Abstract Offshore installations activities entail the hazard of explosion accidents with potentially severe consequences to safety of workers, integrity of system, pollution of the environment, and economic losses. Blast walls are generally used for the purpose of reducing the explosion consequences. This study introduce a new concept of blast wall (perforated blast wall) which can disrupt loaindg pressure during the explosion. A dynamic finite element analysis was performed to investigate the effects of the geometric characteristics on the performance of perforated blast walls. A series of computations were performed varying with opening size, plate thickness and opening layout associated with Blockage Ratio. A proposal formula was derived as a function of those design parameters for easily expecting the dynamic structural response characteristics.

Abstract Hydrocarbon explosions are one of most hazardous events for workers on offshore platforms. To protect structures against explosion loads, corrugated blast walls are typically installed. However, the profiles of real explosion loads are quite different depending on the congestion and confinement of Topside structures. As the level of congestion and confinement increases, the explosion load increases by up to 8 bar, and the rising time of the load decreases. This study primarily aims to investigate the structural behavior characteristics of corrugated blast walls under different types of explosion loadings. Four loading shapes were applied in the structural response analysis, which utilized a dynamic nonlinear finite element method.

As part of our ongoing search for bioactive constituents of natural Korean medicinal resources, a bioassay-guided fractionation and chemical investigation of the MeOH extract of Raphanus sativus (Brassicaceae) seeds resulted in the isolation and identification of fifteen compounds, including a new phenolic compound. The structure of the new compound was determined by extensive spectroscopic analysis and the Mosher's method. One of the compounds has been recently reported as a synthetic product. Some compounds showed moderate antiproliferative activities against the tumor cell lines A549, SK-OV-3, SK-MEL-2, and HCT-15 with IC50 values in the range of 5.62 to 28.88 μM. Moreover, the anti-neuroinflammatory activities of the isolates were determined by measuring the nitric oxide (NO) levels in the medium using murine microglia BV-2 cells. With exception of one specific compound, all the others inhibited the lipopolysaccharide (LPS)-stimulated NO production (IC50 values < 200 μM).

A study on the finite element (FE) analysis of laminated composite plates is described in this paper. In order to investigate structural behavior of laminated composite plates, a four-node laminated plate element is newly developed by using a higher order shear deformation theory (HSDT). In particular, assumed natural strains are introduced in the present FE formulation to alleviate the locking phenomenon. Several numerical examples are carried out and its results are then compared with the existing reference solutions. It is found to be that the proposed FE is very effective to remove the locking phenomenon and produces reliable numerical solutions for most laminated composite plate structures.

Purpose Endoscopic urethrotomy is an alternative method in treatment of urethral stricture. However, it have high recurrence rate because of the remained fibrotic tissue. Removal of the fibrotic tissue can maintain the patency of the urethral lumen after the procedure. We report the therapeutic efficacy of our initial experience using pediatric resectoscope for treating anterior urethral stricture in 16 cases. Materials and Methods From January 2009 to April 2011, transurethral resection with pediatric resectoscope was primarily performed on 16 patients with anterior urethral stricture. Retrograde urethrography, uroflowmetry, postvoid residual volume, IPSS score and QoL score were performed preoperatively. We used 11.5Fr pediatric resectoscope (Wolf) and monopolar electrosurgical generator. The stricture was incised under vision at the 12 o'clock location or the site of maximum scar tissue or narrowing in asymmetric strictures for working space. After incision, transurethral resection with pediatric resectoscope was performed to all scar tissues. Monopolar cutting current was set on 45 watt and coagulation current was set on 30 watt, fulgurate mode. Postoperatively, drainage of the bladder was performed for 7 days using an 18F latex catheter. Patients were followed up by IPSS score, QoL score, uroflowmetry and postvoid residual volume. Results Successful results without recurrence were achieved in 11 of 16patients. Postoperative urethral dilation had been performed average 2.4 times (0∼6 times). When we classified the results by etiology, the number of successful results in strictures with a trauma, iatrogenic, or unknown cause was 5 (7/11), 3 (3/4) and 1 (1/1), respectively. In 5 patients who failed treatment, we repeated transurethral resection with pediatric resectoscope in 1 patient, and periodic urethral dilation in 4 patients. No operative complications occurred in any patients. Conclusions Transurethral resection with pediatric resectoscope is an effective therapeutic method for anterior urethral stricture. More long-term follow-up and large scale studies are needed to confirm the efficacy of this procedure.

