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This page shows you the most recent publications within this specialty of the MedWorm directory. This is page number 40.

The effect of microvascular pattern alterations on network resistance in spontaneously hypertensive rats
The objectives of this study were to determine whether microvascular rarefaction is associated with other network pattern alterations and to evaluate whether pattern alterations in hypertension necessarily contribute to increased microvascular resistance. Mesenteric tissues from age-matched (15–16 weeks) male spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) rats were harvested and immunolabeled for PECAM. SHR networks displayed a decreased microvascular area, arteriolar-venular (AV) length, number of AV branches, and number of capillary segments. In addition, SHR networks displayed incr...
Source: Medical and Biological Engineering and Computing - May 5, 2012 Category: Biomedical Engineering Tags: Medical and Biological Engineering and Computing Source Type: research

Ultrasound Imaging of Oxidative Stress In Vivo with Chemically-Generated Gas Microbubbles.
Abstract Ultrasound contrast agents (UCAs) have tremendous potential for in vivo molecular imaging because of their high sensitivity. However, the diagnostic potential of UCAs has been difficult to exploit because current UCAs are based on pre-formed microbubbles, which can only detect cell surface receptors. Here, we demonstrate that chemical reactions that generate gas forming molecules can be used to perform molecular imaging by ultrasound in vivo. This new approach was demonstrated by imaging reactive oxygen species in vivo with allylhydrazine, a liquid compound that is converted into nitrogen and propylene gas...
Source: Annals of Biomedical Engineering - May 5, 2012 Category: Biomedical Engineering Authors: Perng JK, Lee S, Kundu K, Caskey CF, Knight SF, Satir S, Ferrara KW, Taylor WR, Degertekin FL, Sorescu D, Murthy N Tags: Ann Biomed Eng Source Type: research

Characteristics of flux and gel layer on microfilter and non-woven fabric filter surface based on anoxic-aerobic MBRs.
Abstract Non-woven fabric filter- (NWFF) and microfilter-MBR modules were made using 100 μm polypropylene and 0.25 μm polyethylene materials, respectively. The performances and mechanisms of the two processes were investigated, including additional batch filtration tests to find the function of the dynamic gel layer on the membrane surface. The HRT of both MBRs was 9 h and the operating permeate flux was 13 L/m(2)/h. The two MBRs consisted of an anoxic and aerobic reactor. The NWFF or microfilter (MF) was submerged in each of the aerobic reactors. The two MBRs showed similar performances for the removal of or...
Source: Bioprocess and Biosystems Engineering - May 5, 2012 Category: Biomedical Engineering Authors: Lee JY, Choi BK, Ahn KH, Maeng SK, Song KG Tags: Bioprocess Biosyst Eng Source Type: research

Aerobic granulation and nitrogen removal with the effluent of internal circulation reactor in start-up of a pilot-scale sequencing batch reactor.
Abstract Aerobic granular sludge was successfully cultivated with the effluent of internal circulation (IC) reactor in a pilot-scale sequencing batch reactor (SBR) using activated sludge as seeding sludge. N removal was investigated in the start-up of aerobic granulation process. Initially, the phenomenon of partial nitrification was observed and nitrite accumulation rates (NO(2) (-)-N/NO (x) (-) -N) were between 84.6 and 99.1 %. It was potentially caused by ammonium oxidizing bacteria (AOB) in the seeding activated sludge, high external environmental temperature (~32 °C) and free ammonia (FA) concentration. Aft...
Source: Bioprocess and Biosystems Engineering - May 5, 2012 Category: Biomedical Engineering Authors: Wei D, Si W, Zhang Y, Qiao Z, Yao Z, Zhao W, Zhao J, Chen G, Wei Q, Du B Tags: Bioprocess Biosyst Eng Source Type: research

