Molecular docking,experimental FT-IR spectra,UV–Vis spectra,vibrational analysis,electronic properties,Fukui function analysis of a potential bioactive agent – Proflavine

Proflavine, having the molecular formula C₁₃H₁₁N₃, is a well-known urinary antiseptic and anticancer medication (3,6-diaminoacridine). In this communication, Quantum chemical computations of Proflavine's geometry have been performed and examined in the ground state. The optimized structure and wavenumbers of the molecule's vibrational bands were investigated using the DFT/B3LYP method and 6–311G (d, p) as the basis set. The calculated vibrational frequencies are compared to experimental IR spectra. The link between thermodynamic characteristics and temperature has been studied. The computed IR frequencies correlate well with the experiments, as indicated by the correlation factor (R² = 0.99). The UV spectra of the title molecule are calculated by using Time Dependent Density Functional Theory (TD-DFT). The molecule's interactions with other species were described using an analysis of a HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital). Natural bond orbitals (NBO) analysis was used to investigate intramolecular and intermolecular hydrogen bonding and their second-order stabilization energies and conjugative and hyperconjugative interactions. By computing the first hyperpolarizability, nonlinear optical (NLO) analysis was utilized to explore the molecule's nonlinear optical properties.     

Quantitative analysis of geraniol,nerol, linalool,and α-terpineol in wine

A mixture of [(2)H(7)]-geraniol, [(2)H(7)]-nerol, [(2)H(7)]-linalool and [(2)H(7)]-alpha-terpineol was prepared for use as internal standards in a rapid and accurate analytical method, employing gas chromatography-mass spectrometry (GC/MS), to determine the concentration of geraniol, nerol, linalool and alpha-terpineol in wine. The method avoids the possible formation, degradation and interconversion of these compounds during their analysis.     

Density and wave function analysis of actinide complexes: what can fuzzy atom, atoms-in-molecules, Mulliken, Lowdin, and natural population analysis tell us?

Recent advances in computational methods have made it possible to calculate the wave functions for a wide variety of simple actinide complexes. Equally important is the ability to analyze the information contained therein and produce a chemically meaningful understanding of the electronic structure. Yet the performance of the most common wave function analyses for the calculation of atomic charge and bond order has not been thoroughly investigated for actinide systems. This is particularly relevant because the calculation of charge and bond order even in transition metal complexes is known to be fraught with difficulty. Here we use Mulliken, Lowdin, natural population analysis, atoms-in-molecules (AIM), and fuzzy atom techniques to determine the charges and bond orders of UO(2)(2+), PuO(2)(2+), UO(2), UO(2)Cl(4)(2-), UO(2)(CO)(5)(2+), UO(2)(CO)(4)(2+), UO(2)(CN)(5)(3-), UO(2)(CN)(4)(2-), UO(2)(OH)(5)(3-), and UO(2)(OH)(4)(2-). This series exhibits a clear experimental and computational trend in bond lengths and vibrational frequencies. The results indicate that Mulliken and Lowdin populations and bond orders are unreliable for the actinyls. Natural population analysis performs well after modification of the partitioning of atomic orbitals to include the 6d in the valence space. The AIM topological partitioning is insensitive to the electron donating ability of the equatorial ligands and the relative atomic volume of the formally U(VI) center is counterintuitively larger than that of O(2-) in the UO(2)(2+) core. Lastly, the calibrated fuzzy atom method yields reasonable bond orders for the actinyls at significantly reduced computational cost relative to the AIM analysis.     

Effective potential, Bohm’s potential plus classical potential, analysis of quantum transmission

The influence of spreading, in wavepacket transmission across a potential barrier has been analyzed, by considering several collisions between a wavepacket and a potential barrier, in which the initial distance between the packet and the barrier—the launching distance, is changed. An effective total potential (Bohm’s quantum potential plus classical potential), has been used, to show that, for suitable classical barrier widths and heights, light masses, as well as mean collision energies, one should expect an increase of the quantum transmission factor as the initial wavepacket—barrier distance is decreased. Numerically converged time-dependent wavepacket propagation calculations confirm that trend, leading to an increase as high as 20% per ?, in thin square and Eckart barrier problems. Possibilities of experimentally measuring this effect are also analyzed.     

