Endoscopic Submucosal Dissection of a Colonic Calcifying Fibrous Tumor

A 49-year-old woman was referred to our hospital for further treatment due to the suspicion of a submucosal tumor in a routine screening colonoscopy. On colonoscopy, a 1-cm sized subepithelial mass with normal overlying mucosa in the hepatic flexure was found. Endoscopic ultrasonography (EUS) showed a homogenous hypoechoic lesion arising from the second and third layer. We were unable to make a final diagnosis because the lesion showed a small tumor with atypical macroscopic morphology including EUS findings. Therefore, endoscopic submucosal dissection was performed for the diagnostic treatment of the tumor. Submucosal dissection was performed just above the muscle layer, and the tumor was removed completely and reliably without any acute complications such as perforation. Based on histopathological findings, we diagnosed a benign, calcifying fibrous tumor (CFT). The present case is the first report of successful endoscopic diagnosis and treatment of colonic CFT mimicking a submucosal tumor

Effect of rhBMP-2 applied with a 3D-printed titanium implant on new bone formation in rabbit calvarium

Objective: This study sought to compare the biocompatibility of a three-dimensional (3D)-printed titanium implant with a conventional machined titanium product, as well as the effect of such implant applied with recombinant human Bone Morphogenetic Protein Type 2 (rhBMP-2) for guided bone regeneration. Methodology: Disk-shaped titanium specimens fabricated either by the conventional machining technique or by the 3D-printing technique were compared by MC3T3-E1 cells cytotoxicity assay. New bone formation was evaluated using a rapid prototype titanium cap applied to the calvaria of 10 rabbits, which were divided into two groups: one including an atelopeptide collagen plug on one side of the cap (group I) and the other including a plug with rhBMP-2 on the other side (group II). At six and 12 weeks after euthanasia, rabbits calvaria underwent morphometric analysis through radiological and histological examination. Results: Through the cytotoxicity assay, we identified a significantly higher number of MC3T3-E1 cells in the 3D-printed specimen when compared to the machined specimen after 48 hours of culture. Moreover, morphometric analysis indicated significantly greater bone formation at week 12 on the side where rhBMP-2 was applied when evaluating the upper portion immediately below the ca p. Conclusion: The results suggest that 3D-printed titanium implant applied with rhBMP-2 enables new bone formation

Giant cell angiofibroma of gingiva in tuberous sclerosis complex: a case report and literature review

Abstract Background Tuberous sclerosis complex (TSC) is a rare, complex genetic disorder characterized by hamartomas and neoplastic lesions in various organ systems. With the development of radiology and gene testing, the diagnostic criteria for TSC were updated in 2012 at the International Consensus Conference. Intraoral fibromas have long been associated with TSC. However, the incidence of giant cell angiofibroma (GCA) in TSC patients is extremely rare. Here, we report the first case of GCA in the gingival tissue of a patient with TSC. Case presentation A 41-year-old woman first visited the Department of Oral and Maxillofacial Surgery, Chonnam National University Dental Hospital, complaining of gingival enlargement. Clinical examination revealed several manifestations associated with TSC, including intraoral fibromas, facial angiofibromas, dental enamel pits, ungual fibromas, “confetti” skin lesions, hypomelanotic macules, and a shagreen patch. Intraoral examination revealed a 6.0 × 5.0 cm gingival overgrowth on the left mandible. Surgical excision was performed, and subsequent histopathological examination confirmed the diagnosis of GCA. There was no evidence of recurrence within the 24- months of surgery. Conclusions We report the first case of GCA in the gingival tissue of a patient with TSC. This report would contribute to an improved understanding of this rare disease. However, further case reports are necessary to clarify the relationship between GCA and TSC

Safety impacts of implementing median bus lane system in Seoul Metropolitan Area : vehicle-to-vehicle and vehicle-to-pedestrian crashes

