489 research outputs found

    Noise Source Identification of Small Fan-BLDC Motor System for Refrigerators

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    Noise levels in household appliances are increasingly attracting attention from manufacturers and customers. Legislation is becoming more severe on acceptable noise levels and low noise is a major marketing point for many products. The latest trend in the refrigerator manufacturing industry is to use brushless DC (BLDC) motors instead of induction motors in order to reduce energy consumption and noise radiation. However, cogging torque from BLDC motor is an undesirable effect that prevents the smooth rotation of the rotor and results in noise. This paper presents a practical approach for identifying the source of excessive noise in the small fan-motor system for household refrigerators. The source is presumed to a mechanical resonance excited by torque ripple of the BLDC motor. By using finite element analysis, natural frequencies and mode shapes of the rotating part of the system are obtained and they are compared with experimental mode shapes obtained by electronic torsional excitation test which uses BLDC motor itself as an exciter. Two experimental validations are carried out to confirm the reduction of excessive noise

    Novel water filtration of saline water in the outermost layer of mangrove roots

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    The scarcity of fresh water is a global challenge faced at present. Several desalination methods have been suggested to secure fresh water from sea water. However, conventional methods suffer from technical limitations, such as high power consumption, expensive operating costs, and limited system durability. In this study, we examined the feasibility of using halophytes as a novel technology of desalinating high-concentration saline water for long periods. This study investigated the biophysical characteristics of sea water filtration in the roots of the mangrove Rhizophora stylosa from a plant hydrodynamic point of view. R. stylosa can grow even in saline water, and the salt level in its roots is regulated within a certain threshold value through filtration. The root possesses a hierarchical, triple layered pore structure in the epidermis, and most Na+ ions are filtered at the first sublayer of the outermost layer. The high blockage of Na+ ions is attributed to the high surface zeta potential of the first layer. The second layer, which is composed of macroporous structures, also facilitates Na+ ion filtration. This study provides insights into the mechanism underlying water filtration through halophyte roots and serves as a basis for the development of a novel bio-inspired desalination method.Creative Research Initiative (Diagnosis of Biofluid Flow Phenomena and Biomimic Research) of the Ministry of Science, ICT and Future Planning (MSIP) , National Research Foundation (NRF) of Korea , ICT R&D program of MSIP/IITP (Korea

    Usefulness of Bone Metabolic Markers in the Diagnosis of Bone Metastasis from Lung Cancer

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    Bone metastasis is common in lung cancer patient and the diagnosis of bone metastasis is usually made by using imaging techniques, especially bone scintigraphy. However, the diagnostic yield from bone scintigraphy is limited. The aim of this study is to assess the clinical usefulness of urinary pyridinoline cross-linked N-telopeptides of Type I collagen (NTx), urinary deoxypyridinoline (DPD), and serum alkaline phosphatase (ALP) in the assessment of bone metastasis in patients with lung cancer. Urinary NTx, DPD, and serum ALP were measured in 151 lung cancer patients (33 with and 118 without bone metastasis). Lung cancer patients with bone metastasis had a higher urinary excretion of NTx and DPD, and a higher serum ALP than those without bone metastasis. NTx had a better receiver operating characteristic (ROC) curve than DPD and ALP, since the areas under the ROC curve were 0.82, 0.79, and 0.71, respectively. Although correlation coefficients among NTx, DPD and ALP were significantly positive (p < 0.005), the strongest relationship was appeared between NTx and DPD (R=0.616). In conclusion, our results showed the utility of the new bone markers in detecting bone metastasis and suggested that measurement of urinary NTx was valid diagnostic method of bone metastasis from lung cancer

    The Practice of Korean Medicine: An Overview of Clinical Trials in Acupuncture

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    Acupuncture, one of the Oriental medical therapeutic techniques that can be traced back at least 2500 years, is growing in popularity all over the world. Korea has continued to develop its own unique tradition of medicine throughout its long history, and has formed different types of acupuncture methods. The purpose of this review is to summarize clinical case studies in acupuncture and related therapies, such as acupressure, electric acupuncture, auricular acupuncture and moxibustion in Korea. A survey of Korean journals revealed that a total of 124 studies were published from 1983 to 2001. Results obtained from the survey showed that most clinical studies using acupuncture, electric acupuncture, moxibustion and other traditional therapies could alleviate a relatively broad range of medical problems. However, it should be emphasized that almost all clinical case studies published in various local journals did not follow the β€˜good clinical practice’ with respect to regulatory aspects. Since they were not conducted using the randomized double-blinded controls with a large sample size, all the results should be considered as therapeutic indications. This review is an attempt to show the scope of acupuncture in our country and the kind of diseases, after many years of clinical experience, that were deemed valid targets for clinical trials

