Stimulus selection and tracking during urination: autoshaping directed behavior with toilet targets.

PubMed

Siegel, R K

1977-01-01

A simple procedure is described for investigating stimuli selected as targets during urination in the commode. Ten normal males preferred a floating target that could be tracked to a series of stationary targets. This technique was used to bring misdirected urinations in a severely retarded male under rapid stimulus control of a floating target in the commode. The float stimulus was also evaluated with nine institionalized, moderately retarded males and results indicated rapid autoshaping of directed urination without the use of verbal instructions or conventional toilet training. The technique can be applied in training children to control misdirected urinations in institution for the retarded, in psychiatric wards with regressed populations, and in certain male school dormitories.

Use of Cdse/ZnS quantum dots for sensitive detection and quantification of paraquat in water samples.

PubMed

Durán, Gema M; Contento, Ana M; Ríos, Ángel

2013-11-01

Based on the highly sensitive fluorescence change of water-soluble CdSe/ZnS core-shell quantum dots (QD) by paraquat herbicide, a simple, rapid and reproducible methodology was developed to selectively determine paraquat (PQ) in water samples. The methodology enabled the use of simple pretreatment procedure based on the simple water solubilization of CdSe/ZnS QDs with hydrophilic heterobifunctional thiol ligands, such as 3-mercaptopropionic acid (3-MPA), using microwave irradiation. The resulting water-soluble QDs exhibit a strong fluorescence emission at 596 nm with a high and reproducible photostability. The proposed analytical method thus satisfies the need for a simple, sensible and rapid methodology to determine residues of paraquat in water samples, as required by the increasingly strict regulations for health protection introduced in recent years. The sensitivity of the method, expressed as detection limits, was as low as 3.0 ng L(-1). The lineal range was between 10-5×10(3) ng L(-1). RSD values in the range of 71-102% were obtained. The analytical applicability of proposed method was demonstrated by analyzing water samples from different procedence. Copyright © 2013 Elsevier B.V. All rights reserved.

Nanofabrication

DOEpatents

Tuominen, Mark; Bal, Mustafa; Russell, Thomas P.; Ursache, Andrei

2007-03-13

Pathways to rapid and reliable fabrication of three-dimensional nanostructures are provided. Simple methods are described for the production of well-ordered, multilevel nanostructures. This is accomplished by patterning block copolymer templates with selective exposure to a radiation source. The resulting multi-scale lithographic template can be treated with post-fabrication steps to produce multilevel, three-dimensional, integrated nanoscale media, devices, and systems.

[Selective arteriography of the supra-aortic trunks by right humeral approach with a 4F catheter].

PubMed

Rodde, A; Bazin, C; Blum, A; Boccaccini, H; Boyer, B; Claudon, M; Regent, D

1993-12-01

Three hundred and sixty seven patients were studied for cerebrovascular disease with intra-arterial digital subtraction. Examination were performed using a right transbrachial approach with a 4F catheter. Selective catheterization of the carotid arteries was possible in 98% for the left and 99% for the right. Image quality was consistently good or excellent. There was 2 neurologic complications and 1 local complication (hematoma) requiring surgery few weeks later. Selective carotid and vertebral catheterizations by the brachial route is safe, simple, accurate and rapid (15 mn) and can be employed in outpatients.

Construction of a simple optical sensor based on air stable lipid film with incorporated urease for the rapid detection of urea in milk.

PubMed

Nikoleli, Georgia-Paraskevi; Nikolelis, Dimitrios P; Methenitis, Constantinos

2010-08-18

This work describes the construction of a simple optical sensor for the rapid, selective and sensitive detection of urea in milk using air stable lipid films with incorporated urease. The lipid film is stabilized on a glass filter by polymerization using UV (ultra-violet) radiation prior its use. Methacrylic acid was the functional monomer, ethylene glycol dimethacrylate was the crosslinker and 2,2'-azobis-(2-methylpropionitrile) was the initiator. Urease is incorporated within this mixture prior to the polymerization. The presence of the enzyme in these films quenched this fluorescence and the colour became similar to that of the filters without the lipid films. A drop of aqueous solution of urea provided a "switching on" of the fluorescence which allows the rapid detection of this compound at the levels of 10(-8) M concentrations. The investigation of the effect of potent interferences included a wide range of compounds usually found in foods and also of proteins and lipids. These lipid membranes were used for the rapid detection of urea in milk. Copyright 2010 Elsevier B.V. All rights reserved.

Simple and rapid mercury ion selective electrode based on 1-undecanethiol assembled Au substrate and its recognition mechanism.

PubMed

Li, Xian-Qing; Liang, Hai-Qing; Cao, Zhong; Xiao, Qing; Xiao, Zhong-Liang; Song, Liu-Bin; Chen, Dan; Wang, Fu-Liang

2017-03-01

A simple and rapid mercury ion selective electrode based on 1-undecanethiol (1-UDT) assembled Au substrate (Au/1-UDT) has been well constructed. 1-UDT was for the purpose of generating self-assembled monolayer on gold surface to recognize Hg 2+ in aqueous solution, which had a working concentration range of 1.0×10 -8 -1.0×10 -4 molL -1 , with a Nernst response slope of 28.83±0.4mV/-pC, a detection limit of 4.5×10 -9 molL -1 , and a good selectivity over the other tested cations. Also, the Au/1-UDT possessed good reproducibility, stability, and short response time. The recovery obtained for the determination of mercury ion in practical tremella samples was in the range of 99.8-103.4%. Combined electrochemical analysis and X-ray photoelectron spectroscopy (XPS) with quantum chemical computation, the probable recognition mechanism of the electrode for selective recognition of Hg 2+ has been investigated. The covalent bond formed between mercury and sulfur is stronger than the one between gold and sulfur and thus prevents the adsorption of 1-UDT molecules on the gold surface. The quantum chemical computation with density functional theory further demonstrates that the strong interaction between the mercury atom and the sulfur atom on the gold surface leads to the gold sulfur bond ruptured and the gold mercury metallophilic interaction. Copyright © 2016 Elsevier B.V. All rights reserved.

Simple and rapid quantification of brominated vegetable oil in commercial soft drinks by LC–MS

PubMed Central

Chitranshi, Priyanka; da Costa, Gonçalo Gamboa

2016-01-01

We report here a simple and rapid method for the quantification of brominated vegetable oil (BVO) in soft drinks based upon liquid chromatography–electrospray ionization mass spectrometry. Unlike previously reported methods, this novel method does not require hydrolysis, extraction or derivatization steps, but rather a simple “dilute and shoot” sample preparation. The quantification is conducted by mass spectrometry in selected ion recording mode and a single point standard addition procedure. The method was validated in the range of 5–25 μg/mL BVO, encompassing the legal limit of 15 μg/mL established by the US FDA for fruit-flavored beverages in the US market. The method was characterized by excellent intra- and inter-assay accuracy (97.3–103.4%) and very low imprecision [0.5–3.6% (RSD)]. The direct nature of the quantification, simplicity, and excellent statistical performance of this methodology constitute clear advantages in relation to previously published methods for the analysis of BVO in soft drinks. PMID:27451219

Isocratic non-aqueous reversed-phase high-performance liquid chromatographic separation of capsanthin and capsorubin in red peppers (Capsicum annuum L.), paprika and oleoresin.

PubMed

Weissenberg, M; Schaeffler, I; Menagem, E; Barzilai, M; Levy, A

1997-01-03

A simple, rapid high-performance liquid chromatography method has been devised in order to separate and quantify the xanthophylls capsorubin and capasanthin present in red pepper (Capsicum annuum L.) fruits and preparations made from them (paprika and oleoresin). A reversed-phase isocratic non-aqueous system allows the separation of xanthophylls within a few minutes, with detection at 450 nm, using methyl red as internal standard to locate the various carotenoids and xanthophylls found in plant extracts. The selection of extraction solvents, mild saponification conditions, and chromatographic features is evaluated and discussed. The method is proposed for rapid screening of large plant populations, plant selection, as well as for paprika products and oleoresin, and also for nutrition and quality control studies.

Rapid Data Delivery System (RDDS)

USGS Publications Warehouse

Cress, Jill J.; Goplen, Susan E.

2007-01-01

Since the start of the active 2000 summer fire season, the U. S. Geological Survey (USGS) Rocky Mountain Geographic Science Center (RMGSC) has been actively engaged in providing crucial and timely support to Federal, State, and local natural hazards monitoring, analysis, response, and recovery activities. As part of this support, RMGSC has developed the Rapid Data Delivery System (RDDS) to provide emergency and incident response teams with timely access to geospatial data. The RDDS meets these needs by combining a simple web-enabled data viewer for the selection and preview of vector and raster geospatial data with an easy to use data ordering form. The RDDS viewer also incorporates geospatial locations for current natural hazard incidents, including wildfires, earthquakes, hurricanes, and volcanoes, allowing incident responders to quickly focus on their area of interest for data selection.

Guiding Students to the Right Questions: Adaptive Navigation Support in an E-Learning System for Java Programming

ERIC Educational Resources Information Center

Hsiao, I.-H.; Sosnovsky, S.; Brusilovsky, P.

2010-01-01

Rapid growth of the volume of interactive questions available to the students of modern E-Learning courses placed the problem of personalized guidance on the agenda of E-Learning researchers. Without proper guidance, students frequently select too simple or too complicated problems and ended either bored or discouraged. This paper explores a…

A simple and rapid creatinine sensing via DLS selectivity, using calix[4]arene thiol functionalized gold nanoparticles.

PubMed

Sutariya, Pinkesh G; Pandya, Alok; Lodha, Anand; Menon, Shobhana K

2016-01-15

A new, simple, ultra-sensitive and selective approach has been reported for the "on spot" colorimetric detection of creatinine based on calix[4]arene functionalized gold nanoparticles (AuNPs) with excellent discrimination in the presence of other biomolecules. The lower detection limit of the method is 2.16nM. The gold nanoparticles and p-tert-butylcalix[4]arene were synthesized by microwave assisted method. Specifically, in our study, we used dynamic light scattering (DLS) which is a powerful method for the determination of small changes in particle size, improved selectivity and sensitivity of the creatinine detection system over colorimetric method. The nanoassembly is characterized by Transmission electron microscopy (TEM), DLS, UV-vis and ESI-MS spectroscopy, which demonstrates the binding affinity due its ability of hydrogen bonding and electrostatic interaction between -NH group of creatinine and pSDSC4. It exhibits fast response time (<60s) to creatinine and has long shelf-life (>5 weeks). The developed pSDSC4-AuNPs based creatinine biosensor will be established as simple, reliable and accurate tool for the determination of creatinine in human urine samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Ruthenium-Catalyzed Cascade Annulation of Indole with Propargyl Alcohols.

PubMed

Kaufmann, Julia; Jäckel, Elisabeth; Haak, Edgar

2018-05-14

Cascade transformations forming multiple bonds and one-pot procedures provide rapid access to natural-product-like scaffolds from simple precursors. These atom-economic processes are valuable tools in organic synthesis and drug discovery. Herein, we report on ruthenium-catalyzed cascade annulations of indole with readily available propargyl alcohols. These provide rapid access to diverse carbazoles, cyclohepta[b]indoles, and further fused polycycles with high selectivity. A bifunctional ruthenium complex featuring a redox-coupled cyclopentadienone ligand acts as a common catalyst for the different cascade processes. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Genome complexity, robustness and genetic interactions in digital organisms

NASA Astrophysics Data System (ADS)

Lenski, Richard E.; Ofria, Charles; Collier, Travis C.; Adami, Christoph

1999-08-01

Digital organisms are computer programs that self-replicate, mutate and adapt by natural selection. They offer an opportunity to test generalizations about living systems that may extend beyond the organic life that biologists usually study. Here we have generated two classes of digital organism: simple programs selected solely for rapid replication, and complex programs selected to perform mathematical operations that accelerate replication through a set of defined `metabolic' rewards. To examine the differences in their genetic architecture, we introduced millions of single and multiple mutations into each organism and measured the effects on the organism's fitness. The complex organisms are more robust than the simple ones with respect to the average effects of single mutations. Interactions among mutations are common and usually yield higher fitness than predicted from the component mutations assuming multiplicative effects; such interactions are especially important in the complex organisms. Frequent interactions among mutations have also been seen in bacteria, fungi and fruitflies. Our findings support the view that interactions are a general feature of genetic systems.

Genome complexity, robustness and genetic interactions in digital organisms.

PubMed

Lenski, R E; Ofria, C; Collier, T C; Adami, C

1999-08-12

Digital organisms are computer programs that self-replicate, mutate and adapt by natural selection. They offer an opportunity to test generalizations about living systems that may extend beyond the organic life that biologists usually study. Here we have generated two classes of digital organism: simple programs selected solely for rapid replication, and complex programs selected to perform mathematical operations that accelerate replication through a set of defined 'metabolic' rewards. To examine the differences in their genetic architecture, we introduced millions of single and multiple mutations into each organism and measured the effects on the organism's fitness. The complex organisms are more robust than the simple ones with respect to the average effects of single mutations. Interactions among mutations are common and usually yield higher fitness than predicted from the component mutations assuming multiplicative effects; such interactions are especially important in the complex organisms. Frequent interactions among mutations have also been seen in bacteria, fungi and fruitflies. Our findings support the view that interactions are a general feature of genetic systems.

Biocatalytic site- and enantioselective oxidative dearomatization of phenols

NASA Astrophysics Data System (ADS)

Baker Dockrey, Summer A.; Lukowski, April L.; Becker, Marc R.; Narayan, Alison R. H.

2018-02-01

The biocatalytic transformations used by chemists are often restricted to simple functional-group interconversions. In contrast, nature has developed complexity-generating biocatalytic reactions within natural product pathways. These sophisticated catalysts are rarely employed by chemists, because the substrate scope, selectivity and robustness of these catalysts are unknown. Our strategy to bridge the gap between the biosynthesis and synthetic chemistry communities leverages the diversity of catalysts available within natural product pathways. Here we show that, starting from a suite of biosynthetic enzymes, catalysts with complementary substrate scope as well as selectivity can be identified. This strategy has been applied to the oxidative dearomatization of phenols, a chemical transformation that rapidly builds molecular complexity from simple starting materials and cannot be accomplished with high selectivity using existing catalytic methods. Using enzymes from biosynthetic pathways, we have successfully developed a method to produce ortho-quinol products with controlled site- and stereoselectivity. Furthermore, we have capitalized on the scalability and robustness of this method in gram-scale reactions as well as multi-enzyme and chemoenzymatic cascades.

Preferentially Oriented Ag Nanocrystals with Extremely High Activity and Faradaic Efficiency for CO2 Electrochemical Reduction to CO.

PubMed

Peng, Xiong; Karakalos, Stavros G; Mustain, William E

2018-01-17

Selective electrochemical reduction of CO 2 is one of the most important processes to study because of its promise to convert this greenhouse gas to value-added chemicals at low cost. In this work, a simple anodization treatment was devised that first oxidizes Ag to Ag 2 CO 3 , then uses rapid electrochemical reduction to create preferentially oriented nanoparticles (PONs) of metallic Ag (PON-Ag) with high surface area as well as high activity and very high selectivity for the reduction of CO 2 to CO. The PON-Ag catalyst was dominated by (110) and (100) orientation, which allowed PON-Ag to achieve a CO Faradaic efficiency of 96.7% at an operating potential of -0.69 V vs RHE. This performance is not only significantly higher than that of polycrystalline Ag (60% at -0.87 V vs RHE) but also represents one of the best combinations of activity and selectivity achieved to date - all with a very simple, scalable approach to electrode fabrication.

Rapid Detection of Positive Selection in Genes and Genomes Through Variation Clusters

PubMed Central

Wagner, Andreas

2007-01-01

Positive selection in genes and genomes can point to the evolutionary basis for differences among species and among races within a species. The detection of positive selection can also help identify functionally important protein regions and thus guide protein engineering. Many existing tests for positive selection are excessively conservative, vulnerable to artifacts caused by demographic population history, or computationally very intensive. I here propose a simple and rapid test that is complementary to existing tests and that overcomes some of these problems. It relies on the null hypothesis that neutrally evolving DNA regions should show a Poisson distribution of nucleotide substitutions. The test detects significant deviations from this expectation in the form of variation clusters, highly localized groups of amino acid changes in a coding region. In applying this test to several thousand human–chimpanzee gene orthologs, I show that such variation clusters are not generally caused by relaxed selection. They occur in well-defined domains of a protein's tertiary structure and show a large excess of amino acid replacement over silent substitutions. I also identify multiple new human–chimpanzee orthologs subject to positive selection, among them genes that are involved in reproductive functions, immune defense, and the nervous system. PMID:17603100

Synthesis of renewable diesel through hydrodeoxygenation reaction from nyamplung oil (Calophyllum Inophyllum oil) using NiMo/Z and NiMo/C catalysts with rapid heating and cooling method

NASA Astrophysics Data System (ADS)

Susanto, B. H.; Prakasa, M. B.; Shahab, M. H.

2016-11-01

The synthesis of metal nanocrystal was conducted by modification preparation from simple heating method which heating and cooling process run rapidly. The result of NiMo/Z 575 °C characterizations are 33.73 m2/gram surface area and 31.80 nm crystal size. By used NiMo/C 700 °C catalyst for 30 minutes which had surface area of 263.21 m2/gram, had 31.77 nm crystal size, and good morphology, obtained catalyst with high activity, selectivity, and stability. After catalyst activated, synthesis of renewable diesel performed in hydrogenation reactor at 375 °C, 12 bar, and 800 rpm. The result of conversion was 81.99%, yield was 68.08%, and selectivity was 84.54%.

Highly selective colorimetric bacteria sensing based on protein-capped nanoparticles.

PubMed

Qiu, Suyan; Lin, Zhenyu; Zhou, Yaomin; Wang, Donggen; Yuan, Lijuan; Wei, Yihua; Dai, Tingcan; Luo, Linguang; Chen, Guonan

2015-02-21

A rapid and cost-effective colorimetric sensor has been developed for the detection of bacteria (Bacillus subtilis was selected as an example). The sensor was designed to rely on lysozyme-capped AuNPs with the advantages of effective amplification and high specificity. In the sensing system, lysozyme was able to bind strongly to Bacillus subtilis, which effectively induced a color change of the solution from light purple to purplish red. The lowest concentration of Bacillus subtilis detectable by the naked eye was 4.5 × 10(3) colony-forming units (CFU) mL(-1). Similar results were discernable from UV-Vis absorption measurements. A good specificity was observed through a statistical analysis method using the SPSS software (version 17.0). This simple colorimetric sensor may therefore be a rapid and specific method for a bacterial detection assay in complex samples.

Advances in developing rapid, reliable and portable detection systems for alcohol.

PubMed

Thungon, Phurpa Dema; Kakoti, Ankana; Ngashangva, Lightson; Goswami, Pranab

2017-11-15

Development of portable, reliable, sensitive, simple, and inexpensive detection system for alcohol has been an instinctive demand not only in traditional brewing, pharmaceutical, food and clinical industries but also in rapidly growing alcohol based fuel industries. Highly sensitive, selective, and reliable alcohol detections are currently amenable typically through the sophisticated instrument based analyses confined mostly to the state-of-art analytical laboratory facilities. With the growing demand of rapid and reliable alcohol detection systems, an all-round attempt has been made over the past decade encompassing various disciplines from basic and engineering sciences. Of late, the research for developing small-scale portable alcohol detection system has been accelerated with the advent of emerging miniaturization techniques, advanced materials and sensing platforms such as lab-on-chip, lab-on-CD, lab-on-paper etc. With these new inter-disciplinary approaches along with the support from the parallel knowledge growth on rapid detection systems being pursued for various targets, the progress on translating the proof-of-concepts to commercially viable and environment friendly portable alcohol detection systems is gaining pace. Here, we summarize the progress made over the years on the alcohol detection systems, with a focus on recent advancement towards developing portable, simple and efficient alcohol sensors. Copyright © 2017 Elsevier B.V. All rights reserved.

A highly selective and sensitive fluorescent chemosensor and its application for rapid on-site detection of Al3 +

NASA Astrophysics Data System (ADS)

Yue, Xiao-li; Wang, Zhao-qing; Li, Chao-rui; Yang, Zheng-yin

2018-03-01

In this paper, a simple naphthalene-based derivative (HL) has been designed and synthesized as a Al3 +-selective fluorescent chemosensor based on the PET mechanism. HL exhibited high selectivity and sensitivity towards Al3 + over other commonly coexisting metal ions in ethanol with a detection limit of 2.72 nM. The 1:1 binding stoichiometry of the complex (HL-Al3 +) was determined from the Job's plot based on fluorescence titrations and the ESI-MS spectrum data. Moreover, the binding site of HL with Al3 + was assured by the 1H NMR titration experiment. The binding constant (Ka) of the complex (HL-Al3 +) was calculated to be 5.06 × 104 M- 1 according to the Benesi-Hildebrand equation. In addition, the recognizing process of HL towards Al3 + was chemically reversible by adding Na2EDTA. Importantly, HL could directly and rapidly detect aluminum ion through the filter paper without resorting to additional instrumental analysis.

Slide-and-exchange mechanism for rapid and selective transport through the nuclear pore complex.

PubMed

Raveh, Barak; Karp, Jerome M; Sparks, Samuel; Dutta, Kaushik; Rout, Michael P; Sali, Andrej; Cowburn, David

2016-05-03

Nucleocytoplasmic transport is mediated by the interaction of transport factors (TFs) with disordered phenylalanine-glycine (FG) repeats that fill the central channel of the nuclear pore complex (NPC). However, the mechanism by which TFs rapidly diffuse through multiple FG repeats without compromising NPC selectivity is not yet fully understood. In this study, we build on our recent NMR investigations showing that FG repeats are highly dynamic, flexible, and rapidly exchanging among TF interaction sites. We use unbiased long timescale all-atom simulations on the Anton supercomputer, combined with extensive enhanced sampling simulations and NMR experiments, to characterize the thermodynamic and kinetic properties of FG repeats and their interaction with a model transport factor. Both the simulations and experimental data indicate that FG repeats are highly dynamic random coils, lack intrachain interactions, and exhibit significant entropically driven resistance to spatial confinement. We show that the FG motifs reversibly slide in and out of multiple TF interaction sites, transitioning rapidly between a strongly interacting state and a weakly interacting state, rather than undergoing a much slower transition between strongly interacting and completely noninteracting (unbound) states. In the weakly interacting state, FG motifs can be more easily displaced by other competing FG motifs, providing a simple mechanism for rapid exchange of TF/FG motif contacts during transport. This slide-and-exchange mechanism highlights the direct role of the disorder within FG repeats in nucleocytoplasmic transport, and resolves the apparent conflict between the selectivity and speed of transport.

A simple and rapid ultra-high-performance liquid chromatography-tandem mass spectrometry method to determine plasma biotin in hemodialysis patients.

PubMed

Yagi, Shigeaki; Nishizawa, Manabu; Ando, Itiro; Oguma, Shiro; Sato, Emiko; Imai, Yutaka; Fujiwara, Masako

2016-08-01

A simple, rapid, and selective method for determination of plasma biotin was developed using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). After single-step protein precipitation with methanol, biotin and stable isotope-labeled biotin as an internal standard (IS) were chromatographed on a pentafluorophenyl stationary-phase column (2.1 × 100 mm, 2.7 μm) under isocratic conditions using 10 mm ammonium formate-acetonitrile (93:7, v/v) at a flow rate of 0.6 mL/min. The total chromatographic runtime was 5 min for each injection. Detection was performed in a positive electrospray ionization mode by monitoring selected ion transitions at m/z 245.1/227.0 and 249.1/231.0 for biotin and the IS, respectively. The calibration curve was linear in the range of 0.05-2 ng/mL using 300 μL of plasma. The intra- and inter-day precisions were all <7.1%. The accuracy varied from -0.7 to 8.2%. The developed UHPLC-MS/MS method was successfully applied to determine plasma biotin concentrations in hemodialysis patients. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Molecularly imprinted polymer cartridges coupled on-line with high performance liquid chromatography for simple and rapid analysis of dextromethorphan in human plasma samples.

PubMed

Moein, Mohammad Mahdi; Javanbakht, Mehran; Akbari-Adergani, Behrouz

2011-04-01

In this paper, a novel method is described for automated determination of dextromethorphan in biological fluids using molecularly imprinted solid-phase extraction (MISPE) as a sample clean-up technique combined with high performance liquid chromatography (HPLC). The water-compatible molecularly imprinted polymers (MIPs) were prepared using methacrylic acid as functional monomer, ethylene glycol dimethacrylate as cross-linker, chloroform as porogen and dextromethorphan as template molecule. These imprinted polymers were used as solid-phase extraction sorbent for the extraction of dextromethorphan from human plasma samples. Various parameters affecting the extraction efficiency of the MIP cartridges were evaluated. The high selectivity of the sorbent coupled to the high performance liquid chromatographic system permitted a simple and rapid analysis of this drug in plasma samples with limits of detection (LOD) and quantification (LOQ) of 0.12 ng/mL and 0.35 ng/mL, respectively. The MIP selectivity was evaluated by analyzing of the dextromethorphan in presence of several substances with similar molecular structures and properties. Results from the HPLC analyses showed that the recoveries of dextromethorphan using MIP cartridges from human plasma samples in the range of 1-50 ng/mL were higher than 87%. Copyright © 2011 Elsevier B.V. All rights reserved.

Simple and rapid detection of the porcine reproductive and respiratory syndrome virus from pig whole blood using filter paper.

PubMed

Inoue, Ryo; Tsukahara, Takamitsu; Sunaba, Chinatsu; Itoh, Mitsugi; Ushida, Kazunari

2007-04-01

The combination of Flinders Technology Associates filter papers (FTA cards) and real-time PCR was examined to establish a simple and rapid technique for the detection of porcine reproductive and respiratory syndrome virus (PRRSV) from whole pig blood. A modified live PRRS vaccine was diluted with either sterilised saline or pig whole blood, and the suspensions were applied onto the FTA cards. The real-time RT-PCR detection of PRRSV was performed directly with the samples applied to the FTA card without the RNA extraction step. Six whole blood samples from at random selected piglets in the PRRSV infected farm were also assayed in this study. The expected PCR product was successfully amplified from either saline diluted or pig whole blood diluted vaccine. The same PCR ampliocon was detected from all blood samples assayed in this study. This study suggested that the combination of an FTA card and real-time PCR is a rapid and easy technique for the detection of PRRSV. This technique can remarkably shorten the time required for PRRSV detection from whole blood and makes the procedure much easier.

Micropropagation of African violet (Saintpaulia ionantha Wendl.).

PubMed

Shukla, Mukund; Sullivan, J Alan; Jain, Shri Mohan; Murch, Susan J; Saxena, Praveen K

2013-01-01

Micropropagation is an important tool for rapid multiplication and the creation of genetic variability in African violets (Saintpaulia ionantha Wendl.). Successful in vitro propagation depends on the specific requirements and precise manipulation of various factors such as the type of explants used, physiological state of the mother plant, plant growth regulators in the culture medium, and growth conditions. Development of cost-effective protocols with a high rate of multiplication is a crucial requirement for commercial application of micropropagation. The current chapter describes an optimized protocol for micropropagation of African violets using leaf explants obtained from in vitro grown plants. In this process, plant regeneration occurs via both somatic embryogenesis and shoot organogenesis simultaneously in the explants induced with the growth regulator thidiazuron (TDZ; N-phenyl-N'-1,2,3-thidiazol-5-ylurea). The protocol is simple, rapid, and efficient for large-scale propagation of African violet and the dual routes of regeneration allow for multiple applications of the technology from simple clonal propagation to induction or selection of variants to the production of synthetic seeds.

Evaluation of the antioxidant power of honey, propolis and royal jelly by amperometric flow injection analysis.

PubMed

Buratti, S; Benedetti, S; Cosio, M S

2007-02-28

In this paper is described the applicability of a flow injection system, operating with an amperometric detector, for measurement in rapid and simple way the antioxidant power of honey, propolis and royal jelly. The proposed method evaluates the reducing power of selected antioxidant compounds and does not require the use of free radicals or oxidants. Twelve honey, 12 propolis and 4 royal jelly samples of different botanical and geographical origin were evaluated by the electrochemical method and the data were compared with those obtained by the DPPH assay. Since a good correlation was found (R(2)=0.92) the proposed electrochemical method can be successfully employed for the direct, rapid and simple monitoring of the antioxidant power of honeybee products. Furthermore, the total phenolic content of samples was determined by the Folin-Ciocalteau procedure and the characteristic antioxidant activities showed a good correlation with phenolics (R(2)=0.96 for propolis and 0.90 for honey).

Comparative Validation of the Determination of Sofosbuvir in Pharmaceuticals by Several Inexpensive Ecofriendly Chromatographic, Electrophoretic, and Spectrophotometric Methods.

PubMed

El-Yazbi, Amira F

2017-07-01

Sofosbuvir (SOFO) was approved by the U.S. Food and Drug Administration in 2013 for the treatment of hepatitis C virus infection with enhanced antiviral potency compared with earlier analogs. Notwithstanding, all current editions of the pharmacopeias still do not present any analytical methods for the quantification of SOFO. Thus, rapid, simple, and ecofriendly methods for the routine analysis of commercial formulations of SOFO are desirable. In this study, five accurate methods for the determination of SOFO in pharmaceutical tablets were developed and validated. These methods include HPLC, capillary zone electrophoresis, HPTLC, and UV spectrophotometric and derivative spectrometry methods. The proposed methods proved to be rapid, simple, sensitive, selective, and accurate analytical procedures that were suitable for the reliable determination of SOFO in pharmaceutical tablets. An analysis of variance test with P-value > 0.05 confirmed that there were no significant differences between the proposed assays. Thus, any of these methods can be used for the routine analysis of SOFO in commercial tablets.

Combinatorial microfluidic droplet engineering for biomimetic material synthesis

PubMed Central

Bawazer, Lukmaan A.; McNally, Ciara S.; Empson, Christopher J.; Marchant, William J.; Comyn, Tim P.; Niu, Xize; Cho, Soongwon; McPherson, Michael J.; Binks, Bernard P.; deMello, Andrew; Meldrum, Fiona C.

2016-01-01

Although droplet-based systems are used in a wide range of technologies, opportunities for systematically customizing their interface chemistries remain relatively unexplored. This article describes a new microfluidic strategy for rapidly tailoring emulsion droplet compositions and properties. The approach uses a simple platform for screening arrays of droplet-based microfluidic devices and couples this with combinatorial selection of the droplet compositions. Through the application of genetic algorithms over multiple screening rounds, droplets with target properties can be rapidly generated. The potential of this method is demonstrated by creating droplets with enhanced stability, where this is achieved by selecting carrier fluid chemistries that promote titanium dioxide formation at the droplet interfaces. The interface is a mixture of amorphous and crystalline phases, and the resulting composite droplets are biocompatible, supporting in vitro protein expression in their interiors. This general strategy will find widespread application in advancing emulsion properties for use in chemistry, biology, materials, and medicine. PMID:27730209

Rapid prototyping of 2D glass microfluidic devices based on femtosecond laser assisted selective etching process

NASA Astrophysics Data System (ADS)

Kim, Sung-Il; Kim, Jeongtae; Koo, Chiwan; Joung, Yeun-Ho; Choi, Jiyeon

2018-02-01

Microfluidics technology which deals with small liquid samples and reagents within micro-scale channels has been widely applied in various aspects of biological, chemical, and life-scientific research. For fabricating microfluidic devices, a silicon-based polymer, PDMS (Polydimethylsiloxane), is widely used in soft lithography, but it has several drawbacks for microfluidic applications. Glass has many advantages over PDMS due to its excellent optical, chemical, and mechanical properties. However, difficulties in fabrication of glass microfluidic devices that requires multiple skilled steps such as MEMS technology taking several hours to days, impedes broad application of glass based devices. Here, we demonstrate a rapid and optical prototyping of a glass microfluidic device by using femtosecond laser assisted selective etching (LASE) and femtosecond laser welding. A microfluidic droplet generator was fabricated as a demonstration of a microfluidic device using our proposed prototyping. The fabrication time of a single glass chip containing few centimeter long and complex-shaped microfluidic channels was drastically reduced in an hour with the proposed laser based rapid and simple glass micromachining and hermetic packaging technique.

Facile fabrication of networked patterns and their superior application to realize the virus immobilized networked pattern circuit.

PubMed

Choi, Kyung Min; Lee, Seok Jae; Choi, Jung Hoon; Park, Tae Jung; Park, Jong Wan; Shin, Weon Ho; Kang, Jeung Ku

2010-12-07

A facile route to fabricate a protein-immobilized network pattern circuit for rapid and highly sensitive diagnosis was developed via the evaporation directed impromptu patterning method and selective avian influenza virus (AIV) immobilization. The response to the 10 fg mL(-1) anti-AI antibody demonstrates that this easy and simple circuit has about 1000 times higher sensitivity compared to those of conventional approaches.

Rapid quantification of iodopropynyl butylcarbamate as the preservative in cosmetic formulations using high-performance liquid chromatography-electrospray mass spectrometry.

PubMed

Frauen, M; Steinhart, H; Rapp, C; Hintze, U

2001-07-01

A simple, rapid and reproducible method for identification and quantification of iodopropynyl butylcarbamate (IPBC) in different cosmetic formulations is presented. The determination was carried out using a high-performance liquid chromatography (HPLC) procedure on a reversed phase column coupled to a single quadrupole mass spectrometer (MS) via an electrospray ionization (ESI) interface. Detection was performed in the positive selected ion-monitoring mode. In methanol/water extracts from different cosmetic formulations a detection limit between 50 and 100 ng/g could be achieved. A routine analytical procedure could be set up with good quantification reliability (relative standard deviation between 0.9 and 2.9%).

Rapid phenolic O-glycosylation of small molecules and complex unprotected peptides in aqueous solvent

NASA Astrophysics Data System (ADS)

Wadzinski, Tyler J.; Steinauer, Angela; Hie, Liana; Pelletier, Guillaume; Schepartz, Alanna; Miller, Scott J.

2018-06-01

Glycosylated natural products and synthetic glycopeptides represent a significant and growing source of biochemical probes and therapeutic agents. However, methods that enable the aqueous glycosylation of endogenous amino acid functionality in peptides without the use of protecting groups are scarce. Here, we report a transformation that facilitates the efficient aqueous O-glycosylation of phenolic functionality in a wide range of small molecules, unprotected tyrosine, and tyrosine residues embedded within a range of complex, fully unprotected peptides. The transformation, which uses glycosyl fluoride donors and is promoted by Ca(OH)2, proceeds rapidly at room temperature in water, with good yields and selective formation of unique anomeric products depending on the stereochemistry of the glycosyl donor. High functional group tolerance is observed, and the phenol glycosylation occurs selectively in the presence of virtually all side chains of the proteinogenic amino acids with the singular exception of Cys. This method offers a highly selective, efficient, and operationally simple approach for the protecting-group-free synthesis of O-aryl glycosides and Tyr-O-glycosylated peptides in water.

A simple rhodamine hydrazide-based turn-on fluorescent probe for HOCl detection.

PubMed

Zhang, Zhen; Zou, Yuan; Deng, Chengquan; Meng, Liesu

2016-06-01

Hypochlorous acid (HOCl) plays a crucial role in daily life and mediates a variety of physiological processes, however, abnormal levels of HOCl have been associated with numerous human diseases. It is therefore of significant interest to establish a simple, selective, rapid and sensitive fluorogenic method for the detection of HOCl in environmental and biological samples. A hydrazide-containing fluorescent probe based on a rhodamine scaffold was facilely developed that could selectively detect HOCl over other biologically relevant reactive oxygen species, reactive nitrogen species and most common metal ions in vitro. Via an irreversible oxidation-hydrolysis mechanism, and upon HOCl-triggered opening of the intramolecular spirocyclic ring during detection, the rhodamine hydrazide-based probe exhibited large fluorescence enhancement in the emission spectra with a fast response, low detection limit and comparatively wide pH detection range in aqueous media. The probe was further successfully applied to monitoring trace HOCl in tap water and imaging both exogenous and endogenous HOCl within living cells. It is anticipated that this simple and useful probe might be an efficient tool with which to facilitate more HOCl-related chemical and biological research. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Rapid enzyme immunoassay for determination of toxigenicity among clinical isolates of corynebacteria.

PubMed

Engler, K H; Efstratiou, A

2000-04-01

A rapid enzyme immunoassay (EIA) was developed for the phenotypic detection of diphtheria toxin among clinical isolates of corynebacteria. The assay uses equine polyclonal antitoxin as the capture antibody and an alkaline phosphatase-labeled monoclonal antibody, specific for fragment A of the toxin molecule, as the detecting antibody. The assay is rapid, sensitive, and specific: a final result is available within 3 h of colony selection, and the limits of detection are 0.1 ng of pure diphtheria toxin/ml. Toxigenicity could be detected with isolates grown on a diverse range of culture media, including selective agars. Toxin detection using the EIA was compared to that with the Elek test and PCR detection of fragment A of the diphtheria toxin (tox) gene, using 245 isolates of corynebacteria. The results for the EIA were in complete concordance with those of the Elek test: 87 toxigenic and 158 nontoxigenic isolates. Ten of the phenotypically nontoxigenic strains were found to contain fragment A of the tox gene but did not express the toxin protein. These isolates were found to be nontoxigenic in the Vero cell tissue culture cytotoxicity assay and were therefore nontoxigenic for diagnostic purposes. The EIA is a simple rapid phenotypic test which provides a definitive result on toxigenicity within one working day.

Rapid Enzyme Immunoassay for Determination of Toxigenicity among Clinical Isolates of Corynebacteria

PubMed Central

Engler, Kathryn H.; Efstratiou, Androulla

2000-01-01

A rapid enzyme immunoassay (EIA) was developed for the phenotypic detection of diphtheria toxin among clinical isolates of corynebacteria. The assay uses equine polyclonal antitoxin as the capture antibody and an alkaline phosphatase-labeled monoclonal antibody, specific for fragment A of the toxin molecule, as the detecting antibody. The assay is rapid, sensitive, and specific: a final result is available within 3 h of colony selection, and the limits of detection are 0.1 ng of pure diphtheria toxin/ml. Toxigenicity could be detected with isolates grown on a diverse range of culture media, including selective agars. Toxin detection using the EIA was compared to that with the Elek test and PCR detection of fragment A of the diphtheria toxin (tox) gene, using 245 isolates of corynebacteria. The results for the EIA were in complete concordance with those of the Elek test: 87 toxigenic and 158 nontoxigenic isolates. Ten of the phenotypically nontoxigenic strains were found to contain fragment A of the tox gene but did not express the toxin protein. These isolates were found to be nontoxigenic in the Vero cell tissue culture cytotoxicity assay and were therefore nontoxigenic for diagnostic purposes. The EIA is a simple rapid phenotypic test which provides a definitive result on toxigenicity within one working day. PMID:10747112

A paper-based cantilever array sensor: Monitoring volatile organic compounds with naked eye.

PubMed

Fraiwan, Arwa; Lee, Hankeun; Choi, Seokheun

2016-09-01

Volatile organic compound (VOC) detection is critical for controlling industrial and commercial emissions, environmental monitoring, and public health. Simple, portable, rapid and low-cost VOC sensing platforms offer the benefits of on-site and real-time monitoring anytime and anywhere. The best and most practically useful approaches to monitoring would include equipment-free and power-free detection by the naked eye. In this work, we created a novel, paper-based cantilever sensor array that allows simple and rapid naked-eye VOC detection without the need for power, electronics or readout interface/equipment. This simple VOC detection method was achieved using (i) low-cost paper materials as a substrate and (ii) swellable thin polymers adhered to the paper. Upon exposure to VOCs, the polymer swelling adhered to the paper-based cantilever, inducing mechanical deflection that generated a distinctive composite pattern of the deflection angles for a specific VOC. The angle is directly measured by the naked eye on a 3-D protractor printed on a paper facing the cantilevers. The generated angle patterns are subjected to statistical algorithms (linear discriminant analysis (LDA)) to classify each VOC sample and selectively detect a VOC. We classified four VOC samples with 100% accuracy using LDA. Copyright © 2016 Elsevier B.V. All rights reserved.

Iodination of Escherichia coli with chloramine T: selective labeling of the outer membrane lipoprotein.

PubMed Central

Munford, R S; Gotschlich, E C

1977-01-01

Iodination of Escherichia coli cells with chloramine T preferentially labels the free and murein-bound forms of the outer membrane lipoprotein. Iodination for 15 s at 15 degrees C labels the two forms of the lipoprotein almost exclusively, whereas iodination for 60 s at 25 degrees C also labels the other major outer membrane proteins. Chloramine T iodination is a rapid, simple technique for labeling the outer membrane lipoprotein. PMID:400793

Paradigm Shift Additive Manufacturing and the New Way of War

DTIC Science & Technology

2016-12-01

keep costs low: Simple parts are easier to make. Once a product design has been selected and tooling has been obtained, a change in design becomes...adversary’s OODA loop through rapid design and manufacturing . We need to do this; enable this capabil- ity now before our adversaries do, as they might not...35 Defense AT&L: November-December 2016 Paradigm Shift Additive Manufacturing and the New Way of War Brett P. Conner Conner is an associate

Electrochemical hydrogen sulfide biosensors.

PubMed

Xu, Tailin; Scafa, Nikki; Xu, Li-Ping; Zhou, Shufeng; Abdullah Al-Ghanem, Khalid; Mahboob, Shahid; Fugetsu, Bunshi; Zhang, Xueji

2016-02-21

The measurement of sulfide, especially hydrogen sulfide, has held the attention of the analytical community due to its unique physiological and pathophysiological roles in biological systems. Electrochemical detection offers a rapid, highly sensitive, affordable, simple, and real-time technique to measure hydrogen sulfide concentration, which has been a well-documented and reliable method. This review details up-to-date research on the electrochemical detection of hydrogen sulfide (ion selective electrodes, polarographic hydrogen sulfide sensors, etc.) in biological samples for potential therapeutic use.

Highly selective rhodium catalyzed domino C-H activation/cyclizations.

PubMed

Trans, Duc N; Cramer, Nicolai

2011-01-01

The direct functionalization of carbon-hydrogen bonds is an emerging tool to establish more sustainable and efficient synthetic methods. We present its implementation in a cascade reaction that provides a rapid assembly of functionalized indanylamines from simple and readily available starting materials. Careful choice of the ancillary ligand---an electron-rich bidentate phosphine ligand--enables highly diastereoselective rhodium(i)-catalyzed intramolecular allylations of unsubstituted ketimines induced by a directed C-H bond activation and allene carbo-metalation sequence.

Spectrophotometric simultaneous determination of Rabeprazole Sodium and Itopride Hydrochloride in capsule dosage form

NASA Astrophysics Data System (ADS)

Sabnis, Shweta S.; Dhavale, Nilesh D.; Jadhav, Vijay. Y.; Gandhi, Santosh V.

2008-03-01

A new simple, economical, rapid, precise and accurate method for simultaneous determination of rabeprazole sodium and itopride hydrochloride in capsule dosage form has been developed. The method is based on ratio spectra derivative spectrophotometry. The amplitudes in the first derivative of the corresponding ratio spectra at 231 nm (minima) and 260 nm were selected to determine rabeprazole sodium and itopride hydrochloride, respectively. The method was validated with respect to linearity, precision and accuracy.

Spectrophotometric simultaneous determination of rabeprazole sodium and itopride hydrochloride in capsule dosage form.

PubMed

Sabnis, Shweta S; Dhavale, Nilesh D; Jadhav, Vijay Y; Gandhi, Santosh V

2008-03-01

A new simple, economical, rapid, precise and accurate method for simultaneous determination of rabeprazole sodium and itopride hydrochloride in capsule dosage form has been developed. The method is based on ratio spectra derivative spectrophotometry. The amplitudes in the first derivative of the corresponding ratio spectra at 231nm (minima) and 260nm were selected to determine rabeprazole sodium and itopride hydrochloride, respectively. The method was validated with respect to linearity, precision and accuracy.

Simple and rapid silver nanoparticles based antioxidant capacity assays: Reactivity study for phenolic compounds.

PubMed

Della Pelle, Flavio; Scroccarello, Annalisa; Sergi, Manuel; Mascini, Marcello; Del Carlo, Michele; Compagnone, Dario

2018-08-01

A single-step, rapid (10 min), sensitive silver nanoparticles (AgNPs) based spectrophotometric method for antioxidant capacity (AOC) assay has been developed. The assay is based on the ability of natural polyphenols to reduce Ag(I) and stabilize the produced AgNPs(0) at room temperature. Localized surface plasmon resonance (LSPR) of AgNPs at ≈420 nm is then measured. Using different conditions of pH (8.4) and temperature (45 °C) a further assay based on the production of AgNPs with selectivity for flavonols was also developed. The reactivity of the two AgNPs based assays vs. 15 polyphenols belonging to different chemical classes and 9 different samples has been studied and compared with ABTS, Folin and AuNPs based methods for AOC. The proposed assays had good reproducibility (RSD ≤ 13) and are simple, sensitive and cost effective. Moreover, used in conjunction with the classical AOC assays, can improve the information on the polyphenolic pool of food samples. Copyright © 2018 Elsevier Ltd. All rights reserved.

Comparative Validation of the Determination of Sofosbuvir in Pharmaceuticals by Several Inexpensive Ecofriendly Chromatographic, Electrophoretic, and Spectrophotometric Methods.

PubMed

El-Yazbi, Amira F

2017-01-20

Sofosbuvir (SOFO) was approved by the U.S. Food and Drug Administration in 2013 for the treatment of hepatitis C virusinfection with enhanced antiviral potency compared with earlier analogs. Notwithstanding, all current editions of the pharmacopeias still do not present any analytical methods for the quantification of SOFO. Thus, rapid, simple, and ecofriendly methods for the routine analysis of commercial formulations of SOFO are desirable. In this study, five accurate methods for the determination of SOFO in pharmaceutical tablets were developed and validated. These methods include HPLC, capillary zone electrophoresis, HPTLC, and UV spectrophotometric and derivative spectrometry methods. The proposed methods proved to be rapid, simple, sensitive, selective, and accurate analytical procedures that were suitable for the reliable determination of SOFO in pharmaceutical tablets. An analysis of variance test with <em>P</em>-value &#x003E; 0.05 confirmed that there were no significant differences between the proposed assays. Thus, any of these methods can be used for the routine analysis of SOFO in commercial tablets.

Therapeutic Drug Monitoring of Phenytoin by Simple, Rapid, Accurate, Highly Sensitive and Novel Method and Its Clinical Applications.

PubMed

Shaikh, Abdul S; Guo, Ruichen

2017-01-01

Phenytoin has very challenging pharmacokinetic properties. To prevent its toxicity and ensure efficacy, continuous therapeutic monitoring is required. It is hard to get a simple, accurate, rapid, easily available, economical and highly sensitive assay in one method for therapeutic monitoring of phenytoin. The present study is directed towards establishing and validating a simpler, rapid, an accurate, highly sensitive, novel and environment friendly liquid chromatography/mass spectrometry (LC/MS) method for offering rapid and reliable TDM results of phenytoin in epileptic patients to physicians and clinicians for making immediate and rational decision. 27 epileptics patients with uncontrolled seizures or suspected of non-compliance or toxicity of phenytoin were selected and advised for TDM of phenytoin by neurologists of Qilu Hospital Jinan, China. The LC/MS assay was used for performing of therapeutic monitoring of phenytoin. The Agilent 1100 LC/MS system was used for TDM. The mixture of Ammonium acetate 5mM: Methanol at (35: 65 v/v) was used for the composition of mobile phase. The Diamonsil C18 (150mm×4.6mm, 5μm) column was used for the extraction of analytes in plasma. The samples were prepared with one step simple protein precipitation method. The technique was validated with the guidelines of International Conference on Harmonisation (ICH). The calibration curve demonstrated decent linearity within (0.2-20 µg/mL) concentration range with linearity equation, y= 0.0667855 x +0.00241785 and correlation coefficient (R2) of 0.99928. The specificity, recovery, linearity, accuracy, precision and stability results were within the accepted limits. The concentration of 0.2 µg/mL was observed as lower limit of quantitation (LLOQ), which is 12.5 times lower than the currently available enzyme-multiplied immunoassay technique (EMIT) for measurement of phenytoin in epilepsy patients. A rapid, simple, economical, precise, highly sensitive and novel LC/MS assay has been established, validated and applied successfully in TDM of 27 epileptics patients. It was alarmingly found that TDM results of all these patients were out of safe range except two patients. However, it needs further evaluation. Besides TDM, the stated method can also be applied in bioequivalence, pharmacokinetics, toxicokinetics and pharmacovigilance studies. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

A simple and rapid technique for the authentication of the ginseng cultivar, Yunpoong, using an SNP marker in a large sample of ginseng leaves.

PubMed

Sun, Hua; Wang, Hong-Tao; Kwon, Woo-Saeng; Kim, Yeon-Ju; In, Jun-Gyo; Yang, Deok-Chun

2011-11-01

Yunpoong is an important Korean ginseng (Panax ginseng C. A. Meyer) cultivar, but no molecular marker has been available to identify Yunpoong from other cultivars. In this study, we developed a single nucleotide polymorphism (SNP) marker for Yunpoong based on analysis of expressed sequence tags (ESTs) in an exon region of the glyceraldehyde 3-phosphate dehydrogenase (GAPDH) gene. This SNP marker had high specificity to authenticate Yunpoong in twelve different main ginseng cultivars. For application of the molecular marker, a rapid identification method was established based on the NaOH-Tris method and real-time polymerase chain reaction (PCR) in order to ensure more efficiency in the cultivar selection. The biggest feature of the NaOH-Tris method was that it made the extraction of DNA very simple and rapid in young leaf tissues. We only spent 1 min to extract DNA and directly used it to do PCR. In this report, the conventional DNA extraction method was used to develop molecular marker process, and the NaOH-Tris method was applied in screening large numbers of cultivars. Moreover, the greatest advantage of the real-time PCR compared with traditional PCR, is time saving and high efficiency. Thus, this strategy provides a rapid and reliable method for the specific identification of Yunpoong in a large number of samples. Copyright © 2011 Elsevier B.V. All rights reserved.

High-throughput and selective solid-phase extraction of urinary catecholamines by crown ether-modified resin composite fiber.

PubMed

Chen, LiQin; Wang, Hui; Xu, Zhen; Zhang, QiuYue; Liu, Jia; Shen, Jun; Zhang, WanQi

2018-08-03

In the present study, we developed a simple and high-throughput solid phase extraction (SPE) procedure for selective extraction of catecholamines (CAs) in urine samples. The SPE adsorbents were electrospun composite fibers functionalized with 4-carboxybenzo-18-crown-6 ether modified XAD resin and polystyrene, which were packed into 96-well columns and used for high-throughput selective extraction of CAs in healthy human urine samples. Moreover, the extraction efficiency of packed-fiber SPE (PFSPE) was examined by high performance liquid chromatography coupled with fluorescence detector. The parameters affecting the extraction efficiency and impurity removal efficiency were optimized, and good linearity ranging from 0.5 to 400 ng/mL was obtained with a low limit of detection (LOD, 0.2-0.5 ng/mL) and a good repeatability (2.7%-3.7%, n = 6). The extraction recoveries of three CAs ranged from 70.5% to 119.5%. Furthermore, stable and reliable results obtained by the fluorescence detector were superior to those obtained by the electrochemical detector. Collectively, PFSPE coupled with 96-well columns was a simple, rapid, selective, high-throughput and cost-efficient method, and the proposed method could be applied in clinical chemistry. Copyright © 2018 Elsevier B.V. All rights reserved.

Supramolecular analytical chemistry.

PubMed

Anslyn, Eric V

2007-02-02

A large fraction of the field of supramolecular chemistry has focused in previous decades upon the study and use of synthetic receptors as a means of mimicking natural receptors. Recently, the demand for synthetic receptors is rapidly increasing within the analytical sciences. These classes of receptors are finding uses in simple indicator chemistry, cellular imaging, and enantiomeric excess analysis, while also being involved in various truly practical assays of bodily fluids. Moreover, one of the most promising areas for the use of synthetic receptors is in the arena of differential sensing. Although many synthetic receptors have been shown to yield exquisite selectivities, in general, this class of receptor suffers from cross-reactivities. Yet, cross-reactivity is an attribute that is crucial to the success of differential sensing schemes. Therefore, both selective and nonselective synthetic receptors are finding uses in analytical applications. Hence, a field of chemistry that herein is entitled "Supramolecular Analytical Chemistry" is emerging, and is predicted to undergo increasingly rapid growth in the near future.

Potentials for Soil Enzyme as Indicators of Ecological Management

NASA Technical Reports Server (NTRS)

Senwo, Z. N.; Manu, A.; Coleman, T. L.

1997-01-01

Activity measurements of selected soil enzymes (cellulase, glucosidase, amidohydrolase, phosphatase, arylsulfatase) involved in carbon, nitrogen, phosphorus, and sulfur cycling in the biosphere, hold potential as early and sensitive indicators of soil ecological stress and restoration, These measurements are advantageous because the procedures are simple, rapid, and reproducible over time. Enzyme activities are sensitive to short-term changes in soil and kind-use management. Enzyme activities have also been observed to be closely related to soil organic matter proposed as an index of soil quality.

Cryosurgery for treatment of trichiasis.

PubMed Central

Sullivan, J H; Beard, C; Bullock, J D

1976-01-01

We cryosurgically destroyed eyelashes in rabbits and applied the technique to treat 23 selected patients with trichiasis. Liquid nitrogen was sprayed on the eyelid margin by using a double, rapid-freeze, slow-thaw cycle monitored by a subcutaneous thermocouple to -30 degrees C. It was an improvement on electrolysis and a simple alternative to surgery. Images FIGURE 1 FIGURE 2 A FIGURE 2 B FIGURE 3 A FIGURE 3 B FIGURE 4 A FIGURE 4 B FIGURE 5 A FIGURE 5 B FIGURE 7 A FIGURE 7 B PMID:867626

Rapid and Efficient Conversion of (11) CO2 to (11) CO through Silacarboxylic Acids: Applications in Pd-Mediated Carbonylations.

PubMed

Nordeman, Patrik; Friis, Stig D; Andersen, Thomas L; Audrain, Hélène; Larhed, Mats; Skrydstrup, Troels; Antoni, Gunnar

2015-12-01

Herein, we present a new rapid, efficient, and low-cost radiosynthetic protocol for the conversion of (11) CO2 to (11) CO and its subsequent application in Pd-mediated reactions of importance for PET applications. This room-temperature methodology, using readily available chemical reagents, is carried out in simple glass vials, thus eliminating the need for expensive and specialized high-temperature equipment to access (11) CO. With this fast and near-quantitative conversion of (11) CO2 into (11) CO, aryl and heteroaryl iodides were easily converted into a broad selection of biologically active amides in radiochemical yields ranging from 29-84 %. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Optimal low thrust geocentric transfer. [mission analysis computer program

NASA Technical Reports Server (NTRS)

Edelbaum, T. N.; Sackett, L. L.; Malchow, H. L.

1973-01-01

A computer code which will rapidly calculate time-optimal low thrust transfers is being developed as a mission analysis tool. The final program will apply to NEP or SEP missions and will include a variety of environmental effects. The current program assumes constant acceleration. The oblateness effect and shadowing may be included. Detailed state and costate equations are given for the thrust effect, oblateness effect, and shadowing. A simple but adequate model yields analytical formulas for power degradation due to the Van Allen radiation belts for SEP missions. The program avoids the classical singularities by the use of equinoctial orbital elements. Kryloff-Bogoliuboff averaging is used to facilitate rapid calculation. Results for selected cases using the current program are given.

The use of a projection method to simplify portal and hepatic vein segmentation in liver anatomy.

PubMed

Huang, Shaohui; Wang, Boliang; Cheng, Ming; Huang, Xiaoyang; Ju, Ying

2008-12-01

In living donor liver transplantation, the volume of the potential graft must be measured to ensure sufficient liver function after surgery. Couinaud divided the liver into 8 functionally independent segments. However, this method is not simple to perform in 3D space directly. Thus, we propose a rapid method to segment the liver based on the hepatic vessel tree. The most important step of this method is vascular projection. By carefully selecting a projection plane, a 3D point can be fixed in the projection plane. This greatly helps in rapid classification. This method was validated by applying it to a 3D liver depicted on CT images, and the result was in good agreement with Couinaud's classification.

Selection of actuator locations for static shape control of large space structures by heuristic integer programing

NASA Technical Reports Server (NTRS)

Haftka, R. T.; Adelman, H. M.

1984-01-01

Orbiting spacecraft such as large space antennas have to maintain a highly accurate space to operate satisfactorily. Such structures require active and passive controls to mantain an accurate shape under a variety of disturbances. Methods for the optimum placement of control actuators for correcting static deformations are described. In particular, attention is focused on the case were control locations have to be selected from a large set of available sites, so that integer programing methods are called for. The effectiveness of three heuristic techniques for obtaining a near-optimal site selection is compared. In addition, efficient reanalysis techniques for the rapid assessment of control effectiveness are presented. Two examples are used to demonstrate the methods: a simple beam structure and a 55m space-truss-parabolic antenna.

Facile preparation of magnetic molecularly imprinted polymers for the selective extraction and determination of dexamethasone in skincare cosmetics using HPLC.

PubMed

Du, Wei; Zhang, Bilin; Guo, Pengqi; Chen, Guoning; Chang, Chun; Fu, Qiang

2018-03-15

Dexamethasone-imprinted polymers were fabricated by reversible addition-fragmentation chain transfer polymerization on the surface of magnetic nanoparticles under mild polymerization conditions, which exhibited a narrow polydispersity and high selectivity for dexamethasone extraction. The dexamethasone-imprinted polymers were characterized by scanning electron microscopy, transmission electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive spectrometry, and vibrating sample magnetometry. The adsorption performance was evaluated by static adsorption, kinetic adsorption and selectivity tests. The results confirmed the successful construction of an imprinted polymer layer on the surface of the magnetic nanoparticles, which benefits the characteristics of high adsorption capacity, fast mass transfer, specific molecular recognition, and simple magnetic separation. Combined with high-performance liquid chromatography, molecularly imprinted polymers as magnetic extraction sorbents were used for the rapid and selective extraction and determination of dexamethasone in skincare cosmetic samples, with the accuracies of the spiked samples ranging from 93.8 to 97.6%. The relative standard deviations were less than 2.7%. The limit of detection and limit of quantification were 0.05 and 0.20 μg/mL, respectively. The developed method was simple, fast and highly selective and could be a promising method for dexamethasone monitoring in cosmetic products. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gold nanoparticles generated through "green route" bind Hg2+ with a concomitant blue shift in plasmon absorption peak.

PubMed

Radhakumary, C; Sreenivasan, K

2011-07-21

We discuss here a quick, simple, economic and ecofriendly method through a completely green route for the selective detection of Hg(2+) in aqueous samples. Here we exploited the ability of chitosan to generate gold nanoparticles and subsequently to act as a stabilizer for the formed nanoparticles. When chitosan stabilized gold nanoparticles (CH-Au NPs) are interacted with Hg(2+) a blue shift for its localized surface plasmon resonance absorbance (LSPR) band is observed. The blue shift is reasoned to be due to the formation of a thin layer of mercury over gold. A concentration as low as 0.01 ppm to a maximum of 100 ppm Hg(2+) can be detected based on this blue shift of the CH-Au NPs. While all other reported methods demand complex reaction steps and costly chemicals, the method we reported here is a simple, rapid and selective approach for the detection of Hg(2+). Our results also show that the CH-Au NPs have excellent selectivity to Hg(2+) over common cations namely, Pb(2+), Cd(2+), Mn(2+), Fe(2+), Ag(1+), Ce(4+), Ni(2+), and Cu(2+).

Holey graphene frameworks for highly selective post-combustion carbon capture

PubMed Central

Chowdhury, Shamik; Balasubramanian, Rajasekhar

2016-01-01

Atmospheric CO2 concentrations continue to rise rapidly in response to increased combustion of fossil fuels, contributing to global climate change. In order to mitigate the effects of global warming, development of new materials for cost-effective and energy-efficient CO2 capture is critically important. Graphene-based porous materials are an emerging class of solid adsorbents for selectively removing CO2 from flue gases. Herein, we report a simple and scalable approach to produce three-dimensional holey graphene frameworks with tunable porosity and pore geometry, and demonstrate their application as high-performance CO2 adsorbents. These holey graphene macrostructures exhibit a significantly improved specific surface area and pore volume compared to their pristine counterparts, and can be effectively used in post-combustion CO2 adsorption systems because of their intrinsic hydrophobicity together with good gravimetric storage capacities, rapid removal capabilities, superior cycling stabilities, and moderate initial isosteric heats. In addition, an exceptionally high CO2 over N2 selectivity can be achieved under conditions relevant to capture from the dry exhaust gas stream of a coal burning power plant, suggesting the possibility of recovering highly pure CO2 for long-term sequestration and/or utilization for downstream applications. PMID:26879393

Rapid and selective screening of melamine in bovine milk using molecularly imprinted matrix solid-phase dispersion coupled with liquid chromatography-ultraviolet detection.

PubMed

Yan, Hongyuan; Cheng, Xiaoling; Sun, Ning; Cai, Tianyu; Wu, Ruijun; Han, Kun

2012-11-01

A simple, convenient and high selective molecularly imprinted matrix solid-phase dispersion (MI-MSPD) using water-compatible cyromazine-imprinted polymer as adsorbent was proposed for the rapid screening of melamine from bovine milk coupled with liquid chromatography-ultraviolet detection. The molecularly imprinted polymers (MIPs) synthesized by cyromazine as dummy template and reformative methanol-water system as reaction medium showed higher affinity and selectivity to melamine, and so they were applied as the specific dispersant of MSPD to extraction of melamine and simultaneously eliminate the effect of template leakage on quantitative analysis. Under the optimized conditions, good linearity was obtained in a range of 0.24-60.0μgg(-1) with the correlation coefficient of 0.9994. The recoveries of melamine at three spiked levels were ranged from 86.0 to 96.2% with the relative standard deviation (RSD)≤4.0%. This proposed MI-MSPD method combined the advantages of MSPD and MIPs, and could be used as an alternative tool for analyzing the residues of melamine in complex milk samples. Copyright © 2012 Elsevier B.V. All rights reserved.

Holey graphene frameworks for highly selective post-combustion carbon capture.

PubMed

Chowdhury, Shamik; Balasubramanian, Rajasekhar

2016-02-16

Atmospheric CO2 concentrations continue to rise rapidly in response to increased combustion of fossil fuels, contributing to global climate change. In order to mitigate the effects of global warming, development of new materials for cost-effective and energy-efficient CO2 capture is critically important. Graphene-based porous materials are an emerging class of solid adsorbents for selectively removing CO2 from flue gases. Herein, we report a simple and scalable approach to produce three-dimensional holey graphene frameworks with tunable porosity and pore geometry, and demonstrate their application as high-performance CO2 adsorbents. These holey graphene macrostructures exhibit a significantly improved specific surface area and pore volume compared to their pristine counterparts, and can be effectively used in post-combustion CO2 adsorption systems because of their intrinsic hydrophobicity together with good gravimetric storage capacities, rapid removal capabilities, superior cycling stabilities, and moderate initial isosteric heats. In addition, an exceptionally high CO2 over N2 selectivity can be achieved under conditions relevant to capture from the dry exhaust gas stream of a coal burning power plant, suggesting the possibility of recovering highly pure CO2 for long-term sequestration and/or utilization for downstream applications.

A selectively rhodamine-based colorimetric probe for detecting copper(II) ion.

PubMed

Zhang, Jiangang; Zhang, Li; Wei, Yanli; Chao, Jianbing; Shuang, Shaomin; Cai, Zongwei; Dong, Chuan

2014-11-11

A novel rhodamine derivative 3-bromo-5-methylsalicylaldehyde rhodamine B hydrazone (BMSRH) has been synthesized by reacting rhodamine B hydrazide with 3-bromo-5-methylsalicylaldehyde and developed as a new colorimetric probe for the selective and sensitive detection of Cu2+. Addition of Cu2+ to the solution of BMSRH results in a rapid color change from colorless to red together with an obvious new band appeared at 552 nm in the UV-vis absorption spectra. This change is attributed to the spirocycle form of BMSRH opened via coordination with Cu2+ in a 1:1 stoichiometry and their association constant is determined as 3.2×10(4) L mol(-1). Experimental results indicate that the BMSRH can provide a rapid, selective and sensitive response to Cu2+ with a linear dynamic range 0.667-240 μmol/L. Common interferent ions do not show any interference on the Cu2+ determination. It is anticipated that BMSRH can be a good candidate probe and has potential application for Cu2+ determination. The proposed probe exhibits the following advantages: a quick, simple and facile synthesis. Copyright © 2014 Elsevier B.V. All rights reserved.

Holey graphene frameworks for highly selective post-combustion carbon capture

NASA Astrophysics Data System (ADS)

Chowdhury, Shamik; Balasubramanian, Rajasekhar

2016-02-01

Atmospheric CO2 concentrations continue to rise rapidly in response to increased combustion of fossil fuels, contributing to global climate change. In order to mitigate the effects of global warming, development of new materials for cost-effective and energy-efficient CO2 capture is critically important. Graphene-based porous materials are an emerging class of solid adsorbents for selectively removing CO2 from flue gases. Herein, we report a simple and scalable approach to produce three-dimensional holey graphene frameworks with tunable porosity and pore geometry, and demonstrate their application as high-performance CO2 adsorbents. These holey graphene macrostructures exhibit a significantly improved specific surface area and pore volume compared to their pristine counterparts, and can be effectively used in post-combustion CO2 adsorption systems because of their intrinsic hydrophobicity together with good gravimetric storage capacities, rapid removal capabilities, superior cycling stabilities, and moderate initial isosteric heats. In addition, an exceptionally high CO2 over N2 selectivity can be achieved under conditions relevant to capture from the dry exhaust gas stream of a coal burning power plant, suggesting the possibility of recovering highly pure CO2 for long-term sequestration and/or utilization for downstream applications.

Development of molecularly imprinted column-on line-two dimensional liquid chromatography for rapidly and selectively monitoring estradiol in cosmetics.

PubMed

Guo, Pengqi; Xu, Xinya; Xian, Liang; Ge, Yanhui; Luo, Zhimin; Du, Wei; Jing, Wanghui; Zeng, Aiguo; Chang, Chun; Fu, Qiang

2016-12-01

Nowadays, the illegal use of estradiol in cosmetics has caused a series of events which endangering public health seriously. Therefore, it is imperative to establish a simple, fast and specific method for monitoring the illegal use of estradiol in cosmetics. In current study, we developed a molecular imprinted monolithic column two dimensional liquid chromatography method (MIMC-2D-LC) for rapid and selective determination of estradiol in various cosmetic samples. The best polymerization, morphology, structure property, surface groups, and the adsorption performance of the prepared material were investigated. The MIMC-2D-LC was validated and successfully used for detecting estradiol in cosmetic samples with good selectivity, sensitivity, efficiency and reproducibility. The linear range of the MIMC-2D-LC for estradiol was 0.5-50μgg -1 with the limit of detection of 0.08μgg -1 . Finally, six batches of cosmetic samples obtained from local markets were tested by the proposed method. The test results showed that the illegal use of estradiol still existed in the commercially available samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Determination of hydrazine in drinking water: Development and multivariate optimization of a rapid and simple solid phase microextraction-gas chromatography-triple quadrupole mass spectrometry protocol.

PubMed

Gionfriddo, Emanuela; Naccarato, Attilio; Sindona, Giovanni; Tagarelli, Antonio

2014-07-04

In this work, the capabilities of solid phase microextraction were exploited in a fully optimized SPME-GC-QqQ-MS analytical approach for hydrazine assay. A rapid and easy method was obtained by a simple derivatization reaction with propyl chloroformate and pyridine carried out directly in water samples, followed by automated SPME analysis in the same vial without further sample handling. The affinity of the different derivatized compounds obtained towards five commercially available SPME coatings was evaluated, in order to achieve the best extraction efficiency. GC analyses were carried out using a GC-QqQ-MS instrument in selected reaction monitoring (SRM) acquisition mode which has allowed the achievement of high specificity by selecting appropriate precursor-product ion couples improving the capability in analyte identification. The multivariate approach of experimental design was crucial in order to optimize derivatization reaction, SPME process and tandem mass spectrometry parameters. Accuracy of the proposed protocol, tested at 60, 200 and 800 ng L(-1), provided satisfactory values (114.2%, 83.6% and 98.6%, respectively), whereas precision (RSD%) at the same concentration levels were of 10.9%, 7.9% and 7.7% respectively. Limit of detection and quantification of 4.4 and 8.3 ng L(-1) were obtained. The reliable application of the proposed protocol to real drinking water samples confirmed its capability to be used as analytical tool for routine analyses. Copyright © 2014 Elsevier B.V. All rights reserved.

Improved HPLC method for determination of four PPIs, omeprazole, pantoprazole, lansoprazole and rabeprazole in human plasma.

PubMed

Noubarani, Maryam; Keyhanfar, Fariborz; Motevalian, Manijeh; Mahmoudian, Masoud

2010-01-01

To develop a simple and rapid HPLC method for measuring of four proton-pump inhibitors (PPIs), omeprazole (OPZ), pantoprazole (PPZ), lansoprazole (LPZ) and rabeprazole (RPZ) concentrations in human plasma. Following a single step liquid-liquid extraction analytes along with an internal standard (IS) were separated using an isocratic mobile phase of phosphate buffer (10 mM)/acetonitrile (53/47, v/v adjusted pH to 7.3 with triethylamine) at flow rate of 1 mL/min on reverse phase TRACER EXCEL 120 ODS-A column at room temperature. Total analytical run time for selected PPIs was 10 min. The assays exhibited good linearity (r(2)>0.99) over the studied range of 20 to 2500 ng/mL for OPZ, 20 to 4000 ng/mL for PPZ, 20 to 3000 ng/mL for LPZ and 20 to 1500 ng/mL for RPZ. The recovery of method was equal or greater than 80% and lower limit of quantification (LLOQ) was 20 ng/mL for four PPIs. Coefficient of variation and error at all of the intra-day and inter-day assessment were less than 9.2% for all compounds. The results indicated that this method is a simple, rapid, precise and accurate assay for determination of four PPIs concentrations in human plasma. This validated method is sensitive and reproducible enough to be used in pharmacokinetic studies and also is time- and cost-benefit when selected PPIs are desired to be analyzed.

Simple and rapid LC-MS/MS method for the absolute determination of cetuximab in human serum using an immobilized trypsin.

PubMed

Shibata, Kaito; Naito, Takafumi; Okamura, Jun; Hosokawa, Seiji; Mineta, Hiroyuki; Kawakami, Junichi

2017-11-30

Proteomic approaches using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) without an immunopurification technique have not been applied to the determination of serum cetuximab. This study developed a simple and rapid LC-MS/MS method for the absolute determination of cetuximab in human serum and applied it to clinical settings. Surrogate peptides derived from cetuximab digests were selected using a Fourier transform mass spectrometer. Reduced-alkylated serum cetuximab without immunopurification was digested for 20minutes using immobilized trypsin, and the digestion products were purified by solid-phase extraction. The LC-MS/MS was run in positive ion multiple reaction monitoring mode. This method was applied to the determination of serum samples in head and neck cancer patients treated with cetuximab. The chromatographic run time was 10minutes and no peaks interfering with surrogate peptides in serum digestion products were observed. The calibration curve of absolute cetuximab in serum was linear over the concentration range of 4-200μg/mL. The lower limit of quantification of cetuximab in human serum was 4μg/mL. The intra-assay and inter-assay precision and accuracy were less than 13.2% and 88.0-100.7%, respectively. The serum concentration range of cetuximab was 19-140μg/mL in patients. The serum cetuximab concentrations in LC-MS/MS were correlated with those in ELISA (r=0.899, P <0.01) and the mean bias was 1.5% in cancer patients. In conclusion, the present simple and rapid method with acceptable analytical performance can be helpful for evaluating the absolute concentration of serum cetuximab in clinical settings. Copyright © 2017 Elsevier B.V. All rights reserved.

Toluidine blue: rapid and simple malaria parasite screening and species identification.

PubMed

Awale, Rupali; Maji, Ratnaprabha; Patil, Parag; Lingiah, Raghavendra; Mukhopadhyay, Ashok Kumar; Sharma, Subhadra

2017-01-01

Malaria, a febrile illness mostly confined to the tropical countries is transmitted by bite of infected female Anopheles mosquito. In 2015 alone, 88% of the malaria burden and 90% deaths due to malaria were confined to the African and Asian countries. Although number of tests are available for rapid diagnosis and screening for malaria, peripheral blood smear examination remains the gold standard. Leishman stain is recommended by WHO however herein we evaluate one of the alternative methods of staining which is simple and rapid. Fifty patients attending the various outpatient departments of the tertiary care hospital with fever and suspected to have malaria were selected. Two thin-air dried smears prepared from the peripheral venous blood from these subjects were stained by Leishman and Toluidine blue method. The findings of the slides by two independent qualified professionals were noted and the results were analyzed. A total of 14% (7/50) cases were diagnosed to have malaria. All the malaria cases which were positive in Leishman stain were also detected in Toluidine blue stain. Malarial parasites were clearly visible against the homogenously light green background in Toluidine blue. The detection of malarial parasite by Toluidine blue was quick, easy and confirmative. Toluidine blue stained peripheral blood smear allows for easy identification and speciation of malarial parasite at low magnification and in shorter period of time.

A 48 SNP set for grapevine cultivar identification

PubMed Central

2011-01-01

Background Rapid and consistent genotyping is an important requirement for cultivar identification in many crop species. Among them grapevine cultivars have been the subject of multiple studies given the large number of synonyms and homonyms generated during many centuries of vegetative multiplication and exchange. Simple sequence repeat (SSR) markers have been preferred until now because of their high level of polymorphism, their codominant nature and their high profile repeatability. However, the rapid application of partial or complete genome sequencing approaches is identifying thousands of single nucleotide polymorphisms (SNP) that can be very useful for such purposes. Although SNP markers are bi-allelic, and therefore not as polymorphic as microsatellites, the high number of loci that can be multiplexed and the possibilities of automation as well as their highly repeatable results under any analytical procedure make them the future markers of choice for any type of genetic identification. Results We analyzed over 300 SNP in the genome of grapevine using a re-sequencing strategy in a selection of 11 genotypes. Among the identified polymorphisms, we selected 48 SNP spread across all grapevine chromosomes with allele frequencies balanced enough as to provide sufficient information content for genetic identification in grapevine allowing for good genotyping success rate. Marker stability was tested in repeated analyses of a selected group of cultivars obtained worldwide to demonstrate their usefulness in genetic identification. Conclusions We have selected a set of 48 stable SNP markers with a high discrimination power and a uniform genome distribution (2-3 markers/chromosome), which is proposed as a standard set for grapevine (Vitis vinifera L.) genotyping. Any previous problems derived from microsatellite allele confusion between labs or the need to run reference cultivars to identify allele sizes disappear using this type of marker. Furthermore, because SNP markers are bi-allelic, allele identification and genotype naming are extremely simple and genotypes obtained with different equipments and by different laboratories are always fully comparable. PMID:22060012

Simple new test for rapid differentiation of Prototheca wickerhamii from Prototheca zopfii.

PubMed Central

Casal, M J; Gutierrez, J

1983-01-01

A simple new test to differentiate Prototheca wickerhamii from Prototheca zopfii by determining susceptibility to clotrimazole is described. A 50-micrograms clotrimazole disk provides a rapid and reliable means of distinguishing P. wickerhamii from P. zopfii. PMID:6630477

Selective Activation of N,N'-Diacyl Rhodamine Pro-fluorophores Paired with Releasing Enzyme, Porcine Liver Esterase (PLE).

PubMed

Abney, Kristopher K; Ramos-Hunter, Susan J; Romaine, Ian M; Godwin, J Shawn; Sulikowski, Gary A; Weaver, Charles David

2018-04-21

This study reports the synthesis and testing of a family of rhodamine pro-fluorophores and an enzyme capable of converting pro-fluorophores to Rhodamine 110. We prepared a library of simple N,N'-diacyl rhodamines and investigated Porcine Liver Esterase (PLE) as an enzyme to activate rhodamine-based pro-fluorophores. A PLE-expressing cell line generated an increase in fluorescence rapidly upon pro-fluorophore addition demonstrating the rhodamine pro-fluorophores are readily taken up and fluorescent upon PLE-mediated release. Rhodamine pro-fluorophore amides trifluoroacetamide (TFAm) and proponamide (PAm) appeared to be the best substrates using a cell-based assay using PLE expressing HEK293. Our pro-fluorophore series showed diffusion into live cells and resisted endogenous hydrolysis. The use of our engineered cell line containing the exogenous enzyme PLE demonstrated the rigorousness of amide masking when compared to cells not containing PLE. This simple and selective pro-fluorophore rhodamine pair with PLE offers the potential to be used in vitro and in vivo fluorescence based assays. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Graphene Quantum Dots-based Photoluminescent Sensor: A Multifunctional Composite for Pesticide Detection.

