1.Improved extraction of solanesol from tobacco waste by enzymatic cell wall breaking.
Xingmin WANG ; Yuwen ZHANG ; Guizhi ZHANG ; Zhongyi YIN
Chinese Journal of Biotechnology 2013;29(11):1706-1710
To improve the extraction of solanesol from tobacco waste, we developed an enzymatic cell wall-breaking process with combined cellulase and ligninase. The effects of reaction time, temperature, pH and enzyme/substrate ratio were determined. The results show that the catalytic effect was better than either single enzyme when the ratio of cellulase to ligninase was 15:1 (U/U). Under the optimized conditions of 175 U/g (enzymes/substrate), tobacco to water 1:5 (W/W), temperature 40 degrees C and pH 6.0, the concentration of solanesol in the solution could reach 0.33 g/L after 8 h. And the average leaching rate reached 96.53% which was 1.68 times of the extraction methods of chemical reflux. It provides new way for the extraction of solanesol from tobacco waste, and worthwhile to be further explored.
Cell Wall
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metabolism
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Cellulase
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metabolism
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Oxygenases
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metabolism
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Plant Leaves
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chemistry
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Terpenes
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isolation & purification
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Tobacco
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chemistry
2.One case report of successful treatment of severe myocarditis mimicking acute myocardial infarction by intra-aortic balloon counterpulsation
Guizhi YIN ; Dadong ZHANG ; Wei HU ; Qiang YU ; Yueguang CHEN ; Jianfeng XU ; Xian JIN ; Jun GU ; Jian DONG ; Dongmei GUI
Journal of Shanghai Jiaotong University(medical Science) 2010;30(1):116-117
An old male patient visited the hospital due to shortness of breath and palpitation for 6 h, with fever 3 days before and pump failure at admission. Having no risk factor of coronary diseases such as hypertension, diabetes mellitus and obesity, with ST-T changes and abnormal Q wave on ECC, the signs were compatible with those of acute anterior wall myocardial infarction, while the characteristics of cardiac biomarkers ( significant increase in Troponin I and creatine kinase's isoform, and normal creatine kinase) were not in accordance with those of acute myocardial infarction. Emergency angiography was performed, which indicated normal coronary artery, normal pulmonary artery and global systolic dysfunction of left ventricle. The diagnosis of acute severe myocarditis was established, and intra-aortic balloon pump (IABP) was employed to provide hemodynamic support. Severe myocarditis mimicking acute myocardial infarction may be fatal, and can be easily misdiagnosed. Careful analysis of clinical manifestations, early diagnostic angiography and possible IABP placement are important for the successful treatment.
3.Effects of tirofiban application time on middle-term clinical prognesis in patients with acute ST segment elevation myocardial infarction treated by primary percutaneous coronary intervention
Jun GU ; Wei HU ; Hongbing XIAO ; Xiaodi FENG ; Xian JIN ; Qiang YU ; Guizhi YIN ; Ping GUAN ; Chengjun CHEN ; Yueguang CHEN ; Dadong ZHANG
Chinese Journal of Postgraduates of Medicine 2008;31(25):20-22
Objective To investigate the effects of tirofiban application time on middle-term clinical prognosis in patients with acute ST segment elevation myocardial infarction (STEMI)treated by primary percutsneous coronary intervention (PCI). Methods The study of tirofiban was carried out in 50 patients with STEM[in cardiology department from January to December 2006. Twenty-nine patients were randomized to receive tirofiban after PCI for 24 - 36 hours(short time group, STG) and 21 patients for 48 - 72 hours (long time group,LTG). Clinical characteristics, angiography data, main adverse cardiovascular events (MACE) and coronary restenosis rate in 6-month follow-up of the two groups were. compared. Results Follow-up data showed that there was less intractable angina pectoris (14.3% vs 24.1%, P< 0.05) in LTG. But there was no significant difference in coronary restenosis rate between two groups. Conclusion Long time application of tirofiban following PCI in patients with STEMI could improve middle-term clinical prognosis by alleviating the incidence of intractable angina pectoris.
4.Advances in methods and applications of electroencephalogram microstate analysis.
Haili WANG ; Ning YIN ; Guizhi XU
Journal of Biomedical Engineering 2023;40(1):163-170
Electroencephalogram (EEG) is characterized by high temporal resolution, and various EEG analysis methods have developed rapidly in recent years. The EEG microstate analysis method can be used to study the changes of the brain in the millisecond scale, and can also present the distribution of EEG signals in the topological level, thus reflecting the discontinuous and nonlinear characteristics of the whole brain. After more than 30 years of enrichment and improvement, EEG microstate analysis has penetrated into many research fields related to brain science. In this paper, the basic principles of EEG microstate analysis methods are summarized, and the changes of characteristic parameters of microstates, the relationship between microstates and brain functional networks as well as the main advances in the application of microstate feature extraction and classification in brain diseases and brain cognition are systematically described, hoping to provide some references for researchers in this field.
