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1.
J Forensic Sci ; 68(4): 1148-1161, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37282977

ABSTRACT

Aminoindanes are a class of novel psychoactive substances (NPSs) that have become more prevalent over the past decade. GC-MS is often utilized for identifying seized drugs and is well regarded for its ability to separate mixtures. However, certain aminoindanes have similar mass spectral data and require specific gas chromatographic stationary phases for separation. Derivatization is an alternative method that can be applied to GC-MS to enhance chromatographic results, providing more selective analysis in seized-drug identification. This study investigates derivatization techniques to provide options for forensic science laboratories in accurately identifying aminoindanes. Three derivatization reagents, N-methyl-bis(trifluoroacetamide) (MBTFA), heptafluorobutyric anhydride (HFBA), and ethyl chloroformate (ECF) were evaluated for the analysis of eight aminoindanes by GC-MS using two common gas chromatographic stationary phases, Rxi®-5Sil MS and Rxi®-1Sil MS. All three derivatization methods successfully isolated eight aminoindanes, including the isomers 4,5-methylenedioxy-2-aminoindane (4,5-MDAI), and 5,6-methylenedioxy-2-aminoindane (5,6-MDAI) that could not be differentiated prior to derivatization. Reduced peak tailing and increased abundance were observed after derivatization for all the compounds, and mass spectra of the derivatives contained individualizing fragment ions that allowed for further characterization of the aminoindanes. This excluded 4,5-MDAI and 5,6-MDAI as they shared the same characteristic ions and were only distinguishable by their retention times. All three derivatization techniques used in this study allow for successful characterization of the aminoindanes and give forensic science laboratories flexibility in their analysis approach when they encounter these compounds.

2.
Rapid Commun Mass Spectrom ; 35(24): e9207, 2021.
Article in English | MEDLINE | ID: mdl-34599535

ABSTRACT

RATIONALE: Aminoindanes are one class of many new psychoactive substances that have emerged over the last decade. Analogues of 2-aminoindane (2-AI) are being encountered in crime laboratories and analytical data for most aminoindanes are limited. Interpretation and optimization of gas chromatography-mass spectrometry data will enhance reliability in characterizing aminoindanes. METHODS: This study focuses on the electron ionization mass spectrometric fragmentation of eight aminoindane analogues and the gas chromatographic separation of these eight aminoindane analogues using four different column stationary phases, Rxi®-1Sil MS, Rxi®-5Sil MS, Rxi®-35Sil MS, and Rxi®-624Sil MS. Split injection (25:1) was utilized and each column had the same configuration (30 m × 25 mm × 0.25 µm), with the exception of the Rxi®-624Sil MS column (30 m × 25 mm ×1.4 µm). RESULTS: Mass spectra showed strong molecular ions for all aminoindanes, except for rasagiline that produced a uniquely abundant [M - 1] ion. Other characteristic fragmentation that was present for all the aminoindanes included indane and indene ions (m/z 115-117), the tropylium ion (m/z 91), and subsequent loss of diene to produce smaller ions that followed: phenyl (m/z 77), cyclopentadienyl (m/z 65), cyclobutadienyl (m/z 51), and cyclopropenyl (m/z 39). CONCLUSIONS: Separation of eight aminoindanes was optimized, and linear retention indices were determined for the compounds on four capillary columns. Based on the retention data, all eight aminoindanes were resolved on an Rxi®-624Sil MS column. Each aminoindane exhibited unique fragmentation ions in the mass spectra to distinguish between similar analogues. The results of this study will strengthen the analytical profiles of 2-AI and seven analogues, assisting forensic scientists in their analysis and identification of these substances.

