Ion Peak Research Articles

Sugar Pills? Investigating Humphreys’ Homeopathic Specifics: Utilizing Liquid Chromatography-Tandem Mass Spectrometry for an In-Depth Look at Nineteenth-Century American Homeopathy

Frederick K. Humphreys (1816-1900), founder of Humphreys Medicine Company, appeared at the rise of both greater acceptance and popularity of the homeopathy in the United States, as opposed to more orthodox medicine. Although bolstered by the relatively high cost and low success rate of traditional medicines, homeopathic remedies soon became a source of controversy due to the largely unknown ingredient lists and contradictory claims of effectiveness. Tandem mass spectrometry analysis (MS/MS) was used to pinpoint the ingredients of four “specifics” in Humphreys’ Homeopathic Remedies. Generated spectra showed similar base peak ions for each pill, leading to the hypothesis that each remedy contained the same basic ingredients. Further MS/MS analyses identified these base peak ions as adducts of sucrose (m/z 365, 381), its related ions (m/z 433, 203, 185), and apigenin (m/z 271). When placed into a historical context, the application of chemical analyses to study these early remedies can provide insight into the question of validity that evoked arguments during the late nineteenth century.

Misfire and knock detection based on the ion current inside a passive pre-chamber of gasoline engine

In this study, a novel idea of capturing ion current signals inside the passive pre-chamber is proposed. The signals were analyzed in terms of various operating conditions based on a naturally aspired gasoline engine. Under normal combustion, the chemical and the thermal ionization peak's phase difference is much smaller than the commercial spark plug case. Under the idle condition, misfire cycles by cutting off fuel supply can be detected by integrating ion current signal, with 100% diagnosing sensitivity and its accuracy reaching 99.7%. The candidate knocking cycle is defined as a combustion cycle with an in-cylinder pressure rising rate higher than 0.2 MPa/°CA. Under candidate knocking cycles, a unique knock indication peak from the ion current signal can be noticed. To classify candidate knocking cycles from normal combustion, the phase difference of chemical and the last ionization peak can be regarded as a basis with the sensitivity of 99.7% and the accuracy of 95.7%. For further increasing the diagnostic accuracy, several artificial neural networks were established utilizing various ion current parameters. Through 5-fold cross-validation, with the best-performed combination of the ion current parameters as the input variables, the diagnosis model further improves the diagnostic accuracy from 95.7% to 98.4% with the same sensitivity of 99.7%. Utilizing 3-dimensional simulation, the cause of the knock indication peak in the ion current signal can be explained by the visualized backflow from the main chamber and the traces of critical ions and electrons concentration inside the pre-chamber. The employment of the ion current inside the passive pre-chamber for abnormal combustion detection thus appears very promising.

Structural modification of fentanyls for their retrospective identification by gas chromatographic analysis using chloroformate chemistry

The one-step breakdown and derivatization of a panel of nine fentanyls to yield uniquely tagged products that can be detected by Electron Ionization Gas Chromatography-Mass Spectrometry (EI-GC-MS) is presented. The method involves the treatment of the synthetic opioids with 2,2,2-trichloroethoxycarbonyl chloride (TrocCl) at 60 °C for 3 h in dichloromethane and furnishes two products from one fentanyl molecule that can be used to retrospectively identify the original opioid. Parameters that were studied and fully optimized for the method included temperature, solvent, nature of scavenging base and reaction time. One of the two resulting products from the reaction bears the trichloroethoxycarbonyl (Troc) tag attached to the norfentanyl portion of the original opioid and greatly aids in the opioid detection and identification process. The methodology has been applied to the chemical modification of a panel of nine fentanyls and in all cases the molecular ion peak for the Troc-norfentanyl product bearing the distinctive trichloroethyl isotopic signature can be clearly observed. The method’s LLOD was determined to be 10 ng/mL while its LLOQ was found to be 20 ng/mL. This methodology represents the first application of chloroformates in the chemical modification of this class of synthetic opioids that are notoriously inert to common derivatization strategies available for GC–MS analysis.

