• Title/Summary/Keyword: literature evidence

Search Result 1,290, Processing Time 0.033 seconds

Spin and shape analysis for the Mars-crossing asteroid 2078 Nanking

  • Choi, Jung-Yong;Kim, Myung-Jin;Choi, Young-Jun;Yoon, Tae Seog
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.40 no.1
    • /
    • pp.85.2-86
    • /
    • 2015
  • The YORP effect is non-gravitational force that changes the spin-status of asteroid. So far this effect has been directly detected only from the Near-Earth asteroids (Taylor et al. 2007; Lowry et al. 2007, 2014; Breiter et al. 2011; Durech et al. 2008, 2012). Pravec at el. 2008 found the evidences for changing spin rate of small asteroids (3 - 15 km) by the YORP effect in the Main-Belt and Mars-crossing asteroids. The Mars-crossing asteroids (1.3 < q < 1.66 AU) are objects that cross orbit of the Mars. The Mars-crossing asteroids are regarded as one of the main sources for the Near-Earth asteroids. We expect that rotation of Mars-crossing asteroids would be influenced by the YORP effect. We try to search observational evidence of the YORP effect for the Mars-crossing asteroid. Our target 2078 Nanking is a population of the Mars-crossing asteroid. First light-curve of 2078 Nanking was obtained from Mohamed et al. 1994, and Warner et al. 2015 recently published new observational data. We observed this asteroid on 26th Nov. 2014 and 17th Jan. 2015 using SOAO (Sobaeksan Optical Astronomy Observatory) 0.61 m telescope with 4K CCD. Using light-curve inversion method (Kaasalainen & Torppa 2001; Kaasalainen et al. 2001), we try to determine the pole orientation and shape model of this asteroid based on the combination of our light-curve and literature photometric data. Knowing spin parameters, such as rotational period and spin axis, are essential for studying the YORP effect. In this presentation, we provide some preliminary results of our recent study: light-curve and processing of shape modeling of 2078 Nanking. We plan to find observational clue for the YORP effect on the Mars-crossing asteroids.

  • PDF

Evaluation of Human Factors for the Next-Generation Displays: A Review of Subjective and Objective Measurement Methods

  • Mun, Sungchul;Park, Min-Chul
    • Journal of the Ergonomics Society of Korea
    • /
    • v.32 no.2
    • /
    • pp.207-215
    • /
    • 2013
  • Objective: This study aimed to investigate important human factors that should be considered when developing ultra-high definition TVs by reviewing measurement methods and main characteristics of ultra-high definition displays. Background: Although much attention has been paid to high-definition displays, there have been few studies for systematically evaluating human factors. Method: In order to determine human factors to be considered in developing human-friendly displays, we reviewed subjective and objective measurement methods to figure out the current limitations and establish a guideline for developing human-centered ultra-high definition TVs. In doing so, pros and cons of both subjective and objective measurement methods for assessing humans factors were discussed and specific aspects of ultra-high definition displays were also investigated in the literature. Results: Hazardous effects such as visually-induced motion sickness, visual fatigue, and mental fatigue in the brain caused by undesirable TV viewing are induced by not only temporal decay of visual function but also cognitive load in processing sophisticated external information. There has been a growing evidence that individual differences in visual and cognitive ability to process external information can make contrary responses after exposing to the same viewing situation. A wide vision, ultra-high definition TVs provide, can has positive and negative influences on viewers depending on their individual characteristics. Conclusion: Integrated measurement methods capable of considering individual differences in human visual system are required to clearly determine potential effects of super-high vision displays with a wide view on humans. All of brainwaves, autonomic responses, eye functions, and psychological responses should be simultaneously examined and correlated. Application: The results obtained in this review are expected to be a guideline for determining optimized viewing factors of ultra-high definition displays and accelerating successful penetration of the next-generation displays into our daily life.

