An embedded protective device for 35kV power line is worked out based on Philips’ LPC2292 ARM MCU. Several aspects such as embedded design technique adopted in the system framework, application of adaptive theory in ...An embedded protective device for 35kV power line is worked out based on Philips’ LPC2292 ARM MCU. Several aspects such as embedded design technique adopted in the system framework, application of adaptive theory in data acquisition, Board Support Packet (BSP) developing and task dispatching related to operating system are discussed. Both hardware and software framework of the system are given. Advanced hardware platform and software development environment is applied in design of the system, with the advanced co-design technology.展开更多
Protection distance of surge protective devices (SPDs) is an important problem in designing a good location scheme of SPDs in low voltage distribution systems for protecting electrical equipments against over- voltage...Protection distance of surge protective devices (SPDs) is an important problem in designing a good location scheme of SPDs in low voltage distribution systems for protecting electrical equipments against over- voltage caused by lightning stroke. The simplified lumped-parameter circuit model and the circuit method were used to study the protection distance problem of SPDs. The analytical solutions of the load voltage and general equations of the protection distance of SPDs under different load conditions were given. Simulation results of examples proved the validity of the proposed analytical method.展开更多
Transient stability of doubly-fed induction generators(DFIGs)is a major concern in both AC and DC grids,and DFIGs must stay connected for a time during grid faults according to the power grid requirements.For this pur...Transient stability of doubly-fed induction generators(DFIGs)is a major concern in both AC and DC grids,and DFIGs must stay connected for a time during grid faults according to the power grid requirements.For this purpose,this work proposes an overcurrent and overvoltage protective device(OCV-PD)to ensure that DCbased DFIG system can stay connected and operate well during the faults.Compared with a series dynamic braking resistor(SDBR),two aspects are improved.First,a twolevel control strategy and DC inductor circuit are used to ensure that the OCV-PD can limit the current impulse to protect DFIG system during an overcurrent fault.Second,the OCV-PD can protect system from overvoltage fault which a SDBR cannot do.Simulation results verify itsvalidity and feasibility,finding that for overcurrent protection the OCV-PD outperforms a SDBR with an average decreased index of 3.29%,and for overvoltage protection it achieves an average index of 1.02%.展开更多
High quality electric power supply is the prime goal in the modern power systems around the world.One of the main ways to achieve this is the protection of the system which needs to be fast,reliable and cost effective...High quality electric power supply is the prime goal in the modern power systems around the world.One of the main ways to achieve this is the protection of the system which needs to be fast,reliable and cost effective.The objective of this paper is to provide protection of equipments in low voltage(LV)distribution system and thereafter to avoid their failure due to abnormal operating conditions.The proposed device provides protection for industrial,commercial and residential equipments by monitoring under voltage,over voltage and over current conditions using microcontroller,transistor and other discrete components.The microcontroller is the heart of this protective device which performs the major control of the device.The designed circuit can withstand the loads and the set voltage range so as to supply the connected load for any voltage variation between 220 and 240 Volts.It can be used to protect loads such as refrigerator,TV,VCR/DVD player etc.against undesirable over and under voltage conditions as well as surges caused due to sudden failure of power supply mains.This device can also be used directly as standalone equipment between the supply mains and the load.The over/under voltage and over current cut-off with time delay provides over/under-voltage and over current protection and also protection against any transients.展开更多
In this paper,to present a lightweight-developed front underrun protection device(FUPD)for heavy-duty trucks,plain weave carbon fiber reinforced plastic(CFRP)is used instead of the original high-strength steel.First,t...In this paper,to present a lightweight-developed front underrun protection device(FUPD)for heavy-duty trucks,plain weave carbon fiber reinforced plastic(CFRP)is used instead of the original high-strength steel.First,the mechanical and structural properties of plain carbon fiber composite anti-collision beams are comparatively analyzed from a multi-scale perspective.For studying the design capability of carbon fiber composite materials,we investigate the effects of TC-33 carbon fiber diameter(D),fiber yarn width(W)and height(H),and fiber yarn density(N)on the front underrun protective beam of carbon fiber compositematerials.Based on the investigation,a material-structure matching strategy suitable for the front underrun protective beam of heavy-duty trucks is proposed.Next,the composite material structure is optimized by applying size optimization and stack sequence optimization methods to obtain the higher performance carbon fiber composite front underrun protection beam of commercial vehicles.The results show that the fiber yarn height(H)has the greatest influence on the protective beam,and theH1matching scheme for the front underrun protective beamwith a carbon fiber composite structure exhibits superior performance.The proposed method achieves a weight reduction of 55.21% while still meeting regulatory requirements,which demonstrates its remarkable weight reduction effect.展开更多
