WorldWideScience

Sample records for intermediate view synthesis

  1. View Synthesis for Advanced 3D Video Systems

    Directory of Open Access Journals (Sweden)

    2009-02-01

    Full Text Available Interest in 3D video applications and systems is growing rapidly and technology is maturating. It is expected that multiview autostereoscopic displays will play an important role in home user environments, since they support multiuser 3D sensation and motion parallax impression. The tremendous data rate cannot be handled efficiently by representation and coding formats such as MVC or MPEG-C Part 3. Multiview video plus depth (MVD is a new format that efficiently supports such advanced 3DV systems, but this requires high-quality intermediate view synthesis. For this, a new approach is presented that separates unreliable image regions along depth discontinuities from reliable image regions, which are treated separately and fused to the final interpolated view. In contrast to previous layered approaches, our algorithm uses two boundary layers and one reliable layer, performs image-based 3D warping only, and was generically implemented, that is, does not necessarily rely on 3D graphics support. Furthermore, different hole-filling and filtering methods are added to provide high-quality intermediate views. As a result, high-quality intermediate views for an existing 9-view auto-stereoscopic display as well as other stereo- and multiscopic displays are presented, which prove the suitability of our approach for advanced 3DV systems.

  2. View Synthesis for Advanced 3D Video Systems

    Directory of Open Access Journals (Sweden)

    Müller Karsten

    2008-01-01

    Full Text Available Abstract Interest in 3D video applications and systems is growing rapidly and technology is maturating. It is expected that multiview autostereoscopic displays will play an important role in home user environments, since they support multiuser 3D sensation and motion parallax impression. The tremendous data rate cannot be handled efficiently by representation and coding formats such as MVC or MPEG-C Part 3. Multiview video plus depth (MVD is a new format that efficiently supports such advanced 3DV systems, but this requires high-quality intermediate view synthesis. For this, a new approach is presented that separates unreliable image regions along depth discontinuities from reliable image regions, which are treated separately and fused to the final interpolated view. In contrast to previous layered approaches, our algorithm uses two boundary layers and one reliable layer, performs image-based 3D warping only, and was generically implemented, that is, does not necessarily rely on 3D graphics support. Furthermore, different hole-filling and filtering methods are added to provide high-quality intermediate views. As a result, high-quality intermediate views for an existing 9-view auto-stereoscopic display as well as other stereo- and multiscopic displays are presented, which prove the suitability of our approach for advanced 3DV systems.

  3. Biocatalytic Synthesis of Chiral Pharmaceutical Intermediates

    Directory of Open Access Journals (Sweden)

    Ramesh N. Patel

    2004-01-01

    Full Text Available The production of single enantiomers of drug intermediates has become increasingly important in the pharmaceutical industry. Chiral intermediates and fine chemicals are in high demand from both the pharmaceutical and agrochemical industries for the preparation of bulk drug substances and agricultural products. The enormous potential of microorganisms and enzymes for the transformation of synthetic chemicals with high chemo-, regio- and enantioselectivities has been demonstrated. In this article, biocatalytic processes are described for the synthesis of chiral pharmaceutical intermediates.

  4. N-Acyliminium Intermediates in Solid-Phase Synthesis

    DEFF Research Database (Denmark)

    Quement, Sebastian Thordal le; Petersen, Rico; Meldal, M.

    2010-01-01

    N-Acyliminium ions are powerful intermediates in synthetic organic chemistry. Examples of their use are numerous in solution-phase synthesis, but there are unmerited few reports on these highly reactive electrophiles in solid-phase synthesis. The present review covers the literature to date and i...

  5. View synthesis using parallax invariance

    Science.gov (United States)

    Dornaika, Fadi

    2001-06-01

    View synthesis becomes a focus of attention of both the computer vision and computer graphics communities. It consists of creating novel images of a scene as it would appear from novel viewpoints. View synthesis can be used in a wide variety of applications such as video compression, graphics generation, virtual reality and entertainment. This paper addresses the following problem. Given a dense disparity map between two reference images, we would like to synthesize a novel view of the same scene associated with a novel viewpoint. Most of the existing work is relying on building a set of 3D meshes which are then projected onto the new image (the rendering process is performed using texture mapping). The advantages of our view synthesis approach are as follows. First, the novel view is specified by a rotation and a translation which are the most natural way to express the virtual location of the camera. Second, the approach is able to synthesize highly realistic images whose viewing position is significantly far away from the reference viewpoints. Third, the approach is able to handle the visibility problem during the synthesis process. Our developed framework has two main steps. The first step (analysis step) consists of computing the homography at infinity, the epipoles, and thus the parallax field associated with the reference images. The second step (synthesis step) consists of warping the reference image into a new one, which is based on the invariance of the computed parallax field. The analysis step is working directly on the reference views, and only need to be performed once. Examples of synthesizing novel views using either feature correspondences or dense disparity map have demonstrated the feasibility of the proposed approach.

  6. Amphoteric Borylketenimines: Versatile Intermediates in the Synthesis of Borylated Heterocycles.

    Science.gov (United States)

    Kaldas, Sherif J; O'Keefe, Kowan T V; Mendoza-Sanchez, Rodrigo; Yudin, Andrei K

    2017-07-21

    We report the first synthesis of amphoteric borylketenimines from ethynyl N-methyliminodiacetic acid (MIDA) boronate and sulfonyl azides via copper catalysis. In situ trapping of these intermediates with various nucleophiles provided access to novel borylated azetidimines, iminocoumarins, amides, iminooxetanes, and amidines. The described strategy based on borylketenimines offers high levels of chemo- and regioselectivity, enabling the synthesis of unprecedented borylated molecules. This work highlights the unexplored utility of borylketenimines in the synthesis of potentially bioactive molecules. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Intermediate view synthesis for eye-gazing

    Science.gov (United States)

    Baek, Eu-Ttuem; Ho, Yo-Sung

    2015-01-01

    Nonverbal communication, also known as body language, is an important form of communication. Nonverbal behaviors such as posture, eye contact, and gestures send strong messages. In regard to nonverbal communication, eye contact is one of the most important forms that an individual can use. However, lack of eye contact occurs when we use video conferencing system. The disparity between locations of the eyes and a camera gets in the way of eye contact. The lock of eye gazing can give unapproachable and unpleasant feeling. In this paper, we proposed an eye gazing correction for video conferencing. We use two cameras installed at the top and the bottom of the television. The captured two images are rendered with 2D warping at virtual position. We implement view morphing to the detected face, and synthesize the face and the warped image. Experimental results verify that the proposed system is effective in generating natural gaze-corrected images.

  8. Methods for providing intermediates in the synthesis of atorvastatin.

    NARCIS (Netherlands)

    Dömling, Alexander Stephan Siegfried

    2016-01-01

    The invention relates to the field of medicinal chemistry, In particular, it relates to methods for providing intermediates in the synthesis of Atorvastatin, a competitive inhibitor of HMG-Co A reductase. Provided is a process for providing a compound having a Formula (I) or a pharmaceutically

  9. Microwave-assisted Synthesis of an Important Intermediate of Benazepril

    OpenAIRE

    Mistry, B; Medhane, Dipti; Mohanraj, Krishnapriya; Ghone, Sanjeevani A.

    2010-01-01

    Rapid and efficient methods for the synthesis of an important intermediate of benazepril ethyl 3-phthalimido-2,3,4,5-tetrahydro-1H-[1]benzazepin-2-one-1-acetate under the influence of microwave irradiation are described. A comparative study of conventional and microwave assisted method is briefly discussed.

  10. Microwave-assisted Synthesis of an Important Intermediate of Benazepril

    Science.gov (United States)

    Mistry, B; Medhane, Dipti; Mohanraj, Krishnapriya; Ghone, Sanjeevani A.

    2010-01-01

    Rapid and efficient methods for the synthesis of an important intermediate of benazepril ethyl 3-phthalimido-2,3,4,5-tetrahydro-1H-[1]benzazepin-2-one-1-acetate under the influence of microwave irradiation are described. A comparative study of conventional and microwave assisted method is briefly discussed. PMID:21188052

  11. Intermediate obtained from photoionization, serving as precursor for the synthesis of Schiff’s base

    Directory of Open Access Journals (Sweden)

    R. Sanjeev

    2014-05-01

    Full Text Available In this article, we have introduced an intermediate benzyl carbocation (formed as a result of photoionization which serves as precursor for the synthesis of Schiff’s base. Lifetimes of many carbocations were determined from our laboratory. During the determination of the lifetimes, our endeavor was to obtain a carbocation with high selectivity, s = knu/kH2O. The selectivity is the ratio of the rate constant of the reaction of carbocation with an externally added nucleophile, (nu, aniline to that of the rate constant of the water. Our intention was to obtain a carbocation with high selectivity, so that one can pave a path for the synthesis of Schiff’s base by the reaction of the carbocation intermediate with aniline. DOI: http://dx.doi.org/10.4314/bcse.v28i2.13

  12. Improving hospital discharge arrangements for people who are homeless: A realist synthesis of the intermediate care literature.

    Science.gov (United States)

    Cornes, Michelle; Whiteford, Martin; Manthorpe, Jill; Neale, Joanne; Byng, Richard; Hewett, Nigel; Clark, Michael; Kilmister, Alan; Fuller, James; Aldridge, Robert; Tinelli, Michela

    2018-05-01

    This review presents a realist synthesis of "what works and why" in intermediate care for people who are homeless. The overall aim was to update an earlier synthesis of intermediate care by capturing new evidence from a recent UK government funding initiative (the "Homeless Hospital Discharge Fund"). The initiative made resources available to the charitable sector to enable partnership working with the National Health Service (NHS) in order to improve hospital discharge arrangements for people who are homeless. The synthesis adopted the RAMESES guidelines and reporting standards. Electronic searches were carried out for peer-reviewed articles published in English from 2000 to 2016. Local evaluations and the grey literature were also included. The inclusion criteria was that articles and reports should describe "interventions" that encompassed most of the key characteristics of intermediate care as previously defined in the academic literature. Searches yielded 47 articles and reports. Most of these originated in the UK or the USA and fell within the realist quality rating of "thick description". The synthesis involved using this new evidence to interrogate the utility of earlier programme theories. Overall, the results confirmed the importance of (i) collaborative care planning, (ii) reablement and (iii) integrated working as key to effective intermediate care delivery. However, the additional evidence drawn from the field of homelessness highlighted the potential for some theory refinements. First, that "psychologically informed" approaches to relationship building may be necessary to ensure that service users are meaningfully engaged in collaborative care planning and second, that integrated working could be managed differently so that people are not "handed over" at the point at which the intermediate care episode ends. This was theorised as key to ensuring that ongoing care arrangements do not break down and that gains are not lost to the person or the system

  13. Microwave-assisted synthesis of α-aryl malonates: Key intermediates for the

    Directory of Open Access Journals (Sweden)

    Mohamed A. Ibrahim

    2016-11-01

    Full Text Available We disclose a new microwave-assisted protocol for the effective α-arylation of diethyl malonate. The coupling of aryl halides with diethyl malonate proceeds smoothly in short reaction time in the presence of a catalytic amount of Cu(OTf2, 2-picolinic acid and Cs2CO3 in toluene using microwave irradiation. The resulting α-aryl malonates are then used as key intermediates for synthesis of variety of heterocyclic compounds, including benzodiazepines, isoquinolines and pyrrolopyridine scaffolds.

  14. Unprecedented Carbonato Intermediates in Cyclic Carbonate Synthesis Catalysed by Bimetallic Aluminium(Salen) Complexes.

    Science.gov (United States)

    Castro-Osma, José A; North, Michael; Offermans, Willem K; Leitner, Walter; Müller, Thomas E

    2016-04-21

    The mechanism by which [Al(salen)]2 O complexes catalyse the synthesis of cyclic carbonates from epoxides and carbon dioxide in the absence of a halide cocatalyst has been investigated. Density functional theory (DFT) studies, mass spectrometry and (1) H NMR, (13) C NMR and infrared spectroscopies provide evidence for the formation of an unprecedented carbonato bridged bimetallic aluminium complex which is shown to be a key intermediate for the halide-free synthesis of cyclic carbonates from epoxides and carbon dioxide. Deuterated and enantiomerically-pure epoxides were used to study the reaction pathway. Based on the experimental and theoretical results, a catalytic cycle is proposed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Scalable synthesis and isolation of the four stereoisomers of methyl 1-amino-3-(4-bromophenyl)cyclopentanecarboxylate, useful intermediates for the synthesis of S1P1 receptor agonists.

    Science.gov (United States)

    Wallace, Grier A; Gordon, Thomas D; Hayes, Martin E; Konopacki, Donald B; Fix-Stenzel, Shannon R; Zhang, Xiaolei; Grongsaard, Pintipa; Cusack, Kevin P; Schaffter, Lisa M; Henry, Rodger F; Stoffel, Robert H

    2009-07-03

    The individual isomers of methyl 1-amino-3-(4-bromophenyl)cyclopentanecarboxylate are useful intermediates for the synthesis of S1P1 receptor agonists. Herein we describe a scalable synthesis and isolation of each of the four stereoisomers of this compound in gram quantities with >98% ee and de. The utility of this approach is demonstrated by the synthesis of ((1R,3R)-1-amino-3-(4-octylphenyl)cyclopentyl)methanol in 7 steps, 11% overall yield, and >98% ee and de.

  16. The MHD intermediate shock interaction with an intermediate wave: Are intermediate shocks physical?

    International Nuclear Information System (INIS)

    Wu, C.C.

    1988-01-01

    Contrary to the usual belief that MHD intermediate shocks are extraneous, the authors have recently shown by numerical solutions of dissipative MHD equations that intermediate shocks are admissible and can be formed through nonlinear steepening from a continuous wave. In this paper, he clarifies the differences between the conventional view and the results by studying the interaction of an MHD intermediate shock with an intermediate wave. The study reaffirms his results. In addition, the study shows that there exists a larger class of shocklike solutions in the time-dependent dissiaptive MHD equations than are given by the MHD Rankine-Hugoniot relations. it also suggests a mechanism for forming rotational discontinuities through the interaction of an intermediate shock with an intermediate wave. The results are of importance not only to the MHD shock theory but also to studies such as magnetic field reconnection models

  17. Scatter correction, intermediate view estimation and dose characterization in megavoltage cone-beam CT imaging

    Science.gov (United States)

    Sramek, Benjamin Koerner

    The ability to deliver conformal dose distributions in radiation therapy through intensity modulation and the potential for tumor dose escalation to improve treatment outcome has necessitated an increase in localization accuracy of inter- and intra-fractional patient geometry. Megavoltage cone-beam CT imaging using the treatment beam and onboard electronic portal imaging device is one option currently being studied for implementation in image-guided radiation therapy. However, routine clinical use is predicated upon continued improvements in image quality and patient dose delivered during acquisition. The formal statement of hypothesis for this investigation was that the conformity of planned to delivered dose distributions in image-guided radiation therapy could be further enhanced through the application of kilovoltage scatter correction and intermediate view estimation techniques to megavoltage cone-beam CT imaging, and that normalized dose measurements could be acquired and inter-compared between multiple imaging geometries. The specific aims of this investigation were to: (1) incorporate the Feldkamp, Davis and Kress filtered backprojection algorithm into a program to reconstruct a voxelized linear attenuation coefficient dataset from a set of acquired megavoltage cone-beam CT projections, (2) characterize the effects on megavoltage cone-beam CT image quality resulting from the application of Intermediate View Interpolation and Intermediate View Reprojection techniques to limited-projection datasets, (3) incorporate the Scatter and Primary Estimation from Collimator Shadows (SPECS) algorithm into megavoltage cone-beam CT image reconstruction and determine the set of SPECS parameters which maximize image quality and quantitative accuracy, and (4) evaluate the normalized axial dose distributions received during megavoltage cone-beam CT image acquisition using radiochromic film and thermoluminescent dosimeter measurements in anthropomorphic pelvic and head and

  18. The Impact of Silent and Freeze-Frame Viewing Techniques of Video Materials on the Intermediate EFL Learners’ Listening Comprehension

    Directory of Open Access Journals (Sweden)

    Sara Shahani

    2015-05-01

    Full Text Available The use of modern technologies has been widely prevalent among language learners, and video, in particular, as a valuable learning tool provides learners with comprehensible input. The present study investigated the effect of silent and freeze-frame viewing techniques of video materials on the intermediate English as a foreign language (EFL learners’ listening comprehension. To this end, 45 intermediate EFL learners participated in this quasi-experimental study. The results of one-way ANOVA revealed that there was a statistically significant difference between the experimental groups (using two types of viewing techniques and the control group. While the difference between the two experimental groups was not statistically significant, the experimental groups outperformed the control group significantly.

  19. The diagnostic accuracy of dual-view digital mammography, single-view breast tomo-synthesis and a dual-view combination of breast tomo-synthesis and digital mammography in a free-response observer performance study

    International Nuclear Information System (INIS)

    Svahn, T.; Andersson, I.; Chakraborty, D.; Svensson, S.; Ikeda, D.; Foernvik, D.; Mattsson, S.; Tingberg, A.; Zackrisson, S.

    2010-01-01

    The purpose of the present study was to compare the diagnostic accuracy of dual-view digital mammography (DM), single view breast tomo-synthesis (BT) and BT combined with the opposite DM view. Patients with subtle lesions were selected to undergo BT examinations. Two radiologists who are non-participants in the study and have experience in using DM and BT determined the locations and extents of lesions in the images. Five expert mammographers interpreted the cases using the free-response paradigm. The task was to mark and rate clinically reportable findings suspicious for malignancy and clinically relevant benign findings. The marks were scored with reference to the outlined regions into lesion localization or non-lesion localization, and analysed by the jackknife alternative free-response receiver operating characteristic method. The analysis yielded statistically significant differences between the combined modality and dual-view DM (p < 0.05). No differences were found between single-view BT and dual-view DM or between single-view BT and the combined modality. (authors)

  20. Improved enzymatic production of phenolated glycerides through alkyl phenolate intermediate

    DEFF Research Database (Denmark)

    Yang, Zhiyong; Feddern, Vivian; Glasius, Marianne

    2011-01-01

    This work reported a novel approach for synthesis of dihydrocaffoylated glycerides, consisting of 2 steps: enzymatic synthesis of octyl dihydrocaffeate (as a synthetic intermediate) from octanol and dihydrocaffeic acid (DHCA), and enzymatic interesterification of triglycerides with octyl dihydroc......This work reported a novel approach for synthesis of dihydrocaffoylated glycerides, consisting of 2 steps: enzymatic synthesis of octyl dihydrocaffeate (as a synthetic intermediate) from octanol and dihydrocaffeic acid (DHCA), and enzymatic interesterification of triglycerides with octyl...

  1. Saudi Intermediate School EFL Teachers' Views in the Kingdom of Saudi Arabia of the Multiple Intelligences Theory as an Inclusive Pedagogy

    Science.gov (United States)

    Kentab, Mohammad Yousef

    2016-01-01

    In this study, the researcher attempted to shed light on Saudi intermediate school EFL teachers' views of the multiple intelligences theory as an inclusive pedagogy. The purpose of this study was to investigate the impact of multiple intelligences on Saudi intermediate students' learning of EFL. The study also tried to illustrate the main…

  2. Enantiopure N-Acyldihydropyridones as Synthetic Intermediates: Asymmetric Synthesis of (-)-Septicine and (-)-Tylophorine.

    Science.gov (United States)

    Comins, Daniel L.; Chen, Xinghai; Morgan, Lawrence A.

    1997-10-17

    A concise asymmetric synthesis of (-)-septicine (1) and (-)-tylophorine (2) was accomplished with a high degree of stereocontrol in eight and nine steps, respectively. Addition of 4-(1-butenyl)magnesium bromide to 1-acylpyridinium salt 3, prepared in situ from 4-methoxy-3-(triisopropylsilyl)pyridine and the chloroformate of (-)-trans-2-(alpha-cumyl)cyclohexanol, gave a 91% yield of diastereomerically pure dihydropyridone 7. Oxidative cleavage of 7 and subsequent reduction provided alcohol 6 in 81% yield. Conversion of 6 to the chloride followed by treatment with sodium methoxide gave indolizidinone 9 in high yield. Bromination and conjugate reduction of 9 with L-Selectride, and trapping the intermediate enolate with N-(5-chloro-2-pyridyl)triflimide, provided bromovinyl triflate 11. Palladium-catalyzed cross-coupling of excess (3,4-dimethoxyphenyl)zinc bromide and 11 gave (-)-septicine (1). On the basis of this synthesis, (-)-1 was assigned the Rconfiguration. Reaction of 1 with vanadium(V) trifluoride oxide in TFA/CH(2)Cl(2) effected oxidative coupling to give a 68% yield of (-)-tylophorine (2).

  3. Spin observables at intermediate energies: a tool in viewing the nucleus

    International Nuclear Information System (INIS)

    McClelland, J.B.

    1986-01-01

    This paper attempts to summarize some of the advances made in intermediate nuclear physics through measurements of spin observables, notably in the range of bombarding energies from 100 to 1000 MeV. Relative to measurements of cross section, spin observables offer a highly selective filter in viewing the nucleus. Their general utility is found in their sensitivity to particular nuclear transitions and is further augmented by their simple connections to the NN force. The advantage of higher energies is apparent from the dominance of single-step mechanisms even at large energy losses where general nuclear spin responses may be made. Experimentally, this is an energy range where efficient, high-analyzing-power polarimeters can be coupled with high resolution detection techniques. 29 refs., 5 figs

  4. Synthesis of Enantiomerically Pure 6-Substituted-Piperazine-2-Acetic Acid Esters as Intermediates for Library Production.

    Science.gov (United States)

    Chamakuri, Srinivas; Jain, Prashi; Guduru, Shiva Krishna Reddy; Arney, Joseph Winston; MacKenzie, Kevin; Santini, Conrad; Young, Damian W

    2018-05-11

    Amino acids from the chiral pool have been used to produce a 24-member branch of 2,6-disubstituted piperazine scaffolds suitable for use in compound library production. Each scaffold was obtained as a single absolute stereoisomer in multi-gram quantities. Stereochemistry was confirmed by 2D NMR protocols and enantiomeric purity was determined by chiral HPLC. The scaffolds are intended for use as intermediates in parallel synthesis of small-molecule libraries.

  5. Surface-Bound Intermediates in Low-Temperature Methanol Synthesis on Copper. Participants and Spectators

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yong; Mei, Donghai; Peden, Charles HF; Campbell, Charles T.; Mims, Charles A.

    2015-11-03

    The reactivity of surface adsorbed species present on copper catalysts during methanol synthesis at low temperatures was studied by simultaneous infrared spectroscopy (IR) and mass spectroscopy (MS) measurements during “titration” (transient surface reaction) experiments with isotopic tracing. The results show that adsorbed formate is a major bystander species present on the surface under steady-state methanol synthesis reaction conditions, but it cannot be converted to methanol by reaction with pure H2, nor with H2 plus added water. Formate-containing surface adlayers for these experiments were produced during steady state catalysis in (a) H2:CO2 (with substantial formate coverage) and (b) moist H2:CO (with no IR visible formate species). Both these reaction conditions produce methanol at steady state with relatively high rates. Adlayers containing formate were also produced by (c) formic acid adsorption. Various "titration" gases were used to probe these adlayers at modest temperatures (T = 410-450K) and 6 bar total pressure. Methanol gas (up to ~1% monolayer equivalent) was produced in "titration" from the H2:CO2 catalytic adlayers by H2 plus water, but not by dry hydrogen. The decay in the formate IR features accelerated in the presence of added water vapor. The H2:CO:H2O catalytic adlayer produced similar methanol titration yields in H2 plus water but showed no surface formate features in IR (less than 0.2% monolayer coverage). Finally, formate from formic acid chemisorption produced no methanol under any titration conditions. Even under (H2:CO2) catalytic reaction conditions, isotope tracing showed that pre-adsorbed formate from formic acid did not contribute to the methanol produced. Although non-formate intermediates exist during low temperature methanol synthesis on copper which can be converted to methanol gas

  6. Stereochemical features of unsaturated aminodiesters - intermediates in the synthesis of Richlocaine

    Directory of Open Access Journals (Sweden)

    Meyrambek Ospanov

    2014-10-01

    Full Text Available The article provides information on the methods for synthesis of unsaturated aminodiesters, which are the key intermediates in the synthesis of N-substituted 2,5-dimethyl-piperidin-4-ones, including 1,2,5-trimetilpieridin-3-one. The developed method includes reaction of methyl ester of methacrylic acid with alkyl (alkenyl amines. The obtained N-alkyl(alkenyl-(2-methyl-2- carbmetoxyethyl methylamine are attached to acetoacetic ester being in the enol form. The optimal conditions for synthesis of N-alkyl(alkenyl-(2-methyl-2-carbethoxyethenemethylamines have been established. Results of gas chromatographic analysis has showed that, at room temperature, the reaction in polar solvents is delayed for two days. In non-polar solvents, the reaction runs with simultaneous distillation of water as an azeotrope with the solvent. Increase of the radical size at N atom has little effect on the reaction rate. Introduction of allyl radical at the nitrogen atom, apparently due to steric hindrance, resulted in lower reactivity of the monoester with allyl radical by condensation with acetoacetic ester. The structure of (1-methyl-2-carbethoxyethene-(2-methyl-2-carbmethoxyethyl methylamine has been studied by PMR spectroscopy. Study of the effect of chirality on the NMR spectra showed that, if the molecule of the organic compound has an asymmetric carbon atom, it may lead to the disappearance of the magnetic equivalence of neighboring protons or group of protons. Presence of an asymmetric carbon atom in b-position to the amino group of enamine leads to the disappearance of the magnetic equivalence of the neighboring protons is observed in the form of two quartets. For enaminodiesters, equilibrium is shifted toward the trans-S-cis conformer where less steric hindrance is pronounced.

  7. Efficient synthesis and physicochemical characterization of natural danshensu, its S isomer and intermediates thereof

    Science.gov (United States)

    Sidoryk, Katarzyna; Filip, Katarzyna; Cmoch, Piotr; Łaszcz, Marta; Cybulski, Marcin

    2018-02-01

    The synthesis and molecular structure details of R- 3,4-dihydroxyphenyl lactic acid (danshensu) and related compounds, i.e. S isomer and the key intermediates have been described. Danshensu is an important water soluble phenolic acid of Salvia miltiorrhiza herb (danshen or red sag) with numerous applications in traditional Chinese medicine (TCM). Our synthetic approach was based on the Knoevenagel condensation of the protected 3,4-dihydroxybenzaldehyd and Meldrum acid derivative, followed by asymmetric Sharples dihydroxylation, reductive mono dehydroxylation and final deprotection. All compounds were characterized by various spectroscopic techniques: 1H-, 13C- magnetic resonance (NMR); Fourier-transformed infrared (FTIR); Raman, HR mass spectroscopy. For the determination of compound optical purities original HPLC methods were developed which allowed for the efficient resolution of danshensu R and S enantiomers as well as its intermediate enantiomers, using commercially available chiral stationary phases. Furthermore, in order to better understand danshensu specificity as a potential API in drug formulation, the physicochemical properties of the compounds were studied by thermal analysis, including differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA).

  8. A qualitative evidence synthesis of employees’ views of workplace smoking reduction or cessation interventions

    Science.gov (United States)

    2013-01-01

    Background The need to reduce smoking rates is a recognised public health policy issue in many countries. The workplace offers a potential context for offering smokers’ programmes and interventions to assist smoking cessation or reduction. A qualitative evidence synthesis of employees’ views about such programmes might explain why some interventions appear effective and others not, and can be used to develop evidence-based interventions for this population and setting. Methods A qualitative evidence synthesis of primary research exploring employees’ views about workplace interventions to encourage smoking cessation, including both voluntary programmes and passive interventions, such as restrictions or bans. The method used was theory-based “best fit” framework synthesis. Results Five relevant theories on workplace smoking cessation were identified and used as the basis for an a priori framework. A comprehensive literature search, including interrogation of eight databases, retrieved 747 unique citations for the review. Fifteen primary research studies of qualitative evidence were found to satisfy the inclusion criteria. The synthesis produced an evidence-based conceptual model explaining employees’ experiences of, and preferences regarding, workplace smoking interventions. Conclusion The synthesis suggests that workplace interventions should employ a range of different elements if they are to prove effective in reducing smoking among employees. This is because an employee who feels ready and able to change their behaviour has different needs and preferences from an employee who is not at that stage. Only a multi-faceted intervention can satisfy the requirements of all employees. PMID:24274158

  9. A new intermediate for the production of flexible stable polymers

    Science.gov (United States)

    Webster, J. A.

    1973-01-01

    Method of incorporating ether linkages into perfluoroalkylene segment of a dianydride intermediate yields intermediate that may be used in synthesis of flexible, stable polyimides for use as high-temperature, solvent-resistant sealants.

  10. Model of the synthesis of trisporic acid in Mucorales showing bistability.

    Science.gov (United States)

    Werner, S; Schroeter, A; Schimek, C; Vlaic, S; Wöstemeyer, J; Schuster, S

    2012-12-01

    An important substance in the signalling between individuals of Mucor-like fungi is trisporic acid (TA). This compound, together with some of its precursors, serves as a pheromone in mating between (+)- and (-)-mating types. Moreover, intermediates of the TA pathway are exchanged between the two mating partners. Based on differential equations, mathematical models of the synthesis pathways of TA in the two mating types of an idealised Mucor-fungus are here presented. These models include the positive feedback of TA on its own synthesis. The authors compare three sub-models in view of bistability, robustness and the reversibility of transitions. The proposed modelling study showed that, in a system where intermediates are exchanged, a reversible transition between the two stable steady states occurs, whereas an exchange of the end product leads to an irreversible transition. The reversible transition is physiologically favoured, because the high-production state of TA must come to an end eventually. Moreover, the exchange of intermediates and TA is compared with the 3-way handshake widely used by computers linked in a network.

  11. Comprehensive determination of macrolide antibiotics, their synthesis intermediates and transformation products in wastewater effluents and ambient waters by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Senta, Ivan; Krizman-Matasic, Ivona; Terzic, Senka; Ahel, Marijan

    2017-08-04

    Macrolide antibiotics are a prominent group of emerging contaminants frequently found in wastewater effluents and wastewater-impacted aquatic environments. In this work, a novel analytical method for simultaneous determination of parent macrolide antibiotics (azithromycin, erythromycin, clarithromycin and roxithromycin), along with their synthesis intermediates, byproducts, metabolites and transformation products in wastewater and surface water was developed and validated. Samples were enriched using solid-phase extraction on Oasis HLB cartridges and analyzed by reversed-phase liquid chromatography coupled to electrospray ionization tandem mass spectrometry. The target macrolide compounds were separated on an ACE C18 PFP column and detected using multiple reaction monitoring in positive ionization polarity. The optimized method, which included an additional extract clean-up on strong anion-exchange cartridges (SAX), resulted in high recoveries and accuracies, low matrix effects and improved chromatographic separation of the target compounds, even in highly complex matrices, such as raw wastewater. The developed method was applied to the analysis of macrolide compounds in wastewater and river water samples from Croatia. In addition to parent antibiotics, several previously unreported macrolide transformation products and/or synthesis intermediates were detected in municipal wastewater, some of them reaching μg/L levels. Moreover, extremely high concentrations of macrolides up to mg/L level were found in pharmaceutical industry effluents, indicating possible importance of this source to the total loads into ambient waters. The results revealed a significant contribution of synthesis intermediates and transformation products to the overall mass balance of macrolides in the aquatic environment. Copyright © 2017. Published by Elsevier B.V.

  12. Cross-Aldol Reaction of Activated Carbonyls with Nitrosocarbonyl Intermediates: Stereoselective Synthesis toward α-Hydroxy-β-amino Esters and Amides.

    Science.gov (United States)

    Mallik, Sumitava; Bhajammanavar, Vinod; Ramakrishna, Isai; Baidya, Mahiuddin

    2017-07-21

    A practical and flexible strategy toward α-hydroxy-β-amino esters and amides, which are important biological motifs, based on an organocatalytic cross-aldol reaction of in situ-generated nitrosocarbonyl intermediates followed by hydrogenation is presented. The protocol features operational simplicity, high yields, a wide substrate scope, and high regio- and diastereoselectivity profiles. The utility of this method was showcased through the synthesis of bestatin analogues and indole formation.

  13. New chiral phosphinephosphinite ligands: Application to stereoselective synthesis of a key intermediate of 1{beta}-methyl carbapenems by Rh(I)-catalyzed asymmetric hydroformylation

    Energy Technology Data Exchange (ETDEWEB)

    Saito, Takao; Yoshida, Akifumi; Matsumura, Kazuhiko [Takasago International Corp., Kanagawa (Japan)] [and others

    1995-12-31

    Transition metal catalyzed asymmetric hydroformylation is an attractive and highly useful homologation process for organic synthesis. Recently, the authors reported that the Rh(I) complexes of phosphinephosphite BINAPHOS are highly efficient catalysts for enantioselective hydroformylation of a variety of olefins. This time, the authors have designed and synthesized new chiral phosphinephosphinite ligands having binaphthyl backbone, (R)-2-diarylphosphino-2{prime}-diarylphosphinoxy-1,1{prime}-binaphthy1 (hereafter abbreviated (R)-BIPNITE). The Rh(I) complexes of these ligands are effective catalysts for the asymmetric hydroformylation of 4-vinylazetidin-2-one to give the corresponding oxo-aldehyde 3{beta} as the major product in very high diastereoselectivities and in good regioselectivities. Interestingly, modifications of the aryl substituents in phosphine and phosphinite moieties afforded higher selectivities. Aldehyde 3{beta} was easily oxidized with NaClO{sub 2} to 4, a key intermediate of 1{beta}-methyl carbapenems. Thus, the present method provides a new practical route to a versatile key intermediate for the synthesis of carbapenem antibiotics.

  14. A Novel Synthesis of 1-Acetyl-4-Isopropenyl-1-Cyclopentene by Chemoselective Cyclization of 4-Methyl-3-(Oxobutyl-4-Pentenal: An Important Intermediate for Natural Product Synthesis

    Directory of Open Access Journals (Sweden)

    Castro Fernando de Lima

    1999-01-01

    Full Text Available This article presents the direct oxidation of limonene-oxide 1 with KIO4 in water, which is the best way to obtain the keto-aldehyde 3, an important intermediate in natural product synthesis. The cyclization of keto-aldehyde 3 with acidic Al2O3 proceeds chemoselectively to give ketone 4. These two reactions together increase the overall yield of ketone 4 to about 70% compared to 8% previously reported in the literature¹.

  15. Variable disparity estimation based intermediate view reconstruction in dynamic flow allocation over EPON-based access networks

    Science.gov (United States)

    Bae, Kyung-Hoon; Lee, Jungjoon; Kim, Eun-Soo

    2008-06-01

    In this paper, a variable disparity estimation (VDE)-based intermediate view reconstruction (IVR) in dynamic flow allocation (DFA) over an Ethernet passive optical network (EPON)-based access network is proposed. In the proposed system, the stereoscopic images are estimated by a variable block-matching algorithm (VBMA), and they are transmitted to the receiver through DFA over EPON. This scheme improves a priority-based access network by converting it to a flow-based access network with a new access mechanism and scheduling algorithm, and then 16-view images are synthesized by the IVR using VDE. Some experimental results indicate that the proposed system improves the peak-signal-to-noise ratio (PSNR) to as high as 4.86 dB and reduces the processing time to 3.52 s. Additionally, the network service provider can provide upper limits of transmission delays by the flow. The modeling and simulation results, including mathematical analyses, from this scheme are also provided.

  16. The Path of Carbon in Photosynthesis IV. The Identity and Sequence of the Intermediates in Sucrose Synthesis

    Science.gov (United States)

    Calvin, M.; Benson, A.

    1948-12-14

    The synthesis of sucrose from C{sup 14}0{sub 2} by green algae has been investigated and the intermediates separated by the method of paper chromatography. It is shown that sucrose is the first free sugar appearing during photosynthesis. It is apparently formed by condensation of the glucose-I-phosphate and a fructose phosphate. A series of radioautographs of paper chromatograms of extracts from plants which have photosynthesized for different periods of time has been prepared. The results indicate that 2-phosphoglyceric acid is the first product synthesized from C0{sub 2} during photosynthesis.

  17. Mobile communication and intermediality

    DEFF Research Database (Denmark)

    Helles, Rasmus

    2013-01-01

    communicative affordances of mobile devices in order to understand how people choose between them for different purposes. It is argued that mobile communication makes intermediality especially central, as the choice of medium is detached from the location of stationary media and begins to follow the user across......The article argues the importance of intermediality as a concept for research in mobile communication and media. The constant availability of several, partially overlapping channels for communication (texting, calls, email, Facebook, etc.) requires that we adopt an integrated view of the various...

  18. Synthesis of complex intermediates for the study of a dehydratase from borrelidin biosynthesis

    Directory of Open Access Journals (Sweden)

    Frank Hahn

    2014-03-01

    Full Text Available Herein, we describe the syntheses of a complex biosynthesis-intermediate analogue of the potent antitumor polyketide borrelidin and of reference molecules to determine the stereoselectivity of the dehydratase of borrelidin polyketide synthase module 3. The target molecules were obtained from a common precursor aldehyde in the form of N-acetylcysteamine (SNAc thioesters and methyl esters in 13 to 15 steps. Key steps for the assembly of the polyketide backbone of the dehydratase substrate analogue were a Yamamoto asymmetric carbocyclisation and a Sakurai allylation as well as an anti-selective aldol reaction. Reference compounds representing the E- and Z-configured double bond isomers as potential products of the dehydratase reaction were obtained from a common precursor aldehyde by Wittig olefination and Still–Gennari olefination. The final deprotection of TBS ethers and methyl esters was performed under mildly acidic conditions followed by pig liver esterase-mediated chemoselective hydrolysis. These conditions are compatible with the presence of a coenzyme A or a SNAc thioester, suggesting that they are generally applicable to the synthesis of complex polyketide-derived thioesters suited for biosynthesis studies.

  19. Intermediate view reconstruction using adaptive disparity search algorithm for real-time 3D processing

    Science.gov (United States)

    Bae, Kyung-hoon; Park, Changhan; Kim, Eun-soo

    2008-03-01

    In this paper, intermediate view reconstruction (IVR) using adaptive disparity search algorithm (ASDA) is for realtime 3-dimensional (3D) processing proposed. The proposed algorithm can reduce processing time of disparity estimation by selecting adaptive disparity search range. Also, the proposed algorithm can increase the quality of the 3D imaging. That is, by adaptively predicting the mutual correlation between stereo images pair using the proposed algorithm, the bandwidth of stereo input images pair can be compressed to the level of a conventional 2D image and a predicted image also can be effectively reconstructed using a reference image and disparity vectors. From some experiments, stereo sequences of 'Pot Plant' and 'IVO', it is shown that the proposed algorithm improves the PSNRs of a reconstructed image to about 4.8 dB by comparing with that of conventional algorithms, and reduces the Synthesizing time of a reconstructed image to about 7.02 sec by comparing with that of conventional algorithms.

  20. Divergent Synthesis of Diastereomeric Sphingosines from a Chiral Aziridine

    Energy Technology Data Exchange (ETDEWEB)

    Kang, On-Yu; Shin, Mi-Ri; Kang, Han-Young [Chungbuk National University, Gongju (Korea, Republic of)

    2016-07-15

    All four stereoisomers of sphingosines were synthesized starting from a single intermediate, chiral aziridine (2), which was efficiently prepared by enzymatic desymmetrization in an enatiopure form. Aziridine (2) was converted to 3, which was used for the synthesis of 4. Both the advanced key intermediates, vinylaziridines 3 and 4, were successfully converted to threo-sphingosines 1a and 1b, respectively. Ring-closing metathesis (RCM) using the Grubbs II catalyst was the key reaction in the synthesis. Two erythro-sphingosines 1c and 1d were synthesized by the ring-expansion reactions of vinylaziridines 3 and 4, followed by RCM reactions. The successful divergent synthesis confirmed that chiral vinylaziridine 2 can be used as a key intermediate for the synthesis of sphingosine-related natural products.

  1. Click synthesis of PET radiopharmaceuticals

    International Nuclear Information System (INIS)

    Xu Mei; Kuang Chunxiang

    2009-01-01

    Increasing attention has been focused on synthesis radiopharmaceuticals for positron emission tomography (PET). The recent years witnessed applications of click chemistry to PET radiopharmaceutical synthesis,because of its distinctive advantages including high speed,yield and stereospecificity under mild conditions. Synthesis of 18 F-labeled and 11 C-labeled radiopharmaceuticals and intermediates via click chemistry are reviewed. The future trend of click chemistry for the synthesis of PET radiopharmaceutical is prospected. (authors)

  2. Prebiotic Amino Acid Thioester Synthesis: Thiol-Dependent Amino Acid Synthesis from Formose substrates (Formaldehyde and Glycolaldehyde) and Ammonia

    Science.gov (United States)

    Weber, Arthur L.

    1998-01-01

    Formaldehyde and glycolaldehyde (substrates of the formose autocatalytic cycle) were shown to react with ammonia yielding alanine and homoserine under mild aqueous conditions in the presence of thiol catalysts. Since similar reactions carried out without ammonia yielded alpha-hydroxy acid thioesters, the thiol-dependent synthesis of alanine and homoserine is presumed to occur via amino acid thioesters-intermediates capable of forming peptides. A pH 5.2 solution of 20 mM formaldehyde, 20 mM glycolaldehyde, 20 mM ammonium chloride, 23 mM 3-mercaptopropionic acid, and 23 mM acetic acid that reacted for 35 days at 40 C yielded (based on initial formaldehyde) 1.8% alanine and 0.08% homoserine. In the absence of thiol catalyst, the synthesis of alanine and homoserine was negligible. Alanine synthesis required both formaldehyde and glycolaldehyde, but homoserine synthesis required only glycolaldehyde. At 25 days the efficiency of alanine synthesis calculated from the ratio of alanine synthesized to formaldehyde reacted was 2.1%, and the yield (based on initial formaldehyde) of triose and tetrose intermediates involved in alanine and homoserine synthesis was 0.3 and 2.1%, respectively. Alanine synthesis was also seen in similar reactions containing only 10 mM each of aldehyde substrates, ammonia, and thiol. The prebiotic significance of these reactions that use the formose reaction to generate sugar intermediates that are converted to reactive amino acid thioesters is discussed.

  3. Has Banks’ Financial Intermediation Improved in Russia?

    OpenAIRE

    Fungachova, Z.; Solanko, L.

    2010-01-01

    The aim of this paper is to analyze the increasing importance of banks in the Russian economy over the period following the financial crisis of 1998. We use several measures to assess the role of banks in domestic financial intermediation in Russia. The traditional macro-level view is complemented by the analysis of sectoral financial flows as well as by insights from micro-level studies. All of these confirm that banks are becoming increasingly important in financial intermediation. We find ...

  4. Coronavirus minus-strand RNA synthesis and effect of cycloheximide on coronavirus RNA synthesis

    International Nuclear Information System (INIS)

    Sawicki, S.G.; Sawicki, D.L.

    1986-01-01

    The temporal sequence of coronavirus plus-strand and minus-strand RNA synthesis was determined in 17CL1 cells infected with the A59 strain of mouse hepatitis virus (MHV). MHV-induced fusion was prevented by keeping the pH of the medium below pH 6.8. This had no effect on the MHV replication cycle, but gave 5- to 10-fold-greater titers of infectious virus and delayed the detachment of cells from the monolayer which permitted viral RNA synthesis to be studied conveniently until at least 10 h postinfection. Seven species of poly(A)-containing viral RNAs were synthesized at early and late times infection, in nonequal but constant ratios. MHV minus-strand RNA synthesis was first detected at about 3 h after infection and was found exclusively in the viral replicative intermediates and was not detected in 60S single-stranded form in infected cells. Early in the replication cycle, from 45 to 65% of the [ 3 H]uridine pulse-labeled RF core of purified MHV replicative intermediates was in minus-strand RNA. The rate of minus-strand synthesis peaked at 5 to 6 h postinfection and then declined to about 20% of the maximum rate. The addition of cycloheximide before 3 h postinfection prevented viral RNA synthesis, whereas the addition of cycloheximide after viral RNA synthesis had begun resulted in the inhibition of viral RNA synthesis. The synthesis of both genome and subgenomic mRNAs and of viral minus strands required continued protein synthesis, and minis-strand RNA synthesis was three- to fourfold more sensitive to inhibition of cycloheximide than was plus-strand synthesis

  5. The dermatan sulfate proteoglycan decorin modulates α2β1 integrin and the vimentin intermediate filament system during collagen synthesis.

    Directory of Open Access Journals (Sweden)

    Oliver Jungmann

    Full Text Available Decorin, a small leucine-rich proteoglycan harboring a dermatan sulfate chain at its N-terminus, is involved in regulating matrix organization and cell signaling. Loss of the dermatan sulfate of decorin leads to an Ehlers-Danlos syndrome characterized by delayed wound healing. Decorin-null (Dcn(-/- mice display a phenotype similar to that of EDS patients. The fibrillar collagen phenotype of Dcn(-/- mice could be rescued in vitro by decorin but not with decorin lacking the glycosaminoglycan chain. We utilized a 3D cell culture model to investigate the impact of the altered extracellular matrix on Dcn(-/- fibroblasts. Using 2D gel electrophoresis followed by mass spectrometry, we identified vimentin as one of the proteins that was differentially upregulated by the presence of decorin. We discovered that a decorin-deficient matrix leads to abnormal nuclear morphology in the Dcn(-/- fibroblasts. This phenotype could be rescued by the decorin proteoglycan but less efficiently by the decorin protein core. Decorin treatment led to a significant reduction of the α2β1 integrin at day 6 in Dcn(-/- fibroblasts, whereas the protein core had no effect on β1. Interestingly, only the decorin core induced mRNA synthesis, phosphorylation and de novo synthesis of vimentin indicating that the proteoglycan decorin in the extracellular matrix stabilizes the vimentin intermediate filament system. We could support these results in vivo, because the dermis of wild-type mice have more vimentin and less β1 integrin compared to Dcn(-/-. Furthermore, the α2β1 null fibroblasts also showed a reduced amount of vimentin compared to wild-type. These data show for the first time that decorin has an impact on the biology of α2β1 integrin and the vimentin intermediate filament system. Moreover, our findings provide a mechanistic explanation for the reported defects in wound healing associated with the Dcn(-/- phenotype.

  6. Single-Step Syngas-to-Distillates (S2D) Synthesis via Methanol and Dimethyl Ether Intermediates: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Dagle, Robert A.; Lebarbier, Vanessa MC; Lizarazo Adarme, Jair A.; King, David L.; Zhu, Yunhua; Gray, Michel J.; Jones, Susanne B.; Biddy, Mary J.; Hallen, Richard T.; Wang, Yong; White, James F.; Holladay, Johnathan E.; Palo, Daniel R.

    2013-11-26

    The objective of the work was to enhance price-competitive, synthesis gas (syngas)-based production of transportation fuels that are directly compatible with the existing vehicle fleet (i.e., vehicles fueled by gasoline, diesel, jet fuel, etc.). To accomplish this, modifications to the traditional methanol-to-gasoline (MTG) process were investigated. In this study, we investigated direct conversion of syngas to distillates using methanol and dimethyl ether intermediates. For this application, a Pd/ZnO/Al2O3 (PdZnAl) catalyst previously developed for methanol steam reforming was evaluated. The PdZnAl catalyst was shown to be far superior to a conventional copper-based methanol catalyst when operated at relatively high temperatures (i.e., >300°C), which is necessary for MTG-type applications. Catalytic performance was evaluated through parametric studies. Process conditions such as temperature, pressure, gas-hour-space velocity, and syngas feed ratio (i.e., hydrogen:carbon monoxide) were investigated. PdZnAl catalyst formulation also was optimized to maximize conversion and selectivity to methanol and dimethyl ether while suppressing methane formation. Thus, a PdZn/Al2O3 catalyst optimized for methanol and dimethyl ether formation was developed through combined catalytic material and process parameter exploration. However, even after compositional optimization, a significant amount of undesirable carbon dioxide was produced (formed via the water-gas-shift reaction), and some degree of methane formation could not be completely avoided. Pd/ZnO/Al2O3 used in combination with ZSM-5 was investigated for direct syngas-to-distillates conversion. High conversion was achieved as thermodynamic constraints are alleviated when methanol and dimethyl are intermediates for hydrocarbon formation. When methanol and/or dimethyl ether are products formed separately, equilibrium restrictions occur. Thermodynamic relaxation also enables the use of lower operating pressures than what

  7. Proof of the Structure of the Stemodia chilensis Tetracyclic Diterpenoid (+)-19-Acetoxystemodan-12-ol by Synthesis from (+)-Podocarpic Acid: X-ray Structure Determination of a Key Intermediate.

    Science.gov (United States)

    Leonelli, Francesca; Mostarda, Azzurra; De Angelis, Luca; Lamba, Doriano; Demitri, Nicola; La Bella, Angela; Ceccacci, Francesca; Migneco, Luisa M; Marini Bettolo, Rinaldo

    2016-04-22

    The first synthesis of (+)-19-acetoxystemodan-12-ol (1), a stemodane diterpenoid isolated from Stemodia chilensis, is described. The structure was supported by an X-ray crystallographic analysis of intermediate (+)-9a, which confirmed the proposed structure and excluded the structure of (-)-19-hydroxystemod-12-ene as a possible candidate for the Chilean Calceolaria diterpenoid to which the (-)-19-hydroxystemar-13-ene structure (9b) had been erroneously assigned.

  8. Intermediate Temperature Steam Electrolysis with Phosphate-Based Electrolytes

    DEFF Research Database (Denmark)

    Prag, Carsten Brorson

    as the technological issues and challenges faced. A setup suitable for intermediate temperature electrolysis has been constructed in order to accommodate testing in the IT region. This included the evaluation of multiple generations of components such as end plates and flow plates. Chemical vapour deposition...... treatment step of the synthesis. It was found that initial heating of the synthesis precursors to 270 _C gave a high quality sample in a reproducible fashion. Investigations of two additional novel phosphates was attempted. These were phosphoric acid treated Nb5P7O30 and a mixture of Bi2P4O13, BiPO4 and 2...

  9. Replicative intermediates in UV-irradiated Simian virus 40

    International Nuclear Information System (INIS)

    Clark, J.M.; Hanawalt, P.C.

    1984-01-01

    The authors have used Simian virus 40 (SV40) as a probe to study the replication of UV-damaged DNA in mammalian cells. Viral DNA replication in infected monkey kidney cells was synchronized by incubating a mutant of SV40 (tsA58) temperature-sensitive for the initiation of DNA synthesis at the restrictive temperature and then adding aphidicolin to temporarily inhibit DNA synthesis at the permissive temperature while permitting pre-replicative events to occur. After removal of the drug, the infected cells were irradiated at 100 J/m 2 (254 nm) to produce 6-7 pyrimidine dimers per SV40 genome, and returned to the restrictive temperature to prevent reinitiation of replication from the SV40 origin. Replicative intermediates (RI) were labeled with [ 3 H]thymidine. The size distribution of daughter DNA strands in RI isolated shortly after irradiation was skewed towards lengths less than the interdimer spacing in parental DNA; this bias persisted for at least 1 h after irradiation, but disappeared within 3 h by which time the size of the newly-synthesized DNA exceeded the interdimer distance. Evidence was obtained for the generation at late times after irradiation, of Form I molecules in which the daughter DNA strand contain dimers. Thus DNA strand exchange as well as trans-dimer synthesis may be involved in the generation of supercoiled Form I DNA from 0V-damaged SV40 replicative intermediates. (Auth.)

  10. A worked example of "best fit" framework synthesis: a systematic review of views concerning the taking of some potential chemopreventive agents.

    Science.gov (United States)

    Carroll, Christopher; Booth, Andrew; Cooper, Katy

    2011-03-16

    A variety of different approaches to the synthesis of qualitative data are advocated in the literature. The aim of this paper is to describe the application of a pragmatic method of qualitative evidence synthesis and the lessons learned from adopting this "best fit" framework synthesis approach. An evaluation of framework synthesis as an approach to the qualitative systematic review of evidence exploring the views of adults to the taking of potential agents within the context of the primary prevention of colorectal cancer. Twenty papers from North America, Australia, the UK and Europe met the criteria for inclusion. Fourteen themes were identified a priori from a related, existing conceptual model identified in the literature, which were then used to code the extracted data. Further analysis resulted in the generation of a more sophisticated model with additional themes. The synthesis required a combination of secondary framework and thematic analysis approaches and was conducted within a health technology assessment timeframe. The novel and pragmatic "best fit" approach to framework synthesis developed and described here was found to be fit for purpose. Future research should seek to test further this approach to qualitative data synthesis.

  11. Virtual Supply Chain Re-Intermediation Through Multi-Agent Systems

    National Research Council Canada - National Science Library

    Nissen, Mark

    2002-01-01

    ... inflexibility associated with EDI applications. Viewing respective procurement and order fulfillment processes of buyer and seller as an integrated whole along the supply chain, we identify opportunities for virtual supply chain re-intermediation...

  12. Synthesis of SnO2 nanoparticles through the controlled precipitation route

    International Nuclear Information System (INIS)

    Ibarguen, C. Ararat; Mosquera, A.; Parra, R.; Castro, M.S.; Rodriguez-Paez, J.E.

    2007-01-01

    The controlled precipitation method allowed to the synthesis of SnO 2 with advantageous specific properties, such as size and shape employing an aqueous SnCl 2 .2H 2 O solution as precursor. Through XRD analyses, the optimum pH value of the solution that yielded the desired product was found to be 6.25. After a thermal treatment at 600 deg. C, the final powder presented an average particle size below 50 nm with a surface area of 19 m 2 g -1 and a large reactivity. The evolution of the most important functional groups during the steps involved in this synthesis route is explained in view of the results obtained with FTIR and XRD. A thorough discussion on the different intermediates involved in the whole process is presented on the basis of hydrolysis and condensation reactions. The conclusions are supported with a complete characterization through differential and gravimetric thermal analysis (DTA/TGA), electron microscopies (SEM/TEM) and surface area determinations (BET)

  13. Carbon monosulfide: a useful synthetic intermediate

    International Nuclear Information System (INIS)

    Kramer, M.P.

    1986-01-01

    The physical properties of carbon monosulfide, CS, are well documented. The molecule has been observed in interstellar space and is found to be a common intermediate in the thermal decomposition of carbon disulfide and other sulfur compounds. Interestingly enough, the chemistry of carbon monosulfide, a molecule that is isovalent with carbon monoxide, has received little attention. The explosive nature of the carbon monosulfide monomer, which hindered previous workers, was overcome by the development of special handling techniques. The ability to produce carbon monosulfide in gram quantities had lead to synthesis of novel compounds and to a more direct synthetic route for certain known compounds. Specifically, the following general reaction demonstrates the capabilities of carbon monosulfide on the synthetic scale. CS + RXY → RXC(S)Y;(X = N,S), (Y = H, Cl). Note: The initial product formed in the reaction can be an unstable intermediate

  14. Classical model of intermediate statistics

    International Nuclear Information System (INIS)

    Kaniadakis, G.

    1994-01-01

    In this work we present a classical kinetic model of intermediate statistics. In the case of Brownian particles we show that the Fermi-Dirac (FD) and Bose-Einstein (BE) distributions can be obtained, just as the Maxwell-Boltzmann (MD) distribution, as steady states of a classical kinetic equation that intrinsically takes into account an exclusion-inclusion principle. In our model the intermediate statistics are obtained as steady states of a system of coupled nonlinear kinetic equations, where the coupling constants are the transmutational potentials η κκ' . We show that, besides the FD-BE intermediate statistics extensively studied from the quantum point of view, we can also study the MB-FD and MB-BE ones. Moreover, our model allows us to treat the three-state mixing FD-MB-BE intermediate statistics. For boson and fermion mixing in a D-dimensional space, we obtain a family of FD-BE intermediate statistics by varying the transmutational potential η BF . This family contains, as a particular case when η BF =0, the quantum statistics recently proposed by L. Wu, Z. Wu, and J. Sun [Phys. Lett. A 170, 280 (1992)]. When we consider the two-dimensional FD-BE statistics, we derive an analytic expression of the fraction of fermions. When the temperature T→∞, the system is composed by an equal number of bosons and fermions, regardless of the value of η BF . On the contrary, when T=0, η BF becomes important and, according to its value, the system can be completely bosonic or fermionic, or composed both by bosons and fermions

  15. Intermediate Collaborative Adaptive Management Strategies Build Stakeholder Capacity

    Directory of Open Access Journals (Sweden)

    Martha C. Monroe

    2013-06-01

    Full Text Available Efforts to implement collaborative adaptive management (CAM often suffer from challenges, such as an unwillingness of managers to share power, unresolved conflicts between stakeholders, and lack of capacity among stakeholders. Some aspects considered essential to CAM, e.g., trust and stakeholder capacity, may be more usefully viewed as goals for intermediate strategies rather than a set of initial conditions. From this perspective, intermediate steps that focus on social learning and building experience could overcome commonly cited barriers to CAM. An exploration of Springs Basin Working Groups, organized around major clusters of freshwater springs in north Florida, provides a case study of how these intermediate steps enable participants to become more reasonable and engaged. This strategy may be easily implemented by agencies beginning a CAM process.

  16. A critique on the theory of financial intermediation

    NARCIS (Netherlands)

    van Wensveen, D.M.N.; Scholtens, Bert

    This comment discusses the review by Franklin Alien and Anthony Santomero of the theory of financial intermediation in the 20th anniversary special issue of the Journal of Banking and Finance. We do not fully agree with their view that risk management is only of recent importance to the financial

  17. Intergalactic stellar populations in intermediate redshift clusters

    Science.gov (United States)

    Melnick, J.; Giraud, E.; Toledo, I.; Selman, F.; Quintana, H.

    2012-11-01

    A substantial fraction of the total stellar mass in rich clusters of galaxies resides in a diffuse intergalactic component usually referred to as the intracluster light (ICL). Theoretical models indicate that these intergalactic stars originate mostly from the tidal interaction of the cluster galaxies during the assembly history of the cluster, and that a significant fraction of these stars could have formed in situ from the late infall of cold metal-poor gas clouds on to the cluster. However, these models also overpredict the fraction of stellar mass in the ICL by a substantial margin, something that is still not well understood. The models also make predictions about the age distribution of the ICL stars, which may provide additional observational constraints. Here we present population synthesis models for the ICL of an intermediate redshift (z = 0.29) X-ray cluster that we have extensively studied in previous papers. The advantage of observing intermediate redshift clusters rather than nearby ones is that the former fit the field of view of multi-object spectrographs in 8-m telescopes and therefore permit us to encompass most of the ICL with only a few well-placed slits. In this paper we show that by stacking spectra at different locations within the ICL it is possible to reach sufficiently high signal-to-noise ratios to fit population synthesis models and derive meaningful results. The models provide ages and metallicities for the dominant populations at several different locations within the ICL and the brightest cluster galaxies (BCG) halo, as well as measures of the kinematics of the stars as a function of distance from the BCG. We thus find that the ICL in our cluster is dominated by old metal-rich stars, at odds with what has been found in nearby clusters where the stars that dominate the ICL are old and metal poor. While we see weak evidence of a young, metal-poor component, if real, these young stars would amount to less than 1 per cent of the total ICL

  18. Realistic Visualization of Virtual Views

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    that can be impractical and sometime impossible. In addition, the artificial nature of data often makes visualized virtual scenarios not realistic enough. Not realistic in the sense that a synthetic scene is easy to discriminate visually from a natural scene. A new field of research has consequently...... developed and received much attention in recent years: Realistic Virtual View Synthesis. The main goal is a high fidelity representation of virtual scenarios while easing modeling and physical phenomena simulation. In particular, realism is achieved by the transfer to the novel view of all the physical...... phenomena captured in the reference photographs, (i.e. the transfer of photographic-realism). An overview of most prominent approaches in realistic virtual view synthesis will be presented and briefly discussed. Applications of proposed methods to visual survey, virtual cinematography, as well as mobile...

  19. Structural and physicochemical studies of two key intermediates and the impurity in the new synthesis route of vitamin MK-7

    Science.gov (United States)

    Łaszcz, Marta; Trzcińska, Kinga; Kubiszewski, Marek; Krajewski, Krzysztof

    2018-05-01

    The MK-7 homologues of vitamin K2 are characterized by the best bioavailability among other K vitamins and act effectively in the treatment of osteoporosis and cardiovascular diseases. In this article comprehensive structural studies of two intermediates 1,4-diethoxy-2-methylnaphtalene (M2) and 1,4-diethoxy-2-methyl-3-[(2E)-3-methyl-4-(phenylsulfonyl)-2-buten-1-yl]naphtalene (M3) from the multi-step synthesis of MK-7 vitamin were described. The compounds crystallize in a monoclinic system in P21/n and P21/c for M2 and M3, respectively. Also, the isomer (2E)-4-chloro-3-methyl-1-(phenylsulfonyl)but-2-ene (M1-E verso) was isolated and the single crystal studies were performed. These three compounds were fully characterized by the 1D and 2D NMR technique as well as by Fourier-transformed infrared and Raman spectroscopies.

  20. Total synthesis of (-)- and (+)-tedanalactam

    Digital Repository Service at National Institute of Oceanography (India)

    Majik, M.S.; Parameswaran, P.S.; Tilve, S.G.

    : The Journal of Organic Chemistry, vol.74(16); 6378-6381 1 Total Synthesis of (-) and (+)-Tedanalactam Mahesh S. Majik, † Peruninakulath S. Parameswaran, ‡ and Santosh G. Tilve* ,† Department of Chemistry, Goa University, Taleigao Plateau, Goa 403..., displaying a wide range of biological activities. 1 Piperidones are key synthetic intermediates 2 for the synthesis of piperidine ring due to the presence of keto function which allows the introduction of other groups. Piperidones are also known...

