decreased TGF-β, alpha-smooth muscle actin, fibronectin, and collagen 1A1 in the kidney of UUO mice. When we used fluorescently labeled Exo/miR29 to trace the Exo/miR route in vivoand found that fluorescence was visible in un-injected muscle and in kidneys. We found that miR-29 directly inhibits YY1 and TGF-β3, which provided a possible mechanism for inhibition of muscle atrophy and renal fibrosis by Exo/miR29. We conclude that Exo/miR29 ameliorates skeletal muscle atrophy and attenuates kidney fibrosis by downregulating YY1 and TGF-β pathway proteins.

Mitochondrial dysfunction is increasingly recognized as an important factor in glomerular diseases. Previous study has shown that mitochondrial fission contributed to mitochondrial dysfunction. However, the mechanism of mitochondrial fission on mitochondrial dysfunction in aldosterone-induced podocyte injury remains ambiguous. This study aimed to investigate the pathogenic effect of mitochondrial fission both in vivo and in vitro. In an animal model of aldosterone-induced nephropathy, inhibition of the mitochondrial fission protein dynamin-related protein 1 (Drp1) suppressed aldosterone-induced podocyte injury. In cultured podocytes, aldosterone dose dependently induced Drp1 expression. Knockdown of Drp1 inhibited aldosterone-induced mitochondrial fission, mitochondrial dysfunction, and podocyte apoptosis. Furthermore, aldosterone dose dependently induced p53 expression. Knockdown of p53 inhibited aldosterone-induced Drp1 expression, mitochondrial dysfunction, and podocyte apoptosis. These findings implicated that aldosterone induced mitochondrial dysfunction and podocyte injury mediated by p53/Drp1-dependent mitochondrial fission, which may provide opportunities for therapeutic intervention for podocyte injury.

Linear flexible supercapacitors are of considerable interest for future wearable electronics and photodetectors. Inorganic metallic oxide‐based electrochemical pseudocapacitors have a high energy density whereas supercapacitors based on carbon‐nanotube (CNT) yarns show high flexibility and high power densities. Besides high power density and energy density, fabrication of linear supercapacitors with excellent flexibility is still a challenge. Here, we report a linear supercapacitor architecture obtained by integrating CNT yarn and a Cu filament with NiCo2O4nanowires. NiCo2O4nanowires grow in situ on the surface of CNT yarn intertwined with the Cu filament. Due to the high electrochemical performance of both NiCo2O4nanowires and CNT yarn and the high charge‐transport efficiency of the Cu filament as current collector, the supercapacitor demonstrates a specific areal capacitance as high as 277.3 mF cm2and an energy density of 35.76 μWh cm−2coupled with a power density 0.154 mW cm−2. The linear supercapacitor is very flexible and can be woven into a fabric without losing its capacity to store energy. Its capacitance remains at 89 % after 5000 charge/discharge cycles. The linear supercapacitor may be used as an ultraviolet photodetector with good stability in response to the UV light signal and also to power light‐emitting diodes (LEDs). Charging the yarn: A two‐ply carbon nanotube yarn is used to fabricate a supercapacitor for wearable electronic textiles and self‐power systems starting from a Cu/carbon nanotube (CNT)@NiCo2O4nanowire composite electrode. The yarn supercapacitor exhibits a specific capacitance as high as 277.3 mF cm−2and a high areal energy density of 35.76 μWh cm−2. A number of such linear supercapacitors can be connected to power a photodetector and a light‐emitting diode (LED).

Permission delegation has become a new way for data sharing by delegating the authorized permission to other users. A flexible authorization model with strict access control policies is promising for electronic health record (EHR) sharing with security. In this paper, a blockchain-based multi-hop permission delegation scheme with controllable delegation depth for EHR sharing has been presented. We use the interplanetary file system (IPFS) for storing the original EHRs. Smart contracts and proxy re-encryption technology are implemented for permission delegation. In order to ensure data security, we use attribute-based encryption to provide fine-grained access control. Additionally, blockchain is used to achieve traceability and immutability. We deploy smart contracts so that the delegation depth can be set by delegators. Security analysis of the proposed protocol shows that our solution meets the designed goals. Finally, we evaluate the proposed algorithm and implement the scheme on the Ethereum test chain. Our scheme outperforms the competition in terms of performance, according to the results of our experiments.

Threadlike linear supercapacitors have demonstrated high potential for constructing fabrics to power electronic textiles (eTextiles). To improve the cyclic electrochemical performance and to produce power fabrics large enough for practical applications, a current collector has been introduced into the linear supercapcitors to transport charges produced by active materials along the length of the supercapacitor with high efficiency. Here, we first screened six candidate metal filaments (Pt, Au, Ag, AuAg, PtCu, and Cu) as current collectors for carbon nanotube (CNT) yarn-based linear supercapacitors. Although all of the metal filaments significantly improved the electrochemical performance of the linear supercapacitor, two supercapacitors constructed from Cu and PtCu filaments, respectively, demonstrate far better electrochemical performance than the other four supercapacitors. Further investigation shows that the surfaces of the two Cu-containing filaments are oxidized by the surrounding polymer electrolyte in the electrode. While the unoxidized core of the Cu-containing filaments remains highly conductive and functions as a current collector, the resulting CuO on the surface is an electrochemically active material. The linear supercapacitor architecture incorporating dual active materials CNT + Cu extends the potential window from 1.0 to 1.4 V, leading to significant improvement to the energy density and power density.