Objective: The beneficial effect of percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) has been well established, but there is the problem of no-reflow phenomenon which is an a...Objective: The beneficial effect of percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) has been well established, but there is the problem of no-reflow phenomenon which is an adverse prognostic factor in primary PCI. In the present study the effect of a distal protection device (PercuSurge GuardWire; GW) on epicardial blood flow and myocardial perfusion was evaluated. Methods and Results: Patients with AMI were randomly divided into 2 groups, the GW and the control groups. The GW group included 52 patients with AMI who underwent primary PCI with GW protection and the control group included 60 patients who underwent primary PCI without GW protection. Epicardial blood flow in the infarct-related artery (IRA) and myocardial perfusion were evaluated according to the thrombolysis in myocardial infarction (TIMI) flow grade and the myocardial blush grade (MBG). We found TIMI score of 3 was obtained significantly more frequently in the GW group (96%) than in the control group (80%). The MBG score of 3 was obtained also significantly greater in the GW group (65%) than in the control group (33%). Conclusion: Primary PCI with GW protection can significantly improve epicardial blood flow and myocardial perfusion.展开更多
Objective The trial was designed to evaluate the safety and performance of the ev3 Protégé TM stent in the treatment of de novo or re-stenotic common and/or internal carotid artery stenoses with adjunctive u...Objective The trial was designed to evaluate the safety and performance of the ev3 Protégé TM stent in the treatment of de novo or re-stenotic common and/or internal carotid artery stenoses with adjunctive use of a CE-marked filter embolic protection device.Methods This study was a prospective multi-center, single-arm trial. Between June and October 2003, 77 patients were enrolled in 8 investigational centers throughout Europe. The primary endpoint was the incidence of Major Neurological Events (MANE) through one month. Other endpoints were the ability to properly place the stent, and primary patency and MANE after six months. Eligible for the study were patients with a de novo or restenotic target lesion located in the common and/or internal carotid artery (>70% stenosis for asymptomatic and >50% stenosis for symptomatic patients). The ev3 Spider (Embolic Protection Filter was used in 75 of 77 cases. Results In 76 out of the 77 patients (99%), the stent could be successfully implanted with a residual stenosis ≤30% as criterion. Of the 74 patients that had a carotid ultrasound at one month follow-up, none had a re-stenosis of the target lesion. There were three MANEs during or immediately after the procedure (3.9%), two were major and one was a minor stroke. There were eight severe complications (9.1%); six of these happened during or immediately after the procedure and were related to the procedure, none was related to the device. They are resolved without sequelae. No deaths have occurred.Conclusions The Protégé stent is safe and performs well in the treatment of carotid artery stenosis. The technical success rate for placement of the Protégé stent as assessed by the residual stenosis post implant was very high and all stents were successfully deployed. The incidence of MANE was comparable with that in other recent carotid stent studies and still lower than standard CEA.展开更多
The article discusses the possibility of further modernization of the standard microprocessor relay protection of AC overhead system feeders DPA-27.5-TNF, which is operated on the Trans-Baikal Railway by creating an a...The article discusses the possibility of further modernization of the standard microprocessor relay protection of AC overhead system feeders DPA-27.5-TNF, which is operated on the Trans-Baikal Railway by creating an additional automated system of unified templates necessary for the occurrence of “trainability” elements. The templates will be formed via a separate dedicated channel for transmission, processing and storage of the necessary information, not related to the operation of the terminal, with its subsequent visualization at the workplace of the duty personnel of traction substations, together with information from the “GID” software received via another dedicated wired channel. With the help of such a base of unified preset templates, in the future, it will be possible not only to identify the specific causes of each emergency shutdown but also to reduce their number by dynamically adjusting the existing presets of the standard operation algorithm.展开更多
The no-reflow and slow blood flow in the process of PCI treatment may reduce its effectiveness and lead to expansion of infarct in size sometimes. Also the application of thrombolytic agent inside of coronary artery,p...The no-reflow and slow blood flow in the process of PCI treatment may reduce its effectiveness and lead to expansion of infarct in size sometimes. Also the application of thrombolytic agent inside of coronary artery,platelet inhibitors GP Ⅱ/Ⅲ or direct thrombectomy can＇t improve short or long-term clinical outcomes, So we evaluated the safety and efficacy of distal protection device （GuardWire PlusTM） in the acute myocardial in farction （AMI） combined with percutaneous coronary intervention （PCI）. Method Seventy-two patients with acute myocardial infarction receiving emergency PCI were randomly assigned into the distal protection group （GW group） and non-distal protection group（NGW） group. Data analyzed between the two groups were included the clinical characteristics, angiographic results, ST segment resolution, postoperative TIMI flow grade, TIMI frame count, myocardial blush grade, the left ventricular ejection fraction （LVEF） by eehocardiography in a Week after or 3 months after PCI, myocardial enzymes,preoperative and postoperative neuroendoerine biomarkers： endothelin （ET）, plasma renin activity （PRA）, angiotensin Ⅱ （AII）, aldosterone（ALD）, norepinephrine（NE）, epinephrine （E）. Results ST segment resolution ≥ 50% was significantly higher in the GW group （68.4%） than in NGW group （41.2%, P 〈 0.05）. Early peak CK-MB and CTNI in GW group versus NGW group （8.63 ±2.42 hours vs 11.18 ±2.26 hours,10.16 ±2.96 hours vs 12.35 ±2.06 hours）, and peak reduction difference were observed （63.3 ±9.82 vs 74.28 ＋ 6.15 P = 0.000, 18.01 ＋ 7.21 vs 21.48 ±5.61 P = 0.027）. Left ventricular ejection fraction （LVEF） was higher in GW group （P = 0.01） than in NGW group. TIMI grade exhibited no difference while TIMI frame count （P = 0.043） and myocardial blush grade were significantly different （P = 0.0001）. Postoperative biomarkers in endocrine expression were higher significantly in NGR group （P 〈 0.05）. Conclusions Emergency PCI combined with distal protection device can help prevent distal embolism, reduce the risk of no-reflow and slow flow and thereafter improve the prognosis in AMI patients.展开更多
