bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on Characteristics of Phase Permeability Curve of Xingbei Development Zone During Extra High Water Cut Period
Authors: Zhang Jianda , Yin Daiyin
Published: July 2023

The relative permeability curve is an important basic data for the preparation and dynamic analysis of oilfield development ( adjustment ) schemes. Due to the different types of relative permeability curves in different water cut stages, there is a large deviation in the prediction of oilfield development indexes in the ultra-high water cut stage according to the relative permeability curve in the early stage of development. In order to study the change of relative permeability curve in the development process, based on the analysis of the morphological characteristics of 118 relative permeability curves in the ultra-high water cut stage of 28 coring wells in Xingbei development area after more than 50 years of water injection development, the influence of injection multiple on the relative permeability curve, and the influence of long-term water injection development on the average pore radius, the changes of morphological characteristics and characteristic parameters of relative permeability curves after entering the ultra-high water cut stage were studied, and a correction method for the changes of oil phase and water phase of relative permeability curves according to the changes of relative permeability curves in different water cut stages was proposed to better reflect the changes of relative permeability curves in the whole process of water injection development. It provides a basis for accurately predicting the index of water injection development oilfield.
Comprehensive Analysis of Collapsible Loess
Authors: Yan Hongxiang , Ma Jianxun , Niu Jianhui , Xie Zhixun , Wang Qize , Zhu Wuwei , Yang Xiao
Published: July 2023

Loess is a kind of special sediment with pore structure and rich carbonate in its composition. Due to the characteristics of structure and composition, most loess has collapsibility. There are rich loess resources distributed in the northwest area of China. With the improvement of the traffic network in the west area, the use of loess as roadbed is gradually increasing. Therefore, during the construction process, the engineering problems encountered by loess also increased, which seriously hindered the construction process of the traffic network. Most of loess in our country is collapsible loess. So the common problem in engineering is how to dispose the collapsibility of collapsible loess.In this paper, the characteristics and evaluation indexes of loess are summarized and studied, the mechanism of loess collapsibility is further explored, and the three methods of loess collapsibility treatment are summarized, which will provide guidance for future engineering problems in collapsible loess areas.
Numerical Study on the Influence of Tidal Inlet Restoration on Water Exchange in Wanning Lagoon
Authors: Zhang Hui , Meng Hui , Zhang Xueqing
Published: July 2023

Wanning Xiaohai is the largest lagoon in Hainan Province. In recent years, the body of water in Xiaohai has been polluted due to the untreated discharge of domestic sewage and aquaculture tailwater directly into Xiaohai. In order to improve the water quality of Xiaohai and relieve the pressure on the water environment, it was decided to restore the tidal inlet of Xiaohai. In this study, the water quality module of the finite volume ocean model was applied to simulate the change of pollution concentration using the Eulerian advection diffusion equation to analyze the half life time and tidal prism before and after the restoration project of the Wanning Xiaohai tidal inlet. The research results showed that after the restoration of the tidal inlet, the half life time of Xiaohai water body changed from 64 d to 58 d, shortened by 6 d, and the tidal prism increased from 8.8×106 m3 to 9.6×106 m3, which can well enhance the exchange between Xiaohai and external water bodies, improve the water quality of Xiaohai and relieve the pressure of water environment.
Lipid Extraction of Black Soldier Fly Larva Using Aqueous Enzymatic and Soxhlet Method
Authors: Wu Lijun , Li Zhijun , Li Jianhang , Fang Haifeng , Qiu Xiaopeng , Fu Pengrui , Zhu Tong
Published: July 2023

This study aimed to explore the efficacy of lipid extraction methods on black solider fly larvae (BSFL) which is a potential sustainable source of biodiesel. The raw fat content of BSFL in exam was 29.6% on dry matter basis, which is comparable to other studies. Both aqueous enzymatic method and Soxhlet method are effective in BSFL lipid extraction at levels around 80%. The lipid quality from aqueous enzymatic method is superior in addition to other merits such as mild, easy and fast. Further research is recommended to scale up its potential as bioenergy alternatives.
Pollution Characteristics, Sources and Assessment of Heavy Metals(Hms) in Surface Sediments of Ningyuan River in Hainan Province, China
Authors: Ma Yingkai , Qiao Zhizhuang , Gao Shengyuan
Published: July 2023

Heavy metals are of wide concern due to their high toxicity, bioaccumulation and non-degradability. In this study, eight heavy metals (Cr, Mn, Ni, Cu, Zn, As, Cd, Pb) in the surface sediments of Ningyuan River were studied to investigate the distribution pattern, pollution status and potential pollution sources, and it was concluded that the concentration distribution of heavy metals in sediments is highly consistent with the population distribution pattern in space and there is a certain degree of risk of Cd pollution, and the heavy metals mainly come from mineral weathering, agricultural and shipping wastes.
An Empirical Study on the Factors Influencing Carbon Emissions in Heilongjiang Province Based on VAR Model
Authors: Li Yang
Published: July 2023

