bluuebunny/crossref_metadata_2025 huggingface dataset:
Creating a Population of 12‐Digit Headwater Basins within the Albemarle‐Pamlico Estuary System
Authors: Cyterski Mike , Prieto Lourdes
Published: November 2010

Ecological research within the US Environmental Protection Agency's Office of Research and Development has recently changed its focus to quantifying and mapping ecosystem services provided to humans. Our local research group has been charged to develop a regional assessment of several ecosystem services in the Albemarle‐Pamlico Estuary System (APES). Time, data, and funding constraints precluded explicit modeling of the entire APES, so in Phase 1 of our research plan we chose to model ecosystem services in a random sample of headwater catchments. After observing numerous inconsistencies between the National Hydrography Dataset‐Plus (NHDPlus) stream network and the Virginia/North Carolina Watershed Boundary Dataset 12‐digit HUC coverage, we began by creating modified 12‐digit hydrologic units (HUCs) by aggregating smaller catchments delineated within the NHDPlus. In defining our population of interest (headwater 12‐digit HUCs with perennial, natural, wadeable pour points), we generally excluded HUCs that had multiple pour points, no pour points, or whose pour points were intermittent streams, artificial segments, ditches/canals, or lentic systems (lakes and reservoirs). After taking these actions, 318 HUCs remained and a stratified random sample (Omnerik ecoregions as strata) of 50 HUCs was chosen from this population.
A Road Network Selection Process Based on Data Enrichment and Structure Detection
Authors: Touya Guillaume
Published: November 2010

In the context of geographical database generalization, this article deals with a generic process for road network selection. It is based on the geographical context, which is made explicit, and on the preservation of characteristic structure. It relies on literature that is adapted and collected. The first step is to detect significant structures and patterns of the road network such as roundabouts or highway interchanges. It allows the initial dataset to be enriched with explicit geographic structures that were implicit in the initial data. It helps both to make the geographical context explicit and to preserve characteristic structures. Then this enrichment is used as knowledge input for the following step: that is, the selection of roads in rural areas using graph theory techniques. After that, urban roads are selected by means of a block aggregation complex algorithm. Continuity between urban and rural areas is guaranteed by modelling continuity using strokes. Finally, the previously detected characteristic structures are typified to maintain their properties in the selected network. This automated process has been fully implemented on Clarity™ and tested on large datasets.
An Assessment of Deforestation Models for Reducing Emissions from Deforestation and Forest Degradation (REDD)
Authors: Kim Oh Seok
Published: November 2010

With the increasing concerns in developing methodologies for Reducing Emissions from Deforestation and forest Degradation (REDD) projects, there is a need to understand the characteristics of existing Land‐Use/Cover Change (LUCC) modules. This research presents a modular framework for assessing predictive accuracy of business‐as‐usual deforestation in the future by comparing two existing approaches: GEOMOD Modeling (GM) and Land Change Modeler (LCM). The comparison uses data from a case study in Chiquitanía, Bolivia. Data from 1986 and 1994 are used to simulate land‐cover of 2000; the resulting maps are compared with an observed land‐cover map of 2000. GM and LCM simulate business‐as‐usual deforestations at the pixel level. The model structures of GM's linear extrapolation and LCM's Markov Chain are compared to review quantity of LUCC; and the model structures of GM's empirical frequency, LCM's logistic regression, and LCM's multilayer perceptron are compared to review (spatial) allocation of LUCC. Relative operating characteristics, figure of merit, and multiple resolution analysis are employed to assess predictive accuracy of multiple transition modeling. By design, GM lacks the potential to model multiple transitions, and the LCM's multilayer perceptron may produce different results for each simulation due to its stochastic element. Based on the model structure and predictive accuracy comparisons, the LCM seems more suitable than the GM for a REDD application. When a project is to employ a predictive method for its spatially explicit baseline setting, then it is highly recommended to use the proposed framework to assess accuracy of the baseline as part of a project design document.
Modeling the Potential Distribution of Pine Forests Susceptible toSirex NoctilioInfestations in Mpumalanga, South Africa
Authors: Ismail Riyad , Mutanga Onisimo , Kumar Lalit
Published: November 2010

Reducing the impact of the siricid wasp,Sirex noctiliois crucial for the future productivity and sustainability of commercial pine resources in South Africa. In this study we present a machine learning model that serves as a spatial guide and allows forest managers to focus their existing detection and monitoring efforts on key areas and proactively adopt the most appropriate course of intervention. We implemented the random forest model within a spatial framework to determine which pine forests in Mpumalanga are highly susceptible toS. noctilioinfestations. Results indicate that a majority (63%) of pine forest plantations located in Mpumalanga have a high susceptibility (>70%) toS. noctilioinfestation. A KHAT value of 0.84 and F measures above 0.87 indicate that the random forest model is a robust classifier that produces accurate results. Additionally, the use of the backward variable selection method enabled us to simplify the random forest modeling process and identify the minimum number of explanatory variables that offer the best discriminatory power and help in the empirical interpretation of the final random forest model. Overall, the results show that pine forests that experience stress caused by evapotranspiration and evaporation followed by rainfalls, especially during the summer months are more susceptible toS. noctilioinfestations.
SOLIDARITY: RIVAL VERSIONS, CONFLICTING INTERPRETATIONS, AND THE SHAPE OF HOPE
Authors: GUYETTE FRED
Published: November 2010