Objectives To evaluate the feasibility and safety of distal protection device (PercuSurge) during percutaneous coronary intervention (PCI) in patients with acute coronary syndrome. Methods From October 2004 to August ...Objectives To evaluate the feasibility and safety of distal protection device (PercuSurge) during percutaneous coronary intervention (PCI) in patients with acute coronary syndrome. Methods From October 2004 to August 2007, 40 patients with high risk acute coronary syndrome who received primary coronary intervention were included in this study. Patients were divided into two groups according to whether PercuSurge was attempted during PCI. The basic clinical characteristics, angiographic results, and follow-up data before discharge were compared. Coronary arteries blood flow thrombolysis in myocardial infarction (TIMI) grade, TIMI myocardial perfusion (TMP) grade and the rate of no-reflow were performed in all cases after PCI. Results There was no significant difference between the two groups in basic clinical characteristics and angiography before PCI (P>0.05). All patients underwent PCI successfully in both groups. In the PercuSurge group, PCI with PercuSurge guardwire protection was performed successfully in 18 patients. There was significant difference between the two groups in TIMI 3 flows gained in target vessels after PCI. Better percentage of TMP grade 3 of target vessels was achieved in PercuSurge group. Less no-reflow were found in PercuSurge group. There were lower peak troponin I and serum MB isoenzyme of creatine kinase levels, higher left ventricular ejection fraction and smaller left ventricular end-diastolic dimension in the PercuSurge group after PCI at the date before discharge (P<0.05). There was no major adverse cardiac events in PercuSurge group, only one patient died in the control group. Conclusions This study demonstrates that using the PercuSurge Guardwire system during PCI in high risk acute coronary syndrome patients to prevent no-reflow is feasibility and safety.展开更多
In this work, we show that an excessive lattice heating problem can occur in the diode electrostatic discharge (ESD) protection device connected to a V<sub>DD</sub> bus in the popular diode input prot...In this work, we show that an excessive lattice heating problem can occur in the diode electrostatic discharge (ESD) protection device connected to a V<sub>DD</sub> bus in the popular diode input protection scheme, which is favorably used in CMOS RF ICs. To figure out the reason for the excessive lattice heating, we construct an equivalent circuit for input human-body model (HBM) test environment of a CMOS chip equipped with the diode protection circuit, and execute mixed-mode transient simulations utilizing a 2-D device simulator. We analyze the simulation results in detail to show out that a parasitic pnp bipolar transistor action relating nearby p<sup>+</sup>-substrate contacts is responsible for the excessive lattice heating in the diode protection device, which has never been focused before anywhere.展开更多
Belt conveyor is a kind of important equipment for transporting coal mines, and is also a facility for connecting various processes. It plays a vital role in the supply of raw materials. At present, people have used b...Belt conveyor is a kind of important equipment for transporting coal mines, and is also a facility for connecting various processes. It plays a vital role in the supply of raw materials. At present, people have used belt conveyors in the mining, production, transportation and processing processes of coal mines. It not only has a large transportation volume, but also can be applied in complex working environments. The equipment has a strong carrying capacity and supports transportation by the Bureau of Parks and Roads. This paper gives an overview and analysis of the material blocking protection device of belt conveyor, looking for a proximity switch, combining with the problems encountered in the test, and based on the working principle of belt conveyor, puts forward effective improvement measures of the device, increasing the weight of the detection door in the transformation, and improving the use efficiency.展开更多
In recent years, microelectronic components are more widely used in relay protection devices, but most of the electronic devices are electronic sensitive devices, which are easy to be affected by interference. When th...In recent years, microelectronic components are more widely used in relay protection devices, but most of the electronic devices are electronic sensitive devices, which are easy to be affected by interference. When the relay protection devices are interfered in the power system, if there is a fault, it will affect the overall security of the power grid, resulting in the power grid cannot operate stably. When the interference energy exceeds the maximum allowable energy of the logic circuit, it will directly damage the components and affect the normal operation of the relay protection device. Therefore, strengthening the anti-interference ability of relay protection and automation devices has become an important topic in power system.展开更多
Mucosal ulcers are a common yet often overlooked complication during orthodontic treatment,significantly impacting patient comfort and compliance.This letter aims to highlight the prevalence,potential causes,and manag...Mucosal ulcers are a common yet often overlooked complication during orthodontic treatment,significantly impacting patient comfort and compliance.This letter aims to highlight the prevalence,potential causes,and management strategies for mucosal ulcers in orthodontic patients.By reviewing recent literature and clinical observations,we underscore the necessity for proactive measures and tailored interventions to mitigate the incidence and severity of these lesions.Emphasizing the role of patient education and the use of protective devices,we call for a multidisciplinary approach to enhance patient care and treatment outcomes.This discussion is particularly relevant in the context of evolving orthodontic techniques and materials,which necessitate continuous adaptation of clinical practices to ensure patient safety and well-being.展开更多
