bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of mitigation effect of the open- and closed-type check dam
Authors: Lee Seungjun , An Hyunuk , Kim Minseok
Published: August 2023

Debris flow caused by intense rainfall can damage facilities and endanger human life. Accordingly, several models have been developed to predict and mitigate the debris flow damage, for which check-dam construction is essential. There are two types of check dams: open type and closed type. The former is suitable for granular debris flow containing little water, whereas the latter is suitable for water-laden debris flows. However, it is challenging to site the check dam to realize optimal mitigation effects. Therefore, we determined the best check dam location to reduce debris flow damage considering the two types. In this study, we simulated the Raemian apartment basin for the Mt. Umyeon landslides, which occurred in 2011. Constructing the open- and closed type dam at the upper side of the catchment produced the best performance.
Flow-type landslides Impacting V-shaped Diversions: Physical Modelling
Authors: Li Ruoying , Choi Clarence E.
Published: August 2023

In rural and sparsely populated areas, government issued pamphlets often recommend the construction of V-shaped diversions to protect personal property from flow-type landslides hazards, including debris flows. V-shaped diversions are advantageous because they attract low impact forces and runup heights due to their oblique impact angle. However, current design approaches are empirical, so it is unclear what resisting forces and wall heights are required. In this extended abstract, details of a new experimental setup and some preliminary results are presented. It is envisioned that findings from this study will help to shed light on scientific-based recommendations to design V-shaped diversions to enhance the resiliency of mountain communities globally.
The Cheekeye Debris-Flow Barrier – unique features of a proposed open check dam in Canada
Authors: Mark Emily , Strouth Alex
Published: August 2023

The proposed Cheekeye debris-flow barrier in Squamish, BC, Canada is an open check dam with a very large storage capacity of 2.4 million m3. There are several unique features of the design that deviate from standard international practice, including the very low probability (1 in 10,000 years) design event, the use of a single large structure, the selected construction material, the crest design, and the outlet design. These features were selected for the Cheekeye barrier due to idiosyncrasies of the site specifically, and of debris-flow mitigation in Canada, in general.
Spatial distribution of natural debris-flow impact
Authors: Nagl Georg , Kaitna Roland , Hübl Johannes
Published: August 2023

The high destructive potential of debris flows poses a challenge for the design of structural mitigation measures to protect vulnerable areas. An essential part of designing such structures is to determine the magnitude and spatial distribution of the impact forces. The impact is expected to be related to the composition of the flow, which can vary from clay to large boulders along a flow event and between events. Experimental studies are prone to scaling bias and benchmark observations at the full scale are rare so far. Here we present measurements of the temporal and spatial variations of the impact of a natural debris flow in the Gadria creek, IT, onto an instrumented barrier structure. The flow event was preceded by a precursory surge, which was then followed by the debris flow with multiple surges. The flow height reached up to 2.3 m. We found that the impact of boulders occurs primarily in the upper half of the flow profile, the highest forces were measured in first part of the flow, and deposition has a strong influence on the lower part of the structure by damping and/or redirection.
Experimental Study on Structural Behaviour of Steel Wire Mesh under Impact Loading
Authors: Sugimoto Masakazu , Koizumi Kanako , Arita Takeshi , Horiguchi Toshiyuki
Published: August 2023

In view of application to debris flow/rockfall barrier system, several types of steel wire mesh were selected to verify their basic behaviour under impact load of free fall weight at the controlled testing environment at an in-house testing facility capable of dropping a heavy weight on approximately 1-meter square panel made of such steel wire mesh material. Out of the 3 types of wire mesh tested, high-performance chain link endured the highest impact load energy, while newly developed wire mesh showed a high potential of effectively absorbing the impact energy by its plastic deformation along the total length of wire components. Both of the above two types of wire mesh are expected to be applied in flexible type debris flow catchment system in combination with larger opening mesh such as ring net. The newly developed wire mesh consisting of spirally deformed steel wires behaved as energy-absorbing elements while transmitting the impact load to the supporting ropes by its own plastic deformation along the total wire length.
Risk Assessment of Transport Linear Infrastructures to Debris Flow
Authors: Castelli Francesco , Foti Enrico , Lentini Valentina , Pirulli Marina
Published: August 2023

For the assessment of debris flow risk, it is essential to consider not only the triggering and propagation stages but also to perform analyses of its effects and consequences. The study aims at developing a procedure based on a quantitative risk assessments able to estimate the different levels of risk with reference to transport linear infrastructures. This includes numerical modelling for debris flows to determine the zones where the elements at risk could suffer an impact. A detailed comparison between the performances of two different approaches to debris flow modelling was carried out. In particular, the results of a mono-phase Bingham model (FLO-2D) and that of a single-phase model (RASH-3D) with reference to the Enna area (Sicily). The results can be applied for the risk calculations. The purpose is to define a priority of intervention for the identification of the infrastructures exposed at risk, leading to the choice of safety measures.
Practical guide for debris flow and hillslope debris flow protection nets and its application in case studies
Authors: Feiger Nadine , Wendeler Corinna
Published: August 2023