What do we mean when we utter the word ‘solidarity’? How do we apprehend its meaning when we hear it spoken of by others? The ancient Greeks ‐ Homer, Thucydides, and Aristotle ‐ offer a vantage point from which this inquiry may begin. The Book of Genesis sets before us a cycle of stories about brothers, along with questions about the bonds that keep them together. The sagas of Iceland explore the nature of conflicts between one family and another. Thomas Aquinas gives a distinctive account of solidarity between Christians. Emile Durkheim, too, provides an influential analysis of solidarity. Alexis de Tocqueville, Max Scheler, and Richard Rorty make significant contributions to the discussion. John Paul II elaborated an impressive vision of solidarity. This essay undertakes a form of reconnaissance, then, by exploring the border region between these rival versions of solidarity.
The Aesthetic Collision: Hans Urs von Balthasar on the Trinity and the Cross
Authors: LUY DAVID
Published: November 2010

The relationship envisioned by Hans Urs von Balthasar between the Trinity and the events of Christ's passion and death has elicited concern from various theologians that he has muddled the important distinction between God's eternal life ad intra and his interaction with the world through the economy of his actions. This article argues that such a reading of Balthasar's theology is ultimately a serious misconstrual of his work since it overlooks the aesthetic categories established early in The Glory of the Lord through which his narration of the cross‐event must ultimately be interpreted. By interpreting Balthasar in this manner, this article clarifies the content of what is perhaps Balthasar's most important theological contribution, and provides a creative alternative for how best to situate the relationship (oft‐discussed in twentieth‐century theology) between the Trinity and the crucifixion.
Transnational Migration, Gender, and Rights: Advocacy and Activism in the Malaysian Context
Authors: Elias Juanita
Published: November 2010

This paper explores the intersection between gender and migration through an analysis of the advocacy strategies undertaken by Malaysian non‐governmental organizations (NGOs) and trade unions on behalf of female transnational migrant workers. In particular, the paper looks at the different ways in which local NGOs and trade unions have engaged with the so‐called “rights‐based approach” to migration that has been emphasized by transnational NGOs and key intergovernmental organizations – in particular the International Labour Organization (ILO). The paper suggests that despite the widespread feminization of migration in the region, the rights‐based approach has tended to employ a gender‐blind perspective on migration. It is only in the arena of activism around the rights of migrant domestic workers (an overwhelmingly feminized sector) that gender issues are brought to the fore of the migrant rights debate. The appropriation of rights‐talk by activists organizing on behalf of migrant domestic workers does indicate that the language of human rights can be employed strategically in ways that place the concerns of women workers at their centre. However, there are significant limitations posed by the employment of a human rights “master frame” by pro‐migrant worker activists. These limitations include: the continued association between rights and gender‐blind universal (labour) standards; the linkage between rights and “public sphere” activities outside of the household realm; and the problematic relationship between universal notions of human rights and particularistic notions of citizenship under conditions of political authoritarianism.
“Not a Real Worker”: Gendering Migrants in Thailand’s Shrimp Farms
Authors: Resurreccion Bernadette P. , Sajor Edsel E.
Published: November 2010

Thai shrimp farm‐owners and migrant couple workers from Laos, Myanmar, and Northeast Thailand act in concert to create gendered subjects and a sense of “place” among Surat Thani’s shrimp farms. The creation of place by the migration of workers into Surat Thani is layered by employers’ efficiency goals with migrants’ need for a conjugal residence while earning a living. The conjugal workforce is, however, differentiated by the creation of a female worker subject, publicly defined as “not a real worker.” By paying migrants a couple’s wage, employers recreate and solidify discourses on the work and labour capacities that differentiate women and men on shrimp farms. Women workers themselves reproduce this: they invoke the status of “not a real worker” to achieve certain ends, such as exploring supplementary income sources or creating latitude for child care while still being on the farm’s payroll. It is mostly Thai women who are able to find other income sources, whereas Burmese and Laotian workers are largely tied to their husbands and employers. Women workers’ enactments of “not a real worker” in turn reproduce and differentiate migrant national subjects. This paper therefore demonstrates that labour practices and migration processes produce gender and migrant subjects. This puts in question essentialist and reified assumptions about gender and gender differences. Instead, we place social practices that produce gender subjects at the centre of analysis, thereby being attentive to the production of gender as a dynamic process and the diversity of subject positions available to women in a single context.
Costs of incubation in Common Terns Sterna hirundo: replication and extension of a clutch‐enlargement experiment
Authors: HATCH JEREMY J. , NISBET IAN C. T.
Published: November 2010

Manipulation of clutch size during incubation has been used in a number of studies to investigate life‐history costs of incubation. We increased or decreased clutches of Common Terns Sterna hirundo during incubation and measured subsequent chick growth and productivity. Our results provide little support for the hypothesis that costs of incubation in Common Terns are substantially affected by the number of eggs incubated.
Loss of soil resources from water‐eroded versus uneroded cropland sites under simulated rainfall
Authors: Stavi I. , Lal R.
Published: November 2010