  1. Efficient Lewis Acid Ionic Liquid-Catalyzed Synthesis of the Key Intermediate of Coenzyme Q10 under Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Thomas Efferth

    2010-12-01

    Full Text Available An efficient synthesis of a valuable intermediate of coenzyme Q10 by microwave-assisted Lewis acidic ionic liquid (IL-catalyzed Friedel-Crafts alkylation is reported. The acidity of six [Etpy]BF4-based ionic liquids was characterized by means of the FT-IR technique using acetonitrile as a molecular probe. The catalytic activities of these ionic liquids were correlated with their Lewis acidity. With increasing Lewis acid strength of the ionic liquids, their catalytic activity in the Friedel-Crafts reaction increased, except for [Etpy]BF4-AlCl3. The effects of the reaction system, the molar fraction of Lewis acid in the Lewis acid ILs and heating techniques were also investigated. Among the six Lewis acid ionic liquids tested [Etpy]BF4-ZnCl2 showed the best catalytic activity, with a yield of 89% after a very short reaction time (150 seconds. This procedure has the advantages of higher efficiency, better reusability of ILs, energy conservation and eco-friendliness. The method has practical value for preparation of CoQ10 on an industrial scale.

  2. On-Line Synthesis and Analysis by Mass Spectrometry

    Science.gov (United States)

    Bain, Ryan M.; Pulliam, Christopher J.; Raab, Shannon A.; Cooks, R. Graham

    2015-01-01

    In this laboratory experiment, students learn how to use ESI to accelerate chemical synthesis and to couple it with on-line mass spectrometry for structural analysis. The Hantzsch synthesis of symmetric 1,4-dihydropyridines is a classic example of a one-pot reaction in which multiple intermediates can serve to indicate the progress of the reaction…

  3. Neutrino-nucleus collision at intermediate energy

    International Nuclear Information System (INIS)

    Kosmas, T.S.; Oset, E.

    1999-01-01

    Neutrino-nucleus reactions at low and intermediate energy up to E ν = 500 MeV are studied for the most interesting nuclei from an experimental point of view. We focus on neutrino-nucleus cross-sections of semi-inclusive processes, for which recent measurements from radiochemical experiments at LAMPF and KARMEN laboratories are available. The method employed uses the modified Lindhard function for the description of the particle-hole excitations of the final nucleus via a local density approximation. (authors)

  4. An improved synthesis process of calixcrown ethers and synthesis of novel calixcrown ether

    International Nuclear Information System (INIS)

    Wang Hairong; Zhang Ping; Wang Chunmiao; Wang Jianchen; Chen Jing

    2007-01-01

    The synthesis method of calixcrown ethers was simplified and improved, and 10 L- scale synthesis was carried out. In the synthesis of the intermediates of the first three steps, the synthesis of 5, 11, 17, 23-tetra-tert-butyl-25, 26, 27, 28-tetrahydroxyl-calix[4] and its dehydroxylation were considered together, the purification procedures of the former, including re-crystallization in toluene and decolorization with activated carbon, were cancelled, and thus these steps were simplified. In the synthesis of oligoethylene glycol ditosylate, the purification method was also improved and the time-consuming column chromatography was left out. In the final step, impurities were removed by repeating stirring-settlement steps, by following recrystallization, the pure product was obtained. With these measures, the whole process could be implemented easily. The industrial scale production of calixcrown ethers could be fulfilled with the improved process. In addition, a new extracant, 25, 27-bis (n-propyloxy)calix[4]-26, 28-crown-6, is prepared and identified. (authors)

  5. Reaction Intermediate Analogues as Bisubstrate Inhibitors of Pantothenate Synthetase

    OpenAIRE

    Xu, Zhixiang; Yin, Wei; Martinelli, Leonardo K.; Evans, Joanna; Chen, Jinglei; Yu, Yang; Wilson, Daniel J.; Mizrahi, Valerie; Qiao, Chunhua; Aldrich, Courtney C.

    2014-01-01

    The biosynthesis of pantothenate, the core of coenzyme A (CoA), has been considered an attractive target for the development of antimicrobial agents since this pathway is essential in prokaryotes, but absent in mammals. Pantothenate synthetase, encoded by the gene panC, catalyzes the final condensation of pantoic acid with β–alanine to afford pantothenate via an intermediate pantoyl adenylate. We describe the synthesis and biochemical characterization of five PanC inhibitors that mimic the in...

  6. Space and Intermediality in Jia Zhang-ke’s Still Life

    Directory of Open Access Journals (Sweden)

    Cecília Mello

    2014-07-01

    Full Text Available This article is dedicated to an analysis of Chinese director Jia Zhang-ke’s film Still Life (San Xia Hao Ren 三峡好人, 2006 from the point of view of its intermedial relationship with Chinese landscape painting. As I will suggest, Jia’s discovery of a real landscape and a vanishing cityscape in this film, shot on location in the region of the Three Gorges of the Yangtze River, springs from a realist impulse and from an original aesthetic response to a new historical and social conjuncture. But while it seems firmly located in the landscape of contemporary China, the film also shares aesthetic qualities with the tradition of Chinese landscape painting, mounted on hanging or hand scrolls. A focus on this particular instance of intermediality leads to a reflection on cinema’s spatial organization in light of current revisions in film and audiovisual theory, which suggest that filmic space and its spectatorial experience should be considered above all from the point of view of touch and movement. It also allows for a broader understanding of the political implications of intermediality in Jia Zhang-ke’s oeuvre, fruit of an organic link between form and content that brings a historical resonance to a contemporary perspective.

  7. Cytochrome P450 metabolism of the post-lanosterol intermediates explains enigmas of cholesterol synthesis

    Science.gov (United States)

    Ačimovič, Jure; Goyal, Sandeep; Košir, Rok; Goličnik, Marko; Perše, Martina; Belič, Ales; Urlep, Žiga; Guengerich, F. Peter; Rozman, Damjana

    2016-06-01

    Cholesterol synthesis is among the oldest metabolic pathways, consisting of the Bloch and Kandutch-Russell branches. Following lanosterol, sterols of both branches are proposed to be dedicated to cholesterol. We challenge this dogma by mathematical modeling and with experimental evidence. It was not possible to explain the sterol profile of testis in cAMP responsive element modulator tau (Crem τ) knockout mice with mathematical models based on textbook pathways of cholesterol synthesis. Our model differs in the inclusion of virtual sterol metabolizing enzymes branching from the pathway. We tested the hypothesis that enzymes from the cytochrome P450 (CYP) superfamily can participate in the catalysis of non-classical reactions. We show that CYP enzymes can metabolize multiple sterols in vitro, establishing novel branching points of cholesterol synthesis. In conclusion, sterols of cholesterol synthesis can be oxidized further to metabolites not dedicated to production of cholesterol. Additionally, CYP7A1, CYP11A1, CYP27A1, and CYP46A1 are parts of a broader cholesterol synthesis network.

  8. Kinetic and mechanistic studies of reactive intermediates in photochemical and transition metal-assisted oxidation, decarboxylation and alkyl transfer reactions

    Energy Technology Data Exchange (ETDEWEB)

    Carraher, Jack McCaslin [Iowa State Univ., Ames, IA (United States)

    2014-01-01

    Reactive species like high-valent metal-oxo complexes and carbon and oxygen centered radicals are important intermediates in enzymatic systems, atmospheric chemistry, and industrial processes. Understanding the pathways by which these intermediates form, their relative reactivity, and their fate after reactions is of the utmost importance. Herein are described the mechanistic detail for the generation of several reactive intermediates, synthesis of precursors, characterization of precursors, and methods to direct the chemistry to more desirable outcomes yielding ‘greener’ sources of commodity chemicals and fuels.

  9. A Catalytic, Asymmetric Formal Synthesis of (+)-Hamigeran B

    KAUST Repository

    Mukherjee, Herschel

    2011-03-04

    A concise asymmetric, formal synthesis of (+)-hamigeran B is reported. A Pd-catalyzed, decarboxylative allylic alkylation, employing a trifluoromethylated derivative of t-BuPHOX, is utilized as the enantioselective step to form the critical quaternary carbon center in excellent yield and enantioselectivity. The product is converted in three steps to a late-stage intermediate previously used in the synthesis of hamigeran B.

  10. A Catalytic, Asymmetric Formal Synthesis of (+)-Hamigeran B

    KAUST Repository

    Mukherjee, Herschel; McDougal, Nolan T.; Virgil, Scott C.; Stoltz, Brian M.

    2011-01-01

    A concise asymmetric, formal synthesis of (+)-hamigeran B is reported. A Pd-catalyzed, decarboxylative allylic alkylation, employing a trifluoromethylated derivative of t-BuPHOX, is utilized as the enantioselective step to form the critical quaternary carbon center in excellent yield and enantioselectivity. The product is converted in three steps to a late-stage intermediate previously used in the synthesis of hamigeran B.

  11. Determination by high resolution liquid chromatography of 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside (Xgal) and intermediates of its synthesis

    International Nuclear Information System (INIS)

    Fernandez Villalobo, Anais; Nuevas Paz, Lauro; Rodriguez Dominguez, Juan C

    2010-01-01

    In microbiology, microorganisms markers have been found to be useful in the quality control of different products such as water and food, in which the presence of coliforms, especially E. coli has been identified. Several methods for detection and quantification of enterobacteria have been developed by using chromogenic substrates. Among them, indole derivatives such as 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside (Xgal), have come out. This indole derivative is widely employed as a constituent of microbiological diagnostic media because in the presence of coliforms (β-galactosidase producers), it forms a blue-indigo color. In this paper, the development and the validation, of an HPLC method for the quality control of Xgal in the presence of its intermediates obtained in each step of the synthesis is reported. These compounds were separated by using a RP-18 column and gradient elution with a mobile phase consisting of triethylammonium phosphate solution at pH 3(A) and acetonitrile (B). The detection and quantitation limits of the method was between 0.2- 0.5 % and 1.0 - 2.0 % respectively, which is acceptable if we consider that Xgal is not used as a drug. The proposed method is simple, selective, linear, precise and accurate and it can be used for the quality control of each of the intermediates and the final product, 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside

  12. Self-Management and Self-Management Support Outcomes: A Systematic Review and Mixed Research Synthesis of Stakeholder Views.

    Directory of Open Access Journals (Sweden)

    Emma Boger

    Full Text Available Self-management has received growing attention as an effective approach for long-term condition management. Little is known about which outcomes of supported self-management are valued by patients, their families, health professionals and those who commission self-management services. This study systematically reviewed published empirical evidence in accordance with PRISMA guidelines to determine the outcomes of self-management valued by these key stakeholder groups, using three prominent exemplar conditions: colorectal cancer, diabetes and stroke.To systematically review the literature to identify which generic outcomes of self-management have been targeted and are considered important using three exemplar conditions (colorectal cancer, diabetes and stroke, which collectively have a range of features that are likely to be representative of generic self-management issues.Systematic searching of nine electronic databases was conducted in addition to hand searches of review articles. Abstracts were identified against inclusion criteria and appraised independently by two reviewers, using a critical appraisal tool. Synthesis of findings was conducted using mixed research synthesis.Over 20,536 abstracts were screened. 41 studies which met the review criteria were fully retrieved and appraised. The majority of evidence related to diabetes. Few studies directly focussed on stakeholders' views concerning desired self-management outcomes; the majority of evidence was derived from studies focusing upon the experience of self-management. The views of health care commissioners were absent from the literature. We identified that self-management outcomes embrace a range of indicators, from knowledge, skills, and bio-psychosocial markers of health through to positive social networks.Patients', families', health professionals' and commissioners' views regarding which outcomes of self-management are important have not been clearly elicited. The extent to which

  13. Total Synthesis of balanol, Part 2

    DEFF Research Database (Denmark)

    Tanner, David Ackland; Kelly, Nicholas; Tedenborg, Lars

    1997-01-01

    A convergent enantioselective total synthesis of the natural product (-)-balanol (1) is described. In addition to benzophenone fragment 8, key intermediates are chiral bicyclic aziridine 3 and the corresponding epoxide 4, both of which undergo highly regio- and stereoselective nucleophilic ring...

  14. Synthesis of Novel Hydrocarbon Soluble Multifunctional Anionic Initiators: Tools for Synthesis of Novel Dendrimer and Molecular Brush Polymer Architectures

    Science.gov (United States)

    2015-02-09

    Synthesis of Novel Dendrimer and Molecular Brush Polymer Architectures. Research Area:7.4 The views, opinions and/or findings contained in this report...journals: Final Report: Synthesis of Novel Hydrocarbon Soluble Multifunctional Anionic Initiators: Tools for Synthesis of Novel Dendrimer and Molecular

  15. Enhancing multi-view autostereoscopic displays by viewing distance control (VDC)

    Science.gov (United States)

    Jurk, Silvio; Duckstein, Bernd; Renault, Sylvain; Kuhlmey, Mathias; de la Barré, René; Ebner, Thomas

    2014-03-01

    Conventional multi-view displays spatially interlace various views of a 3D scene and form appropriate viewing channels. However, they only support sufficient stereo quality within a limited range around the nominal viewing distance (NVD). If this distance is maintained, two slightly divergent views are projected to the person's eyes, both covering the entire screen. With increasing deviations from the NVD the stereo image quality decreases. As a major drawback in usability, the manufacturer so far assigns this distance. We propose a software-based solution that corrects false view assignments depending on the distance of the viewer. Our novel approach enables continuous view adaptation based on the calculation of intermediate views and a column-bycolumn rendering method. The algorithm controls each individual subpixel and generates a new interleaving pattern from selected views. In addition, we use color-coded test content to verify its efficacy. This novel technology helps shifting the physically determined NVD to a user-defined distance thereby supporting stereopsis. The recent viewing positions can fall in front or behind the NVD of the original setup. Our algorithm can be applied to all multi-view autostereoscopic displays — independent of the ascent or the periodicity of the optical element. In general, the viewing distance can be corrected with a factor of more than 2.5. By creating a continuous viewing area the visualized 3D content is suitable even for persons with largely divergent intraocular distance — adults and children alike — without any deficiency in spatial perception.

  16. Dimethylsulfoniopropionate biosynthesis in Spartina alterniflora: evidence that S-methylmethionine and dimethylsulfoniopropylamine are intermediates

    International Nuclear Information System (INIS)

    Kocsis, M.G.; Nolte, K.D.; Rhodes, D.; Shen, T.L.; Gage, D.A.; Hanson, A.D.

    1998-01-01

    The osmoprotectant 3-dimethylsulfoniopropionate (DMSP) occurs in Gramineae and Compositae, but its synthesis has been studied only in the latter. The DMSP synthesis pathway was therefore investigated in the salt marsh grass Spartina alterniflora Loisel. Leaf tissue metabolized supplied [35S]methionine (Met) to S-methyl-L-Met (SMM), 3-dimethylsulfoniopropylamine (DMSP-amine), and DMSP. The 35S-labeling kinetics of SMM and DMSP-amine indicated that they were intermediates and, consistent with this, the dimethylsulfonium moiety of SMM was shown by stable isotope labeling to be incorporated as a unit into DMSP. The identity of DMSP-amine, a novel natural product, was confirmed by both chemical and mass-spectral methods. S. alterniflora readily converted supplied [35S]SMM to DMSP-amine and DMSP, and also readily converted supplied [35S]DMSP-amine to DMSP; grasses that lack DMSP did neither. A small amount of label was detected in 3-dimethylsulfoniopropionaldehyde (DMSP-ald) when [35S]SMM or [35S]DMSP-amine was given. These results are consistent with the operation of the pathway Met leads to SMM leads to DMSP-amine leads to DMSP-ald leads to DMSP, which differs from that found in Compositae by the presence of a free DMSP-amine intermediate. This dissimilarity suggests that DMSP synthesis evolved independently in Gramineae and Compositae

  17. The synthesis of glutamic acid in the absence of enzymes: Implications for biogenesis

    Science.gov (United States)

    Morowitz, Harold; Peterson, Eta; Chang, Sherwood

    1995-01-01

    This paper reports on the non-enzymatic aqueous phase synthesis of amino acids from keto acids, ammonia and reducing agents. The facile synthesis of key metabolic intermediates, particularly in the glycolytic pathway, the citric acid cycle, and the first step of amino acid synthesis, lead to new ways of looking at the problem of biogenesis.

  18. Synthesis and applications of radiolabelled drugs in pharmaceutical development

    International Nuclear Information System (INIS)

    Landvatter, S.W.; Heys, J.R.; Garner, K.T.; Mack, J.F.; Senderoff, S.G.; Shu, A.Y.; Villani, A.J.; Saunders, D.

    1994-01-01

    Radiolabelled drugs play a vital role in the development of new pharmaceuticals including application in drug discovery, pre-clinical development and clinical development. The synthesis of these pharmaceuticals in tritium or carbon-14 labelled form poses many challenges for the synthetic organic chemist. The actual choice of synthetic route must take into account the small scale, limited choice and high cost of labelled precursors, and the positioning of the label into a metabolically stable position. There are, however, a number of synthetic strategies available for overcoming these constraints. Although in some C-14 syntheses the requisite labelled raw material can be purchased and the existing synthesis adapted for labelling, frequently the synthetic challenge is the synthesis of a structurally simple, yet commercially unavailable, labelled precursor (e.g., γ-butyrolactone-[2- 14 C], cyclohexanone-[ 3 H], CuCN-[ 14 C], 2-furancarboxaldehyde-[ 14 C]). Another useful strategy in C-14 synthesis is the conversion of an advanced intermediate, or perhaps the unlabelled product itself, into a precursor which can then be reconverted into the labelled version of the intermediate. Occasionally, a new total synthesis must be developed. In addition to these strategies, tritium labelling can uniquely take advantage of exchange labelling techniques, synthesis and reduction of unsaturated precursors, or tritium-halogen replacement reactions. Examples of these strategies and use of the labelled products are discussed

  19. Multistep Synthesis of a Terphenyl Derivative Showcasing the Diels-Alder Reaction

    Science.gov (United States)

    Davie, Elizabeth A. Colby

    2015-01-01

    An adaptable multistep synthesis project designed for the culmination of a second-year organic chemistry laboratory course is described. The target compound is a terphenyl derivative that is an intermediate in the synthesis of compounds used in organic light-emitting devices. Students react a conjugated diene with dimethylacetylene dicarboxylate…

  20. Asymmetric Formal Synthesis of Azadirachtin.

    Science.gov (United States)

    Mori, Naoki; Kitahara, Takeshi; Mori, Kenji; Watanabe, Hidenori

    2015-12-01

    An asymmetric formal synthesis of azadirachtin, a potent insect antifeedant, was accomplished in 30 steps to Ley's synthetic intermediate (longest linear sequence). The synthesis features: 1) rapid access to the optically active right-hand segment starting from the known 5-hydroxymethyl-2-cyclopentenone scaffold; 2) construction of the B and E rings by a key intramolecular tandem radical cyclization; 3) formation of the hemiacetal moiety in the C ring through the α-oxidation of the six-membered lactone followed by methanolysis. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. High chemoselectivity in the phenol synthesis

    Directory of Open Access Journals (Sweden)

    A. Stephen K. Hashmi

    2011-06-01

    Full Text Available Efforts to trap early intermediates of the gold-catalyzed phenol synthesis failed. Neither inter- nor intramolecularly offered vinyl groups, ketones or alcohols were able to intercept the gold carbenoid species. This indicates that the competing steps of the gold-catalyzed phenol synthesis are much faster than the steps of the interception reaction. In the latter the barrier of activation is higher. At the same time this explains the high tolerance of this very efficient and general reaction towards functional groups.

  2. Improvement of viewing-zone angle and image quality of digital holograms

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Takanori, E-mail: nom@sys.wakayama-u.ac.j [Faculty of Systems Enigneering, Wakayama Univesity, 930 Sakaedani, Wakayama, 640-8510 (Japan)

    2010-02-01

    The method to improve of a viewing-zone angle and an image quality of a digital hologram is presented. A number of digital holograms of a central object are recorded from the position on the circumference. The holograms are used for a hologram synthesis to improve the image quality from whole viewing-zone angle. The synthesis is achieved by a correlation between a hologram and numerically propagated holograms. The large-sized synthesized digital hologram has a wide viewing-zone angle and less speckles. Some experimental results are shown to confirm the proposed method.

  3. Studies toward the synthesis of Amaryllidaceae alkaloids from Morita-Baylis-Hillman adducts: a straightforward synthesis of functionalized dihydroisoquinoline-5(6H)-one core

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, Elizandra C.S.; Coelho, Fernando [Universidade Estadual de Campinas, SP (Brazil). Inst. de Quimica]. E-mail: coelho@iqm.unicamp.br

    2007-07-01

    We disclose herein our results concerning a study aiming at the synthesis of the highly substituted carbon skeleton of alkaloids isolated from plants of the Amaryllidaceae family. The total synthesis of the functionalized dihydroisoquinoline-5(6H)-one core, which is the bottom part of the structure of alkaloids isolated from this botanic family, is described, using Morita-Baylis-Hillman adducts as substrate. This compound should be a useful and valuable intermediate for the total synthesis of alkaloids isolated from Amaryllidaceae. (author)

  4. Studies toward the synthesis of Amaryllidaceae alkaloids from Morita-Baylis-Hillman adducts: a straightforward synthesis of functionalized dihydroisoquinoline-5(6H)-one core

    International Nuclear Information System (INIS)

    Lopes, Elizandra C.S.; Coelho, Fernando

    2007-01-01

    We disclose herein our results concerning a study aiming at the synthesis of the highly substituted carbon skeleton of alkaloids isolated from plants of the Amaryllidaceae family. The total synthesis of the functionalized dihydroisoquinoline-5(6H)-one core, which is the bottom part of the structure of alkaloids isolated from this botanic family, is described, using Morita-Baylis-Hillman adducts as substrate. This compound should be a useful and valuable intermediate for the total synthesis of alkaloids isolated from Amaryllidaceae. (author)

  5. Synthesis of tritium-labeled fosfomycin

    International Nuclear Information System (INIS)

    Mertel, H.E.; Meriwether, H.T.

    1982-01-01

    Tritium gas was used as a labeling agent for the preparation of [1,2- 3 H]fosfomycin. Introduction of tritium into a precursor, the synthesis including resolution of the intermediate racemic 1,2-epoxypropylphosphonic acid, and preparation of both amine and calcium salts of the labeled antibiotic are described. (author)

  6. Differential role of calpain-dependent protein cleavage in intermediate and long-term operant memory in Aplysia.

    Science.gov (United States)

    Lyons, Lisa C; Gardner, Jacob S; Lentsch, Cassidy T; Gandour, Catherine E; Krishnan, Harini C; Noakes, Eric J

    2017-01-01

    In addition to protein synthesis, protein degradation or protein cleavage may be necessary for intermediate (ITM) and long-term memory (LTM) to remove molecular constraints, facilitate persistent kinase activity and modulate synaptic plasticity. Calpains, a family of conserved calcium dependent cysteine proteases, modulate synaptic function through protein cleavage. We used the marine mollusk Aplysia californica to investigate the in vivo role of calpains during intermediate and long-term operant memory formation using the learning that food is inedible (LFI) paradigm. A single LFI training session, in which the animal associates a specific netted seaweed with the failure to swallow, generates short (30min), intermediate (4-6h) and long-term (24h) memory. Using the calpain inhibitors calpeptin and MDL-28170, we found that ITM requires calpain activity for induction and consolidation similar to the previously reported requirements for persistent protein kinase C activity in intermediate-term LFI memory. The induction of LTM also required calpain activity. In contrast to ITM, calpain activity was not necessary for the molecular consolidation of LTM. Surprisingly, six hours after LFI training we found that calpain activity was necessary for LTM, although this is a time at which neither persistent PKC activity nor protein synthesis is required for the maintenance of long-term LFI memory. These results demonstrate that calpains function in multiple roles in vivo during associative memory formation. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Pimelic acid, the first precursor of the Bacillus subtilis biotin synthesis pathway, exists as the free acid and is assembled by fatty acid synthesis.

    Science.gov (United States)

    Manandhar, Miglena; Cronan, John E

    2017-05-01

    Biotin synthetic pathways are readily separated into two stages, synthesis of the seven carbon α, ω-dicarboxylic acid pimelate moiety and assembly of the fused heterocyclic rings. The biotin pathway genes responsible for pimelate moiety synthesis vary widely among bacteria whereas the ring synthesis genes are highly conserved. Bacillus subtilis seems to have redundant genes, bioI and bioW, for generation of the pimelate intermediate. Largely consistent with previous genetic studies it was found that deletion of bioW caused a biotin auxotrophic phenotype whereas deletion of bioI did not. BioW is a pimeloyl-CoA synthetase that converts pimelic acid to pimeloyl-CoA. The essentiality of BioW for biotin synthesis indicates that the free form of pimelic acid is an intermediate in biotin synthesis although this is not the case in E. coli. Since the origin of pimelic acid in Bacillus subtilis is unknown, 13 C-NMR studies were carried out to decipher the pathway for its generation. The data provided evidence for the role of free pimelate in biotin synthesis and the involvement of fatty acid synthesis in pimelate production. Cerulenin, an inhibitor of the key fatty acid elongation enzyme, FabF, markedly decreased biotin production by B. subtilis resting cells whereas a strain having a cerulenin-resistant FabF mutant produced more biotin. In addition, supplementation with pimelic acid fully restored biotin production in cerulenin-treated cells. These results indicate that pimelic acid originating from fatty acid synthesis pathway is a bona fide precursor of biotin in B. subtilis. © 2017 John Wiley & Sons Ltd.

  8. Synthesis of azaphenanthridines via anionic ring closure

    DEFF Research Database (Denmark)

    Hansen, Henriette Møller; Lysén, M.; Begtrup, M.

    2005-01-01

    A new and convergent synthesis of azaphenanthridines via an anionic ring closure is reported. Ortho-lithiation/in situ borylation of cyanopyridines produces the corresponding cyanopyridylboronic esters, which undergo a Suzuki-Miyaura cross-coupling to give the key intermediates. Addition of lithium...

  9. Physically Inspired Models for the Synthesis of Stiff Strings with Dispersive Waveguides

    Directory of Open Access Journals (Sweden)

    Testa I

    2004-01-01

    Full Text Available We review the derivation and design of digital waveguides from physical models of stiff systems, useful for the synthesis of sounds from strings, rods, and similar objects. A transform method approach is proposed to solve the classic fourth-order equations of stiff systems in order to reduce it to two second-order equations. By introducing scattering boundary matrices, the eigenfrequencies are determined and their dependency is discussed for the clamped, hinged, and intermediate cases. On the basis of the frequency-domain physical model, the numerical discretization is carried out, showing how the insertion of an all-pass delay line generalizes the Karplus-Strong algorithm for the synthesis of ideally flexible vibrating strings. Knowing the physical parameters, the synthesis can proceed using the generalized structure. Another point of view is offered by Laguerre expansions and frequency warping, which are introduced in order to show that a stiff system can be treated as a nonstiff one, provided that the solutions are warped. A method to compute the all-pass chain coefficients and the optimum warping curves from sound samples is discussed. Once the optimum warping characteristic is found, the length of the dispersive delay line to be employed in the simulation is simply determined from the requirement of matching the desired fundamental frequency. The regularization of the dispersion curves by means of optimum unwarping is experimentally evaluated.

  10. An integrated chemo-enzymatic route for preparation of ß-thymidine, a key intermediate in the preparation of antiretrovirals

    CSIR Research Space (South Africa)

    Gordon, GER

    2011-01-01

    Full Text Available A chemo-enzymatic method for production of ß-thymidine, an intermediate in the synthesis of antiretrovirals, is described. Guanosine and thymine were converted by means of enzymatic transglycosylation to yield 5-methyluridine (5-MU), which...

  11. A STUDY OF THE SYNTHESIS OF VERATRYL CYANIDE REQUIRED AS AN INTERMEDIATE FOR THE PREPARATION OF C-9154 ANTIBIOTIC DERIVATIVE FROM VANILIN

    Directory of Open Access Journals (Sweden)

    Ila Rosilawati

    2010-06-01

    Full Text Available The synthesis of veratryl cyanide [1-(3,4-dimethoxy phenyl acetonitril] required as an intermediate for the preparation of C-9154 antibiotic derivative was carried out. The starting material used was vanilin, while the reaction steps consisted of (1 methylation of vanilin, (2 reduction of veratraldehyde, (3 synthesis of veratryl bromide, and (4 treatment of this bromide with KCN. The analysis of the products was carried out using IR, 1H NMR and GC-MS spectrophotometers.             The methylation of vanilin was conducted using dimethylsulfate and NaOH at 100  oC for 2 hours to give 79.3% yield of veratraldehyde. The reduction of veratraldehyde with LiBH4 in ethanol - THF mixture (1:1 v/v at reflux for 4 hours afforded veratryl alcohol in 85.3% yield. This veratryl alcohol was treated with red phosphorous and Br2 in CCl4 at 60 oC for 2 hours to give 1-(2-bromo-4,5-dimethoxy-phenyl bromomethane in 67.4% yield, instead of the desired veratryl bromide [1-3,4-dimethoxy-phenyl bromomethane]. This benzyl bromide derivative was then treated with KCN in the presence of tween 80 as a phase catalyst transsfer in benzene-water solvent system at reflux for 2 hours to yield 1-(2-bromo-4,5-dimethoxyphenyl acetonitril in 58.5%.   Keywords: Vanilin, veratryl cyanide, C-9154 antibiotic derivative

  12. In vitro synthesis of a lipid-linked trisaccharide involved in synthesis of enterobacterial common antigen

    International Nuclear Information System (INIS)

    Barr, K.; Nunes-Edwards, P.; Rick, P.D.

    1989-01-01

    The heteropolysaccharide chains of enterobacterial common antigen (ECA) are made up of linear trisaccharide repeat units with the structure----3)-alpha-D-Fuc4NAc-(1----4)- beta-D-ManNAcA-(1----4)-alpha-D-GlcNAc-(1----, where Fuc4NAc is 4-acetamido-4,6-dideoxy-D-galactose, ManNAcA is N-acetyl-D-mannosaminuronic acid, and GlcNAc is N-acetyl-D-glucosamine. The assembly of these chains involves lipid-linked intermediates, and both GlcNAc-pyrophosphorylundecaprenol (lipid I) and ManNAcA-GlcNAc-pyrophosphorylundecaprenol (lipid II) are intermediates in ECA biosynthesis. In this study we demonstrated that lipid II serves as the acceptor of Fuc4NAc residues in the assembly of the trisaccharide repeat unit of ECA chains. Incubation of Escherichia coli membranes with UDP-GlcNAc, UDP-[14C]ManNAcA, and TDP-[3H]Fuc4NAc resulted in the synthesis of a radioactive glycolipid (lipid III) that contained both [14C]ManNAcA and [3H]Fuc4NAc. The oligosaccharide moiety of lipid III was identified as a trisaccharide by gel-permeation chromatography, and the in vitro synthesis of lipid III was dependent on prior synthesis of lipids I and II. Accordingly, the incorporation of [3H]Fuc4NAc into lipid III from the donor TDP-[3H]Fuc4NAc was dependent on the presence of both UDP-GlcNAc and UDP-ManNAcA in the reaction mixtures. In addition, the in vitro synthesis of lipid III was abolished by tunicamycin. Direct conversion of lipid II to lipid III was demonstrated in two-stage reactions in which membranes were initially incubated with UDP-GlcNAc and UDP-[14C]ManNAcA to allow the synthesis of radioactive lipid II

  13. Synthesis of γ-Valerolactone from Carbohydrates and its Applications.

    Science.gov (United States)

    Zhang, Zehui

    2016-01-01

    γ-Valerolactone (GVL) is a valuable chemical intermediate that can be obtained by catalytic reduction of levulinic acid (LA) or alkyl levulinates (AL). There are many reports on the synthesis of GVL from LA or AL. However, the demand for the large-scale synthesis of GVL requires more environmentally friendly and cost-effective production processes. This article focuses on the recent advance in the synthesis of GVL from carbohydrates or lignocellulosic biomass. In addition, application of GVL as the reaction solvents, fuel additives, and as precursor for the synthesis of jet fuel and polymer monomers is also discussed. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. A brief review on synthesis & applications of β-enamino carbonyl compounds

    Directory of Open Access Journals (Sweden)

    yellajyosula L N Murthy

    2012-01-01

    Full Text Available Owing to the wide range applications of β-enamino esters (enamines of β–dicarbonyl compounds in pharmaceuticals and as building blocks for the synthesis of a variety of heterocyclic compounds, β-amino esters, β-amino acids, γ-amino alcohols, peptides and alkaloids a number of methods have been developed so far for the synthesis of these compounds. Due to the importance of these compounds as intermediates in organic synthesis, a concised review is presented.

  15. Synthesis of monoterpene piperidines from the iridoid glucoside antirrhinoside

    DEFF Research Database (Denmark)

    Franzyk, Henrik; Frederiksen, Signe Maria; Jensen, Søren Rosendal

    1997-01-01

    Synthesis of five novel piperidine monoterpene alkaloids using the iridoid glucoside antirrhinoside as a synthon is described. Two strategies for their preparation were investigated: the first possible pathway involved an intermediate diol from which the piperidine ring was expected to be constru......Synthesis of five novel piperidine monoterpene alkaloids using the iridoid glucoside antirrhinoside as a synthon is described. Two strategies for their preparation were investigated: the first possible pathway involved an intermediate diol from which the piperidine ring was expected...... to be constructed via reaction of its ditosylate with an amine; the second strategy involved a double reductive amination as the key step to the piperidine ring, which proved successful. The stereochemistry of C-5 and C-9 in the obtained piperidine monoterpenes was the same as that reported for alfa...

  16. Project study for the final disposal of intermediate toxicity radioactive wastes (low- and intermediate-level radioactive wastes) in geological formations

    International Nuclear Information System (INIS)

    1980-08-01

    The present report aimed to show variations in the construction- and operation-technical feasibility of a final repository for low- and intermediate-level radioactive wastes. This report represents the summary of a project study given under contract by Nagra with a view to informing a broader public of the technical conception of a final repository. Particular stress was laid on the treatment of the individual system elements of a repository concept during the construction, operation and sealing phases. The essential basis for the project study is the origin, composition and quantity of the wastes to be disposed. The final repository described in this report is foreseen for the reception of the following low- and intermediate-level solid radioactive wastes: wastes from the nuclear power plant operation; secondary wastes from the reprocessing of nuclear fuels; wastes from the decommissioning of nuclear power plants; wastes from research, medicine and industry

  17. Pharmaceutical supply chain models: A synthesis from a systems view of operations research

    Directory of Open Access Journals (Sweden)

    Ettore Settanni

    Full Text Available This research evaluates reconfiguration opportunities in Pharmaceutical Supply Chains (PSC resulting from technology interventions in manufacturing, and new, more patient-centric delivery models. A critical synthesis of the academic and practice literature is used to identify, conceptualise, analyse and categorise PSC models. From a theoretical perspective, a systems view of operations research is adopted to provide insights on a broader range of OR activities, from conceptual to mathematical modelling and model solving, up to implementation.The research demonstrates that: 1 current definitions of the PSC are largely production-centric and fail to capture patient consumption, and hence healthcare outcomes; 2 most PSC mathematical models lack adequate conceptualisation of the structure and behaviour of the supply chain, and the boundary conditions that need to be considered for a given problem; 3 models do not adequately specify current unit operations or future production technology options, and are therefore unable to address the critical questions around alternative product or process technologies; 4 economic evaluations are limited to direct costing, rather than systemic approaches such as supply chain costing and total cost of ownership.While current models of the PSC may help with the optimisation of specific unit operations, their theoretical benefits could be offset by the dynamics of complex upstream (supply and downstream (distribution and healthcare delivery systems. To overcome these limitations, this research provides initial directions towards an integrated systems approach to PSC modelling. This perspective involves problem conceptualisation and boundary definition; design, formulation and solution of mathematical models, through to practical implementation of identified solutions. For both academics and practitioners, research findings suggest a systems approach to PSC modelling can provide improved conceptualisation and

  18. Transport code and nuclear data in intermediate energy region

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Akira; Odama, Naomitsu [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Maekawa, F.; Ueki, K.; Kosaka, K.; Oyama, Y.

    1998-11-01

    We briefly reviewed the problems of intermediate energy nuclear data file and transport codes in connection with processing of the data. This is a summary of our group in the task force on JENDL High Energy File Integral Evaluation (JHEFIE). In this article we stress the necessity of the production of intermediate evaluated nuclear data file up to 3 GeV for the application of accelerator driven transmutation (ADT) system. And also we state the necessity of having our own transport code system to calculate the radiation fields using these evaluated files from the strategic points of view to keep our development of the ADT technology completely free from other conditions outside of our own such as imported codes and data with poor maintenance or unknown accuracy. (author)

  19. Transport code and nuclear data in intermediate energy region

    International Nuclear Information System (INIS)

    Hasegawa, Akira; Odama, Naomitsu; Maekawa, F.; Ueki, K.; Kosaka, K.; Oyama, Y.

    1998-01-01

    We briefly reviewed the problems of intermediate energy nuclear data file and transport codes in connection with processing of the data. This is a summary of our group in the task force on JENDL High Energy File Integral Evaluation (JHEFIE). In this article we stress the necessity of the production of intermediate evaluated nuclear data file up to 3 GeV for the application of accelerator driven transmutation (ADT) system. And also we state the necessity of having our own transport code system to calculate the radiation fields using these evaluated files from the strategic points of view to keep our development of the ADT technology completely free from other conditions outside of our own such as imported codes and data with poor maintenance or unknown accuracy. (author)

  20. Findings from the 2013 NZCER Primary and Intermediate Schools National Survey

    Science.gov (United States)

    New Zealand Council for Educational Research, 2014

    2014-01-01

    The New Zealand Council for Educational Research (NZCER) primary and intermediate schools national survey was carried out in July-August 2013. NZCER questioned principals, teachers and trustees at a representative sample of schools, and sought the views of a random sample of 1 in 4 parents in 36 of these schools. In all, the survey gathered data…

  1. SYNTHESIS OF METHACRYLATES FROM COAL-DERIVED SYNGAS

    Energy Technology Data Exchange (ETDEWEB)

    Jang, B.W.L.; Spivey, J.J.; Gogate, M.R.; Zoeller, J.R.; Colberg, R.D.; Choi, G.N.

    1999-12-01

    Research Triangle Institute (RTI), Eastman Chemical Company, and Bechtel have developed a novel process for synthesis of methyl methacrylate (MMA) from coal-derived syngas, under a contract from the US Department of Energy/Fossil Energy Technology Center (DOE/FETC). This project has resulted in five US patents (four already published and one pending publication). It has served as the basis for the technical and economic assessment of the production of this high-volume intermediate from coal-derived synthesis gas. The three-step process consists of the synthesis of a propionate from ethylene carbonylation using coal-derived CO, condensation of the propionate with formaldehyde to form methacrylic acid (MAA); and esterification of MAA with methanol to yield MMA. The first two steps, propionate synthesis and condensation catalysis, are the key technical challenges and the focus of the research presented here.

  2. Visual dictionaries as intermediate features in the human brain

    Directory of Open Access Journals (Sweden)

    Kandan eRamakrishnan

    2015-01-01

    Full Text Available The human visual system is assumed to transform low level visual features to object and scene representations via features of intermediate complexity. How the brain computationally represents intermediate features is still unclear. To further elucidate this, we compared the biologically plausible HMAX model and Bag of Words (BoW model from computer vision. Both these computational models use visual dictionaries, candidate features of intermediate complexity, to represent visual scenes, and the models have been proven effective in automatic object and scene recognition. These models however differ in the computation of visual dictionaries and pooling techniques. We investigated where in the brain and to what extent human fMRI responses to short video can be accounted for by multiple hierarchical levels of the HMAX and BoW models. Brain activity of 20 subjects obtained while viewing a short video clip was analyzed voxel-wise using a distance-based variation partitioning method. Results revealed that both HMAX and BoW explain a significant amount of brain activity in early visual regions V1, V2 and V3. However BoW exhibits more consistency across subjects in accounting for brain activity compared to HMAX. Furthermore, visual dictionary representations by HMAX and BoW explain significantly some brain activity in higher areas which are believed to process intermediate features. Overall our results indicate that, although both HMAX and BoW account for activity in the human visual system, the BoW seems to more faithfully represent neural responses in low and intermediate level visual areas of the brain.

  3. Synthesis of polynorbornene with pendant moiety bearing azide and terminal alkyne groups

    Institute of Scientific and Technical Information of China (English)

    Ze Zhang; Zhi Wei Peng; Kun Zeng Fan

    2011-01-01

    A powerful approach to the synthesis of an unprecedented polynorbornene with pendant moiety bearing azide and terminal alkyne groups is developed. Two key intermediates, namely, 3-azido-5-(2-(trimethylsilyl)ethynyl) benzyl alcohol and 4-(4-aza-tricyclo [5.2.1.02.6]dec-8-en-4-yl) benzoic acid, were optimally synthesized for convergent synthesis of the corresponding monomer.

  4. A formal synthesis of (+-muricatacin from D-xylose

    Directory of Open Access Journals (Sweden)

    VELIMIR POPSAVIN

    2003-11-01

    Full Text Available A multistep route towards the aldehydo-lactone 19, the final chiral precursor in a new stereospecific synthesis of (+-muricatacin, has been developed starting from D-xylose. The key step of the synthesis involves an E-selective Wittig olefination of the lactol 6 with methoxycarbonylmethylidene triphenylphosphorane, followed by successive catalytic reduction and g-lactonisation processes. Subsequent selective functional groups interconversions furnished the key six-carbon intermediate 19, which can be converted into the (+-muricatacin via a three-step sequence already described in the chemical literature.

  5. Synthesis of Α-azido-oximes from chiral cyclo-hexanones. Conformation monitoring by NMR

    International Nuclear Information System (INIS)

    Alves, R.J.; Fontes Prado, M.A.; Oliveira, A.B. de; Souza Filho, J.D. de; GArcia, J.I.; Olesker, A.; Lukacs, G.

    1993-01-01

    Carbon hydrates are the greatest source of chirality due to a large number of functional groups. Such compounds present preferential conformations, which result in reactions which high level of stereo-selectivity. This work is concerned to the preparation of intermediates to several other synthesis of biological interest and how the above mentioned properties influence these synthesis

  6. Green synthesis of chalcones derivatives as intermediate of flavones and their antibacterial activities

    Energy Technology Data Exchange (ETDEWEB)

    VH, Elfi Susanti, E-mail: elsantivh@yahoo.com; Redjeki, Tri, E-mail: tri-redjeki@yahoo.com [Universitas Sebelas Maret, Ir Sutami 36A Surakarta Indonesia, 57126 (Indonesia); Matsjeh, Sabirin, E-mail: sabirin-mara@yahoo.com; Wahyuningsih, Tutik Dwi, E-mail: mustofajogya@yahoo.co.id [Department of Chemistry FMJPA Universitas Gadjah Mada, Jl Sekip Utara, Yogyakarta Indonesia 55281 (Indonesia); Mustofa, E-mail: tutikdw@hotmail.com [Faculty of Medicine, Universitas Gadjah Mada, Yogyakarta Jl. Sekip Utara Yogyakarta Indonesia, 55281 (Indonesia)

    2016-02-08

    Four chalcones derivatives have been synthesized from 3,4-dimethoxybenzaldehyde and acetophenone derivatives (2-hydroxy acetophenone, 2,4-dihydroxy acetophenone, 2,5-dihydroxy acetophenone and 2,6-dihydroxy acetophenone). The synthesis of these chalcones were conducted by Claisen-Schmidt condensation using grinding techniques at room temperature in the absence of solvents. The chalcones were prepared by grinding together equivalent amount of the approriate hydroxyacetophenone and 3,4-dimethoxybenzaldehyde in the presence of solid sodium hydroxide. Grinding techniques for synthesis of the chalcones derivatives is simple, efficient and environmentally benign compared to conventional methods. Then, the four chalcones derivatives undergo cyclization reactions to produce four flavones after reacted with iodine. The synthesized compounds were characterized by spectrometry (IR, {sup 1}H-NMR, {sup 13}C-NMR and MS)

  7. Fluorous Parallel Synthesis of A Hydantoin/Thiohydantoin Library

    Science.gov (United States)

    Lu, Yimin; Zhang, Wei

    2007-01-01

    Fluorous tagging strategy is applied to solution-phase parallel synthesis of a library containing hydantoin and thiohydantoin analogs. Two perfluoroalkyl (Rf)-tagged α-amino esters each react with 6 aromatic aldehydes under reductive amination conditions. Twelve amino esters then each react with 10 isocyanates and isothiocyanates in parallel. The resulting 120 ureas and thioureas undergo spontaneous cyclization to form the corresponding hydantoins and thiohydantoins. The intermediate and final product purifications are performed with solid-phase extraction (SPE) over FluoroFlash™ cartridges, no chromatography is required. Using standard instruments and straightforward SPE technique, one chemist accomplished the 120-member library synthesis in less than 5 working days, including starting material synthesis and product analysis. PMID:15789556

  8. Synthesis of RP 48497, an Impurity of Eszopiclone

    Directory of Open Access Journals (Sweden)

    Mao-Sheng Cheng

    2008-08-01

    Full Text Available Abstract: RP 48497 is a photodegradation product of eszopiclone, a non-benzodiazepine sedative-hypnotic used in the treatment of insomnia. We report herein the first synthesis of RP 48497 via reduction, chlorination, and recyclization of 6-(5-chloropyridin-2-yl-7-hydroxy-6,7-dihydropyrrolo[3,4-b]pyrazin-5-one (3, a key intermediate in the synthesis of eszopiclone. The structure of RP 48497 was confirmed by its 1H-NMR and MS data. The mechanism of the reduction step in the synthesis of RP 48497 was also studied and the key parameters were determined. These findings should be important for quality control purposes in the manufacture of eszopiclone.

  9. On-Surface Synthesis by Click Chemistry Investigated by STM and XPS

    DEFF Research Database (Denmark)

    Vadapoo, Sundar Raja

    2014-01-01

    Molecular synthesis is essential in the bottom-up approach of achieving highly stable nanostructures. On-surface synthesis is highly interesting from the basic science of view to improve the understanding of molecular behavior adsorbed on metal surfaces, and has potential applications such as mol......Molecular synthesis is essential in the bottom-up approach of achieving highly stable nanostructures. On-surface synthesis is highly interesting from the basic science of view to improve the understanding of molecular behavior adsorbed on metal surfaces, and has potential applications...... such as molecular electronics and surface functionalization. In this thesis, a well-defined click chemistry approach is followed, with the study of azide-alkyne cycloaddition on Cu(111) surface in UHV environment. A successful achievement of the click reaction product via on-surface synthesis has been shown, which...

  10. Intermediate treatments

    Science.gov (United States)

    John R. Jones; Wayne D. Shepperd

    1985-01-01

    Intermediate treatments are those applied after a new stand is successfully established and before the final harvest. These include not only intermediate cuttings - primarily thinning - but also fertilization, irrigation, and protection of the stand from damaging agents.

  11. Selectivity switch in the synthesis of vinylgold(I) intermediates

    KAUST Repository

    Hashmi, A. Stephen K

    2011-11-28

    An unexpected regioselectivity reversal was observed in the synthesis of vinylgold(I) complexes from propargyl carboxamides. The use of [Au(IPr)(OH)] affords preferentially vinylgold(I) complexes resulting from a 5-exo-dig cyclization, whereas the use [Au(IPr)]+ species, generated in situ starting from [Au(IPr)(Cl)] and AgOTf, leads to vinylgold(I) complexes which form via a 6-endo-dig cyclization, This unexpected "selectivity switch" for this cyclization led us to propose two different reaction pathways enabling the formation of the two different products. One mechanism involves the [Au(IPr)]+ species with "classical" I activation of the alkyne framework of the carboxamides, and the second represents an "unusual" use of the basic Brønsted character of [Au(IPr)(OH)]. Mechanistic and DFT studies support the mechanistic hypotheses. © 2011 American Chemical Society.

  12. Selectivity switch in the synthesis of vinylgold(I) intermediates

    KAUST Repository

    Hashmi, A. Stephen K; Schuster, Andreas M.; Gaillard, Sylvain; Cavallo, Luigi; Poater, Albert; Nolan, Steven P.

    2011-01-01

    An unexpected regioselectivity reversal was observed in the synthesis of vinylgold(I) complexes from propargyl carboxamides. The use of [Au(IPr)(OH)] affords preferentially vinylgold(I) complexes resulting from a 5-exo-dig cyclization, whereas the use [Au(IPr)]+ species, generated in situ starting from [Au(IPr)(Cl)] and AgOTf, leads to vinylgold(I) complexes which form via a 6-endo-dig cyclization, This unexpected "selectivity switch" for this cyclization led us to propose two different reaction pathways enabling the formation of the two different products. One mechanism involves the [Au(IPr)]+ species with "classical" I activation of the alkyne framework of the carboxamides, and the second represents an "unusual" use of the basic Brønsted character of [Au(IPr)(OH)]. Mechanistic and DFT studies support the mechanistic hypotheses. © 2011 American Chemical Society.

  13. Facile Synthesis of Monodispersed Polysulfide Spheres for Building Structural Colors with High Color Visibility and Broad Viewing Angle.

    Science.gov (United States)

    Li, Feihu; Tang, Bingtao; Wu, Suli; Zhang, Shufen

    2017-01-01

    The synthesis and assembly of monodispersed colloidal spheres are currently the subject of extensive investigation to fabricate artificial structural color materials. However, artificial structural colors from general colloidal crystals still suffer from the low color visibility and strong viewing angle dependence which seriously hinder their practical application in paints, colorimetric sensors, and color displays. Herein, monodispersed polysulfide (PSF) spheres with intrinsic high refractive index (as high as 1.858) and light-absorbing characteristics are designed, synthesized through a facile polycondensation and crosslinking process between sodium disulfide and 1,2,3-trichloropropane. Owing to their high monodispersity, sufficient surface charge, and good dispersion stability, the PSF spheres can be assembled into large-scale and high-quality 3D photonic crystals. More importantly, high structural color visibility and broad viewing angle are easily achieved because the unique features of PSF can remarkably enhance the relative reflectivity and eliminate the disturbance of scattering and background light. The results of this study provide a simple and efficient strategy to create structural colors with high color visibility, which is very important for their practical application. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Synthesis of 2-phenylnaphthalenes from styryl-2-methoxybenzenes.

    Science.gov (United States)

    Mudududdla, Ramesh; Sharma, Rohit; Abbat, Sheenu; Bharatam, Prasad V; Vishwakarma, Ram A; Bharate, Sandip B

    2014-10-18

    A new simple and efficient method for the synthesis of 2-phenylnaphthalenes from electron-rich 1-styryl-2-methoxybenzenes has been described. The reaction proceeds via TFA catalyzed C-C bond cleavage followed by intermolecular [4+2]-Diels-Alder cycloaddition of an in situ formed styrenyl trifluoroacetate intermediate. The quantum chemical calculations identified the transition state for the cycloaddition reaction and helped in tracing the reaction mechanism. The method has been efficiently utilized for synthesis of the phenanthrene skeleton and a naphthalene-based potent and selective ER-β agonist.

  15. Organotrichlorogermane synthesis by the reaction of elemental germanium, tetrachlorogermane and organic chloride via dichlorogermylene intermediate.

    Science.gov (United States)

    Okamoto, Masaki; Asano, Takuya; Suzuki, Eiichi

    2004-08-07

    Organotrichlorogermanes were synthesized by the reaction of elemental germanium, tetrachlorogermane and organic chlorides, methyl, propyl, isopropyl and allyl chlorides. Dichlorogermylene formed by the reaction of elemental germanium with tetrachlorogermane was the reaction intermediate, which was inserted into the carbon-chlorine bond of the organic chloride to give organotrichlorogermane. When isopropyl or allyl chloride was used as an organic chloride, organotrichlorogermane was formed also in the absence of tetrachlorogermane. These chlorides were converted to hydrogen chloride, which subsequently reacted with elemental germanium to give the dichlorogermylene intermediate. The reaction of elemental germanium, tetrachlorogermane and organic chlorides provides a simple and easy method for synthesizing organotrichlorogermanes, and all the raw materials are easily available.

  16. Synthesis of 6-Phosphofructose Aspartic Acid and Some Related Amadori Compounds

    OpenAIRE

    Hansen, Alexandar L.; Behrman, Edward J.

    2016-01-01

    We describe the synthesis and characterization of 6-phosphofructose-aspartic acid, an intermediate in the metabolism of fructose-asparagine by Salmonella. We also report improved syntheses of fructose-asparagine itself and of fructose-aspartic acid.

  17. Ion-exchange-resin-catalyzed adamantylation of phenol derivatives with adamantanols: Developing a clean process for synthesis of 2-(1-adamantyl-4-bromophenol, a key intermediate of adapalene

    Directory of Open Access Journals (Sweden)

    Nan Wang

    2012-02-01

    Full Text Available A clean process has been developed for the synthesis of 2-adamantylphenol derivatives through adamantylation of substituted phenols with adamantanols catalyzed by commercially available and recyclable ion-exchange sulfonic acid resin in acetic acid. The sole byproduct of the adamantylation reaction, namely water, could be converted into the solvent acetic acid by addition of a slight excess of acetic anhydride during the work-up procedure, making the process waste-free except for regeneration of the ion-exchange resin, and facilitating the recycling of the resin catalyst. The ion-exchange sulfonic acid resin catalyst could be readily recycled by filtration and directly reused at least ten times without a significant loss of activity. The key intermediate of adapalene, 2-(1-adamantyl-4-bromophenol, could be produced by means of this waste-free process.

  18. Synthesis of 2,3-Disubstituted Quinolines via Ketenimine or Carbodiimide Intermediates.

    Science.gov (United States)

    Zhao, Hongyang; Xing, Yanpeng; Lu, Ping; Wang, Yanguang

    2016-10-10

    Cyclopenta[b]quinolines and cyclohexa[b]quinolines were prepared via the reactions of α-diazo ketones with N-(2-cyclopropylidenemethylphenyl)phosphanimines and N-(2-cyclobutylidenemethylphenyl) phosphanimine, respectively. The reaction proceeds in a cascade involving ketenimine formation, 6 π-electron ring closure, and 1,3-alkyl shift. A similar approach was developed for the synthesis of dihydropyrrolo-[2,3-b]quinolines from N-(2-cyclopropylidenemethylphenyl)phosphanimines and isocyanates. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Iridium-Catalyzed Dynamic Kinetic Isomerization: Expedient Synthesis of Carbohydrates from Achmatowicz Rearrangement Products.

    Science.gov (United States)

    Wang, Hao-Yuan; Yang, Ka; Bennett, Scott R; Guo, Sheng-rong; Tang, Weiping

    2015-07-20

    A highly stereoselective dynamic kinetic isomerization of Achmatowicz rearrangement products was discovered. This new internal redox isomerization provided ready access to key intermediates for the enantio- and diastereoselective synthesis of a series of naturally occurring sugars. The nature of the de novo synthesis also enables the preparation of both enantiomers. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Enantioselective Synthesis of (-)-Vallesine: Late-Stage C17-Oxidation via Complex Indole Boronation.

    Science.gov (United States)

    Antropow, Alyssa H; Garcia, Nicholas R; White, Kolby L; Movassaghi, Mohammad

    2018-06-04

    The first enantioselective total synthesis of (-)-vallesine via a strategy that features a late-stage regioselective C17-oxidation followed by a highly stereoselective transannular cyclization is reported. The versatility of this approach is highlighted by the divergent synthesis of the archetypal alkaloid of this family, (+)-aspidospermidine, and an A-ring-oxygenated derivative, (+)-deacetylaspidospermine, the precursor to (-)-vallesine, from a common intermediate.

  1. De novo synthesis of adenine nucleotides in different skeletal muscle fiber types

    International Nuclear Information System (INIS)

    Tullson, P.C.; John-Alder, H.B.; Hood, D.A.; Terjung, R.L.

    1988-01-01

    Management of adenine nucleotide catabolism differs among skeletal muscle fiber types. This study evaluated whether there are corresponding differences in the rates of de novo synthesis of adenine nucleotide among fiber type sections of skeletal muscle using an isolated perfused rat hindquarter preparation. Label incorporation into adenine nucleotides from the [1-14C]glycine precursor was determined and used to calculate synthesis rates based on the intracellular glycine specific radioactivity. Results show that intracellular glycine is closely related to the direct precursor pool. Rates of de novo synthesis were highest in fast-twitch red muscle (57.0 +/- 4.0, 58.2 +/- 4.4 nmol.h-1.g-1; deep red gastrocnemius and vastus lateralis), relatively high in slow-twitch red muscle (47.0 +/- 3.1; soleus), and low in fast-twitch white muscle (26.1 +/- 2.0 and 21.6 +/- 2.3; superficial white gastrocnemius and vastus lateralis). Rates for four mixed muscles were intermediate, ranging between 32.3 and 37.3. Specific de novo synthesis rates exhibited a strong correlation (r = 0.986) with muscle section citrate synthase activity. Turnover rates (de novo synthesis rate/adenine nucleotide pool size) were highest in high oxidative muscle (0.82-1.06%/h), lowest in low oxidative muscle (0.30-0.35%/h), and intermediate in mixed muscle (0.44-0.55%/h). Our results demonstrate that differences in adenine nucleotide management among fiber types extends to the process of de novo adenine nucleotide synthesis

  2. Kinetics of the ammonia synthesis at low temperatures. II. Sources of discrepancies

    International Nuclear Information System (INIS)

    Kuchaev, V.L.; Shapatina, E.N.; Temkin, M.I.

    1988-01-01

    A method is developed for calculating the degree of conversion during the synthesis of ammonia in a continuous flow, tubular reactor, taking longitudinal diffusion into account. Such a calculation shows that the available data in the literature on the rate of ammonia synthesis at low temperatures in a tubular reactor agree with the rate equation based on the idea that the predominant intermediate substance is adsorbed ammonia (and not imide). The seeming conflict between this idea and the ratio of the rates of synthesis of ammonia and deuteroammonia at low temperatures is explained

  3. An Efficient Synthesis of Enantiopure (R-heteroarylpyrimidine Analogs

    Directory of Open Access Journals (Sweden)

    Guo-Ming Zhao

    2013-09-01

    Full Text Available An efficient synthesis of enantiopure (R-heteroarylpyrimidine analogs is described here, which involves introduction of a chiral group, formation and separation of diasteroisomers and final transformation of an amide to an ester. The absolute configuration of the enantiopure HAPs is confirmed by X-ray analysis of their intermediates.

  4. Some peculiarities of zirconium tungstate synthesis by thermal decomposition of hydrothermal precursors

    International Nuclear Information System (INIS)

    Gubanov, Alexander I.; Dedova, Elena S.; Plyusnin, Pavel E.; Filatov, Eugeny Y.; Kardash, Tatyana Y.; Korenev, Sergey V.; Kulkov, Sergey N.

    2014-01-01

    Highlights: • Synthesis of ZrW 2 O 8 using hydrothermal method. • On hydrothermal synthesis optimal conc. of HCl in the reaction mixture is 2.3 M. • Thermal decomposition of ZrW 2 O 7 ((OH) 1.5 ,Cl 0.5 )·2H 2 O begins are 200 °S. • Amorphous intermediate crystallizes into cubic single-phase ZrW 2 O 8 above 550 °S. • ZrW 2 O 8 destructed at temperatures above 700 °S. - Abstract: This article discusses some peculiarities of the synthesis of ZrW 2 O 8 (1) using thermal decomposition of the precursor ZrW 2 O 7 ((OH) 1.5 ,Cl 0.5 )·2H 2 O (2) prepared by hydrothermal method. On hydrothermal synthesis of 2 the optimal concentration of hydrochloric acid in the reaction mixture is about 2.3 M. TG approach to determine the chemical composition of the precursor was suggested. It has been found that the precursor for the synthesis of zirconium tungstate has chemical formula 2. Thermal decomposition of the precursor 2 begins at 200 °S and affords an amorphous intermediate, which crystallizes as a cubic phase 1 above 550 °S with an exoeffect. The temperature of the beginning of the transition from amorphous to the crystalline state is 350 ± 25 °S

  5. Synthesis and structure of the unligated carbene of chromium

    Energy Technology Data Exchange (ETDEWEB)

    Billups, W.E.; Souchan Chang; Hauge, R.H.; Margrave, J.L. (Rice Univ., Houston, TX (United States))

    1993-04-14

    Complexes with metal-carbon double bonds have found applications as intermediates in many important catalytic reactions including cyclopropanation of alkenes by diazoalkanes, Fischer-Tropsch synthesis, olefin metathesis, Ziegler-Natta polymerization, alkane activation, and in the decomposition of transition metal alkyl complexes. However, complexes with the simplest carbene, CH[sub 2], coordinated to the metal center are relatively rare. In this paper the authors report the synthesis and characterization of the simple unligated carbene of chromium by FTIR matrix isolation spectroscopy. 7 refs., 3 figs., 4 tabs.

  6. A Base Promoted Synthesis of N,N-dimethylformamidines

    International Nuclear Information System (INIS)

    Li, Bao Lin; Ding, Si Yi; Ren, Yu Fei; Wang, Liu Chang; Jia, Yu Cai; Zhang, Xi Quan; Gu, Hong Mei

    2013-01-01

    In conclusion, this report supplies a base promoted synthesis of N'-aryl-N,N-dimethylformamidines straight from arylamines bearing strong electron withdrawing group at o-position and imine complex from DMF and Me 2 SO 4 . The key advantage of the procedure is to avoid the preparation of N,N-dimethylformamide dimethyl acetal from DMF and Me 2 SO 4 . Using this method, some important intermediates shown as entry 1-4, 9-11 in Table 3 were efficiently prepared. With these intermediates in hand, various antitumor drugs containing quinazoline moiety such as gefitinib, erlotinib and lapatinib etc. can be synthesized conveniently

  7. One-pot synthesis of amides by aerobic oxidative coupling of alcohols or aldehydes with amines using supported gold and base as catalysts

    DEFF Research Database (Denmark)

    Kegnæs, Søren; Mielby, Jerrik Jørgen; Mentzel, Uffe Vie

    2012-01-01

    Synthesis of amides by aerobic oxidative coupling of alcohols or aldehydes with amines via intermediate formation of methyl esters is highly efficient and selective when using a catalytic system comprised of supported gold nanoparticles and added base in methanol.......Synthesis of amides by aerobic oxidative coupling of alcohols or aldehydes with amines via intermediate formation of methyl esters is highly efficient and selective when using a catalytic system comprised of supported gold nanoparticles and added base in methanol....