Improvement of Photorhabdus temperata strain K122 bioinsecticide production by batch and fed-batch fermentations optimization.
Abstract Optimization of a fermentation process for bioinsecticides production by Photorhabdus temperata strain K122 was investigated into fully controlled 3-L fermenter using an optimized medium (OM). Development of large-scale inocula showed that the composition of the growth medium greatly influenced the physiological state of P. temperata cells. The effect of pH, agitation and dissolved oxygen concentration (DO) on the growth, culturability and oral toxicity of P. temperata cells were also investigated. Indeed, maintaining the pH at 7 and controlling DO concentration at 50 % saturation throughout the fermentat...
Source: Bioprocess and Biosystems Engineering - May 5, 2012 Category: Biomedical Engineering Authors: Jallouli W, Jaoua S, Zouari N Tags: Bioprocess Biosyst Eng Source Type: research

Isolation of enantioselective α-hydroxyacid dehydrogenases based on a high-throughput screening method.
Abstract To isolate enantioselective α-hydroxyacid dehydrogenases (α-HADHs), a high-throughput screening method was established. 2,4-Dinitrophenylhydrazine solution forms a red-brown complex with ketoacid produced during the α-HADH-mediated oxidation of α-hydroxyacid. The complex can be easily quantified by spectrophotometric measurement at 458 nm. The enantioselectivity of α-HADH in each strain can be measured with this colorimetric method using (R)- and (S)-α-hydroxyacid concurrently as substrates to evaluate the apparent enantioselectivity (E (app)). The E (app) closely matches the value of true enantiose...
Source: Bioprocess and Biosystems Engineering - May 5, 2012 Category: Biomedical Engineering Authors: Xue YP, Wang W, Wang YJ, Liu ZQ, Zheng YG, Shen YC Tags: Bioprocess Biosyst Eng Source Type: research

Investigation of photoplethysmographic signals and blood oxygen saturation values on healthy volunteers during cuff-induced hypoperfusion using a multimode PPG/SpO2 sensor
Abstract Photoplethysmography (PPG) is a technique widely used to monitor volumetric blood changes induced by cardiac pulsations. Pulse oximetry uses the technique of PPG to estimate arterial oxygen saturation values ( SpO2 ). In poorly perfused tissues, SpO2 readings may be compromised due to the poor quality of the PPG signals. A multimode finger PPG probe that operates simultaneously in reflectance, transmittance and a combined mode called “transreflectance” was developed, in an effort to improve the quality of the PPG signals in states of hypoperfusion. Experiments on 20 volunteers were conducted ...
Source: Medical and Biological Engineering and Computing - May 4, 2012 Category: Biomedical Engineering Tags: Medical and Biological Engineering and Computing Source Type: research

Synthesis of a Novel l-Methyl-Methionine–ICG-Der-02 Fluorescent Probe for In Vivo Near Infrared Imaging of Tumors
Conclusion Met–ICG-Der-02 probe is a promising optical imaging agent for tumor diagnosis, especially in their early stage. Content Type Journal ArticleCategory Research ArticlePages 1-9DOI 10.1007/s11307-012-0560-4Authors Didel M. Mahounga, Department of Biomedical Engineering, School of Life Science and Technology, China Pharmaceutical University, Nanjing, 210009 ChinaLingling Shan, Department of Biomedical Engineering, School of Life Science and Technology, China Pharmaceutical University, Nanjing, 210009 ChinaCao Jie, Department of Biomedical Engineering, School of Life Science and Technology, Chin...
Source: Molecular Imaging and Biology - May 3, 2012 Category: Molecular Biology Tags: Molecular Imaging and Biology Source Type: research

Osteocyte Signaling in Bone
Abstract Osteocytes, the cells residing within the bone matrix and comprising 90 % to 95 % of the all bone cells, have long been considered quiescent bystander cells compared to the osteoblasts and osteoclasts whose activities cause bone gain and loss, and whose dysfunction lead to growth defects and osteoporosis. However, recent studies show that osteocytes play a crucial, central role in regulating the dynamic nature of bone in all its diverse functions. Osteocytes are now known to be the principal sensors for mechanical loading of bone. They produce the soluble factors that regulate the onset of...
Source: Current Osteoporosis Reports - May 3, 2012 Category: Orthopaedics Tags: Current Osteoporosis Reports Source Type: research