Ethyl Acetate Fraction from Leandra dasytricha (A. Gray) Cong. Leaves Promotes Vasodilatation and Reduces Blood Pressure in Normotensive and Hypertensive Rats.

Leandra dasytricha (A. Gray) Cong. is widely distributed in the south of Brazil and is commonly used for cardiovascular and kidney ailments. For this study, we used male Wistar normotensive rats (NTRs) and spontaneously hypertensive rats (SHRs) to verify the effects of the ethyl acetate fraction (EAF) obtained from L. dasytricha leaves on isolated aorta relaxation and in the arterial blood pressure. The EAF was analyzed by LC-DAD-MS, and several components were annotated, including hydrolysable tannins, triterpenes, and O- and C-glycosylated dihydrochalcones, such as the most intense ion peak relative to C-hexosyl phloretin (nothofagin; compound number 13). The EAF caused a concentration and endothelium-dependent relaxation of the aorta in both NTRs and SHRs. This effect was abolished in the endothelium-denuded aorta. L-NAME, a nonselective nitric oxide synthase inhibitor, and ODQ, a soluble guanylate cyclase inhibitor, entirely blocked the EAF-induced relaxation. The presence of a muscarinic receptor antagonist or a cyclooxygenase inhibitor did not alter the EAF's effectiveness in relaxing the aorta. The preincubation with tetraethylammonium, a Ca2+-activated K+ channel blocker, and with 4-aminopyridine, a voltage-dependent K+ channel blocker, significantly interfered with the EAF's relaxation. However, the incubation with glibenclamide, an ATP-sensitive K+ channel blocker, and barium chloride, an inward-rectifier K+ channel blocker, did not interfere with the EAF-induced relaxation. The EAF treatment also caused a dose-dependent decrease in the mean arterial pressure, systolic arterial pressure, and diastolic arterial pressure of both NTRs and SHRs, without significantly interfering with heart rate values. In conclusion, this study demonstrated the EAF-induced vasorelaxant and hypotensive actions, primarily dependent on the endothelium function and mainly with the participation of the nitric oxide and Ca2+-activated and voltage-dependent K+ channels.

Five new multinuclear rare earth complexes: Magnetism and near-infrared luminescence

Five new tri- and tetra-nuclear rare earth complexes utilizing a Schiff base ligand and co-ligand Hdbm were obtained: [Nd3(dbm)6(H2L)3]·3CH3OH (1), [RE4(dbm)6(L)2(CH3OH)3]·2CH3OH (RE = Dy (2), Ho (3), Er (4), Yb (5)), (H3L = N'-(2-carboxide-imidazole)-[(2-hydroxy-3-methoxyphenyl)methylene]hydrazide, Hdbm = 1,3-diphenyl-1,3-propanedione). Complexes 2–5 are centrosymmetric tetranuclear complexes with eight-coordinated REIII ions, while complex 1 is a non-centrosymmetric trinuclear complex with nine-coordinated NdIII ions, which could be caused by lanthanide contraction. The magnetic properties studies show that 2 exhibits representative single-molecule magnets behavior, leading to an energy barrier of 25.3 K as well as pre-exponential factor of 7.21 × 10−7 s. Research on near-infrared luminescence reveals that complexes 1, 3, 4 and 5 emit the characteristic emission peaks of the NdIII ions, HoIII ions, ErIII ions and YbIII ions, respectively. The luminescence lifetime and quantum yield of 5 are 1.39 μs and 0.0695 %, respectively.

Evaluation of intercellular lipid lamellae in the stratum corneum by polarized microscopy.

