• 제목/요약/키워드: Materials testing

검색결과 2,677건 처리시간 0.034초

Score Based Risk Assessment of Lung Cancer and its Evaluation for Bangladeshi People

  • Mukti, Roushney Fatima;Samadder, Pratul Dipta;Emran, Abdullah Al;Ahmed, Farzana;Imran, Iqbal Bin;Malaker, Anyanna;Yeasmin, Sabina
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제15권17호
    • /
    • pp.7021-7027
    • /
    • 2014
  • Background: The problem of cancer, especially lung cancer, is very acute in Bangladesh. The present study was conducted to evaluate the risk of lung cancer among Bangladeshi people based on hereditary, socio-economic and demographic factors. Materials and Methods: This study was carried out in 208 people (patients-104, controls-104) from January 2012 to September 2013 using a structured questionnaire containing details of lung cancer risk factors including smoking, secondhand smoke, tobacco leaf intake, age, gender, family history, chronic lung diseases, radiotherapy in the chest area, diet, obesity, physical activity, alcohol consumption, occupation, education, and income. Descriptive statistics and testing of hypotheses were used for the analysis using SPSS software (version 20). Results: According to this study, lung cancer was more prevalent in males than females. Smoking was the highest risk factor (OR=9.707; RR=3.924; sensitivity=0.8872 and P<0.0001) followed by previous lung disease (asthma, tuberculosis etc.) (OR=7.095; RR=1.508; sensitivity=0.316 and P<0.0001)) for male patients. Highly cooked food (OR=2.485; RR=1.126; sensitivity=0.418 and P=0.004)) and also genetic inheritance (OR=1.93; RR=1.335; sensitivity=0.163 and P=0.138) demonstrated significant correlation with lung cancer as risk factors after these two and alcohol consumption was not prevalent. On the other hand, for female patients, tobacco leaf intake represented the highest risk (OR=2.00; RR=1.429; sensitivity= 0.667 and P=0.5603) while genetic inheritance and highly cooked food also correlate with lung cancer but not so significantly. Socioeconomic status and education level also play important roles in causing lung cancer. Some 78.5% male and 83.3% of female cancer patients were rural residents, while 58.2% lived at the margin or below the poverty line. Most male (39.8%) and female (50.0%) patients had completed only primary level education, and 27.6% male and 33.3% female patients were illiterate. Smoking was found to be more prevalent among the less educated persons. Conclusions: The results obtained in this study indicate the importance of creating awareness about lung cancer risk factors among Bangladeshi people and making appropriate access to health services for the illiterate, poor, rural people.

전방 십자 인대 재건술 후 감염의 치료: 이식건의 보존 (Treatment of Infection after Anterior Cruciate Ligament Reconstruction: Graft Retention)

  • 김형준;고해석;문찬웅;최남용;인용;김민우
    • 대한관절경학회지
    • /
    • 제11권2호
    • /
    • pp.99-103
    • /
    • 2007
  • 목적: 이 연구의 목적은 전방 십자 인대 재건술 후 발생한 감염 환자에서 이식건을 보존하고 치료한 저자들의 결과를 후향적으로 분석하여 보고하는 것이다. 대상 및 방법: 2000년 1월부터 2005년 12월까지 시행한 511예의 전방 십자 인대 재건술 중 감염의 합병증이 있었던 5예(0.97%)를 대상으로 하였다. 전 예에서 전방 십자 인대를 보존한 상태에서 세척술과 활액막 절제술, 항생제 투여로 치료하였다. 결과: 평균 추시기간은 34개월이었다. 감염이 재발된 예는 없었다. International Knee Documentation Committee 평가 기준상 거의 정상의 결과를 보인 예가 2예, 비정상의 결과를 보인 예가 3예였다. KT-2000 관절계를 이용한 최대 도수 부하 검사 상 전방 불안정성을 보인 예는 없었다. 결론: 저자들은 전방 십자 인대 재건술 후 감염 발생시 전방 십자 인대를 보존하고 치료하여 감염의 재발이 없었다.

