Volume Manipulation Research Articles

Porous carbon-based materials for hydrogen storage: advancement and challenges

The development of highly efficient hydrogen storage materials is one of the main challenges that must be tackled in a widely expected hydrogen economy. Physisorption in porous materials with high surface areas and chemisorption in hydrides are the two main options for solid state hydrogen storage, and both options possess their inherent advantages and drawbacks. In this work, recent progress towards porous carbon-based materials for hydrogen storage is analyzed and reviewed. The hydrogen storage performance of plain porous carbons, metal-supported porous carbons and porous carbons confined hydrides is summarized. Some strategies for effectively controlling the hydrogen storage capacity and tuning the hydrogen adsorption enthalpy for porous carbon materials via appropriate manipulation of surface area, pore volume and pore size are discussed in detail. The new development of porous carbon-based materials for hydrogen storage is particularly emphasized.

Comparative study on the effects of reduced PCR reaction volumes and increased cycle number, on the sensitivity and the stochastic threshold of the AmpFlSTR Identifiler® Plus kit

The purpose of this study is to compare the performance of reduced volume PCR reactions with the Identifiler Plus kit and to investigate the influence on the sensitivity and stochastic occurrences under standard and increased thermal cycling conditions.Among the three volumes, sensitivity and stochastic effects appeared to be unchanged within each cycling condition. Under the increased cycle condition, the sensitivity was higher than under standard cycling conditions but there was also a consequent increase in background noise and stochastic threshold. The limitation of reducing volumes appears to be mainly due to the challenge of small volume manipulation. A 10μL final volume proved to be both efficient and economical while simultaneously significantly decreasing the amount of evidence consumed.

289 STEM CELL CULTURE AND DIFFERENTIATION IN MICROFLUIDIC DEVICES

Advancements in micro and nanotechnology have allowed scientists a powerful platform to study biological systems. Microfluidics is one area of advancement with great promise. Microfluidics deals with the behaviour, specific control, and manipulation of microliter and nanoliter volumes of fluid. The small-scale design of these microfluidic devices permits laminar flow, characterised as parallel streams flowing without disruption between currents. With the introduction of micro-technology and microfluidic platforms for cell culture, stem cell research can be put into a new context. Inside microfluidics, microenvironments can be more precisely controlled and they provide a more in vivo-like environment for the cells to grow and hence can serve as a better way of culturing the cells. In the current study, we examined the influence of microfluidic devices on the development of stem cells. Adipose-derived stem cells (ADSC) were isolated from pigs and seeded in a microfluidic device to differentiate toward adipogenic, osteogenic, and chondrogenic lineages using specific differentiation-promoting media (Monaco et al. 2009 Open Tissue Eng. Regen. Med. J. 2, 20–33). Five thousand cells were seeded per channel at a density of 5 000 000 cells mL–1. The microchannel dimensions were 5 mm long, 1 mm wid, and 200 µm deep. Cells were maintained for 14 days and then stained with respective staining dyes: Oil Red O for adipogenesis, Alizarin Red for osteogenesis, and Toluidine Blue for chondrogenesis. Cells differentiated towards adipogenic lineage contained small lipid droplets, which stained red with Oil Red O stain; during osteogenic differentiation, the cells formed large nodules and stained positive for the presence of calcium; and the chondriogenic differentiating cells showed the presence of proteoglycans (blue) when stained with Toluidine Blue. We seeded ADSC in 5 channels for each differentiation lineage, and all channels gave positive staining results. We conclude that microfluidic channels support proliferation and differentiation of ADSC. This system uses small amounts of culture medium, experiments with different culture compositions can be efficiently performed, and culture manipulations can be automated using fluid-handling robotics. Because microfluidics can deal with small number of cells, the characteristics of cellular structure and function and the microenvironment of the stem cells can be understood in a more precise manner. The miniaturization of cell culture platforms allows the observation of cellular behaviour at the scale found in living systems.

Networked Labs-on-a-Chip (NLoC): Introducing networking technologies in microfluidic systems

Microfluidics is a science and a technology which deals with manipulation and control of small volumes of fluids flowing in channels of micro-scale size. It is currently used for Labs-On-a-Chip (LoCs) applications mainly. In this context, recently fluids have been used in the discrete form of droplets or bubbles dispersed into another immiscible fluid. In this case, droplets or bubbles can be exploited as a means to transport digital information between microfluidic components, with sequences of particles (i.e. droplets or bubbles) representing sequences of binary values.LoCs are today realized through monolithic devices in which samples are processed by passing them through a predetermined sequence of elements connected by fixed and preconfigured microfluidic channels. To increase the reusability of LoCs, effectiveness and flexibility, networking functionalities can be introduced so that the sequence of elements involved in the processing can be dynamically selected. Accordingly, in this paper we introduce the Networked LoC (NLoC) paradigm that brings networking concepts and solutions into microfluidic systems such as LoCs. More specifically, in this paper the need for the introduction of the NLoC paradigm is motivated, its required functions are identified, a system architecture is proposed, and the related physical level design aspects, such as channel characterization, information representation and information capacity are investigated.

