111,839 research outputs found
Indolylarylsulfones, a fascinating story of highly potent human immunodeficiency virus type 1 non-nucleoside reverse transcriptase inhibitors
No full textIndolylarylsulfones are a potent class of human immunodeficiency virus type 1 non-nucleoside reverse transcriptase inhibitors. In this review, the structure activity relationship (SAR) studies to improve the profile of sulfone L-737,126 discovered by Merck AG have been analysed with focus on introduction of the 3',5'-dimethyl groups at the 3-phenylsulfonyl moiety, the 2-hydroxyethyl tail at the indole-2-carboxamide nitrogen, coupling of the carboxamide nitrogen with one or two glycinamide and alaninamide units, a fluorine atom at position 4 of the indole ring and correlation between configuration of the asymmetric centre and linker length. IAS derivatives look like promising drug candidates for the treatment of AIDS and related infections in combination with other antiretroviral agents
MACCHINA PER ANALISI CHIMICA COMPRENDENTE LA COMBINAZIONE DELLA SPETTROMETRIA DI MASSA A IONIZZAZIONE ELETTRONICA CON LA CROMATOGRAFIA LIQUIDA
No full textTyrosol and Hydroxytyrosol Determination in Extra Virgin Olive Oil with Direct Liquid Electron Ionization-Tandem Mass Spectrometry
No full textExtra virgin olive oil (EVOO) is one of the main ingredients of the Mediterranean diet. It is claimed as a functional food for its unique content of health-promoting compounds. Tyrosol (Tyr), Hydroxytyrosol (Htyr), and their phenolic derivatives present in EVOO show beneficial properties, and their identification and quantification, both in their free form and after the hydrolysis of more complex precursors, are important to certify its quality. An alternative method for quantifying free and total Tyr and Htyr in EVOO is presented using an LC–MS interface based on electron ionization (EI), called liquid electron ionization (LEI). This method requires neither sample preparation nor chromatography; the sample is diluted and injected. The selectivity and sensitivity were assessed in multiple reaction monitoring mode (MRM), obtaining confirmation and quantification in actual samples ranging from 5 to 11 mg/Kg for the free forms and from 32 to 80 mg/Kg for their total amount after hydrolysis. Two MS/MS transitions were acquired for both compounds using the Q/q ratios as confirmatory parameters. Standard addition calibration curves demonstrated optimal linearity and negligible matrix effects, allowing a correct quantification even without expensive and difficult to find labeled internal standards. After several weeks of operation, the system’s repeatability was excellent, with an intraday RSD (%) spanning from five to nine and an interday RSD (%) spanning from 9 to 11
author-bios-SRD-19-0063.R1 – Supplemental material for The Network Structure of Police Misconduct
No full textSupplemental material, author-bios-SRD-19-0063.R1 for The Network Structure of Police Misconduct by George Wood, Daria Roithmayr and Andrew V. Papachristos in Socius</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Determination of Selected Endocrine Disrupting Compounds in Human Fetal and Newborn Tissues by GC-MS
No full textEndocrine disrupting compounds (EDCs) include
organochlorine pesticides (OCPs), organophosphate pesticides
(OPPs), carbamate pesticides, and plasticizers, such as
bisphenol A (BPA). They persist in the environment because
of their degradation resistance and bioaccumulate in the body
tissues of humans and other mammals. Many studies are
focused on the possible correlation between in utero exposure
to EDCs and adverse health hazards in fetuses and newborns.
In the last decade, environmental pollution has been considered
a possible trigger for Sudden Infant Death Syndrome
(SIDS) and Sudden Intrauterine Unexplained Death
Syndrome (SIUDS), the most important death-causing syndromes
in fetuses and newborns in developed countries. In
this work, a rapid and sensitive analytical method was developed
to determine the level of OCPs and OPPs, carbamates,
and phenols in human fetal and newborn tissues (liver and
brain) and to unveil the possible presence of non-targeted
compounds. The target analytes where selected on the basis
of their documented presence in the Trentino-Alto Adige
region, an intensive agricultural area in northern Italy. A
liquid-solid extraction procedure was applied on human and
animal tissues and the extracts, after a solid phase extraction
(SPE) clean-up procedure, were analyzed by gas chromatography
coupled to a quadrupole mass spectrometric detector
(GC-qMS). A GC-TOFMS (time-of-flight) instrument, because
of its higher full-scan sensitivity, was used for a parallel
detection of non-targeted compounds. Method validation included accuracy, precision, detection, and quantification
limits (LODs; LOQs), and linearity response using swine liver
and lamb brain spiked at different concentrations in the range
of 0.4–8000.0 ng/g. The method gave good repeatability and
extraction efficiency. Method LOQs ranged from 0.4–4.0 ng/g
in the selected matrices. Good linearity was obtained over four
orders of magnitude starting from LOQs. Isotopically labeled
internal standards were used for quantitative calculations. The
method was then successfully applied to the analysis of liver
and brain tissues from SIUDS and SIDS victims coming from
the above mentioned region
Arylsulfone-based HIV-1 non-nucleoside reverse transcriptase inhibitors
No full textHIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs) represent one of the most significant classes of drugs for the treatment of AIDS/HIV infection. Over the past two decades several potent arylsulfone-based HIV-1 NNRTIs and related analogs have been developed. This review provides an essential overview of the structure-activity relationships of the arylsulfone-based HIV-1 NNRTIs. Furthermore, structural information useful for the design and development of new sulfur containing NNRTIs with enhanced antiretroviral activity against HIV-1 wild type and clinically relevant drug resistant HIV-1 mutant strains will be discussed. © 2013 Future Science Ltd
A new, simple, and high-yielding synthesis of 2,9-Dihydro-1 H- pyrido[3,4- b ]indol-1-ones
No full textA new, simple, and high-yielding method was developed to prepare 2,9-dihydro-1H-pyrido[3,4-b]indol-1-ones by selective cyclization of the appropriate N-(2,2-dimethoxyethyl)-1H-indole-2-carboxamide in polyphosphoric acid at 110 °C for 30 minutes. The reaction yield was strongly dependent on the acid used. The method was less affected by the presence of electron-donating and -withdrawing substituents at 5-position of the indole nucleus. © Georg Thieme Verlag Stuttgart, New York
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Microfluidic water-assisted trap focusing method for ultra-large volume injection in reversed-phase nano-liquid chromatography coupled to electron ionization tandem-mass spectrometry
No full textHerein we present an efficient, column-switching method that relies on a custom-made T-union passive diffusion micromixer to assist water dilution and promote trap solute focusing of a high sample volume dissolved in pure organic solvent using a 0.075 mm i.d. nano-LC column. This method allows injecting 20 μL (or higher) of sample volume, speeding up the analysis time, with a 400-fold increase of the limits of quantitation for selected compounds. Five pesticides in different media were used as model compounds, and the analyses were carried out with a triple quadrupole mass spectrometer equipped with a Liquid Electron Ionization (LEI) LC-MS interface working in multiple reaction monitoring (MRM) mode. The system microfluidics were investigated using COMSOL modeling software. Robustness of the entire system was evaluated using a post-extraction addition soil extracts with limits of detection values spanning from 0.10 to 0.45 μg/L. Reproducible results in terms of peak area, peak shape, and retention times were achieved in soil matrix. Repeatability test on peak area variations were lower than 10%
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