• Title/Summary/Keyword: Breakthrough

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Physician's Attitude toward Treating Breakthrough Cancer Pain in Korea

  • Seo, Min Seok;Shim, Jae Yong;Choi, Youn Seon;Kim, Do Yeun;Hwang, In Gyu;Baek, Sun Kyung;Shin, Jin Young;Lee, Juneyoung;Lee, Chang Geol
    • Journal of Hospice and Palliative Care
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    • v.20 no.1
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    • pp.18-25
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    • 2017
  • Purpose: Adequate control of breakthrough pain is essential for patients with cancer. Managing breakthrough pain mainly depends on understanding the concept of breakthrough pain and the proper usage of rescue medication by physicians. This study aims to assess the attitudes and practice patterns of palliative physicians in managing breakthrough pain for patients in Korea. Methods: This study was based on data from the 2014 breakthrough cancer pain survey conducted by the Korean Society for Hospice and Palliative Care. One hundred physicians participated in the online survey. Among total 33 self-reported questionnaires, twelve items were selected in this analysis. Results: Rapid onset of action is the main influencing factor in selecting rescue opioids. Oral oxycodone (65%) and parenteral morphine (27%) are commonly used. A few physicians (3%) prefer to use transmucosal fentanyl. The percentage of physicians prescribing oral oxycodone due to its rapid onset of action is just 21.5%, whereas the percentage of physicians using parenteral morphine is 81.5%. Two thirds of respondents (66%) answered that breakthrough pain is not well controlled with rescue medications. Conclusion: There is a gap between the needs of physicians in terms of the perceived difficulties of managing breakthrough cancer pain and their practice patterns selecting rescue medications.

Experimental und Numerical Sensitivity Analyses on Push Pull Tracer Tests

  • Hwang, Hyeon-Tae;Lee, Gang-Geun
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2004.09a
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    • pp.312-316
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    • 2004
  • Single-well tracer tests, especially push pull tracer tests, are more effective to estimate hydraulic parameters and microbial metabolic activities in terms of duration and cost compared to multi-well tracer tests. However, there are some drawbacks in accuracy, complicated data analysis and uniqueness. These shortages are thought to be derived from the applied conditions which affect mass recovery curve and breakthrough curve. Factors such as extraction rate, resting period, hydraulic conductivity and hydraulic gradient are considered as the major factors determining the mass recovery rate and shape of the breakthrough curve. The results of the sensitivity analysis are summarized as follows: 1) the significant change in concentration of breakthrough curve is obtained when the extraction rate increases. This effect would also be much higher if the hydraulic conductivity is lower; 2) the mass recovery rate decreases with the increase of resting time, and the difference of mass recovery rates for different resting times is inversely proportional to the hydraulic conductivity; 3) the sensitivity values decrease with time. The hydraulic conductivity affects not only the early period, but the later period of the breakthrough curves; 4) The influence of the hydraulic gradient on the breakthrough curves is greater at earlier stage than at later stage. The mass recovery rate is inversely proportional to the hydraulic gradient.

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Comparable Influencing Factors to evaluate the Phosphate Removal on the Batch and the fix-bed Column by Converter Slag (회분식과 연속흐름 칼럼에서 전로슬래그에 의한 인제거 영향에 미치는 요소에 관한 연구)

  • Lee, Sang-Ho
    • Journal of Korean Society of Water and Wastewater
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    • v.29 no.5
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    • pp.565-573
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    • 2015
  • The influencing factors to remove phosphate were evaluated by converter slag (CS). Experiments were performed by batch tests using different CS sizes and column test. Solutions were prepared at the different pH and concentrations. The maximum removal efficiency was obtained over 98% with the finest particle size, $CS_a$ within 2 hours in batch tests. The removal efficiency was increased in the order of decreasing size with same amount of CS for any pH of solutions. The adsorption data were well fitted to Freundlich isotherm. From the column experiment, the specific factors were revealed that the breakthrough removal capacity (BRC) $x_b/m_{cs}$, was decreased by increasing the influent concentration. The breakthrough time, tb was lasted shorter as increasing the influent concentration. The pH drop simultaneously led to lower BRC drop during the experimental hours. The relation between the breakthrough time and the BRC to influent concentration was shown in the logarithmic decrease. Results suggested that the large surface area of CS possessed a great potential for adsorptive phosphate removal. Consequently particle size and initial concentration played the major influencing factors in phosphate removal by converter slag.

Investigation of Cryogenic Breakthrough Curve Measurement System at 77 K for Hydrogen Isotopologue Separation (수소 동위원소 분리를 위한 77 K 극저온 파과 곡선 측정 시스템 제작)

  • Kim, Suhwan;Oh, Hyunchul
    • Korean Journal of Materials Research
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    • v.32 no.1
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    • pp.36-43
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    • 2022
  • Breakthrough analysis has widely been explored for the dynamic separation of gaseous mixtures in porous materials. In general, breakthrough experiments measure the components of a flowing gas when a gaseous mixture is injected into a column filled with an adsorbent material. In this paper, we report on the design and fabrication of a breakthrough curve measurement device to study the dynamic adsorptive separation of hydrogen isotopologues in porous materials. Using the designed system, an experiment was conducted involving a 1:1 mixture of hydrogen and deuterium passed through a column filled with zeolite 13X (1 g). At room temperature, both hydrogen and deuterium were adsorbed in negligible amounts; however, at a temperature of 77 K, deuterium was preferentially adsorbed over hydrogen. The selectivity was different from that in the existing literature due to the different sample shapes, measurement methods, and column structures, but was at a similar level to that of cryogenic distillation (1.5).

