Background:This study aims to investigate the application and effect of a new daytime surgery and same-day discharge mode in cataract clinic.Methods:Two hundred patients with cataract intended to undertake daytime sur...Background:This study aims to investigate the application and effect of a new daytime surgery and same-day discharge mode in cataract clinic.Methods:Two hundred patients with cataract intended to undertake daytime surgery from August 2019 to January 2020 in the Cataract department were enrolled for the study.Among them,100 patients from January 2020 with the new daytime surgery and same-day discharge were the experimental group.While the other 100 patients without the designated set-up from August 2019 worked as a control group.The length and cost of hospitalization,the length of waiting for the elevator,the patient satisfaction,and the awareness rate of health education were evaluated.Results:After application of the new daytime surgery and same-day discharge set-up,the patients’satisfaction rate increased from 91%to 95%,and the rate of awareness of health education increased from 87%to 90%,the difference was statistically significant(χ^(2)=0.61,P=0.04 andχ^(2)=0.22,P=0.01).The length of hospitalization,hospitalization costs and waiting time for elevators were much reduced than those without this set-up.Conclusions:The application of the cataract daytime surgery and same-day discharge set-up can effectively alleviate the overcrowding of the ward environment,reduce the workload of medical staff,and improve patient satisfaction.Therefore,the daytime surgery and same-day discharge set-up has wide clinical applications.展开更多
BACKGROUND Endoscopic submucosal dissection(ESD)is an established technique for the treatment of early gastrointestinal neoplasia.Generally,multi-day(M-D)admission is required for patients undergoing ESD due to potent...BACKGROUND Endoscopic submucosal dissection(ESD)is an established technique for the treatment of early gastrointestinal neoplasia.Generally,multi-day(M-D)admission is required for patients undergoing ESD due to potential complications.AIM To evaluate the feasibility of a same-day(S-D)discharge strategy for ESD of the esophagus or stomach.METHODS The data of patients who underwent esophageal or gastric ESD were retrospectively collected from January 2018 to December 2021 at Peking University Cancer Hospital.The propensity score matching(PSM)method was applied to balance the unevenly distributed patient baseline characteristics between the S-D and M-D groups.Intraoperative and postoperative parameters were compared between the matched groups.RESULTS Among the 479 patients reviewed,470 patients,including 91 in the S-D group and 379 in the M-D group,fulfilled the inclusion and exclusion criteria.Following PSM,78 patients in each group were paired using the 1:1 nearest available score match algorithm.No significant difference was found between groups with respect to intraoperative and postprocedural major adverse events(AEs).Tumor size,complete resection rate,and procedural duration were comparable between the groups.The S-D group demonstrated a significantly shorter length of hospital stay(P<0.001)and lower overall medical expenses(P<0.001)compared with the M-D group.CONCLUSION The S-D discharge strategy may be feasible and effective for esophagogastric ESD,and the procedural-related AEs can be managed successfully.展开更多
The adoption of transradial access in the United States and internationally has been growing over the past few years.In the population of patients presenting with acute coronary syndromes,particularly ST-elevation myo...The adoption of transradial access in the United States and internationally has been growing over the past few years.In the population of patients presenting with acute coronary syndromes,particularly ST-elevation myocardial infarction,transradial access has the benefit of fewer vascular and bleeding complications and lower mortality rates over transfemoral access.We will examine the current evidence supporting transradial access for several patient populations,including those patients presenting with acute coronary syndromes.We will review the literature regarding the learning curve for transradial access with new operators,as well as experienced transfemoral operators new to transradial access.Finally,we will investigate the role of transradial access in same-day discharge for stable patients undergoing percutaneous coronary intervention.展开更多
Sustainable nitrogen fixation driven by renewable energy sources under mild conditions has been widely sought to replace the industrial Haber-Bosch process.The fixation of nitrogen in the form of NO_(x)^(-)and NH_4^(+...Sustainable nitrogen fixation driven by renewable energy sources under mild conditions has been widely sought to replace the industrial Haber-Bosch process.The fixation of nitrogen in the form of NO_(x)^(-)and NH_4^(+)into aqueous solutions using electricity-driven gas-liquid discharge plasma is considered a promising prescription.In this paper,a scalable bubble discharge excited by nanosecond pulse power is employed for nitrogen fixation in the liquid phase.The nitrogen fixation performance and the mechanisms are analyzed by varying the power supply parameters,working gas flow rate and composition.The results show that an increase in voltage and frequency can result in an enhanced NO_(3)^(-)yield.Increases in the gas flow rate can result in inadequate activation of the working gas,which together with more inefficient mass transfer efficiencies can reduce the yield.The addition of O_(2) effectively elevates NO_(3)^(-)production while simultaneously inhibiting NH_4^(+) production.The addition of H_(2)O vapor increases the production of OH and H,thereby promoting the generation of reactive nitrogen and enhancing the yield of nitrogen fixation.However,the excessive addition of O_(2) and H_(2)O vapor results in negative effect on the yield of nitrogen fixation,due to the significant weakening of the discharge intensity.The optimal nitrogen fixation yield was up to 16.5 μmol/min,while the optimal energy consumption was approximately 21.3 MJ/mol in this study.Finally,the mechanism related to nitrogen fixation is discussed through the optical emission spectral(OES) information in conjunction with the simulation of energy loss paths in the plasma by BOLSIG+.The work advances knowledge of the effect of parameter variations on nitrogen fixation by gas-liquid discharge for higher yield and energy production.展开更多
Ultrasonic-assisted micro-electro-discharge machining(EDM)has the potential to enhance processing responses such as material removal rate(MRR)and surface finish.To understand the reasons for this enhancement,the physi...Ultrasonic-assisted micro-electro-discharge machining(EDM)has the potential to enhance processing responses such as material removal rate(MRR)and surface finish.To understand the reasons for this enhancement,the physical mechanisms responsible for the individual discharges and the craters that they form need to be explored.This work examines features of craters formed by single discharges at various parameter values in both conventional and ultrasonic-assistedEDM of Ti6Al4V.High-speed imaging of the plasma channel is performed,and data on the individual discharges are captured in real-time.A 2D axisymmetric model using finite element software is established to model crater formation.On the basis of simulation and experimental results,a comparative study is then carried out to examine the effects of ultrasonic vibrational assistance on crater geometry.For every set ofEDM parameters,the crater diameter and depth from a single discharge are found to be higher in ultrasonic-assistedEDM than in conventionalEDM.The improved crater geometry and the reduced bulge formation at the crater edges are attributed to the increased melt pool velocity and temperature predicted by the model.展开更多
