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This page shows you the most recent publications within this specialty of the MedWorm directory. This is page number 20.

Modeling and Analysis of Individualized Pharmacokinetics and Pharmacodynamics for Volatile Anesthesia
The presented procedure aims to establish an in-depth understanding of a derived mathematical model for drug distribution, pharmacokinetics, and drug effect, pharmacodynamics, during volatile anesthesia. A physiologically based, patient-specific model is derived, where the pharmacokinetic (PK) part consists of multiple blood and tissue compartmental models, each adjusted to the weight, height, gender, and age of the patient. The pharmacodynamic (PD) part is described by an effect site compartment and the Hill equation both linking the hypnotic effect measured by the Bispectral Index (BIS) to the arterial anesthetic concent...
Source: IEEE Transactions on Biomedical Engineering - December 18, 2013 Category: Biomedical Engineering Source Type: research

Study of chemical pretreatment and enzymatic saccharification for producing fermentable sugars from rice straw.
This study evaluated a cost-effective approach for the conversion of rice straw into fermentable sugars. The composition of rice straw pretreated with 1 % sulfuric acid or 1 % sodium hydroxide solution was compared to rice straw with no chemical pretreatment. Enzymatic saccharification experiments on non-pretreated rice straw (NPRS), pretreated rice straw (PRS), and pretreated rice straw with acid hydrolysate (PRSAH) were conducted in a series of batch reactors. The results indicated that pretreating the rice straw with dilute acid and base increased the cellulose content from 38 % to over 50 %. During enzymatic saccha...
Source: Bioprocess and Biosystems Engineering - December 18, 2013 Category: Biomedical Engineering Authors: Chen WH, Chen YC, Lin JG Tags: Bioprocess Biosyst Eng Source Type: research

Evaluation of power consumption of paddle wheel in an open raceway pond.
Abstract Open raceway ponds are widely adopted in microalgae cultivation. Paddle wheels consume the most part of power during the process of cultivation in open raceway ponds. The configuration of blades directly determines power consumption for paddle wheels. In this work, power consumption of four blades configurations was determined in a bench-scale open raceway pond of 2.2 m(2). The effect of blades configuration, the influence of filling levels from 5 to 15 cm and influence of rotational speeds from 7 to 15 r min(-1) on shaft power consumption (P S), fluid velocity (U c) and paddle wheel efficiency (η) was...
Source: Bioprocess and Biosystems Engineering - December 18, 2013 Category: Biomedical Engineering Authors: Li Y, Zhang Q, Wang Z, Wu X, Cong W Tags: Bioprocess Biosyst Eng Source Type: research

Comparison of Different Material Models to Simulate 3-D Breast Deformations Using Finite Element Analysis.
Abstract Biomechanical breast modeling using finite element (FE) analysis to predict 3-D breast deformations is of interest for various biomedical applications. Currently no consensus of reliable magnitudes of mechanical breast tissue properties exists. We therefore applied 12 material properties proposed in the literature to FE simulation models derived from prone MRI breast datasets of 18 female volunteers. A gravity free starting position is computed with an iterative FE algorithm followed by the calculation of the upright position of the breast and then compared to the real breast geometry in standing position ...
Source: Annals of Biomedical Engineering - December 18, 2013 Category: Biomedical Engineering Authors: Eder M, Raith S, Jalali J, Volf A, Settles M, Machens HG, Kovacs L Tags: Ann Biomed Eng Source Type: research

A microdevice for parallelized pulmonary permeability studies.
We describe a compartmentalized microdevice specifically designed to perform permeability studies across a model of lung barrier. Epithelial cell barriers were reproduced by culturing Calu-3 cells at the air-liquid interface (AIC) in 1 mm(2) microwells made from a perforated glass slide with an embedded porous membrane. We created a single basolateral reservoir for all microwells which eliminated the need to renew the growth medium during the culture growth phase. To perform drug permeability studies on confluent cell layers, the cell culture slide was aligned and joined to a collection platform consisting in 35 μL coll...
Source: Biomedical Microdevices - December 17, 2013 Category: Biomedical Engineering Authors: Bol L, Galas JC, Hillaireau H, Le Potier I, Nicolas V, Haghiri-Gosnet AM, Fattal E, Taverna M Tags: Biomed Microdevices Source Type: research

