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Fuzzy Based Interleaved Step-up Converter for Electric Vehicle
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作者 T.Saravanakumar R.Saravana kumar 《Intelligent Automation & Soft Computing》 SCIE 2023年第1期1103-1118,共16页
This work focuses on the fuzzy controller for the proposed three-phase interleaved Step-up converter(ISC).The fuzzy controller for the proposed ISC converters for electric vehicles has been discussed in detail.The pro... This work focuses on the fuzzy controller for the proposed three-phase interleaved Step-up converter(ISC).The fuzzy controller for the proposed ISC converters for electric vehicles has been discussed in detail.The proposed ISC direct current(DC-DC)converter could also be used in automobiles,satellites,industries,and propulsion.To enhance voltage gain,the proposed ISC Converter combines boost converter and interleaved converter(IC).This design also reduces the number of switches.As a result,ISC converter switching losses are reduced.The proposed ISC Converter topology can produce a 143 V output voltage and 1 kW of power.Due to the high voltage gain of this converter design,it is suitable for medium and high-power systems.The proposed ISC Converter topology is simulated in MATLAB/Simulink.The simulated output displays a high output voltage.But the output voltage contains maximum ripples.Fuzzy proposes an ISC Converter which makes closed loop responsiveness and reduces the output voltage ripple.The proposed ISC converter has the lowest ripple output voltage,which is less than 2%,because the duty cycle is regulated using the fuzzy logic controller.It offers high voltage gain,minimal ripple,and low switching loss.The performance of the proposed converter is compared to that of the fuzzy and Pro-portional Integral(PI)controllers implemented in MATLAB. 展开更多
关键词 step-up converter interleaved converter ripple voltage FUZZY electric vehicles
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一种低输入电压、低功率Step-up DC-DC变换器的设计
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作者 门秀萍 《常州工学院学报》 2011年第5期34-35,45,共3页
文章提出一种Step-up DC-DC的变换器的设计方法,效率高达70%,输入电压范围低至500 mV,最小起动电压能够达到300 mV。
关键词 低输入电压 step-up DC-DC 变换器
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One-step laparoscopic pancreatic necrosectomy verse surgical step-up approach for infected pancreatic necrosis:a case-control study 被引量:12
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作者 Sheng-bo Han Ding Chen +6 位作者 Qing-yong Chen Ping Hu Hai Zheng Jin-huang Chen Peng Xu Chun-you Wang Gang Zhao 《World Journal of Emergency Medicine》 SCIE CAS CSCD 2022年第4期274-282,共9页
BACKGROUND:The surgical step-up approach often requires multiple debridements and might not be suitable for infected pancreatic necrosis(IPN)patients with various abscesses or no safe route for percutaneous catheter d... BACKGROUND:The surgical step-up approach often requires multiple debridements and might not be suitable for infected pancreatic necrosis(IPN)patients with various abscesses or no safe route for percutaneous catheter drainage(PCD).This case-control study aimed to investigate the safety and effectiveness of one-step laparoscopic pancreatic necrosectomy(LPN)in treating IPN.METHODS:This case-control study included IPN patients undergoing one-step LPN or surgical step-up in our center from January 2015 to December 2020.The short-term and long-term complications after surgery,length of hospital stay,and postoperative ICU stays in both groups were analyzed.Univariate and multivariate logistic regression analyses were performed to explore the risk factors of major complications or death.RESULTS:A total of 53 IPN patients underwent one-step LPN and 37 IPN patients underwent surgical step-up approach in this study.There was no significant difference in the incidence of death,major complications,new-onset diabetes,or new-onset pancreatic exocrine insufficiency between the two groups.However,the length of hospital stay in the one-step LPN group was significantly shorter than that in the surgical step-up group.Univariate regression analysis showed that the surgical approach(one-step/step-up)was not the risk factor for major complications or death.Multivariate logistic regression analysis indicated that computed tomography(CT)severity index,American Society of Anesthesiologists(ASA)class IV,and white blood cell(WBC)were the significant risk factors for major complications or death.CONCLUSION:One-step LPN is as safe and effective as the surgical step-up approach for treating IPN patients,and reduces total hospital stay. 展开更多
