• 제목/요약/키워드: WATER STRESS

검색결과 3,227건 처리시간 0.03초

극경암에서의 전단면터널 굴착속도 분석연구 (Analysis on the TBM Penetration Rates in Extremely Hard Rocks)

  • 박철환;신중호;박찬;김민규;정소걸;김화수
    • 터널과지하공간
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    • 제10권4호
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    • pp.526-532
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    • 2000
  • 전단면터널 굴착장비에 의한 터널굴착을 설계할 때 일반적으로 적용되는 암반의 강도는 80-250 MPa로 알려져 있으나 설계단계에서 암반의 특성을 완전히 파악하지 못한 채 설계하고 수행하는 경우가 있다. 본 연구는 60% 이상 구간의 단축압축강도가 260 MPa이상이며, RMR값이 70이상의 암반에서 TBM으로 굴착된 약 5.3km 연장의 밀양댐계통 광역상수도 도수로터널 TBM 굴착구간의 암반특성을 규명하고 이로써 이론적 굴착속도를 분석하여, 실제의 순굴착속도와 비교분석한 것이다. 노르웨이 NTH에 의하여 제안된 이론적 굴착속도는 현장에서 수행된 순굴착속도의 평균값과 2∼20%의 오차를 갖는 것으로 평가되어, 극경암에서의 굴착속도 설계는 일본이나 미국에서 제안된 해석법에 비하여 NTH해석법이 가장 접근된 설계방법이라 할 수 있다. 현지암반을 펑가하여 순굴착속도와의 상관관계를 규명한 결과, 극경암에서의 순굴착속도는 슈미트 해머에 의한 반발경도와 RMR 값에 반비례하는 것으로 나타났는데, 이의 상관계수는 각각 0.705 및 0.777이었다. 이로써 반발경도와 RMR의 크기는 순굴착속도를 예측할 수 있는 요소가 될 수 있음을 알 수 있다. 또한 극경암에서의 순굴착속도는 현지암반의 지압의 크기에 크게 영향을 받고 있는 것으로 평가되어 TBM 굴착설계에서 지압상태는 중요한 설계요소의 하나로서 고려되어야 할 것이다.

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암반공학시스템과 수치해석을 이용한 저심도 암반터널에서의 붕락 발생 가능성 평가 (Evaluation of Cave-in Possibility of a Shallow Depth Rock Tunnel by Rock Engineering Systems and Uumerical Analyses)

  • 김만광;유영일;송재준
    • 터널과지하공간
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    • 제19권3호
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    • pp.236-247
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    • 2009
  • 도심지에서의 인구 및 시설물 과밀화 현상으로 인해 지하 공간의 효율적 활용 문제가 대두되고 있으며, 이에 대한 해결책으로 저심도 지하공간의 개발이 증가되고 있다. 그러나 저심도 터널 굴착시 예상치 못한 붕락 문제도 함께 증가하고 있으므로, 터널 붕락으로 인한 인명과 재산의 피해를 줄이기 위해서는 굴착 개시전에 암반거동 유형을 파악하고 분류하는 것이 필요하다. 특히 붕락(cave-in)의 경우 낙반이나 소성변형보다 발생규모가 크고 빠르게 일어나는 특징이 있으므로 이에 대한 대비책이 마련되어야 한다. 본 연구에서는 7가지의 매개변수-일축압축강도, 암질지수, 절리면 상태, 응력 상태, 지하수, 지진 및 진동, 터널 폭을 이용하여 붕락 거동 유형을 파악하고자 하였다. 이러한 매개변수로부터 붕락 거동을 예측하기 위해서는 현장 사례로부터 충분한 자료를 확보하여야하나 현장자료의 부족 등의 현실적인 한계를 고려하여 7가지 매개변수들간의 상호영향성과 가중치를 산정하기위해 전문가 집단의 의견과 암반공학시스템의 원리를 이용하였다. 그 결과로 저심도 암반터널에서의 붕락 거동 지수를 서울 지하철 9호선 000구간에 적용하였다. 한편 288가지 경우의 불연속체 해석을 통해 붕락 발생 유무를 확인하였고 이를 붕락 거동 지수와 비교하였다. 또한 로지스틱 회귀분석을 통해 도출된 회귀식으로 지보패턴별 파괴확률을 산출하였고 이를 붕락 거동 지수와 비교하였다.