Intercellular lipids contain a lamellar structure that glows in polarized images. It could be expected that the intercellular lipid content be estimated from the luminance values calculated from polarized images of stratum corneum strips. Therefore, we attempted to develop a method for simple and rapid evaluation of the intercellular lipid content through a procedure. Herein, we demonstrated a relationship between the luminance value and the amount of ceramides, one of the main components of intercellular lipids. The stratum corneum was collected from the forearm using slides with a pure rubber-based adhesive, which did not produce unnecessary luminescence under polarizing conditions. Images were analyzed using luminance indices. The positive secondary ion peak images were obtained using the time of flight-secondary ion mass spectrometry; the polarized and brightfield images were obtained using a polarized microscope. The ceramide and protein amount was measured by high-performance liquid chromatography and bicinchoninic acid protein assay after microscope imaging. Images and quantitative values were used to construct evaluation models based on a convolutional neural network (CNN). There was a correlation between the highlighted areas of the polarized image to overlap with the area where ceramide-derived peak was detected. Evaluation of the CNN-based model of the polarized images predicted the amount of ceramides per unit of stratum corneum. The method proposed in the study enabled a large number of specimens to provide a simple, rapid, and efficient evaluation of the intercellular lipid content.

The Impact of Temperature, Sunlight and Time on the Quality of Drinking Water Stored in Polyethylene Terephthalate Bottle in Yola Metropolis, Nigeria

The present study examined how sunlight radiation, temperature and time in Yola climate can affect the physicochemical properties of drinking water in polyethylene terephthalate (PET) bottle in Yola Metropolis Nigeria. Conductivity, total dissolved solids (TDS), chemical oxygen demand (COD), pH, Cl-, and NO3 - were analyzed using standard methods for 42 days. Solvent extraction and GC-MS analysis were conducted periodically to monitor the appearance and identity of any migrant organic compounds. Sunlight exposure had the highest impact wherein conductivity, TDS, and COD trended upwards while pH decreased over time. However, Cl- and NO3- stayed constant. The GC-MS results showed the highest concentration of organic compounds in the sunlight exposed samples showing the molecular ion peak of benzene. Conversely, the negative control samples, stored in a cool dry place, showed no signs of leachates.

Heterogeneous Composition of Oxygen-Evolving Complexes in Crystal Structures of Dark-Adapted Photosystem II.

Photosystem II (PSII) is a homodimeric protein complex that catalyzes water oxidation at the oxygen-evolving complex (OEC), a heterocubanoid calcium-tetramanganese cluster. Here, we analyze the omit electron density peaks of the OEC's metal ions in five X-ray free-electron laser PSII structures at resolutions between 2.15 and 1.95 Å. The omit peaks can be described by the total number of electrons and approximated by the variance of electron density distribution when the distributions are spherically symmetric. We show that the number of electrons of metal centers is different in the two OECs of PSII dimers, implying that the oxidation states and/or occupancies of individual metal ions are different in the two monomers. In either case, we find that the two OECs of dark-adapted PSII dimers in crystals are not fully synchronized in the S1 state. Differences in redox states of the OEC in PSII only partially account for the observation that the electron densities integrate to a smaller number of electrons than expected. Differences between the determined and expected relative electron numbers are much larger than the estimated errors, indicating heterogeneity in the OEC composition.

Metabolite discovery through global annotation of untargeted metabolomics data.

Liquid chromatography-high resolution mass spectrometry (LC-MS)-based metabolomics aims to identify and quantitate all metabolites, but most LC-MS peaks remain unidentified. Here, we present a global network optimization approach, NetID, to annotate untargeted LC-MS metabolomics data. The approach aims to generate, for all experimentally observed ion peaks, annotations that match the measured masses, retention times, and (when available) MS/MS fragmentation patterns. Peaks are connected based on mass differences reflecting adducting, fragmentation, isotopes, or feasible biochemical transformations. Global optimization generates a single network linking most observed ion peaks, enhances peak assignment accuracy, and produces chemically-informative peak-peak relationships, including for peaks lacking MS/MS spectra. Applying this approach to yeast and mouse data, we identified five previously unrecognized metabolites (thiamine derivatives and N-glucosyl-taurine). Isotope tracer studies indicate active flux through these metabolites. Thus, NetID applies existing metabolomic knowledge and global optimization to substantially improve annotation coverage and accuracy in untargeted metabolomics datasets, facilitating metabolite discovery.

