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The widespread abuse of "legal high" psychoactive plants continues to be of global concern because of their negative impacts on public health and safety. In forensic science, a major challenge in controlling these substances is the paucity of methods to rapidly identify them. We report the development of the

The most severe forms of kidney diseases are often associated with irreversible damage to the glomerular podocytes, the highly specialized epithelial cells that encase glomerular capillaries and regulate the removal of toxins and waste from the blood. Several studies revealed significant changes to podocyte cytoskeletal structure during disease onset, suggesting possible roles of cellular mechanosensing in podocyte responses to injury. Still, this topic remains underexplored partly due to the lack of appropriate

The United Nations Office on Drugs and Crime designated twenty psychoactive botanical species as “plants of concern” because of their increased recreational abuse. Four of these are used to prepare ayahuasca brews. The complexity of the plant matrices, as well as the beverage itself, make the identification and quantification of the Schedule I component, N,N-dimethyltryptamine (DMT), a time-consuming and resource-intensive endeavor when performed using conventional approaches previously reported. Reported here is the development of a rapid validated method for the quantification of DMT in ayahuasca by direct analysis in real time-high-resolution mass spectrometry (DART-HRMS). This ambient ionization approach also enables identification of ayahuasca through detection of the secondary metabolites associated with its plant constituents. Analysis of six ayahuasca brews created using different combinations of DMT/harmala alkaloid-containing plants resulted in beverages with DMT levels of 45.7–230.5 mg/L. The detected amounts were consistent with previously reported values determined by conventional approaches.

The utilization of entomological specimens such as larvae (maggots) for the estimation of time since oviposition (i.e., egg laying) for post mortem interval determination, or for estimation of time since tissue infestation (in investigations of elder or child care neglect and animal abuse cases), requires accurate determination of insect species identity. Because the larvae of multiple species are visually highly similar and difficult to distinguish, it is customary for species determination of maggots to be made by rearing them to maturity so that the gross morphological features of the adult can be used to accurately identify the species. This is a time-consuming and resource-intensive process which also requires that the sample be viable. The situation is further complicated when the maggot mass being sampled is comprised of multiple species. Therefore, a method for accurate species identification, particularly for mixtures, is needed. It is demonstrated here that direct analysis in real time-high resolution mass spectrometric (DART-HRMS) analysis of ethanol suspensions containing combinations of maggots representing Calliphora vicina, Chrysomya rufifacies, Lucilia coeruleiviridis, L. sericata, Phormia regina, and Phoridae exhibit highly reproducible chemical signatures. An aggregated hierarchical conformal predictor applied to a hierarchical classification tree that was trained against the DART-HRMS data enabled, for the first time, multispecies identification of maggots in mixtures of two, three, four, five, and six species. The conformal predictor provided label specific regions with confidence limits between 80 and 99% for species identification. The study demonstrates a novel, rapid, facile, and powerful approach for identification of maggot species in field-derived samples.

It is challenging to achieve highly efficient thermoelectric materials due to the conflicts between thermopower (Seebeck coefficient) and electrical conductivity. These parameters are the core factors defining the thermoelectric property of any material. Here, we report the use of isovalent substitution as a tool to decouple the interdependency of the Seebeck coefficient and the electrical properties of cerium-doped bismuth selenide thermoelectric material. With this strategy, we can achieve a simultaneous increase in both the electrical conductivity and the Seebeck coefficient of the material by tuning the concentration of cerium doping, due to formation of neutral impurities and consequently the improvement of carrier mobility. Our theoretical calculation reveals a downward shift of the valence band with cerium concentration, which influences the thermoelectric enhancement of the synthesized materials. Finally, an order of magnitude enhancement of the figure of merit is obtained due to isovalent substitution, thus providing a new avenue for enhancing the thermoelectric performance of materials.

The mechanisms, energetics, and kinetics of the gas-phase reactions of terrestrial plant-derived dimethyl thiosulfinate (DMTS) with the atmospheric oxidants OH and Cl radicals were investigated using high-level ab initio calculations. The results show that the addition of OH and Cl radicals to the sulfinyl [-S(═O)] of DMTS, followed by S(═O)-S single bond cleavage to form methanesulfinic acid + CH3S• and methanesulfinyl chloride + CH3S•, respectively, are the more dominant reactions. The barrier heights for the reactions with OH and Cl radicals were found to be -5.6 and -12.7 kcal/mol relative to the energies of the starting reactants, respectively, when computed at the CCSD(T)/aug-cc-pVTZ//M06-2X/6-311++G(3df,3pd) level of theory. The rate constants for all possible pathways of DMTS + •OH/•Cl reactions were investigated using the MESMER kinetics code over the temperature range between 200 and 300 K. The calculated global rate constants for the DMTS + •OH and DMTS + •Cl reactions at 300 K were found to be 1.42 × 10-11 and 3.72 × 10-11 cm3 molecule-1 s-1, respectively. In addition, the thermochemistry of all possible paths and branching ratios was determined. The atmospheric chemistry implications of the DMTS + •OH/•Cl reactions are discussed.