PREDICTION OF PHYSICO-CHEMICAL AND TEXTURE CHARACTERISTICS OF BEEF BY NEAR INFRARED TRANSMITTANCE SPECTROSCOPY

  • Olivan, Mamen;Delaroza, Begona;Mocha, Mercedes;Martinez, Maria Jesus
    • 한국근적외분광분석학회:학술대회논문집
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    • 한국근적외분광분석학회 2001년도 NIR-2001
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    • pp.1256-1256
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    • 2001
  • The physico-chemical and texture characteristics of meat determine the nutritional, technological and sensory quality. However, the analysis of meat quality requires expensive, laborious and time consuming analytical methods. The objective of this study was to evaluate NIR spectroscopy using transmittance for determining the moisture, fat, protein and total pigment content, the water holding capacity (WHC) and the toughness of beef meat. A total of 318 spectra were recorded from ground beef samples by a Feed Analyzer 1265 of Infratec. The samples were obtained from the Longissimus muscle of the 10$^{th}$ rib of yearling bulls, ground with an electrical chopper, vacuum packaged, aged during 7 days and frozen at -24$^{\circ}C$ until the analyses were done. Moisture content was measured by oven drying at 10$0^{\circ}C$, fat content was determined by Soxhlet extraction and protein content was estimated from nitrogen content using the Kjeldahl analysis. The total pigment content was determined by the method of Hornsey and the WHC using the method of filter paper press. The instrumental evaluation of texture (maximum load WB, maximum stress MS and toughness) was conducted in an Instron equipment with a Warner-Bratzler shearing device. This analysis was performed on a chop of 3.5 cm obtained from the longissimus of the 8$^{th}$ rib, aged during 7 days, kept frozen at -24$^{\circ}C$ and cooked before the analysis. Near infrared spectra were recorded as log 1/T (T=transmittance) at 2 nm intervals from 850 to 1050 nm using a Feed Analyzer 1265 of Infratec. Calibrations were performed with the WinISI software (vs. 1.02) using the MPLS method. To examine the effect of scatter correction o. derivation of spectra on the calibration performance, calibrations were calculated with the crude spectra or pretreated with different mathematical treatments (inverse MSC, SNVD) and/or second derivative operation. For chemical composition, the use of the scatter corrections improved the calibration statistics, in terms of lower SECV and higher $r^2$. In most of the variables, the use of the 2$^{nd}$ derivative improved the predictions, mainly when combined with the SNVD treatment. However, for predicting the texture traits, the best estimation was obtained from the crude spectrum. These results showed that the equations obtained for predicting moisture, fat and total pigments were very accurate, with $r^2$ being higher that 0.9. However, the prediction of the texture traits (WB, MS, toughness) from ground meat was poor.

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Silorane 복합레진의 중합수축의 동력학 (POLYMERIZATION SHRINKAGE KINETICS OF SILORANE-BASED COMPOSITES)

  • 권영철;이인복
    • Restorative Dentistry and Endodontics
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    • 제35권1호
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    • pp.51-58
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    • 2010
  • 복합레진이 개발된 이후 많은 물성의 향상이 이루어졌으나 복합레진의 중합수축은 아직 해결되지 않은 주요 단점으로 남아있다. 중합수축이 적은 복합레진을 만들기 위한 많은 노력이 이루어졌고, 최근에 기존의 methacrylate 기질이 아닌 silorane 기질의 복합레진이 개발되었다. 본 연구에서는 silorane 기질의 복합레진과 methacrylate 기질의 복합레진의 중합수축거동을 측정하고 비교하고자 하였다. 온도변화에 민감하지 않으며 실시간으로 복합레진의 체적 중합수축을 측정할 수 있는 계측장치를 제작하여 사용하였다. 5종의 methacrylate 기질의 수복용 복합레진(Beautifil, Z100, Z250, Z350, Gradia X)과 silorane 기질 복합레진 (P90)의 중합수축을 10분 동안 측정하여, 중합수축량, 최대 중합수축률 그리고 최대수축시간을 비교하였다. 복합레진의 중합수축은 제품별로 많은 차이를 보였다. Silorane 기질의 P90복합레진의 중합수축이 1.48%로 가장 낮았고 Beautifil 복합레진의 중합수축이 2.80%로 가장 높았다. Methacrylate 계열의 복합레진 사이에도 중합수축량에 제품별로 유의한 차이를 보였다(p<0.05). 최대 중합수축률은 P90이 0.13%/s로 가장 낮았고 Z100이 0.34%/s로 가장 높았다. 최대 수축시간은 methacrylate기질의 복합레진(2.4-3.1초)에 비해, silorane 기질의 P90 복합레진이 6.7초로 두 배 이상 길었다. 최대중합수축률은 중합수축과 최대수축시간의 역수를 곱한 값과 강한 양의 상관관계를 보였다(R = 0.95).

