643 research outputs found
Synchronous double primary malignant tumor of the gallbladder and liver: a case report
We report a case of synchronous double primary tumor of gallbladder and liver. A 63-year-old male was admitted to the hospital complaining of abdominal discomfort. Enhanced computed tomography of the abdomen showed acute cholecystitis with tiny gallbladder stones and a 2.2 cm size enhanced nodule in the left lobe of the liver. Under the impression of acute cholecystitis with gall bladder stones and hepatocellular carcinoma of the left Liver, the patient underwent a laparotomy. At laparotomy, a mass was palpated on the surface of the neck portion of the gall bladder. Intraoperative frozen diagnosis revealed adenocarcinoma of the gall bladder. The patient was diagnosed as having gall bladder cancer and hepatocellular carcinoma, so extended cholecystectomy with dissection of regional lymph nodes and left hemihepatectomy were performed. Histological examination revealed moderated differentiated adenocarcinoma of gallbladder and hepatocellular carcinoma of liver. To our knowledge, the simultaneous occurrence of primary malignant tumor of the gallbladder and liver has never been published before. The patient is doing well with no evidence of recurrence 17 months after surgery
Isoindigo as a Building Block for Semiconducting Conjugated Polymers for High Performance Organic Photovoltaics
One of the most important issues for enhancing the power conversion efficiency (PCE) of polymer solar cells (PSCs) is the development of conjugated polymers which exhibit broad light absorption with strong absorptivity, high charge carrier mobility, suitable energy level matching with the electron acceptor (fullerene derivatives), and appropriate molecular orientation to form an optimum pathway of charge carriers to the corresponding electrodes. In past few years, remarkable progress in the PCE surpassing 8% have been achieved with the configuration of bulk-heterojunction network structure consisting of high performance conjugated polymer as an electron donor and fullerene derivative as an acceptor.
Isoindigo is a dye molecule with two lactam rings pertaining strong electron-withdrawing characteristic and planar ∏-conjugated structure. Particularly, the planar molecular structure is expected to afford high charge carrier mobility. Moreover, isoindigo-based organic compounds show broad optical absorption, high extinction coefficient, and deep HOMO energy level. Therefore, isoindigo is a promising building block for constructing low bandgap conjugated polymers to achieve high performance PSCs.OAIID:oai:osos.snu.ac.kr:snu2014-01/104/0000001236/4SEQ:4PERF_CD:SNU2014-01EVAL_ITEM_CD:104USER_ID:0000001236ADJUST_YN:NEMP_ID:A004558DEPT_CD:445CITE_RATE:0FILENAME:초록및프로그램_5월프랑스.pdfDEPT_NM:재료공학부CONFIRM:
An Active and Soft Hydrogel Actuator to Stimulate Live Cell Clusters by Self-folding
The hydrogels are widely used in various applications, and their successful uses depend on controlling the mechanical properties. In this study, we present an advanced strategy to develop hydrogel actuator designed to stimulate live cell clusters by self-folding. The hydrogel actuator consisting of two layers with different expansion ratios were fabricated to have various curvatures in self-folding. The expansion ratio of the hydrogel tuned with the molecular weight and concentration of gel-forming polymers, and temperature-sensitive molecules in a controlled manner. As a result, the hydrogel actuator could stimulate live cell clusters by compression and tension repeatedly, in response to temperature. The cell clusters were compressed in the 0.7-fold decreases of the radius of curvature with 1.0 mm in room temperature, as compared to that of 1.4 mm in 37 degrees C. Interestingly, the vascular endothelial growth factor (VEGF) and insulin-like growth factor-binding protein-2 (IGFBP-2) in MCF-7 tumor cells exposed by mechanical stimulation was expressed more than in those without stimulation. Overall, this new strategy to prepare the active and soft hydrogel actuator would be actively used in tissue engineering, drug delivery, and micro-scale actuators
High Performance n-Channel Organic Field-Effect Transistor of Conjugated Polymers with Fluorine-Substituted Phenylene Unit
OAIID:oai:osos.snu.ac.kr:snu2013-01/104/0000001236/9SEQ:9PERF_CD:SNU2013-01EVAL_ITEM_CD:104USER_ID:0000001236ADJUST_YN:NEMP_ID:A004558DEPT_CD:445CITE_RATE:0FILENAME:20130328_한국영국교류_(120x90)_정의혁.pdfDEPT_NM:재료공학부EMAIL:[email protected]:
Down-regulation of ARC contributes to vulnerability of hippocampal neurons to ischemia/hypoxia
AbstractARC is a caspase recruitment domain-containing molecule that plays an important role in the regulation of apoptosis. We examined ARC expression during neuronal cell death following ischemic injury in vivo and in vitro. After exposure to transient global ischemic conditions, the expression of ARC was substantially reduced in the CA1 region of hippocampus in a time-dependent manner with concomitant increase of TUNEL-positive cells. Quantitative analysis using Western blotting exhibited that most of ARC protein disappeared in the cultured hippocampal neurons exposed to hypoxia for 12 h and showing 60% cell viability. Forced expression of ARC in the primary cultures of hippocampal neurons or B103 neuronal cells significantly reduced hypoxia-induced cell death. Further, the C-terminal P/E rich region of ARC was effective to attenuate hypoxic insults. These results suggest that down-regulation of ARC expression in hippocampal neurons may contribute to neuronal death induced by ischemia/hypoxia
