• Title/Summary/Keyword: central function

Search Result 1,534, Processing Time 0.027 seconds

Renal Functional Responses to a Centrally-administered $5-HT_{1A}$ Agonist in the Anesthetized Rabbits (중추내로 투여한 $5-HT_{1A}$ 작동제에 의한 마취 가토에 있어서 신장기능의 변동)

  • Lim Young-Chai;Kim Kyung-Shim;Kook Young-Johng;Koh Jeong-Tae
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.1 no.3
    • /
    • pp.315-323
    • /
    • 1997
  • Central tryptaminergic system has been shown to play an important role in the regulation of renal function: $5-HT_1(5-hydroxytryptamine_1)$ receptors might seem to mediate the diuresis and natriuresis, whereas the $5-HT_2\;and\;5-HT_3$ receptors mediate the antidiuretic and antinatriuretic effects. This study attempted to delineate the role of central $5-HT_{1A}$ subtype in the regulation of rabbit renal function by observing the renal effects of intracerebrovent-ricularly(icv)-administered PAPP(p-aminorhenylethyl-m-trifluoromethytphenyl piperazine, LY165163), a selective agonist of $5-HT_{1A}$ receptors. PAPP in doses ranging from 40 to $350{\mu}g/kg$ icv induced significantly diuresis, natriuresis, and kaliuresis, along with increased renal perfusion and glomerular filtration. Systemic blood pressure was also increased. Free water reabsorption$(T^cH_2O)$, a measure of ADH(antidiuretic hormone) secretion, was increased also. Intravenous $350{\mu}g/kg$ of PAPP elicited antidiuresis and antinatriuresis together with decreased blood pressure, thus indicating that the effects of icv PAPP were brought about through the central mechanisms, not by direct peripheral effects of the drug on kidney. Ketanserin, a selective $5-HT_2$ antagonist, $40{\mu}g/kg$ icv, did not affect the renal effects of the icv PAPP. Methysergide, a non-selective $5-HT_1$ antagonist, also did not block the renal functional responses by the icv PAPP. NAN-190, a $5-HT_{1A}$ antagonist, also did not antagonized the renal action of the icv PAPP. However the increased free water reabsorption was abolished by both methysergide or ketanserin pretreatment. The increments of blood pressure by icv PAPP was blocked only by NAN-190 pretreatment. These observations suggest that the central $5-HT_{1A}$ receptor might be involved in the central regulation of rabbit renal function by exerting the diuretic and natriuretic influences.

  • PDF

The Role Change and Geographical Inertia of Central Places : A Case Study Chil-Bo Area, Jeon-Buk (지역 중심지의 역할 변화와 지리적 관성 -전라북도 정읍시 칠보 지역을 사례로-)

  • Cho, Sung-Wook
    • Journal of the Korean association of regional geographers
    • /
    • v.12 no.5
    • /
    • pp.571-582
    • /
    • 2006
  • This study look into a role change and geographical inertia of the central place. The place is selected and progressed as the center which is the joining of physical condition and social situation of the region. The central place is the role change according to social change but it has geographical inertia as the central place. The result is as follows. Firstly, the role of regional center is changed. This sample region is the center of a national defense and administration and traffic in Three-Country period. But the role of the national defense is disappeared with the unity of the three countries. A traffic center facility was lost because of traffic axis changed from the east-west line to the north-south line when Ko-Ryo period. A facility loss as a traffic center leads to diminish the administration function and the movement of the regional center within that area. Secondary. the new regional center function was maintained by the joining of an outside and inside peoples. It maintained the geographical inertia by Confucianism culture instead of administration function. Thirdly, it had geographical location movement within the area.

  • PDF

Renormalization of Thalamic Sub-Regional Functional Connectivity Contributes to Improvement of Cognitive Function after Liver Transplantation in Cirrhotic Patients with Overt Hepatic Encephalopathy

  • Yue Cheng;Jing-Li Li;Jia-Min Zhou;Gao-Yan Zhang;Wen Shen;Xiao-Dong Zhang
    • Korean Journal of Radiology
    • /
    • v.22 no.12
    • /
    • pp.2052-2061
    • /
    • 2021
  • Objective: The role of preoperative overt hepatic encephalopathy (OHE) in the neurophysiological mechanism of cognitive improvement after liver transplantation (LT) remains elusive. This study aimed to explore changes in sub-regional thalamic functional connectivity (FC) after LT and their relationship with neuropsychological improvement using resting-state functional MRI (rs-fMRI) data in cirrhotic patients with and without a history of OHE. Materials and Methods: A total of 51 cirrhotic patients, divided into the OHE group (n = 21) and no-OHE group (n = 30), and 30 healthy controls were enrolled in this prospective study. Each patient underwent rs-fMRI before and 1 month after LT. Using 16 bilateral thalamic subregions as seeds, we conducted a seed-to-voxel FC analysis to compare the thalamic FC alterations before and after LT between the OHE and no-OHE groups, as well as differences in FC between the two groups of cirrhotic patients and the control group. Correction for multiple comparisons was conducted using the false discovery rate (p < 0.05). Results: We found abnormally increased FC between the thalamic sub-region and prefrontal cortex, as well as an abnormally decreased FC between the bilateral thalamus in both OHE and no-OHE cirrhotic patients before LT, which returned to normal levels after LT. Compared with the no-OHE group, the OHE group exhibited more extensive abnormalities prior to LT, and the increased FC between the right thalamic subregions and right inferior parietal lobe was markedly reduced to normal levels after LT. Conclusion: The renormalization of FC in the cortico-thalamic loop might be a neuro-substrate for the recovery of cognitive function after LT in cirrhotic patients. In addition, hyperconnectivity between thalamic subregions and the inferior parietal lobe might be an important feature of OHE. Changes in FC in the thalamus might be used as potential biomarkers for recovery of cognitive function after LT in cirrhotic patients.