Soil erosion is widespread in agricultural lands of the US Corn Belt. The objective of this study was to examine the impact of antecedent erosion on loss of soil under laboratory simulated rainfall. The soil was obtained from the surface layer of eroded (ER) and uneroded (UN) sites within a conservation agro‐ecosystem in central Ohio, USA. Air‐dried soil was subjected to a rainfall simulation for 60 min (dry run), and to another simulation (wet run) 24 h after the dry run. In the dry run, the cumulative water runoff, sediment yield, and soil organic carbon loss were higher in ER (12.3 L/m2, 169.3 g/m2, and 5.6 g/m2, respectively) than in the UN (7.3 L/m2, 22.6 g/m2, and 0.9 g/m2 respectively). An opposite trend was observed for the cumulative water infiltration (0.9 and 3.9 L/m2, respectively). In the wet run, despite a similar cumulative water runoff from the two erosional phases (20.1 and 19.6 L/m2 in ER and UN respectively), sediment yield and soil organic carbon loss were higher in ER (484.4 g/m2, and 16.3 g/m2 respectively) than in the UN (146.6 g/m2, and 5.3 g/m2 respectively). Also for the wet run, an opposite trend was observed for the cumulative infiltration (0.8 and 5.8 L/m2 respectively). This study suggests that past erosional processes increase the susceptibility of remaining soil to accelerated erosion.
Emotion and underlying concerns during couples' conflict: An investigation of within‐person change
Authors: SANFORD KEITH , GRACE AARON J.
Published: November 2010

This study investigated how emotion changes within persons across different episodes of romantic relationship conflict. Presumably, changes in different types of emotion are linked to changes in the types of underlying adaptive concerns people have during conflict, which in turn are linked to changes in the types of emotion that one's partner is perceived to express. Over the span of 8 weeks, 105 college students in romantic relationships completed between 2 and 5 online assessments of a recent relationship conflict. Hierarchical linear modeling was used to distinguish within‐person effects from between‐person effects. Results confirmed expected differences between types of emotion and types of underlying concern, indicated that most effects occur at the within‐person level, and identified mediating pathways.
Improving transfer printing and ultraviolet‐blocking properties of polyester‐based textiles using MCT‐β‐CD, chitosan and ethylenediamine
Authors: Ibrahim Nabil A , El‐Zairy Enas M R , El‐Zairy Mohammed R , Khalil Heba M
Published: November 2010

This study demonstrates the possibility of improving the transfer printability and fastness properties, as well as the ultraviolet‐protecting functionality, of polyester, polyester/wool, polyester/cotton and polyester/viscose woven fabrics via pretreatment with monochlorotriazinyl β‐cyclodextrin (MCT‐β‐CD), chitosan or ethylenediamine, followed by subsequent transfer printing with sublimable disperse dyes. The modification variables as well as the transfer printing conditions were optimised. The experimental results reveal that generating hydrophobic cavities (via grafting of β‐CD) at the fabric surface, fixing of chitosan, with its amino groups, onto the finish/fabric matrix, or introducing amine functional groups, via aminolysis of the polyester component, results in obtaining transfer printed fabric samples with darker depth of shades and better fastness properties, as well as with higher ultraviolet‐protecting functions. It was further noted that, in all cases, the enhancement in the imparted properties is governed by type of substrate, kind and extent of chemical modification, affinity for the sublimable disperse dyes, accessibility of generated hosting and fixing sites, as well as the ultraviolet‐blocking capacities of the modified/post‐printed substrates against damaging ultraviolet rays. The mode of interaction, as well as the surface morphology of some non‐treated and treated fabric samples, was also investigated.
Fenton and Fenton‐like oxidation of CI Basic Yellow 51: a comparative study
Authors: Eren Zeynep , Acar Filiz Nuran , Ince Nilsun H
Published: November 2010

When ferric ions are substituted for ferrous ions in Fenton’s reagent, the reactions which occur are called Fenton‐like reactions. This study describes the relative efficiency of Fenton (with ferrous ions) and Fenton‐like (with ferric ions) reactions for the degradation of a basic dyestuff, CI Basic Yellow 51, in aqueous solution. Comparisons were made on the basis of the observed reductions in chemical oxygen demand and visible absorption of the dye solutions at optimum reaction conditions. It was found that the Fenton process with 2.63 mm ferrous ion and 39.96 mm hydrogen peroxide at the optimum pH (3.0) eliminated 92.2% of chemical oxygen demand and 98.9% of colour in 22 min, whereas 43.2% of chemical oxygen demand and 64.6% of colour was eliminated by the Fenton‐like process within the same time period, but at pH 4. The efficiency of the latter was significantly improved (to 96.6% removal of colour and 99.7% removal of chemical oxygen demand) by an increase in temperature of 35 °C (from 15 to 50 °C), while no improvements were observed in the efficiency of the Fenton process by temperature elevations.
Synthesis and characterisation of benzothiazole‐based solid‐state fluorescent azo dyes
Authors: Kasture Prakhar P , Sonawane Yogesh A , Rajule Rajkumar N , Shankarling Ganapati S
Published: November 2010

Novel solid‐state fluorescent azo dyes containing a 2‐[4‐(dimethylamino)phenyl]benzo[d]thiazol‐6‐amine as the electron donor group were synthesised. These dyes showed a molar extinction coefficient in the range of 20 000–30 000 l/mol/cm. These compounds were characterised by strong solid‐state fluorescence under long ultraviolet light (365 nm). Absorption and fluorescence spectra revealed that electron coupling originating from broad π‐electron delocalisation and the keto–enol form is responsible for the large Stokes shift. These dyes were readily soluble in common solvents such as dichloromethane, chloroform, dimethyl formamide, tetrahydrofuran and dimethyl sulphoxide and were characterised by means of elemental analysis, proton nuclear magnetic resonance and mass spectrometry. Thermogravimetric analysis of solid‐state fluorescent dyes show thermal stability up to 270 °C and can therefore be used for polymer application. The coloristic properties of these dyes were evaluated on polyester by the disperse dyeing method.
Evaluation of colour fastness and thermal migration in softened polylactic acid fabrics dyed with disperse dyes of differing hydrophobicity
Authors: Avinc Ozan , Wilding Mike , Bone John , Phillips Duncan , Farrington David
Published: November 2010

This paper addresses the relative effects of softeners having different properties and their method of application (exhaust vs pad) on the colour fastness of poly(lactic acid) fabrics dyed with a range of disperse dyes with different levels of hydrophobicity. A comparison was made with a correspondingly finished polyethylene terephthalate fabric. Possible relationships between the levels of hydrophilicity/hydrophobicity of the dye, and softener, and the colour fastness were explored. Finally, the amount of dye thermally migrated into the finish on the softened poly(lactic acid) and polyethylene terephthalate fabrics was examined in comparison with their colour fastness. Softened poly(lactic acid) fabrics dyed with CI Disperse Red 167.1 exhibited more thermal migration, and hence lower colour fastness, than the corresponding polyethylene terephthalate fabrics. Conversely, softened poly(lactic acid) fabrics dyed with Dianix Deep Red SF exhibited less thermal migration, and hence better colour fastness, than the corresponding polyethylene terephthalate fabrics. Overall, no clear relationship was found between the hydrophobic nature of the disperse dye and the hydrophobic character of the softener on the colour fastness.
Technical study of the effect of CO2laser surface engraving on the colour properties of denim fabric
Authors: Kan C W , Yuen C W M , Cheng C W
Published: November 2010

The laser engraving process allows short‐time surface designing of patterns with precision, desired variety, size and intensity on a wide range of textile surfaces with minimum damage to the material. Because of this, it is possible that laser engraving applied to textile materials can make the fabric look faded and worn out without the use of any of the chemicals that are usually required in the conventional colour‐fading process. In the present study, laser engraving was applied to denim fabric in order to evaluate its effect on some colour‐related properties. Two laser process variables, namely, resolution and pixel time, were studied thoroughly. The laser power density was enhanced in response to the increased level of pixel time and resolution. Under the effect of high laser power density, a paler surface appearance was achieved for the denim fabrics with the largely reducedK/Ssumvalues, indicating that the amount of dye present on the denim fabric was decreased significantly. In addition, a green–yellow shade was observed in the denim fabric samples after laser engraving.
Relation Between Renal Dysfunction Requiring Renal Replacement Therapy and Promoter Polymorphism of the Erythropoietin Gene in Cardiac Surgery
Authors: Popov Aron F. , Schulz Egbert G. , Schmitto Jan D. , Coskun Kasim O. , Tzvetkov Mladen V. , Kazmaier Stephan , Zimmermann Janna , Schöndube Friedrich A. , Quintel Michael , Hinz José
Published: November 2010

Several genetic polymorphisms have been identified to play a role in the occurrence and progression of renal dysfunction after cardiac surgery with cardiopulmonary bypass (CPB). Recently, it was demonstrated that the T allele of SNP rs1617640 in the promoter of the erythropoetin (EPO) gene is significantly associated with proliferative diabetic retinopathy (PDR) and end‐stage renal disease (ESRD) due to increased EPO expression. This disease risk‐associated gene and its potential pathway mediating severe microvascular complications in T‐allele carriers could also play a role on renal dysfunction in patients who underwent cardiac surgery with CPB. We hypothesized that the patients' ability to produce increased EPO concentrations will affect morbidity and mortality after CPB. We conducted a prospective single center study between April 2006 and May 2007. In 481 patients who underwent cardiac surgery with CPB we prospectively examined the SNP rs1617640 in the promoter of the EPO gene by DNA sequencing. The patients were grouped according to their genotype (GG, GT, and TT). The genotype distribution of SNP rs1617640 in the promoter of the EPO gene was 36% (TT), 49% (TG), and 15% (GG). There was no difference in age, body mass index, gender, CPB time, or length of stay in intensive care unit. The hospitalization was irrespective of the patients' genotypes. The baseline creatinine in the TT group was 0.2 points higher than in the other groups; however this was without statistical significance in the multivariate analysis. No significant difference was shown in Euroscore, the Simplified Acute Physiology Score II, the Acute Physiology and Chronic Health Evaluation Score II, Acute Renal Failure Score, or the Risk, Injury, Failure, Loss of Kidney Function Score. The mortality was equal across the genotypes. However, an association between the TT genotype and acute renal replacement therapy (P = 0.03), intra‐aortic balloon pump usage (P = 0.02), and serum creatine phosphokinase‐MB increase (P = 0.03) were observed after cardiac surgery. Our analysis suggests that the risk allele (T) of rs1617640 plays a role in the development of renal dysfunction after cardiac surgery with CPB. Patients with the TT risk allele required more frequent acute renal replacement therapy. Since our result is close to the border of significance, this hypothesis should be investigated in larger prospective studies with long‐term follow‐up to emphasize this polymorphism as a potential risk factor.
Evaluation of Neonatal Membrane Oxygenators With Respect to Gaseous Microemboli Capture and Transmembrane Pressure Gradients
Authors: Qiu Feng , Guan Yulong , Su Xiaowei , Kunselman Allen , Ündar Akif
Published: November 2010

