Kinetic study of an on-chip isocyanate derivatization reaction by on-line nano-esi ms

A high-throughput method is presented for the study of reaction kinetics by nano- electrospray ionization mass spectrometry (nano-ESI MS). The reaction of propyl isocyanate (2), benzyl isocyanate (3), and toluene-2,4-diisocyanate (4) with 4-nitro-7- piperazino-2,1,3-benzoxadiazole (NBDPZ) (1) to yield the corresponding urea derivatives (5) was carried out in a continuous flow glass microchip. Real-time monitoring of the reactions was done by nano-ESI MS. Rate constants of 1.6 ␣ 104 M-1 min-1, 5.2 ␣ 104 M-1 min-1, and 2.5 ␣ 104 M-1 min-1 were determined for isocyanate 2, 3 and 4, respectively

Fluorescence and Mass Spectrometric Detection Schemes for Simultaneous Enzymatic Conversions: Method Development and Comparison

Fluorescence and mass spectrometric detection schemes are developed and compared for the simultaneous activity determination of two enzymes in solution. As model system, the following reactions are used: The alkaline phosphatase catalyzed reaction with 5-fluorosalicyl phosphate yields the fluorescent 5-fluorosalicylic acid, whereas microperoxidase 11 reacts with 4-(N-methylhydrazino)-7-nitro-2,1,3-benzooxadiazole and H2O2 to the strongly fluorescent 4-(N-methylamino)-7-nitro-2,1,3-benzooxadiazole. As the emission spectra of the fluorescent products as well as the molecular masses of substrates and products do not interfere with each other, is it possible to determine both reactions in parallel with both detection schemes. The measurements resulted in the same limits of detection, limits of quantification and linear ranges of the single/simultaneous enzyme determination for fluorescence and MS detection. While the relative standard deviations were significantly lower in case of fluorescence detection (1.4–3.2%) than in mass spectrometry (5.7–10.1%), the latter proved to be the more versatile approach for multianalyte determination

Parent and Family Outcomes of PEERS: A Social Skills Intervention for Adolescents with Autism Spectrum Disorder

Raising a child with an Autism Spectrum Disorder (ASD) is associated with increased family chaos and parent distress. Successful long-term treatment outcomes are dependent on healthy systemic functioning, but the family impact of treatment is rarely evaluated. The Program for the Education and Enrichment of Relational Skills (PEERS) is a social skills intervention designed for adolescents with high-functioning ASD. This study assessed the impact of PEERS on family chaos, parenting stress, and parenting self-efficacy via a randomized, controlled trial. Results suggested beneficial effects for the experimental group in the domain of family chaos compared to the waitlist control, while parents in the PEERS experimental group also demonstrated increased parenting self-efficacy. These findings highlight adjunctive family system benefits of PEERS intervention and suggest the need for overall better understanding of parent and family outcomes of ASD interventions

Electrochemistry-on-chip for on-line conversions in drug metabolism studies

We have designed an integrated 3-electrode electrochemical cell on-chip with high analyte conversion rates for use in drug metabolism studies. The electrochemical cell contains platinum working and counter electrodes and an iridium oxide pseudo-reference electrode. The pseudo-reference electrode has a pH sensitivity of −52 mV/s, and thus will provide a constant potential in solutions with known and constant pH. The average drift of the iridium oxide electrode is below 5 mV for a typical 15 min conversion experiment. We have been able to mimic the oxidative drug metabolism reactions catalysed by enzymes of the cytochrome P-450 family, normally occurring in the human body. With the chip, the different reaction products of both rat liver cell microsome and human liver cell microsome incubations have been observe

Measuring the Plasticity of Social Approach: A Randomized Controlled Trial of the Effects of the PEERS Intervention on EEG Asymmetry in Adolescents with Autism Spectrum Disorders

This study examined whether the Program for the Education and Enrichment of Relational Skills (PEERS: Social skills for teenagers with developmental and autism spectrum disorders: The PEERS treatment manual, Routledge, New York, 2010a) affected neural function, via EEG asymmetry, in a randomized controlled trial of adolescents with Autism spectrum disorders (ASD) and a group of typically developing adolescents. Adolescents with ASD in PEERS shifted from right-hemisphere gamma-band EEG asymmetry before PEERS to left-hemisphere EEG asymmetry after PEERS, versus a waitlist ASD group. Left-hemisphere EEG asymmetry was associated with more social contacts and knowledge, and fewer symptoms of autism. Adolescents with ASD in PEERS no longer differed from typically developing adolescents in left-dominant EEG asymmetry at post-test. These findings are discussed via the Modifier Model of Autism (Mundy et al. in Res Pract Persons Severe Disabl 32(2):124, 2007), with emphasis on remediating isolation/withdrawal in ASD