General Formulas for Explicit Evaluations of Ramanujan's Cubic Continued Fraction

  • Naika, Megadahalli Sidda Naika Mahadeva;Maheshkumar, Mugur Chinna Swamy;Bairy, Kurady Sushan
    • Kyungpook Mathematical Journal
    • /
    • v.49 no.3
    • /
    • pp.435-450
    • /
    • 2009
  • On page 366 of his lost notebook [15], Ramanujan recorded a cubic continued fraction and several theorems analogous to Rogers-Ramanujan's continued fractions. In this paper, we derive several general formulas for explicit evaluations of Ramanujan's cubic continued fraction, several reciprocity theorems, two formulas connecting V (q) and V ($q^3$) and also establish some explicit evaluations using the values of remarkable product of theta-function.

The Role of a Neurovascular Signaling Pathway Involving Hypoxia-Inducible Factor and Notch in the Function of the Central Nervous System

  • Kim, Seunghee;Lee, Minjae;Choi, Yoon Kyung
    • Biomolecules & Therapeutics
    • /
    • v.28 no.1
    • /
    • pp.45-57
    • /
    • 2020
  • In the neurovascular unit, the neuronal and vascular systems communicate with each other. O2 and nutrients, reaching endothelial cells (ECs) through the blood stream, spread into neighboring cells, such as neural stem cells, and neurons. The proper function of neural circuits in adults requires sufficient O2 and glucose for their metabolic demands through angiogenesis. In a central nervous system (CNS) injury, such as glioma, Parkinson's disease, and Alzheimer's disease, damaged ECs can contribute to tissue hypoxia and to the consequent disruption of neuronal functions and accelerated neurodegeneration. This review discusses the current evidence regarding the contribution of oxygen deprivation to CNS injury, with an emphasis on hypoxia-inducible factor (HIF)-mediated pathways and Notch signaling. Additionally, it focuses on adult neurological functions and angiogenesis, as well as pathological conditions in the CNS. Furthermore, the functional interplay between HIFs and Notch is demonstrated in pathophysiological conditions.

ORTHOGONAL MULTI-WAVELETS FROM MATRIX FACTORIZATION

  • Xiao, Hongying
    • Journal of the Korean Mathematical Society
    • /
    • v.46 no.2
    • /
    • pp.281-294
    • /
    • 2009
  • Accuracy of the scaling function is very crucial in wavelet theory, or correspondingly, in the study of wavelet filter banks. We are mainly interested in vector-valued filter banks having matrix factorization and indicate how to choose block central symmetric matrices to construct multi-wavelets with suitable accuracy.

Development of the central control system using IP PBX convergence with broadcasting function (방송기능이 있는 IP PBX 융합 중앙 관제 시스템 개발)

  • Kim, Sam-Taek
    • Journal of the Korea Convergence Society
    • /
    • v.12 no.7
    • /
    • pp.1-6
    • /
    • 2021
  • Currently, virus infection such as Corona 19 has become commonplace, and interest in unmanned systems is increasing in the field for non-face-to-face ICT services. In this paper, the function and performance of remotely successfully controlling a store through video and audio using an IP PBX with a broadcasting function was verified through a test. And the fully unmanned system is not gaining credibility due to various technical problems, however the central control system is a very efficient and reliable system because the controller can directly control the customer while monitoring the access and the inside of the store through the video and audio. In the future, we plan to study a completely unmanned remote control system using A.I technology.

Recurrence Formula for the Central Moments of Number of Successes with n Poisson Trials

  • Moon, Myung-Sang
    • Journal of the Korean Data and Information Science Society
    • /
    • v.14 no.2
    • /
    • pp.385-391
    • /
    • 2003
  • A sequence of n Bernoulli trials which violates the constant success probability assumption is termed as "Poisson trials". In this paper, the recurrence formula for the r-th central moment of number of successes with n Poisson trials is derived. Romanovsky's method, based on the differentiation of characteristic function, is used in the derivation of recurrence formula for the central moments of conventional binomial distribution. Romanovsky's method is applied to that of Poisson trials in this paper. Some central moment calculation results are given to compare the central moments of Poisson trials with those of conventional binomial distribution.

  • PDF