Academic literature on the topic 'S-H Bond Study'
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Journal articles on the topic "S-H Bond Study"
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Munshi, Parthapratim, Tejender S. Thakur, Tayur N. Guru Row, and Gautam R. Desiraju. "Five varieties of hydrogen bond in 1-formyl-3-thiosemicarbazide: an electron density study." Acta Crystallographica Section B Structural Science 62, no. 1 (January 17, 2006): 118–27. http://dx.doi.org/10.1107/s0108768105033689.
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In an attempt to investigate the putative S—H...N hydrogen bond, we have studied the title compound, 1-formyl-3-thiosemicarbazide, which was revealed in a CSD search as a crystal structure which might show such an interaction. However, a redetermination of the structure at room temperature and careful analysis showed that the earlier study [Saxena et al. (1991). Acta Cryst. C47, 2374–2376] on which the CSD search was based was in error and that the possibility of an S—H...N hydrogen bond is negated. The presence of five other varieties of hydrogen bond (N—H...O, N—H...S, N—H...N, C—H...O, C—H...S) in the crystal packing prompted us to redirect our efforts and to undertake a study of the charge-density distribution at 90 K. The topological analysis of these five varieties of hydrogen bond was carried out with Bader's quantum theory of `atoms in molecules' and by applying Koch–Popelier's criteria. The analysis reveals that the hydrogen-bond strength is highest for N—H...O and lowest for C—H...S with N—H...S, N—H...N and C—H...O forming the middle order.
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Kohli, Ruchi, and Rupinder Preet Kaur. "A Theoretical Study of Hydrogen-Bonded Complexes of Ethylene Glycol, Thioglycol and Dithioglycol with Water." Asian Journal of Chemistry 34, no. 1 (2021): 169–82. http://dx.doi.org/10.14233/ajchem.2022.23487.
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In the present study, a theoretical analysis of hydrogen bond formation of ethylene glycol, thioglycol, dithioglycol with single water molecule has been performed based on structural parameters of optimized geometries, interaction energies, deformation energies, orbital analysis and charge transfer. ab initio molecular orbital theory (MP2) method in conjunction with 6-31+G* basis set has been employed. Twelve aggregates of the selected molecules with water have been optimized at MP2/6-31+G* level and analyzed for intramolecular and intermolecular hydrogen bond interactions. The evaluated interaction energies suggest aggregates have hydrogen bonds of weak to moderate strength. Although the aggregates are primarily stabilized by conventional hydrogen bond donors and acceptors, yet C-H···O, S-H···O, O-H···S, etc. untraditional hydrogen bonds also contribute to stabilize many aggregates. The hydrogen bonding involving sulfur in the aggregates of thioglycol and dithioglycol is disfavoured electrostatically but favoured by charge transfer. Natural bond orbital (NBO) analysis has been employed to understand the role of electron delocalizations, bond polarizations, charge transfer, etc. as contributors to stabilization energy.
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Wood, Peter A., Elna Pidcock, and Frank H. Allen. "Interaction geometries and energies of hydrogen bonds to C=O and C=S acceptors: a comparative study." Acta Crystallographica Section B Structural Science 64, no. 4 (July 10, 2008): 491–96. http://dx.doi.org/10.1107/s0108768108015437.
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The occurrence, geometries and energies of hydrogen bonds from N—H and O—H donors to the S acceptors of thiourea derivatives, thioamides and thiones are compared with data for their O analogues – ureas, amides and ketones. Geometrical data derived from the Cambridge Structural Database indicate that hydrogen bonds to the C=S acceptors are much weaker than those to their C=O counterparts: van der Waals normalized hydrogen bonds to O are shorter than those to S by ∼ 0.25 Å. Further, the directionality of the approach of the hydrogen bond with respect to S, defined by the C=S...H angle, is in the range 102–109°, much lower than the analogous C=O...H angle which lies in the range 127–140°. Ab initio calculations using intermolecular perturbation theory show good agreement with the experimental results: the differences in hydrogen-bond directionality are closely reproduced, and the interaction energies of hydrogen bonds to S are consistently weaker than those to O, by ∼ 12 kJ mol−1, for each of the three compound classes. There are no CSD examples of hydrogen bonds to aliphatic thiones, (Csp 3)2C=S, consistent with the near-equality of the electronegativities of C and S. Thioureas and thioamides have electron-rich N substituents replacing the Csp 3 atoms. Electron delocalization involving C=S and the N lone pairs then induces a significant >Cδ+=Sδ− dipole, which enables the formation of the medium-strength C=S...H bonds observed in thioureas and thioamides.
