1.Resistance mechanisms of blaCTX-M-55 in a clinical Shigella sonnei strain
Xiaoyuan JIANG ; Dong LIU ; Li XU ; Haihong FANG ; Jiao FENG ; Zhe YIN ; Dongsheng ZHOU ; Li WANG ; Defu ZHANG ; Yajun SONG
Military Medical Sciences 2016;40(9):717-721
Objective To characterize the resistance mechanisms of a clinical Shigella sonnei strain harboring blaCTX-M-55 .Methods A double-disk synergy test was conducted to detect ESBL.Antibiotic resistance genes were determined by PCR followed by amplicon sequencing.Conjugation experiments were performed to verify the transferability of the plasmids carrying ESBL genes.The minimum inhibitory concentration values were tested using VITEK 2.The transposition unit was confirmed by DNA sequencer,and the transcriptional start site was identified using primer extension assay.Results Strain #1083 produced CTX-M-55,which was encoded by plasmid p1083-CTXM that could be transferred into E.coli through conjugation experiments to confer corresponding antibiotic resistance to the transconjugant #1083-EC600.The transposition unit mediating the transfer of blaCTX-M-55 was ISEcp1-blaCTX-M-55 -Δorf477.ISEcp1 offered strong promoter regions for the resistance genes,facilitating their expressions.Besides,the expressions were constant,not induced by antibiotics.Conclusion BlaCTX-M-55 on plasmids is the major resistance genes for strain #1083.Their expressions and spread are mediated by the insertion sequence ISEcp1.
2.Application of artificial neural network in evaluation of IVF embryo
Defu ZHOU ; Lian ZOU ; Ying CHEN
Chinese Journal of Laboratory Medicine 2022;45(3):310-314
Artificial neural network (ANN) is a network framework that drives artificial intelligence (AI). Classical convolutional neural networks (CNN) are mainly used for cell count and image recognition at fixed time in embryo evaluation. Fully connected deep neural networks (DNN), with increased accuracy of image recognition, are suitable for the units equipped with high configuration hardware and need comprehensive prediction according to the integrated clinical information. Residual networks improve the accuracy by increasing layers and solving the gradient disappearance problem through jump connection to realize dynamic embryo assessment. Bayesian networks (BN) and multi-layer perceptron (MLP) are two machine learning methods. The former is especially used for comprehensive prediction combined with complex clinical information in case of lack of conditions. The latter has gradient disappearance and explosion problem, and is easy to lose some spatial features of images, so it is used for small sample volumes. ANN has advantages in the prediction of implantation rate and aneuploidy and reducing invasive detection in quality assessment of embryos, which is an important research direction of human-assisted reproductive technology (ART).
3.Effect of hydroxyapatite nanoparticles on MII-stage porcine oocytes vitrification and the study of its mechanism.
Weijie LI ; Xinli ZHOU ; Jiangjun DAI ; Defu ZHANG ; Baolin LIU ; Haisong WANG ; Li XU
Journal of Biomedical Engineering 2013;30(4):789-793
Nano-cryopreservation may become a new way in the next generation of cryopreservation technology. However, research using nanoparticles in oocytes vitrification has not been reported in the literature. In this study, HA nanoparticles with different diameters were added into cryoprotectant and M II-stage porcine oocytes were vitrified by Cryotop. The results showed that nanoparticles improved the survival rate of cryopreserved M II-stage porcine oocytes, but the difference between nanoparticles with different diameters of was not significant. In order to study the mechanism of nano-cryopreservation, the cooling rate of cryoprotectant was measured by ultra-fast temperature measurement system and the melting enthalpy of cryoprotectant was measured by differential scanning calorimeter (DSC). The results showed that the adding of nanoparitcles could not increase the cooling rate of cryoprotectant, but could decreases the amount of ice crystals during freezing and warming. Therefore, the mechanical injury within and outside cells might be effectively reduced.
