Ramsey oscillations typically exhibit an exponential decay envelope due to environmental noise. However,recent experiments have observed nonmonotonic Ramsey fringes characterized by beating patterns, which deviate fro...Ramsey oscillations typically exhibit an exponential decay envelope due to environmental noise. However,recent experiments have observed nonmonotonic Ramsey fringes characterized by beating patterns, which deviate from the standard behavior. These beating patterns have primarily been attributed to charge-noise fluctuations.In this paper, we have experimentally observed Ramsey fringe with beating pattern for transmon qubits, and traced the origin to electric instruments induced flux noise.展开更多
BACKGROUND: Although the use of non-heart beating donors (NHBDs) could bridge the widening gap between organ demand and supply, its application to liver transplantation is limited due to the high incidence of primary ...BACKGROUND: Although the use of non-heart beating donors (NHBDs) could bridge the widening gap between organ demand and supply, its application to liver transplantation is limited due to the high incidence of primary graft loss. Prevention of liver injury in NHBDs will benefit the results of transplantation. This study was conducted to evaluate the protective effects of L-arginine on liver grafts from NHBDs. METHODS: One hundred and four Wistar rats were randomly divided into 7 groups: normal control (n=8) controls 1, 2 and 3 (C-1, C-2, C-3, n=16), and experimental 1, 2 and 3 (E-1, E-2, E-3, n=16). For groups C-1 and E-1, C-2 and E-2, and C-3 and E-3, the warm ischemia time was 0, 30, and 45 minutes, respectively. Liver grafts were flushed with and preserved in 4 degrees C Euro-collins solution containing 1 mmol/L L-arginine for 1 hour in each experimental group. Recipients of each experimental group were injected with L-arginine (10 mg/kg body weight) by tail vein 10 minutes before portal vein reperfusion. Donors and recipients of each experimental control group were treated with normal saline. Then transplantation was performed. At 1, 3, and 24 hours after portal vein reperfusion, blood samples were obtained to determine the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), nitric oxide (NO) and plasma endothelin (ET). At 3 hours after portal vein reperfusion, grafts samples were fixed in 2.5% glutaraldehyde for electron microscopic observation. RESULTS: At I hour after portal vein reperfusion, the levels of NO in groups E-1, E-2, E-3 and C-1, C-2, C-3 were lower, while the levels of plasma ET, serum ALT and AST were higher than those in the normal control group (P<0.05). At 1, 3, and 24 hours, the levels of NO in groups E-1, E-2, E-3 were higher, while the levels of plasma ET, serum ALT and AST were lower than those in the corresponding control groups (C-1, C-2, C-3) (P<0.05). The levels of NO in groups C-2 and C-3 were lower than in group C-1 (P<0.05), and the level of NO in group C-3 was lower than in group C-2 (P<0.05). At 1, 3 and 24 hours, the levels of plasma ET, serum ALT, and AST in groups E-1, E-2, E-3 were lower than those in the corresponding control groups (C-1, C-2, C-3) (P<0.05). The levels of plasma ET, serum ALT, and AST were lower in group C-3 than in groups C-1 and C-2 (P<0.05). Pathological changes in groups E-1, E-2, E-3 were milder than those in the corresponding experimental control groups (C-1, C-2, C-3). CONCLUSIONS: The imbalance between NO and ET plays an important role in the development of ischemia-reperfusion injury of liver grafts from NHBDs. L-arginine can attenuate injury in liver grafts from NHBDs by improving the balance between NO and ET.展开更多
The aim of the present study was to screen cardioactive herbs from Western Ghats of India. The heart beat rate （HBR） and blood flow during systole and diastole were tested in zebrafish embryos. We found that Cynodon...The aim of the present study was to screen cardioactive herbs from Western Ghats of India. The heart beat rate （HBR） and blood flow during systole and diastole were tested in zebrafish embryos. We found that Cynodon dactylon （C. dactylon） induced increases in the HBR in zebrafish embryos with a HBR of （3.968±0.344） beats/ s, which was significantly higher than that caused by betamethosone [（3.770±0.344） beats/s]. The EC50 value of C. dactylon was 3.738 μg/mL. The methanolic extract of Sida acuta （S. acuta） led to decreases in the HBR in zebrafish embryos [（1.877 ±0.079） beats/s], which was greater than that caused by nebivolol （positive control）. The EC50 value of Sida acuta was 1.195 μg/mL. The untreated embryos had a HBR of （2.685±0.160） beats/s at 3 d post fertilization （dpf）. The velocities of blood flow during the cardiac cycle were （2,291.667 ±72.169） μm/s for the control, （4,250± 125.000） μm/s for C. dactylon and （1,083.333±72.169） μm/s for S. acuta. The LC50 values were 32.6 μg/mL for C. dactylon and 20.9 μg/mL for S. acuta. In addition, the extracts exhibited no chemical genetic effects in the drug dosage range tested. In conclusion, we developed an assay that can measure changes in cardiac function in response to herbal small molecules and determine the cardiogenic effects by microvideography.展开更多
The present research of cold-beating formation mainly focused on roller design and manufacture, kinematics, constitutive relation, metal flow law, thermo-mechanical coupling, surface micro-topography and microstructur...The present research of cold-beating formation mainly focused on roller design and manufacture, kinematics, constitutive relation, metal flow law, thermo-mechanical coupling, surface micro-topography and microstructure evolution. However, the research on surface quality and performance of workpieces in the process of cold-beating is rare. Cold-beating simulation experiment of 1020 steel is conducted at room temperature and strain rates ranging from 2000 to 4000 s^-1 base on the law of plastic forming. According to the experimental data, the model of strain hardening of 1020 steel is established, Scanning Electron Microscopy（SEM） is conducted, the mechanism of the work hardening of 1020 steel is clarified by analyzing microstructure variation of 1020 steel. It is found that the strain rate hardening effect of 1020 steel is stronger than the softening effect induced by increasing temperatures, the process of simulation cold-beating cause the grain shape of 1020 steel significant change and microstructure elongate significantly to form a fibrous tis- sue parallel to the direction of deformation, the higher strain rate, the more obvious grain refinement and the more hardening effect. Additionally, the change law of the work hardening rate is investigated, the relationship between dislocation density and strain, the relationship between work hardening rate and dislocation density is obtained. Results show that the change trend of the work hardening rate of 1020 steel is divided into two stages, the work hardening rate decreases dramatically in the first stage and slowly decreases in the second stage, finally tending toward zero. Dislocation density increases with increasing strain and strain rate, work hardening rate decreases with increasing dislocation density. The research results provide the basis for solving the problem of improving the surface quality and performance of workpieces under cold-beating formation of 1020 steel.展开更多