Flow-gated radial phase-contrast imaging in the presence of weak flow
Abstract To implement a flow-gating method to acquire phase-contrast (PC) images of carotid arteries without use of an electrocardiography (ECG) signal to synchronize the acquisition of imaging data with pulsatile arterial flow. The flow-gating method was realized through radial scanning and sophisticated post-processing methods including downsampling, complex difference, and correlation analysis to improve the evaluation of flow-gating times in radial phase-contrast scans. Quantitatively comparable results (R = 0.92–0.96, n = 9) of flow-related parameters, including mean velocity, mean...
Source: The International Journal of Cardiovascular Imaging - May 3, 2012 Category: Radiology Tags: The International Journal of Cardiovascular Imaging (formerly Cardiac Imaging) Source Type: research

A combined numerical and experimental technique for estimation of the forces and moments in the lumbar intervertebral disc.
In this study, we proposed a new technique to estimate in vivo loads in the IVD using a subject-specific finite element (FE) model of the disc and the kinematics of the disc endplates as input boundary conditions. The technique was validated by comparing the forces and moments in the discs calculated from the FE analyses to the in vitro experiment measurements of three corresponding lumbar discs. The results showed that the forces and moments could be estimated within an average error of 20%. Therefore, this technique can be a promising tool for non-invasive estimation of the loads in the discs and may be extended to be us...
Source: Computer Methods in Biomechanics and Biomedical Engineering - May 3, 2012 Category: Biomedical Engineering Authors: Wang S, Park WM, Gadikota HR, Miao J, Kim YH, Wood KB, Li G Tags: Comput Methods Biomech Biomed Engin Source Type: research

Patient-specific simulation of a stentless aortic valve implant: the impact of fibres on leaflet performance.
Abstract In some cases of aortic valve leaflet disease, the implant of a stentless biological prosthesis represents an excellent option for aortic valve replacement (AVR). In particular, if compared with the implant of mechanical valves, it provides a more physiological haemodynamic performance and a reduced thrombogeneticity, avoiding the use of anticoagulants. The clinical outcomes of AVR are strongly dependent on an appropriate choice of both prosthesis size and replacement technique, which is, at present, strictly related to surgeon's experience and skill. This represents the motivation for patient-specific fin...
Source: Computer Methods in Biomechanics and Biomedical Engineering - May 3, 2012 Category: Biomedical Engineering Authors: Auricchio F, Conti M, Ferrara A, Morganti S, Reali A Tags: Comput Methods Biomech Biomed Engin Source Type: research

Numerical simulation of the insertion process of an uncemented hip prosthesis in order to evaluate the influence of residual stress and contact distribution on the stem initial stability.
This study evaluates the influence of stem geometry and fitting conditions on the evolution and distribution of the bone-stem contact, stress and strain during and after the hip stem insertion, by means of dynamic finite element techniques. Next, the influence of the mechanical state (bone-stem contact, stress and strain) resulted from the insertion process on the stem initial resistance to subsidence is investigated. In addition, a study on the influence of bone-stem interface conditions (friction) on the insertion process and on the initial stem stability under physiological loading is performed. The results indicate tha...
Source: Computer Methods in Biomechanics and Biomedical Engineering - May 1, 2012 Category: Biomedical Engineering Authors: Monea AG, Pastrav LC, Mulier M, Van der Perre G, Jaecques SV Tags: Comput Methods Biomech Biomed Engin Source Type: research

A computational model to describe the collagen orientation in statically cultured engineered tissues.
Abstract Collagen provides cardiovascular tissues with the ability to withstand haemodynamic loads. A similar network is essential to obtain in tissue-engineered (TE) samples of the same nature. Yet, the mechanism of collagen orientation is not fully understood. Typically collagen remodelling is linked to mechanical loading. However, TE constructs also show an oriented collagen network when developed under static culture. Experiments under these conditions also indicate that the tissue gradually compacts due to contractile stresses developed in the α-actin fibres of the cells. Therefore, it is hypothesised that ce...
Source: Computer Methods in Biomechanics and Biomedical Engineering - May 1, 2012 Category: Biomedical Engineering Authors: Soares AL, Oomens CW, Baaijens FP Tags: Comput Methods Biomech Biomed Engin Source Type: research

