• Title/Summary/Keyword: ruled surface

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Initial Clinical Experience with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy in Signet-Ring Cell Gastric Cancer with Peritoneal Metastase

  • Konigsrainer, Ingmar;Horvath, Philipp;Struller, Florian;Konigsrainer, Alfred;Beckert, Stefan
    • Journal of Gastric Cancer
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    • v.14 no.2
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    • pp.117-122
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    • 2014
  • Purpose: Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been shown to improve survival in select patients with gastric cancer and peritoneal metastases. It remains unclear, however, whether this multimodal treatment protocol is also beneficial for signet-ring cell gastric cancer (SRC) patients with peritoneal metastases. Materials and Methods: Clinical data of patients scheduled for upfront systemic chemotherapy consisting of 5-FU (2,600 $mg/m^2$), folinic acid (200 $mg/m^2$), docetaxel (50 $mg/m^2$), and oxaliplatin (85 $mg/m^2$) followed by CRS and HIPEC using cisplatin (50 $mg/m^2$) at the Comprehensive Cancer Center, University Hospital T$\ddot{u}$bingen, Germany were retrospectively analyzed. Results: Eighteen consecutive patients for whom irresectability has been ruled out by a computed tomography scan were enrolled. However, complete cytoreduction could only be achieved in 72% of patients. When categorizing patients with respect to the completeness of cytoreduction, we found no difference between both groups considering tumor- or patient-related factors. The overall complication rate following complete cytoreduction and HIPEC was 46%. Within a median follow-up of 6.6 (0.5~31) months, the median survival for CRS and HIPEC patients was 8.9 months as opposed to 1.1 months for patients where complete cytoreduction could not be achieved. Following complete cytoreduction and HIPEC, progression-free survival was 6.2 months. Conclusions: In SRC with peritoneal metastases, the prognosis appears to remain poor irrespective of complete CRS and HIPEC. Moreover, complete cytoreduction could not be achieved in a considerable percentage of patients. In SRC, CRS and HIPEC should be restricted to highly selective patients in order to avoid exploratory laparotomy.

Sorption Studies of $Cd^{2+}$ on Calcite: Kinetics and Reversibility (방해석의 $Cd^{2+}$ 흡착현상에 대한 연구)

  • Yoon, Hyeon;Reeder, Richard J.
    • Journal of the Mineralogical Society of Korea
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    • v.15 no.2
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    • pp.104-113
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    • 2002
  • The sorption of Cd$^{2+}$ on calcite was studied in aqueous solutions of several electrolytes. The Cd$^{2+}$ concentration, 10$^{-8}$ M, was kept well below saturation with respect to CdCO$_3$(s). Sorption behavior of Cd$^{2+}$ in different ionic strengths of NaClO$_4$solutions shows that sorption is independent of ionic strength. This result suggests that Cd$^{2+}$ sorption on calcite surface is of a specific nature, and adsorption is controlled by an inner-sphere type of surface complex. Two stages in the sorption behavior could be identified: an initial rapid uptake, followed by slower uptake reaching a maximum steady state by 145 hrs. No evidence was observed for surface precipitation, although it can not be entirely ruled out. Desorption of Cd$^{2+}$ from the calcite surface after resuspension into Cd-free solution is initially very rapid, but depends partly on the previous sorption history. Desorption behavior of Cd$^{2+}$ show that an initial rapid desorption followed either by slow uptake reaching a maximum, as in the adsorption experiments, or slowing desorption to reach a steady state minimum. This irreversible behavior of Cd$^{2+}$ sorption and desorption may act as one of the controls for regulating the mobility of dissolved Cd$^{2+}$ natural aqueous systems. Calculated adsorption partition coefficients suggest that overall sorption and desorption process in the concentration range are controlled by d single mechanism.ingle mechanism.

Effects of SITS on Sodium Transport, Oxygen Consumption and Na-K-ATPase of the Frog Skin (개구리 피부의 Sodium 이동, 산소 소모량 및 Na-K-ATPase에 대한 SITS의 영향)