In the pump-controlled motor hydraulic transmission system,when the pressure pulsation frequencies seperately generated by the pump and the motor are close to each other,the hydraulic system will generate a strong pre...In the pump-controlled motor hydraulic transmission system,when the pressure pulsation frequencies seperately generated by the pump and the motor are close to each other,the hydraulic system will generate a strong pressure beat vibration phenomenon,which will seriously affect the smooth running of the hydraulic system.However,the modulated pressure signal also carries information related to the operating state of the hydraulic system,and a accurate extraction of pressure vibration characteristics is the key to obtain the operating state information of the hydraulic system.In order to extract the pressure beat vibration signal component effectively from the multi-component time-varying aliasing pressure signal and reconstruct the time domain characteristics,an extraction method of the pressure beat vibration characteristics of the hydraulic transmission system based on variational mode decomposition(VMD)is proposed.The experimental results show that the VMD method can accurately extract the pressure beat vibration characteristics from the high-pressure oil pressure signal of the hydraulic system,and the extraction effect is preferable to that of the traditional signal processing methods such as empirical mode decomposition(EMD).展开更多
The EAST superconducting tokamak, an advanced steady-state plasma physics experimental device, has been built at the Institute of Plasma Physics, Chinese Academy of Sciences. All the toroidal field magnets and poloida...The EAST superconducting tokamak, an advanced steady-state plasma physics experimental device, has been built at the Institute of Plasma Physics, Chinese Academy of Sciences. All the toroidal field magnets and poloidal field magnets, made of NbTi/Cu cable-in-conduit conductor, are cooled with forced flow supercritical helium at 3.8 K. The cryogenic system of EAST consists of a 2 kW/4 K helium refrigerator and a helium distribution system for the cooling of coils, structures, thermal shields, bus-lines, etc. The high-speed turbo-expander is an important refrigerating component of the EAST cryogenic system. In the turbo-expander, the axial supporting technology is critical for the smooth operation of the rotor bearing system. In this paper, hydrostatic thrust bearings are designed based on the axial load of the turbo-expander. Thereafter, a computational fluid dynamics-based numerical model of the aerostatic thrust bearing is set up to evaluate the bearing performance. Tilting effect on the pressure distribution and bearing load is analyzed for the thrust beating. Bearing load and stiffness are compared with different static supply pressures. The net force from the thrust bearings can be calculated for different combinations of bearing clearance and supply pressure.展开更多
Objective:To evaluate the efficacy and safety of Wenxin Keli for premature beats in structurally normal heart systematically.Methods:Eight databases at home and abroad were searched to collect randomized controlled tr...Objective:To evaluate the efficacy and safety of Wenxin Keli for premature beats in structurally normal heart systematically.Methods:Eight databases at home and abroad were searched to collect randomized controlled trials of Wenxin Keli for premature beats without cardiac diseases.The included literatures were systematically evaluated with Cochrane Handbook 5.1 evaluation criteria and tools,and Meta analysis was performed with software RevMan5.3.Results:A total of 13 randomized controlled trials with 1278 subjects were included.The exprimental group used Wenxin Keli alone while the control group used antiarrhythmic medicine.The Meta analysis results showed that the total effective rate(RR=1.06,95%CI[0.97,1.16],P=0.23)and clinical symptom effective rate(RR=1.16,95%CI[0.94,1.44],P=0.18)of Wenxin Keli on idiopathic premature beats was not significantly different from western medicine group.The subgroup analysis of total effective rate showed that Wenxin Keli had no significant difference with metoprolol(RR=1.04,95%CI[0.95,1.15],P=0.41),bisoprolol(RR=1.32,95%CI[0.85,2.05],P=0.22)and propanone(RR=1.07,95%CI[0.90,1.26],P=0.44).ECG changes showed that the PR intervals(MD=-12.57,95%CI[-16.15,-8.99],P<0.00001)and QTc intervals(MD=-8.09,95%CI[-15.52,-0.65],P=0.03)in the western medicine group were prolonged significantly more than those of Wenxin Keli.In terms of safety,the incidence of adverse reactions of Wenxin Keli was significantly less than that of western medicine group(RR=0.32,95%CI[0.19,0.54],P<0.0001).Conclusion:The efficacy of Wenxin Keli in the treatment of premature beats with structurally normal heart is accurate,and there are no serious adverse reactions.However,because of the low quality of the included papers,which affected the reliability of the conclusions,high-quality clinical research is needed to further demonstrate.展开更多
Diagnostic techniques of CEOF, power spectrum and bandpass filter wave are applied in this paper to analyze the seasonal northward beating of the northern subtropical high using day to day geopotential fields of 2.5 &...Diagnostic techniques of CEOF, power spectrum and bandpass filter wave are applied in this paper to analyze the seasonal northward beating of the northern subtropical high using day to day geopotential fields of 2.5 ×2.5 at 500 hPa May through July in 1988 and 1991. It is concluded that it is globally observed that the subtropical high has northward beats that propagate westward; the source of beating mainly lies in the region of Arabian Sea and central Pacific and the sink in eastern Pacific; the seasonal beating is dominated by effects of the disturbance field; low frequency oscillation plays a key role in the beating and the westward propagation so that the difference in the latter in individual years is caused by the varying source of disturbance and the low frequency waves it excites.展开更多
