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
There are very few reports concerning the failure of devices used in carotid artery stenting. Here we report a fracture of the distal part of the guiding wire of a cerebral protection device during carotid artery sten...There are very few reports concerning the failure of devices used in carotid artery stenting. Here we report a fracture of the distal part of the guiding wire of a cerebral protection device during carotid artery stenting for management of a restenotic lesion after carotid endarterectomy.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
Two kinds of argon shroud protection devices with two different basic structures were designed and investigated. Industrial experiments and numerical simulations were used to examine the protection effect, and the mec...Two kinds of argon shroud protection devices with two different basic structures were designed and investigated. Industrial experiments and numerical simulations were used to examine the protection effect, and the mechanism of air entrapment during the casting of steel ingots was analyzed. The influence of the structure of the argon shroud protection device on the protection effect was investigated. An argon shroud protection device mounted to the nozzle holder on the bottom of the ladle does not provide a good protection effect because air can easily flow into the teeming system and cause reoxidation of molten steel during teeming. By contrast, an argon shroud protection device seated on the top of the central trumpet provides an excellent protection effect, where air has little chance of flowing into the teeming system during casting. The feasibilities of the argon shroud protection devices are discussed.展开更多
The article discusses the possibility of a potential reduction in the number of operations of microprocessor relay protection of feeders of the contact network of AC railways TsZA-27.5-FKS (FTS) for unknown reasons. R...The article discusses the possibility of a potential reduction in the number of operations of microprocessor relay protection of feeders of the contact network of AC railways TsZA-27.5-FKS (FTS) for unknown reasons. Real statistics on the number of microprocessor relay protection operations at the Buryatskaya traction substation are presented, simulation of the real train situation (in accordance with the regime maps of the throughput capacity of the sections of the Trans-Baikal railway) was carried out in the specialized software complex “KORTES”. Based on the results of the analysis of simulation modeling, the process of forming a unified template of settings using neural network technologies is considered, which characterizes only this specific regular train situation. To protect objects in the event of pre-emergency and emergency modes of operation of the traction power supply system, a variant of changing the standard operation algorithm of the TsZA-27.5-FKS (FTS) terminal by introducing additional blocks for calculating the predictive functions of current and voltage has been proposed.展开更多
In this paper, the relationship between the protection and control of asynchronous motor and all sorts of protection devices for asynchronous motor are briefly expounded. The protection of motor has mainly developed i...In this paper, the relationship between the protection and control of asynchronous motor and all sorts of protection devices for asynchronous motor are briefly expounded. The protection of motor has mainly developed in three stages： thermal relay, electronic integrated protector, and microcomputer protector. In terms of sampling methods, the protection can be divided into two types： （1） the sampling current detection, which is implemented using a thermal relay with circuit breaker for the thermomagnetic tripping motor protection, and an electronic and solid state relay with circuit breaker and sof~ starter for the thermomagnetic tripping motor protection; （2） the sampling temperature detection, which is to directly detect electromotor winding temperature using bimetallic strip temperature relay, thermal protector, detecting coil, and heat resistance temperature relay. However, the second method is very expensive and difficult to maintain because a motor winding is necessary to directly bury, so it is used only in the cases requiring some frequent operations. Finally, the harmonious cooperation between overload protection device and motor or between overload protection device and short circuit protection device must be considered regardless of the protection device model.展开更多
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
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
After controls,including engineering and management,thefinal way to control noise is to use hearing protection devices.Duetothelack ofastandardized questionnaireregarding investigatingworkers’use of hearing protection...After controls,including engineering and management,thefinal way to control noise is to use hearing protection devices.Duetothelack ofastandardized questionnaireregarding investigatingworkers’use of hearing protection devices on the basis of the BASNEF behavioral model,the present study was conducted to investigate the effect of health education based on the BASNEF model on the use of hearing protection devices in workers of an auto-mobile manufacturing plant in Iran.This quasi-experimental and prospective intervention study was performed on 80 workers at an automobile manufacturing plant who are exposed to noise levels above 85 decibels and donot use hearing protection devices.In this study,40 people working in a cast iron foundry were selected as the inter-vention group,and 40 working in aluminum casting were chosen as the control group.Questionnaires were ana-lyzed at the beginning of the intervention and three months after the intervention in the intervention and control groups.There was no significant difference between the intervention and control groups before the intervention.There was a significant difference between the intervention and control groups after the intervention in the area of knowledge.A significant correlation was observed between the intervention and control groups after the inter-vention program in all areas of the BASNEF educational model except behavioral intention.In this study,the effect of educational intervention on the use of hearing protection devices was investigated,and with the educa-tional intervention,it was tried to get help from influential people and enabling factors in education based on the BASNEF model.The results showed that the educational intervention based on the BASNEF model can improve the knowledge of individuals in both the intervention and control groups.展开更多
With the rapid development of subway lines, more and more electrical problems of track structures are exposed, and the resulting impact is also attracting more and more attention. The electrical safety problems of tra...With the rapid development of subway lines, more and more electrical problems of track structures are exposed, and the resulting impact is also attracting more and more attention. The electrical safety problems of track structure are mainly manifested in three aspects: abnormal distribution of track potential, abnormal return of track structure and abnormal transition resistance of track to ground. Combined with practical engineering experience, common electrical problems and adjustment measures of track structure are summarized, which are used to further analyze the distribution law of track electricity and provide basic research data for solving the safety problems of track electricity.展开更多
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There are very few reports concerning the failure of devices used in carotid artery stenting. Here we report a fracture of the distal part of the guiding wire of a cerebral protection device during carotid artery stenting for management of a restenotic lesion after carotid endarterectomy.
