Interaction force measurements for the design of tissue adhesives

Synthesis of tissue adhesives had been carried out in various laboratories in the past decades but the development is currently stalled. One of the key reasons, it is believed, is that researchers have not fully understood and resolved the role of the functional groups that are responsible for good adhesion to biological tissues. Further progress in synthesis is significantly hindered without this fundamental understanding. With this aim in mind, atomic force microscopy (AFM) has been exploited in this work to study the interactions between functional groups that are common to biological tissues. In this work, the AFM tip and substrates were functionalized and used to measure the non-specific interaction among these common functional groups. The ultimate aim of the study is to calculate the interaction force between a single pair of functional groups. A novel calculation method based on the AFM data and probe geometry is presented. The results provide insights into the strength of the bond between different functional groups and the could serve as a guide in selecting the appropriate functional groups in tissue adhesive synthesis. This method could be further applied to studies involving interfaces of biomedical devices where intermolecular interactions are of concern.     

A grounded theory guided approach to palliative care systems design

As healthcare looks for new and innovative ways to deliver more services with less resources we are increasingly turning to informatics based solutions. However, the means by which information systems (IS) are both designed and implemented will impact how successful the system will be at enhancing care delivery. We believe a key component to successful IS design is the methodological rigor by which design requirements are gleaned and applied. This paper describes our use of a grounded theory (GT) guided methodology for designing an ontology of palliative care severe pain management. In this paper we illustrate how the methodological rigor of GT was applied to three palliative information sources to allow us to gain an understanding of how severe pain is managed. We then illustrate how that understanding was formalized into an ontology and applied to IS design of a computer based tool to enhance education around palliative care severe pain management.     

Sedimentation theory and practical considerations for the design of centrifugal blood cell processes

This is the first of a five-part series discussing the basic conceptualization and evaluation of techniques for centrifugal separation of blood cells. In this paper, the basic concepts of sedimentation theory will be discussed. The next two papers will discuss the effects of plasma recycle and stagewise separations, respectively, as applied to continuous-flow and semicontinuous-flow processing systems. The subsequent paper will underline the differences between the theoretical approach and our experimental efforts, and the final paper will consider potential future process configurations and areas of expected improvement. A series of calculations is presented for the prediction of sedimentation velocities for red and white cells. The equations are simplified to investigate the regions of high red cell concentration, and are not valid for regions of concentrated platelets or white cells. The intent is to present a sample calculational design approach.     

Diffusion-tensor MRI: theory,experimental design and data analysis - a technical review

This article treats the theoretical underpinnings of diffusion-tensor magnetic resonance imaging (DT-MRI), as well as experimental design and data analysis issues. We review the mathematical model underlying DT-MRI, discuss the quantitative parameters that are derived from the measured effective diffusion tensor, and describe artifacts that arise in typical DT-MRI acquisitions. We also discuss difficulties in identifying appropriate models to describe water diffusion in heterogeneous tissues, as well as in interpreting experimental data obtained in such issues. Finally, we describe new statistical methods that have been developed to analyse DT-MRI data, and their potential uses in clinical and multi-site studies.     

Inhibitor design for SARS coronavirus main protease based on "distorted key theory"

In order to find effective peptide inhibitors against SARS CoV M(pro), an analysis was performed for 11 oligo-peptides that can be cleaved by the SARS coronavirus main protease (CoV M(pro), or 3CL(pro)). Flexible molecular alignments of the 11 cleavable peptides have provided useful insights into the chemical properties of their amino acid residues close to the cleavage site. Moreover, it was found through the ligand-receptor docking studies that of the 11 cleavable peptides, NH2-ATLQ / AIAS-COOH and NH2-ATLQ / AENV-COOH had the highest affinity with SARS CoV M(pro). The two octapeptides were selected as initial templates for further chemical modification to make them become effective inhibitors against the SARS enzyme according to the "distorted key" theory [K. C. Chou, Analytical Biochemistry 233 (1996) 1-14]. The possible chemical modification methods are proposed and examined. The approach developed in this study and the findings thus obtained might stimulate new strategies and provide useful information for drug design against SARS.     

Cavity ionisation theory applied to the design of a maximum permissible fluence instrument.

The maximun permissible fluence is proposed as a practical concept in radiological monitoring of photon fields. It is virtually this concept that is used for monitoring neutron fields. The practicability of designing instruments with a required response function over a large energy range is examined. Cavity isonisation theory is employed to examine the effect of gas filling, wall material, chamber size and wall thickness on response function and the optimum parameters for the design of an ionisation chamber are thus identified. An experimental chamber of parameters close to the optimum has been constructed and its response compared with the response calculated from cavity ionisation theory. It is concluded that it is possible to design an instrument, the energy response of which follows the maximum permissible fluence. The approach and data in this paper will facilitate any necessary design changes which would arise in the event of national regulation being modified.     

