Abstract:
:The addition of cryopreservative agents (CPAs) to chondrocytes and natural and engineered cartilage is critical to protect the cells and tissues from freezing damage during cryopreservation, but this may cause cell damage, e.g. by osmotic shock. The damage could be minimized by the control of the cell volume excursion with the knowledge of cell membrane permeability. In this study, the cell volume responses of chondrocytes to three commonly used CPAs were evaluated using a perfusion microscope stage. The osmotic response of chondrocytes was measured to the perfusion with 1.4 M dimethyl sulfoxide (Me2SO), 1,2-propanediol and glycerol at 21 degrees C. Cell volumes and their transients were determined with image analysis. The cell membrane permeability parameters, including the hydraulic conductivity (Lp), the CPA permeability (omega) and the reflection coefficients (sigma) in the Kedem-Katchalsky (K-K) model, and the Lp and omega in the two-parameter model were determined. The correlated K-K parameters at 21 degrees C were Lp=0.166 +/- 0.035, 0.149 +/- 0.061, 0.212 +/- 0.041 microm/min atm, omega=(7.630 +/- 0.174) x 10(-2), (1.428 +/- 0.627) x 10(-2), (2.744 +/- 0.775) x 10(-2) microm/s and sigma=0.91 +/- 0.09, 0.82 +/- 0.11, 0.88 +/- 0.10 for Me(2)SO, glycerol and 1,2-propanediol, respectively. For the two-parameter model, the parameter values were Lp=0.163 +/- 0.040, 0.128 +/- 0.031, 0.169 +/- 0.025 microm/min atm, omega=(7.881 +/- 0.178) x 10(-2), (1.529 +/- 0.525) x 10(-2), (3.716 +/- 0.493) x 10(-2) microm/s for Me2SO, glycerol and 1,2-propanediol, respectively. No significant difference in the predictions of cell volume excursion during CPA addition was observed when using either the K-K model or the two-parameter model and it was hence advised to adopt the simple two-parameter model in the evaluation. The measured parameters can be used to optimise the CPA addition and removal protocols to maximize the cell survival during cryopreservation.
journal_name
Med Eng Physjournal_title
Medical engineering & physicsauthors
Xu X,Cui Z,Urban JPdoi
10.1016/s1350-4533(03)00073-0subject
Has Abstractpub_date
2003-09-01 00:00:00pages
573-9issue
7eissn
1350-4533issn
1873-4030pii
S1350453303000730journal_volume
25pub_type
杂志文章abstract::Multi-fragmented fractures of the proximal humerus are difficult to treat, especially in the case of osteoporotic bone. Intra-operative risks include cartilage damage when inserting multiple screws. A common post-operative complication is distal-varus collapse of the head. The aim of this study was to investigate if a...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2020.06.002
更新日期:2020-08-01 00:00:00
abstract::Contamination of EEG signals by artefacts arising from head movements has been a serious obstacle in the deployment of automatic neurological event detection systems in ambulatory EEG. In this paper, we present work on categorizing these head-movement artefacts as one distinct class and on using support vector machine...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2012.08.017
更新日期:2013-07-01 00:00:00
abstract::In this paper the biomechanical response of a novel dental preparation technique, referred to as the Anatomic-Functional-Geometry treatment (AFG), is investigated through a 3D nonlinear finite-element modelling approach. A comparative investigation against a standard technique employed in dental clinical practice is c...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2020.10.016
更新日期:2020-12-01 00:00:00
abstract::Pedicle screw loosening is still observed in clinical practice. Therefore, the understanding of the interaction between screw and bone is evermore subject of research. However, complex relationships between screw design and anchorage are rarely examined. For this reason, it is investigated whether screw fixation is pr...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2020.03.001
更新日期:2020-05-01 00:00:00
abstract::Pulse transit time (PTT) has emerged over the recent decades as a simple and non-invasive measure to quantify inspiratory effort changes in adults with sleep disordered breathing (SDB). Hence, this shows promise to be an effective screening tool for the paediatrics. However, little is known about its utility and suita...