ObjectivesTo evaluate the effect of mesenchymal stem cells (MSCs) and MSCs mixed with Matrixen as a cell carrier on the erectile dysfunction caused by bilateral cavernous nerve crushing injury.Materials and MethodsWhite male Sprague-Dawley rats were divided into 4 groups: sham-operated control group (n = 5), bilateral cavernous nerve crushing group (BCNC group, n = 10), BCNC administered with MSCs group (n = 10,1×106 in 20 µL), BCNC administered with Matrixen group (n = 10.1×106 in 20 µL), BCNC administered with MSCs/Matrixen group (n = 10.1×106 in 20 µL). After functional assessment at 4 weeks, major pelvic ganglion (MPG) and penile tissue were collected. Immunofluorescent staining of MPG was performed with PKH26 and Tuj1. Western blot analysis of endothelial nitric oxide synthase (eNOS) and neuronal nitric oxide synthase (nNOS) were done in corpus cavernosum.ResultsICP/MAP ratios of BCNC with MSCs and MSCs/Matrixen groups were significantly increased compared with BCNC and BCNC with Matrixen group. Moreover, ICP/MAP ratios of MSCs/Matrixen group were significantly increased compared with BCNC with MSCs group. In MPG, the more implantation of MSCs and increased expression of nerve cells were observed in MSCs/Matrixen group compared with BCNC with MSCs group. Significant increase expression of eNOS and nNOS was also noted in BCNC with MSCs/Matrixen group.ConclusionThe erectile function was more preserved in MSCs/Matrixen group compared with the administration of MSCs alone in the rats with bilateral cavernous nerve crushing injury. Therefore, we consider that the use of transplant cell carrier such as Matrixen may help the implantation of MSCs and improve the therapeutic effect of MSCs.

OBJECTIVE: To investigate the relationships between 2nd to 4th digit ratio (digit ratio) and prostate cancer detection rate and biopsy findings, including Gleason score. MATERIALS AND METHODS: In 770 consecutive men aged 40 years or older that presented with lower urinary tract symptoms (LUTS), right hand 2nd and 4th digit lengths were measured prior to PSA determinations, DRE and transrectal ultrasonography (TRUS). Among these, 166 men with a prostate specific antigen (PSA) level ≥ 3 ng/mL or abnormal digit rectal examination (DRE) prospectively underwent prostate biopsies. The relationship between digit ratio and prostate cancer detection rate and biopsy findings was investigated. RESULTS: The study subjects were allocated to two groups by digit ratio (group A: digit ratio < 0.95; n = 420; group B: digit ratio ≥ 0.95; n = 350). Despite similar biopsy rates (22.4% vs. 20.6%, p = 0.544), group A had higher cancer detection rate (46.8% (44/94) vs. 23.6% (17/72), p = 0.002; OR = 2.847, 95% CI = 1.445-5.610). When we analyzed 408 positive biopsy cores (group A: digit ratio < 0.95, n = 282; group B: digit ratio ≥ 0.95, n = 126), group A had higher percentage of core cancer volume (46.7% vs. 37.1%, p = 0.005) and more biopsy cores with high Gleason score (sum of Gleason score ≥ 9: 18/282 (6.4%) vs. 1/126 (0.8%), p = 0.010; primary Gleason score = 5: 12/282 (4.3%) vs. 0/126 (0.0%), p = 0.021). CONCLUSIONS: A lower digit ratio is related to an increased detection rate of prostate cancer, a high percentage of core cancer volume and a high Gleason score.