Instantaneous Mass/Charge Ratio F(dm/dQ) of the Voltammetric Generation and Characterization of Poly-(Neutral Red) Conducting Films

2019 ◽  
Vol 2 (16) ◽  
pp. 11-18
Author(s):  
Francisco Vicente ◽  
Jeronimo Agrisuelas ◽  
Claude Gabrielli ◽  
Joan Gregori ◽  
Jose Juan Garcia-Jareño ◽  
...  
Keyword(s):  
1971 ◽  
Vol 11 (50) ◽  
pp. 328
Author(s):  
BJ Crack ◽  
RF Isbell

Morphological and chemical data are presented for neutral red duplex soils (Dr2.12) derived from granodiorite and diorite in north-eastern Queensland under a strongly seasonal summer rainfall. Mean annual totals range from about 24 inches (610 mm) to nearly 40 inches (1000 mm). The soils have slightly acid loamy A, horizons which overlie structured red clay B horizons of slightly acid to neutral reaction. C horizons containing much weathered rock occur at 50-70 cm and continue to depths exceeding two metres. Profiles show a consistent trend for many chemical properties ; a particular feature being the relatively high accumulation of phosphorus in the C horizon. Certain chemical analyses of surface soils are sufficiently consistent within and between sites to provide a broad regional characterization of plant nutrient status. The soils of the Charters Towers region have low nitrogen, organic carbon, and available phosphorus contents but potassium levels are moderate. Home Hill-Bowen soils are more variable but indicate generally higher fertility levels.


2015 ◽  
Vol 140 (6) ◽  
pp. 532-541 ◽  
Author(s):  
Muhammad Mansoor Javaid ◽  
Manish Bhan ◽  
Jodie V. Johnson ◽  
Bala Rathinasabapathi ◽  
Carlene A. Chase

There has been increasing interest in recent years in sunn hemp (Crotalaria juncea), as a leguminous cover crop and green manure, for weed and pest management and improving soil health. Aqueous extracts and ground shoot tissue have previously been demonstrated to be phytotoxic. To further explore its allelopathic potential, bioassays and chemical characterization of water-soluble eluates of sunn hemp were undertaken. Lettuce (Lactuca sativa) radicle growth inhibition was conducted with aqueous eluates from thinly sliced sunn hemp leaves, stems, and seeds, and all three tissues exhibited the inhibitory potential. Fourteen accessions originating from the United States, India, Brazil, South Africa, Pakistan, and Nigeria had water-soluble allelochemicals in leaves, suggesting that allelopathic potential is widely distributed in this species. The highest level of inhibitory potential was found in accession IN-86. Further characterization of IN-86 leaf eluates indicated that the inhibitory compound(s) was/were not soluble in chloroform, but was/were stable when boiled for 15 minutes and resistant to 1 n HCl. Binding and elution from AG-1(OH−) ion-exchange resin also were observed. An analysis of leaf eluates of IN-86 using high-performance liquid chromatography (HPLC) followed by mass spectrometry (MS) showed the presence of a compound with a mass-to-charge ratio of 148, consistent with the spectrum for hydroxynorleucine, a phytotoxic nonprotein amino acid previously reported in seeds of C. juncea. However, its low concentration (<1 μg·mL−1) suggested that other components of the eluate were responsible for the observed allelopathic effect. The results indicate the feasibility for development of weed control strategies using allelochemicals derived from sunn hemp biomass of select genotypes IN-86, NG-71, and BR-20 from India, Nigeria, and Brazil, respectively.


Pathogens ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 906
Author(s):  
Saksakon Paratsaphan ◽  
Saengduen Moonsom ◽  
Onrapak Reamtong ◽  
Sittiruk Roytrakul ◽  
Vanaporn Wuthiekanun ◽  
...  