Debris flows and hillslope debris flows endanger people and infrastructures. Technical protection measures are important elements in addition to spatial planning (adapted use of space like hazard maps) and organizational measures (warning systems, emergency plan, evacuation). Additional to other rigid protection measures flexible debris flow nets and hillslope debris flow nets were developed in 2008, and 2010 respectively. Such flexible barriers consist of an interception surface of netting spanned between horizontal support ropes including energy devices and posts for large span width. Since then, they are available on the market worldwide. Many projects were successfully installed and already filled by debris flow events. After more than ten years of experience and demonstrating that these measures work against debris flow and hillslope debris flow, they are fully accepted as possible measures for integral protection against debris flow. To provide planners and engineers the experience and know-how of these flexible protection nets, a practical guide was initiated by the Swiss Federal Roads Office (FEDRO) and Swiss Federal Office for the Environment (FOEN). Two case studies with planned and installed flexible nets, in one case for a debris flow and in the other case for a hillslope debris flow, are presented.
A regional early warning system for debris flows
Authors: Ponziani Michel , Ponziani Denise , Giorgi Andrea , Stevenin Hervé , Ratto Sara Maria
Published: August 2023

In this study, we have developed a predictive model for debris flows using machine learning techniques on a detailed dataset composed by a variety of geomorphological and hydro-meteorological variables. The variables of the dataset were collected from daily measured and modelled data for all of the drainage basins in which at least one debris-flow event was generated during the time period considered (2009-2019). The performances of the models obtained with different machine learning techniques were evaluated with the ROC analysis. The most suitable model was then experimentally implemented in the existing early warning system of the Aosta Valley Region. The model provides daily values of debris-flow probability (DFP) for individual basins, based on the input geo-morphological and hydro-meteorological variables. These results can be used to issue specific debris-flow alerts at the scale of the alert areas of the region.
The seedling landscape: A new challenge for a better conservation of biodiversity in the city
Authors: Ferjani Hanen , Hammami Saida
Published: August 2023

The vegetation in urban areas plays several important roles. Our objective with this manuscript is not to talk about urban ecology but rather to discuss the role that cities can play in biodiversity conservation through the concept of seed-based landscaping. Biodiversity conservation by studying the reintroduction of spontaneous species in urban landscaping projects promotes a more sustainable use and management of local ornamental species. In this paper we will discuss the principles of the ’seedling landscape’ concept and its benefits in biodiversity conservation. Our findings suggest that incorporating the notion of urban ecosystem services can have a crucial impact on restoring the connection between cities and the natural environment. This approach can effectively decrease the ecological impact and environmental burden of urban areas, while simultaneously promoting resilience, well-being, and the overall quality of life for city dwellers.
Ensuring sustainability via accessible transport systems for all in Accra and Kumasi
Authors: Agyemang Ernest , Anderson Brilé , Owusu Kwadwo , Patiño Quinchía Jorge , Trémolières Marie
Published: August 2023

Africa is rapidly urbanising, and transport systems often cannot keep pace, leading to disconnected cities that might entrench car dependency (and preference), along with gender and socioeconomic inequality. In Ghana, transport emissions have risen 75% between 2000 to 2016, along with congestion, pollution and traffic accidents – despite attempts to quell the problem via bans on aged vehicles or more recently, penalties. This paper builds on prior work and argues that putting accessibility at the centre of transport systems will foster sustainability in these cities, yet such data is difficult to find, especially gender-sensitive mobility data. This paper uses a novel approach, combining qualitative and quantitative methods, to study the accessibility across genders in Kumasi and Accra and identify future scenarios for sustainable and accessible systems. This working paper presents preliminary findings.
Investigating factors affecting Paratransit Travel Times: Perspectives from two Paratransit Routes in Kumasi, Ghana
Authors: Ukam George , Adams Charles , Adebanji Atinuke , Ackaah Williams
Published: August 2023

Paratransit trips on minibus vehicles have reportedly been unreliable, and users are unsatisfied with the quality of service they receive. Providing travel-related information, such as travel time information and introducing interventions along the roadway, may improve service quality and user experiences. To do this, there is a need to understand the nature of paratransit travel time and the factors affecting it. The study investigated factors affecting travel times of paratransit at the route and segment levels on two selected routes in Kumasi. A travel time survey onboard the vehicle was used to collect GPS, stop related and other information with the help of a mobile application. The Backward Stepwise Regression technique was used to determine the most significant factors which were drawn from literature and a careful study of paratransit operations. The results indicated that dwell times rather than stops contributed to paratransit travel times. Deviation from the route was found to increase travel time, contrary to the logic of using deviation to bypass apparent traffic congestion ahead. The study proffered interventions that can help improve travel time and the quality of service and made policy suggestions.
A geospatial analysis utilizing AHP and GIS was conducted to assess the suitability of landfill sites for solid waste disposal in the province of Tangier-assilah, Morocco
Authors: Hmamou Mohamed , Chafi Tarik , Ouhammou Imrane , khazaz Lamiaa
Published: August 2023

