8,334 research outputs found
Neuroendocrine control of appetite and metabolism
No full textBody homeostasis is predominantly controlled by hormones secreted by endocrine organs. The central nervous system contains several important endocrine structures, including the hypothalamic-pituitary axis. Conventionally, neurohormones released by the hypothalamus and the pituitary gland (hypophysis) have received much attention owing to the unique functions of the end hormones released by their target peripheral organs (e.g., glucocorticoids released by the adrenal glands). Recent advances in mouse genetics have revealed several important metabolic functions of hypothalamic neurohormone-expressing cells, many of which are not readily explained by the action of the corresponding classical downstream hormones. Notably, the newly identified functions are better explained by the action of conventional neurotransmitters (e.g., glutamate and GABA) that constitute a neuronal circuit. In this review, we discuss the regulation of appetite and metabolism by hypothalamic neurohormone-expressing cells, with a focus on the distinct contributions of neurohormones and neurotransmitters released by these neurons. Metabolism: Dual function for neurohormone-producing cells in the brain Signaling molecules produced by the brain's hypothalamus function both as neurotransmitters (within the central nervous system) and hormones (throughout the rest of the body) to regulate appetite and metabolism. Jong-Woo Sohn and colleagues from the Korea Advanced Institute of Science and Technology in Daejeon, South Korea, summarize the well-established ways in which certain hypothalamic cells interact with parts of the pituitary gland in the brain to control the activity of hormones involved in feeding behaviors and energy balances.The same cells can also impact appetite and metabolism in non-hormonal ways. New research has shown that neurohormone-producing cells in the hypothalamus can form connections with appetite-associated neurons and communicate via neurotransmitters. A deeper understanding of this process could lead to new therapies for obesity, diabetes and other metabolic disorders.
Supplemental material for Field testing the diagnostic criteria of cluster headache in the third edition of the International Classification of Headache Disorders: A cross-sectional multicentre study
No full textSupplemental Material for Field testing the diagnostic criteria of cluster headache in the third edition of the International Classification of Headache Disorders: A cross-sectional multicentre study by Heui-Soo Moon, Soo-Jin Cho, Byung-Kun Kim, Mi Ji Lee, Pil-Wook Chung, Jong-Hee Sohn, Soo-Kyoung Kim, Yun-Ju Choi, Tae-Jin Song, Jae-Moon Kim, Jeong Wook Park, Kwang-Yeol Park, Jae-Myun Chung, Jin-Young Ahn, Byung-Su Kim, Kyungmi Oh, Kwang-Soo Lee, Chin-Sang Chung and Min Kyung Chu in Cephalalgia</p
Dutch space; interview with Arnaud de Jong, CEO
No full textDutch Space, the largest space company in the Netherlands and part of Airbus Defence and Space, appointed a new CEO last year. The Leonardo Times sat down with the CEO Arnaud de Jong for an interview. We discuss his career, developments in Dutch Space, his take on competition in the commercial space domain and his future outlook on European and International space markets.Aerospace Engineerin
Scheurvorming in jong beton: Onderzoek biedt nieuwe inzichten in de spanningsrelaxatie bij jong beton
No full textBeton is tijdens het verharden onderhevig aan thermische en autogene vervormingen. Wanneer deze worden verhinderd, resulteert dit in spanningen en het risico op scheurvorming, mede afhankelijk van relaxatie. Aan de TU Delft is onderzoek gedaan naar het effect van spanningsrelaxatie op scheurvorming in jong beton. In tegenstelling tot de verwachtingen, blijkt dat spanningsrelaxatie in de eerste twee dagen juist resulteert in een verhoogd risico op scheurvorming bij bepaalde constructies met verhinderde vervorming. Ook blijkt dat autogene zwelling daarbij een significante rol speelt, die tot op heden in de norm buiten beschouwing wordt gelaten.Materials and EnvironmentConcrete Structure
Protocol for sodium depletion and measurement of sodium appetite in mice
No full textSodium appetite is a state that motivates animals to consume normally unappetizing concentrations of sodium. Here we describe a protocol to induce sodium appetite in mice by furosemide-induced diuresis and measure sodium intake using volumetric drinking tubes. This protocol induces sodium appetite rapidly and can be used to assess the effect of various treatments on sodium appetite. This protocol does not require electronic equipment and can be implemented easily. For complete details on the use and execution of this protocol, please refer to Park et al. (2020).