Ag-TiO2@Pd/C nanocomposites for efficient degradation of Reactive Red 120 dye and ofloxacin antibiotic under UV and solar light and its antimicrobial activity

Photodegradation technique is also being employed with naturally available solar energy for treating toxic pollutants to protect environment. In order to achieve the effective degradation of pollutants, the photo-induced charge separation should be in suitable levels. The stability of the catalyst plays an important role in photodegradation. To achieve the above two concepts successfully, the Ag-TiO2 @Pd/C nanocomposites were fabricated by adding different percentages of Pd/C with respect to Ag-TiO2. The formation of the nanocomposites has been exclusively described by different characterization techniques. The prepared nanocomposites have been effectively tested with Reactive Red 120 (RR 120) under direct solar & UV-A light and their performances were explored. In this work, the test parameters such as photocatalyst reusability test and different dye pH have been discussed. Further, the catalyst degraded the antibiotic ofloxacin (OFL), which is being used for the treatment of a number of bacterial infections and the degradation mechanism is proposed below. GC-MS analysis was performed, based on the retention time, molecular ion peaks and intermediates were analyzed and proposed suitable degradation pathways for RR 120 and ofloxacin drug mineralization by Ag-TiO2 @Pd/C nanocomposite. In addition, the anti-microbial activity of synthesized nanocomposites was investigated against twenty pathogens such as Gram-positive Cocci (GBC) (2), Gram-positive Bacilli (GPB) (1), Gram negative Bacilli (GNB) (15) and fungal (2).

Broad antiviral and anti-inflammatory activity of Qingwenjiere mixture against SARS-CoV-2 and other human coronavirus infections

BackgroundQingwenjiere Mixture (QJM) is a traditional Chinese medicine (TCM) that has been shown to have remarkable clinical efficacy against COVID-19. However, little is known about the antiviral and anti-inflammatory activities of QJM against a wider range of human coronavirus (HCoV) strains. PurposeThe study aims to investigate the antiviral and anti-inflammatory activities of QJM, as well as the underlying mechanisms against HCoV infections. MethodsThe chemical compositions from QJM were analyzed by LC-MS. The inhibitory effect of QJM on infections of HCoV-OC43, HCoV-229E, HCoV-NL63, and SARS-CoV-2 was evaluated in HRT-18 cells, Huh7 cells, LLC-MK2 cells, and Vero-E6 cells, respectively, by using cytopathic effect (CPE) inhibition assay or RT-qPCR detection of viral n, s, or RdRp/Hel genes. The expression of pro-inflammatory cytokines induced by HCoV-OC43, HCoV-229E, and SARS-CoV-2, as well as the host ace2 gene was also determined by RT-qPCR assay. Furthermore, the expression of key molecules in the NF-κB/MAPKs signaling pathways was determined by western blot. ResultsIn alcohol-extraction groups of QJM and reference decoction pieces, 53 similar ion peaks were identified, the majority of which were phenylpropanoids, iridoids, and flavonoids. In addition, QJM reduced CPE caused by HCoVs and the expression of viral n genes or N protein. Pretreatment with QJM also exerted inhibitory effect on viral n gene expression. QJM also inhibited the expression of RdRp/Hel and s genes of SARS-CoV-2, as well as the host ace2 gene. Besides, QJM markedly reduced virus-induced mRNA expression of a panel of pro-inflammatory cytokines, such as IL-6, CXCL-8/IL-8, CXCL-10/IP-10, CCL-5/RANTES, TNF-α, IFN-α, CCL-2/MCP-1, CXCL-9/MIG, and IL1-α. We further showed that QJM inhibited the phosphorylation of NF-κB p65, and JNK, ERK 1/2, and p38 MAPKs in HCoV-OC43-infected HRT-18 cells. ConclusionsQJM has broad antiviral and anti-inflammatory activity against both common and newly emerged HCoVs possibly by inhibiting the activation of key components in NF-κB/MAPKs signaling pathway. QJM also has a prevention effect against HCoV infections and inhibits the host receptor required for virus entry. These results indicate that QJM may have the therapeutic potential in the treatment of diseases caused by a broad range of HCoVs.

