This paper introduces part of the content in the association standard,T/CAAM0002–2020 Nomenclature and Location of Acupuncture Points for Laboratory Animals Part 3:Mouse.This standard was released by the China Associ...This paper introduces part of the content in the association standard,T/CAAM0002–2020 Nomenclature and Location of Acupuncture Points for Laboratory Animals Part 3:Mouse.This standard was released by the China Association of Acupuncture and Moxibustion on May 15,2020,implemented on October 31,2020,and published by Standards Press of China.The standard was drafted by the Institute of Acupuncture and Moxibustion,China Academy of Chinese Medical Sciences,and the Nanjing University of Chinese Medicine.Principal draftsmen:Xiang-hong JING and Xing-bang HUA.Participating draftsmen:Wan-zhu BAI,Bin XU,Dong-sheng XU,Yi GUO,Tie-ming MA,Xin-jun WANG,and Sheng-feng LU.展开更多
Objective The analgesic effect of acupuncture has been widely accepted.Nevertheless,the mechanism behind its analgesic effect remains elusive,thus impeding the progress of research geared toward enhancing the analgesi...Objective The analgesic effect of acupuncture has been widely accepted.Nevertheless,the mechanism behind its analgesic effect remains elusive,thus impeding the progress of research geared toward enhancing the analgesic effect of acupuncture.This paper investigated the role of acupuncture needle surface textures on acupuncture’s analgesic effect by creating four experimental acupuncture needles with different patterns of surface augmentation.Methods Four types of acupuncture needles with different surface textures(the lined needle,circle needle,sandpaper needle,and threaded needle)were designed.Additionally,the force/torque measurement system used a robot arm and mechanical sensor to measure the force on the needle during insertion and manipulation.To perform acupuncture analgesia experiments,four experimental acupuncture needles and a normal needle were inserted into the Zusanli(ST36)acupoint of rats with inflammatory pain.By comparing the force and torque and the analgesic efficacy of the different acupuncture needles,these experiments tested the role of acupuncture needle body texture on acupuncture analgesia.Results The analgesic effects of different acupuncture needle body textures varied.Specifically,the force required to penetrate the skin with the lined needle was not greater than that for the normal needle;however,the needle with inscribed circles and the sandpaper-roughened needle both required greater force for insertion.Additionally,the torque of the lined needle reached 2×10^(-4)N·m under twisting manipulation,which was four times greater the torque of a normal needle(5×10^(-5)N·m).Furthermore,the lined needle improved pain threshold and mast cell degranulation rate compared to the normal needle.Conclusion Optimizing the texture of acupuncture needles can enhance acupuncture analgesia.The texture of our experimental acupuncture needles had a significant impact on the force needed to penetrate the skin and the torque needed to manipulate the needle;it was also linked to variable analgesic effects.This study provides a theoretical basis for enhancing the analgesic efficacy of acupuncture through the modification of needles and promoting the development of acupuncture therapy.展开更多
This paper introduces part of the content in the association standard,T/CAAM0002–2020 Nomenclature and Location of Acupuncture Points for Laboratory Animals Part 2:Rat.This standard was released by the China Associat...This paper introduces part of the content in the association standard,T/CAAM0002–2020 Nomenclature and Location of Acupuncture Points for Laboratory Animals Part 2:Rat.This standard was released by the China Association of Acupuncture and Moxibustion on May 15,2020,implemented on October 31,2020,and published by Standards Press of China.The standard was drafted by the Institute of Acupuncture and Moxibustion,China Academy of Chinese Medical Sciences,and the Nanjing University of Chinese Medicine.Principal draftsmen:Xiang-hong JING and Xing-bang HUA.Participating draftsmen:Wan-Zhu BAI,Bin XU,Dong-sheng XU,Yi GUO,Tie-ming MA,Xin-jun WANG,and Sheng-feng LU.展开更多
OBJECTIVE:To assess the efficacy and safety of the Qingyanyin formulated granules(轻燕饮配方颗粒,QYY),press needles(PN),and their combined application in addressing abdominal obesity(AO).This trial aims to offer a mor...OBJECTIVE:To assess the efficacy and safety of the Qingyanyin formulated granules(轻燕饮配方颗粒,QYY),press needles(PN),and their combined application in addressing abdominal obesity(AO).This trial aims to offer a more scientifically grounded therapeutic regimen for clinical interventions.METHODS:From March 2021 to July 2021,a multicenter,triple-blind,randomized 2×2 factorial design clinical trial was conducted across 7 centers in 4 major cities within China's mainland.The trial participants were patients diagnosed with AO.The trial followed a 1∶1∶1∶1 random allocation ratio,assigning participants to one of four groups:QYY placebo plus simulated press needles(SPN)(placebo+SPN),QYY plus SPN(QYY+SPN),QYY placebo plus PN(placebo+PN),and QYY plus PN(QYY+PN).The trial participants received treatment for 12 weeks.Observe the changes in waist circumference,body weight,body mass index(BMI),Beck Depression Inventory(BDI),Beck Anxiety Inventory(BAI)scores,and Pittsburgh Sleep Quality Index(PSQI)before and after treatment.RESULTS:The QYY+PN group exhibited significant improvements in waist circumference compared to placebo+PN[Difference=-1.59,95%CI(-3.03,-0.16)]and placebo+SPN groups[Difference=-2.01,95%CI(-3.46,-0.57)].QYY+PN demonstrated a significant advantage over placebo+SPN[Difference=-2.01,95%CI(-3.46,-0.57)],and no statistically significant interaction was observed between the two interventions(P>0.05).In terms of weight and BMI improvements,the QYY+PN,QYY+SPN,and the PN+placebo groups all experienced trending greater reductions in weight compared to the placebo group.In terms of the total scores of PSQI,BAI,and BDI,all four groups exhibited improvements compared to the baseline.Specifically,concerning the change in total PSQI scores,the QYY+PN group exhibited a greater reduction;Regarding the change in total BAI scores,the PN+placebo group demonstrated a greater decrease;As for the change in total BDI scores,the QYY+SPN group displayed a greater reduction.CONCLUSION:This study confirmed that QYY+PN can effectively reduce the waist circumference of patients with AO.Furthermore,the combined approach offers greater benefits than either treatment alone,all without any reported serious adverse events.展开更多
Unmanned aerial vehicle(UAV)swarm network consisting of a collection of micro UAVs can be used for many applications.It is well established that packet routing is a fundamental problem to achieve UAV collaboration.How...Unmanned aerial vehicle(UAV)swarm network consisting of a collection of micro UAVs can be used for many applications.It is well established that packet routing is a fundamental problem to achieve UAV collaboration.However,the highly dynamic nature of UAVs,frequently changing network topologies and security issues,poses significant challenges to packet forwarding in UAV networks.The existing topology-based routing protocols are not well suited in UAV network due to their high controlling overhead or excessive end-to-end delay.Geographic routing is regarded as a promising solution,as it only requires local information.In order to enhance the accuracy and security of geographic routing in highly dynamic UAV network,in this paper,we propose a new predictive geographic(PGeo)routing strategy with location verification.First,a detection mechanism is adopted to recognize malicious UAVs falsifying their location.Then,an accurate average service time of a packet in the medium access control(MAC)layer is derived to assist location prediction.The proposed delay model can provide a theoretical basis for future work,and our simulation results reveal that PGeo outstrips the existing geographic routing protocols in terms of packet delivery ratio in the presence of location spoofing behavior.展开更多