关键词 Infected pancreatic necrosis One-step laparoscopic pancreatic necrosectomy Surgical step-up approach
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Mortality and morbidity in necrotizing pancreatitis managed on principles of step-up approach:7 years experience from a single surgical unit 被引量:12
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作者 Deshpande Aparna Sunil Kumar Shukla Kamalkumar 《World Journal of Gastrointestinal Surgery》 SCIE CAS 2017年第10期200-208,共9页
AIM To determine percentage of patients of necrotizing pancreatitis(NP) requiring intervention and the types of interventions performed. Outcomes of patients of step up necrosectomy to those of direct necrosectomy wer... AIM To determine percentage of patients of necrotizing pancreatitis(NP) requiring intervention and the types of interventions performed. Outcomes of patients of step up necrosectomy to those of direct necrosectomy were compared. Operative mortality, overall mortality, morbidity and overall length of stay were determined. METHODS After institutional ethics committee clearance and waiver of consent, records of patients of pancreatitis were reviewed. After excluding patients as per criteria, epidemiologic and clinical data of patients of NP was noted. Treatment protocol was reviewed. Data of patients in whom stepup approach was used was compared to those in whom it was not used. RESULTS A total of 41 interventions were required in 39% patients. About 60% interventions targeted the pancreatic necrosis while the rest were required to deal with the complications of the necrosis. Image guided percutaneous catheter drainage was done in 9 patients for infected necrosis all of whom required further necrosectomy and in 3 patients with sterile necrosis. Direct retroperitoneal or anterior necrosectomy was performed in 15 patients. The average time to first intervention was 19.6 d in the non step-up group(range 11-36) vs 18.22 d in the Step-up group(range 13-25). The average hospital stay in non step-up group was 33.3 d vs 38 d in step up group. The mortality in the step-up group was 0%(0/9) vs 13%(2/15) in the non step up group. Overall mortality was 10.3% while post-operative mortality was 8.3%. Average hospital stay was 22.25 d.CONCLUSION Early conservative management plays an important role in management of NP. In patients who require intervention, the approach used and the timing of intervention should be based upon the clinical condition and local expertise available. Delaying intervention and use of minimal invasive means when intervention is necessary is desirable. The step-up approach should be used whenever possible. Even when the classical retroperitoneal catheter drainage is not feasible, there should be an attempt to follow principles of step-up technique to buy time. The outcome of patients in the step-up group compared to the non stepup group is comparable in our series. Interventions for bowel diversion, bypass and hemorrhage control should be done at the appropriate times. 展开更多
关键词 Necrotizing pancreatitis Nerosectomy Morbidity and mortality in necrotizing pancreatitis step-up approach
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Controversies in the treatment of Crohn’s disease: The case for an accelerated step-up treatment approach 被引量:4
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作者 Amandeep K Shergill Jonathan P Terdiman 《World Journal of Gastroenterology》 SCIE CAS CSCD 2008年第17期2670-2677,共8页
