• Journal of Veterinary Science
• /
• v.24 no.2
• /
• pp.27.1-27.15
• /
• 2023

Background: The relationships between the postpartum subacute ruminal acidosis (SARA) occurrence and predicted bacterial functions during the periparturient period are still not clear in Holstein cows. Objectives: The present study was performed to investigate the alterations of rumen fermentation, bacterial community structure, and predicted bacterial functional pathways in Holstein cows. Methods: Holstein cows were divided into the SARA (n = 6) or non-SARA (n = 4) groups, depending on whether they developed SARA during the first 2 weeks after parturition. Reticulo-ruminal pH was measured continuously during the study period. Reticulo-ruminal fluid samples were collected 3 weeks prepartum, and 2 and 6 weeks postpartum, and blood samples were collected 3 weeks before, 0, 2, 4 and 6 weeks postpartum. Results: The postpartum decline in 7-day mean reticulo-ruminal pH was more severe and longer-lasting in the SARA group compared with the non-SARA group. Changes in predicted functional pathways were identified in the SARA group. A significant upregulation of pathway "PWY-6383" associated with Mycobacteriaceae species was identified at 3 weeks after parturition in the SARA group. Significantly identified pathways involved in denitrification (DENITRIFICATION-PWY and PWY-7084), detoxification of reactive oxygen and nitrogen species (PWY1G-0), and starch degradation (PWY-622) in the SARA group were downregulated. Conclusions: The postpartum SARA occurrence is likely related to the predicted functions of rumen bacterial community rather than the alterations of rumen fermentation or fluid bacterial community structure. Therefore, our result suggests the underlying mechanisms, namely functional adaptation of bacterial community, causing postpartum SARA in Holstein cows during the periparturient period.

• Journal of Korean geriatric psychiatry
• /
• v.16 no.1
• /
• pp.17-23
• /
• 2012

The diagnosis of Alzheimer's disease (AD) is still obscure even to specialists. To improve the diagnostic accuracy, to find at-risk people as early as possible, to predict the efficacy or adverse reactions of pharmacotherapy on an individual basis, to attain more reliable results of clinical trials by recruiting better defined participants, to prove the disease-modifying ability of new candidate drugs, to establish prognosis-based therapeutic plans, and to do more, is now increasing the need for biomarkers for AD. Among AD-related biochemical markers, cerebrospinal beta-amyloid and tau have been paid the most attention since they are materials directly interfacing the brain interstitium and can be obtained through the lumbar puncture. Level of beta-amyloid is reduced whereas tau is increased in cerebrospinal fluid of AD patients relative to cognitively normal elderly people. Remarkably, such information has been found to help predict AD conversion of mild cognitive impairment. Despite inconsistent findings from previous studies, plasma beta-amyloid is thought to be increased before the disease onset, but show decreasing change as the disease progress. Regarding other peripheral biochemical markers, omics tools are being widely used not only to find useful biomarkers but also to generate novel hypotheses for AD pathogenesis and to lead new personalized future medicine.

• Tuberculosis and Respiratory Diseases
• /
• v.47 no.1
• /
• pp.50-56
• /
• 1999

Background : Pleural effusion is a common clinical problem and many clinical and laboratory evaluations, such as tumor marks, have been studied to discriminate malignant pleural fluid from benign pleural fluid. However their usefulness in the diagnosis of pleural effusion is still not established fully. We studied the diagnostic value of cyfra 21-1 in diagnosis of malignant pleural effusion. Methods: Pleural fluid was obtained from 45 patients with malignant diseases(32 lung cancer patients, 13 metastatic malignant diseases) and 47 patients with benign diseases. The level of cyfra 21-1 in the pleural fluid and serum were determined using a CYFRA 21-1 enzyme immunoassay kit(Cis-Bio International Co.). The t-test was used for comparison between two diseases groups and receiver operating characteristic(ROC) curves were constructed by calculating the sensitivities and specificities of the cyfra 21-1 at several points to determine the diagnostic accuracy of the cyfra 21-1. Results: In patients with primary lung cancer, the level of cyfra 21-1 in the pleural fluid was significantly higher than those of patients with benign diseases and had positive correlations between the level of cyfra 21-1 in the pleural fluid and serum levels. In the ROC curve analysis of the pleural fluid, the curve for primary lung cancer group was located closer to the left upper comer and the cut off value, sensitivity and specificity of the cyfra 21-1 of the primary lung cancer group was determined as 22.25ng/ml, 81.8% and 78.7% respectively. Conclusions: Our data indicates that the measurement of cyfra 21-1 level in pleural effusion has useful diagnostic value to discriminate malignant pleural effusion in primary lung cancer from benign pleural effusion.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.12
• /
• pp.844-861
• /
• 2008

The papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during the year of 2007 have been reviewed. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environments. The conclusions are as follows. (1) The research trends of fluid engineering have been surveyed as groups of general fluid flow, fluid machinery and piping, etc. New research topics include micro nano fluid, micropump and fuel cell. Traditional CFD was still popular and widely used in research and development. Studies about fans and pumps were performed in the field of fluid machinery. Characteristics of flow and fin shape optimization are studied in the field of piping system. (2) The research works on heat transfer have been reviewed in the field of heat transfer characteristics, heat exchangers, and desiccant cooling systems. The research on heat transfer characteristics includes thermal transport in pulse tubes, high temperature superconductors, ground heat exchangers, fuel cell stacks and ice slurry systems. For the heat 'exchangers, the research on pin-tube heat exchanger, plate heat exchanger, condensers and gas coolers has been cordially implemented. The research works on heat transfer augmenting tubes have been also reported. For the desiccant cooling systems, the studies on the design and operating conditions for desiccant rotors as well as performance index are noticeable. (3) In the field of refrigeration, many papers were presented on the air conditioning system using CO2 as a refrigerant. The issues on the two-stage compression, the oil selection, and the appropriate oil charge were treated. The subjects of alternative refrigerants were also studied steadily. Hydrocarbons, DME and their mixtures were considered and various heat transfer correlations were proposed. (4) Research papers have been reviewed in the field of building facilities by grouping into the researches on heat and cold sources, air conditioning and air cleaning, ventilation and fire research including tunnel ventilation, flow control of piping system, and sound research with drain system. Main focuses have been addressed to the promotion of efficient or effective use of energy, which helps to save energy and results in reduced environmental pollution and operating cost. (5) Studies were mostly focused on analyzing the indoor environment in various spaces like cars, old tombs, machine rooms, and etc. in an architectural environmental field. Moreover, subjects of various fields such as the evaluation of noise, thermal environment, indoor air quality and development of energy analysis program were researched by various methods of survey, simulation, and field experiment.

• Journal of the Korean Society of Radiology
• /
• v.83 no.3
• /
• pp.538-558
• /
• 2022

The perivascular space (PVS) of the brain, also known as Virchow-Robin space, consists of cerebrospinal fluid and connective tissues bordered by astrocyte endfeet. The PVS, in a word, is the route over the arterioles, capillaries, and venules where the substances can move. Although the PVS was identified and described first in the literature approximately over 150 years ago, its importance has been highlighted recently after the function of the waste clearing system of the interstitial fluid and wastes was revealed. The PVS is known to be a microscopic structure detected using T2-weighted brain MRI as dot-like hyperintensity lesions when enlarged. Although until recently regarded as normal with no clinical consequence and ignored in many circumstances, several studies have argued the association of an enlarged PVS with neurodegenerative or other diseases. Many questions and unknown facts about this structure still exist; we can only assume that the normal PVS functions are crucial in keeping the brain healthy. In this review, we covered the history, anatomy, pathophysiology, and MRI findings of the PVS; finally, we briefly touched upon the recent trials to better visualize the PVS by providing a glimpse of the brain fluid dynamics and clinical importance of the PVS.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.20 no.6
• /
• pp.427-446
• /
• 2008

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2006 has been accomplished. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environments. The conclusions are as follows. (1) The research trends of fluid engineering have been surveyed as groups of general fluid flow, fluid machinery and piping, etc. New research topics include micro heat exchanger and siphon cooling device using nano-fluid. Traditional CFD and flow visualization methods were still popular and widely used in research and development. Studies about diffusers and compressors were performed in fluid machinery. Characteristics of flow and heat transfer and piping optimization were studied in piping systems. (2) The papers on heat transfer have been categorized into heat transfer characteristics, heat exchangers, heat pipes, and two-phase heat transfer. The topics on heat transfer characteristics in general include thermal transport in a cryo-chamber, a LCD panel, a dryer, and heat generating electronics. Heat exchangers investigated include pin-tube type, plate type, ventilation air-to-air type, and heat transfer enhancing tubes. The research on a reversible loop heat pipe, the influence of NCG charging mass on heat transport capacity, and the chilling start-up characteristics in a heat pipe were reported. In two-phase heat transfer area, the studies on frost growth, ice slurry formation and liquid spray cooling were presented. The studies on the boiling of R-290 and the application of carbon nanotubes to enhance boiling were noticeable in this research area. (3) Many studies on refrigeration and air conditioning systems were presented on the practical issues of the performance and reliability enhancement. The air conditioning system with multi indoor units caught attention in several research works. The issues on the refrigerant charge and the control algorithm were treated. The systems with alternative refrigerants were also studied. Carbon dioxide, hydrocarbons and their mixtures were considered and the heat transfer correlations were proposed. (4) Due to high oil prices, energy consumption have been attentioned in mechanical building systems. Research works have been reviewed in this field by grouping into the research on heat and cold sources, air conditioning and cleaning research, ventilation and fire research including tunnel ventilation, and piping system research. The papers involve the promotion of efficient or effective use of energy, which helps to save energy and results in reduced environmental pollution and operating cost. (5) Studies on indoor air quality took a great portion in the field of building environments. Various other subjects such as indoor thermal comfort were also investigated through computer simulation, case study, and field experiment. Studies on energy include not only optimization study and economic analysis of building equipments but also usability of renewable energy in geothermal and solar systems.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.19 no.2
• /
• pp.191-199
• /
• 1997

