• 제목/요약/키워드: Refractory materials

검색결과 172건 처리시간 0.021초

Efficacy of 694-nm Fractional Toning Ruby Laser in the Treatment of Malar Melasma

  • Kim, Jun Hyun;Park, Eun Soo;Nam, Seung Min;Cha, Han Gyu
    • Medical Lasers
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    • 제10권1호
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    • pp.45-48
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    • 2021
  • Background and Objectives Among the numerous available therapies, the usefulness of laser treatment has been proven in melasma, especially for refractory to topical agents or chemical peels. This study evaluated the effectiveness of 694-nm wavelength fractional toning ruby laser in melasma presenting on the malar area. Materials and Methods This was a retrospective study of 40 melasma patients treated with 694-nm wavelength ruby fractional toning laser for a total of 8 cycles at intervals of 2 to 3 weeks. Two independent investigators assessed the photographic findings and evaluated the severity of melasma by applying the Melasma Severity Scale (MSS). Subject satisfaction score was also surveyed at every visit. Results After the 4th treatment, subjects were continuously satisfied with their results. At the 8th visit and 1-month after the last treatment, MSS was determined to be significantly improved as compared to the first visit. One case of minor hypopigmentation was reported, but was resolved after one month. Conclusion Application of 694-nm wavelength fractional toning ruby laser for treating melasma on the malar area showed significant improvement in the MSS. Moreover, the treatment could be repeatedly applied, with low complication rate and significant patient satisfaction.

Treatment Outcomes of Gemcitabine in Refractory or Recurrent Epithelial Ovarian Cancer Patients

  • Chanpanitkitchot, Saranya;Tangjitgamol, Siriwan;Khunnarong, Jakkapan;Thavaramara, Thaowalai;Pataradool, Kamol;Srijaipracharoen, Sunamchok
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권13호
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    • pp.5215-5221
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    • 2014
  • Background: To study the response rate (RR), progression-free survival (PFS) and toxicity profiles of recurrent epithelial ovarian cancer (EOC) patients treated with gemcitabine. Materials and Methods: Recurrent EOC patients who were treated with gemcitabine between January 2000 and December 2013 at the Department of Obstetrics and Gynecology, Faculty of Medicine Vajira Hospital were identified and medical records were reviewed. Clinico-pathological features including data of gemcitabine treatment, response and toxicity were collected. Results: We identified 43 EOC patients who had gemcitabine treatment. All except one patient who did not receive any adjuvant treatment, had received platinum-based chemotherapy. Among these 42 patients, 31.0% had refractory cancer to first-line chemotherapy while 69.0% had recurrence with 48.8% being platinum-sensitive. The total cycles of gemcitabine used were 203 (median 4, range 2-9 cycles). Overall RR was 11.6%: 19% in platinum-sensitive vs 4.5% in platinum-resistant groups (p=0.158) and 42.9% in the patients having gemcitabine together with platinum vs 5.6% using gemcitabine alone (P=0.024). Median PFS was 3.6 months (95% confidence interval [CI], 2.73-4.49 months): 8.1 months (95% CI, 2.73-4.49 months) in combination regimen vs 3.2 months (95% CI, 2.01-4.42 months) in single regimen (p=0.077) and 8.1 months (95% CI, 4.73-11.48 months) with the gemcitabine combination vs 2.7 months (95% CI, 1.98-3.38 months) by single gemcitabine in platinum sensitive patients (P=0.007). Common toxicities were hematologic which were well tolerated and manageable. Conclusions: Gemcitabine has modest activity in pre-treated EOC. A combination regimen had higher activity than single agent in platinum sensitive patients with a significant improvement in RR and PFS.

