Experimental Investigation for Tensile Performance of GFRP-Steel Hybridized Rebar

Tensile performance of the recently developed “FRP Hybrid Bar” at Korea Institute of Civil Engineering and Building Technology (KICT) is experimentally evaluated by the authors. FRP Hybrid Bar is introduced to overcome the low elastic modulus of the existing GFRP bars to be used as a structural member in reinforced concrete structures. The concept of material hybridization is applied to increase elastic modulus of GFRP bars by using steel. This hybridized GFRP bar can be used in concrete structures as a flexural reinforcement with a sufficient level of elastic modulus. In order to verify the effect of material hybridization on tensile properties, tensile tests are conducted. The test results for both FRP Hybrid Bar and the existing GFRP bars are compared. The results indicate that the elastic modulus of FRP Hybrid Bar can be enhanced by up to approximately 250 percent by the material hybridization with a sufficient tensile strength. To ensure the long-term durability of FRP Hybrid Bar to corrosion resistance, the individual and combined effects of environmental conditions on FRP Hybrid Bar itself as well as on the interface between rebar and concrete are currently under investigation

Subscapular and Pectoralis Major Sparing Deltopectoral Approach for Reverse Total Shoulder Arthroplasty

In reverse ball shoulder replacement, surgery is usually performed using a deltopectoral approach or an anterosuperior transdeltoid approach. The deltopectoral approach is to incise the pectoralis major to upper 1/3 to 1/2, and subscapularis tendon should be removed at the lesser tuberosity of the humerus. This approach has the problem of breaking the shoulder deltoid instead of incising the rotator cuff. Therefore, we report a detailed procedure of reverse ball shoulder replacement using approach without incision of the pectoralis major muscle and subscapularis muscle

Design, Analysis and Empirical Researches for Solar Heat Collecting System based on Flat Mirrors Combination

There has been a dramatic increase of research on energy production using solar energy. This research aims to examine development of concentrating solar collector that is related to mid-high solar energy field. Although the use of dish type solar thermal system has been common in the existing high-efficiency collector technology, several problems have been raised. In order to solve these issues, the frame has been designed as flat plate type with Fresnel lens and the structural stability has been proved by analysis. Furthermore, the experiment that checks collectorrsquos temperature has been performed for the correct works of the stirling engine

Inter- and Intra-observer Reliability of MRI for Lumbar Lateral Disc Herniation

Background: The authors analyzed inter- and intra-observer agreement with respect to interpretation of simple magnetic resonance T1- and T2-weighted axial and sagittal images for the diagnosis of lumbar lateral disc herniation, including foraminal and extraforaminal disc herniations.Methods: Forty-two patients in whom lumbar lateral disc herniation was suspected or confirmed by simple magnetic resonance imaging at one institute between May 2003 and December 2004 were included. The magnetic resonance images consisting of T1- and T2-weighted axial and sagittal images, and these were reviewed blindly and independently by three orthopaedic spine surgeons in a random manner. The images were interpreted as positive or negative for lateral disc herniation on 2 different occasions 3 months apart. Results were analyzed using Cohens kappa statistic, and strengths of agreements were determined using the Landis and Koch criteria.Results: The kappa values for inter-observer agreement averaged 0.234 (0.282, 0.111, and 0.308 respectively) on the first occasion, and 0.166 (0.249, 0.111, and 0.137 respectively) on the second occasion, with an overall mean value of 0.200. Thus, the strength of agreement was only slight-to-fair according to the Landis and Koch criteria. Kappa values for intra-observer agreement averaged 0.479 (0.488, 0.491, and 0.459 respectively), indicating moderate agreement.Conclusions: The present study indicates that simple magnetic resonance imaging is not a reliable imaging modality for diagnosing lumbar lateral disc herniation. Another imaging study with improved diagnostic values should be developed to diagnose this pathologic finding.Keywords: Lumbar lateral disc herniation, Inter-observer reliability, Intra-observer reliability, Magnetic resonance imagingOAIID:oai:osos.snu.ac.kr:snu2009-01/102/0000004226/1SEQ:1PERF_CD:SNU2009-01EVAL_ITEM_CD:102USER_ID:0000004226EMP_ID:A076317DEPT_CD:801FILENAME:E019T_CiOS-2009_Kim_Inter-and Intra-observer Reliability of MRI for Lumbar.pdfDEPT_NM:의학과EMAIL:[email protected]_YN:NCONFIRM:YCONFIRM:

Factors associated with administration of analgesics for children with forearm fracture

