Mutation spectrum of 122 hemophilia A families from Taiwanese population by LD-PCR, DHPLC, multiplex PCR and evaluating the clinical application of HRM

<p>Abstract</p> <p>Background</p> <p>Hemophilia A represents the most common and severe inherited hemorrhagic disorder. It is caused by mutations in the F8 gene, which leads to a deficiency or dysfunctional factor VIII protein, an essential cofactor in the factor X activation complex.</p> <p>Methods</p> <p>We used long-distance polymerase chain reaction and denaturing high performance liquid chromatography for mutation scanning of the F8 gene. We designed the competitive multiplex PCR to identify the carrier with exonal deletions. In order to facilitate throughput and minimize the cost of mutation scanning, we also evaluated a new mutation scanning technique, high resolution melting analysis (HRM), as an alternative screening method.</p> <p>Results</p> <p>We presented the results of detailed screening of 122 Taiwanese families with hemophilia A and reported twenty-nine novel mutations. There was one family identified with whole exons deletion, and the carriers were successfully recognized by multiplex PCR. By HRM, the different melting curve patterns were easily identified in 25 out of 28 cases (89%) and 15 out of 15 (100%) carriers. The sensitivity was 93 % (40/43). The overall mutation detection rate of hemophilia A was 100% in this study.</p> <p>Conclusion</p> <p>We proposed a diagnostic strategy for hemophilia A genetic diagnosis. We consider HRM as a powerful screening tool that would provide us with a more cost-effective protocol for hemophilia A mutation identification.</p

Geometrical analysis of thread milling – Part 2:Calculation of uncut chip thickness

Thread milling offers interesting possibilities for machining internal or external threads. This machining technique uses a mill with a triangular profile for metric threads and a helical interpolation strategy. Thus, the uncut chip thickness can not be easily evaluated from a simplified approach. The present study deals with a model for calculating uncut chip thickness during internal thread milling. This step is needed to understand and model the cutting forces. The model developed uses the geometrical definitions of the mill, and takes into account the milling mode and the cutting conditions. The link with the interferences between the tool and the thread is also established and corroborates a previous study. A full analyticalformulation of the problem is proposed, and results from different milling settings are presented

Modeling of interferences during thread milling operation

Thread milling is becoming more and more employed as a technique for producing thread, due to its advantages for industrial manufacturing sectors, such as the aeronautics, aerospace, and energy industries. The thread milling operation is atypical and several aspects have to be taken into account to perform it in good conditions. As for milling or grinding worms, grooves, thread or others sculptured surfaces, in thread milling, there exists a geometrical interference between the tool and the nominal surface which would be obtained. Thread mills have quite complex geometry and their profile has an effect on the machined thread. The present study details geometrical aspects of the thread milling process. This article deals with the link between thread mill geometry and nominal thread profile. An approach is proposed to analyze the thread profile generated by the thread mill envelope. It is deduced that thread milling produces interferences, i.e. the machined thread profile is affected by an overcut. A method is proposed to correct this geometrical error in order to produce accurate thread