Search

Solid-state plasma antennas are designed based on lateral surface PIN diodes (SPiN), with advantages such as frequency dynamic reconstruction, controllable beam shape, fast reconstruction performance, low profile, and flexible adaptability. They have broad application prospects in communication systems, radar systems, wireless spectrum management, and other fields. This paper proposes a new type of solid-state plasma SPiN diode with different heterostructures. By analyzing the effects of SiGe/Si heterostructures and Ge/GaAs heterostructures on the concentration and uniformity of solid-state plasma, a SPiN diode with a solid-state plasma concentration exceeding 1020 cm–3, uniform distribution, and superior system performance is obtained. This lays the foundation for the research of high-performance reconfigurable antenna systems. [ABSTRACT FROM AUTHOR]

Carbon particles, a primary component of diesel engine emissions, cause persistent erosion in the exhaust piping system, inevitably leading to performance degradation. This erosion can result in reduced fuel economy and increased emissions. The effects of three key parameters including solid particle size, turbine U/C operating conditions and rotational speed on the erosion characteristics of the flow channels of a radial turbine for vehicle diesel engine applications and their impact on performance were investigated through numerical simulations in the study. The findings indicate that larger particle size and higher rotational speed can significantly lead to the higher erosion rate density of the volute channel and casing wall surfaces. Reducing U/C does not substantially affect the distribution of erosion rate density. Centrifugal force will play an important role in the variation of erosion distribution characteristics. Compared to U/C, the other two key parameters are sensitive factors affecting turbine performance degradation. Under the same condition for operating 5000 h, 10 μm particles cause a 7.5-fold increase in efficiency loss change rate compared to 0.5 μm particles. The efficiency loss at 140 krpm is 16 times greater than that at 40 krpm. [ABSTRACT FROM AUTHOR]

Neuropathic pain is a common pain syndrome, which seriously affects the quality of life of patients. The mechanism of neuropathic pain is complex. Peripheral tissue injury can trigger peripheral sensitization; however, what really plays a key role is the sensitization of the central nervous system. Central sensitization is a key factor in the perception of chronic pain. Central sensitization refers to the increased sensitivity of the central nervous system to pain treatment, which is related to the change of the functional connection mode of the neural network. The current study aims to reveal the basic molecular mechanisms of central sensitization, including the involvement of P2 purine X4 receptor and brain-derived neurotrophic factor. In terms of treatment, although there are drugs and physical therapy, the accuracy of targeting is limited and the efficacy needs to be further improved. Future therapeutic strategies may involve the development of new drugs designed to specifically inhibit the central sensitization process. This article focuses on the effector molecules involved in central sensitization, aiming to elucidate the pathogenesis of neuropathic pain and provide a basis for the development of more effective treatment models. [ABSTRACT FROM AUTHOR]

The Earth's rotation has been decelerating throughout its history due to tidal dissipation, but the variation of the rate of this deceleration through time has not been established. We present a detailed analysis of eight geological datasets to constrain the Earth's rotational history from 650 to 240 Mya. The results allow us to test physical tidal models and point to a staircase pattern in the Earth's deceleration from 650 to 280 Mya. During this time interval, the Earth-Moon distance increased by approximately 20,000 km and the length of day increased by approximately 2.2 h. Specifically, there are two intervals with high Earth rotation deceleration, 650 to 500 Mya and 350 to 280 Mya, separated by an interval of stalled deceleration from 500 to 350 Mya. The interval with stalled deceleration is attributed mainly to reduced tidal dissipation due to the continent-ocean configuration at the time, not to changes in Earth's dynamical ellipticity from continental assembly or glaciation. Modeling indicates that, except for the very recent time, tidal dissipation is the main driver for decelerating Earth rotation. One potential implication of our findings is that the Earth's tidal dissipation, along with Earth's rotation deceleration, may play a role in the evolving Earth. [ABSTRACT FROM AUTHOR]

This paper proposes a novel cloud computingbased parallel deep reinforcement learning (DRL) energy management strategy (EMS) for connected plug-in hybrid vehicles. First, a proximal policy optimization (PPO) algorithm is developed. Since the cloud computing can reduce the computational burden of the connected vehicles, the PPO is deployed in the proposed cloud computing-based EMS. In order to improve the strategy adaptation, a parallel mechanism is proposed to achieve the information interaction with multiple vehicles. Considering the real-time control requirements, thread pool is proposed and applied in the cloud computing based parallel EMS. The thread pool-based strategy provides an efficient real-time control ability and strategy improvement solution. To verify the PPO based EMS, the dynamic programming, deep Q-network and double deep Q-network strategies are developed for comparison. It is found that the PPO can achieve similar fuel efficiency improvement with the DP strategy among the three DRL algorithms. For parallel training of multiple connected vehicles, the cloud computing-based parallel EMS improves fuel economy by approximately 7.7%. Threadpool based parallel real-time EMS reduces average time for computational interactions by 20% and further improves the fuel efficiency. The proposed strategy has the advantages of realtime control, adaptability and continuous learning for improved fuel efficiency. [ABSTRACT FROM AUTHOR]

Symbiosis between soybean and rhizobia contributes to soybean yield and quality. Although secreted rhizobial type III effectors are known to regulate infection and promote nitrogen fixation, much about them remains unknown. Mutation of NopC, a type III effector from Sinorhizobium fredii HH103, reduced nodule numbers and dry weights in 310 soybean accessions, and expression of NopC in soybean hairy roots promoted symbiosis. Based on observed differences in nodule traits between Suinong 14 and Zyd 00,006 inoculated with HH103 and the NopC mutant, 11 QTL associated with rhizobia were identified in chromosome segment substitution lines (CSSLs) derived from Suinong 14 and Zyd 00006. Using chromosome fragment insertion, whole-genome sequencing of Suinong 14 and Zyd 00006, and qRT-PCR, Glyma.19G176300 (GmCRP) was identified as a candidate gene associated with NopC, and GmCRP was found to be induced by NopC to positively regulate nodulation. SNPs located in the regulatory regions of GmCRP influenced its expression response to NopC, with SNPs contributing to nodulation having been selected during domestication. Our findings reveal the function of a soybean gene encoding a rhizobial type III effector that contributes to symbiosis, and will facilitate the practical application of symbiotic nitrogen fixation in molecular breeding. [ABSTRACT FROM AUTHOR]