We experimentally study the controllable generation of a beating signal using stored light pulses based on electromagnetically induced transparency(EIT) in a solid medium. The beating signal relies on an asymmetric pr...We experimentally study the controllable generation of a beating signal using stored light pulses based on electromagnetically induced transparency(EIT) in a solid medium. The beating signal relies on an asymmetric procedure of light storage and retrieval. After storing the probe pulse into the spin coherence under the EIT condition, two-color control fields with opposite detunings instead of the initial control field are used to scatter the stored spin coherence. The controllable beating signal is generated due to alternative constructive and destructive interferences in the retrieved signal intensities. The beating of the two-color control fields is mapped into the beating of weak probe fields by using atomic spin coherence. This beating signal will be important in precise atomic spectroscopy and fast quantum limited measurements.展开更多
In this paper,what causes the setting-on place of woven fabrics without adopting tension compensation is explained by means of experimental methods.Owing to that the main shaft speed and the beating speed of reed can ...In this paper,what causes the setting-on place of woven fabrics without adopting tension compensation is explained by means of experimental methods.Owing to that the main shaft speed and the beating speed of reed can not attain the normal values at setting-on,the warp tension and the beating force of the reed can neither reach the normal level.Therefore,the relative slippage movement of the weft against the warp during beating will be less,while the common movement of the weft together with the warp will be bigger than those at nor-mal running.As a result,the setting-on place is展开更多
In this paper we present a new projective synchronization scheme, where two chaotic （hyperchaotic） discrete-time systems synchronize for any arbitrary scaling matrix. Specifically, each drive system state synchroniz...In this paper we present a new projective synchronization scheme, where two chaotic （hyperchaotic） discrete-time systems synchronize for any arbitrary scaling matrix. Specifically, each drive system state synchronizes with a linear combination of response system states. The proposed observer-based approach presents some useful features： i） it enables exact synchronization to be achieved in finite time （i.e., dead-beat synchronization）; ii） it exploits a scalar synchronizing signal; iii） it can be applied to a wide class of discrete-time chaotic （hyperchaotic） systems; iv） it includes, as a particular case, most of the synchronization types defined so far. An example is reported, which shows in detail that exact synchronization is effectively achieved in finite time, using a scalar synchronizing signal only, for any arbitrary scaling matrix.展开更多
In this paper, the intrinsic behavior of rotating Euler Benoulli flexible shafts was studied due to coupled bending and torsional vibrations. The equations of motion of the shaft with unbalanced eccentricity and visc...In this paper, the intrinsic behavior of rotating Euler Benoulli flexible shafts was studied due to coupled bending and torsional vibrations. The equations of motion of the shaft with unbalanced eccentricity and viscous material damping were derived by the Hamilton principle. The numerical solution was obtained using the perturbation approach and mode assuming method. The influences of the coupled vibrations between the bending and torsion, the rotating speed, material damping and the slenderness ratio of the shaft were analyzed. It is clearly shown that the beating phenomena can occur when the interaction of torsion and flexure is considered.展开更多
We study the colour-locked twin-noisy-field correlation effects in the fifth-order nonlinear susceptibility of ultrafast polarization beats in a cascade four-level system. More importantly, the fifth-order phase-sensi...We study the colour-locked twin-noisy-field correlation effects in the fifth-order nonlinear susceptibility of ultrafast polarization beats in a cascade four-level system. More importantly, the fifth-order phase-sensitive heterodyne detection of ultrafast polarization beats has been exploited. The fifth-order nonlinear optical response can be controlled and modified through the colour-locked correlation of twin noisy fields. Thus, this method with the phase dispersion information is a good way to measure the real and imaginary parts of the fifth-order nonlinear susceptibility.展开更多
Classical beat phenomenon has been observed in most combined systems. The focus of this paper is to provide a better understanding of this phenomenon in an offshore pile-supported pipeline system. The beat phenomeon i...Classical beat phenomenon has been observed in most combined systems. The focus of this paper is to provide a better understanding of this phenomenon in an offshore pile-supported pipeline system. The beat phenomeon is caused by the coupling movement of the pipeline and its vertical pile support under certain conditions. It can induce excessive vibration and cause fatigue failure at pipe elbow. However, in some circumstances it does not exist. Numerical results in both frequency and time domains are presented to elucidate this phenomenon in a combined pipeline system. The conclusions of this paper could give constructive guidance to future design of simply supported pipeline systems.展开更多
Objective: To study the outcome of normothermic beating heart pulmonary thromboendarterectomy (PTE) performed in patients with chronic pulmonary thromboembolism. Methodology: A retrospective analysis of 15 patients wh...Objective: To study the outcome of normothermic beating heart pulmonary thromboendarterectomy (PTE) performed in patients with chronic pulmonary thromboembolism. Methodology: A retrospective analysis of 15 patients who underwent PTE under normothermic beating heart cardio-pulmonary bypass from July 2009 to September 2018 was done. The patients were followed up with clinical assessment, transthoracic echocardiography and computerized tomographicangiography (CTA) for 1 month to 82 months. Results: Data were analysed for 15 consecutive patients. Mean age of the patients was 35.28 years and 10 patients were male. Pre-operatively 6 (40%) patients presented with New York Heart Association (NYHA) class II dyspnoea on exertion symptomatology, 7 (47%) were in NHYA class III, and 2 (13%) were in NYHA class IV. The preoperative and postoperative mean pulmonary artery pressures (mPAP) (mmHg) were 36.50 ± 11.3 and 20.21 ± 7.19, the systolic PAPs (mmHg) were 73.35 ± 14.12 and 35.21 ± 7.89 and the diastolic PAPs (mmHg) were 19.28 ± 8.60 and 12.85 ± 7.26 respectively. 2 (13%) patients had Jamieson’s type I and 12 (87%) had Jamieson type II disease. One patient (7%) expired on 9th postoperative day. All the patients had improved pulmonary gas exchange and did not require oxygen supplementation from 5th postoperative day;symptoms improved to NYHA class I & II in 12 (80%) & 3 (20%) of patients respectively. There was no reperfusion pulmonary edema or any neurologic complications. Postoperative echocardiogram showed improved right ventricular function and Computerised Tomographic Angiogram showed completeness of the procedure. Conclusion: Pulmonary thromboendarterectomy under normothermic beating heart cardiopulmonary bypass has good immediate postoperative results with significant progressive improvement in hemodynamics and quality of life during the course of follow-up. The results were not only comparable to those of the procedure done under deep hypothermic circulatory arrest by other centres but also without its associated adverse events. This technique requires more expertise but gives equivalent good results in immediate and short- to mid-term follow-up with less morbidity than the standard procedure, but it requires long-term follow-up to substantiate the evidence.展开更多
