Showing papers by "Lei Zhang published in 2023"
TL;DR: In this article , the extracellular vesicle (EV)-mediated cell-to-cell transmission of SARS-CoV-2, which facilitates SARS CoV2 to escape from neutralizing antibodies, is investigated.
Abstract: Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic. Antibody resistance dampens neutralizing antibody therapy and threatens current global Coronavirus (COVID-19) vaccine campaigns. In addition to the emergence of resistant SARS-CoV-2 variants, little is known about how SARS-CoV-2 evades antibodies. Here, we report a novel mechanism of extracellular vesicle (EV)-mediated cell-to-cell transmission of SARS-CoV-2, which facilitates SARS-CoV-2 to escape from neutralizing antibodies. These EVs, initially observed in SARS-CoV-2 envelope protein-expressing cells, are secreted by various SARS-CoV-2-infected cells, including Vero E6, Calu-3, and HPAEpiC cells, undergoing infection-induced pyroptosis. Various SARS-CoV-2-infected cells produce similar EVs characterized by extra-large sizes (1.6–9.5 μm in diameter, average diameter > 4.2 μm) much larger than previously reported virus-generated vesicles. Transmission electron microscopy analysis and plaque assay reveal that these SARS-CoV-2-induced EVs contain large amounts of live virus particles. In particular, the vesicle-cloaked SARS-CoV-2 virus is resistant to neutralizing antibodies and able to reinfect naïve cells independent of the reported receptors and cofactors. Consistently, the constructed 3D images show that intact EVs could be taken up by recipient cells directly, supporting vesicle-mediated cell-to-cell transmission of SARS-CoV-2. Our findings reveal a novel mechanism of receptor-independent SARS-CoV-2 infection via cell-to-cell transmission, provide new insights into antibody resistance of SARS-CoV-2 and suggest potential targets for future antiviral therapeutics.
6 citations
6 citations
TL;DR: In this article , a nanoscale hollow sphere hydrolysis catalyst with low catalytic energy consumption, long catalytic lifetime and high conversion COS efficiency was proposed, which was shown to have high conversion efficiency.
Abstract: A nanoscale hollow sphere hydrolysis catalyst with low catalytic energy consumption, long catalytic lifetime and high conversion COS efficiency.
5 citations
TL;DR: In this article , the nano-modifiers (GOs-CS-Ca2+)-modified epoxy asphalt were analyzed through macro and micro tests, including tensile, cyclic, and stress relaxation tests.
Abstract: In order to solve the current problem of insufficient toughness of epoxy asphalt and immiscibility between resin and asphalt binder (not aged) in epoxy asphalt, nanomodifiers (GOs-CS-Ca2+) were prepared by a biomimetic mechanism from chitosan (CS), calcium ions (Ca2+), and graphene oxide nanoplatelets (GOs). In GOs-CS-Ca2+, CS connects GOs through calcium ion coordination bonds and amide bonds. GOs-CS-Ca2+-modified epoxy asphalt was prepared by directly adding different percentages of GOs-CS-Ca2+ to epoxy asphalt. Then, the properties of GOs-CS-Ca2+-modified epoxy asphalt were analyzed through macro and micro tests. The macroscopic tests included tensile, cyclic, and stress relaxation tests. The microscopic tests included fluorescence microscopy (FM) and scanning electron microscopy (SEM) tests. Tensile tests showed that after adding 0.05% GOs-CS-Ca2+ to the total mass of epoxy asphalt, the tensile strength and fracture toughness of epoxy asphalt increased by 29.6% and 20%. Cyclic tensile tests showed that GOs-CS-Ca2+-modified epoxy asphalt had greater consuming work recovery capacity, and stress relaxation tests showed that the addition of GOs-CS-Ca2+ delayed the relaxation modulus decline of epoxy asphalt. The infrared spectrum, scanning electron microscope, X-ray diffraction, and Raman spectra of GOs-CS-Ca2+ in the micro test can show the successful synthesis of GOs-CS-Ca2+. FM and SEM of GOs-CS-Ca2+-modified epoxy asphalt showed that the addition of GOs-CS-Ca2+ could reduce the particle-size distribution of the asphalt phase in epoxy resin and establish a miscible bridge between epoxy resin and asphalt, which led to the improvement of macroscopic mechanical properties of GOs-CS-Ca2+-modified epoxy asphalt. Finally, the modification mechanism of GOs-CS-Ca2+-modified epoxy asphalt was proposed by combining macroscopic and microscopic test results.