Dielectric barrier discharge(DBD)is considered as a promising technique to produce large volume uniform plasma at atmospheric pressure,and the dielectric barrier layer between the electrodes plays a key role in the DB...Dielectric barrier discharge(DBD)is considered as a promising technique to produce large volume uniform plasma at atmospheric pressure,and the dielectric barrier layer between the electrodes plays a key role in the DBD processes and enhancing discharge uniformity.In this work,the uniformity and discharge characteristics of the nanosecond(ns)pulsed DBD with dielectric barrier layers made of alumina,quartz glass,polycarbonate(PC),and polypropylene(PP)are investigated via discharge image observation,voltage-current waveform measurement and optical emission spectral diagnosis.Through analyzing discharge image by gray value standard deviation method,the discharge uniformity is quantitatively calculated.The effects of the space electric field intensity,the electron density(Ne),and the space reactive species on the uniformity are studied with quantifying the gap voltage Ug and the discharge current Ig,analyzing the recorded optical emission spectra,and simulating the temporal distribution of Ne with a one-dimensional fluid model.It is found that as the relative permittivity of the dielectric materials increases,the space electric field intensity is enhanced,which results in a higher Ne and electron temperature(Te).Therefore,an appropriate value of space electric field intensity can promote electron avalanches,resulting in uniform and stable plasma by the merging of electron avalanches.However,an excessive value of space electric field intensity leads to the aggregation of space charges and the distortion of the space electric field,which reduce the discharge uniformity.The surface roughness and the surface charge decay are measured to explain the influences of the surface properties and the second electron emission on the discharge uniformity.The results in this work give a comprehensive understanding of the effect of the dielectric materials on the DBD uniformity,and contribute to the selection of dielectric materials for DBD reactor and the realization of atmospheric pressure uniform,stable,and reactive plasma sources.展开更多
The discharge morphology of pulsed dielectric barrier discharge(PDBD) plays important roles in its applications. Here, we systematically investigated the effects of the voltage amplitude,discharge gap, and O_(2)conten...The discharge morphology of pulsed dielectric barrier discharge(PDBD) plays important roles in its applications. Here, we systematically investigated the effects of the voltage amplitude,discharge gap, and O_(2)content on the PDBD morphology, and revealed the possible underlying mechanism of the U-shaped formation. First, the morphological evolution under different conditions was recorded. A unique U-shaped region appears in the middle edge region when the gap is larger than 2 mm, while the entire discharge region remains columnar under a 2 mm gap in He PDBD. The width of the discharge and the U-shaped region increase with the increase in voltage, and decrease with the increase of the gap and O_(2)content. To explain this phenomenon,a two-dimensional symmetric model was developed to simulate the spatiotemporal evolution of different species and calculate the electric thrust. The discharge morphology evolution directly corresponds to the excited-state atomic reduction process. The electric thrust on the charged particles mainly determines the reaction region and strongly influences the U-shaped formation.When the gap is less than 2 mm, the electric thrust is homogeneous throughout the entire region,resulting in a columnar shape. However, when the gap is larger than 2 mm or O_(2)is added, the electric thrust in the edge region becomes greater than that in the middle, leading to the U-shaped formation. Furthermore, in He PDBD, the charged particles generating electric thrust are mainly electrons and helium ions, while in He/O_(2)PDBD those that generate electric thrust at the outer edge of the electrode surface are mainly various oxygen-containing ions.展开更多
Background: An abnormal vaginal discharge is a common complaint among women of reproductive age, and it can indicate serious conditions like pelvic inflammatory disease and cervical cancer. This study aimed to assess ...Background: An abnormal vaginal discharge is a common complaint among women of reproductive age, and it can indicate serious conditions like pelvic inflammatory disease and cervical cancer. This study aimed to assess the predictors of abnormal vaginal discharge in women of reproductive age group in Imo State, Southeast Nigeria. Methods: A cross-sectional study was conducted among 368 women of reproductive age group attending the clinic at Federal University Teaching Hospital Owerri, in Imo State, Nigeria. Respondents were recruited using a systematic sampling technique. Data were collected using a pre-tested interviewer-administered questionnaire. Multivariable analysis was performed to determine predictors of abnormal vaginal discharge. Statistical significance was set at p Results: The mean age of the respondents was 30 ± 4.5 years. Predictors of abnormal vaginal discharge were: age 36 - 45 years (OR: 4.5;95% C.I: 1.023 - 8.967, p = 0.041), being a student (OR: 2.4: 95% C.I: 1.496 - 7.336, p = 0.003), use of oral contraceptives (OR: 3.4;95% C.I: 1.068 - 6.932, p = 0.010), use of water cistern (OR: 4.7;C.I: 1.654 - 5.210, p = 0.028) anal hygiene practices (OR: 2.7;95% C.I: 1.142 - 4.809, p Conclusion: These findings suggest that targeted sexual and reproductive health interventions should be provided to reduce the risk of abnormal vaginal discharge in women of reproductive age group.展开更多
In this work,a gas-solid two-phase gliding arc discharge(GS-GAD)reactor was built.Gliding arc was formed in the gap between the blade electrodes,and solid powder was deposited on the sieve plate positioned beneath the...In this work,a gas-solid two-phase gliding arc discharge(GS-GAD)reactor was built.Gliding arc was formed in the gap between the blade electrodes,and solid powder was deposited on the sieve plate positioned beneath the blade electrodes.A range of experimental parameters,including the inter-electrode spacing,gas flow rate,applied voltage,and the type of the powder,were systematically varied to elucidate the influence of solid powder matter on the dynamics of gliding arc discharge(GAD).The discharge images were captured by ICCD and digital camera to investigate the mass transfer characteristics of GS-GAD,and the electrical parameters,such as the effective values of voltage,current,and discharge power were record to reveal the discharge characteristics of GS-GAD.The results demonstrate that powder undergoes spontaneous movement towards the upper region of the gliding arc due to the influence of electric field force.Increasing the discharge voltage,decreasing relative dielectric constant of the powder and reducing the electrode-to-sieve-plate distance all contribute to a greater involvement of powder in the GAD process,subsequently resulting in an enhanced powder concentration within the GAD region.Additionally,powder located beneath the gliding arc experiences downward resistance caused by the opposing gas flow and arc.Excessive gas flow rate notably hampers the powder concentration within the discharge region,and the velocity of powder motion in the upper part of the GAD region is reduced.Under the condition of electrode-to-sieve-plate distance of 30 mm,gas flow rate of 1.5 L/min,and peak-to-peak voltage of 31 kV,the best combination of arc gliding and powder spark discharge phenomena can be achieved with the addition of Al_(2)O_(3) powder.展开更多