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With the experience of over 250 beating hear operations since Feb 1995 westarted minimally invasive revascularization of the LAD(MIDCAB).SinceFeb.1996 we operated upon 182 patients with this procedure Since June1996 w...With the experience of over 250 beating hear operations since Feb 1995 westarted minimally invasive revascularization of the LAD(MIDCAB).SinceFeb.1996 we operated upon 182 patients with this procedure Since June1996 we treated 40 patients with multivessel discase with a Hybridproccdurc(PTCA plus MIDCAB)The age of the patients ranged between 68 and 79 years.29 patients waremaic.28 patiens suffered from a double vessel discase.12 patients fromtriple vessel discase.The left ventricular ejeetion fraction was loss then 40%in 8 cases 2 patients underwent a reoperativc procedure.Further risk factorswere COLD(n=9).recent MI(n=6),renal insufliciency(n=13).Diabeiesinellitus(n-12).The left mammary was prepared in the usual manner.As access wechese a partial inferior sternotomy(n=4)or a lateral minithoracotomy(n=36).The anastomosis was performed on the beating heart.In all patients we conneeted the LIMA to the LAD.All patients survived andcould be discharged on the 6th postoperative day(mean).In two patients arevision due to bleeding became necessary.Two patients reccived a bloodtransfusions.Postoperatively 15 patients reccived a PTCA of the RCX.4 astentimplantation to the Rex.16 a PTCA of the RCA.5 a stentimplantationto the RCA and 3 patients a PTCA of a D1.3 patients developed a falscaneurysm after the cathcter intervention.By performing the nunimally invasive proeedure the trauma caused bycxtracorporeal circulation can be avoided.Through the combination withPTCA a less invasive therapy of coronary multivessel discase becomespossible in select patients.Postoperative complications and hospital stay canbe teduced.展开更多
The Central Statistical Agency （CSA） of Ethiopia included some questions in its 2005 Demographic and Health Survey （DHS） questionnaire, asking for the opinion of men and women if wives beaten by husbands is justif...The Central Statistical Agency （CSA） of Ethiopia included some questions in its 2005 Demographic and Health Survey （DHS） questionnaire, asking for the opinion of men and women if wives beaten by husbands is justified if wives commit some mistakes while they are undertaking their day to day family responsibilities and other personal functions. The sample size was about 14,000 women in the reproductive and productive ages of 15-49 and about 6,000 men in the age brackets of 15-59. The reasons for wife beating by husbands are examined against some selected independent background variables of the sampled men and women respondents, while the dependent variables are the responses to questions of wife beating. With respect to the analytical model, the author decided to focus on some descriptive statistics, such as frequency distributions tables, proportions, comparative analysis, and application of chi-squares （Xz） techniques to examine the variations in the responses of women and men amongst the independent backgrounds.展开更多
Objective: Acute kidney disease develops 16% - 30% of patients with preoperative impaired renal functions. Our aim of this study was to compare postoperative renal outcomes using two open heart surgery techniques, on-...Objective: Acute kidney disease develops 16% - 30% of patients with preoperative impaired renal functions. Our aim of this study was to compare postoperative renal outcomes using two open heart surgery techniques, on-pump beating heart (OPBH) and conventional on-pump (COP), in patients who have preoperative low glomerular filtration rate (eGFR) as an indicator of creatinine clearance. Methods: From 2004 to 2015, 341 patients with preoperative creatinine clearance were lower than 90 ml/min/1.73m2 were selected for this study. On-Pump beating heart was performed in 111 patients (Group I). Conventional on-pump technique was used in 200 patients. In the remaining patients, we measured postoperative Tumor Necrosis Factor Alpha (TNF-alpha), cardiac troponin I (cTn-I), Brain natriuretic peptid (NT-Pro- BNP), creati-nine (Cr), blood urea nitrogen (BUN) and postoperative eGFR daily until day four after surgery. Results: There were no differences in baseline levels of TNF-alpha, NT-Pro-BNP, BUN, cTn-I, Cr levels between the groups. Cardiopulmonary bypass (CPB) time were much longer and cumulative inotrope use was significantly higher in patients underwent COP (P Conclusion: Our study showed that on-pump beating heart CABG technique provides a morbidity benefit and is associated with a lower risk of peroperative LOS in patients with mild renal disfunction. Our study results suggest that OPBH is superior to the COP in terms of postoperative renal injury and cardiac mediators.展开更多
More than any other time of the year,everyone is shopping and nobody wants to overpay because they missed out on a coupon or promo code.Customers have found the easiest way to save is by downloading a smartphone app.B...More than any other time of the year,everyone is shopping and nobody wants to overpay because they missed out on a coupon or promo code.Customers have found the easiest way to save is by downloading a smartphone app.But after the transaction is completed...they hit the delete button.This dance doesn’t play out only during the holidays,though.Savvy consumers do this all year long-leaving brands and retailers to wonder how展开更多
文摘Ramsey oscillations typically exhibit an exponential decay envelope due to environmental noise. However,recent experiments have observed nonmonotonic Ramsey fringes characterized by beating patterns, which deviate from the standard behavior. These beating patterns have primarily been attributed to charge-noise fluctuations.In this paper, we have experimentally observed Ramsey fringe with beating pattern for transmon qubits, and traced the origin to electric instruments induced flux noise.