4 citations
TL;DR: Wang et al. as discussed by the authors proposed an algorithm named Sharpness-Aware Gradient Matching (SAGM) to align the gradient directions between the empirical risk and the perturbed loss.
Abstract: The goal of domain generalization (DG) is to enhance the generalization capability of the model learned from a source domain to other unseen domains. The recently developed Sharpness-Aware Minimization (SAM) method aims to achieve this goal by minimizing the sharpness measure of the loss landscape. Though SAM and its variants have demonstrated impressive DG performance, they may not always converge to the desired flat region with a small loss value. In this paper, we present two conditions to ensure that the model could converge to a flat minimum with a small loss, and present an algorithm, named Sharpness-Aware Gradient Matching (SAGM), to meet the two conditions for improving model generalization capability. Specifically, the optimization objective of SAGM will simultaneously minimize the empirical risk, the perturbed loss (i.e., the maximum loss within a neighborhood in the parameter space), and the gap between them. By implicitly aligning the gradient directions between the empirical risk and the perturbed loss, SAGM improves the generalization capability over SAM and its variants without increasing the computational cost. Extensive experimental results show that our proposed SAGM method consistently outperforms the state-of-the-art methods on five DG benchmarks, including PACS, VLCS, OfficeHome, TerraIncognita, and DomainNet. Codes are available at https://github.com/Wang-pengfei/SAGM.
3 citations
TL;DR: In this paper , density functional theory simulations were addressed to predict the electronic structure regulations of CoFc-MOF by nickel doping, which demonstrated that the well-proposed CoNiFc -MOFs delivered a small energy barrier, promoted conductivity, and well-regulated d-band center.
Abstract: The ferrocene (Fc)-based metal–organic frameworks (MOFs) are regarded as compelling platforms for the construction of efficient and robust oxygen evolution reaction (OER) electrocatalysts due to their superior conductivity and flexible electronic structure. Herein, density functional theory simulations were addressed to predict the electronic structure regulations of CoFc-MOF by nickel doping, which demonstrated that the well-proposed CoNiFc-MOFs delivered a small energy barrier, promoted conductivity, and well-regulated d-band center. Inspired by these, a series of sea-urchin-like CoNiFc-MOFs were successfully synthesized via a facile solvothermal method. Moreover, the synchrotron X-ray and X-ray photoelectron spectroscopy measurements manifested that the introduction of nickel could tailor the electronic structure of the catalyst and induce the directional transfer of electrons, thus optimizing the rate-determining step of *O → *OOH during the OER process and yielding decent overpotentials of 209 and 252 mV at 10 and 200 mA cm−2, respectively, with a small Tafel slope of 39 mV dec−1. This work presents a new paradigm for developing highly efficient and durable MOF-based electrocatalysts for OER.
2 citations
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TL;DR: In this paper, the effect of next-nearest neighbor hopping (NNNH) on the reentrant localization phenomenon was studied and it was shown that the Reentrant can still persist within a range of NNNH both in Hermitian and non-Hermitian cases.
