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Seismic dynamic monitoring in CO_2 flooding based on characterization of frequency-dependent velocity factor 被引量:2
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作者 张军华 李军 +4 位作者 肖文 谭明友 张云银 崔世凌 曲志鹏 《Applied Geophysics》 SCIE CSCD 2016年第2期307-314,418,共9页
The phase velocity of seismic waves varies with the propagation frequency, and thus frequency-dependent phenomena appear when CO2 gas is injected into a reservoir. By dynamically considering these phenomena with reser... The phase velocity of seismic waves varies with the propagation frequency, and thus frequency-dependent phenomena appear when CO2 gas is injected into a reservoir. By dynamically considering these phenomena with reservoir conditions it is thus feasible to extract the frequency-dependent velocity factor with the aim of monitoring changes in the reservoir both before and after CO2 injection. In the paper, we derive a quantitative expression for the frequency-dependent factor based on the Robinson seismic convolution model. In addition, an inversion equation with a frequency-dependent velocity factor is constructed, and a procedure is implemented using the following four processing steps: decomposition of the spectrum by generalized S transform, wavelet extraction of cross-well seismic traces, spectrum equalization processing, and an extraction method for frequency-dependent velocity factor based on the damped least-square algorithm. An attenuation layered model is then established based on changes in the Q value of the viscoelastic medium, and spectra of migration profiles from forward modeling are obtained and analyzed. Frequency-dependent factors are extracted and compared, and the effectiveness of the method is then verified using a synthetic data. The frequency-dependent velocity factor is finally applied to target processing and oil displacement monitoring based on real seismic data obtained before and after CO2 injection in the G89 well block within Shengli oilfield. Profiles and slices of the frequency-dependent factor determine its ability to indicate differences in CO2 flooding, and the predicting results are highly consistent with those of practical investigations within the well block. 展开更多
关键词 co2 flooding Frequency-dependent velocity factor G89 well block Reservoir dynamic monitoring
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Geophysical monitoring technology for CO_2 sequestration 被引量:1
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作者 马劲风 李琳 +6 位作者 王浩璠 谭明友 崔世凌 张云银 曲志鹏 贾凌云 张树海 《Applied Geophysics》 SCIE CSCD 2016年第2期288-306,417,418,共21页
Geophysical techniques play key roles in the measuring, monitoring, and verifying the safety of CO2 sequestration and in identifying the efficiency of CO2-enhanced oil recovery. Although geophysical monitoring techniq... Geophysical techniques play key roles in the measuring, monitoring, and verifying the safety of CO2 sequestration and in identifying the efficiency of CO2-enhanced oil recovery. Although geophysical monitoring techniques for CO2 sequestration have grown out of conventional oil and gas geophysical exploration techniques, it takes a long time to conduct geophysical monitoring, and there are many barriers and challenges. In this paper, with the initial objective of performing CO2 sequestration, we studied the geophysical tasks associated with evaluating geological storage sites and monitoring CO2 sequestration. Based on our review of the scope of geophysical monitoring techniques and our experience in domestic and international carbon capture and sequestration projects, we analyzed the inherent difficulties and our experiences in geophysical monitoring techniques, especially, with respect to 4D seismic acquisition, processing, and interpretation. 展开更多
关键词 Carbon capture and storage geophysical monitoring 4D seismic monitoring co2 saturation reservoir pressure
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Continuous Glucose Monitoring‐Guided Self‐Management Leads to Diabetes Remission in a Newly Diagnosed Overweight Patient With Type 2 Diabetes:A Brief Report
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作者 Xia Yang Xiu‐Dong Liu Yi‐Qi Guo 《Health Care Science》 2025年第5期350-354,共5页
We report the case of a newly diagnosed overweight patient with type 2 diabetes mellitus who achieved diabetes remission using continuous glucose monitoring(CGM),which promotes patient engagement in self‐management.K... We report the case of a newly diagnosed overweight patient with type 2 diabetes mellitus who achieved diabetes remission using continuous glucose monitoring(CGM),which promotes patient engagement in self‐management.Key measures included selection of a patient newly diagnosed with type 2 diabetes mellitus,use of CGM,analysis of glucose trends and contributing factors,and patient guidance in maintaining a health diary and developing personalized self‐management strategies(e.g.,dietary modification and exercise regimens).Following 6‐month CGM‐guided self‐management,the patient's glycated hemoglobin level decreased from 7.3%at baseline to 6.0%and his body weight decreased from 83 to 77 kg,a 7%reduction;thus,the patient met the criteria for diabetes remission. 展开更多