基金a grant from the Science & Technology Development Foundation of Guangdong Health Bureau(No.2006345).
文摘BACKGROUND: Although the use of non-heart beating donors (NHBDs) could bridge the widening gap between organ demand and supply, its application to liver transplantation is limited due to the high incidence of primary graft loss. Prevention of liver injury in NHBDs will benefit the results of transplantation. This study was conducted to evaluate the protective effects of L-arginine on liver grafts from NHBDs. METHODS: One hundred and four Wistar rats were randomly divided into 7 groups: normal control (n=8) controls 1, 2 and 3 (C-1, C-2, C-3, n=16), and experimental 1, 2 and 3 (E-1, E-2, E-3, n=16). For groups C-1 and E-1, C-2 and E-2, and C-3 and E-3, the warm ischemia time was 0, 30, and 45 minutes, respectively. Liver grafts were flushed with and preserved in 4 degrees C Euro-collins solution containing 1 mmol/L L-arginine for 1 hour in each experimental group. Recipients of each experimental group were injected with L-arginine (10 mg/kg body weight) by tail vein 10 minutes before portal vein reperfusion. Donors and recipients of each experimental control group were treated with normal saline. Then transplantation was performed. At 1, 3, and 24 hours after portal vein reperfusion, blood samples were obtained to determine the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), nitric oxide (NO) and plasma endothelin (ET). At 3 hours after portal vein reperfusion, grafts samples were fixed in 2.5% glutaraldehyde for electron microscopic observation. RESULTS: At I hour after portal vein reperfusion, the levels of NO in groups E-1, E-2, E-3 and C-1, C-2, C-3 were lower, while the levels of plasma ET, serum ALT and AST were higher than those in the normal control group (P<0.05). At 1, 3, and 24 hours, the levels of NO in groups E-1, E-2, E-3 were higher, while the levels of plasma ET, serum ALT and AST were lower than those in the corresponding control groups (C-1, C-2, C-3) (P<0.05). The levels of NO in groups C-2 and C-3 were lower than in group C-1 (P<0.05), and the level of NO in group C-3 was lower than in group C-2 (P<0.05). At 1, 3 and 24 hours, the levels of plasma ET, serum ALT, and AST in groups E-1, E-2, E-3 were lower than those in the corresponding control groups (C-1, C-2, C-3) (P<0.05). The levels of plasma ET, serum ALT, and AST were lower in group C-3 than in groups C-1 and C-2 (P<0.05). Pathological changes in groups E-1, E-2, E-3 were milder than those in the corresponding experimental control groups (C-1, C-2, C-3). CONCLUSIONS: The imbalance between NO and ET plays an important role in the development of ischemia-reperfusion injury of liver grafts from NHBDs. L-arginine can attenuate injury in liver grafts from NHBDs by improving the balance between NO and ET.
文摘The aim of the present study was to screen cardioactive herbs from Western Ghats of India. The heart beat rate （HBR） and blood flow during systole and diastole were tested in zebrafish embryos. We found that Cynodon dactylon （C. dactylon） induced increases in the HBR in zebrafish embryos with a HBR of （3.968±0.344） beats/ s, which was significantly higher than that caused by betamethosone [（3.770±0.344） beats/s]. The EC50 value of C. dactylon was 3.738 μg/mL. The methanolic extract of Sida acuta （S. acuta） led to decreases in the HBR in zebrafish embryos [（1.877 ±0.079） beats/s], which was greater than that caused by nebivolol （positive control）. The EC50 value of Sida acuta was 1.195 μg/mL. The untreated embryos had a HBR of （2.685±0.160） beats/s at 3 d post fertilization （dpf）. The velocities of blood flow during the cardiac cycle were （2,291.667 ±72.169） μm/s for the control, （4,250± 125.000） μm/s for C. dactylon and （1,083.333±72.169） μm/s for S. acuta. The LC50 values were 32.6 μg/mL for C. dactylon and 20.9 μg/mL for S. acuta. In addition, the extracts exhibited no chemical genetic effects in the drug dosage range tested. In conclusion, we developed an assay that can measure changes in cardiac function in response to herbal small molecules and determine the cardiogenic effects by microvideography.