MicroRNAs in Human Diseases: From Cancer to Cardiovascular Disease

  • Ha, Tai-You
    • IMMUNE NETWORK
    • /
    • v.11 no.3
    • /
    • pp.135-154
    • /
    • 2011
  • The great discovery of microRNAs (miRNAs) has revolutionized current cell biology and medical science. miRNAs are small conserved non-coding RNA molecules that post-transcriptionally regulate gene expression by targeting the 3' untranslated region of specific messenger RNAs for degradation or translational repression. New members of the miRNA family are being discovered on a daily basis and emerging evidence has demonstrated that miRNAs play a major role in a wide range of developmental process including cell proliferation, cell cycle, cell differentiation, metabolism, apoptosis, developmental timing, neuronal cell fate, neuronal gene expression, brain morphogenesis, muscle differentiation and stem cell division. Moreover, a large number of studies have reported links between alterations of miRNA homeostasis and pathological conditions such as cancer, psychiatric and neurological diseases, cardiovascular disease, and autoimmune disease. Interestingly, in addition, miRNA deficiencies or excesses have been correlated with a number of clinically important diseases ranging from cancer to myocardial infarction. miRNAs can repress the gene translation of hundreds of their targets and are therefore well-positioned to target a multitude of cellular mechanisms. As a consequence of extensive participation in normal functions, it is quite logical to ask the question if abnormalities in miRNAs should have importance in human diseases. Great discoveries and rapid progress in the past few years on miRNAs provide the hope that miRNAs will in the near future have a great potential in the diagnosis and treatment of many diseases. Currently, an explosive literature has focussed on the role of miRNA in human cancer and cardiovascular disease. In this review, I briefly summarize the explosive current studies about involvement of miRNA in various human cancers and cardiovascular disease.

Fundamentals and Research Trend of Laser Acupuncture (레이저침의 원리와 연구동향 분석)

  • Kim, Hyun-Ho;Nam, Dong-Woo;Lee, Sang-Hoon
    • Journal of Acupuncture Research
    • /
    • v.26 no.6
    • /
    • pp.21-30
    • /
    • 2009
  • Objectives : Being introduced in the 1980s, laser acupuncture studies have been steadily carried on such as its thermal effects on human body. However, the mechanisms of effect are not yet clearly explained. Generally, laser acupuncture could be favorable for pediatric patients or people under special conditions (hemophilia, needle-phobia, pathogen-carriers, etc.) because of lower risk of infection, bleeding, pain or fainting. But there are still problems for using laser acupuncture equivalently as the traditional metal needle. The goal of this study is to review the fundamentals, history and present trend of laser acupuncture study, and to suggest how to develop laser acupuncture as an oriental medical device. Method : We performed literature search using PubMed(http://www.ncbi.nlm.nih.gov/pubmed) and Scopus(http://www.scopus.com). Search conditions are laser acupuncture, laser needle, LLLT(as title or abstract) or Litscher G(as author). Main target studies are physical fundamentals, clinical trials, physiological results and device proposals. Results : Many research have shown the similarities of laser acupuncture and traditional metal acupuncture and have reported clinical and physiological effects of laser acupuncture. But, still laser acupuncture is not widely used in Korea due to high-cost of equipments and the lack of clear understanding of laser devices. Additionally, there are still challenges in standardization and device development. Conclusions : Frequencies, laser modes, waveguides, adaptor types, polarization and signal modulations are suggested as future study subjects on laser acupuncture. More various studies and efforts for device development have to be performed to provide oriental medical doctors with evidence based confidence about usage of laser acupuncture.

  • PDF

HISTOLOGIC STUDY OF THE AUTOGENOUS AURICULAR CARTILAGE GRAFTS IN THE RABBITS FEMER (가토 대퇴골에 이식한 자가 이연골에 관한 조직학적 연구)

  • Sung, Gil-Hyun;Kim, Eun-Cheol;Min, Seung-Ki;Lee, Dong-Keun;Kim, Soo-Nam
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.15 no.1
    • /
    • pp.49-61
    • /
    • 1993
  • The transplantation of cartilage, especially auricular cartilage, has assumed a role of importance in the field of plastic and reconstructive surgery. From long years ago, many reports have appeared in the literature describing the experimental and clinical results of the use of cartilage. At present, the evidence for survival of autograft of cartilage is admitted, But, the results for interrelationship between the bone and cartilage grafts with or without perichondrium is not so conclusive. The purpose of this study were observed as to whether autogenous cartilage grafts were fixed by means of tie with 4-0 vicryl and fibrin adhesive on the femur or microscopic findings of union state in 16 rabbits. We sacrified the experimental animals after 1, 2, 4, 6 weeks postoperatively and made the specimens as a routine laboratory procedures and stained with Hematoxylin-Eosin stain, Verhoeff-van Gieson elastic fiber stain, and alcian blue periodic acid-Schiff(AB-PAS) for mucopolysaccharide. Histologic evaluation was performed under microscope. The obtaind results were as follows : 1. Fibrous union was formed between the grafting cartilage and the femur, nor any findings of calcification and formation of new bone. 2. Partial fibrous adhesion was observed in fibrin adhesive groups on 6 weeks postoperatively. 3. Appositional growth has performed more in fibrin adhesive groups than tie groups. 4. There are little difference in both for new copillary proliferation and fibroblast activations. 5. Degenerative changes have apperared more in tie groups than adhesive groups, but not related to the healing periods.

