Magnetic Flux-Based Nondestructive Evaluation Technologies for Assessing Corrosion Damage in External and Internal Post-Tensioned Tendons: Development Efforts and Evaluation Results

DTFH61-14-D-00011This report presents research work related to developing and evaluating magnetic flux-based nondestructive evaluation (NDE) technologies for detecting corrosion damage in external and internal post-tensioned (PT) tendons. For the external tendons, two types of magnetic main flux method (MMFM) systems\u2014a solenoid type and a permanent magnet type\u2014 were developed and validated in the laboratory and in the field. The solenoid-type MMFM system was the most accurate NDE method. Its lowest damage detection limit would be 0.4-percent section loss for the point measurement method and 1.0-percent section loss for the scan measurement method. The permanent-type MMFM system is suitable for locating potential problem areas containing more than 3.0-percent section loss in external PT tendons. It has more versatile applications in the field because of its simpler hardware and speedy operation. Ideally, both MMFM systems can be employed in sequence during the field investigations: the permanent magnet type identifies potentially problematic areas by quickly scanning all suspected tendons, followed by the point measurements in the suspicious areas with the solenoid type. A return flux method prototype was developed for the internal tendons. It reached the immediate goal of detecting relatively small section losses hidden in internal tendons in laboratory environments and proved its concept successfully. It could detect a section loss larger than 15.3-percent in internal mockup tendons surrounded by vertical rebars at 6.0-inch or wider spacing when the clear concrete cover was less than 7.5 inches for metal ducts and 6.5 inches for polyethylene ducts. Without interference from the vertical rebars, as little as 9.0-percent section loss could be identified at the 6.0-inch cover. However, poor results were obtained in the anchorage zone in the box girder specimen. It is recommended that the present prototype be further improved to make it a field-deployable NDE system

Activin E Controls Energy Homeostasis in Both Brown and White Adipose Tissues as a Hepatokine

Brown adipocyte activation or beige adipocyte emergence in white adipose tissue (WAT) increases energy expenditure, leading to a reduction in body fat mass and improved glucose metabolism. We found that activin E functions as a hepatokine that enhances thermogenesis in response to cold exposure through beige adipocyte emergence in inguinal WAT (ingWAT). Hepatic activin E overexpression activated thermogenesis through Ucp1 upregulation in ingWAT and other adipose tissues including interscapular brown adipose tissue and mesenteric WAT. Hepatic activin E-transgenic mice exhibited improved insulin sensitivity. Inhibin βE gene silencing inhibited cold-induced Ucp1 induction in ingWAT. Furthermore, in vitro experiments suggested that activin E directly stimulated expression of Ucp1 and Fgf21, which was mediated by transforming growth factor-β or activin type I receptors. We uncovered a function of activin E to stimulate energy expenditure through brown and beige adipocyte activation, suggesting a possible preventive or therapeutic target for obesity

Clinicopathological characteristics and treatment strategies in early gastric cancer: a retrospective cohort study

<p>Abstract</p> <p>Background</p> <p>Both endoscopic and surgical approaches are employed in the treatment of early gastric cancer (EGC). The aim of this study was to establish appropriate treatment strategies for early gastric cancer.</p> <p>Methods</p> <p>We retrospectively examined clinicopathological data of EGC patients who had undergone surgery.</p> <p>Results</p> <p>A total of 327 patients (204 males and 123 females, mean age 63.2 years) were eligible for inclusion in the study. The median follow-up period was 31 months. Of 161 mucosal (pT1a) tumors, 87 were mainly undifferentiated and 110 had an undifferentiated component. Four patients with pT1a tumors had lymph node metastases; all these tumors were signet-ring cell carcinomas and were macroscopic type 0-IIc with ulceration, and only one of them had lymphatic invasion. Among patients with submucosal tumors, four of 43 patients with pT1b1 tumors and 37 of 123 patients with pT1b2 tumors had nodal metastases. Lymph node metastases were significantly higher in mixed undifferentiated type group than differentiated type group for both groups, pT1a-pT1b1 (p = 0.0251) and pT1b2 (p = 0.0430) subgroups. Only four of 45 patients with nodal metastases were diagnosed preoperatively by computed tomography (sensitivity 8.9%, specificity 96.2%). Nine patients with pT1b tumors had recurrence after surgery, and died. The sites of initial recurrence were liver, bone, peritoneum, distant nodes, and the surgical anastomosis.</p> <p>Conclusions</p> <p>The incidence of nodal metastases was approximately 5% in undifferentiated type mucosal (pT1a) tumors, and higher in submucosal (pT1b) tumors. The sensitivity of preoperative diagnosis of nodal metastases in EGC using computed tomography was relatively low in this study. Therefore at present surgery with adequate lymphadenectomy should be performed as curative treatment for undifferentiated type EGC.</p