Carboranes have been extensively investigated as potential drugs for the treatment of malignant human brain tumors by boron neutron capture therapy (BNCT). This noninvasive treatment modality utilizes compounds containing the nonradioactive isotope 10B which has a high propensity to capture slow neutrons. In response, it emits high energy α-particles that kill the cell. We have successfully synthesized a boron delivery agent by installing a boron-rich m-carborane within the amino acid cysteine. Rapid uptake of this compound into U87 glioblastoma cells within 5 min of exposure was observed, and fluorescence microscopy studies showed that it was retained intracellularly after 48 h. In the absence of thermal neutrons, a cytostatic effect in U87 cells was observed at exposures ranging from 1 μM to 1 mM relative to the control, while no change was observed at 1-0.01 μM. Microarray studies unveiled a wide range of unique changes in the gene expression profile of the U87 cells, particularly for the genes associated with cell cycle, which were observed to be greatly suppressed after treatment with the compound. These results were validated by qPCR studies. Although the compound was designed for BNCT, its distinctive impacts on gene regulation reveal that it and other carborane-containing cluster molecules may exert unique heretofore unknown effects on the transcriptome, even in the absence of applied radiation.

Several plants of agricultural and medicinal importance utilize defense chemistry that involves deployment of highly labile, reactive, and lachrymatory organosulfur molecules. However, this chemistry is difficult to investigate because the compounds are often short-lived and prone to degradation under the conditions required for analysis by common analytical techniques. This issue has complicated efforts to study the defense chemistry of plants that exploit the use of sulfur in their defense arsenals. This work illustrates how direct analysis in real time-high resolution mass spectrometry (DART-HRMS) can be used to track organosulfur defense compound chemistry under mild conditions. Petiveria alliacea was used as a model plant that exploits the enzyme alliinase to generate induced organosulfur compounds in response to herbivory. Tracking of the organosulfur compounds it produces and quantifying them by DART-HRMS using isotopically labeled analogues revealed a feedback inhibition loop through which the activities of the alliinase are stymied shortly after their activation. The results show that the downstream thiosulfinate products petivericin (100 μM) and pyruvate (8.4 mM) inhibit alliinase activity by 60% and 29%, respectively, after 1 h, and a mixture of the two inhibited alliinase activity by 65%. By 2 h, alliinase activity in the presence of these alliinase-derived products had ceased completely. Because thiosulfinate, pyruvate, and lachrymatory sulfine compounds are produced via the same alliinase-derived sulfenic acid intermediate, the inhibition of alliinase activity by increasing concentrations of downstream products shows how production of these defense compounds is modulated in real time in response to a tissue breach. These findings provide a framework within which heretofore unexplained phenomena observed in the defense chemistry of P. alliacea, onion, garlic, and other plants can be explained, as well as an approach by which to track labile compounds and enzymatic activity by DART-HRMS.

Species determination of the various life stages of flies (Order: Diptera) is challenging, particularly for the immature forms, because analogous life stages of different species are difficult to differentiate based on morphological features alone. It is demonstrated here that direct analysis in real time-high-resolution mass spectrometry (DART-HRMS) combined with supervised Kohonen Self-Organizing Maps (SOM) enables accomplishment of species-level identification of larva, pupa, and adult life stages of carrion flies. DART-HRMS data for each life stage were acquired from analysis of ethanol suspensions representing Calliphoridae, Phoridae, and Sarcophagidae families, without additional sample preparation. After preprocessing, the data were subjected to a combination of minimum Redundancy Maximal Relevance (mRMR) and Sparse Discriminant Analysis (SDA) methods to select the most significant variables for creating accurate SOM models. The resulting data were divided into training and validation sets and then analyzed by the SOM method to define the proper discrimination models. The 5-fold venetian blind cross-validation misclassification error was below 7% for all life stages, and the validation samples were correctly identified in all cases. The multiclass SOM model also revealed which chemical components were the most significant markers for each species, with several of these being amino acids. The results show that processing of DART-HRMS data using artificial neural networks (ANNs) based on the Kohonen SOM approach enables rapid discrimination and identification of fly species even for the immature life stages. The ANNs can be continuously expanded to include a larger number of species and can be used to screen DART-HRMS data from unknowns to rapidly determine species identity.

