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Deep convolutional neural networks often perform poorly when faced with datasets that suffer from quantity imbalances and classification difficulties. Despite advances in the field, existing two-stage approaches still exhibit dataset bias or domain shift. To counter this, a phased progressive learning schedule has been proposed that gradually shifts the emphasis from representation learning to training the upper classifier. This approach is particularly beneficial for datasets with larger imbalances or fewer samples. Another new method a coupling-regulation-imbalance loss function is proposed, which combines three parts: a correction term, focal loss, and LDAM loss. This loss is effective in addressing quantity imbalances and outliers, while regulating the focus of attention on samples with varying classification difficulties. These approaches have yielded satisfactory results on several benchmark datasets, including Imbalanced CIFAR10, Imbalanced CIFAR100, ImageNet-LT, and iNaturalist 2018, and can be easily generalized to other imbalanced classification models. Deep convolutional neural networks often perform poorly when faced with datasets that suffer from quantity imbalances and classification difficulties. Despite advances in the field, existing two-stage approaches still exhibit dataset bias or domain shift. To counter this, a phased progressive learning schedule has been proposed that gradually shifts the emphasis from representation learning to training the upper classifier. This approach is particularly beneficial for datasets with larger imbalances or fewer samples. Another new method a coupling-regulation-imbalance loss function is proposed, which combines three parts: a correction term, focal loss, and LDAM loss. This loss is effective in addressing quantity imbalances and outliers, while regulating the focus of attention on samples with varying classification difficulties. These approaches have yielded satisfactory results on several benchmark datasets, including Imbalanced CIFAR10, Imbalanced CIFAR100, ImageNet-LT, and iNaturalist 2018, and can be easily generalized to other imbalanced classification models. [ABSTRACT FROM AUTHOR]

Preterm labor, a condition associated with various risk factors such as a history of prior preterm birth (PTB) and multiple pregnancies, has recently seen an increasing focus on its potential link with dyslipidemia. This study aims to investigate the relationship between dyslipidemia in expectant mothers and the risks of PTB. We studied 6963 mothers who gave birth at the International Peace Maternal and Child Health Hospital of Shanghai Jiaotong University School of Medicine in 2020, among which, 437 women had PTB. We extracted clinical and lipid data from electronic records, using multivariable logistic regression and restricted cubic spline models to explore the link between lipid concentrations (by quartiles) in pregnancy stages and PTB risk. The PTB rate was 6.3%. Early pregnancy in the PTB group showed elevated ApoA, ApoB, CHOL, LDL, and TG levels compared to controls (all P < 0.05). Late pregnancy showed no notable lipid differences. Multivariable analysis revealed elevated ApoA, TG, higher age, BMI ≥ 28 kg/m2, hypertension, assisted reproductive technology and gestational diabetes as PTB risk factors (all P < 0.05). After adjustments, higher ApoA, ApoB, CHOL and TG levels correlated with increased PTB risk. Using the lowest quartile, the adjusted ORs for early pregnancy's highest quartile of ApoA, ApoB, CHOL and TG were 1.348, 1.442, 1.442 and 2.156, respectively. Our findings indicate that dyslipemia in early pregnancy, including elevated levels of ApoA, ApoB, CHOL and TG, are associated with PTB. Managing lipid abnormalities during pregnancy may help reduce the risk of PTB. [ABSTRACT FROM AUTHOR]

Recently, fully transformer-based trackers have achieved impressive tracking results, but this also brings a great deal of computational complexity. Some researchers have applied token pruning techniques to fully transformer-based trackers to diminish the computational complexity, but this leads to missing contextual information that is important for the regression task in the tracker. In response to the above issue, this paper proposes a token fusion method that speeds up inference while avoiding information loss and thus improving the robustness of the tracker. Specifically, the input of the transformer's encoder contains search tokens and exemplar tokens, and the search tokens are divided into tracking object tokens and background tokens according to the similarity between search tokens and exemplar tokens. The tokens with greater similarity to the exemplar tokens are identified as tracking object tokens, and those with smaller similarity to the exemplar tokens are identified as background tokens. The tracking object tokens contain the discriminative features of the tracking object, for the sake of making the tracker pay more attention to the tracking object tokens while reducing the computational effort. All the tracking object tokens are kept, and then, the background tokens are weighted and fused to form new background tokens according to the attention weight of the background tokens to prevent the loss of contextual information. The token fusion method presented in this paper not only provides efficient inference of the tracker but also makes the tracker more robust. Extensive experiments are carried out on popular tracking benchmark datasets to verify the validity of the token fusion method. [ABSTRACT FROM AUTHOR]

Nanjing Yunjin, a traditional Chinese silk weaving craft, is celebrated globally for its unique local characteristics and exquisite workmanship, forming an integral part of the world's intangible cultural heritage. However, with the advancement of information technology, the experiential knowledge of the Nanjing Yunjin production process is predominantly stored in text format. As a highly specialized and vertical domain, this information is not readily convert into usable data. Previous studies on a knowledge graph-based Nanjing Yunjin Question-Answering System have partially addressed this issue. However, knowledge graphs need to be constantly updated and rely on predefined entities and relationship types. Faced with ambiguous or complex natural language problems, knowledge graph information retrieval faces some challenges. Therefore, this study proposes a Nanjing Yunjin Question-Answering System that integrates Knowledge Graphs and Retrieval Augmented Generation techniques. In this system, the ROBERTA model is first utilized to vectorize Nanjing Yunjin textual information, delving deep into textual semantics to unveil its profound cultural connotations. Additionally, the FAISS vector database is employed for efficient storage and retrieval of Nanjing Yunjin information, achieving a deep semantic match between questions and answers. Ultimately, related retrieval results are fed into the Large Language Model for enhanced generation, aiming for more accurate text generation outcomes and improving the interpretability and logic of the Question-Answering System. This research merges technologies like text embedding, vectorized retrieval, and natural language generation, aiming to overcome the limitations of knowledge graphs-based Question-Answering System in terms of graph updating, dependency on predefined types, and semantic understanding. System implementation and testing have shown that the Nanjing Yunjin Intelligent Question-Answering System, constructed on the basis of Knowledge Graphs and Retrieval Augmented Generation, possesses a broader knowledge base that considers context, resolving issues of polysemy, vague language, and sentence ambiguity, and efficiently and accurately generates answers to natural language queries. This significantly facilitates the retrieval and utilization of Yunjin knowledge, providing a paradigm for constructing Question-Answering System for other intangible cultural heritages, and holds substantial theoretical and practical significance for the deep exploration and discovery of the knowledge structure of human intangible heritage, promoting cultural inheritance and protection. [ABSTRACT FROM AUTHOR]

In this study, the preparation of robust and transparent poly(butenyl sorbate) (PBS) membranes (PBS-R) was studied in terms of their CO2/CH4 separation performance. The organocatalytic group transfer polymerization of butenyl sorbate was used for the synthesis of PBS with a designed molecular weight and a moderate molecular weight distribution. For the first time, facile fabrication of PBS-R was achieved through thiol-ene addition between the butenyl groups of PBS and dithiols under 365-nm ultraviolet irradiation. The mechanical properties and CO2/CH4 separation performance of the PBS-R membranes were controlled by introducing an amino-triazole functional group and regulating the length and bulkiness of the dithiol spacers during thiol-ene addition. The amino and triazole groups of the PBS-R membrane showed high affinity to CO2, thereby increasing the CO2/CH4 permselectivity from 9.18 to 10.8 and the CO2 permeability from 127 to 142 barrer. The effect of tensile strength on CO2 permeability was evaluated by preparing PBS-R membranes using dithiols with two rigid benzene rings as spacers and flexible spacers. In addition, the effect of the spacer structure on the permselectivity of PBS-R was investigated using 1,4-butanedithiol, 2,2′-oxydiethanethiol, 1,8-octanedithiol, 1,4-benzenedithiol, and 4,4′-thiobisbenzenethiol. [ABSTRACT FROM AUTHOR]