基于传统轴流泵设计理论的人工心脏泵及其数值模拟

传统轴流泵设计理论主要用来设计大型工业泵,很多都是经验设计的总结,人工心脏泵的体积相比较而言则要小得多.本文改进了传统轴流泵的设计理论,结合人工心脏泵的工作条件和水力条件,引入了扬程范围判断和速度三角形修正相结合的方法,配合迭代逼近获得了人工心脏泵的初始模型,CFD模拟分析为模型参数选择提供了依据.结论表明,这种设计方法可以用来快速简单的获得一系列高效的人工心脏泵模型,具有一定的代表性.     

Utilization of composite laminate theory in the design of synthetic soft tissues for biomedical prostheses

There are several advantages of using composite design considerations for the preparation of biomedical soft tissues. Using a composite laminate design, a wide range for compliance results, proving that the prosthesis compliance can be altered without a concomitant variation of other properties. The trend of compliance as a function of the reinforcement angle is discussed for an angle-ply composite of low compliance constituents, as well as the implications for stress-strain behaviour. Experimental examples pertinent to prosthetic arterial design are presented.     

Applying theory to the design of cultural competency training for medical students: a case study.

Although literature suggests that providing culturally sensitive care promotes positive health outcomes for patients, undergraduate medical education currently does not provide adequate cultural competency training. At most schools, cultural competency, as a formal, integrated, and longitudinal thread within the overall curriculum, is still in its infancy. In this article, the authors summarize the current practice of cultural competency training within medical education and describe the design, implementation, and evaluation of a theoretically based, year-long cultural competency training course for second-year students at Wake Forest University School of Medicine. Evaluation of the results indicate that the course was successful in improving knowledge, attitudes, and skills related to cultural competence as well as bringing about positive changes in the medical school's approach to cultural competency training. Also discussed are the implications of the outcomes for the development of culturally competent physicians and how using appropriate theory can help achieve desired outcomes.     

A quantitative approach to the design of antitumor drug dosage schedule via cell cycle kinetics and systems theory

A discrete-time kinetic model for chemotherapy was developed to deal with the effects of antitumor drugs on the cell cycle and proliferation kinetics of experimental tumor cell populations in which cell kinetic responses of chemotherapy are represented in terms of perturbation of cell kinetic parameters—cell age, cell size and DNA content distributions. The time-course behavior of these cell kinetic parameters was predicted by solving the discrete-time state equations which characterize the dynamics of tumor-drug interactions. The amount of antitumor drug administered was expressed to be the control function of the state equations and the transition matrix representing two modes of drug action, namely, cell kill and progression delay or accumulation of cells due to drug, was derived. The performance of the model, assessed by examining the effects of cell cycle stage-specific agents such as cytosine arabinoside on spontaneous AKR leukemia, compared favorably with experimental data. Utilizing an optimization scheme in engineering systems studies, an analytical method is described for optimizing the regimen of drug administration so as to maximize the effectiveness of drug dosage schedules and minimize the use of toxic amounts of the drug. The superiority of the schedule designed by an optimization scheme was evident at the termination of therapy, although the schedule designed by experimental trials reduced the number of surviving tumor cells more effectively than the one designed by an optimization scheme during the earlier therapy period. In the model, the proposed schedule will function more effectively for the entire therapy period when additional parameters of drug characteristics, such as the toxicity to the host and drug resistance, are encompassed.     

Experimental design optimisation: theory and application to estimation of receptor model parameters using dynamic positron emission tomography

The general framework and various criteria for experimental design optimisation are presented. The methodology is applied to the estimation of receptor-ligand reaction model parameters with dynamic positron emission tomography data. The possibility of improving parameter estimation using a new experimental design combining an injection of the beta+-labelled ligand and an injection of the cold ligand is investigated. Numerical simulations predict a remarkable improvement in the accuracy of the parameter estimates with this new experimental design and particularly the possibility of separate estimations of the association constant (k+1) and of the receptor density (B'max) in a single experiment. Simulation predictions are validated using experimental PET data in which parameter uncertainties are reduced by factors ranging from 17 to 1000.     

组织学与胚胎学课程思政策略与设计

习近平总书记2016年在全国高校思想政治工作会议上提出"课程思政"这一理念,指出高校要利用好课堂教学这个主渠道,让各类专业课程与思想政治理论课同向同行,形成协同效应[1],更好地完成"立德树人"这一教育根本任务.     

Modeling Interaction and Dispersion Effects in the Analysis of Gene-by-Environment Interaction

Behavior Genetics - Genotype-by-environment interaction (GxE) studies probe heterogeneity in response to risk factors or interventions. Popular methods for estimation of GxE examine multiplicative...