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Oscillations, commonly known as a universal, propagative, and intricate event in the new power system, often give rise to generator tripping and load shedding, not only adversely affecting the power flow limit and the power angle stability but also posing threats to the lines of defense for stability and protection. Traditionally, emphasis has been laid on post-fault oscillation management, an emergency measure to deal with the impact and damage that have already affected the power grid. As such, this paper focuses on an oscillation prediction technique to detect oscillation energy early and intervene proactively to prevent further faults. This technique effectively lessens the damage caused by impacts and disconnects to the power grid. Firstly, this paper proposes the concept of disturbance power density and establishes the correlation between disturbance energy and the time domain, thereby exploring a method for evaluating the pattern of electrical quantities before power system oscillation. Secondly, it speeds up the time it takes to detect faults by catching nuances of voltage-current phase angle and impedance. Lastly, it puts forward a technique to cope with the intricacy and variety of power grid equipment using the convolutional neural network (CNN). This technique incorporates an integrated attention mechanism within a one-dimensional CNN model to capture the implicit mapping between voltage, active power, and reactive power at any time in the power system. This enables the model to self-learn multi-device characteristics and enhances the possibility of using theory in practical ways. Moreover, practical case studies also show that the prediction technique proposed in this paper can effectively issue warnings eight minutes before the occurrence of oscillation.
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OBJECTIVE：To study the distri bution and targeting characteristics of Apigenin nanosuspension （AP-NPs）in mice. METHODS：AP-NPs was prepared with ultrasound microprecipitation. Kunming mice were randomly divided into apigenin （AP） solution group and AP-NPs suspension group ，with 45 mice in each group. The mice were given relevant medicine intragastrically （80 mg/kg）；blood sample of eyeball 500 μL were collected before medication（0 h）and 0.25，0.5，1，2，4，6，8，10 h after medication. After the last blood collection ，the mice were sacrificed and their heart ，liver，spleen，lung，kidney and brain tissues were taken. After protein precipitation with methanol ，HPLC method was adopted for determining plasma and tissues. The determination was performed on Shimadzu ODS-SP column with mobile phase consisted of methanol-water （70 ∶ 30，V/V）at the flow rate of 1.0 mL/min. The detection wavelength was set at 340 nm，and column temperature was 35 ℃. The sample size was 20 μL. The concentration of AP in different samples was calculated according to standard curve，main pharmacokinetic parameters （AUC，cmax）of AP and the ratio of peak concentration （ce），relative uptake rate （RUE），uptake ratio and its change value were calculated with DAS 2.0 software and Excel 2010 software；the tissue distribution and targeting characteristics of AP were analyzed. RESULTS：The linear range of AP in plasma and tissue s were 0.1-25.0 μg/mL（all r＞0.99）；the lower limits of quantification were 0.1 μg/mL. RSDs of intra-day and inter-day were all lower than 15％，and the accuracy were 94.37％-117.48％. The extraction recovery rates were all more than 80％. Compared with AP solution group ，the concentrations of AP in plasma sample （during 0.5-6 h），liver tissue （during 0.25-8 h），spleen tissue （during 0.25-8 h）and cerebral tissue （during 0.25-4 h）were increased significantly in AP-NPs suspension group （P＜0.05 or P＜0.01），and the highest in liver tissue. The concentrations of AP in heart tiusse （6 h），liver tissue （10 h），lung tissue （0.5 h），spleen tissue （during 0.25-10 h）were decreased significantly （P＜ 0.05 or P＜0.01）. There was statistical significance in AUC and cmax of AP in plasma and tissue samples between 2 groups（P＜ 0.05）. The ce，RUE，uptake ratio and its change value of liver tissue were the highest ，being 1.34±0.40，1.99±0.29，48.49％ and 15.71％ . CONCLUSIONS ：After AP is made into nanosus- pension，the distribution of drug tissue is changed ，especially targeting effect on liver tissue is improved.