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Nowroozi, A., H. Roohi, M. Poorsargol, P. Mohammadzadeh Jahani, H. Hajiabadi, and H. Raissi. "NH···S and SH···N intramolecular hydrogen bond in β-thioaminoacrolein: A quantum chemical study." International Journal of Quantum Chemistry 111, no. 12 (June 10, 2010): 3008–16. http://dx.doi.org/10.1002/qua.22615.
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Steiner, T. "Hydrogen-Bond Distances to Halide Ions in Organic and Organometallic Crystal Structures: Up-to-date Database Study." Acta Crystallographica Section B Structural Science 54, no. 4 (August 1, 1998): 456–63. http://dx.doi.org/10.1107/s0108768197014821.
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Geometrical data on hydrogen bonds to halide ions are compiled from the currently available crystal structures. Hydrogen bonds from 25 donor types to fluoride, chloride, bromide and iodide ions are considered. Compared with earlier compilations, the increased data volume allows a finer subdivision of O—H and N—H donors, and the donors C—H, S—H and P—H can be included. For a given donor type, the hydrogen-bond distance typically increases by over 0.5 Å from fluoride to chloride, 0.15 Å from chloride to bromide and 0.25 Å from bromide to iodide acceptors. The strongest of the C—H donors considered, chloroform, forms hydrogen bonds with chloride ions with an average H...Cl separation of only 2.39 Å and an average C...Cl separation of 3.42 Å. The lengthening of the N—H covalent bond in hydrogen bonds to chloride ions is quantified from neutron diffraction data.
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Li, An Yong, Li Juan Cao, and Hong Bo Ji. "Theoretical study of H bonds of HArF and HF with isoelectronic systems N2, CO, and BF." Canadian Journal of Chemistry 88, no. 4 (April 2010): 352–61. http://dx.doi.org/10.1139/v10-004.
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The H bonds of HArF and HF with N2, CO, and BF were studied at the MP2(full)/6-311++G(2d, 2p) level. The results show that only the complexes WY···HArF (WY = N2, OC) and WY···HF (WY = N2, OC, FB) are stable, the H-bonding WY···HArF leads to contraction of the HAr bond with a concomitant frequency blue shift, but the H-bonding WY···HF causes the HF bond to elongate with a frequency red shift. A quantity P is defined to measure polarization of the HX bond; the H bonding causes the P value of the HX bond (X = Ar, F) to increase. The HX bond length change and frequency shift in the H-bonding WY···HArF and WY···HF are mainly caused by intermolecular hyperconjugation, n(Y) → σ*(HX) (X = Ar, F), where electrostatic interaction has only a small contribution. In HArF, the strong intramolecular hyperconjugation, n(F) → σ*(HAr), can adjust electron density on σ*(HAr); upon formation of H bonding, the HAr stretching frequency blue shift is caused by a decrease of intramolecular hyperconjugation and an increase of the s character of the Ar hybrid in the HAr bond, induced by the intermolecular hyperconjugation. In the H bonds of HF without intramolecular hyperconjugation, the intermolecular hyperconjugation, n(Y) → σ*(HF), leads to a red shift of the HF bond, although there is also large rehybridization.
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Yang, Yong. "Theoretical study of the SH···O blue-shifted hydrogen bond." International Journal of Quantum Chemistry 109, no. 2 (2009): 266–74. http://dx.doi.org/10.1002/qua.21691.
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Raissi, Heidar, Mehdi Yoosefian, Soheila Zamani, and Farzaneh Farzad. "Conformational study, molecular structure, and S…H‒N, S‒H…N intramolecular hydrogen bond in thioformyl-3-aminoacrylaldehyde." Journal of Sulfur Chemistry 33, no. 1 (November 28, 2011): 75–85. http://dx.doi.org/10.1080/17415993.2011.635793.
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Hützler, Wilhelm Maximilian, and Michael Bolte. "Five pseudopolymorphs of 6-amino-2-thiouracil: absence of N—H...S hydrogen bonds." Acta Crystallographica Section C Crystal Structure Communications 69, no. 1 (December 15, 2012): 93–100. http://dx.doi.org/10.1107/s010827011204930x.