关键词 continuous glucose monitoring diabetes remission OVERWEIGHT type 2 diabetes mellitus
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Monitoring and simulation of water,heat,and CO_2 fluxes in terrestrial ecosystems based on the APEIS-FLUX system 被引量:4
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作者 WATANABEMasataka WANGQinxue +6 位作者 HAYASHISeiji MURAKAMIShogo LIUJiyuan OUYANGZhu LIYan LIYingnian WANGKelin 《Journal of Geographical Sciences》 SCIE CSCD 2005年第2期131-141,共11页
The Integrated Environmental Monitoring (IEM) project, part of the Asia-Pacific Environmental Innovation Strategy (APEIS) project, developed an integrated environmental monitoring system that can be used to detect, mo... The Integrated Environmental Monitoring (IEM) project, part of the Asia-Pacific Environmental Innovation Strategy (APEIS) project, developed an integrated environmental monitoring system that can be used to detect, monitor, and assess environmental disasters, degradation, and their impacts in the Asia-Pacific region. The system primarily employs data from the moderate resolution imaging spectrometer (MODIS) sensor on the Earth Observation System-(EOS-) Terra/Aqua satellite, as well as those from ground observations at five sites in different ecological systems in China. From the preliminary data analysis on both annual and daily variations of water, heat and CO2 fluxes, we can confirm that this system basically has been working well. The results show that both latent flux and CO2 flux are much greater in the crop field than those in the grassland and the saline desert, whereas the sensible heat flux shows the opposite trend. Different data products from MODIS have very different correspondence, e.g. MODIS-derived land surface temperature has a close correlation with measured ones, but LAI and NPP are quite different from ground measurements, which suggests that the algorithms used to process MODIS data need to be revised by using the local dataset. We are now using the APEIS-FLUX data to develop an integrated model, which can simulate the regional water, heat, and carbon fluxes. Finally, we are expected to use this model to develop more precise high-order MODIS products in Asia-Pacific region. 展开更多
关键词 APEIS-FLUX system Asia-Pacific Environmental Innovation Strategy (APEIS) co2 flux Integrated Environmental monitoring (IEM) MODIS water vapor flux
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大规模CO_(2)地质封存泄漏的问题、影响及管控——研究现状及展望
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作者 白冰 郝敏 +2 位作者 雷宏武 杨横涛 李采 《岩土力学》 北大核心 2026年第1期1-26,共26页
二氧化碳(CO_(2))地质封存作为碳捕集、利用与封存(carbon capture,utilization,and storage,简称CCUS)的核心环节,是削减温室气体排放的重要手段。随着封存规模的不断扩大,CO_(2)泄漏风险的提高将威胁封存项目的安全性和有效性。首先,... 二氧化碳(CO_(2))地质封存作为碳捕集、利用与封存(carbon capture,utilization,and storage,简称CCUS)的核心环节,是削减温室气体排放的重要手段。随着封存规模的不断扩大,CO_(2)泄漏风险的提高将威胁封存项目的安全性和有效性。首先,系统综述了大规模CO_(2)地质封存中泄漏问题及研究现状,探讨了主要泄漏路径及其物理、化学和地质机制,重点分析了井筒、断层/裂隙和盖层等关键通道的泄漏行为,总结了CO_(2)泄漏引发的灾害链及其对地下水、土壤微生物、植被和气候变化的潜在影响,梳理了泄漏监测与风险评估技术的最新进展,突出多源传感、智能分析和多尺度耦合模型的重要作用;然后,探讨了当前泄漏管控与修复的研究进展,包括水泥基材料、聚合物凝胶、生物矿化技术、泡沫技术及纳米技术的应用,指出了这些技术在长期稳定性和大规模封存应用中的局限性;最后,提出未来研究应聚焦泄漏路径机制识别、多源融合监测与智能预警以及适应复杂地质环境的快速响应修复系统,构建全周期的泄漏防控与管理框架。 展开更多
关键词 CO_(2)地质封存 泄漏机制 环境影响 监测手段 风险管控 修复技术
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Fire monitoring in coal mines using wireless underground sensor network and interval type-2 fuzzy logic controller 被引量:3
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作者 Sweta Basu Sutapa Pramanik +2 位作者 Sanghamitra Dey Gautam Panigrahi Dipak Kumar Jana 《International Journal of Coal Science & Technology》 EI 2019年第2期274-285,共12页
From the view of underground coal mining safety system, it is extremely important to continuous monitoring of coal mines for the prompt detection of fires or related problems inspite of its uncertainty and imprecise c... From the view of underground coal mining safety system, it is extremely important to continuous monitoring of coal mines for the prompt detection of fires or related problems inspite of its uncertainty and imprecise characteristics. Therefore, evaluation and inferring the data perfectly to prevent fire related accidental risk in underground coal mining (UMC) system are very necessary. In the present article, we have proposed a novel type-2 fuzzy logic system (T2FLS) for the prediction of fire intensity and its risk assessment for risk reduction in an underground coal mine. Recently, for the observation of underground coal mines, wireless underground sensor network (WUSN) are being concerned frequently. To implement this technique IT2FLS, main functional components are sensor nodes which are installed in coal mines to accumulate different imprecise environmental data like, temperature, relative humidity, different gas concentrations etc. and these are sent to a base station which is connected to the ground observation system through network. In the present context, a WUSN based fire monitoring system is developed using fuzzy logic approach to enhance the consistency in decision making system to improve the risk chances of fire during coal mining. We have taken Mamdani IT2FLS as fuzzy model on coal mine monitoring data to consider real-time decision making (DM). It is predicted from the simulated results that the recommended system is highly acceptable and amenable in the case of fire hazard safety with compared to the wired and off-line monitoring system for UMC. Legitimacy of the suggested model is prepared using statistical analysis and multiple linear regression analysis. 展开更多
