bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Aachen MiniHLM—A Miniaturized Heart‐Lung Machine for Neonates With an Integrated Rotary Blood Pump
Authors: Arens Jutta , Schnoering Heike , Pfennig Michael , Mager Ilona , Vázquez‐Jiménez Jaime F. , Schmitz‐Rode Thomas , Steinseifer Ulrich 
Published: September 2010

AbstractThe operation of congenital heart defects in neonates often requires the use of heart‐lung machines (HLMs) to provide perfusion and oxygenation. This is prevalently followed by serious complications inter alia caused by hemodilution and extrinsic blood contact surfaces. Thus, one goal of developing a HLM for neonates is the reduction of priming volume and contact surface. The currently available systems offer reasonable priming volumes for oxygenators, reservoirs, etc. However, the necessary tubing system contains the highest volumes within the whole system. This is due to the use of roller pumps; hence, the resulting placement of the complete HLM is between 1 and 2 m away from the operating table due to connective tubing between the components. Therefore, we pursued a novel approach for a miniaturized HLM (MiniHLM) by integrating all major system components in one single device. In particular, the MiniHLM is a HLM with the rotary blood pump centrically integrated into the oxygenator and a heat exchanger integrated into the cardiotomy reservoir which is directly connected to the pump inlet. Thus, tubing is only necessary between the patient and MiniHLM. A total priming volume of 102 mL (including arterial filter and a/v line) could be achieved. To validate the overall concept and the specific design we conducted several in vitro and in vivo test series. All tests confirm the novel concept of the MiniHLM. Its low priming volume and blood contact surface may significantly reduce known complications related to cardiopulmonary bypass in neonates (e.g., inflammatory reaction and capillary leak syndrome).
Patient Satisfaction With the External Equipment of Implantable Left Ventricular Assist Devices
Authors: Meyer Anna L. , Kugler Christiane , Malehsa Doris , Haverich Axel , Strueber Martin 
Published: September 2010

AbstractPatient satisfaction with left ventricular assist device (LVAD) external equipment has not yet been reported. We aimed to evaluate the quality of two different systems based on patients' perspective and its interrelationship with quality of life. Differential assessment of the HeartMate II axial flow pump (n = 17; Thoratec, Pleasanton, CA, USA) and the HVAD centrifugal pump (n = 10; HeartWare, Inc., Miramar, FL, USA) was obtained from 27 outpatients by a questionnaire 2 months to 2.9 years after device implantation. In addition, a health‐related quality of life questionnaire (Short Form‐36 [SF‐36]) was completed. Overall patients' satisfaction was high. Severe limitations were attributed to the loudness of the power base unit in HeartMate II patients (P = 0.00), and HVAD patients were dissatisfied by the length of the driveline (P = 0.02). Between HVAD and HeartMate II patients, no significant differences in the quality of life (assessed by SF‐36) were reported. While the overall satisfaction of outpatients on LVAD support was high, differences between the systems were found. Patients' perspectives may have an important impact on future modification of external components. Ultimately, this may also contribute to an improvement in the quality of life of chronic LVAD patients.
Fully Autonomous Preload‐Sensitive Control of Implantable Rotary Blood Pumps
Authors: Arndt Andreas , Nüsser Peter , Lampe Bernhard 
Published: September 2010