Improving three-dimensional (3D) localization precision is of paramount importance for super-resolution imaging. By properly engineering the point spread function (PSF), such as utilizing Laguerre–Gaussian (LG) modes and their superposition, the ultimate limits of 3D localization precision can be enhanced. However, achieving these limits is challenging, as it often involves complicated detection strategies and practical limitations. In this work, we rigorously derive the ultimate 3D localization limits of LG modes and their superposition, specifically rotation modes, in the multi-parameter estimation framework. Our findings reveal that a significant portion of the information required for achieving 3D super-localization of LG modes can be obtained through feasible intensity detection. Moreover, the 3D ultimate precision can be achieved when the azimuthal index l is zero. To provide a proof-of-principle demonstration, we develop an iterative maximum likelihood estimation (MLE) algorithm that converges to the 3D position of a point source, considering the pixelation and detector noise. The experimental implementation exhibits an improvement of up to two-fold in lateral localization precision and up to twenty-fold in axial localization precision when using LG modes compared to Gaussian mode. We also showcase the superior axial localization capability of the rotation mode within the near-focus region, effectively overcoming the limitations encountered by single LG modes. Notably, in the presence of realistic aberration, the algorithm robustly achieves the Cramér-Rao lower bound. Our findings provide valuable insights for evaluating and optimizing the achievable 3D localization precision, which will facilitate the advancements in super-resolution microscopy. [ABSTRACT FROM AUTHOR]

Nanjing Yunjin, one of China's traditional silk weaving techniques, is renowned for its unique local characteristics and exquisite craftsmanship, and was included in the Representative List of the Intangible Cultural Heritage of Humanity by UNESCO in 2009. However, with rapid development in weaving technology, ever-changing market demands, and shifting public aesthetics, Nanjing Yunjin, as an intangible cultural heritage, faces the challenge of survival and inheritance. Addressing this issue requires efficient storage, management, and utilization of Yunjin knowledge to enhance public understanding and recognition of Yunjin culture. In this study, we have constructed an intelligent question-answering system for Nanjing Yunjin digital resources based on knowledge graph, utilizing the Neo4j graph database for efficient organization, storage, and protection of Nanjing Yunjin knowledge, thereby revealing its profound cultural connotations. Furthermore, we adopted deep learning algorithms for natural language parsing. Specifically, we adopted BERT-based intent recognition technology to categorize user queries by intent, and we employed the BERT + BiGRU + CRF model for entity recognition. By comparing with BERT + BILSTM + CRF, BERT + CRF and BILSTM + CRF models, our model demonstrated superior performance in terms of precision, recall, and F1 score, substantiating the superiority and effectiveness of this model. Finally, based on the parsed results of the question, we constructed knowledge graph query statements, executed by the Cypher language, and the processed query results were fed back to the users in natural language. Through system implementation and testing, multiple indices including system response time, stability, load condition, accuracy, and scalability were evaluated. The experimental results indicated that the Nanjing Yunjin intelligent question-answering system, built on the knowledge graph, is able to efficiently and accurately generate answers to user's natural language queries, greatly facilitating the retrieval and utilization of Yunjin knowledge. This not only reinforces the transmission, promotion, and application of Yunjin culture but also provides a paradigm for constructing other intangible cultural heritage question-answering systems based on knowledge graphs. This has substantial theoretical and practical significance for deeply exploring and uncovering the knowledge structure of human intangible heritage, promoting cultural inheritance and protection. [ABSTRACT FROM AUTHOR]

Nanjing Yunjin, one of China's traditional silk weaving techniques, is renowned for its unique local characteristics and exquisite craftsmanship, and was included in the Representative List of the Intangible Cultural Heritage of Humanity by UNESCO in 2009. However, with rapid development in weaving technology, ever-changing market demands, and shifting public aesthetics, Nanjing Yunjin, as an intangible cultural heritage, faces the challenge of survival and inheritance. Addressing this issue requires efficient storage, management, and utilization of Yunjin knowledge to enhance public understanding and recognition of Yunjin culture. In this study, we have constructed an intelligent question-answering system for Nanjing Yunjin digital resources based on knowledge graph, utilizing the Neo4j graph database for efficient organization, storage, and protection of Nanjing Yunjin knowledge, thereby revealing its profound cultural connotations. Furthermore, we adopted deep learning algorithms for natural language parsing. Specifically, we adopted BERT-based intent recognition technology to categorize user queries by intent, and we employed the BERT + BiGRU + CRF model for entity recognition. By comparing with BERT + BILSTM + CRF, BERT + CRF and BILSTM + CRF models, our model demonstrated superior performance in terms of precision, recall, and F1 score, substantiating the superiority and effectiveness of this model. Finally, based on the parsed results of the question, we constructed knowledge graph query statements, executed by the Cypher language, and the processed query results were fed back to the users in natural language. Through system implementation and testing, multiple indices including system response time, stability, load condition, accuracy, and scalability were evaluated. The experimental results indicated that the Nanjing Yunjin intelligent question-answering system, built on the knowledge graph, is able to efficiently and accurately generate answers to user's natural language queries, greatly facilitating the retrieval and utilization of Yunjin knowledge. This not only reinforces the transmission, promotion, and application of Yunjin culture but also provides a paradigm for constructing other intangible cultural heritage question-answering systems based on knowledge graphs. This has substantial theoretical and practical significance for deeply exploring and uncovering the knowledge structure of human intangible heritage, promoting cultural inheritance and protection. [ABSTRACT FROM AUTHOR]

Aim: To explore the role and mechanism of human adipose-derived mesenchymal stem cells (hAD-MSCs) in the treatment of osteoarthritis (OA). Methods: OA hulth model of Sprague Dawley (SD) rats and 20 ng/ml TNF-α treated chondrocytes were used as models of OA in vivo and in vitro, respectively. hAD-MSCs were administrated in the articular cavity by injection in vivo and co-cultured with chondrocytes using transwell in vitro. Haematoxylin and eosin staining and Safranin-O/Fast green staining were performed to detect tissue destruction and histopathology. Scanning electron microscopy and transmission electron microscopy were used to observe the ultrastructure of chondrocytes. The pyroptosis signaling pathway-related proteins were detected by immunohistochemistry, immunofluorescence, qRT-PCR and Western blot. And small interference technology was used to study the mechanism in depth. Results: hAD-MSCs could delay the development of rat OA, improve the pathological changes of joints, inhibit the expression of NLRP3, Caspase1, GSDMD and TNFR1. In vitro, the expression of pyroptosis signal proteins in chondrocytes was significantly elevated when stimulated with TNF-α, the level of inflammatory factors such as IL-1β, IL-18 was increased, and the cell morphology was significantly destroyed. While co-cultured with hAD-MSCs, these syndromes were reversed. Knockout of TNFR1 also returned the upregulation of pyroptosis signals which caused by TNF-α. Conclusion: These results demonstrated that hAD-MSCs could inhibit pyroptosis signaling pathway of chondrocytes induced by TNF-α, which have raised our understanding of the role of hAD-MSCs as promising therapy for the management of OA. [ABSTRACT FROM AUTHOR]