关键词 Type-2 fuzzy logic UNDERGROUND coal mining system MINE environment FIRE and risk monitoring of MINE WIRELESS sensor networks FIRE Intensity
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Implementation of remote monitoring system for prediction of tool wear and failure using ART2 被引量:3
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作者 NOH Min-Seok HONG Dae Sun 《Journal of Central South University》 SCIE EI CAS 2011年第1期177-183,共7页
Remote monitoring of tools for prediction of tool wear in cutting processes was considered, and a method of implementation of a remote-monitoring system previously developed was proposed. Sensor signals were received ... Remote monitoring of tools for prediction of tool wear in cutting processes was considered, and a method of implementation of a remote-monitoring system previously developed was proposed. Sensor signals were received and tool wear was predicted in the local system using an ART2 algorithm, while the monitoring result was transferred to the remote system via intemet. The monitoring system was installed at an on-site machine tool for monitoring three kinds of tools cutting titanium alloys, and the tool wear was evaluated on the basis of vigilances, similarities between vibration signals received and the normal patterns previously trained. A number of experiments were carried out to evaluate the performance of the proposed system, and the results show that the wears of finishing-cut tools are successfully detected when the moving average vigilance becomes lower than the critical vigilance, thus the appropriate tool replacement time is notified before the breakage. 展开更多
关键词 tool wear remote monitoring system ART2 neural network machine tool tool replacement time
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Continuous glucose monitoring defined time-in-range is associated with sudomotor dysfunction in type 2 diabetes 被引量:4
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作者 Qing-Yu Guo Bin Lu +6 位作者 Zhan-Hong Guo Zhou-Qin Feng Yan-Yu Yuan Xu-Guang Jin Pu Zang Ping Gu Jia-Qing Shao 《World Journal of Diabetes》 SCIE CAS 2020年第11期489-500,共12页
BACKGROUND Time in range(TIR),as a novel metric for glycemic control,has robust relevance with diabetic complications.Diabetic peripheral neuropathy(DPN)is characterized by sudomotor dysfunction.AIM To explore the rel... BACKGROUND Time in range(TIR),as a novel metric for glycemic control,has robust relevance with diabetic complications.Diabetic peripheral neuropathy(DPN)is characterized by sudomotor dysfunction.AIM To explore the relationship between TIR obtained from continuous glucose monitoring(CGM)and sudomotor function detected by SUDOSCAN in subjects with type 2 diabetes.METHODS The research enrolled 466 inpatients with type 2 diabetes.All subjects underwent 3-d CGM and SUDOSCAN.SUDOSCAN was assessed with electrochemical skin conductance in hands(HESC)and feet(FESC).Average feet ESC<60μS was defined as sudomotor dysfunction(+),otherwise it was sudomotor dysfunction(-).TIR refers to the percentage of time when blood glucose is between 3.9-10 mmol/L during 1 d period.RESULTS Among the enrolled subjects,135(28.97%)presented with sudomotor dysfunction.Patients with sudomotor dysfunction(+)showed a decreased level of TIR(P<0.001).Compared to the lowest tertile of TIR,the middle and the highest tertiles of TIR was associated with an obviously lower prevalence of sudomotor dysfunction(20.51%and 21.94%vs 44.52%)(P<0.001).In addition,with the increase of TIR,HESC and FESC increased(P<0.001).Regression analysis demonstrated that TIR was inversely and independently linked with the prevalence of sudomotor dysfunction after adjusting for confounding values(odds ratio=0.979,95%CI:0.971-0.987,P<0.001).CONCLUSION The tight glycemic control assessed by TIR is of vitally protective value for sudomotor dysfunction in type 2 diabetes mellitus. 展开更多
关键词 Time in range Sudomotor dysfunction SUDOSCAN Diabetic peripheral neuropathy Continuous glucose monitoring Diabetes mellitus Type 2
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Accuracy of FreeStyle Libre flash glucose monitoring in patients with type 2 diabetes who migrated from highlands to plains 被引量:2
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作者 Zeng-Mei Sun Yuan-Ze Du +11 位作者 Su-Yuan Wang Shu-Yao Sun Yan Ye Xue-Ping Sun Ming-Xia Li Hua He Wun-Chun Long Cheng-Hui Zhang Xuan-Yu Yao Wu-Yi Fan Ling Wang Yun-Hong Wu 《World Journal of Diabetes》 SCIE 2024年第6期1254-1262,共9页