The objective of this study is to identify the most suitable areas for the implementation of a solid waste landfill in the province of Tangier-Assilah using geographic information systems (GIS). This approach aims to minimize pollution and its negative impacts on the environment and society. In this study, eight environmental, social and economic factors were considered, including residential areas, distance from roads, distance to water bodies, distance to forests, elevation, slope, aspect and parks. To determine the importance of each criterion, the Analytic Hierarchy Process (AHP) was used, based on a pairwise comparison matrix. In addition, a map was produced to indicate the most suitable and unsuitable areas for the solid waste landfill facility. This model can be used to help decision makers make informed decisions and develop effective planning strategies for selecting the most appropriate sites for the landfill.
Evaluation of Five In-Line Hematocrit Monitors
Authors: Niles Scott , Cronbaugh Robert , Engle James , Ploessl James , Sutton Robin
Published: August 2023

Monitoring the hematocrit is essential during cardiopulmonary bypass for efficacious administration of blood products. The purpose of this study was to evaluate five cardiopulmonary bypass in-line monitors designed to display continuous hematocrit or hemoglobin values. The devices were evaluated for accuracy using an in vitro circuit primed with human blood while randomizing hematocrit, blood flow rate, and temperature. Hematocrits correlated significantly with the error in all the devices (p < 0.01). Over evaluation time, the error of the CDI, Gish, IBC, and MX2 increased significantly (p < 0.05). Temperature correlated significantly with the error of the Gish device (r = -0.49, p < 0.01). Blood flow correlated significantly with the Gish error (r = -0.24, p < 0.01). The Cobe device had a significantly smaller overall error than the other devices (p < 0.001). Device evaluation, based on a low mean error, a low percent error, a high correlation with the actual hematocrit, low correlations between mean error, blood flow, and temperature, and insignificant correlation between time and error, suggests that the Cobe device is more accurate for the continuous monitoring of hematocrit during cardiopulmonary bypass.
Perfusion Strategies for Low-Dose and Heparin-Free Bypass
Authors: Bennett John B.
Published: August 2023

An increasing number of clinical reports are being published regarding various uses of heparin-bonded extracorporeal bypass circuits with altered coagulation regimens. Although the reasons for lowered heparinization levels have been discussed, there has been a lack of information detailing perfusion strategies necessary to manage this emerging technology.

The decreased use or elimination of heparin during bypass procedures has been successfully achieved using heparin-bonded surfaces in carefully selected patients. However, if used inappropriately, the results may be catastrophic. Clotted circuits, thrombus formation and increased patient morbidity have resulted from poor circuit design and a poor understanding of the technology. Alterations in blood flow management, circuit design, cardiotomy suction, cardiac chamber venting, bypass weaning and anticoagulation management are essential for improved patient outcome.

It must be stressed that "heparin-bonded" does not imply heparin-free and that any blood damage is magnified under conditions of lowered heparin levels. The risks associated with low-dose or heparin-free bypass must be carefully weighed against the potential beneftis thought to be gained from this strategy.

This report summarizes our current experience, observations and perfusion techniques used in conjunction with low-dose or heparin-free extracorporeal bypass support for selected patients requiring cardiopulmonary bypass, extracorporeal cardiopulmonary support, ventricular assist devices, or extracorporeal membrane oxygenation.
Cardiopulmonary Bypass on a 1.0 Kilogram Infant for Removal of a Trans-Atrial Mycetoma
Authors: Howelton Russell , Benson Cherie , Calhoon John H. , Howelton Linda , Mireles Ruben , Ybarra Jose
Published: August 2023

A premature, 1.0 kilogram infant developed an umbilical venous catheter thrombus which extended through the patent foramen ovale and into the left side of the heart. After consultation with the physicians, the perfusion team was asked to adapt the bypass pump as needed to perfuse the tiny baby. The preparation also included evaluation of a 14 and 16 gauge angiocatheter to be used in the event that the standard 8 Fr. cannula was not sufficient. The mycetoma was excised during circulation arrest. The hematocrit of 20% during bypass was increased to 29% during rewarming of the patient via hemoconcentration. The patient was hemodynamically stable postoperatively and was transferred back to the referring hospital several days later. The patient died six weeks later of sepsis.
Recycling of Renewable Resources in Extra corporeal Circulation Technology
Authors: Bliss Lisa M. , Ecklund Jodie M. , Riley Jeffrey B.
Published: August 2023

This project evaluated the cost effectiveness and feasibility for recycling of renewable resources and disposing of non-recyclable materials generated in the perfusion department of an open heart surgery program. Forty-one adult and pediatric open heart cases were randomly assigned to participate as the control or the recycling group. The control group had no separation of materials. In the recycling group, packaging materials such as glass bottles, corrugated cardboard, and plastics were recycled, providing there was no contamination with blood or body fluids. Non-infectious waste was also separated from infectious waste. The recycled bags, the non-infectious waste bags, and the infectious waste bags were weighed to the nearest one-half pound. The type, weight, and number of bags were recorded. The results from the two groups were analyzed using a one sided Student's t-test. A p value < 0.05 was considered significant. The results indicated that recycling and proper separating of waste significantly decreased the amount of waste discarded as "contaminated". Because contaminated or infectious waste costs $5.60 per red bag and non-infectious waste costs $0.02 per pound, decreasing both forms of waste is economically attractive to hospitals. The perfusionist can decrease the amount of waste products generated in the operating room that must be either incinerated or disposed of in landfill. Recycling and proper separation of waste significantly decreased the expenditure for waste disposal, and decreased the impact of perfusion services on our environment.
Coagulation Monitoring During Extracorporeal Membrane Oxygenation: The Role of Thrombelastography
Authors: Stammers Alfred H. , Willett Lynne , Fristoe Lance , Merrill Jonathan , Stover Todd , Hunt Allen , Morrow John , Newberry Jamie
Published: August 2023

Patients undergoing extracorporeal membrane oxygenation (ECMO) are at an increased risk for developing coagulopathies due to the adverse effects of extracorporeal circulation on the hemostatic mechanism. Methods of determining causative factors of bleeding diathesis are often inconsistent and non-specific. ECMO patients require aggressive transfusion therapy with autogenic blood products to stabilize and maintain hemostasis. The present study evaluated the coagulation status of newborn patients undergoing ECMO therapy, using a viscoelastic monitor (Thrombelastograph -TEG) that measures functional aspects of clot development and stabilization.