BACKGROUND This is a randomized study to compare the diagnostic accuracy of endoscopic ultrasound(EUS)-guided sampling of pancreatic solid lesions obtained with the 22-gauge Franseen(EUS-fine needle biopsy)vs the 22-g...BACKGROUND This is a randomized study to compare the diagnostic accuracy of endoscopic ultrasound(EUS)-guided sampling of pancreatic solid lesions obtained with the 22-gauge Franseen(EUS-fine needle biopsy)vs the 22-gauge standard needle(EUS-fine needle aspiration)without rapid onsite evaluation(ROSE),since,in most endoscopy units around the world ROSE is not routinely available.AIM To investigate the accuracy of EUS-guided sampling of pancreatic solid lesions obtained between two different needles without ROSE.METHODS Patients with a solid pancreatic were included.Patients were biopsied in a randomized order.The primary endpoint was the diagnostic sensitivity for pancreatic malignancy(PM).Secondary outcomes were adequacy of the sample,the mean tissue area,the mean tumor area,and the adverse event rate.RESULTS The final diagnosis was pancreatic adenocarcinoma in 38(76%),neuroendocrine tumor in 4(8%),chronic pancreatitis in 3(6%)patients.The sensitivity for PM with Franseen needle was 0.91[95%confidence interval(CI):0.80-0.98],vs 0.8(95%CI:0.67-0.91)(P=0.025)with standard needle.The specificity for PM did not differentiate.The accuracy of the standard needle for PM was 0.80(95%CI:0.66-0.90),and the Franseen group was 0.90(95%CI:0.78-0.97)(P=0.074).The technical success rates for the standard and Franseen needle groups were 94%(95%CI:0.83-0.99)and 100%(95%CI:0.92-1.00),respectively.The mean total tissue area in mm2(SD)was greater in the Franseen group,2.07(0.22)vs 1.16(0.17)(P<0.01).The mean tumor area in mm2(SD)was not different in Franseen group vs standard group,0.42(0.09)vs 0.47(0.09)(P=0.80).There were no adverse events.CONCLUSION The sensitivity for PM and mean total tissue area,was greater in the as compared with standard needle.The mean tumor area did not differ between the groups.展开更多
A novel method is developed by utilizing the fractional frequency based multirange rulers to precisely position the passive inter-modulation(PIM)sources within radio frequency(RF)cables.The proposed method employs a s...A novel method is developed by utilizing the fractional frequency based multirange rulers to precisely position the passive inter-modulation(PIM)sources within radio frequency(RF)cables.The proposed method employs a set of fractional frequencies to create multiple measuring rulers with different metric ranges to determine the values of the tens,ones,tenths,and hundredths digits of the distance.Among these rulers,the one with the lowest frequency determines the maximum metric range,while the one with the highest frequency decides the highest achievable accuracy of the position system.For all rulers,the metric accuracy is uniquely determined by the phase accuracy of the detected PIM signals.With the all-phase Fourier transform method,the phases of the PIM signals at all fractional frequencies maintain almost the same accuracy,approximately 1°(about 1/360 wavelength in the positioning accuracy)at the signal-to-noise ratio(SNR)of 10 d B.Numerical simulations verify the effectiveness of the proposed method,improving the positioning accuracy of the cable PIM up to a millimeter level with the highest fractional frequency operating at 200 MHz.展开更多
Semiconductor electronic devices are prone to charge accumulation during production and transportation,which usually causes device breakdown.Ionizers are widely used for electrostatic elimination,and utilizing semicon...Semiconductor electronic devices are prone to charge accumulation during production and transportation,which usually causes device breakdown.Ionizers are widely used for electrostatic elimination,and utilizing semiconductor silicon for the discharge needle material in ionizers can effectively prevent metal contamination.To investigate the discharge characteristics of silicon needles and their mode modulation mechanism,this study has established an experimental platform for silicon needle-plate discharge under positive polarity voltage.Discharge pulse parameters and optical signals were measured at varying electrode spacings.The experimental results reveal that silicon needle discharge progresses through four regimes:the spontaneous streamer,the periodic streamer,the cluster streamer,and the glow discharge.Among these,the pulse amplitude is most uniform and stable in the periodic streamer regime.In addition,shorter-gap discharge exhibits higher pulse amplitude and repetition frequency but is easier to transition into the filament regime.The formation process of a single pulse is closely related to the field strength in the ionization region near the needle tip.Hence,parameters such as the pulse rising edge time and falling edge time show minimal variation with voltage.The amount of charge generated per unit time is primarily influenced by the repetition frequency.Consequently,the electrostatic ionizer produces the highest,most stable,and most uniform charges if it operates in the periodic streamer regime.展开更多
Accurate and rapid determination of source locations is of great significance for surface microseismic monitoring.Traditional methods,such as diffraction stacking,are time-consuming and challenging for real-time monit...Accurate and rapid determination of source locations is of great significance for surface microseismic monitoring.Traditional methods,such as diffraction stacking,are time-consuming and challenging for real-time monitoring.In this study,we propose an approach to locate microseismic events using a deep learning algorithm with surface data.A fully convolutional network is designed to predict source locations.The input data is the waveform of a microseismic event,and the output consists of three 1D Gaussian distributions representing the probability distribution of the source location in the x,y,and z dimensions.The theoretical dataset is generated to train the model,and several data augmentation methods are applied to reduce discrepancies between the theoretical and field data.After applying the trained model to field data,the results demonstrate that our method is fast and achieves comparable location accuracy to the traditional diffraction stacking location method,making it promising for real-time microseismic monitoring.展开更多
Despite advances in surgery,chemotherapy,and radiotherapy,the treatment of colorectal cancer(CRC)requires more personalized approaches based on tumor biology and molecular profiling.While some relevant mutations have ...Despite advances in surgery,chemotherapy,and radiotherapy,the treatment of colorectal cancer(CRC)requires more personalized approaches based on tumor biology and molecular profiling.While some relevant mutations have been associated with differential response to immunotherapy,such as RAS and BRAF mutations limiting response to anti-epithelial growth factor receptor drugs or microsatellite instability predisposing susceptibility to immune checkpoint inhibitors,the role of inflammation in dictating tumor progression and treatment response is still under investigation.Several inflammatory biomarkers have been identified to guide patient prognosis.These include the neutrophil-lymphocyte ratio,Glasgow prognostic score(GPS)and its modified version,lymphocyte-Creactive protein ratio,and platelet-lymphocyte ratio.However,these markers are not yet included in the standard clinical management of patients with CRC,and further research is needed to evaluate their efficacy in different patient populations.A recent study by Wang et al,published in the World Journal of Gastroenterology,sheds light on the prognostic significance of pan-immune-inflammation value(PIV)in CRC,particularly concerning primary tumor location.Specifically,the authors found that a high PIV was strongly correlated with worse disease-free survival in patients with left-sided colon cancer,whereas no such association was observed in patients with right-sided colon cancer.Integrating tumor location into the prognostic assessment of CRC may improve our ability to more accurately identify high-risk patients and develop personalized treatment plans that are more likely to improve patient outcomes.展开更多