LA-ICP-MS/MS improves limits of detection in elemental bioimaging of gadolinium deposition originating from MRI contrast agents in skin and brain tissues

© 2018 Elsevier GmbH A novel analytical method to detect the retention of gadolinium from contrast agents for magnetic resonance imaging (MRI) in tissue samples of patients is presented. It is based on laser ablation - inductively coupled plasma - triple quadrupole - mass spectrometry (LA-ICP-MS/MS). Both Gd and P were monitored with a mass shift of +16, corresponding to mono-oxygenated species, as well as Zn, Ca, and Fe on-mass. This method resulted in a significantly reduced background and improved limits of detection not only for phosphorus, but also for gadolinium. These improvements were essential to perform elemental bioimaging with improved resolution of 5 μm x 5 μm, allowing the detection of small Gd deposits in fibrotic skin and brain tumour tissue with diameters of approximately 50 μm. Detailed analyses of these regions revealed that most Gd was accompanied with P and Ca, indicating co-precipitation

Brief Report: Assessment of Intervention Effects on In Vivo Peer Interactions in Adolescents with Autism Spectrum Disorder (ASD)

This study aimed to evaluate the effectiveness of a randomized controlled trial of a social skills intervention, the Program for the Education and Enrichment of Relational Skills (PEERS: Laugeson et al. in J Autism Dev Disord 39(4): 596–606, 2009), by coding digitally recorded social interactions between adolescent participants with ASD and a typically developing adolescent confederate. Adolescent participants engaged in a 10-min peer interaction at pre- and post-treatment. Interactions were coded using the Contextual Assessment of Social Skills (Ratto et al. in J Autism Dev Disord 41(9): 1277–1286, 2010). Participants who completed PEERS demonstrated significantly improved vocal expressiveness, as well as a trend toward improved overall quality of rapport, whereas participants in the waitlist group exhibited worse performance on these domains. The degree of this change was related to knowledge gained in PEERS

Laminar flow of two miscible fluids in a simple network

When a fluid comprised of multiple phases or constituents flows through a network, non-linear phenomena such as multiple stable equilibrium states and spontaneous oscillations can occur. Such behavior has been observed or predicted in a number of networks including the flow of blood through the microcirculation, the flow of picoliter droplets through microfluidic devices, the flow of magma through lava tubes, and two-phase flow in refrigeration systems. While the existence of non-linear phenomena in a network with many inter-connections containing fluids with complex rheology may seem unsurprising, this paper demonstrates that even simple networks containing Newtonian fluids in laminar flow can demonstrate multiple equilibria. The paper describes a theoretical and experimental investigation of the laminar flow of two miscible Newtonian fluids of different density and viscosity through a simple network. The fluids stratify due to gravity and remain as nearly distinct phases with some mixing occurring only by diffusion. This fluid system has the advantage that it is easily controlled and modeled, yet contains the key ingredients for network non-linearities. Experiments and 3D simulations are first used to explore how phases distribute at a single T-junction. Once the phase separation at a single junction is known, a network model is developed which predicts multiple equilibria in the simplest of networks. The existence of multiple stable equilibria is confirmed experimentally and a criteria for their existence is developed. The network results are generic and could be applied to or found in different physical systems

Sweet spheres: Succession and CAZyme expression of marine bacterial communities colonizing a mix of alginate and pectin particles

Polysaccharide particles are important substrates and microhabitats for marine bacteria. However, substrate-specific bacterial dynamics in mixtures of particle types with different polysaccharide composition, as likely occurring in natural habitats, are undescribed. Here, we studied the composition, functional diversity and gene expression of marine bacterial communities colonising a mix of alginate and pectin particles. Amplicon, metagenome and metatranscriptome sequencing revealed that communities on alginate and pectin particles significantly differed from their free-living counterparts. Unexpectedly, microbial dynamics on alginate and pectin particles were similar, with predominance of amplicon sequence variants (ASVs) from Tenacibaculum, Colwellia, Psychrobium and Psychromonas. Corresponding metagenome-assembled genomes (MAGs) expressed diverse alginate lyases, several co-localised in polysaccharide utilisation loci. Only a single, low-abundant MAG showed elevated transcript abundances of pectin-degrading enzymes. One specific Glaciecola ASV dominated the free-living fraction, possibly persisting on particle-derived oligomers through different glycoside hydrolases. Elevated ammonium uptake and metabolism signified nitrogen as important factor for degrading carbon-rich particles, whereas elevated methylcitrate and glyoxylate cycles suggested nutrient limitation in surrounding waters. The bacterial preference for alginate, whereas pectin primarily served as colonization scaffold, illuminates substrate-driven dynamics within mixed polysaccharide pools. These insights expand our understanding of bacterial niche specialisation and the biological carbon pump in macroalgae-rich habitats