Development of a Method to Predict the Bending Strength of Lumber Without Regard to Species Using X-Ray Images

Several models have been developed for predicting bending strength of lumber using X-rays, but most require species-specific classifications. However, the classification is very difficult because logs or cants can arrive without leaves or bark. This study was carried out to develop an alternative bending strength prediction model that does not lose precision when the species is unknown. The study proposes an Equivalent Density Model (EDM), in which a cross-section is quantified as equivalent density. Because the relationship between density and strength of small clear specimens is not affected by species, the EDM was expected to correlate to strength regardless of species. This model predicted the modulus of rupture in two species with R2 = 0.73, although the two were mixed. Therefore, it may be possible to predict bending strength using X-rays without classifying lumber by species

The change of QRS duration after pulmonary valve replacement in patients with repaired tetralogy of Fallot and pulmonary regurgitation

Purpose This study aimed to analyze changes in QRS duration and cardiothoracic ratio (CTR) following pulmonary valve replacement (PVR) in patients with tetralogy of Fallot (TOF). Methods Children and adolescents who had previously undergone total repair for TOF (n=67; median age, 16 years) who required elective PVR for pulmonary regurgitation and/or right ventricular out tract obstruction were included in this study. The QRS duration and CTR were measured pre- and postoperatively and postoperative changes were evaluated. Results Following PVR, the CTR significantly decreased (pre-PVR 57.2%±6.2%, post-PVR 53.8%±5.5%, P=0.002). The postoperative QRS duration showed a tendency to decrease (pre-PVR 162.7±26.4 msec, post-PVR 156.4±24.4 msec, P=0.124). QRS duration was greater than 180 msec in 6 patients prior to PVR. Of these, 5 patients showed a decrease in QRS duration following PVR; QRS duration was less than 180 msec in 2 patients, and QRS duration remained greater than 180 msec in 3 patients, including 2 patients with diffuse postoperative right ventricular outflow tract hypokinesis. Six patients had coexisting arrhythmias before PVR; 2 patients, atrial tachycardia; 3 patients, premature ventricular contraction; and 1 patient, premature atrial contraction. None of the patients presented with arrhythmia following PVR. Conclusion The CTR and QRS duration reduced following PVR. However, QRS duration may not decrease below 180 msec after PVR, particularly in patients with right ventricular outflow tract hypokinesis. The CTR and ECG may provide additional clinical information on changes in right ventricular volume and/or pressure in these patients

Evaluation of Early Bone Response to Fluoride-Modified and Anodically Oxidized Titanium Implants Through Continuous Removal Torque Analysis

PURPOSE: To compare between a bioactive and a bioinert implant with different geometries by continuous measurement of the removal torque and calculation of the angular momentum of each surfaced implant.MATERIALS AND METHODS: Six New Zealand white rabbits were used in the study. Each rabbit received 2 implants. A bioactive fluoride-modified implant with a conical connection and microthread design was inserted into one tibia, and a bioinert anodically oxidized implant with an external connection design was inserted into the other. After 2 weeks of implant insertion, the removal torque values were continuously measured according to time. Using the time-torque curve resulting from the measurements, the maximum values were determined, and the angular momenta were calculated.RESULTS: The anodically oxidized implant had significantly higher peak removal torque and angular momentum values than the fluoride-modified implant (P < 0.05).CONCLUSIONS: The impact of the fluoride-modified bioactive implant on early bone response remains unclear. Considering the angular momentum of dental implants may assist in the elucidation of the effect of implant geometry on bone response.OAIID:oai:osos.snu.ac.kr:snu2012-01/102/2008003883/3SEQ:3PERF_CD:SNU2012-01EVAL_ITEM_CD:102USER_ID:2008003883ADJUST_YN:NEMP_ID:A078517DEPT_CD:861CITE_RATE:1.05FILENAME:Implant Dent 201210 21(5) 427-32.pdfDEPT_NM:치의학과EMAIL:[email protected]_YN:YCONFIRM:

Appropriateness of rabies post-exposure prophylaxis in pediatric patients visiting the emergency department due to animal bite