Seventeen neonatal patients undergoing ECMO for severe respiratory dysfunction were entered into this study. Serial blood samples were obtained and routine coagulation assessment including fibrinogen concentration, platelet count and ionized calcium was performed. In addition, fibrin ( ogen) degradation products (FDP), d-Dimers, antithrombin III and plasma free hemoglobin were measured. Transfusion indicators were established and total transfusion requirements recorded. TEG profiles were determined with the use of heparinase, an enzyme that degrades heparin but has little effect on other coagulation factors.

The most commonly encountered complication was hemorrhaging which was diagnosed by laboratory and clinical assessment in 11 of 17 patients. Transfusion requirements (measured in ml/kg/ECMO hour) were the following: packed red blood cells - 1.34±0.5; platelets - 0.71 ±o.57; fresh frozen plasma- 0.09±0.12; cryoprecipitate 0.05 ±o.05. Thrombelastograph profiles reflected hemostatic conditions that ranged from severe coagulopathies (DIC) to hypercoagulability. Interpretation of TEG profiles identified hemostatic abnormalities in 57 of 101 profiles ( 46.5% ), with the most common etiology related to platelet dysfunction. In the non-hemorrhagic group the TEG profiles were normal in 30 of 41 (73.2%) instances, while the hemorrhagic group had 24 of60 (40%) profiles in the normal range (p<.001). d-Dimers and FDP were elevated in all patients during ECMO despite maintenance of activated clotting times greater than 180 seconds.

During ECMO coagulation assessment with the TEG provides useful information for the rapid diagnosis of hemorrhagic conditions, which may help guide transfusion therapy.
The Effect of Hypothermia on Heparin Anticoagulation as Measured by Activated Clotting Time and Factor Xa Inhibition
Authors: Tian Lin , Coffin Stacy , Sutton Robin , Murray David , Olson John , Ploessl Jay
Published: August 2023

The effect of hypothermia on heparin anticoagulation was studied using (siliceous earth) activated clotting time (ACT) measured by the modified Hattersley technique and anti-factor Xa assay measured by the modified Teien technique during cardiopulmonary bypass (CPB). Seventeen adult patients with normal blood coagulation function undergoing their first time coronary artery bypass grafting surgery or valve replacement surgery were randomly selected. Blood samples were collected 3-5 minutes after CPB initiation, before cooling at a mean temperature of 32.9°C, and then again after cooling to a mean temperature of 28.4°C. No additional heparin, citrate or packed red blood cells were added to the CPB circuit between sampling points.

The mean heparin concentration measured by the anti-factor Xa assay was 4.1 ± 0.5 units/ml before cooling and 4.1 ± 0.4 units/ml after cooling. The mean ACT was 465 ± 75 seconds prior to cooling and 499 ± 69 seconds at the cold temperature (p<0.05). This suggests that the cooling process itself must induce changes in whole blood coagulation resulting in a prolongation in the ACT. The change in ACT with cooling is not due to a change in heparin concentration. The presented data supports previous research on the inadequacy of ACT to trend heparin concentration when steady state conditions are altered.
Meeting Student Differences in Learning as a Strategy for Improving the Quality of Perfusion Education
Authors: Dake Sue Boettcher , Taylor James A.
Published: August 2023

The quality of perfusion graduates has always been a core concern of perfusion educators. Teaching the student as an individual is a key concept.

This article reviews a learning taxonomy and reminds us about the individual needs of all learners, specific motivators of adult learners, the differences among individual learners, and the effects of stress on learning.

Assessment of each student must be done in all three domains-cognitive, affective, and psychomotor. Subsequently, teaching strategies can be devised which take the learner's individuality into account, and which aim for the creation of a competent and professional entry-level practitioner.
Technical Aspects of Simultaneous Antegrade/Retrograde Normothermic Blood Cardioplegia
Authors: Young Zahir , Saikkonen Maija , Tam Tessa , Ko Aido
Published: August 2023

Techniques of myocardial protection are a source of controversy in the field of cardiac surgery. Numerous studies have been carried out over the years to prove or disprove one method over another. The following techniques: cold vs. warm, antegrade vs. retrograde, and intermittent vs. continuous are some of the most controversial. Cold intermittent antegrade blood cardioplegia has been an accepted routine for many years. However, the use of warm blood cardioplegia has recently sparked much interest, and many studies have recognized its advantages over cold methods.