Oil-water biphasic parallel flow for the precise patterning of metals and cells.
Abstract Fluidic patterning is a convenient and versatile tool for the patterning of materials, cells and microstructures on surface and in microchannels. However, its performance is usually limited by transverse diffusion between fluid streams. It would blur the boundary and deteriorate the precision of patterns. In this paper, we adopted geometric confinement to generate biphasic parallel flow that is constituted of oil and water. Since there is minimum transverse diffusion in biphasic parallel flow, the performance of fluid patterning is expected to be improved. The results show that the metal (Silver and Chromi...
Source: Biomedical Microdevices - December 17, 2013 Category: Biomedical Engineering Authors: Mu X, Liang Q, Zhou J, Ren K, Hu P, Wang Y, Zheng Z, Luo G Tags: Biomed Microdevices Source Type: research

Mechanism and kinetics modeling of the enzymatic hydrolysis of α1-32 antibacterial peptide.
Abstract Several antibacterial peptides can be obtained by enzymatic hydrolysis of the α chain of bovine hemoglobin. The kinetics of α1-32 peptide hydrolysis by pepsin was studied at several temperatures (15, 23 and 37 °C). Intermediate and final peptides were identified, and their antibacterial activity was assessed against four bacterial species. Evolution of generated peptides concentration enabled to propose a reaction pathway describing the parallel and consecutive reactions taking place during the hydrolysis. A mathematical model, based on the proposed mechanism, was developed to describe the kinetics of ...
Source: Bioprocess and Biosystems Engineering - December 17, 2013 Category: Biomedical Engineering Authors: Hedhili K, Vauchel P, Dimitrov K, Kriaa K, Chataigné G, Hani K, Dhulster P, Nedjar-Arroume N Tags: Bioprocess Biosyst Eng Source Type: research

Purification of a thermostable chitinase from Bacillus cereus by chitin affinity and its application in microbial community changes in soil.
Abstract A thermostable chitinase was purified by chitin affinity from the culture supernatant of Bacillus cereus TKU028 with shrimp head powder (SHP) as the sole carbon/nitrogen source. TKU028 chitinase was purified using a one-step affinity adsorbent system, and the molecular mass of TKU028 chitinase (approximately 40 kDa) was then determined using SDS-PAGE. The enzyme was stable for 60 min at temperatures below 60 °C and stable over a broad pH range of 4-9 for 60 min. In addition, the temporal changes of a bacterial community in mangrove river sediment of the Tamsui River with added SHP were also analysed b...
Source: Bioprocess and Biosystems Engineering - December 17, 2013 Category: Biomedical Engineering Authors: Liang TW, Hsieh TY, Wang SL Tags: Bioprocess Biosyst Eng Source Type: research

Improved accuracy in 3D analysis using DLT after lens distortion correction.
This study aimed at assessing the applicability of a robust method to determine and correct lens distortion before using the direct linear transformation (DLT) algorithm in three-dimensional motion analysis. The known length of a rigid bar was reconstructed under different conditions of working volume (interpolation or extrapolation), number of cameras (2 or 4), position of the cameras (wide or narrow angle between optical axes), camera focal distance (4 or 8 mm) and number of control points (CPs; 8, 12, 18 or 162), through four different camera set-ups. The accuracy (percent root mean square error) of Set-up 2 (non-extra...
Source: Computer Methods in Biomechanics and Biomedical Engineering - December 17, 2013 Category: Biomedical Engineering Authors: Rossi MM, Silvatti AP, Dias FA, Barros RM Tags: Comput Methods Biomech Biomed Engin Source Type: research

Driving a musculoskeletal model with inertial and magnetic measurement units.
Abstract We developed and evaluated a new kinematic driver for musculoskeletal models using ambulatory inertial and magnetic measurement units (IMMUs). The new driver uses the orientation estimates based on sensor fusion of each individual IMMU and benefits from two important properties of musculoskeletal models. First, these models contain more complex, anatomical, kinematic models than those currently used for sensor fusion of multiple IMMUs and are continuously improved. Second, they allow movement between segment and measured sensor. For three different tasks, the new IMMU driver, (optical) marker drivers and a...
Source: Computer Methods in Biomechanics and Biomedical Engineering - December 17, 2013 Category: Biomedical Engineering Authors: Koning BH, van der Krogt MM, Baten CT, Koopman BF Tags: Comput Methods Biomech Biomed Engin Source Type: research