Abstract: Recently, the exciting reentrant localization transition phenomenon was found in a one-dimensional dimerized lattice with staggered quasiperiodic potentials. Usually, long-range hopping is typically important in actual physical systems. In this work, we study the effect of next-nearest neighbor hopping (NNNH) on the reentrant localization phenomenon. Due to the presence of NNNH, the broken chiral symmetry is further enhanced and the localization properties of electron states in the upper and lower bands become quite different. It is found that the reentrant localization can still persist within a range of NNNH both in Hermitian and non-Hermitian cases. Eventually, the reentrant localization disappears as the strength of NNNH increases to some extent, since the increasing NNNH weakens the dimerization of the system and destroys its competition with the quasiperiodic disorder. Our work thus reveals the effect of long-range hopping in the reentrant localization phenomenon and deepens its physical understanding.
2 citations
TL;DR: In this article , a metasurface-like metallic waveguide array (MWA) is proposed to address this by measuring both the phase difference and amplitude ratio of its two orthogonal components based on generation and interference of polarization multiplexing vortex beams.
Abstract: Determination of polarization states of electromagnetic waves plays a crucial role in photonic applications. However, it is very challenging to determine the polarization state of continuous terahertz (THz) waves. Here, a metasurface‐like metallic waveguide array (MWA) is proposed to address this by measuring both the phase difference and amplitude ratio of its two orthogonal components based on generation and interference of polarization‐multiplexing vortex beams. When a full‐polarized THz wave passes through the MWA, its two orthogonal components will be converted into +1st‐ and −1st‐order Bessel vortex beams, respectively. Their projection components in a proper polarized direction can interfere with each other, and their initial phase difference can be measured in real‐time owing to its linear relationship with the azimuth of the dark fringe in interference patterns. The two Bessel beams can be further collected separately using a linear polarizer to obtain their amplitude ratio. Therefore, the polarization state of incident waves can be determined with both the phase difference and amplitude ratio. The proposed method enables a convenient polarization determination of continuous THz waves and has great potential for developing polarization‐dependent investigations and applications in THz detection, communication, and sensing.
2 citations
TL;DR: In this paper , a single EuInO3 crystal was obtained for the first time by the laser floating zone method and the presence of ferroelectricity was revealed by polarization-electric field hysteresis loops of the bulk single crystal.
Abstract: RInO3 (R: rare-earth element) has drawn unprecedented research attention due to its geometric ferroelectricity and spin liquid state. However, the structure–property relationship needs further investigation based on well-developed single crystals. A EuInO3 crystal was obtained for the first time by the laser floating zone method. The presence of ferroelectricity was revealed by polarization–electric field hysteresis loops of the bulk EuInO3 single crystal. Moreover, interesting topological vortex domains were revealed by vertical piezoresponse force microscopy. The lattice dynamics of EuInO3 was probed by correlating various Raman modes with the structural distortion of the unit cell. The improper ferroelectricity and topological ferroelectric vortices of the EuInO3 crystal provide great potential for vortex memory devices.
2 citations
TL;DR: In this paper , the authors summarize the recent achievements of discrete polymers in optical imaging, magnetic resonance (MR) imaging, and therapeutic applications, and summarize the representative methods used to synthesize discrete and disperse polymers.
2 citations
TL;DR: In this article , the authors constructed an O−C diagram and analyzed the variations in the orbital period of the eclipsing binary WX Cen, which is most likely one of the Galactic counterparts of compact binary supersoft X-ray sources as a member of the V Sagittae class.
Abstract: WX Cen is most likely one of the Galactic counterparts of compact binary supersoft X-ray sources as a member of the V Sagittae class, in which mass is transferred from a donor secondary to a massive white dwarf primary via an accretion disk. Based on the photometric observations from the TESS space telescope and AAVSO database, 218 times of light minimum were determined. By collecting all available eclipse timings of WX Cen from the literature together with those newly determined, we constructed an O−C diagram and analyzed the variations in the orbital period of the eclipsing binary. It is confirmed that the orbital period is continuously decreasing and the rate of the change in the orbital period is revised to Ṗ=−4.4(4)×10−7dayyr−1=−0.038(3)syr−1 . The mass of the donor secondary is estimated as M s ∼ 0.6 M ⊙, when the white dwarf mass is M WD ∼ 0.9 M ⊙. By considering a conservative mass transfer from the secondary to the primary, the orbital period of WX Cen should be increasing, which is opposite to the observed continuous decrease. Therefore, the decrease in the period can be plausibly explained as the result of angular momentum loss (AML) via magnetic wind from the secondary and/or from the accretion disk. The AML causes the donor secondary with a low mass to continually be filling its critical Roche lobe and transferring material to the white dwarf. In this way, the evolution of WX Cen is dominated by the magnetic wind and continuously radiating supersoft X-rays.