  8. Intermediate phases in the formation of the Cu-Ba-Y high-Tc superconductor from xerogel

    International Nuclear Information System (INIS)

    Arcon, I.; Bele, M.; Hribar, M.; Kodre, A.; Stuhec, M.; Pejovnik, S.; Frahm, R.

    1995-01-01

    In the synthesis of YBa 2 Cu 3 O 7-x superconductor ceramics by the sol-gel method, yttrium K EXAFS spectra of the intermediate products give evidence of the dynamics of the Y ion in the reaction. Together with previous data on Cu K and Ba L 3 EXAFS, the results give information on the processes in the amorphous phase, complementing the diffraction data on crystallite growth. ((orig.))

  9. Synthesis of peptide .alpha.-thioesters

    Science.gov (United States)

    Camarero, Julio A [Livermore, CA; Mitchell, Alexander R [Livermore, CA; De Yoreo, James J [Clayton, CA

    2008-08-19

    Disclosed herein is a new method for the solid phase peptide synthesis (SPPS) of C-terminal peptide .alpha. thioesters using Fmoc/t-Bu chemistry. This method is based on the use of an aryl hydrazine linker, which is totally stable to conditions required for Fmoc-SPPS. When the peptide synthesis has been completed, activation of the linker is achieved by mild oxidation. The oxidation step converts the acyl-hydrazine group into a highly reactive acyl-diazene intermediate which reacts with an .alpha.-amino acid alkylthioester (H-AA-SR) to yield the corresponding peptide .alpha.-thioester in good yield. A variety of peptide thioesters, cyclic peptides and a fully functional Src homology 3 (SH3) protein domain have been successfully prepared.

  10. A statistical view of protein chemical synthesis using NCL and extended methodologies.

    Science.gov (United States)

    Agouridas, Vangelis; El Mahdi, Ouafâa; Cargoët, Marine; Melnyk, Oleg

    2017-09-15

    Native chemical ligation and extended methodologies are the most popular chemoselective reactions for protein chemical synthesis. Their combination with desulfurization techniques can give access to small or challenging proteins that are exploited in a large variety of research areas. In this report, we have conducted a statistical review of their use for protein chemical synthesis in order to provide a flavor of the recent trends and identify the most popular chemical tools used by protein chemists. To this end, a protein chemical synthesis (PCS) database (http://pcs-db.fr) was created by collecting a set of relevant data from more than 450 publications covering the period 1994-2017. A preliminary account of what this database tells us is presented in this report. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Deep Learning in Intermediate Microeconomics: Using Scaffolding Assignments to Teach Theory and Promote Transfer

    Science.gov (United States)

    Green, Gareth P.; Bean, John C.; Peterson, Dean J.

    2013-01-01

    Intermediate microeconomics is typically viewed as a theory and tools course that relies on algorithmic problems to help students learn and apply economic theory. However, the authors' assessment research suggests that algorithmic problems by themselves do not encourage students to think about where the theory comes from, why the theory is…

  12. Probing in-medium spin–orbit interaction with intermediate-energy heavy-ion collisions

    International Nuclear Information System (INIS)

    Xu, Jun; Li, Bao-An

    2013-01-01

    Incorporating for the first time both the spin and isospin degrees of freedom explicitly in transport model simulations of intermediate-energy heavy-ion collisions, we observe that a local spin polarization appears during collision process. Most interestingly, it is found that the nucleon spin up–down differential transverse flow is a sensitive probe of the spin–orbit interaction, providing a novel approach to probe both the density and isospin dependence of the in-medium spin–orbit coupling that is important for understanding the structure of rare isotopes and synthesis of superheavy elements

  13. Intermediate transport in Southeast Asia. [Carts, cycles, mini-buses

    Energy Technology Data Exchange (ETDEWEB)

    Meier, A.K.

    1977-06-01

    Traffic flows through the streets of Southeast Asian countries even though they are used for almost all aspects of human and animal existence. The carts, bicycles, tricycles, and motorcycles, motorized three-wheelers, mini-buses are the so-called intermediate-transport vehicles. It is upon this group of vehicles that a culture--constrained by its own unique economic, environmental, and technological factors--exerts its influence most directly toward the solution of the transport problem. Transportation fills more service roles in Southeast Asian cities than in Western cities. Communication facilities such as telephones and postal services are notoriously unreliable. The personal encounter is all important in social and business interactions in Southeast Asia. Each of the transport modes is examined in view of design and use in a number of specific cultural settings for the countries in Southeast Asia. Present use of intermediate transport in developed countries is discussed briefly, and its further development predicted--pointing out the health and conservation advantages. (MCW)

  14. Cholesterol synthesis by human fetal hepatocytes: effect of lipoproteins

    International Nuclear Information System (INIS)

    Carr, B.R.; Simpson, E.R.

    1984-01-01

    The purpose of the present investigation was to determine the effect of various lipoproteins on the rate of cholesterol synthesis of human fetal liver cells maintained in culture. This was accomplished by measuring the rate of incorporation of tritium from tritiated water or carbon 14-labeled acetate into cholesterol in human fetal liver cells. Optimal conditions for each assay were determined. When human fetal liver cells were maintained in the presence of low-density lipoprotein, cholesterol synthesis was inhibited in a concentration-dependent fashion. Intermediate--density lipoprotein and very-low-density lipoprotein also suppressed cholesterol synthesis in human fetal liver cells. In contrast, high-density lipoprotein stimulated cholesterol synthesis in human fetal liver cells. The results of the present as well as our previous investigations suggest that multiple interrelationships exist between fetal liver cholesterol synthesis and lipoprotein-cholesterol utilization by the human fetal adrenal gland and that these processes serve to regulate the lipoprotein-cholesterol levels in fetal plasma

  15. Streptomyces clavuligerus shows a strong association between TCA cycle intermediate accumulation and clavulanic acid biosynthesis.

    Science.gov (United States)

    Ramirez-Malule, Howard; Junne, Stefan; Nicolás Cruz-Bournazou, Mariano; Neubauer, Peter; Ríos-Estepa, Rigoberto

    2018-05-01

    Clavulanic acid (CA) is produced by Streptomyces clavuligerus (S. clavuligerus) as a secondary metabolite. Knowledge about the carbon flux distribution along the various routes that supply CA precursors would certainly provide insights about metabolic performance. In order to evaluate metabolic patterns and the possible accumulation of tricarboxylic acid (TCA) cycle intermediates during CA biosynthesis, batch and subsequent continuous cultures with steadily declining feed rates were performed with glycerol as the main substrate. The data were used to in silico explore the metabolic capabilities and the accumulation of metabolic intermediates in S. clavuligerus. While clavulanic acid accumulated at glycerol excess, it steadily decreased at declining dilution rates; CA synthesis stopped when glycerol became the limiting substrate. A strong association of succinate, oxaloacetate, malate, and acetate accumulation with CA production in S. clavuligerus was observed, and flux balance analysis (FBA) was used to describe the carbon flux distribution in the network. This combined experimental and numerical approach also identified bottlenecks during the synthesis of CA in a batch and subsequent continuous cultivation and demonstrated the importance of this type of methodologies for a more advanced understanding of metabolism; this potentially derives valuable insights for future successful metabolic engineering studies in S. clavuligerus.

  16. One-carbon 13C-labeled synthetic intermediates. Comparison and evaluation of preparative methods

    International Nuclear Information System (INIS)

    Ott, D.G.

    1978-01-01

    Frequently the biggest stumbling block to the synthesis of a structurally complex labeled compound is obtaining the required low molecular weight, structurally simple, isotopic intermediates. Selection of a particular scheme from various alternatives depends on the available capabilities and quantity of product desired, as well as on anticipated future requirements and need for related compounds. Many of the newer reagents for organic synthesis can be applied effectively to isotopic preparations with improvements of yields and simplification of procedures compared to established classical methods. New routes developed for higher molecular weight compounds are sometimes not directly adaptable to the one-carbon analogs, either because of isolation difficulties occasioned by physical properties or by chemical reactivities peculiar to their being first members of homologous series. Various routes for preparation of carbon-13 labeled methanol, formaldehyde, and cyanide are compared

  17. Rat intermediate lobe in culture: a histological and biochemical characterization.

    Science.gov (United States)

    Chronwall, B M; Bishop, J F; Gehlert, D R

    1988-01-01

    The histology, immunohistochemistry, peptide synthesis and secretion as well as proliferation rate of rat intermediate lobe (IL) were studied in primary cultures. The cultures contained two populations of cells: melanotrophs either organized in free floating lobules or in lobules which attached to the dishes and formed a monolayer. Both populations retained their in vivo morphology: polyhedral cells with smooth, ovoid nuclei and a large number of cytoplasmic secretory coated vesicles, a well developed Golgi apparatus, abundant mitochondria and extensive areas of rough endoplasmic reticulum. The melanotrophs stained with varying intensity for alpha-MSH and in situ hybridization showed the presence of pro-opiomelanocortin (POMC) mRNA. 35S-methionine incorporation combined with 2-D gel electrophoresis demonstrated POMC peptide synthesis and radioimmunoassay confirmed its secretion into the medium. 3H-thymidine uptake in the attached melanotrophs was considerably higher than that in the free-floating melanotrophs, demonstrating the dependency of proliferation rate on the cytoarchitecture of the explant. The retention of melanotroph morphology, biosynthetic and proliferative capacity in vitro affords a valid model system for studying POMC gene expression.

  18. Toleration, Synthesis or Replacement?

    DEFF Research Database (Denmark)

    Holtermann, Jakob v. H.; Madsen, Mikael Rask

    2016-01-01

    , in order to answer is not yet another partisan suggestion, but rather an attempt at making intelligible both the oppositions and the possibilities of synthesis between normative and empirical approaches to law. Based on our assessment and rational reconstruction of current arguments and positions, we...... therefore outline a taxonomy consisting of the following three basic, ideal-types in terms of the epistemological understanding of the interface of law and empirical studies: toleration, synthesis and replacement. This tripartite model proves useful with a view to teasing out and better articulating...

  19. Ammonia synthesis over a Ru(0001) surface studied by density functional calculations

    DEFF Research Database (Denmark)

    Logadottir, Ashildur; Nørskov, Jens Kehlet

    2003-01-01

    In this paper we present DFT studies of all the elementary steps in the synthesis of ammonia from gaseous hydrogen and nitrogen over a ruthenium crystal. The stability and configurations of intermediates in the ammonia synthesis over a Ru(0001) surface have been investigated, both over a flat...... surface and over a stepped surface. The calculations show that the step sites on the surface are much more reactive than the terrace sites. The DFT results are then used to study the mechanism of promotion by alkalies over the Ru(0001) and to determine the rate-determining step in the synthesis of ammonia...

  20. Facile Synthesis of Permethyl Yttrocene Hydride

    NARCIS (Netherlands)

    Haan, Klaas H. den; Teuben, Jan H.

    1984-01-01

    A convenient three step synthesis of (Cp*2YH)n (Cp* = C5Me5) is described starting with YCl3.3thf, in which Cp*2YCl.thf and Cp*2YCH(SiMe3)2 are intermediates, which could be isolated and characterized. The hydride is active in the activation of sp2 and sp3 C-H bonds as was demonstrated by the H-D

  1. Synthesis of chirals regioisomers from D-mannitol: obtainment of a acetylenic alcohols mixture

    International Nuclear Information System (INIS)

    Cito, Antonia Maria das Gracas Lopes; Araujo, Bruno Quirino; Lopes, Jose Arimateia Dantas; Magalhes, Aderbal Farias; Magalhes, Eva Goncalves

    2009-01-01

    The synthesis of chiral acetylenic regioisomers was described by using an appropriate intermediate such as isopropylidene glycerol, a synthon widely used in the enantioselective syntheses. This intermediate was prepared from D-mannitol. The nine obtained compounds have been characterized by their respective spectral data. The mixture of chiral acetylenic alcohols showed activity against Escherichia coli when tested through the monitoring of CO 2 released during microbial respiration by using a conductimetric system. (author)

  2. Some peculiarities of zirconium tungstate synthesis by thermal decomposition of hydrothermal precursors

    Energy Technology Data Exchange (ETDEWEB)

    Gubanov, Alexander I., E-mail: gubanov@niic.nsc.su [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Akad. Lavrentiev Prospekt 3, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, Pirogova str. 2, 630090 Novosibirsk (Russian Federation); Dedova, Elena S. [Institute of Strength Physics and Materials Science, Siberian Branch of the Russian Academy of Sciences, pr. Akademicheskii 2/4, 634021 Tomsk (Russian Federation); Tomsk Polytechnic University, Lenin Avenue 30, 634050 Tomsk (Russian Federation); Plyusnin, Pavel E.; Filatov, Eugeny Y. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Akad. Lavrentiev Prospekt 3, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, Pirogova str. 2, 630090 Novosibirsk (Russian Federation); Kardash, Tatyana Y. [Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Akad. Lavrentiev Prospekt 5, 630090 Novosibirsk (Russian Federation); Korenev, Sergey V. [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Akad. Lavrentiev Prospekt 3, 630090 Novosibirsk (Russian Federation); Novosibirsk State University, Pirogova str. 2, 630090 Novosibirsk (Russian Federation); Kulkov, Sergey N. [Institute of Strength Physics and Materials Science, Siberian Branch of the Russian Academy of Sciences, pr. Akademicheskii 2/4, 634021 Tomsk (Russian Federation); Tomsk Polytechnic University, Lenin Avenue 30, 634050 Tomsk (Russian Federation)

    2014-12-10

    Highlights: • Synthesis of ZrW{sub 2}O{sub 8} using hydrothermal method. • On hydrothermal synthesis optimal conc. of HCl in the reaction mixture is 2.3 M. • Thermal decomposition of ZrW{sub 2}O{sub 7}((OH){sub 1.5},Cl{sub 0.5})·2H{sub 2}O begins are 200 °S. • Amorphous intermediate crystallizes into cubic single-phase ZrW{sub 2}O{sub 8} above 550 °S. • ZrW{sub 2}O{sub 8} destructed at temperatures above 700 °S. - Abstract: This article discusses some peculiarities of the synthesis of ZrW{sub 2}O{sub 8} (1) using thermal decomposition of the precursor ZrW{sub 2}O{sub 7}((OH){sub 1.5},Cl{sub 0.5})·2H{sub 2}O (2) prepared by hydrothermal method. On hydrothermal synthesis of 2 the optimal concentration of hydrochloric acid in the reaction mixture is about 2.3 M. TG approach to determine the chemical composition of the precursor was suggested. It has been found that the precursor for the synthesis of zirconium tungstate has chemical formula 2. Thermal decomposition of the precursor 2 begins at 200 °S and affords an amorphous intermediate, which crystallizes as a cubic phase 1 above 550 °S with an exoeffect. The temperature of the beginning of the transition from amorphous to the crystalline state is 350 ± 25 °S.

  3. Theoretical modelling of intermediate band solar cell materials based on metal-doped chalcopyrite compounds

    International Nuclear Information System (INIS)

    Palacios, P.; Sanchez, K.; Conesa, J.C.; Fernandez, J.J.; Wahnon, P.

    2007-01-01

    Electronic structure calculations are carried out for CuGaS 2 partially substituted with Ti, V, Cr or Mn to ascertain if some of these systems could provide an intermediate band material able to give a high efficiency photovoltaic cell. Trends in electronic level positions are analyzed and more accurate advanced theory levels (exact exchange or Hubbard-type methods) are used in some cases. The Ti-substituted system seems more likely to yield an intermediate band material with the desired properties, and furthermore seems realizable from the thermodynamic point of view, while those with Cr and Mn might give half-metal structures with applications in spintronics

  4. Theoretical modelling of intermediate band solar cell materials based on metal-doped chalcopyrite compounds

    Energy Technology Data Exchange (ETDEWEB)

    Palacios, P [Instituto de Energia Solar and Dpt. de Tecnologias Especiales, ETSI de Telecomunicacion, UPM, Ciudad Universitaria s/n, 28040 Madrid (Spain); Sanchez, K [Instituto de Energia Solar and Dpt. de Tecnologias Especiales, ETSI de Telecomunicacion, UPM, Ciudad Universitaria s/n, 28040 Madrid (Spain); Conesa, J C [Instituto de Catalisis y Petroleoquimica, CSIC, Marie Curie 2, Cantoblanco, 28049 Madrid (Spain); Fernandez, J J [Dpt. de Fisica Fundamental, Universidad Nacional de Educacion a Distancia, 28080, Madrid (Spain); Wahnon, P [Instituto de Energia Solar and Dpt. de Tecnologias Especiales, ETSI de Telecomunicacion, UPM, Ciudad Universitaria s/n, 28040 Madrid (Spain)

    2007-05-31

    Electronic structure calculations are carried out for CuGaS{sub 2} partially substituted with Ti, V, Cr or Mn to ascertain if some of these systems could provide an intermediate band material able to give a high efficiency photovoltaic cell. Trends in electronic level positions are analyzed and more accurate advanced theory levels (exact exchange or Hubbard-type methods) are used in some cases. The Ti-substituted system seems more likely to yield an intermediate band material with the desired properties, and furthermore seems realizable from the thermodynamic point of view, while those with Cr and Mn might give half-metal structures with applications in spintronics.

  5. Synthesis of 6-phosphofructose aspartic acid and some related Amadori compounds.

    Science.gov (United States)

    Hansen, Alexandar L; Behrman, Edward J

    2016-08-05

    We describe the synthesis and characterization of 6-phosphofructose-aspartic acid, an intermediate in the metabolism of fructose-asparagine by Salmonella. We also report improved syntheses of fructose-asparagine itself and of fructose-aspartic acid. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Feature-aware natural texture synthesis

    KAUST Repository

    Wu, Fuzhang

    2014-12-04

    This article presents a framework for natural texture synthesis and processing. This framework is motivated by the observation that given examples captured in natural scene, texture synthesis addresses a critical problem, namely, that synthesis quality can be affected adversely if the texture elements in an example display spatially varied patterns, such as perspective distortion, the composition of different sub-textures, and variations in global color pattern as a result of complex illumination. This issue is common in natural textures and is a fundamental challenge for previously developed methods. Thus, we address it from a feature point of view and propose a feature-aware approach to synthesize natural textures. The synthesis process is guided by a feature map that represents the visual characteristics of the input texture. Moreover, we present a novel adaptive initialization algorithm that can effectively avoid the repeat and verbatim copying artifacts. Our approach improves texture synthesis in many images that cannot be handled effectively with traditional technologies.

  7. Intermediate neutron spectrum problems and the intermediate neutron spectrum experiment

    International Nuclear Information System (INIS)

    Jaegers, P.J.; Sanchez, R.G.

    1996-01-01

    Criticality benchmark data for intermediate energy spectrum systems does not exist. These systems are dominated by scattering and fission events induced by neutrons with energies between 1 eV and 1 MeV. Nuclear data uncertainties have been reported for such systems which can not be resolved without benchmark critical experiments. Intermediate energy spectrum systems have been proposed for the geological disposition of surplus fissile materials. Without the proper benchmarking of the nuclear data in the intermediate energy spectrum, adequate criticality safety margins can not be guaranteed. The Zeus critical experiment now under construction will provide this necessary benchmark data

  8. Synthesis of Joint Volumes, Visualization of Paths, and Revision of Viewing Sequences in a Multi-dimensional Seismic Data Viewer

    Science.gov (United States)

    Chen, D. M.; Clapp, R. G.; Biondi, B.

    2006-12-01

    Ricksep is a freely-available interactive viewer for multi-dimensional data sets. The viewer is very useful for simultaneous display of multiple data sets from different viewing angles, animation of movement along a path through the data space, and selection of local regions for data processing and information extraction. Several new viewing features are added to enhance the program's functionality in the following three aspects. First, two new data synthesis algorithms are created to adaptively combine information from a data set with mostly high-frequency content, such as seismic data, and another data set with mainly low-frequency content, such as velocity data. Using the algorithms, these two data sets can be synthesized into a single data set which resembles the high-frequency data set on a local scale and at the same time resembles the low- frequency data set on a larger scale. As a result, the originally separated high and low-frequency details can now be more accurately and conveniently studied together. Second, a projection algorithm is developed to display paths through the data space. Paths are geophysically important because they represent wells into the ground. Two difficulties often associated with tracking paths are that they normally cannot be seen clearly inside multi-dimensional spaces and depth information is lost along the direction of projection when ordinary projection techniques are used. The new algorithm projects samples along the path in three orthogonal directions and effectively restores important depth information by using variable projection parameters which are functions of the distance away from the path. Multiple paths in the data space can be generated using different character symbols as positional markers, and users can easily create, modify, and view paths in real time. Third, a viewing history list is implemented which enables Ricksep's users to create, edit and save a recipe for the sequence of viewing states. Then, the recipe

  9. Transient behavior of Cu/ZnO-based methanol synthesis catalysts

    DEFF Research Database (Denmark)

    Vesborg, Peter Christian Kjærgaard; Chorkendorff, Ib; Knudsen, Ida

    2009-01-01

    Time-resolved measurements of the methanol synthesis reaction over a Cu/ZnO-based catalyst reveal a transient methanol production that depends on the pretreatment gas. Specifically, the methanol production initially peaks after a pretreatment with an intermediate mixture of H2 and CO (20–80% H2...

  10. Total synthesis of (+)-antroquinonol and (+)-antroquinonol D.

    Science.gov (United States)

    Sulake, Rohidas S; Chen, Chinpiao

    2015-03-06

    The first total synthesis of (+)-antroquinonol and (+)-antroquinonol D, two structurally unique quinonols with a sesquiterpene side chain, is described. The route features an iridium-catalyzed olefin isomerization-Claisen rearrangement reaction (ICR), lactonization, and Grubbs olefin metathesis. The requisite α,β-unsaturation was achieved via the selenylation/oxidation protocol and elimination of β-methoxy group to provide two natural products from a common intermediate.

  11. Enzymatic synthesis of 5-methyluridine by transglycosylation of guanosine and thymine

    CSIR Research Space (South Africa)

    Visser, Daniel F

    2012-05-01

    Full Text Available 5-Methyluridine (5-MU) is an intermediate in the synthesis of ß-thymidine and the antiretroviral drugs stavudine (d4T) and zidovudine (AZT)1-3. The enzymatic preparation of 5-MU involves transglycosylation4-6 and avoids the formation of unwanted...

  12. Dolichol related intermediates involved in N-linked gloycoprotein synthesis in Drosophila Kc cells

    International Nuclear Information System (INIS)

    Sagami, H.; Chap, R.; Rivero, M.; Lennarz, W.J.

    1986-01-01

    The purpose of this investigation is to study the regulation of the biosynthesis of dolichyl phosphate (Dol-P) in embryonic cells. Using embryonic Drosophila Kc cells which are known to lack the squalene-cholesterol branch of polyisoprenoid biosynthetic pathway, the authors labeled the cells in suspension culture for 4 hrs with [5- 3 H]mevalonic acid. After harvesting the cells, the incorporated radioactive lipids were extracted with CHCl 3 /CH 3 OH (2/1). Analysis of the extract by a combination of several methods consisting of ion exchange chromatography on DEAE-cellulose, gel filtration on Fractogel TSK-HW 40, and silica gel thin layer chromatography revealed that the extract contained coenzyme Q, farnesol, dolichol (Dol), Dol-P, and dolichol-linked sugar (Dol-P-Sugar). In a pulse-chase experiment the metabolism of these intermediates was measured for various times up to 30 hrs. The amount of radioactivity in Dol slightly increased with the chase time, while that in Dol-P decreased. The amount of radioactive Dol-P-Sugar remained unchanged. These results suggest that the de novo end product in dolichol biosynthesis is Dol-P and that the level of Dol-P can be controlled by varying the rate of de novo biosynthesis and by dephosphorylation. The authors are now investigating the effect of ecdysone, the molting hormone, on the level of these intermediates and on incorporation of sugars into glycoproteins

  13. Mapping intermediate degradation products of poly(lactic-co-glycolic acid) in vitro.

    Science.gov (United States)

    Li, Jian; Nemes, Peter; Guo, Ji

    2018-04-01

    There is widespread interest in using absorbable polymers, such as poly(lactic-co-glycolic acid) (PLGA), as components in the design and manufacture of new-generation drug eluting stents (DES). PLGA undergoes hydrolysis to progressively degrade through intermediate chemical entities to simple organic acids that are ultimately absorbed by the human body. Understanding the composition and structure of these intermediate degradation products is critical not only to elucidate polymer degradation pathways accurately, but also to assess the safety and performance of absorbable cardiovascular implants. However, analytical approaches to determining the intermediate degradation products have yet to be established and evaluated in a standard or regulatory setting. Hence, we developed a methodology using electrospray ionization mass spectrometry to qualitatively and quantitatively describe intermediate degradation products generated in vitro from two PLGA formulations commonly used in DES. Furthermore, we assessed the temporal evolution of these degradation products using time-lapse experiments. Our data demonstrated that PLGA degradation products via heterogeneous cleavage of ester bonds are modulated by multiple intrinsic and environmental factors, including polymer chemical composition, degradants solubility in water, and polymer synthesis process. We anticipate the methodologies and outcomes presented in this work will elevate the mechanistic understanding of comprehensive degradation profiles of absorbable polymeric devices, and facilitate the design and regulation of cardiovascular implants by supporting the assessments of the associated biological response to degradation products. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1129-1137, 2018. © 2017 Wiley Periodicals, Inc.

  14. Chirality of Intermediate Filaments and Magnetic Helicity of Active Regions

    Science.gov (United States)

    Lim, Eun-Kyung; Chae, J.

    2009-05-01

    Filaments that form either between or around active regions (ARs) are called intermediate filaments. Even though there have been many theoretical studies, the origin of the chirality of filaments is still unknown. We investigated how intermediate filaments are related to their associated ARs, especially from the point of view of magnetic helicity and the orientation of polarity inversion lines (PILs). The chirality of filaments has been determined based on the orientations of barbs observed in the full-disk Hα images taken at Big Bear Solar Observatory during the rising phase of solar cycle 23. The sign of magnetic helicity of ARs has been determined using S/inverse-S shaped sigmoids from Yohkoh SXT images. As a result, we have found a good correlation between the chirality of filaments and the magnetic helicity sign of ARs. Among 45 filaments, 42 filaments have shown the same sign as helicity sign of nearby ARs. It has been also confirmed that the role of both the orientation and the relative direction of PILs to ARs in determining the chirality of filaments is not significant, against a theoretical prediction. These results suggest that the chirality of intermediate filaments may originate from magnetic helicity of their associated ARs.

  15. The ortho backbone amide linker (o-BAL) is an easily prepared and highly acid-labile handle for solid-phase synthesis

    DEFF Research Database (Denmark)

    Boas, Ulrik; Brask, Jesper; Christensen, J.B.

    2002-01-01

    The tris(alkoxy)benzyl backbone amide linker (BAL) has found widespread application in solid-phase synthesis. The key intermediate for preparation of para BAL (p-BAL) is 2,6-dimethoxy-4-hydroxybenzaldehyde; several reports on its synthesis have appeared. However, the ortho analogue of the handle (o...

  16. Efficient Enzymatic Routes for the Synthesis of New Eight-membered Cyclic β-Amino Acid and β-Lactam Enantiomers

    Directory of Open Access Journals (Sweden)

    Enikő Forró

    2017-12-01

    Full Text Available Efficient enzymatic resolutions are reported for the preparation of new eight-membered ring-fused enantiomeric β-amino acids [(1R,2S-9 and (1S,2R-9] and β-lactams [(1S,8R-3, (1R,8S-3 (1S,8R-4 and (1R,8S-7], through asymmetric acylation of (±-4 (E > 100 or enantioselective hydrolysis (E > 200 of the corresponding inactivated (±-3 or activated (±-4 β-lactams, catalyzed by PSIM or CAL-B in an organic solvent. CAL-B-catalyzed ring cleavage of (±-6 (E > 200 resulted in the unreacted (1S,8R-6, potential intermediate for the synthesis of enantiomeric anatoxin-a. The best strategies, in view of E, reaction rate and product yields, which underline the importance of substrate engineering, are highlighted.

  17. Chemistry of Ammonothermal Synthesis

    Directory of Open Access Journals (Sweden)

    Theresia M. M. Richter

    2014-02-01

    Full Text Available Ammonothermal synthesis is a method for synthesis and crystal growth suitable for a large range of chemically different materials, such as nitrides (e.g., GaN, AlN, amides (e.g., LiNH2, Zn(NH22, imides (e.g., Th(NH2, ammoniates (e.g., Ga(NH33F3, [Al(NH36]I3 · NH3 and non-nitrogen compounds like hydroxides, hydrogen sulfides and polychalcogenides (e.g., NaOH, LiHS, CaS, Cs2Te5. In particular, large scale production of high quality crystals is possible, due to comparatively simple scalability of the experimental set-up. The ammonothermal method is defined as employing a heterogeneous reaction in ammonia as one homogenous fluid close to or in supercritical state. Three types of milieus may be applied during ammonothermal synthesis: ammonobasic, ammononeutral or ammonoacidic, evoked by the used starting materials and mineralizers, strongly influencing the obtained products. There is little known about the dissolution and materials transport processes or the deposition mechanisms during ammonothermal crystal growth. However, the initial results indicate the possible nature of different intermediate species present in the respective milieus.

  18. Autoradiographic study of gamma-ray induced unscheduled DNA synthesis in bean root meristem cells

    International Nuclear Information System (INIS)

    Liu Zhenshen; Qiu Quanfa; Chen Dongli

    1989-01-01

    The gamma-ray induced unscheduled DNA synthesis in root meristem cells of Vica faba was studied autoradiographically by calculating the number of cells with different 3H-thymidine labelling degree. It was found that the level of unscheduled synthesis in cells with intermediate dose (500 R) irradiation was higher than that in cells with lower dose (250 R) irradiation; however, higher dose (1000 R) irradiation would inhibit the reparative replication

  19. "Nanorust"-catalyzed benign oxidation of amines for selective synthesis of nitriles.

    Science.gov (United States)

    Jagadeesh, Rajenahally V; Junge, Henrik; Beller, Matthias

    2015-01-01

    Organic nitriles constitute key precursors and central intermediates in organic synthesis. In addition, nitriles represent a versatile motif found in numerous medicinally and biologically important compounds. Generally, these nitriles are synthesized by traditional cyanation procedures using toxic cyanides. Herein, we report the selective and environmentally benign oxidative conversion of primary amines for the synthesis of structurally diverse aromatic, aliphatic and heterocyclic nitriles using a reusable "nanorust" (nanoscale Fe2 O3 )-based catalysts applying molecular oxygen. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. One-pot three-component synthesis of quinoxaline and phenazine ring systems using Fischer carbene complexes

    Directory of Open Access Journals (Sweden)

    Priyabrata Roy

    2010-05-01

    Full Text Available One-pot three-component coupling of o-alkynylheteroaryl carbonyl derivatives with Fischer carbene complexes and dienophiles leading to the synthesis of quinoxaline and phenazine ring systems has been investigated. This involves the generation of furo[3,4-b]pyrazine and furo[3,4-b]quinoxaline as transient intermediates, which were trapped with Diels–Alder dienophiles. This is the first report on furo[3,4-b]pyrazine intermediates.

  1. Stakeholders' views and experiences of care and interventions for addressing frailty and pre-frailty: A meta-synthesis of qualitative evidence.

    Directory of Open Access Journals (Sweden)

    Barbara D'Avanzo

    Full Text Available Frailty is a common condition in older age and is a public health concern which requires integrated care and involves different stakeholders. This meta-synthesis focuses on experiences, understanding, and attitudes towards screening, care, intervention and prevention for frailty across frail and healthy older persons, caregivers, health and social care practitioners. Studies published since 2001 were identified through search of electronic databases; 81 eligible papers were identified and read in full, and 45 papers were finally included and synthesized. The synthesis was conducted with a meta-ethnographic approach. We identified four key themes: Uncertainty about malleability of frailty; Strategies to prevent or to respond to frailty; Capacity to care and person and family-centred service provision; Power and choice. A bottom-up approach which emphasises and works in synchrony with frail older people's and their families' values, goals, resources and optimisation strategies is necessary. A greater employment of psychological skills, enhancing communication abilities and tools to overcome disempowering attitudes should inform care organisation, resulting in more efficient and satisfactory use of services. Public health communication about prevention and management of frailty should be founded on a paradigm of resilience, balanced acceptance, and coping. Addressing stakeholders' views about the preventability of frailty was seen as a salient need.

  2. Occlusion-Aware View Interpolation

    Directory of Open Access Journals (Sweden)

    Ince Serdar

    2008-01-01

    Full Text Available Abstract View interpolation is an essential step in content preparation for multiview 3D displays, free-viewpoint video, and multiview image/video compression. It is performed by establishing a correspondence among views, followed by interpolation using the corresponding intensities. However, occlusions pose a significant challenge, especially if few input images are available. In this paper, we identify challenges related to disparity estimation and view interpolation in presence of occlusions. We then propose an occlusion-aware intermediate view interpolation algorithm that uses four input images to handle the disappearing areas. The algorithm consists of three steps. First, all pixels in view to be computed are classified in terms of their visibility in the input images. Then, disparity for each pixel is estimated from different image pairs depending on the computed visibility map. Finally, luminance/color of each pixel is adaptively interpolated from an image pair selected by its visibility label. Extensive experimental results show striking improvements in interpolated image quality over occlusion-unaware interpolation from two images and very significant gains over occlusion-aware spline-based reconstruction from four images, both on synthetic and real images. Although improvements are obvious only in the vicinity of object boundaries, this should be useful in high-quality 3D applications, such as digital 3D cinema and ultra-high resolution multiview autostereoscopic displays, where distortions at depth discontinuities are highly objectionable, especially if they vary with viewpoint change.

  3. Occlusion-Aware View Interpolation

    Directory of Open Access Journals (Sweden)

    Janusz Konrad

    2009-01-01

    Full Text Available View interpolation is an essential step in content preparation for multiview 3D displays, free-viewpoint video, and multiview image/video compression. It is performed by establishing a correspondence among views, followed by interpolation using the corresponding intensities. However, occlusions pose a significant challenge, especially if few input images are available. In this paper, we identify challenges related to disparity estimation and view interpolation in presence of occlusions. We then propose an occlusion-aware intermediate view interpolation algorithm that uses four input images to handle the disappearing areas. The algorithm consists of three steps. First, all pixels in view to be computed are classified in terms of their visibility in the input images. Then, disparity for each pixel is estimated from different image pairs depending on the computed visibility map. Finally, luminance/color of each pixel is adaptively interpolated from an image pair selected by its visibility label. Extensive experimental results show striking improvements in interpolated image quality over occlusion-unaware interpolation from two images and very significant gains over occlusion-aware spline-based reconstruction from four images, both on synthetic and real images. Although improvements are obvious only in the vicinity of object boundaries, this should be useful in high-quality 3D applications, such as digital 3D cinema and ultra-high resolution multiview autostereoscopic displays, where distortions at depth discontinuities are highly objectionable, especially if they vary with viewpoint change.

  4. Total Synthesis of Ionic Liquid Systems for Dissolution of Lunar Simulant

    Science.gov (United States)

    Sharpe, Robert J.; Karr, Laurel J.; Paley, Mark S.

    2010-01-01

    For purposes of Space Resource Utilization, work in the total synthesis of a new ionic liquid system for the extraction of oxygen and metals from lunar soil is studied and described. Reactions were carried out according to procedures found in the chemical literature, analyzed via Thin-Layer Chromatography and 1H Nuclear Magnetic Resonance Spectroscopy and purified via vacuum distillation and rotary evaporation. Upon final analysis via 1H NMR, it was found that while the intermediates of the synthesis had been achieved, unexpected side products were also present. The mechanisms and constraints of the synthesis are described as well as the final results of the project and recommendations for continued study

  5. Haldane's The causes of evolution and the Modern Synthesis in ...

    Indian Academy of Sciences (India)

    This paper argues that Haldane's The causes of evolution was the most important founding document in the emergence of the received view of evolutionary theory which is typically referred to as the Modern Synthesis. Whether or not this historical development is characterized as a synthesis (which remains controversial), ...

  6. Analyze of viability of ZrSiO_4-Fe_2O_3 pigments synthesis, from decomposition of the zircon

    International Nuclear Information System (INIS)

    Prim, S.R.; Folgueiras, M.V.; Winter, D.M.

    2011-01-01

    Zircon pigments are commonly used in ceramic industry due to their high chemical and thermal stability. In the present work, the viability of synthesis of a zircon ceramic pigment from intermediate products obtained from decomposition zircon sand with NaOH and/or KOH at 750 and 850 °C was studied. The intermediate products were used as raw materials to produce pigments. Iron oxide from rolling process of sheet metal was used as chromophore. The crystalline phases formed were characterized by X-ray diffraction. The results have shown that it was possible to obtain the partial decomposition of zircon which enables the development of the synthesis of zircon pigment. (author)

  7. Preparation of radiohalogenated biomolecules via organotin intermediates. Ch. 8

    International Nuclear Information System (INIS)

    Hanson, R.N.

    1991-01-01

    The purpose of this review is to describe the specific application of organotin chemistry to the preparation of radiohalogenated bio-organic compounds as radiotracers. Although the research group was the first to apply the radiohalodestannylation methodology to the synthesis of a labeled compound of biological interest, iodotamoxifen, and subsequently extended its use to the labeled hormones, dopamine receptor antagonists and perfusion agents, the versatility of the method has subsequently found broad acceptance. For many situations in which high specific activity, rapidity of incorporation and labeling site specificity are required, electrophilic destannylation is the method of choice. The sections that follow provide a description of the development of radiohalodestannylation and its application in radiopharmaceutical chemistry. The first section will briefly review the criteria that define the radionuclidic, biochemical and chemical limits associated with radiopharmaceuticals. The next section describes the rationale for the choice of organotin intermediates and highlights the methods available for their synthesis. Following that section are several areas of biomedical research interest that illustrate how organotin chemistry has been applied in the preparation of specific radiohalogenated compounds. Although the examples will focus primarily on situations that require high affinity and specific activity, labeled derivatives which were prepared to evaluate more general physiological properties will also be reviewed. (author). 171 refs

  8. RNA-Seq analysis uncovers non-coding small RNA system of Mycobacterium neoaurum in the metabolism of sterols to accumulate steroid intermediates.

    Science.gov (United States)

    Liu, Min; Zhu, Zhan-Tao; Tao, Xin-Yi; Wang, Feng-Qing; Wei, Dong-Zhi

    2016-04-25

    Understanding the metabolic mechanism of sterols to produce valuable steroid intermediates in mycobacterium by a noncoding small RNA (sRNA) view is still limited. In the work, RNA-seq was implemented to investigate the noncoding transcriptome of Mycobacterium neoaurum (Mn) in the transformation process of sterols to valuable steroid intermediates, including 9α-hydroxy-4-androstene-3,17-dione (9OHAD), 1,4-androstadiene-3,17-dione (ADD), and 22-hydroxy-23, 24-bisnorchola-1,4-dien-3-one (1,4-BNA). A total of 263 sRNA candidates were predicted from the intergenic regions in Mn. Differential expression of sRNA candidates was explored in the wide type Mn with vs without sterol addition, and the steroid intermediate producing Mn strains vs wide type Mn with sterol addition, respectively. Generally, sRNA candidates were differentially expressed in various strains, but there were still some shared candidates with outstandingly upregulated or downregulated expression in these steroid producing strains. Accordingly, four regulatory networks were constructed to reveal the direct and/or indirect interactions between sRNA candidates and their target genes in four groups, including wide type Mn with vs without sterol addition, 9OHAD, ADD, and BNA producing strains vs wide type Mn with sterol addition, respectively. Based on these constructed networks, several highly focused sRNA candidates were discovered to be prevalent in the networks, which showed comprehensive regulatory roles in various cellular processes, including lipid transport and metabolism, amino acid transport and metabolism, signal transduction, cell envelope biosynthesis and ATP synthesis. To explore the functional role of sRNA candidates in Mn cells, we manipulated the overexpression of candidates 131 and 138 in strain Mn-9OHAD, which led to enhanced production of 9OHAD from 1.5- to 2.3-fold during 6 d' fermentation and a slight effect on growth rate. This study revealed the complex and important regulatory

  9. Balanced activation of IspG and IspH to eliminate MEP intermediate accumulation and improve isoprenoids production in Escherichia coli.

    Science.gov (United States)

    Li, Qingyan; Fan, Feiyu; Gao, Xiang; Yang, Chen; Bi, Changhao; Tang, Jinlei; Liu, Tao; Zhang, Xueli

    2017-11-01

    The MEP pathway genes were modulated to investigate whether there were new rate-limiting steps and toxic intermediates in this pathway. Activating IspG led to significant decrease of cell growth and β-carotene production. It was found that ispG overexpression led to accumulation of intermediate HMBPP, which seriously interfered with synthesis machinery of nucleotide and protein in Escherichia coli. Activation of the downstream enzyme IspH could solve HMBPP accumulation problem and eliminate the negative effects of ispG overexpression. In addition, intermediate MECPP accumulated in the starting strain, while balanced activation of IspG and IspH could push the carbon flux away from MECPP and led to 73% and 77% increase of β-carotene and lycopene titer respectively. Our work for the first time identified HMBPP to be a cytotoxic intermediate in MEP pathway and demonstrated that balanced activation of IspG and IspH could eliminate accumulation of HMBPP and MECPP and improve isoprenoids production. Copyright © 2017 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

  10. Radiation protection criteria in the long-range view

    International Nuclear Information System (INIS)

    Snihs, J.O.; Bergman, C.

    1989-01-01

    The report presents by way of introduction radiation protection criteria applied to radiological activities and to disposal of low-level and intermediate-level radioactive waste. In these cases it is primarily short-range views that are relevant, up to a few thousand years as a maximum. In the case of high-level wastes where the views may extend to more than hundreds of thousands years, there are not for the present any equally well stablished criteria. Based upon preliminary results from a Nordic team for criteria for high-level radioactive wastes, dose estimates in the long-range view and alternative assessment criteria are discussed. Proposals are also presented for 12 criteria that may be applicable. As the work is not yet finshed, the criteria are however merely preliminary

  11. A concise enantioselective synthesis of the guaiane sesquiterpene (−-oxyphyllol

    Directory of Open Access Journals (Sweden)

    Martin Zahel

    2013-10-01

    Full Text Available (−-Oxyphyllol was prepared in only 4 steps from an epoxy enone that already served as an intermediate for the total synthesis of the anticancer guaiane (−-englerin A. A regio- and diastereoselective Co(II-catalyzed hydration of the olefin and a transannular epoxide opening were used as the key reactions.

  12. Current views on the regulation of autotrophic carbon dioxide fixation via the Calvin cycle in bacteria

    NARCIS (Netherlands)

    Dijkhuizen, L.; Harder, W.

    1984-01-01

    The Calvin cycle of carbon dioxide fixation constitutes a biosynthetic pathway for the generation of (multi-carbon) intermediates of central metabolism from the one-carbon compound carbon dioxide. The product of this cycle can be used as a precursor for the synthesis of all components of cell

  13. Intermediality and media change

    OpenAIRE

    2012-01-01

    This book is about intermediality as an approach to analysing and understanding media change. Intermediality and Media Change is critical of technological determinism that characterises 'new media discourse' about the ongoing digitalization, framed as a revolution and creating sharp contrasts between old and new media. Intermediality instead emphasises paying attention to continuities between media of all types and privileges a comparative perspective on technological changes in media over ti...

  14. Probing the Influence of Linker Length and Flexibility in the Design and Synthesis of New Trehalase Inhibitors

    Directory of Open Access Journals (Sweden)

    Giampiero D’Adamio

    2018-02-01

    Full Text Available This work aims to synthesize new trehalase inhibitors selective towards the insect trehalase versus the porcine trehalase, in view of their application as potentially non-toxic insecticides and fungicides. The synthesis of a new pseudodisaccharide mimetic 8, by means of a stereoselective α-glucosylation of the key pyrrolizidine intermediate 13, was accomplished. The activity of compound 8 as trehalase inhibitor towards C. riparius trehalase was evaluated and the results showed that 8 was active in the μM range and showed a good selectivity towards the insect trehalase. To reduce the overall number of synthetic steps, simpler and more flexible disaccharide mimetics 9–11 bearing a pyrrolidine nucleus instead of the pyrrolizidine core were synthesized. The biological data showed the key role of the linker chain’s length in inducing inhibitory properties, since only compounds 9 (α,β-mixture, bearing a two-carbon atom linker chain, maintained activity as trehalase inhibitors. A proper change in the glucosyl donor-protecting groups allowed the stereoselective synthesis of the β-glucoside 9β, which was active in the low micromolar range (IC50 = 0.78 μM and 12-fold more potent (and more selective than 9α towards the insect trehalase.

  15. One-step synthesis of pyridines and dihydropyridines in a continuous flow microwave reactor

    Directory of Open Access Journals (Sweden)

    Mark C. Bagley

    2013-09-01

    Full Text Available The Bohlmann–Rahtz pyridine synthesis and the Hantzsch dihydropyridine synthesis can be carried out in a microwave flow reactor or using a conductive heating flow platform for the continuous processing of material. In the Bohlmann–Rahtz reaction, the use of a Brønsted acid catalyst allows Michael addition and cyclodehydration to be carried out in a single step without isolation of intermediates to give the corresponding trisubstituted pyridine as a single regioisomer in good yield. Furthermore, 3-substituted propargyl aldehydes undergo Hantzsch dihydropyridine synthesis in preference to Bohlmann–Rahtz reaction in a very high yielding process that is readily transferred to continuous flow processing.

  16. Synthesis of racemic 2-deutero-3-fluoro-alanine and its salts, and intermediates therefor

    International Nuclear Information System (INIS)

    1975-01-01

    The racemates of 2-deutero-3-fluoro-alanine and its salts are prepared by reductive amination of 3-fluoro-pyruvic acid, its hydrate or salts thereof, via the intermediate 2-imino-3-fluoro propionic acid salt, using alkali metal borodeuterides as reducing agents. The racemates thus obtained are valuable in the production of the corresponding 2-deutero-3-fluoro-D-alanine, and its pharmacologically acceptable salts, and derivatives thereof, which are potent antibacterial agents

  17. Iminodiacetic acid derivatives of benzimidazole. Synthesis of N-(benzimidazol-2-ylmethyl)iminodiacetic acids

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, F C; Wilson, J G [Australian Atomic Energy Commission Research Establishment, Lucas Heights. Isotope Div.

    1983-01-01

    Ten new N-(2-benzimidazolylmethyl)iminodiacetic acids (BIMIDA) have been synthesized from the corresponding o-phenylenediamines via intermediate 2-chloromethyl and 2-aminomethyl benzimidazoles as ligands for Tc-99m. Anomalies associated with the synthesis of the iodo-substituted compound are described.

  18. Application of enantioselective radical reactions: synthesis of (+)-ricciocarpins A and B.

    Science.gov (United States)

    Sibi, Mukund P; He, Liwen

    2004-05-27

    Enantioselective synthesis of (+)-ricciocarpins A and B has been achieved in 41 and 45% overall yields, respectively, starting from a beta-substituted oxazolidinone. The key steps in the strategy are an enantioselective conjugate radical addition and the addition of a furyl organometallic to a key aldehyde intermediate. [reaction--see text

  19. Synthesis of the carbocyclic core of the cornexistins by ring-closing metathesis.

    Science.gov (United States)

    Clark, J Stephen; Marlin, Frederic; Nay, Bastien; Wilson, Claire

    2003-01-09

    An advanced intermediate in the synthesis of the phytotoxins cornexistin and hydroxycornexistin has been synthesized. Sequential palladium-mediated sp(2)-sp(3) fragment coupling and ring-closing diene metathesis have been used to construct the nine-membered carbocyclic core found in the natural products. [reaction--see text

  20. Synthesis of a new compound - Sr2CuO2CO3

    International Nuclear Information System (INIS)

    Fomichev, D.V.; Khardanov, A.L.; Antipov, E.V.; Kovba, L.M.

    1990-01-01

    A new compound of Sr 2 CuO 2 CO 3 composition, being an intermediate product of solid phase synthesis in air in SrCo 3 -CuO system at T 2 CuO 2 CO 3 have low resistance at room temperature and semiconductor type conductivity

  1. Synthesis of unstable cyclic peroxides for chemiluminescence studies

    Energy Technology Data Exchange (ETDEWEB)

    Bartoloni, Fernando H.; Oliveira, Marcelo A. de; Augusto, Felipe A.; Ciscato, Luiz Francisco M.L.; Bastos, Erick L.; Baader, Wilhelm J., E-mail: wjbaader@iq.usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica. Dept. de Quimica Fundamental

    2012-11-15

    Cyclic four-membered ring peroxides are important high-energy intermediates in a variety of chemi and bioluminescence transformations. Specifically, a-peroxy lactones (1,2-dioxetanones) have been considered as model systems for efficient firefly bioluminescence. However, the preparation of such highly unstable compounds is extremely difficult and, therefore, only few research groups have been able to study the properties of these substances. In this study, the synthesis, purification and characterization of three 1,2-dioxetanones are reported and a detailed procedure for the known synthesis of diphenoyl peroxide, another important model compound for the chemical generation of electronically excited states, is provided. For most of these peroxides, the complete spectroscopic characterization is reported here for the first time. (author)

  2. A scalable synthesis of 5,5'-dibromo-2,2'-bipyridine and its stepwise functionalization via Stille couplings.

    Science.gov (United States)

    D'Souza, Daniel M; Leigh, David A; Papmeyer, Marcus; Woltering, Steffen L

    2012-11-01

    The synthesis of 5,5'-dibromo-2,2'-bipyridine and 5-bromo-2,2'-bipyridine, useful intermediates for elaboration into more complex ligands through metal-catalyzed coupling reactions, can be efficiently conducted on a multigram scale from inexpensive starting materials. The described procedure is reliably scalable and suitable for the synthesis of tens of grams of 5,5'-dibromo-2,2'-bipyridine. 5-Bromo-2,2'-bipyridine is produced as a minor product. The 5,5'-disubstituted-2,2'-bipyridine motif has excellent coordination properties and is a versatile building block for the synthesis of functional materials (including biodiagnostics, photovoltaics and organic light-emitting diodes) and complex molecular topologies (including catenanes and trefoil and pentafoil knots). The selective stepwise functionalization of 5,5'-dibromo-2,2'-bipyridine by consecutive Stille couplings is therefore illustrated and documented in detail. The synthesis of 5,5'-dibromo-2,2'-bipyridine takes 4-5 d: 1 d to prepare the key intermediate 2,2'-bipyridine dihydrobromide, 3 d for its reaction with bromine in a steel bomb reaction vessel and 8 h to isolate and purify the final product.

  3. Steroid synthesis by primary human keratinocytes; implications for skin disease

    Energy Technology Data Exchange (ETDEWEB)

    Hannen, Rosalind F., E-mail: r.f.hannen@qmul.ac.uk [Centre for Cutaneous Research, Institute of Cell and Molecular Science, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT (United Kingdom); Michael, Anthony E. [Centre for Developmental and Endocrine Signalling, Academic Section of Obstetrics and Gynaecology, Division of Clinical Developmental Sciences, 3rd Floor, Lanesborough Wing, St. George' s, University of London, Cranmer Terrace, Tooting, London SW17 0RE (United Kingdom); Jaulim, Adil [Centre for Cutaneous Research, Institute of Cell and Molecular Science, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT (United Kingdom); Bhogal, Ranjit [Life Science, Unilever R and D Colworth House, Sharnbrook, Bedfordshire MK44 1LQ (United Kingdom); Burrin, Jacky M. [Centre for Endocrinology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London EC1M 6BQ (United Kingdom); Philpott, Michael P. [Centre for Cutaneous Research, Institute of Cell and Molecular Science, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London E1 2AT (United Kingdom)

    2011-01-07

    Research highlights: {yields} Primary keratinocytes express the steroid enzymes required for cortisol synthesis. {yields} Normal primary human keratinocytes can synthesise cortisol. {yields} Steroidogenic regulators, StAR and MLN64, are expressed in normal epidermis. {yields} StAR expression is down regulated in eczema and psoriatic epidermis. -- Abstract: Cortisol-based therapy is one of the most potent anti-inflammatory treatments available for skin conditions including psoriasis and atopic dermatitis. Previous studies have investigated the steroidogenic capabilities of keratinocytes, though none have demonstrated that these skin cells, which form up to 90% of the epidermis are able to synthesise cortisol. Here we demonstrate that primary human keratinocytes (PHK) express all the elements required for cortisol steroidogenesis and metabolise pregnenolone through each intermediate steroid to cortisol. We show that normal epidermis and cultured PHK express each of the enzymes (CYP11A1, CYP17A1, 3{beta}HSD1, CYP21 and CYP11B1) that are required for cortisol synthesis. These enzymes were shown to be metabolically active for cortisol synthesis since radiometric conversion assays traced the metabolism of [7-{sup 3}H]-pregnenolone through each steroid intermediate to [7-{sup 3}H]-cortisol in cultured PHK. Trilostane (a 3{beta}HSD1 inhibitor) and ketoconazole (a CYP17A1 inhibitor) blocked the metabolism of both pregnenolone and progesterone. Finally, we show that normal skin expresses two cholesterol transporters, steroidogenic acute regulatory protein (StAR), regarded as the rate-determining protein for steroid synthesis, and metastatic lymph node 64 (MLN64) whose function has been linked to cholesterol transport in steroidogenesis. The expression of StAR and MLN64 was aberrant in two skin disorders, psoriasis and atopic dermatitis, that are commonly treated with cortisol, suggesting dysregulation of epidermal steroid synthesis in these patients. Collectively these data

  4. Steroid synthesis by primary human keratinocytes; implications for skin disease

    International Nuclear Information System (INIS)

    Hannen, Rosalind F.; Michael, Anthony E.; Jaulim, Adil; Bhogal, Ranjit; Burrin, Jacky M.; Philpott, Michael P.

    2011-01-01

    Research highlights: → Primary keratinocytes express the steroid enzymes required for cortisol synthesis. → Normal primary human keratinocytes can synthesise cortisol. → Steroidogenic regulators, StAR and MLN64, are expressed in normal epidermis. → StAR expression is down regulated in eczema and psoriatic epidermis. -- Abstract: Cortisol-based therapy is one of the most potent anti-inflammatory treatments available for skin conditions including psoriasis and atopic dermatitis. Previous studies have investigated the steroidogenic capabilities of keratinocytes, though none have demonstrated that these skin cells, which form up to 90% of the epidermis are able to synthesise cortisol. Here we demonstrate that primary human keratinocytes (PHK) express all the elements required for cortisol steroidogenesis and metabolise pregnenolone through each intermediate steroid to cortisol. We show that normal epidermis and cultured PHK express each of the enzymes (CYP11A1, CYP17A1, 3βHSD1, CYP21 and CYP11B1) that are required for cortisol synthesis. These enzymes were shown to be metabolically active for cortisol synthesis since radiometric conversion assays traced the metabolism of [7- 3 H]-pregnenolone through each steroid intermediate to [7- 3 H]-cortisol in cultured PHK. Trilostane (a 3βHSD1 inhibitor) and ketoconazole (a CYP17A1 inhibitor) blocked the metabolism of both pregnenolone and progesterone. Finally, we show that normal skin expresses two cholesterol transporters, steroidogenic acute regulatory protein (StAR), regarded as the rate-determining protein for steroid synthesis, and metastatic lymph node 64 (MLN64) whose function has been linked to cholesterol transport in steroidogenesis. The expression of StAR and MLN64 was aberrant in two skin disorders, psoriasis and atopic dermatitis, that are commonly treated with cortisol, suggesting dysregulation of epidermal steroid synthesis in these patients. Collectively these data show that PHK are capable of extra

  5. Intermediate Fragment

    DEFF Research Database (Denmark)

    Kruse Aagaard, Anders

    2015-01-01

    This text and its connected exhibition are aiming to reflect both on the thoughts, the processes and the outcome of the design and production of the artefact ‘Intermediate Fragment’ and making as a contemporary architectural tool in general. Intermediate Fragment was made for the exhibition ‘Enga...... of realising an exhibition object was conceived, but expanded, refined and concretised through this process. The context of the work shown here is an interest in a tighter, deeper connection between experimentally obtained material knowledge and architectural design....

  6. Governance-Default Risk Relationship and the Demand for Intermediated and Non-Intermediated Debt

    Directory of Open Access Journals (Sweden)

    Husam Aldamen

    2012-09-01

    Full Text Available This paper explores the impact of corporate governance on the demand for intermediated debt (asset finance, bank debt, non-bank private debt and non-intermediated debt (public debt in the Australian debt market. Relative to other countries the Australian debt market is characterised by higher proportions of intermediated or private debt with a lower inherent level of information asymmetry in that private lenders have greater access to financial information (Gray, Koh & Tong 2009. Our firm level, cross-sectional evidence suggests that higher corporate governance impacts demand for debt via the mitigation of default risk. However, this relationship is not uniform across all debt types. Intermediated debt such as bank and asset finance debt are more responsive to changes in governance-default risk relationship than non-bank and non-intermediated debt. The implication is that a firm’s demand for different debt types will reflect its governance-default risk profile.

  7. Total Synthesis of (+)-Cytosporolide A via a Biomimetic Hetero-Diels-Alder Reaction.

    Science.gov (United States)

    Takao, Ken-Ichi; Noguchi, Shuji; Sakamoto, Shu; Kimura, Mizuki; Yoshida, Keisuke; Tadano, Kin-Ichi

    2015-12-23

    The first total synthesis of (+)-cytosporolide A was achieved by a biomimetic hetero-Diels-Alder reaction of (-)-fuscoatrol A with o-quinone methide generated from (+)-CJ-12,373. The dienophile, highly oxygenated caryophyllene sesquiterpenoid (-)-fuscoatrol A, was synthesized from the synthetic intermediate in our previous total synthesis of (+)-pestalotiopsin A. The o-quinone methide precursor, isochroman carboxylic acid (+)-CJ-12,373, was synthesized through a Kolbe-Schmitt reaction and an oxa-Pictet-Spengler reaction. The hetero-Diels-Alder reaction of these two compounds proceeded with complete chemo-, regio-, and stereoselectivity to produce the complicated pentacyclic ring system of the cytosporolide skeleton. This total synthesis unambiguously demonstrates that natural cytosporolide A has the structure previously suggested.

  8. Synthesis of Cyclic Py-Im Polyamide Libraries

    OpenAIRE

    Li, Benjamin C.; Montgomery, David C.; Puckett, James W.; Dervan, Peter B.

    2013-01-01

    Cyclic Py-Im polyamides containing two GABA turn units exhibit enhanced DNA binding affinity, but extensive studies of their biological properties have been hindered due to synthetic inaccessibility. A facile modular approach toward cyclic polyamides has been developed via microwave-assisted solid-phase synthesis of hairpin amino acid oligomer intermediates followed by macrocyclization. A focused library of cyclic polyamides 1–7 targeted to the androgen response element (ARE) and the estrogen...

  9. Selenium and tellurium reagents in organic synthesis

    International Nuclear Information System (INIS)

    Comasseto, J.V.

    1984-01-01

    A review of the contribution of the University of Sao Paulo (SP, Brazil) to the organic synthesis of selenium and tellurium reagents is made. Major reactions amoung selenium compounds and insaturated substrates, phosphorus, ester enolates as well as the use of phase transference catalysed reactions to produce arylselenolate are described. For tellurium, interactions of its compounds with organic substrates and reactive intermediates (e.g. benzino diazomethane) are reported. (C.L.B.) [pt

  10. Coupling of glycerol processing with Fischer-Tropsch synthesis for production of liquid fuels

    DEFF Research Database (Denmark)

    Simonetti, D.A.; Rass-Hansen, Jeppe; Kunkes, E.L.

    2007-01-01

    Liquid alkanes can be produced directly from glycerol by an integrated process involving catalytic conversion to H-2/CO gas mixtures (synthesis gas) combined with Fischer-Tropsch synthesis. Synthesis gas can be produced at high rates and selectivities suitable for Fischer-Tropsch synthesis (H-2/CO...... between 1.0 and 1.6) from concentrated glycerol feed solutions at low temperatures (548 K) and high pressures (1-17 bar) over a 10 wt% Pt-Re/C catalyst with an atomic Pt : Re ratio of 1 : 1. The primary oxygenated hydrocarbon intermediates formed during conversion of glycerol to synthesis gas are ethanol...... in the liquid organic effluent stream and increasing the selectivity to C5+ alkanes by a factor of 2 ( from 0.30 to 0.60). Catalytic conversion of glycerol and Fischer-Tropsch synthesis were coupled in a two-bed reactor system consisting of a Pt-Re/C catalyst bed followed by a Ru/TiO2 catalyst bed...

  11. A brief review of intermediate controlled nuclear syntheses (ICNS) without harmful radiations

    Energy Technology Data Exchange (ETDEWEB)

    Lanjewar, R. B. [Department of Chemistry Dharampeth M. P. Deo Memorial Science College, NAGPUR-440033, India rb-lanjewar@rediffmail.com (India)

    2015-03-10

    Hadronic mechanics gave birth to new magnecular fuels. The present day demand is of clean energy source that is cheap and abundant. Clean energy can be obtained by harnessing renewable energy sources like solar, wind etc. Nuclear energy conventionally produced by fission reactions emits hazardous radiation and radioactive waste. The requirements of clean and safe energy gets fulfilled by novel fuel that achieved by elevating the traditional quantum mechanics to hadronic mechanics and to hadronic chemistry. In the present paper, a comprehensive review on both the theoretical and experimental aspect of the Intermediate Controlled Nuclear Synthesis (ICNS) as developed by Italian American Scientist Professor R. M. Santilli.

  12. The ribosome can prevent aggregation of partially folded protein intermediates: studies using the Escherichia coli ribosome.