  • PDF

생체 유리와 소다 유리침투에 따른 알루미나 세라믹의 굴곡 강도 및 PBS에서의 표면 생성물 연구 (Bending strength of alumina coated with bioglass and soda lime glass and the precipitation on the surface of coated alumina in PBS)

  • 유재양
    • 대한치과기공학회지
    • /
    • 제30권2호
    • /
    • pp.39-45
    • /
    • 2008
  • Titanium and its alloys are widely used as dental implants materials because of their excellent mechanical properties. However, the alumina and zirconia ceramics are preferred to use as the substitute of Ti implants because there is a problems in esthetics and biocompatibility in Ti implant. The the glass infiltrated alumina ceramics are studied to increase the toughness and biocompatibility. The 45S5 and soda-lime glass powder was mixed with ethanol at ratio of 1:1 and brushed on the surface of alumina. Then it was heat treated in the electric furnace at $1400^{\circ}C$ from 30 min. to 5 hours. The glass powder was controlled from 200 to $350{\mu}m$ using ball milling. After heat treatment, the glass infiltrated specimen was tested in universal testing machine to measure the bending strength. The surface microstructure of each specimen was observed with SEM. The biocompatibility of 45S5 and soda-lime glass coated alumina was investigated using PBS at $36.5^{\circ}C$ incubator. The specimen was immersed in PBS for 3, 5, 7, 10 days. After that, the surface morphology was investigated with SEM. As the results of experiment, the 45S5 bioglass infiltrated alumina show the increase of bending strength according to the increasing of heat treatment time from 30 min. to 5 hours at $1400^{\circ}C$ Finally the 1370N bending strength of alumina increased to 1958N at 5 hours heat treatment, which shows 1.4 times higher. In contrast to this, the soda lime glass infiltrated alumina ceramics shows the convex curve according to heat treatment time. Thus it shows maximum bending strength of 1820N at 1 hour heat treatment of $1400^{\circ}C$ It gives 1.3 times higher. However, the bending strength of soda lime glass infiltrated alumina is decreasing with increasing heat treatment time after 1 hour. The precipitation on the surface of 45S5 glass infiltrated alumina was revealed as a sodium phosphate ($Na_{6}P_{6}O_{24}6H_{2}O$) and the amount of precipitation is increasing with increasing of immersion time in PBS. In contrast to this, there is no precipitation are observed on the surface of soda lime glass infiltrated alumina. This implies that 45S5 glass infiltrated alumina brings more biocompatible when it is implanted in human body.

  • PDF

In vitro study of the fracture resistance of monolithic lithium disilicate, monolithic zirconia, and lithium disilicate pressed on zirconia for three-unit fixed dental prostheses

  • Choi, Jae-Won;Kim, So-Yeun;Bae, Ji-Hyeon;Bae, Eun-Bin;Huh, Jung-Bo
    • The Journal of Advanced Prosthodontics
    • /
    • 제9권4호
    • /
    • pp.244-251
    • /
    • 2017
  • PURPOSE. The purpose of this study was to determine fracture resistance and failure modes of three-unit fixed dental prostheses (FDPs) made of lithium disilicate pressed on zirconia (LZ), monolithic lithium disilicate (ML), and monolithic zirconia (MZ). MATERIALS AND METHODS. Co-Cr alloy three-unit metal FDPs model with maxillary first premolar and first molar abutments was fabricated. Three different FDPs groups, LZ, ML, and MZ, were prepared (n = 5 per group). The three-unit FDPs designs were identical for all specimens and cemented with resin cement on the prepared metal model. The region of pontic in FDPs was given 50,000 times of cyclic preloading at 2 Hz via dental chewing simulator and received a static load until fracture with universal testing machine fixed at $10^{\circ}$. The fracture resistance and mode of failure were recorded. Statistical analyses were performed using the Kruskal-Wallis test and Mann-Whitney U test with Bonferroni's correction (${\alpha}=0.05/3=0.017$). RESULTS. A significant difference in fracture resistance was found between LZ ($4943.87{\pm}1243.70N$) and ML ($2872.61{\pm}658.78N$) groups, as well as between ML and MZ ($4948.02{\pm}974.51N$) groups (P<.05), but no significant difference was found between LZ and MZ groups (P>.05). With regard to fracture pattern, there were three cases of veneer chipping and two interfacial fractures in LZ group, and complete fracture was observed in all the specimens of ML and MZ groups. CONCLUSION. Compared to monolithic lithium disilicate FDPs, monolithic zirconia FDPs and lithium disilicate glass ceramics pressed on zirconia-based FDPs showed superior fracture resistance while they manifested comparable fracture resistances.