  • Lee, Seung-Mook;An, Mi-Ra;Lee, Syng-Ill;Park, Yang-Saeng
    • The Korean Journal of Physiology
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    • v.17 no.1
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    • pp.55-61
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    • 1983
  • Effects of SITS (4-acetamido-4'-isothiocyano-2, 2'-disulfonic stilbene) on a $Na^+$ transport, tissue oxygen consumption and Na-K-ATPase activity were studied in isolated frog skin preparations. $Na^+$ transport was estimated by measuring the short-circuit current(SC) across the skin; oxygen consumption was measured in separated epidermis as well as in intact skin; and Na-K-ATPase was assayed in $24,000{\times}g$ fraction of epidermal homogenates. The SCC across the skin Was rapidly and substantially reduced in the presence of 10 mM SITS in the medium bathing the outside(mucosal) surface of the skin. When the drug was added to the inside(serosal) bathing medium, there was about 20 min delay for inhibition of SCC and the effect was less pronounced. The above effect of SITS was independent of the presence of $Cl^-$ in the bathing medium. The oxygen consumption of the skin tissue was not affected by SITS, but the Na-K-ATPase activity of a subcellular fraction of the skin was significantly inhibited. These results suggest that SITS retards $Na^+$ transport across the frog skin primarily by interfering $Na^+$ entry across the mucosal membrance of the epithelial cell, although an effect on $Na^+$ pump can not be ruled out completely.

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GPU-only Terrain Rendering for Walk-through (Walk-through를 지원하는 GPU 기반 지형렌더링)

  • Park, Sun-Yong;Oh, Kyoung-Su;Cho, Sung-Hyun
    • Journal of Korea Game Society
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    • v.7 no.4
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    • pp.71-80
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    • 2007
  • In this paper, we introduce an efficient GPU-based real-time rendering technique applicable to every kind of game. Our method, without an extra geometry, can represent terrain just with a height map. It makes it possible to freely go around in the air or on the surface, so we can directly apply it to any computer games as well as a virtual reality. Since our method is not based on any geometrical structure, it doesn't need special LOD policy and the precision of geometrical representation and visual quality absolutely depend on the resolution of height map and color map. Moreover, GPU-only technique allows the general CPU to be dedicated to more general work, and as a result, enhances the overall performance of the computer. To date, there have been many researches related to the terrain representation, but most of them rely on CPU or confmed its applications to flight simulation, Improving existing displacement mapping techniques and applying it to our terrain rendering, we completely ruled out the problems, such as cracking, poping etc, which cause in polygon-based techniques, The most important contributions are to efficiently deal with arbitrary LOS(Line Of Sight) and dramatically improve visual quality during walk-through by reconstructing a height field with curved patches. We suggest a simple and useful method for calculating ray-patch intersections. We implemented all these on GPU 100%, and got tens to hundreds of framerates with height maps a variety of resolutions$(256{\times}256\;to\;4096{\times}4096)$.

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Sorption Behavior of $^{241}Am,\;^{152}Eu,\;^{160}Tb\;and\;^{60}Co$ in the Geological Materials: Eu as an Optimum Analogue for Fate and Transport of Am Behavior in Subsurface Environment (지질매체내에서의 $^{241}Am,\;^{152}Eu,\;^{160}Tb,\;^{60}Co$의 흡착특성비교: 지표지질내에서의 Am의 거동특성을 위한 최적 유사체로서의 Eu)

  • Lee, Seung-Gu;Lee, Kil-Yong;Cho, Soo-Young;Yoon, Yoon-Yeol;Kim, Yong-Je
    • Economic and Environmental Geology
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    • v.40 no.4
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    • pp.361-374
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    • 2007
  • Rare earth elements(REEs) have been used as an useful tool in understanding the various geological processes such as evolution and differentiation in the crust. The REEs also have been used as an analog of actinides for radioactive wastes at the water-rock interactions. Using physicochemical properties of the REEs and actinides, we have shown that Eu is an optimum analogue for understanding the behavior of Am in subsurface environments. Factors affecting sorption behavior of radioactive nuclides in groundwater were investigated by batch experiments. Four nuclides such as $^{241}Am,\;^{152}Eu,\;^{160}Tb\;and\;^{60}Co$ were selected to test our hypothesis, and $^{160}Tb$ and $^{60}Co$ were specifically used to compare to the sorption behavior between $^{241}Am-^{152}Eu$ and other radioactive nuclides. Four different rock samples and one groundwater were used in the batch experiments where solution pH for all experiments was fixed at 5.5. Our results demonstrate that $^{241}Am,\;^{152}Eu,\;and\;^{160}Tb$ show similar sorption behavior whereas $^{60}Co$ is different in sorption behavior at the mineral-water interface, suggesting that the sorption behavior of $^{60}Co$ is affected by different rock types. Our results also show that 1) Eu in REEs is optimum analogue of fate and transport of Am in subsurface environments, and 2) mineral compositions such as $SiO_2,\;TiO_2,\;P_2O_5$ and distribution of REEs such as Eu anomaly play key roles in affecting sorption behavior of radioactive nuclides even though physicochemical properties of geological materials such as specific surface area and cation exchange capacity can not be ruled out.