Estimating the requirement for manipulation of medicines to provide accurate doses for children

ObjectiveTo determine the type and frequency of manipulations of drug dosage forms required to administer smaller doses for children and the drugs involved.MethodsAn experienced paediatric clinical pharmacist estimated the requirement...

Elucidating drug resistance properties in scarce cancer stem cells using droplet microarray

Summary The screening and characterization of cancer stem cells (CSCs) has been challenging due to sample scarcity. We have developed a miniaturized high-content screening (HCS) assay platform to study intra-cellular proteins related to the survival and apoptosis of CSCs with chemotherapeutic treatment. By overcoming critical bottlenecks associated with sample scarcity, we are able to elucidate the drug responses of the side-population (SP) phenotype characteristics of CSCs. This successful miniaturization of HCS assays facilitates the development of cancer drug treatments, and paves the way for nanoliter volume manipulation for cell-based studies and screening.

Effects of tap water, electrolyte solution, and spontaneous and furosemide-stimulated urinary excretion on thirst

To contrast the effects of various modifications of body fluid volumes on thirst as reported by healthy volunteers. Ten male volunteers aged between 19 and 37 years (mean 22 years) underwent four experiments each, which comprised infusion of 400-800 mL of acetated Ringer's solution and intake of 600 mL of tap water. Half of the experiments were preceded by volume depletion (median 1.7 L) with furosemide. A visual analogue scale (0-100 mm) was used to assess perceived thirst during each experiment. Volume depletion (P < 0.001) and tap water (P < 0.03) both affected thirst by 13 mm per L of fluid, whereas spontaneous diuresis and infusion of Ringer's acetate did not significantly change the thirst rating (multiple regressions). More detailed analyses showed that the volume depletion increased the median (25th-75th percentiles) thirst rating from 28 mm (21-43) to 59 mm (46-72, P < 0.001) while no change occurred in those who were only slightly thirsty (< 30 mm) before the volume depletion began. Ringer's solution alleviated thirst in those who were very thirsty, but tended to increase thirst in the volunteers who were not thirsty before the infusion. Similarly, hydration with tap water decreased thirst (by 24 mm, P < 0.04) in those who were thirsty (> 60 mm) while the others reported no change. The change in thirst rating during volume depletion, administration of Ringer's acetate, and ingestion of tap water were all dependent on the thirst rating obtained when the manipulation of the body fluid volume was initiated.

1P1-V09 空気圧駆動マイクロ分注チップによる分配操作の検証(ナノ・マイクロ流体システム)

The pneumatic micro dispenser chip that can divide liquids into 10nL each has been developed successfully. From the dispensing experimental result, it was difficult to supply the divided liquid properly to the channel (reactor) selected among branched channels. Therefore, we found out that the issue was caused by the air compression in the micro channel. The design of the dispenser chip to supply the divided liquid properly to the reactor was improved. The experimental result provided us the effectiveness of the improvement. The micro dispenser chip with manipulation of nanoliter volume is useful for portable health care devices.

P-G1-11 多分岐分配可能な空気圧駆動マイクロ分注チップの開発(P-G1 マイクロ熱流体,ポスターセッション論文)

We verified about the multiple distribution method to supply the divided sample to the channel selected among the branched channels. The pneumatic micro dispenser chip that can divide liquids into 10nL each has been developed successfully. From the dispensing experimental result, the problem that it is difficult to supply the divided liquid properly to the channel (reactor) selected among branched channels has occurred. Therefore, we investigated that the issue was caused by the air compression in the micro channel and The dispenser chip was improved in order to supply the divided liquid properly to micro channel. The experimental result using improved chip provided us the effectiveness of the improvement. The micro dispenser chip with manipulation of nanoliter volume is useful for portable health care devices.

