ABSTRACT
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.
ABSTRACT
Objective To improve the quality standard of Tongluo-Zhujing pills.Methods We added the identification ofradix notoginseng andtypha orientalisby TLC and determination of the content of wedelolactone by HPLC. The study used Agilent ZORBAX SB-C18 (4.6 mm × 250 mm, 5 μm) column and the velocity of flow manufactured by the proper proportion was 1 ml/min. The detection wavelength was 249 nm . Results The new method could well identify radix notoginsengandtypha orientalis. The calibration curves of wedelolactone was in good linearity over the range of 0.064-0.642 μg (r=0.999 7) and the average recovery was 98.74%(RSD=1.61%).Conclusions The quality standard of Tongluo-Zhujing pills was proved effectively.
ABSTRACT
Objective To evaluate the effects of different depths of anesthesia with sevoflurane on cerebrovascular autoregulation in infants.Methods Twenty pediatric patients,of ASA physical status Ⅰ,aged 1-3 yr,undergoing elective hypospadias plasty surgery,were enrolled in the study.Single tube laryngeal mask was inserted after anesthesia was induced with 6％ sevoflurane inhalation.Caudal block was performed with 1 ml/kg of 0.2％ ropivacaine.Anesthesia was maintained with sevoflurane inhalation.The end-tidal sevoflurane concentration was adjusted to 1.8％,2.5％,3.3％ and 4.0％,and each concentration was maintained at this level for 15 min.The cerebral blood flow was collected from the middle cerebral artery immediately before adjusting the next concentration to record the Doppler spectrum and transient hyperemic response ratio (THRR) was measured.Results THRR at different depths of anesthesia with sevoflurane was larger than 1.09,and was within the normal range.THRR was significantly lower when the end-tidal concentration was 2.5％,3.3％ and 4.0％ than that obtained when end-tidal concentration was 1.8％.No significantdifference was detected in THRR between 2.5％ and 3.3 ％.THRR was significantly lower when the end-tidal concentration was 4.0 ％ than that obtained when the end-tidal concentration was 2.5％ and 3.3％.Conclusion Although the inhibitory effect on cerebrovascular autoregulation provided by sevoflurane anesthesia provides no obvious clinical significance,it shows statistical significance in infants.
ABSTRACT
This study was aimed to explore the function of c-Jun N-terminal kinase (JNK) signaling pathway in the induction of brain ischemic tolerance, and observe the function of Shu-Xue Tong-Mai (SXTM) capsule pretreatment. Ischemic preconditioning was performed for 3 min on rats to induce cerebral ischemic tolerance. Rat model of cere-bral ischemia reperfusion (the ischemia pretreatment group, I/R group) was established 24 h later. Western blot was used to detect the protein expression of JNK and phosphorylation of c-Jun N-terminal kinase (P-JNK), comparing to the expression with the sham operation group, I/R group and SXTM capsule group. Tunel method was applied to de-tect the apoptosis of neurons. Relationship between expression of JNK, P-JNK and apoptosis of neurons was also studied. The results showed that compared with the model group, expressions of P-JNK in ischemia preconditioning group and SXTM group were declined significantly (P < 0.05); and the apoptosis of neurons quantity was also de-clined (P< 0.05). It was concluded that ischemia preconditioning can decrease the apoptosis of neurons in cerebral ischemia reperfusion, and improve neurologic function. Its mechanism related to the inhibition of JNK signaling path-way. SXTM capsule pretreatment can protect the cerebral by inhibiting the JNK signaling pathway.
ABSTRACT
This study was aimed to evaluate effects of different production techniques of Shuxue Tongmai (SXTM) capsules for blood coagulation function and thrombosis formation among mice. The observation was made on the clot-ting time, bleeding time and instauration rate of collagen-adrenaline model of mice. The results showed that com-pared with SXTM II and Ⅲ production technique, the SXTM I production technique of the same dosage group can prolong the clotting time of mice significantly (P < 0.05), and increase the instauration rate of collagen-adrenaline model of mice significantly (P< 0.05). There was no significant difference on the bleeding time of mice between the SXTM I production technique of same dosage group and the saline group. It was concluded that the SXTM had an-ticoagulative and antithrombotic effects. And the SXTM I production technique receives better effects.
ABSTRACT
ObjectiveTo investigate the effect of focal ischemic preconditioning (IPC) on the expression of protein kinase-like endoplasmic reticulum kinase ( PERK ) and glucose-regulated protein 78 (GRP78) mRNA and protein after focal cerebral ischemia/reperfusion (I/R) in rats.MethodsAll 120 male SD rats were randomly divided into three groups: sham-operation group,middle cerebral artery occlusion (MCAO) group and brain ischemia preconditioning (BIP) group.Each group was further divided into 4 subgroups according to 12 h,1,2 and 3 d after I/R.The IPC models were made in order to measure the expression of PERK,GRP78 mRNA and protein by in situ hybridization and Western blot,and the apoptosis rate of neuron by flow cytometry. Results ①The expression of PERK mRNA increased and reached the peak at 12 h,then decreased continuously after 1 d.BIP could decrease its expression.The expression of PERK protein increased at 12 h and reached the peak at 24 h,then decreased continuously after 2 d.BIP could decrease its expression.②The expression both of GRP78 mRNA and its protein all increased and reached the peak at 12 h,then decreased continuously.BIP could increase their expression (mRNA:12 h: 136.70±9.53,F=32.265; 24 h:147.54 ±9.97,F=54.920; 2 d:158.16 ±9.44,F=45.374; 3d: 165.85±10.26,F=16.493,P＜0.05; protein:12 h: 1.319±0.116,F=5.619,P＜0.05; 24 h: 1.226±0.108,F=33.742,P＜0.01; 2 d:1.183 ±0.112,F =46.556,P ＜0.01; 3 d:1.115± 0.098,F =11.730,P＜0.05).③The rate of apoptosis neuron of rats in MCAO increased markedly at 12 h after reperfusion,and reached the peak at 1 d,then decreased continuously.BIP could decrease the rate of apoptosis neuron. Conclusion BIP can protect neurons through inhibiting the expression of PERK and inducing the expression of GRP78 after endoplasmic reticulum stress in rats.
