Comparison between mainstream (Capnostat 5) and a low-flow sidestream capnometer (Capnostream) in mechanically ventilated,sevoflurane-anesthetized rabbits using a Bain coaxial delivery system     

《Veterinary anaesthesia and analgesia》2023,50(1):81-90

ObjectiveTo evaluate agreement between end-tidal carbon dioxide (Pe′CO₂) and PaCO₂ with sidestream and mainstream capnometers in mechanically ventilated anesthetized rabbits, with two ventilatory strategies.Study designProspective experimental study.AnimalsA total of 10 New Zealand White rabbits weighing 3.6 ± 0.3 kg (mean ± standard deviation).MethodsRabbits anesthetized with sevoflurane were intubated with an uncuffed endotracheal tube (3.0 mm internal diameter) and adequate seal. For Pe′CO₂, the sidestream capnometer sampling adapter or the mainstream capnometer was placed between the endotracheal tube and Bain breathing system (1.5 L minute^–1 oxygen). PaCO₂ was obtained from arterial blood collected every 5 minutes. A time-cycled ventilator delivered an inspiratory time of 1 second and 12 or 20 breaths minute^–1. Peak inspiratory pressure was initially set to achieve Pe′CO₂ normocapnia of 35–45 mmHg (4.6–6.0 kPa). A total of five paired Pe′CO₂ and PaCO₂ measurements were obtained with each ventilation mode for each capnometer. Anesthetic episodes were separated by 7 days. Agreement was assessed using Bland-Altman analysis and linear mixed models; p < 0.05.ResultsThere were 90 and 83 pairs for the mainstream and sidestream capnometers, respectively. The mainstream capnometer underestimated PaCO₂ by 12.6 ± 2.9 mmHg (proportional bias 0.44 ± 0.06 mmHg per 1 mmHg PaCO₂ increase). With the sidestream capnometer, ventilation mode had a significant effect on Pe′CO₂. At 12 breaths minute^–1, Pe′CO₂ underestimated PaCO₂ by 23.9 ± 8.2 mmHg (proportional bias: 0.81 ± 0.18 mmHg per 1 mmHg PaCO₂ increase). At 20 breaths minute^–1, Pe′CO₂ underestimated PaCO₂ by 38.8 ± 5.0 mmHg (proportional bias 1.13 ± 0.10 mmHg per 1 mmHg PaCO₂ increase).Conclusions and clinical relevanceBoth capnometers underestimated PaCO₂. The sidestream capnometer underestimated PaCO₂ more than the mainstream capnometer, and was affected by ventilation mode.  相似文献   

高粱新选不育系研究   总被引：5，自引：0，他引：5  

李团银  李三棉 《华北农学报》1993,8(3):56-62

采用不完全双列杂交、人工控制授粉和田间自然鉴定等方法,对6个中晚熟不育系和6个早熟不育系进行了配合力、柱头生活力和其他主要农艺性状鉴定.结果表明,中晚熟不育系中V_4A的一般配合力、柱头生活力、育性、熟期、对丝黑穗病的抗性等综合农艺性状表现最好;早熟不育系中1105A的一般配合力、穗长、千粒重、育性等性状表现较佳.这两个不育系可在我国高粱春播中晚熟区和早熟区加以利用.  相似文献   

Drawing Perspective Projection Free and Easy     

《保鲜与加工》2002,(5):67-70

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AN APPRONTMATE CALCULATING METHOD FOR WALL PLATES OF MAN'' S DRY GAS HOLDERS     

You lihua Wu Huibi Sun Renbo Wang Daivu 《保鲜与加工》1992,(4):48-53

The basic equations of wall plates of MAN' S dry gas holders are derived in this paper. According to the law of cylindrical bending given by the finite element results .we derive some approximate formula calculating the deflection and stresses of the wall plates from the basic equations. Compared with the known approximate calculating method.the method car. obviously increase the percision.  相似文献   

New Method of Founding Profile Equations and Pressure Angle Formula to the Cylindrical Cam Mechanism with Slide Roller-Follower     

NIU Zhi hong  HE Yu lin 《保鲜与加工》2002,(6):23-26

According to existent problems on design and application of the cylindrical cam mechanism with the slide roller-follower, the one correct concept about profile design and pressure angle is presented. Based on this concept, the theoretical profile,practical profile,meshing surface equations and pressure angle formula of the cam mechanism are built up by using opp.rotation analysis and offset surface principle. This method is very simple and clear, and avoids the abstract analysing process in meshing principle. The mathematic models built by this paper can be used to design,manufacture and check this type of cam mechanism correctly, and also create conditions to make deeply meshing property analysis of this mechanism.  相似文献   

THE ANALYSIS OF MECHANICAL CONSTRUCTION OF SURROUNDING ROCKS IN THE PITCHING SEAM     

Cao Shugang 《保鲜与加工》1992,(3):128-133

Defferent forms of mechanical construction, the distribution of stress, and the process of the deformation destruction in the enclosing rocks in a working face of a pitching seam are analyzed according to its geological and mining specialities.  相似文献   

FDTD Method''s Application in the Research of Television Interference From High Voltage Transmission Line     

LIU Qing-song~ 《保鲜与加工》2004,(4):15-19

The mechanism of television interference is discussed from High voltage transmission line. Then the computational model is established, and scattering fields are calculated with the finite-difference time-domain(FDTD) method, and the results are visualized. The scattering effects of High voltage transmission lines on horizontal polarization waves (corresponding to TM mode) are greater than on vertical polarization waves (corresponding to TE mode).  相似文献   

Survey on the Resistance of Soils under Pile-box Foundation of Certain Skyscraper     

CAO Shu-gang~  LIU Yu-cheng~  XU Jian~ 《保鲜与加工》2005,(1):53-55

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Study on Mechanism of the Reinforcing Effect of Geogrid in Soil Dam     

Wen ShuLian  Wang KeZhong 《保鲜与加工》2005,(3):68-71

An experimental study on consolidation and drainage of two gravels with different grading was carried out using high - pressure large - scale tri - axial testing facility. A concept of equivalent surrounding pressure is introduced. An analysis was carried out on the effect and mechanism of reinforcement, experimental surrounding pressure and soil properties. Results show that the reinforcement can improve the strength and failure strain of the material and delay the failure of the soil. The effect of reinforcement of soil - gravel depends on the surrounding pressure and weathering of the gravel.  相似文献   

Robust Adaptive Control Based on On-line Identification to Multi-parameters     

YANG Zhi ping  FENG Su mei 《保鲜与加工》2002,(1):65-69

In system controlled,Sampling these parameters and with parameters for controller in time, it is an object to adaptive control. The article presents a scheme that the structure parameters on it's model and model parameters is robust identified by on line, while to optimal of algorithm on adaptive control is fulfilled. In control scheme, method of intelligent identifying to the structure parameters(levels of model) and algorithm of robust pole placement are introduced also It is advancer for already mentioned scheme. Whole scheme presents new model on adaptive control.  相似文献