WPS orchestration using the Taverna workbench: The eScience approach

eScience is an umbrella concept which covers internet technologies, such as web service orchestration that involves manipulation and processing of high volumes of data, using simple and efficient methodologies. This concept is normally associated with bioinformatics, but nothing prevents the use of an identical approach for geoinfomatics and OGC (Open Geospatial Consortium) web services like WPS (Web Processing Service).In this paper we present an extended WPS implementation based on the PyWPS framework using an automatically generated WSDL (Web Service Description Language) XML document that replicates the WPS input/output document structure used during an Execute request to a server. Services are accessed using a modified SOAP (Simple Object Access Protocol) interface provided by PyWPS, that uses service and input/outputs identifiers as element names. The WSDL XML document is dynamically generated by applying XSLT (Extensible Stylesheet Language Transformation) to the getCapabilities XML document that is generated by PyWPS.The availability of the SOAP interface and WSDL description allows WPS instances to be accessible to workflow development software like Taverna, enabling users to build complex workflows using web services represented by interconnecting graphics. Taverna will transform the visual representation of the workflow into a SCUFL (Simple Conceptual Unified Flow Language) based XML document that can be run internally or sent to a Taverna orchestration server. SCUFL uses a dataflow-centric orchestration model as opposed to the more commonly used orchestration language BPEL (Business Process Execution Language) which is process-centric.

Phosphodiesterase 4 inhibition attenuates plasma volume loss and transvascular exchange in volume expanded mice

Phosphodiesterase 4 inhibition attenuates plasma volume loss and transvascular exchange in volume expanded mice

English

19F NMR provided a highly specific tool for identification of efavirenz in human serum and pharmaceutical preparations as well as a suitable analytical technique for their absolute quantification. The method is based on the integration of appropriate signals of efavirenz and potassium fluoride, as an internal standard. The proposed method is simple and reliable, but when it is used without any sample pretreatment, there is a manipulation of large sample volumes and lengthy analysis time. The calibration curve for efavirenz in human serum was linear over the range of 0.8 to 1000 mgL&minus;1, with detection limit of 0.3ï€ mgL&minus;1. The mean error on human serum samples ranged from about -4 to -6%, with relative standard deviations of &lt;8%. The method was also applied successfully for the determination of efavirenz in real pharmaceutical samples,and compared with the results obtained by a reference high-performance liquid chromatography-ultraviolet (HPLC-UV) method. &nbsp; Key words:&nbsp;Efavirenz,&nbsp;19F NMR analyses, HIV, serum, pharmaceuticals.

Sensitivity of USPIO‐enhanced R2 imaging to dynamic blood volume changes in the rat kidney

To determine whether MRI in combination with an intravascular contrast agent is sensitive to pharmacologically induced vasodilation and vasoconstriction in the rat kidney. R(2) imaging was performed in 25 Sprague Dawley rats at 3 Tesla in the presence of ferumoxytol, an ultrasmall superparamagnetic iron oxide (USPIO) agent with a long plasma half-life. R(2) changes were measured following manipulation of blood volume by intravenous administration of adenosine, a short-acting vasodilator, or N(G)-nitro-L-arginine methyl ester (L-NAME), a long-acting nitric oxide synthase inhibitor with known vasoconstrictive effects. As a control, R(2) responses to adenosine and L-NAME were also examined in the absence of ferumoxytol. In the presence of ferumoxytol, adenosine induced a significant increase in R(2), while L-NAME produced a reduction, although the latter was not statistically significant. Control experiments revealed small R(2) changes in the absence of ferumoxytol. An incidental finding was that the cross-sectional area of the kidney also varied dynamically with adenosine and L-NAME. Our results suggest that ferumoxytol-enhanced R(2) imaging is sensitive to adenosine-induced vasodilation. The responses to L-NAME, however, were not statistically significant. The variations in kidney size and the R(2) changes in the absence of ferumoxytol may reflect alterations in the volume of the renal tubules.

Benefits of a Systematic Approach in the Evaluation of Fetal Facial 3-Dimensional Volumes