基金Supported by National Natural Science Foundation of China(Grant Nos.551475146,51475366,51075124)
文摘The present research of cold-beating formation mainly focused on roller design and manufacture, kinematics, constitutive relation, metal flow law, thermo-mechanical coupling, surface micro-topography and microstructure evolution. However, the research on surface quality and performance of workpieces in the process of cold-beating is rare. Cold-beating simulation experiment of 1020 steel is conducted at room temperature and strain rates ranging from 2000 to 4000 s^-1 base on the law of plastic forming. According to the experimental data, the model of strain hardening of 1020 steel is established, Scanning Electron Microscopy（SEM） is conducted, the mechanism of the work hardening of 1020 steel is clarified by analyzing microstructure variation of 1020 steel. It is found that the strain rate hardening effect of 1020 steel is stronger than the softening effect induced by increasing temperatures, the process of simulation cold-beating cause the grain shape of 1020 steel significant change and microstructure elongate significantly to form a fibrous tis- sue parallel to the direction of deformation, the higher strain rate, the more obvious grain refinement and the more hardening effect. Additionally, the change law of the work hardening rate is investigated, the relationship between dislocation density and strain, the relationship between work hardening rate and dislocation density is obtained. Results show that the change trend of the work hardening rate of 1020 steel is divided into two stages, the work hardening rate decreases dramatically in the first stage and slowly decreases in the second stage, finally tending toward zero. Dislocation density increases with increasing strain and strain rate, work hardening rate decreases with increasing dislocation density. The research results provide the basis for solving the problem of improving the surface quality and performance of workpieces under cold-beating formation of 1020 steel.
基金National Natural Science Foundation of China(No.51675399)。
文摘In the pump-controlled motor hydraulic transmission system,when the pressure pulsation frequencies seperately generated by the pump and the motor are close to each other,the hydraulic system will generate a strong pressure beat vibration phenomenon,which will seriously affect the smooth running of the hydraulic system.However,the modulated pressure signal also carries information related to the operating state of the hydraulic system,and a accurate extraction of pressure vibration characteristics is the key to obtain the operating state information of the hydraulic system.In order to extract the pressure beat vibration signal component effectively from the multi-component time-varying aliasing pressure signal and reconstruct the time domain characteristics,an extraction method of the pressure beat vibration characteristics of the hydraulic transmission system based on variational mode decomposition(VMD)is proposed.The experimental results show that the VMD method can accurately extract the pressure beat vibration characteristics from the high-pressure oil pressure signal of the hydraulic system,and the extraction effect is preferable to that of the traditional signal processing methods such as empirical mode decomposition(EMD).
基金supported by National Natural Science Foundation of China(Nos.51406157,51506209)partially supported by the China Postdoctoral Science Foundation(No.2014M552438)
文摘The EAST superconducting tokamak, an advanced steady-state plasma physics experimental device, has been built at the Institute of Plasma Physics, Chinese Academy of Sciences. All the toroidal field magnets and poloidal field magnets, made of NbTi/Cu cable-in-conduit conductor, are cooled with forced flow supercritical helium at 3.8 K. The cryogenic system of EAST consists of a 2 kW/4 K helium refrigerator and a helium distribution system for the cooling of coils, structures, thermal shields, bus-lines, etc. The high-speed turbo-expander is an important refrigerating component of the EAST cryogenic system. In the turbo-expander, the axial supporting technology is critical for the smooth operation of the rotor bearing system. In this paper, hydrostatic thrust bearings are designed based on the axial load of the turbo-expander. Thereafter, a computational fluid dynamics-based numerical model of the aerostatic thrust bearing is set up to evaluate the bearing performance. Tilting effect on the pressure distribution and bearing load is analyzed for the thrust beating. Bearing load and stiffness are compared with different static supply pressures. The net force from the thrust bearings can be calculated for different combinations of bearing clearance and supply pressure.
基金National Natural Science Foundation of China(No.81774128)National key Research and development program(No.2019YFC1708404)。
文摘Objective:To evaluate the efficacy and safety of Wenxin Keli for premature beats in structurally normal heart systematically.Methods:Eight databases at home and abroad were searched to collect randomized controlled trials of Wenxin Keli for premature beats without cardiac diseases.The included literatures were systematically evaluated with Cochrane Handbook 5.1 evaluation criteria and tools,and Meta analysis was performed with software RevMan5.3.Results:A total of 13 randomized controlled trials with 1278 subjects were included.The exprimental group used Wenxin Keli alone while the control group used antiarrhythmic medicine.The Meta analysis results showed that the total effective rate(RR=1.06,95%CI[0.97,1.16],P=0.23)and clinical symptom effective rate(RR=1.16,95%CI[0.94,1.44],P=0.18)of Wenxin Keli on idiopathic premature beats was not significantly different from western medicine group.The subgroup analysis of total effective rate showed that Wenxin Keli had no significant difference with metoprolol(RR=1.04,95%CI[0.95,1.15],P=0.41),bisoprolol(RR=1.32,95%CI[0.85,2.05],P=0.22)and propanone(RR=1.07,95%CI[0.90,1.26],P=0.44).ECG changes showed that the PR intervals(MD=-12.57,95%CI[-16.15,-8.99],P<0.00001)and QTc intervals(MD=-8.09,95%CI[-15.52,-0.65],P=0.03)in the western medicine group were prolonged significantly more than those of Wenxin Keli.In terms of safety,the incidence of adverse reactions of Wenxin Keli was significantly less than that of western medicine group(RR=0.32,95%CI[0.19,0.54],P<0.0001).Conclusion:The efficacy of Wenxin Keli in the treatment of premature beats with structurally normal heart is accurate,and there are no serious adverse reactions.However,because of the low quality of the included papers,which affected the reliability of the conclusions,high-quality clinical research is needed to further demonstrate.