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Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

IEEE Transactions on Medical Imaging information for authors
Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

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Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

Acceleration of Optoacoustic Model-Based Reconstruction Using Angular Image Discretization
Optoacoustic tomography has recently demonstrated powerful performance in small animal imaging and initial clinical trials in terms of the high spatial resolution, versatile contrast, and dynamic imaging capabilities it can provide. Yet, the current optoacoustic image reconstruction methods are usually based on inaccurate forward modelling approaches or otherwise demand a high computational cost, which imposes certain practical limitations and hinders image quantification. Herein, we introduce a new method for accelerating optoacoustic reconstructions, based on angular image discretization of the forward model solution. Th...
Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

Seeing Is Believing: Video Classification for Computed Tomographic Colonography Using Multiple-Instance Learning
In this paper, we present development and testing results for a novel colonic polyp classification method for use as part of a computed tomographic colonography (CTC) computer-aided detection (CAD) system. Inspired by the interpretative methodology of radiologists using 3-D fly-through mode in CTC reading, we have developed an algorithm which utilizes sequences of images (referred to here as videos) for classification of CAD marks. For each CAD mark, we created a video composed of a series of intraluminal, volume-rendered images visualizing the detection from multiple viewpoints. We then framed the video classification que...
Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

JointMMCC: Joint Maximum-Margin Classification and Clustering of Imaging Data
We describe a joint maximum-margin classification and clustering (JointMMCC) approach that jointly detects the pathologic population via semi-supervised classification, as well as disentangles heterogeneity of the pathological cohort by solving a clustering subproblem. We propose an efficient solution to the nonconvex optimization problem associated with JointMMCC. We apply our proposed approach to an medical resonance imaging study of aging, and identify coherent subpopulations (i.e., clusters) of cognitively less stable adults.
Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

Modeling Brain Activation in fMRI Using Group MRF
Noise confounds present serious complications to functional magnetic resonance imaging (fMRI) analysis. The amount of discernible signals within a single dataset of a subject is often inadequate to obtain satisfactory intra-subject activation detection. To remedy this limitation, we propose a novel group Markov random field (GMRF) that extends each subject's neighborhood system to other subjects to enable information coalescing. A distinct advantage of GMRF over standard fMRI group analysis is that no stringent one-to-one voxel correspondence is required. Instead, intra- and inter-subject neighboring voxels are jointly reg...
Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

TwinMARM: Two-Stage Multiscale Adaptive Regression Methods for Twin Neuroimaging Data
Twin imaging studies have been valuable for understanding the relative contribution of the environment and genes on brain structures and their functions. Conventional analyses of twin imaging data include three sequential steps: spatially smoothing imaging data, independently fitting a structural equation model at each voxel, and finally correcting for multiple comparisons. However, conventional analyses are limited due to the same amount of smoothing throughout the whole image, the arbitrary choice of smoothing extent, and the decreased power in detecting environmental and genetic effects introduced by smoothing raw image...
Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

Closed-Form Inverse Kinematics for Interventional C-Arm X-Ray Imaging With Six Degrees of Freedom: Modeling and Application
For trauma and orthopedic surgery, maneuvering a mobile C-arm fluoroscope into a desired position to acquire an X-ray is a routine surgical task. The precision and ease of use of the C-arm becomes even more important for advanced interventional imaging techniques such as parallax-free X-ray image stitching. Today's standard mobile C-arms have been modeled with only five degrees of freedom (DOF), which definitely restricts their motions in 3-D Cartesian space. In this paper, we present a method to model both the mobile C-arm and patient's table as an integrated kinematic chain having six DOF without constraining table posit...
Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