3.
Curr Drug Deliv ; 18(9): 1338-1351, 2021.
Article in English | MEDLINE | ID: mdl-33583375

ABSTRACT

BACKGROUND: Rifampicin is one of the first-line drugs used for tuberculosis therapy. The therapy lasts for a long time. Thus, there is a need to develop a sustained release formulation of rifampicin for intravenous application. AIM: This study is focused on preparing rifampicin-loaded bovine serum albumin nanoparticles (RIF BSA NPs) suitable for intravenous application using systematic quality by design (QbD) approach. OBJECTIVES: The main objective of this study is optimizing particle size and entrapment efficiency of rifampicin-loaded bovine serum albumin nanoparticles (RIF BSA NPs) and making them suitable for intravenous application using QbD approach. METHODS: Quality target product profile was defined along with critical quality attributes (CQAs) for the formulation. 32 factorial design was used for achieving the predetermined values of CQAs, i.e., mean particle size <200 nm and percent entrapment efficiency>50%. Incubation time of drug with colloidal albumin solution and ratio of rifampicin to albumin, were selected as independent variables. Checkpoint analysis was performed to confirm the suitability of the regression model for optimization. RESULTS: The optimized RIF BSA NPs were characterized by FTIR, DSC, 1H NMR techniques. The NPs observed by transmission electron microscopy were spherical in shape. The rifampicin release could be sustained for 72 hours from BSA NPs matrix. RIF BSA NPs dispersion was stable at 5 ± 3°C for 72 hours. Non-toxicity of nanoparticles to RAW 264.7 cell line was proved by MTT assay. CONCLUSION: Development of RIF BSA NPs with desired quality attributes was possible by implementing the QbD approach. The optimized formulation suitable for intravenous application can potentially improve the therapeutic benefits of rifampicin.


Subject(s)
Nanoparticles , Serum Albumin, Bovine , Drug Carriers , Particle Size , Rifampin
4.
J Food Biochem ; 44(7): e13260, 2020 07.
Article in English | MEDLINE | ID: mdl-32378233

ABSTRACT

Dragon fruit has caught the attention of many researchers in the last few years because of its vast therapeutic potential. The fruit is enriched with several phytochemical constituents having tremendous pharmacological properties. It is traditionally used as a coloring agent. Some newly explored therapeutic applications include its use as an antioxidant, antimicrobial, antidiabetic, anticancer, and nutraceutical. The phytoconstituents can be extracted from flesh, peel, and seeds of the fruit. The fruit is known to be a rich source of betacyanin, vitamin C, and lycopene. The current review is focused on phytochemical constituents of dragon fruit along with its pharmacological activities. It also sheds light on the safety aspects of the fruit. The review will pave a path for researchers to study this marvel fruit further for societal benefit. Advanced research on dragon fruit will unleash many more therapeutic benefits and can give mechanistic insight about its activities. PRACTICAL APPLICATIONS: Phytoconstituents play a vital role in the treatment of various diseases and for the improvement of human health, in general. Dragon fruit is known to be having antioxidant, anti-microbial, anti-diabetic, anti-cancer applications. The fruit can also be used as a nutraceutical (functional food). To grab all the benefits from this fruit, its phytoconstituents and pharmaco-therapeutic aspect have to be thoroughly studied. This review can be very useful for researchers across different fields like botany, agriculture, pharmacy, etc., to bridge the gap for collaborative work on dragon fruit, which will help in finding solutions for many modern diseases.


Subject(s)
Cactaceae , Fruit , Antioxidants/therapeutic use , Betacyanins , Humans , Plant Extracts/therapeutic use
5.
Forensic Sci Int ; 307: 110135, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31923853

ABSTRACT

Identifying drug analogs can be a vexing problem for forensic scientists particularly in today's evolving drug market. This study proposes a method that utilizes microcrystalline tests, Raman microspectroscopy, and chemometrics to help solve this problem. In the present case, the method described was used to clearly differentiate and identify phencyclidine (PCP) and four of its analogs, namely tenocyclidine (TCP), rolicyclidine (PCPy), 3-methoxy phencyclidine (3-MeO PCP), and 4-methoxy phencyclidine (4-MeO PCP). Microcrystals were grown from each drug with gold chloride and examined using polarized light microscopy. Morphological and optical properties such as shape, habit, time of growth, color, retardation colors, type/angle of extinction, and sign of elongation were observed and documented to characterize each microcrystal. Analysis with a Raman microscope was able to provide structural information on the microcrystals. Objective analysis of the microcrystal spectra was done by employing chemometrics. A training set of Raman shifts was compiled and transformed with principal component analysis (PCA) followed by linear discriminant analysis (LDA). The training set was validated by leave-one-out cross validation (LOOCV) and subsequently ran against a separately-compiled test set. Mahalanobis distances between test samples and the clusters of training samples in LDA space were calculated to empirically demonstrate the applicability of this drug analysis technique. From the results of this study, a drug analysis protocol was developed for analysts to use for the identification of PCP, TCP, PCPy, 3-MeO PCP, and 4-MeO PCP and to serve as a model for drug analogs in general.