Purpose: To assess the development and progression of lacquer cracks/patchy atrophies (LCs/PAs) in high myopia. Methods: The case control study included highly myopic eyes (refractive error ≤ − 6.0 diopters), examined in the population-based Beijing Eye Study 2001/2011. Using fundus photographs taken in 2001 and 2011 and optical coherence tomographic images obtained in 2011, we assessed the incidence and enlargement of pre-existing LC/PAs. Results: The study included 89 highly myopic eyes (age: 65.0 ± 9.4 years). Newly developed or enlarged LC/PAs were detected in 17 (19.1%; 95% confidence interval (CI): 11.0, 27.0) eyes, with a new LC development without previous LCs, enlargement of a pre-existing LC, LC enlargement to a PA, development of a new PA without any previous LCs, and enlargement of a pre-existing PA detected in 3, 3, 5, 3, and 3 eyes, respectively. In 14 (82.4%; 95%CI: 62.3, 100) of the 17 eyes with LC/PA development or enlargement, the LC/PAs elongated perpendicularly to, and widened in, the direction of gamma zone enlargement. Higher prevalence of LC/PA enlargement was associated (multivariable analysis) with higher myopic maculopathy stage in 2001 (odds ratio (OR): 7.83; 95%CI: 2.65, 23.2; P < 0.001) and higher frequency of parapapillary delta zone enlargement (OR: 32.0; 95%CI: 3.07, 334; P < 0.001). Prevalence of LC/PA enlargement was lower than the prevalence of changes in other myopic maculopathy features (disc-fovea distance elongation: 71%; choroidal vessel shift: 55%; reduction in ophthalmoscopical disc size: 34%; ophthalmoscopic disc size enlargement: 25%). All eyes with LC/PA enlargement showed a pre-existing and enlarging gamma zone. Conclusions: Development and enlargement of LC/PAs were associated with enlargement of parapapillary delta zone and often occurred in association with the direction of gamma zone enlargement. [ABSTRACT FROM AUTHOR]

The construction of an environmentally friendly and efficient photocatalyst for water splitting and hydrogen evolution can effectively alleviate the pressure of current energy consumption and environmental pollution. Herein, by using first-principles calculations, the MoSiGeN4/SiC heterojunction was studied as a potential photocatalyst. According to different stacking methods, 12 kinds of configurations of such heterojunction with high symmetry were constructed, among which four kinds show excellent stability and hence were further studied. The results show that such heterojunction is Z-scheme heterojunction, which not only has good light absorption efficiency, but also shows excellent performance of photocatalytic water splitting for hydrogen evolution. In addition, one of the stable configurations shows better photocatalytic hydrogen evolution performance than precious metal catalyst Pt, and the Gibbs free energy is only −0.039 eV. It is expected to prepare a hydrogen evolution catalyst with excellent performance. Further, the possible mechanism responsible for the excellent properties of MoSiGeN4/SiC heterojunction in photocatalysis has been revealed. Our research further enriches the theoretical research genealogy of MA2X4 family materials and guides the direction for further rational design of photocatalysts. Schematic diagrams of all studied configurations, catalytic mechanism and HER performance characterization. [ABSTRACT FROM AUTHOR]

The study aimed to discuss the association between sleep duration and the risk of hyperhomocysteinemia (Hhcy). This cross-sectional study included 4173 adults (≥ 20 years) from the National Health and Nutrition Examination Survey 2005–2006. According to their sleep duration, participants were divided into five subgroups. Multivariate logistic regression analysis models and restrictive cubic spline regressions were used to explore the association between sleep duration and the risk of Hhcy. Compared with the participants who sleep 7 h, sleep deprivation (≤ 5 h) increased the risk of Hhcy, odds ratio (OR) 1.68 (95% confidence interval (CI) 1.06–2.68); Excessive sleep (≥ 9 h) also increased the risk of Hhcy, OR 1.86 (95% CI 1.09–3.14) after adjusting for a series of confounding factors in the entire population. The risk of Hhcy was distributed in a U-shape with sleep duration. Similar results were demonstrated in obese populations. The association between sleep duration and the risk of Hhcy is U-shaped. Both sleep deprivation and excessive sleep can increase the risk of Hhcy. [ABSTRACT FROM AUTHOR]

This document is a correction notice for an article titled "Phased progressive learning with coupling-regulation-imbalance loss for imbalanced data classification" published in the journal Neural Computing & Applications. The correction addresses an error in the primary affiliation details for one of the authors, Liang Xu. The correct affiliation should be the School of Biomedical Engineering, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, Anhui, 230026, People's Republic of China. The original article has been corrected. The publisher, Springer Nature, remains neutral regarding jurisdictional claims and institutional affiliations. [Extracted from the article]

Background and Purpose: Increased high-mobility group box 1 (HMGB1) levels were found in patients after acute ischemic stroke. The aim of this study was to examine whether the circulating HMGB1 levels could predict the 3-month post-stroke depression (PSD).Methods: The subjects were first-ever ischemic stroke patients who were hospitalized during the period from July 2020 to December 2020. HMGB1 concentrations were measured by enzyme-linked immunosorbent assay after admission. A 24-item Hamilton Depression Rating Scale was performed to evaluate PSD at 3 months after stroke.Results: The analyses included 324 participants (mean age, 63.7 years; 171 male). Ninety-four patients (29.0%) were diagnosed as having PSD at 3 months. The median serum HMGB1 levels at admission was 7.5 ng/mL (IQR, 4.4-11.3 ng/mL). The PSD distribution across the HMGB1 quartiles ranged between 17.5% (first quartile) and 57.5% (fourth quartile). After covariate adjustments, the fourth quartile of HMGB1 was found to be associated with a higher risk of PSD (as compared with first HMGB1 quartile, odd ratio, 1.26; 95% confidence interval [CI], 1.17-1.35; P < 0.001). The area under the receiver operating characteristic curve of HMGB1 was 0.726 (95% CI 0.660-0.792) for PSD. Similar results were found when HMGB1 was analyzed as continuous variable. Furthermore, the optimal cutoff point of circulating HMGB1 levels was 8.6 ng/mL, with a sensitivity of 69.2% and a specificity of 73.9%.Conclusions: This study demonstrated that higher HMGB1 levels in the acute phase of ischemic stroke were associated with increased risk of PSD. [ABSTRACT FROM AUTHOR]

We show that a Single-Atom Electrocatalyst (SAC) for the Nitrogen Reduction Reaction (NRR) can provide an environmentally green alternative to the Haber–Bosch high-temperature high-pressure process, replacing the water gas shift production of H2 with H extracted from water. Anchoring the single atom on a two-dimensional substrate provides control to tune NRR catalytic performance toward a SAC possessing high utilization, high activity, and high selectivity. Experimental results suggest that this can significantly improve the activity and selectivity of NRR, but the specific reaction mechanism remains uncertain. This makes it difficult to select new catalytic materials for further optimization. Here we use Density Functional Theory to study the NRR catalytic mechanism on a catalytic model using a MoS2 substrate to support a single atom site. We correct for solvation effects on the electrochemical reactions. We started with Fe@MoS2, for which there are promising experimental reports, and conducted a systematic study of the NRR reaction mechanisms. These results show that N2 adsorption, hydrogenation of N2, desorption of NH3, and Hydrogen Evolution are all critical steps affecting the reaction rates. Based on these steps, we scanned 23 transition metal elements to find improved catalysts. We identified Ir@MoS2 (Mo top site) as the best candidate, predicted to have good catalytic activity and selectivity with 64.11% Faraday Efficiency. These results on the mechanism for NRR and the in silico search for alternative catalysts provide new promising targets for synthesizing novel and efficient SAC@MoS2 NRR catalysts. [ABSTRACT FROM AUTHOR]

In this study, Kagome lattice structure (KLS) produced by 3D printer is used as a turbulator for a typical rectangular internal cooling channel at the trailing edge of turbine blade. The friction factor and bottom wall heat transfer coefficient of the channel filled with low thermal conductivity ABS plastic KLS are experimentally and numerically analyzed by changing the column diameter d/H = 0.1–0.2, the inclination angle α = 45°-60° and included angle β = 120°-150° under the Reynolds number range of 5000–30,000. The fitting correlations of these parameters with the channel friction factors and the average Nusselt number of working surface are obtained. The results show that when Reynolds number increases from 5000 to 30,000, the vortex range behind type II column increases obviously, the local heat transfer effect is obviously improved and the comprehensive impact factor F increases by 180%. When d/H increases from 0.1 to 0.2, the area of stagnation vortex after type I column expands, the heat transfer effect improves significantly, the friction factor increases by 60.9%, the average Nusselt number of channel wall increases by 32.2%, and the F increases by 16%. With the increase of α and β, the heat transfer effect has no obvious change, but the friction factor in the channel is reduced with different degrees. The high heat transfer area is mainly concentrated near the surface of the column. In the obtained fitting correlation, the maximum error of the average Nusselt number is 9.3%, and the maximum error of friction factor is 24%. [ABSTRACT FROM AUTHOR]