journal_title:Medical engineering & physics
pub_type: 杂志文章,评审
doi:10.1016/j.medengphy.2006.01.006
更新日期:2007-01-01 00:00:00
abstract::The value of compliance of disposable elements such as infusion lines and syringes can significantly affect the performance characteristics of infusion devices. In a technique used to determine the compliance of infusion lines, the item under test is placed in a semi sealed water filled enclosure and the volume of flu...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2014.07.016
更新日期:2014-11-01 00:00:00
abstract::A method for assessment and second-order polynomial detrending of signals containing periodic components is proposed. The analytically derived properties of this method are validated with synthesized signals, processed by the computational procedure developed. It is shown that, in addition to accurate detrending, the ...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/s1350-4533(98)00077-0
更新日期:1998-11-01 00:00:00
abstract::To study the aetiology of pressure ulcers an MR-compatible loading device was developed. Magnetic resonance imaging provides the possibility of non-invasive evaluation of muscle tissue after compressive loading. Pressure was applied to the tibialis anterior region of rats by means of an indenter. The developed MR-comp...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2005.07.005
更新日期:2006-05-01 00:00:00
abstract::In this manuscript we describe the development and testing of a bipolar electrode for the simultaneous acquisition of ultrasound (US) images and surface electromyograms (EMGs) from the same muscle region. The developed electrode (bEMG-US) consists of two circular sensing regions (20 mm diameter) with fixed inter-elect...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2018.12.002
更新日期:2019-02-01 00:00:00
abstract::The purpose of the present study was to compare the passive angle-torque curves and the passive stiffness (PS, N m °(-)(1)) values recorded simultaneously from a load cell versus an isokinetic dynamometer during dorsiflexion stretch tolerance assessments in vivo. Nine healthy men (mean ± SD age = 21.4 ± 1.6 years) com...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2015.02.010
更新日期:2015-05-01 00:00:00
abstract::The results from studies of wave propagation in large arteries carried out over the last 25 years have shown that there is a good agreement among values of the imaginary part of the complex propagation coefficient, as expressed by pressure or flow-rate wave propagation velocity. However, there is considerable disparit...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/s1350-4533(96)00073-2
更新日期:1997-04-01 00:00:00
abstract::A decrease in mobility, related to illness, trauma or ageing, negatively affects the quality of life of the rapidly growing elderly population. A promising solution to maintain this standard of living is powered wearable mobility assist devices. Although they have achieved technological breakthroughs in the last decad...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2020.03.008
更新日期:2020-06-01 00:00:00
abstract::Biological tissues exhibit diverse mechanical behaviors because of complex material properties. As has been shown for ligaments and intervertebral discs, mathematical models often appear to well predict load responses individually by adjusting model parameters, but likely fail to describe several different load respon...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2007.03.001
更新日期:2008-03-01 00:00:00
abstract::Based on an adaptive genetic fuzzy clustering algorithm, a derived fuzzy knowledge model is proposed for quantitatively estimating the systolic arterial pressure (SAP), heart rate (HR), and bispectral index (BIS) using 12 patients and it validates them according to pharmacological reasoning. Also, a genetic proportion...
journal_title:Medical engineering & physics
pub_type: 杂志文章,随机对照试验
doi:10.1016/j.medengphy.2005.04.023
更新日期:2006-03-01 00:00:00
abstract::An ambulatory monitoring system has been developed to measure the weight-bearing achieved by a patient on their fractured leg. The system is lightweight, portable, and can monitor weight-bearing continuously over an extended period of time. In addition to mean weight-bearing, the system can also determine temporal par...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/s1350-4533(98)00061-7
更新日期:1998-10-01 00:00:00
abstract::This paper presents a sensor for monitoring and controlling the volume of the cerebrospinal fluid-filled ventricles of the brain. The measurement principle of the sensor exploits electrical conductivity differences between the cerebrospinal fluid and the brain tissue. The electrical contrast was validated using dog br...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2009.03.011
更新日期:2009-09-01 00:00:00
abstract::Total hip arthroplasty (THA) broaching involves impacting a broach handle with a mallet, facilitating force transmission to progress broaches into the femoral medullary canal. Limited surgical access during direct anterior THAs increases off-axis forces, potentially contributing to tissue damage. The aim was to charac...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2019.12.004
更新日期:2020-02-01 00:00:00