With its significant morbidity and mortality,anastomotic leaking is a serious concern in the field of colorectal surgical treatments.A number of strategies and actions have been introduced in the last few years with t...With its significant morbidity and mortality,anastomotic leaking is a serious concern in the field of colorectal surgical treatments.A number of strategies and actions have been introduced in the last few years with the goal of reducing the incidence of this surgical complication and the clinical consequences that follow.Based on the most recent academic research,this article aims to provide a comprehensive assessment of the current approaches for the prevention and management of anastomotic leakage in the context of colorectal cancer surgeries.In addition to encouraging more study and innovation in this crucial field,the aim is to provide useful insights and references for clinical practices in the prevention and treatment of anastomotic leakage.展开更多
AIM：To investigate the incidence and general characteristics of sports-related eye injuries in patients visiting the Emergency Department. METHODS： A cross-sectional,multi-center,observational study.Patients with an...AIM：To investigate the incidence and general characteristics of sports-related eye injuries in patients visiting the Emergency Department. METHODS： A cross-sectional,multi-center,observational study.Patients with an injured eye who visited the Emergency Department at one of nine hospitals in Korea were enrolled.All data were prospectively collected between March and September 2010 using a questionnaire.Eye injuries that occurred during risky sports were examined by gender and age.Additionally,the rate of open globe injuries that occurred with and without protective eyewear was examined for each activity.Continuous variables were compared using Student＇s t-test and categorical variables were compared using Chi-square test.RESULTS： A total of 446 patients had sports-related eye injuries.Teenagers（10-19 years old） and young adults（20-29 years old） had the most eye injuries.Eye injuries accounted for 0.2% of Emergency Department patients.Baseball was the most common cause of sports-related eye injuries,followed by soccer and hiking.Protective gear was worn by 9.4% of all patients.Patients that were 30-39 years of age had the highest rate of protective gear use,followed by patients that were 40-49 years of age.The proportion of sports-related eye injuries that were open-globe injuries was highest for soccer and hiking.CONCLUSION： Although injuries were most common in patients below the age of 10 years,these patients had the lowest rate of protective eyewear use.Injuries in adults over 40 years of age most commonly occurred during hiking,but the rate of protective eyewear use was low.Young athletes should be educated on and provided with protective eyewear and policies protective gear use should be established.For older adults,eye protection should be encouraged,especially during hiking.展开更多
A crowbar impulse current circuit for testing the switch-type surge protective device （SPD） is presented. The crowbar circuit consists of a computer control circuit, a trigger voltage pulse generator, a main dischar...A crowbar impulse current circuit for testing the switch-type surge protective device （SPD） is presented. The crowbar circuit consists of a computer control circuit, a trigger voltage pulse generator, a main discharging switch, and a crowbar pseudospark switch. The active trigger technology was studied in the crowbar impulse current circuit. The circuit monitors the main discharging current and generates a trigger signal at a proper time for the crowbar pseudospark switch operation. The trigger characteristics of the main discharge switch and the crowbar pseu- dospark switch were investigated. By monitoring the preset applied capacitor voltage, the gap distance of the main discharging switch could be adjusted to ensure a discharging delay time less than 2 μs. Equipped with a surface ttashover trigger device made of high relative perimittivity dielectric material BaTiO3 （εr = 3460）, the discharge delay time of the crowbar pseudospark switch is less than 85 ns, and the minimum operating voltage is less than 1% of its self-breakdown voltage. With a storage capacitor of 9 μF , an inductor of 18 μH and a crowbar pseudospark switch, a load of 30 mΩ and an applied capacitor voltage of 40 kV, an impulse current waveform of maximum 25 kA was generated with a rise time and time to half peak value of 17.2 μs and 336μs respectively.展开更多
Hearing plays a vital role in the performance of a soldier and is important for speech processing. Noise-induced hearing loss is a significant impairment in the military and can affect combat performance. Military per...Hearing plays a vital role in the performance of a soldier and is important for speech processing. Noise-induced hearing loss is a significant impairment in the military and can affect combat performance. Military personnel are constantly exposed to high levels of noise and it is not surprising that noise induced hearing loss and tinnitus remain the second most prevalent service-connected disabilities. Unfortunately, unlike civilian personnel, military personnel have little option but to remain in noisy environments in order to complete specific tasks and missions. Use of hearing protection devices and follow-up audiological tests have become the mainstay of prevention of noise-induced hearing loss. This review focuses on sources of noise within the military, pathophysiology and management of patients with noise induced hearing loss.展开更多