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OBJECTIVE： To prepare Ursolic acid （UA）/Pluronic F127 （PF127）/TPGS-doxorubicin （DOX） mixed nanomicelles， and to characterize it and study its in vitro release behavior. METHODS： UA/PF127/TPGS nanomicelles were prepared by thin film hydration method. Using encapsulation efficiency of UA as index， combined with the results of single factor tests， L9（34） orthogonal test was used to optimize drug dosage of UA， molar ratio of PF127 to TPGS， hydration temperature and hydration volume， validation test was performed. On the basis of succinylated TPGS， TPGS-DOX was synthesized and mixed with UA/PF127/TPGS to prepare UA/PF127/TPGS-DOX mixed nanomicelles， the appearance， particle size and critical micelle concentration （PF127/TPGS） were investigated. The drug release behavior was examined by dialysis bag diffusion method. RESULTS： The optimal preparation technology of UA/PF127/TPGS nanomicelles was as follows as drug dosage of UA 8 mg， molar ratio of PF127 to TPGS 3 ∶ 7， hydration temperature 50 ℃， hydration volume 4 mL. Average encapsulation efficiency of UA in nanomicelles was 89.00％ （RSD＝0.43％， n＝3）. The prepared UA/PF127/TPGS-DOX mixed nanomicelles solution was clear with opalescence. The nanomicelles were spherical and uniform in size； average particle size was （115.00±9.42） nm； critical micelle concentration of PF127/TPGS （molecular ratio 3 ∶ 7） was 0.001 3％. The in vitro drug release of UA and DOX in the mixed nanomicelles was significantly slowed down， compared with raw materials or substance control. The drug release process of the two drugs in the nanomicelles conformed to Weibull equation. CONCLUSIONS： UA/PF127/TPGS-DOX mixed nanomicelles are successfully prepared with uniform particle size， good stability and good sustained-release effect.
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OBJECTIVE： To optimize the preparation technology of Celastrol nanostructured lipid carriers （Cel-NLC）， and to characterize it. METHODS： Cel-NLC was prepared by melt-emulsification ultrasonic method. Based on single factor test， using encapsulation rate of Cel as index， the ratio of liquid lipid （the ratio of total mass）， the amount of compound emulsifier and the dose of main drug were optimized by central composite design-response surface methodology. Validation test was conducted. Zeta potential and particle size of Cel-NLC that prepared by optimal prescription were determined by using granularity and Zeta potential analyzer. The morphology of liposome was observed by TEM. RESULTS： The optimal prescription included that the ratio of liquid lipid was 39％；the amount of compound emulsifier was 196 mg；the dose of main drug was 8 mg. The average encapsulation efficiency of 3 batches of Cel-NLC was 87.22％； average particle size was （41.2±1.1） nm，and average Zeta potential was （－18.4±0.2） mV （n＝3）. It was spherical under electron microscopy. CONCLUSIONS： The optimized technology is simple， stable and feasible， and it is suitable for the preparation of Cel-NLC.
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OBJECTIVE:To study in vivo tissue distribution of genistein-loaded MePEG-PLGA copolymer micelle in mice. METHODS:HPLC method was used to determine the concentrations of genistein in plasma and tissues (heart,liver,spleen, lung, kidney) of mice. The determination was performed on Dikma Diamonsil C18 colunm with mobile phase consisted of methanol-water (60:40,V/V) at the flow rate of 1.0 mL/min. The detection wavelength was set at 260 nm,and the column temperature was 35 ℃. The sample size was 10 μL. 48 mice were divided into emulsion group and micelle group,with 24 mice in each group. They were given 40 mg/kg genistein emulsion or genistein-loaded MePEG-PLGA copolymer micelle via tail vein. The contents of genistein in plasma and tissues (heart,liver,spleen,lung,kidney) were detected 5,30,90 min after medication. AUC0-90 min and mean residence time(MRT)were compared. RESULTS:The content of genistein in micelle group was higher than emulsion group 5,30,90 min after medication,and the content of genistein in liver tissue was lower than emulsion group 5,30 min after medication. Compared with emulsion group,AUC0-90 min and MRT of genistein in plasma of mice in micelle group were increased significantly(P<0.01);AUC0-90 min and MRT of genistein in liver tissue were decreased significantly(P<0.05). AUC0-90 min of genistein in renal tissue was increased significantly (P<0.05),without statistical significance of other differences (P>0.05). CONCLUSIONS:genistein-loaded MePEG-PLGA copolymer micelle can increase the distribution of genistein in plasma,reduce the distribution of it in liver tissue so as to improve therapeutic efficacy and reduce drug hepatotoxicity.