Context: Transarterial embolization/chemoembolization (TAE/TACE) has been shown to be effective against ruptured hepatocellular carcinoma (HCC). However, the early clinical mortality remains unpredictable. Objectives: To conduct a comprehensive quantitative evaluation of early mortality after emergency TAE/TACE for spontaneous HCC rupture and to perform an overall analysis of risk factors to gather more representative data. Methods: The PubMed/Medline, Web of Science, and Embase databases were searched, and relevant studies were retrieved using the corresponding English keywords. Next, the literature was screened according to the inclusion and exclusion criteria. Finally, Stata version 15.1 and R Project 4.1.2 were used for meta-analysis. Results: A total of 24 studies (n = 1,083) were included in this meta-analysis. The combined 30-day mortality following emergency TAE/TACE for spontaneous HCC rupture was 28.8% (95% confidence interval (CI): 23.4 - 34.4%). After correcting for publication bias, the combined 30-day mortality rate was estimated at 28.1% (95% CI: 22.7 - 33.6%). The results of subgroup and regression analyses also revealed that preoperative liver cirrhosis and bilobar tumor distribution were significantly associated with increased 30-day mortality following TAE/TACE (P < 0.05 for all). After re-stratification of studies by publication time, it was found that the 30-day mortality after TAE/TACE treatment for spontaneous HCC rupture has decreased significantly in the past two years (P = 0.0074); the corresponding value was 19.1% (95% CI: 14.3 - 24.3%) during 2020 - 2021 and 31.6% (95% CI: 26.4 - 36.9%) during 2001 - 2010. Three independent factors, including liver cirrhosis, bilobar tumor distribution, and period of time, maybe potential factors for heterogeneity. Conclusion: In recent years, although early mortality has significantly reduced after emergency TAE/TACE for spontaneous HCC rupture, it is still not negligible. Before TAE/TACE, it is necessary for clinicians to predict the adverse outcomes, as well as the risk factors and disease-related factors, and to formulate appropriate intervention measures. [ABSTRACT FROM AUTHOR]

In this paper, model predictive control (MPC) based energy management strategy is developed for dual motor coupled plug-in hybrid vehicle (PHEV) configuration. Firstly, the dynamic characteristics and working mode of dual motor coupled PHEV configuration are analyzed. Secondly, the rule-based strategy and dynamic programming (DP) strategy are developed and selected as the benchmark. Thirdly, vehicle speed prediction accuracy of three different prediction models for various time domain lengths is investigated considering the possibility of real-time applications. Thus, RBF neural network prediction model is applied in the following MPC strategy. Finally, the MPC strategy is developed through the rolling optimization and local optimization of DP strategy, which achieves the optimal torque distribution between engine and motors. Comparative analysis for rule-based, DP and MPC strategies are performed. It is seen that the MPC strategy can obtain similar fuel consumption with DP strategy, while the MPC strategy has certain real-time application potential with only 0.269s per single step calculation time. Compared with the rule-based strategy, the MPC achieves obvious fuel consumption and total cost improvement by 14.5% and 12.6% respectively. Therefore, MPC strategy can effectively improve the fuel economy and has certain real time application potential. [ABSTRACT FROM AUTHOR]

In order to solve the problems of low joint freedom for lower limb rehabilitation exoskeleton robot and movement deviation caused by human-machine coordinated movement and based on the application of ergonomics and bionics in lower extremity rehabilitation, anthropomorphic design criterion is adopted to represent a wearable lower extremity rehabilitation exoskeleton robot with eight degrees of freedom. The mathematical model of the exoskeleton robot is established, and the forward and inverse solutions of the exoskeleton robot kinematics are obtained by the Denavit–Hartenberg (D-H) and the geometric methods. The kinematic characteristics of each joint and link of the exoskeleton robot are revealed, and the correctness of the kinematic model is verified using MATLAB. ADAMS software was used for simulation analysis, and the motion data of the lower limbs of the human body were collected by the optical motion capture system for comparison. The results show that the change laws of the hip and knee joint angles of the exoskeleton robot are basically consistent with the results of the human motion experiment, and the deviation angle is less than 5°. It is proved that the structure design of the exoskeleton robot is reasonable, and the kinematic model is established correctly, which provides an important reference to further optimize the structure of the exoskeleton robot and reducing the deviation of human-machine coordinated motion. [ABSTRACT FROM AUTHOR]

In this study, a novel neutral non-starch polysaccharide (GP1A) was extracted using hot water from ginseng roots. Chemical characteristics, monosaccharide compositions and structure of GP1A were investigated using scanning electron microscopy, gel permeation chromatography, X-ray diffraction, Fourier transform infrared spectroscopy, gas chromatography with mass spectrometer, one-dimensional and two-dimensional nuclear magnetic resonance. The results indicated that the lyophilized GP1A was a homogeneous polysaccharide with a low molecular weight of 1.03 kDa. The dominating monosaccharides of GP1A were d-glucose, d-galactose, d-mannose, d-xylose and d-arabinose. The structure analysis indicated the main chain residues sequence of GP1A was α-d-Glcp-(6→3)-α-d-Galp-(1→1)-α-d-Glcp-(3→4)-β-d-Manp-(2→2)-β-d-Arap with branch chains of α-d-Glcp substituted at α-d-Galp and β-d-Xylp substituted at β-d-Manp. [ABSTRACT FROM AUTHOR]

Triptolide (TP) exerts a promising effect in the treatment of ulcerative colitis (UC). However, its toxicity seriously hinders its application in the clinic. Previous studies indicated that dendritic cells (DCs) are the main target through which TP exerts its immunoregulatory effect. Thus, we designed an approach to target DCs in vitro to avoid the direct exposure of organs to TP. Our results revealed that DCs pretreated with TP (DCTP) exerted satisfactory therapeutic effects in mice with colitis, resulting in improved colonic inflammation and alleviated local lesion damage. In addition, no obvious toxicity was observed. DCTP also reshaped the immune milieu by decreasing CD4þ T cell numbers and increasing regulatory T cell numbers in the spleen, mesenteric lymph nodes, peripheral blood and colon; these effects were further confirmed in vitro. Downregulation of CD80/86, ICAM-1, MHCI, TLR2/4, TNF-a, and IL-6 expression and upregulation of programmed cell death ligand 1 (PDL1) and IL-10 expression were observed, indicating that DCs were converted into tolerogenic DCs. In conclusion, DCTP can effectively reduce toxicity and alleviate colonic inflammation and local lesion damage in mice with colitis. The immune mechanism underlying the effects of DCTP included the conversion of DCs into tolerogenic DCs and the alteration of T cell differentiation to produce immunoinhibitory rather than immunostimulatory T cells. [ABSTRACT FROM AUTHOR]