Technical note: Extraction of proton pencil beam energy spectrum from measured integral depth dose in a cyclotron proton beam system.

Proton pencil beam energy spectrum is an essential parameter for calculations of dose and linear energy transfer. We extract the energy spectrum from measured integral depth dose (IDD). A measured IDD (measIDD) in water is decomposed into many IDDs of mono-energetic pencil beams (monoIDDs) in water. A simultaneous iterative technique is used to do the decomposition that extracts the energy spectrum of protons from the measIDD. The monoIDDs are generated by our analytic random walk model-based proton dose calculation algorithm. The linear independence of the monoIDDs is considered and high spatial resolution monoIDDs are used to improve their linear independence. To validate the extraction, first we use synthesized IDDs (synIDD) with Gaussian energy spectrum and compare the extracted energy spectrum with the Gaussian; second, for the energy spectrum extracted from measIDDs, the accuracy of the extraction is validated by comparing the calculated IDD from the energy spectrum with the measIDD. The measIDDs are derived from commissioning of a cyclotron proton pencil beam system with a Bragg peak ionization chamber. The nominal energy of the pencil beams is from 70 to 245MeV. The monoIDDs are generated for energies from 0.05 to 275MeV in steps of 0.05MeV with a spatial resolution of 1mm. The difference of the extracted and original Gaussian energy spectrum peaked at 75 and 80MeV was <1%. As the energy decreased, the difference increased but was reduced by using 0.1-mm monoIDDs. The difference was not sensitive to the energy interval of monoIDDs when the interval increased from 0.05 to 1MeV. For the energy spectrum extraction from measIDDs, there was a main peak near the nominal energy but the spectrum was not in Gaussian distribution. In three example cases (70, 160, and 245MeV), the relative differences of the measIDDs and calculated IDDs were within 3.4%, 2.9%, and 4.7% of the Bragg peak value, respectively. Fitting the spectrum by Gaussian distribution, we had σ=0.87, 1.51, and 0.86MeV, respectively, for these three examples, and the relative differences of the resultant calculated IDDs from the measIDDs were within 4.7%, 7.4%, and 4.5%, respectively. Our algorithm accurately extracted the energy spectrum from the synIDDs and measIDDs. High-resolution monoIDDs are necessary to extract low-energy spectrum. Energy spectrum extraction from measIDD reveals important information for beam modeling.

Investigation of fermentation-induced changes in the volatile compounds of Trachinotus ovatus (meixiangyu) based on molecular sensory and interpretable machine-learning techniques: Comparison of different fermentation stages

Fermented golden pomfret (Trachinotus ovatus) is appreciated by local consumers owing to its distinct flavor. Electronic nose (E-nose) and gas chromatography-ion mobility spectrometry (GC-IMS) technologies were used to analyze the changes in volatile compounds responsible for evolution of the golden pomfret odor profile during fermentation. Forty-five ion peaks were detected using GC-IMS. Although aldehydes represented the major initial volatile compound group, their levels decreased as fermentation proceeded. Between 3 and 15 days, increased levels of esters contributed to a stable volatile organic compounds profile. After 18 days, high levels of indole and pyrazines were detected. Eleven key volatile compounds were screened based on partial least squares discriminant analysis (PLS-DA). Back propagation artificial neural network (BP-ANN) predicted the fermentation stage enabling the development of better strategies to regulate golden pomfret fermentation. This study provided a theoretical basis for real-time monitoring and quality control of Chinese fermented golden pomfet.

Unravelling the photoprotective effects of freshwater alga Nostoc commune Vaucher ex Bornet et Flahault against ultraviolet radiations.