TL;DR: In this paper , the representative basic and clinical anti-obesity studies associated with the homeostasis of GM regulated by HM including active components, single herb and herbal formulae were summarized and discussed.
TL;DR: Wang et al. as mentioned in this paper evaluated the early hematologic response and long-term outcomes of a large cohort of patients with SAA who received antihuman T lymphocyte porcine immunoglobulin (p-ATG) plus cyclosporine (CsA) as first-line therapy from 2010 to 2019.
Abstract: Background: Antihuman T lymphocyte porcine immunoglobulin (p-ATG) has been the most common ATG preparation in immunosuppressive therapy (IST) in Chinese patients with severe aplastic anemia (SAA) since 2009. Objectives: This study aimed to evaluate the early hematologic response and long-term outcomes of a large cohort of patients with SAA who received p-ATG plus cyclosporine (CsA) as first-line therapy from 2010 to 2019. Design: This is a single-center retrospective study of medical records. Methods: We analyzed the data of 1023 consecutive patients with acquired aplastic anemia (AA) who underwent p-ATG combined with CsA as a first-line IST treatment from 2010 to 2019 at our department. Results: The median age of the patients was 24 (4–75) years, and the median follow-up time was 57.2 months (3 days–137.5 months). There was an early mortality rate of 2.8% with a median death time of 0.9 months (3 days–2.9 months). The overall response rates were 40.6% and 56.1% at 3 and 6 months, respectively. The 5-year cumulative incidences of relapse and clonal evolution were 9.0% [95% confidence interval (CI) = 4.2–16.0%] and 4.5% (95% CI = 1.4–10.6%), respectively. The 5-year overall survival (OS) and event-free survival rates were 83.7% (95% CI = 81.1–86.0%) and 50.4% (95% CI = 47.1–53.5%), respectively. Conclusion: p-ATG combined with CsA for the treatment of AA is effective and safe, and p-ATG can be used as an alternative ATG preparation for the standard IST regimen in areas in which h-ATG is not available.
TL;DR: Zhang et al. as mentioned in this paper proposed DiffHOI, a novel HOI detection scheme grounded on a pre-trained text-image diffusion model, which enhances the detector's performance via improved data diversity and HOI representation.
Abstract: This paper investigates the problem of the current HOI detection methods and introduces DiffHOI, a novel HOI detection scheme grounded on a pre-trained text-image diffusion model, which enhances the detector's performance via improved data diversity and HOI representation. We demonstrate that the internal representation space of a frozen text-to-image diffusion model is highly relevant to verb concepts and their corresponding context. Accordingly, we propose an adapter-style tuning method to extract the various semantic associated representation from a frozen diffusion model and CLIP model to enhance the human and object representations from the pre-trained detector, further reducing the ambiguity in interaction prediction. Moreover, to fill in the gaps of HOI datasets, we propose SynHOI, a class-balance, large-scale, and high-diversity synthetic dataset containing over 140K HOI images with fully triplet annotations. It is built using an automatic and scalable pipeline designed to scale up the generation of diverse and high-precision HOI-annotated data. SynHOI could effectively relieve the long-tail issue in existing datasets and facilitate learning interaction representations. Extensive experiments demonstrate that DiffHOI significantly outperforms the state-of-the-art in regular detection (i.e., 41.50 mAP) and zero-shot detection. Furthermore, SynHOI can improve the performance of model-agnostic and backbone-agnostic HOI detection, particularly exhibiting an outstanding 11.55% mAP improvement in rare classes.