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In order to study the preferred hydrogen-bonding pattern of 6-amino-2-thiouracil, C4H5N3OS, (I), crystallization experiments yielded five different pseudopolymorphs of (I), namely the dimethylformamide disolvate, C4H5N3OS·2C3H7NO, (Ia), the dimethylacetamide monosolvate, C4H5N3OS·C4H9NO, (Ib), the dimethylacetamide sesquisolvate, C4H5N3OS·1.5C4H9NO, (Ic), and two different 1-methylpyrrolidin-2-one sesquisolvates, C4H5N3OS·1.5C5H9NO, (Id) and (Ie). All structures containR21(6) N—H...O hydrogen-bond motifs. In the latter four structures, additionalR22(8) N—H...O hydrogen-bond motifs are present stabilizing homodimers of (I). No type of hydrogen bond other than N—H...O is observed. According to a search of the Cambridge Structural Database, most 2-thiouracil derivatives form homodimers stabilized by anR22(8) hydrogen-bonding pattern, with (i) only N—H...O, (ii) only N—H...S or (iii) alternating pairs of N—H...O and N—H...S hydrogen bonds.
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Kruszynski, Rafal. "Intermolecular interactions in 2,4-dinitrophenylhydrazine hydrochloride hydrate: X-ray structural and quantum mechanical study." Open Chemistry 6, no. 4 (December 1, 2008): 542–48. http://dx.doi.org/10.2478/s11532-008-0067-7.
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Abstract2,4-dinitrophenylhydrazine hydrochloride hydrate (I) was determined by X-ray crystallography, and the intermolecular interaction energies were calculated in terms of Natural Bond Orbital analysis. The asymmetric unit of (I) consists of a dinitrophenylhydrazinium cation, a chloride anion and a water molecule. The interatomic distances and angles in (I) show no unusual values. In the structure there are intermolecular N—H⊎⊎⊎O, N—H⊎⊎⊎Cl, O—H⊎⊎⊎Cl, C—H⊎⊎⊎O hydrogen bonds with bonding energy ranging form 16.03 to 0.76 kcal mol−1. These hydrogen bonds create the following N1 motifs: 6D, S(5), S(6), C(6), C(9). N1D motifs become infinite at the third level and are 2C 32(6), C 32(7).
Dissertations / Theses on the topic "S-H Bond Study"
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Nagarajan, V. "Study of some supramolecular assemblies mediated by N-H-O, N-H-N and N-H-S hydrogen bonds." Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2012. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2141.
Full textBooks on the topic "S-H Bond Study"
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Bartfeld, Sina, Hannah Schickl, Cantas Alev, Bon-Kyoung Koo, Anja Pichl, Angela Osterheider, and Lilian Marx-Stölting, eds. Organoide. Nomos Verlagsgesellschaft mbH & Co. KG, 2020. http://dx.doi.org/10.5771/9783748908326.
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Organoids are developed from stem cells and serve as three-dimensional model systems for different organs. They have great potential for research and medicine, but also raise philosophical, ethical and legal questions which have rarely been discussed in Germany so far. This thematic study by the interdisciplinary research group (IAG) Gene Technology Report at the Berlin-Brandenburg Academy of Sciences and Humanities offers an overview of current scientific developments, their present and potential application, as well as epistemological, ethical and legal reflections. Hereby, the IAG wants to provide impetus for an interdisciplinary and society-wide debate on this general subject. With contributions by Cantas Alev, Aileen-Diane Bamford, Sina Bartfeld, Andreia S. Batista-Rocha, Ali H. Brivanlou, Thomas Burgold, Cindrilla Chumduri, Stephan Clemens, Emrecan Dilmen, Tobias Erb, Fred Etoc, Melinda B. Fagan, Heiner Fangerau, Boris Fehse, Nina Frey, Tristan Frum, Anne Grapin-Botton, Navin Gupta, Jürgen Hampel, Ferdinand Hucho, Özge Kayisoglu, Rashmiparvathi Keshara, Yung Hae Kim, Bon-Kyoung Koo, Martin Korte, Yaroslav Koshelev, Kai Kretzschmar, Allison Lewis, Lilian Marx-Stölting, Fruzsina Molnár-Gábor, Ryuji Morizane, Stefan Mundlos, Paola Nicolas, Angela Osterheider, In-Hyun Park, Anja Pichl, Sandra Pilat-Carotta, Jens Reich, Marlen Reinschke, Hannah Schickl, Silke Schicktanz, Nicolas Schlegel, Jason R. Spence, Yoshiaki Tanaka, Jochen Taupitz, Isaree Teriyapirom, Margherita Y. Turco, Jörn Walter, Eva Winkler, Martin Zenke.