Data centers operate as physical digital infrastructure for generating,storing,computing,transmitting,and utilizing massive data and information,constituting the backbone of the flourishing digital economy across the ...Data centers operate as physical digital infrastructure for generating,storing,computing,transmitting,and utilizing massive data and information,constituting the backbone of the flourishing digital economy across the world.Given the lack of a consistent analysis for studying the locational factors of data centers and empirical deficiencies in longitudinal investigations on spatial dynamics of heterogeneous data centers,this paper develops a comprehensive analytical framework to examine the dynamic geographies and locational factors of techno-environmentally heterogeneous data centers across Chinese cities in the period of 2006–2021.First,we develop a“supply-demand-environment trinity”analytical framework as well as an accompanying evaluation indicator system with Chinese characteristics.Second,the dynamic geographies of data centers in Chinese cities over the last decades are characterized as spatial polarization in economically leading urban agglomerations alongside persistent interregional gaps across eastern,central,and western regions.Data centers present dual spatial expansion trajectories featuring outward radiation from eastern core urban agglomerations to adjacent peripheries and leapfrog diffusion to strategic central and western digital infrastructural hubs.Third,it is empirically verified that data center construction in Chinese cities over the last decades has been jointly influenced by supply-,demand-,and environment-side locational factors,echoing the efficacy of the trinity analytical framework.Overall,our findings demonstrate the temporal variance,contextual contingency,and attribute-based differentiation of locational factors underlying techno-environmentally heterogeneous data centers in Chinese cities.展开更多
Microseismic (MS) source location plays an important role in MS monitoring. This paper proposes a MS source location method based on particle swarm optimization (PSO) and multi-sensor arrays, where a free weight joint...Microseismic (MS) source location plays an important role in MS monitoring. This paper proposes a MS source location method based on particle swarm optimization (PSO) and multi-sensor arrays, where a free weight joints the P-wave first arrival data. This method adaptively adjusts the preference for “superior” arrays and leverages “inferior” arrays to escape local optima, thereby improving the location accuracy. The effectiveness and stability of this method were validated through synthetic tests, pencil-lead break (PLB) experiments, and mining engineering applications. Specifically, for synthetic tests with 1 μs Gaussian noise and 100 μs large noise in rock samples, the location error of the multi-sensor arrays jointed location method is only 0.30 cm, which improves location accuracy by 97.51% compared to that using a single sensor array. The average location error of PLB events on three surfaces of a rock sample is reduced by 48.95%, 26.40%, and 55.84%, respectively. For mine blast event tests, the average location error of the dual sensor arrays jointed method is 62.74 m, 54.32% and 14.29% lower than that using only sensor arrays 1 and 2, respectively. In summary, the proposed multi-sensor arrays jointed location method demonstrates good noise resistance, stability, and accuracy, providing a compelling new solution for MS location in relevant mining scenarios.展开更多
The study area is rich in shale gas resources and has reached the stage of comprehensive development. Shale gas extraction poses risks such as induced seismicity and well closure, compounded by the limited availabilit...The study area is rich in shale gas resources and has reached the stage of comprehensive development. Shale gas extraction poses risks such as induced seismicity and well closure, compounded by the limited availability of fi xed seismic monitoring stations nearby. To address these challenges, a dense observation array was developed within the study area to monitor and analyze microseismic activity during hydraulic fracturing. Microseismic events generated by hydraulic fracturing typically exhibit low amplitude and signal-to-noise ratio, rendering traditional manual analysis methods impractical. To overcome these limitations, an innovative artifi cial intelligence method combining picking-association-location (PAL) and match-expand- shift-stack (MESS) techniques (PALM) has been utilized for automated seismic detection. Numerous factors influence the accuracy of microseismic detection and localization. To evaluate these factors, the effects of various velocity structure models, instrument types, and station distributions on seismic location were analyzed and compared. The results indicate that the PALM method significantly mitigates the influence of velocity structure models on seismic location accuracy. Additionally, the use of broadband seismic instruments and a uniform station distribution enhances the precision of seismic location results. Furthermore, by integrating data from diff erent types of observation instruments, a comprehensive seismic catalog for the study area was established. These fi ndings not only enhance seismic location accuracy but also provide valuable guidance for optimizing regional seismic monitoring network design and improving seismic risk assessment.展开更多
We present a machine learning approach for earthquake location and magnitude estimation based on seismic arrival time patterns,using Histogram-Based Gradient Boosting for its high accuracy and computational efficiency...We present a machine learning approach for earthquake location and magnitude estimation based on seismic arrival time patterns,using Histogram-Based Gradient Boosting for its high accuracy and computational efficiency.The model is first evaluated using a synthetic earthquake bulletin that simulates realistic network geometry,station-event distributions,and incorporates a 3D velocity model for accurate travel-time compu-tation.Input features include P and S arrival times and amplitudes,while targets consist of location,origin time,magnitude,and uncertainty measures(horizontal and depth errors,azimuthal gap).Model performance is evaluated using𝑅2,Mean Absolute Error(MAE),and Median Absolute Error(MEDAE),demonstrating high accuracy across datasets with varying levels of completeness.Finally,we validate the model using real-world data from the Ahar-Varzaghan 2012 aftershock sequence in NW Iran.The model accurately recovers key spatial patterns of seismicity despite significant missing data,and the results align with previous high-resolution studies.These findings confirm that the proposed method generalizes well beyond synthetic settings and offers a fast,robust alternative for operational seismic networks and rapid hazard assessment.展开更多
The travel-time corrections for the primary seismic phases of 72 stations in the Guangdong seismic network,relative to the 1D South China travel-time model,were determined using joint hypocentral determination(JHD)and...The travel-time corrections for the primary seismic phases of 72 stations in the Guangdong seismic network,relative to the 1D South China travel-time model,were determined using joint hypocentral determination(JHD)and statistical analysis methods.The travel-time corrections for the Pg phase of 72 stations range between-0.25 s and 0.14 s,while the corrections for the Sg phase range between 0.27 s and 0.35 s,and those for the Pn phase are between-0.86 s and 0.07 s.The spatial distribution of travel-time corrections for Pg,Sg,and Pn phases of 72 stations correlates well with the geological structure in this region.This indicates that the travel-time corrections for Pg and Sg phases are mainly caused by the discrepancy between the actual crustal velocity structure beneath the stations and the 1D South China travel-time model.These corrections empirically compensate for systematic travel-time errors arising from such discrepancies.The primary factor contributing to the travel-time corrections for the Pn phase is the Moho undulations or tilt.These corrections are intended to compensate for systematic errors in travel time caused by variations in the actual Moho.By integrating the obtained travel-time corrections into the HYPO-SAT location algorithm,test results showed an obvious improvement in location accuracy and origin time precision for explosion events.The variation of horizontal distance between repeating earthquake pairs has also improved,with 86%of the repeating earthquake pair spacing being more accurately estimated after correction.This suggests the crucial significance of travel-time correction in earthquake location,and the consideration of travel-time correction exerts a notable impact on enhancing earthquake location accuracy.展开更多