Several studies have suggested the direct relationship between skin complications, air pollution, and UV irradiation. UVB radiations cause various skin complications such as skin aging, skin inflammation, and skin cancer. The current study is designed to develop an ultraviolet (UV) absorbing MAA-loaded topical gel and to evaluate its UVA and UVB screening potential. MAA was extracted from the Nostoc commune Vaucher ex Bornet et Flahault (N. commune) and characterized by HPLC-PDA (with a retention time 2.6 min), UV-Visible (absorption maximum 334 nm), and mass spectrometry (m/z 346.2) techniques. The methanolic (10%) solution of MAA (50-150 μl) was dissolved in propylene glycol and mixed with hydrated gel (1.5 % of carbopol 934) by using EDTA (0.3%). Eight (F1-F8) formulations were evaluated for their physico-chemical characters. F7 retained its physio-chemical characters for 90 days. Further selected formulation (F7) was evaluated for its gelling strength (GSg), gelling temperature (GT), melting temperature (MT), apparent viscosity (cp), molecular mass (MMS), pH, physical appearance, homogeneity, and spreading diameter (SD). The stability study of the fabricated gel formulation was done as per International Committee on Harmonization guidelines and sunscreen potential was determined by in vitro sunscreen UV method. Findings revealed that GSg (337 ± 1.7 g/cm2), GT (22.8 ± 0.2 °C), cp (71.1 ± 0.2), MMS (424.177 ± 0.7), pH (6.2 ± 0.04), and SD (56 ± 0.2). For in vitro sunscreen potential determination, different concentrations of F7 (50-150 μl) were prepared. Topical application of the F7 displayed UV-A/UV-B photoprotection with SPF 1.13 folds greater then marketed formulation (Lotus herbals UV screen gel). Based on these findings, it was concluded that methanolic extract derived from N. commune contains Porphyra-334 which can be potentially used as photo protective compound in several cosmetic preparations. Development of sunscreen gel from Nostoc commune The current investigation is designed to develop ultraviolet (UV) absorbing MAA (mycosporine amino acid)-loaded topical gel from Nostoc commune to evaluate its UVA and UVB screening potential. LCMS characterization of HPLC-PDA purified MAA from N. commune methanolic extract demonstrated a prominent ion peak of a protonated molecule ([M + H]+) at m/z 346.2 [M+H]+ value confirmed the presence of Porphyra-334. Porphyra-334 is a broad-spectrum sun-protective compound evidenced for its potential in blocking UVA and UVB (Bhatia et al. 2010). Prepared sunscreen formulations remain stable for prolonged period and provide broad-spectrum protection against harmful UV range.

SYNTHESIS OF 1,2,3-TRIAZOLO-QUINOLIZIDINES BASED ON THE QUINOLIZIDINE ALKALOID LUPININE

The modification of the quinolysin alkaloid lupinine was carried out with the intro-duction of 1,2,3-triazolyl substituents for the hydroxymethylene group in the C-1 position of the quinolysin backbone. The reaction of lupinine with methanesulfochloride in the presence of triethylamine smoothly led to lupinine methanesulfonate, whose further reaction with sodium azide in DMFA led to lupinilazide. 1,3-Dipolar [4+2]-cycloaddition of the resulting azide to alkynes produced more stable 1,2,3-triazole compounds. The interaction of lupinilazide with 2-ethinylpyridine and with alcohols containing a terminal acetylene group (propargyl alcohol, 2-methylbut-3-in -2-ol or hex-5-in -1-ol) proceeded smoothly in the DMFA medium. The reactions were carried out in the presence of an aqueous solution of CuSO4 and sodium ascorbate in DMFA and allowed the corresponding 4-substituted (1S,9aR)-1H-1,2,3-triazol-1-yl to be synthesized with good yields)methyl)octahydro-1H-quinolysins. The results of studying the structural features of synthesized compounds by 1H - and 13C - NMR spectroscopy, as well as data from the two-dimensional COSY (1H-1H) and HMQC (1H-13C) spectra are presented. The values of chemical shifts, multiplicity and integral intensity of 1H and 13C signals in one-dimensional NMR spectra are determined. In the spectra of all synthesized new quinolizi-dinotriazoles, there is a peak of the fragmentary C10H17N ion (150-151 cu), corresponding to the cleavage of the molecule by the C-10 atom of the quinolizidine backbone.

