The history of the South China Craton and the constituent Yangtze and Cathaysia blocks are directly linked to Earth's Phanerozoic and Precambrian record of supercontinent assembly and dispersal. ...Exposed Archean rocks are limited to isolated fragments in the Yangtze Block that preserve a record of Meso- to Neo-Archean magmatism, sedimentation and metamorphism associated with a period of global craton formation and stabilization that corresponds with the assembly of the Kenor supercontinent/supercraton. However, there are insufficient data to link its history with other similar aged cratons. The tectonostratigraphic record in South China in the Paleoproterozoic, corresponding with the assembly of Nuna, suggests that rock units in the Yangtze Block were spatially linked with northwestern Laurentia and possibly Siberia, whereas Cathaysia was joined to northern India. During the formation of Rodinia at the end of the Mesoproterozoic through to that of Pangea in the mid-Paleozoic, Cathaysia remained joined to northern India. Early Neoproterozoic supra-subduction zone magmatic arc-back arc assemblages ranging in age from ~1000Ma to 810Ma occur within Cathaysia, along its northwestern margin, and along the southeastern margin of the Yangtze Block. These rocks provide a record of convergent plate interaction, which continued along the western margin of the Yangtze Block until around 700Ma and correlates with similar along strike subduction zone magmatism in northwest India, Seychelles and Madagascar. During the final assembly of Gondwana in the early Paleozoic suturing of India-South China with the Western Australia-Mawson blocks along the Kuunga Orogen resulted in the accretion of the Sanya Block of Hainan Island with the rest of Cathaysia. The accretion of Laurussia to Gondwana in the mid-Paleozoic to form Pangea corresponds with the initiation of lithospheric extension along the northern margin of Gondwana and the separation of a number of continental blocks, including South China, which then drifted northward across the Paleo-Tethys to collide with the Asian segment of Pangea in the Permo-Triassic.
For the first time, U-Net is adopted to detect the concrete cracks in the present study. Focal loss function is selected as the evaluation function, and the Adam algorithm is applied for ...optimization. The trained U-Net is able of identifying the crack locations from the input raw images under various conditions (such as illumination, messy background, width of cracks, etc.) with high effectiveness and robustness. In addition, U-Net based concrete crack detection method proposed in the present study is compared with the DCNN-based method, and U-Net is found to be more elegant than DCNN with more robustness, more effectiveness and more accurate detection. Furthermore, by examining the fundamental parameters representing the performance of the method, the present U-Net is found to reach higher accuracy with smaller training set than the previous FCNs.
•Concrete crack detection method using U-Net is proposed.•U-Net is of more robustness and more effectiveness than CNN-based method.•Only 57 images in the training and validation set can provide a good model for detecting the cracks.•Precisions of the model trained by 57 images can reach 0.9 for different complex situations.•U-Net can reach higher accuracy with smaller training set than the previous FCNs.
Dendritic cell-associated C-type lectin-1 (Dectin-1) receptor has been reported to be involved in neuroinflammation in Alzheimer's disease and traumatic brain injury. The present study was designed ...to investigate the role of Dectin-1 and its downstream target spleen tyrosine kinase (Syk) in early brain injury after ischemic stroke using a focal cortex ischemic stroke model.
Adult male C57BL/6 J mice were subjected to a cerebral focal ischemia model of ischemic stroke. The neurological score, adhesive removal test, and foot-fault test were evaluated on days 1, 3, 5, and 7 after ischemic stroke. Dectin-1, Syk, phosphorylated (p)-Syk, tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase (iNOS) expression was analyzed via western blotting in ischemic brain tissue after ischemic stroke and in BV2 microglial cells subjected to oxygen-glucose deprivation/reoxygenation (OGD/R) injury in vitro. The brain infarct volume and Iba1-positive cells were evaluated using Nissl's and immunofluorescence staining, respectively. The Dectin-1 antagonist laminarin (LAM) and a selective inhibitor of Syk phosphorylation (piceatannol; PIC) were used for the intervention.