Effect of liners and primers on tensile bond strength between zirconia and resin-based luting agent

  • Jo, Eun-Hye;Huh, Yoon-Hyuk;Ko, Kyung-Ho;Park, Chan-Jin;Cho, Lee-Ra
    • The Journal of Advanced Prosthodontics
    • /
    • 제10권5호
    • /
    • pp.374-380
    • /
    • 2018
  • PURPOSE. The effect of silica-based glass-ceramic liners on the tensile bond strength between zirconia and resin-based luting agent was evaluated and compared with the effect of 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-containing primers. MATERIALS AND METHODS. Titanium abutments and zirconia crowns (n = 60) were fabricated, and the adhesive surfaces of the specimens were treated by airborne-particle abrasion. The specimens were divided into 5 groups based on surface treatment: a control group, 2 primer groups (MP: Monobond Plus; ZP: Z Prime Plus), and 2 liner groups (PL: P-containing Liner; PFL: P-free Liner). All specimens were cemented with self-adhesive resin-based luting agent. After 24-hour water storage and thermocycling (5,000 cycles, $5^{\circ}C/55^{\circ}C$), the tensile bond strength was measured using a universal testing machine. Failure mode analysis and elemental analysis on the bonding interface were performed. The data were analyzed using Kruskal-Wallis test, Dunn's post hoc test, and Fisher's exact test. RESULTS. The liner groups and primer groups showed significantly higher tensile bond strengths than that of the control group (P<.05). PFL showed a significantly higher tensile bond strength than the primer groups (P<.05). The percentage of mixed failure was higher in the primer groups than in the control group (P<.001), and all the specimens showed mixed failure in the liner groups (P<.001). A chemical reaction area was observed at the bonding interface between zirconia and liner. CONCLUSION. The application of liner significantly increased the tensile bond strength between zirconia and resin-based luting agent. PFL was more effective than MDP-containing primers in improving the tensile bond strength with the resin-based luting agent.

지르코니아 임플란트 지대주의 기계적 강도에 관한 연구 (Mechanical strength of Zirconia Abutment in Implant Restoration)

  • 신성애;김창섭;조욱;정창모;전영찬;윤지훈
    • 구강회복응용과학지
    • /
    • 제25권4호
    • /
    • pp.349-360
    • /
    • 2009
  • 목적: 임플란트 보철 수복에서 심미적 요구도가 증진되면서 최근에는 고강도, 고인성을 지니면서 생체적합성 우수하고 치아의 색과 조화로운 지르코니아 지대주의 사용이 증가하는 추세이다. 몇몇 임상보고를 통해 지르코니아 지대주의 우수한 주위조직 반응과 단기간의 성공적인 결과가 보고 되었으나, 장기간의 안정성을 평가하는 기계적 강도에 관한 연구는 미흡한 실정이다. 이에 본 연구에서는 직경, 각도, 연결방식이 상이한 임플란트 고정체 - 지르코니아 지대주의 단순 파절강도와 반복하중에 의한 피로한계 측정을 통해 지르코니아 지대주의 기계적 안정성을 평가해 보고자 하였다. 재료와 방법: ISO규정에 따라 지르코니아 지대주-고정체를 변연골이 3mm 흡수된 조건에서 $30^{\circ}$경사하중으로 압축굽힘강도를 측정하고, 그 값의 80%를 최대하중으로 10%를 최소하중으로 하여 10Hz의 sine형 반복하중을 $5{\times}10^6$ 주기를 초과하는 조건의 내구성한계를 측정하였다. 지르코니아 지대주로는 regular diameter를 가지면서 external butt joint의 straight 지대주와 $17^{\circ}$ angled 지대주, 그리고 narrow diameter 이면서 external butt joint의 straight 지대주와 internal conical joint의 straight 지대주를 사용하였다. 압축굽힘강도 값을 일원분산분석과 사후검정으로 검증하였으며, 피로파절면을 전자주사현미경을 통해 관찰했다. 결과: 압축굽힘강도는 최소 927N 이상으로, 직경의 차이에 따른 유의한 차이를 보였으며( P<.05), 내구성 한계는 503N에서 868N까지의 번위를 보였다. 결론: 지르코니아 지대주는 구강내 기능하중을 견딜수 있는 적절한 기계적 강도를 가지는 것으로 판단된다.