Projection X-Space Magnetic Particle Imaging
Projection magnetic particle imaging (MPI) can improve imaging speed by over 100-fold over traditional 3-D MPI. In this work, we derive the 2-D x-space signal equation, 2-D image equation, and introduce the concept of signal fading and resolution loss for a projection MPI imager. We then describe the design and construction of an x-space projection MPI scanner with a field gradient of 2.35 T/m across a 10 cm magnet free bore. The system has an expected resolution of 3.5 $times$ 8.0 mm using Resovist tracer, and an experimental resolution of 3.8 $times$ 8.4 mm resolution. The system images 2.5 cm $times$ 5.0 cm partial fiel...
Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

A Multistage Discriminative Model for Tumor and Lymph Node Detection in Thoracic Images
Analysis of primary lung tumors and disease in regional lymph nodes is important for lung cancer staging, and an automated system that can detect both types of abnormalities will be helpful for clinical routine. In this paper, we present a new method to automatically detect both tumors and abnormal lymph nodes simultaneously from positron emission tomography—computed tomography thoracic images. We perform the detection in a multistage approach, by first detecting all potential abnormalities, then differentiate between tumors and lymph nodes, and finally refine the detected tumors for false positive reduction. Each s...
Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

Image-Based Estimation of Ventricular Fiber Orientations for Personalized Modeling of Cardiac Electrophysiology
The objective of this project was to develop a methodology to estimate cardiac fiber orientations from in vivo images of patient heart geometries. An accurate representation of ventricular geometry and fiber orientations was reconstructed, respectively, from high-resolution ex vivo structural magnetic resonance (MR) and diffusion tensor (DT) MR images of a normal human heart, referred to as the atlas. Ventricular geometry of a patient heart was extracted, via semiautomatic segmentation, from an in vivo computed tomography (CT) image. Using image transformation algorithms, the atlas ventricular geometry was deformed to matc...
Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

An Efficient Interlaced Multi-Shell Sampling Scheme for Reconstruction of Diffusion Propagators
In this paper, we propose an interlaced multi-shell sampling scheme for the reconstruction of the diffusion propagator from diffusion weighted magnetic resonance imaging (DW-MRI). In standard multi-shell sampling schemes, sample points are uniformly distributed on several spherical shells in $ {bf q}$-space. The distribution of sample points is the same for all shells, and is determined by the vertices of a selected polyhedron. We propose a more efficient interlaced scheme where sample points are different on alternating shells and are determined by the vertices of a pair of dual polyhedra. Since it samples more directions...
Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

Computer-Aided Lesion Diagnosis in Automated 3-D Breast Ultrasound Using Coronal Spiculation
A computer-aided diagnosis (CAD) system for the classification of lesions as malignant or benign in automated 3-D breast ultrasound (ABUS) images, is presented. Lesions are automatically segmented when a seed point is provided, using dynamic programming in combination with a spiral scanning technique. A novel aspect of ABUS imaging is the presence of spiculation patterns in coronal planes perpendicular to the transducer. Spiculation patterns are characteristic for malignant lesions. Therefore, we compute spiculation features and combine them with features related to echotexture, echogenicity, shape, posterior acoustic beha...
Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

Diffeomorphic Metric Mapping of High Angular Resolution Diffusion Imaging Based on Riemannian Structure of Orientation Distribution Functions
In this paper, we propose a novel large deformation diffeomorphic registration algorithm to align high angular resolution diffusion images (HARDI) characterized by orientation distribution functions (ODFs). Our proposed algorithm seeks an optimal diffeomorphism of large deformation between two ODF fields in a spatial volume domain and at the same time, locally reorients an ODF in a manner such that it remains consistent with the surrounding anatomical structure. To this end, we first review the Riemannian manifold of ODFs. We then define the reorientation of an ODF when an affine transformation is applied and subsequently,...
Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

Tracking Monotonically Advancing Boundaries in Image Sequences Using Graph Cuts and Recursive Kernel Shape Priors
We introduce a probabilistic computer vision technique to track monotonically advancing boundaries of objects within image sequences. Our method incorporates a novel technique for including statistical prior shape information into graph-cut based segmentation, with the aid of a majorization–minimization algorithm. Extension of segmentation from single images to image sequences then follows naturally using sequential Bayesian estimation. Our methodology is applied to two unrelated sets of real biomedical imaging data, and a set of synthetic images. Our results are shown to be superior to manual segmentation.
Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