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Objective To enhance the solubility and bioavailability of curcumin (CUR).Methods A novel curcumin nanoparticles were prepared.The CUR-PGD nanoparticles were prepared by the method of ultrasound precipitation combined with high-pressure homogenization using codendrimer PAMAM-co-0.25OEG (PGD) as stabilizer.The stability of CUR-PGD nanoparticles was measured in 0.9% sodium chloride solution,5% glucose, PBS and plasma.Results The drug loading capacity (DL%) of CUR-PGD nanoparticles was 41.2%, the solubility of CUR was increased to 1.5 mg·mL-1 (50 times of CUR bulk powder).The mean diameter of the nanoparticles was 438.0 nm with spherical morphology and the zeta potential was 41.4 mV.The nanoparticles was stable in 0.9% sodium chloride solution,5% glucose, PBS and plasma and there was no hemolytic phenomenon, which meant they were suitable for intravenous administration.The DSC and XRD spectra of CUR-PGD nanoparticles showed that the CUR was presented as crystal morphology in the nanoparticles.The CUR released from nanoparticles was detected in different releasing medium and presented obvious controlled release behavior.Conclusion PGD may be an effective stabilizer for the preparation of CUR-PGD nanoparticles and CUR-PGD nanoparticles are a promising drug delivery system for CUR application in clinic.
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Objective Our previous research demonstrated that trkA and p75 receptors of nerve growth factor(β-NGF) are expressed in human pterygium fibroblasts(HPF), and trkA is expressed only in conjunctiva. The purpose of present study was to investigate the effects of β-NGF on proliferation of HPF and analyse the pathogenesis mechanism of pterygium. Methods The HPF specimen was obtained from Union Hospital of Tongji Medical College, Huazhong University of Science and Technology during the surgery. Explant culture technique was used for the primary culture of HPF tissue. The cells of confluenting 80% were collected and digested using 0. 25% tripsin + 0. 02% EDTA (1:1) and the third to fifth generation of cells were utilized in the experiment. Different concentrations of β-NGF was added in medium. Cultured cells were identified using vimentin, keratin and α-SMA. MTT was used to determine the proliferation of HPF after addition of β-NGF. The expression of trkA and p75 in HPF was detected by immumofluorescence method. Cell proliferation also was semi-quantitatively analyzed by detect of expressions of PCNA protein and mRNA in HPF using Western blot and RT-PCR. Results Cultured HPF cells showed the positive responses for vimentin, α-SMA, trkA and p75 but absent reaction for keratin. MTT revealed that the OD value of HPF cells was gradually enhanced with the increase of β-NGF concentration in 12, 24, 48, 72 and 96 hours after β-NGF action with the maximum stimulation at 48 hours. The expression of PCNA protein and mRNA in HPF was significantly different among various concentrations of β-NGF groups(F_(protein) = 24. 980, P = 0. 000; F_(mRNA) = 64. 490, P = 0. 000) and increased from 5 ng/mL β-NGF group through 50 ng/mL β-NGF group in comparison with 0 and 1 ng/mL β-NGF group (P ＜ 0. 05) . Conclusion The findings demonstrate the potential proliferative effect of β-NGF binding to trkA and p75 on HPF.
