Association between Retinal Vascular Geometric Changes and Cognitive Impairment: A Systematic Review and Meta-Analysis

Huiqun Wu,Chendong Wang,Cong Chen,Xiaotao Xu,Yi Zhu,Aimin Sang,Kui Jiang,Jiancheng Dong 대한신경과학회 2020 Journal of Clinical Neurology Vol.16 No.1

Background and Purpose Previous studies have explored the association between retinal vascular changes and cognitive impairment. The retinal vasculature shares some characteristics with the cerebral vasculature, and quantitative changes in it could indicate cognitive impairment. Hence, a comprehensive meta-analysis was performed to clarify the potential relationship between retinal vascular geometric changes and cognitive impairment. Methods Relevant databases were scrupulously and systematically searched for retinal vascular geometric changes including caliber, tortuosity, and fractal dimension (FD), and for cognitive impairment. The Newcastle-Ottawa Scale was used to evaluate the methodological quality of included studies. RevMan was used to perform the meta-analysis and detect publication bias. Sensitivity analyses were also performed. Results Five studies that involved 2,343 subjects were finally included in the meta-analysis. The results showed that there was no significant association between central retinal artery equivalents (Z=1.17) or central retinal venular equivalents (Z=1.74) and cognitive impairment (both p>0.05). Similarly, no significant difference was detected in retinal arteriolar tortuosity (Z=0.91) and venular tortuosity (Z=1.31) (both p>0.05). However, the retinal arteriolar FD (mean difference: -0.03, 95% CI: -0.05, -0.01) and venular FD (mean difference: -0.03, 95% CI: -0.05, -0.02) were associated with cognitive impairment. Conclusions A smaller retinal microvascular FD might be associated with cognitive impairment. Further large-sample and well-controlled original studies are required to confirm the present findings.

A novel vibration isolator for vibrating screen based on magnetorheological damper

Mingzhuang Wu,Fei Chen,Aimin Li,Ziye Chen,Nana Sun 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.10

A vibrating screen is widely used in raw coal screening, but intensive resonance in the startup and shutdown stages shortens the service life of the vibrating screen and generates vibration damage to surrounding buildings. Therefore, we designed a novel vibration isolator based on a magnetorheological damper, aiming to improve the vibration isolation performance of the vibrating screen. The rheological mechanical model of damping force was analyzed based on the Bingham model, and a magnetic circuit was designed according to electromagnetic theory. Then, an experiment was designed to evaluate the vibration isolation performance of the vibration isolator. The results show that the novel vibration isolator, compared with the metal spring ones, reduces the maximum resonance amplitude by 64 % in the resonance region. In addition, the time of passing through the resonance region in startup and shutdown stages is also reduced by 50 % and 60 %, respectively. This study can provide a new method to improve the vibration isolation performance of vibrating screens.

Synthesis of CNx nanocrystals and nanotubes on Co/Ni-covered substrate by nitrogen-atom-beam-assisted pulsed laser ablation

Ning Xu,Aimin Wu,Fuming Li,Hao Lin,Jiada Wu,Peinan Wang,Yuancheng Du,Zhifeng Ying 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.44 No.32

CNx nanocrystals and nanotubes were synthesized on Co/Ni-covered Si(100) wafers using a nitrogen-atom-beam-assisted pulsed laser ablation deposition method. Transimission electron microscopy, X-ray photoelectron spectroscopy and Raman spectroscopy showed that nanometer-sized CNx nanocrystals and nanotubes were contained in the as-deposited lms. The co-catalyzation by the cobalt and nickel in the synthesis process is considered to play an important role in the formation of CNx nanocrystals and nanotubes. The reasons for the formation of CNx nanocrystals and nanotubes have been analyzed.

Differentiation of Streptococcus thermophilus Strains in Commercial Direct Vat Set Yoghurt Starter

Chengjie Ma,Zhengjun Wu,Zhengjun Chen,Zhaoping Du,Kejie Sun,Aimin Ma 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.4

Based on inhibition of acid production, 100individual colonies of Streptococcus thermophilus isolated from commercial Direct Vat Set yoghurt starter DVS-M were typed into 2 groups of sensitive and insensitive to phage ϕ001, which was isolated from the lysis culture of the turbidity test. The ratio between the sensitive and insensitive isolates in DVS-M was calculated at 3:2. Whole-cell protein profile (WCPP) and randomly amplified polymorphic DNA (RAPD) analysis showed that both WCPP and RAPD patterns between sensitive and insensitive isolates were distinct, whereas isolates with the same sensitivity or insensitivity shared common WCPP and RAPD patterns. It suggested that all the sensitive isolates belong to one S. thermophilus strain and all the insensitive isolates belong to another one. This study revealed that DVS-M yoghurt starter consists of 2 S. thermophilus strains with different phage sensitivity.

Growth of Ni/Co-Catalyzed Crystalline CNx Thin Films by Nitrogen-Plasma-Assisted Pulsed Laser Deposition

Li Li,Ning Xu,Aimin Wu,Hao Ling,Jian Sun,Xiaokang Shen 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.46 No.1

Nanocrystalline carbon nitride (CNx) thin ¯lms have been synthesized by nitrogen-plasma-assisted pulsed-laser deposition. Before depositing carbon nitride ¯lm, Ni/Co was deposited on the silicon (100) substrate acting as catalyst. The properties of the deposited ¯lms were studied by several diagnostic techniques. X-ray photoelectron spectroscopy was used for detecting the compo-sition ratio N/C in the ¯lm. From studying Raman spectra under dierent conditions we can ¯nd how glow discharge pressure aects the carbon nitride ¯lm properties. Two stages in this process and nanocrystallites of tens of nanometers embedded in the as-synthesized thin ¯lm can be seen by transmission-electron microscopy. The FTIR spectrum suggests an abundance of C-N bonds and paucity of C´N bonds, which is a favorable chance for the formation of carbon nitride crystallites. The crystalline nature of the ¯lm is detected by X-ray diraction.