Dehydroepiandrosterone sulfate, dehydroepiandrosterone, 5α-dihydroprogesterone and pregnenolone in women with migraine: Analysis of serum levels and correlation with age, migraine years and frequency

Migraine is a very painful, disabling and extremely common disorder among the world's adult population, especially women, and it is associated with a variety of comorbidities. Neuroactive steroids exhibit pleiotropic actions on the nervous system. Alterations in their peripheral and central levels could be involved in the pathogenesis, still not fully understood, of migraine and its comorbidities. The purpose of our exploratory study was to determine and compare the serum levels of dehydroepiandrosterone sulfate (DHEAS), dehydroepiandrosterone (DHEA), 5α-dihydroprogesterone (DHP) and pregnenolone (PREGNE) between women suffering from migraine without aura (MO group, n = 30) and age-matched non-headache women as controls (C group, n = 30). Correlations with age, migraine years and frequency were also analyzed. The patients were enrolled at a headache center; controls were patients’ contacts. Calibrators and serum samples were spiked with the internal standards (ISs) solution and treated to deplete proteins and phospholipids. The obtained extracts were evaporated to dryness, derivatized and analyzed by LC-MS/MS in multiple reaction monitoring mode. Analytes’ levels were determined by interpolation on the regression curves, generated from the analyte quantifier ion peak area to the corresponding IS. MO group presented significantly lower levels of DHEAS, DHEA and DHP compared to C group (P < 0.05, Student’t-test) and the neurosteroid levels negatively correlated with years of migraine and migraine days/3 months (P < 0.05, linear regression analysis). These results parallel to previous studies showing reduced serum levels of allopregnanolone and pregnenolone sulfate in women with migraine. The low serum levels found for both excitatory and inhibitory neurosteroids suggested that women with migraine might suffer from inadequate neuroprotection, anti-inflammation activity and pain modulation. These deficits might underlie the migraine chronification process and represent the link between migraine and its various comorbidities.

Sequential double ionization of molecules by strong laser fields simulated with time-dependent configuration interaction.

A new time-dependent configuration interaction method has been developed for simulating strong field sequential double ionization of molecular systems. Ionization of the neutral is simulated by time-dependent configuration interaction with single excitations (TD-CIS) and an absorbing boundary. At each time step, the ionized part of the wavefunction from the TD-CIS calculation is transferred to a second time-dependent configuration interaction simulation for ionization of the cation to the dication. The second simulation uses a CISD-IP wavefunction that consists of singly ionized configurations and singly excited, singly ionized configurations (TD-CISD-IP). The transfer between the TD-CIS and TD-CISD-IP simulations is accomplished by partitioning the first ionization rate into contributions from individual orbitals or by singular value decomposition of the absorbed wavefunction. Sequential double ionization simulations have been carried out for HBr in five cycle 800nm linearly polarized pulses and HI (with spin-orbit coupling) in four cycle 800nm circularly polarized pulses, with intensities chosen so that the population of the neutral was depleted by the mid-pulse. The singular value decomposition of the cation produced by the first ionization is dominated by a single component for the two orientations considered. The population of the cation rises and then falls as it is ionized to the dication. Depending on the pulse shape and field strength, the ionization of the cation to the dication can continue for several half cycles. For HI with circularly polarized light, the rates for both the first and second ionization peak when the electric field is aligned with the pπ orbital.

Full Workflows for the Analysis of Gas Chromatography-Ion Mobility Spectrometry in Foodomics: Application to the Analysis of Iberian Ham Aroma.

Gas chromatography—ion mobility spectrometry (GC-IMS) allows the fast, reliable, and inexpensive chemical composition analysis of volatile mixtures. This sensing technology has been successfully employed in food science to determine food origin, freshness and preventing alimentary fraud. However, GC-IMS data is highly dimensional, complex, and suffers from strong non-linearities, baseline problems, misalignments, peak overlaps, long peak tails, etc., all of which must be corrected to properly extract the relevant features from samples. In this work, a pipeline for signal pre-processing, followed by four different approaches for feature extraction in GC-IMS data, is presented. More precisely, these approaches consist of extracting data features from: (1) the total area of the reactant ion peak chromatogram (RIC); (2) the full RIC response; (3) the unfolded sample matrix; and (4) the ion peak volumes. The resulting pipelines for data processing were applied to a dataset consisting of two different quality class Iberian ham samples, based on their feeding regime. The ability to infer chemical information from samples was tested by comparing the classification results obtained from partial least-squares discriminant analysis (PLS-DA) and the samples’ variable importance for projection (VIP) scores. The choice of a feature extraction strategy is a trade-off between the amount of chemical information that is preserved, and the computational effort required to generate the data models.

Synthesis of Co (ii) and Zn (ii) complexes of modified and unmodified cashew nut (Anacardium occidentals L.) shell liquid extract

Cashew nut shell liquid (CNSL) extract obtained using soxhlet extraction method with acetone as solvent has been used in the synthesis of Co (II) and Zn (II) metal complexes. The CNSL gave a molecular peak ion of 298g/mol-1 on a GC-MS, an indication that cardanol was more prominent than anacardic acid in the obtained extract. Physicochemical parameters such as saponification value (50.30 mgKOH/g), moisture content (5.10), iodine value (241.00 mgKOH/g), ash content (1.30) and pH (6.31) were equally obtained. The metal complexes of Co (II) and Zn (II) prepared with unmodified (UMCNSL) and aniline modified CNSL (AMCNSL) were characterized using UV-visible, FTIR, melting point and electrical conductivity. Some characteristic FTIR bands were observed for AMCNSL, UMCNCL, AMCNSL-ZnCl2.H2O (1612cm-1) and AMCNSL-CoCl2.6H2O (1612cm-1). The presence of C=N were confirmed in the metal complex of AMCNSL-ZnCl.H2O and AMCNSL-CoCl.6H2O but were not present in the UMCNSL-ZnCl.H2O and UMCNSL-CoCl.6H2O.

ISOLATION AND STRUCTURAL ELUCIDATION OF SECONDARY METABOLITE FROM STEM BARK EXTRACT OF Pterocarpus Mildbreadii

Pterocarpus mildbreadii leaves and stem bark have been exploited in Nigeria, in the area of alternative medicine, due to their numerous biological properties. The upsurge in the search for new chemical agents to replace conventional drugs, prompted this study. The study was carried out for the first time, in the area of isolation and structural elucidation of bioactive compounds, from the ethanolic extracts of the stem bark of Pterocarpus mildbreadii. The ethanol extract of the stem bark was separated using column chromatographic technique. The fractions obtained were screened for antioxidant activity in a DPPH assay. The active fraction was further purified and the structure elucidated by subjecting it to a number of identification instruments, such as FTIR, MS and 1D &amp;2D NMR spectroscopy. The FTIR analysis of isolated bioactive compound gave the following λ max: 3400-2500 cm-1 a broad band characteristic of a carboxylic acid functional group and 1740 cm-1 carbonyl stretch. The mass spectrum game a molecular ion peak at m/z 282 consistent with the molecular formula C18H34O2. The proton NMR showed a doublet of doublet of doublet at 4.9, 5.3 and 5.8 ppm attributed to vinyl protons, two proton multiplets at 1.6,1.3, and 1.2 ppm; and a three proton triplet at 0.9 ppm. The HMBC and 13C NMR showed the presence of a carboxylic carbon at 176 ppm and vinylic carbons at 135 and 143 ppm respectively; the methyl carbon was observed at 14.12 ppm. On the basis of spectral analysis, results obtained suggested compound was cis-vaccenic acid and was confirmed by comparison with literature data. Isolated compound has antioxidant activity, with a maximum percentage scavenging activity of 89.66. The present study lends credence to the use of the plant in traditional medicine and posits pterocarpus mildbreadii as a rich source of secondary metabolites which can find application in the pharmaceutical industries.