TL;DR: In this paper , the effect of IL-35 on immune cell infiltration in grafts and secondary lymphoid organs was examined using mass cytometry, flow cytometry and immunofluorescence.
Abstract: BACKGROUND
Interleukin-35 (IL-35), secreted by regulatory T cells (Treg) and B cells, is immunosuppressive under both physiological and pathological conditions. However, the role of IL-35 in all responses has yet to be investigated. Here, we demonstrate that IL-35 protects allografts by stabilizing the Treg phenotype and suppressing CD8+ T-cell activation in a mouse heart transplantation model.
METHODS
The effect of IL-35 on immune cell infiltration in grafts and secondary lymphoid organs was examined using mass cytometry, flow cytometry, and immunofluorescence. Moreover, using quantitative real-time polymerase chain reaction, flow cytometry, and phospho-flow assays, we demonstrated that IL-35 maintains Treg phenotypes to restrain CD8+ T cells via the gp130/signal transducer and activator of transcription 1 pathway.
RESULTS
Mass cytometry analysis of intragraft immune cells showed that IL-35 decreased CD8+ T-cell infiltration and increased Foxp3 and IL-35 expressions in Treg. In vitro, we demonstrated that IL-35 directly promoted Treg phenotypic and functional stability and its IL-35 secretion, generating a positive feedback loop. However, Treg are required for IL-35 to exert its suppressive effect on CD8+ T cells in vitro. After depleting Treg in the recipient, IL-35 did not prolong graft survival or decrease CD8+ T-cell infiltration. Mechanistically, we found that IL-35 sustained Treg stability via the gp130/signal transducer and activator of transcription 1 signaling pathway.
CONCLUSIONS
Our findings highlight that IL-35 stabilizes the Treg phenotype to ameliorate CD8+ T-cell infiltration in the allograft, which has never been described in the transplanted immunological milieu.
TL;DR: In this article , a Bayesian sparsity reconstruction optimization is developed for jointly ambiguity resolving and resolution enhancement in the azimuth angle image domain, where the spatial structure of the target in the preliminary image domain is used as the signal sparsity with prior information to solve the constrained optimization problem for FLMC-SAR image resolution enhancement.
Abstract: Forward-looking multi-channel synthetic aperture radar (FLMC-SAR) is of the capability to achieve unambiguous 2-D images in the forward-looking slight direction. FLMC-SAR imagery usually suffers from relatively low spatial resolution as only limited Doppler diversity can be generated from the synthetic aperture. In this article, a sparsity-driven resolution enhancement algorithm is proposed to improve the resolution FLMC-SAR image of the forward-looking area. Different from conventional beamforming processing to resolve the FLMC-SAR left–right ambiguity, a Bayesian sparsity reconstruction optimization is developed for jointly ambiguity resolving and resolution enhancement in the azimuth angle image domain. The spatial structure of the target in the preliminary image domain is used as the signal sparsity with prior information to solve the constrained optimization problem for FLMC-SAR image resolution enhancement. A local least square estimator of the prior noise and signal statistics in the FLMC-SAR nonisotropic image is established in terms of determining the sparsity weight parameter. Extensive simulation and real FLMC-SAR data experiments confirm that the proposed algorithm is capable of achieving the unambiguous and resolution-enhanced FLMC-SAR image.
TL;DR: In this paper , the authors investigated whether postoperative adjuvant transcatheter arterial chemoembolization (TACE) treatment in wide and narrow-margin groups could improve the long-term prognosis of patients with hepatocellular carcinoma (HCC).
Abstract: BACKGROUND
The aim of this study was to investigate whether postoperative adjuvant transcatheter arterial chemoembolization (TACE) treatment in wide- and narrow-margin groups could improve the long-term prognosis of patients with hepatocellular carcinoma (HCC).
