This paper proposes a new method for measuring strain during a tensile test of the specimen with micrometre size through direct imaging. A specimen was newly designed for adoption of direct imaging ...which was the main contribution of the proposed system. The structure of the specimen has eight indicators that make it possible to adopt direct imaging and it is fabricated using the same process of microelectromechanical system (MEMS) devices to guarantee the feasibility of the tensile test. We implemented a system for non-contact in situ measurement of strain with the specimen, the image-based displacement measurement system. Extension of the gauge length in the specimen could be found robustly by computing the positions of the eight rectangular-shape indicators on the image. Also, for an easy setup procedure, the region of interest was found automatically through the analysis of the edge projection profile along the horizontal direction. To gain confidence in the reliability of the system, the tensile test for the Al-3%Ti thin film was performed, which is widely used as a material in MEMS devices. Tensile tests were performed and displacements were measured using the proposed method and also the capacitance type displacement sensor for comparison. It is demonstrated that the new strain measurement system can be effectively used in the tensile test of the specimen at microscale with easy setup and better accuracy.
COVID-19 has emerged as a pandemic leading to a global public health crisis of unprecedented morbidity. A comprehensive insight into the imaging of COVID-19 has enabled early diagnosis, ...stratification of disease severity, and identification of potential sequelae. The evolution of COVID-19 can be divided into early infectious, pulmonary, and hyperinflammatory phases. Clinical features, imaging features, and management are different among the three phases. In the early stage, peripheral ground-glass opacities are predominant CT findings, and therapy directly targeting SARS-CoV-2 is effective. In the later stage, organizing pneumonia or diffuse alveolar damage pattern are predominant CT findings and anti-inflammatory therapies are more beneficial. The risk of severe disease or hospitalization is lower in breakthrough or Omicron variant infection compared with nonimmunized or Delta variant infections. The protection rates of the fourth dose of mRNA vaccination were 34% and 67% against overall infection and hospitalizations for severe illness, respectively. After acute COVID-19 pneumonia, most residual CT abnormalities gradually decreased in extent, but they may remain as linear or multifocal reticular or cystic lesions. Advanced insights into the pathophysiologic and imaging features of COVID-19 along with vaccine benefits have improved patient care, but emerging knowledge of post-COVID-19 condition, or long COVID, also presents radiology with new challenges.
총식이조사 자료를 이용한 음식별 니트로사민 함량 분포 규명 최슬기; 이영원; 서정은 ...
Han'gug sigpum wi'saeng anjeonseong haghoeji,
10/2018, Volume:
33, Issue:
5
Journal Article
Peer reviewed
Open access
N-nitrosamines are probable or possible human carcinogens, which are produced by the reaction between secondary amines and nitrogen oxide in the acidic environment or by heating. Common risk ...assessment procedure involves the comparison between exposures expressed in the unit, mg/kg body weight/day and the Health-Based Reference dose expressed in the same unit. This procedure is suitable for the policy decision-making and is considered as inappropriate for the consumers to get information about their dietary decision-making. Therefore, the distributions of NDMA (N-nitrosodimethylamine), NDBA (N-nitrosodibutylamine), the six N-nitrosamines (NDMA, NDBA, NDEA (N-nitrosodiethylamine), NPYR (N-nitrosopyrrolidine), NPIP (N-nitrosopiperidine), and NMOR (N-nitrosomorpholine) in the menus grouped based on the presence of main ingredients and cooking methods were analyzed to generate consumer-friendly information regarding food contaminants. Recipes and intakes were taken from 2014 to 2016 KNHANES (The Korean National Health and Nutrition Examination Survey) and only the data from ages of 7 years or older were used. The contamination data were collected from the 2014~2016 Total Diet Study and all the analysis were performed using R software. Rockfish, eel, anchovy broth and pollock were mainly exposed to N-nitrosamines. In terms of cooking methods, soups and stews appeared to contain the highest amount of N-nitrosamines. Cereals, fruits, and dairy products in the ingredient categories, and rice dishes and rice combined with others in recipe categories had the lowest level exposure to N-nitrosamines. In case of N-nitrosamines, unlike other cooking related food contaminants, boiled dishes such as soups and stews and dishes mainly consisting of fishes and shellfishes had highest level of exposure, showing a large discrepancy with the previous thought of processed meat is the main source of N-nitrosamines. 