PubMed

Zor, Erhan; Morales-Narváez, Eden; Zamora-Gálvez, Alejandro; Bingol, Haluk; Ersoz, Mustafa; Merkoçi, Arben

2015-09-16

Due to their size and difficulty to obtain, cost/effective biological or synthetic receptors (e.g., antibodies or aptamers, respectively), organic toxic compounds (e.g., less than 1 kDa) are generally challenging to detect using simple platforms such as biosensors. This study reports on the synthesis and characterization of a novel multifunctional composite material, magnetic silica beads/graphene quantum dots/molecularly imprinted polypyrrole (mSGP). mSGP is engineered to specifically and effectively capture and signal small molecules due to the synergy among chemical, magnetic, and optical properties combined with molecular imprinting of tributyltin (291 Da), a hazardous compound, selected as a model analyte. Magnetic and selective properties of the mSGP composite can be exploited to capture and preconcentrate the analyte onto its surface, and its photoluminescent graphene quantum dots, which are quenched upon analyte recognition, are used to interrogate the presence of the contaminant. This multifunctional material enables a rapid, simple and sensitive platform for small molecule detection, even in complex mediums such as seawater, without any sample treatment.

In vitro Fab display: a cell-free system for IgG discovery

PubMed Central

Stafford, Ryan L.; Matsumoto, Marissa L.; Yin, Gang; Cai, Qi; Fung, Juan Jose; Stephenson, Heather; Gill, Avinash; You, Monica; Lin, Shwu-Hwa; Wang, Willie D.; Masikat, Mary Rose; Li, Xiaofan; Penta, Kalyani; Steiner, Alex R.; Baliga, Ramesh; Murray, Christopher J.; Thanos, Christopher D.; Hallam, Trevor J.; Sato, Aaron K.

2014-01-01

Selection technologies such as ribosome display enable the rapid discovery of novel antibody fragments entirely in vitro. It has been assumed that the open nature of the cell-free reactions used in these technologies limits selections to single-chain protein fragments. We present a simple approach for the selection of multi-chain proteins, such as antibody Fab fragments, using ribosome display. Specifically, we show that a two-chain trastuzumab (Herceptin) Fab domain can be displayed in a format which tethers either the heavy or light chain to the ribosome while retaining functional antigen binding. Then, we constructed synthetic Fab HC and LC libraries and performed test selections against carcinoembryonic antigen (CEA) and vascular endothelial growth factor (VEGF). The Fab selection output was reformatted into full-length immunoglobulin Gs (IgGs) and directly expressed at high levels in an optimized cell-free system for immediate screening, purification and characterization. Several novel IgGs were identified using this cell-free platform that bind to purified CEA, CEA positive cells and VEGF. PMID:24586053

Centrality and rapidity dependence of inclusive jet production in √{sNN} = 5.02 TeV proton-lead collisions with the ATLAS detector

NASA Astrophysics Data System (ADS)

Aad, G.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abreu, R.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Adelman, J.; Adomeit, S.; Adye, T.; Agatonovic-Jovin, T.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahmadov, F.; Aielli, G.; Akerstedt, H.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alberghi, G. L.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Alimonti, G.; Alio, L.; Alison, J.; Allbrooke, B. M. M.; Allison, L. J.; Allport, P. P.; Almond, J.; Aloisio, A.; Alonso, A.; Alonso, F.; Alpigiani, C.; Altheimer, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Amidei, D.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; Amundsen, G.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angelidakis, S.; Angelozzi, I.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Araque, J. P.; Arce, A. T. H.; Arguin, J.-F.; Argyropoulos, S.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Arnold, H.; Arratia, M.; Arslan, O.; Artamonov, A.; Artoni, G.; Asai, S.; Asbah, N.; Ashkenazi, A.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Atkinson, M.; Atlay, N. B.; Auerbach, B.; Augsten, K.; Aurousseau, M.; Avolio, G.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Baas, A. E.; Bacci, C.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Backus Mayes, J.; Badescu, E.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bain, T.; Baines, J. T.; Baker, O. K.; Balek, P.; Balli, F.; Banas, E.; Banerjee, Sw.; Bannoura, A. A. E.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barberio, E. L.; Barberis, D.; Barbero, M.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Barnovska, Z.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartos, P.; Bartsch, V.; Bassalat, A.; Basye, A.; Bates, R. L.; Batley, J. R.; Battaglia, M.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beattie, M. D.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, S.; Beckingham, M.; Becot, C.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Behr, K.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Beringer, J.; Bernard, C.; Bernat, P.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Berta, P.; Bertella, C.; Bertoli, G.; Bertolucci, F.; Bertsche, C.; Bertsche, D.; Besana, M. I.; Besjes, G. J.; Bessidskaia Bylund, O.; Bessner, M.; Besson, N.; Betancourt, C.; Bethke, S.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Bierwagen, K.; Biesiada, J.; Biglietti, M.; Bilbao De Mendizabal, J.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J.-B.; Blazek, T.; Bloch, I.; Blocker, C.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Bock, C.; Boddy, C. R.; Boehler, M.; Boek, T. T.; Bogaerts, J. A.; Bogdanchikov, A. G.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Boldyrev, A. S.; Bomben, M.; Bona, M.; Boonekamp, M.; Borisov, A.; Borissov, G.; Borri, M.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Boudreau, J.; Bouffard, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutouil, S.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bracinik, J.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brelier, B.; Brendlinger, K.; Brennan, A. J.; Brenner, R.; Bressler, S.; Bristow, K.; Bristow, T. M.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Bromberg, C.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brosamer, J.; Brost, E.; Brown, J.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.; Bryngemark, L.; Buanes, T.; Buat, Q.; Bucci, F.; Buchholz, P.; Buckingham, R. M.; Buckley, A. G.; Buda, S. I.; Budagov, I. A.; Buehrer, F.; Bugge, L.; Bugge, M. K.; Bulekov, O.; Bundock, A. C.; Burckhart, H.; Burdin, S.; Burghgrave, B.; Burke, S.; Burmeister, I.; Busato, E.; Büscher, D.; Büscher, V.; Bussey, P.; Buszello, C. P.; Butler, B.; Butler, J. M.; Butt, A. I.; Buttar, C. M.; Butterworth, J. M.; Butti, P.; Buttinger, W.; Buzatu, A.; Byszewski, M.; Cabrera Urbán, S.; Caforio, D.; Cakir, O.; Calafiura, P.; Calandri, A.; Calderini, G.; Calfayan, P.; Calkins, R.; Caloba, L. P.; Calvet, D.; Calvet, S.; Camacho Toro, R.; Camarda, S.; Cameron, D.; Caminada, L. M.; Caminal Armadans, R.; Campana, S.; Campanelli, M.; Campoverde, A.; Canale, V.; Canepa, A.; Cano Bret, M.; Cantero, J.; Cantrill, R.; Cao, T.; Capeans Garrido, M. D. M.; Caprini, I.; Caprini, M.; Capua, M.; Caputo, R.; Cardarelli, R.; Carli, T.; Carlino, G.; Carminati, L.; Caron, S.; Carquin, E.; Carrillo-Montoya, G. D.; Carter, J. R.; Carvalho, J.; Casadei, D.; Casado, M. P.; Casolino, M.; Castaneda-Miranda, E.; Castelli, A.; Castillo Gimenez, V.; Castro, N. F.; Catastini, P.; Catinaccio, A.; Catmore, J. R.; Cattai, A.; Cattani, G.; Caudron, J.; Caughron, S.; Cavaliere, V.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Ceradini, F.; Cerio, B. C.; Cerny, K.; Cerqueira, A. S.; Cerri, A.; Cerrito, L.; Cerutti, F.; Cerv, M.; Cervelli, A.; Cetin, S. A.; Chafaq, A.; Chakraborty, D.; Chalupkova, I.; Chang, P.; Chapleau, B.; Chapman, J. D.; Charfeddine, D.; Charlton, D. G.; Chau, C. C.; Chavez Barajas, C. A.; Cheatham, S.; Chegwidden, A.; Chekanov, S.; Chekulaev, S. V.; Chelkov, G. A.; Chelstowska, M. A.; Chen, C.; Chen, H.; Chen, K.; Chen, L.; Chen, S.; Chen, X.; Chen, Y.; Chen, Y.; Cheng, H. C.; Cheng, Y.; Cheplakov, A.; Cherkaoui El Moursli, R.; Chernyatin, V.; Cheu, E.; Chevalier, L.; Chiarella, V.; Chiefari, G.; Childers, J. T.; Chilingarov, A.; Chiodini, G.; Chisholm, A. S.; Chislett, R. T.; Chitan, A.; Chizhov, M. V.; Chouridou, S.; Chow, B. K. B.; Chromek-Burckhart, D.; Chu, M. L.; Chudoba, J.; Chwastowski, J. J.; Chytka, L.; Ciapetti, G.; Ciftci, A. K.; Ciftci, R.; Cinca, D.; Cindro, V.; Ciocio, A.; Cirkovic, P.; Citron, Z. H.; Citterio, M.; Ciubancan, M.; Clark, A.; Clark, P. J.; Clarke, R. N.; Cleland, W.; Clemens, J. C.; Clement, C.; Coadou, Y.; Cobal, M.; Coccaro, A.; Cochran, J.; Coffey, L.; Cogan, J. G.; Coggeshall, J.; Cole, B.; Cole, S.; Colijn, A. P.; Collot, J.; Colombo, T.; Colon, G.; Compostella, G.; Conde Muiño, P.; Coniavitis, E.; Conidi, M. C.; Connell, S. H.; Connelly, I. A.; Consonni, S. M.; Consorti, V.; Constantinescu, S.; Conta, C.; Conti, G.; Conventi, F.; Cooke, M.; Cooper, B. D.; Cooper-Sarkar, A. M.; Cooper-Smith, N. J.; Copic, K.; Cornelissen, T.; Corradi, M.; Corriveau, F.; Corso-Radu, A.; Cortes-Gonzalez, A.; Cortiana, G.; Costa, G.; Costa, M. J.; Costanzo, D.; Côté, D.; Cottin, G.; Cowan, G.; Cox, B. E.; Cranmer, K.; Cree, G.; Crépé-Renaudin, S.; Crescioli, F.; Cribbs, W. 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L.; Massa, I.; Massa, L.; Massol, N.; Mastrandrea, P.; Mastroberardino, A.; Masubuchi, T.; Mättig, P.; Mattmann, J.; Maurer, J.; Maxfield, S. J.; Maximov, D. A.; Mazini, R.; Mazzaferro, L.; Mc Goldrick, G.; Mc Kee, S. P.; McCarn, A.; McCarthy, R. L.; McCarthy, T. G.; McCubbin, N. A.; McFarlane, K. W.; Mcfayden, J. A.; Mchedlidze, G.; McMahon, S. J.; McPherson, R. A.; Meade, A.; Mechnich, J.; Medinnis, M.; Meehan, S.; Mehlhase, S.; Mehta, A.; Meier, K.; Meineck, C.; Meirose, B.; Melachrinos, C.; Mellado Garcia, B. R.; Meloni, F.; Mengarelli, A.; Menke, S.; Meoni, E.; Mercurio, K. M.; Mergelmeyer, S.; Meric, N.; Mermod, P.; Merola, L.; Meroni, C.; Merritt, F. S.; Merritt, H.; Messina, A.; Metcalfe, J.; Mete, A. S.; Meyer, C.; Meyer, C.; Meyer, J.-P.; Meyer, J.; Middleton, R. P.; Migas, S.; Mijović, L.; Mikenberg, G.; Mikestikova, M.; Mikuž, M.; Milic, A.; Miller, D. W.; Mills, C.; Milov, A.; Milstead, D. A.; Milstein, D.; Minaenko, A. A.; Minashvili, I. A.; Mincer, A. I.; Mindur, B.; Mineev, M.; Ming, Y.; Mir, L. M.; Mirabelli, G.; Mitani, T.; Mitrevski, J.; Mitsou, V. A.; Mitsui, S.; Miucci, A.; Miyagawa, P. S.; Mjörnmark, J. U.; Moa, T.; Mochizuki, K.; Mohapatra, S.; Mohr, W.; Molander, S.; Moles-Valls, R.; Mönig, K.; Monini, C.; Monk, J.; Monnier, E.; Montejo Berlingen, J.; Monticelli, F.; Monzani, S.; Moore, R. W.; Moraes, A.; Morange, N.; Moreno, D.; Moreno Llácer, M.; Morettini, P.; Morgenstern, M.; Morii, M.; Moritz, S.; Morley, A. K.; Mornacchi, G.; Morris, J. D.; Morvaj, L.; Moser, H. G.; Mosidze, M.; Moss, J.; Motohashi, K.; Mount, R.; Mountricha, E.; Mouraviev, S. V.; Moyse, E. J. W.; Muanza, S.; Mudd, R. D.; Mueller, F.; Mueller, J.; Mueller, K.; Mueller, T.; Mueller, T.; Muenstermann, D.; Munwes, Y.; Murillo Quijada, J. A.; Murray, W. J.; Musheghyan, H.; Musto, E.; Myagkov, A. G.; Myska, M.; Nackenhorst, O.; Nadal, J.; Nagai, K.; Nagai, R.; Nagai, Y.; Nagano, K.; Nagarkar, A.; Nagasaka, Y.; Nagel, M.; Nairz, A. M.; Nakahama, Y.; Nakamura, K.; Nakamura, T.; Nakano, I.; Namasivayam, H.; Nanava, G.; Narayan, R.; Nattermann, T.; Naumann, T.; Navarro, G.; Nayyar, R.; Neal, H. A.; Nechaeva, P. Yu.; Neep, T. J.; Nef, P. D.; Negri, A.; Negri, G.; Negrini, M.; Nektarijevic, S.; Nelson, A.; Nelson, T. K.; Nemecek, S.; Nemethy, P.; Nepomuceno, A. A.; Nessi, M.; Neubauer, M. S.; Neumann, M.; Neves, R. M.; Nevski, P.; Newman, P. R.; Nguyen, D. H.; Nickerson, R. B.; Nicolaidou, R.; Nicquevert, B.; Nielsen, J.; Nikiforou, N.; Nikiforov, A.; Nikolaenko, V.; Nikolic-Audit, I.; Nikolics, K.; Nikolopoulos, K.; Nilsson, P.; Ninomiya, Y.; Nisati, A.; Nisius, R.; Nobe, T.; Nodulman, L.; Nomachi, M.; Nomidis, I.; Norberg, S.; Nordberg, M.; Novgorodova, O.; Nowak, S.; Nozaki, M.; Nozka, L.; Ntekas, K.; Nunes Hanninger, G.; Nunnemann, T.; Nurse, E.; Nuti, F.; O'Brien, B. J.; O'grady, F.; O'Neil, D. C.; O'Shea, V.; Oakham, F. G.; Oberlack, H.; Obermann, T.; Ocariz, J.; Ochi, A.; Ochoa, I.; Oda, S.; Odaka, S.; Ogren, H.; Oh, A.; Oh, S. H.; Ohm, C. C.; Ohman, H.; Okamura, W.; Okawa, H.; Okumura, Y.; Okuyama, T.; Olariu, A.; Olchevski, A. G.; Olivares Pino, S. A.; Oliveira Damazio, D.; Oliver Garcia, E.; Olszewski, A.; Olszowska, J.; Onofre, A.; Onyisi, P. U. E.; Oram, C. J.; Oreglia, M. J.; Oren, Y.; Orestano, D.; Orlando, N.; Oropeza Barrera, C.; Orr, R. S.; Osculati, B.; Ospanov, R.; Otero y Garzon, G.; Otono, H.; Ouchrif, M.; Ouellette, E. A.; Ould-Saada, F.; Ouraou, A.; Oussoren, K. P.; Ouyang, Q.; Ovcharova, A.; Owen, M.; Ozcan, V. E.; Ozturk, N.; Pachal, K.; Pacheco Pages, A.; Padilla Aranda, C.; Pagáčová, M.; Pagan Griso, S.; Paganis, E.; Pahl, C.; Paige, F.; Pais, P.; Pajchel, K.; Palacino, G.; Palestini, S.; Palka, M.; Pallin, D.; Palma, A.; Palmer, J. D.; Pan, Y. B.; Panagiotopoulou, E.; Panduro Vazquez, J. G.; Pani, P.; Panikashvili, N.; Panitkin, S.; Pantea, D.; Paolozzi, L.; Papadopoulou, Th. D.; Papageorgiou, K.; Paramonov, A.; Paredes Hernandez, D.; Parker, M. A.; Parodi, F.; Parsons, J. A.; Parzefall, U.; Pasqualucci, E.; Passaggio, S.; Passeri, A.; Pastore, F.; Pastore, Fr.; Pásztor, G.; Pataraia, S.; Patel, N. D.; Pater, J. R.; Patricelli, S.; Pauly, T.; Pearce, J.; Pedersen, M.; Pedraza Lopez, S.; Pedro, R.; Peleganchuk, S. V.; Pelikan, D.; Peng, H.; Penning, B.; Penwell, J.; Perepelitsa, D. V.; Perez Codina, E.; Pérez García-Estañ, M. T.; Perez Reale, V.; Perini, L.; Pernegger, H.; Perrino, R.; Peschke, R.; Peshekhonov, V. D.; Peters, K.; Peters, R. F. Y.; Petersen, B. A.; Petersen, T. C.; Petit, E.; Petridis, A.; Petridou, C.; Petrolo, E.; Petrucci, F.; Pettersson, N. E.; Pezoa, R.; Phillips, P. W.; Piacquadio, G.; Pianori, E.; Picazio, A.; Piccaro, E.; Piccinini, M.; Piegaia, R.; Pignotti, D. T.; Pilcher, J. E.; Pilkington, A. D.; Pina, J.; Pinamonti, M.; Pinder, A.; Pinfold, J. L.; Pingel, A.; Pinto, B.; Pires, S.; Pitt, M.; Pizio, C.; Plazak, L.; Pleier, M.-A.; Pleskot, V.; Plotnikova, E.; Plucinski, P.; Poddar, S.; Podlyski, F.; Poettgen, R.; Poggioli, L.; Pohl, D.; Pohl, M.; Polesello, G.; Policicchio, A.; Polifka, R.; Polini, A.; Pollard, C. S.; Polychronakos, V.; Pommès, K.; Pontecorvo, L.; Pope, B. G.; Popeneciu, G. A.; Popovic, D. S.; Poppleton, A.; Portell Bueso, X.; Pospisil, S.; Potamianos, K.; Potrap, I. N.; Potter, C. J.; Potter, C. T.; Poulard, G.; Poveda, J.; Pozdnyakov, V.; Pralavorio, P.; Pranko, A.; Prasad, S.; Pravahan, R.; Prell, S.; Price, D.; Price, J.; Price, L. E.; Prieur, D.; Primavera, M.; Proissl, M.; Prokofiev, K.; Prokoshin, F.; Protopapadaki, E.; Protopopescu, S.; Proudfoot, J.; Przybycien, M.; Przysiezniak, H.; Ptacek, E.; Puddu, D.; Pueschel, E.; Puldon, D.; Purohit, M.; Puzo, P.; Qian, J.; Qin, G.; Qin, Y.; Quadt, A.; Quarrie, D. R.; Quayle, W. B.; Queitsch-Maitland, M.; Quilty, D.; Qureshi, A.; Radeka, V.; Radescu, V.; Radhakrishnan, S. K.; Radloff, P.; Rados, P.; Ragusa, F.; Rahal, G.; Rajagopalan, S.; Rammensee, M.; Randle-Conde, A. S.; Rangel-Smith, C.; Rao, K.; Rauscher, F.; Rave, T. C.; Ravenscroft, T.; Raymond, M.; Read, A. L.; Readioff, N. P.; Rebuzzi, D. M.; Redelbach, A.; Redlinger, G.; Reece, R.; Reeves, K.; Rehnisch, L.; Reisin, H.; Relich, M.; Rembser, C.; Ren, H.; Ren, Z. L.; Renaud, A.; Rescigno, M.; Resconi, S.; Rezanova, O. L.; Reznicek, P.; Rezvani, R.; Richter, R.; Ridel, M.; Rieck, P.; Rieger, J.; Rijssenbeek, M.; Rimoldi, A.; Rinaldi, L.; Ritsch, E.; Riu, I.; Rizatdinova, F.; Rizvi, E.; Robertson, S. H.; Robichaud-Veronneau, A.; Robinson, D.; Robinson, J. E. M.; Robson, A.; Roda, C.; Rodrigues, L.; Roe, S.; Røhne, O.; Rolli, S.; Romaniouk, A.; Romano, M.; Romero Adam, E.; Rompotis, N.; Ronzani, M.; Roos, L.; Ros, E.; Rosati, S.; Rosbach, K.; Rose, M.; Rose, P.; Rosendahl, P. L.; Rosenthal, O.; Rossetti, V.; Rossi, E.; Rossi, L. P.; Rosten, R.; Rotaru, M.; Roth, I.; Rothberg, J.; Rousseau, D.; Royon, C. R.; Rozanov, A.; Rozen, Y.; Ruan, X.; Rubbo, F.; Rubinskiy, I.; Rud, V. I.; Rudolph, C.; Rudolph, M. S.; Rühr, F.; Ruiz-Martinez, A.; Rurikova, Z.; Rusakovich, N. A.; Ruschke, A.; Rutherfoord, J. P.; Ruthmann, N.; Ryabov, Y. F.; Rybar, M.; Rybkin, G.; Ryder, N. C.; Saavedra, A. F.; Sacerdoti, S.; Saddique, A.; Sadeh, I.; Sadrozinski, H. F.-W.; Sadykov, R.; Safai Tehrani, F.; Sakamoto, H.; Sakurai, Y.; Salamanna, G.; Salamon, A.; Saleem, M.; Salek, D.; Sales De Bruin, P. H.; Salihagic, D.; Salnikov, A.; Salt, J.; Salvatore, D.; Salvatore, F.; Salvucci, A.; Salzburger, A.; Sampsonidis, D.; Sanchez, A.; Sánchez, J.; Sanchez Martinez, V.; Sandaker, H.; Sandbach, R. L.; Sander, H. G.; Sanders, M. P.; Sandhoff, M.; Sandoval, T.; Sandoval, C.; Sandstroem, R.; Sankey, D. P. C.; Sansoni, A.; Santoni, C.; Santonico, R.; Santos, H.; Santoyo Castillo, I.; Sapp, K.; Sapronov, A.; Saraiva, J. G.; Sarrazin, B.; Sartisohn, G.; Sasaki, O.; Sasaki, Y.; Sauvage, G.; Sauvan, E.; Savard, P.; Savu, D. O.; Sawyer, C.; Sawyer, L.; Saxon, D. H.; Saxon, J.; Sbarra, C.; Sbrizzi, A.; Scanlon, T.; Scannicchio, D. A.; Scarcella, M.; Scarfone, V.; Schaarschmidt, J.; Schacht, P.; Schaefer, D.; Schaefer, R.; Schaepe, S.; Schaetzel, S.; Schäfer, U.; Schaffer, A. C.; Schaile, D.; Schamberger, R. D.; Scharf, V.; Schegelsky, V. A.; Scheirich, D.; Schernau, M.; Scherzer, M. I.; Schiavi, C.; Schieck, J.; Schillo, C.; Schioppa, M.; Schlenker, S.; Schmidt, E.; Schmieden, K.; Schmitt, C.; Schmitt, S.; Schneider, B.; Schnellbach, Y. J.; Schnoor, U.; Schoeffel, L.; Schoening, A.; Schoenrock, B. D.; Schorlemmer, A. L. S.; Schott, M.; Schouten, D.; Schovancova, J.; Schramm, S.; Schreyer, M.; Schroeder, C.; Schuh, N.; Schultens, M. J.; Schultz-Coulon, H.-C.; Schulz, H.; Schumacher, M.; Schumm, B. A.; Schune, Ph.; Schwanenberger, C.; Schwartzman, A.; Schwegler, Ph.; Schwemling, Ph.; Schwienhorst, R.; Schwindling, J.; Schwindt, T.; Schwoerer, M.; Sciacca, F. G.; Scifo, E.; Sciolla, G.; Scott, W. G.; Scuri, F.; Scutti, F.; Searcy, J.; Sedov, G.; Sedykh, E.; Seidel, S. C.; Seiden, A.; Seifert, F.; Seixas, J. M.; Sekhniaidze, G.; Sekula, S. J.; Selbach, K. E.; Seliverstov, D. M.; Sellers, G.; Semprini-Cesari, N.; Serfon, C.; Serin, L.; Serkin, L.; Serre, T.; Seuster, R.; Severini, H.; Sfiligoj, T.; Sforza, F.; Sfyrla, A.; Shabalina, E.; Shamim, M.; Shan, L. Y.; Shang, R.; Shank, J. T.; Shapiro, M.; Shatalov, P. B.; Shaw, K.; Shehu, C. Y.; Sherwood, P.; Shi, L.; Shimizu, S.; Shimmin, C. O.; Shimojima, M.; Shiyakova, M.; Shmeleva, A.; Shochet, M. J.; Short, D.; Shrestha, S.; Shulga, E.; Shupe, M. A.; Shushkevich, S.; Sicho, P.; Sidiropoulou, O.; Sidorov, D.; Sidoti, A.; Siegert, F.; Sijacki, Dj.; Silva, J.; Silver, Y.; Silverstein, D.; Silverstein, S. B.; Simak, V.; Simard, O.; Simic, Lj.; Simion, S.; Simioni, E.; Simmons, B.; Simoniello, R.; Simonyan, M.; Sinervo, P.; Sinev, N. B.; Sipica, V.; Siragusa, G.; Sircar, A.; Sisakyan, A. N.; Sivoklokov, S. Yu.; Sjölin, J.; Sjursen, T. B.; Skottowe, H. P.; Skovpen, K. Yu.; Skubic, P.; Slater, M.; Slavicek, T.; Sliwa, K.; Smakhtin, V.; Smart, B. H.; Smestad, L.; Smirnov, S. Yu.; Smirnov, Y.; Smirnova, L. N.; Smirnova, O.; Smith, K. M.; Smizanska, M.; Smolek, K.; Snesarev, A. A.; Snidero, G.; Snyder, S.; Sobie, R.; Socher, F.; Soffer, A.; Soh, D. A.; Solans, C. A.; Solar, M.; Solc, J.; Soldatov, E. Yu.; Soldevila, U.; Solodkov, A. A.; Soloshenko, A.; Solovyanov, O. V.; Solovyev, V.; Sommer, P.; Song, H. Y.; Soni, N.; Sood, A.; Sopczak, A.; Sopko, B.; Sopko, V.; Sorin, V.; Sosebee, M.; Soualah, R.; Soueid, P.; Soukharev, A. M.; South, D.; Spagnolo, S.; Spanò, F.; Spearman, W. R.; Spettel, F.; Spighi, R.; Spigo, G.; Spiller, L. A.; Spousta, M.; Spreitzer, T.; Spurlock, B.; St. Denis, R. D.; Staerz, S.; Stahlman, J.; Stamen, R.; Stamm, S.; Stanecka, E.; Stanek, R. W.; Stanescu, C.; Stanescu-Bellu, M.; Stanitzki, M. M.; Stapnes, S.; Starchenko, E. A.; Stark, J.; Staroba, P.; Starovoitov, P.; Staszewski, R.; Stavina, P.; Steinberg, P.; Stelzer, B.; Stelzer, H. J.; Stelzer-Chilton, O.; Stenzel, H.; Stern, S.; Stewart, G. A.; Stillings, J. A.; Stockton, M. C.; Stoebe, M.; Stoicea, G.; Stolte, P.; Stonjek, S.; Stradling, A. R.; Straessner, A.; Stramaglia, M. E.; Strandberg, J.; Strandberg, S.; Strandlie, A.; Strauss, E.; Strauss, M.; Strizenec, P.; Ströhmer, R.; Strom, D. M.; Stroynowski, R.; Stucci, S. A.; Stugu, B.; Styles, N. A.; Su, D.; Su, J.; Subramaniam, R.; Succurro, A.; Sugaya, Y.; Suhr, C.; Suk, M.; Sulin, V. V.; Sultansoy, S.; Sumida, T.; Sun, S.; Sun, X.; Sundermann, J. E.; Suruliz, K.; Susinno, G.; Sutton, M. R.; Suzuki, Y.; Svatos, M.; Swedish, S.; Swiatlowski, M.; Sykora, I.; Sykora, T.; Ta, D.; Taccini, C.; Tackmann, K.; Taenzer, J.; Taffard, A.; Tafirout, R.; Taiblum, N.; Takai, H.; Takashima, R.; Takeda, H.; Takeshita, T.; Takubo, Y.; Talby, M.; Talyshev, A. A.; Tam, J. Y. C.; Tan, K. G.; Tanaka, J.; Tanaka, R.; Tanaka, S.; Tanaka, S.; Tanasijczuk, A. J.; Tannenwald, B. B.; Tannoury, N.; Tapprogge, S.; Tarem, S.; Tarrade, F.; Tartarelli, G. F.; Tas, P.; Tasevsky, M.; Tashiro, T.; Tassi, E.; Tavares Delgado, A.; Tayalati, Y.; Taylor, F. E.; Taylor, G. N.; Taylor, W.; Teischinger, F. A.; Teixeira Dias Castanheira, M.; Teixeira-Dias, P.; Temming, K. K.; Ten Kate, H.; Teng, P. K.; Teoh, J. J.; Terada, S.; Terashi, K.; Terron, J.; Terzo, S.; Testa, M.; Teuscher, R. J.; Therhaag, J.; Theveneaux-Pelzer, T.; Thomas, J. P.; Thomas-Wilsker, J.; Thompson, E. N.; Thompson, P. D.; Thompson, P. D.; Thompson, R. J.; Thompson, A. S.; Thomsen, L. A.; Thomson, E.; Thomson, M.; Thong, W. M.; Thun, R. P.; Tian, F.; Tibbetts, M. J.; Tikhomirov, V. O.; Tikhonov, Yu. A.; Timoshenko, S.; Tiouchichine, E.; Tipton, P.; Tisserant, S.; Todorov, T.; Todorova-Nova, S.; Toggerson, B.; Tojo, J.; Tokár, S.; Tokushuku, K.; Tollefson, K.; Tomlinson, L.; Tomoto, M.; Tompkins, L.; Toms, K.; Topilin, N. D.; Torrence, E.; Torres, H.; Torró Pastor, E.; Toth, J.; Touchard, F.; Tovey, D. R.; Tran, H. L.; Trefzger, T.; Tremblet, L.; Tricoli, A.; Trigger, I. M.; Trincaz-Duvoid, S.; Tripiana, M. F.; Trischuk, W.; Trocmé, B.; Troncon, C.; Trottier-McDonald, M.; Trovatelli, M.; True, P.; Trzebinski, M.; Trzupek, A.; Tsarouchas, C.; Tseng, J. C.-L.; Tsiareshka, P. V.; Tsionou, D.; Tsipolitis, G.; Tsirintanis, N.; Tsiskaridze, S.; Tsiskaridze, V.; Tskhadadze, E. G.; Tsukerman, I. I.; Tsulaia, V.; Tsuno, S.; Tsybychev, D.; Tudorache, A.; Tudorache, V.; Tuna, A. N.; Tupputi, S. A.; Turchikhin, S.; Turecek, D.; Turk Cakir, I.; Turra, R.; Tuts, P. M.; Tykhonov, A.; Tylmad, M.; Tyndel, M.; Uchida, K.; Ueda, I.; Ueno, R.; Ughetto, M.; Ugland, M.; Uhlenbrock, M.; Ukegawa, F.; Unal, G.; Undrus, A.; Unel, G.; Ungaro, F. C.; Unno, Y.; Unverdorben, C.; Urbaniec, D.; Urquijo, P.; Usai, G.; Usanova, A.; Vacavant, L.; Vacek, V.; Vachon, B.; Valencic, N.; Valentinetti, S.; Valero, A.; Valery, L.; Valkar, S.; Valladolid Gallego, E.; Vallecorsa, S.; Valls Ferrer, J. A.; Van Den Wollenberg, W.; Van Der Deijl, P. C.; van der Geer, R.; van der Graaf, H.; Van Der Leeuw, R.; van der Ster, D.; van Eldik, N.; van Gemmeren, P.; Van Nieuwkoop, J.; van Vulpen, I.; van Woerden, M. C.; Vanadia, M.; Vandelli, W.; Vanguri, R.; Vaniachine, A.; Vankov, P.; Vannucci, F.; Vardanyan, G.; Vari, R.; Varnes, E. W.; Varol, T.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vazeille, F.; Vazquez Schroeder, T.; Veatch, J.; Veloso, F.; Velz, T.; Veneziano, S.; Ventura, A.; Ventura, D.; Venturi, M.; Venturi, N.; Venturini, A.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J. C.; Vest, A.; Vetterli, M. C.; Viazlo, O.; Vichou, I.; Vickey, T.; Vickey Boeriu, O. E.; Viehhauser, G. H. A.; Viel, S.; Vigne, R.; Villa, M.; Villaplana Perez, M.; Vilucchi, E.; Vincter, M. G.; Vinogradov, V. B.; Virzi, J.; Vivarelli, I.; Vives Vaque, F.; Vlachos, S.; Vladoiu, D.; Vlasak, M.; Vogel, A.; Vogel, M.; Vokac, P.; Volpi, G.; Volpi, M.; von der Schmitt, H.; von Radziewski, H.; von Toerne, E.; Vorobel, V.; Vorobev, K.; Vos, M.; Voss, R.; Vossebeld, J. H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Vu Anh, T.; Vuillermet, R.; Vukotic, I.; Vykydal, Z.; Wagner, P.; Wagner, W.; Wahlberg, H.; Wahrmund, S.; Wakabayashi, J.; Walder, J.; Walker, R.; Walkowiak, W.; Wall, R.; Waller, P.; Walsh, B.; Wang, C.; Wang, C.; Wang, F.; Wang, H.; Wang, H.; Wang, J.; Wang, J.; Wang, K.; Wang, R.; Wang, S. M.; Wang, T.; Wang, X.; Wanotayaroj, C.; Warburton, A.; Ward, C. P.; Wardrope, D. R.; Warsinsky, M.; Washbrook, A.; Wasicki, C.; Watkins, P. M.; Watson, A. T.; Watson, I. J.; Watson, M. F.; Watts, G.; Watts, S.; Waugh, B. M.; Webb, S.; Weber, M. S.; Weber, S. W.; Webster, J. S.; Weidberg, A. R.; Weigell, P.; Weinert, B.; Weingarten, J.; Weiser, C.; Weits, H.; Wells, P. S.; Wenaus, T.; Wendland, D.; Weng, Z.; Wengler, T.; Wenig, S.; Wermes, N.; Werner, M.; Werner, P.; Wessels, M.; Wetter, J.; Whalen, K.; White, A.; White, M. J.; White, R.; White, S.; Whiteson, D.; Wicke, D.; Wickens, F. 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L.; Yildirim, E.; Yilmaz, M.; Yoosoofmiya, R.; Yorita, K.; Yoshida, R.; Yoshihara, K.; Young, C.; Young, C. J. S.; Youssef, S.; Yu, D. R.; Yu, J.; Yu, J. M.; Yu, J.; Yuan, L.; Yurkewicz, A.; Yusuff, I.; Zabinski, B.; Zaidan, R.; Zaitsev, A. M.; Zaman, A.; Zambito, S.; Zanello, L.; Zanzi, D.; Zeitnitz, C.; Zeman, M.; Zemla, A.; Zengel, K.; Zenin, O.; Ženiš, T.; Zerwas, D.; Zevi della Porta, G.; Zhang, D.; Zhang, F.; Zhang, H.; Zhang, J.; Zhang, L.; Zhang, X.; Zhang, Z.; Zhao, Z.; Zhemchugov, A.; Zhong, J.; Zhou, B.; Zhou, L.; Zhou, N.; Zhu, C. G.; Zhu, H.; Zhu, J.; Zhu, Y.; Zhuang, X.; Zhukov, K.; Zibell, A.; Zieminska, D.; Zimine, N. I.; Zimmermann, C.; Zimmermann, R.; Zimmermann, S.; Zimmermann, S.; Zinonos, Z.; Ziolkowski, M.; Zobernig, G.; Zoccoli, A.; zur Nedden, M.; Zurzolo, G.; Zutshi, V.; Zwalinski, L.

2015-09-01

Measurements of the centrality and rapidity dependence of inclusive jet production in √{sNN} = 5.02 TeV proton-lead (p + Pb) collisions and the jet cross-section in √{ s} = 2.76 TeV proton-proton collisions are presented. These quantities are measured in datasets corresponding to an integrated luminosity of 27.8 nb-1 and 4.0 pb-1, respectively, recorded with the ATLAS detector at the Large Hadron Collider in 2013. The p + Pb collision centrality was characterised using the total transverse energy measured in the pseudorapidity interval - 4.9 < η < - 3.2 in the direction of the lead beam. Results are presented for the double-differential per-collision yields as a function of jet rapidity and transverse momentum (pT) for minimum-bias and centrality-selected p + Pb collisions, and are compared to the jet rate from the geometric expectation. The total jet yield in minimum-bias events is slightly enhanced above the expectation in a pT-dependent manner but is consistent with the expectation within uncertainties. The ratios of jet spectra from different centrality selections show a strong modification of jet production at all pT at forward rapidities and for large pT at mid-rapidity, which manifests as a suppression of the jet yield in central events and an enhancement in peripheral events. These effects imply that the factorisation between hard and soft processes is violated at an unexpected level in proton-nucleus collisions. Furthermore, the modifications at forward rapidities are found to be a function of the total jet energy only, implying that the violations may have a simple dependence on the hard parton-parton kinematics.

GenoCore: A simple and fast algorithm for core subset selection from large genotype datasets.

PubMed

Jeong, Seongmun; Kim, Jae-Yoon; Jeong, Soon-Chun; Kang, Sung-Taeg; Moon, Jung-Kyung; Kim, Namshin

2017-01-01

Selecting core subsets from plant genotype datasets is important for enhancing cost-effectiveness and to shorten the time required for analyses of genome-wide association studies (GWAS), and genomics-assisted breeding of crop species, etc. Recently, a large number of genetic markers (>100,000 single nucleotide polymorphisms) have been identified from high-density single nucleotide polymorphism (SNP) arrays and next-generation sequencing (NGS) data. However, there is no software available for picking out the efficient and consistent core subset from such a huge dataset. It is necessary to develop software that can extract genetically important samples in a population with coherence. We here present a new program, GenoCore, which can find quickly and efficiently the core subset representing the entire population. We introduce simple measures of coverage and diversity scores, which reflect genotype errors and genetic variations, and can help to select a sample rapidly and accurately for crop genotype dataset. Comparison of our method to other core collection software using example datasets are performed to validate the performance according to genetic distance, diversity, coverage, required system resources, and the number of selected samples. GenoCore selects the smallest, most consistent, and most representative core collection from all samples, using less memory with more efficient scores, and shows greater genetic coverage compared to the other software tested. GenoCore was written in R language, and can be accessed online with an example dataset and test results at https://github.com/lovemun/Genocore.

Selective Catalytic Combustion Sensors for Reactive Organic Analysis

NASA Technical Reports Server (NTRS)

Innes, W. B.

1971-01-01

Sensors involving a vanadia-alumina catalyst bed-thermocouple assembly satisfy requirements for simple, reproducible and rapid continuous analysis or reactive organics. Responses generally increase with temperature to 400 C and increase to a maximum with flow rate/catalyst volume. Selectivity decreases with temperature. Response time decreases with flow rate and increases with catalyst volume. At chosen optimum conditions calculated response which is additive and linear agrees better with photochemical reactivity than other methods for various automotive sources, and response to vehicle exhaust is insensitive to flow rate. Application to measurement of total reactive organics in vehicle exhaust as well as for gas chromatography detection illustrate utility. The approach appears generally applicable to high thermal effect reactions involving first order kinetics.

Effect of genetic algorithm as a variable selection method on different chemometric models applied for the analysis of binary mixture of amoxicillin and flucloxacillin: A comparative study

NASA Astrophysics Data System (ADS)

Attia, Khalid A. M.; Nassar, Mohammed W. I.; El-Zeiny, Mohamed B.; Serag, Ahmed

2016-03-01

Different chemometric models were applied for the quantitative analysis of amoxicillin (AMX), and flucloxacillin (FLX) in their binary mixtures, namely, partial least squares (PLS), spectral residual augmented classical least squares (SRACLS), concentration residual augmented classical least squares (CRACLS) and artificial neural networks (ANNs). All methods were applied with and without variable selection procedure (genetic algorithm GA). The methods were used for the quantitative analysis of the drugs in laboratory prepared mixtures and real market sample via handling the UV spectral data. Robust and simpler models were obtained by applying GA. The proposed methods were found to be rapid, simple and required no preliminary separation steps.

Context-dependent decision-making: a simple Bayesian model

PubMed Central

Lloyd, Kevin; Leslie, David S.

2013-01-01

Many phenomena in animal learning can be explained by a context-learning process whereby an animal learns about different patterns of relationship between environmental variables. Differentiating between such environmental regimes or ‘contexts’ allows an animal to rapidly adapt its behaviour when context changes occur. The current work views animals as making sequential inferences about current context identity in a world assumed to be relatively stable but also capable of rapid switches to previously observed or entirely new contexts. We describe a novel decision-making model in which contexts are assumed to follow a Chinese restaurant process with inertia and full Bayesian inference is approximated by a sequential-sampling scheme in which only a single hypothesis about current context is maintained. Actions are selected via Thompson sampling, allowing uncertainty in parameters to drive exploration in a straightforward manner. The model is tested on simple two-alternative choice problems with switching reinforcement schedules and the results compared with rat behavioural data from a number of T-maze studies. The model successfully replicates a number of important behavioural effects: spontaneous recovery, the effect of partial reinforcement on extinction and reversal, the overtraining reversal effect, and serial reversal-learning effects. PMID:23427101

Context-dependent decision-making: a simple Bayesian model.

PubMed

Lloyd, Kevin; Leslie, David S

2013-05-06

Many phenomena in animal learning can be explained by a context-learning process whereby an animal learns about different patterns of relationship between environmental variables. Differentiating between such environmental regimes or 'contexts' allows an animal to rapidly adapt its behaviour when context changes occur. The current work views animals as making sequential inferences about current context identity in a world assumed to be relatively stable but also capable of rapid switches to previously observed or entirely new contexts. We describe a novel decision-making model in which contexts are assumed to follow a Chinese restaurant process with inertia and full Bayesian inference is approximated by a sequential-sampling scheme in which only a single hypothesis about current context is maintained. Actions are selected via Thompson sampling, allowing uncertainty in parameters to drive exploration in a straightforward manner. The model is tested on simple two-alternative choice problems with switching reinforcement schedules and the results compared with rat behavioural data from a number of T-maze studies. The model successfully replicates a number of important behavioural effects: spontaneous recovery, the effect of partial reinforcement on extinction and reversal, the overtraining reversal effect, and serial reversal-learning effects.

A simple and rapid method for direct determination of Al(III) based on the enhanced resonance Rayleigh scattering of hemin-functionalized graphene-Al(III) system

NASA Astrophysics Data System (ADS)

Ling, Yu; Chen, Ling Xiao; Dong, Jiang Xue; Li, Nian Bing; Luo, Hong Qun

2016-03-01

A novel method for direct determination of Al(III) by using hemin-functionalized graphene (H-GO) has been established based on the enhancement of resonance Rayleigh scattering (RRS) intensity. The characteristics of RRS spectra, the optimum reaction conditions, and the reaction mechanism have been investigated. In this experiment, the Al(III) would exist in sol-gel Al(OH)3 species under the condition of pH 5.9 in aqueous solutions. When H-GO existed in the solution, the sol-gel Al(OH)3 would react with H-GO and result in enhancement of RRS intensity, owing to the enhanced hydrophobicity of H-GO surface. Therefore, a simple and rapid sensor for Al(III) was developed. The increased intensity of RRS is directly proportional to the concentration of Al(III) in the range of 10 nM-6 μM, along with a detection limit of 0.87 nM. Moreover, the sensor has been applied to determination of Al(III) concentration in real water and aspirin tablet samples with satisfactory results. Therefore, the proposed method is promising as an effective means for selective and sensitive determination of Al(III).

Female penis, male vagina, and their correlated evolution in a cave insect.

PubMed

Yoshizawa, Kazunori; Ferreira, Rodrigo L; Kamimura, Yoshitaka; Lienhard, Charles

2014-05-05

Sex-specific elaborations are common in animals and have attracted the attention of many biologists, including Darwin [1]. It is accepted that sexual selection promotes the evolution of sex-specific elaborations. Due to the faster replenishment rate of gametes, males generally have higher potential reproductive and optimal mating rates than females. Therefore, sexual selection acts strongly on males [2], leading to the rapid evolution and diversification of male genitalia [3]. Male genitalia are sometimes used as devices for coercive holding of females as a result of sexual conflict over mating [4, 5]. In contrast, female genitalia are usually simple. Here we report the reversal of intromittent organs in the insect genus Neotrogla (Psocodea: Prionoglarididae) from Brazilian caves. Females have a highly elaborate, penis-like structure, the gynosome, while males lack an intromittent organ. The gynosome has species-specific elaborations, such as numerous spines that fit species-specific pouches in the simple male genital chamber. During prolonged copulation (~40-70 hr), a large and potentially nutritious ejaculate is transferred from the male via the gynosome. The correlated genital evolution in Neotrogla is probably driven by reversed sexual selection with females competing for seminal gifts. Nothing similar is known among sex-role reversed animals. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cyclic Solvent Vapor Annealing for Rapid, Robust Vertical Orientation of Features in BCP Thin Films

NASA Astrophysics Data System (ADS)

Paradiso, Sean; Delaney, Kris; Fredrickson, Glenn

2015-03-01

Methods for reliably controlling block copolymer self assembly have seen much attention over the past decade as new applications for nanostructured thin films emerge in the fields of nanopatterning and lithography. While solvent assisted annealing techniques are established as flexible and simple methods for achieving long range order, solvent annealing alone exhibits a very weak thermodynamic driving force for vertically orienting domains with respect to the free surface. To address the desire for oriented features, we have investigated a cyclic solvent vapor annealing (CSVA) approach that combines the mobility benefits of solvent annealing with selective stress experienced by structures oriented parallel to the free surface as the film is repeatedly swollen with solvent and dried. Using dynamical self-consistent field theory (DSCFT) calculations, we establish the conditions under which the method significantly outperforms both static and cyclic thermal annealing and implicate the orientation selection as a consequence of the swelling/deswelling process. Our results suggest that CSVA may prove to be a potent method for the rapid formation of highly ordered, vertically oriented features in block copolymer thin films.

Rapid screening of selective serotonin re-uptake inhibitors in urine samples using solid-phase microextraction gas chromatography-mass spectrometry.

PubMed

Salgado-Petinal, Carmen; Lamas, J Pablo; Garcia-Jares, Carmen; Llompart, Maria; Cela, Rafael

2005-07-01

In this paper a solid-phase microextraction-gas chromatography-mass spectrometry (SPME-GC-MS) method is proposed for a rapid analysis of some frequently prescribed selective serotonin re-uptake inhibitors (SSRI)-venlafaxine, fluvoxamine, mirtazapine, fluoxetine, citalopram, and sertraline-in urine samples. The SPME-based method enables simultaneous determination of the target SSRI after simple in-situ derivatization of some of the target compounds. Calibration curves in water and in urine were validated and statistically compared. This revealed the absence of matrix effect and, in consequence, the possibility of quantifying SSRI in urine samples by external water calibration. Intra-day and inter-day precision was satisfactory for all the target compounds (relative standard deviation, RSD, <14%) and the detection limits achieved were <0.4 ng mL(-1) urine. The time required for the SPME step and for GC analysis (30 min each) enables high throughput. The method was applied to real urine samples from different patients being treated with some of these pharmaceuticals. Some SSRI metabolites were also detected and tentatively identified.

Modular Approach to Select Bacteriophages Targeting Pseudomonas aeruginosa for Their Application to Children Suffering With Cystic Fibrosis

PubMed Central

Krylov, Victor; Shaburova, Olga; Pleteneva, Elena; Bourkaltseva, Maria; Krylov, Sergey; Kaplan, Alla; Chesnokova, Elena; Kulakov, Leonid; Magill, Damian; Polygach, Olga

2016-01-01

This review discusses the potential application of bacterial viruses (phage therapy) toward the eradication of antibiotic resistant Pseudomonas aeruginosa in children with cystic fibrosis (CF). In this regard, several potential relationships between bacteria and their bacteriophages are considered. The most important aspect that must be addressed with respect to phage therapy of bacterial infections in the lungs of CF patients is in ensuring the continuity of treatment in light of the continual occurrence of resistant bacteria. This depends on the ability to rapidly select phages exhibiting an enhanced spectrum of lytic activity among several well-studied phage groups of proven safety. We propose a modular based approach, utilizing both mono-species and hetero-species phage mixtures. With an approach involving the visual recognition of characteristics exhibited by phages of well-studied phage groups on lawns of the standard P. aeruginosa PAO1 strain, the simple and rapid enhancement of the lytic spectrum of cocktails is permitted, allowing the development of tailored preparations for patients capable of circumventing problems associated with phage resistant bacterial mutants. PMID:27790211

Rapid Determination of Salmonella in Samples of Egg Noodles, Cake Mixes, and Candies

PubMed Central

Banwart, George J.; Kreitzer, Madeleine J.

1969-01-01

A glass apparatus system was compared with a standard enrichment broth-selective agar method to test samples of egg noodles, cake mixes, and candy for the presence or absence of salmonellae. The glass apparatus system used fermentation of mannitol, production of H2S, or motility, in conjunction with a serological test of flagellar antigens, to detect salmonellae. No salmonellae were detected in 173 samples of food products. Of these samples, 171 were found to be Salmonella-negative after 48 hr with the glass apparatus system. After 72 hr, the standard Salmonella procedure yielded 38 samples which produced Salmonella false-positive results on selective agars. Inoculation of samples with cultures of Salmonella showed that approximately one inoculated cell could be detected after 48 hr of incubation with the glass apparatus. The standard Salmonella test requires a minimum of 72 hr for completion. Compared with the standard Salmonella test, the glass apparatus system is a more rapid and simple system that can be used to determine the presence or absence of Salmonella in these food products. Images PMID:5370460

Detection of Campylobacter jejuni added to foods by using a combined selective enrichment and nucleic acid sequence-based amplification (NASBA).

PubMed Central

Uyttendaele, M; Schukkink, R; van Gemen, B; Debevere, J

1995-01-01

An assay to detect Campylobacter jejuni in foods that uses a short selective enrichment culture, a simple and rapid isolation procedure, NASBA amplification of RNA, and a nonradioactive in solution hybridization was studied. The presence of high numbers of indigenous flora affected the sensitivity of the assay. However, detection of C. jejuni was possible up to a ratio of indigenous flora to C. jejuni of 10,000:1. Interference by food components was eliminated by centrifugation following the enrichment step. Fourteen food samples artificially inoculated with C. jejuni (1 to 1,000 CFU/10 g) were analyzed with the NASBA assay and the conventional culture method with Campylobacter charcoal differential agar (CCDA). A few false-negative results were obtained by both NASBA (1.42%) and CCDA (2.86%) isolation. Yet the use of enrichment culture and NASBA shortened the analysis time from 6 days to 26 h. The relative simplicity and rapidity of the NASBA assay make it an attractive alternative for detection of C. jejuni in food samples. PMID:7747955

A Simple and Green Route for Room-Temperature Synthesis of Gold Nanoparticles and Selective Colorimetric Detection of Cysteine.

PubMed

Bagci, Pelin Onsekizoglu; Wang, Yi-Cheng; Gunasekaran, Sundaram

2015-09-01

Gold nanoparticles (AuNPs) were synthesized at room temperature following a simple, rapid, and green route using fresh-squeezed apple juice as a reducing reagent. The optimal AuNPs, based on the particle color, stability, and color change suitable for colorimetric detection of cysteine (Cys), are synthesized using 5 mL of 10% apple juice, 1 mL of 10 mM gold precursor solution, and 1 mL of 0.1 M NaOH. Under this set of parameters, the AuNPs are synthesized within 30 min at room temperature. The average size (11.1 ± 3.2 nm) and ζ potential (-36.5 mV) of the AuNPs synthesized were similar to those of AuNPs prepared via the conventional citrate-reduction method. In the presence of Cys, unlike with any other amino acid, the AuNPs aggregated, possibly due to the gold-sulfur covalent interaction, yielding red-to-purple color change of the sample solution. The red-shift of the localized surface plasmon resonance peak of the AuNPs responsible for the color change was recorded by UV-vis spectrometer. The effect of other potential interferents such as glucose, ascorbic acid, K(+) , Na(+) , Ca(2+) , Zn(2+) , Ag(+) , Ni(2+) , Cu(2+) , Co(2+) , and Hg(2+) were also examined. The results show that AuNPs can be used to selectively detect and measure Cys with a linear dependency in the range of 2 to 100 μM and a limit of detection (signal-to-noise ratio > 3) of 50 nM. The results suggest that the green-synthesized AuNPs are useful for simple, rapid, and sensitive colorimetric detection of Cys, which is an essential amino acid in food and biological systems. © 2015 Institute of Food Technologists®

Selective Discrimination of Key Enzymes of Pathogenic and Nonpathogenic Bacteria on Autonomously Reporting Shape-Encoded Hydrogel Patterns.

PubMed

Jia, Zhiyuan; Sukker, Issa; Müller, Mareike; Schönherr, Holger

2018-02-14

This work reports on a new approach to rapidly and selectively detect and discriminate enzymes of pathogenic from those of nonpathogenic bacteria using a patterned autonomously reporting hydrogel on a transparent support, in which the selectivity has been encoded by the pattern shape to enable facile detection by a color change at one single wavelength. In particular, enzyme-responsive chitosan hydrogel layers that report the presence of the enzymes β-glucuronidase (β-Gus) and β-galactosidase (β-Gal), produced by the nonvirulent Escherichia coli K12 and the food-borne biosafety level 3 pathogen enterohemorrhagic E. coli, respectively, via the blue color of an indigo dye were patterned by two complementary strategies. The comparison of the functionalization of patterned chitosan patches on a solid support with two chromogenic substrates on one hand and the area-selective conjugation of the substrates on the other hand showed that the two characteristic enzymes could indeed be rapidly and selectively discriminated. The limits of detection of the highly stable sensing layers for an observation time of 60 min using a spectrophotometer correspond to enzyme concentrations of β-Gus and β-Gal of ≤5 and ≤3 nM, respectively, and to ≤62 and ≤33 nM for bare eye detection in nonoptimized sensor patches. These results confirm the applicability of this approach, which is compatible with the simple measurement of optical density at one single wavelength only as well as with parallel, multiplexed detection, to differentiate the enzymes secreted by a highly pathogenic E. coli from a nonpathogenic E. coli on the basis of specifically secreted enzymes. Hence, a general approach for the rapid and selective detection of enzymes of different bacterial species for potential applications in food safety as well as point-of-care microbiological diagnostics is described.

Setaria viridis floral-dip: A simple and rapid Agrobacterium-medicated transformation method

USDA-ARS?s Scientific Manuscript database

Setaria viridis was recently described as a new monocotyledonous model species for C4 photosynthesis research and genetic transformation. It has biological attributes (rapid life cycle, small genome, diploid, short stature and simple growth requirements) that make it suitable for use as a model plan...

A RAPID AND SIMPLE PHOSPHOLIPASE A ASSAY,

DTIC Science & Technology

A simple and rapid method for the assay of phospholipase A was developed. As a substrate fresh egg yolk is used which is hydrolyzed by snake venom...phospholipase A at a 10-20 x faster rate than pure lecithin . The released fatty acids, after extraction with appropriate solvents are titrated

Rapid and sensitive detection of ketamine in blood using novel fluorescence genosensor.

PubMed

Ding, Yanjun; Li, Xingmei; Guo, Yadong; Yan, Jie; Ling, Jiang; Li, Weichen; Lan, Lingmei; Chang, Yunfeng; Cai, Jifeng; Zha, Lagabaiyla

2017-12-01

In recent years, drug abuse has been considered as a most challenging social problem that aroused public attention. Ketamine has increased in unregulated use as a 'recreational drug' in teenagers. However, there is no suitable and maneuverable detection method for ketamine in situ at the moment. Fluorescence sensor technique, with predominant recognition and simple operation, is a good potential application in drug detection. Here, we first reported a highly sensitive and selective fluorescence genosensor for rapid detection of ketamine based on DNA-templated silver nanoclusters (DNA-AgNCs) probes, in which the DNA sequence could specially recognize ketamine with high affinity. Parameters affecting detection efficiency were investigated and optimized. Under optimum conditions, the as-prepared genosensor can allow for the determination of ketamine in the concentration range of 0.0001-20 μg/mL with two linear equations: one is y = 2.84x-7.139 (R 2 = 0.987) for 0.0001-0.1 μg/mL, and the other is y = 1.87x-0.091 (R 2 = 0.962) for 0.1-20 μg/mL, and the estimated detection limit of ketamine is 0.06 ng/mL. Moreover, the feasibility of this proposed method was also demonstrated by analyzing forensic blood samples. Compared with official gas chromatography/mass spectrometry (GC/MS), this fluorescence genosensor is simple, rapid, and accurate for quantitative determination of ketamine in blood for pharmaceutical and forensic analysis. Overall, it is the first report on a fluorescence genosensor for detecting ketamine directly in blood. This research may provide a new insight for the analyst to band fluorescence genosensor technology together with drug monitoring in the battle against drug abuse and forensic examination. Graphical abstract High selectively detection of ketamine using a novel fluorescence genosensor based on DNA-AgNCs probe.

Bacteria-instructed synthesis of polymers for self-selective microbial binding and labelling

PubMed Central

Magennis, E. Peter; Fernandez-Trillo, Francisco; Sui, Cheng; Spain, Sebastian G.; Bradshaw, David; Churchley, David; Mantovani, Giuseppe; Winzer, Klaus; Alexander, Cameron

2014-01-01

The detection and inactivation of pathogenic strains of bacteria continues to be an important therapeutic goal. Hence, there is a need for materials that can bind selectively to specific microorganisms, for diagnostic or anti-infective applications, but which can be formed from simple and inexpensive building blocks. Here, we exploit bacterial redox systems to induce a copper-mediated radical polymerisation of synthetic monomers at cell surfaces, generating polymers in situ that bind strongly to the microorganisms which produced them. This ‘bacteria-instructed synthesis’ can be carried out with a variety of microbial strains, and we show that the polymers produced are self-selective binding agents for the ‘instructing’ cell types. We further expand on the bacterial redox chemistries to ‘click’ fluorescent reporters onto polymers directly at the surfaces of a range of clinical isolate strains, allowing rapid, facile and simultaneous binding and visualisation of pathogens. PMID:24813421

Bacteria-instructed synthesis of polymers for self-selective microbial binding and labelling

NASA Astrophysics Data System (ADS)

Magennis, E. Peter; Fernandez-Trillo, Francisco; Sui, Cheng; Spain, Sebastian G.; Bradshaw, David J.; Churchley, David; Mantovani, Giuseppe; Winzer, Klaus; Alexander, Cameron

2014-07-01

The detection and inactivation of pathogenic strains of bacteria continues to be an important therapeutic goal. Hence, there is a need for materials that can bind selectively to specific microorganisms for diagnostic or anti-infective applications, but that can be formed from simple and inexpensive building blocks. Here, we exploit bacterial redox systems to induce a copper-mediated radical polymerization of synthetic monomers at cell surfaces, generating polymers in situ that bind strongly to the microorganisms that produced them. This ‘bacteria-instructed synthesis’ can be carried out with a variety of microbial strains, and we show that the polymers produced are self-selective binding agents for the ‘instructing’ cell types. We further expand on the bacterial redox chemistries to ‘click’ fluorescent reporters onto polymers directly at the surfaces of a range of clinical isolate strains, allowing rapid, facile and simultaneous binding and visualization of pathogens.

Experimental Evolution as a High-Throughput Screen for Genetic Adaptations.

PubMed

Cooper, Vaughn S

2018-06-27

Experimental evolution is a method in which populations of organisms, often microbes, are founded by one or more ancestors of known genotype and then propagated under controlled conditions to study the evolutionary process. These evolving populations are influenced by all population genetic forces, including selection, mutation, drift, and recombination, and the relative contributions of these forces may be seen as mysterious. Here, I describe why the outcomes of experimental evolution should be viewed with greater certainty because the force of selection typically dominates. Importantly, any mutant rising rapidly to high frequency in large populations must have acquired adaptive traits in the selective environment. Sequencing the genomes of these mutants can identify genes or pathways that contribute to an adaptation. I review the logic and simple mathematics why this evolve-and-resequence approach is a powerful way to find the mutations or mutation combinations that best increase fitness in any new environment. Copyright © 2018 Cooper.

Application of oxybutynin selective sensors for monitoring the dissolution profile and assay of pharmaceutical dosage forms.

PubMed

El Hamshary, Marwa S; Salem, Omar H; El Nashar, Rasha M

2010-01-01

Two ion-selective sensors of the plastic membrane type were prepared for the determination of oxybutynin hydrochloride (OxCl). They depend on the incorporation of the ion-associates with phosphotungestic acid or phosphomolybdic acid in a PVC matrix. A comparative study is made between their performance characteristics in batch and FIA conditions. The sensors have nearly the same usable concentration, temperature and pH range. They have a wide range of selectivity and can be applied for the determination of the relevant drug with nearly the same precision and accuracy in vitro. Dissolution testing was applied using the sensors; this offers a simple, rapid, cheap way out of sophisticated and high cost instruments used in the pharmacopeial method using HPLC. The investigated drug was determined in its pure and pharmaceutical preparations. The results were accurate and precise, as indicated by the recovery values and coefficients of variation.

A rapid and highly selective method for the estimation of pyro-, tri- and orthophosphates.

PubMed

Kamat, D R; Savant, V V; Sathyanarayana, D N

1995-03-01

A rapid, highly selective and simple method has been developed for the quantitative determination of pyro-, tri- and orthophosphates. The method is based on the formation of a solid complex of bis(ethylenediamine)cobalt(III) species with pyrophosphate at pH 4.2-4.3, with triphosphate at pH 2.0-2.1 and with orthophosphate at pH 8.2-8.6. The proposed method for pyro- and triphosphates differs from the available method, which is based on the formation of an adduct with tris(ethylenediamine)cobalt(III) species. The complexes have the composition [Co(en)(2)HP(2)O(7)]4H(2)O and [Co(en)(2)H(2)P(3)O(10)]2H(2)O, respectively. The precipitation is instantaneous and quantitative under the recommended optimum conditions giving 99.5% gravimetric yield in both cases. There is no interferences from orthophosphate, trimetaphosphate and pyrophosphate species in the triphosphate estimation up to 5% of each component. The efficacy of the method has been established by determining pyrophosphate and triphosphate contents in various matrices. In the case of orthophosphate, the proposed method differs from the available methods such as ammonium phosphomolybdate, vanadophosphomolybdate and quinoline phosphomolybdate, which are based on the formation of a precipitate, followed by either titrimetry or gravimetry. The precipitation is instantaneous and the method is simple. Under the recommended pH and other reaction conditions, gravimetric yields of 99.6-100% are obtainable. The method is applicable to orthophosphoric acid and a variety of phosphate salts.

The role of experiments in understanding fishery-induced evolution

PubMed Central

Conover, David O; Baumann, Hannes

2009-01-01

Evidence of fishery-induced evolution has been accumulating rapidly from various avenues of investigation. Here we review the knowledge gained from experimental approaches. The strength of experiments is in their ability to disentangle genetic from environmental differences. Common garden experiments have provided direct evidence of adaptive divergence in the wild and therefore the evolvability of various traits that influence production in numerous species. Most of these cases involve countergradient variation in physiological, life history, and behavioral traits. Selection experiments have provided examples of rapid life history evolution and, more importantly, that fishery-induced selection pressures cause simultaneous divergence of not one but a cluster of genetically and phenotypically correlated traits that include physiology, behavior, reproduction, and other life history characters. The drawbacks of experiments are uncertainties in the scale-up from small, simple environments to larger and more complex systems; the concern that taxons with short life cycles used for experimental research are atypical of those of harvested species; and the difficulty of adequately simulating selection due to fishing. Despite these limitations, experiments have contributed greatly to our understanding of fishery-induced evolution on both empirical and theoretical levels. Future advances will depend on integrating knowledge from experiments with those from modeling, field studies, and molecular genetic approaches. PMID:25567880

Boronate affinity-based surface molecularly imprinted polymers using glucose as fragment template for excellent recognition of glucosides.

PubMed

Peng, Mijun; Xiang, Haiyan; Hu, Xin; Shi, Shuyun; Chen, Xiaoqing

2016-11-25

Rapid and efficient extraction of bioactive glycosides from complex natural origins poses a difficult challenge, and then is often inherent bottleneck for their highly utilization. Herein, we propose a strategy to fabricate boronate affinity based surface molecularly imprinted polymers (MIPs) for excellent recognition of glucosides. d-glucose was used as fragment template. Boronic acid, dynamic covalent binding with d-glucose under different pH conditions, was selected as functional monomer to improve specificity. Fe 3 O 4 solid core for surface imprinting using tetraethyl orthosilicate (TEOS) as crosslinker could control imprinted shell thickness for favorable adsorption capacity and satisfactory mass transfer rate, improve hydrophilicity, separate easily by a magnet. Model adsorption studies showed that the resulting MIPs show specific recognition of glucosides. The equilibrium data fitted well to Langmuir equation and the adsorption process could be described by pseudo-second order model. Furthermore, the MIPs were successfully applied for selective extraction of three flavonoid glucosides (daidzin, glycitin, and genistin) from soybean. Results indicated that selective extraction of glucosides from complex aqueous media based on the prepared MIPs is simple, rapid, efficient and specific. Moreover, this method opens up a universal route for imprinting saccharide with cis-diol group for glycosides recognition. Copyright © 2016 Elsevier B.V. All rights reserved.

The genetic architecture of ecological adaptation: intraspecific variation in host plant use by the lepidopteran crop pest Chloridea virescens.

PubMed

Oppenheim, Sara J; Gould, Fred; Hopper, Keith R

2018-03-01

Intraspecific variation in ecologically important traits is a cornerstone of Darwin's theory of evolution by natural selection. The evolution and maintenance of this variation depends on genetic architecture, which in turn determines responses to natural selection. Some models suggest that traits with complex architectures are less likely to respond to selection than those with simple architectures, yet rapid divergence has been observed in such traits. The simultaneous evolutionary lability and genetic complexity of host plant use in the Lepidopteran subfamily Heliothinae suggest that architecture may not constrain ecological adaptation in this group. Here we investigate the response of Chloridea virescens, a generalist that feeds on diverse plant species, to selection for performance on a novel host, Physalis angulata (Solanaceae). P. angulata is the preferred host of Chloridea subflexa, a narrow specialist on the genus Physalis. In previous experiments, we found that the performance of C. subflexa on P. angulata depends on many loci of small effect distributed throughout the genome, but whether the same architecture would be involved in the generalist's adoption of P. angulata was unknown. Here we report a rapid response to selection in C. virescens for performance on P. angulata, and establish that the genetic architecture of intraspecific variation is quite similar to that of the interspecific differences in terms of the number, distribution, and effect sizes of the QTL involved. We discuss the impact of genetic architecture on the ability of Heliothine moths to respond to varying ecological selection pressures.

Simple, Inexpensive, and Rapid Way to Produce Bacillus subtilis Spores for the Guthrie Bioassay

PubMed Central

Franklin, Martha L.; Clark, William A.

1981-01-01

Esculin agar has been found to be a simple, inexpensive, rapid, and reliable means to promote production of spores of inhibitor-sensitive clones of Bacillus subtilis strains ATCC 6051 and 6633 for use in the Guthrie bioassay screening tests for genetic metabolic disorders. Images PMID:6790564

Comparative analysis of multiple-casualty incident triage algorithms.

PubMed

Garner, A; Lee, A; Harrison, K; Schultz, C H

2001-11-01

We sought to retrospectively measure the accuracy of multiple-casualty incident (MCI) triage algorithms and their component physiologic variables in predicting adult patients with critical injury. We performed a retrospective review of 1,144 consecutive adult patients transported by ambulance and admitted to 2 trauma centers. Association between first-recorded out-of-hospital physiologic variables and a resource-based definition of severe injury appropriate to the MCI context was determined. The association between severe injury and Triage Sieve, Simple Triage and Rapid Treatment, modified Simple Triage and Rapid Treatment, and CareFlight Triage was determined in the patient population. Of the physiologic variables, the Motor Component of the Glasgow Coma Scale had the strongest association with severe injury, followed by systolic blood pressure. The differences between CareFlight Triage, Simple Triage and Rapid Treatment, and modified Simple Triage and Rapid Treatment were not dramatic, with sensitivities of 82% (95% confidence interval [CI] 75% to 88%), 85% (95% CI 78% to 90%), and 84% (95% CI 76% to 89%), respectively, and specificities of 96% (95% CI 94% to 97%), 86% (95% CI 84% to 88%), and 91% (95% CI 89% to 93%), respectively. Both forms of Triage Sieve were significantly poorer predictors of severe injury. Of the physiologic variables used in the triage algorithms, the Motor Component of the Glasgow Coma Scale and systolic blood pressure had the strongest association with severe injury. CareFlight Triage, Simple Triage and Rapid Treatment, and modified Simple Triage and Rapid Treatment had similar sensitivities in predicting critical injury in designated trauma patients, but CareFlight Triage had better specificity. Because patients in a true mass casualty situation may not be completely comparable with designated trauma patients transported to emergency departments in routine circumstances, the best triage instrument in this study may not be the best in an actual MCI. These findings must be validated prospectively before their accuracy can be confirmed.

A new hydroxynaphthyl benzothiazole derived fluorescent probe for highly selective and sensitive Cu2 + detection

NASA Astrophysics Data System (ADS)

Tang, Lijun; He, Ping; Zhong, Keli; Hou, Shuhua; Bian, Yanjiang

2016-12-01

A new reactive probe, 1-(benzo[d]thiazol-2-yl)naphthalen-2-yl-picolinate (BTNP), was designed and synthesized. BTNP acts as a highly selective probe to Cu2 + in DMSO/H2O (7/3, v/v, Tris-HCl 10 mM, pH = 7.4) solution based on Cu2 + catalyzed hydrolysis of the picolinate ester moiety in BTNP, which leads to the formation of an ESIPT active product with dual wavelength emission enhancement. The probe also possesses the advantages of simple synthesis, rapid response and high sensitivity. The pseudo-first-order reaction rate constant was calculated to be 0.205 min- 1. Moreover, application of BTNP to Cu2 + detection in living cells and real water samples was also explored.

Determination of selected azaarenes in water by bonded-phase extraction and liquid chromatography

USGS Publications Warehouse

Steinheimer, T.R.; Ondrus, M.G.

1986-01-01

A method for the rapid and simple quantitative determination of quinoline, isoquinoline, and five selected three-ring azaarenes in water has been developed. The azaarene fraction is separated from its carbon analogues on n-octadecyl packing material by edition with acidified water/acetonitrile. Concentration as great as 1000-fold is achieved readily. Instrumental analysis involves high-speed liquid chromatography on flexible-walled, wide-bore columns with fluorescence and ultraviolet detection at several wavelengths employing filter photometers in series. Method-validation data is provided as azaarene recovery efficiency from fortified samples. Distilled water, river water, contaminated ground water, and secondary-treatment effluent have been tested. Recoveries at part-per-billion levels are nearly quantitative for the three-ring compounds, but they decrease for quinoline and isoquinoline. ?? 1986 American Chemical Society.

Experimental evolution and the dynamics of adaptation and genome evolution in microbial populations.

PubMed

Lenski, Richard E

2017-10-01

Evolution is an on-going process, and it can be studied experimentally in organisms with rapid generations. My team has maintained 12 populations of Escherichia coli in a simple laboratory environment for >25 years and 60 000 generations. We have quantified the dynamics of adaptation by natural selection, seen some of the populations diverge into stably coexisting ecotypes, described changes in the bacteria's mutation rate, observed the new ability to exploit a previously untapped carbon source, characterized the dynamics of genome evolution and used parallel evolution to identify the genetic targets of selection. I discuss what the future might hold for this particular experiment, briefly highlight some other microbial evolution experiments and suggest how the fields of experimental evolution and microbial ecology might intersect going forward.

Highly selective and sensitive detection of Cu2+ with lysine enhancing bovine serum albumin modified-carbon dots fluorescent probe.

PubMed

Liu, Jia-Ming; Lin, Li-ping; Wang, Xin-Xing; Lin, Shao-Qin; Cai, Wen-Lian; Zhang, Li-Hong; Zheng, Zhi-Yong

2012-06-07

Based on the ability of lysine (Lys) to enhance the fluorescence intensity of bovine serum albumin modified-carbon dots (CDs-BSA) to decrease surface defects and quench fluorescence of the CDs-BSA-Lys system in the presence of Cu(2+) under conditions of phosphate buffer (PBS, pH = 5.0) at 45 °C for 10 min, a sensitive Lys enhancing CDs-BSA fluorescent probe was designed. The environment-friendly, simple, rapid, selective and sensitive fluorescent probe has been utilized to detect Cu(2+) in hair and tap water samples and it achieved consistent results with those obtained by inductively coupled plasma mass spectroscopy (ICP-MS). The mechanism of the proposed assay for the detection of Cu(2+) is discussed.

Multifunctional inorganic-organic hybrid nanospheres for rapid and selective luminescence detection of TNT in mixed nitroaromatics via magnetic separation.

PubMed

Ma, Yingxin; Huang, Sheng; Wang, Leyu

2013-11-15

Rapid, sensitive and selective detection of 2,4,6-trinitrotoluene (TNT) in aqueous solution differentiating from other nitroaromatics and independent of complicated instruments is in high demand for public safety and environmental monitoring. Despite of many methods for TNT detection, it is hard to differentiate TNT from 2,4,6-trinitrophenol (TNP) due to their highly similar structures and properties. In this work, via a simple and versatile method, LaF3ːCe(3+)-Tb(3+)and Fe3O4 nanoparticle-codoped multifunctional nanospheres were prepared through self-assembly of the building blocks. The luminescence of these nanocomposites was dramatically quenched via adding nitroaromatics into the aqueous solution. After the magnetic separation, however, the interference of other nitroaromatics including 2,4,6-trinitrophenol (TNP), 2,4-dinitrotoluene (DNT), and nitrobenzene (NB) was effectively overcome due to the removal of these coexisting nitroaromatics from the surface of nanocomposites. Due to the formation of TNT(-)-RCONH3(+), the TNT was attached to the surface of the nanocomposites and was quantitatively detected by the postexposure luminescence quenching. Meanwhile, the luminescence intensity is negatively proportional to the concentration of TNT in the range of 0.01-5.0 μg/mL with the 3σ limit of detection (LOD) of 10.2 ng/mL. Therefore, the as-developed method provides a novel strategy for rapid and selective detection of TNT in the mixture solution of nitroaromatics by postexposure luminescence quenching. Copyright © 2013 Elsevier B.V. All rights reserved.

Rapid polymerase chain reaction-based screening assay for bacterial biothreat agents.

PubMed

Yang, Samuel; Rothman, Richard E; Hardick, Justin; Kuroki, Marcos; Hardick, Andrew; Doshi, Vishal; Ramachandran, Padmini; Gaydos, Charlotte A

2008-04-01

To design and evaluate a rapid polymerase chain reaction (PCR)-based assay for detecting Eubacteria and performing early screening for selected Class A biothreat bacterial pathogens. The authors designed a two-step PCR-based algorithm consisting of an initial broad-based universal detection step, followed by specific pathogen identification targeted for identification of the Class A bacterial biothreat agents. A region in the bacterial 16S rRNA gene containing a highly variable sequence flanked by clusters of conserved sequences was chosen as the target for the PCR assay design. A previously described highly conserved region located within the 16S rRNA amplicon was selected as the universal probe (UniProbe, Integrated DNA Technology, Coralville, IA). Pathogen-specific TaqMan probes were designed for Bacillus anthracis, Yersinia pestis, and Francisella tularensis. Performance of the assay was assessed using genomic DNA extracted from the aforementioned biothreat-related organisms (inactivated or surrogate) and other common bacteria. The UniProbe detected the presence of all tested Eubacteria (31/31) with high analytical sensitivity. The biothreat-specific probes accurately identified organisms down to the closely related species and genus level, but were unable to discriminate between very close surrogates, such as Yersinia philomiragia and Bacillus cereus. A simple, two-step PCR-based assay proved capable of both universal bacterial detection and identification of select Class A bacterial biothreat and biothreat-related pathogens. Although this assay requires confirmatory testing for definitive species identification, the method has great potential for use in ED-based settings for rapid diagnosis in cases of suspected Category A bacterial biothreat agents.