It is difficult to determine the discharge stages in a fixed time of repetitive discharge underwater due to the arc formation process being susceptible to external environmental influences. This paper proposes a novel...It is difficult to determine the discharge stages in a fixed time of repetitive discharge underwater due to the arc formation process being susceptible to external environmental influences. This paper proposes a novel underwater discharge stage identification method based on the Strong Tracking Filter(STF) and impedance change characteristics. The time-varying equivalent circuit model of the discharge underwater is established based on the plasma theory analysis of the impedance change characteristics and mechanism of the discharge process. The STF is used to reduce the randomness of the impedance of repeated discharges underwater, and then the universal identification resistance data is obtained. Based on the resistance variation characteristics of the discriminating resistance of the pre-breakdown, main, and oscillatory discharge stages, the threshold values for determining the discharge stage are obtained. These include the threshold values for the resistance variation rate(K) and the moment(t).Experimental and error analysis results demonstrate the efficacy of this innovative method in discharge stage determination, with a maximum mean square deviation of Scrless than 1.761.展开更多
SF_(6) has excellent insulation performance and arc extinguishing ability,and is widely used in the power industry.However,its global warming potential is about 23,500 times that of C0_(2),it can exist stably in the a...SF_(6) has excellent insulation performance and arc extinguishing ability,and is widely used in the power industry.However,its global warming potential is about 23,500 times that of C0_(2),it can exist stably in the atmosphere,it is not easily degradable and is of great potential harm to the environment.Based on pulsed dielectric barrier discharge plasma technology,the effects of H_(2)O and 0_(2) on the degradation of SF_(6) were studied.Studies have shown that H_(2)O can effectively promote the decomposition of SF_(6) and improve its degradation rate and energy efficiency of degradation.Under the action of a pulse input voltage and input frequency of 15 kV and 15 kHz,respectively,when H_(2)O is added alone the effect of 1% H_(2)O is the best,and the rate and energy efficiency of degradation of SF_(6) reach their maximum values,which are 91.9% and 8.25 g kWh^(-1),respectively.The synergistic effect of H_(2)O and O_(2) on the degradation of SF_(6) was similar to that of H_(2)O.When the concentration of H_(2)O and O_(2) was 1%,the system obtained the best rate and energy efficiency of degradation,namely 89.7% and 8.05 g kWh~(-1),respectively.At the same time,different external gases exhibit different capabilities to regulate decomposition products.The addition of H_(2)O can effectively improve the selectivity of S0_(2).Under the synergistic effect of H_(2)O and O_(2),with increase in O_(2) concentration the degradation products gradually transformed into SO_(2)F_(2).From the perspective of harmless treatment of the degradation products of SF_(6),the addition of O_(2) during the SF_(6) degradation process should be avoided.展开更多
This work presents an analysis of the research conducted in many countries in recent years on the so-called Gatchina discharge.The findings indicate that the Gatchina discharge exhibits the majority of the characteris...This work presents an analysis of the research conducted in many countries in recent years on the so-called Gatchina discharge.The findings indicate that the Gatchina discharge exhibits the majority of the characteristics of natural ball lightning,making it the most effective method for reproducing and studying this phenomenon.To a large extent,our new results are based on experiments performed for the first time to visualize dust particles arising in an erosive emission,as well as the formation of vortex flows.These experiments make it possible to explain the ability of the Gatchina discharge to maintain its shape for a long time in the afterglow.展开更多
Ionic liquid electrospray(ILE) in an atmospheric environment is often accompanied by the gas discharge phenomenon. It interferes with the normal operation of the electrospray and the measurement of experimental parame...Ionic liquid electrospray(ILE) in an atmospheric environment is often accompanied by the gas discharge phenomenon. It interferes with the normal operation of the electrospray and the measurement of experimental parameters. In this study, electrospray experiments were conducted on the ionic liquid EMI-BF4. The observations revealed that the operating modes of the ionic liquid depend on the voltage polarity at high voltages. Additionally, a correspondence between the operating mode of ILE and the current signal in the circuit was established. The shape of the liquid cone formed at the needle tip bore a striking resemblance to the plume of corona discharge, suggesting that the motion trajectory of electrons influenced the curvature of the liquid cone. Steamer theory provided a clear explanation for the change in curvature as the voltage increased.展开更多
The influence of micro-Ca/In alloying on the microstructural charac teristics,electrochemical behaviors and discharge properties of extruded dilute Mg-0.5Bi-0.5Sn-based(wt.%)alloys as anodes for Mg-air batteries are e...The influence of micro-Ca/In alloying on the microstructural charac teristics,electrochemical behaviors and discharge properties of extruded dilute Mg-0.5Bi-0.5Sn-based(wt.%)alloys as anodes for Mg-air batteries are evaluated.The grain size and texture intensity of the Mg-Bi-Sn-based alloys are significantly decreased after the Ca/In alloying,particularly for the In-containing alloy.Note that,in addition to nanoscale Mg_(3)Bi_(2)phase,a new microscale Mg_(2)Bi_(2)Ca phase forms in the Ca-containing alloy.The electrochemical test results demonstrate that Ca/In micro-alloying can enhance the electrochemical activity.Using In to alloy the Mg-Bi-Sn-based alloy is effective in restricting the cathodic hydrogen evolution(CHE)kinetics,leading to a low self-corrosion rate,while severe CHE occurred after Ca alloying.The micro-alloying of Ca/In to Mg-Bi-Sn-based alloy strongly deteriorates the compactness of discharge products film and mitigates the"chunk effect"(CE),hence the cell voltage,anodic efficiency as well as discharge capacity are greatly improved.The In-containing alloy exhibits outstanding discharge performance under the combined effect of the modified microstructure and discharge products,thus making it a potential anode material for primary Mg-air battery.展开更多
For the basins with debris flow development,its channel terrain exhibits a tortuous shape,which significantly restricts the movement of debris flows and leads to severe erosion effects on the concave bank.Therefore,th...For the basins with debris flow development,its channel terrain exhibits a tortuous shape,which significantly restricts the movement of debris flows and leads to severe erosion effects on the concave bank.Therefore,this study aims to analyze the shear force of debris flows within the bend channel.We established the relationship between the shear force and bend curvature through laboratory experiments.Under the long-term erosion by debris flows,the curvature radius of bends gradually increases,however,when this increasing trend reaches an equilibrium state with the intensity of debris flow discharge,there will be no significant change in curvature radius.In general,the activity pattern and discharges of debris flows would remain relatively stable.Hence,we can infer the magnitude of debris flow discharges from the terrain parameters of the bend channel.展开更多
