Excessive mechanical strain accelerates intervertebral disc degeneration by disrupting intrinsic circadian rhythm

Ding Sheng-Long,Zhang Tai-Wei,Zhang Qi-Chen,Ding Wang,Li Ze-Fang,Han Guan-Jie,Bai Jin-Song,Li Xi-Lei,Dong Jian,Wang Hui-Ren,Jiang Li-Bo 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

Night shift workers with disordered rhythmic mechanical loading are more prone to intervertebral disc degeneration (IDD). Our results showed that circadian rhythm (CR) was dampened in degenerated and aged NP cells. Long-term environmental CR disruption promoted IDD in rats. Excessive mechanical strain disrupted the CR and inhibited the expression of core clock proteins. The inhibitory effect of mechanical loading on the expression of extracellular matrix genes could be reversed by BMAL1 overexpression in NP cells. The Rho/ROCK pathway was demonstrated to mediate the effect of mechanical stimulation on CR. Prolonged mechanical loading for 12 months affected intrinsic CR genes and induced IDD in a model of upright posture in a normal environment. Unexpectedly, mechanical loading further accelerated the IDD in an Light-Dark (LD) cycle-disrupted environment. These results indicated that intrinsic CR disruption might be a mechanism involved in overloading-induced IDD and a potential drug target for night shift workers.

Constructs of Sequence Pairs with Optimal Three-level Autocorrelation

Jin Hui-long,Zhang Miao,Qi Shu-li 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.5

The optimal discrete signal are widely used in spread spectrum communication systems, sonar, navigation, code division multiple access systems and other fields. The perfect sequence pair is an extension of the single best signal, so its application is more widely. This paper puts forward new methods of constructing the binary sequence pair of three values and quaternion sequence pair of three values according to the problem of constructing the sequence pairs of three values. This method is that it uses N long cyclotomic pseudo-random sequence and its shift sequences pair to do series connection to constitute a 4 N long binary sequence pair of three values. New sequence pairs of three values is obtained by this method proved to have good balance. The application steps of this method are given and shall be verified by some examples.

Modeling and Simulation of the Magnetic Method for High Voltage Direct Current Inspection Robot

Xian-jin Xu,Cheng-hui Liu,Yu Yan,Hao-da Chen,Lei Fang,Yun-long Wang,Long-hui Wu 한국자기학회 2018 Journal of Magnetics Vol.23 No.3

In order to solve the slipping problem of a two-arm-wheel combined inspection robot, a maglev system based on the magnetic field of a high voltage direct current (HVDC) is proposed. The magnetic system comprises of two parts: a magnetic levitation system and a magnetic drive system. The levitation component overcomes the gravity of the robot by the Ampere force generated by current-carrying coils in the magnetic field of HVDC. The drive component utilizes the Ampere force generated by current-carrying coils in the magnetic field of HVDC as the driving force. Simulation results of the model are compared with the calculated values. The results show that the magnetic levitation method and the magnetic drive method are theoretically feasible, and the model is accurate and effective, which is of great practical significance to the physical realization of the inspection robot.

L-carnitine treatment attenuates renal tubulointerstitial fibrosis induced by unilateral ureteral obstruction

( Hai Yan Zhao ),( Hui Ying Li ),( Jian Jin ),( Ji Zhe Jin ),( Long Ye Zhang ),( Mei Ying Xuan ),( Xue Mei Jin ),( Yu Ji Jiang ),( Hai Lan Zheng ),( Ying Shun Jin ),( Yong Jie Jin ),( Bum Soon Choi ) 대한내과학회 2021 The Korean Journal of Internal Medicine Vol.36 No.0