The End of Bad Meds
Up to 30 percent of the medications in the developing world are poor in quality because either they are improperly manufactured, degraded because of age or poor storage, or produced as counterfeits in rogue factories. The bad medicines can cause severe side effects and death. Identifying them is challenging, however. Many countries lack regulations or routine inspections. Testing equipment can be scarce, cumbersome and costly and can require extensive training--and provide only partial information about a drug's ingredients.A new device from Boston University, called PharmaCheck, may offer a portable, inexpensive and ...
Source: Scientific American - Official RSS Feed - December 16, 2013 Category: Science Tags: Health Source Type: research

Best estimation of spectrum profiles for diagnosing femoral prostheses loosening
In this study, experiments on a cadaveric dried bone with two kinds of fixation, Loose Stem class (LS) and Secure Stem class (SS), have been analyzed. To select the most discriminating approach to spectral estimation, five well known algorithms (Welch's, Burg's Auto-Regressive (AR), Auto-Regressive Moving Average (ARMA), Multiple Signal Classification (MUSIC) and Thomson's Multi-taper (MTM)) have been compared by using GDR. Finally, the use of the MTM method is proposed for the analysis of bone–stem interface vibratory signals, since it yields the most discriminatory profiles. (Source: Medical Engineering and Physics)
Source: Medical Engineering and Physics - December 16, 2013 Category: Biomedical Engineering Authors: Francisco Díaz-Pérez, Evelyn García-Nieto, Antonio Ros, Rafael Claramunt Tags: Papers Source Type: research

In vivo loads in the lumbar L3–4 disc during a weight lifting extension
This study provided quantitative data on in vivo disc loading that could help understand intrinsic biomechanics of the spine and improve surgical treatment of pathological discs using fusion or arthroplasty techniques. (Source: Clinical Biomechanics)
Source: Clinical Biomechanics - December 16, 2013 Category: Orthopaedics Authors: Shaobai Wang, Won Man Park, Yoon Hyuk Kim, Thomas Cha, Kirkham Wood, Guoan Li Tags: Regular Articles Source Type: research

Design parameters and the material coupling are decisive for the micromotion magnitude at the stem–neck interface of bi-modular hip implants
This study investigated micromotions at the stem–neck interface of two different designs: one design (Metha, Aesculap AG) has demonstrated a substantial number of in vivo neck fractures for Ti–Ti couplings, but there are no documented fractures for Ti–CoCr couplings. Conversely, for a comparable design (H-Max M, Limacorporate) with a Ti–Ti coupling only one clinical failure has been reported. Prostheses were mechanically tested and the micromotions were recorded using a contactless measurement system.For Ti–Ti couplings, the Metha prosthesis showed a trend towards higher micromotions compared to the H-Max M (6.5...
Source: Medical Engineering and Physics - December 16, 2013 Category: Biomedical Engineering Authors: S.Y. Jauch, G. Huber, H. Haschke, K. Sellenschloh, M.M. Morlock Tags: Papers Source Type: research

Convergence and Stability of Iteratively Re-weighted Least Squares Algorithms
In this paper, we study the theoretical properties of iteratively re-weighted least squares (IRLS) algorithms and their utility in sparse signal recovery in the presence of noise. We demonstrate a one-to-one correspondence between the IRLS algorithms and a class of Expectation-Maximization (EM) algorithms for constrained maximum likelihood estimation under a Gaussian scale mixture (GSM) distribution. The EM formalism, as well as the connection to GSMs, allow us to establish that the IRLS algorithms minimize smooth versions of the $ell_{nu}$ ‘norms’, for $0 < nu leq 1$ . We leverage EM theory to show that t...
Source: IEEE Transactions on Signal Processing - December 13, 2013 Category: Biomedical Engineering Source Type: research

Permutation Meets Parallel Compressed Sensing: How to Relax Restricted Isometry Property for 2D Sparse Signals
Traditional compressed sensing considers sampling a 1D signal. For a multidimensional signal, if reshaped into a vector, the required size of the sensing matrix becomes dramatically large, which increases the storage and computational complexity significantly. To solve this problem, the multidimensional signal is reshaped into a 2D signal, which is then sampled and reconstructed column by column using the same sensing matrix. This approach is referred to as parallel compressed sensing, and it has much lower storage and computational complexity. For a given reconstruction performance of parallel compressed sensing, if a so-...
Source: IEEE Transactions on Signal Processing - December 13, 2013 Category: Biomedical Engineering Source Type: research