6.
Percept Mot Skills ; 120(3): 841-59, 2015 Jun.
Article in English | MEDLINE | ID: mdl-26106803

ABSTRACT

Slowed reaction time (RT) represents both a risk factor for and a consequence of sport concussion. The purpose of this study was to determine the reliability and criterion validity of a novel clinical test of simple and complex RT, called RT(clin), in contact sport athletes. Both tasks were adapted from the well-known ruler drop test of RT and involve manually grasping a falling vertical shaft upon its release, with the complex task employing a go/no-go paradigm based on a light cue. In 46 healthy contact sport athletes (24 men; M = 16.3 yr., SD = 5.0; 22 women: M age = 15.0 yr., SD = 4.0) whose sports included soccer, ice hockey, American football, martial arts, wrestling, and lacrosse, the latency and accuracy of simple and complex RT(clin) had acceptable test-retest and inter-rater reliabilities and correlated with a computerized criterion standard, the Axon Computerized Cognitive Assessment Tool. Medium to large effect sizes were found. The novel RT(clin) tests have acceptable reliability and criterion validity for clinical use and hold promise as concussion assessment tools.


Subject(s)
Athletic Injuries/diagnosis , Brain Concussion/diagnosis , Exercise Test/standards , Reaction Time/physiology , Adolescent , Adult , Child , Female , Humans , Male , Reproducibility of Results , Young Adult
7.
Forensic Sci Int ; 244: 196-206, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25259942

ABSTRACT

Synthetic cathinones are a class of designer drugs that have captured the attention of researchers and law enforcement agencies around the world. Driven by heightening legal restrictions, this class of drugs now encompasses a large number of psychoactive substances. The detection and characterization of these drugs is complicated by the ever-growing size of the cathinone family. This has fueled the development of unambiguous identification of these drugs in various matrices. There are, however, very few methods reported for improving presumptive screening of seized materials. In this paper, we evaluate the performance of the standard (63)Ni ionization ion mobility spectrometry (IMS) technique for the screening and identification of representative cathinones and associated psychoactive compounds. We discuss the effectiveness of the instrument as a screening tool for cathinones by the analyses of 13 typical cathinone products marketed as "bath salts". Our results show that the ion mobility spectrometer is an acceptable rapid and efficient screening tool for cathinones, positively detecting at least one cathinone in 77% of the samples tested. In addition, we describe an electrospray ionization (ESI) high performance IMS (HPIMS) method for these compounds. The method offers advantages in direct sample ionization and higher resolution. Mass spectrometry (MS) coupled to the HPIMS technique gives the added benefit of identification of ion peaks in products with mixtures of closely related cathinones.


Subject(s)
Alkaloids/analysis , Designer Drugs/chemistry , Psychotropic Drugs/chemistry , Spectrometry, Mass, Electrospray Ionization/methods , Nickel , Radioisotopes
8.
Am J Sports Med ; 42(3): 566-76, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24488820