The time series data of Heilongjiang Province from 2000-2019 were selected to measure carbon emissions in Heilongjiang Province according to the IPCC calculation formula. On this basis, a vector autoregressive model between economic growth, industrial structure, energy intensity, energy structure and carbon emissions is established, and the EG test and impulse response function are used to conduct an empirical study. The results show that: there is a long-term equilibrium relationship between carbon emissions and economic scale, industrial structure, energy intensity and energy structure; the optimization of industrial structure and energy structure will suppress the increase of carbon emissions, while the growth of economic scale and energy intensity will promote the increase of carbon emissions.
Study on the Influence of Typical Land Use Type Change on Soil Erosion Resistance in Northeast Black Soil Region
Authors: Zhang Yuehua , Chen Juan , Lv Changxu , Yu Bin , Guo Zongming
Published: July 2023

This paper explores the soil anti-scourability characteristics of land use types in the northeast black soil region, takes the surface soil (0-10 cm) of three main land use types (including natural grassland, sylphus pine plantation and cultivated land) in the typical black soil region as the research object, analyzes the difference of soil anti-scourability coefficient of different land use types, and defines the influence of soil physical and chemical properties and root characteristics on soil anti-scourability. Identify the key factors affecting soil scourability. The results showed that: (1) the soil loss under different land use types changed sharply in the first 2 min of scour, and gradually stabilized with the extension of scour time; On the whole, the soil loss of natural grassland was the smallest, while that of cultivated land was the largest. (2) The soil scourability of different land use types was as follows: natural grassland > plantation forest > cultivated land; Compared with the cultivated land after reclamation, the soil anti-scour property of Pinus sylvestris plantation was significantly improved, and the soil loss was significantly reduced. (3) The geometric characteristic parameters of roots of natural grassland and Pinus sylvestris plantation were significantly higher than those of cultivated vegetation, and the root volume density had the greatest effect on soil anti-scour coefficient. The effects of different diameter classes of fine roots on soil scourability of three land use types were as follows: 1.5-2 mm>1-1.5 mm>0.5-1 mm>0-0.5 mm. This study can provide a theoretical basis for evaluating the soil consolidation and water conservation ability of vegetation in northeast black soil region.
Research on the Accurate Measurement and Analysis of Carbon Emissions by Carbon Real Measurement
Authors: Wang Hanyun , Liu Shengnan , Wang Tao , Hua Mingyu , Huang Jihua , Zhang Boda
Published: July 2023

The practice of carbon emission accurate measurement system application scenario of carbon electricity coupling and carbon real measurement is carried out, based on the carbon constraint background, the whole process of carbon production and emission is accurately pictured, and the carbon measurement real measurement and carbon electricity factor measurement model adapted to multiple industries is constructed in this way. The carbon measurement is carried out by collecting data from power plants in the field and automatically matching various carbon emission parameters with the calculation model to calculate the carbon emissions of the group in real time. Carbon electricity factor measurement for energy data that cannot be directly obtained, build an industry-wide carbon emission measurement and monitoring mechanism driven by electricity ties, and combine with third-party accounting agencies to certify the measurement results to indirectly display carbon emission data by electricity.
Driving Factors of CO2 Concentration in Mainland China Based on GWR
Authors: Renyang Qianqian , Lian Yi , Zhang Hu , Gao Huichun
Published: July 2023

Considering that the complexity and dynamicity of CO2 emissions, the spatiotemporal distribution pattern of atmospheric CO2 and its drivers remain unclear. In this study, we used the Geographically Weighted Regression (GWR) method to analyze the comprehensive distribution of CO2 concentration in mainland China from 2015 to 2019. We considered the relationship between nine factors, including natural and human activities, and CO2 concentration. To clarify the correlation between CO2 concentration and drivers, we utilized Pearson’s correlation coefficient. Then, the GWR analysis revealed the spatial heterogeneity across provinces, which reflects the extent to which impact factors influence CO2 concentrations. Finally, we analysed CO2 concentration spatiotemporal variation characteristics and predicted future trends of CO2 concentration in 31 provinces in China. According to our research, GDP has a major impact on CO2 growth, while natural factors have a minor influence on CO2 concentration. Our study found significant regional differences in the effects of combined variables on CO2 concentrations, with monthly rotational patterns temporally and clustering of high growth rates spatially and CO2 concentration in mainland China will continue to steadily increase. The findings of this research are crucial for China’s future energy low-carbon transition and policy-making.
Research on the Influence of Valve Sensor Fault Based on Simulation
Authors: Ren Zhiping , Dai Chao , Wang Huichao , Wang Heqi , Zhang Yan
Published: July 2023