Integration of sample pretreatment, μPCR,and detection for a total genetic analysis microsystem

Since the emergence of lab-on-a-chip technology, a variety of chemical and biochemical assays were successfully implemented on microdevice platforms. Among the chip-based applications, genetic analysis based on the polymerase chain reaction (PCR) has been extensively developed in order to accomplish the goal of cheap, rapid, high-throughput, and point-of-care DNA testing. We are summarizing here several formats of the miniaturized PCR systems including the integration of units for sample pretreatment and downstream analytical detection. The various sections cover (a) miniaturized PCR systems, (b) integrated sample pretreatment-PCR microsystems, (c) integrated PCR-detection microsystems, and (d) integrated sample pretreatment-PCR-detection microsystems. Respective microdevices were successfully introduced recently in the form of a fully integrated microsystem for genetic analysis with sample-in-answer-out capability. Contains 120 references. Figure

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Mass spectrometry based analysis of nucleotides, nucleosides, and nucleobases—application to feed supplements

In this work, accurate MS-based methods for quantitative profiling of nucleotides, nucleosides, and nucleobases in yeast extracts used as additives in animal feedstuff are presented. Reversed-phase chromatography utilizing a stationary phase compatible with 100% aqueous mobile phases resulted in superior analytical figures of merit than HILIC or ion-pair reversed-phase separation. The novel separation method was combined with both molecular and elemental mass spectrometry. By use of RP-LC-MS-MS, excellent limits of detection <1 μmol L(-1) could be obtained for all the compounds investigated. The elemental speciation analysis approach enabled determination of nucleotides by phosphorus detection. Sensitivity of LC-ICP-MS was 1-2 orders of magnitude lower than that of LC-MS-MS. Quantitative analysis of yeast products using complementary MS detection furnished values in good agreement.     

Fluorescent β-cyclodextrins modified by isomeric aminobenzamides: synthesis, conformational analysis, and fluorescent behaviors

Three isomeric fluorescent β-cyclodextrins bearing 2-, 3-, and 4-(2-aminoethyl)amino-N-butylbenzamide, respectively (1-3) have been synthesized. The conformations of these fluorescent CDs have been investigated by 2D NMR and induced circular dichromism. It is confirmed that the ortho isomer 1 takes a butyl-included conformation, while the other two isomers 2 and 3 display a phenyl-included conformation, respectively. The three fluorescent CDs 1-3 exhibited totally different self- and guest-inclusion fluorescence behavior. In the presence of adamantane carboxylate sodium (ADA) or deoxycholate sodium (DCA), the fluorescence intensity of 1 showed an enhancement over 1-fold, while 2 exhibited dramatic fluorescence quenching. Interestingly, the fluorescent responses of 3 toward two guests respectively were highly distinguishable. The fluorescence intensity of 3 only showed a slight increase upon the addition of ADA, but the addition of DCA led to a large decrease in fluorescence intensity. The investigations have been further carried out by 2D NMR, induced circular dichromism, fluorescence spectroscopy and molecular modeling to explore the relationships between the conformations and the fluorescence characteristics of CDs 1-3 in the absence and presence of guest molecules. On the basis of the above investigations, the origins for the different fluorescence behaviors have been proposed.     