The ideal treatment strategy for Crohn’s disease (CD) remains uncertain, as does the optimal endpoint of therapy. Top-down versus step-up describes two different approaches: early use of immunomodulators and biologic... The ideal treatment strategy for Crohn’s disease (CD) remains uncertain, as does the optimal endpoint of therapy. Top-down versus step-up describes two different approaches: early use of immunomodulators and biological agents in the former versus initial treatment with steroids in the latter, with escalation to immunomodulators or biological drugs in patients proven to be steroid refractory or steroid dependent. Top-down therapy has been associated with higher rates of mucosal healing. If mucosal healing proves to be associated with better long-term outcomes, such as a decreased need for hospitalization and surgery, top-down therapy may be the better approach for many patients. The main concern with the top-down approach is the toxicity of the immunomodulators and biological agents, which have been linked with infectious complications as well as an increased risk of lymphoma. It is unlikely that one strategy will be best for all patients given the underlying heterogeneity of CD presentation and severity. Ultimately, we must weigh the safety and efficacy of the therapies with the risks of the disease itself. Unfortunately our ability to risk stratify patients at diagnosis remains rudimentary. The purpose of this paper is to review the data that supports or refutes the differing treatment paradigms in CD, and to provide a rationale for an approach, termed the "accelerated step-up" approach, which attempts to balance the risks and benefits of our currently available therapies with the risk of disease related complications as we understand them in 2008. 展开更多
关键词 Crohn's disease TOP-DOWN step-up Anti-tumor necrosis factor antibodies IMMUNOMODULATORS Mucosal healing
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Proton pump inhibitor step-down therapy for GERD:A multi-center study in Japan
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作者 Takao Tsuzuki Hiroyuki Okada +6 位作者 Yoshiro Kawahara Ryuta Takenaka Junichiro Nasu Hidehiko Ishioka Akiko Fujiwara Fumiya Yoshinaga Kazuhide Yamamoto 《World Journal of Gastroenterology》 SCIE CAS CSCD 2011年第11期1480-1487,共8页
AIM:To investigate the predictors of success in stepdown of proton pump inhibitor and to assess the quality of life(QOL).METHODS:Patients who had heartburn twice a week or more were treated with 20 mg omeprazole(OPZ) ... AIM:To investigate the predictors of success in stepdown of proton pump inhibitor and to assess the quality of life(QOL).METHODS:Patients who had heartburn twice a week or more were treated with 20 mg omeprazole(OPZ) once daily for 8 wk as an initial therapy(study 1).Patients whose heartburn decreased to once a week or less at the end of the initial therapy were enrolled in study 2 and treated with 10 mg OPZ as maintenance therapy for an additional 6 mo(study 2).QOL was in-vestigated using the gastrointestinal symptom rating scale(GSRS)before initial therapy,after both 4 and 8 wk of initial therapy,and at 1,2,3,and 6 mo after starting maintenance therapy.RESULTS:In study 1,108 patients were analyzed.Their characteristics were as follows;median age:63(range: 20-88)years,sex:46 women and 62 men.The success rate of the initial therapy was 76%.In the patients with successful initial therapy,abdominal pain,indigestion and reflux GSRS scores were improved.In study 2,83 patients were analyzed.Seventy of 83 patients completed the study 2 protocol.In the per-protocol analysis,80%of 70 patients were successful for stepdown.On multivariate analysis of baseline demographic data and clinical information,no previous treatment for gastroesophageal reflux disease(GERD)[odds ratio (OR)0.255,95%CI:0.06-0.98]and a lower indigestion score in GSRS at the beginning of step-down therapy(OR 0.214,95%CI:0.06-0.73)were found to be the predictors of successful step-down therapy.The improved GSRS scores by initial therapy were maintained through the step-down therapy.CONCLUSION:OPZ was effective for most GERD patients.However,those who have had previous treatment for GERD and experience dyspepsia before stepdown require particular monitoring for relapse. 展开更多