Non-Negative Matrix Factorization Revisited: Uniqueness and Algorithm for Symmetric Decomposition
Non-negative matrix factorization (NMF) has found numerous applications, due to its ability to provide interpretable decompositions. Perhaps surprisingly, existing results regarding its uniqueness properties are rather limited, and there is much room for improvement in terms of algorithms as well. Uniqueness aspects of NMF are revisited here from a geometrical point of view. Both symmetric and asymmetric NMF are considered, the former being tantamount to element-wise non-negative square-root factorization of positive semidefinite matrices. New uniqueness results are derived, e.g., it is shown that a sufficient condition fo...
Source: IEEE Transactions on Signal Processing - December 13, 2013 Category: Biomedical Engineering Source Type: research

Bayesian Model Comparison With the g-Prior
Model comparison and selection is an important problem in many model-based signal processing applications. Often, very simple information criteria such as the Akaike information criterion or the Bayesian information criterion are used despite their shortcomings. Compared to these methods, Djuric's asymptotic MAP rule was an improvement, and in this paper, we extend the work by Djuric in several ways. Specifically, we consider the elicitation of proper prior distributions, treat the case of real- and complex-valued data simultaneously in a Bayesian framework similar to that considered by Djuric, and develop new model select...
Source: IEEE Transactions on Signal Processing - December 13, 2013 Category: Biomedical Engineering Source Type: research

A New Deterministic Identification Approach to Hammerstein Systems
The deterministic identification of Hammerstein systems is investigated in this paper. Based on the over-sampling technique, a new deterministic identification approach is presented, which blindly identifies the linear dynamic part followed by the estimation of the nonlinear function. The proposed method allows us to identify the Hammerstein system using an over-sampling rate smaller than the numerator polynomial's length of the linear dynamic part as required by other existing methods. In addition, it can obtain the true values of the system parameters in the noise-free case and an asymptotically consistent estimate in th...
Source: IEEE Transactions on Signal Processing - December 13, 2013 Category: Biomedical Engineering Source Type: research

Learning Nonlinear Generative Models of Time Series With a Kalman Filter in RKHS
This paper presents a novel generative model for time series based on the Kalman filter algorithm in a reproducing kernel Hilbert space (RKHS) using the conditional embedding operator. The end result is a nonlinear model that quantifies the hidden state uncertainty and propagates its probability distribution forward as in the Kalman algorithm. The embedded dynamics can be described by the estimated conditional embedding operator constructed directly from the training measurement data. Using this operator as the counterpart of the state transition matrix, we reformulate the Kalman filter algorithm in RKHS. For the state mod...
Source: IEEE Transactions on Signal Processing - December 13, 2013 Category: Biomedical Engineering Source Type: research

Uniformly Improving Maximum-Likelihood SNR Estimation of Known Signals in Gaussian Channels
The signal-to-noise ratio (SNR) estimation problem is considered for an amplitude modulated known signal in Gaussian noise. The benchmark method is the maximum-likelihood estimator (MLE), whose merits are well-documented in the literature. In this work, an affinely modified version of the MLE (AMMLE) that uniformly outperforms, over all SNR values, the traditional MLE in terms of the mean-square error (MSE) is obtained in closed-form. However, construction of an AMMLE whose MSE is lower, at every SNR, than the unbiased Cramér–Rao bound (UCRB), is shown to be infeasible. In light of this result, the AMMLE cons...
Source: IEEE Transactions on Signal Processing - December 13, 2013 Category: Biomedical Engineering Source Type: research

EM- and JMAP-ML Based Joint Estimation Algorithms for Robust Wireless Geolocation in Mixed LOS/NLOS Environments
We consider robust geolocation in mixed line-of-sight (LOS)/non-LOS (NLOS) environments in cellular radio networks. Instead of assuming known propagation channel states (LOS or NLOS), we model the measurement error with a general two-mode mixture distribution although it deviates from the underlying error statistics. To avoid offline calibration, we propose to jointly estimate the geographical coordinates and the mixture model parameters. Two iterative algorithms are developed based on the well-known expectation-maximization (EM) criterion and joint maximum a posteriori-maximum likelihood (JMAP-ML) criterion to approximate...
Source: IEEE Transactions on Signal Processing - December 13, 2013 Category: Biomedical Engineering Source Type: research