Objective Implantation of the conceptus in a twin cesarean scar pregnancy (CSP) is considered the rarest type of ectopic pregnancy. Preserving the fetus in uteroand effectively dealing with CSP can be challenging. This study aimed to determine the clinical value of ultrasonography by monitoring imaging changes in twin CSP following selective feticide.Methods Ultrasonographic and clinical data were collected from four patients with twin CSP who were treated between December 2017 and December 2018 at our hospital.Results All patients had a history of cesarean section, followed by a heterotopic CSP, with one embryo implanted into the uterine cavity and the other located in the anterior isthmus. All of the patients were pregnant with twins with double chorionic and amniotic sacs, and all gave birth in our hospital. The patients underwent feticide at 8 to 9 weeks of gestation, after which we focused on monitoring the implantation. Delivery was performed by cesarean section according to scores of an ultrasonic scoring system and clinical manifestations. The patients’ uterus was preserved and they recovered.Conclusions This study shows that ultrasound is useful for determining the timing of clinical termination of CSP by selective feticide.

Self-assemblies fabricated from dendrimers and amphiphilic polymers have demonstrated remarkable performances and a wide range of applications. Direct self-assembly of hyperbranched polymers into highly ordered macrostructures with heat-resistance remains a big challenge due to the weak amphiphilicity of the polymers. Here, we report the self-assembly of amphiphilic amido-ended hyperbranched polyester (HTDA-2) into millimeter-size dendritic films using combined hydrogen bond interaction and solvent induction. The self-assembly process and mechanism have been studied. Hydrogen bond interaction between amido-ended groups assists the aggregation of inner and outer chains of the HTDA-2, resulting in phase separation and micelle formation. Some micelles attach to and grow on the glass substrate like seedlings. Other micelles move to the seedlings and connect with their branches via solvent induction and hydrogen bond interaction, leading to the fabrication of highly ordered crystalline dendritic films that show high heat-resistance. HTDA-2 can further self-assemble into sheet crystals on the dendritic films.

Novel organic/inorganic hybrid polyphosphazenes were prepared by free radical UV copolymerization of linear polyphosphazenes and vinyl monomers. In this work, linear polyphosphazenes grafted by allyl amino and n-butylamino groups have been synthesized via nucleophilic substitution reaction at an anhydrous and anaerobic atmosphere. By regulating the molar ratio of allyl amino and n-butylamino groups, five different linear polyphosphazenes were prepared. The hybrid polyphosphazenes have been crosslinked using the linear polyphosphazenes and vinyl monomers including styrene, methyl methacrylate, and lauryl methacrylate as intermediates via free radical UV copolymerization. By changing the quantity of vinyl monomers participating in the crosslinking reaction, series of hybrid polyphosphazene membranes were obtained. The linear polyphosphazenes have been characterized by Nuclear magnetic resonance, Fourier transform infrared (FTIR), Thermogravimetric analysis (TGA), Differential scanning calorimeter, Dynamic mechanical analyzer and Drop Shape Analysis (DSA). The hybrid polyphosphazenes have also been studied via FTIR, TGA and DSA. The test results proved that the linear polymers were successfully synthesized. Moreover, the water contact angles showed that the hybrid crosslinked polyphosphazenes had a better hydrophobicity and thermal stability than the linear polyphosphazenes and the hydrophobicity of hybrid membranes have a regular changing tendency with the quantities of UV-monomers and ratio of allylamino. The initial decomposition temperatures of the hybrid polymers also had a regular change due to the difference and quantities of vinyl monomers.

Well-dispersed epoxy resin/halloysite nanotubes composites were prepared by functionalization of the HNTs surfaces using polyamidoamine generation-3 (HNTs-G3.0). A series of modified halloysite nanotubes with different generations of dendritic polyamidoamine (PAMAM) were prepared via a divergent synthetic process by repeating the Michael addition of methyl acrylate to superficial amino groups and the amidation of the resulting esters with ethylenediamine. The products were then characterized by means of FTIR, XPS, XRD and TGA. The results showed that PAMAM polymers are successfully grafted on the surface of HNTs and the grafting percentage of HNTs grafted with polyamidoamine generation-3 (HNTs-G3.0) is 27.21 %. The grafted PAMAM has no effect on the crystalline structure of HNTs. The morphology, interfacial interaction and mechanical properties of epoxy composites were investigated and correlated with the surface functionalization of HNTs. The observations of scanning electronic microscopy and transmission electron microscopy images showed that HNTs-G3.0 exhibited better dispersion than the p-HNTs. The interfacial interaction of the epoxy composites was studied by FTIR and DMA. It was found that dendritic polyamidoamine graft can effectively improve the interfacial interaction of the epoxy composites. With the improvement in particle dispersion and interfacial interaction through polyamidoamine generation-3 grafting, an increase of impact strength and fracture toughness was achieved, accompanied by enhancements of flexural strength and modulus. In particular, the impact strength and fracture toughness (KIC) of composites with polyamidoamine generation-3 grafted HNTs were about 160 and 20 % higher than the values of functionalization halloysite nanotube system.