关键词 Gastroesophageal reflux disease Proton pump inhibitor OMEPRAZOLE step-down therapy Gastrointestinal symptom rating scale
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ARRHENIUS ANALYSIS OF SINGLE-HEATED AND STEP-DOWN HEATED V_(79) AND L CELLSIN VITRO
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作者 张珊文 Eiichi Kano 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 1990年第1期33-44,共12页
The response to single heat treatment and Step-down heat (SDH) treatment in vitro of V79 and L cells was studied. Colony-forming ability was assayed in medium after treatment in vitro. Time-response curves were establ... The response to single heat treatment and Step-down heat (SDH) treatment in vitro of V79 and L cells was studied. Colony-forming ability was assayed in medium after treatment in vitro. Time-response curves were established and subjected to Arrhenius analysis. The Arrhenius curves showed inflection points at 43℃ for V79 cells and at 42℃ for L cells. The activation energies were 145 kcal/mole and 400 kcal/mole above and below 43℃ (P<0.05), respectively, for V79 cells, while 160 kcal/mole and 300 kcal/mole above and below 42℃ (P<0.05), respectively, for L cells. Thermosensitivity of L cells are markedly higher than V79 cells. Both V79 and L cells were sensitized by SDH. The SDH effect was characterized by a reduction in shoulder (an addition effect to sublethal damage), an increase in slope (thermosensitization), and the delay and disappearance of thermotolerant 'tail' for V79 and L cells at 45℃ to 40℃ and 44℃ to 42℃ SDH treatment respectively. Particularly, 42℃ to 39℃ or 42℃ to 40℃ SDH for L cells resulted in thermosensitization effect up to a factor of 7.1 or 2.7, respectively. The effect was quantified by thermorsensitization ratio (TSR), defined as T0 single heated/T0SDH-heated. The relative ratio was much higher for V79 than for L cells. Heat killing with SDH characterized by Arrhenius analysis showed that Step-down heating reduced the activation energy for heat killing more than single heating. The decrease of activation energy for L cells was markedly greater than for V79. These data suggest that greater cellular sensitivity under step-down heating conditions may reflect a different mechanism for cell killing. 展开更多
关键词 OC AND L CELLSIN VITRO ARRHENIUS ANALYSIS OF SINGLE-HEATED AND step-down HEATED V
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Step-up approach in emphysematous hepatitis: A case report
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作者 Silke Francois Maridi Aerts +4 位作者 Hendrik Reynaert Ruth Van Lancker Johan Van Laethem Rastislav Kunda Nouredin Messaoudi 《World Journal of Hepatology》 2022年第2期464-470,共7页
BACKGROUND Emphysematous hepatitis(EH)is a rare,rapidly progressive fulminant gasforming infection of the liver parenchyma.It is often fatal and mostly affects diabetes patients.CASE SUMMARY We report a case of EH suc... BACKGROUND Emphysematous hepatitis(EH)is a rare,rapidly progressive fulminant gasforming infection of the liver parenchyma.It is often fatal and mostly affects diabetes patients.CASE SUMMARY We report a case of EH successfully managed by a step-up approach consisting of aggressive hemodynamic support,intravenous antibiotics,and percutaneous drainage,ultimately followed by laparoscopic deroofing.Of 11 documented cases worldwide,only 1 of the patients survived,treated by urgent laparotomy and surgical debridement.CONCLUSION EH is a life-threatening infection.Its high mortality rate makes timely diagnosis essential,in order to navigate treatment accordingly. 展开更多
关键词 Emphysematous hepatitis Septic shock step-up approach Percutaneous drainage Laparoscopic deroofing Case report
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Analysis and Design of Single Switch Hybrid Step-Up Converter