초임계수 산화공정에서 Ethylenediaminetetraacetic Acid (EDTA) 분해 최적화 연구 (Optimal Condition for Decomposition of Ethylenediaminetetraacetic Acid (EDTA) in Supercritical Water Oxidation)

  • 이현철;인정현;김종화;이창하
    • Korean Chemical Engineering Research
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    • 제43권2호
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    • pp.318-323
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    • 2005
  • 초임계수 산화는 난분해성 유기화합물의 분해를 위한 공정으로 각광받고 있다. 본 연구에서는 연속반응기에서 온도 $387-500^{\circ}C$, 압력 250 bar의 초임계수 조건하에서(EDTA 분해효율) 체류시간 15.9-88.9초의 범위의 EDTA 분해효율을 측정하였다. 이때 산화제로는 과산화수소($H_2O_2$)를 사용하였다. EDTA의 분해효율은 온도 및 산화제투입량의 증가에 따라 상승하였으며, 반응물 도입유속의 감소 즉, 체류시간의 증가에 따라서 상승하였다. 본 연구결과 온도 $500^{\circ}C$, 압력 250 bar, 산화제 투입량 400%의 조건에서 최대 99.6%의 분해효율을 나타내었다. 분해효율에 미치는 온도의 영향이 산화제 투입량 증가의 영향보다 컸으며, 5,000 mg/L의 EDTA($COD_{Cr}$로서 3,063 mg/L)의 99% 이상 분해효율은 온도 $500^{\circ}C$와 압력 250 bar의 초임계수 산화조건에서 산화제투입량 200% 이상 및 체류시간 40.1초 이상에서 얻을 수 있었다.

고급강 제조 반응 모델의 검토 : Part. 2. 종합 모델 및 단일 반응 모델 (A Review of Kinetic Model for Production of Highgrade Steel : Part. 2. Complex Reaction Model and Single Reaction Model)

  • 김정인;김선중
    • 자원리싸이클링
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    • 제30권1호
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    • pp.14-25
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    • 2021
  • 고품질 철강의 수요가 증가함에 따라 2차 정련 공정의 중요성이 높아지고 있다. 하지만 공정 시간에 따라 변화하는 용강, 슬래그 및 비금속 개재물의 조성은 정련 공정이 평형 상태가 아님을 의미하며, 정련 공정에서는 용강, 슬래그, 비금속 개재물, 내화물 및 합금 원소 간의 동시 다발적 반응이 일어난다. 다양한 상들의 비평형 상태에서 복잡한 반응을 고려하기 위해, 이전 연구자들은 실험을 통해 도출된 반응 속도 수식들을 기반으로 kinetic 기반의 고급강 제조 정련 시뮬레이션 모델을 발표하였다. 정밀한 시뮬레이션 모델의 개발을 위해 보고된 2차 정련 모델들의 분석 및 검토가 필요하다. 본 연구에서는 국내외로 발표된 정련 공정 관련 종합 모델들 및 단일 반응 모델들에 대하여 검토하고 소개하였다.

불응성 주관절 외상과염에 대한 혈소판 풍부 혈장 주입 치료의 임상적 결과 (Treatment of Refractory Lateral Epicondylitis with Platelet-Rich Plasma)

