Electric field is an important parameter of plasma,which is related to electron temperature,electron density,excited species density,and so on.In this work,the electric field of an atmospheric pressure plasma jet is d...Electric field is an important parameter of plasma,which is related to electron temperature,electron density,excited species density,and so on.In this work,the electric field of an atmospheric pressure plasma jet is diagnosed by the electric field induced second harmonic(E-FISH)method,and the time-resolved electric field under different conditions is investigated.When positive pulse voltage is applied,the electric field has a peak of about 25 kV cm-1at the rising edge of the voltage pulse.A dark channel is left behind the plasma bullet and the electric field in the dark channel is about 5 kV cm-1.On the other hand,when negative pulse voltage is applied,the electric field has a peak of-16 kV cm-1when the negative voltage is increased to-8 kV.A relatively bright channel is left behind the plasma head and the electric field in this relatively bright channel is about-6 kV cm-1.When the pulse rising time increases from 60 to 200 ns,the peak electric field at both the rising edge and the falling edge of the voltage decreases significantly.When 0.5%of oxygen is added to the main working gas helium,the peak electric field at the rising edge is only about 15 kV cm-1.On the other hand,when 0.5%nitrogen is added,the peak electric field increases especially at the falling edge of the voltage pulse,where it increases reversely from-12 to-16 kV cm-1(the minus sign only represents the direction of electric field).展开更多
The shuttle effect of lithium polysulfides(LiPSs)and uncontrollable lithium dendrite growth seriously hinder the practical application of lithium-sulfur(Li-S)batteries.To simultaneously address such issues,monodispers...The shuttle effect of lithium polysulfides(LiPSs)and uncontrollable lithium dendrite growth seriously hinder the practical application of lithium-sulfur(Li-S)batteries.To simultaneously address such issues,monodispersed Nb N quantum dots anchored on nitrogen-doped hollow carbon nanorods(NbN@NHCR)are elaborately developed as efficient Li PSs immobilizer and Li stabilizer for high-performance Li-S full batteries.Density functional theory(DFT)calculations and experimental characterizations demonstrate that the sulfiphilic and lithiophilic NbN@NHCR hybrid can not only efficiently immobilize the soluble Li PSs and facilitate diffusion-conversion kinetics for alleviating the shuttling effect,but also homogenize the distribution of Li+ions and regulate uniform Li deposition for suppressing Li-dendrite growth.As a result,the assembled Li-S full batteries(NbN@NHCR-S||Nb N@NHCR-Li)deliver excellent long-term cycling stability with a low decay rate of 0.031%per cycle over 1000 cycles at high rate of 2 C.Even at a high S loading of 5.8 mg cm^(-2)and a low electrolyte/sulfur ratio of 5.2μL mg^(-1),a large areal capacity of 6.2 mA h cm^(-2)can be achieved in Li-S pouch cell at 0.1 C.This study provides a new perspective via designing a dual-functional sulfiphilic and lithiophilic hybrid to address serious issues of the shuttle effect of S cathode and dendrite growth of Li anode.展开更多
This paper presented a novel tinny motion capture system for measuring bird posture based on inertial and magnetic measurement units that are made up of micromachined gyroscopes, accelerometers, and magnetometers. Mul...This paper presented a novel tinny motion capture system for measuring bird posture based on inertial and magnetic measurement units that are made up of micromachined gyroscopes, accelerometers, and magnetometers. Multiple quaternion-based extended Kalman filters were implemented to estimate the absolute orientations to achieve high accuracy.Under the guidance of ornithology experts, the extending/contracting motions and flapping cycles were recorded using the developed motion capture system, and the orientation of each bone was also analyzed. The captured flapping gesture of the Falco peregrinus is crucial to the motion database of raptors as well as the bionic design.展开更多
Plasma-enhanced transdermal drug delivery(TDD) presents advantages over traditional methods,including painless application, minimal skin damage, and rapid recovery of permeability. To harness its clinical potential, f...Plasma-enhanced transdermal drug delivery(TDD) presents advantages over traditional methods,including painless application, minimal skin damage, and rapid recovery of permeability. To harness its clinical potential, factors related to plasma’s unique properties, such as reactive species and electric fields, must be carefully considered.This review provides a concise summary of conventional TDD methods and subsequently offers a comprehensive examination of the current state-of-the-art in plasma-enhanced TDD. This includes an analysis of the impact of plasma on HaCaT human keratinocyte cells, ex vivo/in vivo studies, and clinical research on plasma-assisted TDD. Moreover, the review explores the effects of plasma on skin physical characteristics such as microhole formation, transepidermal water loss(TEWL), molecular structure of the stratum corneum(SC), and skin resistance. Additionally, it discusses the involvement of various reactive agents in plasma-enhanced TDD, encompassing electric fields,charged particles, UV/VUV radiation, heat, and reactive species. Lastly, the review briefly addresses the temporal behavior of the skin after plasma treatment, safety considerations, and potential risks associated with plasma-enhanced TDD.展开更多
Background: Trans-province transfer of the patients has been successfully carried out and has greatly relieved the burden of the hospitals in Sichuan Province after Sichuan earthquake. The aim of the study was to retr...Background: Trans-province transfer of the patients has been successfully carried out and has greatly relieved the burden of the hospitals in Sichuan Province after Sichuan earthquake. The aim of the study was to retrospectively analyze the efficacy and feasibility of the trans-province transfer of the multiple trauma patients after Sichuan earthquake. Methods: A retrospective and descriptive analysis was conducted based on the medical records of the multiple trauma patients (ISS ≥ 16) transferred to the Grade 3A hospitals outside Sichuan province. The patients were divided into two groups based on the distance to Sichuan province, i.e., Group A (the seismic patients transferred to Chongqing) and Group B (the seismic patients transferred to the other provinces/ municipalities). A comparison was done in aspects of distance of transfer, time from injury to transfer, vital signs, the infection rates (at transfer and on discharge), injury severity and prognostic indices (cure rate, disability rate and mortality). Results: The distance between Chengdu and the other places was at a wide range of 313 - 1653 km, whereas the time from injury to transfer showed no statistical difference between groups (P > 0.05). There were no significant differences between both groups with respects to patient demographics, injury mechanism, time from injury to transfer, vital signs, infection rate and injury severity. The prognostic indices showed no significant difference, except for FIM scores (P < 0.05). Conclusions: The results of the study indicate that the different distance of the transfer of the multiple trauma patients does not aggravate the severity or deteriorate the prognosis, which proves that the medical supportive transfer system is acceptable, effective and worthy of further implementation in China, which may be ascribed to the advanced transportation system and high level of therapeutic capacity of the hospitals. In the meantime, attention should be paid to psychological intervention and functional rehabilitation during the treatment of the transferred seismic patients.展开更多
Carbides/carbon composites are emerging as a new kind of binary dielectric systems with good microwave absorption performance.Herein,we obtain a series of tungsten carbide/carbon composites through a simple solvent-fr...Carbides/carbon composites are emerging as a new kind of binary dielectric systems with good microwave absorption performance.Herein,we obtain a series of tungsten carbide/carbon composites through a simple solvent-free strategy,where the solid mixture of dicyandiamide(DCA)and ammonium metatungstate(AM)is employed as the precursor.Ultrafine cubic WC1-x nanoparticles(3-4 nm)are in situ generated and uniformly dispersed on carbon nanosheets.This configuration overcomes some disadvantages of conventional carbides/carbon composites and is greatly helpful for electromagnetic dissipation.It is found that the weight ratio of DCA to AM can regulate chemical composition of these composites,while less impact on the average size of WC1-x nanoparticles.With the increase in carbon nanosheets,the relative complex permittivity and dielectric loss ability are constantly enhanced through conductive loss and polarization relaxation.The different dielectric properties endow these composites with distinguishable attenuation ability and impedance matching.When DCA/AM weight ratio is 6.0,the optimized composite can produce good microwave absorption performance,whose strongest reflection loss intensity reaches up to-55.6 dB at 17.5 GHz and qualified absorption bandwidth covers 3.6-18.0 GHz by manipulating the thickness from 1.0 to 5.0 mm.Such a performance is superior to many conventional carbides/carbon composites.展开更多
