1. Rapid analysis of polar components in ophiocordyceps sinensis by conventional liquid chromatography system
Chinese Herbal Medicines 2015;6(3):217-221
Objective: To develop a rapid high-performance liquid chromatography coupled with diode array detection (HPLC-DAD) method for the simultaneous determination of six polar compounds in Ophiocordyceps sinensis. Methods: A poroshell SB Aq column (50 mm × 4.6 mm, 2.7 μm) and gradient elution were used; The detection wavelength of compounds was set at 260 nm. The chromatographic peaks of the six investigated compounds in sample were identified by comparing their retention times with reference compounds. Results: All calibration curves showed good linearity (r > 0.999) within the tested ranges. The intra- and inter-day precisions of the six analytes were less than 0.8% and 2.1%, respectively, and the recoveries of the six analytes were between 95% and 103%. The validated method was successfully applied to the determination of six polar compounds in O. sinensis samples. Conclusion: The poroshell SB Aq column is suitable for the rapid analysis of polar components in Chinese materia medica on conventional HPLC system and the developed HPLC method is also helpful to the quality control of O. sinensis. © 2014 Tianjin Press of Chinese Herbal Medicines.
2. Influence of nitric oxide on growth of microorganisms: A double-edged sword
Academic Journal of Second Military Medical University 2010;31(12):1356-1358
Recently increasing functions of nitric oxide (NO) has been discovered. Researchers around the world have reported that NO plays an important role in the anti-microbial infection; however, more recent studies have found that NO also protect the growth of microorganisms, for example, it can facilitate drug resistance of bacteria and it can protect microorganisms from oxidative stress and pressure. This paper reviews both positive and negative roles of NO on microbial growth and the related mechanisms.
3.Tangeretin inhibits tumor stemness of non-small cell lung cancer by regulating PI3K/AKT/mTOR signaling pathway
Sai WANG ; Lingjie WANG ; Yanli LI ; Peng LI ; Mengjun LI ; Donghua ZHAO ; Yongjie WANG
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2023;30(04):614-621
Objective To study the effect of Tangeretin on non-small cell lung cancer (NSCLC) and the tumor stemness, and to find the molecular mechanism of its effect. Methods We used cell counting and cell cloning experiments to study the effect of Tangeretin on the proliferation of NSCLC cells in vitro. The effect of Tangeretin on the invasion of NSCLC cells was detected by transwell assay. We detected the effect of Tangeretin on the proliferation of NSCLC cells in vivo by nude mouse tumor-bearing experiment. The effect of Tangeretin on tumor stemness of NSCLC cells was detected by self-renew assay, and CD133 and Nanog protein expressions. The expressions of PI3K/AKT/mTOR signaling pathway-related proteins were detected by Western blotting (WB). Results Tangeretin had a good inhibitory effect on the proliferation of NSCLC cells in vivo and in vitro. Cell counting experiment, clonal formation experiment and nude mouse tumor-bearing experiment showed that Tangeretin could inhibit the proliferation activity, clonal formation ability, and tumor size of NSCLC cells in vivo. Self-renew experiments showed that Tangeretin could inhibit the self-renew ability of NSCLC cells. WB experiments showed that Tangeretin inhibited the expressions of tumor stemness markers CD133 and Nanog in NSCLC cells. Tangeretin could inhibit the activation of PI3K/AKT/mTOR signaling pathway-related proteins in NSCLC cells, and the activation of PI3K/AKT/mTOR signaling pathway could partially remit the inhibitory effect of Tangeretin on tumor stemness of NSCLC cells. Conclusion Tangeretin can inhibit the tumor stemness of NSCLC cells, which may be related to the regulation of PI3K/AKT/mTOR signaling pathway.