  • 고상훈;이채칠;강병성;이기재;이선호
    • Clinics in Shoulder and Elbow
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    • 제13권1호
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    • pp.58-63
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    • 2010
  • 목적: 주관절 외상과염은 주관절 동통을 유발하는 대표적인 질환 중 하나로 이에 대한 치료 방법은 여러 문헌에서 보고 된 바 있다. 본원에서는 외상과염에 대한 혈소판 풍부 혈장 (Platelet-Rich-Plsma) 주입 치료를 시행한 후 그 임상적 결과를 평가해 보고자 하였다. 대상 및 방법: 2009년 1월부터 2009년 12월까지 본원에서 외상과염으로 진단받은 환자 15명 (남자 5명, 여자 10명)을 대상으로 하였으며, 평균 연령은 43.5세 였다. 모든 환자는 타 병원에서 1년 이상의 물리치료, 약물치료 등의 보존적 치료를 시행 받았으나, 증상호전을 보이지 않아 수술적 치료를 고려하는 환자였다. 대상 환자는 주관절 외상과에 경피적 혈소판 풍부 혈장 농축액 3cc를 1회 주입하였으며, 치료효과의 판정은 휴식 시와 작업 시의 visual analogue scale (VAS), The Patient-Rated Tennis Elbow Evaluation (PRTEE)를 시술 후 4, 12주 후 측정하고 치료 전후를 비교평가 하였다. 결과: 치료 4주, 12주 단기 추시에서 휴식시 통증의 VAS 평균 값은 치료 전 4.6에서 치료 4주째 2.5 12주째 1.8로 개선 되었고, 작업시 통증의 경우 치료 전 7.8에서 치료 4주째 6.2 치료 12주째 4.25로 개선 되었다. PRTEE score 평균 값은 치료 전 60.13에서 치료 4주째 46.12, 12주째 24.6으로 개선 되었다. 결론: 보존적 치료에 반응을 보이지 않는 불응성 주관절 외상과염의 치료에 있어 혈소판 풍부 혈장 주입을 이용한 치료는 효과적인 치료법이며, 수술적 치료를 시행 전 고려 되어야 한다고 사료 된다.

기존의 치료에 반응하지 않는 다발성 간전이 대장암 환자에서 방사선조사와 병합한 수지상세포 면역치료의 1, 2상 임상시험 (A Phase I/II Trial of $DCVac/IR^{(R)}$ Dendritic Cell Immunotherapy Combined with Irradiation in Cases of Refractory Colorectal Cancer with Multiple Liver Metastases)

  • 최영민;이형식;권혁찬;한상영;최종철;정주섭;김창원;김동원;강치덕
    • Radiation Oncology Journal
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    • 제26권2호
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    • pp.104-112
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    • 2008
  • 목적: 기존치료에 반응하지 않는 다발성 간전이를 동반한 대장암 환자에서 방사선치료와 병합한 수지상세포 면역치료의 독성과 반응도를 조사하였다. 대상 및 방법: 2004년 5월부터 2006년 11월까지 다발성 간전이가 동반된 대장암 환자들 중에서 항암화학 요법에 반응하지 않은 환자 중 지원자를 대상으로 연구를 시행하였다. 본 임상 시험에 대하여 동아대학교병원과 부산대학교병원의 임상윤리심의위원회의 허가를 획득하였고, 동의서에 서명한 환자들을 임상 시험의 대상으로 등록하였다. 환자의 말초 혈액으로부터 수지상세포를 추출하여 배양하였다. 임상시험 일자에 맞추어서 $6{\times}10^6$개의 수지상세포를 바이알(0.5 ml)에 넣어서 디씨백/아이알 주사를 만들었다. 수지상세포 면역치료는 2주 간격으로 간전이암조직에 3회 주사하고, 5주에 내약성 평가를 하였다. 내약성 평가를 통과한 환자에게는 8주에 4번째 수지상세포 면역치료를 하였다. 병의 악화가 없거나 임상시험에 대한 환자의 동의 철회가 없는 경우에는 5, 6번째 수지상세포 면역치료를 각각 12, 16주에 시행하였다. 방사선치료는 수지상세포 면역치료를 주사할 간전이암 부위에 주사하기 전일 및 당일에 4 Gy씩을 조사하였다. 내약성 평가는 $3{\times}10^6$개의 수지상세포로부터 시작하여, $12{\times}10^6$개의 수지상세포까지 시행하였다. 내약성 평가의 최대 내성 용량으로 추가 임상시험을 하였다. 수지상세포 면역치료 주사를 맞은 모든 환자들에서 안전성 평가를 하였다. 4회 이상 주사를 맞은 환자들을 대상으로 10주에 치료 반응을 평가하여 유효성을 조사하였다. 결과: 임상시험에 등록한 24명 중 22명에서 수지상세포 면역치료를 시행하였다. 내성약 평가에는 14명이 등록하여 11명에서 평가를 완료하였다. 시험약과의 관련성이 있을 것으로 생각되는 grade 3 이상의 약물반응으로 인한 이상반응은 없었다. $12{\times}10^6$개의 수지상세포를 내성용량으로 확인하였고, 내성용량인 $12{\times}10^6$개 수지상세포 면역치료를 이용하여 8명에서 추가로 시험을 하였다. 치료에 대한 환자들의 내성은 양호하였고, grade 3을 초과하는 치명적인 부작용은 발생되지 않았다. 4회 이상의 수지상세포 면역치료 주사를 받은 환자가 17명이었고, 이 중의 15명에서는 종양의 반응도 평가가 이루어졌다. 본 연구의 목적은 안전성 평가이지만, 면역치료의 유효성 평가를 위해, 방사선치료와 수지상세포 면역치료 주사가 시행된 부위 외의 간전이암에서 반응도를 조사 하였다. 면역치료의 반응은 평가가 이루어진 환자들에서 정지성 병변이 4명, 진행성 병변이 11명 이었다. 결론: 수지상세포 면역치료와 병행한 방사선치료는 이론적으로 국소 및 전신 제어에 상승효과가 있을 것으로 기대할 수 있다. 하지만 기존 치료에 반응하지 않는 매우 진행된 직장암 환자들을 대상으로 한 본 연구에서는 방사선 치료와 병합한 수지상세포 면역치료로 인한 심각한 부작용의 발생은 없었다는 결과와 4예에서의 정지성 병변의 관찰을 보고한다. 수지상세포의 최대 투여 용량, 적절한 투여 방법, 적절한 방사선의 양, 방사선과 수지상 세포의 적절한 투여 간격 등에 관한 추가 연구를 통하여, 향후 제 2상, 3상 시험으로서의 진행 여부에 긍정적인 결과를 얻을 수 있다고 판단한다.

