Molecular cloning and functional analysis of two calcium associated cuticular protein genes in Neocaridina denticulata sinensis

The body surface of crustaceans is covered with a sturdy shell.The growth and development of crustaceans are realized through molting.Neocaridina denticulata sinensis is a suitable candidate for crustacean scientific research.Two calcium-associated cuticular protein genes,named NdCAP-1 and NdCAP-2,were obtained from N.denticulata sinensis.Molecular docking simulated the binding effect of both proteins and calcium ions.Semi-quantitative reverse transcription PCR results show that NdCAP-1 is expressed in D_(2-4) stage,NdCAP-2 expressed in D_(2-4) and A-B stages,and both were significantly expressed in the cephalothorax cuticle and pereiopods.Then,it was revealed that NdCAP-1 and NdCAP-2 are regulated by NdEcR-mediated 20 E signaling pathways.Knockdown of NdCAP-1 and NdCAP-2 was observed to cause surface defects.The recombinant proteins(rNdCAP-1 and rNdCAP-2),obtained by prokaryotic expression,had calcium-binding and chitin-binding ability,inhibited formation of calcium carbonate precipitate.These results show that calcium-associated cuticular proteins play important roles in cuticle formation and calcification.

近视激光角膜屈光术后屈光回退机制与药物防治的研究进展

激光角膜屈光手术作为矫治近视的有效方法,其术后长期稳定性是医生及患者所共同关注的问题。然而,屈光回退仍是术后常见的远期并发症之一,对于术后的屈光状态及视觉质量都有较大影响。屈光回退可能与角膜上皮及基质重塑、角膜生物力学与眼压失衡等因素有关。尽管增效手术可达到治疗屈光回退的目的,但存在角膜扩张等风险。某些降眼压药物可望重新建立眼压与角膜生物力学的平衡关系,并通过影响角膜上皮厚度以防治术后屈光回退。降眼压药物的选择、作用时间与方式等,均可能对屈光回退的防治效果产生一定影响。

Scorpion venom heat-resistant protein decreases immunoreactivity of OX-42-positive microglia cells in MPTP-treated mice

BACKGROUND： Microglia function as the immune surveyors of the brain under normal physiologica conditions. However, microglia become activated in response to brain injuries and immunological OBJECTIVE： To explore the influence of scorpion venom （SV） heat-resistant protein on frontal cortex and hippocampal microglia cells in a mice model of Parkinson＇s disease. DESIGN, TIME AND SETTING： Randomized, controlled, cellular immunity study. The experiment was performed at the Physiology Department Laboratory in Dalian Medical University between June 2005 and July 2008. MATERIALS： Ninety-six healthy, C57B1/6 mice; 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine （MPTP） from Sigma, USA; SV heat-resistant protein （Experimental Base Institute in Dalian Medical University）. The mice were randomly divided into four groups （n = 24）： normal control, negative control, model, and SV heat-resistant protein. METHODS： Mice in the model and SV heat-resistant protein groups were subcutaneously injected with MPTP （20 mg/kg） to model Parkinson＇s disease, while the normal control and negative control groups were injected with physiological saline in the neck for 8 successive days. In addition, mice in the model and normal control groups were intraperitoneally injected with physiological saline 2 hours following administration, while SV heat-resistant protein and negative control groups were injected SV heat-resistant protein （0.01 mg/kg）. MAIN OUTCOME MEASURES： lmmunoreactivity of microglia cells in MPTP-treated mice. RESULTS： Compared with normal control mice, MPTP-treated mice displayed increased OX-42 expression in the brain. However, in the SV heat-resistant protein-treated mice, OX-42 expression was decreased, compared to the model group. In the model mouse group, the number of OX-42-positive microglia was increased in the frontal cortex, caudatum, and hippocampal hilus, compared to the normal control mice （P 〈 0.01）. However, in the SV heat-resistant protein-treated mice, the number of OX-42-positive microglia significantly decreased in the frontal cortex, caudatum, and hippocampal hilus, compared to the model group （P 〈 0.01）. CONCLUSION： SV heat-resistant protein inhibited MPTP-induced microglial activation in the mouse frontal cortex and hippocampus, resulting in reduced microglial activation in the brain.