[Microbiology--laboratory examinations for bacterias].

PubMed

Hen, Renjun; Imafuku, Yuji; Yoshida, Hiroshi

2002-11-01

As it has been required to identify pathogenic microbes in shorter times, simple and rapid methods have been developed and used. Here, we summarized the present situation of rapid diagnostic testing in clinical microbiology in Japan, and also presented our results on PBP2' detection. The rapid test kits available in Japan for E. coli, Helicobacter pylori, Salmonella, Streptococcus and Staphylococcus aureus were described. Rapid examination methods are based mainly on immunologic reactions, which included slide agglutination using latex particle, immunochromatography and ELISA. Times required for the identification are 10 to 15 minutes. Moreover, rapid test kits employing PCR are also marketed. Further, we evaluated MRSA-LA "Seiken" which is a rapid detection kit for PBP2' produced by MRSA. The test was shown to be highly sensitive and specific. For the rapid identification of pathogenic microbes, simple and rapid test kits described here will be used more in clinical diagnosis.

Nest construction by a ground-nesting bird represents a potential trade-off between egg crypticity and thermoregulation.

PubMed

Mayer, Paul M; Smith, Levica M; Ford, Robert G; Watterson, Dustin C; McCutchen, Marshall D; Ryan, Mark R

2009-04-01

Predation selects against conspicuous colors in bird eggs and nests, while thermoregulatory constraints select for nest-building behavior that regulates incubation temperatures. We present results that suggest a trade-off between nest crypticity and thermoregulation of eggs based on selection of nest materials by piping plovers (Charadrius melodus), a ground-nesting bird that constructs simple, pebble-lined nests highly vulnerable to predators and exposed to temperature extremes. Piping plovers selected pebbles that were whiter and appeared closer in color to eggs than randomly available pebbles, suggesting a crypsis function. However, nests that were more contrasting in color to surrounding substrates were at greater risk of predation, suggesting an alternate strategy driving selection of white rocks. Near-infrared reflectance of nest pebbles was higher than randomly available pebbles, indicating a direct physical mechanism for heat control through pebble selection. Artificial nests constructed of randomly available pebbles heated more quickly and conferred heat to model eggs, causing eggs to heat more rapidly than in nests constructed from piping plover nest pebbles. Thermal models and field data indicated that temperatures inside nests may remain up to 2-6 degrees C cooler than surrounding substrates. Thermal models indicated that nests heat especially rapidly if not incubated, suggesting that nest construction behavior may serve to keep eggs cooler during the unattended laying period. Thus, pebble selection suggests a potential trade-off between maximizing heat reflectance to improve egg microclimate and minimizing conspicuous contrast of nests with the surrounding substrate to conceal eggs from predators. Nest construction behavior that employs light-colored, thermally reflective materials may represent an evolutionary response by birds and other egg-laying organisms to egg predation and heat stress.

A simple highly sensitive and selective aptamer-based colorimetric sensor for environmental toxins microcystin-LR in water samples.

PubMed

Li, Xiuyan; Cheng, Ruojie; Shi, Huijie; Tang, Bo; Xiao, Hanshuang; Zhao, Guohua

2016-03-05

A simple and highly sensitive aptamer-based colorimetric sensor was developed for selective detection of Microcystin-LR (MC-LR). The aptamer (ABA) was employed as recognition element which could bind MC-LR with high-affinity, while gold nanoparticles (AuNPs) worked as sensing materials whose plasma resonance absorption peaks red shifted upon binding of the targets at a high concentration of sodium chloride. With the addition of MC-LR, the random coil aptamer adsorbed on Au NPs altered into regulated structure to form MC-LR-aptamer complexes and broke away from the surface of Au NPs, leading to the aggregation of AuNPs, and the color converted from red to blue due to the interparticle plasmon coupling. Results showed that our aptamer-based colorimetric sensor exhibited rapid and sensitive detection performance for MC-LR with linear range from 0.5 nM to 7.5 μM and the detection limit reached 0.37 nM. Meanwhile, the pollutants usually coexisting with MC-LR in pollutant water samples had not demonstrated disturbance for detecting of MC-LR. The mechanism was also proposed suggesting that high affinity interaction between aptamer and MC-LR significantly enhanced the sensitivity and selectivity for MC-LR detection. Besides, the established method was utilized in analyzing real water samples and splendid sensitivity and selectivity were obtained as well. Copyright © 2015 Elsevier B.V. All rights reserved.

Entropy and charge in molecular evolution--the case of phosphate

NASA Technical Reports Server (NTRS)

Arrhenius, G.; Sales, B.; Mojzsis, S.; Lee, T.; Bada, J. L. (Principal Investigator)

1997-01-01

Biopoesis, the creation of life, implies molecular evolution from simple components, randomly distributed and in a dilute state, to form highly organized, concentrated systems capable of metabolism, replication and mutation. This chain of events must involve environmental processes that can locally lower entropy in several steps; by specific selection from an indiscriminate mixture, by concentration from dilute solution, and in the case of the mineral-induced processes, by particular effectiveness in ordering and selective reaction, directed toward formation of functional biomolecules. Numerous circumstances provide support for the notion that negatively charged molecules were functionally required and geochemically available for biopoesis. Sulfite ion may have been important in bisulfite complex formation with simple aldehydes, facilitating the initial concentration by sorption of aldehydes in positively charged surface active minerals. Borate ion may have played a similar, albeit less investigated role in forming charged sugar complexes. Among anionic species, oligophosphate ions and charged phosphate esters are likely to have been of even more wide ranging importance, reflected in the continued need for phosphate in a proposed RNA world, and extending its central role to evolved biochemistry. Phosphorylation is shown to result in selective concentration by surface sorption of compounds, otherwise too dilute to support condensation reactions. It provides protection against rapid hydrolysis of sugars and, by selective concentration, induces the oligomerization of aldehydes. As a manifestation of life arisen, phosphate already appears in an organic context in the oldest preserved sedimentary record.

A simple reagent-free spectrophotometric assay for monitoring metronidazole therapy in aquarium water.

PubMed

Webb, D Harry; Marrero, Cynthia; Ellis, Helen; Merriwether, Lea; Dove, Alistair D M

2013-09-01

A reagent-free spectrophotometric assay was developed to measure the concentration of metronidazole (a 5-nitroimidazole) in both freshwater and seawater matrices. This assay is simple, repeatable, sensitive, and precise and is ideal for use when a rapid, selective test to determine metronidazole concentration in aqueous matrices is necessary. The assay was practically tested on a South American fishes display during treatment with metronidazole for an outbreak of the flagellated parasite Spironucleus in a mixed cichlid (family Cichlidae) and tetra (family Characidae) community. The assay clearly illustrated the course of treatment for the system during a real clinical application. The assay is not without limitations, as interferences can occur from other drugs in the matrix with similar absorbance spectra. Nonetheless, this type of assay illustrates the potential for use of native absorbance assays in aqueous matrices for this and other therapeutic compounds.

Selected retinoids: determination by isocratic normal-phase HPLC.

PubMed

Klvanova, J; Brtko, J

2002-09-01

Retinol (ROL), retinal (RAL) and retinoic acid (RA) are physiologically active forms of vitamin A. All-trans retinoic acid (ATRA) can be formed by oxidation from all-trans retinal (ATRAL). Isomerization of RA is considered to be an important metabolic pathway of retinoids. RA isomers transactivate various response pathways via their cognate nuclear receptors that act as ligand inducible transcription factors. The aim of this study was to establish a rapid and simple method for determination of ATRA, 13-cis retinoic acid (13CRA) and ATRAL by HPLC. In our laboratory, we slightly modified the method of Miyagi et al. (2001) and separated ATRA, 13CRA and ATRAL by simple isocratic normal phase HPLC. Both retinoic acid isomers and ATRAL were eluted within 13 min and all components were well resolved. The coefficients of variation (C.V.) for RAs and RAL were from 3.0 to 5.4 %.

Defining microchannels and valves on a hydrophobic paper by low-cost inkjet printing of aqueous or weak organic solutions.

PubMed

Cai, Longfei; Zhong, Minghua; Li, Huolin; Xu, Chunxiu; Yuan, Biyu

2015-07-01

We describe a simple and cost-effective strategy for rapid fabrication of microfluidic paper-based analytical devices and valves by inkjet printing. NaOH aqueous solution was printed onto a hydrophobic filter paper, which was previously obtained by soaking in a trimethoxyoctadecylsilane-heptane solution, allowing selective wet etching of hydrophobic cellulose to create hydrophilic-hydrophobic contrast with a relatively good resolution. Hexadecyltrimethylammonium bromide (CTMAB)-ethanol solution was printed onto hydrophobic paper to fabricate temperature-controlled valves. At low temperature, CTMAB deposited on the paper is insoluble in aqueous fluid, thus the paper remains hydrophobic. At high temperature, CTMAB becomes soluble so the CTMAB-deposited channel becomes hydrophilic, allowing the wicking of aqueous solution through the valve. We believe that this strategy will be very attractive for the development of simple micro analytical devices for point-of-care applications, including diagnostic testing, food safety control, and environmental monitoring.

[Quality assurance of the renal applications software].

PubMed

del Real Núñez, R; Contreras Puertas, P I; Moreno Ortega, E; Mena Bares, L M; Maza Muret, F R; Latre Romero, J M

2007-01-01

The need for quality assurance of all technical aspects of nuclear medicine studies is widely recognised. However, little attention has been paid to the quality assurance of the applications software. Our work reported here aims at verifying the analysis software for processing of renal nuclear medicine studies (renograms). The software tools were used to build a synthetic dynamic model of renal system. The model consists of two phases: perfusion and function. The organs of interest (kidneys, bladder and aortic artery) were simple geometric forms. The uptake of the renal structures was described by mathematic functions. Curves corresponding to normal or pathological conditions were simulated for kidneys, bladder and aortic artery by appropriate selection of parameters. There was no difference between the parameters of the mathematic curves and the quantitative data produced by the renal analysis program. Our test procedure is simple to apply, reliable, reproducible and rapid to verify the renal applications software.

Arkansas Groundwater-Quality Network

USGS Publications Warehouse

Pugh, Aaron L.; Jackson, Barry T.; Miller, Roger

2014-01-01

Arkansas is the fourth largest user of groundwater in the United States, where groundwater accounts for two-thirds of the total water use. Groundwater use in the State increased by 510 percent between 1965 and 2005 (Holland, 2007). The Arkansas Groundwater-Quality Network is a Web map interface (http://ar.water.usgs.gov/wqx) that provides rapid access to the U.S. Geological Survey’s (USGS) National Water Information System (NWIS) and the U.S. Environmental Protection Agency’s (USEPA) STOrage and RETrieval (STORET) databases of ambient water information. The interface enables users to perform simple graphical analysis and download selected water-quality data.

[Flotation and extraction spectrophotometric determination of trace silicate in water].

PubMed

Di, J; Liu, Q; Li, W

2000-12-01

In HCl solution, silicate reacted with molybdate ammonium to produce silicomolibdic, then a yellow compound which was produced from the oxidation of TMB was simultaneously isolated to benzene phase by flotation and then isolated to dimethylsulfoxideformic acid by extraction. The compound gives a high absorption at 458 nm. The apparent molar absorptivity is 1.26 x 10(5) L.mol-1.cm-1. In the range of 0.02-1 mg.L-1 Si obeys Beer's law. The proposed method which combines with enrichment and measurement is simple, rapid, selective and convenient to determine silicate in water with satisfied results.

Extending cluster Lot Quality Assurance Sampling designs for surveillance programs

PubMed Central

Hund, Lauren; Pagano, Marcello

2014-01-01

Lot quality assurance sampling (LQAS) has a long history of applications in industrial quality control. LQAS is frequently used for rapid surveillance in global health settings, with areas classified as poor or acceptable performance based on the binary classification of an indicator. Historically, LQAS surveys have relied on simple random samples from the population; however, implementing two-stage cluster designs for surveillance sampling is often more cost-effective than simple random sampling. By applying survey sampling results to the binary classification procedure, we develop a simple and flexible non-parametric procedure to incorporate clustering effects into the LQAS sample design to appropriately inflate the sample size, accommodating finite numbers of clusters in the population when relevant. We use this framework to then discuss principled selection of survey design parameters in longitudinal surveillance programs. We apply this framework to design surveys to detect rises in malnutrition prevalence in nutrition surveillance programs in Kenya and South Sudan, accounting for clustering within villages. By combining historical information with data from previous surveys, we design surveys to detect spikes in the childhood malnutrition rate. PMID:24633656

Extending cluster lot quality assurance sampling designs for surveillance programs.

PubMed

Hund, Lauren; Pagano, Marcello

2014-07-20

Lot quality assurance sampling (LQAS) has a long history of applications in industrial quality control. LQAS is frequently used for rapid surveillance in global health settings, with areas classified as poor or acceptable performance on the basis of the binary classification of an indicator. Historically, LQAS surveys have relied on simple random samples from the population; however, implementing two-stage cluster designs for surveillance sampling is often more cost-effective than simple random sampling. By applying survey sampling results to the binary classification procedure, we develop a simple and flexible nonparametric procedure to incorporate clustering effects into the LQAS sample design to appropriately inflate the sample size, accommodating finite numbers of clusters in the population when relevant. We use this framework to then discuss principled selection of survey design parameters in longitudinal surveillance programs. We apply this framework to design surveys to detect rises in malnutrition prevalence in nutrition surveillance programs in Kenya and South Sudan, accounting for clustering within villages. By combining historical information with data from previous surveys, we design surveys to detect spikes in the childhood malnutrition rate. Copyright © 2014 John Wiley & Sons, Ltd.

Coins and Costs: A Simple and Rapid Assessment of Basic Financial Knowledge

ERIC Educational Resources Information Center

Willner, Paul; Bailey, Rebecca; Dymond, Simon; Parry, Rhonwen

2011-01-01

Introduction: We describe a simple and rapid screening test for basic financial knowledge that is suitable for administration to people with mild intellectual disabilities. Method: The Coins and Costs test asks respondents to name coins, and to estimate prices of objects ranging between 1 British Pound (an ice cream) and 100K British Pounds (a…

A SIMPLE AND RAPID MATRIX-ASSISTED LASER DESORPTION/IONIZATION TIME OF FLIGHT MASS SPECTROMETRY METHOD TO SCREEN FISH PLASMA SAMPLES FOR ESTROGEN-RESPONSIVE BIOMARKERS

EPA Science Inventory

In this study, we describe and evaluate the performance of a simple and rapid mass spectral method for screening fish plasma for estrogen-responsive biomarkers using matrix assisted laster desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) couopled with a short...

Evaluation of Flow-Injection Tandem Mass Spectrometry for Rapid and High-Throughput Quantitative Determination of B-Vitamins in Nutritional Supplements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bhandari, Deepak; Van Berkel, Gary J

2012-01-01

The use of flow-injection electrospray ionization tandem mass spectrometry for rapid and high-throughput mass spectral analysis of selected B-vitamins, viz. B1, B2, B3, B5, and B6, in nutritional formulations was demonstrated. A simple and rapid (~5 min) in-tube sample preparation was performed by adding extraction solvent to a powdered sample aliquot followed by agitation, centrifugation, and filtration to recover an extract for analysis. Automated flow injection introduced 1 L of the extracts directly into the mass spectrometer ion source without chromatographic separation. Sample-to-sample analysis time was 60 s representing significant improvement over conventional liquid chromatography approaches which typically require 25-45more » min, and often require more significant sample preparation procedures. Quantitative capabilities of the flow-injection analysis were tested using the method of standard additions and NIST standard reference material (SRM 3280) multivitamin/multielement tablets. The quantity determined for each B-vitamin in SRM 3280 was within the statistical range provided for the respective certified values. The same sample preparation and analysis approach was also applied to two different commercial vitamin supplement tablets and proved to be successful in the quantification of the selected B-vitamins as evidenced by an agreement with the labels values and the results obtained using isotope dilution liquid chromatography/mass spectrometry.« less

A simple bias correction in linear regression for quantitative trait association under two-tail extreme selection.

PubMed

Kwan, Johnny S H; Kung, Annie W C; Sham, Pak C

2011-09-01

Selective genotyping can increase power in quantitative trait association. One example of selective genotyping is two-tail extreme selection, but simple linear regression analysis gives a biased genetic effect estimate. Here, we present a simple correction for the bias.

Validated HPLC-UV method for determination of naproxen in human plasma with proven selectivity against ibuprofen and paracetamol.

PubMed

Filist, Monika; Szlaska, Iwona; Kaza, Michał; Pawiński, Tomasz

2016-06-01

Estimating the influence of interfering compounds present in the biological matrix on the determination of an analyte is one of the most important tasks during bioanalytical method development and validation. Interferences from endogenous components and, if necessary, from major metabolites as well as possible co-administered medications should be evaluated during a selectivity test. This paper describes a simple, rapid and cost-effective HPLC-UV method for the determination of naproxen in human plasma in the presence of two other analgesics, ibuprofen and paracetamol. Sample preparation is based on a simple liquid-liquid extraction procedure with a short, 5 s mixing time. Fenoprofen, which is characterized by a similar structure and properties to naproxen, was first used as the internal standard. The calibration curve is linear in the concentration range of 0.5-80.0 µg/mL, which is suitable for pharmacokinetic studies following a single 220 mg oral dose of naproxen sodium. The method was fully validated according to international guidelines and was successfully applied in a bioequivalence study in humans. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

A visual assay and spectrophotometric determination of LLM-105 explosive using detection of gold nanoparticle aggregation at two pH values.

PubMed

He, Yi; Cheng, Yang

2016-08-01

We report a simple, rapid, and sensitive assay for visual and spectrophotometric detection of the 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105) explosive. The assay is based on different interactions between LLM-105 and gold nanoparticle (AuNP) dispersions at two pH values, leading to the formation of dispersed or aggregated AuNPs. Two AuNP dispersions at two pH values were applied to recognize and detect LLM-105 instead of traditional AuNP dispersion under an aptotic pH to improve the anti-interference ability. The developed assay showed excellent sensitivity with a detection limit of 3 ng/mL, and the presence of as low as 0.2 μg/mL LLM-105 can be directly detected with the bare eye. This sensitivity is about six orders of magnitude higher than that of the reported traditional assays. Additionally, the assay exhibited good selectivity toward LLM-105 over other explosives, sulfur-containing compounds, and amines. Graphical abstract A simple, sensitive, and selective assay for LLM-105 was developed based on the pH-dependent interaction between the LLM-105 explosive and gold nanoparticle dispersion.

Rapid Detection of Haptoglobin Gene Deletion in Alkaline-Denatured Blood by Loop-Mediated Isothermal Amplification Reaction

PubMed Central

Soejima, Mikiko; Egashira, Kouichi; Kawano, Hiroyuki; Kawaguchi, Atsushi; Sagawa, Kimitaka; Koda, Yoshiro

2011-01-01

Anhaptoglobinemic patients run the risk of severe anaphylactic transfusion reaction because they produce serum haptoglobin antibodies. Being homozygous for the haptoglobin gene deletion allele (HPdel) is the only known cause of congenital anhaptoglobinemia, and detection of HPdel before transfusion is important to prevent anaphylactic shock. In this study, we developed a loop-mediated isothermal amplification (LAMP)-based screening for HPdel. Optimal primer sets and temperature for LAMP were selected for HPdel and the 5′ region of the HP using genomic DNA as a template. Then, the effects of diluent and boiling on LAMP amplification were examined using whole blood as a template. Blood samples diluted 1:100 with 50 mmol/L NaOH without boiling gave optimal results as well as those diluted 1:2 with water followed by boiling. The results from 100 blood samples were fully concordant with those obtained by real-time PCR methods. Detection of the HPdel allele by LAMP using alkaline-denatured blood samples is rapid, simple, accurate, and cost effective, and is readily applicable in various clinical settings because this method requires only basic instruments. In addition, the simple preparation of blood samples using NaOH saves time and effort for various genetic tests. PMID:21497293

Application of a rapid and selective method for the simultaneous determination of carebastine and pseudoephedrine in human plasma by liquid chromatography-electrospray mass spectrometry for bioequivalence study in Korean subjects.

PubMed

Lee, Myung-Jae; Lee, Heon-Woo; Kang, Jong-Min; Seo, Ji-Hyung; Tak, Seong-Kun; Shim, Wangseob; Yim, Sung-Vin; Hong, Seung Jae; Lee, Kyung-Tae

2010-10-01

We describe a simple, rapid and sensitive high-performance liquid chromatography-electrospray ionization tandem mass spectrometric method that was developed for the simultaneous determination of carebastine and pseudoephedrine in human plasma using cisapride as an internal standard. Acquisition was performed in multiple-reaction monitoring mode by monitoring the transitions: m/z 500.43 > 167.09 for carebastine and m/z 166.04 > 147.88 for pseudoephedrine. The devised method involves a simple single-step liquid-liquid extraction with ethyl acetate. Chromatographic separation was performed on a C(18) reversed-phase chromatographic column at 0.2  mL/min by isocratic elution with 10  mM ammonium formate buffer-acetonitrile (30:70, v/v; adjusted to pH 3.3 with formic acid). The devised method was validated over 0.5-100  ng/mL of carebastine and 5-1000  ng/mL of pseudoephedrine with acceptable accuracy and precision, and was successfully applied to a bioequivalence study involving a single oral dose (10  mg of ebastine plus 120  mg of pseudoephedrine complex) to healthy Korean volunteers. Copyright © 2010 John Wiley & Sons, Ltd.

Simultaneous dispersive liquid-liquid microextraction derivatisation and gas chromatography mass spectrometry analysis of subcritical water extracts of sweet and sour cherry stems.

PubMed

Švarc-Gajić, Jaroslava; Clavijo, Sabrina; Suárez, Ruth; Cvetanović, Aleksandra; Cerdà, Víctor

2018-03-01

Cherry stems have been used in traditional medicine mostly for the treatment of urinary tract infections. Extraction with subcritical water, according to its selectivity, efficiency and other aspects, differs substantially from conventional extraction techniques. The complexity of plant subcritical water extracts is due to the ability of subcritical water to extract different chemical classes of different physico-chemical properties and polarities in a single run. In this paper, dispersive liquid-liquid microextraction (DLLME) with simultaneous derivatisation was optimised for the analysis of complex subcritical water extracts of cherry stems to allow simple and rapid preparation prior to gas chromatography-mass spectrometry (GC-MS). After defining optimal extracting and dispersive solvents, the optimised method was used for the identification of compounds belonging to different chemical classes in a single analytical run. The developed sample preparation protocol enabled simultaneous extraction and derivatisation, as well as convenient coupling with GC-MS analysis, reducing the analysis time and number of steps. The applied analytical protocol allowed simple and rapid chemical screening of subcritical water extracts and was used for the comparison of subcritical water extracts of sweet and sour cherry stems. Graphical abstract DLLME GC MS analysis of cherry stem extracts obtained by subcritical water.

A Simple and Selective Spectrophotometric Method for the Determination of Trace Gold in Real, Environmental, Biological, Geological and Soil Samples Using Bis (Salicylaldehyde) Orthophenylenediamine

PubMed Central

Soomro, Rubina; Ahmed, M. Jamaluddin; Memon, Najma; Khan, Humaira

2008-01-01

A simple high sensitive, selective, and rapid spectrophotometric method for the determination of trace gold based on the rapid reaction of gold(III) with bis(salicylaldehyde)orthophenylenediamine (BSOPD) in aqueous and micellar media has been developed. BSOPD reacts with gold(III) in slightly acidic solution to form a 1:1 brownish-yellow complex, which has an maximum absorption peak at 490 nm in both aqueous and micellar media. The most remarkable point of this method is that the molar absorptivities of the gold-BSOPD complex form in the presence of the nonionic TritonX-100 surfactant are almost a 10 times higher than the value observed in the aqueous solution, resulting in an increase in the sensitivity and selectivity of the method. The apparent molar absorptivities were found to be 2.3 × 104 L mol−1 cm−1 and 2.5 × 105 L mol−1 cm−1 in aqueous and micellar media, respectively. The reaction is instantaneous and the maximum absorbance was obtained after 10 min at 490 nm and remains constant for over 24 h at room temperature. The linear calibration graphs were obtained for 0.1–30 mg L−1 and 0.01–30 mg L−1 of gold(III) in aqueous and surfactant media, respectively. The interference from over 50 cations, anions and complexing agents has been studied at 1 mg L−1 of Au(III); most metal ions can be tolerated in considerable amounts in aqueous micellar solutions. The Sandell’s sensitivity, the limit of detection and relative standard deviation (n = 9) were found to be 5 ng cm−2, 1 ng mL−1 and 2%, respectively in aqueous micellar solutions. Its sensitivity and selectivity are remarkably higher than that of other reagents in the literature. The proposed method was successfully used in the determination of gold in several standard reference materials (alloys and steels), environmental water samples (potable and polluted), and biological samples (blood and urine), geological, soil and complex synthetic mixtures. The results obtained agree well with those samples analyzed by atomic absorption spectrophotometry (AAS). PMID:19609392

Bayesian feature selection for high-dimensional linear regression via the Ising approximation with applications to genomics.

PubMed

Fisher, Charles K; Mehta, Pankaj

2015-06-01

Feature selection, identifying a subset of variables that are relevant for predicting a response, is an important and challenging component of many methods in statistics and machine learning. Feature selection is especially difficult and computationally intensive when the number of variables approaches or exceeds the number of samples, as is often the case for many genomic datasets. Here, we introduce a new approach--the Bayesian Ising Approximation (BIA)-to rapidly calculate posterior probabilities for feature relevance in L2 penalized linear regression. In the regime where the regression problem is strongly regularized by the prior, we show that computing the marginal posterior probabilities for features is equivalent to computing the magnetizations of an Ising model with weak couplings. Using a mean field approximation, we show it is possible to rapidly compute the feature selection path described by the posterior probabilities as a function of the L2 penalty. We present simulations and analytical results illustrating the accuracy of the BIA on some simple regression problems. Finally, we demonstrate the applicability of the BIA to high-dimensional regression by analyzing a gene expression dataset with nearly 30 000 features. These results also highlight the impact of correlations between features on Bayesian feature selection. An implementation of the BIA in C++, along with data for reproducing our gene expression analyses, are freely available at http://physics.bu.edu/∼pankajm/BIACode. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Rapid differentiation of refined fuels using negative electrospray ionization/mass spectrometry

USGS Publications Warehouse

Rostad, C.E.; Hostettler, F.D.

2005-01-01

Negative electrospray ionization/MS enabled rapid, specific, and selective screening for unique polar components at parts per million concentrations in commercial hydrocarbon products without extensive sample preparation, separation, chromatography, or quantitation. Commercial fuel types were analyzed with this method, including kerosene, jet fuel, white gas, charcoal lighter fluid, on-road and off-road diesel fuels, and various grades and brands of gasolines. The different types of fuels produced unique and relatively simple spectra. These analyses were then applied to hydrocarbon samples from a large, long-term fuel spill. Although the alkane, isoprenoid, and alkylcyclohexane portions began to biodegrade or weather, the polar components in these samples remained relatively unchanged. The type of fuel involved was readily identified by negative electrospray ionization/MS. This is an abstract of a paper presented at the 230th ACS National Meeting (Washington, DC 8/28/2005-9/1/2005).

Isolation of human simple repeat loci by hybridization selection.

PubMed

Armour, J A; Neumann, R; Gobert, S; Jeffreys, A J

1994-04-01

We have isolated short tandem repeat arrays from the human genome, using a rapid method involving filter hybridization to enrich for tri- or tetranucleotide tandem repeats. About 30% of clones from the enriched library cross-hybridize with probes containing trimeric or tetrameric tandem arrays, facilitating the rapid isolation of large numbers of clones. In an initial analysis of 54 clones, 46 different tandem arrays were identified. Analysis of these tandem repeat loci by PCR showed that 24 were polymorphic in length; substantially higher levels of polymorphism were displayed by the tetrameric repeat loci isolated than by the trimeric repeats. Primary mapping of these loci by linkage analysis showed that they derive from 17 chromosomes, including the X chromosome. We anticipate the use of this strategy for the efficient isolation of tandem repeats from other sources of genomic DNA, including DNA from flow-sorted chromosomes, and from other species.

[Flow injection biamperometric analysis of isoniazid].

PubMed

Zhang, J C; Zhao, C; Song, J F

2001-09-01

To establish a simple, rapid, and accurate electrochemical method for on-line determination of isoniazid. Based on the flow injection biamperometry for irreversible couple system, and using two preanodized platinum electrodes with the applied potential difference of 0 V, the biamperometric method for the determination of isoniazid has been proposed by coupling the catalytic oxidation of isoniazid and the reduction of platinum oxide. Common excipients, inorganic ions, amino acids, vitamins and proteins do not interfere with the determination. Linear relationship between current and the concentration of isoniazid is obtained in the range of 1.0 x 10(-6)-1.0 x 10(-4) mol.L-1 (gamma = 0.998, n = 11). The RSD of 1.8% was obtained for 8 successive determinations of 1.0 x 10(-5) mol.L-1 isoniazid. The proposed method has been shown to be sensitive, selective, rapid (120 samples.h-1), and suitable for the on-line direct determination of isoniazid.

Density-Independent Mortality and Increasing Plant Diversity Are Associated with Differentiation of Taraxacum officinale into r- and K-Strategists

PubMed Central

Lipowsky, Annett; Roscher, Christiane; Schumacher, Jens; Schmid, Bernhard

2012-01-01

Background Differential selection between clones of apomictic species may result in ecological differentiation without mutation and recombination, thus offering a simple system to study adaptation and life-history evolution in plants. Methodology/Principal Findings We caused density-independent mortality by weeding to colonizer populations of the largely apomictic Taraxacum officinale (Asteraceae) over a 5-year period in a grassland biodiversity experiment (Jena Experiment). We compared the offspring of colonizer populations with resident populations deliberately sown into similar communities. Plants raised from cuttings and seeds of colonizer and resident populations were grown under uniform conditions. Offspring from colonizer populations had higher reproductive output, which was in general agreement with predictions of r-selection theory. Offspring from resident populations had higher root and leaf biomass, fewer flower heads and higher individual seed mass as predicted under K-selection. Plants grown from cuttings and seeds differed to some degree in the strength, but not in the direction, of their response to the r- vs. K-selection regime. More diverse communities appeared to exert stronger K-selection on resident populations in plants grown from cuttings, while we did not find significant effects of increasing species richness on plants grown from seeds. Conclusions/Significance Differentiation into r- and K-strategists suggests that clones with characteristics of r-strategists were selected in regularly weeded plots through rapid colonization, while increasing plant diversity favoured the selection of clones with characteristics of K-strategists in resident populations. Our results show that different selection pressures may result in a rapid genetic differentiation within a largely apomictic species. Even under the assumption that colonizer and resident populations, respectively, happened to be r- vs. K-selected already at the start of the experiment, our results still indicate that the association of these strategies with the corresponding selection regimes was maintained during the 5-year experimental period. PMID:22253688

Density-independent mortality and increasing plant diversity are associated with differentiation of Taraxacum officinale into r- and K-strategists.

PubMed

Lipowsky, Annett; Roscher, Christiane; Schumacher, Jens; Schmid, Bernhard

2012-01-01

Differential selection between clones of apomictic species may result in ecological differentiation without mutation and recombination, thus offering a simple system to study adaptation and life-history evolution in plants. We caused density-independent mortality by weeding to colonizer populations of the largely apomictic Taraxacum officinale (Asteraceae) over a 5-year period in a grassland biodiversity experiment (Jena Experiment). We compared the offspring of colonizer populations with resident populations deliberately sown into similar communities. Plants raised from cuttings and seeds of colonizer and resident populations were grown under uniform conditions. Offspring from colonizer populations had higher reproductive output, which was in general agreement with predictions of r-selection theory. Offspring from resident populations had higher root and leaf biomass, fewer flower heads and higher individual seed mass as predicted under K-selection. Plants grown from cuttings and seeds differed to some degree in the strength, but not in the direction, of their response to the r- vs. K-selection regime. More diverse communities appeared to exert stronger K-selection on resident populations in plants grown from cuttings, while we did not find significant effects of increasing species richness on plants grown from seeds. Differentiation into r- and K-strategists suggests that clones with characteristics of r-strategists were selected in regularly weeded plots through rapid colonization, while increasing plant diversity favoured the selection of clones with characteristics of K-strategists in resident populations. Our results show that different selection pressures may result in a rapid genetic differentiation within a largely apomictic species. Even under the assumption that colonizer and resident populations, respectively, happened to be r- vs. K-selected already at the start of the experiment, our results still indicate that the association of these strategies with the corresponding selection regimes was maintained during the 5-year experimental period.

A SIMPLE AND RAPID METHOD FOR THE SIMULTANEOUS DETERMINATION OF CALCIUM AND MAGNESIUM FROM THE SAME SAMPLE OF BLOOD SERUM

PubMed Central

Kovács, G. S.; Tárnoky, K. E.

1960-01-01

A simple and rapid procedure has been developed for the complexometric titration of serum calcium and magnesium using “plasmocorinth B” as indicator. Both determinations can be carried out from the same 0.5 ml. sample. The method is in good agreement with the established calcium and magnesium methods. PMID:14411396

Aspergillus tubingensis and Aspergillus niger as the dominant black Aspergillus, use of simple PCR-RFLP for preliminary differentiation.

PubMed

Mirhendi, H; Zarei, F; Motamedi, M; Nouripour-Sisakht, S

2016-03-01

This work aimed to identify the species distribution of common clinical and environmental isolates of black Aspergilli based on simple restriction fragment length polymorphism (RFLP) analysis of the β-tubulin gene. A total of 149 clinical and environmental strains of black Aspergilli were collected and subjected to preliminary morphological examination. Total genomic DNAs were extracted, and PCR was performed to amplify part of the β-tubulin gene. At first, 52 randomly selected samples were species-delineated by sequence analysis. In order to distinguish the most common species, PCR amplicons of 117 black Aspergillus strains were identified by simple PCR-RFLP analysis using the enzyme TasI. Among 52 sequenced isolates, 28 were Aspergillus tubingensis, 21 Aspergillus niger, and the three remaining isolates included Aspergillus uvarum, Aspergillus awamori, and Aspergillus acidus. All 100 environmental and 17 BAL samples subjected to TasI-RFLP analysis of the β-tubulin gene, fell into two groups, consisting of about 59% (n=69) A. tubingensis and 41% (n=48) A. niger. Therefore, the method successfully and rapidly distinguished A. tubingensis and A. niger as the most common species among the clinical and environmental isolates. Although tardy, the Ehrlich test was also able to differentiate A. tubingensis and A. niger according to the yellow color reaction specific to A. niger. A. tubingensis and A. niger are the most common black Aspergillus in both clinical and environmental isolates in Iran. PCR-RFLP using TasI digestion of β-tubulin DNA enables rapid screening for these common species. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Development and validation of a rapid and simple LC-MS/MS method for quantification of vemurafenib in human plasma: application to a human pharmacokinetic study.

PubMed

Bihan, Kevin; Sauzay, Chloé; Goldwirt, Lauriane; Charbonnier-Beaupel, Fanny; Hulot, Jean-Sebastien; Funck-Brentano, Christian; Zahr, Noël

2015-02-01

Vemurafenib (Zelboraf) is a new tyrosine kinase inhibitor that selectively targets activated BRAF V600E gene and is indicated for the treatment of advanced BRAF mutation-positive melanoma. We developed a simple method for vemurafenib quantification using liquid chromatography-tandem mass spectrometry. A stability study of vemurafenib in human plasma was also performed. (13)C(6)-vemurafenib was used as the internal standard. A single-step protein precipitation was used for plasma sample preparation. Chromatography was performed on an Acquity UPLC system (Waters) with chromatographic separation by the use of an Acquity UPLC BEH C18 column (2.1 × 50 mm, 1.7-mm particle size; Waters). Quantification was performed using the monitoring of multiple reactions of following transitions: m/z 488.2 → 381.0 for vemurafenib and m/z 494.2 → 387.0 for internal standard. This method was linear over the range from 1.0 to 100.0 mcg/mL. The lower limit of quantification was 0.1 mcg/mL for vemurafenib in plasma. Vemurafenib remained stable for 1 month at all levels tested, when stored indifferently at room temperature (20 °C), at +4 °C, or at -20 °C. This method was used successfully to perform a plasma pharmacokinetic study of vemurafenib in a patient after oral administration at a steady state. This liquid chromatography-tandem mass spectrometry method for vemurafenib quantification in human plasma is simple, rapid, specific, sensitive, accurate, precise, and reliable.

Design of label-free, homogeneous biosensing platform based on plasmonic coupling and surface-enhanced Raman scattering using unmodified gold nanoparticles.

PubMed

Yi, Zi; Li, Xiao-Yan; Liu, Feng-Juan; Jin, Pei-Yan; Chu, Xia; Yu, Ru-Qin

2013-05-15

Surface-enhanced Raman scattering (SERS) has emerged as a promising spectroscopic technique for biosensing. However, to design a SERS-based biosensor, almost all currently used methods involve the time-consuming and complicated modification of the metallic nanoparticles with the Raman active dye and biorecognition element, which restricts their widespread applications. Herein, we report a label-free, homogeneous and easy-to-operate biosensing platform for the rapid, simple and sensitive SERS detection by using the unmodified gold nanoparticles (Au NPs). This strategy utilizes the difference in adsorption property of single-stranded DNA (ssDNA) and double-stranded DNA (dsDNA) on citrate-coated Au NPs. In the presence of dsDNA, the aggregation of Au NPs takes place after adding salt solution because the dsDNA cannot adsorb on the Au NPs to protect them from salt-induced aggregation. Such aggregation gives rise to the plasmonic coupling of adjacent metallic NPs and turns on the enhancement of the Raman scattering, displaying a strong SERS signal. In contrast, the ssDNA can adsorb on the Au NPs surface through strong electrostatic attraction and protect them from salt-induced aggregation, showing a weak SERS signal. This approach is not only straightforward and simple in design but also rapid and convenient in operation. The feasibility and universality of the design have been demonstrated successfully by the detection of DNA and Hg(2+), and the assay possesses the superior signal-to-background ratio as high as ∼30 and excellent selectivity. The method can be extended to detect various analytes, such as other metal ions, proteins and small molecules by using the oligonucleotides that can selectively bind the analytes. Copyright © 2012 Elsevier B.V. All rights reserved.

Selective derivatization and sequestration of ribose from a prebiotic mix.

PubMed

Springsteen, Greg; Joyce, Gerald F

2004-08-11

Observations regarding the catalytic potential of RNA and the role of RNA in biology have formed the basis for the "RNA world" hypothesis, which suggests that a genetic system based on self-replicating polyribonucleotides preceded modern biology. However, attempts to devise a realistic prebiotic synthesis of nucleic acids from simple starting materials have been plagued by problems of poor chemical selectivity, lack of stereo- and regiospecificity, and similar rates of formation and degradation of some of the key intermediates. For example, ribose would have been only a small component of a highly complex mix of sugars resulting from the condensation of formaldehyde in a prebiotic world. In addition, ribose is more reactive and degrades more rapidly compared with most other monosaccharides. This study demonstrates an approach for the preferential sequestration of ribose relative to other sugars that takes advantage of its greater reactivity. Cyanamide reacts especially rapidly with ribose to form a stable bicyclic adduct. This product crystallizes spontaneously in aqueous solution, whereas the corresponding products derived from threose, galactose, glucose, mannose, and each of the other pentoses do not. Furthermore, when employing a racemic mixture of d- and l-ribose, enantiomerically twinned crystals are formed that contain discrete homochiral domains.

Rapid and selective determination of multi-sulfonamides by high-performance thin layer chromatography coupled to fluorescent densitometry and electrospray ionization mass detection.

PubMed

Chen, Yisheng; Schwack, Wolfgang

2014-02-28

In the European Union (EU), sulfonamides are among the most widely administrated groups of antibiotics in animal husbandry. Therefore, monitoring their residues in edible animal tissues plays an important role in the EU food safety framework. In this work, a simple and efficient method for the rapid screening of twelve prior sulfonamides frequently prescribed as veterinary drugs by high-performance thin-layer chromatography (HPTLC) was established. Sample extracts obtained with acetonitrile were tenfold concentrated and applied to HPTLC without any further cleanup. Following separation and fluram derivatization, sensitive and selective quantitation of the analytes can readily be accomplished with fluorescent densitometry. Limits of detection and quantitation were 15-40 and 35-70μg/kg, respectively. Additionally, a confirmative detection by HPTLC-electrospray ionization mass spectrometry (HPTLC-ESI/MS) was optimized, offering straightforward identification of target zones. Therefore, the risk of potential false positive findings can efficiently be reduced. The method was validated to meet the enforced commission regulation (EU) No. 37/2010, regarding different matrix complexities (bovine milk, porcine liver and kidney). Copyright © 2014 Elsevier B.V. All rights reserved.

Ultrasonication followed by single-drop microextraction combined with GC/MS for rapid determination of organochlorine pesticides from fish.

PubMed

Shrivas, Kamlesh; Wu, Hui-Fen

2008-02-01

A novel, rapid and simple sample pretreatment technique termed ultrasonication followed by single-drop micro-extraction (U-SDME) has been developed and combined with GC/MS for the determination of organochlorine pesticides (OCPs) in fish. In the present work, the lengthy procedures generally used in the conventional methods like, Soxhlet extraction, supercritical fluid extraction, pressurized liquid extraction and microwave assisted solvent extraction for extraction of OCPs from fish tissues are minimized by the use of two simple extraction procedures. Firstly, OCPs from fish were extracted in organic solvent with ultrasonication and then subsequently preconcentrated by single-drop micro-extraction (SDME). Extraction parameters of ultrasonication and SDME were optimized in spiked sample solution in order to obtain efficient extraction of OCPs from fish tissues. The calibration curves for OCPs were found to be linear between 10-1000 ng/g with correlation of estimations in the range 0.990-0.994. The recoveries obtained in blank fish tissues were ranged from 82.1 to 95.3%. The LOD and RSD for determination of OCPs in fish were 0.5 ng/g and 9.4-10.0%, respectively. The proposed method was applied for the determination of bioconcentration factor in fish after exposure to different concentrations of OCPs in cultured water. The present method avoids the co-extraction of lipids, long extraction steps (>12 h) and large amount of organic solvent for the separation of OCPs. The main advantages of the present method are rapid, selective, sensitive and low cost for the determination of OCPs in fish.

Automatic and rapid identification of glycopeptides by nano-UPLC-LTQ-FT-MS and proteomic search engine.

PubMed

Giménez, Estela; Gay, Marina; Vilaseca, Marta

2017-01-30

Here we demonstrate the potential of nano-UPLC-LTQ-FT-MS and the Byonic™ proteomic search engine for the separation, detection, and identification of N- and O-glycopeptide glycoforms in standard glycoproteins. The use of a BEH C18 nanoACQUITY column allowed the separation of the glycopeptides present in the glycoprotein digest and a baseline-resolution of the glycoforms of the same glycopeptide on the basis of the number of sialic acids. Moreover, we evaluated several acquisition strategies in order to improve the detection and characterization of glycopeptide glycoforms with the maximum number of identification percentages. The proposed strategy is simple to set up with the technology platforms commonly used in proteomic labs. The method allows the straightforward and rapid obtention of a general glycosylated map of a given protein, including glycosites and their corresponding glycosylated structures. The MS strategy selected in this work, based on a gas phase fractionation approach, led to 136 unique peptides from four standard proteins, which represented 78% of the total number of peptides identified. Moreover, the method does not require an extra glycopeptide enrichment step, thus preventing the bias that this step could cause towards certain glycopeptide species. Data are available via ProteomeXchange with identifier PXD003578. We propose a simple and high-throughput glycoproteomics-based methodology that allows the separation of glycopeptide glycoforms on the basis of the number of sialic acids, and their automatic and rapid identification without prior knowledge of protein glycosites or type and structure of the glycans. Copyright © 2016 Elsevier B.V. All rights reserved.

Detection of cerebrospinal fluid leakage by specific measurement of transferrin glycoforms.

PubMed

Kwon, Seok-Joon; Zhang, Fuming; Dordick, Jonathan S; Sonstein, William J; Linhardt, Robert J

2015-10-01

A simple and rapid detection of cerebrospinal fluid (CSF) leakage would benefit spine surgeons making critical postoperative decisions on patient care. We have assessed novel approaches to selectively determine CSF β2-transferrin (β2TF), an asialo-transferrin (aTF) biomarker, without interference from serum sialo-transferrin (sTF) in test samples. First, we performed mild periodate oxidation to selectively generate aldehyde groups in sTF for capture with magnetic hydrazide microparticles, and selective removal with a magnetic separator. Using this protocol sTF was selectively removed from mixtures of CSF and serum containing CSF aTF (β2TF) and serum sTF, respectively. Second, a two-step enzymatic method was developed with neuraminidase and galactose oxidase for generating aldehyde groups in sTF present in CSF and serum mixtures for magnetic hydrazide microparticle capture. After selectively removing sTF from mixtures of CSF and serum, ELISA could detect significant TF signal only in CSF, while the TF signal in serum was negligible. The new approach for selective removal of only sTF in test samples will be promising for the required intervention by a spine surgeon. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Enzyme-modified carbon-fiber microelectrode for the quantification of dynamic fluctuations of nonelectroactive analytes using fast-scan cyclic voltammetry.

PubMed

Lugo-Morales, Leyda Z; Loziuk, Philip L; Corder, Amanda K; Toups, J Vincent; Roberts, James G; McCaffrey, Katherine A; Sombers, Leslie A

2013-09-17

Neurotransmission occurs on a millisecond time scale, but conventional methods for monitoring nonelectroactive neurochemicals are limited by slow sampling rates. Despite a significant global market, a sensor capable of measuring the dynamics of rapidly fluctuating, nonelectroactive molecules at a single recording site with high sensitivity, electrochemical selectivity, and a subsecond response time is still lacking. To address this need, we have enabled the real-time detection of dynamic glucose fluctuations in live brain tissue using background-subtracted, fast-scan cyclic voltammetry. The novel microbiosensor consists of a simple carbon fiber surface modified with an electrodeposited chitosan hydrogel encapsulating glucose oxidase. The selectivity afforded by voltammetry enables quantitative and qualitative measurements of enzymatically generated H2O2 without the need for additional strategies to eliminate interfering agents. The microbiosensors possess a sensitivity and limit of detection for glucose of 19.4 ± 0.2 nA mM(-1) and 13.1 ± 0.7 μM, respectively. They are stable, even under deviations from physiological normoxic conditions, and show minimal interference from endogenous electroactive substances. Using this approach, we have quantitatively and selectively monitored pharmacologically evoked glucose fluctuations with unprecedented chemical and spatial resolution. Furthermore, this novel biosensing strategy is widely applicable to the immobilization of any H2O2 producing enzyme, enabling rapid monitoring of many nonelectroactive enzyme substrates.

Pyrosequencing-based validation of a simple cell-suspension polymerase chain reaction assay for Campylobacter... of high-processivity polymerase with novel internal amplification controls for rapid and specific detection.

USDA-ARS?s Scientific Manuscript database

Although Campylobacter is an important food-borne human pathogen, there remains a lack of molecular diagnostic assays that are simple to use, cost-effective, and provide rapid results in research, clinical, or regulatory laboratories. Of the numerous Campylobacter assays that do exist, to our knowl...

Development of a rapid and simple Agrobacterium tumefaciens mediated transformation system for the fungal pathogen Heterobasidion annosum

Treesearch

Nicklas Samils; Malin Elfstrand; Daniel L. Lindner Czederpiltz; Jan Fahleson; Ake Olson; Christina Dixelius; Jan Stenlid

2006-01-01

Heterobasidion annosum causes root and butt-rot in trees and is the most serious forest pathogen in the northern hemisphere. We developed a rapid and simple Agrobacterium-mediated method of gene delivery into H. annosum to be used in functional studies of candidate genes and for visualization of mycelial interactions. Heterobasidion annosum TC 32-1 was cocultivated at...

HERUS: the far-IR/submm spectral energy distributions of local ULIRGs and photometric atlas

NASA Astrophysics Data System (ADS)

Clements, D. L.; Pearson, C.; Farrah, D.; Greenslade, J.; Bernard-Salas, Jeronimo; González-Alfonso, E.; Afonso, J.; Efstathiou, A.; Rigopoulou, D.; Lebouteiller, V.; Hurley, P. D.; Spoon, H.

2018-04-01

We present the Herschel-SPIRE photometric atlas for a complete flux limited sample of 43 local ultraluminous infrared galaxies (ULIRGs), selected at 60 μm by IRAS, as part of the HERschel ULIRG Survey (HERUS). Photometry observations were obtained using the SPIRE instrument at 250, 350, and 500 μm. We describe these observations, present the results, and combine the new observations with data from IRAS to examine the far-infrared spectral energy distributions (SEDs) of these sources. We fit the observed SEDs of HERUS objects with a simple parametrized modified blackbody model, where temperature and emissivity β are free parameters. We compare the fitted values to those of non-ULIRG local galaxies, and find, in agreement with earlier results, that HERUS ULIRGs have warmer dust (median temperature T = 37.9 ± 4.7 K compared to 21.3 ± 3.4 K) but a similar β distribution (median β = 1.7 compared to 1.8) to the Herschel reference sample (HRS, Cortese et al. 2014) galaxies. Dust masses are found to be in the range of 107.5-109 M⊙, significantly higher than that of HRS sources. We compare our results for local ULIRGs with higher redshift samples selected at 250 and 850 μm. These latter sources generally have cooler dust and/or redder 100-to-250 μm colours than our 60 μm-selected ULIRGs. We show that this difference may in part be the result of the sources being selected at different wavelengths rather than being a simple indication of rapid evolution in the properties of the population.

Spatial inventory integrating raster databases and point sample data. [Geographic Information System for timber inventory

NASA Technical Reports Server (NTRS)

Strahler, A. H.; Woodcock, C. E.; Logan, T. L.

1983-01-01

A timber inventory of the Eldorado National Forest, located in east-central California, provides an example of the use of a Geographic Information System (GIS) to stratify large areas of land for sampling and the collection of statistical data. The raster-based GIS format of the VICAR/IBIS software system allows simple and rapid tabulation of areas, and facilitates the selection of random locations for ground sampling. Algorithms that simplify the complex spatial pattern of raster-based information, and convert raster format data to strings of coordinate vectors, provide a link to conventional vector-based geographic information systems.

Computational Design of Tunable UV-Vis-IR Filters Based on Silver Nanoparticle Arrays

NASA Astrophysics Data System (ADS)

Waters, Michael; Shi, Guangsha; Kioupakis, Emmanouil

We propose design strategies to develop selective optical filters in the UV-Vis-IR spectrum using the surface plasmon response of silver nanoparticle arrays. Our finite-difference time-domain simulations allow us to rapidly evaluate many nanostructures comprising simple geometries while varying their shape, height, width, and spacing. Our results allow us to identify trends in the filtering spectra as well as the relative amount of absorption and reflection. Optical filtering with nanoparticles is applicable to any transparent substrate and can be easily adapted to existing manufacturing processes while keeping the total cost of materials low. This work was supported by Guardian Industries Corp.

Method for calculation of light field characteristics in optical diagnosis problems and personalized laser treatment of biological tissues

NASA Astrophysics Data System (ADS)

Lisenko, S. A.; Kugeiko, M. M.

2013-05-01

We have developed a simple method for solving the radiation transport equation, permitting us to rapidly calculate (with accuracy acceptable in practice) the diffuse reflection coeffi cient for a broad class of biological tissues in the spectral region of strong and weak absorption of light, and also the light flux distribution over the depth of the tissue. We show that it is feasible to use the proposed method for quantitative estimates of tissue parameters from its diffuse reflectance spectrum and also for selecting the irradiation dose which is optimal for a specifi c patient in laser therapy for various diseases.

A novel sgRNA selection system for CRISPR-Cas9 in mammalian cells.

PubMed

Zhang, Haiwei; Zhang, Xixi; Fan, Cunxian; Xie, Qun; Xu, Chengxian; Zhao, Qun; Liu, Yongbo; Wu, Xiaoxia; Zhang, Haibing

2016-03-18

CRISPR-Cas9 mediated genome editing system has been developed as a powerful tool for elucidating the function of genes through genetic engineering in multiple cells and organisms. This system takes advantage of a single guide RNA (sgRNA) to direct the Cas9 endonuclease to a specific DNA site to generate mutant alleles. Since the targeting efficiency of sgRNAs to distinct DNA loci can vary widely, there remains a need for a rapid, simple and efficient sgRNA selection method to overcome this limitation of the CRISPR-Cas9 system. Here we report a novel system to select sgRNA with high efficacy for DNA sequence modification by a luciferase assay. Using this sgRNAs selection system, we further demonstrated successful examples of one sgRNA for generating one gene knockout cell lines where the targeted genes are shown to be functionally defective. This system provides a potential application to optimize the sgRNAs in different species and to generate a powerful CRISPR-Cas9 genome-wide screening system with minimum amounts of sgRNAs. Copyright © 2016 Elsevier Inc. All rights reserved.

Rapid orthodontic extrusion using an interocclusal appliance for the reestablishment of biologic width: a case report.

PubMed

Kim, Sung Hyun; Tramontina, Vinicius Augusto; Papalexiou, Vula; Luczyszyn, Sônia Mara; Grassi, Maria Bibiana; de Fatima Scarpim, Maria; Tanaka, Orlando Motohiro

2011-03-01

A multidisciplinary treatment of a case of subgingival fracture in a maxillary anterior tooth is presented. This case report describes a simple method involving an interocclusal appliance and an elastic band for rapid orthodontic extrusion to reestablish biologic width. In addition, a simple technique for surgical recontouring following the coronal displacement of the gingival margin prior to restoration of fractured tooth is explained.

A simple, rapid and inexpensive screening method for the identification of Pythium insidiosum.

PubMed

Tondolo, Juliana Simoni Moraes; Loreto, Erico Silva; Denardi, Laura Bedin; Mario, Débora Alves Nunes; Alves, Sydney Hartz; Santurio, Janio Morais

2013-04-01

Growth of Pythium insidiosum mycelia around minocycline disks (30μg) did not occur within 7days of incubation at 35°C when the isolates were grown on Sabouraud, corn meal, Muller-Hinton or RPMI agar. This technique offers a simple and rapid method for the differentiation of P. insidiosum from true filamentous fungi. Copyright © 2013 Elsevier B.V. All rights reserved.

Rapid on-site monitoring of Legionella pneumophila in cooling tower water using a portable microfluidic system.

PubMed

Yamaguchi, Nobuyasu; Tokunaga, Yusuke; Goto, Satoko; Fujii, Yudai; Banno, Fumiya; Edagawa, Akiko

2017-06-08

Legionnaires' disease, predominantly caused by the bacterium Legionella pneumophila, has increased in prevalence worldwide. The most common mode of transmission of Legionella is inhalation of contaminated aerosols, such as those generated by cooling towers. Simple, rapid and accurate methods to enumerate L. pneumophila are required to prevent the spread of this organism. Here, we applied a microfluidic device for on-chip fluorescent staining and semi-automated counting of L. pneumophila in cooling tower water. We also constructed a portable system for rapid on-site monitoring and used it to enumerate target bacterial cells rapidly flowing in the microchannel. A fluorescently-labelled polyclonal antibody was used for the selective detection of L. pneumophila serogroup 1 in the samples. The counts of L. pneumophila in cooling tower water obtained using the system and fluorescence microscopy were similar. The detection limit of the system was 10 4  cells/ml, but lower numbers of L. pneumophila cells (10 1 to 10 3  cells/ml) could be detected following concentration of 0.5-3 L of the water sample by filtration. Our technique is rapid to perform (1.5 h), semi-automated (on-chip staining and counting), and portable for on-site measurement, and it may therefore be effective in the initial screening of Legionella contamination in freshwater.

Novel Accurate Bacterial Discrimination by MALDI-Time-of-Flight MS Based on Ribosomal Proteins Coding in S10-spc-alpha Operon at Strain Level S10-GERMS

NASA Astrophysics Data System (ADS)

Tamura, Hiroto; Hotta, Yudai; Sato, Hiroaki

2013-08-01

Matrix-assisted laser-desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is one of the most widely used mass-based approaches for bacterial identification and classification because of the simple sample preparation and extremely rapid analysis within a few minutes. To establish the accurate MALDI-TOF MS bacterial discrimination method at strain level, the ribosomal subunit proteins coded in the S 10-spc-alpha operon, which encodes half of the ribosomal subunit protein and is highly conserved in eubacterial genomes, were selected as reliable biomarkers. This method, named the S10-GERMS method, revealed that the strains of genus Pseudomonas were successfully identified and discriminated at species and strain levels, respectively; therefore, the S10-GERMS method was further applied to discriminate the pathovar of P. syringae. The eight selected biomarkers (L24, L30, S10, S12, S14, S16, S17, and S19) suggested the rapid discrimination of P. syringae at the strain (pathovar) level. The S10-GERMS method appears to be a powerful tool for rapid and reliable bacterial discrimination and successful phylogenetic characterization. In this article, an overview of the utilization of results from the S10-GERMS method is presented, highlighting the characterization of the Lactobacillus casei group and discrimination of the bacteria of genera Bacillus and Sphingopyxis despite only two and one base difference in the 16S rRNA gene sequence, respectively.

Validation and Application of a Simple UHPLC–MS-MS Method for the Enantiospecific Determination of Warfarin in Human Urine

PubMed Central

Alshogran, Osama Y.; Ocque, Andrew J.; Leblond, François A.; Pichette, Vincent; Nolin, Thomas D.

2016-01-01

A simple and rapid liquid chromatographic–tandem mass spectrometric method has been developed and validated for the enantiospecific determination of R- and S-warfarin in human urine. Warfarin enantiomers were extracted from urine using methyl tert-butyl ether. Chromatographic separation of warfarin enantiomers and the internal standard d5-warfarin was achieved using a Astec Chirobiotic V column with gradient mobile phase at a flow rate of 400 µL/min over 10 min. Detection was performed on a TSQ Quantum Ultra triple quadrupole mass spectrometer equipped with a heated electrospray ionization source. Analytes were detected in negative ionization mode using selected reaction monitoring. Calibration curves were linear with a correlation coefficient of ≥0.996 for both enantiomers over a concentration range of 5–500 ng/mL. The intra- and interday accuracy and precision for both analytes were within ±9.0%. Excellent extraction efficiency and negligible matrix effects were observed. The applicability of the method was demonstrated by successful measurement of warfarin enantiomers in urine of patients with kidney disease. The method is simple, accurate and reproducible and is currently being used to support warfarin pharmacokinetic studies. PMID:26657732

Reliable clinical serum analysis with reusable electrochemical sensor: Toward point-of-care measurement of the antipsychotic medication clozapine.

PubMed

Kang, Mijeong; Kim, Eunkyoung; Winkler, Thomas E; Banis, George; Liu, Yi; Kitchen, Christopher A; Kelly, Deanna L; Ghodssi, Reza; Payne, Gregory F

2017-09-15

Clozapine is one of the most promising medications for managing schizophrenia but it is under-utilized because of the challenges of maintaining serum levels in a safe therapeutic range (1-3μM). Timely measurement of serum clozapine levels has been identified as a barrier to the broader use of clozapine, which is however challenging due to the complexity of serum samples. We demonstrate a robust and reusable electrochemical sensor with graphene-chitosan composite for rapidly measuring serum levels of clozapine. Our electrochemical measurements in clinical serum from clozapine-treated and clozapine-untreated schizophrenia groups are well correlated to centralized laboratory analysis for the readily detected uric acid and for the clozapine which is present at 100-fold lower concentration. The benefits of our electrochemical measurement approach for serum clozapine monitoring are: (i) rapid measurement (≈20min) without serum pretreatment; (ii) appropriate selectivity and sensitivity (limit of detection 0.7μM); (iii) reusability of an electrode over several weeks; and (iv) rapid reliability testing to detect common error-causing problems. This simple and rapid electrochemical approach for serum clozapine measurements should provide clinicians with the timely point-of-care information required to adjust dosages and personalize the management of schizophrenia. Copyright © 2017 Elsevier B.V. All rights reserved.

Simple scale interpolator facilitates reading of graphs

NASA Technical Reports Server (NTRS)

Fetterman, D. E., Jr.

1965-01-01

Simple transparent overlay with interpolation scale facilitates accurate, rapid reading of graph coordinate points. This device can be used for enlarging drawings and locating points on perspective drawings.

Desiccation resistance: effect of cuticular hydrocarbons and water content in Drosophila melanogaster adults

PubMed Central

Cortot, Jérôme; Rihani, Karen; Cobb, Matthew; Everaerts, Claude

2018-01-01

Background The insect cuticle covers the whole body and all appendages and has bi-directionnal selective permeability: it protects against environmental stress and pathogen infection and also helps to reduce water loss. The adult cuticle is often associated with a superficial layer of fatty acid-derived molecules such as waxes and long chain hydrocarbons that prevent rapid dehydration. The waterproofing properties of cuticular hydrocarbons (CHs) depend on their chain length and desaturation number. Drosophila CH biosynthesis involves an enzymatic pathway including several elongase and desaturase enzymes. Methods The link between desiccation resistance and CH profile remains unclear, so we tested (1) experimentally selected desiccation-resistant lines, (2) transgenic flies with altered desaturase expression and (3) natural and laboratory-induced CH variants. We also explored the possible relationship between desiccation resistance, relative water content and fecundity in females. Results We found that increased desiccation resistance is linked with the increased proportion of desaturated CHs, but not with their total amount. Experimentally-induced desiccation resistance and CH variation both remained stable after many generations without selection. Conversely, flies with a higher water content and a lower proportion of desaturated CHs showed reduced desiccation resistance. This was also the case in flies with defective desaturase expression in the fat body. Discussion We conclude that rapidly acquired desiccation resistance, depending on both CH profile and water content, can remain stable without selection in a humid environment. These three phenotypes, which might be expected to show a simple relationship, turn out to have complex physiological and genetic links. PMID:29456884

A validated LC method for determination of 2,3-dichlorobenzoic acid and its associated regio isomers.

PubMed

Krishnaiah, Ch; Sri, Khagga Bhavya

2012-05-01

A simple, selective and sensitive gradient reversed-phase liquid chromatography method has been developed for the separation and determination of 2,3-dichlorobenzoic acid, which is an intermediate of the lamotrizine drug substance, and its regio isomers. The separation was achieved on a reversed-phase United States Pharmacopeia L1 (C-18) column using 0.01 M ammonium acetate buffer at pH 2.5 and methanol (50:50 v/v) mixture as mobile phase A and a methanol and water mixture (80:20 v/v) as mobile phase B in a gradient elution at flow rate 1.2 mL/min with ultraviolet detection at 210 nm. The method is found to be selective, precise, linear, accurate and robust. It was used for quality assurance and monitoring the synthetic reactions involved in the process development of lamotrizine. The method is found to be simple, rapid, specific and reliable for the determination of unreacted levels of raw materials and isomers in reaction mixtures and finished product lamotrizine. The method was fully validated as per International Conference of Harmonization guidelines and results from validation confirm that the method is highly suitable for its intended purpose. © The Author [2012]. Published by Oxford University Press. All rights reserved.

A Simple and Rapid UPLC-PDA Method for Quality Control of Nardostachys jatamansi.

PubMed

Zhang, Weize; Nan, Guo; Wu, Hong-Hua; Jiang, Miaomiao; Li, Tian-Xiang; Wang, Meng; Gao, Xiu-Mei; Zhu, Yan; Song, Yun Seon; Wang, Jiaming; Xu, Yan-Tong

2018-05-01

Nardostachys jatamansi is a well-documented herbal agent used to treat digestive and neuropsychiatric disorders in oriental medicinal systems. However, few simple, rapid, and comprehensive methods were reported for quality assessment and control of N. jatamansi . Herein, a UPLC with photodiode array detection method was developed for both fingerprint investigation of N. jatamansi and simultaneous quantitative analysis of the six serotonin transporter modulatory constituents in N. jatamansi . For chromatographic fingerprinting, 24 common peaks were selected as characteristic peaks to assess the consistency of N. jatamansi samples from different retail sources. Six of the common peaks (5, 7, 12: , and 16:  - 18: ) were identified as desoxo-narchinol A, buddleoside, isonardosinone, nardosinone, kanshone H, and (-)-aristolone, respectively, by phytochemical investigation. Five of the six compounds significantly either enhanced or inhibited serotonin transporter activity, while (-)-aristolone (18: ) didn't show any serotonin transporter activity. In quantitative analysis, the six compounds showed good linearity ( r  > 0.999) within test ranges. The precision, expressed as relative standard deviation, was in the range of 0.25 - 2.77%, and the recovery of the method was in the range of 92 - 105%. The UPLC-photodiode array detection-based fingerprint analysis and quantitative methods reported here could be used for routine quality control of N. jatamansi . Georg Thieme Verlag KG Stuttgart · New York.

Binding of human endothelium to Ulex europaeus I-coated Dynabeads: application to the isolation of microvascular endothelium.

PubMed

Jackson, C J; Garbett, P K; Nissen, B; Schrieber, L

1990-06-01

A major problem encountered when isolating human microvascular endothelium is the presence of contaminating cells such as fibroblasts that rapidly over-grow the endothelial cells. We describe here a simple, rapid technique for purifying endothelial cells derived from the microvasculature of neonatal foreskin and osteoarthritic and rheumatoid arthritic synovium. This technique is based on the selective binding of the lectin Ulex europaeus I (UEA I) to the endothelial cell surface via fucose residues. Initially UEA I was covalently bound to tosyl-activated super-paramagnetic polystyrene beads (Dynabeads) by incubation for 24 h at room temperature. Cells were isolated by extracting microvascular segments from enzyme-treated (trypsin and Pronase) cubes of tissue. The mixed population of cells obtained were purified by incubating them at 4 degrees C for 10 min with the UEA I-coated Dynabeads. Endothelium bound to the beads whilst contaminating cells were removed by five washes with HBSS using a magnetic particle concentrator. The endothelial cells thus obtained grew to confluence as a cobblestone-like monolayer and expressed von Willebrand factor antigen. The cells were released from the Dynabeads by the competitive binding of fucose (10 min at 4 degrees C). This new method is simple and reproducible and allows pure human microvascular endothelial cells to be cultured within 2 h of obtaining a specimen.

Determination of secondary and tertiary amines as N-nitrosamine precursors in drinking water system using ultra-fast liquid chromatography-tandem mass spectrometry.

PubMed

Wu, Qihua; Shi, Honglan; Ma, Yinfa; Adams, Craig; Eichholz, Todd; Timmons, Terry; Jiang, Hua

2015-01-01

N-Nitrosamines are potent mutagenic and carcinogenic emerging water disinfection by-products (DBPs). The most effective strategy to control the formation of these DBPs is minimizing their precursors from source water. Secondary and tertiary amines are dominating precursors of N-nitrosamines formation during drinking water disinfection process. Therefore, the screening and removal of these amines in source water are very essential for preventing the formation of N-nitrosamines. A rapid, simple, and sensitive ultrafast liquid chromatography-tandem mass spectrometry (UFLC-MS/MS) method has been developed in this study to determine seven amines, including dimethylamine, ethylmethylamine, diethylamine, dipropylamine, trimethylamine, 3-(dimethylaminomethyl)indole, and 4-dimethylaminoantipyrine, as major precursors of N-nitrosamines in drinking water system. No sample preparation process is needed except a simple filtration. Separation and detection can be achieved in 11 min per sample. The method detection limits of selected amines are ranging from 0.02 μg/L to 1 μg/L except EMA (5 μg/L), and good calibration linearity was achieved. The developed method was applied to determine the selected precursors in source water and drinking water samples collected from Midwest area of the United States. In most of water samples, the concentrations of selected precursors of N-nitrosamines were below their method detection limits. Dimethylamine was detected in some of water samples at the concentration up to 25.4 μg/L. Copyright © 2014 Elsevier B.V. All rights reserved.

Hemorrhagic Fever with Renal Syndrome (Korean Hemorrhagic Fever)

DTIC Science & Technology

1990-06-29

particles were used for a rapid serologic diagnostic test for HFRS. ’te-re were 430 cases of HFRS in Korea in 1989 and large outbreaks of scrub typhus...almost same as in 1988. A simple and rapid serologic diagnostic test for hantavirus infection was developed by high density particle agglutination...infection and HFRS b) serologic relation cif hantaviruses isolated from the different parts of the world c) development of a simple serologic diagnostic

Rapid identification of drug-type strains in Cannabis sativa using loop-mediated isothermal amplification assay.

PubMed

Kitamura, Masashi; Aragane, Masako; Nakamura, Kou; Watanabe, Kazuhito; Sasaki, Yohei

2017-01-01

In Cannabis sativa L., tetrahydrocannabinol (THC) is the primary psychoactive compound and exists as the carboxylated form, tetrahydrocannabinolic acid (THCA). C. sativa is divided into two strains based on THCA content-THCA-rich (drug-type) strains and THCA-poor (fiber-type) strains. Both strains are prohibited by law in many countries including Japan, whereas the drug-type strains are regulated in Canada and some European countries. As the two strains cannot be discriminated by morphological analysis, a simple method for identifying the drug-type strains is required for quality control in legal cultivation and forensic investigation. We have developed a novel loop-mediated isothermal amplification (LAMP) assay for identifying the drug-type strains of C. sativa. We designed two selective LAMP primer sets for on-site or laboratory use, which target the drug-type THCA synthase gene. The LAMP assay was accomplished within approximately 40 min. The assay showed high specificity for the drug-type strains and its sensitivity was the same as or higher than that of conventional polymerase chain reaction. We also showed the effectiveness of melting curve analysis that was conducted after the LAMP assay. The melting temperature values of the drug-type strains corresponded to those of the cloned drug-type THCA synthase gene, and were clearly different from those of the cloned fiber-type THCA synthase gene. Moreover, the LAMP assay with simple sample preparation could be accomplished within 1 h from sample treatment to identification without the need for special devices or techniques. Our rapid, sensitive, specific, and simple assay is expected to be applicable to laboratory and on-site detection.

Development of a selective and sensitive flotation method for determination of trace amounts of cobalt, nickel, copper and iron in environmental samples.

PubMed

Karimi, H; Ghaedi, M; Shokrollahi, A; Rajabi, H R; Soylak, M; Karami, B

2008-02-28

A simple, selective and rapid flotation method for the separation-preconcentration of trace amounts of cobalt, nickel, iron and copper ions using phenyl 2-pyridyl ketone oxime (PPKO) has been developed prior to their flame atomic absorption spectrometric determinations. The influence of pH, amount of PPKO as collector, type and amount of eluting agent, type and amount of surfactant as floating agent and ionic strength was evaluated on the recoveries of analytes. The influences of the concomitant ions on the recoveries of the analyte ions were also examined. The enrichment factor was 93. The detection limits based on 3 sigma for Cu, Ni, Co and Fe were 0.7, 0.7, 0.8, and 0.7 ng mL(-1), respectively. The method has been successfully applied for determination of trace amounts of ions in various real samples.

Site-Selective Copper-Catalyzed Amination and Azidation of Arenes and Heteroarenes via Deprotonative Zincation.

PubMed

Hendrick, Charles E; Bitting, Katie J; Cho, Seoyoung; Wang, Qiu

2017-08-23

Arene amination is achieved by site-selective C-H zincation followed by copper-catalyzed coupling with O-benzoylhydroxylamines under mild conditions. Key to this success is ortho-zincation mediated by lithium amidodiethylzincate base that is effective for a wide range of arenes, including nonactivated arenes bearing simple functionalities such as fluoride, chloride, ester, amide, ether, nitrile, and trifluoromethyl groups as well as heteroarenes including indole, thiophene, pyridine, and isoquinoline. An analogous C-H azidation is also accomplished using azidoiodinane for direct introduction of a useful azide group onto a broad scope of arenes and heteroarenes. These new transformations offer rapid access to valuable and diverse chemical space of aminoarenes. Their broad applications in organic synthesis and drug discovery are demonstrated in the synthesis of novel analogues of natural product (-)-nicotine and antidepressant sertraline by late-stage amination and azidation reactions.

PRINT: A Protein Bioconjugation Method with Exquisite N-terminal Specificity

PubMed Central

Sur, Surojit; Qiao, Yuan; Fries, Anja; O’Meally, Robert N.; Cole, Robert N.; Kinzler, Kenneth W.; Vogelstein, Bert; Zhou, Shibin

2015-01-01

Chemical conjugation is commonly used to enhance the pharmacokinetics, biodistribution, and potency of protein therapeutics, but often leads to non-specific modification or loss of bioactivity. Here, we present a simple, versatile and widely applicable method that allows exquisite N-terminal specific modification of proteins. Combining reversible side-chain blocking and protease mediated cleavage of a commonly used HIS tag appended to a protein, we generate with high yield and purity exquisitely site specific and selective bio-conjugates of TNF-α by using amine reactive NHS ester chemistry. We confirm the N terminal selectivity and specificity using mass spectral analyses and show near complete retention of the biological activity of our model protein both in vitro and in vivo murine models. We believe that this methodology would be applicable to a variety of potentially therapeutic proteins and the specificity afforded by this technique would allow for rapid generation of novel biologics. PMID:26678960

Graphene-multiwall carbon nanotube-gold nanocluster composites modified electrode for the simultaneous determination of ascorbic acid, dopamine, and uric acid.

PubMed

Liu, Xiaofang; Wei, Shaping; Chen, Shihong; Yuan, Dehua; Zhang, Wen

2014-08-01

In this paper, graphene-multiwall carbon nanotube-gold nanocluster (GP-MWCNT-AuNC) composites were synthesized and used as modifier to fabricate a sensor for simultaneous detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA). The electrochemical behavior of the sensor was investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The combination of GP, MWCNTs, and AuNCs endowed the electrode with a large surface area, good catalytic activity, and high selectivity and sensitivity. The linear response range for simultaneous detection of AA, DA, and UA at the sensor were 120-1,701, 2-213, and 0.7-88.3 μM, correspondingly, and the detection limits were 40, 0.67, and 0.23 μM (S/N=3), respectively. The proposed method offers a promise for simple, rapid, selective, and cost-effective analysis of small biomolecules.

In silico selection of therapeutic antibodies for development: Viscosity, clearance, and chemical stability

PubMed Central

Sharma, Vikas K.; Patapoff, Thomas W.; Kabakoff, Bruce; Pai, Satyan; Hilario, Eric; Zhang, Boyan; Li, Charlene; Borisov, Oleg; Kelley, Robert F.; Chorny, Ilya; Zhou, Joe Z.; Dill, Ken A.; Swartz, Trevor E.

2014-01-01

For mAbs to be viable therapeutics, they must be formulated to have low viscosity, be chemically stable, and have normal in vivo clearance rates. We explored these properties by observing correlations of up to 60 different antibodies of the IgG1 isotype. Unexpectedly, we observe significant correlations with simple physical properties obtainable from antibody sequences and by molecular dynamics simulations of individual antibody molecules. mAbs viscosities increase strongly with hydrophobicity and charge dipole distribution and decrease with net charge. Fast clearance correlates with high hydrophobicities of certain complementarity determining regions and with high positive or high negative net charge. Chemical degradation from tryptophan oxidation correlates with the average solvent exposure time of tryptophan residues. Aspartic acid isomerization rates can be predicted from solvent exposure and flexibility as determined by molecular dynamics simulations. These studies should aid in more rapid screening and selection of mAb candidates during early discovery. PMID:25512516

An easy prepared dual-channel chemosensor for selective and instant detection of fluoride based on double Schiff-base

NASA Astrophysics Data System (ADS)

Leng, Yan-Li; Zhang, Jian-Hui; Li, Qiao; Zhang, You-Ming; Lin, Qi; Yao, Hong; Wei, Tai-Bao

2016-10-01

A colorimetric and fluorescent dual-channel fluoride chemosensor N,N‧-bis (4-diethylaminosalicylidene) hydrazine (sensor S) bearing two imine groups has been designed and synthesized. This structurally simple probe displays rapid response and high selectivity for fluoride over other common anions (Cl-, Br-, I-, AcO-, H2PO4-, HSO4-, ClO4-, CN- and SCN-) in a highly polar aqueous DMSO solution. Mechanism studies suggested that the sensor firstly combined with F- through hydrogen bonds and then experienced the deprotonation process at higher concentrations of F- anion to the two Ar-OH groups. The detection limit was 5.78 × 10- 7 M of F-, which points to the high detection sensitivity. Test strips based on sensor S were fabricated, which could act as a convenient and efficient F- test kit to detect F- for ;in-the-field; measurement.

Synthesis of a multi-functional DNA nanosphere barcode system for direct cell detection.