Seismic source locations can characterize the spatial and temporal distributions of seismic sources,and can provide important basic data for earthquake disaster monitoring,fault activity characterization,and fracture ...Seismic source locations can characterize the spatial and temporal distributions of seismic sources,and can provide important basic data for earthquake disaster monitoring,fault activity characterization,and fracture growth interpretation.Waveform stacking-based location methods invert the source locations by focusing the source energy with multichannel waveforms,and these methods exhibit a high level of automation and noise-resistance.Taking the cross-correlation stacking(CCS)method as an example,this work attempts to study the influential factors of waveform stacking-based methods,and introduces a comprehensive performance evaluation scheme based on multiple parameters and indicators.The waveform data are from field monitoring of induced microseismicity in the Changning region(southern Sichuan Basin of China).Synthetic and field data tests reveal the impacts of three categories of factors on waveform stacking-based location:velocity model,monitoring array,and waveform complexity.The location performance is evaluated and further improved in terms of the source imaging resolution and location error.Denser array monitoring contributes to better constraining source depth and location reliability,but the combined impact of multiple factors,such as velocity model uncertainty and multiple seismic phases,increases the complexity of locating field microseismic events.Finally,the aspects of location uncertainty,phase detection,and artificial intelligencebased location are discussed.展开更多
Objective: To explore the effectiveness of applying an infusion project team in the safety risk management of indwelling needle use. Methods: A total of 200 patients who used intravenous indwelling needles during hosp...Objective: To explore the effectiveness of applying an infusion project team in the safety risk management of indwelling needle use. Methods: A total of 200 patients who used intravenous indwelling needles during hospital treatment from July to October 2022 were selected and randomly divided into an observation group and a control group, with 100 patients in each group. Patients in the control group received routine nursing methods, while those in the observation group were managed using the safety risk management method of the infusion project team. The tube blocking rate and tube removal rate were compared between the two groups. Results: The one-time puncture success rate and the standard implementation rate of intravenous indwelling needle use in the observation group were significantly higher than those in the control group. The total incidence of complications in the observation group was significantly lower than that in the control group, and patient satisfaction in the observation group was notably higher, with statistically significant differences (P < 0.05). Conclusion: The application of an infusion project team in the safety risk management of indwelling needle use is effective and has positive impacts on improving the one-time puncture success rate, the standard implementation rate of intravenous indwelling needle use, and patient satisfaction. It is a practice worth promoting in clinical settings.展开更多
Effective isolation between the cement sheath and the sandstone is crucial for the development and production of oil and gas wells in sandstone formations.In this study,a cement-sandstone composite(CSC)was prepared,an...Effective isolation between the cement sheath and the sandstone is crucial for the development and production of oil and gas wells in sandstone formations.In this study,a cement-sandstone composite(CSC)was prepared,and based onμ-CT three-dimensional reconstruction imaging and finite element analysis(FEA)techniques,the stress distribution and potential failure mechanism at the cement-sandstone bonding interface under axial loading were analyzed.The key findings are as follows:(1)stress concentrations are highly likely to form at the gap between the cement and sandstone interface and around interfacial voids,with Von Mises stress reaching critical levels of 18.0-20.0 MPa at these locations,significantly exceeding the stress magnitudes in well-bonded regions;(2)the phenomenon of local stress concentration driven by interfacial defects can be identified as the main basis for predicting damage location in interfacial debonding and continuous shear under axial load;(3)ensuring tight cementation at the cement-sandstone interface and minimizing interfacial voids are paramount for preventing stress-induced failure;(4)the critical Von Mises stress value of 20 MPa at the interface defect can be used as a benchmark for material selection and designed to ensure long-term integrity in oil and gas well applications subjected to similar axial loads.These findings contribute to a more accurate understanding of the failure mechanism of the cement-sandstone interface and to the precise design of material properties,thereby ensuring the long-term integrity of oil and gas well applications subjected to similar axial loads.展开更多
Double-shaft-driven needle punching machine is a specialized equipment designed for processing C/C crucible preforms.Its main needle punching module is operated by two sets of reciprocating crank-slider mechanisms.The...Double-shaft-driven needle punching machine is a specialized equipment designed for processing C/C crucible preforms.Its main needle punching module is operated by two sets of reciprocating crank-slider mechanisms.The intense vibration during needle punching not only generates huge noise,but also substantially reduces the quality of the preform.It is imperative to perform a dynamic analysis and optimization of the entire needle punching machine.In this paper,the three-dimensional(3D)model of the entire double-shaft-driven needle punching machine for C/C crucible preforms is established.Based on the modal analysis theory,the modal characteristics of the needle punching machine under various operating conditions are analyzed and its natural frequencies and vibration modes are determined.The harmonic response analysis is then employed to obtain the amplitude of the needle plate at different frequencies,and the structural weak points of the needle punching machine are identified and improved.The feasibility of the optimized scheme is subsequently reevaluated and verified.The results indicate that the first six natural frequencies of the machine increase,and the maximum amplitude of the needle plate decreases by 70.3%.The enhanced dynamic characteristics of the machine significantly improve its performance,enabling more efficient needle punching of C/C crucible preforms.展开更多
Objective:To investigate the efficacy and safety of combined spinal-epidural(CSE)anesthesia using a 25G spinal fine needle via a single puncture for lower limb surgery in children.Methods:Sixty pediatric patients sche...Objective:To investigate the efficacy and safety of combined spinal-epidural(CSE)anesthesia using a 25G spinal fine needle via a single puncture for lower limb surgery in children.Methods:Sixty pediatric patients scheduled for surgery were randomly divided into two groups,with 30 patients in each.The control group received subarachnoid anesthesia with 2–2.5 mL of 0.33%ropivacaine.The experimental group received the same ropivacaine dose,followed by withdrawal of the needle to the epidural space and administration of 0.1 mg hydromorphone diluted to 5 mL.The anesthetic and analgesic effects,incidence of complications,and postoperative family satisfaction were observed in both groups.Results:Compared with the control group,the experimental group showed a higher anesthesia success rate,a shorter onset time,and a longer maintenance time of anesthesia(p<0.05).Postoperative analgesia at various time points was significantly better in the experimental group(p<0.05).The total incidence of complications was lower in the experimental group,though the difference was not statistically significant(p>0.05).Family satisfaction was significantly higher in the experimental group(p<0.05).Conclusion:CSE anesthesia using a 25G fine needle via a single puncture for pediatric lower limb surgery is safe and effective.It can significantly improve surgical outcomes and is worthy of clinical promotion.展开更多
文摘This paper introduces part of the content in the association standard,T/CAAM0002–2020 Nomenclature and Location of Acupuncture Points for Laboratory Animals Part 3:Mouse.This standard was released by the China Association of Acupuncture and Moxibustion on May 15,2020,implemented on October 31,2020,and published by Standards Press of China.The standard was drafted by the Institute of Acupuncture and Moxibustion,China Academy of Chinese Medical Sciences,and the Nanjing University of Chinese Medicine.Principal draftsmen:Xiang-hong JING and Xing-bang HUA.Participating draftsmen:Wan-zhu BAI,Bin XU,Dong-sheng XU,Yi GUO,Tie-ming MA,Xin-jun WANG,and Sheng-feng LU.