Based on Landsat MSS/TM/OLI (1975-2018), MODIS NDVI (2000-2015), and DMSP/OLS (1992-2013) multitemporal remote sensing data, as well as annual average precipitation and temperature data from meteorological stations (1980-2018) and SRTM DEM data, this study extracted information on climate change, human activity, and eco-environmental factors in the Zijin Mountain (ZJM) area of Shanxi Province, and then analyzed the spatiotemporal changes in ecological structure, landscape structure, and climate response. The results revealed that in the ZJM area some sustainable development indicators associated with human activity, ecology, climate, and landscape geography have changed. Specifically, over the 44-year period from 1975 to 2018, the urban and rural construction land area increased by 4.29 times; in the 22-year period from 1992 to 2013, the regional light index has increased by 26.9 times; in the past 32 years, that is, from 1987 to 2018, the average vegetation index of the entire basin increased by about 54.7%, the vegetation cover exhibited a gradual positive trend, and the land use types in the ZJM area were mainly converted from bare land to grassland or forest. Compared with 1987, the area of bare land decreased 32.5% by 2018, whereas the forest and grassland areas increased by 85.7% and 40.7%, respectively. In addition, over the 44-year period from 1975 to 2018, the road density increased by 8.57 times. The area affected by human activities, comprised roads, urban and rural construction land, and their buffer areas, accounted for 64.87% of the total study area. As a result, the fragmentation index of landscape patches has increased by 6.81 times since 1987. We conclude that in the ZJM area, the ecosystem type has transformed from an indigenous mountainous grassland to mountainous arid agriculture, and from an isolated habitat to a fragmented habitat. [ABSTRACT FROM AUTHOR]

This study discusses the effects of geometrical parameters of flaring gate piers, such as contraction ratio, sidewall extension ratio and plunge angle, on the impinging pressure and flood atomization based on hydraulic model tests and atomization simulations. It is found that the impinging pressure decreases and the length of rainstorm increases with the increasing impact collision of aerated jets. Decreasing the plunge angle and increasing the extension length of sidewall for violent collision should be considered in the design stage and protection measures for rainstorms should be taken into account. Reducing the atomization hazard by collision avoidance could be selected in the operational phase on the premise of safety factor of plunge pool. A simplified formula is developed to predict the length of rainstorm as a function of the maximum impinging pressure, for use as a reference in the design and modification of similar projects. [ABSTRACT FROM AUTHOR]

The goal of this research to realize the control humanoid type prosthetic movement used for speech recognition principles. Also, the basic principles of speaker-dependent speech recognition algorithms are introduced, a speaker-dependent speech recognition algorithm in the implementation process of an upper machine is described, and the feature template library of voice command is established. Ultimately, this information was used to test the performance of a speech recognition system. Experimental results show that this method could detect blinks at high accuracy signals and obtain an eigenvector, which achieved the goal of accurate prosthetic limb movement control. [ABSTRACT FROM AUTHOR]

[Objectives] This study was conducted to select suitable medium-sized watermelon varieties for early spring cultivation in Beijing. [Methods] Seven watermelon varieties were collected, including Beinong Tianjiao 2, Beinong Tianjiao, Hongfuji, Yongfeng 1, Beinong Futian, Beinong Shijia, and Beinong Jinxiu, and Jingxin 2 was used as the control check (CK). The growth period, morphological traits, yield traits and fruit quality of the tested varieties were investigated. [Results] Beinong Tianjiao 2 had an earlier maturation stage, a fruit development period of 38 d and a total growth period of 118 d. It showed stable growth, with a single fruit weight of 7. 56 kg, a fruit setting rate of0.99 per plant, and a yield of 83 076.9 kg/hm², which ranked, respectively, second, first, and second among all tested varieties, and were significantly superior to the CK. Furthermore, this variety had thin and tough peel, a bright red flesh color, high central sugar content, loose and crisp flesh, and a good taste. [Conclusions] It is preliminarily believed that it is suitable for early spring watermelon production in Beijing area. [ABSTRACT FROM AUTHOR]

Centennial- to millennial-scale climate variations are often attributed to solar forcing or internal climate system variability, but recognition of such variations in the deep-time paleoclimate record is extremely rare. We present an exceptionally well-preserved, millimeterscale laminated marlstone from a succession of precession-driven limestone-marlstone couplets deposited in the Western Interior Seaway (North America) immediately preceding and during the Cretaceous mid-Cenomanian event (ca. 96.5 Ma). Sedimentological, geochemical, and micropaleontological data indicate that individual pairs of light-dark laminae record alternations in the extent of water-column mixing and oxygenation. Principal component analysis of X-ray fluorescence element counts and a grayscale scan of a continuous thin section through the marlstone reveal variations with 80-100 yr, 200-230 yr, 350-500 yr, ∼1650 yr, and 4843 yr periodicities. A substantial fraction of the data indicates an anoxic bottom water variation with a pronounced 10,784 yr cycle. The centennial to millennial variations are reminiscent of those found in Holocene total solar irradiance variability, and the 10,784 yr anoxia cycle may be a manifestation of semi-precession-influenced Tethyan oxygen minimum zone waters entering the seaway. [ABSTRACT FROM AUTHOR]

Much effort has been made in investigating the seismic response and failure mechanism of rectangular subway stations, however, the influence of earth retaining systems has generally been ignored in previous studies. This paper presents a numerical study on the seismic performance of a rectangular subway station with/without earth retaining systems by taking fender piles as the example, and aims to illustrate how the existence of fender piles affects seismic responses on subway stations. The loading conditions of subway stations and their surrounding soils prior to earthquakes are discussed. Next, seismic responses of subway stations with or without fender piles were simulated. Afterward, earthquake-induced deformations of stations and surrounding soils, as well as the internal forces and damage modes of the structural components, were systematically studied. Consequently, the seismic performance of the stations was affected by the existence of fender piles. In addition, earthquake intensity is illustrated. The study showed that deformation modes of surrounding soils and damage modes of stations were different with regard to the existence of fender piles. Meanwhile, earthquake intensity influencing the seismic performance of stations with or without fender piles were found to be opposite. [ABSTRACT FROM AUTHOR]

To address the global climate crisis, achieving energy transitions is imperative. Establishing a new-type power system is a key measure to achieve CO2 emissions peaking and carbon neutrality. The core goal is to transform renewable energy resources into primary power sources. The large-scale integration of high proportions of renewable energy sources and power electronic devices will dramatically change the operational mechanisms and control strategies of power systems. Existing wind and solar converters mostly adopt the grid-following control mode, which leads to significant challenges in system security and stability as it is insufficient to support the frequency and voltage of the grid. On the other hand, gridforming control technology (GFM) can provide voltage and frequency support for the system, and thus becomes an effective measure to improve the inertia and damping characteristics of power systems. This paper illustrates the principles, control strategies, equipment types, application scenarios, and project implementation of grid-forming technology. The simulation and analysis based on a renewable-dominated real new-type power system show that GFM can significantly enhance the frequency and voltage support capacity of the power system, improve renewable energy accommodation capacity and grid transmission capacity under weak grid conditions, and play an important role in enhancing the stability and power supply reliability of renewable-dominated new-type power systems. [ABSTRACT FROM AUTHOR]