AbstractA pulsatility‐based control algorithm with a self‐adapting pulsatility reference value is proposed for an implantable rotary blood pump and is to be tested in computer simulations. The only input signal is the pressure difference across the pump, which is deduced from measurements of the pump's magnetic bearing. A pulsatility index (PI) is calculated as the mean absolute deviation from the mean pressure difference. As a second characteristic, the gradient of the PI with respect to the pump speed is derived. This pulsatility gradient (GPI) is used as the controlled variable to adjust the operating point of the pump when physiological variables such as the systemic arterial pressure, left ventricular contractility, or heart rate change. Depending on the selected mode of operation, the controller is either a linear controller or an extremum‐seeking controller. A supervisory mechanism monitors the state of the system and projects the system into the region of convergence when necessary. The controller of the GPI continuously adjusts the reference value for PI. An underlying robust linear controller regulates the PI to the reference value in order to take into account changes in pulmonary venous return. As a means of reacting to sudden changes in the venous return, a suction detection mechanism was included. The control system is robustly stable within a wide range of physiological variables. All the clinician needs to do is to select between the two operating modes. No other adjustments are required. The algorithm showed promising results which encourage further testing in vitro and in vivo.
Atrial Versus Ventricular Cannulation for a Rotary Ventricular Assist Device
Authors: Timms Daniel , Gregory Shaun , Hsu Po‐Lin , Thomson Bruce , Pearcy Mark , McNeil Keith , Fraser John , Steinseifer Ulrich 
Published: September 2010

AbstractThe ventricular assist device inflow cannulation site is the primary interface between the device and the patient. Connecting these cannulae to either atria or ventricles induces major changes in flow dynamics; however, there are little data available on precise quantification of these changes. The objective of this investigation was to quantify the difference in ventricular/vascular hemodynamics during a range of left heart failure conditions with either atrial (AC) or ventricular (VC) inflow cannulation in a mock circulation loop with a rotary left VAD. Ventricular ejection fraction (EF), stroke work, and pump flow rates were found to be consistently lower with AC compared with VC over all simulated heart failure conditions. Adequate ventricular ejection remained with AC under low levels of mechanical support; however, the reduced EF in cases of severe heart failure may increase the risk of thromboembolic events. AC is therefore more suitable for class III, bridge to recovery patients, while VC is appropriate for class IV, bridge to transplant/destination patients.
Investigation of the Influence of Volute Design on Journal Bearing Bias Force Using Computational Fluid Dynamics
Authors: Graefe Roland , Timms Daniel , Böhning Fiete , Schmitz‐Rode Thomas , Steinseifer Ulrich 
Published: September 2010

AbstractHydrodynamic fluid film bearings represent an optimal possibility for rotary blood pump (RBP) miniaturization and wear‐free operation. Size is a key parameter in the development of ventricular assist devices (VADs) as smaller patients and the pediatric population become eligible for the device. In order to maintain rotor suspension, radial journal bearings have been widely used in industrial applications as well as in some VADs. A main influence on the performance of such a bearing is the applied hydraulic bias force. This study combines numerical and analytical approaches to determine the bias force of different impeller‐volute configurations and the resulting eccentricity for the hydraulic design point and also for off‐design operation. Significant differences occur for different impeller‐volute configurations, with the circular volute displaying the most beneficial properties for a stable impeller suspension. Moreover, an analytical prediction of eccentricity was found to be incorrect for the relatively small forces that occur in RBPs.
Prediction of the External Work of the Native Heart From the Dynamic H‐Q Curves of the Rotary Blood Pumps During Left Heart Bypass
Authors: Yokoyama Yoshimasa , Kawaguchi Osamu , Kitao Takashi , Kimura Taro , Steinseifer Ulrich , Takatani Setsuo 
Published: September 2010