4. Effects of hydroxyl morpholine resistance on K562 cells of chronic myelocytic leukemia
Chinese Pharmaceutical Journal 2016;51(5):368-372
OBJECTIVE: To investigate the inhibitory activity, induced differentiation-inducing activity and apoptosis-inducingactivity of hydroxyl morpholine (QDML-01) on chronic myelocytic leukemia cells line K562. METHODS: The cell growth curve was drawn based on cell counting method. The IC50 value of QDML-01 and positive control medicine to K562 cells were evaluated by methyl thiazolyl tetrazolium (MTT) assay method. Double soft agar assay method was carried out to study the ability of cell proliferation to determine efficacy of phamacognosy. The pathomorphism was analyed by the Wright-Giemsa staining method. The mechanism of cell apoptosis from morphology and gene level were investigated, by AO-EB double-staining method and DNA breakage test. The effect of QDML-01 on K562 cells from the protein level was determined by Western-blot. RESULTS: The growth curves showed the K562 cells had strong cell vitality. They came into logarithmic phase on the third generation. The MTT assay results showed that the IC50 values of QDML-01 and imatinib to K562 cells were 5. 81 and 596.88 nmol ·L-1. Double soft agar colony formation test showed that clone formed at 21 d and the inhibitory rate of QDML-01 was 81.7%. It indicated that K562 cells were sensitive to QDML-01. Morphology test result showed that QDML-01 induced K562 cells to normal cells. The results of AO-EB double-staining method showed that QDML-01 induced the apoptosis of K562 cells. The study of DNA breakage test indicated that QDML-01 can induce the apoptosis of K562 cells to produce DNA banding with step-like. Western-blot analysis result suggested that QDML-01 can downregulated the expression of P210bcr/abl protein. CONCLUSION: QDML-01 has the inhibitory activity on chronic myelocytic leukemia cells line K562 by promoting the apoptosis of K562 cells and inducing differentiation to normal cells.
5.A review of studies on visual behavior analysis aided diagnosis of autism spectrum disorders.
Journal of Biomedical Engineering 2023;40(4):812-819
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by deficits in social communication and repetitive behaviors. With the rapid development of computer vision, visual behavior analysis aided diagnosis of ASD has got more and more attention. This paper reviews the research on visual behavior analysis aided diagnosis of ASD. First, the core symptoms and clinical diagnostic criteria of ASD are introduced briefly. Secondly, according to clinical diagnostic criteria, the interaction scenes are classified and introduced. Then, the existing relevant datasets are discussed. Finally, we analyze and compare the advantages and disadvantages of visual behavior analysis aided diagnosis methods for ASD in different interactive scenarios. The challenges in this research field are summarized and the prospects of related research are presented to promote the clinical application of visual behavior analysis in ASD diagnosis.
Humans
;
Autism Spectrum Disorder/diagnosis*
;
Vision, Ocular
;
Behavior
6.Research on eye movement data classification using support vector machine with improved whale optimization algorithm.
Yinhong SHEN ; Chang ZHANG ; Lin YANG ; Yuanyuan LI ; Xiujuan ZHENG
Journal of Biomedical Engineering 2023;40(2):335-342
When performing eye movement pattern classification for different tasks, support vector machines are greatly affected by parameters. To address this problem, we propose an algorithm based on the improved whale algorithm to optimize support vector machines to enhance the performance of eye movement data classification. According to the characteristics of eye movement data, this study first extracts 57 features related to fixation and saccade, then uses the ReliefF algorithm for feature selection. To address the problems of low convergence accuracy and easy falling into local minima of the whale algorithm, we introduce inertia weights to balance local search and global search to accelerate the convergence speed of the algorithm and also use the differential variation strategy to increase individual diversity to jump out of local optimum. In this paper, experiments are conducted on eight test functions, and the results show that the improved whale algorithm has the best convergence accuracy and convergence speed. Finally, this paper applies the optimized support vector machine model of the improved whale algorithm to the task of classifying eye movement data in autism, and the experimental results on the public dataset show that the accuracy of the eye movement data classification of this paper is greatly improved compared with that of the traditional support vector machine method. Compared with the standard whale algorithm and other optimization algorithms, the optimized model proposed in this paper has higher recognition accuracy and provides a new idea and method for eye movement pattern recognition. In the future, eye movement data can be obtained by combining it with eye trackers to assist in medical diagnosis.
Animals
;
Support Vector Machine
;
Whales
;
Eye Movements
;
Algorithms
7.Microwave sensor for recognition of abnormal nodule tissue on body surface.
Chunxue LI ; Hongfu GUO ; Chen ZHOU ; Xinran WANG ; Junkai BAI
Journal of Biomedical Engineering 2023;40(1):149-154
For the detection and identification of abnormal nodular tissues on the body surface, a microwave sensor structure loaded with a spiral resonator is proposed in this paper, a sensor simulation model is established using HFSS software, the structural parameters are optimized, and the actual sensor is fabricated. The S21 parameters of the tissue were obtained when nodules appeared by simulation, and the characteristic relationship between the difference of S21 parameters with position was analyzed and tested experimentally. The results showed that when nodules were present in normal tissues, the curve of S21 parameter difference with position change had obvious inverted bimodal characteristics, and the extreme value of S21 parameter difference appeared when the sensor was directly above the nodules, which was easy to identify the position of nodules. It provides an objective detection tool for the identification of abnormal nodular tissues on the body surface.