In the practical application of indoor air quality assurance system, it is difficult to detect the fault of air valves, CO2 sensors and other components, resulting in substandard air quality and increased energy consumption. In this paper, 16 fault conditions and 1 no fault condition were simulated by Simulink simulation software for primary return air conditioning system in summer, and a typical indoor air quality assurance system simulation fault characteristic table was obtained. It is found that PM2.5 sensor fault mainly affects indoor PM2.5 purification speed. The fault of a CO2 sensor affects indoor CO2 dilution and system energy consumption. Small resistance of return air valve increases system energy consumption. Small resistance of supply air valve, exhaust air valve and return air valve decreases the system's ability to control indoor pollutants.
Research and Application of Environmental Protection Standardization System for Energy and Power Companies
Authors: Liu Ye , Zhu QunZhi
Published: July 2023

At present, the national environmental protection is showing a high-pressure and strict management situation, environmental protection requirements are getting higher and higher, environmental protection supervision factors are increasing, and environmental protection law enforcement standards are becoming more and more stringent. Energy and power companies have problems such as weak awareness of environmental protection and law-abiding, imperfect environmental protection management system, inadequate construction and operation management of environmental protection facilities, lack of systematic environmental risk investigation and assessment, and inability to effectively identify and avoid enterprise environmental protection risks. The environmental protection situation faced by enterprises and companies is unprecedentedly severe. Based on the PDCA cycle theory as the theoretical basis for constructing the environmental standardization system of Energy and power companies, and drawing on national standards as the basis for the preparation of the environmental standardization system of Energy and power companies, the "double pre-control" involving ecological and environmental protection, institutional mechanism, daily management, compliance management, ecological protection and restoration governance, air pollution prevention and control (organized), air pollution prevention and control (organized), air pollution prevention and control (unorganized), water pollution prevention and control, Solid waste pollution prevention and control, other pollution prevention and control (noise pollution prevention, gas) and other 10 first-class elements and a number of standards required by the energy and power companies environmental protection standardization system, and invite experts in the field to hold seminars, through experts to view materials, onsite questions, exchange opinions and other methods to improve and improve the environmental protection standardization system of Energy and power companies. based on Analytical Hierarchy Process (AHP), the system elements are reasonably assigned, the scoring criteria of the standardized system are developed, and the final weight scores are obtained through the application in energy and power enterprises to provide energy and power enterprises with ideas of risk self-examination and risk warning to avoid the risk of environmental penalties.
Research on Intelligent Monitoring of Urban Environment under the Environment of the Internet of Things
Authors: Wang Pengyu
Published: July 2023

With the development of the economy, human society has gradually strengthened the emphasis on environmental protection. Environmental monitoring, early warning, and governance have become important worldwide tasks. Traditional urban environmental monitoring relies on environmental monitoring stations. Manual data collection, processing, and analysis often consume a lot of manpower, and at the same time, efficiency and accuracy are lacking. The Internet of Things and sensors enable people to carry out unmanned collection, transmission, and analysis. This paper discusses the research on intelligent monitoring of the urban environment under the Internet of Things, designs the scheme from the software and hardware perspective, and proposes a time series data prediction method based on the Gaussian process. It is hoped that this article can provide some references for applying the collected massive environmental data.
Ecological Environment Security Analysis of Yushu Tibetan Autonomous Prefecture Based on GIS and RS
Authors: Liu Longqing , Teng Ye , Guo Luo
Published: July 2023

Yushu Tibetan Autonomous Prefecture is located in the Three Rivers Source area, which is known as the "water tower of China". However, due to the restriction of natural conditions, the ecological environment of Yushu Prefecture is extremely fragile and its self-recovery ability is poor. Based on the DPSIR concept model, this study collected the ecological environment and socio-economic data of Yushu Tibetan Autonomous Prefecture in 2000, 2005, 2010 and 2015, and established a dynamic evaluation model of ecological security by using expert scoring method and analytic hierarchy process. The weights of each index are determined and the data are standardized to analyze the temporal and spatial changes of ecological security in Yushu area. The results show that the change range of ecological security in Yushu Prefecture is less than 5%, and there is a weak tendency to develop to both ends. In terms of space, the ecological security situation in the southeast of Yushu Prefecture is better than that in the northwest, showing the distribution characteristics of insecurity in the northwest, early warning in the middle and safety in the southeast.
Stability Analysis and Reinforcement Management of Slope
Authors: Cao Yi , Li Huaihai , Long Chunyu , Yang Guangqing , Zhang Chuanting , Peng Dongming
Published: July 2023

The sliding damage occurred on a slope site due to rainfall and other environmental conditions, and the slope stability coefficient was calculated to be 1.05 based on the numerical analysis model of the slope based on the site investigation data, which did not meet the reinforcement requirements of the code. The slope stability coefficient after reinforcement is 1.39, which is 32.4% higher than that before reinforcement, indicating that the reinforcement scheme is feasible.
On the Application of foam Glass in Interior Design
Authors: Wang Wenchao , Chi Jiaqi , Niu Siqi
Published: July 2023

foam glass is the waste glass under the action of other materials to make a new type of mixed material, its itself has good stability, corrosion resistance, heat resistance, not combustion, remain normal at high and low temperature, exposed to oxidation in the air, in building indoor and outdoor insulation, noise reduction, waterproof moisturizing [1], etc. In this paper, through the classification, performance, use and other aspects of foam glass, and through the method of data comparative analysis, the foam glass and various materials are compared, the data show that the foam glass has a good effect than traditional glass and thermal insulation materials.
Research on How to Use Standards to Address Climate Change
Authors: Chen Xinyi , Fang Wei , Zhang Hua
Published: July 2023