串列叶栅和叶片弯曲对角区失速和叶尖泄漏流的耦合作用

为了提高压气机叶栅的气动性能,本文针对高负荷串列叶栅进行数值模拟,研究了叶片正弯和串列叶栅对角区失速和叶尖泄漏流的耦合作用。结果表明,在串列叶栅前叶排存在比较严重的角区失速,叶片正弯能有效控制高负荷串列叶栅中的角区失速,在最优工况叶栅总损失降低了37.6%。串列叶栅中只有"前排叶片弯曲"的方案能取得与"两排叶片都弯曲"方案相似的控制效果,但由于"两排叶片都弯曲"方案对两排叶片都有控制作用,从而获得了更低的总压损失。叶尖泄漏流可以有效控制上端壁处的角区失速,同时也会带来泄漏流损失。叶尖间隙越大,叶栅的总压损失越小,叶栅中涡结构也会越复杂。大间隙下,叶尖泄漏涡和通道涡的位置与一般压气机叶栅不同,两排叶片各自生成的泄漏涡会在叶栅后汇聚成一个涡,通道涡由叶栅中的低能流体与一部分泄漏流组成。弯曲叶片主要作用是控制角区失速,对叶尖泄漏流的影响不明显。

High-performance lens antenna using high refractive index metamaterials

In this paper, a high refractive index metamaterial （HRM）, whose element is composed of bilayer square patch （BSP） spaced by a dielectric plate, is proposed. By reducing the thickness of the dielectric plate and the gap between adjacent patches, the BSP can effectively enhance capacitive coupling and simultaneously suppress diamagnetic response, which significantly increases the refractive index of the proposed metamaterial. Furthermore, the high refractive index region is far away from the resonant region of the metamaterial, resulting in broadband. Based on these characteristics of BSP, a gradient refractive index （GRIN） lens with thin thickness （0.34/~0, where 2~0 is the wavelength at 5.75 GHz） is designed. By using this lens, we then design a circularly polarized horn antenna with high performance. The measurement results show that the 3-dB axial ratio bandwidth is 34.8% （4.75 GHz-6.75 GHz） and the antenna gain in this frequency range is increased by an average value of 3.4 dB. The proposed method opens up a new avenue to design high-performance antenna.

Approaches and Perspectives of the Westward Spread of Traditional Chinese Medicine: A Case Study of the Radicis Chynae

Some Western scholars have re-examined the concept of“Chinese medicine”and its knowledge system under the influence of global history research methods in recent years,in an attempt to understand the factors that led to the spread of Chinese medicine around the world,and what kind of Chinese medicine is constituted outside of China.Thus,researchers have studied the initial stage of traditional Chinese medicine(TCM)’s entry into the western world,tracing its roots and observing new knowledge systems formed in the process of cross-cultural communication.Responding to the research of Western scholars,this paper studies the Radicis Chynae(《中国根书简》Letters on Chinese Root),a monograph written by Andreas Vesalius,a famous European anatomist who lived in the 16th century.The author of this article examined the understanding and interpretation of Chinese medicine by the European intelligentsia from 16th to 19th century,investigated the influence of the westward spread of TCM on the scientific revolution and medical progress in Europe,and analyzed its relationship with the rise of Sinology in Europe.This article discusses the knowledge interaction between Chinese medicine and the formation of modern European medicine from the perspective of global history and cross-culture.

Analyses on Community Composition and Diversity of Endophytic Bacteria in Different Tissues of Anoectochilus roxburghii

[Objective] This study aimed to investigate the diversity of community composition and diversity of endophytic bacteria in Anoectochilus roxburghii.[Method] By using Illumina MiSeq high-throughput sequencing technology, the 16S rDNA-V4 region of endophytic bacteria in ^4. roxburghii was sequenced. Qiime and Mothur software packages were used to sort and count the number of sequences and operational taxonomic units （OTUs） and analyze the species abundance and distribution, Alpha diversity and differences of species abundance among samples. [Result] The number of effective sequences/OTUs for each sample was 110485/247 （stem） and 98524/259 （leaf） , respectively. The rarefaction curve showed that adequate sampling was performed. The number of OTUs had almost reached a saturation point. Endophytic bacteria in A. roxburghii mainly belonged to the genera Acidovorax, Pseudomonas, Sphingomonas and Halomonas. [Conclusions] Illumi-na MiSeq high-throughput sequencing technology provides more accurate and scientific data resources for the study of endophytic bacteria in A. roxburghii.

