Many studies on polydiacetylene(PDA) have been investigated to apply to chemical and biological sensors due to their unique optical properties of color change from blue to red and fluorescence change from non-fluorescence to red fluorescence. Especially, high sensitivity against specific molecules is very important to apply polydiacetylenes to various sensors. In this study, we examined the effect of sensitivity enhancement of 10,12-pentacosadynoic acid(PCDA) vesicles in detection ${\alpha}$-cyclodextrin(CD) according to control of vesicle size by filters with different pore sizes and polymerization temperature. Colorimetric response(CR) was calculated using visible spectrometer. In order to investigate the effect of vesicle size on sensitivity of PDA vesicles, two PCDA vesicles were filtered without filtration and with 0.22 ${\mu}m$ filter. The two PCDA vesicles were polymerized at $25^{\circ}C$ and were incubated with ${\alpha}$-CD(5 mM) for 30 min. The CRs of the former and latter vesicles were 31.4% and 74.0%, respectively. Then, two PCDA vesicles filtered with 0.22 ${\mu}m$ filter were polymerized at $25^{\circ}C$ and $5^{\circ}C$ and were reacted with ${\alpha}$-CD(5 mM) for 30 min to examine the effect of polymerization temperature. The CRs of the former and latter vesicles were 74.0 and 99.2%, respectively. This suggests that vesicle sizes and polymerization temperature are key factors in enhancing the sensitivity of PDA vesicles. In addition, these results are expected to be useful to apply the PDA vesicles as biosensors to detect DNA, protein, and cells.
Salarizadeh, Navvabeh;Sadri, Minoo;Hosseini, Hassan;Sajedi, Reza. H.
Carbon letters
/
v.24
/
pp.103-110
/
2017
Carbon-based magnetic nanostructures in several instances have resulted in improved physicochemical and catalytic properties when compared to multi-wall carbon nanotubes (MWCNTs) and magnetic nanoparticles. In this study, magnetic MWCNTs with a structure of $Ni_xZn_xFe_2O_4/MWCNT$ as peroxidase mimics were fabricated by the one-pot hydrothermal method. The structure, composition and morphology of the nanocomposites were characterized with X-ray diffraction (XRD), Fourier transform infrared spectroscopy and transmission electron microscopy. The magnetic properties were investigated with a vibrating sample magnetometer. The peroxidase-like catalytic activity of the nanocomposites was investigated by colorimetric and electrochemical tests with 3,3',5,5'-tetramethylbenzidine (TMB) and $H_2O_2$ as the substrates. The results show that the synthesis of the nanocomposites was successfully performed. XRD analysis confirmed the crystalline structures of the $Ni_xZn_xFe_2O_4/MWCNT$ nanohybrids and MWCNTs. The main peaks of the $Ni_xZn_xFe_2O_4/MWCNT$s crystals were presented. The $Ni_{0.25}Zn_{0.25}Fe_2O_4/MWCNT$ and $Ni_{0.5}Zn_{0.5}Fe_2O_4/MWCNT$ nanocatalysts showed nearly similar physicochemical properties, but the $Ni_{0.5}Zn_{0.5}Fe_2O_4/MWCNT$ nanocatalyst was more appropriate than the $Ni_{0.25}Zn_{0.25}Fe_2O_4/MWCNT$ nanocatalyst in terms of the magnetic properties and catalytic activity. The optimum peroxidase-like activity of the nanocatalysts was obtained at pH 3.0. The $Ni_{0.5}Zn_{0.5}Fe_2O_4/MWCNT$ nanocatalyst exhibited a good peroxidase-like activity. These magnetic nanocatalysts can be suitable candidates for future enzyme-based applications such as the detection of glucose and $H_2O_2$.