Climate change is considered to be the biggest challenge to achieving sustainable development objectives. Climate change mitigation and adaption are two major actions and solutions to address climate change. Mitigation is a lengthy and challenging endeavour, while adaptation is more realistic and urgent. Both are equally important. The ISO climate change guidelines are provided from the perspective of understanding the causes and impacts, measures and methods, principles for addressing climate change strategic planning. The finding of this standard demonstrate the complexity and systematic nature of climate change mitigation, which requires consideration of numerous factors. The principles and methods proposed in this document should be followed when planning the standard system for sustainable development, determining new work projects, and forming standards. According to this document, the formulators of relevant standards should carefully study and understand the relevant content. They should carry out their work under the guidance of this document. The guiding principles for strategic planning are a good place to establish a green manufacturing sub-committee.
Study of Residential Thermal Transfer Values (RTTV) and vertical daylight factors (VDF) for Heavily Obstructed Public Housing Flats
Authors: Li Danny H.W. , Wang Zhenyu
Published: July 2023

Hong Kong, one of the most densely populated cities in the world, consumes more than a quarter of its total energy in residential buildings. The high urban density leaves many residential flats in a heavily obstructed environment,seriously affecting indoor lighting performance. In response, the Hong Kong government issued requirements for residential thermal transfer values (RTTV) and vertical daylight factors (VDF). The control of RTTV and VDF is considered to be effective in improving the energy efficiency and daylighting performance of residential buildings. However, achieving the required RTTV and VDF at the same time can be conflicting in terms of building façade design. This paper studies the daylight performance and energy use of public housing flats facing large sky obstructions through computer simulations. General correlations between RTTV, energy consumption, and daylighting performance are investigated.
Exploring the Path of China's Energy Transformation under the "Carbon Peaking & Carbon Neutrality" Goals
Authors: Li Yan , Zhao Xin , Wang Peng , Yang Yongqi , Li Qiushuang , Liu Zhifan
Published: July 2023

The key to achieving peak carbon emissions and carbon neutrality lies in the low-carbon transformation of energy and power, which is crucial to China's overall economic and social development. With the intensification of global climate change, countries are actively exploring strategies to adapt to climate change. However, coal, as the main future energy source, is expected to remain dominant, making it urgent to advance the transformation of fossil energy towards low-carbonization. In this context, this paper comprehensively analyzes the timing of the reduction of fossil energy and the replacement of non-fossil energy in China through a comparative analysis of the international and domestic energy transformation status, taking into account the need to ensure energy supply security and achieve China's economic and social development goals. The paper proposes development suggestions for China's energy development path, including optimizing and upgrading the industrial structure, building a clean and low-carbon energy system, strengthening CCUS technology development, and leveraging market mechanisms. These recommendations provide a certain reference and guidance for China to achieve its energy transformation goals.
Rat Cardiopulmonary Bypass Model: Application of a Miniature Extracorporeal Circuit Composed of Asanguinous Prime
Authors: You Xiao-Mang , Nasrallah Fadi , Darling Edward , Robins Mike , Nieman Gary , Searles Bruce
Published: July 2023

A clinically relevant rat cardiopulmonary bypass (CPB) model would be a valuable tool for investigating pathophysiological and therapeutic strategies on bypass. Previous rat CPB models have been described in the literature; however, they have many limitations, including large circuit surface area, the inability to achieve full bypass, and donor blood requirements for prime. Therefore, we have established a rat CPB model designed to overcome these limitations. The miniature circuit consisted of a filtered reservoir, heat exchanger, membrane oxygenator (surface area = 0.02 m2) with a static priming volume of 2.8 mL, and an inline blood gas monitor. The circuit was primed with 9.5 ± 0.5 mL of crystalloid solution and CPB was established on male Sprague–Dawley rats (430–475 g, n = 5) by cannulating the left common carotid artery and the right external jugular vein. The animals were placed on CPB at full flow (111 ± 13 mL/kg/min) for 1 hour and were monitored for and additional 2 hours after the CPB procedure. Hemodynamics, hemoglobin concentration (Hb), and blood gases were analyzed at three time intervals: before, during, and after CPB. The circuit performance was evaluated according to prime volume, compliance, hemodynamic parameters, and gas and heat exchange as described by modified AMMI standards. Data are expressed as mean ± SD and a repeated-measures analysis of variance with post-Hoc test was used for data comparison between the three time intervals. The ratio of oxygenator surface area to subject body weight for this model is comparable with that of current human adult CPB practice (0.05 m2/kg vs 0.057 m2/kg) Full CPB was achieved and we observed clinically acceptable PaO2, PaCO2, and SvO2 values (209 ± 86 mmHg, 25 ± 2 mmHg, 78 ± 8%, respectively) while on CPB. The use of asanguinous prime did produce statistically significant Hg reduction (15.7 ± 0.76 vs. 9.2 ± 0.59 g/dL) comparable with clinical practice. No statistically significant differences between pre-and post-CPB hemodynamics and blood gases were found in our study. We have established a miniature circuit consisting of asanquineous prime for a rat CPB model that maintains clinically acceptable results regarding hemodynamic parameters, blood gases, and hemodilution. This model would be valuable for further use in clinically relevant research studies.
In Vitro Validation of the Affinity NT Oxygenator Arterial Outlet Temperatures
Authors: Potger Kieron C. , McMillan Darryl
Published: July 2023