AbstractThe ventricular performance is dependent on the drainage effect of rotary blood pumps (RBPs) and the performance of RBPs is affected by the ventricular pulsation. In this study, the interaction between the ventricle and RBPs was examined using the pressure‐volume (P‐V) diagram of the ventricle and dynamic head pressure‐bypass flow (H‐Q) curves (H, head pressure: arterial pressure minus ventricular pressure vs. Q, bypass flow) of the RBPs. We first investigated the relationships in a mock loop with a passive fill ventricle, followed by validation in ex vivo animal experiments. An apical drainage cannula with a micro‐pressure sensor was especially fabricated to obtain ventricular pressure, while three pairs of ultrasonic crystals placed on the heart wall were used to derive ventricular volume. The mock loop‐configured ventricular apical–descending aorta bypass revealed that the external work of the ventricle expressed by the area inside the P‐V diagrams (EWHeart) correlated strongly with the area inside dynamic H‐Q curves (EWVAD), with the coefficients of correlation being R2 = 0.869 ∼ 0.961. The results in the mock loop were verified in the ex vivo studies using three Shiba goats (10–25 kg in body weight), showing the correlation coefficients of R2 = 0.802 ∼ 0.817. The linear regression analysis indicated that the increase in the bypass flow reduced pulsatility in the ventricle expressed in EWHeart as well as in EWVAD. Experimental results, both mock loop and animal studies, showed that the interaction between cardiac external work and H‐Q performance of RBPs can be expressed by the relationships “EWHeart versus EWVAD.” The pulsatile nature of the native heart can be expressed in the area underneath the H‐Q curves of RBPs EWVAD during left heart bypass indicating the status of the level of assistance by RBPs and the native heart function.
Development of a Disposable Magnetically Levitated Centrifugal Blood Pump (MedTech Dispo) Intended for Bridge‐to‐Bridge Applications—Two‐Week In Vivo Evaluation
Authors: Nagaoka Eiki , Someya Takeshi , Kitao Takashi , Kimura Taro , Ushiyama Tomohiro , Hijikata Wataru , Shinshi Tadahiko , Arai Hirokuni , Takatani Setsuo 
Published: September 2010

AbstractLast year, we reported in vitro pump performance, low hemolytic characteristics, and initial in vivo evaluation of a disposable, magnetically levitated centrifugal blood pump, MedTech Dispo. As the first phase of the two‐stage in vivo studies, in this study we have carried out a 2‐week in vivo evaluation in calves. Male Holstein calves with body weight of 62.4–92.2 kg were used. Under general anesthesia, a left heart bypass with a MedTech Dispo pump was instituted between the left atrium and the descending aorta via left thoracotomy. Blood‐contacting surface of the pump was coated with a 2‐methacryloyloxyethyl phosphorylcholine polymer. Post‐operatively, with activated clotting time controlled at 180–220 s using heparin and bypass flow rate maintained at 50 mL/kg/min, plasma‐free hemoglobin (Hb), coagulation, and major organ functions were analyzed for evaluation of biocompatibility. The animals were electively sacrificed at the completion of the 2‐week study to evaluate presence of thrombus inside the pump, together with an examination of major organs. To date, we have done 13 MedTech Dispo implantations, of which three went successfully for a 2‐week duration. In these three cases, the pump produced a fairly constant flow of 50 mL/Kg/min. Neurological disorders and any symptoms of thromboembolism were not seen. Levels of plasma‐free Hb were maintained very low. Major organ functions remained within normal ranges. Autopsy results revealed no thrombus formation inside the pump. In the last six cases, calves suffered from severe pneumonia and they were excluded from the analysis. The MedTech Dispo pump demonstrated sufficient pump performance and biocompatibility to meet requirements for 1‐week circulatory support. The second phase (2‐month in vivo study) is under way to prove the safety and efficacy of MedTech Dispo for 1‐month applications.
Simplifying Reading: Applying the Simplicity Principle to Reading
Authors: Vousden Janet I. , Ellefson Michelle R. , Solity Jonathan , Chater Nick 
Published: September 2010

AbstractDebates concerning the types of representations that aid reading acquisition have often been influenced by the relationship between measures of early phonological awareness (the ability to process speech sounds) and later reading ability. Here, a complementary approach is explored, analyzing how the functional utility of different representational units, such as whole words, bodies (letters representing the vowel and final consonants of a syllable), and graphemes (letters representing a phoneme) may change as the number of words that can be read gradually increases. Utility is measured by applying a Simplicity Principle to the problem of mapping from print to sound; that is, assuming that the “best” representational units for reading are those which allow the mapping from print to sounds to be encoded as efficiently as possible. Results indicate that when only a small number of words are read whole‐word representations are most useful, whereas when many words can be read graphemic representations have the highest utility.
Effects of Ambiguous Gestures and Language on the Time Course of Reference Resolution
Authors: Louwerse Max M. , Bangerter Adrian 
Published: September 2010