    Directory of Open Access Journals (Sweden)

    Bani Kumar Pathak

    Full Text Available BACKGROUND: Molecular chaperones that support de novo folding of proteins under non stress condition are classified as chaperone 'foldases' that are distinct from chaperone' holdases' that provide high affinity binding platform for unfolded proteins and prevent their aggregation specifically under stress conditions. Ribosome, the cellular protein synthesis machine can act as a foldase chaperone that can bind unfolded proteins and release them in folding competent state. The peptidyl transferase center (PTC located in the domain V of the 23S rRNA of Escherichia coli ribosome (bDV RNA is the chaperoning center of the ribosome. It has been proposed that via specific interactions between the RNA and refolding proteins, the chaperone provides information for the correct folding of unfolded polypeptide chains. RESULTS: We demonstrate using Escherichia coli ribosome and variants of its domain V RNA that the ribosome can bind to partially folded intermediates of bovine carbonic anhydrase II (BCAII and lysozyme and suppress aggregation during their refolding. Using mutants of domain V RNA we demonstrate that the time for which the chaperone retains the bound protein is an important factor in determining its ability to suppress aggregation and/or support reactivation of protein. CONCLUSION: The ribosome can behave like a 'holdase' chaperone and has the ability to bind and hold back partially folded intermediate states of proteins from participating in the aggregation process. Since the ribosome is an essential organelle that is present in large numbers in all living cells, this ability of the ribosome provides an energetically inexpensive way to suppress cellular aggregation. Further, this ability of the ribosome might also be crucial in the context that the ribosome is one of the first chaperones to be encountered by a large nascent polypeptide chains that have a tendency to form partially folded intermediates immediately following their synthesis.

  13. Synthesis of sp3-rich scaffolds for molecular libraries through complexity-generating cascade reactions

    DEFF Research Database (Denmark)

    Flagstad, Thomas; Min, Geanna; Bonnet, K.

    2016-01-01

    An efficient strategy for the synthesis of complex small molecules from simple building blocks is presented. Key steps of the strategy include tandem Petasis and Diels–Alder reactions, and divergent complexity-generating cyclization cascades from a key dialdehyde intermediate. The methodology...

  14. A General Strategy for Nanohybrids Synthesis via Coupled Competitive Reactions Controlled in a Hybrid Process

    OpenAIRE

    Wang, Rongming; Yang, Wantai; Song, Yuanjun; Shen, Xiaomiao; Wang, Junmei; Zhong, Xiaodi; Li, Shuai; Song, Yujun

    2015-01-01

    A new methodology based on core alloying and shell gradient-doping are developed for the synthesis of nanohybrids, realized by coupled competitive reactions, or sequenced reducing-nucleation and co-precipitation reaction of mixed metal salts in a microfluidic and batch-cooling process. The latent time of nucleation and the growth of nanohybrids can be well controlled due to the formation of controllable intermediates in the coupled competitive reactions. Thus, spatiotemporal-resolved synthesi...

  15. Microwave – assisted reduction of racemic intermediates potential immunosuppressant

    Directory of Open Access Journals (Sweden)

    Wender A. Silva

    2012-06-01

    Full Text Available Immunosuppressant are drugs that reduce the immune response, as important in the treatment of autoimmune diseases and rejection attenuators in organ transplants, the structural point of view generally have a high complexity. Within this context it is indispensable structural simplifications, new molecules are proposed with potential action on a stage is a necessary, reduction system α,β-unsaturated specifically, chalcone, to their respective alcohol saturated. Therefore, a new method was developed for microwave assisted subsequently coupling to other fragments to the total synthesis of the novel compounds.

  16. Study of Chemical Intermediates by Means of ATR-IR Spectroscopy and Hybrid Hard- and Soft-Modelling Multivariate Curve Resolution-Alternating Least Squares

    Directory of Open Access Journals (Sweden)

    Junxiu Ma

    2017-01-01

    Full Text Available 3,5-Diamino-1,2,4-triazole (DAT became a significant energetic materials intermediate, and the study of its reaction mechanism has fundamental significance in chemistry. The aim of this study is to investigate the ability of online attenuated total reflection infrared (ATR-IR spectroscopy combined with the novel approach of hybrid hard- and soft-modelling multivariate curve resolution-alternating least squares (HS-MCR analysis to monitor and detect changes in structural properties of compound during 3,5-diamino-1,2,4-triazole (DAT synthesis processes. The subspace comparison method (SCM was used to obtain the principal components number, and then the pure IR spectra of each substance were obtained by independent component analysis (ICA and HS-MCR. The extent of rotation ambiguity was estimated from the band boundaries of feasible solutions calculated using the MCR-BANDS procedure. There were five principal components including two intermediates in the process in the results. The reaction rate constants of DAT formation reaction were also obtained by HS-MCR. HS-MCR was used to analyze spectroscopy data in chemical synthesis process, which not only increase the information domain but also reduce the ambiguities of the obtained results. This study provides the theoretical basis for the optimization of synthesis process and technology of energetic materials and provides a strong technical support of research and development of energy material with extraordinary damage effects.

  17. Study of Chemical Intermediates by Means of ATR-IR Spectroscopy and Hybrid Hard- and Soft-Modelling Multivariate Curve Resolution-Alternating Least Squares.

    Science.gov (United States)

    Ma, Junxiu; Qi, Juan; Gao, Xinyu; Yan, Chunhua; Zhang, Tianlong; Tang, Hongsheng; Li, Hua

    2017-01-01

    3,5-Diamino-1,2,4-triazole (DAT) became a significant energetic materials intermediate, and the study of its reaction mechanism has fundamental significance in chemistry. The aim of this study is to investigate the ability of online attenuated total reflection infrared (ATR-IR) spectroscopy combined with the novel approach of hybrid hard- and soft-modelling multivariate curve resolution-alternating least squares (HS-MCR) analysis to monitor and detect changes in structural properties of compound during 3,5-diamino-1,2,4-triazole (DAT) synthesis processes. The subspace comparison method (SCM) was used to obtain the principal components number, and then the pure IR spectra of each substance were obtained by independent component analysis (ICA) and HS-MCR. The extent of rotation ambiguity was estimated from the band boundaries of feasible solutions calculated using the MCR-BANDS procedure. There were five principal components including two intermediates in the process in the results. The reaction rate constants of DAT formation reaction were also obtained by HS-MCR. HS-MCR was used to analyze spectroscopy data in chemical synthesis process, which not only increase the information domain but also reduce the ambiguities of the obtained results. This study provides the theoretical basis for the optimization of synthesis process and technology of energetic materials and provides a strong technical support of research and development of energy material with extraordinary damage effects.

  18. Bridgehead enolate or bridgehead organolithium? DFT calculations provide insights into a difficult bridgehead substitution reaction in the synthesis of the polycyclic polyprenylated acylphloroglucinol (PPAP) nemorosone.

    Science.gov (United States)

    Hayes, Christopher J; Simpkins, Nigel S

    2013-12-28

    A computational study (B3LYP), of the metallation of a bridged ketone, an important step in the synthesis of a polycyclic polyprenylated acylphloroglucinol (PPAP), nemorosone, shows three energetically distinct structural possibilities for the lithiated intermediate. These findings, along with observations of the reactivity of the intermediates in bridgehead substitutions, suggest that different intermediates may be formed depending upon the type of process used for lithiation.

  19. Haber Process for Ammonia Synthesis

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 16; Issue 12. Haber Process for Ammonia Synthesis. Jayant M Modak. Volume 16 Issue 12 December 2011 pp 1159-1167. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/016/12/1159-1167. Keywords.

  20. Fluorous Parallel Synthesis of A Hydantoin/Thiohydantoin Library

    OpenAIRE

    Lu, Yimin; Zhang, Wei

    2005-01-01

    Fluorous tagging strategy is applied to solution-phase parallel synthesis of a library containing hydantoin and thiohydantoin analogs. Two perfluoroalkyl (Rf)-tagged α-amino esters each react with 6 aromatic aldehydes under reductive amination conditions. Twelve amino esters then each react with 10 isocyanates and isothiocyanates in parallel. The resulting 120 ureas and thioureas undergo spontaneous cyclization to form the corresponding hydantoins and thiohydantoins. The intermediate and fina...

  1. Exploring the chemical kinetics of partially oxidized intermediates by combining experiments, theory, and kinetic modeling.

    Science.gov (United States)

    Hoyermann, Karlheinz; Mauß, Fabian; Olzmann, Matthias; Welz, Oliver; Zeuch, Thomas

    2017-07-19

    Partially oxidized intermediates play a central role in combustion and atmospheric chemistry. In this perspective, we focus on the chemical kinetics of alkoxy radicals, peroxy radicals, and Criegee intermediates, which are key species in both combustion and atmospheric environments. These reactive intermediates feature a broad spectrum of chemical diversity. Their reactivity is central to our understanding of how volatile organic compounds are degraded in the atmosphere and converted into secondary organic aerosol. Moreover, they sensitively determine ignition timing in internal combustion engines. The intention of this perspective article is to provide the reader with information about the general mechanisms of reactions initiated by addition of atomic and molecular oxygen to alkyl radicals and ozone to alkenes. We will focus on critical branching points in the subsequent reaction mechanisms and discuss them from a consistent point of view. As a first example of our integrated approach, we will show how experiment, theory, and kinetic modeling have been successfully combined in the first infrared detection of Criegee intermediates during the gas phase ozonolysis. As a second example, we will examine the ignition timing of n-heptane/air mixtures at low and intermediate temperatures. Here, we present a reduced, fuel size independent kinetic model of the complex chemistry initiated by peroxy radicals that has been successfully applied to simulate standard n-heptane combustion experiments.

  2. The use of intermediate endpoints in the design of type 1 diabetes prevention trials.

    Science.gov (United States)

    Krischer, Jeffrey P

    2013-09-01

    This paper presents a rationale for the selection of intermediate endpoints to be used in the design of type 1 diabetes prevention clinical trials. Relatives of individuals diagnosed with type 1 diabetes were enrolled on the TrialNet Natural History Study and screened for diabetes-related autoantibodies. Those with two or more such autoantibodies were analysed with respect to increased HbA1c, decreased C-peptide following an OGTT, or abnormal OGTT values as intermediate markers of disease progression. Over 2 years, a 10% increase in HbA1c, and a 20% or 30% decrease in C-peptide from baseline, or progression to abnormal OGTT, occurred with a frequency between 20% and 41%. The 3- to 5-year risk of type 1 diabetes following each intermediate endpoint was high, namely 47% to 84%. The lower the incidence of the endpoint being reached, the higher the risk of diabetes. A diabetes prevention trial using these intermediate endpoints would require a 30% to 50% smaller sample size than one using type 1 diabetes as the endpoint. The use of an intermediate endpoint in diabetes prevention is based on the generally held view of disease progression from initial occurrence of autoantibodies through successive immunological and metabolic changes to manifest type 1 diabetes. Thus, these markers are suitable for randomised phase 2 trials, which can more rapidly screen promising new therapies, allowing them to be subsequently confirmed in definitive phase 3 trials.

  3. MHD intermediate shock discontinuities: Pt. 1

    International Nuclear Information System (INIS)

    Kennel, C.F.; Blandford, R.D.; Coppi, P.

    1989-01-01

    Recent numerical investigations have focused attention once more on the role of intermediate shocks in MHD. Four types of intermediate shock are identified using a graphical representation of the MHD Rankine-Hugoniot conditions. This same representation can be used to exhibit the close relationship of intermediate shocks to switch-on shocks and rotational discontinuities. The conditions under which intermediate discontinuities can be found are elucidated. The variations in velocity, pressure, entropy and magnetic-field jumps with upstream parameters in intermediate shocks are exhibited graphically. The evolutionary arguments traditionally advanced against intermediate shocks may fail because the equations of classical MHD are not strictly hyperbolic. (author)

  4. Nazarov cyclization initiated by peracid oxidation: the total synthesis of (+/-)-rocaglamide.

    Science.gov (United States)

    Malona, John A; Cariou, Kevin; Frontier, Alison J

    2009-06-10

    The total syntheses of aglafolin, rocagloic acid, and rocaglamide using Nazarov cyclization are described. Generation of the necessary oxyallyl cation intermediate was accomplished via peracid oxidation of an allenol ether to generate an unusual oxycarbenium ion species that undergoes cyclization. The synthesis is efficient, highly diastereoselective, and strategically distinct from previous syntheses of rocaglamide.

  5. Synthesis of [14α-methyl-3H]-24,25-dihydrolanosterol

    International Nuclear Information System (INIS)

    DeKeczer, S.; Kertesz, D.; Parnes, H.

    1993-01-01

    We describe the first synthesis of isomerically pure title compound (6) at high specific activity. This required the development of a convenient, regiospecific synthesis of the δ 8(9) -15-ketone and subsequent alkylation with methyl-[ 3 H 3 ]iodide. A key step in our procedure was the use of an electrochemical reduction of the intermediate [14α-methyl- 3 H]-15-oxo-dihydrolanosterol. This process was effected cleanly and in high yield to give (6), an important assay tool in the search for cholesterol lowering agents. This approach was found to be significantly superior to the Wolff-Kishner reduction of the corresponding 3-benzoate. (Author)

  6. The synthesis and chemiluminescence of a stable 1,2-dioxetane : an organic chemistry laboratory experiment

    NARCIS (Netherlands)

    Meijer, E.W.; Wynberg, H.

    1982-01-01

    An expt. for the synthesis of adamantylideneadamantane-1,2-dioxetane illustrating the concepts of the singlet O reaction and chemiluminescence, is described. All intermediates and products can be identified by undergraduate students using routine spectroscopic anal. [on SciFinder (R)

  7. Integrating multi-view transmission system into MPEG-21 stereoscopic and multi-view DIA (digital item adaptation)

    Science.gov (United States)

    Lee, Seungwon; Park, Ilkwon; Kim, Manbae; Byun, Hyeran

    2006-10-01

    solve for the former, IVR (intermediate view reconstruction) is employed for smooth transition between two stereoscopic view sequences. As well, a disparity adjustment scheme is used for the latter. Finally, from the implementation of testbed and the experiments, we can show the valuables and possibilities of our system.

  8. Synthesis of sulfonimidamides from sulfinamides by oxidation with N-chlorosuccinimide

    Directory of Open Access Journals (Sweden)

    Bolm Carsten

    2007-09-01

    Full Text Available Abstract Background The synthesis of sulfonimidamides involves the nucleophilic substitution of a sulfonimidoyl chloride with an amine. However, only four chlorinating systems have been reported for the preparation of the sulfonimidoyl chloride intermediates. Whereas some of them have shown a rather limited substrate spectrum, the most versatile and commonly used tert-butyl hypochlorite is known to be explosive. To establish alternative methods for the synthesis of these molecules is therefore desirable. Results The preparation of various p-tolylsulfonimidamides through the reaction of the corresponding N-protected p-tolylsulfinamides and a number of amines in the presence of N-chlorosuccinimide was achieved at room temperature in 50–97% yield. Conclusion A convenient alternative procedure for the synthesis of sulfonimidamides from sulfinamides and various amines and sulfonamides using N-chlorosuccinimide as halogenating agent has been developed.

  9. A concise synthesis of benzimidazoles via the microwave-assisted one-pot batch reaction of amino acids up to a 10-g scale.

    Science.gov (United States)

    Peng, Pai; Xiong, Jin-Feng; Mo, Guang-Zhen; Zheng, Jia-Li; Chen, Ren-Hong; Chen, Xiao-Yun; Wang, Zhao-Yang

    2014-10-01

    An efficient method for the synthesis of aminomethyl benzimidazoles is developed by using a one-pot batch reaction between amino acids and o-phenylenediamines. This reaction proceeds smoothly in an unmodified household microwave oven, even though scale-up is to 10 g. A desirable method for the quick synthesis of benzimidazoles, which are used as a kind of important intermediates in drug synthesis, is provided by the scale-up utilization of amino acid resource.

  10. Intermediate tree cover can maximize groundwater recharge in the seasonally dry tropics

    Science.gov (United States)

    Ilstedt, U.; Bargués Tobella, A.; Bazié, H. R.; Bayala, J.; Verbeeten, E.; Nyberg, G.; Sanou, J.; Benegas, L.; Murdiyarso, D.; Laudon, H.; Sheil, D.; Malmer, A.

    2016-01-01

    Water scarcity contributes to the poverty of around one-third of the world’s people. Despite many benefits, tree planting in dry regions is often discouraged by concerns that trees reduce water availability. Yet relevant studies from the tropics are scarce, and the impacts of intermediate tree cover remain unexplored. We developed and tested an optimum tree cover theory in which groundwater recharge is maximized at an intermediate tree density. Below this optimal tree density the benefits from any additional trees on water percolation exceed their extra water use, leading to increased groundwater recharge, while above the optimum the opposite occurs. Our results, based on groundwater budgets calibrated with measurements of drainage and transpiration in a cultivated woodland in West Africa, demonstrate that groundwater recharge was maximised at intermediate tree densities. In contrast to the prevailing view, we therefore find that moderate tree cover can increase groundwater recharge, and that tree planting and various tree management options can improve groundwater resources. We evaluate the necessary conditions for these results to hold and suggest that they are likely to be common in the seasonally dry tropics, offering potential for widespread tree establishment and increased benefits for hundreds of millions of people. PMID:26908158

  11. Oxidase catalysis via aerobically generated hypervalent iodine intermediates

    Science.gov (United States)

    Maity, Asim; Hyun, Sung-Min; Powers, David C.

    2018-02-01

    The development of sustainable oxidation chemistry demands strategies to harness O2 as a terminal oxidant. Oxidase catalysis, in which O2 serves as a chemical oxidant without necessitating incorporation of oxygen into reaction products, would allow diverse substrate functionalization chemistry to be coupled to O2 reduction. Direct O2 utilization suffers from intrinsic challenges imposed by the triplet ground state of O2 and the disparate electron inventories of four-electron O2 reduction and two-electron substrate oxidation. Here, we generate hypervalent iodine reagents—a broadly useful class of selective two-electron oxidants—from O2. This is achieved by intercepting reactive intermediates of aldehyde autoxidation to aerobically generate hypervalent iodine reagents for a broad array of substrate oxidation reactions. The use of aryl iodides as mediators of aerobic oxidation underpins an oxidase catalysis platform that couples substrate oxidation directly to O2 reduction. We anticipate that aerobically generated hypervalent iodine reagents will expand the scope of aerobic oxidation chemistry in chemical synthesis.

  12. Discovery of competing anaerobic and aerobic pathways in umpolung amide synthesis allows for site-selective amide 18O-labeling

    Science.gov (United States)

    Shackleford, Jessica P.; Shen, Bo; Johnston, Jeffrey N.

    2012-01-01

    The mechanism of umpolung amide synthesis was probed by interrogating potential sources for the oxygen of the product amide carbonyl that emanates from the α-bromo nitroalkane substrate. Using a series of 18O-labeled substrates and reagents, evidence is gathered to advance two pathways from the putative tetrahedral intermediate. Under anaerobic conditions, a nitro-nitrite isomerization delivers the amide oxygen from nitro oxygen. The same homolytic nitro-carbon fragmentation can be diverted by capture of the carbon radical intermediate with oxygen gas (O2) to deliver the amide oxygen from O2. This understanding was used to develop a straightforward protocol for the preparation of 18O-labeled amides in peptides by simply performing the umpolung amide synthesis reaction under an atmosphere of . PMID:22184227

  13. Thermochemistry and micro-kinetic analysis of methanol synthesis on ZnO (0001)

    DEFF Research Database (Denmark)

    Medford, Andrew James; Sehested, Jens; Rossmeisl, Jan

    2014-01-01

    In this work, we examine the thermochemistry of methanol synthesis intermediates using density functional theory (DFT) and analyze the methanol synthesis reaction network using a steady-state micro-kinetic model. The energetics for methanol synthesis over Zn-terminated ZnO (0001) are obtained from...... DFT calculations using the RPBE and BEEF-vdW functionals. The energies obtained from the two functionals are compared and it is determined that the BEEF-vdW functional is more appropriate for the reaction. The BEEF-vdW energetics are used to construct surface phase diagrams as a function of CO, H2O......, and H2 chemical potentials. The computed binding energies along with activation barriers from literature are used as inputs for a mean-field micro-kinetic model for methanol synthesis including the CO and CO2 hydrogenation routes and the water–gas shift reaction. The kinetic model is used to investigate...

  14. Solid‐Phase Synthesis of Structurally Diverse Heterocycles by an Amide–Ketone Condensation/N‐Acyliminium Pictet–Spengler Sequence

    DEFF Research Database (Denmark)

    Komnatnyy, Vitaly V.; Givskov, Michael Christian; Nielsen, Thomas Eiland

    2012-01-01

    An efficient approach for the solid‐phase synthesis of structurally diverse heterocyclic compounds is presented. Under acidic reaction conditions, peptidic levulinamides undergo intramolecular ketone–amide condensation reactions to form cyclic N‐acyliminium intermediates. In the presence...

  15. Intertextuality, Transcoding and Intermediality: Tools for an Interartistic Education

    Directory of Open Access Journals (Sweden)

    Alessandra Anceschi

    2015-12-01

    Full Text Available In education, the activation of interdisciplinary strategies still represents an important perspective to support and compare different “views on the world”. In particular, in Arts education (such as Music and Arts, currently the only ones officially recognized in the curriculum the opening of their epistemic frames becomes imperative to consider the aesthetic experience in its purest form: the experience that can break boundaries and amplify the relationship between the senses. By identifying common and divergent features in concepts such as intertextuality, transcoding and intermediality, the paper tries to provide tools in order to activate and interpret the relationship among the arts that can be considered also from an interdisciplinary educational perspective.

  16. Information acquisition and financial intermediation

    OpenAIRE

    Boyarchenko, Nina

    2012-01-01

    This paper considers the problem of information acquisition in an intermediated market, where the specialists have access to superior technology for acquiring information. These informational advantages of specialists relative to households lead to disagreement between the two groups, changing the shape of the intermediation-constrained region of the economy and increasing the frequency of periods when the intermediation constraint binds. Acquiring the additional information is, however, cost...

  17. Prebiotic Peptide (Amide) Bond Synthesis Accelerated by Glycerol and Bicarbonate Under Neutral to Alkaline Dry-Down Conditions

    Science.gov (United States)

    Forsythe, J. G.; Weber, A. L.

    2017-01-01

    Past studies of prebiotic peptide bond synthesis have generally been carried out in the acidic to neutral pH range [1, 2]. Here we report a new process for peptide bond (amide) synthesis in the neutral to alkaline pH range that involves simple dry-down heating of amino acids in the presence of glycerol and bicarbonate. Glycerol was included in the reaction mixture as a solvent and to provide hydroxyl groups for possible formation of ester intermediates previously implicated in peptide bond synthesis under acidic to neutral conditions [1]. Bicarbonate was added to raise the reaction pH to 8-9.

  18. Divide and conquer: intermediate levels of population fragmentation maximize cultural accumulation.

    Science.gov (United States)

    Derex, Maxime; Perreault, Charles; Boyd, Robert

    2018-04-05

    Identifying the determinants of cumulative cultural evolution is a key issue in the interdisciplinary field of cultural evolution. A widely held view is that large and well-connected social networks facilitate cumulative cultural evolution because they promote the spread of useful cultural traits and prevent the loss of cultural knowledge through factors such as drift. This view stems from models that focus on the transmission of cultural information, without considering how new cultural traits actually arise. In this paper, we review the literature from various fields that suggest that, under some circumstances, increased connectedness can decrease cultural diversity and reduce innovation rates. Incorporating this idea into an agent-based model, we explore the effect of population fragmentation on cumulative culture and show that, for a given population size, there exists an intermediate level of population fragmentation that maximizes the rate of cumulative cultural evolution. This result is explained by the fact that fully connected, non-fragmented populations are able to maintain complex cultural traits but produce insufficient variation and so lack the cultural diversity required to produce highly complex cultural traits. Conversely, highly fragmented populations produce a variety of cultural traits but cannot maintain complex ones. In populations with intermediate levels of fragmentation, cultural loss and cultural diversity are balanced in a way that maximizes cultural complexity. Our results suggest that population structure needs to be taken into account when investigating the relationship between demography and cumulative culture.This article is part of the theme issue 'Bridging cultural gaps: interdisciplinary studies in human cultural evolution'. © 2018 The Author(s).

  19. Total Synthesis of Zoanthamine Alkaloids, Part 2. Construction of the C1-C5, C6-C10 and C11-C24 Fragments of Zoanthamine

    DEFF Research Database (Denmark)

    Tanner, David Ackland; Tedenborg, Lars; Somfai, Peter

    1997-01-01

    This paper describes the construction of three key intermediates for a projected total synthesis of the marine alkaloid zoanthamine. These building blocks, corresponding to the C1-C5, C6-C10 and C11-C24 fragments of the target molecule, are synthesised efficiently form (R)-hydroxymethyl-butyrolac......This paper describes the construction of three key intermediates for a projected total synthesis of the marine alkaloid zoanthamine. These building blocks, corresponding to the C1-C5, C6-C10 and C11-C24 fragments of the target molecule, are synthesised efficiently form (R...

  20. Depth-based Multi-View 3D Video Coding

    DEFF Research Database (Denmark)

    Zamarin, Marco

    techniques are used to extract dense motion information and generate improved candidate side information. Multiple candidates are merged employing multi-hypothesis strategies. Promising rate-distortion performance improvements compared with state-of-the-art Wyner-Ziv decoders are reported, both when texture......-view video. Depth maps are typically used to synthesize the desired output views, and the performance of view synthesis algorithms strongly depends on the accuracy of depth information. In this thesis, novel algorithms for efficient depth map compression in MVD scenarios are proposed, with particular focus...... on edge-preserving solutions. In a proposed scheme, texture-depth correlation is exploited to predict surface shapes in the depth signal. In this way depth coding performance can be improved in terms of both compression gain and edge-preservation. Another solution proposes a new intra coding mode targeted...

  1. Synthesis of (R-Dihydropyridones as Key Intermediates for an Efficient Access to Piperidine Alkaloids

    Directory of Open Access Journals (Sweden)

    Serkos A Haroutounian

    2007-04-01

    Full Text Available The efficient transformation of D-glucal to (2R-hydroxymethyldihydro-pyridinone 5 in seven steps and 35 % overall yield is reported. Dihydropyridone 5 constitutes a versatile chiral building block for the synthesis of various piperidine alkaloids. In this regard, 5 was converted to piperidinol 13 and piperidinone 15, that may be further elaborated for the syntheses of (+-desoxoprosophylline (1 and deoxymannojirimycin (3 or D-mannolactam (4, respectively.

  2. A Single Enzyme Transforms a Carboxylic Acid into a Nitrile through an Amide Intermediate.

    Science.gov (United States)

    Nelp, Micah T; Bandarian, Vahe

    2015-09-01

    The biosynthesis of nitriles is known to occur through specialized pathways involving multiple enzymes; however, in bacterial and archeal biosynthesis of 7-deazapurines, a single enzyme, ToyM, catalyzes the conversion of the carboxylic acid containing 7-carboxy-7-deazaguanine (CDG) into its corresponding nitrile, 7-cyano-7-deazaguanine (preQ0 ). The mechanism of this unusual direct transformation was shown to proceed via the adenylation of CDG, which activates it to form the newly discovered amide intermediate 7-amido-7-deazaguanine (ADG). This is subsequently dehydrated to form the nitrile in a process that consumes a second equivalent of ATP. The authentic amide intermediate is shown to be chemically and kinetically competent. The ability of ToyM to activate two different substrates, an acid and an amide, accounts for this unprecedented one-enzyme catalysis of nitrile synthesis, and the differential rates of these two half reactions suggest that this catalytic ability is derived from an amide synthetase that gained a new function. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Solution-phase parallel synthesis of aryloxyimino amides via a novel multicomponent reaction among aromatic (Z)-chlorooximes, isocyanides, and electron-deficient phenols.

    Science.gov (United States)

    Mercalli, Valentina; Giustiniano, Mariateresa; Del Grosso, Erika; Varese, Monica; Cassese, Hilde; Massarotti, Alberto; Novellino, Ettore; Tron, Gian Cesare

    2014-11-10

    A library of 41 aryloxyimino amides was prepared via solution phase parallel synthesis by extending the multicomponent reaction of (Z)-chlorooximes and isocyanides to the use of electron-deficient phenols. The resulting aryloxyiminoamide derivatives can be used as intermediates for the synthesis of benzo[d]isoxazole-3-carboxamides, dramatically reducing the number of synthetic steps required by other methods reported in literature.

  4. Synthesis of naturally occurring iminosugars from D-fructose by the use of a zinc-mediated fragmentation reaction

    DEFF Research Database (Denmark)

    Lauritsen, Anne; Madsen, Robert

    2006-01-01

    A short synthesis of 1,4-dideoxy-1,4-imino-D-arabinitol (DAB) and a formal synthesis of australine are described. In both cases, D-fructose is employed as the starting material and converted into a protected methyl 6-deoxy-6-iodo-furanoside. Zinc-mediated fragmentation produces an unsaturated...... ketone which serves as a key building block for both syntheses. Ozonolysis, reductive amination with benzylamine and deprotection affordfs 1,4-dideoxy-1,4-imino-D-arabinitol in only 7 steps and 11% overall yield from D-fructose. Alternatively, reductive amination with homoallylamine, ring......-closing metathesis and protecting group manipulations give rise to an intermediate which can be converted into australine in 3 steps. The intermediate is prepared by two different strategies both of which use a total of 9 steps. The first strategy utilizes benzyl ethers for protection of fructose while the second...

  5. Synthesis of deuterium-labeled felbamate from diethyl phenylmalonate

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Y.M.; Kucharczyk, N.; Sofia, R.D.

    1986-07-01

    A synthesis of the antiepileptic drug, felbamate-d/sub 4/ (2-phenyl-1,3-propanediol-1,1,3,3-d/sub 4/ dicarbamate), starting from diethyl phenylmalonic acid ester and lithium aluminum deuteride was developed. The procedure has three steps from the starting material to felbamate-d/sub 4/ via the intermediate, 2-phenyl-1,3-propanediol-1,1,3,3-d/sub 4/. The final overall yield was 44%. The isotope purity was 99.2%.

  6. One-Pot Synthesis of Cyclopropane-Fused Cyclic Amidines: An Oxidative Carbanion Cyclization.

    Science.gov (United States)

    Veeranna, Kirana Devarahosahalli; Das, Kanak Kanti; Baskaran, Sundarababu

    2017-12-18

    A novel and efficient one-pot method has been developed for the synthesis of cyclopropane-fused bicyclic amidines on the basis of a CuBr 2 -mediated oxidative cyclization of carbanions. The usefulness of this unique multicomponent strategy has been demonstrated by the use of a wide variety of substrates to furnish novel cyclopropane-containing amidines with a quaternary center in very good yields. This ketenimine-based approach provides straightforward access to biologically active and pharmaceutically important 3-azabicyclo[n.1.0]alkane frameworks under mild conditions. The synthetic power of this methodology is exemplified in the concise synthesis of the pharmaceutically important antidepressant drug candidate GSK1360707 and key intermediates for the synthesis of amitifadine, bicifadine, and narlaprevir. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Formation Mechanism of Spherical TiC in Ni-Ti-C System during Combustion Synthesis.

    Science.gov (United States)

    Zhu, Guoliang; Wang, Wei; Wang, Rui; Zhao, Chuanbao; Pan, Weitao; Huang, Haijun; Du, Dafan; Wang, Donghong; Shu, Da; Dong, Anping; Sun, Baode; Jiang, Sheng; Pu, Yilong

    2017-08-29

    The formation mechanism of TiC particles in a Ni-Ti-C system were revealed by using differential thermal analysis (DTA), XRD, and SEM to identify the reaction products in different temperature ranges. The results indicated that the synthesis mechanism of TiC in Ni-Ti-C system was complex; several reactions were involved in the combustion synthesis of TiC-Ni composite. The Ni-Ti intermediate phases play important roles during the formation of TiC. Moreover, the influence of heating rate on the size range of TiC was also discussed.

  8. Probing force-induced unfolding intermediates of a single staphylococcal nuclease molecule and the effect of ligand binding

    International Nuclear Information System (INIS)

    Ishii, Takaaki; Murayama, Yoshihiro; Katano, Atsuto; Maki, Kosuke; Kuwajima, Kunihiro; Sano, Masaki

    2008-01-01

    Single-molecule manipulation techniques have given experimental access to unfolding intermediates of proteins that are inaccessible in conventional experiments. A detailed characterization of the intermediates is a challenging problem that provides new possibilities for directly probing the energy landscape of proteins. We investigated single-molecule mechanical unfolding of a small globular protein, staphylococcal nuclease (SNase), using atomic force microscopy. The unfolding trajectories of the protein displayed sub-molecular and stochastic behavior with typical lengths corresponding to the size of the unfolded substructures. Our results support the view that the single protein unfolds along multiple pathways as suggested in recent theoretical studies. Moreover, we found the drastic change, caused by the ligand and inhibitor bindings, in the mechanical unfolding dynamics

  9. Discourses and Models of Intermediality

    OpenAIRE

    Schröter, Jens

    2011-01-01

    In his article "Discourses and Models of Intermediality" Jens Schröter discusses the question as to what relations do different discourses pose between different "media." Schröter identifies four models of discourse: 1) synthetic intermediality: a "fusion" of different media to super-media, a model with roots in the Wagnerian concept of Gesamtkunstwerk with political connotations, 2) formal (or transmedial) intermediality: a concept based on formal structures not "specific" to one medium but ...

  10. Synthesis of tritium-labelled (-)-U50,488, a selective kappa opioid agonist

    International Nuclear Information System (INIS)

    Thurkauf, A.; Costa, B. de; Rice, K.C.

    1989-01-01

    The preparation of 3 H labelled (-)-trans-3,4-dichloro-N-methyl-N[2-(1-pyrrolidinyl) cyclohexyl]benzeneacetamide (U50,488) in four steps from N-methylcyclohexylaziridine is described. The synthesis of the pharmacologically active (-) isomer of U50, 488 was accomplished through the resolution of the intermediate 2-[1-(3-pyrrolinyl)]-N-methylcyclohexylamine using (+)-mandelic acid. (Author)

  11. Synthesis and Antibacterial Activity of 1,3,4-Oxadiazole and 1,2,4 ...

    African Journals Online (AJOL)

    NJD

    The antibacterial activities of the starting materials, the synthetic intermediates and the products were tested and are reported below. 2. Results and Discussion. 2.1. Synthesis. The final products 4, 6, 8 and 9 have been synthesized by a common pathway as summarized in Scheme 1. The methyl salicylate 2 was synthesized ...

  12. Synthesis of selective extractor for minor actinide elements

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Seung [Konyang University, Nonsan (Korea); Cho, Moon Hwan [Kangwon National University, Chunchon (Korea)

    1998-04-01

    To selectively co-separate the lanthanide and actinide elements (MA) such as Am or Cm ion from radioactive waste, synthesis of diamide derivatives has been accomplished. In addition, picoline amide derivatives were also synthesized for selectively separate the minor actinide elements from lanthanide elements. The content of research has don are as follows: (1) synthesis of diamide as co-extractant (2) introduction of n-tetradecyl to increase the lipophilicity (3) Picolyl chloride, intermediate of the final product, was synthesized by improved method rather than reported method. (4) The length of alkyl side chain was adjusted to increase the lipophilicity of free ligand and its derivatives able to selectively separate the actinide metal from lanthanide metal ions was successfully synthesized and determined their purity by analytical instruments. (author). 12 refs., 28 figs.

  13. Time-resolved resonance Raman spectroscopy of intermediates of bacteriorhodopsin: The bK(590) intermediate.

    Science.gov (United States)

    Terner, J; Hsieh, C L; Burns, A R; El-Sayed, M A

    1979-07-01

    We have combined microbeam and flow techniques with computer subtraction methods to obtain the resonance Raman spectrum of the short lived batho-intermediate (bK(590)) of bacteriorhodopsin. Comparison of the spectra obtained in (1)H(2)O and (2)H(2)O, as well as the fact that the bK(590) intermediate shows large optical red shifts, suggests that the Schiff base linkage of this intermediate is protonated. The fingerprint region of the spectrum of bK(590), sensitive to the isomeric configuration of the retinal chromophore, does not resemble the corresponding region of the parent bR(570) form. The resonance Raman spectrum of bK(590) as well as the spectra of all of the other main intermediates in the photoreaction cycle of bacteriorhodopsin are discussed and compared with resonance Raman spectra of published model compounds.

  14. Role of Intermediate Filaments in Vesicular Traffic

    Directory of Open Access Journals (Sweden)

    Azzurra Margiotta

    2016-04-01

    Full Text Available Intermediate filaments are an important component of the cellular cytoskeleton. The first established role attributed to intermediate filaments was the mechanical support to cells. However, it is now clear that intermediate filaments have many different roles affecting a variety of other biological functions, such as the organization of microtubules and microfilaments, the regulation of nuclear structure and activity, the control of cell cycle and the regulation of signal transduction pathways. Furthermore, a number of intermediate filament proteins have been involved in the acquisition of tumorigenic properties. Over the last years, a strong involvement of intermediate filament proteins in the regulation of several aspects of intracellular trafficking has strongly emerged. Here, we review the functions of intermediate filaments proteins focusing mainly on the recent knowledge gained from the discovery that intermediate filaments associate with key proteins of the vesicular membrane transport machinery. In particular, we analyze the current understanding of the contribution of intermediate filaments to the endocytic pathway.

  15. Intermediality: Bridge to Critical Media Literacy.

    Science.gov (United States)

    Pailliotet, Ann Watts; Semali, Ladislaus; Rodenberg, Rita K.; Giles, Jackie K.; Macaul, Sherry L.

    2000-01-01

    Defines "intermediality" as the ability to critically read and write with and across varied symbol systems. Relates it to critical media literacy. Offers rationales for teaching critical media literacy in general, and intermedial instruction in particular. Identifies seven guiding intermedial elements: theory, texts, processes, contexts,…

  16. Enhanced dipicolinic acid production during the stationary phase in Bacillus subtilis by blocking acetoin synthesis.

    Science.gov (United States)

    Toya, Yoshihiro; Hirasawa, Takashi; Ishikawa, Shu; Chumsakul, Onuma; Morimoto, Takuya; Liu, Shenghao; Masuda, Kenta; Kageyama, Yasushi; Ozaki, Katsuya; Ogasawara, Naotake; Shimizu, Hiroshi

    2015-01-01

    Bacterial bio-production during the stationary phase is expected to lead to a high target yield because the cells do not consume the substrate for growth. Bacillus subtilis is widely used for bio-production, but little is known about the metabolism during the stationary phase. In this study, we focused on the dipicolinic acid (DPA) production by B. subtilis and investigated the metabolism. We found that DPA production competes with acetoin synthesis and that acetoin synthesis genes (alsSD) deletion increases DPA productivity by 1.4-fold. The mutant showed interesting features where the glucose uptake was inhibited, whereas the cell density increased by approximately 50%, resulting in similar volumetric glucose consumption to that of the parental strain. The metabolic profiles revealed accumulation of pyruvate, acetyl-CoA, and the TCA cycle intermediates in the alsSD mutant. Our results indicate that alsSD-deleted B. subtilis has potential as an effective host for stationary-phase production of compounds synthesized from these intermediates.

  17. Time depending assessment of low and intermediate radioactive waste characteristics from Cernavoda NPP

    International Nuclear Information System (INIS)

    Mateescu, S.; Pantazi, D.; Stanciu, M.

    2002-01-01

    Low and intermediate radioactive gaseous, liquid and solid waste produced at Cernavoda Nuclear Power Plant must be well known from the point of view of contained radionuclide activity, during all steps of their processing, storage and transport, to ensure the nuclear safety of radioactive waste management. As in intermediate storage stage, the waste activity changes by radioactive decay and nuclear transmutation, the evolution in time of these sources is necessary to be assessed, for the purpose of biological shielding determination at any time. On the other hand, during the transport of waste package at the repository, the external dose rates must meet the national and international requirements concerning radioactive materials transportation on public roads. In this paper, a calculation methodology for waste characterization based on external exposure rate measurement and on sample analysis results is presented. The time evolution of waste activity, as well as the corresponding shielding at different moments of management process, have been performed using MICROSHIELD-5 code. The spent resins proceeded from clean-up and purification systems and solutions from decontamination have been analyzed. The proposed methodology helps us to assess radiation protection during the handling of low and intermediate - level radioactive waste drums, ensuring safety conditions for the public and environment.(author)

  18. Systematic review of epilepsy self-management interventions integrated with a synthesis of children and young people's views and experiences.

    Science.gov (United States)

    Lewis, Sheila A; Noyes, Jane; Hastings, Richard P

    2015-03-01

    To determine the effectiveness of epilepsy self-management interventions and explore the views and experiences of medication and seizures by children and young people. Experiencing seizures and side-effects from anti-epileptic medicines have negative impacts on children and young people managing their epilepsy. Children commonly experiment with not taking epilepsy medication as prescribed and engage in unhealthy lifestyles. DESIGN/REVIEW METHODS: Mixed-method systematic review with theory development. Cochrane quantitative methods and thematic synthesis of qualitative and survey evidence. Eight databases were searched from earliest dates to July 2013. Nineteen studies were included. Meta-analysis was not possible. Zero of nine intervention studies showed improvement in anti-epilepsy medication adherence. Skill-based behavioural techniques with activities such as role play and goal setting with young people increased epilepsy knowledge and seizure self-management (small effects). Intervention studies were methodologically weak and no studies reported if improvement in self-management was sustained over time. Synthesis of nine qualitative and one mixed-method studies generated six themes encapsulating anti-epilepsy medication and epilepsy effects. There was a lack of fidelity between intervention programme theories and what children and young people found difficult with medication self-management and managing the effects of epilepsy. Children and young people knowingly and/or unknowingly take risks with their epilepsy and give reasoned explanations for doing so. There are no effective interventions to change epilepsy medication adherence behaviours. There is an urgent need for more innovative and individually tailored interventions to address specific challenges to epilepsy self-management as identified by children and young people themselves. © 2014 John Wiley & Sons Ltd.

  19. Probe molecule studies: Active species in alcohol synthesis. Final report, July 1993--July 1994

    Energy Technology Data Exchange (ETDEWEB)

    Blackmond, D.G.; Wender, I.; Oukaci, R.; Wang, Jian

    1994-07-01

    The objectives of this project are to investigate the role(s) of cobalt and copper in constructing the active sites for the formation of higher alcohols from CO/H{sub 2} over the Co-Cu based catalysts by using different reduction treatments and applying selected characterization tools such as TPR, TPD, XRD and XPS as well as to generate mechanistic information on the reaction pathway(s) and key intermediate(s) of higher alcohol synthesis from CO/H{sub 2} over Co-Cu/ZnO catalysts by the approach of in-situ addition of a probe molecule (nitromethane).

  20. Mechanism and microstructural evolution of polyol mediated synthesis of nanostructured M-type SrFe12O19

    International Nuclear Information System (INIS)

    Tenorio Gonzalez, F.N.; Bolarín Miró, A.M.; Sánchez De Jesús, F.; Cortés Escobedo, C.A.; Ammar, S.

    2016-01-01

    The synthesis mechanism of nanostructured M-type strontium hexaferrite SrFe 12 O 19 with high coercivity (5.7 kOe) obtained by a polyol process and annealing is proposed. The results show that the hexaferrite is synthesized through the formation of a complex with diethylene glycol during the hydrolysis and solvation stage, followed by the condensation of magnetite and strontium oxide. The results of the monitoring of the process by X-ray diffraction (XRD) of synthesized powders, magnetization hysteresis loops and micromorphology are presented and discussed. The proposed mechanism suggests the intermediate formation of the magnetite phase, which shows coercivity near zero at room temperature and confirms the nanoscale of the particles. Results of thermogravimetric and differential thermal analysis indicate that this phase is followed by the formation of the hematite phase after a heat treatment up to 543 °C in an oxidizing atmosphere. Finally, the hexagonal phase is obtained after application of annealing at 836 °C through the reaction between hematite and strontium oxide. - Highlights: • SrFe 12 O 19 was successfully obtained by a polyol-assisted synthesis. • Magnetite nanoparticles have been obtained as intermediate phase. • A synthesis mechanism for the growing stage of magnetite is proposed. • A reaction sequence and the synthesis mechanism to obtain hexaferrite is presented.

  1. Synthesis and Antimicrobial Activities of Some New Pyrazoles ...

    African Journals Online (AJOL)

    NICO

    29 antimalarial,30 antimicrobial,31,32 antiviral,33,34 hypoglycaemic,35 anti-HIV activity,36 insecticidal,37 and anti- fungal38 activities. In view of these reports and in continuation of our previous work39 we describe here a facile synthesis of.

  2. Entrepreneurship, Subjectivism, and the Resource-based View

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Klein, Peter G.; Kor, Yasemin Y.

    This paper maintains that the consistent application of subjectivism helps to reconcile contemporary entrepreneurship theory with strategic management research in general, and the resource−based view in particular. The paper synthesizes theoretical insights from Austrian economics and Penrose......'s (1959) resources approach, arguing that entrepreneurship is inherently subjective and firm specific. This new synthesis describes how entrepreneurship is manifested in teams, and is driven by both heterogeneity of managerial mental models and shared team experiences....

  3. Synthesis and characterization of fluorine compounds

    International Nuclear Information System (INIS)

    Martinez Carrillo, M.

    1991-01-01

    The ( 18 F) D-glucose, 2-deoxy fluorine ( 18 FDG) is a radio pharmaceutic that is used in nuclear medicine it is utilized mainly in the glucose metabolism. It allows recently to observe the tumors accumulation and growing. The obtention of this radio pharmaceutic can realize by a nucleophilic or electrophilic process through the use of different fluorinated agents obtained as intermediates for introducing the 18 F radionuclide in a final step of synthesis. The first methods already has been studied in the National Institute of Nuclear Research. The second one which is based this work and it was realized through the reaction of acetyl hypo fluorite (CH 3 COOF) with tri acetyl glucal (TAG) in turn they require the obtention of several fluorated compounds that they serve as intermediates for their obtention so that objective of this work was to find the adequate technique for the obtention of anhydride hydrofluoric acid (HF), KF.2 HF and elemental fluorine so as the design and construction of the systems and equipment used for carry out each one of the reactions. Moreover it was designed the system that will be used for the obtention of acetyl hypo fluoride and the synthesis of composite tetraacetilide 3,4,6 tri-D-glucopyranosil fluoride (TAG-F) for that finally by hydrolysis it was obtained the 2-deoxy fluoride-D-glucose (TAG) in inactive. In this system were realized several preliminary tests. The results are showed in the content of this work also the techniques for compounds characterization were given. (Author)

  4. Direct asymmetric vinylogous aldol reaction of allyl ketones with isatins: Divergent synthesis of 3-hydroxy-2-oxindole derivatives

    KAUST Repository

    Zhu, Bo; Zhang, Wen; Lee, Richmond; Han, Zhiqiang; Yang, Wenguo; Tan, Davin; Huang, Kuo-Wei; Jiang, Zhiyong

    2013-01-01

    6 in 1: The highly enantioselective title reaction is mediated by a bifunctional catalyst and leads to E-configured vinylogous aldol products (see scheme). These products are used as common intermediates in the synthesis of six biologically active 3

  5. Electron-atom scattering at intermediate energies

    International Nuclear Information System (INIS)

    Kingston, A.E.; Walters, H.R.J.

    1982-01-01

    The problems of intermediate energy scattering are approached from the low and high energy ends. At low intermediate energies difficulties associated with the use of pseudostates and correlation terms are discussed, special consideration being given to nonphysical pseudoresonances. Perturbation methods appropriate to high intermediate energies are described and attempts to extend these high energy approximations down to low intermediate energies are studied. It is shown how the importance of electron exchange effects develops with decreasing energy. The problem of assessing the 'effective completeness' of pseudostate sets at intermediate energies is mentioned and an instructive analysis of a 2p pseudostate approximation to elastic e - -H scattering is given. It is suggested that at low energies the Pauli Exclusion Principle can act to hide short range defects in pseudostate approximations. (author)

  6. Pyrole-substituted barbituric derivatives as pharmaceutically significant compounds and intermediates

    International Nuclear Information System (INIS)

    Bijev, A.; Prodanova, P.

    2004-01-01

    Pyrrole- and indolecarbaldehydes are condensed with 5-unsubstituted barbituric acids targeting 16 new heterocyclic structures with a prospective pharmacological profile. So 1H-2-pyrrolecarbaldehyde, diethyl 5-formyl-3-methyl-1H-2,4-pyrroledicarboxylate, ethyl 5-formy 1-2,4-dimethyl-l.fl'-3-pyrrolecarboxylate, ethyl 4-formyl-3,5-dimethyl-1H-2-pyrrolecarboxylate, ethyl 4-formyl-2,5-dimethyl-1H-3-pyrrolecarboxylate and l-acetyl-1H-3-indolecarbaldehyde have been condensed in a molar ratio with hexahydro-2,4,6-pyrimidinetrione (barbituric acid) and its 1,3-dimethyl-, 1,3-diphenyl- and 1,3-dicyclohexyl- derivatives. The synthesis takes place in ethanol (or in ethanol/water in the cases of unsubstituted barbituric acid) within several hours at 20 0 - 60 0 C in the absence of any catalyst with yields in the range of 70-95%. An insufficient carbonyl activity of N-unsubstituted indole-3-carbaldehyde has been observed and overcome by a preliminary N-acethylation avoiding the inactive vinylene-carboxamide form. In addition to their pharmaceutical significance based on the interaction of two heterocyclic pharmacophores, the condensation products could also be useful as versatile intermediates for further synthesis of new heterocyclic systems. The synthesis of 5-[(4-acetyl-3,5-dimethyl-1H-2-pyrrolyl)(l-acetyl-1H-3-indolyl)methyl] hexahydr= o-2,4,6-pyrimidinetrione (60% in enol-form according to 1 H-NMR) by refluxing of [(1-acetyl-1H-3-indolyl) methylene]hexahydro-2,4,6-pyrimidinetrione] and 3-acethyl-2,4-dimethylpyrrole for 6 h in CH 3 CN illustrates their capability to add C-nucleophiles to the double bound bridging 3 heterocyclic units together. The new 17 products are TLC pure and their structures are proved by 1 H-NMR/IR-spectra which interpretation is displayed. (authors)

  7. Synthesis of racemic, R- and S-[1-11C]-β-hydroxybutyric acid

    International Nuclear Information System (INIS)

    Thorell, J.-O.; Stone-Elander, S.; Karolinska Hospital and Inst., Stockholm; Koenig, W.A.; Halldin, C.; Widen, L.

    1991-01-01

    Racemic, R- and S-β-hydroxybutyric acid were labelled with 11 C in the carboxylic position by a two-step stereospecific synthesis starting with carrier-added [ 11 C]cyanide and R/S, R- or S-propylene oxide. Hydrolysis of the intermediate nitrile with hydrochloric acid gave racemic [1- 11 C]-β-hydroxybutyric acid and R- or S-[1- 11 C]-β-hydroxybutyric acid with an enantiomeric excess of 87-97%. The total synthesis time (including HPLC purification) was 45-50 min from end of trapping. The isolated decay-corrected radiochemical yield was 20-30% based on [ 11 C]cyanide. The radiochemical purity of the products was > 99%]. (author)

  8. The intermediate state in Patd

    African Journals Online (AJOL)

    ) Jesus had assumed. (concerning the 'intermediate state') as existing, anything which does not exist. Three basic things about the intermediate state emerge from the parable: (a) Jesus recognizes that at the moment of death, in ipso articulo.

  9. Higher order antibunching in intermediate states

    International Nuclear Information System (INIS)

    Verma, Amit; Sharma, Navneet K.; Pathak, Anirban

    2008-01-01

    Since the introduction of binomial state as an intermediate state, different intermediate states have been proposed. Different nonclassical effects have also been reported in these intermediate states. But till now higher order antibunching is predicted in only one type of intermediate state, which is known as shadowed negative binomial state. Recently we have shown that the higher order antibunching is not a rare phenomenon [P. Gupta, P. Pandey, A. Pathak, J. Phys. B 39 (2006) 1137]. To establish our earlier claim further, here we have shown that the higher order antibunching can be seen in different intermediate states, such as binomial state, reciprocal binomial state, hypergeometric state, generalized binomial state, negative binomial state and photon added coherent state. We have studied the possibility of observing the higher order subpoissonian photon statistics in different limits of intermediate states. The effects of different control parameters on the depth of non classicality have also been studied in this connection and it has been shown that the depth of nonclassicality can be tuned by controlling various physical parameters

  10. The Synthesis of a kind of dipeptide

    International Nuclear Information System (INIS)

    He, Jiaheng

    2009-04-01

    The research on novel radioiodopharmaceutical which treat tumor efficiently is meaningful, moreover, this result just base on the synthesis of the prodrug of radiopharmaceutical. About 85% of malignacy express positive for telomer- ase. It aims to search for a kind of new compound, which can restrain telomer- ase and therapy tumor. In this work, a novel prodrug of radioiodopharmaceutical(C 6 H 4 IPOC1NH (CH 2 ) 6 NH-Leu-Gly-Boc)had been designed and synthe- sized. Some important inter-mediates also had been synthesized. The compound had been analysed using E.S., 1 HNMR(D 2 O, 200 MHz) and ESI-MS. The results indicated that the synthesis was successful. C 6 H 4 IPOC1NH(CH 2 ) 6 NH- Leu-Gly-Boc was synthesised from liquid phase instead of trational state phase, which would reduce the cost and improve the maneuverability. (authors)

  11. Synthesis and characterization of Taurine

    Directory of Open Access Journals (Sweden)

    B Bayarmaa

    2014-10-01

    Full Text Available Have been obtained 2-aminoethanesulfonic acid (taurine from ethanolamine, sulfuric acid and sodium sulfite during the synthesis in laboratory condition. The process involves two steps of reactions, the first was esterification of ethanolamine with sulfuric acid to produce the intermediate product of 2-aminoethyl ester which than was extended to the second step by sulfonation with sodium sulfite to produce 2-aminoethanesulfonic acid. Resulting product was analyzed using 1H-NMR, IR, FAB-MS analysis and examined purity characterizations of the synthesized products. DOI: http://dx.doi.org/10.5564/mjc.v14i0.200 Mongolian Journal of Chemistry 14 (40, 2013, p57-60

  12. Synthesis of a Fluorescent Acridone Using a Grignard Addition, Oxidation, and Nucleophilic Aromatic Substitution Reaction Sequence

    Science.gov (United States)

    Goodrich, Samuel; Patel, Miloni; Woydziak, Zachary R.

    2015-01-01

    A three-pot synthesis oriented for an undergraduate organic chemistry laboratory was developed to construct a fluorescent acridone molecule. This laboratory experiment utilizes Grignard addition to an aldehyde, alcohol oxidation, and iterative nucleophilic aromatic substitution steps to produce the final product. Each of the intermediates and the…

  13. One ring to rule them all: trafficking of heme and heme synthesis intermediates in the metazoans.

    Science.gov (United States)

    Hamza, Iqbal; Dailey, Harry A

    2012-09-01

    The appearance of heme, an organic ring surrounding an iron atom, in evolution forever changed the efficiency with which organisms were able to generate energy, utilize gasses and catalyze numerous reactions. Because of this, heme has become a near ubiquitous compound among living organisms. In this review we have attempted to assess the current state of heme synthesis and trafficking with a goal of identifying crucial missing information, and propose hypotheses related to trafficking that may generate discussion and research. The possibilities of spatially organized supramolecular enzyme complexes and organelle structures that facilitate efficient heme synthesis and subsequent trafficking are discussed and evaluated. Recently identified players in heme transport and trafficking are reviewed and placed in an organismal context. Additionally, older, well established data are reexamined in light of more recent studies on cellular organization and data available from newer model organisms. This article is part of a Special Issue entitled: Cell Biology of Metals. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Comparison of High, Intermediate, and Low Frequency Shock Wave Lithotripsy for Urinary Tract Stone Disease: Systematic Review and Network Meta-Analysis.

    Science.gov (United States)

    Kang, Dong Hyuk; Cho, Kang Su; Ham, Won Sik; Lee, Hyungmin; Kwon, Jong Kyou; Choi, Young Deuk; Lee, Joo Yong

    2016-01-01

    To perform a systematic review and network meta-analysis of randomized controlled trials (RCTs) to determine the optimal shock wave lithotripsy (SWL) frequency range for treating urinary stones, i.e., high-frequency (100-120 waves/minute), intermediate-frequency (80-90 waves/minute), and low-frequency (60-70 waves/minute) lithotripsy. Relevant RCTs were identified from electronic databases for meta-analysis of SWL success and complication rates. Using pairwise and network meta-analyses, comparisons were made by qualitative and quantitative syntheses. Outcome variables are provided as odds ratios (ORs) with 95% confidence intervals (CIs). Thirteen articles were included in the qualitative and quantitative synthesis using pairwise and network meta-analyses. On pairwise meta-analyses, comparable inter-study heterogeneity was observed for the success rate. On network meta-analyses, the success rates of low- (OR 2.2; 95% CI 1.5-2.6) and intermediate-frequency SWL (OR 2.5; 95% CI 1.3-4.6) were higher than high-frequency SWL. Forest plots from the network meta-analysis showed no significant differences in the success rate between low-frequency SWL versus intermediate-frequency SWL (OR 0.87; 95% CI 0.51-1.7). There were no differences in complication rate across different SWL frequency ranges. By rank-probability testing, intermediate-frequency SWL was ranked highest for success rate, followed by low-frequency and high-frequency SWL. Low-frequency SWL was also ranked highest for low complication rate, with high- and intermediate-frequency SWL ranked lower. Intermediate- and low-frequency SWL have better treatment outcomes than high-frequency SWL when considering both efficacy and complication.

  15. [Therapy of intermediate uveitis].

    Science.gov (United States)

    Doycheva, D; Deuter, C; Zierhut, M

    2014-12-01

    Intermediate uveitis is a form of intraocular inflammation in which the vitreous body is the major site of inflammation. Intermediate uveitis is primarily treated medicinally and systemic corticosteroids are the mainstay of therapy. When recurrence of uveitis or side effects occur during corticosteroid therapy an immunosuppressive treatment is required. Cyclosporine A is the only immunosuppressive agent that is approved for therapy of uveitis in Germany; however, other immunosuppressive drugs have also been shown to be effective and well-tolerated in patients with intermediate uveitis. In severe therapy-refractory cases when conventional immunosuppressive therapy has failed, biologics can be used. In patients with unilateral uveitis or when the systemic therapy is contraindicated because of side effects, an intravitreal steroid treatment can be carried out. In certain cases a vitrectomy may be used.

  16. Thermochemical biorefinery based on dimethyl ether as intermediate: Technoeconomic assessment

    International Nuclear Information System (INIS)

    Haro, P.; Ollero, P.; Villanueva Perales, A.L.; Gómez-Barea, A.

    2013-01-01

    Highlights: ► A thermochemical biorefinery based on bio-DME as intermediate is studied. ► The assessed concepts (12) lead to multi-product generation (polygeneration). ► In all concepts DME is converted by carbonylation or hydrocarbonylation. ► Rates of return are similar to or higher than plants producing a single product. -- Abstract: Thermochemical biorefinery based on dimethyl ether (DME) as an intermediate is studied. DME is converted into methyl acetate, which can either be hydrogenated to ethanol or sold as a co-product. Considering this option together with a variety of technologies for syngas upgrading, 12 different process concepts are analyzed. The considered products are ethanol, methyl acetate, H 2 , DME and electricity. The assessment of each alternative includes biomass pretreatment, gasification, syngas clean-up and conditioning, DME synthesis and conversion, product separation, and heat and power integration. A plant size of 500 MW th processing poplar chips is taken as a basis. The resulting energy efficiency to products ranges from 34.9% to 50.2%. The largest internal rate of return (28.74%) corresponds to a concept which produces methyl acetate, DME and electricity (exported to grid). A sensitivity analysis with respect to total plant investment (TPI), total operation costs (TOC) and market price of products was carried out. The overall conclusion is that, despite its greater complexity, this kind of thermochemical biorefinery is more profitable than thermochemical bioprocesses oriented to a single product.

  17. The synthesis of a tritium, carbon-14, and stable isotope-labeled cathepsin C inhibitors.

    Science.gov (United States)

    Allen, Paul; Bragg, Ryan A; Caffrey, Moya; Ericsson, Cecilia; Hickey, Michael J; Kingston, Lee P; Elmore, Charles S

    2017-02-01

    As part of a medicinal chemistry program aimed at developing a highly potent and selective cathepsin C inhibitor, tritium, carbon-14, and stable isotope-labeled materials were required. The synthesis of tritium-labeled methanesulfonate 5 was achieved via catalytic tritiolysis of a chloro precursor, albeit at a low radiochemical purity of 67%. Tritium-labeled AZD5248 was prepared via a 3-stage synthesis, utilizing amide-directed hydrogen isotope exchange. Carbon-14 and stable isotope-labeled AZD5248 were successfully prepared through modifications of the medicinal chemistry synthetic route, enabling the use of available labeled intermediates. Copyright © 2016 John Wiley & Sons, Ltd.

  18. Precursor/product studies of macrophage synthesis of nitrite, nitrate and N-nitrosamines

    International Nuclear Information System (INIS)

    Iyengar, R.; Marletta, M.A.