During cardiopulmonary bypass, the rates of cooling and rewarming and the maximum temperatures attained are implicated in patient morbidity. Thus, accurate oxygenator arterial outlet temperature measurements are needed. The purpose of this study was to determine the accuracy of the arterial outlet temperature probe on the “Affinity NT” membrane oxygenator in measuring perfusate temperatures. An in vitro circuit was used. Crystalloid solution was recirculated through an Affinity NT membrane oxygenator and, to simulate the patient, a second oxygenator. Water was recirculated through the heat exchanger of the second oxygenator via a reservoir. A myocardial temperature probe was inserted in-line 4 cm distal to the Affinity NT oxygenator arterial outlet temperature probe and was considered to measure the actual temperature of the perfusate. Temperatures were simultaneously recorded from the in-line probe, arterial outlet probe, and reservoir every second. Twenty-seven trials were run using random combinations of three Affinity NT oxygenators and three in-line probes. Each trial entailed cooling an initially normothermic reservoir to 28°C and then rewarming it to normothermia again. The arterial outlet temperature probe on the Affinity NT membrane oxygenator underestimated the perfusate temperatures during early rewarming (bias of 0.72°C; precision of ±1.15°C) and late rewarming (bias of 0.52°C; precision of ±0.97°C). An overestimation of the perfusate temperatures occurred during early cooling (bias of −0.57°C; precision of ±1.37°C). Only during the late cooling phase was the arterial outlet temperature probe accurate (bias of −0.02°C; precision of ±0.3°C). The perfusionist should be aware of the temperature probe monitoring characteristics of the oxygenator to safely perfuse the patient.
Use of the Quest Myocardial Protection System” (MPS) for Modified Ultrafiltration During Pediatric Cardiac Surgery
Authors: Trowbridge Cody C. , Stammers Alfred H. , Klayman Myra H. , Murdock James D. , Yen Bianca R. , Gilbert Christian L.
Published: July 2023

Modified ultrafiltration generally is considered a standard of care for treating children undergoing cardiopulmonary bypass for congenital heat surgery. Different methods, incorporating a variety of devices and technologies, have been described. The present report describes a technique of modified ultrafiltration using arterial-venous flow with the Quest Myocardial Protection System™ (MPS).
Cardiopulmonary Bypass Using Argatroban as an Anticoagulant for a 6.0-kg Pediatric Patient
Authors: Mejak Brian , Giacomuzzi Carmen , Shen Irving , Boshkov Lynn , Ungerleider Ross
Published: July 2023

A patient was born with transposition of the great arteries, double-outlet right ventricle, interrupted aortic arch, and a ventricular septal defect and underwent a Damus–Kaye–Stansel procedure with a modified Blalock–Taussig shunt at 14 days old. Three months later, this patient presented with hypoxia and bradycardia was found to have a thrombus present in the main pulmonary artery extending to right pulmonary artery. After initiation of thrombolytic therapy, the patient became severely hypoxic and required the institution of extracorporeal membrane oxygenation. As the result of unknown heparin resistance independent of adequate antithrombin III levels, argatroban therapy was used to achieve desired anticoagulation. The patient was taken to the operating room and converted to conventional cardiopulmonary bypass once adequate activated clotting times were achieved using argatroban. This case report summarizes the use of argatroban as an anticoagulant for a 6.0-kg pediatric patient undergoing cardiopulmonary bypass.
The Future of the Perfusion Record: Automated Data Collection vs. Manual Recording
Authors: Ottens Jane , Baker Robert A. , Newland Richard F. , Mazzone Annette
Published: July 2023