Background: Improving the feed efficiency would increase profitability for producers while also reducing the environmental footprint of livestock production. This study was conducted to investigate the relationships a...Background: Improving the feed efficiency would increase profitability for producers while also reducing the environmental footprint of livestock production. This study was conducted to investigate the relationships among feed efficiency traits and metabolizable efficiency traits in 180 male broilers. Significant loci and genes affecting the metabolizable efficiency traits were explored with an imputation-based genome-wide association study. The traits measured or calculated comprised three growth traits, five feed efficiency related traits, and nine metabolizable efficiency traits.Results: The residual feed intake(RFI) showed moderate to high and positive phenotypic correlations with eight other traits measured, including average daily feed intake(ADFI), dry excreta weight(DEW), gross energy excretion(GEE), crude protein excretion(CPE), metabolizable dry matter(MDM), nitrogen corrected apparent metabolizable energy(AMEn), abdominal fat weight(Ab F), and percentage of abdominal fat(Ab P). Greater correlations were observed between growth traits and the feed conversion ratio(FCR) than RFI. In addition, the RFI, FCR, ADFI, DEW,GEE, CPE, MDM, AMEn, Ab F, and Ab P were lower in low-RFI birds than high-RFI birds(P < 0.01 or P < 0.05), whereas the coefficients of MDM and MCP of low-RFI birds were greater than those of high-RFI birds(P < 0.01). Five narrow QTLs for metabolizable efficiency traits were detected, including one 82.46-kb region for DEW and GEE on Gallus gallus chromosome(GGA) 26, one 120.13-kb region for MDM and AMEn on GGA1, one 691.25-kb region for the coefficients of MDM and AMEn on GGA5, one region for the coefficients of MDM and MCP on GGA2(103.45–103.53 Mb), and one 690.50-kb region for the coefficient of MCP on GGA14. Linkage disequilibrium(LD) analysis indicated that the five regions contained high LD blocks, as well as the genes chromosome 26 C6 orf106 homolog(C26 H6 orf106), LOC396098, SH3 and multiple ankyrin repeat domains 2(SHANK2), ETS homologous factor(EHF), and histamine receptor H3-like(HRH3 L), which are known to be involved in the regulation of neurodevelopment, cell proliferation and differentiation, and food intake.Conclusions: Selection for low RFI significantly decreased chicken feed intake, excreta output, and abdominal fat deposition, and increased nutrient digestibility without changing the weight gain. Five novel QTL regions involved in the control of metabolizable efficiency in chickens were identified. These results, combined through nutritional and genetic approaches, should facilitate novel insights into improving feed efficiency in poultry and other species.展开更多
Objective To investigate the effect of target-and-endpoint protocol on the resuscitation of septic patients.Methods This is a retrospective study performed at the Peking Union Medical College Hospital Intensive Care U...Objective To investigate the effect of target-and-endpoint protocol on the resuscitation of septic patients.Methods This is a retrospective study performed at the Peking Union Medical College Hospital Intensive Care Unit.We enrolled 545 septic patients who needed vasopressors on at least the first day of ICU admission.The general characteristics,blood lactate level,mean arterial pressure(MAP),central venous pressure(CVP)and saturation of central venous oxygen(ScvO2)at admission and 6,24 hours after admission were collected.The parameters at different time points were compared.Lactate clearance rate and in-hospital mortality were analyzed.Results The 6-hour lactate clearance rate was 21.6%(IQR,8.6%-39.0%),and in-hospital mortality was 9.4%.For patients with low CVP values(<8 mm Hg,1 mm Hg=0.133 kPa)at admission,CVP increased significantly at 6 hours after admission(5.4±1.6 mm Hg vs.7.7±2.6 mm Hg,P<0.001).For patients with low MAP(<75 mm Hg)at admission,the MAP values increased significantly at 6 hours(64.2±7.1 mm Hg vs.82.2±13.1 mm Hg,P<0.001).For patients with low ScvO2 value(<70%)at admission,the ScvO2 value increased significantly at 6 hours(61.9%±7.0%vs.71.9%±7.8%,P<0.001).No difference was found between the values at 6 hours and the corresponding values at 24 hours after admission.For patients with high CVP values(≥8 mm Hg)at admission,CVP decreased significantly at 6 hours(11.3±4.0 mm Hg vs.10.3±2.9 mm Hg,P<0.001).For patients with high MAP(≥75 mm Hg)at admission,the MAP values decreased significantly at 6 hours(94.2±13.9 mm Hg vs.89.4±11.4 mm Hg,P<0.001).For patients with high ScvO2 value(≥70%)at admission,the ScvO2 values decreased significantly at 6 hours(76.8%±4.2%vs.72.9%±7.3%,P<0.001).No difference was found between the values at 6 hours and the corresponding values at 24 hours.Conclusions This study suggested that in the resuscitation of sepsis and septic shock patients in the ICU,the target values did not need to be within the“normal range”recommended by early-goal directed therapy.The“target-and-endpoint”protocol,which aimed for personalized goals,deserves more consideration.展开更多
Mesenchymal stem cells(MSCs)closely interact with the immune system,and they are known to secrete inflammatory cytokines in response to stress stimuli.The biological function of MSC-derived inflammatory cytokines rema...Mesenchymal stem cells(MSCs)closely interact with the immune system,and they are known to secrete inflammatory cytokines in response to stress stimuli.The biological function of MSC-derived inflammatory cytokines remains elusive.Here,we reveal that even under physiological conditions,MSCs produce and release a low level of tumor necrosis factor alpha(TNFα),which is unexpectedly required for preserving the self-renewal and differentiation of MSCs via autocrine/paracrine signaling.Furthermore,TNFαcritically maintains MSC function in vivo during bone homeostasis.Mechanistically,we unexpectedly discovered that physiological levels of TNFαsafeguard MSC homeostasis in a receptor-independent manner through mechanical force-driven endocytosis and that endocytosed TNFαbinds to mammalian target of rapamycin(mTOR)complex 2 and restricts mTOR signaling.Importantly,inhibition of mTOR signaling by rapamycin serves as an effective osteoanabolic therapeutic strategy to protect against TNFαdeficiency and mechanical unloading.Collectively,these findings unravel the physiological framework of the dynamic TNFαshuttlebased mTOR equilibrium that governs MSC and bone homeostasis.展开更多
Hydrogels are biomaterials with 3D networks of hydrophilic polymers.The generation of hydrogels is turning to the development of hydrogels with the help of enabling technologies.Plasma can tailor the hydrogels’proper...Hydrogels are biomaterials with 3D networks of hydrophilic polymers.The generation of hydrogels is turning to the development of hydrogels with the help of enabling technologies.Plasma can tailor the hydrogels’properties through simultaneous physical and chemical actions,resulting in an emerging technology of plasma-activated hydrogels(PAH).PAH can be divided into functional PAH and biological tissue model PAH.This review systematically introduces the plasma sources,plasma etching polymer surface,and plasma cross-linking involved in the fabrication of PAH.The‘diffusion-drift-reaction model’is used to study the microscopic physicochemical interaction between plasma and biological tissue PAH models.Finally,the main achievements of PAH,including wound treatment,sterilization,3D tumor model,etc,and their development trends are discussed.展开更多