Coronary artery bypass grafting hemodynamics and anastomosis design: a biomedical engineering review
In this paper, coronary arterial bypass grafting hemodynamics and anastomosis designs are reviewed. The paper specifically addresses the biomechanical factors for enhancement of the patency of coronary artery bypass grafts (CABGs). Stenosis of distal anastomosis, caused by thrombosis and intimal hyperplasia (IH), is the major cause of failure of CABGs. Strong correlations have been established between the hemodynamics and vessel wall biomechanical factors and the initiation and development of IH and thrombus formation. Accordingly, several investigations have been conducted and numerous anastomotic geometries and devices h...
Source: BioMedical Engineering OnLine - December 13, 2013 Category: Biomedical Engineering Authors: Dhanjoo GhistaFoad Kabinejadian Source Type: research

Activated sludge model 2d calibration with full-scale WWTP data: comparing model parameter identifiability with influent and operational uncertainty.
Abstract The present work developed a model for the description of a full-scale wastewater treatment plant (WWTP) (Manresa, Catalonia, Spain) for further plant upgrades based on the systematic parameter calibration of the activated sludge model 2d (ASM2d) using a methodology based on the Fisher information matrix. The influent was characterized for the application of the ASM2d and the confidence interval of the calibrated parameters was also assessed. No expert knowledge was necessary for model calibration and a huge available plant database was converted into more useful information. The effect of the influent and...
Source: Bioprocess and Biosystems Engineering - December 13, 2013 Category: Biomedical Engineering Authors: Machado VC, Lafuente J, Baeza JA Tags: Bioprocess Biosyst Eng Source Type: research

Merging multi-camera data to reduce motion analysis instrumental errors using Kalman filters.
Abstract In motion capture systems, markers are often seen by multiple cameras. All cameras do not measure the position of the markers with the same reliability because of environmental factors such as the position of the marker in the field of view or the light intensity received by the cameras. Kalman filters offer a general framework to take the reliability of the various cameras into account and consequently improve the estimation of the marker position. The proposed process can be applied to both passive and active systems. Several reliability models of the cameras are compared for the Codamotion active system...
Source: Computer Methods in Biomechanics and Biomedical Engineering - December 13, 2013 Category: Biomedical Engineering Authors: Schwartz C, Denoël V, Forthomme B, Croisier JL, Brüls O Tags: Comput Methods Biomech Biomed Engin Source Type: research

Conventional and complex modal analyses of a finite element model of human head and neck.
This study employs both the traditional and the complex modal analyses of a detailed finite element model of human head-neck system to determine modal responses in terms of resonant frequencies and mode shapes. It compares both modal responses without ignoring mode shapes, and these results are reasonably in agreement with the literature. Increasing displacement contour loops within the brain in higher frequency modes probably exhibits the shearing and twisting modes of the brain. Additional and rarely reported modal responses such as 'mastication' mode of the mandible and flipping mode of nasal lateral cartilages are iden...
Source: Computer Methods in Biomechanics and Biomedical Engineering - December 13, 2013 Category: Biomedical Engineering Authors: Tse KM, Tan LB, Lim SP, Lee HP Tags: Comput Methods Biomech Biomed Engin Source Type: research

[Retrospective] Michael Neuberger (1953–2013)
A sharp immunologist who unraveled the mechanisms of antibody diversification helped to launch a biomedical engineering revolution. Authors: Julian E. Sale, Ketan J. Patel, Facundo D. Batista (Source: Science: Current Issue)
Source: Science: Current Issue - December 13, 2013 Category: Science Authors: Julian E. Sale Tags: Retrospective Source Type: research