Microwaves
;
Recognition, Psychology
;
Computer Simulation
;
Software
8.Motor imagery electroencephalogram classification based on sparse spatiotemporal decomposition and channel attention.
Hongli LI ; Feichao YIN ; Ronghua ZHANG ; Xin MA ; Hongyu CHEN
Journal of Biomedical Engineering 2022;39(3):488-497
Motor imagery electroencephalogram (EEG) signals are non-stationary time series with a low signal-to-noise ratio. Therefore, the single-channel EEG analysis method is difficult to effectively describe the interaction characteristics between multi-channel signals. This paper proposed a deep learning network model based on the multi-channel attention mechanism. First, we performed time-frequency sparse decomposition on the pre-processed data, which enhanced the difference of time-frequency characteristics of EEG signals. Then we used the attention module to map the data in time and space so that the model could make full use of the data characteristics of different channels of EEG signals. Finally, the improved time-convolution network (TCN) was used for feature fusion and classification. The BCI competition IV-2a data set was used to verify the proposed algorithm. The experimental results showed that the proposed algorithm could effectively improve the classification accuracy of motor imagination EEG signals, which achieved an average accuracy of 83.03% for 9 subjects. Compared with the existing methods, the classification accuracy of EEG signals was improved. With the enhanced difference features between different motor imagery EEG data, the proposed method is important for the study of improving classifier performance.
Algorithms
;
Brain-Computer Interfaces
;
Electroencephalography/methods*
;
Humans
;
Imagery, Psychotherapy
;
Imagination
9.Research on injection flow velocity planning method for embolic agent injection system.
Jiasheng LI ; Dongcheng REN ; Bo ZHOU ; Shijie GUO ; Baolei GUO
Journal of Biomedical Engineering 2022;39(3):579-585
Interventional embolization therapy is widely used for procedures such as targeted tumour therapy, anti-organ hyperactivity and haemostasis. During embolic agent injection, doctors need to work under X-ray irradiation environment. Moreover, embolic agent injection is largely dependent on doctors' experience and feelings, and over-injection of embolic agent can lead to reflux, causing ectopic embolism and serious complications. As an effective way to reduce radiation exposure and improve the success rate of interventional embolization therapy, embolic agent injection robot is highly anticipated, but how to decide the injection flow velocity of embolic agent is a problem that remains to be solved. On the basis of fluid dynamics simulation and experiment, we established an arterial pressure-injection flow velocity boundary curve model that can avoid reflux, which provides a design basis for the control of embolic agent injection system. An in vitro experimental platform for injection system was built and validation experiments were conducted. The results showed that the embolic agent injection flow speed curve designed under the guidance of the critical flow speed curve model of reflux could effectively avoid the embolic agent reflux and shorten the embolic agent injection time. Exceeding the flow speed limit of the model would lead to the risk of embolization of normal blood vessels. This paper confirms the validity of designing the embolic agent injection flow speed based on the critical flow speed curve model of reflux, which can achieve rapid injection of embolic agent while avoiding reflux, and provide a basis for the design of the embolic agent injection robot.
Embolization, Therapeutic/methods*
10.An optical parameter imaging system with profile information fusion.
Tongxin LI ; Yeqing DONG ; Ming LIU ; Jing ZHAO ; Minghui LI ; Yanzhe LI
Journal of Biomedical Engineering 2022;39(2):370-379
There is a shared problem in current optical imaging technologies of how to obtain the optical parameters of biological tissues with complex profiles. In this work, an imaging system for obtaining the optical parameters of biological tissues with complex profile was presented. Firstly, Fourier transformation profilometry was used for obtaining the profile information of biological tissues, and then the difference of incident light intensity at different positions on biological tissue surface was corrected with the laws of illumination, and lastly the optical parameters of biological tissues were achieved with the spatial frequency domain imaging technique. Experimental results indicated the proposed imaging system could obtain the profile information and the optical parameters of biological tissues accurately and quickly. For the slab phantoms with height variation less than 30 mm and angle variation less than 40º, the maximum relative errors of the profile uncorrected optical parameters were 46.27% and 72.18%, while the maximum relative errors of the profile corrected optical parameters were 6.89% and 10.26%. Imaging experiments of a face-like phantom and a human's prefrontal lobe were performed respectively, which demonstrated the proposed imaging system possesses clinical application value for the achievement of the optical parameters of biological tissues with complex profiles. Besides, the proposed profile corrected method can be used to combine with the current optical imaging technologies to reduce the influence of the profile information of biological tissues on imaging quality.
Diagnostic Imaging
;
Humans
;
Light
;
Optical Imaging
;
Phantoms, Imaging