基金funded by National Natural Science Foundation of China(No.12172092,82174488,and 82305416)Shanghai Key Laboratory of Acupuncture Mechanism and Acupoint Function(No.21DZ2271800)+1 种基金Shanghai Municipal Science and Technology Commission(No.23YF1418300)Scientific Research Project on Traditional Chinese Medicine of Shanghai Municipal Health Commission—Youth Guidance Category(No.2022QN018).
文摘Objective The analgesic effect of acupuncture has been widely accepted.Nevertheless,the mechanism behind its analgesic effect remains elusive,thus impeding the progress of research geared toward enhancing the analgesic effect of acupuncture.This paper investigated the role of acupuncture needle surface textures on acupuncture’s analgesic effect by creating four experimental acupuncture needles with different patterns of surface augmentation.Methods Four types of acupuncture needles with different surface textures(the lined needle,circle needle,sandpaper needle,and threaded needle)were designed.Additionally,the force/torque measurement system used a robot arm and mechanical sensor to measure the force on the needle during insertion and manipulation.To perform acupuncture analgesia experiments,four experimental acupuncture needles and a normal needle were inserted into the Zusanli(ST36)acupoint of rats with inflammatory pain.By comparing the force and torque and the analgesic efficacy of the different acupuncture needles,these experiments tested the role of acupuncture needle body texture on acupuncture analgesia.Results The analgesic effects of different acupuncture needle body textures varied.Specifically,the force required to penetrate the skin with the lined needle was not greater than that for the normal needle;however,the needle with inscribed circles and the sandpaper-roughened needle both required greater force for insertion.Additionally,the torque of the lined needle reached 2×10^(-4)N·m under twisting manipulation,which was four times greater the torque of a normal needle(5×10^(-5)N·m).Furthermore,the lined needle improved pain threshold and mast cell degranulation rate compared to the normal needle.Conclusion Optimizing the texture of acupuncture needles can enhance acupuncture analgesia.The texture of our experimental acupuncture needles had a significant impact on the force needed to penetrate the skin and the torque needed to manipulate the needle;it was also linked to variable analgesic effects.This study provides a theoretical basis for enhancing the analgesic efficacy of acupuncture through the modification of needles and promoting the development of acupuncture therapy.
文摘This paper introduces part of the content in the association standard,T/CAAM0002–2020 Nomenclature and Location of Acupuncture Points for Laboratory Animals Part 2:Rat.This standard was released by the China Association of Acupuncture and Moxibustion on May 15,2020,implemented on October 31,2020,and published by Standards Press of China.The standard was drafted by the Institute of Acupuncture and Moxibustion,China Academy of Chinese Medical Sciences,and the Nanjing University of Chinese Medicine.Principal draftsmen:Xiang-hong JING and Xing-bang HUA.Participating draftsmen:Wan-Zhu BAI,Bin XU,Dong-sheng XU,Yi GUO,Tie-ming MA,Xin-jun WANG,and Sheng-feng LU.
基金National Key Research and Development Project:Clinical Evaluation of the Interventional Techniques for Abdominal Obesity(No.2019YFC1710102)。
文摘OBJECTIVE:To assess the efficacy and safety of the Qingyanyin formulated granules(轻燕饮配方颗粒,QYY),press needles(PN),and their combined application in addressing abdominal obesity(AO).This trial aims to offer a more scientifically grounded therapeutic regimen for clinical interventions.METHODS:From March 2021 to July 2021,a multicenter,triple-blind,randomized 2×2 factorial design clinical trial was conducted across 7 centers in 4 major cities within China's mainland.The trial participants were patients diagnosed with AO.The trial followed a 1∶1∶1∶1 random allocation ratio,assigning participants to one of four groups:QYY placebo plus simulated press needles(SPN)(placebo+SPN),QYY plus SPN(QYY+SPN),QYY placebo plus PN(placebo+PN),and QYY plus PN(QYY+PN).The trial participants received treatment for 12 weeks.Observe the changes in waist circumference,body weight,body mass index(BMI),Beck Depression Inventory(BDI),Beck Anxiety Inventory(BAI)scores,and Pittsburgh Sleep Quality Index(PSQI)before and after treatment.RESULTS:The QYY+PN group exhibited significant improvements in waist circumference compared to placebo+PN[Difference=-1.59,95%CI(-3.03,-0.16)]and placebo+SPN groups[Difference=-2.01,95%CI(-3.46,-0.57)].QYY+PN demonstrated a significant advantage over placebo+SPN[Difference=-2.01,95%CI(-3.46,-0.57)],and no statistically significant interaction was observed between the two interventions(P>0.05).In terms of weight and BMI improvements,the QYY+PN,QYY+SPN,and the PN+placebo groups all experienced trending greater reductions in weight compared to the placebo group.In terms of the total scores of PSQI,BAI,and BDI,all four groups exhibited improvements compared to the baseline.Specifically,concerning the change in total PSQI scores,the QYY+PN group exhibited a greater reduction;Regarding the change in total BAI scores,the PN+placebo group demonstrated a greater decrease;As for the change in total BDI scores,the QYY+SPN group displayed a greater reduction.CONCLUSION:This study confirmed that QYY+PN can effectively reduce the waist circumference of patients with AO.Furthermore,the combined approach offers greater benefits than either treatment alone,all without any reported serious adverse events.
基金co-supported by the National Key Research and Development Program of China(No.2024YFE0107900)the National Natural Science Foundation of China(No.62222105)+1 种基金the Natural Science Foundation of Guangdong Province,China(No.2024A1515010235)the 2024 China Unicom Guangdong low-altitude communication and sensing key technology research and digital twin platform research and development project(No.20241890).
文摘Unmanned aerial vehicle(UAV)swarm network consisting of a collection of micro UAVs can be used for many applications.It is well established that packet routing is a fundamental problem to achieve UAV collaboration.However,the highly dynamic nature of UAVs,frequently changing network topologies and security issues,poses significant challenges to packet forwarding in UAV networks.The existing topology-based routing protocols are not well suited in UAV network due to their high controlling overhead or excessive end-to-end delay.Geographic routing is regarded as a promising solution,as it only requires local information.In order to enhance the accuracy and security of geographic routing in highly dynamic UAV network,in this paper,we propose a new predictive geographic(PGeo)routing strategy with location verification.First,a detection mechanism is adopted to recognize malicious UAVs falsifying their location.Then,an accurate average service time of a packet in the medium access control(MAC)layer is derived to assist location prediction.The proposed delay model can provide a theoretical basis for future work,and our simulation results reveal that PGeo outstrips the existing geographic routing protocols in terms of packet delivery ratio in the presence of location spoofing behavior.
文摘BACKGROUND This is a randomized study to compare the diagnostic accuracy of endoscopic ultrasound(EUS)-guided sampling of pancreatic solid lesions obtained with the 22-gauge Franseen(EUS-fine needle biopsy)vs the 22-gauge standard needle(EUS-fine needle aspiration)without rapid onsite evaluation(ROSE),since,in most endoscopy units around the world ROSE is not routinely available.AIM To investigate the accuracy of EUS-guided sampling of pancreatic solid lesions obtained between two different needles without ROSE.METHODS Patients with a solid pancreatic were included.Patients were biopsied in a randomized order.The primary endpoint was the diagnostic sensitivity for pancreatic malignancy(PM).Secondary outcomes were adequacy of the sample,the mean tissue area,the mean tumor area,and the adverse event rate.RESULTS The final diagnosis was pancreatic adenocarcinoma in 38(76%),neuroendocrine tumor in 4(8%),chronic pancreatitis in 3(6%)patients.The sensitivity for PM with Franseen needle was 0.91[95%confidence interval(CI):0.80-0.98],vs 0.8(95%CI:0.67-0.91)(P=0.025)with standard needle.The specificity for PM did not differentiate.The accuracy of the standard needle for PM was 0.80(95%CI:0.66-0.90),and the Franseen group was 0.90(95%CI:0.78-0.97)(P=0.074).The technical success rates for the standard and Franseen needle groups were 94%(95%CI:0.83-0.99)and 100%(95%CI:0.92-1.00),respectively.The mean total tissue area in mm2(SD)was greater in the Franseen group,2.07(0.22)vs 1.16(0.17)(P<0.01).The mean tumor area in mm2(SD)was not different in Franseen group vs standard group,0.42(0.09)vs 0.47(0.09)(P=0.80).There were no adverse events.CONCLUSION The sensitivity for PM and mean total tissue area,was greater in the as compared with standard needle.The mean tumor area did not differ between the groups.
文摘A novel method is developed by utilizing the fractional frequency based multirange rulers to precisely position the passive inter-modulation(PIM)sources within radio frequency(RF)cables.The proposed method employs a set of fractional frequencies to create multiple measuring rulers with different metric ranges to determine the values of the tens,ones,tenths,and hundredths digits of the distance.Among these rulers,the one with the lowest frequency determines the maximum metric range,while the one with the highest frequency decides the highest achievable accuracy of the position system.For all rulers,the metric accuracy is uniquely determined by the phase accuracy of the detected PIM signals.With the all-phase Fourier transform method,the phases of the PIM signals at all fractional frequencies maintain almost the same accuracy,approximately 1°(about 1/360 wavelength in the positioning accuracy)at the signal-to-noise ratio(SNR)of 10 d B.Numerical simulations verify the effectiveness of the proposed method,improving the positioning accuracy of the cable PIM up to a millimeter level with the highest fractional frequency operating at 200 MHz.
基金financially supported by Wuxi Yanping Electronic Technology Co.Ltd.
文摘Semiconductor electronic devices are prone to charge accumulation during production and transportation,which usually causes device breakdown.Ionizers are widely used for electrostatic elimination,and utilizing semiconductor silicon for the discharge needle material in ionizers can effectively prevent metal contamination.To investigate the discharge characteristics of silicon needles and their mode modulation mechanism,this study has established an experimental platform for silicon needle-plate discharge under positive polarity voltage.Discharge pulse parameters and optical signals were measured at varying electrode spacings.The experimental results reveal that silicon needle discharge progresses through four regimes:the spontaneous streamer,the periodic streamer,the cluster streamer,and the glow discharge.Among these,the pulse amplitude is most uniform and stable in the periodic streamer regime.In addition,shorter-gap discharge exhibits higher pulse amplitude and repetition frequency but is easier to transition into the filament regime.The formation process of a single pulse is closely related to the field strength in the ionization region near the needle tip.Hence,parameters such as the pulse rising edge time and falling edge time show minimal variation with voltage.The amount of charge generated per unit time is primarily influenced by the repetition frequency.Consequently,the electrostatic ionizer produces the highest,most stable,and most uniform charges if it operates in the periodic streamer regime.
基金supported by National Natural Science Foundation of China Grant(No.42004040,42474092,U2239204,and 42304145)Natural Science Foundation of Jiangxi Province Grant(20242BAB25190 and 20232BAB213077).
文摘Accurate and rapid determination of source locations is of great significance for surface microseismic monitoring.Traditional methods,such as diffraction stacking,are time-consuming and challenging for real-time monitoring.In this study,we propose an approach to locate microseismic events using a deep learning algorithm with surface data.A fully convolutional network is designed to predict source locations.The input data is the waveform of a microseismic event,and the output consists of three 1D Gaussian distributions representing the probability distribution of the source location in the x,y,and z dimensions.The theoretical dataset is generated to train the model,and several data augmentation methods are applied to reduce discrepancies between the theoretical and field data.After applying the trained model to field data,the results demonstrate that our method is fast and achieves comparable location accuracy to the traditional diffraction stacking location method,making it promising for real-time microseismic monitoring.
文摘Despite advances in surgery,chemotherapy,and radiotherapy,the treatment of colorectal cancer(CRC)requires more personalized approaches based on tumor biology and molecular profiling.While some relevant mutations have been associated with differential response to immunotherapy,such as RAS and BRAF mutations limiting response to anti-epithelial growth factor receptor drugs or microsatellite instability predisposing susceptibility to immune checkpoint inhibitors,the role of inflammation in dictating tumor progression and treatment response is still under investigation.Several inflammatory biomarkers have been identified to guide patient prognosis.These include the neutrophil-lymphocyte ratio,Glasgow prognostic score(GPS)and its modified version,lymphocyte-Creactive protein ratio,and platelet-lymphocyte ratio.However,these markers are not yet included in the standard clinical management of patients with CRC,and further research is needed to evaluate their efficacy in different patient populations.A recent study by Wang et al,published in the World Journal of Gastroenterology,sheds light on the prognostic significance of pan-immune-inflammation value(PIV)in CRC,particularly concerning primary tumor location.Specifically,the authors found that a high PIV was strongly correlated with worse disease-free survival in patients with left-sided colon cancer,whereas no such association was observed in patients with right-sided colon cancer.Integrating tumor location into the prognostic assessment of CRC may improve our ability to more accurately identify high-risk patients and develop personalized treatment plans that are more likely to improve patient outcomes.