Small-scale slow glucose feed cultivation of Pichia pastoris without repression of AOX1 promoter: towards high throughput cultivations.
Abstract Recombinant protein synthesis in Pichia pastoris is generally controlled by the strong methanol inducible AOX1 promoter which is repressed by glucose and glycerol. In shake flasks, commonly one or two methanol pulses are added per day for induction. Such pulse feeding procedure leads to carbon starvation phases, which may enhance proteolytic activities and, therefore, cause product losses. Starvation between the methanol pulses could be avoided with a continuous enzymatic feed of glucose from a glucose-based polymer. The amount of glucose was low enough to prevent AOX1 repression by glucose. Energy and car...
Source: Bioprocess and Biosystems Engineering - December 12, 2013 Category: Biomedical Engineering Authors: Panula-Perälä J, Vasala A, Karhunen J, Ojamo H, Neubauer P, Mursula A Tags: Bioprocess Biosyst Eng Source Type: research

A study of the metabolism of transplanted tumor in the lung by micro PET/CT in mice
In this study, the metabolism of tumor in lung was quantitatively described in mice. The melanoma was transplanted into the lung of mice, and the metabolism of the transplanted tumor was detected by micro PET/CT with [18F]fluoro-2-deoxy-d-glucose (FDG). Nine mice were transplanted with B16 melanoma cells through their tail vein. Lung tumor was detected by pathological method. The lesions smaller than 1mm could hardly be directly detected directly by micro PET/CT, while the tumor with a 1–4mm diameter could be detected by micro PET/CT. A metabolic model with three compartments was separately established for lung tumors an...
Source: Medical Engineering and Physics - December 12, 2013 Category: Biomedical Engineering Authors: Huiting Qiao, Jun Li, Yingmao Chen, Daifa Wang, Jintao Han, Mengqi Mei, Deyu Li Tags: Papers Source Type: research

Evaluation of mechanical properties of three different screws for rapid maxillary expansion
Conclusions: All tested devices showed the capability of developing expansion forces (16-20 kg) adequate for RME. The A2620 and Hyrax expanders showed a greater level of rigidity than the Palatal Split screw. (Source: BioMedical Engineering OnLine)
Source: BioMedical Engineering OnLine - December 11, 2013 Category: Biomedical Engineering Authors: Matteo CamporesiLorenzo FranchiTiziana DoldoEfisio Defraia Source Type: research

A rapid in situ immobilization of D-amino acid oxidase based on immobilized metal affinity chromatography.
Abstract A rapid in situ immobilization process was developed based on conventional separation technique of immobilized metal affinity chromatography (IMAC) and was studied in the case of D-amino acid oxidase (DAAO) with binding-enhancing Heli-tag (His-Arg-Asn-Tyr-Gly-Gly-Cys-Cys-Gly). A recombinant Escherichia coli strain JM105 (Δase)/pGEMK-R-DAAO-Heli was successfully constructed to synthesize chimeric protein DAAO-Heli. Without additional purification procedure, the tagged enzyme DAAO-Heli could be directly immobilized to EP-IDA-Ni(2+) support with purity of 90 % and DAAO activity of over 70 U/g support. Expe...
Source: Bioprocess and Biosystems Engineering - December 11, 2013 Category: Biomedical Engineering Authors: Hou J, Jin Q, Du J, Li Q, Yuan Q, Yang J Tags: Bioprocess Biosyst Eng Source Type: research

Numerical study of the influence of water evaporation on radiofrequency ablation
Conclusion: The mathematical model simulates the water evaporation and diffusion during radiofrequency ablation and may be used for better clinical design of radiofrequency equipment and treatment protocol planning. (Source: BioMedical Engineering OnLine)
Source: BioMedical Engineering OnLine - December 10, 2013 Category: Biomedical Engineering Authors: Qing ZhuYuanyuan ShenAili ZhangLisa Xu Source Type: research

CWRU faculty members named National Academy of Inventors Fellows
(Case Western Reserve University) Case Western Reserve University's Robert H. Miller, professor of neurosciences and the university's vice president for research, and P. Hunter Peckham, the Donnell Institute Professor of biomedical engineering and orthopedics and founder of the Cleveland Functional Electrical Stimulation Center, have been named Fellows of the National Academy of Inventors. (Source: EurekAlert! - Social and Behavioral Science)
Source: EurekAlert! - Social and Behavioral Science - December 10, 2013 Category: Global & Universal Source Type: news