The forward calculation of gravity anomalies is a non-negligible aspect contributing to the time consumption of the entire process of basement relief estimation. In this study, we develop a fast hybrid computing scheme to compute the gravity anomaly of a basement. We use the vertical prism source equation in a given region R centered at a certain gravity observation point and the vertical line source equation outside R to derive the gravity anomaly. We observe that the computation with the vertical line source equation is much faster than that of the vertical prism source equation, but the former is slightly inaccurate. Therefore, our method is highly efficient and able to avoid the errors caused by the low accuracy of the vertical line source equation near the observation point. We then derive the general principle of choosing the size of R via a series of prism model tests. Our tests on the gravity anomaly over the Los Angeles Basin confirm the correctness of our proposed forward strategy. We modify Bott's method with an accelerating factor to expedite the inversion procedure and presume that the density contrast between the sediments and the basement in a sedimentary basin varies laterally and can be obtained using the equivalent equation. Synthetic data and real data applications in the Weihe Basin illustrate that our proposed method can accurately and efficiently estimate the basement relief of sedimentary basins. [ABSTRACT FROM AUTHOR]

2-(N-tert-butoxycarbonylamino) pyridine and 2-(N-tert-butoxycarbonylamino)-3-methylpyridine were synthesized in a one-step method using either 2-aminopyridine or 2-amino-3-methyphyridine with tert-butylcarbonyl anhydride as the starting materials. The products were characterized by single-crystal X-ray diffraction, 1H NMR, 13C NMR, and HRMS. The biological activity of the two compounds against five fungi was determined. 2-(N-tert-butoxycarbonylamino) pyridine has more than 50% inhibitory activity against Pyricularia oryzae, Colletotrichum gloeosporioides, and Alternaria alternate. In addition, the inhibitory activity of 2-(N-tert-butoxycarbonylamino)-3-methylpyridine against Alternaria alternate reached 67.69%. Two 2-BOC aminopyridine derivatives were synthesized and structurally characterized by 1H NMR, 13C NMR, HRMS analysis and X-ray crystal diffraction. The inhibitory activity both compounds was studied. [ABSTRACT FROM AUTHOR]

Design optimization of beam structures is a significant topic as beams are an efficient load-carrying component in engineering applications. Most of the earlier researches concentrate on the structural optimization of beams with invariant cross-section topology, and design optimization of periodic beam structures, which cross-section topology varies along the axial direction, has not been extensively investigated. This work presents a novel approach based on the relaxed Saint-Venant solution to conduct microstructural topology optimization of periodic beam structures for minimum structural compliance. One benefit of adopting Saint-Venant solution based compliance formulation is that the strain energy induced by transverse shear loading is incorporated in the structural compliance, which is not reflected in that based on first-order homogenization of the asymptotic homogenization (AH) theory, so that a more reasonable objective function is adopted for the optimization problem. In addition, a material connectivity constraint, which is constructed by restraining the ratio of the strain energy calculated from relaxed Saint-Venant solution to that obtained from first-order homogenization of the AH theory, is further proposed to prevent material separation or to strengthen material connection through the thickness direction. The detailed sensitivity analysis of the objective function and the constraints are carried out with the adjoint method, and several numerical examples are given to show the validity of the relaxed Saint-Venant solution based compliance formulation and the effectiveness of the proposed material connectivity constraint. [ABSTRACT FROM AUTHOR]

Nonlinear bending analysis was performed of magnetoelectroelastic (MEE) composite plates under a mechanical and magnetoelectric (ME) load by using von Karman's nonlinear geometric equation and the higher order shear deformation theory (HSDT). Nonlinear higher order partial differential equations for MEE plates were derived by using Hamiltonian equilibrium equation. The MEE plate is considered to have clamped boundary condition. The nonlinear high-order equations can turn into algebraic equations through Galerkin method. Then the effects of scale effect of MEE plate (for instance, the aspect ratio) and external load (for instance, mechanical) on the displacement of the considered MEE plate were investigated. [ABSTRACT FROM AUTHOR]

In order to improve the search performance of rich text content, a cloud search engine system based on rich text content is designed. On the basis of traditional search engine hardware system, several hardware devices such as Solr index server, collector, Chinese word segmentation device and searcher are installed, and the data interface is adjusted. On the basis of hardware equipment and database support, this paper uses the open source Apache Tika framework to obtain the metadata of rich text documents, implements word segmentation according to the rich text content and semantics, and calculates the weight of each keyword. Input search keywords, establish a text index, use BM25 algorithm to calculate the similarity between keywords and text, and output the search results of rich text according to the similarity calculation results. The experimental results show that the design system has high recall rate, high throughput, and the construction time of each data item index in different files is short, which improves the search efficiency and search accuracy. [ABSTRACT FROM AUTHOR]

Cytochrome P450 2J2 (CYP2J2) is responsible for the epoxidation of endogenous arachidonic acid, and is involved in the metabolism of exogenous drugs. To date, no crystal structure of CYP2J2 is available, and the proposed structural basis for the substrate recognition and specificity in CYP2J2 varies with the structural models developed using different computational protocols. In this study, we developed a new structural model of CYP2J2, and explored its sensitivity to substrate binding by molecular dynamics simulations of the interactions with chemically similar fluorescent probes. Our results showed that the induced-fit binding of these probes led to the preferred active poses ready for the catalysis by CYP2J2. Divergent conformational dynamics of CYP2J2 due to the binding of each probe were observed. However, a stable hydrophobic clamp composed of residues I127, F310, A311, V380, and I487 was identified to restrict any substrate access to the active site of CYP2J2. Molecular docking of a series of compounds including amiodarone, astemizole, danazol, ebastine, ketoconazole, terfenadine, terfenadone, and arachidonic acid to CYP2J2 confirmed the role of those residues in determining substrate binding and specificity of CYP2J2. In addition to the flexibility of CYP2J2, the present work also identified other factors such as electrostatic potential in the vicinity of the active site, and substrate strain energy and property that have implications for the interpretation of CYP2J2 metabolism. [ABSTRACT FROM AUTHOR]

Background: Rice amylose content and amylopectin structure corporately determine rice eating and cooking qualities (ECQs). Soluble starch synthase (SS) IV-2 is a member of the soluble starch synthesis gene family but with unknown effects on ECQs. Results: In this study, three populations derived from a cross of two parents who possess the same major genes of starch bio-synthesis were employed to investigate the influence of SSIV-2 and its combined effects with ADPglucose pyrophorylase large unit (AGPlar) and Pullulanase (PUL) on ECQs. The results illustrated that the polymorphism of SSIV-2 alleles significantly affected gel consistency (GC), gelatinization temperature (GT), percent of retrogradation (PR) and three crucial rapid viscosity analysis (RVA) profile parameters: peak viscosity (PKV), breakdown viscosity (BDV) and setback viscosity (SBV). And SSIV-2 allele derived from CG173R had better quality traits with lower GT, SBV and PR. Moreover, its interaction with AGPlar was responsible for the variations of GC, apparent amylose content (AAC), GT, PR and all RVA parameters except for pasting temperature (PaT) and peak time (PeT), in terms of GC, PKV and CSV, AGPlar derived from CG173R had an epistatic effect on SSIV-2; additionally, interaction of SSIV-2 and PUL mainly affected GC, AAC, PKV, CPV, CSV and SBV. I-C and C-1 (I, allele of AGPlar from Guangzhan 63S; C, allele of SSIV-2 from CG173R; 1, allele of PUL from Guangzhan 63S) combinations had better ECQs. Conclusions: SSIV-2 alleles significantly affect rice quality, especially the parameters relevant to gelatinized and thermal characteristics of starch (GC, PR, GT, PKV, BDV and SBV) under the same major genes (Waxy and SSII-3) background. It indicates that SSIV-2 functions elongation of starch chain. These findings suggest that the effects of SSIV-2 and its interaction with AGPlar and PUL are vital for rice quality breeding with the same major genes. [ABSTRACT FROM AUTHOR]