Background/Aims: Accumulating evidence indicates that L-carnitine (LC) protects against multiorgan damage through its antioxidant properties and preservation of the mitochondria. Little information is available about the effects of LC on renal fibrosis. This study examined whether LC treatment would provide renoprotection in a rat model of unilateral ureteral obstruction (UUO) and in vitro. Methods: Sprague-Dawley rats that underwent UUO were treated daily with LC for 7 or 14 days. The influence of LC on renal injury caused by UUO was evaluated by histopathology, and analysis of gene expression, oxidative stress, mitochondrial function, programmed cell death, and phosphatidylinositol 3-kinase (PI3K)/ AKT/forkhead box protein O 1a (FoxO1a) signaling. In addition, H₂O₂-exposed human kidney cells (HK-2) were treated with LC. Results: LC treatment inhibited expression of proinflammatory and profibrotic cytokines, and was followed by a significant attenuation of tubulointerstitial inflammation and fibrosis. The increased oxidative stress caused by UUO was associated with mitochondrial dysfunction and excessive apoptosis and autophagy via PI3K/AKT/FoxO1a-dependent signaling, and this was abrogated by administration of LC. In H₂O₂-exposed HK-2 cells, LC decreased intracellular production of reactive oxygen species, and suppressed expression of profibrotic cytokines and reduced the number of apoptotic cells. Conclusions: LC protects against the progression of tubulointerstitial fibrosis in an obstructed kidney.

A review: synthesis and applications of graphene/chitosan nanocomposites

Hui Yuan,Long-Yue Meng,Soo-Jin Park 한국탄소학회 2016 Carbon Letters Vol.17 No.-

Recently, with continuous developments in the field of materials science, graphene oxide (GO) has emerged as a promising material with excellent electrical, thermal, mechanical, and optical properties, which play important roles in most fields. Researchers have achieved considerable progress with graphene. Chitosan (CS) is a natural polymer that has been studied intensively owing to its specific formation, high chemical resistance, and excellent physical properties. These outstanding properties have led to its universal use in applications such as textile fabrics, tissue engineering, medicine and health, coatings, and paints. By combining the advantages of GO and CS, different types of promising materials can be obtained. This review discusses the preparation of GO-CS fibers, hydrogel and aerogel, and the applications of GO-CS nanocomposites. In addition, directions for future research on graphene material composites are discussed.

Effect of the SBA-15 template and KOH activation method on CO2 adsorption by N-doped polypyrrole-based porous carbons

Hui Yuan,Biao Jin,Long-Yue Meng 한국탄소학회 2018 Carbon Letters Vol.28 No.-

Nitrogen-doped carbons have attracted much attention due to their novel application in relation to gas storage. In this study, nitrogen-doped porous carbons were synthesized using SBA-15 as a template, polypyrrole as the carbon and nitrogen precursor, and KOH as an activating agent. The effect of the activation temperature (600–850°C) on the CO2 adsorption capacity of the obtained porous carbons was studied. Characterization of the resulting carbons showed that they were micro-/meso-porous carbon materials with a well-developed pore structure that varied with the activation temperature. The highest surface area of 1488 m2 g–1 was achieved at an activation temperature of 800°C (AC-800). The nitrogen content of the activated carbon decreased from 4.74 to 1.39 wt% with an increase in the activation temperature from 600 to 850°C. This shows that nitrogen is oxidized and more easily removed than carbon during the activation process, which indicates that C-N bonds are more easily ruptured at higher temperatures. Furthermore, CO2 adsorption isotherms showed that AC-800 exhibited the best CO2 adsorption capacity of 110 mg g–1 at 298 K and 1 bar.

Inhibition of DNA repair protein RAD51 affects porcine preimplantation embryo development

Jin, Zhe-Long,Shen, Xing-Hui,Shuang, Liang,Kwon, Jeong-woo,Seong, Min-Jeong,Kim, Nam-Hyung BioScientifica 2019 Reproduction Vol.157 No.3

<P>Homologous recombination (HR) plays a critical role in facilitating replication fork progression when the polymerase complex encounters a blocking DNA lesion, and it also serves as the primary mechanism for error-free DNA repair of double-stranded breaks. DNA repair protein RAD51 homolog 1 (RAD51) plays a central role in HR. However, the role of RAD51 during porcine early embryo development is unknown. In the present study, we examined whether RAD51 is involved in the regulation of early embryonic development of porcine parthenotes. We found that inhibition of RAD51 delayed cleavage and ceased development before the blastocyst stage. Disrupting RAD51 activity with RNAi or an inhibitor induces sustained DNA damage, as demonstrated by the formation of distinct γH2AX foci in nuclei of four-cell embryos. Inhibiting RAD51 triggers a DNA damage checkpoint by activating the ataxia telangiectasia mutated (ATM)-p53-p21 pathway. Furthermore, RAD51 inhibition caused apoptosis, reactive oxygen species accumulation, abnormal mitochondrial distribution and decreased pluripotent gene expression in blastocysts. Thus, our results indicate that RAD51 is required for proper porcine parthenogenetic activation (PA) embryo development.</P>

