6 research outputs found
Unbiased Scanning Method and Data Banking Approach Using Ultra-High Performance Liquid Chromatography Coupled with High-Resolution Mass Spectrometry for Quantitative Comparison of Metabolite Exposure in Plasma across Species Analyzed at Different Dates
An
unbiased scanning methodology using ultra high-performance liquid
chromatography coupled with high-resolution mass spectrometry was
used to bank data and plasma samples for comparing the data generated
at different dates. This method was applied to bank the data generated
earlier in animal samples and then to compare the exposure to metabolites
in animal versus human for safety assessment. With neither authentic
standards nor prior knowledge of the identities and structures of
metabolites, full scans for precursor ions and all ion fragments (AIF)
were employed with a generic gradient LC method to analyze plasma
samples at positive and negative polarity, respectively. In a total
of 22 tested drugs and metabolites, 21 analytes were detected using
this unbiased scanning method except that naproxen was not detected
due to low sensitivity at negative polarity and interference at positive
polarity; and 4′- or 5-hydroxy diclofenac was not separated
by a generic UPLC method. Statistical analysis of the peak area ratios
of the analytes versus the internal standard in five repetitive analyses
over approximately 1 year demonstrated that the analysis variation
was significantly different from sample instability. The confidence
limits for comparing the exposure using peak area ratio of metabolites
in animal plasma versus human plasma measured over approximately 1
year apart were comparable to the analysis undertaken side by side
on the same days. These statistical analysis results showed it was
feasible to compare data generated at different dates with neither
authentic standards nor prior knowledge of the analytes
Evaluation of the plasticity of soybean (Glycine max (L.) Merrill) under effect of variability of space arrangements.
O presente experimento teve por objetivos, avaliar a maneira como a planta de soja se adapta a diferentes arranjos espaciais (plasticidade) e identificar o arranjo espacial que melhor represente ou possibilite associar o manejo do cultivar MG/BR 46 (Conquista) com alta produtividade agrícola. O experimento foi conduzido em área experimental da Escola Superior de Agricultura "Luiz de Queiroz" (ESALQ/USP), no município de Piracicaba - SP, durante o ano agrícola de 2001/2002. Os tratamentos constaram de diferentes arranjos espaciais, variando-se e combinando-se 6 níveis do fator espaçamento entre linhas (0,20; 0,30; 0,40; 0,50; 0,60 e 0,70 m) e 5 níveis do fator densidade de plantas na linha visando as populações de 70.000; 140.000; 210.000; 280.000 e 350.000 plantas/ha, totalizando 30 tratamentos, delineados em blocos ao acaso com parcelas subdivididas e com três repetições. As características avaliadas foram: tempo de fechamento de entrelinhas; índice de área foliar; altura final de planta; altura de inserção da primeira vagem; número de ramificações; número de vagens por planta; número de grãos por planta; grau de acamamento; massa de 1000 sementes e produtividade agrícola. As principais conclusões são: a) o cultivar MG/BR 46 (Conquista), cultivado em linhas espaçadas entre si de 0,20 a 0,60 m, apresenta índice de área foliar máximo no estádio fenológico correspondente ao início da granação das vagens (R5); b) o número de vagens é o mais importante componente da produção por planta, por ser diretamente influenciado pelo arranjo populacional das plantas na área de produção; c) o cultivar MG/BR 46 (Conquista) apresenta ampla plasticidade, ajustando os seus componentes de produção aos diferentes arranjos espaciais, sem que ocorram significativas diferenças de produtividade; d) para cada combinação entre o espaçamento entre linhas e a densidade de plantas na linha existe uma população de plantas mais bem ajustada, que possibilita maior produtividade de grãos.This research had as purposes to evaluate the soybean plant adaptations (plasticity) to different space arrangements and identify the best space arrangements for higher yields of cultivar MG/BR 46 (Conquista). The experiment was carried out at the experimental fields of Escola Superior de Agricultura "Luiz de Queiroz" (USP/ESALQ), São Paulo State University, in Piracicaba-SP, during the 2001/2002 growing season. The 30 treatments consisted of different space arrangements, combining 6 row spacing (0,20; 0,30; 0,40; 0,50; 0,60; 0,70 m) with 5 different population (70.000; 140.000; 210.000; 280.000; 350.000 plants/ha), in a complete randomized blocks design with subdivided plots and three replications. The evaluated characteristics were: time to achieve closed canopy; leaf area index; final plant height; height of the first pod; number of branches per plant; number of pods per plant; number of grains per plant; lodging; mass of 1,000 grains and yield. The main conclusions are: a) the cultivar MG/BR - 46 (Conquista) cultivated under 0,20 to 0,60 m row spacing shows a leaf area index maximum at the begging of seed-filling stage (R5); b) the number of pods is the best related component to yield per plant, being directly influenced by plant population; c) the cultivar MG/BR - 46 (Conquista) presents wide plasticity, adjusting its yield components to the different space arrangements, without significant yield changes; d) for each row spacing there is a better plant population to achieve higher yield
Substrate-Mediated C–C and C–H Coupling after Dehalogenation
Intermolecular
C–C coupling after cleavage of C–X
(mostly, X = Br or I) bonds has been extensively studied for facilitating
the synthesis of polymeric nanostructures. However, the accidental
appearance of C–H coupling at the terminal carbon atoms would
limit the successive extension of covalent polymers. To our knowledge,
the selective C–H coupling after dehalogenation has not so
far been reported, which may illuminate another interesting field
of chemical synthesis on surfaces besides <i>in situ</i> fabrication of polymers, i.e., synthesis of novel organic molecules.