A new semi-quantum secure direct communication (SQSDC) protocol based on four-particle cluster states is designed. Different from the existing SQSDC protocols, this semi-quantum secure direct communication protocol includes two classical senders and one quantum receiver. The designed SQSDC protocol promises higher qubit efficiency than the previous SQSDC protocols by adopting the property of the four-particle cluster state to implement encoding operations. Moreover, the security of the proposed protocol under some common eavesdropping attacks is validated. Furthermore, the presented SQSDC protocol can be transformed into an efficient multi-party semi-quantum dialogue (SQD) protocol. [ABSTRACT FROM AUTHOR]

Neurodegeneration involves abnormal aggregation of intrinsically disordered amyloidogenic peptides (IDPs), usually mediated by hydrophobic protein-protein interactions. There is mounting evidence that formation of α-helical intermediates is an early event during self-assembly of amyloid-β42 (Aβ42) and α-synuclein (αS) IDPs in Alzheimer's and Parkinson's disease pathogenesis, respectively. However, the driving force behind on-pathway molecular assembly of partially folded helical monomers into helical oligomers assembly remains unknown. Here, we employ extensive molecular dynamics simulations to sample the helical conformational sub-spaces of monomeric peptides of both Aβ42 and αS. Our computed free energies, population shifts, and dynamic cross-correlation network analyses reveal a common feature of long-range intra-peptide modulation of partial helical folds of the amyloidogenic central hydrophobic domains via concerted coupling with their charged terminal tails (N-terminus of Aβ42 and C-terminus of αS). The absence of such inter-domain fluctuations in both fully helical and completely unfolded (disordered) states suggests that long-range coupling regulates the dynamicity of partially folded helices, in both Aβ42 and αS peptides. The inter-domain coupling suggests a form of intra-molecular allosteric regulation of the aggregation trigger in partially folded helical monomers. This approach could be applied to study the broad range of amyloidogenic peptides, which could provide a new path to curbing pathogenic aggregation of partially folded conformers into oligomers, by inhibition of sites far from the hydrophobic core. [ABSTRACT FROM AUTHOR]

Background: Tumor shape is strongly associated with some tumor's genomic subtypes and patient outcomes. Our purpose is to find the relationship between risk stratification and the shape of GISTs.Methods: A total of 101 patients with primary GISTs were confirmed by pathology and immunohistochemistry and underwent enhanced CT examination. All lesions' pathologic sizes were 1 to 10 cm. Points A and B were the extremities of the longest diameter (LD) of the tumor and points C and D the extremities of the small axis, which was the longest diameter perpendicular to AB. The four angles of the quadrangle ABCD were measured and each angle named by its summit (A, B, C, D). For regular lesions, we took angles A and B as big angle (BiA) and small angle (SmA). For irregular lesions, we compared A/B ratio and D/C ratio and selected the larger ratio for analysis. The chi-square test, t test, ROC analysis, and hierarchical or binary logistic regression analysis were used to analyze the data.Results: The BiA/SmA ratio was an independent predictor for risk level of GISTs (p = 0.019). With threshold of BiA at 90.5°, BiA/SmA ratio at 1.35 and LD at 6.15 cm, the sensitivities for high-risk GISTs were 82.4%, 85.3%, and 83.8%, respectively; the specificities were 87.1%, 71%, and 77.4%, respectively; and the AUCs were 0.852, 0.818, and 0.844, respectively. LD could not effectively distinguish between intermediate-risk and high-risk GISTs, but BiA could (p < 0.05). Shape and Ki-67 were independent predictors of the mitotic value (p = 0.036 and p < 0.001, respectively), and the accuracy was 87.8%.Conclusions: Quantifying tumor shape has better predictive efficacy than LD in predicting the risk level and mitotic value of GISTs, especially for high-risk grading and mitotic value > 5/50HPF.Key Points: • The BiA/SmA ratio was an independent predictor affecting the risk level of GISTs. LD could not effectively distinguish between intermediate-risk and high-risk GISTs, but BiA could. • Shape and Ki-67 were independent predictors of the mitotic value. • The method for quantifying the tumor shape has better predictive efficacy than LD in predicting the risk level and mitotic value of GISTs. [ABSTRACT FROM AUTHOR]

Triple-negative breast cancer (TNBC) has a more aggressive phenotype and higher metastasis and recurrence rates than other breast cancer subtypes. TNBC currently lacks a transplantation model that is suitable for clinical simulations of the tumor microenvironment. Intraductal injection of tumor cells into the mammary duct could mimic the occurrence and development of breast cancer. Herein, we injected 4T1 cells into the mammary ducts of BALB/C mice to build a preclinical model of TNBC and optimized the related construction method to observe the occurrence and spontaneous metastasis of tumors. We compared the effects of different cell numbers on tumorigenesis rates, times to tumorigenesis, and metastases to determine the optimal number of cells for modelling. We demonstrated that 4T1-MIND model mice injected with 20,000 cells revealed a suitable tumor formation rate and time, thus indicating a potential treatment time window after distant metastasis. We also injected 20,000 cells directly into the breast fat pad or breast duct for parallel comparison. The results still showed that the 4T1-MIND model provides sufficient treatment time for lung metastases in mice and that it is a more reliable model for early tumor development. The 4T1-MIND model requires continuous improvement and optimization. A suitable and optimized model for translational research and studies on the microenvironment in TNBC should be developed. [ABSTRACT FROM AUTHOR]

In the present paper, the existence of nontrivial solutions of impulsive fractional differential equations with Dirichlet boundary conditions is studied. We apply Morse theory coupled with local linking arguments to solve the topic, and we prove the existence of at least one nontrivial solution for the impulsive fractional differential equations. [ABSTRACT FROM AUTHOR]

Polycyclic tetramate macrolactams (PTMs) are a widely distributed class of structurally complex natural products, and most of them exhibit multiple biological activities. However, the transcriptional regulators (TRs) involved in the regulation of PTM production have seldom been reported. Here, we identified three TRs, i.e., Sxim_22880, CvnABCSx, and WblASx, and revealed their positive roles in the regulation of PTM biosynthesis in mangrove-derived Streptomyces xiamenensis 318. This strain produces a considerable amount of PTMs at 30 °C, but the production of PTMs is mostly blocked at 37 °C. Quantitative real-time PCR analysis confirmed that the transcriptions of PTM biosynthetic genes were downregulated. We determined that the transcriptions of several putative TRs, i.e., WblASx, Sxim_22880, and CvnCSx, were significantly downregulated under such heat-shock conditions. We showed that the transcription of PTM biosynthetic genes and the production of PTMs could be restored at 37 °C if the impaired transcriptions of wblASx, sxim_22880, and cvnABCSx were restored. Electrophoretic mobility shift assays showed that none of these TRs could bind to the promoter region of the PTM gene cluster, suggesting their indirect but positive involvement in the regulation on PTM production. Moreover, concurrent overexpression of the three TRs in S. xiamenensis 318 resulted in a 242.5% increase in PTM production when the strain was cultured at 30 °C. Furthermore, overexpression of these three TRs in Streptomyces sp. FR-008 and S. albus J1074 stimulated the production of new secondary metabolites, indicating that these conserved TRs could be used to activate cryptic secondary metabolite gene clusters in Streptomyces. [ABSTRACT FROM AUTHOR]

