http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Optical Consequences of Korean Craniofacial Features
Kwok, L. Stephen,Kim, Douk-Hoon The Korean Ophthalmic Optics Society 2005 한국안광학회지 Vol.10 No.2
This review of the Korean eye anatomy suggests that there may be unsuspected links between anatomical characteristics of the eye and orbit, and optical performance.
Can Growth of a Trading Partner Harm a Country?
( Kwok Tong Soo ) 세종대학교 경제통합연구소 (구 세종대학교 국제경제연구소) 2008 Journal of Economic Integration Vol.23 No.1
Can growth of a trading partner harm a country? This paper seeks to answer this question through the use of an eclectic trade model which is similar in flavour to Markusen (1986). This paper makes two contributions. First, it develops a simple and tractable model of international trade based on a combination of imperfect competition, comparative advantage, and identical but non-homothetic preferences in a three country framework. Second, it uses this framework to consider the possibility of losses from partner-country growth in a free-trading environment. We find that the presence of nonhomothetic preferences in particular, leads to a home bias in consumption which dampens any negative welfare effects when a country`s trading partners grow.
Sliding Wear and Corrosion Resistance of Copper-based Overhead Catenary for Traction Systems
Kwok, C.T.,Wong, P.K.,Man, H.C.,Cheng, F.T. The Korean Society for Railway 2010 International Journal of Railway Vol.3 No.1
In the present study, the electrical sliding wear and corrosion resistance of pure copper (Cu) and six age-hardened copper alloys (CuCr, CuZr, CuCrZr, CuNiSiCr, CuBe and CuBeNi) were investigated by a pin-on-disc tribometer and electrochemical measurement. Various copper-based alloys in the form of cylindrical pin were forced to slide against a counterface stainless steel disc in air under unlubricated condition at a sliding velocity of 31 km/h under normal load up to 20 N with and without electric current. The worn surface of and wear debris from the specimens were studied by scanning electron microscopy. Both mechanical wear and electrical arc erosion were the wear mechanisms for the alloys worn at 50 A. Owing to its good electrical conductivity, high wear and corrosion resistance, CuCrZr is a promising candidate as the overhead catenary material for electric traction systems.
Kwok, Seung-Ki,Seo, Soo-Hong,Ju, Ji Hyeon,Yoon, Chong-Hyeon,Park, Soo Chul,Kim, Bum Soo,Kim, Ho-Youn,Park, Sung-Hwan The Korean Academy of Medical Sciences 2008 JOURNAL OF KOREAN MEDICAL SCIENCE Vol.23 No.1
<P>Cryptococcal meningitis is a rare complication of systemic lupus erythematosus (SLE). The nonspecific neurologic findings associated with this infection delays accurate diagnosis because initial neuropsychiatric manifestations of SLE are in instances indistinguishable from that of crytococcal meningitis. We report a case of cryptococcal meningitis presenting with unilateral sixth cranial nerve palsy in a male patient with SLE, which was successfully treated with antifungal agents.</P>
Kwok, SK,Shin, YJ,Kim, HJ,Kim, HS,Kim, JY,Yoo, SA,Choi, JJ,Kim, WU,Cho, CS SAGE Publications 2009 Lupus Vol.18 No.2
<P>Patients with antiphospholipid syndrome (APS) have an increased risk for the development of thrombotic complications. Recent studies indicate that osteoprotegerin (OPG) acts as an important molecule in the development of vascular diseases. The aim of the present study was to examine the association between serum OPG levels and APS manifestations in patients with SLE. Seventy-nine patients with SLE and ninety-two healthy controls, matched for age and sex, were included in this study. Serum levels of OPG, monocyte chemoattractant protein(MCP)-1 and soluble E-selectin were determined by ELISA. At the time of serum sampling, various clinical and laboratory parameters were assessed. We found that serum levels of OPG were significantly higher in patients with SLE than in healthy controls (1236?±?82 vs 967?±?37?pg/mL, <I>P</I>?=?0.003). Particularly, serum OPG levels were significantly higher in SLE patients with APS than those without (1615?±?191 vs 1171?±?91?pg/mL, <I>P</I>?=?0.006). Serum OPG levels correlated with titres of IgG anti-cardiolipin antibody (<I>P</I>?=?0.026) and anti-β<SUB>2</SUB>-glycoprotein I antibody (<I>P</I>?<?0.001). Moreover, serum OPG also correlated with serum levels of sE-selectin (<I>P</I>?=?0.002), which is an endothelial cell activation marker, and MCP-1 (<I>P</I>?=?0.003), a well known chemokine implicated in thrombogenesis. Collectively, serum OPG levels were increased in SLE patients with APS and correlated with titres of antiphospholipid antibodies, suggesting that OPG might be linked to the development of APS.</P>
PLANETARY NEBULAE: NEW CHALLENGES IN THE 21ST CENTURY
KWOK SUN The Korean Astronomical Society 2005 Journal of The Korean Astronomical Society Vol.38 No.2
Athough planetary nebulae (PNe) have been discovered for over 200 years, it was not until 30 years ago that we arrived at a basic understanding of their origin and evolution. Even today, with observations covering the entire electromagnetic spectrum from radio to X-ray, there are still many unanswered questions on their structure and morphology. In this review, we summarize recent theoretical and observational advances in PNe research, and discuss the roles of PNe in the chemical (atomic, molecular, and solid-state) enrichment of the galaxy and as tracers of the large scale structure of the Universe.