Co-occurrence matrix analysis-based semi-supervised training for object detection
One of the most important factors in training object recognition networks
using convolutional neural networks (CNNs) is the provision of annotated data
accompanying human judgment. Particularly, in object detection or semantic
segmentation, the annotation process requires considerable human effort. In
this paper, we propose a semi-supervised learning (SSL)-based training
methodology for object detection, which makes use of automatic labeling of
un-annotated data by applying a network previously trained from an annotated
dataset. Because an inferred label by the trained network is dependent on the
learned parameters, it is often meaningless for re-training the network. To
transfer a valuable inferred label to the unlabeled data, we propose a
re-alignment method based on co-occurrence matrix analysis that takes into
account one-hot-vector encoding of the estimated label and the correlation
between the objects in the image. We used an MS-COCO detection dataset to
verify the performance of the proposed SSL method and deformable neural
networks (D-ConvNets) as an object detector for basic training. The performance
of the existing state-of-the-art detectors (DConvNets, YOLO v2, and single shot
multi-box detector (SSD)) can be improved by the proposed SSL method without
using the additional model parameter or modifying the network architecture.Comment: Submitted to International Conference on Image Processing (ICIP) 201
Long-term Results of Primary Total Knee Arthroplasty with and without Patellar Resurfacing
Among patients that underwent total knee arthroplasty from June, 1990 to January, 1999, 61 cases (44 patients) that could be followed for more than 10 years were included in this study. The patients were divided into a patellar retention group and a patellar resurfacing group, and were compared with regard to their clinical and radiological outcomes. In patients undergoing primary TKA, a selective patellar resurfacing protocol was used. The indications for patellar retention were a small patella, nearly normal articular cartilage, minimal preoperative patellofemoral pain, poor patellar bone quality, and young patient age. When patellar retention was performed, osteophytes of the patella were removed and marginal electrocauterization was carried out. There were 25 cases (20 patients) in the patellar retention group and 36 cases (29 patients) in the patellar resurfacing group. The mean follow-up period was 140.7 months in the patellar retention group and 149.0 months in the patellar resurfacing group. The selective patellar resurfacing with total knee arthroplasty had a favorable outcome;there were a significant difference noted between the 2 groups in the functional scores, which showed better outcomes in the patellar resurfacing group than in the patellar retention group
Refracture after locking compression plate removal in displaced midshaft clavicle fractures after bony union: a retrospective study
Background A midshaft clavicle fracture is a common fracture that typically responds well to open reduction and internal fixation (ORIF). However, refracture can occur after implant removal (IR). This study aimed to analyze the rate of refracture and related factors after removal of the locking compression plate (LCP) for displaced midshaft clavicle fractures. Methods We retrospectively reviewed the medical records of 201 patients who had undergone ORIF with LCP for midshaft clavicle fractures after IR after bony union from January 2011 to May 2018 at our institute. We evaluated basic demographic characteristics and radiographic parameters. All patients were treated with an LCP for primary fracture. The patients were divided into two groups: a refracture group that experienced a second fracture within 1 year after IR and a no-fracture group. Results There were four cases (1.99%) of refracture; three were treated conservatively, while one was treated surgically. All patients achieved bony union. The average interval between refracture and IR was 64 days (range, 6–210 days). There was a significant difference in classification of fractures (AO Foundation/Orthopaedic Trauma Association [AO/OTA] classification) between the two groups. However, other patient demographics and radiographic measurements between refracture and IR, such as bone diameter, showed no significant difference between the two groups. Conclusions This study showed that one in 50 patients suffered from refracture after removal of the LCP. Thus, if patients desire IR, the surgeon should explain that there is a relatively higher possibility of refracture for cases with simple or segmental fractures than for other types of fracture
An in vitro evaluation of graphene oxide reduced by Ganoderma spp. in human breast cancer cells (MDA-MB-231)
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