Leptospirosis is a zoonotic infectious disease caused by pathogenic Leptospira species. Virulence proteins have been shown to be key determinants of the pathogenesis of pathogenic Leptospira. A specific peptide at a mass-to-charge ratio of 7000 Da was identified in Leptospira whole cells using matrix-assisted laser/desorption ionization time-of-flight (MALDI-TOF) mass spectrometry. This peptide was specifically present in pathogenic Leptospira and in clinical isolates. We report here the characterization of this specific peptide using a proteomics approach. This peptide was significantly matched to a hypothetical conserved L. interrogans protein (LA2458) with a calculated molecular weight of 7140.136 Da containing a tellurite-resistance domain at its C terminus (TerB-C). The amino acid sequences revealed the presence of hydrophobic transmembrane portions and two linear B-cell epitopes. Despite its low abundance, this synthetic peptide demonstrated dose-dependent cytotoxicity toward African green monkey kidney (Vero) cells via the apoptosis pathway. The concentration of the peptide 100 µM induced about 50% of cell death after a 24 h exposure. This peptide could be useful for the diagnosis of leptospirosis and the study of pathogenesis.


2019 ◽  
Vol 12 (10) ◽  
pp. 5535-5545 ◽  
Author(s):  
Xuan Zhang ◽  
Haofei Zhang ◽  
Wen Xu ◽  
Xiaokang Wu ◽  
Geoffrey S. Tyndall ◽  
...  

Abstract. We demonstrate the capability of the ion mobility mass spectrometry (IMS-MS) for molecular characterization of reactive and short-lived alkyl nitrates (ANs) in atmospheric aerosols. We show significantly enhanced sensitivity towards the intact molecules of ANs by ultimately 2 orders of magnitude with the addition of inorganic anions such as chloride and nitrate to the negative electrospray to promote the ion adduct formation. This approach enables the measurement of ANs that have a low tendency to form molecular ions on their own with an improved limit of detection in the range of 0.1 to 4.3 µM. Molecular identities of the ANs are well constrained by the developed correlation between the collision cross section and mass-to-charge ratio, which provides a two-dimensional separation of the -ONO2-containing compounds on the basis of their molecular size and geometry. Structural information of the nitrate molecules is further probed by the identification of characteristic fragments produced from the collision-induced dissociation of parent AN adducts. Application of the IMS-MS technique is exemplified by the identification of hydroxy nitrates in secondary organic aerosols produced from the photochemical oxidation of isoprene.


Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3220
Author(s):  
Gabriela Broncová ◽  
Tereza Slaninová ◽  
Miroslava Trchová ◽  
Vadim Prokopec ◽  
Pavel Matějka ◽  
...  

This study is focused on the visualization of latent fingerprints on brass surfaces using the method of electrochemical deposition of a polymer film based on poly(neutral red) (PNR). The experiment included (i) optimization of conditions of electrochemical deposition of PNR on brass surfaces, (ii) ATR-FTIR spectroscopic characterization of PNR-modified substrates, and (iii) identification of characteristic details on visualized fingerprints on fired brass cartridges. For electrochemical visualization, it is necessary to keep in mind both kind and “story” substrates. Experimental findings showed that electrochemical visualization carried out on brass plates is a step forward before known findings described in the literature and gives simultaneously a new approach for criminalists in the fight against crime.


2019 ◽  
Author(s):  
Xuan Zhang ◽  
Haofei Zhang ◽  
Wen Xu ◽  
Geoffrey S. Tyndall ◽  
John J. Orlando ◽  
...  

Abstract. We demonstrate the capability of the Ion Mobility Mass Spectrometry (IMS-MS) for molecular characterization of reactive and short-lived alkyl nitrates (ANs) in atmospheric aerosols. We show significantly enhanced production of ion adducts from a selection of alkyl nitrates by clustering with inorganic anions such as chloride and nitrate during negative electrospray, a special chemical ionization mechanism in the condensed phase. This approach enables the detection of ANs that have low tendency to form molecular ions on their own by electrospray ionization. Molecular identity of each AN adduct is well constrained by the developed collision cross section vs. mass to charge ratio correlation, which provides a two-dimensional separation of the –ONO2 containing compounds on the basis of their molecular size and geometry. Structural information of AN molecules is further probed by the identification of characteristic fragments produced from the collision induced dissociation of parent AN adducts. Application of the IMS-MS technique is exemplified by the identification of hydroxy nitrates in secondary organic aerosols produced from isoprene photochemistry.


1995 ◽  
Vol 30 (12) ◽  
pp. 1765-1767 ◽  
Author(s):  
Christopher J. Smith ◽  
Sarah Y. Chang ◽  
Edward S. Yeung

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