ABSTRACT

BACKGROUND: Greater neck strength and activating the neck muscles to brace for impact are both thought to reduce an athlete's risk of concussion during a collision by attenuating the head's kinematic response after impact. However, the literature reporting the neck's role in controlling postimpact head kinematics is mixed. Furthermore, these relationships have not been examined in the coronal or transverse planes or in pediatric athletes. HYPOTHESES: In each anatomic plane, peak linear velocity (ΔV) and peak angular velocity (Δω) of the head are inversely related to maximal isometric cervical muscle strength in the opposing direction (H1). Under impulsive loading, ΔV and Δω will be decreased during anticipatory cervical muscle activation compared with the baseline state (H2). STUDY DESIGN: Descriptive laboratory study. METHODS: Maximum isometric neck strength was measured in each anatomic plane in 46 male and female contact sport athletes aged 8 to 30 years. A loading apparatus applied impulsive test forces to athletes' heads in flexion, extension, lateral flexion, and axial rotation during baseline and anticipatory cervical muscle activation conditions. Multivariate linear mixed models were used to determine the effects of neck strength and cervical muscle activation on head ΔV and Δω. RESULTS: Greater isometric neck strength and anticipatory activation were independently associated with decreased head ΔV and Δω after impulsive loading across all planes of motion (all P < .001). Inverse relationships between neck strength and head ΔV and Δω presented moderately strong effect sizes (r = 0.417 to r = 0.657), varying by direction of motion and cervical muscle activation. CONCLUSION: In male and female athletes across the age spectrum, greater neck strength and anticipatory cervical muscle activation ("bracing for impact") can reduce the magnitude of the head's kinematic response. Future studies should determine whether neck strength contributes to the observed sex and age group differences in concussion incidence. CLINICAL RELEVANCE: Neck strength and impact anticipation are 2 potentially modifiable risk factors for concussion. Interventions aimed at increasing athletes' neck strength and reducing unanticipated impacts may decrease the risk of concussion associated with sport participation.


Subject(s)
Brain Concussion/prevention & control , Craniocerebral Trauma/physiopathology , Head Movements/physiology , Muscle Strength/physiology , Neck Muscles/physiology , Adolescent , Adult , Age Factors , Biomechanical Phenomena/physiology , Brain Concussion/physiopathology , Child , Female , Humans , Isometric Contraction/physiology , Male , Multivariate Analysis , Risk Factors , Rotation , Transducers
9.
J Basic Microbiol ; 53(4): 327-35, 2013 Apr.
Article in English | MEDLINE | ID: mdl-22736484

ABSTRACT

This study was conducted to assess the effect of microbial inoculation in Jatropha cake composting with different vegetable waste. The microbial inoculums composed of fungal strains (Aspergillus awamori, Aspergillus nidulans, Trichoderma viride, Phanerochaete chrysosporium) and bacterial inoculums (Pseudomonas striata as phosphorus solublizer and Azotobacter chroococcum as nitrogen fixer) were added to the compost mixture after the thermophilic phase was over for bioaugmenting of Jatropha cake under aerobic and partial anaerobic conditions. Addition of both fungal and bacterial inoculum with mixed substrate (Jatropha cake + vegetable waste) during composting (aerobic and partial anaerobic) showed, better results as compared to compost with only fungal inoculants. Increased enzymatic activity initially, during composting (like dehydrogenase, alkaline phosphatase activity and FDA) proved role of inoculated microbes in rapid decomposition. Analysis of compost (with both bacterial and fungal inoculum) showed presence of high humus (12.7%), humic acid (0.5%), fulvic acid (5.68%), soluble protein content and low C/N ratio. Decreased in concentration of extractable metals (Cu, Fe and Mn) were recorded at maturity in all the substrate composts. The C/N ratio was significantly correlated to parameters like humic acid, humus, fulvic acid, protein and also microbial activity parameters. We conclude that the composting of de-oiled Jatropha cake with different vegetables waste could be feasible and sustainable approach in recycling of agricultural and industrial residues in huge quantities.


Subject(s)
Bacteria/growth & development , Fungi/growth & development , Jatropha/microbiology , Soil Microbiology , Soil/chemistry , Aerobiosis , Agriculture/methods , Anaerobiosis , Bacteria/metabolism , Carbon/analysis , Fungi/metabolism , Metals/analysis , Nitrogen/analysis
10.
World J Microbiol Biotechnol ; 28(3): 1223-35, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22805842