Painful Boney Metastases

  • Smith, Howard S.;Mohsin, Intikhab
    • The Korean Journal of Pain
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    • v.26 no.3
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    • pp.223-241
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    • 2013
  • Boney metastasis may lead to terrible suffering from debilitating pain. The most likely malignancies that spread to bone are prostate, breast, and lung. Painful osseous metastases are typically associated with multiple episodes of breakthrough pain which may occur with activities of daily living, weight bearing, lifting, coughing, and sneezing. Almost half of these breakthrough pain episodes are rapid in onset and short in duration and 44% of episodes are unpredictable. Treatment strategies include: analgesic approaches with "triple opioid therapy", bisphosphonates, chemotherapeutic agents, hormonal therapy, interventional and surgical approaches, steroids, radiation (external beam radiation, radiopharmaceuticals), ablative techniques (radiofrequency ablation, cryoablation), and intrathecal analgesics.

Breakthrough of Single-Quantum Signal in Double-Quantum Filtering and its Elimination

  • Jung, K.J.;Katz, J.;Hilal, S.K.;Cho, Z.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1993 no.05
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    • pp.86-89
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    • 1993
  • Breakthrough of single-quantum coherence is shown to occur even after application of a double-quantum filter with Bax's four-step phase-cycling scheme. The reason for this breakthrough is investigated and a method for its elimination is theoretically developed and experimentally demonstrated.

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Adsorption Behaviors of Cesium and Strontium in Multicomponent System

  • Lee, Hoo-Kun;Park, Geun-Il;Ro, Sung-Gy;Park, Hyun-Soo
    • Proceedings of the Korean Nuclear Society Conference
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    • 1997.05b
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    • pp.274-279
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    • 1997
  • Breakthrough curves for separation of cesium and strontium binary components from aqueous solutions in fixed bed by chabazite and 13X were experimentally obtained and simulated the breakthrough curves for binary component adsorption. It is shown that agreements between model predictions and experimental data are relatively good although some deviations are observed. From engineering point of view, the simple model used here can be applied to simulate adsorption breakthrough curves satisfactorily.

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A simple and rapid approach to modeling chromium breakthrough in fixed bed adsorber

  • Chu, Khim Hoong
    • Advances in environmental research
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    • v.7 no.1
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    • pp.29-37
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    • 2018
  • A simple mathematical model for predicting fixed bed adsorption dynamics is described. The model is characterized by a linear adsorption isotherm and a linear driving force expression for mass transfer. Its analytic solution can be approximated with an algebraic equation in closed form which is easily evaluated by spreadsheet computation. To demonstrate one application of the fixed bed model, a previously published adsorption system is used as a case study in this work. The adsorption system examined here describes chromium breakthrough in a fixed bed adsorber packed with imidazole functionalized adsorbent particles and is characterized by a nonlinear adsorption isotherm. However, the equilibrium behavior of the fixed bed adsorber is in essence governed by a linear adsorption isotherm due to the use of a low influent chromium concentration. It is shown that chromium breakthrough is predicted reasonably well by the fixed bed model. The model's parameters can be easily extracted from independent batch experiments. The proposed modeling approach is very simple and rapid, and only Excel is used for computation.

Breakthrough Characteristics for Lithium Ions Adsorption in Fixed-bed Column Packed with Activated Carbon by Modified with Nitric Acid (질산으로 개질한 활성탄을 충전한 고정층에서 리튬이온 흡착시의 파과특성)

  • Kam, Sang-Kyu;You, Hae-Na;Lee, Min-Gyu
    • Journal of Environmental Science International
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    • v.23 no.6
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    • pp.1143-1149
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    • 2014
  • The adsorption experiments of lithium ions were conducted in the fixed bed column packed with activated carbon modified with nitric acid. Effect of inlet concentration, bed hight and flow rate on the removal of lithium ions was investigated. The experimental results showed that the removal and the adsorption capacity of lithium ions increased with increasing inlet concentration, and decreased with increasing flow rate. When the bed height increased, the removal and the adsorption capacity increased. The breakthrough curves gave a good fit to Bohart-Adams model. Adsorption capacity and breakthrough time calculated from Bohart-Adams model, these results were remarkably consistent with the experimental values. The adsorption capacity was not changed in the case of 3 times repetitive use of adsorbent.

Adsorption Analysis of Benzene Vapor in a Fixed-Bed of Granular Activated Carbon (활성탄 충전층에서 벤젠 증기의 흡착특성)

  • Kim, Seong-Soo;Kim, Jong-Hyun;Park, Sang-Wook
    • Korean Chemical Engineering Research
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    • v.47 no.4
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    • pp.495-500
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    • 2009
  • Activated carbon was used as an adsorbent to capture benzene vapor from gaseous stream of nitrogen in a fixed-bed to obtain the breakthrough data. The deactivation model is used to analyze the adsorption kinetics of benzene vapor using the experimental breakthrough data. The experimental breakthrough data are fitted very well to the deactivation model than the adsorption isotherm models in the literature.