• Korean Journal of Bronchoesophagology
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• v.16 no.2
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• pp.126-130
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• 2010

Background: The esophageal perforation is related to high morbidity and mortality rates if the diagnosis and treatment are delayed. The aim of this study is to evaluate the affecting factors on outcome and prognosis of the patients who suffer from esophageal perforation. Material and Methods: Twenty-six patients were treated with esophageal perforation in our institute from Jan. 1992 to Feb. 2010. We retrospectively reviewed the results of treatment for esophageal perforation to understand the risk factors affecting survival in patients. Results: The subjects are 26 patients suffered with esophageal perforation and the mean age is $52{\pm}17.8$ years old. 16 esophageal perforations were caused spontaneously, 25 cases were treated surgically. The mortality rate is higher in the cases o pre-operative mediastinitis. Conclusion: The shortness time interval until the beginning of treatment should be achieved to reduce the incidence of fatal post-treatment morbidity and mortality.

• Journal of Medicine and Life Science
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• v.16 no.1
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• pp.13-16
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• 2019

In a patient with blunt abdominal trauma with small bowel injury, early diagnosis is clinically challenging due to unclear clinical symptoms and signs in the early stage of an injury. On the other hand, a delay of diagnosis of bowel disruption may lead to increased complication and mortality. The diagnostic laparoscopy is very useful for the evaluation of the small bowel injury. Laparoscopy can reduce unnecessary open surgery in a patient with blunt abdominal trauma with subtle symptoms and imprecise findings on abdominal computed tomography. Also it can prevent delay of treatment and be converted immediately to open surgery as soon as bowel damage is revealed. Furthermore, extracorporeal repair of small bowel via mini-laparotomy after a single incision diagnostic laparoscopy in a patient with traumatic small bowel perforation was a feasible and safe alternative to conventional laparoscopy. We are pleased to introduce successfully treated cases by extracorporeal repair of small bowel via mini-laparotomy after a single incision diagnostic laparoscopy in a patient with small bowel perforation after blunt trauma.

• Steel and Composite Structures
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• v.46 no.5
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• pp.709-718
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• 2023

The absence of an important portion of the web plate in steel beams with multiple circular perforations, cellular beams, causes the web plate to undergo distortions prior to and during lateral torsional buckling (LTB). The conventional LTB equations in the codes and literature underestimate the buckling moments of cellular beams due to web distortions. The present study is an attempt to develop analytical methods for estimating the elastic buckling moments of cellular beams. The proposed methods rely on the reductions in the torsional and warping rigidities of the beams due to web distortions and the reductions in the weak-axis bending and torsional rigidities due to the presence of web openings. To test the accuracy of the analytical estimates from proposed solutions, a total of 114 finite element analyses were conducted for six different standard IPEO sections and varying unbraced lengths within the elastic limits. These analyses clearly indicated that the LTB solutions in the AISC 360-16 and AS4100:2020 codes overestimate the buckling loads of cellular beams within elastic limits, particularly at shorter span lengths. The LDB solutions in the literature and the Eurocode 3 LTB solution, on the other hand, provided conservative buckling moment estimates along the entire range of elastic buckling.

• Journal of Korean Clinical Nursing Research
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• v.16 no.3
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• pp.63-71
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• 2010

Purpose: This study was conducted to evaluate the incidence and risk factors for surgical glove perforation during operation. Methods: During the month of december 2008, a total of 1,400 pairs of surgical gloves used in major operations was collected in a tertiary hospital. All gloves were examined immediately after operation using the standardized water-leak method to detect any perforation. Incidence of the glove perforation was counted according to the type of operation, operation time, the number of involved personnel, perforation sites, and the manufacturing companies. Results: Out of 2,800 gloves examined, 312 perforations were detected comprising 11.1% of samples. In terms of the type of operation, the perforation incidence varied from 5% to 20%, and the perforation rates in CS (20%) and NS (18%) (p<.001) were significantly higher than those in other departments. The 1st assistant or scrub nurse got glove perforation more frequently than the 2nd assistant or operator (p<.001). Longer operation time was associated with higher incidence of perforation evidently (p<.001). In terms of the sites, the thumb and index finger were more frequently perforated than other sites (4.1% and 3.4% respectively) without any differences between left and right side. Conclusion: Risk factors for glove perforation including the department of operation, operation time, participating personnel, and location of perforation should be taken into account to improve surgical safety.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.5
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• pp.297-303
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• 2023

A resorbable barrier membrane is commonly used for the repair of perforated sinus membranes during sinus lifting surgeries. However, repairing largescale perforations poses challenges for clinicians as the protection and isolation of graft material remain uncertain. With this technique, we aimed to prevent graft material loss and subsequent sinus-related complications using intra-sinus rigid fixation of the resorbable barrier membrane in cases with a large perforation of the sinus membrane.