PubMed

Han, Sangwoo; Lee, Jae Sung; Lee, Jong Bum

2017-09-28

Nucleic acid-based technologies have been applied to numerous biomedical applications. As a novel material for target detection, DNA has been used to construct a barcode system with a range of structures. This paper reports multi-functionalized DNA nanospheres (DNANSs) by rolling circle amplification (RCA) with several functionalized nucleotides. DNANSs with a barcode system were designed to exhibit fluorescence for coding enhanced signals and contain biotin for more functionalities, including targeting through the biotin-streptavidin (biotin-STA) interaction. Functionalized deoxynucleotide triphosphates (dNTPs) were mixed in the RCA process and functional moieties can be expressed on the DNANSs. The anti-epidermal growth factor receptor antibodies (anti-EGFR Abs) can be conjugated on DNANSs for targeting cancer cells specifically. As a proof of concept, the potential of the multi-functional DNANS barcode was demonstrated by direct cell detection as a simple detection method. The DNANS barcode provides a new route for the simple and rapid selective recognition of cancer cells.

Indirect glyphosate detection based on ninhydrin reaction and surface-enhanced Raman scattering spectroscopy

NASA Astrophysics Data System (ADS)

Xu, Meng-Lei; Gao, Yu; Li, Yali; Li, Xueliang; Zhang, Huanjie; Han, Xiao Xia; Zhao, Bing; Su, Liang

2018-05-01

Glyphosate is one of the most commonly-used and non-selective herbicides in agriculture, which may directly pollute the environment and threaten human health. A simple and effective approach to assessment of its damage to the natural environment is thus quite necessary. However, traditional chromatography-based detection methods usually suffer from complex pretreatment procedures. Herein, we propose a simple and sensitive method for the determination of glyphosate by combining ninhydrin reaction and surface-enhanced Raman scattering (SERS) spectroscopy. The product (purple color dye, PD) of the ninhydrin reaction is found to SERS-active and directly correlate with the glyphosate concentration. The limit of detection of the proposed method for glyphosate is as low as 1.43 × 10- 8 mol·L- 1 with a relatively wider linear concentration range (1.0 × 10- 7-1.0 × 10- 4 mol·L- 1), which demonstrates its great potential in rapid, highly sensitive concentration determination of glyphosate in practical applications for safety assessment of food and environment.

A Simple and Sensitive Method for Auramine O Detection Based on the Binding Interaction with Bovin Serum Albumin.

PubMed

Yan, Jingjing; Huang, Xin; Liu, Shaopu; Yang, Jidong; Yuan, Yusheng; Duan, Ruilin; Zhang, Hui; Hu, Xiaoli

2016-01-01

A simple, rapid and effective method for auramine O (AO) detection was proposed by fluorescence and UV-Vis absorption spectroscopy. In the BR buffer system (pH 7.0), AO had a strong quenching ability to the fluorescence of bovin serum albumin (BSA) by dynamic quenching. In terms of the thermodynamic parameters calculated as ΔH > 0 and ΔS > 0, the resulting binding of BSA and AO was mainly attributed to the hydrophobic interaction forces. The linearity of this method was in the concentration range from 0.16 to 50 μmol L(-1) with a detection limit of 0.05 μmol L(-1). Based on fluorescence resonance energy transfer (FRET), the distance r (1.36 nm) between donor (BSA) and acceptor (AO) was obtained. Furthermore, the effects of foreign substances and ionic strength were evaluated under the optimum reaction conditions. BSA as a selective probe could be applied to the analysis of AO in medicines with satisfactory results.

Multi-Criteria Decision Making For Determining A Simple Model of Supplier Selection

NASA Astrophysics Data System (ADS)

Harwati

2017-06-01

Supplier selection is a decision with many criteria. Supplier selection model usually involves more than five main criteria and more than 10 sub-criteria. In fact many model includes more than 20 criteria. Too many criteria involved in supplier selection models sometimes make it difficult to apply in many companies. This research focuses on designing supplier selection that easy and simple to be applied in the company. Analytical Hierarchy Process (AHP) is used to weighting criteria. The analysis results there are four criteria that are easy and simple can be used to select suppliers: Price (weight 0.4) shipment (weight 0.3), quality (weight 0.2) and services (weight 0.1). A real case simulation shows that simple model provides the same decision with a more complex model.

Sensitive SERS detection of lead ions via DNAzyme based quadratic signal amplification.

PubMed

Tian, Aihua; Liu, Yu; Gao, Jian

2017-08-15

Highly sensitive detection of Pb 2+ is very necessary for water quality control, clinical toxicology, and industrial monitoring. In this work, a simple and novel DNAzyme-based SERS quadratic amplification method is developed for the detection of Pb 2+ . This strategy possesses some remarkable features compared to the conventional DNAzyme-based SERS methods, which are as follows: (i) Coupled DNAzyme-activated hybridization chain reaction (HCR) with bio barcodes; a quadratic amplification method is designed using the unique catalytic selectivity of DNAzyme. The SERS signal is significantly amplified. This method is rapid with a detection time of 2h. (ii) The problem of high background induced by excess bio barcodes is circumvented by using magnetic beads (MBs) as the carrier of signal-output products, and this sensing system is simple in design and can easily be carried out by simple mixing and incubation. Given the unique and attractive characteristics, a simple and universal strategy is designed to accomplish sensitive detection of Pb 2+ . The detection limit of Pb 2+ via SERS detection is 70 fM, with the linear range from 1.0×10 -13 M to 1.0×10 -7 M. The method can be further extended to the quantitative detection of a variety of targets by replacing the lead-responsive DNAzyme with other functional DNA. Copyright © 2017 Elsevier B.V. All rights reserved.

Selection of a novel peptide aptamer with high affinity for TiO2-nanoparticle through a direct electroporation with TiO2-binding phage complexes.

PubMed

Inoue, Ippei; Ishikawa, Yasuaki; Uraoka, Yukiharu; Yamashita, Ichiro; Yasueda, Hisashi

2016-11-01

We have developed an easy and rapid screening method of peptide aptamers with high affinity for a target material TiO 2 using M13 phage-display and panning procedure. In a selection step, the phage-substrate complexes and Escherichia coli cells were directly applied by electric pulse for electroporation, without separating the objective phages from the TiO 2 nanoparticles. Using this simple and rapid method, we obtained a novel peptide aptamer (named ST-1 with the sequence AYPQKFNNNFMS) with highly strong binding activity for TiO 2 . A cage-shaped protein fused with both ST-1 and an available carbon nanotube-affinity peptide was designed and produced in E. coli. The multi-functional supraprotein could efficiently mineralize a titanium-compound around the surface of single-wall carbon nanotubes (SWNTs), indicating that the ST-1 is valuable in the fabrication of nano-composite materials with titanium-compounds. The structural analysis of ST-1 variants indicated the importance of the N-terminal region (as a motif of AXPQKX 6 S) of the aptamer in the TiO 2 -binding activity. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Selective and rapid determination of tadalafil and finasteride using solid phase extraction by high performance liquid chromatography and tandem mass spectrometry.

PubMed

Pappula, Nagaraju; Kodali, Balaji; Datla, Peda Varma

2018-04-15

Highly selective and fast liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and validated for simultaneous determination of tadalafil (TDL) and finasteride (FNS) in human plasma. The method was successfully applied for analysis of TDL and FNS samples in clinical study. The method was validated as per USFDA (United States Food and Drug Administration), EMA (European Medicines Agency), and ANVISA (Agência Nacional de Vigilância Sanitária-Brazil) bio analytical method validation guidelines. Glyburide (GLB) was used as common internal standard (ISTD) for both analytes. The selected multiple reaction monitoring (MRM) transitions for mass spectrometric analysis were m/z 390.2/268.2, m/z 373.3/305.4 and m/z 494.2/369.1 for TDL, FNS and ISTD respectively. The extraction of analytes and ISTD was accomplished by a simple solid phase extraction (SPE) procedure. Rapid analysis time was achieved on Zorbax Eclipse C18 column (50 × 4.6 mm, 5 μm). The calibration ranges for TDL and FNS were 5-800 ng/ml and 0.2-30 ng/ml respectively. The results of precision and accuracy, linearity, recovery and matrix effect of the method are acceptable. The accuracy was in the range of 92.9%-106.4% and method precision was also good; %CV was less than 8.1%. Copyright © 2018 Elsevier B.V. All rights reserved.

Label-Free Nanopore Biosensor for Rapid and Highly Sensitive Cocaine Detection in Complex Biological Fluids.

PubMed

Rauf, Sana; Zhang, Ling; Ali, Asghar; Liu, Yang; Li, Jinghong

2017-02-24

Detection of very low amounts of illicit drugs such as cocaine in clinical fluids like serum continues to be important for many areas in the fight against drug trafficking. Herein, we constructed a label-free nanopore biosensor for rapid and highly sensitive detection of cocaine in human serum and saliva samples based on target-induced strand release strategy. In this bioassay, an aptamer for cocaine was prehybridized with a short complementary DNA. Owing to cocaine specific binding with aptamer, the short DNA strand was displaced from aptamer and translocation of this output DNA through α-hemolysin nanopore generated distinct spike-like current blockages. When plotted in double-logarithmic scale, a linear relationship between target cocaine concentration and output DNA event frequency was obtained in a wide concentration range from 50 nM to 100 μM of cocaine, with the limit of detection down to 50 nM. In addition, this aptamer-based sensor method was successfully applied for cocaine detection in complex biological fluids like human saliva and serum samples with great selectivity. Simple preparation, low cost, rapid, label-free, and real sample detection are the motivating factors for practical application of the proposed biosensor.

Rapid parallel evolution overcomes global honey bee parasite.

PubMed

Oddie, Melissa; Büchler, Ralph; Dahle, Bjørn; Kovacic, Marin; Le Conte, Yves; Locke, Barbara; de Miranda, Joachim R; Mondet, Fanny; Neumann, Peter

2018-05-16

In eusocial insect colonies nestmates cooperate to combat parasites, a trait called social immunity. However, social immunity failed for Western honey bees (Apis mellifera) when the ectoparasitic mite Varroa destructor switched hosts from Eastern honey bees (Apis cerana). This mite has since become the most severe threat to A. mellifera world-wide. Despite this, some isolated A. mellifera populations are known to survive infestations by means of natural selection, largely by supressing mite reproduction, but the underlying mechanisms of this are poorly understood. Here, we show that a cost-effective social immunity mechanism has evolved rapidly and independently in four naturally V. destructor-surviving A. mellifera populations. Worker bees of all four 'surviving' populations uncapped/recapped worker brood cells more frequently and targeted mite-infested cells more effectively than workers in local susceptible colonies. Direct experiments confirmed the ability of uncapping/recapping to reduce mite reproductive success without sacrificing nestmates. Our results provide striking evidence that honey bees can overcome exotic parasites with simple qualitative and quantitative adaptive shifts in behaviour. Due to rapid, parallel evolution in four host populations this appears to be a key mechanism explaining survival of mite infested colonies.

Binding stability of peptides on major histocompatibility complex class I proteins: role of entropy and dynamics.

PubMed

Gul, Ahmet; Erman, Burak

2018-01-16

Prediction of peptide binding on specific human leukocyte antigens (HLA) has long been studied with successful results. We herein describe the effects of entropy and dynamics by investigating the binding stabilities of 10 nanopeptides on various HLA Class I alleles using a theoretical model based on molecular dynamics simulations. The fluctuational entropies of the peptides are estimated over a temperature range of 310-460 K. The estimated entropies correlate well with experimental binding affinities of the peptides: peptides that have higher binding affinities have lower entropies compared to non-binders, which have significantly larger entropies. The computation of the entropies is based on a simple model that requires short molecular dynamics trajectories and allows for approximate but rapid determination. The paper draws attention to the long neglected dynamic aspects of peptide binding, and provides a fast computation scheme that allows for rapid scanning of large numbers of peptides on selected HLA antigens, which may be useful in defining the right peptides for personal immunotherapy.

Mini-column assay for rapid detection of malachite green in fish.

PubMed

Shalaby, Ali R; Emam, Wafaa H; Anwar, Mervat M

2017-07-01

A simple, rapid and economical mini-column method for detecting malachite green (MG) residue in fish was developed. The method used a column with 2mm ID that was tightly packed with silica gel followed by alumina. Detection of MG was performed by viewing the developed mini-column at visible light by naked eye; where MG was seen as compact green band at the confluence of the silica gel layer with alumina layer. The limit of detection of the assay was 2ng which conform the minimum required performance limit (MRPL). Evaluation utility of the method indicated that all blank and spiked samples at levels below MRPL were assessed as accepted. The intensity of the green band increased whenever MG level in the extract increased; indicated that suggested mini-column technique could be used for semi-quantitative determination of MG in fish samples. The method can be used to select the questionable samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rapid and efficient method to extract metagenomic DNA from estuarine sediments.

PubMed

Shamim, Kashif; Sharma, Jaya; Dubey, Santosh Kumar

2017-07-01

Metagenomic DNA from sediments of selective estuaries of Goa, India was extracted using a simple, fast, efficient and environment friendly method. The recovery of pure metagenomic DNA from our method was significantly high as compared to other well-known methods since the concentration of recovered metagenomic DNA ranged from 1185.1 to 4579.7 µg/g of sediment. The purity of metagenomic DNA was also considerably high as the ratio of absorbance at 260 and 280 nm ranged from 1.88 to 1.94. Therefore, the recovered metagenomic DNA was directly used to perform various molecular biology experiments viz. restriction digestion, PCR amplification, cloning and metagenomic library construction. This clearly proved that our protocol for metagenomic DNA extraction using silica gel efficiently removed the contaminants and prevented shearing of the metagenomic DNA. Thus, this modified method can be used to recover pure metagenomic DNA from various estuarine sediments in a rapid, efficient and eco-friendly manner.

Binding stability of peptides on major histocompatibility complex class I proteins: role of entropy and dynamics

NASA Astrophysics Data System (ADS)

Gul, Ahmet; Erman, Burak

2018-03-01

Prediction of peptide binding on specific human leukocyte antigens (HLA) has long been studied with successful results. We herein describe the effects of entropy and dynamics by investigating the binding stabilities of 10 nanopeptides on various HLA Class I alleles using a theoretical model based on molecular dynamics simulations. The fluctuational entropies of the peptides are estimated over a temperature range of 310-460 K. The estimated entropies correlate well with experimental binding affinities of the peptides: peptides that have higher binding affinities have lower entropies compared to non-binders, which have significantly larger entropies. The computation of the entropies is based on a simple model that requires short molecular dynamics trajectories and allows for approximate but rapid determination. The paper draws attention to the long neglected dynamic aspects of peptide binding, and provides a fast computation scheme that allows for rapid scanning of large numbers of peptides on selected HLA antigens, which may be useful in defining the right peptides for personal immunotherapy.

A novel colorimetric assay for rapid detection of cysteine and Hg²⁺ based on gold clusters.

PubMed

Wang, Yi-Wei; Tang, Shurong; Yang, Huang-Hao; Song, Hongbo

2016-01-01

Inhibition and recovery of the catalytic activity of bovine serum albumin-capped gold nanoclusters (BSA-AuNCs) is observed for the first time by introduction of cysteine and Hg(2+). The prepared BSA-AuNCs possess highly intrinsic peroxidase-like activity. It can catalyze the oxidation of 3, 3, 5, 5-tetramethylbenzidine by H2O2 to produce a blue colored product. Based on this phenomenon, a new colorimetric assay for rapid, selective and sensitive detection of cysteine and Hg(2+) in aqueous solution has been demonstrated. The interaction process between target molecule and BSA-AuNCs is very fast, so that the whole test can be completed within ten minutes. Moreover, the fabricated colorimetric sensor is simple and cost-effective, without the need of nucleic acid based recognition element and complicated washing, separation and labeling process, thus holds great promise for routine analysis of cysteine and Hg(2+) in real samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Unlocking Chain Exchange in Highly Amphiphilic Block Polymer Micellar Systems: Influence of Agitation.

PubMed

Murphy, Ryan P; Kelley, Elizabeth G; Rogers, Simon A; Sullivan, Millicent O; Epps, Thomas H

2014-11-18

Chain exchange between block polymer micelles in highly selective solvents, such as water, is well-known to be arrested under quiescent conditions, yet this work demonstrates that simple agitation methods can induce rapid chain exchange in these solvents. Aqueous solutions containing either pure poly(butadiene- b -ethylene oxide) or pure poly(butadiene- b -ethylene oxide- d 4 ) micelles were combined and then subjected to agitation by vortex mixing, concentric cylinder Couette flow, or nitrogen gas sparging. Subsequently, the extent of chain exchange between micelles was quantified using small angle neutron scattering. Rapid vortex mixing induced chain exchange within minutes, as evidenced by a monotonic decrease in scattered intensity, whereas Couette flow and sparging did not lead to measurable chain exchange over the examined time scale of hours. The linear kinetics with respect to agitation time suggested a surface-limited exchange process at the air-water interface. These findings demonstrate the strong influence of processing conditions on block polymer solution assemblies.

Validation of the ANSR® Listeria Method for Detection of Listeria spp. in Selected Foods.

PubMed

Caballero, Oscar; Alles, Susan; Wendorf, Michael; Gray, R Lucas; Walton, Kayla; Pinkava, Lisa; Mozola, Mark; Rice, Jennifer

2015-01-01

ANSR® Listeria was previously certified as Performance Tested Method(SM) 101202 for detection of Listeria spp. on selected environmental surfaces. This study proposes a matrix extension to the method for detection of Listeria spp. in selected food matrixes. The method is an isothermal nucleic acid amplification assay based on the nicking enzyme amplification reaction technology. Following single-step sample enrichment for 16-24 h, the assay is completed in less than 50 min, requiring only simple instrumentation. Inclusivity testing was performed using a panel of 51 strains of Listeria spp., representing the species L. grayi, L. innocua, L. ivanovii, L. monocytogenes, L. seeligeri, and L. welshimeri. All strains tested were detected by the ANSR assay. Exclusivity testing of 30 strains representing non-Listeria Gram-positive bacteria yielded no evidence of cross-reactivity. Performance of the ANSR method for detection of Listeria spp. was compared to that of reference culture procedures for pasteurized liquid egg, pasteurized 2% milk, Mexican-style cheese, ice cream, smoked salmon, lettuce, cantaloupe, and guacamole. Data obtained in these unpaired studies and analyzed using a probability of detection model demonstrated that there were no statistically significant differences in results between the ANSR and reference culture methods, except for milk at 16 h and cantaloupe. In milk and smoked salmon, ANSR sensitivity was low at 16 h and therefore the recommended incubation time is 24 h. In cantaloupe, ANSR was found to be more sensitive than the reference culture method at both 16 and 24 h in independent laboratory testing. The ANSR Listeria method can be used as an accurate, rapid, and simple alternative to standard culture methods for detection of Listeria spp. in selected food types.

TableViewer for Herschel Data Processing

NASA Astrophysics Data System (ADS)

Zhang, L.; Schulz, B.

2006-07-01

The TableViewer utility is a GUI tool written in Java to support interactive data processing and analysis for the Herschel Space Observatory (Pilbratt et al. 2001). The idea was inherited from a prototype written in IDL (Schulz et al. 2005). It allows to graphically view and analyze tabular data organized in columns with equal numbers of rows. It can be run either as a standalone application, where data access is restricted to FITS (FITS 1999) files only, or it can be run from the Quick Look Analysis(QLA) or Interactive Analysis(IA) command line, from where also objects are accessible. The graphic display is very versatile, allowing plots in either linear or log scales. Zooming, panning, and changing data columns is performed rapidly using a group of navigation buttons. Selecting and de-selecting of fields of data points controls the input to simple analysis tasks like building a statistics table, or generating power spectra. The binary data stored in a TableDataset^1, a Product or in FITS files can also be displayed as tabular data, where values in individual cells can be modified. TableViewer provides several processing utilities which, besides calculation of statistics either for all channels or for selected channels, and calculation of power spectra, allows to convert/repair datasets by changing the unit name of data columns, and by modifying data values in columns with a simple calculator tool. Interactively selected data can be separated out, and modified data sets can be saved to FITS files. The tool will be very helpful especially in the early phases of Herschel data analysis when a quick access to contents of data products is important. TableDataset and Product are Java classes defined in herschel.ia.dataset.

Determination of tocopheryl acetate and ascorbyl tetraisopalmitate in cosmetic formulations by HPLC.

PubMed

Almeida, M M; Alves, J M P; Patto, D C S; Lima, C R R C; Quenca-Guillen, J S; Santoro, M I R M; Kedor-Hackmann, E R M

2009-12-01

A rapid HPLC method was developed for the assay of tocopheryl acetate and ascorbyl tetraisopalmitate in cosmetic formulations. The validated method was applied for quantitative determination of these vitamins in simulated emulsion formulation. Samples were analysed directly on a RP-18 reverse phase column with UV detection at 222 nm. A mixture of methanol and isopropanol (25 : 75 v/v) was used as mobile phase. The retention time of tocopheryl acetate and ascorbyl tetraisopalmitate were 3.0 min and 5.9 min, respectively. Recovery was between 95% and 104%. In addition, the excipients did not interfere in the analysis. The method is simple, reproducible, selective and is suitable for routine analyses of commercial products.

A novel method for the rapid detection of benzo(a)pyrene in liquid milk by dimethyl sulfoxide selectively enhanced synchronous fluorescence spectrometry.

PubMed

Lin, Li-Rong; Luo, He-Dong; Li, Xiu-Ying; Li, Na; Zhou, Na; Jia, Yu-Zhu; Liu, Yi-Hong; Li, Yao-Qun

2014-01-01

Based on the high solubility efficiency and strong fluorescence response of benzo(a)pyrene (BaP) in dimethyl sulfoxide in combination with the high-performance derivative constant-energy synchronous fluorescence spectroscopic (DCESFS) technique, a simple, sensitive and economic method was developed for the determination of BaP in liquid milk. This method comprises ultrasound-assisted solvent extraction, solvent replacement and DCESFS detection. No saponification or other tedious clean-up procedures were needed. The recoveries of BaP in different milk samples were greater than 82%. Detection limits in full- and low-fat milk were 0.03 and 0.04 μg kg(-1), respectively.

Registration of Heat Capacity Mapping Mission day and night images

NASA Technical Reports Server (NTRS)

Watson, K.; Hummer-Miller, S.; Sawatzky, D. L. (Principal Investigator)

1982-01-01

Neither iterative registration, using drainage intersection maps for control, nor cross correlation techniques were satisfactory in registering day and night HCMM imagery. A procedure was developed which registers the image pairs by selecting control points and mapping the night thermal image to the daytime thermal and reflectance images using an affine transformation on a 1300 by 1100 pixel image. The resulting image registration is accurate to better than two pixels (RMS) and does not exhibit the significant misregistration that was noted in the temperature-difference and thermal-inertia products supplied by NASA. The affine transformation was determined using simple matrix arithmetic, a step that can be performed rapidly on a minicomputer.

Synaptic Basis for Differential Orientation Selectivity between Complex and Simple Cells in Mouse Visual Cortex

PubMed Central

Li, Ya-tang; Liu, Bao-hua; Chou, Xiao-lin; Zhang, Li I.

2015-01-01

In the primary visual cortex (V1), orientation-selective neurons can be categorized into simple and complex cells primarily based on their receptive field (RF) structures. In mouse V1, although previous studies have examined the excitatory/inhibitory interplay underlying orientation selectivity (OS) of simple cells, the synaptic bases for that of complex cells have remained obscure. Here, by combining in vivo loose-patch and whole-cell recordings, we found that complex cells, identified by their overlapping on/off subfields, had significantly weaker OS than simple cells at both spiking and subthreshold membrane potential response levels. Voltage-clamp recordings further revealed that although excitatory inputs to complex and simple cells exhibited a similar degree of OS, inhibition in complex cells was more narrowly tuned than excitation, whereas in simple cells inhibition was more broadly tuned than excitation. The differential inhibitory tuning can primarily account for the difference in OS between complex and simple cells. Interestingly, the differential synaptic tuning correlated well with the spatial organization of synaptic input: the inhibitory visual RF in complex cells was more elongated in shape than its excitatory counterpart and also was more elongated than that in simple cells. Together, our results demonstrate that OS of complex and simple cells is differentially shaped by cortical inhibition based on its orientation tuning profile relative to excitation, which is contributed at least partially by the spatial organization of RFs of presynaptic inhibitory neurons. SIGNIFICANCE STATEMENT Simple and complex cells, two classes of principal neurons in the primary visual cortex (V1), are generally thought to be equally selective for orientation. In mouse V1, we report that complex cells, identified by their overlapping on/off subfields, has significantly weaker orientation selectivity (OS) than simple cells. This can be primarily attributed to the differential tuning selectivity of inhibitory synaptic input: inhibition in complex cells is more narrowly tuned than excitation, whereas in simple cells inhibition is more broadly tuned than excitation. In addition, there is a good correlation between inhibitory tuning selectivity and the spatial organization of inhibitory inputs. These complex and simple cells with differential degree of OS may provide functionally distinct signals to different downstream targets. PMID:26245969

Synaptic Basis for Differential Orientation Selectivity between Complex and Simple Cells in Mouse Visual Cortex.

PubMed

Li, Ya-tang; Liu, Bao-hua; Chou, Xiao-lin; Zhang, Li I; Tao, Huizhong W

2015-08-05

In the primary visual cortex (V1), orientation-selective neurons can be categorized into simple and complex cells primarily based on their receptive field (RF) structures. In mouse V1, although previous studies have examined the excitatory/inhibitory interplay underlying orientation selectivity (OS) of simple cells, the synaptic bases for that of complex cells have remained obscure. Here, by combining in vivo loose-patch and whole-cell recordings, we found that complex cells, identified by their overlapping on/off subfields, had significantly weaker OS than simple cells at both spiking and subthreshold membrane potential response levels. Voltage-clamp recordings further revealed that although excitatory inputs to complex and simple cells exhibited a similar degree of OS, inhibition in complex cells was more narrowly tuned than excitation, whereas in simple cells inhibition was more broadly tuned than excitation. The differential inhibitory tuning can primarily account for the difference in OS between complex and simple cells. Interestingly, the differential synaptic tuning correlated well with the spatial organization of synaptic input: the inhibitory visual RF in complex cells was more elongated in shape than its excitatory counterpart and also was more elongated than that in simple cells. Together, our results demonstrate that OS of complex and simple cells is differentially shaped by cortical inhibition based on its orientation tuning profile relative to excitation, which is contributed at least partially by the spatial organization of RFs of presynaptic inhibitory neurons. Simple and complex cells, two classes of principal neurons in the primary visual cortex (V1), are generally thought to be equally selective for orientation. In mouse V1, we report that complex cells, identified by their overlapping on/off subfields, has significantly weaker orientation selectivity (OS) than simple cells. This can be primarily attributed to the differential tuning selectivity of inhibitory synaptic input: inhibition in complex cells is more narrowly tuned than excitation, whereas in simple cells inhibition is more broadly tuned than excitation. In addition, there is a good correlation between inhibitory tuning selectivity and the spatial organization of inhibitory inputs. These complex and simple cells with differential degree of OS may provide functionally distinct signals to different downstream targets. Copyright © 2015 the authors 0270-6474/15/3511081-13$15.00/0.

A simple and rapid latex fixation test for measuring immunoglobulins produced in cell cultures.

PubMed

Kasahara, T; Harada, H; Enomoto, H; Itoh, Y; Kawai, T; Shioiri-Nakano, K

1981-01-01

A rapid and simple latex fixation test (LFT), which quantifies immunoglobulin (Ig) released into culture supernatants is described. Latex particles are coated with rabbit anti-human IgG, IgA or IgM antibodies. With this LFT technique the concentration of Ig is determined within a few minutes. The LFT is as sensitive and quantitative as double-antibody radioimmunoassay and is capable of detecting 35, 68 and 225 ng/ml of IgG, IgA and IgM, respectively.

The Invention Convention: Mind Meets Simple Machines.

ERIC Educational Resources Information Center

Hadi-Tabassum, Samina

1997-01-01

Describes an Earth Day celebration where students had to design an invention made of simple machines that could crush an empty aluminum can through 10 rapid mechanical movements using materials foraged from the students' homes. (JRH)

Validation of a rapid bacteria endospore enumeration system for use with spacecraft assembly

NASA Astrophysics Data System (ADS)

Chen, F.; Kuhlman, G.; Kirschner, L.; Kazarians, G.; Matsuyama, A.; Pickett, M.; Venkateswaran, K.; Kastner, J.; Kern, R.

NASA planetary protection policy sets forth strict limits on the number of bacterial endospores that can be present on a spacecraft at launch Currently the only approved method for counting the spores is a culture based assay that requires three days to produce results a timeframe that can be at odds with the rapid pace and rigorous deadlines of spacecraft assembly A possible alternative to the traditional culture based approach is the Millipore Rapid Microbiology Detection System RMDS which has previously been used for process and contamination control in the pharmaceutical and food industries The RMDS is rapid and simple shows high sensitivity 1 colony forming unit CFU sample and correlates well with traditional culture-based methods It combines membrane filtration adenosine triphosphate ATP bioluminescence chemistry and image analysis based on photon detection with a Charge Coupled Device CCD camera In this study we have optimized the assay condition and evaluated the use of the RMDS as a rapid spore detection tool for NASA applications Seven species of Bacillus nine strains that have been repeatedly isolated from clean room environments were assayed In order to select for spores the samples were subjected to a heat shock step before proceeding with the RMDS incubation protocol All strains were detected by the RMDS in sim 5 hours and these assay times were repeatedly demonstrated along with low image background noise The RMDS-based spore detection method is undergoing the final stages of validation and is

[Rapid fabrication of molecularly imprinted polymer fibers for solid phase microextraction of bisphenol A].

PubMed

Hu, Mei; Zhang, Yijun; Yang, Jinghua; Zhou, Xiaomao; Wei, Zhuqing; Ding, Xiaoqing; Zhang, Yuping

2015-02-01

The rapid preparation of molecularly imprinted polymer (MIP) fibers was reported using bisphenol A (BPA) as the template molecular, acetonitrile (ACN) as the porogenic solvent, α-methacrylic acid (MAA) as the functional monomer, ethylene dimethacrylate (EDMA) as the crosslinker, and azodiisobutyronitrile (AIBN) as the thermal initiator. It was carried out within a capillary of 530 µm inner diameter (I. D.) by microwave irradiation in 7 min. The resulted BPA-MIP fibers were pushed out from the capillary, eluted in a vial and inserted in the capillary again followed by the application of the solid phase microextraction (SPME) procedure. The extraction performance was investigated in detail by varying the molar ratios between the template and the monomer (BPA/MAA), the concentration of NaCl, the extraction and desorption time, the pH value and the desorption solvents. The selectivity of the prepared MIP and non-molecularly imprinted polymer (NIP) fibers was comparatively evaluated by selecting two structurally-related compounds, phenol (P) and 4-phenylphenol (PP), and non-analogue dicyandiamide (DCD). The established method was successfully applied for the pretreatment and determination of BPA from beverage samples coupled to high performance liquid chromatography (HPLC). Under the optimal conditions, the linear range of BPA was 10-400 µg/L; the detection limit (LOD) was 0.45 µg/L and the recoveries spiked in the mineral water were 88.4%-102. 8%. The results demonstrated that the developed method can determine BPA in real samples with some advantages of simple pretreatment, rapid analysis, low limit of detection and low consumption of materials.

A portable synthesis of water-soluble carbon dots for highly sensitive and selective detection of chlorogenic acid based on inner filter effect

NASA Astrophysics Data System (ADS)

Yang, Huan; Yang, Liu; Yuan, Yusheng; Pan, Shuang; Yang, Jidong; Yan, Jingjing; Zhang, Hui; Sun, Qianqian; Hu, Xiaoli

2018-01-01

In this work, a simple and facile hydrothermal method for synthesis of water-soluble carbon dots (CDs) with malic acid and urea, and were then employed as a high-performance fluorescent probe for selective and sensitive determination of chlorogenic acid (CGA) based on inner filter effect. The as-synthesized CDs was systematically characterized by Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Energy disperse spectroscopy (EDS), UV-vis absorption spectroscopy, spectrofluorophotometry, and the results indicated that the sizes of CDs were mainly distributed in the range of 1.0 nm-3.0 nm with an average diameter of 2.1 nm. More significantly, the as-prepared CDs possessed remarkable selectivity and sensitivity towards CGA with the linear range of 0.15 μmol L- 1-60 μmol L- 1 and the detection limit for CGA was 45 nmol L- 1 (3σ/k). The practical applications of CDs for detection of CGA have already been successfully demonstrated in Honeysuckle. This sensitive, selective method has a great application prospect in the pharmaceutical and biological analysis field owing to its simplicity and rapidity for the detection of CGA.

A nanoscale Zr-based fluorescent metal-organic framework for selective and sensitive detection of hydrogen sulfide

NASA Astrophysics Data System (ADS)

Li, Yanping; Zhang, Xin; Zhang, Ling; Jiang, Ke; Cui, Yuanjing; Yang, Yu; Qian, Guodong

2017-11-01

Hydrogen sulfide (H2S) has been commonly viewed as a gas signaling molecule in various physiological and pathological processes. However, the highly efficient H2S detection still remains challenging. Herein, we designed a new robust nano metal-organic framework (MOF) UiO-66-CH=CH2 as a fluorescent probe for rapid, sensitive and selective detection of biological H2S. UiO-66-CH=CH2 was prepared by heating ZrCl4 and 2-vinylterephthalic acid via a simple method. UiO-66-CH=CH2 displayed fluorescence quenching to H2S and kept excellent selectivity in the presence of biological relevant analytes especially the cysteine and glutathione. This MOF-based probe also exhibited fast response (10 s) and high sensitivity with a detection limit of 6.46 μM which was within the concentration range of biological H2S in living system. Moreover, this constructed MOF featured water-stability, nanoscale (20-30 nm) and low toxicity, which made it a promising candidate for biological H2S sensing.

Fluorescence detection of trace PCB101 based on PITC immobilized on porous AAO membrane.

PubMed

Wang, Meiling; Meng, Guowen; Huang, Qing; Li, Mingtao; Li, Zhongbo; Tang, Chaolong

2011-01-21

A sensitive and selective fluorescent membrane for rapid detection of trace 2,2',4,5,5'-pentachlorinated biphenyl (PCB101) has been achieved by immobilizing the fluorophore phenyl isothiocyanate (PITC) onto porous anodic aluminium oxide (AAO) membrane (denoted as PITC@AAO). The fluorescence of the PITC@AAO membrane is obviously enhanced after titrating the analyte PCB101 into the membrane, being ascribed to the halogen-bonding interaction between the fluorophore PITC and the analyte PCB101. The fluorescence intensity increases with the PCB101 concentration in the low range below 1 ppm, and there exists an approximate linear relationship between the relative fluorescence intensity and the PCB101 concentration in the low range of 1-6 ppb. Moreover, the PITC@AAO membrane shows good selectivity; for example, it is insensitive to common structural analogs (polychlorinated aromatics). The mechanisms of the fluorescence enhancement and the better sensitivity and selectivity of the PITC@AAO membrane to PCB101 than that of PITC/n-hexane solution are also discussed. This work demonstrates that trace (in ppb range) PCBs can be detected by simple fluorescence measurement.

Succinic acid functionalized silver nanoparticles (Suc-Ag NPs) for colorimetric sensing of melamine

NASA Astrophysics Data System (ADS)

Rajar, Kausar; Sirajuddin; Balouch, Aamna; Bhanger, M. I.; Shah, Muhammad Tariq; Shaikh, Tayyaba; Siddiqui, Samia

2018-03-01

In this study, a quantitative colorimetric sensing strategy is developed for the rapid, sensitive and selective determination of melamine. The sensing system relies on the application of succinic acid as a selective recognition probe functionalized over Ag NPs. The synthesized Ag NPs were modified with cysteamine to induce positively charged atmosphere which allowed easy and favorable functionalization of succinic acid. The di-carboxyl nature of succinic acid enabled its binding to both cysteamine and melamine. The strong and favorable linkage between succinic acids carbonyl and amine moieties of melamine triggered aggregation of silver NPs producing a significant shift in the measured absorption excitation. This change in the excitation along with the colorimetric response was found linearly proportional to the melamine concentration in the range of 0.1-1.2 μM. The developed sensor system is simple and unlike electrostatic attraction based sensor system utilize selective linkage for the recognition of melamine. In addition to this, the developed optical probe can efficiently be used for the determination of melamine in milk samples.

Preparation and evaluation of magnetic core-shell mesoporous molecularly imprinted polymers for selective adsorption of tetrabromobisphenol S.

PubMed

Wang, Xuemei; Huang, Pengfei; Ma, Xiaomin; Wang, Huan; Lu, Xiaoquan; Du, Xinzhen

2017-05-01

Novel magnetic mesoporous molecularly imprinted polymers (MMIPs) with core-shell structure were prepared by simple surface molecular imprinting polymerization using tetrabromobisphenol-S (TBBPS) as the template. The MMIPs-TBBPS were characterized by fourier-transform infrared spectrometry (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 adsorption-desorption transmission, and vibrating sample magnetometry. The resultant MMIPs-TBBPS were successfully applied magnetic solid-phase extraction (MSPE) coupled with HPLC determination of TBBPS in spiked real water samples with recoveries of 77.8-88.9%. The adsorption experiments showed that the binding capacity of MMIPs-TBBPS to TBBPS and six structural analogs were significantly higher than that of the magnetic nonimprinted polymers (MNIPs). Meanwhile, the MMIPs-TBBPS possessed rapid binding affinity, excellent magnetic response, specific selectivity and high adsorption capacity toward TBBPS with a maximum adsorption capacity of 1626.8µgg -1 . The analytical results indicate that the MMIPs-TBBPS are promising materials for selective separation and fast enrichment of TBBPS from complicated enviromental samples. Copyright © 2017 Elsevier B.V. All rights reserved.

A highly sensitive and selective aptamer-based colorimetric sensor for the rapid detection of PCB 77.

PubMed

Cheng, Ruojie; Liu, Siyao; Shi, Huijie; Zhao, Guohua

2018-01-05

A highly sensitive, specific and simple colorimetric sensor based on aptamer was established for the detection of polychlorinated biphenyls (PCB 77). The use of unmodified gold nanoparticles as a colorimetric probe for aptamer sensors enabled the highly sensitive and selective detection of polychlorinated biphenyls (PCB 77). A linear range of 0.5nM to 900nM was obtained for the colorimetric assay with a minimum detection limit of 0.05nM. In addition, by the methods of circular dichroism, UV and naked eyes, we found that the 35 base fragments retained after cutting 5 bases from the 5 'end of aptamer plays the most significant role in the PCB 77 specific recognition process. We found a novel way to truncated nucleotides to optimize the detection of PCB 77, and the selected nucleotides also could achieve high affinity with PCB 77. At the same time, the efficient detection of the PCB 77 by our colorimetric sensor in the complex environmental water samples was realized, which shows a good application prospect. Copyright © 2017 Elsevier B.V. All rights reserved.

Rapid and selective lead (II) colorimetric sensor based on azacrown ether-functionalized gold nanoparticles

NASA Astrophysics Data System (ADS)

Alizadeh, A.; Khodaei, M. M.; Karami, Ch; Workentin, M. S.; Shamsipur, M.; Sadeghi, M.

2010-08-01

A gold nanoparticle (AuNPs)-based simple and fast colorimetric sensor for selective detecting of Pb(II) in aqueous solution has been developed. Monodisperse AuNPs (approx. 2.0 nm diameter) has been prepared facilely and further modified with an alkanethiol-bearing monoazacrown ether terminus. These AuNPs are shown to selectively sense Pb2 + through color change, which is visually discernible by an appearance of the surface plasmon band (SPB) at 520 nm. The recognition mechanism is attributed to the unique structure of the monoazacrown ether attached to AuNPs and metal sandwich coordination between two azacrown ether moieties that are attached to separate nanoparticles. This inter-particle cross-linking results in an aggregation and apparent color change from brown to purple. Additionally, TEM experiments support the optical absorption data proving the aggregation between azacrown ether-capped gold nanoparticles. This AuNP-based colorimetric assay is a facile and robust method and allows fast detection of Pb2 + at ambient temperatures. More importantly, the developed technique does not utilize enzymatic reactions, light-sensitive dye molecules, lengthy protocols or sophisticated instrumentation.

Rapid immunochromatographic diagnosis and Rolling Back Malaria--experiences from an African control program.

PubMed

Durrheim, D N; Govere, J; la Grange, J J; Mabuza, A

2001-01-01

Malaria is a re-emerging disease in much of Africa. In response, the World Health Organization launched the Roll Back Malaria (RBM) initiative. One of six key principles adopted is the early detection of malaria cases. However, the importance of definitive diagnosis and potential value of field deployment of rapid malaria tests in RBM has been largely ignored. The Lowveld Region of Mpumalanga Province, South Africa, is home to a predominantly non-immune population, of approximately 850000 inhabitants, who are at risk of seasonal Plasmodium falciparum malaria. Malaria treatment in this area is usually only initiated on detection of malaria parasites in the peripheral bloodstream, as many other rickettsial and viral febrile illness mimic malaria. The malaria control programme traditionally relied on light microscopy of Giemsa-stained thick blood films for malaria diagnosis. This review summarizes operational research findings that led to the introduction of rapid malaria card tests for primary diagnosis of malaria throughout the Mpumalanga malaria area. Subsequent operational research and extensive experience over a four-year period since introducing the ICT Malaria Pf test appears to confirm the local appropriateness of this diagnostic modality. A laboratory is not required and clinic staff are empowered to make a prompt definitive diagnosis, limiting delays in initiating correct therapy. The simple, accurate and rapid non-microscopic means now available for diagnosing malaria could play an important role in Rolling Back Malaria in selected areas.

Validation and Application of a Simple UHPLC-MS-MS Method for the Enantiospecific Determination of Warfarin in Human Urine.

PubMed

Alshogran, Osama Y; Ocque, Andrew J; Leblond, François A; Pichette, Vincent; Nolin, Thomas D

2016-04-01

A simple and rapid liquid chromatographic-tandem mass spectrometric method has been developed and validated for the enantiospecific determination of R- and S-warfarin in human urine. Warfarin enantiomers were extracted from urine using methyl tert-butyl ether. Chromatographic separation of warfarin enantiomers and the internal standard d5-warfarin was achieved using a Astec Chirobiotic V column with gradient mobile phase at a flow rate of 400 µL/min over 10 min. Detection was performed on a TSQ Quantum Ultra triple quadrupole mass spectrometer equipped with a heated electrospray ionization source. Analytes were detected in negative ionization mode using selected reaction monitoring. Calibration curves were linear with a correlation coefficient of ≥0.996 for both enantiomers over a concentration range of 5-500 ng/mL. The intra- and interday accuracy and precision for both analytes were within ±9.0%. Excellent extraction efficiency and negligible matrix effects were observed. The applicability of the method was demonstrated by successful measurement of warfarin enantiomers in urine of patients with kidney disease. The method is simple, accurate and reproducible and is currently being used to support warfarin pharmacokinetic studies. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Quantification of endocytosis using a folate functionalized silica hollow nanoshell platform

PubMed Central

Sandoval, Sergio; Mendez, Natalie; Alfaro, Jesus G.; Yang, Jian; Aschemeyer, Sharraya; Liberman, Alex; Trogler, William C.; Kummel, Andrew C.

2015-01-01

Abstract. A quantification method to measure endocytosis was designed to assess cellular uptake and specificity of a targeting nanoparticle platform. A simple N-hydroxysuccinimide ester conjugation technique to functionalize 100-nm hollow silica nanoshell particles with fluorescent reporter fluorescein isothiocyanate and folate or polyethylene glycol (PEG) was developed. Functionalized nanoshells were characterized using scanning electron microscopy and transmission electron microscopy and the maximum amount of folate functionalized on nanoshell surfaces was quantified with UV-Vis spectroscopy. The extent of endocytosis by HeLa cervical cancer cells and human foreskin fibroblast (HFF-1) cells was investigated in vitro using fluorescence and confocal microscopy. A simple fluorescence ratio analysis was developed to quantify endocytosis versus surface adhesion. Nanoshells functionalized with folate showed enhanced endocytosis by cancer cells when compared to PEG functionalized nanoshells. Fluorescence ratio analyses showed that 95% of folate functionalized silica nanoshells which adhered to cancer cells were endocytosed, while only 27% of PEG functionalized nanoshells adhered to the cell surface and underwent endocytosis when functionalized with 200 and 900  μg, respectively. Additionally, the endocytosis of folate functionalized nanoshells proved to be cancer cell selective while sparing normal cells. The developed fluorescence ratio analysis is a simple and rapid verification/validation method to quantify cellular uptake between datasets by using an internal control for normalization. PMID:26315280

Autonomously Self-Adhesive Hydrogels as Building Blocks for Additive Manufacturing.

PubMed

Deng, Xudong; Attalla, Rana; Sadowski, Lukas P; Chen, Mengsu; Majcher, Michael J; Urosev, Ivan; Yin, Da-Chuan; Selvaganapathy, P Ravi; Filipe, Carlos D M; Hoare, Todd

2018-01-08

We report a simple method of preparing autonomous and rapid self-adhesive hydrogels and their use as building blocks for additive manufacturing of functional tissue scaffolds. Dynamic cross-linking between 2-aminophenylboronic acid-functionalized hyaluronic acid and poly(vinyl alcohol) yields hydrogels that recover their mechanical integrity within 1 min after cutting or shear under both neutral and acidic pH conditions. Incorporation of this hydrogel in an interpenetrating calcium-alginate network results in an interfacially stiffer but still rapidly self-adhesive hydrogel that can be assembled into hollow perfusion channels by simple contact additive manufacturing within minutes. Such channels withstand fluid perfusion while retaining their dimensions and support endothelial cell growth and proliferation, providing a simple and modular route to produce customized cell scaffolds.

Label-free SPR detection of gluten peptides in urine for non-invasive celiac disease follow-up.

PubMed

Soler, Maria; Estevez, M-Carmen; Moreno, Maria de Lourdes; Cebolla, Angel; Lechuga, Laura M

2016-05-15

Motivated by the necessity of new and efficient methods for dietary gluten control of celiac patients, we have developed a simple and highly sensitive SPR biosensor for the detection of gluten peptides in urine. The sensing methodology enables rapid and label-free quantification of the gluten immunogenic peptides (GIP) by using G12 mAb. The overall performance of the biosensor has been in-depth optimized and evaluated in terms of sensitivity, selectivity and reproducibility, reaching a limit of detection of 0.33 ng mL(-1). Besides, the robustness and stability of the methodology permit the continuous use of the biosensor for more than 100 cycles with excellent repeatability. Special efforts have been focused on preventing and minimizing possible interferences coming from urine matrix enabling a direct analysis in this fluid without requiring extraction or purification procedures. Our SPR biosensor has proven to detect and identify gluten consumption by evaluating urine samples from healthy and celiac individuals with different dietary gluten conditions. This novel biosensor methodology represents a novel approach to quantify the digested gluten peptides in human urine with outstanding sensitivity in a rapid and non-invasive manner. Our technique should be considered as a promising opportunity to develop Point-of-Care (POC) devices for an efficient, simple and accurate gluten free diet (GFD) monitoring as well as therapy follow-up of celiac disease patients. Copyright © 2015 Elsevier B.V. All rights reserved.

Rapid microwave assisted synthesis of graphene nanosheets/polyethyleneimine/gold nanoparticle composite and its application to the selective electrochemical determination of dopamine.

PubMed

Ponnusamy, Vinoth Kumar; Mani, Veerappan; Chen, Shen-Ming; Huang, Wan-Tran; Jen, Jen-Fon

2014-03-01

In this study, a simple and fast microwave assisted chemical reduction method for the preparation of graphene nanosheet/polyethyleneimine/gold nanoparticle (GNS/PEI/AuNP) composite was developed. PEI, a cationic polymer, was used both as a non-covalent functionalizing agent for the graphene oxide nanosheets (GONSs) through electrostatic interactions in the aqueous medium and also as a stabilizing agent for the formation of AuNPs on PEI wrapped GNSs. This preparation method involves a simple mixing step followed by a simultaneous microwave assisted chemical reduction of the GONSs and gold ions. The prepared composite exhibits the dispersion of high density AuNPs which were densely decorated on the large surface area of the PEI wrapped GNS. X-ray photoelectron spectroscopy, powder X-ray diffraction, high-resolution transmission electron microscopy, field-emission scanning electron microscopy with energy dispersive X-ray spectroscopy, and thermo-gravimetric analysis, were used to characterize the properties of the resultant composite. The prepared GNS/PEI/AuNP composite film exhibited excellent electrocatalytical activity towards the selective determination of dopamine in the presence of ascorbic acid, which showed potential application in electrochemical sensors. The applicability of the presented sensor was also demonstrated for the determination of dopamine in human urine samples. © 2013 Elsevier B.V. All rights reserved.

A simple and rapid Hepatitis A Virus (HAV) titration assay based on antibiotic resistance of infected cells: evaluation of the HAV neutralization potency of human immune globulin preparations

PubMed Central

Konduru, Krishnamurthy; Virata-Theimer, Maria Luisa; Yu, Mei-ying W; Kaplan, Gerardo G

2008-01-01

Background Hepatitis A virus (HAV), the causative agent of acute hepatitis in humans, is an atypical Picornaviridae that grows poorly in cell culture. HAV titrations are laborious and time-consuming because the virus in general does not cause cytopathic effect and is detected by immunochemical or molecular probes. Simple HAV titration assays could be developed using currently available viral construct containing selectable markers. Results We developed an antibiotic resistance titration assay (ARTA) based on the infection of human hepatoma cells with a wild type HAV construct containing a blasticidin (Bsd) resistance gene. Human hepatoma cells infected with the HAV-Bsd construct survived selection with 2 μg/ml of blasticidin whereas uninfected cells died within a few days. At 8 days postinfection, the color of the pH indicator phenol red in cell culture media correlated with the presence of HAV-Bsd-infected blasticidin-resistant cells: an orange-to-yellow color indicated the presence of growing cells whereas a pink-to-purple color indicated that the cells were dead. HAV-Bsd titers were determined by an endpoint dilution assay based on the color of the cell culture medium scoring orange-to-yellow wells as positive and pink-to-purple wells as negative for HAV. As a proof-of-concept, we used the ARTA to evaluate the HAV neutralization potency of two commercially available human immune globulin (IG) preparations and a WHO International Standard for anti-HAV. The three IG preparations contained comparable levels of anti-HAV antibodies that neutralized approximately 1.5 log of HAV-Bsd. Similar neutralization results were obtained in the absence of blasticidin by an endpoint dilution ELISA at 2 weeks postinfection. Conclusion The ARTA is a simple and rapid method to determine HAV titers without using HAV-specific probes. We determined the HAV neutralization potency of human IG preparations in 8 days by ARTA compared to the 14 days required by the endpoint dilution ELISA. The ARTA reduced the labour, time, and cost of HAV titrations making it suitable for high throughput screening of sera and antivirals, determination of anti-HAV antibodies in human immune globulin preparations, and research applications that involve the routine evaluation of HAV titers. PMID:19094229

Toward a Rapid Synthesis of Field and Desktop Data for Classifying Streams in the Pacific Northwest: Guiding the Sampling and Management of Salmonid Habitat

NASA Astrophysics Data System (ADS)

Kasprak, A.; Wheaton, J. M.; Bouwes, N.; Weber, N. P.; Trahan, N. C.; Jordan, C. E.

2012-12-01

River managers often seek to understand habitat availability and quality for riverine organisms within the physical template provided by their landscape. Yet the large amount of natural heterogeneity in landscapes gives rise to stream systems which are highly variable over small spatial scales, potentially complicating site selection for surveying aquatic habitat while simultaneously making a simple, wide-reaching management strategy elusive. This is particularly true in the rugged John Day River Basin of northern Oregon, where efforts as part of the Columbia Habitat Monitoring Program to conduct site-based surveys of physical habitat for endangered steelhead salmon (Oncorhynchus mykiss) are underway. As a complete understanding of the type and distribution of habitat available to these fish would require visits to all streams in the basin (impractical due to its large size), here we develop an approach for classifying channel types which combines remote desktop GIS analyses with rapid field-based stream and landscape surveys. At the core of this method, we build off of the River Styles Framework, an open-ended and process-based approach for classifying streams and informing management decisions. This framework is combined with on-the-ground fluvial audits, which aim to quickly and continuously map sediment dynamics and channel behavior along selected channels. Validation of this classification method is completed by on-the-ground stream surveys using a digital iPad platform and by rapid small aircraft overflights to confirm or refine predictions. We further compare this method with existing channel classification approaches for the region (e.g. Beechie, Montgomery and Buffington). The results of this study will help guide both the refinement of site stratification and selection for salmonid habitat monitoring within the basin, and will be vital in designing and prioritizing restoration and management strategies tailored to the distribution of river styles found across the region.

Microscale Organic Laboratory: IV. A Simple and Rapid Procedure for Carrying Out Wittig Reactions.

ERIC Educational Resources Information Center

Pike, R. M.; And Others

1986-01-01

Describes two examples where synthetic salt-base mixtures are used in a microscale organic laboratory program as a simple and quick procedure for carrying out Wittig reactions. Both experimental procedures are outlined and discussed. (TW)

Beyond the single gene: How epistasis and gene-by-environment effects influence crop domestication.

PubMed

Doust, Andrew N; Lukens, Lewis; Olsen, Kenneth M; Mauro-Herrera, Margarita; Meyer, Ann; Rogers, Kimberly

2014-04-29

Domestication is a multifaceted evolutionary process, involving changes in individual genes, genetic interactions, and emergent phenotypes. There has been extensive discussion of the phenotypic characteristics of plant domestication, and recent research has started to identify the specific genes and mutational mechanisms that control domestication traits. However, there is an apparent disconnect between the simple genetic architecture described for many crop domestication traits, which should facilitate rapid phenotypic change under selection, and the slow rate of change reported from the archeobotanical record. A possible explanation involves the middle ground between individual genetic changes and their expression during development, where gene-by-gene (epistatic) and gene-by-environment interactions can modify the expression of phenotypes and opportunities for selection. These aspects of genetic architecture have the potential to significantly slow the speed of phenotypic evolution during crop domestication and improvement. Here we examine whether epistatic and gene-by-environment interactions have shaped how domestication traits have evolved. We review available evidence from the literature, and we analyze two domestication-related traits, shattering and flowering time, in a mapping population derived from a cross between domesticated foxtail millet and its wild progenitor. We find that compared with wild progenitor alleles, those favored during domestication often have large phenotypic effects and are relatively insensitive to genetic background and environmental effects. Consistent selection should thus be able to rapidly change traits during domestication. We conclude that if phenotypic evolution was slow during crop domestication, this is more likely due to cultural or historical factors than epistatic or environmental constraints.

Surface plasmon resonance based selective and sensitive colorimetric determination of azithromycin using unmodified silver nanoparticles in pharmaceuticals and human plasma

NASA Astrophysics Data System (ADS)

Chavada, Vijay D.; Bhatt, Nejal M.; Sanyal, Mallika; Shrivastav, Pranav S.

2017-01-01

In this article we report a novel method for colorimetric sensing and selective determination of a non-chromophoric drug-azithromycin, which lacks native absorbance in the UV-Visible region using unmodified silver nanoparticles (AgNPs). The citrate-capped AgNps dispersed in water afforded a bright yellow colour owing to the electrostatic repulsion between the particles due to the presence of negatively charged surface and showed surface plasmon resonance (SPR) band at 394 nm. Addition of positively charged azithromycin at a concentration as low as 0.2 μM induced rapid aggregation of AgNPs by neutralizing the negative charge on the particle surface. This phenomenon resulted in the colour change from bright yellow to purple which could be easily observed by the naked eye. This provided a simple platform for rapid determination of azithromycin based on colorimetric measurements. The factors affecting the colorimetric response like pH, volume of AgNPs suspension and incubation time were suitably optimized. The validated method was found to work efficiently in the established concentration range of 0.2-100.0 μM using two different calibration models. The selectivity of the method was also evaluated by analysis of nanoparticles-aggregation response upon addition of several anions, cations and some commonly prescribed antibiotics. The method was successfully applied for the analysis of azithromycin in pharmaceuticals and spiked human plasma samples with good accuracy and precision. The simplicity, efficiency and cost-effectiveness of the method hold tremendous potential for the analysis of such non-chromophoric pharmaceuticals.

Rapid detection of bacteria in foods and biological fluids

NASA Technical Reports Server (NTRS)

Fealey, R. D.; Renner, W.

1973-01-01

Simple and inexpensive apparatus, called "redox monitoring cell," rapidly detects presence of bacteria. Bacteria is detected by measuring drop in oxygen content in test solution. Apparatus consists of vial with two specially designed electrodes connected to sensitive voltmeter.

Selected computations of transonic cavity flows

NASA Technical Reports Server (NTRS)

Atwood, Christopher A.

1993-01-01

An efficient diagonal scheme implemented in an overset mesh framework has permitted the analysis of geometrically complex cavity flows via the Reynolds averaged Navier-Stokes equations. Use of rapid hyperbolic and algebraic grid methods has allowed simple specification of critical turbulent regions with an algebraic turbulence model. Comparisons between numerical and experimental results are made in two dimensions for the following problems: a backward-facing step; a resonating cavity; and two quieted cavity configurations. In three-dimensions the flow about three early concepts of the stratospheric Observatory For Infrared Astronomy (SOFIA) are compared to wind-tunnel data. Shedding frequencies of resolved shear layer structures are compared against experiment for the quieted cavities. The results demonstrate the progress of computational assessment of configuration safety and performance.

[Studies on the interaction between RNA with neutral red and determination of RNA by spectrophotometry].

PubMed

Si, Wen-Hui

2007-06-01

An analytical method for the determination of ribonucleic acid by spectrophotometry was established. At the maximum absorption wavelength for neutral red in B-R buffer solution, and under the best conditions, the decrease in the absorbance was linear with the amount of ribonucleic acid. The linearity range was 0.0-9.0 microg x mL(-1), the detection limit was 0.52 microg x mL(-1), and the correlation coeffient was 0.999 8. This method was simple, rapid, and selective. So its application to the determination of ribonucleic acid was satisfactory. The reaction mechanism was that the electrostatic interaction leads to molecular association of RNA with neutral red, resulting in anti-ion permutation and bonding reaction.

Rapid trifluoromethylation and perfluoroalkylation of five-membered heterocycles by photoredox catalysis in continuous flow.

PubMed

Straathof, Natan J W; Gemoets, Hannes P L; Wang, Xiao; Schouten, Jaap C; Hessel, Volker; Noël, Timothy

2014-06-01

Trifluoromethylated and perfluoroalkylated heterocycles are important building blocks for the synthesis of numerous pharmaceutical products, agrochemicals and are widely applied in material sciences. To date, trifluoromethylated and perfluoroalkylated hetero-aromatic systems can be prepared utilizing visible light photoredox catalysis methodologies in batch. While several limitations are associated with these batch protocols, the application of microflow technology could greatly enhance and intensify these reactions. A simple and straightforward photocatalytic trifluoromethylation and perfluoroalkylation method has been developed in continuous microflow, using commercially available photocatalysts and microflow components. A selection of five-membered hetero-aromatics were successfully trifluoromethylated (12 examples) and perfluoroalkylated (5 examples) within several minutes (8-20 min). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Identification of important image features for pork and turkey ham classification using colour and wavelet texture features and genetic selection.

PubMed

Jackman, Patrick; Sun, Da-Wen; Allen, Paul; Valous, Nektarios A; Mendoza, Fernando; Ward, Paddy

2010-04-01

A method to discriminate between various grades of pork and turkey ham was developed using colour and wavelet texture features. Image analysis methods originally developed for predicting the palatability of beef were applied to rapidly identify the ham grade. With high quality digital images of 50-94 slices per ham it was possible to identify the greyscale that best expressed the differences between the various ham grades. The best 10 discriminating image features were then found with a genetic algorithm. Using the best 10 image features, simple linear discriminant analysis models produced 100% correct classifications for both pork and turkey on both calibration and validation sets. 2009 Elsevier Ltd. All rights reserved.

The anticancer agent 3-bromopyruvate: a simple but powerful molecule taken from the lab to the bedside.

PubMed

Azevedo-Silva, J; Queirós, O; Baltazar, F; Ułaszewski, S; Goffeau, A; Ko, Y H; Pedersen, P L; Preto, A; Casal, M

2016-08-01

At the beginning of the twenty-first century, 3-bromopyruvate (3BP), a simple alkylating chemical compound was presented to the scientific community as a potent anticancer agent, able to cause rapid toxicity to cancer cells without bystander effects on normal tissues. The altered metabolism of cancers, an essential hallmark for their progression, also became their Achilles heel by facilitating 3BP's selective entry and specific targeting. Treatment with 3BP has been administered in several cancer type models both in vitro and in vivo, either alone or in combination with other anticancer therapeutic approaches. These studies clearly demonstrate 3BP's broad action against multiple cancer types. Clinical trials using 3BP are needed to further support its anticancer efficacy against multiple cancer types thus making it available to more than 30 million patients living with cancer worldwide. This review discusses current knowledge about 3BP related to cancer and discusses also the possibility of its use in future clinical applications as it relates to safety and treatment issues.

The Use of Partial Least Square Regression and Spectral Data in UV-Visible Region for Quantification of Adulteration in Indonesian Palm Civet Coffee

PubMed Central

Yulia, Meinilwita

2017-01-01

Asian palm civet coffee or kopi luwak (Indonesian words for coffee and palm civet) is well known as the world's priciest and rarest coffee. To protect the authenticity of luwak coffee and protect consumer from luwak coffee adulteration, it is very important to develop a robust and simple method for determining the adulteration of luwak coffee. In this research, the use of UV-Visible spectra combined with PLSR was evaluated to establish rapid and simple methods for quantification of adulteration in luwak-arabica coffee blend. Several preprocessing methods were tested and the results show that most of the preprocessing spectra were effective in improving the quality of calibration models with the best PLS calibration model selected for Savitzky-Golay smoothing spectra which had the lowest RMSECV (0.039) and highest RPDcal value (4.64). Using this PLS model, a prediction for quantification of luwak content was calculated and resulted in satisfactory prediction performance with high both RPDp and RER values. PMID:28913348

A Simple Assay for Ultrasensitive Colorimetric Detection of Ag⁺ at Picomolar Levels Using Platinum Nanoparticles.

PubMed

Wang, Yi-Wei; Wang, Meili; Wang, Lixing; Xu, Hui; Tang, Shurong; Yang, Huang-Hao; Zhang, Lan; Song, Hongbo

2017-11-02

In this work, uniformly-dispersed platinum nanoparticles (PtNPs) were synthesized by a simple chemical reduction method, in which citric acid and sodium borohydride acted as a stabilizer and reducer, respectively. An ultrasensitive colorimetric sensor for the facile and rapid detection of Ag⁺ ions was constructed based on the peroxidase mimetic activities of the obtained PtNPs, which can catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) by H₂O₂ to produce colored products. The introduced Ag⁺ would be reduced to Ag⁰ by the capped citric acid, and the deposition of Ag⁰ on the PtNPs surface, can effectively inhibit the peroxidase-mimetic activity of PtNPs. Through measuring the maximum absorption signal of oxidized TMB at 652 nm, ultra-low detection limits (7.8 pM) of Ag⁺ can be reached. In addition to such high sensitivity, the colorimetric assay also displays excellent selectivity for other ions of interest and shows great potential for the detection of Ag⁺ in real water samples.

Hydrophobic to superhydrophobic surface modification using impacting particulate sprays

NASA Astrophysics Data System (ADS)

Lau, Chun Yat; Vuong, Thach; Wang, Jingming; Muradoglu, Murat; Liew, Oi Wah; Ng, Tuck Wah

2014-08-01

The roughening or structuring of inherently hydrophobic surfaces to possess microscopic and nanoscopic features can transform them to exhibit superhydrophobicity. The use of impacting particulate sprays here eschews specialized reagents and equipments; is simple, inexpensive, and rapid to implement; creates highly repeatable outcomes; and permits selective region transformation via simple masking. With PTFE, the contact angle transforms from 90° to 150°, in which SEM examination reveals erosive wear mechanisms that are dependent on the impingement angle. The process tends to cause the sample to bulge upwards from the treated surface due to elongation there, and can be mitigated by using lower impingement angles in the particulate spray. A finite element model created enables this characteristic to be related to the action of locked-in surface traction forces. The use of adhesive bonding to a rigid base is shown to be an alternative method to reduce the bulging. A second finite model developed allows knowledge of the right adhesive needed for this. In developing substrates for biochemical analysis, the approach offers very small possibilities for unintended synergistic interactions.

Access to the meta position of arenes through transition metal catalysed C-H bond functionalisation: a focus on metals other than palladium.

PubMed

Mihai, Madalina T; Genov, Georgi R; Phipps, Robert J

2018-01-02

The elaboration of simple arenes in order to access more complex substitution patterns is a crucial endeavor for synthetic chemists, given the central role that aromatic rings play in all manner of important molecules. Classical methods are now routinely used alongside stoichiometric organometallic approaches and, most recently, transition metal catalysis in the range of methodologies that are available to elaborate arene C-H bonds. Regioselectivity is an important consideration when selecting a method and, of all those available, it is arguably those that target the meta position that are fewest in number. The rapid development of transition metal-catalysed C-H bond functionalisation over the last few decades has opened new possibilities for meta-selective C-H functionalisation through the diverse reactivity of transition metals and their compatibility with a wide range of directing groups. The pace of discovery of such processes has grown rapidly in the last five years in particular and it is the purpose of this review to examine these but in doing so to place the focus on metals other than palladium, the specific contributions of which have been very recently reviewed elsewhere. It is hoped this will serve to highlight to the reader the breadth of current strategies and mechanisms that have been used to tackle this challenge, which may inspire further progress in the field.

Rapid pretreatment and determination of bisphenol A in water samples based on vortex-assisted liquid-liquid microextraction followed by high-performance liquid chromatography with fluorescence detection.

PubMed

Yang, Xiao; Diao, Chun-Peng; Sun, Ai-Ling; Liu, Ren-Min

2014-10-01

A method for the rapid pretreatment and determination of bisphenol A in water samples based on vortex-assisted liquid-liquid microextraction followed by high-performance liquid chromatography with fluorescence detection was proposed in this paper. A simple apparatus consisting of a test tube and a cut-glass dropper was designed and applied to collect the floating extraction drop in liquid-liquid microextraction when low-density organic solvent was used as the extraction solvent. Solidification and melting steps that were tedious but necessary once the low-density organic solvent used as extraction solvent could be avoided by using this apparatus. Bisphenol A was selected as model pollutant and vortex-assisted liquid-liquid microextraction was employed to investigate the usefulness of the apparatus. High-performance liquid chromatography with fluorescence detection was selected as the analytical tool for the detection of bisphenol A. The linear dynamic range was from 0.10 to 100 μg/L for bisphenol A, with good squared regression coefficient (r(2) = 0.9990). The relative standard deviation (n = 7) was 4.7% and the limit of detection was 0.02 μg/L. The proposed method had been applied to the determination of bisphenol A in natural water samples and was shown to be economical, fast, and convenient. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fabrication of enzyme-immobilized halloysite nanotubes for affinity enrichment of lipase inhibitors from complex mixtures.

PubMed

Wang, Haibo; Zhao, Xiaoping; Wang, Shufang; Tao, Shan; Ai, Ni; Wang, Yi

2015-05-01

Lipase is the key enzyme for catalyzing triglyceride hydrolysis in vivo, and lipase inhibitors have been used in the management of obesity. We present the first report on the use of lipase-adsorbed halloysite nanotubes as an efficient medium for the selective enrichment of lipase inhibitors from natural products. A simple and rapid approach was proposed to fabricate lipase-adsorbed nanotubes through electrostatic interaction. Results showed that more than 85% lipase was adsorbed into nanotubes in 90 min, and approximately 80% of the catalytic activity was maintained compared with free lipase. The specificity and reproducibility of the proposed approach were validated by screening a known lipase inhibitor (i.e., orlistat) from a mixture that contains active and inactive compounds. Moreover, we applied this approach with high performance liquid chromatography-mass spectrometry technique to screen lipase inhibitors from the Magnoliae cortex extract, a medicinal plant used for treating obesity. Two novel biphenyl-type natural lipase inhibitors magnotriol A and magnaldehyde B were identified, and their IC50 values were determined as 213.03 and 96.96 μM, respectively. The ligand-enzyme interactions of magnaldehyde B were further investigated by molecular docking. Our findings proved that enzyme-adsorbed nanotube could be used as a feasible and selective affinity medium for the rapid screening of enzyme inhibitors from complex mixtures. Copyright © 2015 Elsevier B.V. All rights reserved.

Ethanol chemiresistor with enhanced discriminative ability from acetone based on Sr-doped SnO2 nanofibers.

PubMed

Jiang, Ziqiao; Jiang, Tingting; Wang, Jinfeng; Wang, Zhaojie; Xu, Xiuru; Wang, Zongxin; Zhao, Rui; Li, Zhenyu; Wang, Ce

2015-01-01

We demonstrated a new metal oxides based chemiresistor (MOC), which exhibits fast response/recovery behavior, large sensitivity, and good selectivity to ethanol, enabled by Sr-doped SnO2 nanofibers via simple electrospinning and followed by calcination. Transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectra (XPS) were carefully used to characterize their morphology, structure, and composition. The ethanol sensing performances based on Sr-doped SnO2 nanofibers were investigated. Comparing with the pristine SnO2 nanofibers, enhanced ethanol sensing performances (more rapid response/recovery behavior and larger response values) have been achieved owing to the basic SnO2 surface caused by Sr-doping, whereas the acetone sensing performances have been weakened. Thus, good discriminative ability to ethanol from acetone has been realized. Additionally, Sr-doped SnO2 nanofibers also exhibit good selectivity. Copyright © 2014 Elsevier Inc. All rights reserved.

Sensitive analytical method for simultaneous analysis of some vasoconstrictors with highly overlapped analytical signals

NASA Astrophysics Data System (ADS)

Nikolić, G. S.; Žerajić, S.; Cakić, M.

2011-10-01

Multivariate calibration method is a powerful mathematical tool that can be applied in analytical chemistry when the analytical signals are highly overlapped. The method with regression by partial least squares is proposed for the simultaneous spectrophotometric determination of adrenergic vasoconstrictors in decongestive solution containing two active components: phenyleprine hydrochloride and trimazoline hydrochloride. These sympathomimetic agents are that frequently associated in pharmaceutical formulations against the common cold. The proposed method, which is, simple and rapid, offers the advantages of sensitivity and wide range of determinations without the need for extraction of the vasoconstrictors. In order to minimize the optimal factors necessary to obtain the calibration matrix by multivariate calibration, different parameters were evaluated. The adequate selection of the spectral regions proved to be important on the number of factors. In order to simultaneously quantify both hydrochlorides among excipients, the spectral region between 250 and 290 nm was selected. A recovery for the vasoconstrictor was 98-101%. The developed method was applied to assay of two decongestive pharmaceutical preparations.

Biosensors for Non-Invasive Detection of Celiac Disease Biomarkers in Body Fluids.

PubMed

Pasinszki, Tibor; Krebsz, Melinda

2018-06-16

Celiac disease is a chronic gluten-initiated autoimmune disorder that predominantly damages the mucosa of the small intestine in genetically-susceptible individuals. It affects a large and increasing number of the world’s population. The diagnosis of this disease and monitoring the response of patients to the therapy, which is currently a life-long gluten-free diet, require the application of reliable, rapid, sensitive, selective, simple, and cost-effective analytical tools. Celiac disease biomarker detection in full blood, serum, or plasma offers a non-invasive way to do this and is well-suited to being the first step of diagnosis. Biosensors provide a novel and alternative way to perform conventional techniques in biomarker sensing, in which electrode material and architecture play important roles in achieving sensitive, selective, and stable detection. There are many opportunities to build and modify biosensor platforms using various materials and detection methods, and the aim of the present review is to summarize developments in this field.

One-pot preparation of mRNA/cDNA display by a novel and versatile puromycin-linker DNA.

PubMed

Mochizuki, Yuki; Biyani, Manish; Tsuji-Ueno, Sachika; Suzuki, Miho; Nishigaki, Koichi; Husimi, Yuzuru; Nemoto, Naoto

2011-09-12

A rapid, easy, and robust preparation method for mRNA/cDNA display using a newly designed puromycin-linker DNA is presented. The new linker is structurally simple, easy to synthesize, and cost-effective for use in "in vitro peptide and protein selection". An introduction of RNase T1 nuclease site to the new linker facilitates the easy recovery of mRNA/cDNA displayed protein by an improvement of the efficiency of ligating the linker to mRNAs and efficient release of mRNA/cDNA displayed protein from the solid-phase (magnetic bead). For application demonstration, affinity selections were successfully performed. Furthermore, we introduced a "one-pot" preparation protocol to perform mRNA display easy. Unlike conventional approaches that require tedious and downstream multistep process including purification, this protocol will make the mRNA/cDNA display methods more practical and convenient and also facilitate the development of next-generation, high-throughput mRNA/cDNA display systems amenable to automation.

Direct injection analysis of fatty and resin acids in papermaking process waters by HPLC/MS.

PubMed

Valto, Piia; Knuutinen, Juha; Alén, Raimo

2011-04-01

A novel HPLC-atmospheric pressure chemical ionization/MS (HPLC-APCI/MS) method was developed for the rapid analysis of selected fatty and resin acids typically present in papermaking process waters. A mixture of palmitic, stearic, oleic, linolenic, and dehydroabietic acids was separated by a commercial HPLC column (a modified stationary C(18) phase) using gradient elution with methanol/0.15% formic acid (pH 2.5) as a mobile phase. The internal standard (myristic acid) method was used to calculate the correlation coefficients and in the quantitation of the results. In the thorough quality parameters measurement, a mixture of these model acids in aqueous media as well as in six different paper machine process waters was quantitatively determined. The measured quality parameters, such as selectivity, linearity, precision, and accuracy, clearly indicated that, compared with traditional gas chromatographic techniques, the simple method developed provided a faster chromatographic analysis with almost real-time monitoring of these acids. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Genetic code translation displays a linear trade-off between efficiency and accuracy of tRNA selection.

PubMed

Johansson, Magnus; Zhang, Jingji; Ehrenberg, Måns

2012-01-03

Rapid and accurate translation of the genetic code into protein is fundamental to life. Yet due to lack of a suitable assay, little is known about the accuracy-determining parameters and their correlation with translational speed. Here, we develop such an assay, based on Mg(2+) concentration changes, to determine maximal accuracy limits for a complete set of single-mismatch codon-anticodon interactions. We found a simple, linear trade-off between efficiency of cognate codon reading and accuracy of tRNA selection. The maximal accuracy was highest for the second codon position and lowest for the third. The results rationalize the existence of proofreading in code reading and have implications for the understanding of tRNA modifications, as well as of translation error-modulating ribosomal mutations and antibiotics. Finally, the results bridge the gap between in vivo and in vitro translation and allow us to calibrate our test tube conditions to represent the environment inside the living cell.

Detection of enteropathogenic Escherichia coli by microchip capillary electrophoresis.

PubMed

Law, Wai S; Li, Sam F Y; Kricka, Larry J

2009-01-01

There is always a need to detect the presence of microorganisms, either as contaminants in food and pharmaceutical industries or bioindicators for disease diagnosis. Hence, it is important to develop efficient, rapid, and simple methods to detect microorganisms. Traditional culturing method is unsatisfactory due to its long incubation time. Molecular methods, although capable of providing a high degree of specificity, are not always useful in providing quick tests of presence or absence of microorganisms. Microchip elec-trophoresis has been recently employed to address problems associated with the detection of microorganisms due to its high versatility, selectivity, sensitivity, and short analysis times. In this work, the potential of PDMS-based microchip electrophoresis in the identification and characterization of microorganism was evaluated. Enteropathogenic E. coli (EPEC) was selected as the model microorganism. To obtain repeat-able separations, sample pretreatment was found to be essential. Microchip electrophoresis with laser-induced fluorescence detection could potentially revolutionize certain aspects of microbiology involving diagnosis, profiling of pathogens, environmental analysis, and many others areas of study.

Highly sensitive and selective determination of Hg(II) based on microfluidic chip with on-line fluorescent derivatization.

PubMed

Peng, Guilong; Chen, Yi; Deng, Ruoyu; He, Qiang; Liu, Dun; Lu, Ying; Lin, Jin-Ming

2018-06-07

In this study, a convenient, sensitive, rapid and simple method was developed on microfluidic chip which was integrated with on-line complexing and laser-induced fluorescence detection. A rhodamine derivative (RD) was developed as a fluorescent chemosensor for Hg(II). It exhibited high selective recognition toward Hg(II) over other examined metal ions in water samples. Under the optimized conditions, the response was linearly proportional to the concentration of Hg(II) in the range of 0-70 μM with a detection limit of 0.031 μM. Satisfactory repeatability and reproducibility were achieved, with a relative standard deviation (RSD) of 6.62%. The established method was successfully applied for the determination of Hg(II) in environmental water samples (surface water, tap water, and waste water). Recoveries obtained for the determination of Hg(II) in spiking samples ranged from 85% to 103%. Copyright © 2018. Published by Elsevier B.V.