  • PDF

A CASE REPORT OF MAXILLARY LEIOMYOSARCOMA WITH REGIONAL LYMPH NODE METASTASIS (국소 림프절 전이를 보이는 상악 평활근 육종에 대한 증례보고)

  • Park, Soong;Lee, Baek-Soo;Kim, Yeo-Gap;Kwon, Yong-Dae;Choi, Byung-Joon;Kim, Young-Ran
    • Maxillofacial Plastic and Reconstructive Surgery
    • /
    • v.32 no.2
    • /
    • pp.183-188
    • /
    • 2010
  • Leiomyosarcoma is a malignant neoplasm of smooth muscle origin and mostly originate from the wall of uterus and gastrointestinal tract, but primary leiomyosarcoma of the oral cavity is extremely rare. This tumor has a very poor prognosis due to high recurrence and metastasis rate, with 5 year survival rate of 32%. And regional lymph node metastasis is uncommon event. Complete wide surgical excision is the treatment of choice. A 64-year old man who had a painful ulcerative lesion on the labial & palatal gingiva of #11, 21 visited our department, and was diagnosed as leiomyosarcoma through a biopsy. Partial maxillectomy was carried out, with no following radiotherapy or chemotherapy. After months follow-up, there has been no evidence of recurrence or metastasis. But after months, we clinically find out two enlarged immobile palpable lymph node in right submandibular area of patient. So a biopsy was performed via an extraoral incision under local anesthesia. Histopathologic diagnosis diagnosis of the biopsy was lymph node metastasis of prior existed leiomyosarcoma. We report a case of a primary leiomyosarcoma occurred in a 64 year-old male patient involving the anterior maxillary region with regional lymph node metastasis with a review of literature.

The Effects of Perceived Quality toward User Performance and Corporate Performance in Production Information Systems (생산정보시스템에 대한 품질인식이 사용자 성과와 기업성과에 미치는 영향)

  • Jung, Chul-Ho
    • Journal of Digital Convergence
    • /
    • v.10 no.8
    • /
    • pp.45-52
    • /
    • 2012
  • The purpose of this study is to investigate the perceived quality toward user performance and corporate performance in production information systems. For this purpose, a research model and hypotheses are developed based on the relevant literature reviews. Data have been collected from 132 enterprises which have implemented production information systems, and the research hypotheses were tested by covariance structural model analysis. The results of this empirical study are summarized as follows. First, production information quality and support service quality are confirmed to have a positive effect on user's satisfaction, however, I found no evidence of a statistically significant relationship between system quality and user's satisfaction. Second, all of three quality factors which are production information quality, system quality, and support service quality have positive influence on system usage. Third, user's satisfaction has positive influence on system usage, and both of user's satisfaction and system usage have positive influence on performance improvement. Based on these findings, this study suggested the implications, as well as limitations and further research directions.