ABSTRACT

The performance of three selected bacterial strains-PR3, PR7 and PR10 (Providencia sp., Brevundimonas sp., Ochrobacterium sp.) and three cyanobacterial strains CR1, CR2 and CR3 (Anabaena sp., Calothrix sp., Anabaena sp.), and their combinations was evaluated in a pot experiment with rice variety Pusa-1460, comprising 51 treatments along with recommended fertilizer controls. Highest yield enhancement of 19.02% was recorded in T12 (CR2), over control, while significant enhancement in nitrogen fixing potential was recorded in treatments involving combination of bacterial-cyanobacterial strains-T37 (PR3 + CR1 + CR3) and T21 (PR7 + CR1). Organic carbon was significantly increased in all microbe-inoculated treatments, which could be correlated with microbial biomass carbon values and activities of all the enzymes tested in our study. Also, panicle weight and plant biomass were highly correlated with soil microbial carbon. Comparative evaluation revealed the superior performance of strains CR2, CR1 (both Anabaena sp.) and PR10 (Ochrobacterium sp.) in increasing the growth and grain yield of rice and improving soil health, besides N (nitrogen) savings of 40-80 kg ha(-1). The study for the first time illustrated the positive effects of co-inoculation of bacterial and cyanobacterial strains for integrated nutrient management of rice crop.


Subject(s)
Bacteria/metabolism , Carbon/metabolism , Nitrogen/metabolism , Oryza/growth & development , Rhizosphere , Soil Microbiology , Bacteria/growth & development , Biomass , Oryza/metabolism , Oryza/microbiology
11.
Forensic Sci Int ; 208(1-3): 29-36, 2011 May 20.
Article in English | MEDLINE | ID: mdl-21109373

ABSTRACT

Smokeless powder additives are usually detected from an extraction of post-blast residues or unburned powder particles followed by chromatographic analyses. This work presents the first comprehensive study of the detection of volatile and semi-volatile additives of smokeless powders using solid phase microextraction (SPME) as a sampling and pre-concentration technique. The goal of this study is to generate a list of compounds that can be used as target compounds for the vapor phase detection of smokeless powders. Sixty-five smokeless powders were studied using laboratory-based gas chromatography techniques and a field deployable ion mobility spectrometer (IMS). The detection of diphenylamine, ethyl and methyl centralite, 2,4-dinitrotoluene, diethyl and dibutyl phthalate by IMS is suggested as a method to indicate the presence of smokeless powders. A previously reported SPME-IMS analytical approach facilitates rapid sub-nanogram detection of the vapor phase components of smokeless powders. The analyte mass present in the vapor phase was sufficient for a SPME fiber to extract and concentrate most analytes at amounts above the detection limits of both the GC and the IMS methods. Analysis of 65 different smokeless powder samples revealed that diphenylamine was present in the headspace of 96% of the powders studied. Ethyl centralite was detected in 47% of the powders and 8% of the powders contained methyl centralite. Nitroglycerin was the dominant peak present in the headspace of the double-based powders. Another important headspace component, 2,4-dinitrotoluene, was detected in 44% of the powders comprising both double and single-based powders. Static headspace SPME of small amounts (∼100 mg) of smokeless powder samples for ∼5 min at room temperature resulted in the successful detection of the headspace components, demonstrating the applicability of the technique for field detection of smokeless powders using IMS as a detector.

12.
Pol J Microbiol ; 59(2): 99-105, 2010.
Article in English | MEDLINE | ID: mdl-20734754

ABSTRACT

Cyanobacteria represent less a investigated group of prokaryote, in terms of their plant growth promoting potential, especially in relation to the production of phytohormones. The present investigation was aimed towards analyzing growth kinetics, indole acetic acid (IAA) production and acetylene reduction activity (ARA) as an index of nitrogen fixation in two selected cyanobacterial strains belonging to the genus Anabaena, as influenced by tryptophan supplementation and light:dark conditions. Interesting observations were recorded in terms of enhancement of IAA production accompanied by protein and chlorophyll accumulation in the two cyanobacterial strains grown in media without tryptophan and incubated under light:dark or continuous light conditions. Colorimetric and chromatographic analyses supported the observations that tryptophan is not essential as a precursor for IAA biosynthesis in these cyanobacteria. Further study is in progress to identify genes involved in the tryptophan independent pathway for IAA biosynthesis.