Purpose To study the appropriateness of rabies post-exposure prophylaxis (rPEP) for children with animal bite who visited the emergency department (ED). Methods The study enrolled children younger than 18 years with animal bite who visited the National Medical Center ED between January 2014 and October 2017. The children’s electronic medical records were retrospectively reviewed. Data for analysis included age, sex, body parts bitten by animals, species of animals, regions where animal bites occurred, history of recent antibiotics therapy and tetanus vaccination, and justification by the 2017 Guidelines for Rabies Control in Korea and implementation of rPEP. In children who underwent unjustified rPEP or did not undergo justified one, we recorded their guardians’ opinion for or against rPEP. Results Of the 63 enrolled children, rPEP was justified for 38 children by the Korean guidelines. Of the 38 children, 35 actually underwent rPEP. Among the remaining 3 children, 2 did not undergo the prophylaxis as per the guardians’ requests. Among the 25 children whose rPEP was not justified, 8 underwent the prophylaxis. Of these 8 children, 7 did based on the guardians’ requests. Conclusion In this study, inappropriate rPEP was usually affected by the guardians’ requests, regardless of the criteria for such prophylaxis. Thus, their requests for or against rPEP should be discussed with emergency physicians who are aware of the relevant criteria to prevent occurrence of rabies or unnecessary use of medical resources

Spirulina

Skin regeneration is a complex process involving massive proliferation and alignment of cells, where there are obstacles to completion of regeneration, the main one being excessive generation of reactive oxygen species (ROS) from inflammation or infection. Spirulina, blue-green algae that has antioxidant and anti-inflammatory activities, has been used to relieve such ROS stress. In this study, Spirulina extract loaded PCL (Spirulina-PCL) nanofiber was evaluated as a cutaneous wound dressing in view of antioxidative mechanism. In addition to increasing fibroblast viability, the Spirulina extract and its dressing modulated intra- and extracellular ROS by enhancing antioxidant mechanism of fibroblast under oxidative stress. Finally, in vivo assays confirmed that Spirulina-PCL helps regenerate wounds and enhance regeneration. Taken together, the results of this study indicate that Spirulina and nanofiber have the potential for application to cutaneous wound to facilitate skin regeneration

Outcome of neonatal palliative procedure for pulmonary atresia with ventricular septal defect or tetralogy of Fallot with severe pulmonary stenosis: experience in a single tertiary center

Purpose The present study aimed to evaluate progression and prognosis according to the palliation method used in neonates and early infants aged 3 months or younger who were diagnosed with pulmonary atresia with ventricular septal defect (PA VSD) or tetralogy of Fallot (TOF) with severe pulmonary stenosis (PS) in a single tertiary hospital over a period of 12 years. Methods Twenty with PA VSD and 9 with TOF and severe PS needed initial palliation. Reintervention after initial palliation, complete repair, and progress were reviewed retrospectively. Results Among 29 patients, 14 patients underwent right ventricle to pulmonary artery (RV-PA) connection, 11 palliative BT shunt, 2 central shunt, and 2 ductal stent insertion. Median age at the initial palliation was 13 days (1–98 days). Additional procedure for pulmonary blood flow was required in 5 patients; 4 additional BT shunt operations and 1 RV-PA connection. There were 2 early deaths among patients with RV-PA connection, one from RV failure and the other from severe infection. Finally, 25 patients (86%) had a complete repair. Median age of total correction was 12 months (range, 2–31 months). At last follow-up, 2 patients had required reintervention after total correction; 1 conduit replacement and 1 right ventricular outflow tract (RVOT) patch enlargements. Conclusion For initial palliation of patients with PA VSD or TOF with severe PS, not only shunt operation but also RV-PA connection approach can provide an acceptable outcome. To select the most proper surgical strategy, we recommend thorough evaluation of cardiac anomalies such as RVOT and PA morphologies and consideration of the patient’s condition

Identification of a bioactive core sequence from human laminin and its applicability to tissue engineering

