An unsymmetrical di-copper complex, (Cu2(TPMAN)(μ-OH)(H2O)3+, was prepared and used for electrocatalytic water oxidation in neutral conditions. This complex is a stable and efficient homogeneous ...catalyst during the electrocatalytic oxygen evolution process (k cat = 0.78 s–1) with 780 mV onset overpotential in 0.1 M phosphate buffer (pH 7.0). The water oxidation mechanism of the unsymmetrical catalyst Cu2(TPMAN)(μ-OH)3+ exhibits different behaviors than that of Cu2(BPMAN)(μ-OH)3+, such as two redox steps with different pH dependences, a significant kinetic isotope effect, and buffer concentration dependence. All these changes were ascribed to the open site on the Cu center that is formed by removal of the hemilabile pyridyl site, which acts as an intramolecular proton acceptor to assist the O–O bond formation step.
Proof of work (PoW), the most popular consensus mechanism for blockchain, requires ridiculously large amounts of energy but without any useful outcome beyond determining accounting rights among ...miners. To tackle the drawback of PoW, we propose a novel energy-recycling consensus algorithm, namely proof of federated learning (PoFL), where the energy originally wasted to solve difficult but meaningless puzzles in PoW is reinvested to federated learning. Federated learning and pooled-mining, a trend of PoW, have a natural fit in terms of organization structure. However, the separation between the data usufruct and ownership in blockchain lead to data privacy leakage in model training and verification, deviating from the original intention of federal learning. To address the challenge, a reverse game-based data trading mechanism and a privacy-preserving model verification mechanism are proposed. The former can guard against training data leakage while the latter verifies the accuracy of a trained model with privacy preservation of the task requester's test data as well as the pool's submitted model. To the best of our knowledge, our article is the first work to employ federal learning as the proof of work for blockchain. Extensive simulations based on synthetic and real-world data demonstrate the effectiveness and efficiency of our proposed mechanisms.
Since December 2019, the 2019 coronavirus disease (COVID-19) has expanded to cause a worldwide outbreak that more than 600,000 people infected and tens of thousands died. To date, the clinical ...characteristics of COVID-19 patients in the non-Wuhan areas of Hubei Province in China have not been described.
We retrospectively analyzed the clinical characteristics and treatment progress of 91 patients diagnosed with COVID-19 in Jingzhou Central Hospital.
Of the 91 patients diagnosed with COVID-19, 30 cases (33.0%) were severe and two patients (2.2%) died. The severe disease group tended to be older (50.5 vs. 42.0 years; p = 0.049) and have more chronic disease (40% vs. 14.8%; p = 0.009) relative to mild disease group. Only 73.6% of the patients were quantitative polymerase chain reaction (qPCR)-positive on their first tests, while typical chest computed tomography images were obtained for each patient. The most common complaints were cough (n = 75; 82.4%), fever (n = 59; 64.8%), fatigue (n = 35; 38.5%), and diarrhea (n = 14; 15.4%). Non-respiratory injury was identified by elevated levels of aspartate aminotransferase (n = 18; 19.8%), creatinine (n = 5; 5.5%), and creatine kinase (n = 14; 15.4%) in laboratory tests. Twenty-eight cases (30.8%) suffered non-respiratory injury, including 50% of the critically ill patients and 21.3% of the mild patients.
Overall, the mortality rate of patients in Jingzhou was lower than that of Wuhan. Importantly, we found liver, kidney, digestive tract, and heart injuries in COVID-19 cases besides respiratory problems. Combining chest computed tomography images with the qPCR analysis of throat swab samples can improve the accuracy of COVID-19 diagnosis.