As the size of satellites scales down, low-power and compact propulsion systems such as the pulsed plasma thruster(PPT) are needed for stabilizing these miniature satellites in orbit. Most PPT systems are operated at ...As the size of satellites scales down, low-power and compact propulsion systems such as the pulsed plasma thruster(PPT) are needed for stabilizing these miniature satellites in orbit. Most PPT systems are operated at 2 J or more of discharge energy. In this work, the performance of a PPT with a side-fed, tongue-flared electrode configuration operated within a lower discharge energy range of 0.5-2.5 J has been investigated. Ablation and charring of the polytetrafluoroethylene propellant surface were analyzed through field-effect scanning electron microscopy imaging and energy-dispersive X-ray spectroscopy. When the discharge energy fell below 2 J, inconsistencies occurred in the specific impulse and the thrust efficiency due to the measurement of the low mass bit. At energy ≥2 J, the performance parameters are compared with other PPT systems of similar configuration and discussed in depth.展开更多
Archimedean photonic crystal has become a research area of great interest due to its various unique properties. Here, we experimentally demonstrate the realization of reconfigurable(4, 6^(2))and(4, 8^(2)) Archimedean ...Archimedean photonic crystal has become a research area of great interest due to its various unique properties. Here, we experimentally demonstrate the realization of reconfigurable(4, 6^(2))and(4, 8^(2)) Archimedean plasma photonic crystals(APPCs) by use of dielectric barrier discharges in air. Dynamical control on both the macrostructures including the lattice symmetry and the crystal orientation, and the microstructures including the fine structures of scattering elements has been achieved. The formation mechanisms of APPCs are studied by time-resolved measurements together with numerical simulations. Large omnidirectional band gaps of APPCs have been obtained. The tunable topology of APPCs may offer new opportunities for fabricating multi-functional and highly-integrated microwave devices.展开更多
Bipolar membranes(BPMs)exhibit the unique capability to regulate the operating environment of electrochemical system through the water dissociation-combination processes.However,the industrial utilization of BPMs is l...Bipolar membranes(BPMs)exhibit the unique capability to regulate the operating environment of electrochemical system through the water dissociation-combination processes.However,the industrial utilization of BPMs is limited by instability and serious energy consumption.The current-induced membrane discharge(CIMD)at high-current conditions has a negative influence on the performance of anion-exchange membranes,but the underlying ion transport mechanisms in the BPMs remain unclear.Here,the CIMD-coupled Poisson-Nernst-Planck(PNP)equations are used to explore the ion transport mechanisms in the BPMs for both reverse bias and forward bias at neutral and acid-base conditions.It is demonstrated that the CIMD effect in the reverse-bias mode can be suppressed by enhancing the diffusive transport of salt counter-ions(Na^(+)and Cl^(−))into the BPMs,and that in the forward-bias mode with acid-base electrolytes can be suppressed by matching the transport rate of water counter-ions(H_(3)O^(+)and OH^(−)).Suppressing the CIMD can promote the water dissociation in the reverse-bias mode,as well as overcome the plateau of limiting current density and reduce the interfacial blockage of salt co-ions(Cl^(−))in the anion-exchange layer in the forward-bias mode with acid-base electrolytes.Our work highlights the importance of regulating ion crossover transport on improving the performance of BPMs.展开更多
Discharge plasmas, recognized as unique platforms for investigating the origins of chemical life, have garnered extensive interest for their potential to simulate prebiotic conditions. This paper embarks on a comprehe...Discharge plasmas, recognized as unique platforms for investigating the origins of chemical life, have garnered extensive interest for their potential to simulate prebiotic conditions. This paper embarks on a comprehensive overview of recent advancements in the plasma-enabled synthesis of life’s building blocks, charting the complex environmental parameters believed to have surrounded life’s inception. This discussion elaborates on the fundamental mechanisms of discharge plasmas and their likely role in fostering conditions necessary for the origin of life on early Earth. We consider a variety of chemical reactions facilitated by plasma, specifically the synthesis of vital organic molecules - amino acids, nucleobases, sugars, and lipids. Further, we delve into the impact of plasmas on prebiotic chemical evolution. We expect this review to open new horizons for future investigations in plasma-related prebiotic chemistry that could offer valuable insights for unraveling the mysteries of life's origin.展开更多
The discharge characteristics and mechanism of sub-millimeter pulsed dielectric barrier discharge in atmosphericpressure helium are investigated experimentally and theoretically, demonstrating that when the discharge ...The discharge characteristics and mechanism of sub-millimeter pulsed dielectric barrier discharge in atmosphericpressure helium are investigated experimentally and theoretically, demonstrating that when the discharge gap distance is reduced from 1.00 mm to 0.20 mm, the discharge ignition time is reduced to approximately 40 ns and discharge intensity is enhanced in terms of the discharge optical emission intensity and density of the plasma species,(energetic electrons with energy above 8.40 e V). The simulated results show that as the discharge gap distance is further reduced to 0.10 mm,the number of energetic electrons decreases, which is attributable to the contraction of plasma bulk regime and reduction of electron density in the discharge bulk. Conversely, the proportion of energetic electrons to the total electrons in the discharge monotonically increases as the discharge gap distance is reduced from 1.00 mm to 0.10 mm. It is proposed that a gap distance of 0.12 mm is optimal to achieve a high concentration and proportion of energetic electrons in sub-millimeter pulsed atmosphere dielectric barrier discharge.展开更多
文摘Background:This study aims to investigate the application and effect of a new daytime surgery and same-day discharge mode in cataract clinic.Methods:Two hundred patients with cataract intended to undertake daytime surgery from August 2019 to January 2020 in the Cataract department were enrolled for the study.Among them,100 patients from January 2020 with the new daytime surgery and same-day discharge were the experimental group.While the other 100 patients without the designated set-up from August 2019 worked as a control group.The length and cost of hospitalization,the length of waiting for the elevator,the patient satisfaction,and the awareness rate of health education were evaluated.Results:After application of the new daytime surgery and same-day discharge set-up,the patients’satisfaction rate increased from 91%to 95%,and the rate of awareness of health education increased from 87%to 90%,the difference was statistically significant(χ^(2)=0.61,P=0.04 andχ^(2)=0.22,P=0.01).The length of hospitalization,hospitalization costs and waiting time for elevators were much reduced than those without this set-up.Conclusions:The application of the cataract daytime surgery and same-day discharge set-up can effectively alleviate the overcrowding of the ward environment,reduce the workload of medical staff,and improve patient satisfaction.Therefore,the daytime surgery and same-day discharge set-up has wide clinical applications.