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作者 Ravivarman Shanmugasundaram Jeyabharath Rajaiah Veena Parasunath 《Circuits and Systems》 2016年第4期211-221,共11页
A Single Switch Hybrid Step-up Converter with high voltage gain, which is suitable for renewable energy system, is proposed in this paper. The proposed converter consists of one switched diode-inductor cell and a capa... A Single Switch Hybrid Step-up Converter with high voltage gain, which is suitable for renewable energy system, is proposed in this paper. The proposed converter consists of one switched diode-inductor cell and a capacitor. While switching, both are charged in parallel from the input source and discharged in series to the output. In order to obtain extra voltage gain at lower duty cycle, the voltage multiplier cell is integrated with the proposed converter. The main advantages of the converter are high voltage gain, reduced voltage stress, simple structure and low output voltage ripples. The operating principle and steady state theoretical analysis are presented. A 250 W prototype converter is implemented with 12 V input and 120 V output to verify the design and analysis of this converter and it has an efficiency of over 90% in all operations. 展开更多
关键词 DC-DC Power Conversion Switched-Inductor step-up Converter Voltage Multiplier
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Fundamental Study of High Step-down Non-isolated Multicellular DC-DC Converter for Future DC Distribution Systems
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作者 Yusuke Hayashi Yoshikatsu Matsugaki Tamotsu Ninomiya 《Journal of Energy and Power Engineering》 2017年第9期605-613,共9页
A novel high step-down non-isolated DC-DC converter has been proposed. The proposed converter consists of highly efficient non-isolated cell converters using bidirectional semiconductor power devices, and these cell c... A novel high step-down non-isolated DC-DC converter has been proposed. The proposed converter consists of highly efficient non-isolated cell converters using bidirectional semiconductor power devices, and these cell converters are connected in ISOP (input series and output parallel). The non-isolated ISOP converter achieves high step-down ratio of D/N, operating N cell converters under the duty ratio olD. Availability of the proposed converter has been shown by developing the 48 V-12 V laboratory prototype using two 24 V-12 V cell converters. Design consideration for the 48 V-3 V multicellular converter using four 12 V-3 V cell converters has been also conducted, and the potential to approach the efficiency of 97% has been discussed. The proposed topology is suitable for the POL (point of load) converters in the highly efficient next generation DC distribution system for data centers. 展开更多
关键词 DC-DC converter high step-down ratio ISOP GaN (gallium nitride).
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益智汤对老年性痴呆模型神经元RNA和Nissl体影响的研究 被引量:4
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作者 陈辉扬 刘志承 《现代预防医学》 CAS 北大核心 2005年第8期949-951,共3页
目的:观察益智汤对老年性痴呆模型神经元RNA和Nissl体的影响。方法:从21月龄昆明种小鼠筛选出自发老年性痴呆鼠,随机分为4组即空白对照组、西药对照组、益智汤给药组、另设老年学习记忆正常组(简称老年正常组,下同)。西药对照组给以Hyde... 目的:观察益智汤对老年性痴呆模型神经元RNA和Nissl体的影响。方法:从21月龄昆明种小鼠筛选出自发老年性痴呆鼠,随机分为4组即空白对照组、西药对照组、益智汤给药组、另设老年学习记忆正常组(简称老年正常组,下同)。西药对照组给以Hydergine0.6mg/kg,益智汤给药组给予益智汤6.80g/kg,连续60d,正常对照和痴呆对照组均灌以等量DW;用跳台实验(step-downtest)检测学习记忆成绩;脑组织冰冻切片,细胞化学方法显示大脑皮质和海马神经元内RNA和Nissl体,全自动显微图象分析系统定量检测相关脑区RNA和Nissl体含量。结果:益智汤能明显增高大脑皮质和海马锥体细胞的RNA和Nissl体含量。结论:益智汤可明显改善自发老年性痴呆模型的学习记忆障碍,并促进调节其大脑皮质和海马的RNA代谢,明显改善学习记忆关键脑区的神经元结构,从而发挥神经元营养和保护作用。 展开更多
关键词 老年性痴呆 益智汤 RNA Nissl体 跳台实验(step-down test)
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Management of acute pancreatitis in Japan: analysis of nationwide epidemiological survey 被引量:11
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作者 Shin Hamada Atsushi Masamune Tooru Shimosegawa 《World Journal of Gastroenterology》 SCIE CAS 2016年第28期6335-6344,共10页