Purpose Analgesia is essential for the treatment of children’s fracture. We aimed to investigate the factors associated with administration of analgesics in children with forearm fracture. Methods We retrospectively reviewed medical records of children (< 20 years) with forearm fracture who visited 2 tertiary hospital emergency departments from 2014 to 2015. We analyzed factors, such as gender, age, whether the mother accompanied the visit, visiting time and route, mechanism of injury, duration of symptoms, complicated fracture, manual reduction, surgery, and type and route of analgesics. We also performed logistic regression analysis to identify the factors associated with administration of analgesics. Results Of 179 children with forearm fracture, 48 (26.8%) were administered analgesics. These children showed older age, shorter duration of symptoms, and more frequent visit with their mothers, visit during the day, use of emergency medical services, and surgery. After logistic regression analysis, we found use of emergency medical service (adjusted odds ratio [OR], 8.73; 95% confidence interval [CI], 3.16-24.08; P < 0.001), visit with the mother (OR, 6.23; 95% CI, 1.68-23.09; P = 0.006), age (OR, 1.18; 95% CI, 1.05-1.32; P = 0.004), and duration of symptoms (OR, 0.99; 95% CI, 0.986-0.999; P = 0.035) as the factors associated with administration of analgesics. Conclusion The factors associated with administration of analgesics might be communicating skill-related factors, such as older age and shorter duration of symptoms. Children with poor communicating skill may need more aggressive analgesia in the emergency department

Prognostic value of low muscle mass at the 12th thoracic vertebral level in multiple myeloma treated with transplantation: CAREMM-2101 study

PURPOSEAutologous hematopoietic stem cell transplantation (ASCT) has been introduced as a standard treatment for newly diagnosed multiple myeloma (NDMM) following novel agent-based induction chemotherapy. This study investigated whether pre-ASCT low muscle mass evaluated using the paraspinal muscle index (PMI) at the 12th thoracic vertebra (T12) level is a reliable prognostic marker in NDMM after chemotherapy.METHODSA multi-center registry database was retrospectively analyzed. Between 2009 and 2020, 190 patients with chest computed tomography images underwent frontline ASCT following induction therapy. The PMI was defined as the value of the paraspinal muscle area at the T12 level divided by the square of the patient’s height. The cut-off value indicating a low muscle mass was sex-specific, using the lowest quintiles.RESULTSOf the 190 patients, 38 (20%) were in the low muscle mass group. The low muscle mass group had a lower 4-year overall survival (OS) rate than the non-low muscle mass group (68.5% vs. 81.2%; P = 0.074). The median progression-free survival (PFS) in the low muscle mass group was significantly shorter compared with the non-low muscle mass group (23.3 months vs. 29.2 months; P = 0.029). The cumulative incidence of transplant-related mortality (TRM) was significantly higher in the low muscle mass group than in the non-low muscle mass group (4-year probability of TRM incidence, 10.6% vs. 0.7%; P < 0.001). In contrast, no significant difference in the cumulative incidence of disease progression was found between the two groups. Multivariate analysis revealed that low muscle mass was associated with significant negative outcomes for OS [(hazard ratio (HR): 2.14; P = 0.047], PFS (HR: 1.78; P = 0.012), and TRM (HR: 12.05; P = 0.025).CONCLUSIONParaspinal muscle mass may have a prognostic role in NDMM patients who undergo ASCT. Patients with low paraspinal muscle mass have lower survival outcomes compared to non-low muscle mass group

Extreme Duplication-type, Nonseparated Fenestration of the Basilar Artery in a Patient with Pontine Infarction: Confirmation with Virtual Arterial Endoscopy

We present a case of a 55-year-old woman with pontine infarction and fenestration of the basilar artery that was demonstrated using virtual endoscopy. The patient had motor weakness of the right side with sudden onset. Diffusion- and T2-weighted MR images revealed high signal intensities in the left pontine regions, and an MR angiographic examination showed the double-lumen sign of the basilar artery. An extensive duplication-type, nonseparated fenestration of the basilar artery was diagnosed by virtual endoscopy and craniocaudal communications with discrete openings were observed. We report a case of a patient with basilar artery fenestration and associated brainstem infarction

High Lithium Ion Transport Through rGO-Wrapped LiNi0.6Co0.2Mn0.2O2 Cathode Material for High-Rate Capable Lithium Ion Batteries

In this work, we show an effective ultrasonication-assisted self-assembly method under surfactant solution for a high-rate capable rGO-wrapped LiNi0.6Co0.2Mn0.2O2 (Ni-rich cathode material) composite. Ultrasonication indicates the pulverization of the aggregated bulk material into primary nanoparticles, which is effectively beneficial for synthesizing a homogeneous wrapped composite with rGO. The cathode composite demonstrates a high initial capacity of 196.5 mAh/g and a stable capacity retention of 83% after 100 cycles at a current density of 20 mA/g. The high-rate capability shows 195 and 140 mAh/g at a current density of 50 and 500 mA/g, respectively. The high-rate capable performance is attributed to the rapid lithium ion diffusivity, which is confirmed by calculating the transformation kinetics of the lithium ion by galvanostatic intermittent titration technique (GITT) measurement. The lithium ion diffusion rate (DLi) of the rGO-wrapped LiNi0.6Co0.2Mn0.2O2 composite is ca. 20 times higher than that of lithium metal plating on anode during the charge procedure, and this is demonstrated by the high interconnection of LiNi0.6Co0.2Mn0.2O2 and conductive rGO sheets in the composite. The unique transformation kinetics of the cathode composite presented in this study is an unprecedented verification example of a high-rate capable Ni-rich cathode material wrapped by highly conductive rGO sheets