Reciprocal inhibition of inhibition: A circuit motif for flexible categorization in stimulus selection

PubMed Central

Knudsen, Eric I.

2011-01-01

As a precursor to the selection of a stimulus for gaze and attention, a midbrain network categorizes stimuli into “strongest” and “others.” The categorization tracks flexibly, in real-time, the absolute strength of the strongest stimulus. In this study, we take a first principles approach to computations that are essential for such categorization. We demonstrate that classical feedforward lateral inhibition cannot produce flexible categorization. However, circuits in which the strength of lateral inhibition varies with the relative strength of competing stimuli categorize successfully. One particular implementation - reciprocal inhibition of feedforward lateral inhibition – is structurally the simplest, and it outperforms others in flexibly categorizing rapidly and reliably. Strong predictions of this anatomically supported circuit model are validated by neural responses measured in the owl midbrain. The results demonstrate the extraordinary power of a remarkably simple, neurally grounded circuit motif in producing flexible categorization, a computation fundamental to attention, perception, and decision-making. PMID:22243757

A fluorescent aptasensor for sensitive analysis oxytetracycline based on silver nanoclusters.

PubMed

Hosseini, Morteza; Mehrabi, Fatemeh; Ganjali, Mohammad Reza; Norouzi, Parviz

2016-11-01

A fluorescent aptasensor for detection of oxytetracycline (OTC) was presented based on fluorescence quenching of DNA aptamer-templated silver nanoclusters (AgNCs). The specific DNA scaffolds with two different nucleotides fragments were used: one was enriched with a cytosine sequence fragment (C12) that could produce DNA-AgNCs via a chemical reduction method, and another was the OTC aptamer fragment that could selectively bind to the OTC antibiotic. Thus, the as-prepared AgNCs could exhibit quenched fluorescence after binding to the target OTC. The fluorescence ratio of the DNA-AgNCs was quenched in a linearly proportional manner to the concentration of the target in the range of 0.5 nM to 100 nM with a detection limit of 0.1 nM. This proposed nanobiosensor was demonstrated to be sensitive, selective, and simple, introducing a viable alternative for rapid determination of toxin OTC in honey and water samples. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

A simple animal support for convenient weighing

USGS Publications Warehouse

Pan, H.P.; Caslick, J.W.; Harke, D.T.; Decker, D.G.

1965-01-01

A simple animal support constructed of web belts to hold skittish pigs for weighing was developed. The support is easily made, noninjurious to the pigs, and compact, facilitating rapid, accurate weighing. With minor modifications, the support can probably be used in weighing other animals.

[Analysis on the accuracy of simple selection method of Fengshi (GB 31)].

PubMed

Li, Zhixing; Zhang, Haihua; Li, Suhe

2015-12-01

To explore the accuracy of simple selection method of Fengshi (GB 31). Through the study of the ancient and modern data,the analysis and integration of the acupuncture books,the comparison of the locations of Fengshi (GB 31) by doctors from all dynasties and the integration of modern anatomia, the modern simple selection method of Fengshi (GB 31) is definite, which is the same as the traditional way. It is believed that the simple selec tion method is in accord with the human-oriented thought of TCM. Treatment by acupoints should be based on the emerging nature and the individual difference of patients. Also, it is proposed that Fengshi (GB 31) should be located through the integration between the simple method and body surface anatomical mark.

Preparation, structural characterization, and catalytic performance of Pd(II) and Pt(II) complexes derived from cellulose Schiff base

NASA Astrophysics Data System (ADS)

Baran, Talat; Yılmaz Baran, Nuray; Menteş, Ayfer

2018-05-01

In this study, we reported production, characterization, and catalytic behavior of two novel heterogeneous palladium(II) and platinum(II) catalysts derived from cellulose biopolymer. In order to eliminate the use of toxic organic or inorganic solvents and to reduce the use of excess energy in the coupling reactions, we have developed a very simple, rapid, and eco-friendly microwave irradiation protocol. The developed microwave-assisted method of Suzuki cross coupling reactions produced excellent reaction yields in the presence of cellulose supported palladium and platinum (II) catalysts. Moreover, the catalysts easily regenerated after simple filtration, and they gave good reusability. This study revealed that the designed catalysts and method provide clean, simple, rapid, and impressive catalytic performance for Suzuki coupling reactions.

Near instrument-free, simple molecular device for rapid detection of herpes simplex viruses.

PubMed

Lemieux, Bertrand; Li, Ying; Kong, Huimin; Tang, Yi-Wei

2012-06-01

The first near instrument-free, inexpensive and simple molecular diagnostic device (IsoAmp HSV, BioHelix Corp., MA, USA) recently received US FDA clearance for use in the detection of herpes simplex viruses (HSV) in genital and oral lesion specimens. The IsoAmp HSV assay uses isothermal helicase-dependent amplification in combination with a disposable, hermetically-sealed, vertical-flow strip identification. The IsoAmp HSV assay has a total test-to-result time of less than 1.5 h by omitting the time-consuming nucleic acid extraction. The diagnostic sensitivity and specificity are comparable to PCR and are superior to culture-based methods. The near instrument-free, rapid and simple characteristics of the IsoAmp HSV assay make it potentially suitable for point-of-care testing.

A rapid mechanism to remobilize and homogenize highly crystalline magma bodies.

PubMed

Burgisser, Alain; Bergantz, George W

2011-03-10

The largest products of magmatic activity on Earth, the great bodies of granite and their corresponding large eruptions, have a dual nature: homogeneity at the large scale and spatial and temporal heterogeneity at the small scale. This duality calls for a mechanism that selectively removes the large-scale heterogeneities associated with the incremental assembly of these magmatic systems and yet occurs rapidly despite crystal-rich, viscous conditions seemingly resistant to mixing. Here we show that a simple dynamic template can unify a wide range of apparently contradictory observations from both large plutonic bodies and volcanic systems by a mechanism of rapid remobilization (unzipping) of highly viscous crystal-rich mushes. We demonstrate that this remobilization can lead to rapid overturn and produce the observed juxtaposition of magmatic materials with very disparate ages and complex chemical zoning. What distinguishes our model is the recognition that the process has two stages. Initially, a stiff mushy magma is reheated from below, producing a reduction in crystallinity that leads to the growth of a subjacent buoyant mobile layer. When the thickening mobile layer becomes sufficiently buoyant, it penetrates the overlying viscous mushy magma. This second stage rapidly exports homogenized material from the lower mobile layer to the top of the system, and leads to partial overturn within the viscous mush itself as an additional mechanism of mixing. Model outputs illustrate that unzipping can rapidly produce large amounts of mobile magma available for eruption. The agreement between calculated and observed unzipping rates for historical eruptions at Pinatubo and at Montserrat demonstrates the general applicability of the model. This mechanism furthers our understanding of both the formation of periodically homogenized plutons (crust building) and of ignimbrites by large eruptions.

Development of a rapid SNP-typing assay to differentiate Bifidobacterium animalis ssp. lactis strains used in probiotic-supplemented dairy products.

PubMed

Lomonaco, Sara; Furumoto, Emily J; Loquasto, Joseph R; Morra, Patrizia; Grassi, Ausilia; Roberts, Robert F

2015-02-01

Identification at the genus, species, and strain levels is desirable when a probiotic microorganism is added to foods. Strains of Bifidobacterium animalis ssp. lactis (BAL) are commonly used worldwide in dairy products supplemented with probiotic strains. However, strain discrimination is difficult because of the high degree of genome identity (99.975%) between different genomes of this subspecies. Typing of monomorphic species can be carried out efficiently by targeting informative single nucleotide polymorphisms (SNP). Findings from a previous study analyzing both reference and commercial strains of BAL identified SNP that could be used to discriminate common strains into 8 groups. This paper describes development of a minisequencing assay based on the primer extension reaction (PER) targeting multiple SNP that can allow strain differentiation of BAL. Based on previous data, 6 informative SNP were selected for further testing, and a multiplex preliminary PCR was optimized to amplify the DNA regions containing the selected SNP. Extension primers (EP) annealing immediately adjacent to the selected SNP were developed and tested in simplex and multiplex PER to evaluate their performance. Twenty-five strains belonging to 9 distinct genomic clusters of B. animalis ssp. lactis were selected and analyzed using the developed minisequencing assay, simultaneously targeting the 6 selected SNP. Fragment analysis was subsequently carried out in duplicate and demonstrated that the assay yielded 8 specific profiles separating the most commonly used commercial strains. This novel multiplex PER approach provides a simple, rapid, flexible SNP-based subtyping method for proper characterization and identification of commercial probiotic strains of BAL from fermented dairy products. To assess the usefulness of this method, DNA was extracted from yogurt manufactured with and without the addition of B. animalis ssp. lactis BB-12. Extracted DNA was then subjected to the minisequencing protocol, resulting in a SNP profile matching the profile for the strain BB-12. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Using lot quality-assurance sampling and area sampling to identify priority areas for trachoma control: Viet Nam.

PubMed

Myatt, Mark; Mai, Nguyen Phuong; Quynh, Nguyen Quang; Nga, Nguyen Huy; Tai, Ha Huy; Long, Nguyen Hung; Minh, Tran Hung; Limburg, Hans

2005-10-01

To report on the use of lot quality-assurance sampling (LQAS) surveys undertaken within an area-sampling framework to identify priority areas for intervention with trachoma control activities in Viet Nam. The LQAS survey method for the rapid assessment of the prevalence of active trachoma was adapted for use in Viet Nam with the aim of classifying individual communes by the prevalence of active trachoma among children in primary school. School-based sampling was used; school sites to be sampled were selected using an area-sampling approach. A total of 719 communes in 41 districts in 18 provinces were surveyed. Survey staff found the LQAS survey method both simple and rapid to use after initial problems with area-sampling methods were identified and remedied. The method yielded a finer spatial resolution of prevalence than had been previously achieved in Viet Nam using semiquantitative rapid assessment surveys and multistage cluster-sampled surveys. When used with area-sampling techniques, the LQAS survey method has the potential to form the basis of survey instruments that can be used to efficiently target resources for interventions against active trachoma. With additional work, such methods could provide a generally applicable tool for effective programme planning and for the certification of the elimination of trachoma as a blinding disease.

Endpoint visual detection of three genetically modified rice events by loop-mediated isothermal amplification.

PubMed

Chen, Xiaoyun; Wang, Xiaofu; Jin, Nuo; Zhou, Yu; Huang, Sainan; Miao, Qingmei; Zhu, Qing; Xu, Junfeng

2012-11-07

Genetically modified (GM) rice KMD1, TT51-1, and KF6 are three of the most well known transgenic Bt rice lines in China. A rapid and sensitive molecular assay for risk assessment of GM rice is needed. Polymerase chain reaction (PCR), currently the most common method for detecting genetically modified organisms, requires temperature cycling and relatively complex procedures. Here we developed a visual and rapid loop-mediated isothermal amplification (LAMP) method to amplify three GM rice event-specific junction sequences. Target DNA was amplified and visualized by two indicators (SYBR green or hydroxy naphthol blue [HNB]) within 60 min at an isothermal temperature of 63 °C. Different kinds of plants were selected to ensure the specificity of detection and the results of the non-target samples were negative, indicating that the primer sets for the three GM rice varieties had good levels of specificity. The sensitivity of LAMP, with detection limits at low concentration levels (0.01%−0.005% GM), was 10- to 100-fold greater than that of conventional PCR. Additionally, the LAMP assay coupled with an indicator (SYBR green or HNB) facilitated analysis. These findings revealed that the rapid detection method was suitable as a simple field-based test to determine the status of GM crops.

Poisoning by Herbs and Plants: Rapid Toxidromic Classification and Diagnosis.

PubMed

Diaz, James H

2016-03-01

The American Association of Poison Control Centers has continued to report approximately 50,000 telephone calls or 8% of incoming calls annually related to plant exposures, mostly in children. Although the frequency of plant ingestions in children is related to the presence of popular species in households, adolescents may experiment with hallucinogenic plants; and trekkers and foragers may misidentify poisonous plants as edible. Since plant exposures have continued at a constant rate, the objectives of this review were (1) to review the epidemiology of plant poisonings; and (2) to propose a rapid toxidromic classification system for highly toxic plant ingestions for field use by first responders in comparison to current classification systems. Internet search engines were queried to identify and select peer-reviewed articles on plant poisonings using the key words in order to classify plant poisonings into four specific toxidromes: cardiotoxic, neurotoxic, cytotoxic, and gastrointestinal-hepatotoxic. A simple toxidromic classification system of plant poisonings may permit rapid diagnoses of highly toxic versus less toxic and nontoxic plant ingestions both in households and outdoors; direct earlier management of potentially serious poisonings; and reduce costly inpatient evaluations for inconsequential plant ingestions. The current textbook classification schemes for plant poisonings were complex in comparison to the rapid classification system; and were based on chemical nomenclatures and pharmacological effects, and not on clearly presenting toxidromes. Validation of the rapid toxidromic classification system as compared to existing chemical classification systems for plant poisonings will require future adoption and implementation of the toxidromic system by its intended users. Copyright © 2016 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.

Use of refractometry and colorimetry as field methods to rapidly assess antimalarial drug quality.

PubMed

Green, Michael D; Nettey, Henry; Villalva Rojas, Ofelia; Pamanivong, Chansapha; Khounsaknalath, Lamphet; Grande Ortiz, Miguel; Newton, Paul N; Fernández, Facundo M; Vongsack, Latsamy; Manolin, Ot

2007-01-04

The proliferation of counterfeit and poor-quality drugs is a major public health problem; especially in developing countries lacking adequate resources to effectively monitor their prevalence. Simple and affordable field methods provide a practical means of rapidly monitoring drug quality in circumstances where more advanced techniques are not available. Therefore, we have evaluated refractometry, colorimetry and a technique combining both processes as simple and accurate field assays to rapidly test the quality of the commonly available antimalarial drugs; artesunate, chloroquine, quinine, and sulfadoxine. Method bias, sensitivity, specificity and accuracy relative to high-performance liquid chromatographic (HPLC) analysis of drugs collected in the Lao PDR were assessed for each technique. The HPLC method for each drug was evaluated in terms of assay variability and accuracy. The accuracy of the combined method ranged from 0.96 to 1.00 for artesunate tablets, chloroquine injectables, quinine capsules, and sulfadoxine tablets while the accuracy was 0.78 for enterically coated chloroquine tablets. These techniques provide a generally accurate, yet simple and affordable means to assess drug quality in resource-poor settings.

Rapid quantification of free cholesterol in tears using direct insertion/electron ionization-mass spectrometry.

PubMed

Wei, Xiaojia Eric; Korth, John; Brown, Simon H J; Mitchell, Todd W; Truscott, Roger J W; Blanksby, Stephen J; Willcox, Mark D P; Zhao, Zhenjun

2013-12-09

To establish a simple and rapid analytical method, based on direct insertion/electron ionization-mass spectrometry (DI/EI-MS), for measuring free cholesterol in tears from humans and rabbits. A stable-isotope dilution protocol employing DI/EI-MS in selected ion monitoring mode was developed and validated. It was used to quantify the free cholesterol content in human and rabbit tear extracts. Tears were collected from adult humans (n = 15) and rabbits (n = 10) and lipids extracted. Screening, full-scan (m/z 40-600) DI/EI-MS analysis of crude tear extracts showed that diagnostic ions located in the mass range m/z 350 to 400 were those derived from free cholesterol, with no contribution from cholesterol esters. DI/EI-MS data acquired using selected ion monitoring (SIM) were analyzed for the abundance ratios of diagnostic ions with their stable isotope-labeled analogues arising from the D6-cholesterol internal standard. Standard curves of good linearity were produced and an on-probe limit of detection of 3 ng (at 3:1 signal to noise) and limit of quantification of 8 ng (at 10:1 signal to noise). The concentration of free cholesterol in human tears was 15 ± 6 μg/g, which was higher than in rabbit tears (10 ± 5 μg/g). A stable-isotope dilution DI/EI-SIM method for free cholesterol quantification without prior chromatographic separation was established. Using this method demonstrated that humans have higher free cholesterol levels in their tears than rabbits. This is in agreement with previous reports. This paper provides a rapid and reliable method to measure free cholesterol in small-volume clinical samples.

A rapid and simple method of detection of Blepharisma japonicum using PCR and immobilisation on FTA paper

PubMed Central

Hide, Geoff; Hughes, Jacqueline M; McNuff, Robert

2003-01-01

Background The rapid expansion in the availability of genome and DNA sequence information has opened up new possibilities for the development of methods for detecting free-living protozoa in environmental samples. The protozoan Blepharisma japonicum was used to investigate a rapid and simple detection system based on polymerase chain reaction amplification (PCR) from organisms immobilised on FTA paper. Results Using primers designed from the α-tubulin genes of Blepharisma, specific and sensitive detection to the equivalent of a single Blepharisma cell could be achieved. Similar detection levels were found using water samples, containing Blepharisma, which were dried onto Whatman FTA paper. Conclusion This system has potential as a sensitive convenient detection system for Blepharisma and could be applied to other protozoan organisms. PMID:14516472

Rapid and Programmable Protein Mutagenesis Using Plasmid Recombineering.

PubMed

Higgins, Sean A; Ouonkap, Sorel V Y; Savage, David F

2017-10-20

Comprehensive and programmable protein mutagenesis is critical for understanding structure-function relationships and improving protein function. There is thus a need for robust and unbiased molecular biological approaches for the construction of the requisite comprehensive protein libraries. Here we demonstrate that plasmid recombineering is a simple and robust in vivo method for the generation of protein mutants for both comprehensive library generation as well as programmable targeting of sequence space. Using the fluorescent protein iLOV as a model target, we build a complete mutagenesis library and find it to be specific and comprehensive, detecting 99.8% of our intended mutations. We then develop a thermostability screen and utilize our comprehensive mutation data to rapidly construct a targeted and multiplexed library that identifies significantly improved variants, thus demonstrating rapid protein engineering in a simple protocol.

Simultaneous determination of 13 carotenoids by a simple C18 column-based ultra-high-pressure liquid chromatography method for carotenoid profiling in the astaxanthin-accumulating Haematococcus pluvialis.

PubMed

Jin, Hui; Lao, Yong Min; Zhou, Jin; Zhang, Huai Jin; Cai, Zhong Hua

2017-03-10

A simple ultra-high-pressure liquid chromatography (UHPLC) method for rapidly and simultaneously identifying thirteen carotenoids in Haematococcus pluvialis was developed in this study. The method is capable of effectively separating two astaxanthin isomers, two ζ-carotene isomers, and three phytoene isomers on two simple C18 columns within 9 and 12min only by using methanol and acetonitrile, respectively. To our best knowledge, this is the rapidest method for these carotenoid isomers, currently. Using this method, carotenoid profiling in the astaxanthin-accumulating H. pluvialis under environmental stresses was successfully carried out. Results indicated that carotenoid biosynthesis was differentially perturbed by environmental stresses, indicating that this simple and rapid method is suitable to not only bacterial but also algal samples, with potential applications for a wide range of samples from plant to animal. Finally, possible reasons for the elution order of carotenoids were studied. Copyright © 2017 Elsevier B.V. All rights reserved.

Validation of a Rapid Bacteria Endospore Enumeration System for Planetary Protection Application

NASA Astrophysics Data System (ADS)

Chen, Fei; Kern, Roger; Kazarians, Gayane; Venkateswaran, Kasthuri

NASA monitors spacecraft surfaces to assure that the presence of bacterial endospores meets strict criteria at launch, to minimize the risk of inadvertent contamination of the surface of Mars. Currently, the only approved method for enumerating the spores is a culture based assay that requires three days to produce results. In order to meet the demanding schedules of spacecraft assembly, a more rapid spore detection assay is being considered as an alternate method to the NASA standard culture-based assay. The Millipore Rapid Microbiology Detection System (RMDS) has been used successfully for rapid bioburden enumeration in the pharmaceutical and food industries. The RMDS is rapid and simple, shows high sensitivity (to 1 colony forming unit [CFU]/sample), and correlates well with traditional culture-based methods. It combines membrane filtration, adenosine triphosphate (ATP) bioluminescence chemistry, and image analysis based on photon detection with a Charge Coupled Device (CCD) camera. In this study, we have optimized the assay conditions and evaluated the use of the RMDS as a rapid spore detection tool for NASA applications. In order to select for spores, the samples were subjected to a heat shock step before proceeding with the RMDS incubation protocol. Seven species of Bacillus (nine strains) that have been repeatedly isolated from clean room environments were assayed. All strains were detected by the RMDS in 5 hours and these assay times were repeatedly demonstrated along with low image background noise. Validation experiments to compare the Rapid Sore Assay (RSA) and NASA standard assay (NSA) were also performed. The evaluation criteria were modeled after the FDA Guideline of Process Validation, and Analytical Test Methods. This body of research demonstrates that the Rapid Spore Assay (RSA) is quick, and of equivalent sensitivity to the NASA standard assay, potentially reducing the assay time for bacterial endospores from over 72 hours to less than 8 hours. Accordingly, JPL has produced a report recommending that NASA adopt the RSA method as a suitable alternative to the NASA standard assay.

Graphene nano-ink biosensor arrays on a microfluidic paper for multiplexed detection of metabolites.

PubMed

Labroo, Pratima; Cui, Yue

2014-02-27

The development of a miniaturized and low-cost platform for the highly sensitive, selective and rapid detection of multiplexed metabolites is of great interest for healthcare, pharmaceuticals, food science, and environmental monitoring. Graphene is a delicate single-layer, two-dimensional network of carbon atoms with extraordinary electrical sensing capability. Microfluidic paper with printing technique is a low cost matrix. Here, we demonstrated the development of graphene-ink based biosensor arrays on a microfluidic paper for the multiplexed detection of different metabolites, such as glucose, lactate, xanthine and cholesterol. Our results show that the graphene biosensor arrays can detect multiple metabolites on a microfluidic paper sensitively, rapidly and simultaneously. The device exhibits a fast measuring time of less than 2 min, a low detection limit of 0.3 μM, and a dynamic detection range of 0.3-15 μM. The process is simple and inexpensive to operate and requires a low consumption of sample volume. We anticipate that these results could open exciting opportunities for a variety of applications. Copyright © 2014 Elsevier B.V. All rights reserved.

TREE2FASTA: a flexible Perl script for batch extraction of FASTA sequences from exploratory phylogenetic trees.

PubMed

Sauvage, Thomas; Plouviez, Sophie; Schmidt, William E; Fredericq, Suzanne

2018-03-05

The body of DNA sequence data lacking taxonomically informative sequence headers is rapidly growing in user and public databases (e.g. sequences lacking identification and contaminants). In the context of systematics studies, sorting such sequence data for taxonomic curation and/or molecular diversity characterization (e.g. crypticism) often requires the building of exploratory phylogenetic trees with reference taxa. The subsequent step of segregating DNA sequences of interest based on observed topological relationships can represent a challenging task, especially for large datasets. We have written TREE2FASTA, a Perl script that enables and expedites the sorting of FASTA-formatted sequence data from exploratory phylogenetic trees. TREE2FASTA takes advantage of the interactive, rapid point-and-click color selection and/or annotations of tree leaves in the popular Java tree-viewer FigTree to segregate groups of FASTA sequences of interest to separate files. TREE2FASTA allows for both simple and nested segregation designs to facilitate the simultaneous preparation of multiple data sets that may overlap in sequence content.

Fatty acid transfer between multilamellar liposomes and fatty acid-binding proteins.

PubMed

Brecher, P; Saouaf, R; Sugarman, J M; Eisenberg, D; LaRosa, K

1984-11-10

A simple experimental system was developed for studying the movement of long-chain fatty acids between multilamellar liposomes and soluble proteins capable of binding fatty acids. Oleic acid was incorporated into multilamellar liposomes containing cholesterol and egg yolk lecithin and incubated with albumin or hepatic fatty acid-binding protein. It was found that the fatty acid transferred from the liposomes to either protein rapidly and selectively under conditions where phospholipid and cholesterol transfer did not occur. More than 50% of the fatty acid contained within liposomes could become protein bound, suggesting that the fatty acid moved readily between and across phospholipid bilayers. Transfer was reduced at low pH, and this reduction appeared to result from decreased dissociation of the protonated fatty acid from the bilayer. Liposomes made with dimyristoyl or dipalmitoyl lecithin and containing 1 mol per cent palmitic acid were used to show the effect of temperature on fatty acid transfer. Transfer to either protein did not occur at temperatures where the liposomes were in a gel state but occurred rapidly at temperatures at or above the transition temperatures of the phospholipid used.

Global ensemble texture representations are critical to rapid scene perception.

PubMed

Brady, Timothy F; Shafer-Skelton, Anna; Alvarez, George A

2017-06-01

Traditionally, recognizing the objects within a scene has been treated as a prerequisite to recognizing the scene itself. However, research now suggests that the ability to rapidly recognize visual scenes could be supported by global properties of the scene itself rather than the objects within the scene. Here, we argue for a particular instantiation of this view: That scenes are recognized by treating them as a global texture and processing the pattern of orientations and spatial frequencies across different areas of the scene without recognizing any objects. To test this model, we asked whether there is a link between how proficient individuals are at rapid scene perception and how proficiently they represent simple spatial patterns of orientation information (global ensemble texture). We find a significant and selective correlation between these tasks, suggesting a link between scene perception and spatial ensemble tasks but not nonspatial summary statistics In a second and third experiment, we additionally show that global ensemble texture information is not only associated with scene recognition, but that preserving only global ensemble texture information from scenes is sufficient to support rapid scene perception; however, preserving the same information is not sufficient for object recognition. Thus, global ensemble texture alone is sufficient to allow activation of scene representations but not object representations. Together, these results provide evidence for a view of scene recognition based on global ensemble texture rather than a view based purely on objects or on nonspatially localized global properties. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Development of Rapid Diagnostic Kit for Identification of Hanwoo (Korean Native Cattle) Brand Meat by Detecting BIO-TAG

PubMed Central

Park, Sung Kwon; Lee, Myung Hoon; Cho, Soo Hyun

2014-01-01

This study was performed to develop a rapid immuno-assay kit, by using a specific antigen to detect Hanwoo brand meat. We selected a synthetic antigen specific to our target antibody, named BIO-TAG (Tyr-D-Ala-Phe), by utilizing a computer-based analysis and literature review. BIO-TAG tagged with adjuvant was subcutaneously injected in sheep and Hanwoo. The serum and meat juice of the immunized or non-immunized animal were then analyzed, to measure the titer of antibody by ELISA and Western blot. The amount of antibodies against the BIO-TAG increased (p<0.05) in serum by vaccination. Furthermore, meat juice from the immunized Hanwoo showed greater (p<0.05) antibody titer, compared with those from non-immunized groups. To optimze the dilution factor, we performed dot-ELISA, with various combination levels of BIO-TAG. Results from dot-ELISA showed that 2 mg/mL BIO-TAG was sufficient to distinguish the immunized meat from non-immunized groups. These results support our hypothesis that simple immunization of Hanwoo generates a sufficient amount of antibodies to be detectable in the meat juice by means of the immune-assay. Therefore, specific Hanwoo brand meat can be more precisely identified by our rapid diagnostic kit. This technology can deter possible fraud of counterfeit meat brands in the Korean domestic market with ease and rapidity; and offers a new tool that guarantees consumers high quality Hanwoo brand beef. PMID:26761175

Rapid determination of 1-deoxynojirimycin in Morus alba L. leaves by direct analysis in real time (DART) mass spectrometry.

PubMed

Xu, Bin; Zhang, Dong-Yang; Liu, Ze-Yu; Zhang, Ying; Liu, Li; Li, Long; Liu, Charles C; Wu, Guo-Hua

2015-10-10

A new method based on a Direct Analysis in Real Time (DART) ionization source coupled with triple quadrupole tandem mass spectrometry has been developed for rapid qualitative and quantitative analyses of 1-deoxynojirimycin (DNJ) in mulberry leaves. Two ions produced from DNJ, [M+H](+) (m/z 164) and [M-2H+H](+) (m/z 162), are observed using DART-MS in the positive ion mode. The peak areas of the two selected ions monitoring (SIM) signals of ([M+H](+) (m/z 164) and [M-2H+H](+) (m/z 162)) are integrated to determine the peak area for quantitative analyses. A reasonable linear regression equation is obtained in the range of 1.01 to 40.50 μg/mL, with a linear coefficient (R(2)) of 0.996. The limits of detection (LOD) and quantification (LOQ) of the method are 0.25 and 0.80 μg/mL, respectively. The range of recovery is shown to be 87.73-95.61%. The results derived from the developed DART-MS method are in good agreement with those from the conventional HPLC-FLD method. By contrast, DART-MS in SIM mode is a simple, rapid and high-throughput approach for the determination of the DNJ content in mulberry leaves. The present method is advantageous for the rapid screening of mulberry leaves containing high DNJ contents. Copyright © 2015 Elsevier B.V. All rights reserved.

Highly selective electrode for potentiometric analysis of methadone in biological fluids and pharmaceutical formulations.

PubMed

Ardeshiri, Moslem; Jalali, Fahimeh

2016-06-01

In order to develop a fast and simple procedure for methadone analysis in biological fluids, a graphite paste electrode (GPE) was modified with the ion-pair of methadone-phosphotungstic acid, and multiwalled carbon nanotubes (MWCNTs). Optimized composition of the electrode with respect to graphite powder:paraffin oil:MWCNTs:ion pair, was 58:30:8:4 (w/w%). The electrode showed a near-Nernstian slope of 58.9 ± 0.3 mV/decade for methadone in a wide linear range of 1.0 × 10(-8)-4.6 × 10(-3)M, with a detection limit of 1.0 × 10(-8)M. The electrode response was independent of pH in the range of 5-11, with a fast response time (~4s) at 25 °C. The sensor showed high selectivity and was successfully applied to the determination of sub-micromolar concentrations of methadone in human blood serum and urine samples, with recoveries in the range of 95-99.8%. The average recovery of methadone from tablets (5 mg/tablet) by using the proposed method was 98%. The life time of the modified electrode was more than 5 months, due to the characteristic of GPE which can be cut off and fresh electrode surface be available. A titration procedure was performed for methadone analysis by using phosphotungstic acid, as titrating agent, which showed an accurate end point and 1:1 stoichiometry for the ion-pair formed (methadone:phosphotungstic acid). The simple and rapid procedure as well as excellent detection limit and selectivity are some of the advantages of the proposed sensor for methadone. Copyright © 2016 Elsevier B.V. All rights reserved.

A simple turn on fluorescent sensor for the selective detection of thiamine using coconut water derived luminescent carbon dots.

PubMed

Purbia, Rahul; Paria, Santanu

2016-05-15

In this study microwave-assisted hydrothermal method was used to prepare highly luminescent carbon dots (1-6 nm size) within a minute from tender coconut (Cocos nucifera) water. The synthesized carbon dots (C-dots) exhibit emission of blue and green lights while excited at 390 and 450 nm wavelengths, respectively. As an application, these C-dots were tested for a simple "turn on" fluorescent sensor for rapid detection of thiamine (vitamin B1). The detection of thiamine in human body is very important to prevent various diseases such as beriberi, neurological disorders, optic neuropathy, etc. The fluorescence emission intensity of C-dots quenches after addition of Cu(2+) ion and then again increases selectively (turn on) after the addition of thiamine. The fluorescence emission intensity enhancement of Cu(2+) ion modified C-dots in the presence of thiamine exhibits a linear relationship within the thiamine concentration range of 10-50 μM. The limit of detection was found to be 280 nM from this study. The selectivity of the detection was also tested in the presence of different organic molecules and inorganic ions (Ca(2+), Mg(2+), Na(+), K(+), Cl(-), SO4(2-), and NO3(-)) which are present in blood serum and urine and found to be almost no interference in the detection. Finally, to see the applicability in real samples a commercial vitamin capsule was tested and found less than 3% error in the detected concentration. The C-dots were also used for bioimaging of fungus and the results show they are also suitable for this application too. Copyright © 2015 Elsevier B.V. All rights reserved.

Highly Selective and Rapid Breath Isoprene Sensing Enabled by Activated Alumina Filter.

PubMed

van den Broek, Jan; Güntner, Andreas T; Pratsinis, Sotiris E

2018-03-23

Isoprene is a versatile breath marker for noninvasive monitoring of high blood cholesterol levels as well as for influenza, end-stage renal disease, muscle activity, lung cancer, and liver disease with advanced fibrosis. Its selective detection in complex human breath by portable devices (e.g., metal-oxide gas sensors), however, is still challenging. Here, we present a new filter concept based on activated alumina powder enabling fast and highly selective detection of isoprene at the ppb level and high humidity. The filter contains high surface area adsorbents that retain hydrophilic compounds (e.g., ketones, alcohols, ammonia) representing major interferants in breath while hydrophobic isoprene is not affected. As a proof-of-concept, filters of commercial activated alumina powder are combined with highly sensitive but rather nonspecific, nanostructured Pt-doped SnO 2 sensors. This results in fast (10 s) measurement of isoprene down to 5 ppb at 90% relative humidity with outstanding selectivity (>100) to breath-relevant acetone, ammonia, ethanol, and methanol, superior to state-of-the-art isoprene sensors. Most importantly, when exposed continuously to simulated breath mixtures (four analytes) for 8 days, this filter-sensor system showed stable performance. It can be incorporated readily into a portable breath isoprene analyzer promising for simple-in-use monitoring of blood cholesterol or other patho/physiological conditions.

Support Vector Feature Selection for Early Detection of Anastomosis Leakage From Bag-of-Words in Electronic Health Records.

PubMed

Soguero-Ruiz, Cristina; Hindberg, Kristian; Rojo-Alvarez, Jose Luis; Skrovseth, Stein Olav; Godtliebsen, Fred; Mortensen, Kim; Revhaug, Arthur; Lindsetmo, Rolv-Ole; Augestad, Knut Magne; Jenssen, Robert

2016-09-01

The free text in electronic health records (EHRs) conveys a huge amount of clinical information about health state and patient history. Despite a rapidly growing literature on the use of machine learning techniques for extracting this information, little effort has been invested toward feature selection and the features' corresponding medical interpretation. In this study, we focus on the task of early detection of anastomosis leakage (AL), a severe complication after elective surgery for colorectal cancer (CRC) surgery, using free text extracted from EHRs. We use a bag-of-words model to investigate the potential for feature selection strategies. The purpose is earlier detection of AL and prediction of AL with data generated in the EHR before the actual complication occur. Due to the high dimensionality of the data, we derive feature selection strategies using the robust support vector machine linear maximum margin classifier, by investigating: 1) a simple statistical criterion (leave-one-out-based test); 2) an intensive-computation statistical criterion (Bootstrap resampling); and 3) an advanced statistical criterion (kernel entropy). Results reveal a discriminatory power for early detection of complications after CRC (sensitivity 100%; specificity 72%). These results can be used to develop prediction models, based on EHR data, that can support surgeons and patients in the preoperative decision making phase.

Inherited selective intestinal cobalamin malabsorption and cobalamin deficiency in dogs.

PubMed

Fyfe, J C; Giger, U; Hall, C A; Jezyk, P F; Klumpp, S A; Levine, J S; Patterson, D F

1991-01-01

Inherited selective intestinal malabsorption of cobalamin (Cbl) was observed in a family of giant schnauzer dogs. Family studies and breeding experiments demonstrated simple autosomal recessive inheritance of this disease. Affected puppies exhibited chronic inappetence and failure to thrive beginning between 6 and 12 wk of age. Neutropenia with hypersegmentation, anemia with anisocytosis and poikilocytosis, and megaloblastic changes of the bone marrow were present. Serum Cbl concentrations were low, and methylmalonic aciduria and homocysteinemia were present. Parenteral, but not oral, cyanocobalamin administration rapidly eliminated all signs of Cbl deficiency except for low serum Cbl concentrations. Cbl malabsorption in affected dogs was documented by oral administration of [57Co]cyanocobalamin with or without simultaneous oral administration of intrinsic factor or normal dog gastric juice. Quantitation and function studies of intrinsic factor and transcobalamin-II from affected dogs revealed no abnormality. Other gastrointestinal functions and ileal morphology were normal, indicating a selective defect of Cbl absorption at the level of the ileal enterocyte. Immunoelectron microscopy of ileal biopsies showed that the receptor for intrinsic factor-Cbl complex was absent from the apical brush border microvillus pits of affected dogs. This canine disorder resembles inherited selective intestinal Cbl malabsorption (Imerslund-Gräsbeck syndrome) in humans, and is a spontaneously occurring animal model of early onset Cbl deficiency.

Selection of DNA aptamers against Human Cardiac Troponin I for colorimetric sensor based dot blot application.

PubMed

Dorraj, Ghamar Soltan; Rassaee, Mohammad Javad; Latifi, Ali Mohammad; Pishgoo, Bahram; Tavallaei, Mahmood

2015-08-20

Troponin T and I are ideal markers which are highly sensitive and specific for myocardial injury and have shown better efficacy than earlier markers. Since aptamers are ssDNA or RNA that bind to a wide variety of target molecules, the purpose of this research was to select an aptamer from a 79bp single-stranded DNA (ssDNA) random library that was used to bind the Human Cardiac Troponin I from a synthetic nucleic acids library by systematic evolution of ligands exponential enrichment (Selex) based on several selection and amplification steps. Human Cardiac Troponin I protein was coated onto the surface of streptavidin magnetic beads to extract specific aptamer from a large and diverse random ssDNA initial oligonucleotide library. As a result, several aptamers were selected and further examined for binding affinity and specificity. Finally TnIApt 23 showed beast affinity in nanomolar range (2.69nM) toward the target protein. A simple and rapid colorimetric detection assay for Human Cardiac Troponin I using the novel and specific aptamer-AuNPs conjugates based on dot blot assay was developed. The detection limit for this protein using aptamer-AuNPs-based assay was found to be 5ng/ml. Copyright © 2015 Elsevier B.V. All rights reserved.

A simple assay system to monitor the potential for contamination during different stages of cryopreservation.

PubMed

Morris, G J

2009-01-01

A simple assay to monitor the potential for contamination during different steps of cryopreservation is described. The assay is based on the contamination of liquid nitrogen using crystals of sucrose hemi-heptahydrate, these are stable in liquid nitrogen, nitrogen vapour and ambient air and can be monitored by a simple assay which allows contamination risks to be evaluated in a direct, rapid manner.

Fabricating Simple Wax Screen-Printing Paper-Based Analytical Devices to Demonstrate the Concept of Limiting Reagent in Acid- Base Reactions

ERIC Educational Resources Information Center

Namwong, Pithakpong; Jarujamrus, Purim; Amatatongchai, Maliwan; Chairam, Sanoe

2018-01-01

In this article, a low-cost, simple, and rapid fabrication of paper-based analytical devices (PADs) using a wax screen-printing method is reported here. The acid-base reaction is implemented in the simple PADs to demonstrate to students the chemistry concept of a limiting reagent. When a fixed concentration of base reacts with a gradually…

A rapid assessment scorecard to identify informal settlements at higher maternal and child health risk in Mumbai.

PubMed

Osrin, David; Das, Sushmita; Bapat, Ujwala; Alcock, Glyn A; Joshi, Wasundhara; More, Neena Shah

2011-10-01

The communities who live in urban informal settlements are diverse, as are their environmental conditions. Characteristics include inadequate access to safe water and sanitation, poor quality of housing, overcrowding, and insecure residential status. Interventions to improve health should be equity-driven and target those at higher risk, but it is not clear how to prioritise informal settlements for health action. In implementing a maternal and child health programme in Mumbai, India, we had conducted a detailed vulnerability assessment which, though important, was time-consuming and may have included collection of redundant information. Subsequent data collection allowed us to examine three issues: whether community environmental characteristics were associated with maternal and newborn healthcare and outcomes; whether it was possible to develop a triage scorecard to rank the health vulnerability of informal settlements based on a few rapidly observable characteristics; and whether the scorecard might be useful for future prioritisation. The City Initiative for Newborn Health documented births in 48 urban slum areas over 2 years. Information was collected on maternal and newborn care and mortality, and also on household and community environment. We selected three outcomes-less than three antenatal care visits, home delivery, and neonatal mortality-and used logistic regression and classification and regression tree analysis to test their association with rapidly observable environmental characteristics. We developed a simple triage scorecard and tested its utility as a means of assessing maternal and newborn health risk. In analyses on a sample of 10,754 births, we found associations of health vulnerability with inadequate access to water, toilets, and electricity; non-durable housing; hazardous location; and rental tenancy. A simple scorecard based on these had limited sensitivity and positive predictive value, but relatively high specificity and negative predictive value. The scorecard needs further testing in a range of urban contexts, but we intend to use it to identify informal settlements in particular need of family health interventions in a subsequent program.

Rapid and simple detection of foot-and-mouth disease virus: Evaluation of a cartridge-based molecular detection system for use in basic laboratories.

PubMed

Goller, K V; Dill, V; Madi, M; Martin, P; Van der Stede, Y; Vandenberge, V; Haas, B; Van Borm, S; Koenen, F; Kasanga, C J; Ndusilo, N; Beer, M; Liu, L; Mioulet, V; Armson, B; King, D P; Fowler, V L

2018-04-01

Highly contagious transboundary animal diseases such as foot-and-mouth disease (FMD) are major threats to the productivity of farm animals. To limit the impact of outbreaks and to take efficient steps towards a timely control and eradication of the disease, rapid and reliable diagnostic systems are of utmost importance. Confirmatory diagnostic assays are typically performed by experienced operators in specialized laboratories, and access to this capability is often limited in the developing countries with the highest disease burden. Advances in molecular technologies allow implementation of modern and reliable techniques for quick and simple pathogen detection either in basic laboratories or even at the pen-side. Here, we report on a study to evaluate a fully automated cartridge-based real-time RT-PCR diagnostic system (Enigma MiniLab ® ) for the detection of FMD virus (FMDV). The modular system integrates both nucleic acid extraction and downstream real-time RT-PCR (rRT-PCR). The analytical sensitivity of this assay was determined using serially diluted culture grown FMDV, and the performance of the assay was evaluated using a selected range of FMDV positive and negative clinical samples of bovine, porcine and ovine origin. The robustness of the assay was evaluated in an international inter-laboratory proficiency test and by deployment into an African laboratory. It was demonstrated that the system is easy to use and can detect FMDV with high sensitivity and specificity, roughly on par with standard laboratory methods. This cartridge-based automated real-time RT-PCR system for the detection of FMDV represents a reliable and easy to use diagnostic tool for the early and rapid disease detection of acutely infected animals even in remote areas. This type of system could be easily deployed for routine surveillance within endemic regions such as Africa or could alternatively be used in the developed world. © 2017 The Authors. Transboundary and Emerging Diseases Published by Blackwell Verlag GmbH.

Rapid isothermal detection of Phytophthora species on plant samples using recombinase polymerase amplification

USDA-ARS?s Scientific Manuscript database

Recently several isothermal amplification techniques have been developed that are extremely tolerant towards inhibitors present in many plant extracts. Recombinase polymerase amplification (RPA) assays for the genus Phytophthora have been developed which provide a simple and rapid method to macerate...

Rapid, Selection-Free, High-Efficiency Genome Editing in Protozoan Parasites Using CRISPR-Cas9 Ribonucleoproteins.

PubMed

Soares Medeiros, Lia Carolina; South, Lilith; Peng, Duo; Bustamante, Juan M; Wang, Wei; Bunkofske, Molly; Perumal, Natasha; Sanchez-Valdez, Fernando; Tarleton, Rick L

2017-11-07

Trypanosomatids (order Kinetoplastida), including the human pathogens Trypanosoma cruzi (agent of Chagas disease), Trypanosoma brucei , (African sleeping sickness), and Leishmania (leishmaniasis), affect millions of people and animals globally. T. cruzi is considered one of the least studied and most poorly understood tropical disease-causing parasites, in part because of the relative lack of facile genetic engineering tools. This situation has improved recently through the application of clustered regularly interspaced short palindromic repeats-CRISPR-associated protein 9 (CRISPR-Cas9) technology, but a number of limitations remain, including the toxicity of continuous Cas9 expression and the long drug marker selection times. In this study, we show that the delivery of ribonucleoprotein (RNP) complexes composed of recombinant Cas9 from Staphylococcus aureus (SaCas9), but not from the more routinely used Streptococcus pyogenes Cas9 (SpCas9), and in vitro -transcribed single guide RNAs (sgRNAs) results in rapid gene edits in T. cruzi and other kinetoplastids at frequencies approaching 100%. The highly efficient genome editing via SaCas9/sgRNA RNPs was obtained for both reporter and endogenous genes and observed in multiple parasite life cycle stages in various strains of T. cruzi , as well as in T. brucei and Leishmania major RNP complex delivery was also used to successfully tag proteins at endogenous loci and to assess the biological functions of essential genes. Thus, the use of SaCas9 RNP complexes for gene editing in kinetoplastids provides a simple, rapid, and cloning- and selection-free method to assess gene function in these important human pathogens. IMPORTANCE Protozoan parasites remain some of the highest-impact human and animal pathogens, with very limited treatment and prevention options. The development of improved therapeutics and vaccines depends on a better understanding of the unique biology of these organisms, and understanding their biology, in turn, requires the ability to track and manipulate the products of genes. In this work, we describe new methods that are available to essentially any laboratory and applicable to any parasite isolate for easily and rapidly editing the genomes of kinetoplastid parasites. We demonstrate that these methods provide the means to quickly assess function, including that of the products of essential genes and potential targets of drugs, and to tag gene products at their endogenous loci. This is all achieved without gene cloning or drug selection. We expect this advance to enable investigations, especially in Trypanosoma cruzi and Leishmania spp., that have eluded investigators for decades. Copyright © 2017 Soares Medeiros et al.

A Novel Technique for Detecting Antibiotic-Resistant Typhoid from Rapid Diagnostic Tests

PubMed Central

Nic Fhogartaigh, Caoimhe; Dance, David A. B.; Davong, Viengmon; Tann, Pisey; Phetsouvanh, Rattanaphone; Turner, Paul; Newton, Paul N.

2015-01-01

Fluoroquinolone-resistant typhoid is increasing. An antigen-detecting rapid diagnotic test (RDT) can rapidly diagnose typhoid from blood cultures. A simple, inexpensive molecular technique performed with DNA from positive RDTs accurately identified gyrA mutations consistent with phenotypic susceptibility testing results. Field diagnosis combined with centralized molecular resistance testing could improve typhoid management and surveillance in low-resource settings. PMID:25762768

Isolation of phage-display library-derived scFv antibody specific to Listeria monocytogenes by a novel immobilized method.

PubMed

Nguyen, X-H; Trinh, T-L; Vu, T-B-H; Le, Q-H; To, K-A

2018-02-01

To select Listeria monocytogenes-specific single-chain fragment variable (scFv) antibodies from a phage-display library by a novel simple and cost-effective immobilization method. Light expanded clay aggregate (LECA) was used as biomass support matrix for biopanning of a phage-display library to select L. monocytogenes-specific scFv antibody. Four rounds of positive selection against LECA-immobilized L. monocytogenes and an additional subtractive panning against Listeria innocua were performed. The phage clones selected using this panning scheme and LECA-based immobilization method exhibited the ability to bind L. monocytogenes without cross-reactivity toward 10 other non-L. monocytogenes bacteria. One of the selected phage clones was able to specifically recognize three major pathogenic serotypes (1/2a, 1/2b and 4b) of L. monocytogenes and 11 tested L. monocytogenes strains isolated from foods. The LECA-based immobilization method is applicable for isolating species-specific anti-L. monocytogenes scFv antibodies by phage display. The isolated scFv antibody has potential use in development of immunoassay-based methods for rapid detection of L. monocytogenes in food and environmental samples. In addition, the LECA immobilization method described here could feasibly be employed to isolate specific monoclonal antibodies against any given species of pathogenic bacteria from phage-display libraries. © 2017 The Society for Applied Microbiology.

Rapid screening for Schistosoma mansoni in western Côte d'Ivoire using a simple school questionnaire.

PubMed Central

Utzinger, J.; N'Goran, E. K.; Ossey, Y. A.; Booth, M.; Traoré, M.; Lohourignon, K. L.; Allangba, A.; Ahiba, L. A.; Tanner, M.; Lengeler, C.

2000-01-01

The distribution of schistosomiasis is focal, so if the resources available for control are to be used most effectively, they need to be directed towards the individuals and/or communities at highest risk of morbidity from schistosomiasis. Rapid and inexpensive ways of doing this are needed, such as simple school questionnaires. The present study used such questionnaires in an area of western Côte d'Ivoire where Schistosoma mansoni is endemic; correctly completed questionnaires were returned from 121 out of 134 schools (90.3%), with 12,227 children interviewed individually. The presence of S. mansoni was verified by microscopic examination in 60 randomly selected schools, where 5047 schoolchildren provided two consecutive stool samples for Kato-Katz thick smears. For all samples it was found that 54.4% of individuals were infected with S. mansoni. Moreover, individuals infected with S. mansoni reported "bloody diarrhoea", "blood in stools" and "schistosomiasis" significantly more often than uninfected children. At the school level, Spearman rank correlation analysis showed that the prevalence of S. mansoni significantly correlated with the prevalence of reported bloody diarrhoea (P = 0.002), reported blood in stools (P = 0.014) and reported schistosomiasis (P = 0.011). Reported bloody diarrhoea and reported blood in stools had the best diagnostic performance (sensitivity: 88.2%, specificity: 57.7%, positive predictive value: 73.2%, negative predictive value: 78.9%). The study, which is probably the largest of its kind ever undertaken in Africa, revealed a moderate diagnostic performance of questionnaires for identifying individuals and/or communities at high risk from S. mansoni. PMID:10812739

Development and validation of a rapid LC-MS/MS method for simultaneous determination of netupitant and palonosetron in human plasma and its application to a pharmacokinetic study.

PubMed

Xu, Mingzhen; Ni, Yang; Li, Shihong; Du, Juan; Li, Huqun; Zhou, Ying; Li, Weiyong; Chen, Hui

2016-08-01

A simple liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was firstly developed and validated for simultaneous determination of netupitant and palonosetron in human plasma using ibrutinib as the internal standard (IS). Following liquid-liquid extraction, the compounds were eluted isocratically on a Phenomenex C18 column (50mm×2.0mm, 3μm) with the mobile phase consisting of acetonitrile and 10mM ammonium acetate buffer (pH 9.0) (89:11, v/v) at the flow rate of 0.3mL/min. The monitored ion transitions were m/z 579.5→522.4 for netupitant, m/z 297.3→110.2 for palonosetron and m/z 441.2→138.1 for IS. Chromatographic run time was 2.5min per injection, which made it possible to analyze more than 300 of samples per day. The assay exhibited a linear dynamic range of 5-1000ng/mL for netupitant and 0.02-10ng/mL for palonosetron in plasma. The values for both within- and between-day precision and accuracy were well within the generally accepted criteria for analytical methods (<15%). Selectivity, linearity, lower limit of quantification (LLOQ), accuracy, precision, stability, matrix effect, recovery and carry-over effect were evaluated for all analytes. The method is simple, rapid, and has been applied successfully to a pharmacokinetic study of netupitant and palonosetron in healthy volunteers. Copyright © 2016 Elsevier B.V. All rights reserved.

Positive feedback in the transition from sexual reproduction to parthenogenesis.

PubMed

Schwander, Tanja; Vuilleumier, Séverine; Dubman, Janie; Crespi, Bernard J

2010-05-07

Understanding how new phenotypes evolve is challenging because intermediate stages in transitions from ancestral to derived phenotypes often remain elusive. Here we describe and evaluate a new mechanism facilitating the transition from sexual reproduction to parthenogenesis. In many sexually reproducing species, a small proportion of unfertilized eggs can hatch spontaneously ('tychoparthenogenesis') and develop into females. Using an analytical model, we show that if females are mate-limited, tychoparthenogenesis can result in the loss of males through a positive feedback mechanism whereby tychoparthenogenesis generates female-biased sex ratios and increasing mate limitation. As a result, the strength of selection for tychoparthenogenesis increases in concert with the proportion of tychoparthenogenetic offspring in the sexual population. We then tested the hypothesis that mate limitation selects for tychoparthenogenesis and generates female-biased sex ratios, using data from natural populations of sexually reproducing Timema stick insects. Across 41 populations, both the tychoparthenogenesis rates and the proportions of females increased exponentially as the density of individuals decreased, consistent with the idea that low densities of individuals result in mate limitation and selection for reproductive insurance through tychoparthenogenesis. Our model and data from Timema populations provide evidence for a simple mechanism through which parthenogenesis can evolve rapidly in a sexual population.

Ion Trapping with Fast-Response Ion-Selective Microelectrodes Enhances Detection of Extracellular Ion Channel Gradients

PubMed Central

Messerli, Mark A.; Collis, Leon P.; Smith, Peter J.S.

2009-01-01

Previously, functional mapping of channels has been achieved by measuring the passage of net charge and of specific ions with electrophysiological and intracellular fluorescence imaging techniques. However, functional mapping of ion channels using extracellular ion-selective microelectrodes has distinct advantages over the former methods. We have developed this method through measurement of extracellular K+ gradients caused by efflux through Ca2+-activated K+ channels expressed in Chinese hamster ovary cells. We report that electrodes constructed with short columns of a mechanically stable K+-selective liquid membrane respond quickly and measure changes in local [K+] consistent with a diffusion model. When used in close proximity to the plasma membrane (<4 μm), the ISMs pose a barrier to simple diffusion, creating an ion trap. The ion trap amplifies the local change in [K+] without dramatically changing the rise or fall time of the [K+] profile. Measurement of extracellular K+ gradients from activated rSlo channels shows that rapid events, 10–55 ms, can be characterized. This method provides a noninvasive means for functional mapping of channel location and density as well as for characterizing the properties of ion channels in the plasma membrane. PMID:19217875

A Portable Smart-Phone Readout Device for the Detection of Mercury Contamination Based on an Aptamer-Assay Nanosensor.

PubMed

Xiao, Wei; Xiao, Meng; Fu, Qiangqiang; Yu, Shiting; Shen, Haicong; Bian, Hongfen; Tang, Yong

2016-11-08

The detection of environmental mercury (Hg) contamination requires complex and expensive instruments and professional technicians. We present a simple, sensitive, and portable Hg 2+ detection system based on a smartphone and colorimetric aptamer nanosensor. A smartphone equipped with a light meter app was used to detect, record, and process signals from a smartphone-based microwell reader (MR S-phone), which is composed of a simple light source and a miniaturized assay platform. The colorimetric readout of the aptamer nanosensor is based on a specific interaction between the selected aptamer and Hg 2+ , which leads to a color change in the reaction solution due to an aggregation of gold nanoparticles (AuNPs). The MR S-phone-based AuNPs-aptamer colorimetric sensor system could reliably detect Hg 2+ in both tap water and Pearl River water samples and produced a linear colorimetric readout of Hg 2+ concentration in the range of 1 ng/mL-32 ng/mL with a correlation of 0.991, and a limit of detection (LOD) of 0.28 ng/mL for Hg 2+ . The detection could be quickly completed in only 20 min. Our novel mercury detection assay is simple, rapid, and sensitive, and it provides new strategies for the on-site detection of mercury contamination in any environment.

A Portable Smart-Phone Readout Device for the Detection of Mercury Contamination Based on an Aptamer-Assay Nanosensor

PubMed Central

Xiao, Wei; Xiao, Meng; Fu, Qiangqiang; Yu, Shiting; Shen, Haicong; Bian, Hongfen; Tang, Yong

2016-01-01

The detection of environmental mercury (Hg) contamination requires complex and expensive instruments and professional technicians. We present a simple, sensitive, and portable Hg2+ detection system based on a smartphone and colorimetric aptamer nanosensor. A smartphone equipped with a light meter app was used to detect, record, and process signals from a smartphone-based microwell reader (MR S-phone), which is composed of a simple light source and a miniaturized assay platform. The colorimetric readout of the aptamer nanosensor is based on a specific interaction between the selected aptamer and Hg2+, which leads to a color change in the reaction solution due to an aggregation of gold nanoparticles (AuNPs). The MR S-phone-based AuNPs-aptamer colorimetric sensor system could reliably detect Hg2+ in both tap water and Pearl River water samples and produced a linear colorimetric readout of Hg2+ concentration in the range of 1 ng/mL–32 ng/mL with a correlation of 0.991, and a limit of detection (LOD) of 0.28 ng/mL for Hg2+. The detection could be quickly completed in only 20 min. Our novel mercury detection assay is simple, rapid, and sensitive, and it provides new strategies for the on-site detection of mercury contamination in any environment. PMID:27834794

Detection of Cucurbit chlorotic yellows virus from Bemisia tabaci captured on sticky traps using reverse transcription loop-mediated isothermal amplification (RT-LAMP) and simple template preparation.

PubMed

Okuda, Mitsuru; Okuda, Shiori; Iwai, Hisashi

2015-09-01

Cucurbit chlorotic yellows virus (CCYV) of the genus Crinivirus within the family Closteroviridae is an emerging infectious agent of cucurbits leading to severe disease and significant economic losses. Effective detection and identification methods for this virus are urgently required. In this study, a reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed to detect CCYV from its vector Bemisia tabaci. LAMP primer sets to detect CCYV were evaluated for their sensitivity and specificity, and a primer set designed from the HSP70h gene with corresponding loop primers were selected. The RT-LAMP assay was applied to detect CCYV from viruliferous B. tabaci trapped on sticky traps. A simple extraction procedure using RNAsecure™ was developed for template preparation. CCYV was detected in all of the B. tabaci 0, 1, 7 and 14 days after they were trapped. Although the rise of turbidity was delayed in reactions using RNA from B. tabaci trapped for 7 and 14 days compared with those from 0 and 1 day, the DNA amplification was sufficient to detect CCYV in all of the samples. These findings therefore present a simple template preparation method and an effective RT-LAMP assay, which can be easily and rapidly performed to monitor CCYV-viruliferous B. tabaci in the field. Copyright © 2015 Elsevier B.V. All rights reserved.

Simple & Rapid Generation of Complex DNA Profiles for the Undergraduate Laboratory

ERIC Educational Resources Information Center

Kass, David H.

2007-01-01

Deoxyribonucleic acid (DNA) profiles can be generated by a variety of techniques incorporating different types of DNA markers. Simple methods are commonly utilized in the undergraduate laboratory, but with certain drawbacks. In this article, the author presents an advancement of the "Alu" dimorphism technique involving two tetraplex polymerase…

Simple sequence repeat markers that identify Claviceps species and strains

USDA-ARS?s Scientific Manuscript database

Claviceps purpurea is a pathogen that infects most members of the Pooideae subfamily and causes ergot, a floral disease in which the ovary is replaced with a sclerotium. This study was initiated to develop Simple Sequence Repeat (SSRs) markers for rapid identification of C. purpurea. SSRs were desi...

SIMPLE MINI-METHOD TO EXTRACT BULK DNA DIRECTLY FROM SOIL FOR USE WITH PCR

EPA Science Inventory

A rapid, simple method is described, which yields amplifiable bacterial and fungal DNAs from soil. NA is extracted directly from soil and separated from the soil contaminants by electrophoresis in Nusieve GTG agarose. p to fifty 20 mg samples can be processed in one day.

A simple and rapid method for preparing the whole section of starchy seed to investigate the morphology and distribution of starch in different regions of seed.

PubMed

Zhao, Lingxiao; Pan, Ting; Guo, Dongwei; Wei, Cunxu

2018-01-01

Storage starch in starchy seed influences the seed weight and texture, and determines its applications in food and nonfood industries. Starch granules from different plant sources have significantly different shapes and sizes, and even more the difference exists in the different regions of the same tissue. Therefore, it is very important to in situ investigate the morphology and distribution of starch in the whole seed. However, a simple and rapid method is deficient to prepare the whole section of starchy seed for investigating the morphology and distribution of starch in the whole seeds for a large number of samples. A simple and rapid method was established to prepare the whole section of starchy seed, especially for floury seed, in this study. The whole seeds of translucent and chalky rice, vitreous and floury maize, and normal barley and wheat were sectioned successfully using the newly established method. The iodine-stained section clearly exhibited the shapes and size of starch granules in different regions of seed. The starch granules with different morphologies and iodine-staining colors existed regionally in the seeds of high-amylose rice and maize. The sections of lotus and kidney bean seeds also showed the feasibility of this method for starchy non-cereal seeds. The simple and rapid method was proven effective for preparing the whole sections of starchy seeds. The whole section of seed could be used to investigate the morphology and distribution of starch granules in different regions of the whole seed. The method was especially suitable for large sample numbers to investigate the starch morphology in short time.

One-step sonochemical synthesis of 1D β-stannous tungstate nanorods: An efficient and excellent electrocatalyst for the selective electrochemical detection of antipsychotic drug chlorpromazine.

PubMed

Kokulnathan, Thangavelu; Kumar, Jeyaraj Vinoth; Chen, Shen-Ming; Karthik, Raj; Elangovan, Arumugam; Muthuraj, Velluchamy

2018-06-01

In the modern world, the contamination of ecosystem by human and veterinary pharmaceutical drugs through the metabolic excretion, improper disposal/industrial waste has been subjected to a hot issue. Therefore, exploitation of exclusive structured material and reliable technique is a necessary task to the precise detection of drugs. With this regards, we made an effort for the fabrication of novel one-dimensional (1D) stannous tungstate nanorods (β-SnW NRs) via simple sonochemical approach and used as an electrochemical sensor for the detection of antipsychotic drug chlorpromazine (CPZ) for the first time. The crystallographic structure, surface topology, elemental compositions and their distributions and ionic states were enquired by different spectroscopic techniques such as XRD, FTIR, SEM, EDS, elemental mapping and XPS analysis. The developed β-SnW NRs/GCE sensor exhibits a rapid and sensitive electrochemical response towards CPZ sensing with wide linear response range (0.01-457 µM), high sensitivity (2.487 µA µM -1  cm -2 ), low detection limit (0.003 µM) and excellent selectivity. Besides, the as-proposed electrochemical sensor was successfully applied to real sample analysis in commercial CPZ drug and biological fluids and the acquired recovery results are quite satisfactory. The proposed sonochemical method for the preparation of β-SnW NRs is low cost, very simple, fast and efficient for sensor applications. Copyright © 2018 Elsevier B.V. All rights reserved.

Visual detection of copper(II) ions in blood samples by controlling the leaching of protein-capped gold nanoparticles.

PubMed

Lee, Yen-Fei; Deng, Ting-Wei; Chiu, Wei-Jane; Wei, Tsao-Yen; Roy, Prathik; Huang, Chih-Ching

2012-04-21

We have developed a simple, low-cost, paper-based probe for the selective colorimetric detection of copper ions (Cu(2+)) in aqueous solutions. The bovine serum albumin (BSA)-modified 13.3-nm Au nanoparticle (BSA-Au NP) probe was designed to detect Cu(2+) ions using lead ions (Pb(2+)) and 2-mercaptoethanol (2-ME) as leaching agents in a glycine-NaOH (pH 12.0) solution. In addition, a nitrocellulose membrane (NCM) was used to trap the BSA-Au NPs, leading to the preparation of a nanocomposite film consisting of a BSA-Au NP-decorated membrane (BSA-Au NPs/NCM). The BSA-Au NPs probe operates on the principle that Cu deposition on the surface of the BSA-Au NPs inhibits their leaching ability, which is accelerated by Pb(2+) ions in the presence of 2-ME. Under optimal solution conditions (5 mM glycine-NaOH (pH 12.0), Pb(2+) (50 μM), and 2-ME (1.0 M)), the Pb(2+)/2-ME-BSA-Au NPs/NCM enabled the detection of Cu(2+) at nanomolar concentrations in aqueous solutions by the naked eye with high selectivity (at least 100-fold over other metal ions). In addition, this cost-effective probe allowed for the rapid and simple determination of Cu(2+) ions in not only natural water samples but also in a complex biological sample (in this case, blood sample).

Magnetically assisted surface-enhanced raman scattering selective determination of dopamine in an artificial cerebrospinal fluid and a mouse striatum using Fe(3)O(4)/Ag nanocomposite.

PubMed

Ranc, Vaclav; Markova, Zdenka; Hajduch, Marian; Prucek, Robert; Kvitek, Libor; Kaslik, Josef; Safarova, Klara; Zboril, Radek

2014-03-18

The dopaminergic neural system is a crucial part of the brain responsible for many of its functions including mood, arousal, and other roles. Dopamine is the key neurotransmitter of this system, and a determination of its level presents a demanding task needed for a deeper understanding of the processes, even pathological, involving this brain part. In this work, we present a method for a fast analysis of dopamine levels in samples of cerebrospinal fluid and mouse striatum. The method is based on a nanocomposite composed of magnetite and silver nanoparticles, whose surface is modified with iron nitriloacetic acid (Fe-NTA)-a dopamine-selective compound. The magnetic properties of this nanocomposite enable simple separation of targeted molecules from a complex matrix while the silver acts as a platform for surface-enhanced Raman scattering (SERS). Silver and magnetite nanoparticles are joined by carboxymethyl chitosan, useful in biological environments and enhancing the sensitivity due to the presence of carboxyl groups. This system reveals a good stability and reproducibility. Moreover, rapid and simple quantitative experiments show an improvement in the detection of dopamine levels in biological assays at low femtomolar concentrations. The comparative data performed with clinical samples of mouse striatum show that the developed magnetic SERS is a strong alternative to conventional high-performance liquid chromatography-mass spectrometry (HPLC-MS) with even several superior aspects including faster and cheaper analysis and no necessity of sample preconcentration or derivatization.

Rapid determination of Swiss cheese composition by Fourier transform infrared/attenuated total reflectance spectroscopy.

PubMed

Rodriguez-Saona, L E; Koca, N; Harper, W J; Alvarez, V B

2006-05-01

There is a need for rapid and simple techniques that can be used to predict the quality of cheese. The aim of this research was to develop a simple and rapid screening tool for monitoring Swiss cheese composition by using Fourier transform infrared spectroscopy. Twenty Swiss cheese samples from different manufacturers and degree of maturity were evaluated. Direct measurements of Swiss cheese slices (approximately 0.5 g) were made using a MIRacle 3-reflection diamond attenuated total reflectance (ATR) accessory. Reference methods for moisture (vacuum oven), protein content (Kjeldahl), and fat (Babcock) were used. Calibration models were developed based on a cross-validated (leave-one-out approach) partial least squares regression. The information-rich infrared spectral range for Swiss cheese samples was from 3,000 to 2,800 cm(-1) and 1,800 to 900 cm(-1). The performance statistics for cross-validated models gave estimates for standard error of cross-validation of 0.45, 0.25, and 0.21% for moisture, protein, and fat respectively, and correlation coefficients r > 0.96. Furthermore, the ATR infrared protocol allowed for the classification of cheeses according to manufacturer and aging based on unique spectral information, especially of carbonyl groups, probably due to their distinctive lipid composition. Attenuated total reflectance infrared spectroscopy allowed for the rapid (approximately 3-min analysis time) and accurate analysis of the composition of Swiss cheese. This technique could contribute to the development of simple and rapid protocols for monitoring complex biochemical changes, and predicting the final quality of the cheese.

Copper Ion Detection in Drinking Water via a Fabric Nanocomposite Sensor

NASA Astrophysics Data System (ADS)

Yu, Guoqiang

Excessive Cu(II) ions in drinking water are always a big threat to people's health. In this work, we developed a flexible amperometric sensor by a simple dip-coating method, which was able to rapidly, sensitively, and selectively detect the Cu(II) ions in the range of 0.65 to 39 ppm in real time. The prepared Cu(II) sensor consisted of three layers that were electrospun nylon-6 nanofibers, multiwalled carbon nanotubes (MWCNTs), and 2,2':5',2''-terthiophene molecules, respectively. When a voltage was applied to the Cu(II) sensor, the current was obviously impeded in the presence of Cu(II) ions. Interfering metal ions, including Cd(II), Fe(II), Pb(II), Hg(II), and Ag(I) ions, had almost no influence on the responsiveness of the Cu(II) sensor.

Glutathione-Capped Gold Nanoparticles-Based Photoacoustic Sensor for Label-Free Detection of Lead Ions

NASA Astrophysics Data System (ADS)

Shi, R.; Liu, X.-J.; Ying, Y.

2017-07-01

The photoacoustic signal generated by laser-induced nanobubbles (PA-LINB) proved to be a sensitive tool to monitor the aggregation of gold nanoparticles. Here, a simple and label-free photoacoustic method for the rapid detection of Pb2+ in the aqueous phase was developed. Due to the high affinity of Pb2+ ions to glutathione, the presence of Pb2+ led to the aggregation of glutathione-conjugated gold nanoparticles (GSH-GNPs). Hence, by measuring the variation of the PA-LINB signal after the aggregation of GSH-GNPs, Pb2+ can be quantified. A low detection limit for Pb2+ (42 nM) and a wide linear working range ( 42-1000 nM) were achieved. Furthermore, the proposed method showed good selectivity against other metal ions.

Label-assisted mass spectrometry for the acceleration of reaction discovery and optimization

NASA Astrophysics Data System (ADS)

Cabrera-Pardo, Jaime R.; Chai, David I.; Liu, Song; Mrksich, Milan; Kozmin, Sergey A.

2013-05-01

The identification of new reactions expands our knowledge of chemical reactivity and enables new synthetic applications. Accelerating the pace of this discovery process remains challenging. We describe a highly effective and simple platform for screening a large number of potential chemical reactions in order to discover and optimize previously unknown catalytic transformations, thereby revealing new chemical reactivity. Our strategy is based on labelling one of the reactants with a polyaromatic chemical tag, which selectively undergoes a photoionization/desorption process upon laser irradiation, without the assistance of an external matrix, and enables rapid mass spectrometric detection of any products originating from such labelled reactants in complex reaction mixtures without any chromatographic separation. This method was successfully used for high-throughput discovery and subsequent optimization of two previously unknown benzannulation reactions.

Method utilizing laser-processing for the growth of epitaxial p-n junctions

DOEpatents

Young, R.T.; Narayan, J.; Wood, R.F.

1979-11-23

This invention is a new method for the formation of epitaxial p-n junctions in silicon. The method is relatively simple, rapid, and reliable. It produces doped epitaxial layers which are of well-controlled thickness and whose electrical properties are satisfactory. An illustrative form of the method comprises co-depositing a selected dopant and amorphous silicon on a crystalline silicon substrate to form a doped layer of amorphous silicon thereon. This layer then is irradiated with at least one laser pulse to generate a melt front which moves through the layer, into the silicon body to a depth effecting melting of virginal silicon, and back to the surface of the layer. The method may be conducted with dopants (e.g., boron and phosphorus) whose distribution coefficients approximate unity.

Microwave-assisted synthesis of HKUST-1 and functionalized HKUST-1-@H3PW12O40: selective adsorption of heavy metal ions in water analyzed with synchrotron radiation.

PubMed

Zou, Fang; Yu, Runhan; Li, Rongguan; Li, Wei

2013-08-26

A simple, rapid and efficient synthesis of the metal-organic framework (MOF) HKUST-1 [Cu3(1,3,5-benzene-tri-carboxilic-acid)2] by microwave irradiation is described, which afforded a homogeneous and highly selective material. The unusually short time to complete the synthesis by microwave irradiation is mainly attributable to rapid nucleation rather than to crystal growth rate. Using this method, HKUST-1-MW (MW=microwave) could be prepared within 20 min, whereas by hydrothermal synthesis, involving conventional heating, the preparation time is 8 h. Work efficiency was improved by the good performance of the obtained HKUST-1-MW which exhibited good selective adsorption of heavy metal ions, as well as a remarkably high adsorption affinity and adsorption capacity, but no adsorption of Hg(2+) under the same experimental conditions. Of particular importance is the preservation of the structure after metal-ion adsorption, which remained virtually intact, with only a few changes in X-ray diffraction intensity and a moderate decline in surface area. Synthesis of the polyoxometalate-containing HKUST-1-MW@H3PW12O40 afforded a MOF with enhanced stability in water, due to the introduced Keggin-type phosphotungstate, which systematically occluded in the cavities constituting the walls between the mesopores. Different Cu/W ratios were investigated according to the extrusion rate of cooper ions concentration, without significant structural changes after adsorption. The MOFs obtained feature particle sizes between 10-20 μm and their structures were determined using synchrotron-based X-ray diffraction. The results of this study can be considered important for potentially wider future applications of MOFs, especially to attend environmental issues. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Item Selection, Evaluation, and Simple Structure in Personality Data

PubMed Central

Pettersson, Erik; Turkheimer, Eric

2010-01-01

We report an investigation of the genesis and interpretation of simple structure in personality data using two very different self-reported data sets. The first consists of a set of relatively unselected lexical descriptors, whereas the second is based on responses to a carefully constructed instrument. In both data sets, we explore the degree of simple structure by comparing factor solutions to solutions from simulated data constructed to have either strong or weak simple structure. The analysis demonstrates that there is little evidence of simple structure in the unselected items, and a moderate degree among the selected items. In both instruments, however, much of the simple structure that could be observed originated in a strong dimension of positive vs. negative evaluation. PMID:20694168

A quick method based on SIMPLISMA-KPLS for simultaneously selecting outlier samples and informative samples for model standardization in near infrared spectroscopy

NASA Astrophysics Data System (ADS)

Li, Li-Na; Ma, Chang-Ming; Chang, Ming; Zhang, Ren-Cheng

2017-12-01

A novel method based on SIMPLe-to-use Interactive Self-modeling Mixture Analysis (SIMPLISMA) and Kernel Partial Least Square (KPLS), named as SIMPLISMA-KPLS, is proposed in this paper for selection of outlier samples and informative samples simultaneously. It is a quick algorithm used to model standardization (or named as model transfer) in near infrared (NIR) spectroscopy. The NIR experiment data of the corn for analysis of the protein content is introduced to evaluate the proposed method. Piecewise direct standardization (PDS) is employed in model transfer. And the comparison of SIMPLISMA-PDS-KPLS and KS-PDS-KPLS is given in this research by discussion of the prediction accuracy of protein content and calculation speed of each algorithm. The conclusions include that SIMPLISMA-KPLS can be utilized as an alternative sample selection method for model transfer. Although it has similar accuracy to Kennard-Stone (KS), it is different from KS as it employs concentration information in selection program. This means that it ensures analyte information is involved in analysis, and the spectra (X) of the selected samples is interrelated with concentration (y). And it can be used for outlier sample elimination simultaneously by validation of calibration. According to the statistical data results of running time, it is clear that the sample selection process is more rapid when using KPLS. The quick algorithm of SIMPLISMA-KPLS is beneficial to improve the speed of online measurement using NIR spectroscopy.

Rapid and simple procedure for homogenizing leaf tissues suitable for mini-midi-scale DNA extraction in rice.

PubMed

Yi, Gihwan; Choi, Jun-Ho; Lee, Jong-Hee; Jeong, Unggi; Nam, Min-Hee; Yun, Doh-Won; Eun, Moo-Young

2005-01-01

We describe a rapid and simple procedure for homogenizing leaf samples suitable for mini/midi-scale DNA preparation in rice. The methods used tungsten carbide beads and general vortexer for homogenizing leaf samples. In general, two samples can be ground completely within 11.3+/-1.5 sec at one time. Up to 20 samples can be ground at a time using a vortexer attachment. The yields of the DNA ranged from 2.2 to 7.6 microg from 25-150 mg of young fresh leaf tissue. The quality and quantity of DNA was compatible for most of PCR work and RFLP analysis.

SERS-based pesticide detection by using nanofinger sensors

NASA Astrophysics Data System (ADS)

Kim, Ansoon; Barcelo, Steven J.; Li, Zhiyong

2015-01-01

Simple, sensitive, and rapid detection of trace levels of extensively used and highly toxic pesticides are in urgent demand for public health. Surface-enhanced Raman scattering (SERS)-based sensor was designed to achieve ultrasensitive and simple pesticide sensing. We developed a portable sensor system composed of high performance and reliable gold nanofinger sensor strips and a custom-built portable Raman spectrometer. Compared to the general procedure and previously reported studies that are limited to laboratory settings, our analytical method is simple, sensitive, rapid, and cost-effective. Based on the SERS results, the chemical interaction of two pesticides, chlorpyrifos (CPF) and thiabendazole (TBZ), with gold nanofingers was studied to determine a fingerprint for each pesticide. The portable SERS-sensor system was successfully demonstrated to detect CPF and TBZ pesticides within 15 min with a detection limit of 35 ppt in drinking water and 7 ppb on apple skin, respectively.

