Biological variations of ADAMTS13 and von Willebrand factor in human adults     

Meltem Kilercik  Abdurrahman Coskun  Mustafa Serteser  Deniz Inan  Ibrahim Unsal 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2014,24(1):138-145

Background:

The ultra-large von Willebrand factor (vWF) multimers are very active and must be degraded by ADAMTS13 for optimal activity. A severe functional deficiency of ADAMTS13 has been associated with thrombotic thrombocytopenic purpura. The correct interpretation of patient vWF and ADAMTS13 plasma levels requires an understanding of the biological variation associated with these analytes. In the present paper, we aimed to determine the biological variation of ADAMTS13 and vWF in human adults.

Materials and methods:

Blood samples were collected weekly from 19 healthy subjects for 5 consecutive weeks. vWF activity and antigenicity were determined using aggregometric and immunoturbidimetric methods. ADAMTS13 antigenicity and activity were determined by ELISA.

Results:

The within-subject biological variations for vWF activity and antigenicity were 8.06% and 14.37%, respectively, while the between-subject biological variations were 18.5% and 22.59%, respectively. The index of individuality for vWF activity was 0.44, while vWF antigenicity was 0.64. Similarly, ADAMTS13 activity and antigenicity within-subject biological variations were 12.73% and 9.75%, respectively, while between-subject biological variations were 9.63% and 6.28%, respectively. The ADAMTS13 indexes of individuality were 1.32 and 1.55, respectively.

Conclusion:

We report high biological variation and individuality in vWF antigenicity and activity levels. However, ADAMTS13 antigenicity and activity displayed high biological variation, but low individuality. Thus, population-based reference intervals may be useful for monitoring ADAMTS13 antigenicity and activity, but not for vWF, which displays high individuality. These findings should be considered when determining the reference interval and other clinical variables associated with ADAMTS13 and vWF levels.  相似文献   

Off line simulation system of machining processes     

Ibrahim M. Deiab  Stephen C. Veldhuis 《Journal of The Franklin Institute》2007,344(5):565-576

The primary objective for modeling of machining processes is to develop a predictive capability of machining performance in order to facilitate effective planning of machining operations. This capability leads to faster implementation, higher performance, quality at a lower cost. This comes about due to improved selection of machining parameters, optimal fixture design and the avoidance of tool failure. The simulation system presented simultaneously considers the effect of cutter geometry, the cutter's initial position errors, workpiece geometry, machine tool dynamics, and workpiece/fixture system dynamics on the machining process.The integration of all of the above in one model provides an off-line tool to simulate and optimize the machining parameters and the fixture configuration cutting both lead and production time. The modular nature of the simulation system presented allows for the study of many different machining processes. The cutting forces in this system are modeled using a mechanistic approach. NURBS curves and surfaces are utilized for the geometric modeling and simulation of the machining process. While a finite element method is used to model and analyze the workpiece/fixture dynamics. Two case studies are presented to demonstrate the practical application of the presented simulation. The first case presents the optimization of the fixture configuration of a generic automotive component. While the second case presents the results of simulations performed on a novel mill/grind machining process. This process is a combination of face milling and grinding in one operation. Some simulated results are presented along with experimental validation.  相似文献   

Molecular Characterization of Iranian Patients with Possible Familial Hypercholesterolemia     

Farrokhi E  Shayesteh F  Asadi Mobarakeh S  Roghani Dehkordi F  Ghatreh Samani K  Hashemzadeh Chaleshtori M 《Indian journal of clinical biochemistry : IJCB》2011,26(3):244-248

Familial hypercholesterolemia (FH) is an autosomal dominant disorder of lipoprotein metabolism caused mainly by mutations in the low-density lipoprotein receptor (LDLR) and apolipoprotein B 100 (APOB) genes. Until now, the molecular basis of FH has been demonstrated in detail in many populations, but there is still very limited Molecular data concerning FH in Iran. The aim of this study was to characterize the LDLR and APOB gene mutations in an Iranian population. A total of 30 non-related Iranian possible FH subjects were studied. Diagnosis of FH was based on the Dutch Lipid Clinic Network diagnostic criteria. All samples were initially tested for three common APOB gene mutations including R3500Q, R3500 W and R3531C using PCR-RFLP assay. Subsequently, promoter and coding region of the LDLR gene was screened by PCR-SSCP analysis and positive results were confirmed by DNA sequencing. Four previously reported polymorphisms 1413G > A, 1725C > T, 1773T > C and 2140 + 5G > A were found in ~17% (5/30) of population studied. Moreover, no variation was found in APOB gene. Our data indicated that LDLR and APOB gene mutations have not contribution to possible FH in Iranian population studied here. However, we examined three common APOB mutations and LDLR in only 30 patients, and to determine the role of these genes in developing FH in Iran, more FH samples and populations needed to be investigated for the mutations of the related genes.  相似文献   