Curcumin (1,7-bis(4-hydroxy-3-methoxyphenyl)-1,6-heptadiene-3,5-dione) is a potent anticancer drug with versatile biological activities, while the clinical translation of curcumin is severely limited due to its hydrophobicity, rapid elimination, and metabolism in the blood circulation. Herein, we aim to unravel the potential of curcumin as a synergistic agent with immunotherapy in the treatment of cancers. In an effort to minimize premature release and improve the systemic bioavailability, a superior blood stable and reduction sensitive curcumin micellar formulation, of which the release can be triggered by cancer cells, is rationally designed. We have synthesized a telodendrimer (mPEG-PLA-(LA)4) capable of forming reversible disulfide crosslinked micelles (DCMs). The curcumin loaded DCMs (Cur/DCMs) are spherical with a uniform size of 24.6 nm. The in vitro release profile demonstrates that curcumin releases significantly slower from DCMs than that from non-crosslinked micelles (NCMs), while the release can be accelerated with the increasing concentration of reducing agent glutathione (GSH). Intravenous administration of Cur/DCMs stably retains curcumin in the bloodstream and efficiently improves the systemic bioavailability. Furthermore, Cur/DCMs exhibit synergistic anticancer efficacy when combined with the anti-PD-1 antibody in an MC-38 colon cancer xenograft model. Our results potentiate the integration of blood stable curcumin nanoformulation and immunotherapy for cancer treatment. [ABSTRACT FROM AUTHOR]

Effective control of fluid dynamics is of remarkable scientific and practical significance. It is hypothesized that nanoparticles could offer a novel means to control fluid dynamics. In this study, laser melting was used to investigate the feasibility of tuning fluid dynamics by nanoparticles and possibly breaking existing limits of conventional laser processing techniques. Alumina nanoparticles reinforced nickel samples, fabricated through electrocodeposition, were used for laser melting experiments. Since the melt pool surface is controlled by the fluid dynamics, surface topographies were carefully studied to reveal the nanoparticle effect on the fluid dynamics. Characterizations of surface topographies and microstructures of pure Ni and Ni/Al2O3 nanocomposite were carried out before and after laser melting. The surface roughness of the Ni/Al2O3 nanocomposite sample was reduced significantly by laser melting, which broke the existing limit of laser surface polishing of pure Ni. It is believed that the nanoparticles increased the viscosity of the molten metal, thereby enhancing the viscous damping of the capillary oscillations in the melt pool, to produce a much smoother surface. Moreover, the experimental study also revealed that the viscosity enhancement by the nanoparticles effectively suppressed the thermocapillary flows which would introduce artificial asperities on a surface. The experimental results suggest that nanoparticles are effective in controlling melt pool dynamics and overcoming the existing limits of laser processing. The new methodology, fluid dynamics control by nanoparticles, opens a new pathway to enrich liquid based processes for broad applications. [ABSTRACT FROM AUTHOR]

This work provides a novel methodology to non-destructively detect far-sided defect of sandwich structures by local defect resonance-based acoustic activation. Sandwich panel specimens with 10mm thick balsa wood core and 25mm thick Nomex honeycomb core are investigated, and artificial facesheet-core disbond with a size of 30mmx30mm is introduced to the specimens. Finite element modeling is constructed to investigate resonance frequency of defect region. Experimental apparatus is constructed to detect far-sided facesheet-core disbond defect, where vibration activation and measurement is performed at near-sided facesheet. It is shown that if the far-sided defect is activated at local defect resonance frequency, distinguishable nonlinear vibration characteristic could be observed from the near-sided facesheet, and the 3rd order superharmonic is especially significant. A stepped frequency sweep excitation approach is further developed for recognition of far-sided defect, which better fits automated defect detection process as local defect resonance frequency is not required to be preliminarily determined. [ABSTRACT FROM AUTHOR]

[Objectives] This study was conducted to screen small watermelon varieties suitable for spring greenhouses. [Methods] The field traits, yield traits, quality traits and commodity of 6 new red-flesh watermelon varieties were compared. [Results] "Jingmei 3K" and "Sumeng No. 5" had obvious advantages in quality traits, yield traits, and commodity traits. The yield reached 62 163. 3 and 63 733. 5 kg/hm², respectively; the single melon weights reached 2. 16 and 2. 21 kg, respectively; and the central sugar content reached 13. 2% and 13.1%, respectively. Meanwhile, the juice contents were high, and the taste was sweet and refreshing. They are suitable for planting under the condition of substrate cultivation technology. [Conclusions] This study provides a theoretical basis for large-area substrate cultivation and production. [ABSTRACT FROM AUTHOR]

Astronomical cycles reliably identified in the sedimentary record are useful for their paleoclimatic interpretations and construction of astrochronology. However, the depositional response and burial-diagenesis processes play a crucial role in distorting the time scales of geological records and introducing noise to orbital signals. How to evaluate the response of varied depositional environments to astronomical forcing remains a challenge. We developed the random-length average orbital power ratio calculation (RAOPR) method to evaluate average orbital power ratio distributions within a specific time interval and applied this new method to the theoretical eccentricity-tilt-precession (ETP) plus noise series and an astronomically tuned Cretaceous terrestrial stratigraphic record spanning ~24 m.y. (92-65 Ma, except for an ~3.8 m.y. gap from ca. 79.9 Ma to 76.1 Ma). Using the merged ETP plus noise series, we observed different orbital power ratio distributions for different background noise intervals. For the Cretaceous terrestrial Songliao Basin, we retrieved long-term orbital variations and used the RAOPR method to calculate the average orbital power ratios in different depositional environment intervals. Our results suggest that unusually high precession power in the Yaojia Formation resulted, in part, from autogenic processes, and unusually low precession power in the Nenjiang Formation can be attributed to marine incursion events. The eccentricity power of the meandering river facies was much higher than observed in other facies intervals. Conversely, the lowest precession power in the meandering facies may be attributed, in part, to the erosion "clipping" effect, which decreases the high-frequency precession band power and increases low-frequency eccentricity band power. [ABSTRACT FROM AUTHOR]

The article demonstrated the preclinical use of our model to test niche-cotargeting regimens, which may translate to patient-specific therapy screening and response prediction. It mentions that dissecting the chemo resistance mechanisms in B cell acute lymphoblastic leukemia bone marrow niche. It discusses the heterogeneous chemoresistance mechanisms across various B-ALL cell lines.

Programmed cell death protein-1 (PD-1) checkpoint immunotherapy efficacy remains unpredictable in glioblastoma (GBM) patients due to the genetic heterogeneity and immunosuppressive tumor microenvironments. Here, we report a microfluidics-based, patient-specific 'GBM-on-a-Chip' microphysiological system to dissect the heterogeneity of immunosuppressive tumor microenvironments and optimize anti-PD-1 immunotherapy for different GBM subtypes. Our clinical and experimental analyses demonstrated that molecularly distinct GBM subtypes have distinct epigenetic and immune signatures that may lead to different immunosuppressive mechanisms. The real-time analysis in GBM-on-a-Chip showed that mesenchymal GBM niche attracted low number of allogeneic CD154+CD8+ T-cells but abundant CD163+ tumor-associated macrophages (TAMs), and expressed elevated PD-1/PD-L1 immune checkpoints and TGF-b1, IL-10, and CSF-1 cytokines compared to proneural GBM. To enhance PD-1 inhibitor nivolumab efficacy, we co-administered a CSF-1R inhibitor BLZ945 to ablate CD163+ M2- TAMs and strengthened CD154+CD8+ T-cell functionality and GBM apoptosis on-chip. Our ex vivo patient-specific GBM-on-a-Chip provides an avenue for a personalized screening of immunotherapies for GBM patients. [ABSTRACT FROM AUTHOR]

With the increasing amount of information on the Internet, data storage management tends to be distributed. In distributed storage environment, users pay more and more attention to the timeliness of user interaction experience and the reliability of information interaction. However, the efficiency of users is often limited by the efficiency of data communication between distributed sites. One of the important goals of distributed data management is to improve the efficiency of data transmission and ensure the reliability of data transmission. Block chain technology is one of the emerging technologies supporting the development of management information system; it provides a solution for the storage, verification, transmission and communication of the distributed data. This paper focuses on solving the problem of block chain data transmission, and studies it from three aspects: improving the efficiency of data communication, ensuring the reliability of transmission, and improving the fairness of service, and different block chain data communication performance optimization strategies are proposed under the constraints of node communication capability, node trust, weight, priority of service request and other influencing factors. [ABSTRACT FROM AUTHOR]

The article presents science and engineering research on De novo rational design of a freestanding, supercharged polypeptide, proton-conducting membrane. Topics include proton translocation enables important processes in nature and man-made technologies; and controlling proton conduction and fabrication of devices exploiting biomaterials remains a challenge.

The metallurgical field, which integrates capital, raw materials and technology, contains complex engineering projects, including mining, iron making, steel making, continuous casting, rolling and metal products, in production, management, economy and technology. A lot of aspects are involved. However, limited to the current level of technological development, there are often more or less inclusions in the metallurgical process of steel, which has a great impact on the performance of the final product. Therefore, a method to reduce the inclusions generated in the metallurgical process has been innovated, which is of great significance to the existing metallurgy and its future development. Through the research of a large number of domestic and foreign related literature and existing analytical inclusion techniques, this paper uses on-site sampling, chemical analysis, metallographic analysis, scanning electron microscopy (SEM) and other methods. The distribution law and inclusion state of 1829 continuous casting slab were studied in detail. Optical microscopy is a good choice. As the name suggests, optical microscopy uses the optical system to focus and magnify the object to be measured, which is clearly displayed in the human eye. It helps us to understand the characteristics of the object from the microstructure; it can also test the appearance of the product more precisely. Therefore, to understand the distribution of non-metallic inclusions in steel and its effect on steel properties, find a control distribution method. New ways to remove tiny non-metallic inclusions are important for the production of pure steel. [ABSTRACT FROM AUTHOR]

The article focuses on progress toward measles elimination in China in 2014 and report documenting measles elimination efforts in China during 2008–2012 and a resurgence in 2013. Topics include using a measles risk assessment tool developed by the Chinese Center for Disease Control and prevention (China CDC); ensuring that school children are protected from vaccine-preventable diseases; and previous vaccination history.

Open in new tab Download slide Open in new tab Download slide OBJECTIVES Uniportal video-assisted thoracic surgery (VATS) is well accepted by surgeons for anatomical major lung resections. However, large series evaluating the results, safety and efficacy of the technique for sleeve resections are still lacking. The aim of this study was to examine our experience with the use of uniportal VATS for sleeve resections. METHODS From September 2014 to January 2018, a total of 79 consecutive patients were offered uniportal VATS sleeve resection for centrally located tumours invading the orifice of the lobar bronchus or extending into the main stem bronchus by a single surgical team of the Thoracic Surgery Department of the Shanghai Pulmonary Hospital. Perioperative data were collected and analysed. Survival data were collected via telephone calls. RESULTS Sixty-six of the 79 patients had a diagnosis of non-small-cell lung cancer, 47 of whom had squamous cell carcinoma. Twenty-one of the group with non-small-cell carcinoma were already at an advanced stage (III, IV) when operated on. The mean number of lymph node stations dissected was 5.5 ± 0.97 (4–8) and that of lymph nodes harvested was 13.7 ± 3.7 (5–23). A right upper lobectomy was the most common and time-consuming procedure. There was 1 conversion to a thoracotomy due to bleeding. No anastomotic-related complications were noted. The mean length of stay was 5.14 ± 1.56 (2–11) days. The 1- and 2-year survival rates were 98% and 80%, respectively. CONCLUSIONS Uniportal VATS sleeve resection is a safe and efficient procedure for the treatment of centrally located tumours otherwise requiring a pneumonectomy. [ABSTRACT FROM AUTHOR]

A framework is introduced for constructing interpretable and truly reliable reduced models for multiscale problems in situations without scale separation. Hydrodynamic approximation to the kinetic equation is used as an example to illustrate the main steps and issues involved. To this end, a set of generalized moments are constructed first to optimally represent the underlying velocity distribution. The well-known closure problem is then solved with the aim of best capturing the associated dynamics of the kinetic equation. The issue of physical constraints such as Galilean invariance is addressed and an active-learning procedure is introduced to help ensure that the dataset used is representative enough. The reduced system takes the form of a conventional moment system and works regardless of the numerical discretization used. Numerical results are presented for the BGK (Bhatnagar-Gross-Krook) model and binary collision of Maxwell molecules. We demonstrate that the reduced model achieves a uniform accuracy in a wide range of Knudsen numbers spanning from the hydrodynamic limit to free molecular flow. [ABSTRACT FROM AUTHOR]