Animals
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Cell Survival
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physiology
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Cryopreservation
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methods
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veterinary
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Cryoprotective Agents
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pharmacology
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Durapatite
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pharmacology
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Female
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Fertilization in Vitro
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methods
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veterinary
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Metaphase
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Nanoparticles
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Oocytes
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cytology
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Swine
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Vitrification
4.Practice and exploration of training innovative talents through tutorial system in the whole process of "5+3" integrated undergraduate education for clinical medicine specialty
Di JIN ; Guochao SUN ; Jian YIN ; Xueming GU ; Ying YANG ; Defu ZHANG ; You ZHOU ; Youfei GUAN
Chinese Journal of Medical Education Research 2020;19(8):926-929
Dalian Medical University, aiming at cultivating innovative talents, has formulated and implemented a "5+3" innovative talents training reform plan. In the whole process of medical undergraduate education, tutorial system is used as the carrier to develop a phased innovative ability training system, which covers basic scientific research ability training such as courses, lectures, experimental design, papers and so on, and strengthens the cultivation of undergraduate scientific research ability. Through statistical analysis of the results of the first "5+3" students' periodic training, it is found that the proportion of "5+3" students publishing Chinese periodicals and SCI, and hosting national innovation projects and provincial innovation projects is significantly higher than that of ordinary 5-year students ( P<0.05). Although there are some problems and deficiencies in the implementation process, the basic scientific research training with tutorial system as the core has a significant effect on improving students' scientific research thinking and innovation ability, and is feasible for training medical innovative talents.
5.Working memory training improves the executive function and ability in the activities of daily living of stroke survivors
Qingqing ZHOU ; Haoyu LIU ; Defu ZHAO ; Shengjia NIU ; Min SU
Chinese Journal of Physical Medicine and Rehabilitation 2022;44(1):25-29
Objective:To explore any effect of working memory training on executive functioning and ability in the activities of daily living after a stroke.Methods:Forty-six stroke survivors were randomly divided into an experimental group and a control group, each of 23. Both groups received conventional cognitive rehabilitation (including computer-assisted cognition training and virtual reality training using upper limb rehabilitation robots), while the experimental group also received working memory training. Before, as well as after 4 and 8 weeks of the treatment, both groups′ executive functioning was evaluated using the Trail Making test, the Frontal Assessment Battery and the Wisconsin Card Sorting Test-64. Ability in the activities of daily living was quantified using the functional independence measures (FIMs).Results:There were no significant differences between the two groups in any of the measurements before the training. After 4 weeks the average scores of the experimental group on all four instruments were significantly higher than the control group′s averages. After 8 weeks the average scores had improved significantly more. The treatment group performed significantly better than the control group throughout.Conclusions:Working memory training can improve executive functioning and the daily life of stroke survivors.
6.Effect of cryoprotectant removal by microfluidic chip on developmental capacity of oocytes.
Xingyue YI ; Xinli ZHOU ; Yun YANG ; Jianjun DAI ; Defu ZHANG
Journal of Biomedical Engineering 2018;35(1):123-130
In order to reduce osmotic damage and chemical toxicity of cryoprotectants (CPA) to oocytes during unloading process, the microfluidic chip was used to remove CPA from porcine MⅡ oocytes in this study. Firstly, the effects of unloading time, composition and concentration of diluting solutions of microfluidic method on survival rate and developmental capacity of oocytes were studied, then microfluidic method was compared with traditional one-step and two-step CPA unloading protocols. The results showed that when the total time is 8 minutes, the survival rate and morula rate of oocytes treated with microfluidic method could achieve 95.99% ± 4.64% and 74.17% ± 1.18%, respectively, which were not significantly different from fresh control group (98.53% ± 2.94%; 78.22% ± 1.34%). In addition, 1 mol/L sucrose diluting solutions were more beneficial than other solutions, and it was also showed that microfluidic method achieved better survival, cleavage rate of oocytes than traditional methods. Microfluidic CPA removal protocol can reduce the damage to oocytes during unloading process, and may further improve the cryopreservation effect of oocytes.
7.The application scenarios study on the intervention of cognitive decline in elderly population using metaverse technology.
Defu ZHOU ; Yi JIN ; Ying CHEN
Journal of Biomedical Engineering 2023;40(3):573-581
China is facing the peak of an ageing population, and there is an increase in demand for intelligent healthcare services for the elderly. The metaverse, as a new internet social communication space, has shown infinite potential for application. This paper focuses on the application of the metaverse in medicine in the intervention of cognitive decline in the elderly population. The problems in assessment and intervention of cognitive decline in the elderly group were analyzed. The basic data required to construct the metaverse in medicine was introduced. Moreover, it is demonstrated that the elderly users can conduct self-monitoring, experience immersive self-healing and health-care through the metaverse in medicine technology. Furthermore, we proposed that it is feasible that the metaverse in medicine has obvious advantages in prediction and diagnosis, prevention and rehabilitation, as well as assisting patients with cognitive decline. Risks for its application were pointed out as well. The metaverse in medicine technology solves the problem of non-face-to-face social communication for elderly users, which may help to reconstruct the social medical system and service mode for the elderly population.
Aged
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Humans
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Cognitive Dysfunction/prevention & control*
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Aging
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China
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Internet
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Technology