Optimization of fuzzy model using genetic algorithm for process control application     

Rubiyah Yusof  Ribhan Zafira Abdul Rahman  Marzuki Khalid  Mohd Faisal Ibrahim 《Journal of The Franklin Institute》2011,348(7):1717-1737

A technique for the modeling of nonlinear control processes using fuzzy modeling approach based on the Takagi-Sugeno fuzzy model with a combination of genetic algorithm and recursive least square is proposed. This paper discusses the identification of the parameters at the antecedent and consequent parts of the fuzzy model. For the antecedent fuzzy parameters, genetic algorithm is used to tune them while at the consequent part, recursive least squares approach is used to identify the system parameters. This approach is applied to a process control rig with three subsystems: a heating element, a heat exchanger and a compartment tank. Experimental results show that the proposed approach provides better modeling when compared with Takagi Sugeno fuzzy modeling technique and the linear modeling approach.  相似文献   

Factors affecting attitudes and intentions towards knowledge sharing in the Dubai Police Force     

Ibrahim Seba  Jennifer Rowley  Sian Lambert 《International Journal of Information Management》2012

This study contributes to the limited research base on knowledge sharing in public sector organisations, specifically police forces, and organisations in the Middle East through a case study investigation into the factors that affect knowledge sharing in the Dubai Police Force. A questionnaire-based survey was conducted with staff in key departments in the Dubai Police Force. Informed by the literature and by interviews conducted in a previous phase, the core of the questionnaire was a bank of Likert-style questions covering the dependent variables intention to knowledge share, and attitude towards knowledge sharing, and the independent variables, trust, organisational structure, leadership, reward, time, and information technology. Data was analysed using structured equation modelling, in order to test the measurement model using confirmatory factor analysis, and to test the structural model. The structural model suggests a strong relationship between attitude to knowledge sharing, and intention to share knowledge. Hypotheses regarding the influence of leadership, trust, organisational structure, time, and information technology on attitude to knowledge sharing were upheld. Rewards did not to influence attitude to knowledge sharing. Recommendations are offered for practice and further research.  相似文献   

Evaluating research performance of research institutes within Malaysian universities: an alternative assessment framework     

Ta  Goh Choo  Halim  Sharina Abdul  Azman  Norzaini  Komoo  Ibrahim  Mokhtar  Mazlin 《Tertiary Education and Management》2021,27(4):331-349

Tertiary Education and Management - Evaluation of research performance has significantly increased in importance, particularly in many emerging higher education systems. In Malaysia, the Malaysian...  相似文献   

Optimal sizing of piezo-actuators for minimum-deflection design of frames under uncertain loads     

Sarp Adali  Ibrahim S. Sadek  James M. Sloss 《Journal of The Franklin Institute》2007,344(5):698-710

Optimal piezo-actuator sizes and locations for a frame structure under bending load uncertainty are determined with the objective of minimizing the deflection under worst case of loading. The bending moments generated by the piezo-actuators are used for deflection control, i.e., to minimize the maximum deflection. The frame is subjected to a tip load which lies in an uncertainty domain with regard to its magnitude and direction. The specific uncertain loading studied in the present paper involves a load of given magnitude but of unknown direction, which should be determined to produce the highest deflection. The worst case of loading depends on the size and location of the actuators leading to a nested problem of optimization (design) and anti-optimization (uncertainty problem). Results are given for deterministic and uncertain loading conditions.  相似文献   

Cross-cultural counseling and psychotherapy: An existential-psychological approach     

Farah A. Ibrahim 《International journal for the advancement of counseling》1984,7(3):159-169

  相似文献   

Evaluating students experiences using a virtual learning environment: satisfaction and preferences     

Hamutoglu  Nazire Burcin  Gemikonakli  Orhan  Duman  Ibrahim  Kirksekiz  Ali  Kiyici  Mubin 《Educational technology research and development : ETR & D》2020,68(1):437-462

Educational technology research and development - Virtual learning environments (VLEs) are web-based software systems that enable students to interact with their teachers and classmates, access...  相似文献   

The need for Saudi faculty and the media for instruction in Saudi Arabian universities     

Ibrahim A. Al-Shami 《Higher Education》1983,12(3):285-296

The past three decades have witnessed rapid growth and expansion in higher education. This study attempts to throw some light on the extent to which Saudi universities have attracted national faculty to match the level of increase in students' enrollment. Another important issue which is discussed in this article is the extent to which Arabic, the national language, is used as a medium of instruction in Saudi universities.Saudi government publications, as well as some international statistical documents, have been utilized in evaluating the possibility of achieving a national faculty and the possibility of using Arabic as the medium of instruction. Practical suggestions are offered to help the higher educational system in Saudi Arabia overcome some of the current problems.  相似文献