A series of studies performed at our center demonstrates that gaseous microemboli (GME) remain a challenge in cardiac surgical procedures. Evaluation of novel oxygenators must address hemodynamic parameters and microemboli capture capability. The objective of this study is to compare two neonatal membrane oxygenators, the Quadrox‐i (MAQUET Cardiopulmonary AG, Hirrlingen, Germany) and the Capiox RX05 (Terumo Corporation, Tokyo, Japan), with respect to GME capture and hemodynamic energy delivery. The experimental circuit included a Maquet HL‐20 heart‐lung machine, a Heater‐Cooler Unit HCU 30 (MAQUET Cardiopulmonary AG), a membrane oxygenator (Quadrox‐i Neonatal or Capiox RX05), and ¼‐inch tubing from the COBE Heart/Lung Perfusion Pack (COBE Cardiovascular, Inc., Arvada, CO, USA). A Capiox cardiotomy reservoir CX*CR10NX (Terumo Corporation) acted as a pseudopatient. The circuit was primed with human packed red blood cells and lactated Ringer's solution and de‐aired according to clinical priming procedure. Heparin (5000 IU) was added into the circuit. The total volume was 400 mL and hematocrit was 30%. Pump flow rate was maintained at 500 or 1000 mL/min under both pulsatile and nonpulsatile modes. All trials were conducted under 100 mm Hg of circuit pressure at normothermia (35°C). In each trial, bolus air (0.5 mL) was injected into the circuit at the prepump site over 5 s. Total emboli counts and total emboli volume were significantly reduced by the Quadrox‐i Neonatal membrane oxygenator compared to the Capiox RX05 membrane oxygenator. Classification and quantification of GME detected at the postoxygenator site at two different flow rates indicated that the Quadrox‐i Neonatal captures the majority of microemboli larger than 40 µm in diameter. The Quadrox‐i Neonatal membrane oxygenator had a higher transmembrane pressure drop at 500 mL/min, whereas it had a lower pressure drop at 1000 mL/min compared to the Capiox Baby RX05 oxygenator. Additionally, the Quadrox‐i Neonatal oxygenator preserved more pulsatile energy than the Baby RX05 oxygenator at both flow rates. Compared to the Capiox RX05 membrane oxygenator, the Quadrox‐i Neonatal membrane oxygenator has significantly improved GME handling capacity and had better hemodynamic energy preservation. Further research encompassing in vivo and clinical studies is needed to investigate the magnitude and mechanisms of these benefits.
Pediatric Extracorporeal Life Support Systems: Education and Training at Penn State Hershey Children's Hospital
Authors: McCoach Robert , Weaver Bonnie , Carney Elizabeth , Clark J. Brian , Pauliks Linda , Guan Yulong , Qiu Feng , Chang Dennis , Reed‐Thurston Deborah , Myers John L. , Ündar Akif
Published: November 2010

The following is a description of the training offered to extracorporeal life support (ECLS)‐trained staff at the Penn State Hershey Children's Hospital. Changes with the ECLS circuit prompted the need for an initiative to train staff in the care of patients requiring ECLS support. In addition to didactic material, we incorporated a “hands‐on” approach in designing the education. During the didactic portion, the circuit was demonstrated as a wet lab. The final step offered a voluntary visit to the animal research facility utilizing clinical case scenarios which allowed participants to articulate and demonstrate proper circuit management. The effort throughout this process was to build a competent ECLS team which will ultimately provide our patients with the greatest chance for a full recovery.
A Microfluidic Device for Continuous White Blood Cell Separation and Lysis From Whole Blood
Authors: Kim Myounggon , Mo Jung Seung , Lee Kyeong‐Hwan , Jun Kang Yang , Yang Sung
Published: November 2010

A microfluidic device, which is composed of a blood inlet, a cell lysis solution inlet, a bifurcation outlet containing six microchannels, and a white blood cell (WBC)‐lysed solution outlet, is proposed in this study to separate WBCs from whole blood and lyse the WBCs in a continuous and near real‐time fashion. The geometry of the microfluidic device is determined based on the bifurcation law and a cell crossover method. The microflow patterns of blood cells in the microfluidic channels are simulated by computational fluid dynamics. The simulation results agree with the experiment results by considering the reduction of blood viscosity in the microfluidic channels. The performance of the microfluidic device is evaluated by investigating the WBC recovery efficiency and the ratio of spectrophotometric absorbance of the blood sample at 260 to that at 280 nm. The WBC recovery efficiency at the main channel outlet is 97.2%. The measured spectrophotometric absorbance ratio of 1.82 indicates that the separated WBCs are completely lysed, leaving only pure DNA in the WBC‐lysed solution. The continuous cell separation and lysis is completed within only 0.5 s. Therefore, it is concluded that the proposed microfluidic device is promising for separating WBCs from whole blood without any pretreatment and lysing the WBCs in a continuous and near real‐time fashion. The proposed microfluidic device may be applicable to a lab‐on‐a‐chip for blood analysis.
The Role of Phospho‐Adenosine Monophosphate‐Activated Protein Kinase and Vascular Endothelial Growth Factor in a Model of Chronic Heart Failure
Authors: Heidrich Florian , Sossalla Samuel , Schotola Hanna , Vorkamp Tobias , Ortmann Philipp , Popov Aron F. , Coskun Kasim O. , Rajab Taufiek K. , Friedrich Martin , Sohns Christian , Hinz Jose , Bauer Martin , Quintel Michael , Schöndube Friedrich A. , Schmitto Jan D.
Published: November 2010