The purpose of our study was to evaluate the accuracy and efficacy of using a systematic approach to teach maternal-fetal medicine physicians how to display a diagnostic fetal profile and palate using 3-dimensional ultrasonography (3DUS). Ten maternal-fetal medicine physicians were randomly assigned to 2 groups, A and B, and instructed on basic principles of 3DUS volume manipulation. Physicians in group A were asked to display the fetal profile in 5 volumes, including 1 fetus with abnormalities. Physicians in Group B were asked to display the fetal profile in the same 5 volumes after detailed instruction. The groups were combined, and detailed instruction was repeated. The physicians were asked to review an additional 5 volumes. In a separate session, the physicians were divided into their respective groups, and a similar exercise was repeated. This time, they were asked to display the fetal palate in 3-orthogonal-plane and parallel-plane images. The time required for manipulation was recorded. Images were reviewed for accuracy and clinical utility by 2 blinded experienced sonologists. Data were analyzed with mixed effects models. Fetal profile and parallel-plane palate scores were significantly higher in group B (P < .001) compared to group A. There was no difference between groups in displaying the 3-orthogonal-plane image of the palate or after additional training for either group. The mean times for display did not differ between the groups. The time required for evaluation of the abnormal profiles was longer (P = .02) than that for evaluation of the normal profiles. Detailed instruction in obtaining 3DUS images of fetal profiles and palates improved the image quality obtained by physicians. Teaching physicians in a standardized way may help improve the use of 3DUS in clinical practice.

Factors contributing to the variability observed in duplicate forensic breath alcohol measurement

Several factors contribute to the variability observed among repeated measurements of breath alcohol concentration. Identifying these factors and the magnitude of their contribution is the focus of this study. Large breath alcohol data sets consisting of duplicate test results from drivers arrested for driving while intoxicated were obtained from four jurisdictions: Sweden, Alabama, New Jersey and Washington State. The absolute difference between duplicate results were fitted to a multivariate linear regression model which included the following predictor variables: mean breath alcohol concentration, absolute exhalation time difference between repeated measurements, absolute exhalation volume difference, gender and age. In all data sets considered here, the breath alcohol concentration was the most statistically and practically significant predictor of absolute difference between the duplicate results. The next two most important predictors to enter models for all jurisdictions were exhalation volume difference and exhalation time difference. The maximum multivariate R2 for any jurisdiction, however, was only 0.24, suggesting that other factors not considered here may be of importance. Two predictors over which the subject would have some influence included exhalation time and volume. When these were set at values expected to have maximum impact, the effect on duplicate test differences was very small, 0.008 g/210 L or less in all jurisdictions, indicating that subject manipulation of exhalation time and volume would have at most a very small systematic effect on estimated breath alcohol concentration. This study presents multivariate models useful for identifying the impact of five variables that may influence breath test variability.

Manipulation of cell volume and membrane pore comparison following single cell permeabilization with 60- and 600-ns electric pulses

Intense nanosecond-duration electric pulses (nsEP) open stable nanopores in the cell membrane, followed by cell volume changes due to water uptake or expulsion, as regulated by the osmolality balance of pore-impermeable solutes inside and outside the cell. The size of pores opened by either fifty 60-ns EP (~13 kV/cm) or five, 600-ns EP (~6 kV/cm) in GH3 cells was estimated by isoosmotic replacement of bath NaCl with polyethylene glycols and sugars. Such replacement reduced cell swelling or resulted in transient or sustained cell shrinking in response to EP. depending on the availability of pores permeable to the test solute. Unexpectedly, solute substitutions showed that for the same integral area of pores opened by 60- and 600-ns treatments (as estimated by cell volume changes), the pore sizes were similar. However, the 600-ns exposure triggered significantly higher cell uptake of propidium. We concluded that 600-ns EP opened a greater number of larger (propidium-permeable pores), but the fraction of the larger pores in the entire pore population was insufficient to contribute to cell volume changes. For both the 60- and 600-ns exposures, cell volume changes were determined by pores smaller than 0.9 nm in diameter; however, the diameter increased with increasing the nsEP intensity.

P08.03: Detection of the ‘3VT view’ using 3D ultrasound volumes acquired at the level of the ‘4CV’

Objectives: The four-chamber view (4CV) detects about 30% of major cardiac anomalies. Adding the outflow tract and the three-vessel trachea view (3VT) improve the detection of cardiac anomalies. 3-Dimensional ultrasound (3DUS) is more available than 4-Dimensional ultrasound for cardiac examinations. The aim of this study is to investigate the ability to demonstration of the 3VT of the fetal heart with 3DUS, and to test the reliability of the measurements of the arches. Methods: Prospective study of normal fetal heart volumes, acquired at the second trimester of gestation by 3DUS with color Doppler. Post processing off line manipulation of the volumes to demonstrate the 3VT view by two expert sonologists. The ‘V’ shape of the arches, the color of flow and the place of the trachea and superior vena cava were evaluated. Measurements of the aorticand ductal-arch diameter were calculated and compared to the value from literature of 2-Dimension ultrasound. Intraand inter-observer variability was calculated. Results: 31 healthy patients with normal fetuses by anomaly scan were evaluated prospectively. Mean gestational age was 22w6d (range 19w4d–25w0d). Navigation in the cephalic direction revealed the 3VT view in 87–90% by the two reviewers. Mean and 95CI diameter of the aortic and pulmonary arteries are presented in Table 1. The estimated time for volume acquisition and manipulation in the A plane is about 60 seconds. Conclusions: Combination of basic knowledge of 3DUS and demonstration of 4CV allows extension of the cardiac examination to the 3VT view in about 90% of cases. Information of the number of vessels, shape, diameter, flow direction and the relation of the two arches is collected with simple sonographic method.