In metropolitan areas, public transportation has been encouraged as a sustainable mode because they can effectively transport many people and have less impact on traffic congestion and environment. In order to increase public transportation ridership, many jurisdictions have attempted to provide improved travel time and reliability of the public transportation system. These efforts include installing transit signal priority, dedicated median/curb bus lanes, bus rapid transit, bus bypass shoulder lanes, et cetera. In Korea, dedicated median bus lanes have been installed and operated since 1996. Currently, approximately 116km of the dedicated median bus lanes on 38 corridors are operational. The implementation of the dedicated median bus lanes in Seoul Metropolitan Area have been successful as they it resulted in the increased travel speed (15 km/h to 19km/h), bus arrival time accuracy (±1 min to 2 min), and daily bus-ridership (from 5.6 million to 5.75 million). Although there have been several studies that evaluated the operational effectiveness of the exclusive bus lanes in Seoul, few studies have assessed the safety impacts. This study aims at estimating the impacts of implementing median bus lane system in Seoul Metropolitan Areas for vehicle-to-vehicle and vehicle-to-pedestrian crashes. In order to achieve the objective, a before-and-after study with comparison group method was employed and estimated crash modification factors (CMFs)

Pt-Ru Bimetallic nanoparticles loading on activated carbon fibers without using reducing agents

327-330Platinum-ruthenium(Pt-Ru) bimetallic catalyst system is being used as catalyst materials of DMFCs anode due to its high tolerance for carbon monoxide poisoning. Recently, activated carbon fiber (ACF) is reported as a useful catalyst support because it has several advantages such as high dispersion of impregnated metals and low mass transfer resistance due to its uniformly developed micropores. Therefore, Pt-Ru nanoparticles loading on ACF without using reducing agents is carried out to develop an effective bimetallic catalyst. PtCl62- and Ru3+ are impregnated on ACF, and heated up to 800°C in N2. TG, XRD, TEM and EDS analyses are carried out to confirm Pt/Ru particles loading and distribution on ACF. The amount of PtCl62- impregnation is average 75% larger than that of Ru3+ at pH upto 3.5 and increases after pH 3.5 by crossing that of PtCl62-, while Ru3+ impregnation is much affected by pH. There are uniformly distributed Pt and Ru nanoparticles, which means simple impregnation and heating the PtCl62- and Ru3+ complexes up to 400°C is enough to obtain pure Pt-Ru nanoparticles on ACF without using reducing agents

Enhanced Electrical Networks of Stretchable Conductors with Small Fraction of Carbon Nanotube/Graphene Hybrid Fillers

Carbon nanotubes (CNTs) and graphene are known to be good conductive fillers due to their favorable electrical properties and high aspect ratios and have been investigated for application as stretchable composite conductors. A stretchable Conducting nanocomposite should have a small fraction of conductive filler material to maintain stretchability. Here we demonstrate enhanced electrical networks of nanocomposites via the use of a CNT-graphene hybrid system using a small mass fraction of conductive filler. The CNT-graphene hybrid system exhibits synergistic effects that prevent agglomeration of CNTs and graphene restacking and reduce contact resistance by formation of 1D(CNT)-2D(graphene) interconnection. These effects resulted in nanocomposite materials formed of multiwalled carbon nanotubes (MWCNTs), thermally reduced graphene (TRG'), and polydirnethylsiloxane.(PDMS), which had a higher electrical conductivity compared with MWCNT/PDMS or TRG/PDMS nanocomposites until specific fraction that is sufficient to form electrical network among, conductive fillers. These nanocomposite materials maintained their electrical conductivity when 60% strained.clos

Indium Tri(isopropoxide)-Catalyzed Selective Meerwein–Ponndorf–Verley Reduction of Aliphatic and Aromatic Aldehydes

Indium tri­(isopropoxide)-catalyzed Meerwein–Ponndorf–Verley reduction of aliphatic and aromatic aldehydes in 2-propanol gave selectively the corresponding primary alcohols in good to excellent yields at room temperature. A wide range of functional groups including alkene, ether, ketone, ester, nitrile, and nitro were tolerated under the optimum reaction conditions. Chemoselective reductions were also achieved not only between aromatic aldehyde, aromatic ketone, and epoxide but also between aliphatic aldehyde and alkene