Probing the Boundaries of Orthology: The Unanticipated Rapid Evolution of Drosophila centrosomin

PubMed Central

Eisman, Robert C.; Kaufman, Thomas C.

2013-01-01

The rapid evolution of essential developmental genes and their protein products is both intriguing and problematic. The rapid evolution of gene products with simple protein folds and a lack of well-characterized functional domains typically result in a low discovery rate of orthologous genes. Additionally, in the absence of orthologs it is difficult to study the processes and mechanisms underlying rapid evolution. In this study, we have investigated the rapid evolution of centrosomin (cnn), an essential gene encoding centrosomal protein isoforms required during syncytial development in Drosophila melanogaster. Until recently the rapid divergence of cnn made identification of orthologs difficult and questionable because Cnn violates many of the assumptions underlying models for protein evolution. To overcome these limitations, we have identified a group of insect orthologs and present conserved features likely to be required for the functions attributed to cnn in D. melanogaster. We also show that the rapid divergence of Cnn isoforms is apparently due to frequent coding sequence indels and an accelerated rate of intronic additions and eliminations. These changes appear to be buffered by multi-exon and multi-reading frame maximum potential ORFs, simple protein folds, and the splicing machinery. These buffering features also occur in other genes in Drosophila and may help prevent potentially deleterious mutations due to indels in genes with large coding exons and exon-dense regions separated by small introns. This work promises to be useful for future investigations of cnn and potentially other rapidly evolving genes and proteins. PMID:23749319

The Doppler Pendulum Experiment

ERIC Educational Resources Information Center

Lee, C. K.; Wong, H. K.

2011-01-01

An experiment to verify the Doppler effect of sound waves is described. An ultrasonic source is mounted at the end of a simple pendulum. As the pendulum swings, the rapid change of frequency can be recorded by a stationary receiver using a simple frequency-to-voltage converter. The experimental results are in close agreement with the Doppler…

Quantitation & Case-Study-Driven Inquiry to Enhance Yeast Fermentation Studies

ERIC Educational Resources Information Center

Grammer, Robert T.

2012-01-01

We propose a procedure for the assay of fermentation in yeast in microcentrifuge tubes that is simple and rapid, permitting assay replicates, descriptive statistics, and the preparation of line graphs that indicate reproducibility. Using regression and simple derivatives to determine initial velocities, we suggest methods to compare the effects of…

A simple and rapid radiochemical choline acetyltransferase (ChAT) assay screening test.

PubMed

Shiba, Kazuhiro; Ogawa, Kazuma; Kinuya, Seigo; Yajima, Kazuyoshi; Mori, Hirofumi

2006-10-15

A simple radiochemical choline acetyltransferase (ChAT) assay screening test was developed by measuring for [(3)H]acetylcholine ([(3)H]ACh) formed from 0.2 mM [(3)H]acetyl-coenzyme A ([(3)H]acetyl-CoA) and 1 mM choline by 0.2 mg of rat brain homogenates containing ChAT into 96-well microplates. A simple and rapid procedure for isolating [(3)H]ACh from the incubation mixture into 96-well microplates was achieved by using a sodium tetraphenylboron (Kalibor) solution (in ethyl acetate, 0.75%, w/v) and a hydrophobic liquid scintillator mixture (1:5, v/v, 0.2 mL) as an extraction solvent. The benefits of this radiochemical method using 96-well microplates are as follows: (1) this method is reliable and reproducible; (2) many samples can be examined at the same time by this method; (3) this method is economical and effective in reducing radioactive waste. The development of a new simple radiochemical ChAT assay screening test is the first stage of development of radiolabeled ChAT mapping agent.

Aptamer Selection Express: A Novel Method for Rapid Single-Step Selection and Sensing of Aptamers

PubMed Central

Fan, Maomian; McBurnett, Shelly Roper; Andrews, Carrie J.; Allman, Amity M.; Bruno, John G.; Kiel, Johnathan L.

2008-01-01

Here we describe a new DNA capture element (DCE) sensing system, based on the quenching and dequenching of a double-stranded aptamer. This system shows very good sensitivity and thermal stability. While quenching, dequenching, and separating the DCE systems made from different aptamers (all selected by SELEX), an alternative method to rapidly select aptamers was developed—the Aptamer Selection Express (ASExp). This process has been used to select aptamers against different types of targets (Bacillus anthracis spores, Bacillus thuringiensis spores, MS-2 bacteriophage, ovalbumin, and botulinum neurotoxin). The DCE systems made from botulinum neurotoxin aptamers selected by ASExp have been investigated. The results of this investigation indicate that ASExp can be used to rapidly select aptamers for the DCE sensing system. PMID:19183794

Using lot quality-assurance sampling and area sampling to identify priority areas for trachoma control: Viet Nam.

PubMed Central

Myatt, Mark; Mai, Nguyen Phuong; Quynh, Nguyen Quang; Nga, Nguyen Huy; Tai, Ha Huy; Long, Nguyen Hung; Minh, Tran Hung; Limburg, Hans

2005-01-01

OBJECTIVE: To report on the use of lot quality-assurance sampling (LQAS) surveys undertaken within an area-sampling framework to identify priority areas for intervention with trachoma control activities in Viet Nam. METHODS: The LQAS survey method for the rapid assessment of the prevalence of active trachoma was adapted for use in Viet Nam with the aim of classifying individual communes by the prevalence of active trachoma among children in primary school. School-based sampling was used; school sites to be sampled were selected using an area-sampling approach. A total of 719 communes in 41 districts in 18 provinces were surveyed. FINDINGS: Survey staff found the LQAS survey method both simple and rapid to use after initial problems with area-sampling methods were identified and remedied. The method yielded a finer spatial resolution of prevalence than had been previously achieved in Viet Nam using semiquantitative rapid assessment surveys and multistage cluster-sampled surveys. CONCLUSION: When used with area-sampling techniques, the LQAS survey method has the potential to form the basis of survey instruments that can be used to efficiently target resources for interventions against active trachoma. With additional work, such methods could provide a generally applicable tool for effective programme planning and for the certification of the elimination of trachoma as a blinding disease. PMID:16283052

PrimaTB STAT-PAK Assay, a Novel, Rapid Lateral-Flow Test for Tuberculosis in Nonhuman Primates▿

PubMed Central

Lyashchenko, Konstantin P.; Greenwald, Rena; Esfandiari, Javan; Greenwald, David; Nacy, Carol A.; Gibson, Susan; Didier, Peter J.; Washington, Marc; Szczerba, Peter; Motzel, Sherri; Handt, Larry; Pollock, John M.; McNair, James; Andersen, Peter; Langermans, Jan A. M.; Verreck, Frank; Ervin, Sean; Ervin, Frank; McCombs, Candace

2007-01-01

Tuberculosis (TB) is the most important zoonotic bacterial disease in nonhuman primates (NHP). The current diagnostic method, the intradermal palpebral tuberculin test, has serious shortcomings. We characterized antibody responses in NHP against Mycobacterium tuberculosis to identify immunodominant antigens and develop a rapid serodiagnostic test for TB. A total of 422 NHP were evaluated, including 243 rhesus (Macaca mulatta), 46 cynomolgus (Macaca fascicularis), and 133 African green (Cercopithecus aethiops sabaeus) monkeys at five collaborative centers. Of those, 50 monkeys of the three species were experimentally inoculated with M. tuberculosis. Antibody responses were monitored every 2 to 4 weeks for up to 8 months postinfection by MultiAntigen Print ImmunoAssay with a panel of 12 recombinant antigens. All of the infected monkeys produced antibodies at various levels and with different antigen recognition patterns. ESAT-6 and MPB83 were the most frequently recognized proteins during infection. A combination of selected antigens which detected antibodies in all of the infected monkeys was designed to develop the PrimaTB STAT-PAK assay by lateral-flow technology. Serological evaluation demonstrated high diagnostic sensitivity (90%) and specificity (99%). The highest rate of TB detection was achieved when the skin test was combined with the PrimaTB STAT-PAK kit. This novel immunoassay provides a simple, rapid, and accurate test for TB in NHP. PMID:17652522

A rapid, one step preparation for measuring selected free plus SO2-bound wine carbonyls by HPLC-DAD/MS.

PubMed

Han, Guomin; Wang, Hua; Webb, Michael R; Waterhouse, Andrew L

2015-03-01

Carbonyl compounds are produced during fermentation and chemical oxidation during wine making and aging, and they are important to wine flavor and color stability. Since wine also contains these compounds as α-hydroxysulfonates as a result of their reaction with sulfur dioxide, an alkaline pre-treatment requiring oxygen exclusion has been used to release these bound carbonyls for analysis. By modifying the method to hydrolyze the hydroxysulfonates with heating and acid in the presence of 2,4-dinitrophenylhydrazine (DNPH), the carbonyl compounds are simultaneously and quickly released and derivatized, resulting in a simpler and more rapid method. In addition, the method avoids air exclusion complications during hydrolysis by the addition of sulfur dioxide. The method was optimized for temperature, reaction time, and the concentrations of DNPH, sulfur dioxide and acid. The hydrazones were shown to be stable for 10 h, adequate time for chromatographic analysis by HPLC-DAD/MS. This method is demonstrated for 2-ketoglutaric acid, pyruvic acid, acetoin and acetaldehyde, wine carbonyls of very different reactivities, and it offers good specificity, high recovery and low limits of detection. This new rapid, simple method is demonstrated for the measurement of carbonyl compounds in a range of wines of different ages and grape varieties. Copyright © 2014 Elsevier B.V. All rights reserved.

Assignment of the SLA alleles and reproductive potential of selective breeding Duroc pig lines.

PubMed

Soe, Ok Kar; Ohba, Yasunori; Imaeda, Noriaki; Nishii, Naohito; Takasu, Masaki; Yoshioka, Gou; Kawata, Hisako; Shigenari, Atsuko; Uenishi, Hirohide; Inoko, Hidetoshi; Ando, Asako; Kitagawa, Hitoshi

2008-01-01

Pigs with defined swine leukocyte antigen (SLA) haplotypes and their detailed information are useful for transplantation and immunological studies. We developed two herds of SLA homozygous Duroc pigs with novel SLA haplotypes and characterized their reproductive potential. For selective inbreeding, a pair of Duroc pigs was chosen as initial breeders, and substantial breeding within progenies was carried out for eight generations. In the selective breeding Duroc pigs, SLA haplotypes were assigned by nucleotide sequence determination of reverse transcription polymerase chain reaction (RT-PCR) products of three SLA classical class I genes and two class II genes. Based on this sequence information, we developed a rapid and simple SLA class II DNA typing method by polymerase chain reaction-sequence specific primer (PCR-SSP) technique. As a complementary method for the characterization of the SLA haplotypes, genetic polymorphisms of 36 microsatellite (MS) markers within the SLA region were also analyzed in the selective breeding pigs with SLA homozygous/heterozygous haplotypes. Among the selective breeding pigs from the third to fifth generations, only two SLA haplotypes were identified by the RT-PCR based SLA typing method; Hp-27.30 (SLA-1*08an03, SLA-1*06an04, SLA-2*0102, SLA-3*0101 DRB1*1101 and DQB1*0503) and Hp-60.13 (SLA-1*an02, SLA-2*1002, SLA-3*0502, DRB1*0403 and DQB1*0303). In these two SLA haplotypes, two class I haplotypes, Hp-27.0 and Hp-60.0, are novel. Furthermore, two class II haplotypes, Hp-0.30 and Hp-0.13, which were previously reported in Korean native pigs and pigs of Hanford breed, respectively, were also assigned by a simple assay using a PCR-SSP technique in the entire selective breeding stock. Moreover, two haplotype specific MS patterns were observed across the entire SLA region in the selective breeding (homozygous/heterozygous) pigs. No morphological abnormalities were observed in selective breeding pigs. The theoretical inbreeding coefficient at the eighth generation was 78.5%. In all generations of selective breeding pigs, litter sizes were comparable and weaning weights from the fifth to eighth generation produced progenies significantly lighter (P < 0.01) than those in the non-selective breeding pigs. We established and characterized SLA homozygous Duroc herds with two kinds of haplotypes that can be used as a new resource for transplantation and other biomedical studies.

Liquid-phase microextraction for rapid AP-MALDI and quantitation of nortriptyline in biological matrices.

PubMed

Wu, Hui-Fen; Ku, Hsin-Yi; Yen, Jyh-Hao

2008-07-01

A liquid-phase microextraction (LPME) method using a micropipette with disposable tips was demonstrated for coupling to atmospheric pressure MALDI-MS (AP-MALDI/MS) as a concentrating probe for rapid analysis and quantitative determination of nortriptyline drug from biological matrices including human urine and human plasma. This technique was named as micropipette extraction (MPE). The best optimized parameters of MPE coupled to AP-MALDI/MS experiments were extraction solvent, toluene; extraction time, 5 min; sample agitation rate, 480 rpm; sample pH, 7; salt concentration, 30%; hole size of micropipette tips, 0.61 mm (id); and matrix concentration, 1000 ppm using alpha-cyano-4-hydroxycinnamic acid (CHCA) as a matrix. Three detection modes of AP-MALDI/MS analysis including full scan, selective ion monitor (SIM), and selective reaction monitor (SRM) of MS/MS were also compared for the MPE performance. The results clearly demonstrated that the MS/MS method provides a wider linear range and lower LODs but poor RSDs than the full scan and SIM methods. The LOD values for the MPE under SIM and MS/MS modes in water, urine, and plasma were 6.26, 47.5, and 94.9 nM, respectively. The enrichment factors (EFs) of this current approach were 36.5-43.0 fold in water. In addition, compared to single drop microextraction (SDME) and LPME using a dual gauge microsyringe with a hollow fiber (LPME-HF) technique, the LODs acquired by the MPE method under MS/MS modes were comparable to those of LPME-HF and SDME but it is more convenient than both methods. The advantages of this novel method are simple, easy to use, low cost, and no contamination between experiments since disposable tips were used for the micropipettes. The MPE has the potential to be widely used in the future because it only requires a simple micropipette to perform all extraction processes. We believe that this technique can be a powerful tool for MALDI/MS analysis of biological samples and clinical applications.

Building Structure Housing: Case Study of Community Housing in Kendari City

NASA Astrophysics Data System (ADS)

Umar, M. Z.; Faslih, A.; Arsyad, M.; Sjamsu, A. S.; Kadir, I.

2017-11-01

Housing development has been pioneered through a simple home construction program to reduce the production cost. Simple housing program was developed in Kendari City. The purpose of this study is to show the principles of reducing the cost production for the type 36 homes, in Kendari City. The selected architectural objects are the lower, middle and the upper structure of type 36 house. The data collection was done by observation and in-depth discussion with construction workers. The analysis technique used in this research was a descriptive narrative analysis technique in the form of tabulation data. This study concluded that there are several principles of price reduction in the structure of public housing buildings. Quick principles exist in constructing techniques such as using cigarette packs as a foundation pad, mortar usage for rapid wall standing, and the spacing of mortars could be done manually by using two fingers on a human hand. Economic principles could be used for material matters, such as eliminating the use of gravel for concrete, the use of sand material to contain the soil, the foundation does not use sand and empty stone, and the shape of the ring beam was made using triangle reinforcement.

RNA structure in splicing: An evolutionary perspective.

PubMed

Lin, Chien-Ling; Taggart, Allison J; Fairbrother, William G

2016-09-01

Pre-mRNA splicing is a key post-transcriptional regulation process in which introns are excised and exons are ligated together. A novel class of structured intron was recently discovered in fish. Simple expansions of complementary AC and GT dimers at opposite boundaries of an intron were found to form a bridging structure, thereby enforcing correct splice site pairing across the intron. In some fish introns, the RNA structures are strong enough to bypass the need of regulatory protein factors for splicing. Here, we discuss the prevalence and potential functions of highly structured introns. In humans, structured introns usually arise through the co-occurrence of C and G-rich repeats at intron boundaries. We explore the potentially instructive example of the HLA receptor genes. In HLA pre-mRNA, structured introns flank the exons that encode the highly polymorphic β sheet cleft, making the processing of the transcript robust to variants that disrupt splicing factor binding. While selective forces that have shaped HLA receptor are fairly atypical, numerous other highly polymorphic genes that encode receptors contain structured introns. Finally, we discuss how the elevated mutation rate associated with the simple repeats that often compose structured intron can make structured introns themselves rapidly evolving elements.

A novel and simple fluorescence probe for detecting main group magnesium ion in HeLa cells and Arabidopsis.

PubMed

Yu, Tingting; Sun, Ping; Hu, Yijie; Ji, Yinggang; Zhou, Hongping; Zhang, Baowei; Tian, Yupeng; Wu, Jieying

2016-12-15

A simple-molecule fluorescence probe L has been designed, synthesized and characterized, which shows high selectivity and sensitivity for the main group magnesium ion through fluorescence "turn-on" response in ethanol solution, and no interference from calcium ion in particular. Detection limit of probe L is 1.47×10(-6) M and the rapid response could reach about 15-20s. The recognition mechanism has been established by fluorescence spectra, (1)H NMR study. Moreover, probe L presents a great photostability, low toxicity and cellular permeability, then we have carried out fluorescent bio-imaging of the probe L for magnesium ions in HeLa cells, which showed that probe L could be utilized to detect the intracellular magnesium ion. Furthermore, it is successfully used as a magnesium ion developer in plant tissues, which shows that it not only can be well tracking the transport of magnesium ion but also make a corresponding fluorescence response to different concentrations magnesium ion. These results would make this probe a great potential application for detecting Mg(2+) in biological system. Copyright © 2016 Elsevier B.V. All rights reserved.

Metal-Organic Framework Thin Film Coated Optical Fiber Sensors: A Novel Waveguide-Based Chemical Sensing Platform.

PubMed

Kim, Ki-Joong; Lu, Ping; Culp, Jeffrey T; Ohodnicki, Paul R

2018-02-23

Integration of optical fiber with sensitive thin films offers great potential for the realization of novel chemical sensing platforms. In this study, we present a simple design strategy and high performance of nanoporous metal-organic framework (MOF) based optical gas sensors, which enables detection of a wide range of concentrations of small molecules based upon extremely small differences in refractive indices as a function of analyte adsorption within the MOF framework. Thin and compact MOF films can be uniformly formed and tightly bound on the surface of etched optical fiber through a simple solution method which is critical for manufacturability of MOF-based sensor devices. The resulting sensors show high sensitivity/selectivity to CO 2 gas relative to other small gases (H 2 , N 2 , O 2 , and CO) with rapid (

Study on the potential application of salivary inorganic anions in clinical diagnosis by capillary electrophoresis coupled with contactless conductivity detection.

PubMed

Guo, Lin; Wang, Yu; Zheng, Yiliang; Huang, Zhipeng; Cheng, Yiyuan; Ye, Jiannong; Chu, Qingcui; Huang, Dongping

2016-03-01

A capillary electrophoresis approach with capacitively coupled contactless conductivity detection method has been developed for the determination of inorganic metabolites (thiocyanate, nitrite and nitrate) in human saliva. Field amplified sample injection, as a simple sample stacking technique, was used in conjunction for online preconcentration of above inorganic anions. A selective separation for the target anions from other coexisting constituents present in saliva could be obtained within 14min in a 10mmol/L His-90mmol/L HAc buffer (pH 3.70) at the separation voltage of -18kV. The limits of detection and limits of quantification of the three analytes were within the range of 3.1-4.9ng/mL (S/N=3) and 10-16ng/mL (S/N=10), respectively. The average recovery data were in the range of 81-108% at three different concentrations. This method provides a simple, rapid and direct approach for metabolite analyses of nitric oxide and cyanide based on noninvasive saliva sample, which presents a potential fast screening tool for clinical test. Copyright © 2016 Elsevier B.V. All rights reserved.

Development of a POC Test for TB Based on Multiple Immunodominant Epitopes of M. tuberculosis Specific Cell-Wall Proteins

PubMed Central

Gonzalez, Jesus M.; Francis, Bryan; Burda, Sherri; Hess, Kaitlyn; Behera, Digamber; Gupta, Dheeraj; Agarwal, Ashutosh Nath; Verma, Indu; Verma, Ajoy; Myneedu, Vithal Prasad; Niedbala, Sam; Laal, Suman

2014-01-01

The need for an accurate, rapid, simple and affordable point-of-care (POC) test for Tuberculosis (TB) that can be implemented in microscopy centers and other peripheral health-care settings in the TB-endemic countries remains unmet. This manuscript describes preliminary results of a new prototype rapid lateral flow TB test based on detection of antibodies to immunodominant epitopes (peptides) derived from carefully selected, highly immunogenic M. tuberculosis cell-wall proteins. Peptide selection was initially based on recognition by antibodies in sera from TB patients but not in PPD-/PPD+/BCG-vaccinated individuals from TB-endemic settings. The peptides were conjugated to BSA; the purified peptide-BSA conjugates striped onto nitrocellulose membrane and adsorbed onto colloidal gold particles to devise the prototype test, and evaluated for reactivity with sera from 3 PPD-, 29 PPD+, 15 PPD-unknown healthy subjects, 10 patients with non-TB lung disease and 124 smear-positive TB patients. The assay parameters were adjusted to determine positive/negative status within 15 minutes via visual or instrumented assessment. There was minimal or no reactivity of sera from non-TB subjects with the striped BSA-peptides demonstrating the lack of anti-peptide antibodies in subjects with latent TB and/or BCG vaccination. Sera from most TB patients demonstrated reactivity with one or more peptides. The sensitivity of antibody detection ranged from 28–85% with the 9 BSA-peptides. Three peptides were further evaluated with sera from 400 subjects, including additional PPD-/PPD+/PPD-unknown healthy contacts, close hospital contacts and household contacts of untreated TB patients, patients with non-TB lung disease, and HIV+TB- patients. Combination of the 3 peptides provided sensitivity and specificity>90%. While the final fully optimized lateral flow POC test for TB is under development, these preliminary results demonstrate that an antibody-detection based rapid POC lateral flow test based on select combinations of immunodominant M. tb-specific epitopes may potentially replace microscopy for TB diagnosis in TB-endemic settings. PMID:25247820

Persistent enhancement of bacterial motility increases tumor penetration.

PubMed

Thornlow, Dana N; Brackett, Emily L; Gigas, Jonathan M; Van Dessel, Nele; Forbes, Neil S

2015-11-01

Motile bacteria can overcome the transport limitations that hinder many cancer therapies. Active bacteria can penetrate through tissue to deliver treatment to resistant tumor regions. Bacterial therapy has had limited success, however, because this motility is heterogeneous, and within a population many individuals are non-motile. In human trials, heterogeneity led to poor dispersion and incomplete tumor colonization. To address these problems, a swarm-plate selection method was developed to increase swimming velocity. Video microscopy was used to measure the velocity distribution of selected bacteria and a microfluidic tumor-on-a-chip device was used to measure penetration through tumor cell masses. Selection on swarm plates increased average velocity fourfold, from 4.9 to 18.7 μm/s (P < 0.05) and decreased the number of non-motile individuals from 51% to 3% (P < 0.05). The selected phenotype was both robust and stable. Repeating the selection process consistently increased velocity and eliminated non-motile individuals. When selected strains were cryopreserved and subcultured for 30.1 doublings, the high-motility phenotype was preserved. In the microfluidic device, selected Salmonella penetrated deeper into cell masses than unselected controls. By 10 h after inoculation, control bacteria accumulated in the front 30% of cell masses, closest to the flow channel. In contrast, selected Salmonella accumulated in the back 30% of cell masses, farthest from the channel. Selection increased the average penetration distance from 150 to 400 μm (P < 0.05). This technique provides a simple and rapid method to generate high-motility Salmonella that has increased penetration and potential for greater tumor dispersion and clinical efficacy. © 2015 Wiley Periodicals, Inc.

Some new speculative ideas about the “behavioral homeostasis theory” as to how the simple learned behaviors of habituation and sensitization improve organism survival throughout phylogeny

PubMed Central

Eisenstein, Edward M.; Eisenstein, Doris L.; Sarma, Jonnalagedda Sarma M.; Knapp, Herschel; Smith, James C.

2012-01-01

This paper explores further the “behavioral homeostasis theory” (BHT) regarding the evolutionary significance for organism survival of the two simple non-associative rapidly learned behaviors of habituation and sensitization. The BHT postulates that the evolutionary function of habituation and sensitization throughout phylogeny is to rapidly maximize an organism’s overall readiness to cope with new stimuli and to minimize unnecessary energy expenditure. These behaviors have survived with remarkable similarity throughout phylogeny from aneural protozoa to humans. The concept of “behavioral homeostasis” emphasizes that the homeostatic process is more than just maintaining internal equilibrium in the face of changing internal and external conditions. It emphasizes the rapid internal and external effector system changes that occur to optimize organism readiness to cope with any new external stimulus situation. Truly life-threatening stimuli elicit instinctive behavior such as fight, flee, or hide. If the stimulus is not life-threatening, the organism rapidly learns to adjust to an appropriate level of overall responsiveness over stimulus repetitions. The rapid asymptotic level approached by those who decrease their overall responsiveness to the second stimulus (habituaters) and those who increase their overall responsiveness to an identical second stimulus (sensitizers) not only optimizes readiness to cope with any new stimulus situation but also reduces unnecessary energy expenditure. This paper is based on a retrospective analysis of data from 4 effector system responses to eight repetitive tone stimuli in adult human males. The effector systems include the galvanic skin response, finger pulse volume, muscle frontalis and heart rate. The new information provides the basis for further exploration of the BHT including new predictions and proposed relatively simple experiments to test them. PMID:22896782

A rapid colorimetric assay for mold spore germination using XTT tetrazolium salt

Treesearch

Carol A. Clausen; Vina W. Yang

2011-01-01

Current laboratory test methods to measure efficacy of new mold inhibitors are time consuming, some require specialized test equipment and ratings are subjective. Rapid, simple quantitative assays to measure the efficacy of mold inhibitors are needed. A quantitative, colorimetric microassay was developed using XTT tetrazolium salt to metabolically assess mold spore...

A Laboratory Experiment for Rapid Determination of the Stability of Vitamin C

ERIC Educational Resources Information Center

Adem, Seid M.; Lueng, Sam H.; Elles, Lisa M. Sharpe; Shaver, Lee Alan

2016-01-01

Experiments in laboratory manuals intended for general, organic, and biological (GOB) chemistry laboratories include few opportunities for students to engage in instrumental methods of analysis. Many of these students seek careers in modern health-related fields where experience in spectroscopic techniques would be beneficial. A simple, rapid,…

Compression-based distance (CBD): a simple, rapid, and accurate method for microbiota composition comparison

PubMed Central

2013-01-01

Background Perturbations in intestinal microbiota composition have been associated with a variety of gastrointestinal tract-related diseases. The alleviation of symptoms has been achieved using treatments that alter the gastrointestinal tract microbiota toward that of healthy individuals. Identifying differences in microbiota composition through the use of 16S rRNA gene hypervariable tag sequencing has profound health implications. Current computational methods for comparing microbial communities are usually based on multiple alignments and phylogenetic inference, making them time consuming and requiring exceptional expertise and computational resources. As sequencing data rapidly grows in size, simpler analysis methods are needed to meet the growing computational burdens of microbiota comparisons. Thus, we have developed a simple, rapid, and accurate method, independent of multiple alignments and phylogenetic inference, to support microbiota comparisons. Results We create a metric, called compression-based distance (CBD) for quantifying the degree of similarity between microbial communities. CBD uses the repetitive nature of hypervariable tag datasets and well-established compression algorithms to approximate the total information shared between two datasets. Three published microbiota datasets were used as test cases for CBD as an applicable tool. Our study revealed that CBD recaptured 100% of the statistically significant conclusions reported in the previous studies, while achieving a decrease in computational time required when compared to similar tools without expert user intervention. Conclusion CBD provides a simple, rapid, and accurate method for assessing distances between gastrointestinal tract microbiota 16S hypervariable tag datasets. PMID:23617892

Compression-based distance (CBD): a simple, rapid, and accurate method for microbiota composition comparison.

PubMed

Yang, Fang; Chia, Nicholas; White, Bryan A; Schook, Lawrence B

2013-04-23

Perturbations in intestinal microbiota composition have been associated with a variety of gastrointestinal tract-related diseases. The alleviation of symptoms has been achieved using treatments that alter the gastrointestinal tract microbiota toward that of healthy individuals. Identifying differences in microbiota composition through the use of 16S rRNA gene hypervariable tag sequencing has profound health implications. Current computational methods for comparing microbial communities are usually based on multiple alignments and phylogenetic inference, making them time consuming and requiring exceptional expertise and computational resources. As sequencing data rapidly grows in size, simpler analysis methods are needed to meet the growing computational burdens of microbiota comparisons. Thus, we have developed a simple, rapid, and accurate method, independent of multiple alignments and phylogenetic inference, to support microbiota comparisons. We create a metric, called compression-based distance (CBD) for quantifying the degree of similarity between microbial communities. CBD uses the repetitive nature of hypervariable tag datasets and well-established compression algorithms to approximate the total information shared between two datasets. Three published microbiota datasets were used as test cases for CBD as an applicable tool. Our study revealed that CBD recaptured 100% of the statistically significant conclusions reported in the previous studies, while achieving a decrease in computational time required when compared to similar tools without expert user intervention. CBD provides a simple, rapid, and accurate method for assessing distances between gastrointestinal tract microbiota 16S hypervariable tag datasets.

Aligned silver nanowire-based transparent electrodes for engineering polarisation-selective optoelectronics.

PubMed

Park, Byoungchoo; Bae, In-Gon; Huh, Yoon Ho

2016-01-18

We herein report on a remarkably simple, fast, and economic way of fabricating homogeneous and well oriented silver nanowires (AgNWs) that exhibit strong in-plane electrical and optical anisotropies. Using a small quantity of AgNW suspension, the horizontal-dip (H-dip) coating method was applied, in which highly oriented AgNWs were deposited unidirectionally along the direction of coating over centimetre-scale lengths very rapidly. In applying the H-dip-coating method, we adjusted the shear strain rate of the capillary flow in the Landau-Levich meniscus of the AgNW suspension, which induced a high degree of uniaxial orientational ordering (0.37-0.43) of the AgNWs, comparable with the ordering seen in archetypal nematic liquid crystal (LC) materials. These AgNWs could be used to fabricate not only transparent electrodes, but also LC-alignment electrodes for LC devices and/or polarising electrodes for organic photovoltaic devices, having the potential to revolutionise the architectures of a number of polarisation-selective opto-electronic devices for use in printed/organic electronics.

Fast-Response Turn-on Fluorescent Probes Based on Thiolysis of NBD Amine for H2 S Bioimaging.

PubMed

Wang, Runyu; Li, Zhifei; Zhang, Changyu; Li, Yanyan; Xu, Guoce; Zhang, Qiang-Zhe; Li, Lu-Yuan; Yi, Long; Xi, Zhen

2016-05-17

Hydrogen sulfide (H2 S) is an important endogenous signaling molecule with multiple biological functions. New selective fluorescent turn-on probes based on fast thiolyling of NBD (7-nitro-1,2,3-benzoxadiazole) amine were explored for sensing H2 S in aqueous buffer and in living cells. The syntheses of both probes are simple and quite straightforward. The probes are highly sensitive and selective toward H2 S over other biologically relevant species. The fluorescein-NBD-based probe showed 65-fold green fluorescent increase upon H2 S activation. The rhodamine-NBD-based probe reacted rapidly with H2 S (t1/2 ≈1 min) to give a 4.5-fold increase in red fluorescence. Moreover, both probes were successfully used for monitoring H2 S in living cells and in mice. Based on such probe-based tools, we could observe H2 O2 -induced H2 S biogenesis in a concentration-dependent and time-dependent fashion in living cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Voltammetric determination of homocysteine using multiwall carbon nanotube paste electrode in the presence of chlorpromazine as a mediator.

PubMed

Gholami-Orimi, Fathali; Taleshi, Farshad; Biparva, Pourya; Karimi-Maleh, Hassan; Beitollahi, Hadi; Ebrahimi, Hamid R; Shamshiri, Mohamad; Bagheri, Hasan; Fouladgar, Masoud; Taherkhani, Ali

2012-01-01

We propose chlorpromazine (CHP) as a new mediator for the rapid, sensitive, and highly selective voltammetric determination of homocysteine (Hcy) using multiwall carbon nanotube paste electrode (MWCNTPE). The experimental results showed that the carbon nanotube paste electrode has a highly electrocatalytic activity for the oxidation of Hcy in the presence of CHP as a mediator. Cyclic voltammetry, double potential step chronoamperometry, and square wave voltammetry (SWV) are used to investigate the suitability of CHP at the surface of MWCNTPE as a mediator for the electrocatalytic oxidation of Hcy in aqueous solutions. The kinetic parameters of the system, including electron transfer coefficient, and catalytic rate constant were also determined using the electrochemical approaches. In addition, SWV was used for quantitative analysis. SWV showed wide linear dynamic range (0.1-210.0 μM Hcy) with a detection limit of 0.08 μM Hcy. Finally, this method was also examined as a selective, simple, and precise electrochemical sensor for the determination of Hcy in real samples.

Voltammetric Determination of Homocysteine Using Multiwall Carbon Nanotube Paste Electrode in the Presence of Chlorpromazine as a Mediator

PubMed Central

Gholami-Orimi, Fathali; Taleshi, Farshad; Biparva, Pourya; Karimi-Maleh, Hassan; Beitollahi, Hadi; Ebrahimi, Hamid R.; Shamshiri, Mohamad; Bagheri, Hasan; Fouladgar, Masoud; Taherkhani, Ali

2012-01-01

We propose chlorpromazine (CHP) as a new mediator for the rapid, sensitive, and highly selective voltammetric determination of homocysteine (Hcy) using multiwall carbon nanotube paste electrode (MWCNTPE). The experimental results showed that the carbon nanotube paste electrode has a highly electrocatalytic activity for the oxidation of Hcy in the presence of CHP as a mediator. Cyclic voltammetry, double potential step chronoamperometry, and square wave voltammetry (SWV) are used to investigate the suitability of CHP at the surface of MWCNTPE as a mediator for the electrocatalytic oxidation of Hcy in aqueous solutions. The kinetic parameters of the system, including electron transfer coefficient, and catalytic rate constant were also determined using the electrochemical approaches. In addition, SWV was used for quantitative analysis. SWV showed wide linear dynamic range (0.1–210.0 μM Hcy) with a detection limit of 0.08 μM Hcy. Finally, this method was also examined as a selective, simple, and precise electrochemical sensor for the determination of Hcy in real samples. PMID:22675657

Diagnostics Strategies with Electrochemical Affinity Biosensors Using Carbon Nanomaterials as Electrode Modifiers

PubMed Central

Campuzano, Susana; Yáñez-Sedeño, Paloma; Pingarrón, José M.

2016-01-01

Early diagnosis is often the key to successful patient treatment and survival. The identification of various disease signaling biomarkers which reliably reflect normal and disease states in humans in biological fluids explain the burgeoning research field in developing new methodologies able to determine the target biomarkers in complex biological samples with the required sensitivity and selectivity and in a simple and rapid way. The unique advantages offered by electrochemical sensors together with the availability of high affinity and specific bioreceptors and their great capabilities in terms of sensitivity and stability imparted by nanostructuring the electrode surface with different carbon nanomaterials have led to the development of new electrochemical biosensing strategies that have flourished as interesting alternatives to conventional methodologies for clinical diagnostics. This paper briefly reviews the advantages of using carbon nanostructures and their hybrid nanocomposites as electrode modifiers to construct efficient electrochemical sensing platforms for diagnosis. The review provides an updated overview of some selected examples involving attractive amplification and biosensing approaches which have been applied to the determination of relevant genetic and protein diagnostics biomarkers. PMID:28035946

RIS integrated IMAC system

NASA Astrophysics Data System (ADS)

Angelhed, Jan-Erik; Carlsson, Goeran; Gustavsson, Staffan; Karlsson, Anders; Larsson, Lars E. G.; Svensson, Sune; Tylen, Ulf

1998-07-01

An Image Management And Communication (IMAC) system adapted to the X-ray department at Sahlgrenska University Hospital has been developed using standard components. Two user demands have been considered primary: Rapid access to (display of) images and an efficient worklist management. To fulfil these demands a connection between the IMAC system and the existing Radiological Information System (RIS) has been implemented. The functional modules are: check of information consistency in data exported from image sources, a (logically) central storage of image data, viewing facility for high speed-, large volume-, clinical work, and an efficient interface to the RIS. Also, an image related database extension has been made to the RIS. The IMAC system has a strictly modular design with a simple structure. The image archive and short term storage are logically the same and acts as a huge disk. Through NFS all image data is available to all the connected workstations. All patient selection for viewing is through worklists, which are created by selection criteria in the RIS, by the use of barcodes, or, in singular cases, by entering the patient ID by hand.

One-pot carbonization synthesis of europium-doped carbon quantum dots for highly selective detection of tetracycline

NASA Astrophysics Data System (ADS)

Li Liu, Meng; Chen, Bin Bin; Yang, Tong; Wang, Jian; Liu, Xi Dong; Zhi Huang, Cheng

2017-03-01

The detection of tetracycline is of great significance because of its damaging effects on human health, such as renal toxicity and hemolytic anemia. Any release of tetracycline into the surrounding environment can produce bacterial drug resistance. We develop a new sensitive and selective detection approach for tetracycline in complex water samples by preparing europium-doped carbon quantum dots (Eu-CQDs) through a simple and rapid carbonization method operating at 200 °C for 5 min. The Eu-CQDs are characterized by blue photoluminescence, excitation-wavelength-dependent emission and excellent stability. Importantly, the fluorescence of the Eu-CQDs can be quenched efficiently by tetracycline, based on the strong inner filter effect mechanism between Eu-CQDs and tetracycline, making the fluorescence intensity ratio (I 0/I) of the Eu-CQDs at 465 nm correlate linearly with the concentration of tetracycline in the range of 0.5-200 μM, with a limit of detection of 0.3 μM. This shows the broad applicability of the Eu-CQDs in pursuing the concepts of simplicity and specificity for analytical purposes.

A Highly Sensitive and Selective Method for the Determination of an Iodate in Table-salt Samples Using Malachite Green-based Spectrophotometry.

PubMed

Konkayan, Mongkol; Limchoowong, Nunticha; Sricharoen, Phitchan; Chanthai, Saksit

2016-01-01

A simple, rapid, and sensitive malachite green-based spectrophotometric method for the selective trace determination of an iodate has been developed and presented for the first time. The reaction mixture was specifically involved in the liberation of iodine in the presence of an excess of iodide in an acidic condition following an instantaneous reaction between the liberated iodine and malachite green dye. The optimum condition was obtained with a buffer solution pH of 5.2 in the presence of 40 mg L -1 potassium iodide and 1.5 × 10 -5 M malachite green for a 5-min incubation time. The iodate contents in some table-salt samples were in the range of 26 to 45 mg kg -1 , while those of drinking water, tap water, canal water, and seawater samples were not detectable (< 96 ng mL -1 of limits of detection, LOQ) with their satisfied method of recoveries of between 93 and 108%. The results agreed with those obtained using ICP-OES for comparison.

Determination of trans Fat in Selected Fast Food Products and Hydrogenated Fats of India Using Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) Spectroscopy.

PubMed

Khan, Mohd Umar; Hassan, Mohammad Fahimul; Rauf, Abdul

2017-01-01

This paper reports the application of a simple and rapid method for the determination of trans fatty acid (TFA) content in some of the selected Indian fast food products and hydrogenated fats using Fourier transform infrared (FTIR) spectroscopy in conjunction with second derivative procedure. FTIR spectroscopy has been successfully applied to trans measurement using the absorbance bands at or near 966 cm -1 in the FTIR spectra. It was found from the analysis that TFA content of fast food product was ranging from 1.57% to 3.83% of the total fat while for hydrogenated fats, comparatively large quantity of TFA was detected in the range of 3.31% to 4.73%. Since GC-FID is most widely used method for the determination of fatty acid (FA) composition, this method was used for the sake of comparison. Value of regression coefficient was found very close to one (0.99503) with standard deviation of 0.10247 showing a good agreement between GC-FID and proposed ATR-FTIR method.

S-genotype identification based on allele-specific PCR in Japanese pear

PubMed Central

Nashima, Kenji; Terakami, Shingo; Nishio, Sogo; Kunihisa, Miyuki; Nishitani, Chikako; Saito, Toshihiro; Yamamoto, Toshiya

2015-01-01

Gametophytic self-incompatibility in Japanese pear (Pyrus pyrifolia Nakai) is controlled by the single, multi-allelic S-locus. Information about the S-genotypes is important for breeding and the selection of pollen donors for fruit production. Rapid and reliable S-genotype identification system is necessary for efficient breeding of new cultivars in Japanese pear. We designed S allele-specific PCR primer pairs for ten previously reported S-RNase alleles (S1–S9 and Sk) as simple and reliable method. Specific nucleotide sequences were chosen to design the primers to amplify fragments of only the corresponding S alleles. The developed primer pairs were evaluated by using homozygous S-genotypes (S1/S1–S9/S9 and S4sm/S4sm) and 14 major Japanese pear cultivars, and found that S allele-specific primer pairs can identify S-genotypes effectively. The S allele-specific primer pairs developed in this study will be useful for efficient S-genotyping and for marker-assisted selection in Japanese pear breeding programs. PMID:26175617

Ratio manipulating spectrophotometry versus chemometry as stability indicating methods for cefquinome sulfate determination

NASA Astrophysics Data System (ADS)

Yehia, Ali M.; Arafa, Reham M.; Abbas, Samah S.; Amer, Sawsan M.

2016-01-01

Spectral resolution of cefquinome sulfate (CFQ) in the presence of its degradation products was studied. Three selective, accurate and rapid spectrophotometric methods were performed for the determination of CFQ in the presence of either its hydrolytic, oxidative or photo-degradation products. The proposed ratio difference, derivative ratio and mean centering are ratio manipulating spectrophotometric methods that were satisfactorily applied for selective determination of CFQ within linear range of 5.0-40.0 μg mL- 1. Concentration Residuals Augmented Classical Least Squares was applied and evaluated for the determination of the cited drug in the presence of its all degradation products. Traditional Partial Least Squares regression was also applied and benchmarked against the proposed advanced multivariate calibration. Experimentally designed 25 synthetic mixtures of three factors at five levels were used to calibrate and validate the multivariate models. Advanced chemometrics succeeded in quantitative and qualitative analyses of CFQ along with its hydrolytic, oxidative and photo-degradation products. The proposed methods were applied successfully for different pharmaceutical formulations analyses. These developed methods were simple and cost-effective compared with the manufacturer's RP-HPLC method.

In-situ sequential laser transfer and laser reduction of graphene oxide films

NASA Astrophysics Data System (ADS)

Papazoglou, S.; Petridis, C.; Kymakis, E.; Kennou, S.; Raptis, Y. S.; Chatzandroulis, S.; Zergioti, I.

2018-04-01

Achieving high quality transfer of graphene on selected substrates is a priority in device fabrication, especially where drop-on-demand applications are involved. In this work, we report an in-situ, fast, simple, and one step process that resulted in the reduction, transfer, and fabrication of reduced graphene oxide-based humidity sensors, using picosecond laser pulses. By tuning the laser illumination parameters, we managed to implement the sequential printing and reduction of graphene oxide flakes. The overall process lasted only a few seconds compared to a few hours that our group has previously published. DC current measurements, X-Ray Photoelectron Spectroscopy, X-Ray Diffraction, and Raman Spectroscopy were employed in order to assess the efficiency of our approach. To demonstrate the applicability and the potential of the technique, laser printed reduced graphene oxide humidity sensors with a limit of detection of 1700 ppm are presented. The results demonstrated in this work provide a selective, rapid, and low-cost approach for sequential transfer and photochemical reduction of graphene oxide micro-patterns onto various substrates for flexible electronics and sensor applications.

Fabric phase sorptive extraction of selected penicillin antibiotic residues from intact milk followed by high performance liquid chromatography with diode array detection.

PubMed

Samanidou, Victoria; Michaelidou, Katia; Kabir, Abuzar; Furton, Kenneth G

2017-06-01

Fabric phase sorptive extraction (FPSE), a novel sorbent-based microextraction method, was evaluated as a simple and rapid strategy for the extraction of four penicillin antibiotic residues (benzylpenicillin, cloxacillin, dicloxacillin and oxacillin) from cows' milk, without prior protein precipitation. Time-consuming solvent evaporation and reconstitution steps were eliminated successfully from the sample preparation workflow. FPSE utilizes a flexible fabric substrate, chemically coated with sol-gel derived, highly efficient, organic-inorganic hybrid sorbent as the extraction medium. Herein short-chain poly(ethylene glycol) provided optimum extraction sensitivity for the selected penicillins, which were analysed using an RP-HPLC method, validated according to the European Decision 657/2002/EC. The limit of quantitation was 10μg/kg for benzylpenicillin, 20μg/kg for cloxacillin, 25μg/kg dicloxacillin and 30μg/kg oxacillin. These are a similar order of magnitude with those reported in the literature and (with the exception of benzylpenicillin) are less than the maximum residue limits (MRL) set by European legislation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Genetic Polymorphism in Wine Yeasts: Mechanisms and Methods for Its Detection

PubMed Central

Guillamón, José M.; Barrio, Eladio

2017-01-01

The processes of yeast selection for using as wine fermentation starters have revealed a great phenotypic diversity both at interspecific and intraspecific level, which is explained by a corresponding genetic variation among different yeast isolates. Thus, the mechanisms involved in promoting these genetic changes are the main engine generating yeast biodiversity. Currently, an important task to understand biodiversity, population structure and evolutionary history of wine yeasts is the study of the molecular mechanisms involved in yeast adaptation to wine fermentation, and on remodeling the genomic features of wine yeast, unconsciously selected since the advent of winemaking. Moreover, the availability of rapid and simple molecular techniques that show genetic polymorphisms at species and strain levels have enabled the study of yeast diversity during wine fermentation. This review will summarize the mechanisms involved in generating genetic polymorphisms in yeasts, the molecular methods used to unveil genetic variation, and the utility of these polymorphisms to differentiate strains, populations, and species in order to infer the evolutionary history and the adaptive evolution of wine yeasts, and to identify their influence on their biotechnological and sensorial properties. PMID:28522998

A Computational Study of How Orientation Bias in the Lateral Geniculate Nucleus Can Give Rise to Orientation Selectivity in Primary Visual Cortex

PubMed Central

Kuhlmann, Levin; Vidyasagar, Trichur R.

2011-01-01

Controversy remains about how orientation selectivity emerges in simple cells of the mammalian primary visual cortex. In this paper, we present a computational model of how the orientation-biased responses of cells in lateral geniculate nucleus (LGN) can contribute to the orientation selectivity in simple cells in cats. We propose that simple cells are excited by lateral geniculate fields with an orientation-bias and disynaptically inhibited by unoriented lateral geniculate fields (or biased fields pooled across orientations), both at approximately the same retinotopic co-ordinates. This interaction, combined with recurrent cortical excitation and inhibition, helps to create the sharp orientation tuning seen in simple cell responses. Along with describing orientation selectivity, the model also accounts for the spatial frequency and length–response functions in simple cells, in normal conditions as well as under the influence of the GABAA antagonist, bicuculline. In addition, the model captures the response properties of LGN and simple cells to simultaneous visual stimulation and electrical stimulation of the LGN. We show that the sharp selectivity for stimulus orientation seen in primary visual cortical cells can be achieved without the excitatory convergence of the LGN input cells with receptive fields along a line in visual space, which has been a core assumption in classical models of visual cortex. We have also simulated how the full range of orientations seen in the cortex can emerge from the activity among broadly tuned channels tuned to a limited number of optimum orientations, just as in the classical case of coding for color in trichromatic primates. PMID:22013414

Examining the Simple View of Reading in a Transparent Orthography: A Longitudinal Study from Kindergarten to Grade 3

ERIC Educational Resources Information Center

Torppa, Minna; Georgiou, George K.; Lerkkanen, Marja-Kristiina; Niemi, Pekka; Poikkeus, Anna-Maija

2016-01-01

This study examined the dynamic relationships among the components of the Simple View of Reading (SVR) in a transparent orthography (Finnish) and the predictive value of cognitive skills (phonological awareness, letter knowledge, rapid naming, and vocabulary) on the SVR components. Altogether, 1,815 Finnish children were followed from kindergarten…

Starting to Experiment with Wave Power

ERIC Educational Resources Information Center

Hare, Jonathan; McCallie, Ellen

2005-01-01

Outlined is a simple design for a working wave-powered electrical generator based on one made on the BBC "Rough Science" TV series. The design has been kept deliberately simple to facilitate rapid pupil/student involvement and most importantly so that there is much scope for their own ingenuity and ideas. The generator works on the principle of…

Construction and applications of exon-trapping gene-targeting vectors with a novel strategy for negative selection.

PubMed

Saito, Shinta; Ura, Kiyoe; Kodama, Miho; Adachi, Noritaka

2015-06-30

Targeted gene modification by homologous recombination provides a powerful tool for studying gene function in cells and animals. In higher eukaryotes, non-homologous integration of targeting vectors occurs several orders of magnitude more frequently than does targeted integration, making the gene-targeting technology highly inefficient. For this reason, negative-selection strategies have been employed to reduce the number of drug-resistant clones associated with non-homologous vector integration, particularly when artificial nucleases to introduce a DNA break at the target site are unavailable or undesirable. As such, an exon-trap strategy using a promoterless drug-resistance marker gene provides an effective way to counterselect non-homologous integrants. However, constructing exon-trapping targeting vectors has been a time-consuming and complicated process. By virtue of highly efficient att-mediated recombination, we successfully developed a simple and rapid method to construct plasmid-based vectors that allow for exon-trapping gene targeting. These exon-trap vectors were useful in obtaining correctly targeted clones in mouse embryonic stem cells and human HT1080 cells. Most importantly, with the use of a conditionally cytotoxic gene, we further developed a novel strategy for negative selection, thereby enhancing the efficiency of counterselection for non-homologous integration of exon-trap vectors. Our methods will greatly facilitate exon-trapping gene-targeting technologies in mammalian cells, particularly when combined with the novel negative selection strategy.

Systematic Development and Validation of a Thin-Layer Densitometric Bioanalytical Method for Estimation of Mangiferin Employing Analytical Quality by Design (AQbD) Approach

PubMed Central

Khurana, Rajneet Kaur; Rao, Satish; Beg, Sarwar; Katare, O.P.; Singh, Bhupinder

2016-01-01

The present work aims at the systematic development of a simple, rapid and highly sensitive densitometry-based thin-layer chromatographic method for the quantification of mangiferin in bioanalytical samples. Initially, the quality target method profile was defined and critical analytical attributes (CAAs) earmarked, namely, retardation factor (Rf), peak height, capacity factor, theoretical plates and separation number. Face-centered cubic design was selected for optimization of volume loaded and plate dimensions as the critical method parameters selected from screening studies employing D-optimal and Plackett–Burman design studies, followed by evaluating their effect on the CAAs. The mobile phase containing a mixture of ethyl acetate : acetic acid : formic acid : water in a 7 : 1 : 1 : 1 (v/v/v/v) ratio was finally selected as the optimized solvent for apt chromatographic separation of mangiferin at 262 nm with Rf 0.68 ± 0.02 and all other parameters within the acceptance limits. Method validation studies revealed high linearity in the concentration range of 50–800 ng/band for mangiferin. The developed method showed high accuracy, precision, ruggedness, robustness, specificity, sensitivity, selectivity and recovery. In a nutshell, the bioanalytical method for analysis of mangiferin in plasma revealed the presence of well-resolved peaks and high recovery of mangiferin. PMID:26912808

Determination of Selected Amino Acids in Serum of Patients with Liver Disease.

PubMed

Kanďár, Roman; Drábková, Petra; Toiflová, Tereza; Čegan, Alexander

2016-01-01

The determination of amino acids can be a reliable approach for extended diagnosis of liver diseases. This is because liver disease can be a cause of impaired amino acid metabolism. Therefore, a method for the determination of serum amino acids, applicable for clinical purposes, is necessary. The aim of this study was to find differences in the levels of selected amino acids between patients with liver disease and a control group. Samples of peripheral venous blood were obtained from a group of patients with liver disease (n = 131, 59 women at an average age of 60 years and 72 men at an average age of 52 years) and a control group (n = 105, 47 women at an average age of 62 years and 58 men at an average age of 58 years). Before the separation, the amino acids were derivatized with naphthalene-2,3-dicarboxaldehyde. For the separation, reverse phase column was used. The effluent was monitored with a fluorescence detector. There were significant differences in the concentrations of some amino acids between the patients and the control group, but also between women and men. Correlations between some amino acids and markers of liver blood tests and lipid metabolism were observed. A simple, relatively rapid and selective HPLC method with fluorescence detection for the determination of selected amino acids in serum has been developed.

Rapid and Simple Phenotypic Assay for Drug Susceptibility of Human Immunodeficiency Virus Type 1 Using CCR5-Expressing HeLa/CD4+ Cell Clone 1-10 (MAGIC-5)

PubMed Central

Hachiya, Atsuko; Aizawa-Matsuoka, Saori; Tanaka, Mari; Takahashi, Yukiko; Ida, Setsuko; Gatanaga, Hiroyuki; Hirabayashi, Yoshihiro; Kojima, Asato; Tatsumi, Masashi; Oka, Shinichi

2001-01-01

We describe a rapid and simple novel phenotypic assay for drug susceptibility of human immunodeficiency virus type-1 (HIV-1) using a CCR5-expressing HeLa/CD4+ cell clone 1-10 (MAGIC-5). MAGIC-5 cells produced large amounts of HIV-1 in culture supernatants, which enabled us to perform the phenotypic resistance assay. Determination of HIV-1 susceptibility to various protease inhibitors (PI) and nucleoside reverse transcriptase inhibitors was completed within 15 days in T-cell-tropic (X4) and macrophage-tropic (R5) viruses using fresh plasma samples containing at least 104 copies/ml. The nucleotide sequence of the envelope V3 region of HIV-1 in plasma was almost identical to that of the virus isolated by MAGIC-5 cells, suggesting a lack of selection bias in our assay. The assay variability was confined to within five-fold in all drugs examined. Accordingly, we used a 10-fold increase in the 50% inhibitory concentration as the cutoff value for viral resistance in the present assay. HIV-1 resistant to lamivudine, which was not detected by conventional genotypic assays, was isolated. In HIV-1 with PI-associated primary amino acid substitutions, our assay showed that drug resistance profiles correlated well with previously reported genotypic-assay data. Furthermore, our assay provided comprehensive results regarding PI resistance in the presence of multiple mutations. The novel assay successfully quantified the level of resistance of clinical HIV-1 isolates to a battery of anti-HIV drugs, indicating its clinical usefulness, particularly in patients who failed to respond to antiretroviral chemotherapy. PMID:11158746

Indium tin oxide-coated glass modified with reduced graphene oxide sheets and gold nanoparticles as disposable working electrodes for dopamine sensing in meat samples

NASA Astrophysics Data System (ADS)

Yang, Jiang; Strickler, J. Rudi; Gunasekaran, Sundaram

2012-07-01

Sensitive, rapid, and accurate detection of dopamine (DA) at low cost is needed for clinical diagnostic and therapeutic purposes as well as to prevent illegal use of DA in animal feed. We employed a simple approach to synthesize reduced graphene oxide sheets (rGOS) and gold nanoparticles (AuNPs) at room temperature on indium tin oxide-coated glass (ITO) slides as disposable working electrodes for sensing DA. Graphene oxide (GO) was directly reduced on ITO to remove oxygenated species via a rapid and green process without using chemical reducing reagents. AuNPs were electrochemically deposited in situ on rGOS-ITO with fairly uniform density and size. The sensitivity of the AuNPs-rGOS-ITO sensor for DA detection is 62.7 μA mM-1 cm-2 with good selectivity against common electrochemically interfering species such as ascorbic acid (AA) and uric acid (UA), and the detection limit measured by differential pulse voltammetry (DPV), at a signal-noise ratio of 3, was 6.0 × 10-8 M. The electrochemical catalysis of DA was proven to be a surface process with an electron transfer coefficient (α) of 0.478 and a rate constant (ks) of 1.456 s-1. It correlates well with the conventional UV-vis spectrophotometric approach (R = 0.9973) but with more than thrice the dynamic range (up to 4.5 mM). The sensor also exhibited good stability and capability to detect DA in beef samples, and thus is a promising candidate for simple and inexpensive sub-nanomolar detection of DA, especially in the presence of UV-absorbing compounds.

Designing HIV Testing Algorithms Based on 2015 WHO Guidelines Using Data from Six Sites in Sub-Saharan Africa

PubMed Central

Kosack, Cara S.; Shanks, Leslie; Beelaert, Greet; Benson, Tumwesigye; Savane, Aboubacar; Ng'ang'a, Anne; Bita, André; Zahinda, Jean-Paul B. N.; Fransen, Katrien

2017-01-01

ABSTRACT Our objective was to evaluate the performance of HIV testing algorithms based on WHO recommendations, using data from specimens collected at six HIV testing and counseling sites in sub-Saharan Africa (Conakry, Guinea; Kitgum and Arua, Uganda; Homa Bay, Kenya; Douala, Cameroon; Baraka, Democratic Republic of Congo). A total of 2,780 samples, including 1,306 HIV-positive samples, were included in the analysis. HIV testing algorithms were designed using Determine as a first test. Second and third rapid diagnostic tests (RDTs) were selected based on site-specific performance, adhering where possible to the WHO-recommended minimum requirements of ≥99% sensitivity and specificity. The threshold for specificity was reduced to 98% or 96% if necessary. We also simulated algorithms consisting of one RDT followed by a simple confirmatory assay. The positive predictive values (PPV) of the simulated algorithms ranged from 75.8% to 100% using strategies recommended for high-prevalence settings, 98.7% to 100% using strategies recommended for low-prevalence settings, and 98.1% to 100% using a rapid test followed by a simple confirmatory assay. Although we were able to design algorithms that met the recommended PPV of ≥99% in five of six sites using the applicable high-prevalence strategy, options were often very limited due to suboptimal performance of individual RDTs and to shared falsely reactive results. These results underscore the impact of the sequence of HIV tests and of shared false-reactivity data on algorithm performance. Where it is not possible to identify tests that meet WHO-recommended specifications, the low-prevalence strategy may be more suitable. PMID:28747371

Comparative Validation of Five Quantitative Rapid Test Kits for the Analysis of Salt Iodine Content: Laboratory Performance, User- and Field-Friendliness

PubMed Central

Rohner, Fabian; Kangambèga, Marcelline O.; Khan, Noor; Kargougou, Robert; Garnier, Denis; Sanou, Ibrahima; Ouaro, Bertine D.; Petry, Nicolai; Wirth, James P.; Jooste, Pieter

2015-01-01

Background Iodine deficiency has important health and development consequences and the introduction of iodized salt as national programs has been a great public health success in the past decades. To render national salt iodization programs sustainable and ensure adequate iodization levels, simple methods to quantitatively assess whether salt is adequately iodized are required. Several methods claim to be simple and reliable, and are available on the market or are in development. Objective This work has validated the currently available quantitative rapid test kits (quantRTK) in a comparative manner for both their laboratory performance and ease of use in field settings. Methods Laboratory performance parameters (linearity, detection and quantification limit, intra- and inter-assay imprecision) were conducted on 5 quantRTK. We assessed inter-operator imprecision using salt of different quality along with the comparison of 59 salt samples from across the globe; measurements were made both in a laboratory and a field setting by technicians and non-technicians. Results from the quantRTK were compared against iodometric titration for validity. An ‘ease-of-use’ rating system was developed to identify the most suitable quantRTK for a given task. Results Most of the devices showed acceptable laboratory performance, but for some of the devices, use by non-technicians revealed poorer performance when working in a routine manner. Of the quantRTK tested, the iCheck® and I-Reader® showed most consistent performance and ease of use, and a newly developed paper-based method (saltPAD) holds promise if further developed. Conclusions User- and field-friendly devices are now available and the most appropriate quantRTK can be selected depending on the number of samples and the budget available. PMID:26401655

Rapid identification and quantification of tumor cells using an electrocatalytic method based on gold nanoparticles.

PubMed

de la Escosura-Muñiz, Alfredo; Sánchez-Espinel, Christian; Díaz-Freitas, Belén; González-Fernández, Africa; Maltez-da Costa, Marisa; Merkoçi, Arben

2009-12-15

There is a high demand for simple, rapid, efficient, and user-friendly alternative methods for the detection of cells in general and, in particular, for the detection of cancer cells. A biosensor able to detect cells would be an all-in-one dream device for such applications. The successful integration of nanoparticles into cell detection assays could allow for the development of this novel class of cell sensors. Indeed, their application could well have a great future in diagnostics, as well as other fields. As an example of a novel biosensor, we report here an electrocatalytic device for the specific identification of tumor cells that quantifies gold nanoparticles (AuNPs) coupled with an electrotransducing platform/sensor. Proliferation and adherence of tumor cells are achieved on the electrotransducer/detector, which consists of a mass-produced screen-printed carbon electrode (SPCE). In situ identification/quantification of tumor cells is achieved with a detection limit of 4000 cells per 700 microL of suspension. This novel and selective cell-sensing device is based on the reaction of cell surface proteins with specific antibodies conjugated with AuNPs. Final detection requires only a couple of minutes, taking advantage of the catalytic properties of AuNPs on hydrogen evolution. The proposed detection method does not require the chemical agents used in most existing assays for the detection of AuNPs. It allows for the miniaturization of the system and is much cheaper than other expensive and sophisticated methods used for tumor cell detection. We envisage that this device could operate in a simple way as an immunosensor or DNA sensor. Moreover, it could be used, even by inexperienced staff, for the detection of protein molecules or DNA strands.

[Rapid determination of volatile flavor compounds in soy sauce using head space solid-phase microextraction and gas chromatography-mass spectrometry].

PubMed

Yan, Liujun; Zhang, Yanfang; Tao, Wenyi; Wang, Liping; Wu, Shengfang

2008-05-01

A rapid and simple method was developed for the determination of volatile flavor compounds (VFCs) in soy sauce by head space solid-phase microextraction (HS-SPME) coupled to capillary gas chromatography-mass spectrometry (GC-MS). Five types of SPME fibers, including 85 microm PA, 100 microm PDMS, 75 microm CAR/PDMS, 65 microm PDMS/DVB, 50 microm DVB/CAR/PDMS were investigated. Three parameters for HS-SPME in terms of adsorption time, salt concentration, and extraction temperature were optimized. Adsorption time tested in this study were 20, 40 and 60 minutes; the salt concentrations were 180, 210, 250, 270 and 300 g/L; and extraction temperatures were 25, 35, 45, 55 and 65 degrees C. The concentrations of the compounds were calculated based on their relative peak areas to the internal standard of 2-octanol. An 85 microm PA fiber, adsorption time of 40 min, a temperature of 45 degrees C and NaCl concentration of 250 g/L were selected as th optimum conditions. This optimized method was applied to evaluate a real sample. As a result, 97 compounds in a soy sauce sample were isolated and identified successfully. The results showed that alcohols, carboxylic acids, esters and phenols were the major VFCs of soy sauce. The most important groups of volatile compounds in the soy sauce sample were ethanol, hexadecanoic acid, phenylethyl alcohol and 2,3-butanediol. In addition, some oxo-compounds and heterocyclic compounds were also found. The average relative standard deviation of the relative peak area was 12.1%, and the recoveries were 79.9% - 109.6%. The method is simple, fast and accurate with high reproducibility, high sensitivity and low cost.

Development and validation of an HPLC method for the rapid and simultaneous determination of 6-mercaptopurine and four of its metabolites in plasma and red blood cells.

PubMed

Hawwa, Ahmed F; Millership, Jeff S; Collier, Paul S; McElnay, James C

2009-02-20

An HPLC method has been developed and validated for the rapid determination of mercaptopurine and four of its metabolites; thioguanine, thiouric acid, thioxanthine and methylmercaptopurine in plasma and red blood cells. The method involves a simple treatment procedure based on deproteinisation by perchloric acid followed by acid hydrolysis and heating for 45min at 100 degrees C. The developed method was linear over the concentration range studied with a correlation coefficient >0.994 for all compounds in both plasma and erythrocytes. The lower limits of quantification were 13, 14, 3, 2, 95pmol/8 x 10(8) RBCs and 2, 5, 2, 3, 20ng/ml plasma for thioguanine, thiouric acid, mercaptopurine, thioxanthine and methylmercaptopurine, respectively. The method described is selective and sensitive enough to analyse the different metabolites in a single run under isocratic conditions. Furthermore, it has been shown to be applicable for monitoring these metabolites in paediatric patients due to the low volume requirement (200microl of plasma or erythrocytes) and has been successfully applied for investigating population pharmacokinetics, pharmacogenetics and non-adherence to therapy in these patients.

WGE: a CRISPR database for genome engineering.

PubMed

Hodgkins, Alex; Farne, Anna; Perera, Sajith; Grego, Tiago; Parry-Smith, David J; Skarnes, William C; Iyer, Vivek

2015-09-15

The rapid development of CRISPR-Cas9 mediated genome editing techniques has given rise to a number of online and stand-alone tools to find and score CRISPR sites for whole genomes. Here we describe the Wellcome Trust Sanger Institute Genome Editing database (WGE), which uses novel methods to compute, visualize and select optimal CRISPR sites in a genome browser environment. The WGE database currently stores single and paired CRISPR sites and pre-calculated off-target information for CRISPRs located in the mouse and human exomes. Scoring and display of off-target sites is simple, and intuitive, and filters can be applied to identify high-quality CRISPR sites rapidly. WGE also provides a tool for the design and display of gene targeting vectors in the same genome browser, along with gene models, protein translation and variation tracks. WGE is open, extensible and can be set up to compute and present CRISPR sites for any genome. The WGE database is freely available at www.sanger.ac.uk/htgt/wge : vvi@sanger.ac.uk or skarnes@sanger.ac.uk Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press.

Concurrent infections of pseudorabies virus and porcine bocavirus in China detected by duplex nanoPCR.

PubMed

Luo, Yakun; Liang, Lin; Zhou, Ling; Zhao, Kai; Cui, Shangjin

2015-07-01

Nanoparticle-assisted polymerase chain reaction (nanoPCR) is a novel method for the simple, rapid, and specific amplification of DNA and has been used to detect viruses. A duplex nanoPCR molecular detection system was developed to detect pseudorabies virus (PRV) and porcine bocavirus (PBoV). Primers were selected to target conserved regions within the PRV gE gene and the PBoV NS1 gene. Under optimized nanoPCR reaction conditions, two specific fragments of 316 bp (PRV) and 996 bp (PBoV) were amplified by the duplex nanoPCR with a detection limit of 6 copies for PRV and 95 copies for PBoV; no fragments were amplified when other porcine viruses were used as template. When used to test 550 clinical samples, the duplex nanoPRC assay and a conventional duplex PCR assay provided very similar results (98.1% consistency); single PRV infections, single PBoV infections, and concurrent PRV and PBoV infections were detected in 37%, 15%, and 9% of the samples, respectively. The results indicate that the novel duplex nanoPCR assay is useful for the rapid detection of PRV and PBoV in pigs. Copyright © 2015 Elsevier B.V. All rights reserved.

Rapid large area fabrication of multiscale through-hole membranes.

PubMed

Tahk, Dongha; Paik, Sang-Min; Lim, Jungeun; Bang, Seokyoung; Oh, Soojung; Ryu, Hyunryul; Jeon, Noo Li

2017-05-16

There are many proposed mechanisms by which single cells can be trapped; among them is the through-hole membrane for the characterization of individual microorganisms. Due to the small scale of the fabricated pores, the construction of through-hole membranes on a large scale and with relatively large areas faces many difficulties. This paper describes novel fabrication methods for a large-area, freestanding micro/nano through-hole membrane constructed from versatile membrane materials using through-hole membranes on a microfluidic chip (THMMC). This process can rapidly (<20 min) fabricate membranes with high fidelity multiscale hole size without residual layers. The through-hole site was easily customizable from the micro to the nanoscale, with a low or high aspect ratio giving rise to reliable membranes. Also, the rigidity and biocompatibility of the through-hole membrane are easily tunable by simple injection of versatile membrane materials to obtain a large area (up to 3600 mm 2 ). Membranes produced in this manner were then applied as a proof of concept for the isolation, cultivation, and quantification of individual micro-algal cells for selection with respect to the growth rate, while controlling the quorum sensing mediated metabolic and proliferative changes.

Enzyme-Encapsulated Liposome-Linked Immunosorbent Assay Enabling Sensitive Personal Glucose Meter Readout for Portable Detection of Disease Biomarkers.

PubMed

Lin, Bingqian; Liu, Dan; Yan, Jinmao; Qiao, Zhi; Zhong, Yunxin; Yan, Jiawei; Zhu, Zhi; Ji, Tianhai; Yang, Chaoyong James

2016-03-23

There is considerable demand for sensitive, selective, and portable detection of disease-associated proteins, particularly in clinical practice and diagnostic applications. Portable devices are highly desired for detection of disease biomarkers in daily life due to the advantages of being simple, rapid, user-friendly, and low-cost. Herein we report an enzyme-encapsulated liposome-linked immunosorbent assay for sensitive detection of proteins using personal glucose meters (PGM) for portable quantitative readout. Liposomes encapsulating a large amount of amyloglucosidase or invertase are surface-coated with recognition elements such as aptamers or antibodies for target recognition. By translating molecular recognition signal into a large amount of glucose with the encapsulated enzyme, disease biomarkers such as thrombin or C-reactive protein (CRP) can be quantitatively detected by a PGM with a high detection limit of 1.8 or 0.30 nM, respectively. With the advantages of portability, ease of use, and low-cost, the method reported here has potential for portable and quantitative detection of various targets for different POC testing scenarios, such as rapid diagnosis in clinic offices, health monitoring at the bedside, and chemical/biochemical safety control in the field.

EZ spheres: a stable and expandable culture system for the generation of pre-rosette multipotent stem cells from human ESCs and iPSCs.

PubMed

Ebert, Allison D; Shelley, Brandon C; Hurley, Amanda M; Onorati, Marco; Castiglioni, Valentina; Patitucci, Teresa N; Svendsen, Soshana P; Mattis, Virginia B; McGivern, Jered V; Schwab, Andrew J; Sareen, Dhruv; Kim, Ho Won; Cattaneo, Elena; Svendsen, Clive N

2013-05-01

We have developed a simple method to generate and expand multipotent, self-renewing pre-rosette neural stem cells from both human embryonic stem cells (hESCs) and human induced pluripotent stem cells (iPSCs) without utilizing embryoid body formation, manual selection techniques, or complex combinations of small molecules. Human ESC and iPSC colonies were lifted and placed in a neural stem cell medium containing high concentrations of EGF and FGF-2. Cell aggregates (termed EZ spheres) could be expanded for long periods using a chopping method that maintained cell-cell contact. Early passage EZ spheres rapidly down-regulated OCT4 and up-regulated SOX2 and nestin expression. They retained the potential to form neural rosettes and consistently differentiated into a range of central and peripheral neural lineages. Thus, they represent a very early neural stem cell with greater differentiation flexibility than other previously described methods. As such, they will be useful for the rapidly expanding field of neurological development and disease modeling, high-content screening, and regenerative therapies based on pluripotent stem cell technology. Copyright © 2013 Elsevier B.V. All rights reserved.

Selectable light-sheet uniformity using tuned axial scanning

PubMed Central

Duocastella, Martí; Arnold, Craig B.; Puchalla, Jason

2016-01-01

Light-sheet fluorescence microscopy (LSFM) is an optical sectioning technique capable of rapid three-dimensional (3D) imaging of a wide range of specimens with reduced phototoxicity and superior background rejection. However, traditional light-sheet generation approaches based on elliptical or circular Gaussian beams suffer an inherent trade-off between light-sheet thickness and area over which this thickness is preserved. Recently, an increase in light-sheet uniformity was demonstrated using rapid biaxial Gaussian beam scanning along the lateral and beam propagation directions. Here we apply a similar scanning concept to an elliptical beam generated by a cylindrical lens. In this case, only z-scanning of the elliptical beam is required and hence experimental implementation of the setup can be simplified. We introduce a simple dimensionless uniformity statistic to better characterize scanned light-sheets and experimentally demonstrate custom tailored uniformities up to a factor of 5 higher than those of un-scanned elliptical beams. This technique offers a straightforward way to generate and characterize a custom illumination profile that provides enhanced utilization of the detector dynamic range and field of view, opening the door to faster and more efficient 2D and 3D imaging. PMID:28132409

Use of SCW4 gene primers in PCR methods for the identification of six medically important Aspergillus species.

PubMed

Arancia, Silvia; Sandini, Silvia; De Carolis, Elena; Vella, Antonietta; Sanguinetti, Maurizio; Norelli, Sandro; De Bernardis, Flavia

2016-10-01

Aspergillus species are the cause of invasive mold infections in immunocompromised patients: Aspergillus fumigatus, A. flavus and A. terreus account for most cases of invasive aspergillosis (IA). As certain species are associated with higher mortality and vary in their resistance to antifungal therapy, diagnosis requires increasingly rapid molecular methods that enable sensitive detection and species discrimination. We have developed PCR and Multiplex PCR assays for the detection of six medically important Aspergillus spp. species DNA in bronchoalveolar lavage (BAL) specimens from hematology and intensive care unit (ICU) patients at risk of IA, using different species and genus-specific PCR primers, selected within the SCW4 gene, encoding a cell wall glucanase of A. fumigatus, similar to mannoprotein Mp65 of Candida albicans. The genus-specific PCR primers were able to amplify only Aspergillus DNAs but not that belonging to other fungal genera tested. The species-specific PCR primers allowed differentiation of each Aspergillus species by the amplicon length produced. The methods described in this study are rapid (less than 4 h), reproducible, simple and specific and demonstrate potential application in the clinical laboratory.

Rapid microwave-assisted synthesis of sub-30nm lipid nanoparticles.

PubMed

Dunn, Stuart S; Beckford Vera, Denis R; Benhabbour, S Rahima; Parrott, Matthew C

2017-02-15

Accessing the phase inversion temperature by microwave heating may enable the rapid synthesis of small lipid nanoparticles. Nanoparticle formulations consisted of surfactants Brij 78 and Vitamin E TPGS, and trilaurin, trimyristin, or miglyol 812 as nanoparticle lipid cores. Each formulation was placed in water and heated by microwave irradiation at temperatures ranging from 65°C to 245°C. We observed a phase inversion temperature (PIT) for these formulations based on a dramatic decrease in particle Z-average diameters. Subsequently, nanoparticles were manufactured above and below the PIT and studied for (a) stability toward dilution, (b) stability over time, (c) fabrication as a function of reaction time, and (d) transmittance of lipid nanoparticle dispersions. Lipid-based nanoparticles with distinct sizes down to 20-30nm and low polydispersity could be attained by a simple, one-pot microwave synthesis. This was carried out by accessing the phase inversion temperature using microwave heating. Nanoparticles could be synthesized in just one minute and select compositions demonstrated high stability. The notable stability of these particles may be explained by the combination of van der Waals interactions and steric repulsion. 20-30nm nanoparticles were found to be optically transparent. Published by Elsevier Inc.

Separation of oxalate, formate and glycolate in human body fluid samples by capillary electrophoresis with contactless conductometric detection.

PubMed

Kubáň, Petr; Ďurč, Pavol; Bittová, Miroslava; Foret, František

2014-01-17

A new method for rapid determination of toxic metabolites after methanol and ethylene glycol intoxication - oxalate, formate and glycolate in various body fluid samples (blood serum, saliva, urine, exhaled breath condensate) by capillary electrophoresis with contactless conductometric detection was developed. A selective separation of the three target analytes from other constituents present in the analyzed biological matrices was achieved in less than 6min in a fused silica capillary of 25μm I.D. using an electrolyte comprising 50mM l-histidine and 50mM 2-(N-morpholino)ethanesulfonic acid at pH 6.1. The only sample preparation was dilution with deionized water. The limits of detection were 0.4, 0.6 and 1.3μM and limits of quantitation 1.3, 1.9 and 4.2μM for oxalate, formate and glycolate, respectively. The method provides a simple and rapid diagnostic test in suspected intoxication and is able to distinguish the ingested liquid, based on its metabolite trace. The method presents a fast screening tool that can be applicable in clinical practice. Copyright © 2013 Elsevier B.V. All rights reserved.

