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Sample records for highly sensitive uplc-ms

  1. A dual role of boronate affinity in high-sensitivity detection of vicinal diol brassinosteroids from sub-gram plant tissues via UPLC-MS/MS.

    PubMed

    Xin, Peiyong; Yan, Jijun; Fan, Jinshi; Chu, Jinfang; Yan, Cunyu

    2013-03-01

    Based on the dual role of specific boronate affinity, making use of both novel self-synthesized boronate affinity-functionalized magnetic nanoparticles and a high-efficiency organic boronic acid-type derivatization reagent, we report a simple, convenient and highly-sensitive method for detection of endogenous brassinosteroids from real plant materials.

  2. A fast, sensitive, and high throughput method for the determination of cefuroxime lysine in dog plasma by UPLC-MS/MS.

    PubMed

    Zhao, Longshan; Zhao, Yunli; Li, Qing; Chen, Xiaohui; Xiao, Feng; He, Bosai; Wang, Jie; Bi, Kaishun

    2012-01-30

    In order to investigate the preclinical pharmacokinetics of cefuroxime lysine, a fast, sensitive and high throughput UPLC-ESI-MS/MS method has been developed and validated for the quantitative determination of cefuroxime in dog plasma. Cefuroxime and IS phenacetin were extracted from plasma samples by PPT or LLE procedure, and then separated on an ACQUITY UPLC™ BEH C(18) column with an isocratic elution of acetonitrile-0.1% formic acid in 10mM ammonium acetate (40:60, v/v). MRM using the fragmentation transitions of m/z 442 → 364 and 180 → 110 in positive ESI mode was performed to quantify cefuroxime and IS, respectively. The calibration curves were linear over the concentration range of 2-400 μg/ml for PPT and 0.01-5 μg/ml for LLE. The LLOQ was 0.01 μg/ml. The intra- and inter-day precisions in all samples were no more than 8.1%, while the accuracy was within ± 6.2% of nominal values. The method was successfully applied to the evaluation of pharmacokinetic parameters of cefuroxime lysine in beagle dogs.

  3. A rapid and highly sensitive UPLC-MS-MS method for the quantification of zolpidem tartrate in human EDTA plasma and its application to pharmacokinetic study.

    PubMed

    Reddy, Dendhi Chandrapal; Bapuji, Akula Tukaram; Rao, Vepakomma Suryanarayana; Himabindu, Vurimindi; Ravinder, Sreedasyam

    2012-07-01

    A rapid and high sensitive liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed and validated for the quantification of zolpidem in human EDTA plasma using ondansetron (IS) as an internal standard. The analyte and IS were extracted from human plasma using ethyl acetate and separated on a C18 column (Inertsil-ODS, 5 µm, 4.6 × 50 mm) interfaced with a triple quadrupole tandem mass spectrometer. The mobile phase, which consisted of a mixture of methanol and 20 mM ammonium formate (pH 5.00 ± 0.05; 75:25 v/v), was injected at a flow rate of 0.40 mL/min. The retention times of zolpidem and IS were approximately 1.76 and 1.22. The LC run time was 3 min. The electrospray ionization source was operated in positive ion mode. Multiple reaction monitoring used the [M + H](+) ions m/z 308.13 → 235.21 for zolpidem and m/z 294.02 → 170.09 for the ondansetron, respectively. Five freeze-thaw cycles was established at -20 and -70°C.The linearity of the response/concentration curve was established in human EDTA plasma over the concentration range 0.10-149.83 ng/mL. The lower detection limit [(signal-to-noise (S/N) > 3] was 0.04 ng/mL and the lower limit of quantification (S/N > 10) was 0.10 ng/mL. This LC-MS-MS method was validated with intra-batch and inter-batch precision of 0.52-8.66.The intra-batch and inter-batch accuracy was 96.66-106.11. Recovery of zolpidem in human plasma was 87.00% and IS recovery was 81.60%. The primary pharmacokinetic parameters were T(max) (h) = (1.25 ± 0.725), C(max) (ng/mL) (127.80 ± 34.081), AUC(0→t), = (665.37 ± 320.982) and AUC(0→∞), 686.03 ± 342.952, respectively. PMID:22689921

  4. A sensitive analytical procedure for monitoring acrylamide in environmental water samples by offline SPE-UPLC/MS/MS.

    PubMed

    Togola, Anne; Coureau, Charlotte; Guezennec, Anne-Gwenaëlle; Touzé, Solène

    2015-05-01

    The presence of acrylamide in natural systems is of concern from both environmental and health points of view. We developed an accurate and robust analytical procedure (offline solid phase extraction combined with UPLC/MS/MS) with a limit of quantification (20 ng L(-1)) compatible with toxicity threshold values. The optimized (considering the nature of extraction phases, sampling volumes, and solvent of elution) solid phase extraction (SPE) was validated according to ISO Standard ISO/IEC 17025 on groundwater, surface water, and industrial process water samples. Acrylamide is highly polar, which induces a high variability during the SPE step, therefore requiring the use of C(13)-labeled acrylamide as an internal standard to guarantee the accuracy and robustness of the method (uncertainty about 25 % (k = 2) at limit of quantification level). The specificity of the method and the stability of acrylamide were studied for these environmental media, and it was shown that the method is suitable for measuring acrylamide in environmental studies.

  5. A sensitive analytical procedure for monitoring acrylamide in environmental water samples by offline SPE-UPLC/MS/MS.

    PubMed

    Togola, Anne; Coureau, Charlotte; Guezennec, Anne-Gwenaëlle; Touzé, Solène

    2015-05-01

    The presence of acrylamide in natural systems is of concern from both environmental and health points of view. We developed an accurate and robust analytical procedure (offline solid phase extraction combined with UPLC/MS/MS) with a limit of quantification (20 ng L(-1)) compatible with toxicity threshold values. The optimized (considering the nature of extraction phases, sampling volumes, and solvent of elution) solid phase extraction (SPE) was validated according to ISO Standard ISO/IEC 17025 on groundwater, surface water, and industrial process water samples. Acrylamide is highly polar, which induces a high variability during the SPE step, therefore requiring the use of C(13)-labeled acrylamide as an internal standard to guarantee the accuracy and robustness of the method (uncertainty about 25 % (k = 2) at limit of quantification level). The specificity of the method and the stability of acrylamide were studied for these environmental media, and it was shown that the method is suitable for measuring acrylamide in environmental studies. PMID:25471720

  6. Association between Oxidative DNA Damage and Risk of Colorectal Cancer: Sensitive Determination of Urinary 8-Hydroxy-2′-deoxyguanosine by UPLC-MS/MS Analysis

    PubMed Central

    Guo, Cheng; Li, Xiaofen; Wang, Rong; Yu, Jiekai; Ye, Minfeng; Mao, Lingna; Zhang, Suzhan; Zheng, Shu

    2016-01-01

    Oxidative DNA damage plays crucial roles in the pathogenesis of numerous diseases including cancer. 8-hydroxy-2′-deoxyguanosine (8-OHdG) is the most representative product of oxidative modifications of DNA, and urinary 8-OHdG is potentially the best non-invasive biomarker of oxidative damage to DNA. Herein, we developed a sensitive, specific and accurate method for quantification of 8-OHdG in human urine. The urine samples were pretreated using off-line solid-phase extraction (SPE), followed by ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis. By the use of acetic acid as an additive to the mobile phase, we improved the UPLC-MS/MS detection of 8-OHdG by 2.7−5.3 times. Using the developed strategy, we measured the contents of 8-OHdG in urine samples from 142 healthy volunteers and 84 patients with colorectal cancer (CRC). We observed increased levels of urinary 8-OHdG in patients with CRC and patients with tumor metastasis, compared to healthy controls and patients without tumor metastasis, respectively. Additionally, logistic regression analysis and receiver operator characteristic (ROC) curve analysis were performed. Our findings implicate that oxidative stress plays important roles in the development of CRC and the marked increase of urinary 8-OHdG may serve as a potential liquid biomarker for the risk estimation, early warning and detection of CRC. PMID:27585556

  7. Association between Oxidative DNA Damage and Risk of Colorectal Cancer: Sensitive Determination of Urinary 8-Hydroxy-2‧-deoxyguanosine by UPLC-MS/MS Analysis

    NASA Astrophysics Data System (ADS)

    Guo, Cheng; Li, Xiaofen; Wang, Rong; Yu, Jiekai; Ye, Minfeng; Mao, Lingna; Zhang, Suzhan; Zheng, Shu

    2016-09-01

    Oxidative DNA damage plays crucial roles in the pathogenesis of numerous diseases including cancer. 8-hydroxy-2‧-deoxyguanosine (8-OHdG) is the most representative product of oxidative modifications of DNA, and urinary 8-OHdG is potentially the best non-invasive biomarker of oxidative damage to DNA. Herein, we developed a sensitive, specific and accurate method for quantification of 8-OHdG in human urine. The urine samples were pretreated using off-line solid-phase extraction (SPE), followed by ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis. By the use of acetic acid as an additive to the mobile phase, we improved the UPLC-MS/MS detection of 8-OHdG by 2.7‑5.3 times. Using the developed strategy, we measured the contents of 8-OHdG in urine samples from 142 healthy volunteers and 84 patients with colorectal cancer (CRC). We observed increased levels of urinary 8-OHdG in patients with CRC and patients with tumor metastasis, compared to healthy controls and patients without tumor metastasis, respectively. Additionally, logistic regression analysis and receiver operator characteristic (ROC) curve analysis were performed. Our findings implicate that oxidative stress plays important roles in the development of CRC and the marked increase of urinary 8-OHdG may serve as a potential liquid biomarker for the risk estimation, early warning and detection of CRC.

  8. Association between Oxidative DNA Damage and Risk of Colorectal Cancer: Sensitive Determination of Urinary 8-Hydroxy-2'-deoxyguanosine by UPLC-MS/MS Analysis.

    PubMed

    Guo, Cheng; Li, Xiaofen; Wang, Rong; Yu, Jiekai; Ye, Minfeng; Mao, Lingna; Zhang, Suzhan; Zheng, Shu

    2016-01-01

    Oxidative DNA damage plays crucial roles in the pathogenesis of numerous diseases including cancer. 8-hydroxy-2'-deoxyguanosine (8-OHdG) is the most representative product of oxidative modifications of DNA, and urinary 8-OHdG is potentially the best non-invasive biomarker of oxidative damage to DNA. Herein, we developed a sensitive, specific and accurate method for quantification of 8-OHdG in human urine. The urine samples were pretreated using off-line solid-phase extraction (SPE), followed by ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis. By the use of acetic acid as an additive to the mobile phase, we improved the UPLC-MS/MS detection of 8-OHdG by 2.7-5.3 times. Using the developed strategy, we measured the contents of 8-OHdG in urine samples from 142 healthy volunteers and 84 patients with colorectal cancer (CRC). We observed increased levels of urinary 8-OHdG in patients with CRC and patients with tumor metastasis, compared to healthy controls and patients without tumor metastasis, respectively. Additionally, logistic regression analysis and receiver operator characteristic (ROC) curve analysis were performed. Our findings implicate that oxidative stress plays important roles in the development of CRC and the marked increase of urinary 8-OHdG may serve as a potential liquid biomarker for the risk estimation, early warning and detection of CRC. PMID:27585556

  9. A Simple and High-Throughput Analysis of Amatoxins and Phallotoxins in Human Plasma, Serum and Urine Using UPLC-MS/MS Combined with PRiME HLB μElution Platform.

    PubMed

    Zhang, Shuo; Zhao, Yunfeng; Li, Haijiao; Zhou, Shuang; Chen, Dawei; Zhang, Yizhe; Yao, Qunmei; Sun, Chengye

    2016-01-01

    Amatoxins and phallotoxins are toxic cyclopeptides found in the genus Amanita and are among the predominant causes of fatal food poisoning in China. In the treatment of Amanita mushroom poisoning, an early and definite diagnosis is necessary for a successful outcome, which has prompted the development of protocols for the fast and confirmatory determination of amatoxins and phallotoxins in human biological fluids. For this purpose, a simple, rapid and sensitive multiresidue UPLC-MS/MS method for the simultaneous determination of α-amanitin, β-amanitin, γ-amanitin, phalloidin (PHD) and phallacidin (PCD) in human plasma, serum and urine was developed and validated. The diluted plasma, serum and urine samples were directly purified with a novel PRiME technique on a 96-well μElution plate platform, which allowed high-throughput sample processing and low reagent consumption. After purification, a UPLC-MS/MS analysis was performed using positive electrospray ionization (ESI+) in multiple reaction monitoring (MRM) mode. This method fulfilled the requirements of a validation test, with good results for the limit of detection (LOD), lower limit of quantification (LLOQ), accuracy, intra- and inter-assay precision, recovery and matrix effects. All of the analytes were confirmed and quantified in authentic plasma, serum and urine samples obtained from cases of poisoning using this method. Using the PRiME μElution technique for quantification reduces labor and time costs and represents a suitable method for routine toxicological and clinical emergency analysis. PMID:27153089

  10. A Simple and High-Throughput Analysis of Amatoxins and Phallotoxins in Human Plasma, Serum and Urine Using UPLC-MS/MS Combined with PRiME HLB μElution Platform

    PubMed Central

    Zhang, Shuo; Zhao, Yunfeng; Li, Haijiao; Zhou, Shuang; Chen, Dawei; Zhang, Yizhe; Yao, Qunmei; Sun, Chengye

    2016-01-01

    Amatoxins and phallotoxins are toxic cyclopeptides found in the genus Amanita and are among the predominant causes of fatal food poisoning in China. In the treatment of Amanita mushroom poisoning, an early and definite diagnosis is necessary for a successful outcome, which has prompted the development of protocols for the fast and confirmatory determination of amatoxins and phallotoxins in human biological fluids. For this purpose, a simple, rapid and sensitive multiresidue UPLC-MS/MS method for the simultaneous determination of α-amanitin, β-amanitin, γ-amanitin, phalloidin (PHD) and phallacidin (PCD) in human plasma, serum and urine was developed and validated. The diluted plasma, serum and urine samples were directly purified with a novel PRiME technique on a 96-well μElution plate platform, which allowed high-throughput sample processing and low reagent consumption. After purification, a UPLC-MS/MS analysis was performed using positive electrospray ionization (ESI+) in multiple reaction monitoring (MRM) mode. This method fulfilled the requirements of a validation test, with good results for the limit of detection (LOD), lower limit of quantification (LLOQ), accuracy, intra- and inter-assay precision, recovery and matrix effects. All of the analytes were confirmed and quantified in authentic plasma, serum and urine samples obtained from cases of poisoning using this method. Using the PRiME μElution technique for quantification reduces labor and time costs and represents a suitable method for routine toxicological and clinical emergency analysis. PMID:27153089

  11. High-Throughput UPLC-MS Method for the Determination of N-Acetyl-l-Cysteine: Application in Tissue Distribution Study in Wistar Rats.

    PubMed

    Siddiqui, Masoom Raza; Wabaidur, Saikh Mohammad; Ola, Mohammad Shamsul; AlOthman, Zeid A; Rafiquee, Mohammad Zulfiqar Ali; Khan, Moonis Ali

    2016-08-01

    N-Acetylcysteine (NAC) is the N-acetyl derivative of the amino acid l-cysteine and is extensively used as a medicine to treat a variety of diseases. High-throughput ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS) method has been developed for the quantitative assessment of N-acetyl-l-cysteine. The method was further applied to study the distribution of the intraperitoneal injected drug into different tissues and plasma of Wistar rats, including liver, kidney, heart, lungs and spleen. The drug was having highest concentration in plasma and liver followed by kidney, lungs, heart and spleen. Method validation studies suggested being linear in the range of 1-15 µg mL(-1) for liver, kidney, heart, lungs and spleen and 1-120 µg mL(-1) for the plasma. The limit of detection and limit of quantitation were found to be 0.20 and 0.66 µg mL(-1), respectively. The recovery studies suggested that in all the cases, the obtained recovery was in the range of 98.51-101.88%. Our analyses provide a validated UPLC-MS method for the determination of NAC and its successful application for the analysis in plasma and tissues obtained from Wistar rats. PMID:27102930

  12. SPE-UPLC-MS/MS method for sensitive and rapid determination of aripiprazole in human plasma to support a bioequivalence study.

    PubMed

    Patel, Daxesh P; Sharma, Primal; Sanyal, Mallika; Shrivastav, Pranav S

    2013-04-15

    An improved and rugged UPLC-MS/MS method has been developed and validated for sensitive and rapid determination of aripiprazole in human plasma using aripiprazole-d8 as the internal standard (IS). The analyte and IS were extracted from 100 μL of human plasma by solid-phase extraction using Phenomenex Strata-X (30 mg, 1 cc) cartridges. Chromatography was achieved on an Acquity UPLC BEH C18 (50 mm × 2.1 mm, 1.7 μm) analytical column using methanol: 10mM ammonium formate (85:15, v/v) as the mobile phase with isocratic elution. Quantitation was done using multiple reaction monitoring in the positive ionization mode. The linearity of the method was established in the concentration range 0.05-80 ng/mL. The mean extraction recovery was greater than 96% across QC levels, while intra- and inter batch accuracy and precision (% CV) values ranged from 97.4 to 101.9% and from 1.20 to 3.72% respectively. The relative matrix effect in eight different lots of plasma samples, expressed as % CV for the calculated slopes of calibration curves was 1.08%. The stability of aripiprazole was studied under different storage conditions. The validated method was used to support a bioequivalence study of 10mg aripiprazole formulation in 36 healthy Indian subjects. PMID:23510852

  13. Development and validation of sensitive and rapid UPLC-MS/MS method for quantitative determination of daclatasvir in human plasma: Application to a bioequivalence study.

    PubMed

    Rezk, Mamdouh R; Bendas, Ehab R; Basalious, Emad B; Karim, Iman A

    2016-09-01

    A rapid and sensitive UPLC-MS/MS method was developed and validated for determination of daclatasvir (DAC) in human plasma using sofosbuvir (SOF) as an internal standard (IS). The Xevo TQD LC-MS/MS was operated under the multiple-reaction monitoring mode using electrospray ionization. Precipitation with acetonitrile was used in sample preparation. The prepared samples were chromatographed on Acquity UPLC HSS C18 (50×2.1mm, 1.8μm) column by pumping 10mM ammonium formate (pH 3.5) and acetonitrile in an isocratic mode at a flow rate of 0.30ml/min. Method validation was performed as per the FDA guidelines and the standard curves were found to be linear in the range of 5-4000ng/ml for DAC. The intra-day and inter-day precision and accuracy results were within the acceptable limits. A very short run time of 1.2min made it possible to analyze more than 500 human plasma samples per day. The wider range of quantification of DAC allowed the applicability of the developed method for its determination in a bioequivalence study in human volunteers. PMID:27232152

  14. Development and validation of a selective, sensitive and stability indicating UPLC-MS/MS method for rapid, simultaneous determination of six process related impurities in darunavir drug substance.

    PubMed

    A, Vijaya Bhaskar Reddy; Yusop, Zulkifli; Jaafar, Jafariah; Aris, Azmi B; Majid, Zaiton A; Umar, Khalid; Talib, Juhaizah

    2016-09-01

    In this study a sensitive and selective gradient reverse phase UPLC-MS/MS method was developed for the simultaneous determination of six process related impurities viz., Imp-I, Imp-II, Imp-III, Imp-IV, Imp-V and Imp-VI in darunavir. The chromatographic separation was performed on Acquity UPLC BEH C18 (50 mm×2.1mm, 1.7μm) column using gradient elution of acetonitrile-methanol (80:20, v/v) and 5.0mM ammonium acetate containing 0.01% formic acid at a flow rate of 0.4mL/min. Both negative and positive electrospray ionization (ESI) modes were operated simultaneously using multiple reaction monitoring (MRM) for the quantification of all six impurities in darunavir. The developed method was fully validated following ICH guidelines with respect to specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, precision, robustness and sample solution stability. The method was able to quantitate Imp-I, Imp-IV, Imp-V at 0.3ppm and Imp-II, Imp-III, and Imp-VI at 0.2ppm with respect to 5.0mg/mL of darunavir. The calibration curves showed good linearity over the concentration range of LOQ to 250% for all six impurities. The correlation coefficient obtained was >0.9989 in all the cases. The accuracy of the method lies between 89.90% and 104.60% for all six impurities. Finally, the method has been successfully applied for three formulation batches of darunavir to determine the above mentioned impurities, however no impurity was found beyond the LOQ. This method is a good quality control tool for the trace level quantification of six process related impurities in darunavir during its synthesis.

  15. A selective and sensitive method based on UPLC-MS/MS for quantification of momordin Ic in rat plasma: application to a pharmacokinetic study.

    PubMed

    Yan, Huiyu; Song, Yanqing; Zhou, Wei; Zhang, Sixi

    2015-11-10

    A selective and sensitive method was developed and validated based on ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). This method was applied to quantify momordin Ic in rat plasma. Chromatographic separation was performed on a Hypersil GOLD HPLC C18 column (150mm×4.6mm, 5μm) using an isocratic mobile phase of acetonitrile/water (80:20, v/v) at a flow rate of 0.6mL/min. An electrospray ionization source was applied and operated in negative ion mode; selected reaction monitoring (SRM) mode was used for quantification by monitoring the precursor-to-product ion transitions of m/z 763.4→m/z 455.3 for momordin Ic, and m/z 649.4→m/z 487.3 for IS. Calibration curves showed good linearity over the range of 22.0-2200ng/mL for momordin Ic in rat plasma. The developed method was applied to a pharmacokinetic study of momordin Ic in rats after single intravenous doses at 0.52, 1.56, and 4.67mg/kg. The elimination half-life (t1/2) values were 1.22±0.39, 1.14±0.10, and 1.83±0.39h, respectively. The plasma concentration at 2min (C2min) and area under the curve (AUC) for the intravenous doses of momordin Ic were approximately dose proportional. PMID:26218506

  16. High-throughput screening of inhibitory effects of Bo-yang-hwan-o-tang on human cytochrome P450 isoforms in vitro using UPLC/MS/MS.

    PubMed

    Lee, Miran; Park, Jeonghyeon; Lim, Mi-sun; Seong, Sook Jin; Lee, Joomi; Seo, Jeong Ju; Park, Yong-Ki; Lee, Hae Won; Yoon, Young-Ran

    2012-01-01

    Bo-yang-hwan-o-tang (BHT) is an oriental herbal medicine for treating brain disorders such as cerebral ischemia. The objective of this study was to develop an economically feasible and time-saving high-throughput screening method to monitor the potential inhibitory effects of BHT on human cytochrome P450 (CYP) enzymes in vitro. Two cocktail sets were used for incubation of human liver microsomes: Cocktail A: 6 probe substrates for CYP1A2, CYP2A6, CYP2C8, CYP2C19, CYP2D6, CYP3A4; Cocktail B: 3 for CYP2B6, CYP2C9, CYP2E1. The concentrations of the substrate metabolites were simultaneously analyzed using UPLC/MS/MS. The BHT extract had almost negligible inhibitory effects on the nine human CYP isoforms tested, with the half-maximal inhibitory concentration value ranged from 3624.99 to 45412.44 μg/ml. The results suggest that BHT extract has no inhibitory effects on CYP isoforms within the clinically recommended dosage range. We conclude that BHT might be free of drug-herb interactions when co-administered with other medicines. However, more in vivo human studies are needed to confirm these results. The high-throughput screening method can be a useful tool for drug discovery and for understanding drug interactions. PMID:23232241

  17. UPLC-MS(E) application in disease biomarker discovery: the discoveries in proteomics to metabolomics.

    PubMed

    Zhao, Ying-Yong; Lin, Rui-Chao

    2014-05-25

    In the last decade, proteomics and metabolomics have contributed substantially to our understanding of different diseases. Proteomics and metabolomics aims to comprehensively identify proteins and metabolites to gain insight into the cellular signaling pathways underlying disease and to discover novel biomarkers for screening, early detection and diagnosis, as well as for determining prognoses and predicting responses to specific treatments. For comprehensive analysis of cellular proteins and metabolites, analytical methods of wider dynamic range higher resolution and good sensitivity are required. Ultra performance liquid chromatography-mass spectrometry(Elevated Energy) (UPLC-MS(E)) is currently one of the most versatile techniques. UPLC-MS(E) is an established technology in proteomics studies and is now expanding into metabolite research. MS(E) was used for simultaneous acquisition of precursor ion information and fragment ion data at low and high collision energy in one analytical run, providing similar information to conventional MS(2). In this review, UPLC-MS(E) application in proteomics and metabolomics was highlighted to assess protein and metabolite changes in different diseases, including cancer, neuropsychiatric pharmacology studies from clinical trials and animal models. In addition, the future prospects for complete proteomics and metabolomics are discussed.

  18. Determination of caramel colorants' by-products in liquid foods by ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS).

    PubMed

    Goscinny, Séverine; Hanot, Vincent; Trabelsi, Hasna; Van Loco, Joris

    2014-01-01

    2-Methylimidazole, 4-methylimidazole (2-MI and 4-MI), 2-acetyl-4-(1,2,3,4-tetrahydroxybutyl) imidazole (THI) and 5-hydroxymethylfurfural (5-HMF) are neo-formed compounds generated during the manufacture of caramel colours and are transferred to the processed food. These contaminants are known to have a toxicological profile that may pose health risks. Hence, to characterise THI, 2- and 4-MI and 5-HMF levels in liquid foods, an ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and sample preparation was divided into two analytical strategies depending on the concentration range expected in the type of foods targeted. For the determination of the imidazole substitutes (THI, 2- and 4-MI), a sample enrichment and clean-up step by strong cation solid-phase extraction was developed. This method is capable of quantifying over a range of 5 ng ml⁻¹ (LOQ) to 500 ng ml⁻¹ with recoveries of 75.4-112.4% and RSDs of 1.5-15%. For determination of 5-HMF, a standard addition method was applied covering the linear range of 0.25-30 µg ml⁻¹ with RSDs from 2.8% (for intraday precision) to 9.2% (for intermediate precision). The validated analytical methods were applied to 28 liquid food samples purchased from local markets. THI was found only in the beer samples at levels up to 141.2 ng ml⁻¹. For 2-MI, non-quantifiable traces were observed for all samples, while 4-MI was observed in all samples with large concentration variations (from < LOQ to 563.9 ng ml⁻¹). 5-HMF was found at expected concentrations, except for a sherry vinegar sample (113 µg ml⁻¹), which required a high level of dilution before following the standard addition protocol.

  19. [Simultaneous determination of 11 mycotoxins in malt by isotope internal standard-UPLC-MS/MS].

    PubMed

    Wang, Sha; Kong, Wei-jun; Yang, Mei-hua

    2016-01-01

    A suitable ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of 11 mycotoxins with isotope internal standard in malt. The mycotoxins in malt were extracted and purified by one-step ultrasonic extraction procedure using acetonitrile/water/acetic acid (80 : 19 : 1), and then detected and confirmed by UPLC-MS/MS, and quantified by isotope labeled AFB1 ([13C17]-AFB1) and ZEN ([13C18]-ZEN) internal standards. Rapid separation of the 11 mycotoxins was successfully achieved on a Phenomenex Kinetex C18 column (100 mm x 2.1 mm, 2.6 μm) with gradient elution using the mobile phase of methanol containing 0.1% formic acid and 2 mmol x L(-1) ammonium acetate in water. Simultaneous acquisition was performed in multiple reaction monitoring (MRM) mode with electrospray ionization (ESI) source operated in both positive and negative ionization modes. The established method provided a good linearity for the 11 mycotoxins within their respective linear ranges with correlation coefficients all higher than 0.999 1. The average recoveries ranged from 75.0% to 117.0% with relative standard deviations (RSDs) below 5.1%. The limits of detection (LODs) and quantitation (LOQs) ranged from 0.05 to 30 μg x kg(-1) and 0.15 to 87.5 μg x kg(-1), respectively, which were below the maximum residue levels (MRLs) set by the European Union. Twenty malt samples were analyzed and nine samples were detected with mycotoxins, which were confirmed according to the same fragment ions found in positive samples and the standards at the same retention time. This study has demonstrated that the one-step extraction procedure of mycotoxins from complex matrices coupled to UPLC-MS/MS method is simple, quick, accurate and sensitive for quantitative and qualitative analysis of multiple mycotoxins in malt. PMID:27405171

  20. [Simultaneous determination of 11 mycotoxins in malt by isotope internal standard-UPLC-MS/MS].

    PubMed

    Wang, Sha; Kong, Wei-jun; Yang, Mei-hua

    2016-01-01

    A suitable ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of 11 mycotoxins with isotope internal standard in malt. The mycotoxins in malt were extracted and purified by one-step ultrasonic extraction procedure using acetonitrile/water/acetic acid (80 : 19 : 1), and then detected and confirmed by UPLC-MS/MS, and quantified by isotope labeled AFB1 ([13C17]-AFB1) and ZEN ([13C18]-ZEN) internal standards. Rapid separation of the 11 mycotoxins was successfully achieved on a Phenomenex Kinetex C18 column (100 mm x 2.1 mm, 2.6 μm) with gradient elution using the mobile phase of methanol containing 0.1% formic acid and 2 mmol x L(-1) ammonium acetate in water. Simultaneous acquisition was performed in multiple reaction monitoring (MRM) mode with electrospray ionization (ESI) source operated in both positive and negative ionization modes. The established method provided a good linearity for the 11 mycotoxins within their respective linear ranges with correlation coefficients all higher than 0.999 1. The average recoveries ranged from 75.0% to 117.0% with relative standard deviations (RSDs) below 5.1%. The limits of detection (LODs) and quantitation (LOQs) ranged from 0.05 to 30 μg x kg(-1) and 0.15 to 87.5 μg x kg(-1), respectively, which were below the maximum residue levels (MRLs) set by the European Union. Twenty malt samples were analyzed and nine samples were detected with mycotoxins, which were confirmed according to the same fragment ions found in positive samples and the standards at the same retention time. This study has demonstrated that the one-step extraction procedure of mycotoxins from complex matrices coupled to UPLC-MS/MS method is simple, quick, accurate and sensitive for quantitative and qualitative analysis of multiple mycotoxins in malt.

  1. Development and validation of a sensitive UPLC-MS/MS method for the analysis of narcotic analgesics in urine and whole blood in forensic context.

    PubMed

    Verplaetse, Ruth; Tytgat, Jan

    2012-02-10

    Narcotic analgesics are widely (ab) used and sometimes only occur in low concentrations in biological samples. Therefore, a highly sensitive liquid chromatography tandem mass spectrometry method was developed for simultaneous analysis of 9 narcotic analgesics and metabolites (buprenorphine, O-desmethyltramadol, fentanyl, norbuprenorphine, norfentanyl, pethidine, piritramide, tilidine and tramadol) in urine and whole blood. Sample preparation was performed on a mixed-mode cation exchange solid phase extraction cartridge with an additional alkaline wash step to decrease matrix effects and thus increase sensitivity. Ionization with electrospray ionization was found to be more efficient than atmospheric pressure chemical ionization. The use of a mobile phase of high pH resulted in higher electrospray ionization signals than the conventional low pH mobile phases. In the final method, gradient elution with 10mM ammonium bicarbonate (pH 9) and methanol was performed on a small particle column (Acquity C18, 1.7 μm, 2.1 mm × 50 mm). Selectivity, matrix effects, recovery, linearity, sensitivity, precision, accuracy and stability were validated in urine and whole blood. All parameters were successfully evaluated and the method showed very high sensitivity, which was the major aim of this study. The applicability of the method was demonstrated by analysis of several forensic cases involving narcotic analgesics. PMID:21356580

  2. Development and validation of a simple and sensitive method for quantification of levodopa and carbidopa in rat and monkey plasma using derivatization and UPLC-MS/MS.

    PubMed

    Junnotula, Venkatraman; Licea-Perez, Hermes

    2013-05-01

    A simple, selective, and sensitive quantitative method has been developed for the simultaneous determination of levodopa and carbidopa in rat and monkey plasma by protein precipitation using acetonitrile containing the derivatizing reagent, flourescamine. Derivatized products of levodopa and carbidopa were separated on a BEH C18 column (2.1 mm × 50 mm; 1.7 μm particle size) using ultra high performance liquid chromatography (UHPLC) without any further purification. Tandem mass spectrometry (MS/MS) was used for detection. The method was validated over the concentration range of 5-5000 ng/mL and 3-3000 ng/mL for levodopa and carbidopa, respectively in rat and monkey plasma. Due to the poor stability of the investigated analytes in biological matrices, a mixture of sodium metabisulfite and hydrazine dihydrochloride was used as a stabilizer. This method was successfully utilized to support pharmacokinetic studies in both species. The results from assay validations and incurred samples re-analysis show that the method is selective, sensitive and robust. To our knowledge, this is the first UHPLC-MS/MS based method that utilizes derivatization with fluorescamine and provides adequate sensitivity for both levodopa and carbidopa with 50 μL of sample and a run time of 3.5 min.

  3. Development and Validation of an UPLC-MS/MS Method for Simultaneous Determination of Ibuprofen and Promethazine in Tablets Stored on Board the International Space Station

    NASA Technical Reports Server (NTRS)

    Wu, L.; Chow, D. S.-L.; Daniels, V. R.

    2016-01-01

    Therapeutic efficacy and safety of pharmaceuticals remain a critical issue for successful NASA medical operations of long-term space missions on International Space Station (ISS). Medications stored aboard the ISS are subjected to unique environmental factors for extended time periods that may cause physicochemical degradation or alterations in the integrity of formulations that include the active pharmaceutical ingredient (API) and the chemical matrix of the formulation. Degradation of API and adjuvants, in addition to alterations of the chemical matrix of the formulation, can decrease potency and bioavailability and increase the risk due to toxicity of degraded medications. UPLC-MS/MS analysis is efficient and highly sensitive to quantify API content and MS analysis enables the elucidation of the structures of degradation products for each formulation. Therefore the aim of this project was to develop and validate a rapid, specific, and sensitive UPLC-MS/MS assay for the simultaneous determination of ibuprofen and promethazine in tablets stored aboard the ISS.

  4. A sensitive and selective UPLC-MS/MS method for simultaneous determination of 10 alkaloids from Rhizoma Menispermi in rat plasma and its application to a pharmacokinetic study.

    PubMed

    Wei, Jinxia; Fang, Linlin; Liang, Xinlei; Su, Dan; Guo, Xingjie

    2015-11-01

    A sensitive and selective liquid chromatography-tandem mass spectrometry method has been developed and validated for simultaneous quantitation of 10 alkaloids (dauricine, daurisoline, N-desmethyldauricine, dauricicoline, dauriporphinoline, bianfugecine, dauricoside, stepholidine, acutumine and acutumidine) from Rhizoma Menispermi in rat plasma. After addition of internal standard (verapamil), plasma samples were pretreated by a single-step protein precipitation with acetonitrile. Chromatographic separation was performed on a Waters BEH C18 column with gradient elution using a mobile phase composed of acetonitrile and water (containing 0.1% formic acid) at a flow rate of 0.3 mL/min. The analytes were detected without interference in the multiple reaction monitoring (MRM) mode with positive electrospray ionization. The validated method exhibited good linearity over a wide concentration range (r≥0.9914), and the lower limits of quantification were 0.01-5.0 ng/mL for all the analytes. The intra-day and inter-day precisions (RSD) at three different levels were both less than 13.4% and the accuracies (RE) ranged from -12.8% to 13.5%. The mean extraction recoveries of analytes and IS from rat plasma were all more than 77%. The validated method was successfully applied to a comparative pharmacokinetic study of 10 alkaloids in rat plasma after oral administration of Rhizoma Menispermi extract.

  5. Determination of Pinaverium Bromide in Human Plasma by a Sensitive and Robust UPLC-MS-MS Method and Application to a Pharmacokinetic Study in Mexican Subjects.

    PubMed

    Patiño-Rodríguez, Omar; Zapata-Morales, Juan Ramón; Escobedo-Moratilla, Abraham; Díaz de León-Cabrero, Manuel; Torres-Roque, Irma; Pérez-Urizar, José

    2015-09-01

    A high-throughput ultra-performance liquid chromatography coupled to tandem mass spectrometry (LC-ESI-MS-MS) method was developed for the determination of pinaverium bromide in human plasma. Protein precipitation with acetonitrile was used to extract pinaverium and itraconazole (as internal standard) from 500 µL plasma samples. The chromatographic separation was achieved with an Acquity UPLC BEH C18 column (1.7 µm, 2.1 × 100 mm) using a mixture of acetonitrile-5 mM ammonium formate (80:20, v/v) as mobile phase. Isocratic elution at 0.3 mL/min was used. Detection was performed by positive ion electrospray tandem mass spectrometry on a XEVO TQ-S by multiple reaction monitoring mode. The mass transitions monitorized were as follows: m/z 511.2 → 230 for pinaverium bromide, and m/z 705.29 → 392.18 for the itraconazole. The method was validated over a concentration range of 12-12,000 pg/mL. The chromatographic method runtime is 2.5 min and was applied to characterize the pharmacokinetics of pinaverium bromide after the oral administration of 100 mg to healthy Mexican subjects. PMID:25862744

  6. Determination of Pinaverium Bromide in Human Plasma by a Sensitive and Robust UPLC-MS-MS Method and Application to a Pharmacokinetic Study in Mexican Subjects.

    PubMed

    Patiño-Rodríguez, Omar; Zapata-Morales, Juan Ramón; Escobedo-Moratilla, Abraham; Díaz de León-Cabrero, Manuel; Torres-Roque, Irma; Pérez-Urizar, José

    2015-09-01

    A high-throughput ultra-performance liquid chromatography coupled to tandem mass spectrometry (LC-ESI-MS-MS) method was developed for the determination of pinaverium bromide in human plasma. Protein precipitation with acetonitrile was used to extract pinaverium and itraconazole (as internal standard) from 500 µL plasma samples. The chromatographic separation was achieved with an Acquity UPLC BEH C18 column (1.7 µm, 2.1 × 100 mm) using a mixture of acetonitrile-5 mM ammonium formate (80:20, v/v) as mobile phase. Isocratic elution at 0.3 mL/min was used. Detection was performed by positive ion electrospray tandem mass spectrometry on a XEVO TQ-S by multiple reaction monitoring mode. The mass transitions monitorized were as follows: m/z 511.2 → 230 for pinaverium bromide, and m/z 705.29 → 392.18 for the itraconazole. The method was validated over a concentration range of 12-12,000 pg/mL. The chromatographic method runtime is 2.5 min and was applied to characterize the pharmacokinetics of pinaverium bromide after the oral administration of 100 mg to healthy Mexican subjects.

  7. Depletion of urinary zilpaterol residues in horses as measured by ELISA and UPLC-MS/MS.

    PubMed

    Shelver, Weilin L; Thorson, Jennifer F; Hammer, Carolyn J; Smith, David J

    2010-04-14

    Three horses were dosed with dietary zilpaterol and the urine concentrations measured from withdrawal day 0 to withdrawal day 21. The analyses were carried out using both enzyme-linked immunosorbent assay (ELISA) and an ultraperformance liquid chromatography with triple-quadrupole-tandem mass spectrometric detection (UPLC-MS/MS). The UPLC-MS/MS method was developed to provide rapid analysis with positive analyte identification by following three product ions and computing the two independent ion ratios. When urinary zilpaterol concentrations were between 0.2 and 2 ng/mL, the ELISA had interday recoveries of 114-120% with coefficients of variation (CV) of <22%; intraday recoveries were 79-111% with CVs of <13%. For urinary zilpaterol concentrations of 0.4-40 ng/mL the UPLC-MS/MS method had interday recoveries of 94-104% with CVs of <8%; intraday recoveries were 97-102% with CVs of < or = 7.5%. Correlation analysis demonstrated that the ELISA and UPLC-MS/MS methods returned essentially the same results, especially at urinary zilpaterol concentrations below 2000 ng/mL. Urinary excretion peaked rapidly after dosing between 5300 and 10800 ng/mL (UPLC-MS/MS) or between 5900 and 17900 ng/mL (ELISA) for the different horses, much higher than observed in other species. Urinary zilpaterol concentrations declined rapidly to below 3000 ng/mL within 24 h of study day 1. After about 5 days, zilpaterol elimination slowed markedly, taking nearly 10 days for an order of magnitude decrease. The analytical methods were able to detect zilpaterol in the urine even at withdrawal day 21, demonstrating the sensitivity of each analytical method and the slow rate of zilpaterol depuration from horses.

  8. Screening β1AR inhibitors by cell membrane chromatography and offline UPLC/MS method for protecting myocardial ischemia.

    PubMed

    Yue, Yuan; Dou, Lili; Wang, Xin; Xue, Hui; Song, Yanhong; Li, Xiaoni

    2015-11-10

    A high expression β1AR/cell membrane chromatography (β1AR-CMC) and offline UPLC/MS method has been developed for screening active ingredients from Coptis chinensis. In this study, the fractions retained by CMC column were separated and identified by UPLC/MS system. Using metoprolol as a positive control drug, coptisine from C. chinensis was identified as the active component which could inhibit β1AR. Compared with the control group: coptisine could attenuate the infarct size and release malondialdehyde (MDA) while increasing superoxide dismutase (SOD) activity, suggesting a role in reducing myocardial injury. In vitro, coptisine could decrease apoptosis, showing their protective effects upon cardiomyocytes. This β1AR-CMC-offline-UPLC/MS method can be applied for screening active components acting on β1AR from traditional Chinese medicines. PMID:26263062

  9. Determination of sotolon content in South African white wines by two novel HPLC-UV and UPLC-MS methods.

    PubMed

    Gabrielli, Mario; Buica, Astrid; Fracassetti, Daniela; Stander, Marietjie; Tirelli, Antonio; du Toit, Wessel J

    2015-02-15

    Sotolon has been reported to play an important role in the atypical ageing and aroma character of many wines. A number of analytical techniques for sotolon analysis in wine have been reported, but these often require extensive sample preparation. In this work we report a HPLC-UV method and a novel UPLC-MS method to determine sotolon concentrations in white wines with little sample preparation applied for the first time for the evaluation of sotolon levels in South African wines. The validation showed that the instrumental methods had good accuracy, repeatability and linearity, but the UPLC-MS method proved more sensitive. For both methods, quantification limits were lower than the sotolon odour threshold in wine (10μg/L), 0.86μg/L and 0.013μg/L, for HPLC-UV and UPLC-MS methods, respectively. Sotolon levels in 65 South African white wines were often found to be lower than the reported odour threshold, with the highest concentration being 9.11μg/L. However, for low levels (<1μg/L), unknown interferences in certain wines led to sotolon not being quantified with the HPLC-UV method, which made the UPLC-MS method more suitable.

  10. Pharmacokinetic and bioavailability study of angeloylgomisin H in rat plasma by UPLC-MS/MS.

    PubMed

    Chen, Shanjiang; Jia, Zhuyin; Dong, Ledan; Geng, Peiwu; Liu, Zezheng; Yang, Suping; Wen, Congcong; Liu, Fuli

    2015-01-01

    Angeloylgomisin H, as a major lignin in the fruits, was reported to have the potential to improve insulin-stimulated glucose uptake by activating PPAR-γ. In this work, a sensitive and selective UPLC-MS/MS method for determination of angeloylgomisin H in rat plasma is developed. After addition of rutin as an internal standard (IS), protein precipitation by acetonitrile was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH C18 column (2.1 mm × 100 mm, 1.7 μm) with 0.1% formic acid and acetonitrile as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reactions monitoring (MRM) mode was used for quantification using target fragment ions m/z 523.2-315.1 for angeloylgomisin H, and m/z 611.1-303.1 for IS. Calibration plots were linear throughout the range 5-2000 ng/mL for angeloylgomisin H in rat plasma. Mean recoveries of angeloylgomisin H in rat plasma ranged from 86.2% to 92.5%. RSD of intra-day and inter-day precision were both < 11%. The accuracy of the method was between 93.0% and 104.1%. The method was successfully applied to pharmacokinetic study of angeloylgomisin H after either oral or intravenous administration. The absolute bioavailability of angeloylgomisin H was reported as high as 4.9%.

  11. Determination of buprenorphine, fentanyl and LSD in whole blood by UPLC-MS-MS.

    PubMed

    Berg, Thomas; Jørgenrud, Benedicte; Strand, Dag Helge

    2013-04-01

    A sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method has been developed and validated for the quantification of buprenorphine, fentanyl and lysergic acid diethylamide (LSD) in whole blood. Sample preparation was performed by liquid-liquid extraction (LLE) with methyl tert-butyl ether. UPLC-MS-MS analysis was performed with a mobile phase consisting of ammonium formate (pH 10.2) and methanol. Positive electrospray ionization MS-MS detection was performed with two multiple reaction monitoring transitions for each of the analytes and the deuterium labeled internal standards. Limit of detection values of buprenorphine, fentanyl and LSD were 0.28, 0.044 and 0.0097 ng/mL and limit of quantification values were 0.94, 0.14 and 0.036 ng/mL, respectively. Most phospholipids were removed during LLE. No or only minor matrix effects were observed. The method has been routinely used at the Norwegian Institute of Public Health since September 2011 for qualitative and quantitative detections of buprenorphine, fentanyl and/or LSD in more than 400 whole blood samples with two replicates per sample.

  12. Development and validation of an UPLC-MS/MS method for the quantification of tamoxifen and its main metabolites in human scalp hair.

    PubMed

    Drooger, Jan C; Jager, Agnes; Lam, Mei-Ho; den Boer, Mathilda D; Sleijfer, Stefan; Mathijssen, Ron H J; de Bruijn, Peter

    2015-10-10

    The aim of this study was to validate an earlier developed high-performance highly sensitive ultra performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method for quantification of tamoxifen and its three main metabolites (N-desmethyl-tamoxifen, 4-hydroxy-tamoxifen and 4-hydroxy-N-desmethyl-tamoxifen) in scalp hair. This non-invasive method might, by segmental analysis of hair, be useful in the determination of the concentration of drugs and its metabolites over time, which can be used to study a wide variety of clinical relevant questions. Hair samples (150-300 hair strands, cut as close to the scalp as possible from the posterior vertex region of the head) were collected from female patients taking tamoxifen 20mg daily (n=19). The analytes were extracted using a liquid-liquid extraction procedure with carbonate buffer at pH 8.8 and a mixture of n-hexane/isopropranol method, followed by UPLC-MS/MS chromatography, based on an earlier validated method. The calibration curves were linear in the range of 1.00-200 pmol for tamoxifen and N-desmethyl-tamoxifen, with lower limit of quantitation of 1.00 pmol and 0.100-20.0 pmol with lower limit of quantitation of 0.100 pmol for endoxifen and 4-hydroxy-tamoxifen. Assay performance was fair with a within-run and between-run variability less than 9.24 at the three quality control samples and less than 15.7 for the lower limit of quantitation. Importantly, a steep linear decline was observed from distal to proximal hair segments. Probably, this is due to UV exposure as we showed degradation of tamoxifen and its metabolites after exposure to UV-light. Furthermore, higher concentrations of tamoxifen were found in black hair samples compared to blond and brown hair samples. We conclude that measurement of the concentration of tamoxifen and its main metabolites in hair is possible, with the selective, sensitive, accurate and precise UPLC-MS/MS method. However, for tamoxifen, it seems not possible to determine

  13. Coumarin and furanocoumarin quantitation in citrus peel via ultraperformance liquid chromatography coupled with mass spectrometry (UPLC-MS).

    PubMed

    Dugrand, Audray; Olry, Alexandre; Duval, Thibault; Hehn, Alain; Froelicher, Yann; Bourgaud, Frédéric

    2013-11-13

    Coumarins and furanocoumarins are secondary metabolites commonly found in citrus plants. These molecules are allelochemical compounds in plants that have controversial effects on humans, such as phototoxicity and the commonly described interactions with drugs, referred to as the "grapefruit juice effect". Thus, it is important to develop a reliable method to identify and quantitate the coumarins and furanocoumarins in citrus extracts. For this purpose, we herein describe an ultraperformance liquid chromatography coupled with mass spectrometry (UPLC-MS)-based method. We first developed a rapid UPLC method (20 min) to separate the isomers of each furanocoumarin. A subsequent single ion monitoring MS detection method was performed to distinguish between the molecules, which were possibly coeluting but had different molecular weights. The method was successfully used to separate and quantitate 6 coumarins and 21 furanocoumarins in variable amounts within peel extracts (flavedo and albedo) of 6 varieties of Citrus (sweet orange, lemon, grapefruit, bergamot, pummelo, and clementine). This method combines high selectivity and sensitivity in a rapid analysis and is useful for fingerprinting Citrus species via their coumarin and furanocoumarin contents.

  14. A rapid and sensitive UPLC-MS/MS method for the simultaneous quantification of serum androsterone glucuronide, etiocholanolone glucuronide, and androstan-3α, 17β diol 17-glucuronide in postmenopausal women.

    PubMed

    Ke, Yuyong; Gonthier, Renaud; Isabelle, Maxim; Bertin, Jonathan; Simard, Jean-Nicolas; Dury, Alain Y; Labrie, Fernand

    2015-05-01

    Quantification of steroidal glucuronide conjugates by the indirect methods of immunoassay and GC-MS/MS may underestimate some conjugates since hydrolysis is needed in sample processing. In the present work, a sensitive and rapid liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been developed and validated for the simultaneous direct quantification of androsterone glucuronide, etiocholanolone glucuronide, and androstan-3α, 17β diol 17-glucuronide in postmenopausal women's serum. The quantification limits are 0.1ng/mL for 3α-diol-17G and 4ng/mL for both ADT-G and Etio-G, respectively, with an extraction from 200μL serum while the total run time is less than 6min for all three glucuronides. In this method, solid phase extraction is used for sample preparation. The assay has been validated in compliance with EndoCeutics SOPs and FDA guidelines for bioanalytical method development and validation. The recovery of glucuronides in stripped serum is consistent with that in unstripped serum, where the average difference in stripped and unstripped is less than 10%. A linear regression model fits well the standard curves of all three compounds with R≥0.99 where the weighting factor is 1/X. Interday accuracy and CV for all levels of QCs are within the range of 15% in both stripped and unstripped serum while all calibration curves are within the range of 6% except for LLOQs, which are within the range of 9%. Other parameters have also been assessed such as selectivity, matrix, lipemic and hemolysis effects as well as stabilities in solution and matrix. Incurred sample reanalysis has been performed with a result of over 93% within 20% of the original values. This reliable, sensitive and fast method is ready for large-scale clinical sample assays. PMID:25701608

  15. [Metabolites and metabolic pathways of mesaconitine in rat liver microsomal investigated by using UPLC-MS/MS method in vitro].

    PubMed

    Bi, Yun-Feng; Liu, Shu; Zhang, Rui-Xing; Song, Feng-Rui; Liu, Zhi-Qiang

    2013-12-01

    Mesaconitine was incubated with rat liver microsomes in vitro. The metabolites of mesaconitine in rat liver microsomes were identified by ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method with high resolution power. A typical reaction mixture of 100 mol L-1 Tris-HCI buffer (pH 7.4) containing 0.5 gL-1 microsomal protein and 50 micro molL-1 mesaconitine was prepared. The above reaction mixture was divided into six groups, and the volume of each group was 200 micro L. The incubation mixture was pre-incubated at 37 degrees C for 2 min and the reactions were initiated by adding NADPH generating system. After 90 min incubation at 37 degrees C, 200 micro L of acetonitrile was added to each group to stop the reaction. The metabolites of mesaconitine were investigated by UPLC-MS/MS method. Mesaconitine and 6 metabolites M1-M6 were found in the incubation system. The structures were characterized according to the data from MS/MS spectra and literatures. The metabolic reactions of mesaconitine in rat liver microsomes included the demethylation, deacetylation, dehydrogenation and hydroxylation. The major metabolic pathways of mesaconitine in rat liver microsomes were determined by UPLC-MS/MS on multiple reaction monitoring (MRM) mode combined with specific inhibitors of cytochrome P450 (CYP) isoforms, including alpha-naphthoflavone (CYP1A2), quinine (CYP2D), diethyldithiocarbamate (CYP2E1), ketoconazole (CYP3A) and sulfaphenazole (CYP2C), separately. Mesaconitine was mainly metabolized by CYP3A. CYP2C and CYP2D were also more important CYP isoforms for the metabolism reactions of mesaconitine, but CYP1A2 and CYP2E1 haven't any contribution to MA metabolism in rat liver microsomes. PMID:24689241

  16. Tissue distribution model and pharmacokinetics of nuciferine based on UPLC-MS/MS and BP-ANN.

    PubMed

    Xu, Yanyan; Bao, Shihui; Tian, Weiqiang; Wen, Congcong; Hu, Lufeng; Lin, Chongliang

    2015-01-01

    Nuciferine has shown remarkable biological activities and been considered as a promising drug. In this study, a sensitive and selective ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for determination of nuciferine in tissue and plasma. An electrospray ionization source was applied and operated in positive ion mode; multiple reactions monitoring (MRM) mode was used for quantification using target fragment ions m/z 296.0→265.1 for nuciferine, and m/z 322.0→307.0 for berberrubine internal standard (IS). Based on the UPLC-MS/MS method, the tissue distribution profile of nuciferine in mice and plasma pharmacokinetics in rat were studied. The results showed nuciferine was absorbed through intestinal tract and distributed into tissues rapidly. The bioavailability of nuciferine was identified at 17.9%. It can across through blood brain barrier, the concentrations in liver and kidney are highest, then followed by spleen, lung heart and brain. Nuciferine is eliminated quickly in the tissues and plasma, the t1/2 within 5 hour. The concentrations in these tissues are correlated to each other, and can be predicted by a back-propagation artificial neural network model. PMID:26770351

  17. Tissue distribution model and pharmacokinetics of nuciferine based on UPLC-MS/MS and BP-ANN

    PubMed Central

    Xu, Yanyan; Bao, Shihui; Tian, Weiqiang; Wen, Congcong; Hu, Lufeng; Lin, Chongliang

    2015-01-01

    Nuciferine has shown remarkable biological activities and been considered as a promising drug. In this study, a sensitive and selective ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for determination of nuciferine in tissue and plasma. An electrospray ionization source was applied and operated in positive ion mode; multiple reactions monitoring (MRM) mode was used for quantification using target fragment ions m/z 296.0→265.1 for nuciferine, and m/z 322.0→307.0 for berberrubine internal standard (IS). Based on the UPLC-MS/MS method, the tissue distribution profile of nuciferine in mice and plasma pharmacokinetics in rat were studied. The results showed nuciferine was absorbed through intestinal tract and distributed into tissues rapidly. The bioavailability of nuciferine was identified at 17.9%. It can across through blood brain barrier, the concentrations in liver and kidney are highest, then followed by spleen, lung heart and brain. Nuciferine is eliminated quickly in the tissues and plasma, the t1/2 within 5 hour. The concentrations in these tissues are correlated to each other, and can be predicted by a back-propagation artificial neural network model. PMID:26770351

  18. Pharmacokinetic study of indocyanine Green after intravenous administration by UPLC-MS/MS.

    PubMed

    Chen, Yu; Chen, Dongxin; Hu, Wenhao; Lin, Guanyang; Huang, Shiyong

    2015-01-01

    Indocyanine Green is widely used in medical diagnosis and to evaluate liver function and other regional blood flows in clinical application or animal experiments. In this work, a sensitive and selective ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for determination of Indocyanine Green in rat plasma was developed and validated. After addition of rutin as an internal standard (IS), protein precipitation by acetonitrile-methanol (9:1, v/v) was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH C18 column (2.1 mm × 100 mm, 1.7 μm) with 0.1% formic acid and acetonitrile as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reactions monitoring (MRM) mode was used for quantification using target fragment ions m/z 753.4→330.2 for Indocyanine Green, and m/z 611.1→303.1 for IS. Calibration plots were linear throughout the range 20-5000 ng/mL for Indocyanine Green in rat plasma. Mean recoveries of Indocyanine Green in rat plasma ranged from 79.5% to 85.4%. RSD of intra-day and inter-day precision were both < 12%. The accuracy of the method was between 95.9% and 113.9%. The method was successfully applied to pharmacokinetic study of Indocyanine Green after intravenous administration.

  19. Pharmacokinetic study of indocyanine Green after intravenous administration by UPLC-MS/MS

    PubMed Central

    Chen, Yu; Chen, Dongxin; Hu, Wenhao; Lin, Guanyang; Huang, Shiyong

    2015-01-01

    Indocyanine Green is widely used in medical diagnosis and to evaluate liver function and other regional blood flows in clinical application or animal experiments. In this work, a sensitive and selective ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for determination of Indocyanine Green in rat plasma was developed and validated. After addition of rutin as an internal standard (IS), protein precipitation by acetonitrile-methanol (9:1, v/v) was used to prepare samples. Chromatographic separation was achieved on a UPLC BEH C18 column (2.1 mm × 100 mm, 1.7 μm) with 0.1% formic acid and acetonitrile as the mobile phase with gradient elution. An electrospray ionization source was applied and operated in positive ion mode; multiple reactions monitoring (MRM) mode was used for quantification using target fragment ions m/z 753.4→330.2 for Indocyanine Green, and m/z 611.1→303.1 for IS. Calibration plots were linear throughout the range 20-5000 ng/mL for Indocyanine Green in rat plasma. Mean recoveries of Indocyanine Green in rat plasma ranged from 79.5% to 85.4%. RSD of intra-day and inter-day precision were both < 12%. The accuracy of the method was between 95.9% and 113.9%. The method was successfully applied to pharmacokinetic study of Indocyanine Green after intravenous administration. PMID:26629038

  20. Rapid determination of eight oxoisoaporphine alkaloids in Rhizoma Menispermi by the optimal homogenate extraction followed by UPLC-MS/MS.

    PubMed

    Wei, Jinxia; Jiang, Zhen; Cui, Zhi; Guo, Xingjie

    2015-07-01

    The objective of this study was to develop a rapid and reliable homogenate extraction (HGE) and ultra high-performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method for simultaneous analysis of eight bioactive oxoisoaporphine alkaloids (including two new alkaloids) in Rhizoma Menispermi. HGE was optimized by response surface methodology (RSM) to obtain the maximum extraction efficiency of eight alkaloids. Separation was achieved on a Waters ACQUITY UPLC® BEH C18 column (50 × 2.1 mm(2), 1.7 μm) using gradient elution with a mobile phase consisting of acetonitrile and 0.2% formic acid in water. Quantification was performed with multiple reaction monitoring (MRM) mode using positive ESI as an interface. This is the first report of the simultaneous analysis of eight oxoisoaporphine alkaloids in Rhizoma Menispermi using a UPLC-MS/MS method; this analysis afforded good linearity, precision, and accuracy. Then, the method was successfully applied to determine the alkaloids in Rhizoma Menispermi from different sources.

  1. Ultra-performance liquid chromatography tandem mass-spectrometry (uplc-ms/ms) for the rapid, simultaneous analysis of thiamin, riboflavin, flavin adenine dinucleotide, nicotinamide and pyridoxal in human milk

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A novel, rapid and sensitive Ultra Performance Liquid-Chromatography tandem Mass-Spectrometry (UPLC-MS/MS) method for the simultaneous determination of several B-vitamins in human milk was developed. Resolution by retention time or multiple reaction monitoring (MRM) for thiamin, riboflavin, flavin a...

  2. Determination of anthelmintic drug residues in milk using UPLC-MS/MS with rapid polarity switching

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A new UPLC-MS/MS (ultra-performance liquid chromatography coupled to tandem mass spectrometry) method was developed and validated to detect 38 anthelmintic drug residues, consisting of benzimidazoles, avermectins and flukicides. A modified QuEChERS-type extraction method was developed with an added...

  3. An UPLC-MS/MS method for the analysis of glimepiride and fluoxetine in human plasma.

    PubMed

    Qiu, Xiangjun; Wang, Hong-wei; Yuan, Ye; Wang, Ying-fei; Sun, Ming; Huang, Xue-sun

    2015-02-01

    A sensitive and rapid ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed to determine glimepiride (GPD) and fluoxetine (FLU) in human plasma using diazepam as the internal standard (IS) simultaneously. The presented method used an Acquity UPLC BEH C18 column for chromatographic separation with tandem mass spectrometric detection on a QTrap5500 mass spectrometer operated in positive ESI mode. The mobile phase is a mixture of acetonitrile and 1% formic acid in water with gradient elution at a flow rate of 0.40mL/min. The GPD, FLU and IS were eluted at 1.46, 1.27 and 1.39min, respectively. The MRM transitions of m/z 491.3→126.3 and m/z 310.5→148.1 were used to quantify for GPD and FLU, respectively. The linearity of this method was found to be within the concentration range of 2.5-300ng/mL and 0.1-20ng/mL for GPD and FLU in human plasma, respectively. The intra- and inter-day precision (RSD%) were less than 10.3% and accuracy (RE%) was within ±7.3%. The matrix effect were 95.3-100.7% for GPD and FLU. GPD and FLU were sufficiently stable under all relevant analytical conditions. The method was also successfully applied to the clinical samples after a single oral dose of 2mg GLP and 40mg FLU in patients. PMID:25589252

  4. Simultaneous determination of 30 hormones illegally added to anti-ageing functional foods using UPLC-MS/MS coupled with SPE clean-up.

    PubMed

    He, Xiaoqin; Xi, Cunxian; Tang, Bobin; Wang, Guomin; Chen, Dongdong; Peng, Tao; Mu, Zhaode

    2014-01-01

    A novel analytical method employing solid-phase extraction (SPE) coupled with ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was developed for the simultaneous determination of 30 hormones in anti-ageing functional foods (capsules, powders and tablets). The analytes were extracted with acetic acid-acetonitrile (1-99 v/v), methanol and acetone, respectively. The extract was purified using a combined column, followed by analyte detection with electrospray ionisation in positive- or negative-ion modes. The results indicated that the 30 compounds had good linear correlations in the range of 1-1000 μg kg⁻¹, and the correlation coefficients were above 0.99. The limits of detection (LOD) and limits of quantification (LOQ) were 0.03-2 and 0.1-5 μg kg⁻¹, respectively. The average recovery of 30 compounds at the three spiked levels varied from 74.7% to 124.1%, and the relative standard deviation (RSD) was 2.4-15.0%. This method was applied to the analysis of hormones in 14 real samples of which seven hormones (such as estrone, dienestrol) were detected in four samples, but the remainder of the hormones were not detected. The developed method is sensitive, efficient, reliable and applicable to real samples.

  5. Removal of malathion from aqueous solution using De-Acidite FF-IP resin and determination by UPLC-MS/MS: equilibrium, kinetics and thermodynamics studies.

    PubMed

    Naushad, Mu; Alothman, Z A; Khan, M R

    2013-10-15

    In the present study, De-Acidite FF-IP resin was used to remove a highly toxic and persistent organophosphorus pesticide (malathion) from the aqueous solution. Batch experiments were performed as a function of various experimental parameters such as effect of pH (2-10), contact time (10-120 min), resin dose (0.05-0.5 g), initial malathion concentration (0.5-2.5 µg mL(-1)) and temperature (25-65°C). The concentration of malathion was determined using a sensitive, selective and rapid ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method. The uptake rate of malathion on De-Acidite FF-IP resin was rapid and equilibrium established within 40 min. Kinetics studies showed better applicability for pseudo-second-order model. The equilibrium data was fitted to Langmuir and Freundlich isotherm models and the isotherm constants were calculated for malathion. The values of thermodynamic parameters (ΔG(0), ΔH(0) and ΔS(0)) were computed from the Van't Hoff plot of lnKC vs. 1/T which showed that the adsorption of malathion was feasible, endothermic and spontaneous. The regeneration studies were carried out which demonstrated a decrease in the recovery of malathion from 95% to 68% after five consecutive cycles. Breakthrough and exhaustive capacities of malathion were found to be 1.25 mg g(-1) and 3.5 mg g(-1), respectively.

  6. Development and Validation of a UPLC-MS/MS Method to Monitor Cephapirin Excretion in Dairy Cows following Intramammary Infusion

    PubMed Central

    Ray, Partha; Knowlton, Katharine F.; Shang, Chao; Xia, Kang

    2014-01-01

    Cephapirin, a cephalosporin antibiotic, is used by the majority of dairy farms in the US. Fecal and urinary excretion of cephapirin could introduce this compound into the environment when manure is land applied as fertilizer, and may cause development of bacterial resistance to antibiotics critical for human health. The environmental loading of cephapirin by the livestock industry remains un-assessed, largely due to a lack of appropriate analytical methods. Therefore, this study aimed to develop and validate a cephapirin quantification method to capture the temporal pattern of cephapirin excretion in dairy cows following intramammary infusion. The method includes an extraction with phosphate buffer and methanol, solid-phase extraction (SPE) clean-up, and quantification using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The LOQ values of the developed method were 4.02 µg kg−1 and 0.96 µg L−1 for feces and urine, respectively. This robust method recovered >60% and >80% cephapirin from spiked blank fecal and urine samples, respectively, with acceptable intra- and inter-day variation (<10%). Using this method, we detected trace amounts (µg kg−1) of cephapirin in dairy cow feces, and cephapirin in urine was detected at very high concentrations (133 to 480 µg L−1). Cephapirin was primarily excreted via urine and its urinary excretion was influenced by day (P = 0.03). Peak excretion (2.69 mg) was on day 1 following intramammary infusion and decreased sharply thereafter (0.19, 0.19, 0.08, and 0.17 mg on day 2, 3, 4, and 5, respectively) reflecting a quadratic pattern of excretion (Quadratic: P = 0.03). The described method for quantification of cephapirin in bovine feces and urine is sensitive, accurate, and robust and allowed to monitor the pattern of cephapirin excretion in dairy cows. This data will help develop manure segregation and treatment methods to minimize the risk of antibiotic loading to the environment

  7. Validated UPLC-MS/MS assay for the determination of synthetic phosphodiesterase type-5 inhibitors in postmortem blood samples.

    PubMed

    Proença, Paula; Mustra, Carla; Marcos, Mariana; Franco, João Miguel; Corte-Real, Francisco; Vieira, Duarte Nuno

    2013-08-01

    The use of synthetic phosphodiesterase type 5 (PDE-5) inhibitors for the treatment of erectile dysfunction: sildenafil citrate (Viagra(®)), tadalafil (Cialis(®)) and vardenafil hydrochloride (Levitra(®)) has increased dramatically over the past 2 years. These substances are prescription drugs and must be used under medical supervision. However, they can easily be obtained over the internet from illegal sites, being a potential for a threat to public health. The development of an electrospray ionisation (ESI) ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) procedure for the simultaneous identification and quantification of three PDE5 inhibitors in blood samples was desired. Samples were prepared using Oasis(®) HLB solid-phase cartridges (3 cc, 60 mg) and chromatographic separation was achieved on an Acquity UPLC(®) HSS T3 (100 × 2.1 mm i.d., 1.8 μm particles) column with a gradient mobile phase of 0.1% formic acid and acetonitrile at a 0.5 mL/min flow rate. Quantification was achieved by multiple reaction monitoring (MRM) of two transitions per compound: m/z 475.1 > 58 e m/z 475.1 > 311.1 for sildenafil; m/z 389.9 > 267.9 e m/z 389.9 > 134.8 for tadalafil and m/z 489 > 71.9 e m/z 489 > 150.9 for vardenafil. Zolpidem-d6 (m/z 314.5 > 235.3) was used as the internal standard. Calibration curves were linear over the concentration range of 5-1000 ng/mL, with a coefficient of determination better than 0.997. The lower limits of detection and quantification for these substances were ≤ 3 ng/mL and ≤ 8 ng/mL, respectively. The method showed a satisfactory sensitivity, precision, accuracy, recovery and selectivity. A rapid, selective and sensitive UPLC-MS/MS method using solid-phase extraction was developed for the simultaneous determination and quantification of sildenafil, vardenafil and tadalafil in blood samples. PMID:23910856

  8. Simultaneous determination of four furostanol glycosides in rat plasma by UPLC-MS/MS and its application to PK study after oral administration of Dioscorea nipponica extracts.

    PubMed

    Liao, Min; Dai, Cong; Liu, Mengping; Chen, Jiefeng; Chen, Zuanguang; Xie, Zhiyong; Yao, Meicun

    2016-01-01

    A novel, sensitive and rapid ultra-performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method for simultaneous quantification of four furostanol glycosides in rat plasma was established and validated. Ginsenoside Rb1 was used as an internal standard. Plasma samples were pretreated by liquid-liquid extraction with n-butanol and chromatographed on a C18 column (2.1×50 mm i.d., 2.6 μm) using a gradient elution program consisting of acetonitrile and water (containing 0.03% formic acid and 0.1 mM lithium acetate) at a flow rate of 0.4 mL/min. Lithium adduct ions were employed to enhance the response of the analytes in electrospray positive ionization mode and multiple reaction monitoring transitions were performed for detection. All calibration curves exhibited good linearity (r>0.999) over the range of 10-20,000 ng/mL for protodioscin and 2-4000 ng/mL for protogracillin, pseudoprotodioscin and pseudoprotogracillin. The recoveries of the whole analytes were more than 80.3% and exhibited no severe matrix effect. Meanwhile, the intra- and inter-day precisions were all less than 10.7% and accuracies were within the range of -8.1-12.9%. The four saponins showed rapid excretion and relative high plasma concentrations when the validated method was applied to the PK study of Dioscorea nipponica extracts by intragastric administration at low, medium and high dose to rats. Moreover, the T(1/2) and AUC(0-t) of each compound turned out to behave in a dose-dependent pattern by comparing them at different dose levels.

  9. Pharmacokinetics of Dibutyl Phthalate (DBP) in the Rat Determined by UPLC-MS/MS

    PubMed Central

    Chang, Li-Wen; Hou, Mei-Ling; Tsai, Tung-Hu

    2013-01-01

    Dibutyl phthalate (DBP) is commonly used to increase the flexibility of plastics in industrial products. However, several plasticizers have been illegally used as clouding agents to increase dispersion of aqueous matrix in beverages. This study thus develops a rapid and validated analytical method by ultra-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) for the evaluation of pharmacokinetics of DBP in free moving rats. The UPLC-MS/MS system equipped with positive electrospray ionization (ESI) source in multiple reaction monitoring (MRM) mode was used to monitor m/z 279.25→148.93 transitions for DBP. The limit of quantification for DBP in rat plasma and feces was 0.05 μg/mL and 0.125 μg/g, respectively. The pharmacokinetic results demonstrate that DBP appeared to have a two-compartment model in the rats; the area under concentration versus time (AUC) was 57.8 ± 5.93 min μg/mL and the distribution and elimination half-life (t1/2,α and t1/2,β) were 5.77 ± 1.14 and 217 ± 131 min, respectively, after DBP administration (30 mg/kg, i.v.). About 0.18% of the administered dose was recovered from the feces within 48 h. The pharmacokinetic behavior demonstrated that DBP was quickly degraded within 2 h, suggesting a rapid metabolism low fecal cumulative excretion in the rat. PMID:23344044

  10. Rapid qualitative and quantitative analyses of proanthocyanidin oligomers and polymers by UPLC-MS/MS.

    PubMed

    Engström, Marica T; Pälijärvi, Maija; Fryganas, Christos; Grabber, John H; Mueller-Harvey, Irene; Salminen, Juha-Pekka

    2014-04-16

    This paper presents the development of a rapid method with ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for the qualitative and quantitative analyses of plant proanthocyanidins directly from crude plant extracts. The method utilizes a range of cone voltages to achieve the depolymerization step in the ion source of both smaller oligomers and larger polymers. The formed depolymerization products are further fragmented in the collision cell to enable their selective detection. This UPLC-MS/MS method is able to separately quantitate the terminal and extension units of the most common proanthocyanidin subclasses, that is, procyanidins and prodelphinidins. The resulting data enable (1) quantitation of the total proanthocyanidin content, (2) quantitation of total procyanidins and prodelphinidins including the procyanidin/prodelphinidin ratio, (3) estimation of the mean degree of polymerization for the oligomers and polymers, and (4) estimation of how the different procyanidin and prodelphinidin types are distributed along the chromatographic hump typically produced by large proanthocyanidins. All of this is achieved within the 10 min period of analysis, which makes the presented method a significant addition to the chemistry tools currently available for the qualitative and quantitative analyses of complex proanthocyanidin mixtures from plant extracts.

  11. Simultaneous quantification of vortioxetine, carvedilol and its active metabolite 4-hydroxyphenyl carvedilol in rat plasma by UPLC-MS/MS: Application to their pharmacokinetic interaction study.

    PubMed

    Huang, Yi; Zheng, Shuangli; Pan, Yongyang; Li, Tao; Xu, Zhi-Sheng; Shao, Meng-Meng

    2016-09-01

    To establish a rapid and sensitive ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the determination of vortioxetine, carvedilol and its metabolite 4-hydroxyphenyl carvedilol in rat plasma. The analytes and the internal standard (diazepam) were separated on an Acquity UPLC BEH C18 chromatography column (2.1mm×50mm, 1.7μm) using gradient elution with a mobile phase of acetonitrile and 0.1% formic acid in water at a flow rate of 0.4mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode to monitor the precursor-to-product ion transitions of m/z 299.2→150.1 for vortioxetine, m/z 407.2→100.3 for carvedilol, m/z 423.2→100.1 for 4-hydroxyphenyl carvedilol and m/z 285.2→193.1 for diazepam (IS) using a positive electrospray ionization interface. The method was validated over a concentration range of 0.5-100ng/mL for vortioxetine, 0.5-1000ng/mL for carvedilol and 0.1-50ng/mL for 4-hydroxyphenyl carvedilol. Total time for each chromatograph was 3.0min. The intra- and inter-day precision and accuracy of the quality control samples at low, medium, and high concentration levels exhibited relative standard deviations (RSD)<11.6% and the accuracy values ranged from -12.2% to 11.3%. The analytical method was successfully applied to a pharmacokinetic interaction study of vortioxetine and carvedilol after oral administration vortioxetine and carvedilol in rats. Results suggested that the co-administration of vortioxetine and carvedilol results in a significant drug interaction in rats. PMID:27262994

  12. Simultaneous determination of ledipasvir, sofosbuvir and its metabolite in rat plasma by UPLC-MS/MS and its application to a pharmacokinetic study.

    PubMed

    Pan, Chenwei; Chen, Yongping; Chen, Weilai; Zhou, Guangyao; Jin, Lingxiang; Zheng, Yi; Lin, Wei; Pan, Zhenzhen

    2016-01-01

    In this work, a rapid and sensitive ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the determination of ledipasvir, sofosbuvir and its metabolite GS-331007 in rat plasma was developed. The analytes and the internal standard (diazepam) were separated on an Acquity UPLC BEH C18 chromatography column (2.1mm×50mm, 1.7μm) using gradient elution with a mobile phase of acetonitrile and 0.1% formic acid in water at a flow rate of 0.4mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode to monitor the precursor-to-product ion transitions of m/z 889.8→130.1 for ledipasvir, m/z 530.3→243.1 for sofosbuvir, m/z 261.5→113.1 for GS-331007 and m/z 285.2→193.1 for diazepam (IS) using a positive electrospray ionization interface. The method was validated over a concentration range of 2-500ng/mL for ledipasvir, 10-2000ng/mL for sofosbuvir and 10-2000ng/mL for GS-331007. Total time for each chromatography was 3.0min. The intra- and inter-day precision and accuracy of the quality control samples at low, medium, and high concentration levels exhibited relative standard deviations (RSD)<10.2% and the accuracy values ranged from -9.8% to 11.2%. The method was successfully applied to a pharmacokinetic study of ledipasvir, sofosbuvir and GS-331007 in rats.

  13. Evaluation of a rapid method for the simultaneous quantification of ribavirin, sofosbuvir and its metabolite in rat plasma by UPLC-MS/MS.

    PubMed

    Shi, Xiaojun; Zhu, Dedong; Lou, Jie; Zhu, Bo; Hu, Ai-rong; Gan, Dongmei

    2015-10-01

    A rapid and sensitive ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for the determination of ribavirin, sofosbuvir and its metabolite GS-331007 in rat plasma was established. The analytes and the internal standard (midazolam) were separated on an Acquity UPLC BEH C18 chromatography column (2.1mm×50mm, 1.7μm) using gradient elution with a mobile phase of acetonitrile and 0.1% formic acid in water at a flow rate of 0.4mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM) mode to monitor the precursor-to-product ion transitions of m/z 245.1→113.1 for ribavirin, m/z 530.3→243.1 for sofosbuvir, m/z 261.5→113.1 for GS-331007 and m/z 326.2→291.1 for midazolam (IS) using a positive electrospray ionization interface. The method was validated over a concentration range of 5-1000ng/mL for ribavirin, 10-2000ng/mL for sofosbuvir and 10-2000ng/mL for GS-331007. Total time for each chromatograph was 3.0min. The intra- and inter-day precision and accuracy of the quality control samples at low, medium, and high concentration levels exhibited relative standard deviations (RSD) <10.0% and the accuracy values ranged from -10.6% to 11.6%. The method was successfully applied to a pharmacokinetic study of ribavirin, sofosbuvir and GS-331007 in rats.

  14. Development and validation of an UPLC-MS/MS method for the quantification of ethoxzolamide in plasma and bioequivalent buffers: Applications to absorption, brain distribution, and pharmacokinetic studies

    PubMed Central

    Gao, Song; Zhao, Jing; Yin, Taijun; Ma, Yong; Xu, Beibei; Moore, Anthony N.; Dash, Pramod K.; Hu, Ming

    2015-01-01

    The purpose of this study is to develop and validate an UPLC-MS/MS method to quantify ethoxzolamide in plasma (EZ) and apply the method to absorption, brain distribution, as well as pharmacokinetic studies. A C18 column was used with 0.1% of formic acid in acetonitrile and 0.1% of formic acid in water as the mobile phases to resolve EZ. The mass analysis was performed in a triple quadrupole mass spectrometer using multiple reaction monitoring (MRM) with positive scan mode. The results show that the linear range of EZ is 4.88–10,000.00 nM. The intra-day variance is less than 12.43 % and the accuracy is between 88.88–08.00 %. The inter-day variance is less than 12.87 % and accuracy is between 89.27–115.89 %. Protein precipitation was performed using methanol to extract EZ from plasma and brain tissues. Only 40 µL of plasma is needed for analysis due to the high sensitivity of this method, which could be completed in less than three minutes. This method was used to study the pharmacokinetics of EZ in SD rats, and the transport of EZ in Caco-2 and MDCK-MDR1 overexpressing cell culture models. Our data show that EZ is not a substrate for p-glycoprotein (P-gp) and its entry into the brain may not limited by the blood-brain barrier. PMID:25706567

  15. Simultaneous detection and comparative pharmacokinetics of amoxicillin, clavulanic acid and prednisolone in cows' milk by UPLC-MS/MS.

    PubMed

    Liu, Yuan; Zhu, Kui; Wang, Jianfen; Huang, Xiaoyong; Wang, Guanlin; Li, Congying; Cao, Jie; Ding, Shuangyang

    2016-01-01

    Amoxicillin (AMOX), clavulanic acid (CLAV) and prednisolone (PSL) are widely used in combination for the treatment of mastitis in lactating dairy cows. However, no method has been reported to detect these three chemicals in milk in a single assay. In the present work, a reliable and sensitive UPLC-MS/MS method was developed and validated for simultaneous determination of AMOX, CLAV and PSL in cow's milk. The analytes were determined by a positive and negative ionization electrospray mass spectrometer via multiple reaction monitoring. The linear ranges of AMOX, CLAV and PSL were from 2 to 1000ng/mL, 20-1000ng/mL and 1-1000ng/mL, respectively, with the correlation coefficients greater than 0.999. The limits of quantification (LOQs) were 2ng/mL (AMOX), 20ng/mL (CLAV) and 1ng/mL (PSL). Recoveries of the analytes of interest in milk samples were in the ranges of 84.2-101.4%. The intra-day and inter-day precisions ranged from 1.8% to 11.9%. This method was successfully applied to investigate the pharmacokinetics of AMOX, CLAV and PSL in milk from healthy and mastitic cows. The elimination times of AMOX and PSL in mastitic cows were longer than that in healthy cows, but the elimination times of CLAV did not show significant difference.