基金Major Program of National Social Science Foundation of China,No.21&ZD107。
文摘Data centers operate as physical digital infrastructure for generating,storing,computing,transmitting,and utilizing massive data and information,constituting the backbone of the flourishing digital economy across the world.Given the lack of a consistent analysis for studying the locational factors of data centers and empirical deficiencies in longitudinal investigations on spatial dynamics of heterogeneous data centers,this paper develops a comprehensive analytical framework to examine the dynamic geographies and locational factors of techno-environmentally heterogeneous data centers across Chinese cities in the period of 2006–2021.First,we develop a“supply-demand-environment trinity”analytical framework as well as an accompanying evaluation indicator system with Chinese characteristics.Second,the dynamic geographies of data centers in Chinese cities over the last decades are characterized as spatial polarization in economically leading urban agglomerations alongside persistent interregional gaps across eastern,central,and western regions.Data centers present dual spatial expansion trajectories featuring outward radiation from eastern core urban agglomerations to adjacent peripheries and leapfrog diffusion to strategic central and western digital infrastructural hubs.Third,it is empirically verified that data center construction in Chinese cities over the last decades has been jointly influenced by supply-,demand-,and environment-side locational factors,echoing the efficacy of the trinity analytical framework.Overall,our findings demonstrate the temporal variance,contextual contingency,and attribute-based differentiation of locational factors underlying techno-environmentally heterogeneous data centers in Chinese cities.
基金Project(SICGM2023301) supported by the State Key Laboratory of Strata Intelligent Control and Green Mining Co-founded by Shandong Province and the Ministry of Science and Technology,ChinaProject(SMDPC202202) supported by the Key Laboratory of Mining Disaster Prevention and Control,ChinaProject(U21A2030) supported by the National Natural Science Foundation of China。
文摘Microseismic (MS) source location plays an important role in MS monitoring. This paper proposes a MS source location method based on particle swarm optimization (PSO) and multi-sensor arrays, where a free weight joints the P-wave first arrival data. This method adaptively adjusts the preference for “superior” arrays and leverages “inferior” arrays to escape local optima, thereby improving the location accuracy. The effectiveness and stability of this method were validated through synthetic tests, pencil-lead break (PLB) experiments, and mining engineering applications. Specifically, for synthetic tests with 1 μs Gaussian noise and 100 μs large noise in rock samples, the location error of the multi-sensor arrays jointed location method is only 0.30 cm, which improves location accuracy by 97.51% compared to that using a single sensor array. The average location error of PLB events on three surfaces of a rock sample is reduced by 48.95%, 26.40%, and 55.84%, respectively. For mine blast event tests, the average location error of the dual sensor arrays jointed method is 62.74 m, 54.32% and 14.29% lower than that using only sensor arrays 1 and 2, respectively. In summary, the proposed multi-sensor arrays jointed location method demonstrates good noise resistance, stability, and accuracy, providing a compelling new solution for MS location in relevant mining scenarios.
基金the support of the China Three Gorges Corporation Science and Technology Fund, with the numbers 0799275the support of the National Natural Science Foundation of China, with the numbers 42174177 and 62106239。
文摘The study area is rich in shale gas resources and has reached the stage of comprehensive development. Shale gas extraction poses risks such as induced seismicity and well closure, compounded by the limited availability of fi xed seismic monitoring stations nearby. To address these challenges, a dense observation array was developed within the study area to monitor and analyze microseismic activity during hydraulic fracturing. Microseismic events generated by hydraulic fracturing typically exhibit low amplitude and signal-to-noise ratio, rendering traditional manual analysis methods impractical. To overcome these limitations, an innovative artifi cial intelligence method combining picking-association-location (PAL) and match-expand- shift-stack (MESS) techniques (PALM) has been utilized for automated seismic detection. Numerous factors influence the accuracy of microseismic detection and localization. To evaluate these factors, the effects of various velocity structure models, instrument types, and station distributions on seismic location were analyzed and compared. The results indicate that the PALM method significantly mitigates the influence of velocity structure models on seismic location accuracy. Additionally, the use of broadband seismic instruments and a uniform station distribution enhances the precision of seismic location results. Furthermore, by integrating data from diff erent types of observation instruments, a comprehensive seismic catalog for the study area was established. These fi ndings not only enhance seismic location accuracy but also provide valuable guidance for optimizing regional seismic monitoring network design and improving seismic risk assessment.
基金support provided by the Interna-tional Institute of Earthquake Engineering and Seismology(IIEES)un-der project number 5424-816.
文摘We present a machine learning approach for earthquake location and magnitude estimation based on seismic arrival time patterns,using Histogram-Based Gradient Boosting for its high accuracy and computational efficiency.The model is first evaluated using a synthetic earthquake bulletin that simulates realistic network geometry,station-event distributions,and incorporates a 3D velocity model for accurate travel-time compu-tation.Input features include P and S arrival times and amplitudes,while targets consist of location,origin time,magnitude,and uncertainty measures(horizontal and depth errors,azimuthal gap).Model performance is evaluated using𝑅2,Mean Absolute Error(MAE),and Median Absolute Error(MEDAE),demonstrating high accuracy across datasets with varying levels of completeness.Finally,we validate the model using real-world data from the Ahar-Varzaghan 2012 aftershock sequence in NW Iran.The model accurately recovers key spatial patterns of seismicity despite significant missing data,and the results align with previous high-resolution studies.These findings confirm that the proposed method generalizes well beyond synthetic settings and offers a fast,robust alternative for operational seismic networks and rapid hazard assessment.
基金supported by the National Key Research and Development Program of China(2023YFC3008605)the Innovation Group Project of Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(311021002)the Seismological Research Foundation for Youths of Guangdong Earthquake Agency(Open Funding Project of Key Laboratory of Earthquake Monitoring and Disaster Mitigation Technology,China Earthquake Administration)(GDDZY202309)。
文摘The travel-time corrections for the primary seismic phases of 72 stations in the Guangdong seismic network,relative to the 1D South China travel-time model,were determined using joint hypocentral determination(JHD)and statistical analysis methods.The travel-time corrections for the Pg phase of 72 stations range between-0.25 s and 0.14 s,while the corrections for the Sg phase range between 0.27 s and 0.35 s,and those for the Pn phase are between-0.86 s and 0.07 s.The spatial distribution of travel-time corrections for Pg,Sg,and Pn phases of 72 stations correlates well with the geological structure in this region.This indicates that the travel-time corrections for Pg and Sg phases are mainly caused by the discrepancy between the actual crustal velocity structure beneath the stations and the 1D South China travel-time model.These corrections empirically compensate for systematic travel-time errors arising from such discrepancies.The primary factor contributing to the travel-time corrections for the Pn phase is the Moho undulations or tilt.These corrections are intended to compensate for systematic errors in travel time caused by variations in the actual Moho.By integrating the obtained travel-time corrections into the HYPO-SAT location algorithm,test results showed an obvious improvement in location accuracy and origin time precision for explosion events.The variation of horizontal distance between repeating earthquake pairs has also improved,with 86%of the repeating earthquake pair spacing being more accurately estimated after correction.This suggests the crucial significance of travel-time correction in earthquake location,and the consideration of travel-time correction exerts a notable impact on enhancing earthquake location accuracy.
