The low-cost room-temperature sodium-sulfur battery system is arousing extensive interest owing to its promise for large-scale applications. Although significant efforts have been made, resolving low ...sulfur reaction activity and severe polysulfide dissolution remains challenging. Here, a sulfur host comprised of atomic cobalt-decorated hollow carbon nanospheres is synthesized to enhance sulfur reactivity and to electrocatalytically reduce polysulfide into the final product, sodium sulfide. The constructed sulfur cathode delivers an initial reversible capacity of 1081 mA h g
with 64.7% sulfur utilization rate; significantly, the cell retained a high reversible capacity of 508 mA h g
at 100 mA g
after 600 cycles. An excellent rate capability is achieved with an average capacity of 220.3 mA h g
at the high current density of 5 A g
. Moreover, the electrocatalytic effects of atomic cobalt are clearly evidenced by operando Raman spectroscopy, synchrotron X-ray diffraction, and density functional theory.
The 3,3′‐disubstituted oxindole structural motif is a prominent feature in many alkaloid natural products, which include all kinds of tetrasubstituted carbon stereocenters, spirocyclic or not, ...all‐carbon or heteroatom‐containing. The catalytic asymmetric synthesis of the tetrasubstituted carbon stereocenter at the C‐3 position of the oxindole framework integrates new synthetic methods and chiral catalysts, reflects the latest achievements in asymmetric catalysis, and facilitates the synthesis of sufficient quantities of related compounds as potential medicinal agents and biological probes. This review summarizes the recent progress in this area, and applications in the total synthesis of related bioactive compounds.
Label Enhancement for Label Distribution Learning Xu, Ning; Liu, Yun-Peng; Geng, Xin
IEEE transactions on knowledge and data engineering,
2021-April-1, 2021-4-1, Letnik:
33, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Label distribution is more general than both single-label annotation and multi-label annotation. It covers a certain number of labels, representing the degree to which each label describes the ...instance. The learning process on the instances labeled by label distributions is called label distribution learning (LDL). Unfortunately, many training sets only contain simple logical labels rather than label distributions due to the difficulty of obtaining the label distributions directly. To solve this problem, one way is to recover the label distributions from the logical labels in the training set via leveraging the topological information of the feature space and the correlation among the labels. Such process of recovering label distributions from logical labels is defined as label enhancement (LE), which reinforces the supervision information in the training sets. This paper proposes a novel LE algorithm called Graph Laplacian Label Enhancement (GLLE). Experimental results on one artificial dataset and fourteen real-world LDL datasets show clear advantages of GLLE over several existing LE algorithms. Furthermore, experimental results on eleven multi-label learning datasets validate the advantage of GLLE over the state-of-the-art multi-label learning approaches.
Chiral tertiary alcohols are an important class of organic compounds which have found wide applications in both academia and industry. Therefore, various synthetic strategies towards these compounds ...have already been developed. Among them, the catalytic asymmetric addition of carbon nucleophiles to ketones is the most desirable route owing to its straightforwardness as well as its economic, efficient and versatile advantages. This review summarizes and discusses the recent achievements in this field classified according to the reaction types. Special attention is paid to the mechanisms, advantages and limitations of each reaction. In addition, the applications of these catalytic processes in the synthesis of related natural products, pharmaceuticals or their analogues are briefly discussed as well.
Dynamics of proteins in solutions include translational, rotational, and internal motions that are linked to different protein properties. Because most proteins are small with the sizes of just a few ...nanometers, the timescale for their short-time dynamics usually ranges from a few nanoseconds to a few hundreds of nanoseconds, during which a protein usually does not rotate too much. Protein short-time dynamics has been shown to be useful to study liquid theories, protein cluster formation, gelation transitions of concentrated protein systems, and protein internal motions. Neutron spin echo, which is able to measure protein motions with the right correlation time at the appropriate length scale, is ideally suitable to study the short-time dynamics of proteins in solutions. Here, we review recent activities of using neutron spin echo to study the protein short-time motions. Despite all progresses, there are still both theoretical and experimental challenges to exploit the full capability of neutron spin echo to study protein dynamics.
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The coronavirus disease 2019 (COVID-19) outbreak caused by the severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2 virus) has been sustained in China since December 2019, and has become a ...pandemic. The mental health of frontline medical staff is a concern. In this study, we aimed to identify the factors influencing medical worker anxiety in China during the COVID-19 outbreak. We conducted a cross-sectional study to estimate the prevalence of anxiety among medical staff in China from 10 February 2020 to 20 February 2020 using the Zung Self-rating Anxiety Scale (SAS) to assess anxiety, with the criteria of normal (⩽49), mild (50-59), moderate (60-70) and severe anxiety (⩾70). We used multivariable linear regression to determine the factors (e.g. having direct contact when treating infected patients, being a medical staff worker from Hubei province, being a suspect case) for anxiety. We also used adjusted models to confirm independent factors for anxiety after adjusting for gender, age, education and marital status. Of 512 medical staff in China, 164 (32.03%) had had direct contact treating infected patients. The prevalence of anxiety was 12.5%, with 53 workers suffering from mild (10.35%), seven workers suffering from moderate (1.36%) and four workers suffering from severe anxiety (0.78%). After adjusting for sociodemographic characteristics (gender, age, education and marital status), medical staff who had had direct contact treating infected patients experienced higher anxiety scores than those who had not had direct contact (β value = 2.33, confidence interval (CI) 0.65-4.00; P = 0.0068). A similar trend was observed in medical staff from Hubei province, compared with those from other parts of China (β value = 3.67, CI 1.44-5.89; P = 0.0013). The most important variable was suspect cases with high anxiety scores, compared to non-suspect cases (β value = 4.44, CI 1.55-7.33; P = 0.0028). In this survey of hospital medical workers during the COVID-19 outbreak in China, we found that study participants experienced anxiety symptoms, especially those who had direct clinical contact with infected patients; as did those in the worst affected areas, including Hubei province; and those who were suspect cases. Governments and healthcare authorities should proactively implement appropriate psychological intervention programmes, to prevent, alleviate or treat increased anxiety.