Application of Gamma Ray Densitometry in Powder Metallurgy

  • Schileper, Georg
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2002년도 제3회 최신 분말제품 응용기술 Workshop
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    • pp.25-37
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    • 2002
  • The most important industrial application of gamma radiation in characterizing green compacts is the determination of the density. Examples are given where this method is applied in manufacturing technical components in powder metallurgy. The requirements imposed by modern quality management systems and operation by the workforce in industrial production are described. The accuracy of measurement achieved with this method is demonstrated and a comparison is given with other test methods to measure the density. The advantages and limitations of gamma ray densitometry are outlined. The gamma ray densitometer measures the attenuation of gamma radiation penetrating the test parts (Fig. 1). As the capability of compacts to absorb this type of radiation depends on their density, the attenuation of gamma radiation can serve as a measure of the density. The volume of the part being tested is defined by the size of the aperture screeniing out the radiation. It is a channel with the cross section of the aperture whose length is the height of the test part. The intensity of the radiation identified by the detector is the quantity used to determine the material density. Gamma ray densitometry can equally be performed on green compacts as well as on sintered components. Neither special preparation of test parts nor skilled personnel is required to perform the measurement; neither liquids nor other harmful substances are involved. When parts are exhibiting local density variations, which is normally the case in powder compaction, sectional densities can be determined in different parts of the sample without cutting it into pieces. The test is non-destructive, i.e. the parts can still be used after the measurement and do not have to be scrapped. The measurement is controlled by a special PC based software. All results are available for further processing by in-house quality documentation and supervision of measurements. Tool setting for multi-level components can be much improved by using this test method. When a densitometer is installed on the press shop floor, it can be operated by the tool setter himself. Then he can return to the press and immediately implement the corrections. Transfer of sample parts to the lab for density testing can be eliminated and results for the correction of tool settings are more readily available. This helps to reduce the time required for tool setting and clearly improves the productivity of powder presses. The range of materials where this method can be successfully applied covers almost the entire periodic system of the elements. It reaches from the light elements such as graphite via light metals (AI, Mg, Li, Ti) and their alloys, ceramics ($AI_20_3$, SiC, Si_3N_4, $Zr0_2$, ...), magnetic materials (hard and soft ferrites, AlNiCo, Nd-Fe-B, ...), metals including iron and alloy steels, Cu, Ni and Co based alloys to refractory and heavy metals (W, Mo, ...) as well as hardmetals. The gamma radiation required for the measurement is generated by radioactive sources which are produced by nuclear technology. These nuclear materials are safely encapsulated in stainless steel capsules so that no radioactive material can escape from the protective shielding container. The gamma ray densitometer is subject to the strict regulations for the use of radioactive materials. The radiation shield is so effective that there is no elevation of the natural radiation level outside the instrument. Personal dosimetry by the operating personnel is not required. Even in case of malfunction, loss of power and incorrect operation, the escape of gamma radiation from the instrument is positively prevented.