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Kopley, Emily. Virginia Woolf and Poetry. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780198850861.001.0001.
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Virginia Woolf’s career was shaped by her impression of the conflict between poetry and the novel, a conflict she often figured as one between masculine and feminine, old and new, bound and free. In large part for feminist reasons, Woolf promoted the triumph of the novel over poetry, even as she adapted some of poetry’s techniques for the novel in order to portray the inner life. Woolf considered poetry the rival form to the novel. A monograph on Woolf’s sense of generic rivalry thus offers a thorough reinterpretation of the motivations and aims of her canonical work. Drawing on unpublished archival material and little-known publications, the book combines biography, book history, formal analysis, genetic criticism, source study, and feminist literary history. Woolf’s attitude toward poetry is framed within contexts of wide scholarly interest: the decline of the lyric poem, the rise of the novel, the gendered associations with these two genres, elegy in prose and verse, and the history of English Studies. Written in clear and lively language, the book maintains a narrative drive as it traces Woolf’s reading and writing over her lifetime, including her response to poets and critics in her circle such as J. K. Stephen, Julian Bell, Vita Sackville-West, Sir Arthur Quiller-Couch, T. S. Eliot, Stephen Spender, and W. H. Auden. Virginia Woolf and Poetry makes three important contributions. It clarifies a major prompt for Woolf’s poetic prose. It exposes the generic rivalry that was creatively generative to many modernist writers. And it details how holding an ideology of a genre can shape literary debates and aesthetics.
Book chapters on the topic "S-H Bond Study"
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Mosebi, Salerwe. "Calorimetry to Quantify Protein-Ligand Binding." In Applications of Calorimetry [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.102959.
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Isothermal titration calorimetry (ITC) is the preferred method used to study biochemical reactions like protein-ligand binding due to its sensitivity, accuracy, and precision. ITC measures directly the heat absorbed or released (∆H) associated with a given binding process. A typical ITC experiment allows the dissection of the binding energy of a reaction into ligand-enzyme association constant (Ka), change in enthalpy (∆H), change in entropy (∆S), change in Gibbs-free energy (∆G), and the stoichiometry of association (N). The change in heat capacity (∆Cp) is obtained from the measurements of binding enthalpy over a range of temperatures. The magnitude and signs of the thermodynamic parameters that were obtained provide insight into the nature of interactions involved in the binding process. The strength of interaction is thermodynamically favorable is determined by the Gibbs free energy. ∆G is an important thermodynamic descriptor of a binding reaction since it dictates the binding affinity and is in turn defined by the enthalpy and entropy changes expressed in the following equation: ∆G = ∆H–T∆S. Up-close, this reflects the contradistinctions of two thermodynamic effects at a molecular level—the propensity to drop to lower energy (bond formation, negative ∆H), counterbalanced by the innate thermal Brownian motion’s destructive characteristic (bond breakage, positive ∆S).
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Jayawardene, Chula J. "Tripartite and Quadpartite Size Ramsey Numbers for All Pairs of Connected Graphs on Four Vertices." In Handbook of Research on Advanced Applications of Graph Theory in Modern Society, 251–66. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-5225-9380-5.ch010.
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A popular area of graph theory is based on a paper written in 1930 by F. P. Ramsey titled “On a Problem on Formal Logic.” A theorem which was proved in his paper triggered the study of modern Ramsey theory. However, his premature death at the young age of 26 hindered the development of this area of study at the initial stages. The balanced size multipartite Ramsey number mj (H,G) is defined as the smallest positive number s such that Kj×s→ (H,G). There are 36 pairs of (H, G), when H, G represent connected graphs on four vertices (as there are only 6 non-isomorphic connected graphs on four vertices). In this chapter, the authors find mj (H, G) exhaustively for all such pairs in the tripartite case j=3, and in the quadpartite case j=4, excluding the case m4 (K4,K4). In this case, the only known result is that m4 (K4,K4) is greater than or equal to 4, since no upper bound has been found as yet.