AbstractTwo eye‐tracking experiments investigated how and when pointing gestures and location descriptions affect target identification. The experiments investigated the effect of gestures and referring expressions on the time course of fixations to the target, using videos of human gestures and human voice, and animated gestures and synthesized speech. Ambiguous, yet informative pointing gestures elicited attention and facilitated target identification, akin to verbal location descriptions. Moreover, target identification was superior when both pointing gestures and verbal location descriptions were used. These findings suggest that gesture not only operates as a context to verbal descriptions, or that verbal descriptions operate as a context to gesture, but that they complement one another in reference resolution.
Three Attempts to Replicate the Behavioral Sunk‐Cost Effect: A Note on Cunha and Caldieraro (2009)
Authors: Otto A. Ross 
Published: September 2010

Abstract Cunha and Caldieraro (2009) investigated whether sunk‐cost effects, which are well documented in hypothetical situations involving monetary investments, also occur in choice situations with purely behavioral investments. Their results suggest that decision makers indeed fall prey to behavioral sunk‐cost effects under certain circumstances. I have been unable to replicate their pattern of results in three separate investigations. In these studies, I attempted to recover the effect using two other behavioral effort manipulations in addition to the manipulation used by Cunha and Caldieraro. This failure to replicate the pattern of results calls into question the robustness of the initial findings.
The Role of Within‐Category Variability in Category‐Based Induction: A Developmental Study
Authors: Rhodes Marjorie , Brickman Daniel 
Published: September 2010

AbstractThe present studies tested the hypothesis that strong assumptions about within‐category homogeneity impede children’s recognition of the inductive value of diverse samples of evidence. In Study 1a, children (7‐year‐olds) and adults were randomly assigned to receive a prime emphasizing within‐category variability, a prime emphasizing within‐category similarities, or to not receive a prime. Only following the variability prime, children demonstrated a reliable preference for evaluating diverse over nondiverse samples to determine whether there is support for a category‐wide generalization. Adults demonstrated a robust preference for diverse samples in all conditions. These effects extended beyond the specific categories included in the prime, as well as to multiple types of test questions. Study 1b demonstrated that priming variability leads children to select diverse samples only when doing so is informative for induction. Implications for conceptual development are discussed.
The Opposite of Republican: Polarization and Political Categorization
Authors: Heit Evan , Nicholson Stephen P. 
Published: September 2010

AbstractTwo experiments examined the typicality structure of contrasting political categories. In Experiment 1, two separate groups of participants rated the typicality of 15 individuals, including political figures and media personalities, with respect to the categories Democrat or Republican. The relation between the two sets of ratings was negative, linear, and extremely strong, r = −.9957. Essentially, one category was treated as a mirror image of the other. Experiment 2 replicated this result, showing some boundary conditions, and extending the result to liberal and conservative categories. The same method was applied to two other pairs of contrasting categories, healthy and junk foods, and male and female jobs. For those categories, the relation between contrasting pairs was weaker and there was less of a direct trade‐off between typicality in one category versus typicality in its opposite. The results are discussed in terms of implications for political decision making and reasoning, and conceptual representation.
Geographic variation in male courtship acoustics and genetic divergence of populations of the Cotesia flavipes species complex
Authors: Joyce A.L. , Bernal J.S. , Vinson S.B. , Hunt R.E. , Schulthess F. , Medina R.F. 
Published: September 2010