基金Wu Jie-Ping Medical Foundation Special Fund for Clinical Research,No.320.6750.2021-04-71Open Research Fund of NHC Key Laboratory of Prevention and Treatment of Central Asia High Incidence Diseases,No.KF202101+3 种基金Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences,No.2020-PT330-003Beijing Hospitals Authority Clinical Medicine Development of Special Funding Support,No.XMLX202143Capital’s Funds for Health Improvement and Research,No.2020-2-2155Beijing Municipal Administration of Hospitals Incubating Program,No.PX2020047.
文摘BACKGROUND Endoscopic submucosal dissection(ESD)is an established technique for the treatment of early gastrointestinal neoplasia.Generally,multi-day(M-D)admission is required for patients undergoing ESD due to potential complications.AIM To evaluate the feasibility of a same-day(S-D)discharge strategy for ESD of the esophagus or stomach.METHODS The data of patients who underwent esophageal or gastric ESD were retrospectively collected from January 2018 to December 2021 at Peking University Cancer Hospital.The propensity score matching(PSM)method was applied to balance the unevenly distributed patient baseline characteristics between the S-D and M-D groups.Intraoperative and postoperative parameters were compared between the matched groups.RESULTS Among the 479 patients reviewed,470 patients,including 91 in the S-D group and 379 in the M-D group,fulfilled the inclusion and exclusion criteria.Following PSM,78 patients in each group were paired using the 1:1 nearest available score match algorithm.No significant difference was found between groups with respect to intraoperative and postprocedural major adverse events(AEs).Tumor size,complete resection rate,and procedural duration were comparable between the groups.The S-D group demonstrated a significantly shorter length of hospital stay(P<0.001)and lower overall medical expenses(P<0.001)compared with the M-D group.CONCLUSION The S-D discharge strategy may be feasible and effective for esophagogastric ESD,and the procedural-related AEs can be managed successfully.
文摘The adoption of transradial access in the United States and internationally has been growing over the past few years.In the population of patients presenting with acute coronary syndromes,particularly ST-elevation myocardial infarction,transradial access has the benefit of fewer vascular and bleeding complications and lower mortality rates over transfemoral access.We will examine the current evidence supporting transradial access for several patient populations,including those patients presenting with acute coronary syndromes.We will review the literature regarding the learning curve for transradial access with new operators,as well as experienced transfemoral operators new to transradial access.Finally,we will investigate the role of transradial access in same-day discharge for stable patients undergoing percutaneous coronary intervention.
基金National Natural Science Foundation of China (Grant Nos. 52277151 and 51907088)。
文摘Sustainable nitrogen fixation driven by renewable energy sources under mild conditions has been widely sought to replace the industrial Haber-Bosch process.The fixation of nitrogen in the form of NO_(x)^(-)and NH_4^(+)into aqueous solutions using electricity-driven gas-liquid discharge plasma is considered a promising prescription.In this paper,a scalable bubble discharge excited by nanosecond pulse power is employed for nitrogen fixation in the liquid phase.The nitrogen fixation performance and the mechanisms are analyzed by varying the power supply parameters,working gas flow rate and composition.The results show that an increase in voltage and frequency can result in an enhanced NO_(3)^(-)yield.Increases in the gas flow rate can result in inadequate activation of the working gas,which together with more inefficient mass transfer efficiencies can reduce the yield.The addition of O_(2) effectively elevates NO_(3)^(-)production while simultaneously inhibiting NH_4^(+) production.The addition of H_(2)O vapor increases the production of OH and H,thereby promoting the generation of reactive nitrogen and enhancing the yield of nitrogen fixation.However,the excessive addition of O_(2) and H_(2)O vapor results in negative effect on the yield of nitrogen fixation,due to the significant weakening of the discharge intensity.The optimal nitrogen fixation yield was up to 16.5 μmol/min,while the optimal energy consumption was approximately 21.3 MJ/mol in this study.Finally,the mechanism related to nitrogen fixation is discussed through the optical emission spectral(OES) information in conjunction with the simulation of energy loss paths in the plasma by BOLSIG+.The work advances knowledge of the effect of parameter variations on nitrogen fixation by gas-liquid discharge for higher yield and energy production.
基金support from the Department of Science and Technology (DST),Government of India (Grant No.ECR/DST/2017/000918)the Indian Institute of Technology Ropar for providing financial support under an ISIRD grant (F.No.9-282/2017IITRPR/705).
文摘Ultrasonic-assisted micro-electro-discharge machining(EDM)has the potential to enhance processing responses such as material removal rate(MRR)and surface finish.To understand the reasons for this enhancement,the physical mechanisms responsible for the individual discharges and the craters that they form need to be explored.This work examines features of craters formed by single discharges at various parameter values in both conventional and ultrasonic-assistedEDM of Ti6Al4V.High-speed imaging of the plasma channel is performed,and data on the individual discharges are captured in real-time.A 2D axisymmetric model using finite element software is established to model crater formation.On the basis of simulation and experimental results,a comparative study is then carried out to examine the effects of ultrasonic vibrational assistance on crater geometry.For every set ofEDM parameters,the crater diameter and depth from a single discharge are found to be higher in ultrasonic-assistedEDM than in conventionalEDM.The improved crater geometry and the reduced bulge formation at the crater edges are attributed to the increased melt pool velocity and temperature predicted by the model.