Redox-Sensitive Delivery of Doxorubicin from Nanoparticles of Poly(ethylene glycol)-Chitosan Copolymer for Treatment of Drug-Resistant Oral Cancer Cells

Reactive oxygen species (ROS)-sensitive polymer nanoparticles were synthesized for tumor targeting of an anticancer drug, doxorubicin (DOX). For this purpose, chitosan-methoxy poly(ethylene glycol) (mPEG) (ChitoPEG)-graft copolymer was synthesized and then DOX was conjugated to the backbone of chitosan using a thioketal linker. Subsequently, the chemical structure of the DOX-conjugated ChitoPEG copolymer (ChitoPEGthDOX) was confirmed via 1H nuclear magnetic resonance (NMR) spectra. Nanoparticles of the ChitoPEGthDOX conjugates have spherical shapes and a size of approximately 100 nm. Transmission electron microscopy (TEM) has shown that ChitoPEGthDOX nanoparticles disintegrate in the presence of hydrogen peroxide and the particle size distribution also changes from a monomodal/narrow distribution pattern to a multi-modal/wide distribution pattern. Furthermore, DOX is released faster in the presence of hydrogen peroxide. These results indicated that ChitoPEGthDOX nanoparticles have ROS sensitivity. The anticancer activity of the nanoparticles was evaluated using AT84 oral squamous carcinoma cells. Moreover, DOX-resistant AT84 cells were prepared in vitro. DOX and its nanoparticles showed dose-dependent cytotoxicity in both DOX-sensitive and DOX-resistant AT84 cells in vitro. However, DOX itself showed reduced cytotoxicity against DOX-resistant AT84 cells, while the nanoparticles showed almost similar cytotoxicity to DOX-sensitive and DOX-resistant AT84 cells. This result may be due to the inhibition of intracellular delivery of free DOX, while nanoparticles were efficiently internalized in DOX-resistant cells. The in vivo study of a DOX-resistant AT84 cell-bearing tumor xenograft model showed that nanoparticles have higher antitumor efficacy than those found in free DOX treatment. These results may be related to the efficient accumulation of nanoparticles in the tumor tissue, i.e., the fluorescence intensity in the tumor tissue was stronger than that of any other organs. Our findings suggest that ChitoPEGthDOX nanoparticles may be a promising candidate for ROS-sensitive anticancer delivery against DOX-resistant oral cancer cells

Effect of Hydroxyapatite Nanoparticles and Nitrogen Plasma Treatment on Osteoblast Biological Behaviors of 3D-Printed HDPE Scaffold for Bone Tissue Regeneration Applications

The need for the repair of bone defects has been increasing due to various causes of loss of skeletal tissue. High density polyethylenes (HDPE) have been used as bone substitutes due to their excellent biocompatibility and mechanical strength. In the present study, we investigated the preosteoblast cell proliferation and differentiation on the adding nano-hydroxyapatite (n-HAp) particles into HDPE scaffold and treating HDPE/n-HAp scaffolds with nitrogen (N2) plasma. The three-dimensional (3D) HDPE/n-HAp scaffolds were prepared by fused modeling deposition 3D printer. The HDPE/n-HAp was blended with 10 wt% of n-HAp particle. The scaffold surface was reactive ion etched with nitrogen plasma to improve the preosteoblast biological response in vitro. After N2 plasma treatment, surfaces characterizations were investigated using Fourier transform infrared spectroscopy, scanning electron microscopy, and atomic force microscopy. The proliferation and differentiation of preosteoblast (MC3T3-E1) cells were evaluated by MTT assay and alkaline phosphatase (ALP) activity. The incorporation of n-HAp particles and N2 plasma surface treatment showed the improvement of biological responses of MC3T3-E1 cells in the HDPE scaffolds