基金supported by National Natural Science Foundation of China(Nos.42374076,42174128 and 42004115)Natural Science Foundation for Excellent Young Scholars of Hunan Province,China(No.2022JJ 20057)+1 种基金Central South University Innovation-Driven Research Programme(No.2023CXQD063)the Guangdong Provincial Key Laboratory of Geophysical High-resolution Imaging Technology(No.2022B1212010002).
文摘Seismic source locations can characterize the spatial and temporal distributions of seismic sources,and can provide important basic data for earthquake disaster monitoring,fault activity characterization,and fracture growth interpretation.Waveform stacking-based location methods invert the source locations by focusing the source energy with multichannel waveforms,and these methods exhibit a high level of automation and noise-resistance.Taking the cross-correlation stacking(CCS)method as an example,this work attempts to study the influential factors of waveform stacking-based methods,and introduces a comprehensive performance evaluation scheme based on multiple parameters and indicators.The waveform data are from field monitoring of induced microseismicity in the Changning region(southern Sichuan Basin of China).Synthetic and field data tests reveal the impacts of three categories of factors on waveform stacking-based location:velocity model,monitoring array,and waveform complexity.The location performance is evaluated and further improved in terms of the source imaging resolution and location error.Denser array monitoring contributes to better constraining source depth and location reliability,but the combined impact of multiple factors,such as velocity model uncertainty and multiple seismic phases,increases the complexity of locating field microseismic events.Finally,the aspects of location uncertainty,phase detection,and artificial intelligencebased location are discussed.
文摘Objective: To explore the effectiveness of applying an infusion project team in the safety risk management of indwelling needle use. Methods: A total of 200 patients who used intravenous indwelling needles during hospital treatment from July to October 2022 were selected and randomly divided into an observation group and a control group, with 100 patients in each group. Patients in the control group received routine nursing methods, while those in the observation group were managed using the safety risk management method of the infusion project team. The tube blocking rate and tube removal rate were compared between the two groups. Results: The one-time puncture success rate and the standard implementation rate of intravenous indwelling needle use in the observation group were significantly higher than those in the control group. The total incidence of complications in the observation group was significantly lower than that in the control group, and patient satisfaction in the observation group was notably higher, with statistically significant differences (P < 0.05). Conclusion: The application of an infusion project team in the safety risk management of indwelling needle use is effective and has positive impacts on improving the one-time puncture success rate, the standard implementation rate of intravenous indwelling needle use, and patient satisfaction. It is a practice worth promoting in clinical settings.
基金supported by the National Natural Science Foundation of China(No.52274026)the National Key Research and Development Program(No.2022YFC2806504)the CNOOC Research Project(No.KJGG-2022-17-04 and NO.KJGG-2022-17-05).
文摘Effective isolation between the cement sheath and the sandstone is crucial for the development and production of oil and gas wells in sandstone formations.In this study,a cement-sandstone composite(CSC)was prepared,and based onμ-CT three-dimensional reconstruction imaging and finite element analysis(FEA)techniques,the stress distribution and potential failure mechanism at the cement-sandstone bonding interface under axial loading were analyzed.The key findings are as follows:(1)stress concentrations are highly likely to form at the gap between the cement and sandstone interface and around interfacial voids,with Von Mises stress reaching critical levels of 18.0-20.0 MPa at these locations,significantly exceeding the stress magnitudes in well-bonded regions;(2)the phenomenon of local stress concentration driven by interfacial defects can be identified as the main basis for predicting damage location in interfacial debonding and continuous shear under axial load;(3)ensuring tight cementation at the cement-sandstone interface and minimizing interfacial voids are paramount for preventing stress-induced failure;(4)the critical Von Mises stress value of 20 MPa at the interface defect can be used as a benchmark for material selection and designed to ensure long-term integrity in oil and gas well applications subjected to similar axial loads.These findings contribute to a more accurate understanding of the failure mechanism of the cement-sandstone interface and to the precise design of material properties,thereby ensuring the long-term integrity of oil and gas well applications subjected to similar axial loads.
基金Open Project of Shanghai Key Laboratory of Lightweight Composite,China(No.2232021A4-04)。
文摘Double-shaft-driven needle punching machine is a specialized equipment designed for processing C/C crucible preforms.Its main needle punching module is operated by two sets of reciprocating crank-slider mechanisms.The intense vibration during needle punching not only generates huge noise,but also substantially reduces the quality of the preform.It is imperative to perform a dynamic analysis and optimization of the entire needle punching machine.In this paper,the three-dimensional(3D)model of the entire double-shaft-driven needle punching machine for C/C crucible preforms is established.Based on the modal analysis theory,the modal characteristics of the needle punching machine under various operating conditions are analyzed and its natural frequencies and vibration modes are determined.The harmonic response analysis is then employed to obtain the amplitude of the needle plate at different frequencies,and the structural weak points of the needle punching machine are identified and improved.The feasibility of the optimized scheme is subsequently reevaluated and verified.The results indicate that the first six natural frequencies of the machine increase,and the maximum amplitude of the needle plate decreases by 70.3%.The enhanced dynamic characteristics of the machine significantly improve its performance,enabling more efficient needle punching of C/C crucible preforms.
文摘Objective:To investigate the efficacy and safety of combined spinal-epidural(CSE)anesthesia using a 25G spinal fine needle via a single puncture for lower limb surgery in children.Methods:Sixty pediatric patients scheduled for surgery were randomly divided into two groups,with 30 patients in each.The control group received subarachnoid anesthesia with 2–2.5 mL of 0.33%ropivacaine.The experimental group received the same ropivacaine dose,followed by withdrawal of the needle to the epidural space and administration of 0.1 mg hydromorphone diluted to 5 mL.The anesthetic and analgesic effects,incidence of complications,and postoperative family satisfaction were observed in both groups.Results:Compared with the control group,the experimental group showed a higher anesthesia success rate,a shorter onset time,and a longer maintenance time of anesthesia(p<0.05).Postoperative analgesia at various time points was significantly better in the experimental group(p<0.05).The total incidence of complications was lower in the experimental group,though the difference was not statistically significant(p>0.05).Family satisfaction was significantly higher in the experimental group(p<0.05).Conclusion:CSE anesthesia using a 25G fine needle via a single puncture for pediatric lower limb surgery is safe and effective.It can significantly improve surgical outcomes and is worthy of clinical promotion.