To improve the camouflage effectiveness of pattern painting, based on gradual coloration, a new disruptive pattern painting is put forward. There are different varieties of background vegetation and physiognomy in natural, especially in coloration. Therefore, the coloration in pattern painting should be various and gradual change between different colors. The natural gradual changing coloration scheme has the best camouflage effectiveness in theory, which cannot be painted in the surface of some targets. Different coloration schemes are intelligently designed to improve pattern background matching effectiveness, and also be convenient in construction. A test pattern painting is designed based on different coloration schemes. The results show that the proposed scheme can be used to improve background matching effectiveness, and the proper coloration scheme is selected. [ABSTRACT FROM AUTHOR]

Ligand fishing is a widely used approach for screening active compounds from natural products. Recently, cell membrane (CM) as affinity ligand has been applied in ligand fishing, including cell membrane chromatography (CMC) and CM-coated magnetic bead. However, these methods possess many weaknesses, including complicated preparation processes and time-consuming operation. In this study, cheap and easily available cellulose filter paper (CFP) was selected as carrier of CM and used to fabricate a novel CM-coated CFP (CMCFP) for the first time. The type of CFP was optimized according to the amount of immobilized protein, and the immobilization of CM onto CFP by the insertion and self-fusion process was verified by confocal imaging. The CMCFP exhibited good selectivity and stability and was used for fishing potentially active compounds from extracts of Angelica dahurica. Three potentially active compounds, including bergapten, pabulenol, and imperatorin, were fished out and identified. The traditional Chinese medicine systems pharmacology database and analysis platform was used to build an active compound-target protein network, and accordingly, the gamma-aminobutyric acid receptor subunit alpha-1 (GABRA1) was deduced as potential target of CM for the active compounds of Angelica dahurica. Molecular docking was performed to evaluate the interaction between active compounds and GABRA1, and bergapten was speculated as a new potentially active compound. Compared with other methods, the fishing assay based on CMCFP was more effective, simpler, and cheaper. [ABSTRACT FROM AUTHOR]

A gearbox is part of the transmission chain of wind turbine, which can increase rotational speed and reduce torque. Dynamic characteristics of the gearbox directly influence the vibration and the service life of the wind turbine system. In this paper, dynamic behaviors of a megawatt level wind turbine gearbox are studied theoretically and experimentally by dividing the gearbox into a transmission sub-system and a body sub-system. The transmission sub-system, i.e., the gear-shaft-bearing sub-system, is coupled with the gearbox body using bearings which are simulated as mass-less springs. The theoretical study applies a finite element model for the gearbox, where the internal excitations are caused by time-varying stiffness, transmission errors and mesh impacts. The time-varying wind load is considered as the external excitation, collected by a remote real-time online test and transformed into load spectrums through the rain-flow counting method. With boundary conditions and working conditions being defined in the finite element model, the natural characteristic analysis and the dynamic response analysis are conducted. Results show that the operating frequencies of the gearbox are far away from the main natural frequencies of the system, thus avoiding resonances. The main vibration components of the gearbox are with meshing frequencies of the second and third gear stage and their multiplication counterparts. Moreover, the greatest vibration occurs at the bearing housing of the high-speed shaft with the root-mean-square value of its vibration speed less than 3.5 mm/s. A test rig is developed and the experimental vibration conditions are monitored by acceleration sensors. The experimental results are in accordance well with the theoretical results. In this way, the theoretical model is validated. The methodology reported in this paper can provide valuable guidance for practical industrial engineers. [ABSTRACT FROM AUTHOR]

The counter-gravity casting methods have been developed to remove the casting defects of Mg based alloys. However, the effects of different counter-gravity casting methods on the microstructure and mechanical properties have not been studied in detail. ZM5 alloys were prepared by gravity casting, low-pressure casting and counter-pressure casting, respectively. The mechanical properties, microstructure and fracture morphologies were examined and compared by means of optical microscopy, scanning electron microscopy methods and tensile testing. Results show that casting defects such as gas pore, shrinkage porosity and cavity can be eliminated by counter-pressure casting. The grain size of α-Mg is decreased significantly by counterpressure casting. Moreover, the precipitated particles are more uniform and finer in the counter-pressure casting sample. As a result, the mechanical properties of the alloys are greatly improved. The tensile strength and elongation of the samples by counter-pressure casting are 285 MPa and 13.9%, respectively, which are much higher than those of the low pressure casting and gravity casting. [ABSTRACT FROM AUTHOR]

This paper studies two-scale concurrent topology optimization with multiple micro heterogeneous materials subjected to volume constraints. In previous work on concurrent two-scale optimization, either only one material with optimal microstructure is assumed or multiple micro materials are included but are distributed in prescribed geometrical domains. Here the selection of micro heterogeneous materials is based on the criterion for principal stress orientation in the macro structure. To meet this requirement, an additional constraint, called misplaced material volume constraint, is introduced to constrain the volume fraction of material that is misplaced in macro structure to be less than a small parameter ε. This constraint comprises several piecewise smooth penalty functions, each of which is a proper modification of Heaviside function. One advantage of the misplaced material volume constraint is that, without much modification to the original formulation, the optimized macro material is distributed in line with the use criterion and the material microstructures automatically converge to different optimized topologies. Three numerical examples are presented to show the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

The interaction of paeoniflorin with human serum albumin (HSA) was investigated using fluorescence, UV-vis absorption, circular dichroism (CD) spectra and molecular docking techniques under simulative physiological conditions. The results clarified that the fluorescence quenching of HSA by paeoniflorin was a static quenching process and energy transfer as a result of a newly formed complex (1:1). Paeoniflorin spontaneously bound to HSA in site I (subdomain IIA), which was primarily driven by hydrophobic forces and hydrogen bonds (ΔH° = − 9.98 kJ mol, ΔS° = 28.18 J mol K). The binding constant was calculated to be 1.909 × 10 L mol at 288 K and it decreased with the increase of the temperature. The binding distance was estimated to be 1.74 nm at 288 K, showing the occurrence of fluorescence energy transfer. The results of CD and three-dimensional fluorescence spectra showed that paeoniflorin induced the conformational changes of HSA. Meanwhile, the study of molecular docking also indicated that paeoniflorin could bind to the site I of HSA mainly by hydrophobic and hydrogen bond interactions. [ABSTRACT FROM AUTHOR]

Radish is an important root vegetable crop with high nutritional, economic, and medicinal value. Lignin is an important secondary metabolite possessing a great effect on plant growth and product quality. To date, lignin biosynthesis-related genes have been identified in some important plant species. However, little information on characterization of critical genes involved in plant lignin biosynthesis is available in radish. In this study, a total of 71,148 transcripts sequences were obtained from radish root, of which 66 assembled unigenes and ten candidate genes were identified to be involved in lignin monolignol biosynthesis. Full-length cDNA sequences of seven randomly selected genes were isolated and sequenced from radish root, and the assembled unigenes covered more than 80% of their corresponding cDNA sequences. Moreover, the lignin content gradually accumulated in leaf during the developmental stages, and it increased from pre-cortex to cortex splitting stage, followed by a decrease at thickening stage and then increased at mature stage in root. RT-qPCR analysis revealed that all these genes except RsF5H exhibited relatively low expression level in root at thickening stage. The expression profiles of Rs4CL5, RsCCoAOMT1, and RsCOMT genes were consistent with the changes of root lignin content, implying that these candidate genes may play important roles in lignin formation in radish root. These findings would provide valuable information for identification of lignin biosynthesis-related genes and facilitate dissection of molecular mechanism underlying lignin biosynthesis in radish and other root vegetable crops. [ABSTRACT FROM AUTHOR]