산화적 스트레스로 유도된 간손상에 대한 소음인보중익기탕 열수추출물의 간세포보호효과 (The Protective Activity of Soeumin Bojungykgi-tang Water Extract Against Oxidative Stress-induced Hepato-Toxicity)

  • 손진원;정지윤;김광연;황보민;박정아;조일제;백영두;정태영;김상찬;지선영
    • 대한한의학방제학회지
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    • 제25권4호
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    • pp.509-526
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    • 2017
  • Background and objectives : Soeumin Bojungykgi-tang (seBYTE) has been used to supplement qi in Korean medicine. It has been demonstrated to possess various biological functions such as anti-cancer, anti-aging and anti-inflammatory effects. The present study evaluated the protective roles of seBYTE in hepatotoxic in vitro and in vivo model. Methods : To investigate cytoprotective effect of seBYTE, HepG2 cells were pretreated with seBYTE and then subsequently exposed to $10{\mu}m$ AA for 12 h, followed by $5{\mu}m$ iron. Cell viability was examined by MTT assay, and expression of apoptosis-related proteins was evaluated by immunoblot analysis. For responsible molecular mechanisms, ROS production, GSH contents, and mitochondrial membrane potential were measured. In addition, hepatoprotective effect of seBYTE in vivo was assessed in $CCl_4$-induced animal model. Results : seBYTE prevented AA + iron-induced cytotoxicity in concentration dependent manner. In addition, ROS production, GSH depletion, and mitochondrial dysfunction induced by AA + iron were significantly reduced by seBYTE pretreatment. Furthermore, seBYTE recovered expression of the pro-apoptotic proteins such as PARP and pro-caspase-3. In animal experiment, plasma ALT and AST levels were significantly elevated in $CCl_4$ treatment, but seBYTE significantly decreased the ALT and AST levels. Moreover, seBYTE alleviated the numbers of histological activity index, percentages of degenerative regions, degenerated hepatocytes, infiltrated inflammatory cells, nitrotyrosine- and 4-hydroxynonenal-positive cells in liver. Conclusions : These results showed that hepatoprotective effect of seBYTE against on $CCl_4$-induced hepatic damages is partly due to antioxidative and anti-apoptotic process.

HPLC에 의한 뱀장어 (Anguilla japonica) 혈장중의 acethylsalicylic acid (aspirin)과 salicylic acid의 측정 (Determination of Acethylsalicylic acid (Aspirin) and Salicylic acid in Eel (Anguilla japonica) Plasma by High-performance Liquid Chromatography)

  • 김동완;구재근;박성우
    • 한국어병학회지
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    • 제20권2호
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    • pp.139-145
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    • 2007
  • 인체에 널리 사용되고 있는 Aspirin (ASA)을 양식 뱀장어 (Anguilla japonica) 약욕 또는 경구 투여한 다음 혈장 중의 ASA와 salicylic acid (SA)의 양을 HPLC로 측정하였다. 뱀장어 혈장은 0.2 M HCl과 0.2 M orthophosphoric acid로 산성화시킨 다음 acetonitrile과 혼합하여 ASA와 SA를 추출하였다. 2약제의 정량은 Novapak C18과 UV detector (237 nm)가 장착된 HPLC로 측정하였다. 이 때 이동상은 740 ㎖의 증류수, 900 ㎕의 orthophosphoric acid와 180㎖의 acetonitrile을 사용하였다. ASA, SA 및 내부 표준물질로 사용한 2-methylbenzoic acid (MBA)의 retention time은 각각 4.8분, 8.4분 및 11.4분이였으며, 측정한계 농도는 ASA가 0.05 ㎍/㎖, SA는 0.01 ㎍/㎖였다. 혈장으로 부터의 평균회수율은 ASA가 70.8-99.6%, SA는 95.2-100.3%였다. 뱀장어에 ASA를 약욕 (20 ppm) 또는 경구투여 (50 ㎎/kg BW) 한 다음 채취한 혈장을 시료로 이 방법으로 ASA와 SA의 양을 측정한 결과 단지 SA만 검출되어졌고, ASA는 검출되지 않았다. 이는 ASA가 혈장내에서 신속히 SA로 분해되기 때문으로 판명되었다. 또 ASA에 약욕시킨 경우에는 약욕 후 3시간후에 혈장내의 SA양이 최고치에 도달하였으며, 경구투여 한 경우에는 7일후에 최고치에 도달하였다. 한편 ASA를 투여한 다음 ASA 무첨가 수조에 수용한 결과 2투여 경로 모두 48시간 이후에는 SA가 0.02-0.03 ㎍/㎖이 검출되어 잔류의 문제도 거의 없었다. HPLC를 이용한 혈장내의 ASA와 SA의 검출법은 신속하며 정확한 방법으로 뱀장어 이외의 어류에도 활용 가능할 것으로 생각된다.