文摘Diagnostic techniques of CEOF, power spectrum and bandpass filter wave are applied in this paper to analyze the seasonal northward beating of the northern subtropical high using day to day geopotential fields of 2.5 ×2.5 at 500 hPa May through July in 1988 and 1991. It is concluded that it is globally observed that the subtropical high has northward beats that propagate westward; the source of beating mainly lies in the region of Arabian Sea and central Pacific and the sink in eastern Pacific; the seasonal beating is dominated by effects of the disturbance field; low frequency oscillation plays a key role in the beating and the westward propagation so that the difference in the latter in individual years is caused by the varying source of disturbance and the low frequency waves it excites.
基金Project supported by the National Basic Research Program of China （Grant No. 201 ICB921603）, the National Natural Science Foundation of China （Grant Nos. 11374126, 10904048, 11074097, 11004079, 11004080, and 11247201）, the China Postdoctoral Science Foundation （Grant Nos. 2011M500924 and 2013T60317）. and the National Fund for Fosterin~ Talents of Basic Science （Grant No. J I 103202）.
文摘We experimentally study the controllable generation of a beating signal using stored light pulses based on electromagnetically induced transparency(EIT) in a solid medium. The beating signal relies on an asymmetric procedure of light storage and retrieval. After storing the probe pulse into the spin coherence under the EIT condition, two-color control fields with opposite detunings instead of the initial control field are used to scatter the stored spin coherence. The controllable beating signal is generated due to alternative constructive and destructive interferences in the retrieved signal intensities. The beating of the two-color control fields is mapped into the beating of weak probe fields by using atomic spin coherence. This beating signal will be important in precise atomic spectroscopy and fast quantum limited measurements.
文摘In this paper,what causes the setting-on place of woven fabrics without adopting tension compensation is explained by means of experimental methods.Owing to that the main shaft speed and the beating speed of reed can not attain the normal values at setting-on,the warp tension and the beating force of the reed can neither reach the normal level.Therefore,the relative slippage movement of the weft against the warp during beating will be less,while the common movement of the weft together with the warp will be bigger than those at nor-mal running.As a result,the setting-on place is
文摘In this paper we present a new projective synchronization scheme, where two chaotic （hyperchaotic） discrete-time systems synchronize for any arbitrary scaling matrix. Specifically, each drive system state synchronizes with a linear combination of response system states. The proposed observer-based approach presents some useful features： i） it enables exact synchronization to be achieved in finite time （i.e., dead-beat synchronization）; ii） it exploits a scalar synchronizing signal; iii） it can be applied to a wide class of discrete-time chaotic （hyperchaotic） systems; iv） it includes, as a particular case, most of the synchronization types defined so far. An example is reported, which shows in detail that exact synchronization is effectively achieved in finite time, using a scalar synchronizing signal only, for any arbitrary scaling matrix.
文摘In this paper, the intrinsic behavior of rotating Euler Benoulli flexible shafts was studied due to coupled bending and torsional vibrations. The equations of motion of the shaft with unbalanced eccentricity and viscous material damping were derived by the Hamilton principle. The numerical solution was obtained using the perturbation approach and mode assuming method. The influences of the coupled vibrations between the bending and torsion, the rotating speed, material damping and the slenderness ratio of the shaft were analyzed. It is clearly shown that the beating phenomena can occur when the interaction of torsion and flexure is considered.
基金Project supported by the National Natural Science Foundation of China(Grant Nos60308002and60678005)the Foundation for the Author of National Excellent Doctoral Dissertation of China(Grant No200339)+2 种基金the Foundation for Key Program of Ministry of Education,China(Grant No105156)the Fok Ying-Tong Education Foundation for Young Teachers in the Higher Education Institutions of China(Grant No101061)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No20050698017)
文摘We study the colour-locked twin-noisy-field correlation effects in the fifth-order nonlinear susceptibility of ultrafast polarization beats in a cascade four-level system. More importantly, the fifth-order phase-sensitive heterodyne detection of ultrafast polarization beats has been exploited. The fifth-order nonlinear optical response can be controlled and modified through the colour-locked correlation of twin noisy fields. Thus, this method with the phase dispersion information is a good way to measure the real and imaginary parts of the fifth-order nonlinear susceptibility.
文摘Classical beat phenomenon has been observed in most combined systems. The focus of this paper is to provide a better understanding of this phenomenon in an offshore pile-supported pipeline system. The beat phenomeon is caused by the coupling movement of the pipeline and its vertical pile support under certain conditions. It can induce excessive vibration and cause fatigue failure at pipe elbow. However, in some circumstances it does not exist. Numerical results in both frequency and time domains are presented to elucidate this phenomenon in a combined pipeline system. The conclusions of this paper could give constructive guidance to future design of simply supported pipeline systems.