MATERIALS AND METHODS
A total of 670 patients with HCC who underwent radical hepatectomy from January 2016 to December 2017 were enrolled, including 397 patients and 273 patients in the wide- and narrow-margin groups. Recurrence-free survival (RFS) and overall survival (OS) outcomes were compared in the wide-margin and narrow-margin groups with and without adjuvant TACE postoperatively, respectively. Propensity score matching (PSM) analysis was used to match patients between TACE and no TACE groups in a 1:1 ratio.
RESULTS
The wide-margin resection was associated with better RFS and OS rates than narrow-margin resection for patients with HCC. Patients with postoperative adjuvant TACE had a better RFS and OS than patients without postoperative adjuvant TACE in the narrow-margin group and reduced the intrahepatic recurrence rate (39.1% vs. 52.6%, P = .036) and the local recurrence rate in the liver (11.2% vs. 21.4%, P = .032). But postoperative adjuvant TACE did not alter recurrence and survival outcomes in the wide-margin group. Similar results were noted after propensity score matching (PSM).
CONCLUSION
The wide-margin resection had better RFS and OS than the narrow-margin resection for patients with HCC. Postoperative adjuvant TACE was associated with reduced recurrence and improved OS after narrow-margin resection, but was not effective in the wide-margin resection.
TL;DR: In this paper , the aberration of BNST's functional connectivity and its age dependence in adolescents with SAD was examined, showing an age-dependent decrease in functional connectivity between the right BNst and left amygdala during movie viewing.
TL;DR: In this paper , the authors discuss miniaturized platforms that allow the minimally invasive and rapid detection and analysis of circulating biomarkers, accounting for their differences in size, concentration and molecular composition.
Abstract: Diverse (sub)cellular materials are secreted by cells into the systemic circulation at different stages of disease progression. These circulating biomarkers include whole cells, such as circulating tumour cells, subcellular extracellular vesicles and cell-free factors such as DNA, RNA and proteins. The biophysical and biomolecular state of circulating biomarkers carry a rich repertoire of molecular information that can be captured in the form of liquid biopsies for disease detection and monitoring. In this Review, we discuss miniaturized platforms that allow the minimally invasive and rapid detection and analysis of circulating biomarkers, accounting for their differences in size, concentration and molecular composition. We examine differently scaled materials and devices that can enrich, measure and analyse specific circulating biomarkers, outlining their distinct detection challenges. Finally, we highlight emerging opportunities in biomarker and device integration and provide key future milestones for their clinical translation.
TL;DR: In this paper , the authors investigated the response rate of hetrombopag combined with IST as first-line treatment in severe aplastic anaemia (SAA) patients.
Abstract: Hetrombopag, a small molecular thrombopoietin-receptor agonist, has shown encouraging efficiency in immunosuppressive therapy refractory or relapsed severe aplastic anaemia. To investigate the response rate of hetrombopag combined with IST as first-line treatment, we designed a prospective pilot study including 32 patients with SAA treated with anti-human T lymphocyte porcine immunoglobulin (p-ATG), cyclosporine, and hetrombopag. In addition, 96 patients with SAA treated with p-ATG and cyclosporine alone were matched as controls. In total, 21.9% of patients treated with hetrombopag achieved complete response (CR) at 3 months, while 5.2% of patients achieved CR in the control group (P = 0.005). At 6 months, the CR rates were 34.4% in the hetrombopag group and 14.6% in the control group (P = 0.015). The overall response rates at 6 months were 68.7% and 50.0% in the hetrombopag and control groups, respectively. The median time to haematologic response was 56 days and 77 days, and to CR was 96 days and 214 days in the hetrombopag and control groups, respectively. In conclusion, adding hetrombopag to IST as first-line treatment resulted in faster and better haematologic response in SAA.