This paper analyzes the effect of exposure to noise among industrial workers in Nigeria to discover the level of exposure to noise that causes auditory defects or noise-induced hearing loss (NIHL), this paper primaril...This paper analyzes the effect of exposure to noise among industrial workers in Nigeria to discover the level of exposure to noise that causes auditory defects or noise-induced hearing loss (NIHL), this paper primarily covers the evaluation of hearing impairment and its severity on exposure to loud sounds (acoustic trauma) and the role of hearing protective devices for industrial workers for prevention of Noise Induced Hearing Loss (NIHL). The paper also discusses the findings and guides as preventive methods for such industries. A total sample of seventy (70) workers were selected from three (3) manufacturing industries for this study. This study revealed a statistically significant difference in the hearing threshold within the selected industries over the selected period of time relating to the theory of excessive noise present in a given environment tends to affect people or in this case study employees hearing if proper hearing protection isn’t used for prolonged hours or time, the study also surveys the various effect of noise on human health including various steps of noise control in such settings.展开更多
文摘An embedded protective device for 35kV power line is worked out based on Philips’ LPC2292 ARM MCU. Several aspects such as embedded design technique adopted in the system framework, application of adaptive theory in data acquisition, Board Support Packet (BSP) developing and task dispatching related to operating system are discussed. Both hardware and software framework of the system are given. Advanced hardware platform and software development environment is applied in design of the system, with the advanced co-design technology.
文摘Protection distance of surge protective devices (SPDs) is an important problem in designing a good location scheme of SPDs in low voltage distribution systems for protecting electrical equipments against over- voltage caused by lightning stroke. The simplified lumped-parameter circuit model and the circuit method were used to study the protection distance problem of SPDs. The analytical solutions of the load voltage and general equations of the protection distance of SPDs under different load conditions were given. Simulation results of examples proved the validity of the proposed analytical method.
基金supported by Natural Science Foundation of China(No.61473170)Key R&D Plan Project of Shandong Province,PRC(No.2016GSF115018)
文摘Transient stability of doubly-fed induction generators(DFIGs)is a major concern in both AC and DC grids,and DFIGs must stay connected for a time during grid faults according to the power grid requirements.For this purpose,this work proposes an overcurrent and overvoltage protective device(OCV-PD)to ensure that DCbased DFIG system can stay connected and operate well during the faults.Compared with a series dynamic braking resistor(SDBR),two aspects are improved.First,a twolevel control strategy and DC inductor circuit are used to ensure that the OCV-PD can limit the current impulse to protect DFIG system during an overcurrent fault.Second,the OCV-PD can protect system from overvoltage fault which a SDBR cannot do.Simulation results verify itsvalidity and feasibility,finding that for overcurrent protection the OCV-PD outperforms a SDBR with an average decreased index of 3.29%,and for overvoltage protection it achieves an average index of 1.02%.
文摘High quality electric power supply is the prime goal in the modern power systems around the world.One of the main ways to achieve this is the protection of the system which needs to be fast,reliable and cost effective.The objective of this paper is to provide protection of equipments in low voltage(LV)distribution system and thereafter to avoid their failure due to abnormal operating conditions.The proposed device provides protection for industrial,commercial and residential equipments by monitoring under voltage,over voltage and over current conditions using microcontroller,transistor and other discrete components.The microcontroller is the heart of this protective device which performs the major control of the device.The designed circuit can withstand the loads and the set voltage range so as to supply the connected load for any voltage variation between 220 and 240 Volts.It can be used to protect loads such as refrigerator,TV,VCR/DVD player etc.against undesirable over and under voltage conditions as well as surges caused due to sudden failure of power supply mains.This device can also be used directly as standalone equipment between the supply mains and the load.The over/under voltage and over current cut-off with time delay provides over/under-voltage and over current protection and also protection against any transients.
基金supported by the Guangxi Science and Technology Plan and Project(Grant Numbers 2021AC19131 and 2022AC21140)Guangxi University of Science and Technology Doctoral Fund Project(Grant Number 20Z40).
文摘In this paper,to present a lightweight-developed front underrun protection device(FUPD)for heavy-duty trucks,plain weave carbon fiber reinforced plastic(CFRP)is used instead of the original high-strength steel.First,the mechanical and structural properties of plain carbon fiber composite anti-collision beams are comparatively analyzed from a multi-scale perspective.For studying the design capability of carbon fiber composite materials,we investigate the effects of TC-33 carbon fiber diameter(D),fiber yarn width(W)and height(H),and fiber yarn density(N)on the front underrun protective beam of carbon fiber compositematerials.Based on the investigation,a material-structure matching strategy suitable for the front underrun protective beam of heavy-duty trucks is proposed.Next,the composite material structure is optimized by applying size optimization and stack sequence optimization methods to obtain the higher performance carbon fiber composite front underrun protection beam of commercial vehicles.The results show that the fiber yarn height(H)has the greatest influence on the protective beam,and theH1matching scheme for the front underrun protective beamwith a carbon fiber composite structure exhibits superior performance.The proposed method achieves a weight reduction of 55.21% while still meeting regulatory requirements,which demonstrates its remarkable weight reduction effect.
文摘Objective: The beneficial effect of percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) has been well established, but there is the problem of no-reflow phenomenon which is an adverse prognostic factor in primary PCI. In the present study the effect of a distal protection device (PercuSurge GuardWire; GW) on epicardial blood flow and myocardial perfusion was evaluated. Methods and Results: Patients with AMI were randomly divided into 2 groups, the GW and the control groups. The GW group included 52 patients with AMI who underwent primary PCI with GW protection and the control group included 60 patients who underwent primary PCI without GW protection. Epicardial blood flow in the infarct-related artery (IRA) and myocardial perfusion were evaluated according to the thrombolysis in myocardial infarction (TIMI) flow grade and the myocardial blush grade (MBG). We found TIMI score of 3 was obtained significantly more frequently in the GW group (96%) than in the control group (80%). The MBG score of 3 was obtained also significantly greater in the GW group (65%) than in the control group (33%). Conclusion: Primary PCI with GW protection can significantly improve epicardial blood flow and myocardial perfusion.
文摘Objective The trial was designed to evaluate the safety and performance of the ev3 Protégé TM stent in the treatment of de novo or re-stenotic common and/or internal carotid artery stenoses with adjunctive use of a CE-marked filter embolic protection device.Methods This study was a prospective multi-center, single-arm trial. Between June and October 2003, 77 patients were enrolled in 8 investigational centers throughout Europe. The primary endpoint was the incidence of Major Neurological Events (MANE) through one month. Other endpoints were the ability to properly place the stent, and primary patency and MANE after six months. Eligible for the study were patients with a de novo or restenotic target lesion located in the common and/or internal carotid artery (>70% stenosis for asymptomatic and >50% stenosis for symptomatic patients). The ev3 Spider (Embolic Protection Filter was used in 75 of 77 cases. Results In 76 out of the 77 patients (99%), the stent could be successfully implanted with a residual stenosis ≤30% as criterion. Of the 74 patients that had a carotid ultrasound at one month follow-up, none had a re-stenosis of the target lesion. There were three MANEs during or immediately after the procedure (3.9%), two were major and one was a minor stroke. There were eight severe complications (9.1%); six of these happened during or immediately after the procedure and were related to the procedure, none was related to the device. They are resolved without sequelae. No deaths have occurred.Conclusions The Protégé stent is safe and performs well in the treatment of carotid artery stenosis. The technical success rate for placement of the Protégé stent as assessed by the residual stenosis post implant was very high and all stents were successfully deployed. The incidence of MANE was comparable with that in other recent carotid stent studies and still lower than standard CEA.
文摘The article discusses the possibility of further modernization of the standard microprocessor relay protection of AC overhead system feeders DPA-27.5-TNF, which is operated on the Trans-Baikal Railway by creating an additional automated system of unified templates necessary for the occurrence of “trainability” elements. The templates will be formed via a separate dedicated channel for transmission, processing and storage of the necessary information, not related to the operation of the terminal, with its subsequent visualization at the workplace of the duty personnel of traction substations, together with information from the “GID” software received via another dedicated wired channel. With the help of such a base of unified preset templates, in the future, it will be possible not only to identify the specific causes of each emergency shutdown but also to reduce their number by dynamically adjusting the existing presets of the standard operation algorithm.
文摘The no-reflow and slow blood flow in the process of PCI treatment may reduce its effectiveness and lead to expansion of infarct in size sometimes. Also the application of thrombolytic agent inside of coronary artery,platelet inhibitors GP Ⅱ/Ⅲ or direct thrombectomy can＇t improve short or long-term clinical outcomes, So we evaluated the safety and efficacy of distal protection device （GuardWire PlusTM） in the acute myocardial in farction （AMI） combined with percutaneous coronary intervention （PCI）. Method Seventy-two patients with acute myocardial infarction receiving emergency PCI were randomly assigned into the distal protection group （GW group） and non-distal protection group（NGW） group. Data analyzed between the two groups were included the clinical characteristics, angiographic results, ST segment resolution, postoperative TIMI flow grade, TIMI frame count, myocardial blush grade, the left ventricular ejection fraction （LVEF） by eehocardiography in a Week after or 3 months after PCI, myocardial enzymes,preoperative and postoperative neuroendoerine biomarkers： endothelin （ET）, plasma renin activity （PRA）, angiotensin Ⅱ （AII）, aldosterone（ALD）, norepinephrine（NE）, epinephrine （E）. Results ST segment resolution ≥ 50% was significantly higher in the GW group （68.4%） than in NGW group （41.2%, P 〈 0.05）. Early peak CK-MB and CTNI in GW group versus NGW group （8.63 ±2.42 hours vs 11.18 ±2.26 hours,10.16 ±2.96 hours vs 12.35 ±2.06 hours）, and peak reduction difference were observed （63.3 ±9.82 vs 74.28 ＋ 6.15 P = 0.000, 18.01 ＋ 7.21 vs 21.48 ±5.61 P = 0.027）. Left ventricular ejection fraction （LVEF） was higher in GW group （P = 0.01） than in NGW group. TIMI grade exhibited no difference while TIMI frame count （P = 0.043） and myocardial blush grade were significantly different （P = 0.0001）. Postoperative biomarkers in endocrine expression were higher significantly in NGR group （P 〈 0.05）. Conclusions Emergency PCI combined with distal protection device can help prevent distal embolism, reduce the risk of no-reflow and slow flow and thereafter improve the prognosis in AMI patients.