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 the National Natural Science Foundation of China(Grant No.51404018)the State Key Laboratory of Advanced Metallurgy Foundation(No.41614014)
文摘Two kinds of argon shroud protection devices with two different basic structures were designed and investigated. Industrial experiments and numerical simulations were used to examine the protection effect, and the mechanism of air entrapment during the casting of steel ingots was analyzed. The influence of the structure of the argon shroud protection device on the protection effect was investigated. An argon shroud protection device mounted to the nozzle holder on the bottom of the ladle does not provide a good protection effect because air can easily flow into the teeming system and cause reoxidation of molten steel during teeming. By contrast, an argon shroud protection device seated on the top of the central trumpet provides an excellent protection effect, where air has little chance of flowing into the teeming system during casting. The feasibilities of the argon shroud protection devices are discussed.
文摘The article discusses the possibility of a potential reduction in the number of operations of microprocessor relay protection of feeders of the contact network of AC railways TsZA-27.5-FKS (FTS) for unknown reasons. Real statistics on the number of microprocessor relay protection operations at the Buryatskaya traction substation are presented, simulation of the real train situation (in accordance with the regime maps of the throughput capacity of the sections of the Trans-Baikal railway) was carried out in the specialized software complex “KORTES”. Based on the results of the analysis of simulation modeling, the process of forming a unified template of settings using neural network technologies is considered, which characterizes only this specific regular train situation. To protect objects in the event of pre-emergency and emergency modes of operation of the traction power supply system, a variant of changing the standard operation algorithm of the TsZA-27.5-FKS (FTS) terminal by introducing additional blocks for calculating the predictive functions of current and voltage has been proposed.
文摘In this paper, the relationship between the protection and control of asynchronous motor and all sorts of protection devices for asynchronous motor are briefly expounded. The protection of motor has mainly developed in three stages： thermal relay, electronic integrated protector, and microcomputer protector. In terms of sampling methods, the protection can be divided into two types： （1） the sampling current detection, which is implemented using a thermal relay with circuit breaker for the thermomagnetic tripping motor protection, and an electronic and solid state relay with circuit breaker and sof~ starter for the thermomagnetic tripping motor protection; （2） the sampling temperature detection, which is to directly detect electromotor winding temperature using bimetallic strip temperature relay, thermal protector, detecting coil, and heat resistance temperature relay. However, the second method is very expensive and difficult to maintain because a motor winding is necessary to directly bury, so it is used only in the cases requiring some frequent operations. Finally, the harmonious cooperation between overload protection device and motor or between overload protection device and short circuit protection device must be considered regardless of the protection device model.
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This study is related to Project No.20723/1398 from Student Research Committee,Shahid Beheshti University of Medical Sciences,Tehran,Iran.We also appreciate the“Student Research Committee”and“Research&Technology Chancellor”in Shahid Beheshti University of Medical Sciences for their financial support of this study.This study has been approved by the IR.SBMU.
文摘After controls,including engineering and management,thefinal way to control noise is to use hearing protection devices.Duetothelack ofastandardized questionnaireregarding investigatingworkers’use of hearing protection devices on the basis of the BASNEF behavioral model,the present study was conducted to investigate the effect of health education based on the BASNEF model on the use of hearing protection devices in workers of an auto-mobile manufacturing plant in Iran.This quasi-experimental and prospective intervention study was performed on 80 workers at an automobile manufacturing plant who are exposed to noise levels above 85 decibels and donot use hearing protection devices.In this study,40 people working in a cast iron foundry were selected as the inter-vention group,and 40 working in aluminum casting were chosen as the control group.Questionnaires were ana-lyzed at the beginning of the intervention and three months after the intervention in the intervention and control groups.There was no significant difference between the intervention and control groups before the intervention.There was a significant difference between the intervention and control groups after the intervention in the area of knowledge.A significant correlation was observed between the intervention and control groups after the inter-vention program in all areas of the BASNEF educational model except behavioral intention.In this study,the effect of educational intervention on the use of hearing protection devices was investigated,and with the educa-tional intervention,it was tried to get help from influential people and enabling factors in education based on the BASNEF model.The results showed that the educational intervention based on the BASNEF model can improve the knowledge of individuals in both the intervention and control groups.
文摘With the rapid development of subway lines, more and more electrical problems of track structures are exposed, and the resulting impact is also attracting more and more attention. The electrical safety problems of track structure are mainly manifested in three aspects: abnormal distribution of track potential, abnormal return of track structure and abnormal transition resistance of track to ground. Combined with practical engineering experience, common electrical problems and adjustment measures of track structure are summarized, which are used to further analyze the distribution law of track electricity and provide basic research data for solving the safety problems of track electricity.