Subject(s)
Cyanobacteria/metabolism , Cyanobacteria/radiation effects , Indoleacetic Acids/metabolism , Tryptophan/metabolism , Chlorophyll/metabolism , Light
13.
Anal Bioanal Chem ; 398(2): 1049-60, 2010 Sep.
Article in English | MEDLINE | ID: mdl-20652552

ABSTRACT

Solid-phase microextraction (SPME) is a widely used sampling technique that has been proved to enable efficient extraction of a broad range of analytes. Generally, SPME achieves non-exhaustive extraction, and therefore the analyte mass transfer distribution in the sampled multiphase system should be considered while developing a calibration method. Here, a new method, aimed at quantifying the extracted analytes without the need to consider their mass distribution, is proposed. This method relies on the generation of mass response curves by loading a known analyte mass onto the absorbent phase of a SPME fiber, and then conducting analysis by the preferred technique. Precise and accurate deposition of analyte over the restricted dimension of a fiber is demonstrated for the first time by utilizing a drop-on-demand microdrop printer. This system enables direct, non-contact deposition of micron-sized drops containing negligible solvent volumes (<1 nL), on the center of the extraction phase of the fiber which enables immediate analysis. Printed fiber response curves were determined herein, with three model compounds of different volatility-2,4-dinitrotoluene (2,4-DNT), diphenylamine (DPA), and 1,3 diethyl-1,3-diphenylurea (ethyl centralite, EC), using two analytical techniques, gas chromatography-mass spectrometry (GC-MS) and ion mobility spectrometry (IMS). Quantification of the absolute amounts extracted by headspace SPME yielded comparable results between the two methods of analysis with only less than 10% variation for 2,4-DNT and EC and less than 30% for DPA. In comparison, quantification by the traditional liquid injection/spike response curves determined by each technique led to mass estimates that were significantly greater by hundreds of percent.

14.
Forensic Sci Int ; 188(1-3): 112-8, 2009 Jul 01.
Article in English | MEDLINE | ID: mdl-19410393

ABSTRACT

The detection of hidden explosives through their odors is of great importance to law enforcement agencies and trained canines have traditionally been used for this purpose. This paper reports the extraction of odor signature compounds characteristic of smokeless powders, followed by their detection by ion mobility spectrometers (IMS). Such a method enables the detection of odor compounds, complementing canine detection and allows for mass calibration of IMS instruments. The smokeless powder additives reported include diphenylamine (DPA), ethyl centralite, 2-ethyl 1-hexanol and 2,4-dinitrotoluene. The pre-concentration of these volatile odor chemicals from different commercial smokeless powders onto a solid phase microextraction (SPME) device followed by IMS analysis is demonstrated in this paper. Five samples of smokeless powder samples representing double-based and single-based powders from three popular commercial brands were chosen for this study. Diphenylamine was found to be a common additive among all the powders tested. The mass of the analytes in the headspace available for detection was determined from response curves of the corresponding standards. The response curves were generated by printing precise amounts of standards onto substrates and analyzing them. The absolute detection limits were also determined from these response curves and the values ranged from 0.12 to 1.2 ng for the standards. Typical extraction times ranged between 5 and 40 min and the mass of diphenylamine and ethyl centralite extracted at the lowest extraction times was found to be greater than the LOD of the compounds.

15.
J Basic Microbiol ; 48(3): 186-94, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18506903

ABSTRACT

A set of seventy axenised and unicyanobacterial isolates belonging to the genus Anabaena were evaluated for biocidal activity against a set of phytopathogenic fungi. Among them, 35 Anabaena strains showed zone of inhibition against one or more fungi. The extracellular filtrates from 4 and 8 weeks old cultures of these Anabaena strains were further evaluated in terms of hydrolytic enzymes, proteins and IAA employing standard methods. Significant differences were also observed among the strains in terms of their FPase, chitosanase and xylanase activity, while low and relatively similar values of CMCase, cellobiase and protease activity were recorded in the strains analyzed. IAA production was also observed in all the strains. Comparative evaluation of activity of hydrolytic enzymes and antifungal activity revealed that such enzymes may contribute to the fungicidal activity of the cyanobacterial strains, besides other bioactive compounds, including IAA, which are established promising traits for biocontrol agents. This study is a first time report on the production of hydrolytic enzymes by these oxygenic photosynthetic prokaryotes, which can be potential candidates for the development of biocontrol agent(s) against selected phytopathogenic fungi.