• Advances in aircraft and spacecraft science
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• v.10 no.3
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• pp.257-279
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• 2023

This manuscript is dedicated to deriving the closed form solutions of free vibration of viscoelastic nanobeam embedded in an elastic medium using nonlocal differential Eringen elasticity theory that not considered before. The kinematic displacements of Euler-Bernoulli and Timoshenko theories are developed to consider the thin nanobeam structure (i.e., zero shear strain/stress) and moderated thick nanobeam (with constant shear strain/stress). To consider the internal damping viscoelastic effect of the structure, Kelvin/Voigt constitutive relation is proposed. The perforation geometry is intended by uniform symmetric squared holes arranged array with equal space. The partial differential equations of motion and boundary conditions of viscoelastic perforated nonlocal nanobeam with elastic foundation are derived by Hamilton principle. Closed form solutions of damped and natural frequencies are evaluated explicitly and verified with prestigious studies. Parametric studies are performed to signify the impact of elastic foundation parameters, viscoelastic coefficients, nanoscale, supporting boundary conditions, and perforation geometry on the dynamic behavior. The closed form solutions can be implemented in the analysis of viscoelastic NEMS/MEMS with perforations and embedded in elastic medium.

• Clinical Endoscopy
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• v.55 no.1
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• pp.95-100
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• 2022

Background/Aims: Endoscopic mucosal resection (EMR) is the primary treatment for duodenal adenomas; however, it is associated with a high risk of perforation and bleeding, especially with larger lesions. The goal of this study was to demonstrate the feasibility and safety of endoscopic suturing (ES) for the closure of mucosal defects after duodenal EMR. Methods: Consecutive adult patients who underwent ES of large mucosal defects after EMR of large (>2 cm) duodenal adenomas were retrospectively enrolled. The OverStitch ES system was employed for closing mucosal defects after EMR. Clinical outcomes and complications, including delayed bleeding and perforation, were documented. Results: During the study period, ES of mucosal defects was performed in seven patients in eight sessions (six for prophylaxis and two for the treatment of perforation). All ES sessions were technically successful. No early or delayed post-EMR bleeding was recorded. In addition, no clinically obvious duodenal stricture or recurrence was encountered on endoscopic follow-up evaluation, and no patients required subsequent surgical intervention. Conclusions: ES for the prevention and treatment of duodenal perforation after EMR is technically feasible, safe, and effective. ES should be considered an option for preventing or treating perforations associated with EMR of large duodenal adenomas.

• Clinical Endoscopy
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• v.55 no.2
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• pp.292-296
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• 2022

Iatrogenic perforations are severe complications of gastrointestinal endoscopy; therefore, their management should be adequately planned. A 77-year-old man with a history of diverticulosis underwent a colonoscopy for anemia. During the procedure, an iatrogenic perforation occurred suddenly in the sigmoid colon, near a severe angle among the numerous diverticula. Through-the-scope clips were immediately applied to treat it and close mucosal edges. Laboratory tests showed increased levels of inflammation and infection, and although there were no complaints of abdominal pain, the patient had an extremely distended abdomen. A multidisciplinary board began management based on a conservative approach. Pneumoperitoneum was treated with computed tomography-assisted drainage. After 72 hours, his intestinal canalization and laboratory tests were normal. Though this adverse event is rare, a multidisciplinary board should be promptly gathered upon occurrence, even if the patient appears clinically stable, to consider a conservative approach and avoid surgical treatment.

• Composites Research
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• v.37 no.4
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• pp.310-315
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• 2024

An auxetic structure with negative Poisson's ratio exhibits distinctive mechanical properties in contrast to conventional structures, garnering interest in various fields. However, current research has predominantly focused on the design and optimization of auxetic structures, with limited exploration of their practical applications. In this study, we utilized 3D printing technology to fabricate a soft auxetic structure with triangular shaped perforations, examining the mechanical properties based on geometric structure. Additionally, by inserting shape memory alloys into the fabricated soft auxetic structure, we achieved active two-dimensional deformations and confirmed its selective object permeability. This technology holds the potential to have far-reaching implications across a broad spectrum of industries.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.3
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• pp.27-33
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• 2009

A computational study has been performed out to evaluate the effect of a vertical porous barrier on the pressure oscillations in a supersonic cavity. The porous barriers with different perforations were vertically installed into a rectangular cavity at Mach numbers 1.50, 1.83 and 2.50. TVD finite difference MUSCL scheme was employed to solve the two-dimensional, unsteady, compressible Navier-Stokes equations. The present vertical porous barrier considerably altered the characteristics of the time-dependent shear layers that occur at the upstream edge of cavity and remarkably reduced the pressure oscillations inside the supersonic cavity. The present results showed that the effectiveness of passive control using the present porous vertical barrier is dependent on Mach number and the perforation of the porous barrier.