To investigate the brittle ductile transformation characteristics of mudstone under high temperature, the MTS810 electro mechanical hydraulic servo test system and matched high temperature furnace MTS652.02 are used to perform mechanical tests to study the influence of loading rate on the yield strain and ductility coefficient of the mudstone at high temperatures. [ABSTRACT FROM AUTHOR]

Bio-drug is a new type of beneficial biology expressing therapeutic peptides (protein) as orally administrated medicine to treat diseases, in particular, chronic diseases like diabetes. In order to develop recombinant yeast strains as a bio-drug which could effectively ameliorate type 2 diabetes, an integrating expression vector pNK1-PGK that could successfully express green fluorescent protein (GFP) in Saccharomyces cerevisiae was constructed to demonstrate the normality of the function. A pNK1-PGK vector, which expresses 10 tandem repeats of long-acting glucagon-like peptide-1(10laGLP-1), was cloned and then transformed into the S. cerevisiae INVSc1. The long-acting GLP-1 hypoglycemic yeast (LHY168) that grew rapidly and expressed 10laGLP-1 stably was screened by uracil-deficient plates and Western blot. The expression quantity of 10laGLP-1 reached 1.56 mg/g cell wet weight. Moreover, the oral administration of LHY168 significantly declined the blood glucose in type 2 diabetic mice that were constructed through co-induction of streptozotocin (STZ) and high-fat and high-sugar diet. [ABSTRACT FROM AUTHOR]

Beibei pumpkin has the characteristics of early maturity, high yield, strong disease resistance, cold resistance, strong ability of continuous fruiting, excellent quality and easy cultivation, and its cultivation in spring greenhouse of Beijing region could effectively improve yield and commodity. In this paper, cultivation techniques of Beibei pumpkin in spring greenhouse are introduced, including cultivation of strong seedlings, planting, management after planting and storage after harvest. [ABSTRACT FROM AUTHOR]

Aiming at the problems of low standardization, unstable quality and low commodity rate of facility watermelon cultivation technology in Beijing, to meet the demand for high-quality and standardized supply capacity of the watermelon industry, the technical regulations for facility watermelon production in Beijing area were formulated, mainly including the environmental conditions of the producing area, cultivation techniques, pest control and harvesting. This regulation can provide a reference for the standardization of facility watermelon production. [ABSTRACT FROM AUTHOR]

Backgrounds/Aims: It has been reported that myocardial infarction (MI) is a risk factor for vascular dementia. However, the molecular mechanism remains largely unknown. Methods: MI mice were generated by ligation of the left coronary artery (LCA) for 4 weeks. Passive and active avoidance tests were performed to evaluate the cognitive ability of MI mice. A theta-burst stimulation (TBS) protocol was applied to elicit long-term potentiation (LTP) of the perforant pathway-dentate gyrus synapse (PP-DG). Western blot analysis was employed to assess protein levels. Results: In this study, we demonstrated that after 4 weeks of MI, C57BL/6 mice had significantly impaired memory. Compared with the sham group, in vivo physiological recording in the MI group revealed significantly decreased amplitude of population spikes (PS) with no effect on the latency and duration of the stimulus-response curve. The amplitude of LTP was markedly decreased in the MI group compared with the sham group. Further examination showed that the expression of the TBS-LTP-related proteins BDNF, GluA1 and phosphorylated GluA1 were all decreased in the MI group compared with those in the sham group. Strikingly, all these changes were prevented by hippocampal stereotaxic injection of an anti-miR-1 oligonucleotide fragment carried by a lentivirus vector (lenti-pre- AMO-1). Conclusion: MI induced cognitive decline and TBS-LTP impairment, and decreased BDNF and GluA1 phosphorylation levels from overexpression of miR-1ated were involved in this process. [ABSTRACT FROM AUTHOR]

This experiment mainly monitored the high-density planting conditions of small watermelons in spring greenhouses in Beijing by US350 environmental sensors. Besides,it analyzed the requirements for environmental factors in different growth stages of watermelons. The experiment obtained the following results.( i) Under the condition of high-density planting of small watermelons,the average air temperature range was 17. 48-21. 16°C at the seedling hardening stage,the average air temperature range was 16. 68-25. 53°C at the tendril elongation stage,and the average air temperature range was 15. 98-32. 06°C at the fruiting stage. The average soil temperature range was 20. 56-23. 03°C at the seedling hardening stage,the average soil temperature range was 20. 44-25. 51°C at the tendril elongation stage,and the average soil temperature range was 18. 72-28. 84°C at the fruiting stage. The average light intensity range was 2 359. 15-8 207. 44 Lux at the seedling hardening stage,the average light intensity range was 551. 98-9 170. 77 Lux at the tendril elongation stage,and the average light intensity range was 1 253. 59-9 644. 01 Lux at the fruiting stage. The average relative humidity range was 60. 69%-76. 40% at the seedling hardening stage,the average relative humidity range was 60. 85%-89. 89% at the tendril elongation stage,and the average relative humidity range was 42. 14%-93. 00% at the fruiting stage. The CO2 concentration range was 455-631 m L/m3 at the growth stage. [ABSTRACT FROM AUTHOR]

Flowers are highly complex organs that have evolved to enhance the reproductive success of angiosperms. As a key component of flowers, petals play a vital role in attracting pollinators and ensuring successful pollination. Having fulfilled this function, petals senesce through a process that involves many physiological and biochemical changes that also occur during leaf senescence. However, petal senescence is distinct, due to the abundance of secondary metabolites in petals and the fact that petal senescence is irreversible. Various phytohormones are involved in regulating petal senescence, and are thought to act both synergistically and antagonistically. In this regard, there appears to be developmental point during which such regulatory signals are sensed and senescence is initiated. Here, we review current understanding of petal senescence, and discuss associated regulatory mechanisms involving hormone interactions and epigenetic regulation. [ABSTRACT FROM AUTHOR]