We established a stable and reproducible animal model of chronic heart failure (CHF) in sheep to investigate biomolecular changes. Therefore, two biomarkers, adenosine monophosphate‐activated protein kinase (AMPK) and vascular endothelial growth factor‐A (VEGF‐A) were examined to reveal their role during chronic ischemic conditions of the heart. AMPK was studied because it plays an important role in cellular energy homeostasis and its upregulation is associated with myocardial ischemia, whereas VEGF‐A was studied because it acts as an important signaling protein for neoangiogenesis. We examined 15 juvenile sheep (mean weight, 78 ± 4 kg; control, n = 3; ShamOP, n = 2; coronary microembolization [CME], n = 10). CHF was induced under fluoroscopic guidance by multiple sequential microembolizations (MEs) through bolus injection of polysterol microspheres (90 µm, n = 25.000) into the left main coronary artery. CME was repeated up to three times at 2‐ to 3‐week intervals until animals started to develop stable signs of CHF. All animals were followed for 3 months. Phosphorylation of AMPK, marking the activated protein form, was detected by Western blotting. VEGF‐A and vascular endothelial growth factor‐receptor 2 (VEGF‐R2) mRNA were detected by real‐time polymerase chain reaction. Glyceraldehyde‐3‐phosphate‐dehydrogenase (GAPDH) was used as a reference housekeeping gene. All 10 CHF animals developed clinical signs of CHF as indicated by a significant decrease of cardiac output, decreased ejection fraction, as well as occurrence of tachycardia and tachypnoea. Western blots showed significant phosphorylation of AMPK in CME animals compared to the control group (phospho‐adenosine monophosphate‐activated protein kinase α) (GAPDH control: 0.0, CME left ventricle [LV]: 0.39 ± 0.20, CME right ventricle [RV]: 0.53 ± 0.30; P < 0.05). VEGF‐A and VEGF‐R2 expression in CME animal myocardium was within the range of the control group, but this data did not reach statistical significance due to the small size of this group. While microinjection was performed into the left main coronary artery, phosphorylation of AMPK and expression of VEGF‐A and VEGF‐R2 were significantly higher in the RV than in the LV. Multiple sequential intracoronary MEs can effectively induce myocardial dysfunction with clinical and biomolecular signs of chronic ischemic cardiomyopathy. Quantitative analysis of biomolecular markers showed a significantly higher phosphorylation of AMPK in CHF animals compared with control myocardium.
Differential Immune Activation During Simulated Cardiopulmonary Bypass Procedure Using Freshly Drawn and Week‐Old Blood—A Pilot Study
Authors: Aran Kiana , Fok Alex , Guan Yulong , Sun Qi , Zahn Jeffrey D. , Ündar Akif
Published: November 2010

The goal of this study is to assess whether the use of different aged blood, used during the simulated Penn State Hershey Pediatric cardiopulmonary bypass (CPB) model affects immune activation. In order to study and compare the cytokine release involved in the humoral immune response during simulated CPB, both freshly drawn whole blood used less than 1 h after donation (n = 2) and reconstituted whole blood (1 week old) (n = 3) were circulated in a simulated CPB circuit under identical perfusion conditions. Discrete samples were collected in both experiments and analyzed for the proinflammatory cytokines concentrations of tumor necrosis factor‐alpha, interleukin (IL)‐6, and IL‐8 using immunofluorocytometry as an indicator of immune activation. The results indicated that the cytokine concentrations of freshly drawn blood increased significantly compared with the reconstituted blood over the CPB circulation time. The fresh blood activation was two to three orders of magnitude larger than the week‐old blood for all cytokines analyzed. These results suggest that the use of freshly drawn blood is required to evaluate immune responses to the extracorporeal circulation.
Description of a Flow Optimized Oxygenator With Integrated Pulsatile Pump
Authors: Borchardt Ralf , Schlanstein Peter , Arens Jutta , Graefe Roland , Schreiber Fabian , Schmitz‐Rode Thomas , Steinseifer Ulrich
Published: November 2010

Extracorporeal membrane oxygenation (ECMO) is a well‐established therapy for several lung and heart diseases in the field of neonatal and pediatric medicine (e.g., acute respiratory distress syndrome, congenital heart failure, cardiomyopathy). Current ECMO systems are typically composed of an oxygenator and a separate nonpulsatile blood pump. An oxygenator with an integrated pulsatile blood pump for small infant ECMO was developed, and this novel concept was tested regarding functionality and gas exchange rate. Pulsating silicone tubes (STs) were driven by air pressure and placed inside the cylindrical fiber bundle of an oxygenator to be used as a pump module. The findings of this study confirm that pumping blood with STs is a viable option for the future. The maximum gas exchange rate for oxygen is 48 mL/min/Lblood at a medium blood flow rate of about 300 mL/min. Future design steps were identified to optimize the flow field through the fiber bundle to achieve a higher gas exchange rate. First, the packing density of the hollow‐fiber bundle was lower than commercial oxygenators due to the manual manufacturing. By increasing this packing density, the gas exchange rate would increase accordingly. Second, distribution plates for a more uniform blood flow can be placed at the inlet and outlet of the oxygenator. Third, the hollow‐fiber membranes can be individually placed to ensure equal distances between the surrounding hollow fibers.
Impact of Tubing Length on Hemodynamics in a Simulated Neonatal Extracorporeal Life Support Circuit
Authors: Qiu Feng , Uluer Mehmet C. , Kunselman Allen , Clark J. Brian , Myers John L. , Ündar Akif
Published: November 2010