文摘Objective: To study the outcome of normothermic beating heart pulmonary thromboendarterectomy (PTE) performed in patients with chronic pulmonary thromboembolism. Methodology: A retrospective analysis of 15 patients who underwent PTE under normothermic beating heart cardio-pulmonary bypass from July 2009 to September 2018 was done. The patients were followed up with clinical assessment, transthoracic echocardiography and computerized tomographicangiography (CTA) for 1 month to 82 months. Results: Data were analysed for 15 consecutive patients. Mean age of the patients was 35.28 years and 10 patients were male. Pre-operatively 6 (40%) patients presented with New York Heart Association (NYHA) class II dyspnoea on exertion symptomatology, 7 (47%) were in NHYA class III, and 2 (13%) were in NYHA class IV. The preoperative and postoperative mean pulmonary artery pressures (mPAP) (mmHg) were 36.50 ± 11.3 and 20.21 ± 7.19, the systolic PAPs (mmHg) were 73.35 ± 14.12 and 35.21 ± 7.89 and the diastolic PAPs (mmHg) were 19.28 ± 8.60 and 12.85 ± 7.26 respectively. 2 (13%) patients had Jamieson’s type I and 12 (87%) had Jamieson type II disease. One patient (7%) expired on 9th postoperative day. All the patients had improved pulmonary gas exchange and did not require oxygen supplementation from 5th postoperative day;symptoms improved to NYHA class I & II in 12 (80%) & 3 (20%) of patients respectively. There was no reperfusion pulmonary edema or any neurologic complications. Postoperative echocardiogram showed improved right ventricular function and Computerised Tomographic Angiogram showed completeness of the procedure. Conclusion: Pulmonary thromboendarterectomy under normothermic beating heart cardiopulmonary bypass has good immediate postoperative results with significant progressive improvement in hemodynamics and quality of life during the course of follow-up. The results were not only comparable to those of the procedure done under deep hypothermic circulatory arrest by other centres but also without its associated adverse events. This technique requires more expertise but gives equivalent good results in immediate and short- to mid-term follow-up with less morbidity than the standard procedure, but it requires long-term follow-up to substantiate the evidence.
文摘ZTE Corporation appeared at Expo Comm China2004 with a range of world-leading solutions andapplications stretching across the entiretechnology spectrum-from mobile and NGNrequirements to videoconferencing and
文摘With the experience of over 250 beating hear operations since Feb 1995 westarted minimally invasive revascularization of the LAD(MIDCAB).SinceFeb.1996 we operated upon 182 patients with this procedure Since June1996 we treated 40 patients with multivessel discase with a Hybridproccdurc(PTCA plus MIDCAB)The age of the patients ranged between 68 and 79 years.29 patients waremaic.28 patiens suffered from a double vessel discase.12 patients fromtriple vessel discase.The left ventricular ejeetion fraction was loss then 40%in 8 cases 2 patients underwent a reoperativc procedure.Further risk factorswere COLD(n=9).recent MI(n=6),renal insufliciency(n=13).Diabeiesinellitus(n-12).The left mammary was prepared in the usual manner.As access wechese a partial inferior sternotomy(n=4)or a lateral minithoracotomy(n=36).The anastomosis was performed on the beating heart.In all patients we conneeted the LIMA to the LAD.All patients survived andcould be discharged on the 6th postoperative day(mean).In two patients arevision due to bleeding became necessary.Two patients reccived a bloodtransfusions.Postoperatively 15 patients reccived a PTCA of the RCX.4 astentimplantation to the Rex.16 a PTCA of the RCA.5 a stentimplantationto the RCA and 3 patients a PTCA of a D1.3 patients developed a falscaneurysm after the cathcter intervention.By performing the nunimally invasive proeedure the trauma caused bycxtracorporeal circulation can be avoided.Through the combination withPTCA a less invasive therapy of coronary multivessel discase becomespossible in select patients.Postoperative complications and hospital stay canbe teduced.
文摘The Central Statistical Agency （CSA） of Ethiopia included some questions in its 2005 Demographic and Health Survey （DHS） questionnaire, asking for the opinion of men and women if wives beaten by husbands is justified if wives commit some mistakes while they are undertaking their day to day family responsibilities and other personal functions. The sample size was about 14,000 women in the reproductive and productive ages of 15-49 and about 6,000 men in the age brackets of 15-59. The reasons for wife beating by husbands are examined against some selected independent background variables of the sampled men and women respondents, while the dependent variables are the responses to questions of wife beating. With respect to the analytical model, the author decided to focus on some descriptive statistics, such as frequency distributions tables, proportions, comparative analysis, and application of chi-squares （Xz） techniques to examine the variations in the responses of women and men amongst the independent backgrounds.
文摘Objective: Acute kidney disease develops 16% - 30% of patients with preoperative impaired renal functions. Our aim of this study was to compare postoperative renal outcomes using two open heart surgery techniques, on-pump beating heart (OPBH) and conventional on-pump (COP), in patients who have preoperative low glomerular filtration rate (eGFR) as an indicator of creatinine clearance. Methods: From 2004 to 2015, 341 patients with preoperative creatinine clearance were lower than 90 ml/min/1.73m2 were selected for this study. On-Pump beating heart was performed in 111 patients (Group I). Conventional on-pump technique was used in 200 patients. In the remaining patients, we measured postoperative Tumor Necrosis Factor Alpha (TNF-alpha), cardiac troponin I (cTn-I), Brain natriuretic peptid (NT-Pro- BNP), creati-nine (Cr), blood urea nitrogen (BUN) and postoperative eGFR daily until day four after surgery. Results: There were no differences in baseline levels of TNF-alpha, NT-Pro-BNP, BUN, cTn-I, Cr levels between the groups. Cardiopulmonary bypass (CPB) time were much longer and cumulative inotrope use was significantly higher in patients underwent COP (P Conclusion: Our study showed that on-pump beating heart CABG technique provides a morbidity benefit and is associated with a lower risk of peroperative LOS in patients with mild renal disfunction. Our study results suggest that OPBH is superior to the COP in terms of postoperative renal injury and cardiac mediators.
文摘More than any other time of the year,everyone is shopping and nobody wants to overpay because they missed out on a coupon or promo code.Customers have found the easiest way to save is by downloading a smartphone app.But after the transaction is completed...they hit the delete button.This dance doesn’t play out only during the holidays,though.Savvy consumers do this all year long-leaving brands and retailers to wonder how