基金supported by National Natural Science Foundation of China(Nos.52037004 and 52177148)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX23_1449).
文摘Dielectric barrier discharge(DBD)is considered as a promising technique to produce large volume uniform plasma at atmospheric pressure,and the dielectric barrier layer between the electrodes plays a key role in the DBD processes and enhancing discharge uniformity.In this work,the uniformity and discharge characteristics of the nanosecond(ns)pulsed DBD with dielectric barrier layers made of alumina,quartz glass,polycarbonate(PC),and polypropylene(PP)are investigated via discharge image observation,voltage-current waveform measurement and optical emission spectral diagnosis.Through analyzing discharge image by gray value standard deviation method,the discharge uniformity is quantitatively calculated.The effects of the space electric field intensity,the electron density(Ne),and the space reactive species on the uniformity are studied with quantifying the gap voltage Ug and the discharge current Ig,analyzing the recorded optical emission spectra,and simulating the temporal distribution of Ne with a one-dimensional fluid model.It is found that as the relative permittivity of the dielectric materials increases,the space electric field intensity is enhanced,which results in a higher Ne and electron temperature(Te).Therefore,an appropriate value of space electric field intensity can promote electron avalanches,resulting in uniform and stable plasma by the merging of electron avalanches.However,an excessive value of space electric field intensity leads to the aggregation of space charges and the distortion of the space electric field,which reduce the discharge uniformity.The surface roughness and the surface charge decay are measured to explain the influences of the surface properties and the second electron emission on the discharge uniformity.The results in this work give a comprehensive understanding of the effect of the dielectric materials on the DBD uniformity,and contribute to the selection of dielectric materials for DBD reactor and the realization of atmospheric pressure uniform,stable,and reactive plasma sources.
基金financial support from the Interdisciplinary Fund of the Wuhan National High Magnetic Field Center (No. WHMFC202101)。
文摘The discharge morphology of pulsed dielectric barrier discharge(PDBD) plays important roles in its applications. Here, we systematically investigated the effects of the voltage amplitude,discharge gap, and O_(2)content on the PDBD morphology, and revealed the possible underlying mechanism of the U-shaped formation. First, the morphological evolution under different conditions was recorded. A unique U-shaped region appears in the middle edge region when the gap is larger than 2 mm, while the entire discharge region remains columnar under a 2 mm gap in He PDBD. The width of the discharge and the U-shaped region increase with the increase in voltage, and decrease with the increase of the gap and O_(2)content. To explain this phenomenon,a two-dimensional symmetric model was developed to simulate the spatiotemporal evolution of different species and calculate the electric thrust. The discharge morphology evolution directly corresponds to the excited-state atomic reduction process. The electric thrust on the charged particles mainly determines the reaction region and strongly influences the U-shaped formation.When the gap is less than 2 mm, the electric thrust is homogeneous throughout the entire region,resulting in a columnar shape. However, when the gap is larger than 2 mm or O_(2)is added, the electric thrust in the edge region becomes greater than that in the middle, leading to the U-shaped formation. Furthermore, in He PDBD, the charged particles generating electric thrust are mainly electrons and helium ions, while in He/O_(2)PDBD those that generate electric thrust at the outer edge of the electrode surface are mainly various oxygen-containing ions.
文摘Background: An abnormal vaginal discharge is a common complaint among women of reproductive age, and it can indicate serious conditions like pelvic inflammatory disease and cervical cancer. This study aimed to assess the predictors of abnormal vaginal discharge in women of reproductive age group in Imo State, Southeast Nigeria. Methods: A cross-sectional study was conducted among 368 women of reproductive age group attending the clinic at Federal University Teaching Hospital Owerri, in Imo State, Nigeria. Respondents were recruited using a systematic sampling technique. Data were collected using a pre-tested interviewer-administered questionnaire. Multivariable analysis was performed to determine predictors of abnormal vaginal discharge. Statistical significance was set at p Results: The mean age of the respondents was 30 ± 4.5 years. Predictors of abnormal vaginal discharge were: age 36 - 45 years (OR: 4.5;95% C.I: 1.023 - 8.967, p = 0.041), being a student (OR: 2.4: 95% C.I: 1.496 - 7.336, p = 0.003), use of oral contraceptives (OR: 3.4;95% C.I: 1.068 - 6.932, p = 0.010), use of water cistern (OR: 4.7;C.I: 1.654 - 5.210, p = 0.028) anal hygiene practices (OR: 2.7;95% C.I: 1.142 - 4.809, p Conclusion: These findings suggest that targeted sexual and reproductive health interventions should be provided to reduce the risk of abnormal vaginal discharge in women of reproductive age group.
基金supported by 173 Program of China,and National Natural Science Foundation of China(No.92271116).
文摘In this work,a gas-solid two-phase gliding arc discharge(GS-GAD)reactor was built.Gliding arc was formed in the gap between the blade electrodes,and solid powder was deposited on the sieve plate positioned beneath the blade electrodes.A range of experimental parameters,including the inter-electrode spacing,gas flow rate,applied voltage,and the type of the powder,were systematically varied to elucidate the influence of solid powder matter on the dynamics of gliding arc discharge(GAD).The discharge images were captured by ICCD and digital camera to investigate the mass transfer characteristics of GS-GAD,and the electrical parameters,such as the effective values of voltage,current,and discharge power were record to reveal the discharge characteristics of GS-GAD.The results demonstrate that powder undergoes spontaneous movement towards the upper region of the gliding arc due to the influence of electric field force.Increasing the discharge voltage,decreasing relative dielectric constant of the powder and reducing the electrode-to-sieve-plate distance all contribute to a greater involvement of powder in the GAD process,subsequently resulting in an enhanced powder concentration within the GAD region.Additionally,powder located beneath the gliding arc experiences downward resistance caused by the opposing gas flow and arc.Excessive gas flow rate notably hampers the powder concentration within the discharge region,and the velocity of powder motion in the upper part of the GAD region is reduced.Under the condition of electrode-to-sieve-plate distance of 30 mm,gas flow rate of 1.5 L/min,and peak-to-peak voltage of 31 kV,the best combination of arc gliding and powder spark discharge phenomena can be achieved with the addition of Al_(2)O_(3) powder.