Acute pancreatitis(AP) is an acute inflammatory disease of the exocrine pancreas. In Japan, nationwide epidemiological surveys have been conducted every 4 to 5 years by the Research Committee of Intractable Pancreatic... Acute pancreatitis(AP) is an acute inflammatory disease of the exocrine pancreas. In Japan, nationwide epidemiological surveys have been conducted every 4 to 5 years by the Research Committee of Intractable Pancreatic Diseases, under the support of the Ministry of Health, Labour, and Welfare of Japan. We reviewed the results of the nationwide surveys focusing on the severity assessment and changes in the therapeutic strategy for walled-off necrosis. The severity assessment system currently used in Japan consists of 9 prognostic factors and the imaging grade on contrastenhanced computed tomography. By univariate analysis, all of the 9 prognostic factors were associated with AP-related death. A multivariate analysis identified 4 out of the 9 prognostic factors(base excess or shock, renal failure, systemic inflammatory response syndrome criteria, and age) that were associated with AP-related death. Receiver-operating characteristics curve analysis showed that the area under the curve was 0.82 for these 4 prognostic factors and 0.84 for the 9 prognostic factors, suggesting the comparable utility of these 4 factors in the severity assessment. We also examined the temporal changes in treatment strategy for walled-off necrosis in Japan according to the 2003, 2007, and 2011 surveys. Step-up approaches and lessinvasive endoscopic therapies were uncommon in 2003 and 2007, but became popular in 2011. Mortality has been decreasing in patients who require intervention for walled-off necrosis. In conclusion, the nationwide survey revealed the comparable utility of 4 prognostic factors in the severity assessment and the increased use of less-invasive, step-up approaches with improved clinical outcomes in the management of walled-off necrosis. 展开更多
关键词 Endoscopic necrosectomy Diagnostic criteria EPIDEMIOLOGY Pancreatic pseudocyst Systemic inflammatory response syndrome step-up approach Walled-off necrosis
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Lithium chloride ameliorates learning and memory ability and inhibits glycogen synthase kinase-3 beta activity in a mouse model of fragile X syndrome 被引量:3
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作者 Shengqiang Chen Xuegang Luo +6 位作者 Quan Yang Weiwen Sun Kaiyi Cao Xi Chen Yueling Huang Lijun Dai Yonghong Yi 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第31期2452-2459,共8页
In the present study,Fmr1 knockout mice (KO mice) were used as the model for fragile X syndrome.The results of step-through and step-down tests demonstrated that Fmr1 KO mice had shorter latencies and more error cou... In the present study,Fmr1 knockout mice (KO mice) were used as the model for fragile X syndrome.The results of step-through and step-down tests demonstrated that Fmr1 KO mice had shorter latencies and more error counts,indicating a learning and memory disorder.After treatment with 30,60,90,120,or 200 mg/kg lithium chloride,the learning and memory abilities of the Fmr1 KO mice were significantly ameliorated,in particular,the 200 mg/kg lithium chloride treatment had the most significant effect.Western blot analysis showed that lithium chloride significantly enhanced the expression of phosphorylated glycogen synthase kinase 3 beta,an inactive form of glycogen synthase kinase 3 beta,in the cerebral cortex and hippocampus of the Fmr1 KO mice.These results indicated that lithium chloride improved learning and memory in the Fmr1 KO mice,possibly by inhibiting glycogen synthase kinase 3 beta activity. 展开更多
关键词 fragile X syndrome Fmr1 knockout mice step-down test step-through test learning and memory glycogen synthase kinase 3 beta lithium chloride
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Measurement-based approach for identification of static load model of electric power system
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作者 翰林 赵峰 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2016年第3期214-220,共7页