An electrochemical sensor for hydrogen peroxide (HO) has been fabricated by electrodepositing gold nanoparticles (AuNPs) on an indium tin oxide (ITO) electrode modified with cobalt and manganese-layered double hydroxides (CoMn-LDHs). Scanning electron microscopy images reveal well-dispersed AuNPs with a typical size of 12 nm on the surface of the layered double hydroxides. Electrochemical characterizations show that the introduction of the LDH support significantly enhances the voltammetric response to HO. This is underpinned by a comparative study that uses single transition metal-LDHs (CoAl-LDHs or MgMn-LDHs) as supports. The results indicate that the presence of binary transition metals in the LDH layer may result in multiple interaction and interfacial effects between AuNPs and the support. At an optimal working voltage of +0.55 V (vs. Ag/AgCl), the sensor displays a wide linear range (0.1 μM to 1.27 mM), low detection limit (0.06 μM) and high sensitivity (125.0 μA∙mM∙cm), which are characteristics superior to those of most previously reported AuNP-based composite-modified electrodes. The sensor has good reproducibility and storage stability. In our view, this sensor represents a valuable tool for advanced sensing of HO. [ABSTRACT FROM AUTHOR]

Three coordination polymers [ZnLCl]( 1), [(AgL·NO)]( 2), [CuL·2NO]( 3) (L = uniconazole) have been synthesised and structurally characterized by element analysis, infrared spectra and X-ray crystal diffraction. Complex 1 is the triclinic system, space group P-1 with a = 8.9407(10) Å, b = 13.2994(15) Å, c = 14.9242(17) Å, α = 93.8180(10)°, β = 99.0250(10)°, γ = 104.7690(10)°, V = 1684.1(3) Å. Complex 2 is the Triclinic system, space group P-1 with a = 8.997(3) Å, b = 16.941(5) Å, c = 24.113(7) Å, α = 89.182(4)°, β = 86.440(4)°, γ = 86.440(4)°, V = 3483.0(19) Å. Complex 3 is the triclinic system, space group P-1 with a = 8.7387(5) Å, b = 13.4087(8) Å, c = 15.4353(9) Å, α = 87.8870(10)°, β = 80.7150(10)°, γ = 71.3930(10)°, V = 1691.42(17) Å. In 1 and 3, Each six-coordinated Zn(II), Cu(II) ions adopts a distorted octahedral geometry. 1 and 3 was linked into a one dimensional chain by intermolecular hydrogen bonds. But in 2, each Ag(I) ion is two-coordinated in a linear mode. Althought there is many intermolecular hydrogen bonds, but the complex is zero dimensional. Graphical Abstract: Three new coordination polymers [ZnLCl]( 1), [(AgL·NO)]( 2), [CuL·2NO]( 3) (L = uniconazole) have been synthesised and structurally characterized by element analysis, infrared spectra and X-ray crystal diffraction. [ABSTRACT FROM AUTHOR]

Based on Center of Orbit Determination in Europe (CODE) global ionospheric map (GIM) data, a statistical analysis of local total electron content (TEC) anomalies before 121 low-depth ( D ≤ 100 km) strong ( M ≥ 7.0) earthquakes has been made using the sliding median differential calculation method combining with a new approach of image processing technique. The results show that significant local TEC anomalies could be observed 0-6 days before 80 earthquakes, about 66.1% out of the total. The positive anomalies occur more often than negative ones. For 26 cases, both positive and negative anomalies are observed before the shock. The pre-earthquake TEC anomalies show local time recurrence for 38 earthquakes, which occur around the same local time on different days. The local time distribution of the pre-earthquake TEC anomalies mainly concentrates between 19 and 06 LT, roughly from the sunset to sunrise. Most of the pre-earthquake TEC anomalies do not locate above the epicenter but shift to the south. The pre-earthquake TEC anomalies could be extracted near the magnetic conjugate point of the epicenter for 40 events, which is 50% out of the total 80 cases with significant local TEC anomalies. In general, the signs of the anomalies around epicenter and its conjugate point are the same, but the abnormal magnitude and lasting time are not. [ABSTRACT FROM AUTHOR]

This paper studies maximum out-of-plane buckling load design of thin bending plates for a given amount of material. Two kinds of plates are considered. One is made of periodic homogeneous porous material. Another is uniformly stiffened solid plate. The plate material, thickness, design domain of its middle plane and boundary conditions are given. The pattern of prescribed in-plane external load or displacements along the part of boundaries, which move freely, is given. Both plate topology and micro-structural topology of porous material or stiffener layout are concurrently optimized. The artificial element material densities in both macro and micro-scale are chosen as design variables. The volume preserving nonlinear density filter is applied to obtain the black-white optimum topology and comparison of its different sensitivities is made to show the reason for oscillation during optimization process in Appendix. The new numerical implementation of asymptotic homogenization method (NIAH, Cheng (Acta Mech Sinica 29(4): 550-556, 2013) and Cai (Int J Solids Struct 51(1), 284-292, 2014) is applied to homogenization of periodic plate structures and analytic sensitivity analysis of effective stiffness with respect to the topological design variables in both macro-scale and micro-scale. On basis of that, this paper implements the sensitivity analysis of out-of-plane buckling load by using commercial FEA software and enables the application of gradient-based search algorithm in optimization. Several numerical implementation details are discussed. Three numerical examples are given to show the validity of this method. [ABSTRACT FROM AUTHOR]

A new type of valveless piezoelectric micropump is presented. Synthetic jet and Coanda effect are utilized to achieve larger and bidirectional flow rate. The numerical simulation applying the velocity and pressure boundary conditions as well as the SST turbulence model were utilized to research the performance and internal flow state of the micropump. The simulation method was tested by the previous experimental data and the results matched well. The results suggest that the flow rate of the micropump is related to the Reynolds number and frequency. The entrainment flow rate of synthetic jet accounts for over 80% of the total outflow rate. The outflow rate is much larger than the volume change of the micropump chambers. There is an optimal frequency to obtain the maximum flow rate regarding the volume change of the chambers as a constant. The fluctuation of the flow rate decreases with the increase of frequency. When the frequency is higher than 25 Hz, the outflow can be continuous. Working at the Reynolds number of 1000 and optimal frequency of 50 Hz, the flow rate is 6.8 ml/min. [ABSTRACT FROM AUTHOR]

Two coordination polymers [Ag(HIMPAA)(IMPAA)] ( 1), [Cu(HIMPAA)(IMPAA)Cl] ( 2), (HIMPAA = (2 E)-3-[4-(1H-imidazol-1-ylmethyl)phenyl]acrylic acid) have been synthesised with ozagrel and structurally characterized by element analysis, infrared spectra (IR), PXRD and X-ray crystal diffraction. Complex 1 is the monoclinic system, space group P21/c with a = 10.897(3) Å, b = 6.1624(14) Å, c = 19.274(4) Å, α = 90.00°, β = 113.13°, γ = 90.00°, V = 1190.2(5) Å, Z = 2. In complex 1, the Ag(I) atom is two-coordinated in a linear mode. Intermolecular O-H···O hydrogen bonds links 1 to generate one-dimensional hydrogen bonds chain. Complex 2 is the monoclinic system, space group C2/c with a = 22.742(7) Å, b = 13.829(4) Å, c = 7.918(2) Å, α = 90.00°, β = 97.10°, γ = 90.00°, V = 2471.1(12) Å, Z = 4. In complex 2, four HIMPAA and four Cu(II) ions forms a novel 52-membered macrocycle [Cu(IMPAA)]. The 52-membered macrocycle is further briged by HIMPAA to form a two-dimensional network. Graphical Abstract: A one-dimensional coordination polymers [Ag(HIMPAA)(IMPAA)] ( 1) and a two-dimensional network [Cu(HIMPAA)(IMPAA)Cl] ( 2), (HIMPAA = (2 E)-3-[4-(1H-imidazol-1-ylmethyl)phenyl] acrylic acid) were synthesised with ozagrel and structurally characterized by element analysis, IR, PXRD and X-ray crystal diffraction. [ABSTRACT FROM AUTHOR]