If cardioplegia is given intermittently, regardless of any other variables, there will be some degree of ischemia with a resultant delay in myocardial recovery. A logical solution to avoid this ischemia is to deliver oxygenated substrate enhanced warm blood cardioplegia continuously and simultaneously via antegrade and retrograde routes for improved regional distribution. This combined technique is described.
Simplified Solution to Eliminating Electrical Noise During Cardiac Surgery
Authors: Johnston Nicklett , Jessen Michael E. , Zeidler Manfred E.
Published: August 2023

Electrical noise will be present in the operating room even under ideal circumstances. The addition of the cardiopulmonary bypass machine to the other machinery in the operating room introduces one more source of electrical noise. Identifying and managing this interference may aid in reducing artifactual signals on the electrocardiogram (EKG) monitor.

If electrical interference occurs during the onset of cardiopulmonary bypass, an uninterpretable rhythm pattern on the electrocardiogram monitor may be present.

Adding an extra ground from the main pump head to the heater/cooler helps to reduce noise and, therefore, effectively diminishes pump-generated artifact on the EKG.
Perfusion During Coronary and Mitral Valve Surgery Utilizing Minimally Invasive Port-Access Technology
Authors: Toomasian John M. , Williams Dorothy L. , Colvin Stephen B. , Reitz Bruce A.
Published: August 2023

Minimally invasive surgery has been used in the treatment of some cardiovascular diseases. Port-Access surgery is a new minimally invasive technique that utilizes cardiopulmonary bypass and a specialized catheter system that provides cardiopulmonary support and myocardial preservation. Extrathoracic cardiopulmonary support is established with femero-femoral bypass with kinetic assisted venous drainage. An endovascular catheter system allows for all the benefits of mechanical support as well as myocardial preservation. This catheter system includes an endoaortic balloon catheter which functions as an aortic cross clamp and antegrade cardioplegia delivery catheter, endopulmonary vent, and endocoronary sinus catheter used for administration of retrograde cardioplegia. An initial cohort of 20 patients was treated by the Port-Access surgical approach with cardiopulmonary bypass. Ten patients had coronary artery surgery and 10 patients had mitral valve surgery. The average bypass times were 94.4 min (coronary artery) and 152.8 min (mitral valve). The mean aortic occlusion times were 49.7 min (coronary artery) and 112.6 min (mitral valve). All patients were weaned from bypass. This initial patient series demonstrated that Port-Access surgery was feasible in selected patients.
Clinical Comparison of Pulsatile and Nonpulsatile Perfusion During Cardiopulmonary Bypass
Authors: Song Zuorui , Wang Chunxiang , Stammers Alfred H.
Published: August 2023

Controversy exists concerning the utilization of pulsatile flow during cardiopulmonary bypass (CPB) with regard to improved patient outcomes. The purpose of the present study was to evaluate pulsatile perfusion in patients undergoing CPB in a clinical setting. Seventy patients undergoing open heart surgery for repair of valvular or congenital heart disease were prospectively entered into the study and were randomly assigned to either pulsatile perfusion (PP, n=35) or nonpulsatile perfusion (NP, n=35) groups. All patients received identical surgical, perfusion, and postoperative care. Study parameters included: rate of spontaneous cardiac conversion, inotropic drug use, urine output, skin temperature, platelet count, fibrinogen concentration, and plasma free hemoglobin level.

There were no statistically significant differences seen in either preoperative or operative parameters between groups. The PP group had a significantly higher rate of spontaneous cardiac conversion, less inotropic drug use, earlier recovery of skin temperature, and higher urine output during CPB (908.8 ± 87.2 ml/hr vs. 606.1 ± 57.5 ml/hr, p < .01). There were no significant differences in either platelet count or fibrinogen concentration between groups. There was a steady increase in plasma free hemoglobin during PP, which was not seen in the NP group (p < .01).

We conclude that the use of pulsatile flow resulted in improved patient outcomes in maintaining better renal function and preserving cardiac function in the early post-bypass period.
The Proposed Use of Performance Indices to Evaluate and Compare the “Gish Vision” Membrane Oxygenator
Authors: Fried David W. , Leo Joseph J. , Zombolas Theodore L. , Mohamed Hasratt , Mattioni Gabriel J.
Published: August 2023

The objective of this investigation was to evaluate and compare the recently released Gish Vision® oxygenator with previously studied oxygenators. We utilized our previously described membrane oxygenator evaluation techniques as well as proposed the use of four new performance indices: 1) oxygen transfer index; 2) shunt fraction index; 3) pressure drop index; and 4) consistency index.

We concluded that the new Gish Vision® membrane oxygenator offers the clinician the highest level of oxygen transfer “reserve” of any oxygenator we have tested. The use of our proposed performance indices enables the perfusionist to quickly and objectively compare various oxygenator performance characteristics and make a meaningful clinical comparison.
Errors in Flow and Pressure Related to the Arterial Filter Purge Line
Authors: Lee-Sensiba Kerri , Azzaretto Nancy , Carolina Clifford , DiCarmine Nancy , Hymowitz Don , Kay Stuart , Kooker Karlene , Salogub Michelle , Wong Elaine , Tamari Yehuda
Published: August 2023