文摘Objectives To evaluate the feasibility and safety of distal protection device (PercuSurge) during percutaneous coronary intervention (PCI) in patients with acute coronary syndrome. Methods From October 2004 to August 2007, 40 patients with high risk acute coronary syndrome who received primary coronary intervention were included in this study. Patients were divided into two groups according to whether PercuSurge was attempted during PCI. The basic clinical characteristics, angiographic results, and follow-up data before discharge were compared. Coronary arteries blood flow thrombolysis in myocardial infarction (TIMI) grade, TIMI myocardial perfusion (TMP) grade and the rate of no-reflow were performed in all cases after PCI. Results There was no significant difference between the two groups in basic clinical characteristics and angiography before PCI (P>0.05). All patients underwent PCI successfully in both groups. In the PercuSurge group, PCI with PercuSurge guardwire protection was performed successfully in 18 patients. There was significant difference between the two groups in TIMI 3 flows gained in target vessels after PCI. Better percentage of TMP grade 3 of target vessels was achieved in PercuSurge group. Less no-reflow were found in PercuSurge group. There were lower peak troponin I and serum MB isoenzyme of creatine kinase levels, higher left ventricular ejection fraction and smaller left ventricular end-diastolic dimension in the PercuSurge group after PCI at the date before discharge (P<0.05). There was no major adverse cardiac events in PercuSurge group, only one patient died in the control group. Conclusions This study demonstrates that using the PercuSurge Guardwire system during PCI in high risk acute coronary syndrome patients to prevent no-reflow is feasibility and safety.
文摘In this work, we show that an excessive lattice heating problem can occur in the diode electrostatic discharge (ESD) protection device connected to a V<sub>DD</sub> bus in the popular diode input protection scheme, which is favorably used in CMOS RF ICs. To figure out the reason for the excessive lattice heating, we construct an equivalent circuit for input human-body model (HBM) test environment of a CMOS chip equipped with the diode protection circuit, and execute mixed-mode transient simulations utilizing a 2-D device simulator. We analyze the simulation results in detail to show out that a parasitic pnp bipolar transistor action relating nearby p<sup>+</sup>-substrate contacts is responsible for the excessive lattice heating in the diode protection device, which has never been focused before anywhere.
文摘Belt conveyor is a kind of important equipment for transporting coal mines, and is also a facility for connecting various processes. It plays a vital role in the supply of raw materials. At present, people have used belt conveyors in the mining, production, transportation and processing processes of coal mines. It not only has a large transportation volume, but also can be applied in complex working environments. The equipment has a strong carrying capacity and supports transportation by the Bureau of Parks and Roads. This paper gives an overview and analysis of the material blocking protection device of belt conveyor, looking for a proximity switch, combining with the problems encountered in the test, and based on the working principle of belt conveyor, puts forward effective improvement measures of the device, increasing the weight of the detection door in the transformation, and improving the use efficiency.
文摘In recent years, microelectronic components are more widely used in relay protection devices, but most of the electronic devices are electronic sensitive devices, which are easy to be affected by interference. When the relay protection devices are interfered in the power system, if there is a fault, it will affect the overall security of the power grid, resulting in the power grid cannot operate stably. When the interference energy exceeds the maximum allowable energy of the logic circuit, it will directly damage the components and affect the normal operation of the relay protection device. Therefore, strengthening the anti-interference ability of relay protection and automation devices has become an important topic in power system.
文摘Mucosal ulcers are a common yet often overlooked complication during orthodontic treatment,significantly impacting patient comfort and compliance.This letter aims to highlight the prevalence,potential causes,and management strategies for mucosal ulcers in orthodontic patients.By reviewing recent literature and clinical observations,we underscore the necessity for proactive measures and tailored interventions to mitigate the incidence and severity of these lesions.Emphasizing the role of patient education and the use of protective devices,we call for a multidisciplinary approach to enhance patient care and treatment outcomes.This discussion is particularly relevant in the context of evolving orthodontic techniques and materials,which necessitate continuous adaptation of clinical practices to ensure patient safety and well-being.
基金supported by grants from the Graduate Research-Innovation Project in Jiangsu province(No.SJCX22_1816)the Graduate Research and Practice Innovation Plan of Graduate Education Innovation Project in Jiangsu Province(No.SJCX211644)+2 种基金Social Development Project of Key R&D Plan of Jiangsu Provincial Department of Science and Technology(No.BE2022773)Hospital Project of Subei People’s Hospital(No.YYGL202228)the Social Development-Health Care Project of Yangzhou,Jiangsu Province(No.YZ2021075).