Background: Mapping tropical forest structure is a critical requirement for accurate estimation of emissions and removals from land use activities. With the availability of a wide range of remote sensing imagery of vegetation characteristics from space, development of finer resolution and more accurate maps has advanced in recent years. However, the mapping accuracy relies heavily on the quality of input layers, the algorithm chosen, and the size and quality of inventory samples for calibration and validation. Results: By using airborne lidar data as the 'truth' and focusing on the mean canopy height (MCH) as a key structural parameter, we test two commonly-used non-parametric techniques of maximum entropy (ME) and random forest (RF) for developing maps over a study site in Central Gabon. Results of mapping show that both approaches have improved accuracy with more input layers in mapping canopy height at 100 m (1-ha) pixels. The bias-corrected spatial models further improve estimates for small and large trees across the tails of height distributions with a trade-off in increasing overall mean squared error that can be readily compensated by increasing the sample size. Conclusions: A significant improvement in tropical forest mapping can be achieved by weighting the number of inventory samples against the choice of image layers and the non-parametric algorithms. Without future satellite observations with better sensitivity to forest biomass, the maps based on existing data will remain slightly biased towards the mean of the distribution and under and over estimating the upper and lower tails of the distribution. [ABSTRACT FROM AUTHOR]

New green one-pot four-component reactions of thiourea, malononitrile halohydrocarbon, aldehydes and alkyl halide have been successfully developed in eco-friendly water solvent through available phase-transfer catalyst, to access high yields of 2-amino-3-cyano-4-aryl-6-sulfanepyrimidines. [ABSTRACT FROM AUTHOR]

Key message: Transcriptome-based gene expression analysis identifies many critical salt-responsive genes in radish and facilitates further dissecting the molecular mechanism underlying salt stress response. Abstract: Salt stress severely impacts plant growth and development. Radish, a moderately salt-sensitive vegetable crop, has been studied for decades towards the physiological and biochemical performances under salt stress. However, no systematic study on isolation and identification of genes involved in salt stress response has been performed in radish, and the molecular mechanism governing this process is still indistinct. Here, the RNA-Seq technique was applied to analyze the transcriptomic changes on radish roots treated with salt (200 mM NaCl) for 48 h in comparison with those cultured in normal condition. Totally 8709 differentially expressed genes (DEGs) including 3931 up- and 4778 down-regulated genes were identified. Functional annotation analysis indicated that many genes could be involved in several aspects of salt stress response including stress sensing and signal transduction, osmoregulation, ion homeostasis and ROS scavenging. The association analysis of salt-responsive genes and miRNAs exhibited that 36 miRNA-mRNA pairs had negative correlationship in expression trends. Reverse-transcription quantitative PCR (RT-qPCR) analysis revealed that the expression profiles of DEGs were in line with results from the RNA-Seq analysis. Furthermore, the putative model of DEGs and miRNA-mediated gene regulation was proposed to elucidate how radish sensed and responded to salt stress. This study represents the first comprehensive transcriptome-based gene expression profiling under salt stress in radish. The outcomes of this study could facilitate further dissecting the molecular mechanism underlying salt stress response and provide a valuable platform for further genetic improvement of salt tolerance in radish breeding programs. [ABSTRACT FROM AUTHOR]

With the rapid growth of video data from various sources, like security and transportation surveillance, there arise requirements for both online real-time analysis and offline batch processing of large-scale video data. Existing video processing systems fall short in addressing many challenges in large-scale video processing, for example performance, data storage, and fault tolerance. The emerging cloud computing and big data techniques shed lights to intelligent processing for large-scale video data. This paper proposes a general cloud-based architecture and platform that can provide a robust solution to intelligent analysis and storage for video data, which is named as BiF (Batch processing Integrated with Fast processing) architecture. We have implemented the BiF architecture using both Hadoop platform and Storm platform, which are typical offline batch processing cloud platform and online real-time processing cloud platform, respectively. The proposed architecture can handle continual surveillance video data effectively, where real-time analysis, batch processing, distributed storage and cloud services are seamlessly integrated to meet the requirements of video data processing and management. The evaluations show that the proposed approach is efficient in terms of performance, storage, and fault tolerance. [ABSTRACT FROM AUTHOR]

microRNAs (miRNAs) are a class of single-stranded endogenous non-coding RNAs that play critical roles in plant growth, development, and environmental stress responses. Temperature is one of the major physical parameters disturbing cellular homeostasis and causing leaf etiolation in plants. Previous studies have reported that several conserved and novel miRNAs were responsive to heat stress in plants. However, the characterization of miRNAs responsive to heat stress in radish remains poorly understood. To better understand miRNAs and their target genes under heat stress, two small RNA libraries were constructed from heat-treated (Heat24) and heat-untreated (CK) radish roots. Using Solexa system, totally, 26 known and 19 novel miRNAs were identified as differentially expressed under heat stress. Expression patterns of a set of heat-responsive miRNAs were validated by quantitative real-time PCR (qRT-PCR). Furthermore, 422 sliced targets for 25 known miRNAs were identified by degradome sequencing technology, and most of the identified targets are involved in multiple biological processes including transcriptional regulation and response to biotic and abiotic stresses. Moreover, some miRNAs and their corresponding targets, which are related to the accumulation of heat stress transcription factors and heat shock proteins, played important roles in thermo-tolerance in radish. These findings could enhance the understanding of molecular mechanisms underlying miRNAs and their targets in regulating plant responses to heat stress. [ABSTRACT FROM AUTHOR]

Two new dibenzocyclooctadiene lignans, named schisantherin R (3) and schisantherin S (4), and six known compounds, named kadsuralignan I, kadsuralignan J, binankadsurin A, kadsuralactone B, acetyl-binankadsurin A, and dihydroguaiaretic acid, were isolated from the chloroform fraction of the ethanol extract of Kadsura coccinea (Lem.) A. C. Sm. The structures of the compounds were elucidated by spectroscopic analysis, including MS, CD, and 1D and 2D NMR spectra. [ABSTRACT FROM AUTHOR]

This paper aimed to obtain the elastic recovery value of the machined surface of the workpiece in the milling process of titanium alloy, because it can cause strong friction between the tool flank and the workpiece surface. A new online measurement system was designed to monitor the elastic recovery behavior of Ti6Al4V alloy in dry milling based on the digital image correlation (DIC). DIC measurement principle was intuitively analyzed by means of picture illustration. The orthogonal milling experiments were designed with different cutting parameters and the experiment processes were designed in detail, including the installation of DIC measurement system, the speckle disposal of the measured surface and the field calibration of test instrument. The displacement curve of the target region was analyzed according to the material deformation characteristics of metal materials in the cutting process and thus the calculation method of elastic recovery value of machined surface was obtained. Besides, the optimization method of cutting parameters with the minimum elastic recovery value in titanium alloy milling was also obtained, which can be expanded to the machining measurement of other difficult -to-machine materials. [ABSTRACT FROM AUTHOR]

Subarachnoid hemorrhage refers to one kind of lethal stroke. While several studies have shown the role of matrix metalloproteinase 9 in cerebral tissues and microvasculature after subarachnoid hemorrhage the role of matrix metalloproteinase 9 in large cerebral vasculature is limited, The present study aimed at investigating the relationship between the expression and activity of matrix metalloproteinase 9 and vascular endothelial cell apoptosis in the basilar artery at early-stage post-subarachnoid hemorrhaging in rats. The expression and activity of matrix metalloproteinase 9 in the basilar artery increased at 12 h after subarachnoid hemorrhage and peaked at 24 h. Concurrently, the number of apoptotic cells in the basilar artery increased at 12 h and peaked at 24 h following subarachnoid hemorrhage. Additionally, laminin and cleaved caspase 3 reached to their lowest and highest levels at 24 h after subarachnoid hemorrhage, respectively. Our results suggested that the change in expression and activity of matrix metalloproteinase 9 paralleled that of apoptotic cells in the basilar artery following subarachnoid hemorrhage. Matrix metalloproteinase 9 may be contributing to the injury of the basilar artery after subarachnoid hemorrhage via laminin degradation. Although the underlying mechanisms need to be explored further, our study has shown a potential association of matrix metalloproteinase 9 with injury of the basilar artery and can be associated with early-stage brain injury following subarachnoid hemorrhage. [ABSTRACT FROM AUTHOR]