Fault diagnosis has received considerable attention because its implementation can effectively prevent costly and even catastrophic downtime. However, quickly identifying faults and accurately ...obtaining diagnosis results from a feature set of rotating machinery are still a problem. To this end, this paper proposes an effective method based on a weighted extreme learning machine (WELM) with wavelet packet decomposition (WPD) and kernel principal component analysis (KPCA). The feature set affecting classification accuracy can be obtained using WPD and KPCA. By taking feature reliability into consideration, a new type of improvement to the extreme learning machine (ELM), i.e., WELM, is proposed by associating the hidden layer and input layer with a weight matrix. The WELM model can help in guaranteeing a quick and an accurate identification of fault status. To verify the superiority of the fault identification speed and accuracy of the proposed method, results from other methods, namely, using the sensitive features based on WPD and KPCA with ELM, a back-propagation neural network, and a support vector machine, were compared. The experimental results indicate that the proposed method can effectively improve the accuracy and quickly diagnose the fault. The average accuracy of fault classification could reach 95.45%, and the computation time of WELM was only 0.0156 s.
Radiofrequency ablation (RFA) is considered a curative treatment option for hepatocellular carcinoma (HCC). Growing data have demonstrated that cryoablation represents a safe and effective ...alternative therapy for HCC, but no randomized controlled trial (RCT) has been reported to compare cryoablation with RFA in HCC treatment. The present study was a multicenter RCT aimed to compare the outcomes of percutaneous cryoablation with RFA for the treatment of HCC. In all, 360 patients with Child‐Pugh class A or B cirrhosis and one or two HCC lesions ≤ 4 cm, treatment‐naïve, without metastasis were randomly assigned to cryoablation (n = 180) or RFA (n = 180). The primary endpoints were local tumor progression at 3 years after treatment and safety. Local tumor progression rates at 1, 2, and 3 years were 3%, 7%, and 7% for cryoablation and 9%, 11%, and 11% for RFA, respectively (P = 0.043). For lesions >3 cm in diameter, the local tumor progression rate was significantly lower in the cryoablation group versus the RFA group (7.7% versus 18.2%, P = 0.041). The 1‐, 3‐, and 5‐year overall survival rates were 97%, 67%, and 40% for cryoablation and 97%, 66%, and 38% for RFA, respectively (P = 0.747). The 1‐, 3‐, and 5‐year tumor‐free survival rates were 89%, 54%, and 35% in the cryoablation group and 84%, 50%, and 34% in the RFA group, respectively (P = 0.628). Multivariate analyses demonstrated that Child‐Pugh class B and distant intrahepatic recurrence were significant negative predictors for overall survival. Major complications occurred in seven patients (3.9%) following cryoablation and in six patients (3.3%) following RFA (P = 0.776). Conclusion: Cryoablation resulted in a significantly lower local tumor progression than RFA, although both cryoablation and RFA were equally safe and effective, with similar 5‐year survival rates. (Hepatology 2015;61:1579–1590)
In pigs, three circovirus species within the genus Circovirus have been identified so far, including the non‐pathogenic Porcine circovirus 1 (PCV1), the pathogenic Porcine circovirus 2 (PCV2) and the ...recently identified Porcine circovirus 3 (PCV3). In April 2019, a new circovirus with a distinct relationship to other circoviruses was identified in several pigs with severe clinical disease in Hunan province, China. The size of the viral genome, tentatively designated as porcine circovirus type 4 (PCV4), is 1,770 nucleotides (nt). PCV4 shows the highest genomic identity to mink circovirus (66.9%) and has identities of 43.2%–51.5% to the other PCV genomes. Two major genes, a replicase (Rep) gene spanning 891 nt and a capsid (Cap) gene spanning 687 nt, were predicted. Furthermore, a TaqMan® real‐time polymerase chain reaction (PCR) targeting the replicase gene was developed to investigate the prevalence of PCV4 in 187 clinical samples from Hunan province, China. The results revealed an overall PCV4 prevalence of 12.8%, with the highest positive rates in nasal swabs (28.5%, 6/21) followed by serum samples (13.4%, 11/82). The clinical significance and pathogenesis of this virus needs further investigation.