BACKGROUND The FreeStyle Libre flash glucose monitoring(FGM)system entered the Chinese market in 2017 to complement the self-monitoring of blood glucose.Due to its increased usage in clinics,the number of studies inve... BACKGROUND The FreeStyle Libre flash glucose monitoring(FGM)system entered the Chinese market in 2017 to complement the self-monitoring of blood glucose.Due to its increased usage in clinics,the number of studies investigating its accuracy has increased.However,its accuracy has not been investigated in highland populations in China.AIM To evaluate measurements recorded using the FreeStyle Libre FGM system compared with capillary blood glucose measured using the enzyme electrode method in patients with type 2 diabetes(T2D)who had migrated within 3 mo from highlands to plains.METHODS Overall,68 patients with T2D,selected from those who had recently migrated from highlands to plains(within 3 mo),were hospitalized at the Department of Endocrinology from August to October 2017 and underwent continuous glucose monitoring(CGM)with the FreeStyle Libre FGM system for 14 d.Throughout the study period,fingertip capillary blood glucose was measured daily using the enzyme electrode method(Super GL,China),and blood glucose levels were read from the scanning probe during fasting and 2 h after all three meals.Moreover,the time interval between reading the data from the scanning probe and collecting fingertip capillary blood was controlled to<5 min.The accuracy of the FGM system was evaluated according to the CGM guidelines.Subsequently,the factors influencing the mean absolute relative difference(MARD)of this system were analyzed by a multiple linear regression method.RESULTS Pearson’s correlation analysis showed that the fingertip and scanned glucose levels were positively correlated(R=0.86,P=0.00).The aggregated MARD of scanned glucose was 14.28±13.40%.Parker's error analysis showed that 99.30%of the data pairs were located in areas A and B.According to the probe wear time of the FreeStyle Libre FGM system,MARD_(1 d) and MARD_(2-14 d) were 16.55%and 14.35%,respectively(t=1.23,P=0.22).Multiple stepwise regression analysis showed that MARD did not correlate with blood glucose when the largest amplitude of glycemic excursion(LAGE)was<5.80 mmol/L but negatively correlated with blood glucose when the LAGE was≥5.80 mmol/L.CONCLUSION The FreeStyle Libre FGM system has good accuracy in patients with T2D who had recently migrated from highlands to plains.This system might be ideal for avoiding the effects of high hematocrit on blood glucose monitoring in populations that recently migrated to plains.MARD is mainly influenced by glucose levels and fluctuations,and the accuracy of the system is higher when the blood glucose fluctuation is small.In case of higher blood glucose level fluctuations,deviation in the scanned glucose levels is the highest at extremely low blood glucose levels. 展开更多
关键词 Type 2 diabetes Flash glucose monitoring ACCURACY Continuous glucose monitor High altitude
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Multilayered PdTe_(2)/thin Si heterostructures as self-powered flexible photodetectors with heart rate monitoring ability 被引量:1
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作者 Chengyun Dong Xiang An +4 位作者 Zhicheng Wu Zhiguo Zhu Chao Xie Jian-An Huang Linbao Luo 《Journal of Semiconductors》 EI CAS CSCD 2023年第11期42-51,共10页
Two-dimensional layered material/semiconductor heterostructures have emerged as a category of fascinating architectures for developing highly efficient and low-cost photodetection devices.Herein,we present the constru... Two-dimensional layered material/semiconductor heterostructures have emerged as a category of fascinating architectures for developing highly efficient and low-cost photodetection devices.Herein,we present the construction of a highly efficient flexible light detector operating in the visible-near infrared wavelength regime by integrating a PdTe2 multilayer on a thin Si film.A representative device achieves a good photoresponse performance at zero bias including a sizeable current on/off ratio exceeding 105,a decent responsivity of~343 mA/W,a respectable specific detectivity of~2.56×10^(12)Jones,and a rapid response time of 4.5/379μs,under 730 nm light irradiation.The detector also displays an outstanding long-term air stability and operational durability.In addition,thanks to the excellent flexibility,the device can retain its prominent photodetection performance at various bending radii of curvature and upon hundreds of bending tests.Furthermore,the large responsivity and rapid response speed endow the photodetector with the ability to accurately probe heart rate,suggesting a possible application in the area of flexible and wearable health monitoring. 展开更多
关键词 2D layered material HETEROSTRUCTURE FLEXIBLE PHOTODETECTOR health monitoring
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Parsimonious Model for Blood Glucose Level Monitoring in Type 2 Diabetes patients 被引量:2
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作者 ZHAO Fang MA Yan Fen +3 位作者 WEN Jing Xiao DU Yan Fang LI Chun Lin LI Guang Wei 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2014年第7期559-563,共5页
To establish the parsimonious model for blood glucose monitoring in patients with type 2 diabetes receiving oral hypoglycemic agent treatment. One hundred and fifty-nine adult Chinese type 2 diabetes patients were ran... To establish the parsimonious model for blood glucose monitoring in patients with type 2 diabetes receiving oral hypoglycemic agent treatment. One hundred and fifty-nine adult Chinese type 2 diabetes patients were randomized to receive rapid-acting or sustained-release gliclazide therapy for 12 weeks. 展开更多