Germanium-tin alloys： applications for optoelectronics in mid-infrared spectra

We summarize our work of the optoelectronic devices based on Germanium-tin （GeSn） alloys assisted with the Si3N4liner stressor in mid-infrared （MIR） domains. The device characteristics are thoroughly analyzed by the strain distribution,band structure, and absorption characteristics. Numerical and analytical methods show that with optimal structural pa-rameters, the device performance can be further improved and the wavelength application range can be extended to 2~5 μm in the mid-infrared spectra. It is demonstrated that this proposed strategy provides an effective technique for the strained-GeSn devices in future optical designs, which will be competitive for the optoelectronics applications in mid-infrared wavelength.

The Cognitive Evolution from“Plague”to“Infectious Disease”

According to the Grand Chinese Dictionary,plague is defined to be an acute infectious disease.The Chinese term“infectious disease”is not what it is commonly thought originated from Japanese.The medical nomenclature shift from the traditional“plague”to the modern“infectious disease”is completed by the medical missionaries,Chinese scholars,and the national authority,each utilising different strategies.It is a history of acceptance concerning the concept of“infectious disease”from academia to national level.The conscious use of infectious disease-related thought and terminology by Chinese officials and doctors when studying infectious disease is a scientific modernization towards the understanding of epidemics.In a sense,this evolution of medical knowledge embodies the modernization of infectious disease in China.

CFD simulation of bubbly turbulent Tayor–Couette flow

Bubbly gas-liquid Taylor-Couette vortex flow has been the subject of several recent investigations both because of interest in bubble-induced drag reduction and because such devices have potential applications to a variety of chemical and biochemical processing problems. In order to quantitatively describe the hydrodynamics of highly turbulent two phase Taylor-Couette flow, a rigorous two-fluid computational fluid dynamics （CFD） model was developed and compared with previously published experimental data. This model includes a comprehensive description of the constitutive closure for inter-phase forces and turbulence was simulated using both the k- and k-to models. In addition, the mechanism by which the dispersed fluid attains a non-uniform radial and axial distribution is analyzed and the relative importance of various interphase forces is discussed. Lastly the model was validated by comparison of simulation predictions with experimental data, and it is shown that the CFD model correctly predicts phase velocity, velocity fluctuation, and gas distribution, and may provide guidance for reactor design and scale-up.

Enhanced red luminescence of Ca_(3)Si_(2−x)M_(x)O_(7):Eu^(3+)(M=Al,P)phosphors via partial substitution of Si^(4+) for applications in white light-emitting diodes

A red-emitting phosphor Ca_(2.91)Si_(2)O_(7):0.09Eu^(3+) with partial Al^(3+)/P^(5+) substitution on Si^(4+) was synthesized via a simple solid-state method,and the effects of the introduction of the M^(3+/5+)(M=Al,P)ions on the crystal structure and photoluminescence performance of Ca_(2.91)Si_(2−x)M_(x)O_(7):0.09Eu^(3+) phosphors were investigated.The X-ray diffraction(XRD),energy-dispersive X-ray spectroscopy(EDS),and X-ray photoelectron spectroscopy(XPS)results revealed that the structure of Ca_(3)Si_(2)O_(7) remained the same after the introduction of Al^(3+) and P^(5+) ions.The characteristic emission of Eu^(3+)-doped Ca_(3)Si_(2−x)M_(x)O_(7) phosphors exhibited two main peaks at 617 nm(red)and 593 nm(orange)under excitation at 394 nm,which originated from the^(5)D_(0)→^(7)F_(2)and^(5)D_(0)→^(7)F_(1) electron transitions of Eu^(3+) ions.After the partial substitution of Al^(3+) and P^(5+),the red emission intensities of the Ca_(2.91)Si_(2)O_(7):0.09Eu^(3+) phosphors were significantly enhanced by 1.88-and 1.42-fold,respectively,which is attributed to the crystal-field effect around Eu^(3+).Meanwhile,the luminescence intensities of the Ca_(2.91)Si_(1.96)Al_(0.04)O_(7):0.09Eu^(3+) and Ca_(2.91)Si_(1.94)P_(0.06)O_(7):0.09Eu^(3+) phosphors at 210℃ were 79.36%and 77.53%of those at 30°C,respectively,indicating their excellent thermal stability.Moreover,the as-prepared Ca_(2.91)Si_(1.96)Al_(0.04)O_(7):0.09Eu^(3+)and Ca_(2.91)Si_(1.94)P_(0.06)O_(7):0.09Eu^(3+) red-emitting phosphors were combined with a near-ultraviolet chip of 395 nm to fabricate red-light-emitting diode(LED)and white(w)-LED devices with excellent chromaticity features.In summary,Al^(3+)/P^(5+)-substituted Ca_(2.91)Si_(2)O_(7):0.09Eu^(3+) can serve as red-emitting phosphors for applications in w-LEDs.

Ensemble learning system to identify nutritional risk and malnutrition in cancer patients without weight loss information

Dear Editor,Malnutrition is a prevalent disease in oncology practice(Arends et al.,2017).With its cancer-specific prevalence ranging from 21%–72%,malnutrition is responsible for 10%–20% cancer deaths(Yin et al.,2021b).However,malnutrition is often underestimated,misclassified,or left untreated in cancer care(Hébuterne et al.,2014).

A reconfigurable terahertz polarization converter based on metal–graphene hybrid metasurface

A metal-graphene hybrid metasurface polarization converter is designed in this Letter.The unit cell of the hybrid metasurface is composed of a butterfly-shaped structure whose branches are connected by multi-layer graphene sheets.The proposed device can be reconfigured from linear-to-circular polarization to cross-polarization by changing the Fermi energy of graphene.The simulation results show that for three-layer graphene,the device acts as a linear-to-circular polarization converter when EF=0 eV and switches to a cross-polarization converter when EF=0.5 eV.Compared with single-layer graphene,the device with three-layer graphene can maintain the cross-polarization conversion performance under low Fermi energy.Furthermore,two equivalent circuits in the x and y directions are developed to understand the working mechanism of the device.

Do significant risk warnings in annual reports increase corporate bond credit spreads? Evidence from China

Based on listed companies issuing bonds on the Shanghai and Shenzhen Stock Exchanges from 2007 to 2017, this study analyzes the relationship between significant risk warnings in Chinese companies’ annual reports and corporate bond credit spreads. The main findings are as follows. First, in the Chinese market, ‘‘substantial warnings of significant risks' can significantly improve corporate bond credit spreads, reflecting the risk-warning effect;second,state-owned property rights weaken this effect, which only pertains to listed companies with poor risk management and low information quality;third, significant risk warnings increase investors’ heterogeneous beliefs, also affecting credit spreads;and fourth, through textual analysis, it is found that the corporate bond credit spread is greater when the disclosed risk factors are more pessimistic and less similar to those of the previous year. The findings of this paper help to enrich the literature on credit spreads and risk disclosure.

Development and validation of SuperDEM for non-spherical particulate systems using a superquadric particle method

This article presents the development and validation of the Superquadric Discrete Element Method(SuperDEM)for non-spherical particle simulation using a superquadric particle method in open-source CFD suite MFiX.A superquadric particle-particle contact algorithm with accelerating and stabilizing strategy was developed.A superquadric particle-arbitrary wall contact algorithm was developed,which enables the simulation in complex geometry.The solver was validated by comparing with experimental data generated in this study or available in the literature.Tests include cylinder contacting with a wall,static packing of M&M chocolate candies in a cylindrical container,static packing of cylinders in a cylindrical container,dynamic angle of repose of cylinders in a rotating drum,and discharging of chocolate candies from a hopper.Besides,MPI parallelization of the solver was implemented and the parallel performance of the solver using MPI was assessed through large-scale simulations of 1 million,10 million,and 100 million particles on up to 6800 cores,which demonstrates that the SuperDEM solver has great potential for industrial-scale systems simulation.