Basic as well as detailed neurosonograms can be performed by offline analysis of three‐dimensional fetal brain volumes

To evaluate the feasibility and the processing time of offline analysis of three-dimensional (3D) brain volumes to perform a basic, as well as a detailed, targeted, fetal neurosonogram. 3D fetal brain volumes were obtained in 103 consecutive healthy fetuses that underwent routine anatomical survey at 20-23 postmenstrual weeks. Transabdominal gray-scale and power Doppler volumes of the fetal brain were acquired by one of three experienced sonographers (an average of seven volumes per fetus). Acquisition was first attempted in the sagittal and coronal planes. When the fetal position did not enable easy and rapid access to these planes, axial acquisition at the level of the biparietal diameter was performed. Offline analysis of each volume was performed by two of the authors in a blinded manner. A systematic technique of 'volume manipulation' was used to identify a list of 25 brain dimensions/structures comprising a complete basic evaluation, intracranial biometry and a detailed targeted fetal neurosonogram. The feasibility and reproducibility of obtaining diagnostic-quality images of the different structures was evaluated, and processing times were recorded, by the two examiners. Diagnostic-quality visualization was feasible in all of the 25 structures, with an excellent visualization rate (85-100%) reported in 18 structures, a good visualization rate (69-97%) reported in five structures and a low visualization rate (38-54%) reported in two structures, by the two examiners. An average of 4.3 and 5.4 volumes were used to complete the examination by the two examiners, with a mean processing time of 7.2 and 8.8 minutes, respectively. The overall agreement rate for diagnostic visualization of the different brain structures between the two examiners was 89.9%, with a kappa coefficient of 0.5 (P < 0.001). In experienced hands, offline analysis of 3D brain volumes is a reproducible modality that can identify all structures necessary to complete both a basic and a detailed second-trimester fetal neurosonogram.

Background-incorporated volumetric model for patient-specific surgical simulation: a segmentation-free, modeling-free framework

Patient-specific surgical simulation imposes both practical and technical challenges. We propose a segmentation-free, modeling-free framework that creates medical volumetric models for intuitive volume deformation and manipulation in patient-specific surgical simulation. The proposed framework creates a volumetric model based upon a new form of mesh structure, a Volume Proxy Mesh (VPM). The model can be generated in two phases: the vertex placement phase and mesh improvement phase. Vertices of a VPM are assigned to an initial location by curvature-based vertex placement method, and followed by mesh improvement performed by Particle Swarm Optimization (PSO). The framework is applied to several kidney CT volume data. Using the framework, the resulting models are closely tailored to the detailed features of the datasets. Moreover, the resulting VPM meshes can support broader spectrum deformation between the manipulated organ and its surrounding tissues. Progress in the mesh quality of the final mesh also shows that PSO is feasible for mesh improvement. The framework was applied to several kidney CT volume datasets. Using the framework, the resulting models are closely tailored to the detailed features of the datasets. Moreover, the resulting VPM meshes can support broader spectrum deformation between the manipulated organ and its surrounding tissues. Evaluation of final mesh quality shows that PSO is feasible for mesh improvement.

Constrained illustrative volume deformation

Interactive volume deformation has received a lot of attention recently thanks to the advances of graphics processing units. The ability to transform volumetric objects constitutes an essential tool for generating illustrative visualizations. Previous approaches to this problem have adapted techniques used for surface meshes and applied it to an embedding mesh. This method, however, often results in low quality due to the resolution of the mesh. Other alternatives consider the volume as a homogeneous collection of points, and therefore, cannot simulate physical laws that govern the deformation of different materials. In this paper, we aim at obtaining high-quality illustrations of deformable volumes that mimic physically inspired constraints. For example, although skin and muscle can be illustrated as deforming elastically, bone tissue should move rigidly. Here, we show that we can obtain constrained illustrative deformations with algebraic operations on displacement maps. Through a number of examples, we show that this is a faster alternative to costly physical simulations, with wide applications in computer-aided medical illustration, interactive volume manipulation and data exploration.