• 제목/요약/키워드: negative-effective-mass

검색결과 95건 처리시간 0.024초

Prevalence, Pathophysiology, Screening and Management of Osteoporosis in Gastric Cancer Patients

  • Lim, Jung-Sub;Lee, Jong-Inn
    • Journal of Gastric Cancer
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    • 제11권1호
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    • pp.7-15
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    • 2011
  • Osteoporosis in gastric cancer patients is often overlooked or even neglected despite its high prevalence in these patients. Considering that old age, malnutrition, chronic disease, chemotherapy, decreased body mass index and gastrectomy are independent risk factors for osteoporosis, it is reasonable that the prevalence of osteoporosis in gastric cancer patients would be high. Many surviving patients suffer from back pain and pathological fractures, which are related to osteoporosis. Fractures have obvious associated morbidities, negative impact on quality of life, and impose both direct and indirect costs. In the era of a >55.6% 5-year survival rate of gastric cancer and increased longevity in gastric cancer patients, it is very important to eliminate common sequelae such as osteoporosis. Fortunately, the diagnosis of osteoporosis is well established and many therapeutic agents have been shown to be effective and safe not only in postmenopausal females but also in elderly males. Recently, effective treatments of gastric cancer patients with osteoporosis using bisphosphonates, which are commonly used in postmenopausal woman, were reported.

HPV Vaccination for Cervical Cancer Prevention is not Cost-Effective in Japan

  • Isshiki, Takahiro
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권15호
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    • pp.6177-6180
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    • 2014
  • Background: Our study objectives were to evaluate the medical economics of cervical cancer prevention and thereby contribute to cancer care policy decisions in Japan. Methods: Model creation: we created presence-absence models for prevention by designating human papillomavirus (HPV) vaccination for primary prevention of cervical cancer. Cost classification and cost estimates: we divided the costs of cancer care into seven categories (prevention, mass-screening, curative treatment, palliative care, indirect, non-medical, and psychosocial cost) and estimated costs for each model. Cost-benefit analyses: we performed cost-benefit analyses for Japan as a whole. Results: HPV vaccination was estimated to cost $291.5 million, cervical cancer screening $76.0 million and curative treatment $12.0 million. The loss due to death was $251.0 million and the net benefit was -$128.5 million (negative). Conclusion: Cervical cancer prevention was not found to be cost-effective in Japan. While few cost-benefit analyses have been reported in the field of cancer care, these would be essential for Japanese policy determination.

Evaluation of Computational Fluid Dynamics for Analysis of Aerodynamics in Naturally Ventilated Multi-span Greenhouse

  • Lee, In Bok;Short, Ted H.;Sase, Sadanori;Lee, Seung Kee
    • Agricultural and Biosystems Engineering
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    • 제1권2호
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    • pp.73-80
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    • 2000
  • Aerodynamics in a naturally ventilated multi-span greenhouse with plants was analyzed numerically by the computational fluid dynamics (CFD) simulation. To investigate the potential application of CFD techniques to greenhouse design and analysis, the numerical results of the CFD model were compared with the results of a steady-state mass and energy balance numerical model. Assuming the results of the mass and energy balance model as the standard, reasonably good agreement was obtained between the natural ventilation rates computed by the CFD numerical model and the mass and energy balance model. The steady-state CFD model during a sunny day showed negative errors as high as 15% in the morning and comparable positive errors in the afternoon. Such errors assumed to be due to heat storage in the floor, benches, and greenhouse structure. For a west wind of 2.5 m s$^{-1}$ , the internal nonporous shading screens that opened to the east were predicted to have a 15.6% better air exchange rate than opened to the west. It was generally predicted that the presence of nonporous internal shading screens significantly reduced natural ventilation if the horizontal opening of the screen for each span was smaller that the effective roof vent opening.

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대학부속병원 근무 의사들의 한의학에 대한 인식 (Attitude and Recognition of Medical Doctors Who Employed by University Hospital on Traditional Korean Medicine)