Nighttime Cooling Is an Effective Method for Improving Milk Production in Lactating Goats Exposed to Hot and Humid Environment

  • Sunagawa, Katsunori;Nagamine, Itsuki;Kamata, Yasuhiro;Niino, Noriko;Taniyama, Yoshihiko;Kinjo, Kazuhide;Matayoshi, Ayano
    • Asian-Australasian Journal of Animal Sciences
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    • 제28권7호
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    • pp.966-975
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    • 2015
  • Heat production in ruminants follows a diurnal pattern over the course of a day peaking 3 hours following afternoon feeding and then gradually declining to its lowest point prior to morning feeding. In order to clarify the cooling period most effective in reducing decreases in feed intake and milk production, experiments were carried out based on the diurnal rhythm of heat production and heat dissipation. In experiment 1, the effects of hot environment on milk production were investigated. The animals were kept first in a thermoneutral environment ($20.0^{\circ}C$, 80.0%) for 12 days, they were then transitioned to a hot environment ($32^{\circ}C$, 80.0%) for 13 days before being returned to second thermoneutral environment for a further 12 days. In experiment 2, the effectiveness of daytime cooling or nighttime cooling for improving milk production in hot environment was compared. While ten lactating Japanese Saanen goats (aged 2 years, weighing 41.0 kg) during early lactation were used in experiment 1, ten lactating goats (aged 2 years, weighing 47.5 kg) during mid-lactation were used in experiment 2. The animals were fed 300 g of concentrated feed and excessive amounts of crushed alfalfa hay cubes twice daily. Water was given ad libitum. The animals were milked twice daily. When exposed to a hot environment, milk yield and composition decreased significantly (p<0.05). Milk yield in the hot environment did not change with daytime cooling, but tended to increase with nighttime cooling. Compared to the daytime cooling, milk components percentages in the nighttime cooling were not significantly different but the milk components yields in the nighttime cooling were significantly higher (p<0.05). The results indicate that nighttime cooling is more effective than daytime cooling in the reduction of milk production declines in lactating goats exposed to a hot environment.

배수성이 다른 자생 버뮤다그래스의 휴면 전후 항산화 효소활성 및 세포막 안정성 변화 (Antioxidant Enzyme Activity and Cell Membrane Stability of Korean Bermudagrass Genotypes Different in Ploidy at Dormant Stage)

  • 이긍주;이혜정;마기윤;전영주;김인경
    • 아시안잔디학회지
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    • 제25권1호
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    • pp.17-21
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    • 2011
  • 기존 보고된 바에 의하면 한국 자생 버뮤다그래스는 군집 내에서 형태학, 생육 특성, 세포학적 특성에 대해 유전적으로 매우 다양한 변이를 보여주었다. 버뮤다그래스의 염색체 수와 핵 DNA 량에 따르면 배수성 수준의 범위가, 3배 체(2n=3x), 4배체(2n=4x), 5배체(2n=5x), 6배체(2n=6x)로 나타났었다. 본 연구에서는 한국에서 휴면이 유도되는저온과 짧은 일장에 대한 항산화효소(superoxide dismutase, catalase, peroxidase, ascorbate peroxidase)의 다양한 반응과 각 버뮤다그래스 세포형의 세포막 안정성을 조사하였다. 모든 항산화효소는 휴면 기간동안 높게 나타났으나, 과산화수소를 물과 산소 분자로 변환시키는 헴기를 함유한 카탈라제는 6배체 버뮤다그래스를 제외한 세 개의 세포형에서 휴면이 개시되기 전에 활성화되었다. 상대적으로 세엽이며 생육속도가 빠른3배체와 4배체는 superoxide dismutase와 peroxidase 효소의 활성이 증가됨을 확인하였다. 수산기를 가진 라디칼에 의해 손상을 받은 세포막에서 지질과산화의 산물인 말론디알데히드(MDA)는 온도가 감소함에 따라 모든 세포형에서 증가되었고, 방어적인 항산화효소를 더 갖고 있는 3배체와 4배체는 MDA 생산이 현저하게 더 낮게 나타났다. 전해질 유출은 5배체와 6배체에서 더 높았던 것과 유사하게, 저온이 적용될 때 외견상으로 세포막에 더 손상을 받는 것 같았다. 실험 결과, 서로 다른 세포형(cytotype)의 항산화 반응은 유전적으로 특이적이며, 이는 버뮤다그래스에서 저온 저항성과의 연관성을 분자 수준에서 더 연구하는 것이 필요하다.