Cycle length and COD/N ratio determine properties of aerobic granules treating high-nitrogen wastewater.
Abstract Aerobic granule characteristic in sequencing batch reactors treating high-nitrogen digester supernatant was investigated at cycle lengths (t) of 6, 8 and 12 h with the COD/N ratios in the influent of 4.5 and 2.3. The biomass production (Y obs) correlated with the extracellular polymeric substances (EPS) in grams per COD removed. Denitrification efficiency significantly decreased as the amount of EPS in biomass increased, suggesting that organic assimilation in EPS hampers nitrogen removal. Granule hydrophobicity was highest at t of 8 h; the t has to be long enough to remove pollutants, but not so long th...
Source: Bioprocess and Biosystems Engineering - December 10, 2013 Category: Biomedical Engineering Authors: Cydzik-Kwiatkowska A, Bernat K, Zielińska M, Wojnowska-Baryła I Tags: Bioprocess Biosyst Eng Source Type: research

Automatic identification of structured process models based on biological phenomena detected in (fed-)batch experiments.
Abstract In this paper, we present a set of methods to automatically propose structured process models from an automated analysis of (fed-)batch experiments. Therefore, the measurements are numerically compensated for the influence of feeding and sampling, and the qualitative behavior of the measurements is revealed. As measurements from fermentations are inherently noisy, we introduce a method that divides the compensated curves into several episodes in a probabilistic framework to better handle these shortcomings. The probability of biological phenomena that reveal crucial information about the underlying reactio...
Source: Bioprocess and Biosystems Engineering - December 10, 2013 Category: Biomedical Engineering Authors: Herold S, King R Tags: Bioprocess Biosyst Eng Source Type: research

Heterologous expression and biochemical characterization of glucose isomerase from Thermobifida fusca.
Abstract Glucose isomerase (GIase) catalyzes the isomerization of D-glucose to D-fructose. The GIase from Thermobifida fusca WSH03-11 was expressed in Escherichia coli BL21(DE3), and the purified enzyme took the form of a tetramer in solution and displayed a pI value of 5.05. The temperature optimum of GIase was 80 °C and its half life was about 2 h at 80 °C or 15 h at 70 °C. The pH optimum of GIase was 10 and the enzyme retained 95 % activity over the pH range of 5-10 after incubating at 4 °C for 24 h. Kinetic studies showed that the K m and K cat values of the enzyme are 197 mM and 1,688 min(-1), re...
Source: Bioprocess and Biosystems Engineering - December 10, 2013 Category: Biomedical Engineering Authors: Deng H, Chen S, Wu D, Chen J, Wu J Tags: Bioprocess Biosyst Eng Source Type: research

Endothelial Insulin-Like Growth Factor-1 Modulates Proliferation and Phenotype of Smooth Muscle Cells Induced by Low Shear Stress.
Abstract Endothelial cells (ECs) are directly exposed to shear stress and modulate the neighboring vascular smooth muscle cells (VSMCs), which plays important roles in vascular remodeling during atherosclerosis. Our previous research revealed that insulin-like growth factors (IGFs) might participate in low shear stress (LowSS) induced vascular remodeling, which remains to be elucidated. Using EC/VSMC co-cultured parallel-plate flow chamber, LowSS (5 dyn/cm(2)) was applied and normal shear stress (NSS, 15 dyn/cm(2)) was used as control. LowSS induced IGF-1 secretion from ECs, which subsequently phosphorylated IGF-1 ...
Source: Annals of Biomedical Engineering - December 10, 2013 Category: Biomedical Engineering Authors: Wang L, Han Y, Shen Y, Yan ZQ, Zhang P, Yao QP, Shen BR, Gao LZ, Qi YX, Jiang ZL Tags: Ann Biomed Eng Source Type: research

Constitutive Modeling of Pia-Arachnoid Complex.
In this study, the nonlinear viscoelastic, transversely isotropic material properties of the PAC were modeled as Mooney-Rivlin ground substance with collagen fibers strengthening within the meningeal plane through an exponential model. The material constants needed were determined using experimental data from in-plane tension, normal traction, and shear tests conducted on bovine specimens. Results from this study provide essential information to properly model the PAC membrane, an important component in the skull/brain interface, in a computational brain model. Such an improved representation of the skull/brain interface w...
Source: Annals of Biomedical Engineering - December 10, 2013 Category: Biomedical Engineering Authors: Jin X, Mao H, Yang KH, King AI Tags: Ann Biomed Eng Source Type: research