Building Information Modeling (BIM) has been one of the overwhelming trends in the worldwide. In Korea, from 2012, BIM application to the public construction projects worth more than $40 million was mandated. However, despite the policy, many public owners have hesitated to apply BIM to their projects. They generally view BIM very complex to manage and difficult to understand. While there have been diverse BIM guides as a reference, most of them have developed from BIM suppliers’ perspective involving certain deficiency in meeting the public owners’ taste. The public owners have addressed the necessity for developing an owner-oriented BIM guide on which they can understand the overall BIM procurement process thereby efficiently preparing their BIM service contracts. The main objective of this study is to develop the structure and contents guidance of the new guide to be developed that follows the public business process and mitigates the deficiency. To meet the research objective, a number of domestic and international BIM guides were analyzed and workshops were operated twice with the 12 BIM experts from the Korean construction industry. As a result of the study, a four-staged guide structure was developed consisting of the BIM service Scoping, Tendering, Executing, and Wrapping-up (STEW) guides.

Flammability was evaluated and the results showed the values of critical flux at extinguishment (CFE) as 49.5kW/㎡ on average, total heat release (Qt) as 0.21MJ on average, and peak heat release rate (Qp) as 0.66kW on average, which satisfied all of the thresholds presented by the IMO. Therefore, flame-retardant plywood, of which the flame-retardant performance was evaluated, was determined to be an applicable finishing material that satisfies fire safety standards.

In accordance with regulations set forth by the Ministry of Land, Infrastructure, and Transport in Korea regarding the "Flame Retardant Performance of Building Finishing Materials and Fire Spread Prevention Structure," it is mandated that semi-noncombustible materials have a total heat emission less than 8 MJ/m². Consequently, our study aimed to determine the ideal quantity of flame-retardant treatment required to meet the fire safety standards for Korean larch and Japanese cedar, commonly used exterior materials in Korean construction. To this end, we investigated using a cone calorimeter to observe changes in the THR (Total Heat Released) based on the AFI (Amount of Flame-retardant Impregnation) in Korean larch and Japanese cedar. Our findings indicated that the AFI needed to satisfy the prescribed flame-retardant standard of 8 MJ/m² was THR 299 MJ/m² for Korean larch and THR 526 MJ/m² for Japanese cedar. As a result, we established optimal impregnation levels of flame retardant for both species.

Due to wood’s susceptibility to fire, it is crucial to treat wood-based materials with flame retardants, especially in construction applications. This study investigated the effectiveness of various grooving types, including transverse, longitudinal, both transverse and longitudinal, and surface grooving, in enhancing larch's vacuum pressure impregnation process. The results revealed that transverse grooving provided a slightly greater impregnation advantage than longitudinal grooving. Moreover, exceptional impregnation performance was observed in larch samples subjected to both longitudinal and transverse grooving and surface grooving, exhibiting a remarkable improvement of 214,7 % compared to untreated larch.

Age-related hearing loss (ARHL) is the most common sensory disorder in the elderly. It is associated with aging and hair cell death due to oxidative stress-induced mitochondrial dysfunction. Although transgenic mice and long-term cultures for induction of aging have been used to study ARHL, there are presently no ARHL animal models stimulated by intermittent environmental change for aging. In this study, an ARHL animal model was established by inducing continuous oxidative stress to promote short-term aging of cells, determined based on the expression of the hearing loss-induced phenotype and aging related factors in the short term. The incidence of hearing loss was significantly different among the groups subjected to intermittent hypoxic environment, high-fat diet (HFD), and injection with D-galactose. Continuous oxidative stress and HFD were factors that accelerated cellular aging. Increase in UCP2 affected oxidative stress and mitochondrial dysfunction. CDH23, SLC26A4, KCNQ4, Myo7a, and Myo6, which are ARHL-related factors, were modified by oxidative stress in cells of the hearing organ. We found that intermittent hypoxic, HFD, and galactose injection accelerated cellular aging in the short term. Thus, we anticipate that the development of this hearing loss animal model, which reflects intermittent environmental changes, will benefit future research on ARHL.

Electrospun nanofiber-supported thin film composite membranes are among the most promising membranes for seawater desalination via forward osmosis. In this study, a high-performance electrospun polyvinylidenefluoride (PVDF) nanofiber-supported TFC membrane was successfully fabricated after molecular layer-by-layer polyelectrolyte deposition. Negatively-charged electrospun polyacrylic acid (PAA) nanofibers were deposited on electrospun PVDF nanofibers to form a support layer consisted of PVDF and PAA nanofibers. This resulted to a more hydrophilic support compared to the plain PVDF nanofiber support. The PVDF-PAA nanofiber support then underwent a layer-by-layer deposition of polyethylenimine (PEI) and PAA to form a polyelectrolyte layer on the nanofiber surface prior to interfacial polymerization, which forms the selective polyamide layer of TFC membranes. The resultant PVDF-LbL TFC membrane exhibited enhanced hydrophilicity and porosity, without sacrificing mechanical strength. As a result, it showed high pure water permeability and low structural parameter values of 4.12 Lm⁻²h⁻¹bar⁻¹ and 221 µm, respectively, significantly better compared to commercial FO membrane. Layer-by-layer deposition of polyelectrolyte is therefore a useful and practical modification method for fabrication of high performance nanofiber-supported TFC membrane.

