1,721,011 research outputs found
Jae Chul Hwang
No full text학위논문(석사)--아주대학교 일반대학원 :의학과,2007. 8배경 및 목적: 동물실험에서 Oddi 괄약근 운동성이 시간의 경과에 따라 주기적인 변화를 보이며, 이러한 주기적인 변화가 소장의 migrating motor complex (MMC)의 주기와 밀접한 연관성이 있다고 보고된 바 있다. 본 연구는 인체에서 경피적 경로를 통한 장기간의 Oddi 괄약근 내압 검사를 시행함으로써 Oddi 괄약근의 주기적 운동성을 포함하는 전체적인 운동성에 대해 살펴봄과 동시에 Oddi 괄약근의 주기적 운동성을 MMC의 각 단계로 나누어 보고, 십이지장의 MMC와의 관련성에 대해서도 알아보고자 하였다.
연구대상 및 방법: 1995년 3월부터 2006년 8월까지 31명의 담도계 수술을 시행한 적이 없고, 유두부협착이 없으며, 경피경간적 담도배액술을 시행하고 있는 담관결석 환자에서 담도경을 이용한 결석 제거 후 세 개 또는 여덟 개의 측공을 지닌 폴리에틸렌 관 이용하여 공복시 경피경간적으로 Oddi 괄약근 운동성 검사 및 십이지장의 운동성 검사를 동시에 시행하였다.
결과: 남자가 17명, 여자가 14명 이였고, 3 channel 운동측정도관을 사용한 환자가 10명, 8 channel 운동측정도관을 사용한 환자가 14명 이였으며, 3 channel 운동측정도관과 8 channel 운동측정도관을 모두 사용하여 Oddi 괄약근과 십이지장의 운동을 측정한 환자는 7명 이였다. 대상환자의 평균 연령은 55.7세(31-79)였으며, 평균 측정시간은 281.4 ± 163.8 분이였다. Oddi 괄약근의 운동은 위장관의 MMC와 유사한 주기적 운동을 보였으며, 이는 십이지장의 MMC와 관련이 있었다. Oddi 괄약근과 십이지장의 운동에서 한 주기의 기간은 각각 78.5 ± 43.5 분, 77.9 ± 40.1 분이었으며, 유의한 차이는 없었다(p=0.75). Oddi 괄약근과 십이지장의 phase I의 기간 (전체 주기에서 차지하는 비율)은 각각 11.9 ± 13.6 분 (16.7 ± 13.1 %) 과 21.9 ± 18.9 분 (29.6 ± 18.7 %) 이였으며, 유의한 차이가 있었다(p=0.004, p=0.003). Oddi 괄약근과 십이지장의 phase II의 기간 (전체 주기에서 차지하는 비율)은 각각 61.2 ± 39.3 분 (74.6 ± 15.3 %) 과 50.9 ± 34.6 분 (62.3 ± 20.3 %) 이였으며, 유의한 차이가 있었다(p=0.001, p=0.004). Phase II에서 Oddi 괄약근과 십이지장의 위상파 수축빈도는 각각 3.8 ± 0.9 회/분, 2.8 ± 0.4 회/분으로 유의한 차이가 있었다(p<0.001). Oddi 괄약근과 십이지장의 phase III의 기간 (전체 주기에서 차지하는 비율)은 각각 5.4 ± 2.1 분 (8.7 ± 5.1 %) 과 5.1 ± 1.1 분 (8.1 ± 4.3 %) 이였으며, 유의한 차이가 없었다(p=0.194, p=0.139). Phase III에서 위상파 수축빈도는 각각 10.0 ± 1.7 회/분, 10.1 ± 1.3 회/분으로 유의한 차이가 없었다(p=0.681).
결론: 사람에서 장기간 측정한 Oddi 괄약근의 운동은 위장관의 MMC와 유사한 주기적 운동을 보였으며, Oddi 괄약근의 운동은 십이지장의 MMC에 비해 phase I은 유의하게 짧았고, phase II 는 상대적으로 길어 십이지장과 다른 주기적 운동이 관찰되었다.I.서론 1
II.연구대상 및 방법 3
A.연구대상 3
B.방법 3
III.결과 6
IV.고찰 8
V.결론 12Maste
Flexible electronics based on one‐dimensional and two‐dimensional hybrid nanomaterials
No full textResearch on flexible or wearable electronics has been grown remarkably due to theadvent of nanomaterials, such as metal nanowires, graphene, or transition metaldichalcogenides. Although each nanomaterial has mechanical and electrical charac-teristics that can be applied into flexible electronics, the limitations of each nano-material are also clear. In order to overcome the limitations of these nanomaterials,research on the hybrid structures of nanomaterials has been extensively conducted.In this study, we introduce the properties of one-dimensional nanomaterials, two-dimensional nanomaterials, and their hybrid nanomaterials. And then, we provideinformation concerning various flexible electronics based on these nanomaterials.11Nsciescopu
Amorphous Oxide Semiconductor Transistors with Air Dielectrics for Transparent and Wearable Pressure Sensor Arrays
No full text© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimFlexible, transparent pressure sensors have numerous potential applications in wearable electronics, soft robotics, health monitoring. In particular, highly sensitive and reliable pressure sensors that cover wide ranges of pressures are promising because they can undergo various external stimulations. Here an unconventional approach is presented for fabricating the active-matrix array of air-dielectric, amorphous oxide semiconductor transistors for transparent, wearable pressure sensors. In the structure of these pressure-sensitive field-effect transistors (FETs), the clean interface between the air and the oxide semiconductor channel enables the FETs to have outstanding mobility and negligible electrical hysteresis with rapid and reliable responses as pressure sensors for an extensive range of pressures from 200 Pa to 5 MPa. Also, low processing temperature and high transparency of oxide semiconductors make it possible to fabricate them on plastics with flexibility and transparency. The fabrication of active-matrix pressure sensor arrays demonstrated the real-time monitoring of freely moving, ultralight, liquid droplets on the sensor. In addition, this can be integrated into the fingertips of gloves to monitor the pressure changes that occur during grasping objects. These results illustrate the potential of pressure sensors to provide robust solutions in the next-generation electronics including remote surgery, health monitoring, and robotics11Nsciescopu
Self‐Healable, Recyclable Anisotropic Conductive Films of Liquid Metal‐Gelatin Hybrids for Soft Electronics
No full text© 2021 Wiley-VCH GmbHThis paper reports an unconventional approach for the formation of self-healable and recyclable anisotropic conductive films (ACFs) using soft composites of gelatin hydrogels and liquid metals (LMs). The capsules of LMs dispersed inside the gelatin matrix can present satisfactory anisotropic conductance for electrical connections of vertically aligned, fine electrodes at room temperature by applying compressive pressures. The minimization of the capsule size as well as the softness of these LM-gelatin hybrid ACFs enables high-resolution integrations of deformable electronic systems, which can increase the integrity of freeform devices. In addition, the good fluidity of LMs and strong hydrogen bonding in gelatin enable these ACFs to be self-healable at ambient conditions and even recyclable with no significant degradations in either their original electrical or mechanical properties. The utilization of these ACFs to integrate multiple interconnections of micro-light-emitting diode arrays on a soft elastomeric substrate demonstrates a stretchable display with its reliable operations during mechanical deformations, suggesting a promising strategy for next-generation freeform and eco-friendly green electronics.11Nsciescopu
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