In this paper, broad multiband impedance matching networks (MBIMNs) are synthesized for frequency-dependent complex loads. The MBIMNs are derived from a multiband bandpass topology that is obtained ...by conducting multiple low-pass-bandpass transformations and by sharing one topology for all matching bands. The concept of a frequency-dependent voltage transformer is then used for generating a frequency-dependent load conductance, while the load susceptance is borrowed from the nearest susceptance unit of the topology. The resulted MBIMN contains several multimode resonators that are practically realized by parallel connections of series LCs and series connections of parallel LCs, and iterative methods are used for extracting the circuit parameters. Three dual-band examples and one triband example are designed and simulated, and two of them are fabricated and measured, with compared results sufficiently demonstrating the feasibility of the topologies and theories. Broad bandwidths referring to low reflection coefficients are observed. The topologies and methods can also be expected to realize more than three matching bands provided with enough convenience in circuit implementation. Multiband bandpass filtering is another important function of the matching networks.
Existing control techniques for rehabilitation robots commonly ignore robot dynamics by assuming a perfect inner control loop or are limited to rigid-joint robots. The dynamic stability of ...compliantly-actuated rehabilitation robots, consisting of the dynamics of both robot and compliant actuator, is not theoretically grounded. This paper presents an iterative learning impedance controller for rehabilitation robots driven by series elastic actuators (SEAs), where the control objective is specified as a desired impedance model. The desired impedance model is achieved in an iterative manner, which suits the repeating nature of patients’ task through therapeutic process and also guarantees the transient performance of robot. The stability of the overall system is rigorously proved with Lyapunov methods by taking into account both the robot and actuator dynamics. Experimental results are presented to illustrate the performance of the proposed iterative control scheme.
Dysregulated autophagy is associated with many pathological disorders such as cardiovascular diseases. Emerging evidence has suggested that circular RNAs (circRNAs) have important roles in some ...biological processes. However, it remains unclear whether circRNAs participate in the regulation of autophagy. Here we report that a circRNA, termed autophagy-related circular RNA (ACR), represses autophagy and myocardial infarction by targeting Pink1-mediated phosphorylation of FAM65B. ACR attenuates autophagy and cell death in cardiomyocytes. Moreover, ACR protects the heart from ischemia/reperfusion (I/R) injury and reduces myocardial infarct sizes. We identify Pink1 as an ACR target to mediate the function of ACR in cardiomyocyte autophagy. ACR activates Pink1 expression through directly binding to Dnmt3B and blocking Dnmt3B-mediated DNA methylation of Pink1 promoter. Pink1 suppresses autophagy and Pink1 transgenic mice show reduced myocardial infarction sizes. Further, we find that FAM65B is a downstream target of Pink1 and Pink1 phosphorylates FAM65B at serine 46. Phosphorylated FAM65B inhibits autophagy and cell death in the heart. Our findings reveal a novel role for the circRNA in regulating autophagy and ACR-Pink1-FAM65B axis as a regulator of autophagy in the heart will be potential therapeutic targets in treatment of cardiovascular diseases.
Objective
Radical lymph node dissection (LND) along the bilateral recurrent laryngeal nerve (RLN) is a surgically challenging procedure with a high rate of morbidity. Here, we assessed in a ...retrospective manner the adequacy of LND along the RLN performed with robot-assisted thoracoscopic esophagectomy (RATE) versus video-assisted thoracoscopic esophagectomy (VATE) in patients with esophageal squamous cell carcinoma (ESCC).
Methods
This was a single-center, retrospective, propensity-matched study. ESCC patients who underwent McKeown esophagectomy and bilateral RLN LND with a minimally invasive approach were divided into two groups according to the use of robot-assisted surgery or not (RATE vs VATE, respectively). Using propensity score matching, 34 balanced matched pairs were identified. The number of dissected nodes as well as the rates of RLN palsy and perioperative complications served as the main outcome measures.
Results
No conversion to open thoracotomy occurred in either group. Intraoperative blood loss and the need of blood transfusions did not show significant intergroup differences. The mean number of dissected nodes was similar in the two study groups, the only exception being the left RLN area. Specifically, the mean number of nodes removed from this region was 5.32 in the RATE group and 3.38 in patients who received VATE (
p
= 0.007). Notably, the RATE and VATE groups did not differ significantly with regard to rates of both RLN palsy (20.6 vs 29.4%, respectively,
p
= 0.401) and pulmonary complications (5.9 vs 17.6%, respectively,
p
= 0.259).
Conclusions
Compared with VATE, RATE resulted in a higher lymph node yield along the left RLN without increasing morbidity.
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