    1987-01-01

    Previous experiments showed that nitrite, nitrate and N-nitrosamine synthesis was carried out by both stimulated macrophages (M phi) and a number of M phi cell lines. Here the authors report the precursor to NO 2 - , NO 3 - , and the source of the nitrosating agent. Previous kinetic studies established a time lag for NO 2 - /NO 3 - synthesis during which protein synthesis required for product formation occurred. Medium change after the protein synthesis phase showed that L-arginine was the only amino acid essential for the synthesis. Other precursors were homoarginine, arginine methyl ester, arginine infinity-hydroxamate, argininamide and the peptide arginine-aspartate. Glutamine, citrulline, ornithine, hydroxylamine and D-arginine were among some of the non-precursors. Canavanine though not a precursor inhibited arginine-derived NO 2 -/NO 3 - synthesis while D-arginine had no effect. When 15 N-arginine (guanido- 15 N 2 , 95%) was used, GC/MS results showed that all the NO 2 - /NO 3 - synthesized was derived exclusively from these two guanido nitrogens. Similar labeling experiments carried out in the presence of morpholine showed that the isotopic enrichment of N-nitrosomorpholine was the same as that of NO 2 - /NO 3 - synthesized, suggesting that the nitrosating agent is a common intermediate. In conclusion, NO 2 - /NO 3 - and N-nitrosomorpholine synthesis by stimulated macrophages is derived specifically from the two guanido nitrogens of arginine

  19. Effect of Intermediate Hosts on Emerging Zoonoses.

    Science.gov (United States)

    Cui, Jing-An; Chen, Fangyuan; Fan, Shengjie

    2017-08-01

    Most emerging zoonotic pathogens originate from animals. They can directly infect humans through natural reservoirs or indirectly through intermediate hosts. As a bridge, an intermediate host plays different roles in the transmission of zoonotic pathogens. In this study, we present three types of pathogen transmission to evaluate the effect of intermediate hosts on emerging zoonotic diseases in human epidemics. These types are identified as follows: TYPE 1, pathogen transmission without an intermediate host for comparison; TYPE 2, pathogen transmission with an intermediate host as an amplifier; and TYPE 3, pathogen transmission with an intermediate host as a vessel for genetic variation. In addition, we established three mathematical models to elucidate the mechanisms underlying zoonotic disease transmission according to these three types. Stability analysis indicated that the existence of intermediate hosts increased the difficulty of controlling zoonotic diseases because of more difficult conditions to satisfy for the disease to die out. The human epidemic would die out under the following conditions: TYPE 1: [Formula: see text] and [Formula: see text]; TYPE 2: [Formula: see text], [Formula: see text], and [Formula: see text]; and TYPE 3: [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] Simulation with similar parameters demonstrated that intermediate hosts could change the peak time and number of infected humans during a human epidemic; intermediate hosts also exerted different effects on controlling the prevalence of a human epidemic with natural reservoirs in different periods, which is important in addressing problems in public health. Monitoring and controlling the number of natural reservoirs and intermediate hosts at the right time would successfully manage and prevent the prevalence of emerging zoonoses in humans.

  20. Amino Acid Based Synthesis of Chiral Long Chain Diamines and Tetramines

    Directory of Open Access Journals (Sweden)

    George Kokotos

    2002-10-01

    Full Text Available A method for the synthesis of long chain diamines and tetramines starting from natural α-amino acids is reported. Diamines and tetramines were prepared through the Wittig olefination reaction of N-protected amino aldehydes obtained from phenylalanine and lysine. A 1,2,17,18-tetramine was synthesized using (2S-1-azido-2-[bis(tert-butoxycarbonyl-amino]-5-oxopentane as key-intermediate compound.

  1. Intermediate structure and threshold phenomena

    International Nuclear Information System (INIS)

    Hategan, Cornel

    2004-01-01

    The Intermediate Structure, evidenced through microstructures of the neutron strength function, is reflected in open reaction channels as fluctuations in excitation function of nuclear threshold effects. The intermediate state supporting both neutron strength function and nuclear threshold effect is a micro-giant neutron threshold state. (author)

  2. Asymmetric synthesis including enzymatic catalysis of 11C and 13N labelled amino acids

    International Nuclear Information System (INIS)

    Langstrom, B.; Antonio, G.; Bjurling, P.; Fasth, K.J.; Westerberg, G.; Watanabe, Y.

    1993-01-01

    Use of asymmetric synthesis in production of 11 C- and 13 N-labelled amino acids has been shown to be a useful approach in order to prepare amino acids routinely for PET-studies. Such PET-studies are focused either on problems related to amino acid transport, protein synthesis rate or the turnover of neurotransmitters from amino acids. The paper discusses matters regarding synthetic strategies and techniques involving production of precursors, labelled intermediates and main reaction sequences. In synthesis using the short-lived β + -emitters like 11 C and 13 N with T 1/2 of 20.3 and 10.0 min respectively, many special aspects have to be considered. The use of enzymes as catalysts has shown to be a useful tool in such preparations. The design of the labelled amino acids especially considering the stereochemistry, the position of the label will be addressed since these points are important both with regard to the application of the labelled amino acids as well as to the synthesis itself. In this presentation of the synthesis of labelled amino acids these various aspects are discussed

  3. Intermediate algebra & analytic geometry

    CERN Document Server

    Gondin, William R

    1967-01-01

    Intermediate Algebra & Analytic Geometry Made Simple focuses on the principles, processes, calculations, and methodologies involved in intermediate algebra and analytic geometry. The publication first offers information on linear equations in two unknowns and variables, functions, and graphs. Discussions focus on graphic interpretations, explicit and implicit functions, first quadrant graphs, variables and functions, determinate and indeterminate systems, independent and dependent equations, and defective and redundant systems. The text then examines quadratic equations in one variable, system

  4. The asymmetric total synthesis of (+)- and (-)-trypargine via Noyori asymmetric transfer hydrogenation

    International Nuclear Information System (INIS)

    Pilli, Ronaldo A.; Rodrigues Junior, Manoel Trindade

    2009-01-01

    A concise and efficient total synthesis of (+)- and (-)-trypargine (6 steps and 38% overall yield), a 1-substituted β-carboline guanidine alkaloid isolated from the skin of the African frog K. senegalensis, was developed based on the construction of the b-carboline moiety via Bischler-Napieralski reaction and the enantioselective reduction of the dihydro-β-carboline intermediate via an asymmetric transfer hydrogenation reaction using Noyori's protocol. (author)

  5. Asymmetric Synthesis of the Epimeric (3S-3-((E-Hex-1-enyl-2-methylcyclohexanones

    Directory of Open Access Journals (Sweden)

    Pierre J. De Clercq

    2007-02-01

    Full Text Available The asymmetric rhodium-catalysed 1,4-addition of alkenylzirconium reagents to 2-cyclohexenone can be useful in the synthesis of 3-alkenyl-2-methylcyclohexanones, provided that formaldehyde is used in trapping the intermediate zirconium enolates. In this manner a four-step sequence leading to the two epimeric 3-hexenyl-2-methylcyclohexanones in enantiomeric form was developed.

  6. Program TOTELA calculating basic cross sections in intermediate energy region by using systematics

    International Nuclear Information System (INIS)

    Fukahori, Tokio; Niita, Koji

    2000-01-01

    Program TOTELA can calculate neutron- and proton-induced total, elastic scattering and reaction cross sections and angular distribution of elastic scattering in the intermediate energy region from 20 MeV to 3 GeV. The TOTELA adopts the systematics modified from that by Pearlstein to reproduce the experimental data and LA150 evaluation better. The calculated results compared with experimental data and LA150 evaluation are shown in figures. The TOTELA results can reproduce those data almost well. The TOTELA was developed to fill the lack of experimental data of above quantities in the intermediate energy region and to use for production of JENDL High Energy File. In the case that there is no experimental data of above quantities, the optical model parameters can be fitted by using TOTELA results. From this point of view, it is also useful to compare the optical model calculation by using RIPL with TOTELA results, in order to verify the parameter quality. Input data of TOTELA is only atomic and mass numbers of incident particle and target nuclide and input/output file names. The output of TOTELA calculation is in ENDF-6 format used in the intermediate energy nuclear data files. It is easy to modify the main routine by users. Details are written in each subroutine and main routine

  7. From ‘machine-world’ to ‘God-world’ - world pictures and world views 1

    Directory of Open Access Journals (Sweden)

    J. J. Venter

    1992-03-01

    Full Text Available This article mainly consists of an analysis of the successive historical expansions of the mechanistic and the organistic world pictures into world views. In conclusion the presently popular form of the organistic world view, New Age occultism, is compared with the 'traditional' African world view. In this way the author attempts to realise three different aims: firstly to show how world pictures, developed within specific disciplines, are transformed into world views by expansionary application in other disciplines and /or cultural areas; secondly that occultism is regaining intellectual respectability by presenting itself as part of the ‘new’ organistic, scientific view of the world; and thirdly that there are strong similarities between the new Western occultism and the traditional African world view (which opens up possibilities of synthesis between these two.

  8. Mechanism and microstructural evolution of polyol mediated synthesis of nanostructured M-type SrFe{sub 12}O{sub 19}

    Energy Technology Data Exchange (ETDEWEB)

    Tenorio Gonzalez, F.N.; Bolarín Miró, A.M. [Área Académica de Ciencias de la Tierra y Materiales, UAEH, Carr. Pachuca-Tulancingo Km. 4.5, C.P. 42184 Pachuca, Hidalgo (Mexico); Sánchez De Jesús, F., E-mail: fsanchez@uaeh.edu.mx [Área Académica de Ciencias de la Tierra y Materiales, UAEH, Carr. Pachuca-Tulancingo Km. 4.5, C.P. 42184 Pachuca, Hidalgo (Mexico); Cortés Escobedo, C.A. [Centro de Investigación e Innovación Tecnológica del IPN, Cda. CECATI S/N, Col. Sta. Catarina, C. P. 02250 Azcapotzalco, D. F. (Mexico); Ammar, S. [Université Paris Diderot, Paris 7, Laboratoire Interfaces, Traitements, Organisation et Dynamiqué des Systéme UMR, 7086, Paris (France)

    2016-06-01

    The synthesis mechanism of nanostructured M-type strontium hexaferrite SrFe{sub 12}O{sub 19} with high coercivity (5.7 kOe) obtained by a polyol process and annealing is proposed. The results show that the hexaferrite is synthesized through the formation of a complex with diethylene glycol during the hydrolysis and solvation stage, followed by the condensation of magnetite and strontium oxide. The results of the monitoring of the process by X-ray diffraction (XRD) of synthesized powders, magnetization hysteresis loops and micromorphology are presented and discussed. The proposed mechanism suggests the intermediate formation of the magnetite phase, which shows coercivity near zero at room temperature and confirms the nanoscale of the particles. Results of thermogravimetric and differential thermal analysis indicate that this phase is followed by the formation of the hematite phase after a heat treatment up to 543 °C in an oxidizing atmosphere. Finally, the hexagonal phase is obtained after application of annealing at 836 °C through the reaction between hematite and strontium oxide. - Highlights: • SrFe{sub 12}O{sub 19} was successfully obtained by a polyol-assisted synthesis. • Magnetite nanoparticles have been obtained as intermediate phase. • A synthesis mechanism for the growing stage of magnetite is proposed. • A reaction sequence and the synthesis mechanism to obtain hexaferrite is presented.

  9. Regularities of intermediate adsorption complex relaxation

    International Nuclear Information System (INIS)

    Manukova, L.A.

    1982-01-01

    The experimental data, characterizing the regularities of intermediate adsorption complex relaxation in the polycrystalline Mo-N 2 system at 77 K are given. The method of molecular beam has been used in the investigation. The analytical expressions of change regularity in the relaxation process of full and specific rates - of transition from intermediate state into ''non-reversible'', of desorption into the gas phase and accumUlation of the particles in the intermediate state are obtained

  10. FINANCIAL INTERMEDIATION, ENTREPRENEURSHIP AND ECONOMIC GROWTH

    OpenAIRE

    Wenli Cheng

    2007-01-01

    This paper presents a simple general equilibrium model of financial intermediation, entrepreneurship and economic growth. In this model, the role of financial intermediation is to pool savings and to lend the pooled funds to an entrepreneur, who in turn invests the funds in a new production technology. The adoption of the new production technology improves individual real income. Thus financial intermediation promotes economic growth through affecting individuals’ saving behaviour and enabl...

  11. Some Intermediate-Level Violin Concertos.

    Science.gov (United States)

    Abramson, Michael

    1997-01-01

    Contends that many violin students attempt difficult concertos before they are technically or musically prepared. Identifies a variety of concertos at the intermediate and advanced intermediate-level for students to study and master before attempting the advanced works by Bach and Mozart. Includes concertos by Vivaldi, Leclair, Viotti, Haydn,…

  12. A view to the intermediate-depth Vrancea earthquake of May 30, 1990: Case study in NE Bulgaria

    International Nuclear Information System (INIS)

    Kouteva, M.; Paskaleva, I.; Panza, G.F.; Romanelli, F.

    2004-02-01

    A deterministic analytical procedure for ground motion modelling, combining both modal summation and mode coupling techniques has been implemented to obtain synthetic seismic signals at Russe, NE Bulgaria, due to one of the strongest Vrancea intermediate-depth earthquakes, which occurred during the last century, May 30, 1990. The frequency content of the synthetic signals in different frequency ranges, up to 1 and 2Hz, has been studied separately. The results of this study, i.e. time histories and related ground motions parameters, can be used for different earthquake engineering analyses, e.g. structural performance assessments. (author)

  13. Characteristics of intermediate-energy nucleons emitted from 50 GeV

    International Nuclear Information System (INIS)

    Goyal, D.P.; Singh, S.; Arya, N.S.

    1984-01-01

    The multiplicity and angular distributions of intermediate-energy (grey) nucleons are studied from 50 GeV π - -nucleus data and compared with those available from π - -nucleus and p-nucleus interactions at other energies. The value of is found to be dependent both on the energy as well as on the projectile. The former variation is attributable to kinematics and the latter explainable on the basis of the additive quark model. The angular distribution of grey particles is found to be independent of energy, projectile and target, which supports the view that grey particles are chiefly due to knock-on recoiling protons. The various versions of the cascade model, however, are unable to explain any of the observed features of grey-particle distributions

  14. Crystallographic snapshot of cellulose synthesis and membrane translocation.

    Science.gov (United States)

    Morgan, Jacob L W; Strumillo, Joanna; Zimmer, Jochen

    2013-01-10

    Cellulose, the most abundant biological macromolecule, is an extracellular, linear polymer of glucose molecules. It represents an essential component of plant cell walls but is also found in algae and bacteria. In bacteria, cellulose production frequently correlates with the formation of biofilms, a sessile, multicellular growth form. Cellulose synthesis and transport across the inner bacterial membrane is mediated by a complex of the membrane-integrated catalytic BcsA subunit and the membrane-anchored, periplasmic BcsB protein. Here we present the crystal structure of a complex of BcsA and BcsB from Rhodobacter sphaeroides containing a translocating polysaccharide. The structure of the BcsA-BcsB translocation intermediate reveals the architecture of the cellulose synthase, demonstrates how BcsA forms a cellulose-conducting channel, and suggests a model for the coupling of cellulose synthesis and translocation in which the nascent polysaccharide is extended by one glucose molecule at a time.

  15. Welding. Performance Objectives. Intermediate Course.

    Science.gov (United States)

    Vincent, Kenneth

    Several intermediate performance objectives and corresponding criterion measures are listed for each of nine terminal objectives for an intermediate welding course. The materials were developed for a 36-week (3 hours daily) course designed to prepare the student for employment in the field of welding. Electric welding and specialized (TIG & MIG)…

  16. Model Research On Synthesis Of Al2O3-C Layers By MOCVD

    Directory of Open Access Journals (Sweden)

    Sawka A.

    2015-06-01

    Full Text Available These are model studies whose aim is to obtain information that would allow development of new technology for synthesizing monolayers of Al2O3-C with adjusted microstructure on cemented carbides. The Al2O3-C layer will constitute an intermediate layer on which the outer layer of Al2O3 without carbon is synthesized. The purpose of the intermediate layer is to block the cobalt diffusion to the synthesized outer layer of Al2O3 and to stop the diffusion of air oxygen to the substrate during the synthesis of the outer layer. This layer should be thin, continuous, dense and uniform in thickness.

  17. Oxetanes: Recent Advances in Synthesis, Reactivity, and Medicinal Chemistry.

    Science.gov (United States)

    Bull, James A; Croft, Rosemary A; Davis, Owen A; Doran, Robert; Morgan, Kate F

    2016-10-12

    The four-membered oxetane ring has been increasingly exploited for its contrasting behaviors: its influence on physicochemical properties as a stable motif in medicinal chemistry and its propensity to undergo ring-opening reactions as a synthetic intermediate. These applications have driven numerous studies into the synthesis of new oxetane derivatives. This review takes an overview of the literature for the synthesis of oxetane derivatives, concentrating on advances in the last five years up to the end of 2015. These methods are clustered by strategies for preparation of the ring and further derivatization of preformed oxetane-containing building blocks. Examples of the use of oxetanes in medicinal chemistry are reported, including a collation of oxetane derivatives appearing in recent patents for medicinal chemistry applications. Finally, examples of oxetane derivatives in ring-opening and ring-expansion reactions are described.

  18. A new simple and high-yield synthesis of 5α-dihydrotestosterone (DHT), a potent androgen receptor agonist.

    Science.gov (United States)

    Purushottamachar, Puranik; Njar, Vincent C O

    2012-12-01

    We have devised an efficient procedure for the synthesis of 5α-dihydrotestosterone (DHT) (1) starting from 3β-hydroxy-5α-androstan-17-one, providing the product in unprecedented 82% yield. A reported method of using toxic Jones reagent is replaced by milder oxidizing agent (NMO/TPAP) in the synthesis of a key intermediate 17β-[(tert-butyldimethylsilyl)oxy]-5α-androstan-3-one (18). This new procedure is simple, does not require special apparatus/precautions or chromatographic purification in most of the steps. Copyright © 2012 Elsevier Inc. All rights reserved.

  19. The first preparative solution phase synthesis of melanotan II

    Directory of Open Access Journals (Sweden)

    2008-10-01

    Full Text Available Melanotan II is a synthetic cyclic heptapeptide used to prevent a sunlight-induced skin cancer by stimulating the skin tanning process. In this paper we report the first solution phase synthesis of the title compound. The hexapeptide sequence has been assembled by [(2+2+1+1] scheme. After removing the orthogonal protection, a carbodiimide mediated lactamization, involving the ε-amino group of lysine and γ-carboxy group of aspartic acid, led to a cyclic intermediate. Appending N-acetylnorleucine concluded the assembly of melanotan II molecule. Protection of the lateral groups in arginine and tryptophan was omitted for atom and step economy reasons. The total synthesis of melanotan II was accomplished in 12 steps with 2.6% overall yield, affording >90% pure peptide without using preparative chromatography.

  20. From synthesis to function via iterative assembly of N-methyliminodiacetic acid boronate building blocks.

    Science.gov (United States)

    Li, Junqi; Grillo, Anthony S; Burke, Martin D

    2015-08-18

    The study and optimization of small molecule function is often impeded by the time-intensive and specialist-dependent process that is typically used to make such compounds. In contrast, general and automated platforms have been developed for making peptides, oligonucleotides, and increasingly oligosaccharides, where synthesis is simplified to iterative applications of the same reactions. Inspired by the way natural products are biosynthesized via the iterative assembly of a defined set of building blocks, we developed a platform for small molecule synthesis involving the iterative coupling of haloboronic acids protected as the corresponding N-methyliminodiacetic acid (MIDA) boronates. Here we summarize our efforts thus far to develop this platform into a generalized and automated approach for small molecule synthesis. We and others have employed this approach to access many polyene-based compounds, including the polyene motifs found in >75% of all polyene natural products. This platform further allowed us to derivatize amphotericin B, the powerful and resistance-evasive but also highly toxic last line of defense in treating systemic fungal infections, and thereby understand its mechanism of action. This synthesis-enabled mechanistic understanding has led us to develop less toxic derivatives currently under evaluation as improved antifungal agents. To access more Csp(3)-containing small molecules, we gained a stereocontrolled entry into chiral, non-racemic α-boryl aldehydes through the discovery of a chiral derivative of MIDA. These α-boryl aldehydes are versatile intermediates for the synthesis of many Csp(3) boronate building blocks that are otherwise difficult to access. In addition, we demonstrated the utility of these types of building blocks in accessing pharmaceutically relevant targets via an iterative Csp(3) cross-coupling cycle. We have further expanded the scope of the platform to include stereochemically complex macrocyclic and polycyclic molecules

  1. Money distribution with intermediation

    OpenAIRE

    Teles, Caio Augusto Colnago

    2013-01-01

    This pap er analyzes the distribution of money holdings in a commo dity money search-based mo del with intermediation. Intro ducing heterogeneity of costs to the Kiyotaki e Wright ( 1989 ) mo del, Cavalcanti e Puzzello ( 2010) gives rise to a non-degenerated distribution of money. We extend further this mo del intro ducing intermediation in the trading pro cess. We show that the distribution of money matters for savings decisions. This gives rises to a xed p oint problem for the ...

  2. Statistical view on nuclear multifragmentation: Primary decays

    International Nuclear Information System (INIS)

    Raduta, A.H.; Raduta, A.R.

    1997-01-01

    An overall view on the universe of primary decays appearing in the process of nuclear multifragmentation via a microcanonical Monte Carlo Metropolis type simulation is given. General characteristics like mass and charge distributions, relative probabilities of evaporation, fission, fragmentation and vaporization, average number of fragments and distributions of a number of intermediate mass fragments offer valuable information about the intimacy of the process. The capability of the model to describe unitary very different breakup regimes is pointed out. Predictions for charge distributions, isotopic yields, and fission mass distributions are compared with experimental data. copyright 1997 The American Physical Society

  3. “Best fit” framework synthesis: refining the method

    Science.gov (United States)

    2013-01-01

    Background Following publication of the first worked example of the “best fit” method of evidence synthesis for the systematic review of qualitative evidence in this journal, the originators of the method identified a need to specify more fully some aspects of this particular derivative of framework synthesis. Methods and Results We therefore present a second such worked example in which all techniques are defined and explained, and their appropriateness is assessed. Specified features of the method include the development of new techniques to identify theories in a systematic manner; the creation of an a priori framework for the synthesis; and the “testing” of the synthesis. An innovative combination of existing methods of quality assessment, analysis and synthesis is used to complete the process. This second worked example was a qualitative evidence synthesis of employees’ views of workplace smoking cessation interventions, in which the “best fit” method was found to be practical and fit for purpose. Conclusions The method is suited to producing context-specific conceptual models for describing or explaining the decision-making and health behaviours of patients and other groups. It offers a pragmatic means of conducting rapid qualitative evidence synthesis and generating programme theories relating to intervention effectiveness, which might be of relevance both to researchers and policy-makers. PMID:23497061

  4. Search for intermediate vector bosons

    International Nuclear Information System (INIS)

    Klajn, D.B.; Rubbia, K.; Meer, S.

    1983-01-01

    Problem of registration and search for intermediate vector bosons is discussed. According to weak-current theory there are three intermediate vector bosons with +1(W + )-1(W - ) and zero (Z 0 ) electric charges. It was suggested to conduct the investigation into particles in 1976 by cline, Rubbia and Makintair using proton-antiproton beams. Major difficulties of the experiment are related to the necessity of formation of sufficient amount of antiparticles and the method of antiproton beam ''cooling'' for the purpose of reduction of its random movements. The stochastic method was suggested by van der Meer in 1968 as one of possible cooling methods. Several large detectors were designed for searching intermediate vector bosons

  5. First- and second-generation total synthesis of ciguatoxin CTX3C.

    Science.gov (United States)

    Inoue, Masayuki; Miyazaki, Keisuke; Uehara, Hisatoshi; Maruyama, Megumi; Hirama, Masahiro

    2004-08-17

    More than 20,000 people suffer annually from ciguatera seafood poisoning in subtropical and tropical regions. The extremely low content of the causative neurotoxins, designated as ciguatoxins, in fish has hampered isolation, detailed biological studies, and preparation of anti-ciguatoxin antibodies for detecting these toxins. Furthermore, the large (3 nm in length) and complex molecular structure of ciguatoxins has impeded chemists from completing their total synthesis. In this article, the full details of studies leading to the total synthesis of ciguatoxin CTX3C are provided. The key elements of the first-generation approach include O,O-acetal formation from the right and left wing fragments, conversion from O,O-acetal to O,S-acetal, a radical reaction to cyclize the G ring, a ring-closing metathesis reaction to close the F ring, and final removal of the 2-naphtylmethyl protective groups. Subsequent studies provided a second-generation total synthesis, which is more concise and results in a higher yield. Second-generation synthesis was accomplished by using a direct method of constructing the key intermediate O,S-acetal from alpha-chlorosulfide and a secondary alcohol. These syntheses ensure a practical supply of ciguatoxin for biological applications.

  6. Validation of intermediate end points in cancer research.

    Science.gov (United States)

    Schatzkin, A; Freedman, L S; Schiffman, M H; Dawsey, S M

    1990-11-21

    Investigations using intermediate end points as cancer surrogates are quicker, smaller, and less expensive than studies that use malignancy as the end point. We present a strategy for determining whether a given biomarker is a valid intermediate end point between an exposure and incidence of cancer. Candidate intermediate end points may be selected from case series, ecologic studies, and animal experiments. Prospective cohort and sometimes case-control studies may be used to quantify the intermediate end point-cancer association. The most appropriate measure of this association is the attributable proportion. The intermediate end point is a valid cancer surrogate if the attributable proportion is close to 1.0, but not if it is close to 0. Usually, the attributable proportion is close to neither 1.0 nor 0; in this case, valid surrogacy requires that the intermediate end point mediate an established exposure-cancer relation. This would in turn imply that the exposure effect would vanish if adjusted for the intermediate end point. We discuss the relative advantages of intervention and observational studies for the validation of intermediate end points. This validation strategy also may be applied to intermediate end points for adverse reproductive outcomes and chronic diseases other than cancer.

  7. Influence of the synthesis route and parameters on the thermoluminescence response of ZnO phosphors

    International Nuclear Information System (INIS)

    Orante B, V.; Bernal, R.; Brown, F.; Castano, V.M.; Cruz V, C.

    2007-01-01

    Full text: ZnO nano phosphors obtained by thermal annealing of chemically synthesized ZnS powder has been recently reported to exhibit striking properties to be used as thermoluminescence (TL) dosimeters for intermediate and high doses of ionizing radiation. Encouraged by these results, we began a research focused to improve the process of fabrication of ZnO phosphors, by varying the chemical route and parameters of synthesis in each route. We essayed three different chemical ways to obtain ZnO. In each case, different sintering processes were applied to the product obtained from the chemical reaction. TL is very sensitive to impurities traces, whose incorporation is influenced by the synthesis history, so that we obtain that general features of TL glow curves can be tuned by controlling the synthesis parameters. (Author)

  8. Synthesis of phenanthrenes through copper-catalyzed cross-coupling of N-tosylhydrazones with terminal alkynes.

    Science.gov (United States)

    Hossain, Mohammad Lokman; Ye, Fei; Liu, Zhenxing; Xia, Ying; Shi, Yi; Zhou, Lei; Zhang, Yan; Wang, Jianbo

    2014-09-19

    A novel protocol for the synthesis of phenanthrenes through the copper-catalyzed reaction of aromatic tosylhydrazones with terminal alkynes is explored. The reaction proceeds via the formation of an allene intermediate and subsequent six-π-electron cyclization-isomerization, affording phenanthrene derivatives in good yields. The transformation can be performed in two ways: (1) with N-tosylhydrazones derived from [1,1'-biphenyl]-2-carbaldehydes and terminal alkynes as the starting materials and (2) with N-tosylhydrazones derived from aromatic aldehydes and 2-alkynyl biphenyls as the starting materials. This new phenanthrene synthesis uses readily available starting materials and a cheap copper catalyst and has a wide range of functional group compatibility.

  9. Simplifying biochemical models with intermediate species

    DEFF Research Database (Denmark)

    Feliu, Elisenda; Wiuf, Carsten

    2013-01-01

    techniques, we study systematically the effects of intermediate, or transient, species in biochemical systems and provide a simple, yet rigorous mathematical classification of all models obtained from a core model by including intermediates. Main examples include enzymatic and post-translational modification...... systems, where intermediates often are considered insignificant and neglected in a model, or they are not included because we are unaware of their existence. All possible models obtained from the core model are classified into a finite number of classes. Each class is defined by a mathematically simple...... canonical model that characterizes crucial dynamical properties, such as mono- and multistationarity and stability of steady states, of all models in the class. We show that if the core model does not have conservation laws, then the introduction of intermediates does not change the steady...

  10. Synthesis of propargylic and allenic carbamates via the C-H amination of alkynes.

    Science.gov (United States)

    Grigg, R David; Rigoli, Jared W; Pearce, Simon D; Schomaker, Jennifer M

    2012-01-06

    Propargylic amines are important intermediates for the synthesis of nitrogen-containing heterocycles. The insertion of a nitrene into a propargylic C-H bond has not been explored, despite the attention directed toward the Rh-catalyzed amination of other types of C-H bonds. In this communication, the conversion of a series of homopropargylic carbamates to propargylic carbamates and aminated allenes is described. © 2011 American Chemical Society

  11. One-Pot Conversion of Carbohydrates into Furan Derivatives via Furfural and 5-Hydroxylmethylfurfural as Intermediates.

    Science.gov (United States)

    Liu, Bing; Zhang, Zehui

    2016-08-23

    Recently, there has been growing interest in the transformation of renewable biomass into value-added fuels and chemicals. The catalytic conversion of naturally abundant carbohydrates can generate two-important furan chemicals: 5-hydroxymethylfurfural (HMF) from C6 carbohydrates and furfural from C5 carbohydrates. Both HMF and furfural have received great interest as precursors in the synthesis of commodity chemicals and liquid fuels. In recent years, a trend has emerged to integrate sequential catalytic processes involving multistep reactions for the direct one-pot transformation of carbohydrates into the aimed fuels and chemicals. One-pot reactions have remarkably unique and environmentally friendly benefits, including the fact that isolation and purification of intermediate compounds can be avoided. Herein, the present article aims to review recent advances in the one-pot conversion of carbohydrates into furan derivatives via furfural and HMF as intermediates. Special attention will be paid to the catalytic systems, mechanistic insight, reaction pathways, and catalyst stability. It is expected that this review will guide researchers to develop effective catalytic systems for the one-pot transformation of carbohydrates into furan derivatives. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Reactions of stabilized Criegee Intermediates

    Science.gov (United States)

    Vereecken, Luc; Harder, Hartwig; Novelli, Anna

    2014-05-01

    Carbonyl oxides (Criegee intermediates) were proposed as key intermediates in the gas phase ozonolysis of alkenes in 1975 by Rudolf Criegee. Despite the importance of ozonolysis in atmospheric chemistry, direct observation of these intermediates remained elusive, with only indirect experimental evidence for their role in the oxidation of hydrocarbons, e.g. through scavenging experiments. Direct experimental observation of stabilized CI has only been achieved since 2008. Since then, a concerted effort using experimental and theoretical means is in motion to characterize the chemistry and kinetics of these reactive intermediates. We present the results of theoretical investigations of the chemistry of Criegee intermediates with a series of coreactants which may be of importance in the atmosphere, in experimental setups, or both. This includes the CI+CI cross-reaction, which proceeds with a rate coefficient near the collision limit and can be important in experimental conditions. The CI + alkene reactions show strong dependence of the rate coefficient depending on the coreactants, but is generally found to be rather slow. The CI + ozone reaction is sufficiently fast to occur both in experiment and the free troposphere, and acts as a sink for CI. The reaction of CI with hydroperoxides, ROOH, is complex, and leads both to the formation of oligomers, as to the formation of reactive etheroxides, with a moderately fast rate coefficient. The importance of these reactions is placed in the context of the reaction conditions in different atmospheric environments ranging from unpolluted to highly polluted.

  13. Sol – Gel synthesis and characterization of magnesium peroxide nanoparticles

    International Nuclear Information System (INIS)

    Jaison, J; Chan, Y S; Ashok raja, C; Balakumar, S

    2015-01-01

    Magnesium peroxide is an excellent source of oxygen in agriculture applications, for instance it is used in waste management as a material for soil bioremediation to remove contaminants from polluted underground water, biological wastes treatment to break down hydrocarbon, etc. In the present study, sol-gel synthesis of magnesium peroxide (MgO 2 ) nanoparticles is reported. Magnesium peroxide is odourless; fine peroxide which releases oxygen when reacts with water. During the sol-gel synthesis, the magnesium malonate intermediate is formed which was then calcinated to obtain MgO 2 nanoparticles. The synthesized nanoparticles were characterized using Thermo gravimetric -Differential Thermal Analysis (TG- DTA), X-Ray Diffraction studies (XRD) and High Resolution Transmission Electron Microscope (HRTEM). Our study provides a clear insight that the formation of magnesium malonate during the synthesis was due to the reaction between magnesium acetate, oxalic acid and ethanol. In our study, we can conclude that the calcination temperature has a strong influence on particle size, morphology, monodispersity and the chemistry of the particles. (paper)

  14. The intermediate endpoint effect in logistic and probit regression

    Science.gov (United States)

    MacKinnon, DP; Lockwood, CM; Brown, CH; Wang, W; Hoffman, JM

    2010-01-01

    Background An intermediate endpoint is hypothesized to be in the middle of the causal sequence relating an independent variable to a dependent variable. The intermediate variable is also called a surrogate or mediating variable and the corresponding effect is called the mediated, surrogate endpoint, or intermediate endpoint effect. Clinical studies are often designed to change an intermediate or surrogate endpoint and through this intermediate change influence the ultimate endpoint. In many intermediate endpoint clinical studies the dependent variable is binary, and logistic or probit regression is used. Purpose The purpose of this study is to describe a limitation of a widely used approach to assessing intermediate endpoint effects and to propose an alternative method, based on products of coefficients, that yields more accurate results. Methods The intermediate endpoint model for a binary outcome is described for a true binary outcome and for a dichotomization of a latent continuous outcome. Plots of true values and a simulation study are used to evaluate the different methods. Results Distorted estimates of the intermediate endpoint effect and incorrect conclusions can result from the application of widely used methods to assess the intermediate endpoint effect. The same problem occurs for the proportion of an effect explained by an intermediate endpoint, which has been suggested as a useful measure for identifying intermediate endpoints. A solution to this problem is given based on the relationship between latent variable modeling and logistic or probit regression. Limitations More complicated intermediate variable models are not addressed in the study, although the methods described in the article can be extended to these more complicated models. Conclusions Researchers are encouraged to use an intermediate endpoint method based on the product of regression coefficients. A common method based on difference in coefficient methods can lead to distorted

  15. Application of Chan-Lam cross coupling for the synthesis of N-heterocyclic carbene precursors bearing strong electron donating or withdrawing groups

    Science.gov (United States)

    Huang, Liliang; He, Chengxiang; Sun, Zhihua

    2015-07-01

    Chan-Lam cross coupling allowed efficient synthesis of N,N’-disubstituted ortho-phenylene diamines bearing strong electron donating or withdrawing groups, such as nitro or methoxy groups, with moderate to high yields. These diamines can then be turned into N-heterocyclic carbene precursors after condensation with trimethyl orthoformate. The same strategy can also be utilized for the synthesis of N-monosubstituted aniline derivatives containing a functionalized ortho-aminomethyl group as intermediates for chiral 6-membered ring carbene precursors.

  16. Marine Microorganisms as Source of Stereoselective Esterases and Ketoreductases: Kinetic Resolution of a Prostaglandin Intermediate

    KAUST Repository

    De Vitis, Valerio; Guidi, Benedetta; Contente, Martina Letizia; Granato, Tiziana Mariarita; Conti, Paola; Molinari, Francesco; Crotti, Elena; Mapelli, Francesca; Borin, Sara S.; Daffonchio, Daniele; Romano, Diego

    2014-01-01

    A screening among bacterial strains isolated from water-brine interface of the deep hypersaline anoxic basins (DHABs) of the Eastern Mediterranean was carried out for the biocatalytical resolution of racemic propyl ester of anti-2-oxotricyclo[2.2.1.0]heptan-7-carboxylic acid (R,S)-1, a key intermediate for the synthesis of d-cloprostenol. Bacillus horneckiae 15A gave highly stereoselective reduction of (R,S)-1, whereas Halomonas aquamarina 9B enantioselectively hydrolysed (R,S)-1; in both cases, enantiomerically pure unreacted (R)-1 could be easily recovered and purified at molar conversion below 57–58 %, showing the potential of DHAB extremophile microbiome and marine-derived enzymes in stereoselective biocatalysis.

  17. Marine Microorganisms as Source of Stereoselective Esterases and Ketoreductases: Kinetic Resolution of a Prostaglandin Intermediate

    KAUST Repository

    De Vitis, Valerio

    2014-09-30

    A screening among bacterial strains isolated from water-brine interface of the deep hypersaline anoxic basins (DHABs) of the Eastern Mediterranean was carried out for the biocatalytical resolution of racemic propyl ester of anti-2-oxotricyclo[2.2.1.0]heptan-7-carboxylic acid (R,S)-1, a key intermediate for the synthesis of d-cloprostenol. Bacillus horneckiae 15A gave highly stereoselective reduction of (R,S)-1, whereas Halomonas aquamarina 9B enantioselectively hydrolysed (R,S)-1; in both cases, enantiomerically pure unreacted (R)-1 could be easily recovered and purified at molar conversion below 57–58 %, showing the potential of DHAB extremophile microbiome and marine-derived enzymes in stereoselective biocatalysis.

  18. Facile Synthesis of Quasi-One-Dimensional Au/PtAu Heterojunction Nanotubes and Their Application as Catalysts in an Oxygen-Reduction Reaction.

    Science.gov (United States)

    Cai, Kai; Liu, Jiawei; Zhang, Huan; Huang, Zhao; Lu, Zhicheng; Foda, Mohamed F; Li, Tingting; Han, Heyou

    2015-05-11

    An intermediate-template-directed method has been developed for the synthesis of quasi-one-dimensional Au/PtAu heterojunction nanotubes by the heterogeneous nucleation and growth of Au on Te/Pt core-shell nanostructures in aqueous solution. The synthesized porous Au/PtAu bimetallic nanotubes (PABNTs) consist of porous tubular framework and attached Au nanoparticles (AuNPs). The reaction intermediates played an important role in the preparation, which fabricated the framework and provided a localized reducing agent for the reduction of the Au and Pt precursors. The Pt7 Au PABNTs showed higher electrocatalytic activity and durability in the oxygen-reduction reaction (ORR) in 0.1 M HClO4 than porous Pt nanotubes (PtNTs) and commercially available Pt/C. The mass activity of PABNTs was 218 % that of commercial Pt/C after an accelerated durability test. This study demonstrates the potential of PABNTs as highly efficient electrocatalysts. In addition, this method provides a facile strategy for the synthesis of desirable hetero-nanostructures with controlled size and shape by utilizing an intermediate template. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Knowledge-based View in the Franchising Research Literature

    OpenAIRE

    TSAI, Fu-Sheng; KUO, Chin-Chiung; LIU, Chi-Fang

    2017-01-01

    Abstract. This study was conducted to understand the state of research on applications of Knowledge-based View in franchise systems. First, we used SALSA (Search, Appraisal, Synthesis, and Analysis), a simple systematic data search method, to obtain 61 sample papers. Second, the citations of authors and publications were analyzed using the bibliometric method to understand the authors and the publications that had the most impact as well as the trend of current studies in the field of knowled...

  20. Effects of toluene on protein synthesis and the interaction with ethanol in hepatocytes isolated from fed and fasted rats

    International Nuclear Information System (INIS)

    Smith-Kielland, A.; Ripel, Aa.; Gadeholt, G.

    1989-01-01

    The effects of three different concentrations (about 20, 100 and 1000 μM) of toluene on protein synthesis were studied in hepatocytes isolated from fed and fasted rats after 60 and 120 min. of incubation. The interaction between ethanol (60 mM) and the low and high toluene concentrations were also tested. To measure protein synthesis, 14 C-valine was used as the precursor amino acid. Total valine concentration was 2 mM to ensure near-constant specific radioactivity of precursor. Toluene concentrations were measured by head-space gas chromatography. Protein synthesis was unchanged in the presence of low toluene concentrations. Intermediate toluene concentration decreased protein synthesis by about 20% and high toluene concentration decreased protein synthesis by about 60%. Protein synthesis was similar in cells from fed and fasted rats. Ethanol alone inhibited protein synthesis by 20-30%, more in fasted than in fed rats. Toluene and ethanol in combination inhibited protein synthesis additively. The high toluene concentration with or without ethanol appeared to inhibit synthesis/secretion of export proteins in hepatocytes from fasted rats. In conclusion, our study indicates that toluene in relatively high concentrations inhibits general protein synthesis in isolated rat hepatocytes. Toluene and ethanol seems to inhibit protein synthesis additively. (author)

  1. Effects of toluene on protein synthesis and the interaction with ethanol in hepatocytes isolated from fed and fasted rats

    Energy Technology Data Exchange (ETDEWEB)

    Smith-Kielland, A.; Ripel, Aa.; Gadeholt, G.

    1989-01-01

    The effects of three different concentrations (about 20, 100 and 1000 ..mu..M) of toluene on protein synthesis were studied in hepatocytes isolated from fed and fasted rats after 60 and 120 min. of incubation. The interaction between ethanol (60 mM) and the low and high toluene concentrations were also tested. To measure protein synthesis, /sup 14/C-valine was used as the precursor amino acid. Total valine concentration was 2 mM to ensure near-constant specific radioactivity of precursor. Toluene concentrations were measured by head-space gas chromatography. Protein synthesis was unchanged in the presence of low toluene concentrations. Intermediate toluene concentration decreased protein synthesis by about 20% and high toluene concentration decreased protein synthesis by about 60%. Protein synthesis was similar in cells from fed and fasted rats. Ethanol alone inhibited protein synthesis by 20-30%, more in fasted than in fed rats. Toluene and ethanol in combination inhibited protein synthesis additively. The high toluene concentration with or without ethanol appeared to inhibit synthesis/secretion of export proteins in hepatocytes from fasted rats. In conclusion, our study indicates that toluene in relatively high concentrations inhibits general protein synthesis in isolated rat hepatocytes. Toluene and ethanol seems to inhibit protein synthesis additively.

  2. Gravity with Intermediate Goods Trade

    Directory of Open Access Journals (Sweden)

    Sujin Jang

    2017-12-01

    Full Text Available This paper derives the gravity equation with intermediate goods trade. We extend a standard monopolistic competition model to incorporate intermediate goods trade, and show that the gravity equation with intermediates trade is identical to the one without it except in that gross output should be used as the output measure instead of value added. We also show that the output elasticity of trade is significantly underestimated when value added is used as the output measure. This implies that with the conventional gravity equation, the contribution of output growth can be substantially underestimated and the role of trade costs reduction can be exaggerated in explaining trade expansion, as we demonstrate for the case of Korea's trade growth between 1995 and 2007.

  3. Development of catalytic materials for the synthesis of valuable chemical products via multifunctional and multisite reactions

    International Nuclear Information System (INIS)

    Apesteguia, C.R; Padro, C.L; Diez, V.K; Di Cosimo, J.I; Trasarti, A.F; Marchi, A.J

    2004-01-01

    This work reports on the successful development of solid catalytic materials carried out by our working group to obtain fine high yield chemical products. Specifically, a report is made of i) the development of metal/acid bi-functional catalysts to obtain racemic menthol from citral in a one step liquid phase process. This menthol is one of the most important chemical flavouring compounds in industry; ii) The use of acid zeolites containing a balanced concentration of Bronsted and Lewis heavy acid sites, which allow the selective synthesis of o-hydroxy acetophenone from the gas phase acylation of phenol with acetic acid. The o-hydroxy acetophenone is an intermediate compound in the production of 4-hydroxy coumarin and warfarin that are used as anticoagulants drugs; iii) The use of mixed MgAl x O y oxides containing dual acid-basic sites (Mg 2- O 2- and Al 3+ -O 2- ) to synthesize isoforone from acetone in gas phase. The isoforone is an intermediate key in the synthesis of vitamin E (CW)

  4. Action taken by ENRESA and the NPPs with a view to reducing the production of low and intermediate level wastes

    International Nuclear Information System (INIS)

    Morales, A.; Rojo, F.

    1996-01-01

    In those countries in which the responsibilities of the different organizations involved in the management of low and intermediate level radioactive wastes (Regulatory Body, Agency, Facility Operators and Producers) are perfectly defined and a definitive Waste Disposal Facility is in operation, the next phase in order of importance consists of addressing a waste volume reduction policy aimed at optimizing storage capacity

  5. Using Peephole Optimization on Intermediate Code

    NARCIS (Netherlands)

    Tanenbaum, A.S.; van Staveren, H.; Stevenson, J.W.

    1982-01-01

    Many portable compilers generate an intermediate code that is subsequently translated into the target machine's assembly language. In this paper a stack-machine-based intermediate code suitable for algebraic languages (e.g., PASCAL, C, FORTRAN) and most byte-addressed mini- and microcomputers is

  6. Pair production of intermediate vector bosons

    International Nuclear Information System (INIS)

    Mikaelian, K.O.

    1979-01-01

    The production of intermediate vector boson pairs W + W - , Z 0 Z 0 , W +- Z 0 and W +- γ in pp and p anti p collisions is discussed. The motivation is to detect the self-interactions among the four intermediate vector bosons

  7. Automated synthesis of the estrogen receptors imaging agent 18F-FES

    International Nuclear Information System (INIS)

    Guo Shen; Chen Guobao; Dai Hongfeng; Lin Meifu; Chen Wenxin

    2011-01-01

    Objective: 18 F-16α-17β-fluoroestradiol ( 18 F-FES), an estrogen receptors imaging agent, is synthesized with Tracerlab FX FN system. Methods: 18 F-FES is obtained by two steps reactions, including the nucleophilic displacement reaction of no-carrier-added 18 F-fluoride with 3-O-methoxymethyl-16, 17-O-sulfuryl-16-epiesteriol, then the intermediate is evaporated and hydrolyzed with HCI and finally gives 18 F-FES. Results: The synthesis of 18 F-FES can be completed in about 80 min.The radiochemical yield and radio-chemical purity are about 10% and 95% respectively. Conclusion: The procedure of synthesis is simple and automatical. 18 F-FES has an extremely low toxicity, which suggests that 18 F-FES may be a safe, a nd effective estrogen receptors imaging agent. (authors)

  8. Synthesis of Heterocycles through a Ruthenium‐Catalyzed Tandem Ring‐Closing Metathesis/Isomerization/N‐Acyliminium Cyclization Sequence

    DEFF Research Database (Denmark)

    Ascic, Erhad; Jensen, Jakob Feldthusen; Nielsen, Thomas Eiland

    2011-01-01

    Tandem bicycle: In the title reaction double bonds created during ring-closing metathesis isomerize to generate reactive iminium intermediates that undergo intramolecular cyclization reactions with tethered heteroatom and carbon nucleophiles. In this way, a series of biologically interesting hete...... heterocyclic compounds can be made, including a known precursor for the total synthesis of the antiparasitic natural product harmicine....

  9. Synthesis of heterocycles through transition-metal-catalyzed isomerization reactions

    DEFF Research Database (Denmark)

    Ishøy, Mette; Nielsen, Thomas Eiland

    2014-01-01

    of structurally complex and diverse heterocycles. In this Concept article, we attempt to cover this area of research through a selection of recent versatile examples. A sea of opportunities! Transition-metal-catalyzed isomerization of N- and O-allylic compounds provides a mild, selective and synthetically...... versatile method to form iminium and oxocarbenium ions. Given the number of reactions involving these highly electrophilic intermediates, this concept provides a sea of opportunities for heterocycle synthesis, (see scheme; Nu=nucleophile). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim....

  10. Localization of the terminal steps of O-antigen synthesis in Salmonella typhimurium

    International Nuclear Information System (INIS)

    McGrath, B.C.; Osborn, M.J.

    1991-01-01

    Previous immunoelectron microscopic studies have shown that both the final intermediate in O-antigen synthesis, undecaprenol-linked O polymer, and newly synthesized O-antigenic lipopolysaccharide are localized to the periplasmic face of the inner membrane. In vivo pulse-chase experiments now provide further evidence that attachment of O antigen to core lipopolysaccharide, as well as polymerization of O-specific polysaccharide chains, takes place at the periplasmic face of the membrane. Mutants doubly conditional in lipopolysaccharide synthesis [kdsA(Ts) pmi] were constructed in which synthesis of core lipopolysaccharide and O antigen are temperature sensitive and mannose dependent, respectively. Periplasmic orientation of O antigen:core lipopolysaccharide ligase was established by experiments showing rapid chase of undecaprenol-linked O polymer, previously accumulated at 42 degrees C in the absence of core synthesis, into lipopolysaccharide following resumption of core formation at 30 degrees C. In addition, chase of the monomeric O-specific tetrasaccharide unit into lipopolysaccharide was found in similar experiments in an O-polymerase-negative [rfc kdsA(Ts) pmi] mutant, suggesting that polymerization of O chains also occurs at the external face of the inner membrane

  11. Response to Reactive Nitrogen Intermediates in Mycobacterium tuberculosis: Induction of the 16-Kilodalton α-Crystallin Homolog by Exposure to Nitric Oxide Donors

    OpenAIRE

    Garbe, T. R.; Hibler, N. S.; Deretic, V.

    1999-01-01

    In contrast to the apparent paucity of Mycobacterium tuberculosis response to reactive oxygen intermediates, this organism has evolved a specific response to nitric oxide challenge. Exposure of M. tuberculosis to NO donors induces the synthesis of a set of polypeptides that have been collectively termed Nox. In this work, the most prominent Nox polypeptide, Nox16, was identified by immunoblotting and by N-terminal sequencing as the α-crystallin-related, 16-kDa small heat shock protein, sHsp16...

  12. Synthesis of the C(18)-C(34) fragment of amphidinolide C and the C(18)-C(29) fragment of amphidinolide F.

    Science.gov (United States)

    Roy, Sudeshna; Spilling, Christopher D

    2010-11-19

    A convergent synthesis of the C(18)-C(34) fragment of amphidinolide C and the C(18)-C(29) fragment of amphidinolide F is reported. The approach involves the synthesis of the common intermediate tetrahydrofuranyl-β-ketophosphonate via cross metathesis, Pd(0)-catalyzed cyclization, and hydroboration-oxidation. The β-ketophosphonate was coupled to three side chain aldehydes using a Horner-Wadsworth-Emmons (HWE) olefination reaction to give dienones, which were reduced with l-selectride to give the fragments of amphidinolide C and F.

  13. Combinatorial synthesis of natural products

    DEFF Research Database (Denmark)

    Nielsen, John

    2002-01-01

    Combinatorial syntheses allow production of compound libraries in an expeditious and organized manner immediately applicable for high-throughput screening. Natural products possess a pedigree to justify quality and appreciation in drug discovery and development. Currently, we are seeing a rapid...... increase in application of natural products in combinatorial chemistry and vice versa. The therapeutic areas of infectious disease and oncology still dominate but many new areas are emerging. Several complex natural products have now been synthesised by solid-phase methods and have created the foundation...... for preparation of combinatorial libraries. In other examples, natural products or intermediates have served as building blocks or scaffolds in the synthesis of complex natural products, bioactive analogues or designed hybrid molecules. Finally, structural motifs from the biologically active parent molecule have...

  14. Language in use intermediate : classroom book

    CERN Document Server

    Doff, Adrian

    1995-01-01

    ach of the four levels comprises about 80 hours of class work, with additional time for the self-study work. The Teacher's Book contains all the pages from the Classroom Book, with interleaved teaching notes including optional activities to cater for different abilities. There is a video to accompany the Beginner, Pre-intermediate and Intermediate levels. Each video contains eight stimulating and entertaining short programmes, as well as a booklet of photocopiable activities. Free test material is available in booklet and web format for Beginner and Pre-intermediate levels. Visit www.cambridge.org/elt/liu or contact your local Cambridge University Press representative.

  15. Language in use intermediate : teacher's book

    CERN Document Server

    Doff, Adrian

    1998-01-01

    Each of the four levels comprises about 80 hours of class work, with additional time for the self-study work. The Teacher's Book contains all the pages from the Classroom Book, with interleaved teaching notes including optional activities to cater for different abilities. There is a video to accompany the Beginner, Pre-intermediate and Intermediate levels. Each video contains eight stimulating and entertaining short programmes, as well as a booklet of photocopiable activities. Free test material is available in booklet and web format for Beginner and Pre-intermediate levels. Visit www.cambridge.org/elt/liu or contact your local Cambridge University Press representative.

  16. Whereas Short-Term Facilitation Is Presynaptic, Intermediate-Term Facilitation Involves Both Presynaptic and Postsynaptic Protein Kinases and Protein Synthesis

    Science.gov (United States)

    Jin, Iksung; Kandel, Eric R.; Hawkins, Robert D.

    2011-01-01

    Whereas short-term plasticity involves covalent modifications that are generally restricted to either presynaptic or postsynaptic structures, long-term plasticity involves the growth of new synapses, which by its nature involves both pre- and postsynaptic alterations. In addition, an intermediate-term stage of plasticity has been identified that…

  17. Interpretation and code generation based on intermediate languages

    DEFF Research Database (Denmark)

    Kornerup, Peter; Kristensen, Bent Bruun; Madsen, Ole Lehrmann

    1980-01-01

    The possibility of supporting high level languages through intermediate languages to be used for direct interpretation and as intermediate forms in compilers is investigated. An accomplished project in the construction of an interpreter and a code generator using one common intermediate form...

  18. Synthesis of 1,1-Diphenylethylene (DPE): The Marriage of a Grignard Reaction and a Column Chromatography Experiment

    Science.gov (United States)

    Alty, Lisa T.; France, Marcia B.; Alty, Isaac G.; Saber, Christine A.; Smith, Donna M.

    2016-01-01

    The synthesis of 1,1-diphenylethylene (DPE) via a Grignard reaction, followed by an acid-catalyzed dehydration reaction, yields a mixture of compounds. DPE is a high boiling liquid that cannot be purified using simple distillation. However, it is easily separated from the more polar starting material and intermediate alcohol using both thin layer…

  19. A novel chemo-enzymatic synthesis of hydrophilic phytosterol derivatives.

    Science.gov (United States)

    He, Wen-Sen; Hu, Di; Wang, Yu; Chen, Xue-Yan; Jia, Cheng-Sheng; Ma, Hai-Le; Feng, Biao

    2016-02-01

    In this study, a novel method was developed for chemo-enzymatic synthesis of hydrophilic phytosterol derivatives, phytosteryl polyethylene glycol succinate (PPGS), through an intermediate phytosteryl hemisuccinate (PSHS), which was first chemically prepared and subsequently coupled with polyethylene glycol (PEG) through lipase-catalyzed esterification. The chemical structure of intermediate and goal product were finally confirmed to be PSHS and PPGS by FT-IR, MS and NMR, suggesting that hydrophilic phytosterol derivatives were successfully synthesized. The effects of various parameters on the conversion of PSHS to PPGS were investigated and the highest conversion (>78%) was obtained under the selected conditions: 75 mmol/L PSHS, 1:2M ratio of PSHS to PEG, 50 g/L Novozym 435, 120 g/L 3 Å molecular sieves in tert-butanol, 55 °C, 96 h and 200 rpm. The solubility of phytosterols in water was significantly improved by coupling with PEG, facilitating the incorporation into a variety of foods containing water. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. THE CONTRIBUTIONS OF INTERACTIVE BINARY STARS TO DOUBLE MAIN-SEQUENCE TURNOFFS AND DUAL RED CLUMP OF INTERMEDIATE-AGE STAR CLUSTERS

    International Nuclear Information System (INIS)

    Yang Wuming; Bi Shaolan; Tian Zhijia; Li Tanda; Liu Kang; Meng Xiangcun

    2011-01-01

    Double or extended main-sequence turnoffs (DMSTOs) and dual red clump (RC) were observed in intermediate-age clusters, such as in NGC 1846 and 419. The DMSTOs are interpreted as that the cluster has two distinct stellar populations with differences in age of about 200-300 Myr but with the same metallicity. The dual RC is interpreted as a result of a prolonged star formation. Using a stellar population-synthesis method, we calculated the evolution of a binary-star stellar population. We found that binary interactions and merging can reproduce the dual RC in the color-magnitude diagrams of an intermediate-age cluster, whereas in actuality only a single population exists. Moreover, the binary interactions can lead to an extended main-sequence turnoff (MSTO) rather than DMSTOs. However, the rest of the main sequence, subgiant branch, and first giant branch are hardly spread by the binary interactions. Part of the observed dual RC and extended MSTO may be the results of binary interactions and mergers.

  1. Inhibition and recovery of semiconservative DNA synthesis in normal and solar UV sensitive ICR 2A frog cell lines following the induction of non-dimer DNA damage by sunlamp UV > 315 nm

    Energy Technology Data Exchange (ETDEWEB)

    Rosenstein, B.S. (Brown Univ., Providence, RI (USA). Dept. of Radiation Medicine)

    1989-08-01

    Cultures of solar UV-sensitive cell lines DRP 36 and DRP 153, and of the parental ICR 2A cell line, were exposed to 150 kJ/m{sup 2} of sunlamp UV>315nm plus photoreactivating light, resulting in the induction primarily of non-dimer DNA damage. Following either 0, 3, 6, 12 or 24 h incubation, cultures were pulse-labelled with ({sup 3}H) thymidine, and the synthesis of different size classes of replicon intermediates measured using alkaline step elution assay. For all three cell lines tested, an immediate depression of low molecular weight DNA synthesis was observed, followed by inhibition of all size classes of replicon intermediates. Within 12 h following irradiation, recovery of DNA synthesis was observed, generally most apparent for low molecular weight DNA. The ICR 2A cells exhibited a nearly full recovery in all size classes of DNA synthesized by 24 h. A much smaller recovery of continued inhibition was primarily in the synthesis of full replicon size DNA, and most pronounced for DRP 36 cells. (author).

  2. Srs2 mediates PCNA-SUMO-dependent inhibition of DNA repair synthesis

    International Nuclear Information System (INIS)

    Burkovics, Peter; Sebesta, Marek; Kolesar, Peter; Sisakova, Alexandra; Marini, Victoria; Plault, Nicolas; Szukacsov, Valeria; Pinter, Lajos; Haracska, Lajos; Robert, Thomas; Kolesar, Peter; Gangloff, Serge; Krejci, Lumir

    2013-01-01

    Completion of DNA replication needs to be ensured even when challenged with fork progression problems or DNA damage. PCNA and its modifications constitute a molecular switch to control distinct repair pathways. In yeast, SUMOylated PCNA (S-PCNA) recruits Srs2 to sites of replication where Srs2 can disrupt Rad51 filaments and prevent homologous recombination (HR). We report here an unexpected additional mechanism by which S-PCNA and Srs2 block the synthesis-dependent extension of a recombination intermediate, thus limiting its potentially hazardous resolution in association with a cross-over. This new Srs2 activity requires the SUMO interaction motif at its C-terminus, but neither its translocase activity nor its interaction with Rad51. Srs2 binding to S-PCNA dissociates Polδ and Polη from the repair synthesis machinery, thus revealing a novel regulatory mechanism controlling spontaneous genome rearrangements. Our results suggest that cycling cells use the Siz1-dependent SUMOylation of PCNA to limit the extension of repair synthesis during template switch or HR and attenuate reciprocal DNA strand exchanges to maintain genome stability. (authors)

  3. Synthesis of cyclopentadiene-fused chromanones via one-pot multicomponent reactions.

    Science.gov (United States)

    Ghandi, Mehdi; Ghomi, Ali-Tabatabaei; Kubicki, Maciej

    2013-03-15

    We have developed one-pot method for the synthesis of functionalized novel cyclopentadiene-fused chromanone scaffolds. A variety of 4-oxo-2,4-dihydrocyclopenta[c]chromene-1,2-dicarboxylates were obtained in moderate to good yields via condensation of 2-hydroxybenzaldehydes and ethyl acetoacetate with 1:1 acetylenecarboxylate-isocyanides in toluene. These reactions presumably proceed via reaction of the in situ generated 3-acetyl-2H-chromen-2-ones with acetylenecarboxylate-isocyanide zwitterionic intermediates through Michael addition/intramolecular cyclization and double [1,5] acyl shift rearrangement cascade.

  4. Search for intermediate vector bosons

    International Nuclear Information System (INIS)

    Cline, D.B.; Rubbia, C.; van der Meer, S.

    1982-01-01

    Over the past 15 years a new class of unified theories has been developed to describe the forces acting between elementary particles. The most successful of the new theories establishes a link between electromagnetism and the weak force. A crucial prediction of this unified electroweak theory is the existence of three massive particles called intermediate vector bosons. If these intermediate vector bosons exist and if they have properties attributed to them by electroweak theory, they should soon be detected, as the world's first particle accelerator with enough energy to create such particles has recently been completed at the European Organization for Nuclear Research (CERN) in Geneva. The accelerator has been converted to a colliding beam machine in which protons and antiprotons collide head on. According to electroweak theory, intermediate vector bosons can be created in proton-antiproton collisions. (SC)

  5. 39 CFR 3001.39 - Intermediate decisions.

    Science.gov (United States)

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Intermediate decisions. 3001.39 Section 3001.39 Postal Service POSTAL REGULATORY COMMISSION PERSONNEL RULES OF PRACTICE AND PROCEDURE Rules of General Applicability § 3001.39 Intermediate decisions. (a) Initial decision by presiding officer. In any proceedings in...

  6. 42 CFR 54.12 - Treatment of intermediate organizations.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Treatment of intermediate organizations. 54.12... intermediate organizations. If a nongovernmental organization (referred to here as an “intermediate organization”), acting under a contract or other agreement with the Federal Government or a State or local...

  7. Formation, structure, and stability of MHD intermediate shocks

    International Nuclear Information System (INIS)

    Wu, C.C.

