[Isolated Small Bowel Metastasis of Endometrial Carcinoma with Resultant Jejunojejunal Intussusception: A Case Report]. / 자궁내막암의 ë‹¨ë ì†Œìž¥ ì „ì´ë¡œ 인해 ìœ ë°œëœ 공장-공장 장중첩증: 증례 ë³´ê³ .

Endometrial carcinoma is a common gynecologic malignancy; however, metastasis to the small bowel is rare. Metastatic endometrial carcinoma usually occurs through local extension rather than distant metastasis. Isolated small bowel metastasis is extremely rare; further, intussusception with resultant intestinal obstruction is not common. We report the imaging findings of a patient with isolated small bowel metastasis of endometrial carcinoma with resultant jejunojejunal intussusception.

[Imaging Findings of a Malignant Rhabdoid Tumor in the Stomach: A Case Report]. / 위에 발생한 ì• ì„± 횡문근양 ì¢ ì–‘ì˜ 영상 소견: 증례 ë³´ê³ .

A malignant rhabdoid tumor is an aggressive tumor that occurs mainly in the kidney of infants and children. When it occurs in extrarenal sites, it is referred to as an extrarenal malignant rhabdoid tumor. Although a few cases of malignant rhabdoid tumor occuring in the central nervous system, liver, brain, skin, and soft tissue have been reported, it is rarely observed in the stomach. We report the imaging findings of a malignant rhabdoid tumor of the stomach that mimicked a gastric lymphoma in a patient who presented with melena.

High-performance coaxial piezoelectric energy generator (C-PEG) yarn of Cu/PVDF-TrFE/PDMS/Nylon/Ag.

Coaxial type piezoelectric energy generator (C-PEG) nanofiber was fabricated by a self-designed continuous electrospinning deposition system. Piezoelectric PVDF-TrFE nanofiber as an electroactive material was electrospun at a discharge voltage of 9-12 kV onto a simultaneously rotating and transverse moving Cu metal wire at an angular velocity of ω g = 60-120 RPM. The piezoelectric coefficient d33 of the PVDF-TrFE nanofiber was approximately -20 pm V-1. The generated output voltage (V G) increased according to the relationship exp(-α P) (α = 0.41- 0.57) as the pressure (P) increased from 30 to 500 kpa. The V G values for ten and twenty pieces of C-PEG were V G = 3.9 V and 9.5 V at P = 100 kpa, respectively, relatively high output voltages compared to previously reported values. The high V G for the C-PEG stems from the fact that it can generate a fairly high V G due to the increased number of voltage collection points compared to a conventional two-dimensional (2-dim) capacitor type of piezoelectric film or fiber device. C-PEG yarn was also fabricated via the dip-coating of a PDMS polymer solution, followed by winding with Ag-coated nylon fiber as an outer electrode. The current and power density of ten pieces of C-PEG yarn were correspondingly 22 nA cm-2 and 8.6 µW cm-3 at V G = 1.97 V, higher than previously reported values of 5.54 and 6 µW cm-3. The C-PEG yarn, which can generate high voltage compared to the conventional film/nanofiber mat type, is expected to be very useful as a wearable energy generator system.

Current Status of Amebic Liver Abscess in Korea Comparing with Pyogenic Liver Abscess.

Backgrounds/Aims: With the improvement of hygiene, the incidence of amebic liver abscess is decreasing in South Korea. On the other hand, there is little data on the status of amebic liver abscess compared to pyogenic liver abscess. Methods: Patients with an amebic liver abscess, in whom Entamoeba histolytica (E. histolytica) IgG was positive, were identified retrospectively in a university hospital. The clinical, laboratory, and radiological characteristics of amebic liver abscess were compared with those of pyogenic liver abscess in the same period. Results: Between March 2010 and October 2016, 413 patients with a liver abscess were identified. Among them, the serologic test for E. histolytica was performed in 209 patients. Fifteen (7.2%) were classified as an amebic liver abscess, and the remainder were diagnosed with a pyogenic liver abscess. The age, gender, white blood cell, and CRP was comparable between the two groups. Procalcitonin was lower in amebic liver abscess than the pyogenic one. On CT, peripheral rim enhancement was more frequent, but cluster signs were not observed in amebic liver abscess compared to pyogenic liver abscess. None of the patients with amebic liver abscess died. In contrast, the mortality of pyogenic liver abscess was 4.7%. Conclusions: Amebic liver abscess should still be considered as one of the causes of liver abscess in Korea. It is difficult to discriminate an amebic liver abscess from a pyogenic liver abscess only according to the clinical, laboratory, and radiologic findings. Therefore, it is necessary to perform a serologic test for E. histolytica for a precise evaluation of liver abscess in a high-risk group.