  16. Monitoring sea lamprey pheromones and their degradation using rapid stream-side extraction coupled with UPLC-MS/MS

    USGS Publications Warehouse

    Wang, Huiyong; Johnson, Nicholas; Bernardy, Jeffrey; Hubert, Terry; Li, Weiming

    2013-01-01

    Pheromones guide adult sea lamprey (Petromyzon marinus) to suitable spawning streams and mates, and therefore, when quantified, can be used to assess population size and guide management. Here, we present an efficient sample preparation method where 100 mL of river water was spiked with deuterated pheromone as an internal standard and underwent rapid field-based SPE and elution in the field. The combination of field extraction with laboratory UPLC-MS/MS reduced the sample consumption from 1 to 0.1 L, decreased the sample process time from more than 1 h to 10 min, and increased the precision and accuracy. The sensitivity was improved more than one order of magnitude compared with the previous method. The influences of experimental conditions were assessed to optimize the separation and peak shapes. The analytical method has been validated by studies of stability, selectivity, precision, and linearity and by the determination of the limits of detection and quantification. The method was used to quantify pheromone concentration from five streams tributary to Lake Ontario and to estimate that the environmental half-life of 3kPZS is about 26 h.

  17. Development and validation of an UPLC-MS/MS method for the quantification of irinotecan, SN-38 and SN-38 glucuronide in plasma, urine, feces, liver and kidney: Application to a pharmacokinetic study of irinotecan in rats.

    PubMed

    Basu, Sumit; Zeng, Min; Yin, Taijun; Gao, Song; Hu, Ming

    2016-03-15

    The objective of this research is to develop and validate a sensitive and reproducible UPLC-MS/MS method to quantify irinotecan, its active metabolite SN-38 and SN-38 glucuronide (phase II metabolite of SN-38) simultaneously in different bio-matrices (plasma, urine, feces), tissues (liver and kidney) and to use the method to investigate its pharmacokinetic behavior in rats. Irinotecan, SN-38 and SN-38 glucuronide has been resolved and separated by C18 column using acetonitrile and 0.1% formic acid in water used as the mobile phases. Triple quadruple mass spectrometer using multiple reaction monitoring (MRM) with positive scan mode were employed to perform mass analysis. The results showed that the linear response range of irinotecan and SN-38 in plasma, feces, liver and kidney is 4.88-10000 nM, 39-5000 nM, 48.8-6250 nM and 48.8-6250 nM, respectively (R(2)>0.99). In case of SN-38 glucuronide, the standard curves were linear in the concentration range of 6.25-2000 nM, 4.88-1250 nM, 9.8-1250 nM and 9.8-1250 nM in plasma, feces, liver and kidney homogenates, respectively. The lower limit of detection (LLOD) of irinotecan, SN-38 and SN-38 glucuronide was determined to be less than 25 nM in all bio-matrices as well as tissue homogenates. Recoveries of irinotecan, SN-38 and SN-38 glucuronide at three different concentrations (low, medium and high) were not less than 85% at three different concentrations in plasma and feces. The percentage matrix factors in different bio-matrices and tissues were within 20%. The UPLC-MS/MS method was validated with intra-day and inter-day precision of less than 15% in plasma, feces, liver and kidney. Owing to the high sensitivity of this method, only 20 μl of plasma, urine and homogenates of liver, kidney and feces is needed. The validated method has been successfully employed for pharmacokinetic evaluation of irinotecan in male wistar rats to quantify irinotecan, SN-38 and SN-38 glucuronide in plasma, feces, and urine samples. PMID

  18. Free amino acid profiling in the giant puffball mushroom (Calvatia gigantea) using UPLC-MS/MS.

    PubMed

    Kıvrak, İbrahim; Kıvrak, Şeyda; Harmandar, Mansur

    2014-09-01

    Wild edible and medicinal mushroom, Calvatia gigantea, was quantitatively analyzed for the determination of its free amino acids using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The concentrations of total free amino acids, essential and non-essential amino acids were 199.65 mg/100 g, 113.69 mg/100 g, and 85.96 mg/100 g in C. gigantea, respectively. This study showed that C. gigantea, so called a giant puffball mushroom, has free amino acids content. The essential amino acids: tryptophan, isoleucine, valine, phenylalanine, leucine, threonine, lysine, histidine, methionine, and the non-essential amino acids: tyrosine, 4-hyrdroxy proline, arginine, proline, glycine, serine, alanine, glutamine, glutamic acid, aspargine, aspartic acid were detected.

  19. [Characterization and comparison of interferon reference standards using UPLC-MS].

    PubMed

    Tao, Lei; Pei, De-ning; Han, Chun-mei; Chen, Wei; Rao, Chun-ming; Wang, Jun-zhi

    2015-01-01

    The study aims to characterize and compare interferon reference standards from 5 manufacturers. By testing molecular mass and trypsin-digested peptide mass mapping, the amino acid sequence was verified and post-translational modifications such as disulfide bond were identified. Results show that the molecular mass and amino acid sequence were consistent with theory; the disulfide bonds of 4 lots of interferon were Cys1-Cys98/Cys29-Cys138, 1 lot was Cys29-Cys139/Cys86-Cys99; N-terminal "+Met", acetyl N-terminal and Met oxidation were identified in part of the sample. UPLC-MS can be used to characterize and compare interferon reference standards from different manufacturers.

  20. DETERMINATION OF ECOLOGICALLY RELEVANT PHARMACEUTICALS AND THEIR SELECTED METABOLITES IN EFFLUENT AND SURFACE WATER USING UPLC/MS/MS

    EPA Science Inventory

    Objective is to develop analytical methods including SPE and UPLC/MS/MS needed to analyze over 60 human prescription pharamceuticals and metabolites belonging to a multitude of different classes in surface waters and wastewater effluent. The methods will be used in future studies...

  1. Evidence of non-extractable florfenicol residues: development and validation of a confirmatory method for total florfenicol content in kidney by UPLC-MS/MS.

    PubMed

    Faulkner, Dermot; Cantley, Margaret; Walker, Matthew; Crooks, Steven; Kennedy, David; Elliott, Christopher

    2016-06-01

    The parent compound florfenicol (FF) is a broad-spectrum antibacterial compound licensed in the UK for use in cattle, pigs and the aquaculture industry. The analysis of porcine tissues in this study demonstrates that significant amounts of solvent non-extractable FF-related residues are present in incurred tissues (kidney and muscle) from treated animals. The results indicate that methods based on solvent extraction alone may carry a significant risk of reporting false-negative results. The use of a strong acid hydrolysis step prior to solvent extraction of tissue samples is necessary for an accurate estimate of the total tissue FF content. A robust and sensitive method for the determination of total FF residue content in kidney samples by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) has been developed and validated. This method covers the synthetic amphenicol drug FF and its metabolites, measured as the marker residue florfenicol amine (FFA) as per Commission Regulation (EU) No. 37/2010. Non-extractable and intermediate metabolites are converted to the hydrolysis product FFA, and then partitioned into ethyl acetate. Extracts are solvent exchanged prior to a dispersive solid-phase extraction step, then analysed using an alkaline reverse-phase gradient separation by UPLC-MS/MS. The method was validated around the maximum residue levels (MRLs) set out in Regulation (EU) No. 37/2010 for bovine kidney in accordance with Commission Decision No. 2002/657/EC. The following method performance characteristics were assessed during a single laboratory validation study: selectivity, specificity, sensitivity, linearity, matrix effects, accuracy and precision (decision limit (CCα) and detection capability (CCβ) were determined). PMID:27053017

  2. Seasonal and Species Variation of the Hepatotoxin Indospicine in Australian Indigofera Legumes As Measured by UPLC-MS/MS.

    PubMed

    Tan, Eddie T T; Materne, Christopher M; Silcock, Richard G; D'Arcy, Bruce R; Al Jassim, Rafat; Fletcher, Mary T

    2016-08-31

    Livestock industries have maintained a keen interest in pasture legumes because of the high protein content and nutritive value. Leguminous Indigofera plant species have been considered as having high feeding values to be utilized as pasture, but the occurrence of the toxic constituent indospicine in some species has restricted this utility. Indospicine has caused both primary and secondary hepatotoxicosis and also reproductive losses, but has only previously been determined in a small number of Indigofera species. This paper validates a high-throughput ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to determine the indospicine content of various Indigofera species found in Australian pasture. Twelve species of Indigofera together with Indigastrum parviflorum plants were collected and analyzed. Of the 84 samples analyzed, *I. spicata (the asterisk indicates a naturalized species) contained the highest indospicine level (1003 ± 328 mg/kg DM, n = 4) followed by I. linnaei (755 ± 490 mg/kg DM, n = 51). Indospicine was not detected in 9 of the remaining 11 species and at only low levels (<10 mg/kg DM) in 2 of 8 I. colutea specimens and in 1 of 5 I. linifolia specimens. Indospicine concentrations were below quantitation levels for other Indigofera spp. (I. adesmiifolia, I. georgei, I. hirsuta, I. leucotricha, *I. oblongifolia, I. australis, and I. trita) and Indigastrum parviflorum. One of the more significant findings to emerge from this study is that the indospicine content of I. linnaei is highly variable (from 159 to 2128 mg/kg DM, n = 51) and differs across both regions and seasons. Its first regrowth after spring rain has a higher (p < 0.01) indospicine content than growth following more substantial summer rain. The species collected include the predominant Indigofera in Australia pasture, and of these, only *I. spicata and I. linnaei contain high enough levels of indospicine to pose a potential toxic threat to grazing

  3. A method of analysis for T-2 toxin and neosolaniol by UPLC-MS/MS in apple fruit inoculated with Trichothecium roseum.

    PubMed

    Tang, Yamei; Xue, Huali; Bi, Yang; Li, Yongcai; Wang, Yi; Zhao, Ying; Shen, Keping

    2015-01-01

    Trichothecenes are one of the most important groups of mycotoxins produced by Trichothecium roseum, which causes core rot of apple. A reliable and sensitive method was developed and successfully applied for the rapid detection of trichothecenes including T-2 toxin and neosolaniol in harvested apple using UPLC-MS/MS. After the extraction of the two mycotoxins from the apple matrix with methanol/water (80/20, v/v), the concentrated extracts were cleaned-up by PriboFast M270 columns and then analysed by UPLC-MS/MS. T-2 toxin and neosolaniol were effectively separated as unique peaks. The validity of this method was established by its linearity (R(2) ≥ 0.9995), precision (relative standard deviation ≤ 3.6%), accuracy, selectivity, limit of detection of 2-5 μg kg(-1), limit of quantification of 5-10 μg kg(-1) and average recovery of 73-96%. Levels of T-2 toxin were found in the range 7.1-128.4 µg kg(-1) in the core rot lesion of three cultivars apple (cvs. Red Delicious, Fuji and Ralls). T-2 was detected not only in the lesion, but also in the tissue without any disease symptoms. However, neosolaniol was only detected in the lesion on 'Red Delicious' apples. In addition, the concentration of T-2 toxin in the susceptible cultivar (cv. Fuji) was significantly higher than that in the resistant one (cv. Ralls). This method proved to be suitable at detecting T-2 and neosolaniol simultaneously in apples infected with T. roseum.

  4. Photodegradation assessment of ciprofloxacin, moxifloxacin, norfloxacin and ofloxacin in the presence of excipients from tablets by UPLC-MS/MS and DSC

    PubMed Central

    2013-01-01

    Background Ciprofloxacin (CIP), moxifloxacin (MOX), norfloxacin (NOR) and ofloxacin (OFL), are the antibacterial synthetic drugs, belonging to the fluoroquinolones group. Fluoroquinolones are compounds susceptible to photodegradation process, which may lead to reduction of their antibacterial activity and to induce phototoxicity as a side effect. This paper describes a simple, sensitive UPLC-MS/MS method for the determination of CIP, MOX, NOR and OFL in the presence of photodegradation products. Results Chromatographic separations were carried out using the Acquity UPLC BEH C18 column; (2.1 × 100 mm, 1.7 μm particle size). The column was maintained at 40°C, and the following gradient was used: 0 min, 95% of eluent A and 5% of eluent B; 10 min, 0% of eluent A and 100% of eluent B, at a flow rate of 0.3 mL min-1. Eluent A: 0.1% (v/v) formic acid in water; eluent B: 0.1% (v/v) formic acid in acetonitrile. The method was validated and all the validation parameters were in the ranges acceptable by the guidelines for analytical method validation. The photodegradation of examined fluoroquinolones in solid phase in the presence of excipients followed kinetic of the first order reaction and depended upon the type of analyzed drugs and coexisting substances. Photodegradation process of analyzed drugs was confirmed by differential scanning calorimetry. In addition, the identification of degradation products was carried out by mass spectrometry. Conclusion The developed UPLC-MS/MS method enables the determination of CIP, MOX, NOR and OFL in the presence of photodegradation products and identification of photodegradation products. PMID:23899303

  5. Identification of a ligand for tumor necrosis factor receptor from Chinese herbs by combination of surface plasmon resonance biosensor and UPLC-MS.

    PubMed

    Cao, Yan; Li, Ying-Hua; Lv, Di-Ya; Chen, Xiao-Fei; Chen, Lang-Dong; Zhu, Zhen-Yu; Chai, Yi-Feng; Zhang, Jun-Ping

    2016-07-01

    Identification of bioactive compounds directly from complex herbal extracts is a key issue in the study of Chinese herbs. The present study describes the establishment and application of a sensitive, efficient, and convenient method based on surface plasmon resonance (SPR) biosensors for screening active ingredients targeting tumor necrosis factor receptor type 1 (TNF-R1) from Chinese herbs. Concentration-adjusted herbal extracts were subjected to SPR binding assay, and a remarkable response signal was observed in Rheum officinale extract. Then, the TNF-R1-bound ingredients were recovered, enriched, and analyzed by UPLC-QTOF/MS. As a result, physcion-8-O-β-D-monoglucoside (PMG) was identified as a bioactive compound, and the affinity constant of PMG to TNF-R1 was determined by SPR affinity analysis (K D  = 376 nM). Pharmacological assays revealed that PMG inhibited TNF-α-induced cytotoxicity and apoptosis in L929 cells via TNF-R1. Although PMG was a trace component in the chemical constituents of the R. officinale extract, it had considerable anti-inflammatory activities. It was found for the first time that PMG was a ligand for TNF receptor from herbal medicines. The proposed SPR-based screening method may prove to be an effective solution to analyzing bioactive components of Chinese herbs and other complex drug systems. Graphical abstract Scheme of the method based on SPR biosensor for screening and recovering active ingredients from complex herbal extracts and UPLC-MS for identifying them. Scheme of the method based on SPR biosensor for screening and recovering active ingredients from complex herbal extracts and UPLC-MS for identifying them.

  6. Simultaneous determination of loganin, morroniside, catalpol and acteoside in normal and chronic kidney disease rat plasma by UPLC-MS for investigating the pharmacokinetics of Rehmannia glutinosa and Cornus officinalis Sieb drug pair extract.

    PubMed

    Zhao, Min; Tao, Jinhua; Qian, Dawei; Liu, Pei; Shang, Er-xin; Jiang, Shu; Guo, Jianming; Su, Shu-lan; Duan, Jin-ao; Du, Leyue

    2016-01-15

    A sensitive and rapid method for determination of loganin, morroniside, catalpol and acteoside in rat plasma after oral administration of Rehmannia glutinosa Libosch and Cornus officinalis Sieb drug pair based on ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS). Chromatographic separation was achieved using an Acquity UPLC BEH C18 column (100mm×2.1mm, 1.7μm) at a flow rate of 0.4mL/min, using gradient mode containing 0.1% formic acid in water and acetonitrile were used as the mobile phase A and B. Loganin, morroniside, catalpol, acteoside and the internal standard (chloramphenicol) were detected by selected reaction monitoring in the negative ion mode with the mass transition of m/z 451.0→179.0 (morroniside), m/z 435.0→227.0 (loganin), m/z 407.1→199.1 (catalpol), m/z 623.2→161.0 (acteoside) and m/z 320.8→151.9 (chloramphenicol), respectively. All calibration curves showed good linearity (r>0.991). The precision was evaluated by intra-day and inter-day assays and the RSD% were all within 9.58%. The recovery ranged from 67.62 to 80.14%. The method was successfully applied to pharmacokinetic study of the analytes in normal and doxorubicin-induced chronic kidney disease rat plasma.

  7. Synthesis of Isotopically Labeled (13)C3-Simazine and Development of a Simultaneous UPLC-MS/MS Method for the Analysis of Simazine in Soil.

    PubMed

    Song, Yan; Guo, Yangzhen; Zhang, Xia; Yang, Yue; Chen, Shuo; She, Gaimei; She, Dongmei

    2016-01-14

    The isotope dilution mass spectrometry (IDMS) is a highly efficient method for tackling the ion suppression in complex matrix by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), but a lack of commercial internal standards is a limiting factor for these analyses. Herein, an economical and efficient strategy for the synthesis of (13)C3-simazine via a three-step procedure was developed. The isotope-labeled internal standard was used for determination of simazine residue in soil samples. The quantitation method has a limit of detection of 0.015 μg/kg and quantitation of 0.08 μg/kg. The inter-day and intra-day precision of the method were below 4.6%. Recovery values were ranged between 92.9% and 99.2%. All the samples obtained from six provinces in China contained from 1 to 62 μg/kg of simazine.

  8. Simultaneous determination of mequindox, quinocetone, and their major metabolites in chicken and pork by UPLC-MS/MS.

    PubMed

    Li, Yanshen; Liu, Kaili; Beier, Ross C; Cao, Xingyuan; Shen, Jianzhong; Zhang, Suxia

    2014-10-01

    This report presents a UPLC-MS/MS method for determination of mequindox (MEQ), quinocetone (QCT) and their 11 metabolites in chicken and pork samples. Following extraction process with acetonitrile-ethyl acetate, acidulation, and re-extraction with ethyl acetate in turn, target analytes were further purified using C18 solid phase extraction (SPE) cartridges for UPLC-MS/MS analysis. Validation was processed with mean recoveries from 69.1% to 113.3% with intra-day relative standard deviation (RSD) <14.7%, inter-day RSD <19.2%, and limit of detection between 0.05 and 1.0 μg/kg for each analytes. The verified method was successfully applied to the quantitative determination of commercial samples. This developed procedure will help to control food animal products with MEQ and QCT residues, and facilitate further pharmacokinetic and residue studies of similar quinoxaline-1,4-dioxide veterinary drugs. PMID:24799224

  9. Identification and quantitation of new glutamic acid derivatives in soy sauce by UPLC/MS/MS.

    PubMed

    Frerot, Eric; Chen, Ting

    2013-10-01

    Glutamic acid is an abundant amino acid that lends a characteristic umami taste to foods. In fermented foods, glutamic acid can be found as a free amino acid formed by proteolysis or as a non-proteolytic derivative formed by microorganisms. The aim of the present study was to identify different structures of glutamic acid derivatives in a typical fermented protein-based food product, soy sauce. An acidic fraction was prepared with anion-exchange solid-phase extraction (SPE) and analyzed by UPLC/MS/MS and UPLC/TOF-MS. α-Glutamyl, γ-glutamyl, and pyroglutamyl dipeptides, as well as lactoyl amino acids, were identified in the acidic fraction of soy sauce. They were chemically synthesized for confirmation of their occurrence and quantified in the selected reaction monitoring (SRM) mode. Pyroglutamyl dipeptides accounted for 770 mg/kg of soy sauce, followed by lactoyl amino acids (135 mg/kg) and γ-glutamyl dipeptides (70 mg/kg). In addition, N-succinoylglutamic acid was identified for the first time in food as a minor compound in soy sauce (5 mg/kg).

  10. Determination of Glucocorticoids in UPLC-MS in Environmental Samples from an Occupational Setting

    PubMed Central

    Oddone, Enrico; Negri, Sara; Bellinzona, Massimo; Martino, Silvia; Di Tuccio, Marcello; Grignani, Elena; Cottica, Danilo; Imbriani, Marcello

    2015-01-01

    Occupational exposures to glucocorticoids are still a neglected issue in some work environments, including pharmaceutical plants. We developed an analytical method to quantify simultaneously 21 glucocorticoids using UPLC coupled with mass spectrometry to provide a basis to carry out environmental monitoring. Samples were taken from air, hand-washing tests, pad-tests and wipe-tests. This paper reports the contents of the analytical methodology, along with the results of this extensive environmental and personal monitoring of glucocorticoids. The method in UPLC-MS turned out to be suitable and effective for the aim of the study. Wipe-test and pad-test desorption was carried out using 50 mL syringes, a simple technique that saves time without adversely affecting analyte recovery. Results showed a widespread environmental pollution due to glucocorticoids. This is of particular concern. Evaluation of the dose absorbed by each worker and identification of a biomarker for occupational exposure will contribute to assessment and prevention of occupational exposure. PMID:25821468

  11. Large Scale Non-targeted Metabolomic Profiling of Serum by Ultra Performance Liquid Chromatography-Mass Spectrometry (UPLC-MS)

    PubMed Central

    Broeckling, Corey D.; Heuberger, Adam L.; Prenni, Jessica E.

    2013-01-01

    Non-targeted metabolite profiling by ultra performance liquid chromatography coupled with mass spectrometry (UPLC-MS) is a powerful technique to investigate metabolism. The approach offers an unbiased and in-depth analysis that can enable the development of diagnostic tests, novel therapies, and further our understanding of disease processes. The inherent chemical diversity of the metabolome creates significant analytical challenges and there is no single experimental approach that can detect all metabolites. Additionally, the biological variation in individual metabolism and the dependence of metabolism on environmental factors necessitates large sample numbers to achieve the appropriate statistical power required for meaningful biological interpretation. To address these challenges, this tutorial outlines an analytical workflow for large scale non-targeted metabolite profiling of serum by UPLC-MS. The procedure includes guidelines for sample organization and preparation, data acquisition, quality control, and metabolite identification and will enable reliable acquisition of data for large experiments and provide a starting point for laboratories new to non-targeted metabolite profiling by UPLC-MS. PMID:23524330

  12. Metabonomics evaluation of urine from rats given acute and chronic doses of acetaminophen using NMR and UPLC/MS.

    PubMed

    Sun, Jinchun; Schnackenberg, Laura K; Holland, Ricky D; Schmitt, Thomas C; Cantor, Glenn H; Dragan, Yvonne P; Beger, Richard D

    2008-08-15

    Urinary metabolic perturbations associated with acute and chronic acetaminophen-induced hepatotoxicity were investigated using nuclear magnetic resonance (NMR) spectroscopy and ultra performance liquid chromatography/mass spectrometry (UPLC/MS) metabonomics approaches to determine biomarkers of hepatotoxicity. Acute and chronic doses of acetaminophen (APAP) were administered to male Sprague-Dawley rats. NMR and UPLC/MS were able to detect both drug metabolites and endogenous metabolites simultaneously. The principal component analysis (PCA) of NMR or UPLC/MS spectra showed that metabolic changes observed in both acute and chronic dosing of acetaminophen were similar. Histopathology and clinical chemistry studies were performed and correlated well with the PCA analysis and magnitude of metabolite changes. Depletion of antioxidants (e.g. ferulic acid), trigonelline, S-adenosyl-L-methionine, and energy-related metabolites indicated that oxidative stress was caused by acute and chronic acetaminophen administration. Similar patterns of metabolic changes in response to acute or chronic dosing suggest similar detoxification and recovery mechanisms following APAP administration.

  13. Simultaneous Analysis of Cannabinoid and Synthetic Cannabinoids in Dietary Supplements Using UPLC with UV and UPLC-MS-MS.

    PubMed

    Heo, Seok; Yoo, Geum Joo; Choi, Ji Yeon; Park, Hyoung Joon; Do, Jung-Ah; Cho, Sooyeul; Baek, Sun Young; Park, Sung-Kwan

    2016-06-01

    The primary purpose of this study was to develop and validate a method based on UPLC with UV and UPLC-MS-MS for the simultaneous analysis of different cannabinoids and synthetic cannabinoids in food as well as in herbal and dietary supplements. The limits of detection and quantitation of the method ranged from 0.1 to 0.3 and 0.3 to 0.9 μg/mL by UPLC with UV, respectively. The coefficient of determination was >0.999; the intra- and interday precision of the method were 0.1-3.7 and 0.9-4.1%, respectively. The intra- and interday accuracy were 94.8-103.1 and 98.3-100.9%, respectively. The mean recoveries of nine cannabinoids obtained from tablet samples ranged from 81.1 to 105.4%. The mean extraction recoveries of nine target cannabinoids obtained from various types of samples (tablets, capsules, powders, liquids, cookies and candies) ranged from 82.26 to 112.40%. The relative standard deviation (RSD) of the stability of the prepared sample solutions was <1.80%. Identification and quantification of the nine cannabinoids were accomplished by ion spray UPLC-MS-MS using multiple reaction monitoring. The UPLC-MS-MS method was validated for linearity (R(2) > 0.99); the precision was 0.1-4.0% (intraday) and 0.1-2.8% (interday), and the accuracy was 98.0-103.5% (intraday) and 97.1-103.2% (interday). The mean extraction recoveries of six types of samples were 82.2-114.5% and the RSD of stability was <6.54%, complying with the established international guidelines. The results indicated that the method can be used for rapid and accurate screening of cannabinoids present in food.

  14. Simultaneous Analysis of Cannabinoid and Synthetic Cannabinoids in Dietary Supplements Using UPLC with UV and UPLC-MS-MS.

    PubMed

    Heo, Seok; Yoo, Geum Joo; Choi, Ji Yeon; Park, Hyoung Joon; Do, Jung-Ah; Cho, Sooyeul; Baek, Sun Young; Park, Sung-Kwan

    2016-06-01

    The primary purpose of this study was to develop and validate a method based on UPLC with UV and UPLC-MS-MS for the simultaneous analysis of different cannabinoids and synthetic cannabinoids in food as well as in herbal and dietary supplements. The limits of detection and quantitation of the method ranged from 0.1 to 0.3 and 0.3 to 0.9 μg/mL by UPLC with UV, respectively. The coefficient of determination was >0.999; the intra- and interday precision of the method were 0.1-3.7 and 0.9-4.1%, respectively. The intra- and interday accuracy were 94.8-103.1 and 98.3-100.9%, respectively. The mean recoveries of nine cannabinoids obtained from tablet samples ranged from 81.1 to 105.4%. The mean extraction recoveries of nine target cannabinoids obtained from various types of samples (tablets, capsules, powders, liquids, cookies and candies) ranged from 82.26 to 112.40%. The relative standard deviation (RSD) of the stability of the prepared sample solutions was <1.80%. Identification and quantification of the nine cannabinoids were accomplished by ion spray UPLC-MS-MS using multiple reaction monitoring. The UPLC-MS-MS method was validated for linearity (R(2) > 0.99); the precision was 0.1-4.0% (intraday) and 0.1-2.8% (interday), and the accuracy was 98.0-103.5% (intraday) and 97.1-103.2% (interday). The mean extraction recoveries of six types of samples were 82.2-114.5% and the RSD of stability was <6.54%, complying with the established international guidelines. The results indicated that the method can be used for rapid and accurate screening of cannabinoids present in food. PMID:27185817

  15. Quantitative evaluation of berberine subcellular distribution and cellular accumulation in non-small cell lung cancer cells by UPLC-MS/MS.

    PubMed

    Yuan, Zhong-Wen; Leung, Elaine Lai-Han; Fan, Xing-Xing; Zhou, Hua; Ma, Wen-Zhe; Liu, Liang; Xie, Ying

    2015-11-01

    Berberine, an isoquinoline alkaloid, has been demonstrated to be a safe anti-cancer agent with multiple effects on mitochondria. Intracellular concentration and distribution around the targeting sites are determinants of efficacy, but subcellular distribution of berberine has not been fully elucidated yet, which relies on the sensitive and robustness assay. In this study, a sensitive and robust UPLC-MS/MS method has been developed and validated with optimized extraction solvents and detection conditions. Key factors such as the purity and integrity of isolated organelle fractions, and the effects of isolation procedures on the subcellular concentration of berberine were systemically evaluated. With the developed assay, we found that the intracellular accumulations of berberine in two gefitinib resistant NSCLC cell lines H1650 and H1975 were 2-3 folds higher than that of normal epithelial cells BEAS-2B. Moreover, significantly different subcellular distribution profiles in NSCLC cancer cells from that of BEAS-2B cells with a striking increase in content in most organelles may contribute to its selective cytotoxicity to cancer cells. Furthermore, a predominant accumulation of berberine was observed for the first time in microsomal fraction for all three cell lines. Therefore, this method could be used for quantitative evaluation of subcellular distribution and cellular accumulation of berberine and for further evaluation of the concentration-effects relationship.

  16. A reversed-phase capillary ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) method for comprehensive top-down/bottom-up lipid profiling

    PubMed Central

    Gao, Xiaoli; Zhang, Qibin; Meng, Da; Issac, Giorgis; Zhao, Rui; Fillmore, Thomas L.; Chu, Rosey K.; Zhou, Jianying; Tang, Keqi; Hu, Zeping; Moore, Ronald J.; Smith, Richard D.; Katze, Michael G.; Metz, Thomas O.

    2012-01-01

    Lipidomics is a critical part of metabolomics and aims to study all the lipids within a living system. We present here the development and evaluation of a sensitive capillary UPLC-MS method for comprehensive top-down/bottom-up lipid profiling. Three different stationary phases were evaluated in terms of peak capacity, linearity, reproducibility, and limit of quantification (LOQ) using a mixture of lipid standards representative of the lipidome. The relative standard deviations of the retention times and peak abundances of the lipid standards were 0.29% and 7.7%, respectively, when using the optimized method. The linearity was acceptable at >0.99 over 3 orders of magnitude, and the LOQs were sub-fmol. To demonstrate the performance of the method in the analysis of complex samples, we analyzed lipids extracted from a human cell line, rat plasma, and a model human skin tissue, identifying 446, 444, and 370 unique lipids, respectively. Overall, the method provided either higher coverage of the lipidome, greater measurement sensitivity, or both, when compared to other approaches of global, untargeted lipid profiling based on chromatography coupled with MS. PMID:22354571

  17. Determination of a novel anticancer c-Met inhibitor LS-177 in rat plasma and tissues with a validated UPLC-MS/MS method: application to pharmacokinetics and tissue distribution study.

    PubMed

    Ju, Ping; Liu, Zhenzhen; Jiang, Yu; Zhao, Simin; Zhang, Lunhui; Zhang, Yuanyuan; Gu, Liqiang; Tang, Xing; Bi, Kaishun; Chen, Xiaohui

    2015-07-01

    LS-177 is a novel small-molecule kinase inhibitor employed to interrupt the c-Met signaling pathway. A rapid and sensitive ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for determination of LS-177 in rat plasma and tissues. The biosamples were extracted by liquid-liquid extraction with methyl tert-butyl ether and separated on a C18 column (50 × 4.6 mm, 2.6 µm) using a gradient elution mobile phase consisting of acetonitrile-0.1% formic acid water. Under the optimal conditions, the selectivity of the method was satisfactory with no endogenous interference. The intraday and interday precisions (relative standard deviation) were <10.5% and the accuracy (relative error) was from -12.5 to 12.5% at all quality control levels. Excellent recovery and negligible matrix effects were observed. Stability studies showed that LS-177 was stable during the preparation and analytical processes. The UPLC-MS/MS method was successfully applied to pharmacokinetic and tissue distribution studies. The results indicated that there was no significant drug accumulation after multiple-dose oral administration of LS-177. The tissue distribution study exhibited significant higher uptakes of LS-177 in stomach, intestine, lung and liver among all of the tissues. The results in pharmacokinetics and tissue distribution may provide a meaningful basis for clinical application.

  18. Determination of Asymmetric and Symmetric Dimethylarginine in Serum from Patients with Chronic Kidney Disease: UPLC-MS/MS versus ELISA

    PubMed Central

    Boelaert, Jente; Schepers, Eva; Glorieux, Griet; Eloot, Sunny; Vanholder, Raymond; Lynen, Frédéric

    2016-01-01

    Asymmetric dimethylarginine (ADMA), an endogenous inhibitor of nitric oxide (NO) synthesis, and its structural isomer symmetric dimethylarginine (SDMA) are uremic toxins accumulating in chronic kidney disease (CKD) patients. The objective of this study was to develop and validate a robust UPLC-MS/MS method for the simultaneous determination of ADMA and SDMA in human serum. Chromatographic separation after butyl ester derivatization was achieved on an Acquity UPLC BEH C18 column, followed by tandem mass spectrometric detection. After validation, the applicability of the method was evaluated by the analysis of serum samples from 10 healthy controls and 77 CKD patients on hemodialysis (CKD5HD). Both ADMA (0.84 ± 0.19 µM vs. 0.52 ± 0.07 µM) and SDMA concentrations (2.06 ± 0.82 µM vs. 0.59 ± 0.13 µM) were significantly (p < 0.001) elevated in CKD5HD patients compared to healthy controls. In general, low degrees of protein binding were found for both ADMA and SDMA. In addition, an established commercially available ELISA kit was utilized on the same samples (n = 87) to compare values obtained both with ELISA and UPLC-MS/MS. Regression analysis between these two methods was significant (p < 0.0001) but moderate for both ADMA (R = 0.78) and SDMA (R = 0.72). PMID:27187471

  19. Optimization and evaluation of metabolite extraction protocols for untargeted metabolic profiling of liver samples by UPLC-MS.

    PubMed

    Masson, Perrine; Alves, Alexessander Couto; Ebbels, Timothy M D; Nicholson, Jeremy K; Want, Elizabeth J

    2010-09-15

    A series of six protocols were evaluated for UPLC-MS based untargeted metabolic profiling of liver extracts in terms of reproducibility and number of metabolite features obtained. These protocols, designed to extract both polar and nonpolar metabolites, were based on (i) a two stage extraction approach or (ii) a simultaneous extraction in a biphasic mixture, employing different volumes and combinations of extraction and resuspension solvents. A multivariate statistical strategy was developed to allow comparison of the multidimensional variation between the methods. The optimal protocol for profiling both polar and nonpolar metabolites was found to be an aqueous extraction with methanol/water followed by an organic extraction with dichloromethane/methanol, with resuspension of the dried extracts in methanol/water before UPLC-MS analysis. This protocol resulted in a median CV of feature intensities among experimental replicates of <20% for aqueous extracts and <30% for organic extracts. These data demonstrate the robustness of the proposed protocol for extracting metabolites from liver samples and make it well suited for untargeted liver profiling in studies exploring xenobiotic hepatotoxicity and clinical investigations of liver disease. The generic nature of this protocol facilitates its application to other tissues, for example, brain or lung, enhancing its utility in clinical and toxicological studies. PMID:20715759

  20. [UPLC-MS/MS determination of content of three iridoids of xingnaojing oral preparation in rat brains and study on their brain pharmacokinetics].

    PubMed

    Xu, Pan; Du, Shou-Ying; Lu, Yang; Bai, Jie; Liu, Hui-Min; Du, Qiu; Chen, Zhen-Zhen; Wang, Zhen

    2014-06-01

    To establish a UPLC-MS/MS method for the simultaneous determination of geniposide, genipin 1-O-beta-D-gentiobioside and geniposidic acid in rat brains and study the brain pharmacokinetics of the three iridoid glycosides in stroke rat after the oral administration of Xingnaojing. In this experiment, brain samples were precipitated with protein for twice. Acquity BEH C18 column was adopted, with acetonitrile-0.1% formic acid-water as the mobile phase for gradient elution. ESI source was adopted for mass spectra; multiple reaction monitoring (MRM) was conducted to detect negative ions. The time for sample analysis was 3.5 min. the results showed good linear relations among the three iridoid glycosides, with the extraction recovery between 99.6% and 114.3%, good intra- and inter-day precisions and accuracies and stability in line with the requirements. The t1/2 and MRT in the three components were similar in brains of stroke rats. Geniposide and genipin 1-O-beta-D-gentiobioside showed double peaks; where as geniposidic acid showed a single peak. In conclusion, the method is so specific, sensitive, accurate and reliable that it can be used to study the brain pharmacokinetics of Xingnaojing oral preparation.

  1. Differentiating organically and conventionally grown oregano using ultraperformance liquid chromatography mass spectrometry (UPLC-MS), headspace gas chromatography with flame ionization detection (headspace-GC-FID), and flow injection mass spectrum (FIMS) fingerprints combined with multivariate data analysis.

    PubMed

    Gao, Boyan; Qin, Fang; Ding, Tingting; Chen, Yineng; Lu, Weiying; Yu, Liangli Lucy

    2014-08-13

    Ultraperformance liquid chromatography mass spectrometry (UPLC-MS), flow injection mass spectrometry (FIMS), and headspace gas chromatography (headspace-GC) combined with multivariate data analysis techniques were examined and compared in differentiating organically grown oregano from that grown conventionally. It is the first time that headspace-GC fingerprinting technology is reported in differentiating organically and conventionally grown spice samples. The results also indicated that UPLC-MS, FIMS, and headspace-GC-FID fingerprints with OPLS-DA were able to effectively distinguish oreganos under different growing conditions, whereas with PCA, only FIMS fingerprint could differentiate the organically and conventionally grown oregano samples. UPLC fingerprinting provided detailed information about the chemical composition of oregano with a longer analysis time, whereas FIMS finished a sample analysis within 1 min. On the other hand, headspace GC-FID fingerprinting required no sample pretreatment, suggesting its potential as a high-throughput method in distinguishing organically and conventionally grown oregano samples. In addition, chemical components in oregano were identified by their molecular weight using QTOF-MS and headspace-GC-MS.

  2. Analysis of the Enantioselective Effects of PCB95 in Zebrafish (Danio rerio) Embryos through Targeted Metabolomics by UPLC-MS/MS

    PubMed Central

    Xu, Nana; Mu, Pengqian; Yin, Zhiqiang; Jia, Qi; Yang, Shuming; Qian, Yongzhong; Qiu, Jing

    2016-01-01

    As persistent organic pollutants, polychlorinated biphenyls (PCBs) accumulate in the bodies of animals and humans, resulting in toxic effects on the reproductive, immune, nervous, and endocrine systems. The biological and toxicological characteristics of enantiomers of chiral PCBs may differ, but these enantioselective effects of PCBs have not been fully characterized. In this study, we performed metabolomics analysis, using ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) to investigate the enantioselective toxic effects of PCB95 in zebrafish (Danio rerio) embryos after exposure to three dose levels of 0.1, 1, and 10 μg/L for 72 h. Multivariate analysis directly reflected the metabolic perturbations caused by PCB95. The effects of (-)-PCB95 and (+)-PCB95 were more prominent than those of the racemate in zebrafish embryos. A total of 26 endogenous metabolites were selected as potential marker metabolites with variable importance at projection values larger than 1 and significant differences (p<0.05). These metabolites included amino acids, organic acids, nucleosides, betaine, and choline. The changes in these biomarkers were dependent on the enantiomer-specific structures of PCB95. Fifteen metabolic pathways were significantly affected, and several nervous and immune system-related metabolites were significantly validated after exposure. These metabolic changes indicated that the toxic effects of PCB95 may be associated with the interaction of PCB95 with the nervous and immune systems, thus resulting in disruption of energy metabolism and liver function. PMID:27500732

  3. Analysis of the Enantioselective Effects of PCB95 in Zebrafish (Danio rerio) Embryos through Targeted Metabolomics by UPLC-MS/MS.

    PubMed

    Xu, Nana; Mu, Pengqian; Yin, Zhiqiang; Jia, Qi; Yang, Shuming; Qian, Yongzhong; Qiu, Jing

    2016-01-01

    As persistent organic pollutants, polychlorinated biphenyls (PCBs) accumulate in the bodies of animals and humans, resulting in toxic effects on the reproductive, immune, nervous, and endocrine systems. The biological and toxicological characteristics of enantiomers of chiral PCBs may differ, but these enantioselective effects of PCBs have not been fully characterized. In this study, we performed metabolomics analysis, using ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) to investigate the enantioselective toxic effects of PCB95 in zebrafish (Danio rerio) embryos after exposure to three dose levels of 0.1, 1, and 10 μg/L for 72 h. Multivariate analysis directly reflected the metabolic perturbations caused by PCB95. The effects of (-)-PCB95 and (+)-PCB95 were more prominent than those of the racemate in zebrafish embryos. A total of 26 endogenous metabolites were selected as potential marker metabolites with variable importance at projection values larger than 1 and significant differences (p<0.05). These metabolites included amino acids, organic acids, nucleosides, betaine, and choline. The changes in these biomarkers were dependent on the enantiomer-specific structures of PCB95. Fifteen metabolic pathways were significantly affected, and several nervous and immune system-related metabolites were significantly validated after exposure. These metabolic changes indicated that the toxic effects of PCB95 may be associated with the interaction of PCB95 with the nervous and immune systems, thus resulting in disruption of energy metabolism and liver function. PMID:27500732

  4. Quantitative Determination of Levonorgestrel in Fish Plasma using UPLC-MS/MS

    EPA Science Inventory

    In this study, a sensitive high-performance liquid chromatography electrospray tandem mass spectrometric method was developed for the determination of levonorgestrel in fish plasma using levonorgestrel-d6 as an internal standard (IS). In the laboratory, the fish cunner, (Tautogol...

  5. Development of a Rapid Microbore Metabolic Profiling Ultraperformance Liquid Chromatography-Mass Spectrometry Approach for High-Throughput Phenotyping Studies.

    PubMed

    Gray, Nicola; Adesina-Georgiadis, Kyrillos; Chekmeneva, Elena; Plumb, Robert S; Wilson, Ian D; Nicholson, Jeremy K

    2016-06-01

    A rapid gradient microbore ultraperformance liquid chromatography-mass spectrometry (UPLC-MS) method has been developed to provide a high-throughput analytical platform for the metabolic phenotyping of urine from large sample cohorts. The rapid microbore metabolic profiling (RAMMP) approach was based on scaling a conventional reversed-phase UPLC-MS method for urinary profiling from 2.1 mm × 100 mm columns to 1 mm × 50 mm columns, increasing the linear velocity of the solvent, and decreasing the gradient time to provide an analysis time of 2.5 min/sample. Comparison showed that conventional UPLC-MS and rapid gradient approaches provided peak capacities of 150 and 50, respectively, with the conventional method detecting approximately 19 000 features compared to the ∼6 000 found using the rapid gradient method. Similar levels of repeatability were seen for both methods. Despite the reduced peak capacity and the reduction in ions detected, the RAMMP method was able to achieve similar levels of group discrimination as conventional UPLC-MS when applied to rat urine samples obtained from investigative studies on the effects of acute 2-bromophenol and chronic acetaminophen administration. When compared to a direct infusion MS method of similar analysis time the RAMMP method provided superior selectivity. The RAMMP approach provides a robust and sensitive method that is well suited to high-throughput metabonomic analysis of complex mixtures such as urine combined with a 5-fold reduction in analysis time compared with the conventional UPLC-MS method. PMID:27116471

  6. Simultaneous determination of nintedanib and its metabolite BIBF 1202 in different tissues of mice by UPLC-MS/MS and its application in drug tissue distribution study.

    PubMed

    Xu, Xiao-wei; Su, Xin-juan; Zhang, Yu-niao; Zheng, Xiao-kang; Lv, Peng-fei; Hu, Jie

    2015-10-01

    A sensitive and rapid ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed to simultaneous determine nintedanib and BIBF 1202 in mice plasma and tissue using carbamazepine as the internal standard (IS). Sample preparation was accomplished through a protein precipitation procedure with acetonitrile. The analyte and IS were separated on an Acquity UPLC BEH C18 column (2.1mm×50mm, 1.7μm) with the mobile phase of acetonitrile and 0.1% formic acid in water with gradient elution at a flow rate of 0.40mL/min. The detection was performed on a triple quadrupole tandem mass spectrometer equipped with electrospray ionization (ESI) by multiple reactions monitoring (MRM) of the transitions at m/z 540.3→113.1 for nintedanib, m/z 526.3→113.1 for BIBF 1202 and m/z 237.1→194.1 for IS, respectively. The linearity of this method was found to be within the concentration range of 1-1000ng/mL with a lower limit of quantification of 1.0ng/mL for each drug. Only 3.0min was needed for an analytical run. The inter-day and intra-day precision and accuracy of quality control (QC) samples, evaluated both in plasma and tissue homogenates, were all within 15%. The method was successfully applied to the pharmacokinetic and tissue distribution study of nintedanib and BIBF 1202 in mice after oral administration of nintedanib.

  7. Rapid and simple UPLC-MS/MS method for precise phytochelatin quantification in alga extracts.

    PubMed

    Bräutigam, Anja; Wesenberg, Dirk; Preud'homme, Hugues; Schaumlöffel, Dirk

    2010-09-01

    Quantitative phytochelatin (PC) analysis is, due to oxidation sensitivity of the PCs, matrix effects, and time consuming sample preparation, still a challenging analytical task. In this study, a rapid, simple, and sensitive method for precise determination of native PCs in crude extracts of the green alga Chlamydomonas reinhardtii was developed. Algae were exposed 48 h to 70 μM Cd. Coupling of ultra performance liquid chromatography and electrospray ionization tandem mass spectrometry with multi-reaction mode transitions for detection permitted the required short-time, high-resolution separation and detection specificity. Thus, under optimized chromatographic conditions, 10 thiol peptides were baseline-separated within 7 min. Relative detection limits in the nanomolar range in microliter sample volumes were achieved (corresponding to absolute detection limits at femtomole level). Next to glutathione (GSH), the most abundant cadmium-induced PCs in C. reinhardtii, namely CysGSH, PC(2), PC(3), CysPC(2), and CysPC(3), were quantified with high reproducibility at concentrations between 15 and 198 nmol g(-1) fresh weight. The biological variation of PC synthesis of nine independently grown alga cultures was determined to be on average 13.7%. PMID:20632163

  8. Determination of total folates in infant formula and adult nutritionals by trienzyme extraction and UPLC-MS/MS Quantitation: First Action 2011.06.

    PubMed

    Szpylka, John; DeVries, Jon; Cheney, Andrea; House, Steve

    2012-01-01

    The method for "Determination of Total Folates in Infant Formula and Adult Nutritionals by Trienzyme Extraction and UPLC-MS/MS Quantitation" was submitted to the Folate Working Group for consideration for adoption as Official First Action by AOAC INTERNATIONAL. This method uses ultra performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) to determine the total folates in infant formulas and adult nutritionals after trienzyme digestion. Deconjugation of the various folate polyglutamates to folate monoglutamates is achieved by using rat plasma conjugase after the sample digestion with protease and a-amylase during the trienzyme digestion process. This method shows linearity of folate concentrations in the range of 10-19 100 microg/100 g. Extension of the range to cover folate concentrations of 5-2 000 000 microg/100 g can be achieved with appropriate adjustment of the sample weight and SPE cleanup loading volume. The recoveries ranged from 94.10 to 101.34%.

  9. Comparison of sample preparation methods, validation of an UPLC-MS/MS procedure for the quantification of tetrodotoxin present in marine gastropods and analysis of pufferfish.

    PubMed

    Nzoughet, Judith Kouassi; Campbell, Katrina; Barnes, Paul; Cooper, Kevin M; Chevallier, Olivier P; Elliott, Christopher T

    2013-02-15

    Tetrodotoxin (TTX) is one of the most potent marine neurotoxins reported. The global distribution of this toxin is spreading with the European Atlantic coastline now being affected. Climate change and increasing pollution have been suggested as underlying causes for this. In the present study, two different sample preparation techniques were used to extract TTX from Trumpet shells and pufferfish samples. Both extraction procedures (accelerated solvent extraction (ASE) and a simple solvent extraction) were shown to provide good recoveries (80-92%). A UPLC-MS/MS method was developed for the analysis of TTX and validated following the guidelines contained in the Commission Decision 2002/657/EC for chemical contaminant analysis. The performance of this procedure was demonstrated to be fit for purpose. This study is the first report on the use of ASE as a mean for TTX extraction, the use of UPLC-MS/MS for TTX analysis, and the validation of this method for TTX in gastropods.

  10. Simultaneous quantification of picfeltarraenins IA and IB in rat plasma by UPLC-MS/MS: Application to a pharmacokinetic study.

    PubMed

    He, Xin; Zhang, Yingjie; Gao, Hang; Li, Keyan; Zhang, Yazhuo; Sun, Limin; Tao, Guizhou

    2016-02-20

    A simple and rapid quantitative UPLC-MS/MS method for simultaneous determination of picfeltarraenins IA and IB in rat plasma was developed and validated in accordance with the US FDA Bioanalytical Guidance (2001). Analytes were extracted from rat plasma by using methanol and separated on Agilent ZORBAX SB-C18 (50mm×2.1mm, 1.8μm) column by using a mobile phase composed of methanol and water (70:30, v/v). Eluents were monitored by ESI tandem mass spectrometry detection with SRM mode using ion transitions m/z 785.4→639.5, m/z 815.5→669.5, and m/z 763.5→455.3 for picfeltarraenin IA, picfeltarraenin IB, and internal standard, respectively. The method was validated over the linear range of 11.5-1150ng/mL and 13.0-1300ng/mL. The developed analytical method was applied to support a pharmacokinetic study on simultaneous estimation of picfeltarraenins IA and IB in rats.

  11. Development of an UPLC-MS/MS method for the determination of antibiotic ertapenem on dried blood spots.

    PubMed

    la Marca, Giancarlo; Giocaliere, Elisa; Villanelli, Fabio; Malvagia, Sabrina; Funghini, Silvia; Ombrone, Daniela; Filippi, Luca; De Gaudio, Marina; De Martino, Maurizio; Galli, Luisa

    2012-03-01

    Ertapenem (Invanz) is a newly developed carbapenem β-lactam antimicrobial agent. The drug usage in pediatric age needs an accurate drug monitoring for effective patient management. The aim of this study was to evaluate the use of dried blood spot (DBS) specimens to measure ertapenem concentration during treatment. The analysis was performed by UPLC-MS/MS operating in multiple reaction monitoring (MRM) mode. The calibration curve in matrix was linear in the concentration range of 0.5-100 mg/L with correlation coefficient value higher than 0.997. Performance parameters of this method like lower limit of detection (LLOD, 0.2 mg/L), lower limit of quantification (LLOQ, 0.5 mg/L), matrix effect (20%), intra- and inter-day imprecision (CV within than 15%) and accuracy (between 94 and 155%) of drug concentrations have been evaluated. The drug stability at different temperatures was tested for one month, to evaluate the risks of sample delivery at different climatic conditions. The reported method allows now ertapenem analysis and offers many advantages for patients including the possibility of collecting samples at home. This new assay is both precise and accurate and is especially suitable for therapeutic drug monitoring and pharmacokinetic studies in neonates in whom obtaining larger blood samples is not convenient or possible.

  12. Validation of JWH-018 and its metabolites in blood and urine by UPLC-MS/MS: Monitoring in forensic cases.

    PubMed

    Erol Öztürk, Yeter; Yeter, Oya; Alpertunga, Buket

    2015-03-01

    The herbal products referred to as 'Spice' have been used as 'legal alternatives' to cannabis worldwide since 2004. The first synthetic cannabinoid JWH-018 was detected in 'Spice' products in 2008, and has been banned by many legal authorities since the beginning of 2009. In order to prove use of JWH cannabinoids (JWHs), specific and robust methods were needed. We have developed a specific and reliable method for the detection and quantification of JWH-018, JWH-018 N-pentanoic acid, and JWH-018 N-(5-hydroxypentyl) in blood and urine using solid-phase extraction followed by UPLC-MS/MS analysis. The method has been validated in terms of linearity (0.1-50ng/mL), selectivity, intra-assay and inter-assay accuracy and precision (CV<15%), recovery (85-98%), limits of detection (LOD) (0.08-0.14ng/mL), and quantification (LOQ) (0.10-0.21ng/mL). Matrix effects, stability, and process efficiency were also assessed. The method has been applied to 868 authentic samples received by the Department of Chemistry (Istanbul) in the Council of Forensic Medicine of the Ministry of Justice.

  13. Determination of ω-6 and ω-3 PUFA metabolites in human urine samples using UPLC/MS/MS.

    PubMed

    Sasaki, Ai; Fukuda, Hayato; Shiida, Narumi; Tanaka, Nobuaki; Furugen, Ayako; Ogura, Jiro; Shuto, Satoshi; Mano, Nariyasu; Yamaguchi, Hiroaki

    2015-02-01

    The ω-6 and ω-3 polyunsaturated fatty acids (PUFAs) such as arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are the precursors of various bioactive lipid mediators including prostaglandins, thromboxanes, leukotrienes, hydroxyeicosatetraenoic acid, isoprostanes, lipoxins, and resolvins (Rvs). These lipid mediators play important roles in various physiological and pathological processes. The quantitative determination of PUFA metabolites seems necessary for disease research and for developing biomarkers. However, there is a paucity of analytical methods for the quantification of ω-6 and ω-3 PUFA metabolites—the specialized pro-resolving mediators (SPMs) present in the human urine. We developed a method for the quantification of ω-6 and ω-3 PUFA metabolites present in human urine using ultra-performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS). The developed method shows good linearity, with a correlation coefficient >0.99 for all of the analytes. The validation results indicate that our method is adequately reliable, accurate, and precise. The method was successfully used to examine urine samples obtained from 43 healthy volunteers. We could identify 20 PUFA metabolites, and this is the first report of the quantitative determination of RvD1, 17(R)-RvD1, 11-dehydro thromboxane B3, RvE2, and 5(S)-HETE in human urine. The urinary 8-iso PGF(2α) and PGE2 levels were significantly higher in the men smokers than in the men nonsmokers (p < 0.05). In this study, we developed an accurate, precise, and novel analytical method for estimating the ω-6 and ω-3 PUFA metabolites, and this is the first report that the SPMs derived from EPA and DHA are present in human urine.

  14. Simultaneous Determination of Bosentan, Glimepiride, HYBOS and M1 in Rat Plasma by UPLC-MS-MS and its Application to Pharmacokinetic Study.

    PubMed

    Chen, Mengchun; Song, Wenjie; Wang, Shuanghu; Chen, Qiulei; Pan, Peipei; Xu, Tao; Hu, Guoxin; Zheng, Zhiqiang

    2016-08-01

    A rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method for the simultaneous determination of bosentan (BOS), glimepiride (GLP), hydroxyl bosentan (HYBOS) and hydroxyl glimepiride (M1) in rat plasma using one-step protein precipitation was developed and validated. After addition of ambrisentan as an internal standard (IS), protein precipitation by acetonitrile was used in sample preparation. Chromatographic separation was achieved on a Waters ACQUITY UPLC BEH C18 column (2.1 mm × 100 mm, 1.7 μm particle size, Waters Corp., Milford, MA, USA) and inline 0.2 μm stainless steel frit filter (Waters Corp.) with acetonitrile-0.1% formic acid as the mobile phase at a flow rate of 0.4 mL/min with gradient elution. The column temperature was maintained at 40°C. Only 4 min was needed for an analytical run. The retention times were ∼3.29 min for BOS, 3.56 min for GLP, 1.42 min for HYBOS, 1.53 min for M1 and 3.22 min for IS. Electrospray ionization source was employed and operated in positive-ion mode; multiple reaction monitoring mode was applied to target fragment ions m/z 552 → 202, m/z 568 → 202, m/z 491 → 352, m/z 507 → 352 and m/z 379 → 347 for BOS, HYBOS, GLP, M1 and IS, respectively. The assay was validated over concentration ranges of 25-5,000 ng/mL (r(2) = 0.9984) for BOS, 1-200 ng/mL (r(2) = 0.9999) for GLP, 0.5-100 ng/mL (r(2) = 0.9999) for HYBOS and 0.1-20 ng/mL (r(2) = 0.9984) for M1. Intra- and interday precision values for replicate quality control samples were within 14.2% for all analytes during the assay validation. Mean quality control accuracy values were within -3.3 to 14.4% of nominal values for all analytes. The mean recoveries of BOS, GLP, HYBOS, M1 and ambrisentan from the plasma exceeded 90.4%. The analytes were stable in rat plasma for at least 2 h at room temperature, 30 days at -40°C and following at least three freeze-thaw cycles (-40°C to room temperature). This method was

  15. UPLC-MS/MS detection of disaccharides derived from glycosaminoglycans as biomarkers of mucopolysaccharidoses.

    PubMed

    Auray-Blais, Christiane; Lavoie, Pamela; Tomatsu, Shunji; Valayannopoulos, Vassili; Mitchell, John J; Raiman, Julian; Beaudoin, Maxime; Maranda, Bruno; Clarke, Joe T R

    2016-09-14

    Mucopolysaccharidoses (MPSs) are a group of disorders resulting from primary defects in lysosomal enzymes involved in the degradation of glycosaminoglycans (GAGs). Depending on the specific enzyme defect, the catabolism of one or more GAGs is blocked leading to accumulation in tissues and biological fluids. GAG measurements are important for high-risk screening, diagnosis, monitoring treatment efficacy, and patient follow up. The dimethylmethylene blue (DMB) spectrophotometric method commonly used in most biochemical genetics laboratories relies on a non-specific total GAG analysis which has led to false positive results, and even false negative results (mainly for MPS III and IV patients). The main objective of our project was to devise and validate a reliable tandem mass spectrometry multiplex analysis for the urine quantitation of four GAGs (dermatan sulfate (DS), heparan sulfate (HS), keratan sulfate (KS), and chondroitin sulfate (CS)) for an eventual technological transfer to the clinic. The developed methodology is rapid (7 min) and our results showed good intraday and interday precision (RSDs ≤ 8.7%) and accuracy (Biases range: -12.0%-18.4%). Linearity was good (r(2) > 0.995) for DS, HS, CS, and KS calibration curves. In comparison with the DMB spectrophotometric method, this multiplex tandem mass spectrometry method allows GAG fractionation, thus a differentiation of MPS types, except for MPS I and II which are characterized by the same GAG profile. The devised method is a useful and reliable tool for diagnosis of MPS patients, as well as their monitoring and follow up, as shown by longitudinal studies. PMID:27566349

  16. Quantitation of the Oral Anticoagulants Dabigatran, Rivaroxaban, Apixaban, and Warfarin in Plasma Using Ultra-Performance Liquid Chromatography with Tandem Mass Spectrometry (UPLC-MS/MS).

    PubMed

    Noguez, Jaime H; Ritchie, James C

    2016-01-01

    This chapter describes a method to measure the oral anticoagulants dabigatran, rivaroxaban, apixaban, and warfarin in plasma samples using ultra-performance liquid chromatography combined with tandem mass spectrometry (UPLC-MS/MS). The instrument is operated in multiple reaction monitoring (MRM) mode with an electrospray ionization (ESI) source in positive ionization mode. Samples are extracted with a 90:10 methanol/0.1 N hydrochloric acid solution containing stable isotope-labeled internal standards for each analyte. After centrifugation the supernatant is transferred to a mass spectrometry vial, injected onto the UPLC-ESI-MS/MS, and quantified using an eight-point calibration curve.

  17. Screening of lignan patterns in Schisandra species using ultrasonic assisted temperature switch ionic liquid microextraction followed by UPLC-MS/MS analysis.

    PubMed

    Dong, Wei; Yu, Shuijing; Deng, Yangwu; Pan, Tao

    2016-01-01

    The ultrasonic assisted temperature-switch ionic liquid microextraction (UATS-ILME) has been successfully applied in extracting of seven lignans from Schisandra. 1-Butyl-3-methylimidazolium tetrafluoroborate ([C4MIM][BF4]) aqueous solution was selected for extracting the target analytes in raw material at 80°C. The lignans were deposited into a single drop by in situ forming 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM][PF6]) by cooling down to 0°C and centrifuging for 10min. The extracts were analyzed by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) in a robust multiple-reaction monitoring (MRM) mode in five minutes. Meanwhile, the proposed method was validated and successfully applied to the determination of seven lignans in twelve Schisandra species. The results indicated that UATS-ILME combined with UPLC-MS/MS is a powerful and practical tool, which has great potential for comprehensive quality control of herbal medicines. PMID:26625336

  18. Validation of a confirmatory method of salbutamol in sheep hair by UPLC-MS/MS and its application to pharmacokinetic study.

    PubMed

    Decheng, Suo; Wei, Zhang; Yu, Zhang; Genlong, Zhao; Ruigou, Wang; PeiLong, Wang; Xiaoou, Su

    2015-10-10

    A new method for determining salbutamol in hair of sheep by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was established. Samples were extracted with 0.1M of HCl solution. The mixture was heated to 60 °C in a water bath and kept at this temperature for 4h. The extracts were purified through SPE method and then dried with nitrogen. Residues were redissolved in mobile phase. The target compound was determined by UPLC-MS/MS with BEH-C18 column. The usefulness and feasibility of different treatment procedures of hair containing salbutamol were evaluated. The range of linearity was 1-100 ng/g. The LOD was 0.3 ng/g, and the LOQ was 1 ng/g. Recoveries were 89-106%, and coefficients of variation were 3.2-13.9%. Pharmacokinetics of salbutamol was studied in healthy sheep after oral administration of 150 μg/kg body weight salbutamol for 21 consecutive days. Salbutamol residues in hair were still detected after 21 days of administration. PMID:25988297

  19. Validation of a confirmatory method of salbutamol in sheep hair by UPLC-MS/MS and its application to pharmacokinetic study.

    PubMed

    Decheng, Suo; Wei, Zhang; Yu, Zhang; Genlong, Zhao; Ruigou, Wang; PeiLong, Wang; Xiaoou, Su

    2015-10-10

    A new method for determining salbutamol in hair of sheep by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was established. Samples were extracted with 0.1M of HCl solution. The mixture was heated to 60 °C in a water bath and kept at this temperature for 4h. The extracts were purified through SPE method and then dried with nitrogen. Residues were redissolved in mobile phase. The target compound was determined by UPLC-MS/MS with BEH-C18 column. The usefulness and feasibility of different treatment procedures of hair containing salbutamol were evaluated. The range of linearity was 1-100 ng/g. The LOD was 0.3 ng/g, and the LOQ was 1 ng/g. Recoveries were 89-106%, and coefficients of variation were 3.2-13.9%. Pharmacokinetics of salbutamol was studied in healthy sheep after oral administration of 150 μg/kg body weight salbutamol for 21 consecutive days. Salbutamol residues in hair were still detected after 21 days of administration.

  20. Pharmacokinetic properties of isorhamnetin, kaempferol and quercetin after oral gavage of total flavones of Hippophae rhamnoides L. in rats using a UPLC-MS method.

    PubMed

    Li, Guowen; Zeng, Xiaoli; Xie, Yan; Cai, Zhenzhen; Moore, Jeffrey C; Yuan, Xiurong; Cheng, Zhihong; Ji, Guang

    2012-01-01

    An ultra performance liquid chromatography-mass spectrometric (UPLC-MS) method was developed to investigate the pharmacokinetic properties of isorhamnetin, kaempferol and quercetin from a total flavone extract of Hippophae rhamnoides L. (TFH) after single dose oral administration. Rat plasma samples were pretreated using liquid-liquid extraction, and chromatographic separation was performed on a C(18) column using a linear gradient of methanol and formic acid (0.1%). The pharmacokinetic parameters of isorhamnetin, kaempferol and quercetin from TFH in rats were quantitatively determined by UPLC with photodiode array detection (PDA). The qualitative detection of the three flavones was accomplished by selected ion monitoring in negative ion mode ESI-MS. Results of the pharmacokinetic study indicate that the three flavones in TFH were absorbed by passive diffusion in rats, and no "double-peak" phenomenon was observed in C-t curves of the three flavones from TFH except for quercetin. Results of this study indicate that the pharmacokinetic behaviors of isorhamnetin, kaempferol and quercetin when administered together in a complex herbal extract might be different than the individual behaviors of the same compounds administered in their pure forms. Results of this study also demonstrate that UPLC-MS is a rapid and practical method to determine the pharmacokinetic parameters of flavones present in an herbal extract. PMID:22056665

  1. Screening of lignan patterns in Schisandra species using ultrasonic assisted temperature switch ionic liquid microextraction followed by UPLC-MS/MS analysis.

    PubMed

    Dong, Wei; Yu, Shuijing; Deng, Yangwu; Pan, Tao

    2016-01-01

    The ultrasonic assisted temperature-switch ionic liquid microextraction (UATS-ILME) has been successfully applied in extracting of seven lignans from Schisandra. 1-Butyl-3-methylimidazolium tetrafluoroborate ([C4MIM][BF4]) aqueous solution was selected for extracting the target analytes in raw material at 80°C. The lignans were deposited into a single drop by in situ forming 1-butyl-3-methylimidazolium hexafluorophosphate ([C4MIM][PF6]) by cooling down to 0°C and centrifuging for 10min. The extracts were analyzed by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) in a robust multiple-reaction monitoring (MRM) mode in five minutes. Meanwhile, the proposed method was validated and successfully applied to the determination of seven lignans in twelve Schisandra species. The results indicated that UATS-ILME combined with UPLC-MS/MS is a powerful and practical tool, which has great potential for comprehensive quality control of herbal medicines.

  2. Quantitative Assessment of the Influence of Rhizoma Zingiberis on the Level of Aconitine in Rat Gut Sacs and Qualitative Analysis of the Major Influencing Components of Rhizoma Zingiberis on Aconitine Using UPLC/MS

    PubMed Central

    Xin, Yang; Liu, Shuying

    2015-01-01

    This study attempted to clarify the material basis for the detoxification of Rhizoma Zingiberis (RZ) on aconitine, an analgesic drug, by quantitatively assessing the influence of RZ on the in vitro intestinal concentration of aconitine using an everted gut sac model and by qualitatively identifying the components in the RZ extract. To quantify aconitine in rat everted gut sacs, both an accurate processing method and a sensitive detection method were required. We developed a three-step sample processing method to protect the components from decomposition and applied ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC/TQMS) to quantify aconitine, glucose and digoxin. In addition, ultra-performance liquid chromatography coupled with linear ion trap mass spectrometry (UPLC/ITMS) was applied to detect the potential antidotal components in the RZ extract. Finally, the RZ extract reduced the level of aconitine in everted gut sacs, and eleven gingerols were successfully identified, which could be considered potential antidotal components for aconitine. This study demonstrated the application of two UPLC/MS methods for analyzing the material basis for the reciprocity between Chinese medicine components in everted gut sacs. PMID:25978042

  3. Simultaneous determination of paeoniflorin, albiflorin, ferulic acid, tetrahydropalmatine, protopine, typhaneoside, senkyunolide I in Beagle dogs plasma by UPLC-MS/MS and its application to a pharmacokinetic study after Oral Administration of Shaofu Zhuyu Decoction.

    PubMed

    Huang, Xiaochen; Su, Shulan; Cui, Wenxia; Liu, Pei; Duan, Jin-ao; Guo, Jianming; Li, Zhenhao; Shang, Erxin; Qian, Dawei; Huang, Zhijun

    2014-07-01

    In this present study, a sensitive and rapid UPLC-MS/MS method was developed for simultaneous quantification of paeoniflorin, albiflorin, ferulic acid, tetrahydropalmatine, protopine, typhaneoside and senkyunolide I in Beagle dog plasma after oral administration of the Shao-Fu-Zhu-Yu Decoction. Chloramphenicol and clarithromycin were used as internal standards. Plasma samples were processed by protein precipitation with methanol. The separation was performed on an Acquity BEH C18 column (100mm×2.1mm, 1.7μm) at a flow-rate of 0.4mL/min, using 0.1% formic acid-acetonitrile as mobile phase. Method validation was performed as per Food and Drug Administration guidelines and the results met the acceptance criteria. After validation, this method was successfully applied to a pharmacokinetic study. The results showed that the apparent plasma clearance of paeoniflorin, albiflorin, typhaneoside and senkyunolide I were significantly higher than others. Double peak was observed in plasma concentration curves of tetrahydropalmatine, the ferulic acid had a good absorption in Beagle dog plasma, and senkyunolide I was detected in plasma from the first blood sampling time (15min) and rapidly reached Tmax. The compound of typhaneoside has a low bioavailability according to the results. PMID:24907546

  4. A UPLC-MS/MS method for simultaneous determination of danshensu, protocatechuic aldehyde, rosmarinic acid, and ligustrazine in rat plasma, and its application to pharmacokinetic studies of Shenxiong glucose injection in rats.

    PubMed

    Zheng, Lin; Gong, Zipeng; Lu, Yuan; Xie, Yumin; Huang, Yong; Liu, Yue; Lan, Yanyu; Wang, Aimin; Wang, Yonglin

    2015-08-01

    A rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the simultaneous determination of the four major active ingredients, danshensu, protocatechuic aldehyde, rosmarinic acid, and ligustrazine, in the traditional Chinese medicine Shenxiong glucose injection in rat plasma. Acidified and alkalized plasma samples were extracted using ethyl acetate, and separated on a Waters C18 column (2.1mm×50mm, 1.7μm) by using a gradient mobile phase system of acetonitrile-water containing 0.1% formic acid and luteoloside as an internal standard. Electrospray ionization in the positive-ion mode and multiple reaction monitoring were used to identify and quantitate the active components. All calibration curves showed good linearity (r>0.994) over the concentration range, with a lower limit of quantification (LLOQ) between 0.02 and 0.21μg/mL. The precision of the in vivo study was evaluated by intra- and inter-day assays, and the percentage of relative standard deviation was within 15%. Moreover, satisfactory extraction efficiency was obtained (between 83.94 and 117.81%) by liquid-liquid extraction. The validated method was successfully applied in a pharmacokinetic study in rats after intravenous administration of Shenxiong glucose injection. The results showed that the four bioactive ingredients in Shenxiong glucose injection have linear pharmacokinetic properties in rats after intravenous injection within the administered dose range and partially different ones compared to single ingredient.

  5. UPLC-MS/MS determination of ephedrine, methylephedrine, amygdalin and glycyrrhizic acid in Beagle plasma and its application to a pharmacokinetic study after oral administration of Ma Huang Tang.

    PubMed

    Yan, Tianhua; Fu, Qiang; Wang, Jing; Ma, Shiping

    2015-02-01

    An ultra performance liquid chromatography-mass spectrometric (UPLC-MS) method was developed to investigate the pharmacokinetic properties of ephedrine, methylephedrine, amygdalin, and glycyrrhizic acid after oral gavage of Ma Huang Tang (MHT) in Beagles. Beagle plasma samples were pretreated using liquid-liquid extraction, and chromatographic separation was performed on a C18 column using a linear gradient of water-formic acid mixture (0.1%). The pharmacokinetic parameters of ephedrine, methylephedrine, amygdalin, and glycyrrhizic acid from MHT in Beagles were quantitatively determined by UPLC with tandem mass detector. The qualitative detection of the four compounds was accomplished by selected ion monitoring in negative/positive ion modes electrospray ionization-mass spectrometry (ESI-MS). Detection was based on multiple reaction monitoring with the precursor-to-product ion transitions m/z 166.096-116.983 (ephedrine), m/z 179.034-146.087 (methylephedrine), m/z 456.351-323.074 (amygdalin), and m/z 821.606-351.062 (glycyrrhizic acid). The selectivity, sensitivity, linearity, accuracy, precision, extraction recovery, ion suppression, and stability were within the acceptable ranges. The method described was successfully applied to reveal the pharmacokinetic properties of ephedrine, methylephedrine, amygdalin, and glycyrrhizic acid after oral gavage of MHT in Beagles.

  6. QuEChERS-based purification method coupled to ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to determine six quaternary ammonium compounds (QACs) in dairy products.

    PubMed

    Xian, Yanping; Dong, Hao; Wu, Yuluan; Guo, Xindong; Hou, Xiangchang; Wang, Bin

    2016-12-01

    QuEChERS-based purification coupled with UPLC-MS/MS method, was developed for six quaternary ammonium compounds (QACs) determination in dairy products. Powder samples were firstly dispersed by water. Protein in liquid milk was precipitated and sample solution was extracted by acetonitrile. QuEChERS-based purification was used to purify the solution. QACs were finally separated by HILIC column and detected in MRM mode of MS/MS under ESI(+). The stable isotope benzyl-2,3,4,5,6-d5-dimethyltetradecylammonium bromide (C14-BAC-d5) was used as an internal standard. This method was validated in terms of linearity, sensitivity, precision, accuracy. Linear relations were favorable for QACs over the selected concentration ranges of 0.2-50μg/L, with correlation coefficients greater than 0.999. The limits of detection (LODs) were in the range of 0.4-14.5μg/kg. Recoveries were between 91.2% and 115% with RSDs of 2.8-7.5% for intra-day precision and 3.7-6.7% for inter-day precision. This validated method was successfully applied to determine the QACs concentrations in dairy products. PMID:27374511

  7. Quantitative Assessment of the Influence of Rhizoma Zingiberis on the Level of Aconitine in Rat Gut Sacs and Qualitative Analysis of the Major Influencing Components of Rhizoma Zingiberis on Aconitine Using UPLC/MS.

    PubMed

    Xin, Yang; Liu, Shuying

    2015-01-01

    This study attempted to clarify the material basis for the detoxification of Rhizoma Zingiberis (RZ) on aconitine, an analgesic drug, by quantitatively assessing the influence of RZ on the in vitro intestinal concentration of aconitine using an everted gut sac model and by qualitatively identifying the components in the RZ extract. To quantify aconitine in rat everted gut sacs, both an accurate processing method and a sensitive detection method were required. We developed a three-step sample processing method to protect the components from decomposition and applied ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC/TQMS) to quantify aconitine, glucose and digoxin. In addition, ultra-performance liquid chromatography coupled with linear ion trap mass spectrometry (UPLC/ITMS) was applied to detect the potential antidotal components in the RZ extract. Finally, the RZ extract reduced the level of aconitine in everted gut sacs, and eleven gingerols were successfully identified, which could be considered potential antidotal components for aconitine. This study demonstrated the application of two UPLC/MS methods for analyzing the material basis for the reciprocity between Chinese medicine components in everted gut sacs.

  8. Fast and sensitive quantification of human liver cytosolic lithocholic acid sulfation using ultra-high performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Bansal, Sumit; Lau, Aik Jiang

    2016-02-01

    Detoxification of lithocholic acid (LCA) to lithocholic acid sulfate (LCA-S) is catalyzed by sulfotransferases, mainly SULT2A1. We developed and validated an ultra-high performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method to quantify human liver cytosolic-dependent LCA sulfation. Chromatographic separation was achieved on an UPLC C18 column (2.1×50mm, 1.7μm) and a gradient elution of 0.1% formic acid in water and acetonitrile. Negative electrospray ionization with multiple reaction monitoring (MRM) mode was used to quantify LCA-S (455.3→97.0) and cholic acid (407.2→343.3; internal standard). The retention time was 3.51min for LCA-S and 3.08min for cholic acid. The lower limit of quantification of LCA-S was 0.5nM (or 0.23ng/ml in 400μl total volume) and the assay was linear from 0.2 to 200pmol. Intra-day and inter-day accuracy and precision were <14%. The quality control samples were stable at room temperature for 4h, 4°C for 24h, -20°C for 14 days, and after three freeze-thaw cycles. The matrix (20-100μg cytosolic protein) did not affect LCA-S quantification. This is the first UPLC-MS/MS method applied to optimization of the human liver cytosolic LCA sulfation assay. The optimal levels of MgCl2 and 3'-phosphoadenosine 5'-phosphosulfate (PAPS) cofactor were 2.5mM and 20μM, respectively. Addition of reducing agents (2-mercaptoethanol and DL-dithiothreitol) did not affect LCA-S formation. Human liver cytosolic LCA sulfation was linear with 20-100μg of cytosolic protein and 5-30min incubation time. This UPLC-MS/MS approach offers a specific, sensitive, fast, and direct approach for quantifying human liver cytosolic LCA sulfation.

  9. Statistical search space reduction and two-dimensional data display approaches for UPLC-MS in biomarker discovery and pathway analysis.

    PubMed

    Crockford, Derek J; Lindon, John C; Cloarec, Olivier; Plumb, Robert S; Bruce, Stephen J; Zirah, Severine; Rainville, Paul; Stumpf, Chris L; Johnson, Kelly; Holmes, Elaine; Nicholson, Jeremy K

    2006-07-01

    A new analytical strategy for biomarker recovery from directly coupled ultra-performance liquid chromatography time-of-flight mass spectrometry (UPLC Tof MS) data on biofluids is presented and exemplified using a study on hydrazine-induced liver toxicity. A key step in the strategy involves a novel procedure for reducing the spectroscopic search space by differential analysis of cohorts of normal and pathological samples using an orthogonal projection to latent structures discriminant analysis (O-PLS-DA). This efficiently sorts principal discriminators of toxicity from the background of thousands of metabolic features commonly observed in data sets generated by UPLC-MS analysis of biological fluids and is thus a powerful tool for biomarker discovery. PMID:16808447

  10. Identification and quantitation of cocaine, benzoylecgonine, and cocaethylene in blood, serum, and plasma using ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS).

    PubMed

    Kriger, Scott; Gunn, Josh; Terrell, Andrea R

    2010-01-01

    Cocaine is a widely abused stimulant. Numerous methods exist for the identification of the drug, or more commonly, one of its metabolites in urine. Urine testing is useful for most cases, but it is necessary to use other matrices in forensic situations and when subjects are anuric. We describe a novel method for the analysis of cocaine, benzoylecgonine, and cocaethylene in blood, serum, and plasma utilizing ultra-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). Sample preparation has been minimized to a simple deproteinization step in which each specimen is mixed with an acetonitrile-internal standard mixture. The method has excellent precision across the linear range of 25-2,000 ng/mL for each analyte. With a run-time of 4 min, this method provides a significant improvement over traditional GC/MS methods. PMID:20077068

  11. Quantitative analysis of unconjugated and total bisphenol A in human urine using solid-phase extraction and UPLC-MS/MS: method implementation, method qualification and troubleshooting.

    PubMed

    Buscher, Brigitte; van de Lagemaat, Dick; Gries, Wolfgang; Beyer, Dieter; Markham, Dan A; Budinsky, Robert A; Dimond, Stephen S; Nath, Rajesh V; Snyder, Stephanie A; Hentges, Steven G

    2015-11-15

    The aim of the presented investigation was to document challenges encountered during implementation and qualification of a method for bisphenol A (BPA) analysis and to develop and discuss precautions taken to avoid and to monitor contamination with BPA during sample handling and analysis. Previously developed and published HPLC-MS/MS methods for the determination of unconjugated BPA (Markham et al. Journal of Analytical Toxicology, 34 (2010) 293-303) [17] and total BPA (Markham et al. Journal of Analytical Toxicology, 38 (2014) 194-203) [20] in human urine were combined and transferred into another laboratory. The initial method for unconjugated BPA was developed and evaluated in two independent laboratories simultaneously. The second method for total BPA was developed and evaluated in one of these laboratories to conserve resources. Accurate analysis of BPA at sub-ppb levels is a challenging task as BPA is a widely used material and is ubiquitous in the environment at trace concentrations. Propensity for contamination of biological samples with BPA is reported in the literature during sample collection, storage, and/or analysis. Contamination by trace levels of BPA is so pervasive that even with extraordinary care, it is difficult to completely exclude the introduction of BPA into biological samples and, consequently, contamination might have an impact on BPA biomonitoring data. The applied UPLC-MS/MS method was calibrated from 0.05 to 25ng/ml. The limit of quantification was 0.1ng/ml for unconjugated BPA and 0.2ng/ml for total BPA, respectively, in human urine. Finally, the method was applied to urine samples derived from 20 volunteers. Overall, BPA can be analyzed in human urine with acceptable recovery and repeatability if sufficient measures are taken to avoid contamination throughout the procedure from sample collection until UPLC-MS/MS analysis. PMID:26465088

  12. First Detection of Tetrodotoxin in Greek Shellfish by UPLC-MS/MS Potentially Linked to the Presence of the Dinoflagellate Prorocentrum minimum

    PubMed Central

    Vlamis, Aristidis; Katikou, Panagiota; Rodriguez, Ines; Rey, Verónica; Alfonso, Amparo; Papazachariou, Angelos; Zacharaki, Thetis; Botana, Ana M.; Botana, Luis M.

    2015-01-01

    During official shellfish control for the presence of marine biotoxins in Greece in year 2012, a series of unexplained positive mouse bioassays (MBA) for lipophilic toxins with nervous symptomatology prior to mice death was observed in mussels from Vistonikos Bay–Lagos, Rodopi. This atypical toxicity coincided with (a) absence or low levels of regulated and some non-regulated toxins in mussels and (b) the simultaneous presence of the potentially toxic microalgal species Prorocentrum minimum at levels up to 1.89 × 103 cells/L in the area’s seawater. Further analyses by different MBA protocols indicated that the unknown toxin was hydrophilic, whereas UPLC-MS/MS analyses revealed the presence of tetrodotoxins (TTXs) at levels up to 222.9 μg/kg. Reviewing of official control data from previous years (2006–2012) identified a number of sample cases with atypical positive to asymptomatic negative MBAs for lipophilic toxins in different Greek production areas, coinciding with periods of P. minimum blooms. UPLC-MS/MS analysis of retained sub-samples from these cases revealed that TTXs were already present in Greek shellfish since 2006, in concentrations ranging between 61.0 and 194.7 μg/kg. To our knowledge, this is the earliest reported detection of TTXs in European bivalve shellfish, while it is also the first work to indicate a possible link between presence of the toxic dinoflagellate P. minimum in seawater and that of TTXs in bivalves. Confirmed presence of TTX, a very heat-stable toxin, in filter-feeding mollusks of the Mediterranean Sea, even at lower levels to those inducing symptomatology to humans, indicates that this emerging risk should be seriously taken into account by the EU to protect the health of shellfish consumers. PMID:26008234

  13. Preclinical pharmacokinetics, tissue distribution and excretion studies of a novel anti-candidal agent-thiosemicarbazide derivative of isoniazid (TSC-INH) by validated UPLC-MS/MS assay.

    PubMed

    Iqbal, Muzaffar; Ezzeldin, Essam; Bhat, Mashooq A; Raish, Mohammad; Al-Rashood, Khalid A

    2016-01-01

    A simple and sensitive UPLC-MS/MS assay was developed and validated for rapid determination of thiosemicarbazide derivative of isoniazid (TSC-INH), a potent anti-candidal agent in rat plasma, tissues, urine and feces. All biological samples were prepared by protein precipitation method using celecoxib as an internal standard (IS). Chromatographic separation was achieved on Acquity BEH™ C18 (50×2.1 mm, 1.7 μm) column using gradient mobile phase of acetonitrile and water (containing 0.1% formic acid) at flow rate of 0.3 mL/min. The MRM transitions were monitored at m/z 305.00→135.89 for TSC-INH and m/z 380.08→316.03 for IS in ESI negative mode. All validation parameter results were within the acceptable range described in guideline for bioanalytical method validation. The pharmacokinetic study showed that the compound TSC-INH was orally active with 66% absolute bioavailability in rats. It was rapidly absorbed with peak plasma concentration of 1985.92 ng/mL achieved within 1 h after single oral dose (10 mg/kg) administration. TSC-INH exhibited rapid distribution across the body with highest levels in liver and lungs. Penetration in brain tissues suggests that TSC-INH crossed the blood brain barrier. Only 5.23% of the orally administered drug was excreted as unconverted form in urine and feces implying that TSC-INH was metabolized extensively before excretion. With the preliminary knowledge of in vivo pharmacokinetics and disposition properties, this study will be beneficial for further development of compound TSC-INH in future studies.

  14. Development and validation of an UPLC-MS/MS method for the determination of 7-hydroxymitragynine, a μ-opioid agonist, in rat plasma and its application to a pharmacokinetic study

    PubMed Central

    Vuppala, Pradeep K.; Jamalapuram, Seshulatha; Furr, Edward B.; McCurdy, Christopher R.; Avery, Bonnie A.

    2014-01-01

    A simple, sensitive and specific ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method has been developed and validated to determine the concentrations of 7-hydroxymitragynine in rat plasma. Following a single step liquid-liquid extraction of plasma samples using chloroform, 7-hydroxymitragynine and the internal standard (tryptoline) were separated on an Acquity UPLC™ BEH C18 (1.7 μm, 2.1 mm×50 mm) column using an isocratic elution at a flow rate of 0.2 mL/min. The mobile phase consisted of 0.1% acetic acid in water and 0.1% acetic acid in acetonitrile (10:90, v/v). The run was 2.5 min. The analysis was carried out under the multiple reaction-monitoring mode using positive electrospray ionization. Protonated ions [M+H]+ and their respective product ions were monitored at the following transitions: 415>190 for 7-hydroxymitragynine and 173>144 for the internal standard. The calibration curve was linear over the range of 10 to 4000 ng/mL (r2=0.999) with a lower limit of quantification (LLOQ) of 10 ng/mL. The extraction recoveries ranged from 62.0% to 67.3% at concentrations (20, 600, 3200 ng/mL). Intra- and inter-day assay precisions (relative standard deviation) were less than 15% and the accuracy was within 96.5% to 104.0%. This validated method was successfully applied to quantify 7-hydroxymitragynine in rat plasma following intravenous administration. PMID:23893615

  15. Development and validation of a UPLC-MS/MS method for the determination of 7-hydroxymitragynine, a μ-opioid agonist, in rat plasma and its application to a pharmacokinetic study.

    PubMed

    Vuppala, Pradeep K; Jamalapuram, Seshulatha; Furr, Edward B; McCurdy, Christopher R; Avery, Bonnie A

    2013-12-01

    A simple, sensitive and specific ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated to determine the concentrations of 7-hydroxymitragynine in rat plasma. Following a single-step liquid-liquid extraction of plasma samples using chloroform, 7-hydroxymitragynine and the internal standard (tryptoline) were separated on an Acquity UPLC(TM) BEH C18 (1.7 µm, 2.1 × 50 mm) column using an isocratic elution at a flow rate of 0.2 mL/min. The mobile phase consisted of 0.1% acetic acid in water and 0.1% acetic acid in acetonitrile (10:90, v/v). The run time was 2.5 min. The analysis was carried out under the multiple reaction-monitoring mode using positive electrospray ionization. Protonated ions [M + H](+) and their respective product ions were monitored at the following transitions: 415 → 190 for 7-hydroxymitragynine and 173 → 144 for the internal standard. The calibration curve was linear over the range of 10-4000 ng/mL (r(2) = 0.999) with a lower limit of quantification of 10 ng/mL. The extraction recoveries ranged from 62.0 to 67.3% at concentrations of 20, 600 and 3200 ng/mL). Intra- and inter-day assay precisions (relative standard deviation) were <15% and the accuracy was within 96.5-104.0%. This validated method was successfully applied to quantify 7-hydroxymitragynine in rat plasma following intravenous administration. PMID:23893615

  16. Pharmacokinetic comparisons by UPLC-MS/MS of isomer paeoniflorin and albiflorin after oral administration decoctions of single-herb Radix Paeoniae Alba and Zengmian Yiliu prescription to rats.

    PubMed

    Gong, Can; Yang, Hong; Wei, Hai; Qi, Cong; Wang, Chang-Hong

    2015-03-01

    Zengmian Yiliu (ZMYL), a traditional Chinese formula, is designed to improve clinical efficacy and reduce adverse effects in combination with cisplatin in ovarian cancer chemotherapy. In ZMYL, Radix Paeoniae Alba (RPA, made from root of Paeonia lactiflora Pall.) acts as an adjunctive drug in cancer treatment by ameliorating side effects induced by radio- and chemotherapy. The pharmacokinetics differences between isomer albiflorin and paeoniflorin, the main components of RPA, after oral administration decoction of single-herb RPA and ZMYL were compared using a sensitive and accurate UPLC-MS/MS. The results indicate that there are statistically significant differences between the pharmacokinetic parameters: decreasing area under the plasma concentration-time curve (AUC), maximum concentration (Cmax ), elimination rate constant (Ke ) and increasing apparent volume of distribution (Vd ) and clearance (CL) for albiflorin, increasing distribution half-life (T1/2d ) and decreasing elimination half-life (T1/2e ), distribution rate constant (Kd ) and absorption rate constant (Ka ) for paeoniflorin in the ZMYL group compared with the single-herb RPA group. In comparison with albiflorin, the pharmacokinetic parameters of paeoniflorin included significantly increasing mean residence time (MRT) and Vd , decreasing CL and Ke in the single-herb RPA group and increasing MRT and T1/2d and decreasing CL, Ke and Kd in the ZMYL group. Both paeoniflorin and albiflorin are more likely, as the main active ingredients in RPA and ZMYL, to play a variety of pharmacological effects, and herb-herb interactions occur, resulting in different pharmacokinetics of albiflorin and paeoniflorin in RPA and ZMYL.

  17. A UPLC-MS/MS method for simultaneous determination of danshensu, protocatechuic aldehyde, rosmarinic acid, and ligustrazine in rat plasma, and its application to pharmacokinetic studies of Shenxiong glucose injection in rats.

    PubMed

    Zheng, Lin; Gong, Zipeng; Lu, Yuan; Xie, Yumin; Huang, Yong; Liu, Yue; Lan, Yanyu; Wang, Aimin; Wang, Yonglin

    2015-08-01

    A rapid and sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed for the simultaneous determination of the four major active ingredients, danshensu, protocatechuic aldehyde, rosmarinic acid, and ligustrazine, in the traditional Chinese medicine Shenxiong glucose injection in rat plasma. Acidified and alkalized plasma samples were extracted using ethyl acetate, and separated on a Waters C18 column (2.1mm×50mm, 1.7μm) by using a gradient mobile phase system of acetonitrile-water containing 0.1% formic acid and luteoloside as an internal standard. Electrospray ionization in the positive-ion mode and multiple reaction monitoring were used to identify and quantitate the active components. All calibration curves showed good linearity (r>0.994) over the concentration range, with a lower limit of quantification (LLOQ) between 0.02 and 0.21μg/mL. The precision of the in vivo study was evaluated by intra- and inter-day assays, and the percentage of relative standard deviation was within 15%. Moreover, satisfactory extraction efficiency was obtained (between 83.94 and 117.81%) by liquid-liquid extraction. The validated method was successfully applied in a pharmacokinetic study in rats after intravenous administration of Shenxiong glucose injection. The results showed that the four bioactive ingredients in Shenxiong glucose injection have linear pharmacokinetic properties in rats after intravenous injection within the administered dose range and partially different ones compared to single ingredient. PMID:26118621

  18. Simultaneous determination of parecoxib sodium and its active metabolite valdecoxib in rat plasma by UPLC-MS/MS and its application to a pharmacokinetic study after intravenous and intramuscular administration.

    PubMed

    Liu, Meina; Yu, Qiuyang; Li, Ping; Zhu, Meng; Fang, Mingming; Sun, Bingjun; Sun, Mengchi; Sun, Yinghua; Zhang, Peng; He, Zhonggui; Sun, Jin; Wang, Yongjun; Liu, Xiaohong

    2016-06-01

    In this study, we developed and validated a new, rapid, specific and sensitive ultra-performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method to simultaneously determine parecoxib sodium (PX) and its active metabolite, valdecoxib (VX), in rat plasma. Plasma samples were prepared by plasma protein precipitation combined with a liquid-liquid extraction method. The separation was carried out on a Kinetex C18 column (2.1mm×50mm, 2.6μm) with a gradient elution using methanol (A) and a 2mM ammonium acetate aqueous solution (B). The analysis was performed in less than 3min with a flow rate of 0.2mL/min. Ketoprofen was used as an internal standard (IS). Mass spectrometric detection was conducted with a triple quadrupole detector equipped with electrospray ionization in the negative ion mode (ESI(-)) using multiple reaction monitoring (MRM). The calibration curves were linear over the concentration ranges of 5-4000ng/mL for PX and 5-2000ng/mL for VX with all correlation coefficients greater than 0.998. The intra- and inter-day relative standard deviations (RSD) for both analytes were within 15% and the accuracy was within 85-115% at all quality control levels. The mean extraction recoveries for all analytes obtained from three concentrations of QC plasma samples were more than 89.0% efficient. Selectivity, matrix effect, dilution integrity and stability were also validated. The method was successfully used to investigate the pharmacokinetics of PX and VX in rat plasma after intravenous and intramuscular administration of PX. PMID:27107851

  19. Development and application of a UPLC-MS/MS method for simultaneous determination of fenofibric acid and berberine in rat plasma: application to the drug-drug pharmacokinetic interaction study of fenofibrate combined with berberine after oral administration in rats.

    PubMed

    Li, Guofei; Yang, Fan; Liu, Mei; Su, Xianying; Zhao, Mingming; Zhao, Limei

    2016-07-01

    With the purpose of carrying out pharmacokinetic interaction studies ofnberberine (BBR) and fenofibrate (FBT), an UPLC-MS/MS method has been developed and validated. The analytes, BBR and fenofibric acid (FBA, metabolite of FBT) and the internal standard, tetrahydropalmatine, were extracted with dichloromethane-diethyl ether (3:2, v/v) and separated on an Agilent Eclipse XDB C18 column using a mobile phase composed of acetonitrile and water. With positive ion electrospray ionization, the analytes were monitored on a triple quadrupole mass spectrometer in multiple reaction monitoring mode. Linear calibration curves were obtained over the concentration ranges of 0.1-100.0 ng/mL for BBR and 10.0-50,000.0 ng/mL for FBA. For BBR and FBA, the intra- and inter-day precisions were <11.5 and 11.9%, respectively. The accuracy was within 11.7% and 11.3%. The mean recoveries of BBR at three concentrations of 0.2, 20.0, 80.0 ng/mL were >85.6%, and those of FBA at three concentrations of 20.0, 2500.0, 40,000.0 ng/mL were >87.9%. Consequently, the proposed method was applied to the pharmacokinetic interaction study of FBT combined with BBR after oral administration in rats and was proved to be sensitive, specific and reliable to analyze BBR and FBA in biological samples simultaneously. Copyright © 2016 John Wiley & Sons, Ltd.

  20. Pharmacokinetic comparisons by UPLC-MS/MS of isomer paeoniflorin and albiflorin after oral administration decoctions of single-herb Radix Paeoniae Alba and Zengmian Yiliu prescription to rats.

    PubMed

    Gong, Can; Yang, Hong; Wei, Hai; Qi, Cong; Wang, Chang-Hong

    2015-03-01

    Zengmian Yiliu (ZMYL), a traditional Chinese formula, is designed to improve clinical efficacy and reduce adverse effects in combination with cisplatin in ovarian cancer chemotherapy. In ZMYL, Radix Paeoniae Alba (RPA, made from root of Paeonia lactiflora Pall.) acts as an adjunctive drug in cancer treatment by ameliorating side effects induced by radio- and chemotherapy. The pharmacokinetics differences between isomer albiflorin and paeoniflorin, the main components of RPA, after oral administration decoction of single-herb RPA and ZMYL were compared using a sensitive and accurate UPLC-MS/MS. The results indicate that there are statistically significant differences between the pharmacokinetic parameters: decreasing area under the plasma concentration-time curve (AUC), maximum concentration (Cmax ), elimination rate constant (Ke ) and increasing apparent volume of distribution (Vd ) and clearance (CL) for albiflorin, increasing distribution half-life (T1/2d ) and decreasing elimination half-life (T1/2e ), distribution rate constant (Kd ) and absorption rate constant (Ka ) for paeoniflorin in the ZMYL group compared with the single-herb RPA group. In comparison with albiflorin, the pharmacokinetic parameters of paeoniflorin included significantly increasing mean residence time (MRT) and Vd , decreasing CL and Ke in the single-herb RPA group and increasing MRT and T1/2d and decreasing CL, Ke and Kd in the ZMYL group. Both paeoniflorin and albiflorin are more likely, as the main active ingredients in RPA and ZMYL, to play a variety of pharmacological effects, and herb-herb interactions occur, resulting in different pharmacokinetics of albiflorin and paeoniflorin in RPA and ZMYL. PMID:25042570

  1. Chiral PCB 91 and 149 Toxicity Testing in Embryo and Larvae (Danio rerio): Application of Targeted Metabolomics via UPLC-MS/MS

    NASA Astrophysics Data System (ADS)

    Chai, Tingting; Cui, Feng; Yin, Zhiqiang; Yang, Yang; Qiu, Jing; Wang, Chengju

    2016-09-01

    In this study, we aimed to investigate the dysfunction of zebrafish embryos and larvae induced by rac-/(+)-/(‑)- PCB91 and rac-/(‑)-/(+)- PCB149. UPLC-MS/MS (Ultra-performance liquid chromatography coupled with mass spectrometry) was employed to perform targeted metabolomics analysis, including the quantification of 22 amino acids and the semi-quantitation of 22 other metabolites. Stereoselective changes in target metabolites were observed in embryos and larvae after exposure to chiral PCB91 and PCB149, respectively. In addition, statistical analyses, including PCA and PLS-DA, combined with targeted metabolomics were conducted to identify the characteristic metabolites and the affected pathways. Most of the unique metabolites in embryos and larvae after PCB91/149 exposure were amino acids, and the affected pathways for zebrafish in the developmental stage were metabolic pathways. The stereoselective effects of PCB91/149 on the metabolic pathways of zebrafish embryos and larvae suggest that chiral PCB91/149 exposure has stereoselective toxicity on the developmental stages of zebrafish.

  2. Evaluation of the Effects of Ketoconazole and Voriconazole on the Pharmacokinetics of Oxcarbazepine and Its Main Metabolite MHD in Rats by UPLC-MS-MS.

    PubMed

    Chen, Xinxin; Gu, Ermin; Wang, Shuanghu; Zheng, Xiang; Chen, Mengchun; Wang, Li; Hu, Guoxin; Cai, Jian-ping; Zhou, Hongyu

    2016-03-01

    Oxcarbazepine (OXC), a second-generation antiepileptic drug, undergoes rapid reduction with formation of the active metabolite 10,11-dihydro-10-hydroxy-carbazepine (MHD) in vivo. In this study, a method for simultaneous determination of OXC and MHD in rat plasma using ultra-performance liquid chromatography with tandem mass spectrometry (UPLC-MS-MS) was developed and validated. Under given chromatographic conditions, OXC, MHD and internal standard diazepam were separated well and quantified by electrospray positive ionization mass spectrometry in the multiple reaction monitoring transitions mode. The method validation demonstrated good linearity over the range of 10-2,000 ng/mL for OXC and 5-1,000 ng/mL for MHD. The lower limit of quantification was 5 ng/mL for OXC and 2.5 ng/mL for MHD, respectively. The method was successfully applied to the evaluation of the pharmacokinetics of OXC and MHD in rats, with or without pretreatment by ketoconazole (KET) and voriconazole (VOR). Statistics indicated that KET and VOR significantly affected the disposition of OXC and MHD in vivo, whereas VOR predominantly interfered with the disposition of MHD. This method is suitable for pharmacokinetic study in small animals. PMID:26499119

  3. A novel UPLC-MS-MS method for simultaneous determination of seven uremic retention toxins with cardiovascular relevance in chronic kidney disease patients.

    PubMed

    Boelaert, Jente; Lynen, Frédéric; Glorieux, Griet; Eloot, Sunny; Van Landschoot, Maria; Waterloos, Marie-Anne; Sandra, Pat; Vanholder, Raymond

    2013-02-01

    Chronic kidney disease (CKD) is a devastating illness characterized by accumulation of uremic retention solutes in the body. The objective of this study was to develop and validate a simple, rapid, and robust UPLC-MS-MS method for simultaneous determination, in serum, of seven organic acid uremic retention toxins, namely uric acid (UA), hippuric acid (HA), indoxylsulfate (IS), p-cresylglucuronide (pCG), p-cresylsulfate (pCS), indole-3-acetic acid (IAA), and 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (CMPF). Isotopically labeled internal standards (d(5)-HA; 1,3-(15)N(2)-UA, and d(5)-IAA) were used to correct for variations in sample preparation and system performance. Separation on a C18 column was followed by negative electrospray ionization and tandem mass spectrometric detection. Accuracy was below the 15 % threshold. Within-day precision varied from 0.60 to 4.54 % and between-day precision was below 13.33 % for all compounds. The applicability of the method was evaluated by analyzing 78 serum samples originating both from healthy controls and from patients at different stages of CKD. These results were compared with those obtained by use of conventional HPLC-PDA-FLD methods. A good correlation was obtained between both methods for all compounds. PMID:23307120

  4. Simultaneous Determination of Typhaneoside and Isorhamnetin-3-O-Neohesperidoside in Rats After Oral Administration of Pollen Typhae Extract by UPLC-MS/MS.

    PubMed

    Cao, Sali; Ni, Boran; Feng, Lijun; Yin, Xingbin; Dou, Haoran; Fu, Jing; Lin, Longfei; Ni, Jian

    2015-07-01

    For the first time, a selective and rapid ultra-performance liquid chromatography method with tandem mass spectrometric (UPLC-MS/MS) detection for simultaneous determination of typhaneoside and isorhamnetin-3-O-neohesperidoside in rat plasma was developed and validated, which was applied to the pharmacokinetic study of Pollen Typhae extract. The separation was carried out on an ACQUITY UPLC(TM) BEH C18 column with gradient elution using mobile phase including acetonitrile and water (containing 0.1% formic acid). The flow rate was 0.4 mL/min. The detection was conducted by means of electrospray ionization mass spectrometry in negative ion mode with multiple reaction monitoring. The assays were linear over the concentration range of 0.5-100 ng/mL, and the lower limit of quantification was 0.5 ng/mL for typhaneoside and isorhamnetin-3-O-neohesperidoside. The method was validated in terms of intra- and interday precision (<9.37%), accuracy (within ±10.91%), linearity, specificity and stability, and has been successfully applied to a pharmacokinetic study of Pollen Typhae extract in rats after oral administration.

  5. Chiral PCB 91 and 149 Toxicity Testing in Embryo and Larvae (Danio rerio): Application of Targeted Metabolomics via UPLC-MS/MS

    PubMed Central

    Chai, Tingting; Cui, Feng; Yin, Zhiqiang; Yang, Yang; Qiu, Jing; Wang, Chengju

    2016-01-01

    In this study, we aimed to investigate the dysfunction of zebrafish embryos and larvae induced by rac-/(+)-/(−)- PCB91 and rac-/(−)-/(+)- PCB149. UPLC-MS/MS (Ultra-performance liquid chromatography coupled with mass spectrometry) was employed to perform targeted metabolomics analysis, including the quantification of 22 amino acids and the semi-quantitation of 22 other metabolites. Stereoselective changes in target metabolites were observed in embryos and larvae after exposure to chiral PCB91 and PCB149, respectively. In addition, statistical analyses, including PCA and PLS-DA, combined with targeted metabolomics were conducted to identify the characteristic metabolites and the affected pathways. Most of the unique metabolites in embryos and larvae after PCB91/149 exposure were amino acids, and the affected pathways for zebrafish in the developmental stage were metabolic pathways. The stereoselective effects of PCB91/149 on the metabolic pathways of zebrafish embryos and larvae suggest that chiral PCB91/149 exposure has stereoselective toxicity on the developmental stages of zebrafish. PMID:27629264

  6. Determination of cyanidin 3-glucoside in rat brain, liver and kidneys by UPLC/MS-MS and its application to a short-term pharmacokinetic study

    PubMed Central

    Fornasaro, Stefano; Ziberna, Lovro; Gasperotti, Mattia; Tramer, Federica; Vrhovšek, Urška; Mattivi, Fulvio; Passamonti, Sabina

    2016-01-01

    Anthocyanins exert neuroprotection in various in vitro and in vivo experimental models. However, no details regarding their brain-related pharmacokinetics are so far available to support claims about their direct neuronal bioactivity as well as to design proper formulations of anthocyanin-based products. To gather this missing piece of knowledge, we intravenously administered a bolus of 668 nmol cyanidin 3-glucoside (C3G) in anaesthetized Wistar rats and shortly after (15 s to 20 min) we collected blood, brain, liver, kidneys and urine samples. Extracts thereof were analysed for C3G and its expected metabolites using UPLC/MS-MS. The data enabled to calculate a set of pharmacokinetics parameters. The main finding was the distinctive, rapid distribution of C3G in the brain, with an apparently constant plasma/brain ratio in the physiologically relevant plasma concentration range (19–355 nM). This is the first report that accurately determines the distribution pattern of C3G in the brain, paving the way to the rational design of future tests of neuroprotection by C3G in animal models and humans. PMID:26965389

  7. Chiral PCB 91 and 149 Toxicity Testing in Embryo and Larvae (Danio rerio): Application of Targeted Metabolomics via UPLC-MS/MS.

    PubMed

    Chai, Tingting; Cui, Feng; Yin, Zhiqiang; Yang, Yang; Qiu, Jing; Wang, Chengju

    2016-01-01

    In this study, we aimed to investigate the dysfunction of zebrafish embryos and larvae induced by rac-/(+)-/(-)- PCB91 and rac-/(-)-/(+)- PCB149. UPLC-MS/MS (Ultra-performance liquid chromatography coupled with mass spectrometry) was employed to perform targeted metabolomics analysis, including the quantification of 22 amino acids and the semi-quantitation of 22 other metabolites. Stereoselective changes in target metabolites were observed in embryos and larvae after exposure to chiral PCB91 and PCB149, respectively. In addition, statistical analyses, including PCA and PLS-DA, combined with targeted metabolomics were conducted to identify the characteristic metabolites and the affected pathways. Most of the unique metabolites in embryos and larvae after PCB91/149 exposure were amino acids, and the affected pathways for zebrafish in the developmental stage were metabolic pathways. The stereoselective effects of PCB91/149 on the metabolic pathways of zebrafish embryos and larvae suggest that chiral PCB91/149 exposure has stereoselective toxicity on the developmental stages of zebrafish. PMID:27629264

  8. Determination of six Alternaria toxins with UPLC-MS/MS and their occurrence in tomatoes and tomato products from the Swiss market.

    PubMed

    Noser, Jürg; Schneider, Patrick; Rother, Martin; Schmutz, Hansruedi

    2011-11-01

    An ultra performance liquid chromatography (UPLC)-tandem mass spectrometry (MS/MS) method was developed for the determination of the Alternaria toxins tenuazonic acid, alternariol, alternariol monomethyl ether, altenuene, altertoxin I and tentoxin. Owing to its instability, altenusin could not be determined. The sample preparation includes an acidic acetonitrile/water/methanol extraction, followed by SPE clean-up step, before injection into the UPLC-MS/MS system. The separation was made on an Acquity UPLC column using a water/acetonitrile gradient with ammonium hydrogen carbonate as a modifier. Matrix compounds of real samples led to enhancement as well as suppression of the target compounds, depending on analyte and matrix. The recoveries were between 58 and 109% at a level of 10 μg/kg. Eighty-five tomato products, consisting of peeled and minced tomatoes, soup and sauces, tomato purées and concentrates, ketchup as well as dried and fresh tomatoes, were taken from the Swiss market in 2010. Tenuazonic acid was found most frequently (81 out of 85 samples) and in the highest levels of up to 790 μg/kg. Alternariol and alternariol monomethyl ether were found in lower concentrations, ranging from <1 to 33 μg/kg for alternariol and <5 to 9 μg/kg for alternariol monomethyl ether. Only a few samples were positive for altenuene and tentoxin. Altertoxin I was never detected. PMID:23605928

  9. Analysis of ecologically relevant pharmaceuticals in wastewater and surface water using selective solid phase extraction and UPLC/MS/MS

    EPA Science Inventory

    A rapid and sensitive method has been developed for the analysis of 48 human prescription active pharmaceutical ingredients (APIs) and 6 metabolites of interest, utilizing selective solid-phase extraction (SPE) and ultra performance liquid chromatography in combination with tripl...

  10. Development of a multiple immunoaffinity column for simultaneous determination of multiple mycotoxins in feeds using UPLC-MS/MS.

    PubMed

    Hu, Xiaofeng; Hu, Rui; Zhang, Zhaowei; Li, Peiwu; Zhang, Qi; Wang, Min

    2016-09-01

    A sensitive and specific immunoaffinity column to clean up and isolate multiple mycotoxins was developed along with a rapid one-step sample preparation procedure for ultra-performance liquid chromatography-tandem mass spectrometry analysis. Monoclonal antibodies against aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, zearalenone, ochratoxin A, sterigmatocystin, and T-2 toxin were coupled to microbeads for mycotoxin purification. We optimized a homogenization and extraction procedure as well as column loading and elution conditions to maximize recoveries from complex feed matrices. This method allowed rapid, simple, and simultaneous determination of mycotoxins in feeds with a single chromatographic run. Detection limits for these toxins ranged from 0.006 to 0.12 ng mL(-1), and quantitation limits ranged from 0.06 to 0.75 ng mL(-1). Concentration curves were linear from 0.12 to 40 μg kg(-1) with correlation coefficients of R (2) > 0.99. Intra-assay and inter-assay comparisons indicated excellent repeatability and reproducibility of the multiple immunoaffinity columns. As a proof of principle, 80 feed samples were tested and several contained multiple mycotoxins. This method is sensitive, rapid, and durable enough for multiple mycotoxin determinations that fulfill European Union and Chinese testing criteria. PMID:27225172

  11. Method development for quantification of the environmental neurotoxin annonacin in Rat plasma by UPLC-MS/MS and application to a pharmacokinetic study.

    PubMed

    Bonneau, Natacha; Schmitz-Afonso, Isabelle; Brunelle, Alain; Touboul, David; Champy, Pierre

    2015-11-01

    Annonacin is an environmental neurotoxin identified in the pulp of several fruits of the Annonaceae family (for example in Annona muricata, Asimina triloba), whose consumption was linked with the occurrence of sporadic atypical Parkinsonism with dementia. Pharmacokinetic parameters of this molecule are unknown. A method for its quantification in Rat plasma was developed, using its analogue annonacinone as an internal standard. Extraction from plasma was performed using ethylacetate with a good recovery. Quantification was performed by UPLC-MS/MS in SRM mode, based on the loss of the γ-methyl-γ-lactone (-112amu) from the sodium-cationized species [M+Na](+) of both annonacin and internal standard. The limit of quantification was 0.25ng/mL. Despite strong matrix effects, a good linearity was obtained over two distinct ranges 0.25-10ng/mL and 10-100ng/mL. The intra- and inter-day precisions (RSD) were lower than 10%, while accuracy was within ±10%. This method was applied to a pharmacokinetic study in the Rat. After oral administration of 10mg/kg annonacin, a Cmax of 7.9±1.5ng/mL was reached at Tmax 0.25h; T1/2 was 4.8±0.7h and apparent distribution volume was 387.9±64.6L. The bioavailability of annonacin was estimated to be 3.2±0.3% of the ingested dose.

  12. A UPLC/MS-based metabolomics investigation of the protective effect of ginsenosides Rg1 and Rg2 in mice with Alzheimer's disease

    PubMed Central

    Li, Naijing; Liu, Ying; Li, Wei; Zhou, Ling; Li, Qing; Wang, Xueqing; He, Ping

    2015-01-01

    Background Alzheimer's disease (AD) is a progressive brain disease, for which there is no effective drug therapy at present. Ginsenoside Rg1 (G-Rg1) and G-Rg2 have been reported to alleviate memory deterioration. However, the mechanism of their anti-AD effect has not yet been clearly elucidated. Methods Ultra performance liquid chromatography tandem MS (UPLC/MS)-based metabolomics was used to identify metabolites that are differentially expressed in the brains of AD mice with or without ginsenoside treatment. The cognitive function of mice and pathological changes in the brain were also assessed using the Morris water maze (MWM) and immunohistochemistry, respectively. Results The impaired cognitive function and increased hippocampal Aβ deposition in AD mice were ameliorated by G-Rg1 and G-Rg2. In addition, a total of 11 potential biomarkers that are associated with the metabolism of lysophosphatidylcholines (LPCs), hypoxanthine, and sphingolipids were identified in the brains of AD mice and their levels were partly restored after treatment with G-Rg1 and G-Rg2. G-Rg1 and G-Rg2 treatment influenced the levels of hypoxanthine, dihydrosphingosine, hexadecasphinganine, LPC C 16:0, and LPC C 18:0 in AD mice. Additionally, G-Rg1 treatment also influenced the levels of phytosphingosine, LPC C 13:0, LPC C 15:0, LPC C 18:1, and LPC C 18:3 in AD mice. Conclusion These results indicate that the improvements in cognitive function and morphological changes produced by G-Rg1 and G-Rg2 treatment are caused by regulation of related brain metabolic pathways. This will extend our understanding of the mechanisms involved in the effects of G-Rg1 and G-Rg2 on AD. PMID:26843817

  13. UPLC-MS-MS Method for the Determination of Vilazodone in Human Plasma: Application to a Pharmacokinetic Study.

    PubMed

    El-Bagary, Ramzia; Hashem, Hanaa; Fouad, Marwa; Tarek, Sally

    2016-09-01

    A sensitive, rapid and simple liquid chromatographic-electrospray ionization tandem mass spectrometric (LC-ESI-MS-MS) method was developed for the quantitative determination of vilazodone in human plasma and for the study of the pharmacokinetic behavior of vilazodone in healthy Egyptian volunteers. With escitalopram as internal standard (IS), liquid-liquid extraction was used for the purification and preconcentration of analytes from human plasma matrix using diethyl ether. The separation was performed on an Acquity UPLC BEH shield RP C18 column (1.7 µm, 2.1 × 150 mm). Isocratic elution was applied using methanol-0.2% formic acid (90:10, v/v). Detection was performed on a triple-quadrupole tandem mass spectrometer with multiple reaction monitoring mode via an electrospray ionization source at m/z 442.21 → 155.23 for vilazodone and m/z 325.14 → 109.2 for escitalopram. Linear calibration curves were obtained over the range of 1-200 ng/mL with the lower limit of quantification at 1 ng/mL. The intra- and inter-day precision showed relative standard deviation ≤3.3%. The total run time was 1.5 min. This method was successfully applied for clinical pharmacokinetic investigation, and a preliminary metabolic study was also carried out. PMID:27209054

  14. Determination and validation of chikusetsusaponin IVa in rat plasma by UPLC-MS/MS and its application to pharmacokinetic study.

    PubMed

    Wang, Ying; Liu, Shi-Ping; Guo, Mei-Hua; Wang, Zhuo

    2016-09-01

    A novel, sensitive and rapid ultra-performance liquid chromatography-tandem mass spectrometric method for the quantification of chikusetsusaponin IVa (CHS-IVa) in rat plasma was established and validated. Plasma samples were pre-treated by precipitation of protein with acetonitrile and chromatographed on a Waters Symmetry C18 analytical column (4.6 × 50 mm, i.d., 3.5 μm) using a mobile phase consisting of methanol and water containing 0.05% formic acid (55:45, v/v) at a flow rate of 0.4 mL/min. The deprotonated molecular ions [M - H](-) were employed in electrospray negative ionization mode and selected reaction monitoring transitions were performed for detection. The calibration curves exhibited good linearity (r > 0.99) over the range of 0.5-1000 ng/mL for CHS-IVa. The recoveries of CHS-IVa were >92.5% and exhibited no severe matrix effect. This method was successfully applied in the pharmacokinetic study of CHS-IVa in rats. For oral administration, the plasma concentrations of CHS-IVa increased to a peak value at 0.35 ± 0.14 h, followed by a gradual decrease to the lower limit of quantitation in 24 h. For intravenous administration, the plasma concentrations of CHS-IVa decreased quickly (t1/2 , 1.59 ± 0.25 h). The absolute bioavailability of CHS-IVa in rats was 8.63%. Copyright © 2016 John Wiley & Sons, Ltd.

  15. UPLC-MS-ELSD-PDA as a powerful dereplication tool to facilitate compound identification from small molecule natural product libraries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Generation of natural product libraries containing column fractions, each with only a few small molecules, by a high throughput, automated fractionation system has made it possible to implement an improved dereplication strategy for selection and prioritization of hits in a natural product discovery...

  16. Distribution and persistence of cephalosporins in cephalosporin producing wastewater using SPE and UPLC-MS/MS method.

    PubMed

    Yu, Xin; Tang, Xinyao; Zuo, Jiane; Zhang, Mengyu; Chen, Lei; Li, Zaixing

    2016-11-01

    An investigation to study the distribution and persistence of cephalosporins in the cephalosporin producing wastewater was carried out in this paper. The target cephalosporins included ceftriaxone (CRO), cefalexin (CEF), cefotaxime (CTX), cefazolin (CZO), cefuroxime (CXM), cefoxitin (CFX) and cefradine (CF). A rapid and reliable detection method for cephalosporins was established based on solid phase extraction and ultra-performance liquid chromatography - tandem mass spectrometry. In the cephalosporin producing wastewater effluent (CPWWeff), the limit of quantification for the targets ranged from 27.5ng/L to 131.8ng/L, and the recoveries for all of the analytes ranged from 73% to 102%. The mean concentrations of the seven cephalosporins were 12.85-141.55μg/L and 0.05-24.38μg/L in cephalosporin producing wastewater influent and effluent, respectively. Although high removal efficiencies were achieved for the cephalosporins (78.8-99.7%), up to 1.9kg of cephalosporins was discharged per day from the investigated C-WWTP. The degradation processes of CRO, CEF, CZO and CXM followed first-order kinetics in CPWWeff under all of the testing conditions. The degradation rates of tested cephalosporins were accelerated by high temperature and light. Persistence of CXM was the highest among the four tested cephalosporins in CPWWeff. PMID:27328396

  17. Assessment of nicotine for second hand smoke exposure in some public places in Romania by UPLC-MS

    PubMed Central

    2014-01-01

    Background Air nicotine monitoring is a well-known procedure for estimation of exposure to second hand smoke. Few research studies were realized in Romania to evaluate environmental tobacco smoke (ETS) exposure of humans in different public places. The levels of airborne nicotine from environmental tobacco smoke and urinary cotinine and nicotine levels of some subjects were analyzed. In order to better implement/enforce the European legislation regarding the interdiction of smoking in the public places the national authorities need a rapid and reliable analytical method to quickly asses the state of the pollution with cigarette smoke of these populated areas. Results The nicotine concentration in the air from different types of public buildings was determined. The median concentration of nicotine in the air from 32 pubs where the smoking was allowed was 590 ng · L-1, comparing with the pubs where the smoking was not permitted (22 locations) where the median concentration of nicotine was only 32 ng · L-1. Similarly, the median concentration of nicotine in restaurants where the smoking was allowed (23 locations) was 510 ng · L-1, in comparison with the restaurants where the smoking was prohibited (11 places) where the median value was 19 ng · L-1. The lowest concentrations of nicotine were found in high schools (8 locations, median concentration 7.4 ng · L-1), universities (5 locations, 23 ng · L-1) and hospitals (6 locations, 16 ng · L-1). Conclusions The method was validated and gave good linearity, precision, accuracy and limit of detection. The buildings included hospitals, high schools, universities, pubs and restaurants. The presence of air nicotine was recorded in all buildings studied. The highest median levels of air nicotine were found in pubs and restaurants. The presence of air nicotine in indoor public buildings indicates weak implementation of the smoke free law in Romania. PMID:24839459

  18. Separation and identification of diarylheptanoids in supercritical fluid extract of Alpinia officinarum by UPLC-MS-MS.

    PubMed

    Luo, Jingchao; Rui, Wen; Jiang, Miaomiao; Tian, Qinglong; Ji, Xing; Feng, Yifan

    2010-11-01

    In the present study, ultra-performance liquid chromatography (UPLC) coupled to electrospray ionization (ESI(+)) tandem mass spectrometry (MS) was developed to identify and characterize the diarylheptanoids in the supercritical fluid extract (SFE) of Alpinia officinarum. The method established provides good reproducibility of UPLC and shows high precision with all the mass accuracy of less than 5 ppm. The ESI-MS-MS fragmentation behavior of every group and their appropriate characteristic pathways were proposed. On the basis of analyzing the fragmentation pathways, elemental composition provided by software Masslynx, mass data of the standard compounds and the information regarding polarity obtained from retention time data, in all, 23 diarylheptanods were characterized. All of them have been reported in Alpinia officinarum. They were classified into six distinct groups (homologous series). Compared to the references, the fragmentation pathways of the first and second group were detailed much more and complementary. Further more, the fragmentation pathways of the last four groups were firstly discussed. The fragmentation rules deduced and the data provided could aid in the characterization of other diarylheptanoids of these types and would be useful for the further research of diarylheptanoids in Alpinia officinarum or the other plants.

  19. Validation and application of an UPLC-MS/MS method for the quantification of synthetic cannabinoids in urine samples and analysis of seized materials from the Portuguese market.

    PubMed

    Simões, Susana Sadler; Silva, Inês; Ajenjo, Antonio Castañera; Dias, Mário João

    2014-10-01

    An UPLC-MS/MS method using ESI+ionization and MRM was developed and fully validated according to international guidelines for the qualitative and quantitative analysis of nine synthetic cannabinoids and/or their metabolites in urine samples (1mL). Prior to extraction the samples were subjected to an enzymatic hydrolysis using β-glucuronidase followed by a SPE procedure using Oasis(®) HLB 3cc (60mg) columns. The chromatographic separation was performed with an Acquity UPLC(®) HSS T3 (50mm×2.1mm i.d., 1.8μm) reversed-phase column using a gradient with methanol-ammonium formate 2mM (0.1% formic acid) and with a run time of 9.5min. The method was validated in terms of selectivity, capacity of identification, limits of detection (0.01-0.5ng/mL) and quantification (0.05-0.5ng/mL), recovery (58-105%), carryover, matrix effect, linearity (0.05-50ng/mL), intra-assay precision, inter-assay accuracy and precision (CV<20%). The method was applied to 80 authentic samples, five of them (6.2%) were confirmed or suspected to be positive for the metabolites JWH-018 N-hydroxypentyl and JWH-018 N-pentanoic acid of JWH-018 and for the metabolite JWH-122 N-(5-hydroxypentyl) of JWH-122, and three of them in association with THC and/or THCCOOH (substances included in the method, together with the 11-OH-THC). Additionally, 17 spice products were analyzed, for which were confirmed the presence of the following substances: AM-2201, JWH-018, JWH-022 JWH-073, JWH-122, JWH-203, JWH-210, JWH-250, HU-210 and RCS-4, according to the comparison with authentic reference material and published data. The analytical method developed allowed the analysis of synthetic cannabinoids and the notification of the first cases in Portugal. PMID:25127518

  20. Validation and application of an UPLC-MS/MS method for the quantification of synthetic cannabinoids in urine samples and analysis of seized materials from the Portuguese market.

    PubMed

    Simões, Susana Sadler; Silva, Inês; Ajenjo, Antonio Castañera; Dias, Mário João

    2014-10-01

    An UPLC-MS/MS method using ESI+ionization and MRM was developed and fully validated according to international guidelines for the qualitative and quantitative analysis of nine synthetic cannabinoids and/or their metabolites in urine samples (1mL). Prior to extraction the samples were subjected to an enzymatic hydrolysis using β-glucuronidase followed by a SPE procedure using Oasis(®) HLB 3cc (60mg) columns. The chromatographic separation was performed with an Acquity UPLC(®) HSS T3 (50mm×2.1mm i.d., 1.8μm) reversed-phase column using a gradient with methanol-ammonium formate 2mM (0.1% formic acid) and with a run time of 9.5min. The method was validated in terms of selectivity, capacity of identification, limits of detection (0.01-0.5ng/mL) and quantification (0.05-0.5ng/mL), recovery (58-105%), carryover, matrix effect, linearity (0.05-50ng/mL), intra-assay precision, inter-assay accuracy and precision (CV<20%). The method was applied to 80 authentic samples, five of them (6.2%) were confirmed or suspected to be positive for the metabolites JWH-018 N-hydroxypentyl and JWH-018 N-pentanoic acid of JWH-018 and for the metabolite JWH-122 N-(5-hydroxypentyl) of JWH-122, and three of them in association with THC and/or THCCOOH (substances included in the method, together with the 11-OH-THC). Additionally, 17 spice products were analyzed, for which were confirmed the presence of the following substances: AM-2201, JWH-018, JWH-022 JWH-073, JWH-122, JWH-203, JWH-210, JWH-250, HU-210 and RCS-4, according to the comparison with authentic reference material and published data. The analytical method developed allowed the analysis of synthetic cannabinoids and the notification of the first cases in Portugal.

  1. A New Method to Quantify Ifosfamide Blood Levels Using Dried Blood Spots and UPLC-MS/MS in Paediatric Patients with Embryonic Solid Tumours.

    PubMed

    Torres, Luz-María; Rivera-Espinosa, Liliana; Chávez-Pacheco, Juan L; Navas, Carlos F; Demetrio, Joel A; Alemón-Medina, Radamés; Trujillo, Francisca; Pérez, Martín; Zapata, Martha M; Cárdenas, Rocío; Salinas, Citlaltepetl; Aquino, Arnoldo; Velázquez-Cruz, Rafael; Castillejos, Manuel-de-Jesús

    2015-01-01

    Ifosfamide blood concentrations are necessary to monitor its therapeutic response, avoiding any adverse effect. We developed and validated an analytical method by UPLC-MS/MS to quantify ifosfamide in dried blood spots (DBS). Blood samples were collected on Whatman 903® filter paper cards. Five 3 mm disks were punched out from each dried blood spot. Acetonitrile and ethyl acetate were used for drug extraction. Chromatographic separation was carried out in an Acquity UPLC equipment with a BEH-C18 column, 2.1 x 100 mm, 1.7 μm (Waters®). The mobile phase consisted in 5 mM ammonium formate and methanol:acetonitrile (40:48:12 v/v/v) at 0.2 mL/min. LC-MS/MS detection was done by ESI+ and multiple reaction mode monitoring, ionic transitions were m/z1+ 260.99 > 91.63 for ifosfamide and 261.00 > 139.90 for cyclophosphamide (internal standard). This method was linear within a 100-10000 ng/mL range and it was accurate, precise and selective. Ifosfamide samples in DBS were stable for up to 52 days at -80°C. The procedure was tested in 14 patients, ages 1 month to 17 years (9 males and 5 females), with embryonic tumours treated with ifosfamide, alone or combined, at a public tertiary referral hospital. Ifosfamide blood levels ranged from 11.1 to 39.7 μmol/L at 12 hours after the last infusion, while 24-hour levels ranged from 0.7-19.7 μmol/L. The median at 12 hours was 19.5 μmol/L (Q25 14.4-Q75 29.0) and 3.8 μmol/L (Q25 1.5-Q75 9.9) at 24 hours, p<0.001. This method is feasible to determine ifosfamide plasma levels in paediatric patients.

  2. A New Method to Quantify Ifosfamide Blood Levels Using Dried Blood Spots and UPLC-MS/MS in Paediatric Patients with Embryonic Solid Tumours

    PubMed Central

    Chávez-Pacheco, Juan L.; Navas, Carlos F.; Demetrio, Joel A.; Alemón-Medina, Radamés; Trujillo, Francisca; Pérez, Martín; Zapata, Martha M.; Cárdenas, Rocío; Salinas, Citlaltepetl; Aquino, Arnoldo; Velázquez-Cruz, Rafael; Castillejos, Manuel-de-Jesús

    2015-01-01

    Ifosfamide blood concentrations are necessary to monitor its therapeutic response, avoiding any adverse effect. We developed and validated an analytical method by UPLC-MS/MS to quantify ifosfamide in dried blood spots (DBS). Blood samples were collected on Whatman 903® filter paper cards. Five 3 mm disks were punched out from each dried blood spot. Acetonitrile and ethyl acetate were used for drug extraction. Chromatographic separation was carried out in an Acquity UPLC equipment with a BEH-C18 column, 2.1 x 100 mm, 1.7 μm (Waters®). The mobile phase consisted in 5 mM ammonium formate and methanol:acetonitrile (40:48:12 v/v/v) at 0.2 mL/min. LC-MS/MS detection was done by ESI+ and multiple reaction mode monitoring, ionic transitions were m/z1+ 260.99 > 91.63 for ifosfamide and 261.00 > 139.90 for cyclophosphamide (internal standard). This method was linear within a 100–10000 ng/mL range and it was accurate, precise and selective. Ifosfamide samples in DBS were stable for up to 52 days at -80°C. The procedure was tested in 14 patients, ages 1 month to 17 years (9 males and 5 females), with embryonic tumours treated with ifosfamide, alone or combined, at a public tertiary referral hospital. Ifosfamide blood levels ranged from 11.1 to 39.7 μmol/L at 12 hours after the last infusion, while 24-hour levels ranged from 0.7–19.7 μmol/L. The median at 12 hours was 19.5 μmol/L (Q25 14.4–Q75 29.0) and 3.8 μmol/L (Q25 1.5–Q75 9.9) at 24 hours, p<0.001. This method is feasible to determine ifosfamide plasma levels in paediatric patients. PMID:26600181

  3. High-Sensitivity Spectrophotometry.

    ERIC Educational Resources Information Center

    Harris, T. D.

    1982-01-01

    Selected high-sensitivity spectrophotometric methods are examined, and comparisons are made of their relative strengths and weaknesses and the circumstances for which each can best be applied. Methods include long path cells, noise reduction, laser intracavity absorption, thermocouple calorimetry, photoacoustic methods, and thermo-optical methods.…

  4. Human liver cytosolic sulfotransferase 2A1-dependent dehydroepiandrosterone sulfation assay by ultra-high performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Bansal, Sumit; Lau, Aik Jiang

    2016-02-20

    Sulfotransferase 2A1 (SULT2A1) is a major catalyst of the sulfation of dehydroepiandrosterone (DHEA) to dehydroepiandrosterone sulfate (DHEA-S) in human liver cytosol. However, there is a lack of a sensitive and fast analytical method for the human liver cytosolic SULT2A1-dependent DHEA sulfation assay. Therefore, we developed and validated an ultra-high performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method to quantify DHEA-S and used it to optimize the human liver cytosolic SULT2A1-dependent DHEA sulfation assay. DHEA-S and cortisol (internal standard) eluted at 2.95 and 2.75min, respectively. Negative multiple reaction monitoring was used to quantify DHEA-S (m/z 367.3→97.0) and cortisol (m/z 407.2→331.3). No interfering peaks were observed in blank samples. The lower limit of quantification was 0.2pmol DHEA-S and the calibration curve was linear from 0.2 to 200pmol. The intra-day and inter-day accuracy and precision was <11.7%. DHEA-S in the quality control samples was stable at room temperature, 4°C, and -20°C. The cytosolic matrix (20-100μg cytosolic protein) did not affect DHEA-S quantification. Our UPLC-MS/MS method was applied to optimize the human liver cytosolic SULT2A1-dependent DHEA sulfation assay. The optimal levels of MgCl2 and 3'-phosphoadenosine 5'-phosphosulfate (PAPS) cofactor were 2.5mM and 20μM, respectively. Reducing agents, including 2-mercaptoethanol and DL-dithiothreitol, did not affect the enzyme activity. A linear relationship existed between DHEA sulfation and amount of human liver cytosol (20-200μg cytosolic protein) or incubation time (5-30min). This UPLC-MS/MS approach is safer, easier, and faster than existing radiometric-based sulfotransferase enzyme assays, and it is the first UPLC-MS/MS method for determining SULT2A1-dependent DHEA sulfation in human liver cytosol.

  5. Human liver cytosolic sulfotransferase 2A1-dependent dehydroepiandrosterone sulfation assay by ultra-high performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Bansal, Sumit; Lau, Aik Jiang

    2016-02-20

    Sulfotransferase 2A1 (SULT2A1) is a major catalyst of the sulfation of dehydroepiandrosterone (DHEA) to dehydroepiandrosterone sulfate (DHEA-S) in human liver cytosol. However, there is a lack of a sensitive and fast analytical method for the human liver cytosolic SULT2A1-dependent DHEA sulfation assay. Therefore, we developed and validated an ultra-high performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method to quantify DHEA-S and used it to optimize the human liver cytosolic SULT2A1-dependent DHEA sulfation assay. DHEA-S and cortisol (internal standard) eluted at 2.95 and 2.75min, respectively. Negative multiple reaction monitoring was used to quantify DHEA-S (m/z 367.3→97.0) and cortisol (m/z 407.2→331.3). No interfering peaks were observed in blank samples. The lower limit of quantification was 0.2pmol DHEA-S and the calibration curve was linear from 0.2 to 200pmol. The intra-day and inter-day accuracy and precision was <11.7%. DHEA-S in the quality control samples was stable at room temperature, 4°C, and -20°C. The cytosolic matrix (20-100μg cytosolic protein) did not affect DHEA-S quantification. Our UPLC-MS/MS method was applied to optimize the human liver cytosolic SULT2A1-dependent DHEA sulfation assay. The optimal levels of MgCl2 and 3'-phosphoadenosine 5'-phosphosulfate (PAPS) cofactor were 2.5mM and 20μM, respectively. Reducing agents, including 2-mercaptoethanol and DL-dithiothreitol, did not affect the enzyme activity. A linear relationship existed between DHEA sulfation and amount of human liver cytosol (20-200μg cytosolic protein) or incubation time (5-30min). This UPLC-MS/MS approach is safer, easier, and faster than existing radiometric-based sulfotransferase enzyme assays, and it is the first UPLC-MS/MS method for determining SULT2A1-dependent DHEA sulfation in human liver cytosol. PMID:26760244

  6. [Determination of di (hydrogenated tallow alkyl) dimethyl ammonium compounds in textile auxiliaries by ultra-high performance liquid chromatography-tandem mass spectrometry].

    PubMed

    Zhu, Feng

    2015-01-01

    A method has been developed for the determination of di (hydrogenated tallow alkyl) dimethyl ammonium compounds (DHTDMAC) in textile auxiliaries by ultra-high performance liquid chromatography-tandem mass spectrometry. (UPLC-MS/MS). The samples were extracted and diluted with acidified methanol by 5% (v/v) formic acid under ultrasonic assistance. The separation was performed on an Eclipse Plus C18 column (50 mm x 2.1 mm, 1.8 microm) using 0.1% (v/v) formic acid solution and methanol as the mobile phases. Identification and quantification were achieved by UPLC-MS/MS with electrospray ionization (ESI) source in positive ion mode and multiple reaction monitoring (MRM) mode. The results indicated that the calibration curve of DHTDMAC showed good linear relationship between peak area and mass concentration in the range of 10-280 microg/L with the correlation coefficient (r2) of 0.9991. The limit of detection (LOD, S/N=3) and the limit of quantification (LOQ, S/N= 10) of this method were 3 mg/kg and 10 mg/kg, respectively. The average recoveries from three typical textile auxiliary matrices including dispersant, antistatic agent and fabric softener, at three spiked levels were in the range of 97.2%-108.3% with the relative standard deviations (RSDs) of 1.5%-4.6%. The method is sensitive, accurate, simple and effective for the analysis of DHTDMAC in textile auxiliaries.

  7. Quantitative Analysis of Staphylococcal Enterotoxins A and B in Food Matrices Using Ultra High-Performance Liquid Chromatography Tandem Mass Spectrometry (UPLC-MS/MS)

    PubMed Central

    Zuberovic Muratovic, Aida; Hagström, Thomas; Rosén, Johan; Granelli, Kristina; Hellenäs, Karl-Erik

    2015-01-01

    A method that uses mass spectrometry (MS) for identification and quantification of protein toxins, staphylococcal enterotoxins A and B (SEA and SEB), in milk and shrimp is described. The analysis was performed using a tryptic peptide, from each of the toxins, as the target analyte together with the corresponding 13C-labeled synthetic internal standard peptide. The performance of the method was evaluated by analyzing spiked samples in the quantification range 2.5–30 ng/g (R2 = 0.92–0.99). The limit of quantification (LOQ) in milk and the limit of detection (LOD) in shrimp was 2.5 ng/g, for both SEA and SEB toxins. The in-house reproducibility (RSD) was 8%–30% and 5%–41% at different concentrations for milk and shrimp, respectively. The method was compared to the ELISA method, used at the EU-RL (France), for milk samples spiked with SEA at low levels, in the quantification range of 2.5 to 5 ng/g. The comparison showed good coherence for the two methods: 2.9 (MS)/1.8 (ELISA) and 3.6 (MS)/3.8 (ELISA) ng/g. The major advantage of the developed method is that it allows direct confirmation of the molecular identity and quantitative analysis of SEA and SEB at low nanogram levels using a label and antibody free approach. Therefore, this method is an important step in the development of alternatives to the immune-assay tests currently used for staphylococcal enterotoxin analysis. PMID:26378579

  8. Validation of a novel in vitro assay using ultra performance liquid chromatography-mass spectrometry (UPLC/MS) to detect and quantify hydroxylated metabolites of BDE-99 in rat liver microsomes.

    PubMed

    Erratico, Claudio A; Szeitz, András; Bandiera, Stelvio M

    2010-06-01

    The purpose of this study was to develop and validate an ultra performance liquid chromatography-mass spectrometry (UPLC/MS) method to investigate the hepatic oxidative metabolism of 2,2',4,4',5-pentabromodiphenyl ether (BDE-99), a widely used flame retardant and ubiquitous environmental contaminant. Hydroxylated metabolites were extracted using liquid-to-liquid extraction, resolved on a C18 column with gradient elution and detected by mass spectrometry in single ion recording mode using electrospray negative ionization. The assay was validated for linearity, accuracy, precision, limit of quantification, range and recovery. Calibration curves were linear (R2 > or = 0.98) over a concentration range of 0.010-1.0 microM for 4-OH-2,2',3,4',5-pentabromodiphenyl ether (4-OH-BDE-90), 5'-OH-2,2',4,4',5-pentabromodiphenyl ether (5'-OH-BDE-99) and 6'-OH-2,2',4,4',5-pentabromodiphenyl ether (6'-OH-BDE-99), and a concentration range of 0.0625-12.5 microM for 2,4,5-tribromophenol (2,4,5-TBP). Inter- and intra-day accuracy values ranged from -2.0% to 6.0% and from -7.7% to 7.3%, respectively, and inter- and intra-day precision values ranged from 2.0% to 8.5% and from 2.2% to 8.6% (n=6), respectively. The limits of quantification were 0.010 microM for 4-OH-BDE-90, 5'-OH-BDE-99 and 6'-OH-BDE-99, and 0.0625 microM for 2,4,5-TBP. Recovery values ranged between 85 and 100% for the four analytes. The validated analytical method was applied to identify and quantify hydroxy BDE-99 metabolites formed in vitro. Incubation of BDE-99 with rat liver microsomes yielded 4-OH-BDE-90 and 6'-OH-BDE-99 as major metabolites and 5'-OH-BDE-99 and 2,4,5-TBP as minor metabolites. To our knowledge, this is the first validated UPLC/MS method to quantify hydroxylated metabolites of PBDEs without the need of derivatization. PMID:20451473

  9. Rapid screening of mycotoxins in liquid milk and milk powder by automated size-exclusion SPE-UPLC-MS/MS and quantification of matrix effects over the whole chromatographic run.

    PubMed

    Wang, Xiupin; Li, Peiwu

    2015-04-15

    An automated, size-exclusion solid phase extraction (SPE)-UPLC-MS/MS protocol without pre-treatment of samples was developed to screen for four mycotoxins (OTA, ZEN, AFB1, and AFM1) in liquid milk and milk powder. Firstly, a mixed macropore-silica gel cartridge was established as a size-exclusion SPE column. The proposed methodology could be a candidate in green analytical chemistry because it saves on manpower and organic solvent. Permanent post-column infusion of mycotoxin standards was used to quantify matrix effects throughout the chromatographic run. Matrix-matched calibration could effectively compensate for matrix effects, which may be caused by liquid milk or milk powder matrix. Recovery of the four mycotoxins in fortified liquid milk was in the range 89-120% and RSD 2-9%. The LOD for the four mycotoxins in liquid milk and milk powder were 0.05-2 ng L(-1) and 0.25-10 ng kg(-1), respectively. The LOQ for the four mycotoxins in liquid milk and milk powder were 0.1-5 ng L(-1) and 0.5-25 ng kg(-1), respectively.

  10. Ultra-performance liquid chromatography mass spectrometry and sensitive bioassay methods for quantification of posaconazole plasma concentrations after oral dosing.

    PubMed

    Rochat, Bertrand; Pascual, Andres; Pesse, Benoît; Lamoth, Frédéric; Sanglard, Dominique; Decosterd, Laurent A; Bille, Jacques; Marchetti, Oscar

    2010-12-01

    Posaconazole (POS) is a new antifungal agent for prevention and therapy of mycoses in immunocompromised patients. Variable POS pharmacokinetics after oral dosing may influence efficacy: a trough threshold of 0.5 μg/ml has been recently proposed. Measurement of POS plasma concentrations by complex chromatographic techniques may thus contribute to optimize prevention and management of life-threatening infections. No microbiological analytical method is available. The objective of this study was to develop and validate a new simplified ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method and a sensitive bioassay for quantification of POS over the clinical plasma concentration range. The UPLC-MS/MS equipment consisted of a triple quadrupole mass spectrometer, an electrospray ionization (ESI) source, and a C(18) analytical column. The Candida albicans POS-hypersusceptible mutant (MIC of 0.002 μg/ml) Δcdr1 Δcdr2 Δflu Δmdr1 Δcan constructed by targeted deletion of multidrug efflux transporters and calcineurin genes was used for the bioassay. POS was extracted from plasma by protein precipitation with acetonitrile-methanol (75%/25%, vol/vol). Reproducible standard curves were obtained over the range 0.014 to 12 (UPLC-MS/MS) and 0.028 to 12 μg/ml (bioassay). Intra- and interrun accuracy levels were 106% ± 2% and 103% ± 4% for UPLC-MS/MS and 102% ± 8% and 104% ± 1% for bioassay, respectively. The intra- and interrun coefficients of variation were 7% ± 4% and 7% ± 3% for UPLC-MS/MS and 5% ± 3% and 4% ± 2% for bioassay, respectively. An excellent correlation between POS plasma concentrations measured by UPLC-MS/MS and bioassay was found (concordance, 0.96). In 26 hemato-oncological patients receiving oral POS, 27/69 (39%) trough plasma concentrations were lower than 0.5 μg/ml. The UPLC-MS/MS method and sensitive bioassay offer alternative tools for accurate and precise quantification of the plasma concentrations in patients

  11. SPE-UPLC-MS/MS for the determination of phthalate monoesters in rats urine and its application to study the effects of food emulsifier on the bioavailability of priority controlling PAEs.

    PubMed

    Xu, R; Gao, H T; Zhu, F; Cao, W X; Yan, Y H M; Zhou, X; Xu, Q; Ji, W L

    2016-02-15

    This research was mainly focused on the effects of food emulsifier on the bioavailability of six priority controlling phthalate acid esters (PAEs) for the further accurate assessment of their toxic effects, using the corresponding phthalate acid monoesters (PAMEs) in rats urine as biomarkers. Glycerin monostearate was chosen as typical food emulsifier. A method was established to determine PAMEs in urine from rats either in experimental group (integrated gavaged with glycerin monostearate and PAEs) or in control group (gavaged with PAEs only), by using solid-phase extraction (SPE) coupled with ultra performance liquid chromatography tandem mass spectrometry (SPE-UPLC-MS/MS). Extraction recoveries were more than 75% for all the PAMEs; the calibration curve was linear in the range of 1.0-1000.0ng/mL with R(2)>0.995; the limits of detection (LOD) were 0.30ng/mL-0.50ng/mL. In addition, by analysing quality control (QC) urine samples in 3 days, it showed that the method was precise and accurate, for the intra-day and inter-day RSD within 16%, and the accuracy more than 82%. Internal exposure amount of all PAEs in experimental group was significantly higher than that in control group with p values of less than 0.05 except for butyl benzyl phthalates (BBP) (P=0.07). The bioavailability of all PAEs ranged from 5.03% to 109.35% with the presence of food emulsifiers glycerin monostearate, observably higher than that without glycerin monostearate (1.12% to 54.39%). It indicated that food emulsifiers increased the bioavailability of PAEs and may lead to potential food safety risk, which should bring awareness and be further studied.

  12. SPE-UPLC-MS/MS for the determination of phthalate monoesters in rats urine and its application to study the effects of food emulsifier on the bioavailability of priority controlling PAEs.

    PubMed

    Xu, R; Gao, H T; Zhu, F; Cao, W X; Yan, Y H M; Zhou, X; Xu, Q; Ji, W L

    2016-02-15

    This research was mainly focused on the effects of food emulsifier on the bioavailability of six priority controlling phthalate acid esters (PAEs) for the further accurate assessment of their toxic effects, using the corresponding phthalate acid monoesters (PAMEs) in rats urine as biomarkers. Glycerin monostearate was chosen as typical food emulsifier. A method was established to determine PAMEs in urine from rats either in experimental group (integrated gavaged with glycerin monostearate and PAEs) or in control group (gavaged with PAEs only), by using solid-phase extraction (SPE) coupled with ultra performance liquid chromatography tandem mass spectrometry (SPE-UPLC-MS/MS). Extraction recoveries were more than 75% for all the PAMEs; the calibration curve was linear in the range of 1.0-1000.0ng/mL with R(2)>0.995; the limits of detection (LOD) were 0.30ng/mL-0.50ng/mL. In addition, by analysing quality control (QC) urine samples in 3 days, it showed that the method was precise and accurate, for the intra-day and inter-day RSD within 16%, and the accuracy more than 82%. Internal exposure amount of all PAEs in experimental group was significantly higher than that in control group with p values of less than 0.05 except for butyl benzyl phthalates (BBP) (P=0.07). The bioavailability of all PAEs ranged from 5.03% to 109.35% with the presence of food emulsifiers glycerin monostearate, observably higher than that without glycerin monostearate (1.12% to 54.39%). It indicated that food emulsifiers increased the bioavailability of PAEs and may lead to potential food safety risk, which should bring awareness and be further studied. PMID:26815919

  13. Simultaneous determination of five components in rat plasma by UPLC-MS/MS and its application to a comparative pharmacokinetic study in Baihe Zhimu Tang and Zhimu extract.

    PubMed

    Li, Guolong; Tang, Zhishu; Yang, Jie; Duan, Jinao; Qian, Dawei; Guo, Jianming; Zhu, Zhenhua; Liu, Hongbo

    2015-01-01

    Baihe Zhimu Tang (BZT) is a famous traditional Chinese medicine recipe to treat dry coughing due to yin deficiency and for moisturizing the lungs. Zhimu is an essential ingredient in BZT used to treat inflammation, fever and diabetes. The most important active components in Zhimu are flavonoids such as neomangiferin, mangiferin, and steroid saponins (e.g., timosaponin BII, anemarsaponin BIII, timosaponin AIII). The aim of this study was to compare the pharmacokinetics of mangiferin, neomangiferin, timosaponin BII, anemarsaponin BIII and timosaponin AIII in rat plasma after oral administration of BZT and Zhimu extract (ZME). A sensitive, reliable and robust LC-MS/MS method to simultaneously determine steroid saponins and flavonoids in rat plasma was successfully validated. Significant differences (p < 0.05) were found in the pharmacokinetic parameters of timosaponin BII, anemarsaponin BIII and timosaponin AIII between BZT and ZME. It was surmised that formula compatibility could significantly influence the pharmacokinetics of BZT and our study is the first to study the administration of BZT based on pharmacokinetic studies.

  14. Quantification of sofosbuvir and ledipasvir in human plasma by UPLC-MS/MS method: Application to fasting and fed bioequivalence studies.

    PubMed

    Rezk, Mamdouh R; Bendas, Ehab R; Basalious, Emad B; Karim, Iman A

    2016-08-15

    A rapid and sensitive LC-MS/MS method was developed, optimized and validated for quantification of sofosbuvir (SF) and ledipasvir (LD) in human plasma using eplerenone as an internal standard (IS). Analytes and IS were extracted from plasma by simple liquid-liquid extraction technique using methyl tertiary butyl ether. The prepared samples were chromatographed on Acquity UPLC BEH C18 column. Separation was done using a mobile phase formed of 0.1% formic acid and acetonitrile (50:50, v/v) in an isocratic mode at a flow rate of 0.4ml/min. The Xevo TQD LC-MS/MS was operated under the multiple-reaction monitoring mode using electrospray ionization. A full validation of the method was performed according to the FDA guidelines. Linearity was found to be in the range of 0.25-3500ng/ml for SF and 5-2000ng/ml for LD. The intra-day and inter-day precision and accuracy results were within the acceptable limits. A short run time of 2min allows analysis of more than 400 plasma samples per day. The developed method was successfully applied to both fasting and fed bioequivalence studies in healthy human volunteers. PMID:27322631

  15. HILIC-UPLC-MS/MS combined with hierarchical clustering analysis to rapidly analyze and evaluate nucleobases and nucleosides in Ginkgo biloba leaves.

    PubMed

    Yao, Xin; Zhou, Guisheng; Tang, Yuping; Guo, Sheng; Qian, Dawei; Duan, Jin-Ao

    2015-02-01

    Ginkgo biloba leaf extract has been widely used in dietary supplements and more recently in some foods and beverages. In addition to the well-known flavonol glycosides and terpene lactones, G. biloba leaves are also rich in nucleobases and nucleosides. To determine the content of nucleobases and nucleosides in G. biloba leaves at trace levels, a reliable method has been established by using hydrophilic interaction ultra performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (HILIC-UPLC-TQ-MS/MS) working in multiple reaction monitoring mode. Eleven nucleobases and nucleosides were simultaneously determined in seven min. The proposed method was fully validated in terms of linearity, sensitivity, and repeatability, as well as recovery. Furthermore, hierarchical clustering analysis (HCA) was performed to evaluate and classify the samples according to the contents of the eleven chemical constituents. The established approach could be helpful for evaluation of the potential values as dietary supplements and the quality control of G. biloba leaves, which might also be utilized for the investigation of other medicinal herbs containing nucleobases and nucleosides.

  16. Simultaneous determination of five components in rat plasma by UPLC-MS/MS and its application to a comparative pharmacokinetic study in Baihe Zhimu Tang and Zhimu extract.

    PubMed

    Li, Guolong; Tang, Zhishu; Yang, Jie; Duan, Jinao; Qian, Dawei; Guo, Jianming; Zhu, Zhenhua; Liu, Hongbo

    2015-01-01

    Baihe Zhimu Tang (BZT) is a famous traditional Chinese medicine recipe to treat dry coughing due to yin deficiency and for moisturizing the lungs. Zhimu is an essential ingredient in BZT used to treat inflammation, fever and diabetes. The most important active components in Zhimu are flavonoids such as neomangiferin, mangiferin, and steroid saponins (e.g., timosaponin BII, anemarsaponin BIII, timosaponin AIII). The aim of this study was to compare the pharmacokinetics of mangiferin, neomangiferin, timosaponin BII, anemarsaponin BIII and timosaponin AIII in rat plasma after oral administration of BZT and Zhimu extract (ZME). A sensitive, reliable and robust LC-MS/MS method to simultaneously determine steroid saponins and flavonoids in rat plasma was successfully validated. Significant differences (p < 0.05) were found in the pharmacokinetic parameters of timosaponin BII, anemarsaponin BIII and timosaponin AIII between BZT and ZME. It was surmised that formula compatibility could significantly influence the pharmacokinetics of BZT and our study is the first to study the administration of BZT based on pharmacokinetic studies. PMID:25884551

  17. Ultrasound-assisted hydrolysis of conjugated parabens in human urine and their determination by UPLC-MS/MS and UPLC-HRMS.

    PubMed

    Schlittenbauer, Linda; Seiwert, Bettina; Reemtsma, Thorsten

    2016-02-01

    Parabens are preservatives widely used in personal care products, pharmaceutical formulations as well as in food, and they are considered endocrine disruptors. For application in biomonitoring studies we developed a method for the determination of eight parabens from human urine. Sample preparation was enhanced and simplified by the combination of ultrasound-assisted enzymatic hydrolysis of conjugates (glucuronide and sulfate) followed by an extraction-free cleanup step. Quantification, using deuterated parabens as internal standards, was performed by ultrahigh-performance liquid chromatography coupled to either triple-quadrupole (UPLC-QqQ) or time-of-flight (UPLC-QqTOF) mass spectrometry. Full chromatographic separation of three butyl paraben isomers was achieved. Limits of quantification for both mass analyzers ranged from 0.1 to 0.5 μg/L for methyl, ethyl, n-/isopropyl, n-/isobutyl, and benzyl paraben in 200 μL of urine sample. The method was tested for applicability and showed high precision (intra- and interday 0.9-14.5%) as well as high accuracy (relative recovery 95-132%). A total of 39 urine samples were analyzed by both mass analyzers. The results agreed well, with a trend to higher deviation at low concentrations (less than 10 μg/L). Methyl, ethyl, and n-propyl paraben were detected most frequently (in more than 87% of the samples) with median concentrations ranging from 0.8 to 16.6 μg/L. Female urine showed higher median concentrations for all parabens, which may indicate higher exposure due to lifestyle. This method permits accurate and high-throughput analysis of parabens for epidemiological studies. Further, the UPLC-QqTOF approach provides additional information on human exposure to other compounds by post-acquisition analysis. PMID:26753983

  18. Natural occurrence of fumonisins and ochratoxin A in some herbs and spices commercialized in Poland analyzed by UPLC-MS/MS method.

    PubMed

    Waśkiewicz, Agnieszka; Beszterda, Monika; Bocianowski, Jan; Goliński, Piotr

    2013-12-01

    Unsanitary conditions during harvesting, drying, packing and storage stages in production and processing of spices and herbs could introduce mycotoxin contamination. The occurrence of ochratoxin A and fumonisins in popular spices and herbs was studied, using liquid chromatography-electrospray-mass spectrometry. Apart from mycotoxins, ergosterol as a factor indicating fungal development was also analysed. A total of 79 different samples commercialized in Poland were randomly purchased from popular markets were tested for mycotoxins. The frequency of samples with fumonisins was lower (31%) than ochratoxin A (49%). Free from mycotoxins were samples of bay leaf and white mustard. ERG content - in spice samples with high concentration level of mycotoxins - was also significantly higher than in samples with little to no mycotoxins. PMID:24010625

  19. Natural occurrence of fumonisins and ochratoxin A in some herbs and spices commercialized in Poland analyzed by UPLC-MS/MS method.

    PubMed

    Waśkiewicz, Agnieszka; Beszterda, Monika; Bocianowski, Jan; Goliński, Piotr

    2013-12-01

    Unsanitary conditions during harvesting, drying, packing and storage stages in production and processing of spices and herbs could introduce mycotoxin contamination. The occurrence of ochratoxin A and fumonisins in popular spices and herbs was studied, using liquid chromatography-electrospray-mass spectrometry. Apart from mycotoxins, ergosterol as a factor indicating fungal development was also analysed. A total of 79 different samples commercialized in Poland were randomly purchased from popular markets were tested for mycotoxins. The frequency of samples with fumonisins was lower (31%) than ochratoxin A (49%). Free from mycotoxins were samples of bay leaf and white mustard. ERG content - in spice samples with high concentration level of mycotoxins - was also significantly higher than in samples with little to no mycotoxins.

  20. Dose-Independent ADME Properties and Tentative Identification of Metabolites of α-Mangostin from Garcinia mangostana in Mice by Automated Microsampling and UPLC-MS/MS Methods.

    PubMed

    Han, Seung Yon; You, Byoung Hoon; Kim, Yu Chul; Chin, Young-Won; Choi, Young Hee

    2015-01-01

    The information about a marker compound's pharmacokinetics in herbal products including the characteristics of absorption, distribution, metabolism, excretion (ADME) is closely related to the efficacy/toxicity. Also dose range and administration route are critical factors to determine the ADME profiles. Since the supply of a sufficient amount of a marker compound in in vivo study is still difficult, pharmacokinetic investigations which overcome the limit of blood collection in mice are desirable. Thus, we have attempted to investigate concurrently the ADME and proposed metabolite identification of α-mangostin, a major constituent of mangosteen, Garcinia mangostana L, in mice with a wide dose range using an in vitro as well as in vivo automated micro-sampling system together. α-mangostin showed dose-proportional pharmacokinetics at intravenous doses of 5-20 mg/kg and oral doses of 10-100 mg/kg. The gastrointestinal absorption of α-mangostin was poor and the distribution of α-mangostin was relatively high in the liver, intestine, kidney, fat, and lung. α-mangostin was extensively metabolized in the liver and intestine. With regards to the formation of metabolites, the glucuronidated, bis-glucuronidated, dehydrogenated, hydrogenated, oxidized, and methylated α-mangostins were tentatively identified. We suggest that these dose-independent pharmacokinetic characteristics of α-mangostin in mice provide an important basis for preclinical applications of α-mangostin as well as mangosteen. In addition, these experimental methods can be applied to evaluate the pharmacokinetics of natural products in mice.

  1. Dose-Independent ADME Properties and Tentative Identification of Metabolites of α-Mangostin from Garcinia mangostana in Mice by Automated Microsampling and UPLC-MS/MS Methods.

    PubMed

    Han, Seung Yon; You, Byoung Hoon; Kim, Yu Chul; Chin, Young-Won; Choi, Young Hee

    2015-01-01

    The information about a marker compound's pharmacokinetics in herbal products including the characteristics of absorption, distribution, metabolism, excretion (ADME) is closely related to the efficacy/toxicity. Also dose range and administration route are critical factors to determine the ADME profiles. Since the supply of a sufficient amount of a marker compound in in vivo study is still difficult, pharmacokinetic investigations which overcome the limit of blood collection in mice are desirable. Thus, we have attempted to investigate concurrently the ADME and proposed metabolite identification of α-mangostin, a major constituent of mangosteen, Garcinia mangostana L, in mice with a wide dose range using an in vitro as well as in vivo automated micro-sampling system together. α-mangostin showed dose-proportional pharmacokinetics at intravenous doses of 5-20 mg/kg and oral doses of 10-100 mg/kg. The gastrointestinal absorption of α-mangostin was poor and the distribution of α-mangostin was relatively high in the liver, intestine, kidney, fat, and lung. α-mangostin was extensively metabolized in the liver and intestine. With regards to the formation of metabolites, the glucuronidated, bis-glucuronidated, dehydrogenated, hydrogenated, oxidized, and methylated α-mangostins were tentatively identified. We suggest that these dose-independent pharmacokinetic characteristics of α-mangostin in mice provide an important basis for preclinical applications of α-mangostin as well as mangosteen. In addition, these experimental methods can be applied to evaluate the pharmacokinetics of natural products in mice. PMID:26176540

  2. Dose-Independent ADME Properties and Tentative Identification of Metabolites of α-Mangostin from Garcinia mangostana in Mice by Automated Microsampling and UPLC-MS/MS Methods

    PubMed Central

    Kim, Yu Chul; Chin, Young-Won; Choi, Young Hee

    2015-01-01

    The information about a marker compound's pharmacokinetics in herbal products including the characteristics of absorption, distribution, metabolism, excretion (ADME) is closely related to the efficacy/toxicity. Also dose range and administration route are critical factors to determine the ADME profiles. Since the supply of a sufficient amount of a marker compound in in vivo study is still difficult, pharmacokinetic investigations which overcome the limit of blood collection in mice are desirable. Thus, we have attempted to investigate concurrently the ADME and proposed metabolite identification of α-mangostin, a major constituent of mangosteen, Garcinia mangostana L, in mice with a wide dose range using an in vitro as well as in vivo automated micro-sampling system together. α-mangostin showed dose-proportional pharmacokinetics at intravenous doses of 5–20 mg/kg and oral doses of 10–100 mg/kg. The gastrointestinal absorption of α-mangostin was poor and the distribution of α-mangostin was relatively high in the liver, intestine, kidney, fat, and lung. α-mangostin was extensively metabolized in the liver and intestine. With regards to the formation of metabolites, the glucuronidated, bis-glucuronidated, dehydrogenated, hydrogenated, oxidized, and methylated α-mangostins were tentatively identified. We suggest that these dose-independent pharmacokinetic characteristics of α-mangostin in mice provide an important basis for preclinical applications of α-mangostin as well as mangosteen. In addition, these experimental methods can be applied to evaluate the pharmacokinetics of natural products in mice. PMID:26176540

  3. High-Sensitivity Microwave Optics.

    ERIC Educational Resources Information Center

    Nunn, W. M., Jr.

    1981-01-01

    Describes a 3.33-cm wavelength (9 GHz) microwave system that achieves a high overall signal sensitivity and a well-collimated beam with moderate-size equipment. The system has been used to develop microwave versions of the Michelson interferometer, Bragg reflector, Brewster's law and total internal reflection, and Young's interference experiment.…

  4. An ultra-high-performance liquid chromatography-tandem mass spectrometric method for the determination of hederacoside C, a drug candidate for respiratory disorder, in rat plasma.

    PubMed

    Rehman, Shaheed Ur; Choi, Min Sun; Kim, In Sook; Kim, Seung Hyun; Yoo, Hye Hyun

    2016-09-10

    Hederacoside C is a principal bioactive pharmaceutical ingredient of Hedera helix leaf extracts. H. helix extracts have long been used in folk medicine for the treatment of respiratory disorders. Currently, hederacoside C is investigated as a promising candidate for the treatment of respiratory diseases. In this study, an accurate, sensitive, rapid, and reliable bioanalytical method was developed for the determination of hederacoside C in rat plasma using ultra high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). For sample preparation, plasma proteins were precipitated with 0.1% acetic acid in acetonitrile. Waters UPLC BEH C18 (2.1mm I.D.×100mm, 1.7μm) column was used for chromatographic separation. A gradient elution of mobile phases consisting of 0.02% acetic acid in distilled water (solvent A) and 0.02% acetic acid in acetonitrile (solvent B) was used at a flow rate of 0.3mL/min. The multiple reaction monitoring (MRM) mode was used for mass spectrometric detection; the MRM transitions were m/z 1219.7→m/z 469.2 for hederacoside C and m/z 1108.3→m/z 221.2 for ginsenoside Rb1 (internal standard) in the negative ionization mode. A calibration curve was constructed in the range of 10-1000ng/mL. The intra- and inter-day precision and accuracy were within 5%. The developed UPLC-MS/MS method was successfully applied in a pharmacokinetic study of hederacoside C in rats. Hederacoside C was quickly but inadequately absorbed from the gastrointestinal tract of rats resulting in extremely low bioavailability and relatively slow clearance.

  5. An ultra-high-performance liquid chromatography-tandem mass spectrometric method for the determination of hederacoside C, a drug candidate for respiratory disorder, in rat plasma.

    PubMed

    Rehman, Shaheed Ur; Choi, Min Sun; Kim, In Sook; Kim, Seung Hyun; Yoo, Hye Hyun

    2016-09-10

    Hederacoside C is a principal bioactive pharmaceutical ingredient of Hedera helix leaf extracts. H. helix extracts have long been used in folk medicine for the treatment of respiratory disorders. Currently, hederacoside C is investigated as a promising candidate for the treatment of respiratory diseases. In this study, an accurate, sensitive, rapid, and reliable bioanalytical method was developed for the determination of hederacoside C in rat plasma using ultra high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). For sample preparation, plasma proteins were precipitated with 0.1% acetic acid in acetonitrile. Waters UPLC BEH C18 (2.1mm I.D.×100mm, 1.7μm) column was used for chromatographic separation. A gradient elution of mobile phases consisting of 0.02% acetic acid in distilled water (solvent A) and 0.02% acetic acid in acetonitrile (solvent B) was used at a flow rate of 0.3mL/min. The multiple reaction monitoring (MRM) mode was used for mass spectrometric detection; the MRM transitions were m/z 1219.7→m/z 469.2 for hederacoside C and m/z 1108.3→m/z 221.2 for ginsenoside Rb1 (internal standard) in the negative ionization mode. A calibration curve was constructed in the range of 10-1000ng/mL. The intra- and inter-day precision and accuracy were within 5%. The developed UPLC-MS/MS method was successfully applied in a pharmacokinetic study of hederacoside C in rats. Hederacoside C was quickly but inadequately absorbed from the gastrointestinal tract of rats resulting in extremely low bioavailability and relatively slow clearance. PMID:27411171

  6. Fast, high sensitivity dewpoint hygrometer

    NASA Technical Reports Server (NTRS)

    Hoenk, Michael E. (Inventor)

    1998-01-01

    A dewpoint/frostpoint hygrometer that uses a surface moisture-sensitive sensor as part of an RF oscillator circuit with feedback control of the sensor temperature to maintain equilibrium at the sensor surface between ambient water vapor and condensed water/ice. The invention is preferably implemented using a surface acoustic wave (SAW) device in an RF oscillator circuit configured to generate a condensation-dependent output signal, a temperature sensor to measure the temperature of the SAW device and to distinguish between condensation-dependent and temperature-dependent signals, a temperature regulating device to control the temperature of the SAW device, and a feedback control system configured to keep the condensation-dependent signal nearly constant over time in the presence of time-varying humidity, corrected for temperature. The effect of this response is to heat or cool the surface moisture-sensitive device, which shifts the equilibrium with respect to evaporation and condensation at the surface of the device. The equilibrium temperature under feedback control is a measure of dewpoint or frostpoint.

  7. Cryogenic High-Sensitivity Magnetometer

    NASA Technical Reports Server (NTRS)

    Day, Peter; Chui, Talso; Goodstein, David

    2005-01-01

    A proposed magnetometer for use in a cryogenic environment would be sensitive enough to measure a magnetic-flux density as small as a picogauss (10(exp -16) Tesla). In contrast, a typical conventional flux-gate magnetometer cannot measure a magnetic-flux density smaller that about 1 microgauss (10(exp -10) Tesla). One version of this device, for operation near the low end of the cryogenic temperature range, would include a piece of a paramagnetic material on a platform, the temperature of which would be controlled with a periodic variation. The variation in temperature would be measured by use of a conventional germanium resistance thermometer. A superconducting coil would be wound around the paramagnetic material and coupled to a superconducting quantum interference device (SQUID) magnetometer.

  8. Nano-textured high sensitivity ion sensitive field effect transistors

    NASA Astrophysics Data System (ADS)

    Hajmirzaheydarali, M.; Sadeghipari, M.; Akbari, M.; Shahsafi, A.; Mohajerzadeh, S.

    2016-02-01

    Nano-textured gate engineered ion sensitive field effect transistors (ISFETs), suitable for high sensitivity pH sensors, have been realized. Utilizing a mask-less deep reactive ion etching results in ultra-fine poly-Si features on the gate of ISFET devices where spacing of the order of 10 nm and less is achieved. Incorporation of these nano-sized features on the gate is responsible for high sensitivities up to 400 mV/pH in contrast to conventional planar structures. The fabrication process for this transistor is inexpensive, and it is fully compatible with standard complementary metal oxide semiconductor fabrication procedure. A theoretical modeling has also been presented to predict the extension of the diffuse layer into the electrolyte solution for highly featured structures and to correlate this extension with the high sensitivity of the device. The observed ultra-fine features by means of scanning electron microscopy and transmission electron microscopy tools corroborate the theoretical prediction.

  9. High sensitivity cymbal-based accelerometer

    SciTech Connect

    Sun Chengliang; Lam, K.H.; Choy, S.H.; Chan, H.L. W.; Zhao, X.-Z.; Choy, C.L.

    2006-03-15

    A high sensitivity piezoelectric accelerometer has been developed by replacing the conventional piezoelectric rings with a cymbal transducer. The sensitivity of the cymbal-based accelerometers containing cymbal transducers with different endcap thicknesses and different seismic masses has been measured as a function of driving frequency. Due to the high d{sub 33}{sup '} coefficient of the cymbal transducers, the cymbal-based accelerometers have a high sensitivity of {approx}97 pC/ms{sup -2} with the amplitude rise of 2.85% (<1 dB) at one-third of the mounted resonance frequency (3.38 kHz). The effect of the seismic mass, the resonance frequency, and d{sub 33}{sup '} coefficient of the cymbal transducers on the sensitivity and the frequency range of the cymbal-based accelerometers are reported.

  10. High sensitivity knitted fabric strain sensors

    NASA Astrophysics Data System (ADS)

    Xie, Juan; Long, Hairu; Miao, Menghe

    2016-10-01

    Wearable sensors are increasingly used in smart garments for detecting and transferring vital signals and body posture, movement and respiration. Existing fabric strain sensors made from metallized yarns have low sensitivity, poor comfort and low durability to washing. Here we report a knitted fabric strain sensor made from a cotton/stainless steel (SS) fibre blended yarn which shows much higher sensitivity than sensors knitted from metallized yarns. The fabric feels softer than pure cotton textiles owing to the ultrafine stainless steel fibres and does not lose its electrical property after washing. The reason for the high sensitivity of the cotton/SS knitted fabric sensor was explored by comparing its sensing mechanism with the knitted fabric sensor made from metallized yarns. The results show that the cotton/SS yarn-to-yarn contact resistance is highly sensitive to strain applied to hooked yarn loops.

  11. High Sensitivity deflection detection of nanowires

    SciTech Connect

    Sanii, Babak; Ashby, Paul

    2009-10-28

    A critical limitation of nanoelectromechanical systems (NEMS) is the lack of a high-sensitivity position detection mechanism. We introduce a noninterferometric optical approach to determine the position of nanowires with a high sensitivity and bandwidth. Its physical origins and limitations are determined by Mie scattering analysis. This enables a dramatic miniaturization of detectable cantilevers, with attendant reductions to the fundamental minimum force noise in highly damping environments. We measure the force noise of an 81{+-}9??nm radius Ag{sub 2}Ga nanowire cantilever in water at 6{+-}3??fN/{radical}Hz.

  12. High sensitivity optically pumped quantum magnetometer.

    PubMed

    Tiporlini, Valentina; Alameh, Kamal

    2013-01-01

    Quantum magnetometers based on optical pumping can achieve sensitivity as high as what SQUID-based devices can attain. In this paper, we discuss the principle of operation and the optimal design of an optically pumped quantum magnetometer. The ultimate intrinsic sensitivity is calculated showing that optimal performance of the magnetometer is attained with an optical pump power of 20 μW and an operation temperature of 48°C. Results show that the ultimate intrinsic sensitivity of the quantum magnetometer that can be achieved is 327 fT/Hz(½) over a bandwidth of 26 Hz and that this sensitivity drops to 130 pT/Hz(½) in the presence of environmental noise. The quantum magnetometer is shown to be capable of detecting a sinusoidal magnetic field of amplitude as low as 15 pT oscillating at 25 Hz. PMID:23766716

  13. High Sensitivity Optically Pumped Quantum Magnetometer

    PubMed Central

    Tiporlini, Valentina; Alameh, Kamal

    2013-01-01

    Quantum magnetometers based on optical pumping can achieve sensitivity as high as what SQUID-based devices can attain. In this paper, we discuss the principle of operation and the optimal design of an optically pumped quantum magnetometer. The ultimate intrinsic sensitivity is calculated showing that optimal performance of the magnetometer is attained with an optical pump power of 20 μW and an operation temperature of 48°C. Results show that the ultimate intrinsic sensitivity of the quantum magnetometer that can be achieved is 327 fT/Hz1/2 over a bandwidth of 26 Hz and that this sensitivity drops to 130 pT/Hz1/2 in the presence of environmental noise. The quantum magnetometer is shown to be capable of detecting a sinusoidal magnetic field of amplitude as low as 15 pT oscillating at 25 Hz. PMID:23766716

  14. High sensitivity optically pumped quantum magnetometer.

    PubMed

    Tiporlini, Valentina; Alameh, Kamal

    2013-01-01

    Quantum magnetometers based on optical pumping can achieve sensitivity as high as what SQUID-based devices can attain. In this paper, we discuss the principle of operation and the optimal design of an optically pumped quantum magnetometer. The ultimate intrinsic sensitivity is calculated showing that optimal performance of the magnetometer is attained with an optical pump power of 20 μW and an operation temperature of 48°C. Results show that the ultimate intrinsic sensitivity of the quantum magnetometer that can be achieved is 327 fT/Hz(½) over a bandwidth of 26 Hz and that this sensitivity drops to 130 pT/Hz(½) in the presence of environmental noise. The quantum magnetometer is shown to be capable of detecting a sinusoidal magnetic field of amplitude as low as 15 pT oscillating at 25 Hz.

  15. Successful kidney transplantation in highly sensitized patients.

    PubMed

    Zhang, Weijie; Chen, Dong; Chen, Zhishui; Zeng, Fanjun; Ming, Changsheng; Lin, Zhengbin; Zhou, Ping; Chen, Gang; Chen, Xiaoping

    2011-03-01

    Highly sensitized patients experience an increased number of rejection episodes and have poorer graft survival rates; hence, sensitization is a significant barrier to both access to and the success of organ transplantation. This study reports our experience in kidney transplantation in highly sensitized patients. Fourteen patients with sensitization or high levels of panelreactive antibodies (PRA) were studied. All patients were desensitized with pre-transplant intravenous immunoglobulin (IVIG)/plasmapheresis (PP) with or without rituximab and thymoglobulin induction therapy, combined with a Prograf/MMF/Pred immunosuppressive regimen. Of 14 patients, 10 showed good graft functions without acute rejection (AR) episodes. Acute cellular rejection in two patients was reversed by methylprednisolone. Two patients underwent antibody-mediated rejection; one was treated with PP/IVIG successfully, whereas the other lost graft functions due to the de novo production of donor-specific antibodies (DSA). Graft functions were stable, and there were no AR episodes in other patients. Conclusively, desensitization using PP/IVIG with or without rituximab increases the likelihood of successful live-donor kidney transplantation in sensitized recipients. PMID:21681679

  16. Environmental Sensitivity among Wisconsin High School Students.

    ERIC Educational Resources Information Center

    Sivek, Daniel J.

    2002-01-01

    A two-phase study was conducted to assess influences on environmental sensitivity (ES) in Wisconsin high school students. Three categories of influences emerged from phase I: environmental, role model, and personality. The influence most frequently cited by students as most important was time spent outdoors. Develops a profile of environmentally…

  17. Single photon detector with high polarization sensitivity

    PubMed Central

    Guo, Qi; Li, Hao; You, LiXing; Zhang, WeiJun; Zhang, Lu; Wang, Zhen; Xie, XiaoMing; Qi, Ming

    2015-01-01

    Polarization is one of the key parameters of light. Most optical detectors are intensity detectors that are insensitive to the polarization of light. A superconducting nanowire single photon detector (SNSPD) is naturally sensitive to polarization due to its nanowire structure. Previous studies focused on producing a polarization-insensitive SNSPD. In this study, by adjusting the width and pitch of the nanowire, we systematically investigate the preparation of an SNSPD with high polarization sensitivity. Subsequently, an SNSPD with a system detection efficiency of 12% and a polarization extinction ratio of 22 was successfully prepared. PMID:25875225

  18. Fiber specklegram sensors sensitivities at high temperatures

    NASA Astrophysics Data System (ADS)

    Rodriguez-Cobo, L.; Lomer, M.; Lopez-Higuera, J. M.

    2015-09-01

    In this work, the sensitivity of Fiber Specklegram Sensors to high temperatures (up to 800ºC) have been studied. Two multimode silica fibers have been introduced into a tubular furnace while a HeNe laser source was launched into a fiber edge, projecting speckle patterns to a commercial webcam. A computer generated different heating and cooling sweeps while the specklegram evolution was recorded. The achieved results exhibit a remarkably linearity in FSS's sensitivity for temperatures under 800ºC, following the thermal expansion of fused silica.

  19. Validated UPLC-MS/MS method for simultaneous determination of simvastatin, simvastatin hydroxy acid and berberine in rat plasma: Application to the drug-drug pharmacokinetic interaction study of simvastatin combined with berberine after oral administration in rats.

    PubMed

    Liu, Mei; Su, Xianying; Li, Guofei; Zhao, Guilian; Zhao, Limei

    2015-12-01

    A rapid and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) assay method was developed and validated for simultaneous quantification of simvastatin (SV), its metabolite simvastatin hydroxy acid (SVA) and berberine (BBR) in rat plasma. Separation was performed on Poroshell 120 EC-C18 column (4.6×50mm, 2.7μm) using gradient elution by mobile phase containing acetonitrile and 10mM ammonium acetate (pH 4.5). Polarity switch (positive-negative-positive ionization mode) was performed in a total run time of 4.0min. The lower limits of quantification (LLOQ) for SV, SVA and BBR were 0.10, 0.20 and 0.10ng/mL, respectively. The response function was established for concentration range of 0.10-100ng/mL for SV and BBR and 0.20-3000ng/mL for SVA, with a coefficient of correlation of >0.99 for all the compounds. The proposed method was applied to the drug-drug pharmacokinetic interaction study of SV combined with BBR after oral administration in rats.

  20. High blood pressure and visual sensitivity

    NASA Astrophysics Data System (ADS)

    Eisner, Alvin; Samples, John R.

    2003-09-01

    The study had two main purposes: (1) to determine whether the foveal visual sensitivities of people treated for high blood pressure (vascular hypertension) differ from the sensitivities of people who have not been diagnosed with high blood pressure and (2) to understand how visual adaptation is related to standard measures of systemic cardiovascular function. Two groups of middle-aged subjects-hypertensive and normotensive-were examined with a series of test/background stimulus combinations. All subjects met rigorous inclusion criteria for excellent ocular health. Although the visual sensitivities of the two subject groups overlapped extensively, the age-related rate of sensitivity loss was, for some measures, greater for the hypertensive subjects, possibly because of adaptation differences between the two groups. Overall, the degree of steady-state sensitivity loss resulting from an increase of background illuminance (for 580-nm backgrounds) was slightly less for the hypertensive subjects. Among normotensive subjects, the ability of a bright (3.8-log-td), long-wavelength (640-nm) adapting background to selectively suppress the flicker response of long-wavelength-sensitive (LWS) cones was related inversely to the ratio of mean arterial blood pressure to heart rate. The degree of selective suppression was also related to heart rate alone, and there was evidence that short-term changes of cardiovascular response were important. The results suggest that (1) vascular hypertension, or possibly its treatment, subtly affects visual function even in the absence of eye disease and (2) changes in blood flow affect retinal light-adaptation processes involved in the selective suppression of the flicker response from LWS cones caused by bright, long-wavelength backgrounds.

  1. Highly Energetic, Low Sensitivity Aromatic Peroxy Acids.

    PubMed

    Gamage, Nipuni-Dhanesha H; Stiasny, Benedikt; Stierstorfer, Jörg; Martin, Philip D; Klapötke, Thomas M; Winter, Charles H

    2016-02-18

    The synthesis, structure, and energetic materials properties of a series of aromatic peroxy acid compounds are described. Benzene-1,3,5-tris(carboperoxoic) acid is a highly sensitive primary energetic material, with impact and friction sensitivities similar to those of triacetone triperoxide. By contrast, benzene-1,4-bis(carboperoxoic) acid, 4-nitrobenzoperoxoic acid, and 3,5-dinitrobenzoperoxoic acid are much less sensitive, with impact and friction sensitivities close to those of the secondary energetic material 2,4,6-trinitrotoluene. Additionally, the calculated detonation velocities of 3,5-dinitrobenzoperoxoic acid and 2,4,6-trinitrobenzoperoxoic acid exceed that of 2,4,6-trinitrotoluene. The solid-state structure of 3,5-dinitrobenzoperoxoic acid contains intermolecular O-H⋅⋅⋅O hydrogen bonds and numerous N⋅⋅⋅O, C⋅⋅⋅O, and O⋅⋅⋅O close contacts. These attractive lattice interactions may account for the less sensitive nature of 3,5-dinitrobenzoperoxoic acid. PMID:26743434

  2. Highly Energetic, Low Sensitivity Aromatic Peroxy Acids.

    PubMed

    Gamage, Nipuni-Dhanesha H; Stiasny, Benedikt; Stierstorfer, Jörg; Martin, Philip D; Klapötke, Thomas M; Winter, Charles H

    2016-02-18

    The synthesis, structure, and energetic materials properties of a series of aromatic peroxy acid compounds are described. Benzene-1,3,5-tris(carboperoxoic) acid is a highly sensitive primary energetic material, with impact and friction sensitivities similar to those of triacetone triperoxide. By contrast, benzene-1,4-bis(carboperoxoic) acid, 4-nitrobenzoperoxoic acid, and 3,5-dinitrobenzoperoxoic acid are much less sensitive, with impact and friction sensitivities close to those of the secondary energetic material 2,4,6-trinitrotoluene. Additionally, the calculated detonation velocities of 3,5-dinitrobenzoperoxoic acid and 2,4,6-trinitrobenzoperoxoic acid exceed that of 2,4,6-trinitrotoluene. The solid-state structure of 3,5-dinitrobenzoperoxoic acid contains intermolecular O-H⋅⋅⋅O hydrogen bonds and numerous N⋅⋅⋅O, C⋅⋅⋅O, and O⋅⋅⋅O close contacts. These attractive lattice interactions may account for the less sensitive nature of 3,5-dinitrobenzoperoxoic acid.

  3. Development and validation of an UPLC-MS/MS assay for quantitative analysis of the ghrelin receptor inverse agonist PF-5190457 in human or rat plasma and rat brain.

    PubMed

    Ghareeb, Mwlod; Leggio, Lorenzo; El-Kattan, Ayman; Akhlaghi, Fatemeh

    2015-07-01

    PF-5190457 is a ghrelin receptor inverse agonist that is currently undergoing clinical development for the treatment of alcoholism. Our aim was to develop and validate a simple and sensitive assay for quantitative analysis of PF-5190457 in human or rat plasma and rat brain using liquid chromatography-tandem mass spectrometry. The analyte and stable isotope internal standard were extracted from 50 μL plasma or rat brain homogenate by protein precipitation using 0.1% formic acid in acetonitrile. Chromatography was carried out on an Acquity UPLC BEH C18 (2.1 mm × 50 mm) column with 1.7 μm particle size and 130 Å pore size. The flow rate was 0.5 mL/min and total chromatographic run time was 2.2 min. The mobile phase consisted of a gradient mixture of water: acetonitrile 95:5% (v/v) containing 0.1% formic acid (solvent A) and 100% acetonitrile containing 0.1% formic acid (solvent B). Multiple reaction monitoring was carried out in positive electro-spray ionization mode using m/z 513.35 → 209.30 for PF-5190457 and m/z 518.47 → 214.43 for the internal standard. The recovery ranged from 102 to 118% with coefficient of variation (CV) less than 6% for all matrices. The calibration curves for all matrices were linear over the studied concentration range (R(2) ≥ 0.998, n = 3). The lower limit of quantification was 1 ng/mL in rat or human plasma and 0.75 ng/g in rat brain. Intra- and inter-run mean percent accuracies were between 85 and 115% and percent imprecision was ≤15%. The assays were successfully utilized to measure the concentration of PF-5190457 in pre-clinical and clinical pharmacology studies of the compound.

  4. A UPLC-MS Method for Simultaneous Determination of Geniposidic Acid, Two Lignans and Phenolics in Rat Plasma and its Application to Pharmacokinetic Studies of Eucommia ulmoides Extract in Rats.

    PubMed

    Li, Yongjun; Gong, Zipeng; Cao, Xu; Wang, Yonglin; Wang, Aimin; Zheng, Lin; Huang, Yong; Lan, Yanyu

    2016-10-01

    The bark of Eucommia ulmoides is a well-known Chinese herbal medicine that is used to regulate blood pressure and reduce blood sugar and fats, as well as an antioxidant and antimicrobial agent. Here we describe the development of a sensitive ultrahigh performance liquid chromatography-tandem mass spectrum method for the simultaneous determination of five major active ingredients of E. ulmoides bark extract, namely, geniposidic acid (GA), protocatechuic acid (PCA), chlorogenic acid (CA), (+)-pinoresinol di-O-β-D-glucopyranoside (PDG) and (+)-pinoresinol 4'-O-β-D-glucopyranoside (PG), in rat plasma. The preliminary steps in the plasma analysis were the addition of an internal standard and acidification (0.1 % formic acid), followed by protein precipitation with methanol. Separation of the active ingredients was performed on an ACQUITY UPLC® BEH C18 column (2.1 × 50 mm; internal diameter 1.7 µm) at a flow rate of 0.35 mL/min, with acetonitrile/water containing 0.1 % formic acid as the mobile phase. Detection was performed on a triple quadrupole tandem mass spectrometer via electrospray ionization source with positive and negative ionization modes. All calibration curves showed good linearity (r ≥ 0.997) over the concentration range with the low limit of quantification between 4.45 and 54.9 ng/mL. Precision was evaluated by intra- and inter-day assays, and the percentages of the relative standard deviation were all within 15 %. Extraction efficiency and matrix effect were 84.3-102.4 % and 98.1-112.2 %, respectively. The validated method was successfully applied to the pharmacokinetic study in rats after oral administration of E. ulmoides extract. The results indicate that the pharmacokinetic properties of GA differ from those of PCA, CA, PDG and PG, respectively.

  5. [Clinical interpretation of high sensitivity troponin T].

    PubMed

    Alquézar Arbé, Aitor; Santaló Bel, Miguel; Sionis, Alessandro

    2015-09-21

    Determination of cardiac troponin (cTn) is necessary for the diagnosis of acute myocardial infarction without ST segment elevation. However Tnc can be released in other clinical situations. The development of high-sensitive cTn T assays (hs-cTnT) improves the management of patients with suspected acute coronary syndrome. Here, we provide an overview of the diverse causes of hs-cTnT elevation and recommend strategies for the clinical interpretation of the test result.

  6. Highly sensitive catalytic spectrophotometric determination of ruthenium

    NASA Astrophysics Data System (ADS)

    Naik, Radhey M.; Srivastava, Abhishek; Prasad, Surendra

    2008-01-01

    A new and highly sensitive catalytic kinetic method (CKM) for the determination of ruthenium(III) has been established based on its catalytic effect on the oxidation of L-phenylalanine ( L-Pheala) by KMnO 4 in highly alkaline medium. The reaction has been followed spectrophotometrically by measuring the decrease in the absorbance at 526 nm. The proposed CKM is based on the fixed time procedure under optimum reaction conditions. It relies on the linear relationship where the change in the absorbance (Δ At) versus added Ru(III) amounts in the range of 0.101-2.526 ng ml -1 is plotted. Under the optimum conditions, the sensitivity of the proposed method, i.e. the limit of detection corresponding to 5 min is 0.08 ng ml -1, and decreases with increased time of analysis. The method is featured with good accuracy and reproducibility for ruthenium(III) determination. The ruthenium(III) has also been determined in presence of several interfering and non-interfering cations, anions and polyaminocarboxylates. No foreign ions interfered in the determination ruthenium(III) up to 20-fold higher concentration of foreign ions. In addition to standard solutions analysis, this method was successfully applied for the quantitative determination of ruthenium(III) in drinking water samples. The method is highly sensitive, selective and very stable. A review of recently published catalytic spectrophotometric methods for the determination of ruthenium(III) has also been presented for comparison.

  7. Multi-drug and metabolite quantification in postmortem blood by liquid chromatography-high-resolution mass spectrometry: comparison with nominal mass technology.

    PubMed

    Rosano, Thomas G; Na, Seo; Ihenetu, Kenneth; Swift, Thomas A; Wood, Michelle

    2014-10-01

    High-resolution mass spectrometry (HRMS) is being applied in postmortem drug screening as an alternative to nominal mass spectrometry, and additional evaluation in quantitative casework is needed. We report quantitative analysis of benzoylecgonine, citalopram, cocaethylene, cocaine, codeine, dextromethorphan, dihydrocodeine, diphenhydramine, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine, hydrocodone, hydromorphone, meperidine, methadone, morphine, oxycodone and oxymorphone in postmortem blood by ultra-performance liquid chromatography (UPLC)-MS(E)/time-of-flight (TOF). The method employs analyte-matched deuterated internal standardization and MS(E) acquisition of precursor and product ions at low (6 eV) and ramped (10-40 eV) collision energies, respectively. Quantification was performed using precursor ion data obtained with a mass extraction window of ± 5 ppm. Fragment and residual precursor ion acquisitions at ramped collision energies were evaluated as additional analyte identifiers. Extraction recovery of >60% and matrix effect of <20% were determined for all analytes and internal standards. Defined limits of detection (10 ng/mL) and quantification (25 ng/mL) were validated along with a linearity analytical range of 25-3,000 ng/mL (R(2) > 0.99) for all analytes. Parallel UPLC-MS(E)/TOF and UPLC-MS/MS analysis showed comparable precision and bias along with concordance of 253 positive (y = 1.002x + 1.523; R(2) = 0.993) and 2,269 negative analyte findings in 159 postmortem cases. Analytical performance and correlation studies demonstrate accurate quantification by UPLC-MS(E)/TOF and extended application of HRMS in postmortem casework. PMID:25217537

  8. UPLC-MS/MS method with automated on-line SPE for the isomer-specific quantification of the first-generation anti-HCV protease inhibitors in peripheral blood mononuclear cells.

    PubMed

    De Nicolò, Amedeo; Abdi, Adnan Mohamed; Boglione, Lucio; Baiett, Lorena; Allegra, Sarah; Di Perri, Giovanni; D'Avolio, Antonio

    2015-11-10

    HCV infection affects over 170 million people worldwide. The current standard for treatment of genotype 1 infection is the association of the first generation protease inhibitors boceprevir or telaprevir to ribavirin and peginterferon α. Although the response rate has been improved with these new drugs, some pharmacokinetic/pharmacodinamic issues emerged in the past years. To date, some analytical methods are available for the quantification of these drugs in plasma; however, the real active concentrations of the two drugs are those in hepatocytes. Being the withdrawal of hepatocytes too invasive, in this work we aimed to develop and validate a chromatographic method coupled with tandem mass spectrometry capable of quantifying boceprevir and telaprevir isomers in peripheral blood mononuclear cells, used as an "in-vivo" cellular model of compartmentalization. The method used an on-line solid phase extraction protocol based on the new OSM(®) platform and was fully validated following FDA guidelines. This method showed mean intra- and inter-day inaccuracy and imprecision both lower than 15%, high and stable recovery and contained matrix effect, with a run time of 6min, comprehensive of SPE extraction. The method was then applied on 35 real samples from patients treated with boceprevir or telaprevir, with good analytical performances, thus assessing its eligibility for a possible future routine use. Peculiar pharmacokinetic data have been observed, suggesting the usefulness of investigating intracellular pharmacokinetics of these drugs. Further studies will be required to test the correlation of intracellular concentrations with effectiveness and toxicity of triple therapy.

  9. UPLC-MS-based urine metabolomics reveals indole-3-lactic acid and phenyllactic acid as conserved biomarkers for alcohol-induced liver disease in the Ppara-null mouse model.

    PubMed

    Manna, Soumen K; Patterson, Andrew D; Yang, Qian; Krausz, Kristopher W; Idle, Jeffrey R; Fornace, Albert J; Gonzalez, Frank J

    2011-09-01

    Since the development and prognosis of alcohol-induced liver disease (ALD) vary significantly with genetic background, identification of a genetic background-independent noninvasive ALD biomarker would significantly improve screening and diagnosis. This study explored the effect of genetic background on the ALD-associated urinary metabolome using the Ppara-null mouse model on two different backgrounds, C57BL/6 (B6) and 129/SvJ (129S), along with their wild-type counterparts. Reversed-phase gradient UPLC-ESI-QTOF-MS analysis revealed that urinary excretion of a number of metabolites, such as ethylsulfate, 4-hydroxyphenylacetic acid, 4-hydroxyphenylacetic acid sulfate, adipic acid, pimelic acid, xanthurenic acid, and taurine, were background-dependent. Elevation of ethyl-β-d-glucuronide and N-acetylglycine was found to be a common signature of the metabolomic response to alcohol exposure in wild-type as well as in Ppara-null mice of both strains. However, increased excretion of indole-3-lactic acid and phenyllactic acid was found to be a conserved feature exclusively associated with the alcohol-treated Ppara-null mouse on both backgrounds that develop liver pathologies similar to the early stages of human ALD. These markers reflected the biochemical events associated with early stages of ALD pathogenesis. The results suggest that indole-3-lactic acid and phenyllactic acid are potential candidates for conserved and pathology-specific high-throughput noninvasive biomarkers for early stages of ALD.

  10. UPLC-MS/MS method with automated on-line SPE for the isomer-specific quantification of the first-generation anti-HCV protease inhibitors in peripheral blood mononuclear cells.

    PubMed

    De Nicolò, Amedeo; Abdi, Adnan Mohamed; Boglione, Lucio; Baiett, Lorena; Allegra, Sarah; Di Perri, Giovanni; D'Avolio, Antonio

    2015-11-10

    HCV infection affects over 170 million people worldwide. The current standard for treatment of genotype 1 infection is the association of the first generation protease inhibitors boceprevir or telaprevir to ribavirin and peginterferon α. Although the response rate has been improved with these new drugs, some pharmacokinetic/pharmacodinamic issues emerged in the past years. To date, some analytical methods are available for the quantification of these drugs in plasma; however, the real active concentrations of the two drugs are those in hepatocytes. Being the withdrawal of hepatocytes too invasive, in this work we aimed to develop and validate a chromatographic method coupled with tandem mass spectrometry capable of quantifying boceprevir and telaprevir isomers in peripheral blood mononuclear cells, used as an "in-vivo" cellular model of compartmentalization. The method used an on-line solid phase extraction protocol based on the new OSM(®) platform and was fully validated following FDA guidelines. This method showed mean intra- and inter-day inaccuracy and imprecision both lower than 15%, high and stable recovery and contained matrix effect, with a run time of 6min, comprehensive of SPE extraction. The method was then applied on 35 real samples from patients treated with boceprevir or telaprevir, with good analytical performances, thus assessing its eligibility for a possible future routine use. Peculiar pharmacokinetic data have been observed, suggesting the usefulness of investigating intracellular pharmacokinetics of these drugs. Further studies will be required to test the correlation of intracellular concentrations with effectiveness and toxicity of triple therapy. PMID:26291788

  11. Highly sensitive beam steering with plasmonic antenna

    PubMed Central

    Rui, Guanghao; Zhan, Qiwen

    2014-01-01

    In this work, we design and study a highly sensitive beam steering device that integrates a spiral plasmonic antenna with a subwavelength metallic waveguide. The short effective wavelength of the surface plasmon polaritons (SPPs) mode supported by the metallic waveguide is exploited to dramatically miniaturize the device and improve the sensitivity of the beam steering. Through introducing a tiny displacement of feed point with respect to the geometrical center of the spiral plasmonic antenna, the direction of the radiation can be steered at considerably high angles. Simulation results show that steering angles of 8°, 17° and 34° are obtainable for a displacement of 50 nm, 100 nm and 200 nm, respectively. Benefiting from the reduced device size and the shorter SPP wavelength, the beam steering sensitivity of the beam steering is improved by 10-fold compared with the case reported previously. This miniature plasmonic beam steering device may find many potential applications in quantum optical information processing and integrated photonic circuits. PMID:25091405

  12. [Clinical interpretation of high sensitivity troponin T].

    PubMed

    Alquézar Arbé, Aitor; Santaló Bel, Miguel; Sionis, Alessandro

    2015-09-21

    Determination of cardiac troponin (cTn) is necessary for the diagnosis of acute myocardial infarction without ST segment elevation. However Tnc can be released in other clinical situations. The development of high-sensitive cTn T assays (hs-cTnT) improves the management of patients with suspected acute coronary syndrome. Here, we provide an overview of the diverse causes of hs-cTnT elevation and recommend strategies for the clinical interpretation of the test result. PMID:25620025

  13. Photodetector having high speed and sensitivity

    DOEpatents

    Morse, Jeffrey D.; Mariella, Jr., Raymond P.

    1991-01-01

    The present invention provides a photodetector having an advantageous combination of sensitivity and speed; it has a high sensitivity while retaining high speed. In a preferred embodiment, visible light is detected, but in some embodiments, x-rays can be detected, and in other embodiments infrared can be detected. The present invention comprises a photodetector having an active layer, and a recombination layer. The active layer has a surface exposed to light to be detected, and comprises a semiconductor, having a bandgap graded so that carriers formed due to interaction of the active layer with the incident radiation tend to be swept away from the exposed surface. The graded semiconductor material in the active layer preferably comprises Al.sub.1-x Ga.sub.x As. An additional sub-layer of graded In.sub.1-y Ga.sub.y As may be included between the Al.sub.1-x Ga.sub.x As layer and the recombination layer. The recombination layer comprises a semiconductor material having a short recombination time such as a defective GaAs layer grown in a low temperature process. The recombination layer is positioned adjacent to the active layer so that carriers from the active layer tend to be swept into the recombination layer. In an embodiment, the photodetector may comprise one or more additional layers stacked below the active and recombination layers. These additional layers may include another active layer and another recombination layer to absorb radiation not absorbed while passing through the first layers. A photodetector having a stacked configuration may have enhanced sensitivity and responsiveness at selected wavelengths such as infrared.

  14. High speed curved position sensitive detector

    DOEpatents

    Hendricks, Robert W.; Wilson, Jack W.

    1989-01-01

    A high speed curved position sensitive porportional counter detector for use in x-ray diffraction, the detection of 5-20 keV photons and the like. The detector employs a planar anode assembly of a plurality of parallel metallic wires. This anode assembly is supported between two cathode planes, with at least one of these cathode planes having a serpentine resistive path in the form of a meander having legs generally perpendicular to the anode wires. This meander is produced by special microelectronic fabrication techniques whereby the meander "wire" fans outwardly at the cathode ends to produce the curved aspect of the detector, and the legs of the meander are small in cross-section and very closely spaced whereby a spatial resolution of about 50 .mu.m can be achieved. All of the other performance characteristics are about as good or better than conventional position sensitive proportional counter type detectors. Count rates of up to 40,000 counts per second with 0.5 .mu.s shaping time constants are achieved.

  15. High sensitivity ancilla assisted nanoscale DC magnetometry

    NASA Astrophysics Data System (ADS)

    Liu, Yixiang; Ajoy, Ashok; Marseglia, Luca; Saha, Kasturi; Cappellaro, Paola

    2016-05-01

    Sensing slowly varying magnetic fields are particularly relevant to many real world scenarios, where the signals of interest are DC or close to static. Nitrogen Vacancy (NV) centers in diamond are a versatile platform for such DC magnetometry on nanometer length scales. Using NV centers, the standard technique for measuring DC magnetic fields is via the Ramsey protocol, where sensitivities can approach better than 1 μ T/vHz, but are limited by the sensor fast dephasing time T2*. In this work we instead present a method of sensing DC magnetic fields that is intrinsically limited by the much longer T2 coherence time. The method exploits a strongly-coupled ancillary nuclear spin to achieve high DC field sensitivities potentially exceeding that of the Ramsey method. In addition, through this method we sense the perpendicular component of the DC magnetic field, which in conjunction with the parallel component sensed by the Ramsey method provides a valuable tool for vector DC magnetometry at the nanoscale.

  16. Highly Sensitive Electro-Optic Modulators

    SciTech Connect

    DeVore, Peter S

    2015-10-26

    There are very important diagnostic and communication applications that receive faint electrical signals to be transmitted over long distances for capture. Optical links reduce bandwidth and distance restrictions of metal transmission lines; however, such signals are only weakly imprinted onto the optical carrier, resulting in low fidelity transmission. Increasing signal fidelity often necessitates insertion of radio-frequency (RF) amplifiers before the electro-optic modulator, but (especially at high frequencies) RF amplification results in large irreversible distortions. We have investigated the feasibility of a Sensitive and Linear Modulation by Optical Nonlinearity (SALMON) modulator to supersede RF-amplified modulators. SALMON uses cross-phase modulation, a manifestation of the Kerr effect, to enhance the modulation depth of an RF-modulated optical wave. This ultrafast process has the potential to result in less irreversible distortions as compared to a RF-amplified modulator due to the broadband nature of the Kerr effect. Here, we prove that a SALMON modulator is a feasible alternative to an RFamplified modulator, by demonstrating a sensitivity enhancement factor greater than 20 and significantly reduced distortion.

  17. Highly sensitive immunosensor using a nanofluidic preconcentrator.

    PubMed

    Liao, Ke-Pan; Sung, Kung-Bin

    2008-01-01

    This paper presents a micro-/nanofluidic biochip for enhanced sensitivity of immunoassay. By using a protein preconcentrator based on nanofluidic filters, we greatly improve the binding kinetics of immunoassay. A shallow nanofluidic channel connecting two microchannels for ion-selective filter is etched on the glass surface and sealed by PDMS/Glass irreversible bonding treated with O2 plasma. Our device achieved a 10(5) fold increase in protein concentration with 12 minutes of preconcentration. For applying the preconcentrator to immunoassay, we fabricated a novel device with a thin layer of Au sputtered near the nanochannel to provide a substrate for antibody immobilization and a sensing area at the site of highly concentrated proteins. After increasing the concentration of antibody and target antigen by multiple sample preconcentration steps, the binding kinetics of immunoassay can be significantly improved.

  18. A high sensitive roll angle interferometer

    NASA Astrophysics Data System (ADS)

    Le, Yanfen; Hou, Wenmei; Hu, Kai; Ju, Aisong

    2013-01-01

    A roll angle interferometer with high sensitivity is designed in this paper. Two sets of centrosymmetric beams are used to travel through the measurement and reference arms of the roll angle interferometer which contains two specific optical devices: wedge prism assembly and wedge mirror assembly. The optical path change in both arms caused by roll is converted into phase shift which can be measured by interferometer. Because of the adoption of the centrosymmetric measurement structure, the straightness errors, yaw error and pitch error can be avoided and the dead path is minimized, so that the stability and the accuracy of the measurement can be greatly enhanced. The resolution for the roll measurement is about 0.006″ with the measurement range of ±1°.

  19. Highly sensitive silicon microreactor for catalyst testing

    SciTech Connect

    Henriksen, Toke R.; Hansen, Ole; Olsen, Jakob L.; Vesborg, Peter; Chorkendorff, Ib

    2009-12-15

    A novel microfabricated chemical reactor for highly sensitive measurements of catalytic activity and surface kinetics is presented. The reactor is fabricated in a silicon chip and is intended for gas-phase reactions at pressures ranging from 0.1 to 5.0 bar. A high sensitivity is obtained by directing the entire gas flow through the catalyst bed to a mass spectrometer, thus ensuring that nearly all reaction products are present in the analyzed gas flow. Although the device can be employed for testing a wide range of catalysts, the primary aim of the design is to allow characterization of model catalysts which can only be obtained in small quantities. Such measurements are of significant fundamental interest but are challenging because of the low surface areas involved. The relationship between the reaction zone gas flow and the pressure in the reaction zone is investigated experimentally. A corresponding theoretical model is presented, and the gas flow through an on-chip flow-limiting capillary is predicted to be in the intermediate regime. The experimental data for the gas flow are found to be in good agreement with the theoretical model. At typical experimental conditions, the total gas flow through the reaction zone is around 3x10{sup 14} molecules s{sup -1}, corresponding to a gas residence time in the reaction zone of about 11 s. To demonstrate the operation of the microreactor, CO oxidation on low-area platinum thin film circles is employed as a test reaction. Using temperature ramping, it is found that platinum catalysts with areas as small as 15 {mu}m{sup 2} are conveniently characterized with the device.

  20. Face Transplantation in a Highly Sensitized Recipient.

    PubMed

    Chandraker, Anil; Arscott, Ramon; Murphy, George; Lian, Christine; Bueno, Ericka; Marty, Francisco; Rennke, Helmut; Milford, Edgar; Tullius, Stefan; Pomahac, Bodhan

    2016-05-01

    Face transplantation was performed in a highly sensitized recipient with positive preoperative crossmatch and subsequent antibody-mediated rejection. The recipient was a 45-year-old female with extensive conventional reconstructions after chemical burns over the majority of the body. Residual quality of life and facial functions were poor. Levels of circulating anti-human leukocyte antigen (HLA) antibodies were high, and panel reactive antibody score was 98%. A potential donor was identified; however, with positive T and B cell flow crossmatches. The transplant team proceeded with face transplantation from this donor, under tailored immune suppression and with available salvage options. The operation was successful. Plasmapheresis and induction immune suppression (i.e., thymoglobulin followed by mycophenolate mofetil, tacrolimus, and steroids) were provided. Five days later, there was significant facial swelling, rising anti-HLA antibody titers, and unprecedented evidence of C4d deposits on skin. High doses of steroids and thymoglobulin were provided; however, rejection increased such that by day 19 it was diagnosed grade III in the BANFF scale. After stopping thymoglobulin because of serum sickness, combination therapy of plasmapheresis, eculizumab, bortezomib, and alemtuzumab was provided. HLA antibody levels decreased while swelling and redness improved. At 3 months, there were no longer signs of rejection on biopsy. PMID:27168576

  1. Transportable high sensitivity small sample radiometric calorimeter

    SciTech Connect

    Wetzel, J.R.; Biddle, R.S.; Cordova, B.S.; Sampson, T.E.; Dye, H.R.; McDow, J.G.

    1998-12-31

    A new small-sample, high-sensitivity transportable radiometric calorimeter, which can be operated in different modes, contains an electrical calibration method, and can be used to develop secondary standards, will be described in this presentation. The data taken from preliminary tests will be presented to indicate the precision and accuracy of the instrument. The calorimeter and temperature-controlled bath, at present, require only a 30-in. by 20-in. tabletop area. The calorimeter is operated from a laptop computer system using unique measurement module capable of monitoring all necessary calorimeter signals. The calorimeter can be operated in the normal calorimeter equilibration mode, as a comparison instrument, using twin chambers and an external electrical calibration method. The sample chamber is 0.75 in (1.9 cm) in diameter by 2.5 in. (6.35 cm) long. This size will accommodate most {sup 238}Pu heat standards manufactured in the past. The power range runs from 0.001 W to <20 W. The high end is only limited by sample size.

  2. Demonstration of high sensitivity laser ranging system

    NASA Technical Reports Server (NTRS)

    Millar, Pamela S.; Christian, Kent D.; Field, Christopher T.

    1994-01-01

    We report on a high sensitivity semiconductor laser ranging system developed for the Gravity and Magnetic Earth Surveyor (GAMES) for measuring variations in the planet's gravity field. The GAMES laser ranging instrument (LRI) consists of a pair of co-orbiting satellites, one which contains the laser transmitter and receiver and one with a passive retro-reflector mounted in an drag-stabilized housing. The LRI will range up to 200 km in space to the retro-reflector satellite. As the spacecraft pair pass over the spatial variations in the gravity field, they experience along-track accelerations which change their relative velocity. These time displaced velocity changes are sensed by the LRI with a resolution of 20-50 microns/sec. In addition, the pair may at any given time be drifting together or apart at a rate of up to 1 m/sec, introducing a Doppler shift into the ranging signals. An AlGaAs laser transmitter intensity modulated at 2 GHz and 10 MHz is used as fine and medium ranging channels. Range is measured by comparing phase difference between the transmit and received signals at each frequency. A separate laser modulated with a digital code, not reported in this paper, will be used for coarse ranging to unambiguously determine the distance up to 200 km.

  3. An ultra-high performance liquid chromatography-tandem mass spectrometric assay for quantifying 3-ketocholanoic acid: Application to the human liver microsomal CYP3A-dependent lithocholic acid 3-oxidation assay.

    PubMed

    Bansal, Sumit; Chai, Swee Fen; Lau, Aik Jiang

    2016-06-15

    Lithocholic acid (LCA), a hepatotoxic and carcinogenic bile acid, is metabolized to 3-ketocholanoic acid (3-KCA) by cytochrome P450 3A (CYP3A). In the present study, the objectives were to develop and validate an ultra-high performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method to quantify 3-KCA and apply it to the human liver microsomal CYP3A-dependent LCA 3-oxidation assay. Chromatographic separation was achieved on a Waters ACQUITY™ UPLC C18 column (50×2.1mm, 1.7μm) with a gradient system consisting of 0.1% v/v formic acid in water (solvent A) and 0.1% v/v formic acid in acetonitrile (solvent B). The retention time was 3.73min for 3-KCA and 2.73min for cortisol (internal standard). Positive electrospray ionization with multiple reaction monitoring (MRM) mode was used to quantify 3-KCA (m/z 375.4→135.2) and cortisol (m/z 363.5→121.0). The limit of detection of 3-KCA was 10μM, the lower limit of quantification was 33.3μM, and the calibration curve was linear from 0.05-10μM with r(2)>0.99. Intra-day and inter-day accuracy and precision were <13.7%. The quality control samples were stable when assessed after 4h at room temperature, 24h at 4°C, 14days at -20°C, and three freeze-thaw cycles. The liver microsomal matrix did not affect 3-KCA quantification. The amount of KCA formed in the human liver microsomal LCA 3-oxidation assay was linear with respect to the amount of microsomal protein (up to 40μg) and incubation time (5-30min). Enzyme kinetics experiment indicated that LCA 3-oxidation followed the Michaelis-Menten model with an apparent Km of 26±7μM and Vmax of 303±50pmol/min/mg protein. This novel UPLC-MS/MS method for quantifying 3-KCA offers a specific, sensitive, and fast approach to determine liver microsomal LCA 3-oxidation.

  4. A simple sheathless CE-MS interface with a sub-micrometer electrical contact fracture for sensitive analysis of peptide and protein samples.

    PubMed

    Nguyen, Tam T T N; Petersen, Nickolaj J; Rand, Kasper D

    2016-09-14

    Online coupling of capillary electrophoresis (CE) to electrospray ionization mass spectrometry (MS) has shown considerable potential, however, technical challenges have limited its use. In this study, we have developed a simple and sensitive sheathless CE-MS interface based on the novel concept of forming a sub-micrometer fracture directly in the capillary. The simple interface design allowed the generation of a stable ESI spray capable of ionization at low nanoliter flow-rates (45-90 nL/min) for high sensitivity MS analysis of challenging samples like those containing proteins and peptides. By analysis of a model peptide (leucine enkephalin), a limit of detection (LOD) of 0.045 pmol/μL (corresponding to 67 attomol in a sample volume of ∼15 nL) was obtained. The merit of the CE-MS approach was demonstrated by analysis of bovine serum albumin (BSA) tryptic peptides. A well-resolved separation profile was achieved and comparable sequence coverage was obtained by the CE-MS method (73%) compared to a representative UPLC-MS method (77%). The CE-MS interface was subsequently used to analyse a more complex sample of pharmaceutically relevant human proteins including insulin, tissue factor and α-synuclein. Efficient separation and protein ESI mass spectra of adequate quality could be achieved using only a small amount of sample (30 fmol). In addition, analysis of ubiquitin samples under both native and denatured conditions, indicate that the CE-MS setup can facilitate native MS applications to probe the conformational properties of proteins. Thus, the described CE-MS setup should be useful for a wide range of high-sensitivity applications in protein research. PMID:27566351

  5. Rapid and sensitive hormonal profiling of complex plant samples by liquid chromatography coupled to electrospray ionization tandem mass spectrometry

    PubMed Central

    2011-01-01

    Background Plant hormones play a pivotal role in several physiological processes during a plant's life cycle, from germination to senescence, and the determination of endogenous concentrations of hormones is essential to elucidate the role of a particular hormone in any physiological process. Availability of a sensitive and rapid method to quantify multiple classes of hormones simultaneously will greatly facilitate the investigation of signaling networks in controlling specific developmental pathways and physiological responses. Due to the presence of hormones at very low concentrations in plant tissues (10-9 M to 10-6 M) and their different chemistries, the development of a high-throughput and comprehensive method for the determination of hormones is challenging. Results The present work reports a rapid, specific and sensitive method using ultrahigh-performance liquid chromatography coupled to electrospray ionization tandem spectrometry (UPLC/ESI-MS/MS) to analyze quantitatively the major hormones found in plant tissues within six minutes, including auxins, cytokinins, gibberellins, abscisic acid, 1-amino-cyclopropane-1-carboxyic acid (the ethylene precursor), jasmonic acid and salicylic acid. Sample preparation, extraction procedures and UPLC-MS/MS conditions were optimized for the determination of all plant hormones and are summarized in a schematic extraction diagram for the analysis of small amounts of plant material without time-consuming additional steps such as purification, sample drying or re-suspension. Conclusions This new method is applicable to the analysis of dynamic changes in endogenous concentrations of hormones to study plant developmental processes or plant responses to biotic and abiotic stresses in complex tissues. An example is shown in which a hormone profiling is obtained from leaves of plants exposed to salt stress in the aromatic plant, Rosmarinus officinalis. PMID:22098763

  6. Advanced assessment of the physicochemical characteristics of Remicade® and Inflectra® by sensitive LC/MS techniques

    PubMed Central

    Fang, Jing; Doneanu, Catalin; Alley, William R.; Yu, Ying Qing; Beck, Alain; Chen, Weibin

    2016-01-01

    ABSTRACT In this study, we demonstrate the utility of ultra-performance liquid chromatography coupled to mass spectrometry (MS) and ion-mobility spectrometry (IMS) to characterize and compare reference and biosimilar monoclonal antibodies (mAbs) at an advanced level. Specifically, we focus on infliximab and compared the glycan profiles, higher order structures, and their host cell proteins (HCPs) of the reference and biosimilar products, which have the brand names Remicade® and Inflectra®, respectively. Overall, the biosimilar attributes mirrored those of the reference product to a very high degree. The glycan profiling analysis demonstrated a high degree of similarity, especially among the higher abundance glycans. Some differences were observed for the lower abundance glycans. Glycans terminated with N-glycolylneuraminic acid were generally observed to be at higher normalized abundance levels on the biosimilar mAb, while those possessing α-linked galactose pairs were more often expressed at higher levels on the reference molecule. Hydrogen deuterium exchange (HDX) analyses further confirmed the higher-order similarity of the 2 molecules. These results demonstrated only very slight differences between the 2 products, which, interestingly, seemed to be in the area where the N-linked glycans reside. The HCP analysis by a 2D-UPLC IMS-MS approach revealed that the same 2 HCPs were present in both mAb samples. Our ability to perform these types of analyses and acquire insightful data for biosimilarity assessment is based upon our highly sensitive UPLC MS and IMS methods. PMID:27260215

  7. A case of high noise sensitivity

    NASA Astrophysics Data System (ADS)

    Murata, M.; Sakamoto, H.

    1995-10-01

    A case of noise sensitivity with a five-year follow-up period is reported. The patient was a 34-year-old single man who was diagnosed as having psychosomatic disorder triggered by two stressful life events in rapid succession with secondary hypersensitivity to noise. Hypersensitivity to light and cold also developed later in the clinical course. The auditory threshold was within the normal range. The discomfort threshold as a measure of the noise sensitivity secondary to mental illness was measured repeatedly using test tone of audiometry. The discomfort threshold varied depending upon his mental status, ranging from 40-50 dB in the comparatively poorer mental state to 70-95 dB in the relatively good mental state. The features of noise sensitivity, including that secondary to mental illness, are discussed.

  8. High sensitivity leak detection method and apparatus

    DOEpatents

    Myneni, Ganapatic R.

    1994-01-01

    An improved leak detection method is provided that utilizes the cyclic adsorption and desorption of accumulated helium on a non-porous metallic surface. The method provides reliable leak detection at superfluid helium temperatures. The zero drift that is associated with residual gas analyzers in common leak detectors is virtually eliminated by utilizing a time integration technique. The sensitivity of the apparatus of this disclosure is capable of detecting leaks as small as 1.times.10.sup.-18 atm cc sec.sup.-1.

  9. High sensitivity leak detection method and apparatus

    DOEpatents

    Myneni, G.R.

    1994-09-06

    An improved leak detection method is provided that utilizes the cyclic adsorption and desorption of accumulated helium on a non-porous metallic surface. The method provides reliable leak detection at superfluid helium temperatures. The zero drift that is associated with residual gas analyzers in common leak detectors is virtually eliminated by utilizing a time integration technique. The sensitivity of the apparatus of this disclosure is capable of detecting leaks as small as 1 [times] 10[sup [minus]18] atm cc sec[sup [minus]1]. 2 figs.

  10. Highly sensitive genotyping using artificial riboregulator system.

    PubMed

    Narita, Atsushi; Ogawa, Kazumasa; Sando, Shinsuke; Aoyama, Yasuhiro

    2005-01-01

    A molecular-beacon-type riboregulator (mRNA) was applied to multiply catalytic gene sensing. It consists of a reporter gene for firefly protein luciferase and, upstream thereof, a regulator hairpin domain composed of an RBS/anti-RBS stem (RBS = ribosome binding site) and a loop which is complementary to the target. The sensing of target gene, using an unmodified RNA or even dsDNA as a probe with a chemiluminescence output, was demonstrated with a sensitivity at < or = 50 fmol of the target and a single nucleotide resolution.

  11. A high sensitive phosphor for dosimetric applications

    SciTech Connect

    Kore, Bhushan P. Dhoble, S. J.; Dhoble, N. S.; Lochab, S. P.

    2015-06-24

    In this study a novel TL phosphor CaMg{sub 3}(SO{sub 4}){sub 4}:Dy{sup 3+} was prepared by acid distillation method. The TL response of this phosphor towards γ-rays and carbon ion beam was tested. Good dosimetric glow curve was observed which is stable against both the type of radiations. The CaMg{sub 3}(SO{sub 4}){sub 4}:Dy{sup 3+} phosphor doped with 0.2 mol% of Dy{sup 3+}, irradiated with γ-ray shows nearly equal sensitivity to that of commercially available CaSO{sub 4}:Dy TLD phosphor whereas 3.5 times more sensitivity than CaSO{sub 4}:Dy, when irradiated with carbon ion beam. The change in glow peak intensities and glow peak temperature with variation in irradiation species and energy of ion beam is discussed here. The effect of these on trapping parameters is also illustrated.

  12. High-Sensitivity GaN Microchemical Sensors

    NASA Technical Reports Server (NTRS)

    Son, Kyung-ah; Yang, Baohua; Liao, Anna; Moon, Jeongsun; Prokopuk, Nicholas

    2009-01-01

    Systematic studies have been performed on the sensitivity of GaN HEMT (high electron mobility transistor) sensors using various gate electrode designs and operational parameters. The results here show that a higher sensitivity can be achieved with a larger W/L ratio (W = gate width, L = gate length) at a given D (D = source-drain distance), and multi-finger gate electrodes offer a higher sensitivity than a one-finger gate electrode. In terms of operating conditions, sensor sensitivity is strongly dependent on transconductance of the sensor. The highest sensitivity can be achieved at the gate voltage where the slope of the transconductance curve is the largest. This work provides critical information about how the gate electrode of a GaN HEMT, which has been identified as the most sensitive among GaN microsensors, needs to be designed, and what operation parameters should be used for high sensitivity detection.

  13. Linearization strategies for high sensitivity magnetoresistive sensors

    NASA Astrophysics Data System (ADS)

    Silva, Ana V.; Leitao, Diana C.; Valadeiro, João; Amaral, José; Freitas, Paulo P.; Cardoso, Susana

    2015-10-01

    Ultrasensitive magnetic field sensors envisaged for applications on biomedical imaging require the detection of low-intensity and low-frequency signals. Therefore linear magnetic sensors with enhanced sensitivity low noise levels and improved field detection at low operating frequencies are necessary. Suitable devices can be designed using magnetoresistive sensors, with room temperature operation, adjustable detected field range, CMOS compatibility and cost-effective production. The advent of spintronics set the path to the technological revolution boosted by the storage industry, in particular by the development of read heads using magnetoresistive devices. New multilayered structures were engineered to yield devices with linear output. We present a detailed study of the key factors influencing MR sensor performance (materials, geometries and layout strategies) with focus on different linearization strategies available. Furthermore strategies to improve sensor detection levels are also addressed with best reported values of ˜40 pT/√Hz at 30 Hz, representing a step forward the low field detection at room temperature.

  14. Design optimization of high pressure and high temperature piezoresistive pressure sensor for high sensitivity

    NASA Astrophysics Data System (ADS)

    Niu, Zhe; Zhao, Yulong; Tian, Bian

    2014-01-01

    This paper describes a design method for optimizing sensitivity of piezoresistive pressure sensor in high-pressure and high-temperature environment. In order to prove the method, a piezoresistive pressure sensor (HPTSS) is designed. With the purpose of increasing sensitivity and to improve the measurement range, the piezoresistive sensor adopts rectangular membrane and thick film structure. The configuration of piezoresistors is arranged according to the characteristic of the rectangular membrane. The structure and configuration of the sensor chip are analyzed theoretically and simulated by the finite element method. This design enables the sensor chip to operate in high pressure condition (such as 150 MPa) with a high sensitivity and accuracy. The silicon on insulator wafer is selected to guarantee the thermo stability of the sensor chip. In order to optimize the fabrication and improve the yield of production, an electric conduction step is devised. Series of experiments demonstrates a favorable linearity of 0.13% and a high accuracy of 0.48%. And the sensitivity of HTPSS is about six times as high as a conventional square-membrane sensor chip in the experiment. Compared with the square-membrane pressure sensor and current production, the strength of HPTTS lies in sensitivity and measurement. The performance of the HPTSS indicates that it could be an ideal candidate for high-pressure and high-temperature sensing in real application.

  15. Design optimization of high pressure and high temperature piezoresistive pressure sensor for high sensitivity.

    PubMed

    Niu, Zhe; Zhao, Yulong; Tian, Bian

    2014-01-01

    This paper describes a design method for optimizing sensitivity of piezoresistive pressure sensor in high-pressure and high-temperature environment. In order to prove the method, a piezoresistive pressure sensor (HPTSS) is designed. With the purpose of increasing sensitivity and to improve the measurement range, the piezoresistive sensor adopts rectangular membrane and thick film structure. The configuration of piezoresistors is arranged according to the characteristic of the rectangular membrane. The structure and configuration of the sensor chip are analyzed theoretically and simulated by the finite element method. This design enables the sensor chip to operate in high pressure condition (such as 150 MPa) with a high sensitivity and accuracy. The silicon on insulator wafer is selected to guarantee the thermo stability of the sensor chip. In order to optimize the fabrication and improve the yield of production, an electric conduction step is devised. Series of experiments demonstrates a favorable linearity of 0.13% and a high accuracy of 0.48%. And the sensitivity of HTPSS is about six times as high as a conventional square-membrane sensor chip in the experiment. Compared with the square-membrane pressure sensor and current production, the strength of HPTTS lies in sensitivity and measurement. The performance of the HPTSS indicates that it could be an ideal candidate for high-pressure and high-temperature sensing in real application.

  16. A high-sensitivity neutron counter and waste-drum counting with the high-sensitivity neutron instrument

    SciTech Connect

    Hankins, D.E.; Thorngate, J.H.

    1993-04-01

    At Lawrence Livermore National Laboratory (LLNL), a highly sensitive neutron counter was developed that can detect and accurately measure the neutrons from small quantities of plutonium or from other low-level neutron sources. This neutron counter was originally designed to survey waste containers leaving the Plutonium Facility. However, it has proven to be useful in other research applications requiring a high-sensitivity neutron instrument.

  17. High sensitivity optical waveguide accelerometer based on Fano resonance.

    PubMed

    Wan, Fenghua; Qian, Guang; Li, Ruozhou; Tang, Jie; Zhang, Tong

    2016-08-20

    An optical waveguide accelerometer based on tunable asymmetrical Fano resonance in a ring-resonator-coupled Mach-Zehnder interferometer (MZI) is proposed and analyzed. A Fano resonance accelerometer has a relatively large workspace of coupling coefficients with high sensitivity, which has potential application in inertial navigation, missile guidance, and attitude control of satellites. Due to the interference between a high-Q resonance pathway and a coherent background pathway, a steep asymmetric line shape is generated, which greatly improves the sensitivity of this accelerometer. The sensitivity of the accelerometer is about 111.75 mW/g. A 393-fold increase in sensitivity is achieved compared with a conventional MZI accelerometer and is approximately equal to the single ring structure.

  18. High sensitivity optical waveguide accelerometer based on Fano resonance.

    PubMed

    Wan, Fenghua; Qian, Guang; Li, Ruozhou; Tang, Jie; Zhang, Tong

    2016-08-20

    An optical waveguide accelerometer based on tunable asymmetrical Fano resonance in a ring-resonator-coupled Mach-Zehnder interferometer (MZI) is proposed and analyzed. A Fano resonance accelerometer has a relatively large workspace of coupling coefficients with high sensitivity, which has potential application in inertial navigation, missile guidance, and attitude control of satellites. Due to the interference between a high-Q resonance pathway and a coherent background pathway, a steep asymmetric line shape is generated, which greatly improves the sensitivity of this accelerometer. The sensitivity of the accelerometer is about 111.75 mW/g. A 393-fold increase in sensitivity is achieved compared with a conventional MZI accelerometer and is approximately equal to the single ring structure. PMID:27556984

  19. An Automated High-Throughput Metabolic Stability Assay Using an Integrated High-Resolution Accurate Mass Method and Automated Data Analysis Software.

    PubMed

    Shah, Pranav; Kerns, Edward; Nguyen, Dac-Trung; Obach, R Scott; Wang, Amy Q; Zakharov, Alexey; McKew, John; Simeonov, Anton; Hop, Cornelis E C A; Xu, Xin

    2016-10-01

    Advancement of in silico tools would be enabled by the availability of data for metabolic reaction rates and intrinsic clearance (CLint) of a diverse compound structure data set by specific metabolic enzymes. Our goal is to measure CLint for a large set of compounds with each major human cytochrome P450 (P450) isozyme. To achieve our goal, it is of utmost importance to develop an automated, robust, sensitive, high-throughput metabolic stability assay that can efficiently handle a large volume of compound sets. The substrate depletion method [in vitro half-life (t1/2) method] was chosen to determine CLint The assay (384-well format) consisted of three parts: 1) a robotic system for incubation and sample cleanup; 2) two different integrated, ultraperformance liquid chromatography/mass spectrometry (UPLC/MS) platforms to determine the percent remaining of parent compound, and 3) an automated data analysis system. The CYP3A4 assay was evaluated using two long t1/2 compounds, carbamazepine and antipyrine (t1/2 > 30 minutes); one moderate t1/2 compound, ketoconazole (10 < t1/2 < 30 minutes); and two short t1/2 compounds, loperamide and buspirone (t½ < 10 minutes). Interday and intraday precision and accuracy of the assay were within acceptable range (∼12%) for the linear range observed. Using this assay, CYP3A4 CLint and t1/2 values for more than 3000 compounds were measured. This high-throughput, automated, and robust assay allows for rapid metabolic stability screening of large compound sets and enables advanced computational modeling for individual human P450 isozymes. PMID:27417180

  20. An Automated High-Throughput Metabolic Stability Assay Using an Integrated High-Resolution Accurate Mass Method and Automated Data Analysis Software

    PubMed Central

    Shah, Pranav; Kerns, Edward; Nguyen, Dac-Trung; Obach, R. Scott; Wang, Amy Q.; Zakharov, Alexey; McKew, John; Simeonov, Anton; Hop, Cornelis E. C. A.

    2016-01-01

    Advancement of in silico tools would be enabled by the availability of data for metabolic reaction rates and intrinsic clearance (CLint) of a diverse compound structure data set by specific metabolic enzymes. Our goal is to measure CLint for a large set of compounds with each major human cytochrome P450 (P450) isozyme. To achieve our goal, it is of utmost importance to develop an automated, robust, sensitive, high-throughput metabolic stability assay that can efficiently handle a large volume of compound sets. The substrate depletion method [in vitro half-life (t1/2) method] was chosen to determine CLint. The assay (384-well format) consisted of three parts: 1) a robotic system for incubation and sample cleanup; 2) two different integrated, ultraperformance liquid chromatography/mass spectrometry (UPLC/MS) platforms to determine the percent remaining of parent compound, and 3) an automated data analysis system. The CYP3A4 assay was evaluated using two long t1/2 compounds, carbamazepine and antipyrine (t1/2 > 30 minutes); one moderate t1/2 compound, ketoconazole (10 < t1/2 < 30 minutes); and two short t1/2 compounds, loperamide and buspirone (t½ < 10 minutes). Interday and intraday precision and accuracy of the assay were within acceptable range (∼12%) for the linear range observed. Using this assay, CYP3A4 CLint and t1/2 values for more than 3000 compounds were measured. This high-throughput, automated, and robust assay allows for rapid metabolic stability screening of large compound sets and enables advanced computational modeling for individual human P450 isozymes. PMID:27417180

  1. Near-infrared squaraine co-sensitizer for high-efficiency dye-sensitized solar cells.

    PubMed

    Rao, G Hanumantha; Venkateswararao, A; Giribabu, L; Han, Liyuan; Bedja, Idriss; Gupta, Ravindra Kumar; Islam, Ashraful; Singh, Surya Prakash

    2016-06-01

    A combination of squaraine-based dyes (SPSQ1 and SPSQ2) and a ruthenium-based dye (N3) were chosen as co-sensitizers to construct efficient dye-sensitized solar cells. The co-sensitization of squaraine dyes with N3 enhanced their light-harvesting properties as a result of the broad spectral coverage in the region 350-800 nm. The co-sensitized solar cells based on SPSQ2 + N3 showed the highest short circuit current density of 17.10 mA cm(-2), an open circuit voltage of 0.66 V and a fill factor of 0.73, resulting in the highest power conversion efficiency of 8.2%, which is higher than that of the dye-sensitized solar cells based on the individual SPSQ1 and SPSQ2 dyes. The high power conversion efficiency of SPSQ2 + N3 was ascribed to its good light-harvesting properties, which resulted from its broader incident photon current conversion spectrum than that of the individual dyes. The high electron life time and electron recombination, which were the main causes of the higher efficiency of the device, were successfully analysed and correlated using transient absorption spectrometry and intensity-modulated photovoltage spectrometry.

  2. Highly sensitive tactile sensors integrated with organic transistors

    NASA Astrophysics Data System (ADS)

    Kim, Jiseok; Nga Ng, Tse; Soo Kim, Woo

    2012-09-01

    This paper presents a highly sensitive capacitive pressure sensor composed of a polymer dielectric film with a nano-needle structure. The nano-needle polymer films were prepared by facile fabrication methods including breath figures formation followed by stamping. The pressure sensitivity of the sensor reached 1.76 kPa-1 in the low pressure range (<1 kPa), which is comparable to the sensitivity of human skin. Analysis of the geometries and densities effect was shown, and the nano-needle film showed better sensitivity in comparison to films with hemispherical or conical structures. The pressure sensors were integrated with printed organic thin film transistors to enable flexible, large-area tactile sensing applications.

  3. A sensitive and high dynamic range cw laser power meter

    NASA Astrophysics Data System (ADS)

    Krishnan, S.; Bindra, K. S.; Oak, S. M.

    2008-12-01

    We report the design of a cost effective, highly sensitive cw laser power meter with a large dynamic range based on a photodiode. The power meter consists of a photodiode, a current to voltage converter circuit, an offset balancing circuit, a microcontroller, an analog to digital converter, reed relays, and an alphanumeric liquid crystal display. The power meter can record absolute laser power levels as low as 1 pW. The dynamic range measured with a cw laser at a wavelength of 532 nm is 8×1010. The high sensitivity and large dynamic range are achieved by the implementation of an analog background balancing circuit and autoranging.

  4. Highly sensitive bovine serum albumin biosensor based on liquid crystal

    NASA Astrophysics Data System (ADS)

    Sharma, Vikash; Kumar, Ajay; Ganguly, Prasun; Biradar, A. M.

    2014-01-01

    A highly sensitive liquid crystal (LC) based bovine serum albumin (BSA) protein biosensor is designed. A uniform homeotropic alignment of nematic LC was observed in BSA free substrate which changed into homogeneous in presence of BSA. The change in the LC orientation is found to depend strongly on BSA concentration. This change in the LC alignment is attributed to the modification in the surface conditions which is verified by contact angle measurements. We have detected an ultra low concentration (0.5 μg/ml) of BSA. The present study demonstrates the utilization of LC in the realization of high sensitivity biosensors.

  5. Quantification of patulin in fruit leathers by ultra-high-performance liquid chromatography-photodiode array (UPLC-PDA).

    PubMed

    Maragos, Chris M; Busman, Mark; Ma, Liang; Bobell, John

    2015-01-01

    Patulin is a mycotoxin commonly found in certain fruit and fruit products. For this reason many countries have established regulatory limits pertaining to, in particular, apple juice and apple products. Fruit leathers are produced by dehydrating fruit puree, leaving a sweet product that has a leathery texture. A recent report in the literature described the detection of patulin at substantial levels in fruit leathers. To investigate this further, an ultra-high-performance liquid chromatography-photodiode array (UPLC-PDA) method was developed for the sensitive detection of patulin in fruit leathers. Investigations were also made of the suitability of direct analysis in real time-mass spectrometry (DART-MS) for detection of patulin from the surface of fruit leathers. Results indicated DART-MS was insufficiently sensitive for quantification from the surface of home-style apple leathers, although patulin spiked onto the surface of leather or peel could be detected. The UPLC-PDA method was used to determine the fate of patulin during the preparation of home-made fruit leathers. Interestingly, when a home-style process was used, the patulin was not destroyed, but rather increased in concentration as the puree was dehydrated. The UPLC-PDA method was also used to screen for patulin in commercial fruit leathers. Of the 36 products tested, 14 were above the limit of detection (3.5 μg kg(-1)) and nine were above the limit of quantification (12 μg kg(-1)). Positive samples were confirmed by UPLC-MS/MS. Only one sample was found above the US regulatory limit for single-strength apple juice products (50 μg kg(-1)). These results suggest patulin can be concentrated during preparation and can be found in fruit leathers. The limited survey suggests that patulin is fairly prevalent in such commercial products, but that the levels are usually low.

  6. High-sensitivity SQUIDs with dispersive readout for scanning microscopy

    NASA Astrophysics Data System (ADS)

    Mol, J. M.; Foroughi, F.; Arps, J.; Kammerloher, E.; Bethke, P.; Gibson, G. W., Jr.; Fung, Y. K. K.; Klopfer, B.; Nowack, K.; Kratz, P. A.; Huber, M. E.; Moler, K. A.; Kirtley, J. R.; Bluhm, H.

    2014-03-01

    In a scanning SQUID microscope, the high magnetic flux sensitivity is utilized to image magnetic properties of sample surfaces. As an alternative to the widely used DC SQUIDs, we present Nb SQUIDs for scanning with dispersive microwave readout, featuring significantly higher bandwidth and sensitivity. An on-chip shunt capacitor in parallel with the junction and flux pickup loops forms an LC resonator whose resonance depends on the flux in the SQUID. The readout utilizes a phase-sensitive detection of the reflected drive signal at the SQUID's resonance frequency. Highest sensitivities are achieved by making use of the inherent nonlinearity of the device at high excitation powers. We present a study of the characteristics and noise measurements of our sensors at 4 K. Extrapolations from our results to 300 mK indicate that flux sensitivities as low as 50 nΦ0Hz- 1 / 2 could be possible. Using high-resolution lithography, our sensors promise sub-micron spatial resolution. Integrated into a scanning microscope, they will provide a powerful tool for the study of weak magnetic effects and quantum coherent phenomena. This work was supported by NSF IMR-MIP grant No. 0957616 and the Alfried Krupp von Bohlen und Halbach - Foundation.

  7. Large pi-aromatic molecules as potential sensitizers for highly efficient dye-sensitized solar cells.

    PubMed

    Imahori, Hiroshi; Umeyama, Tomokazu; Ito, Seigo

    2009-11-17

    Recently, dye-sensitized solar cells have attracted much attention relevant to global environmental issues. Thus far, ruthenium(II) bipyridyl complexes have proven to be the most efficient TiO(2) sensitizers in dye-sensitized solar cells. However, a gradual increment in the highest power conversion efficiency has been recognized in the past decade. More importantly, considering that ruthenium is a rare metal, novel dyes without metal or using inexpensive metal are desirable for highly efficient dye-sensitized solar cells. Large pi-aromatic molecules, such as porphyrins, phthalocyanines, and perylenes, are important classes of potential sensitizers for highly efficient dye-sensitized solar cells, owing to their photostability and high light-harvesting capabilities that can allow applications in thinner, low-cost dye-sensitized solar cells. Porphyrins possess an intense Soret band at 400 nm and moderate Q bands at 600 nm. Nevertheless, the poor light-harvesting properties relative to the ruthenium complexes have limited the cell performance of porphyrin-sensitized TiO(2) cells. Elongation of the pi conjugation and loss of symmetry in porphyrins cause broadening and a red shift of the absorption bands together with an increasing intensity of the Q bands relative to that of the Soret band. On the basis of the strategy, the cell performance of porphyrin-sensitized solar cells has been improved intensively by the enhanced light absorption. Actually, some push-pull-type porphyrins have disclosed a remarkably high power conversion efficiency (6-7%) that was close to that of the ruthenium complexes. Phthalocyanines exhibit strong absorption around 300 and 700 nm and redox features that are similar to porphyrins. Moreover, phthalocyanines are transparent over a large region of the visible spectrum, thereby enabling the possibility of using them as "photovoltaic windows". However, the cell performance was poor, owing to strong aggregation and lack of directionality in the

  8. High-sensitivity, high-speed continuous imaging system

    DOEpatents

    Watson, Scott A; Bender, III, Howard A

    2014-11-18

    A continuous imaging system for recording low levels of light typically extending over small distances with high-frame rates and with a large number of frames is described. Photodiode pixels disposed in an array having a chosen geometry, each pixel having a dedicated amplifier, analog-to-digital convertor, and memory, provide parallel operation of the system. When combined with a plurality of scintillators responsive to a selected source of radiation, in a scintillator array, the light from each scintillator being directed to a single corresponding photodiode in close proximity or lens-coupled thereto, embodiments of the present imaging system may provide images of x-ray, gamma ray, proton, and neutron sources with high efficiency.

  9. Microelectromechanical Resonant Accelerometer Designed with a High Sensitivity.

    PubMed

    Zhang, Jing; Su, Yan; Shi, Qin; Qiu, An-Ping

    2015-01-01

    This paper describes the design and experimental evaluation of a silicon micro-machined resonant accelerometer (SMRA). This type of accelerometer works on the principle that a proof mass under acceleration applies force to two double-ended tuning fork (DETF) resonators, and the frequency output of two DETFs exhibits a differential shift. The dies of an SMRA are fabricated using silicon-on-insulator (SOI) processing and wafer-level vacuum packaging. This research aims to design a high-sensitivity SMRA because a high sensitivity allows for the acceleration signal to be easily demodulated by frequency counting techniques and decreases the noise level. This study applies the energy-consumed concept and the Nelder-Mead algorithm in the SMRA to address the design issues and further increase its sensitivity. Using this novel method, the sensitivity of the SMRA has been increased by 66.1%, which attributes to both the re-designed DETF and the reduced energy loss on the micro-lever. The results of both the closed-form and finite-element analyses are described and are in agreement with one another. A resonant frequency of approximately 22 kHz, a frequency sensitivity of over 250 Hz per g, a one-hour bias stability of 55 μg, a bias repeatability (1σ) of 48 μg and the bias-instability of 4.8 μg have been achieved. PMID:26633425

  10. Microelectromechanical Resonant Accelerometer Designed with a High Sensitivity

    PubMed Central

    Zhang, Jing; Su, Yan; Shi, Qin; Qiu, An-Ping

    2015-01-01

    This paper describes the design and experimental evaluation of a silicon micro-machined resonant accelerometer (SMRA). This type of accelerometer works on the principle that a proof mass under acceleration applies force to two double-ended tuning fork (DETF) resonators, and the frequency output of two DETFs exhibits a differential shift. The dies of an SMRA are fabricated using silicon-on-insulator (SOI) processing and wafer-level vacuum packaging. This research aims to design a high-sensitivity SMRA because a high sensitivity allows for the acceleration signal to be easily demodulated by frequency counting techniques and decreases the noise level. This study applies the energy-consumed concept and the Nelder-Mead algorithm in the SMRA to address the design issues and further increase its sensitivity. Using this novel method, the sensitivity of the SMRA has been increased by 66.1%, which attributes to both the re-designed DETF and the reduced energy loss on the micro-lever. The results of both the closed-form and finite-element analyses are described and are in agreement with one another. A resonant frequency of approximately 22 kHz, a frequency sensitivity of over 250 Hz per g, a one-hour bias stability of 55 μg, a bias repeatability (1σ) of 48 μg and the bias-instability of 4.8 μg have been achieved. PMID:26633425

  11. Sensitivity of high-frequency Rayleigh-wave data revisited

    USGS Publications Warehouse

    Xia, J.; Miller, R.D.; Ivanov, J.

    2007-01-01

    Rayleigh-wave phase velocity of a layered earth model is a function of frequency and four groups of earth properties: P-wave velocity, S-wave velocity (Vs), density, and thickness of layers. Analysis of the Jacobian matrix (or the difference method) provides a measure of dispersion curve sensitivity to earth properties. Vs is the dominant influence for the fundamental mode (Xia et al., 1999) and higher modes (Xia et al., 2003) of dispersion curves in a high frequency range (>2 Hz) followed by layer thickness. These characteristics are the foundation of determining S-wave velocities by inversion of Rayleigh-wave data. More applications of surface-wave techniques show an anomalous velocity layer such as a high-velocity layer (HVL) or a low-velocity layer (LVL) commonly exists in near-surface materials. Spatial location (depth) of an anomalous layer is usually the most important information that surface-wave techniques are asked to provide. Understanding and correctly defining the sensitivity of high-frequency Rayleigh-wave data due to depth of an anomalous velocity layer are crucial in applying surface-wave techniques to obtain a Vs profile and/or determine the depth of an anomalous layer. Because depth is not a direct earth property of a layered model, changes in depth will result in changes in other properties. Modeling results show that sensitivity at a given depth calculated by the difference method is dependent on the Vs difference (contrast) between an anomalous layer and surrounding layers. The larger the contrast is, the higher the sensitivity due to depth of the layer. Therefore, the Vs contrast is a dominant contributor to sensitivity of Rayleigh-wave data due to depth of an anomalous layer. Modeling results also suggest that the most sensitive depth for an HVL is at about the middle of the depth to the half-space, but for an LVL it is near the ground surface. ?? 2007 Society of Exploration Geophysicists.

  12. NK sensitivity of neuroblastoma cells determined by a highly sensitive coupled luminescent method

    SciTech Connect

    Ogbomo, Henry; Hahn, Anke; Geiler, Janina; Michaelis, Martin; Doerr, Hans Wilhelm; Cinatl, Jindrich . E-mail: Cinatl@em.uni-frankfurt.de

    2006-01-06

    The measurement of natural killer (NK) cells toxicity against tumor or virus-infected cells especially in cases with small blood samples requires highly sensitive methods. Here, a coupled luminescent method (CLM) based on glyceraldehyde-3-phosphate dehydrogenase release from injured target cells was used to evaluate the cytotoxicity of interleukin-2 activated NK cells against neuroblastoma cell lines. In contrast to most other methods, CLM does not require the pretreatment of target cells with labeling substances which could be toxic or radioactive. The effective killing of tumor cells was achieved by low effector/target ratios ranging from 0.5:1 to 4:1. CLM provides highly sensitive, safe, and fast procedure for measurement of NK cell activity with small blood samples such as those obtained from pediatric patients.

  13. Highly Mass-Sensitive Thin Film Plate Acoustic Resonators (FPAR)

    PubMed Central

    Arapan, Lilia; Alexieva, Gergana; Avramov, Ivan D.; Radeva, Ekaterina; Strashilov, Vesseline; Katardjiev, Ilia; Yantchev, Ventsislav

    2011-01-01

    The mass sensitivity of thin aluminum nitride (AlN) film S0 Lamb wave resonators is theoretically and experimentally studied. Theoretical predictions based on modal and finite elements method analysis are experimentally verified. Here, two-port 888 MHz synchronous FPARs are micromachined and subsequently coated with hexamethyl-disiloxane(HMDSO)-plasma-polymerized thin films of various thicknesses. Systematic data on frequency shift and insertion loss versus film thickness are presented. FPARs demonstrate high mass-loading sensitivity as well as good tolerance towards the HMDSO viscous losses. Initial measurements in gas phase environment are further presented. PMID:22163994

  14. Highly mass-sensitive thin film plate acoustic resonators (FPAR).

    PubMed

    Arapan, Lilia; Alexieva, Gergana; Avramov, Ivan D; Radeva, Ekaterina; Strashilov, Vesseline; Katardjiev, Ilia; Yantchev, Ventsislav

    2011-01-01

    The mass sensitivity of thin aluminum nitride (AlN) film S0 Lamb wave resonators is theoretically and experimentally studied. Theoretical predictions based on modal and finite elements method analysis are experimentally verified. Here, two-port 888 MHz synchronous FPARs are micromachined and subsequently coated with hexamethyl-disiloxane(HMDSO)-plasma-polymerized thin films of various thicknesses. Systematic data on frequency shift and insertion loss versus film thickness are presented. FPARs demonstrate high mass-loading sensitivity as well as good tolerance towards the HMDSO viscous losses. Initial measurements in gas phase environment are further presented.

  15. Porous silicon ring resonator for compact, high sensitivity biosensing applications

    DOE PAGES

    Rodriguez, Gilberto A.; Hu, Shuren; Weiss, Sharon M.

    2015-01-01

    A ring resonator is patterned on a porous silicon slab waveguide to produce a compact, high quality factor biosensor with a large internal surface area available for enhanced recognition of biological and chemical molecules. The porous nature of the ring resonator allows molecules to directly interact with the guided mode. Quality factors near 10,000 were measured for porous silicon ring resonators with a radius of 25 μm. A bulk detection sensitivity of 380 nm/RIU was measured upon exposure to salt water solutions. Specific detection of nucleic acid molecules was demonstrated with a surface detection sensitivity of 4 pm/nM.

  16. Integrated compact optical current sensors with high sensitivity

    NASA Astrophysics Data System (ADS)

    Huang, Duanni; Pintus, Paolo; Srinivasan, Sudharsanan; Bowers, John E.

    2016-02-01

    We demonstrate a Sagnac based fiber optic current sensor using only 10cm of terbium doped fiber with a high Verdet constant of 15.5 rad/Tm at a wavelength of 1300nm. Measurements of the fiber inside a solenoid show over 40dB of open loop dynamic range as well as a minimum detectable current of 0.1mA. In order to decrease size while increasing sensitivity even further, we consider integrated magneto-optic waveguides as the sensing element. Using silicon waveguides alongside magneto-optic material such as cerium doped yttrium iron garnet (Ce:YiG), we model the Verdet constant to be as high as 10,000 rad/Tm. This improvement by three orders of magnitude shows potential for magnetooptic waveguides to be used in ultra-high sensitivity optical magnetometers and current sensors. Finally, we propose a fully integrated optical current sensor using heterogeneous integration for silicon photonics.

  17. High-sensitivity linear piezoresistive transduction for nanomechanical beam resonators.

    PubMed

    Sansa, Marc; Fernández-Regúlez, Marta; Llobet, Jordi; San Paulo, Álvaro; Pérez-Murano, Francesc

    2014-01-01

    Highly sensitive conversion of motion into readable electrical signals is a crucial and challenging issue for nanomechanical resonators. Efficient transduction is particularly difficult to realize in devices of low dimensionality, such as beam resonators based on carbon nanotubes or silicon nanowires, where mechanical vibrations combine very high frequencies with miniscule amplitudes. Here we describe an enhanced piezoresistive transduction mechanism based on the asymmetry of the beam shape at rest. We show that this mechanism enables highly sensitive linear detection of the vibration of low-resistivity silicon beams without the need of exceptionally large piezoresistive coefficients. The general application of this effect is demonstrated by detecting multiple-order modes of silicon nanowire resonators made by either top-down or bottom-up fabrication methods. These results reveal a promising approach for practical applications of the simplest mechanical resonators, facilitating its manufacturability by very large-scale integration technologies. PMID:25000256

  18. A novel high-sensitivity FBG pressure sensor

    NASA Astrophysics Data System (ADS)

    Yao, Zhenhua; Fu, Tao; Leng, Jinsong

    2007-07-01

    A novel pressure sensor based on FBG is designed in this paper. Not only in normal environment, also does it accurately work in water and petrol where other conventional sensors can not work normally. In this paper, the principle of the novel sensor is introduced, and two experiments are further performed: One is keeping the sensor flatly in the gastight silo whose pressure is supplied by an air compressing engine, and the other one is keeping the sensor in liquid. The analysis of the result data demonstrates that the sensor possesses high sensitivity, high linearity, high precision and repeatability. Its experimental linearity and sensitivity approach 0.99858 and 5.35×10 -3MPa -1, respectively. It is also discussed using the sensor to measure the volume in tank.

  19. High-sensitivity linear piezoresistive transduction for nanomechanical beam resonators.

    PubMed

    Sansa, Marc; Fernández-Regúlez, Marta; Llobet, Jordi; San Paulo, Álvaro; Pérez-Murano, Francesc

    2014-01-01

    Highly sensitive conversion of motion into readable electrical signals is a crucial and challenging issue for nanomechanical resonators. Efficient transduction is particularly difficult to realize in devices of low dimensionality, such as beam resonators based on carbon nanotubes or silicon nanowires, where mechanical vibrations combine very high frequencies with miniscule amplitudes. Here we describe an enhanced piezoresistive transduction mechanism based on the asymmetry of the beam shape at rest. We show that this mechanism enables highly sensitive linear detection of the vibration of low-resistivity silicon beams without the need of exceptionally large piezoresistive coefficients. The general application of this effect is demonstrated by detecting multiple-order modes of silicon nanowire resonators made by either top-down or bottom-up fabrication methods. These results reveal a promising approach for practical applications of the simplest mechanical resonators, facilitating its manufacturability by very large-scale integration technologies.

  20. Sensitivity of HAWC to high-mass dark matter annihilations

    NASA Astrophysics Data System (ADS)

    Abeysekara, A. U.; Alfaro, R.; Alvarez, C.; Álvarez, J. D.; Arceo, R.; Arteaga-Velázquez, J. C.; Ayala Solares, H. A.; Barber, A. S.; Baughman, B. M.; Bautista-Elivar, N.; Becerra Gonzalez, J.; Belmont, E.; BenZvi, S. Y.; Berley, D.; Bonilla Rosales, M.; Braun, J.; Caballero-Lopez, R. A.; Caballero-Mora, K. S.; Carramiñana, A.; Castillo, M.; Cotti, U.; Cotzomi, J.; de la Fuente, E.; De León, C.; DeYoung, T.; Diaz Hernandez, R.; Diaz-Cruz, L.; Díaz-Vélez, J. C.; Dingus, B. L.; DuVernois, M. A.; Ellsworth, R. W.; Fiorino, D. W.; Fraija, N.; Galindo, A.; Garfias, F.; González, M. M.; Goodman, J. A.; Grabski, V.; Gussert, M.; Hampel-Arias, Z.; Harding, J. P.; Hui, C. M.; Hüntemeyer, P.; Imran, A.; Iriarte, A.; Karn, P.; Kieda, D.; Kunde, G. J.; Lara, A.; Lauer, R. J.; Lee, W. H.; Lennarz, D.; León Vargas, H.; Linares, E. C.; Linnemann, J. T.; Longo, M.; Luna-Garcia, R.; Marinelli, A.; Martinez, H.; Martinez, O.; Martínez-Castro, J.; Matthews, J. A. J.; McEnery, J.; Mendoza Torres, E.; Miranda-Romagnoli, P.; Moreno, E.; Mostafá, M.; Nellen, L.; Newbold, M.; Noriega-Papaqui, R.; Oceguera-Becerra, T.; Patricelli, B.; Pelayo, R.; Pérez-Pérez, E. G.; Pretz, J.; Rivière, C.; Rosa-González, D.; Ryan, J.; Salazar, H.; Salesa, F.; Sanchez, F. E.; Sandoval, A.; Schneider, M.; Silich, S.; Sinnis, G.; Smith, A. J.; Sparks Woodle, K.; Springer, R. W.; Taboada, I.; Toale, P. A.; Tollefson, K.; Torres, I.; Ukwatta, T. N.; Villaseñor, L.; Weisgarber, T.; Westerhoff, S.; Wisher, I. G.; Wood, J.; Yodh, G. B.; Younk, P. W.; Zaborov, D.; Zepeda, A.; Zhou, H.; Abazajian, K. N.; Milagro Collaboration

    2014-12-01

    The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view detector sensitive to gamma rays of 100 GeV to a few hundred TeV. Located in central Mexico at 19° North latitude and 4100 m above sea level, HAWC will observe gamma rays and cosmic rays with an array of water Cherenkov detectors. The full HAWC array is scheduled to be operational in Spring 2015. In this paper, we study the HAWC sensitivity to the gamma-ray signatures of high-mass (multi-TeV) dark matter annihilation. The HAWC observatory will be sensitive to diverse searches for dark matter annihilation, including annihilation from extended dark matter sources, the diffuse gamma-ray emission from dark matter annihilation, and gamma-ray emission from nonluminous dark matter subhalos. Here we consider the HAWC sensitivity to a subset of these sources, including dwarf galaxies, the M31 galaxy, the Virgo cluster, and the Galactic center. We simulate the HAWC response to gamma rays from these sources in several well-motivated dark matter annihilation channels. If no gamma-ray excess is observed, we show the limits HAWC can place on the dark matter cross section from these sources. In particular, in the case of dark matter annihilation into gauge bosons, HAWC will be able to detect a narrow range of dark matter masses to cross sections below thermal. HAWC should also be sensitive to nonthermal cross sections for masses up to nearly 1000 TeV. The constraints placed by HAWC on the dark matter cross section from known sources should be competitive with current limits in the mass range where HAWC has similar sensitivity. HAWC can additionally explore higher dark matter masses than are currently constrained.

  1. Crocodylus niloticus (Crocodilia) is highly sensitive to water surface waves.

    PubMed

    Grap, Nadja J; Monzel, Anna S; Kohl, Tobias; Bleckmann, Horst

    2015-10-01

    Crocodiles show oriented responses to water surface wave stimuli but up to now behavioral thresholds are missing. This study determines the behavioral thresholds of crocodilians to water surface waves. Nile crocodiles (Crocodylus niloticus) were conditioned to respond to single-frequency water surface wave stimuli (duration 1150 ms, frequency 15, 30, 40, 60 and 80 Hz), produced by blowing air onto the water surface. Our study shows that C. niloticus is highly sensitive to capillary water surface waves. Threshold values decreased with increasing frequency and ranged between 10.3 μm (15 Hz) and 0.5 μm (80 Hz) peak-to-peak wave amplitude. For the frequencies 15 Hz and 30 Hz the sensitivity of one spectacled caiman (Caiman crocodilus) to water surface waves was also tested. Threshold values were 12.8 μm (15 Hz) down to 1.76 μm (30 Hz), i.e. close to the threshold values of C. niloticus. The surface wave sensitivity of crocodiles is similar to the surface wave sensitivity of semi-aquatic insects and fishing spiders but does not match the sensitivity of surface-feeding fishes which is higher by one to two orders of magnitude.

  2. Crocodylus niloticus (Crocodilia) is highly sensitive to water surface waves.

    PubMed

    Grap, Nadja J; Monzel, Anna S; Kohl, Tobias; Bleckmann, Horst

    2015-10-01

    Crocodiles show oriented responses to water surface wave stimuli but up to now behavioral thresholds are missing. This study determines the behavioral thresholds of crocodilians to water surface waves. Nile crocodiles (Crocodylus niloticus) were conditioned to respond to single-frequency water surface wave stimuli (duration 1150 ms, frequency 15, 30, 40, 60 and 80 Hz), produced by blowing air onto the water surface. Our study shows that C. niloticus is highly sensitive to capillary water surface waves. Threshold values decreased with increasing frequency and ranged between 10.3 μm (15 Hz) and 0.5 μm (80 Hz) peak-to-peak wave amplitude. For the frequencies 15 Hz and 30 Hz the sensitivity of one spectacled caiman (Caiman crocodilus) to water surface waves was also tested. Threshold values were 12.8 μm (15 Hz) down to 1.76 μm (30 Hz), i.e. close to the threshold values of C. niloticus. The surface wave sensitivity of crocodiles is similar to the surface wave sensitivity of semi-aquatic insects and fishing spiders but does not match the sensitivity of surface-feeding fishes which is higher by one to two orders of magnitude. PMID:26153334

  3. High-throughput LC-MS/MS based simultaneous determination of polyamines including N-acetylated forms in human saliva and the diagnostic approach to breast cancer patients.

    PubMed

    Tsutsui, Haruhito; Mochizuki, Toshiki; Inoue, Koichi; Toyama, Tatsuya; Yoshimoto, Nobuyasu; Endo, Yumi; Todoroki, Kenichiro; Min, Jun Zhe; Toyo'oka, Toshimasa

    2013-12-17

    The determination of polyamines and their N-acetylated forms was performed by ultraperformance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS). The polyamines efficiently reacted with 4-(N,N-dimethylaminosulfonyl)-7-fluoro-2,1,3-benzoxadiazole (DBD-F) in 0.1 M borax (pH 9.3) at 60 °C for 30 min. The resulting derivatives were analyzed by electrospray ionization (ESI)-MS and sensitively detected by selected reaction monitoring (SRM). Furthermore, a rapid separation of the polyamine derivatives within 10 min was performed by UPLC using an antipressurized column packed with 1.7-μm octadecylsilyl (ODS) silica gel. The limits of detection (S/N = 3) on the SRM chromatograms were at the attomole level (9-43 amol). This procedure was used to successfully determine 11 polyamines, including their N-acetylated forms, in the saliva of patients with primary and relapsed breast cancer and healthy volunteers. The level of several polyamines (Ac-PUT, Ac-SPD, Ac-SPM, DAc-SPD, and DAc-SPM) increases in breast cancer patients. Furthermore, the levels of three polyamines (Ac-SPM, DAc-SPD, and DAc-SPM) were significantly higher only in the relapsed patients. The present method proved highly sensitive and is characterized by specificity and feasibility for sample analysis. Consequently, the proposed method is useful for the noninvasive salivary diagnosis of cancer patients and could be applied to determine polyamines in several specimens of biological nature. PMID:24274257

  4. NETD test of high-sensitivity infrared camera

    NASA Astrophysics Data System (ADS)

    Li, Yingwen; Pan, Debin; Yang, Changcheng; Luo, Yan

    2007-12-01

    Infrared camera has more and more application in military, judicature, rescue, industry, hospital and science. Nowadays the NETD (Noise Equivalent Temperature Difference) of high-sensitivity cooled infrared camera is less than 10 mK. If we test the NETD from the analog video output port of infrared camera using 8-bit and 10-bit ADC frame grabber, the NETD accuracy is 7.81 mK and 2.76 mK which correspond to relative error 78.7% and 27.6% for a 10 mK NETD infrared camera. Such kind of accuracy is obviously not proper for the performance evaluation of high-sensitivity infrared camera with NETD less than 10 mK. The NETD test accuracy can be improved by increasing the effective bit number of the ADC of frame grabber. The quantization error of ADC of frame grabber has become the main factor which contributes most to the NETD error of the high-sensitivity infrared camera. It is difficult to evaluate the electrooptical performance of the high-sensitivity infrared camera through its analog video. Although the NETD test accuracy can be improved by reducing the linear temperature range or increasing the effective bits of the ADC of frame grabber under analog video interface test condition, it is difficult to meet the test needs. But under the 14 bits digital video interface test condition and 1 K linear range, the NETD test accuracy of 0.24 mK can be achieved. The NETD accuracy can be also improved by reducing the linear temperature range. The NETD test accuracy can be 0.488 mK through 14-bit digital video under 2 K linear temperature range and its relative error equals 4.9% for a 10 mK NETD high-sensitivity infrared camera which meets the requirement. The test result through the digital video port of an infrared camera shows that the test result through digital video port matches with its nominal value. This necessitates the need of digital video interface of high-sensitivity infrared camera in NETD test in order to evaluate its performance accuracy.

  5. High-sensitivity three-mode optomechanical transducer

    SciTech Connect

    Zhao, C.; Fang, Q.; Susmithan, S.; Miao, H.; Ju, L.; Fan, Y.; Blair, D.; Hosken, D. J.; Munch, J.; Veitch, P. J.; Slagmolen, B. J. J.

    2011-12-15

    Three-mode optomechanical interactions have been predicted to allow the creation of very high sensitivity transducers in which very strong optical self-cooling and strong optomechanical quantum entanglement are predicted. Strong coupling is achieved by engineering a transducer in which both the pump laser and a single signal sideband frequency are resonantly enhanced. Here we demonstrate that very high sensitivity can be achieved in a very simple system consisting of a Fabry-Perot cavity with CO{sub 2} laser thermal tuning. We demonstrate a displacement sensitivity of {approx}1x10{sup -17} m/{radical}(Hz), which is sufficient to observe a thermally excited acoustic mode in a 5.6 kg sapphire mirror with a signal-to-noise ratio of more than 20 dB. It is shown that a measurement sensitivity of {approx}2x10{sup -20} m/{radical}(Hz) limited by the quantum shot noise is achievable with optimization of the cavity parameters.

  6. Compact Tb doped fiber optic current sensor with high sensitivity.

    PubMed

    Huang, Duanni; Srinivasan, Sudharsanan; Bowers, John E

    2015-11-16

    A highly sensitive fiber optic current sensor using terbium doped fiber is presented. The Verdet constant of the terbium doped fiber at 1300nm is found to be 19.5μrad/A using both a polarimetric and interferometric type sensor. Measurements on a Sagnac-loop sensor using 10cm of terbium doped fiber placed inside a solenoid show over 40dB of open loop dynamic range as well as a minimum detectable current of 0.1mA. Extrapolations of our measurements show that in a practical setup with Tb fiber wrapped around a current carrying wire, the optimal configuration is a 0.5m piece of Tb fiber with a noise limit of 22mA/√Hz. This sensor is promising for current sensing applications that require high sensitivity and small size, weight, and power. PMID:26698480

  7. High-sensitivity acoustic sensors from nanofibre webs

    NASA Astrophysics Data System (ADS)

    Lang, Chenhong; Fang, Jian; Shao, Hao; Ding, Xin; Lin, Tong

    2016-03-01

    Considerable interest has been devoted to converting mechanical energy into electricity using polymer nanofibres. In particular, piezoelectric nanofibres produced by electrospinning have shown remarkable mechanical energy-to-electricity conversion ability. However, there is little data for the acoustic-to-electric conversion of electrospun nanofibres. Here we show that electrospun piezoelectric nanofibre webs have a strong acoustic-to-electric conversion ability. Using poly(vinylidene fluoride) as a model polymer and a sensor device that transfers sound directly to the nanofibre layer, we show that the sensor devices can detect low-frequency sound with a sensitivity as high as 266 mV Pa-1. They can precisely distinguish sound waves in low to middle frequency region. These features make them especially suitable for noise detection. Our nanofibre device has more than five times higher sensitivity than a commercial piezoelectric poly(vinylidene fluoride) film device. Electrospun piezoelectric nanofibres may be useful for developing high-performance acoustic sensors.

  8. Quantum-Dot-Sensitized Solar Cell with Unprecedentedly High Photocurrent

    PubMed Central

    Lee, Jin-Wook; Son, Dae-Yong; Ahn, Tae Kyu; Shin, Hee-Won; Kim, In Young; Hwang, Seong-Ju; Ko, Min Jae; Sul, Soohwan; Han, Hyouksoo; Park, Nam-Gyu

    2013-01-01

    The reported photocurrent density (JSC) of PbS quantum dot (QD)-sensitized solar cell was less than 19 mA/cm2 despite the capability to generate 38 mA/cm2, which results from inefficient electron injection and fast charge recombination. Here, we report on a PbS:Hg QD-sensitized solar cell with an unprecedentedly high JSC of 30 mA/cm2. By Hg2+ doping into PbS, JSC is almost doubled with improved stability. Femtosecond transient study confirms that the improved JSC is due to enhanced electron injection and suppressed charge recombination. EXAFS reveals that Pb-S bond is reinforced and structural disorder is reduced by interstitially incorporated Hg2+, which is responsible for the enhanced electron injection, suppressed recombination and stability. Thanks to the extremely high JSC, power conversion efficiency of 5.6% is demonstrated at one sun illumination. PMID:23308343

  9. Development of High Sensitivity Nuclear Emulsion and Fine Grained Emulsion

    NASA Astrophysics Data System (ADS)

    Kawahara, H.; Asada, T.; Naka, T.; Naganawa, N.; Kuwabara, K.; Nakamura, M.

    2014-08-01

    Nuclear emulsion is a particle detector having high spacial resolution and angular resolution. It became useful for large statistics experiment thanks to the development of automatic scanning system. In 2010, a facility for emulsion production was introduced and R&D of nuclear emulsion began at Nagoya university. In this paper, we present results of development of the high sensitivity emulsion and fine grained emulsion for dark matter search experiment. Improvement of sensitivity is achieved by raising density of silver halide crystals and doping well-adjusted amount of chemicals. Production of fine grained emulsion was difficult because of unexpected crystal condensation. By mixing polyvinyl alcohol (PVA) to gelatin as a binder, we succeeded in making a stable fine grained emulsion.

  10. Horizontal film balance having wide range and high sensitivity

    DOEpatents

    Abraham, B.M.; Miyano, K.; Ketterson, J.B.

    1981-03-05

    A thin-film, horizontal balance instrument is provided for measuring surface tension (surface energy) of thin films suspended on a liquid substrate. The balance includes a support bearing and an optical feedback arrangement for wide-range, high sensitivity measurements. The force on the instrument is balanced by an electromagnet, the current through the magnet providing a measure of the force applied to the instrument. A novel float construction is also disclosed.

  11. Sensitivity to Envelope Interaural Time Differences at High Modulation Rates

    PubMed Central

    Bleeck, Stefan; McAlpine, David

    2015-01-01

    Sensitivity to interaural time differences (ITDs) conveyed in the temporal fine structure of low-frequency tones and the modulated envelopes of high-frequency sounds are considered comparable, particularly for envelopes shaped to transmit similar fidelity of temporal information normally present for low-frequency sounds. Nevertheless, discrimination performance for envelope modulation rates above a few hundred Hertz is reported to be poor—to the point of discrimination thresholds being unattainable—compared with the much higher (>1,000 Hz) limit for low-frequency ITD sensitivity, suggesting the presence of a low-pass filter in the envelope domain. Further, performance for identical modulation rates appears to decline with increasing carrier frequency, supporting the view that the low-pass characteristics observed for envelope ITD processing is carrier-frequency dependent. Here, we assessed listeners’ sensitivity to ITDs conveyed in pure tones and in the modulated envelopes of high-frequency tones. ITD discrimination for the modulated high-frequency tones was measured as a function of both modulation rate and carrier frequency. Some well-trained listeners appear able to discriminate ITDs extremely well, even at modulation rates well beyond 500 Hz, for 4-kHz carriers. For one listener, thresholds were even obtained for a modulation rate of 800 Hz. The highest modulation rate for which thresholds could be obtained declined with increasing carrier frequency for all listeners. At 10 kHz, the highest modulation rate at which thresholds could be obtained was 600 Hz. The upper limit of sensitivity to ITDs conveyed in the envelope of high-frequency modulated sounds appears to be higher than previously considered. PMID:26721926

  12. Sensitivity to Envelope Interaural Time Differences at High Modulation Rates.

    PubMed

    Monaghan, Jessica J M; Bleeck, Stefan; McAlpine, David

    2015-01-01

    Sensitivity to interaural time differences (ITDs) conveyed in the temporal fine structure of low-frequency tones and the modulated envelopes of high-frequency sounds are considered comparable, particularly for envelopes shaped to transmit similar fidelity of temporal information normally present for low-frequency sounds. Nevertheless, discrimination performance for envelope modulation rates above a few hundred Hertz is reported to be poor-to the point of discrimination thresholds being unattainable-compared with the much higher (>1,000 Hz) limit for low-frequency ITD sensitivity, suggesting the presence of a low-pass filter in the envelope domain. Further, performance for identical modulation rates appears to decline with increasing carrier frequency, supporting the view that the low-pass characteristics observed for envelope ITD processing is carrier-frequency dependent. Here, we assessed listeners' sensitivity to ITDs conveyed in pure tones and in the modulated envelopes of high-frequency tones. ITD discrimination for the modulated high-frequency tones was measured as a function of both modulation rate and carrier frequency. Some well-trained listeners appear able to discriminate ITDs extremely well, even at modulation rates well beyond 500 Hz, for 4-kHz carriers. For one listener, thresholds were even obtained for a modulation rate of 800 Hz. The highest modulation rate for which thresholds could be obtained declined with increasing carrier frequency for all listeners. At 10 kHz, the highest modulation rate at which thresholds could be obtained was 600 Hz. The upper limit of sensitivity to ITDs conveyed in the envelope of high-frequency modulated sounds appears to be higher than previously considered. PMID:26721926

  13. Horizontal film balance having wide range and high sensitivity

    DOEpatents

    Abraham, Bernard M.; Miyano, Kenjiro; Ketterson, John B.

    1983-01-01

    A thin-film, horizontal balance instrument is provided for measuring surface tension (surface energy) of thin films suspended on a liquid substrate. The balance includes a support bearing and an optical feedback arrangement for wide-range, high sensitivity measurements. The force on the instrument is balanced by an electromagnet, the current through the magnet providing a measure of the force applied to the instrument. A novel float construction is also disclosed.

  14. Horizontal film balance having wide range and high sensitivity

    DOEpatents

    Abraham, B.M.; Miyano, K.; Ketterson, J.B.

    1983-11-08

    A thin-film, horizontal balance instrument is provided for measuring surface tension (surface energy) of thin films suspended on a liquid substrate. The balance includes a support bearing and an optical feedback arrangement for wide-range, high sensitivity measurements. The force on the instrument is balanced by an electromagnet, the current through the magnet providing a measure of the force applied to the instrument. A novel float construction is also disclosed. 5 figs.

  15. Structural Glycomic Analyses at High Sensitivity: A Decade of Progress

    PubMed Central

    Alley, William R.; Novotny, Milos V.

    2014-01-01

    The field of glycomics has recently advanced in response to the urgent need for structural characterization and quantification of complex carbohydrates in biologically and medically important applications. The recent success of analytical glycobiology at high sensitivity reflects numerous advances in biomolecular mass spectrometry and its instrumentation, capillary and microchip separation techniques, and microchemical manipulations of carbohydrate reactivity. The multimethodological approach appears to be necessary to gain an in-depth understanding of very complex glycomes in different biological systems. PMID:23560930

  16. High efficiency neutron sensitive amorphous silicon pixel detectors

    SciTech Connect

    Mireshghi, A.; Cho, G.; Drewery, J.S.; Hong, W.S.; Jing, T.; Lee, H.; Kaplan, S.N.; Perez-Mendez, V.

    1993-11-01

    A multi-layer a-Si:H based thermal neutron detector was designed, fabricated and simulated by Monte Carlo method. The detector consists of two PECVD deposited a-Si:H pin detectors interfaced with coated layers of Gd, as a thermal neutron converter. Simulation results indicate that a detector consisting of 2 Gd films with thicknesses of 2 and 4 {mu}m, sandwiched properly with two layers of sufficiently thick ({approximately}30{mu}m) amorphous silicon diodes, has the optimum parameters. The detectors have an intrinsic efficiency of about 42% at a threshold setting of 7000 electrons, with an expected average signal size of {approximately}12000 electrons which is well above the noise. This efficiency will be further increased to nearly 63%, if we use Gd with 50% enrichment in {sup 157}Gd. We can fabricate position sensitive detectors with spatial resolution of 300 {mu}m with gamma sensitivity of {approximately}1 {times} 10{sup {minus}5}. These detectors are highly radiation resistant and are good candidates for use in various application, where high efficiency, high resolution, gamma insensitive position sensitive neutron detectors are needed.

  17. A novel high-sensitivity electrostatic biased electric field sensor

    NASA Astrophysics Data System (ADS)

    Huang, Jing'ao; Wu, Xiaoming; Wang, Xiaohong; Yan, Xiaojun; Lin, Liwei

    2015-09-01

    In this paper, an electric field sensor (EFS) with high sensitivity is proposed for low-frequency weak-strength ac electric field (E-field) measurements. The EFS is based on a piezoelectric cantilever biased by a strong electrostatic field. The electrostatic bias can enhance the electric field force of a weak ac E-field, thus the cantilever can oscillate in a weak ac E-field and the device sensitivity improves. Theoretical analyses have been established and suggest that a stronger strength of electrostatic field bias would produce a higher sensitivity improvement. In the experiment, a demonstrated sensor consisting of a polyvinylidene fluoride (PVDF) piezoelectric cantilever and a polytetrafluoroethylene (PTFE) electret was built and tested. Instead of extra voltage sources, the PTFE electret was charged to provide the electrostatic field, allowing the EFS a low energy consumption and a simple electric circuit design. The experiment results show good agreement with the simulation. The sensitivity of the cantilever E-field sensor reached 0.84 mV (kV/m)-1 when the surface potential of the electret was  -770 V.

  18. High sensitive volumetric imaging of renal microcirculation in vivo using ultrahigh sensitive optical microangiography

    NASA Astrophysics Data System (ADS)

    Zhi, Zhongwei; Jung, Yeongri; Jia, Yali; An, Lin; Wang, Ruikang K.

    2011-03-01

    We present a non-invasive, label-free imaging technique called Ultrahigh Sensitive Optical Microangiography (UHSOMAG) for high sensitive volumetric imaging of renal microcirculation. The UHS-OMAG imaging system is based on spectral domain optical coherence tomography (SD-OCT), which uses a 47000 A-line scan rate CCD camera to perform an imaging speed of 150 frames per second that takes only ~7 seconds to acquire a 3D image. The technique, capable of measuring slow blood flow down to 4 um/s, is sensitive enough to image capillary networks, such as peritubular capillaries and glomerulus within renal cortex. We show superior performance of UHS-OMAG in providing depthresolved volumetric images of rich renal microcirculation. We monitored the dynamics of renal microvasculature during renal ischemia and reperfusion. Obvious reduction of renal microvascular density due to renal ischemia was visualized and quantitatively analyzed. This technique can be helpful for the assessment of chronic kidney disease (CKD) which relates to abnormal microvasculature.

  19. Development of a highly sensitive galvanic cell oxygen sensor.

    PubMed

    Ogino, H; Asakura, K

    1995-02-01

    A highly sensitive galvanic cell oxygen sensor was successfully developed for determining parts per billion of oxygen in high purity gases such as nitrogen, argon, etc. The response of this improved sensor was proportional in the range of oxygen concentrations from 10.0 ppm to the detection limit. The response speed in this study was improved to within 90 sec for a 90% response. The detection limit was tentatively found to be less than 0.4 ppb corresponding to S N = 2 .

  20. High-sensitivity strain visualization using electroluminescence technologies

    NASA Astrophysics Data System (ADS)

    Xu, Jian; Jo, Hongki

    2016-04-01

    Visualizing mechanical strain/stress changes is an emerging area in structural health monitoring. Several ways are available for strain change visualization through the color/brightness change of the materials subjected to the mechanical stresses, for example, using mechanoluminescence (ML) materials and mechanoresponsive polymers (MRP). However, these approaches were not effectively applicable for civil engineering system yet, due to insufficient sensitivity to low-level strain of typical civil structures and limitation in measuring both static and dynamic strain. In this study, design and validation for high-sensitivity strain visualization using electroluminescence technologies are presented. A high-sensitivity Wheatstone bridge, of which bridge balance is precisely controllable circuits, is used with a gain-adjustable amplifier. The monochrome electroluminescence (EL) technology is employed to convert both static and dynamic strain change into brightness/color change of the EL materials, through either brightness change mode (BCM) or color alternation mode (CAM). A prototype has been made and calibrated in lab, the linearity between strain and brightness change has been investigated.

  1. High sensitivity, homogeneous particle-based immunoassay for thyrotropin (Multipact).

    PubMed

    Wilkins, T A; Brouwers, G; Mareschal, J C; Cambiaso, C L

    1988-09-01

    We describe the first homogeneous, nonradioactive, high-sensitivity assay for human thyrotropin (TSH). The assay is based on particle immunoassay techniques, wherein 800-nm particles form the basis for the immunochemistry, delivery, and the detection technologies, respectively. Our assay also is the first to involve the use of fragmented monoclonal antibodies (to eliminate serum interferences) covalently coupled to particles without loss of their binding properties. Assays are performed in a semiautomated mode with use of a new modular system (Multipact). Equilibrium is reached in less than 2 h. Precision profile, sensitivity, and clinical studies indicate that the assay is accurate, has good precision at low concentrations, and that detection-limit characteristics compare well with those of a leading commercial high-sensitivity immunoradiometric assay (IRMA) for TSH. Dilution characteristics were satisfactory down to the assay's detection limit for a range of clinical samples. Correlation studies vs a reference IRMA method yielded the regression equation, present method = 0.976 (IRMA) + 0.002 milli-int. unit/L (r = 0.98), for 223 samples with TSH concentrations in the range 0 to 30 milli-int. units/L. For 40 samples with TSH less than or equal to 1.0 milli-int. unit/L it was: present method = 0.94 (IRMA) + 0.005 milli-int. unit/L (r = 0.96). PMID:3416423

  2. Highly Sensitive Measurements of 222Rn Diffusion and Emanation

    SciTech Connect

    Zuzel, Grzegorz

    2005-09-08

    Highly sensitive techniques for determination of the 222Rn emanation from solids and diffusion through different membranes are presented. 222Rn and its daughters are measured via the alpha decays in special proportional counters at the absolute sensitivity of {approx}30 {mu}Bq. Radon diffusion can be measured at the level of {approx}10-13 cm2/s. Several samples were examined, e.g. stainless steel, teflon, various gaskets (emanation and diffusion measurements) and tanks. A combination of measurements of the 222Rn diffusion and emanation of thin nylon foils (used in the Borexino experiment) allowed the determination of 226Ra in the materials of interest at the level of {approx}10-12 g/g 238U-equivalent.

  3. Polymer-Particle Pressure-Sensitive Paint with High Photostability.

    PubMed

    Matsuda, Yu; Uchida, Kenta; Egami, Yasuhiro; Yamaguchi, Hiroki; Niimi, Tomohide

    2016-04-16

    We propose a novel fast-responding and paintable pressure-sensitive paint (PSP) based on polymer particles, i.e. polymer-particle (pp-)PSP. As a fast-responding PSP, polymer-ceramic (PC-)PSP is widely studied. Since PC-PSP generally consists of titanium (IV) oxide (TiO₂) particles, a large reduction in the luminescent intensity will occur due to the photocatalytic action of TiO₂. We propose the usage of polymer particles instead of TiO₂ particles to prevent the reduction in the luminescent intensity. Here, we fabricate pp-PSP based on the polystyrene particle with a diameter of 1 μm, and investigate the pressure- and temperature-sensitives, the response time, and the photostability. The performances of pp-PSP are compared with those of PC-PSP, indicating the high photostability with the other characteristics comparable to PC-PSP.

  4. Sensitivity to Error Fields in NSTX High Beta Plasmas

    SciTech Connect

    Park, Jong-Kyu; Menard, Jonathan E.; Gerhardt, Stefan P.; Buttery, Richard J.; Sabbagh, Steve A.; Bell, Steve E.; LeBlanc, Benoit P.

    2011-11-07

    It was found that error field threshold decreases for high β in NSTX, although the density correlation in conventional threshold scaling implies the threshold would increase since higher β plasmas in our study have higher plasma density. This greater sensitivity to error field in higher β plasmas is due to error field amplification by plasmas. When the effect of amplification is included with ideal plasma response calculations, the conventional density correlation can be restored and threshold scaling becomes more consistent with low β plasmas. However, it was also found that the threshold can be significantly changed depending on plasma rotation. When plasma rotation was reduced by non-resonant magnetic braking, the further increase of sensitivity to error field was observed.

  5. High derivatives for fast sensitivity analysis in linear magnetodynamics

    SciTech Connect

    Petin, P. |; Coulomb, J.L.; Conraux, P.

    1997-03-01

    In this article, the authors present a method of sensitivity analysis using high derivatives and Taylor development. The principle is to find a polynomial approximation of the finite elements solution towards the sensitivity parameters. While presenting the method, they explain why this method is applicable with special parameters only. They applied it on a magnetodynamic problem, simple enough to be able to find the analytical solution with a formal calculus tool. They then present the implementation and the good results obtained with the polynomial, first by comparing the derivatives themselves, then by comparing the approximate solution with the theoretical one. After this validation, the authors present results on a real 2D application and they underline the possibilities of reuse in other fields of physics.

  6. Polymer-Particle Pressure-Sensitive Paint with High Photostability

    PubMed Central

    Matsuda, Yu; Uchida, Kenta; Egami, Yasuhiro; Yamaguchi, Hiroki; Niimi, Tomohide

    2016-01-01

    We propose a novel fast-responding and paintable pressure-sensitive paint (PSP) based on polymer particles, i.e. polymer-particle (pp-)PSP. As a fast-responding PSP, polymer-ceramic (PC-)PSP is widely studied. Since PC-PSP generally consists of titanium (IV) oxide (TiO2) particles, a large reduction in the luminescent intensity will occur due to the photocatalytic action of TiO2. We propose the usage of polymer particles instead of TiO2 particles to prevent the reduction in the luminescent intensity. Here, we fabricate pp-PSP based on the polystyrene particle with a diameter of 1 μm, and investigate the pressure- and temperature-sensitives, the response time, and the photostability. The performances of pp-PSP are compared with those of PC-PSP, indicating the high photostability with the other characteristics comparable to PC-PSP. PMID:27092511

  7. A CMOS In-Pixel CTIA High Sensitivity Fluorescence Imager

    PubMed Central

    Murari, Kartikeya; Etienne-Cummings, Ralph; Thakor, Nitish; Cauwenberghs, Gert

    2012-01-01

    Traditionally, charge coupled device (CCD) based image sensors have held sway over the field of biomedical imaging. Complementary metal oxide semiconductor (CMOS) based imagers so far lack sensitivity leading to poor low-light imaging. Certain applications including our work on animal-mountable systems for imaging in awake and unrestrained rodents require the high sensitivity and image quality of CCDs and the low power consumption, flexibility and compactness of CMOS imagers. We present a 132×124 high sensitivity imager array with a 20.1 μm pixel pitch fabricated in a standard 0.5 μ CMOS process. The chip incorporates n-well/p-sub photodiodes, capacitive transimpedance amplifier (CTIA) based in-pixel amplification, pixel scanners and delta differencing circuits. The 5-transistor all-nMOS pixel interfaces with peripheral pMOS transistors for column-parallel CTIA. At 70 fps, the array has a minimum detectable signal of 4 nW/cm2 at a wavelength of 450 nm while consuming 718 μA from a 3.3 V supply. Peak signal to noise ratio (SNR) was 44 dB at an incident intensity of 1 μW/cm2. Implementing 4×4 binning allowed the frame rate to be increased to 675 fps. Alternately, sensitivity could be increased to detect about 0.8 nW/cm2 while maintaining 70 fps. The chip was used to image single cell fluorescence at 28 fps with an average SNR of 32 dB. For comparison, a cooled CCD camera imaged the same cell at 20 fps with an average SNR of 33.2 dB under the same illumination while consuming over a watt. PMID:23136624

  8. High Sensitivity MEMS Strain Sensor: Design and Simulation

    PubMed Central

    Mohammed, Ahmed A. S.; Moussa, Walied A.; Lou, Edmond

    2008-01-01

    In this article, we report on the new design of a miniaturized strain microsensor. The proposed sensor utilizes the piezoresistive properties of doped single crystal silicon. Employing the Micro Electro Mechanical Systems (MEMS) technology, high sensor sensitivities and resolutions have been achieved. The current sensor design employs different levels of signal amplifications. These amplifications include geometric, material and electronic levels. The sensor and the electronic circuits can be integrated on a single chip, and packaged as a small functional unit. The sensor converts input strain to resistance change, which can be transformed to bridge imbalance voltage. An analog output that demonstrates high sensitivity (0.03mV/με), high absolute resolution (1με) and low power consumption (100μA) with a maximum range of ±4000με has been reported. These performance characteristics have been achieved with high signal stability over a wide temperature range (±50°C), which introduces the proposed MEMS strain sensor as a strong candidate for wireless strain sensing applications under harsh environmental conditions. Moreover, this sensor has been designed, verified and can be easily modified to measure other values such as force, torque…etc. In this work, the sensor design is achieved using Finite Element Method (FEM) with the application of the piezoresistivity theory. This design process and the microfabrication process flow to prototype the design have been presented.

  9. High-sensitivity uncooled microcantilever infrared imaging arrays

    NASA Astrophysics Data System (ADS)

    Hunter, Scott R.; Maurer, Gregory; Jiang, Lijun; Simelgor, Gregory

    2006-05-01

    The design and operation of an advanced bimorph microcantilever based infrared imaging detector are presented. This technology has the potential to achieve very high sensitivities due to its inherent high responsivity and low noise sensor and detection electronics. The sensor array is composed of bimaterial, thermally sensitive microcantilever structures that are the moving elements of variable plate capacitors. The heat sensing microcantilever structures are integrated with CMOS control and amplification electronics to produce a low cost imager that is compatible with standard silicon IC foundry processing and materials. The bimorph sensor structure is fabricated using low thermal expansion, high thermal isolation silicon oxide and oxynitride materials, and a high thermal expansion aluminum alloy bimetal. The microcantilever paddle is designed to move away from the substrate at elevated imaging temperatures, leading to large modeled sensor dynamic ranges (~16 bits). A temperature coefficient of capacitance, ▵C/C, (equivalent to TCR for microbolometers) above 30% has been modeled and measured for these structures, leading to modeled NEDT < 20 mK and thermal time constants in the 5-10 msec range giving a figure-of-merit [1] NEDT.Tau = 100-200 mK.msec. The development efforts to date have focused on the fabrication of 160x120 pixel arrays with 50 micron pitch pixels. Results from detailed thermo-electro-opto-mechanical modeling of the operation of these sensors are compared with experimental measurements from various test and integrated sensor structures and arrays.

  10. [Highly sensitive detection technology for biological toxins applying sugar epitopes].

    PubMed

    Uzawa, Hirotaka

    2009-01-01

    The Shiga toxin is a highly poisonous protein produced by enterohemorrhagic Escherichia coli O157. This bacterial toxin causes the hemolytic uremic syndrome. Another plant toxin from castor beans, ricin, is also highly toxic. The toxin was used for assassination in London. Recently, there were several cases of postal matter containing ricin. Both toxins are categorized as biological warfare agents by the Centers of Disease Control and Prevention. Conventional detection methods based on the antigen-antibody reaction, PCR and other cell-free assays have been proposed. However, those approaches have drawbacks in terms of sensitivity, analytical time, or stability of the detection reagents. Therefore, development of a facile and sensitive detection method is essential. Here we describe new detection methods applying carbohydrate epitopes as the toxin ligands, which is based on the fact that the toxins bind cell-surface oligosaccharides. Namely, the Shiga toxin has an affinity for globobiosyl (Gb(2)) disaccharide, and ricin binds the beta-D-galactose residue. For Shiga toxin detection, surface plasmon resonance (SPR) was applied. A polyanionic Gb(2)-glycopolymer was designed for this purpose, and it was used for the assembly of Gb(2)-chips using alternating layer-by-layer technology. The method allowed us to detect the toxin at a low concentration of LD(50). A synthetic carbohydrate ligand for ricin was designed and immobilized on the chips. SPR analysis with the chips allows us to detect ricin in a highly sensitive and facile manner (10 pg/ml, 5 min). Our present approaches provide a highly effective way to counter bioterrorism.

  11. Piezoelectric rubber films for highly sensitive impact measurement

    NASA Astrophysics Data System (ADS)

    Wang, Jhih-Jhe; Tsai, Jui-Wei; Su, Yu-Chuan

    2013-07-01

    We have successfully demonstrated the microfabrication of piezoelectric rubber films and their application in impact measurement. To realize the desired piezoelectricity and stretchability, cellular polydimethylsiloxane (PDMS) structures with micrometer-sized voids are internally implanted with bipolar charges, which function as dipoles and respond promptly to electromechanical stimuli. In the prototype demonstration, 300 µm thick cellular PDMS films are fabricated and internally coated with a thin polytetrafluoroethylene (PTFE) layer to secure the implanted charges. Meanwhile, the top and bottom surfaces of the cellular PDMS films are deposited with stretchable gold electrodes. An electric field up to 35 MV m-1 is applied across the gold electrodes to ionize the air in the voids and to implant charges on the inner surfaces. The resulting composite structures behave like rubber (with an elastic modulus of about 300 kPa) and show strong piezoelectricity (with a piezoelectric coefficient d33 higher than 1000 pC N-1). While integrated with a wide bandwidth and large dynamic-range charge amplifier, highly sensitive impact measurement (with a stress sensitivity of about 10 mV Pa-1) is demonstrated. As such, the demonstrated piezoelectric rubber films could potentially serve as a sensitive electromechanical material for low-frequency stimuli, and fulfill the needs of a variety of physiological monitoring and wearable electronics applications.

  12. Position sensitive detection of neutrons in high radiation background field

    SciTech Connect

    Vavrik, D.; Jakubek, J.; Pospisil, S.; Vacik, J.

    2014-01-15

    We present the development of a high-resolution position sensitive device for detection of slow neutrons in the environment of extremely high γ and e{sup −} radiation background. We make use of a planar silicon pixelated (pixel size: 55 × 55 μm{sup 2}) spectroscopic Timepix detector adapted for neutron detection utilizing very thin {sup 10}B converter placed onto detector surface. We demonstrate that electromagnetic radiation background can be discriminated from the neutron signal utilizing the fact that each particle type produces characteristic ionization tracks in the pixelated detector. Particular tracks can be distinguished by their 2D shape (in the detector plane) and spectroscopic response using single event analysis. A Cd sheet served as thermal neutron stopper as well as intensive source of gamma rays and energetic electrons. Highly efficient discrimination was successful even at very low neutron to electromagnetic background ratio about 10{sup −4}.

  13. Ultra-high sensitivity moment magnetometry of geological samples

    NASA Astrophysics Data System (ADS)

    Andrade Lima, E.; Weiss, B. P.

    2012-12-01

    Scanning SQUID microscopy offers a unique combination of high spatial resolution and magnetic field sensitivity that allows for the detection of magnetic moments as weak as 10^-16 Am2. This opens the possibility of extending paleomagnetic analyses to samples that have not been accessible to standard moment magnetometry, for which the detection limit is 10^-12 Am2. Of particular interest are individual terrestrial and extraterrestrial particles of small size (< 500 μm) that may preserve records of planetary dynamos and early nebular magnetic fields. Example targets include impact melt spherules, zircon and other silicate crystals, micrometeorites, cosmic dust, chondrules and refractory inclusions. These grains may be adequately modeled as small uniformly magnetized volumes, such that retrieving their magnetic moments from measured magnetic field maps does not require solving non-unique inverse problems. As a consequence, SQUID microscopes can be utilized as ultra-high sensitivity moment magnetometers. We show alternating field and thermal demagnetization data for several grains that demonstrate the performance of this technique. In addition, we compare scanning SQUID microscopy data with net moment measurements of the same samples performed by a commercial superconducting rock magnetometer. The results agree for stronger moments, as expected, but rapidly diverge as net moments fall below the lower 10^-10 Am2 range. These studies underscore the inability of conventional instruments not only to detect very weak moments but also to isolate contamination originating from background sources such as sample holders and mounts. We expect ultra-high sensitivity moment magnetometry using scanning SQUID microscopy will be a powerful tool in helping elucidate the formation of the solar system and planetary history.

  14. High sensitivity charge amplifier for ion beam uniformity monitor

    DOEpatents

    Johnson, Gary W.

    2001-01-01

    An ion beam uniformity monitor for very low beam currents using a high-sensitivity charge amplifier with bias compensation. The ion beam monitor is used to assess the uniformity of a raster-scanned ion beam, such as used in an ion implanter, and utilizes four Faraday cups placed in the geometric corners of the target area. Current from each cup is integrated with respect to time, thus measuring accumulated dose, or charge, in Coulombs. By comparing the dose at each corner, a qualitative assessment of ion beam uniformity is made possible. With knowledge of the relative area of the Faraday cups, the ion flux and areal dose can also be obtained.

  15. High-Sensitivity Measurement of Density by Magnetic Levitation.

    PubMed

    Nemiroski, Alex; Kumar, A A; Soh, Siowling; Harburg, Daniel V; Yu, Hai-Dong; Whitesides, George M

    2016-03-01

    This paper presents methods that use Magnetic Levitation (MagLev) to measure very small differences in density of solid diamagnetic objects suspended in a paramagnetic medium. Previous work in this field has shown that, while it is a convenient method, standard MagLev (i.e., where the direction of magnetization and gravitational force are parallel) cannot resolve differences in density <10(-4) g/cm(3) for macroscopic objects (>mm) because (i) objects close in density prevent each other from reaching an equilibrium height due to hard contact and excluded volume, and (ii) using weaker magnets or reducing the magnetic susceptibility of the medium destabilizes the magnetic trap. The present work investigates the use of weak magnetic gradients parallel to the faces of the magnets as a means of increasing the sensitivity of MagLev without destabilization. Configuring the MagLev device in a rotated state (i.e., where the direction of magnetization and gravitational force are perpendicular) relative to the standard configuration enables simple measurements along the axes with the highest sensitivity to changes in density. Manipulating the distance of separation between the magnets or the lengths of the magnets (along the axis of measurement) enables the sensitivity to be tuned. These modifications enable an improvement in the resolution up to 100-fold over the standard configuration, and measurements with resolution down to 10(-6) g/cm(3). Three examples of characterizing the small differences in density among samples of materials having ostensibly indistinguishable densities-Nylon spheres, PMMA spheres, and drug spheres-demonstrate the applicability of rotated Maglev to measuring the density of small (0.1-1 mm) objects with high sensitivity. This capability will be useful in materials science, separations, and quality control of manufactured objects. PMID:26815205

  16. Highly sensitive electronically modulated photoacoustic spectrometer for ozone detection.

    PubMed

    Gondal, M A; Yamani, Z H

    2007-10-10

    An ozone (O(3)) gas sensor with a sensitivity of parts per 10(9) (ppb) level and a high level of selectivity based on the resonant photoacoustic effect was developed using an electronically modulated cw CO(2) laser beam. Quite different from the standard chopper modulation of a laser beam, here the laser source was electronically modulated to overcome the inherent problem of frequency instability associated with chopper modulation. With electronic modulation, in conjunction with the fast Fourier transform (FFT) of transient signals, we were able to improve significantly the sensitivity of the photoacoustic (PA) system for the detection of O(3). In addition to the improved sensitivity, our method proved that the FFT of a laser modulated PA signal could suppress the noise signal generated by spurious window diffused absorption, which in the case of most commonly used lock-in techniques is rather unavoidable. The dependence of the PA signal on various experimental parameters such as buffer gas, laser power, modulation frequency, and trace gas concentration was investigated. In the case of buffer gas, argon proved to be more suitable than nitrogen and helium in terms of enhancing the sensitivity of the system. The limits of detection of O(3) using the 9 P(14) CO(2) laser line in our PA system are 5 parts per 10(9) by volume (ppbv) and 14 ppbv with electronic and standard chopper modulation, respectively. This detection limit of O(3) is quite applicable for detection of safe levels of O(3), at ground level. PMID:17932514

  17. High-Sensitivity Measurement of Density by Magnetic Levitation.

    PubMed

    Nemiroski, Alex; Kumar, A A; Soh, Siowling; Harburg, Daniel V; Yu, Hai-Dong; Whitesides, George M

    2016-03-01

    This paper presents methods that use Magnetic Levitation (MagLev) to measure very small differences in density of solid diamagnetic objects suspended in a paramagnetic medium. Previous work in this field has shown that, while it is a convenient method, standard MagLev (i.e., where the direction of magnetization and gravitational force are parallel) cannot resolve differences in density <10(-4) g/cm(3) for macroscopic objects (>mm) because (i) objects close in density prevent each other from reaching an equilibrium height due to hard contact and excluded volume, and (ii) using weaker magnets or reducing the magnetic susceptibility of the medium destabilizes the magnetic trap. The present work investigates the use of weak magnetic gradients parallel to the faces of the magnets as a means of increasing the sensitivity of MagLev without destabilization. Configuring the MagLev device in a rotated state (i.e., where the direction of magnetization and gravitational force are perpendicular) relative to the standard configuration enables simple measurements along the axes with the highest sensitivity to changes in density. Manipulating the distance of separation between the magnets or the lengths of the magnets (along the axis of measurement) enables the sensitivity to be tuned. These modifications enable an improvement in the resolution up to 100-fold over the standard configuration, and measurements with resolution down to 10(-6) g/cm(3). Three examples of characterizing the small differences in density among samples of materials having ostensibly indistinguishable densities-Nylon spheres, PMMA spheres, and drug spheres-demonstrate the applicability of rotated Maglev to measuring the density of small (0.1-1 mm) objects with high sensitivity. This capability will be useful in materials science, separations, and quality control of manufactured objects.

  18. Determination of a highly selective mixed-affinity sigma receptor ligand, in rat plasma by ultra performance liquid chromatography mass spectrometry and its application to a pharmacokinetic study

    PubMed Central

    Jamalapuram, Seshulatha; Vuppala, Pradeep K.; Mesangeau, Christophe; McCurdy, Christopher R.; Avery, Bonnie A.

    2014-01-01

    A selective, rapid and sensitive ultra performance liquid chromatography mass spectrometry (UPLC/MS) method was developed and validated to quantitate a highly selective mixed-affinity sigma receptor ligand, CM156 (3-(4-(4-cyclohexylpiperazin-1-yl)butyl)benzo[d] thiazole-2(3H)-thione), in rat plasma. CM156 and the internal standard (aripiprazole) were extracted from plasma samples by a single step liquid–liquid extraction using chloroform. The analysis was carried out on an ACQUITY UPLCTM BEH HILIC column (1.7 µm, 2.1 mm × 50 mm) with isocratic elution at flow rate of 0.2 mL/min using 10 mM ammonium formate in 0.1% formic acid and acetonitrile (10:90) as the mobile phase. The detection of the analyte was performed on a mass spectrometer operated in selected ion recording (SIR) mode with positive electrospray ionization (ESI). The validated analytical method resulted in a run time of 4 min and the retention times observed were 2.6 ± 0.1 and 2.1 ± 0.1 min for CM156 and the IS, respectively. The calibration curve exhibited excellent linearity over a concentration range of 5–4000 ng/mL with the lower limit of quantification of 5 ng/mL. The intra- and inter-day precision values were below 15% and accuracy ranged from −6.5% to 5.0%. The mean recovery of CM156 from plasma was 96.8%. The validated method was applied to a pilot intravenous pharmacokinetic study in rats. PMID:22406103

  19. High pressure-sensitive gene expression in Lactobacillus sanfranciscensis.

    PubMed

    Vogel, R F; Pavlovic, M; Hörmann, S; Ehrmann, M A

    2005-08-01

    Lactobacillus sanfranciscensis is a Gram-positive lactic acid bacterium used in food biotechnology. It is necessary to investigate many aspects of a model organism to elucidate mechanisms of stress response, to facilitate preparation, application and performance in food fermentation, to understand mechanisms of inactivation, and to identify novel tools for high pressure biotechnology. To investigate the mechanisms of the complex bacterial response to high pressure we have analyzed changes in the proteome and transcriptome by 2-D electrophoresis, and by microarrays and real time PCR, respectively. More than 16 proteins were found to be differentially expressed upon high pressure stress and were compared to those sensitive to other stresses. Except for one apparently high pressure-specific stress protein, no pressure-specific stress proteins were found, and the proteome response to pressure was found to differ from that induced by other stresses. Selected pressure-sensitive proteins were partially sequenced and their genes were identified by reverse genetics. In a transcriptome analysis of a redundancy cleared shot gun library, about 7% of the genes investigated were found to be affected. Most of them appeared to be up-regulated 2- to 4-fold and these results were confirmed by real time PCR. Gene induction was shown for some genes up-regulated at the proteome level (clpL/groEL/rbsK), while the response of others to high hydrostatic pressure at the transcriptome level seemed to differ from that observed at the proteome level. The up-regulation of selected genes supports the view that the cell tries to compensate for pressure-induced impairment of translation and membrane transport. PMID:16082466

  20. ALMA: Millimeter/submillimeter Astronomy at high sensitivity and resolution

    NASA Astrophysics Data System (ADS)

    Wootten, Alwyn; Corder, Stuartt Alan; Iono, Daisuke; Testi, Leonardo

    2015-08-01

    Vigorous and transformative investigation of the millimeter/submillimeter sky at high sensitivity and high resolution has benefitted from the recent completion of the Atacama Large Millimeter/submillimeter Array (ALMA), an effort of 22 countries. ALMA, a versatile interferometric telescope at 5000m elevation in the Atacama Desert of northern Chile, is comprised of sixty-six precision telescopes which may be arrayed over a 16 km extent on the high Chajnantor plain. Owing to its large collecting area of over 6600m^2 and its commodious spectral grasp of 8 GHz of spectrum in dual polarizations within an 84-950 GHz range, ALMA provides astronomers with vastly improved spectroscopic sensitivity. Spatial resolutions of 30 milliarcsec were demonstrated recently, revealing rings within the HL Tau protoplanetary disk, the rotating structure of the asteroid Juno and the molecular structure of the z~3 lensed galaxy SDP.81. The astrometric accuracy even at this early stage of deployment is better than 3 milliarcsec, providing improved ephemerides for the encounter of the New Horizons spacecraft with the Pluto-Charon system. Very long baseline capability is expected to bring microarcsecond imaging to a worldwide array anchored by ALMA with potential for imaging nearby Black Holes on the scales of their Event Horizons.ALMA's huge collecting area has enabled detection of lines of C, N and CO and continuum for characterization of massive complexes near the Era of Recombination. ALMA's sensitivity and resolution have enabledmeasurement of molecular emission through cosmic time from numerous molecules characterizing galactic star-forming regions and tracing their kinematics near active nuclei, starbursts, interacting clouds and quiescent disks. ALMA's sensitivity, resolution and spectral grasp have enabled it to image molecules and dust characterizing circumstellar disks and embedded bodies in protostellar, transition and debris stages of development.ALMA is a partnership of ESO

  1. Coumarin-bearing triarylamine sensitizers with high molar extinction coefficient for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Zhong, Changjian; Gao, Jianrong; Cui, Yanhong; Li, Ting; Han, Liang

    2015-01-01

    Coumarin unit is introduced into triarylamine and three organic sensitizers are designed and synthesized with triarylamine bearing coumarin moiety as the electron donor, conjugated system containing thiophene unit as the π-bridge, and cyanoacetic acid moiety as the electron acceptor. The light-harvesting capabilities and photovoltaic performance of these dyes are investigated systematically with the comparison of different π-bridges. High molar extinction coefficients are observed in these triarylamine dyes and the photocurrent and photovoltage are increased with the introduction of another thiophene or benzene. Optimal photovoltaic performance (η = 6.24%, Voc = 690 mV, Jsc = 14.33 mA cm-2, and ff = 0.63) is observed in the DSSC based on dye with thiophene-phenyl unit as the π-conjugated bridge under 100 mW cm-2 simulated AM 1.5 G solar irradiation.

  2. High refractive index and temperature sensitivity LPGs for high temperature operation

    NASA Astrophysics Data System (ADS)

    Nascimento, I. M.; Gouveia, C.; Jana, Surnimal; Bera, Susanta; Baptista, J. M.; Moreira, Paulo; Biwas, Palas; Bandyopadhyay, Somnath; Jorge, Pedro A. S.

    2013-11-01

    A fiber optic sensor for high sensitivity refractive index and temperature measurement able to withstand temperature up to 450 °C is reported. Two identical LPG gratings were fabricated, whereas one was coated with a high refractive index (~1.78) sol-gel thin film in order to increase its sensitivity to the external refractive index. The two sensors were characterized and compared in refractive index and temperature. Sensitivities of 1063 nm/RIU (1.338 - 1.348) and 260 pm/°C were achieved for refractive index and temperature, respectively.

  3. Highly sensitive Raman system for dissolved gas analysis in water.

    PubMed

    Yang, Dewang; Guo, Jinjia; Liu, Qingsheng; Luo, Zhao; Yan, Jingwen; Zheng, Ronger

    2016-09-20

    The detection of dissolved gases in seawater plays an important role in ocean observation and exploration. As a potential technique for oceanic applications, Raman spectroscopy has already proved its advantages in the simultaneous detection of multiple species during previous deep-sea explorations. Due to the low sensitivity of conventional Raman measurements, there have been many reports of Raman applications on direct seawater detection in high-concentration areas, but few on undersea dissolved gas detection. In this work, we have presented a highly sensitive Raman spectroscopy (HSRS) system with a special designed gas chamber for small amounts of underwater gas extraction. Systematic experiments have been carried out for system evaluation, and the results have shown that the Raman signals obtained by the innovation of a near-concentric cavity was about 21 times stronger than those of conventional side-scattering Raman measurements. Based on this system, we have achieved a low limit of detection of 2.32 and 0.44  μmol/L for CO2 and CH4, respectively, in the lab. A test-out experiment has also been accomplished with a gas-liquid separator coupled to the Raman system, and signals of O2 and CO2 were detected after 1 h of degasification. This system may show potential for gas detection in water, and further work would be done for the improvement of in situ detection.

  4. High-sensitivity acoustic sensors from nanofibre webs

    PubMed Central

    Lang, Chenhong; Fang, Jian; Shao, Hao; Ding, Xin; Lin, Tong

    2016-01-01

    Considerable interest has been devoted to converting mechanical energy into electricity using polymer nanofibres. In particular, piezoelectric nanofibres produced by electrospinning have shown remarkable mechanical energy-to-electricity conversion ability. However, there is little data for the acoustic-to-electric conversion of electrospun nanofibres. Here we show that electrospun piezoelectric nanofibre webs have a strong acoustic-to-electric conversion ability. Using poly(vinylidene fluoride) as a model polymer and a sensor device that transfers sound directly to the nanofibre layer, we show that the sensor devices can detect low-frequency sound with a sensitivity as high as 266 mV Pa−1. They can precisely distinguish sound waves in low to middle frequency region. These features make them especially suitable for noise detection. Our nanofibre device has more than five times higher sensitivity than a commercial piezoelectric poly(vinylidene fluoride) film device. Electrospun piezoelectric nanofibres may be useful for developing high-performance acoustic sensors. PMID:27005010

  5. High-sensitivity acoustic sensors from nanofibre webs.

    PubMed

    Lang, Chenhong; Fang, Jian; Shao, Hao; Ding, Xin; Lin, Tong

    2016-01-01

    Considerable interest has been devoted to converting mechanical energy into electricity using polymer nanofibres. In particular, piezoelectric nanofibres produced by electrospinning have shown remarkable mechanical energy-to-electricity conversion ability. However, there is little data for the acoustic-to-electric conversion of electrospun nanofibres. Here we show that electrospun piezoelectric nanofibre webs have a strong acoustic-to-electric conversion ability. Using poly(vinylidene fluoride) as a model polymer and a sensor device that transfers sound directly to the nanofibre layer, we show that the sensor devices can detect low-frequency sound with a sensitivity as high as 266 mV Pa(-1). They can precisely distinguish sound waves in low to middle frequency region. These features make them especially suitable for noise detection. Our nanofibre device has more than five times higher sensitivity than a commercial piezoelectric poly(vinylidene fluoride) film device. Electrospun piezoelectric nanofibres may be useful for developing high-performance acoustic sensors. PMID:27005010

  6. High Sensitivity, Low Volume Method to Determine Dissolved Phosphorus

    NASA Astrophysics Data System (ADS)

    Haberer, J. L.; Brandes, J. A.

    2001-12-01

    A high sensitivity, low volume method was developed to determine nanomolar concentrations of soluble reactive phosphorus (SRP) using reverse phase HPLC. The technique in determining SRP involved using methods from Strickland and Parsons, 1972 and Karl and Tien, 1992. Various techniques for improving blanks and sensitivity will be discussed. The method was applied to seawater and freshwater samples taken from the estuarine Nueces Delta system, Texas, two sites in the Gulf of Mexico, and within two upland (2400 m) forest catchments in the Peruvian Andes. One catchment was partially deforested within the last 3 years, while the other has remained untouched. Samples in the Gulf of Mexico were taken at a series of coastal and open water stations at various depths. Samples in each of the two upland forest catchments in Peru were obtained at 33.3 m distance intervals along a 100 m reach. Samples were taken in the Nueces River, Texas upland from a marsh estuary and from high and low regions of the marsh. Comparisons are made between the forest catchment sites in addition to comparisons made in the Nueces marsh estuary/river system. Depth profiles of SRP in the Gulf of Mexico are established. Future studies should be conducted to investigate phosphate in sediment pore waters. This method has many potential applications, is scalable across a wide range of sample volumes, and can be automated.

  7. Highly sensitive Raman system for dissolved gas analysis in water.

    PubMed

    Yang, Dewang; Guo, Jinjia; Liu, Qingsheng; Luo, Zhao; Yan, Jingwen; Zheng, Ronger

    2016-09-20

    The detection of dissolved gases in seawater plays an important role in ocean observation and exploration. As a potential technique for oceanic applications, Raman spectroscopy has already proved its advantages in the simultaneous detection of multiple species during previous deep-sea explorations. Due to the low sensitivity of conventional Raman measurements, there have been many reports of Raman applications on direct seawater detection in high-concentration areas, but few on undersea dissolved gas detection. In this work, we have presented a highly sensitive Raman spectroscopy (HSRS) system with a special designed gas chamber for small amounts of underwater gas extraction. Systematic experiments have been carried out for system evaluation, and the results have shown that the Raman signals obtained by the innovation of a near-concentric cavity was about 21 times stronger than those of conventional side-scattering Raman measurements. Based on this system, we have achieved a low limit of detection of 2.32 and 0.44  μmol/L for CO2 and CH4, respectively, in the lab. A test-out experiment has also been accomplished with a gas-liquid separator coupled to the Raman system, and signals of O2 and CO2 were detected after 1 h of degasification. This system may show potential for gas detection in water, and further work would be done for the improvement of in situ detection. PMID:27661606

  8. Highly sensitive detection of urinary cadmium to assess personal exposure.

    PubMed

    Argun, Avni A; Banks, Ashley M; Merlen, Gwendolynne; Tempelman, Linda A; Becker, Michael F; Schuelke, Thomas; Dweik, Badawi M

    2013-04-22

    A series of Boron-Doped Diamond (BDD) ultramicroelectrode arrays were fabricated and investigated for their performance as electrochemical sensors to detect trace level metals such as cadmium. The steady-state diffusion behavior of these sensors was validated using cyclic voltammetry followed by electrochemical detection of cadmium in water and in human urine to demonstrate high sensitivity (>200 μA ppb(-1) cm(-2)) and low background current (<4 nA). When an array of ultramicroelectrodes was positioned with optimal spacing, these BDD sensors showed a sigmoidal diffusion behavior. They also demonstrated high accuracy with linear dose dependence for quantification of cadmium in a certified reference river water sample from the U.S. National Institute of Standards and Technology (NIST) as well as in a human urine sample spiked with 0.25-1 ppb cadmium. PMID:23561905

  9. Design of a charge sensitive preamplifier on high resistivity silicon

    SciTech Connect

    Radeka, V.; Rehak, P.; Rescia, S.; Gatti, E.; Longoni, A.; Sampietro, M.; Holl, P.; Strueder, L.; Kemmer, J.

    1987-01-01

    A low noise, fast charge sensitive preamplifier was designed on high resistivity, detector grade silicon. It is built at the surface of a fully depleted region of n-type silicon. This allows the preamplifier to be placed very close to a detector anode. The preamplifier uses the classical input cascode configuration with a capacitor and a high value resistor in the feedback loop. The output stage of the preamplifier can drive a load up to 20pF. The power dissipation of the preamplifier is 13mW. The amplifying elements are ''Single Sided Gate JFETs'' developed especially for this application. Preamplifiers connected to a low capacitance anode of a drift type detector should achieve a rise time of 20ns and have an equivalent noise charge (ENC), after a suitable shaping, of less than 50 electrons. This performance translates to a position resolution better than 3..mu..m for silicon drift detectors. 6 refs., 9 figs.

  10. Coherent Raman Scattering: Methods Towards Imaging with High Sensitivity

    NASA Astrophysics Data System (ADS)

    Bachler, Brandon Richard

    Coherent Raman spectroscopy is a powerful tool for molecular identification. For imaging applications, Raman spectroscopy techniques have offered a way of achieving endogenous chemical contrast without the need for fluorescent labeling. Increasing the sensitivity of Raman scattering microscopy is vital to performing high speed, chemically selective imaging. This thesis presents three experiments with the ultimate goal of increasing the sensitivity and quantifying limitations of different Raman techniques. The first experiment is a comparison of spontaneous and coherent Raman signal strengths under biological imaging conditions. While it is commonly stated in the literature that coherent Raman techniques provide orders of magnitude higher signal than spontaneous Raman, such a comparison has not been done under the low concentration, low excitation power conditions relevant for biological imaging. We determine a critical power above which coherent Raman methods provide higher signal and below which spontaneous Raman methods provide higher sensitivity. Contrary to what is commonly stated in the literature, spontaneous Raman can provide higher signal levels under common biological imaging conditions. The second experiment is a demonstration of the first multiplexed Raman-induced Kerr effect (BIKES) microscopy setup to date. We compare the signal-to-noise ratios between femtosecond stimulated Raman (FSRS) and RIKES for spectroscopy applications in solution and for microscopy applications with polystyrene beads. We find that for our samples, RIKES consistently provides a higher signal-to-noise ratio than FSRS for both applications. We also use RIKES microscopy to map out the distribution of cytoplasm in onion cells. Finally, a surface-enhanced Raman experiment is performed to observe and compare highly enhanced signals for spontaneous and coherent Raman spectroscopy. We use a commercial SERS substrate and observe significantly enhanced spontaneous Raman signals from

  11. Luminescent Lanthanide Reporters for High-Sensitivity Novel Bioassays.

    SciTech Connect

    Anstey, Mitchell R.; Fruetel, Julia A.; Foster, Michael E.; Hayden, Carl C.; Buckley, Heather L.; Arnold, John

    2013-09-01

    Biological imaging and assay technologies rely on fluorescent organic dyes as reporters for a number of interesting targets and processes. However, limitations of organic dyes such as small Stokes shifts, spectral overlap of emission signals with native biological fluorescence background, and photobleaching have all inhibited the development of highly sensitive assays. To overcome the limitations of organic dyes for bioassays, we propose to develop lanthanide-based luminescent dyes and demonstrate them for molecular reporting applications. This relatively new family of dyes was selected for their attractive spectral and chemical properties. Luminescence is imparted by the lanthanide atom and allows for relatively simple chemical structures that can be tailored to the application. The photophysical properties offer unique features such as narrow and non-overlapping emission bands, long luminescent lifetimes, and long wavelength emission, which enable significant sensitivity improvements over organic dyes through spectral and temporal gating of the luminescent signal.Growth in this field has been hindered due to the necessary advanced synthetic chemistry techniques and access to experts in biological assay development. Our strategy for the development of a new lanthanide-based fluorescent reporter system is based on chelation of the lanthanide metal center using absorbing chromophores. Our first strategy involves "Click" chemistry to develop 3-fold symmetric chelators and the other involves use of a new class of tetrapyrrole ligands called corroles. This two-pronged approach is geared towards the optimization of chromophores to enhance light output.

  12. A highly sensitive fiber Bragg grating diaphragm pressure transducer

    NASA Astrophysics Data System (ADS)

    Allwood, Gary; Wild, Graham; Lubansky, Alex; Hinckley, Steven

    2015-10-01

    In this work, a novel diaphragm based pressure transducer with high sensitivity is described, including the physical design structure, in-depth analysis of optical response to changes in pressure, and a discussion of practical implementation and limitations. A flat circular rubber membrane bonded to a cylinder forms the body of the transducer. A fiber Bragg grating bonded to the center of the diaphragm structure enables the fractional change in pressure to be determined by analyzing the change in Bragg wavelength of the reflected spectra. Extensive evaluation of the physical properties and optical characteristics of the transducer has been performed through experimentation, and modeling using small deformation theory. The results show the transducer has a sensitivity of 0.116 nm/kPa, across a range of 15 kPa. Ultra-low cost interrogation of the optical signal was achieved through the use of an optically mismatched Bragg grating acting as an edge filter to convert the spectral change into an intensity change. A numerical model of the intensity based interrogation was implemented in order to validate the experimental results. Utilizing this interrogation technique and housing both the sensing and reference Bragg gratings within the main body of the transducer means it is effectively temperature insensitive and easily connected to electronic systems.

  13. Highly sensitive flow-injection chemiluminescence determination of pyrogallol compounds

    NASA Astrophysics Data System (ADS)

    Kanwal, Shamsa; Fu, Xiaohong; Su, Xingguang

    2009-12-01

    A highly sensitive flow-injection chemiluminescent method for the direct determination of pyrogallol compounds has been developed. Proposed method is based on the enhanced effect of pyrogallol compounds on the chemiluminescence signals of KMnO 4-H 2O 2 system in slightly alkaline medium. Three important pyrogallol compounds, pyrogallic acid, gallic acid and tannic acid, have been detected by this method, and the possible mechanism of the CL reaction is also discussed. The proposed method is simple, convenient, rapid (60 samples h -1), and sensitive, has a linear range of 8 × 10 -10 mol L -1 to 1 × 10 -5 mol L -1, for pyrogallic acid, with a detection limit of 6 × 10 -11 mol L -1, 4 × 10 -8 mol L -1 to 5 × 10 -3 mol L -1 for gallic acid with a detection limit of 9 × 10 -10 mol L -1, and 8 × 10 -8 mol L -1 to 5 × 10 -2 mol L -1 for tannic acid, with a detection limit of 2 × 10 -9 mol L -1, respectively. The relative standard deviation (RSD, n = 15) was 0.8, 1.1 and 1.3% for 5 × 10 -6 mol L -1 pyrogallic acid, gallic acid and tannic acid, respectively. The proposed method was successfully applied to the determination of pyrogallol compounds in tea and coffee samples.

  14. High sensitivity tracking of CD-SEM performance: QSEM

    NASA Astrophysics Data System (ADS)

    Babin, S.; Huang, Jaffee; Yushmanov, P.

    2015-03-01

    The performance of CD-SEMs directly affects the measured values of critical dimensions (CDs) at the time of their measurement. Tracking the performance of CD-SEMs is necessary to establish trust in their results and provide guidance for preventive maintenance and tune-ups. When the measured CDs are out of specification in manufacturing, it is crucial to determine whether this is due to process variation or the metrology tool itself. Multiple methods that use linewidth measurements have been employed thus far; however, they suffer from linewidth variations on the wafer, as well as from variations of line edge and linewidth roughness. Here, we report a method that is capable of providing a quantitative extraction of the SEM performance based on advanced algorithms. The method is independent of linewidth, line edge roughness and linewidth roughness, and has high sensitivity. This software, QSEM, was developed to automatically evaluate image quality and assign a value to that quality. The image quality value is based on multiple factors such as noise, sharpness, analysis of histograms, and contrast. The sensitivity of the software was evaluated; a good correlation between image quality results and linewidth variation due to SEM performance was established. Using QSEM to analyze SEM images allows the performance of CDSEMs to be tracked for proper calibration and preventive maintenance, as well as to resolve the dispute between failure in the process or the metrology.

  15. High sensitivity permeation measurement system for 'ultrabarrier' thin films

    SciTech Connect

    Zhang Xiaodong; Lewis, Jay S.; Wolter, Scott D.; Parker, Charles B.; Glass, Jeffrey T.

    2007-11-15

    The authors demonstrate a new technique for high sensitivity gas permeation measurements by integrating mass spectrometry with programed accumulation, detection, and evacuation of permeant. After passing through the film of interest, the gas permeant is captured and accumulated in an isolated ultrahigh vacuum (UHV) volume. The permeant is then allowed to enter an adjacent residual gas analyzer (RGA) and the resulting partial pressure increase is correlated with the steady state permeation rate. Calibrated results are given for helium and argon permeation through polymer films. The measured detection limits of the system are 1.8x10{sup -4} cm{sup 3}/m{sup 2} day for helium and 2.5x10{sup -4} cm{sup 3}/m{sup 2} day for argon. Both values are several orders of magnitude lower than what is available from commercial instruments or similar RGA-based instruments. Potential applications of this technique include measurement of oxygen and water vapor permeation with sensitivities required for assessment of ultrabarrier coatings.

  16. PlanetPol: A Very High Sensitivity Polarimeter

    NASA Astrophysics Data System (ADS)

    Hough, J. H.; Lucas, P. W.; Bailey, J. A.; Tamura, M.; Hirst, E.; Harrison, D.; Bartholomew-Biggs, M.

    2006-09-01

    We have built and used on several occasions an optical broadband stellar polarimeter, PlanetPol, which employs photoelastic modulators and avalanche photodiodes and achieves a photon-noise-limited sensitivity of at least 1 in 106 in fractional polarization. Observations of a number of polarized standards taken from the literature show that the accuracy of polarization measurements is ~1%. We have developed a method for accurately measuring the polarization of altitude-azimuth mounted telescopes by observing bright nearby stars at different parallactic angles, and we find that the on-axis polarization of the William Herschel Telescope is typically ~15 × 10-6, measured with an accuracy of a few parts in 107. The nearby stars (distance less than 32 pc) are found to have very low polarizations, typically a few ×10-6, indicating that very little interstellar polarization is produced close to the Sun and that their intrinsic polarization is also low. Although the polarimeter can be used for a wide range of astronomy, the very high sensitivity was set by the goal of detecting the polarization signature of unresolved extrasolar planets.

  17. Kinetics of Highly Sensitive Troponin T after Cardiac Surgery.

    PubMed

    Omar, Amr S; Sudarsanan, Suraj; Hanoura, Samy; Osman, Hany; Sivadasan, Praveen C; Shouman, Yasser; Tuli, Alejandro Kohn; Singh, Rajvir; Al Khulaifi, Abdulaziz

    2015-01-01

    Perioperative myocardial infarction (PMI) confers a considerable risk in cardiac surgery settings; finding the ideal biomarker seems to be an ideal goal. Our aim was to assess the diagnostic accuracy of highly sensitive troponin T (hsTnT) in cardiac surgery settings and to define a diagnostic level for PMI diagnosis. This was a single-center prospective observational study analyzing data from all patients who underwent cardiac surgeries. The primary outcome was the diagnosis of PMI through a specific level. The secondary outcome measures were the lengths of mechanical ventilation (LOV), stay in the intensive care unit (LOSICU), and hospitalization. Based on the third universal definition of PMI, patients were divided into two groups: no PMI (Group I) and PMI (Group II). Data from 413 patients were analyzed. Nine patients fulfilled the diagnostic criteria of PMI, while 41 patients were identified with a 5-fold increase in their CK-MB (≥ 120 U/L). Using ROC analysis, a hsTnT level of 3,466 ng/L or above showed 90% sensitivity and 90% specificity for the diagnosis of PMI. Secondary outcome measures in patients with PMI were significantly prolonged. In conclusion, the hsTnT levels detected here paralleled those of CK-MB and a cut-off level of 3466 ng/L could be diagnostic of PMI. PMID:26539512

  18. Sensitivity of once-shocked, weathered high explosives

    SciTech Connect

    Williams, K.L.; Harris, B.W.

    1998-07-01

    Effects caused by stimulating once-shocked, weathered high explosives (OSW-HE) are investigated. The sensitivity of OSW-HE to mechanical stimuli was determined using standard industry tests. Some initial results are given. Pieces of OSW-HE were collected from active and inactive firing sites and from an area surrounding a drop tower at Los Alamos where skid and spigot tests were done. Samples evaluated were cast explosives or plastic bonded explosive (PBX) formulations containing cyclotrimethylenetrinitramine (RDX), cyclotetramethylene tetranitramine (HMX), 2,4,6-trinitrotoluene (TNT), mock or inert HE [tris(beta-chloroethyl)phosphate (CEF)], barium nitrate, cyanuric acid, talc, and Kel-F. Once-shocked, weathered LX-10 Livermore explosive [HMX/Viton A, (95/5 wt %)], PBX 9011 [HMX/Estane, (90/10 wt %)], PBX 9404 [HMX/nitrocellulose, tris(beta-chloroethyl) phosphate, (94/3/3 wt %)], Composition B or cyclotol (TNT/RDX explosives), and PBX 9007 (90% RDX, 9.1% styrene, 0.5% dioctyl phthalate, and 0.45 resin) were subjected to the hammer test, the drop-weight impact sensitivity test, differential thermal analysis (DTA), the spark test, the Henkin`s critical temperature test, and the flame test. Samples were subjected to remote, wet cutting and drilling; remote, liquid-nitrogen-cooled grinding and crushing; and scanning electron microscope (SEM) surface analyses for morphological changes.

  19. High-sensitivity quantitative phase microcopy (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Zhou, Renjie; Kuang, Cuifang; Hosseini, Poorya; Chowdhary, Ravi; Yaqoob, Zahid; So, Peter T. C.

    2016-03-01

    In the past decade, various quantitative phase microscopy (QPM) techniques have emerged, driven by the need to study biological samples non-invasively. However, the fundamental limit for phase noise is scarcely discussed in the literature. In a typically off-axis phase microscope system, the phase noise is limited to a few milliradians using a moderate camera. Common-path QPMs offer much reduced phase noise compared to typical Mach-Zehnder-based systems. However, further scaling down the phase noise becomes difficult. Here we propose a high-sensitivity common-path QPM that promises to reduce the phase noise by a factor of 10 (assuming the mechanical noise is negligible). This is achieved by a specifically designed signal filter, leaving only the subtle phase fluctuations coming from the dynamics sample scattering. By working at photon shot-noise limited detection, we can magnify the subtle phase contrast which is proportional to the camera well depth. We expect this system to have the height sensitivity similar to an atomic force microcopy, while measuring biological structures with a full field of view in a single-shot. We plan to use this system to study cell dynamics, particularly lamellipodial height fluctuations as well as stiffer cell membrane fluctuations.

  20. Nanoparticle-Structured Highly Sensitive and Anisotropic Gauge Sensors.

    PubMed

    Zhao, Wei; Luo, Jin; Shan, Shiyao; Lombardi, Jack P; Xu, Yvonne; Cartwright, Kelly; Lu, Susan; Poliks, Mark; Zhong, Chuan-Jian

    2015-09-16

    The ability to tune gauge factors in terms of magnitude and orientation is important for wearable and conformal electronics. Herein, a sensor device is described which is fabricated by assembling and printing molecularly linked thin films of gold nanoparticles on flexible microelectrodes with unusually high and anisotropic gauge factors. A sharp difference in gauge factors up to two to three orders of magnitude between bending perpendicular (B(⊥)) and parallel (B(||)) to the current flow directions is observed. The origin of the unusual high and anisotropic gauge factors is analyzed in terms of nanoparticle size, interparticle spacing, interparticle structure, and other parameters, and by considering the theoretical aspects of electron conduction mechanism and percolation pathway. A critical range of resistivity where a very small change in strain and the strain orientation is identified to impact the percolation pathway in a significant way, leading to the high and anisotropic gauge factors. The gauge anisotropy stems from molecular and nanoscale fine tuning of interparticle properties of molecularly linked nanoparticle assembly on flexible microelectrodes, which has important implication for the design of gauge sensors for highly sensitive detection of deformation in complex sensing environment or on complex curved surfaces such as wearable electronics and skin sensors.

  1. Magnetic probe array with high sensitivity for fluctuating field.

    PubMed

    Kanamaru, Yuki; Gota, Hiroshi; Fujimoto, Kayoko; Ikeyama, Taeko; Asai, Tomohiko; Takahashi, Tsutomu; Nogi, Yasuyuki

    2007-03-01

    A magnetic probe array is constructed to measure precisely the spatial structure of a small fluctuating field included in a strong confinement field that varies with time. To exclude the effect of the confinement field, the magnetic probes consisting of figure-eight-wound coils are prepared. The spatial structure of the fluctuating field is obtained from a Fourier analysis of the probe signal. It is found that the probe array is more sensitive to the fluctuating field with a high mode number than that with a low mode number. An experimental demonstration of the present method is attempted using a field-reversed configuration plasma, where the fluctuating field with 0.1% of the confinement field is successfully detected.

  2. Radiation noise in a high sensitivity star sensor

    NASA Technical Reports Server (NTRS)

    Parkinson, J. B.; Gordon, E.

    1972-01-01

    An extremely accurate attitude determination was developed for space applications. This system uses a high sensitivity star sensor in which the photomultiplier tube is subject to noise generated by space radiations. The space radiation induced noise arises from trapped electrons, solar protons and other ionizing radiations, as well as from dim star background. The solar activity and hence the electron and proton environments are predicted through the end of the twentieth century. The available data for the response of the phototube to proton, electron, gamma ray, and bremsstrahlung radiations are reviewed and new experimental data is presented. A simulation was developed which represents the characteristics of the effect of radiations on the star sensor, including the non-stationarity of the backgrounds.

  3. Versatile, high-sensitivity faraday cup array for ion implanters

    DOEpatents

    Musket, Ronald G.; Patterson, Robert G.

    2003-01-01

    An improved Faraday cup array for determining the dose of ions delivered to a substrate during ion implantation and for monitoring the uniformity of the dose delivered to the substrate. The improved Faraday cup array incorporates a variable size ion beam aperture by changing only an insertable plate that defines the aperture without changing the position of the Faraday cups which are positioned for the operation of the largest ion beam aperture. The design enables the dose sensitivity range, typically 10.sup.11 -10.sup.18 ions/cm.sup.2 to be extended to below 10.sup.6 ions/cm.sup.2. The insertable plate/aperture arrangement is structurally simple and enables scaling to aperture areas between <1 cm.sup.2 and >750 cm.sup.2, and enables ultra-high vacuum (UHV) applications by incorporation of UHV-compatible materials.

  4. Graphene nanomesh as highly sensitive chemiresistor gas sensor.

    PubMed

    Paul, Rajat Kanti; Badhulika, Sushmee; Saucedo, Nuvia M; Mulchandani, Ashok

    2012-10-01

    Graphene is a one atom thick carbon allotrope with all surface atoms that has attracted significant attention as a promising material as the conduction channel of a field-effect transistor and chemical field-effect transistor sensors. However, the zero bandgap of semimetal graphene still limits its application for these devices. In this work, ethanol-chemical vapor deposition (CVD) of a grown p-type semiconducting large-area monolayer graphene film was patterned into a nanomesh by the combination of nanosphere lithography and reactive ion etching and evaluated as a field-effect transistor and chemiresistor gas sensors. The resulting neck-width of the synthesized nanomesh was about ∼20 nm and was comprised of the gap between polystyrene (PS) spheres that was formed during the reactive ion etching (RIE) process. The neck-width and the periodicities of the graphene nanomesh (GNM) could be easily controlled depending on the duration/power of the RIE and the size of the PS nanospheres. The fabricated GNM transistor device exhibited promising electronic properties featuring a high drive current and an I(ON)/I(OFF) ratio of about 6, significantly higher than its film counterpart. Similarly, when applied as a chemiresistor gas sensor at room temperature, the graphene nanomesh sensor showed excellent sensitivity toward NO(2) and NH(3), significantly higher than their film counterparts. The ethanol-based graphene nanomesh sensors exhibited sensitivities of about 4.32%/ppm in NO(2) and 0.71%/ppm in NH(3) with limits of detection of 15 and 160 ppb, respectively. Our demonstrated studies on controlling the neck width of the nanomesh would lead to further improvement of graphene-based transistors and sensors.

  5. Graphene nanomesh as highly sensitive chemiresistor gas sensor.

    PubMed

    Paul, Rajat Kanti; Badhulika, Sushmee; Saucedo, Nuvia M; Mulchandani, Ashok

    2012-10-01

    Graphene is a one atom thick carbon allotrope with all surface atoms that has attracted significant attention as a promising material as the conduction channel of a field-effect transistor and chemical field-effect transistor sensors. However, the zero bandgap of semimetal graphene still limits its application for these devices. In this work, ethanol-chemical vapor deposition (CVD) of a grown p-type semiconducting large-area monolayer graphene film was patterned into a nanomesh by the combination of nanosphere lithography and reactive ion etching and evaluated as a field-effect transistor and chemiresistor gas sensors. The resulting neck-width of the synthesized nanomesh was about ∼20 nm and was comprised of the gap between polystyrene (PS) spheres that was formed during the reactive ion etching (RIE) process. The neck-width and the periodicities of the graphene nanomesh (GNM) could be easily controlled depending on the duration/power of the RIE and the size of the PS nanospheres. The fabricated GNM transistor device exhibited promising electronic properties featuring a high drive current and an I(ON)/I(OFF) ratio of about 6, significantly higher than its film counterpart. Similarly, when applied as a chemiresistor gas sensor at room temperature, the graphene nanomesh sensor showed excellent sensitivity toward NO(2) and NH(3), significantly higher than their film counterparts. The ethanol-based graphene nanomesh sensors exhibited sensitivities of about 4.32%/ppm in NO(2) and 0.71%/ppm in NH(3) with limits of detection of 15 and 160 ppb, respectively. Our demonstrated studies on controlling the neck width of the nanomesh would lead to further improvement of graphene-based transistors and sensors. PMID:22931286

  6. Introducing wet aerosols into the static high sensitivity ICP (SHIP).

    PubMed

    Scheffer, Andy; Engelhard, Carsten; Sperling, Michael; Buscher, Wolfgang

    2007-08-01

    A demountable design of the static high sensitivity ICP (SHIP) for optical emission spectrometry is presented, and its use as an excitation source with the introduction of wet aerosols was investigated. Aerosols were produced by standard pneumatic sample introduction systems, namely a cross flow nebulizer, Meinhard nebulizer and PFA low flow nebulizer, which have been applied in conjunction with a double pass and a cyclonic spray chamber. The analytical capabilities of these sample introduction systems in combination with the SHIP system were evaluated with respect to the achieved sensitivity. It was found that a nebulizer tailored for low argon flow rates (0.3-0.5 L min(-1)) is best suited for the low flow plasma (SHIP). An optimization of all gas flow rates of the SHIP system with the PFA low flow nebulizer was carried out in a two-dimensional way with the signal to background ratio (SBR) and the robustness as optimization target parameters. Optimum conditions for a torch model with 1-mm injector tube were 0.25 and 0.36 L min(-1) for the plasma gas and the nebulizer gas, respectively. A torch model with a 2-mm injector tube was optimized to 0.4 L min(-1) for the plasma gas and 0.44 L min(-1) for the nebulizer gas. In both cases the SHIP system saves approximately 95% of the argon consumed by conventional inductively coupled plasma systems. The limits of detection were found to be in the low microgram per litre range and below for many elements, which was quite comparable to those of the conventional setup. Furthermore, the short-term stability and the wash out behaviour of the SHIP were investigated. Direct comparison with the conventional setup indicated that no remarkable memory effects were caused by the closed design of the torch. The analysis of a NIST SRM 1643e (Trace Elements in Water) with the SHIP yielded recoveries of 97-103% for 13 elements, measured simultaneously.

  7. High-sensitivity (25-um pitch) microbolometer FPAs

    NASA Astrophysics Data System (ADS)

    Murphy, Daniel F.; Ray, Michael; Wyles, Richard; Asbrock, James F.; Lum, Nancy A.; Kennedy, Adam; Wyles, Jessica; Hewitt, C.; Graham, Glen E.; Horikiri, Tad; Anderson, John S.; Bradley, Daryl; Chin, Richard; Kostrzewa, Thomas

    2001-11-01

    RIO has achieved a significant technical breakthrough in uncooled FPAs by reducing the pixel size by a factor of two while maintaining state-of-the-art sensitivity. Raytheon has produced high-quality 320 by 240 micro bolometer FPAs with 25 micrometers pitch pixels. The 320 by 240 FPAs have a sensitivity that is comparable to micro bolometer FPAs with 50 micrometers pixels. The average NETD value for these FPAs is about 35 mK with an f/1 aperture and operating at 30 Hz frame rates. Good pixel operability and excellent image quality have been demonstrated. Pixel operability is greater than 99 percent on some FPAs, and uncorrected responsivity nonuniformity is less than 4 percent. The micro bolometer detectors also have a relatively fast thermal time constant of approximately 10 msec. This state-of-the-art performance has been achieved as a result of an advanced micromachining fabrication process. The process allows maximization of both the thermal isolation and the optical fill-factor. The reduction in pixel size offers several potential benefits for IR systems. For a given system resolution requirement, the 225 micrometers pixels allow a factor of two reduction in both the focal length and aperture size of the sensor optics. The pixel size reduction facilitates a significant FPA cost reduction since the number of die printed on a wafer can be increased. The pixel size reduction has enabled the development of a large-format 640 by 512 FPA array applicable to wide-field-of-view, long range surveillance and targeting missions, and a 160 by 128 array where applications for miniaturization and temperature invariance are required as well as low cost and low power.

  8. Innovative nanostructures for highly sensitive vibrational biosensing (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Popp, Juergen; Mayerhöfer, Thomas; Cialla-May, Dana; Weber, Karina; Huebner, Uwe

    2016-03-01

    Employing vibrational spectroscopy (IR-absorption and Raman spectroscopy) allows for the labelfree detection of molecular specific fingerprints of inorganic, organic and biological substances. The sensitivity of vibrational spectroscopy can be improved by several orders of magnitude via the application of plasmonic active surfaces. Within this contribution we will discuss two such approaches, namely surface enhanced Raman spectroscopy (SERS) as well as surface enhanced IR absorption (SEIRA). It will be shown that SERS using metal colloids as SERS active substrate in combination with a microfluidic lab-on-a-chip (LOC) device enables high throughput and reproducible measurements with highest sensitivity and specificity. The application of such a LOC-SERS approach for therapeutic drug monitoring (e.g. quantitative detection of antibiotics in a urine matrix) will be presented. Furthermore, we will introduce innovative bottom-up strategies to prepare SERS-active nanostructures coated with a lipophilic sensor layer as one-time use SERS substrates for specific food analysis (e.g. quantitative detection of toxic food colorants). The second part of this contribution presents a slit array metamaterial perfect absorber for IR sensing applications consisting of a dielectric layer sandwiched between two metallic layers of which the upper layer is perforated with a periodic array of slits. Light-matter interaction is greatly amplified in the slits, where also the analyte is concentrated, as the surface of the substrate is covered by a thin silica layer. Thus, already small concentrations of analytes down to a monolayer can be detected by refractive index sensing and identified by their spectral fingerprints with a standard mid-infrared lab spectrometer.

  9. Graphene nanomesh as highly sensitive chemiresistor gas sensor

    PubMed Central

    Paul, Rajat Kanti; Badhulika, Sushmee; Saucedo, Nuvia M.; Mulchandani, Ashok

    2016-01-01

    Graphene is a one atom thick carbon allotrope with all surface atoms that has attracted significant attention as a promising material as the conduction channel of a field-effect transistor and chemical field-effect transistor sensors. However, the zero bandgap of semimetal graphene still limits its application for these devices. In this work, ethanol-chemical vapor deposition (CVD) grown p-type semiconducting large-area monolayer graphene film was patterned into nanomesh by the combination of nanosphere lithography and reactive ion etching and evaluated as field-effect transistor and chemiresistor gas sensors. The resulting neck-width of the synthesized nanomesh was about ~20 nm comprised of the gap between polystyrene spheres that was formed during the reactive ion etching process. The neck-width and the periodicities of the graphene nanomesh could be easily controlled depending the duration/power of RIE and the size of PS nanospheres. The fabricated GNM transistor device exhibited promising electronic properties featuring high drive current and ION/IOFF ratio of about 6, significantly higher than its film counterpart. Similarly, when applied as chemiresistor gas sensor at room temperature, the graphene nanomesh sensor showed excellent sensitivity towards NO2 and NH3, significantly higher than their film counterparts. The ethanol-based graphene nanomesh sensors exhibited sensitivities of about 4.32%/ppm in NO2 and 0.71%/ppm in NH3 with limit of detections of 15 ppb and 160 ppb, respectively. Our demonstrated studies on controlling the neck width of the nanomesh would lead to further improvement of graphene-based transistors and sensors. PMID:22931286

  10. High sensitivity dynamic spectral search for flare star radio

    NASA Technical Reports Server (NTRS)

    Abada-Simon, M.; Lecacheux, A.; Louarn, P.; Dulk, G. A.; Belkora, L.; Bookbinder, J. A.; Rosolen, C.

    1994-01-01

    We observed ten well-known flare stars with the Arcibo radio telescope at 1.4 GHz and 5 GHz, using a special observing technique to discriminate between real flares and radio freqeuncy interference. With a high sensitivity of 5.5 K/Jy at 1.4 GHz when averaged over a 50 MHz band, we are able to recognize flux enhancements as weak as approximately 6 mJy above the sky background variations. In about 85 hours of observation, about a dozen bursts were detected, only from AD Leo. All had flux densities lower than 70 mJy, which probably explains their lack of fine structures (except for the strongest one), such as were reported in the literature for stronger flares. Half of the bursts that we recorded are 100% circularly polarized, and half are not circularly polarized. Our results are a first attempt of reliable statistics on dMe flare rates at 1.4 GHz. The high brightness temperatures we infer for the observed bursts are interpreted in terms of coherent emission processes, either the cyclotron maser instability or plasma radiation. Efficiencies are comparable to those of solar or planetary radio emissions in the case of the cyclotron maser, and higher than the solar efficiency in the case of plasma radiation, with the caveat that there are great uncertainties in the coronal model and the source size.

  11. A batteryless temperature sensor based on high temperature sensitive material

    NASA Astrophysics Data System (ADS)

    Bakkali, Asma; Pelegri-Sebastia, José; Laghmich, Youssef; Lyhyaoui, Abdelouahid

    2016-05-01

    The major challenge in wireless sensor networks is the reduction of energy consumption. Passive wireless sensor network is an attractive solution for measuring physical parameters in harsh environment for large range of applications requiring sensing devices with low cost of fabrication, small size and long term measurement stability. Batteryless temperature sensing techniques are an active research field. The approach developed in our work holds a promising future for temperature sensor applications in order to successfully reduce the energy consumption. The temperature sensor presented in this paper is based on the electromagnetic transduction principle using the integration of the high temperature sensitive material into a passive structure. Variation in temperature makes the dielectric constant of this material changing, and such modification induces variation in the resonant frequencies of high-Q whispering-gallery modes (WGM) in the millimeter-wave frequency range. Following the results achieved, the proposed device shows a linear response to the increasing temperature and these variations can be remotely detected from a radar interrogation. Contribution to the topical issue "Materials for Energy Harvesting, Conversion and Storage (ICOME 2015) - Elected submissions", edited by Jean-Michel Nunzi, Rachid Bennacer and Mohammed El Ganaoui

  12. High sensitivity, low power, microfabricated electrochemical sensor for CO

    SciTech Connect

    Neuzil, P.; Kayvani, D.; Maclay, G.J.

    1996-12-31

    CO is a toxic byproduct of incomplete combustion. Improperly vented fireplaces and faulty furnaces cause a estimated 400 deaths in the US each year. The presence of high CO levels may also indicate the presence of a fire. Hence, improved CO detection is of great interest and in the last several years commercial CO detectors have been released. The two most common methods of CO detection in commercial systems for residential use are (1) optical colorometric method, and (2) tin oxide sensor. The colorometric method has the advantage of low power, but the devices tend to give an alarm condition when exposed to low CO levels for a long time period, are difficult to reset, and have a lifetime of about 1 year. The tin oxide sensors have limited stability and high power requirement since the sensor must be heated. There is a need for a stable, sensitive, low power, low cost CO sensor. The authors have developed a planar amperometric sensor for CO detection using microfabrication technology.

  13. Conducting polymer nanofibers for high sensitivity detection of chemical analytes.

    NASA Astrophysics Data System (ADS)

    Kumar, Abhishek; Leshchiner, Ignaty; Nagarajan, Subhalakshmi; Nagarajan, Ramaswamy; Kumar, Jayant

    2008-03-01

    Possessing large surface area materials is vital for high sensitivity detection of analyte. We report a novel, inexpensive and simple technique to make high surface area sensing interfaces using electrospinning. Conducting polymers (CP) nanotubes were made by electrospinning a solution of a catalyst (ferric tosylate) along with poly (lactic acid), which is an environment friendly biodegradable polymer. Further vapor deposition polymerization of the monomer ethylenedioxy thiophene (EDOT) on the nanofiber surface yielded poly (EDOT) covered fibers. X-ray photo electron spectroscopy (XPS) study reveals the presence of PEDOT predominantly on the surface of nanofibers. Conducting nanotubes had been received by dissolving the polymer in the fiber core. By a similar technique we had covalently incorporated fluorescent dyes on the nanofiber surface. The materials obtained show promise as efficient sensing elements. UV-Vis characterization confirms the formation of PEDOT nanotubes and incorporation of chromophores on the fiber surface. The morphological characterization was carried out using scanning electron microscopy (SEM) and transmission electron microscopy (TEM).

  14. Comparing standard Bonner spheres and high-sensitivity Bonner cylinders.

    PubMed

    Lee, Kuo-Wei; Yuan, Ming-Chen; Jiang, Shiang-Huei; Sheu, Rong-Jiun

    2014-10-01

    Standard Bonner spheres and proposed high-sensitivity Bonner cylinders were calibrated in a neutron calibration room, using a (252)Cf source. The Bonner sphere system consists of 11 polyethylene (PE) spheres of various diameters and 4 extended spheres that comprise embedded metal shells. Similar to the design of Bonner spheres, a set of Bonner cylinders was assembled using a large cylindrical (3)He tube as the central probe, which was wrapped using various thicknesses of PE. A layer of lead was employed inside one of the PE cylinders to increase the detection efficiency of high-energy neutrons. The central neutron probe used in the Bonner cylinders exhibited an efficiency of ∼17.9 times higher than that of the Bonner spheres. However, compared with the Bonner spheres, the Bonner cylinders are not fully symmetric in their geometry, exhibiting angular dependence in their responses to incoming neutrons. Using a series of calculations and measurements, this study presents a systematic comparison between Bonner spheres and cylinders in terms of their response functions, detection efficiencies, angular dependences and spectrum unfolding.

  15. Simple and sensitive determination of hydrazine in drinking water by ultra-high-performance liquid chromatography-tandem mass spectrometry after derivatization with naphthalene-2,3-dialdehyde.

    PubMed

    Oh, Jin-Aa; Shin, Ho-Sang

    2015-05-22

    An ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed to determine the level of hydrazine in drinking water. The method is based on the derivatization of hydrazine with naphthalene-2,3-dicarboxaldehyde (NDA) in water. The optimum conditions for UPLC-MS/MS detection were determined as follows: derivatization reagent dosage, 50mg/L of NDA; pH 2; and reaction time, 1min; room temperature. The formed derivative was injected into an LC system without extraction or purification procedures. Under the established conditions, the method was used to detect hydrazine in raw drinking water and chlorinated drinking water. The limits of detection and quantification for hydrazine in drinking water were 0.003μg/L and 0.01μg/L, respectively. The accuracy was in the range of 97-104%, and precision, expressed as relative standard deviation, was less than 9% in drinking water. Hydrazine was detected at a concentration of 0.13μg/L in one sample among 24 raw drinking water samples and in a range of 0.04-0.45μg/L in three samples among 24 chlorinated drinking water samples.

  16. Highly sensitive and multiplexed platforms for allergy diagnostics

    NASA Astrophysics Data System (ADS)

    Monroe, Margo R.

    Allergy is a disorder of the immune system caused by an immune response to otherwise harmless environmental allergens. Currently 20% of the US population is allergic and 90% of pediatric patients and 60% of adult patients with asthma have allergies. These percentages have increased by 18.5% in the past decade, with predicted similar trends for the future. Here we design sensitive, multiplexed platforms to detect allergen-specific IgE using the Interferometric Reflectance Imaging Sensor (IRIS) for various clinical settings. A microarray platform for allergy diagnosis allows for testing of specific IgE sensitivity to a multitude of allergens, while requiring only small volumes of patient blood sample. However, conventional fluorescent microarray technology is limited by i) the variation of probe immobilization, which hinders the ability to make quantitative, assertive, and statistically relevant conclusions necessary in immunodiagnostics and ii) the use of fluorophore labels, which is not suitable for some clinical applications due to the tendency of fluorophores to stick to blood particulates and require daily calibration methods. This calibrated fluorescence enhancement (CaFE) method integrates the low magnification modality of IRIS with enhanced fluorescence sensing in order to directly correlate immobilized probe (major allergens) density to allergen-specific IgE in patient serum. However, this platform only operates in processed serum samples, which is not ideal for point of care testing. Thus, a high magnification modality of IRIS was adapted as an alternative allergy diagnostic platform to automatically discriminate and size single nanoparticles bound to specific IgE in unprocessed, characterized human blood and serum samples. These features make IRIS an ideal candidate for clinical and diagnostic applications, such a POC testing. The high magnification (nanoparticle counting) modality in conjunction with low magnification of IRIS in a combined instrument

  17. ASIC for High Rate 3D Position Sensitive Detectors

    SciTech Connect

    Vernon, E.; De Geronimo, G.; Ackley, K.; Fried, J.; He, Z.; Herman, C.; Zhang, F.

    2010-06-16

    We report on the development of an application specific integrated circuit (ASIC) for 3D position sensitive detectors (3D PSD). The ASIC is designed to operate with pixelated wide bandgap sensors like Cadmium-Zinc-Telluride (CZT), Mercuric Iodide (Hgl2) and Thallium Bromide (TIBr). It measures the amplitudes and timings associated with an ionizing event on 128 anodes, the anode grid, and the cathode. Each channel provides low-noise charge amplification, high-order shaping with peaking time adjustable from 250 ns to 12 {micro}s, gain adjustable to 20 mV/fC or 120 mV/fC (for a dynamic range of 3.2 MeV and 530 keV in CZT), amplitude discrimination with 5-bit trimming, and positive and negative peak and timing detections. The readout can be full or sparse, based on a flag and single- or multi-cycle token passing. All channels, triggered channels only, or triggered with neighbors can be read out thus increasing the rate capability of the system to more than 10 kcps. The ASIC dissipates 330 mW which corresponds to about 2.5 mW per channel.

  18. Physical activity and high-sensitivity C-reactive protein.

    PubMed

    Plaisance, Eric P; Grandjean, Peter W

    2006-01-01

    Cardiovascular disease (CVD) remains one of the leading causes of death and disability in developed countries around the world despite the documented success of lifestyle and pharmacological interventions. This illustrates the multifactorial nature of atherosclerosis and the use of novel inflammatory markers as an adjunct to risk factor reduction strategies. As evidence continues to accumulate that inflammation is involved in all stages of the development and progression of atherosclerosis, markers of inflammation such as high-sensitivity C-reactive protein (CRP) may provide additional information regarding the biological status of the atherosclerotic lesion. Recent investigations suggest that physical activity reduces CRP levels. Higher levels of physical activity and cardiorespiratory fitness are consistently associated with 6-35% lower CRP levels. Longitudinal training studies that have demonstrated reductions in CRP concentrations range from 16% to 41%, an effect that may be independent of baseline levels of CRP, body composition or weight loss. The average change in CRP associated with physical activity appears to be at least as good, if not better, than currently prescribed pharmacological interventions in similar populations. The primary purpose of this review will be to present evidence from both cross-sectional and longitudinal investigations that physical activity lowers CRP levels in a dose-response manner. Finally, this review will examine factors such as body composition, sex, blood sample timing, diet and smoking, which may influence the CRP response to physical activity. PMID:16646631

  19. Improvement of sensitivity in high-resolution Rutherford backscattering spectroscopy

    SciTech Connect

    Hashimoto, H.; Nakajima, K.; Suzuki, M.; Kimura, K.; Sasakawa, K.

    2011-06-15

    The sensitivity (limit of detection) of high-resolution Rutherford backscattering spectroscopy (HRBS) is mainly determined by the background noise of the spectrometer. There are two major origins of the background noise in HRBS, one is the stray ions scattered from the inner wall of the vacuum chamber of the spectrometer and the other is the dark noise of the microchannel plate (MCP) detector which is commonly used as a focal plane detector of the spectrometer in HRBS. In order to reject the stray ions, several barriers are installed inside the spectrometer and a thin Mylar foil is mounted in front of the detector. The dark noise of the MCP detector is rejected by the coincidence measurement with the secondary electrons emitted from the Mylar foil upon the ion passage. After these improvements, the background noise is reduced by a factor of 200 at a maximum. The detection limit can be improved down to 10 ppm for As in Si at a measurement time of 1 h under ideal conditions.

  20. High sensitivity DNA detection based on regioselectively decorated electrocatalytic nanoparticles.

    PubMed

    Spain, Elaine; Brennan, Eoin; McArdle, Hazel; Keyes, Tia E; Forster, Robert J

    2012-08-01

    Self-assembled monolayers (SAMs) of dodecanethiol have been formed on gold electrodes to produce nanoscale defects. These defects define nucleation sites for the electrodeposition of mushroom shaped platinum nanoparticles (PtNPs). The top surfaces of these PtNPs have been selectively functionalized with single stranded probe DNA. These regioselectively modified particles were desorbed by applying a current jump to yield nanoparticles capable of biorecognition on the top curved side and efficient electrocatalysis on the nonfunctionalized lower surface. A second electrode was functionalized with single stranded capture DNA that has a sequence that is complementary to the pathogen, Staphylococcus aureus but leaves a section of the target available to bind the probe strand immobilized on the PtNPs. Following hybridization of the target and capture strands, the surface was exposed to the probe DNA labeled electrocatalytic PtNPs. Target binding was detected by monitoring the current associated with the reduction of hydrogen peroxide in a solution of 0.01 M H(2)SO(4). Calibration plots of the log[DNA] versus faradaic current were linear from 10 pM to 1 μM and picomolar concentrations could be detected without the need for amplification of the target, for example, using PCR or NASBA. As well as a wide dynamic range, this detection strategy has an excellent ability to discriminate DNA mismatches and a high analytical sensitivity. PMID:22747434

  1. Ultra-high sensitivity imaging of cancer using SERRS nanoparticles

    NASA Astrophysics Data System (ADS)

    Kircher, Moritz F.

    2016-05-01

    "Surface-enhanced Raman spectroscopy" (SERS) nanoparticles have gained much attention in recent years for in silico, in vitro and in vivo sensing applications. Our group has developed novel generations of biocompatible "surfaceenhanced resonance Raman spectroscopy" (SERRS) nanoparticles as novel molecular imaging agents. Via rigorous optimization of the different variables contributing to the Raman enhancement, we were able to design SERRS nanoparticles with so far unprecedented sensitivity of detection under in vivo imaging conditions (femto-attomolar range). This has resulted in our ability to visualize, with a single nanoparticle, many different cancer types (after intravenous injection) in mouse models. The cancer types we have tested so far include brain, breast, esophagus, stomach, pancreas, colon, sarcoma, and prostate cancer. All mouse models used are state-of-the-art and closely mimic the tumor biology in their human counterparts. In these animals, we were able to visualize not only the bulk tumors, but importantly also microscopic extensions and locoregional satellite metastases, thus delineating for the first time the true extent of tumor spread. Moreover, the particles enable the detection of premalignant lesions. Given their inert composition they are expected to have a high chance for clinical translation, where we envision them to have an impact in various scenarios ranging from early detection, image-guidance in open or minimally invasive surgical procedures, to noninvasive imaging in conjunction with spatially offset (SESORS) Raman detection devices.

  2. High resolution, position sensitive detector for energetic particle beams

    NASA Astrophysics Data System (ADS)

    Marsh, E. P.; Strathman, M. D.; Reed, D. A.; Morse, D. H.; Pontau, A. E.; Odom, R. W.

    1993-05-01

    The performance and design of an imaging position sensitive, particle beam detector will be presented. The detector is minimally invasive, operates over a wide dynamic range (> 10 10), and exhibits high spatial resolution. The secondary electrons produced when a particle beam passes through a thin foil are imaged using stigmatic ion optics onto a two-dimensional imaging detector. Due to the low scattering cross section of the 6 nm carbon foil the detector is a minimal perturbation on the primary beam. A prototype detector with an image resolution of approximately 5 μm for a field of view of 1 mm has been reported [R.W. Odom, M.D. Strathman, S.E. Buttrill, Jr., and S.M. Bauman, Nucl. Instr. and Meth. B44 (1990) 465]. A higher resolution detector for imaging small beams (< 50 μm) with an image resolution of better than 0.5 μm has since been developed and its design is presented.

  3. High sensitivity Moire interferometry with phase shifting at nano resolution

    NASA Astrophysics Data System (ADS)

    Chen, Bicheng

    Due to insatiate demand for miniaturization of electronics, there is a need for new techniques to measure full-field strain at micro-scale structures. In addition, Micro-Electronic-Mechanical-Systems (MEMS) require a high resolution and high sensitivity material property characterization technique. In this study, a theoretic model for a high sensitivity Moire Interferometry (MI) for measuring nano-scale strain field has been developed. The study also includes the application of the proposed measurement technique for the study of reliability of next generation nano-electronics/power electronics. The study includes both theoretical and experimental work. In the theoretical part, a far field modeling of a Moire Interferometer (MI) using the mode decomposition method is proposed according to the analytical formulation from the scalar diffraction theory. The wave propagation within the defined MI far field domain is solved analytically for a single frequency surface relieved grating structure following the Rayleigh-Sommerfeld formulation under the paraxial approximation. It is shown that the far-field electrical field and the intensity interferogram can be calculated using the mode decomposition method. Furthermore, the near-field (propagation distance < 1 mum) assumptions are validated using exact electromagnetic (EM) theory; and the EM fields are simulated in a few microns region above the surface of the diffraction grating. The study shows that there is a strong correlation (correlation factor R = 0.869) of spatial frequency response between EM field and strain field at the nanoscale. Experimentally, a 164 nm/pixel spatial resolution Moire Interferometer with automated full strain field calculation is proposed. Accurate full strain field maps are generated automatically by a combination of phase shifting technique (temporal data redundancy) and Continuous Wavelet Transform (CWT) (spatial data redundancy). A thermal experiment on BGA packaging is used to demonstrate

  4. High-sensitivity high-throughput chip based biosensor array for multiplexed detection of heavy metals

    NASA Astrophysics Data System (ADS)

    Yan, Hai; Tang, Naimei; Jairo, Grace A.; Chakravarty, Swapnajit; Blake, Diane A.; Chen, Ray T.

    2016-03-01

    Heavy metal ions released into the environment from industrial processes lead to various health hazards. We propose an on-chip label-free detection approach that allows high-sensitivity and high-throughput detection of heavy metals. The sensing device consists of 2-dimensional photonic crystal microcavities that are combined by multimode interferometer to form a sensor array. We experimentally demonstrate the detection of cadmium-chelate conjugate with concentration as low as 5 parts-per-billion (ppb).

  5. Proposed Ultra-High Sensitivity High-Frequency Gravitational Wave Detector

    NASA Astrophysics Data System (ADS)

    Baker, Robert M. L.; Stephenson, Gary V.; Li, Fangyu

    2008-01-01

    The paper discusses the proposed improvement of a High-Frequency Relic Gravitational Wave (HFRGW) detector designed by Li, Baker, Fang, Stephenson and Chen in order to greatly improve its sensitivity. The improved detector is inspired by the Laser Interferometer Gravitational Observatory or LIGO, but is sensitive to the high-frequency end of the gravitational-wave spectrum. As described in prior papers it utilizes the Gertsenshtein effect, which introduces the conversion of gravitational waves to electromagnetic (EM) waves in the presence of a static magnetic field. Such a conversion, if it leads to photons moving in a direction perpendicular to the plane of the EM waves and the magnetic field, will allow for ultra-high sensitivity HFRGW detection. The use of sensitive microwave, single photon detectors such as a circuit QED and/or the Rydberg Atom Cavity Detector, or off-the-shelf detectors, could lead to such detection. When the EM-detection photons are focused at the microwave detectors by fractal-membrane reflectors sensitivity is also improved. Noise sources external to the HFRGW detector will be eliminated by placing a tight mosaic of superconducting tiles (e.g., YBCO) and/or fractal membranes on the interior surface of the detector's cryogenic containment vessel in order to provide a perfect Faraday cage. Internal thermal noise will be eliminated by means of a microwave absorbing (or reflecting) interior enclosure shaped to conform to a high-intensity continuous microwave Gaussian beam (GB), will reduce any background photon flux (BPF) noise radiated normal to the GB's axis. Such BPF will be further attenuated by a series of microwave absorbing baffles forming tunnels to the sensitive microwave detectors on each side of the GB and at right angles to the static magnetic field. A HFGW detector of bandwidth of 1 KHz to 10 KHz or less in the GHz band has been selected. It is concluded that the utilization of the new ultra-high-sensitivity microwave detectors

  6. Stochastic sensitivity measure for mistuned high-performance turbines

    NASA Technical Reports Server (NTRS)

    Murthy, Durbha V.; Pierre, Christophe

    1992-01-01

    A stochastic measure of sensitivity is developed in order to predict the effects of small random blade mistuning on the dynamic aeroelastic response of turbomachinery blade assemblies. This sensitivity measure is based solely on the nominal system design (i.e., on tuned system information), which makes it extremely easy and inexpensive to calculate. The measure has the potential to become a valuable design tool that will enable designers to evaluate mistuning effects at a preliminary design stage and thus assess the need for a full mistuned rotor analysis. The predictive capability of the sensitivity measure is illustrated by examining the effects of mistuning on the aeroelastic modes of the first stage of the oxidizer turbopump in the Space Shuttle Main Engine. Results from a full analysis mistuned systems confirm that the simple stochastic sensitivity measure predicts consistently the drastic changes due to misturning and the localization of aeroelastic vibration to a few blades.

  7. High angular sensitivity thin film tin oxide sensor

    NASA Astrophysics Data System (ADS)

    Kaur, Davinder; Madaan, Divya; Sharma, V. K.; Kapoor, A.

    2016-05-01

    We present theoretical anlaysis of a thin film SnO2 (Tin Oxide) sensor for the measurement of variation in the refractive index of the bulk media. It is based on lossy mode resonance between the absorbing thin film lossy modes and the evanescent wave. Also the addition of low index dielectric matching layer between the prism and the lossy waveguiding layer future increase the angular sensitivity and produce an efficient refractive index sensor. The angular interrogation is done and obtained sensitivity is 110 degree/RIU. Theoretical analysis of the proposed sensor based on Fresnel reflection coefficients is presented. This enhanced sensitivity will further improve the monitoring of biomolecular interactions and the higher sensitivity of the proposed configurations makes it to be a much better option to be employed for biosensing applications.

  8. Design of a High Sensitivity GNSS receiver for Lunar missions

    NASA Astrophysics Data System (ADS)

    Musumeci, Luciano; Dovis, Fabio; Silva, João S.; da Silva, Pedro F.; Lopes, Hugo D.

    2016-06-01

    This paper presents the design of a satellite navigation receiver architecture tailored for future Lunar exploration missions, demonstrating the feasibility of using Global Navigation Satellite Systems signals integrated with an orbital filter to achieve such a scope. It analyzes the performance of a navigation solution based on pseudorange and pseudorange rate measurements, generated through the processing of very weak signals of the Global Positioning System (GPS) L1/L5 and Galileo E1/E5 frequency bands. In critical scenarios (e.g. during manoeuvres) acceleration and attitude measurements from additional sensors complementing the GNSS measurements are integrated with the GNSS measurement to match the positioning requirement. A review of environment characteristics (dynamics, geometry and signal power) for the different phases of a reference Lunar mission is provided, focusing on the stringent requirements of the Descent, Approach and Hazard Detection and Avoidance phase. The design of High Sensitivity acquisition and tracking schemes is supported by an extensive simulation test campaign using a software receiver implementation and navigation results are validated by means of an end-to-end software simulator. Acquisition and tracking of GPS and Galileo signals of the L1/E1 and L5/E5a bands was successfully demonstrated for Carrier-to-Noise density ratios as low as 5-8 dB-Hz. The proposed navigation architecture provides acceptable performances during the considered critical phases, granting position and velocity errors below 61.4 m and 3.2 m/s, respectively, for the 99.7% of the mission time.

  9. Highly sensitive and unbiased approach for elucidating antibody repertoires.

    PubMed

    Lin, Sherry G; Ba, Zhaoqing; Du, Zhou; Zhang, Yu; Hu, Jiazhi; Alt, Frederick W

    2016-07-12

    Developing B lymphocytes undergo V(D)J recombination to assemble germ-line V, D, and J gene segments into exons that encode the antigen-binding variable region of Ig heavy (H) and light (L) chains. IgH and IgL chains associate to form the B-cell receptor (BCR), which, upon antigen binding, activates B cells to secrete BCR as an antibody. Each of the huge number of clonally independent B cells expresses a unique set of IgH and IgL variable regions. The ability of V(D)J recombination to generate vast primary B-cell repertoires results from a combinatorial assortment of large numbers of different V, D, and J segments, coupled with diversification of the junctions between them to generate the complementary determining region 3 (CDR3) for antigen contact. Approaches to evaluate in depth the content of primary antibody repertoires and, ultimately, to study how they are further molded by secondary mutation and affinity maturation processes are of great importance to the B-cell development, vaccine, and antibody fields. We now describe an unbiased, sensitive, and readily accessible assay, referred to as high-throughput genome-wide translocation sequencing-adapted repertoire sequencing (HTGTS-Rep-seq), to quantify antibody repertoires. HTGTS-Rep-seq quantitatively identifies the vast majority of IgH and IgL V(D)J exons, including their unique CDR3 sequences, from progenitor and mature mouse B lineage cells via the use of specific J primers. HTGTS-Rep-seq also accurately quantifies DJH intermediates and V(D)J exons in either productive or nonproductive configurations. HTGTS-Rep-seq should be useful for studies of human samples, including clonal B-cell expansions, and also for following antibody affinity maturation processes. PMID:27354528

  10. High-resolution, high-sensitivity NMR of nanolitre anisotropic samples by coil spinning.

    PubMed

    Sakellariou, D; Le Goff, G; Jacquinot, J-F

    2007-06-01

    Nuclear magnetic resonance (NMR) can probe the local structure and dynamic properties of liquids and solids, making it one of the most powerful and versatile analytical methods available today. However, its intrinsically low sensitivity precludes NMR analysis of very small samples-as frequently used when studying isotopically labelled biological molecules or advanced materials, or as preferred when conducting high-throughput screening of biological samples or 'lab-on-a-chip' studies. The sensitivity of NMR has been improved by using static micro-coils, alternative detection schemes and pre-polarization approaches. But these strategies cannot be easily used in NMR experiments involving the fast sample spinning essential for obtaining well-resolved spectra from non-liquid samples. Here we demonstrate that inductive coupling allows wireless transmission of radio-frequency pulses and the reception of NMR signals under fast spinning of both detector coil and sample. This enables NMR measurements characterized by an optimal filling factor, very high radio-frequency field amplitudes and enhanced sensitivity that increases with decreasing sample volume. Signals obtained for nanolitre-sized samples of organic powders and biological tissue increase by almost one order of magnitude (or, equivalently, are acquired two orders of magnitude faster), compared to standard NMR measurements. Our approach also offers optimal sensitivity when studying samples that need to be confined inside multiple safety barriers, such as radioactive materials. In principle, the co-rotation of a micrometre-sized detector coil with the sample and the use of inductive coupling (techniques that are at the heart of our method) should enable highly sensitive NMR measurements on any mass-limited sample that requires fast mechanical rotation to obtain well-resolved spectra. The method is easy to implement on a commercial NMR set-up and exhibits improved performance with miniaturization, and we accordingly

  11. Novel Ruthenium Sensitizers with a Phenothiazine Conjugated Bipyridyl Ligand for High-Efficiency Dye-Sensitized Solar Cells.

    PubMed

    She, Zhijie; Cheng, Yangyang; Zhang, Luoqiang; Li, Xiaoyu; Wu, Di; Guo, Qiang; Lan, Jingbo; Wang, Ruilin; You, Jingsong

    2015-12-23

    Two efficient ruthenium sensitizers with a phenothiazine-modified bipyridine as an ancillary ligand, coded SCZ-1 and SCZ-2, have been developed as dyes in dye-sensitized solar cells (DSSCs). Both sensitizers exhibit low-energy metal-to-ligand charge transfer (MLCT) bands centered at 539 nm with high molar extinction coefficients of 1.77 × 10(4) M(-1) cm(-1) for SCZ-1 and 1.66 × 10(4) M(-1) cm(-1) for SCZ-2, which are significantly higher than the corresponding value for the reference N719 (1.27 × 10(4) M(-1) cm(-1)), indicating that the light-harvesting capacity of ruthenium sensitizers can be reinforced by introducing phenothiazine moieties into the bipyridine ligand. Under AM 1.5G irradiation (100 mW cm(-2)), SCZ-1 and SCZ-2 sensitized DSSC devices show impressive power conversion efficiencies (PCE) up to 10.4% by using of iodide-based electrolytes, which exceeds that of N719 (9.9%) under the same conditions. Both of the open circuit voltage (VOC) and fill factor (FF) of SCZ-sensitized solar cells approximate to those of N719-sensitized cell. The relatively higher efficiencies of the SCZ-sensitized cells than that of N719-sensitized cell come from their higher short-circuit photocurrent density (JSC), which may be mainly attributed to the high absorption coefficient. The absorption spectrum and device efficiency of SCZ-1 are both quite close to those of SCZ-2, suggesting that the difference in alkyl chains on the N atom of phenothiazine is not a decisive factor in affecting the photovoltaic performance of dyes. PMID:26624527

  12. Highly sensitive flexible pressure sensors with microstructured rubber dielectric layers

    NASA Astrophysics Data System (ADS)

    Mannsfeld, Stefan C. B.; Tee, Benjamin C.-K.; Stoltenberg, Randall M.; Chen, Christopher V. H.-H.; Barman, Soumendra; Muir, Beinn V. O.; Sokolov, Anatoliy N.; Reese, Colin; Bao, Zhenan

    2010-10-01

    The development of an electronic skin is critical to the realization of artificial intelligence that comes into direct contact with humans, and to biomedical applications such as prosthetic skin. To mimic the tactile sensing properties of natural skin, large arrays of pixel pressure sensors on a flexible and stretchable substrate are required. We demonstrate flexible, capacitive pressure sensors with unprecedented sensitivity and very short response times that can be inexpensively fabricated over large areas by microstructuring of thin films of the biocompatible elastomer polydimethylsiloxane. The pressure sensitivity of the microstructured films far surpassed that exhibited by unstructured elastomeric films of similar thickness, and is tunable by using different microstructures. The microstructured films were integrated into organic field-effect transistors as the dielectric layer, forming a new type of active sensor device with similarly excellent sensitivity and response times.

  13. High Sensitivity SPECT for Small Animals and Plants

    SciTech Connect

    Mitchell, Gregory S.

    2015-02-28

    Imaging systems using single gamma-ray emitting radioisotopes typically implement collimators in order to form the images. However, a tradeoff in sensitivity is inherent in the use of collimators, and modern preclinical single-photon emission computed tomography (SPECT) systems detect a very small fraction of emitted gamma-rays (<0.3%). We have built a collimator-less system, which can reach sensitivity of 40% for 99mTc imaging, while still producing images of sufficient spatial resolution for certain applications in thin objects such as mice, small plants, and well plates used for in vitro experiments.

  14. A high-sensitivity push-pull magnetometer

    SciTech Connect

    Breschi, E.; Grujić, Z. D.; Knowles, P.; Weis, A.

    2014-01-13

    We describe our approach to atomic magnetometry based on the push-pull optical pumping technique. Cesium vapor is pumped and probed by a resonant laser beam whose circular polarization is modulated synchronously with the spin evolution dynamics induced by a static magnetic field. The magnetometer is operated in a phase-locked loop, and it has an intrinsic sensitivity below 20fT/√(Hz), using a room temperature paraffin-coated cell. We use the magnetometer to monitor magnetic field fluctuations with a sensitivity of 300fT/√(Hz)

  15. A high-sensitivity push-pull magnetometer

    NASA Astrophysics Data System (ADS)

    Breschi, E.; Grujić, Z. D.; Knowles, P.; Weis, A.

    2014-01-01

    We describe our approach to atomic magnetometry based on the push-pull optical pumping technique. Cesium vapor is pumped and probed by a resonant laser beam whose circular polarization is modulated synchronously with the spin evolution dynamics induced by a static magnetic field. The magnetometer is operated in a phase-locked loop, and it has an intrinsic sensitivity below 20fT/√Hz , using a room temperature paraffin-coated cell. We use the magnetometer to monitor magnetic field fluctuations with a sensitivity of 300fT/√Hz .

  16. Development of High Temperature/High Sensitivity Novel Chemical Resistive Sensor

    SciTech Connect

    Chen, Chonglin; Nash, Patrick; Ma, Chunrui; Enriquez, Erik; Wang, Haibing; Xu, Xing; Bao, Shangyong; Collins, Gregory

    2013-08-13

    The research has been focused to design, fabricate, and develop high temperature/high sensitivity novel multifunctional chemical sensors for the selective detection of fossil energy gases used in power and fuel systems. By systematically studying the physical properties of the LnBaCo{sub 2}O{sub 5+d} (LBCO) [Ln=Pr or La] thin-films, a new concept chemical sensor based high temperature chemical resistant change has been developed for the application for the next generation highly efficient and near zero emission power generation technologies. We also discovered that the superfast chemical dynamic behavior and an ultrafast surface exchange kinetics in the highly epitaxial LBCO thin films. Furthermore, our research indicates that hydrogen can superfast diffuse in the ordered oxygen vacancy structures in the highly epitaxial LBCO thin films, which suggest that the LBCO thin film not only can be an excellent candidate for the fabrication of high temperature ultra sensitive chemical sensors and control systems for power and fuel monitoring systems, but also can be an excellent candidate for the low temperature solid oxide fuel cell anode and cathode materials.

  17. Sensitive, high-strain, high-rate bodily motion sensors based on graphene-rubber composites.

    PubMed

    Boland, Conor S; Khan, Umar; Backes, Claudia; O'Neill, Arlene; McCauley, Joe; Duane, Shane; Shanker, Ravi; Liu, Yang; Jurewicz, Izabela; Dalton, Alan B; Coleman, Jonathan N

    2014-09-23

    Monitoring of human bodily motion requires wearable sensors that can detect position, velocity and acceleration. They should be cheap, lightweight, mechanically compliant and display reasonable sensitivity at high strains and strain rates. No reported material has simultaneously demonstrated all the above requirements. Here we describe a simple method to infuse liquid-exfoliated graphene into natural rubber to create conducting composites. These materials are excellent strain sensors displaying 10(4)-fold increases in resistance and working at strains exceeding 800%. The sensitivity is reasonably high, with gauge factors of up to 35 observed. More importantly, these sensors can effectively track dynamic strain, working well at vibration frequencies of at least 160 Hz. At 60 Hz, we could monitor strains of at least 6% at strain rates exceeding 6000%/s. We have used these composites as bodily motion sensors, effectively monitoring joint and muscle motion as well and breathing and pulse.

  18. NanoUPLC-MS(E) proteomic analysis of osteoclastogenesis downregulation by IL-4.

    PubMed

    Freire, Mirna S; Cantuária, Ana Paula C; Lima, Stella M F; Almeida, Jeeser A; Murad, André M; Franco, Octavio L; Rezende, Taia M B

    2016-01-10

    Bone resorption is an important factor in bone homeostasis and imbalance can cause several diseases. In osteoimmunology, IL-4 has been described as an important factor in promoting M2 macrophage profile. In order to shed some light on the effect of IL-4 on osteoclast precursors in the presence of RANKL, cytokines and nitric oxide (NO) production and the proteomic profile were analyzed. The presence of IL-4 in in vitro osteoclastogenesis provides production of TNF-α, IL-1α, IL-1β, IL-10 and IL-12 at basal cell levels. Regarding NO production, IL-4 was sufficient to increase the basal NO levels. Proteomic analyses identified 877 global proteins. IL-4 in in vitro RANKL-mediated osteoclastogenesis leads to the expression of 118 proteins. The presence of rIL-4 in in vitro rRANKL-mediated-osteoclastogenesis downregulated this process. However, the proteomics findings in the osteoclastogenesis demonstrated a much greater effect on osteoclast precursor cells than on RANKL-differentiated osteoclasts. These results suggest that the main effect of IL-4 in pre-osteoclast cells leads to a M2 macrophage activation, and this probably contributed to a reduction in osteoclastogenesis when both stimuli were used. This study noticed that IL-4 plays an important regulatory role in bone homeostasis due to its suppressive potential of precursor osteoclast cells.

  19. UPLC-MS as a powerful technique for screening the nonvolatile contaminants in recycled PET.

    PubMed

    Bentayeb, K; Batlle, R; Romero, J; Nerín, C

    2007-07-01

    The possibility of using recycled polyethylene terephthalate as a food contact material is being seriously considered, but the potential migration of nonvolatile compounds from it must be assessed to ensure that it is safe to do so. In the study presented here, four samples of recycled PET were each exposed to three food simulants under the harsh extraction conditions stipulated by European legislation regarding migration tests. The nonvolatile compounds that migrated from them were determined by ultra performance liquid chromatography-mass spectrometry using three different cone voltages, and both positive and negative ionization modes. A total of 36 chemical compounds were detected, some of which were identified, including common additives such as N,N'-di-beta-naphthyl-p-phenylenediamine (antioxidant) and 2,4-di-tert-butyl-6-(5-chloro-2H-benzotriazol-2-yl)phenol (light stabilizer) as well as degradation compounds such as ethylene terephthalate dimers and trimers. In addition, specific migration values of three common components of polyethylene terephthalate (diethylene glycol, terephthalic acid, and isophthalic acid) were determined and found to occur at levels of <1 mg/kg-much lower than the specific migration limits stipulated by European legislation. PMID:17546445

  20. Rapid qualitative and quantitative analysis of proanthocyanidin oligomers and polymers by UPLC-MS/MS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proanthocyanidins (PAs) are a structurally complex and bioactive group of tannins. Detailed analysis of PA concentration, composition, and structure typically requires the use of one or more time-consuming analytical methods. For example, the commonly employed thiolysis and phloroglucinolysis method...

  1. High-speed high-sensitivity infrared spectroscopy using mid-infrared swept lasers (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Childs, David T. D.; Groom, Kristian M.; Hogg, Richard A.; Revin, Dmitry G.; Cockburn, John W.; Rehman, Ihtesham U.; Matcher, Stephen J.

    2016-03-01

    Infrared spectroscopy is a highly attractive read-out technology for compositional analysis of biomedical specimens because of its unique combination of high molecular sensitivity without the need for exogenous labels. Traditional techniques such as FTIR and Raman have suffered from comparatively low speed and sensitivity however recent innovations are challenging this situation. Direct mid-IR spectroscopy is being speeded up by innovations such as MEMS-based FTIR instruments with very high mirror speeds and supercontinuum sources producing very high sample irradiation levels. Here we explore another possible method - external cavity quantum cascade lasers (EC-QCL's) with high cavity tuning speeds (mid-IR swept lasers). Swept lasers have been heavily developed in the near-infrared where they are used for non-destructive low-coherence imaging (OCT). We adapt these concepts in two ways. Firstly by combining mid-IR quantum cascade gain chips with external cavity designs adapted from OCT we achieve spectral acquisition rates approaching 1 kHz and demonstrate potential to reach 100 kHz. Secondly we show that mid-IR swept lasers share a fundamental sensitivity advantage with near-IR OCT swept lasers. This makes them potentially able to achieve the same spectral SNR as an FTIR instrument in a time x N shorter (N being the number of spectral points) under otherwise matched conditions. This effect is demonstrated using measurements of a PDMS sample. The combination of potentially very high spectral acquisition rates, fundamental SNR advantage and the use of low-cost detector systems could make mid-IR swept lasers a powerful technology for high-throughput biomedical spectroscopy.

  2. Pajarito Monitor: a high-sensitivity monitoring system for highly enriched uranium

    SciTech Connect

    Fehlau, P.E.; Coop, K.; Garcia, C. Jr.; Martinez, J.

    1984-01-01

    The Pajarito Monitor for Special Nuclear Material is a high-sensitivity gamma-ray monitoring system for detecting small quantities of highly enriched uranium transported by pedestrians or motor vehicles. The monitor consists of two components: a walk-through personnel monitor and a vehicle monitor. The personnel monitor has a plastic-scintillator detector portal, a microwave occupancy monitor, and a microprocessor control unit that measures the radiation intensity during background and monitoring periods to detect transient diversion signals. The vehicle monitor examines stationary motor vehicles while the vehicle's occupants pass through the personnel portal to exchange their badges. The vehicle monitor has four groups of large plastic scintillators that scan the vehicle from above and below. Its microprocessor control unit measures separate radiation intensities in each detector group. Vehicle occupancy is sensed by a highway traffic detection system. Each monitor's controller is responsible for detecting diversion as well as serving as a calibration and trouble-shooting aid. Diversion signals are detected by a sequential probability ratio hypothesis test that minimizes the monitoring time in the vehicle monitor and adapts itself well to variations in individual passage speed in the personnel monitor. Designed to be highly sensitive to diverted enriched uranium, the monitoring system also exhibits exceptional sensitivity for plutonium. 6 references, 9 figures, 2 tables.

  3. Single nanobeam optical sensor with a high Q-factor and high sensitivity.

    PubMed

    Kim, Sejeong; Kim, Hwi-Min; Lee, Yong-Hee

    2015-11-15

    The miniaturization of optical sensors is essential for the realization of compact, portable, and cost-effective devices. Photonic crystal-based optical sensors, which have an ultra-small mode volume and footprint, have demonstrated remarkable recent progress in achieving a high figure-of-merit (FOM) in a sensor. Here, we report an optical sensor with a high Q-factor and high sensitivity based on a photonic crystal nanobeam using the second lowest air band-edge mode. We calculated that a nanobeam (n=3.4) in a water environment (n=1.33) has refractive-index sensitivity of ~631 nm/RIU, while the quality factor is greater than 23,300. Accordingly, a theoretical FOM of the sensor corresponds to >9500. To the best of our knowledge, experimental refractive-index sensitivity of 461 nm/RIU is the highest value among photonic crystal single nanobeam geometry. The simple geometry of uniform air hole sizes and lattice constants in the proposed nanobeam sensor allows easy fabrication and mechanical stability. PMID:26565872

  4. Improvement in the light sensitivity of the ultrahigh-speed high-sensitivity CCD with a microlens array

    NASA Astrophysics Data System (ADS)

    Hayashida, T.,; Yonai, J.; Kitamura, K.; Arai, T.; Kurita, T.; Tanioka, K.; Maruyama, H.; Etoh, T. Goji; Kitagawa, S.; Hatade, K.; Yamaguchi, T.; Takeuchi, H.; Iida, K.

    2008-02-01

    We are advancing the development of ultrahigh-speed, high-sensitivity CCDs for broadcast use that are capable of capturing smooth slow-motion videos in vivid colors even where lighting is limited, such as at professional baseball games played at night. We have already developed a 300,000 pixel, ultrahigh-speed CCD, and a single CCD color camera that has been used for sports broadcasts and science programs using this CCD. However, there are cases where even higher sensitivity is required, such as when using a telephoto lens during a baseball broadcast or a high-magnification microscope during science programs. This paper provides a summary of our experimental development aimed at further increasing the sensitivity of CCDs using the light-collecting effects of a microlens array.

  5. High-sensitivity and wide-directivity ultrasound detection using high Q polymer microring resonators

    PubMed Central

    Ling, Tao; Chen, Sung-Liang; Guo, L. Jay

    2011-01-01

    Small size ultrahigh Q polymer microrings working at near visible wavelength have been experimentally demonstrated as ultralow noise ultrasound detectors with wide directivity at high frequencies (>20 MHz). By combining a resist reflow and a low bias continuous etching and passivation process in mold fabrication, imprinted polymer microrings with drastically improved sidewall smoothness were obtained. An ultralow noise-equivalent pressure of 21.4 Pa over 1–75 MHz range has been achieved using a fabricated detector of 60 μm diameter. The device’s wide acceptance angle with high sensitivity considerably benefits ultrasound-related imaging. PMID:21673832

  6. Extremely high frequency sensitivity in a 'simple' ear.

    PubMed

    Moir, Hannah M; Jackson, Joseph C; Windmill, James F C

    2013-08-23

    An evolutionary war is being played out between the bat, which uses ultrasonic calls to locate insect prey, and the moth, which uses microscale ears to listen for the approaching bat. While the highest known frequency of bat echolocation calls is 212 kHz, the upper limit of moth hearing is considered much lower. Here, we show that the greater wax moth, Galleria mellonella, is capable of hearing ultrasonic frequencies approaching 300 kHz; the highest frequency sensitivity of any animal. With auditory frequency sensitivity that is unprecedented in the animal kingdom, the greater wax moth is ready and armed for any echolocation call adaptations made by the bat in the on-going bat-moth evolutionary war.

  7. Highly sensitive straightness measurement system using a ball-lens

    NASA Astrophysics Data System (ADS)

    Lee, Minho; Yang, Hyun-Ik; Cho, Nahm-Gyoo

    2016-01-01

    In this paper, a new and simple optical technique to accurately measure the straightness errors of a linear stage is proposed. To improve the performance, including the measurement sensitivity and resolution of the measurement system, and to simultaneously measure two-dimensional straightness errors (2D straightness errors), an optical system was designed using a laser, a retro-reflector, a ball-lens, and a two-dimensional position sensitive detector (2D PSD). The characteristics of the measurement system were analytically and experimentally investigated. A prototype measurement system was manufactured based on the investigated results, and the performances of this system have been tested. The measuring performance of the system was easily improved by about 12 times using the proposed technique and it can be further improved. It is shown that the proposed technique can easily and effectively improve the performance of a conventional straightness measurement system based on the geometric optical method using a PSD.

  8. Highly sensitive BTX detection using surface functionalized QCM sensor

    NASA Astrophysics Data System (ADS)

    Bozkurt, Asuman Aşıkoǧlu; Özdemir, Okan; Altındal, Ahmet

    2016-03-01

    A novel organic compound was designed and successfully synthesized for the fabrication of QCM based sensors to detect the low concentrations of BTX gases in indoor air. The effect of the long-range electron orbital delocalization on the BTX vapour sensing properties of azo-bridged Pcs based chemiresistor-type sensors have also been investigated in this work. The sensing behaviour of the film for the online detection of volatile organic solvent vapors was investigated by utilizing an AT-cut quartz crystal resonator. It was observed that the adsorption of the target molecules on the coating surface cause a reversible negative frequency shift of the resonator. Thus, a variety of solvent vapors can be detected by using the phthalocyanine film as sensitive coating, with sensitivity in the ppm range and response times in the order of several seconds depending on the molecular structure of the organic solvent.

  9. Low frequency, high sensitive tunable mechanical monolithic horizontal sensors

    NASA Astrophysics Data System (ADS)

    Acernese, Fausto; De Rosa, Rosario; Giordano, Gerardo; Romano, Rocco; Vilasi, Silvia; Barone, Fabrizio

    2011-04-01

    This paper describes an optimized version of the mechanical version of the monolithic tunable folded pendulum, developed at the University of Salerno, configurable both as seismometer and, in a force-feedback configuration, as accelerometer. Typical application of the sensors are in the field of geophysics, including the study of seismic and newtonian noise for characterization of suitable sites for underground interferometer for gravitational waves detection. The sensor, shaped with precision machining and electric-discharge-machining, like the previous version, is a very compact instrument, very sensitive in the low-frequency seismic noise band, with a very good immunity to environmental noises. Important characteristics are the tunability of the resonance frequency and the integrated laser optical readout, consisting of an optical lever and an interferometer. The theoretical sensitivity curves, largely improved due to a new design of the pendulum arms and of the electronics, are in a very good agreement with the measurements. The very large measurement band (10-6 +/- 10Hz) is couple to a very good sensitivity (10-12 m/√Hz in the band 0.1 +/- 10Hz), as seismometer. Prototypes of monolithic seismometers are already operational in selected sites around the world both to acquire seismic data for scientific analysis of seismic noise and to collect all the useful information to understand their performances in the very low frequency band (f < 1mHz). The results of the monolithic sensor as accelerometer (force feed-back configuration) are also presented and discussed. Particular relevance has their sensitivity that is better than 10-11 m/s2/√Hz in the band 0.1 +/- 10Hz. Finally, hypotheses are made on further developments and improvements of monolithic sensors.

  10. The strain-rate sensitivity of high-strength high-toughness steels.

    SciTech Connect

    Dilmore, M.F.; Crenshaw, Thomas B.; Boyce, Brad Lee

    2006-01-01

    The present study examines the strain-rate sensitivity of four high strength, high-toughness alloys at strain rates ranging from 0.0002 s-1 to 200 s-1: Aermet 100, a modified 4340, modified HP9-4-20, and a recently developed Eglin AFB steel alloy, ES-1c. A refined dynamic servohydraulic method was used to perform tensile tests over this entire range. Each of these alloys exhibit only modest strain-rate sensitivity. Specifically, the strain-rate sensitivity exponent m, is found to be in the range of 0.004-0.007 depending on the alloy. This corresponds to a {approx}10% increase in the yield strength over the 7-orders of magnitude change in strain-rate. Interestingly, while three of the alloys showed a concominant {approx}3-10% drop in their ductility with increasing strain-rate, the ES1-c alloy actually exhibited a 25% increase in ductility with increasing strain-rate. Fractography suggests the possibility that at higher strain-rates ES-1c evolves towards a more ductile dimple fracture mode associated with microvoid coalescence.

  11. High sensitivity gas sensor based on high-Q suspended polymer photonic crystal nanocavity

    SciTech Connect

    Clevenson, Hannah Desjardins, Pierre; Gan, Xuetao; Englund, Dirk

    2014-06-16

    We present high-sensitivity, multi-use optical gas sensors based on a one-dimensional photonic crystal cavity. These devices are implemented in versatile, flexible polymer materials which swell when in contact with a target gas, causing a measurable cavity length change. This change causes a shift in the cavity resonance, allowing precision measurements of gas concentration. We demonstrate suspended polymer nanocavity sensors and the recovery of sensors after the removal of stimulant gas from the system. With a measured quality factor exceeding 10{sup 4}, we show measurements of gas concentration as low as 600 parts per million (ppm) and an experimental sensitivity of 10 ppm; furthermore, we predict detection levels in the parts-per-billion range for a variety of gases.

  12. Analysis of Cyberbullying Sensitivity Levels of High School Students and Their Perceived Social Support Levels

    ERIC Educational Resources Information Center

    Akturk, Ahmet Oguz

    2015-01-01

    Purpose: The purpose of this paper is to determine the cyberbullying sensitivity levels of high school students and their perceived social supports levels, and analyze the variables that predict cyberbullying sensitivity. In addition, whether cyberbullying sensitivity levels and social support levels differed according to gender was also…

  13. Genetic influence on brain catecholamines: high brain norepinephrine in salt-sensitive rats

    SciTech Connect

    Iwai, J; Friedman, R; Tassinari, L

    1980-01-01

    Rats genetically sensitive to salt-induced hypertension evinced higher levels of plasma norepinephrine and epinephrine than rats genetically resistant to hypertension. The hypertension-sensitive rats showed higher hypothalamic norepinephrine and lower epinephrine than resistant rats. In response to a high salt diet, brain stem norepinephrine increased in sensitive rats while resistant rats exhibited a decrease on the same diet.

  14. High-performance and high-sensitivity applications of graphene transistors with self-assembled monolayers.

    PubMed

    Yeh, Chao-Hui; Kumar, Vinod; Moyano, David Ricardo; Wen, Shao-Hsuan; Parashar, Vyom; Hsiao, She-Hsin; Srivastava, Anchal; Saxena, Preeti S; Huang, Kun-Ping; Chang, Chien-Chung; Chiu, Po-Wen

    2016-03-15

    Charge impurities and polar molecules on the surface of dielectric substrates has long been a critical obstacle to using graphene for its niche applications that involve graphene's high mobility and high sensitivity nature. Self-assembled monolayers (SAMs) have been found to effectively reduce the impact of long-range scatterings induced by the external charges. Yet, demonstrations of scalable device applications using the SAMs technique remains missing due to the difficulties in the device fabrication arising from the strong surface tension of the modified dielectric environment. Here, we use patterned SAM arrays to build graphene electronic devices with transport channels confined on the modified areas. For high-mobility applications, both rigid and flexible radio-frequency graphene field-effect transistors (G-FETs) were demonstrated, with extrinsic cutoff frequency and maximum oscillation frequency enhanced by a factor of ~2 on SiO2/Si substrates. For high sensitivity applications, G-FETs were functionalized by monoclonal antibodies specific to cancer biomarker chondroitin sulfate proteoglycan 4, enabling its detection at a concentration of 0.01 fM, five orders of magnitude lower than that detectable by a conventional colorimetric assay. These devices can be very useful in the early diagnosis and monitoring of a malignant disease. PMID:26547427

  15. A low-power, high-sensitivity micromachined optical magnetometer

    NASA Astrophysics Data System (ADS)

    Mhaskar, R.; Knappe, S.; Kitching, J.

    2012-12-01

    We demonstrate an optical magnetometer based on a microfabricated 87Rb vapor cell in a micromachined silicon sensor head. The alkali atom density in the vapor cell is increased by heating the cell with light brought to the sensor through an optical fiber, and absorbed by colored filters attached to the cell windows. A second fiber-optically coupled beam optically pumps and interrogates the atoms. The magnetometer operates on 140 mW of heating power and achieves a sensitivity below 20 fT/√Hz throughout most of the frequency band from 15 Hz to 100 Hz. Such a sensor can measure magnetic fields from the human heart and brain.

  16. Advanced Cd(II) complexes as high efficiency co-sensitizers for enhanced dye-sensitized solar cell performance.

    PubMed

    Gao, Song; Fan, Rui Qing; Wang, Xin Ming; Qiang, Liang Sheng; Wei, Li Guo; Wang, Ping; Yang, Yu Lin; Wang, Yu Lei

    2015-11-01

    This work reports on two new complexes with the general formula [Cd3(IBA)3(Cl)2(HCOO)(H2O)]n (1) and {[Cd1.5(IBA)3(H2O)6]·3.5H2O}n (2), which can be synthesized by the reaction of Cd(II) with rigid linear ligand 4-HIBA containing imidazolyl and carboxylate functional groups [4-HIBA = 4-(1H-imidazol-1-yl)benzoic acid]. Single-crystal X-ray diffraction analyses indicate that complex 1 is a 2D "wave-like" layer structure constructed from trinuclear units and complex 2 is just a mononuclear structure. Surprisingly, both complexes 1 and 2 appear as a 3D supramolecular network via intermolecular hydrogen bonding interactions. What's more, due to their strong UV-visible absorption, 1 and 2 can be employed as co-sensitizers in combination with N719 to enhance dye-sensitized solar cell (DSSC) performance. Both of them could overcome the deficiency of the ruthenium complex N719 absorption in the region of ultraviolet and blue-violet, and the charge collection efficiency is also improved when 1 and 2 are used as co-sensitizers, which are all in favor of enhancing the performance. The DSSC devices using co-sensitizers of 1/N719 and 2/N719 show an overall conversion efficiency of 8.27% and 7.73% with a short circuit current density of 17.48 mA cm(-2) and 17.39 mA cm(-2), and an open circuit voltage of 0.75 V and 0.74 V, respectively. The overall conversion efficiency is 27.23% and 18.92% higher than that of a device solely sensitized by N719 (6.50%). Consequently, the prepared complexes are high efficiency co-sensitizers for enhancing the performance of N719 sensitized solar cells. PMID:26419745

  17. Sensitivity analysis for high accuracy proximity effect correction

    NASA Astrophysics Data System (ADS)

    Thrun, Xaver; Browning, Clyde; Choi, Kang-Hoon; Figueiro, Thiago; Hohle, Christoph; Saib, Mohamed; Schiavone, Patrick; Bartha, Johann W.

    2015-10-01

    A sensitivity analysis (SA) algorithm was developed and tested to comprehend the influences of different test pattern sets on the calibration of a point spread function (PSF) model with complementary approaches. Variance-based SA is the method of choice. It allows attributing the variance of the output of a model to the sum of variance of each input of the model and their correlated factors.1 The objective of this development is increasing the accuracy of the resolved PSF model in the complementary technique through the optimization of test pattern sets. Inscale® from Aselta Nanographics is used to prepare the various pattern sets and to check the consequences of development. Fraunhofer IPMS-CNT exposed the prepared data and observed those to visualize the link of sensitivities between the PSF parameters and the test pattern. First, the SA can assess the influence of test pattern sets for the determination of PSF parameters, such as which PSF parameter is affected on the employments of certain pattern. Secondly, throughout the evaluation, the SA enhances the precision of PSF through the optimization of test patterns. Finally, the developed algorithm is able to appraise what ranges of proximity effect correction is crucial on which portion of a real application pattern in the electron beam exposure.

  18. A protein multiplex microarray substrate with high sensitivity and specificity

    PubMed Central

    Fici, Dolores A.; McCormick, William; Brown, David W.; Herrmann, John E.; Kumar, Vikram; Awdeh, Zuheir L.

    2010-01-01

    The problems that have been associated with protein multiplex microarray immunoassay substrates and existing technology platforms include: binding, sensitivity, a low signal to noise ratio, target immobilization and the optimal simultaneous detection of diverse protein targets. Current commercial substrates for planar multiplex microarrays rely on protein attachment chemistries that range from covalent attachment to affinity ligand capture, to simple adsorption. In this pilot study, experimental performance parameters for direct monoclonal mouse IgG detection were compared for available two and three dimensional slide surface coatings with a new colloidal nitrocellulose substrate. New technology multiplex microarrays were also developed and evaluated for the detection of pathogen specific antibodies in human serum and the direct detection of enteric viral antigens. Data supports the nitrocellulose colloid as an effective reagent with the capacity to immobilize sufficient diverse protein target quantities for increased specificory signal without compromising authentic protein structure. The nitrocellulose colloid reagent is compatible with the array spotters and scanners routinely used for microarray preparation and processing. More importantly, as an alternate to fluorescence, colorimetric chemistries may be used for specific and sensitive protein target detection. The advantages of the nitrocellulose colloid platform indicate that this technology may be a valuable tool for the further development and expansion of multiplex microarray immunoassays in both the clinical and research laborat environment. PMID:20974147

  19. Highly Sensitive Immunochromatographic Identification of Tetracycline Antibiotics in Milk

    PubMed Central

    Taranova, N. A.; Kruhlik, A. S.; Zvereva, E. A.; Shmanai, V. V.; Vashkevich, I. I.; Semyonov, D. A.; Eremin, S. A.; Zherdev, A. V.; Dzantiev, B. B.

    2015-01-01

    A rapid immunochromatographic assay was developed for the control of tetracycline (TC). The assay is based on the competition between immobilized TC-protein conjugate and TC in a tested sample for binding with polyclonal anti-TC antibodies conjugated to colloidal gold during the flow of the sample along a membrane strip with immobilized reactants. Conjugation of colloidal gold and the total immunoglobulin (IgG) fraction of polyclonal antibodies was used to increase the assay sensitivity to ensure low content of specific antibodies in the conjugate. This allowed effective inhibition of free TC and conjugate binding in the strip test zone. Photometric marker registration allows control of the reduction of binding, thereby enhancing detection sensitivity. The proposed assay allows TC to be detected at concentrations up to 20 ng/mL, exceeding the limit of detection of the known analogues, in a wide working range (more than two orders) of 60 pg/mL to 10 ng/mL, ensured through the use of polyclonal antibodies. The assay time is 10 min. The efficiency of the designed assay is shown to identify TC in milk; the degree of recovery of TC ranges from 90 to 112%. The precision of the concentrations measurements was no more than 10%. PMID:26689537

  20. High precision, high sensitivity distributed displacement and temperature measurements using OFDR-based phase tracking

    NASA Astrophysics Data System (ADS)

    Gifford, Dawn K.; Froggatt, Mark E.; Kreger, Stephen T.

    2011-05-01

    Optical Frequency Domain Reflectometry is used to measure distributed displacement and temperature change with very high sensitivity and precision by measuring the phase change of an optical fiber sensor as a function of distance with high spatial resolution and accuracy. A fiber containing semi-continuous Bragg gratings was used as the sensor. The effective length change, or displacement, in the fiber caused by small temperature changes was measured as a function of distance with a precision of 2.4 nm and a spatial resolution of 1.5 mm. The temperature changes calculated from this displacement were measured with precision of 0.001 C with an effective sensor gauge length of 12 cm. These results demonstrate that the method employed of continuously tracking the phase change along the length of the fiber sensor enables high resolution distributed measurements that can be used to detect very small displacements, temperature changes, or strains.

  1. High temperature probe sensor with high sensitivity based on Michelson interferometer

    NASA Astrophysics Data System (ADS)

    Zhao, Na; Fu, Haiwei; Shao, Min; Yan, Xu; Li, Huidong; Liu, Qinpeng; Gao, Hong; Liu, Yinggang; Qiao, Xueguang

    2015-05-01

    A novel Michelson interferometer based on a bi-taper is achieved. Such a device is fabricated by splicing a section of thin core fiber (TCF) at one end of single-mode fiber (SMF). Due to the fiber bi-taper at the splicing point of SMF and TCF, the light is coupled into the fiber core and cladding from lead in fiber core. The light will be reflected at the end of the fiber and then will be recoupled back into the lead out fiber core by the fiber bi-taper. While the light returns back to the lead out fiber, the intermodal interference will occur for the optical path difference between core mode and cladding mode. A high temperature sensitivity of 0.140 nm/°C is achieved from 30 to 800 °C, and the linearity is 99.9%. The configuration features the advantages of easy fabrication, a compact size, high sensitivity, wide sensing range and high mechanical strength, making it a good candidate for distant temperature sensing and oil prospecting.

  2. Highly sensitive methods for electroanalytical chemistry based on nanotubule membranes.

    PubMed

    Kobayashi, Y; Martin, C R

    1999-09-01

    Two new methods of electroanalysis are described. These methods are based on membranes containing monodisperse Au nanotubules with inside diameters approaching molecular dimensions. In one method, the analyte species is detected by measuring the change in trans-membrane current when the analyte is added to the nanotubule-based cell. The second method entails the use of a concentration cell based on the nanotubule membrane. In this case, the change in membrane potential is used to detect the analyte. Detection limits as low as 10(-11) M have been achieved. Hence, these methods compete with even the most sensitive of modern analytical methodologies. In addition, excellent molecular-sized-based selectivity is observed.

  3. Development of highly sensitive sensor system for methane utilizing cataluminescence.

    PubMed

    Gong, Gu; Zhu, Hua

    2016-02-01

    A gaseous sensor system was developed for the detection of methane based on its cataluminescence emission. Cataluminescence characteristics and optimal conditions were studied in detail under optimized experimental conditions. Results showed that the methane cataluminescence sensor system could cover a linear detection range from 10 to 5800 ppm (R = 0.9963, n = 7) and the detection limit was about 7 ppm (S/N = 3), which was below the standard permitted concentration. Moreover, a linear discriminant analysis method was used to test the recognizable performance of the methane sensor. It was found that methane, ethane, propane and pentane could be distinguished clearly. Its methane sensing properties, including improved sensitivity, selectivity, stability and recognition demonstrated the TiO2/SnO2 materials to be promising candidates for constructing a cataluminescence-based gas sensor that could be used for detecting explosive gas contaminants.

  4. Genome-wide synteny through highly sensitive sequence alignment: Satsuma

    PubMed Central

    Grabherr, Manfred G.; Russell, Pamela; Meyer, Miriah; Mauceli, Evan; Alföldi, Jessica; Di Palma, Federica; Lindblad-Toh, Kerstin

    2010-01-01

    Motivation: Comparative genomics heavily relies on alignments of large and often complex DNA sequences. From an engineering perspective, the problem here is to provide maximum sensitivity (to find all there is to find), specificity (to only find real homology) and speed (to accommodate the billions of base pairs of vertebrate genomes). Results: Satsuma addresses all three issues through novel strategies: (i) cross-correlation, implemented via fast Fourier transform; (ii) a match scoring scheme that eliminates almost all false hits; and (iii) an asynchronous ‘battleship’-like search that allows for aligning two entire fish genomes (470 and 217 Mb) in 120 CPU hours using 15 processors on a single machine. Availability: Satsuma is part of the Spines software package, implemented in C++ on Linux. The latest version of Spines can be freely downloaded under the LGPL license from http://www.broadinstitute.org/science/programs/genome-biology/spines/ Contact: grabherr@broadinstitute.org PMID:20208069

  5. High sensitivity infrared 10.6 micrometer heterodyne receiver development

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The results are presented for a study on the design of an infrared 10.6-micrometer quantum-noise-limited optical receiver subsystem. Performance measurements of the HgCdTe photomixer preamplifier combination were carried out for photomixer temperatures up to 152 K and a photomixer frequency response of up to 420 MHz was obtained. Results of temperature and bias cycling of HgCdTe photomixers are reported. Design considerations for an operational 10.6 micrometer heterodyne receiver are presented. These consist of design data on required laser LO illumination, heat load levels for photomixer cooler, photomixer uniformity and the effects of photomixer impedance match on receiver sensitivity. Analysis and measurements of 10.6 micrometer heterodyne detection in an extrinsic photoconductive (p-type) HgCdTe photomixer are also presented.

  6. Highly sensitive humidity sensing properties of carbon quantum dots films

    SciTech Connect

    Zhang, Xing; Ming, Hai; Liu, Ruihua; Han, Xiao; Kang, Zhenhui; Liu, Yang; Zhang, Yonglai

    2013-02-15

    Graphical abstract: Display Omitted Highlights: ► A humidity sensing device was fabricated based on carbon quantum dots (CQDs) films. ► The conductivity of the CQDs films shows a linear and rapid response to atmosphere humidity. ► The humidity sensing property was due to the hydrogen bonds between the functional groups on CQDs. -- Abstract: We reported the fabrication of a humidity sensing device based on carbon quantum dots (CQDs) film. The conductivity of the CQDs film has a linear and rapid response to relative humidity, providing the opportunity for the fabrication of humidity sensing devices. The mechanism of our humidity sensor was proposed to be the formation of hydrogen bonds between carbon quantum dots and water molecules in the humidity environment, which significantly promote the electrons migration. In a control experiment, this hypothesis was confirmed by comparing the humidity sensitivity of candle soot (i.e. carbon nanoparticles) with and without oxygen containing groups on the surfaces.

  7. Novel Characteristics of Photodamage to PSII in a High-Light-Sensitive Symbiodinium Phylotype.

    PubMed

    Karim, Widiastuti; Seidi, Azadeh; Hill, Ross; Chow, Wah S; Minagawa, Jun; Hidaka, Michio; Takahashi, Shunichi

    2015-06-01

    Dinoflagellates from the genus Symbiodinium form symbiotic relationships with many marine invertebrates, including reef-building corals. Symbiodinium is genetically diverse, and acquiring suitable Symbiodinium phylotypes is crucial for the host to survive in habitat environments, such as high-light conditions. The sensitivity of Symbiodinium to high light differs among Symbiodinium phylotypes, but the mechanism that controls light sensitivity has not yet been fully resolved. In the present study using high-light-tolerant and -sensitive Symbiodinium phylotypes, we examined what determines sensitivity to high light. In growth experiments under different light intensities, Symbiodinium CS-164 (clade B1) and CCMP2459 (clade B2) were identified as high-light-tolerant and -sensitive phylotypes, respectively. Measurements of the maximum quantum yield of photosystem II (PSII) and the maximum photosynthetic oxygen production rate after high-light exposure demonstrated that CCMP2459 is more sensitive to photoinhibition of PSII than CS-164, and tends to lose maximum photosynthetic activity faster. Measurement of photodamage to PSII under light of different wavelength ranges demonstrated that PSII in both Symbiodinium phylotypes was significantly more sensitive to photodamage under shorter wavelength regions of light spectra (<470 nm). Importantly, PSII in CCMP2459, but not CS-164, was also sensitive to photodamage under the regions of light spectra around 470-550 and 630-710 nm, where photosynthetic antenna proteins of Symbiodinium have light absorption peaks. This finding indicates that the high-light-sensitive CCMP2459 has an extra component of photodamage to PSII, resulting in higher sensitivity to high light. Our results demonstrate that sensitivity of PSII to photodamage differs among Symbiodinium phylotypes and this determines their sensitivity to high light.

  8. Novel Characteristics of Photodamage to PSII in a High-Light-Sensitive Symbiodinium Phylotype.

    PubMed

    Karim, Widiastuti; Seidi, Azadeh; Hill, Ross; Chow, Wah S; Minagawa, Jun; Hidaka, Michio; Takahashi, Shunichi

    2015-06-01

    Dinoflagellates from the genus Symbiodinium form symbiotic relationships with many marine invertebrates, including reef-building corals. Symbiodinium is genetically diverse, and acquiring suitable Symbiodinium phylotypes is crucial for the host to survive in habitat environments, such as high-light conditions. The sensitivity of Symbiodinium to high light differs among Symbiodinium phylotypes, but the mechanism that controls light sensitivity has not yet been fully resolved. In the present study using high-light-tolerant and -sensitive Symbiodinium phylotypes, we examined what determines sensitivity to high light. In growth experiments under different light intensities, Symbiodinium CS-164 (clade B1) and CCMP2459 (clade B2) were identified as high-light-tolerant and -sensitive phylotypes, respectively. Measurements of the maximum quantum yield of photosystem II (PSII) and the maximum photosynthetic oxygen production rate after high-light exposure demonstrated that CCMP2459 is more sensitive to photoinhibition of PSII than CS-164, and tends to lose maximum photosynthetic activity faster. Measurement of photodamage to PSII under light of different wavelength ranges demonstrated that PSII in both Symbiodinium phylotypes was significantly more sensitive to photodamage under shorter wavelength regions of light spectra (<470 nm). Importantly, PSII in CCMP2459, but not CS-164, was also sensitive to photodamage under the regions of light spectra around 470-550 and 630-710 nm, where photosynthetic antenna proteins of Symbiodinium have light absorption peaks. This finding indicates that the high-light-sensitive CCMP2459 has an extra component of photodamage to PSII, resulting in higher sensitivity to high light. Our results demonstrate that sensitivity of PSII to photodamage differs among Symbiodinium phylotypes and this determines their sensitivity to high light. PMID:25759327

  9. High fat diet-fed obese rats are highly sensitive to doxorubicin-induced cardiotoxicity

    SciTech Connect

    Mitra, Mayurranjan S.; Donthamsetty, Shashikiran; White, Brent; Mehendale, Harihara M.

    2008-09-15

    Often, chemotherapy by doxorubicin (Adriamycin) is limited due to life threatening cardiotoxicity in patients during and posttherapy. Recently, we have shown that moderate diet restriction remarkably protects against doxorubicin-induced cardiotoxicity. This cardioprotection is accompanied by decreased cardiac oxidative stress and triglycerides and increased cardiac fatty-acid oxidation, ATP synthesis, and upregulated JAK/STAT3 pathway. In the current study, we investigated whether a physiological intervention by feeding 40% high fat diet (HFD), which induces obesity in male Sprague-Dawley rats (250-275 g), sensitizes to doxorubicin-induced cardiotoxicity. A LD{sub 10} dose (8 mg doxorubicin/kg, ip) administered on day 43 of the HFD feeding regimen led to higher cardiotoxicity, cardiac dysfunction, lipid peroxidation, and 80% mortality in the obese (OB) rats in the absence of any significant renal or hepatic toxicity. Doxorubicin toxicokinetics studies revealed no change in accumulation of doxorubicin and doxorubicinol (toxic metabolite) in the normal diet-fed (ND) and OB hearts. Mechanistic studies revealed that OB rats are sensitized due to: (1) higher oxyradical stress leading to upregulation of uncoupling proteins 2 and 3, (2) downregulation of cardiac peroxisome proliferators activated receptor-{alpha}, (3) decreased plasma adiponectin levels, (4) decreased cardiac fatty-acid oxidation (666.9 {+-} 14.0 nmol/min/g heart in ND versus 400.2 {+-} 11.8 nmol/min/g heart in OB), (5) decreased mitochondrial AMP-{alpha}2 protein kinase, and (6) 86% drop in cardiac ATP levels accompanied by decreased ATP/ADP ratio after doxorubicin administration. Decreased cardiac erythropoietin and increased SOCS3 further downregulated the cardioprotective JAK/STAT3 pathway. In conclusion, HFD-induced obese rats are highly sensitized to doxorubicin-induced cardiotoxicity by substantially downregulating cardiac mitochondrial ATP generation, increasing oxidative stress and downregulating

  10. Metallophthalocyanines as triplet sensitizers for highly efficient photon upconversion based on sensitized triplet-triplet annihilation.

    PubMed

    Han, J L; You, J; Yonemura, H; Yamada, S; Wang, S R; Li, X G

    2016-08-01

    Soluble palladium and platinum phthalocyanines with coumarin moieties were synthesized with Q bands in the red and near-IR regions, in which the molar extinction coefficients were up to 1.01 × 10(5) cm(-1) mol(-1). These metallophthalocyanines were coupled with rubrene and applied in photon upconversion systems based on triplet-triplet annihilation. The highest upconversion efficiency of the palladium phthalocyanine was 5.6%, which is higher than that of the platinum phthalocyanine-rubrene system. The larger molar extinction coefficient resulted in high upconversion capability (>10(5) cm(-1) mol(-1)) and low saturation incident power (<20 mW cm(-2)). PMID:27431880

  11. High-sensitivity in situ QCLAS-based ammonia concentration sensor for high-temperature applications

    NASA Astrophysics Data System (ADS)

    Peng, W. Y.; Sur, R.; Strand, C. L.; Spearrin, R. M.; Jeffries, J. B.; Hanson, R. K.

    2016-07-01

    A novel quantum cascade laser (QCL) absorption sensor is presented for high-sensitivity in situ measurements of ammonia (hbox {NH}_3) in high-temperature environments, using scanned wavelength modulation spectroscopy (WMS) with first-harmonic-normalized second-harmonic detection (scanned WMS-2 f/1 f) to neutralize the effect of non-absorption losses in the harsh environment. The sensor utilized the sQ(9,9) transition of the fundamental symmetric stretch band of hbox {NH}_3 at 10.39 {\\upmu }hbox {m} and was sinusoidally modulated at 10 kHz and scanned across the peak of the absorption feature at 50 Hz, leading to a detection bandwidth of 100 Hz. A novel technique was used to select an optimal WMS modulation depth parameter that reduced the sensor's sensitivity to spectral interference from hbox {H}_2hbox {O} and hbox {CO}_2 without significantly sacrificing signal-to-noise ratio. The sensor performance was validated by measuring known concentrations of hbox {NH}_3 in a flowing gas cell. The sensor was then demonstrated in a laboratory-scale methane-air burner seeded with hbox {NH}_3, achieving a demonstrated detection limit of 2.8 ± 0.26 ppm hbox {NH}_3 by mole at a path length of 179 cm, equivalence ratio of 0.6, pressure of 1 atm, and temperatures of up to 600 K.

  12. High sensitivity of northeastern broadleaf forest trees to water availability

    NASA Astrophysics Data System (ADS)

    Levesque, M.; Pederson, N.; Andreu-Hayles, L.

    2015-12-01

    Temperate deciduous forests of eastern US provide goods and services to millions of people and play a vital role in the terrestrial carbon and hydrological cycles. However, ongoing climate change and increased in CO2 concentration in the atmosphere (ca) are expected to alter growth and gas exchange of trees, and ultimately forest productivity. Still, the magnitude of these effects is unclear. A better comprehension of the species-specific responses to environmental changes will better inform models and managers on the vulnerability and resiliency of these forests. Tree-ring analysis was combined with δ¹³C and δ18O measurements to investigate growth and physiological responses of red oak (Quercus rubra L.) and tulip poplar (Liriodendron tulipifera L.) in northeastern US to changes in water availability and ca for the period 1950-2014. We found very strong correlations between summer climatic water balance (June-August) and isotopic tree-ring series for δ¹³C (r = -0.65 and -0.73), and δ18O (r = -0.59 and -0.70), for red oak and tulip poplar, respectively. In contrast, tree-ring width was less sensitive to summer water availability (r = 0.33-0.39). Prior to the mid 1980s, low water availability resulted in low stomatal conductance, photosynthesis, and growth. Since that period, pluvial conditions occurring in northeastern US have increased stomatal conductance, carbon uptake, and growth of both species. These findings demonstrate that broadleaf trees in this region could be more sensitive to drought than expected. This appears especially true since much of the calibration period looks wet in a multi-centennial perspective. Further, stronger spatial correlations were found between climate data with tree-ring isotopes than with tree-ring width and the geographical area of the observed δ18O-precipitation response (i.e. the area over which correlations are > 0.5) covers most of the northeastern US. Given the good fit between the isotopic time series and water

  13. Determination of deoxynivalenol in cereals by immunoaffinity clean-up and ultra-high performance liquid chromatography tandem mass spectrometry.

    PubMed

    Li, Yanshen; Wang, Zhanhui; De Saeger, Sarah; Shi, Weimin; Li, Cun; Zhang, Suxia; Cao, Xingyuan; Shen, Jianzhong

    2012-02-01

    An immunoaffinity column (IAC) was prepared with a new deoxynivalenol (DON) monoclonal antibody and used as a clean-up tool before ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) analysis of DON in cereals. The developed IAC clean-up method showed high recoveries for DON. They ranged from 61% to 103% in wheat, rice, and millet with intra-day and inter-day variations below 19% and 17%, respectively. The column capacity was 2.86μg DON per mL of gel, and it maintained above 0.68μg/mL of gel after 10 cycles of usage at 2 days intervals. The limit of detection (LOD) and limit of quantification (LOQ) were 0.3 and 0.8μg/kg, respectively. Twenty-one out of 40 analyzed commercial cereal samples were positive at DON concentrations from 7 to 534μg/kg.

  14. Missing Iron-Oxidizing Acidophiles Highly Sensitive to Organic Compounds

    PubMed Central

    Ueoka, Nagayoshi; Kouzuma, Atsushi; Watanabe, Kazuya

    2016-01-01

    The genus Acidithiobacillus includes iron-oxidizing lithoautotrophs that thrive in acidic mine environments. Acidithiobacillus ferrooxidans is a representative species and has been extensively studied for its application to the bioleaching of precious metals. In our attempts to cultivate the type strain of A. ferrooxidans (ATCC 23270T), repeated transfers to fresh inorganic media resulted in the emergence of cultures with improved growth traits. Strains were isolated from the resultant culture by forming colonies on inorganic silica-gel plates. A representative isolate (strain NU-1) was unable to form colonies on agarose plates and was more sensitive to organics, such as glucose, than the type strain of A. ferrooxidans. Strain NU-1 exhibited superior growth traits in inorganic iron media to those of other iron-oxidizing acidithiobacilli, suggesting its potential for industrial applications. A draft genome of NU-1 uncovered unique features in catabolic enzymes, indicating that this strain is not a mutant of the A. ferrooxidans type strain. Our results indicate that the use of inorganic silica-gel plates facilitates the isolation of as-yet-unexamined iron-oxidizing acidithiobacilli from environmental samples and enrichment cultures. PMID:27356527

  15. Highly sensitive homogenous chemiluminescence immunoassay using gold nanoparticles as label

    NASA Astrophysics Data System (ADS)

    Luo, Jing; Cui, Xiang; Liu, Wei; Li, Baoxin

    2014-10-01

    Homogeneous immunoassay is becoming more and more attractive for modern medical diagnosis because it is superior to heterogeneous immunoassay in sample and reagent consumption, analysis time, portability and disposability. Herein, a universal platform for homogeneous immunoassay, using human immunoglobulin G (IgG) as a model analyte, has been developed. This assay relies upon the catalytic activity of gold nanoparticles (AuNPs) on luminol-AgNO3 chemiluminescence (CL) reaction. The immunoreaction of antigen and antibody can induce the aggregation of antibody-functionalized AuNPs, and after aggregation the catalytic activity of AuNPs on luminol-AgNO3 CL reaction is greatly enhanced. Without any separation steps, a CL signal is generated upon addition of a trigger solution, and the CL intensity is directly correlated to the quantity of IgG. The detection limit of IgG was estimated to be as low as 3 pg/mL, and the sensitivity was better than that of the reported AuNPs-based CL immunoassay for IgG.

  16. Highly sensitive self-complementary DNA nanoswitches triggered by polyelectrolytes.

    PubMed

    Wu, Jincai; Yu, Feng; Zhang, Zheng; Chen, Yong; Du, Jie; Maruyama, Atsushi

    2016-01-01

    Dimerization of two homologous strands of genomic DNA/RNA is an essential feature of retroviral replication. Herein we show that a cationic comb-type copolymer (CCC), poly(L-lysine)-graft-dextran, accelerates the dimerization of self-complementary stem-loop DNA, frequently found in functional DNA/RNA molecules, such as aptamers. Furthermore, an anionic polymer poly(sodium vinylsulfonate) (PVS) dissociates CCC from the duplex shortly within a few seconds. Then single stem-loop DNA spontaneously transforms from its dimer. Thus we can easily control the dimer and stem-loop DNA by switching on/off CCC activity. Both polyelectrolytes and DNA concentrations are in the nanomole per liter range. The polyelectrolyte-assisted transconformation and sequences design strategy ensures the reversible state control with rapid response and effective switching under physiologically relevant conditions. A further application of this sensitive assembly is to construct an aptamer-type drug delivery system, bind or release functional molecules responding to its transconformation.

  17. High-sensitivity observations of solar flare decimeter radiation

    NASA Astrophysics Data System (ADS)

    Benz, A. O.; Messmer, P.; Monstein, C.

    2001-01-01

    A new acousto-optic radio spectrometer has observed the 1-2 GHz radio emission of solar flares with unprecedented sensitivity. The number of detected decimeter type III bursts is greatly enhanced compared to observations by conventional spectrometers observing only one frequency at the time. The observations indicate a large number of electron beams propagating in dense plasmas. For the first time, we report weak, reversed drifting type III bursts at frequencies above simultaneous narrowband decimeter spikes. The type III bursts are reliable signatures of electron beams propagating downward in the corona, apparently away from the source of the spikes. The observations contradict the most popular spike model that places the spike sources at the footpoints of loops. Conspicuous also was an apparent bidirectional type U burst forming a fish-like pattern. It occurs simultaneously with an intense U-burst at 600-370 MHz observed in Tremsdorf. We suggest that it intermodulated with strong terrestrial interference(cellular phones) causing a spurious symmetric pattern in the spectrogram at 1.4 GHz. Symmetric features in the 1-2 GHz range, some already reported in the literature, therefore must be considered with utmost caution.

  18. Highly sensitive self-complementary DNA nanoswitches triggered by polyelectrolytes

    NASA Astrophysics Data System (ADS)

    Wu, Jincai; Yu, Feng; Zhang, Zheng; Chen, Yong; Du, Jie; Maruyama, Atsushi

    2015-12-01

    Dimerization of two homologous strands of genomic DNA/RNA is an essential feature of retroviral replication. Herein we show that a cationic comb-type copolymer (CCC), poly(l-lysine)-graft-dextran, accelerates the dimerization of self-complementary stem-loop DNA, frequently found in functional DNA/RNA molecules, such as aptamers. Furthermore, an anionic polymer poly(sodium vinylsulfonate) (PVS) dissociates CCC from the duplex shortly within a few seconds. Then single stem-loop DNA spontaneously transforms from its dimer. Thus we can easily control the dimer and stem-loop DNA by switching on/off CCC activity. Both polyelectrolytes and DNA concentrations are in the nanomole per liter range. The polyelectrolyte-assisted transconformation and sequences design strategy ensures the reversible state control with rapid response and effective switching under physiologically relevant conditions. A further application of this sensitive assembly is to construct an aptamer-type drug delivery system, bind or release functional molecules responding to its transconformation.Dimerization of two homologous strands of genomic DNA/RNA is an essential feature of retroviral replication. Herein we show that a cationic comb-type copolymer (CCC), poly(l-lysine)-graft-dextran, accelerates the dimerization of self-complementary stem-loop DNA, frequently found in functional DNA/RNA molecules, such as aptamers. Furthermore, an anionic polymer poly(sodium vinylsulfonate) (PVS) dissociates CCC from the duplex shortly within a few seconds. Then single stem-loop DNA spontaneously transforms from its dimer. Thus we can easily control the dimer and stem-loop DNA by switching on/off CCC activity. Both polyelectrolytes and DNA concentrations are in the nanomole per liter range. The polyelectrolyte-assisted transconformation and sequences design strategy ensures the reversible state control with rapid response and effective switching under physiologically relevant conditions. A further application of

  19. Highly sensitive vacuum ion pump current measurement system

    DOEpatents

    Hansknecht, John Christopher

    2006-02-21

    A vacuum system comprising: 1) an ion pump; 2) power supply; 3) a high voltage DC--DC converter drawing power from the power supply and powering the vacuum pump; 4) a feedback network comprising an ammeter circuit including an operational amplifier and a series of relay controlled scaling resistors of different resistance for detecting circuit feedback; 5) an optional power block section intermediate the power supply and the high voltage DC--DC converter; and 6) a microprocessor receiving feedback information from the feedback network, controlling which of the scaling resistors should be in the circuit and manipulating data from the feedback network to provide accurate vacuum measurement to an operator.

  20. High-sensitivity mass spectrometry with a tandem accelerator

    SciTech Connect

    Henning, W.

    1983-01-01

    The characteristic features of accelerator mass spectrometry are discussed. A short overview is given of the current status of mass spectrometry with high-energy (MeV/nucleon) heavy-ion accelerators. Emphasis is placed on studies with tandem accelerators and on future mass spectrometry of heavier isotopes with the new generation of higher-voltage tandems.

  1. Highly sensitive amyloid detection enabled by thioflavin T dimers.

    PubMed

    Qin, Luoheng; Vastl, Julian; Gao, Jianmin

    2010-10-01

    Fluorescent molecules that specifically target amyloid structures are highly desirable for amyloid research. Herein, we show a dimeric design of thioflavin T improves its binding affinity to Abeta amyloid by up to 70 fold, while not sacrificing the specificity and the "light-up" feature upon amyloid binding.

  2. Variable high pressure processing sensitivities for GII human noroviruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Human norovirus (HuNoV) is the leading cause of foodborne diseases worldwide. High pressure processing (HPP) is one of the most promising non-thermal technologies for decontamination of viral pathogens in foods. However, the survival of HuNoVs by HPP is poorly understood because these viruses cann...

  3. Highly stable and sensitive glucose biosensor based on covalently assembled high density Au nanostructures.

    PubMed

    Si, Peng; Kannan, Palanisamy; Guo, Longhua; Son, Hungsun; Kim, Dong-Hwan

    2011-05-15

    We describe the development of a highly stable and sensitive glucose biosensor based on the nanohybrid materials derived from gold nanoparticles (AuNPs) and multi-walled carbon nanotubes (MWCNT). The biosensing platform was developed by using layer-by-layer (LBL) self-assembly of the nanohybrid materials and the enzyme glucose oxidase (GOx). A high density of AuNPs and MWCNT nanocomposite materials were constructed by alternate self assembly of thiol functionalized MWCNTs and AuNPs, followed by chemisoption of GOx. The surface morphology of multilayered AuNPs/MWCNT structure was characterized by field emission-scanning electron microscope (FE-SEM), and the surface coverage of AuNPs was investigated by cyclic voltammetry (CV), showing that 5 layers of assembly achieves the maximum particle density on electrode. The immobilization of GOx was monitored by electrochemical impedance spectroscopy (EIS). CV and amperometry methods were used to study the electrochemical oxidation of glucose at physiological pH 7.4. The Au electrode modified with five layers of AuNPs/MWCNT composites and GOx exhibited an excellent electrocatalytic activity towards oxidation of glucose, which presents a wide liner range from 20 μM to 10 mM, with a sensitivity of 19.27 μA mM(-1) cm(-2). The detection limit of present modified electrode was found to be 2.3 μM (S/N=3). In addition, the resulting biosensor showed a faster amperometric current response (within 3 s) and low apparent Michaelis-Menten constant (K(m)(app)). Our present study shows that the high density of AuNPs decorated MWCNT is a promising nanohybrid material for the construction of enzyme based electrochemical biosensors.

  4. Aptamer-Functionalized Fluorescent Silica Nanoparticles for Highly Sensitive Detection of Leukemia Cells

    NASA Astrophysics Data System (ADS)

    Tan, Juntao; Yang, Nuo; Hu, Zixi; Su, Jing; Zhong, Jianhong; Yang, Yang; Yu, Yating; Zhu, Jianmeng; Xue, Dabin; Huang, Yingying; Lai, Zongqiang; Huang, Yong; Lu, Xiaoling; Zhao, Yongxiang

    2016-06-01

    A simple, highly sensitive method to detect leukemia cells has been developed based on aptamer-modified fluorescent silica nanoparticles (FSNPs). In this strategy, the amine-labeled Sgc8 aptamer was conjugated to carboxyl-modified FSNPs via amide coupling between amino and carboxyl groups. Sensitivity and specificity of Sgc8-FSNPs were assessed using flow cytometry and fluorescence microscopy. These results showed that Sgc8-FSNPs detected leukemia cells with high sensitivity and specificity. Aptamer-modified FSNPs hold promise for sensitive and specific detection of leukemia cells. Changing the aptamer may allow the FSNPs to detect other types of cancer cells.

  5. Aptamer-Functionalized Fluorescent Silica Nanoparticles for Highly Sensitive Detection of Leukemia Cells.

    PubMed

    Tan, Juntao; Yang, Nuo; Hu, Zixi; Su, Jing; Zhong, Jianhong; Yang, Yang; Yu, Yating; Zhu, Jianmeng; Xue, Dabin; Huang, Yingying; Lai, Zongqiang; Huang, Yong; Lu, Xiaoling; Zhao, Yongxiang

    2016-12-01

    A simple, highly sensitive method to detect leukemia cells has been developed based on aptamer-modified fluorescent silica nanoparticles (FSNPs). In this strategy, the amine-labeled Sgc8 aptamer was conjugated to carboxyl-modified FSNPs via amide coupling between amino and carboxyl groups. Sensitivity and specificity of Sgc8-FSNPs were assessed using flow cytometry and fluorescence microscopy. These results showed that Sgc8-FSNPs detected leukemia cells with high sensitivity and specificity. Aptamer-modified FSNPs hold promise for sensitive and specific detection of leukemia cells. Changing the aptamer may allow the FSNPs to detect other types of cancer cells. PMID:27299653

  6. PCF Based Sensor with High Sensitivity, High Birefringence and Low Confinement Losses for Liquid Analyte Sensing Applications

    PubMed Central

    Ademgil, Huseyin; Haxha, Shyqyri

    2015-01-01

    In this paper, we report a design of high sensitivity Photonic Crystal Fiber (PCF) sensor with high birefringence and low confinement losses for liquid analyte sensing applications. The proposed PCF structures are designed with supplementary elliptical air holes in the core region vertically-shaped V-PCF and horizontally-shaped H-PCF. The full vectorial Finite Element Method (FEM) simulations performed to examine the sensitivity, the confinement losses, the effective refractive index and the modal birefringence features of the proposed elliptical air hole PCF structures. We show that the proposed PCF structures exhibit high relative sensitivity, high birefringence and low confinement losses simultaneously for various analytes. PMID:26694408

  7. PCF Based Sensor with High Sensitivity, High Birefringence and Low Confinement Losses for Liquid Analyte Sensing Applications.

    PubMed

    Ademgil, Huseyin; Haxha, Shyqyri

    2015-01-01

    In this paper, we report a design of high sensitivity Photonic Crystal Fiber (PCF) sensor with high birefringence and low confinement losses for liquid analyte sensing applications. The proposed PCF structures are designed with supplementary elliptical air holes in the core region vertically-shaped V-PCF and horizontally-shaped H-PCF. The full vectorial Finite Element Method (FEM) simulations performed to examine the sensitivity, the confinement losses, the effective refractive index and the modal birefringence features of the proposed elliptical air hole PCF structures. We show that the proposed PCF structures exhibit high relative sensitivity, high birefringence and low confinement losses simultaneously for various analytes. PMID:26694408

  8. The highly sensitive brain: an fMRI study of sensory processing sensitivity and response to others' emotions

    PubMed Central

    Acevedo, Bianca P; Aron, Elaine N; Aron, Arthur; Sangster, Matthew-Donald; Collins, Nancy; Brown, Lucy L

    2014-01-01

    Background Theory and research suggest that sensory processing sensitivity (SPS), found in roughly 20% of humans and over 100 other species, is a trait associated with greater sensitivity and responsiveness to the environment and to social stimuli. Self-report studies have shown that high-SPS individuals are strongly affected by others' moods, but no previous study has examined neural systems engaged in response to others' emotions. Methods This study examined the neural correlates of SPS (measured by the standard short-form Highly Sensitive Person [HSP] scale) among 18 participants (10 females) while viewing photos of their romantic partners and of strangers displaying positive, negative, or neutral facial expressions. One year apart, 13 of the 18 participants were scanned twice. Results Across all conditions, HSP scores were associated with increased brain activation of regions involved in attention and action planning (in the cingulate and premotor area [PMA]). For happy and sad photo conditions, SPS was associated with activation of brain regions involved in awareness, integration of sensory information, empathy, and action planning (e.g., cingulate, insula, inferior frontal gyrus [IFG], middle temporal gyrus [MTG], and PMA). Conclusions As predicted, for partner images and for happy facial photos, HSP scores were associated with stronger activation of brain regions involved in awareness, empathy, and self-other processing. These results provide evidence that awareness and responsiveness are fundamental features of SPS, and show how the brain may mediate these traits. PMID:25161824

  9. Dynamics and sensitivity analysis of high-frequency conduction block

    NASA Astrophysics Data System (ADS)

    Ackermann, D. Michael; Bhadra, Niloy; Gerges, Meana; Thomas, Peter J.

    2011-10-01

    The local delivery of extracellular high-frequency stimulation (HFS) has been shown to be a fast acting and quickly reversible method of blocking neural conduction and is currently being pursued for several clinical indications. However, the mechanism for this type of nerve block remains unclear. In this study, we investigate two hypotheses: (1) depolarizing currents promote conduction block via inactivation of sodium channels and (2) the gating dynamics of the fast sodium channel are the primary determinate of minimal blocking frequency. Hypothesis 1 was investigated using a combined modeling and experimental study to investigate the effect of depolarizing and hyperpolarizing currents on high-frequency block. The results of the modeling study show that both depolarizing and hyperpolarizing currents play an important role in conduction block and that the conductance to each of three ionic currents increases relative to resting values during HFS. However, depolarizing currents were found to promote the blocking effect, and hyperpolarizing currents were found to diminish the blocking effect. Inward sodium currents were larger than the sum of the outward currents, resulting in a net depolarization of the nodal membrane. Our experimental results support these findings and closely match results from the equivalent modeling scenario: intra-peritoneal administration of the persistent sodium channel blocker ranolazine resulted in an increase in the amplitude of HFS required to produce conduction block in rats, confirming that depolarizing currents promote the conduction block phenomenon. Hypothesis 2 was investigated using a spectral analysis of the channel gating variables in a single-fiber axon model. The results of this study suggested a relationship between the dynamical properties of specific ion channel gating elements and the contributions of corresponding conductances to block onset. Specifically, we show that the dynamics of the fast sodium inactivation gate are

  10. Purification of ethanol for highly sensitive self-assembly experiments

    PubMed Central

    Barbe, Kathrin; Kind, Martin; Pfeiffer, Christian

    2014-01-01

    Summary Ethanol is the preferred solvent for the formation of self-assembled monolayers (SAMs) of thiolates on gold. By applying a thin film sensor system, we could demonstrate that even the best commercial qualities of ethanol contain surface-active contaminants, which can compete with the desired thiolates for surface sites. Here we present that gold nanoparticles deposited onto zeolite X can be used to remove these contaminants by chemisorption. This nanoparticle-impregnated zeolite does not only show high capacities for surface-active contaminants, such as thiols, but can be fully regenerated via a simple pyrolysis protocol. PMID:25161861

  11. High Explosive Deonation Threshold Sensitivity Due to Multiple Fragment Impacts

    SciTech Connect

    Georgevich, V; Pincosy, P; Chase, J

    2004-01-07

    Fragments, bullets or projectiles can initiate a detonation in a high explosive (HE). For this to happen certain critical conditions need to be exceeded. For a given explosive, these critical conditions are the projectile velocity, the projectile size and shape, and the projectile material properties. A lot of work has been done in the area of metal shaped charge jets and individual fragments impacting the HE. One major gap in understanding initiation phenomena is the effect of multiple fragment impact. This study shows that multiple fragments can lower the fragment size and the kinetic energy thresholds.

  12. High-speed asynchronous optical sampling for high-sensitivity detection of coherent phonons

    NASA Astrophysics Data System (ADS)

    Dekorsy, T.; Taubert, R.; Hudert, F.; Schrenk, G.; Bartels, A.; Cerna, R.; Kotaidis, V.; Plech, A.; Köhler, K.; Schmitz, J.; Wagner, J.

    2007-12-01

    A new optical pump-probe technique is implemented for the investigation of coherent acoustic phonon dynamics in the GHz to THz frequency range which is based on two asynchronously linked femtosecond lasers. Asynchronous optical sampling (ASOPS) provides the performance of on all-optical oscilloscope and allows us to record optically induced lattice dynamics over nanosecond times with femtosecond resolution at scan rates of 10 kHz without any moving part in the set-up. Within 1 minute of data acquisition time signal-to-noise ratios better than 107 are achieved. We present examples of the high-sensitivity detection of coherent phonons in superlattices and of the coherent acoustic vibration of metallic nanoparticles.

  13. A Highly Sensitive, High-Throughput Assay for the Detection of Turner Syndrome

    PubMed Central

    Hager, Karl; Hosono, Seiyu; Wise, Anastasia; Li, Peining; Rinder, Henry M.; Gruen, Jeffrey R.

    2011-01-01

    Objective: Turner syndrome (TS) occurs when an X-chromosome is completely or partially deleted or when X-chromosomal mosaicism is present. Girls with TS benefit from early diagnosis and treatment with GH; however, many girls with TS are not detected until after 10 yr of age, resulting in delayed evaluation and treatment. Methods: We developed a high-throughput test for TS, based on a quantitative method of genotyping to detect X-chromosome abnormalities. This test uses pyrosequencing to quantitate relative allele strength (RAS) from single-nucleotide polymorphisms using 18 informative single-nucleotide polymorphisms markers that span the X-chromosome and one marker for the detection of Y-chromosome material. Results: Cutoff ranges for heterozygous, homozygous, or out-of-range RAS values were established from a cohort of 496 males and females. Positive TS scoring criteria were defined as the presence of homozygosity for all 18 markers or the presence of at least one out-of-range RAS value. To determine the validity of this rapid test for TS detection, we undertook a large-scale study using DNA from 132 females without TS and 74 females with TS for whom karyotypes were available. TS was identified with 96.0% sensitivity and 97.0% specificity in this cohort. We also tested buccal swab DNA from a group of 19 females without TS and 69 females with TS. In this group, TS was identified with 97.1% sensitivity and 84.2% specificity. Conclusions: These results demonstrate the validity of a high-throughput, pyrosequencing based test for the accurate detection of TS, providing a potential alternative to karyotype testing. PMID:21177792

  14. Method for rapid, high sensitivity tritiated water extraction

    SciTech Connect

    Failor, R.; Belovodsky, L.; Gaevoy, V.; Golubev, A.

    1997-04-20

    We have developed a thermal vacuum desorption process to rapidly extract water from environmental samples for tritium analysis. Thermal vacuum desorption allows for extraction of the moisture from the sample within a few hours in a form and quantity suitable for liquid scintillation counting and allows detection of tritium at the levels of <2 Bq/L of milk, <0.5 Bq/gm of vegetation, and < 0.5 Bq/gin of soil. We developed a prototype unit that can process batches of twenty or more samples within 24 hours. Early data shows that a high percentage of water is extracted reproducibly without enrichment or depletion of the tritium content. The quench coefficient of the extracted water is low allowing for accurate, direct liquid scintillation counting. Excellent comparison has been observed with results using freeze-dry lypholization as the water extraction method.

  15. A novel high resolution, high sensitivity SPECT detector for molecular imaging of cardiovascular diseases

    NASA Astrophysics Data System (ADS)

    Cusanno, F.; Argentieri, A.; Baiocchi, M.; Colilli, S.; Cisbani, E.; De Vincentis, G.; Fratoni, R.; Garibaldi, F.; Giuliani, F.; Gricia, M.; Lucentini, M.; Magliozzi, M. L.; Majewski, S.; Marano, G.; Musico, P.; Musumeci, M.; Santavenere, F.; Torrioli, S.; Tsui, B. M. W.; Vitelli, L.; Wang, Y.

    2010-05-01

    Cardiovascular diseases are the most common cause of death in western countries. Understanding the rupture of vulnerable atherosclerotic plaques and monitoring the effect of innovative therapies of heart failure is of fundamental importance. A flexible, high resolution, high sensitivity detector system for molecular imaging with radionuclides on small animal models has been designed for this aim. A prototype has been built using tungsten pinhole and LaBr3(Ce) scintillator coupled to Hamamatsu Flat Panel PMTs. Compact individual-channel readout has been designed, built and tested. Measurements with phantoms as well as pilot studies on mice have been performed, the results show that the myocardial perfusion in mice can be determined with sufficient precision. The detector will be improved replacing the Hamamatsu Flat Panel with Silicon Photomultipliers (SiPMs) to allow integration of the system with MRI scanners. Application of LaBr3(Ce) scintillator coupled to photosensor with high photon detection efficiency and excellent energy resolution will allow dual-label imaging to monitor simultaneously the cardiac perfusion and the molecular targets under investigation during the heart therapy.

  16. Birth Weight, Current Anthropometric Markers, and High Sensitivity C-Reactive Protein in Brazilian School Children

    PubMed Central

    Pellanda, Lucia Campos

    2015-01-01

    Studies have shown associations of birth weight with increased concentrations of high sensitivity C-reactive protein. This study assessed the relationship between birth weight, anthropometric and metabolic parameters during childhood, and high sensitivity C-reactive protein. A total of 612 Brazilian school children aged 5–13 years were included in the study. High sensitivity C-reactive protein was measured by particle-enhanced immunonephelometry. Nutritional status was assessed by body mass index, waist circumference, and skinfolds. Total cholesterol and fractions, triglycerides, and glucose were measured by enzymatic methods. Insulin sensitivity was determined by the homeostasis model assessment method. Statistical analysis included chi-square test, General Linear Model, and General Linear Model for Gamma Distribution. Body mass index, waist circumference, and skinfolds were directly associated with birth weight (P < 0.001, P = 0.001, and P = 0.015, resp.). Large for gestational age children showed higher high sensitivity C-reactive protein levels (P < 0.001) than small for gestational age. High birth weight is associated with higher levels of high sensitivity C-reactive protein, body mass index, waist circumference, and skinfolds. Large for gestational age altered high sensitivity C-reactive protein and promoted additional risk factor for atherosclerosis in these school children, independent of current nutritional status. PMID:25874126

  17. Highly Sensitive Nanoparticle-based Multifunctional Biosensor for Antigen Detection

    NASA Astrophysics Data System (ADS)

    Siavoshi, Salome

    Precise and selective positioning of nanoparticles gives rise to many applications where assembly of nano building blocks with different biological or chemical functionalization is necessary. One remarkable application is the simultaneous early detection of multiple biomarkers in the field of miniaturized multiplex biosensors. To enable multiplex detection of antigens, nanoparticles with various antibody coatings can be selectively assembled in trenches on different regions on a biochip so that they bind selectively to the specific antigen of interest. The presented work utilizes electric field assisted assembly techniques to assemble nanoparticles with various surface functionalization and coatings. Nanoparticles are assembled into pre-fabricated via and trench patterns generated on a PMMA coated gold surface, using electron-beam lithography. Two techniques have been developed for selective assembly of nanoparticles: sequential size-selective directed assembly and sequential site-selective assembly. Both selective assembly techniques provide fast and reproducible assembly over large areas while achieving high yield. The sequential size-selective assembly is a template-assisted technique where the selectivity is achieved by controlling the size of the nanopatterns and the size of the nanoparticles. The possibility of particle detachment and the factors affecting the sorting efficiency for this technique is studied. We show that a complete sorting can be achieved when the size of the vias is close to the diameter of the nanoparticles and the size distribution of the chosen nanoparticles do not overlap. In the site-selective assembly, the selectivity is achieved by having electrically isolated sites (regions) on the same chip. Electrophoresis is performed for each region in a step by step process. Selective assembly results, for up to four nanoparticles with various coating/functionalization are presented using the site-selective assembly technique. We use the

  18. (abstract) A Miniature, High-Sensitivity, Electron-Tunneling Accelerometer

    NASA Technical Reports Server (NTRS)

    Gabrielson, Thomas B.; Rockstad, Howard K.; Tang, Tony K.

    1994-01-01

    A prototype low-noise accelerometer has been fabricated with an electron-tunneling transducer. By measuring the tunneling current between an electrode on the proof mass and a feedback-controlled monitor electrode, very small accelerations can be detected with high responsivity. This particular prototype (10x10x1.5 mm) was designed for underwater acoustic measurement from a few hertz to 1 kHz. The measured responsivity below the fundamental device resonance at 100 Hz is roughly 1500 volts per m/s(sup 2) with a measured noise spectral density of 10(sup -6) m/s(sup 2) per root hertz or less between 30 and 300 Hz. The noise floor is controlled primarily by 1/f noise in the tunneling current although the noise floor reaches the theoretical molecular-agitation limit at 100 hertz. The responsivity and directivity of the device were measured in a standard gradient-hydrophone calibrator; the noise floor was determined in a vacuum-ionization chamber assembled from commercial off-the-shelf components; and the detailed dynamics of the proof-mass motion were examined using a heterodyne laser interferometer that was scanned across the surface and synchronously detected with respect to the excitation.

  19. Confidence Level and Sensitivity Limits in High Contrast Imaging

    SciTech Connect

    Marois, C

    2007-11-07

    In long adaptive optics corrected exposures, exoplanet detections are currently limited by speckle noise originating from the telescope and instrument optics, and it is expected that such noise will also limit future high-contrast imaging instruments for both ground and space-based telescopes. Previous theoretical analysis have shown that the time intensity variations of a single speckle follows a modified Rician. It is first demonstrated here that for a circular pupil this temporal intensity distribution also represents the speckle spatial intensity distribution at a fix separation from the point spread function center; this fact is demonstrated using numerical simulations for coronagraphic and non-coronagraphic data. The real statistical distribution of the noise needs to be taken into account explicitly when selecting a detection threshold appropriate for some desired confidence level. In this paper, a technique is described to obtain the pixel intensity distribution of an image and its corresponding confidence level as a function of the detection threshold. Using numerical simulations, it is shown that in the presence of speckles noise, a detection threshold up to three times higher is required to obtain a confidence level equivalent to that at 5{sigma} for Gaussian noise. The technique is then tested using TRIDENT CFHT and angular differential imaging NIRI Gemini adaptive optics data. It is found that the angular differential imaging technique produces quasi-Gaussian residuals, a remarkable result compared to classical adaptive optic imaging. A power-law is finally derived to predict the 1-3 x 10{sup -7} confidence level detection threshold when averaging a partially correlated non-Gaussian noise.

  20. Confidence Level and Sensitivity Limits in High Contrast Imaging

    SciTech Connect

    Marois, C; LaFreniere, D; Macintosh, B; Doyon, R

    2008-06-02

    In long adaptive optics corrected exposures, exoplanet detections are currently limited by speckle noise originating from the telescope and instrument optics, and it is expected that such noise will also limit future high-contrast imaging instruments for both ground and space-based telescopes. Previous theoretical analysis have shown that the time intensity variations of a single speckle follows a modified Rician. It is first demonstrated here that for a circular pupil this temporal intensity distribution also represents the speckle spatial intensity distribution at a fix separation from the point spread function center; this fact is demonstrated using numerical simulations for coronagraphic and non-coronagraphic data. The real statistical distribution of the noise needs to be taken into account explicitly when selecting a detection threshold appropriate for some desired confidence level. In this paper, a technique is described to obtain the pixel intensity distribution of an image and its corresponding confidence level as a function of the detection threshold. Using numerical simulations, it is shown that in the presence of speckles noise, a detection threshold up to three times higher is required to obtain a confidence level equivalent to that at 5{sigma} for Gaussian noise. The technique is then tested using TRIDENT CFHT and angular differential imaging NIRI Gemini adaptive optics data. It is found that the angular differential imaging technique produces quasi-Gaussian residuals, a remarkable result compared to classical adaptive optic imaging. A power-law is finally derived to predict the 1-3 x 10{sup -7} confidence level detection threshold when averaging a partially correlated non-Gaussian noise.

  1. Enhanced Laboratory Sensitivity to Variation of the Fine-Structure Constant using Highly Charged Ions

    SciTech Connect

    Berengut, J. C.; Dzuba, V. A.; Flambaum, V. V.

    2010-09-17

    We study atomic systems that are in the frequency range of optical atomic clocks and have enhanced sensitivity to potential time variation of the fine-structure constant {alpha}. The high sensitivity is due to coherent contributions from three factors: high nuclear charge Z, high ionization degree, and significant differences in the configuration composition of the states involved. Configuration crossing keeps the frequencies in the optical range despite the large ionization energies. We discuss a few promising examples that have the largest {alpha} sensitivities seen in atomic systems.

  2. Reduced graphene oxide electrically contacted graphene sensor for highly sensitive nitric oxide detection.

    PubMed

    Li, Weiwei; Geng, Xiumei; Guo, Yufen; Rong, Jizan; Gong, Youpin; Wu, Liqiong; Zhang, Xuemin; Li, Peng; Xu, Jianbao; Cheng, Guosheng; Sun, Mengtao; Liu, Liwei

    2011-09-27

    We develop graphene-based devices fabricated by alternating current dielectrophoresis (ac-DEP) for highly sensitive nitric oxide (NO) gas detection. The novel device comprises the sensitive channels of palladium-decorated reduced graphene oxide (Pd-RGO) and the electrodes covered with chemical vapor deposition (CVD)-grown graphene. The highly sensitive, recoverable, and reliable detection of NO gas ranging from 2 to 420 ppb with response time of several hundred seconds has been achieved at room temperature. The facile and scalable route for high performance suggests a promising application of graphene devices toward the human exhaled NO and environmental pollutant detections. PMID:21834585

  3. Distinct susceptibility to inoculated melanoma and sensitivity to cancer pain in mouse lines with high and low sensitivity to stress.

    PubMed

    Sacharczuk, Mariusz; Ragan, Agnieszka R; Szymanska, Hanna; Lesniak, Anna; Sadowski, Bogdan; Lipkowski, Andrzej W

    2012-01-01

    Approximately 30 years ago, we developed 2 mouse lines with enhanced and decreased opioid system activity using bidirectional selection for high (high analgesia [HA] line) and low (low analgesia [LA] line) swim stress-induced analgesia. These mouse lines differ substantially in pain sensitivity, measured as hind paw withdrawal latency in a hot plate test. Moreover, compared with the LA mice, the HA mice exhibited reduced energy expenditure under stress and different depression-like behavior as well as higher sensitivity to mutagens and the high frequency of spontaneous and carcinogen-induced tumors. In the current study, we observed distinct differences in the growth rate of orthotopically implanted melanoma and the onset of cancer pain. Whereas the HA line was prone to tumors and carcinogenesis was rapid in all specimens, the LA mice either did not develop tumors (70%) or developed tumors that often regressed spontaneously (30%). Animals from both lines developed robust thermal hypersensitivity in the tumor-bearing paw compared with animals that were injected with saline. However, we found that hyperalgesia in tumor-bearing mice persists for a much shorter time in the HA than in LA mice. Naltrexone, given subcutaneously, restored hyperalgesia in the HA mice, whereas it was ineffective in the LA mice. The results suggest that activity of the opioid system may influence carcinogenesis and the intensity of cancer pain and indicates that HA and LA mice are good models for such studies. PMID:23216641

  4. Confidence Level and Sensitivity Limits in High-Contrast Imaging

    NASA Astrophysics Data System (ADS)

    Marois, Christian; Lafrenière, David; Macintosh, Bruce; Doyon, René

    2008-01-01

    In long adaptive optics corrected exposures, exoplanet detections are currently limited by speckle noise originating from the telescope and instrument optics, and it is expected that such noise will also limit future high-contrast imaging instruments for both ground- and space-based telescopes. Previous theoretical analyses have shown that the time intensity variations of a single speckle follow a modified Rician. It is first demonstrated here that for a circular pupil, this temporal intensity distribution also represents the speckle spatial intensity distribution at a fixed separation from the point-spread function center; this fact is demonstrated using numerical simulations for coronagraphic and noncoronagraphic data. The real statistical distribution of the noise needs to be taken into account explicitly when selecting a detection threshold appropriate for some desired confidence level (CL). In this paper, a technique is described to obtain the pixel intensity distribution of an image and its corresponding CL as a function of the detection threshold. Using numerical simulations, it is shown that in the presence of speckle noise, a detection threshold up to 3 times higher is required to obtain a CL equivalent to that at 5 σ for Gaussian noise. The technique is then tested on data acquired by simultaneous spectral differential imaging with TRIDENT and by angular differential imaging with NIRI. It is found that the angular differential imaging technique produces quasi-Gaussian residuals, a remarkable result compared to classical adaptive optic imaging. Finally, a power law is derived to predict the 1 - 3 × 10-7 CL detection threshold when averaging a partially correlated non-Gaussian noise. Based on observations obtained at the Canada-France-Hawaii Telescope (CFHT), which is operated by the National Research Council of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique of France, and the University of

  5. Reward Sensitivity and Substance Abuse in Middle School and High School Students

    ERIC Educational Resources Information Center

    Genovese, Jeremy E. C.; Wallace, Deborah

    2007-01-01

    In this study, the authors investigated the relation between reward and punishment sensitivity and adolescent substance use. The sample (N = 216; 130 girls, 85 boys) was drawn from high school and middle school students enrolled in a Midwestern suburban school district. Participants completed a substance use questionnaire and the Sensitivity to…

  6. High-resolution and high-sensitivity tephra-inferred fingerprints in stalagmite geochemistry

    NASA Astrophysics Data System (ADS)

    Wu, Chung-Che; Burger, Marcel; Günther, Detlef; Hattendorf, Bodo; Shen, Chuan-Chou

    2016-04-01

    High-resolution and high-sensitivity rare earth elements (REEs) profiles of Holocene stalagmites collected from East Timor (8° 47' S, 126° 23' E) provide detailed fluctuation information which can be inferred to super volcano eruptions. Since REEs are enriched in igneous rocks (~ μg/g) but depleted in carbonates (~ ng/g to pg/g), REEs preserved in stalagmites are acted as an ideal proxy of tephra-inferred signature; however, due to the low REE abundances in most natural stalagmite samples (1-100s ng/g), overall applicability has been sharply limited. Here we develop and apply an improved LA-GED-ICPMS methodology to determine REEs in such low concentration stalagmites. Two pronounced REE peaks occur where their concentrations sharply increased by 1-2 order of magnitudes, from 10s of ng/g to 100s of ng/g. This event was dated at 80 thousand years ago by U-Th methods. Nevertheless, the accurate timing of this REE anomalous event should be examined carefully. Also more multi-proxies evidences such as stable isotopes δ13C, δ18O, and S isotope, should be provided in the future.

  7. Development of a 300,000-pixel ultrahigh-speed high-sensitivity CCD

    NASA Astrophysics Data System (ADS)

    Ohtake, H.; Hayashida, T.; Kitamura, K.; Arai, T.; Yonai, J.; Tanioka, K.; Maruyama, H.; Etoh, T. Goji; Poggemann, D.; Ruckelshausen, A.; van Kuijk, H.; Bosiers, Jan T.

    2006-02-01

    We are developing an ultrahigh-speed, high-sensitivity broadcast camera that is capable of capturing clear, smooth slow-motion videos even where lighting is limited, such as at professional baseball games played at night. In earlier work, we developed an ultrahigh-speed broadcast color camera1) using three 80,000-pixel ultrahigh-speed, highsensitivity CCDs2). This camera had about ten times the sensitivity of standard high-speed cameras, and enabled an entirely new style of presentation for sports broadcasts and science programs. Most notably, increasing the pixel count is crucially important for applying ultrahigh-speed, high-sensitivity CCDs to HDTV broadcasting. This paper provides a summary of our experimental development aimed at improving the resolution of CCD even further: a new ultrahigh-speed high-sensitivity CCD that increases the pixel count four-fold to 300,000 pixels.

  8. Highly sensitive and selective bioluminescence based ozone probes and their applications to detect ambient ozone.

    PubMed

    Nam, Younseok; Kim, Beom Seok; Shin, Injae

    2016-01-21

    Highly selective and sensitive bioluminescence based probes, which respond to ozone but not to other ROS, have been developed. These probes were used to determine ozone concentrations in environmental samples.

  9. Temperature insensitive hysteresis free highly sensitive polymer optical fiber Bragg grating humidity sensor.

    PubMed

    Woyessa, Getinet; Nielsen, Kristian; Stefani, Alessio; Markos, Christos; Bang, Ole

    2016-01-25

    The effect of humidity on annealing of poly (methyl methacrylate) (PMMA) based microstructured polymer optical fiber Bragg gratings (mPOFBGs) and the resulting humidity responsivity are investigated. Typically annealing of PMMA POFs is done in an oven without humidity control around 80°C and therefore at low humidity. We demonstrate that annealing at high humidity and high temperature improves the performances of mPOFBGs in terms of stability and sensitivity to humidity. PMMA POFBGs that are not annealed or annealed at low humidity level will have a low and highly temperature dependent sensitivity and a high hysteresis in the humidity response, in particular when operated at high temperature. PMMA mPOFBGs annealed at high humidity show higher and more linear humidity sensitivity with negligible hysteresis. We also report how annealing at high humidity can blue-shift the FBG wavelength more than 230 nm without loss in the grating strength. PMID:26832503

  10. High sensitivity and resolution integrated optical system for portable Raman spectrometer.

    PubMed

    Tang, Ming; Wang, Xin; Xianguang, Fan; Li, Wei; Xu, Yingjie; Que, Jing; He, Jian; Zuo, Yong

    2016-09-10

    An integrated optical system with high sensitivity and resolution was presented. This was made possible by coupling a probe to a monochromator directly, using an aspheric lens and an achromatic lens in the coupling path, using a dichroic filter with high transmission and a steep transitional zone as a beam splitter, increasing the throughput of the monochromator, and optimizing its structural parameters. This optical system has a high sensitivity; the tested spectrogram of a glass rod demonstrated that the signal-to-noise ratio measured by the integrated optical system was almost 4 times as high as an independent probe and monochromator. The optical system also has the advantages of high resolution (4  cm-1 or 0.28 nm), low cost, and portable size. This work lays a good groundwork for the development of a high sensitivity, high resolution, and low cost integrated portable Raman spectrometer.

  11. High sensitivity and resolution integrated optical system for portable Raman spectrometer.

    PubMed

    Tang, Ming; Wang, Xin; Xianguang, Fan; Li, Wei; Xu, Yingjie; Que, Jing; He, Jian; Zuo, Yong

    2016-09-10

    An integrated optical system with high sensitivity and resolution was presented. This was made possible by coupling a probe to a monochromator directly, using an aspheric lens and an achromatic lens in the coupling path, using a dichroic filter with high transmission and a steep transitional zone as a beam splitter, increasing the throughput of the monochromator, and optimizing its structural parameters. This optical system has a high sensitivity; the tested spectrogram of a glass rod demonstrated that the signal-to-noise ratio measured by the integrated optical system was almost 4 times as high as an independent probe and monochromator. The optical system also has the advantages of high resolution (4  cm-1 or 0.28 nm), low cost, and portable size. This work lays a good groundwork for the development of a high sensitivity, high resolution, and low cost integrated portable Raman spectrometer. PMID:27661352

  12. High-expression β(1) adrenergic receptor/cell membrane chromatography method based on a target receptor to screen active ingredients from traditional Chinese medicines.

    PubMed

    Yue, Yuan; Xue, Hui; Wang, Xin; Yang, Qian; Song, Yanhong; Li, Xiaoni

    2014-02-01

    β-Adrenergic receptors are important targets for drug discovery. We have developed a new β1 -adrenergic receptor cell membrane chromatography (β1 AR-CMC) with offline ultra-performance LC (UPLC) and MS method for screening active ingredients from traditional Chinese medicines. In this study, Chinese hamster ovary-S cells with high β1 AR expression levels were established and used to prepare a cell membrane stationary phase in a β1 AR-CMC model. The retention fractions were separated and identified by the UPLC-MS system. The screening results found that isoimperatorin from Rhizoma et Radix Notopterygii was the targeted component that could act on β1 AR in similar manner of metoprolol as a control drug. In addition, the biological effects of active component were also investigated in order to search for a new type of β1 AR antagonist. It will be a useful method for drug discovery as a leading compound resource.

  13. Comparison of different calibration approaches for chloramphenicol quantification in chicken muscle by ultra-high pressure liquid chromatography tandem mass spectrometry.

    PubMed

    Pan, Xiao-Dong; Jiang, Wei; Wu, Ping-Gu

    2015-01-01

    Matrix-dependent signal suppression often occurs in quantitative analysis by ultra-high pressure liquid chromatography tandem mass spectrometry (UPLC-MS/MS). In this study, we investigated three calibration methods for compensation of signal suppression on chloramphenicol (CAP) quantification in chicken muscle. The data showed that the spiking recoveries by solvent standard calibration with a stable isotope labelled internal standard (SIL-IS) and matrix-matched standard calibration with a SIL-IS were significantly higher than by external matrix-matched standard calibration (P < 0.05). When the SIL-IS was used, standards prepared in the mobile phase solvent showed no significant difference as those prepared in the matrix (P > 0.05). The limit of detection (LOD) for external matrix matched standard calibration was 0.1 μg kg(-1), and that for SIL-IS calibration (including matrix matched and solvent dissolved standard) was 0.03 μg kg(-1).

  14. Multi-residue and multi-class determination of antibiotics in gilthead sea bream (Sparus aurata) by ultra high-performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Freitas, Andreia; Leston, Sara; Rosa, João; Castilho, Maria da Conceição; Barbosa, Jorge; Rema, Paulo; Pardal, Miguel Ângelo; Ramos, Fernando

    2014-01-01

    This paper describes a method for the determination of 41 antibiotics from seven different classes in gilthead sea bream (Sparus aurata) by ultra-high-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS). Sulfonamides, trimethoprim, tetracyclines, macrolides, quinolones, penicillins and chloramphenicol were simultaneously determined. Fourteen procedures for sample treatment were tested and an extraction with acetonitrile and ethylenediaminetetra acetic acid was found to be the best option. The methodology was validated in accordance with Decision 2002/657/EC. Precision in terms of relative standard deviation (RSD) was under 17% for all compounds, and the recoveries ranged from 92% to 111%. CCα and CCβ were determined according to the maximum residue limit or the minimum required performance limit, when necessary. The validation provided evidence that the method was suitable for application in routine analysis for the detection and confirmation of antibiotics in muscle of gilthead sea bream, an important and intensively produced fish in aquaculture.

  15. A multiresidue approach for the simultaneous quantification of antibiotics in macroalgae by ultra-high performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Leston, Sara; Freitas, Andreia; Rosa, João; Barbosa, Jorge; Lemos, Marco F L; Pardal, Miguel Ângelo; Ramos, Fernando

    2016-10-15

    Together with fish, algae reared in aquaculture systems have gained importance in the last years, for many purposes. Besides their use as biofilters of effluents, macroalgae's rich nutritional profiles have increased their inclusion in human diets but also in animal feeds as sources of fatty acids, especially important for the fish industry. Nonetheless, algae are continuously exposed to environmental contaminants including antibiotics and possess the ability for bioaccumulation of such compounds. Therefore, the present paper describes the development and validation of an ultra-high performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous quantification of antibiotics in the green macroalgae Ulva lactuca. This multi-residue method enables the determination of 38 compounds distributed between seven classes and was fully validated according to EU Decision 2002/657/EC.

  16. A multiresidue approach for the simultaneous quantification of antibiotics in macroalgae by ultra-high performance liquid chromatography-tandem mass spectrometry.

    PubMed

    Leston, Sara; Freitas, Andreia; Rosa, João; Barbosa, Jorge; Lemos, Marco F L; Pardal, Miguel Ângelo; Ramos, Fernando

    2016-10-15

    Together with fish, algae reared in aquaculture systems have gained importance in the last years, for many purposes. Besides their use as biofilters of effluents, macroalgae's rich nutritional profiles have increased their inclusion in human diets but also in animal feeds as sources of fatty acids, especially important for the fish industry. Nonetheless, algae are continuously exposed to environmental contaminants including antibiotics and possess the ability for bioaccumulation of such compounds. Therefore, the present paper describes the development and validation of an ultra-high performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) method for the simultaneous quantification of antibiotics in the green macroalgae Ulva lactuca. This multi-residue method enables the determination of 38 compounds distributed between seven classes and was fully validated according to EU Decision 2002/657/EC. PMID:27627807

  17. High-sensitivity strain sensor based on inflated long period fiber grating.

    PubMed

    Zhong, Xiaoyong; Wang, Yiping; Qu, Junle; Liao, Changrui; Liu, Shen; Tang, Jian; Wang, Qiao; Zhao, Jing; Yang, Kaiming; Li, Zhengyong

    2014-09-15

    We demonstrated a high-sensitivity strain sensor based on an inflated long period fiber grating (I-LPFG). The I-LPFG was inscribed, for the first time to the best of our knowledge, by use of the pressure-assisted CO(2) laser beam scanning technique to inflate periodically air holes of a photonic crystal fiber. Such periodic inflations enhanced the sensitivity of the LPFG-based strain sensor to -5.62 pm/με. After high temperature annealing, the I-LPFG achieved a good repeatability and stability of temperature response with a sensitivity of 11.92 pm/°C. PMID:26466298

  18. Making sense of high sensitivity troponin assays and their role in clinical care.

    PubMed

    Daniels, Lori B

    2014-04-01

    Cardiac troponin assays have an established and undisputed role in the diagnosis and risk stratification of patients with acute myocardial infarction. As troponin assays gets more sensitive and more precise, the number of potential uses has rapidly expanded, but the use of this test has also become more complicated and controversial. Highly sensitive troponin assays can now detect troponin levels in most individuals, but accurate interpretation of these levels requires a clear understanding of the assay in the context of the clinical scenario. This paper provides a practical and up-to-date overview of the uses of highly sensitive troponin assays for diagnosis, prognosis, and risk stratification in clinical practice.

  19. Toward high-sensitivity and high-resolution submillimeter-wave video imaging

    NASA Astrophysics Data System (ADS)

    Heinz, Erik; May, Torsten; Born, Detlef; Zieger, Gabriel; Thorwirth, Günter; Anders, Solveig; Zakosarenko, Vyacheslav; Krause, Torsten; Krüger, André; Schulz, Marco; Meyer, Hans-Georg; Schubert, Marco; Starkloff, Michael

    2011-11-01

    Against a background of newly emerged security threats, the well-established idea of utilizing submillimeter-wave radiation for personal security screening applications has recently evolved into a promising technology. Possible application scenarios demand sensitive, fast, flexible and high-quality imaging techniques. At present, best results are obtained by passive imaging using cryogenic microbolometers as radiation detectors. Building upon the concept of a passive submillimeter-wave stand-off video camera introduced previously, we present the evolution of this concept into a practical application-ready imaging device. This has been achieved using a variety of measures such as optimizing the detector parameters, improving the scanning mechanism, increasing the sampling speed, and enhancing the image generation software. The camera concept is based on a Cassegrain-type mirror optics, an optomechanical scanner, an array of 20 superconducting transition-edge sensors operated at a temperature of 450 to 650 mK, and a closed-cycle cryogen-free cooling system. The main figures of the system include: a frequency band of 350+/-40 GHz, an object distance of 7 to 10 m, a circular field of view of 1.05 m diameter, and a spatial resolution in the image center of 2 cm at 8.5 m distance, a noise equivalent temperature difference of 0.1 to 0.4 K, and a maximum frame rate of 10 Hz.

  20. High-throughput, Highly Sensitive Analyses of Bacterial Morphogenesis Using Ultra Performance Liquid Chromatography.

    PubMed

    Desmarais, Samantha M; Tropini, Carolina; Miguel, Amanda; Cava, Felipe; Monds, Russell D; de Pedro, Miguel A; Huang, Kerwyn Casey

    2015-12-25

    The bacterial cell wall is a network of glycan strands cross-linked by short peptides (peptidoglycan); it is responsible for the mechanical integrity of the cell and shape determination. Liquid chromatography can be used to measure the abundance of the muropeptide subunits composing the cell wall. Characteristics such as the degree of cross-linking and average glycan strand length are known to vary across species. However, a systematic comparison among strains of a given species has yet to be undertaken, making it difficult to assess the origins of variability in peptidoglycan composition. We present a protocol for muropeptide analysis using ultra performance liquid chromatography (UPLC) and demonstrate that UPLC achieves resolution comparable with that of HPLC while requiring orders of magnitude less injection volume and a fraction of the elution time. We also developed a software platform to automate the identification and quantification of chromatographic peaks, which we demonstrate has improved accuracy relative to other software. This combined experimental and computational methodology revealed that peptidoglycan composition was approximately maintained across strains from three Gram-negative species despite taxonomical and morphological differences. Peptidoglycan composition and density were maintained after we systematically altered cell size in Escherichia coli using the antibiotic A22, indicating that cell shape is largely decoupled from the biochemistry of peptidoglycan synthesis. High-throughput, sensitive UPLC combined with our automated software for chromatographic analysis will accelerate the discovery of peptidoglycan composition and the molecular mechanisms of cell wall structure determination.

  1. High-resolution and high-intensity neutron diffractometer with linear position-sensitive detector

    NASA Astrophysics Data System (ADS)

    Lee, Chang-Hee; Moon, Myung-Kook; Em, V. T.; Choi, Young-Nam; Oh, Hwa-Suk; Nam, Uk-Won

    2003-08-01

    The characteristics of a neutron diffractometer using a 3He one-dimensional position-sensitive detector (PSD) with delay line readout, a 200 (length) × 100 (height) mm 2 active window and 2.5 mm spatial resolution have been studied and compared with those of the High-Resolution Powder Diffractometer (HRPD) of KAERI with 32 3He conventional tube (∅50 mm) detectors and Soller collimators (10') before detectors. For the sample to PSD distance R=1200 mm, the PSD subtends 8° angle of 2 θ and provides the resolution and the peak-to-background ratio close to that for HRPD. Time for scanning (with the same statistics) of a 0-160° interval is about 1.6 times longer and the multi-PSD system providing efficiency about 10 times higher than HRPD is proposed. Because of the small angle subtended by the PSD, the parasitic peaks from the sample environment are eliminated and operation without an oscillating radial collimator is possible. Additionally, the proposed diffractometer has an advantage for small samples.

  2. Sensitivity of the High Altitude Water Cherenkov Experiment to observe Gamma-Ray Bursts

    NASA Astrophysics Data System (ADS)

    González, M. M.

    Ground based telescopes have marginally observed very high energy emission (>100GeV) from gamma-ray bursts(GRB). For instance, Milagrito observed GRB970417a with a significance of 3.7 sigmas over the background. Milagro have not yet observed TeV emission from a GRB with its triggered and untriggered searches or GeV emission with a triggered search using its scalers. These results suggest the need of new observatories with higher sensitivity to transient sources. The HAWC (High Altitute Water Cherenkov) observatory is proposed as a combination of the Milagro tecnology with a very high altitude (>4000m over see level) site. The expected HAWC sensitivity for GRBs is at least >10 times the Milagro sensitivity. In this work HAWC sensitivity for GRBs is discussed for different detector configurations such as altitude, distance between PMTs, depth under water of PMTs, number of PMTs required for a trigger, etc.

  3. High-sensitivity temperature sensor based on a droplet-like fiber circle.

    PubMed

    Xie, Jianglei; Xu, Ben; Li, Yi; Kang, Juan; Shen, Changyu; Wang, Jianfeng; Jin, Yongxing; Liu, Honglin; Ni, Kai; Dong, Xinyong; Zhao, Chunliu; Jin, Shangzhong

    2014-06-20

    A low-cost yet high-sensitivity temperature fiber sensor is proposed and demonstrated in this paper. A single-mode fiber with coating is simply bent in a droplet-like circle with a radius of several millimeters. The strong bending induces mode interferences between the silica core mode and the excited modes propagating in the polymer coating. Many resonant dips were observed in the transmission spectra and are found to shift to a shorter wavelength with the increase of environmental temperature. Our linear fitting result of the experimental data shows that the proposed sensor presents high temperature sensitivity up to -3.102  nm/°C, which is even comparable with sensors based on selective liquid-filled photonic crystal fibers. Such high temperature sensitivity results from the large thermo-optical coefficient difference between the silica core and the polymer coating. The influence of a circle radius to the sensitivities is also discussed. PMID:24979444

  4. Fano resonance-based highly sensitive, compact temperature sensor on thin film lithium niobate.

    PubMed

    Qiu, Wentao; Ndao, Abdoulaye; Vila, Venancio Calero; Salut, Roland; Courjal, Nadège; Baida, Fadi Issam; Bernal, Maria-Pilar

    2016-03-15

    In this Letter, we report a Fano resonance-based highly sensitive and compact temperature sensor fabricated on thin film lithium niobate (TFLN) Suzuki phase lattice (SPL) photonic crystal. The experimental sensitivity is estimated to be 0.77 nm/°C with a photonic crystal size of only 25  μm × 24  μm. This sensitivity is 38 times larger than the intrinsic one of lithium niobate which is 0.02 nm/°C. The demonstrated sharp and high extinction ratio characteristics of the Fano lineshape resonance could be an excellent candidate in developing a high sensitivity temperature sensor, electric field sensor, etc. PMID:26977645

  5. Coupled Aerodynamic and Structural Sensitivity Analysis of a High-Speed Civil Transport

    NASA Technical Reports Server (NTRS)

    Mason, B. H.; Walsh, J. L.

    2001-01-01

    An objective of the High Performance Computing and Communication Program at the NASA Langley Research Center is to demonstrate multidisciplinary shape and sizing optimization of a complete aerospace vehicle configuration by using high-fidelity, finite-element structural analysis and computational fluid dynamics aerodynamic analysis. In a previous study, a multi-disciplinary analysis system for a high-speed civil transport was formulated to integrate a set of existing discipline analysis codes, some of them computationally intensive, This paper is an extension of the previous study, in which the sensitivity analysis for the coupled aerodynamic and structural analysis problem is formulated and implemented. Uncoupled stress sensitivities computed with a constant load vector in a commercial finite element analysis code are compared to coupled aeroelastic sensitivities computed by finite differences. The computational expense of these sensitivity calculation methods is discussed.

  6. Highly sensitive electronic whiskers based on patterned carbon nanotube and silver nanoparticle composite films.

    PubMed

    Takei, Kuniharu; Yu, Zhibin; Zheng, Maxwell; Ota, Hiroki; Takahashi, Toshitake; Javey, Ali

    2014-02-01

    Mammalian whiskers present an important class of tactile sensors that complement the functionalities of skin for detecting wind with high sensitivity and navigation around local obstacles. Here, we report electronic whiskers based on highly tunable composite films of carbon nanotubes and silver nanoparticles that are patterned on high-aspect-ratio elastic fibers. The nanotubes form a conductive network matrix with excellent bendability, and nanoparticle loading enhances the conductivity and endows the composite with high strain sensitivity. The resistivity of the composites is highly sensitive to strain with a pressure sensitivity of up to ∼8%/Pa for the whiskers, which is >10× higher than all previously reported capacitive or resistive pressure sensors. It is notable that the resistivity and sensitivity of the composite films can be readily modulated by a few orders of magnitude by changing the composition ratio of the components, thereby allowing for exploration of whisker sensors with excellent performance. Systems consisting of whisker arrays are fabricated, and as a proof of concept, real-time two- and three-dimensional gas-flow mapping is demonstrated. The ultrahigh sensitivity and ease of fabrication of the demonstrated whiskers may enable a wide range of applications in advanced robotics and human-machine interfacing. PMID:24449857

  7. Interpersonal sensitivity and functioning impairment in youth at ultra-high risk for psychosis.

    PubMed

    Masillo, A; Valmaggia, L R; Saba, R; Brandizzi, M; Lindau, J F; Solfanelli, A; Curto, M; Narilli, F; Telesforo, L; Kotzalidis, G D; Di Pietro, D; D'Alema, M; Girardi, P; Fiori Nastro, P

    2016-01-01

    A personality trait that often elicits poor and uneasy interpersonal relationships is interpersonal sensitivity. The aim of the present study was to explore the relationship between interpersonal sensitivity and psychosocial functioning in individuals at ultra-high risk for psychosis as compared to help-seeking individuals who screened negative for an ultra-high risk of psychosis. A total sample of 147 adolescents and young adult who were help seeking for emerging mental health problems participated in the study. The sample was divided into two groups: 39 individuals who met criteria for an ultra-high-risk mental state (UHR), and 108 (NS). The whole sample completed the Interpersonal Sensitivity Measure (IPSM) and the Global Functioning: Social and Role Scale (GF:SS; GF:RS). Mediation analysis was used to explore whether attenuated negative symptoms mediated the relationship between interpersonal sensitivity and social functioning. Individuals with UHR state showed higher IPSM scores and lower GF:SS and GF:RS scores than NS participants. A statistically negative significant correlation between two IPSM subscales (Interpersonal Awareness and Timidity) and GF:SS was found in both groups. Our results also suggest that the relationship between the aforementioned aspects of interpersonal sensitivity and social functioning was not mediated by negative prodromal symptoms. This study suggests that some aspects of interpersonal sensitivity were associated with low level of social functioning. Assessing and treating interpersonal sensitivity may be a promising therapeutic target to improve social functioning in young help-seeking individuals.