    1990-01-01

    Contrary to the usual belief that MHD intermediate shocks are extraneous, the author has recently shown by numerical solutions of dissipative MHD equations that intermediate shocks are admissible and can be formed through nonlinear wave steepening from continuous waves. In this paper, the formation, structure and stability of intermediate shocks in dissipative MHD are considered in detail. The differences between the conventional theory and his are pointed out and clarified. He shows that all four types of intermediate shocks can be formed from smooth waves. He also shows that there are free parameters in the structure of the intermediate shocks, and that these parameters are related to the shock stability. In addition, he shows that a rotational discontinuity can not exist with finite width, indicate how this is related to the existence of time-dependent intermediate shocks, and show why the conventional theory is not a good approximation to dissipative MHD solutions whenever there is rotation in magnetic field

  8. Sterol partitioning by HMGR and DXR for routing intermediates toward withanolide biosynthesis.

    Science.gov (United States)

    Singh, Shefali; Pal, Shaifali; Shanker, Karuna; Chanotiya, Chandan Singh; Gupta, Madan Mohan; Dwivedi, Upendra Nath; Shasany, Ajit Kumar

    2014-12-01

    Withanolides biosynthesis in the plant Withania somnifera (L.) Dunal is hypothesized to be diverged from sterol pathway at the level of 24-methylene cholesterol. The conversion and translocation of intermediates for sterols and withanolides are yet to be characterized in this plant. To understand the influence of mevalonate (MVA) and 2-C-methyl-d-erythritol-4-phosphate (MEP) pathways on sterols and withanolides biosynthesis in planta, we overexpressed the WsHMGR2 and WsDXR2 in tobacco, analyzed the effect of transient suppression through RNAi, inhibited MVA and MEP pathways and fed the leaf tissue with different sterols. Overexpression of WsHMGR2 increased cycloartenol, sitosterol, stigmasterol and campesterol compared to WsDXR2 transgene lines. Increase in cholesterol was, however, marginally higher in WsDXR2 transgenic lines. This was further validated through transient suppression analysis, and pathway inhibition where cholesterol reduction was found higher due to WsDXR2 suppression and all other sterols were affected predominantly by WsHMGR2 suppression in leaf. The transcript abundance and enzyme analysis data also correlate with sterol accumulation. Cholesterol feeding did not increase the withanolide content compared to cycloartenol, sitosterol, stigmasterol and campesterol. Hence, a preferential translocation of carbon from MVA and MEP pathways was found differentiating the sterols types. Overall results suggested that MVA pathway was predominant in contributing intermediates for withanolides synthesis mainly through the campesterol/stigmasterol route in planta. © 2014 Scandinavian Plant Physiology Society.

  9. Preferential Hyperacuity Perimeter (PreView PHP) for detecting choroidal neovascularization study.

    Science.gov (United States)

    Alster, Yair; Bressler, Neil M; Bressler, Susan B; Brimacombe, Judith A; Crompton, R Michael; Duh, Yi-Jing; Gabel, Veit-Peter; Heier, Jeffrey S; Ip, Michael S; Loewenstein, Anat; Packo, Kirk H; Stur, Michael; Toaff, Techiya

    2005-10-01

    To assess the ability of the Preferential Hyperacuity Perimeter (PreView PHP; Carl Zeiss Meditec, Dublin, CA) to detect recent-onset choroidal neovascularization (CNV) resulting from age-related macular degeneration (AMD) and to differentiate it from an intermediate stage of AMD. Prospective, comparative, concurrent, nonrandomized, multicenter study. Eligible participants' study eyes had a corrected visual acuity of 20/160 or better and either untreated CNV from AMD diagnosed within the last 60 days or an intermediate stage of AMD. After obtaining consent, visual acuity with habitual correction, masked PHP testing, stereoscopic color fundus photography, and fluorescein angiography were performed. Photographs and angiograms were evaluated by graders masked to diagnosis and PHP results. The reading center's diagnosis determined if the patient was categorized as having intermediate AMD or neovascular AMD. A successful study outcome was defined a priori as a sensitivity of at least 80% and a specificity of at least 80%. Of 185 patients who gave consent to be enrolled, 11 (6%) had PHP results judged to be unreliable. An additional 52 were not included because they did not meet all eligibility criteria. Of the remaining 122 patients, 57 had an intermediate stage of AMD and 65 had neovascular AMD. The sensitivity to detect newly diagnosed CNV using PHP testing was 82% (95% confidence interval [CI], 70%-90%). The specificity to differentiate newly diagnosed CNV from the intermediate stage of AMD using PHP testing was 88% (95% CI, 76%-95%). Preferential Hyperacuity Perimeter testing can detect recent-onset CNV resulting from AMD and can differentiate it from an intermediate stage of AMD with high sensitivity and specificity. These data suggest that monitoring with PHP should detect most cases of CNV of recent onset with few false-positive results at a stage when treatment usually would be beneficial. Thus, this monitoring should be considered in the management of the

  10. Synthesis and Reactions of Five-Membered Heterocycles Using Phase Transfer Catalyst (PTC Techniques

    Directory of Open Access Journals (Sweden)

    Ahmed M. El-Sayed

    2014-01-01

    Full Text Available Phase transfer catalysts (PTCs have been widely used for the synthesis of organic compounds particularly in both liquid-liquid and solid-liquid heterogeneous reaction mixtures. They are known to accelerate reaction rates by facilitating formation of interphase transfer of species and making reactions between reagents in two immiscible phases possible. Application of PTC instead of traditional technologies for industrial processes of organic synthesis provides substantial benefits for the environment. On the basis of numerous reports it is evident that phase-transfer catalysis is the most efficient way for generation and reactions of many active intermediates. In this review we report various uses of PTC in syntheses and reactions of five-membered heterocycles compounds and their multifused rings.

  11. Partially folded intermediates during trypsinogen denaturation

    Directory of Open Access Journals (Sweden)

    Martins N.F.

    1999-01-01

    Full Text Available The equilibrium unfolding of bovine trypsinogen was studied by circular dichroism, differential spectra and size exclusion HPLC. The change in free energy of denaturation was = 6.99 ± 1.40 kcal/mol for guanidine hydrochloride and = 6.37 ± 0.57 kcal/mol for urea. Satisfactory fits of equilibrium unfolding transitions required a three-state model involving an intermediate in addition to the native and unfolded forms. Size exclusion HPLC allowed the detection of an intermediate population of trypsinogen whose Stokes radii varied from 24.1 ± 0.4 Å to 26.0 ± 0.3 Å for 1.5 M and 2.5 M guanidine hydrochloride, respectively. During urea denaturation, the range of Stokes radii varied from 23.9 ± 0.3 Å to 25.7 ± 0.6 Å for 4.0 M and 6.0 M urea, respectively. Maximal intrinsic fluorescence was observed at about 3.8 M urea with 8-aniline-1-naphthalene sulfonate (ANS binding. These experimental data indicate that the unfolding of bovine trypsinogen is not a simple transition and suggest that the equilibrium intermediate population comprises one intermediate that may be characterized as a molten globule. To obtain further insight by studying intermediates representing different stages of unfolding, we hope to gain a better understanding of the complex interrelations between protein conformation and energetics.

  12. Bacterial intermediate filaments

    DEFF Research Database (Denmark)

    Charbon, Godefroid; Cabeen, M.; Jacobs-Wagner, C.

    2009-01-01

    Crescentin, which is the founding member of a rapidly growing family of bacterial cytoskeletal proteins, was previously proposed to resemble eukaryotic intermediate filament (IF) proteins based on structural prediction and in vitro polymerization properties. Here, we demonstrate that crescentin...

  13. Metal Phosphates as Proton Conducting Materials for Intermediate Temperature Fuel Cell and Electrolyser Applications

    DEFF Research Database (Denmark)

    Anfimova, Tatiana

    The present thesis presents the results achieved during my ph.d. project on a subject of intermediate temperature proton conducting metal phosphates as electrolyte materials for fuel cells and electrolysers. Fuel cells and electrolysers are electrochemical devices with high energy conversion...... with a proton conductivity of above 10-2S cm-1. Chapter 1 of the thesis is an introduction to basics of fuel cell and electrolyser technologies as well as proton conducting materials. Extended discussion on the proton conducting materials, a particularly phosphates is made in Chapter 2. Three major types...... starts with synthesis and investigation of three rare earth metal phosphate hydrates, which is first presented in Chapter 5. Structural and surface water as well as its stability has been investigated using thermogravimetric and differential thermal analyses combined with structural modeling calculations...

  14. Intracellular synthesis of glutamic acid in Bacillus methylotrophicus SK19.001, a glutamate-independent poly(γ-glutamic acid)-producing strain.

    Science.gov (United States)

    Peng, Yingyun; Zhang, Tao; Mu, Wanmeng; Miao, Ming; Jiang, Bo

    2016-01-15

    Bacillus methylotrophicus SK19.001 is a glutamate-independent strain that produces poly(γ-glutamic acid) (γ-PGA), a polymer of D- and L-glutamic acids that possesses applications in food, the environment, agriculture, etc. This study was undertaken to explore the synthetic pathway of intracellular L- and D-glutamic acid in SK19.001 by investigating the effects of tricarboxylic acid cycle intermediates and different amino acids as metabolic precursors on the production of γ-PGA and analyzing the activities of the enzymes involved in the synthesis of L- and D-glutamate. Tricarboxylic acid cycle intermediates and amino acids could participate in the synthesis of γ-PGA via independent pathways in SK19.001. L-Aspartate aminotransferase, L-glutaminase and L-glutamate synthase were the enzymatic sources of L-glutamate. Glutamate racemase was responsible for the formation of D-glutamate for the synthesis of γ-PGA, and the synthetase had stereoselectivity for glutamate substrate. The enzymatic sources of L-glutamate were investigated for the first time in the glutamate-independent γ-PGA-producing strain, and multiple enzymatic sources of L-glutamate were verified in SK19.001, which will benefit efforts to improve production of γ-PGA with metabolic engineering strategies. © 2015 Society of Chemical Industry.

  15. Synthesis of substituted 1,4-diazepines and 1,5-benzodiazepines using an efficient heteropolyacid-catalyzed procedure.

    Science.gov (United States)

    Kaoua, Rachedine; Bennamane, Norah; Bakhta, Saliha; Benadji, Sihame; Rabia, Cherifa; Nedjar-Kolli, Bellara

    2010-12-28

    An efficient and improved procedure for the synthesis of 1,4-diazepine and 1,5-benzodiazepine derivatives via the reaction of ketimine intermediates with aldehydes in the presence of Keggin-type heteropolyacids (HPAs) was developed. High yields and short reaction times were obtained for both electron-releasing and electron-withdrawing substituted 1,4-diazepine  and 1,5-benzodiazepines derivatives.

  16. Synthesis of Substituted 1,4-Diazepines and 1,5-Benzodiazepines Using an Efficient Heteropolyacid-Catalyzed Procedure

    Directory of Open Access Journals (Sweden)

    Sihame Benadji

    2010-12-01

    Full Text Available An efficient and improved procedure for the synthesis of 1,4-diazepine and 1,5-benzodiazepine derivatives via the reaction of ketimine intermediates with aldehydes in the presence of Keggin-type heteropolyacids (HPAs was developed. High yields and short reaction times were obtained for both electron-releasing and electron-withdrawing substituted 1,4-diazepine  and 1,5-benzodiazepines derivatives.

  17. An exploration on the synthesis and bio-applications of derivatives ...

    African Journals Online (AJOL)

    Keeping in view of the importance of this organic moiety in the field of medicine and biology here an attempt has been made to review the synthesis and biological importance of heterocyclic Mannich base derivatives. Keywords: Amines, β-amino carbonyl compounds, Biological activity, Heterocyclic Mannich base derivative ...

  18. Methods for the thematic synthesis of qualitative research in systematic reviews

    Directory of Open Access Journals (Sweden)

    Harden Angela

    2008-07-01

    Full Text Available Abstract Background There is a growing recognition of the value of synthesising qualitative research in the evidence base in order to facilitate effective and appropriate health care. In response to this, methods for undertaking these syntheses are currently being developed. Thematic analysis is a method that is often used to analyse data in primary qualitative research. This paper reports on the use of this type of analysis in systematic reviews to bring together and integrate the findings of multiple qualitative studies. Methods We describe thematic synthesis, outline several steps for its conduct and illustrate the process and outcome of this approach using a completed review of health promotion research. Thematic synthesis has three stages: the coding of text 'line-by-line'; the development of 'descriptive themes'; and the generation of 'analytical themes'. While the development of descriptive themes remains 'close' to the primary studies, the analytical themes represent a stage of interpretation whereby the reviewers 'go beyond' the primary studies and generate new interpretive constructs, explanations or hypotheses. The use of computer software can facilitate this method of synthesis; detailed guidance is given on how this can be achieved. Results We used thematic synthesis to combine the studies of children's views and identified key themes to explore in the intervention studies. Most interventions were based in school and often combined learning about health benefits with 'hands-on' experience. The studies of children's views suggested that fruit and vegetables should be treated in different ways, and that messages should not focus on health warnings. Interventions that were in line with these suggestions tended to be more effective. Thematic synthesis enabled us to stay 'close' to the results of the primary studies, synthesising them in a transparent way, and facilitating the explicit production of new concepts and hypotheses

  19. ‘Umpolung’ Reactivity in Semiaqueous Amide and Peptide Synthesis

    Science.gov (United States)

    Shen, Bo; Makley, Dawn M.; Johnston, Jeffrey N.

    2010-01-01

    The amide functional group is one of Nature’s key functional and structural elements, most notably within peptides. Amides are also key intermediates in the preparation of a diverse range of therapeutic small molecules. Its construction using available methods focuses principally upon dehydrative approaches, although oxidative and radical-based methods are representative alternatives. During the carbon-nitrogen bond forming step in most every example, the carbon and nitrogen bear electrophilic and nucleophilic character, respectively. Here we show that activation of amines and nitroalkanes with an electrophilic iodine source in wet THF can lead directly to amide products. Preliminary observations support a mechanistic construct in which reactant polarity is reversed (umpolung) during C-N bond formation relative to traditional approaches. The use of nitroalkanes as acyl anion equivalents provides a conceptually innovative approach to amide and peptide synthesis, and one that might ultimately provide for efficient peptide synthesis that is fully reliant on enantioselective methods. PMID:20577205

  20. Alternating voltage-induced electrochemical synthesis of colloidal Au nanoicosahedra

    Energy Technology Data Exchange (ETDEWEB)

    McCann, Kevin; Cloud, Jacqueline E.; Yang, Yongan, E-mail: yonyang@mines.edu [Colorado School of Mines, Department of Chemistry and Geochemistry (United States)

    2013-11-15

    A simple method of alternating voltage-induced electrochemical synthesis has been developed to synthesize highly dispersed colloidal Au nanoicosahedra of 14 ± 3 nm in size. This simple and effective method uses a common transformer to apply a zero-offset alternating voltage to a pair of identical Au electrodes that are immersed in an electrolyte solution containing ligands. The obtained Au nanoicosahedra in this work are among the smallest Au icosahedra synthesized in aqueous solutions. A series of experimental conditions have been studied, such as voltage, the electrolyte identity and concentration, stabilizer identity and concentration, and reaction temperature. The mechanistic study indicates that Au nanoicosahedra are produced on electrode surfaces through an intermediate state of AuO{sub x}. The kinetic rate constant of these Au icosahedra in catalyzing the reduction of 4-nitrophenol with sodium borohydride is found much larger than the literature values of similar Au nanocrystals. In addition, the synthesis of Au–Pd-alloyed NCs has also been attempted.Graphical Abstract.

  1. Novel synthesis strategy for the preparation of individual phytosterol oxides.

    Science.gov (United States)

    Gao, Junlan; Yue, Qiulin; Ji, Yishun; Cheng, Beijiu; Zhang, Xin

    2013-01-30

    Sterols (cholesterol and phytosterols) are important structural components of cell membranes and major constituents of lipid metabolism. Research on their oxides, such as the factors affecting oxidation, oxides' structures, and qualitative and quantitative analysis, aroused more attention in this decade. However, the biological roles of individual phytosterol oxides are still unclear because no commercial individual phytosterol oxide standards are available. Different from the traditional chemical synthesis, in the present study, chemical synthesis from a starting phytosterol mixture followed with a semipreparative HPLC separation produced individual oxides. TLC and analytical HPLC were used here to not only monitor the reaction process but also specifically analyze the synthetic intermediates and oxides. The chromatographic results exhibited strict rules and similar characteristics. Finally, for the first time, four individual phytosterol oxides were successfully separated and collected by a semipreparative HPLC system, thus providing a novel strategy for the preparation of individual phytosterol oxides.

  2. Present status of intermediate band solar cell research

    International Nuclear Information System (INIS)

    Cuadra, L.; Marti, A.; Luque, A.

    2004-01-01

    The intermediate band solar cell is a theoretical concept with the potential for exceeding the performance of conventional single-gap solar cells. This novel photovoltaic converter bases its superior theoretical efficiency over single-gap solar cells by enhancing its photogenerated current, via the two-step absorption of sub-band gap photons, without reducing its output voltage. This is achieved through a material with an electrically isolated and partially filled intermediate band located within a higher forbidden gap. This material is commonly named intermediate band material. This paper centres on summarising the present status of intermediate band solar cell research. A number of attempts, which aim to implement the intermediate band concept, are being followed: the direct engineering of the intermediate band material, its implementation by means of quantum dots and the highly porous material approach. Among other sub-band gap absorbing proposals, there is a renewed interest on the impurity photovoltaic effect, the quantum well solar cells and the particularly promising proposal for the use of up- and down-converters

  3. A simple synthesis of L-[35S]cysteine sulfinic acid

    International Nuclear Information System (INIS)

    Spears, R.M.; Martin, D.L.

    1981-01-01

    The synthesis of L-[ 35 S]cysteine sulfinic acid (L-2-amino-3-[ 35 S]sulfino-propanoic acid) in 65% yield from S-[ 35 S]cystine is described. The procedure was designed for use with milligram quantities of starting material and requires no purification of intermediates. L-[ 35 S]Cystine was converted first to its thiosulfonate. Subsequent reaction of the thiosulfonate with ammonium hydroxide generated L-[ 35 S]cysteine sulfinic acid and L-[ 35 S]cystine as the major products. The L-[ 35 S]cystine was recovered and reprocessed thereby increasing the yield. (author)

  4. Synthesis of resorcinolic lipids bearing structural similarities to cytosporone A

    International Nuclear Information System (INIS)

    Santos, Edson dos Anjos dos; Beatriz, Adilson; Lima, Denis Pires de; Marques, Maria Rita; Leite, Carla Braga

    2009-01-01

    Inspired by the structure and biological activities of resorcinolic lipids and, particularly cytosporone A- a potent inhibitor of plantule germination and growth, we have performed the synthesis of the analogs 3-heptyl-3-hydroxy-5,7-dimethoxy-2-benzofuran-1(3H)-one (1) and 3-heptyl-3-hydroxy-4,6-dimethoxy-2-benzofuran-1(3H)-one (2). The intermediates and products were submitted to allelopathic test using Lactuca sativa L. seeds. Target compound 1 showed an inhibitory effect on germination and growth of hypocotyl and radicle in millimolar range. (author)

  5. Synthesis of resorcinolic lipids bearing structural similarities to cytosporone A

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Edson dos Anjos dos; Beatriz, Adilson; Lima, Denis Pires de [Universidade Federal Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Centro de Ciencias Exatas e Tecnologia. Dept. de Quimica], e-mail: dlima@nin.ufms.br; Marques, Maria Rita; Leite, Carla Braga [Universidade Federal Mato Grosso do Sul (UFMS), Campo Grande, MS (Brazil). Centro de Ciencias Biologicas. Dept. de Morfofisiologia

    2009-07-01

    Inspired by the structure and biological activities of resorcinolic lipids and, particularly cytosporone A- a potent inhibitor of plantule germination and growth, we have performed the synthesis of the analogs 3-heptyl-3-hydroxy-5,7-dimethoxy-2-benzofuran-1(3H)-one (1) and 3-heptyl-3-hydroxy-4,6-dimethoxy-2-benzofuran-1(3H)-one (2). The intermediates and products were submitted to allelopathic test using Lactuca sativa L. seeds. Target compound 1 showed an inhibitory effect on germination and growth of hypocotyl and radicle in millimolar range. (author)

  6. Synthesis of resorcinolic lipids bearing structural similarities to cytosporone A

    Directory of Open Access Journals (Sweden)

    Edson dos Anjos dos Santos

    2009-01-01

    Full Text Available Inspired by the structure and biological activities of resorcinolic lipids and, particularly cytosporone A- a potent inhibitor of plantule germination and growth, we have performed the synthesis of the analogs 3-heptyl-3-hydroxy-5,7-dimethoxy-2-benzofuran-1(3H-one (1 and 3-heptyl-3-hydroxy-4,6-dimethoxy-2-benzofuran-1(3H-one (2. The intermediates and products were submitted to allelopathic test using Lactuca sativa L. seeds. Target compound 1 showed an inhibitory effect on germination and growth of hypocotyl and radicle in milimolar range.

  7. Synthesis of radiolabelled aryl azides from diazonium salts: experimental and computational results permit the identification of the preferred mechanism.

    Science.gov (United States)

    Joshi, Sameer M; de Cózar, Abel; Gómez-Vallejo, Vanessa; Koziorowski, Jacek; Llop, Jordi; Cossío, Fernando P

    2015-05-28

    Experimental and computational studies on the formation of aryl azides from the corresponding diazonium salts support a stepwise mechanism via acyclic zwitterionic intermediates. The low energy barriers associated with both transition structures are compatible with very fast and efficient processes, thus making this method suitable for the chemical synthesis of radiolabelled aryl azides.

  8. An innovative view to the seismic hazard from strong Vrancea intermediate-depth earthquakes: the case studies of Bucharest (Romania) and Russe (Bulgaria)

    International Nuclear Information System (INIS)

    Panza, G.F.; Cioflan, C.; Marmureanu, G.; Kouteva, M.; Paskaleva, I.; Romanelli, F.

    2003-04-01

    An advanced procedure for ground motion modelling, capable of synthesizing the seismic ground motion from basic understanding of fault mechanism and seismic wave propagation, is applied to compute seismic signals at Bucharest (Romania) and Russe, NE Bulgaria, due to the seismic hazard from intermediate-depth Vrancea earthquakes. The theoretically obtained signals are successfully compared with the available observations. For both case studies site response estimates along selected geological cross sections are provided for three recent, strong and intermediate-depth, Vrancea earthquakes: August 30, 1986 and May 30 and 31, 1990. The applied ground motion modelling technique has proved that it is possible to investigate the local effects, taking into account both the seismic source and the propagation path effects. The computation of realistic seismic input, utilising the huge amount of geological, geophysical and geotechnical data, already available, goes well beyond the conventional deterministic approach and gives an economically valid scientific tool for seismic microzonation. (author)

  9. Flow synthesis of a versatile fructosamine mimic and quenching studies of a fructose transport probe

    Directory of Open Access Journals (Sweden)

    Matthew B. Plutschack

    2013-10-01

    Full Text Available We describe the synthesis of 1-amino-2,5-anhydro-D-mannose (“mannitolamine”, a key intermediate to the 7-nitro-1,2,3-benzadiazole conjugate (NBDM, using commercially available fluidic devices to increase the throughput. The approach is the first example of a flow-based Tiffeneau–Demjanov rearrangement. Performing this step in flow enables a ~64-fold throughput enhancement relative to batch. The flow process enables the synthesis to be accomplished three times faster than the comparable batch route. The high throughput enabled the production of larger quantities of the fluorescent fructose transport probe NBDM, enabling us to measure key photophysical properties that will facilitate future uptake studies.

  10. Rotavirus NSP2 interferes with the core lattice protein VP2 in initiation of minus-strand synthesis

    International Nuclear Information System (INIS)

    Vende, Patrice; Tortorici, M. Alejandra; Taraporewala, Zenobia F.; Patton, John T.

    2003-01-01

    The rotavirus nonstructural protein NSP2 self-assembles into stable octameric structures that possess nonspecific affinity for single-stranded (ss)RNA and RNA-RNA helix-destabilizing and NTPase activities. Furthermore, NSP2 is a component of replication intermediates with replicase activity and plays a critical role in the packaging and replication of the segmented dsRNA genome of rotavirus. To better understand the function of the protein in genome replication, we examined the effect that purified recombinant NSP2 had on the synthesis of dsRNA by the open core replication system. The results showed that NSP2 inhibited the synthesis of dsRNA from viral mRNA in vitro, in a concentration-dependent manner. The inhibition was overcome by adding increasing amounts of viral mRNA or nonviral ssRNA to the system, indicating that the inhibition was mediated by the nonspecific RNA-binding activity of NSP2. Further analysis revealed that NSP2 interfered with the ability of the open core proteins, GTP, and viral mRNA to form the initiation complex for (-) strand synthesis. Additional experiments indicated that NSP2 did not perturb recognition of viral mRNA by the viral RNA polymerase VP1, but rather interfered with the function of VP2, a protein that is essential for (-) strand initiation and dsRNA synthesis and that forms the T = 1 lattice of the virion core. In contrast to initiation, NSP2 did not inhibit (-) strand elongation. Collectively, the findings provide evidence that the temporal order of interaction of RNA-binding proteins with viral mRNA is a crucial factor impacting the formation of replication intermediates

  11. A Convenient Synthesis of Conjugated Acetylenic Ketones by Copper(l)-Catalyzed under Microwave Irradiation

    Institute of Scientific and Technical Information of China (English)

    WANG; JinXian

    2001-01-01

    Alkynyl ketones are useful precursors and intermediates in synthetic organic chemistry1 and has evoked considerable interest. A number of methods for the synthesis of conjugated acetylenic ketones involve the reaction a metal acetylide with an acyl chlorides or another carboxylic acid derivative have been developed 2. Recently, the synthesis of α, β-conjugated acetylenic ketones catalyzed by Pd(Ⅱ) or by copper(Ⅰ)pd(Ⅱ) reaction of 1-alkynes and acyl chlorides have been described. The acylation of terminal alkynes by acyl chlorides in the presence of catalytic amounts copper(Ⅰ) salts leading to α, β-conjugated acetylenic ketones has also been reported. However, many of these reactions suffer from lack of high pressure (17 atm), long reaction time (30 h)and require low temperatures (-78℃). Our work involves the synthesis of conjugated acetylenic ketones via the reaction of terminal alkynes with aroyl chlorides in the presence of cuprous iodide under microwave irradiation conditions.……

  12. A Convenient Synthesis of Conjugated Acetylenic Ketones by Copper(l)-Catalyzed under Microwave Irradiation

    Institute of Scientific and Technical Information of China (English)

    WANG JinXian; WEI BangGuo; ZHAO LianBiao; HU YuLai; KANG LiQing

    2001-01-01

    @@ Alkynyl ketones are useful precursors and intermediates in synthetic organic chemistry1 and has evoked considerable interest. A number of methods for the synthesis of conjugated acetylenic ketones involve the reaction a metal acetylide with an acyl chlorides or another carboxylic acid derivative have been developed 2. Recently, the synthesis of α, β-conjugated acetylenic ketones catalyzed by Pd(Ⅱ) or by copper(Ⅰ)pd(Ⅱ) reaction of 1-alkynes and acyl chlorides have been described. The acylation of terminal alkynes by acyl chlorides in the presence of catalytic amounts copper(Ⅰ) salts leading to α, β-conjugated acetylenic ketones has also been reported. However, many of these reactions suffer from lack of high pressure (17 atm), long reaction time (30 h)and require low temperatures (-78℃). Our work involves the synthesis of conjugated acetylenic ketones via the reaction of terminal alkynes with aroyl chlorides in the presence of cuprous iodide under microwave irradiation conditions.

  13. The synthesis of chlorophyll-a biosynthetic precursors and methyl substituted iron porphyrins

    International Nuclear Information System (INIS)

    Matera, K.M.

    1988-01-01

    The biosynthetic intermediates were incubated in a plant system. The activity levels calculated show that magnesium 6-acrylate porphyrins and one of the magnesium 6-β-hydroxypropionate porphyrins are not intermediates. In addition, plant systems incubated with 18 O 2 were found to synthesize magnesium 2,4-divinyl pheoporphyrin-a 5 incorporated with 18 O at the 9-carbonyl oxygen. Mass spectroscopy confirmed the presence of the oxygen label, thus eliminating one of two hypothesized pathways to chlorophyll-a. An overall description is given of iron porphyrins and iron porphyrin containing proteins. The function of the propionic side chains of the heme prosthetic group during electron transport reactions will be investigated. The synthesis of a series of iron(III) hexamethyl porphyrins with increasingly longer substituents in the remaining two peripheral positions of the porphyrin is described. Models for NMR studies of iron chlorin containing enzymes are discussed. Iron(III) pyropheophorbide-a and methyl pyropheophorbide-a were synthesized in addition to 5-CD 3 , 10-CD 2 iron(III) pyropheophorbide-a and methyl pyropheophorbide-a. Together, these pyropheophorbides were used to assign NMR resonances and ultimately provide a model for other iron chlorins. The synthesis of nickel(II) anhydro-mesorhodoporphyrin from zinc(III) anhydromesorhodochlorin is described; this nickel porphyrin was used as a standard for ring current calculations of reduced nickel analogs of anhydromesorhodoporphyrin

  14. Synthesis and characterization of Ag-Ni bimetallic nanoparticles by laser-induced plasma

    International Nuclear Information System (INIS)

    Xiao Qingmei; Yao Zhi; Liu Jiahong; Hai Ran; Oderji, Hassan Yousefi; Ding Hongbin

    2011-01-01

    We present an approach in which laser ablation deposition is used to synthesize silver-nickel bimetallic nanoparticles. A variety of techniques, including scanning electron microscopy, energy disperse spectroscopy and X-ray photoelectron spectroscopy have been used to characterize the morphology, composition and construction of synthesized bimetallic nanoparticles, respectively. The formation mechanism of bimetallic nanoparticles has been discussed. The Raman spectra of silver-nickel bimetallic nanoparticles have been analyzed. Time-of-flight mass spectrometry has been applied to directly measure intermediate species. The results indicate that diatomic AgNi is the most abundant species and suggest that the AgNi is the most stable intermediate which may play an important role in the synthesis process. Emission spectra demonstrate that the electron temperature is in the range of 6000-10000 K during the ablation process and increases with the laser power density.

  15. Vinylcyclopropylacyl and polyeneacyl radicals. Intramolecular ketene alkyl radical additions in ring synthesis.

    Science.gov (United States)

    De Boeck, Benoit; Herbert, Nicola M A; Harrington-Frost, Nicole M; Pattenden, Gerald

    2005-01-21

    Treatment of a variety of substituted vinylcyclopropyl selenyl esters, e.g. 11, with Bu(3)SnH-AIBN in refluxing benzene leads to the corresponding acyl radical intermediates, which undergo rearrangement and intramolecular cyclisations via their ketene alkyl radical equivalents producing cyclohexenones in 50-60% yield. By contrast, treatment of conjugated triene selenyl esters, e.g. 32, with Bu(3)SnH-AIBN produces substituted 2-cyclopentenones via intramolecular cyclisations of their ketene alkyl radical intermediates. Under the same radical-initiating conditions the selenyl esters derived from o-vinylbenzoic acid and o-vinylcinnamic acid undergo intramolecular cyclisations producing 1-indanone and 5,6-dihydrobenzocyclohepten-7-one respectively in 60-70% yields. A tandem radical cyclisation from the alpha,beta,gamma,delta-diene selenyl ester 31 provides an expeditious synthesis of the diquinane 35 in 69% yield.

  16. Synthesis of naphthalenes through three-component coupling of alkynes, Fischer carbene complexes, and benzaldehyde hydrazones via isoindole intermediates.

    Science.gov (United States)

    Duan, Shaofeng; Sinha-Mahapatra, Dilip K; Herndon, James W

    2008-04-17

    The synthesis of naphthalene derivatives through three-component coupling of 2-alkynylbenzaldehyde hydrazones with carbene complexes and electron-deficient alkynes has been examined. The reaction involves formation of an isoindole derivative, followed by intramolecular Diels-Alder reaction, followed by nitrene extrusion. The reaction was highly regioselective using unsymmetrical alkynes.

  17. Synthesis of Naphthalenes through Three-Component Coupling of Alkynes, Fischer Carbene Complexes, and Benzaldehyde Hydrazones via Isoindole Intermediates

    OpenAIRE

    Duan, Shaofeng; Sinha-Mahapatra, Dilip K.; Herndon, James W.

    2008-01-01

    The synthesis of naphthalene derivatives through three-component coupling of 2-alkynylbenzaldehyde hydrazones with carbene complexes and electron-deficient alkynes has been examined. The reaction involves formation of an isoindole derivative, followed by intramolecular Diels–Alder reaction, followed by nitrene extrusion. The reaction was highly regioselective using unsymmetrical alkynes.

  18. Investigation of phospholipid synthesis and the disposition of amino acid and carbohydrate

    International Nuclear Information System (INIS)

    Boehme, D.S.

    1986-01-01

    The synthesis of pulmonary phospholipids by offspring of diabetic female rats was assessed by means of high performance liquid chromatography combined with automated phosphate analysis. No changes in the pool sizes of the major phospholipids or their precursors were observed. However, offspring of both insulin-treated and untreated diabetic mothers displayed increased pulmonary lyso-phosphatidylcholine. The concentration of glycerylphosphorylcholine, the metabolic product of lyso-phosphatidylcholine, was also increased in these offspring, providing further evidence of a reduced reacylation pathway in the offspring of diabetic mothers. The concentration of phosphatidylglycerol was reduced in the lungs from offspring of diabetic mothers. Preliminary investigation suggested that the mechanism of insulin action on lungs from offspring of diabetic rats may be the diversion of substrate from lipid synthetic pathways into protein synthesis. The utilization of [14C]-labeled amino acids and carbohydrates by normal fetal rat lung, however, revealed no direct insulin effect on protein synthesis. The ability of the fetal lung to convert amino acids into Krebs Cycle intermediates was demonstrated

  19. Potent New Small-Molecule Inhibitor of Botulinum Neurotoxin Serotype A Endopeptidase Developed by Synthesis-Based Computer-Aided Molecular Design

    Science.gov (United States)

    2009-11-01

    simulations; (4) synthesis and evaluation of the molecules from Step 2 or 3 (e.g., synthesizing and testing AHP). From synthetic chemistry point of view...2000) Synthesis of 6H-indolo [2,3-b][1,6]naphthyridines and related compounds as the 5-Aza analogues of ellipticine alkaloids . J Org Chem 65: 7977–7983...Potent New Small-Molecule Inhibitor of Botulinum Neurotoxin Serotype A Endopeptidase Developed by Synthesis -Based Computer-Aided Molecular Design

  20. Dietary and fluid restrictions in CKD: a thematic synthesis of patient views from qualitative studies.

    Science.gov (United States)

    Palmer, Suetonia C; Hanson, Camilla S; Craig, Jonathan C; Strippoli, Giovanni F M; Ruospo, Marinella; Campbell, Katrina; Johnson, David W; Tong, Allison

    2015-04-01

    Managing the complex fluid and diet requirements of chronic kidney disease (CKD) is challenging for patients. We aimed to summarize patients' perspectives of dietary and fluid management in CKD to inform clinical practice and research. Systematic review of qualitative studies. Adults with CKD who express opinions about dietary and fluid management. MEDLINE, EMBASE, PsycINFO, CINAHL, Google Scholar, reference lists, and PhD dissertations were searched to May 2013. Thematic synthesis. We included 46 studies involving 816 patients living in middle- to high-income countries. Studies involved patients treated with facility-based and home hemodialysis (33 studies; 462 patients), peritoneal dialysis (10 studies; 112 patients), either hemodialysis or peritoneal dialysis (3 studies; 73 patients), kidney transplant recipients (9 studies; 89 patients), and patients with non-dialysis-dependent CKD stages 1 to 5 (5 studies; 80 patients). Five major themes were identified: preserving relationships (interference with roles, social limitations, and being a burden), navigating change (feeling deprived, disrupting held truths, breaking habits and norms, being overwhelmed by information, questioning efficacy, and negotiating priorities), fighting temptation (resisting impositions, experiencing mental invasion, and withstanding physiologic needs), optimizing health (accepting responsibility, valuing self-management, preventing disease progression, and preparing for and protecting a transplant), and becoming empowered (comprehending paradoxes, finding solutions, and mastering change and demands). Limited data in non-English languages and low-income settings and for adults with CKD not treated with hemodialysis. Dietary and fluid restrictions are disorienting and an intense burden for patients with CKD. Patient-prioritized education strategies, harnessing patients' motivation to stay well for a transplant or to avoid dialysis, and viewing adaptation to restrictions as a collaborative

  1. Associations of Systemic Diseases with Intermediate Uveitis.

    Science.gov (United States)

    Shoughy, Samir S; Kozak, Igor; Tabbara, Khalid F

    2016-01-01

    To determine the associations of systemic diseases with intermediate uveitis. The medical records of 50 consecutive cases with intermediate uveitis referred to The Eye Center in Riyadh, Saudi Arabia, were reviewed. Age- and sex-matched patients without uveitis served as controls. Patients had complete ophthalmic and medical examinations. There were 27 male and 23 female patients. Mean age was 29 years with a range of 5-62 years. Overall, 21 cases (42%) had systemic disorders associated with intermediate uveitis and 29 cases (58%) had no associated systemic disease. A total of 11 patients (22%) had asthma, 4 (8%) had multiple sclerosis, 3 (6%) had presumed ocular tuberculosis, 1 (2%) had inflammatory bowel disease, 1 (2%) had non-Hodgkin lymphoma and 1 (2%) had sarcoidosis. Evidence of systemic disease was found in 50 (5%) of the 1,000 control subjects. Bronchial asthma was found in 37 patients (3.7 %), multiple sclerosis in 9 patients (0.9%), inflammatory bowel disease in 3 patients (0.3%), and tuberculosis in 1 patient (0.1%). None of the control patients had sarcoidosis or lymphoma. There were statistically significant associations between intermediate uveitis and bronchial asthma (p = 0.0001), multiple sclerosis (p = 0.003) and tuberculosis (p = 0.0005). Bronchial asthma and multiple sclerosis were the most frequently encountered systemic diseases associated with intermediate uveitis in our patient population. Patients with intermediate uveitis should undergo careful history-taking and investigations to rule out associated systemic illness.

  2. Expertise concerning the request by the ZWILAG Intermediate Storage Facility Wuerenlingen AG for granting of a licence for the building and operation of the Central Intermediate Storage Facility for radioactive wastes

    International Nuclear Information System (INIS)

    1995-12-01

    On July 15, 1993, the Intermediate Storage Facility Wuerenlingen AG (ZWILAG) submitted a request to the Swiss Federal Council for granting of a license for the construction and operation of a central intermediate storage facility for radioactive wastes. The project foresees intermediate storage halls as well as conditioning and incineration installations. The Federal Agency for the Safety of Nuclear Installations (HSK) has to examine the project from the point of view of nuclear safety. The present report presents the results of this examination. Different waste types have to be treated in ZWILAG: spent fuel assemblies from Swiss nuclear power plants (KKWs); vitrified, highly radioactive wastes from reprocessing; intermediate and low-level radioactive wastes from KKWs and from reprocessing; wastes from the dismantling of nuclear installations; wastes from medicine, industry and research. The wastes are partitioned into three categories: high-level (HAA) radioactive wastes containing, amongst others, α-active nuclides, intermediate-level (MAA) radioactive wastes and low-level (SAA) radioactive wastes. The projected installation consists of three repository halls for each waste category, a hot cell, a conditioning plant and an incineration and melting installation. The HAA repository can accept 200 transport and storage containers with vitrified high-level wastes or spent fuel assemblies. The expected radioactivity amounts to 10 20 Bq, including 10 18 Bq of α-active nuclides. The thermal power produced by decay is released to the environment by natural circulation of air. The ventilation system is designed for a maximum power of 5.8 MW. Severe conditions are imposed to the containers as far as tightness and shielding against radiation is concerned. In the repository for MAA wastes the maximum radioactivity is 10 18 Bq with 10 15 Bq of α-active nuclides. The maximum thermal power of 250 kW is removed by forced air cooling. Because of the high level of radiation the

  3. Structural Analysis of Substrate, Reaction Intermediate, and Product Binding in Haemophilus influenzae Biotin Carboxylase

    Science.gov (United States)

    Broussard, Tyler C.; Pakhomova, Svetlana; Neau, David B.; Bonnot, Ross; Waldrop, Grover L.

    2015-01-01

    Acetyl-CoA carboxylase catalyzes the first and regulated step in fatty acid synthesis. In most Gram-negative and Gram-positive bacteria, the enzyme is composed of three proteins: biotin carboxylase, a biotin carboxyl carrier protein (BCCP), and carboxyltransferase. The reaction mechanism involves two half-reactions with biotin carboxylase catalyzing the ATP-dependent carboxylation of biotin-BCCP in the first reaction. In the second reaction, carboxyltransferase catalyzes the transfer of the carboxyl group from biotin-BCCP to acetyl-CoA to form malonyl-CoA. In this report, high-resolution crystal structures of biotin carboxylase from Haemophilus influenzae were determined with bicarbonate, the ATP analogue AMPPCP; the carboxyphosphate intermediate analogues, phosphonoacetamide and phosphonoformate; the products ADP and phosphate; and the carboxybiotin analogue N1′-methoxycarbonyl biotin methyl ester. The structures have a common theme in that bicarbonate, phosphate, and the methyl ester of the carboxyl group of N1′-methoxycarbonyl biotin methyl ester all bound in the same pocket in the active site of biotin carboxylase and as such utilize the same set of amino acids for binding. This finding suggests a catalytic mechanism for biotin carboxylase in which the binding pocket that binds tetrahedral phosphate also accommodates and stabilizes a tetrahedral dianionic transition state resulting from direct transfer of CO2 from the carboxyphosphate intermediate to biotin. PMID:26020841

  4. A green and efficient method for the synthesis of homodimeric (β ...

    African Journals Online (AJOL)

    ... derivatives by intramolecular cyclization in various yields. Of particular interest is the use of the water as solvent of reaction and in absence of catalyst. Also these operating conditions protect the environment and economic points of view. Keywords: aqueous synthesis; bioactivity; dihydropyridine; dimedone; green method; ...

  5. Synthesis of Naphthalenes through Three-Component Coupling of Alkynes, Fischer Carbene Complexes, and Benzaldehyde Hydrazones via Isoindole Intermediates

    Science.gov (United States)

    Duan, Shaofeng; Sinha-Mahapatra, Dilip K.; Herndon, James W.

    2008-01-01

    The synthesis of naphthalene derivatives through three-component coupling of 2-alkynylbenzaldehyde hydrazones with carbene complexes and electron-deficient alkynes has been examined. The reaction involves formation of an isoindole derivative, followed by intramolecular Diels–Alder reaction, followed by nitrene extrusion. The reaction was highly regioselective using unsymmetrical alkynes. PMID:18351767

  6. Effect of PVP Intermediate Layer on the Properties of SAPO 34 Membrane

    Directory of Open Access Journals (Sweden)

    Jugal K. Das

    2012-01-01

    Full Text Available SAPO 34 zeolite membranes were prepared on a tubular mullite support. Before membrane preparation, the support surfaces were coated with seed crystals. Seeds particles were prepared by hydrothermal synthesis. Before seeding, the substrates were treated with polyvinylpyrrolidone (PVP to orient the seeds. Both the treated and untreated supports were seeded, and membranes were synthesized on those support tubes by ex situ hydrothermal method. The PVP molecule exists in the two resonance structures. Hence the acylamino bond –N+ = C–O-– acts as intermediate linker between support surface and seed surface. Due to charge interaction, the seed crystals were anchored strongly to support surface. The synthesized membranes along with seed crystals were characterized by XRD, FESEM, and EDAX analysis. The single-gas permeation with CO2 and H2 was investigated. Up to 5 bar of feed pressure, the permselectivity of CO2 and H2 was as high as 4.2.

  7. Efficient and Scalable Synthesis of 4-Carboxy-Pennsylvania Green Methyl Ester: A Hydrophobic Building Block for Fluorescent Molecular Probes.

    Science.gov (United States)

    Woydziak, Zachary R; Fu, Liqiang; Peterson, Blake R

    2014-01-01

    Fluorinated fluorophores are valuable tools for studies of biological systems. However, amine-reactive single-isomer derivatives of these compounds are often very expensive. To provide an inexpensive alternative, we report a practical synthesis of 4-carboxy-Pennsylvania Green methyl ester. Derivatives of this hydrophobic fluorinated fluorophore, a hybrid of the dyes Oregon Green and Tokyo Green, are often cell permeable, enabling labeling of intracellular targets and components. Moreover, the low pKa of Pennsylvania Green (4.8) confers bright fluorescence in acidic cellular compartments such as endosomes, enhancing its utility for chemical biology investigations. To improve access to the key intermediate 2,7-difluoro-3,6-dihydroxyxanthen-9-one, we subjected bis-(2,4,5-trifluorophenyl)methanone to iterative nucleophilic aromatic substitution by hydroxide on scales of > 40 g. This intermediate was used to prepare over 15 grams of pure 4-carboxy-Pennsylvania Green methyl ester in 28% overall yield without requiring chromatography. This compound can be converted into the amine reactive N -hydroxysuccinimidyl ester in essentially quantitative yield for the synthesis of a wide variety of fluorescent molecular probes.

  8. A practical synthesis of long-chain iso-fatty acids (iso-C12–C19 and related natural products

    Directory of Open Access Journals (Sweden)

    Mark B. Richardson

    2013-09-01

    Full Text Available A gram-scale synthesis of terminally-branched iso-fatty acids (iso-C12–C19 was developed commencing with methyl undec-10-enoate (methyl undecylenate (for iso-C12–C14 or the C15 and C16 lactones pentadecanolide (for iso-C15–C17 and hexadecanolide (for iso-C18–C19. Central to the approaches outlined is the two-step construction of the terminal isopropyl group through addition of methylmagnesium bromide to the ester/lactones and selective reduction of the resulting tertiary alcohols. Thus, the C12, C17 and C18 iso-fatty acids were obtained in three steps from commercially-available starting materials, and the remaining C13–C16 and C19 iso-fatty acids were prepared by homologation or recursive dehomologations of these fatty acids or through intercepting appropriate intermediates. Highlighting the synthetic potential of the iso-fatty acids and various intermediates prepared herein, we describe the synthesis of the natural products (S-2,15-dimethylpalmitic acid, (S-2-hydroxy-15-methylpalmitic acid, and 2-oxo-14-methylpentadecane.

  9. Synthesis of In2O3nanoparticles by thermal decomposition of a citrate gel precursor

    International Nuclear Information System (INIS)

    Rey, J. F. Q.; Plivelic, T. S.; Rocha, R. A.; Tadokoro, S. K.; Torriani, I.; Muccillo, E. N. S.

    2005-01-01

    This paper describes the synthesis of indium oxide by a modified sol-gel method, and the study of thermal decomposition of the metal complex in air. The characterization of the intermediate as well as the final compounds was carried out by thermogravimetry, differential thermal analysis, Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and small angle X-ray scattering. The results show that the indium complex decomposes to In 2 O 3 with the formation of an intermediate compound. Nanoparticles of cubic In 2 O 3 with crystallite sizes in the nanosize range were formed after calcination at temperatures up to 900 deg. C. Calcined materials are characterized by a polydisperse distribution of spherical particles with sharp and smooth surfaces

  10. Catalytic Enantioselective Synthesis of 3,4-Unsubstituted Thiochromenes through Sulfa-Michael/Julia-Kocienski Olefination Cascade Reaction.

    Science.gov (United States)

    Simlandy, Amit Kumar; Mukherjee, Santanu

    2017-05-05

    A highly enantioselective cascade sulfa-Michael/Julia-Kocienski olefination reaction between 2-mercaptobenzaldehydes and β-substituted vinyl PT-sulfones has been realized for the synthesis of 3,4-unsubstituted 2H-thiochromenes. This reaction, catalyzed by diphenylprolinol TMS ether, proceeds through an aromatic iminium intermediate and furnishes a wide range of 2-substiuted 2H-thiochromenes with excellent enantioselectivities (up to 99:1 er).

  11. Flow microreactor synthesis of 2,2-disubstituted oxetanes via 2-phenyloxetan-2-yl lithium

    Directory of Open Access Journals (Sweden)

    Degennaro Leonardo

    2016-01-01

    Full Text Available A mild and sustainable synthesis of 2,2-disubstituted oxetanes has been achieved through the use of a flow microreactor system. By controlling the residence time a highly unstable intermediate such as 2-phenyloxetan-2-yl lithium can be generated and trapped with various electrophiles affording in moderate to good yields 2-substituted-2-phenyloxetanes at higher temperatures with respect to macrobatch-mode where –78 °C is required.

  12. Solid-Phase Synthesis of Oligodeoxynucleotides Containing N4-[2-(t-butyldisulfanylethyl]-5-methylcytosine Moieties

    Directory of Open Access Journals (Sweden)

    Sónia Pérez-Rentero

    2010-08-01

    Full Text Available An efficient route for the synthesis of the phosphoramidite derivative of 5-methylcytosine bearing a tert-butylsulfanyl group protected thiol is described. This building block is used for the preparation of oligonucleotides carrying a thiol group at the nucleobase at the internal position of a DNA sequence. The resulting thiolated oligonucleotides are useful intermediates to generate oligonucleotide conjugates carrying molecules of interest at internal positions of a DNA sequence.

  13. New and Efficient Synthesis of Amides from Acid Chlorides Using Diisobutyl(amino)aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jae Kyo; Shin, Won Kyu; An, Duk Keun [Kangwon National Univ., Chuncheon (Korea, Republic of)

    2013-05-15

    In conclusion, we have developed a facile, alternative method for the formation of secondary and tertiary amides including morpholine amides from acid chlorides by using diisobutyl(amino)aluminum under mild reaction conditions. The advantages of the present method include the high product yields, simple experimental procedure, short reaction time (10 min), and the fact that an excess amount of amine is not required. This result suggests that our new method can provide an alternative method for the synthesis of useful amides from acid chlorides. Amides are valuable functional groups in biological, agrochemical, and pharmaceutical molecules. Several amides such as Weinreb amides, morpholine amides, and pyrrolidine amides are useful intermediates for the synthesis of aldehydes or ketones. Among them, morpholine amides are a cheap and good substitute for Weinreb amides.

  14. New and Efficient Synthesis of Amides from Acid Chlorides Using Diisobutyl(amino)aluminum

    International Nuclear Information System (INIS)

    Park, Jae Kyo; Shin, Won Kyu; An, Duk Keun

    2013-01-01

    In conclusion, we have developed a facile, alternative method for the formation of secondary and tertiary amides including morpholine amides from acid chlorides by using diisobutyl(amino)aluminum under mild reaction conditions. The advantages of the present method include the high product yields, simple experimental procedure, short reaction time (10 min), and the fact that an excess amount of amine is not required. This result suggests that our new method can provide an alternative method for the synthesis of useful amides from acid chlorides. Amides are valuable functional groups in biological, agrochemical, and pharmaceutical molecules. Several amides such as Weinreb amides, morpholine amides, and pyrrolidine amides are useful intermediates for the synthesis of aldehydes or ketones. Among them, morpholine amides are a cheap and good substitute for Weinreb amides

  15. Parents' and informal caregivers' views and experiences of communication about routine childhood vaccination: a synthesis of qualitative evidence.

    Science.gov (United States)

    Ames, Heather Mr; Glenton, Claire; Lewin, Simon

    2017-02-07

    guidelines developed by the Cochrane Qualitative Research Methods Group for searching for qualitative evidence as well as modified versions of the search developed for three related reviews of effectiveness. There were no date or geographic restrictions for the search. We included studies that utilised qualitative methods for data collection and analysis; focused on the views and experiences of parents and informal caregivers regarding information about vaccination for children aged up to six years; and were from any setting globally where information about childhood vaccinations was communicated or distributed. We used maximum variation purposive sampling for data synthesis, using a three-step sampling frame. We conducted a thematic analysis using a constant comparison strategy for data extraction and synthesis. We assessed our confidence in the findings using the GRADE-CERQual approach. High confidence suggests that it is highly likely that the review finding is a reasonable representation of the phenomenon of interest, while very low confidence indicates that it is not clear whether the review finding is a reasonable representation of it. Using a matrix model, we then integrated our findings with those from other Cochrane reviews that assessed the effects of different communication strategies on parents' knowledge, attitudes and behaviour about childhood vaccination. We included 38 studies, mostly from high-income countries, many of which explored mothers' perceptions of vaccine communication. Some focused on the MMR (measles, mumps, rubella) vaccine.In general, parents wanted more information than they were getting (high confidence in the evidence). Lack of information led to worry and regret about vaccination decisions among some parents (moderate confidence).Parents wanted balanced information about vaccination benefits and harms (high confidence), presented clearly and simply (moderate confidence) and tailored to their situation (low confidence in the evidence

  16. Synthesis of the C(18)–C(34) Fragment of Amphidinolide C and the C(18)–C(29) Fragment of Amphidinolide F

    Science.gov (United States)

    Roy, Sudeshna; Spilling, Christopher D.

    2010-01-01

    A convergent synthesis of the C(18)–C(34) fragment of amphidinolide C and the C(18)–C(29) fragment of amphidinolide F is reported. The approach involves the synthesis of the common intermediate tetrahydrofuranyl-β-ketophosphonate via cross metathesis, Pd(0)-catalyzed cyclization and hydroboration-oxidation. The β-ketophosphonate was coupled to three side chain aldehydes using a Horner-Wadsworth-Emmons (HWE) olefination reaction to give dienones, which were reduced with L-selectride to give the fragments of amphidinolide C and F. PMID:21028791

  17. The synthesis paradigm in genetics.

    Science.gov (United States)

    Rice, William R

    2014-02-01

    Experimental genetics with model organisms and mathematically explicit genetic theory are generally considered to be the major paradigms by which progress in genetics is achieved. Here I argue that this view is incomplete and that pivotal advances in genetics--and other fields of biology--are also made by synthesizing disparate threads of extant information rather than generating new information from experiments or formal theory. Because of the explosive expansion of information in numerous "-omics" data banks, and the fragmentation of genetics into numerous subdisciplines, the importance of the synthesis paradigm will likely expand with time.

  18. Isoporphyrin Intermediate in Heme Oxygenase Catalysis

    Science.gov (United States)

    Evans, John P.; Niemevz, Fernando; Buldain, Graciela; de Montellano, Paul Ortiz

    2008-01-01

    Human heme oxygenase-1 (hHO-1) catalyzes the O2- and NADPH-dependent oxidation of heme to biliverdin, CO, and free iron. The first step involves regiospecific insertion of an oxygen atom at the α-meso carbon by a ferric hydroperoxide and is predicted to proceed via an isoporphyrin π-cation intermediate. Here we report spectroscopic detection of a transient intermediate during oxidation by hHO-1 of α-meso-phenylheme-IX, α-meso-(p-methylphenyl)-mesoheme-III, and α-meso-(p-trifluoromethylphenyl)-mesoheme-III. In agreement with previous experiments (Wang, J., Niemevz, F., Lad, L., Huang, L., Alvarez, D. E., Buldain, G., Poulos, T. L., and Ortiz de Montellano, P. R. (2004) J. Biol. Chem. 279, 42593–42604), only the α-biliverdin isomer is produced with concomitant formation of the corresponding benzoic acid. The transient intermediate observed in the NADPH-P450 reductase-catalyzed reaction accumulated when the reaction was supported by H2O2 and exhibited the absorption maxima at 435 and 930 nm characteristic of an isoporphyrin. Product analysis by reversed phase high performance liquid chromatography and liquid chromatography electrospray ionization mass spectrometry of the product generated with H2O2 identified it as an isoporphyrin that, on quenching, decayed to benzoylbiliverdin. In the presence of H218O2, one labeled oxygen atom was incorporated into these products. The hHO-1-isoporphyrin complexes were found to have half-lives of 1.7 and 2.4 h for the p-trifluoromethyl- and p-methyl-substituted phenylhemes, respectively. The addition of NADPH-P450 reductase to the H2O2-generated hHO-1-isoporphyrin complex produced α-biliverdin, confirming its role as a reaction intermediate. Identification of an isoporphyrin intermediate in the catalytic sequence of hHO-1, the first such intermediate observed in hemoprotein catalysis, completes our understanding of the critical first step of heme oxidation. PMID:18487208

  19. Studies of the kinetics and mechanisms of ammonia synthesis and hydrodesulfurization on metal single-crystal surfaces

    International Nuclear Information System (INIS)

    Gellman, A.J.; Asscher, M.; Somorjai, G.A.

    1985-01-01

    The authors studied the ammonia synthesis reaction over Fe and Re single crystal surfaces and the hydrodesulfurization of thiophene over the Mo(100) single crystal surface. The studies have been performed using UHV surface science tools with the capability of exposing the surfaces to high pressure, high temperature reaction conditions. The ammonia synthesis reaction was shown to be extremely sensitive to surface structure on both Fe and Re, favoring surfaces with a rough or open topography. The HDS reaction on the Mo(100) surface has been shown to be similar to that on MoS/sub 2/ and appears to proceed via a reaction path that does not produce a strong Mo-S bond as an intermediate species

  20. Language in use intermediate : self-study workbook

    CERN Document Server

    Doff, Adrian

    1994-01-01

    Each of the four levels comprises about 80 hours of class work, with additional time for the self-study work. The Teacher's Book contains all the pages from the Classroom Book, with interleaved teaching notes including optional activities to cater for different abilities. There is a video to accompany the Beginner, Pre-intermediate and Intermediate levels. Each video contains eight stimulating and entertaining short programmes, as well as a booklet of photocopiable activities. Free test material is available in booklet and web format for Beginner and Pre-intermediate levels. Visit www.cambridge.org/elt/liu or contact your local Cambridge University Press representative.

  1. Analogues of amphibian alkaloids: total synthesis of (5R,8S,8aS-(--8-methyl-5-pentyloctahydroindolizine (8-epi-indolizidine 209B and [(1S,4R,9aS-(--4-pentyloctahydro-2H-quinolizin-1-yl]methanol

    Directory of Open Access Journals (Sweden)

    de Koning Charles B

    2008-01-01

    Full Text Available Abstract Background Prior work from these laboratories has centred on the development of enaminones as versatile intermediates for the synthesis of alkaloids and other nitrogen-containing heterocycles. In this paper we describe the enantioselective synthesis of indolizidine and quinolizidine analogues of bicyclic amphibian alkaloids via pyrrolidinylidene- and piperidinylidene-containing enaminones. Results Our previously reported synthesis of racemic 8-epi-indolizidine 209B has been extended to the laevorotatory enantiomer, (--9. Attempts to adapt the synthetic route in order to obtain quinolizidine analogues revealed that a key piperidinylidene-containing enaminone intermediate (+-28 was less tractable than its pyrrolidinylidene counterpart, thereby necessitating modifications that included timing changes and additional protection-deprotection steps. A successful synthesis of [(1S,4R,9aS-4-pentyloctahydro-2H-quinolizin-1-yl]methanol (--41 from the chiral amine tert-butyl (3R-3-{benzyl [(1R-1-phenylethyl]amino}octanoate (+-14 was achieved in 14 steps and an overall yield of 20.4%. Conclusion The methodology reported in this article was successfully applied to the enantioselective synthesis of the title compounds. It paves the way for the total synthesis of a range of cis-5,8-disubstituted indolizidines and cis-1,4-disubstituted quinolizidines, as well as the naturally occurring trans-disubstituted alkaloids.

  2. an intermediate moisture meat

    African Journals Online (AJOL)

    STORAGESEVER

    2008-07-04

    Jul 4, 2008 ... traditional SM muscle without compromising quality. ... technique is intermediate moisture food processing. ... Traditionally, most tsire suya producers use ..... quality of Chinese purebred and European X Chinese crossbred ...

  3. [Update on the biology of heme synthesis in erythroid cells].

    Science.gov (United States)

    Fujiwara, Tohru; Harigae, Hideo

    2015-02-01

    Heme is a prosthetic group of hemoproteins playing important roles in oxygen transport, detoxification, circadian rhythm, microRNA processing, regulation of transcription, and translation. The majority of heme (-85%) is synthesized in red blood cells mainly for hemoglobin production, whereas hepatocytes account for most of the rest, functioning primarily in the synthesis of cytochrome P450 enzymes and mitochondrial respiratory enzymes. Thus, failure of heme biosynthesis causes severe inherited or acquired disorders in humans, including porphyria and sideroblastic anemia. The heme biosynthetic pathway is composed of eight enzymes that work in either mitochondria or the cytoplasm, which have been extensively researched and frequently reviewed. On the other hand, the mechanisms governing transport and intracellular trafficking of heme intermediates, as well as their potential links to human diseases, are poorly understood. Herein, we focus on recent understanding of the heme biosynthetic pathway and on human disorders due to defective heme synthesis in erythroid cells, such as X-linked sideroblastic anemia and erythropoietic protoporphyria.

  4. The synthesis of deuterium labelled metabolites of warfarin and phenprocoumon

    International Nuclear Information System (INIS)

    Heimark, L.D.; Toon, S.; Low, L.K.; Swinney, D.C.; Trager, W.F.

    1986-01-01

    The synthesis of deuterium labelled 4'-,6-,7- and 8-hydroxy metabolites of warfarin and phenprocoumon is described. The pentadeuterio labelled 6-,7- and 8-hydroxyphenprocoumons were prepared via alkylation of the respective 6-, 7- and 8-methoxy-4-hydroxycoumarins with 1-(phenyl-d 5 )-1-bromopropane and subsequent cleavage of the methyl protecting group with boron tribromide. The synthesis of 1-(pentadeuteriophenyl)-1-bromopropane and the 6-, 7- and 8-methoxy-4-hydroxycoumarins are also presented. The pentadeuterio labelled 6-, 7- and 8-hydroxywarfarins were obtained by reaction of 4-(phenyl-d 5 )-3-buten-2-one with the respective 6-, 7- and 8-hydroxy-4-hydroxycoumarins in methanol followed by hydrolysis of the intermediate cyclic methyl ketals in aqueous acid. 4-Hydroxycoumarin-5,6,7,8-d 4 , prepared from phenyl-d 6 and tetradeuteriomalonic acid, was reacted with 1-(p-hydroxyphenyl)-1-propanol and 4-(p-hydroxyphenyl)-3-buten-2-one to yield labelled 4'-hydroxyphenprocoumon and 4'-hydroxywarfarin respectively. (author)

  5. Activation of aluminum as an effective reducing agent by pitting corrosion for wet-chemical synthesis.

    Science.gov (United States)

    Li, Wei; Cochell, Thomas; Manthiram, Arumugam

    2013-01-01

    Metallic aluminum (Al) is of interest as a reducing agent because of its low standard reduction potential. However, its surface is invariably covered with a dense aluminum oxide film, which prevents its effective use as a reducing agent in wet-chemical synthesis. Pitting corrosion, known as an undesired reaction destroying Al and is enhanced by anions such as F⁻, Cl⁻, and Br⁻ in aqueous solutions, is applied here for the first time to activate Al as a reducing agent for wet-chemical synthesis of a diverse array of metals and alloys. Specifically, we demonstrate the synthesis of highly dispersed palladium nanoparticles on carbon black with stabilizers and the intermetallic Cu₂Sb/C, which are promising candidates, respectively, for fuel cell catalysts and lithium-ion battery anodes. Atomic hydrogen, an intermediate during the pitting corrosion of Al in protonic solvents (e.g., water and ethylene glycol), is validated as the actual reducing agent.

