Search results for "PIP"
showing 10 items of 1156 documents
Analysis of pharmaceutical preparations containing antihistamine drugs by micellar liquid chromatography
2005
Rapid chromatographic procedures for analytical quality control of pharmaceutical preparations containing antihistamine drugs, alone or together with other kind of compounds are proposed. The method uses C18 stationary phases and micellar mobile phases of cetyltrimethylammonium bromide (CTAB) with either 1-propanol or 1-butanol as organic modifier. The proposed procedures allow the determination of the antihistamines: brompheniramine, chlorcyclizine, chlorpheniramine, diphenhydramine, doxylamine, flunarizine, hydroxyzine, promethazine, terfenadine, tripelennamine and triprolidine, in addition to caffeine, dextromethorphan, guaifenesin, paracetamol and pyridoxine in different pharmaceutical …
Modulation of N···I and +N−H···Cl−···I Halogen Bonding: Folding, Inclusion, and Self-Assembly of Tri- and Tetraamino Piperazine Cyclophanes
2010
The acidity of the crystallization conditions was successfully employed in modulating the balance between the robust intramolecular hydrogen bonding (HB) and intermolecular halogen bonding (XB) observed in large tri- (1) and tetraamino (2) piperazine cyclophanes. A careful crystallization of the title XB acceptor cyclophanes with a strong bidentate XB donor 1,4-diiodotetrafluorobenzene (F4DIB) from CHCl3:MeOH, dimethylformamide (DMF), or HCl:H2O:EtOH resulted in X-ray quality crystals of 1·F4DIB, 2@DMF, 2·2@F4DIB, [1H3]Cl3·(F4DIB)6, and [2H6]Cl6·(F4DIB)2. The intramolecular hydrogen bonding pattern in 1 and 2 was retained in neutral protic and aprotic solvents, and regular N−H···N hydrogen …
Stereoselective Access to Fluorinated and Non-fluorinated Quaternary Piperidines: Synthesis of Pipecolic Acid and Iminosugar Derivatives
2012
The preparation of optically pure quaternary piperidines, both fluorinated and non-fluorinated, has been achieved from a chiral imino lactone derived from (R)-phenylglycinol. In the case of the fluorinated derivatives, the addition of (trifluoromethyl)trimethylsilane (TMSCF(3)) followed by iodoamination and migration of the CF(3) group allowed access to four derivatives of α-(trifluoromethyl)pipecolic acid. A theoretical study of the CF(3)-group rearrangement has been carried out to help establish the reaction mechanism of this uncommon transformation. Moreover, a route to trifluoromethyl-substituted iminosugars was also developed through the diastereoselective dihydroxylation of suitable s…
Parallel macro pipelining on the intel SCC many-core computer
2013
In this paper we present how Intel's Single-Chip-Cloud processor behaves for parallel macro pipeline applications. Subsets of the SCC's available cores can be arranged as a pipeline where each core processes one stage of the overall workload. Each of the independent cores processes a small part of a larger task and feeds the following core with new data after it finishes its work. Our case-study is a parallel rendering system which renders successive images and applies different filters on them. On normal graphics adapters this is usually done in multiple cycles, we do this in a single pipeline pass. We show that we can achieve a significant speedup by using multiple parallel pipelines on t…
Geo-hazards of the San Vito peninsula offshore (southwestern Tyrrhenian Sea)
2021
Geomorphological Tools for Mapping Natural Hazards.-- 12 pages, 7 figures, supplemental material https://doi.org/10.1080/17445647.2020.1866703.-- Software: The geomorphological main map and the Figures in the text were compiled using GLOBAL MAPPER, Surfer and Quantum-G GIS Software and redesigned to print with Adobe Illustrator
Heat Pipe-Mediated Control of Fast and Highly Exothermal Reactions
2011
The synthesis of 1-ethyl-3-methylimidazolium ethyl-sulfate ([EMIM]EtSO4) from 1-methyl-imidazole and diethyl sulfate suffers from highly exothermal behavior. Once the activation energy barrier is reached (EA = 89 kJ mol–1), the bimolecular reaction accelerates with a high reaction enthalpy (ΔH = −130 kJ mol–1).(1-3) The excess of heat has to be concurrently dissipated to avoid hot spots or thermal runaways. Depending on the volume flow velocity of the reactants and the applied reactor temperature, the reaction zone can be shifted inside the reactor from the inlet to the outlet and vice versa. Therefore, a sophisticated thermal control, oscillating between providing activation energy and int…
Identification in the rat brain of a set of nuclear proteins interacting with H1° mRNA
2012
Synthesis of H1° histone, in the developing rat brain, is also regulated at post-transcriptional level. Regulation of RNA metabolism depends on a series of RNA-binding proteins (RBPs); therefore, we searched for H1° mRNA-interacting proteins. With this aim, we used in vitro transcribed, biotinylated H1° RNA as bait to isolate, by a chromatographic approach, proteins which interact with this mRNA, in the nuclei of brain cells. Abundant RBPs, such as heterogeneous nuclear ribonucleoprotein (hnRNP) K and hnRNP A1, and molecular chaperones (heat shock cognate 70, Hsc70) were identified by mass spectrometry. Western blot analysis also revealed the presence of cold shock domain-containing protein…
Strukturuntersuchungen von polyamiden aus cyclischen dicarbonsäuren und piperazin durch direkten abbau im massenspektrometer
1977
Polyamide aus 1,2-Cyclobutan-, 1,2-Cyclopentan- und 1,2-Cyclohexandicarbonsaure und Piperazin wurden direkt in der Ionenquelle eines Massenspektrometers pyrolysiert. Die hohe Empfindlichkeit der massenspektrometrischen Methode erlaubt, bei Abbauraten von ca. 1%/min zu pyrolysieren und dadurch selektive thermische Abbaumechanismen neben den Fragmentierungsreaktionen nachzuweisen. Durch thermischen Abbau werden dabei Oligomere mit Piperazinendgruppen sowie gesattigte und ungesattigte Cyclobutan-, -pentan- und -hexanendgruppen gebildet. Polyamides of 1,2-cyclobutane-, 1,2-cyclopentane- and 1,2-cyclohexane-dicarboxylic acid and piperazine were pyrolyzed directly in the ion source of a mass spec…
Fly-and-Forage Strategy in the Bat Pipistrellus nathusii During Autumn Migration
2012
Populations of Pipistrellus nathusii (Nathusius's bat), an insectivorous aerial-hawking species that breeds in north-eastern Europe, perform long-distance migrations between breeding sites and hibernation areas in central and southern Europe. The feeding strategy of migrating P. nathusii was investigated in Latvia on the east coast of the Baltic Sea, exploring evidence for and against two non-mutually exclusive predictions that i) the bats feed shortly after dusk at highest aerial insect activity and continue to migrate thereafter or ii) apply a ‘fly-and-forage’ strategy and frequently interrupt their migration flight to feed. Echolocation calls and feeding buzzes of P. nathusii were record…
Granular chains for the assessment of thermal stress in slender structures
2015
Slender beams subjected to compressive stress are common in civil and mechanical engineering. The rapid in-situ measurement of this stress may prevent structural anomalies. In this paper, we describe the coupling mechanism between highly nonlinear solitary waves (HNSWs) propagating along an L-shaped granular system and a beam in contact with the granular medium. We evaluate the use of HNSWs as a tool to measure stress in thermally loaded structures and to estimate the neutral temperature, i.e. the temperature at which this stress is null. We investigated numerically and experimentally one and two L-shaped chains of spherical particles in contact with a prismatic beam subjected to heat. We f…