The validity of electric power system simulation or prediction models depends on static load model. Measurement- based approach is the unique method to identify them adequately. The measured power depends on both load... The validity of electric power system simulation or prediction models depends on static load model. Measurement- based approach is the unique method to identify them adequately. The measured power depends on both load reaction to supply voltage alteration and random process of load alteration Basically, there is no any universal method that can single out the inherent static load model from experimental data. The paper offers a proprietary technique which is the particular solution of the task. The technique considers the selection of neighboring measurement pairs with the supply voltage altering significantly be-tween them, the exclusion of selected pairs by load power factor and subsequent selection of the inherent static load model presented as the polynomial load model. The usage of the technique to identify static load model at “Fenster” industrial enterprise (in Borisov city) is presented. The ideas considered in the paper can be used for future development of static load model identification methods with the data obtained during both active experiment and in other operating models of electric power systems. 展开更多
关键词 static load model electric power system load power factor step-down transformer substation
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Chrysophanol attenuates lead exposure-induced injury to hippocampal neurons in neonatal mice 被引量:7
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作者 Ji Zhang Chunlin Yan +3 位作者 Shu Wang Yong Hou Guiping Xue Li Zhang 《Neural Regeneration Research》 SCIE CAS CSCD 2014年第9期924-930,共7页
Previous studies have shown that chrysophanol protects against learning and memory impairments in lead-exposed adult mice. In the present study, we investigated whether chrysophanol can alleviate learning and memory d... Previous studies have shown that chrysophanol protects against learning and memory impairments in lead-exposed adult mice. In the present study, we investigated whether chrysophanol can alleviate learning and memory dysfunction and hippocampal neuronal injury in lead-exposed neonatal mice. At the end of lactation, chrysophanol(0.1, 1.0, 10.0 mg/kg) was administered to the neonatal mice by intraperitoneal injection for 15 days. Chrysophanol significantly alleviated injury to hippocampal neurons and improved learning and memory abilities in the lead-poisoned neonatal mice. Chrysophanol also significantly decreased lead content in blood, brain, heart, spleen, liver and kidney in the lead-exposed neonatal mice. The levels of malondialdehyde in the brain, liver and kidney were significantly reduced, and superoxide dismutase and glutathione peroxidase activities were significantly increased after chrysophanol treatment. Collectively, these findings indicate that chrysophanol can significantly reduce damage to hippocampal neurons in lead-exposed neonatal mice. 展开更多
关键词 nerve regeneration traditional Chinese medicine CHRYSOPHANOL lead poisoning lead MALONDIALDEHYDE superoxide dismutase glutathione peroxidase neurons neonatal mice antioxidant learning and memory Morris water maze step-down test hippocampal neurons ULTRASTRUCTURE Medical Scientific Research Project of Health Bureau of Hebei Province neural regeneration
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QFP接地失效研究 被引量:1
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作者 彭元训 熊军 《现代表面贴装资讯》 2011年第6期13-15,共3页
SMT技术的发展促进了电子制造业的繁荣,芯片封装技术得到前所未有的发展,作为一种常规的封装形式,通过QFP封装技术(Plastic Quad Flat Pockage)实现的CPU技术蓟装操作方便,寄生参数减小,适合高频应用,基于QFP封装的以上特点,QF... SMT技术的发展促进了电子制造业的繁荣,芯片封装技术得到前所未有的发展,作为一种常规的封装形式,通过QFP封装技术(Plastic Quad Flat Pockage)实现的CPU技术蓟装操作方便,寄生参数减小,适合高频应用,基于QFP封装的以上特点,QFP的可制造性及产品的焊接可靠性要求也越来越高,根据业界各大厂商的提供的资料,焊脚的平面和接地焊盘的平面有0.05-0.15mm不等的间距,焊接的难点主要出现在接地不良以及I/O开路,为了提高制造良率,必须详细探讨QFP的结构特点,以便更好地提高整机焊接的可靠性。 展开更多
关键词 接地焊盘 step-up模板 QFP 锡膏厚度
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SARS-CoV-2 and the pancreas: What do we know about acute pancreatitis in COVID-19 positive patients?