TL;DR: In this paper, the authors proposed a one-round dynamic authenticated asymmetric group key agreement with sender non-repudiation and privacy (DAAGKAwSNP) protocol.
Abstract: Group-oriented applications generally support communications for multiple entities (e.g., users and/or devices) through open networks. Typical requirements of group communications include secrecy, authentication, sender non-repudiation, and sender privacy. However, conventional approaches such as group key agreement and broadcast encryption are generally not designed to achieve all these requirements simultaneously or efficiently. In this article, we propose a one-round dynamic authenticated asymmetric group key agreement with sender non-repudiation and privacy (DAAGKAwSNP) protocol. A key building block of our DAAGKAwSNP protocol is our proposed batch multi-signature scheme with strong unforgeability. We prove that the DAAGKAwSNP protocol achieves secrecy under chosen ciphertext attacks – CCA, assuming the intractability of the computational Diffie-Hellman and k-Bilinear Diffie-Hellman exponent problem. We also evaluate DAAGKAwSNP’s performance to demonstrate its utility.
TL;DR: In this article , the authors investigated the efficacy of decitabine in combination with rituximab, cisplatin, cytarabine, dexamethasone (RDHAP) in relapsed/refractory diffuse large B-cell lymphoma (R/R•DLBCL).
Abstract: There is an urgent need for effective treatment of patients with relapsed/refractory diffuse large B‐cell lymphoma (R/R‐DLBCL). This trial investigated the efficacy of decitabine in combination with rituximab, cisplatin, cytarabine, dexamethasone (RDHAP) in R/R‐DLBCL.
TL;DR: Li et al. as discussed by the authors provided evidence supporting the negative effect of corporate party organizations on Chinese state-owned enterprises' stock price crash risk and showed that the restraining effect only exists in companies with strong promotion incentives for senior executives, supporting the governance role of the corporate party committee.
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TL;DR: In this article , a fully digital soft-switching control based on the variable off-time and deadtime with an optimized designed digital control frequency was proposed to achieve the zero voltage switching of switches for inverters.
Abstract: Controlling current at critical conduction mode (CRM) is an effective way to achieve zero voltage switching (ZVS) of switches for inverters. However, the higher reverse inductor current and fixed deadtime in fully digital soft-switching control, such as reverse current boundary-based (RCB-based) schemes, lead to higher rms inductor current and higher power losses. Besides, the digital control frequency for CRM-based inverters is not well designed, resulting in the contradiction between high performance and high digital calculation burden. Therefore, this article proposes a fully digital soft-switching control based on the variable off-time and deadtime with an optimized designed digital control frequency. First, the variable off-time and deadtime design guidelines are addressed with the established mathematical model of the CRM-based inverter. Then, the power losses of the inverter with different digital control frequencies and control schemes are quantitatively analyzed and compared. Finally, a 1 kW single-phase three-level neutral-point-clamped grid-tied inverter was built. Experimental results show that the proposed scheme can achieve the ZVS turn-on of switches without additional components, and the maximum efficiency is 98.3%. Compared with the RCB-based scheme, the proposed method achieves higher efficiency with the same hardware cost.
TL;DR: In this article , a series of 2,3,5-substituted [1,2,4]-thiadiazole analogs were discovered to be able to inhibit 3CLpro as non-peptidomimetic covalent binders at submicromolar levels, with IC50 values ranging from 0.118 to 0.582 μM.
