[Characteristics of IgH-CDR3 repertoire of peripheral B cells in a patient with primary biliary cholangitis: a preliminary study using high-throughput sequencing].

Objective: To analyze the characteristics of immunoglobulin heavy chain complementarity-determining region (IgH-CDR3) repertoire of peripheral B cells in a patient with primary biliary cholangitis (PBC) and to investigate the diversity of the immune system. Methods: Arm-PCR was used to amplify the IgH-CDR3 region of circulating B cells isolated from a PBC patient, and high-throughput sequencing was used to analyze the amplified product. The characteristics of immune repertoire were analyzed by bioinformatics. Results: In total, 329219 sequence reads were generated from the sample, with 325540 total CDR3 sequences and 72774 distinct CDR3 sequences, and the D50 of IGH-CDR3 was 7.7. The dominant CDR3 length of the sample was 45 nt (9.6%); the N addition with the highest frequency ranged from 13 to 14 nt (5.25%); the J trimming with the highest frequency was 0 nt (12.7%); the three most frequent V alleles were V4-59 (9.5%), V3-23 (8.1%), and V1-69 (6.4%). Conclusion: The diversity of IgH-CDR3 repertoire is relatively low in this patient with PBC, with several B-cell clonal expansions. The specificity needs to be further verified after increasing the sample size.

Fabrication and performance of a medium-dependent SiO2/Si photonic heterostructure device.

An optical device based on a photonic bandgap heterostructure is designed, fabricated, and characterized. The sample contains two sets of Si/SiO2 photonic crystals with different periods. When the device is working in air, it reflects omnidirectionally both TE and TM mode lights at the wavelength near 1.3 microm. The reflectivity measured in the bandgap is higher than 98% in an incident angle range 0 degrees-70 degrees. When the device is surrounded with silica (n > 1.33), it permits the total transmission for the TM mode but prevents the TE mode from propagating, thus behaving as a polarization splitter. The experimental extinction ratio of the reflected TE/TM is approximately 31 dB. The uniformity of the device performance over a large sample area is demonstrated.