Kwok, Seung‐,Ki,Cho, Mi‐,La,Park, Mi‐,Kyung,Oh, Hye‐,Joa,Park, Jin‐,Sil,Her, Yang‐,Mi,Lee, Seon‐,Yeong,Youn, Jeehee,Ju, Ji Hyeon,Park, Kyung Su,Kim, Sung Wiley Subscription Services, Inc., A Wiley Company 2012 Vol.64 No.3
<P><B>Abstract</B></P><P><B>Objective</B></P><P>Bone destruction is a critical pathology involved in the functional disability caused by rheumatoid arthritis (RA). Osteoclasts, which are specialized bone‐resorbing cells regulated by cytokines such as RANKL, are implicated in bone destruction in RA. The aim of this study was to determine whether interleukin‐21 (IL‐21), a potent immunomodulatory 4–α‐helical bundle type 1 cytokine, has osteoclastogenic activity in patients with RA and in mice with collagen‐induced arthritis (CIA).</P><P><B>Methods</B></P><P>The expression of IL‐21 in synovial tissue was examined using immunohistochemistry. The concentrations of IL‐21 in serum and synovial fluid were determined by enzyme‐linked immunosorbent assay. The levels of RANKL and osteoclastogenic markers were measured using real‐time polymerase chain reaction. CD14+ monocytes from patients with RA or mouse bone marrow cells were cocultured with fibroblast‐like synoviocytes (FLS) from patients with RA or CD4+ T cells from mice with CIA in the presence of IL‐21 and subsequently stained for tartrate‐resistant acid phosphatase activity to determine osteoclast formation.</P><P><B>Results</B></P><P>IL‐21 was up‐regulated in the synovium, synovial fluid, and serum of patients with RA and in the synovium and serum of mice with CIA. IL‐21 induced RANKL expression in mixed joint cells and CD4+ T cells from mice with CIA and in CD4+ T cells and FLS from patients with RA. Moreover, IL‐21 enhanced in vitro osteoclastogenesis without the presence of RANKL‐providing cells and by inducing RANKL expression in CD4+ T cells and FLS.</P><P><B>Conclusion</B></P><P>Our data suggest that IL‐21 promotes osteoclastogenesis in RA. We believe that therapeutic strategies targeting IL‐21 might be effective for the treatment of patients with RA, especially in preventing bone destruction.</P>
Kwok, Seung-Ki,Cho, Mi-La,Her, Yang-Mi,Oh, Hye-Joa,Park, Mi-Kyung,Lee, Seon-Yeong,Woo, Yun Ju,Ju, Ji Hyeon,Park, Kyung-Su,Kim, Ho-Youn,Park, Sung-Hwan BioMed Central 2012 ARTHRITIS RESEARCH AND THERAPY Vol.14 No.2
<P><B>Introduction</B></P><P>The study was undertaken to investigate the interrelation of toll-like receptor (TLR) and interleukin (IL)-17 in the salivary glands of patients with primary Sjogren's syndrome (pSS) and to determine the role of TLR and IL-17 in the pathophysiology of pSS.</P><P><B>Methods</B></P><P>The expressions of various TLRs, IL-17 and the cytokines involved in Th17 cell differentiation including IL-6, IL-23, tumor necrosis factor-alpha (TNF-α) and IL-1β were examined by immunohistochemistry in salivary glands of pSS patients. The IL-17 producing CD4+ T cells (Th17 cells) were examined by flow cytometry and confocal staining in peripheral mononuclear blood cells (PMBCs) and salivary glands of pSS patients. After PBMCs were treated with TLR specific ligands, the induction of IL-17 and IL-23 was determined using real-time PCR and ELISA. The signaling pathway that mediates the TLR2 stimulated production of IL-17 and IL-23 was investigated by using treatment with specific signaling inhibitors.</P><P><B>Results</B></P><P>We showed that TLR2, TLR4, TLR6, IL-17 and the cytokines associated with Th17 cells were highly expressed in salivary glands of pSS patients but not in controls. The expressions of TLR2, TLR4 and TLR6 were observed in the infiltrating mononuclear cells and ductal epithelial cells, whereas IL-17 was mainly observed in infiltrating CD4+ T cells. The number of IL-17 producing CD4+ T cells was significantly higher in pSS patients both in PBMCs and minor salivary glands. The stimulation of TLR2, TLR4 and TLR6 additively induced the production of IL-17 and IL-23 from the PBMCs of pSS patients especially in the presence of TLR2 stimulation. IL-6, signal transducer and activator of transcription 3 (STAT3) and nuclear factor-kappaB (NF-kB) pathways were implicated in the TLR2 stimulated IL-17 and IL-23.</P><P><B>Conclusions</B></P><P>Our data demonstrate that TLR2 ligation induces the production of IL-23/IL-17 via IL-6, STAT3 and NF-kB pathway in pSS. Therefore, therapeutic strategies that target TLR/IL-17 pathway might be strong candidates for treatment modalities of pSS.</P>