Conference papers on the topic "S-H Bond Study"
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Wu, Leyi, Jing Luo, and Huihui Guo. "An interactive design solution for prenatal emotional nursing of pregnant women." In 13th International Conference on Applied Human Factors and Ergonomics (AHFE 2022). AHFE International, 2022. http://dx.doi.org/10.54941/ahfe1001973.
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With the continuous development of interactive technology, informatization has begun to integrate into people's life[1].Having been neglected in history, postpartum depression reminds us that we need to pay attention to maternal emotional needs and prenatal care[2]. In the current situation, it is worth researching the interactive products for prenatal emotional care. According to the survey, it is not difficult to find that some speech emotion and facial expression recognition technologies in artificial intelligence are developing Which have large potential for extensive use.[3,4]. Therefore, it is necessary and feasible to design prenatal emotional diagnosis tools for pregnant women. This study has designed a product to care for pregnant women by identifying their emotional needs through AI recognition technologies. Appropriate prenatal intervention is conducive to the prevention of postpartum depression[5,6] . The use of artificial intelligence recognition technology can provide an appropriate emotional care plan. This can reduce the difficulty of training medical personnel and the difficulty of relatives caring for pregnant women. Therefore, the risk of postpartum depression can be reduced. QUESTIONCollecting opinions and information from previous studies is an important reference for this study. Therefore, this study needs to solve the following problems.1) How to design an artificial intelligence product that can accurately diagnose the emotion of pregnant women?2) How to integrate AI facial emotion recognition technology?3) How to help nurses and their families take care of users more professionally and easily through the information database?4) How to adapt the emotional care program provided by interactive products to different pregnant women? Methods:the research methods of this study are as follows:1) Observing the working process of artificial midwives and psychologists to find Which part can be assisted by machines[7].2) To understand the emotional needs of pregnant women through interview.3) To brainstorm according to the real data collected before and research findings, and then design interactive products that can practically solve the emotional care problems of pregnant women.4) Through the experiment of AI emotion recognition technologies, the feasibility of emotion recognition is verified. CONCLUSIONS:With the continuous development of artificial intelligence, more and more artificial intelligence products have entered our life [1]. This study is aimed to help pregnant women prevent prenatal and postpartum depression and maintain their health through artificial intelligence interaction technologies. This study is exploring the solution under the help of artificial intelligence after studying the problem that prenatal and postpartum emotion are neglected. This design is still in the conceptual design stage, but it seems only a matter of time before this design is applied in the future[8]. REFERENCES:[1]. Lee H S , Lee J . Applying Artificial Intelligence in Physical Education and Future Perspectives. 2021.[2]. Beck C T . Postpartum depression: it isn't just the blues.[J]. American Journal of Nursing, 2006, 106(5):40-50.[3].Ramakrishnan S , Emary I M M E . Speech emotion recognition approaches in human computer interaction[J]. Telecommunication Systems, 2013, 52(3):OnLine-First.[4]. Samara A , Galway L , Bond R , et al. Affective state detection via facial expression analysis within a human–computer interaction context[J]. Journal of Ambient Intelligence & Humanized Computing, 2017.[5]. Clatworthy J . The effectiveness of antenatal interventions to prevent postnatal depression in high-risk women[J]. Journal of Affective Disorders, 2012, 137(1-3):25-34.[6]. Ju C H , Hye K J , Jae L J . Antenatal Cognitive-behavioral Therapy for Prevention of Postpartum Depression: A Pilot Study[J]. Yonsei Medical Journal, 2008, 49(4):553-.[7]. Fletcher A , Murphy M , Leahy-Warren P . Midwives' experiences of caring for women's emotional and mental well-being during pregnancy[J]. Journal of Clinical Nursing, 2021.[8]. Jin X , Liu C , Xu T , et al. Artificial intelligence biosensors: Challenges and prospects[J]. Biosensors & Bioelectronics, 2020, 165:112412.
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Kooistra, T., J. A. van den Berg, H. A. M. Tüns, G. Platenburg, D. Rijken, and E. A. van den Berg. "BUTYRATE SPECIFICALLY STIMULATES TISSUE-TYPE PLASMINOGEN ACTIVATOR SYNTHESIS IN CULTURED HUMAN ENDOTHELIAL CELLS." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644656.