Tetrakis(1-adamantanecarboxymethyl)methane was prepared by indirect esterification. DSC traces of tetrakis(1-adamantanecarboxymethyl)methane showed two endothermic peaks. Entropy ratio of these two peaks is: ?Strs/?Sfus= 1.58 > 1. XRD confirmed the solid–solid transition and analysis of XRD by DICVOL demonstrated tetrakis(1-adamantanecarboxymethyl)methane is a new compound with a highly disordered crystalline phase. Analysis of entropy changes at transitions showed why fusion entropy (?Sfus= 70.07 J mol-1K-1) of tetrakis(1-adamantanecarboxymethyl)methane is much larger than Timmermans’ criterion.

Abstract: Fast multipole method (FMM) may reduce the complexity of N-body problems from O(N 2) to O(N logN) or O(N). It was applied in problems ranging from electromagnetic scattering to dislocation dynamics. FMM can be divided into two parts: commonness and individuality. A parallel solver of FMM commonly used in various applications has been designed and implemented in JASMIN infrastructure. The solver encapsulates the commonness. Furthermore, it supplies users with abstract interfaces required to implement the individuality with serial mode. The commonness contains distributed storage of multi-levels, intra-level and inter-level data communication, and arrangement of computation, etc. The individuality contains various expansion and translation operators. We give here two applications that have used the solver. Scalability was demonstrated with a parallel efficiency above 80% on 1024 processors.

A variety of silicon based multilevel branched submicrometer/ nanostructures, such as branched nanowheat-heads, big branched nanowheat-heads, and branched nanowires, have been rationally synthesized via a simple one-step, inexpensive, and catalyst-free fabrication technique. High-resolution transmission electron microscopy studies suggested that the main stem of wheat head and the nanotips of silicon branched nanowheat-heads are single crystals with the preferential growth direction along the [1̅12] and [11̅2] and orientation, respectively. Compared with big branched nanowheat-heads and branched nanowires, the room-temperature Raman frequency of branched nanowheat-heads is blue-shifted and its full width at half-maximum broadens. A moderately strong photoluminescence emission at 550 nm was suggested to be induced by defects, such as stacking faults or the SiOxsurface in the branched nanowheat-heads, suggesting potential applications in light-emitting nanodevices. These studies shed light on new opportunities for fabricating different 3-dimensional nanostructures based on their property investigation.

A new approach for the synthesis of polyaniline (PANI) nanostructures under UV light illumination has been developed, which is the first report of a templateless chemical process for preparing pure PANI nanowires. The acceleration effect of photo‐assistance on the polymerization can promote the homogeneous nucleation and elongation of the nanofibers and nanowires, leading to easy preparation of tunable diameters of the nanowires and nanofibers of PANI.

A series of copolyimides containing different ratios of fluorine and phosphine oxide were synthesized. The copolymers were characterized with Fourier transform infrared, differential scanning calorimetry, and thermogravimetric analysis measurements. The copolymers were thermally stable up to 700 K and exhibited glass‐transition temperatures in the range of 495–562 K. The glass‐transition temperatures of the copolymers decreased with an increase in the phosphine oxide content. The thermal decomposition behavior of the copolymers was investigated. The copolymers with higher phosphine oxide contents displayed lower onset decomposition temperatures and char yields. A new method involving the multiple‐rate isotemperature was used to define the most possible mechanism [G(α)] for the reactions. The overall kinetic model function of the thermal decomposition of these copolymers obeyed the Avrami–Erofeev model equation, G(α) = [−ln(1 − α)]1/m, where α is the conversion degree. The apparent kinetic parameters of the degradation processes were also obtained. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2139–2143, 2005

A soluble aromatic polyimide was chloromethylated via a reaction with chloromethyl methyl ether in the presence of tin(IV) chloride to produce a new starting material for the modification of aromatic polyimides. The chemical structure of the resulting polymer was confirmed by ¹H NMR and Fourier transform infrared spectroscopy. The maximum number of chloromethyl groups per repeat unit was 1.81. The chloromethylated polyimide was stable up to 250 °C and soluble in both chloroform and tetrahydrofuran. So that its utilization for further modification could be demonstrated, cinnamic acid was reacted with the formed polyimide, and it produced a new photosensitive polyimide with a cinnamoyl side chain. The photosensitivity of the resulting polyimide was investigated with ultraviolet spectroscopic methods. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 22–29, 2003

Terpenoids are a large class of lipid molecules with important biological functions and diverse industrial and medicinal applications. Metabolic engineering for terpene production has been hindered by the low-flux distribution to its biosynthesis pathway.

Ethylbenzonitriles (V) and (VI) are prepared by ammoxidation of ethylbenzyl chlorides in the presence of a mixed vanadium‐chromium oxide.

Three title salts are prepared and tested in the presence of Ru and Ir catalyst.

A series of ligands of type (I) and (II) is synthesized.