• Title, Summary, Keyword: Cell grouping

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Long Term Survival after the Resection of Esophageal Cancer (식도암 절제수술 후 장기 성적)

  • 김영태;성숙환;김주현
    • Journal of Chest Surgery
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    • v.32 no.7
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    • pp.653-659
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    • 1999
  • Background: Despite the recent promising efforts to improve survival in patients with esophageal carcinoma, the long term survival results of patients with esophageal cancer have seldom been reported in Korea. To establish standard control for future studies, we re trospectively analyzed the surgical treatment results of the esophageal cancer patients managed in our department at Seoul National University Hospital. Material and Method: From January 1984 to December 1996, 734 patients were diagnosed with esophageal cancer. Among them, 253 patients underwent surgery in our department. We retrospectively analyzed the operative results and long term survival rates of these patients. Result: The majority of patients(237) had squamous cell histology and only 6 patients had adenocarcinoma. The final TNM stage grouping for these patients was based on the 1988 revised American Joint Commitee on Cancer classification. Twenty one patients were surgically classified as stage I, 109 as stage II, and 107 as stage III. C respiratory failure in 8, sepsis in 1, hepatic failure in 1, bleeding in 1 and unknown etiology in the remaining 3. The actuarial survival of 222 patients in whom the curative resection was accomplished at 1-, 2-, 3- and 5 years was 74.7${\pm}$3.1%, 46.5${\pm}$3.7%, 32.3${\pm}$3.7%, and 19.9${\pm}$3.3%, respectively. CONCLUSION: The poor long term survival rates suggest that an alternative treatment method such as intensive combined modality therapy should be developed for the management of esophageal cancer.

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A Study Analyzing Y Generation Users' Needs for Next Generation Digital Library Service (차세대디지털도서관서비스에 대한 Y세대 이용자의 요구분석 연구)

  • Noh, Younghee
    • Journal of the Korean Society for information Management
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    • v.31 no.3
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    • pp.29-63
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    • 2014
  • This study attempted to reveal the characteristics of the Y generation, to derive the services of the next generation digital library, and to compare differences between the demands of the baby boom generation and the Y generation to some extent. As a result, first, it is shown that the digital device the Y generation uses the most, was a cell phone or smartphone, followed by desktop PC, notebook PC, and digital camera. Although there were some differences, the Y generation's use ratio of digital devices was substantially similar to the baby boomers'. Second, there was a significant difference between the Y generation and baby boom generation in terms of using digital services. While the Y generation used internet portals the most, the baby boom generation used e-mail service the most. Third, we surveyed the services which the Y generation and baby boom generation require for the next generation digital libraries, by grouping as follows: the cloud service, infinite creative space (maker space), big data, augmented reality, Google Glass, context-aware technologies, semantic services, SNS service, digital textbook service, RFID and QRCode service, library space configuration, a state-of-the-art display technology, and other innovative services. While the most demanded service by the Y generation was big data service, the baby boom generation most demanded digital textbook service.

Group-based Random Access Using Variable Preamble in NB-IoT System (NB-IoT 시스템에서 가변 프리앰블을 이용한 그룹 랜덤 액세스)

  • Kim, Nam-Sun
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.13 no.5
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    • pp.370-376
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    • 2020
  • In this study, we consider a group-based random access method for group connection and delivery by grouping devices when H2H devices and large-scale M2M devices coexist in a cell in NB-IoT environment. H2H devices perform individual random access, but M2M devices are grouped according to a NPRACH transmission period, and a leader of each group performs random access. The preamble is allocated using the variable preamble allocation algorithm of the Disjoint Allocation(DA) method. The proposed preamble allocation algorithm is an algorithm that preferentially allocates preambles that maximizes throughput of H2H to H2H devices and allocates the rest to M2M devices. The access distribution of H2H and M2M devices was set as Poisson distribution and Beta distribution, respectively, and throughput, collision probability and resource utilization were analyzed. As the random access transmission slot is repeated, the proposed preamble allocation algorithm decreases the collision probability from 0.93 to 0.83 and 0.79 when the number M2M device groups are 150. In addition, it was found that the amount of increase decreased to 33.7[%], 44.9[%], and 48.6[%] of resource used.