The key to high manoeuvre ability in bird flight lies in the combined morphing of wings and tail.The perching of a wild Haliaeetus Albicilla without running or wing flapping is recorded and investigated using a high-s...The key to high manoeuvre ability in bird flight lies in the combined morphing of wings and tail.The perching of a wild Haliaeetus Albicilla without running or wing flapping is recorded and investigated using a high-speed digital video.A shape reconstruction method is proposed to describe wing contours and tail contours during perching.The avian airfoil geometries of the Aquila Chrysaetos are extracted from noncontact surface measurements using a ROMBER 3D laser scanner.The wing planform,chord distribution and twist distribution are fitted in convenient analytical expressions to obtain a 3D wing geometry.A three-jointed arm model is proposed to associate with the 3D wing geometry,while a one-joint arm model is proposed to describe the kinematics of tail.Therefore,a 3D bird model is established.The perching sequences of the wild eagle are recaptured and regenerated with the proposed 3D bird model.A quasi-steady aerodynamic model is applied in the aerodynamic predictions,a four-step Adams-Bashforth method is used to calculate the ordinary differential equations,thus a BFGS based optimization method is established to predict the perching motions.展开更多
The large dual-channel wide-bodied aircraft has a long range and a high cruise Mach number.Therefore,its aerodynamic design requires a high level ofwind tunnel test refinement.Based on the requirements of aerodynamic ...The large dual-channel wide-bodied aircraft has a long range and a high cruise Mach number.Therefore,its aerodynamic design requires a high level ofwind tunnel test refinement.Based on the requirements of aerodynamic design for the future wide-bodied aircraft and the characteristics of high-speed wind tunnel tests,the error theory is introduced to analyze the factors affecting the accuracy of the test data.This study carries out a series of research on the improvement of refined aerodynamic test technology in an FL-26 wind tunnel,including design and optimization of the support system of wide-bodied aircraft,model attitude angle measurement,Mach number control accuracy,measurement and control system stability,test data correction and perfection,high-precision force balance and standard model development.In addition,the effect of the standard specification of the refined aerodynamic test is investigated to improve the data quality.The research findings have been applied in the standard model test and subsequent models of wide-bodied aircraft.The results show that whenMach numbers are less than 0.9,the control accuracy of Mach numbers in the FL-26 wind tunnel is smaller than 0.001 and the measurement error of attack angle is smaller than 0.01°.Therefore,it has the ability to correct the data influenced by factors,such as support/wall interference,model deformation,floating resistance and airflow deflection angle.The repeatability accuracy of the standard model’s comparison test shows that the lift coefficient is less than or equal to 0.0012,the drag coefficient is less than or equal to 0.00004,pitching moment coefficient is less than or equal to 0.0004.The bending resolution of the model’s deformation measurement is less than 0.2 mm,and the tensional deformation is smaller than 0.04°.The revised aerodynamic data and model deformation measurement results have good agreement with that of the ETW wind tunnel.The results demonstrate that the improved technology presented in this paper can significantly enhance the refined aerodynamic test of wide-bodied aircraft.展开更多
Objective Focused cardiac ultrasound(FCU)and lung ultrasound(LU)are increasingly being used in critically ill patients.This study aimed to investigate the effect of FCU in combination with LU on these patients and to ...Objective Focused cardiac ultrasound(FCU)and lung ultrasound(LU)are increasingly being used in critically ill patients.This study aimed to investigate the effect of FCU in combination with LU on these patients and to determine if the timing of ultrasound examination was associated with treatment change.Methods This is a multicenter cross-sectional observational study.Consecutive patients admitted to the intensive care unit(ICU)were screened for enrollment.FCU and LU were performed within the first 24 h,and treatment change was proposed by the performer based on the ultrasound results and other clinical conditions.Results Among the 992 patients included,502 were examined within 6 h of ICU admission(early phase group),and 490 were examined after 6 h of admission(later phase group).The early phase group and the later phase group had similar proportions of treatment change(48.8%vs.49.0%,χ^(2)=0.003,P=0.956).In the multivariable analysis,admission for respiratory failure was an independent variable associated with treatment change,with an odds ratio(OR)of 2.357[95%confidence interval(CI):1.284-4.326,P=0.006];the timing of examination was not associated with treatment change(OR=0.725,95%CI:0.407-1.291,P=0.275).Conclusions FCU in combination with LU,whether performed during the early phase or later phase,had a significant impact on the treatment of critically ill patients.Patients with respiratory failure were more likely to experience treatment change after the ultrasound examination.展开更多
The corona discharges provide an efficient way to induce precipitation or eliminate fog by increasing ion density in the open air.In this paper,one bipolar corona discharge array(positive and negative high voltage cou...The corona discharges provide an efficient way to induce precipitation or eliminate fog by increasing ion density in the open air.In this paper,one bipolar corona discharge array(positive and negative high voltage coupled simultaneously)which can generate high densities of positive and negative ions is developed.The comparison between bipolar corona discharge array and unipolar corona discharge array(positive or negative coupled only)indicates that bipolar corona discharge array can generate~3 times higher ion density than unipolar corona discharge array.More charged aerosols are produced through collisions between ions and aerosols.The collision rate between aerosols is increased substantially by the attractive forces between positively and negatively charged aerosols.The deposition of aerosols induced by bipolar discharges is 25.7%higher than that of unipolar discharges at the humidity super-saturation condition.Therefore,the bipolar corona discharge system is a new option for the large scale ion sources used for artificial weather modification.展开更多
We investigate how the barb of bird feathers is changed along both the rachis and barb.To investigate the microstructures and the mechanical behaviors of barbs,a series of barbs are manually cut from an eagle’s prima...We investigate how the barb of bird feathers is changed along both the rachis and barb.To investigate the microstructures and the mechanical behaviors of barbs,a series of barbs are manually cut from an eagle’s primary feather to observe the cross sections.Aλ-like cross section with a tiny hook is observed at the right feet at each section.Afterwards,a measurement of the setup system is developed to evaluate the leakage ratio of a feather followed by a numerical predicting approach based on the CFD method.It is found that the air leakage increases linearly against the pressure,and the predicted results coincide well with the experimental results.Finally,the influences of leakage of the flight feather on both steady and unsteady aerodynamics are studied.展开更多
China’s first Mars exploration mission,Tianwen-1,successfully landed in southern Utopia Planitia on Mars on May 15,2021.This work presents a detailed investigation of the geologic context of the landing area surface ...China’s first Mars exploration mission,Tianwen-1,successfully landed in southern Utopia Planitia on Mars on May 15,2021.This work presents a detailed investigation of the geologic context of the landing area surface for this mission based on orbital remotesensing data.We constructed a geomorphologic map for the Tianwen-1 landing area.Results of our detailed geomorphologic map show several major landforms within the landing area,including rampart craters,mesas,troughs,cones,and ridges.Analysis of materials on the landing area surface indicates that most of the landing area is covered by Martian dust.Transverse aeolian ridges are widely distributed within the landing area,indicating the surface contexts were(and still are)modified by regional winds.In addition,a crater counting analysis indicates the landing area has an absolute model age of~3.3 Ga and that a later resurfacing event occurred at~1.6 Ga.Finally,we outline four formational scenarios to test the formation mechanisms for the geomorphologic features on the landing area surface.The most likely interpretation to explain the existence of the observed surface features can be summarized as follows:A thermal influence may have played an important role in the formation of the surface geomorphologic features;thus,igneous-related processes may have occurred in the landing area.Water ice may also have been involved in the construction of the primordial surface configuration.Subsequent resurfacing events and aeolian processes buried and modified the primordial surface.展开更多