AbstractCourtship behaviors of insect populations can vary across the range of a species. Populations exhibiting divergent courtship behavior may indicate genetic divergence or cryptic species. Courtship acoustic signals produced by male wing fanning and genetic structure (using amplified fragment length polymorphisms) were examined for seven allopatric populations of the Cotesia flavipes (Hymenoptera: Braconidae) species complex, using four C. sesamiae (Cameron) and three C. flavipes Cameron populations. Members of this species complex parasitize lepidopteran pests in gramineous crops including sugarcane, maize, and rice. Significant variation was detected in courtship acoustic signals and genetic structure among populations of both species. For C. sesamiae, courtship acoustic signals varied more between populations of two biotypes that were collected near an area of sympatry. The two biotypes of C. sesamiae were also genetically divergent. For C. flavipes, significant differences in acoustic signals and genetic structure occurred among allopatric populations; these differences support the recent designation of one population as a new species. Courtship acoustics play a role in reproductive isolation in this species complex, and are likely used in conjunction with chemical signals. Ecological factors such as host range and host plant use may also influence the divergence of both courtship acoustic signals and genetic structure among populations in the C. flavipes complex.
Recent highlights on bone stem cells: a report from Bone Stem Cells 2009, and not only…
Authors: Cenni Elisabetta , Perut Francesca , Baglío Serena Rubina , Fiorentini Elisa , Baldini Nicola 
Published: September 2010

Abstract

Introduction
Sources of stem cells for bone regeneration
Markers for the identification of adult bone stem cells
Molecular aspects of bone stem cells
Signaling pathways of osteoblast differentiation
Control of bone remodelling by the nervous system

In vivo models
Orthopaedic applications of bone stem cell technology
Conclusions

The use of stem cells has opened new prospects for the treatment of orthopaedic conditions characterized by large bone defects. However, many issues still exist to which answers are needed before routine, large‐scale application becomes possible. Bone marrow stromal cells (MSC), which are clonogenic, multipotential precursors present in the bone marrow stroma, are generally employed for bone regeneration. Stem cells with multilineage differentiation similar to MSC have also been demonstrated in adipose tissue, peripheral blood, umbilical cord and amniotic fluid. Each source presents its own advantages and drawbacks. Unfortunately, no unique surface antigen is expressed by MSC, and this hampers simple MSC enrichment from heterogeneous populations. MSC are identified through a combination of physical, morphological and functional assays. Different in vitro and in vivo models have been described for the research on bone stem cells. These models should predict the in vivo bone healing capacity of MSC and if the induced osteogenesis is similar to the physiological one. Although stem cells offer an exciting possibility of a renewable source of cells and tissues for replacement, orthopaedic applications often represent case reports whereas controlled randomized trials are still lacking. Further biological aspects of bone stem cells should be elucidated and a general consensus on the best models, protocols and proper use of scaffolds and growth factors should be achieved.
Genes, proteins and complexes: the multifaceted nature of FHL family proteins in diverse tissues
Authors: Shathasivam Thiruchelvi , Kislinger Thomas , Gramolini Anthony O. 
Published: September 2010

Abstract

Overview
FHL1: structure, organization, and function
FHL1 and disease
Perspectives

Four and a half LIM domain protein 1 (FHL1) is the founding member of the FHL family of proteins characterized by the presence of four and a half highly conserved LIM domains. The LIM domain is a protein‐interaction motif and is involved in linking proteins with both the actin cytoskeleton and transcriptional machinery. To date, more than 25 different protein interactions have been identified for full length FHL1 and its spliced variants, and these interactions can be mapped to a variety of functional classes. Because FHL1 is expressed predominantly in skeletal muscle, all of these proteins interactions translate into a multifunctional and integral role for FHL1 in muscle development, structural maintenance, and signalling. Importantly, 27 FHL1 genetic mutations have been identified that result in at least six different X‐linked myopathies, with patients often presenting with cardiovascular disease. FHL1 expression is also significantly up‐regulated in a variety of cardiac disorders, even at the earliest stages of disease onset. Alternatively, FHL1 expression is suppressed in a variety of cancers, and ectopic FHL1 expression offers potential for some phenotype rescue. This review focuses on recent studies of FHL1 in muscular dystrophies and cardiovascular disease, and provides a comprehensive review of FHL1s multifunctional roles in skeletal muscle.