The perfusion record, whether manually recorded or computer generated, is a legal representation of the procedure. The handwritten perfusion record has been the most common method of recording events that occur during cardiopulmonary bypass. This record is of significant contrast to the integrated data management systems available that provide continuous collection of data automatically or by means of a few keystrokes. Additionally, an increasing number of monitoring devices are available to assist in the management of patients on bypass. These devices are becoming more complex and provide more data for the perfusionist to monitor and record. Most of the data from these can be downloaded automatically into online data management systems, allowing more time for the perfusionist to concentrate on the patient while simultaneously producing a more accurate record. In this prospective report, we compared 17 cases that were recorded using both manual and electronic data collection techniques. The perfusionist in charge of the case recorded the perfusion using the manual technique while a second perfusionist entered relevant events on the electronic record generated by the Stockert S3 Data Management System/Data Bahn (Munich, Germany). Analysis of the two types of perfusion records showed significant variations in the recorded information. Areas that showed the most inconsistency included measurement of the perfusion pressures, flow, blood temperatures, cardioplegia delivery details, and the recording of events, with the electronic record superior in the integrity of the data. In addition, the limitations of the electronic system were also shown by the lack of electronic gas flow data in our hardware. Our results confirm the importance of accurate methods of recording of perfusion events. The use of an automated system provides the opportunity to minimize transcription error and bias. This study highlights the limitation of spot recording of perfusion events in the overall record keeping for perfusion management.
Distributed Perfusion Educational Model: A Shift in Perfusion Economic Realities
Authors: Austin Jon W. , Evans Edward L. , Hoerr Harry R.
Published: July 2023

In recent years, a steady decline in the number of perfusion education programs in the United States has been noted. At the same time, there has been a parallel decline in the number of students graduated from perfusion educational programs in the United States. Also, as noted by several authors, there has been an increase in demand for perfusion graduates. The decline in programs and graduates has also been noted in anesthesia and surgical residency programs. The shift is caused by a combination of economic and clinical factors. First, decreased reimbursement has led to reallocation of hospital resources. Second, the original enthusiasm for beating heart coronary artery bypass surgery was grossly overestimated and has led to further reallocation of hospital resources and denigration of cardiopulmonary bypass. This paper describes two models of perfusion education programs: serial perfusion education model (SPEM) and the distributed perfusion education model (DPEM). Arguments are presented that the SPEM has some serious limitations and challenges for long-term economic survival. The authors feel the DPEM along with dependence on tuition funding can survive the current clinical and economic conditions and allow the profession to adapt to changes in scope of practice.
Use of Platelet Gel and Its Effects on Infection in Cardiac Surgery
Authors: Trowbridge Cody C. , Stammers Alfred H. , Woods Edward , Yen Bianca R. , Klayman Myra , Gilbert Christian
Published: July 2023

The use of plasmapheresis in cardiac surgery has failed to show an unequivocal benefit. However, the further processing of plasmapheresed blood to obtain a platelet-rich concentrate, termed platelet gel, may reduce patient susceptibility to infection through poorly understood mechanisms related to a combination of platelets, white blood cell content, and expedited wound healing. The purpose of the study was to retrospectively evaluate the incidence wound infections in patients undergoing cardiac surgery. Platelet gel (PG) patients (n= 382) received topical administration of a mixture of platelet concentrated plasma, 10% calcium chloride (5 mL), and bovine thrombin (5000 units). A control group (NoPG,n= 948) operated on concurrently with the treatment group did not receive PG, but otherwise received similar wound care. A historical control (HC,n= 929) included patients operated on before the availability of PG. After Institutional Review Board approval, 20 factors reported in the literature to predispose individuals for increased infection were recorded along with infections classified either as superficial or deep sternal according to the Society of Thoracic Surgeon criteria. All data were obtained from our institutional contribution to the Society of Thoracic Surgeon database. All adult (>19 years of age) patients undergoing cardiac surgery at our institution between October 2002 and June 2005 were included in this study (n= 2259). The incidence of superficial infection was significantly lower in the PG group (0.3%) compared both with the NoPG (1.8%) and HC (1.5%) groups (p< .05). There was a similar relationship found when comparing deep sternal wound infections (PG, 0.0% vs. NoPG, 1.5%;p< .029 and PG vs. HC, 1.7%;p< .01). In conclusion, the application of PG in patients undergoing cardiac surgery seems to confer a level of protection against infection, although the mechanisms of action remain to be elucidated.
Successful Use of a Competency Step Exam in a Perfusion Education Program
Authors: Riley Jeffrey B. , Beckley Philip D. , Tallman Richard D. , Spiwak Allison S.
Published: July 2023

The perfusion education program at The Ohio State University uses a step exam to rank students and identify incompetent students in regard to the program learning objectives. The step exam determines student progress from the didactic to the clinical phase. Each student must pass the competency step exam to gain entry to the clinical rotations. The development, use, and results of the step exam are reported. The design and knowledge matrix establish the content validity of the exam. Single test question discrimination and difficulty statistics identify valid exam items. Examples of the exam’s predictive ability are presented. The step exam is a 200-question exam using multiple choice items. The exam is modeled after several health-related national certification exam processes. The exam has content validity based on the published, written objectives for the education program. Each item on the exam has a history of use and meets criteria for difficulty, discrimination, and distraction. The use of a high-stake competency exam in clinical science and medical education programs is controversial and technically challenging. A step exam to have high-stake consequences must be reliable, meet requirements for content validity, and hopefully exhibit predictive validity.
Use of Thromboelastograph and Factor VII for the Treatment of Postoperative Bleeding in a Pediatric Patient on ECMO After Cardiac Surgery
Authors: Davis Matthew C. , Andersen Niels E.O. , Johansson Per , Andersen Lars W.
Published: July 2023