  6. Ultra-low-energy ion-beam synthesis of nanometer-separated Si nanoparticles and Ag nanocrystals 2D layers

    Science.gov (United States)

    Carrada, M.; Haj Salem, A.; Pecassou, B.; Paillard, V.; Ben Assayag, G.

    2018-03-01

    2D networks of Si and Ag nanocrystals have been fabricated in the same SiO2 matrix by Ultra-Low-Energy Ion-Beam-Synthesis. Our synthesis scheme differs from a simple sequential ion implantation and its key point is the control of the matrix integrity through an appropriate intermediate thermal annealing. Si nanocrystal layer is synthesised first due to high thermal budget required for nucleation, while the second Ag nanocrystal plane is formed during a subsequent implantation due to the high diffusivity of Ag in silica. The aim of this work is to show how it is possible to overcome the limitation related to ion mixing and implantation damage to obtain double layers of Si-NCs and Ag-NCs with controlled characteristics. For this, we take advantage of annealing under slight oxidizing ambient to control the oxidation of Si-NCs and the Si excess in the matrix. The nanocrystal characteristics and in particular their position and size can be adjusted thanks to a compromise between the implantation energy, the implanted dose for both Si and Ag ions and the intermediate annealing conditions (atmosphere, temperature and duration).

  7. Synthesis of D-fructose-derived spirocyclic 2-substituted-2-oxazoline ribosides

    Directory of Open Access Journals (Sweden)

    Madhuri Vangala

    2015-11-01

    Full Text Available The TMSOTf-mediated synthesis of β-configured spirocyclic 2-substituted-2-oxazoline ribosides was achieved using a “Ritter-like” reaction in toluene through nucleophilic addition of electron-rich nitriles to the oxacarbenium ion intermediate of 1,2;3,4-di-O-isopropylidene-β-D-psicofuranose derivatives with concomitant intramolecular trapping of the C2 hydroxymethyl group on the electrophilic nitrilium carbon. These carbohydrate-derived spirooxazolines are stable and were obtained in good yield with high stereoselectivity due to the conformational rigidity imparted by the 3,4-isopropylidene group.

  8. Low Temperature Synthesis and Properties of Gadolinium-Doped Cerium Oxide Nanoparticles

    DEFF Research Database (Denmark)

    Machado, M. F. S.; Moraes, L. P. R.; Monteiro, N. K.

    2017-01-01

    Gadolinium-doped cerium oxide (GDC) is an attractive ceramic material for solid oxide fuel cells (SOFCs) both as the electrolyte and in composite electrodes operating at low and intermediate temperatures. GDC exhibits high oxygen ion conductivity at a wide range of temperatures and displays a high...... resistance to carbon deposition when hydrocarbons are used as fuels. However, an inconvenience of ceria-based oxides is the high sintering temperature needed to obtain a fully dense ceramic body. In this study, a green chemistry route for the synthesis of 10 mol% GDC nanoparticles is proposed. The aqueous...

  9. Amide Synthesis from Alcohols and Amines by the Extrusion of Dihydrogen

    DEFF Research Database (Denmark)

    Nordstrøm, Lars Ulrik Rubæk; Vogt, Henning; Madsen, R.

    2008-01-01

    An environmentally friendly method for synthesis of amides is presented where a simple ruthenium catalyst mediates the direct coupling between an alcohol and an amine with the liberation of two molecules of dihydrogen. The active catalyst is generated in situ from an easily available ruthenium...... complex, an N-heterocyclic carbene and a phosphine. The reaction allows primary alcohols to be coupled with primary alkyamines to afford the corresponding secondary amides in good yields. The amide formation presumably proceeds through a catalytic cycle where the intermediate aldehyde and hemiaminal...

  10. Taming Radical Pairs in Nanocrystalline Ketones: Photochemical Syn-thesis of Compounds with Vicinal Stereogenic All-Carbon Quaternary Centers.

    Science.gov (United States)

    Dotson, Jordan J; Perez-Estrada, Salvador; Garcia-Garibay, Miguel A

    2018-05-29

    Here we describe the use of crystalline ketones to control the fate of the radical pair intermediates generated in the Norrish type I photodecarbonylation reaction to render it a powerful tool in the challenging synthesis of sterically congested carbon-carbon bonds. This methodology makes the synthetically more accessible hexasusbtituted ketones as ideal synthons for the construction of adjacent, all-carbon substituted, stereogenic quaternary stereocenters. We describe here the structural and thermochemical parameters required of the starting ketone in order to react in the solid state. Finally, the scope and scalability of the reaction and its application in the total synthesis of two natural products is described.

  11. Taxation of Financial Intermediation Activities in Hong Kong

    OpenAIRE

    Jack M. Mintz; Stephen R. Richardson

    2001-01-01

    This paper discusses issues related to the taxation of financial intermediation in Hong Kong in the context of Hong Kong's position as a major regional financial centre. It first provides some background analysis as to the definition of financial intermediation and identification of the providers of financial services. This is then followed by a discussion of the principles of taxation applicable to financial intermediation, including a comparison of income taxes to consumption taxes. Some sp...

  12. One-pot, two-step synthesis of imidazo[1,2-a]benzimidazoles via a multicomponent [4 + 1] cycloaddition reaction.

    Science.gov (United States)

    Hsiao, Ya-Shan; Narhe, Bharat D; Chang, Ying-Sheng; Sun, Chung-Ming

    2013-10-14

    A one-pot, two-step synthesis of imidazo[1,2-a]benzimidazoles has been achieved by a three-component reaction of 2-aminobenzimidazoles with an aromatic aldehyde and an isocyanide. The reaction involving condensation of 2-aminobenzimidazole with an aldehyde is run under microwave activation to generate an imine intermediate under basic conditions which then undergoes [4 + 1] cycloaddition with an isocyanide.

  13. Copper-Catalyzed Sulfonyl Azide-Alkyne Cycloaddition Reactions: Simultaneous Generation and Trapping of Copper-Triazoles and -Ketenimines for the Synthesis of Triazolopyrimidines.

    Science.gov (United States)

    Nallagangula, Madhu; Namitharan, Kayambu

    2017-07-07

    First simultaneous generation and utilization of both copper-triazole and -ketenimine intermediates in copper-catalyzed sulfonyl azide-alkyne cycloaddition reactions is achieved for the one-pot synthesis of triazolopyrimidines via a novel copper-catalyzed multicomponent cascade of sulfonyl azides, alkynes, and azirines. Significantly, the reaction proceeds under very mild conditions in good yields.

  14. Synthesis of racemic [methyl-d3]-labeled cis- and trans-3'-hydroxycotinine

    International Nuclear Information System (INIS)

    Ravard, A.; Crooks, P.A.

    1994-01-01

    A method is described for the synthesis of the racemic [methyl-d 3 ] forms of the nicotine metabolites cis-3'-hydroxycotinine and trans-3'-hydroxycotinine. The key intermediate was [methyl-d 3 ]-N-methylhydroxylamine, obtained from a selective hydrogenation of d 3 -nitro-methane. This intermediate was converted to [methyl-d 3 ]-α-3-pyridyl-N-methylnitrone, which was condensed with methyl acrylate to give a mixture of isomeric isoxazolidines. The hydrogenolysis of this mixture afforded a 70:30 mixture of [methyl-d 3 ] cis- and trans-3'-hydroxycotinine, from which the pure cis-isomer could be isolated by recrystallization from acetone. [Methyl-d 3 ]-trans-3'-hydroxycotinine could be prepared in high yield from the cis-isomer via chiral inversion utilizing a Mitsunobu reaction, or by chromatographic separation from a mixture of the cis- and trans-3'-benzoyloxycotinine, followed by O-debenzoylation in methanolic NaOH. (author)

  15. A dearth of intermediate melts at subduction zone volcanoes and the petrogenesis of arc andesites.

    Science.gov (United States)

    Reubi, Olivier; Blundy, Jon

    2009-10-29

    Andesites represent a large proportion of the magmas erupted at continental arc volcanoes and are regarded as a major component in the formation of continental crust. Andesite petrogenesis is therefore fundamental in terms of both volcanic hazard and differentiation of the Earth. Andesites typically contain a significant proportion of crystals showing disequilibrium petrographic characteristics indicative of mixing or mingling between silicic and mafic magmas, which fuels a long-standing debate regarding the significance of these processes in andesite petrogenesis and ultimately questions the abundance of true liquids with andesitic composition. Central to this debate is the distinction between liquids (or melts) and magmas, mixtures of liquids with crystals, which may or may not be co-genetic. With this distinction comes the realization that bulk-rock chemical analyses of petrologically complex andesites can lead to a blurred picture of the fundamental processes behind arc magmatism. Here we present an alternative view of andesite petrogenesis, based on a review of quenched glassy melt inclusions trapped in phenocrysts, whole-rock chemistry, and high-pressure and high-temperature experiments. We argue that true liquids of intermediate composition (59 to 66 wt% SiO(2)) are far less common in the sub-volcanic reservoirs of arc volcanoes than is suggested by the abundance of erupted magma within this compositional range. Effective mingling within upper crustal magmatic reservoirs obscures a compositional bimodality of melts ascending from the lower crust, and masks the fundamental role of silicic melts (>/=66 wt% SiO(2)) beneath intermediate arc volcanoes. This alternative view resolves several puzzling aspects of arc volcanism and provides important clues to the integration of plutonic and volcanic records.

  16. Intermediate-energy nuclear chemistry workshop

    International Nuclear Information System (INIS)

    Butler, G.W.; Giesler, G.C.; Liu, L.C.; Dropesky, B.J.; Knight, J.D.; Lucero, F.; Orth, C.J.

    1981-05-01

    This report contains the proceedings of the LAMPF Intermediate-Energy Nuclear Chemistry Workshop held in Los Alamos, New Mexico, June 23-27, 1980. The first two days of the Workshop were devoted to invited review talks highlighting current experimental and theoretical research activities in intermediate-energy nuclear chemistry and physics. Working panels representing major topic areas carried out indepth appraisals of present research and formulated recommendations for future research directions. The major topic areas were Pion-Nucleus Reactions, Nucleon-Nucleus Reactions and Nuclei Far from Stability, Mesonic Atoms, Exotic Interactions, New Theoretical Approaches, and New Experimental Techniques and New Nuclear Chemistry Facilities

  17. Intermediate-energy nuclear chemistry workshop

    Energy Technology Data Exchange (ETDEWEB)

    Butler, G.W.; Giesler, G.C.; Liu, L.C.; Dropesky, B.J.; Knight, J.D.; Lucero, F.; Orth, C.J.

    1981-05-01

    This report contains the proceedings of the LAMPF Intermediate-Energy Nuclear Chemistry Workshop held in Los Alamos, New Mexico, June 23-27, 1980. The first two days of the Workshop were devoted to invited review talks highlighting current experimental and theoretical research activities in intermediate-energy nuclear chemistry and physics. Working panels representing major topic areas carried out indepth appraisals of present research and formulated recommendations for future research directions. The major topic areas were Pion-Nucleus Reactions, Nucleon-Nucleus Reactions and Nuclei Far from Stability, Mesonic Atoms, Exotic Interactions, New Theoretical Approaches, and New Experimental Techniques and New Nuclear Chemistry Facilities.

  18. The ARES High-level Intermediate Representation

    Energy Technology Data Exchange (ETDEWEB)

    Moss, Nicholas David [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-03-03

    The LLVM intermediate representation (IR) lacks semantic constructs for depicting common high-performance operations such as parallel and concurrent execution, communication and synchronization. Currently, representing such semantics in LLVM requires either extending the intermediate form (a signi cant undertaking) or the use of ad hoc indirect means such as encoding them as intrinsics and/or the use of metadata constructs. In this paper we discuss a work in progress to explore the design and implementation of a new compilation stage and associated high-level intermediate form that is placed between the abstract syntax tree and when it is lowered to LLVM's IR. This highlevel representation is a superset of LLVM IR and supports the direct representation of these common parallel computing constructs along with the infrastructure for supporting analysis and transformation passes on this representation.

  19. Synthesis of new polyphosphonic acids, uranium extracting agents in a phosphoric medium

    International Nuclear Information System (INIS)

    Pensec, T.

    1981-04-01

    Synthesis of organic phosphorus compounds for liquid-liquid extraction of traces of uranium in concentrated phosphoric acid is studied in view of industrial applications. Diphosphonic acids and monoesters and also triphosphonic acids and related compounds are synthetized. Extraction tests show a better efficiency than OPPA [fr

  20. Gasoline Engine Mechanics. Performance Objectives. Intermediate Course.

    Science.gov (United States)

    Jones, Marion

    Several intermediate performance objectives and corresponding criterion measures are listed for each of six terminal objectives presented in this curriculum guide for an intermediate gasoline engine mechanics course at the secondary level. (For the beginning course guide see CE 010 947.) The materials were developed for a two-semester (2 hour…

  1. Synthesis of racemic and chiral albicanol, albicanyl acetate and cyclozonarone: cytotoxic activity of ent-cyclozonarone

    International Nuclear Information System (INIS)

    Delgado, Virginia; Armstrong, Veronica; Cortes, Manuel; Barrero, Alejandro F.

    2008-01-01

    The total synthesis of racemic cyclozonarone ((±)-3) was achieved from E,E-farnesol (4) in an eight-step sequence in 6.6% overall yield. Albicanol ((±)-1) and its acetate ((±)-2) are intermediates. A similar sequence starting from natural (-)-drimenol (5) gave (+)-albicanol (1) and (+)-cyclozonarone (3) (42% and 11% yield, respectively). The cytotoxic activity of (+)-cyclozonarone was assayed and showed some selectivity towards MS-1 (mice endothelial cells). (author)

  2. Mapping student thinking in chemical synthesis

    Science.gov (United States)

    Weinrich, Melissa

    In order to support the development of learning progressions about central ideas and practices in different disciplines, we need detailed analyses of the implicit assumptions and reasoning strategies that guide students' thinking at different educational levels. In the particular case of chemistry, understanding how new chemical substances are produced (chemical synthesis) is of critical importance. Thus, we have used a qualitative research approach based on individual interviews with first semester general chemistry students (n = 16), second semester organic chemistry students (n = 15), advanced undergraduates (n = 9), first year graduate students (n = 15), and PhD candidates (n = 16) to better characterize diverse students' underlying cognitive elements (conceptual modes and modes of reasoning) when thinking about chemical synthesis. Our results reveal a great variability in the cognitive resources and strategies used by students with different levels of training in the discipline to make decisions, particularly at intermediate levels of expertise. The specific nature of the task had a strong influence on the conceptual sophistication and mode of reasoning that students exhibited. Nevertheless, our data analysis has allowed us to identify common modes of reasoning and assumptions that seem to guide students' thinking at different educational levels. Our results should facilitate the development of learning progressions that help improve chemistry instruction, curriculum, and assessment.

  3. Effects of Whey, Caseinate, or Milk Protein Ingestion on Muscle Protein Synthesis after Exercise.

    Science.gov (United States)

    Kanda, Atsushi; Nakayama, Kyosuke; Sanbongi, Chiaki; Nagata, Masashi; Ikegami, Shuji; Itoh, Hiroyuki

    2016-06-03

    Whey protein (WP) is characterized as a "fast" protein and caseinate (CA) as a "slow" protein according to their digestion and absorption rates. We hypothesized that co-ingestion of milk proteins (WP and CA) may be effective for prolonging the muscle protein synthesis response compared to either protein alone. We therefore compared the effect of ingesting milk protein (MP) to either WP or CA alone on muscle protein synthesis after exercise in rats. We also compared the effects of these milk-derived proteins to a control, soy protein (SP). Male Sprague-Dawley rats swam for two hours. Immediately after exercise, one of the following four solutions was administered: WP, CA, MP, or SP. Individual rats were euthanized at designated postprandial time points and triceps muscle samples collected for measurement of the protein fractional synthesis rate (FSR). FSR tended to increase in all groups post-ingestion, although the initial peaks of FSR occurred at different times (WP, peak time = 60 min, FSR = 7.76%/day; MP, peak time = 90 min, FSR = 8.34%/day; CA, peak time = 120 min, FSR = 7.85%/day). Milk-derived proteins caused significantly greater increases (p protein synthesis to occur at different times (WP, fast; MP, intermediate; CA, slow) and the dairy proteins have a superior effect on muscle protein synthesis after exercise compared with SP.

  4. An Efficient Synthesis of Substituted Furans by Cupric Halide-Mediated Intramolecular Halocyclization of 2-(1-Alkynyl)-2-alken-1-ones

    International Nuclear Information System (INIS)

    Fu, Weijun; Guo, Wenbo; Zhu, Mei; Xu, Chen; Xu, Fengjuan

    2013-01-01

    An efficient synthesis of 3-halofurans by the intramolecular cyclization of 2-(1-alkynyl)-2-alken-1-ones with cupric halide has been developed. A broad range of 3-chloro- and 3-bromofuran derivatives could be obtained in the present method in moderate to good yields. The 3-halofuran derivatives are potential synthetic intermediates for amplification of molecular complexity

  5. Synthesis and assessment methods for an edge-alignment-free hybrid image

    Science.gov (United States)

    Sripian, Peeraya; Yamaguchi, Yasushi

    2017-07-01

    A hybrid image allows multiple image interpretations to be modulated by the viewing distance. It can be constructed on the basis of the multiscale perceptual mechanisms of the human visual system by combining the low and high spatial frequencies of two different images. The hybrid image was introduced as an experimental tool for visual recognition study in terms of spatial frequency perception. To produce a compelling hybrid image, the original hybrid image synthesis method could only use similar shapes of source images that were aligned in the edges. If any two different images can be hybrid, it would be beneficial as a new experimental tool. In addition, there is no measure for the actual perception of spatial frequency, whether a single spatial frequency or both spatial frequencies are perceived from the hybrid stimulus. This paper describes two methods for synthesizing a hybrid image from dissimilar shape images or unaligned images; this hybrid image is known as an "edge-alignment-free hybrid image." A noise-inserted method can be done by intentionally inserting and enhancing noises into the high-frequency image. With this method, the low-frequency blobs are covered with high-frequency noises when viewed up close. A color-inserted method uses complementary color gratings in the background of the high-frequency image to emphasize the high-frequency image when viewed up close, whereas the gratings disappear when viewed from far away. To ascertain that our approach successfully separates the spatial frequency at each viewing distance, we measured this property using our proposed assessment method. Our proposed method allows the experimenter to quantify the probability of perceiving both spatial frequencies and a single spatial frequency in a hybrid image. The experimental results confirmed that our proposed synthesis methods successfully hid the low-frequency image and emphasized the high-frequency image at a close viewing distance. At the same time, the

  6. Highly efficient synthetic method onpyroacm resin using the boc SPPS protocol for C-terminal cysteine peptide synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Juvekar, Vinayak; Kim, Kang Tae; Gong, Young Dae [Innovative Drug Library Research Center, Dept. of Chemistry, College of Science, Dongguk University, Seoul (Korea, Republic of)

    2017-01-15

    A very effective process on Pyroacm resin was developed for solid-phase peptide synthesis (SPPS) of C-terminal cysteine and cysteine ester peptides. The process uses cysteine side chain anchoring to the Pyroacm resin and the Boc protocol for SPPS. The Pyroacm resin showed remarkable stability under standard trifluoromethanesulfonic acid (TFMSA) cleavage condition. TFMSA cleavage of protecting groups generates a peptide-linked resin, which can be subjected to peptide modification reactions. Finally, the peptide can be cleaved from the resin using methoxycarbonylsulfenyl chloride. The utility of this protocol was demonstrated by its applications to the synthesis of model peptides, key intermediates in the preparation of natural products riparin 1.2 and a-factor.

  7. Synthesis of anatase TiO2 nanoparticles with beta-cyclodextrin as a supramolecular shell.

    Science.gov (United States)

    Li, Landong; Sun, Xiaohong; Yang, Yali; Guan, Naijia; Zhang, Fuxiang

    2006-11-20

    We report a novel, green hydrothermal-synthesis route to well-dispersed anatase TiO2 nanoparticles with particle sizes of 9-16 nm in the presence of beta-CD (beta-cyclodextrin). During the synthesis process, the CD-containing synthesis mixture assembled in both longitudinal and latitudinal directions. Driven by the interaction between molecules, the beta-CDs assembled in the longitudinal direction to form long-chain compounds, whereas in the latitudinal direction, they tended to form regular aggregates through coordination with the Ti species from the hydrolysis of tetrabutyl titanate. In view of the effect of the coordination and the steric hindrance of beta-CDs as a supramolecular shell, homogeneous nuclei and slow growth of TiO2 crystals during the synthesis process was observed, which was responsible for the formation of uniform TiO2 nanoparticles. The low beta-CD dosage and the high product yield (>90%) demonstrated well the potential of this synthesis route in the large-scale industrial production of anatase nanoparticles.

  8. Mapping Intermediality in Performance

    NARCIS (Netherlands)

    2010-01-01

    Mapping Intermediality in Performance benadert het vraagstuk van intermedialiteit met betrekking tot performance (vooral theater) vanuit vijf verschillende invalshoeken: performativiteit en lichaam; tijd en ruimte; digitale cultuur en posthumanisme; netwerken; pedagogiek en praxis. In deze boeiende

  9. Synthesis of an Imidazolidinone Organocatalyst and Its Application in a Diels-Alder Cycloaddition: A Multistep Experiment for the Organic Teaching Laboratory

    Science.gov (United States)

    Murphy, John J.; Driver, Ross B.; Walsh, Ria; Stephens, John C.

    2016-01-01

    The development of novel, high-yielding, and selective methodologies for the asymmetric synthesis of stereocenters is at the forefront of modern synthetic chemistry research. Organocatalysis can now be viewed as a viable alternative to the use of the sometimes toxic transition-metal catalysts. In this experiment, the simple synthesis of an achiral…

  10. Electrochemical performance of Nd1.8Ce0.2CuO4+δ:Ce0.9Gd0.1O2 composite cathode for intermediate temperature solid oxide fuel cells

    International Nuclear Information System (INIS)

    Khandale, A.P.; Bhoga, S.S.

    2012-01-01

    Intermediate temperature solid oxide fuel cells (IT-SOFCs) are viewed as a promising power generation systems with high efficiency and low pollution. Recently, mixed ionic-electronic conductors (MIECs), with K 2 NiF 4 - type structure, attracted much attention as cathode for IT-SOFC

  11. Synthesis of acrylates and methacrylates from coal-derived syngas

    Energy Technology Data Exchange (ETDEWEB)

    Spivey, J.J.; Gogate, M.R.; Jang, B.W.L. [Bechtel, San Francisco, CA (United States)] [and others

    1995-12-31

    Acrylates and methacrylates are among the most widely used chemical intermediates in the world. One of the key chemicals of this type is methyl methacrylate. Of the 4 billion pounds produced each year, roughly 85% is made using the acetone-cyanohydrin process, which requires handling of large quantities of hydrogen cyanide and produces ammonium sulfate wastes that pose an environmental disposal challenge. The U.S. Department of Energy and Eastman Chemical Company are sharing the cost of research to develop an alternative process for the synthesis of methyl methacrylate from syngas. Research Triangle Institute is focusing on the synthesis and testing of active catalysts for the condensation reactions, and Bechtel is analyzing the costs to determine the competitiveness of several process alternatives. Results thus far show that the catalysts for the condensation of formaldehyde and the propionate are key to selectively producing the desired product, methacrylic acid, with a high yield. These condensation catalysts have both acid and base functions and the strength and distribution of these acid-base sites controls the product selectivity and yield.

  12. Synthesis of deuterium labelled metabolites of warfarin and phenprocoumon

    Energy Technology Data Exchange (ETDEWEB)

    Heimark, L.D.; Toon, S.; Low, L.K.; Swinney, D.C.; Trager, W.F.

    1986-02-01

    The synthesis of deuterium labelled 4'-,6-,7- and 8-hydroxy metabolites of warfarin and phenprocoumon is described. The pentadeuterio labelled 6-,7- and 8-hydroxyphenprocoumons were prepared via alkylation of the respective 6-, 7- and 8-methoxy-4-hydroxycoumarins with 1-(phenyl-d/sub 5/)-1-bromopropane and subsequent cleavage of the methyl protecting group with boron tribromide. The synthesis of 1-(pentadeuteriophenyl)-1-bromopropane and the 6-, 7-and 8-methoxy-4-hydroxycoumarins are also presented. The pentadeuterio labelled 6-, 7- and 8-hydroxywarfarins were obtained by reaction of 4-(phenyl-d/sub 5/)-3-buten-2-one with the respective 6-, 7- and 8-hydroxy-4-hydroxycoumarins in methanol followed by hydrolysis of the intermediate cyclic methyl ketals in aqueous acid. 4-Hydroxycoumarin-5,6,7,8-d/sub 4/, prepared from phenyl-d/sub 6/ and tetradeuteriomalonic acid, was reacted with 1-(p-hydroxyphenyl)-1-propanol and 4-(p-hydroxyphenyl)-3-buten-2-one to yield labelled 4'-hydroxyphenprocoumon and 4'-hydroxywarfarin respectively.

  13. Knorr-Rabe partial reduction of pyrroles: Application to the synthesis of indolizidine alkaloids

    Directory of Open Access Journals (Sweden)

    Ryan John H

    2008-01-01

    Full Text Available Abstract Background The Birch reduction of electron rich pyrroles does not occur readily. However, dissolving metal reduction with zinc under acidic conditions gives 3-pyrrolines (2,5-dihydropyrroles in reasonable yield. This dissolving metal reduction was first reported by Knorr and Rabe in 1901 but since then has only been reported for the reduction of electron rich pyrroles. Results The partial reduction of bicyclic α-ketopyrrole derivatives has been performed under dissolving metal conditions with zinc and hydrochloric acid to give excellent yields of hexahydroindolizidines. This reduction method has been utilised for the diastereoselective synthesis of 5-alkylindolizidines and the stereoselectivity obtained is opposite to that of catalytic hydrogenation. Conclusion An efficient stereoselective synthesis of indolizidine alkaloids has been developed from α-ketopyrrole intermediates using a modified version of Knorr and Rabe's pyrrole reduction.

  14. Tin-Assisted Synthesis of ɛ -Ga2O3 by Molecular Beam Epitaxy

    Science.gov (United States)

    Kracht, M.; Karg, A.; Schörmann, J.; Weinhold, M.; Zink, D.; Michel, F.; Rohnke, M.; Schowalter, M.; Gerken, B.; Rosenauer, A.; Klar, P. J.; Janek, J.; Eickhoff, M.

    2017-11-01

    The synthesis of ɛ -Ga2O3 and β -Ga2O3 by plasma-assisted molecular beam epitaxy on (001 )Al2O3 substrates is studied. The growth window of β -Ga2O3 in the Ga-rich regime, usually limited by the formation of volatile gallium suboxide, is expanded due to the presence of tin during the growth process, which stabilizes the formation of gallium oxides. X-ray diffraction, transmission electron microscopy, time-of-flight secondary-ion mass spectrometry, Raman spectroscopy, and atomic force microscopy are used to analyze the influence of tin on the layer formation. We demonstrate that it allows the synthesis of phase-pure ɛ -Ga2O3 . A growth model based on the oxidation of gallium suboxide by reduction of an intermediate sacrificial tin oxide is suggested.

  15. Two-Color VR CCD Photometry of the Intermediate Polar 1RXS J062518.2+733433

    Directory of Open Access Journals (Sweden)

    Yonggi Kim

    2005-09-01

    Full Text Available Results of 7 nights of CCD VR photometry of the intermediate polar 1RXS J062518.2 +733433 obtained at the Korean 1.8m telescope are reported. The corrected ephemeris for the orbital minimum is BJD (Orb.min = 2453023.6159 (42+0.1966431 (33 (E- 1735. The corrected ephemeris for the spin maximum is BJD (spin max = 2452893 .78477 (10+0.01374116815 (17 (E-15382 (cycle numbering corresponds to that of Staude et al.~2003. The variations of the shape of the individual spin variations are highly correlated in V and R. The phase of the spin maximum is found to be dependent on the orbital phase. The corresponding semi-amplitude of sinusoidal variations of phase is 0.11±0.03. This new phenomenon is explained by the changing viewing conditions of the accreting magnetic white dwarf, and should be checked in further observations this star and for other intermediate polars. To avoid influence of this effect on the analysis of the long-term spin period variations, the runs of at least one orbital period are recommended. Results of time series analysis are presented in tables.

  16. Synthesis and characterization of novel electrolyte materials for intermediate temperature solid oxide fuel cells

    International Nuclear Information System (INIS)

    Chaubey, Nityanand; Chattopadhyaya, M.C.; Wani, B.N.; Bharadwaj, S.R.

    2008-01-01

    The high operating temperature of SOFCs using zirconia based electrolyte have several restrictions on materials used as interconnect and sealing and also requires use of expensive ceramics. Lowering the operating temperature of SOFCs to 600-800 deg C will enable to use cheaper materials and reduce the cost of fabrication while keeping the high power density. Lanthanide gallates are considered to be very promising solid electrolytes for intermediate temperature (600-800 deg C) solid oxide fuel cells (IT-SOFCs) due to their high ionic conductivity at lower temperatures. Phase purity of this material is a concern for the researchers for a long time. These materials are prepared at very high temperature (∼1400 deg C), since it is known that at around 1100 deg C, solubilities of Sr and Mg in LaGaO 3 were close to zero. Hence in the present work perovskite oxides of Ln 1-x Sr x Ga 1-y Mg y O 3-δ (Ln= Sm, Gd and x = 0.10, y=0.20) have been prepared by different methods i.e. solid state reaction, gel combustion and co-precipitation methods

  17. Probing the structure of ribosome assembly intermediates in vivo using DMS and hydroxyl radical footprinting.

    Science.gov (United States)

    Hulscher, Ryan M; Bohon, Jen; Rappé, Mollie C; Gupta, Sayan; D'Mello, Rhijuta; Sullivan, Michael; Ralston, Corie Y; Chance, Mark R; Woodson, Sarah A

    2016-07-01

    The assembly of the Escherichia coli ribosome has been widely studied and characterized in vitro. Despite this, ribosome biogenesis in living cells is only partly understood because assembly is coupled with transcription, modification and processing of the pre-ribosomal RNA. We present a method for footprinting and isolating pre-rRNA as it is synthesized in E. coli cells. Pre-rRNA synthesis is synchronized by starvation, followed by nutrient upshift. RNA synthesized during outgrowth is metabolically labeled to facilitate isolation of recent transcripts. Combining this technique with two in vivo RNA probing methods, hydroxyl radical and DMS footprinting, allows the structure of nascent RNA to be probed over time. Together, these can be used to determine changes in the structures of ribosome assembly intermediates as they fold in vivo. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. The Intermediate Neutrino Program

    CERN Document Server

    Adams, C.; Ankowski, A.M.; Asaadi, J.A.; Ashenfelter, J.; Axani, S.N.; Babu, K.; Backhouse, C.; Band, H.R.; Barbeau, P.S.; Barros, N.; Bernstein, A.; Betancourt, M.; Bishai, M.; Blucher, E.; Bouffard, J.; Bowden, N.; Brice, S.; Bryan, C.; Camilleri, L.; Cao, J.; Carlson, J.; Carr, R.E.; Chatterjee, A.; Chen, M.; Chen, S.; Chiu, M.; Church, E.D.; Collar, J.I.; Collin, G.; Conrad, J.M.; Convery, M.R.; Cooper, R.L.; Cowen, D.; Davoudiasl, H.; de Gouvea, A.; Dean, D.J.; Deichert, G.; Descamps, F.; DeYoung, T.; Diwan, M.V.; Djurcic, Z.; Dolinski, M.J.; Dolph, J.; Donnelly, B.; Dwyer, D.A.; Dytman, S.; Efremenko, Y.; Everett, L.L.; Fava, A.; Figueroa-Feliciano, E.; Fleming, B.; Friedland, A.; Fujikawa, B.K.; Gaisser, T.K.; Galeazzi, M.; Galehouse, D.C.; Galindo-Uribarri, A.; Garvey, G.T.; Gautam, S.; Gilje, K.E.; Gonzalez-Garcia, M.; Goodman, M.C.; Gordon, H.; Gramellini, E.; Green, M.P.; Guglielmi, A.; Hackenburg, R.W.; Hackenburg, A.; Halzen, F.; Han, K.; Hans, S.; Harris, D.; Heeger, K.M.; Herman, M.; Hill, R.; Holin, A.; Huber, P.; Jaffe, D.E.; Johnson, R.A.; Joshi, J.; Karagiorgi, G.; Kaufman, L.J.; Kayser, B.; Kettell, S.H.; Kirby, B.J.; Klein, J.R.; Kolomensky, Yu. G.; Kriske, R.M.; Lane, C.E.; Langford, T.J.; Lankford, A.; Lau, K.; Learned, J.G.; Ling, J.; Link, J.M.; Lissauer, D.; Littenberg, L.; Littlejohn, B.R.; Lockwitz, S.; Lokajicek, M.; Louis, W.C.; Luk, K.; Lykken, J.; Marciano, W.J.; Maricic, J.; Markoff, D.M.; Martinez Caicedo, D.A.; Mauger, C.; Mavrokoridis, K.; McCluskey, E.; McKeen, D.; McKeown, R.; Mills, G.; Mocioiu, I.; Monreal, B.; Mooney, M.R.; Morfin, J.G.; Mumm, P.; Napolitano, J.; Neilson, R.; Nelson, J.K.; Nessi, M.; Norcini, D.; Nova, F.; Nygren, D.R.; Orebi Gann, G.D.; Palamara, O.; Parsa, Z.; Patterson, R.; Paul, P.; Pocar, A.; Qian, X.; Raaf, J.L.; Rameika, R.; Ranucci, G.; Ray, H.; Reyna, D.; Rich, G.C.; Rodrigues, P.; Romero, E.Romero; Rosero, R.; Rountree, S.D.; Rybolt, B.; Sanchez, M.C.; Santucci, G.; Schmitz, D.; Scholberg, K.; Seckel, D.; Shaevitz, M.; Shrock, R.; Smy, M.B.; Soderberg, M.; Sonzogni, A.; Sousa, A.B.; Spitz, J.; St. John, J.M.; Stewart, J.; Strait, J.B.; Sullivan, G.; Svoboda, R.; Szelc, A.M.; Tayloe, R.; Thomson, M.A.; Toups, M.; Vacheret, A.; Vagins, M.; Van de Water, R.G.; Vogelaar, R.B.; Weber, M.; Weng, W.; Wetstein, M.; White, C.; White, B.R.; Whitehead, L.; Whittington, D.W.; Wilking, M.J.; Wilson, R.J.; Wilson, P.; Winklehner, D.; Winn, D.R.; Worcester, E.; Yang, L.; Yeh, M.; Yokley, Z.W.; Yoo, J.; Yu, B.; Yu, J.; Zhang, C.

    2015-01-01

    The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summ...

  19. Regioselective Synthesis of 3-Amino-4-arylisoxazol-5(4H)-ones

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Dong Won; Lee, Ihl Young Choi; Lim, Hee Jong [Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of)

    2010-11-15

    We have demonstrated a new and efficient method for the synthesis of 3-substituted aminoisoxazoles from readily available thiocarbamoyl esters. Mercury (II) chloride appeared to be a Lewis acid of choice among the metals tested in this cyclodesulfurization reaction. Application of this method for the synthesis of substituted aminopyrazoles is now under investigation in our laboratory. 3-Aminoisoxazol-5(4H)-one is an important building block of many biologically active compounds including antimicrobial and antioxidant, K channel opener, and kinase inhibitors. Besides, it could be transformed to fused heterocyclic compounds such as indoles, imidazopyridines, and isoxazolopyrimidines. Condensation reaction of α-cyanoacetate with hydroxylamine was a well known method to access either 3-aminoisoxazol-5(4H)-one or isomeric 5-aminoisoxazol-3(4H)-one depending upon condition. For instance, reaction under the neutral condition provided 3-aminoisoxazolone isomer via acetamidoxime intermediate, whereas 5-aminoisoxazolone isomer was obtained under the alkaline condition.

  20. Properties of ceria doped with gadolinia via microwave-assisted hydrothermal synthesis

    International Nuclear Information System (INIS)

    Carregosa, J.D.C.; Oliveira, R.M.P.B.; Macedo, D.A.; Nascimento, R.M.

    2016-01-01

    The solid solution of CeO_2 doped with Gd"3"+ (CGO) is a promising candidate for electrolyte in Solid Oxide Full Cells (SOFCs) operating in intermediate and low temperatures. The reduction of the working temperature of these energy conversion devices is the great technological challenge to its marketing. In this work, nanocrystalline powders of Ce_1_-_xGd_xO_2_-_x_/_2 with x=0, x=0.1 e x=0.2 were obtained via microwave-hydrothermal synthesis at low temperature and times of synthesis (10 and 20 min at 120° C). The powders were analyzed by TG-DTA, DRX and dilatometry. The results showed characteristic peaks of the cubic fluorite-type structure, referring to the cerium oxide (CeO_2), without the presence of secondary peaks. It was also observed that the samples processed at levels of 10 and 20 minutes showed distinct behaviors in contrast to the concentrations of Gd"3"+. (author)

  1. Regioselective Synthesis of 3-Amino-4-arylisoxazol-5(4H)-ones

    International Nuclear Information System (INIS)

    Shin, Dong Won; Lee, Ihl Young Choi; Lim, Hee Jong

    2010-01-01

    We have demonstrated a new and efficient method for the synthesis of 3-substituted aminoisoxazoles from readily available thiocarbamoyl esters. Mercury (II) chloride appeared to be a Lewis acid of choice among the metals tested in this cyclodesulfurization reaction. Application of this method for the synthesis of substituted aminopyrazoles is now under investigation in our laboratory. 3-Aminoisoxazol-5(4H)-one is an important building block of many biologically active compounds including antimicrobial and antioxidant, K channel opener, and kinase inhibitors. Besides, it could be transformed to fused heterocyclic compounds such as indoles, imidazopyridines, and isoxazolopyrimidines. Condensation reaction of α-cyanoacetate with hydroxylamine was a well known method to access either 3-aminoisoxazol-5(4H)-one or isomeric 5-aminoisoxazol-3(4H)-one depending upon condition. For instance, reaction under the neutral condition provided 3-aminoisoxazolone isomer via acetamidoxime intermediate, whereas 5-aminoisoxazolone isomer was obtained under the alkaline condition

  2. Processing line for industrial radiation-thermal synthesis of doped lithium ferrite powders

    Science.gov (United States)

    Surzhikov, A. P.; Galtseva, O. V.; Vasendina, E. A.; Vlasov, V. A.; Nikolaev, E. V.

    2016-02-01

    The paper considers the issues of industrial production of doped lithium ferrite powders by radiation-thermal method. A technological scheme of the processing line is suggested. The radiation-thermal technological scheme enables production of powders with technical characteristics close to the required ones under relatively low temperature annealing conditions without intermediate mixing. The optimal conditions of the radiation-thermal synthesis are achieved isothermally under irradiation by the electron beam with energy of 2.5 MeV in the temperature range of 700-750 0C within- 120 min.

  3. New and convenient synthesis of 2-deoxy-D-ribose from 2,4-O-ethylidene-D-erythrose

    Energy Technology Data Exchange (ETDEWEB)

    Hauske, J.R.; Rapoport, H.

    1979-01-01

    A new synthesis is described of 2-deoxy-D-erythro-pentose (2-deoxy-D-ribose,2-deoxy-D-arabinose (1)), starting from D-glucose. The synthesis proceeds through direct olefination of 2,4-O-ethylidene-D-erythrose (2) by addition of the stabilized ylides generated from dimethylphosphorylmethyl phenyl sulfide (4) and the corresponding sulfoxide 5. These afford the key intermediates, thio-enol ether 7 and ..cap alpha..,..beta..-unsaturated sulfoxide 8, which when subjected to mercuric ion assisted hydrolysis gave high yields of 2-deoxy-D-ribose (1). This facile chain extension of 2 required its existance as a monomer, and conditions effective for obtaining the monomer have been developed. Detailed /sup 1/H and /sup 13/C NMR studies of these compounds are presented.

  4. Photo-Realistic Image Synthesis and Virtual Cinematography

    DEFF Research Database (Denmark)

    Livatino, Salvatore

    2005-01-01

    Realistic Virtual View Synthesis is a new field of research that has received increasing attention in recent years. It is strictly related to the grown popularity of virtual reality and the spread of its applications, among which virtual photography and cinematography. The use of computer generated...... characters, "virtual actors", in the motion picture production increases every day. While the most known computer graphics techniques have largely been adopted successfully in nowadays fictions, it still remains very challenging to implement virtual actors which would resemble, visually, human beings....... Interestingly, film directors have been looking at the recent progress achieved by the research community in the field of realistic visualization of virtual views, and they have successfully implemented state of the art research approaches in their productions. An innovative concept is then gaining consensus...

  5. A Convenient One-Pot Method for the Synthesis of N-Methoxy-N-methyl Amides from Carboxylic Acids

    International Nuclear Information System (INIS)

    Kim, Joong Gon; Jang, Doo Ok

    2010-01-01

    We have developed a mild and convenient method for one-pot synthesis of Weinreb amides from carboxylic acids. The process is general for the preparation of Weinreb amides from a variety of carboxylic acids. The reaction was also applicable to the preparation of α-amino Weinreb amides and proceeded without deprotection of the N-Fmoc protecting group or racemization of the stereogenic centers. N-Methoxy-N-methyl amides, or Weinreb amides, have been widely used as versatile synthetic intermediates in organic syntheses. These amides serve as excellent acylating agents for organolithium or organomagnesium reagents and as robust aldehyde group equivalents. The utility of Weinreb amides has been extended to the preparation of N-protected amino aldehydes, useful intermediates for many chemoselective transformations in peptide chemistry

  6. Intermediate Inflation or Late Time Acceleration?

    International Nuclear Information System (INIS)

    Sanyal, A.K.

    2008-01-01

    The expansion rate of intermediate inflation lies between the exponential and power law expansion but corresponding accelerated expansion does not start at the onset of cosmological evolution. Present study of intermediate inflation reveals that it admits scaling solution and has got a natural exit form it at a later epoch of cosmic evolution, leading to late time acceleration. The corresponding scalar field responsible for such feature is also found to behave as a tracker field for gravity with canonical kinetic term.

  7. On financial equilibrium with intermediation costs

    DEFF Research Database (Denmark)

    Markeprand, Tobias Ejnar

    2008-01-01

    This paper studies the set of competitive equilibria in financial economies with intermediation costs. We consider an arbitrary dividend structure, which includes options and equity with limited liabilities.We show a general existence result and upper-hemi continuity of the equilibrium correspond......This paper studies the set of competitive equilibria in financial economies with intermediation costs. We consider an arbitrary dividend structure, which includes options and equity with limited liabilities.We show a general existence result and upper-hemi continuity of the equilibrium...

  8. Intermediate product selection and blending in the food processing industry

    DEFF Research Database (Denmark)

    Kilic, Onur A.; Akkerman, Renzo; van Donk, Dirk Pieter

    2013-01-01

    This study addresses a capacitated intermediate product selection and blending problem typical for two-stage production systems in the food processing industry. The problem involves the selection of a set of intermediates and end-product recipes characterising how those selected intermediates...

  9. Corrosion behaviour of steel rebars embedded in a concrete designed for the construction of an intermediate-level radioactive waste disposal facility

    Directory of Open Access Journals (Sweden)

    Schulz F.M.

    2013-07-01

    Full Text Available The National Atomic Energy Commission of the Argentine Republic is developing a nuclear waste disposal management programme that contemplates the design and construction of a facility for the final disposal of intermediate-level radioactive wastes. The repository is based on the use of multiple, independent and redundant barriers. The major components are made in reinforced concrete so, the durability of these structures is an important aspect for the facility integrity. This work presents an investigation performed on an instrumented reinforced concrete prototype specifically designed for this purpose, to study the behaviour of an intermediate level radioactive waste disposal facility from the rebar corrosion point of view. The information obtained will be used for the final design of the facility in order to guarantee a service life more or equal than the foreseen durability for this type of facilities.

  10. Asymmetric synthesis of allylic sulfonic acids: enantio- and regioselective iridium-catalyzed allylations of Na2SO3.

    Science.gov (United States)

    Liu, Wei; Zhao, Xiao-ming; Zhang, Hong-bo; Zhang, Liang; Zhao, Ming-zhu

    2014-12-15

    An enantioselective allylation reaction of allylic carbonates with sodium sulfite (Na2 SO3 ) catalyzed by Ir complex was accomplished, providing allylic sulfonic acids in good to excellent yields with a high level of enantio- and regioselectivities. (R)-2-Phenyl-2-sulfoacetic acid, a key intermediate for the synthesis of Cefsulodin and Sulbenicillin, was synthesized as well. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Applications of Continuous-Flow Photochemistry in Organic Synthesis, Material Science, and Water Treatment.

    Science.gov (United States)

    Cambié, Dario; Bottecchia, Cecilia; Straathof, Natan J W; Hessel, Volker; Noël, Timothy

    2016-09-14

    Continuous-flow photochemistry in microreactors receives a lot of attention from researchers in academia and industry as this technology provides reduced reaction times, higher selectivities, straightforward scalability, and the possibility to safely use hazardous intermediates and gaseous reactants. In this review, an up-to-date overview is given of photochemical transformations in continuous-flow reactors, including applications in organic synthesis, material science, and water treatment. In addition, the advantages of continuous-flow photochemistry are pointed out and a thorough comparison with batch processing is presented.

  12. The Role of Ontologies in Schema-based Program Synthesis

    Science.gov (United States)

    Bures, Tomas; Denney, Ewen; Fischer, Bernd; Nistor, Eugen C.

    2004-01-01

    Program synthesis is the process of automatically deriving executable code from (non-executable) high-level specifications. It is more flexible and powerful than conventional code generation techniques that simply translate algorithmic specifications into lower-level code or only create code skeletons from structural specifications (such as UML class diagrams). Key to building a successful synthesis system is specializing to an appropriate application domain. The AUTOBAYES and AUTOFILTER systems, under development at NASA Ames, operate in the two domains of data analysis and state estimation, respectively. The central concept of both systems is the schema, a representation of reusable computational knowledge. This can take various forms, including high-level algorithm templates, code optimizations, datatype refinements, or architectural information. A schema also contains applicability conditions that are used to determine when it can be applied safely. These conditions can refer to the initial specification, to intermediate results, or to elements of the partially-instantiated code. Schema-based synthesis uses AI technology to recursively apply schemas to gradually refine a specification into executable code. This process proceeds in two main phases. A front-end gradually transforms the problem specification into a program represented in an abstract intermediate code. A backend then compiles this further down into a concrete target programming language of choice. A core engine applies schemas on the initial problem specification, then uses the output of those schemas as the input for other schemas, until the full implementation is generated. Since there might be different schemas that implement different solutions to the same problem this process can generate an entire solution tree. AUTOBAYES and AUTOFILTER have reached the level of maturity where they enable users to solve interesting application problems, e.g., the analysis of Hubble Space Telescope images

  13. Synthesis of optically pure deuterium-labelled nicotine, nornicotine and cotinine

    International Nuclear Information System (INIS)

    Jacob, P. III; Benowitz, N.L.; Shulgin, A.T.; California Univ., San Francisco

    1988-01-01

    We describe methods for the synthesis of enantiomerically pure (S)-nicotine-3',3'-d 2 , (S)-nornicotine-3',3-d 2 , and (S)-cotinine-4',4'-d 2 . The key intermediate was 5-bromomyosmine, which underwent base catalyzed exchange with deuterium oxide to give 5-bromomyosmine-3',3'- d 2 with >99% incorporation of label. This intermediate was reduced to (±)-5-bromo-nornicotine-3',3'-d 2 with sodium borohydride, resolved, and converted to (S)-nornicotine-3',3'-d(sub)2 by reductive debromination with hydrogen and a palladium catalyst. Reductive alkylation with formaldehyde and sodium borohydride provided (S)-nicotine-3',3'-d 2 , which was converted to (S)-cotinine-4',4'-d 2 by reaction with bromine followed by zinc reduction. The deuterium label is located at positions that are not attacked in the major routes of mammalian metabolism of these alkaloids. Syntheses of tetradeuterated analogs of nicotine and cotinine and a pentadeuterated analog of nicotine, in which additional deuterium atoms are incorporated in the methyl groups, are also reported. (author)

  14. The divergent synthesis of nitrogen heterocycles by rhodium(II)-catalyzed cycloadditions of 1-sulfonyl 1,2,3-triazoles with 1,3-dienes.

    Science.gov (United States)

    Shang, Hai; Wang, Yuanhao; Tian, Yu; Feng, Juan; Tang, Yefeng

    2014-05-26

    The first rhodium(II)-catalyzed aza-[4+3] cycloadditions of 1-sulfonyl 1,2,3-triazoles with 1,3-dienes have been developed, and enable the efficient synthesis of highly functionalized 2,5-dihydroazepines from readily available precursors. In some cases, the reaction pathway could divert to formal aza-[3+2] cycloadditions, thus leading to 2,3-dihydropyrroles. In this context, the titled reaction represents a capable tool for the divergent synthesis of two types of synthetically valuable aza-heterocycles from common rhodium(II) iminocarbene intermediates. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Intermediate product selection and blending in the food processing industry

    NARCIS (Netherlands)

    Kilic, Onur A.; Akkerman, Renzo; van Donk, Dirk Pieter; Grunow, Martin

    2013-01-01

    This study addresses a capacitated intermediate product selection and blending problem typical for two-stage production systems in the food processing industry. The problem involves the selection of a set of intermediates and end-product recipes characterising how those selected intermediates are

  16. A Survey on Intermediation Architectures for Underwater Robotics

    Directory of Open Access Journals (Sweden)

    Xin Li

    2016-02-01

    Full Text Available Currently, there is a plethora of solutions regarding interconnectivity and interoperability for networked robots so that they will fulfill their purposes in a coordinated manner. In addition to that, middleware architectures are becoming increasingly popular due to the advantages that they are capable of guaranteeing (hardware abstraction, information homogenization, easy access for the applications above, etc.. However, there are still scarce contributions regarding the global state of the art in intermediation architectures for underwater robotics. As far as the area of robotics is concerned, this is a major issue that must be tackled in order to get a holistic view of the existing proposals. This challenge is addressed in this paper by studying the most compelling pieces of work for this kind of software development in the current literature. The studied works have been assessed according to their most prominent features and capabilities. Furthermore, by studying the individual pieces of work and classifying them several common weaknesses have been revealed and are highlighted. This provides a starting ground for the development of a middleware architecture for underwater robotics capable of dealing with these issues.

  17. A Sm(II)-mediated cascade approach to Dibenzoindolo[3,2-b]carbazoles : synthesis and evaluation

    OpenAIRE

    Levick, Matthew T.; Grace, Iain; Dai, Sheng-Yao; Kasch, Nicholas; Muryn, Christopher; Lambert, Colin; Turner, Michael L.; Procter, David J.

    2014-01-01

    Previously unstudied dibenzoindolo[3,2-b]carbazoles have been prepared by two-directional, phase tag-assisted synthesis utilizing a connective-Pummerer cyclization and a SmI2-mediated tag cleavage-cyclization cascade. The use of a phase tag allows us to exploit unstable intermediates that would otherwise need to be avoided. The novel materials were characterized by X-ray, cyclic voltammetry, UV-vis spectroscopy, TGA, and DSC. Preliminary studies on the performance of OFET devices are also des...

  18. Future possibilities with intermediate-energy neutron beams

    International Nuclear Information System (INIS)

    Brady, F.P.

    1987-01-01

    Future possibilities for using neutrons of intermediate energies (50 - 200 MeV) as a probe of the nucleus are discussed. Some of the recent thinking concerning a systematic approach for studying elastic and inelastic scattering of electrons and hadrons and the important role of medium- and intermediate-energy neutrons in such a programme is reviewed. The advantages of neutrons in this energy range over neutrons with lower energies and over intermediate-energy pions for determining nuclear-transition and ground state densities, and for distinguishing proton from neutron density (isovector sensitivity), are noted. The important role of (n,p) charge exchange reactions in nuclear excitation studies is also reviewed. Experimental methods for utilizing neutrons as probes in elastic, inelastic, and charge exchange studies at these energies are discussed

  19. The Intermediate Neutrino Program

    Energy Technology Data Exchange (ETDEWEB)

    Adams, C.; et al.

    2015-03-23

    The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summarizes discussion and conclusions from the workshop.

  20. The Intermediate Neutrino Program

    Energy Technology Data Exchange (ETDEWEB)

    Adams, C. [Yale Univ., New Haven, CT (United States); Alonso, J. R. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Ankowski, A. M. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Asaadi, J. A. [Syracuse Univ., NY (United States); Ashenfelter, J. [Yale Univ., New Haven, CT (United States); Axani, S. N. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Babu, K [Oklahoma State Univ., Stillwater, OK (United States); Backhouse, C. [California Inst. of Technology (CalTech), Pasadena, CA (United States); Band, H. R. [Yale Univ., New Haven, CT (United States); Barbeau, P. S. [Duke Univ., Durham, NC (United States); Barros, N. [Univ. of Pennsylvania, Philadelphia, PA (United States); Bernstein, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Betancourt, M. [Illinois Inst. of Technology, Chicago, IL (United States); Bishai, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Blucher, E. [Univ. of Chicago, IL (United States); Bouffard, J. [State Univ. of New York (SUNY), Albany, NY (United States); Bowden, N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brice, S. [Illinois Inst. of Technology, Chicago, IL (United States); Bryan, C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Camilleri, L. [Columbia Univ., New York, NY (United States); Cao, J. [Inst. of High Energy Physics, Beijing (China); Carlson, J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Carr, R. E. [Columbia Univ., New York, NY (United States); Chatterjee, A. [Univ. of Texas, Arlington, TX (United States); Chen, M. [Univ. of California, Irvine, CA (United States); Chen, S. [Tsinghua Univ., Beijing (China); Chiu, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Church, E. D. [Illinois Inst. of Technology, Chicago, IL (United States); Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Collar, J. I. [Univ. of Chicago, IL (United States); Collin, G. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Conrad, J. M. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Convery, M. R. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Cooper, R. L. [Indiana Univ., Bloomington, IN (United States); Cowen, D. [Pennsylvania State Univ., University Park, PA (United States); Davoudiasl, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gouvea, A. D. [Northwestern Univ., Evanston, IL (United States); Dean, D. J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Deichert, G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Descamps, F. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); DeYoung, T. [Michigan State Univ., East Lansing, MI (United States); Diwan, M. V. [Brookhaven National Lab. (BNL), Upton, NY (United States); Djurcic, Z. [Argonne National Lab. (ANL), Argonne, IL (United States); Dolinski, M. J. [Drexel Univ., Philadelphia, PA (United States); Dolph, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Donnelly, B. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Dwyer, D. A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dytman, S. [Univ. of Pittsburgh, PA (United States); Efremenko, Y. [Univ. of Tennessee, Knoxville, TN (United States); Everett, L. L. [Univ. of Wisconsin, Madison, WI (United States); Fava, A. [University of Padua, Padova (Italy); Figueroa-Feliciano, E. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Fleming, B. [Yale Univ., New Haven, CT (United States); Friedland, A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Fujikawa, B. K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gaisser, T. K. [Univ. of Delaware, Newark, DE (United States); Galeazzi, M. [Univ. of Miami, FL (United States); Galehouse, DC [Univ. of Akron, OH (United States); Galindo-Uribarri, A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Garvey, G. T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gautam, S. [Tribhuvan Univ., Kirtipur (Nepal); Gilje, K. E. [Illinois Inst. of Technology, Chicago, IL (United States); Gonzalez-Garcia, M. [Stony Brook Univ., NY (United States); Goodman, M. C. [Argonne National Lab. (ANL), Argonne, IL (United States); Gordon, H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Gramellini, E. [Yale Univ., New Haven, CT (United States); Green, M. P. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Guglielmi, A. [University of Padua, Padova (Italy); Hackenburg, R. W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hackenburg, A. [Yale Univ., New Haven, CT (United States); Halzen, F. [Univ. of Wisconsin, Madison, WI (United States); Han, K. [Yale Univ., New Haven, CT (United States); Hans, S. [Brookhaven National Lab. (BNL), Upton, NY (United States); Harris, D. [Illinois Inst. of Technology, Chicago, IL (United States); Heeger, K. M. [Yale Univ., New Haven, CT (United States); Herman, M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Hill, R. [Univ. of Chicago, IL (United States); Holin, A. [Univ. College London, Bloomsbury (United Kingdom); Huber, P. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Jaffe, D. E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Johnson, R. A. [Univ. of Cincinnati, OH (United States); Joshi, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Karagiorgi, G. [Univ. of Manchester (United Kingdom); Kaufman, L. J. [Indiana Univ., Bloomington, IN (United States); Kayser, B. [Illinois Inst. of Technology, Chicago, IL (United States); Kettell, S. H. [Brookhaven National Lab. (BNL), Upton, NY (United States); Kirby, B. J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Klein, J. R. [Univ. of Texas, Arlington, TX (United States); Kolomensky, Y. G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Kriske, R. M. [Univ. of Minnesota, Minneapolis, MN (United States); Lane, C. E. [Drexel Univ., Philadelphia, PA (United States); Langford, T. J. [Yale Univ., New Haven, CT (United States); Lankford, A. [Univ. of California, Irvine, CA (United States); Lau, K. [Univ. of Houston, TX (United States); Learned, J. G. [Univ. of Hawaii, Honolulu, HI (United States); Ling, J. [Univ. of Illinois, Urbana-Champaign, IL (United States); Link, J. M. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Lissauer, D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Littenberg, L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Littlejohn, B. R. [Illinois Inst. of Technology, Chicago, IL (United States); Lockwitz, S. [Illinois Inst. of Technology, Chicago, IL (United States); Lokajicek, M. [Inst. of Physics of the Academy of Sciences of Czech Republic, Prague (Czech Republic); Louis, W. C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Luk, K. [Univ. of California, Berkeley, CA (United States); Lykken, J. [Illinois Inst. of Technology, Chicago, IL (United States); Marciano, W. J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Maricic, J. [Univ. of Hawaii, Honolulu, HI (United States); Markoff, D. M. [North Carolina Central Univ., Durham, NC (United States); Caicedo, D. A. M. [Illinois Inst. of Technology, Chicago, IL (United States); Mauger, C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mavrokoridis, K. [Univ. of Liverpool (United Kingdom); McCluskey, E. [Illinois Inst. of Technology, Chicago, IL (United States); McKeen, D. [Univ. of Washington, Seattle, WA (United States); McKeown, R. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Mills, G. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mocioiu, I. [Pennsylvania State Univ., University Park, PA (United States); Monreal, B. [Univ. of California, Santa Barbara, CA (United States); Mooney, M. R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Morfin, J. G. [Illinois Inst. of Technology, Chicago, IL (United States); Mumm, P. [National Inst. of Standards and Technology (NIST), Boulder, CO (United States); Napolitano, J. [Temple Univ., Philadelphia, PA (United States); Neilson, R. [Drexel Univ., Philadelphia, PA (United States); Nelson, J. K. [College of William and Mary, Williamsburg, VA (United States); Nessi, M. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Norcini, D. [Yale Univ., New Haven, CT (United States); Nova, F. [Univ. of Texas, Austin, TX (United States); Nygren, D. R. [Univ. of Texas, Arlington, TX (United States); Gann, GDO [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States); Palamara, O. [Illinois Inst. of Technology, Chicago, IL (United States); Parsa, Z. [Brookhaven National Lab. (BNL), Upton, NY (United States); Patterson, R. [California Inst. of Technology (CalTech), Pasadena, CA (United States); Paul, P. [Stony Brook Univ., NY (United States); Pocar, A. [Univ. of Massachusetts, Amherst, MA (United States); Qian, X. [Brookhaven National Lab. (BNL), Upton, NY (United States); Raaf, J. L. [Illinois Inst. of Technology, Chicago, IL (United States); Rameika, R. [Illinois Inst. of Technology, Chicago, IL (United States); Ranucci, G. [National Inst. of Nuclear Physics, Milano (Italy); Ray, H. [Univ. of Florida, Gainesville, FL (United States); Reyna, D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rich, G. C. [Triangle Universities Nuclear Lab., Durham, NC (United States); Rodrigues, P. [Univ. of Rochester, NY (United States); Romero, E. R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of Tennessee, Knoxville, TN (United States); Rosero, R. [Brookhaven National Lab. (BNL), Upton, NY (United States); Rountree, S. D. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Rybolt, B. [Univ. of Tennessee, Knoxville, TN (United States); Sanchez, M. C. [Iowa State Univ., Ames, IA (United States); Santucci, G. [Stony Brook Univ., NY (United States); Schmitz, D. [Univ. of Chicago, IL (United States); Scholberg, K. [Duke Univ., Durham, NC (United States); Seckel, D. [Univ. of Delaware, Newark, DE (United States); Shaevitz, M. [Columbia Univ., New York, NY (United States); Shrock, R. [Stony Brook Univ., NY (United States); Smy, M. B. [Univ. of California, Irvine, CA (United States); Soderberg, M. [Syracuse Univ., NY (United States); Sonzogni, A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Sousa, A. B. [Univ. of Cincinnati, OH (United States); Spitz, J. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); John, J. M. S. [Univ. of Cincinnati, OH (United States); Stewart, J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Strait, J. B. [Illinois Inst. of Technology, Chicago, IL (United States); Sullivan, G. [Univ. of Maryland, College Park, MD (United States); Svoboda, R. [Univ. of California, Davis, CA (United States); Szelc, A. M. [Yale Univ., New Haven, CT (United States); Tayloe, R. [Indiana Univ., Bloomington, IN (United States); Thomson, M. A. [Univ. of Cambridge (United Kingdom); Toups, M. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Vacheret, A. [Univ. of Oxford (United Kingdom); Vagins, M. [Univ. of California, Irvine, CA (United States); Water, R. G. V. D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vogelaar, R. B. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Weber, M. [Bern (Switzerland); Weng, W. [Brookhaven National Lab. (BNL), Upton, NY (United States); Wetstein, M. [Univ. of Chicago, IL (United States); White, C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); White, B. R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Whitehead, L. [Univ. of Houston, TX (United States); Whittington, D. W. [Indiana Univ., Bloomington, IN (United States); Wilking, M. J. [Stony Brook Univ., NY (United States); Wilson, R. J. [Colorado State Univ., Fort Collins, CO (United States); Wilson, P. [Illinois Inst. of Technology, Chicago, IL (United States); Winklehner, D. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Winn, D. R. [Fairfield Univ., CT (United States); Worcester, E. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yang, L. [Univ. of Illinois, Urbana-Champaign, IL (United States); Yeh, M [Brookhaven National Lab. (BNL), Upton, NY (United States); Yokley, Z. W. [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States); Yoo, J. [Illinois Inst. of Technology, Chicago, IL (United States); Yu, B. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yu, J. [Univ. of Texas, Arlington, TX (United States); Zhang, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-04-03

    The US neutrino community gathered at the Workshop on the Intermediate Neutrino Program (WINP) at Brookhaven National Laboratory February 4-6, 2015 to explore opportunities in neutrino physics over the next five to ten years. Scientists from particle, astroparticle and nuclear physics participated in the workshop. The workshop examined promising opportunities for neutrino physics in the intermediate term, including possible new small to mid-scale experiments, US contributions to large experiments, upgrades to existing experiments, R&D plans and theory. The workshop was organized into two sets of parallel working group sessions, divided by physics topics and technology. Physics working groups covered topics on Sterile Neutrinos, Neutrino Mixing, Neutrino Interactions, Neutrino Properties and Astrophysical Neutrinos. Technology sessions were organized into Theory, Short-Baseline Accelerator Neutrinos, Reactor Neutrinos, Detector R&D and Source, Cyclotron and Meson Decay at Rest sessions.This report summarizes discussion and conclusions from the workshop.