Generation of atmospheric pressure homogeneous air plasma in a large gap(>4 mm)is a challenge.In this study,an atmospheric pressure homogeneous air plasma generated in a gap up to 10 mm is reported,which is based o...Generation of atmospheric pressure homogeneous air plasma in a large gap(>4 mm)is a challenge.In this study,an atmospheric pressure homogeneous air plasma generated in a gap up to 10 mm is reported,which is based on a three-electrode configuration,where a high-voltage(HV)electrode and a middle electrode form a surface dielectric barrier discharge(S-DBD),and together with the ground electrode form the main volume discharge.High-speed photographs confirm that the discharge in the main gap is homogeneous.The gas temperature of the plasma estimated from the N_(2)(C^(3)∏_(u)-B^(3)∏_(g))(Δv=-2)emission is about 320 K,which is close to room temperature.A detailed analysis shows that the discharge ignited between the HV electrode and the middle electrode is serving as an electron source,and the electrons deposited on the dielectric plate are due to the S-DBD along with the applied voltage generating a driving force,which results in a high concentration of seed electrons in the main gap and induces the homogeneous plasma.Further analysis shows that the electric field in the main gap is only about18.45 k V·cm^(-1),which is much lower than the typical breakdown electric field of 30 k V·cm^(-1)for atmospheric pressure air discharge.展开更多
Objective This study aimed to determine which parameters in transthoracic echocardiography(TTE)are more likely to be affected when applied in a critical care setting with mechanical ventilation.Methods Ninety mechanic...Objective This study aimed to determine which parameters in transthoracic echocardiography(TTE)are more likely to be affected when applied in a critical care setting with mechanical ventilation.Methods Ninety mechanically ventilated ICU patients were enrolled into the study group.The control group consisted of 90 patients who underwent interventional therapy.All patients had bedside TTE for parametric measurements including the right ventricular size,septal kinetics and left ventricular ejection fraction(LVEF)by eyeballing(visual assessment),the tricuspid annular plane systolic excursion(TAPSE),mitral annular plane systolic excursion(MAPSE)by M-mode sonography,the right ventricular outflow tract velocity-time integral(RVOT VTI)and left ventricular outflow tract velocity-time integral(LVOT VTI)by pulse-Doppler,the right ventricular fraction of area change(FAC)and left ventricular ejection fraction(LVEF Simpson)by endocardium tracing.We compared the differences in the frequency of optimal image acquisition in assessments of these parameters between the two groups,as well as the differences in acquisition rates of parameter measurements in ventilated ICU patients.Results There were significantly fewer patients in the study group than in the control group who had optimal images acquisitions for parameter assessments with M-mode method,pulse Doppler method and endocardiumtracing method(P<0.05);no significant difference was obsered in the number of patients with optimal images for RV eyeballing and LVEF eyeballing between the two groups.In the study group,significantly fewer optimal images were acquired for FAC than forTAPSE(22.2%vs、72.2%,χ2=45.139,P<0.001)and RVOT VTI(22.2%vs.71.1%,χ2=43.214,P<0.001);there were also fewer optimal images acquired for LVEF Simpson than for MAPSE(37.8%ys.84.4%,χ2=41.236,P<0.001)and LVOT VTI(37.8%vs.85.6%,/=43.455,P<0.001).Conclusions Images acquisition of optimal TTE images tend to be difRcult in mechanically ventilated ICU patients,but eyeballing method for functional evaluation could be an alternative method.For quantitative parameters measurements,M-mode based longitudinal function evaluation and pulse Doppler-based VTI were superior to the endocardium-tracing based parameter assessments.展开更多
Raptors can change the shape and area of their wings to an exceptional degree in a fast and efficient manner,surpassing other birds,insects,or bats.Some researchers have focused on the functional properties of muscle ...Raptors can change the shape and area of their wings to an exceptional degree in a fast and efficient manner,surpassing other birds,insects,or bats.Some researchers have focused on the functional properties of muscle skeletons,mechanics,and flapping robot design.However,the wing motion of the birds of prey has not been measured quantitatively,and synthetic bionic wings with morphing abilities similar to raptors are far from reality.Therefore,in the current study,a 3D suspension system for holding bird carcasses was designed and fabricated to fasten the wings of Falco Peregrinus with a series of morphing postures.Subsequently,the wing skeleton of the falcon was scanned during extending motions using the computed tomography(CT)approach to obtain three consecutive poses.Subsequently,the skeleton was reconstructed to identify the contribution of the forelimb bones to the extending/folding motions.Inspired by these findings,we propose a simple mechanical model with four bones to form a wing-morphing mechanism using the proposed pose optimisation method.Finally,a bionic wing mechanism was implemented to imitate the motion of the falcon wing—divided into inner and outer wings with folding and twisting motions.The results show that the proposed four-bar mechanism can track bone motion paths with high fidelity.展开更多
This cohort study was performed to explore the influence of intensive care unit(ICU)quality on in-hospital mortality of veno-venous(V-V)extracorporeal membrane oxygenation(ECMO)-supported patients in China.The study i...This cohort study was performed to explore the influence of intensive care unit(ICU)quality on in-hospital mortality of veno-venous(V-V)extracorporeal membrane oxygenation(ECMO)-supported patients in China.The study involved all V-V ECMO-supported patients in 318 of 1700 tertiary hospitals from 2017 to 2019,using data from the National Clinical Improvement System and China National Critical Care Quality Control Center.ICU quality was assessed by quality control indicators and capacity parameters.Among the 2563 V-V ECMO-supported patients in 318 hospitals,a significant correlation was found between ECMO-related complications and prognosis.The reintubation rate within 48 hours after extubation and the total ICU mortality rate were independent risk factors for higher in-hospital mortality of V-V ECMO-supported patients(cutoff:1.5%and 7.0%;95%confidence interval:1.05–1.48 and 1.04–1.45;odds ratios:1.25 and 1.23;P=0.012 and P=0.015,respectively).Meanwhile,the V-V ECMO center volume was a protective factor(cutoff of≥50 cases within the 3-year study period;95%confidence interval:0.57–0.83,odds ratio:0.69,P=0.0001).The subgroup analysis of 864 patients in 11 high-volume centers further strengthened these findings.Thus,ICU quality may play an important role in improving the prognosis of V-V ECMO-supported patients.展开更多
基金National Key Research and Development Program of China(No.2021YFE0114700)National Natural Science Foundation of China(Nos.52130701 and 51977096)。
文摘Electric field is an important parameter of plasma,which is related to electron temperature,electron density,excited species density,and so on.In this work,the electric field of an atmospheric pressure plasma jet is diagnosed by the electric field induced second harmonic(E-FISH)method,and the time-resolved electric field under different conditions is investigated.When positive pulse voltage is applied,the electric field has a peak of about 25 kV cm-1at the rising edge of the voltage pulse.A dark channel is left behind the plasma bullet and the electric field in the dark channel is about 5 kV cm-1.On the other hand,when negative pulse voltage is applied,the electric field has a peak of-16 kV cm-1when the negative voltage is increased to-8 kV.A relatively bright channel is left behind the plasma head and the electric field in this relatively bright channel is about-6 kV cm-1.When the pulse rising time increases from 60 to 200 ns,the peak electric field at both the rising edge and the falling edge of the voltage decreases significantly.When 0.5%of oxygen is added to the main working gas helium,the peak electric field at the rising edge is only about 15 kV cm-1.On the other hand,when 0.5%nitrogen is added,the peak electric field increases especially at the falling edge of the voltage pulse,where it increases reversely from-12 to-16 kV cm-1(the minus sign only represents the direction of electric field).