[Imaging Findings of Primary Adrenal Leiomyosarcoma: A Case Report]. / ë¶€ì‹ ì˜ 원발성 í‰í™œê·¼ìœ¡ì¢ ì˜ 영상 소견: 증례 ë³´ê³ .

Leiomyosarcoma is a malignant tumor that typically originates from either the uterus or the retroperitoneum. Furthermore, primary adrenal leiomyosarcoma is an extremely rare condition. Owing to its radiological non-specificity, differentiating leiomyosarcoma from other tumor types in the adrenal gland is difficult. We report the imaging findings of a primary adrenal leiomyosarcoma in a patient who presented with left upper quadrant abdominal pain, which increased by more than 1 cm in diameter in two years. Primary adrenal leiomyosarcoma was diagnosed considering the subsequent surgical and histopathologic findings.

Asymptomatic left ventricular hemangioma.

Cardiac hemangiomas are very rare benign neoplasms that are usually asymptomatic. Although there are often found incidentally during echocardiography, other imaging modalities such as computed tomography, magnetic resonance imaging, and coronary angiography are needed to establish a diagnosis. Surgical excision is therefore recommended to confirm the diagnosis and avoid potential complications. We report a case of asymptomatic cardiac hemangioma that was discovered incidentally during echocardiography.

Huge idiopathic pulmonary artery aneurysm.

A pulmonary artery aneurysm is an uncommon anomaly. The clinical manifestations are mostly nonspecific, and management is controversial. We report a case of a 67-year-old woman with a main pulmonary artery aneurysm who did not take surgical intervention. Subsequently, there was no increase in size for 3 years.

A Case of Advanced Gastric Cancer Concomitant with Pyogenic Liver Abscess in the Patient with Subtotal Gastrectomy.

The hematogenous spreading of an infectious pathogen via the portal vein from a mucosal injury in the gastrointestinal tract has been considered as one of the pathologic mechanisms of pyogenic liver abscess. Several studies have presented the association between colorectal cancer and pyogenic liver abscess. However, the cases of stomach cancer concomitant with pyogenic liver abscess have rarely been reported in the world. Herein, we present a case of advanced gastric cancer concomitant with pyogenic liver abscess in a patient who previously underwent subtotal gastrectomy due to peptic ulcer perforation.

Emissive ZnO-graphene quantum dots for white-light-emitting diodes.

Hybrid nanostructures combining inorganic materials and graphene are being developed for applications such as fuel cells, batteries, photovoltaics and sensors. However, the absence of a bandgap in graphene has restricted the electrical and optical characteristics of these hybrids, particularly their emissive properties. Here, we use a simple solution method to prepare emissive hybrid quantum dots consisting of a ZnO core wrapped in a shell of single-layer graphene. We then use these quantum dots to make a white-light-emitting diode with a brightness of 798 cd m(-2). The strain introduced by curvature opens an electronic bandgap of 250 meV in the graphene, and two additional blue emission peaks are observed in the luminescent spectrum of the quantum dot. Density functional theory calculations reveal that these additional peaks result from a splitting of the lowest unoccupied orbitals of the graphene into three orbitals with distinct energy levels. White emission is achieved by combining the quantum dots with other emissive materials in a multilayer light-emitting diode.

Polymer-ultrathin graphite sheet-polymer composite structured flexible nonvolatile bistable organic memory devices.

We present data, which were obtained before bending and after bending, for the electrical bistabilities, memory stabilities, and memory mechanisms of three-layer structured flexible bistable organic memory (BOM) devices, which were fabricated utilizing the ultrathin graphite sheets (UGS) sandwiched between insulating poly(methylmethacrylate) (PMMA) polymer layers. The UGS were formed by transferring UGS (about 30 layers) and using a simple spin-coating technique. Transmission electron microscopy (TEM) measurements were performed to investigate the microstructural properties of the PMMA/UGS/PMMA films. Current-voltage (I-V) measurements were carried out to investigate the electrical properties of the BOM devices containing the UGS embedded in the PMMA polymer. Current-time (I-t) and current-cycle measurements under flat and bent conditions were performed to investigate the memory stabilities of the BOM devices. The memory characteristics of the BOM maintained similar device efficiencies after bending and were stable during repeated bendings of the BOM devices. The mechanisms for these characteristics of the fabricated BOM are described on the basis of the I-V results.

Electroluminescence of a single active layer polymer-nanocrystal hybrid light-emitting diode with inversion symmetry.

A hybrid polymer-nanocrystal (NC) light-emitting diode (LED) device with a single active layer structure is simply fabricated by a spin coating. From a high-resolution transmission electron microscopy (HRTEM) study, each PVK polymer particle is observed to be capped with TPBi molecules and CdSe/ZnS NCs are mainly distributed along the circumference of PVK and TPBi surfaces, resulting in a core-shell polymer-NC hybrid of [CdSe/ZnS]/TPBi/[CdSe/ZnS]/PVK. An Al/[CdSe/ZnS]/TPBi/[CdSe/ZnS]/PVK/indium-tin oxide(ITO)/glass LED shows electroluminescence (EL) centered at around 585 nm at the forward bias of +10 V, which clearly reveals that CdSe/ZnS NCs existing at the interface between PVK and TPBi act as recombination centers for excitons. In particular, EL can be observed at both forward bias and reverse bias, and this means that this device with an isotropic distribution of NCs has an inversion symmetry.