AFM을 사용하는 비휘발성 메모리 장치와 상기 장치를 작동시키기 위한 방법
No full textA non-volatile memory device including a silicon oxide film formed to a desired thickness over a silicon substrate, and a plurality of nano crystals formed in the silicon oxide film by a conductive material implanted in the silicon oxide film. The invention also provides a data storing method using the non-volatile memory device. The data storing method includes the steps of disposing an atomic force microscope (AFM) tip, adapted to locally applying an electric field to a micro area, at a desired height over the semiconductor device, applying voltage of a threshold level or higher level to the AFM tip under the condition in which the height of the AFM tip is maintained, thereby effecting an electric field on a desired portion of the semiconductor device disposed beneath the AFM tip, and forcing the nano crystals formed in the silicon oxide film to capture free electrons existing in the silicon substrate by virtue of the electric field
영광 3,4호기 증기발생기의 자연순환 해석을 위한 동적 모델
No full text학위논문(석사) - 한국과학기술원 : 원자력공학과, 1995.8, [ x, 67 p. ]A dynamic model for the secondary side of Yonggwang nuclear power plant units 3 and 4 (YGN 3&4) steam generator model is developed to improve the accuracy of the present performance analysis code. The new model is based on the one-dimensional three region model to predict the local quality and void fraction distribution along the U-tube length. The local quality concept is used instead of the Wilson bubble rise correlation to simulate the steam generators in the natural circulation mode. The new model can be applicable to the plants in the power operation modes such as load maneuvering transients in which the steam generator internal flow is maintained in the natural circulation mode. To validate the new model, the code predictions are compared with the actual plant data measured for the selected load maneuvering tests performed during the YGN units 3 power ascension test period. The results from the improved model show better agreement with the plant data than those from the present code. Especially, the new model``s capability of accurately simulating the steam generator water level behavior during the fast transients such as a large load rejection event is demonstrated.한국과학기술원 : 원자력공학과
H-\infinity loop-shaping 기법을 이용한 가압경수형 원자력 발전소의 급수제어기 개발
No full text학위논문(박사) - 한국과학기술원 : 원자력및양자공학과, 2010.2, [ x, 103 p. ]In this thesis, a robust \It{H-\infin} loop-shaping controller for the steam generator (SG) feedwater control system of the KSNP (Korean Standard Nuclear Power Plant), a 1000MWe pressurized water reactor with vertical U-tube type steam generators (UTSG) is developed. The SG feedwater control system maintains the SG water level by controlling the feedwater flowrate using feedwater control valves. In order to develop the robust \It{H-\infin} controller, SG models for the control of feedwater to the KSNP UTSG are identified. As the first step of SG model identification, a precise SG mathematical thermal-hydraulic model is built using the RELAP5/MOD3 system simulation computer code. The developed RELAP5/MOD3 SG model is inadequate to be used for the design of controller due to its complexities. Thus, the SG thermal-hydraulic model needs to be simplified while maintaining required accuracy in describing the principal dynamics of the SG. For this, as the second step, a series of model experiments using the developed thermal-hydraulic model are performed in order to acquire input-output data sets representing the SG characteristics in terms of SG water level dynamics as a function of the feedwater flowrate, steam flowrate, feedwater temperature, and reactor power. As the final step, the \Bf{Simple Process Models} are applied to create a simple, continuous-time process SG model for control. The input-output data sets obtained from the model experiments using the RELAP5/MOD3 SG model are utilized in developing the algorithm to describe static gain, dominating time constants, and a possible delay of transfer function of the SG system.
Since the SG operating characteristics are strongly dependent on the operating power level, the SG operating range from 0 to 100% power is divided into 10 sub-operating points based on the plant operation experiences as well as the operating modes of the KNSP SG. A number of robust \It{H-\infin} controllers for the SG models iden...한국과학기술원 : 원자력및양자공학과
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