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Objective To investigate the solubilitization effect of macromolecular paclitaxel with cyclodextrin and mechanism between inclusion complex and drugs. Methods The influence effects on paclitaxel solubility were studied with ?-cyclodextrin (?-CD) and hydroxypropyl-?-cyclodextrin (HP-?-CD) as inclusion carriers. The chemical shifts of hydrogen atom in host and guest molecules were also investigated with 1H-NMR. Results The form of inclusion complex was responsible by host molecules and the enhancement solubility of paclitaxel in HP-?-CD was larger than that in ?-CD and increased with the ratio increasing. The benzene ring in the molecular of HP-?-CD and paclitaxel showed the most significant effect. Conclusion The solubility of diossolved paclitaxel is improved by hydroxypropyl-?-cyclodextrin.
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Objective To parperare and identify the irisquinone-hydroxypropyl-?-cyclodextrin (irisquinone-HP-?-CD) inclusion compound. The inclusion mechanism and mol ratio of irisquinone and HP-?-CD were studied simultaneously. Methods The irisquinone-HP-?-CD was prepared with lyophilization technique. The mol ratio between host and guest moleculars was also researched by molecular gradient and continuing variational methods in inclusion processing. At the same time, the inclusion compound was identified by X-ray diffraction (XRD) and differential scanning calorimetry (DSC) methods, respectively. Results The above-mentioned systems showed the mol ratio of HP-?-CD-irisquinone (2 : 1) and the inclusion compound enhanced remarkably the most solubilization and more combined constant of irisquinone in 25, 35, and 45℃. The lyophilized powder had been formed inclusion compound by identifying. Conclusion It is advantageous to increase the solubilization and to strengthen the stability of irisquinone by preparing inclusion compound.
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AIM: To prepare the irisquinone freeze-drying injection and investigate its stability. METHODS: The degradation pattern of irisquinone and its effects were measured. At the same time, the stability of freeze-(drying) injection by classic thermostatical test. RESULTS: Irisquinone solution was unstable to heat and its content decreased remarkably in acid and alkaline solutions. The result showed that oil/water partition coeffecient of irisquinone was very large. The irisquinone-hydropropyl1-?-cyclodextrin inclusion complex freeze-drying injection was very effective to enhance the drug stability. CONCLUSION: Irisquinone inclusion complex injection has character of good stability.
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AIM: To screen and optimize the preparation conditions of irisquinone-hydroxypropyl-?-cyclodextrin inclusion complex (Irisquinone-HP-?-CD) with stiring method. METHODS: The load-drug and recovery of irisquinone were adopted as the index, host-guest molar ratio, alcohol concentration and stiring rate as factors, have been investigated in the techniques of irisquinone-HP-?-CD. RESULTS: The load-drug and recovery of irisquinone-HP-?-CD were respective ( 15.79 ?0.22)% and ( 92.03 ?6.26)% by optimizing conditions which were host-guest molar ratio 2∶1, 90% EtOH and stiring rate 800r?min -1. At the same time, the dissolution test showed that irisquinone was faster released from inclusion complex than that from capsules and mixture dosage form. CONCLUSION: The optimizing techniques fit to prepare irisquinoe-HP-?-CD in industry.
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AIM: To study the pharmacokinetics of Paclitaxel Lyophilized Injection and Taxol in rats. METHODS: Paclitaxel inclusion lyophilized Injection was prepared with hydroxylpropyl ? inclusion as the inclusion vehicle. At the same time, Paclitaxel Lyophilized Injection pharmacokinetic pattern and parametes had been modeled with 3p87 program and statistic rules comparing with Taxol. RESULTS: Paclitaxel Lyophilized Inject and Taxol abided by two department model. The parametes T 1/2? (3.40?0.27)h and AUC (34.46?4.34) mg?L -1 ?h,MRT 3.50 h to Lyophilized Injection and T 1/2? (3.50?0.62)h, AUC (25.73?6.42) mg?L -1 ?h,MRT 2.52 h to Taxol. CONCLUSION: The results indicate that distribution rate of the two preparations are in coincidence with in rats and Paclitaxle Lyophilized extends the retention time of paclitaxel in rats.