위암에서 정량적 역전사 중합효소연쇄반응을 이용한 다중 표지자 분석 (Multiple Genetic Marker Analysis with Using Quantitative RT-PCR in Gastric Cancer)

  • 유문원;이혁준;최수민;유지은;허근;김영국;양한광
    • Journal of Gastric Cancer
    • /
    • 제7권2호
    • /
    • pp.59-66
    • /
    • 2007
  • 목적: 위암 세포주 및 조직에서 다중 표지자 mRNA 발현을 정량적 RT-PCR 검사를 통해 확인함으로써 이들 표지자를 이용하여 위암의 복강내 미세전이 진단이 가능한가를 평가하고자 본 연구를 시행하였다. 대상 및 방법: 12개의 인체 위암 세포주와 10개의 위암 조직을 대상으로 Carcinoembryonic antigen (CEA), Cytokeratin 20 (CK20), Dopa decarboxylase (DDC), L-3-phosphoserine phosphatase (L3PP)의 네 가지 mRNA를 이용한 정량적 RT-PCR 다중 표지자 분석을 시행하였다. 결과: 12개의 인체 위암 세포주 중 CEA는 4개(33%), CK-20는 1개(8%), DDC는 6개(50%), L3PP는 12개 세포주 모두(100%)에서 과발현되었다. 10개의 위암 조직 중 CEA는 9개, CK20은 3개, DDC는 9개, L3PP는 10개 조직 모두에서 과발현되었다. L3PP는 모든 위암 세포주와 조직에서 과발현을 나타내었으나 과발현 정도는 비교적 낮게 측정된 반면, CEA와 DDC는 일부 위암 세포주 및 조직에서만 과발현을 나타내었지만 파발현 시 충분한 발현도를 나타내었다. 결론: 위암 환자에서 하나 이상의 암 특이적 유전자를 이용한 다중 표지자 분석은 단일 표지자 분석이 가지는 단점을 보완할 수 있을 것으로 예상되며, CEA, DDC, 및 L3PP의 세 가지 mRNA가 후보 유전자로 사용될 수 있을 것으로 생각한다.

  • PDF

Virulence Genes of Helicobacter pylori in Gastritis, Peptic Ulcer and Gastric Cancer in Laos

  • Vannarath, Sengdao;Vilaichone, Ratha-Korn;Rasachak, Bouachanh;Mairiang, Pisaln;Yamaoka, Yoshio;Shiota, Seiji;Binh, Tran Thanh;Mahachai, Varocha
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제15권20호
    • /
    • pp.9027-9031
    • /
    • 2014
  • Background: Helicobacter pylori (H. pylori) infection is an established cause of peptic ulcers and gastric cancer. The aim of this study was to identify H. pylori genotypes and to examine their associations with geographical regions and gastritis, peptic ulcers and gastric cancer in Laos. Materials and Methods: A total of 329 Lao dyspeptic patients who underwent gastroscopy at Mahosot Hospital, Vientiane, Laos during December 2010 - March 2012 were enrolled. Two biopsy specimens (one each from the antrum and corpus) were obtained for CLO testing and only CLO test-positive gastric tissue were used to extract DNA. PCR and sequencing were identified for variants of the cagA and vacA genotypes. Results: Some 119 Laos patients (36.2%) were found to be infected with H. pylori including 83 with gastritis, 13 with gastric ulcers (GU), 20 with duodenal ulcers (DU) and 3 with gastric cancer. cagA was detected in 99.2%. East-Asian-type cagA (62%) and vacA s1c (64.7%) were predominant genotypes in Laos. vacA s1c-m1b was significantly higher in GU than gastritis (53.8% vs. 24.1%; P-value=0.04) whereas vacA s1a-m2 was significantly higher in DU than gastritis (40.0% vs. 16.9%; P-value=0.03). East-Asian-type cagA and vacA s1c were significantly higher in highland than lowland Lao (100% vs. 55.8%; P-value=0.001 and 88.2% vs. 61.5%, P-value=0.03 respectively). Conclusions: H. pylori is a common infection in Laos, as in other countries in Southeast Asia. The cagA gene was demonstrated in nearly all Laos patients, cagA and vacA genotypes being possible important factors in explaining H. pylori infection and disease outcomes in Laos.