Claudin-18.2 (CLDN18.2) is specifically expressed in pancreatic precancerous lesions and pancreatic ductal adenocarcinoma (PDAC). We assessed clinical characteristics of patients with CLDN18.2 overexpressing pancreatic cancer to identify patients who might benefit from CLDN18 targeted treatment. 130 patients with surgically resected PDAC were investigated the immunohistochemical expression of claudin-18 (CLDN18). The CLDN18 staining intensities (0-3+) and relative proportion of positive tumor cells were analyzed by two independent raters. Tumor as positive for CLDN18 expression was defined as ≥80% of tumor cells with 2+ or 3+ staining intensity on CLDN18 immunohistochemical assay. Positive CLDN18 expression was present in 41/130 (31.5%) surgically resected PDAC and the relative proportion of positive tumor cells and the staining intensity were directly correlated (p < 0.001). Positive CLDN18 expression was significantly associated with well-differentiated tumor (p<0.001) and less regional node involvement (p=0.045). The positive CLDN18 expressing group showed no statistical difference in median overall survival (17.4 months vs. 20.6 months, p=0.770) compared to negative CLDN18 expressing group. Distant nodal metastasis was more frequent in positive CLDN18 expressing group (p=0.011). CLDN18 is frequently expressed in PDAC, and high CLDN18 expressing PDAC showed some different clinicopathologic characteristics. High CLDN18 expression was not associated with prognosis in patients with surgically resected PDAC.

Inflammation is a natural protective process through which the immune system responds to injury, infection, or irritation. However, hyperinflammation or long-term inflammatory response can cause various inflammatory diseases. Although idebenone was initially developed for the treatment of cognitive impairment and dementia, it is currently used to treat various diseases. However, its anti-inflammatory effects and regulatory functions in inflammatory diseases is yet to be elucidated. Therefore, this study aimed to investigate the anti-inflammatory effects of idebenone in cecal ligation puncture-induced sepsis and lipopolysaccharide-induced systemic inflammation. Murine models of cecal ligation puncture-induced sepsis and lipopolysaccharide-induced systemic inflammation were generated, followed by treatment with various concentrations of idebenone. Additionally, lipopolysaccharide-stimulated macrophages were treated with idebenone to elucidate its anti-inflammatory effects at the cellular level. Idebenone treatment significantly improved survival rate, protected against tissue damage, and decreased the expression of inflammatory enzymes and cytokines in mice models of sepsis and systemic inflammation. Additionally, idebenone treatment suppressed inflammatory responses in macrophages, inhibited the NF-κB signaling pathway, reduced reactive oxygen species and lipid peroxidation, and normalized the activities of antioxidant enzyme. Idebenone possesses potential therapeutic application as a novel anti-inflammatory agent in systemic inflammatory diseases and sepsis.

Anesthetics reduce cardiac functions and lower blood pressure (BP), potentially causing excessive BP reduction in dehydrated patients or those with heart conditions, such as coronary artery disease (CAD). Considering the increased prevalence of cardiovascular disease with age, anesthesiologists must be cautious about BP reduction during general anesthesia in older adults. In the present case, an undiagnosed CAD patient in a hypovolemic state experienced a significant systolic blood pressure drop to the 50s during propofol and sevoflurane anesthesia. Despite the use of vasopressors, excessive hypotension persisted, leading to anesthesia suspension. Subsequent cardiac examinations, including computed tomography heart angio and calcium score, and coronary angiogram, revealed a near total occlusion of the left main coronary artery and the formation of collateral circulation. After 5 days of hydration and anticoagulation medications and confirmation of normovolemic state, general anesthesia was attempted again and successfully induced; a normal BP was maintained throughout the surgery. Thus, it is important to conduct a thorough cardiac evaluation and maintain normovolemia for general anesthesia in older adults.

There are several causes of hypoxia during and after surgery, and atelectasis is a common symptom that occurs during surgery. In particular, elderly patients are more vulnerable to hypoxia due to their existing lung diseases or respiratory muscle weakness. This study presents the cases of two elderly patients who developed hypoxia during total hip arthroplasty under general anesthesia. Positive end expiratory pressure, recruitment maneuver, and increased fraction of inspired oxygen improved hypoxia only temporarily, and patients’ oxygen saturation level again dropped to 79%–80%. We suspected that hypoxia was caused by atelectasis and, therefore, re-sumed spontaneous respiration. Thereafter, both the patients showed an improvement in hypoxia. Intraopera-tive hypoxia that is suspected to be caused by atelectasis can be improved by securing sufficient lung volume for respiration through increased muscle tone with spontaneous respiration