KOH-activated graphite nanofibers as CO2 adsorbents

Hui Yuan,Long-Yue Meng,Soo-Jin Park 한국탄소학회 2016 Carbon Letters Vol.19 No.-

Porous carbons have attracted much attention for their novel application in gas storage. In this study, porous graphite nano-fiber (PGNFs)-based graphite nano fibers (GNFs) were prepared by KOH activation to act as adsorbents. The GNFs were activated with KOH by changing the GNF/KOH weight ratio from 0 through 5 at 900°C. The effects of the GNF/ KOH weight ratios on the pore structures were also addressed with scanning electron microscope and N2 adsorption/desorption measurements. We found that the activated GNFs exhibited a gradual increase of CO2 adsorption capacity at CK-3 and then decreased to CK-5, as determined by CO2 adsorption isotherms. CK-3 had the narrowest micropore size distribution (0.6–0.78 nm) among the treated GNFs. Therefore, KOH activation was not only a significant method for developing a suitable pore-size distribution for gas adsorption, but also increased CO2 adsorption capacity as well. The study indicated that the sample prepared with a weight ratio of ‘3’ showed the best CO2 adsorption capacity (70.8 mg/g) as determined by CO2 adsorption isotherms at 298 K and 1 bar.

Heavy concrete shielding properties for carbon therapy

Jin-Long Wang,Jiade J Lu,Da-Jun Ding,Wen-Hua Jiang,Ya-Dong Li,Rui Qiu,Hui Zhang,Xiao-Zhong Wang,Huo-Sheng Ruan,Yan-Bing Teng,Xiao-Guang Wu,Yun Zheng,Zi-Hao Zhao,Kai-Zhong Liao,Huan-Cheng Mai,Xiao-Dong Korean Nuclear Society 2023 Nuclear Engineering and Technology Vol.55 No.6

As medical facilities are usually built at urban areas, special concrete aggregates and evaluation methods are needed to optimize the design of concrete walls by balancing density, thickness, material composition, cost, and other factors. Carbon treatment rooms require a high radiation shielding requirement, as the neutron yield from carbon therapy is much higher than the neutron yield of protons. In this case study, the maximum carbon energy is 430 MeV/u and the maximum current is 0.27 nA from a hybrid particle therapy system. Hospital or facility construction should consider this requirement to design a special heavy concrete. In this work, magnetite is adopted as the major aggregate. Density is determined mainly by the major aggregate content of magnetite, and a heavy concrete test block was constructed for structural tests. The compressive strength is 35.7 MPa. The density ranges from 3.65 g/cm³ to 4.14 g/cm³, and the iron mass content ranges from 53.78% to 60.38% from the 12 cored sample measurements. It was found that there is a linear relationship between density and iron content, and mixing impurities should be the major reason leading to the nonuniform element and density distribution. The effect of this nonuniformity on radiation shielding properties for a carbon treatment room is investigated by three groups of Monte Carlo simulations. Higher density dominates to reduce shielding thickness. However, a higher content of high-Z elements will weaken the shielding strength, especially at a lower dose rate threshold and vice versa. The weakened side effect of a high iron content on the shielding property is obvious at 2.5 µSv=h. Therefore, we should not blindly pursue high Z content in engineering. If the thickness is constrained to 2 m, then the density can be reduced to 3.3 g/cm³, which will save cost by reducing the magnetite composition with 50.44% iron content. If a higher density of 3.9 g/cm³ with 57.65% iron content is selected for construction, then the thickness of the wall can be reduced to 174.2 cm, which will save space for equipment installation.