Advanced Three-Dimensional Tailored RF Pulse Design in Volume Selective Parallel Excitation
Volume selective excitation has a variety of uses in clinical magnetic resonance imaging, but can suffer from insufficient excitation accuracy and impractically long pulse duration in ultra-high field applications. Based on recently-developed parallel transmission techniques, an optimized 3D tailored radio-frequency RF (TRF) pulse, designed with a novel 3D adaptive trajectory, is proposed to improve and accelerate volume selective excitation. The trajectory is designed to be regular-shaped and adaptively stretched according to the size of a 3D k-space “trajectory container.” The container is designed to hold ...
Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

IEEE Transactions on Medical Imaging publication information
Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

Table of Contents
Source: IEE Transactions on Medical Imaging - May 1, 2012 Category: Biomedical Engineering Source Type: research

Influence of gaseous VOC concentration on the diversity and biodegradation performance of microbial communities.
Abstract In this work, the influence of toluene gas concentration on the isolation of toluene degrading microbial communities from activated sludge was studied. Toluene biodegradation at gas phase concentration of 10 g m(-3) (R1) resulted in process instability with removal efficiencies (RE) lesser than 33 %, while operation at toluene gas phase concentrations of 300 mg m(-3) (R2) and 11 mg m(-3) (R3) was stable with RE ranging from 74 to 94 %. The consortium isolated in R1 exhibited the highest tolerance toward toluene but the lowest biodegradation performance at trace level VOC concentrations. Despite R2 ...
Source: Bioprocess and Biosystems Engineering - May 1, 2012 Category: Biomedical Engineering Authors: Estrada JM, Rodríguez E, Quijano G, Muñoz R Tags: Bioprocess Biosyst Eng Source Type: research

Prospects of implant with locking plate in fixation of subtrochanteric fracture: experimental demonstration of its potential benefits on synthetic femur model with supportive hierarchical nonlinear hyperelastic finite element analysis
Conclusion: When fixed with the LP implant, the synthetic femur model of the subtrochancteric fracture consistently exceeds in the key biomechanical measures of stability and durability. These capabilities suggest increased resistance to fatigue and failure, which are highly desirable features expected of implants make the LP implant potentially a viable alternative to the conventional ABP or DCSP in the treatment of the subtrochancteric femur fractures for the betterment of the clinical outcome.
Source: BioMedical Engineering OnLine - April 30, 2012 Category: Biomedical Engineering Authors: Hadi LatifiShanmugam RukmanikanthanAzura MansorTunku KamarulMehmet Bilgen Source Type: research

Changing sagittal plane body position during single-leg landings influences the risk of non-contact anterior cruciate ligament injury
Conclusions Leaning forward while landing appears to protect the ACL by increasing the shock absorption capacity and knee flexion angles and decreasing anterior shear force due to the knee joint compression force and quadriceps muscle activation. Conversely, landing upright appears to be ACL harmful by increasing the post-impact force of landing and quadriceps muscle activity while decreasing knee flexion angles, all of which lead to a greater tibial anterior shear force and ACL loading. ACL injury prevention programmes should include exercise regimens to improve sagittal plane body position control during l...
Source: Knee Surgery, Sports Traumatology, Arthroscopy - April 28, 2012 Category: Orthopaedics Tags: Knee Surgery, Sports Traumatology, Arthroscopy Source Type: research

Isobutanol production in engineered Saccharomyces cerevisiae by overexpression of 2-ketoisovalerate decarboxylase and valine biosynthetic enzymes.
In this study, construction of isobutanol production systems was attempted by overexpression of effective 2-keto acid decarboxylase (KDC) and combinatorial overexpression of valine biosynthetic enzymes in S. cerevisiae D452-2. Among the six putative KDC enzymes from various microorganisms, 2-ketoisovalerate decarboxylase (Kivd) from L. lactis subsp. lactis KACC 13877 was identified as the most suitable KDC for isobutanol production in the yeast. Isobutanol production by the engineered S. cerevisiae was assessed in micro-aerobic batch fermentations using glucose as a sole carbon source. 93 mg/L isobutanol was produced in t...
Source: Bioprocess and Biosystems Engineering - April 28, 2012 Category: Biomedical Engineering Authors: Lee WH, Seo SO, Bae YH, Nan H, Jin YS, Seo JH Tags: Bioprocess Biosyst Eng Source Type: research