Kim, Young-Il;Lee, Jang-Hoon;Park, Seung-Won;Choi, In-Hwa;Friedman, Scott L.;Woo, Hong-Jung;Kim, Young-Chul
Advances in Traditional Medicine
/
v.10
no.4
/
pp.254-262
/
2010
Artemisia capillaris (A. capillaries) is known to play roles in many cellular events, such as cell proliferation, differentiation, and apoptosis. We investigated the antifibrogenic efficacy of A. capillaris in the immortalized human hepatic stellate cell line LX2. Cell proliferation was determined by the MTT assay. Cell cycle was analyzed by the flow cytometry. Apoptotic cells were measured using a cell death detection ELISA. Caspase activity was detected by a colorimetric assay. The mRNA level of Bcl-2 and Bax mRNA were measured by real-time PCR. MEK and ERK protein were detected by Western blot analysis. We provide evidence that A. capillaris induces cell cycle arrest, apoptosis, and potently inhibits the mitogen-activated protein kinase pathway. A. capillaris inhibited cell proliferation of LX2 cells in a dose- and time-dependent manner, increased the apoptosis fraction at cell cycle analysis with an accompanying DNA fragmentation, and resulted in a significant decrease in Bcl-2 mRNA levels and an increase in Bax expression. Exposure of LX2 cells to A. capillaris induced caspase-3 activation, but co-treatment of A. capillaris with the pan-caspase inhibitor Z-VAD-FMK, and the caspase-3 inhibitor Z-DEVE-FMK, blocked apoptosis. A. capillaris down-regulated Mcl-1 protein levels and inhibited phosphorylation of MEK/ERK, suggesting that it mediates cell death in LX2 cells through the down-regulation of Mcl-1 protein via a MEK/ERK-independent pathway.
Loop-mediated isothermal amplification (LAMP) developed by Notomi et al. (2000) has made it possible to amplify DNA with high specificity, efficiency and rapidity under isothermal conditions. The ultimate products of LAMP are stem-loop structures with several inverted repeats of the target sequence and cauliflower-like patterns with multiple loops shaped by annealing between every other inverted repeats of the amplified target in the similar strand. Because the amplification process in LAMP is achieved by using four to six distinct primers, it is expected to amplify the target region with high selectivity. However, evaluation of reaction accuracy or quantitative inspection make it necessary to append other procedures to scrutinize the amplified products. Hitherto, various techniques such as turbidity assessment in the reaction vessel, post-reaction agarose gel electrophoresis, use of intercalating fluorescent dyes, real-time turbidimetry, addition of cationic polymers to the reaction mixture, polyacrylamide gel-based microchambers, lateral flow dipsticks, fluorescence resonance energy transfer (FRET), enzyme-linked immunosorbent assays and nanoparticle-based colorimetric tests have been utilized for this purpose. In this paper, we reviewed the best-known techniques for evaluation of LAMP amplicons and their applications in molecular biology beside their advantages and deficiencies. Regarding the properties of each technique, the development of innovative prompt, cost-effective and precise molecular detection methods for application in the broad field of cancer research may be feasible.
Naringin, a bioflavonoid found in Citrus seeds, inhibits proliferation of cancer cells. The objectives of this study were to investigate the mode and mechanism(s) of hepatocellular carcinoma HepG2 cell death induced by naringin. The cytotoxicity of naringin towards HepG2 cells proved dose-dependent, measured by MTT assay. Naringin-treated HepG2 cells underwent apoptosis also in a concentration related manner, determined by annexin V-fluorescein isothiocyanate (FITC) and propidium iodide (PI) employing flow cytometry. Mitochondrial transmembrane potential (MTP) measured using 3,3'-dihexyloxacarbocyanine iodide ($DiOC_6$) and flow cytometer was reduced concentration-dependently, which indicated influence on the mitochondrial signaling pathway. Caspase-3, -8 and -9 activities were enhanced as evidenced by colorimetric detection of para-nitroaniline tagged with a substrate for each caspase. Thus, the extrinsic and intrinsic pathways were linked in human naringin-treated HepG2 cell apoptosis. The expression levels of pro-apoptotic Bax and Bak proteins were increased whereas that of the anti-apoptotic Bcl-xL protein was decreased, confirming the involvement of the mitochondrial pathway by immunoblotting. There was an increased expression of truncated Bid (tBid), which indicated caspase-8 proteolysis activity in Bid cleavage as its substrate in the extrinsic pathway. In conclusion, naringin induces human hepatocellular carcinoma HepG2 cell apoptosis via mitochondria-mediated activation of caspase-9 and caspase-8-mediated proteolysis of Bid. Naringin anticancer activity warrants further investigation for application in medical treatment.