Differential pulse voltammetry in analysis of disinfectants — 2-mercaptobenzothiazole, 4-chloro-3-methylphenol, triclosan, chloramine-T

The aim of this work was to study the possibility of simultaneous voltammetric determination of some disinfectants used as components in cosmetic products. The examined compounds were: triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol), chloramine-T (N-chloro-p-toluenesulfonamide sodium salt), 4-chloro-3-methylphenol and 2-mercaptobenzothiazole. Measurements were performed using glassy carbon electrode immersed in Britton-Robinson buffers which acted as supporting electrolytes. The dependence of oxidation and reduction potentials on pH was examined using cyclic voltammetry. Britton-Robinson buffer of pH 9.9 was chosen for further studies to ensure the best separation of compounds. The resultant oxidation potentials indicate the possibility to simultaneously determine some of the disinfectants.. Oxidation reactions of mixtures containing two compounds (4-chloro-3-methylphenol and chloramine-T, 2-mercaptobenzothiazole and 4-chloro-3-methylphenol, 2-mercaptobenzothiazole and triclosan) were recorded as differential pulse voltammograms.     

Mixed ligand complexes of β-diketonates: synthesis,characterization, and FAB mass spectral analysis

Complexes of the type MLL′ · nB (where M = Ni(II) and Cu(II); LH and L′H = 2,4-pentanedione (acacH), 1-phenyl-1,3-butanedione (bacH), and 1,3-diphenyl-1,3-propanedione (dbmH); n = 0 to 2 and B = water or pyridine) have been synthesized and characterized. IR spectra are consistent with uninegative bidentate ligands. Magnetic moments and electronic spectral studies reveal high-spin octahedral geometry for nickel(II) complexes and distorted octahedral stereochemistry for copper(II) complexes. Frozen chloroform solution ESR spectra of the copper(II) complexes display significant Jahn–Teller distortion and dimeric behavior of the complexes in solution. FAB mass spectra of the copper(II) complexes also exhibit peaks corresponding to dimers. Molecular, pseudo-molecular, dimeric pseudo-molecular, and fragment ion peaks in unit resolution mass spectra have been identified with the help of their isotope distribution pattern expected due to natural abundances of the ⁶³Cu and ⁶⁵Cu isotopes. All the FAB mass spectral peaks from the fragment ions containing copper have been interpreted on the basis of isotope distribution pattern.     

Thermal characterization and kinetic analysis of nesquehonite,hydromagnesite, and brucite,using TG–DTG and DSC techniques

Nesquehonite, hydromagnesite, and brucite are important precursors for the preparation of high-purity magnesia (MgO) using magnesium resources from salt lake as raw materials. In this paper, TG–DTG and DSC were used to investigate the thermal decomposition behaviors of the three precursors. Decomposition kinetic parameters at each stage were evaluated based on the TG data using the iso-conversional method. Decomposition mechanisms were determined using the master-plots method. The decomposition temperature range, heat absorption, and kinetic parameters of the three phases were then compared. The most probable mechanism of each stage from the perspective of crystal structure was found to be consistent with the calculation results from the master-plots method. Results led to the conclusion that nesquehonite is the most appropriate precursor for the preparation of high-purity MgO. Further studies on precursor selection and calcining condition selection for the preparation of MgO using bischofite will benefit from this research.     

Cloning, differential expression, and association analysis with fat traits of porcine IDH3γ gene

Mitochondrial NAD⁺-dependent isocitrate dehydrogenase (IDH3) catalyzes the allosterically regulated rate-limiting step of the tricarboxylic acid cycle activated. In pigs, very little is known about this gene. Here, we cloned 1,346 bp full-length cDNA and 8,778 bp genomic sequence of porcine γ subunit of IDH3 (IDH3γ). IDH3γ contains 12 exons separated by 11 introns. Real-time PCR revealed that IDH3γ mRNA were upregulated in backfat of Large White compared with Meishan and F1 hybrids, and most abundant in small intestine via tissue distribution profile. A microsatellite (“GT” repeats) in second intron was found. The selected pigs were genotyped at this microsatellite. The IDH3γ genotypes showed a significant effect on backfat thickness at thorax–waist (P < 0.05), backfat thickness at sixth to seventh thorax (P < 0.01), and average backfat thickness (P < 0.05). This site seemed to be significantly dominant in action (P < 0.05 for backfat thickness at sixth to seventh thorax, backfat thickness at thorax–waist, and average backfat thickness), and allele B was associated with increase of thickness values of these traits. This locus is possibly considered as a marker for adipose deposition traits.     