The purge line is a necessary component on arterial filters, although its presence may affect the amount of flow reaching the patient as well as the pump outlet pressure in the extracorporeal circuit. In-vitro and clinical studies conducted to investigate these effects with a commonly used purge line showed that at flows less than 1.5 L/min, rates for pediatric or infant patients, the purge line diverts as much as 40% of the intended pump flow away from the patient. A small diameter resistance tube connected in series with the purge line reduced purge flow such that over 80% of the pump flow reached the patient. Pressure monitored at the arterial filter port with the purge line open could be as much as 45 mmHg lower than the pressure measured with the purge line closed to the filter. Studies should be done to determine if the arterial filter purge line compromises flow to the patient, and if an additional resistance to the purge line is appropriate to reduce the flow through it.
Rigid-body inverse dynamics of a spatial redundantly actuated parallel mechanism constrained by two point contact higher kinematic pairs
Authors: Cheng Chen , Yuan Xiaojing , Chen Yanjie , Dang Yu
Published: August 2023

This paper presents a comparative study of the rigid-body inverse dynamics of a spatial redundantly actuated parallel mechanism constrained by two point contact higher kinematic pairs (HKPs). Firstly, its constrained motions are analysed comprehensively, then four different models are formulated by the generalized momentum approach and the Lagrange-D'Alembert formulation to explore its inverse dynamics. In each method, the first model is built by employing the method directly to the mechanism. In the second model, the dynamic model of its non-redundantly actuated counterpart free of HKPs is built by this approach first, then the constraints from HKPs are modelled, to finally reach the model of the redundantly actuated parallel mechanism (RAPM) where that of its counterpart is utilised as the core. The four models give rise to equivalent numerical results, and the second model in both methods of the RAPM can alleviate the strong coupling between the parasitic motion variables and degrees of freedom (DOFs), boosting the computational speed as fast as that of its non-redundantly actuated counterpart without simplification or loss of accuracy. The comparisons between the mechanism and its counterpart validate that the HKP constraints greatly increase the computational complexity, and the torques required by the parasitic motions of the end effector are significantly smaller than those by the corresponding DOFs.
Migration, interkulturelle Kommunikation und Kindergesundheit
Authors: Grabe Fabian
Published: August 2023

Die Zahl der alltäglich zu behandelnden Patient*innen mit Migrationshintergrund ist groß. Mit einem hohen Anteil an Kindern und Jugendlichen in dieser Bevölkerungsgruppe stellt die ärztliche Behandlung dieser Menschen daher eine alltägliche Aufgabe in der Kinder- und Jugendmedizin dar. Das Aufeinandertreffen verschiedenster kultureller Hintergründe kann in Herausforderungen resultieren, für deren zufriedenstellende Bewältigung die reflektierte Auseinandersetzung mit den fremden, aber auch den eigenen, kulturell geprägten Sicht- und Handlungsweisen zuträglich ist. Gleichzeitig jedoch scheint Zeit als Ressource in Kliniken knapper denn je; Abläufe müssen so effizient wie möglich sein, Personalknappheit besteht auf nahezu allen Positionen. In der Kommunikation wird sich daher meist auf das Wesentliche konzentriert.

Auch wenn aufgrund der so diversen Personengruppe und der enormen Komplexität des Themas stets die Gefahr der Verallgemeinerung und Simplifizierung besteht, sollen hier einige Ideen und Gedanken aufgezeigt werden, die im alltäglichen medizinischen Umgang mit Kindern mit Migrations- oder Fluchthintergrund nützlich sein können.
Lokaltherapie im Kindesalter
Authors: Wohlrab Johannes
Published: August 2023

Kindliche Haut weist, insbesondere im Säuglingsalter, Besonderheiten auf, die es bei der Anwendung von topischen Präparationen zu berücksichtigen gilt. Aus pharmakologischer Sicht sind insbesondere die Gefahr einer erhöhten systemischen Bioverfügbarkeit mit toxikologischer Relevanz und eine eingeschränkte lokale Verträglichkeit von Topika zu nennen. Dies gilt für die unterschiedlichen regulatorischen Kategorien von halbfesten Präparationen (kosmetische Mittel, stoffliche Medizinprodukte und Arzneimittel) in gleicher Weise. Besondere klinische Relevanz kommt einer individuellen Nutzen-Risiko-Abwägung beim Einsatz von toxikologisch relevanten Arzneistoffen (z. B. Salizylsäure) zu. Darüber hinaus erschwert das Fehlen von Zulassungen für topische Arzneimittel im Kindesalter aufgrund juristischer und pharmakologischer Hürden den professionellen Einsatz und begrenzt damit den therapeutischen Nutzen. Vor diesem Hintergrund sind für Arzneistoffe und Präparate mit hoher praktischer Relevanz Daten aus kontrollierten klinischen Studien an Kindern zu fordern.
Delayed Internal Carotid Artery Dissection Mimicking Cerebral Vasospasms after Subarachnoid Hemorrhage: A Case Report
Authors: Lampmann Tim , Dorn Franziska , Schievelkamp Arndt-Hendrik , Banat Mohammed , Vatter Hartmut , Hamed Motaz
Published: August 2023

Background Delayed cerebral ischemia (DCI) is usually caused by cerebral vasospasm (CVS). To detect DCI and CVS, a cranial computed tomography (CT) scan will be performed, but cervical vessels are not necessarily displayed.