Journal of The Korean Society of Inherited Metabolic disease
/
v.14
no.1
/
pp.1-9
/
2014
Many inborn errors of metabolism can be completely cured with early detection and early treatment. This is why neonatal screening on inborn errors of metabolism is implemented worldwide. In 1991, the Ministry of Health & Social affairs adopted a nationwide service program for neonatal screening of phenylketonuria, galactosemia, maple syrup urine disease, homocystinuria, histidinemia and congenital hypothyroidism for newborns delivered from low class pregnant women registered in health centers. Government decreased the test items from six to two, PKU and congenital hypothyroidism to increase test numbers with same budget from 1995. 78 laboratories wanted to participate for neonatal screening test in 1999. Government decided to screen six items of PKU, congenital hypothyroidism, maple syrup urine disease, homocystinuria, galactosemia and congenital adrenal hyperplasia from 2006. In 2014, thirteen laboratories are participating. Inter laboratory quality control was started 6 times a year from 1994. In case a patient with an inherited metabolic disease is diagnosed by screening of government program, special milk is provided at government's expense. According to the government project, from 1997 to 2013, 7,080,569 newborns were screened. 144 PKU, 2.451 congenital hypothyroidism were detected. So incidence of PKU is 1/49,170 and congenital hypothyroidism is 1/2,888. The cost benefit of performing screening procedures coupled with treatment has been estimated to be as high as 1.77 times in PKU, 11.11 times in congenital hypothyroidism than cost without screening. By January 2007, many European countries had expanded of their newborn screening programs by inclusion of Tandem mass spectrometry. We are trying to increase the budget to test all newborns for Tandem mass spectrometry from 2016. We are considering four to five central laboratories which cover all newborns and are equipped with tandem mass spectrometer & enzyme immunoassay for TSH, 17OHP & enzyme colorimetric assay for galactose. And I hope to expand test including Wilson disease screening test and lysosomal storage diseases.
Hydrogen cyanide(HCN), formed from pyrolysis of various nitrogenous compounds such as protein, amino acids and nitrate in tobacco, is present in both the particulate phase and vapor phase of cigarette smoke. Typically the determination of HCN in cigarette smoke has been done through colorimetric and electrochemical techniques, such as fluorescence spectrometry, UV-spectrophotometry (UV), continuous flow analyzer (CFA), capillary GC-ECD and ion chromatography (IC). Most of these techniques are known to be time-consuming and some of them lack specificity or sensitivity. The available results from both our laboratory and reported literatures for 2R4F Kentucky reference cigarette, smoked under ISO condition, show a relatively wide variation ranging from 100 to 120 ug/cig of HCN. Especially, the precision and accuracy of the analytical results of HCN tend to get worse in low tar cigarettes and under intense smoking condition. In this paper, a more optimized analytical methods than previous ones are suggested. This method shows lower detection limit and has improved precision and accuracy, so it is applicable for wide tar level cigarettes under intense smoking condition as well as under ISO smoking condition. Important features of this method are improved sample collection and quantification systems such as the number of trapping units, volume, temperature and type of trapping solution. To avoid volatilization loss of HCN in analyzing mainstream smoke, it is highly recommended that pH values of trapping solutions should be maintained over 11 and cold traps should be used in collecting mainstream smoke.
The alkaline phosphatase (ALP) assay is a rapid and convenient method for verifying milk pasteurization. Since colorimetric ALP assays rely on subjective visual assessments, their results are especially unreliable near the detection limits. In this study, we attempted to establish quantitative criteria for residual ALP in milk by using a more objective method based on spectrophotometric measurements. Raw milk was heat-treated for 0, 10, 20, 30, and 40 min and then subjected to ALP assays. The quantitative criteria for residual ALP in the milk was determined as 2 μg phenol/mL of milk, which is just above the ALP value of milk samples heat-treated for 30 min. These newly proposed methodology and criteria could facilitate the microbiological quality control of milk.
Successful early diagnosis of cancer diseases such as lung, prostate, liver and adrenocortical carcinoma is a key step in determining the cost of treatment, survival rate, and cure rate. Most of current cancer diagnosis systems including biopsy, computed tomography (CT), positron emission tomography (PET)-CT, magnetic resonance imaging (MRI), ultrasonography, etc., require expensive and complicated equipment with highly trained human resources. Global medical and scientific communities have thus made numerous efforts on developing effective but rapid disease management system via introducing a wide spectrum of point-of-care medical diagnosis devices. Among them, a lateral flow immunoassay strip technique has gained a great attention due to many advantages such as cost-effectiveness, short inspection time, and user friendly accessibility. In this mini-review, we will highlight recent research trend on the development of colorimetry based LFIA strips for cancer diagnosis and discuss the future research direction and potential applications.
Objective: The aim of this study was to investigate the protective effect of wheat phytase as a structural decomposer of inflammatory nucleotides, extracellular adenosine triphosphate (ATP), and uridine diphosphate (UDP) on HT-29 cells. Methods: Phosphatase activities of wheat phytase against ATP and UDP was investigated in the presence or absence of inhibitors such as L-phenylalanine and L-homoarginine using a Pi Color Lock gold phosphate detection kit. Viability of HT-29 cells exposed to intact- or dephosphorylated-nucleotides was analyzed with an EZ-CYTOX kit. Secretion levels of pro-inflammatory cytokines (IL-6 and IL-8) in HT-29 cells exposed to substrate treated with or without wheat phytase were measured with enzyme-linked immunosorbent assay kits. Activation of caspase-3 in HT-29 cells treated with intact ATP or dephosphorylated-ATP was investigated using a colorimetric assay kit. Results: Wheat phytase dephosphorylated both nucleotides, ATP and UDP, in a dose-dependent manner. Regardless of the presence or absence of enzyme inhibitors (L-phenylalanine and L-homoarginine), wheat phytase dephosphorylated UDP. Only L-phenylalanine inhibited the dephosphorylation of ATP by wheat phytase. However, the level of inhibition was less than 10%. Wheat phytase significantly enhanced the viability of HT-29 cells against ATP- and UDP-induced cytotoxicity. Interleukin (IL)-8 released from HT-29 cells with nucleotides dephosphorylated by wheat phytase was higher than that released from HT-29 cells with intact nucleotides. Moreover, the release of IL-6 was strongly induced from HT-29 cells with UDP dephosphorylated by wheat phytase. HT-29 cells with ATP degraded by wheat phytase showed significantly (13%) lower activity of caspase-3 than HT-29 cells with intact ATP. Conclusion: Wheat phytase can be a candidate for veterinary medicine to prevent cell death in animals. In this context, wheat phytase beyond its nutritional aspects might be a novel and promising tool for promoting growth and function of intestinal epithelial cells under luminal ATP and UDP surge in the gut.
본 웹사이트에 게시된 이메일 주소가 전자우편 수집 프로그램이나
그 밖의 기술적 장치를 이용하여 무단으로 수집되는 것을 거부하며,
이를 위반시 정보통신망법에 의해 형사 처벌됨을 유념하시기 바랍니다.
[게시일 2004년 10월 1일]
이용약관
제 1 장 총칙
제 1 조 (목적)
이 이용약관은 KoreaScience 홈페이지(이하 “당 사이트”)에서 제공하는 인터넷 서비스(이하 '서비스')의 가입조건 및 이용에 관한 제반 사항과 기타 필요한 사항을 구체적으로 규정함을 목적으로 합니다.
제 2 조 (용어의 정의)
① "이용자"라 함은 당 사이트에 접속하여 이 약관에 따라 당 사이트가 제공하는 서비스를 받는 회원 및 비회원을
말합니다.
② "회원"이라 함은 서비스를 이용하기 위하여 당 사이트에 개인정보를 제공하여 아이디(ID)와 비밀번호를 부여
받은 자를 말합니다.
③ "회원 아이디(ID)"라 함은 회원의 식별 및 서비스 이용을 위하여 자신이 선정한 문자 및 숫자의 조합을
말합니다.
④ "비밀번호(패스워드)"라 함은 회원이 자신의 비밀보호를 위하여 선정한 문자 및 숫자의 조합을 말합니다.
제 3 조 (이용약관의 효력 및 변경)
① 이 약관은 당 사이트에 게시하거나 기타의 방법으로 회원에게 공지함으로써 효력이 발생합니다.
② 당 사이트는 이 약관을 개정할 경우에 적용일자 및 개정사유를 명시하여 현행 약관과 함께 당 사이트의
초기화면에 그 적용일자 7일 이전부터 적용일자 전일까지 공지합니다. 다만, 회원에게 불리하게 약관내용을
변경하는 경우에는 최소한 30일 이상의 사전 유예기간을 두고 공지합니다. 이 경우 당 사이트는 개정 전
내용과 개정 후 내용을 명확하게 비교하여 이용자가 알기 쉽도록 표시합니다.
제 4 조(약관 외 준칙)
① 이 약관은 당 사이트가 제공하는 서비스에 관한 이용안내와 함께 적용됩니다.
② 이 약관에 명시되지 아니한 사항은 관계법령의 규정이 적용됩니다.
제 2 장 이용계약의 체결
제 5 조 (이용계약의 성립 등)
① 이용계약은 이용고객이 당 사이트가 정한 약관에 「동의합니다」를 선택하고, 당 사이트가 정한
온라인신청양식을 작성하여 서비스 이용을 신청한 후, 당 사이트가 이를 승낙함으로써 성립합니다.
② 제1항의 승낙은 당 사이트가 제공하는 과학기술정보검색, 맞춤정보, 서지정보 등 다른 서비스의 이용승낙을
포함합니다.
제 6 조 (회원가입)
서비스를 이용하고자 하는 고객은 당 사이트에서 정한 회원가입양식에 개인정보를 기재하여 가입을 하여야 합니다.
제 7 조 (개인정보의 보호 및 사용)
당 사이트는 관계법령이 정하는 바에 따라 회원 등록정보를 포함한 회원의 개인정보를 보호하기 위해 노력합니다. 회원 개인정보의 보호 및 사용에 대해서는 관련법령 및 당 사이트의 개인정보 보호정책이 적용됩니다.
제 8 조 (이용 신청의 승낙과 제한)
① 당 사이트는 제6조의 규정에 의한 이용신청고객에 대하여 서비스 이용을 승낙합니다.
② 당 사이트는 아래사항에 해당하는 경우에 대해서 승낙하지 아니 합니다.
- 이용계약 신청서의 내용을 허위로 기재한 경우
- 기타 규정한 제반사항을 위반하며 신청하는 경우
제 9 조 (회원 ID 부여 및 변경 등)
① 당 사이트는 이용고객에 대하여 약관에 정하는 바에 따라 자신이 선정한 회원 ID를 부여합니다.
② 회원 ID는 원칙적으로 변경이 불가하며 부득이한 사유로 인하여 변경 하고자 하는 경우에는 해당 ID를
해지하고 재가입해야 합니다.
③ 기타 회원 개인정보 관리 및 변경 등에 관한 사항은 서비스별 안내에 정하는 바에 의합니다.
제 3 장 계약 당사자의 의무
제 10 조 (KISTI의 의무)
① 당 사이트는 이용고객이 희망한 서비스 제공 개시일에 특별한 사정이 없는 한 서비스를 이용할 수 있도록
하여야 합니다.
② 당 사이트는 개인정보 보호를 위해 보안시스템을 구축하며 개인정보 보호정책을 공시하고 준수합니다.
③ 당 사이트는 회원으로부터 제기되는 의견이나 불만이 정당하다고 객관적으로 인정될 경우에는 적절한 절차를
거쳐 즉시 처리하여야 합니다. 다만, 즉시 처리가 곤란한 경우는 회원에게 그 사유와 처리일정을 통보하여야
합니다.
제 11 조 (회원의 의무)
① 이용자는 회원가입 신청 또는 회원정보 변경 시 실명으로 모든 사항을 사실에 근거하여 작성하여야 하며,
허위 또는 타인의 정보를 등록할 경우 일체의 권리를 주장할 수 없습니다.