Research of mine water source identification based on LIF technology

NASA Astrophysics Data System (ADS)

Zhou, Mengran; Yan, Pengcheng

2016-09-01

According to the problem that traditional chemical methods to the mine water source identification takes a long time, put forward a method for rapid source identification system of mine water inrush based on the technology of laser induced fluorescence (LIF). Emphatically analyzes the basic principle of LIF technology. The hardware composition of LIF system are analyzed and the related modules were selected. Through the fluorescence experiment with the water samples of coal mine in the LIF system, fluorescence spectra of water samples are got. Traditional water source identification mainly according to the ion concentration representative of the water, but it is hard to analysis the ion concentration of the water from the fluorescence spectra. This paper proposes a simple and practical method of rapid identification of water by fluorescence spectrum, which measure the space distance between unknown water samples and standard samples, and then based on the clustering analysis, the category of the unknown water sample can be get. Water source identification for unknown samples verified the reliability of the LIF system, and solve the problem that the current coal mine can't have a better real-time and online monitoring on water inrush, which is of great significance for coal mine safety in production.

Development and analysis of a tick-borne encephalitis virus infectious clone using a novel and rapid strategy.

PubMed

Gritsun, T S; Gould, E A

1998-12-01

In less than 1 month we have constructed an infectious clone of attenuated tick-borne encephalitis virus (strain Vasilchenko) from 100 microl of unpurified virus suspension using long high fidelity PCR and a modified bacterial cloning system. Optimization of the 3' antisense primer concentration was essential to achieve PCR synthesis of an 11 kb cDNA copy of RNA from infectious virus. A novel system utilising two antisense primers, a 14-mer for reverse transcription and a 35-mer for long PCR, produced high yields of genomic length cDNA. Use of low copy number Able K cells and an incubation temperature of 28 degrees C increased the genetic stability of cloned cDNA. Clones containing 11 kb cDNA inserts produced colonies of reduced size, thus providing a positive selection system for full length clones. Sequencing of the infectious clone emphasised the improved fidelity of the method compared with conventional PCR and cloning methods. A simple and rapid strategy for genetic manipulation of the infectious clone is also described. These developments represent a significant advance in recombinant technology and should be applicable to positive stranded RNA viruses which cannot easily be purified or genetically manipulated.

Rapid and reliable QuEChERS-based LC-MS/MS method for determination of acrylamide in potato chips and roasted coffee

NASA Astrophysics Data System (ADS)

Stefanović, S.; Đorđevic, V.; Jelušić, V.

2017-09-01

The aim of this paper is to verify the performance characteristics and fitness for purpose of rapid and simple QuEChERS-based LC-MS/MS method for determination of acrylamide in potato chips and coffee. LC-MS/MS is by far the most suitable analytical technique for acrylamide measurements given its inherent sensitivity and selectivity, as well as capability of analyzing underivatized molecule. Acrylamide in roasted coffee and potato chips wasextracted with water:acetonitrile mixture using NaCl and MgSO4. Cleanup was carried out with MgSO4 and PSA. Obtained results were satisfactory. Recoveries were in the range of 85-112%, interlaboratory reproducibility (Cv) was 5.8-7.6% and linearity (R2) was in the range of 0.995-0.999. LoQ was 35 μg kg-1 for coffee and 20 μg kg-1 for potato chips. Performance characteristic of the method are compliant with criteria for analytical methods validation. Presented method for quantitative determination of acrylamide in roasted coffee and potato chips is fit for purposes of self-control in food industry as well as regulatory controls carried out by the governmental agencies.

Rapid detection and quantification of 2,4-dichlorophenoxyacetic acid in milk using molecularly imprinted polymers-surface-enhanced Raman spectroscopy.

PubMed

Hua, Marti Z; Feng, Shaolong; Wang, Shuo; Lu, Xiaonan

2018-08-30

We report the development of a molecularly imprinted polymers-surface-enhanced Raman spectroscopy (MIPs-SERS) method for rapid detection and quantification of a herbicide residue 2,4-dichlorophenoxyacetic acid (2,4-D) in milk. MIPs were synthesized via bulk polymerization and utilized as solid phase extraction sorbent to selectively extract and enrich 2,4-D from milk. Silver nanoparticles were synthesized to facilitate the collection of SERS spectra of the extracts. Based on the characteristic band intensity of 2,4-D (391 cm -1 ), the limit of detection was 0.006 ppm and the limit of quantification was 0.008 ppm. A simple logarithmic working range (0.01-1 ppm) was established, satisfying the sensitivity requirement referring to the maximum residue level of 2,4-D in milk in both Europe and North America. The overall test of 2,4-D for each milk sample required only 20 min including sample preparation. This MIPs-SERS method has potential for practical applications in detecting 2,4-D in agri-foods. Copyright © 2018 Elsevier Ltd. All rights reserved.

The spreading of misinformation online.

PubMed

Del Vicario, Michela; Bessi, Alessandro; Zollo, Fabiana; Petroni, Fabio; Scala, Antonio; Caldarelli, Guido; Stanley, H Eugene; Quattrociocchi, Walter

2016-01-19

The wide availability of user-provided content in online social media facilitates the aggregation of people around common interests, worldviews, and narratives. However, the World Wide Web (WWW) also allows for the rapid dissemination of unsubstantiated rumors and conspiracy theories that often elicit rapid, large, but naive social responses such as the recent case of Jade Helm 15--where a simple military exercise turned out to be perceived as the beginning of a new civil war in the United States. In this work, we address the determinants governing misinformation spreading through a thorough quantitative analysis. In particular, we focus on how Facebook users consume information related to two distinct narratives: scientific and conspiracy news. We find that, although consumers of scientific and conspiracy stories present similar consumption patterns with respect to content, cascade dynamics differ. Selective exposure to content is the primary driver of content diffusion and generates the formation of homogeneous clusters, i.e., "echo chambers." Indeed, homogeneity appears to be the primary driver for the diffusion of contents and each echo chamber has its own cascade dynamics. Finally, we introduce a data-driven percolation model mimicking rumor spreading and we show that homogeneity and polarization are the main determinants for predicting cascades' size.

Tapping to a Slow Tempo in the Presence of Simple and Complex Meters Reveals Experience-Specific Biases for Processing Music

PubMed Central

Ullal-Gupta, Sangeeta; Hannon, Erin E.; Snyder, Joel S.

2014-01-01

Musical meters vary considerably across cultures, yet relatively little is known about how culture-specific experience influences metrical processing. In Experiment 1, we compared American and Indian listeners' synchronous tapping to slow sequences. Inter-tone intervals contained silence or to-be-ignored rhythms that were designed to induce a simple meter (familiar to Americans and Indians) or a complex meter (familiar only to Indians). A subset of trials contained an abrupt switch from one rhythm to another to assess the disruptive effects of contradicting the initially implied meter. In the unfilled condition, both groups tapped earlier than the target and showed large tap-tone asynchronies (measured in relative phase). When inter-tone intervals were filled with simple-meter rhythms, American listeners tapped later than targets, but their asynchronies were smaller and declined more rapidly. Likewise, asynchronies rose sharply following a switch away from simple-meter but not from complex-meter rhythm. By contrast, Indian listeners performed similarly across all rhythm types, with asynchronies rapidly declining over the course of complex- and simple-meter trials. For these listeners, a switch from either simple or complex meter increased asynchronies. Experiment 2 tested American listeners but doubled the duration of the synchronization phase prior to (and after) the switch. Here, compared with simple meters, complex-meter rhythms elicited larger asynchronies that declined at a slower rate, however, asynchronies increased after the switch for all conditions. Our results provide evidence that ease of meter processing depends to a great extent on the amount of experience with specific meters. PMID:25075514

Extraction and Chromatographic Determination of Shikimic Acid in Chinese Conifer Needles with 1-Benzyl-3-methylimidazolium Bromide Ionic Liquid Aqueous Solutions

PubMed Central

Chen, Fengli; Hou, Kexin; Li, Shuangyang; Zu, Yuangang; Yang, Lei

2014-01-01

An ionic liquids-based ultrasound-assisted extraction (ILUAE) method was successfully developed for extracting shikimic acid from conifer needles. Eleven 1-alkyl-3-methylimidazolium ionic liquids with different cations and anions were investigated and 1-benzyl-3-methylimidazolium bromide solution was selected as the solvent. The conditions for ILUAE, including the ionic liquid concentration, ultrasound power, ultrasound time, and liquid-solid ratio, were optimized. The proposed method had good recovery (99.37%–100.11%) and reproducibility (RSD, n = 6; 3.6%). ILUAE was an efficient, rapid, and simple sample preparation technique that showed high reproducibility. Based on the results, a number of plant species, namely, Picea koraiensis, Picea meyeri, Pinus elliottii, and Pinus banksiana, were identified as among the best resources of shikimic acid. PMID:24782942

Simultaneous determination of centchroman and tamoxifen along with their metabolites in rat plasma using LC-MS/MS.

PubMed

Rama Raju, Kanumuri Siva; Taneja, Isha; Singh, Sheelendra Pratap; Tripathi, Amit; Mishra, Durga Prasad; Hussain, K Mahaboob; Gayen, Jiaur Rahman; Singh, Shio Kumar; Wahajuddin, Muhammad

2015-01-01

Tamoxifen and centchroman are two non-steroidal, selective estrogen receptors modulators, intended for long term therapy in the woman. Because of their wide spread use, there is a possibility of co-prescription of these agents. We studied the probable pharmacokinetic interaction between these agents in breast cancer model rats. A simple, sensitive and rapid LC-ESI-MS/MS method was developed and validated for the simultaneous determination of tamoxifen, centchroman and their active metabolites. The method was linear over a range of 0.2-200 ng/ml. All validation parameters met the acceptance criteria according to regulatory guidelines. LC-MS/MS method for determination of tamoxifen, centchroman and their metabolites was developed and validated. Results show the potential of drug-drug interaction upon co-administration these two marketed drugs.

Complexation equilibria and spectrophotometric determination of iron(III) with 1-amino-4-hydroxyanthraquinone.

PubMed

Abu-Bakr, M S; Sedaira, H; Hashem, E Y

1994-10-01

The complex equilibria of iron(III) with 1-amino-4-hydroxyanthraquinone (AMHA) were studied spectrophotometrically in 40% (v/v) ethanol and an ionic strength of 0.1M (NaClO(4)). The complexation reactions were demonstrated and characterized using graphical logarithmic analysis of the absorbance-pH graphs. A simple, rapid, selective and sensitive method for the spectrophotometric determination of trace amounts of Fe(III) is developed based on the formation of Fe(AMHA) complex at pH 2.5 (lambda(max) = 640 nm, epsilon approximately = 2.1 x 10(4) L. mol(-1) . cm(-1)) in the presence of a large number of foreign ions. Interferences caused by palladium(II) was masked by the addition of cyanide ions. The method has been applied to the determination of iron in some synthetic samples and polymetallic iron ores.

Soft micromachines with programmable motility and morphology

PubMed Central

Huang, Hen-Wei; Sakar, Mahmut Selman; Petruska, Andrew J.; Pané, Salvador; Nelson, Bradley J.

2016-01-01

Nature provides a wide range of inspiration for building mobile micromachines that can navigate through confined heterogenous environments and perform minimally invasive environmental and biomedical operations. For example, microstructures fabricated in the form of bacterial or eukaryotic flagella can act as artificial microswimmers. Due to limitations in their design and material properties, these simple micromachines lack multifunctionality, effective addressability and manoeuvrability in complex environments. Here we develop an origami-inspired rapid prototyping process for building self-folding, magnetically powered micromachines with complex body plans, reconfigurable shape and controllable motility. Selective reprogramming of the mechanical design and magnetic anisotropy of body parts dynamically modulates the swimming characteristics of the micromachines. We find that tail and body morphologies together determine swimming efficiency and, unlike for rigid swimmers, the choice of magnetic field can subtly change the motility of soft microswimmers. PMID:27447088

Soft micromachines with programmable motility and morphology.

PubMed

Huang, Hen-Wei; Sakar, Mahmut Selman; Petruska, Andrew J; Pané, Salvador; Nelson, Bradley J

2016-07-22

Nature provides a wide range of inspiration for building mobile micromachines that can navigate through confined heterogenous environments and perform minimally invasive environmental and biomedical operations. For example, microstructures fabricated in the form of bacterial or eukaryotic flagella can act as artificial microswimmers. Due to limitations in their design and material properties, these simple micromachines lack multifunctionality, effective addressability and manoeuvrability in complex environments. Here we develop an origami-inspired rapid prototyping process for building self-folding, magnetically powered micromachines with complex body plans, reconfigurable shape and controllable motility. Selective reprogramming of the mechanical design and magnetic anisotropy of body parts dynamically modulates the swimming characteristics of the micromachines. We find that tail and body morphologies together determine swimming efficiency and, unlike for rigid swimmers, the choice of magnetic field can subtly change the motility of soft microswimmers.

Talking Wheelchair

NASA Technical Reports Server (NTRS)

1981-01-01

Communication is made possible for disabled individuals by means of an electronic system, developed at Stanford University's School of Medicine, which produces highly intelligible synthesized speech. Familiarly known as the "talking wheelchair" and formally as the Versatile Portable Speech Prosthesis (VPSP). Wheelchair mounted system consists of a word processor, a video screen, a voice synthesizer and a computer program which instructs the synthesizer how to produce intelligible sounds in response to user commands. Computer's memory contains 925 words plus a number of common phrases and questions. Memory can also store several thousand other words of the user's choice. Message units are selected by operating a simple switch, joystick or keyboard. Completed message appears on the video screen, then user activates speech synthesizer, which generates a voice with a somewhat mechanical tone. With the keyboard, an experienced user can construct messages as rapidly as 30 words per minute.

Evaluation of selected spectral vegetation indices in senescent rangeland canopy using Landsat imagery

NASA Astrophysics Data System (ADS)

Striped Face-Collins, Marla

Grassland birds are diminishing more steadily and rapidly than other North American birds in general. The nesting success of some grassland bird species depends on the amount of nonproductive vegetation (NPV). To estimate NPV land managers are currently using the Robel pole visual obstruction reading methods. Researchers with the USDA Agricultural Research Service's (ARS) Northern Great Plains Research Laboratory in Mandan, ND, recently established statistical relationships between photosynthetic vegetation (PV), NPV and spectral vegetation indices (SVIs) derived from more sensitive and more detailed, but less accessible and more costly hyperspectral aerial imagery. This study is an extension of this previous work using spectral vegetation indices collected using the Landsat TM sensor, including simple ratios SWIR-SR (rho2215/rho 1650) and SR71 (rho2215 /rho485) to estimate the amount of NPV and bare ground cover, respectively.

Factors determining antibody distribution in tumors.

PubMed

Thurber, Greg M; Schmidt, Michael M; Wittrup, K Dane

2008-02-01

The development of antibody therapies for cancer is increasing rapidly, primarily owing to their specificity. Antibody distribution in tumors is often extremely uneven, however, leading to some malignant cells being exposed to saturating concentrations of antibody, whereas others are completely untargeted. This is detrimental because large regions of cells escape therapy, whereas other regions might be exposed to suboptimal concentrations that promote a selection of resistant mutants. The distribution of antibody depends on a variety of factors, including dose, affinity, antigens per cell and molecular size. Because these parameters are often known or easily estimated, a quick calculation based on simple modeling considerations can predict the uniformity of targeting within a tumor. Such analyses should enable experimental researchers to identify in a straightforward way the limitations in achieving evenly distributed antibody, and design and test improved antibody therapeutics more rationally.

Factors determining antibody distribution in tumors

PubMed Central

Thurber, Greg M.; Schmidt, Michael M.; Wittrup, K. Dane

2009-01-01

The development of antibody therapies for cancer is increasing rapidly, primarily owing to their specificity. Antibody distribution in tumors is often extremely uneven, however, leading to some malignant cells being exposed to saturating concentrations of antibody, whereas others are completely untargeted. This is detrimental because large regions of cells escape therapy, whereas other regions might be exposed to suboptimal concentrations that promote a selection of resistant mutants. The distribution of antibody depends on a variety of factors, including dose, affinity, antigens per cell and molecular size. Because these parameters are often known or easily estimated, a quick calculation based on simple modeling considerations can predict the uniformity of targeting within a tumor. Such analyses should enable experimental researchers to identify in a straightforward way the limitations in achieving evenly distributed antibody, and design and test improved antibody therapeutics more rationally. PMID:18179828

Colour reaction of gold with 5-(4-sodium sulphonatephenylazo)-8-aminoquinoline and its analytical application.

PubMed

Zeng, Z; Xu, Q

1992-04-01

The synthesis of 5-(4-sodium sulphonatephenylazo)-8-aminoquinoline (SPAQ) is described, and a simple, rapid, selective and sensitive new spectrophotometric method for determination of gold is developed. SPAQ reacts with gold(III), and in the presence of cetyl trimethyl ammonium bromide cationic surfactant and upon making the solution alkaline, forms a blue-green 1:3 (metal:ligand) with an absorption maximum at 605 nm. Beer's law is obeyed over the concentration range 0-2 microg/ml gold. The molar absorptivity and Sandell's sensitivity of the method are 1.48 x 10(5) 1.mole(-1).cm(-1) and 0.0013 microg/cm(2), respectively. The interference of various ions has been studied and the method has been used for the determination of microamounts of gold in ores and anode slimes.

HCMM satellite follow-on investigation no. 25. Soil moisture and heat budget evalution in selected European zones of agricultural and environmental interest (TELLUS project)

NASA Technical Reports Server (NTRS)

1980-01-01

A simple procedure to evaluate actual evaporation was derived by linearizing the surface energy balance equation, using Taylor's expansion. The original multidimensional hypersurface could be reduced to a linear relationship between evaporation and surface temperature or to a surface relationship involving evaporation, surface temperature and albedo. This procedure permits a rapid sensitivity analysis of the surface energy balance equation as well as a speedy mapping of evaporation from remotely sensed surface temperatures and albedo. Comparison with experimental data yielded promising results. The validity of evapotranspiration and soil moisture models in semiarid conditions was tested. Wheat was the crop chosen for a continuous measurement campaign made in the south of Italy. Radiometric, micrometeorologic, agronomic and soil data were collected for processing and interpretation.

Recent Application of Solid Phase Based Techniques for Extraction and Preconcentration of Cyanotoxins in Environmental Matrices.

PubMed

Mashile, Geaneth Pertunia; Nomngongo, Philiswa N

2017-03-04

Cyanotoxins are toxic and are found in eutrophic, municipal, and residential water supplies. For this reason, their occurrence in drinking water systems has become a global concern. Therefore, monitoring, control, risk assessment, and prevention of these contaminants in the environmental bodies are important subjects associated with public health. Thus, rapid, sensitive, selective, simple, and accurate analytical methods for the identification and determination of cyanotoxins are required. In this paper, the sampling methodologies and applications of solid phase-based sample preparation methods for the determination of cyanotoxins in environmental matrices are reviewed. The sample preparation techniques mainly include solid phase micro-extraction (SPME), solid phase extraction (SPE), and solid phase adsorption toxin tracking technology (SPATT). In addition, advantages and disadvantages and future prospects of these methods have been discussed.

Simultaneous determination of epinephrene and paracetamol at copper-cobalt oxide spinel decorated nanocrystalline zeolite modified electrodes.

PubMed

Samanta, Subhajyoti; Srivastava, Rajendra

2016-08-01

In this study, CuCo2O4 and CuCo2O4 decorated nanocrystalline ZSM-5 materials were prepared. For comparative study, a series of MCo2O4 spinels were also prepared. Materials were characterized by the complementary combination of X-ray diffraction, N2-adsorption, UV-visible, and electron microscopic techniques. A simple and rapid method for the simultaneous determination of paracetamol and epinephrine at MCo2O4 spinels modified electrodes is presented in this manuscript. Among the materials investigated in this study, CuCo2O4 decorated nanocrystalline ZSM-5 exhibited the highest electrocatalytic activity with excellent stability, sensitivity, and selectivity. Analytical performance of the sensor was demonstrated in the determination of epinephrine and paracetamol in the commercial pharmaceutical samples. Copyright © 2016 Elsevier Inc. All rights reserved.

Rapid determination of cell mass and density using digitally controlled electric field in a microfluidic chip.

PubMed

Zhao, Yuliang; Lai, Hok Sum Sam; Zhang, Guanglie; Lee, Gwo-Bin; Li, Wen Jung

2014-11-21

The density of a single cell is a fundamental property of cells. Cells in the same cycle phase have similar volume, but the differences in their mass and density could elucidate each cell's physiological state. Here we report a novel technique to rapidly measure the density and mass of a single cell using an optically induced electrokinetics (OEK) microfluidic platform. Presently, single cellular mass and density measurement devices require a complicated fabrication process and their output is not scalable, i.e., it is extremely difficult to measure the mass and density of a large quantity of cells rapidly. The technique reported here operates on a principle combining sedimentation theory, computer vision, and microparticle manipulation techniques in an OEK microfluidic platform. We will show in this paper that this technique enables the measurement of single-cell volume, density, and mass rapidly and accurately in a repeatable manner. The technique is also scalable - it allows simultaneous measurement of volume, density, and mass of multiple cells. Essentially, a simple time-controlled projected light pattern is used to illuminate the selected area on the OEK microfluidic chip that contains cells to lift the cells to a particular height above the chip's surface. Then, the cells are allowed to "free fall" to the chip's surface, with competing buoyancy, gravitational, and fluidic drag forces acting on the cells. By using a computer vision algorithm to accurately track the motion of the cells and then relate the cells' motion trajectory to sedimentation theory, the volume, mass, and density of each cell can be rapidly determined. A theoretical model of micro-sized spheres settling towards an infinite plane in a microfluidic environment is first derived and validated experimentally using standard micropolystyrene beads to demonstrate the viability and accuracy of this new technique. Next, we show that the yeast cell volume, mass, and density could be rapidly determined using this technology, with results comparable to those using the existing method suspended microchannel resonator.

Rapid development of new protein biosensors utilizing peptides obtained via phage display.

PubMed

Wu, Jun; Park, Jong Pil; Dooley, Kevin; Cropek, Donald M; West, Alan C; Banta, Scott

2011-01-01

There is a consistent demand for new biosensors for the detection of protein targets, and a systematic method for the rapid development of new sensors is needed. Here we present a platform where short unstructured peptides that bind to a desired target are selected using M13 phage display. The selected peptides are then chemically synthesized and immobilized on gold, allowing for detection of the target using electrochemical techniques such as electrochemical impedance spectroscopy (EIS). A quartz crystal microbalance (QCM) is also used as a diagnostic tool during biosensor development. We demonstrate the utility of this approach by creating a novel peptide-based electrochemical biosensor for the enzyme alanine aminotransferase (ALT), a well-known biomarker of hepatotoxicity. Biopanning of the M13 phage display library over immobilized ALT, led to the rapid identification of a new peptide (ALT5-8) with an amino acid sequence of WHWRNPDFWYLK. Phage particles expressing this peptide exhibited nanomolar affinity for immobilized ALT (K(d,app) = 85±20 nM). The newly identified ALT5-8 peptide was then chemically synthesized with a C-terminal cysteine for gold immobilization. The performance of the gold-immobilized peptides was studied with cyclic voltammetry (CV), QCM, and EIS. Using QCM, the sensitivity for ALT detection was 8.9±0.9 Hz/(µg/mL) and the limit of detection (LOD) was 60 ng/mL. Using EIS measurements, the sensitivity was 142±12 impedance percentage change %/(µg/mL) and the LOD was 92 ng/mL. In both cases, the LOD was below the typical concentration of ALT in human blood. Although both QCM and EIS produced similar LODs, EIS is preferable due to a larger linear dynamic range. Using QCM, the immobilized peptide exhibited a nanomolar dissociation constant for ALT (K(d) = 20.1±0.6 nM). These results demonstrate a simple and rapid platform for developing and assessing the performance of sensitive, peptide-based biosensors for new protein targets.

A new disposable electrode for electrochemical study of leukemia K562 cells and anticancer drug sensitivity test.

PubMed

Yu, Chunmei; Zhu, Zhenkun; Wang, Li; Wang, Qiuhong; Bao, Ning; Gu, Haiying

2014-03-15

Developing cost-effective and simple analysis tools is of vital importance for practical applications in bioanalysis. In this work, a new disposable electrochemical cell sensor with low cost and simple fabrication was proposed to study the electrochemical behavior of leukemia K562 cells and the effect of anticancer drugs on cell viability. The analytical device was integrated by using ITO glass as the substrate of working electrodes and paper as the electrolytic cell. The cyclic voltammetry of the K562 cells at the disposable electrode exhibited an irreversible anodic peak and the peak current is proportional to the cell number. This anodic peak is attributed to the oxidation of guanine in cells involving two protons per transfer of two electrons. For the drug sensitivity tests, arsenic trioxide and cyclophosphamide were added to cell culture media. As a result, the electrochemical responses of the K562 cells decreased significantly. The cytotoxicity curves and results obtained corresponded well with the results of CCK-8 assays. In comparison to conventional methods, the proposed method is simple, rapid and inexpensive. More importantly, the developed sensor is supposed to be a single-use disposable device and electrodes were prepared "as new" for each experiment. We think that such disposable electrodes with these characteristics are suitable for experimental study with cancer cells or other types of pathogens for disease diagnosis, drug selection and on-site monitoring. © 2013 Elsevier B.V. All rights reserved.

A Rapid and Simple Real-Time PCR Assay for Detecting Foodborne Pathogenic Bacteria in Human Feces.

PubMed

Hanabara, Yutaro; Ueda, Yutaka

2016-11-22

A rapid, simple method for detecting foodborne pathogenic bacteria in human feces is greatly needed. Here, we examined the efficacy of a method that employs a combination of a commercial PCR master mix, which is insensitive to PCR inhibitors, and a DNA extraction method which used sodium dodecyl benzene sulfonate (SDBS), and Tween 20 to counteract the inhibitory effects of SDBS on the PCR assay. This method could detect the target genes (stx1 and stx2 of enterohemorrhagic Escherichia coli, invA of Salmonella Enteritidis, tdh of Vibrio parahaemolyticus, gyrA of Campylobacter jejuni, ceuE of Campylobacter coli, SEA of Staphylococcus aureus, ces of Bacillus cereus, and cpe of Clostridium perfringens) in a fecal suspension containing 1.0 × 10 1 to 1.0 × 10 3 CFU/ml. Furthermore, the assay was neither inhibited nor influenced by individual differences among the fecal samples of 10 subjects or fecal concentration (40-160 mg/ml in the fecal suspension). When we attempted to detect the genes of pathogenic bacteria in 4 actual clinical cases, we found that this method was more sensitive than standard culture method. These results showed that this assay is a rapid, simple detection method for foodborne pathogenic bacteria in human feces.

De novo balanced complex chromosome rearrangements involving chromosomes 1B and 3B of wheat and 1R of rye.

PubMed

Ren, Tianheng; Li, Zhi; Yan, Benju; Tan, Feiquan; Tang, Zongxiang; Fu, Shulan; Yang, Manyu; Ren, Zhenglong

2016-12-01

Complex chromosome rearrangements (CCRs) are defined as structural abnormalities involving more than two chromosome breaks, coupled with exchanges of chromosomal segments. Information on CCRs in plants is limited. In the present study, a plant (26-4) harboring translocation chromosomes 1RS.1BL and 4RS.4DL was selected from a double monosomic (1R and 4R) addition line, which was derived from the hybrid between wheat cultivar MY11 and a Chinese local rye variety. The genome of the plant with double alien translocation chromosomes in the monosomic form showed more instability than that harboring a single translocation. The CCRs involving chromosomes 1RS.1BL and 3B, which were generated de novo in this plant, showed double monosomic translocation chromosomes. A new CCR line with balanced reciprocal translocations 1RS.3BL and 3BS.1BL was developed, which presented normal morphological traits of wheat and underwent rapid growth in the field. A new 1RS.1BL translocation line was also selected from the progeny of plant 26-4. The CCRs and simple 1RS.1BL translocation lines showed significant improvement in grain yield, number of spikes per square meter, kernel number per spike, and resistance to stripe rust and powdery mildew. The CCR line exhibited better agronomic traits and adult plant resistance in the field than its sister line, which harbored a simple 1RS.1BL translocation. The CCRs are remarkable genetic resources for crop improvement.

Positive feedback in the transition from sexual reproduction to parthenogenesis

PubMed Central

Schwander, Tanja; Vuilleumier, Séverine; Dubman, Janie; Crespi, Bernard J.

2010-01-01

Understanding how new phenotypes evolve is challenging because intermediate stages in transitions from ancestral to derived phenotypes often remain elusive. Here we describe and evaluate a new mechanism facilitating the transition from sexual reproduction to parthenogenesis. In many sexually reproducing species, a small proportion of unfertilized eggs can hatch spontaneously (‘tychoparthenogenesis’) and develop into females. Using an analytical model, we show that if females are mate-limited, tychoparthenogenesis can result in the loss of males through a positive feedback mechanism whereby tychoparthenogenesis generates female-biased sex ratios and increasing mate limitation. As a result, the strength of selection for tychoparthenogenesis increases in concert with the proportion of tychoparthenogenetic offspring in the sexual population. We then tested the hypothesis that mate limitation selects for tychoparthenogenesis and generates female-biased sex ratios, using data from natural populations of sexually reproducing Timema stick insects. Across 41 populations, both the tychoparthenogenesis rates and the proportions of females increased exponentially as the density of individuals decreased, consistent with the idea that low densities of individuals result in mate limitation and selection for reproductive insurance through tychoparthenogenesis. Our model and data from Timema populations provide evidence for a simple mechanism through which parthenogenesis can evolve rapidly in a sexual population. PMID:20071382

One-step synthesis of fluorescent carbon dots for sensitive and selective detection of hyperin.

PubMed

Liu, Lizhen; Mi, Zhi; Hu, Qin; Li, Caiqing; Li, Xiaohua; Feng, Feng

2018-08-15

In this article, we presented a new rapid, sensitive and selective method for the determination of hyperin (Hyp) based on the fluorescence quenching of fluorescent carbon dots (CDs). The CDs were prepared by simply mixing an aqueous solution of citric acid with diphosphorus pentoxide. This one-step synthetic route is fast and simple with neither high temperature nor complicated synthesis steps is involved. When Hyp was added to CDs solution, the fluorescence intensity of the CDs significantly decreased. The CDs display high selectivity for Hyp over many potentially interfering substances. Under the optimized conditions, a good linear relationship between the fluorescence intensity ratio F o /F and the concentration of Hyp is obtained in a range of 0.22-55 µM with a detection limit (S/N = 3) of 78.3 nM. The method was successfully applied for the determination of Hyp in fufangmuji granules and human serum samples with recoveries in a range of 93.3-107.0%. This paper highlights the usefulness of CDs as an effective fluorescence probe for the Hyp detection due to its easy preparation, low-cost, excellent photostability, favorable biocompatibility and low cytotoxicity. Copyright © 2018 Elsevier B.V. All rights reserved.

Catalytic allylic oxidation of internal alkenes to a multifunctional chiral building block

NASA Astrophysics Data System (ADS)

Bayeh, Liela; Le, Phong Q.; Tambar, Uttam K.

2017-07-01

The stereoselective oxidation of hydrocarbons is one of the most notable advances in synthetic chemistry over the past fifty years. Inspired by nature, enantioselective dihydroxylations, epoxidations and other oxidations of unsaturated hydrocarbons have been developed. More recently, the catalytic enantioselective allylic carbon-hydrogen oxidation of alkenes has streamlined the production of pharmaceuticals, natural products, fine chemicals and other functional materials. Allylic functionalization provides a direct path to chiral building blocks with a newly formed stereocentre from petrochemical feedstocks while preserving the olefin functionality as a handle for further chemical elaboration. Various metal-based catalysts have been discovered for the enantioselective allylic carbon-hydrogen oxidation of simple alkenes with cyclic or terminal double bonds. However, a general and selective allylic oxidation using the more common internal alkenes remains elusive. Here we report the enantioselective, regioselective and E/Z-selective allylic oxidation of unactivated internal alkenes via a catalytic hetero-ene reaction with a chalcogen-based oxidant. Our method enables non-symmetric internal alkenes to be selectively converted into allylic functionalized products with high stereoselectivity and regioselectivity. Stereospecific transformations of the resulting multifunctional chiral building blocks highlight the potential for rapidly converting internal alkenes into a broad range of enantioenriched structures that can be used in the synthesis of complex target molecules.

Selection rule engineering of forbidden transitions of a hydrogen atom near a nanogap

NASA Astrophysics Data System (ADS)

Kim, Hyunyoung Y.; Kim, Daisik S.

2018-01-01

We perform an analytical study on the allowance of forbidden transitions for a hydrogen atom placed near line dipole sources, mimicking light emanating from a one-dimensional metallic nanogap. It is shown that the rapid variation of the electric field vector, inevitable in the near zone, completely breaks the selection rule of Δl=±1. While the forbidden transitions between spherically symmetric S states, such as 2S to 1S or 3S to 1S (Δl=0), are rather robust against selection rule breakage, Δl=±2 transitions such as between 3D and 1S or 3D and 2S states are very vulnerable to the spatial variation of the perturbing electric field. Transitions between 2S and 3D states are enhanced by many orders of magnitude, aided by the quadratic nature of both the perturbing Hamiltonian and D wavefunctions. The forbidden dipole moment, which approaches one Bohr radius times the electric charge in the vicinity of the gap, can be written in a simple closed form owing to the one-dimensional nature of our gap. With large enough effective volume together with the symmetric nature of the excited state wavefunctions, our work paves way towards atomic physics application of infinitely long nanogaps.

Rapid cycling genomic selection in a multiparental tropical maize population

USDA-ARS?s Scientific Manuscript database

Genomic selection (GS) increases genetic gain by reducing the length of the selection cycle, as has been exemplified in maize using rapid cycling recombination of biparental populations. However, no results of GS applied to maize multi-parental populations have been reported so far. This study is th...

A simple model of hohlraum power balance and mitigation of SRS

DOE PAGES

Albright, Brian J.; Montgomery, David S.; Yin, Lin; ...

2016-04-01

A simple energy balance model has been obtained for laser-plasma heating in indirect drive hohlraum plasma that allows rapid temperature scaling and evolution with parameters such as plasma density and composition. Furthermore, this model enables assessment of the effects on plasma temperature of, e.g., adding high-Z dopant to the gas fill or magnetic fields.

A Simple Experiment for Visualizing Diffusion

ERIC Educational Resources Information Center

Helseth, L. E.

2011-01-01

We propose a simple and fascinating experiment for studying diffusion in gels using a pH-sensitive dye. By doping agar with methyl red, we obtain a gel which rapidly reacts to changes in pH by changing its absorption spectrum. The pH gradients can be followed using a digital camera, and we demonstrate here that the pH-sensitive colour changes can…

Evaluation of a simple phenotypic method for the detection of carbapenemase-producing Enterobacteriaceae.

PubMed

Saito, Ryoichi; Koyano, Saho; Dorin, Misato; Higurashi, Yoshimi; Misawa, Yoshiki; Nagano, Noriyuki; Kaneko, Takamasa; Moriya, Kyoji

2015-01-01

We investigated the performance of a phenotypic test, the Carbapenemase Detection Set (MAST-CDS), for the identification of carbapenemase-producing Enterobacteriaceae. Our results indicated that MAST-CDS is rapid, easily performed, simple to interpret, and highly sensitive for the identification of carbapenemase producers, particularly imipenemase producers. Copyright © 2014 Elsevier B.V. All rights reserved.

A simple quality assurance test tool for the visual verification of light and radiation field congruent using electronic portal images device and computed radiography

PubMed Central

2012-01-01

Background The radiation field on most megavoltage radiation therapy units are shown by a light field projected through the collimator by a light source mounted inside the collimator. The light field is traditionally used for patient alignment. Hence it is imperative that the light field is congruent with the radiation field. Method A simple quality assurance tool has been designed for rapid and simple test of the light field and radiation field using electronic portal images device (EPID) or computed radiography (CR). We tested this QA tool using Varian PortalVision and Elekta iViewGT EPID systems and Kodak CR system. Results Both the single and double exposure techniques were evaluated, with double exposure technique providing a better visualization of the light-radiation field markers. The light and radiation congruency could be detected within 1 mm. This will satisfy the American Association of Physicists in Medicine task group report number 142 recommendation of 2 mm tolerance. Conclusion The QA tool can be used with either an EPID or CR to provide a simple and rapid method to verify light and radiation field congruence. PMID:22452821

Ebolavirus diagnosis made simple, comparable and faster than molecular detection methods: preparing for the future.

PubMed

James, Ameh S; Todd, Shawn; Pollak, Nina M; Marsh, Glenn A; Macdonald, Joanne

2018-04-23

The 2014/2015 Ebolavirus outbreak resulted in more than 28,000 cases and 11,323 reported deaths, as of March 2016. Domestic transmission of the Guinea strain associated with the outbreak occurred mainly in six African countries, and international transmission was reported in four countries. Outbreak management was limited by the inability to rapidly diagnose infected cases. A further fifteen countries in Africa are predicted to be at risk of Ebolavirus outbreaks in the future as a consequence of climate change and urbanization. Early detection of cases and reduction of transmission rates is critical to prevent and manage future severe outbreaks. We designed a rapid assay for detection of Ebolavirus using recombinase polymerase amplification, a rapid isothermal amplification technology that can be combined with portable lateral flow detection technology. The developed rapid assay operates in 30 min and was comparable with real-time TaqMan™ PCR. Designed, screened, selected and optimized oligonucleotides using the NP coding region from Ebola Zaire virus (Guinea strain). We determined the analytical sensitivity of our Ebola rapid molecular test by testing selected primers and probe with tenfold serial dilutions (1.34 × 10 10-  1.34 × 10 1 copies/μL) of cloned NP gene from Mayinga strain of Zaire ebolavirus in pCAGGS vector, and serially diluted cultured Ebolavirus as established by real-time TaqMan™ PCR that was performed using ABI7500 in Fast Mode. We tested extracted and reverse transcribed RNA from cultured Zaire ebolavirus strains - Mayinga, Gueckedou C05, Gueckedou C07, Makona, Kissidougou and Kiwit. We determined the analytical specificity of our assay with related viruses: Marburg, Ebola Reston and Ebola Sudan. We further tested for Dengue virus 1-4, Plasmodium falciparum and West Nile Virus (Kunjin strain). The assay had a detection limit of 134 copies per μL of plasmid containing the NP gene of Ebolavirus Mayinga, and cultured Ebolavirus and was highly specific for the Zaire ebolavirus species, including the Guinea strain responsible for the 2014/2015 outbreak. The assay did not detect related viruses like Marburg, Reston, or Sudan viruses, and other pathogens likely to be isolated from clinical samples. Our assay could be suitable for implementation in district and primary health laboratories, as only a heating block and centrifuge is required for operation. The technique could provide a pathway for rapid screening of patients and animals for improved management of outbreaks.

Rapid e-Learning Tools Selection Process for Cognitive and Psychomotor Learning Objectives

ERIC Educational Resources Information Center

Ku, David Tawei; Huang, Yung-Hsin

2012-01-01

This study developed a decision making process for the selection of rapid e-learning tools that could match different learning domains. With the development of the Internet, the speed of information updates has become faster than ever. E-learning has rapidly become the mainstream for corporate training and academic instruction. In order to reduce…

Piezoelectric translator. A simple and inexpensive device to move microelectrodes and micropipettes small distances rapidly.

PubMed

Lederer, W J

1983-09-01

A device is described that is capable of rapidly moving microelectrodes and micropipettes over distances up to 15 mu. This piezoelectric transLator uses the diaphragm from virtually any available piezoelectric buzzer in combination with simple physical support and drive electronics. All of the necessary details for the construction of this small device are presented. Each finished unit is about 2 cm long with a diameter of 2 cm and can be readily adapted to existing manipulators. The translator has been found useful in aiding the independent penetration by one or more microelectrodes of single cells or of more complicated multicellular preparations (including those that lie behind a connective tissue layer). This new device offers fine control of microelectrode motion that cannot be obtained by the other methods used to aid microelectrode and micropipette penetration of cell membranes (e.g. capacitance overcompensation--"ringing in"' or "tickling"--or tapping the manipulator base). Finally, the device described in this paper is extremely simple and inexpensive to build.

Tracking the quality of care for sick children using lot quality assurance sampling: targeting improvements of health services in Jigawa, Nigeria.

PubMed

Oladele, Edward Adekola; Ormond, Louise; Adeyemi, Olusegun; Patrick, David; Okoh, Festus; Oresanya, Olusola Bukola; Valadez, Joseph J

2012-01-01

In Nigeria, 30% of child deaths are due to malaria. The National Malaria Control Program of Nigeria (NMCP) during 2009 initiated a program to improve the quality of paediatric malaria services delivered in health facilities (HF). This study reports a rapid approach used to assess the existing quality of services in Jigawa state at decentralised levels of the health system. NMCP selected Lot Quality Assurance Sampling (LQAS) to identify the variation in HF service quality among Senatorial Districts (SD). LQAS was selected because it was affordable and could be used by local health workers (HW) in a population-based survey. NMCP applied a 2-stage LQAS using a structured Rapid Health Facility Assessment (R-HFA) tool to identify high and low performing SD for specified indicators. LQAS identified variations in HF performance (n = 21) and enabled resources to be targeted to address priorities. All SD exhibited deficient essential services, supplies and equipment. Only 9.7% of HF had Artemisinin-based Combination Therapies and other first-line treatments for childhood illnesses. No SD and few HF exhibited adequate HW performance for the assessment, treatment or counselling of sick children. Using the IMCI algorithm, 17.5% of HW assessed the child's vaccination status, 46.8% assessed nutritional status, and 65.1% assessed children for dehydration. Only 5.1% of HW treatments were appropriate for the assessment. Exit interviews revealed that 5.1% of caregivers knew their children's illness, and only 19.9% could accurately describe how to administer the prescribed drug. This R-HFA, using LQAS principles, is a rapid, simple tool for assessing malaria services and can be used at scale. It identified technical deficiencies that could be corrected by improved continuing medical education, targeted supervision, and recurrent R-HFA assessments of the quality of services.

Tracking the Quality of Care for Sick Children Using Lot Quality Assurance Sampling: Targeting Improvements of Health Services in Jigawa, Nigeria

PubMed Central

Oladele, Edward Adekola; Ormond, Louise; Adeyemi, Olusegun; Patrick, David; Okoh, Festus; Oresanya, Olusola Bukola; Valadez, Joseph J.

2012-01-01

Background In Nigeria, 30% of child deaths are due to malaria. The National Malaria Control Program of Nigeria (NMCP) during 2009 initiated a program to improve the quality of paediatric malaria services delivered in health facilities (HF). This study reports a rapid approach used to assess the existing quality of services in Jigawa state at decentralised levels of the health system. Methods NMCP selected Lot Quality Assurance Sampling (LQAS) to identify the variation in HF service quality among Senatorial Districts (SD). LQAS was selected because it was affordable and could be used by local health workers (HW) in a population-based survey. NMCP applied a 2-stage LQAS using a structured Rapid Health Facility Assessment (R-HFA) tool to identify high and low performing SD for specified indicators. Findings LQAS identified variations in HF performance (n = 21) and enabled resources to be targeted to address priorities. All SD exhibited deficient essential services, supplies and equipment. Only 9.7% of HF had Artemisinin-based Combination Therapies and other first-line treatments for childhood illnesses. No SD and few HF exhibited adequate HW performance for the assessment, treatment or counselling of sick children. Using the IMCI algorithm, 17.5% of HW assessed the child’s vaccination status, 46.8% assessed nutritional status, and 65.1% assessed children for dehydration. Only 5.1% of HW treatments were appropriate for the assessment. Exit interviews revealed that 5.1% of caregivers knew their children’s illness, and only 19.9% could accurately describe how to administer the prescribed drug. Conclusion This R-HFA, using LQAS principles, is a rapid, simple tool for assessing malaria services and can be used at scale. It identified technical deficiencies that could be corrected by improved continuing medical education, targeted supervision, and recurrent R-HFA assessments of the quality of services. PMID:23028519

Extraction Optimization for Phenolic- and Withanolide-Rich Fractions from Withania somnifera Roots: Identification and Quantification of Withaferin A, 12-Deoxywithastromonolide, and Withanolide A in Plant Materials and Marketed Formulations Using a Reversed-Phase HPLC-Photodiode Array Detection Method.

PubMed

Kumar, Satyanshu; Singh, Raghuraj; Gajbhiye, Narendra; Dhanani, Tushar

2018-06-26

Background : Both the roots and leaves of Withania somnifera are products of commerce. They contain active compounds of therapeutic value and mostly different withanolides. Several pharmacological activities of W. somnifera have links to one or more withanolides. The presence of phenolic compounds in extracts could play a vital role in the reduction of blood glucose levels in diabetic subjects. Objective : The present study was carried out for the selection of a solvent to prepare extracts rich in phenolics, withaferin A (WA), 12-deoxywithastromonolide (12WD), and withanolide A (WDA). A simple, rapid HPLC method was also developed for the identification and quantification of WA, 12WD, and WDA. Methods : The extraction efficiency of aqueous alcoholic solvents including hexane, chloroform, ethyl acetate, and methanol were compared for three selected withanolides and total phenolic content. The contents of WA, 12WD, and WDA and total phenolics were determined in the extracts. The quality of nine formulations containing W. sominfera were also compared in terms of the content of WA, 12WD, and WDA and total phenolics. Results : The maximum extract yield and the total withanolide and phenolic content were obtained from aqueous alcoholic compositions at 50:50 (v/v), 70:30 (v/v), and 100:0 (v/v), respectively. In the case of organic solvents, chloroform and ethyl acetate yielded the highest concentrations of phenolics and three withanolides, respectively. The total phenolic content in formulations was in the range of 1.84-3.13%, and total withanolide content showed wide variability. Conclusions : The outcome of the present investigation could be utilized for the selection of extraction solvents to prepare W. somnifera -enriched extracts and their quality monitoring by using the developed and validated HPLC-Photodiode array detection method. Highlights : A process for preparation of phenolics and withanolides (withaferin A, 12-deoxywithastramonolide and withanolide A) enriched extracts of Withania somnifera . Simple and rapid HPLC method was also developed and validated as per the ICH guidelines for identification and quantification of three major withanolides. The developed HPLC method was applied to analyze the quality of extracts and marketed herbal products (mono, as well as poly constituents). Optimized extraction process could be utilized for upscaling process development in preparation of enriched extracts from Withania somnifera , crop improvement, bio-prospection studies and quality control.

The Impact of Presentation Format on Younger and Older Adults' Self-Regulated Learning.

PubMed

Price, Jodi

2017-01-01

Background/Study Context: Self-regulated learning involves deciding what to study and for how long. Debate surrounds whether individuals' selections are influenced more by item complexity, point values, or if instead people select in a left-to-right reading order, ignoring item complexity and value. The present study manipulated whether point values and presentation format favored selection of simple or complex Chinese-English pairs to assess the impact on younger and older adults' selection behaviors. One hundred and five younger (M age  = 20.26, SD = 2.38) and 102 older adults (M age  = 70.28, SD = 6.37) participated in the experiment. Participants studied four different 3 × 3 grids (two per trial), each containing three simple, three medium, and three complex Chinese-English vocabulary pairs presented in either a simple-first or complex-first order, depending on condition. Point values were assigned in either a 2-4-8 or 8-4-2 order so that either simple or complex items were favored. Points did not influence the order in which either age group selected items, whereas presentation format did. Younger and older adults selected more simple or complex items when they appeared in the first column. However, older adults selected and allocated more time to simpler items but recalled less overall than did younger adults. Memory beliefs and working memory capacity predicted study time allocation, but not item selection, behaviors. Presentation format must be considered when evaluating which theory of self-regulated learning best accounts for younger and older adults' study behaviors and whether there are age-related differences in self-regulated learning. The results of the present study combine with others to support the importance of also considering the role of external factors (e.g., working memory capacity and memory beliefs) in each age group's self-regulated learning decisions.

Simple Copper Catalysts for the Aerobic Oxidation of Amines: Selectivity Control by the Counterion.

PubMed

Xu, Boran; Hartigan, Elizabeth M; Feula, Giancarlo; Huang, Zheng; Lumb, Jean-Philip; Arndtsen, Bruce A

2016-12-19

We describe the use of simple copper-salt catalysts in the selective aerobic oxidation of amines to nitriles or imines. These catalysts are marked by their exceptional efficiency, operate at ambient temperature and pressure, and allow the oxidation of amines without expensive ligands or additives. This study highlights the significant role counterions can play in controlling selectivity in catalytic aerobic oxidations. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Evaluation of a High Intensity Focused Ultrasound-Immobilized Trypsin Digestion and 18O-Labeling Method for Quantitative Proteomics

PubMed Central

López-Ferrer, Daniel; Hixson, Kim K.; Smallwood, Heather; Squier, Thomas C.; Petritis, Konstantinos; Smith, Richard D.

2009-01-01

A new method that uses immobilized trypsin concomitant with ultrasonic irradiation results in ultra-rapid digestion and thorough 18O labeling for quantitative protein comparisons. The reproducible and highly efficient method provided effective digestions in <1 min with a minimized amount of enzyme required compared to traditional methods. This method was demonstrated for digestion of both simple and complex protein mixtures, including bovine serum albumin, a global proteome extract from the bacteria Shewanella oneidensis, and mouse plasma, as well as 18O labeling of such complex protein mixtures, which validated the application of this method for differential proteomic measurements. This approach is simple, reproducible, cost effective, rapid, and thus well-suited for automation. PMID:19555078

Cellufine sulfate column chromatography as a simple, rapid, and effective method to purify dengue virus.

PubMed

Kanlaya, Rattiyaporn; Thongboonkerd, Visith

2016-08-01

Conventional method to purify/concentrate dengue virus (DENV) is time-consuming with low virus recovery yield. Herein, we applied cellufine sulfate column chromatography to purify/concentrate DENV based on the mimicry between heparan sulfate and DENV envelope protein. Comparative analysis demonstrated that this new method offered higher purity (as determined by less contamination of bovine serum albumin) and recovery yield (as determined by greater infectivity). Moreover, overall duration used for cellufine sulfate column chromatography to purify/concentrate DENV was approximately 1/20 of that of conventional method. Therefore, cellufine sulfate column chromatography serves as a simple, rapid, and effective alternative method for DENV purification/concentration. Copyright © 2016 Elsevier B.V. All rights reserved.

A New Rapid and Sensitive Stability-Indicating UPLC Assay Method for Tolterodine Tartrate: Application in Pharmaceuticals, Human Plasma and Urine Samples.

PubMed

Yanamandra, Ramesh; Vadla, Chandra Sekhar; Puppala, Umamaheshwar; Patro, Balaram; Murthy, Yellajyosula L N; Ramaiah, Parimi Atchuta

2012-01-01

A new rapid, simple, sensitive, selective and accurate reversed-phase stability-indicating Ultra Performance Liquid Chromatography (RP-UPLC) technique was developed for the assay of Tolterodine Tartrate in pharmaceutical dosage form, human plasma and urine samples. The developed UPLC method is superior in technology to conventional HPLC with respect to speed, solvent consumption, resolution and cost of analysis. Chromatographic run time was 6 min in reversed-phase mode and ultraviolet detection was carried out at 220 nm for quantification. Efficient separation was achieved for all the degradants of Tolterodine Tartrate on BEH C18 sub-2-μm Acquity UPLC column using Trifluoroacetic acid and acetonitrile as organic solvent in a linear gradient program. The active pharmaceutical ingredient was extracted from tablet dosage form using a mixture of acetonitrile and water as diluent. The calibration graphs were linear and the method showed excellent recoveries for bulk and tablet dosage form. The test solution was found to be stable for 40 days when stored in the refrigerator between 2 and 8 °C. The developed UPLC method was validated and meets the requirements delineated by the International Conference on Harmonization (ICH) guidelines with respect to linearity, accuracy, precision, specificity and robustness. The intra-day and inter-day variation was found be less than 1%. The method was reproducible and selective for the estimation of Tolterodine Tartrate. Because the method could effectively separate the drug from its degradation products, it can be employed as a stability-indicating one.

A New Rapid and Sensitive Stability-Indicating UPLC Assay Method for Tolterodine Tartrate: Application in Pharmaceuticals, Human Plasma and Urine Samples

PubMed Central

Yanamandra, Ramesh; Vadla, Chandra Sekhar; Puppala, Umamaheshwar; Patro, Balaram; Murthy, Yellajyosula. L. N.; Ramaiah, Parimi Atchuta

2012-01-01

A new rapid, simple, sensitive, selective and accurate reversed-phase stability-indicating Ultra Performance Liquid Chromatography (RP-UPLC) technique was developed for the assay of Tolterodine Tartrate in pharmaceutical dosage form, human plasma and urine samples. The developed UPLC method is superior in technology to conventional HPLC with respect to speed, solvent consumption, resolution and cost of analysis. Chromatographic run time was 6 min in reversed-phase mode and ultraviolet detection was carried out at 220 nm for quantification. Efficient separation was achieved for all the degradants of Tolterodine Tartrate on BEH C18 sub-2-μm Acquity UPLC column using Trifluoroacetic acid and acetonitrile as organic solvent in a linear gradient program. The active pharmaceutical ingredient was extracted from tablet dosage form using a mixture of acetonitrile and water as diluent. The calibration graphs were linear and the method showed excellent recoveries for bulk and tablet dosage form. The test solution was found to be stable for 40 days when stored in the refrigerator between 2 and 8 °C. The developed UPLC method was validated and meets the requirements delineated by the International Conference on Harmonization (ICH) guidelines with respect to linearity, accuracy, precision, specificity and robustness. The intra-day and inter-day variation was found be less than 1%. The method was reproducible and selective for the estimation of Tolterodine Tartrate. Because the method could effectively separate the drug from its degradation products, it can be employed as a stability-indicating one. PMID:22396907

The endomembrane requirement for cell surface repair

NASA Technical Reports Server (NTRS)

McNeil, Paul L.; Miyake, Katsuya; Vogel, Steven S.

2003-01-01

The capacity to reseal a plasma membrane disruption rapidly is required for cell survival in many physiological environments. Intracellular membrane (endomembrane) is thought to play a central role in the rapid resealing response. We here directly compare the resealing response of a cell that lacks endomembrane, the red blood cell, with that of several nucleated cells possessing an abundant endomembrane compartment. RBC membrane disruptions inflicted by a mode-locked Ti:sapphire laser, even those initially smaller than hemoglobin, failed to reseal rapidly. By contrast, much larger laser-induced disruptions made in sea urchin eggs, fibroblasts, and neurons exhibited rapid, Ca(2+)-dependent resealing. We conclude that rapid resealing is not mediated by simple physiochemical mechanisms; endomembrane is required.

Perspectives on the rapid eye movement sleep switch in rapid eye movement sleep behavior disorder.

PubMed

Ramaligam, Vetrivelan; Chen, Michael C; Saper, Clifford B; Lu, Jun

2013-08-01

Rapid eye movement (REM) sleep in mammals is associated with wakelike cortical and hippocampal activation and concurrent postural muscle atonia. Research during the past 5 decades has revealed the details of the neural circuitry regulating REM sleep and muscle atonia during this state. REM-active glutamatergic neurons in the sublaterodorsal nucleus (SLD) of the dorsal pons are critical for generation for REM sleep atonia. Descending projections from SLD glutamatergic neurons activate inhibitory premotor neurons in the ventromedial medulla (VMM) and in the spinal cord to antagonize the glutamatergic supraspinal inputs on the motor neurons during REM sleep. REM sleep behavior disorder (RBD) consists of simple behaviors (i.e., twitching, jerking) and complex behaviors (i.e., defensive behavior, talking). Animal research has lead to the hypothesis that complex behaviors in RBD are due to SLD pathology, while simple behaviors of RBD may be due to less severe SLD pathology or dysfunction of the VMM, ventral pons, or spinal cord. Copyright © 2013 Elsevier B.V. All rights reserved.

Saccade selection when reward probability is dynamically manipulated using Markov chains

PubMed Central

Lovejoy, Lee P.; Krauzlis, Richard J.

2012-01-01

Markov chains (stochastic processes where probabilities are assigned based on the previous outcome) are commonly used to examine the transitions between behavioral states, such as those that occur during foraging or social interactions. However, relatively little is known about how well primates can incorporate knowledge about Markov chains into their behavior. Saccadic eye movements are an example of a simple behavior influenced by information about probability, and thus are good candidates for testing whether subjects can learn Markov chains. In addition, when investigating the influence of probability on saccade target selection, the use of Markov chains could provide an alternative method that avoids confounds present in other task designs. To investigate these possibilities, we evaluated human behavior on a task in which stimulus reward probabilities were assigned using a Markov chain. On each trial, the subject selected one of four identical stimuli by saccade; after selection, feedback indicated the rewarded stimulus. Each session consisted of 200–600 trials, and on some sessions, the reward magnitude varied. On sessions with a uniform reward, subjects (n = 6) learned to select stimuli at a frequency close to reward probability, which is similar to human behavior on matching or probability classification tasks. When informed that a Markov chain assigned reward probabilities, subjects (n = 3) learned to select the greatest reward probability more often, bringing them close to behavior that maximizes reward. On sessions where reward magnitude varied across stimuli, subjects (n = 6) demonstrated preferences for both greater reward probability and greater reward magnitude, resulting in a preference for greater expected value (the product of reward probability and magnitude). These results demonstrate that Markov chains can be used to dynamically assign probabilities that are rapidly exploited by human subjects during saccade target selection. PMID:18330552

Saccade selection when reward probability is dynamically manipulated using Markov chains.

PubMed

Nummela, Samuel U; Lovejoy, Lee P; Krauzlis, Richard J

2008-05-01

Markov chains (stochastic processes where probabilities are assigned based on the previous outcome) are commonly used to examine the transitions between behavioral states, such as those that occur during foraging or social interactions. However, relatively little is known about how well primates can incorporate knowledge about Markov chains into their behavior. Saccadic eye movements are an example of a simple behavior influenced by information about probability, and thus are good candidates for testing whether subjects can learn Markov chains. In addition, when investigating the influence of probability on saccade target selection, the use of Markov chains could provide an alternative method that avoids confounds present in other task designs. To investigate these possibilities, we evaluated human behavior on a task in which stimulus reward probabilities were assigned using a Markov chain. On each trial, the subject selected one of four identical stimuli by saccade; after selection, feedback indicated the rewarded stimulus. Each session consisted of 200-600 trials, and on some sessions, the reward magnitude varied. On sessions with a uniform reward, subjects (n = 6) learned to select stimuli at a frequency close to reward probability, which is similar to human behavior on matching or probability classification tasks. When informed that a Markov chain assigned reward probabilities, subjects (n = 3) learned to select the greatest reward probability more often, bringing them close to behavior that maximizes reward. On sessions where reward magnitude varied across stimuli, subjects (n = 6) demonstrated preferences for both greater reward probability and greater reward magnitude, resulting in a preference for greater expected value (the product of reward probability and magnitude). These results demonstrate that Markov chains can be used to dynamically assign probabilities that are rapidly exploited by human subjects during saccade target selection.

Rapid Discrimination of Gram-Positive and Gram-Negative Bacteria in Liquid Samples by Using NaOH-Sodium Dodecyl Sulfate Solution and Flow Cytometry

PubMed Central

Wada, Atsushi; Kono, Mari; Kawauchi, Sawako; Takagi, Yuri; Morikawa, Takashi; Funakoshi, Kunihiro

2012-01-01

Background For precise diagnosis of urinary tract infections (UTI), and selection of the appropriate prescriptions for their treatment, we explored a simple and rapid method of discriminating gram-positive and gram-negative bacteria in liquid samples. Methodology/Principal Findings We employed the NaOH-sodium dodecyl sulfate (SDS) solution conventionally used for plasmid extraction from Escherichia coli and the automated urine particle analyzer UF-1000i (Sysmex Corporation) for our novel method. The NaOH-SDS solution was used to determine differences in the cell wall structures between gram-positive and gram-negative bacteria, since the tolerance to such chemicals reflects the thickness and structural differences of bacterial cell walls. The UF-1000i instrument was used as a quantitative bacterial counter. We found that gram-negative bacteria, including E. coli, in liquid culture could easily be lysed by direct addition of equal volumes of NaOH-SDS solution. In contrast, Enterococcus faecalis, which is a gram-positive bacterium, could not be completely lysed by the solution. We then optimized the reaction time of the NaOH-SDS treatment at room temperature by using 3 gram-positive and 4 gram-negative bacterial strains and determined that the optimum reaction time was 5 min. Finally, in order to evaluate the generalizability of this method, we treated 8 gram-positive strains and 8 gram-negative strains, or 4 gram-positive and 4 gram-negative strains incubated in voluntary urine from healthy volunteers in the same way and demonstrated that all the gram-positive bacteria were discriminated quantitatively from gram negative bacteria using this method. Conclusions/Significance Using our new method, we could easily discriminate gram-positive and gram-negative bacteria in liquid culture media within 10 min. This simple and rapid method may be useful for determining the treatment course of patients with UTIs, especially for those without a prior history of UTIs. The method may be easily applied in order to obtain additional information for clinical prescriptions from bacteriuria. PMID:23077549

SMS messages increase adherence to rapid diagnostic test results among malaria patients: results from a pilot study in Nigeria.

PubMed

Modrek, Sepideh; Schatzkin, Eric; De La Cruz, Anna; Isiguzo, Chinwoke; Nwokolo, Ernest; Anyanti, Jennifer; Ujuju, Chinazo; Montagu, Dominic; Liu, Jenny

2014-02-25

The World Health Organization now recommends parasitological confirmation for malaria case management. Rapid diagnostic tests (RDTs) for malaria are an accurate and simple diagnostic to confirm parasite presence in blood. However, where they have been deployed, adherence to RDT results has been poor, especially when the test result is negative. Few studies have examined adherence to RDTs distributed or purchased through the private sector. The Rapid Examination of Malaria and Evaluation of Diagnostic Information (REMEDI) study assessed the acceptability of and adherence to RDT results for patients seeking care from private sector drug retailers in two cities in Oyo State in south-west Nigeria. In total, 465 adult participants were enrolled upon exit from a participating drug shop having purchased anti-malaria drugs for themselves. Participants were given a free RDT and the appropriate treatment advice based on their RDT result. Short Message Service (SMS) text messages reiterating the treatment advice were sent to a randomly selected half of the participants one day after being tested. Participants were contacted via phone four days after the RDT was conducted to assess adherence to the RDT information and treatment advice. Adherence to RDT results was 14.3 percentage points (P-val <0.001) higher in the treatment group who were sent the SMS. The higher adherence in the treatment group was robust to several specification tests and the estimated difference in adherence ranged from 9.7 to 16.1 percentage points. Further, the higher adherence to the treatment advice was specific to the treatment advice for anti-malarial drugs and not other drugs purchased to treat malaria symptoms in the RDT-negative participants who bought both anti-malarial and symptom drugs. There was no difference in adherence for the RDT-positive participants who were sent the SMS. SMS text messages substantially increased adherence to RDT results for patients seeking care for malaria from privately owned drug retailers in Nigeria and may be a simple and cost-effective means for boosting adherence to RDT results if and when RDTs are introduced as a commercial retail product.

A novel strategy for rapid detection of NT-proBNP

NASA Astrophysics Data System (ADS)

Cui, Qiyao; Sun, Honghao; Zhu, Hui

2017-09-01

In order to establish a simple, rapid, sensitive, and specific quantitative assay to detect the biomarkers of heart failure, in this study, biotin-streptavidin technology was employed with fluorescence immunochromatographic assay to detect the concentration of the biomarkers in serum, and this method was applied to detect NT-proBNP, which is valuable for diagnostic evaluation of heart failure.

Development of an immunochromatographic strip test for rapid detection of melamine in raw milk, milk products, and animal feed

USDA-ARS?s Scientific Manuscript database

A simple, rapid and sensitive immunogold chromatographic strip test based on a monoclonal antibody was developed for the detection of melamine (MEL) residues in raw milk, milk products and animal feed. The limit of detection was estimated to be 0.05 µg/mL in raw milk, since the detection test line ...

A centrifugal method for the evaluation of polymer membranes for reverse osmosis

NASA Technical Reports Server (NTRS)

Hollahan, J. R.; Wydeven, T.; Mccullough, R. P.

1973-01-01

A rapid and simple method employing the laboratory centrifuge shows promise for evaluation of membrane performance during reverse osmosis. Results are presented for cellulose acetate membranes for rejection of salt and urea dissolved solids. Implications of the study are to rapid screening of membrane performance, use in laboratories with limited facilities, and possible space waste water purification.

A rapid molecular diagnosis of cutaneous leishmaniasis by colorimetric malachite green-loop-mediated isothermal amplification (LAMP) combined with an FTA card as a direct sampling tool.

PubMed

Nzelu, Chukwunonso O; Cáceres, Abraham G; Guerrero-Quincho, Silvia; Tineo-Villafuerte, Edwin; Rodriquez-Delfin, Luis; Mimori, Tatsuyuki; Uezato, Hiroshi; Katakura, Ken; Gomez, Eduardo A; Guevara, Angel G; Hashiguchi, Yoshihisa; Kato, Hirotomo

2016-01-01

Leishmaniasis remains one of the world's most neglected diseases, and early detection of the infectious agent, especially in developing countries, will require a simple and rapid test. In this study, we established a quick, one-step, single-tube, highly sensitive loop-mediated isothermal amplification (LAMP) assay for rapid detection of Leishmania DNA from tissue materials spotted on an FTA card. An FTA-LAMP with pre-added malachite green was performed at 64°C for 60min using a heating block and/or water bath and DNA amplification was detected immediately after incubation. The LAMP assay had high detection sensitivity down to a level of 0.01 parasites per μl. The field- and clinic-applicability of the colorimetric FTA-LAMP assay was demonstrated with 122 clinical samples collected from patients suspected of having cutaneous leishmaniasis in Peru, from which 71 positives were detected. The LAMP assay in combination with an FTA card described here is rapid and sensitive, as well as simple to perform, and has great potential usefulness for diagnosis and surveillance of leishmaniasis in endemic areas. Copyright © 2015 Elsevier B.V. All rights reserved.

Rapid Characterization of Microalgae and Microalgae Mixtures Using Matrix-Assisted Laser Desorption Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS)

PubMed Central

Barbano, Duane; Diaz, Regina; Zhang, Lin; Sandrin, Todd; Gerken, Henri; Dempster, Thomas

2015-01-01

Current molecular methods to characterize microalgae are time-intensive and expensive. Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) may represent a rapid and economical alternative approach. The objectives of this study were to determine whether MALDI-TOF MS can be used to: 1) differentiate microalgae at the species and strain levels and 2) characterize simple microalgal mixtures. A common protein extraction sample preparation method was used to facilitate rapid mass spectrometry-based analysis of 31 microalgae. Each yielded spectra containing between 6 and 56 peaks in the m/z 2,000 to 20,000 range. The taxonomic resolution of this approach appeared higher than that of 18S rDNA sequence analysis. For example, two strains of Scenedesmus acutus differed only by two 18S rDNA nucleotides, but yielded distinct MALDI-TOF mass spectra. Mixtures of two and three microalgae yielded relatively complex spectra that contained peaks associated with members of each mixture. Interestingly, though, mixture-specific peaks were observed at m/z 11,048 and 11,230. Our results suggest that MALDI-TOF MS affords rapid characterization of individual microalgae and simple microalgal mixtures. PMID:26271045

Optical resonance-enhanced absorption-based near-field immunochip biosensor for allergen detection.

PubMed

Maier, Irene; Morgan, Michael R A; Lindner, Wolfgang; Pittner, Fritz

2008-04-15

An optical immunochip biosensor has been developed as a rapid method for allergen detection in complex food matrixes, and its application evaluated for the detection of the egg white allergens, ovalbumin and ovomucoid. The optical near-field phenomenon underlying the basic principle of the sensor design is called resonance-enhanced absorption (REA), which utilizes gold nanoparticles (Au NPs) as signal transducers in a highly sensitive interferometric setup. Using this approach, a novel, simple, and rapid colorimetric solid-phase immunoassay on a planar chip substrate was realized in direct and sandwich assay formats, with a detection system that does not require any instrumentation for readout. Semiquantitative immunochemical responses are directly visible to the naked eye of the analyst. The biosensor shows concentration-dependent color development by capturing antibody-functionalized Au NPs on allergen-coated chips and has a detection limit of 1 ng/mL. To establish a rapid method, we took advantage of the physicochemical microenvironment of the Au NP-antibody bioconjugate to be bound directly over an interacting poly(styrene-methyl methacrylate) interlayer by an immobilized antigen. In the direct assay format, a coating time with allergen of only 5 min under "soft" nondenaturing conditions was sufficient for accurate reproducibility and sensitivity. In conclusion, the REA-based immunochip sensor is easy to fabricate, is reproducible and selective in its performance, has minimal technical requirements, and will enable high-throughput screening of affinity binding interactions in technological and medical applications.

Rapid determination of underivatized pyroglutamic acid, glutamic acid, glutamine and other relevant amino acids in fermentation media by LC-MS-MS.

PubMed

Qu, Jun; Chen, Wei; Luo, Guoan; Wang, Yiming; Xiao, Shengyuan; Ling, Zhihua; Chen, Guoqiang

2002-01-01

Determination of amino acids in a complex matrix without derivatization is advantageous, however, difficulties are found in both the detection and the separation of those compounds. In this study, a rapid and reliable LC-MS-MS method for the quantitation of underivatized amino acids in exocellular media was established. Injections were made directly after centrifugation of the samples, without further preparation. The separation of seven underivatized amino acids was achieved on a reversed-phase C18 column with pentadecafluorooctanoic acid as a volatile ion-pair reagent, and the specific detection of most amino acids was achieved by MS-MS of the specific transitions [M + H]+-->[M + H - 46]+. The calibration curves of all analytes were linear over the range of 1.0-1000 microg ml(-1) and the detection limits ranged from 0.1 to 5 ng ml(-1), with an injection volume of 20 microl. The inter-day and intra-day precisions ranged from 2.6 to 5.7% and 4.8 to 8.2%, respectively; the mean recoveries of the seven analytes were 81-104%, 91-107% and 93-101% respectively at the spiked level of 10, 40 and 200 microg ml(-1). A large number of fermentation samples were analysed using this method. The technique is simple, rapid, selective and sensitive, and shows potential for the high-throughput quantitation of amino acids from other biological matrices.

Using Depth Recovery in Humans

DTIC Science & Technology

1988-07-07

presence of oriented luminance discontinuities or "edges" in the image data (Marr & Poggio, i976; Dey, 1975; Nelson, 1975 & 1977; Marr, Palm & Poggio, 1978...primitives, namely computational expense, is rapidly diminishing as we continue to benefit from dramatic advances in signal processing hardware...dimensional weighting function of simple cells are well fitted by Gabor functions. Pollen & Ronner (1981) demonstrated that simple cells which are tuned to

Conventional laboratory methods for cyanotoxins.

PubMed

Lawton, Linda A; Edwards, C

2008-01-01

It is clear from the literature that numerous methods are available for most cyanotoxins, although many publications on monitoring data indicate that the favored approach is the use proven, robust methods for individual toxins. The most effective approach is the utilization of a robust rapid screen, where positive samples are followed up by qualitative and quantitative analysis to provide the essential decision making data needed for successful management strategies (Fig. 2). Currently, rapid screens are available for microcystins, saxitoxins and anatoxin-a(s), whilst optimisation and validation is needed, many publications report good correlation with the mouse bioassay and HPLC. There is an urgent need for rapid, simple, and inexpensive assays for cylindrospermopsins, anatoxin-a and BMAA. Although methods exist for analysis of BMAA, the fact that a recent study showed 95% of cyanobacteria producing this, some at levels > 6,000 microg g(-1) dry wt, is of concern and rapid screening followed by robust analysis needed. An ideal approach would be a single method capable of extracting and detecting all cyanotoxins. Several publications describe such approaches using LC-MS, but as expected from a group of compounds with diverse chemistry, there are obvious limitations in recoveries during sample processing, chromatographic performance and sensitivity (Dahlmann et al. 2003, Dell'Aversano et al. 2004, Pietsch et al. 2001). Selection of methods must be based on the application requirements, equipment available and cost. For many organisations it may be more cost effective to out-source the occasional analysis. However, as the incidence of blooms appears to be increasing, the need for more rigorous monitoring is needed, sensible investment is needed to meet recommended guidelines. Most of the methods discussed in this paper are suitable for achieving this goal, although clean-up and concentration is usually necessary for physicochemical methods.

Input Control Processes in Rapid Serial Visual Presentations: Target Selection and Distractor Inhibition

ERIC Educational Resources Information Center

Olivers, Christian N. L.; Watson, Derrick G.

2006-01-01

The attentional blink refers to the finding that the 2nd of 2 targets embedded in a stream of rapidly presented distractors is often missed. Whereas most theories of the attentional blink focus on limited-capacity processes that occur after target selection, the present work investigates the selection process itself. Identifying a target letter…

Simultaneous spectrophotometric determination of paracetamol and salicylamide in human serum and pharmaceutical formulations by a differential kinetic method.

PubMed

Zarei, Ali Reza; Afkhami, Abbas; Sarlak, Nahid

2005-01-01

A rapid, simple, and sensitive differential kinetic method is presented for the determinations of acetaminophen (also known as paracetamol) and salicylamide. The method is based on their oxidation reaction by Fe3+ ion in the presence of 1, 10-phenanthroline as indicator. The reactions can be monitored spectrophotometrically by measuring the increase in the absorbance of the solution at 510 nm. Two times were selected one in which only paracetamol is oxidized by Fe3+ ion and the other in which both drugs are oxidized by Fe3+ ion. The data were evaluated by the proportional equations method. The method allowed the simultaneous determination of paracetamol and salicylamide at concentrations between 0.5-20 and 1-40 microg/mL with relative standard deviations of 3.47 and 2.58%, respectively. The method was applied to the simultaneous determination of paracetamol and salicylamide in human serum and pharmaceutical formulations.

Silica/graphene oxide nanocomposites: Potential adsorbents for solid phase extraction of trace aflatoxins in cereal crops coupled with high performance liquid chromatography.

PubMed

Yu, Li; Ma, Fei; Ding, Xiaoxia; Wang, Hengling; Li, Peiwu

2018-04-15

Graphene oxide wrapped silica nanocomposites were synthesized and selected as solid phase extraction adsorbents for high performance liquid chromatography analysis of aflatoxins. The major parameters affecting extraction efficiency were optimized, including the amount of adsorbents, extraction time and desorption conditions. The limit of detections and the limit of quantifications were from 0.1 to 0.3 µg/kg and from 0.3 to 1.0 µg/kg, respectively. The recoveries of aflatoxins in the spiked maize and rice samples were in the range of 76.8-104.7% and 81.1-106.9%, respectively, and with the RSDs less than 12.4%. The proposed method was proven to be simple, rapid and reliable for routine analysis of aflatoxins in crops. Copyright © 2017 Elsevier Ltd. All rights reserved.

Simultaneous Determination of Eight Hypotensive Drugs of Various Chemical Groups in Pharmaceutical Preparations by HPLC-DAD.

PubMed

Stolarczyk, Mariusz; Hubicka, Urszula; Żuromska-Witek, Barbara; Krzek, Jan

2015-01-01

A new sensitive, simple, rapid, and precise HPLC method with diode array detection has been developed for separation and simultaneous determination of hydrochlorothiazide, furosemide, torasemide, losartane, quinapril, valsartan, spironolactone, and canrenone in combined pharmaceutical dosage forms. The chromatographic analysis of the tested drugs was performed on an ACE C18, 100 Å, 250×4.6 mm, 5 μm particle size column with 0.0.05 M phosphate buffer (pH=3.00)-acetonitrile-methanol (30+20+50 v/v/v) mobile phase at a flow rate of 1.0 mL/min. The column was thermostatted at 25°C. UV detection was performed at 230 nm. Analysis time was 10 min. The elaborated method meets the acceptance criteria for specificity, linearity, sensitivity, accuracy, and precision. The proposed method was successfully applied for the determination of the studied drugs in the selected combined dosage forms.

Lab-on-chip components for molecular detection

NASA Astrophysics Data System (ADS)

Adam, Tijjani; Dhahi, Th S.; Mohammed, Mohammed; Hashim, U.; Noriman, N. Z.; Dahham, Omar S.

2017-09-01

We successfully fabricated Lab on chip components and integrated for possible use in biomedical application. The sensor was fabricated by using conventional photolithography method integrated with PDMS micro channels for smooth delivery of sample to the sensing domain. The sensor was silanized and aminated with 3-Aminopropyl triethoxysilane (APTES) to functionalize the surface with biomolecules and create molecular binding chemistry. The resulting Si-O-Si- components were functionalized with oligonucleotides probe of HPV, which interacted with the single stranded HPV DNA target to create a field across on the device. The fabrication, immobilization and hybridization processes were characterized with current voltage (I-V) characterization (KEITHLEY, 6487). The sensor show selectivity for the HPV DNA target in a linear range from concentration 0.1 nM to 1 µM. This strategy presented a simple, rapid and sensitive platform for HPV detection and would become a powerful tool for pathogenic microorganisms screening in clinical diagnosis.