Fault diagnosis method of belt conveyor idler based on sound signal

Yahui Zhang,Siyan Li,Aimin Li,Gaoxiang Zhang,Mingzhuang Wu 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.1

Damage to a belt conveyor idler will increase the downtime and maintenance cost, so it is very important to diagnose its fault. At present, the fault diagnosis of the idler of a belt conveyor is mostly based on vibration and temperature signal. However, contact fault diagnosis approaches are severely limited when sensors are inconvenient to install or when vibration and temperature signals cannot be returned. In this special case, the non-contact fault diagnosis method, represented by measuring acoustic signals, becomes a necessary means. To effectively extract mechanical state information from sound signals of belt conveyors and identify typical mechanical faults, we propose a fault detection method based on sample center distance weighted (support vector data description (SVDD)) and multi-frame fusion (Melfrequency cepstral coefficient (MFCC)) features. Aiming at the disadvantage that single frame MFCC features and traditional SVDD are susceptible to noise, multi-frame fusion MFCC optimization features are used as samples, and the weighted SVDD model based on sample center distance is used for fault detection. Finally, the overall recognition accuracy of the experiment is greatly improved. It is proved that MFCC features of multi-frame fusion sound signal and weighted SVDD fault detection based on sample center distance can effectively determine whether there is a fault in the of belt conveyor idler.

A novel water-cooling magnetorheological transmission device

Fei Chen,Xiao Wang,Haopeng Li,Aimin Li,Yongrui Deng,Zuzhi Tian,Xiangfan Wu 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.5

Magnetorheological (MR) fluid in power transmission devices, especially in highpower transmission devices, sometimes works at high temperatures owing to wall slip, particle friction, and exciting current. In such cases, effective heat dissipation is crucial. A novel watercooling structure is proposed to deal with the negative effect of centrifugal force on heat dissipation. The magnetic circuit of the novel MR transmission device is designed on the basis of electromagnetic theory, and the magnetic field is investigated by finite element calculation. Experiments under extreme condition show that the temperature of MR fluid in the device drops sharply from 70 °C to 28 °C, and the heat generated inside the device dissipates instantly. Results show that the novel power transmission device has excellent heat dissipation effect.

Expression and Efficient Purification of Tag-cleaved Active Recombinant Human Insulin-like Growth Factor-II from Escherichia coli

Hongbo Li,Xiaoyan Hui,Peng Li,Aimin Xu,Shiwu Li,Shouguang Jin,Donghai Wu 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.2

Insulin-like growth factor-II (IGF2) is a growth factor for the control of cell proliferation and apoptosis. To explore the clinical use of human IGF2, an efficient method for production of a large amount of active recombinant hIGF2 is necessary. Human IGF2 cDNA was cloned into pET32 vector where it is under the control of an IPTGinducible T7 promoter. High level soluble thioredoxin (Trx)- hIGF2 fusion protein was produced at room temperature following IPTG induction, amounting up to 20% of the total soluble bacterial proteins. The recombinant TrxhIGF2 fusion protein was purified to an approximate 95% purity using Ni+-NTA affinity chromatography with an overall yield of 120 mg protein per liter of bacterial culture. After cleavage of the Trx fusion fragment by recombinant enterokinase, the tag-free recombinant hIGF2 protein (rhIGF2) was purified by passage through the Ni+-NTA affinity column again. Biological activity of the purified hIGF2 was determined by its ability to support NIH/3T3 cells proliferation and to activate AKT signaling pathways. Our results demonstrate that tag-free active rhIGF2 can easily be obtained for various applications from E. coli using the procedure described in this report.

Exercise-induced FNDC5/irisin protects nucleus pulposus cells against senescence and apoptosis by activating autophagy

Zhou Wenxian,Shi Yifeng,Wang Hui,Chen Linjie,Yu Caiyu,Zhang Xufei,Yang Lei,Zhang Xiaolei,Wu Aimin 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Intervertebral disc degeneration (IVDD) is a major cause of low back pain (LBP), and excessive senescence and apoptosis of nucleus pulposus (NP) cells are major pathological changes in IVDD. Physical exercise could effectively delay the process of intervertebral disc degeneration; however, its mechanism is still largely unknown. Irisin is an exercise-induced myokine released upon cleavage of the membrane-bound precursor protein fibronectin type III domain-containing protein 5 (FNDC5), and its levels increase after physical exercise. Here, we show that after physical exercise, FNDC5/irisin levels increase in the circulation and NP, senescence and apoptosis are reduced, autophagy is activated in NP tissue, and the progression of IVDD is delayed. Conversely, after knocking out FNDC5, the benefits of physical exercise are compromised. Moreover, the overexpression of FNDC5 in NP tissue effectively alleviated the degeneration of the intervertebral disc (IVD) in rats. By showing that FNDC5/irisin is an important mediator of the beneficial effects of physical exercise in the IVDD model, the study proposes FNDC5/irisin as a novel agent capable of activating autophagy and protecting NP from senescence and apoptosis.