Visualization of torn anterior cruciate ligament using 3-dimensional computed tomography

Recently, a remnant-preserving anterior cruciate ligament (ACL) reconstruction technique has been developed. However, the pre-operative condition of remnant ACL is occasionally difficult to evaluate by magnetic resonance imaging. The purpose of this study is to evaluate the accuracy of pre-operative visualization of remnant ACL using three-dimensional computed tomography (3D-CT). The remnant ACL in 25 patients was examined by 3D-CT before ACL reconstruction surgery. Findings on 3D-CT images and arthroscopy were compared. The 3D-CT images were classified into 4 groups: Group A, remnant fibers attached to the posterior cruciate ligament (PCL); Group B, those located between the PCL and the lateral wall; Group C, those attached to the lateral wall; and Group D, no identifiable remnant fibers on the tibial side. These groups were made up of 4, 3, 9 and 9 patients, respectively. Findings on 3D-CT images were identical to those during arthroscopy in 20 of 25 cases (80%). Remnant ACL can be accurately evaluated using 3D-CT in 80% of cases of torn ACL. This novel method is a useful technique for pre-operative assessment of remnant ACL

TiNbSn stems with gradient changes of Young’s modulus and stiffness reduce stress shielding compared to the standard fit-and-fill stems

Abstract Background The difference between Young’s moduli of the femur and the stem causes stress shielding (SS). TiNbSn (TNS) stem has a low Young’s modulus and strength with gradient functional properties during the change in elastic modulus with heat treatment. The aim of this study was to investigate the inhibitory effect of TNS stems on SS and their clinical outcomes compared to conventional stems. Methods This study was a clinical trial. Primary THA was performed using a TNS stem from April 2016 to September 2017 for patients in the TNS group. Unilateral THA was performed using a Ti6Al4V alloy stem from January 2007 to February 2011 for patients in the control group. The TNS and Ti6Al4V stems were matched in shape. Radiographs were obtained at the 1- and 3-year follow-ups. Two surgeons independently checked the SS grade and appearance of cortical hypertrophy (CH). The Japanese Orthopaedic Association (JOA) scores before and 1 year after surgery were assessed as clinical scores. Results None of the patients in the TNS group had grade 3 or 4 SS. In contrast, in the control group, 24% and 40% of patients had grade 3 and 4 SS at the 1- and 3-year follow-ups, respectively. The SS grade was lower in the TNS group than in the control group at the 1- and 3-year follow-ups (p < 0.001). The frequencies of CH in both groups were no significant difference at the 1- and 3-year follow-ups. The JOA scores of the TNS group significantly improved at 1 year after surgery and were comparable to control group. Conclusion The TNS stem reduced SS at 1 and 3 years after THA compared to the proximal-engaging cementless stem, although the shapes of the stems matched. The TNS stem could reduce SS, stem loosening, and periprosthetic fractures. Trial registration: Current Controlled Trials. ISRCTN21241251. https://www.isrctn.com/search?q=21241251 . The date of registration was October 26, 2021. Retrospectively registered