3-Dimensional Reconstruction of Parallel fiber-Purkinje Cell Synapses Using High-Voltage Electron Microscopy (고압전자현미경을 이용한 소뇌 평행섬유-조롱박세포간 신경연접의 3차원 재구성)

  • Lee, Kea-Joo;Kweon, Hee-Seok;Kang, Ji-Seoun;Rhyu, Im-Joo
    • Applied Microscopy
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    • v.35 no.1
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    • pp.31-39
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    • 2005
  • Synapses are contact points where one neuron communicates with another. The morphological change of synapses under various physiological or pathological conditions has long been hypothesized to modify their functional properties. 3-dimensional (3-D) reconstruction of synapses with serial ultrathin sections has contributed to the understanding of ultrastructural dimensions and compositions of synapses. The 3-D reconstruction procedures, however, require a great amount of expertise as well as include prohibitively timeconsuming processes. Here, we introduce efficient 3-D reconstruction technique using high-voltage electron microscopy (HVEM). Primarily, we established an optimal section thickness and staining condition to observe synaptic structures in detail under HVEM. The result showed that synaptic profiles were preserved at the section thickness of 250 nm without the overlapping of synaptic ultrastructures. An increase in the reaction time of en bloc staining was most efficient to enhance contrast than the extension of postembedding staining or the addition of uranyl acetate during dehydration. Then, 3-D reconstruction of parallel fiber-Purkinje cell synapses in the rat cerebellum was carried out with serial HVEM images and reconstruction software. The images were aligned and the contours of synapses were outlined on each section. 3-D synapses were finally extracted from the section files by grouping all the synaptic contours. The reconstructed synapse model clearly demonstrated the configuration of pre and postsynaptic components. These results suggest that 3-D reconstruction of synapses using HVEM is much efficient and suitable for massive quantitative studies on synaptic connectivity than conventional TEM approach using numerous ultrathin sections.

Structural Features of the Glandular Trichomes in Leaves of Carnivorous Drosera anglica Huds. (식충식물 긴잎끈끈이주걱 (Drosera anglica Huds.) 분비모의 구조적 특성)

  • Baek, Kyung-Yeon;Kim, In-Sun
    • Applied Microscopy
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    • v.38 no.1
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    • pp.21-28
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    • 2008
  • Carnivorous plants vary in their unique features of morphology, ultrastructure and biochemical properties by species. Furthermore, prey-capturing mechanism as well as structural and physiological adaptations have been used for grouping various carnivorous species. In Drosera plants, glandular trichomes, which develop in the leaf epidermis, are known to play the most important role during the prey capturing process. The present study examined such trichomes, focusing on the glandular type, in leaves of Drosera anglica using scanning and transmission electron microscopy. Three types of rudimentary glandular trichomes were found to develop within the folded leaf primordia and immature leaf during early development. The first type, stalked glandular trichomes (Type I), occurred on the margin and upper epidermis of the leaf. With maturation, the longest glandular trichomes having lengthy stalks, ca. $2.2{\sim}5.1\;mm$, developed along the margin, while shorter stalked trichomes, ca. up to $200\;{\mu}m$, were found on the inner leaf blade. The shorter ones consisted of a globose head having two layers of secretory cells, parenchyma bell cells and tracheids and a multicellular stalk. The stalks gradually decreased in length in centripetal fashion. The second type, Type II, having ca. $15{\sim}30\;{\mu}m$ short stalks, also developed along the inner blade. Both types secreted mucilage from the secretory cells which had a thin cell wall and cuticle layer. The sessile six-celled glandular trichomes were the third type, Type III, and were $25{\sim}40\;{\mu}m$ in length. They were distributed most commonly throughout the upper and lower epidermis, petiole and even on the stalk surfaces of the first two types of trichomes. The third type was also found to be involved in the active secretion. In prey capturing leaves, all trichome types secreted substances through thin cuticles in the head cell wall, which exhibited relatively loose wall components.