Methods A 63-year-old female patient who suffered from aneurysmal subarachnoid hemorrhage (SAH) was treated at the authors' institution. After an initially unremarkable clinical course, she developed aphasia on day 11. CT angiography (CTA) and perfusion imaging revealed significant hypoperfusion of the left hemisphere. In addition, the CTA showed a subtotal stenosis of the internal carotid artery (ICA) at the level of the petrous segment, suspicious for a dissection. This was not detectable angiographically in the final control of the intervention and was also not clinically evident until day 11.

Results Cerebral perfusion as well as the clinical symptoms normalized rapidly after stent reconstruction of the ICA.

Conclusion Even though CVS is the most common cause of hypoperfusion in patients after an SAH, a peri-interventional dissection can also lead to relevant stenosis and thus to a disturbed cerebral perfusion and corresponding neurologic deficits. The time delay between the intervention and the clinical and CTA manifestation in our case is remarkable.
Surgery for Malignant Acute Ischemic Stroke: A Narrative Review of the Knowns and Unknowns
Authors: Krishnan Kailash , Hollingworth Milo , Nguyen Thanh N. , Kumaria Ashwin , Kirkman Matthew A. , Basu Surajit , Tolias Christos , Bath Philip M. , Sprigg Nikola
Published: August 2023

Malignant acute ischemic stroke (AIS) is characterized by acute neurological deterioration caused by progressive space-occupying brain edema, often occurring in the first hours to days after symptom onset. Without any treatment, the result is often fatal. Despite advances in treatment for AIS, up to 80% of patients with a large hemispheric stroke or cerebellar stroke are at risk of poor outcome. Decompressive surgery can be life-saving in a subgroup of patients with malignant AIS, but uncertainties exist on patient selection, predictors of malignant infarction, perioperative management, and timing of intervention. Although survivors are left disabled, most agree with the original decision to undergo surgery and would make the same decision again. In this narrative review, we focus on the clinical and radiological predictors of malignant infarction in AIS and outline the technical aspects of decompressive surgery as well as duraplasty and cranioplasty. We discuss the current evidence and recommendations for surgery in AIS, highlighting gaps in knowledge, and suggest directions for future studies.

Key Points
Ultrasonic tech provides high-resolution contactless respiration monitoring
Authors: Ikenson Ben
Published: August 2023

Continuous monitoring can act as an early warning signal for major respiratory diseases.
Synthesis of naphtho- and pyrazolo-fused systems by an intramolecular Friedel–Crafts approach
Authors: Abd El-Aal Hassan A. K.
Published: August 2023

Efficient access to the tetracyclic pyrazolo-fused carbo- and N-heterocyclic systems: naphtho[2′,1′:3,4]cyclohepta[2,1-c]pyrazolones, naphtho[2′,1′:5,4]azepino[6,7-c]pyrazolones, naphtho[2′,1′:5,4]azocino[6,7-c]pyrazolones and naphtho[2′,1′:6,5]azonino[7,8-c]pyrazolones is described involving intramolecular Friedel–Crafts cycliacylations of synthesized pyrazole-based carboxylic acid or ester derivatives aided by treatment with Lewis and Brønsted acids. The required starting carbaldehyde was obtained by the Vilsmeier–Haack reaction of the corresponding 2-acetylnaphthalene hydrazone. Our developed strategy, involving a three-step route, offers easy access to tetracyclic pyrazole-fused systems in moderate to good yields.
Researching ideologies
Authors: Karizmeh Mojtaba Soleimani , Shahri Naseh Nasrollahi
Published: August 2023

Previous critical studies of language textbook analysis have explored politics of content selection in textbooks,
examining the way selection of certain materials instead of others or the interaction between various multimodal contents selected
for textbooks reinforces certain ideological meanings at the expense of certain others. The current study views language textbooks
through lenses of politics of content creation, analyzing such politics in a series of English as a Foreign Language textbooks
produced by Iranian Ministry of Education. Using a theoretical framework that draws on theories of language ideology and social
semiotic theories of multimodality, the study explores the way ideological meanings are simultaneously created at different orders
of language and the way such created meanings multimodally shape different contents of the textbooks, such as lessons and learning
activities. The study contributes to the filed of critical language textbook analysis by uncovering the relation between power and
ideologies within the generic structure of language textbooks.
Insight into the magnetic behavior and magnetocaloric effect of a borophene monolayer
Authors: An Ying , Wang Wei , Xiao Bo-wen , Huang Si-yu , Xu Zhen-yao
Published: August 2023

The successful discovery of borophene has opened a new door for the development of 2D materials. Due to its excellent chemical, electronic and thermal properties, borophene has shown considerable potential in supercapacitors, hydrogen storage and batteries. In this paper, the thermodynamic characteristics and magnetocaloric effect of borophene are specifically studied using the Monte Carlo method. We find that there is an opposite impact between the spin quantum number and the crystal field on the magnetization, magnetic susceptibility, specific heat and magnetic entropy of the system. Moreover, increasing the spin quantum number or decreasing the absolute value of the crystal field can improve the relative cooling power, the coercivity (h
c), and the remanence (M
R) and the area of the loop.
Effects of Particle Size and Solid Loading on Stereolithography for Preparation of Diamond-Based Composites
Authors: Zhang Zongyan , Zhang Ling , Wang Qiuxia , Huang Jiangtao , Kong Lingbing , Han Peigang , He Bin
Published: August 2023