This report describes a case of possibly fatal bleeding treated successfully with an “overdose” of recombinant factor VII (rFVII; Novo7). A 3.5-year-old boy had surgery for aortic stenosis and aortic arch repair and was placed on extracorporeal membrane oxygenation (ECMO) after a prolonged cardiopulmonary bypass time (CPB); there was subsequent failure to wean from CPB because of right ventricular failure. Subsequently, a severe coagulopathy developed, and despite large volume transfusions with blood and blood products, this was unresolved. Thromboelastograph (TEG) measurements were obtained, and on the advice of the Hematology Department, Novo7 (recommended dose: 15–30 μg/kg) was administered at a dose of 200 μg/kg because of the severity of the bleeding. TEG was repeated, and a further dose of Novo7 was administered at 500 μg/kg; a further TEG after 15 minutes showed normalization, and the remaining bleeding was treated surgically. The patient was weaned from ECMO 48 hours later and was subsequently discharged home with no further problems. Novo7 in an “overdose” can apparently correct major coagulopathy even in patients on ECMO support with no dire effects on the ECMO circuit or the patient in a life-threatening scenario.
Do Surface-Modifying Additive Circuits Reduce the Rate of Cerebral Microemboli During Cardiopulmonary Bypass?
Authors: Rodriguez Rosendo A. , Watson Maura I. , Nathan Howard J. , Rubens Fraser
Published: July 2023

The objective of this study was to determine if surface-modifying additive (SMA) cardiopulmonary bypass (CPB) circuits are associated with a lower rate of cerebral microemboli during CPB compared with standard circuits. In a 2 × 2 factorial design, patients undergoing coronary artery bypass graft surgery were randomized to SMA or standard CPB circuits (with and without methyl-prednisolone). Transcranial Doppler was used to detect high-intensity transient signals (HITS) in both middle cerebral arteries. HITS were counted from onset to end of CPB. Intervals of interest were as follows: period 1, from CPB onset to aortic cross-clamping; period 2, from aortic cross-clamping to immediately before de-clamping; period 3, from aortic de-clamping to before aortic side-clamping; period 4, from the application of the aortic side clamp to immediately before the release of the side clamp; period 5, from aortic side clamp release to the end of CPB. There were 14 patients in each circuit group. No significant differences were found on the partial and total counts of HITS (medians [25th, 75th percentile]) between patients exposed to standard (total count: 228 HITS [174, 280]) and SMA circuits (total count: 156 HITS [104, 356]; p = .427). The median of the sum of HITS per patient associated with perfusionist interventions was not different between both circuit groups (standard: 17 HITS [7, 80]; SMA: 43 HITS [13, 168]; p = .085). This study, with a sample size of 28 patients, indicates that it is unlikely to find any difference in the count of HITS during CPB that is greater than 117 HITS between the two CPB circuits. Moreover, our findings emphasize the relevance of minimizing additional sources of cerebral microembolization during CPB that are not directly related to the biocompatible nature of the SMA CPB circuit.
Integrating Evidence-Based Perfusion Into Practices: The International Consortium for Evidence-Based Perfusion
Authors: Likosky Donald S.
Published: July 2023

There is surmounting pressure for clinicians domestically and abroad not only to practice evidence-based perfusion, but also to supplement practice with documentation thereof. In this editorial, I shall describe an international initiative aimed at embracing this dictum from patients, regulatory bodies, and payers.

“Research is the only hope that the future will be different than the past”—Daniel Mintz, MD

“Practical men who believe themselves to be quite exempt from any intellectual influences are usually the slaves of some defunct economist…. It is ideas not vested interests which are dangerous for good or evil.”—John Maynard Keynes
Whole Blood Thrombin: Development of a Process for Intra-Operative Production of Human Thrombin
Authors: Kumar Vijay , Chapman John R.
Published: July 2023