基金supported by the open research fund of Songshan Lake Materials Laboratory (2022SLABFN26)the National Natural Science Foundation of China (21773024)+1 种基金the Sichuan Science and Technology program (2020YJ0324,2020YJ0262)the Reformation and Development Funds for Local Region Universities from China Government in 2020 (ZCKJ 2020-11)。
文摘The shuttle effect of lithium polysulfides(LiPSs)and uncontrollable lithium dendrite growth seriously hinder the practical application of lithium-sulfur(Li-S)batteries.To simultaneously address such issues,monodispersed Nb N quantum dots anchored on nitrogen-doped hollow carbon nanorods(NbN@NHCR)are elaborately developed as efficient Li PSs immobilizer and Li stabilizer for high-performance Li-S full batteries.Density functional theory(DFT)calculations and experimental characterizations demonstrate that the sulfiphilic and lithiophilic NbN@NHCR hybrid can not only efficiently immobilize the soluble Li PSs and facilitate diffusion-conversion kinetics for alleviating the shuttling effect,but also homogenize the distribution of Li+ions and regulate uniform Li deposition for suppressing Li-dendrite growth.As a result,the assembled Li-S full batteries(NbN@NHCR-S||Nb N@NHCR-Li)deliver excellent long-term cycling stability with a low decay rate of 0.031%per cycle over 1000 cycles at high rate of 2 C.Even at a high S loading of 5.8 mg cm^(-2)and a low electrolyte/sulfur ratio of 5.2μL mg^(-1),a large areal capacity of 6.2 mA h cm^(-2)can be achieved in Li-S pouch cell at 0.1 C.This study provides a new perspective via designing a dual-functional sulfiphilic and lithiophilic hybrid to address serious issues of the shuttle effect of S cathode and dendrite growth of Li anode.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.52175279 and 51705459)the Natural Science Foundation of Zhejiang Province,China (Grant No.LY20E050022)the Key Research and Development Projects of Zhejiang Provincial Science and Technology Department (Grant No.2021C03122)。
文摘This paper presented a novel tinny motion capture system for measuring bird posture based on inertial and magnetic measurement units that are made up of micromachined gyroscopes, accelerometers, and magnetometers. Multiple quaternion-based extended Kalman filters were implemented to estimate the absolute orientations to achieve high accuracy.Under the guidance of ornithology experts, the extending/contracting motions and flapping cycles were recorded using the developed motion capture system, and the orientation of each bone was also analyzed. The captured flapping gesture of the Falco peregrinus is crucial to the motion database of raptors as well as the bionic design.
基金supported by National Natural Science Foundation of China(Nos.52277150,51977096,12005076 and 52130701)the National Key Research and Development Program of China(No.2021YFE0114700)。
文摘Plasma-enhanced transdermal drug delivery(TDD) presents advantages over traditional methods,including painless application, minimal skin damage, and rapid recovery of permeability. To harness its clinical potential, factors related to plasma’s unique properties, such as reactive species and electric fields, must be carefully considered.This review provides a concise summary of conventional TDD methods and subsequently offers a comprehensive examination of the current state-of-the-art in plasma-enhanced TDD. This includes an analysis of the impact of plasma on HaCaT human keratinocyte cells, ex vivo/in vivo studies, and clinical research on plasma-assisted TDD. Moreover, the review explores the effects of plasma on skin physical characteristics such as microhole formation, transepidermal water loss(TEWL), molecular structure of the stratum corneum(SC), and skin resistance. Additionally, it discusses the involvement of various reactive agents in plasma-enhanced TDD, encompassing electric fields,charged particles, UV/VUV radiation, heat, and reactive species. Lastly, the review briefly addresses the temporal behavior of the skin after plasma treatment, safety considerations, and potential risks associated with plasma-enhanced TDD.
文摘Background: Trans-province transfer of the patients has been successfully carried out and has greatly relieved the burden of the hospitals in Sichuan Province after Sichuan earthquake. The aim of the study was to retrospectively analyze the efficacy and feasibility of the trans-province transfer of the multiple trauma patients after Sichuan earthquake. Methods: A retrospective and descriptive analysis was conducted based on the medical records of the multiple trauma patients (ISS ≥ 16) transferred to the Grade 3A hospitals outside Sichuan province. The patients were divided into two groups based on the distance to Sichuan province, i.e., Group A (the seismic patients transferred to Chongqing) and Group B (the seismic patients transferred to the other provinces/ municipalities). A comparison was done in aspects of distance of transfer, time from injury to transfer, vital signs, the infection rates (at transfer and on discharge), injury severity and prognostic indices (cure rate, disability rate and mortality). Results: The distance between Chengdu and the other places was at a wide range of 313 - 1653 km, whereas the time from injury to transfer showed no statistical difference between groups (P > 0.05). There were no significant differences between both groups with respects to patient demographics, injury mechanism, time from injury to transfer, vital signs, infection rate and injury severity. The prognostic indices showed no significant difference, except for FIM scores (P < 0.05). Conclusions: The results of the study indicate that the different distance of the transfer of the multiple trauma patients does not aggravate the severity or deteriorate the prognosis, which proves that the medical supportive transfer system is acceptable, effective and worthy of further implementation in China, which may be ascribed to the advanced transportation system and high level of therapeutic capacity of the hospitals. In the meantime, attention should be paid to psychological intervention and functional rehabilitation during the treatment of the transferred seismic patients.