Mandibular trauma is developed due to traffic accident, fall down, industrial injury, and others. TMJ disorder is usually also developed after facial traumatic injury. Many authors suggested that disc displacement or tearing, acute synovitis, TMJ ankylosis, traumatic arthritis, or effusion are developed after facial trauma. It is still very controversible what is the best treatment of TMJ injury such as condylar fracture and meniscal injury. In TMJ injury, synovial inflammation is developed and pain mediators such as prostaglandin E2 or leukotriene B4 are released from the synovial membrane. This can be a cause of TMJ disorder. I present a variety of experimental study about the condylar fracture and meniscal injury and enzyme-immunoassay of synovial fluid after mandibular trauma that have been studied since 1992 and establish the treatment criteria of traumatic TMJ injury. I think that the treatment option of condylar fracture depends upon the surgeon's criteria exclusively. There are no significant differences between conservative and surgical treatment. If the aggressive functional physical therapy and long-term followup be performed, the favorable functional recovery of TMJ can be obtained. And I think that the initial surgical management of meniscus of TMJ is unnecessary in condylar fracture. And also arthrocentesis can be available to release the patient's subjective symptoms and improve the healing of injured TMJ.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.196.2-196.2
• /
• 2016

The design and development procedures of SF6 gas circuit breakers are still largely based on trial and error through testing although the development costs go higher every year. The computation cannot cover the testing satisfactorily because all the real processes arc not taken into account. But the knowledge of the arc behavior and the prediction of thermal plasmas inside SF6 interrupters by numerical simulations are more useful than those by experiments due to the difficulties to obtain physical quantities experimentally and the reduction of computational costs in recent years. In this paper, in order to get further information into the interruption process of a SF6 self-blast interrupter, which is based on the combination of thermal expansion and arc rotation, gas flow simulations with a CFD-arc modeling are performed during the whole switching process such as high-current period, pre-current zero period, and current-zero period. Through the complete work, the temperature of residual arcs as well as the breakdown index after current zero should be a good criterion to predict the dielectric capability of interrupters.

• Journal of computational fluids engineering
• /
• v.21 no.2
• /
• pp.106-111
• /
• 2016

Waste-to-energy facilities including incinerators are known as an efficient method to reduce wastes. In waste-to-energy facilities, more efficient cooling system is still needed for grates as the energy density of waste increased. For better cooling performance with the water-cooled grates, optimal design of cooling water pathways is highly beneficial. We performed numerical investigation on fluid flow and residence time of cooling water with change of the geometry of the cooling water pathway. With addition of round shaped guide vanes in the water pathway, the maximum residence time of flow is reduced(from 4.3 sec. to 2.4 sec.), but there is no significant difference in pressure drop between inlet and outlet, and average residence time at the outlet. Furthermore the flow stagnation region moves to the outlet, as the position of the round shaped guide vanes is located to the neck point of pathways.

• Journal of Power System Engineering
• /
• v.21 no.3
• /
• pp.60-65
• /
• 2017

A GA is one of the best method to find optimal value in searching area. A GA is driven by probabilistic selection that based on the survival of the fittest. So this algorithm need a huge solving time even if it can be used lots of optimizing problem such as structural design, machine learning, system's identification and so on. This GA's characteristic constrain the program to drive offline. Some studies try to use this algorithm on online or reduce the GA's running time with parallel GA or micro GA. Unfortunately these studies still didn't reduce amount of fitness solving. If the chromosome was imported to the system, it affected system's stability. And when the control system uses online GA, it also doesn't have enough learning time. In this study, try to find stability criterion to reduce the chromosome's affection and find the characteristic of the number of population and generation when GA was driven into the wide searching area.