Modelling and Evaluation of Electrical Resonance Eddy Current for Submillimeter Defect Detection

Eddy current (EC) inspection is used extensively in non-destructive testing (NDT) to detect surface-breaking defects of engineering components. However, the sensitivity of conventional eddy current inspection has plateaued in recent years. The ability to detect submillimetre defects before it becomes critical would allow engineering components to remain in-service safely for longer. Typically, it is required that higher frequency EC is employed to achieve a suitable sensitivity for detection of such submillimetre defects. However, that would lead to significant electromagnetic noise affecting the sensitivity of the inspection. To overcome this issue, the electrical-resonance based eddy current method has been proposed, where the electrical enhanced resonance signal increases the contrast between signal and noise, thus improving the sensitivity of the defect detection. This work aims to investigate the electrical-resonance system via simulation technology using combination of fast numerical-based simulation and circuit approach. Leveraging on this model, the detection system can be optimized by performing parameters tuning. Investigation of both experiment and simulation develops a precise calibration model for submillimeter defects detection

Three-dimensional solution structures of the chromodomains of cpSRP43

[[abstract]]Chloroplasts contain a unique signal recognition particle (cpSRP). Unlike the cytoplasmic forms, the cpSRP lacks RNA but contains a conserved 54-kDa GTPase and a novel 43-kDa subunit (cpSRP43). Recently, three functionally distinct chromodomains (CDs) have been identified in cpSRP43. In the present study, we report the three-dimensional solution structures of the three CDs (CD1, CD2, and CD3) using a variety of triple resonance NMR experiments. The structure of CD1 consists of a triple-stranded beta-sheet segment. The C-terminal helical segment typically found in the nuclear chromodomains is absent in CD1. The secondary structural elements in CD2 and CD3 include a triple-stranded antiparallel beta-sheet and a C-terminal helix. Interestingly, the orientation of the C-terminal helix is significantly different in the structures of CD2 and CD3. Critical comparison of the structures of the chromodomains of cpSRP43 with those found in nuclear chromodomain proteins revealed that the diverse protein-protein interactions mediated by the CDs appear to stem from the differences that exist in the surface charge potentials of each CD. Results of isothermal titration calorimetry experiments confirmed that only CD2 is involved in binding to cpSRP54. The negatively charged C-terminal helix in CD2 possibly plays a crucial role in the cpSRP54-cpSRP43 interaction.[[fileno]]2010329010011[[department]]化學

Resonance assignments for mouse S100A13

[[abstract]]S100A13 is a 12 kDa protein that is selectively expressed in heart, kidney, spleen and small intestine. S100A13 shares only about 50% amino acid sequence homology with other members of the S100 family (Heizmann and Cox, 1998). Interestingly, polyclonal antibodies raised against S100A13 fail to cross react with other S100 proteins. S100A13 is the only member of the S100 family that is shown to be involved in the non-classical export of signal-peptide less proteins such as fibroblast growth factors, interleukin 1 a and synaptotagmins (Prudovsky et al., 2003). No NMR structure of S100A13 is available and, to our knowledge this is the first report of the resonance assignment of the protein (S100A13). 1H–15N HSQC spectrum of S100A13 is reasonably well-dispersed with uniform signal intensities. About 97% of the 1H–15N cross peaks in the HSQC spectrum (excluding 1 proline residue) were assigned. The backbone 1H–15N resonances of Lys30, Leu56 and Lys91 could not be assigned. Regions near these sites exhibit weakened and broadened signal in all spectra acquired. About 97% of the Ca, 95% of the Cb, 97% of the CaH and 95% of the CbH resonances in the protein have been unambiguously assigned. Secondary structure prediction using CSI method and TALOS revealed that S100A13 consists of 4 helices [helixI (residues 8–24), helixII (residues 35–47), helixIII (residues 54–69) and helixIV (residues, 75–93)] and 2 antiparallel beta strands (strandI (residues 31–34) and strandII (residues, 70–73) ] (BMRB accession number 6484).[[fileno]]2010329010012[[department]]化學

kappa-Hefutoxin1, a novel toxin from the scorpion Heterometrus fulvipes with unique structure and function. Importance of the functional diad in potassium channel selectivity.

Journal of Biological Chemistry2773330040-3004

kappa-Hefutoxin1, a Novel Toxin from the Scorpion Heterometrus fulvipes with Unique Structure and Function

8 page(s

Three-dimensional solution structures of the chromodomains of cpSRP43

Chloroplasts contain a unique signal recognition particle (cpSRP). Unlike the cytoplasmic forms, the cpSRP lacks RNA but contains a conserved 54-kDa GTPase and a novel 43-kDa subunit (cpSRP43). Recently, three functionally distinct chromodomains (CDs) have been identified in cpSRP43. In the present study, we report the three-dimensional solution structures of the three CDs (CD1, CD2, and CD3) using a variety of triple resonance NMR experiments. The structure of CD1 consists of a triple-stranded beta-sheet segment. The C-terminal helical segment typically found in the nuclear chromodomains is absent in CD1. The secondary structural elements in CD2 and CD3 include a triple-stranded antiparallel beta-sheet and a C-terminal helix. Interestingly, the orientation of the C-terminal helix is significantly different in the structures of CD2 and CD3. Critical comparison of the structures of the chromodomains of cpSRP43 with those found in nuclear chromodomain proteins revealed that the diverse protein-protein interactions mediated by the CDs appear to stem from the differences that exist in the surface charge potentials of each CD. Results of isothermal titration calorimetry experiments confirmed that only CD2 is involved in binding to cpSRP54. The negatively charged C-terminal helix in CD2 possibly plays a crucial role in the cpSRP54-cpSRP43 interaction