基金supported by National Natural Science Foundation of China(21676065 and 21776053)。
文摘Carbides/carbon composites are emerging as a new kind of binary dielectric systems with good microwave absorption performance.Herein,we obtain a series of tungsten carbide/carbon composites through a simple solvent-free strategy,where the solid mixture of dicyandiamide(DCA)and ammonium metatungstate(AM)is employed as the precursor.Ultrafine cubic WC1-x nanoparticles(3-4 nm)are in situ generated and uniformly dispersed on carbon nanosheets.This configuration overcomes some disadvantages of conventional carbides/carbon composites and is greatly helpful for electromagnetic dissipation.It is found that the weight ratio of DCA to AM can regulate chemical composition of these composites,while less impact on the average size of WC1-x nanoparticles.With the increase in carbon nanosheets,the relative complex permittivity and dielectric loss ability are constantly enhanced through conductive loss and polarization relaxation.The different dielectric properties endow these composites with distinguishable attenuation ability and impedance matching.When DCA/AM weight ratio is 6.0,the optimized composite can produce good microwave absorption performance,whose strongest reflection loss intensity reaches up to-55.6 dB at 17.5 GHz and qualified absorption bandwidth covers 3.6-18.0 GHz by manipulating the thickness from 1.0 to 5.0 mm.Such a performance is superior to many conventional carbides/carbon composites.
基金supported by grants from the National Nonprofit Institute Research Grant (Y2020PT02)the earmarked fund for the modern agroindustry technology research system (CARS-41)+1 种基金Agricultural Science and Technology Innovation Program (ASTIP-IAS04ASTIP-IAS-TS-15)。
文摘Background: Improving the feed efficiency would increase profitability for producers while also reducing the environmental footprint of livestock production. This study was conducted to investigate the relationships among feed efficiency traits and metabolizable efficiency traits in 180 male broilers. Significant loci and genes affecting the metabolizable efficiency traits were explored with an imputation-based genome-wide association study. The traits measured or calculated comprised three growth traits, five feed efficiency related traits, and nine metabolizable efficiency traits.Results: The residual feed intake(RFI) showed moderate to high and positive phenotypic correlations with eight other traits measured, including average daily feed intake(ADFI), dry excreta weight(DEW), gross energy excretion(GEE), crude protein excretion(CPE), metabolizable dry matter(MDM), nitrogen corrected apparent metabolizable energy(AMEn), abdominal fat weight(Ab F), and percentage of abdominal fat(Ab P). Greater correlations were observed between growth traits and the feed conversion ratio(FCR) than RFI. In addition, the RFI, FCR, ADFI, DEW,GEE, CPE, MDM, AMEn, Ab F, and Ab P were lower in low-RFI birds than high-RFI birds(P < 0.01 or P < 0.05), whereas the coefficients of MDM and MCP of low-RFI birds were greater than those of high-RFI birds(P < 0.01). Five narrow QTLs for metabolizable efficiency traits were detected, including one 82.46-kb region for DEW and GEE on Gallus gallus chromosome(GGA) 26, one 120.13-kb region for MDM and AMEn on GGA1, one 691.25-kb region for the coefficients of MDM and AMEn on GGA5, one region for the coefficients of MDM and MCP on GGA2(103.45–103.53 Mb), and one 690.50-kb region for the coefficient of MCP on GGA14. Linkage disequilibrium(LD) analysis indicated that the five regions contained high LD blocks, as well as the genes chromosome 26 C6 orf106 homolog(C26 H6 orf106), LOC396098, SH3 and multiple ankyrin repeat domains 2(SHANK2), ETS homologous factor(EHF), and histamine receptor H3-like(HRH3 L), which are known to be involved in the regulation of neurodevelopment, cell proliferation and differentiation, and food intake.Conclusions: Selection for low RFI significantly decreased chicken feed intake, excreta output, and abdominal fat deposition, and increased nutrient digestibility without changing the weight gain. Five novel QTL regions involved in the control of metabolizable efficiency in chickens were identified. These results, combined through nutritional and genetic approaches, should facilitate novel insights into improving feed efficiency in poultry and other species.
文摘Objective To investigate the effect of target-and-endpoint protocol on the resuscitation of septic patients.Methods This is a retrospective study performed at the Peking Union Medical College Hospital Intensive Care Unit.We enrolled 545 septic patients who needed vasopressors on at least the first day of ICU admission.The general characteristics,blood lactate level,mean arterial pressure(MAP),central venous pressure(CVP)and saturation of central venous oxygen(ScvO2)at admission and 6,24 hours after admission were collected.The parameters at different time points were compared.Lactate clearance rate and in-hospital mortality were analyzed.Results The 6-hour lactate clearance rate was 21.6%(IQR,8.6%-39.0%),and in-hospital mortality was 9.4%.For patients with low CVP values(<8 mm Hg,1 mm Hg=0.133 kPa)at admission,CVP increased significantly at 6 hours after admission(5.4±1.6 mm Hg vs.7.7±2.6 mm Hg,P<0.001).For patients with low MAP(<75 mm Hg)at admission,the MAP values increased significantly at 6 hours(64.2±7.1 mm Hg vs.82.2±13.1 mm Hg,P<0.001).For patients with low ScvO2 value(<70%)at admission,the ScvO2 value increased significantly at 6 hours(61.9%±7.0%vs.71.9%±7.8%,P<0.001).No difference was found between the values at 6 hours and the corresponding values at 24 hours after admission.For patients with high CVP values(≥8 mm Hg)at admission,CVP decreased significantly at 6 hours(11.3±4.0 mm Hg vs.10.3±2.9 mm Hg,P<0.001).For patients with high MAP(≥75 mm Hg)at admission,the MAP values decreased significantly at 6 hours(94.2±13.9 mm Hg vs.89.4±11.4 mm Hg,P<0.001).For patients with high ScvO2 value(≥70%)at admission,the ScvO2 values decreased significantly at 6 hours(76.8%±4.2%vs.72.9%±7.3%,P<0.001).No difference was found between the values at 6 hours and the corresponding values at 24 hours.Conclusions This study suggested that in the resuscitation of sepsis and septic shock patients in the ICU,the target values did not need to be within the“normal range”recommended by early-goal directed therapy.The“target-and-endpoint”protocol,which aimed for personalized goals,deserves more consideration.
基金This work was supported by grants from the National Institute of Dental and Craniofacial Research,National Institutes of Health,Department of Health and Human Services(K99E025915 to C.C.)a Schoenleber Pilot Research Grant(to S.S.)from the University of Pennsylvania School of Dental Medicine,the Guangdong Financial Fund for High-Caliber Hospital Construction,the Postdoctoral Innovative Talents Support Program of China(BX20190380 to B.S.)the General Program of the China Postdoctoral Science Foundation(2019M663986 to B.S.).
文摘Mesenchymal stem cells(MSCs)closely interact with the immune system,and they are known to secrete inflammatory cytokines in response to stress stimuli.The biological function of MSC-derived inflammatory cytokines remains elusive.Here,we reveal that even under physiological conditions,MSCs produce and release a low level of tumor necrosis factor alpha(TNFα),which is unexpectedly required for preserving the self-renewal and differentiation of MSCs via autocrine/paracrine signaling.Furthermore,TNFαcritically maintains MSC function in vivo during bone homeostasis.Mechanistically,we unexpectedly discovered that physiological levels of TNFαsafeguard MSC homeostasis in a receptor-independent manner through mechanical force-driven endocytosis and that endocytosed TNFαbinds to mammalian target of rapamycin(mTOR)complex 2 and restricts mTOR signaling.Importantly,inhibition of mTOR signaling by rapamycin serves as an effective osteoanabolic therapeutic strategy to protect against TNFαdeficiency and mechanical unloading.Collectively,these findings unravel the physiological framework of the dynamic TNFαshuttlebased mTOR equilibrium that governs MSC and bone homeostasis.