  • 이은주;박한솔;이소영;배다정;이탁근;신현규
    • 동의생리병리학회지
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    • 제26권5호
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    • pp.773-777
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    • 2012
  • Since 2010, in general hospital, they can install western medical post, traditional Korean medical post, and dental post. So the environment is made for the Cooperative medical system between traditional Korean medicine(TKM) and western medicine(WM) to be performed. So we found out about how doctors think about TKM and what is needed for TKM & WM cooperative system to work well. When we found out about how recognition changed about TKM during their medical school years and after they became doctors, positive answer increased from 25.6% to 30%, negative answer decreased from 41.9% to 32.0%, severely negative increased from 9.3% to 16%. They changed to positive about TKM after they became doctors. But severely negative also increased. The element they lose faith in TKM is their doubt about the scientific aspects of TKM. On the other hand, severely negative recognition was also raised. 73.8% of respondents thought the most effective treatment of TKM was for myalgia. 33.3% of them answered the chance to encounter TKM was the mass media, indicating its limitation. 60.5% of them considered major reason for negative evaluation of TKM is its non-scientific aspects and only 30.9% said TKM treatment could be recommended to patients at the hospital. Doctors in WM for recognition on TKM is mostly negative and major reason is its non-scientific aspects. As the solution to this problem, scientification of TKM is suggested through research projects. These connections must be resolved to smoothly work interdisciplinary system of TKM and WM.

Cable with discrete negative stiffness device and viscous damper: passive realization and general characteristics

  • Chen, Lin;Sun, Limin;Nagarajaiah, Satish
    • Smart Structures and Systems
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    • 제15권3호
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    • pp.627-643
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    • 2015
  • Negative stiffness, previously emulated by active or semi-active control for cable vibration mitigation, is realized passively using a self-contained highly compressed spring, the negative stiffness device (NSD).The NSD installed in parallel with a viscous damper (VD) in the vicinity of cable anchorage, enables increment of damper deformation during cable vibrations and hence increases the attainable cable damping. Considering the small cable displacement at the damper location, even with the weakening device, the force provided by the NSD-VD assembly is approximately linear. Complex frequency analysis has thus been conducted to evaluate the damping effect of the assembly on the cable; the displacement-dependent negative stiffness is further accounted by numerical analysis, validating the accuracy of the linear approximation for practical ranges of cable and NSD configurations. The NSD is confirmed to be a practical and cost-effective solution to improve the modal damping of a cable provided by an external damper, especially for super-long cables where the damper location is particularly limited. Moreover, mathematically, a linear negative stiffness and viscous damping assembly has proven capability to represent active or semi-active control for simplified cable vibration analysis as reported in the literature, while in these studies only the assembly located near cable anchorage has been addressed. It is of considerable interest to understand the general characteristics of a cable with the assembly relieving the location restriction, since it is quite practical to have an active controller installed at arbitrary location along the cable span such as by hanging an active tuned mass damper. In this paper the cable frequency variations and damping evolutions with respect to the arbitrary assembly location are then evaluated and compared to those of a taut cable with a viscous damper at arbitrary location, and novel frequency shifts are observed. The characterized complex frequencies presented in this paper can be used for preliminary damping effect evaluation of an adaptive passive or semi-active or active device for cable vibration control.

흡수열펌프에서 흡수기의 성능 개선 연구 (A Study on Improvement of Performance of Absorber in Absorption Heat Pump)

  • 민병훈
    • 공업화학
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    • 제19권3호
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    • pp.338-344
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    • 2008
  • 냉 난방 수요에서 일어나는 환경오염의 최소화와 화석연료 소비를 감소시키기 위해서 에너지보존을 개선시키는 것은 필수적이다. 이러한 점에서 흡수식 열펌프기술은 에너지 절약을 위해서 많은 가능성을 가지고 있다. 흡수식 열펌프는 에너지를 주입하지 않고 폐열의 이용을 높일 수 있는 방법이다. 흡수식 열펌프는 흡수기에서 흡수된 양의 증가가 매우 중요하기 때문에 흡수기 성능이 매우 중요하다. 본 연구에서는 흡수기의 성능을 개선시키기 위해서 메탄올과 글리세린을 작동유체로 하는 내벽에 나선형관을 설치하여 액상을 접선방향으로 공급하는 흡수기에 관한 연구를 수행하였다. 이 방법은 액상흐름에서 난류를 일으켜 물질 및 열전달을 증가시킨다. 흡수기의 각 위치에서 온도와 농도를 측정하여 열전달계수와 물질전달계수를 계산하였고 주입부분에서 열 및 물질전달이 향상되었음을 알 수 있었다.

날개전극형 코로나 모터의 기초 회전특성 및 에너지 효율 (Basic Rotation Characteristics and Energy Efficiencies of a Blade-Type Corona Motor)

  • 정재승;문재덕
    • 전기학회논문지
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    • 제59권10호
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    • pp.1862-1868
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    • 2010
  • A corona motor, as one of a powerful cooling means of microelectronic devices, has been employed because of its very simple structure of no coils and no brushes. In this paper, the effect of polarity of applied voltage and the number of blade corona electrodes on the fundamental properties of rotation of the motor was investigated. The I-V and rotation characteristics of the blade corona electrode were significantly different from the different polarities of applied voltages and the blade corona electrode numbers, due to the different space charge effect resulted by the different migration mobility of the positive and negative ions generated near the blade corona electrode tip of the rotor of the motor. The rotation speed of the motor was influenced significantly by the polarity of corona discharge, the number of blades, and mass of rotor. At the same corona current, an effective rotation can be obtained with the positive corona caused by the lower ion mobility. On the other hand, the higher rotation speed can be obtained with the negative corona resulted from its higher corona current. The highest rotation speed and energy efficiency can be obtained with the rotor having 4 blades.