The lot-sizing problem aims at determining the products to be produced and their quantities for each time period, which is a difficult problem in production planning. This problem becomes even more ...complicated when practical aspects such as limited production capacity, bill of materials, and item substitution are considered. In this paper, we study a new variant of the lot-sizing problem, called the multi-level capacitated lot-sizing problem with substitution and backorder. Unlike previous studies, this variant considers substitutions at both the product and component levels, which is based on the real needs of manufacturers to increase planning flexibility. Backorders are allowed, but should be delivered within a certain time limitation. We formulate this problem using a mathematical programming model. A matheuristic approach is proposed to solve the problem. This first generates an initial feasible solution using a relax-and-fix algorithm, and then improves it using a hybrid fix-and-optimise algorithm. The proposed algorithm is calibrated with a full factorial design of experiments, and its efficiency is well validated. Finally, through extensive numerical experiments, we analyse the properties of this new lot-sizing problem, such as the effect of substitution options, and the influence of backorder time limitation, and provide several useful managerial insights for manufacturing companies to save costs in production planning.
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•The cross-linked hierarchical CuO@CoNi LDH was facilely synthesized.•The cross-linked CuO@CoNi LDH growing on Cu foams has obviously stronger adhesive force.•The assembled ...CF@CuO@CoNi LDH 1–4//RGO asymmetric supercapacitor indicates extraordinary energy density.
Core-shell nanostructured compounds are considered as promising electrode materials for supercapacitors in virtue of their facile accessibility to active sites and high electrical conductivity, yet always limited by low capacity or poor cyclic stability because of the weak combination or shedding of active materials from the substrate. To address this issue, we first synthesize three-dimensional (3D) CuO cross-linked nanosheet aggregates grown on Cu foams (CF) by wet chemical oxidation, and further demonstrate the growth of ultra-thin cobalt-nickel layered double hydroxides (CoNi LDH) onto the core of 3D CuO cross-linked nanosheet aggregates by electrodeposition. In this way, we find that the cross-linked CuO@CoNi LDH growing on Cu foams has stronger adhesive force. The as-prepared core-shell nanohybrid (CF@CuO@CoNi LDH) is featured with a high specific capacity (319.4 mAh·g−1 at 1 A·g−1), excellent rate performance and long cycling stability. The as-assembled CF@CuO@CoNi LDH 1–4//RGO asymmetric supercapacitor (ASC) delivers an ultra-high energy density of 92.5 Wh·kg−1 at a power density of 400 W·kg−1, as well as an excellent cycling performance with capacitance retention of 83.8% after 8000 cycles at 5 A·g−1. These results indicate that the cross-linked hybrid is a high-performance electrode material for supercapacitors, and could provide new insight into the synthesis of novel core-shell nanomaterials.
Background and Aim
The portal pressure gradient (PPG) is a useful predictor of portal hypertension (PH) related complications. We previously showed the feasibility and safety of endoscopic ultrasound ...guided PPG measurement (EUS‐PPG). Now EUS‐guided liver biopsy (EUS‐bx) has been shown to be a safe and effective alternative to percutaneous or Interventional Radiology‐guided liver biopsy for the diagnosis of chronic liver disease (CLD). We aimed to evaluate the correlation between PPG and clinical markers of PH, and assess the feasibility and safety of concomitant, single session EUS‐PPG and EUS‐bx.
Methods
This was a retrospective study of patients undergoing EUS‐PPG for CLD at a single tertiary endoscopy center between February 2014 and March 2020. EUS‐PPG was performed using a 25‐gauge needle and compact manometer. Data analysis was performed with SAS version 9.4.
Results
Eighty‐three patients underwent EUS‐PPG with 100% technical success. The mean PPG was 7.06 mmHg (SD 6.09, range 0–27.3). PPG was higher in patients with (vs without) clinical features of cirrhosis (9.46 vs 3.61 mmHg, P < 0.0001), esophageal or gastric varices (13.88 vs 4.34 mmHg, P < 0.0001), and thrombocytopenia (9.25 vs 4.71 mmHg, P = 0.0022). In the 71 patients (85.5%) who underwent EUS‐bx, 70 (98.6%) specimens were deemed adequate by the pathologist for histologic diagnosis. There were no early or late major adverse events.
Conclusion
EUS‐PPG correlates well with clinical markers of PH. EUS‐bx can be performed safely during the same session as EUS‐PPG, providing a comprehensive endoscopic evaluation of the patient with CLD.
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