Abstract: The 3C-like protease (3CLpro) is essential for the replication and transcription of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), making it a promising target for the treatment of corona virus disease 2019 (COVID-19). In this study, a series of 2,3,5-substituted [1,2,4]-thiadiazole analogs were discovered to be able to inhibit 3CLpro as non-peptidomimetic covalent binders at submicromolar levels, with IC50 values ranging from 0.118 to 0.582 μM. Interestingly, these compounds were also shown to inhibit PLpro with the same level of IC50 values, but had negligible effect on proteases such as chymotrypsin, cathepsin B, and cathepsin L. Subsequently, the antiviral abilities of these compounds were evaluated in cell-based assays, and compound 6g showed potent antiviral activity with an EC50 value of 7.249 μM. It was proposed that these compounds covalently bind to the catalytic cysteine 145 via a ring-opening metathesis reaction mechanism. To understand this covalent-binding reaction, we chose compound 6a, one of the identified hit compounds, as a representative to investigate the reaction mechanism in detail by combing several computational predictions and experimental validation. The process of ring-opening metathesis was theoretically studied using quantum chemistry calculations according to the transition state theory. Our study revealed that the 2,3,5-substituted [1,2,4]-thiadiazole group could covalently modify the catalytic cysteine in the binding pocket of 3CLpro as a potential warhead. Moreover, 6a was a known GPCR modulator, and our study is also a successful computational method-based drug-repurposing study.
TL;DR: In this paper , fly ash is used as the main raw material and bentonite was used as an auxiliary material in the catalyst to improve the compressive strength and denitrification performance of the fly ash.
Abstract: Fly ash is a massive industrial waste. Owing to the abundance of oxides, such as SiO2 and Al2O3, fly ash is considered a high value material. In this study, we assessed its application in the industrial deoxidation of nitrogen oxides, a major environmental pollutant, using the selective catalytic reduction technology. Fly ash was used as the main raw material and bentonite was used as an auxiliary material in the catalyst. Silica sol, starch, and glycerol were added to improve the compressive strength and denitrification performance of the catalyst. The use of silica sol as a binder improved the compressive strength of the catalyst due to the production of Si–O–Si. In addition, the availability of acidic functional groups could improve the denitrification performance of the catalyst. The optimal dosages of the additives were as follows: 6% silica sol, 6% starch, and 5% glycerol. Under these conditions, the catalyst formation was the easiest, the cracks were the least, the compressive strength of the catalyst reached 1434 kPa, and the denitrification performance improved. The findings presented here are relevant for the development of an economical and practicable solution for tackling environmental pollution caused by nitrogen oxides.
TL;DR: In this paper , the effect of consecutive treatment with tDCS for seven days on rats after Middle cerebral artery occlusion/reperfusion (MCAO/R) surgery was studied.
TL;DR: An efficient synthesis approach for one dimension benzo[1,2b:4,5b]-dithiophene based graphdiyne (1D-BDT-GDY) has been developed as discussed by the authors .
Abstract: An efficient synthesis approach for one dimension benzo[1,2-b:4,5-b']dithiophene based graphdiyne (1D-BDT-GDY) has been developed. The 1D-BDT-GDY shows enhanced electrochemical conductivity and electrocatalytic activity for the drug chloramphenicol (CAP) adsorption, and...
TL;DR: In this paper , a range-compressed domain motion compensation (RCMOCO) algorithm is introduced for the range-dependent motion errors and residual range curvature is neglected, causing the undesired range cell migration.
Abstract: For widefield synthetic aperture radar (SAR) imag ing, range-dependent motion errors and range curvature are the main obstacle for range cell migration correction (RCMC) and azimuth focusing. The parametric polar format algorithm (PPFA) can handle the range-dependent motion errors after RCMC, but the Non-system range cell migration (NsRCM) is ignored. Furthermore, the residual range curvature is neglected, causing the undesired range cell migration. In this paper, a novel widefield PPFA (WPPFA) is developed for widefield spotlight SAR imaging. A precise range-compressed domain motion compensation (RCMOCO) algorithm is introduced for the range-dependent motion errors. It can precisely compensate for the range-dependent motion errors before RCMC. After RCMC, an accurate range curvature correction algorithm is carried out, accelerated by the scaling Fourier transform (SFT). Based on these improvements, an azimuth wavenumber resampling integrating azimuth-variant phase error compensation is implemented to achieve well-focused images. Finally, extensive simulated and real-measured SAR data have validated the algorithm's effectiveness.