Dectin-1, Syk, and p-Syk expression was significantly enhanced on days 3, 5, and 7 and peaked on day 3 after ischemic stroke. The Dectin-1 antagonist LAM or Syk inhibitor PIC decreased the number of Iba1-positive cells and TNF-α and iNOS expression, decreased the brain infarct volume, and improved neurological functions on day 3 after ischemic stroke. In addition, the in vitro data revealed that Dectin-1, Syk, and p-Syk expression was increased following the 3-h OGD and 0, 3, and 6 h of reperfusion in BV2 microglial cells. LAM and PIC also decreased TNF-α and iNOS expression 3 h after OGD/R induction.
Dectin-1/Syk signaling plays a crucial role in inflammatory activation after ischemic stroke, and further investigation of Dectin-1/Syk signaling in stroke is warranted.
Abstract Whole tumor cell lysates (TCL) have been implemented as tumor antigens for cancer vaccine development, although clinical outcomes of TCL-based antitumor immunotherapy remain unsatisfactory. ...In order to improve the efficacy of TCL-based vaccines, biomaterials have been employed to enhance antigen delivery and presentation. Here, we have developed chitosan nanoparticles (CTS NPs) with surface mannose (Man) moieties for specific dendritic cells (DCs) targeting (Man-CTS NPs). The Man-CTS NPs were then loaded with TCL generated from B16 melanoma cells (Man-CTS-TCL NPs) for in vitro and in vivo assessment. Potency of the Man-CTS-TCL NPs as cancer vaccine was also assessed in vivo by immunization of mice with Man-CTS-TCL NPs followed by re-challenge with B16 melanoma cell inoculation. We have shown here that Man-CTS-TCL NPs promote bone marrow-derived dendritic cells (BMDCs) maturation and antigen presentation in vitro. In vivo evaluation further demonstrated that the Man-CTS-TCL NPs were readily taken up by endogenous DCs within the draining lymph node (DLN) following subcutaneous administration accompanied by increase in serum IFN-γ and IL-4 levels. Tumor growth was also significantly delayed in mice primed with Man-CTS-TCL NPs vaccine, attributable at least in part to cytotoxic T lymphocytes response. Moreover, Man-CTS-TCL NPs vaccine also exhibited therapeutic effects in mice with melanoma. Thus, we report here the Man-CTS-TCL NPs as effective anti-tumor vaccine for cancer immunotherapy.
This research aimed to investigate the expression level of Extracellular matrix metalloproteinase inducer (EMMPRIN) in peripheral blood and matrix metalloproteinases (MMPs) in the serum of patients ...with acute coronary syndrome, and to clarify the relationship between them, so as to analyze the pathogenesis of the coronary syndrome. For this purpose, 232 patients (patient group) with the acute coronary syndrome (ACS) diagnosed in the cardiology department of our hospital from May 2020 to March 2021 were collected, and the coronary angiography results of 76 healthy people (healthy group) were collected at the same time, and the index differences between the two groups were compared. First, compare the EMMPRIN expression level of the two groups of subjects, including EMMPRIN on the surface of platelets and monocytes. Second, analyze the difference in MMPs expression level between the two groups, and compare the difference of EMMPRIN and MMPs expression levels in different types of patients according to the disease type. Finally, correlation analysis was used to evaluate the correlation between EMMPRIN and MMPs expression levels in patients, and the ability of mutual regulation between them was analyzed. Results showed that The expression levels of EMMPRIN and MMPs in patients were significantly different from those in healthy patients (P<0.05), and the expression levels of EMMPRIN and MMPs in different types of patients were significantly different (P<0.05). The distribution of coronary plaque in different types of patients was significantly different, and the expression levels of EMMPRIN and MMPs in patients with a different coronary plaque were significantly different (P<0.05). There was a positive correlation between EMMPRIN on the platelet surface and MMPs expression in serum, and a positive correlation between EMMPRIN on the monocyte surface and MMPs expression in serum. In conclusion, the peripheral blood EMMPRIN and serum MMPs in patients with acute coronary syndrome were significantly higher than those in healthy people, and the expression of EMMPRIN in patients with the acute coronary syndrome was positively correlated with serum MMPs.
