간흡충과 N-nitrosodimethylamine을 이용한 담관암의 동물모델에서의 초음파와 자기공명영상 소견

학위논문 (석사)-- 서울대학교 대학원 : 의학과, 2014. 2. 한준구.서론: 이 연구의 목적은 간흡충과 N-nitrosodimethylamine (NMDA) 를 이용한 담관암의 동물모델에서의 초음파와 자기공명영상 소견 및 담관암과 전암성 병변의 발견 가능성을 평가하는 것이다. 방법: 24마리의 4-5주령 수컷 시리안 골든 햄스터를 아래와 같이 네 그룹으로 분리하였다. - 그룹 I (정상군): 5마리 - 그룹 II (CS): 햄스터 한 마리당 30마리의 간흡충을 투여, 5마리 - 그룹 III (NMDA): 12.5ppm 농도의 NMDA 를 포함한 물을 8주간 투여, 5마리 - 그룹 IV (CS+NMDA): 간흡충과 NMDA 를 포함한 물을 투여, 9마리 모든 햄스터에 대해서 투여 전 기저 초음파부터 투여 후 12주까지 2주 간격으로 초음파를 시행하고, 햄스터 희생 전에 조영증강 자기공명영상을 시행하였다. 햄스터 희생 후 적출된 간에 대해 병리조직학적 검사를 시행하고, 영상소견과 병리소견을 비교하였다. 결과: CS+NMDA 그룹에서 6주에 처음 담관암이 발견되었다. 총 12개의 담관암이 병리조직학적으로 확인되었으며, 그 중 10개의 담관암이 초음파 혹은 자기공명영상에서 발견되었다. 초음파와 자기공명영상 모두 담관주위 염증, 담관 확장, 낭종, 쓸개 내 슬러지 등의 소견을 잘 보여주었다. 담관주위 염증과 담관암 모두 초음파 상에서 고에코, T2 강조 자기공명영상에서 고신호의 병변으로 보였다. 결론: 초음파와 자기공명영상 모두 담관암의 발견에 유용하였다. 전암성 병변의 발견에서 자기공명영상의 유용성을 확인하였으나 T2 강조영상에서의 신호강도는 비특이적이었다. 결론적으로, 담관암 동물모델에서 전암성 병변을 영상의학적으로 발견할 수 있을 것으로 예상되며, 향후 담관암의 전암성 병변의 영상소견을 규명하여 궁극적으로 담관암의 조기발견 및 치료에 기여할 수 있을 것으로 기대된다.Purpose: To evaluate image findings and detectability of cholangiocarcinoma (CCA) and its precancerous lesions using in-vivo high-resolution ultrasonography (USG) and magnetic resonance imaging (MRI) enhanced with hepatobiliary-specific contrast media agent in the animal model of CCA using Syrian golden hamsters with C. sinensis and N-Nitrosodimethylamine (NMDA). Methods: A total of 24 male Syrian golden hamsters (Mesocricetus auratus) of 4-5 weeks old were divided randomly into 4 groups as follows: 5 hamsters of Group I (Control) as an uninfected control, 5 hamsters of Group II (CS) receiving 30 metacercariae of C. sinensis per each hamster, 5 hamsters of Group III (NDMA) receiving NMDA in drinking water, and 9 hamsters of Group IV (CS+NDMA) receiving both metacercariae and NDMA. USG was performed every other week from baseline to 12th week of infection. MRI was done from 4th week to 12th week prior to sacrifice, followed by histopathologic examination of the liver. Image findings in USG and MRI were analyzed and compared with histopathologic findings. Results: CCAs appeared in the hamsters of CS+NMDA group as early as 6th week of infection. There were a total of 12 CCAs and 10 of them were demonstrated by USG or MRI. USG and MRI also showed other findings of disease progression such as periductal increased echogenicity or signal intensity, ductal dilatation, complicated cysts, and sludges in the gallbladder. Both periductal inflammatory change and CCAs appeared as lesions of increased echogenicity on USG and increased signal intensity on T2WI of MRI. Conclusions: High-resolution USG and MRI are useful to detect the occurrence of CCAs noninvasively. Although USG was determined not to be a suitable modality in monitoring of the early precancerous lesions of CCA, MRI showed some potential to visualize precancerous lesions of CCAs, but the signal intensity on T2WI was nonspecific to distinguish precancerous lesions from periductal inflammatory change or CCAs. MRI of closer interval with more powerful sequences might be able to demonstrate the precancerous lesions of CCAs better.Abstract in Korean …………………………………………………………… i Abstract …………………………………………………………………… iii Table of Contents …………………………………………………………… v List of Tables ……………………………………………………………… vii List of Figures …………………………………………………………… viii List of Abbreviation ………………………………………………………… ix Introduction ………………………………………………………………… 1 Materials and Methods ……………………………………………………… 2 1) Experimental design …………………………………………………… 3 2) In-vivo ultrasonography ………………………………………………… 3 3) In-vivo magnetic resonance imaging …………………………………… 4 4) Histopathologic analysis ……………………………………………… 5 Results ……………………………………………………………………… 8 1) Chronological changes and representative findings of image and histopathologic findings …………………………………………………… 8 A) USG findings ………………………………………………………… 8 B) MRI findings ……………………………………………………… 21 C) Histopathologic findings …………………………………………… 23 2) Lesion-to-lesion comparison of image and histopathologic findings … 23 A) Ductal dilatation …………………………………………………… 23 B) Hepatic cysts ……………………………………………………… 28 C) Hepatic Masses …………………………………………………… 33 Discussion ………………………………………………………………… 42 Acknowledgement ………………………………………………………… 45 References ………………………………………………………………… 46Maste