基金provided by the shale gas resource evaluation methods and exploration technology research project of the National Science and Technology Major Project of China(No.2016ZX05034)Graduate Innovative Engineering Funding Project of China University of Petroleum(East China)(No.YCX2021109)。
文摘It is difficult to determine the discharge stages in a fixed time of repetitive discharge underwater due to the arc formation process being susceptible to external environmental influences. This paper proposes a novel underwater discharge stage identification method based on the Strong Tracking Filter(STF) and impedance change characteristics. The time-varying equivalent circuit model of the discharge underwater is established based on the plasma theory analysis of the impedance change characteristics and mechanism of the discharge process. The STF is used to reduce the randomness of the impedance of repeated discharges underwater, and then the universal identification resistance data is obtained. Based on the resistance variation characteristics of the discriminating resistance of the pre-breakdown, main, and oscillatory discharge stages, the threshold values for determining the discharge stage are obtained. These include the threshold values for the resistance variation rate(K) and the moment(t).Experimental and error analysis results demonstrate the efficacy of this innovative method in discharge stage determination, with a maximum mean square deviation of Scrless than 1.761.
基金supported by Guizhou Province (Ceneral), grant/award number Qian Ke He Zhi Cheng [2022] General 207, National Natural Science Foundation of China (No. 52307170)Natural Science Foundation of Hubei Province, China (No. 2023AFB382)。
文摘SF_(6) has excellent insulation performance and arc extinguishing ability,and is widely used in the power industry.However,its global warming potential is about 23,500 times that of C0_(2),it can exist stably in the atmosphere,it is not easily degradable and is of great potential harm to the environment.Based on pulsed dielectric barrier discharge plasma technology,the effects of H_(2)O and 0_(2) on the degradation of SF_(6) were studied.Studies have shown that H_(2)O can effectively promote the decomposition of SF_(6) and improve its degradation rate and energy efficiency of degradation.Under the action of a pulse input voltage and input frequency of 15 kV and 15 kHz,respectively,when H_(2)O is added alone the effect of 1% H_(2)O is the best,and the rate and energy efficiency of degradation of SF_(6) reach their maximum values,which are 91.9% and 8.25 g kWh^(-1),respectively.The synergistic effect of H_(2)O and O_(2) on the degradation of SF_(6) was similar to that of H_(2)O.When the concentration of H_(2)O and O_(2) was 1%,the system obtained the best rate and energy efficiency of degradation,namely 89.7% and 8.05 g kWh~(-1),respectively.At the same time,different external gases exhibit different capabilities to regulate decomposition products.The addition of H_(2)O can effectively improve the selectivity of S0_(2).Under the synergistic effect of H_(2)O and O_(2),with increase in O_(2) concentration the degradation products gradually transformed into SO_(2)F_(2).From the perspective of harmless treatment of the degradation products of SF_(6),the addition of O_(2) during the SF_(6) degradation process should be avoided.
基金supported by Province Key R&D Program of Heilongjiang(No.JD22A005)National Natural Science Foundation of China(Nos.12175050 and 12205067)。
文摘This work presents an analysis of the research conducted in many countries in recent years on the so-called Gatchina discharge.The findings indicate that the Gatchina discharge exhibits the majority of the characteristics of natural ball lightning,making it the most effective method for reproducing and studying this phenomenon.To a large extent,our new results are based on experiments performed for the first time to visualize dust particles arising in an erosive emission,as well as the formation of vortex flows.These experiments make it possible to explain the ability of the Gatchina discharge to maintain its shape for a long time in the afterglow.
基金supported by the National Key Research and Development Program of China(No.2020YFC2201004)National Natural Science Foundation of China(No.12172110)。
文摘Ionic liquid electrospray(ILE) in an atmospheric environment is often accompanied by the gas discharge phenomenon. It interferes with the normal operation of the electrospray and the measurement of experimental parameters. In this study, electrospray experiments were conducted on the ionic liquid EMI-BF4. The observations revealed that the operating modes of the ionic liquid depend on the voltage polarity at high voltages. Additionally, a correspondence between the operating mode of ILE and the current signal in the circuit was established. The shape of the liquid cone formed at the needle tip bore a striking resemblance to the plume of corona discharge, suggesting that the motion trajectory of electrons influenced the curvature of the liquid cone. Steamer theory provided a clear explanation for the change in curvature as the voltage increased.
基金supported by the National Natural Science Foundation of China(Grant Nos.:51901153)Shanxi Scholarship Council of China(Grant No.:2019032)+1 种基金Natural Science Foundation of Shanxi(Grant No.:202103021224049)the Science and Technology Major Project of Shanxi Province(Grant No.:20191102008,20191102007)。
文摘The influence of micro-Ca/In alloying on the microstructural charac teristics,electrochemical behaviors and discharge properties of extruded dilute Mg-0.5Bi-0.5Sn-based(wt.%)alloys as anodes for Mg-air batteries are evaluated.The grain size and texture intensity of the Mg-Bi-Sn-based alloys are significantly decreased after the Ca/In alloying,particularly for the In-containing alloy.Note that,in addition to nanoscale Mg_(3)Bi_(2)phase,a new microscale Mg_(2)Bi_(2)Ca phase forms in the Ca-containing alloy.The electrochemical test results demonstrate that Ca/In micro-alloying can enhance the electrochemical activity.Using In to alloy the Mg-Bi-Sn-based alloy is effective in restricting the cathodic hydrogen evolution(CHE)kinetics,leading to a low self-corrosion rate,while severe CHE occurred after Ca alloying.The micro-alloying of Ca/In to Mg-Bi-Sn-based alloy strongly deteriorates the compactness of discharge products film and mitigates the"chunk effect"(CE),hence the cell voltage,anodic efficiency as well as discharge capacity are greatly improved.The In-containing alloy exhibits outstanding discharge performance under the combined effect of the modified microstructure and discharge products,thus making it a potential anode material for primary Mg-air battery.
基金funded by the National Natural Science Foundation of China(Grant No.42201095)the Second Tibetan Plateau Scientific Expedition and Research(STEP)Program(Grant No.2019QZKK0902)the Postdoctoral Special Funding Project of Sichuan Province(Funding No.TB2023028).