Carbon Nanomaterial Based Biosensors for Non-Invasive Detection of Cancer and Disease Biomarkers for Clinical Diagnosis

PubMed Central

Tung, Thanh Tran

2017-01-01

The early diagnosis of diseases, e.g., Parkinson’s and Alzheimer’s disease, diabetes, and various types of cancer, and monitoring the response of patients to the therapy plays a critical role in clinical treatment; therefore, there is an intensive research for the determination of many clinical analytes. In order to achieve point-of-care sensing in clinical practice, sensitive, selective, cost-effective, simple, reliable, and rapid analytical methods are required. Biosensors have become essential tools in biomarker sensing, in which electrode material and architecture play critical roles in achieving sensitive and stable detection. Carbon nanomaterials in the form of particle/dots, tube/wires, and sheets have recently become indispensable elements of biosensor platforms due to their excellent mechanical, electronic, and optical properties. This review summarizes developments in this lucrative field by presenting major biosensor types and variability of sensor platforms in biomedical applications. PMID:28825646

Determination of ametryn herbicide by bioassay and gas chromatography-mass spectrometry in analysis of residues in drinking water.

PubMed

Queiroz, R H; Lanchote, V L; Bonato, P S; Tozato, E; de Carvalho, D; Gomes, M A; Cerdeira, A L

1999-06-01

A simple, rapid and quantitative bioassay method was compared to a gas chromatography/mass spectrometry (GC/MS) procedure for the analysis of ametryn in surface and groundwater. This method was based on the activity of ametryn in inhibiting the growth of the primary root and shoot of germinating letuce, Lactuca sativa L. seed. The procedure was sensitive to 0.01 microgram/l and was applicable from this concentration up to 0.6 microgram/l. Initial surface sterilization of the seed, selection of pregerminated seed of certain root lengths and special equipment are not necessary. So, we concluded that the sensitivity of the bioassay method is compatible with the chromatographic method (GC-MS). However, the study of the correlation between methods suggests that the bioassay should be used only as a screening technique for the evaluation of ametryn residues in water.

Spatiotemporal polarization modulation microscopy with a microretarder array

NASA Astrophysics Data System (ADS)

Ding, Changqin; Ulcickas, James R. W.; Simpson, Garth J.

2018-02-01

A patterned microretarder array positioned in the rear conjugate plane of a microscope enables rapid polarizationdependent nonlinear optical microscopy. The pattern introduced to the array results in periodic modulation of the polarization-state of the incident light as a function of position within the field of view with no moving parts or active control. Introduction of a single stationary optical element and a fixed polarizer into the beam of a nonlinear optical microscope enabled nonlinear optical tensor recovery, which informs on local structure and orientation. Excellent agreement was observed between the measured and predicted second harmonic generation (SHG) of z-cut quartz, selected as a test system with well-established nonlinear optical properties. Subsequent studies of spatially varying samples further support the general applicability of this relatively simple strategy for detailed polarization analysis in both conventional and nonlinear optical imaging of structurally diverse samples.

An Improved Fast Self-Calibration Method for Hybrid Inertial Navigation System under Stationary Condition

PubMed Central

Liu, Bingqi; Wei, Shihui; Su, Guohua; Wang, Jiping; Lu, Jiazhen

2018-01-01

The navigation accuracy of the inertial navigation system (INS) can be greatly improved when the inertial measurement unit (IMU) is effectively calibrated and compensated, such as gyro drifts and accelerometer biases. To reduce the requirement for turntable precision in the classical calibration method, a continuous dynamic self-calibration method based on a three-axis rotating frame for the hybrid inertial navigation system is presented. First, by selecting a suitable IMU frame, the error models of accelerometers and gyros are established. Then, by taking the navigation errors during rolling as the observations, the overall twenty-one error parameters of hybrid inertial navigation system (HINS) are identified based on the calculation of the intermediate parameter. The actual experiment verifies that the method can identify all error parameters of HINS and this method has equivalent accuracy to the classical calibration on a high-precision turntable. In addition, this method is rapid, simple and feasible. PMID:29695041

An Improved Fast Self-Calibration Method for Hybrid Inertial Navigation System under Stationary Condition.

PubMed

Liu, Bingqi; Wei, Shihui; Su, Guohua; Wang, Jiping; Lu, Jiazhen

2018-04-24

The navigation accuracy of the inertial navigation system (INS) can be greatly improved when the inertial measurement unit (IMU) is effectively calibrated and compensated, such as gyro drifts and accelerometer biases. To reduce the requirement for turntable precision in the classical calibration method, a continuous dynamic self-calibration method based on a three-axis rotating frame for the hybrid inertial navigation system is presented. First, by selecting a suitable IMU frame, the error models of accelerometers and gyros are established. Then, by taking the navigation errors during rolling as the observations, the overall twenty-one error parameters of hybrid inertial navigation system (HINS) are identified based on the calculation of the intermediate parameter. The actual experiment verifies that the method can identify all error parameters of HINS and this method has equivalent accuracy to the classical calibration on a high-precision turntable. In addition, this method is rapid, simple and feasible.

Direct α-C-H bond functionalization of unprotected cyclic amines

NASA Astrophysics Data System (ADS)

Chen, Weijie; Ma, Longle; Paul, Anirudra; Seidel, Daniel

2018-02-01

Cyclic amines are ubiquitous core structures of bioactive natural products and pharmaceutical drugs. Although the site-selective abstraction of C-H bonds is an attractive strategy for preparing valuable functionalized amines from their readily available parent heterocycles, this approach has largely been limited to substrates that require protection of the amine nitrogen atom. In addition, most methods rely on transition metals and are incompatible with the presence of amine N-H bonds. Here we introduce a protecting-group-free approach for the α-functionalization of cyclic secondary amines. An operationally simple one-pot procedure generates products via a process that involves intermolecular hydride transfer to generate an imine intermediate that is subsequently captured by a nucleophile, such as an alkyl or aryl lithium compound. Reactions are regioselective and stereospecific and enable the rapid preparation of bioactive amines, as exemplified by the facile synthesis of anabasine and (-)-solenopsin A.

"Molecular beacon"-hosted thioflavin T: Applications for label-free fluorescent detection of iodide and logic operations.

PubMed

Li, Yan-Yun; Jiang, Xiao-Qin; Lu, Ling-Fei; Zhang, Min; Shi, Guoyue

2016-04-01

In this work, we presented a simple, label-free and rapid-responsive fluorescence assay for iodide (I(-)) detection based on "molecular beacon (MB)"-hosted thioflavin T (ThT), achieving a limit of detection as low as 158 nM. The proposed method exhibited very good selectivity to I(-) ions over other anions interference due to the strong binding force between I(-) ions with Hg(2+). Upon the addition of I(-) ions, it would capture Hg(2+) from a T-Hg(2+)-T complex belonging to the MB-like DNA hairpin structure, which eventually quenched the initial fluorescence as output. In addition, it was successfully applied for operation of an integrated DNA logic gate system and to the determination of I(-) in real samples such as human urine. Copyright © 2016 Elsevier B.V. All rights reserved.

Wide-field depth-sectioning fluorescence microscopy using projector-generated patterned illumination

NASA Astrophysics Data System (ADS)

Delica, Serafin; Mar Blanca, Carlo

2007-10-01

We present a simple and cost-effective wide-field, depth-sectioning, fluorescence microscope utilizing a commercial multimedia projector to generate excitation patterns on the sample. Highly resolved optical sections of fluorescent pollen grains at 1.9 μm axial resolution are constructed using the structured illumination technique. This requires grid excitation patterns to be scanned across the sample, which is straightforwardly implemented by creating slideshows of gratings at different phases, projecting them onto the sample, and synchronizing camera acquisition with slide transition. In addition to rapid dynamic pattern generation, the projector provides high illumination power and spectral excitation selectivity. We exploit these properties by imaging mouse neural cells in cultures multistained with Alexa 488 and Cy3. The spectral and structural neural information is effectively resolved in three dimensions. The flexibility and commercial availability of this light source is envisioned to open multidimensional imaging to a broader user base.

[Monolithic column-gold composite substrate preparation and application to SERS detection of pigment].

PubMed

Xie, Yun-Fei; Li, Yan; Yu, Hui; Qian, He; Yao, Wei-Rong

2014-03-01

In the present study, we developed a novel SERS substrate with the porous monolith material combined with classic gold nanoparticles, and erythrosine as the research object, by adjusting the different experimental conditions for optimal SERS enhancements, including system pH and mixing time, and ultimately selected the optimum pH value 5.06 and mixing time 25 min. Compared with the traditional gold plastic substrate enhancement effect, the experimental conditions were applied to the monolith substrate SERS detection of dye erythrosine, different concentrations of samples were used for erythrosine SERS detection, and the detection limit reached 0.1 g x mL(-1). The method uses the payload of gold nanoparticles in mesoporous materials to effectively enhance the SERS signal. And this method has the advantages of simpleness and good stability, which provides a favorable theoretical basis for the rapid prohibited colorings screening.

Molecular-channel driven actuator with considerations for multiple configurations and color switching.

PubMed

Mu, Jiuke; Wang, Gang; Yan, Hongping; Li, Huayu; Wang, Xuemin; Gao, Enlai; Hou, Chengyi; Pham, Anh Thi Cam; Wu, Lianjun; Zhang, Qinghong; Li, Yaogang; Xu, Zhiping; Guo, Yang; Reichmanis, Elsa; Wang, Hongzhi; Zhu, Meifang

2018-02-09

The ability to achieve simultaneous intrinsic deformation with fast response in commercially available materials that can safely contact skin continues to be an unresolved challenge for artificial actuating materials. Rather than using a microporous structure, here we show an ambient-driven actuator that takes advantage of inherent nanoscale molecular channels within a commercial perfluorosulfonic acid ionomer (PFSA) film, fabricated by simple solution processing to realize a rapid response, self-adaptive, and exceptionally stable actuation. Selective patterning of PFSA films on an inert soft substrate (polyethylene terephthalate film) facilitates the formation of a range of different geometries, including a 2D (two-dimensional) roll or 3D (three-dimensional) helical structure in response to vapor stimuli. Chemical modification of the surface allowed the development of a kirigami-inspired single-layer actuator for personal humidity and heat management through macroscale geometric design features, to afford a bilayer stimuli-responsive actuator with multicolor switching capability.

Collective evolution of cyanobacteria and cyanophages mediated by horizontal gene transfer

NASA Astrophysics Data System (ADS)

Shih, Hong-Yan; Rogers, Tim; Goldenfeld, Nigel

We describe a model for how antagonistic predator-prey coevolution can lead to mutualistic adaptation to an environment, as a result of horizontal gene transfer. Our model is a simple description of ecosystems such as marine cyanobacteria and their predator cyanophages, which carry photosynthesis genes. These genes evolve more rapidly in the virosphere than the bacterial pan-genome, and thus the bacterial population could potentially benefit from phage predation. By modeling both the barrier to predation and horizontal gene transfer, we study this balance between individual sacrifice and collective benefits. The outcome is an emergent mutualistic coevolution of improved photosynthesis capability, benefiting both bacteria and phage. This form of multi-level selection can contribute to niche stratification in the cyanobacteria-phage ecosystem. This work is supported in part by a cooperative agreement with NASA, Grant NNA13AA91A/A0018.

Assembling old tricks for new tasks: a neural model of instructional learning and control.

PubMed

Huang, Tsung-Ren; Hazy, Thomas E; Herd, Seth A; O'Reilly, Randall C

2013-06-01

We can learn from the wisdom of others to maximize success. However, it is unclear how humans take advice to flexibly adapt behavior. On the basis of data from neuroanatomy, neurophysiology, and neuroimaging, a biologically plausible model is developed to illustrate the neural mechanisms of learning from instructions. The model consists of two complementary learning pathways. The slow-learning parietal pathway carries out simple or habitual stimulus-response (S-R) mappings, whereas the fast-learning hippocampal pathway implements novel S-R rules. Specifically, the hippocampus can rapidly encode arbitrary S-R associations, and stimulus-cued responses are later recalled into the basal ganglia-gated pFC to bias response selection in the premotor and motor cortices. The interactions between the two model learning pathways explain how instructions can override habits and how automaticity can be achieved through motor consolidation.

Non-Instrumented Nucleic Acid Amplification (NINA) for Rapid Detection of Ralstonia solanacearum Race 3 Biovar 2

PubMed Central

Kubota, Ryo; LaBarre, Paul; Singleton, Jered; Beddoe, Andy; Weigl, Bernhard H.; Alvarez, Anne M.; Jenkins, Daniel M.

2014-01-01

We report on the use of a non-instrumented device for the implementation of a loop-mediated amplification (LAMP) based assay for the select-agent bacterial-wilt pathogen Ralstonia solanacearum race 3 biovar 2. Heat energy is generated within the device by the exothermic hydration of calcium oxide, and the reaction temperature is regulated by storing latent energy at the melting temperature of a renewable lipid-based engineered phase-change material. Endpoint detection of the LAMP reaction is achieved without opening the reaction tube by observing the fluorescence of an innovative FRET-based hybridization probe with a simple custom fluorometer. Non-instrumented devices could maintain reactions near the design temperature of 63°C for at least an hour. Using this approach DNA extracted from the pathogen could be detected at fewer than ten copies within a 25 μL reaction mix, illustrating the potential of these technologies for simple, powerful agricultural diagnostics in the field. Furthermore, the assay was just as reliable when implemented in a tropical environment at 31°C as it was when implemented in an air-conditioned lab maintained at 22°C, illustrating the potential value of the technology for field conditions in the tropics and subtropics. PMID:25485176

A simple and specific procedure to permeabilize the plasma membrane of Schizosaccharomyces pombe.

PubMed

Chardwiriyapreecha, Soracom; Hondo, Kana; Inada, Hiroko; Chahomchuen, Thippayarat; Sekito, Takayuki; Iwaki, Tomoko; Kakinuma, Yoshimi

2009-09-01

Cu(2+)-treatment is a useful technique in selectively permeabilizing the fungal plasma membrane. We describe herein a practical application with Schizosaccharomyces pombe. Incubation of cells with 0.5 mM CuCl(2) at 30 degrees C for 20 min induced efficient leakage of cytosolic constituents. The kinetic characteristics of the calcium and amino acid flux from Cu(2+)-treated S. pombe cells suggested that the Cu(2+) treatment permeabilized the plasma membrane without loss of vacuolar function. As a further application of the method, the amino acid contents of Cu(2+)-treated and untreated cells were also determined. The amino acid pool of Cu(2+)-treated wild-type cells was enriched in basic amino acids but not in acidic amino acids, as is characteristic of the vacuolar amino acid pool of fungi, including Saccharomyces cerevisiae and Neurosporra crassa. The amino acid pool of the S. pombe V-ATPase mutant vma1Delta was also successfully determined. We conclude that the vacuolar amino acid pool of S. pombe can be measured using Cu(2+)-treated cells. The method is simple, inexpensive, and rapid relative to the isolation of vacuolar vesicles, making it useful in estimating vacuolar pools and transport across the vacuolar membrane.

A simple and robust vector-based shRNA expression system used for RNA interference.

PubMed

Wang, Xue-jun; Li, Ying; Huang, Hai; Zhang, Xiu-juan; Xie, Pei-wen; Hu, Wei; Li, Dan-dan; Wang, Sheng-qi

2013-01-01

RNA interference (RNAi) mediated by small interfering RNAs (siRNAs) or short hairpin RNAs (shRNAs) has become a powerful genetic tool for conducting functional studies. Previously, vector-based shRNA-expression strategies capable of inducing RNAi in viable cells have been developed, however, these vector systems have some disadvantages, either because they were error-prone or cost prohibitive. In this report we described the development of a simple, robust shRNA expression system utilizing 1 long oligonucleotide or 2 short oligonucleotides for half the cost of conventional shRNA construction methods and with a >95% cloning success rate. The shRNA loop sequence and stem structure were also compared and carefully selected for better RNAi efficiency. Furthermore, an easier strategy was developed based on isocaudomers which permit rapid combination of the most efficient promoter-shRNA cassettes. Finally, using this method, the conservative target sites for hepatitis B virus (HBV) knockdown were systemically screened and HBV antigen expression shown to be successfully suppressed in the presence of connected multiple shRNAs both in vitro and in vivo. This novel design describes an inexpensive and effective way to clone and express single or multiple shRNAs from the same vector with the capacity for potent and effective silencing of target genes.

A stable and convenient protein electrophoresis titration device with bubble removing system.

PubMed

Zhang, Qiang; Fan, Liu-Yin; Li, Wen-Lin; Cong, Feng-Song; Zhong, Ran; Chen, Jing-Jing; He, Yu-Chen; Xiao, Hua; Cao, Cheng-Xi

2017-07-01

Moving reaction boundary titration (MRBT) has a potential application to immunoassay and protein content analysis with high selectivity. However, air bubbles often impair the accuracy of MRBT, and the leakage of electrolyte greatly decreases the safety and convenience of electrophoretic titration. Addressing these two issues a reliable MRBT device with modified electrolyte chamber of protein titration was designed. Multiphysics computer simulation was conducted for optimization according to two-phase flow. The single chamber was made of two perpendicular cylinders with different diameters. After placing electrophoretic tube, the resident air in the junction next to the gel could be eliminated by a simple fast electrolyte flow. Removing the electrophoretic tube automatically prevented electrolyte leakage at the junction due to the gravity-induced negative pressure within the chamber. Moreover, the numerical simulation and experiments showed that the improved MRBT device has following advantages: (i) easy and rapid setup of electrophoretic tube within 20 s; (ii) simple and quick bubble dissipates from the chamber of titration within 2 s; (iii) no electrolyte leakage from the two chambers: and (iv) accurate protein titration and safe instrumental operation. The developed technique and apparatus greatly improves the performance of the previous MRBT device, and providing a new route toward practical application. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Metal–Organic Framework Thin Film Coated Optical Fiber Sensors: A Novel Waveguide-Based Chemical Sensing Platform

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Ki-Joong; Lu, Ping; Culp, Jeffrey T.

Integration of optical fiber with sensitive thin films offers great potential for the realization of novel chemical sensing platforms. In this study, we present a simple design strategy and high performance of nanoporous metal–organic framework (MOF) based optical gas sensors, which enables detection of a wide range of concentrations of small molecules based upon extremely small differences in refractive indices as a function of analyte adsorption within the MOF framework. Thin and compact MOF films can be uniformly formed and tightly bound on the surface of etched optical fiber through a simple solution method which is critical for manufacturability ofmore » MOF-based sensor devices. The resulting sensors show high sensitivity/selectivity to CO 2 gas relative to other small gases (H 2, N 2, O 2, and CO) with rapid (< tens of seconds) response time and excellent reversibility, which can be well correlated to the physisorption of gases into a nanoporous MOF. We propose a refractive index based sensing mechanism for the MOF-integrated optical fiber platform which results in an amplification of inherent optical absorption present within the MOF-based sensing layer with increasing values of effective refractive index associated with adsorption of gases.« less

Metal–Organic Framework Thin Film Coated Optical Fiber Sensors: A Novel Waveguide-Based Chemical Sensing Platform

DOE PAGES

Kim, Ki-Joong; Lu, Ping; Culp, Jeffrey T.; ...

2018-01-18

Integration of optical fiber with sensitive thin films offers great potential for the realization of novel chemical sensing platforms. In this study, we present a simple design strategy and high performance of nanoporous metal–organic framework (MOF) based optical gas sensors, which enables detection of a wide range of concentrations of small molecules based upon extremely small differences in refractive indices as a function of analyte adsorption within the MOF framework. Thin and compact MOF films can be uniformly formed and tightly bound on the surface of etched optical fiber through a simple solution method which is critical for manufacturability ofmore » MOF-based sensor devices. The resulting sensors show high sensitivity/selectivity to CO 2 gas relative to other small gases (H 2, N 2, O 2, and CO) with rapid (< tens of seconds) response time and excellent reversibility, which can be well correlated to the physisorption of gases into a nanoporous MOF. We propose a refractive index based sensing mechanism for the MOF-integrated optical fiber platform which results in an amplification of inherent optical absorption present within the MOF-based sensing layer with increasing values of effective refractive index associated with adsorption of gases.« less

Development and validation of a stability-indicating high performance liquid chromatographic assay for benoxinate.

PubMed

Chorny, Michael; Levy, Daniel; Schumacher, Ilana; Lichaa, Chaim; Gruzman, Boris; Livshits, Oleg; Lomnicky, Yossi

2003-04-24

Benoxinate is a local anaesthetic used for ophthalmic applications. The aim of this study was to develop a rapid and simple stability-indicating method for the determination of benoxinate formulated for ophthalmic use, evaluate its long-term stability and identify its major degradation product. Benoxinate was eluted on a 10 microm Spherisorb phenyl column, 250 x 3.2 mm, with a mobile phase consisting of acetonitrile-buffer (pH 3.5) (35:65, v/v), pumped at 0.8 ml min(-1) flow rate. The buffer was composed of sodium dihydrogen phosphate (50 mM), sodium hydrogen sulfate (2.5 mM) and 1-heptanesulfonic acid sodium salt (5 mM). The analyte was quantified spectrophotometrically at 308 nm. The chromatograms of benoxinate formulations obtained by this method showed benoxinate (t = 4.5 min) well resolved from its degradation product (t = 2.3 min), which was separately identified by means of HPLC-MS as 4-amino-3-butoxybenzoic acid. The assay was demonstrated to have high accuracy, precision and linearity. The method was implemented in investigating the long-term stability of benoxinate 0.4% ophthalmic solutions. The method was found to be simple, quick and selective in determining benoxinate concentrations in fresh and aged preparations.

A simple statistical method for analyzing flood susceptibility with incorporating rainfall and impervious surface

NASA Astrophysics Data System (ADS)

Chiang, Shou-Hao; Chen, Chi-Farn

2016-04-01

Flood, as known as the most frequent natural hazard in Taiwan, has induced severe damages of residents and properties in urban areas. The flood risk is even more severe in Tainan since 1990s, with the significant urban development over recent decades. Previous studies have indicated that the characteristics and the vulnerability of flood are affected by the increase of impervious surface area (ISA) and the changing climate condition. Tainan City, in southern Taiwan is selected as the study area. This study uses logistic regression to functionalize the relationship between rainfall variables, ISA and historical flood events. Specifically, rainfall records from 2001 to 2014 were collected and mapped, and Landsat images of year 2001, 2004, 2007, 2010 and 2014 were used to generate the ISA with SVM (support vector machine) classifier. The result shows that rainfall variables and ISA are significantly correlated to the flood occurrence in Tainan City. With applying the logistic function, the likelihood of flood occurrence can be estimated and mapped over the study area. This study suggests the method is simple and feasible for rapid flood susceptibility mapping, when real-time rainfall observations can be available, and it has potential for future flood assessment, with incorporating climate change projections and urban growth prediction.

Direct ultrasensitive electrochemical biosensing of pathogenic DNA using homogeneous target-initiated transcription amplification

PubMed Central

Yan, Yurong; Ding, Shijia; Zhao, Dan; Yuan, Rui; Zhang, Yuhong; Cheng, Wei

2016-01-01

Sensitive and specific methodologies for detection of pathogenic gene at the point-of-care are still urgent demands in rapid diagnosis of infectious diseases. This work develops a simple and pragmatic electrochemical biosensing strategy for ultrasensitive and specific detection of pathogenic nucleic acids directly by integrating homogeneous target-initiated transcription amplification (HTITA) with interfacial sensing process in single analysis system. The homogeneous recognition and specific binding of target DNA with the designed hairpin probe triggered circular primer extension reaction to form DNA double-strands which contained T7 RNA polymerase promoter and served as templates for in vitro transcription amplification. The HTITA protocol resulted in numerous single-stranded RNA products which could synchronously hybridized with the detection probes and immobilized capture probes for enzyme-amplified electrochemical detection on the biosensor surface. The proposed electrochemical biosensing strategy showed very high sensitivity and selectivity for target DNA with a dynamic response range from 1 fM to 100 pM. Using salmonella as a model, the established strategy was successfully applied to directly detect invA gene from genomic DNA extract. This proposed strategy presented a simple, pragmatic platform toward ultrasensitive nucleic acids detection and would become a versatile and powerful tool for point-of-care pathogen identification. PMID:26729209

Direct ultrasensitive electrochemical biosensing of pathogenic DNA using homogeneous target-initiated transcription amplification

NASA Astrophysics Data System (ADS)

Yan, Yurong; Ding, Shijia; Zhao, Dan; Yuan, Rui; Zhang, Yuhong; Cheng, Wei

2016-01-01

Sensitive and specific methodologies for detection of pathogenic gene at the point-of-care are still urgent demands in rapid diagnosis of infectious diseases. This work develops a simple and pragmatic electrochemical biosensing strategy for ultrasensitive and specific detection of pathogenic nucleic acids directly by integrating homogeneous target-initiated transcription amplification (HTITA) with interfacial sensing process in single analysis system. The homogeneous recognition and specific binding of target DNA with the designed hairpin probe triggered circular primer extension reaction to form DNA double-strands which contained T7 RNA polymerase promoter and served as templates for in vitro transcription amplification. The HTITA protocol resulted in numerous single-stranded RNA products which could synchronously hybridized with the detection probes and immobilized capture probes for enzyme-amplified electrochemical detection on the biosensor surface. The proposed electrochemical biosensing strategy showed very high sensitivity and selectivity for target DNA with a dynamic response range from 1 fM to 100 pM. Using salmonella as a model, the established strategy was successfully applied to directly detect invA gene from genomic DNA extract. This proposed strategy presented a simple, pragmatic platform toward ultrasensitive nucleic acids detection and would become a versatile and powerful tool for point-of-care pathogen identification.

Direct ultrasensitive electrochemical biosensing of pathogenic DNA using homogeneous target-initiated transcription amplification.

PubMed

Yan, Yurong; Ding, Shijia; Zhao, Dan; Yuan, Rui; Zhang, Yuhong; Cheng, Wei

2016-01-05

Sensitive and specific methodologies for detection of pathogenic gene at the point-of-care are still urgent demands in rapid diagnosis of infectious diseases. This work develops a simple and pragmatic electrochemical biosensing strategy for ultrasensitive and specific detection of pathogenic nucleic acids directly by integrating homogeneous target-initiated transcription amplification (HTITA) with interfacial sensing process in single analysis system. The homogeneous recognition and specific binding of target DNA with the designed hairpin probe triggered circular primer extension reaction to form DNA double-strands which contained T7 RNA polymerase promoter and served as templates for in vitro transcription amplification. The HTITA protocol resulted in numerous single-stranded RNA products which could synchronously hybridized with the detection probes and immobilized capture probes for enzyme-amplified electrochemical detection on the biosensor surface. The proposed electrochemical biosensing strategy showed very high sensitivity and selectivity for target DNA with a dynamic response range from 1 fM to 100 pM. Using salmonella as a model, the established strategy was successfully applied to directly detect invA gene from genomic DNA extract. This proposed strategy presented a simple, pragmatic platform toward ultrasensitive nucleic acids detection and would become a versatile and powerful tool for point-of-care pathogen identification.

Variability and reduced performance of preschool- and early school-aged children on psychoacoustic tasks: What are the relevant factors?

NASA Astrophysics Data System (ADS)

Allen, Prudence

2003-04-01

Young children typically perform more poorly on psychoacoustic tasks than do adults, with large individual differences. When performance is averaged across children within age groups, the data suggest a gradual change in performance with increasing age. However, an examination of individual data suggests that the performance matures more rapidly, although at different times for different children. The mechanisms of development responsible for these changes are likely very complex, involving both sensory and cognitive processes. This paper will discuss some previously suggested mechanisms including attention and cue weighting, as well as possibilities suggested from more recent studies in which learning effects were examined. In one task, a simple frequency discrimination was required, while in another the listener was required to extract regularities in complex sequences of sounds that varied from trial to trial. Results suggested that the ability to select and consistently employ an effective listening strategy was especially important in the performance of the more complex task, while simple stimulus exposure and motivation contributed to the simpler task. These factors are important for understanding the perceptual development and for the subsequent application of psychoacoustic findings to clinical populations. [Work supported by the NSERC and the Canadian Language and Literacy Research Network.

Reductive electrografting of benzene (p-bisdiazonium hexafluorophosphate): a simple and effective protocol for creating diazonium-functionalized thin films.

PubMed

Marshall, Nicholas; Locklin, Jason

2011-11-01

In this Article, we describe a protocol for surface functionalization of benzenediazonium hexafluorophosphate monolayers by in situ electrochemical reduction of bis(benzenediazonium) hexafluorophosphate. Due to the considerable difference in potential between the first and second reduction of this species, it is possible to form a high density of surface-bound diazonium groups by use of a mild potential which selectively reduces only one diazonium group per ring. The resulting diazonium-containing monolayer reacts readily with solutions of electron-rich aromatic compounds. The reaction with ferrocene produces a dense (2.7 × 10(-10) mol/cm(2)) ferrocene-containing monolayer through a Gomberg-Bachmann type arylation. The resulting ferrocene group exhibits relatively rapid electron transfer to the electrode due to the conjugated linker layer as measured by alternating current voltammetry (ACV) and cyclic voltammetry. Aromatic systems with π-donor substitutents (N,N-dimethylaniline, N,N,N',N'-tetramethyldiaminobenzophenone, and hydroquinone) react through an azo-coupling to form monolayers linked to the surface through an azobenzene moiety. The redox properties of these electron-rich species tethered to the surface were observed and quantified using cyclic voltammetry. This simple and versatile functionalization procedure has a wide variety of potential applications in surface science and materials research.

Repeated divergent selection on pigmentation genes in a rapid finch radiation

PubMed Central

Campagna, Leonardo; Repenning, Márcio; Silveira, Luís Fábio; Fontana, Carla Suertegaray; Tubaro, Pablo L.; Lovette, Irby J.

2017-01-01

Instances of recent and rapid speciation are suitable for associating phenotypes with their causal genotypes, especially if gene flow homogenizes areas of the genome that are not under divergent selection. We study a rapid radiation of nine sympatric bird species known as capuchino seedeaters, which are differentiated in sexually selected characters of male plumage and song. We sequenced the genomes of a phenotypically diverse set of species to search for differentiated genomic regions. Capuchinos show differences in a small proportion of their genomes, yet selection has acted independently on the same targets in different members of this radiation. Many divergent regions contain genes involved in the melanogenesis pathway, with the strongest signal originating from putative regulatory regions. Selection has acted on these same genomic regions in different lineages, likely shaping the evolution of cis-regulatory elements, which control how more conserved genes are expressed and thereby generate diversity in classically sexually selected traits. PMID:28560331

Quick and simple estimation of bacteria using a fluorescent paracetamol dimer-Au nanoparticle composite

NASA Astrophysics Data System (ADS)

Sahoo, Amaresh Kumar; Sharma, Shilpa; Chattopadhyay, Arun; Ghosh, Siddhartha Sankar

2012-02-01

Rapid, simple and sensitive detection of bacterial contamination is critical for safeguarding public health and the environment. Herein, we report an easy method of detection as well as enumeration of the bacterial cell number on the basis of fluorescence quenching of a non-antibacterial fluorescent nanocomposite, consisting of paracetamol dimer (PD) and Au nanoparticles (NPs), in the presence of bacteria. The composite was synthesized by reaction of paracetamol (p-hydroxyacetanilide) with HAuCl4. The Au NPs of the composite were characterized using UV-Vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction and selected area electron diffraction analysis. The paracetamol dimer in the composite showed emission peak at 435 nm when excited at 320 nm. The method successfully detected six bacterial strains with a sensitivity of 100 CFU mL-1. The Gram-positive and Gram-negative bacteria quenched the fluorescence of the composite differently, making it possible to distinguish between the two. The TEM analysis showed interaction of the composite with bacteria without any apparent damage to the bacteria. The chi-square test established the accuracy of the method. Quick, non-specific and highly sensitive detection of bacteria over a broad range of logarithmic dilutions within a short span of time demonstrates the potential of this method as an alternative to conventional methods.Rapid, simple and sensitive detection of bacterial contamination is critical for safeguarding public health and the environment. Herein, we report an easy method of detection as well as enumeration of the bacterial cell number on the basis of fluorescence quenching of a non-antibacterial fluorescent nanocomposite, consisting of paracetamol dimer (PD) and Au nanoparticles (NPs), in the presence of bacteria. The composite was synthesized by reaction of paracetamol (p-hydroxyacetanilide) with HAuCl4. The Au NPs of the composite were characterized using UV-Vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction and selected area electron diffraction analysis. The paracetamol dimer in the composite showed emission peak at 435 nm when excited at 320 nm. The method successfully detected six bacterial strains with a sensitivity of 100 CFU mL-1. The Gram-positive and Gram-negative bacteria quenched the fluorescence of the composite differently, making it possible to distinguish between the two. The TEM analysis showed interaction of the composite with bacteria without any apparent damage to the bacteria. The chi-square test established the accuracy of the method. Quick, non-specific and highly sensitive detection of bacteria over a broad range of logarithmic dilutions within a short span of time demonstrates the potential of this method as an alternative to conventional methods. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr11837h

Genome-wide characterization and selection of expressed sequence tag simple sequence repeat primers for optimized marker distribution and reliability in peach

USDA-ARS?s Scientific Manuscript database

Expressed sequence tag (EST) simple sequence repeats (SSRs) in Prunus were mined, and flanking primers designed and used for genome-wide characterization and selection of primers to optimize marker distribution and reliability. A total of 12,618 contigs were assembled from 84,727 ESTs, along with 34...

Introduction of a Simple Experiment for the Undergraduate Organic Chemistry Laboratory Demonstrating the Lewis Acid and Shape-Selective Properties of Zeolite Na-Y

ERIC Educational Resources Information Center

Maloney, Vincent; Szczepanski, Zach

2017-01-01

A simple, inexpensive, discovery-based experiment for undergraduate organic laboratories has been developed that demonstrates the Lewis acid and shape-selective properties of zeolites. Calcined zeolite Na-Y promotes the electrophilic aromatic bromination of toluene with a significantly higher para/ortho ratio than observed under conventional…

Application of loop-mediated isothermal amplification with propidium monoazide treatment to detect live Salmonella in chicken carcasses.

PubMed

Youn, S Y; Jeong, O M; Choi, B K; Jung, S C; Kang, M S

2017-02-01

Raw chicken products are major causes of human foodborne salmonellosis worldwide. In particular, there is a significant risk of human exposure to Salmonella originating from the chicken slaughtering process. Controlling the contamination of chicken carcasses by Salmonella has been a considerable challenge in chicken-slaughtering facilities and involves routine microbiological monitoring using reliable detection methods. Simple and rapid detection methods, particularly those capable of determining cell viability, will significantly facilitate routine monitoring of Salmonella Here, we report an invA-based loop-mediated isothermal amplification method coupled with a simple propidium monoazide treatment (PMA-LAMP) for simple and rapid detection and quantification of viable Salmonella in rinse water of chicken carcasses. In this study, PMA-LAMP consistently gave negative results for isopropanol-killed Salmonella with concentrations up to 8.0 × 10 6 CFU/reaction. The detection limit of PMA-LAMP was 8.0 × 10 1 CFU/reaction with viable Salmonella in both pure culture and rinse water of chicken carcasses, and 10-fold lower than a conventional polymerase chain reaction coupled with PMA (PMA-PCR) targeting invA There was a high correlation (R 2 = 0.99 to 0.976) between LAMP time threshold (T T ) values and viable Salmonella with a quantification range of 1.0 × 10 3 to 1.0 × 10 8 CFU/mL in pure culture and rinse water of chicken carcasses. The PMA-LAMP assay took less than 2 h to detect Salmonella contaminated in test samples. Therefore, this simple and rapid method will be a very useful tool to detect live Salmonella contamination of chicken carcasses without pre-enrichment at the slaughterhouse where sanitizing treatments are commonly used. © 2016 Poultry Science Association Inc.

Research on seamless development of surgical instruments based on biological mechanisms using CAD and 3D printer.

PubMed

Yamamoto, Ikuo; Ota, Ren; Zhu, Rui; Lawn, Murray; Ishimatsu, Takakazu; Nagayasu, Takeshi; Yamasaki, Naoya; Takagi, Katsunori; Koji, Takehiko

2015-01-01

In the area of manufacturing surgical instruments, the ability to rapidly design, prototype and test surgical instruments is critical. This paper provides a simple case study of the rapid development of two bio-mechanism based surgical instruments which are ergonomic, aesthetic and were successfully designed, prototyped and conceptually tested in a very short period of time.

Systematic Development and Validation of a Thin-Layer Densitometric Bioanalytical Method for Estimation of Mangiferin Employing Analytical Quality by Design (AQbD) Approach.

PubMed

Khurana, Rajneet Kaur; Rao, Satish; Beg, Sarwar; Katare, O P; Singh, Bhupinder

2016-01-01

The present work aims at the systematic development of a simple, rapid and highly sensitive densitometry-based thin-layer chromatographic method for the quantification of mangiferin in bioanalytical samples. Initially, the quality target method profile was defined and critical analytical attributes (CAAs) earmarked, namely, retardation factor (Rf), peak height, capacity factor, theoretical plates and separation number. Face-centered cubic design was selected for optimization of volume loaded and plate dimensions as the critical method parameters selected from screening studies employing D-optimal and Plackett-Burman design studies, followed by evaluating their effect on the CAAs. The mobile phase containing a mixture of ethyl acetate : acetic acid : formic acid : water in a 7 : 1 : 1 : 1 (v/v/v/v) ratio was finally selected as the optimized solvent for apt chromatographic separation of mangiferin at 262 nm withRf 0.68 ± 0.02 and all other parameters within the acceptance limits. Method validation studies revealed high linearity in the concentration range of 50-800 ng/band for mangiferin. The developed method showed high accuracy, precision, ruggedness, robustness, specificity, sensitivity, selectivity and recovery. In a nutshell, the bioanalytical method for analysis of mangiferin in plasma revealed the presence of well-resolved peaks and high recovery of mangiferin. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Rapid flow cytometric measurement of protein inclusions and nuclear trafficking

PubMed Central

Whiten, D. R.; San Gil, R.; McAlary, L.; Yerbury, J. J.; Ecroyd, H.; Wilson, M. R.

2016-01-01

Proteinaceous cytoplasmic inclusions are an indicator of dysfunction in normal cellular proteostasis and a hallmark of many neurodegenerative diseases. We describe a simple and rapid new flow cytometry-based method to enumerate, characterise and, if desired, physically recover protein inclusions from cells. This technique can analyse and resolve a broad variety of inclusions differing in both size and protein composition, making it applicable to essentially any model of intracellular protein aggregation. The method also allows rapid quantification of the nuclear trafficking of fluorescently labelled molecules. PMID:27516358

A Flexible Mechanism of Rule Selection Enables Rapid Feature-Based Reinforcement Learning

PubMed Central

Balcarras, Matthew; Womelsdorf, Thilo

2016-01-01

Learning in a new environment is influenced by prior learning and experience. Correctly applying a rule that maps a context to stimuli, actions, and outcomes enables faster learning and better outcomes compared to relying on strategies for learning that are ignorant of task structure. However, it is often difficult to know when and how to apply learned rules in new contexts. In our study we explored how subjects employ different strategies for learning the relationship between stimulus features and positive outcomes in a probabilistic task context. We test the hypothesis that task naive subjects will show enhanced learning of feature specific reward associations by switching to the use of an abstract rule that associates stimuli by feature type and restricts selections to that dimension. To test this hypothesis we designed a decision making task where subjects receive probabilistic feedback following choices between pairs of stimuli. In the task, trials are grouped in two contexts by blocks, where in one type of block there is no unique relationship between a specific feature dimension (stimulus shape or color) and positive outcomes, and following an un-cued transition, alternating blocks have outcomes that are linked to either stimulus shape or color. Two-thirds of subjects (n = 22/32) exhibited behavior that was best fit by a hierarchical feature-rule model. Supporting the prediction of the model mechanism these subjects showed significantly enhanced performance in feature-reward blocks, and rapidly switched their choice strategy to using abstract feature rules when reward contingencies changed. Choice behavior of other subjects (n = 10/32) was fit by a range of alternative reinforcement learning models representing strategies that do not benefit from applying previously learned rules. In summary, these results show that untrained subjects are capable of flexibly shifting between behavioral rules by leveraging simple model-free reinforcement learning and context-specific selections to drive responses. PMID:27064794

Directions for computational mechanics in automotive crashworthiness

NASA Technical Reports Server (NTRS)

Bennett, James A.; Khalil, T. B.

1993-01-01

The automotive industry has used computational methods for crashworthiness since the early 1970's. These methods have ranged from simple lumped parameter models to full finite element models. The emergence of the full finite element models in the mid 1980's has significantly altered the research direction. However, there remains a need for both simple, rapid modeling methods and complex detailed methods. Some directions for continuing research are discussed.

Simple system for locating ground loops.

PubMed

Bellan, P M

2007-06-01

A simple low-cost system for rapid identification of the cables causing ground loops in complex instrumentation configurations is described. The system consists of an exciter module that generates a 100 kHz ground loop current and a detector module that determines which cable conducts this test current. Both the exciter and detector are magnetically coupled to the ground circuit so there is no physical contact to the instrumentation system under test.

Directions for computational mechanics in automotive crashworthiness

NASA Astrophysics Data System (ADS)

Bennett, James A.; Khalil, T. B.

1993-08-01

The automotive industry has used computational methods for crashworthiness since the early 1970's. These methods have ranged from simple lumped parameter models to full finite element models. The emergence of the full finite element models in the mid 1980's has significantly altered the research direction. However, there remains a need for both simple, rapid modeling methods and complex detailed methods. Some directions for continuing research are discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weeks, J.M.; Svendsen, C.

A simple subcellular histochemical staining technique employing the lysosomal probe neutral red has been developed for use with the epiendogeic earthworm Lumbricus rubellus Hoffmeister. Coelomocytes extracted from the coelomic cavity of earthworms into an isotonic earthworm Ringer solution were allowed to adhere to a microscope slide for 30 s before the application of a neutral red dye. This red dye was rapidly accumulated within the lysosomes. Observation of the loss of this dye from these lysosomes into the surrounding cytosol has enabled the quantification of the degree of lysosomal damage caused to earthworms with exposure to an increasing range ofmore » soil copper concentrations, in both laboratory and mesocosm studies. This simple in vitro biomarker has potential for the rapid assessment of the toxic effects to earthworms from soils contaminated with heavy metals and metalloids.« less

Block Copolymer Nanocomposites with High Refractive Index Contrast for One-Step Photonics.

PubMed

Song, Dong-Po; Li, Cheng; Li, Wenhao; Watkins, James J

2016-01-26

Photonic crystals (PhCs) prepared using the self-assembly of block copolymers (BCPs) offer the potential for simple and rapid device fabrication but typically suffer from low refractive index contrast (Δn ≤ 0.1) between the phase-segregated domains. Here, we report the simple fabrication of BCP-based photonic nanocomposites with large differences in refractive index (Δn > 0.27). Zirconium oxide (ZrO2) nanoparticles coated with gallic acid are used to tune the optical constants of the target domains of self-assembled (polynorbornene-graft-poly(tert-butyl acrylate))-block-(polynorbornene-graft-poly(ethylene oxide)) (PtBA-b-PEO) brush block copolymers (BBCPs). Strong hydrogen-bonding interactions between the ligands on ZrO2 and PEO brushes of the BBCPs enable selective incorporation and high loading of up to 70 wt % (42 vol %) of the ZrO2 nanoparticles within the PEO domain, resulting in a significant increase of refractive index from 1.45 to up to 1.70. Consequently, greatly enhanced reflection at approximately 398 nm (increases of ∼250%) was observed for the photonic nanocomposites (domain spacing = 137 nm) relative to that of the unmodified BBCPs, which is consistent with numeric modeling results using transfer matrix methods. This work provides a simple strategy for a wide range tuning of optical constants of BCP domains, thereby enabling the design and creation of high-performance photonic coatings for various applications. The large refractive index contrast enables high reflectivity while simultaneously reducing the coating thickness necessary, compared to pure BCP systems.

Simple, Rapid, Sensitive, and Versatile SWNT-Paper Sensor for Environmental Toxin Detection Competitive with ELISA

PubMed Central

Wang, Libing; Chen, Wei; Xu, Dinghua; Shim, Bong Sup; Zhu, Yingyue; Sun, Fengxia; Liu, Liqiang; Peng, Chifang; Jin, Zhengyu; Xu, Chuanlai; Kotov, Nicholas A.

2009-01-01

Safety of water was for a long time and still is one of the most pressing needs for many countries and different communities. Despite the fact that there are potentially many methods to evaluate water safety, finding a simple, rapid, versatile, and inexpensive method for detection of toxins in everyday items is still a great challenge. In this study, we extend the concept of composites obtained impregnation of porous fibrous materials, such as fabrics and papers, by single walled carbon-nanotubes (SWNTs) toward very simple but high-performance biosensors. They utilize the strong dependence of electrical conductivity through nanotubes percolation network on the width of nanotubes-nanotube tunneling gap and can potentially satisfy all the requirements outlined above for the routine toxin monitoring. An antibody to the microcystin-LR (MC-LR), one of the common culprits in mass poisonings, was dispersed together with SWNTs. This dispersion was used to dip-coat the paper rendering it conductive. The change in conductivity of the paper was used to sense the MC-LR in the water rapidly and accurately. The method has the linear detection range up to 10 nmol/L and non-linear detection up to 40 nmol/L. The limit of detection was found to be 0.6 nmol/L (0.6 ng/mL), which satisfies the strictest World Health Organization standard for MC-LR content in drinking water (1 ng/mL), and is comparable to the detection limit of traditional ELISA method of MC-LR detection, while drastically reducing the time of analysis by more than an order of magnitude, which is one of the major hurdles in practical applications. Similar technology of sensor preparation can also be used for a variety of other rapid environmental sensors. PMID:19928776

A fluorescent immunochromatographic strip test using a quantum dot-antibody probe for rapid and quantitative detection of 1-aminohydantoin in edible animal tissues.

PubMed

Le, Tao; Zhang, Zhihao; Wu, Juan; Shi, Haixing; Cao, Xudong

2018-01-01

A rapid, simple, and sensitive fluorescent immunochromatographic strip test (ICST) based on quantum dots (QDs) has been developed to detect 1-aminohydantoin (AHD), a major metabolite of nitrofurantoin in animal tissues. To achieve this, QD-labeled antibody conjugates, which consist of CdSe/ZnS QDs and monoclonal antibodies, were prepared by an activated ester method. Under optimal conditions, with the nitrophenyl derivative of AHD as the target, the ICST had a linear range from 0.1 to 100 ng/mL, with a correlation coefficient of 0.9656 and a 50% inhibitory concentration of 4.51 ng/mL. The limit of detection was 0.14 ng/g, which was below the minimum required performance limit of 1 μg/kg for AHD established by the European Commission. The recoveries for AHD ranged from 81.5% to 108.2%, with coefficients of variation below 13%, based on intraday and interday analysis. Furthermore, for AHD in real samples, the ICST showed high reliability and high correlation with liquid chromatography-tandem mass spectrometry (correlation coefficient of 0.9916). To the best of our knowledge, this is the first report of a novel and sensitive method based on a fluorescent ICST to detect AHD below the minimum required performance limit. The ICST demonstrated high reliability, and could be ideally suited for rapid, simple, and on-site screening of AHD contamination in animal tissues. Graphical abstract A rapid, simple, and sensitive fluorescent immunochromatographic strip test that is based on quantum dots was developed to detect 1-aminohydantoin (AHD), a major metabolite of nitrofurantoin in animal tissues. 2-NBA 2-nitrobenzaldehyde, NP nitrophenyl.

Rapid, in situ detection of cocaine residues based on paper spray ionization coupled with ion mobility spectrometry.

PubMed

Li, Ming; Zhang, Jingjing; Jiang, Jie; Zhang, Jing; Gao, Jing; Qiao, Xiaolin

2014-04-07

In this paper, a novel approach based on paper spray ionization coupled with ion mobility spectrometry (PSI-IMS) was developed for rapid, in situ detection of cocaine residues in liquid samples and on various surfaces (e.g. glass, marble, skin, wood, fingernails), without tedious sample pretreatment. The obvious advantages of PSI are its low cost, easy operation and simple configuration without using nebulizing gas or discharge gas. Compared with mass spectrometry, ion mobility spectrometry (IMS) takes advantage of its low cost, easy operation, and simple configuration without requiring a vacuum system. Therefore, IMS is a more congruous detection method for PSI in the case of rapid, in situ analysis. For the analysis of cocaine residues in liquid samples, dynamic responses from 5 μg mL(-1) to 200 μg mL(-1) with a linear coefficient (R(2)) of 0.992 were obtained. In this case, the limit of detection (LOD) was calculated to be 2 μg mL(-1) as signal to noise (S/N) was 3 with a relative standard deviation (RSD) of 6.5% for 11 measurements (n = 11). Cocaine residues on various surfaces such as metal, glass, marble, wood, skin, and fingernails were also directly analyzed before wiping the surfaces with a piece of paper. The LOD was calculated to be as low as 5 ng (S/N = 3, RSD = 6.3%, n = 11). This demonstrates the capability of the PSI-IMS method for direct detection of cocaine residues at scenes of cocaine administration. Our results show that PSI-IMS is a simple, sensitive, rapid and economical method for in situ detection of this illicit drug, which could help governments to combat drug abuse.

Monosodium glutamate for simple photometric iron analysis

NASA Astrophysics Data System (ADS)

Prasetyo, E.

2018-01-01

Simple photometric method for iron analysis using monosodium glutamate (MSG) was proposed. The method could be used as an alternative method, which was technically simple, economic, quantitative, readily available, scientifically sound and environmental friendly. Rapid reaction of iron (III) with glutamate in sodium chloride-hydrochloric acid buffer (pH 2) to form red-brown complex was served as a basis in the photometric determination, which obeyed the range of iron (III) concentration 1.6 - 80 µg/ml. This method could be applied to determine iron concentration in soil with satisfactory results (accuracy and precision) compared to other photometric and atomic absorption spectrometry results.

Simple measurement of lenticular lens quality for autostereoscopic displays

NASA Astrophysics Data System (ADS)

Gray, Stuart; Boudreau, Robert A.

2013-03-01

Lenticular lens based autostereoscopic 3D displays are finding many applications in digital signage and consumer electronics devices. A high quality 3D viewing experience requires the lenticular lens be properly aligned with the pixels on the display device so that each eye views the correct image. This work presents a simple and novel method for rapidly assessing the quality of a lenticular lens to be used in autostereoscopic displays. Errors in lenticular alignment across the entire display are easily observed with a simple test pattern where adjacent views are programmed to display different colors.

Cellulose-lanthanum hydroxide nanocomposite as a selective marker for detection of toxic copper

PubMed Central

2014-01-01

In this current report, a simple, reliable, and rapid method based on modifying the cellulose surface by doping it with different percentages of lanthanum hydroxide (i.e., 1% La(OH)3-cellulose (LC), 5% La(OH)3-cellulose (LC2), and 10% La(OH)3-cellulose (LC3)) was proposed as a selective marker for detection of copper (Cu(II)) in aqueous medium. Surface properties of the newly modified cellulose phases were confirmed by Fourier transform infrared spectroscopy, field emission scanning electron microscope, energy dispersive X-ray spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopic analysis. The effect of pH on the adsorption of modified cellulose phases for Cu(II) was evaluated, and LC3 was found to be the most selective for Cu(II) at pH 6.0. Other parameters, influencing the maximum uptake of Cu(II) on LC3, were also investigated for a deeper mechanistic understanding of the adsorption phenomena. Results showed that the adsorption capacity for Cu(II) was improved by 211% on the LC3 phase as compared to diethylaminoethyl cellulose phase after only 2 h contact time. Adsorption isotherm data established that the adsorption process nature was monolayer with a homogeneous adsorbent surface. Results displayed that the adsorption of Cu(II) onto the LC3 phase obeyed a pseudo-second-order kinetic model. Selectivity studies toward eight metal ions, i.e., Cd(II), Co(II), Cr(III), Cr(VI), Cu(II), Fe(III), Ni(II), and Zn(II), were further performed at the optimized pH value. Based on the selectivity study, it was found that Cu(II) is highly selective toward the LC3 phase. Moreover, the efficiency of the proposed method was supported by implementing it to real environmental water samples with adequate results. PMID:25258599

Adaptation to Human Populations Is Revealed by Within-Host Polymorphisms in HIV-1 and Hepatitis C Virus

PubMed Central

Poon, Art F. Y; Kosakovsky Pond, Sergei L.; Bennett, Phil; Richman, Douglas D; Leigh Brown, Andrew J.; Frost, Simon D. W

2007-01-01

CD8+ cytotoxic T-lymphocytes (CTLs) perform a critical role in the immune control of viral infections, including those caused by human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV). As a result, genetic variation at CTL epitopes is strongly influenced by host-specific selection for either escape from the immune response, or reversion due to the replicative costs of escape mutations in the absence of CTL recognition. Under strong CTL-mediated selection, codon positions within epitopes may immediately “toggle” in response to each host, such that genetic variation in the circulating virus population is shaped by rapid adaptation to immune variation in the host population. However, this hypothesis neglects the substantial genetic variation that accumulates in virus populations within hosts. Here, we evaluate this quantity for a large number of HIV-1– (n ≥ 3,000) and HCV-infected patients (n ≥ 2,600) by screening bulk RT-PCR sequences for sequencing “mixtures” (i.e., ambiguous nucleotides), which act as site-specific markers of genetic variation within each host. We find that nonsynonymous mixtures are abundant and significantly associated with codon positions under host-specific CTL selection, which should deplete within-host variation by driving the fixation of the favored variant. Using a simple model, we demonstrate that this apparently contradictory outcome can be explained by the transmission of unfavorable variants to new hosts before they are removed by selection, which occurs more frequently when selection and transmission occur on similar time scales. Consequently, the circulating virus population is shaped by the transmission rate and the disparity in selection intensities for escape or reversion as much as it is shaped by the immune diversity of the host population, with potentially serious implications for vaccine design. PMID:17397261

A novel aptamer-based online magnetic solid phase extraction method for the selective determination of 8-hydroxy-2'-deoxyguanosine in human urine.

PubMed

Gan, Haijiao; Xu, Hui

2018-05-30

In this work, an innovative magnetic aptamer adsorbent (Fe 3 O 4 -aptamer MNPs) was synthesized for the selective extraction of 8-hydroxy-2'-deoxyguanosine (8-OHdG). Amino-functionalized-Fe 3 O 4 was crosslinked with 8-OHdG aptamer by glutaraldehyde and fixed into a steel stainless tube as the sorbent of magnetic solid phase extraction (MSPE). After selective extraction by the aptamer adsorbent, the adsorbed 8-OHdG was desorbed dynamically and online analyzed by high performance liquid chromatography-mass spectrometry (HPLC-MS). The synthesized sorbent presented outstanding features, including specific selectivity, high enrichment capacity, stability and biocompatibility. Moreover, this proposed MSPE-HPLC-MS can achieve adsorption and desorption operation integration, greatly simplify the analysis process and reduce human errors. When compared with offline MSPE, a sensitivity enhancement of 800 times was obtained for the online method. Some experimental parameters such as the amount of the sorbent, sample flow rate and sample volume, were optimized systematically. Under the optimal conditions, low limit of detection (0.01 ng mL -1 , S/N = 3), limit of quantity (0.03 ng mL -1 , S/N = 10) and wide linear range with a satisfactory correlation coefficient (R 2  ≥ 0.9992) were obtained. And the recoveries of 8-OHdG in the urine samples varied from 82% to 116%. All these results revealed that the method is simple, rapid, selective, sensitive and automated, and it could be expected to become a potential approach for the selective determination of trace 8-OHdG in complex urinary samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Population dynamics in the presence of quasispecies effects and changing environments

NASA Astrophysics Data System (ADS)

Forster, Robert Burke

2006-12-01

This thesis explores how natural selection acts on organisms such as viruses that have either highly error-prone reproduction or face variable environmental conditions or both. By modeling population dynamics under these conditions, we gain a better understanding of the selective forces at work, both in our simulations and hopefully also in real organisms. With an understanding of the important factors in natural selection we can forecast not only the immediate fate of an existing population but also in what directions such a population might evolve in the future. We demonstrate that the concept of a quasispecies is relevant to evolution in a neutral fitness landscape. Motivated by RNA viruses such as HIV, we use RNA secondary structure as our model system and find that quasispecies effects arise both rapidly and in realistically small populations. We discover that the evolutionary effects of neutral drift, punctuated equilibrium and the selection for mutational robustness extend to the concept of a quasispecies. In our study of periodic environments, we consider the tradeoffs faced by quasispecies in adapting to environmental change. We develop an analytical model to predict whether evolution favors short-term or long-term adaptation and validate our model through simulation. Our results bear directly on the population dynamics of viruses such as West Nile that alternate between two host species. More generally, we discover that a selective pressure exists under these conditions to fuse or split genes with complementary environmental functions. Lastly, we study the general effects of frequency-dependent selection on two strains competing in a periodic environment. Under very general assumptions, we prove that stable coexistence rather than extinction is the likely outcome. The population dynamics of this system may be as simple as stable equilibrium or as complex as deterministic chaos.

A simple orchidometric method for the preliminary assessment of maturity status in male cynomolgus monkeys (Macaca fascicularis) used for nonclinical safety studies.

PubMed

Ku, Warren W; Pagliusi, Frank; Foley, George; Roesler, Alfred; Zimmerman, Thomas

2010-01-01

The identification and use of mature male non-human primates in nonclinical toxicology studies could be important for evaluating candidate drugs for which the profile of toxicity may differ depending on sexual maturity. This investigation sought to establish operational criteria to complement the current standard of histological evaluation for defining sexual maturity in male cynomolgus monkeys (Macaca fascicularis) used for toxicology studies, and to identify a practical non-invasive measure to select mature males for study. Retrospectively, the relationships between body weight, testicular weight and testis histology were established in control males (n=126) used in previous toxicology studies. Prospectively, testicular volumes were measured in-life by orchidometry using comparative scrotal palpation (n=23 males used for study), then compared to testicular weights measured at necropsy. Consistent with previous literature, a weak relationship was observed between body weight and testicular weight. There was, however, a very good relationship between testicular weight and histological maturation level, which was based upon microscopic examination of testes, epididymides and prostates. Orchidometric measurement of testicular volume was found to be a reasonable predictor of testicular weight and served to rapidly select sexually mature males for study, and a total testicular volume (left and right combined) of >20 ml correlated with the histological appearance of maturity. Based upon this preliminary exploratory study, the initial simple measurement of testicular volume by orchidometry may provide a non-invasive alternative approach for assessing the sexual maturity of male cynomolgus monkeys in research colonies or during toxicology studies that will require more thorough validation. Copyright 2009 Elsevier Inc. All rights reserved.

Novel Multiplex PCR Assay for Detection of Chlorhexidine-Quaternary Ammonium, Mupirocin, and Methicillin Resistance Genes, with Simultaneous Discrimination of Staphylococcus aureus from Coagulase-Negative Staphylococci

PubMed Central

McClure, Jo-Ann; Zaal DeLongchamp, Johanna; Conly, John M.

2017-01-01

ABSTRACT Methicillin-resistant Staphylococcus aureus (MRSA) is a clinically significant pathogen that is resistant to a wide variety of antibiotics and responsible for a large number of nosocomial infections worldwide. The Agency for Healthcare Research and Quality and the Centers for Disease Control and Prevention recently recommended the adoption of universal mupirocin-chlorhexidine decolonization of all admitted intensive care unit patients rather than MRSA screening with targeted treatments, which raises a serious concern about the selection of resistance to mupirocin and chlorhexidine in strains of staphylococci. Thus, a simple, rapid, and reliable approach is paramount in monitoring the prevalence of resistance to these agents. We developed a simple multiplex PCR assay capable of screening Staphylococcus isolates for the presence of antiseptic resistance genes for chlorhexidine and quaternary ammonium compounds, as well as mupirocin and methicillin resistance genes, while simultaneously discriminating S. aureus from coagulase-negative staphylococci (CoNS). The assay incorporates 7 PCR targets, including the Staphylococcus 16S rRNA gene (specifically detecting Staphylococcus spp.), nuc (distinguishing S. aureus from CoNS), mecA (distinguishing MRSA from methicillin-susceptible S. aureus), mupA and mupB (identifying high-level mupirocin resistance), and qac and smr (identifying chlorhexidine and quaternary ammonium resistance). Our assay demonstrated 100% sensitivity, specificity, and accuracy in a total of 23 variant antiseptic- and/or antibiotic-resistant control strains. Further validation of our assay using 378 randomly selected and previously well-characterized local clinical isolates confirmed its feasibility and practicality. This may prove to be a useful tool for multidrug-resistant Staphylococcus monitoring in clinical laboratories, particularly in the wake of increased chlorhexidine and mupirocin treatments. PMID:28381601

Colorimetric detection of trivalent chromium in aqueous solution using tartrate-capped silver nanoparticles as probe.

PubMed

Xu, Yunbo; Dong, Yangjun; Jiang, Xue; Zhu, Ningning

2013-10-01

This study describes a simple and highly selective method for the colorimetric detection of trivalent chromium (Cr3+) using tartrate-capped silver nanoparticles (AgNPs) as probe. The addition of tartrate to the initially prepared AgNPs gives tartrate-stabilized AgNPs ascribing to the electrostatic repulsion of the highly negatively charged tartrate ions covered on the surface of AgNPs. It is found that, in the presence of Cr3+ in aqueous solution, the aggregation of tartrate-stabilized AgNPs occurs. The color of AgNPs suspension changes from yellow to pink and the surface plasmon absorption band broadens and red shifts, which could be applied for the colorimetric detection of Cr3+ in aqueous solution. The utilization of tartrate-stabilized AgNPs as probe substantially increases the selectivity and sensitivity for colorimetric detection of Cr3+. Control experiments with the addition of over 14 other metal ions, such as Pb2+, Zn2+, Cr2O7(2-), Cd2+, Co2+, Cu2+, Al3+, Ni2+, Mn2+, Ba2+, Fe3+, Ca2+, Mg2+, Sr+ do not result in a distinct change in the color or in the spectrum of the suspension, indicating that these metal ions do not interfere with the colorimetric detection of Cr3+. Under the conditions employed here, A502/A393 (ratio of absorption value at 502 nm to 393 nm) is linear with the concentration of Cr3+ within a concentration range from 0.1 to 1.17 microM with a detection limit of 0.06 microM. This study may offer a simple, rapid and sensitive approach to colorimetric detection of Cr3+ in aqueous solution.

The Culture-Repopulating Ability Assays and Incubation in Low Oxygen: A Simple Way to Test Drugs on Leukaemia Stem or Progenitor Cells

PubMed Central

Cipolleschi, Maria Grazia; Rovida, Elisabetta; Sbarba, Persio Dello

2013-01-01

The Culture-Repopulating Ability (CRA) assays is a method to measure in vitro the bone marrow-repopulating potential of haematopoietic cells. The method was developed in our laboratory in the course of studies based on the use of growth factor-supplemented liquid cultures to study haematopoietic stem/progenitor cell resistance to, and selection at, low oxygen tensions in the incubation atmosphere. These studies led us to put forward the first hypothesis of the existence in vivo of haematopoietic stem cell niches where oxygen tension is physiologically lower than in other bone marrow areas. The CRA assays and incubation in low oxygen were later adapted to the study of leukaemias. Stabilized leukaemia cell lines, ensuring genetically homogeneous cells and enhancing repeatability of results, were found nevertheless phenotypically heterogeneous, comprising cell subsets exhibiting functional phenotypes of stem or progenitor cells. These subsets can be assayed separately, provided an experimental system capable to select one from another (such as different criteria for incubation in low oxygen) is established. On this basis, a two-step procedure was designed, including a primary culture of leukaemia cells in low oxygen for different times, where drug treatment is applied, followed by the transfer of residual cell population (CRA assay) to a drug-free secondary culture incubated at standard oxygen tension, where the expansion of population is allowed. The CRA assays, applied to cell lines first and then to primary cells, represent a simple and relatively rapid, yet accurate and reliable, method for the pre-screening of drugs potentially active on leukaemias which in our opinion could be adopted systematically before they are tested in vivo. PMID:23394087

Globalization, immigration and diabetes self-management: an empirical study amongst immigrants with type 2 diabetes mellitus in Ireland.

PubMed

Thabit, H; Shah, S; Nash, M; Brema, I; Nolan, J J; Martin, G

2009-10-01

We have previously reported that immigrants in Ireland have poorer glycemic control compared with a matched population of Irish patients. This may be associated with poor diabetes self-care and low health literacy. To compare the diabetes self-care profile of non-Irish-national patients i.e. immigrant patients (IM) and Irish patients (IR) attending a hospital diabetes clinic and to evaluate differences in health literacy between the two cohorts. We studied the differences in diabetes self-management between 52 randomly selected non-Irish-national patients with type 2 diabetes and 48 randomly selected Irish/Caucasian patients. Rapid Estimate of Adult Literacy in Medicine (REALM) was used to assess health literacy. IM had poorer glycemic control than IR (HbA1c 8.0 +/- 1.9 vs. 6.9 +/- 1.4%, P < 0.005). A significant proportion of IM forget to monitor their daily blood glucose (42.1% vs. 12.5%, P < 0.05). Family support is more important amongst IM in performing daily blood glucose monitoring (75% vs. 47.7%, P < 0.05), taking medications (81.7% vs. 42.2%, P = 0.01) and following an appropriate meal plan (87.6% vs. 62.2%, P < 0.05). Fifty-three percent can only understand simple or familiar questions about their diabetes care; 65.9% can only provide information on simple or familiar topics about their diabetes. Health literacy was found to be lower in the IM groups when assessed using REALM (52.7 vs. 61.4, P = 0.01). Those providing diabetes education and care need to be aware of differing patient expectations regarding family involvement in the care of their diabetes and the possible contribution of language problems and lower health literacy to a limited understanding of diabetes self-care.

Novel Multiplex PCR Assay for Detection of Chlorhexidine-Quaternary Ammonium, Mupirocin, and Methicillin Resistance Genes, with Simultaneous Discrimination of Staphylococcus aureus from Coagulase-Negative Staphylococci.

PubMed

McClure, Jo-Ann; Zaal DeLongchamp, Johanna; Conly, John M; Zhang, Kunyan

2017-06-01

Methicillin-resistant Staphylococcus aureus (MRSA) is a clinically significant pathogen that is resistant to a wide variety of antibiotics and responsible for a large number of nosocomial infections worldwide. The Agency for Healthcare Research and Quality and the Centers for Disease Control and Prevention recently recommended the adoption of universal mupirocin-chlorhexidine decolonization of all admitted intensive care unit patients rather than MRSA screening with targeted treatments, which raises a serious concern about the selection of resistance to mupirocin and chlorhexidine in strains of staphylococci. Thus, a simple, rapid, and reliable approach is paramount in monitoring the prevalence of resistance to these agents. We developed a simple multiplex PCR assay capable of screening Staphylococcus isolates for the presence of antiseptic resistance genes for chlorhexidine and quaternary ammonium compounds, as well as mupirocin and methicillin resistance genes, while simultaneously discriminating S. aureus from coagulase-negative staphylococci (CoNS). The assay incorporates 7 PCR targets, including the Staphylococcus 16S rRNA gene (specifically detecting Staphylococcus spp.), nuc (distinguishing S. aureus from CoNS), mecA (distinguishing MRSA from methicillin-susceptible S. aureus ), mupA and mupB (identifying high-level mupirocin resistance), and qac and smr (identifying chlorhexidine and quaternary ammonium resistance). Our assay demonstrated 100% sensitivity, specificity, and accuracy in a total of 23 variant antiseptic- and/or antibiotic-resistant control strains. Further validation of our assay using 378 randomly selected and previously well-characterized local clinical isolates confirmed its feasibility and practicality. This may prove to be a useful tool for multidrug-resistant Staphylococcus monitoring in clinical laboratories, particularly in the wake of increased chlorhexidine and mupirocin treatments. Copyright © 2017 American Society for Microbiology.

Development of a New Marker System for Identification of Spirodela polyrhiza and Landoltia punctata

PubMed Central

Feng, Bo; Fang, Yang; Xu, Zhibin; Xiang, Chao; Zhou, Chunhong; Jiang, Fei; Wang, Tao

2017-01-01

Lemnaceae (commonly called duckweed) is an aquatic plant ideal for quantitative analysis in plant sciences. Several species of this family represent the smallest and fastest growing flowering plants. Different ecotypes of the same species vary in their biochemical and physiological properties. Thus, selecting of desirable ecotypes of a species is very important. Here, we developed a simple and rapid molecular identification system for Spirodela polyrhiza and Landoltia punctata based on the sequence polymorphism. First, several pairs of primers were designed and three markers were selected as good for identification. After PCR amplification, DNA fragments (the combination of three PCR products) in different duckweeds were detected using capillary electrophoresis. The high-resolution capillary electrophoresis displayed high identity to the sequencing results. The combination of the PCR products containing several DNA fragments highly improved the identification frequency. These results indicate that this method is not only good for interspecies identification but also ideal for intraspecies distinguishing. Meanwhile, 11 haplotypes were found in both the S. polyrhiza and L. punctata ecotypes. The results suggest that this marker system is useful for large-scale identification of duckweed and for the screening of desirable ecotypes to improve the diverse usage in duckweed utilization. PMID:28168191

Hierarchical hybrid film of MnO2 nanoparticles/multi-walled fullerene nanotubes-graphene for highly selective sensing of hydrogen peroxide.

PubMed

Pan, Yang; Hou, Zhaohui; Yi, Wei; Zhu, Wei; Zeng, Fanyan; Liu, You-Nian

2015-08-15

Hierarchical hybrid films of MnO2 nanoparticles/multi-walled fullerene nanotubes-graphene (MNPs/MWFNTs-GS) have been prepared via a simple wet-chemical method. For this purpose, MWFNTs (~300nm in length) are fabricated from tailoring multi-walled carbon nanotubes (MWCNTs), and then inserted into GS to pile up into a hierarchical hybrid film with the in situ formative MNPs. Scanning electron microscope, transmission electron microscope and X-ray diffraction are used to confirm the morphology and structure of the as-obtained film. The electrochemical studies reveal that MNPs/MWFNTs-GS exhibit significantly enhanced electrocatalytic activity compared with MNPs/GS, and show a rapid response to H2O2 over a wide linear range of 2.0μM-8.44mM with a high sensitivity of 206.3μA mM(-1)cm(-2) and an excellent selectivity. These favorable electrochemical detection properties may be mainly attributed to the introduction of MWFNTs, which helps to promote the electron/ion transport between MNPs and GS and form the hierarchical film structure. Copyright © 2015 Elsevier B.V. All rights reserved.

[Clinical study of tissue-selecting therapy in the treatment of mixed hemorrhoids: a single-blind randomized controlled trail].

PubMed

He, Hongyan; He, Ping; Liu, Ning

2014-06-01

To evaluate the clinical efficacy and safety of tissue-selecting therapy (TST) in treatment of mixed hemorrhoids. A single-blind randomized study was carried out. A total of 120 patients with mixed hemorrhoids from January to December 2012 were prospectively enrolled in the study and equally divided into two groups, TST group and procedure for prolapse and hemorrhoids(PPH) group. Surgical data, efficacy and postoperative complications were compared between the two groups. As compared to PPH group, patients in TST group had shorter operation time [(15.9±5.18) min vs. (22.6±7.1) min, P<0.05], lower scores of rectal urgency (0.5±0.2 vs. 1.5±1.4, P<0.05), and shorter hospital stay [(11.2±3.7) d vs. (14.8±3.7) d, P<0.05]. No anastomotic stricture case was found in TST group, while 11 cases(18.3%) developed anastomotic stricture in PPH group. There were no significant differences in effective rate and pain score of first defecation between the two groups. TST is reliable and safe for mixed hemorrhoids with the advantage of simple, rapid recovery and less complications.

UHPLC-UV method for the determination of flavonoids in dietary supplements and for evaluation of their antioxidant activities.

PubMed

Magiera, Sylwia; Baranowska, Irena; Lautenszleger, Anna

2015-01-01

A simple and rapid ultra-high performance liquid chromatographic (UHPLC) method coupled with an ultraviolet detector (UV) has been developed and validated for the separation and determination of 14 major flavonoids ((±)-catechin, (-)-epicatechin, glycitin, (-)-epicatechin gallate, rutin, quercitrin, hesperidine, neohesperidine, daidzein, glycitein, quercetin, genistein, hesperetin, and biochanin A) in herbal dietary supplements. The flavonoids have been separated on a Chromolith Fast Gradient Monolithic RP-18e column utilizing a mobile phase composed of 0.05% trifluoroacetic acid in water and acetonitrile in gradient elution mode. Under these conditions, flavonoids were separated in a 5 min run. The selectivity of the developed UHPLC-UV method was confirmed by comparison with ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. The validation parameters such as linearity, sensitivity, precision, and accuracy were found to be highly satisfactory. The optimized method was applied to determination of flavonoids in different dietary supplements. Additionally, the developed HPLC-UV method combined with 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) assay was used in the evaluation of antioxidant activity of the selected flavonoids. Copyright © 2014 Elsevier B.V. All rights reserved.

A highly selective colorimetric and ratiometric fluorescent probe for instantaneous sensing of Hg2+ in water, soil and seafood and its application on test strips.

PubMed

Lan, Linxin; Niu, Qingfen; Li, Tianduo

2018-09-06

A new simple and efficient oligothiophene-based colorimetric and ratiometric fluorescent probe has been developed for highly sensitive and fast detection of Hg 2+ in water, soil and seafood. The probe 5-(1,3-dithiolan-2-yl)-2,2':5',2″-terthiophene 3 TS can selectively detect Hg 2+ via the Hg 2+ -promoted deprotection reaction of thioacetals, which caused a remarkable color change from colorless to yellow and a strong fluorescence enhancement with emission color varying from blue to yellow, enabling naked-eye detection of Hg 2+ . The probe shows high sensitivity with the detection limit down to 1.03 × 10 -8  M. Visual color changes of 3 TS were observed on filter paper and TLC testing strips when they were impregnated on testing strips and immersed in Hg 2+ solution. Moreover, the probe 3 TS has been successfully used to rapidly detect trace amounts of hazardous Hg 2+ ions in tap, distilled, river and lake water, cropland soil, fish, shrimp and kelp samples with acceptable results and good recoveries. Copyright © 2018 Elsevier B.V. All rights reserved.

Disposable amperometric biosensor based on nanostructured bacteriophages for glucose detection

NASA Astrophysics Data System (ADS)

Kang, Yu Ri; Hwang, Kyung Hoon; Kim, Ju Hwan; Nam, Chang Hoon; Kim, Soo Won

2010-10-01

The selection of electrode material profoundly influences biosensor science and engineering, as it heavily influences biosensor sensitivity. Here we propose a novel electrochemical detection method using a working electrode consisting of bio-nanowires from genetically modified filamentous phages and nanoparticles. fd-tet p8MMM filamentous phages displaying a three-methionine (MMM) peptide on the major coat protein pVIII (designated p8MMM phages) were immobilized on the active area of an electrochemical sensor through physical adsorption and chemical bonding. Bio-nanowires composed of p8MMM phages and silver nanoparticles facilitated sensitive, rapid and selective detection of particular molecules. We explored whether the composite electrode with bio-nanowires was an effective platform to detect the glucose oxidase. The current response of the bio-nanowire sensor was high at various glucose concentrations (0.1 µm-0.1 mM). This method provides a considerable advantage to demonstrate analyte detection over low concentration ranges. Especially, phage-enabled bio-nanowires can serve as receptors with high affinity and specificity for the detection of particular biomolecules and provide a convenient platform for designing site-directed multifunctional scaffolds based on bacteriophages and may serve as a simple method for label-free detection.

FuzzObserver

NASA Technical Reports Server (NTRS)

Howard, Ayanna; Bayard, David

2006-01-01

Fuzzy Feature Observation Planner for Small Body Proximity Observations (FuzzObserver) is a developmental computer program, to be used along with other software, for autonomous planning of maneuvers of a spacecraft near an asteroid, comet, or other small astronomical body. Selection of terrain features and estimation of the position of the spacecraft relative to these features is an essential part of such planning. FuzzObserver contributes to the selection and estimation by generating recommendations for spacecraft trajectory adjustments to maintain the spacecraft's ability to observe sufficient terrain features for estimating position. The input to FuzzObserver consists of data from terrain images, including sets of data on features acquired during descent toward, or traversal of, a body of interest. The name of this program reflects its use of fuzzy logic to reason about the terrain features represented by the data and extract corresponding trajectory-adjustment rules. Linguistic fuzzy sets and conditional statements enable fuzzy systems to make decisions based on heuristic rule-based knowledge derived by engineering experts. A major advantage of using fuzzy logic is that it involves simple arithmetic calculations that can be performed rapidly enough to be useful for planning within the short times typically available for spacecraft maneuvers.