Osteoarthritis (OA) is a degenerative disease resulting from progressive joint destruction caused by many factors. Its pathogenesis is complex and has not been elucidated to date. Advanced glycation ...end products (AGEs) are a series of irreversible and stable macromolecular complexes formed by reducing sugar with protein, lipid, and nucleic acid through a non-enzymatic glycosylation reaction (Maillard reaction). They are an important indicator of the degree of ageing. Currently, it is considered that AGEs accumulation in vivo is a molecular basis of age-induced OA, and AGEs production and accumulation in vivo is one of the important reasons for the induction and acceleration of the pathological changes of OA. In recent years, it has been found that AGEs are involved in a variety of pathological processes of OA, including extracellular matrix degradation, chondrocyte apoptosis, and autophagy. Clearly, AGEs play an important role in regulating the expression of OA-related genes and maintaining the chondrocyte phenotype and the stability of the intra-articular environment. This article reviews the latest research results of AGEs in a variety of pathological processes of OA, to provide a new direction for the study of OA pathogenesis and a new target for prevention and treatment. Cite this article:
2022;11(5):292-300.
•Fundamental frequencies and dynamic response of the tubes were obtained by modal and dynamic tests.•Velocities and vortex shedding frequencies of the cross flow near the tubes were ...calculated.•Considering the cross flow loads, the dynamic response and max stress of the tubes were calculated.
The nuclear engineering test reactor in this paper is a small nuclear reactor designed and manufactured in China. The structure of this nuclear reactor is different from the normal pressurized water reactors. Especially, these are some tubes in the nuclear reactor, which are named radiation tube, neutron tube and temperature tube. The vibration induced in the flexible tubes by vortex shedding is practical importance, which is related to the safety of this nuclear reactor. However, it is difficult to obtain the natural frequencies and the dynamic characteristics of the tubes with the undetermined boundary conditions only by numerical analysis. In this paper, a 1/2 scaled-down model of this nuclear reactor was manufactured, and the modal experiment was made to obtain the natural frequencies both in air and in water. Based on the results of the modal test in air and water, the restraint stiffness of the tubes was calculated. Then, CFD analysis was made to calculate the velocities and the vortex shedding frequencies of the flow near the tubes and the vibration equations of the tubes were presented to calculate the dynamic responses of the tubes. A dynamic test was also made to verify the accuracy of the calculation. Compared the results of numerical calculation to the results of dynamic test, it is obvious that the numerical analysis method can reflect the dynamic characteristics of the scaled-down model with a valid margin of error.
In this work, high‐purity HfSi2 powders were successfully fabricated via a molten salt‐assisted magnesium thermal reduction method using HfO2 and Si as raw materials. The effects of reaction ...temperature and time on the formation of HfSi2 were systemically investigated. The morphological and phase composition of as‐prepared HfSi2 powders were characterized by scanning electron microscopy, transmission electron microscopy, X‐ray diffraction, and nitrogen/oxygen determinator. The results indicated that as‐obtained HfSi2 powders possess the orthorhombic structure with approximately 6.4 μm in size and the oxygen content as low as 0.20%. This work can provide a novel route to fabricate the high‐purity transition metal silicides powders.
To reduce the floor space of receiving antenna arrays, the Radio Ocean Remote SEnsing (RORSE) laboratory of Wuhan University developed a circular receiving array for a multi-frequency high frequency ...(MHF) radar system in 2014, consisting of seven uniformly spaced antenna elements positioned on a circle with a diameter of 5 m. The new system, which is abbreviated MHF-C radar, adopts frequency modulated interrupted continuous wave (FMICW) chirps and is capable of simultaneously operating at a maximum of four frequencies in the band of 7.5–25 MHz, and providing current, wave and wind maps every ten minutes. The phase direction-finding method is utilized to estimate the directions of the current signals, and array phase uncertainties are also taken into consideration in the signal model. This paper introduces the system in detail and investigates the performance of current measurements using MHF-C radars installed at Shengshan and Zhujiajian along the coast of the East China Sea. Radial current measurements derived from 8.27 MHz and 19.20 MHz at the same range are compared. Observations and comparisons between MHF-C radars and acoustic Doppler current profilers (ADCPs) are also presented in this paper. The results preliminarily demonstrate that the MHF-C radar system is capable of maintaining the same performance for current measurements whenever it steers to any other azimuth in the coverage and has a good ability to measure currents.
Urea is one of the uremic toxins threating people’s health. Herein, we prepared a kind of urease-immobilized beads to remove urea, which exhibited good hemocompatibility and high removal efficiency. ...Urease was covalently grafted onto carboxyl-group-functionalized polyethersulfone beads, which were previously prepared by in situ cross-linking polymerization and phase inversion methods. The urease-immobilized beads had sufficient blood compatibility with low protein adsorption amount, undiminished clotting times, low hemolysis ratio, and suppressed complement activation and contact activation. Furthermore, the urease-immobilized beads showed good urea removal ability with a urea removal amount of 75.1 mg/g after incubating in 80 mg/dL urea solution for 480 min. In addition, the prepared urease-immobilized beads could maintain urea removal activity after being used for five cycles and showed satisfied activity even when stored for 15 days in phosphate buffer saline solution. Thus, the urease-immobilized beads may meet the potential application demand for safe and effective blood detoxification.
Fluorescence polarization microscopy (FPM) analyzes both intensity and orientation of fluorescence dipole, and reflects the structural specificity of target molecules. It has become an important tool ...for studying protein organization, orientational order, and structural changes in cells. However, suffering from optical diffraction limit, conventional FPM has low orientation resolution and observation accuracy, as the polarization information is averaged by multiple fluorescent molecules within a diffraction-limited volume. Recently, novel super-resolution FPMs have been developed to break the diffraction barrier. In this review, we will introduce the recent progress to achieve sub-diffraction determination of dipole orientation. Biological applications, based on polarization analysis of fluorescence dipole, are also summarized, with focus on chromophore-target molecule interaction and molecular organization.
High temperatures, particularly at night, decrease rice yield and quality. As high nighttime temperatures (HNTs) become increasingly frequent due to climate change, it is imperative to develop rice ...crops that tolerate HNTs. DNA methylation may represent a potential avenue for HNT-tolerant rice strain development, as this mechanism regulates gene activity and cellular phenotype in response to adverse environmental conditions without changing the nucleotide sequence.
After HNT exposure, the methylation patterns of cytosines in the CHH context differed noticeably between two coisogenic rice strains with significantly different levels in heat tolerance. Methylation differences between strains were primarily observed on successive cytosines in the promoter or downstream regions of transcription factors and transposon elements. In contrast to the heat-sensitive rice strain, the regions 358-359 bp and 2-60 bp downstream of two basal transcriptional factors (TFIID subunit 11 and mediator of RNA polymerase II transcription subunit 31, respectively) were fully demethylated in the heat-tolerant strain after HNT exposure. In the heat-tolerant strain, HNTs reversed the methylation patterns of successive cytosines in the promoter regions of various genes involved in abscisic acid (ABA)-related reactive oxygen species (ROS) equilibrium pathways, including the pentatricopeptide repeat domain gene PPR (LOC_Os07g28900) and the homeobox domain gene homeobox (LOC_Os01g19694). Indeed, PRR expression was inhibited in heat-sensitive rice strains, and the methylation rates of the cytosines in the promoter region of PRR were greater in heat-sensitive strains as compared to heat-tolerant strains.
After HNT exposure, cytosines in the CHH context were more likely than cytosines in other contexts to be methylated differently between the heat-sensitive and heat-tolerant rice strains. Methylation in the promoter regions of the genes associated with ABA-related oxidation and ROS scavenging improved heat tolerance in rice. Our results help to clarify the molecular mechanisms underlying rice heat tolerance.
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