Effect of IL-1 Polymorphisms, CYP2C19 Genotype and Antibiotic Resistance on Helicobacter pylori Eradication Comparing Between 10-day Sequential Therapy and 14-day Standard Triple Therapy with Four-Times-Daily-Dosing of Amoxicillin in Thailand: a Prospective Randomized Study

  • Phiphatpatthamaamphan, Kittichet;Vilaichone, Ratha-korn;Siramolpiwat, Sith;Tangaroonsanti, Anupong;Chonprasertsuk, Soonthorn;Bhanthumkomol, Patommatat;Pornthisarn, Bubpha;Mahachai, Varocha
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제17권4호
    • /
    • pp.1903-1907
    • /
    • 2016
  • Background: Studies of effects of IL-1 polymorphisms, CYP2C19 genotype together with antibiotic resistance for H. pylori eradication are rare worldwide. The present study was designed to evaluate efficacy of 10-day sequential therapy (SQT) and 14-day standard triple therapy (STT) with four- times-daily dosing of amoxicillin for H. pylori eradication related to these important host and bacterial factors in Thailand. Materials and Methods: This prospective randomized study was performed during March 2015 to January 2016. H. pylori infected gastritis patients were randomized to receive 10-day sequential therapy and 14-day standard triple therapy. CYP2C19 genotyping, IL1 polymorphism (IL-1B and IL-1RN genotypes) and antibiotic susceptibility tests were performed in all patients. 13C-UBT was conducted to confirm H. pylori eradication at least 4 weeks after treatment. Results: A total of 100 patients (33 males and 67 females, mean age=51.1 years) were enrolled. Eradication rate by PP analysis was 97.9% (47/48) with the 10-day SQT regimen and 87.8% (43/49) with 14-day STT regimen (97.9% vs 87.8%; p-value=0.053). Antibiotic susceptibility testing demonstrated 45% resistance to metronidazole, 14.8% to clarithromycin, and 24.1% to levofloxacin. CYP2C19 genotyping revealed 44.9% RM, 49% IM and 6.1% PM. IL-1B and IL-1RN genotypes were demonstrated as 21.4% for CC, 48.1% for TC, 36.8% for TT, 72.7% for 1/1, and 21.2% for 1/2 genotypes, respectively. The 10-day SQT regimen provided 100% eradication in patients with clarithromycin or dual clarithromycin and levofloxacin H. pylori resistant strains. Moreover, the 10-day SQT regimen resulted in a 100% eradication rate in all patients with CYP2C19 genotype RM and almost type of IL-1B (TC and TT) and IL1-RN genotypes ( 1/2 and other). Conclusions: Treatment with 10-day sequential therapy is highly effective for H. pylori eradication regardless of the effects of clarithromycin resistance, dual clarithromycin and levofloxacin resistance, CYP2C19 genotype, IL-1B and IL1-RN genetic polymorphisms and can be used as effective first line therapy in Thailand.

Screening for Lynch Syndrome in Young Colorectal Cancer Patients from Saudi Arabia Using Microsatellite Instability as the Initial Test

  • Alqahtani, Masood;Grieu, Fabienne;Carrello, Amerigo;Amanuel, Benhur;Mashour, Miral;Alattas, Rabab;Al-Saleh, Khalid;Alsheikh, Abdulmalik;Alqahtani, Sarah;Iacopetta, Barry
    • Asian Pacific Journal of Cancer Prevention
    • /
    • 제17권4호
    • /
    • pp.1917-1923
    • /
    • 2016
  • Background: Lynch Syndrome (LS) is a familial cancer condition caused by germline mutations in DNA mismatch repair genes. Individuals with LS have a greatly increased risk of developing colorectal cancer (CRC) and it is therefore important to identify mutation carriers so they can undergo regular surveillance. Tumor DNA from LS patients characteristically shows microsatellite instability (MSI). Our aim here was to screen young CRC patients for MSI as a first step in the identification of unrecognized cases of LS in the Saudi population. Materials and Methods: Archival tumor tissue was obtained from 284 CRC patients treated at 4 institutes in Dammam and Riyadh between 2006 and 2015 and aged less than 60 years at diagnosis. MSI screening was performed using the BAT-26 microsatellite marker and positive cases confirmed using the pentaplex MSI analysis system. Positive cases were screened for BRAF mutations to exclude sporadic CRC and were evaluated for loss of expression of 4 DNA mismatch repair proteins using immunohistochemistry. Results: MSI was found in 33/284 (11.6%) cases, of which only one showed a BRAF mutation. Saudi MSI cases showed similar instability in the BAT-26 and BAT-25 markers to Australian MSI cases, but significantly lower frequencies of instability in 3 other microsatellite markers. Conclusions: MSI screening of young Saudi CRC patients reveals that approximately 1 in 9 are candidates for LS. Patients with MSI are strongly recommended to undergo genetic counselling and germline mutation testing for LS. Other affected family members can then be identified and offered regular surveillance for early detection of LS-associated cancers.