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CERAMIC INLAY RESTORATIONS OF POSTERIOR TEETH

  • Jin, Myung-Uk;Park, Jeong-Won;Kim, Sung-Kyo
    • 대한치과보존학회:학술대회논문집
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    • 대한치과보존학회 2001년도 춘계학술대회
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    • pp.235-237
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    • 2001
  • ;Dentistry has benefited from tremendous advances in technology with the introduction of new techniques and materials, and patients are aware that esthetic approaches in dentistry can change one's appearance. Increasingly. tooth-colored restorative materials have been used for restoration of posterior teeth. Tooth-colored restoration for posterior teeth can be divided into three categories: 1) the direct techniques that can be made in a single appointment and are an intraoral procedure utilizing composites: 2) the semidirect techniques that require both an intraoral and an extraoral procedure and are luted chairside utilizing composites: and 3) the indirect techniques that require several appointments and the expertise of a dental technician working with either composites or ceramics. But, resin restoration has inherent drawbacks of microleakage. polymerization shrinkage, thermal cycling problems. and wear in stress-bearing areas. On the other hand, Ceramic restorations have many advantages over resin restorations. Ceramic inlays are reported to have less leakage than resin restoration and to fit better. although marginal fidelity depends on technique and is laboratory dependent. Adhesion of luting resin is more reliable and durable to etched ceramic material than to treated resin composite. In view of color matching, periodontal health. resistance to abrasion, ceramic restoration is superior to resin restorationl. Materials which have been used for the fabrication of ceramic restorations are various. Conventional powder slurry ceramics are also available. Castable ceramics are produced by centrifugal casting of heat-treated glass ceramics. and machinable ceramics are feldspathic porcelains or cast glass ceramics which are milled using a CAD/CAM apparatus to produce inlays (for example, Cered. They may also be copy milled using the Celay apparatus. Pressable ceramics are produced from feldspathic porcelain which is supplied in ingot form and heated and moulded under pressure to produce a restoration. Infiltrated ceramics are another class of material which are available for use as ceramic inlays. An example is $In-Ceram^{\circledR}$(Vident. California, USA) which consists of a porous aluminum oxide or spinell core infiltrated with glass and subsequently veneered with feldspathic porcelain. In the 1980s. the development of compatible refractory materials made fabrication easier. and the development of adhesive resin cements greatly improved clinical success rates. This case report presents esthetic ceramic inlays for posterior teeth.teeth.