China's massive urbanisation development will undoubtedly serve as a global reference. Due to the uncertainty of statistical data, nighttime light (NTL) data have emerged as alternative data for urbanisation evaluation. Here, the application of the Prolonged Artificial NTL Dataset of China (1984-2020) has been newly expanded. Total-value statistical, complex NTL index (CNLI), NTL concentration degree, rank-size rule, and Markov transfer matrix were used to systematically mine information about urban change from multiple perspectives. China's urbanisation exhibited rapid growth and outwards expansion. The total percentage increase in NTL brightness and NTL area was 409.38% and 302.58%, respectively. The Yangtze River Delta urban agglomeration of East China had the fastest urbanisation (CNLI Trend = 0.0057/a, p < 0.01). Low NTL areas transitioned to medium NTL areas, and high and extremely-high NTL areas diffused to medium NTL areas. The cities in Eastern China and Southern China typically exhibited extremely-high type NTL areas, whereas other cities primarily exhibited medium NTL areas. The gaps between city sizes decreased over time (q Trend = -- 0.0200/a, p < 0.01). Lowest-ranked cities exhibited the highest stability (>95%) in city size type transition. The spatiotemporal changes in NTL obtained were of great significance for monitoring urban expansion patterns, making government decisions, and quantifying China's sustainable development. [ABSTRACT FROM AUTHOR]

Atherosclerosis (AS) is a progressive disease of multifactorial origin, which occurs in response to endothelial injury. Increased homocysteine (Hcy) is considered a major cause of endothelial dysfunction, oxidative stress and DNA methylation; however, the mechanisms remain to be fully elucidated. The aim of the present study was to investigate whether Hcy causes injury to endothelial cells (ECs) by the effect of lectin-like oxidized-low density lipoprotein receptor-1 (LOX-1) DNA methylation through toll-like receptor 4(TLR4)/nuclear factor (NF)-κB/DNA methyltransferase (DNMT)1. The ECs were treated with different concentrations of Hcy, and it was found that Hcy promoted the expression of TLR4, leading to EC injury. The effect of oxidative stress was analyzed by measuring superoxide dismutase, malondialdehyde and hydrogen peroxide in the ECs. In addition, the association between NF-κB and DNMT1 was examined by treatment of the ECs with pyrrolidine dithiocarbamate (PDTC). The results suggested that Hcy induced LOX-1 DNA hypomethyaltion to promote the expression levels of LOX-1. Taken together, Hcy injured the ECs through the effect of methylation and trans-sulfuration metabolism of LOX-1 through TLR4/NF-κB/DNMT1. Following injury to the ECs, lipids, particularly ox-LDL, accumulated in the sub-endothelial layer to promote the formation of AS. [ABSTRACT FROM AUTHOR]

A thermal camera captures the temperature distribution of a scene as a thermal image. In thermal images, facial appearances of different people under different lighting conditions are similar. This is because facial temperature distribution is generally constant and not affected by lighting condition. This similarity in face appearances is advantageous for face detection. To detect faces in thermal images, cascade classifiers with Haar-like features are generally used. However, there are few studies exploring the local features for face detection in thermal images. In this paper, we introduce two approaches relying on local features for face detection in thermal images. First, we create new feature types by extending Multi-Block LBP. We consider a margin around the reference and the generally constant distribution of facial temperature. In this way, we make the features more robust to image noise and more effective for face detection in thermal images. Second, we propose an AdaBoost-based training method to get cascade classifiers with multiple types of local features. These feature types have different advantages. In this way we enhance the description power of local features. We did a hold-out validation experiment and a field experiment. In the hold-out validation experiment, we captured a dataset from 20 participants, comprising 14 males and 6 females. For each participant, we captured 420 images with 10 variations in camera distance, 21 poses, and 2 appearances (participant with/without glasses). We compared the performance of cascade classifiers trained by different sets of the features. The experiment results showed that the proposed approaches effectively improve the performance of face detection in thermal images. In the field experiment, we compared the face detection performance in realistic scenes using thermal and RGB images, and gave discussion based on the results. [ABSTRACT FROM AUTHOR]

Background: The light/dark cycle is one of the most important factors affecting the microalgal growth and lipid accumulation. Biomass concentration and lipid productivity could be enhanced by optimization of light/dark cycles, and this is considered an effective control strategy for microalgal cultivation. Currently, most research on effects of light/dark cycles on algae is carried out under autotrophic conditions and little information is about the effects under mixotrophic cultivation. At the same time, many studies related to mixotrophic cultivation of microalgal strains, even at large scale, have been performed to obtain satisfactory biomass and lipid production. Therefore, it is necessary to investigate cellular metabolism under autotrophic and mixotrophic conditions at different light/dark cycles. Even though microalgal lipid production under optimal environmental factors has been reported by some researchers, the light/dark cycle and temperature are regarded as separate parameters in their studies. In practical cases, light/dark cycling and temperature variation during the day occur simultaneously. Therefore, studies about the combined effects of light/dark cycles and temperature variation on microalgal lipid production are of practical value, potentially providing significant guidelines for large-scale microalgal cultivation under natural conditions. Results: In this work, cell growth and lipid accumulation of an oleaginous microalgal mutant, Scenedesmus sp. Z-4, were investigated at five light/dark cycles (0 h/24 h, 8 h/16 h, 12 h/12 h, 16 h/8 h, and 24 h/0 h) in batch culture. The results showed that the optimal light/dark cycle was 12 h/12 h, when maximum lipid productivity rates of 56.8 and 182.6 mg L-1 day-1 were obtained under autotrophic and mixotrophic cultivation, respectively. Poor microalgal growth and lipid accumulation appeared in the light/dark cycles of 0 h/24 h and 24 h/0 h under autotrophic condition. Prolonging the light duration was unfavorable to the production of chlorophyll a and b, which was mainly due to photooxidation effect. Polysaccharide was converted into lipid and protein when the light irradiation time increased from 0 to 12 h; however, further increasing irradiation time had a negative effect on lipid accumulation. Due to the dependence of autotrophically cultured cells on light energy, the light/dark cycle has a more remarkable influence on cellular metabolism under autotrophic conditions. Furthermore, the combined effects of temperature variation and light/dark cycle of 12 h/12 h on cell growth and lipid accumulation of microalgal mutant Z-4 were investigated under mixotrophic cultivation, and the results showed that biomass was mainly produced at higher temperatures during the day, and a portion of biomass was converted into lipid under dark condition. Conclusions: The extension of irradiation time was beneficial to biomass accumulation, but not in favor of lipid production. Even though effects of light/dark cycles on autotrophic and mixotrophic cells were not exactly the same, the optimal lipid productivities of Scenedesmus sp. Z-4 under both cultivation conditions were achieved at the light/dark of 12 h/12 h. This may be attributed to its long-term acclimation in natural environment. By combining temperature variation with optimal light/dark cycle of 12 h/12 h, this study will be of great significance for practical microalgaebiodiesel production in the outdoor conditions. [ABSTRACT FROM AUTHOR]