Electroencephalography
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Brain
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Cognition
5.Effectiveness of the artificial intelligence image recognition system in diagnosing endometrial cytopathology
Jing AN ; Panyue YIN ; Bin WANG ; Guizhi SHI ; Dexing ZHONG ; Jianliu WANG ; Qiling LI
Journal of Xi'an Jiaotong University(Medical Sciences) 2024;45(2):343-347
【Objective】 To explore the effectiveness of an image recognition system based on artificial intelligence (AI) in diagnosing benign and malignant endometrial cell clumps. 【Methods】 We selected endometrial cytological specimens from The First Affiliated Hospital of Xi’an Jiaotong University and Xi’an Daxing Hospital from August 2021 to February 2023; histopathology was used as the gold standard. We compared and analyzed the sensitivity, specificity, positive predictive value, negative predictive value, accuracy and diagnostic time of AI image recognition system (AI diagnosis) and professional pathologists’ manual diagnosis (manual diagnosis) of benign and malignant endometrial cell clumps. 【Results】 Among the 126 patients included in the analysis, the overall coincidence rate of AI diagnosis and histological diagnosis was 92.1% (116/126), which was highly consistent with histopathological results (Kappa=0.841). The overall coincidence rate of manual diagnosis and histological diagnosis was 94.4% (119/126), which was highly consistent with histopathological results (Kappa=0.889). There was no statistically significant difference between AI diagnosis and manual diagnosis methods (χ2=0.568, P=0.451). The sensitivity, specificity, positive predictive value, and negative predictive value of AI diagnosis were 91.8%, 92.3%, 91.8%, and 92.3%, respectively. There were 126 cytology sections, each of which required 6.67 minutes for manual diagnosis and 5.00 minutes for AI diagnosis. 【Conclusion】 The AI image recognition system has high diagnostic accuracy, sensitivity and specificity, which is equivalent to the manual diagnosis level of professional pathologists. Therefore, this system has application value in the diagnosis of benign and malignant endometrial cell clumps.
6.Alpha-wave Cerebral Cortex Functional Networks of Magnetic Stimulation on Acupoints of Different Meridians
Ning YIN ; Yangyang DAI ; Guizhi XU
Chinese Journal of Rehabilitation Theory and Practice 2018;24(12):1438-1445
Objective To study the coordination mechanism of brain induced by stimulating on acupoints of different meridians by means of constructing cerebral cortex functional networks reflecting actual brain functional connections. Methods A 128-lead electroencephalogram (EEG) recording and analysis system was used to collect the EEG signals of 14 healthy subjects (eight males and six females) aged 21 to 25 in resting state and magnetic stimulation on the acupuncture points of Guangming (GB37) and Neiguan (PC6) located in different meridians from October to November, 2017. Then EEG sources were localized by group independent component analysis and standard low-resolution brain electromagnetic tomography, and the statistical relationships of EEG components were calculated. Finally, alpha-wave cerebral cortex functional networks were constructed and analyzed based on complex network theory. Results The connections of brain regions associated with movement, vision increased in the stimulation of Guangming acupoint. The brain regions associated with movement, attention and working memory in the stimulation of the Neiguan acupoint were reduced in the network. Some common brain areas were activated and some changes of functional connections were similar. Conclusion The changes in the topological structure of brain networks are basically consistent with the efficacy of the acupuncture point during magnetic stimulation on Guangming and Neiguan of different meridians, however, it causes some similar changes in functional connectivity connections of some brain regions.
7.Effects of magnetic stimulation at different frequencies on neuronal excitability and voltage-gated potassium channels
Xiaonan YIN ; Guizhi XU ; Haijun ZHU ; Rui FU ; Yang LI ; Chong DING
Journal of Biomedical Engineering 2021;38(2):224-231
As a noninvasive neuromodulation technique, transcranial magnetic stimulation (TMS) is widely used in the clinical treatment of neurological and psychiatric diseases, but the mechanism of its action is still unclear. The purpose of this paper is to investigate the effects of different frequencies of magnetic stimulation (MS) on neuronal excitability and voltage-gated potassium channels in the
Action Potentials
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Animals
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Magnetic Phenomena
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Mental Disorders
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Mice
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Neurons
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Patch-Clamp Techniques
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Potassium Channels, Voltage-Gated
8.A research on epilepsy source localization from scalp electroencephalograph based on patient-specific head model and multi-dipole model.
Ruowei QU ; Zhaonan WANG ; Shifeng WANG ; Yao WANG ; Le WANG ; Shaoya YIN ; Junhua GU ; Guizhi XU
Journal of Biomedical Engineering 2023;40(2):272-279
Accurate source localization of the epileptogenic zone (EZ) is the primary condition of surgical removal of EZ. The traditional localization results based on three-dimensional ball model or standard head model may cause errors. This study intended to localize the EZ by using the patient-specific head model and multi-dipole algorithms using spikes during sleep. Then the current density distribution on the cortex was computed and used to construct the phase transfer entropy functional connectivity network between different brain areas to obtain the localization of EZ. The experiment result showed that our improved methods could reach the accuracy of 89.27% and the number of implanted electrodes could be reduced by (19.34 ± 7.15)%. This work can not only improve the accuracy of EZ localization, but also reduce the additional injury and potential risk caused by preoperative examination and surgical operation, and provide a more intuitive and effective reference for neurosurgeons to make surgical plans.
Humans
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Scalp
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Brain Mapping/methods*
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Epilepsy/diagnosis*
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Electroencephalography/methods*
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Brain