② 당 사이트가 관계법령 및 개인정보 보호정책에 의거하여 그 책임을 지는 경우를 제외하고 회원에게 부여된
ID의 비밀번호 관리소홀, 부정사용에 의하여 발생하는 모든 결과에 대한 책임은 회원에게 있습니다.
③ 회원은 당 사이트 및 제 3자의 지적 재산권을 침해해서는 안 됩니다.
제 4 장 서비스의 이용
제 12 조 (서비스 이용 시간)
① 서비스 이용은 당 사이트의 업무상 또는 기술상 특별한 지장이 없는 한 연중무휴, 1일 24시간 운영을
원칙으로 합니다. 단, 당 사이트는 시스템 정기점검, 증설 및 교체를 위해 당 사이트가 정한 날이나 시간에
서비스를 일시 중단할 수 있으며, 예정되어 있는 작업으로 인한 서비스 일시중단은 당 사이트 홈페이지를
통해 사전에 공지합니다.
② 당 사이트는 서비스를 특정범위로 분할하여 각 범위별로 이용가능시간을 별도로 지정할 수 있습니다. 다만
이 경우 그 내용을 공지합니다.
제 13 조 (홈페이지 저작권)
① NDSL에서 제공하는 모든 저작물의 저작권은 원저작자에게 있으며, KISTI는 복제/배포/전송권을 확보하고
있습니다.
② NDSL에서 제공하는 콘텐츠를 상업적 및 기타 영리목적으로 복제/배포/전송할 경우 사전에 KISTI의 허락을
받아야 합니다.
③ NDSL에서 제공하는 콘텐츠를 보도, 비평, 교육, 연구 등을 위하여 정당한 범위 안에서 공정한 관행에
합치되게 인용할 수 있습니다.
④ NDSL에서 제공하는 콘텐츠를 무단 복제, 전송, 배포 기타 저작권법에 위반되는 방법으로 이용할 경우
저작권법 제136조에 따라 5년 이하의 징역 또는 5천만 원 이하의 벌금에 처해질 수 있습니다.
제 14 조 (유료서비스)
① 당 사이트 및 협력기관이 정한 유료서비스(원문복사 등)는 별도로 정해진 바에 따르며, 변경사항은 시행 전에
당 사이트 홈페이지를 통하여 회원에게 공지합니다.
② 유료서비스를 이용하려는 회원은 정해진 요금체계에 따라 요금을 납부해야 합니다.
제 5 장 계약 해지 및 이용 제한
제 15 조 (계약 해지)
회원이 이용계약을 해지하고자 하는 때에는 [가입해지] 메뉴를 이용해 직접 해지해야 합니다.
제 16 조 (서비스 이용제한)
① 당 사이트는 회원이 서비스 이용내용에 있어서 본 약관 제 11조 내용을 위반하거나, 다음 각 호에 해당하는
경우 서비스 이용을 제한할 수 있습니다.
- 2년 이상 서비스를 이용한 적이 없는 경우
- 기타 정상적인 서비스 운영에 방해가 될 경우
② 상기 이용제한 규정에 따라 서비스를 이용하는 회원에게 서비스 이용에 대하여 별도 공지 없이 서비스 이용의
일시정지, 이용계약 해지 할 수 있습니다.
제 17 조 (전자우편주소 수집 금지)
회원은 전자우편주소 추출기 등을 이용하여 전자우편주소를 수집 또는 제3자에게 제공할 수 없습니다.
제 6 장 손해배상 및 기타사항
제 18 조 (손해배상)
당 사이트는 무료로 제공되는 서비스와 관련하여 회원에게 어떠한 손해가 발생하더라도 당 사이트가 고의 또는 과실로 인한 손해발생을 제외하고는 이에 대하여 책임을 부담하지 아니합니다.
제 19 조 (관할 법원)
서비스 이용으로 발생한 분쟁에 대해 소송이 제기되는 경우 민사 소송법상의 관할 법원에 제기합니다.
[부 칙]
1. (시행일) 이 약관은 2016년 9월 5일부터 적용되며, 종전 약관은 본 약관으로 대체되며, 개정된 약관의 적용일 이전 가입자도 개정된 약관의 적용을 받습니다.