Solution structure of the DNA-binding domain of RPA from Saccharomyces cerevisiae and its interaction with single-stranded DNA and SV40 T antigen

Replication protein A (RPA) is a three-subunit complex with multiple roles in DNA metabolism. DNA-binding domain A in the large subunit of human RPA (hRPA70A) binds to single-stranded DNA (ssDNA) and is responsible for the species-specific RPA–T antigen (T-ag) interaction required for Simian virus 40 replication. Although Saccharomyces cerevisiae RPA70A (scRPA70A) shares high sequence homology with hRPA70A, the two are not functionally equivalent. To elucidate the similarities and differences between these two homologous proteins, we determined the solution structure of scRPA70A, which closely resembled the structure of hRPA70A. The structure of ssDNA-bound scRPA70A, as simulated by residual dipolar coupling-based homology modeling, suggested that the positioning of the ssDNA is the same for scRPA70A and hRPA70A, although the conformational changes that occur in the two proteins upon ssDNA binding are not identical. NMR titrations of hRPA70A with T-ag showed that the T-ag binding surface is separate from the ssDNA-binding region and is more neutral than the corresponding part of scRPA70A. These differences might account for the species-specific nature of the hRPA70A–T-ag interaction. Our results provide insight into how these two homologous RPA proteins can exhibit functional differences, but still both retain their ability to bind ssDNA

Development of a Chaff Dispense Program for Target Tracking Radar Deception

This study aims to develop an appropriate chaff dispensing program to deceive the target tracking radar (TTR) effectively. Chaff is a countermeasure commonly used by fighter aircraft to deceive TTR. However, there has been a lack of methodology for calculating chaff dispense programs that take into account the specific characteristics of the fighter, chaff, and TTR. This study proposes a methodology that considers these variables to calculate chaff dispense programs and addresses this gap. The proposed method is demonstrated through TESS engagement, which shows its effectiveness in various engagement situations

Application of Ganz Surgical Hip Dislocation Approach in Pediatric Hip Diseases

Ganz surgical hip dislocation is useful in the management of severe hip diseases, providing an unobstructed view of the femoral head and acetabulum. We present our early experience with this approach in pediatric hip diseases. Twenty-three hips of 21 patients with pediatric hip diseases treated using the Ganz surgical hip dislocation approach were the subjects of this study. The average age at the time of surgery was 15.7 years. There were 15 male and 6 female patients who were followed for an average of 15.1 months (range, 6 to 29 months). Diagnoses included hereditary multiple exostoses in 9 hips, slipped capital femoral epiphysis in 7, Legg-Calvé-Perthes disease in 4, osteoid osteoma in 1, pigmented villonodular synovitis in 1, and neonatal septic hip sequelae in 1. Medical records were reviewed to record diagnoses, principal surgical procedures, operative time, blood loss, postoperative rehabilitation, changes in the range of hip joint motion, and complications. Femoral head-neck osteochondroplasty was performed in 17 patients, proximal femoral realignment osteotomy in 6, open reduction and subcapital osteotomy for slipped capital femoral epiphysis (SCFE) in 2, core decompression and bone grafting in 2, hip distraction arthroplasty in 2, and synovectomy in 2. Operative time averaged 168.6 minutes when only osteochondroplasty and/or synovectomy were performed. Hip flexion range improved from a preoperative mean of 84.7 degrees to a mean of 115.0 degrees at the latest follow-up visit. Early continuous passive motion and ambulation were stressed in rehabilitation. No avascular necrosis of the femoral head was noted up to the time of the latest follow-up visit, except for in one SCFE patient whose surgical intervention was delayed for medical reasons. Ganz surgical hip dislocation provides wide exposure of the femoral head and neck, which enables complete and precise evaluation of the femoral head and neck contour. Hence, the extensive impinging bump can be excised meticulously, and the circulation of the femoral head can be monitored during surgery. The Ganz procedure was useful in severe pediatric hip diseases and allowed for quick rehabilitation with fewer complications.Y

A Surgically Treated Case of Chronic Necrotizing Aspergillosis with Pleural Invasion

Aspergillus is a ubiquitous fungus and can cause many levels of disease severity. Chronic necrotizing aspergillosis is a rare disease and few cases have been reported in Korea. We experienced a case of pleural aspergillosis that was treated successfully with medical and surgical interventions. The 52-year-old man who was diagnosed with chronic necrotizing pulmonary aspergillosis underwent surgical treatment including a lobectomy, decortication, and myoplasty. The patient was also medically treated with amphotericin B followed by voriconazole. Pleural irrigation with amphotericin B was also performed. A multi-dimensional approach should be considered for treating chronic necrotizing pulmonary aspergillosis

Tip-Enhanced Raman Scattering Imaging of Two-Dimensional Tungsten Disulfide with Optimized Tip Fabrication Process

We successfully achieve the tip-enhanced nano Raman scattering images of a tungsten disulfide monolayer with optimizing a fabrication method of gold nanotip by controlling the concentration of etchant in an electrochemical etching process. By applying a square-wave voltage supplied from an arbitrary waveform generator to a gold wire, which is immersed in a hydrochloric acid solution diluted with ethanol at various ratios, we find that both the conical angle and radius of curvature of the tip apex can be varied by changing the ratio of hydrochloric acid and ethanol. We also suggest a model to explain the origin of these variations in the tip shape. From the systematic study, we find an optimal condition for achieving the yield of similar to 60% with the radius of similar to 34 nm and the cone angle of similar to 35 degrees. Using representative tips fabricated under the optimal etching condition, we demonstrate the tip-enhanced Raman scattering experiment of tungsten disulfide monolayer grown by a chemical vapor deposition method with a spatial resolution of similar to 40 nm and a Raman enhancement factor of similar to 4,760. © The Author(s) 2017