  8. Variable sensitivity of US maize yield to high temperatures across developmental stages

    NASA Astrophysics Data System (ADS)

    Butler, E. E.; Huybers, P. J.

    2013-12-01

    The sensitivity of maize to high temperatures has been widely demonstrated. Furthermore, field work has indicated that reproductive development stages are particularly sensitive to stress, but this relationship has not been quantified across a wide geographic region. Here, the relationship between maize yield and temperature variations is examined as a function of developmental stage. US state-level data from the National Agriculture Statistics Service provide dates for six growing stages: planting, silking, doughing, dented, mature, and harvested. Temperatures that correspond to each developmental stage are then inferred from a network of weather station observations interpolated to the county level, and a multiple linear regression technique is employed to estimate the sensitivity of county yield outcomes to variations in growing-degree days and an analogous measure of high temperatures referred to as killing-degree days. Uncertainties in the transition times between county-level growth stages are accounted for. Results indicate that the silking and dented stages are generally the most sensitive to killing degree days, with silking the most sensitive stage in the US South and dented the most sensitive in the US North. These variable patterns of sensitivity aid in interpreting which weather events are of greatest significance to maize yields and provide some insight into how shifts in planting time or changes in developmental timing would influence the risks associated with exposure to high temperatures.

  9. Highly Sensitive Electrochemical Determination of Alfatoxin B1 Using Quantum Dots-Assembled Amplification Labels

    PubMed Central

    Zeng, Xiaoqun; Gao, Huiju; Pan, Daodong; Sun, Yangying; Cao, Jinxuan; Wu, Zhen; Pan, Zhenyu

    2015-01-01

    A competitive electrochemical immunoassay for highly sensitive detection of AFB1 is demonstrated using layer-by-layer (LBL) assembled quantum dots (QDs) as labels. To investigate the effects of the higher sensitivity of square wave voltammetric stripping (SWV) and of the LBL technique on the proposed immunoassays, the proposed assay was compared to electrochemical (EC) and fluorescent immunoassays, which did not use LBL technology. Peanut samples were analyzed using the three immunoassays. The limits of detection (LODs) were 0.018, 0.046 and 0.212 ng/mL, respectively, while the sensitivities were 0.308, 1.011 and 4.594 ng/mL, respectively. The proposed electrochemical immunoassay displayed a significant improvement in sensitivity, thereby providing a simple and sensitive alternative strategy for determining AFB1 levels in peanut samples. PMID:26307990

  10. Highly sensitive and reconfigurable fiber optic current sensor by optical recirculating in a fiber loop.

    PubMed

    Du, Jiangbing; Tao, Yemeng; Liu, Yinping; Ma, Lin; Zhang, Wenjia; He, Zuyuan

    2016-08-01

    An advanced fiber optic current sensor (FOCS) is proposed based on recirculating fiber loop architecture for significantly enhancing the current sensitivity. The recirculating loop is constructed by a 2X2 optical switch and the standard single mode fiber (SSMF) is used as the sensing head. The proposed FOCS is coupler-free with low insertion loss which results in a significantly improved current sensitivity. We experimentally obtained a sensitivity of 11.5 degrees/A for 1-Km SSMF FOCS and a sensitivity of 21.2 degrees/A for 500-m SSMF FOCS, both of which have been enhanced by more than ten times. The flexible switch control of recirculating can support the FOCS to work for different current scenarios with the same system and thus reconfigurable operation of the FOCS has been achieved. The significantly enhanced high sensitivity with reconfigurable operation capability makes the proposed FOCS a promising method for practical applications. PMID:27505765

  11. Highly Sensitive Electrochemical Determination of Alfatoxin B1 Using Quantum Dots-Assembled Amplification Labels.

    PubMed

    Zeng, Xiaoqun; Gao, Huiju; Pan, Daodong; Sun, Yangying; Cao, Jinxuan; Wu, Zhen; Pan, Zhenyu

    2015-01-01

    A competitive electrochemical immunoassay for highly sensitive detection of AFB1 is demonstrated using layer-by-layer (LBL) assembled quantum dots (QDs) as labels. To investigate the effects of the higher sensitivity of square wave voltammetric stripping (SWV) and of the LBL technique on the proposed immunoassays, the proposed assay was compared to electrochemical (EC) and fluorescent immunoassays, which did not use LBL technology. Peanut samples were analyzed using the three immunoassays. The limits of detection (LODs) were 0.018, 0.046 and 0.212 ng/mL, respectively, while the sensitivities were 0.308, 1.011 and 4.594 ng/mL, respectively. The proposed electrochemical immunoassay displayed a significant improvement in sensitivity, thereby providing a simple and sensitive alternative strategy for determining AFB1 levels in peanut samples. PMID:26307990

  12. Highly Sensitive Electrochemical Determination of Alfatoxin B1 Using Quantum Dots-Assembled Amplification Labels.

    PubMed

    Zeng, Xiaoqun; Gao, Huiju; Pan, Daodong; Sun, Yangying; Cao, Jinxuan; Wu, Zhen; Pan, Zhenyu

    2015-08-20

    A competitive electrochemical immunoassay for highly sensitive detection of AFB1 is demonstrated using layer-by-layer (LBL) assembled quantum dots (QDs) as labels. To investigate the effects of the higher sensitivity of square wave voltammetric stripping (SWV) and of the LBL technique on the proposed immunoassays, the proposed assay was compared to electrochemical (EC) and fluorescent immunoassays, which did not use LBL technology. Peanut samples were analyzed using the three immunoassays. The limits of detection (LODs) were 0.018, 0.046 and 0.212 ng/mL, respectively, while the sensitivities were 0.308, 1.011 and 4.594 ng/mL, respectively. The proposed electrochemical immunoassay displayed a significant improvement in sensitivity, thereby providing a simple and sensitive alternative strategy for determining AFB1 levels in peanut samples.

  13. Structure-function analysis identifies highly sensitive strigolactone receptors in Striga.

    PubMed

    Toh, Shigeo; Holbrook-Smith, Duncan; Stogios, Peter J; Onopriyenko, Olena; Lumba, Shelley; Tsuchiya, Yuichiro; Savchenko, Alexei; McCourt, Peter

    2015-10-01

    Strigolactones are naturally occurring signaling molecules that affect plant development, fungi-plant interactions, and parasitic plant infestations. We characterized the function of 11 strigolactone receptors from the parasitic plant Striga hermonthica using chemical and structural biology. We found a clade of polyspecific receptors, including one that is sensitive to picomolar concentrations of strigolactone. A crystal structure of a highly sensitive strigolactone receptor from Striga revealed a larger binding pocket than that of the Arabidopsis receptor, which could explain the increased range of strigolactone sensitivity. Thus, the sensitivity of Striga to strigolactones from host plants is driven by receptor sensitivity. By expressing strigolactone receptors in Arabidopsis, we developed a bioassay that can be used to identify chemicals and crops with altered strigolactone levels. PMID:26450211

  14. Proposed helmet PET geometries with add-on detectors for high sensitivity brain imaging

    NASA Astrophysics Data System (ADS)

    Tashima, Hideaki; Yamaya, Taiga

    2016-10-01

    For dedicated brain PET, we can significantly improve sensitivity for the cerebrum region by arranging detectors in a compact hemisphere. The geometrical sensitivity for the top region of the hemisphere is increased compared with conventional cylindrical PET consisting of the same number of detectors. However, the geometrical sensitivity at the center region of the hemisphere is still low because the bottom edge of the field-of-view is open, the same as for the cylindrical PET. In this paper, we proposed a helmet PET with add-on detectors for high sensitivity brain PET imaging for both center and top regions. The key point is the add-on detectors covering some portion of the spherical surface in addition to the hemisphere. As the location of the add-on detectors, we proposed three choices: a chin detector, ear detectors, and a neck detector. For example, the geometrical sensitivity for the region-of-interest at the center was increased by 200% by adding the chin detector which increased the size by 12% of the size of the hemisphere detector. The other add-on detectors gave almost the same increased sensitivity effect as the chin detector did. Compared with standard whole-body-cylindrical PET, the proposed geometries can achieve 2.6 times higher sensitivity for brain region even with less than 1/4 detectors. In addition, we conducted imaging simulations for geometries with a diameter of 250 mm and with high resolution depth-of-interaction detectors. The simulation results showed that the proposed geometries increased image quality, and all of the add-on detectors were equivalently effective. In conclusion, the proposed geometries have high potential for widespread applications in high-sensitivity, high-resolution, and low-cost brain PET imaging.

  15. Towards high-sensitivity and high-resolution submillimeter-wave video imaging

    NASA Astrophysics Data System (ADS)

    Heinz, Erik; May, Torsten; Born, Detlef; Zieger, Gabriel; Anders, Solveig; Zakosarenko, Viatcheslav; Schubert, Marco; Krause, Torsten; Krüger, André; Schulz, Marco; Meyer, Hans-Georg

    2011-05-01

    Against a background of newly emerged security threats the well-established idea of utilizing submillimeter-wave radiation for personal security screening applications has recently evolved into a promising technology. Possible application scenarios demand sensitive, fast, flexible and high-quality imaging techniques. At present, best results are obtained by passive imaging using cryogenic microbolometers as radiation detectors. Building upon the concept of a passive submillimeter-wave stand-off video camera introduced previously, we present the evolution of this concept in a practical application-ready imaging device. This has been achieved using a variety of measures such as optimizing the detector parameters, improving the scanning mechanism, increasing the sampling speed, and enhancing the camera software. The image generation algorithm has been improved and an automatic sensor calibration technique has been implemented taking advantage of redundancy in the sensor data. The concept is based on a Cassegrain-type mirror optics, an opto-mechanical scanner providing spiraliform scanning traces, and an array of 20 superconducting transition-edge sensors (TES) operated at a temperature of 450-650 mK. The TES are cooled by a closed-cycle cooling system and read out by superconducting quantum interference devices (SQUIDs). The frequency band of operation centers around 350 GHz. The camera can operate at an object distance of 7-10 m. At 9m distance it covers a field of view of 110 cm diameter, achieves a spatial resolution of 2 cm and a pixel NETD (noise equivalent temperature difference) of 0.1-0.4 K. The maximum frame rate is 10 frames per second.

  16. Is sensitivity to reward associated with the malleability of implicit inclinations toward high-fat food?

    PubMed

    Ashby, Casey R; Stritzke, Werner G K

    2013-08-01

    Two experiments examined the effect of positive and negative priming on implicit approach and avoidance inclinations toward high-fat food stimuli in participants high or low in reward sensitivity, using personalized unipolar variants of the Implicit Association Test (IAT; A. G. Greenwald, D. E. McGhee, & J. L. K. Schwartz, 1998, "Measuring individual differences in implicit cognition: The Implicit Association Test," Journal of Personality and Social Psychology, Vol. 74, pp. 1464-1480). Participants high in reward sensitivity showed an automatic processing bias that is characterized by a dual vulnerability of being particularly susceptible to priming of the rewarding aspects of high-fat foods, while being unaffected by priming of the negative aspects of those foods. In contrast, participants low in reward sensitivity generally showed no facilitation of implicit-approach inclinations following positive priming, but consistently showed facilitation of implicit-avoidance inclinations following negative priming. These results are consistent with the revised reinforcement sensitivity theory ( J. A. Gray & N. McNaughton, 2000, The neuropsychology of anxiety: An enquiry into the functions of the septo-hippocampal system, 2nd ed., New York, NY, Oxford University Press.) and suggest that the systems mediating reward sensitivity and punishment sensitivity are not orthogonal, as predicted by the separable subsystems hypothesis, but can be interdependent, as predicted by the joint subsystems hypothesis.

  17. Is sensitivity to reward associated with the malleability of implicit inclinations toward high-fat food?

    PubMed

    Ashby, Casey R; Stritzke, Werner G K

    2013-08-01

    Two experiments examined the effect of positive and negative priming on implicit approach and avoidance inclinations toward high-fat food stimuli in participants high or low in reward sensitivity, using personalized unipolar variants of the Implicit Association Test (IAT; A. G. Greenwald, D. E. McGhee, & J. L. K. Schwartz, 1998, "Measuring individual differences in implicit cognition: The Implicit Association Test," Journal of Personality and Social Psychology, Vol. 74, pp. 1464-1480). Participants high in reward sensitivity showed an automatic processing bias that is characterized by a dual vulnerability of being particularly susceptible to priming of the rewarding aspects of high-fat foods, while being unaffected by priming of the negative aspects of those foods. In contrast, participants low in reward sensitivity generally showed no facilitation of implicit-approach inclinations following positive priming, but consistently showed facilitation of implicit-avoidance inclinations following negative priming. These results are consistent with the revised reinforcement sensitivity theory ( J. A. Gray & N. McNaughton, 2000, The neuropsychology of anxiety: An enquiry into the functions of the septo-hippocampal system, 2nd ed., New York, NY, Oxford University Press.) and suggest that the systems mediating reward sensitivity and punishment sensitivity are not orthogonal, as predicted by the separable subsystems hypothesis, but can be interdependent, as predicted by the joint subsystems hypothesis. PMID:23527505

  18. Longevity Tests of High-Sensitivity BD-PND Bubble Dosimeters

    SciTech Connect

    Radev, R; Carlberg, E

    2002-07-09

    Medium- and very-high-sensitivity neutron bubble dosimeters (BD-PNDs) made by Bubble Technology Industries (BTI) were used to study the life span of such dosimeters in a standard setup with a {sup 252}Cf source. Although data on the longevity of bubble dosimeters with low and medium sensitivity exist, such data for dosimeters with high and very high sensitivity are not readily available. The manufacturer guarantees optimum dosimeter performance for 3 months after receipt. However, it is important to know the change in the dosimeters' characteristics with time, especially after the first 3 months. The long-term performance of four sets of very high sensitivity and one set of medium-sensitivity bubble dosimeters was examined for periods of up to 13 months. During that time, the detectors were exposed and reset more than 20 times. Although departures from initial detection sensitivity were observed in several cases, the detectors indicated a significantly longer life span than stated in the manufacturer's warranty. In addition, the change in the number of bubbles and in evaluated neutron dose as a function of the time from the end of exposure until the dosimeters were read was investigated.

  19. Green laser excited surface plasmon resonance biosensor utilizing highly sensitive phase interrogation detection

    NASA Astrophysics Data System (ADS)

    Chen, How-Foo; Hsu, Wei-Chen; Wang, Ya-Jung; Yen, Ta-Jen

    2010-04-01

    Surface plasmon resonance (SPR) biosensors have been widely used for dynamical analysis of molecular affinity, bacterium screening, and drug discovery due to its advantages of label-free detection, dynamic interaction analysis, small sample volume, and ultra sensitivity (feasibility of single molecular detection). Recently, SPR biosensing for cell imaging known as SPR microscopy (SPRM) has attracted great attention due to the characteristics of SPR biosensors. However, it is well known that the trends of sensitivity and spatial resolution are opposite to each other: Surface plasmon waves (SPWs) with shorter wavelength which provides higher spatial resolution has less sensitivity. It is known that the spatial resolution of SPRM is limited by the propagation length of surface plasmon wave (SPW) along the metaldielectric interface. SPW excited by 632.8 nm light has the propagation length of 3 um. This length becomes longer when a longer wavelength is selected. While most of SPR biosensors are built with 632.8 nm or longer wavelength for high sensitivity, using 532nm light to excite SPWs is desired for submicron resolution since the propagation length is around 150 nm. Different from current phase interrogation methods, the proposed phase interrogation method is highly sensitive and suitable for CCD imaging. Although it is generally believed that SPWs with wavelength 532nm has poor sensitivity, the experimental result showed that the setup can reach the sensitivity lower than 2×10-6 RIU when sucrose is used as the test sample.

  20. Highly sensitive detection of dipicolinic acid with a water-dispersible terbium-metal organic framework.

    PubMed

    Bhardwaj, Neha; Bhardwaj, Sanjeev; Mehta, Jyotsana; Kim, Ki-Hyun; Deep, Akash

    2016-12-15

    The sensitive detection of dipicolinic acid (DPA) is strongly associated with the sensing of bacterial organisms in food and many types of environmental samples. To date, the demand for a sensitive detection method for bacterial toxicity has increased remarkably. Herein, we investigated the DPA detection potential of a water-dispersible terbium-metal organic framework (Tb-MOF) based on the fluorescence quenching mechanism. The Tb-MOF showed a highly sensitive ability to detect DPA at a limit of detection of 0.04nM (linear range of detection: 1nM to 5µM) and also offered enhanced selectivity from other commonly associated organic molecules. The present study provides a basis for the application of Tb-MOF for direct, convenient, highly sensitive, and specific detection of DPA in the actual samples.

  1. Highly sensitive detection of dipicolinic acid with a water-dispersible terbium-metal organic framework.

    PubMed

    Bhardwaj, Neha; Bhardwaj, Sanjeev; Mehta, Jyotsana; Kim, Ki-Hyun; Deep, Akash

    2016-12-15

    The sensitive detection of dipicolinic acid (DPA) is strongly associated with the sensing of bacterial organisms in food and many types of environmental samples. To date, the demand for a sensitive detection method for bacterial toxicity has increased remarkably. Herein, we investigated the DPA detection potential of a water-dispersible terbium-metal organic framework (Tb-MOF) based on the fluorescence quenching mechanism. The Tb-MOF showed a highly sensitive ability to detect DPA at a limit of detection of 0.04nM (linear range of detection: 1nM to 5µM) and also offered enhanced selectivity from other commonly associated organic molecules. The present study provides a basis for the application of Tb-MOF for direct, convenient, highly sensitive, and specific detection of DPA in the actual samples. PMID:27479046

  2. Highly sensitive digoxigenin-labelled DNA probe for the detection of potato spindle tuber viroid.

    PubMed

    Welnicki, M; Hiruki, C

    1992-09-01

    A molecular probe pSPAv6.2(+), with concatameric insert representing 6.2-times repeated copy of potato spindle tuber viroid (PSTV) RNA, was labelled with digoxigenin and used to detect PSTV by dot-blot hybridization assay. The probe was highly sensitive and specific, detecting as little as 2.5 pg of PSTV RNA. Both severe and mild PSTV strains were detectable in 64-512-times diluted crude extracts from infected tomato leaves, and potato leaves, sprouts, and seeds. For extraction of plant tissue three buffers were compared to determine the lowest non-specific background and the highest sensitivity. The results showed that the digoxigenin-labelled probe is as sensitive as the 32P-labelled probe and can replace radioactive techniques in PSTV detection. With such high sensitivity, the probe is also potentially useful for detecting the viroid in composite samples of mass-indexing programs.

  3. Polycrystalline CVD diamond detector: Fast response and high sensitivity with large area

    SciTech Connect

    Liu, Linyue Zhang, Xianpeng; Zhong, Yunhong; Ouyang, Xiaoping Zhang, Jianfu

    2014-01-15

    Polycrystalline diamond was successfully used to fabricate a large area (diameter up to 46 mm) radiation detector. It was proven that the developed detector shows a fast pulsed response time and a high sensitivity, therefore its rise time is lower than 5 ns, which is two times faster than that of a Si-PIN detector of the same size. And because of the large sensitive area, this detector shows good dominance in fast pulsed and low density radiation detection.

  4. High-sensitivity Fabry-Perot interferometric pressure sensor based on a nanothick silver diaphragm.

    PubMed

    Xu, Feng; Ren, Dongxu; Shi, Xiaolong; Li, Can; Lu, Weiwei; Lu, Lu; Lu, Liang; Yu, Benli

    2012-01-15

    We present a fiber-optic extrinsic Fabry-Perot interferometer pressure sensor based on a nanothick silver diaphragm. The sensing diaphragm, with a thickness measured in a few hundreds of nanometers, is fabricated by the electroless plating method, which provides a simple fabrication process involving a high-quality diaphragm at a low cost. The sensor exhibits a relatively linear response within the pressure variation range of 0-50 kPa, with a high pressure sensitivity of 70.5 nm/kPa. This sensor is expected to have potential applications in the field of highly sensitive pressure sensors. PMID:22854444

  5. Highly sensitive detection of alkaline phosphatase using molecular beacon probes based on enzymatic polymerization.

    PubMed

    Ma, Changbei

    2012-06-01

    We have developed a new methodology for highly sensitive alkaline phosphatase assay using molecular beacon probes. No incubation step is needed to obtain a limit of detection for ALP of 2×10(-16) M. Furthermore, ALP inhibition by the inhibitor okadaic acid is shown, demonstrating the potential for high-throughput screening for inhibitors.

  6. High sensitivity phase retrieval method in grating-based x-ray phase contrast imaging

    SciTech Connect

    Wu, Zhao; Gao, Kun; Chen, Jian; Wang, Dajiang; Wang, Shenghao; Chen, Heng; Bao, Yuan; Shao, Qigang; Wang, Zhili; Zhang, Kai; Zhu, Peiping; Wu, Ziyu

    2015-02-15

    Purpose: Grating-based x-ray phase contrast imaging is considered as one of the most promising techniques for future medical imaging. Many different methods have been developed to retrieve phase signal, among which the phase stepping (PS) method is widely used. However, further practical implementations are hindered, due to its complex scanning mode and high radiation dose. In contrast, the reverse projection (RP) method is a novel fast and low dose extraction approach. In this contribution, the authors present a quantitative analysis of the noise properties of the refraction signals retrieved by the two methods and compare their sensitivities. Methods: Using the error propagation formula, the authors analyze theoretically the signal-to-noise ratios (SNRs) of the refraction images retrieved by the two methods. Then, the sensitivities of the two extraction methods are compared under an identical exposure dose. Numerical experiments are performed to validate the theoretical results and provide some quantitative insight. Results: The SNRs of the two methods are both dependent on the system parameters, but in different ways. Comparison between their sensitivities reveals that for the refraction signal, the RP method possesses a higher sensitivity, especially in the case of high visibility and/or at the edge of the object. Conclusions: Compared with the PS method, the RP method has a superior sensitivity and provides refraction images with a higher SNR. Therefore, one can obtain highly sensitive refraction images in grating-based phase contrast imaging. This is very important for future preclinical and clinical implementations.

  7. New approaches to donor crossmatching and successful transplantation of highly sensitized patients.

    PubMed

    Delmonico, F L; Fuller, A; Cosimi, A B; Tolkoff-Rubin, N; Russell, P S; Rodey, G E; Fuller, T C

    1983-12-01

    A class I HLA molecule may bear not only a private or unique determinant, but a shared, yet discrete, public epitope. These public determinants occur with a much higher frequency in the random donor population than the associated private determinants--and thus, are encountered more often in random donor blood transfusions and in renal transplantation. Sera from highly sensitized dialysis patients have been reported to contain a restricted number of antibodies to public determinants rather than a diverse array of antibodies directed against the private HLA-AB epitopes. As detailed in this report, comprehensive serum analysis of the public antibodies in highly sensitized transplant candidates has optimized identification of potential crossmatch-compatible donors and has avoided needless crossmatches. During the past two years, the incidence of renal transplantation from cadaveric donors to highly sensitized recipients has doubled at this institution. At 10-25 months following transplantation, 70% of these allografts are functioning. Private HLA class I antigen incompatibility was not a barometer for exclusion in the final donor crossmatch of these highly sensitized recipients. Furthermore, positive donor T cell crossmatches with sera obtained more than six months prior to transplantation may not represent an impediment to successful transplantation. We conclude that the approach of detailed antibody analysis can result in an improved outlook for successful transplantation of more dialysis patients who are highly sensitized to the class I HLA alloantigens.

  8. Ultra high vacuum pumping system and high sensitivity helium leak detector

    DOEpatents

    Myneni, G.R.

    1997-12-30

    An improved helium leak detection method and apparatus are disclosed which increase the leak detection sensitivity to 10{sup {minus}13} atm cc/s. The leak detection sensitivity is improved over conventional leak detectors by completely eliminating the use of o-rings, equipping the system with oil-free pumping systems, and by introducing measured flows of nitrogen at the entrances of both the turbo pump and backing pump to keep the system free of helium background. The addition of dry nitrogen flows to the system reduces back streaming of atmospheric helium through the pumping system as a result of the limited compression ratios of the pumps for helium. 2 figs.

  9. Ultra high vacuum pumping system and high sensitivity helium leak detector

    DOEpatents

    Myneni, Ganapati Rao

    1997-01-01

    An improved helium leak detection method and apparatus are disclosed which increase the leak detection sensitivity to 10.sup.-13 atm cc s.sup.-1. The leak detection sensitivity is improved over conventional leak detectors by completely eliminating the use of o-rings, equipping the system with oil-free pumping systems, and by introducing measured flows of nitrogen at the entrances of both the turbo pump and backing pump to keep the system free of helium background. The addition of dry nitrogen flows to the system reduces backstreaming of atmospheric helium through the pumping system as a result of the limited compression ratios of the pumps for helium.

  10. High degree gravitational sensitivity from Mars orbiters for the GMM-1 gravity model

    NASA Technical Reports Server (NTRS)

    Lerch, F. J.; Smith, D. E.; Chan, J. C.; Patel, G. B.; Chinn, D. S.

    1994-01-01

    Orbital sensitivity of the gravity field for high degree terms (greater than 30) is analyzed on satellites employed in a Goddard Mars Model GMM-1, complete in spherical harmonics through degree and order 50. The model is obtained from S-band Doppler data on Mariner 9 (M9), Viking Orbiter 1 (VO1), and Viking Orbiter 2 (VO2) spacecraft, which were tracked by the NASA Deep Space Network on seven different highly eccentric orbits. The main sensitivity of the high degree terms is obtained from the VO1 and VO2 low orbits (300 km periapsis altitude), where significant spectral sensitivity is seen for all degrees out through degree 50. The velocity perturbations show a dominant effect at periapsis and significant effects out beyond the semi-latus rectum covering over 180 degrees of the orbital groundtrack for the low altitude orbits. Because of the wideband of periapsis motion covering nearly 180 degrees in w and +39 degrees in latitude coverage, the VO1 300 km periapsis altitude orbit with inclination of 39 degrees gave the dominant sensitivity in the GMM-1 solution for the high degree terms. Although the VO2 low periapsis orbit has a smaller band of periapsis mapping coverage, it strongly complements the VO1 orbit sensitivity for the GMM-1 solution with Doppler tracking coverage over a different inclination of 80 degrees.

  11. The Design and Optimization of a Highly Sensitive and Overload-Resistant Piezoresistive Pressure Sensor.

    PubMed

    Meng, Xiawei; Zhao, Yulong

    2016-03-09

    A piezoresistive pressure sensor with a beam-membrane-dual-island structure is developed for micro-pressure monitoring in the field of aviation, which requires great sensitivity and overload resistance capacity. The design, fabrication, and test of the sensor are presented in this paper. By analyzing the stress distribution of sensitive elements using the finite element method, a novel structure incorporating sensitive beams with a traditional bossed diaphragm is built up. The proposed structure proved to be advantageous in terms of high sensitivity and high overload resistance compared with the conventional bossed diaphragm and flat diaphragm structures. Curve fittings of surface stress and deflection based on ANSYS simulation results are performed to establish the sensor equations. Fabricated on an n-type single crystal silicon wafer, the sensor chips are wire-bonded to a printed circuit board (PCB) and packaged for experiments. The static and dynamic characteristics are tested and discussed. Experimental results show that the sensor has a sensitivity as high as 17.339 μV/V/Pa in the range of 500 Pa at room temperature, and a high overload resistance of 200 times overpressure. Due to the excellent performance, the sensor can be applied in measuring micro-pressure lower than 500 Pa.

  12. The Design and Optimization of a Highly Sensitive and Overload-Resistant Piezoresistive Pressure Sensor

    PubMed Central

    Meng, Xiawei; Zhao, Yulong

    2016-01-01

    A piezoresistive pressure sensor with a beam-membrane-dual-island structure is developed for micro-pressure monitoring in the field of aviation, which requires great sensitivity and overload resistance capacity. The design, fabrication, and test of the sensor are presented in this paper. By analyzing the stress distribution of sensitive elements using the finite element method, a novel structure incorporating sensitive beams with a traditional bossed diaphragm is built up. The proposed structure proved to be advantageous in terms of high sensitivity and high overload resistance compared with the conventional bossed diaphragm and flat diaphragm structures. Curve fittings of surface stress and deflection based on ANSYS simulation results are performed to establish the sensor equations. Fabricated on an n-type single crystal silicon wafer, the sensor chips are wire-bonded to a printed circuit board (PCB) and packaged for experiments. The static and dynamic characteristics are tested and discussed. Experimental results show that the sensor has a sensitivity as high as 17.339 μV/V/Pa in the range of 500 Pa at room temperature, and a high overload resistance of 200 times overpressure. Due to the excellent performance, the sensor can be applied in measuring micro-pressure lower than 500 Pa. PMID:27005627

  13. Highly sensitive glucose sensors based on enzyme-modified whole-graphene solution-gated transistors

    NASA Astrophysics Data System (ADS)

    Zhang, Meng; Liao, Caizhi; Mak, Chun Hin; You, Peng; Mak, Chee Leung; Yan, Feng

    2015-02-01

    Noninvasive glucose detections are convenient techniques for the diagnosis of diabetes mellitus, which require high performance glucose sensors. However, conventional electrochemical glucose sensors are not sensitive enough for these applications. Here, highly sensitive glucose sensors are successfully realized based on whole-graphene solution-gated transistors with the graphene gate electrodes modified with an enzyme glucose oxidase. The sensitivity of the devices is dramatically improved by co-modifying the graphene gates with Pt nanoparticles due to the enhanced electrocatalytic activity of the electrodes. The sensing mechanism is attributed to the reaction of H2O2 generated by the oxidation of glucose near the gate. The optimized glucose sensors show the detection limits down to 0.5 μM and good selectivity, which are sensitive enough for non-invasive glucose detections in body fluids. The devices show the transconductances two orders of magnitude higher than that of a conventional silicon field effect transistor, which is the main reason for their high sensitivity. Moreover, the devices can be conveniently fabricated with low cost. Therefore, the whole-graphene solution-gated transistors are a high-performance sensing platform for not only glucose detections but also many other types of biosensors that may find practical applications in the near future.

  14. Highly sensitive glucose sensors based on enzyme-modified whole-graphene solution-gated transistors.

    PubMed

    Zhang, Meng; Liao, Caizhi; Mak, Chun Hin; You, Peng; Mak, Chee Leung; Yan, Feng

    2015-02-06

    Noninvasive glucose detections are convenient techniques for the diagnosis of diabetes mellitus, which require high performance glucose sensors. However, conventional electrochemical glucose sensors are not sensitive enough for these applications. Here, highly sensitive glucose sensors are successfully realized based on whole-graphene solution-gated transistors with the graphene gate electrodes modified with an enzyme glucose oxidase. The sensitivity of the devices is dramatically improved by co-modifying the graphene gates with Pt nanoparticles due to the enhanced electrocatalytic activity of the electrodes. The sensing mechanism is attributed to the reaction of H2O2 generated by the oxidation of glucose near the gate. The optimized glucose sensors show the detection limits down to 0.5 μM and good selectivity, which are sensitive enough for non-invasive glucose detections in body fluids. The devices show the transconductances two orders of magnitude higher than that of a conventional silicon field effect transistor, which is the main reason for their high sensitivity. Moreover, the devices can be conveniently fabricated with low cost. Therefore, the whole-graphene solution-gated transistors are a high-performance sensing platform for not only glucose detections but also many other types of biosensors that may find practical applications in the near future.

  15. Design and Synthesis of an MOF Thermometer with High Sensitivity in the Physiological Temperature Range.

    PubMed

    Zhao, Dian; Rao, Xingtang; Yu, Jiancan; Cui, Yuanjing; Yang, Yu; Qian, Guodong

    2015-12-01

    An important result of research on mixed-lanthanide metal-organic frameworks (M'LnMOFs) is the realization of highly sensitive ratiometric luminescent thermometers. Here, we report the design and synthesis of the new M'LnMOF Tb0.80Eu0.20BPDA with high relative sensitivity in the physiological temperature regime (298-318 K). The emission intensity and luminescence lifetime were investigated and compared to those of existing materials. It was found that the temperature-dependent luminescence properties of Tb0.80Eu0.20BPDA are strongly associated with the distribution of the energy levels of the ligand. Such a property can be useful in the design of highly sensitive M'LnMOF thermometers.

  16. A highly sensitive CMOS digital Hall sensor for low magnetic field applications.

    PubMed

    Xu, Yue; Pan, Hong-Bin; He, Shu-Zhuan; Li, Li

    2012-01-01

    Integrated CMOS Hall sensors have been widely used to measure magnetic fields. However, they are difficult to work with in a low magnetic field environment due to their low sensitivity and large offset. This paper describes a highly sensitive digital Hall sensor fabricated in 0.18 μm high voltage CMOS technology for low field applications. The sensor consists of a switched cross-shaped Hall plate and a novel signal conditioner. It effectively eliminates offset and low frequency 1/f noise by applying a dynamic quadrature offset cancellation technique. The measured results show the optimal Hall plate achieves a high current related sensitivity of about 310 V/AT. The whole sensor has a remarkable ability to measure a minimum ± 2 mT magnetic field and output a digital Hall signal in a wide temperature range from -40 °C to 120 °C.

  17. A Highly Sensitive CMOS Digital Hall Sensor for Low Magnetic Field Applications

    PubMed Central

    Xu, Yue; Pan, Hong-Bin; He, Shu-Zhuan; Li, Li

    2012-01-01

    Integrated CMOS Hall sensors have been widely used to measure magnetic fields. However, they are difficult to work with in a low magnetic field environment due to their low sensitivity and large offset. This paper describes a highly sensitive digital Hall sensor fabricated in 0.18 μm high voltage CMOS technology for low field applications. The sensor consists of a switched cross-shaped Hall plate and a novel signal conditioner. It effectively eliminates offset and low frequency 1/f noise by applying a dynamic quadrature offset cancellation technique. The measured results show the optimal Hall plate achieves a high current related sensitivity of about 310 V/AT. The whole sensor has a remarkable ability to measure a minimum ±2 mT magnetic field and output a digital Hall signal in a wide temperature range from −40 °C to 120 °C. PMID:22438758

  18. Highly Sensitive and Reproducible SERS Performance from Uniform Film Assembled by Magnetic Noble Metal Composite Microspheres.

    PubMed

    Niu, Chunyu; Zou, Bingfang; Wang, Yongqiang; Cheng, Lin; Zheng, Haihong; Zhou, Shaomin

    2016-01-26

    To realize highly sensitive and reproducible SERS performance, a new route was put forward to construct uniform SERS film by using magnetic composite microspheres. In the experiment, monodisperse Fe3O4@SiO2@Ag microspheres with hierarchical surface were developed and used as building block of SERS substrate, which not only realized fast capturing analyte through dispersion and collection under external magnet but also could be built into uniform film through magnetically induced self-assembly. By using R6G as probe molecule, the as-obtained uniform film exhibited great improvement on SERS performance in both sensitivity and reproducibility when compared with nonuniform film, demonstrating the perfect integration of high sensitivity of hierarchal noble metal microspheres and high reproducibility of ordered microspheres array. Furthermore, the as-obtained product was used to detect pesticide thiram and also exhibited excellent SERS performance for trace detection.

  19. Periodically porous top electrodes on vertical nanowire arrays for highly sensitive gas detection.

    PubMed

    In, Hyun Jin; Field, Christopher R; Pehrsson, Pehr E

    2011-09-01

    Nanowires of various materials and configurations have been shown to be highly effective in the detection of chemical and biological species. In this paper, we report a novel, nanosphere-enabled approach to fabricating highly sensitive gas sensors based on ordered arrays of vertically aligned silicon nanowires topped with a periodically porous top electrode. The vertical array configuration helps to greatly increase the sensitivity of the sensor while the pores in the top electrode layer significantly improve sensing response times by allowing analyte gases to pass through freely. Herein, we show highly sensitive detection to both nitrogen dioxide (NO(2)) and ammonia (NH(3)) in humidified air. NO(2) detection down to 10 parts per billion (ppb) is demonstrated and an order-of-magnitude improvement in sensor response time is shown in the detection of NH(3).

  20. Photon Counting System for High-Sensitivity Detection of Bioluminescence at Optical Fiber End.

    PubMed

    Iinuma, Masataka; Kadoya, Yutaka; Kuroda, Akio

    2016-01-01

    The technique of photon counting is widely used for various fields and also applicable to a high-sensitivity detection of luminescence. Thanks to recent development of single photon detectors with avalanche photodiodes (APDs), the photon counting system with an optical fiber has become powerful for a detection of bioluminescence at an optical fiber end, because it allows us to fully use the merits of compactness, simple operation, highly quantum efficiency of the APD detectors. This optical fiber-based system also has a possibility of improving the sensitivity to a local detection of Adenosine triphosphate (ATP) by high-sensitivity detection of the bioluminescence. In this chapter, we are introducing a basic concept of the optical fiber-based system and explaining how to construct and use this system. PMID:27424915

  1. Photon Counting System for High-Sensitivity Detection of Bioluminescence at Optical Fiber End.

    PubMed

    Iinuma, Masataka; Kadoya, Yutaka; Kuroda, Akio

    2016-01-01

    The technique of photon counting is widely used for various fields and also applicable to a high-sensitivity detection of luminescence. Thanks to recent development of single photon detectors with avalanche photodiodes (APDs), the photon counting system with an optical fiber has become powerful for a detection of bioluminescence at an optical fiber end, because it allows us to fully use the merits of compactness, simple operation, highly quantum efficiency of the APD detectors. This optical fiber-based system also has a possibility of improving the sensitivity to a local detection of Adenosine triphosphate (ATP) by high-sensitivity detection of the bioluminescence. In this chapter, we are introducing a basic concept of the optical fiber-based system and explaining how to construct and use this system.

  2. Effects of intrinsic magnetostriction on tube-topology magnetoelectric sensors with high magnetic field sensitivity

    SciTech Connect

    Gillette, Scott M.; Fitchorov, Trifon; Obi, Ogheneyunume; Chen, Yajie Harris, Vincent G.; Jiang, Liping; Hao, Hongbo; Wu, Shuangxia

    2014-05-07

    Three quasi-one-dimensional magnetoelectric (ME) magnetic field sensors, each with a different magnetostrictive wire material, were investigated in terms of sensitivity and noise floor. Magnetostrictive Galfenol, iron-cobalt-vanadium, and iron-nickel wires were examined. Sensitivity profiles, hysteresis effects, and noise floor measurements for both optimally biased and zero-biased conditions are presented. The FeNi wire (FN) exhibits high sensitivity (5.36 mV/Oe) at bias fields below 22 Oe and an optimal bias of 10 Oe, whereas FeGa wire (FG) exhibits higher sensitivity (6.89 mW/Oe) at bias fields >22 Oe. The sensor of FeCoV wire (FC) presents relatively low sensitivity (2.12 mV/Oe), due to low magnetostrictive coefficient. Each ME tube-topology sensor demonstrates relatively high sensitivity at zero bias field, which results from a magnetic shape anisotropy and internal strain of the thin magnetostrictive wire.

  3. Effect of particle size in the TL response of natural quartz sensitized with high gamma dose

    NASA Astrophysics Data System (ADS)

    Carvalho, A. B., Jr.; Guzzo, P. L.; Sullasi, H. L.; Khoury, H. J.

    2010-11-01

    The aim of this study is to investigate the effect of particle size in the thermoluminescence (TL) response of natural quartz sensitized with high gamma dose. For this, fragments of a single crystal taken from the Solonópole district (Brazil) were crushed and classified into ten size fractions ranging from 38 μm to 5 mm. Aliquots of each size fraction were sensitized with 25 kGy of gamma dose of 60Co and heat-treated in a muffle furnace at 400oC. The non-sensitized samples were exposed to test doses between 50 Gy and 5 kGy and the sensitized samples were exposed to a unique test dose equal to 50 mGy. For non-sensitized samples, the TL peak near 325 °C increases with the particle size decreasing. However, in the case of sensitized samples, the TL output near 280 °C increases with the increasing of particle size up to mean grain size equal to 308 μm. Above 308 μm, an abrupt reduction in the TL intensity was noticed. These effects are discussed in relation to the specific surface area and the different interaction of high gamma doses with fine and coarse particles of quartz.

  4. Optical transitions in highly charged californium ions with high sensitivity to variation of the fine-structure constant.

    PubMed

    Berengut, J C; Dzuba, V A; Flambaum, V V; Ong, A

    2012-08-17

    We study electronic transitions in highly charged Cf ions that are within the frequency range of optical lasers and have very high sensitivity to potential variations in the fine-structure constant, α. The transitions are in the optical range despite the large ionization energies because they lie on the level crossing of the 5f and 6p valence orbitals in the thallium isoelectronic sequence. Cf(16+) is a particularly rich ion, having several narrow lines with properties that minimize certain systematic effects. Cf(16+) has very large nuclear charge and large ionization energy, resulting in the largest α sensitivity seen in atomic systems. The lines include positive and negative shifters.

  5. Optical Transitions in Highly Charged Californium Ions with High Sensitivity to Variation of the Fine-Structure Constant

    NASA Astrophysics Data System (ADS)

    Berengut, J. C.; Dzuba, V. A.; Flambaum, V. V.; Ong, A.

    2012-08-01

    We study electronic transitions in highly charged Cf ions that are within the frequency range of optical lasers and have very high sensitivity to potential variations in the fine-structure constant, α. The transitions are in the optical range despite the large ionization energies because they lie on the level crossing of the 5f and 6p valence orbitals in the thallium isoelectronic sequence. Cf16+ is a particularly rich ion, having several narrow lines with properties that minimize certain systematic effects. Cf16+ has very large nuclear charge and large ionization energy, resulting in the largest α sensitivity seen in atomic systems. The lines include positive and negative shifters.

  6. High-sensitivity strain sensor based on in-fiber rectangular air bubble.

    PubMed

    Liu, Shen; Yang, Kaiming; Wang, Yiping; Qu, Junle; Liao, Changrui; He, Jun; Li, Zhengyong; Yin, Guolu; Sun, Bing; Zhou, Jiangtao; Wang, Guanjun; Tang, Jian; Zhao, Jing

    2015-01-01

    We demonstrated a unique rectangular air bubble by means of splicing two sections of standard single mode fibers together and tapering the splicing joint. Such an air bubble can be used to develop a promising high-sensitivity strain sensor based on Fabry-Perot interference. The sensitivity of the strain sensor with a cavity length of about 61 μm and a wall thickness of about 1 μm was measured to be up to 43.0 pm/με and is the highest strain sensitivity among the in-fiber FPI-based strain sensors with air cavities reported so far. Moreover, our strain sensor has a very low temperature sensitivity of about 2.0 pm/°C. Thus, the temperature-induced strain measurement error is less than 0.046 με/°C. PMID:25557614

  7. High-Sensitivity X-ray Polarimetry with Amorphous Silicon Active-Matrix Pixel Proportional Counters

    NASA Technical Reports Server (NTRS)

    Black, J. K.; Deines-Jones, P.; Jahoda, K.; Ready, S. E.; Street, R. A.

    2003-01-01

    Photoelectric X-ray polarimeters based on pixel micropattern gas detectors (MPGDs) offer order-of-magnitude improvement in sensitivity over more traditional techniques based on X-ray scattering. This new technique places some of the most interesting astronomical observations within reach of even a small, dedicated mission. The most sensitive instrument would be a photoelectric polarimeter at the focus of 2 a very large mirror, such as the planned XEUS. Our efforts are focused on a smaller pathfinder mission, which would achieve its greatest sensitivity with large-area, low-background, collimated polarimeters. We have recently demonstrated a MPGD polarimeter using amorphous silicon thin-film transistor (TFT) readout suitable for the focal plane of an X-ray telescope. All the technologies used in the demonstration polarimeter are scalable to the areas required for a high-sensitivity collimated polarimeter. Leywords: X-ray polarimetry, particle tracking, proportional counter, GEM, pixel readout

  8. Real-Time, Single-Step Bioassay Using Nanoplasmonic Resonator With Ultra-High Sensitivity

    NASA Technical Reports Server (NTRS)

    Zhang, Xiang (Inventor); Ellman, Jonathan A. (Inventor); Chen, Fanqing Frank (Inventor); Su, Kai-Hang (Inventor); Wei, Qi-Huo (Inventor); Sun, Cheng (Inventor)

    2014-01-01

    A nanoplasmonic resonator (NPR) comprising a metallic nanodisk with alternating shielding layer(s), having a tagged biomolecule conjugated or tethered to the surface of the nanoplasmonic resonator for highly sensitive measurement of enzymatic activity. NPRs enhance Raman signals in a highly reproducible manner, enabling fast detection of protease and enzyme activity, such as Prostate Specific Antigen (paPSA), in real-time, at picomolar sensitivity levels. Experiments on extracellular fluid (ECF) from paPSA-positive cells demonstrate specific detection in a complex bio-fluid background in real-time single-step detection in very small sample volumes.

  9. Real-time, single-step bioassay using nanoplasmonic resonator with ultra-high sensitivity

    DOEpatents

    Zhang, Xiang; Ellman, Jonathan A; Chen, Fanqing Frank; Su, Kai-Hang; Wei, Qi-Huo; Sun, Cheng

    2014-04-01

    A nanoplasmonic resonator (NPR) comprising a metallic nanodisk with alternating shielding layer(s), having a tagged biomolecule conjugated or tethered to the surface of the nanoplasmonic resonator for highly sensitive measurement of enzymatic activity. NPRs enhance Raman signals in a highly reproducible manner, enabling fast detection of protease and enzyme activity, such as Prostate Specific Antigen (paPSA), in real-time, at picomolar sensitivity levels. Experiments on extracellular fluid (ECF) from paPSA-positive cells demonstrate specific detection in a complex bio-fluid background in real-time single-step detection in very small sample volumes.

  10. Formation of High-Purity Indium Oxide Nanoparticles and Their Application to Sensitive Detection of Ammonia.

    PubMed

    Bhardwaj, Sanjeev K; Bhardwaj, Neha; Kukkar, Manil; Sharma, Amit L; Kim, Ki-Hyun; Deep, Akash

    2015-01-01

    High-purity In₂O₃ nanoparticles were recovered from scrap indium tin oxide substrates in a stepwise process involving acidic leaching, liquid-liquid extraction with a phosphine oxide extractant, and combustion of the organic phase. The morphological and structural parameters of the recovered nanoparticles were investigated to support the formation of the desired products. These In₂O₃ nanoparticles were used for sensitive sensing of ammonia gas using a four-probe electrode device. The proposed sensor offered very quick response time (around 10 s) and highly sensitive detection of ammonia (at a detection limit of 1 ppm).

  11. Highly Sensitive Colorimetric Detection of Ochratoxin A by a Label-Free Aptamer and Gold Nanoparticles

    PubMed Central

    Luan, Yunxia; Chen, Jiayi; Li, Cheng; Xie, Gang; Fu, Hailong; Ma, Zhihong; Lu, Anxiang

    2015-01-01

    A label-free aptamer-based assay for the highly sensitive and specific detection of Ochratoxin A (OTA) was developed using a cationic polymer and gold nanoparticles (AuNPs). The OTA aptamer was used as a recognition element for the colorimetric detection of OTA based on the aggregation of AuNPs by the cationic polymer. By spectroscopic quantitative analysis, the colorimetric assay could detect OTA down to 0.009 ng/mL with high selectivity in the presence of other interfering toxins. This study offers a new alternative in visual detection methods that is rapid and sensitive for OTA detection. PMID:26690477

  12. A Hybrid LPG/CFBG for Highly Sensitive Refractive Index Measurements

    PubMed Central

    Sun, An; Wu, Zhishen

    2012-01-01

    A simple and high sensitive method employing a hybrid long period grating (LPG)/chirped fiber Bragg grating (CFBG) for refractive index (RI) measurements is proposed and investigated experimentally. The wide wavelength range of backward cladding modes are excited through the coupling and recoupling between LPG and CFBG. Experimental results indicate that the recoupled cladding modes between LPG and CFBG and core mode are modulated by the surrounding RI and highly sensitive RI measurements can be achieved by simply measuring the reflected intensity changes of the recoupled cladding modes and core mode. PMID:22969347

  13. Chemically attached gold nanoparticle-carbon nanotube hybrids for highly sensitive SERS substrate

    NASA Astrophysics Data System (ADS)

    Beqa, Lule; Singh, Anant Kumar; Fan, Zheng; Senapati, Dulal; Ray, Paresh Chandra

    2011-08-01

    Surface-enhanced Raman spectroscopy (SERS) has been shown as one of the most powerful analytical tool with high sensitivity. In this manuscript, we report the chemical design of SERS substrate, based on gold nanoparticles of different shapes-decorated with carbon nanotube with an enhancement factor of 7.5 × 1010. Shape dependent result shows that popcorn shape gold nanoparticle decorated SWCNT is the best choice for SERS substrate due to the existence of 'lightning rod effect' through several sharp edges or corners. Our results provide a good approach to develop highly sensitive SERS substrates and can help to improve the fundamental understanding of SERS phenomena.

  14. Formation of High-Purity Indium Oxide Nanoparticles and Their Application to Sensitive Detection of Ammonia

    PubMed Central

    Bhardwaj, Sanjeev K.; Bhardwaj, Neha; Kukkar, Manil; Sharma, Amit L.; Kim, Ki-Hyun; Deep, Akash

    2015-01-01

    High-purity In2O3 nanoparticles were recovered from scrap indium tin oxide substrates in a stepwise process involving acidic leaching, liquid-liquid extraction with a phosphine oxide extractant, and combustion of the organic phase. The morphological and structural parameters of the recovered nanoparticles were investigated to support the formation of the desired products. These In2O3 nanoparticles were used for sensitive sensing of ammonia gas using a four-probe electrode device. The proposed sensor offered very quick response time (around 10 s) and highly sensitive detection of ammonia (at a detection limit of 1 ppm). PMID:26694415

  15. Localized brain differences in Arc expression between mice showing low vs. high propensity to ethanol sensitization.

    PubMed

    Nona, Christina N; Lam, Marcus; Nobrega, José N

    2016-03-01

    Behavioral sensitization to ethanol (EtOH) manifests as a progressive and enduring increase in locomotor activity with repeated drug exposure. However, not all mice sensitize to EtOH and the neuronal mechanisms mediating vulnerability and resistance to EtOH sensitization remain unclear. We examined regional brain expression of the immediate early gene activity-regulated cytoskeleton-associated protein (Arc) in order to identify brain areas in which neuroplastic changes may contribute to the development and expression of EtOH sensitization. Male DBA/2J mice received 5 biweekly injections of EtOH (2.2g/kg, i.p.) or saline (SAL). They were categorized as high- (HS) or low-sensitized (LS) on the basis of final locomotor activity scores. In both LS and HS mice sacrificed after the last sensitization injection, Arc expression was decreased throughout the brain in comparison to SAL animals. A similar pattern was seen in mice sacrificed after an EtOH challenge two weeks after the last sensitization injection. However in this cohort, Arc expression was significantly increased in the central amygdala (CeA) in LS mice and in SAL mice receiving EtOH for the first time. No significant increases in Arc expression were seen in brains of sensitized (HS) animals. These results indicate an acute EtOH challenge results in different patterns of Arc expression in brains of LS, HS, and SAL mice. The dramatic increases in Arc expression in the CeA in LS and SAL mice showing little or no behavioral activation suggests that neural activity in this region may serve to inhibit the stimulant effects of EtOH. The observation that HS mice do not show increases in Arc expression with an EtOH challenge suggests the possibility that increased tolerance to the Arc-inducing effects of EtOH may be a factor in behavioral sensitization.

  16. Engineered nanoconstructs for the multiplexed and sensitive detection of high-risk pathogens

    NASA Astrophysics Data System (ADS)

    Seo, Youngmin; Kim, Ji-Eun; Jeong, Yoon; Lee, Kwan Hong; Hwang, Jangsun; Hong, Jongwook; Park, Hansoo; Choi, Jonghoon

    2016-01-01

    Many countries categorize the causative agents of severe infectious diseases as high-risk pathogens. Given their extreme infectivity and potential to be used as biological weapons, a rapid and sensitive method for detection of high-risk pathogens (e.g., Bacillus anthracis, Francisella tularensis, Yersinia pestis, and Vaccinia virus) is highly desirable. Here, we report the construction of a novel detection platform comprising two units: (1) magnetic beads separately conjugated with multiple capturing antibodies against four different high-risk pathogens for simple and rapid isolation, and (2) genetically engineered apoferritin nanoparticles conjugated with multiple quantum dots and detection antibodies against four different high-risk pathogens for signal amplification. For each high-risk pathogen, we demonstrated at least 10-fold increase in sensitivity compared to traditional lateral flow devices that utilize enzyme-based detection methods. Multiplexed detection of high-risk pathogens in a sample was also successful by using the nanoconstructs harboring the dye molecules with fluorescence at different wavelengths. We ultimately envision the use of this novel nanoprobe detection platform in future applications that require highly sensitive on-site detection of high-risk pathogens.

  17. A highly sensitive refractometric sensor based on cascaded SiN microring resonators.

    PubMed

    Zamora, Vanessa; Lützow, Peter; Weiland, Martin; Pergande, Daniel

    2013-01-01

    We investigate a highly sensitive optical sensor based on two cascaded microring resonators exploiting the Vernier effect. The architecture consists of two microrings with a slight difference in their free spectral ranges. This allows the generation of the Vernier effect for achieving ultra-high sensitivities. The sensor chip was fabricated using a silicon nitride platform and characterized with isopropanol/ethanol mixtures. A sensitivity of 0.95 nm/% was found for isopropanol concentrations in ethanol ranging from 0% to 10%. Furthermore, a collection of measurements was carried out using aqueous sodium chloride (NaCl) in solutions of different concentrations, confirming a high sensitivity of 10.3 nm/% and a bulk refractive index sensitivity of 6,317 nm/RIU. A limit of detection of 3.16 × 10(-6) RIU was determined. These preliminary results show the potential features of cascaded silicon nitride microring resonators for real-time and free-label monitoring of biomolecules for a broad range of applications. PMID:24169543

  18. In situ, high sensitivity, measurement of 90strontium in ground water using Cherenkov light

    NASA Astrophysics Data System (ADS)

    Bowyer, T. W.; Geelhood, B. D.; Hossbach, T. W.; Hansen, R.; Wilcox, W. A.

    2000-03-01

    The measurement of 90Sr in soils and ground water is important for characterization and remediation of radioactively contaminated sites. Measuring the 90Sr content to a few pCi/g of soil has been accomplished based on a design of scintillating fibers in a multilayered configuration measuring the high-energy beta emitted from 90Y decay (when in secular equilibrium with 90Sr), but has not been applied to water because the technique is sensitive to only the first few mm of soil. The volume of the source to which the detector is sensitive limits the theoretical sensitivity of such a detector, unless chemical preprocessing to strip the 90Sr from the water is performed. 90Sr activity in water can be quantified by detecting the high-energy beta particle by the Cherenkov light it produces when the high-energy beta from 90Y passes through the medium. We have used this phenomenon to sensitively measure 90Sr ( 90Y) from a volume of water large enough (765 cm 3) to make very sensitive measurements with short count times. For counting intervals of about 1000 s, we were able to achieve a minimum detectable concentration (MDC) (at 4.65 σ above background) of 14 pCi/L, and for 3000 s counts the MDC dropped to the drinking water limit of 8 pCi/L.

  19. High sensitivity to punishment and low impulsivity in obsessive-compulsive patients with hoarding symptoms.

    PubMed

    Fullana, Miquel Angel; Mataix-Cols, David; Caseras, Xavier; Alonso, Pino; Manuel Menchón, Josep; Vallejo, Julio; Torrubia, Rafael

    2004-11-30

    Recent factor-analytic studies involving over 2000 patients have reduced the symptoms of obsessive-compulsive disorder (OCD) into a few dimensions or potentially overlapping syndromes. Hoarding consistently emerged as a separate factor in all these studies. This study investigated the relationship between OCD symptom dimensions and normal personality traits in a sample of 56 OCD patients. They were administered the Sensitivity to Punishment and Sensitivity to Reward Questionnaire and the Eysenck Personality Questionnaire, derived from Gray's and Eysenck's personality models, respectively. The personality scores were correlated with previously identified symptom dimensions from the Yale-Brown Obsessive-Compulsive Scale Symptom Checklist (Y-BOCS-SC), controlling for overall illness severity. High scores on the hoarding dimension of the Y-BOCS-SC were positively correlated with scores on the Sensitivity to Punishment scale and negatively with Eysenck's Psychoticism scale. While high sensitivity to punishment is a personality feature common to many OCD patients, it is more strongly pronounced in patients with hoarding symptoms. These patients also appear to be less impulsive or novelty seeking as reflected by low scores on Eysenck's Psychoticism scale. High sensitivity to punishment and low novelty seeking in OCD hoarders might explain their poor compliance and response to conventional treatments, but this question needs to be explored further in a prospective treatment study.

  20. A Highly Sensitive Refractometric Sensor Based on Cascaded SiN Microring Resonators

    PubMed Central

    Zamora, Vanessa; Lützow, Peter; Weiland, Martin; Pergande, Daniel

    2013-01-01

    We investigate a highly sensitive optical sensor based on two cascaded microring resonators exploiting the Vernier effect. The architecture consists of two microrings with a slight difference in their free spectral ranges. This allows the generation of the Vernier effect for achieving ultra-high sensitivities. The sensor chip was fabricated using a silicon nitride platform and characterized with isopropanol/ethanol mixtures. A sensitivity of 0.95 nm/% was found for isopropanol concentrations in ethanol ranging from 0% to 10%. Furthermore, a collection of measurements was carried out using aqueous sodium chloride (NaCl) in solutions of different concentrations, confirming a high sensitivity of 10.3 nm/% and a bulk refractive index sensitivity of 6,317 nm/RIU. A limit of detection of 3.16 × 10−6 RIU was determined. These preliminary results show the potential features of cascaded silicon nitride microring resonators for real-time and free-label monitoring of biomolecules for a broad range of applications. PMID:24169543

  1. A highly sensitive refractometric sensor based on cascaded SiN microring resonators.

    PubMed

    Zamora, Vanessa; Lützow, Peter; Weiland, Martin; Pergande, Daniel

    2013-01-01

    We investigate a highly sensitive optical sensor based on two cascaded microring resonators exploiting the Vernier effect. The architecture consists of two microrings with a slight difference in their free spectral ranges. This allows the generation of the Vernier effect for achieving ultra-high sensitivities. The sensor chip was fabricated using a silicon nitride platform and characterized with isopropanol/ethanol mixtures. A sensitivity of 0.95 nm/% was found for isopropanol concentrations in ethanol ranging from 0% to 10%. Furthermore, a collection of measurements was carried out using aqueous sodium chloride (NaCl) in solutions of different concentrations, confirming a high sensitivity of 10.3 nm/% and a bulk refractive index sensitivity of 6,317 nm/RIU. A limit of detection of 3.16 × 10(-6) RIU was determined. These preliminary results show the potential features of cascaded silicon nitride microring resonators for real-time and free-label monitoring of biomolecules for a broad range of applications.

  2. Development and validation of sensitive LC-MS/MS assays for quantification of HP-β-CD in human plasma and CSF

    PubMed Central

    Jiang, Hui; Sidhu, Rohini; Fujiwara, Hideji; De Meulder, Marc; de Vries, Ronald; Gong, Yong; Kao, Mark; Porter, Forbes D.; Yanjanin, Nicole M.; Carillo-Carasco, Nuria; Xu, Xin; Ottinger, Elizabeth; Woolery, Myra; Ory, Daniel S.; Jiang, Xuntian

    2014-01-01

    2-Hydroxypropyl-β-cyclodextrin (HP-β-CD), a widely used excipient for drug formulation, has emerged as an investigational new drug for the treatment of Niemann-Pick type C1 (NPC1) disease, a neurodegenerative cholesterol storage disorder. Development of a sensitive quantitative LC-MS/MS assay to monitor the pharmacokinetics (PKs) of HP-β-CD required for clinical trials has been challenging owing to the dispersity of the HP-β-CD. To support a phase 1 clinical trial for ICV delivery of HP-β-CD in NPC1 patients, novel methods for quantification of HP-β-CD in human plasma and cerebrospinal fluid (CSF) using LC-MS/MS were developed and validated: a 2D-LC-in-source fragmentation-MS/MS (2D-LC-IF-MS/MS) assay and a reversed phase ultra performance LC-MS/MS (RP-UPLC-MS/MS) assay. In both assays, protein precipitation and “dilute and shoot” procedures were used to process plasma and CSF, respectively. The assays were fully validated and in close agreement, and allowed determination of PK parameters for HP-β-CD. The LC-MS/MS methods are ∼100-fold more sensitive than the current HPLC assay, and were successfully employed to analyze HP-β-CD in human plasma and CSF samples to support the phase 1 clinical trial of HP-β-CD in NPC1 patients. PMID:24868096

  3. A novel light tracing system with high-precision and high-sensitivity sensors setup

    NASA Astrophysics Data System (ADS)

    Lin, Chern-Sheng; Wu, Pin Yi; Tsai, Jen Min; Tseng, Yu Hung; Chen, Hsin-Hung; Hwang, Jiann-Lih

    2013-11-01

    This paper presents a novel light source tracing system, which is comprised of a light-tracing board, with four photo-sensors of different incline angles, correspondingly disposed on its four edges, which are adjustable according to the movement range of the light source in order to achieve light-tracing purposes. This system introduces the algorithm of four-edge-sensors with servo motors in each site to improve sensor's sensitivity. The measurement values of light perception can be feedback to the programmable logic controller by wireless transceiver module. After proportional-integral-derivative operation, the system can obtain the situation of light source. In a normal mode, the light source movement range is large, the range of the incline angle of the light sensors are also set to large to obtain wide detection angle. But in a locking mode, the incline angle of the light sensing plane decreases, thus, the measurement range reduces, and the sensitivity is higher.

  4. High sensitivity refractive index sensor based on adiabatic tapered optical fiber deposited with nanofilm by ALD.

    PubMed

    Zhu, Shan; Pang, Fufei; Huang, Sujuan; Zou, Fang; Dong, Yanhua; Wang, Tingyun

    2015-06-01

    Atomic layer deposition (ALD) technology is introduced to fabricate a high sensitivity refractive index sensor based on an adiabatic tapered optical fiber. Different thickness of Al2O3 nanofilm is coated around fiber taper precisely and uniformly under different deposition cycles. Attributed to the high refractive index of the Al2O3 nanofilm, an asymmetry Fabry-Perot like interferometer is constructed along the fiber taper. Based on the ray-optic analysis, total internal reflection happens on the nanofilm-surrounding interface. With the ambient refractive index changing, the phase delay induced by the Goos-Hänchen shift is changed. Correspondingly, the transmission resonant spectrum shifts, which can be utilized for realizing high sensitivity sensor. The high sensitivity sensor with 6008 nm/RIU is demonstrated by depositing 3000 layers Al2O3 nanofilm as the ambient refractive index is close to 1.33. This high sensitivity refractive index sensor is expected to have wide applications in biochemical sensors.

  5. High sensitivity refractive index sensor based on adiabatic tapered optical fiber deposited with nanofilm by ALD.

    PubMed

    Zhu, Shan; Pang, Fufei; Huang, Sujuan; Zou, Fang; Dong, Yanhua; Wang, Tingyun

    2015-06-01

    Atomic layer deposition (ALD) technology is introduced to fabricate a high sensitivity refractive index sensor based on an adiabatic tapered optical fiber. Different thickness of Al2O3 nanofilm is coated around fiber taper precisely and uniformly under different deposition cycles. Attributed to the high refractive index of the Al2O3 nanofilm, an asymmetry Fabry-Perot like interferometer is constructed along the fiber taper. Based on the ray-optic analysis, total internal reflection happens on the nanofilm-surrounding interface. With the ambient refractive index changing, the phase delay induced by the Goos-Hänchen shift is changed. Correspondingly, the transmission resonant spectrum shifts, which can be utilized for realizing high sensitivity sensor. The high sensitivity sensor with 6008 nm/RIU is demonstrated by depositing 3000 layers Al2O3 nanofilm as the ambient refractive index is close to 1.33. This high sensitivity refractive index sensor is expected to have wide applications in biochemical sensors. PMID:26072758

  6. The nature and nurture of high IQ: an extended sensitive period for intellectual development.

    PubMed

    Brant, Angela M; Munakata, Yuko; Boomsma, Dorret I; Defries, John C; Haworth, Claire M A; Keller, Matthew C; Martin, Nicholas G; McGue, Matthew; Petrill, Stephen A; Plomin, Robert; Wadsworth, Sally J; Wright, Margaret J; Hewitt, John K

    2013-08-01

    IQ predicts many measures of life success, as well as trajectories of brain development. Prolonged cortical thickening observed in individuals with high IQ might reflect an extended period of synaptogenesis and high environmental sensitivity or plasticity. We tested this hypothesis by examining the timing of changes in the magnitude of genetic and environmental influences on IQ as a function of IQ score. We found that individuals with high IQ show high environmental influence on IQ into adolescence (resembling younger children), whereas individuals with low IQ show high heritability of IQ in adolescence (resembling adults), a pattern consistent with an extended sensitive period for intellectual development in more-intelligent individuals. The pattern held across a cross-sectional sample of almost 11,000 twin pairs and a longitudinal sample of twins, biological siblings, and adoptive siblings.

  7. Highly sensitive liquid level monitoring system utilizing polymer fiber Bragg gratings.

    PubMed

    Marques, Carlos A F; Peng, Gang-Ding; Webb, David J

    2015-03-01

    A novel and highly sensitive liquid level sensor based on a polymer optical fiber Bragg grating (POFBG) is experimentally demonstrated. Two different configurations are studied and both configurations show the potential to interrogate liquid level by measuring the strain induced in a POFBG embedded in a silicone rubber diaphragm, which deforms due to hydrostatic pressure variations. The sensor exhibits a highly linear response over the sensing range and a good repeatability. For comparison, a similar sensor using a FBG inscribed in silica fiber is fabricated, which displays a sensitivity that is a factor of 5 smaller than the POFBG. The temperature sensitivity is studied and a novel multi-sensor arrangement proposed which has the potential to provide level readings independent of temperature and the liquid density. PMID:25836830

  8. Highly Sensitive and Fast Anion-Selective InN Quantum Dot Electrochemical Sensors

    NASA Astrophysics Data System (ADS)

    Hassan Alvi, Naveed ul; Rodriguez, Paul E. D. Soto; Gómez, Victor J.; Kumar, Praveen; Willander, Magnus; Nötzel, Richard

    2013-11-01

    Epitaxial InN quantum dots (QDs) are demonstrated as ion-selective electrode for potentiometric anion concentration measurements. The sensor reveals high sensitivity above 90 mV/decade for the detection of chlorine and hydroxyl ions in sodium chloride (NaCl), calcium chloride (CaCl2), and sodium hydroxide (NaOH) solutions. The response time is less than two seconds after which the signal is very stable and repeatable. The sensitivity for the InN QDs is about two times that for a reference InN thin film and the response time is about five times shorter. In pH buffer solutions the sensor reveals no clear response to cations. A model is presented for the high sensitivity, fast response, and ion selectivity based on the unique electronic properties of the InN surface together with the zero-dimensional nature of the QDs.

  9. A Highly Sensitive Fiber Optic Sensor Based on Two-Core Fiber for Refractive Index Measurement

    PubMed Central

    Guzmán-Sepúlveda, José Rafael; Guzmán-Cabrera, Rafael; Torres-Cisneros, Miguel; Sánchez-Mondragón, José Javier; May-Arrioja, Daniel Alberto

    2013-01-01

    A simple and compact fiber optic sensor based on a two-core fiber is demonstrated for high-performance measurements of refractive indices (RI) of liquids. In order to demonstrate the suitability of the proposed sensor to perform high-sensitivity sensing in a variety of applications, the sensor has been used to measure the RI of binary liquid mixtures. Such measurements can accurately determine the salinity of salt water solutions, and detect the water content of adulterated alcoholic beverages. The largest sensitivity of the RI sensor that has been experimentally demonstrated is 3,119 nm per Refractive Index Units (RIU) for the RI range from 1.3160 to 1.3943. On the other hand, our results suggest that the sensitivity can be enhanced up to 3485.67 nm/RIU approximately for the same RI range. PMID:24152878

  10. A highly sensitive pressure sensor using conductive composite elastomers with wavy structures

    NASA Astrophysics Data System (ADS)

    Sun, Rujie; Zhang, Xiao-Chong; Rossiter, Jonathan; Scarpa, Fabrizio

    2016-05-01

    Flexible pressure sensors are crucial components for the next generation wearable devices to monitor human physiological conditions. In this paper, we present a novel resistive pressure sensor based on hybrid composites made from carbon nanotube (CNT) for the conductive coating layer and polydimethylsiloxane (PDMS) elastomers as the substrate. The high sensitivity of these sensors is attributed to the change of contact resistance caused by the variation of the contact areas between the wavy film and the electrodes. Porous electrodes were designed to increase the roughness of the interfaces, thus further enhancing the pressure sensitivity. The developed device was verified through a series of tests, and the sensor exhibited a high sensitivity of 2.05 kPa-1 under a low pressure of 35.6 Pa.

  11. Mesoporous structured MIPs@CDs fluorescence sensor for highly sensitive detection of TNT.

    PubMed

    Xu, Shoufang; Lu, Hongzhi

    2016-11-15

    A facile strategy was developed to prepare mesoporous structured molecularly imprinted polymers capped carbon dots (M-MIPs@CDs) fluorescence sensor for highly sensitive and selective determination of TNT. The strategy using amino-CDs directly as "functional monomer" for imprinting simplify the imprinting process and provide well recognition sites accessibility. The as-prepared M-MIPs@CDs sensor, using periodic mesoporous silica as imprinting matrix, and amino-CDs directly as "functional monomer", exhibited excellent selectivity and sensitivity toward TNT with detection limit of 17nM. The recycling process was sustainable for 10 times without obvious efficiency decrease. The feasibility of the developed method in real samples was successfully evaluated through the analysis of TNT in soil and water samples with satisfactory recoveries of 88.6-95.7%. The method proposed in this work was proved to be a convenient and practical way to prepare high sensitive and selective fluorescence MIPs@CDs sensors. PMID:27315521

  12. Highly sensitive determination of DAO activity by oxidation of a luminescence reagent.

    PubMed

    Mayer, I; Pittner, F; Hermann, M; Missbichler, A

    2007-11-01

    A highly sensitive method for measuring the activity of the enzyme diamine oxidase (DAO) independent of the type of substrate is described. The principle of the assay is to determine the amount hydrogen peroxide generated as a reaction product during oxidation of diamines by DAO. PSatto, a highly sensitive luminescence reagent, was used to generate a signal depending on the hydrogen peroxide concentration based on the action of horseradish peroxidase. DAO is specifically captured from a sample by an antibody immobilized to microwell plates, and the substrate is added to the bound enzyme. Various diamines were used as substrates; the peroxide produced is directly proportional to the amount of DAO bound to the specific antibodies. With this very sensitive method, it is possible to detect pmol amounts of generated hydrogen peroxide in plasma matrix corresponding to the biological activity of DAO.

  13. High IgE sensitization to maize and rice pollen in the highlands of Madagascar

    PubMed Central

    Ramavovololona; Sénéchal, Hélène; Andrianarisoa, Ange; Rakotoarimanana, Vololona; Godfrin, Dominique; Peltre, Gabriel; Poncet, Pascal; Sutra, Jean-Pierre

    2014-01-01

    Introduction Maize and rice are two crops constituting the main food supply in many under-developed and developing countries. Despite the large area devoted to the culture, the sensitization to the pollen from these plants is reported to be low and often considered as an occupational allergy. Methods Sixty five Malagasy pollen allergic patients were clinically and immunochemically investigated with regard to maize and rice pollen allergens. Pollen extracts were electrophoretically separated in 1 and 2 dimensions and IgE and IgG reactivities detected upon immunoblotting. Results When exploring the sensitization profile of Malagasy allergic patients to maize and rice pollen, it appears that a high proportion of these patients consulting during grass pollinating season were sensitized to both pollen as revealed by skin prick testing (62 vs. 59%) and IgE immunoblotting (85 vs. 40%). Several clinically relevant allergens were recognized by patients’ serum IgE in maize and rice pollen extracts. Conclusion The high levels of maize and rice pollen sensitization should be related, in this tropical region, to a specific environmental exposure including i) a proximity of the population to the allergenic sources and ii) a putative exacerbating effect of a highly polluted urban atmosphere on pollen allergenicity. Cross-reactivities between wild and cultivated grasses and also between rice and maize pollen are involved as well as some specific maize sensitizations. The presence of dense urban and peri-urban agriculture, in various African regions and worldwide, could be a high environmental risk factor for people sensitive to maize pollen. PMID:25870739

  14. High-frequency stimulation of the hippocampus blocks fear learning sensitization and return of extinguished fear.

    PubMed

    Deschaux, O; Koumar, O-C; Canini, F; Moreau, J-L; Garcia, R

    2015-02-12

    Patients with post-traumatic stress disorder (PTSD) present hippocampal (HPC) dysfunction, which may facilitate fear-related phenomena such as fear learning sensitization (i.e. potentiation of fear acquisition by initial fear conditioning (FC1)) and fear return (i.e. reactivation of extinguished fear). Fear return is sensitive to HPC high-frequency stimulation (HFS) in rats. The goal of the present study was to examine whether fear learning sensitization is also sensitive to HPC HFS in rats. We found in control conditions that, after FC1 (with 15 shock administrations) and extinction, conditioning in a different context with one shock administration was potentiated (proactive effect) and associated with fear return in the initial context (retroactive effect). Both phenomena were prevented by HPC HFS applied before the second conditioning. We also found that the effect of HPC HFS on fear learning sensitization required initial extinction. These findings suggest a pivotal role of the HPC in preventing proactive and retroactive effects of successive fear conditionings. These data also support the concept that HPC deactivation may be involved in fear learning sensitization and fear return in PTSD patients.

  15. Niacin Skin Sensitivity Is Increased in Adolescents at Ultra-High Risk for Psychosis

    PubMed Central

    Schäfer, Miriam R.; Milleit, Berko; Langbein, Kerstin; Hipler, Uta-Christina; Milleit, Christine; Klier, Claudia M.; Schlögelhofer, Monika; Holub, Magdalena; Holzer, Ingrid; Berk, Michael; McGorry, Patrick D.; Sauer, Heinrich; Amminger, G. Paul

    2016-01-01

    Background Most studies provide evidence that the skin flush response to nicotinic acid (niacin) stimulation is impaired in schizophrenia. However, only little is known about niacin sensitivity in the ultra-high risk (UHR) phase of psychotic disorders. Methods We compared visual ratings of niacin sensitivity between adolescents at UHR for psychosis according to the one year transition outcome (UHR-T n = 11; UHR-NT n = 55) with healthy controls (HC n = 25) and first episode schizophrenia patients (FEP n = 25) treated with atypical antipsychotics. Results Contrary to our hypothesis niacin sensitivity of the entire UHR group was not attenuated, but significantly increased compared to the HC group, whereas no difference could be found between the UHR-T and UHR-NT groups. As expected, niacin sensitivity of FEP was attenuated compared to HC group. In UHR individuals niacin sensitivity was inversely correlated with omega-6 and -9 fatty acids (FA), but positively correlated with phospholipase A2 (inPLA2) activity, a marker of membrane lipid repair/remodelling. Conclusions Increased niacin sensitivity in UHR states likely indicates an impaired balance of eicosanoids and omega-6/-9 FA at a membrane level. Our findings suggest that the emergence of psychosis is associated with an increased mobilisation of eicosanoids prior to the transition to psychosis possibly reflecting a “pro-inflammatory state”, whereas thereafter eicosanoid mobilisation seems to be attenuated. Potential treatment implications for the UHR state should be further investigated. PMID:26894921

  16. Millimeter wave broadband high sensitivity detectors with zero-bias Schottky diodes

    NASA Astrophysics Data System (ADS)

    Changfei, Yao; Ming, Zhou; Yunsheng, Luo; Conghai, Xu

    2015-06-01

    Two broadband detectors at W-band and D-band are analyzed and designed with low barrier Schottky diodes. The input circuit of the detectors is realized by low and high impedance microstrip lines, and their output circuit is composed of a radio frequency (RF) bandstop filter and a tuning line for optimum reflection phase of the RF signal. S-parameters of the complete circuit are exported to a circuit simulator for voltage sensitivity analysis. For the W band detectors, the highest measured voltage sensitivity is 11800 mV/mW at 100 GHz, and the sensitivity is higher than 2000 mV/mW in 80-104 GHz. Measured tangential sensitivity (TSS) is higher than —38 dBm, and its linearity is superior than 0.99992 at 95 GHz. For the D band detector, the highest measured voltage sensitivity is 1600 mV/mW, and the typical sensitivity is 600 mV/mW in 110-170 GHz. TSS is higher than -29 dBm, and its linearity is superior than 0.99961 at 150 GHz.

  17. Highly Sensitive PCR Assay for Routine Diagnosis of African Swine Fever Virus in Clinical Samples

    PubMed Central

    Agüero, M.; Fernández, J.; Romero, L.; Sánchez Mascaraque, C.; Arias, M.; Sánchez-Vizcaíno, J. M.

    2003-01-01

    This work provides a novel, highly sensitive, hot start PCR method for rapid and specific detection of African swine fever virus (ASFV) that can be used as a routine diagnostic test for ASFV in surveillance, control, and eradication programs. A confirmatory test of the specificity of this method based on restriction endonuclease analysis was also developed. PMID:12958285

  18. Carbonized Silk Fabric for Ultrastretchable, Highly Sensitive, and Wearable Strain Sensors.

    PubMed

    Wang, Chunya; Li, Xiang; Gao, Enlai; Jian, Muqiang; Xia, Kailun; Wang, Qi; Xu, Zhiping; Ren, Tianling; Zhang, Yingying

    2016-08-01

    A carbonized plain-weave silk fabric is fabricated into wearable and robust strain sensors, which can be stretched up to 500% and show high sensitivity in a wide strain range. This sensor can be assembled into wearable devices for detection of both large and subtle human activities, showing great potential for monitoring human motions and personal health.

  19. A Highly Sensitive Diketopyrrolopyrrole-Based Ambipolar Transistor for Selective Detection and Discrimination of Xylene Isomers.

    PubMed

    Wang, Bin; Huynh, Tan-Phat; Wu, Weiwei; Hayek, Naseem; Do, Thu Trang; Cancilla, John C; Torrecilla, Jose S; Nahid, Masrur Morshed; Colwell, John M; Gazit, Oz M; Puniredd, Sreenivasa Reddy; McNeill, Christopher R; Sonar, Prashant; Haick, Hossam

    2016-06-01

    An ambipolar poly(diketopyrrolopyrrole-terthiophene)-based field-effect transistor (FET) sensitively detects xylene isomers at low ppm levels with multiple sensing features. Combined with pattern-recognition algorithms, a sole ambipolar FET sensor, rather than arrays of sensors, can discriminate highly similar xylene structural isomers from one another. PMID:26996398

  20. Constructing a High-Sensitivity, Computer-Interfaced, Differential Thermal Analysis Device for Teaching and Research

    ERIC Educational Resources Information Center

    Martinez, L. M.; Videa, M.; Mederos, F.; Mesquita, J.

    2007-01-01

    The construction of a new highly-sensitive, computer-interfaced, differential thermal analysis (DTA) device, used for gathering different information about the chemical reactions, is described. The instrument provides a better understanding about the phase transitions, phase diagrams and many more concepts to the students.