abstract:INTRODUCTION:A notable characteristic of bariatric surgery is the frequent manipulation of the bowel. The bowel is large, delicate, flexible, and has a natural lubricant on the tissue surface. Therefore the bowel is difficult to grasp and manipulate. Vacuum technique is commonly used in industry for all types of graspi...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2011.11.014
更新日期:2012-10-01 00:00:00
abstract::Computational fluid dynamics (CFD) simulations quantifying thoracic aortic flow patterns have not included disturbances from the aortic valve (AoV). 80% of patients with aortic coarctation (CoA) have a bicuspid aortic valve (BAV) which may cause adverse flow patterns contributing to morbidity. Our objectives were to d...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2012.07.015
更新日期:2013-06-01 00:00:00
abstract::Artificial blood pumps play an increasingly important role in the treatment of end-stage cardiac failure. The fluid dynamics of blood flow through such devices crucially affects their clinical effectiveness. Specifically, if the flow of blood stagnates or slowly re-circulates thrombus formation can occur and the avoid...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/s1350-4533(00)00023-0
更新日期:2000-04-01 00:00:00
abstract::It is important to be able to quantify changes in gait pattern accurately in order to understand the clinical implications of surgery or rehabilitation. Although supervised feed-forward backpropagation neural networks are very efficient in many pattern-recognition tasks, the genetic algorithm neural network (GANN), wh...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/s1350-4533(00)00011-4
更新日期:2000-01-01 00:00:00
abstract::In this study we integrated between confocal-based cell-specific finite element (FE) modeling and Virtual Cell (VC) transport simulations in order to determine trends of relationship between externally applied compressive deformations and build-up rates of oxygen in myoblast cells, and to further test how mild culture...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2011.04.008
更新日期:2011-11-01 00:00:00
abstract::This investigation explored pattern recognition of EMG signals produced by shoulder area muscles to identify the performance of a select number of lower arm motions. The signals were modelled as fourth-order autoregressive processes with the parameters of the models used to classify the different motions. The recorded...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/1350-4533(94)90024-8
更新日期:1994-03-01 00:00:00
abstract::Interest in patient-specific blood-flow circulation modeling has increased substantially in recent years. The availability of clinical data for geometric and elastic properties together with efficient numerical methods has now made model rendering feasible. This work uses 3-D fluid-structure interaction (FSI) to provi...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2012.08.009
更新日期:2013-06-01 00:00:00
abstract::The majority of the eye models developed in the late 90s and early 00s considers only heat conduction inside the eye. This assumption is not entirely correct, since the anterior and posterior chambers are filled aqueous humor (AH) that is constantly in motion due to thermally-induced buoyancy. In this paper, a three-d...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2016.05.011
更新日期:2016-08-01 00:00:00
abstract::The formation of pressure ulcers can be exacerbated by a breakdown in the integrity of the patient's skin caused by poor maintenance of the skin microclimate. Patient support systems (PSSs-specialised beds, mattresses, chairs, cushions and pads) play an important role in the dissipation of heat and moisture away from ...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/s1350-4533(00)00003-5
更新日期:1999-12-01 00:00:00
abstract::Understanding the load mechanics of orthopaedic implants is important to be able to predict their behaviour in-vivo. Much research, both mechanical and clinical, has been carried out on hip and knee implants, but less has been written about the mechanics of wrist implants. In this paper, the load mechanics of the Univ...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2016.02.008
更新日期:2016-06-01 00:00:00
abstract:AIMS:This study investigated the feasibility of automated differentiation between essential tissue types encountered during laparoscopic colorectal surgery using spectral analysis. METHODS:Wide band (440-1830 nm) spectra were collected using an optical fiber probe and spectrometer from freshly explanted, ex vivo, huma...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2013.01.004
更新日期:2013-07-01 00:00:00
abstract::We attempted to distinguish walking on level ground from walking on a stairway using waist acceleration signals. A triaxial accelerometer was fixed to the subject's waist and the three acceleration signals were recorded by a portable data logger at a sampling rate of 256 Hz. Twenty healthy male subjects were asked to ...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/s1350-4533(00)00041-2
更新日期:2000-05-01 00:00:00
abstract::Surface electromyography (sEMG) has dominated upper-limb prosthesis control for decades due to its simplicity and effectiveness [1-3]. However, the inherent variability of EMG signal hinders the flexible and accurate control of advanced multi-functional prosthesis. This study is an attempt to use ultrasonography (US) ...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2019.11.005
更新日期:2020-01-01 00:00:00