By combining STM imaging, XPS analysis, and DFT calculations, we have
achieved predominant C–C coupling on Au(111) and more interestingly
selective C–H coupling on Ag(111), which in turn leads to selective
synthesis of polymeric chains or new organic molecules
Toward Tunable Electroluminescent Devices by Correlating Function and Submolecular Structure in 3D Crystals, 2D-Confined Monolayers, and Dimers
The synthesis of new Pt(II) complexes
bearing tailored cyclometalated C^N*N^C luminophores is reported along
with their photophysical properties. The emission of the monomeric
species can be blue shifted upon formal isosteric replacement of two
C–H units by N atoms at the two cyclometalating rings. Their
remarkable stability upon sublimation was demonstrated by means of
scanning tunneling microscopy, which also revealed a defined self-assembly
behavior leading to supramolecular arrays, showing a 3-fold symmetry
in 2D-confined monolayers. The supramolecular organization is driven
by van der Waals interactions of the side chains and does not depend
on the nature of the luminophores, as also observed in the crystalline
phases showing no significant Pt–Pt interactions in 3D. Conversely,
the luminescence properties in glassy matrices at 77 K and in amorphous
solids are indicative of intermolecular interactions with sizable
intermetallic coupling, which was demonstrated by reproducing the
emission spectra of dimeric species by means of (TD)DFT calculations.
The tendency toward aggregation was also traceable by cyclic voltammetry,
whereas thermogravimetric analyses confirmed their stability. Solution-processed
and vacuum-deposited OLED devices showed a concentration-dependent
electroluminescence that red shifts with increasing doping ratios.
Due to the stability of the complexes, solution-processed and vacuum-deposited
devices showed identical electroluminescence spectra. Besides favoring
aggregation, introduction of two N atoms has a detrimental effect
on the device performance, due to the prolonged excited-state lifetimes
favoring triplet–triplet annihilation
Toward Tunable Electroluminescent Devices by Correlating Function and Submolecular Structure in 3D Crystals, 2D-Confined Monolayers, and Dimers
The synthesis of new Pt(II) complexes
bearing tailored cyclometalated C^N*N^C luminophores is reported along
with their photophysical properties. The emission of the monomeric
species can be blue shifted upon formal isosteric replacement of two
C–H units by N atoms at the two cyclometalating rings. Their
remarkable stability upon sublimation was demonstrated by means of
scanning tunneling microscopy, which also revealed a defined self-assembly
behavior leading to supramolecular arrays, showing a 3-fold symmetry
in 2D-confined monolayers. The supramolecular organization is driven
by van der Waals interactions of the side chains and does not depend
on the nature of the luminophores, as also observed in the crystalline
phases showing no significant Pt–Pt interactions in 3D. Conversely,
the luminescence properties in glassy matrices at 77 K and in amorphous
solids are indicative of intermolecular interactions with sizable
intermetallic coupling, which was demonstrated by reproducing the
emission spectra of dimeric species by means of (TD)DFT calculations.
The tendency toward aggregation was also traceable by cyclic voltammetry,
whereas thermogravimetric analyses confirmed their stability. Solution-processed
and vacuum-deposited OLED devices showed a concentration-dependent
electroluminescence that red shifts with increasing doping ratios.
Due to the stability of the complexes, solution-processed and vacuum-deposited
devices showed identical electroluminescence spectra. Besides favoring
aggregation, introduction of two N atoms has a detrimental effect
on the device performance, due to the prolonged excited-state lifetimes
favoring triplet–triplet annihilation
Toward Tunable Electroluminescent Devices by Correlating Function and Submolecular Structure in 3D Crystals, 2D-Confined Monolayers, and Dimers
The synthesis of new Pt(II) complexes
bearing tailored cyclometalated C^N*N^C luminophores is reported along
with their photophysical properties. The emission of the monomeric
species can be blue shifted upon formal isosteric replacement of two
C–H units by N atoms at the two cyclometalating rings. Their
remarkable stability upon sublimation was demonstrated by means of
scanning tunneling microscopy, which also revealed a defined self-assembly
behavior leading to supramolecular arrays, showing a 3-fold symmetry
in 2D-confined monolayers. The supramolecular organization is driven
by van der Waals interactions of the side chains and does not depend
on the nature of the luminophores, as also observed in the crystalline
phases showing no significant Pt–Pt interactions in 3D. Conversely,
the luminescence properties in glassy matrices at 77 K and in amorphous
solids are indicative of intermolecular interactions with sizable
intermetallic coupling, which was demonstrated by reproducing the
emission spectra of dimeric species by means of (TD)DFT calculations.
The tendency toward aggregation was also traceable by cyclic voltammetry,
whereas thermogravimetric analyses confirmed their stability. Solution-processed
and vacuum-deposited OLED devices showed a concentration-dependent
electroluminescence that red shifts with increasing doping ratios.
Due to the stability of the complexes, solution-processed and vacuum-deposited
devices showed identical electroluminescence spectra. Besides favoring
aggregation, introduction of two N atoms has a detrimental effect
on the device performance, due to the prolonged excited-state lifetimes
favoring triplet–triplet annihilation