Isolation of cell nuclei in microchannels by short-term chemical treatment via two-step carrier medium exchange.
We examined several surfactant molecules and demonstrated that Triton X-100 exhibited high efficiency regarding nucleus isolation for both adherent (HeLa) and nonadherent (JM) cells, with a recovery ratio of ∼80 %. In addition, the isolation efficiency was evaluated by western blotting. The presented flow-through microfluidic cell-nucleus separator may be a useful tool for general biological applications, because of its simplicity in operation, high reproducibility, and accuracy. PMID: 22544390 [PubMed - as supplied by publisher]
Source: Biomedical Microdevices - April 28, 2012 Category: Biomedical Engineering Authors: Toyama K, Yamada M, Seki M Tags: Biomed Microdevices Source Type: research

Erratum to “Signal Reconstruction via Sampled-Data Control Theory—Beyond the Shannon Paradigm” [Feb 12 613-625]
In the above titled paper (ibid., vol. 60, no. 2, pp. 613-625, Feb. 2012), due to a production error, Figs. 6-12 and 14-25 were incorrectly printed in black and white when they should have correctly appeared in color. The figures are made available here in color.
Source: IEEE Transactions on Signal Processing - April 27, 2012 Category: Biomedical Engineering Source Type: research

IEEE Transactions on Biomedical Engineering Associate Editors
Source: IEEE Transactions on Biomedical Engineering - April 27, 2012 Category: Biomedical Engineering Source Type: research

IEEE Transactions on Biomedical Engineering information for authors
Source: IEEE Transactions on Biomedical Engineering - April 27, 2012 Category: Biomedical Engineering Source Type: research

Special issue on TBME full papers and TBME letters on surgical robotics
Source: IEEE Transactions on Biomedical Engineering - April 27, 2012 Category: Biomedical Engineering Source Type: research

Real-time Control of Angioplasty Balloon Inflation Based on Feedback from Intravascular Optical Coherence Tomography: Experimental Validation on an Excised Heart and a Beating Heart Model
We report on real-time control of balloon inflation inside porcine arteries. In the first step, experiments were done in a coronary artery of an excised heart. In the second step, experiments were done in a beating heart setup providing conditions very close to in vivo conditions without the complications. A programmable syringe pump was used to inflate a compliant balloon in arteries, while intravascular optical coherence tomography (IVOCT) monitoring was performed. In a feedback loop, IVOCT images were processed to provide the balloon diameter values in real time to control the pump action in order to achieve a target di...
Source: IEEE Transactions on Biomedical Engineering - April 27, 2012 Category: Biomedical Engineering Source Type: research

A Practical Strategy for sEMG-Based Knee Joint Moment Estimation During Gait and Its Validation in Individuals With Cerebral Palsy
Individuals with cerebral palsy have neurological deficits that may interfere with motor function and lead to abnormal walking patterns. It is important to know the joint moment generated by the patient's muscles during walking in order to assist the suboptimal gait patterns. In this paper, we describe a practical strategy for estimating the internal moment of a knee joint from surface electromyography (sEMG) and knee joint angle measurements. This strategy requires only isokinetic knee flexion and extension tests to obtain a relationship between the sEMG and the knee internal moment, and it does not necessitate com...
Source: IEEE Transactions on Biomedical Engineering - April 27, 2012 Category: Biomedical Engineering Source Type: research

