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991.
Development of a novel pulsatile bioreactor for tissue culture 总被引:1,自引:1,他引:1
Yos S. Morsi William W. Yang Amal Owida Cynthia S. Wong 《Journal of artificial organs》2007,10(2):109-114
The construction of tissue-engineered parts such as heart valves and arteries requires more than just the seeding of cells
onto a biocompatible/biodegradable polymeric scaffold. It is essential that the functionality and mechanical integrity of
the cell-seeded scaffold be investigated in vitro prior to in vivo implantation. The correct hemodynamic conditioning would
lead to the development of tissues with enhanced mechanical strength and cell viability. Therefore, a bioreactor that can
simulate physiological conditions would play an important role in the preparation of tissue-engineered constructs. In this
article, we present and discuss the design concepts and criteria, as well as the development, of a multifunctional bioreactor
for tissue culture in vitro. The system developed is compact and easily housed in an incubator to maintain sterility of the
construct. Moreover, the proposed bioreactor, in addition to mimicking in vivo conditions, is highly flexible, allowing different
types of constructs to be exposed to various physiological flow conditions. Initial verification of the hemodynamic parameters
using Laser doppler anemometry indicated that the bioreactor performed well and produced the correct physiological conditions. 相似文献
992.
Martijn W Heymans Dirk L Knol Willem van Mechelen Henrica CW de Vet 《BMC medical research methodology》2007,7(1):33
Background
Missing data is a challenging problem in many prognostic studies. Multiple imputation (MI) accounts for imputation uncertainty that allows for adequate statistical testing. We developed and tested a methodology combining MI with bootstrapping techniques for studying prognostic variable selection. 相似文献993.
Benjamin Kligler Mary Koithan Victoria Maizes Meg Hayes Craig Schneider Patricia Lebensohn Susan Hadley 《BMC medical education》2007,7(1):7
Background
As more integrative medicine educational content is integrated into conventional family medicine teaching, the need for effective evaluation strategies grows. Through the Integrative Family Medicine program, a six site pilot program of a four year residency training model combining integrative medicine and family medicine training, we have developed and tested a set of competency-based evaluation tools to assess residents' skills in integrative medicine history-taking and treatment planning. This paper presents the results from the implementation of direct observation and treatment plan evaluation tools, as well as the results of two Objective Structured Clinical Examinations (OSCEs) developed for the program. 相似文献994.
Background
Ischemic stroke is the most common cause of disability in North America and in addition to the generally accepted risk factors, there is increasing evidence for the potential pathophysiological role of genes. One of these genes, the endothelial nitric oxide synthase gene (NOS3) has been reported as a genetic risk factor for ischemic stroke. To independently confirm and extend the results of these previous reports, we investigated this gene as a risk factor for stroke in an ethnically diverse study population. 相似文献995.
996.
This paper describes the outcomes of episodes of care for adults in public sector mental health services across Australia, with a view to informing the debate on service quality. Health of the Nation Outcome Scales (HoNOS) change scores and effect sizes were calculated for 14,659 acute inpatient episodes and 23,692 community episodes. The results showed that people in contact with public sector mental health services generally do get better, although the magnitude of improvement depends on the setting and episode type. This confirmatory finding is particularly positive, given current community concerns about the quality and effectiveness of mental health services. 相似文献
997.
998.
Background
Correct diagnosis in psychiatry may be improved by novel diagnostic procedures. Computerized Decision Support Systems (CDSS) are suggested to be able to improve diagnostic procedures, but some studies indicate possible problems. Therefore, it could be important to investigate CDSS systems with regard to their feasibility to improve diagnostic procedures as well as to save time. 相似文献999.
1000.
MacDougall HG Brizuela AE Curthoys IS 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2003,148(2):166-175
Recent studies have shown that, although responses to long-duration, constant-current surface galvanic vestibular stimulation
(GVS) show substantial interindividual variability, individual subjects show a reliable, repeatable, idiosyncratic oculomotor
response pattern to GVS. It follows that GVS may be a more reliable stimulus than may have been anticipated from the literature.
The aim of the present study was to examine the metrics of 3D eye-movement responses to maintained (120 s), unilateral and
bilateral surface GVS. Eye movements were measured using computerised video-oculography. Two experiments were conducted: Experiment
1 examined whether the normal response is linear over increasing levels of current; and Experiment 2 examined (1) whether
the normal response to surface GVS is symmetrical when comparing stimulated sides, (2) whether the normal response to surface
GVS is symmetrical when the polarity of the stimulating current was reversed, and (3) whether there is additivity in the normal
response to combinations of unilateral/bilateral surface GVS. Five subjects participated in Experiment 1 and eight subjects
participated in Experiment 2. In both experiments, the onset of stimulation produced characteristic eye-movement responses:
changes in torsional position with the upper pole of both eyes rolling towards the anode and away from the cathode; together
with horizontal and torsional nystagmus with slow phases towards the anode and away from the cathode; and negligible vertical
nystagmus. These responses reversed direction at stimulus offset. In the fixation condition of Experiment 1, the magnitude
of ocular torsional position (OTP) and torsional nystagmus responses showed a linear relationship over conditions of increasing
current strength, as did OTP, torsional and horizontal nystagmus responses in darkness. The results of Experiment 2 showed
that responses to unilateral stimulation are symmetrical between stimulated sides, symmetrical between stimulating polarities,
and additive (with respect to responses to bilateral stimulation). The principles derived from these findings, as well as
those of recent studies, provide a foundation for future work investigating eye-movement responses to surface GVS in patients
with known types of vestibular dysfunction.
Electronic Publication 相似文献