关键词 SMBG HBALC Parsimonious Model for Blood Glucose Level monitoring in Type 2 Diabetes patients
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Improving atmospheric CO_(2)retrieval based on the collaborative use of Greenhouse gases Monitoring Instrument and Directional Polarimetric Camera sensors on Chinese hyperspectral satellite GF5-02 被引量:1
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作者 Hanhan Ye Hailiang Shi +7 位作者 Xianhua Wang Erchang Sun Chao Li Yuan An Shichao Wu Wei Xiong Zhengqiang Li Jochen Landgraf 《Geo-Spatial Information Science》 CSCD 2024年第3期572-584,共13页
The Greenhouse Gas Monitoring Instrument(GMI)onboard the Chinese hyperspectral satellite GF5-02 can provide abundant observations of global atmospheric CO_(2),which plays an important role in climate research.CO_(2)re... The Greenhouse Gas Monitoring Instrument(GMI)onboard the Chinese hyperspectral satellite GF5-02 can provide abundant observations of global atmospheric CO_(2),which plays an important role in climate research.CO_(2)retrieval precision is the key to determining the application value of the GMI.To reduce the influence of atmospheric scattering on retrieval,we combined the Directional Polarimetric Camera(DPC)data on the same satellite to improve the anti-interference ability of GMI CO_(2)retrieval and ensure its retrieval precision.To realize the reliability and feasibility of the collaborative use of the GMI and DPC,this paper designs the pointing registration method of the GMI based on coastline observations,the spatial resolution matching method and the collaborative cloud screening method of the GMI and DPC observations.Combined with the DPC,which supplied the spectral data and aerosol product,the retrieval ability of the coupled bidirectional reflectance distribution function CO_(2)retrieval(CBCR)method developed for GMI CO_(2)retrieval was improved,with the retrieval efficiency of CO_(2)products increasing by 27%,and the CO_(2)retrieval precision increasing from 3.3 ppm to 2.7 ppm.Moreover,collaborative use not only guaranteed the GMI’s ability to detect global and area CO_(2)concentration distribution characteristics,such as significant concentration differences between the Northern and Southern Hemispheres in winter and high CO_(2)concentrations in urban agglomeration areas caused by human activities,but also extended the GMI’s potential for monitoring anomalous events,such as the Tonga volcanic eruption. 展开更多
关键词 CO_(2)retrieval Greenhouse Gas monitoring Instrument(GMI) Directional Polarimetric Camera(DPC) collaborative use
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Drone-Based IoT Monitoring of Urban CO₂Levels in Makassar:Spatio-Temporal Analysis Across Varying Heights
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作者 Putri Ida Sunaryathy Samad Dewiani Jamaluddin +1 位作者 Alimuddin Sa’ban Miru Mithen Lullulangi 《Journal of Environmental & Earth Sciences》 2025年第8期317-332,共16页
Urban air quality degradation from rising CO_(2) is acute in rapidly developing tropical cities such as Makassar,Indonesia.We deploy a drone-based Internet of Things(IoT)platform for real-time CO_(2) monitoring,integr... Urban air quality degradation from rising CO_(2) is acute in rapidly developing tropical cities such as Makassar,Indonesia.We deploy a drone-based Internet of Things(IoT)platform for real-time CO_(2) monitoring,integrating low-cost sensors(NDIR,MQ135,MG811)on a DJI Phantom 4 with cloud streaming to Firebase.Measurements were collected at five sites,namely Jl.AP.Pettarani,Jl.Ahmad Yani,Jl.Sultan Hasanuddin,Jl.Nusantara,and KIMA at 08:00,12:00,and 16:00 in September 2024 while vertically profiling 1-20 m with three repeat flights per site and time.Descriptive statistics and one-way ANOVA with Tukey HSD assessed spatio-temporal differences;Pearson correlation quantified cross-sensor agreement.Results show marked spatial and diurnal variability:Jl.AP.Pettarani exhibits the highest mean concentration(442.5 ppm),likely due to flyover-induced trapping,whereas Jl.Ahmad Yani records the lowest(390.0 ppm).Vertical profiles reveal mid-altitude peaks in street-canyon and industrial settings,and dilution with height in greener areas,indicating ventilation contrasts.Preprocessing removed outliers and applied temperature-humidity corrections to low-cost sensors.Differences across locations and times are statistically significant(p<0.05),and cross-sensor correlations are strong(r≈0.88-0.96)after correction.Compared with fixed ground stations,the system provides fine-scale three-dimensional coverage and real-time visualization useful for field decisions.Limitations include payload-constrained endurance and intermittent data loss in obstructed areas.Findings support targeted interventions,improving canyon ventilation around flyovers and expanding urban greenery relevant to Makassar and similar tropical cities. 展开更多
关键词 CO_(2)monitoring Drone-Based IoT Urban Air Quality Makassar Spatio-Temporal Analysis