Multipartite entangled states are crucial for numerous applications in quantum information science. However, the generation and verification of multipartite entanglement on fully controllable and ...scalable quantum platforms remains an outstanding challenge. We report the deterministic generation of an 18-qubit Greenberger-Horne-Zeilinger (GHZ) state and multicomponent atomic Schrödinger cat states of up to 20 qubits on a quantum processor, which features 20 superconducting qubits, also referred to as artificial atoms, interconnected by a bus resonator. By engineering a one-axis twisting Hamiltonian, the system of qubits, once initialized, coherently evolves to multicomponent atomic Schrödinger cat states-that is, superpositions of atomic coherent states including the GHZ state-at specific time intervals as expected. Our approach on a solid-state platform should not only stimulate interest in exploring the fundamental physics of quantum many-body systems, but also enable the development of applications in practical quantum metrology and quantum information processing.
The multicultural characteristics of students belonging to ethnic minorities in China pose challenges for teachers. Teacher competence in dealing with culturally diverse students has been extensively ...discussed in international scholarship and referenced by Chinese researchers, but there is limited empirical research on how teacher education programmes in China respond to this challenge and theoretical discussions. Based on content analysis on teacher education programmes and syllabuses, as well as expert interviews with four teacher educators at two teacher education institutions, this study investigates how the cultivation of multicultural competence is incorporated into teacher education programmes, and the external forces that shape it. Drawing on international scholarship on teachers' multicultural competence and Cochran-Smith's framework on external forces influencing multicultural teacher education practices, I argue that the cultivation of teachers' multicultural competence for their future work in ethnic minority education is, to a great extent, missing from teacher education programmes. Furthermore, what pre-service teachers' competence covers, and the external forces that influence how teacher education plays out in practice, are influenced and somewhat determined by the large social, economic and political context as well as the agenda for educational reform in China.
Dynamic relaxation is an intrinsic and universal feature of glasses and enables fluctuation and dissipation to occur, which induces plentiful behaviour, maintains equilibrium, and achieves evolution ...in glass systems. Relaxation covers a broad time, frequency, and temperature ranges and determines the functions, behaviour, properties and applications of glassy system. Investigations of dynamic relaxation are significant for understanding the nature of glasses, liquids, and the critical issues of glass formation and transition, dynamic and structural heterogeneities, flow behaviour and flow units, various crossover temperatures, deformations, aging and rejuvenation, stability, crystallization, and the mechanical and physical properties of glasses. Metallic glasses (MGs) with unique microstructure and mechanical and functional properties, offer a simple but effective system for study of relaxation and related issues in glass science. In this review, a panoramic view of the state of the art of various aspects of dynamic relaxation in metallic glassy system, as well as a comparison with other glassy systems, is presented. The features and mechanisms of each known relaxation mode including primary α-relaxation, slow and fast 7 -relaxations, nearly constant loss, and boson peak, as well as their coupling in MGs, are reviewed and summarized. Emphasis is presented to the microstructural origin of these dynamic relaxation modes and their connection with the dynamic and structural heterogeneities in MGs. The factors which determine and affect the relaxation modes and behaviour in low-dimensional MGs are also introduced. It is shown that the relaxation in MGs is connected with their structural characteristics, heterogeneity, formation, glass transition, flow behaviour, physical and mechanical properties, crystallization, stability, and the localized atomic diffusion. The roles and the importance of dynamic relaxation in understanding many crucial issues in glassy physics are demonstrated. The correlations between dynamic relaxation and various properties of MGs are established and summarized. With this review on dynamic relaxation in metallic glasses, relaxation in MG can provide an effective perspective for understanding nearly all issues in metallic glasses. It is demonstrated that the relationship of relaxation to various properties, similar to the relationship of structure–property of crystalline materials, can be applied to control and design of new glassy materials with multiple functionalities, superior mechanical performance, and other extraordinary physical and chemical properties. Finally, the key unsolved questions regarding dynamic relaxation in metallic glasses are listed, and several emerging research directions in this still-evolving field are highlighted for future investigations.