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분광색채계측기를 이용한 Vita Shade 광중합형 복합레진의 색상 비교 (COMPARATIVE EVALUATION OF LIGHT-CURED COMPOSITE RESINS BASED ON VITA SHADE BY SPECTROCOLORIMETER)

  • 조경이;황인남;최홍란;오원만
    • Restorative Dentistry and Endodontics
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    • 제23권1호
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    • pp.424-432
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    • 1998
  • To get a satisfactory result in the composite resin restorations, it is necessary to choose correct shade. At present, most of the commercial composite resins are based on the Vita Lumin shade guide or Bioform shade guide, but color differences might be expected even using the same shade in various materials. In this study, five kinds of light-cured composite resins with A2 and B3 shade were used to measure and compare the color each other while one porcelain served as a control. All composite resins (Spectrum TPH (SP), VeridonFil- Photo (VE), Z100 (Z100), Charisma (CH), Prodigy (PRO)) were filled in to the metal mold (12 mm diameter, 2 mm depth), followed by compression, polymerization and polishing with wet sandpaper. The specimens of porcelain were fabricated by using the refractory mold for porcelain. After 24 hours, the specimens were placed on the spectrocolorimeter and spectral reflectance were measured under CIE illuminant D65. After measuring the values of $L^*$, $a^*$, $b^*$ and ${\Delta}E^*$, following results were obtained; 1. The $L^*$, $a^*$ and $b^*$ values of both shade of porcelain specimens showed significantly higher than those of resin specimens(p<0.05). 2. In comparing the resin specimens of the A2 shade, differences were significant except $L^*$ values of SP-CH and PRO-VE, $a^*$ values of the VE-SP and $b^*$ values of the VE-Z100 and SP-PRO(p<0.05), 3. In comparing the resin specimens of the B3 shade, differences were significant except $L^*$ values of PRO-SP, $a^*$ values of the SP-PRO and Z100-VE and b* values of the PRO-SP(p<0.05). 4. In comparing the resin specimens of the A2 shade, color differences between materials (${\Delta}E^*$) showed the lowest value of 1.66, and the highest was 5.16. ${\Delta}E^*$ values of the materials of VE-PRO, CH-PRO, SP-PRO, SP-Z100 and SP-CH were lower than 3.3. 5. In comparing the resin specimens of the B3 shade, the lowest value of the ${\Delta}E^*$ was 0.57 and the highest was 5.92. ${\Delta}E^*$ values of Z100-CH and SP-PRO were lower than 3.3. The present study revealed there was perceptible color difference between materials even if they have the same designated shade based on Vita shade guide. The results of the present study suggested that it would be necessary to establish the reproducible and constant color specification system for an esthetic restoration.

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필발(Piper longum Linn.)로부터 전립선암 세포사멸물질 pipernonaline의 분리 및 동정 (Purification and Identification of Apoptosis Modulator Pipernonaline from Piper longum Linn. against Prostate Cancer Cells)

  • 김광연;김윤진;이완;유선녕;조효진;이선이;이한승;손재학;오현철;안순철
    • 생명과학회지
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    • 제19권5호
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    • pp.671-675
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    • 2009
  • Prostate cancer has been a critical health problem due to an increase of prostate cancer-related deaths worldwide. Also, a frequent treatment option for prostate cancer is androgen ablation, but this treatment has a limited scope, especially for hormone-refractory cancer. There is an urgent need for the identification of alternative therapeutic strategies for prostate cancer. Previously, over one hundred species of dried-plant methanol extracts were tested for inhibitory effects on proliferation. One of them, Piper longum Linn. was selected based on its potent anti-proliferation effect. The dried root of P. longum Linn. was extracted with 100% methanol for 2-3 days and its extract was fractionated using chloroform. The chloroform layer was then subjected to column chromatography on silica gel, reverse phase-18 (RP-18) and Sephadex LH-20, in turn. Finally, the pure compound was obtained and identified as pipernonaline by NMR spectroscopic and physico-chemical analysis. In this study, anti-proliferation and cell cycle arrest effects of pipernonaline on human prostate cancer PC-3 cells were investigated using the MTT and PI staining, respectively. Our findings suggest that pipernonaline represents a dose-dependent growth inhibition pattern on PC-3 cells and, moreover, its growth inhibition is associated with sub-G1 and G0/G1 cell cycle accumulation in PC-3 cells. Also, these results provide an anticancer candidate for human prostate cancer.