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Preliminary Validation of Transcutaneous CO<sub>2</sub>Monitoring in Patients Undergoing Cardiac Ablation Using Jet Ventilation
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作者 Zvi C. Jacob Roger Fan +2 位作者 Ruth A. Reinsel Nehul Patel Arvind Chandrakantan 《Open Journal of Anesthesiology》 2017年第9期315-327,共13页
Objectives: There is no data in the current medical literature on efficacy or accuracy of transcutaneous (tcPCO2) monitoring during jet ventilation for cardiac ablation. The use of tcPCO2 during cardiac ablation proce... Objectives: There is no data in the current medical literature on efficacy or accuracy of transcutaneous (tcPCO2) monitoring during jet ventilation for cardiac ablation. The use of tcPCO2 during cardiac ablation procedures offers the opportunity to compare end-tidal and transcutaneous methods of CO2 measurement before and after the use of the jet ventilation. Comparison of these measurements with arterial blood gas CO2 levels allows evaluation of the accuracy of the tcPCO2 technique for use during jet ventilation. Design: Observational study;patients served as their own controls. Setting: Cardiac electrophysiology laboratory. Participants: 15 adult patients (9 M), ASA III-IV, aged 26 to 82 years (median 66 years) undergoing radiofrequency ablation for atrial fibrillation. Interventions: Jet ventilation (JV) versus conventional ventilation. Measurements and Main Results: Paired measurements of end-tidal CO2 (EtCO2) and transcutaneous CO2 (tcPCO2) were recorded during periods of conventional ventilation. Paired measurements of arterial blood CO2 (PaCO2) levels and tcPCO2 were recorded during JV. ABG samples were drawn at the anesthesiologist’s discretion to assess the patient’s respiratory status. The level of agreement between the three methods was compared using the Bland Altman plot. We found that tcPCO2 values consistently provided a close approximation to PaCO2 levels. The mean difference between tcPCO2 and EtCO2 values in baseline and post-JV was on the order of 3 - 5 mmHg, with standard deviation of 4 - 6 mmHg. This is well within the range of variability that is accepted in clinical practice. Conclusions: These preliminary results suggest that tcPCO2 provides an acceptable estimate of CO2 concentration in arterial blood during JV, as well as prior to and following JV. 展开更多
关键词 High Frequency Jet Ventilation CARDIAC Ablation TRANSCUTANEOUS co2 monitoring end-tidal co2 monitoring General Anesthesia
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Utility of short-term telemetry heart rhythm monitoring and CHA2DS2-VASc stratification in patients presenting with suspected cerebrovascular accident
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作者 Tanzim Bhuiya Sherif Roman +3 位作者 Taner Aydin Bhakti Patel Roman Zeltser Amgad N Makaryus 《World Journal of Cardiology》 2023年第2期56-63,共8页
BACKGROUND Inpatient telemetry heart rhythm monitoring overuse has been linked to higher healthcare costs.AIM To evaluate if CHA2DS2-VASc score could be used to indicate if a patient admitted with possible cerebrovasc... BACKGROUND Inpatient telemetry heart rhythm monitoring overuse has been linked to higher healthcare costs.AIM To evaluate if CHA2DS2-VASc score could be used to indicate if a patient admitted with possible cerebrovascular accident(CVA)or transient ischemic attack(TIA)requires inpatient telemetry monitoring.METHODS A total of 257 patients presenting with CVA or TIA and placed on telemetry monitoring were analyzed retrospectively.We investigated the utility of telemetry monitoring to diagnose atrial fibrillation/flutter and the CHA2DS2-VASc scoring tool to stratify the risk of having CVA/TIA in these patients.RESULTS In our study population,63(24.5%)of the patients with CVA/TIA and telemetry monitoring were determined to have no ischemic neurologic event.Of the 194(75.5)patients that had a confirmed CVA/TIA,only 6(2.3%)had an arrhythmia detected during their inpatient telemetry monitoring period.Individuals with a confirmed CVA/TIA had a statistically significant higher CHA2DS2-VASc score compared to individuals without an ischemic event(3.59 vs 2.61,P<0.001).CONCLUSION Given the low percentage of inpatient arrhythmias identified,further research should focus on discretionary use of inpatient telemetry on higher risk patients to diagnose the arrhythmias commonly leading to CVA/TIA.A prospective study assessing event rate of CVA/TIA in patients with higher CHA2DS2-VASc score should be performed to validate the CHA2DS2-VASc score as a possible risk stratifying tool for patients at risk for CVA/TIA. 展开更多
关键词 Telemetry monitoring CHA2DS2-VASc score ARRHYTHMIA Atrial fibrillation
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Robust monitoring machine:a machine learning solution for out‑of‑sample R_(2)‑hacking in return predictability monitoring
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作者 James Yae Yang Luo 《Financial Innovation》 2023年第1期2701-2728,共28页
The out-of-sample R^(2) is designed to measure forecasting performance without look-ahead bias.However,researchers can hack this performance metric even without multiple tests by constructing a prediction model using ... The out-of-sample R^(2) is designed to measure forecasting performance without look-ahead bias.However,researchers can hack this performance metric even without multiple tests by constructing a prediction model using the intuition derived from empirical properties that appear only in the test sample.Using ensemble machine learning techniques,we create a virtual environment that prevents researchers from peeking into the intuition in advance when performing out-of-sample prediction simulations.We apply this approach to robust monitoring,exploiting a dynamic shrink-age effect by switching between a proposed forecast and a benchmark.Considering stock return forecasting as an example,we show that the resulting robust monitoring forecast improves the average performance of the proposed forecast by 15%(in terms of mean-squared-error)and reduces the variance of its relative performance by 46%while avoiding the out-of-sample R^(2)-hacking problem.Our approach,as a final touch,can further enhance the performance and stability of forecasts from any models and methods. 展开更多
关键词 Machine learning Out-of-sample R^(2)-hacking Return predictability monitoring
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Application and prospects of spatial information technology in CO_(2)sequestration monitoring
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作者 LYU Weifeng LI Yushu +4 位作者 WANG Mingyuan LIN Qianguo JIA Ninghong JI Zemin HE Chang 《Petroleum Exploration and Development》 SCIE 2024年第3期727-740,共14页
This paper systematically reviews the current applications of various spatial information technologies in CO_(2)sequestration monitoring,analyzes the challenges faced by spatial information technologies in CO_(2)seque... This paper systematically reviews the current applications of various spatial information technologies in CO_(2)sequestration monitoring,analyzes the challenges faced by spatial information technologies in CO_(2)sequestration monitoring,and prospects the development of spatial information technologies in CO_(2)sequestration monitoring.Currently,the spatial information technologies applied in CO_(2)sequestration monitoring mainly include five categories:eddy covariance method,remote sensing technology,geographic information system,Internet of Things technology,and global navigation satellite system.These technologies are involved in three aspects:monitoring data acquisition,positioning and data transmission,and data management and decision support.Challenges faced by the spatial information technologies in CO_(2)sequestration monitoring include:selecting spatial information technologies that match different monitoring purposes,different platforms,and different monitoring sites;establishing effective data storage and computing capabilities to cope with the broad sources and large volumes of monitoring data;and promoting collaborative operations by interacting and validating spatial information technologies with mature monitoring technologies.In the future,it is necessary to establish methods and standards for designing spatial information technology monitoring schemes,develop collaborative application methods for cross-scale monitoring technologies,integrate spatial information technologies with artificial intelligence and high-performance computing technologies,and accelerate the application of spatial information technologies in carbon sequestration projects in China. 展开更多
关键词 CO_(2)geological sequestration CO_(2)sequestration monitoring spatial information technology CO_(2)leakage CCUS
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Exenatide once weekly combined with metformin reduced glycemic variability in type 2 diabetes by using flash glucose monitoring system
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作者 Yang Li Min-Min Han +5 位作者 Qiong He Zi-Ang Liu Dong Liang Jing-Tian Hou Yi Zhang Yun-Feng Liu 《World Journal of Diabetes》 SCIE 2020年第12期654-665,共12页
BACKGROUND Multiple studies demonstrate that fluctuating blood glucose level produces greater damage compared with sustained hyperglycemia.Flash glucose monitoring system is an effective method in documenting blood gl... BACKGROUND Multiple studies demonstrate that fluctuating blood glucose level produces greater damage compared with sustained hyperglycemia.Flash glucose monitoring system is an effective method in documenting blood glucose variability,contributing to better glucose management and reduced hypoglycemic event occurrence.AIM To investigate the improvement in glycemic variability(GV),blood glucose level,and metabolic indexes of patients with type 2 diabetes mellitus after combined treatment of exenatide once weekly(EXQW)and metformin.METHODS Twenty-five patients with type 2 diabetes mellitus suffering from poor blood glucose control under metformin treatment were recruited.The recruited patients were prescribed with oral metformin only(maintaining a dosage of metformin at≥1500 mg/day)for 2 wk(screening period),and then given EXQW(2 mg,subcutaneous injection)for 12 wk(experimental period).The flash glucose monitoring system was used to document blood glucose values during the screening