• Title/Summary/Keyword: ablation rate

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Efficacy of ablation and sclerotherapy for the management of ovarian endometrioma: A narrative review

  • Jee, Byung Chul
    • Clinical and Experimental Reproductive Medicine
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    • v.49 no.2
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    • pp.76-86
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    • 2022
  • Ovarian cystectomy is the preferred technique for the surgical management of ovarian endometrioma. However, other techniques such as ablation or sclerotherapy are also commonly used. The aim of this review is to summarize information regarding the efficacy of ablation and sclerotherapy compared to cystectomy in terms of ovarian reserve, the recurrence rate, and the pregnancy rate. Several studies comparing ablation versus cystectomy or sclerotherapy versus cystectomy in terms of the serum anti-Müllerian hormone (AMH) decrement, endometrioma recurrence, or the pregnancy rate were identified and summarized. Both ablation and cystectomy have a negative impact on ovarian reserve, but ablation results in a smaller serum AMH decrement than cystectomy. Nonetheless, the recurrence rate is higher after ablation than after cystectomy. More studies are needed to demonstrate whether the pregnancy rate is different according to whether patients undergo ablation or cystectomy. The evidence remains inconclusive regarding whether sclerotherapy is better than cystectomy in terms of ovarian reserve. The recurrence rates appear to be similar between sclerotherapy and cystectomy. There is not yet concrete evidence that sclerotherapy helps to improve the pregnancy rate via in vitro fertilization in comparison to cystectomy or no sclerotherapy.

Enhancement of Pulsed-Laser Ablation by Phase Explosion of Liquid (액체의 상폭발 과정에 의한 펄스 레이저 용발률의 증진)

  • Kim, Dong-Sik;Lee, Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.25 no.11
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    • pp.1483-1491
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    • 2001
  • Enhancement of pulsed-laser ablation by an artificially deposited liquid film is presented. Measurements of ablation rate, ablation threshold, and surface topography arc performed. Correlation between material ablation and photoacoustic effect is examined by the optical beam deflection method. The dependence of ablation rate on liquid-film thickness and chemical composition is also examined. The results indicate that photomechanical effect in the phase explosion of liquid is responsible for the enhanced ablation. The low critical temperature of liquid induces explosive vaporization with localized photoacoustic excitation in the superheat limit and increases the ablation efficiency. Experiments were carried out utilizing a Q-swiched Nd:YAG laser at near-threshold laser fluences with negligible plasma effect (up to ∼100 MW/cm$^2$).

Ablation rate study using short pulsed laser subjected to Alumina medium (알루미나 세라믹 소재의 초단파 레이저 어블레이션량 연구)

  • Kim, Kyunghan;Park, Jinho
    • Laser Solutions
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    • v.18 no.4
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    • pp.17-22
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    • 2015
  • In this paper, ablation rate of $Al_2O_3$ ceramics by femtosecond laser fluence is derived with experimental method. The automatic three axis linear stage makes laser optics to move with high spatial resolution. With 10 times objective lens, minimal pattern width of $Al_2O_3$ is measured in the focal plane. Ablated surface area is shown as linear tendency increasing number of machining times with various laser power conditions. Machining times is most sensitive condition to control $Al_2O_3$ pattern width. Also, the linear increment of pattern width with laser power change is investigated. In high machining speed, the ablation volume rate is more linear with fluence because pulse overlap is minimized in this condition. Thermal effect to surrounding medium can be minimized and clean laser process without melting zone is possible in high machining speed. Ablation volume rate decelerates as increasing machining times and multiple machining times should be considered to achieve proper ablation width and depth.

Laser application in 3-D micromachining (레이져를 이용한 3차원 형상가공에 관한 연구)

  • 윤경구;이성국;황경현
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.75-78
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    • 1995
  • This paper presents the feasibility of laser ablation process in 3-D micro machining of MEMS (micro Electro Mechanical System)parts. The micro machining characteristics of polymer(Energy fluence, pulse repetition rate, number of pulse, ablation rate)are investigated and 3-D micro machined samples are demonstrated.

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High Dose Therapy of Radioactive Iodine for Thyroid Ablation in Thyroid Carcinoma (갑상선 악성종양에서 갑상선 전절제술 후 방사성 요오드 치료의 효과)

  • Ahn Hee-Cheol;Kang Seong-Joon;Hong In-Soo
    • Korean Journal of Head & Neck Oncology
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    • v.14 no.1
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    • pp.61-69
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    • 1998
  • Objectives: The response rate of the radioactive iodine(RI) therapy with low dose was variable. Only a few studies reported the response and complication rate with high dose. The goal of this study was to access the ablation and complication rate after high dose of RI therapy (more than 100mCi) and to evaluate the factors affect the results. Material and Methods: During a period of 12 years, 225 patients received high dose of RI from 100 to 200mCi depending on the RI uptake in the whole body after total thyroidectomy. 100mCi of RI was given to 123 patients for ablation who showed the uptake only in the thyroid bed. 150mCi was given to another 84 patients for ablation who had uptake confined to the neck. The other 21 patients took more than 200mCi of RI because the whole body scan showed distant metastasis. Among these patients, the ablation and the complication rate was investigated. Results: Elevated level of the serum thyroglobulin(Tg) decreased less than 5ng/ml after RI therapy in all patients except two in the first group. The second group showed reduction of the serum Tg in 93%. Eighteen of the 21 patients in the third group are still alive after RI therapy. There were no fatal complications after high dose RI therapy and most of the complications were minimal and transient. The complication rate was not related with the dose of RI, age, sex, DNA flowcytometry, serum thyroglobulin level and the extent of node dissection. Conclusion: We concluded that RI therapy with high dose was very effective for thyroid ablation after operation and it also showed excellent results with minimal complications for treatment of metastatic lesions.