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In a search for compounds that can enhance tissue-type plasminogen activator (t-PA) synthesis in cultured human endothelial cells we found that dibutyryl cyclic AMP (at a concentration of 2 mM) led to a several-fold increase in t-PA production by endothelial cells over a 24 h incubation period. Further researchshowed that this stimulating effectcould be explained by the slow liberation of butyrate, as the effect could be reproduced by addition of free butyrate to the medium, but notby addition of 8-bromo cyclic AMP. With butyrate, an accelerated accumulation of t-PA antigen in the conditioned medium (CM) was observed after a lag period of about 6 h. Increasing amounts of butyrate caused anincreasingly stimulatory effect, reaching a plateau with 5 mM butyrate. The relative increase in t-PAproduction in thempresence of 5 mM butyrate varied among different endothelial cell cultures from 6 to 25-fold in 24 h CM. The butyrate-induced increase in t-PA production wasaccompanied by increased t-PA mRNAlevels.Analysis of radiolabelled CM andcell extracts by SDS-PAGE and autoradiography indicated that the potent action of butyrate is restricted to a limited group of proteins. We found that theaccumulation of PA-inhibitor activity in CM from butyrate-treated cells increased only moderately.In our study of the relationshipbetween structure and stimulatory activity we found that butyrate wasby far the most effective inducer oft-PA synthesis. Shortening or lengthening the carbon chain by one carbon atom decreased the stimulatory effect after 24 h of incubation by 50-70%. Further changes in the length of the carbon chain almost completely suppressed the stimulatory activity. Similarly, alterations of the aliphatic chain by introduction of functional groups, a double bond or a branched structure rendered butyrate ineffective in increasing t-PA synthesis. Thus, a straight-chain C4 monocarboxylate structure with a methyl group at one end and a carboxyl moiety at the other seems to be required for the rather specific induction of t-PA synthesis in cultured human endothelialcells.
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Berrettini, M., M. J. Heeb, and J. H. Griffin. "ISOLATION AND FUNCTIONAL PROPERTIES OF MONOMERIC BLOOD COAGULATION FACTOR XI." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1642803.
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To evaluate the significance of the normal dimeric structure (160,000 MW) of blood coagulation Factor XI (F.XI), a monomeric form (80,000 MW) was produced by mild reduction and alkylation of native F.XI. Since initial efforts to reduce and alkylate F.XI in solution inactivated the molecule, F.XI was bound to high MW kininogen (HMWK) to stabilize the native structure. Purified F.XI was bound to HMWK-Sepharose, and the column was washed for 2 h with 40 μM dithiothreitol in 4mM acetate buffer, 2mM EDTA, 1mM benzamidine, pH 7.8, and then for 2 h with 50 μM iodoacetamide in the same buffer. Elution with 0.5 M NaCl gave a preparation containing ∼ 85% F.XI monomer and ∼ 15% dimer, as judged by nonreduced SDS-PAGE and by gel filtration of the radiolabeled preparation. The monomeric F.XI preparation had only 10% of the clotting activity of dimeric F.XI (per mole of enzymatic site) as measured in APTT clotting assays using F.XI deficient plasma. After activation with β-Factor XIIa in solution, the monomer F.XIa preparation exhibited 85% of the clotting activity of native F.XIa in unactivated PTT assays using F.XI deficient plasma. In addition, when compared to native F.XIa, monomeric F.XIa gave 65% amidolytic activity against the substrate, S-2366, and 75% activity against Factor IX in assays of the release of the activation peptide from 3H-Factor IX. Polystyrene tubes were coated with HMWK then blocked with 1% BSA to study the binding of 125I-F.XI to HWMK. When the binding of the 125I-labeled preparations of monomeric and dimeric forms of F.XI to HMWK was studied, two distinct components were identified in the association of dimeric F.XI, one with high affinity (Kd ∼ 2.5 X 10-9M) and one with less affinity (Kd ∼ 1.7 X 10-8M), while the binding of monomeric F.XI occurred with a single low affinity component (Kd ∼ 1.1 X 10-8M). These observations suggest that the dimeric structure of F.XI is required for efficient binding of the molecule to HMWK and for normal activation by the contact activation system in plasma, but that the dimeric structure of F.XIa does not play a role in the expression of the enzymatic activity against Factor IX in fluid phase.
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Mokdad, Mohamed, Bouhafs Mebarki, Mourad Semmani, and Shaikha Aljunaidi. "Volunteering at the Foggara work in Touat region: A study in Social ergonomics." In 13th International Conference on Applied Human Factors and Ergonomics (AHFE 2022). AHFE International, 2022. http://dx.doi.org/10.54941/ahfe1002664.
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Background:It is necessary to point out that ergonomics was late in paying attention to the issue of social factors and their effects on work. Carayon, (2021), urged ergonomists to take into account the influence of the social environment on work. Social environment is very important for the human being in which he practices his humanity and helps others to exercise their humanity.According to Amabile, et al. (1996) social environment includes two types of components: the positive components (autonomy/ freedom, encouragement of creativity, resources, and challenging work), and the negative components (lack of training, and management/ workers inconsistency). In this research, the researchers considered the positive components of social environment. Social ergonomics enhances the positive components of the social environment and at the same time it works to reduce the harmful effects of the negative components of the social environment. Social ergonomics achieves these goals through various methods including volunteerism. In this research, the focus will be on volunteer work. Researchers believe that volunteering strengthens social bonds, and makes individuals more connected to the community (Hsiao, et al. 2020). In addition, volunteering supports the positive elements of the social environment. “Twiza” is a form of volunteerism that is widespread in the Touat region (western area in Algeria). It means the assistance provided by members of a community, to members of another community, who are in dire need of this assistance. Objectives: This research aims to answer the following question: Can freedom /autonomy, encouragement of creativity, resources and challenging work enhance the positive components of the social environment in the Ksar?Methodology: Researchers applied the descriptive method, using a snowball technique sample which consisted of (29) volunteers from whom data were collected through a questionnaire and an Interview.Results and discussion: Individuals’ answers show that volunteer work does not affect individuals’ freedom, nor their sense of independence while working. The vast majority of respondents indicated that those who participate in voluntary work exercise their freedom naturally.Also, the volunteers show that supervisors during the volunteer work encourage them to be creative and innovative. This made them feel safe and secure.Furthermore, respondents agree that the resources required for volunteer work are available to everyone. None of the volunteers complained about the lack of resources or their unavailability. The respondents indicated that the availability of resources is a factor in the success of volunteer work.The respondents also praised the positive challenges that exist in volunteer work, especially in the maintenance of the Foggara. It is the work that made them feel they are achieving a noble patriotic duty. Conclusion: This research studied the topic of voluntary work, especially in the maintenance of Foggara in the Touat region and has found that volunteering enhances the social environment, and from the perspective of social ergonomics, that the environment is fitted to the individuals.References:Amabile, T. M., Conti, R., Coon, H., Lazenby, J., & Herron, M. (1996). Assessing the work environment for creativity. Academy of management journal, 39(5), 1154-1184.Carayon, P. (2021). Social and Organizational Foundation of Ergonomics: Multi‐Level Systems Approaches. Handbook of Human Factors and Ergonomics, 227-235.Hsiao, H. Y., Hsu, C. T., Chen, L., Wu, J., Chang, P. S., Lin, C. L., Lin M.N & Lin, T. K. (2020). Environmental volunteerism for social good: A longitudinal study of older adults’ health. Research on Social Work Practice, 30(2), 233-245.
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Zhu, Dawei, Mingyue Cui, Yandong Chen, Yongli Wang, Yunhong Ding, Chunming Xiong, Chong Liang, et al. "First Successful Application of Multi-Stage Proppant Fracturing on Horizontal Well in Carbonate Reservoirs in Iraq." In SPE International Hydraulic Fracturing Technology Conference & Exhibition. SPE, 2022. http://dx.doi.org/10.2118/205281-ms.
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Abstract The carbonate reservoir S is a giant limestone reservoir in H Oilfield, Iraq. Although the reserves account for 25%, the production contribution is only 0.4% to the total oilfield production due to poor petrophysical properties. Accordingly, the first proppant fracturing on vertical well was successfully executed in December 2016, which has already achieved a steady production period over than 3 years. In order to further improve the productivity, the first multi-stage proppant fracturing(MSPF) on horizontal well(SH01X) was successfully applied in November 2019, a technique which is rarely reported for porous limestone reservoir in the Middle East. Proppant fracturing in carbonate reservoirs is a technique difficulty worldwide, especially this is a lack of experiences in the Middle East. To ensure the success of this campaign, a holistic technical study including geology evaluation, reservoir performance analysis, drilling trajectory design, completion and fracturing technique design have been carried out based on principle of "geology-engineering integration". This paper will present a comprehensive illustration including treatment design (main completion-fracturing technique, total scale, fracturing fluid, proppant), job execution (mini-frac, main-frac) and post-frac production performance for this successful campaign. True vertical depth (TVD) of Well SH01X is 2720 m and the horizontal section length is 811 m. Based on the main technique of multi-stage proppant fracturing with open hole packers and sliding sleeves, totally 3784.3 m3 fracturing fluid and 452 m3 proppant were pumped in 8 stages. The test production was 3214 BOPD (choke size: 40/64", wellhead pressure: 970 psi). A historical breakthrough in the productivity of S reservoir has been achieved by the campaign. The post-frac evaluation shows that the treatment parameters are consistent with the design. The connectivity between artificial fractures and formation is greatly improved, and the stimulation effect is significant. Currently the "production under controlled pressure" mode has been executed and the stable production under stimulation target rate has been maintained. The systematic "geology-engineering integration" workflow is of significance to the success of the treatment as well as the stimulation effect. MSPF is planned to be a game-changing technique to develop the huge reserves of S reservoir. The experience gained from this case could provide theoretical as well as practical references for similar reservoirs in the Middle East.
Reports on the topic "S-H Bond Study"
1
Rafaeli, Ada, Wendell Roelofs, and Anat Zada Byers. Identification and gene regulation of the desaturase enzymes involved in sex-pheromone biosynthesis of pest moths infesting grain. United States Department of Agriculture, March 2008. http://dx.doi.org/10.32747/2008.7613880.bard.
Full textAbstract:
The original objectives of the approved proposal included: 1. Establishment of the biosynthetic pathways for pheromone production using labeled precursors and GC-MS. 2. The elucidation of a circadian regulation of key enzymes in the biosynthetic pathway. 3. The identification, characterization and confirmation of functional expression of the delta-desaturases. 4. The identification of gene regulatory processes involved in the expression of the key enzymes in the biosynthetic pathway. Background to the topic: Moths constitute one of the major groups of pest insects in agriculture and their reproductive behavior is dependent on chemical communication. Sex-pheromone blends are utilized by a variety of moth species to attract conspecific mates. The sex pheromones used are commonly composed of blends of aliphatic molecules that vary in chain length, geometry, degree and position of double bonds and functional groups. They are formed by various actions of specific delta-desaturases to which chain shortening, elongation, reduction, acetylation, and oxidation of a common fatty acyl precursor is coupled. In most of the moth species sex-pheromone biosynthesis is under circadian control by the neurohormone, PBAN (pheromone-biosynthesis-activating neuropeptide). The development of specific and safe insect control strategies utilizing pheromone systems depends on a clear knowledge of the molecular mechanisms involved. In this proposal we aimed at identifying and characterizing specific desaturases involved in the biosynthetic pathway of two moth pest-speciesof stored products, P. interpunctella and S. cerealella, and to elucidate the regulation of the enzymes involved in pheromone biosynthesis. Due to technical difficulties the second stored product pest was excluded from the study at an early phase of the research project. Major conclusions: Within the framework of the planned objectives we confirmed the pheromone biosynthetic pathway of P. interpunctella and H. armigera by using labeled precursor molecules. In addition, in conjunction with various inhibitors we determined the PBAN-stimulated rate-limiting step for these biosynthetic pathways. We thereby present conclusive evidence that the enzyme Acetyl Coenzyme A Carboxylase is activated as a result of PBAN stimulation. We also found that P. interpunctella produce the main pheromone component Z9, E12 Tetradecenyl acetate through the action of a D11 desaturase working on the 16:Acid precursor. This is evidenced by the high amount of incorporation of ²H-labeled 16:Acid into pheromone when compared to the incorporation of ²H-labeled 14:Acid. However, in contrast to reports on other moth species, P. interpunctella is also capable of utilizing the 14:Acid precursor, although to a much lesser extent than the 16:Acid precursor. Despite the discovery of nine different desaturase gene transcripts in this species, from the present study it is evident that although PCR detected all nine gene transcripts, specific to female pheromone glands, only two are highly expressed whereas the other 7 are expressed at levels of at least 10⁵ fold lower showing very low abundance. These two genes correspond to D11-like desaturases strengthening the hypothesis that the main biosynthetic pathway involves a D11 desaturase.