Although flexible and multifunctional textiles are promising for wearable electronics and portable device applications, the main issue is to endow textiles with multifunctionalities while maintaining ...their innate flexible and porous features. Herein, a vacuum‐assisted layer‐by‐layer assembly technique is demonstrated to conformally deposit electrically conductive substances on textiles for developing multifunctional and flexible textiles with superb electromagnetic interference (EMI) shielding performances, superhydrophobicity, and highly sensitive humidity response. The formed leaf‐like nanostructure is composed of silver nanowires (AgNWs) as the highly conductive skeleton (vein) and transition metal carbide/carbonitride (MXene) nanosheets as the lamina. The presence of MXene protects AgNWs from oxidation and enhances the combination of AgNWs with the fabric substrate, and the transformation of its functional groups leads to self‐derived hydrophobicity. The flexible and multifunctional textile exhibits a low sheet resistance of 0.8 Ω sq−1, outstanding EMI shielding efficiency of 54 dB in the X‐band at a small thickness of 120 µm, and highly sensitive humidity responses, while retaining its satisfactory porosity and permeability. The self‐derived hydrophobicity with a large contact angle of >140° is achieved by aging the hydrophilic MXene coated silk. The wearable multifunctional textiles are highly promising for applications in intelligent garments, humidity sensors, actuators, and EMI shielding.
A biomimetic leaf‐like nanostructure composed of a 1D AgNWs skeleton (vein) and 2D MXene as the lamina is fabricated via vacuum‐assisted layer‐by‐layer assembly for electromagnetic interference (EMI) shielding, humidity monitoring, and self‐derived hydrophobicity. The (MA1)10 silk presents an exceptional EMI shielding effectiveness of ≈90 dB at 12.4 GHz at a thickness of 480 µm, and the MXene‐coated textile induces a hydrophilic‐to‐hydrophobic transition, generating a large contact angle of >140°.
A pandemic of severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) infection broke out all over the world; however, epidemiological data and viral shedding in pediatric patients are limited. ...We conducted a retrospective, multicenter study, and followed‐up with all children from the families with SARS‐CoV‐2 infected members in Zhejiang Province, China. All infections were confirmed by testing the SARS‐CoV‐2 RNA with real‐time reverse transcription PCR method, and epidemiological data between children and adults in the same families were compared. Effect of antiviral therapy was evaluated observationally and fecal‐viral excretion times among groups with different antiviral regiments were compared with Kaplan‐Meier plot. By 29 February 2020, 1298 cases from 883 families were confirmed with SARS‐CoV‐2 infection and 314 of which were families with children. Incidence of infection in child close contacts was significantly lower than that in adult contacts (13.2% vs 21.2%). The mean age of 43 pediatric cases was 8.2 years and mean incubation period was 9.1 days. Forty (93.0%) were family clustering. Thirty‐three children had coronavirus disease 2019 (20 pneumonia) with mild symptoms and 10 were asymptomatic. Fecal SARS‐CoV‐2 RNA detection was positive in 91.4% (32/35) cases and some children had viral excretion time over 70 days. Viral clearance time was not different among the groups treated with different antiviral regiments. No subsequent infection was observed in family contacts of fecal‐viral‐excreting children. Children have lower susceptibility of SARS‐CoV‐2 infection, longer incubation, and fecal‐viral excretion time. Positive results of fecal SARS‐CoV‐2 RNA detection were not used as indication for hospitalization or quarantine.
Highlights
Children had lower susceptibility for SARS‐CoV‐2 infection than adults.
Children had longer incubation period and fecal viral excretion time after infected by SARS‐CoV‐2.
Viral clearance time was not different among the groups treated with different antiviral regiments.
Children had milder clinical symptoms, better clinical outcome, and more common fecal viral excretion.
Positive results of fecal SARS‐CoV‐2 RNA detection are not used as indication for hospitalization or quarantine.
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