Analyses bactériologiques et cellulaires des échantillons de lait chez des chèvres après sélection divergente sur la résistance aux mammites

La concentration des cellules somatiques (CCS) est un critère très utilisé pour évaluer le statut infectieux de la mamelle chez la chèvre. Grace à l’analyse en cytométrie en flux, celle-ci a été décomposée en concentrations de neutrophiles (vivants et morts), lymphocytes, macrophages dans le but d’étudier la réponse inflammatoire locale chez deux lignées de chèvres génétiquement divergentes sur le critère de la CCS. L’objectif de cette étude était de décrire l’évolution au cours de la lactation de la CCS en fonction du statut bactériologique. Les infections mammaires chez les chèvres de la lignée résistante sont moins fréquentes et avec des titres bactériens plus faibles d’après les données acquises par les méthodes conventionnelle et moléculaire. De plus, leurs réponses inflammatoire et immunitaire locales semblent plus efficaces lors d’infection

Consecutive Junction-Induced Efficient Charge Separation Mechanisms for High-Performance MoS2/Quantum Dot Phototransistors.

Phototransistors that are based on a hybrid vertical heterojunction structure of two-dimensional (2D)/quantum dots (QDs) have recently attracted attention as a promising device architecture for enhancing the quantum efficiency of photodetectors. However, to optimize the device structure to allow for more efficient charge separation and transfer to the electrodes, a better understanding of the photophysical mechanisms that take place in these architectures is required. Here, we employ a novel concept involving the modulation of the built-in potential within the QD layers for creating a new hybrid MoS2/PbS QDs phototransistor with consecutive type II junctions. The effects of the built-in potential across the depletion region near the type II junction interface in the QD layers are found to improve the photoresponse as well as decrease the response times to 950 μs, which is the faster response time (by orders of magnitude) than that recorded for previously reported 2D/QD phototransistors. Also, by implementing an electric-field modulation of the MoS2 channel, our experimental results reveal that the detectivity can be as large as 1 × 1011 jones. This work demonstrates an important pathway toward designing hybrid phototransistors and mixed-dimensional van der Waals heterostructures.The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007−2013)/ERC Grant Agreement no. 340538. This work was also supported by the National Research Foundation of Korea (NRF) (2015M2A2A6A02045252) and Samsung Global Research Outreach (Samsung GRO) program. In addition, S.M.M. would like to thank The Royal Society for financial support

Strain-Mediated Interlayer Coupling Effects on the Excitonic Behaviors in an Epitaxially Grown MoS2/WS2 van der Waals Heterobilayer.