니트로사민은 산성이나 열을 가했을 때 2급 아민과 질소산화물이 반응해서 생성되는 발암물질이다. 일반적으로 위해 물질에 대한 안전성평가는 그 노출량을 mg/kg body weight/day로 산출하여 독성기준치와 비교하는 방법을 사용한다. 이런 방법은 정책 근거자료로는 적합하나 소비자들에게 식생활 정보로 제공하기에 미진한 부분이 있다. 따라서 주재료 및 조리법으로 분류한 음식군에 대한 NDMA(N-nitrosodimethylamine), NDBA (N-nitrosodibutylamine) 및 6종 니트로사민(NDMA, NDBA, NDEA (N-nitrosodiethylamine), NPYR (N-nitrosopyrrolidine), NPIP (N-nitrosopiperidine), NMOR (N-nitrosomorpholine) 함량 분포를 파악하여 식습관 교육에 도움을 주고자 본 연구를 실시하였다. 2014~2016년 국민건강영양조사 24시간 회상법 자료를 사용하여 만 7세 이상을 연구 대상으로 음식별 레시피와 섭취량을 추출하였고, 2013~2015년 총식이조사 원자료를 바탕으로 음식 한끼니 제공량 내 니트로사민 함량 분포를 R프로그램으로 산출하였다. 볼락, 장어, 멸치 육수, 명태 등의 기여로 어패류 및 해조류를 주재료로 한 음식군은 섭취량과 상관없이 NDMA, NDBA 및 총 6종 니트로사민 모두에 대한 노출을 높이는 것으로 나타났다. 또한 조리법에 따른 분류에서는 국 및 탕류와 찌개 및 전골류가 가장 크게 노출에 기여하는 것으로 나타났다. 곡류, 과실류 및 유제품류 주재료 음식군, 밥류 및 밥 외의 다른 재료를 부가한 음식군들의 니트로사민 노출에 대한 기여도는 매우 낮은 것으로 나타났다. 니트로사민의 경우 조리시 생성되는 여타 화합물과는 달리 국, 탕, 찌개, 전골 등 끓임을 주로 하는 음식과 어패류를 주재료로 하는 음식에서의 기여율이 매우 높은 것으로 나타났으며, 이는 기존에 가공육류를 니트로사민의 주노출원으로 생각하던 것과는 매우 큰 차이를 보인다.
Nucleotides play important roles in numerous intracellular biochemical processes and are used in infant formulas and other dairy products. However, domestic analytical methods for assessing ...nucleotide content in products have not yet been established, and therefore, methods for determining nucleotide content are urgently required. A rapid and simple analytical method for determining the content of five types of nucleotides in dairy products was improved using solid phase extraction clean-up and high-performance liquid chromatography with diode array detector. The extraction solvent used in the AOAC method was not well dissolved and was changed to hydrophilic EDTA-Na. In addition, the results obtained using the isocratic elution method and a single wavelength were similar to those obtained using the AOAC method, and the time taken for analysis was shortened from 40 min to 25 min. The process of method validation revealed the following parameters: accuracy (84.69%-102.72%), precision (1.51%-6.82%), linearity (0.999), and limit of detection (cytidine 5'-monophosphate, 0.09 mg/L; uridine 5'-monophosphate, 0.11 mg/L; adenosine 5'-monophosphate, 0.12 mg/L; guanosine 5'-monophosphate, 0.11 mg/L; and inosine 5'-monophosphate, 0.14 mg/L). The method was also used to determine the nucleotide concentration in 25 samples (infant formulas, 1.99-29.39 mg/100 g; and cow milk, 0.28-0.83 mg/100 g). The newly improved method was appropriate for analyzing nucleotides in infant formulas and other dairy products faster when compared to conventional methods.
Background: Although the pathogenesis of non‐alcoholic fatty liver disease (NAFLD) remains poorly understood, metabolic syndrome associated with insulin resistance is the most reproducible factor in ...the development of NAFLD. Fat accumulation in hepatocytes results from an imbalance in the input, output and oxidation of fatty acid. Peroxisomes contain a battery of fatty acid oxidizing enzymes, the first of which, acyl‐CoA oxidase (AOX), initiates the β‐oxidation spiral. One of the mammalian peroxisome proliferator‐activated receptors (PPAR), PPAR‐α, regulates the transcriptional expression of the enzymes involved in fatty acid β‐oxidation. The aim of the present study was to define the role of PPAR‐α and AOX in the development of NAFLD using the Otsuka Long‐Evans Tokushima fatty (OLETF) rat model.
Methods: Liver tissue from OLETF (n = 12) and control (n = 10) rats 12, 28, and 40 weeks old were processed for histopathological and western blot analysis. The messenger RNA of PPAR‐α and AOX were quantified by real‐time RT‐PCR.
Results: At 40 weeks old, the histological analysis of the OLETF rat liver had steatosis (approximately 66%) and mild inflammation, which were comparable to those in NAFLD. Histological changes were unremarkable in 12 week and 28 week rats. In 12 week OLETF rats, the mRNA of AOX was 63% of the control. Expression of PPAR‐α mRNA was also reduced to 3% that of the control. Along with the changes of mRNA, the protein expression of PPAR‐α was also significantly reduced to 17% that of the control. In 28 week and 40 week animals, PPAR‐α protein expression gradually increased to 75% and 78% that of the control. Expression of PPAR‐α mRNA was also increased by up to 26% and 110% of the control. AOX, regulated by PPAR‐α, also increased to 149% and 120% of the control.
Conclusion: Reduced expression of PPAR‐α and AOX was observed even before definite steatosis had developed. The alteration of peroxisomal fatty acid metabolism may have an important role in the development of NAFLD.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Immature stages of the genus Plagiosterna Motschulsky are described in detail for the first time in Korea. A key for identifying larvae and pupae of Korean Plagiosterna is provided, along with ...illustrations of their habitus and larval tubercle patterns. Some remarks on their systematics are also given.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This paper proposes a new system for verification of the alignment of loading fixtures and test specimens during tensile testing of thin film with a micrometer size through direct imaging. The novel ...and reliable image recognition system to evaluate the misalignment between the load train and the specimen axes during tensile test of thin film was developed using digital image processing technology with CCD. The decision of whether alignment of the tensile specimen is acceptable or not is based on a probabilistic analysis through the edge feature extraction of digital imaging. In order to verify the performance of the proposed system and investigate the effect of the misalignment of the specimen on tensile properties, the tensile tests were performed as displacement control in air and at room temperature for metal thin film, the beryllium copper (BeCu) alloys. In the case of the metal thin films, bending stresses caused by misalignment are insignificant because the films are easily bent during tensile tests to eliminate the bending stresses. And it was observed that little effects and scatters on tensile properties occur by stress gradient caused by twisting at in-plane misalignment, and the effects and scatters on tensile properties are insignificant at out-of-plane misalignment, in the case of the BeCu thin film.
With oxidizing poly-
l-lactic acid (PLLA) surface by ozone, peroxide groups are easily generated on the surface. Those peroxides are broken down by redox-coupling reaction, and provide active species ...that initiate grafting by reaction with the collagen molecules. The surface density of generated peroxide on a PLLA surface was determined by an iodide method. The maximum concentration of peroxide was about 2.87×10
−8
mol/cm
2 when ozone oxidation was performed at 60
V for 60
min. After the surface oxidation, type I atelocollagen was grafted onto PLLA surface. All physical measurements on the collagen-grafted surface indicated that the PLLA surface was effectively grafted with type I atelocollagen. Behavior of rat calvaria osteoblasts on type I atelocollagen grafted PLLA (PLLA+COL) surface was observed. Initial attachment of osteoblasts on the surface was significantly enhanced, and it is assumed that the atelocollagen matrix supported the initial attachment and growth of cells. Collagenous protein synthesis of osteoblasts was maintained at relatively low level in the early stage of proliferation due to the primarily existing grafted type I atelocollagen, and then increased in 7 days as the osteoblast differentiated. After 7 days, collagenous protein synthesis in osteoblasts was activated. Alkaline phosphatase (ALPase) activity and mineralization by osteoblasts were promoted on PLLA+COL surface. In comparison with PLLA+COL, non-treated PLLA and tissue culture plate (TCPS) did not show any feature expressed in osteoblasts’ maturation up to 9 days in this experiment. The grafted type I atelocollagen provided a favorable matrix for cell migration in relation with collagenase expression. Ozone oxidation might be a favorable method for surface modification of PLLA membranes by collagen grafting, and cell behavior could be modulated by the grafted collagen.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Umbilical cord blood (UCB) is known to have stem/progenitor cells. We earlier showed that novel progenitors could be isolated from cryopreserved human UCB with high efficiency. The multipotent ...progenitor cells were induced to differentiate into neural-lineage cells under the appropriate condition. In this study, we confirmed these neurally induced progenitor cells (NPCs), containing higher quantities of nerve growth factor, promoted functional recovery in rats with spinal cord injury (SCI). Sprague-Dawley rats with SCI achieved a modest improvement in locomotor rating scale until 10 weeks after transplantation of the NPCs. SCI rats treated with NPCs also showed somatosensory-evoked potentials were recovered, and grafted cells especially exhibited oligodendrocytic phenotype around the necrotic cavity. These findings suggest that UCB-NPCs might be a therapeutic resource to repair damaged spinal cords.
Practice guidelines recommend endoscopic band ligation (EBL) and endoscopic variceal obturation (EVO) for bleeding from esophageal varices and fundal varices, respectively. However, the optimal ...treatment for bleeding from cardiac varices along the lesser curvature of the stomach (GOV1) remains undefined. This retrospective study compared the efficacy between EBL and EVO for bleeding from GOV1.
Patients treated by EBL or EVO via cyanoacrylate injection for bleeding from GOV1 were enrolled. Patients diagnosed with hepatocellular carcinoma or treated with endoscopic injection sclerotherapy were excluded.
The study included 91 patients treated for bleeding from GOV1. The mean age was 56.3±10.9 years (mean±SD), and 78 of them (85.7%) were men. Overall, 51 and 40 patients were treated with EBL and EVO, respectively. A trend for a higher hemostasis rate was noted in the EVO group (100%) than in the EBL group (82.6%,
=0.078). Varices rebled in 15 patients during follow-up. The rebleeding rate was significantly higher in the EBL group than in the EVO group (
=0.004). During follow-up, 13 patients died (11 in the EBL group and 2 in the EVO group); the survival rate was marginally significant between two groups (
=0.050). The rebleeding-free survival rate was significantly higher in the EVO group than in the EBL group (
=0.001).
Compared to EBL, EVO offered significantly lower rebleeding rates, significantly higher rebleeding-free survival rates, and a trend for higher hemostasis and survival rates. EVO appears to be the better therapeutic option for bleeding from GOV1.
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