NEURODEVELOPMENTAL PERSPECTIVE OF ATTENTION-DEFICIT/HYPERACTIVITY DISORDER(ADHD) (주의력결핍-과잉행동장애의 신경발달학적 고찰)

  • Ahn, Dong-Hyun
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
    • /
    • v.16 no.2
    • /
    • pp.160-172
    • /
    • 2005
  • Attention-Deficit/Hyperactivity Disorder(ADHD) is the most common neurodevelopmental disorder in child psychiatry. The etiology or ADHD is not completely understood, but involved in genetical and/or neurocognitive deficits. This article reviews the current state of the literature pertaining to the neurodevelopmental aspects of ADHD. Although the neurodevelopment of ADHD remains unclear, emerging evidence documents its genetic and neurobiologic underpinnings. A pathophysiology of ADHD has not been fully characterized, although genetic, neurobiologic, neuroimaging, and neuropsychological studies of ADHD consistently implicates dysfunction in the fronto-subcortical network and abnormality in the dopaminergic and noradnergic systems. Furthermore some suggests that the timing of aberrant brain development in ADHD could be in early gestation and genetic and/or early environmental influences on brain development in ADHD are fixed, nonprogressive. Although many studies provide evidences for the important or psychosocial or environmental adversities in ADHD, they may be not specific predictors of ADHD but nonspecific triggers of an underlying predisposition or modifiers of the course of disorder.

  • PDF

The Revised Korean Practice Parameter for the Treatment of Attention-Deficit Hyperactivity Disorder (III) - Pharmacological Treatment - (주의력결핍 과잉행동장애 한국형 치료 권고안 개정안(III) - 약물치료 -)

  • Kim, Hyo-Won;Kim, Eunjoo;Kim, Ji-Hoon;Park, Jangho;Bahn, Geon Ho;Lee, Yeon Jung;Jhung, Kyungun;Shin, Dongwon
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
    • /
    • v.28 no.2
    • /
    • pp.70-83
    • /
    • 2017
  • The objective of this review is the revision of the Korean practice parameters for the pharmacological treatment of attention-deficit hyperactivity disorder (ADHD) based on the change in the diagnostic system from DSM-IV-TR to DSM-5 and psychopharmacological developments. For the evidence-based approach, the authors conducted a review of the literature, including controlled clinical trials, studies of the side effects of drugs, toxicology and meta-analyses from the United States and Europe, as well as recent research conducted in Korea. The review committee composed of Korean experts on ADHD reviewed the revised parameters. This revised version reveals how to use central nervous system psychostimulants, non-stimulants such as atomoxetine and alpha2 agonists, and other medication for ADHD, and how to manage the adverse effects of such medication. At the end of this revised version, the authors propose recommendations for the pharmacotherapy of ADHD.

microRNA Expression Profile in Patients with Stage II Colorectal Cancer: A Turkish Referral Center Study

  • Tanoglu, Alpaslan;Balta, Ahmet Ziya;Berber, Ufuk;Ozdemir, Yavuz;Emirzeoglu, Levent;Sayilir, Abdurrahim;Sucullu, Ilker
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.16 no.5
    • /
    • pp.1851-1855
    • /
    • 2015
  • Background: There are increasing data about microRNAs (miRNA) in the literature, providing abundant evidence that they play important roles in pathogenesis and development of colorectal cancer. In this study, we aimed to investigate the miRNA expression profiles in surgically resected specimens of patients with recurrent and non-recurrent colorectal cancer. Materials and Methods: The study population included 40 patients with stage II colorectal cancer (20 patients with recurrent tumors, and 20 sex and age matched patients without recurrence), who underwent curative colectomy between 2004 and 2011 without adjuvant therapy. Expression of 16 miRNAs (miRNA-9, 21, 30d, 31, 106a, 127, 133a, 133b, 135b, 143, 145, 155, 182, 200a, 200c, 362) was verified by quantitative real-time polymerase chain reaction (qRT-PCR) in all resected colon cancer tissue samples and in corresponding normal colonic tissues. Data analyses were carried out using SPSS 15 software. Values were statistically significantly changed in 40 cancer tissues when compared to the corresponding 40 normal colonic tissues (p<0.001). MiR-30d, miR-133a, miR-143, miR-145 and miR-362 expression was statistically significantly downregulated in 40 resected colorectal cancer tissue samples (p<0.001). When we compared subgroups, miRNA expression profiles of 20 recurrent cancer tissues were similar to all 40 cancer tissues. However in 20 non-recurrent cancer tissues, miR-133a expression was not significantly downregulated, moreover miR-133b expression was significantly upregulated (p<0.05). Conclusions: Our study revealed dysregulation of expression of ten miRNAs in Turkish colon cancer patients. These miRNAs may be used as potential biomarkers for early detection, screening and surveillance of colorectal cancer, with functional effects on tumor cell behavior.