文摘For the basins with debris flow development,its channel terrain exhibits a tortuous shape,which significantly restricts the movement of debris flows and leads to severe erosion effects on the concave bank.Therefore,this study aims to analyze the shear force of debris flows within the bend channel.We established the relationship between the shear force and bend curvature through laboratory experiments.Under the long-term erosion by debris flows,the curvature radius of bends gradually increases,however,when this increasing trend reaches an equilibrium state with the intensity of debris flow discharge,there will be no significant change in curvature radius.In general,the activity pattern and discharges of debris flows would remain relatively stable.Hence,we can infer the magnitude of debris flow discharges from the terrain parameters of the bend channel.
基金supported by the Ministry of Science,Technology and Innovation,Malaysia(MOSTI)(No.04-02-12-SF0339)。
文摘As the size of satellites scales down, low-power and compact propulsion systems such as the pulsed plasma thruster(PPT) are needed for stabilizing these miniature satellites in orbit. Most PPT systems are operated at 2 J or more of discharge energy. In this work, the performance of a PPT with a side-fed, tongue-flared electrode configuration operated within a lower discharge energy range of 0.5-2.5 J has been investigated. Ablation and charring of the polytetrafluoroethylene propellant surface were analyzed through field-effect scanning electron microscopy imaging and energy-dispersive X-ray spectroscopy. When the discharge energy fell below 2 J, inconsistencies occurred in the specific impulse and the thrust efficiency due to the measurement of the low mass bit. At energy ≥2 J, the performance parameters are compared with other PPT systems of similar configuration and discussed in depth.
基金supported by National Natural Science Foundation of China(Nos.12275065 and 11975089)Natural Science Foundation of Hebei Province(Nos.A2021201010 and A2021201003)+4 种基金Interdisciplinary Research Program of Natural Science of Hebei University(No.DXK202108)Hebei Provincial Central Government Guiding Local Science and Technology Development Funds(No.236Z1501G)Scientific Research and Innovation Team Foundation of Hebei University(No.IT2023B03)The Excellent Youth Research Innovation Team of Hebei University(No.QNTD202402)Regional Key Projects of National Natural Science Foundation of China(No.U23A20678).
文摘Archimedean photonic crystal has become a research area of great interest due to its various unique properties. Here, we experimentally demonstrate the realization of reconfigurable(4, 6^(2))and(4, 8^(2)) Archimedean plasma photonic crystals(APPCs) by use of dielectric barrier discharges in air. Dynamical control on both the macrostructures including the lattice symmetry and the crystal orientation, and the microstructures including the fine structures of scattering elements has been achieved. The formation mechanisms of APPCs are studied by time-resolved measurements together with numerical simulations. Large omnidirectional band gaps of APPCs have been obtained. The tunable topology of APPCs may offer new opportunities for fabricating multi-functional and highly-integrated microwave devices.
基金sponsored by the National Key R&D Program of China(2022YFB4602101)the Fundamental Research Funds for the Central Universities(2022ZFJH004 and 2024SMECP05)+2 种基金the National Natural Science Foundation of China(22278127 and 22378112)the Shanghai Pilot Program for Basic Research(22T01400100-18)the Postdoctoral Fellowship Program of CPSF(GZC20230801)。
文摘Bipolar membranes(BPMs)exhibit the unique capability to regulate the operating environment of electrochemical system through the water dissociation-combination processes.However,the industrial utilization of BPMs is limited by instability and serious energy consumption.The current-induced membrane discharge(CIMD)at high-current conditions has a negative influence on the performance of anion-exchange membranes,but the underlying ion transport mechanisms in the BPMs remain unclear.Here,the CIMD-coupled Poisson-Nernst-Planck(PNP)equations are used to explore the ion transport mechanisms in the BPMs for both reverse bias and forward bias at neutral and acid-base conditions.It is demonstrated that the CIMD effect in the reverse-bias mode can be suppressed by enhancing the diffusive transport of salt counter-ions(Na^(+)and Cl^(−))into the BPMs,and that in the forward-bias mode with acid-base electrolytes can be suppressed by matching the transport rate of water counter-ions(H_(3)O^(+)and OH^(−)).Suppressing the CIMD can promote the water dissociation in the reverse-bias mode,as well as overcome the plateau of limiting current density and reduce the interfacial blockage of salt co-ions(Cl^(−))in the anion-exchange layer in the forward-bias mode with acid-base electrolytes.Our work highlights the importance of regulating ion crossover transport on improving the performance of BPMs.
基金National Natural Science Foundation of China General Project(52377160)National Natural Science Foundation of China National Young Talents Project(GYKP010)+1 种基金Shaanxi Provincial Natural Science Program(2023-JC-YB-425)Xi′an Jiaotong University Young Top Talents Program.
文摘Discharge plasmas, recognized as unique platforms for investigating the origins of chemical life, have garnered extensive interest for their potential to simulate prebiotic conditions. This paper embarks on a comprehensive overview of recent advancements in the plasma-enabled synthesis of life’s building blocks, charting the complex environmental parameters believed to have surrounded life’s inception. This discussion elaborates on the fundamental mechanisms of discharge plasmas and their likely role in fostering conditions necessary for the origin of life on early Earth. We consider a variety of chemical reactions facilitated by plasma, specifically the synthesis of vital organic molecules - amino acids, nucleobases, sugars, and lipids. Further, we delve into the impact of plasmas on prebiotic chemical evolution. We expect this review to open new horizons for future investigations in plasma-related prebiotic chemistry that could offer valuable insights for unraveling the mysteries of life's origin.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12175036 and 11875104)。
文摘The discharge characteristics and mechanism of sub-millimeter pulsed dielectric barrier discharge in atmosphericpressure helium are investigated experimentally and theoretically, demonstrating that when the discharge gap distance is reduced from 1.00 mm to 0.20 mm, the discharge ignition time is reduced to approximately 40 ns and discharge intensity is enhanced in terms of the discharge optical emission intensity and density of the plasma species,(energetic electrons with energy above 8.40 e V). The simulated results show that as the discharge gap distance is further reduced to 0.10 mm,the number of energetic electrons decreases, which is attributable to the contraction of plasma bulk regime and reduction of electron density in the discharge bulk. Conversely, the proportion of energetic electrons to the total electrons in the discharge monotonically increases as the discharge gap distance is reduced from 1.00 mm to 0.10 mm. It is proposed that a gap distance of 0.12 mm is optimal to achieve a high concentration and proportion of energetic electrons in sub-millimeter pulsed atmosphere dielectric barrier discharge.