Finding bioactive short peptides derived from proteins is a critical step to the advancement of tissue engineering and regenerative medicine, because the former maintains the functions of the latter without immunogenicity in biological systems. Here, we discovered a bioactive core nonapeptide sequence, PPFEGCIWN (residues 2678e2686; Ln2-LG3-P2-DN3), from the human laminin a2 chain, and investigated the role of this peptide in binding to transmembrane proteins to promote intracellular events leading to cell functions. This minimum bioactive sequence had neither secondary nor tertiary structures in a computational structure prediction. Nonetheless, Ln2-LG3-P2-DN3 bound to various cell types as actively as laminin in cell adhesion assays. The in vivo healing tests using rats revealed that Ln2-LG3-P2-DN3 promoted bone formation without any recognizable antigenic activity. Ln2-LG3-P2-DN3-treated titanium (Ti) discs and Ti implant surfaces caused the enhancement of bone cell functions in vitro and induced faster osseointegration in vivo, respectively. These findings established a minimum bioactive sequence within human laminin, and its potential application value for regenerative medicine, especially for bone tissue engineering.OAIID:oai:osos.snu.ac.kr:snu2015-01/102/2008003883/7ADJUST_YN:YEMP_ID:A078517DEPT_CD:861CITE_RATE:8.557FILENAME:044-biomaterials 201512 73() 96-109.pdfDEPT_NM:치의학과SCOPUS_YN:YCONFIRM:

Soft, curved electrode systems capable of integration on the auricle as a persistent brain–computer interface

Recent advances in electrodes for noninvasive recording of electroencephalograms expand opportunities collecting such data for diagnosis of neurological disorders and brain–computer interfaces. Existing technologies, however, cannot be used effectively in continuous, uninterrupted modes for more than a few days due to irritation and irreversible degradation in the electrical and mechanical properties of the skin interface. Here we introduce a soft, foldable collection of electrodes in open, fractal mesh geometries that can mount directly and chronically on the complex surface topology of the auricle and the mastoid, to provide high-fidelity and long-term capture of electroencephalograms in ways that avoid any significant thermal, electrical, or mechanical loading of the skin. Experimental and computational studies establish the fundamental aspects of the bending and stretching mechanics that enable this type of intimate integration on the highly irregular and textured surfaces of the auricle. Cell level tests and thermal imaging studies establish the biocompatibility and wearability of such systems, with examples of high-quality measurements over periods of 2 wk with devices that remain mounted throughout daily activities including vigorous exercise, swimming, sleeping, and bathing. Demonstrations include a text speller with a steady-state visually evoked potential-based brain–computer interface and elicitation of an event-related potential (P300 wave)

The reliability of an easy measuring method for abutment convergence angle with a computer-aided design (CAD) system

PURPOSE. The purpose of this study was to evaluate the intra-rater reliability and inter-rater reliability of three different methods using a drawing protractor, a digital protractor after tracing, and a CAD system. MATERIALS AND METHODS. Twenty-four artificial abutments that had been prepared by dental students were used in this study. Three dental students measured the convergence angles by each method three times. Bland-Altman plots were applied to examine the overall reliability by comparing the traditional tracing method with a new method using the CAD system. Intraclass Correlation Coefficients (ICC) evaluated intra-rater reliability and inter-rater reliability. RESULTS. All three methods exhibited high intra-rater and inter-rater reliability (ICC>0.80, P<.05). Measurements with the CAD system showed the highest intra-rater reliability. In addition, it showed improved inter-rater reliability compared with the traditional tracing methods. CONCLUSION. Based on the results of this study, the CAD system may be an easy and reliable tool for measuring the abutment convergence angle.OAIID:oai:osos.snu.ac.kr:snu2014-01/102/2008003883/3SEQ:3PERF_CD:SNU2014-01EVAL_ITEM_CD:102USER_ID:2008003883ADJUST_YN:NEMP_ID:A078517DEPT_CD:861CITE_RATE:0FILENAME:j adv prosthodont 201406 6(3) 185-93.pdfDEPT_NM:치의학과SCOPUS_YN:NCONFIRM: