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Academic literature on the topic 'Gold Compound'

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Published: 10 March 2023

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Journal articles on the topic "Gold Compound"

1

Libben, Gary, Mira Goral, and R. Harald Baayen. "What does constituent priming mean in the investigation of compound processing?" Mental Lexicon 13, no. 2 (December 31, 2018): 269–84. http://dx.doi.org/10.1075/ml.00001.lib.

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Abstract Most dictionary definitions for the term compound word characterize it as a word that itself contains two or more words. Thus, a compound word such as goldfish is composed of the constituent words gold and fish. In this report, we present evidence that compound words such as goldfish might not contain the words gold and fish, but rather positionally bound compound constituents (e.g., gold- and -fish) that are distinct and often in competition with their whole word counterparts. This conceptualization has significant methodological consequences: it calls into question the assumption that, in a traditional visual constituent priming paradigm, the participant can be said to be presented with constituents as primes. We claim that they are not presented with constituents. Rather, they are presented with competing free-standing words. We present evidence for the processing of Hebrew compound words that supports this perspective by revealing that, counter-intuitively, prime constituent frequency has an attenuating effect on constituent priming. We relate our findings to previous findings in the study of German compound processing to show that the effect that we report is fundamentally morphological rather than positional or visual in nature. In contrast to German in which compounds are always head-final morphologically, Hebrew compounds are always head initial. In addition, whereas German compounds are written as single words, Hebrew compounds are always written with spaces between constituents. Thus, the commonality of patterning across German and Hebrew is independent of visual form and constituent ordering, revealing, as we claim, core features of the constituent priming paradigm and compound processing.
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2

Yu, Richard Ming Chuan, Gayathri Thevi Selvarajah, Geok Chin Tan, and Yoke-Kqueen Cheah. "In Vitro Growth Inhibition, Caspase-Dependent Apoptosis, and S and G2/M Phase Arrest in Breast Cancer Cells Induced by Fluorine-Incorporated Gold I Compound, Ph3PAu[SC(OMe)=NC6H4F-3]." International Journal of Breast Cancer 2022 (July 21, 2022): 1–18. http://dx.doi.org/10.1155/2022/7168210.

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Gold-based anticancer compounds have been attracting increasing research interest due to their ability to kill cancer cells resistant to platinum-based compounds. Gold I- and gold III-based complexes have shown satisfactory anticancer activities. In this study, two new fluorine-incorporated gold (I) compounds such as Ph3PAu[SC(OMe)=NC6H4F-3] and DPPFeAu2[(SC(OMe)=NC6H4F-3)]2 were evaluated for their in vitro activities against human breast cancer cell lines, primary breast cancer cells, and breast cancer stem cells (parental breast cancer stem cells, BCSC-P, and breast cancer stem cells, BCSC). Assays for growth inhibition and cytotoxicity, including real-time cell analysis, were carried out to screen effective antibreast cancer compounds. In addition, further in vitro assays such as apoptosis, caspase 3/7 activity, and cell cycle analysis were performed to observe the action and mechanism of killing breast cancer cells by the selected gold I compound, Ph3PAu[SC(OMe)=NC6H4F-3]. The gold (I) compound, Ph3PAu[SC(OMe)=NC6H4F-3], showed low toxicity to H9c2 normal cells and significant growth inhibition in MDA-MB-231 and MCF-7 cells, primary breast cancer cells, and breast cancer stem cells (BCSC-P and BCSC). The IC50 doses of the gold (I) compound Ph3PAu[SC(OMe)=NC6H4F-3] against the breast cancer cell lines MDA-MB-231 and MCF-7 were approximately 6-fold lower than that of cisplatin (cis-diamineplatinum (II) dichloride, CDDP). Moreover, the compound Ph3PAu[SC(OMe)=NC6H4F-3] induced caspase 3/7-dependent apoptosis and cell cycle arrest at S and G2/M phases. Ph3PAu[SC(OMe)=NC6H4F-3], a gold (I) compound incorporated with fluorine, is a potential candidate for the treatment of breast cancer.
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Ahrens, Birte, and Peter G. Jones. "Polysulfonylamine, CXXVIII [1]. Disulfonylamido-Gold(I)-Komplexe mit Tetrahydrothiophen als Ligand / Polysulfonylamines, CXXVIII. Disulfonylamido-gold(I) Complexes with Tetrahydrothiophene as Ligand." Zeitschrift für Naturforschung B 55, no. 9 (September 1, 2000): 803–13. http://dx.doi.org/10.1515/znb-2000-0904.

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The molecular gold(I) complexes di(methanesulfonyl)amido-/V-(tetrahydrothiophene)gold(I) (1), di(p-chlorobenzenesulfonyl)amido-/V-(tetrahydrothiophene)gold(I) (2), and di(p-iodobenzenesulfonyl) amido-/V-(tetrahydrothiophene)gold(I) (3), were synthesised from (tetrahydrothiophene) chlorogold(I) and the appropriate silver salt. Crystal structure analyses were performed for all three compounds (3 both solvent-free and as a dichloromethane solvate 3a) and revealed a variety of intermolecular contacts. Compound 1 crystallizes with four independent molecules, two of which are connected by a gold-gold interaction of 3.2869(8) Å; several short nonclassical hydrogen bonds of the form C-H · O (the shortest with H · O 2.31 A) are observed. In compound 2, cyclodimers are formed via Au · Au contacts of 3.3302(8) Å; additionally Cl · Cl contacts of 3.457(3) Å are observed. Both forms of compound 3 are characterized by Au · I contacts, somewhat longer in 3 (3.6 - 4.3 Å) than in 3a (3.4 - 3.5 Å). The di(arenesulfonyl)amide ligands in 2, 3 and 3a display approximate C2 symmetry
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Cui, Qingbin, Wenwen Ding, Panpan Liu, Bingling Luo, Jing Yang, Wenhua Lu, Yumin Hu, Peng Huang, and Shijun Wen. "Developing Bi-Gold Compound BGC2a to Target Mitochondria for the Elimination of Cancer Cells." International Journal of Molecular Sciences 23, no. 20 (October 12, 2022): 12169. http://dx.doi.org/10.3390/ijms232012169.

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Reactive oxygen species (ROS) homeostasis and mitochondrial metabolism are critical for the survival of cancer cells, including cancer stem cells (CSCs), which often cause drug resistance and cancer relapse. Auranofin is a mono-gold anti-rheumatic drug, and it has been repurposed as an anticancer agent working by the induction of both ROS increase and mitochondrial dysfunction. Hypothetically, increasing auranofin’s positive charges via incorporating more gold atoms to enhance its mitochondria-targeting capacity could enhance its anti-cancer efficacy. Hence, in this work, both mono-gold and bi-gold compounds were designed and evaluated to test our hypothesis. The results showed that bi-gold compounds generally suppressed cancer cells proliferation better than their mono-gold counterparts. The most potent compound, BGC2a, substantially inhibited the antioxidant enzyme TrxR and increased the cellular ROS. BGC2a induced cell apoptosis, which could not be reversed by the antioxidant agent vitamin C, implying that the ROS induced by TrxR inhibition might not be the decisive cause of cell death. As expected, a significant proportion of BGC2a accumulated within mitochondria, likely contributing to mitochondrial dysfunction, which was further confirmed by measuring oxygen consumption rate, mitochondrial membrane potential, and ATP production. Moreover, BGC2a inhibited colony formation and reduced stem-like side population (SP) cells of A549. Finally, the compound effectively suppressed the tumor growth of both A549 and PANC-1 xenografts. Our study showed that mitochondrial disturbance may be gold-based compounds’ major lethal factor in eradicating cancer cells, providing a new approach to developing potent gold-based anti-cancer drugs by increasing mitochondria-targeting capacity.
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Sun, Yin-Wei, Xiang-Ying Tang, and Min Shi. "A gold-catalyzed 1,2-acyloxy migration/intramolecular cyclopropanation/ring enlargement cascade: syntheses of medium-sized heterocycles." Chemical Communications 51, no. 73 (2015): 13937–40. http://dx.doi.org/10.1039/c5cc05808b.

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A gold catalyzed 1,2-acyloxy migration/intramolecular cyclopropanation/ring enlargement cascade of furan substrates provides a new highly efficient procedure for the formation of ten and eleven-membered ring compounds. A new transformation type of intermolecular furan compound catalyzed by a gold catalyst was reported.
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Galassi, Rossana, Lorenzo Luciani, Junbiao Wang, Silvia Vincenzetti, Lishan Cui, Augusto Amici, Stefania Pucciarelli, and Cristina Marchini. "Breast Cancer Treatment: The Case of Gold(I)-Based Compounds as a Promising Class of Bioactive Molecules." Biomolecules 12, no. 1 (January 5, 2022): 80. http://dx.doi.org/10.3390/biom12010080.

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Breast cancers (BCs) may present dramatic diagnoses, both for ineffective therapies and for the limited outcomes in terms of lifespan. For these types of tumors, the search for new drugs is a primary necessity. It is widely recognized that gold compounds are highly active and extremely potent as anticancer agents against many cancer cell lines. The presence of the metal plays an essential role in the activation of the cytotoxicity of these coordination compounds, whose activity, if restricted to the ligands alone, would be non-existent. On the other hand, gold exhibits a complex biochemistry, substantially variable depending on the chemical environments around the central metal. In this review, the scientific findings of the last 6–7 years on two classes of gold(I) compounds, containing phosphane or carbene ligands, are reviewed. In addition to this class of Au(I) compounds, the recent developments in the application of Auranofin in regards to BCs are reported. Auranofin is a triethylphosphine-thiosugar compound that, being a drug approved by the FDA—therefore extensively studied—is an interesting lead gold compound and a good comparison to understand the activities of structurally related Au(I) compounds.
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Fonseca, Custódia, Gil Fraqueza, Sónia A. C. Carabineiro, and Manuel Aureliano. "The Ca2+-ATPase Inhibition Potential of Gold(I, III) Compounds." Inorganics 8, no. 9 (August 30, 2020): 49. http://dx.doi.org/10.3390/inorganics8090049.

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The therapeutic applications of gold are well-known for many centuries. The most used gold compounds contain Au(I). Herein, we report, for the first time, the ability of four Au(I) and Au(III) complexes, namely dichloro (2-pyridinecarboxylate) Au(III) (abbreviated as 1), chlorotrimethylphosphine Au(I) (2), 1,3-bis(2,6-diisopropylphenyl) imidazole-2-ylidene Au(I) chloride (3), and chlorotriphenylphosphine Au(I) (4), to affect the sarcoplasmic reticulum (SR) Ca2+-ATPase activity. The tested gold compounds strongly inhibit the Ca2+-ATPase activity with different effects, being Au(I) compounds 2 and 4 the strongest, with half maximal inhibitory concentration (IC50) values of 0.8 and 0.9 µM, respectively. For Au(III) compound 1 and Au(I) compound 3, higher IC50 values are found (4.5 µM and 16.3 µM, respectively). The type of enzymatic inhibition is also different, with gold compounds 1 and 2 showing a non-competitive inhibition regarding the native substrate MgATP, whereas for Au compounds 3 and 4, a mixed type of inhibition is observed. Our data reveal, for the first time, Au(I) compounds with powerful inhibitory capacity towards SR Ca2+ATPase function. These results also show, unprecedently, that Au (III) and Au(I) compounds can act as P-type ATPase inhibitors, unveiling a potential application of these complexes.
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Schmidbaur, Hubert, Gabriele Weidenhiller, Aref A. M. Aly, Oliver Steigelmann, and Gerhard Müller. "Gold(I)-Komplexe sekundärer Phosphine / Gold(I) Complexes of Secondary Phosphines." Zeitschrift für Naturforschung B 44, no. 12 (December 1, 1989): 1503–8. http://dx.doi.org/10.1515/znb-1989-1206.

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Gold(I) complexes with secondary phosphines R2PH (la—d) of the type R2PH · AuCl (2a—d) have been obtained in good yield from reactions of (carbonyl)chlorogold(I) and the corresponding ligand in diethylether. Both compounds 2a, b bearing aromatic substituents with R = 2,4,6-trimethylphenyl (mesityl) and 2-methylphenyl (o-tolyl), and compounds 2c, d with the bulky alkyl substituents R = t-butyl and R = cyclohexyl, resp., are air-stable crystalline solids. — The coordination compounds have been characterized by NMR and IR data, and — in the cases of 2b and 2c — by single crystal X-ray diffraction studies. Crystals of these two compounds are both monoclinic, space group P21/c with four formula units (Z = 4). The analysis shows independent monomers for compound 2c with no intermolecular Au···Au contacts. Molecules of 2b are arranged in centrosymmetrical dimers (head to tail) with an Au···Au distance of 3.56 Å and a dihedral angle P—Au—Au′—P′ of 180°. (This structural study is as yet incomplete and suffers from an unsatisfactory data set for 2b.) It appears that intermolecular contacts are largely controlled by steric effects.
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9

Fonseca, Custódia, and Manuel Aureliano. "Biological Activity of Gold Compounds against Viruses and Parasitosis: A Systematic Review." BioChem 2, no. 2 (May 14, 2022): 145–59. http://dx.doi.org/10.3390/biochem2020010.

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In this contribution, we provide an overview of gold compound applications against viruses or parasites during recent years. The special properties of gold have been the subject of intense investigation in recent years, which has led to the development of its chemistry with the synthesis of new compounds and the study of its applicability in various areas such as catalysis, materials, nanotechnology and medicine. Herein, thirteen gold articles with applications in several viruses, such as hepatitis C virus (HCV), influenza A virus (H1N1), vesicular stomatitis virus (VSV), coronavirus (SARS-CoV and SARS-CoV-2), Dengue virus, and several parasites such as Plasmodium sp., Leishmania sp., Tripanossoma sp., Brugia sp., Schistosoma sp., Onchocerca sp., Acanthamoeba sp., and Trichomonas sp. are described. Gold compounds with anti-viral activity include gold nanoparticles with the ligands mercaptoundecanosulfonate, 1-octanethiol and aldoses and gold complexes with phosphine and carbene ligands. All of the gold compounds with anti-parasitic activity reported are gold complexes of the carbene type. Auranofin is a gold drug already used against rheumatoid arthritis, and it has also been tested against virus and parasites.
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Pawlędzio, Sylwia, Maura Malinska, Magdalena Woińska, Jakub Wojciechowski, Lorraine Andrade Malaspina, Florian Kleemiss, Simon Grabowsky, and Krzysztof Woźniak. "Relativistic Hirshfeld atom refinement of an organo-gold(I) compound." IUCrJ 8, no. 4 (May 26, 2021): 608–20. http://dx.doi.org/10.1107/s2052252521004541.

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The main goal of this study is the validation of relativistic Hirshfeld atom refinement (HAR) as implemented in Tonto for high-resolution X-ray diffraction datasets of an organo-gold(I) compound. The influence of the relativistic effects on statistical parameters, geometries and electron density properties was analyzed and compared with the influence of electron correlation and anharmonic atomic motions. Recent work in this field has indicated the importance of relativistic effects in the static electron density distribution of organo-mercury compounds. This study confirms that differences in electron density due to relativistic effects are also of significant magnitude for organo-gold compounds. Relativistic effects dominate not only the core region of the gold atom, but also influence the electron density in the valence and bonding region, which has measurable consequences for the HAR refinement model parameters. To study the effects of anharmonic motion on the electron density distribution, dynamic electron density difference maps were constructed. Unlike relativistic and electron correlation effects, the effects of anharmonic nuclear motion are mostly observed in the core area of the gold atom.
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Dissertations / Theses on the topic "Gold Compound"

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Lum, Ching-tung. "Treatment of hepatocellular carcinoma with a novel gold compound." Click to view the E-thesis via HKUTO, 2005. http://sunzi.lib.hku.hk/hkuto/record/B30699927.

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Lum, Ching-tung, and 林菁潼. "Treatment of hepatocellular carcinoma with a novel gold compound." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2005. http://hub.hku.hk/bib/B30699927.

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Naoe, Saori. "Synthesis of Fused-Ring Compounds through Gold-Catalyzed Cascade Reactions." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215495.

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Schiller, Tara Louise. "Synthesis and characterisation of hybrid gold/polymer nanoparticles for bioassay application." Thesis, Queensland University of Technology, 2010. https://eprints.qut.edu.au/43445/1/Tara_Schiller_Thesis.pdf.

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A bioassay technique, based on surface-enhanced Raman scattering (SERS) tagged gold nanoparticles encapsulated with a biotin functionalised polymer, has been demonstrated through the spectroscopic detection of a streptavidin binding event. A methodical series of steps preceded these results: synthesis of nanoparticles which were found to give a reproducible SERS signal; design and synthesis of polymers with RAFT-functional end groups able to encapsulate the gold nanoparticle. The polymer also enabled the attachment of a biotin molecule functionalised so that it could be attached to the hybrid nanoparticle through a modular process. Finally, the demonstrations of a positive bioassay for this model construct using streptavidin/biotin binding. The synthesis of silver and gold nanoparticles was performed by using tri-sodium citrate as the reducing agent. The shape of the silver nanoparticles was quite difficult to control. Gold nanoparticles were able to be prepared in more regular shapes (spherical) and therefore gave a more consistent and reproducible SERS signal. The synthesis of gold nanoparticles with a diameter of 30 nm was the most reproducible and these were also stable over the longest periods of time. From the SERS results the optimal size of gold nanoparticles was found to be approximately 30 nm. Obtaining a consistent SERS signal with nanoparticles smaller than this was particularly difficult. Nanoparticles more than 50 nm in diameter were too large to remain suspended for longer than a day or two and formed a precipitate, rendering the solutions useless for our desired application. Gold nanoparticles dispersed in water were able to be stabilised by the addition of as-synthesised polymers dissolved in a water miscible solvent. Polymer stabilised AuNPs could not be formed from polymers synthesised by conventional free radical polymerization, i.e. polymers that did not possess a sulphur containing end-group. This indicated that the sulphur-containing functionality present within the polymers was essential for the self assembly process to occur. Polymer stabilization of the gold colloid was evidenced by a range of techniques including, visible spectroscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis and Raman spectroscopy. After treatment of the hybrid nanoparticles with a series of SERS tags, focussing on 2-quinolinethiol the SERS signals were found to have comparable signal intensity to the citrate stabilised gold nanoparticles. This finding illustrates that the stabilization process does not interfere with the ability of gold nanoparticles to act as substrates for the SERS effect. Incorporation of a biotin moiety into the hybrid nanoparticles was achieved through a =click‘ reaction between an alkyne-functionalised polymer and an azido-functionalised biotin analogue. This functionalized biotin was prepared through a 4-step synthesis from biotin. Upon exposure of the surface-bound streptavidin to biotin-functionalised polymer hybrid gold nanoparticles, then washing, a SERS signal was obtained from the 2-quinolinethiol which was attached to the gold nanoparticles (positive assay). After exposure to functionalised polymer hybrid gold nanoparticles without biotin present then washing a SERS signal was not obtained as the nanoparticles did not bind to the streptavidin (negative assay). These results illustrate the applicability of the use of SERS active functional-polymer encapsulated gold nanoparticles for bioassay application.
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Pouliwe, Antibe. "Electrochemical Studies of The Interaction Between DNA and a Compound Having Anticancer Properties." Digital Commons @ East Tennessee State University, 2011. https://dc.etsu.edu/etd/1352.

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Electrochemical method has been used to study the interaction between DNA and the compound N-(3',6'-dihydroxy-3-oxospiro[isobenzofuran-1(3H),9'-[9H]xanthen]-5-yl)-N'-(2-imidazoyl)urea having anticancer properties. A DNA modified nanometer-sized gold electrode was prepared by surface modification of a bare gold electrode using cysteamine. These electrodes have been characterized using electrochemical techniques and were used to study the interaction between DNA and the compound. Our results showed an increase in the adsorption peak current and a negative shift of E1/2 in the oxidation of ferrocyanide on cysteamine and DNA modified electrodes. For the interaction between the DNA and the compound having anticancer properties, a decrease in peak current of the oxidation of ferrocyanide was observed. The decrease in peak current is attributed to the shielding of the electroactive species by the compound intercalated to the DNA from reaching the electrode surface. Therefore, only few of the electroactive species are able to reach the electrode surface.
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Arslan, Yasin. "Development Of Novel Analytical Methods For Selenium, Gold, Silver And Indium Determination Using Volatile Compound Generation, Atom Trapping And Atomic Absorption Spectrometry." Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613233/index.pdf.

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A novel analytical technique was developed where gaseous hydrogen selenide formed by sodium tetrahydroborate reduction is transported to and trapped on a resistively heated gold-coated W-coil atom trap for in situ preconcentration. The atom trap is held at 165 º
C during the collection stage and is heated up to 675 º
C for revolatilization
analyte species formed are transported to an externally heated quartz T-tube where the atomization takes place and the transient signal is obtained. For gold, a high volume gas liquid separator (HVGLS) was designed to improve the detection limit of Au down to the ng mL-1 levels. In this apparatus, analyte and reductant solutions are collected in a limited volume and volatile analyte species are formed. After separation of the volatile analyte species from liquid phase, the entire analyte vapor is sent to an atomizer. A W-coil trap was used to further decrease the detection limit. The enhancement factor for the characteristic concentration was found to be 10.7 when compared to HG-AAS performance without W-coil trap by using peak height values. Furthermore, the generation of analytically useful volatile form of Au has been studied. The flow injection generation was performed in a dedicated generator consisting of a special mixing apparatus and gas-liquid separator design. The on-line atomization in the quartz tube multiatomizer for atomic absorption (AAS) detection has been employed as the convenient atomization/detection mean. 198Au, 199Au radioactive indicator of high specific activity together with AAS measurements was used to track quantitatively the transfer of analyte in the course of generation and transport to the atomizer. In-situ trapping in GF for AAS was explored as an alternative to the on-line atomization. Transmission electron microscopy measurements proved the presence of Au nanoparticles of diameter of approximately 10 nm and smaller transported from the generator by the flow of carrier Ar. For silver, three types of GLS which are U-shaped, cylindrical and high volume gas liquid separators (HVGLS) were used to compare the sensitivities of these GLSs during Ag determination. The DL (3s) values were found as 29 ng mL-1, 0.4 ng mL-1 and 0.05 ng mL-1 for U-shaped GLS, cylindrical GLS with W-coil trap and HVGLS with W-coil trap, respectively. For indium, two types of GLS which are cylindrical and HVGLS with W-coil trap were used. The LOD and characteristic concentration were found as 148 and 317 ng mL-1 with cylindrical shape GLS. HVGLS with W-coil trap was used to improve sensitivity. In this case, LOD and characteristic concentration were found to be 0.46 and 0.98 ng mL-1, respectively. Moreover, to increase the reactivity between indium and reductant solutions, Ru(acac)3 catalyst was used. In this case, LOD and characteristic concentration were found to be 0.13 and 0.23 ng mL-1, respectively. In the case of using this catalyst, sensitivity was enhanced around 1378 fold with respect to cylindrical GLS.
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7

Coetzee, Karolien. "Gold complexes obtained from gold ylide preparations." Thesis, Stellenbosch : Stellenbosch University, 2005. http://hdl.handle.net/10019.1/21206.

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Thesis (MSc)--University of Stellenbosch, 2005.
ENGLISH ABSTRACT: This investigation comprised the synthesis and characterisation of new Au(I) phosphonium ylide complexes and other compounds formed during coordination reactions. These complexes could exploit the synergism between two pharmacologically active substances (gold complex unit and phosphorus ylide) to furnish an even more active substance. Four phosphonium salts were prepared, [C6H5CH2PPh3]Br (1), [Ph3P(CH2)3PPh3]Br2 (2a), p-[{Ph3PCH2}2C6H4]Br2 (3a) and m- [{Ph3PCH2}2C6H4]Br2 (4a), by reacting PPh3 with the corresponding alkylbromides. The 13C and 1H NMR spectra of the compounds 1 – 4a indicated that many of the nuclei are magnetically inequivalent. The aromatic units in PPh3 are normally identical, but multiple, overlapping signals proved that the corresponding ortho, meta and para carbon and proton nuclei are in magnetically different environments from each other. Single crystal structures of salts 3a and 4a were determined. Different methods were followed to deprotonate the phosphonium salts to afford the corresponding ylides and to coordinate the ylides to gold precursor compounds. Most of the reactions yielded inseparable mixtures of products and pure compounds could not be isolated in large enough quantities for characterisation by all physical methods. Sufficient crystals for structure determination by X-ray diffraction were obtained. The product mixtures were characterised by 1H, 13C and 31P NMR spectroscopy and mass spectrometry. Characteristic downfield chemical shift changes after coordination of the ylides to Au(I) were observed for the carbon and phosphorus nuclei, while the protons displayed upfield shifts. Reaction of (C6F5)Au(tht) with the salts 1 – 4a, and subsequent deprotonation yielded the gold(I) ylide complexes [C6H5CH(AuC6F5)PPh3] (5), [{Ph3PCH(AuC6F5)}2CH2] (6), p-[{Ph3PCH(AuC6F5)}2C6H4] (8), and m- [{Ph3PCH(AuC6F5)}2C6H4] (9). The crystal and molecular structures of compounds 5 and 9 were determined. Deprotonation of 4a with n-BuLi, followed by reaction with (C6F5)Au(tht) yielded complexes 9 and [{Ph3PCH2}2C6H4][BrAuC6F5]2 (10). The crystal structure of compound 10 was determined. Two aurocyclic compounds, [μ- {(Ph3PCH)2CH2}2Au2][BF4]2 (12) and [μ–{(Ph3PCH)2C6H4}2Au2][BF4]2 (13) were synthesised by deprotonating salts 2b and 3b with n-BuLi and subsequently reacting the corresponding bisylides with ClAu(tht). Reaction procedures in which Ag2O was used as deprotonating agent for the phosphonium salts 2a, 3a and 4a, yielded mixtures of products. Single crystals of complexes m-[Ph3PCH(AuC6F5)C6H4CH3] (14), [C6F5Au(tht)] (15) and [(C6F5)2Au][(Ph3PCH2)2C6H4] (16) were isolated from the reaction mixtures and subjected to X-ray crystal structure determination. The molecular structure of 15 exhibited unusual aurophilic interactions and represents the first example of a linear gold chain in which the gold···gold distances systematically alternate between 3.13Å, 3.31Å and 3.20Å. Salt 2b was reacted with Ph3PAu(acac) to afford the desired compound, [{Ph3PCH(AuPPh3)}2CH2](BF4)2 (19), along with [CH3C(O)C(AuPPh3)2C(O)CH3] (17) and some byproducts. Compound 17 was characterised by single crystal Xray diffraction. The fluorobiphenylgold(I) complexes, 4,4’-[(AuPPh3)2C12F8] (21) and 2,2’- [(AuPPh3)2C12F8] (22) were synthesised by reaction of ClAuPPh3 with the lithiated 2,2’-dibromooctafluorobiphenyl and 4,4’-dibromooctafluorobiphenyl respectively. The molecular structure of 21 revealed that one of the C–Au–P bond angles deviates from linearity by 12.5°, probably as a result of π-stacking of the tetrafluorophenyl rings and steric requirements of the bulky PPh3 units. The other C–Au–P bond angle is linear [177.9(3)°].
AFRIKAANSE OPSOMMING: Hierdie studie behels die sintese en karakterisering van nuwe fosfoniumylied goud(I)-komplekse en ander verbindings wat gedurende koördinasiereaksies vorm. Sulke komplekse kan sinergisme tussen twee farmakologies-aktiewe entiteite (goud(I) en fosfoniumylied) om ʼn meer aktiewe verbinding te vorm meebring. Vier fosfoniumsoute is berei, [C6H5CH2PPh3]Br (1), [Ph3P(CH2)3PPh3]Br2 (2a), p- [{Ph3PCH2}2C6H4]Br2 (3a) en m-[{Ph3PCH2}2C6H4]Br2 (4a), deur PPh3 met die ooreenstemmende alkielbromiedes te reageer. Die 13C- en 1H- KMR-spektra van dié verbindings toon dat ʼn aantal kerne in aromatiese ringe magneties onekwivalent is. Normaalweg is die koolstowwe in PPh3-eenhede ekwivalent, maar meervoudige, oorvleuelende pieke het nou getoon dat die ooreenstemmende orto-, meta- en para-koolstof sowel as die ooreenstemmende protonkerne in verskillende magnetiese omgewings voorkom. Die kristalstrukture van die soute 3a en 4a hierbo is met behulp van X-straal tegnieke bepaal. Verskillende metodes is gevolg om die fosfoniumsoute te deprotoneer na die ooreenstemmende yliede en om die yliede dan aan goud-bevattende uitgangstowwe te probeer koördineer. Die meeste reaksies het nie-skeibare mengsels gevorm en enkelprodukte kon nie in groot genoeg konsentrasies geïsoleer word om hulle afsonderlik te karakteriseer nie. Kristalle vir X-straal kristalstruktuur bepalings is verkry. Die produkmengsels is gekarakteriseer met behulp van 1H-, 13C- en 31P- KMR-spektroskopie en massaspektrometrie. Karakteristieke veranderinge in chemiese verskuiwings na laer veldsterktes vir die koolstof en fosfor kerne is waargeneem na koördinasie van die yliede aan Au(I), terwyl die protone na höer veldsterktes verskuif het. Die reaksie tussen (C6F5)Au(tht) (tetrahidrotiofeen) en soute 1 – 4a gevolg deur deprotonering, vorm die goud-yliedkomplekse [C6H5CH(AuC6F5)PPh3] (5), [{Ph3PCH(AuC6F5)}2CH2] (6), p-[{Ph3PCH(AuC6F5)}2C6H4] (8), en m- [{Ph3PCH(AuC6F5)}2C6H4] (9). Die kristalstrukture van komplekse 5 en 9 het al die molekulêre interaksies daarin blootgelê. Deprotonering van 4a met n-BuLi, gevolg deur reaksie met (C6F5)Au(tht) lewer komplekse 9 en [{Ph3PCH2}2C6H4][BrAuC6F5]2 (10). Die kristal- en molekulêre struktuuur van kompleks 10 is bepaal. Twee aurosikliese verbindings, [μ- {(Ph3PCH)2CH2}2Au2][BF4]2 (12) en [μ–{(Ph3PCH)2C6H4}2Au2][BF4]2 (13) is gesintetiseer deur gedeprotoneerde bisyliede verkry van 2b en 3b met substitusie van tht aan die ClAu-eenheid te koördineer. Reaksieprosedures waarin Ag2O vir deprotonering van die fosfoniumsoute 2a, 3a en 4a gebruik is, het tot mengsels van produkte aanleiding gegee. Enkelkristalle van komplekse [Ph3PCH(AuC6F5)C6H4CH3] (14), [C6F5Au(tht)] (15) en [(C6F5)2Au][(Ph3PCH2)2C6H4] (16) is geïsoleer uit die reaksies en kristalstruktuurbepalings is uitgevoer. Die molekulere struktuur van 15 toon ongewone aurofiliese interaksies en verteenwoordig die eerste voorbeeld van ʼn linieêre goudketting; met goud···goud afstande wat sistematies varieër tussen 3.13Å, 3.31Å en 3.20Å. Sout 2b is met Ph3PAu(acac) gereageer om die gewenste produk, [{Ph3PCH(AuPPh3)}2CH2](BF4)2 (19), saam met [CH3C(O)C(AuPPh3)2C(O)CH3] (17) en ander byprodukte te vorm. Verbinding 17 is as enkelkristalle Xstraalkristallografies gekarakteriseer. Die fluorobifeniel goud(I)-komplekse, 4,4’-[(AuPPh3)2C12F8] (21) en 2,2’- [(AuPPh3)2C12F8] (22), is gesintetiseer deur koördinasie van AuPPh3 aan die gelitieërde 2,2’-dibromooktafluorobifeniel en 4,4’-dibromooktafluorobifeniel respektiewelik. Die molekulere struktuur van 21 het getoon dat een van die C-Au- P bindingshoeke met 12.5º afwyk van 180º, waarskynlik as gevolg van π- interaksie van die tetrafluorofenielringe en die steriese vereistes van die groot PPh3-eenhede. Die ander C-Au-P bindingshoek is linieêr [177.9(3)°].
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Yang, Yi. "Gold(I) oxo, imido, hydrazido complexes and gold clusters /." free to MU campus, to others for purchase, 1996. http://wwwlib.umi.com/cr/mo/fullcit?p9841362.

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Coetzee, Jacorien. "New developments in the coordination chemistry of gold(1), gold(II) and gold(III) with C-, N-, P-and S-Donor ligands /." Link to the online version, 2007. http://hdl.handle.net/10019/412.

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LeBlanc, Daren James. "Thiol complexes of gold(I) : structure and chemistry of the gold based anti-arthritis drugs /." *McMaster only, 1996.

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Books on the topic "Gold Compound"

1

Walsh, Daniel E. Study of a static screen, jig, spiral, and a compound water cyclone in a placer gold recovery plant. Fairbanks, Alaska: Mineral Industry Research Laboratory, School of Mineral Engineering, University of Alaska Fairbanks, 1987.

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Saul, Patai, and Rappoport Zvi, eds. The chemistry of organic derivatives of gold and silver. New York: Wiley, 1999.

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Antonio, Laguna, ed. Modern supramolecular gold chemistry: Gold-metal interactions and applications. Weinheim: Wiley-VCH, 2008.

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Simpozium "Nanogeokhimii︠a︡ zolota" (2008 Vladivostok, Russia). Nanogeokhimii︠a︡ zolota: Trudy simpoziuma, Vladivostok, 17-18 apreli︠a︡ 2008 g.. Vladivostok: Dalʹnauka, 2008.

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Simpozium "Nanogeokhimii︠a︡ zolota" (2008 Vladivostok, Russia). Nanogeokhimii︠a︡ zolota: Trudy simpoziuma, Vladivostok, 17-18 apreli︠a︡ 2008 g.. Vladivostok: Dalʹnauka, 2008.

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J, Welch Alan, Chapman Stephen K, and Royal Society of Chemistry (Great Britain), eds. The chemistry of the copper and zinc triads. Cambridge: Royal Society of Chemistry, 1993.

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1915-, Dirkse T. P., Michalowski T, Akaiwa H, and Izumi F, eds. Copper, silver, gold and zinc, cadmium, mercury, oxides and hydroxides. Oxford: Pergamon, 1986.

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Watterson, John R. A pyrolysis-gas chromatographic study of organic matter from Snake River flake-type placer gold particles. [Denver, CO]: U.S. Geological Survey, 1995.

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S, Leventhal Joel, and Geological Survey (U.S.), eds. A pyrolysis-gas chromatographic study of organic matter from Snake River flake-type placer gold particles. [Reston, Va.]: U.S. Dept. of the Interior, U.S. Geological Survey, 1995.

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S, Leventhal Joel, and Geological Survey (U.S.), eds. A pyrolysis-gas chromatographic study of organic matter from Snake River flake-type placer gold particles. [Reston, Va.]: U.S. Dept. of the Interior, U.S. Geological Survey, 1995.

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Book chapters on the topic "Gold Compound"

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Castelli, Silvia, Oscar Vassallo, Prafulla Katkar, Chi-Ming Che, Raymond Wai-Yin Sun, and Alessandro Desideri. "Gold(III), Cyclometalated Compound, Inhibition of Human DNA Topoisomerase IB." In Encyclopedia of Metalloproteins, 927–32. New York, NY: Springer New York, 2013. http://dx.doi.org/10.1007/978-1-4614-1533-6_558.

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Katoch, Mitaali. "From Grain to Gold: The Regeneration of New Delhi’s Dhan Mill Compound." In Design of the Unfinished, 135–45. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-73457-2_8.

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Chipperfield, J. R. "Compounds of Gold." In Inorganic Reactions and Methods, 360. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2007. http://dx.doi.org/10.1002/9780470145289.ch144.

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Berners-Price, Susan J., and Peter J. Barnard. "Therapeutic Gold Compounds." In Ligand Design in Medicinal Inorganic Chemistry, 227–56. Chichester, UK: John Wiley & Sons, Ltd, 2014. http://dx.doi.org/10.1002/9781118697191.ch9.

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Dai, Wensheng, Chi-Jie Lu, and Tingjen Chang. "Empirical Research of Price Discovery for Gold Futures Based on Compound Model Combing Wavelet Frame with Support Vector Regression." In Artificial Intelligence and Computational Intelligence, 374–81. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-16527-6_47.

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Shaw, C. Frank. "Gold." In Metal Compounds in Cancer Therapy, 46–64. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-1252-9_3.

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Macintyre, J. E. "Au Gold." In Dictionary of Organometallic Compounds, 42–45. Boston, MA: Springer US, 1986. http://dx.doi.org/10.1007/978-1-4615-6847-6_4.

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MacIntyre, Jane E. "Au Gold." In Dictionary of Organometallic Compounds, 20–26. Boston, MA: Springer US, 1996. http://dx.doi.org/10.1007/978-1-4899-6848-7_4.

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Macintyre, J. E., F. M. Daniel, D. J. Cardin, S. A. Cotton, R. J. Cross, A. G. Davies, R. S. Edmundson, et al. "Au Gold." In Dictionary of Organometallic Compounds, 15–17. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4757-4966-3_4.

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Nagy, Zoltán. "Au—Gold." In Electrochemical Synthesis of Inorganic Compounds, 17–18. Boston, MA: Springer US, 1985. http://dx.doi.org/10.1007/978-1-4899-0545-1_5.

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Conference papers on the topic "Gold Compound"

1

Wai, Leong Ching, and David Ho. "Assessing of Wire Bonding on Gold Plated Pads on Epoxy Mold Compound Wafer." In 2019 IEEE 21st Electronics Packaging Technology Conference (EPTC). IEEE, 2019. http://dx.doi.org/10.1109/eptc47984.2019.9026571.

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Wong, Jason, Alvin Seah, and Spencer Chew. "Application of Time Domain Reflectometry in Evaluating Irregular Inter-metallic Compound Growth in Gold Wire Bonds Encapsulated with Green Epoxy Mold Compound." In 2007 14th International Symposium on the Physical and Failure Analysis of Integrated Circuits. IEEE, 2007. http://dx.doi.org/10.1109/ipfa.2007.4378085.

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Qin, Wentao. "Corrosion Mechanisms of Copper and Gold Ball Bonds." In ISTFA 2022. ASM International, 2022. http://dx.doi.org/10.31399/asm.cp.istfa2022p0310.

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Abstract Copper ball bonding is the most widely used interconnection method in microelectronic packages. It has enabled many modern technologies, but the bond can fail due to corrosion. This paper concerns quantitative analyses of corrosion products of passing and failing copper ball bonds, and correlation with the corrosion thermodynamics. The role each element in the aluminum-copper intermetallic compound plays during crevice corrosion is described, and relative abundances of the oxidized elements are estimated. New insights regarding mechanisms of the highest vulnerability to corrosion attack in the thin film-stack across the bond are presented. Limited data indicate the same corrosion mechanisms for Au ball bonds.
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Abdalbari, Farah H., Alicia A. Goyeneche, Elvis Martinez-Jaramillo, Siham Sabri, and Carlos M. Telleria. "Abstract 1014: Repurposing the anti-rheumatic gold compound auranofin for high-grade serous ovarian cancer therapy." In Proceedings: AACR Annual Meeting 2021; April 10-15, 2021 and May 17-21, 2021; Philadelphia, PA. American Association for Cancer Research, 2021. http://dx.doi.org/10.1158/1538-7445.am2021-1014.

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Aiyer, Chandrasekhar R., Satoshi Itoh, Hitomi Yamada, Shinzo Morita, and Shuzo Hattori. "X Ray Mask Of Gold-Carbon Mixture Absorber On BCN Compound Substrate Fabricated By Plasma Processes." In Medical Imaging II, edited by Arnold W. Yanof. SPIE, 1988. http://dx.doi.org/10.1117/12.945628.

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Tsai, Tsung-Lin, Kao-Shu Chuang, Jih-Ru Hwu, Chen-Sheng Yeh, Wu-Chou Su, and Dar-Bin Shieh. "Photoactive Compound-Triplex-Forming Oligonucleotide Linked Gold Nanoparticle as an Artificial Gene Specific DNA Cleaver Assembly." In 2008 8th IEEE Conference on Nanotechnology (NANO). IEEE, 2008. http://dx.doi.org/10.1109/nano.2008.263.

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Amin, Al, Shamik Datta, Megan Keniry, Ahmed Touhami, and Hasina Huq. "Preparation and Characterization of DC Magnetron Sputtered Thin Films of Titanium, Silver, Gold and Their Compound." In 2022 IEEE Green Technologies Conference (GreenTech). IEEE, 2022. http://dx.doi.org/10.1109/greentech52845.2022.9772018.

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Gallo, Anthony A. "Effect of Mold Compound Components on Moisture-Induced Degradation of Gold-Aluminum Bonds in Epoxy Encapsulated Devices." In 28th International Reliability Physics Symposium. IEEE, 1990. http://dx.doi.org/10.1109/irps.1990.363528.

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Liao, Lois, Xi Zhang, Younan Hua, and Li Xiaomin. "Chlorine and Sulfur Effects on Gold-Aluminum Wire Bond Reliability." In ISTFA 2022. ASM International, 2022. http://dx.doi.org/10.31399/asm.cp.istfa2022p0374.

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Abstract Currently, wire bonding is still the dominant interconnection mode in microelectronic packaging, and epoxy molding compound (EMC) is the major encapsulant material. Normally EMC contains chlorine (Cl) and sulfur (S) ions. It is important to understand the control limit of Cl and S in the EMC to ensure good Au wire bond reliability. This paper discussed the influences of Cl and S on the Au wire bond. Different contents of Cl and S were purposely added into the EMC. Accelerated reliability tests were performed to understand the effects of Cl, S and their contents on the Au wire bond reliability. Failure analysis has been conducted to study the failure mechanism. It is found that Cl reacted with IMCs under humid environment. Cl also caused wire bond failure in HTS test without moisture. On the other hand, the results showed that S was not a corrosive ion. It was also not a catalyst to the Au bond corrosion. Whilst, high content of S remain on the bond pad hindered the IMCs formation and caused earlier failure of the wire bond.
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Hsieh, Chin Chun, Ming Chang Shih, and W. H. Lan. "The improvement of delaminating at interface between molding compound and Gold substrate bond pad in BGA(ball grid array) package." In 2010 5th International Microsystems, Packaging, Assembly and Circuits Technology Conference (IMPACT). IEEE, 2010. http://dx.doi.org/10.1109/impact.2010.5699601.

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Reports on the topic "Gold Compound"

1

Nyongesa, Benjamin Simiyu. Management of a severely curved canal with Proglider and WaveOne gold compounded with a separated instrument. Science Repository OU, January 2019. http://dx.doi.org/10.31487/j.ord.2018.01.003.

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Sisler, Edward C., Raphael Goren, and Akiva Apelbaum. Controlling Ethylene Responses in Horticultural Crops at the Receptor Level. United States Department of Agriculture, October 2001. http://dx.doi.org/10.32747/2001.7580668.bard.

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Ethylene is a plant hormone that controls many plant responses, such as growth, senescence, ripening, abscission and seed germination. Recently, 1-methy- cyclopropene (1-MCP), was shown to bind to ethylene receptor for a certain period of time and prevent ethylene action. The objectives of this research were to synthesize analogues of 1-MCP and test their potency to block the ethylene receptor and inhibit ethylene action. During the course of this project, procedures for synthesis and shipment of the cyclopropene compounds were developed as well assay procedures for each compound were worked out. Thirteen new compounds were synthesized. All of them are structural analogues of 1-MCP, with substitution in the 1-position and a side chain containing 2 to 10 carbons. After preliminary studies, nine promising compounds were selected for in-depth study. The potency of the compounds to inhibit ethylene action was tested on a wide scope of systems like: climacteric fruits (banana, avocado and tomato), the triple response (etiolated peas), and leaf abscission (citrus). As the putative inhibitors are suspected to compete for the site of binding and a competitive type of inhibition could be considered, a high concentration of ethylene (300 m1.L-1) was used to induce ripening and other physiological processes. The tests were conducted under extreme conditions which hasten ripening like treatment and storage at 22 to 25oC. There were fluctuations in the responses as related to the concentrations of the inhibitors. Some required much higher concentration to exert the same effect, while some, when applied at the same concentration, blocked the receptor for a longer period of time than the others. Some fruits and other plant organs responded differently to the same inhibitor, indicating differences in characteristics and availability of the ethylene receptors in the various tissues. The potency of the putative inhibitors was found to be greatly affected by their molecular structural and size. In addition, it was found that treatment with the inhibitor should be given before the onset of ethylene action In the case of fruit, treatment should be carried out before the pre-climacteric stage. Simultaneous treatment with ethylene and the inhibitors reduced the inhibitors' effect. The relationship between ethylene and the inhibitors is of a non-competitive nature. All the fruits treated with the putative inhibitors resumed normal ripening after recovery from the inhibition. This fact is of great importance when considering the inhibitors for practical use. The advantage of using inhibitors of ethylene action over inhibitors of ethylene production lies in the ability of the inhibitors of ethylene action to protect the tissue against both endogenous and exogenous ethylene, thus providing better overall protection. Our findings indicate that 1-MCP and its structural analogues are potent inhibitors of ethylene action capable of providing good protection against endogenous and exogenous ethylene. The fact that the compounds are in a gas phase and are non-phytotoxic, odorless and effective at minute concentrations, renders them promising candidates for commercial use. However, the development of water-soluble inhibitors will expand the potential use of the inhibitors in agriculture.
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Wilson, D., Matthew Kamrath, Caitlin Haedrich, Daniel Breton, and Carl Hart. Urban noise distributions and the influence of geometric spreading on skewness. Engineer Research and Development Center (U.S.), November 2021. http://dx.doi.org/10.21079/11681/42483.

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Statistical distributions of urban noise levels are influenced by many complex phenomena, including spatial and temporal variations in the source level, multisource mixtures, propagation losses, and random fading from multipath reflections. This article provides a broad perspective on the varying impacts of these phenomena. Distributions incorporating random fading and averaging (e.g., gamma and noncentral Erlang) tend to be negatively skewed on logarithmic (decibel) axes but can be positively skewed if the fading process is strongly modulated by source power variations (e.g., compound gamma). In contrast, distributions incorporating randomly positioned sources and explicit geometric spreading [e.g., exponentially modified Gaussian (EMG)] tend to be positively skewed with exponential tails on logarithmic axes. To evaluate the suitability of the various distributions, one-third octave band sound-level data were measured at 37 locations in the North End of Boston, MA. Based on the Kullback-Leibler divergence as calculated across all of the locations and frequencies, the EMG provides the most consistently good agreement with the data, which were generally positively skewed. The compound gamma also fits the data well and even outperforms the EMG for the small minority of cases exhibiting negative skew. The lognormal provides a suitable fit in cases in which particular non-traffic noise sources dominate.
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Pichersky, Eran, Alexander Vainstein, and Natalia Dudareva. Scent biosynthesis in petunia flowers under normal and adverse environmental conditions. United States Department of Agriculture, January 2014. http://dx.doi.org/10.32747/2014.7699859.bard.

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The ability of flowering plants to prosper throughout evolution, and for many crop plants to set fruit, is strongly dependent on their ability to attract pollinators. To that end many plants synthesize a spectrum of volatile compounds in their flowers. Scent is a highly dynamic trait that is strongly influenced by the environment. However, with high temperature conditions becoming more common, the molecular interplay between this type of stress and scent biosynthesis need to be investigated. Using petunia as a model system, our project had three objectives: (1) Determine the expression patterns of genes encoding biosynthetic scent genes (BSGs) and of several genes previously identified as encoding transcription factors involved in scent regulation under normal and elevated temperature conditions. (2) Examine the function of petunia transcription factors and a heterologous transcription factor, PAPl, in regulating genes of the phenylpropanoid/benzenoid scent pathway. (3) Study the mechanism of transcriptional regulation by several petunia transcription factors and PAPl of scent genes under normal and elevated temperature conditions by examining the interactions between these transcription factors and the promoters of target genes. Our work accomplished the first two goals but was unable to complete the third goal because of lack of time and resources. Our general finding was that when plants grew at higher temperatures (28C day/22C night, vs. 22C/16C), their scent emission decreased in general, with the exception of a few volatiles such as vanillin. To understand why, we looked at gene transcription levels, and saw that generally there was a good correlation between levels of transcriptions of gene specifying enzymes for specific scent compounds and levels of emission of the corresponding scent compounds. Enzyme activity levels, however, showed little difference between plants growing at different temperature regimes. Plants expressing the heterologous gene PAPl showed general increase in scent emission in control temperature conditions but emission decreased at the higher temperature conditions, as seen for control plants. Finally, expression of several transcription factor genes decreased at high temperature, but expression of new transcription factor, EOB-V, increased, implicating it in the decrease of transcription of BSGs. The major conclusion of this work is that high temperature conditions negatively affect scent emission from plants, but that some genetic engineering approaches could ameliorate this problem.
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Bano, Masooda. Curricula that Respond to Local Needs: Analysing Community Support for Islamic and Quranic Schools in Northern Nigeria. Research on Improving Systems of Education (RISE), August 2022. http://dx.doi.org/10.35489/bsg-rise-wp_2022/103.

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Involving local communities in school management is seen to be crucial to improving the quality of education in state schools in developing countries; yet school-based management committees remain dormant in most such contexts. Drawing on ethnographic fieldwork with a rich network of community-supported Islamic and Quranic schools in the state of Kano in northern Nigeria—a sub-Saharan African region with very low education indicators, low economic growth, and political and social instability—this paper shows how making school curricula responsive to local value systems and economic opportunities is key to building a strong sense of community ownership of schools. Under community-based school management committees, control over more substantive educational issues—such as the content of school curricula and the nature of aspirations and concepts of a good life that it promotes among the students—remains firmly in the hands of the government education authorities, who on occasion also draw on examples from other countries and expertise offered by international development agencies when considering what should be covered. The paper shows that, as in the case of the urban areas, rural communities or those in less-developed urban centres lose trust in state schools when the low quality of education provided results in a failure to secure formal-sector employment. But the problem is compounded in these communities, because while state schools fail to deliver on the promise of formal-sector employment, the curriculum does promote a concept of a good life that is strongly associated with formal-sector employment and urban living, which remains out of reach for most; it also promotes liberal values, which in the local communities' perception are associated with Western societies and challenge traditional values and authority structures. The outcomes of such state schooling, in the experience of rural communities, are frustrated young people, unhappy with the prospect of taking up traditional jobs, and disrespectful of parents and of traditional authority structures. The case of community support for Islamic and Quranic schools in northern Nigeria thus highlights the need to consider the production of localised curricula and to adjust concepts of a good life to local contexts and economic opportunities, as opposed to adopting a standardised national curriculum which promotes aspirations that are out of reach.
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6

Bano, Masooda. Curricula that Respond to Local Needs: Analysing Community Support for Islamic and Quranic Schools in Northern Nigeria. Research on Improving Systems of Education (RISE), August 2022. http://dx.doi.org/10.35489/bsg-rise-wp_2022/103.

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Abstract:
Involving local communities in school management is seen to be crucial to improving the quality of education in state schools in developing countries; yet school-based management committees remain dormant in most such contexts. Drawing on ethnographic fieldwork with a rich network of community-supported Islamic and Quranic schools in the state of Kano in northern Nigeria—a sub-Saharan African region with very low education indicators, low economic growth, and political and social instability—this paper shows how making school curricula responsive to local value systems and economic opportunities is key to building a strong sense of community ownership of schools. Under community-based school management committees, control over more substantive educational issues—such as the content of school curricula and the nature of aspirations and concepts of a good life that it promotes among the students—remains firmly in the hands of the government education authorities, who on occasion also draw on examples from other countries and expertise offered by international development agencies when considering what should be covered. The paper shows that, as in the case of the urban areas, rural communities or those in less-developed urban centres lose trust in state schools when the low quality of education provided results in a failure to secure formal-sector employment. But the problem is compounded in these communities, because while state schools fail to deliver on the promise of formal-sector employment, the curriculum does promote a concept of a good life that is strongly associated with formal-sector employment and urban living, which remains out of reach for most; it also promotes liberal values, which in the local communities' perception are associated with Western societies and challenge traditional values and authority structures. The outcomes of such state schooling, in the experience of rural communities, are frustrated young people, unhappy with the prospect of taking up traditional jobs, and disrespectful of parents and of traditional authority structures. The case of community support for Islamic and Quranic schools in northern Nigeria thus highlights the need to consider the production of localised curricula and to adjust concepts of a good life to local contexts and economic opportunities, as opposed to adopting a standardised national curriculum which promotes aspirations that are out of reach.
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7

Kwesiga, Victoria, Zita Ekeocha, Stephen Robert Byrn, and Kari L. Clase. Compliance to GMP guidelines for Herbal Manufacturers in East Africa: A Position Paper. Purdue University, November 2021. http://dx.doi.org/10.5703/1288284317428.

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With the global increase in the use of traditional and complementary remedies for the prevention and treatment of illness, the quality and safety of these medicines have become a significant concern for all regulatory authorities. Herbal medicines are the most commonly used form of traditional and complementary medicines in the world and the efficacy and safety of herbal medicines, like conventional medicines, largely depends on their quality from planting to harvesting, preprocessing and final processing. Due to the inherent complexity of herbal medicines, often containing an array of active compounds, the primary processing of herbal medicines has a direct influence on their quality. Quality concerns are the reason why the medicines regulatory agencies insist that manufacturers of medicines strictly follow Good Manufacturing Practices since it is an essential tool to prevent instances of contamination, mix-ups, deviations, failures and errors. However, a strict application of GMP requirements is expensive and would drive the prices of the manufactured products up. As a result, a maturity level grading of facilities is proposed as a way of justifying the costs incurred for manufacturers desiring to reach a broader market and investing in continuous improvement. 36 Good Manufacturing Practice (GMP) inspection reports of local herbal manufacturers conducted by National Drug Authority were analyzed to establish the type and extent of deficiencies to GMP requirements for local herbal manufacturers in Uganda. The different GMP chapters and related sub-parameters constituted the variables used for the analysis of conformity to requirements. The primary outcome variable was the conclusion regarding compliance or noncompliance of the inspected local herbal manufacturing facility. GMP parameters that were frequently defaulted by local herbal manufacturers and the corresponding frequencies were identified. The Pearson Chi-square test was applied independently on each category to find the association that existed between conformity and the questions in each category. Only 22% (8) of the 30 inspected facilities were found to comply with GMP requirements, as per National Drug Authority (NDA) guidelines; while the majority of the facilities, 28 (78%), were found not to comply. Of the facilities inspected, 25 were undergoing GMP inspection for the first time. A total of 1,236 deficiency observations were made in the 36 inspection reports reviewed for the study. The mean for all deficiencies was 34.3, and the standard deviation was 15.829. 91.5% of the facilities did not have mechanisms for a record of market complaints; 80.9% did not meet documentation requirements; 78.9% did not have quality control measures in place, and 65.7% did not meet stores requirements. By encouraging a culture of self/voluntary improvement through the introduction of listing of manufacturers based on a maturity level grading, the National Drug Authority will improve the Herbal Medicines sector as per the mandate of improving the herbal medicine industry. Also, increased sensitization of all relevant stakeholders regarding the requirements for GMP should be intensified.
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Lehotay, Steven J., and Aviv Amirav. Ultra-Fast Methods and Instrumentation for the Analysis of Hazardous Chemicals in the Food Supply. United States Department of Agriculture, December 2012. http://dx.doi.org/10.32747/2012.7699852.bard.

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Original proposal objectives: Our main original goal was to develop ultra-fast methods and instrumentation for the analysis of hazardous chemicals in the food supply. We proposed to extend the QuEChERS approach to veterinary drugs and other contaminants, and conduct fast and ultra-fast analyses using novel 5MB-MS instrumentation, ideally with real samples. Background to the topic: The international trade of agricultural food products is a $1.2 trill ion annual market and growing. Food safety is essential to human health, and chemical residue limits are legislated nationally and internationally. Analytical testing for residues is needed to conduct risk assessments and regulatory enforcement actions to ensure food safety and environmental health, among other important needs. Current monitoring methods are better than ever, but they are still too time-consuming, laborious, and expensive to meet the broad food testing needs of consumers, government, and industry. As a result, costs are high and only a tiny fraction of the food is tested for a limited number of contaminants. We need affordable, ultra-fast methods that attain high quality results for a wide range of chemicals. Major conclusions, solutions and achievements: This is the third BARD grant shared between Prof. Amirav and Dr. Lehotay since 2000, and continual analytical improvements have been made in terms of speed, sample throughput, chemical scope, ease-of-use, and quality of results with respect to qualitative (screening and identification) and quantitative factors. The QuEChERS sample preparation approach, which was developed in conjunction with the BARD grant in 2002, has grown to currently become the most common pesticide residue method in the world. BARD funding has been instrumental to help Dr. Lehotay make refinements and expand QuEChERS concepts to additional applications, which has led to the commercialization of QuEChERS products by more than 20 companies worldwide. During the past 3 years, QuEChERS has been applied to multiclass, multiresidue analysis of veterinary drug residues in food animals, and it has been validated and implemented by USDA-FSIS. QuEChERS was also modified and validated for faster, easier, and better analysis of traditional and emerging environmental contaminants in food. Meanwhile, Prof. Amirav has commercialized the GC-MS with 5MB technology and other independent inventions, including the ChromatoProbe with Agilent, Bruker, and FUR Systems. A new method was developed for obtaining truly universal pesticide analysis, based on the use of GC-MS with 5MB. This method and instrument enables faster analysis with lower LaDs for extended range of pesticides and hazardous compounds. A new approach and device of Open Probe Fast GC-MS with 5MB was also developed that enable real time screening of limited number of target pesticides. Implications, both scientific and agricultural: We succeeded in achieving significant improvements in the analysis of hazardous chemicals in the food supply, from easy sample preparation approaches, through sample analysis by advanced new types of GC-MS and LCMS techniques, all the way to improved data analysis by lowering LaD and providing greater confidence in chemical identification. As a result, the combination of the QuEChERS approach, new and superior instrumentation, and the novel monitoring methods that were developed will enable vastly reduced time and cost of analysis, increased analytical scope. and a higher monitoring rate. This provides better enforcement, an added impetus for farmers to use good agricultural practices, improved food safety and security, increased trade. and greater consumer confidence in the food supply.
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Weinberg, Zwi G., Adegbola Adesogan, Itzhak Mizrahi, Shlomo Sela, Kwnag Jeong, and Diwakar Vyas. effect of selected lactic acid bacteria on the microbial composition and on the survival of pathogens in the rumen in context with their probiotic effects on ruminants. United States Department of Agriculture, January 2014. http://dx.doi.org/10.32747/2014.7598162.bard.

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This research project was performed in context of the apparent probiotic effect of selected lactic acid bacteria (LAB) silage inoculants on the performance of ruminants (improved feed intake, faster live-weight gain, higher milk yields and improved feed efficiency). The overall objective was to find out how LAB affect ruminant performance. The project included several “chapters” as follows: 1. The effect of LAB silage inoculants on the survival of detrimental bacteria in rumen fluid, in vitro study (Weinberg et al., The Volcani Center). An in vitro model was developed to study the interaction between selected LAB and an E. coli strain tagged with green fluorescence protein (GFP) in buffered RF. Results indicated that both LAB inoculants and E. coli survived in the RF for several days; both LAB inoculants and LAB-treated silages did not affect survival of E. coli in rumen fluid in vitro. The effect of feeding baled wheat silages treated with or without three selected LAB silage inoculants on the performance of high-lactating cows (Weinberg et al., The Volcani Center). Treatments included control (no additive), Lacobacillusbuchneri40788 (LB), Lactobacillus plantarumMTD1 40027 (LP) and Pediococcuspentosaceus30168 (PP), each applied at 10⁶ cfu/g FM. The silages were included in the TMR of 32 high milking Holstein cows in a controlled feeding experiment. All baled silages were of good quality. The LB silage had the numerically highest acetic acid and were the most stable upon aerobic exposure. The cows fed the LB silages had the highest daily milk yields, percent milk fat and protein. The microbiome of baled wheat silages and changes during ensiling of wheat and corn (Sela et al., The Volcani Center). Bacterial community of the baled silages was dominated mainly of two genera in total, dominated by Lactobacillus and Clostridium_sensu_stricto_12 with 300 other genera at very low abundance. Fungal community was composed mainly of two genera in total, dominated by Candida and Monascuswith 20 other genera at very low abundance. In addition, changes in the microbiome during ensiling of wheat and corn with and without addition of L. plantarumMTD1 was studied in mini-silos. Overall 236 bacterial genera were identified in the fresh corn but after 3 months Lactobacillus outnumbered all other species by acquiring 95% of relative abundance. The wheat silage samples are still under analysis. The effect of applying LAB inoculants at ensiling on survival of E. coli O157:H7 in alfalfa and corn silages(Adesogan et al., University of Florida). E. coli (10⁵ cfu/g) was applied to fresh alfalfa and corn at ensiling with or without L. plantarumor L. buchneri. The pathogen was added again after about 3 moths at the beginning of an aerobic exposure period. The inoculants resulted in faster decrease in pH as compared with the control (no additives) or E. coli alone and therefore, the pathogen was eliminated faster from these silages. After aerobic exposure the pathogen was not detected in the LAB treated silages, whereas it was still present in the E. coli alone samples. 5. The effect of feeding corn silage treated with or without L. buchnerion shedding of E. coli O157:H7 by dairy cows (Adesogan et al., UFL). BARD Report - Project 4704 Page 2 of 12 Five hundred cows from the dairy herd of the University of Florida were screened for E. coli shedding, out of which 14 low and 13 high shedders were selected. These cows were fed a total mixed ration (TMR) which was inoculated with E. coli O157:H7 for 21 days. The TMR included corn silage treated with or without L. buchneri. The inoculated silages were more stable upon aerobic exposure than the control silages; the silage inoculant had no significant effect on any milk or cow blood parameters. However, the silage inoculant tended to reduce shedding of E. coli regardless of high or low shedders (p = 0.06). 6. The effect of feeding baled wheat silages treated with or without three selected LAB silage inoculants on the rumen microbiome (Mizrahi et al., BGU). Rumen fluid was sampled throughout the feeding experiment in which inoculated wheat silages were included in the rations. Microbial DNA was subsequently purified from each sample and the 16S rRNA was sequenced, thus obtaining an overview of the microbiome and its dynamic changes for each experimental treatment. We observed an increase in OTU richness in the group which received the baled silage inoculated with Lactobacillus Plantarum(LP). In contrast the group fed Lactobacillus buchneri(LB) inoculated silage resulted in a significant decrease in richness. Lower OTU richness was recently associated in lactating cows with higher performance (Ben Shabatet al., 2016). No significant clustering could be observed between the different inoculation treatments and the control in non metric multi-dimentional scaling, suggesting that the effect of the treatments is not the result of an overall modulation of the microbiome composition but possibly the result of more discrete interactions. Significant phylum level changes in composition also indicates that no broad changes in taxa identity and composition occurred under any treatment A more discrete modulation could be observed in the fold change of several taxonomic groups (genus level analysis), unique to each treatment, before and after the treatment. Of particular interest is the LB treated group, in which several taxa significantly decreased in abundance. BARD Report - Project 4704 Page 3 of 12
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TEST ON RESILIENCE CAPACITY OF SELF-CENTERING BUCKLING RESTRAINED BRACE WITH DISC SPRINGS. The Hong Kong Institute of Steel Construction, August 2022. http://dx.doi.org/10.18057/icass2020.p.156.

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The properly constructed buckling restrained braces (BRBs) usually have good ductility and energy dissipation capacity and therefore can be used in braced steel frames. However, large residual plastic deformation of the BRBs deteriorates their resilience capacity and hence results in large residual deformation of the buckling restrained braced steel frames (BRBFs) under large drifts. To reduce the residual deformation of BRB while keeping good ductility and energy dissipation capacity, a new self-centering buckling restrained brace (SCBRB), letting both BRB part and self-centering part work in parallel, is proposed. The self-centering capacity of SCBRB is provided by a combination of pre-compressed disc springs, which provides restoring forces and facilitates reduction of the residual deformation of the BRB. The BRB is composed of a core steel plate brace, a restraining member formed by the circular steel tube filled with mortar, and debonding materials between them. By quasi-static tests, one self-centering buckling restrained brace specimen (SCBRB) and one pure BRB specimen were tested to mainly examine the constructional details and hysteretic behavior of SCBRB. The material and configuration details of core steel plate brace in both the SCBRB and the pure BRB are the same for comparison. The test results show that, compared with the pure BRB which still exhibits large residual deformation, the SCBRB presents a flag-shape hysteretic performance and its residual deformation decreases significantly. The hysteretic curves of both the SCBRB and the pure BRB are stable before tension fracture of plate brace due to low cyclic fatigue, and the other components remained intact.
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