During extracorporeal life support (ECLS), a large portion of the hemodynamic energy is lost to various components of the circuit. Minimization of this loss in the circuit leads to better vital organ perfusion and decreases the risk of systemic inflammation. In this study, we evaluated the hemodynamic properties of differing lengths of tubing in a simulated neonatal ECLS circuit. The neonatal ECLS circuit used in this study included a Capiox Baby RX05 oxygenator (Terumo Corporation, Tokyo, Japan), a Rotaflow centrifugal pump (MAQUET Cardiopulmonary AG, Hirrlingen, Germany), and a heater and cooler unit. An 8 Fr Biomedicus arterial and a 10 Fr Biomedicus venous cannula were connected to the pseudopatient. One‐fourth inch tubing was used for both the arterial and the venous line. A Hoffman clamp was located upstream from the pseudopatient to maintain a certain patient pressure. Three pressure transducers were placed at different sites: postoxygenator, prearterial cannula, and postarterial cannula. The system was primed with Lactated Ringer's solution; human blood was then added to maintain a hematocrit of 40%. The volume of the pseudopatient was 500 mL. We hemodynamically evaluated three circuits with different lengths of tubing: 6, 4, and 2 feet (182.88, 121.92, and 60.96 cm, respectively) for both arterial and venous lines; the priming volumes including all of the components of the circuits were 195, 155, and 115 mL, respectively. In each circuit, we measured the pressure drops of the arterial tubing and the arterial cannula, as well as the flow rates at different rpm (1750–3000, 250 intervals) under three patient pressures (40, 60, and 80 mm Hg). All the experiments were conducted at 37°C. The pressure drop across the arterial cannula is much larger than that of arterial tubing in all set‐ups, especially under high flow rates. Upon cutting the tubing from 6 to 2 feet, the pressure drop of the arterial tubing decreased by half, while the pressure drop of the arterial cannula increased due to the slightly higher flow rates. These results suggest that compared to the arterial tubing, the arterial cannula has a larger impact on the hemodynamics of the circuit. There is a little influence of tubing length on the circuit flow rate.
Inflammatory and Hemostatic Response to Cardiopulmonary Bypass in Pediatric Population: Feasibility of Seriological Testing of Multiple Biomarkers
Authors: Aĝirbaşli Mehmet , Nguyen My‐Le , Win Khin , Kunselman Allen R. , Clark J. Brian , Myers John L. , Ündar Akif
Published: November 2010

Perioperative myocardial and cerebral damages are the major determinants of postoperative morbidity and mortality in pediatric cardiac surgery. Cardiopulmonary bypass (CPB) causes alterations in the levels of biomarkers related to inflammation, tissue damage, and other tissue pathologies. Early and accurate evaluation of inflammation and tissue damage would therefore be clinically useful. Our objective is to assess the suitability of using Multi‐Analyte Profiling (MAP) (Rules Based Medicine, Austin, TX, USA) in pediatric cardiac surgery as a potential surrogate marker of clinical outcome. MAP technology platform allowed us to analyze 90 different biomarkers using only 100 µL of plasma to detect any changes in the levels of 90 biomarkers. Plasma samples (100 µL) were collected at five different time points: 1. before midline incision; 2. on CPB for 3–5 min; 3. at the end of CPB; 4. 1 h after CPB; and 5. 24 h after CPB. After removing the outliers, the average and standard deviation of the values obtained from the 10 patients were calculated for each time point. The average values of each biomarker at each time point were then compared to each other and to the baseline. The pilot protocol included 10 patients (ages from 3 months to 4 years old) with similar Jenkins risks stratifications who underwent nonpulsatile CPB. We detected changes in the levels of 90 biomarkers. Biomarkers were assessed in groups. Myeloperoxidase (MPO) and pregnancy‐associated plasma protein A (PAPP‐A) were the earliest markers to rise with 49‐ and 18‐fold increases 3–5 min after the onset of CPB, respectively. The most striking increase was noted in the heart‐type fatty acid‐binding protein (FABP) levels. FABP increased 25, 193, 151, and 4‐fold at time points 2, 3, 4, and 5, respectively. Surges in the novel markers of injury were followed by the markers of inflammation (i.e., C‐reactive protein, interleukins) peaking at 24 h after CPB. This pilot study shows that it is possible to measure 90 different biomarkers using only a very small sample of plasma to evaluate the effects of CPB. Novel markers of tissue injury (FABP, PAPP‐A, or MPO) are the earliest markers to rise. Serial monitoring of multiple biomarkers may help to predict and improve outcomes after pediatric cardiac surgery.
Feasibility of Implantable Cardioverter Defibrillator Treatment in Five Patients With Familial Friedreich's Ataxia—A Case Series
Authors: Coskun Kasim Oguz , Popov Aron Frederik , Schmitto Jan Dieter , Coskun Sinan Tolga , Brandes Ivo , Zenker Dieter , Melnychenko Ivan , Schoendube Friedrich Albert , Ruschewski Wolfgang
Published: November 2010