3D printing is a revolutionary technology that can easily produce complex shapes with low cost and high efficiency. In recent years, technologies for 3D printing have been developed rapidly for polymers, metals, ceramics, and composite materials. Due to its advantages in configuration, 3D printing has also been expected to be a powerful method for preparing diamond-based composites and promoting the applications of diamonds as well. In this paper, stereolithography printing technology is employed to prepare diamond-based composites with special attention to slurry preparation and its stereolithography performance. The impact of diamond particle size, solid loading, and exposure time on the photocuring performance of the diamond slurry are investigated systematically. In addition, the correlation between the thermal conductivity of the printed materials with particle size and solid loading is also studied. The highest thermal conductivity in this study is 1.32 W/(m·K), achieved with an average particle size of 15 μm and a solid loading of 75 wt%. The results show the great potential of preparing diamond-based composites by 3D printing and provide theoretical and technical guidance for further research.
Time Dependence of Viscosity of Alkali-Activated Fly Ash Based Geopolymer Mortar
Authors: Li Yanghang , Zheng Xiong , Wang Jingsong , Yu Xingyu
Published: August 2023

FA was used as the raw material, and the net slurry of FA base Geopolymer was set as the control group to study the influence of sand content, gradation, reaction temperature and time on the time dependence of the viscosity of alkali-activated fly ash based geopolymer mortar. The experimental results show that the curing reaction of alkali-activated fly ash based geopolymer mortar was affected by the temperature dependence of fluid viscosity and the activation energy of the chemical reaction, which is relatively complex. This paper will divide the whole polymerization process into three stages to elaborate. The increase of sand cement ratio will increase the viscosity of FA base polymer mortar. If the sand is too coarse or too fine, the viscosity of FA base polymer mortar will increase significantly, and the fine sand has a greater impact on the viscosity of FA base polymer mortar than the coarse sand. Increasing temperature will significantly accelerate the reaction speed and increase the influence of chemical reaction activation energy on the viscosity of the system while the too high temperature will make the viscosity of the system decrease more significantly in the reaction. This study will reveal the intrinsic relationship between the viscosity of geopolymer and the reaction process, the reaction mechanism of the curing process so that the reaction stage can be represented by the viscosity state of the slurry.
Microstructure and Properties of Cr8 Cold Work Die Steel by Spray Forming, Traditional Casting, and Forging
Authors: Liu Jihao , Zhou Jian , Wu Huibin , Ma Dangshen , Chi Hongxiao
Published: August 2023

In this paper, DC53 cold work dies steel bars with the same specification (φ150 mm) was prepared by spray forming and traditional casting and forging technology. Through the characterization of microstructures using various methods such as OM, SEM, EBSD, and XRD, the mechanical performance testing of hardness, impact resistance, bending strength, and wear resistance, the microstructure characteristics, and mechanical properties differences between the DC53 cold work die steel produced by the two methods were systematically compared. The experimental results show that in terms of microstructure, the carbides in the DC53 cold work die steel produced by the traditional casting and forging process are distributed in a reticular pattern. While the carbide in the DC53 cold work dies steel produced by the spray forming process is finer and uniformly distributed, with higher uniformity across the entire cross-section. In terms of mechanical properties, the DC53 cold work die steel produced by spray forming exhibits superior hardness, impact toughness, bending strength, and isotropy, while the traditional casting and forging DC53 cold work die steel has better wear resistance.
In-plane equivalent modulus of a novel zero Poisson’s ratio honeycomb structure
Authors: Ling He , Wang Zi Hao , Yao Xu Zhao , Xiao Yi Bing
Published: August 2023

This paper proposed a new zero-Possion’s ratio (ZPR) honeycomb structure. The proposed ZPR honeycomb structure improves the traditional semi-reentrant honeycomb structure by introducing vertical cell walls and changing the topological structure between cells to achieve better in-plane deformation capability. The in-plane modulus of the structure was constructed during this research by a mathematical framework and a FEM model. The test specimen of the construction was created using the Stereolithography Apparatus (SLA) technology, and an axial compression experiment was utilized to confirm the model’s accuracy and the zero-ratio Poisson’s property. Geometrical parameters are also investigated to ascertain the relationship between the new zero-Poisson ratio honeycomb structure’s geometrical characteristics and the structure’s flexibility.
Mechanical and permeability tests under the influence of geomembrane temperature
Authors: Ren Hao , Wang Zhifeng
Published: August 2023

Aquatic solar energy cross-season heat-storage technology can store and transfer abundant solar energy from the non-heating season to the heating season, which is one of the important technical routes for renewable energy to be used for clean building heating. Anti-seepage components are an important part of the thermal storage of the water body. As a common anti-seepage material for the thermal storage of the water body, a geomembrane is laid on the pool body and the top cover. In this paper, the mechanical and permeability changes of two kinds of geomembranes are analyzed based on the tests under different temperature environments. The results show that GM1 has better thermal stability. The elongation at break of GM1 increases by 33% and GM2 by 189% when the temperature rises by 40 °C. The osmotic coefficient of GM1 is reduced by 45% and GM2 by 58%.