文摘With its significant morbidity and mortality,anastomotic leaking is a serious concern in the field of colorectal surgical treatments.A number of strategies and actions have been introduced in the last few years with the goal of reducing the incidence of this surgical complication and the clinical consequences that follow.Based on the most recent academic research,this article aims to provide a comprehensive assessment of the current approaches for the prevention and management of anastomotic leakage in the context of colorectal cancer surgeries.In addition to encouraging more study and innovation in this crucial field,the aim is to provide useful insights and references for clinical practices in the prevention and treatment of anastomotic leakage.
基金Supported by the Research Program funded by the Korea Centers for Disease Control and Prevention(KCDC)(No.2010-E33005-00)
文摘AIM：To investigate the incidence and general characteristics of sports-related eye injuries in patients visiting the Emergency Department. METHODS： A cross-sectional,multi-center,observational study.Patients with an injured eye who visited the Emergency Department at one of nine hospitals in Korea were enrolled.All data were prospectively collected between March and September 2010 using a questionnaire.Eye injuries that occurred during risky sports were examined by gender and age.Additionally,the rate of open globe injuries that occurred with and without protective eyewear was examined for each activity.Continuous variables were compared using Student＇s t-test and categorical variables were compared using Chi-square test.RESULTS： A total of 446 patients had sports-related eye injuries.Teenagers（10-19 years old） and young adults（20-29 years old） had the most eye injuries.Eye injuries accounted for 0.2% of Emergency Department patients.Baseball was the most common cause of sports-related eye injuries,followed by soccer and hiking.Protective gear was worn by 9.4% of all patients.Patients that were 30-39 years of age had the highest rate of protective gear use,followed by patients that were 40-49 years of age.The proportion of sports-related eye injuries that were open-globe injuries was highest for soccer and hiking.CONCLUSION： Although injuries were most common in patients below the age of 10 years,these patients had the lowest rate of protective eyewear use.Injuries in adults over 40 years of age most commonly occurred during hiking,but the rate of protective eyewear use was low.Young athletes should be educated on and provided with protective eyewear and policies protective gear use should be established.For older adults,eye protection should be encouraged,especially during hiking.
文摘A crowbar impulse current circuit for testing the switch-type surge protective device （SPD） is presented. The crowbar circuit consists of a computer control circuit, a trigger voltage pulse generator, a main discharging switch, and a crowbar pseudospark switch. The active trigger technology was studied in the crowbar impulse current circuit. The circuit monitors the main discharging current and generates a trigger signal at a proper time for the crowbar pseudospark switch operation. The trigger characteristics of the main discharge switch and the crowbar pseu- dospark switch were investigated. By monitoring the preset applied capacitor voltage, the gap distance of the main discharging switch could be adjusted to ensure a discharging delay time less than 2 μs. Equipped with a surface ttashover trigger device made of high relative perimittivity dielectric material BaTiO3 （εr = 3460）, the discharge delay time of the crowbar pseudospark switch is less than 85 ns, and the minimum operating voltage is less than 1% of its self-breakdown voltage. With a storage capacitor of 9 μF , an inductor of 18 μH and a crowbar pseudospark switch, a load of 30 mΩ and an applied capacitor voltage of 40 kV, an impulse current waveform of maximum 25 kA was generated with a rise time and time to half peak value of 17.2 μs and 336μs respectively.
文摘Hearing plays a vital role in the performance of a soldier and is important for speech processing. Noise-induced hearing loss is a significant impairment in the military and can affect combat performance. Military personnel are constantly exposed to high levels of noise and it is not surprising that noise induced hearing loss and tinnitus remain the second most prevalent service-connected disabilities. Unfortunately, unlike civilian personnel, military personnel have little option but to remain in noisy environments in order to complete specific tasks and missions. Use of hearing protection devices and follow-up audiological tests have become the mainstay of prevention of noise-induced hearing loss. This review focuses on sources of noise within the military, pathophysiology and management of patients with noise induced hearing loss.
文摘This paper analyzes the effect of exposure to noise among industrial workers in Nigeria to discover the level of exposure to noise that causes auditory defects or noise-induced hearing loss (NIHL), this paper primarily covers the evaluation of hearing impairment and its severity on exposure to loud sounds (acoustic trauma) and the role of hearing protective devices for industrial workers for prevention of Noise Induced Hearing Loss (NIHL). The paper also discusses the findings and guides as preventive methods for such industries. A total sample of seventy (70) workers were selected from three (3) manufacturing industries for this study. This study revealed a statistically significant difference in the hearing threshold within the selected industries over the selected period of time relating to the theory of excessive noise present in a given environment tends to affect people or in this case study employees hearing if proper hearing protection isn’t used for prolonged hours or time, the study also surveys the various effect of noise on human health including various steps of noise control in such settings.