  1. Synthesis of High Purity Nonsymmetric Dialkylphosphinic Acid Extractants.

    Science.gov (United States)

    Wang, Junlian; Xie, Meiying; Liu, Xinyu; Xu, Shengming

    2017-10-19

    We present the synthesis of (2,3-dimethylbutyl)(2,4,4'-trimethylpentyl)phosphinic acid as an example to demonstrate a method for the synthesis of high purity nonsymmetric dialkylphosphinic acid extractants. Low toxic sodium hypophosphite was chosen as the phosphorus source to react with olefin A (2,3-dimethyl-1-butene) to generate a monoalkylphosphinic acid intermediate. Amantadine was adopted to remove the dialkylphosphinic acid byproduct, as only the monoalkylphosphinic acid can react with amantadine to form an amantadine∙mono-alkylphosphinic acid salt, while the dialkylphosphinic acid cannot react with amantadine due to its large steric hindrance. The purified monoalkylphosphinic acid was then reacted with olefin B (diisobutylene) to yield nonsymmetric dialkylphosphinic acid (NSDAPA). The unreacted monoalkylphosphinic acid can be easily removed by a simple base-acid post-treatment and other organic impurities can be separated out through the precipitation of the cobalt salt. The structure of the (2,3-dimethylbutyl)(2,4,4'-trimethylpentyl)phosphinic acid was confirmed by 31 P NMR, 1 H NMR, ESI-MS, and FT-IR. The purity was determined by a potentiometric titration method, and the results indicate that the purity can exceed 96%.

  2. Comments on intermediate-scale models

    International Nuclear Information System (INIS)

    Ellis, J.; Enqvist, K.; Nanopoulos, D.V.; Olive, K.

    1987-01-01

    Some superstring-inspired models employ intermediate scales m I of gauge symmetry breaking. Such scales should exceed 10 16 GeV in order to avoid prima facie problems with baryon decay through heavy particles and non-perturbative behaviour of the gauge couplings above m I . However, the intermediate-scale phase transition does not occur until the temperature of the Universe falls below O(m W ), after which an enormous excess of entropy is generated. Moreover, gauge symmetry breaking by renormalization group-improved radiative corrections is inapplicable because the symmetry-breaking field has not renormalizable interactions at scales below m I . We also comment on the danger of baryon and lepton number violation in the effective low-energy theory. (orig.)

  3. to view fulltext PDF

    Indian Academy of Sciences (India)

    345 a-alkoxy acid. Design, synthesis and computational validation of novel ... Two expedient 'one-pot' methods for synthesis of ..... Atom transfer radical polymerization (ATRP). Synthesis and ..... Emission and absorption titrations. Synthesis ...

  4. Surface Intermediate Zone of Submerged Turbulent Buoyant Jet in Current

    DEFF Research Database (Denmark)

    Chen, H. B.; Larsen, Torben

    1995-01-01

    This paper deals with the intermediate zone between the jet and plume stages of a submerged buoyant discharge from sea outfall in current. The stability criteria, plume width and height after the intermediate zone and the dilution within the intermediate region have been studied theoretically and...

  5. Computational uncertainties in silicon dioxide/plutonium intermediate neutron spectrum systems

    International Nuclear Information System (INIS)

    Jaegers, P.J.

    1997-01-01

    In the past several years, several proposals have been made for the long-term stabilization and storage of surplus fissile materials. Many of these proposed scenarios involve systems that have an intermediate neutron energy spectrum. Such intermediate-energy systems are dominated by scattering and fission events induced by neutrons ranging in energy from 1 eV to 100keV. To ensure adequate safety margins and cost effectiveness, it is necessary to have benchmark data for these intermediate-energy spectrum systems; however, a review of the nuclear criticality benchmarks indicates that no formal benchmarks are available. Nuclear data uncertainties have been reported for some types of intermediate-energy spectrum systems. Using a variety of Monte Carlo computer codes and cross-section sets, reported significant variations in the calculated k ∞ of intermediate-energy spectrum metal/ 235 U systems. We discuss the characteristics of intermediate neutron spectrum systems and some of the computational differences that can occur in calculating the k eff of these systems

  6. On the stability of rotational discontinuities and intermediate shocks

    International Nuclear Information System (INIS)

    Lee, L.C.; Huang, L.; Chao, J.K.

    1989-01-01

    The stability of rotational discontinuities and intermediate shocks is studied based on a hybrid simulation code. The simulation results show that rotational discontinuities are stable and intermediate shocks are not stationary. Intermediate shocks tend to evolve to rotational discontinuities and waves. The authors employ several different initial profiles for the magnetic field in the transition region and find that the final structure of the discontinuities or shocks is not sensitive to the initial magnetic field profile. The present results are different from those obtained from the resistive MHD simulations. Furthermore, their study indicates that the kinetic effect of particles plays an important role in the structure and stability of rotational discontinuities and intermediate shocks

  7. Bacterial cellulose synthesis mechanism of facultative anaerobe Enterobacter sp. FY-07.

    Science.gov (United States)

    Ji, Kaihua; Wang, Wei; Zeng, Bing; Chen, Sibin; Zhao, Qianqian; Chen, Yueqing; Li, Guoqiang; Ma, Ting

    2016-02-25

    Enterobacter sp. FY-07 can produce bacterial cellulose (BC) under aerobic and anaerobic conditions. Three potential BC synthesis gene clusters (bcsI, bcsII and bcsIII) of Enterobacter sp. FY-07 have been predicted using genome sequencing and comparative genome analysis, in which bcsIII was confirmed as the main contributor to BC synthesis by gene knockout and functional reconstitution methods. Protein homology, gene arrangement and gene constitution analysis indicated that bcsIII had high identity to the bcsI operon of Enterobacter sp. 638; however, its arrangement and composition were same as those of BC synthesizing operon of G. xylinum ATCC53582 except for the flanking sequences. According to the BC biosynthesizing process, oxygen is not directly involved in the reactions of BC synthesis, however, energy is required to activate intermediate metabolites and synthesize the activator, c-di-GMP. Comparative transcriptome and metabolite quantitative analysis demonstrated that under anaerobic conditions genes involved in the TCA cycle were downregulated, however, genes in the nitrate reduction and gluconeogenesis pathways were upregulated, especially, genes in three pyruvate metabolism pathways. These results suggested that Enterobacter sp. FY-07 could produce energy efficiently under anaerobic conditions to meet the requirement of BC biosynthesis.

  8. Evaluation of an automated double-synthesis module: efficiency and reliability of subsequent radiosyntheses of FHBG and FLT

    International Nuclear Information System (INIS)

    Niedermoser, Sabrina; Pape, Manuela; Gildehaus, Franz Josef; Wängler, Carmen; Hartenbach, Markus; Schirrmacher, Ralf; Bartenstein, Peter; Wängler, Björn

    2012-01-01

    We optimized the synthesis methods for 3′-deoxy-3′-[ 18 F]fluorothymidine ([ 18 F]FLT) and 9-(4-[ 18 F]fluoro-3-[hydroxymethyl]butyl)guanine) ([ 18 F]FHBG) and automated them on an Explora General Nucleophilic double-synthesis module. Furthermore, the synthesis efficiency and reliability and the formation of cross-contaminations of the products when preparing two consecutive batches were evaluated. Whereas the preinstalled FLT synthesis conditions required substantial modification in reaction and neutralization conditions to achieve radiochemical yields of up to 60% within 70±10 min including high-performance liquid chromatography purification, the synthesis of FHBG had to be implemented to the module to obtain competitive radiochemical yields of up to 40% in an overall synthesis time of 60±10 min. The radiochemical purities obtained were ≥99% and ≥96% for the synthesis of [ 18 F]FLT and [ 18 F]FHBG, respectively. No significant changes in yield or purity could be observed between both batch productions. We found that the yields and purities also did not change when performing FLT after FHBG syntheses and vice versa. Hence, we developed a synthesis setup that offers the opportunity to perform two subsequent syntheses of either [ 18 F]FLT, [ 18 F]FHBG or [ 18 F]FLT after [ 18 F]FHBG without decrease in radiochemical yields and purities. Also, no cross-contaminations were observed, which can be attributed to the use of separate product delivery tubes, purification columns and an automated intermediate cleaning program. These results open up the possibility of producing consecutively either two equal 18 F-fluorinated tracers or two different ones in high yields on the same synthesis module.

  9. Formation of adenosine 5'-tetraphosphate from the acyl phosphate intermediate: a difference between the MurC and MurD synthetases of Escherichia coli.

    Science.gov (United States)

    Bouhss, A; Dementin, S; van Heijenoort, J; Parquet, C; Blanot, D

    1999-06-18

    The mechanism of the Mur synthetases of peptidoglycan biosynthesis is thought to involve in each case the successive formation of an acyl phosphate and a tetrahedral intermediate. The existence of the acyl phosphates for the MurC and MurD enzymes from Escherichia coli was firmly established by their in situ reduction by sodium borohydride followed by acid hydrolysis, yielding the corresponding amino alcohols. Furthermore, it was found that MurD, but not MurC, catalyses the synthesis of adenosine 5'-tetraphosphate from the acyl phosphate, thereby substantiating its existence and pointing out a difference between the two enzymes.

  10. MULTICOMPONENT AND REGIOSELECTIVE SYNTHESIS OF DIHYDROPYRAZOLO[1,5-a]PYRIMIDINES FROM AROMATIC ALDEHYDES, MELDRUM'S ACID AND AMINOPYRAZOLE CAN508

    OpenAIRE

    Jedinák, L.; Kryštof, V. (Vladimír); Trávníček, Z.; Cankař, P.

    2014-01-01

    A regioselective synthesis of dihydropyrazolo[1,5-a]pyrimidines is reported. The multicomponent reaction of readily available arylaldehydes, Meldrum's acid, and aminopyrazole CAN508 afforded fused pyrazolopyrimidines in high yields. The reaction proceeded regioselectively via initial Michael addition of the exocyclic amino group to arylidene Meldrum's acid intermediate followed by a ring closure at the endocyclic nitrogen of aminopyrazole. The regioselectivity of the reaction was determined b...

  11. MNE Entrepreneurial Capabilities at Intermediate Levels

    DEFF Research Database (Denmark)

    Hoenen, Anne K.; Nell, Phillip Christopher; Ambos, Björn

    2014-01-01

    at intermediate geographical levels differ from local subsidiaries and global corporate headquarters, and why those differences are important. We illustrate our arguments using data on European regional headquarters (RHQs). We find that RHQs' entrepreneurial capabilities depend on their external embeddedness...... and on the heterogeneous information that is generated through dissimilar markets within the region. Our study opens up for an interesting discussion of the independence of these mechanisms. In sum, we contribute to the understanding of the entrepreneurial role of intermediate units in general and RHQs in particular....

  12. Financial Intermediation and Economic Growth of Jordan 1964-1988

    OpenAIRE

    Magableh, Ali H.

    1995-01-01

    Until recently, the economics and financial literature placed little attention on the role that financial intermediation can play in accelerating the rate of economic development in less Developed Countries (LDCs). This has been changed now, however, where some instrumental role has been emphasised for financial intermediation in the process of economic development and growth. It is argued that an expansion of the financial system, size and intermediation in LDCs tends to increase the level o...

  13. Perspective: Spectroscopy and kinetics of small gaseous Criegee intermediates

    International Nuclear Information System (INIS)

    Lee, Yuan-Pern

    2015-01-01

    The Criegee intermediates, carbonyl oxides proposed by Criegee in 1949 as key intermediates in the ozonolysis of alkenes, play important roles in many aspects of atmospheric chemistry. Because direct detection of these gaseous intermediates was unavailable until recently, previous understanding of their reactions, derived from indirect experimental evidence, had great uncertainties. Recent laboratory detection of the simplest Criegee intermediate CH 2 OO and some larger members, produced from ultraviolet irradiation of corresponding diiodoalkanes in O 2 , with various methods such as photoionization, ultraviolet absorption, infrared absorption, and microwave spectroscopy opens a new door to improved understanding of the roles of these Criegee intermediates. Their structures and spectral parameters have been characterized; their significant zwitterionic nature is hence confirmed. CH 2 OO, along with other products, has also been detected directly with microwave spectroscopy in gaseous ozonolysis reactions of ethene. The detailed kinetics of the source reaction, CH 2 I + O 2 , which is critical to laboratory studies of CH 2 OO, are now understood satisfactorily. The kinetic investigations using direct detection identified some important atmospheric reactions, including reactions with NO 2 , SO 2 , water dimer, carboxylic acids, and carbonyl compounds. Efforts toward the characterization of larger Criegee intermediates and the investigation of related reactions are in progress. Some reactions of CH 3 CHOO are found to depend on conformation. This perspective examines progress toward the direct spectral characterization of Criegee intermediates and investigations of the associated reaction kinetics, and indicates some unresolved problems and prospective challenges for this exciting field of research

  14. Surface intermediates on metal electrodes at high temperatures

    DEFF Research Database (Denmark)

    Zachau-Christiansen, Birgit; Jacobsen, Torben; Bay, Lasse

    1998-01-01

    The mechanisms widely conceived for the O(2)-reduction or H(2)-oxidation reactions in SOFC's involve intermediate O/H species adsorbed on the electrode surface. The presence of these intermediates is investigated by linear sweep voltammetry. In air at moderate temperatures (500 degrees C) Pt...

  15. Imaging of Enzymes in the Steroid Biosynthetic Pathway: Synthesis of 18F-Labelled Tracers

    International Nuclear Information System (INIS)

    Erlandsson, Maria

    2009-01-01

    This thesis deals with the synthesis and development of 18 F-labelled alkyl etomidate and vorozole analogues, and their use as positron emission tomography (PET) tracers for the imaging of the steroid enzymes 11β-hydroxylase and aromatase. Two synthetic 18 F-labelling approaches to the etomidate and vorozole analogues were developed, and the analogues were evaluated in some biological assays. The two-step labelling method was used to synthesise many compounds for biological evaluation. In the first step, a 18 F-labelled intermediate based on a ditosylate or a halogenated diethyl ether was synthesised and used directly in the next alkylation step. The decay-corrected (d.c.) radiochemical yield was higher compared to other known two-step labelling methods. Once an appropriate candidate has been chosen for clinical evaluation, a one-step labelling method will be more suitable. We therefore developed a method based on precursors that had leaving groups at the end of their alkyl chains, and used these directly in the 18 F-labelling synthesis. The one-step 18 F-labelling synthesis required less reaction time and produced higher specific radioactivity and d.c. radiochemical yield than our two-step synthesis. With microwave heating, the reaction time was reduced to seconds and the d.c. radiochemical yield was better than that obtained with conventional heating. The one-step synthesis simplified the technical handling by allowing the tracer syntheses to be automated on the TRACERLab FX FN

  16. Stereoselective Catalytic Synthesis of Active Pharmaceutical Ingredients in Homemade 3D-Printed Mesoreactors.

    Science.gov (United States)

    Rossi, Sergio; Porta, Riccardo; Brenna, Davide; Puglisi, Alessandra; Benaglia, Maurizio

    2017-04-03

    3D-printed flow reactors were designed, fabricated from different materials (PLA, HIPS, nylon), and used for a catalytic stereoselective Henry reaction. The use of readily prepared and tunable 3D-printed reactors enabled the rapid screening of devices with different sizes, shapes, and channel dimensions, aimed at the identification of the best-performing reactor setup. The optimized process afforded the products in high yields, moderate diastereoselectivity, and up to 90 % ee. The method was applied to the continuous-flow synthesis of biologically active chiral 1,2-amino alcohols (norephedrine, metaraminol, and methoxamine) through a two-step sequence combining the nitroaldol reaction with a hydrogenation. To highlight potential industrial applications of this method, a multistep continuous synthesis of norephedrine has been realized. The product was isolated without any intermediate purifications or solvent switches. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Total Synthesis of Zoanthamine Alkaloids, Part 2. Construction of the C1-C5, C6-C10 and C11-C24 Fragments of Zoanthamine

    DEFF Research Database (Denmark)

    Tanner, David Ackland; Tedenborg, Lars; Somfai, Peter

    1997-01-01

    This paper describes the construction of three key intermediates for a projected total synthesis of the marine alkaloid zoanthamine. These building blocks, corresponding to the C1-C5, C6-C10 and C11-C24 fragments of the target molecule, are synthesised efficiently form (R...

  18. Synthesis of alkyl phenols by means of radiofrequency plasmas

    International Nuclear Information System (INIS)

    Ropero, M.; Armas, F.; Iacocca, D.; Patino, P.

    1992-01-01

    New and promising possibilities in chemical synthesis have been opened through the interactions of oxygen plasmas with liquid alkyl benzene compounds. The alkyl phenols are the main products of the reaction mixtures (> 80%) oxygen, excited by radio-frequency (R.F.) is allowed to reach the surface of the liquid organic compound. The R.F. power supply is a Branson/IPC-PM 118. The substrate we have chosen are: methyl, ethyl, propyl, n-butyl, t-butyl, dimethyl and trimethyl benzenes. Under the same O 2 pressure and a power of 60 W, m-xylene and mesethylene behaved similarly. For all these substrates, values for the temperature of the liquid surface seem to indicate that oxidation tends to an optimum when P O 2 /vapor pressure (substrate) is higher than 20. In our experiments oxygen pressure in the reactor was about 0.2 Torr. Oxidation is basically attributed to O 3 P and the addition to alkyl benzenes selectively takes place on the aromatic rings, at low reactor pressure. The oxygen atom impinges on the liquid surface and epoxy intermediates could be formed. These intermediates then progress to the corresponding phenols. (author)

  19. Intermediate-Mass Black Holes

    Science.gov (United States)

    Miller, M. Coleman; Colbert, E. J. M.

    2004-01-01

    The mathematical simplicity of black holes, combined with their links to some of the most energetic events in the universe, means that black holes are key objects for fundamental physics and astrophysics. Until recently, it was generally believed that black holes in nature appear in two broad mass ranges: stellar-mass (M~3 20 M⊙), which are produced by the core collapse of massive stars, and supermassive (M~106 1010 M⊙), which are found in the centers of galaxies and are produced by a still uncertain combination of processes. In the last few years, however, evidence has accumulated for an intermediate-mass class of black holes, with M~102 104 M⊙. If such objects exist they have important implications for the dynamics of stellar clusters, the formation of supermassive black holes, and the production and detection of gravitational waves. We review the evidence for intermediate-mass black holes and discuss future observational and theoretical work that will help clarify numerous outstanding questions about these objects.

  20. The Path of Carbon in Photosynthesis XVI. Kinetic Relationships of the Intermediates in Steady State Photosynthesis

    Science.gov (United States)

    Benson, A. A.; Kawaguchi, S.; Hayes, P.; Calvin, M.

    1952-06-05

    A kinetic study of the accumulation of C{sup 14} in the intermediates of steady state photosynthesis in C{sup 14}O{sub 2} provides information regarding the sequence of reactions involved. The work described applied the radio-chromatographic technique for analysis of the labeled early products. The simultaneous carboxylation reaction resulting in malic acid as well as phosphoglycerate is demonstrated in experiments at high light intensity. A comparison of radioactivities in a number of phosphorylated sugars as a function of time reveals concurrent synthesis of fructose and sedoheptulose phosphates followed by that of ribulose phosphates and later by that of glucose phosphates. The possibility that the cleavage of C{sub 4} compounds to C{sub 2} carbon dioxide acceptors may involve C{sub 7} and C{sub 5} sugars and evidence for this mechanism is presented.

  1. Intermediate Levels of Visual Processing

    National Research Council Canada - National Science Library

    Nakayama, Ken

    1998-01-01

    ...) surface representation, here we have shown that there is an intermediate level of visual processing, between the analysis of the image and higher order representations related to specific objects; (2...

  2. Intermediate energy proton and light-ion scattering

    International Nuclear Information System (INIS)

    Moss, J.M.

    1981-01-01

    A review is presented of recent (1979-81) developments in the field of intermediate-energy proton and light-ion scattering from nuclei. New theoretical and calculational techniques of particular interest to experimentalists are discussed. Emphasis is placed on topics in nuclear structure physics - giant resonances, pion-condensation precursor phenomena, and polarization transfer (spin-flip) experiments - where intermediate energy proton and light-ion scattering has made new and unique contributions

  3. Comments on intermediate-scale models

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, J.; Enqvist, K.; Nanopoulos, D.V.; Olive, K.

    1987-04-23

    Some superstring-inspired models employ intermediate scales m/sub I/ of gauge symmetry breaking. Such scales should exceed 10/sup 16/ GeV in order to avoid prima facie problems with baryon decay through heavy particles and non-perturbative behaviour of the gauge couplings above m/sub I/. However, the intermediate-scale phase transition does not occur until the temperature of the Universe falls below O(m/sub W/), after which an enormous excess of entropy is generated. Moreover, gauge symmetry breaking by renormalization group-improved radiative corrections is inapplicable because the symmetry-breaking field has not renormalizable interactions at scales below m/sub I/. We also comment on the danger of baryon and lepton number violation in the effective low-energy theory.

  4. Gold-catalyzed Bicyclization of Diaryl Alkynes: Synthesis of Polycyclic Fused Indole and Spirooxindole Derivatives.

    Science.gov (United States)

    Cai, Ju; Wu, Bing; Rong, Guangwei; Zhang, Cheng; Qiu, Lihua; Xu, Xinfang

    2018-04-13

    An unprecedented gold-catalyzed bicyclization reaction of diaryl alkynes has been developed for the synthesis of indoles in good to high yields. Mechanistically, this alkyne bifunctionalization transformation was terminated by a stepwise formal X-H insertion reaction to furnish the corresponding polycyclic-frameworks with structural diversity, and the key intermediate 3 H-indole was isolated and characterized for the first time. In addition, further transformation of these generated tetracyclic-indoles with PCC as the oxidant provided straightforward access to the spirooxindoles in high yields.

  5. Enzymatic synthesis of tasty oligopeptide in organic solvent. Yuki yobaichu deno teimisei origo pepuchido no koso gosei

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, T.; Tomita, K.; Nakanishi, K. (Okayama Univ., Okayama (Japan). Faculty of Engineering)

    1991-10-01

    An introduction is made to examples of the latest researches on methods to manufacture oligopeptides by enzymatic synthesizing methods in regards to to various processes using reactions in organic solvents as a means to increase the yield, particularly on synthesis of one that have taste effects. To raise the yield of peptides that are produced by condensing amino acid and amino acid derivatives, it is necessary that an equilibrium control reaction is operated in such a way that the product concentration and product moisture concentration are reduced, and the concentration of substrates of non-dissociation type is raised. In the case ofamino acid reacting with amino acid ester or amide, a velocity control is carried out, in which the velocity to produce the peptides from the acyl intermediates is raised and the velocity of the ester hydrolysis is slowed down. Examples of synthesis of tasty oligopeptides include, for example, the precursor in manufacturing artificial sweetener, aspartyl-phenylalanine methyl, as well as synthesis in an aqueous solution using special enzymes or in an organic solvent, and synthesis of other acidic amino acid oligomers. 24 refs., 2 figs.

  6. Proceedings of the Workshop on Program Options in Intermediate-Energy Physics. Keynote address: New directions in intermediate-energy nuclear physics

    International Nuclear Information System (INIS)

    Brown, G.E.

    1980-05-01

    This report presents the keynote address given by G.E. Brown at a LASL colloquium on August 21, 1979, for the Workshop on Program Options in Intermediate-Energy Physics. Professor Brown reviewed major topics of interest in intermediate-energy nuclear physics and suggested experimental approaches that might be most productive in the near future. 22 figures

  7. Dominant Modes in Light Nuclei - Ab Initio View of Emergent Symmetries

    International Nuclear Information System (INIS)

    Draayer, J P; Dytrych, T; Launey, K D; Dreyfuss, A C; Langr, D

    2015-01-01

    An innovative symmetry-guided concept is discussed with a focus on emergent symmetry patterns in complex nuclei. In particular, the ab initio symmetry-adapted no-core shell model (SA-NCSM), which capitalizes on exact as well as partial symmetries that underpin the structure of nuclei, provides remarkable insight into how simple symmetry patterns emerge in the many-body nuclear dynamics from first principles. This ab initio view is complemented by a fully microscopic no-core symplectic shell-model framework (NCSpM), which, in turn, informs key features of the primary physics responsible for the emergent phenomena of large deformation and alpha-cluster substructures in studies of the challenging Hoyle state in Carbon-12 and enhanced collectivity in intermediate-mass nuclei. Furthermore, by recognizing that deformed configurations often dominate the low-energy regime, the SA-NCSM provides a strategy for determining the nature of bound states of nuclei in terms of a relatively small subspace of the symmetry-reorganized complete model space, which opens new domains of nuclei for ab initio investigations, namely, the intermediate-mass region, including isotopes of Ne, Mg, and Si

  8. Exploiting the acylating nature of the imide-Ugi intermediate: a straightforward synthesis of tetrahydro-1,4-benzodiazepin-2-ones.

    Science.gov (United States)

    Mossetti, Riccardo; Saggiorato, Dèsirèe; Tron, Gian Cesare

    2011-12-16

    We describe a simple and novel protocol for the synthesis of tetrahydro-1,4-benzodiazepin-2-ones with three points of diversity, exploiting the acylating properties of the recently rediscovered Ugi-imide. The final compounds can be easily prepared in three synthetic steps using a multicomponent reaction, a Staudinger reduction, and an acylative protocol, with good to excellent yields for each synthetic step.

  9. A practical synthesis of a gamma-secretase inhibitor.

    Science.gov (United States)

    Scott, Jeremy P; Lieberman, David R; Beureux, Olivier M; Brands, Karel M J; Davies, Antony J; Gibson, Andrew W; Hammond, Deborah C; McWilliams, Chris J; Stewart, Gavin W; Wilson, Robert D; Dolling, Ulf-H

    2007-05-25

    A practical and scaleable synthesis of the gamma-secretase inhibitor 1 is reported. The inhibitor consists of a central trisubstituted cyclohexane core with appended propionic acid, 2,5-difluorophenyl, and 4-chlorophenylsulfonyl moieties. Two alternative synthetic strategies, proceeding by way of a common disubstituted cyclohexanone derivative 5, were studied. In the preferred route, conjugate reduction of acrylonitrile derivative 4 with L-Selectride configures the desired relative stereochemistry of the cyclohexane core with >99.9:0.1 dr. A second strategy, based on catalyst-controlled hydrogenation of racemic cyclohexene derivative 2, is more convergent but less diastereoselective (up to 75:25 dr). The common cyclohexanone intermediate 5 was constructed by a regioselective Diels-Alder condensation of a 1,1-disubstituted vinyl sulfone 6 with 2-trimethylsiloxybutadiene.

  10. Projecting non-diffracting waves with intermediate-plane holography.

    Science.gov (United States)

    Mondal, Argha; Yevick, Aaron; Blackburn, Lauren C; Kanellakopoulos, Nikitas; Grier, David G

    2018-02-19

    We introduce intermediate-plane holography, which substantially improves the ability of holographic trapping systems to project propagation-invariant modes of light using phase-only diffractive optical elements. Translating the mode-forming hologram to an intermediate plane in the optical train can reduce the need to encode amplitude variations in the field, and therefore complements well-established techniques for encoding complex-valued transfer functions into phase-only holograms. Compared to standard holographic trapping implementations, intermediate-plane holograms greatly improve diffraction efficiency and mode purity of propagation-invariant modes, and so increase their useful non-diffracting range. We demonstrate this technique through experimental realizations of accelerating modes and long-range tractor beams.

  11. Green synthesis of noble nanometals (Au, Pt, Pd) using glycerol under microwave irradiation conditions

    Science.gov (United States)

    A newer application of glycerol in the field of nanomaterials synthesis has been developed from both the economic and environmental points of view. Glycerol can act as a reducing agent for the fabrication of noble nanometals, such as Au, Pt, and Pd, under microwave irradiation. T...

  12. What do young people think about their school-based sex and relationship education? A qualitative synthesis of young people's views and experiences.

    Science.gov (United States)

    Pound, Pandora; Langford, Rebecca; Campbell, Rona

    2016-09-13

    Although sex and relationship education (SRE) represents a key strand in policies to safeguard young people and improve their sexual health, it currently lacks statutory status, government guidance is outdated and a third of UK schools has poor-quality SRE. We aimed to investigate whether current provision meets young people's needs. Synthesis of qualitative studies of young people's views of their school-based SRE. Eligible studies originated from the UK, Ireland, the USA, Australia, New Zealand, Canada, Japan, Iran, Brazil and Sweden. Studies of students aged 4-19 in full-time education, young adults ≤19 (not necessarily in full-time education) or adults ≤25 if recalling their experiences of school-based SRE. -69 publications were identified, with 55 remaining after quality appraisal (representing 48 studies). The synthesis found that although sex is a potent and potentially embarrassing topic, schools appear reluctant to acknowledge this and attempt to teach SRE in the same way as other subjects. Young people report feeling vulnerable in SRE, with young men anxious to conceal sexual ignorance and young women risking sexual harassment if they participate. Schools appear to have difficulty accepting that some young people are sexually active, leading to SRE that is out of touch with many young people's lives. Young people report that SRE can be negative, gendered and heterosexist. They expressed dislike of their own teachers delivering SRE due to blurred boundaries, lack of anonymity, embarrassment and poor training. SRE should be 'sex-positive' and delivered by experts who maintain clear boundaries with students. Schools should acknowledge that sex is a special subject with unique challenges, as well as the fact and range of young people's sexual activity, otherwise young people will continue to disengage from SRE and opportunities for safeguarding and improving their sexual health will be reduced. Published by the BMJ Publishing Group Limited. For permission

  13. Surface Intermediates on Metal Electrodes at High Temperature

    DEFF Research Database (Denmark)

    Zachau-Christiansen, Birgit; Jacobsen, Torben; Bay, Lasse

    1997-01-01

    The mechanisms widely suggested for the O2-reduc-tion or H2-oxidation SOFC reactions involve inter-mediate O/H species adsorbed on the electrode surface. The presence of these intermediates is investigated by linear sweep voltammetry. In airat moderate temperatures (500øC) Pt in contact with YSZ...

  14. Processing and validation of intermediate energy evaluated data files

    International Nuclear Information System (INIS)

    2000-01-01

    Current accelerator-driven and other intermediate energy technologies require accurate nuclear data to model the performance of the target/blanket assembly, neutron production, activation, heating and damage. In a previous WPEC subgroup, SG13 on intermediate energy nuclear data, various aspects of intermediate energy data, such as nuclear data needs, experiments, model calculations and file formatting issues were investigated and categorized to come to a joint evaluation effort. The successor of SG13, SG14 on the processing and validation of intermediate energy evaluated data files, goes one step further. The nuclear data files that have been created with the aforementioned information need to be processed and validated in order to be applicable in realistic intermediate energy simulations. We emphasize that the work of SG14 excludes the 0-20 MeV data part of the neutron evaluations, which is supposed to be covered elsewhere. This final report contains the following sections: section 2: a survey of the data files above 20 MeV that have been considered for validation in SG14; section 3: a summary of the review of the 150 MeV intermediate energy data files for ENDF/B-VI and, more briefly, the other libraries; section 4: validation of the data library against an integral experiment with MCNPX; section 5: conclusions. (author)

  15. An improved intermediate resonance method for heterogeneous media

    International Nuclear Information System (INIS)

    Chiovato, O.; Corno, S.; Pasquantonio, F.Di.

    1977-01-01

    A new formulation is described of the Intermediate Resonance method which incorporates the previous developments suitably modified and improved, together with some new contributions. The 'intermediate' character is directly introduced in the integral operator K, allowing a more rigorous deduction of the equations for evaluating the intermediate parameters related to the nuclides involved in the system. There is no limit to the number of internal (admixed in the fuel) and external moderators. The capability to take into account the interference scattering has been extended to heterogeneous systems. The Doppler broadening is described by means of new accurate rational approximations to the broadened line shape psi. Finally the use of energy mean values suitably defined refines the values of the resonance integrals and resonance absorption cross sections. The Intermediate Resonance method so extended and improved, has been coded in a group of FORTRAN routines, which have been inserted as a calculation option in the fast section of the GGC code for the evaluation of multigroup cross sections. A series of calculations has been carried out, using these routines, and comparisons have been made with Monte Carlo and Nordheim's methods. The results obtained show that the Intermediate Resonance method developed in the present work offers considerable advantages over Nordheim's method: better accuracy in evaluating resonance absorption cross sections, and much smaller computing times. (author)

  16. Convergent synthesis of a tetrasaccharide repeating unit of the O-specific polysaccharide from the cell wall lipopolysaccharide of Azospirillum brasilense strain Sp7

    Directory of Open Access Journals (Sweden)

    Pintu Kumar Mandal

    2014-01-01

    Full Text Available A straightforward convergent synthesis has been carried out for the tetrasaccharide repeating unit of the O-specific cell wall lipopolysaccharide of the strain Sp7 of Azospirillum brasilense. The target tetrasaccharide has been synthesized from suitably protected monosaccharide intermediates in 42% overall yield in seven steps by using a [2 + 2] block glycosylation approach.

  17. Synthesis of [14α, 15α-3H]-17α-cyanomethyl-17β-hydroxyestra-4.9-diene-3-one - a specifically tritium labelled gestagen

    International Nuclear Information System (INIS)

    Roemer, J.; Wagner, H.

    1978-05-01

    Synthesis of [14α, 15α- 3 H 2 ]-17α-cyanomethyl-17β-hydroxyestra-4.9-diene-3-one from quantitativly tritiated [14α, 15α- 3 H 2 ]-3-methoxyestra-1,3,5(10),8-tetraene-17β-ol is described. The determination of the radiochemical purity and chemical yield was carried out by thin-layer chromatography. Preparative thin-layer chromatography was used for purifying the final product. By-products formed in the course of synthesis could be detected by determining and comparing specific activities of the intermediate products. Radiolytic investigations revealed the instability of the tritium labelled dienone system. (author)

  18. Advances in heterocycle synthesis via [3+m]-cycloaddition reactions involving an azaoxyallyl cation as the key intermediate.

    Science.gov (United States)

    Xuan, Jun; Cao, Xia; Cheng, Xiao

    2018-05-17

    Heterocyclic compounds are widely found in many natural isolates and medicinally relevant compounds, as well as some fine chemicals. The development of general and efficient methods for the construction of heterocyclic compounds is one of the most important tasks in synthetic organic chemistry. Along these lines, [3+m]-cycloaddition reactions involving in situ generated azaoxyallyl cations as the 3-atom units have emerged as a powerful method for the synthesis of nitrogen-containing heterocycles. In this feature article, we highlight recent advances in this rapidly growing area, mainly focusing on the reaction design as well as the reaction mechanism.

  19. Synthesis of some new thiophene and thiopyrimidine compounds of expected anticancer activity and studying the augmenting effect of gamma radiation

    International Nuclear Information System (INIS)

    Zaher, N.H.M.

    2010-01-01

    The present investigation comprises a survey on the synthesis of, thiophene, thieno[2,3-d]pyrimidines, triazolothieno[2,3-d]-pyrimidines, thiadiazolothieno[2,3-d]pyrimidines. The thesis involves the synthesis of the following reported starting and intermediate compounds needed for the synthesis of the new intermediates and final compounds: Diethyl 5-amino-3-methylthiophene-2,4-dicarboxylate (I).+ Diethyl-5-isothiocyanato-3-methylthiophene-2,4-dicarboxylate (II) Diethyl 5-(hydrazinecarbothioamido)-3-methylthiophene-2,4- dicarboxylate (XI). Potassium 3-amino-6-(ethoxycarbonyl)-5-methyl-4-oxo-3,4- dihydrothieno[2,3-d]pyrimidine-2-thiolate (XII). .. Ethyl 3-amino-5-methyl-4-oxo-2-sulfanyl-1,2,3,4-tetrahydrothieno[ 2,3-d]pyrimidine-6-carboxylate (XIII) Ethyl 5-amino-4-cyano-3-methylthiophene-2-carboxylate (XXV). Diethyl 5-isothiocyanato-3-methylthiophene-2,4-dicarboxylate (II) was synthesized by thiophosogenation of diethyl 5-amino-3-methylthiophene- 2,4-dicarboxylate (I). Ethyl 3-amino-5-methyl-4-oxo-2-sulfanyl-1,2,3,4-tetrahydrothieno[ 2,3-d]pyrimidine-6-carboxylate (XIII) was prepared by reacting (II) with hydrazine hydrate in dichloromethane at room temperature. The new potassium salt (XII) was obtained by heating diethyl 5-(hydrazinecarbothioamido)- 3-methylthiophene-2,4-dicarboxylate (XI) in an ethanolic potassium hydroxide solution. Acidification of an aqueous solution of potassium 3-amino-6-(ethoxycarbonyl)-5-methyl-4-oxo-3,4- dihydrothieno[2,3-d]pyrimidine-2-thiolate (XII) gave the sulfanyl-Namino substituted thienopyrimidine compound (XIII). Ethyl 5-amino-4-cyano-3-methylthiophene-2-carboxylate (XXV) was synthesized by the reaction of ethylacetoacetate, sulfur, malononitrile and diethylamine in ethanol stirred in ice bath. Ethyl 4-cyano-5- ethoxymethylene amino-3-methylthiophene-2-carboxylate, (XXVI) a VI new intermediate was obtained upon the nucleophilic reaction of (XXV) with triethylorthoformate in acetic anhydride. The reaction of (XXVI) with hydrazine

  20. Aspects of 6-[18F]fluoro-L-DOPA preparation: precursor synthesis, preparative HPLC purification and determination of radiochemical purity

    International Nuclear Information System (INIS)

    Fuechtner, F.; Angelberger, P.; Kvaternik, H.; Hammerschmidt, F.; Simovc, B. Peric; Steinbach, J.

    2002-01-01

    A modified method for the synthesis of the intermediate product N-Boc-3,4-di(Boc-O)-6-iodo-L-phenylalanine ethyl ester of the [ 18 F]FDOPA precursor preparation was developed. With the application of bis-(trifluoroacetoxy)-iodobenzene for the iodination step with elemental iodine the yield of the intermediate can be increased from 12% to 50-60%. By replacing silica-gel-based RP HPLC column by a polymer-based column for semi-preparative purification of [ 18 F]FDOPA from the reaction mixture the radiochemical purity of the final product can be increased up to >99%. For the determination of the radiochemical impurity [ 18 F]fluoride a HPLC method using a column with polymer-based RP material was introduced

  1. Synthesis And Characterization Of Mebrofenin For Hepatobiliary Imaging

    International Nuclear Information System (INIS)

    Purwoko; Tamat, Swasono R.; Yunita, Fitri; Kristanti, Eti

    2003-01-01

    Mebrofenin labeled with Technetium-99m is a new radiopharmaceutical having superior and ideal characteristic as a hepatobiliary-imaging agent. The synthesis and characterization of Mebrofenin (3-Bromo-2,4,6-trimethyl acetanilido iminodiacetic acid) as IDA derivative has been carried out involving three steps of reaction i.e. : acetyllization of 2,4,6-Trimethyl aniline to get 2,4,6-trimethyl chloro acetanilide which upon bromination gives the intermediate bromotrimethyl derivative and [mally by nucleophilic substitution this intermediate product with iminodiacetic acid (IDA) gives mebrofenin. The acetylation and bromination reactions were carried out in acetic acid condition while the substitution was carried out by reflux for 5 hours in ethanol and water adjusted at pH 11. The ethanol was then removed under low pressure, and the unreacted compound was removed by filtration. The filtrate was adjusted to pH 2 - 2.5, and the resulting mebrofenin was isolated by filtration and recrystallized 3 times in ethanol. Characterization of the mebrofenin product was performed by observing its melting point (197-l99 o C), ultra violet and infra red spectra as well as mass spectrometric and high performance liquid chromatographic analysis. The results showed that the product was highly pure and the yield was around 20%

  2. A new ecologically friendly process for the synthesis of selective flotation reagents

    Directory of Open Access Journals (Sweden)

    Aleksandar D. Marinković

    2009-10-01

    Full Text Available A new ecologically friendly synthesis of N-alkyl-O-ethylthioncarbamates from ethyl dixanthogenates, waste material from the xanthate production plant, and monoalkylamines has been performed in this work. Structure determination of the synthesized compounds and also corresponding intermediates has been performed by IR, 1H-NMR and MS spectrometric methods. Residual dixanthogenates and thioncarbamates in waste water have been done by the gas chromatographic method and corresponding standard curve. It was confirmed that the reaction product was not present in water, while the concentration of dixanthogenates has been determined to be under the maximum contamination limit.

  3. The impact of cofactors and inhibitors on DNA repair synthesis after γ-irradiation in semi-permeable Escherichia coli cells

    International Nuclear Information System (INIS)

    Gaertner, C.

    1981-01-01

    The DNA-repair synthesis in tuluol-permeable E. coli cells after γ-irradiation has been investigated in dependence on the co-facotrs. ATB and NAD by means of enzyme kinetics. A partly repair-deficient mutants were taken into consideration which are well characterized in view of molecular biology; they showed which enzyme functions participate in the γ-induced DNA repair synthesis. The inhibition of the DNA-repair synthesis by the intercalary substances Adriamycin and Proflavin has been described and compared with the survival rates after irradiation and after combined treatment by irradiation and intercalary agents. (orig./AJ) [de

  4. Two-directional synthesis as a tool for diversity-oriented synthesis: Synthesis of alkaloid scaffolds

    Directory of Open Access Journals (Sweden)

    Kieron M. G. O’Connell

    2012-06-01

    Full Text Available Two-directional synthesis represents an ideal strategy for the rapid elaboration of simple starting materials and their subsequent transformation into complex molecular architectures. As such, it is becoming recognised as an enabling technology for diversity-oriented synthesis. Herein, we provide a thorough account of our work combining two-directional synthesis with diversity-oriented synthesis, with particular reference to the synthesis of polycyclic alkaloid scaffolds.

  5. Synthesis of acetylenic derivatives of hydroxynaphthoquinone

    International Nuclear Information System (INIS)

    Sanchez Kopper, Andres

    2010-01-01

    The acetylene derivatives synthesis 2-hydroxy-1 ,4-naphthoquinones was studied using different reaction conditions: coupling with copper and silver acetylides, Sonogashira reaction with and without CU (I) as cocatalyst. The reaction conditions are optimized for coupling of iodine lawson and ylide phenyl lawsone of iodine with various terminal acetylenes: phenyl acetylene, propargyl alcohol, 1-heptin and 2-methyl-3-butyne-2-ol. Also, reactants such as bromides of hidroxinaphthoquinones were used with protecting groups such as acetate, methoxy, phenyloxy, benzyloxy and tricloroetoxy. The synthesis of 2-hydroxy-3-(3-hydroxy-3-ynyl-1-methylbutane)-1,4-naphthoquinone, 2-methoxy-3-(2-phenylethynyl) -1,4-naphthoquinone and 2-(2-phenylethynyl)-3-(2,2,2-tricloroetoxy)-1,4-naphthoquinone was performed with rates of return of 22%, 57% and 67% respectively. The reaction of the yodolawsona was obtained with 3-chloro-3-methyl-1-butyne in the presence of CuI, CsI and Cs 2 Co 3 obtaining the enol ether: 3,3-dimethyl-2-methyl-2 ,3-dihydronaphto [2 ,3-b]furan-4,9-dione (dehydro-α-dunion), with a rate of return of 58%. This enol ether was used as a reactant for the formation, through a regioselective hydrogenation with PtO 2 /t-butanol of α-dunion with a yield of 50%. Furthermore, by acid hydrolysis with H 2 SO 4 has been possible to obtain a percentage yield of 75% streptocarpone. Both, α-dunion and streptocarpone, natural products extracted from Streptocarpus dunni shrub, with antiparasitic activity, and which so far had not presented an efficient synthesis. A mechanism is proposed for the reaction of formation of the enol ether where it is presumed the presence of a zwitterion-vinyl carbene as key intermediate of the reaction. All products were characterized by spectroscopy 1 H and 13 C-NMR, UV-Vis and IR. (author) [es

  6. The management of intermediate level wastes in Sweden

    International Nuclear Information System (INIS)

    Hultgren, Aa.; Thegerstroem, C.

    1980-01-01

    A brief overview of current practices and research in Sweden on the management of intermediate level wastes is given. Intermediate level wastes include spent resins, filters and core components from the six power reactors in operation; radioactive wastes from nuclear fuel development at Studsvik and from non-nuclear applications are a minor contribution. (Auth.)

  7. Preliminary thermal sizing of intermediate heat exchanger for NHDD system

    International Nuclear Information System (INIS)

    Kim, Chan Soo; Hong, Sung Deok; Kim, Yong Wan; Chang, Jongh Wa

    2009-01-01

    Nuclear Hydrogen Development and Demonstration (NHDD) system is a Very High Temperature gascooled Reactor (VHTR) coupled with hydrogen production systems. Intermediate heat exchanger transfers heat from the nuclear reactor to the hydrogen production system. This study presented the sensitivity analysis on a preliminary thermal sizing of the intermediate heat exchanger. Printed Circuit Heat Exchanger (PCHE) was selected for the thermal sizing because the printed circuit heat exchanger has the largest compactness among the heat exchanger types. The analysis was performed to estimate the effect of key parameters including the operating condition of the intermediate system, the geometrical factors of the PCHE, and the working fluid of the intermediate system.

  8. Intermediate mass distribution of the dual resonance pomeron

    International Nuclear Information System (INIS)

    Chiu, C.B.; Matsuda, S.

    1978-01-01

    The intermediate mass distribution of the dual resonance pomeron is determined at the one-loop level and it is shown that the mass distribution obtained is remarkably similar to a suitably defined mass distribution in the dual multiperipheral model. Thus it is suggestive to identify the intermediate states of the dual resonance pomeron with multiperipheral processes. (Auth.)

  9. CONDITIONING OF INTERMEDIATE-LEVEL WASTE AT FORSCHUNGSZENTRUM JUELICH GMBH

    International Nuclear Information System (INIS)

    Krumbach, H.

    2003-01-01

    This contribution to the group of low-level, intermediate, mixed and hazardous waste describes the conditioning of intermediate-level mixed waste (dose rate above 10 mSv/h at the surface) from Research Centre Juelich (FZJ). Conditioning of the waste by supercompaction is performed at Research Centre Karlsruhe (FZK). The waste described is radioactive waste arising from research at Juelich. This waste includes specimens and objects from irradiation experiments in the research reactors Merlin (FRJ-1) and Dido (FRJ-2) at FZJ. In principle, radioactive waste at Forschungszentrum Juelich GmbH is differentiated by the surface dose rate at the waste package. Up to a surface dose rate of 10 mSv/h, the waste is regarded as low-level. The radioactive waste described here has a surface dose rate above 10 mSv/h. Waste up to 10 mSv/h is conditioned at the Juelich site according to different conditioning methods. The intermediate-level waste can only be conditioned by supercompaction in the processing facility for intermediate-level waste from plant operation at Research Centre Karlsruhe. Research Centre Juelich also uses this waste cell to condition its intermediate-level waste from plant operation

  10. Proceedings of the Topical Meeting on the safety of nuclear fuel cycle intermediate storage facilities

    International Nuclear Information System (INIS)

    1998-01-01

    The CSNI Working Group on Fuel Cycle Safety held an International Topical Meeting on safety aspects of Intermediate Storage Facilities in Newby Bridge, England, from 28 to 30 October 1997. The main purpose of the meeting was to provide a forum for the exchange of information on the technical issues on the safety of nuclear fuel cycle facilities (intermediate storage). Titles of the papers are: An international view on the safety challenges to interim storage of spent fuel. Interim storage of intermediate and high-level waste in Belgium: a description and safety aspects. Encapsulated intermediate level waste product stores at Sellafield. Safety of interim storage facilities of spent fuel: the international dimension and the IAEA's activities. Reprocessing of irradiated fuel and radwaste conditioning at Belgoprocess site: an overview. Retrieval of wastes from interim storage silos at Sellafield. Outline of the fire and explosion of the bituminization facility and the activities of the investigation committee (STAIJAERI). The fire and explosion incident of the bituminization facility and the lessons learned from the incident. Study on the scenario of the fire incident and related analysis. Study on the scenario of the explosion incident and related analysis. Accident investigation board report on the May 14, 1997 chemical explosion at the plutonium reclamation facility, Hanford site, Richland, Washington. Dry interim storage of spent nuclear fuel elements in Germany. Safe and effective system for the bulk receipt and storage of light water reactor fuel prior to reprocessing. Receiving and storage of glass canisters at vitrified waste storage center of Japan Nuclear Fuel Ltd. Design and operational experience of dry cask storage systems. Sellafield MOX plant; Plant safety design (BNFL). The assessment of fault studies for intermediate term waste storage facilities within the UK nuclear regulatory regime. Non-active and active commissioning of the thermal oxide

  11. Supersymmetry and intermediate symmetry breaking in SO(10) superunification

    International Nuclear Information System (INIS)

    Asatryan, H.M.; Ioannisyan, A.N.

    1985-01-01

    A scheme of simultaneous breakdown of intermediate symmetry SO(10) → SU(3)sub(c) x U(1) x SU(2)sub(L) x SU(2)sub(R) and supersymmetry by means of a single scale parameter is suggested. This intermediate symmetry, which is preferable physically, owing to the broken supersymmetry has a minimum lying lower than SU(4) x SU(2)sub(L) x SU(2)sub(R). The intermediate symmetry is broken by the vacuum expectation value of the Higgs superfields. Owing to the quantum corrections the potential minimum turns out to correspond to breakdown of the intermediate symmetry up to the standard group SU(3)sub(c) x SU(2)sub(L) x U(1)sub(y). The value of the Weinberg angle is less than that in the supersymmetric SU(5) model and agrees with the experiment

  12. An evidence synthesis of the international knowledge base for new care models to inform and mobilise knowledge for multispecialty community providers (MCPs).

    Science.gov (United States)

    Turner, Alison; Mulla, Abeda; Booth, Andrew; Aldridge, Shiona; Stevens, Sharon; Battye, Fraser; Spilsbury, Peter

    2016-10-01

    NHS England's Five Year Forward View (NHS England, Five Year Forward View, 2014) formally introduced a strategy for new models of care driven by simultaneous pressures to contain costs, improve care and deliver services closer to home through integrated models. This synthesis focuses on a multispecialty community provider (MCP) model. This new model of care seeks to overcome the limitations in current models of care, often based around single condition-focused pathways, in contrast to patient-focused delivery (Royal College of General Practitioners, The 2022 GP: compendium of evidence, 2012) which offers greater continuity of care in recognition of complex needs and multimorbidity. The synthesis, an innovative combination of best fit framework synthesis and realist synthesis, will develop a "blueprint" which articulates how and why MCP models work, to inform design of future iterations of the MCP model. A systematic search will be conducted to identify research and practice-derived evidence to achieve a balance that captures the historical legacy of MCP models but focuses on contemporary evidence. Sources will include bibliographic databases including MEDLINE, PreMEDLINE, CINAHL, Embase, HMIC and Cochrane Library; and grey literature sources. The Best Fit synthesis methodology will be combined with a synthesis following realist principles which are particularly suited to exploring what works, when, for whom and in what circumstances. The aim of this synthesis is to provide decision makers in health and social care with a practical evidence base relating to the multispecialty community provider (MCP) model of care. PROSPERO CRD42016039552 .

  13. A short designed semi-aromatic organic nanotube – synthesis, chiroptical characterization, and host properties

    DEFF Research Database (Denmark)

    Wixe, Torbjörn; Christensen, Niels Johan; Lidin, Sven

    2014-01-01

    to molecular dynamics simulations in chloroform). The synthesis of the tube, a heptamer, is based on a series of Friedländer condensations and the use of pyrido[3,2-d]pyrimidine units as masked 2-amino aldehydes, as a general means to propagate organic tubular structures and the introduction of a methoxy group...... for modification toward solubility and functionalization are described. The electronic CD spectra of the tube and molecular intermediates are correlated with theoretical spectra calculated with time-dependent density functional theory to characterize the chirality of the tube. Both experimental (NMR...

  14. Highly Atom Economic Synthesis of d?2?Aminobutyric Acid through an In?Vitro Tri?enzymatic Catalytic System

    OpenAIRE

    Chen, Xi; Cui, Yunfeng; Cheng, Xinkuan; Feng, Jinhui; Wu, Qiaqing; Zhu, Dunming

    2017-01-01

    Abstract d?2?Aminobutyric acid is an unnatural amino acid serving as an important intermediate in pharmaceutical production. Developing a synthetic method that uses cheaper starting materials and produces less by?product is a pressing demand. A tri?enzymatic catalytic system, which is composed of l?threonine ammonia lyase (l?TAL), d?amino acid dehydrogenase (d?AADH), and formate dehydrogenase (FDH), has thus been developed for the synthesis of d?2?aminobutyric acid with high optical purity. I...

  15. Tube sheet structural analysis of intermediate heat exchanger for fast breeder reactor 'Monju'

    International Nuclear Information System (INIS)

    Nakagawa, Y.; Ueno, T.; Fukuda, Y.; Ichimiya, M.

    1983-01-01

    The Prototype Fast Breeder Reactor 'Monju' is the first power generating fast breeder reactor in Japan. We have been designing the components of the plant for manufacturing. Among these is the intermediate heat exchanger (IHX) which exchanges heat between primary and secondary sodium loop. The tube sheet of IHX (shell to ligament junction) is a difficult area from the view point of structural strength design under elevated temperature. To validate the structural integrity of tube sheet we performed the series of inelastic analysis and tube sheet thermal shock test using test pieces and half scale model of actual design. The results of inelastic analyses showed there is little progressive deformation around shell to ligament structural discontinuous junction. Furthermore, thermal shock tests showed no increase of an accumulative deformation. By these analyses and experiments, structural reliability of tube sheet could be shown. (author)

  16. Inhibition and recovery of the rate of DNA synthesis in V79 Chinese hamster cells following ultraviolet light irradiation

    International Nuclear Information System (INIS)

    Ventura, A.M.; Meneghini, R.

    1984-01-01

    Chinese hamster fibroblasts (V79 cell line) exhibit the phenomenon of recovery of DNA synthesis from the initial inhibition observed after ultraviolet light irradiation, in the absence of significant excision of pyrimidine dimers. In an attempt to determine whether the initial inhibition and subsequent recovery can be accounted for by parallel variations in the rate of movement of the replication fork, the cells were pulse-labeled with radioactive bromodeoxyuridine at different times following irradiation and their DNA centrifuged in neutral CsCl density gradients. When DNA synthesis inhibition was at a maximum, an accumulation of DNA, of density intermediate between hybrid and nonsubstituted DNA, was noticed in the density-distribution profiles. The density distribution of DNA along the gradient can provide an estimate of the rate of movement of the replication fork, and the results indicate that most of the variation in the overall rate of DNA synthesis can be accounted for by a parallel variation in the rate of fork movement. (Auth.)

  17. Molecular mechanism of reduction in pregnenolone synthesis by cigarette smoke

    International Nuclear Information System (INIS)

    Bose, Mahuya; Whittal, Randy M.; Gairola, C. Gary; Bose, Himangshu S.

    2008-01-01

    Steroidogenic acute regulatory protein (StAR) facilitates the movement of cholesterol from the outer to inner mitochondrial membrane for the synthesis of pregnenolone. Here, we investigated the molecular mechanism of the reduction of pregnenolone synthesis by cigarette smoke condensate (CSC). Pre-exposure or post-exposure of cells with CSC led to reduced pregnenolone synthesis, in a fashion similar to its effect on isolated mitochondria. However, there was no difference in the expression of 30 kDa StAR in cells treated with moderately concentrated CSC by either regimen. The active form of 37 kDa StAR is degraded easily suggesting that the continuous presence of CSC reduces StAR expression. Mitochondrial import of 35 S-methionine-labeled StAR followed by extraction of the StAR-mitochondrial complex with 1% digitonin showed similarly sized complexes in the CSC-treated and untreated mitochondria. Further analysis by sucrose density gradient centrifugation showed a specific complex, 'complex 2', in the untreated mitochondria but absent in the CSC-treated mitochondria. Mass spectrometric analysis revealed that complex 2 is the outer mitochondrial protein, VDAC1. Knockdown of VDAC1 expression by siRNA followed by co-transfection with StAR resulted in a lack of pregnenolone synthesis and 37 kDa StAR expression with reduced expression of the intermediate, 32 kDa StAR. Taken together, these results suggest that in the absence of VDAC1, active StAR expression is reduced indicating that VDAC1 expression is essential for StAR activity. In the absence of VDAC1-StAR interaction, cholesterol cannot be transported into mitochondria; thus the interaction with VDAC1 is a mandatory step for initiating steroidogenesis

  18. Features of the Synthesis of Performance Security Information in Computer Systems

    Directory of Open Access Journals (Sweden)

    V. K. Dzhogan

    2011-12-01

    Full Text Available Synthesis of a scorecard is a gradual process of composition, since the set of elements that reflect the original, systematized their condition, and, through a series of intermediates, linking them in a single bound to the structure ends with one element that reflects the purpose of the system. The hierarchical structure of the system performance of information security in computer systems is a structure with regard to “one to many”. The article reflects the extent of information security tools capabilities influence at the security of information resources of computer systems (from indirect — Class 1, to direct — Class 4.

  19. Enhanced Synthesis of Alkyl Amino Acids in Miller's 1958 H2S Experiment

    Science.gov (United States)

    Parker, Eric T.; Cleaves, H. James; Callahan, Michael P.; Dworkin, James P.; Glavin, Daniel P.; Lazcano, Antonio; Bada, Jeffrey L.

    2011-01-01

    Stanley Miller's 1958 H2S-containing experiment, which included a simulated prebiotic atmosphere of methane (CH4), ammonia (NH3), carbon dioxide (CO2), and hydrogen sulfide (H2S) produced several alkyl amino acids, including the alpha-, beta-, and gamma-isomers of aminobutyric acid (ABA) in greater relative yields than had previously been reported from his spark discharge experiments. In the presence of H2S, aspariic and glutamic acids could yield alkyl amino acids via the formation of thioimide intermediates. Radical chemistry initiated by passing H2S through a spark discharge could have also enhanced alkyl amino acid synthesis by generating alkyl radicals that can help form the aldehyde and ketone precursors to these amino acids. We propose mechanisms that may have influenced the synthesis of certain amino acids in localized environments rich in H2S and lightning discharges, similar to conditions near volcanic systems on the early Earth, thus contributing to the prebiotic chemical inventory of the primordial Earth.

  20. A facile route towards the synthesis of 2-(1H-indol-3-yl)-acetamides using 1,1-carbonyldiimidazole

    International Nuclear Information System (INIS)

    Kanwal, F.; Khan, K.M.; Fatima, B.; Bano, B.; Salar, U.

    2016-01-01

    A base-catalyzed one pot reaction has been developed for the synthesis of 2-(1H-indol-3-yl)-acetamides via coupling of 1,1-carbonyldiimidazole with 2-(1H-indol-3-yl) acetic acid resulting in the formation of a reactive intermediate which on treatment with different substituted anilines afford 2-(1H-indol-3-yl)-acetamides in good yield. The use of base along with coupling reagent eases the formation of intermediate in minimum time. All the synthetic compounds were obtained in good to moderate yields, the use of various substituted anilines effects the yields of the products. Compounds 4-30 were synthesized and the structures of all the synthetic compounds were determined by using spectroscopic techniques such as 1H-, 13C-NMR, EIMS and HRMS. (author)