period and the last 2 wk of the experimental period.RESULTS Four patients were excluded for various reasons,yielding a total of 21 patients,including 17 males and 4 females,with an average age of 48.8 years,who completed this study.The estimated glycated hemoglobin,mean blood glucose,fasting and postprandial blood glucose levels,and percentage of blood glucose above 7.8 mmol/L decreased compared to those at baseline(P=0.003,0.003,0.008,0.010,0.014,0.017,and 0.005,respectively),while the percentage of blood glucose between 3.9 and 7.8 mmol/L significantly increased(P=0.005).Parameters of GV including standard deviation of blood glucose,mean amplitude of glycemic excursions,mean of daily difference,area under the curve difference between percentiles 25 and 75,and area under the curve difference between percentiles 10 and 90 were significantly lower compared to that of baseline(P=0.017,0.006,0.000,0.024,0.036,respectively).The durations of blood glucose below 3.9 mmol/L during the day and nocturnal periods significantly increased after treatment(P=0.041 and 0.028,respectively),but there was no significant increase in severe hypoglycemia(<3.0 mmol/L)compared with that at baseline(P=0.207).In addition,some metabolic indicators improved after EXQW treatment.CONCLUSION EXQW combined with metformin can effectively improve blood glucose levels,reduce GV,and improve metabolic indicators.However,there is still a risk of nocturnal hypoglycemia,and careful attention should be paid to patients with EXQW treatment. 展开更多
关键词 Flash glucose monitoring Glycemic variability Type 2 diabetes mellitus Exenatide once weekly
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Potential of eNose Technology for Monitoring Biological CO_(2) Conversion Processes
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作者 Muhammad Awais Syed Muhammad Zaigham Abbas Naqvi +5 位作者 Sami Ullah Khan MIjaz Khan Sherzod Abdullaev Junfeng Wu Wei Zhang Jiandong Hu 《Transactions of Tianjin University》 EI CAS 2024年第5期381-394,共14页
Electronic nose(eNose) is a modern bioelectronic sensor for monitoring biological processes that convert CO_(2) into valueadded products, such as products formed during photosynthesis and microbial fermentation. eNose... Electronic nose(eNose) is a modern bioelectronic sensor for monitoring biological processes that convert CO_(2) into valueadded products, such as products formed during photosynthesis and microbial fermentation. eNose technology uses an array of sensors to detect and quantify gases, including CO_(2), in the air. This study briefly introduces the concept of eNose technology and potential applications thereof in monitoring CO_(2) conversion processes. It also provides background information on biological CO_(2) conversion processes. Furthermore, the working principles of eNose technology vis-à-vis gas detection are discussed along with its advantages and limitations versus traditional monitoring methods. This study also provides case studies that have used this technology for monitoring biological CO_(2) conversion processes. eNose-predicted measurements were observed to be completely aligned with biological parameters for R~2 values of 0.864, 0.808, 0.802, and 0.948. We test eNose technology in a variety of biological settings, such as algae farms or bioreactors, to determine its effectiveness in monitoring CO_(2) conversion processes. We also explore the potential benefits of employing this technology vis-à-vis monitoring biological CO_(2) conversion processes, such as increased reaction efficiency and reduced costs versus traditional monitoring methods. Moreover, future directions and challenges of using this technology in CO_(2) capture and conversion have been discussed. Overall, we believe this study would contribute to developing new and innovative methods for monitoring biological CO_(2) conversion processes and mitigating climate change. 展开更多
关键词 Electronic nose(eNose) CO_(2) conversion Biological monitoring Gas detection Bioelectronic nose
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Research on P2P Traffic Monitoring System based on DPI Technology
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作者 Zhiqiang Ma 《International Journal of Technology Management》 2014年第9期85-87,共3页
This paper focuses on the key technologies of P2P technology and network traffic monitoring, which focuses on AC automaton and bypass interference control technology, and on based of it, we design a new P2P traffic mo... This paper focuses on the key technologies of P2P technology and network traffic monitoring, which focuses on AC automaton and bypass interference control technology, and on based of it, we design a new P2P traffic monitoring system. The system uses DPI and DFI recognition technology, as well as straight loss and bypass interference control technology, basically meet the recognition and control of P2P traffic. Finally, the test results show that this system recognition accuracy of P2P traffic is high, good control effect, function and performance meet the design requirements. 展开更多
关键词 monitoring system network traffic traffic monitoring P2P traffic monitoring
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