Subject(s)
Anabaena/enzymology , Bacterial Proteins/metabolism , Fungicides, Industrial/pharmacology , Indoleacetic Acids/metabolism , Alternaria/drug effects , Anabaena/isolation & purification , Aspergillus/drug effects , Cellulase/metabolism , Endo-1,4-beta Xylanases/metabolism , Fusarium/drug effects , Glycoside Hydrolases/metabolism , Hydrolysis , Peptide Hydrolases/metabolism , Plant Diseases , Soil Microbiology , beta-Glucosidase/metabolism
16.
J Sep Sci ; 31(2): 402-12, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18196520

ABSTRACT

Current ion mobility spectrometry (IMS) devices are used to detect drugs and explosives in the form of particles and, in cases where the vapor pressure of the drugs or explosives is sufficiently high, the gas can be sampled and detected directly. The aim of this study is to demonstrate the use of solid phase microextraction (SPME) as a preconcentration technique coupled to an IMS for the detection of odor signature compounds of drugs and explosives. The reduced mobilities (K(o)) and IMS operating conditions for the odor signature compounds of cocaine, marijuana, and 3,4-methylenedioxy-N-methylamphetamine (MDMA) are reported for the first time. LODs, linear dynamic ranges (LDRs), and the precision of the analysis of these odor signature compounds, and the explosive taggant 2,3-dimethyl-2,3-dinitrobutane (DMNB) were obtained by SPME-IMS and normal IMS conditions. The systematic optimization of the IMS operating parameters for the detection of these odor compounds is also reported incorporating the use of genetic algorithms (GAs) for finding the optimal settings for the detection of these compounds of interest. These results support the case for targeting volatile components as a presumptive detection for the presence of the parent compounds of drugs and explosives. Furthermore, the IMS-specific GA developed can be used as an optimization tool for the detection of other compounds of interest in future work.


Subject(s)
Explosive Agents/analysis , Pharmaceutical Preparations/analysis , Spectrum Analysis/methods , Sensitivity and Specificity , Volatilization
17.
Diabetes Technol Ther ; 7(2): 323-36, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15857235

ABSTRACT

BACKGROUND: Metabolic abnormalities associated with type 2 diabetes mellitus (DM2) are caused in part by inadequate insulin action and resulting changes in gene expression in the skeletal muscle. Two recent, independent studies of human skeletal muscle biopsies from ethnically diverse DM2 patients have identified coordinated reductions in the expression of the oxidative phosphorylation (OXPHOS) genes. Whether these reductions are a consequence or a cause of impaired insulin sensitivity remains an open question. METHODS: To address this question and to define the underlying molecular causes consistent with the expression changes reported in the muscle studies, we created a large-scale computable model to analyze the molecular actions and effects of insulin on muscle gene expression. The model enables computer-aided reasoning using over 210,000 molecular relationships assembled from the DM2 literature. RESULTS: We integrated the data from these muscle biopsy studies into the model and used computer-aided causal reasoning to discover mechanisms that can link alterations in OXPHOS genes to decreases in glucose transport, insulin signaling, and risk factors associated to post-transplant diabetes mellitus. CONCLUSIONS: The emerging hypotheses describe biologic effects in DM2 and offer important cues for molecular targeted therapy.


Subject(s)
Diabetes Mellitus, Type 2/genetics , Diabetes Mellitus, Type 2/metabolism , Algorithms , Blood Glucose/metabolism , Computer Simulation , Gene Expression Regulation/physiology , Genome , Humans , Insulin Resistance/physiology , Mexican Americans , Models, Statistical , Muscle, Skeletal/metabolism , Oxidative Phosphorylation , RNA/biosynthesis , RNA/genetics , Scandinavian and Nordic Countries , Thiazoles/therapeutic use
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