여대생의 골밀도와 영향 요인에 관한 연구 (Bone Mineral Density and Factors Affecting in Female College Students)

  • 조동숙;이정윤
    • 여성건강간호학회지
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    • 제14권4호
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    • pp.297-305
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    • 2008
  • Purpose: This study was performed to assess the relationships among bone mineral density, dietary habits, life styles and anthropometric measurements in young women. Subjects included 229 female college students in Seoul and Kyunggi province. Method: The subjects were asked about dietary habits and life styles using questionnaire. A sampel of 229 young women was assessed anthropometric measurements and bone mineral density on calcaneous using quantitative ultrasound. Result: The percentages of the osteoporosis(T-score<-2.5), osteopenia(-2.5${\leq}$T-score<-1.0), and normal(T-score${\geq}$-1.0) groups were 1.75%, 13.53% and 84.71%, respectively. Weight, soft lean mass, and BMI were positively related with T-score and Z-score. But height was negative related with SOS(Speed of sounds). Conclusion: This study confirmed that one of the most effective ways to minimize bone mineral density less in young women is to maintain an adequate body weight, soft lean mass, and BMI. And the young women were recommended do not one-side eating, daily intakes of milk products, perform daily physical exercise, and do not drink coke or soft drinks for the bone health.

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LC-MS/MS Profiling-Based Secondary Metabolite Screening of Myxococcus xanthus

  • Kim, Ji-Young;Choi, Jung-Nam;Kim, Pil;Sok, Dai-Eun;Nam, Soo-Wan;Lee, Choong-Hwan
    • Journal of Microbiology and Biotechnology
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    • 제19권1호
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    • pp.51-54
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    • 2009
  • Myxobacteria, Gram-negative soil bacteria, are a well-known producer of bioactive secondary metabolites. Therefore, this study presents a methodological approach for the high-throughput screening of secondary metabolites from 4 wild-type Myxococcus xanthus strains. First, electrospray ionization mass spectrometry (ESI-MS) was performed using extracellular crude extracts. As a result, 22 metabolite peaks were detected, and the metabolite profiling was then conducted using the m/z value, retention time, and MS/MS fragmentation pattern analyses. Among the peaks, one unknown compound peak was identified as analogous to the myxalamid A, B, and C series. An analysis of the tandem mass spectrometric fragmentation patterns and HR-MS identified myxalamid K as a new compound derived from M. xanthus. In conclusion, LC-MS/MS-based chemical screening of diverse secondary metabolites would appear to be an effective approach for discovering unknown microbial secondary metabolites.

Acid-Catalyzed Hydrolysis of Hexacyanoferrate (III) to Prussian Blue via Sequential Mechanism

  • Youngjin Jeon
    • 대한화학회지
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    • 제68권3호
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    • pp.139-145
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    • 2024
  • This study aims to elucidate the mechanism involved in the hydrolysis of the hexacyanoferrate(III) complex ion (Fe(CN)63-) and the mechanism leading to the formation of Prussian blue (FeIII4[FeII(CN)6]3·xH2O, PB) in acidic aqueous solutions at moderately elevated temperatures. Hydrolysis constitutes a crucial step in generating PB through the widely used single-source or precursor method. Recent PB syntheses predominantly rely on the single-source method, where hexacyanoferrate(II/III) is the exclusive reactant, as opposed to the co-precipitation method employing bare metal ions and hexacyanometalate ions. Despite the widespread adoption of the single-source method, mechanistic exploration remains largely unexplored and speculative. Utilizing UV-vis spectrophotometry, negative-ion mode liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS), and a devised reaction, this study identifies crucial intermediates, including aqueous Fe2+/3+ ions and hydrocyanic acid (HCN) in the solution. These two intermediates eventually combine to form thermodynamically stable PB. The findings presented in this research significantly contribute to understanding the fundamental mechanism underlying the acid-catalyzed hydrolysis of the hexacyanoferrate(III) complex ion and the subsequent formation of PB, as proposed in the sequential mechanism introduced herein. This finding might contribute to the cost-effective synthesis of PB by incorporating diverse metal ions and potassium cyanide.