Thrombin-based clotting agents currently used for topical hemostasis with absorbable sponges, fibrin sealants, and platelet gels are primarily derived from bovine or pooled human plasma sources. Autologous thrombin has important safety advantages in that it does not carry the same safety concerns as pooled plasma-derived products and it avoids exposure to risks associated with bovine-derived proteins. The goal of our research was to develop a rapid, reliable, and simple to perform process to generate autologous human thrombin in the intraoperative setting, from patient whole blood as the starting source material. Using whole blood instead of plasma as the starting material, it is possible to avoid the inherent delay in thrombin availability associated with a primary step of plasma isolation. In this study, we varied several key processing parameters to maximize thrombin production, reproducibility and stability. Autologous thrombin production was generated using a dedicated, single use disposable with a sterile reagent. The disposable consists of a tubular reaction chamber containing glass microsphere beads to activate the alternative pathway of the coagulation cascade. At the end of the process, thrombin-activated serum was harvested from the reaction chamber. The average activity of the thrombin produced at room temperature by this system was 82.8 ± 15.9 IU/mL. The total processing time was <30 minutes. The system was compatible with Anticoagulant Citrate Dextrose-Solution A (ACD-A) (8%–12%). The average volume of thrombin harvested from each aliquot of blood was 7.0 ± 0.3 mL, and the stability of thrombin was observed to be temperature dependent, with cold storage better preserving thrombin activity. Clot times with platelet concentrates at 1:4.3 and 1:11 ratios (thrombin to platelet concentrate) were <10 and 20 seconds, respectively. A process for the preparation of thrombin from whole blood, under conditions compatible with the resources of an operating room, has been developed. The device is simple to use, requires 30 minutes, and can consistently produce thrombin solutions that achieve rapid clotting of platelet concentrates, plasma, and fibrinogen concentrates even when mixed at thrombin to blood product ratios of 1:11.
Improving Outcomes in Patients With Ventricular Assist Devices Transferred From Outlying to Tertiary Care Hospitals
Authors: Anderson Mark B. , Gratz Eric , Wong Raymond K. , Benali Karim , Kung Robert T.V.
Published: July 2023

In this retrospective study, the implant course and outcome of patients with ventricular assist devices (VADs) transferred from outlying “spoke” hospitals and converted nonsurgically to a device designed for ambulation at tertiary care “hub” hospitals are evaluated. Factors affecting the crucial decision to transfer and to convert devices have not previously been characterized. Data from 50 patients at 26 US hub institutions were voluntarily submitted to a VAD data registry at ABIOMED, between December 2003 and December 2005. The patients were transferred from 40 spokes on the BVS 5000 Blood Pump and converted to the AB5000 Ventricle (both ABIOMED) at hubs. Comparisons were made on implant indications, time-course, and end-organ function at the time of conversion between surviving patients and patients that had died. Patients who were transferred and converted had a survival to recovery or to next therapy rate of 42%. Eighteen of the surviving patients were still alive 30 days after the explant: 61% were weaned, 33% were transplanted, and 5.6% received a destination device. Average implant-to-transfer time was 1.5 vs. 2.0 days for 30-day survivors and expired patients, respectively, whereas support time from transfer to conversion was 4.8 vs. 4 days, respectively. At the time of device conversion, a total bilirubin below a threshold level of 3.5 mg/dL was predictive of 30-day survival (n =_26, p = .03, odds ratio = 2.73, 95% confidence interval: 1.22–6.16). Patients who survived 30 days were supported longer than those who died (35 vs. 21.1 days, p = .026). At least 18 patients recovered sufficiently on the AB5000 Ventricle to tolerate extubation and 11 patients were able to ambulate. Liver function after implant both at the spoke and before conversion at the hub may be a good indicator of patient survivability. Patients transferred from the BVS 5000 Blood Pump benefited from easy, safe conversion to the AB5000 Ventricle, which provided them with additional support time and afforded the opportunity to recover native heart function.
Ground Transportation of a Pediatric Patient on ECMO Support
Authors: Machin David , Scott Richard , Hurst Aimee
Published: July 2023

Extracorporeal membrane oxygenation (ECMO) is a technique for providing cardiac and/or pulmonary support. Many hospitals worldwide practice ECMO at some time, yet few centers are able to offer a portable ECMO service, with the United Kingdom being of no exception. We describe the first reported successful ground transfer of a 22-kg girl with suspected myocarditis, supported by veno-arterial ECMO between two hospitals within the United Kingdom (UK). A modified Falcon series 2 patient stretcher was used to transport the patient and house the ECMO hardware, consisting of a Levitronix CentriMag pump system, a Hico-variotherm 550 heater/cooler unit, and an oxygen supply. Design limitations and future technical recommendations of the portable ECMO system subsequent to clinical experience are discussed.
Report of Takotsubo Cardiomyopathy Occurring During Cardiopulmonary Bypass
Authors: Itoh Hideshi , Miyake Yoichiro , Hioki Iwao , Tanaka Satofumi , Okabe Manabu
Published: July 2023

On weaning from cardiopulmonary bypass, a 59-yearold Japanese woman with mitral valve plasty suddenly showed a greatly increased heart rate, and an electrocardiogram revealed elevated ST-segments. There was also abnormal wall motion in the inferior region and apical ballooning of the left ventricle. We diagnosed the condition as takotsubo cardiomyopathy (acute left ventricle apical ballooning syndrome), possibly caused by catecholamine release and regional stress-induced ischemia. We believe this to be the first case report of takotsubo cardiomyopathy observed during heart surgery. We hypothesize that the condition was mediated by regional myocardial stunning and that it could be prevented by administration of angiotensin converting enzyme inhibitors before surgery and by the use of superior biocompatible cardiopulmonary bypass components. Once takotsubo cardiomyopathy occurs, we recommend mechanical circulatory assistance during weaning from the bypass.