CNT/PDMS Composite Flexible Dry Electrodesfor Long-Term ECG Monitoring
We fabricated a carbon nanotube (CNT)/ polydimethylsiloxane (PDMS) composite-based dry ECG electrode that can be readily connected to conventional ECG devices, and showed its long-term wearable monitoring capability and robustness to motion and sweat. While the dispersion of CNTs in PDMS is challenging, we optimized the process to disperse untreated CNTs within PDMS by mechanical force only. The electrical and mechanical characteristics of the CNT/PDMS electrode were tested according to the concentration of CNTs and its thickness. The performances of ECG electrodes were evaluated by using 36 types of electrodes which were ...
Source: IEEE Transactions on Biomedical Engineering - April 27, 2012 Category: Biomedical Engineering Source Type: research

Limitations in the Rapid Extraction of Evoked Potentials Using Parametric Modeling
The rapid extraction of variations in evoked potentials (EPs) is of great clinical importance. Parametric modeling using autoregression with an exogenous input (ARX) and robust evoked potential estimator (REPE) are commonly used methods for extracting EPs over the conventional moving time average. However, a systematic study of the efficacy of these methods, using known synthetic EPs, has not been performed. Therefore, the current study evaluates the restrictions of these methods in the presence of known and systematic variations in EP component latency and signal-to-noise ratios (SNR). In the context of rapid extraction, ...
Source: IEEE Transactions on Biomedical Engineering - April 27, 2012 Category: Biomedical Engineering Source Type: research

Diffuser-Aided Diffuse Optical Imaging for Breast Tumor: A Feasibility Study Based on Time-Resolved Three-Dimensional Monte Carlo Modeling
This study proposed diffuser-aided diffuse optical imaging (DADOI) as a new approach to improve the performance of the conventional diffuse optical tomography (DOT) approach for breast imaging. The 3-D breast model for Monte Carlo simulation is remodeled from clinical MRI image. The modified Beer–Lambert's law is adopted with the DADOI approach to substitute the complex algorithms of inverse problem for mapping of spatial distribution, and the depth information is obtained based on the time-of-flight estimation. The simulation results demonstrate that the time-resolved Monte Carlo method can be capable of per...
Source: IEEE Transactions on Biomedical Engineering - April 27, 2012 Category: Biomedical Engineering Source Type: research

US–Fluoroscopy Registration for Transcatheter Aortic Valve Implantation
In this study, inherent probe tracking performance was assessed, and TEE to fluoroscopy registration accuracy and robustness were evaluated. Results demonstrated probe tracking errors of below 0.6 mm and 0.2 $^circ$, a 2-D RMS registration error of 1.5 mm, and a tracking failure rate of below 1%. In addition to providing live registration and better accuracy and robustness compared to existing TEE probe tracking methods, this system is designed to be suitable for clinical use. It is fully automatic, requires no additional operating room hardware, does not require intraoperative calibration, maintains existing proced...
Source: IEEE Transactions on Biomedical Engineering - April 27, 2012 Category: Biomedical Engineering Source Type: research

Spatial Filtering for Robust Myoelectric Control
Pattern recognition techniques have been applied to extract information from electromyographic (EMG) signals that can be used to control electrical powered hand prostheses. In this paper, optimized spatial filters that enhance separation properties of EMG signals are investigated. In particular, different multiclass extensions of the common spatial patterns algorithm are applied to high-density surface EMG signals acquired from the forearms of ten healthy subjects. Visualization of the obtained filter coefficients provides insight into the physiology of the muscles related to the performed contractions. The CSP methods are...
Source: IEEE Transactions on Biomedical Engineering - April 27, 2012 Category: Biomedical Engineering Source Type: research

Computational Analysis of Contractility in Engineered Heart Tissue
Engineered heart tissue (EHT) is a potential therapy for heart failure and the basis of functional in vitro assays of novel cardiovascular treatments. Self-organizing EHT can be generated in fiber form, which makes the assessment of contractile function convenient with a force transducer. Contractile function is a key parameter of EHT performance. Analysis of EHT force data is often performed manually; however, this approach is time consuming, incomplete and subjective. Therefore, the purpose of this study was to develop a computer algorithm to efficiently and objectively analyze EHT force data. This algorithm incorporates...
Source: IEEE Transactions on Biomedical Engineering - April 27, 2012 Category: Biomedical Engineering Source Type: research