基金supported by National Natural Science Foundation of China(No.52277149)the Interdisciplinary Program of Wuhan National High Magnetic Field Center(No.WHMFC202144)Huazhong University of Science and Technology.
文摘Hydrogels are biomaterials with 3D networks of hydrophilic polymers.The generation of hydrogels is turning to the development of hydrogels with the help of enabling technologies.Plasma can tailor the hydrogels’properties through simultaneous physical and chemical actions,resulting in an emerging technology of plasma-activated hydrogels(PAH).PAH can be divided into functional PAH and biological tissue model PAH.This review systematically introduces the plasma sources,plasma etching polymer surface,and plasma cross-linking involved in the fabrication of PAH.The‘diffusion-drift-reaction model’is used to study the microscopic physicochemical interaction between plasma and biological tissue PAH models.Finally,the main achievements of PAH,including wound treatment,sterilization,3D tumor model,etc,and their development trends are discussed.
基金Project supported by the National Natural Science Foundation of China(Grant No.51705459)the China Postdoctoral Science Foundation.
文摘The key to high manoeuvre ability in bird flight lies in the combined morphing of wings and tail.The perching of a wild Haliaeetus Albicilla without running or wing flapping is recorded and investigated using a high-speed digital video.A shape reconstruction method is proposed to describe wing contours and tail contours during perching.The avian airfoil geometries of the Aquila Chrysaetos are extracted from noncontact surface measurements using a ROMBER 3D laser scanner.The wing planform,chord distribution and twist distribution are fitted in convenient analytical expressions to obtain a 3D wing geometry.A three-jointed arm model is proposed to associate with the 3D wing geometry,while a one-joint arm model is proposed to describe the kinematics of tail.Therefore,a 3D bird model is established.The perching sequences of the wild eagle are recaptured and regenerated with the proposed 3D bird model.A quasi-steady aerodynamic model is applied in the aerodynamic predictions,a four-step Adams-Bashforth method is used to calculate the ordinary differential equations,thus a BFGS based optimization method is established to predict the perching motions.
文摘The large dual-channel wide-bodied aircraft has a long range and a high cruise Mach number.Therefore,its aerodynamic design requires a high level ofwind tunnel test refinement.Based on the requirements of aerodynamic design for the future wide-bodied aircraft and the characteristics of high-speed wind tunnel tests,the error theory is introduced to analyze the factors affecting the accuracy of the test data.This study carries out a series of research on the improvement of refined aerodynamic test technology in an FL-26 wind tunnel,including design and optimization of the support system of wide-bodied aircraft,model attitude angle measurement,Mach number control accuracy,measurement and control system stability,test data correction and perfection,high-precision force balance and standard model development.In addition,the effect of the standard specification of the refined aerodynamic test is investigated to improve the data quality.The research findings have been applied in the standard model test and subsequent models of wide-bodied aircraft.The results show that whenMach numbers are less than 0.9,the control accuracy of Mach numbers in the FL-26 wind tunnel is smaller than 0.001 and the measurement error of attack angle is smaller than 0.01°.Therefore,it has the ability to correct the data influenced by factors,such as support/wall interference,model deformation,floating resistance and airflow deflection angle.The repeatability accuracy of the standard model’s comparison test shows that the lift coefficient is less than or equal to 0.0012,the drag coefficient is less than or equal to 0.00004,pitching moment coefficient is less than or equal to 0.0004.The bending resolution of the model’s deformation measurement is less than 0.2 mm,and the tensional deformation is smaller than 0.04°.The revised aerodynamic data and model deformation measurement results have good agreement with that of the ETW wind tunnel.The results demonstrate that the improved technology presented in this paper can significantly enhance the refined aerodynamic test of wide-bodied aircraft.
文摘Objective Focused cardiac ultrasound(FCU)and lung ultrasound(LU)are increasingly being used in critically ill patients.This study aimed to investigate the effect of FCU in combination with LU on these patients and to determine if the timing of ultrasound examination was associated with treatment change.Methods This is a multicenter cross-sectional observational study.Consecutive patients admitted to the intensive care unit(ICU)were screened for enrollment.FCU and LU were performed within the first 24 h,and treatment change was proposed by the performer based on the ultrasound results and other clinical conditions.Results Among the 992 patients included,502 were examined within 6 h of ICU admission(early phase group),and 490 were examined after 6 h of admission(later phase group).The early phase group and the later phase group had similar proportions of treatment change(48.8%vs.49.0%,χ^(2)=0.003,P=0.956).In the multivariable analysis,admission for respiratory failure was an independent variable associated with treatment change,with an odds ratio(OR)of 2.357[95%confidence interval(CI):1.284-4.326,P=0.006];the timing of examination was not associated with treatment change(OR=0.725,95%CI:0.407-1.291,P=0.275).Conclusions FCU in combination with LU,whether performed during the early phase or later phase,had a significant impact on the treatment of critically ill patients.Patients with respiratory failure were more likely to experience treatment change after the ultrasound examination.
基金supported by National Key Research and Development Plan of China(No.2016YFC0401001)。
文摘The corona discharges provide an efficient way to induce precipitation or eliminate fog by increasing ion density in the open air.In this paper,one bipolar corona discharge array(positive and negative high voltage coupled simultaneously)which can generate high densities of positive and negative ions is developed.The comparison between bipolar corona discharge array and unipolar corona discharge array(positive or negative coupled only)indicates that bipolar corona discharge array can generate~3 times higher ion density than unipolar corona discharge array.More charged aerosols are produced through collisions between ions and aerosols.The collision rate between aerosols is increased substantially by the attractive forces between positively and negatively charged aerosols.The deposition of aerosols induced by bipolar discharges is 25.7%higher than that of unipolar discharges at the humidity super-saturation condition.Therefore,the bipolar corona discharge system is a new option for the large scale ion sources used for artificial weather modification.
基金Project supported by the National Natural Science Foundation of China(Grant No.51705459)the Natural Science Foundation of Zhejiang Province,China(Grant No.LY20E050022).
文摘We investigate how the barb of bird feathers is changed along both the rachis and barb.To investigate the microstructures and the mechanical behaviors of barbs,a series of barbs are manually cut from an eagle’s primary feather to observe the cross sections.Aλ-like cross section with a tiny hook is observed at the right feet at each section.Afterwards,a measurement of the setup system is developed to evaluate the leakage ratio of a feather followed by a numerical predicting approach based on the CFD method.It is found that the air leakage increases linearly against the pressure,and the predicted results coincide well with the experimental results.Finally,the influences of leakage of the flight feather on both steady and unsteady aerodynamics are studied.
基金supported by the Key Research Program of the Chinese Academy of Sciences(Grant No.ZDBS-SSW-TLC001)the National Natural Science Foundation(Grant No.11803056).