Value of contrast-enhanced ultrasonography in microwave ablation treatment of symptomatic focal uterine adenomyosis

Xiao-Long Li,Jia-Xin Li,Song-Yuan Yu,Pei-Li Fan,Yun-Jie Jin,Er-Jiao Xu,Sai-Nan Guan,Er-Ya Deng,Qiu-Yan Li,Zheng-Biao Ji,Jiu-Ling Qi,Hui-Xiong Xu,China Alliance of Multi-Center Clinical Study for Ultra 대한초음파의학회 2024 ULTRASONOGRAPHY Vol.43 No.1

Purpose: This study evaluated the value of contrast-enhanced ultrasonography (CEUS) in the ultrasound-guided microwave ablation (MWA) treatment of symptomatic focal uterine adenomyosis.Methods: This retrospective study was conducted between March 2020 and January 2023, enrolling 52 patients with symptomatic focal uterine adenomyosis who had undergone MWA. All patients were examined with CEUS before and after MWA. The non-perfused volume (NPV) was compared between CEUS and dynamic contrast-enhanced magnetic resonance imaging (DCEMRI) following ablation. Therapeutic efficacy and safety were evaluated at 3-, 6-, and 12-month follow-ups. Additionally, this study explored the correlations between pre-treatment CEUS features and a volume reduction ratio indicating sufficient ablation, defined as 50% or more at the 3-month follow-up.Results: No significant differences in NPV were noted between CEUS and DCE-MRI immediately after MWA and during follow-up (all P>0.05). At the 3-month follow-up, the median VRRs for the uterus and adenomyosis were 33.2% and 63.9%, respectively. Sufficient ablation was achieved in 69.2% (36/52) of adenomyosis cases, while partial ablation was observed in the remaining 30.8% (16/52). The identification of non-enhancing areas on pre-treatment CEUS was associated with sufficient ablation (P=0.016). At the 12-month follow-up, significant decreases were observed in both the uterine and adenomyosis volumes (all P<0.001). Dysmenorrhea and menorrhagia were significantly alleviated at 12 months, and no major complications were encountered.Conclusion: CEUS can be used to evaluate the ablation zone of focal adenomyosis that has been treated with MWA, similarly to DCE-MRI. The identification of non-enhancing areas on pretreatment CEUS indicates satisfactory treatment outcomes. Purpose: This study evaluated the value of contrast-enhanced ultrasonography (CEUS) in the ultrasound-guided microwave ablation (MWA) treatment of symptomatic focal uterine adenomyosis. Methods: This retrospective study was conducted between March 2020 and January 2023, enrolling 52 patients with symptomatic focal uterine adenomyosis who had undergone MWA. All patients were examined with CEUS before and after MWA. The non-perfused volume (NPV) was compared between CEUS and dynamic contrast-enhanced magnetic resonance imaging (DCE- MRI) following ablation. Therapeutic efficacy and safety were evaluated at 3-, 6-, and 12-month follow-ups. Additionally, this study explored the correlations between pre-treatment CEUS features and a volume reduction ratio indicating sufficient ablation, defined as 50% or more at the 3-month follow-up. Results: No significant differences in NPV were noted between CEUS and DCE-MRI immediately after MWA and during follow-up (all P>0.05). At the 3-month follow-up, the median VRRs for the uterus and adenomyosis were 33.2% and 63.9%, respectively. Sufficient ablation was achieved in 69.2% (36/52) of adenomyosis cases, while partial ablation was observed in the remaining 30.8% (16/52). The identification of non-enhancing areas on pre-treatment CEUS was associated with sufficient ablation (P=0.016). At the 12-month follow-up, significant decreases were observed in both the uterine and adenomyosis volumes (all P<0.001). Dysmenorrhea and menorrhagia were significantly alleviated at 12 months, and no major complications were encountered. Conclusion: CEUS can be used to evaluate the ablation zone of focal adenomyosis that has been treated with MWA, similarly to DCE-MRI. The identification of non-enhancing areas on pre- treatment CEUS indicates satisfactory treatment outcomes.