Friedreich's ataxia (FRA) is an autosomal recessive disease of the central nervous system that is associated with familial cardiomyopathy. Cardiac involvement is seen in more than 90% of the patients and is the most common cause of death in these patients. We present a case series and discuss the indications for implantable cardioverter defibrillator (ICD) implantation in FRA with review of the literature. Five pediatric patients who suffer from FRA (four female and one male, mean age 17.4 years) underwent ICD implantation between 2007 and 2008 in the University Hospital of Goettingen. The diagnosis of FRA was established by standard clinical criteria and proven in each case by genotyping at the frataxin locus. The time from diagnosis to ICD implantation was 10.4 ± 1.73 years (range 8–15 years). All patients received transvenous lead systems. There were no intraoperative and postoperative complications. At the latest follow‐up, the neuromuscular symptoms exhibited no further progress and no ICD activations were noticed. Only minor repolarization changes were seen on electrocardiogram. All patients had normal echocardiographic findings and no angina has been reported. Coronary angiographies were normal. It is evident that many FRA patients develop ventricular dysfunction. In the absence of a definitive surgical cure an ICD is generally indicated in young patients with hemodynamically significant sustained ventricular tachyarrhythmias for prevention of sudden cardiac death. Our experience implies the safe use of ICD in children with FRA.
Development of a Force‐Reflecting Robotic Platform for Cardiac Catheter Navigation
Authors: Park Jun Woo , Choi Jaesoon , Pak Hui‐Nam , Song Seung Joon , Lee Jung Chan , Park Yongdoo , Shin Seung Min , Sun Kyung
Published: November 2010

Electrophysiological catheters are used for both diagnostics and clinical intervention. To facilitate more accurate and precise catheter navigation, robotic cardiac catheter navigation systems have been developed and commercialized. The authors have developed a novel force‐reflecting robotic catheter navigation system. The system is a network‐based master–slave configuration having a 3‐degree of freedom robotic manipulator for operation with a conventional cardiac ablation catheter. The master manipulator implements a haptic user interface device with force feedback using a force or torque signal either measured with a sensor or estimated from the motor current signal in the slave manipulator. The slave manipulator is a robotic motion control platform on which the cardiac ablation catheter is mounted. The catheter motions—forward and backward movements, rolling, and catheter tip bending—are controlled by electromechanical actuators located in the slave manipulator. The control software runs on a real‐time operating system‐based workstation and implements the master/slave motion synchronization control of the robot system. The master/slave motion synchronization response was assessed with step, sinusoidal, and arbitrarily varying motion commands, and showed satisfactory performance with insignificant steady‐state motion error. The current system successfully implemented the motion control function and will undergo safety and performance evaluation by means of animal experiments. Further studies on the force feedback control algorithm and on an active motion catheter with an embedded actuation mechanism are underway.
A Three‐Dimensional Bioprinting System for Use With a Hydrogel‐Based Biomaterial and Printing Parameter Characterization
Authors: Song Seung‐Joon , Choi Jaesoon , Park Yong‐Doo , Lee Jung‐Joo , Hong So Young , Sun Kyung
Published: November 2010

Bioprinting is an emerging technology for constructing tissue or bioartificial organs with complex three‐dimensional (3D) structures. It provides high‐precision spatial shape forming ability on a larger scale than conventional tissue engineering methods, and simultaneous multiple components composition ability. Bioprinting utilizes a computer‐controlled 3D printer mechanism for 3D biological structure construction. To implement minimal pattern width in a hydrogel‐based bioprinting system, a study on printing characteristics was performed by varying printer control parameters. The experimental results showed that printing pattern width depends on associated printer control parameters such as printing flow rate, nozzle diameter, and nozzle velocity. The system under development showed acceptable feasibility of potential use for accurate printing pattern implementation in tissue engineering applications and is another example of novel techniques for regenerative medicine based on computer‐aided biofabrication system.
Perioperative Monitoring of Thromboelastograph on Blood Protection and Recovery for Severely Cyanotic Patients Undergoing Complex Cardiac Surgery
Authors: Cui Yongli , Hei Feilong , Long Cun , Feng Zhengyi , Zhao Ju , Yan Fuxia , Wang Yuhong , Liu Jinping
Published: November 2010

In this study, we assessed the clinical effect of a new transfusion therapy guided by thromboelastograph (TEG) on blood protection. Thirty‐one children with severe cyanosis (hematocrit ≥54%), who were diagnosed as having transposition of the great arteries or double outlet right ventricle with or without pulmonary valve stenosis, and underwent arterial switch operation or double roots transplantation, were involved and were divided into two groups. In group F (n = 17), the transfusion therapy after cardiopulmonary bypass was performed with fibrinogen administration combined with traditional transfusion, guided by TEG. In group C (n = 14), traditional transfusion guided by clinical experiences only was performed. We observed the blood protection effects and recovery conditions of these patients. In surgery, compared with group C, the chest closure time, fresh‐frozen plasma (FFP), and platelet (PLT) volume used at closure time had no significant reductions in group F (P > 0.05, respectively), and the patients in group F had no significant reductions in the amount of chest drainage (P > 0.05). The total PLT and total red blood cells usage were also the same (P > 0.05). But during the first 24 h, FFP usage in the intensive care unit (ICU) and total perioperative FFP usage had significantly dropped in group F (P < 0.05); the mechanical ventilator time, ICU stay, and hospitalization time in group F were much shorter than those in group C (P < 0.05). So, TEG was effective in perioperative blood protection. Fibrinogen could be a substitute for FFP to restore hemostasis and improve the prognosis for these patients.