24 research outputs found

    Nanovesicles derived from iron oxide nanoparticles-incorporated mesenchymal stem cells for cardiac repair

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    Because of poor engraftment and safety concerns regarding mesenchymal stem cell (MSC) therapy, MSC-derived exosomes have emerged as an alternative cell-free therapy for myocardial infarction (MI). However, the diffusion of exosomes out of the infarcted heart following injection and the low productivity limit the potential of clinical applications. Here, we developed exosome-mimetic extracellular nanovesicles (NVs) derived from iron oxide nanoparticles (IONPs)-incorporated MSCs (IONP-MSCs). The retention of injected IONP-MSC-derived NVs (IONP-NVs) within the infarcted heart was markedly augmented by magnetic guidance. Furthermore, IONPs significantly increased the levels of therapeutic molecules in IONP-MSCs and IONP-NVs, which can reduce the concern of low exosome productivity. The injection of IONP-NVs into the infarcted heart and magnetic guidance induced an early shift from the inflammation phase to the reparative phase, reduced apoptosis and fibrosis, and enhanced angiogenesis and cardiac function recovery. This approach can enhance the therapeutic potency of an MSC-derived NV therapy.

    Diet of children under the government-funded meal support program in Korea

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    The purpose of this study was to investigate the diet of children under the government-funded meal support program. The 143 children (67 boys and 76 girls) participated in this study among 4th-6th elementary school students receiving free lunches during the summer vacation of 2007 and living in Gwanak-gu, Seoul, Korea. The subjects consisted of four groups supported by Meal Box Delivery (n = 26), Institutional Foodservice (n = 53), Restaurant Foodservice (n = 27), or Food Delivery (n = 37). A three-day 24-hour dietary recall and a self-administered survey were conducted. In addition, the children's heights and weights were measured. The average energy intake of the children was 1,400 kcal per day, much lower than the Estimated Energy Requirements of the pertinent age groups. The results also showed inadequate intake of all examined nutrients; of particular concern was the extremely low intake of calcium. On average, the children consumed eight dishes and 25 food items per day. The children supported by Meal Box Delivery consumed more various dishes and food items than the other groups. The percentage of children preferring their current meal support method was the highest in those supported by Meal Box Delivery and the lowest in those supported by Food Delivery. We requested 15 children among the 143 children participating in the survey to draw the scene of their lunch time. The drawings of the children supported by Institutional Foodservice showed more positive scenes than the other groups, especially in terms of human aspects. In conclusion, the overall diet of children under the government-funded meal support program was nutritionally inadequate, although the magnitude of the problems tended to differ by the meal support method. The results could be utilized as basic data for policy and programs regarding the government-funded meal support program for children from low-income families

    Simulation on fiber-to-waveguide coupling efficiency of Si3N4 grating coupler for quantum nano-photonics

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    Recently, Si3N4 has been investigated as a quantum nano-photonics platform due to its low propagation loss and high refractive index. Light can be efficiently coupled from fiber to Si3N4 waveguide and vice versa using a grating coupler. We perform computational simulations on grating couplers to find the optimum geometric conditions of fiber-to-waveguide coupling efficiency in the telecom wavelength range. According to our simulation, the fiber-to-waveguide coupling efficiency can be more than 60%. Our results would be useful for future quantum optics experiments.2

    PROX1, a Key Mediator of the Anti-Proliferative Effect of Rapamycin on Hepatocellular Carcinoma Cells

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    The MTOR signal is known to be activated in various cancer cells including hepatocellular carcinoma (HCC) cells. Rapamycin, a specific inhibitor of MTOR, has been widely used as an immunosuppressant in organ transplant patients, and its clinical application has been recently expanded to cancer therapy. In this study, the anti-proliferative effect of rapamycin was investigated in four different HCC cell lines. Rapamycin effectively inhibited the proliferation of Huh7 or Hep3B, but not that of HepG2 or SNU3160 cells. Interestingly, rapamycin increased Prospero-related homeobox 1 (PROX1) expression at the protein level, but did not affect its transcript in Huh7 as well as Hep3B cells. Moreover, immunoprecipitation assays showed that PROX1 ubiquitination was downregulated by rapamycin. Furthermore, PROX1 over-expression or siRNA knock-down in Huh7 and Hep3B cells reduced or increased proliferation, respectively. The effect of PROX1 over-expression on the sensitivity to rapamycin was not synergistic, but the effect of MTOR inhibition on cell proliferation was diminished by PROX1 siRNA. Finally, Huh7 cells were inoculated into the flanks of nude mice and rapamycin was injected daily for 14 days. The xenograft volume was decreased and PROX1 expression was increased by rapamycin. These results indicate that PROX1 plays a key role in the anti-proliferative effect of rapamycin and suggest that the increased PROX1 by MTOR inhibition can be used as a useful marker for predicting whether HCC cells can be affected by rapamycin

    Study on the Ion Mobility Spectrometry Data Classification and Application of Port Container Narcotics Using Machine Learning Algorithm

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    Narcotics should be strictly controlled as they can cause great disruption to society. Narcotics mostly flow into ports from major narcotic makers via transit points and through cargo containers. To prevent narcotic entry through smuggling, airports use animals or detect narcotics through X-rays. However, the use of animals in ports is not practical, and the method using X-rays sometimes does not detect substance narcotics with low atomic numbers. In this paper, we aimed to detect and classify narcotics using ion mobility spectrometry (IMS) data generated by inhaling air inside the container. To classify narcotic IMS data consisting of time-series data, the performance was improved using a time-series classification machine learning algorithm instead of the threshold method previously used. To this end, K-nearest neighbor, time-series forest, and random convolutional kernel algorithms were applied to the proposed algorithm considering the features of narcotic IMS data. The results demonstrate that the proposed algorithm outperforms the existing algorithm, and it reduces the classification performance processing time up to 5 s with more than 0.9 accuracy level

    Detecting Deformation on Pantograph Contact Strip of Railway Vehicle on Image Processing and Deep Learning

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    An electric railway vehicle is supplied with electricity by an OCL (Overhead Contact Line) through the contact strip of its pantograph. This transmitted electricity is then used to power the electrical equipment of the railway vehicle. This contact strip wears out due to contact with the OCL. In particular, deformations due to chipping and material loss occur because of friction with the fittings on the OCL. These deformations on the contact strip affect its power transmission quality because of contact loss with the OCL. However, it is difficult to monitor the contact strip during operation and judge its condition in order to implement accident prevention measures. Thus, in this study, we developed a contact strip monitoring method based on image processing for inspection. The proposed method measures the deformation in the contact strip based on an algorithm that determines the wear on the deformed contact strip using deep learning and image processing. The image of the contact strip is acquired by installing a camera and laser to capture the pantograph as it passes the setup. The proposed algorithm is able to determine the wear size by extracting the edges of the laser line using deep learning and estimating the fitted line of the deformations based on the least squares method

    Compiler-assisted demand paging for embedded systems with flash memory

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    In this paper, we propose a novel, application specific de-mand paging mechanism for low-end embedded systems with flash memory as secondary storage. These systems are not equipped with virtual memory. A small memory space called an execution buffer is allocated to page an application. An application-specific page manager man-ages the buffer. The manager is generated by a compiler post-pass and combined with the application image. Our compiler post-pass analyzes the ELF executable image of an application and transforms function call/return instruc-tions into calls to the page manager. As a result, each function of the code can be loaded into memory on de-mand at run time. To minimize the overhead of demand paging, code clustering algorithms are also presented. We evaluate our techniques with five embedded applications. We show that our approach can reduce the code mem-ory size by 33 % on average with reasonable performance degradation (8-20%) and energy consumption (10 % more on average) for low-end embedded systems

    Evaluation of monoclonal antibody–based immunohistochemistry for the detection of European and North American \u3ci\u3ePorcine reproductive and respiratory syndrome virus\u3c/i\u3e and a comparison with in situ hybridization and reverse transcription polymerase chain reaction

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    The objective of the present study was to compare the ability of 2 monoclonal antibodies (mAbs; SDOW17 and SR30) to detect types 1 and 2 Porcine reproductive and respiratory syndrome virus (PRRSV) in formalin-fixed, paraffin-embedded (FFPE) lung tissues by immunohistochemistry (IHC) and to compare the immunohistochemical results with in situ hybridization (ISH) and reverse transcription nested polymerase chain reaction (RT-nPCR) detection techniques. Lungs from 30 experimentally infected pigs (15 pigs with each genotype of PRRSV) and 20 naturally infected pigs (10 pigs with each genotype of PRRSV) with types 1 and 2 PRRSV, respectively, were used for the IHC, ISH, and RTnPCR analyses. The SR30 mAb-based IHC detected significantly more type 1 PRRSV-positive cells in the accessory and caudal lobes from the experimentally infected pigs at 7 (P = 0.025) and 14 (P = 0.018) days postinoculation, respectively, compared to the SDOW17 mAb-based IHC. The results demonstrated that SR30 mAb-based IHC is useful for detecting both types 1 and 2 PRRSV antigen in FFPE lung tissues

    Poloxamer-Based Thermoreversible Gel for Topical Delivery of Emodin: Influence of P407 and P188 on Solubility of Emodin and Its Application in Cellular Activity Screening

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    Emodin is a component in a Chinese herb, Rheum officinale Baill, traditionally used for diabetes and anticancer. Its poor solubility is one of the major challenges to pharmaceutical scientists. We previously reported on thermoreversible gel formulations based on poloxamer for the topical delivery of emodin. The present study was to understand the effect of poloxamer type on emodin solubility and its application in cellular activity screening. Various gel formulations composed of poloxamer 407 (P407), poloxamer 188 (P188) and PEG400 were prepared and evaluated. Major evaluation parameters were the gelation temperature (Tgel) and solubility of emodin. The emodin solubility increased with increasing poloxamer concentration and the Tgel was modulated by the proper combination of P407. In particular, this study showed that the amount of P407 in thermoreversible poloxamer gel (PG) was the dominant factor in enhancing solubility and P188 was effective at fixing gelation temperature in the desired range. A thermoreversible emodin PG was selected as the proper composition with the liquid state at room temperature and gel state at body temperature. The gel showed the solubility enhancement of emodin at least 100-fold compared to 10% ethanol or water. The thermoreversible formulation was applied for in vitro cellular activity screening in the human dermal fibroblast cell line and DLD-1 colon cancer cell line after dilution with cell culture media. The thermoreversible gel formulation remained as a clear solution in the microplate, which allowed reliable cellular activity screening. In contrast, emodin solution in ethanol or DMSO showed precipitation at the corresponding emodin concentration, complicating data interpretation. In conclusion, the gel formulation is proposed as a useful prototype topical formulation for testing emodin in vivo as well as in vitro
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