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Theoretical Analysis on the Optimum Fluence for Copper Ablation with a 515 nm Picosecond Laser (515 nm 피코초 레이저를 이용한 구리 어블레이션 공정의 최적 에너지밀도에 대한 이론적 분석)

  • Shin, Dongsig;Cho, Yongkwon;Sohn, Hyonkee
    • Journal of the Korean Society for Precision Engineering
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    • v.30 no.10
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    • pp.1009-1015
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    • 2013
  • Ultra-short laser pulses are effective, when high requirements concerning accuracy, surface roughness and heat affected zone are demanded for surface structuring. In particular, picosecond laser systems that are suited to be operated in industrial environments are of great interest for many practical applications. This paper focused on inducing optimum process parameters for higher volume ablation rate by analyzing a relationship between crater diameter and optical spot size. In detail, the dependency of the volume ablation rate, penetration depth and threshold fluence on the pulse duration 8 ps and wavelength of 515 nm was discussed. The experimental results showed that wavelength of 515 nm resulted in less threshold fluence ($0.075J/cm^2$) on copper than IR wavelength ($0.3J/cm^2$). As a result, it was possible that optimum fluence for higher volume ablation rate was achieved with $0.28J/cm^2$.

Radiofrequency Ablation for Liver Metastases after Transarterial Chemoembolization: A Systemic Analysis

  • Xu, Chuan;Lv, Peng-Hua;Huang, Xin-En;Wang, Shu-Xiang;Sun, Ling;Wang, Fu-An
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.12
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    • pp.5101-5106
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    • 2015
  • Background: This systemic analysis was conducted to evaluate tumor recurrence rate and one-year survival rate for patients with liver metastases received radiofrequency ablation after transarterial chemoembolization and introduce a new method of radiofrequency ablation by puncture navigation technology for single liver metastases after transarterial chemoembolization. Materials and Methods: Clinical studies evaluating tumor recurrence rate and one-year survival rate. Appling the innova trackvision software to process one liver metastases received transarterial chemoembolization and using radiofrequency ablation by puncture navigation technology to treat the liver metastases. Results: 3 clinical studies which including 235 patients with liver metastases after transaeterial chemoembolization were considered eligible for inclusion. Systemic analysis suggested that tumor recurrence rate was 23% (54/235), one-year survival rate was 76% (178/235). The new procedure was performed successfully and the patient received a good prognosis. Conclusions: This systemic analysis suggests that radiofrequency ablation is a good method for liver metastases after transarterial chemoembolization and could receive a relatively good prognosis.

Excimer Laser Micromachining of Polymers Assisted by Liquid (액체 보조 방식의 Excimer 레이저 폴리머 미세가공)

  • Jang, Deok-Suk;Kim, Dong-Sik
    • Laser Solutions
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    • v.10 no.1
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    • pp.19-27
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    • 2007
  • Previous studies demonstrated that laser ablation under transparent liquid can result in ablation enhancement and particle removal from the surface. Although the ablation enhancement by liquid is already known for semiconductor and metal, the phenomena of polymer ablation have not been studied. In this work, tile liquid-assisted excimer laser ablation process is examined for polymer materials, such as polyethylene terephthalate (PET), polymethyl methacrylate (PMMA) with emphasis on ablation enhancement and surface topography. In the case of PET and PMMA, the effect of liquid is analyzed both for thin water film and bulk water. The results show that application of liquid increases the ablation rate of PMMA while that of PET remains unchanged even in the liquid-assisted process. However, the surface roughness is generally deteriorated in the liquid-assisted process. The surface topography is found to be strongly dependent on the method of liquid application, i.e., thin film or bulk liquid.

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Micro-Processing of Glass Substrates Using a Laser (레이저를 이용한 유리기판의 미세가공(微細加工))

  • Lee, Cheon;Toyoda, Koichi
    • Proceedings of the KIEE Conference
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    • 1994.07b
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    • pp.1425-1427
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    • 1994
  • Laser ablation of glass substrates (8K-7 and synthetic quartz) using a transversely excited atmospheric (TEA) $CO_2$ laser has been inverstigated to obtain high speed etching. The ablation occurs by local heating of a substrate with a focused TEA-$CO_2$ laser beam. The dependence of ablation rate on pulse count and repetition-rate of laser has been discussed.

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Theoretical analysis on the maximum volume ablation rate for copper ablation with a 515nm picosecond laser (515nm 피코초 레이저를 이용한 구리 어블레이션 공정의 최대 가공율에 대한 이론적 분석)

  • Shin, Dongsig;Cho, Yongkwon;Sohn, Hyonkee;Suh, Jeong
    • Laser Solutions
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    • v.16 no.2
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    • pp.1-6
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    • 2013
  • Picosecond lasers are a very effective tool for micromachining metals, especially when high accuracy, high surface roughness and no heat affected zone are required. However, low productivity has been a limit to broadening the spectrum of their industrial applications. Recently it was reported that in the micromachining of copper with a 1064nm picosecond laser, there exist the optimal pulse energy and repetition rate to achieve the maximum volume ablation rate. In this paper, we used a 515nm picosecond laser, which is more efficient for micromachining copper in terms of laser energy absorption, to obtain its optimal pulse energy and repetition rate. Theoretical analysis based on the experimental data on copper ablation showed that using a 515nm picosecond laser instead of a 1064nm picosecond laser is more favorable in that the calculated threshold fluence is 75% lower and optical penetration depth is 50% deeper.

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