文摘China’s first Mars exploration mission,Tianwen-1,successfully landed in southern Utopia Planitia on Mars on May 15,2021.This work presents a detailed investigation of the geologic context of the landing area surface for this mission based on orbital remotesensing data.We constructed a geomorphologic map for the Tianwen-1 landing area.Results of our detailed geomorphologic map show several major landforms within the landing area,including rampart craters,mesas,troughs,cones,and ridges.Analysis of materials on the landing area surface indicates that most of the landing area is covered by Martian dust.Transverse aeolian ridges are widely distributed within the landing area,indicating the surface contexts were(and still are)modified by regional winds.In addition,a crater counting analysis indicates the landing area has an absolute model age of~3.3 Ga and that a later resurfacing event occurred at~1.6 Ga.Finally,we outline four formational scenarios to test the formation mechanisms for the geomorphologic features on the landing area surface.The most likely interpretation to explain the existence of the observed surface features can be summarized as follows:A thermal influence may have played an important role in the formation of the surface geomorphologic features;thus,igneous-related processes may have occurred in the landing area.Water ice may also have been involved in the construction of the primordial surface configuration.Subsequent resurfacing events and aeolian processes buried and modified the primordial surface.
基金supported by National Natural Science Foundation of China(Nos.52130701,51977096,52277150,and12005076)the National Key Research and Development Program of China(No.2021YFE0114700)。
文摘Generation of atmospheric pressure homogeneous air plasma in a large gap(>4 mm)is a challenge.In this study,an atmospheric pressure homogeneous air plasma generated in a gap up to 10 mm is reported,which is based on a three-electrode configuration,where a high-voltage(HV)electrode and a middle electrode form a surface dielectric barrier discharge(S-DBD),and together with the ground electrode form the main volume discharge.High-speed photographs confirm that the discharge in the main gap is homogeneous.The gas temperature of the plasma estimated from the N_(2)(C^(3)∏_(u)-B^(3)∏_(g))(Δv=-2)emission is about 320 K,which is close to room temperature.A detailed analysis shows that the discharge ignited between the HV electrode and the middle electrode is serving as an electron source,and the electrons deposited on the dielectric plate are due to the S-DBD along with the applied voltage generating a driving force,which results in a high concentration of seed electrons in the main gap and induces the homogeneous plasma.Further analysis shows that the electric field in the main gap is only about18.45 k V·cm^(-1),which is much lower than the typical breakdown electric field of 30 k V·cm^(-1)for atmospheric pressure air discharge.
文摘Objective This study aimed to determine which parameters in transthoracic echocardiography(TTE)are more likely to be affected when applied in a critical care setting with mechanical ventilation.Methods Ninety mechanically ventilated ICU patients were enrolled into the study group.The control group consisted of 90 patients who underwent interventional therapy.All patients had bedside TTE for parametric measurements including the right ventricular size,septal kinetics and left ventricular ejection fraction(LVEF)by eyeballing(visual assessment),the tricuspid annular plane systolic excursion(TAPSE),mitral annular plane systolic excursion(MAPSE)by M-mode sonography,the right ventricular outflow tract velocity-time integral(RVOT VTI)and left ventricular outflow tract velocity-time integral(LVOT VTI)by pulse-Doppler,the right ventricular fraction of area change(FAC)and left ventricular ejection fraction(LVEF Simpson)by endocardium tracing.We compared the differences in the frequency of optimal image acquisition in assessments of these parameters between the two groups,as well as the differences in acquisition rates of parameter measurements in ventilated ICU patients.Results There were significantly fewer patients in the study group than in the control group who had optimal images acquisitions for parameter assessments with M-mode method,pulse Doppler method and endocardiumtracing method(P<0.05);no significant difference was obsered in the number of patients with optimal images for RV eyeballing and LVEF eyeballing between the two groups.In the study group,significantly fewer optimal images were acquired for FAC than forTAPSE(22.2%vs、72.2%,χ2=45.139,P<0.001)and RVOT VTI(22.2%vs.71.1%,χ2=43.214,P<0.001);there were also fewer optimal images acquired for LVEF Simpson than for MAPSE(37.8%ys.84.4%,χ2=41.236,P<0.001)and LVOT VTI(37.8%vs.85.6%,/=43.455,P<0.001).Conclusions Images acquisition of optimal TTE images tend to be difRcult in mechanically ventilated ICU patients,but eyeballing method for functional evaluation could be an alternative method.For quantitative parameters measurements,M-mode based longitudinal function evaluation and pulse Doppler-based VTI were superior to the endocardium-tracing based parameter assessments.
基金supported by National Natural Science Foundation of China(52175279,51705459)Natural Science Foundation of Zhejiang Province(LY20E050022).
文摘Raptors can change the shape and area of their wings to an exceptional degree in a fast and efficient manner,surpassing other birds,insects,or bats.Some researchers have focused on the functional properties of muscle skeletons,mechanics,and flapping robot design.However,the wing motion of the birds of prey has not been measured quantitatively,and synthetic bionic wings with morphing abilities similar to raptors are far from reality.Therefore,in the current study,a 3D suspension system for holding bird carcasses was designed and fabricated to fasten the wings of Falco Peregrinus with a series of morphing postures.Subsequently,the wing skeleton of the falcon was scanned during extending motions using the computed tomography(CT)approach to obtain three consecutive poses.Subsequently,the skeleton was reconstructed to identify the contribution of the forelimb bones to the extending/folding motions.Inspired by these findings,we propose a simple mechanical model with four bones to form a wing-morphing mechanism using the proposed pose optimisation method.Finally,a bionic wing mechanism was implemented to imitate the motion of the falcon wing—divided into inner and outer wings with folding and twisting motions.The results show that the proposed four-bar mechanism can track bone motion paths with high fidelity.
基金funded by the Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(CIFMS)from the CAMS(No.2021-I2M-1-062)the National Key R&D Program of China,Ministry of Science and Technology of the People’s Republic of China(No.2021YFC2500801)+3 种基金the Beijing Municipal Natural Science Foundation(No.M21019)the CAMS Endowment Fund(No.2021-CAMS-JZ004)the China Medical Board Open Competition Program(No.20-381)the Chinese Medical Information and Big Data Association(CHMIA)Special Fund for Emergency Project.
文摘This cohort study was performed to explore the influence of intensive care unit(ICU)quality on in-hospital mortality of veno-venous(V-V)extracorporeal membrane oxygenation(ECMO)-supported patients in China.The study involved all V-V ECMO-supported patients in 318 of 1700 tertiary hospitals from 2017 to 2019,using data from the National Clinical Improvement System and China National Critical Care Quality Control Center.ICU quality was assessed by quality control indicators and capacity parameters.Among the 2563 V-V ECMO-supported patients in 318 hospitals,a significant correlation was found between ECMO-related complications and prognosis.The reintubation rate within 48 hours after extubation and the total ICU mortality rate were independent risk factors for higher in-hospital mortality of V-V ECMO-supported patients(cutoff:1.5%and 7.0%;95%confidence interval:1.05–1.48 and 1.04–1.45;odds ratios:1.25 and 1.23;P=0.012 and P=0.015,respectively).Meanwhile,the V-V ECMO center volume was a protective factor(cutoff of≥50 cases within the 3-year study period;95%confidence interval:0.57–0.83,odds ratio:0.69,P=0.0001).The subgroup analysis of 864 patients in 11 high-volume centers further strengthened these findings.Thus,ICU quality may play an important role in improving the prognosis of V-V ECMO-supported patients.