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作者 Giuseppe Brisinda Maria Michela Chiarello +4 位作者 Giuseppe Tropeano Gaia Altieri Caterina Puccioni Pietro Fransvea Valentina Bianchi 《World Journal of Gastroenterology》 SCIE CAS 2022年第36期5240-5249,共10页
Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)can cause pancreatic damage,both directly to the pancreas via angiotensin-converting enzyme 2 receptors(the transmembrane proteins required for SARS-CoV-2 ent... Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)can cause pancreatic damage,both directly to the pancreas via angiotensin-converting enzyme 2 receptors(the transmembrane proteins required for SARS-CoV-2 entry,which are highly expressed by pancreatic cells)and indirectly through locoregional vasculitis and thrombosis.Despite that,there is no clear evidence that SARS-CoV-2 is an etiological agent of acute pancreatitis.Acute pancreatitis in coronavirus disease 2019(COVID-19)positive patients often recognizes biliary or alcoholic etiology.The prevalence of acute pancreatitis in COVID-19 positive patients is not exactly known.However,COVID-19 positive patients with acute pancreatitis have a higher mortality and an increased risk of intensive care unit admission and necrosis compared to COVID-19 negative patients.Acute respiratory distress syndrome is the most frequent cause of death in COVID-19 positive patients and concomitant acute pancreatitis.In this article,we reported recent evidence on the correlation between COVID-19 infection and acute pancreatitis. 展开更多
关键词 Acute pancreatitis SARS-CoV-2 Severe acute pancreatitis Multiparametric scores Infected necrosis step-up approach
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Basic fibroblast growth factor improves learning and memory functions in chronic stress mice
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作者 Xian Qu Chunying Li +1 位作者 Hongchang Liu Chang Su 《Neural Regeneration Research》 SCIE CAS CSCD 2011年第19期1473-1477,共5页
Four weeks of uncertain stress was used to establish an animal model of chronic stress. Basic fibroblast growth factor was injected daily for 15 days following stress induction. Cell morphology in the hippocampal CA3 ... Four weeks of uncertain stress was used to establish an animal model of chronic stress. Basic fibroblast growth factor was injected daily for 15 days following stress induction. Cell morphology in the hippocampal CA3 region of chronic stress mice revealed cell damage. Nitric oxide content and calcium concentration were significantly increased in the hippocampus, and learning and memory functions were significantly decreased. After basic fibroblast growth factor intervention, Ca2~ overload was decreased and neuronal damage was relieved in hippocampal neurons, which improved learning and memory functions in chronic stress mice. Latency was prolonged and the number of errors was decreased in a passive avoidance test. 展开更多
关键词 basic fibroblast growth factor chronic stress step-down test passive avoidance test learning and memory nitric oxide neural regeneration
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Uncertainty of Clinical Thinking and Patient Safety
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作者 Qian Zhao Zhangshun Shen +1 位作者 Hui Guo Jianguo Li 《International Journal of Clinical Medicine》 2020年第8期474-481,共8页
Clinical thinking have the uncertainty, by which there are not a few mistakes caused. So it is necessary to discuss how to deal with the uncertainty of clinical thinking, which originates from the uncertainty of the o... Clinical thinking have the uncertainty, by which there are not a few mistakes caused. So it is necessary to discuss how to deal with the uncertainty of clinical thinking, which originates from the uncertainty of the objective world, social world and medicine knowledge, and can be seen all over clinical activities;Critical thinking which cautious about the interpretation and prediction of scientific theory is the best practice to explore the uncertainty. The essential purpose of medicine is rescuing people, So it is necessary and scientific to take “excluding life-threatening symptoms first” as the first principle of clinical thinking, which is also the primary method to deal with the uncertainty of clinical thinking;By the limited certainty of clinical thinking, procedural thinking is conducive to building a safer health system that is “easy to do right and difficult to do wrong”. 展开更多
关键词 Clinical Thinking UNCERTAINTY Critical Thinking step-down Thinking Procedural Thinking
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一种宽供电范围开关电源变换器设计
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作者 陈修林 王富光 张顺彪 《机车电传动》 北大核心 2015年第3期23-25,34,共4页
为了满足宽供电范围需求,开发设计了一种电感耦合式Step-down CUK变换器开关电源,对该变换器的输入输出电流进行了稳态分析,表明变换器具有的电流连续特性,有利于提升变换器的功率密度;提出了一种变频控制策略及其实现方法,解决了变换... 为了满足宽供电范围需求,开发设计了一种电感耦合式Step-down CUK变换器开关电源,对该变换器的输入输出电流进行了稳态分析,表明变换器具有的电流连续特性,有利于提升变换器的功率密度;提出了一种变频控制策略及其实现方法,解决了变换器的稳定性问题。试验验证及批量装车考核表明该设计具有实用性。 展开更多
关键词 step-down CUK BUCK BOOST 变频控制 开关电源 宽供电范围 中央控制单元
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