    Nonspecific Interstitial Pneumonitis after Bortezomib and Thalidomide Treatment in a Multiple Myeloma Patient

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    Bortezomib, an inhibitor of 26S proteosome, is recently approved treatment option for multiple myeloma. Thalidomide, a drug with immunomodulating and antiangiogenic effects, has also shown promise as an effective treatment in multiple myeloma. Pulmonary complications are believed to be rare, especially interstitial lung disease. Here, we describe a patient with dyspnea and diffuse pulmonary infiltrates while receiving bortezomib and thalidomide in combination with dexamethasone for treatment-naΓ―ve multiple myeloma. Bronchoalveolar lavage demonstrated a significant decrease in the ratio of CD4 : CD8 T lymphocytes (CD4/8 ratio, 0.54). Extensive workup for other causes, including infections, was negative. A lung biopsy under video-assisted thorascopic surgery revealed a diagnosis of nonspecific interstitial pneumonitis. The symptoms and imaging study findings improved after initiating steroid treatment. Physicians should be aware of this potential complication in patients receiving the novel molecular-targeted antineoplastic agents, bortezomib and thalidomide, who present with dyspnea and new pulmonary infiltrates and fail to improve despite treatment with broad-spectrum antibiotics

    FBXW7-mediated ERK3 degradation regulates the proliferation of lung cancer cells

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    Extracellular signal-regulated kinase 3 (ERK3) is an atypical member of the mitogen-activated protein kinase (MAPK) family, members of which play essential roles in diverse cellular processes during carcinogenesis, including cell proliferation, differentiation, migration, and invasion. Unlike other MAPKs, ERK3 is an unstable protein with a short half-life. Although deubiquitination of ERK3 has been suggested to regulate the activity, its ubiquitination has not been described in the literature. Here, we report that FBXW7 (F-box and WD repeat domain-containing 7) acts as a ubiquitination E3 ligase for ERK3. Mammalian two-hybrid assay and immunoprecipitation results demonstrated that ERK3 is a novel binding partner of FBXW7. Furthermore, complex formation between ERK3 and the S-phase kinase-associated protein 1 (SKP1)-cullin 1-F-box protein (SCF) E3 ligase resulted in the destabilization of ERK3 via a ubiquitination-mediated proteasomal degradation pathway, and FBXW7 depletion restored ERK3 protein levels by inhibiting this ubiquitination. The interaction between ERK3 and FBXW7 was driven by binding between the C34D of ERK3, especially at Thr417 and Thr421, and the WD40 domain of FBXW7. A double mutant of ERK3 (Thr417 and Thr421 to alanine) abrogated FBXW7-mediated ubiquitination. Importantly, ERK3 knockdown inhibited the proliferation of lung cancer cells by regulating the G1/S-phase transition of the cell cycle. These results show that FBXW7-mediated ERK3 destabilization suppresses lung cancer cell proliferation in vitro

    Biliary complications in living donor liver transplantation: imaging findings and the roles of interventional procedures

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    PURPOSE: To describe the incidence, types, and findings of biliary complications in living donor liver transplantation (LDLT) and to determine the roles of interventional procedures. MATERIALS AND METHODS: Twenty-four biliary complications among 161 LDLT patients (24/161, 14.9%) were identified. These complications were divided into two groups according to the initial manifestation time, i.e., "early" (<60 days) or "late". The CT and cholangiographic findings were reviewed regarding the presence of a stricture or leak and the location, and length, shape, and degree of the stricture. Both groups were categorized into three subgroups: leak, stricture, and both. The type of interventional procedures used and their roles were determined. RESULTS: Early complications were identified in 14 of the 24 patients (58%) and late complications in 11 (46%). One patient showed both early and late complications. Biliary stricture was detected in 10 patients, leak in 10, and both in 5. By cholangiography, all strictures were irregular and short (mean length 15 +/- 6 mm) at the anastomotic site and complete obstruction was observed in 2 patients with late stricture. Twenty-three of the 24 patients were treated using percutaneous and/or endoscopic drainage procedures with or without balloon dilatation. Seventeen (74%) showed a good response, but reoperations were inevitable in 6 (26%). All patients except those with complete obstruction showed a favorable outcome after interventional management. CONCLUSION: Biliary leaks and strictures are predominant complications in LDLT. Most show good responses to interventional treatment. However, complete obstruction needs additional operative management
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