Nanofluidics for single-cell analysis

Living single-cell analysis is vital for cell biology, disease pathology, drug discovery and medical treatment. It is of great significance to reveal the law of creature and to explore the mechanism of serious disease. The conventional single cell analysis focuses on a large number of cells or cell lysis, in order to obtain the average information about cells. Therefore, it fails to analyze the real-time and continuous data of differences between the individual cells, thus limiting the developme...     

Accreditation: A forthcoming prerequisite,also for neutron activation analysis laboratories?!

The organization of the INAA laboratory at the Interfaculty Reactor Institute at Delft, The Netherlands, has been brought in accordance with the requirements of Euronorm EN45001 and ISO guide 25 for quality systems. Procedures, techniques and instructions involved in routine INAA have been fully described and documented, and compiled in a quality manual. The implementation of such a quality system and of its accreditation for an INAA laboratory in a university environment are discussed.     

Nano ES GEMMA and PDMA,new tools for the analysis of nanobioparticles—Protein complexes,lipoparticles, and viruses

Differential mobility analysis (DMA) is a technique suited for size analysis as well as preparative collection of airborne nanosized airborne particles. In the recent decade, the analysis of intact viruses, proteins, DNA fragments, polymers, and inorganic nanoparticles was possible when combining this method with a nano-electrospray charge-reduction source for producing aerosols from a sample solution/suspensions. Mass analysis of high molecular weight noncovalent complexes is also possible with this methodology due to the linear correlation of the electrophoretic mobility diameter and the molecular mass. In this work, we present the analysis (size and molecular mass) of high molecular weight multimers (noncovalent functional homocomplex) of Jack bean urease in a mass range from 275 kDa up to 2.5 MDa, with mainly present tri- and hexamers but also higher oligomers of the 91 kDa monomer subunit. In a second experiment, the size analysis of intact very-low-density (approximately 35 nm), low-density ( approximately 22 nm) and high-density lipoparticles (approximately 10 nm), which are heterocomplexes consisting of cholesterol, lipids, and proteins in different ratios, is presented. Results from mobility analysis were in excellent agreement with particle diameters found in literature. The last presented experiment demonstrates size analysis of a rod-like virus and selective sampling of a selected size fraction of electrosprayed, singly-charged tobacco mosaic virus particles. Sampling and subsequent transmission electron microscopic investigations of a specific size fraction (40 nm electrophoretic mobility diameter) revealed the folding of virus particles during the electrospray and charge reduction (electrical stress) as well as solvent evaporation (mechanical stress) process, leading to an observed geometry of 150 (length) x 35 (width) nm (average cylindrical geometry of unsprayed intact virus 300 x 18 nm).     

PXRF, μ-XRF, vacuum μ-XRF, and EPMA analysis of Email Champlevé objects present in Belgian museums

The enamel of 20 Email Champlevé objects dating between the 12th and 19th centuries was investigated by means of microscopic and portable X-ray fluorescence analysis (μ-XRF and PXRF). Seven of these objects were microsampled and the fragments were analyzed with electron probe microanalysis (EPMA) and vacuum μ-XRF to obtain quantitative data about the composition of the glass used to produce these enameled objects. As a result of the evolution of the raw materials employed to produce the base glass, three different compositional groups could be discriminated. The first group consisted of soda-lime-silica glass with a sodium source of mineral origin (with low K content) that was opacified by addition of calcium antimonate crystals. This type of glass was only used in objects made in the 12th century. Email Champlevé objects from the beginning of the 13th century onward were enameled with soda-lime-silica glass with a sodium source of vegetal origin. This type of glass, which has a higher potassium content, was opacified with SnO2 crystals. The glass used for 19th century Email Champlevé artifacts was produced with synthetic and purified components resulting in a different chemical composition compared to the other groups. Although the four analytical techniques employed in this study have their own specific characteristics, they were all found to be suitable for classifying the objects into the different chronological categories.