Growth, Blood Metabolites, and Health of Holstein Calves Fed Milk Replacer Containing Different Amounts of Energy and Protein

  • Lee, H.J.;Khan, M.A.;Lee, W.S.;Kim, H.S.;Ki, K.S.;Jang, S.J.;Hur, T.Y.;Khan, M.S.;Choi, Y.J.
    • Asian-Australasian Journal of Animal Sciences
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    • 제21권2호
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    • pp.198-203
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    • 2008
  • This study was conducted to compare the effects of feeding high protein and low energy milk replacer (HPR; CP 25%, ME 3.6 Mcal/kg DM) with low protein and high energy milk replacer (HPR; CP 21%, ME 4.2 Mcal/kg DM) on feed consumption, body weight (BW) gain, health and selected blood metabolites in Holstein calves during the pre-weaning period. At each feeding, each milk replacer (MR) was prepared by mixing 0.125 kg of dry MR in 1L of warm ($60^{\circ}C$) water. The calves were fed either HPR (n = 10) or HER (n = 10) using mobile plastic bottles fitted with soft rubber nipples. All calves received 1.8L diluted MR at each feeding 3 times daily during the first 4 weeks of age; feeding frequency was reduced to 2 times daily for the next 2 weeks of age and then to once daily during the last week of the experiment. Jugular blood was sampled in calves at day 7, 14, 21, 35 and 49 of age to enumerate selected metabolites. Daily MR, starter and hay intake during the pre-weaning period were similar in calves fed HPR and HER. Consumption of starter, MGH and total DM steadily increased with the age of calves. Final BW, daily BW gain and feed efficiency of calves were not affected by treatments. Serum glucose, cholesterol, creatinine were decreased (p<0.05) and blood urea N was increased (p<0.05) in calves fed HER or HPR as they grew older. Serum glucose, total protein and albumin concentrations in calves were not affected by treatments. Serum GPT and GOT concentrations were higher (p<0.05) in calves on HPR than on HER. Scouring score, days scoured, respiratory score, rectal temperature and general appearance were similar in calves fed HPR and HER. Poor general appearance (dullness and droopy ears) of calves fed either HPR or HER reflected nutritional insufficiency and stress. In conclusion, energy and protein concentrations in MR did not affect feed intake and BW gain in Holstein calves during the pre-weaning period. Poor general appearance and lower BW gain of calves compared to those reported in the literature for milk fed calves prompt a demand for further research to improve the daily nutrient supply to MR-fed calves.

Perception of Patients with Cancer towards Support Management Services and Use of Complementary Alternative Medicine - a Single Institution Hospital-Based Study in Saudi Arabia

  • Sait, Khalid Hussain;Anfinan, Nisrin Mohammad;Eldeek, Basem;Al-Ahmadi, Jawher;Al-Attas, Maha;Sait, Hesham Khalid;Basalamah, Hussain Abdullah;Al-Ama, Nabeel;El Sayed, Mohamed Ezzat
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권6호
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    • pp.2547-2554
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    • 2014
  • Background: To evaluate the perception of cancer patients toward treatment services and influencing factors and to inquire about the use of complementary alternative medicine (CAM). Materials and Methods: Information was obtained through pre-tested structured questionnaires completed by cancer patients during treatment at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. Results: Of 242 patients, 137 (64.6%) accepted to enter this study. Most were Saudi (n=93, 68%), female (n=80, 58%), educated at university (n=71, 52%), married (n=97, 72%) and with breast cancer (n=36, 26%). One-hundred (73%) patients were satisfied with the services provided; 61% were Saudi. Ninety-four (68%) respondents were satisfied with the explanation of their cancer. Twenty-eight (21.6%) patients received CAM, of them 54.0% received herbal followed by rakia (21.0%), nutritional supplements/vitamins (7.0%) and Zamam water (18.0%), with significant differences among them (p =0.004). Seven (5%) patients believed this therapy could be used alone; 34 (25%) patients believed it could be used with other treatments, regardless of whether they themselves used this therapy. Fifty-three (53%) satisfied patients felt they received enough support; 31 (58%) patients received support from family and friends; 22 (41.6%) patients received support from the health-care team. Patients who received information about their disease from their physicians and those who felt they had enough support were more satisfied. The patients who took alternative treatment were older age, mostly female and highly educated but values did not reach significance. Conclusions: We stress enhancing the educational and supportive aspects of cancer-patient services to improve their treatment satisfaction and emphasize the need for increasing the educational and awareness programs offered to these patients.