van der Waals heterostructures composed of two different monolayer crystals have recently attracted attention as a powerful and versatile platform for studying fundamental physics, as well as having great potential in future functional devices because of the diversity in the band alignments and the unique interlayer coupling that occurs at the heterojunction interface. However, despite these attractive features, a fundamental understanding of the underlying physics accounting for the effect of interlayer coupling on the interactions between electrons, photons, and phonons in the stacked heterobilayer is still lacking. Here, we demonstrate a detailed analysis of the strain-dependent excitonic behavior of an epitaxially grown MoS2/WS2 vertical heterostructure under uniaxial tensile and compressive strain that enables the interlayer interactions to be modulated along with the electronic band structure. We find that the strain-modulated interlayer coupling directly affects the characteristic combined vibrational and excitonic properties of each monolayer in the heterobilayer. It is further revealed that the relative photoluminescence intensity ratio of WS2 to MoS2 in our heterobilayer increases monotonically with tensile strain and decreases with compressive strain. We attribute the strain-dependent emission behavior of the heterobilayer to the modulation of the band structure for each monolayer, which is dictated by the alterations in the band gap transitions. These findings present an important pathway toward designing heterostructures and flexible devices

Dataset on electro-optically tunable smart-supercapacitors based on oxygen-excess nanograin tungsten oxide thin film

The dataset presented here is related to the research article entitled ???Highly Efficient Electro-optically Tunable Smart-supercapacitors Using an Oxygen-excess Nanograin Tungsten Oxide Thin Film??? (Akbar et al., 2017) [9] where we have presented a nanograin WO3 film as a bifunctional electrode for smart supercapacitor devices. In this article we provide additional information concerning nanograin tungsten oxide thin films such as atomic force microscopy, Raman spectroscopy, and X-ray diffraction spectroscopy. Moreover, their electrochemical properties such as cyclic voltammetry, electrochemical supercapacitor properties, and electrochromic properties including coloration efficiency, optical modulation and electrochemical impedance spectroscopy are presented

Depth formulation assessment of 1D light field display using self-interference incoherent digital holography

Light field display based on a lenticular lens is currently the most commercially available three-dimensional (3D) display system that can only provide one-dimensional (1D) parallax. In this paper, we outline the criteria for evaluating the voxel formulation of a 1D light field display system and experimentally measure its expressible depth range using an incoherent holographic camera. We use self-interference incoherent digital holography with a geometric phase lens to obtain the phase profile of the light field. To analyze the characteristic of the light field display, we reconstruct the incoherent hologram and apply the autofocus algorithm to evaluate the sharpness of formulated light field

Muscle Strength Moderates the Relationship between Nutritional Health Risk and Depression in Korean Older Adults

Background: Little is known about the relationships between muscle strength and nutritional health risk with late-in-life depression. This study aimed to investigate the moderating effect of lower-extremity muscle strength on the relationship between nutritional health risk and depression in Korean older adults. Methods: Data obtained from 5949 women and 3971 men aged ≥ 65 years in the 2020 Korea Longitudinal Study on Aging were used in this study. Exposures included lower-extremity muscle strength and nutritional health risk. Lower-extremity muscle strength was measured with a modified sit-to-stand test. The nutritional health risk was assessed using a screening tool. Depression was defined as a score ≥ 8 points on the Geriatric Depression Scale (GDS). Results: Logistic regression analyses showed that depression was positively associated with nutritional health risk (p p p < 0.001) on the relationship between nutritional health risk and depression; the weaker was the muscle strength, the steeper was the slope of the GDS score for nutritional health risk. Conclusions: The current findings suggest the need for an intervention targeting both high nutritional risk and weak muscle strength as a therapeutic strategy against depression in Korean older adults

Complete mitochondrial genome of Micractinium singularis MM0003 (Chlorellaceae, Trebouxiophyceae)

The mitochondrial genome of Micractinium singularis MM0003 was completely sequenced. This mitogenome has 75,931 bp in length and consists of 62 genes including 32 protein-coding, 3 rRNA, and 27 tRNA genes. The overall GC content of the genome is 27.5%