Carrier transport in flexible organic bistable devices of ZnO nanoparticles embedded in an insulating poly(methyl methacrylate) polymer layer.

The bistable effects of ZnO nanoparticles embedded in an insulating poly(methyl methacrylate) (PMMA) polymer single layer by using flexible polyethylene terephthalate (PET) substrates were investigated. Transmission electron microscopy (TEM) images revealed that ZnO nanoparticles were formed inside the PMMA polymer layer. Current-voltage (I-V) measurement on the Al/ZnO nanoparticles embedded in an insulating PMMA polymer layer/ITO/PET structures at 300 K showed a nonvolatile electrical bistability behavior with a flat-band voltage shift due to the existence of the ZnO nanoparticles, indicative of trapping, storing, and emission of charges in the electronic states of the ZnO nanoparticles. The carrier transport mechanism of the bistable behavior for the fabricated organic bistable device (OBD) structures is described on the basis of the I-V results by analyzing the effect of space charge.

Linear ion source with closed drift and extended acceleration region.

Ion source with closed drift, which is caused by E x B field, and extended acceleration region is discussed. Though conventional circular-type closed drift ion source has advantages of high efficiency of gas ionization and low ion beam energy, there is a limitation in enlarging the beam size. Linear ion source with horse-track shape with 270 mm ceramic channel width is newly designed and tested. Inert gas (Ar) and reactive gas (O(2)) are discharged. Discharge is ignited with voltage of 90 V. Discharge current is proportional to discharge voltage and increases up to 16.3 A in argon and 15.6 A in oxygen at discharge voltage of 320 V. Extracted ion beam current is also proportional to discharge voltage and is saturated after 280 V for both gases. It is measured up to 0.78 mA/cm(2) in argon beam and 0.73 mA/cm(2) in oxygen beam at a distance of 100 mm from the ion source. Argon ion beam shows better space uniformity than oxygen across the beam extraction region.

Nonvolatile flexible organic bistable devices fabricated utilizing CdSe/ZnS nanoparticles embedded in a conducting poly N-vinylcarbazole polymer layer.

The bistable effects of CdSe/ZnS nanoparticles embedded in a conducting poly N-vinylcarbazole (PVK) polymer layer by using flexible poly-vinylidene difluoride (PVDF) and polyethylene terephthalate (PET) substrates were investigated. Transmission electron microscopy (TEM) images revealed that CdSe/ZnS nanoparticles were formed inside the PVK polymer layer. Current-voltage (I-V) measurement on the Al/[CdSe/ZnS nanoparticles+ PVK]/ITO/PVDF and Al/[CdSe/ZnS nanoparticles+ PVK ]/ITO/PET structures at 300 K showed a nonvolatile electrical bistability behavior with a flat-band voltage shift due to the existence of the CdSe/ZnS nanoparticles, indicative of trapping, storing and emission of charges in the electronic states of the CdSe nanoparticles. A bistable behavior for the fabricated organic bistable device (OBD) structures is described on the basis of the I-V results. These results indicate that OBDs fabricated by embedding inorganic CdSe/ZnS nanoparticles in a conducting polymer matrix on flexible substrates are prospects for potential applications in flexible nonvolatile flash memory devices.

Single active-layer structured dual-function devices using hybrid polymer-quantum dots.

We demonstrate hybrid polymer-quantum dot dual-function devices with a single active-layer structure consisting of CdSe/ZnS semiconductor quantum dots dispersed with poly N-vinylcarbazole (PVK) and 1,3,5-tirs-(N-phenylbenzimidazol-2-yl) benzene (TPBi) fabricated on an indium-tin-oxide (ITO)/glass substrate by using a simple spin-coating technique. The dual-function devices are composed of light-emitting diodes (LED) on the top side and nonvolatile organic bistable memory devices (OBD) on the bottom side and can show electroluminescence (EL) along with electrical bistability concurrently. Both the functionality of LEDs and OBDs can be successfully achieved by adding an electron transport layer (ETL) TPBi to the OBD to attain an LED in which the lowest unoccupied molecular orbital (LUMO) level of TPBi is positioned at the energy level between the conduction band of CdSe/ZnS and the LiF/Al electrode. Through transmission electron microscopy (TEM) study, it is revealed that CdSe/ZnS QDs distributed on the interface of the hole transport layer (HTL) and ETL significantly take part in the electroluminescence process rather than those existing at the outer surface of the ETL.