The colonization of decomposing remains by necrophagous insects such as blow flies is of forensic importance because the progression through the various stages of insect development can be correlated to time of death. The ability to infer this information hinges on accurate determination of the fly species that are associated with the entomological evidence collected. This evidence can include eggs, larvae, pupae, and puparial casings. Determination of the egg's identity is particularly challenging because the eggs of multiple species are morphologically very similar. We report here that the species identity of fly eggs can be determined from their chemical fingerprint signatures acquired by direct analysis in real time high-resolution mass spectrometry (DART-HRMS). Thus, freshly laid eggs were collected and readily distinguished from multiple necrophagous fly species in the Manhattan area of New York City. These species included representatives from the blow fly family (Calliphoridae), specifically Calliphora vicina, Lucilia sericata, L. coeruleiviridis, and Phormia regina species as well as the Phoridae and Sarcophagidae families. Multivariate statistical analysis of their observed DART-HRMS spectra revealed intraspecies similarities and interspecies differences that were the basis of species differentiation. The chemical basis of discrimination was differences in amino acid profiles. This represents the first chemically based fly egg identification approach with applications to forensic entomology. The rapidity of the method makes feasible the generation of a fly egg chemical profile database against which the DART-HRMS spectra of unknown eggs can be screened to rapidly assess species identity without needing to rear the eggs to adulthood.

Methods for the accomplishment of small-molecule imaging by mass spectrometry are challenged by the need for sample pretreatment steps, such as cryo-sectioning, dehydration, chemical fixation, or application of a matrix or solvent, that must be performed to obtain interpretable spatial distribution data. Furthermore, these steps along with requirements of the mass analyzer such as high vacuum, can severely limit the range of sample types that can be analyzed by this powerful method. Here, we report the development of a laser ablation-direct analysis in real time imaging mass spectrometry approach which couples a 213 nm Nd:YAG solid state UV laser to a direct analysis in a real time ion source and high-resolution time-of-flight mass spectrometer. This platform enables facile determination of the spatial distribution of small-molecules spanning a range of polarities in a diversity of sample types and requires no matrix, vacuum, solvent, or complicated sample pretreatment steps. It furnishes high-resolution data, can be performed under ambient conditions on samples in their native form, and results in little to no fragmentation of analytes. We demonstrate its application through determination of the spatial distribution of molecules involved in the biosynthetic cascade leading to formation of the clinically relevant alkaloids atropine and scopolamine in Datura leichhardtii seed tissue.

Water and energy are key resources in the process industry. The increasing pressure on freshwater and energy resources coupled with stringent environmental regulations on effluent discharge limits have called for innovative designs for sustainable use of water and energy. This can be achieved through process integration techniques that are environmentally benign and economically feasible. This work proposes a robust water network superstructure optimization approach for the synthesis of a multiregenerator network for simultaneous water and energy minimization. Two types of membrane regenerators are considered for this work, namely, electrodialysis and reverse osmosis. In each of the membrane regenerators, a detailed design model is developed and incorporated into the water network model. The detailed model presented in this work is compared to the more common “blackbox” model, which uses linear expressions to represent costs of regeneration units. The results show that the “blackbox” model gives inaccurat...

The spermicide nonoxynol-9 is actually a complex mixture of dozens of closely related amphiphilic compounds, and the chemical properties of this assortment significantly hamper its characterization by GC-MS. The inability to perform routine GC-MS testing on nonoxynol-9 has limited its evidentiary value in forensic casework, which relies heavily on this technique for analysis. A disturbing trend in sexual assault is the use of condoms by assailants, to avoid leaving behind DNA evidence that can connect a perpetrator to a victim. This observation necessitates the development of alternative methods for the analysis of trace evidence that can show causal links between a victim and a suspect. Detection of lubricants associated with sexual assault is one such way to establish this connection. The development of GC-MS methods that permit facile detection of both nonoxynol-9 alone and nonoxynol-9 extracted from other complex matrices that have potential as trace evidence in sexual assault is reported. A detection limit of 2.14 μg of nonoxynol-9 is demonstrated, and a detailed mass spectral profile that elaborates on what is known of its structure is provided.

Nectaroscordum (Lindl.) Gren. & Godr. (Alliaceae) is a small subgenus of the genus Allium consisting of only two species, Allium siculum (Ucria) Lindl. and Allium tripedale (Trautv.) Grossh. Both are rare ornamental bulbous plants used in gardening. The former is native to Asia Minor, southern France, and Sicily (hence the trivial name Sicilian honey garlic), where it grows in damp shady woods. It is still sometimes referred to by the synonymous names Allium nectaroscordum, Nectaroscordum siculum Ucria, A. dioscorides auct., or A. meliophilum Juz. The second member of the subgenus, A. tripedale (syn. N. tripedale Trautv. or N. persicum (Bornm.) Bornm.), is indigenous to Armenia, Iran, and Iraq. Both members of the Nectaroscordum subgenus, A. siculum and A. tripedale, are very closely related to other plants of the genus Allium L. Due to their close morphological similarities, the relationship between these two groups has long been embroiled in taxonomic controversy. At present, classification of Nectaroscordum as a subgenus in the Allium genus is generally accepted. The chromosome basic number of x ) 9, special and unique characteristics of most flower parts, and other morphological peculiarities of Nectaroscordum species were the main arguments in support of separating this oligotypic group at a generic level. 1-3 A. siculum attracted our attention because of its odor, which is notably different from that of common alliaceous plants. This paper describes our investigation of the amino acid odor precursors present in this plant and their primary breakdown products.