Vascular smooth muscle cell (VSMC) proliferation is a primary pathological event in atherosclerosis (AS), and homocysteine (Hcy) is an independent risk factor for AS. However, the underlying mechanisms are still lagging. Studies have used the combination of methylation of promoters of multiple genes to diagnose tumors, thus the aim of the current study was to investigate the role of methylation status of several genes in VSMCs treated with Hcy. CpG islands were identified in the promoters of platelet‑derived growth factor (PDGF), p53, phosphatase and tensin homologue on chromosome 10 (PTEN) and mitofusin 2 (MFN2). Hypomethylation was observed to occur in the promoter region of PDGF, hypermethylation in p53, PTEN and MFN2, and hypomethylation in two global methylation indicators, aluminium (Alu) and long interspersed nucleotide element‑1 (Line‑1). This was accompanied by an increase in the expression of PDGF, and reductions of p53, PTEN and MFN2, both in mRNA and protein levels. An elevation of S‑adenosylmethionine (SAM) and a reduction of S‑adenosylhomocysteine (SAH) and the SAM/SAH ratio were also identified. In conclusion, Hcy impacted methylation the of AS‑associated genes and global methylation status that mediate the cell proliferation, which may be a character of VSMCs treated with Hcy. The data provided evidence for mechanisms of VSMCs proliferation in AS induced by Hcy and may provide a new perspective for AS induced by Hcy. [ABSTRACT FROM AUTHOR]

Intrahepatic cholangiocarcinoma (ICC) arises from the biliary epithelium and is a relatively rare and highly fatal neoplasm. The prognosis is poor, and survival is limited to a few months. Here, we report a case of advanced ICC that was successfully treated with apatinib, a new oral tyrosine kinase inhibitor that targets the intracellular domain of vascular endothelial growth factor receptor-2. To the best of our knowledge, this is the first case report of the successful use of apatinib for advanced ICC; this treatment has demonstrated fewer toxic effects than traditional cytotoxic chemotherapy. The progression-free survival time was 8 months. The only toxicity observed was mild hand–foot syndrome. Therefore, apatinib may be an additional option for the treatment of advanced ICC, but further prospective studies are needed to optimize the treatment. [ABSTRACT FROM AUTHOR]

In this paper, we propose several approaches to improve the efficiency of the optimization design for dry-type aircore reactors. Above all, by virtue of the empirical formula of the inductance of short solenoids, a neat formula for the inner diameter corresponding to the minimum mass of the reactor, termed optimal inner diameter, is presented, and a favorable range of the inner diameter is determined accordingly. Then, an efficient optimization model is established without frequently and repeatedly adjusting the design variables. In addition, genetic algorithm for the optimization design of the reactor is improved by introducing linear scaling and a dynamic mutation operator. The proposed approaches are tested on the single-phase dry-type air-core reactor of 50 kVar with round conductors. An economic and qualified result can be obtained in a short period of time after the application of the approaches. The merits of these approaches could be more obvious for the large-capacity reactors. [ABSTRACT FROM AUTHOR]

Capacitive coupling intra-body communication (CC-IBC) has become one of the candidates for healthcare sensor networks due to its positive prevailing features of energy efficiency, transmission rate and security. Under the CC-IBC scheme, some of the electric field emitted from signal (SIG) electrode of the transmitter will couple directly to the ground (GND) electrode, acting equivalently as an internal impedance of the signal source and inducing considerable energy losses. However, none of the previous works have fully studied the problem. In this paper, the underlying theory of such energy loss is investigated and quantitatively evaluated using conventional parameters. Accordingly, a method of electric active shielding is proposed to reduce the displacement current across the SIG-GND electrodes, leading to less power loss. In addition, the variation of such loss in regard to frequency range and positions on human body was also considered. The theory was validated by finite element method simulation and experimental measurement. The prototype result shows that the receiving power has been improved by approximate 5.5 dBm while the total power consumption is maximally 9 mW less using the proposed technique, providing an energy efficient option in physical layer for wearable and implantable healthcare sensor networks. [ABSTRACT FROM AUTHOR]

This paper investigates the problem of reliable finite-time H∞ control for one class of uncertainsingular nonlinear Markovian jump systems with time-varying delay subject to partial information on the transition probabilities. Continuous fault model is more general and practical to serve as the actuator fault. Time delay is a kind of positive time-varying differentiable bounded delays. First, based on a state estimator the resulting closed-loop error system is constructed and sufficient criteria are provided to guarantee that the augmented systemis singular stochastic finite-time boundedness and singular stochastic H∞ finite-time boundedness in both normal and fault cases via constructing a delay-dependent Lyapunov-Krasonskii function. Then, the gain matrices of state-feedback controller and state estimator are fixed by solving a feasibility problem in terms of linear matrix inequalities through decoupling technique, respectively. Finally, numerical examples are given to show the validity of the proposed design approach. [ABSTRACT FROM AUTHOR]

We herein report the fabrication of a palladium nanoparticles (Pd NPs) loaded homochiral covalent organic framework using S-(+)-2-methylpiperazine and cyanuric chloride (Pd@CCOF-MPC) (2) via a very facile chemical approach. The chiral COF support of 1 (CCOF-MPC) is synthesized by the combination of cyanuric chloride and S-(+)-2-methylpiperazine at 90 °C for 36 h, and the Pd NPs-loaded Pd@CCOF-MPC (2) is prepared via sequential solution impregnation and NaBH4 reduction at room temperature. 2, as a highly active reusable asymmetric heterogeneous composite catalyst, is able to effectively promote the Henry reaction and reductive Heck reaction in high yield with excellent stereoselectivity. [ABSTRACT FROM AUTHOR]

The interfacial region plays a critical role in determining the electrical properties of dielectric nanocomposites. The current state-of-the-art interfacial modification is predominantly based on utilizing flexible organic molecules, which are random polymer coils and generally collapse on the surface of any modified nanoparticles. This work focused on engineering the interfacial region between Na2Ti3O7 nanofibers and polymer matrix and, for the first time, utilized the liquid-crystalline polymer poly{2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene} (PMPCS) to modulate the interface where the rigid polymer was forced to form a straight conformation. Owing to the rigidity and orientation of PMPCS, a series of core-shell structured Na2Ti3O7@PMPCS nanofibers with finely tuned shell thickness were prepared. The prepared Na2Ti3O7@PMPCS/P(VDF-HFP) nanocomposites showed significantly different permittivity from 10.7 to 69.6 at 1 kHz with the gradient thicknesses of PMPCS shell. These results effectively proved that modulating the interfacial layer thickness in the dielectrics nanocomposites is also a method to modulating the dielectric property. [ABSTRACT FROM AUTHOR]