735 research outputs found
The interaction between nitric acid and unsaturated compounds
The principal products of the interaction of fuming nitric acid with acetylene or ethylene are carbon dioxide and trinitromathane. As well, in the interaction with ethylene, and intermediate to the formation of trinitromethane, is formed the addition compound, nitroethyl alcohol. The course of reaction is fundamentally the same for both compounds, and takes place under varying conditions of temperature, concentration of acid and the presence or absence of metallic salts, though a marked effect - the simplification of the reaction and the reduction of by-products- is obtained by the addition of mercuric nitrate. Measurement of the quantities of carbon dioxide and of trinitromethane formed show that at a maximum only fifty per cent of the carbon of the hydrocarbon molecule is nitrated while fifty per cent is oxidised, and this is accompanied to a varying extent by a second reaction involving direct oxidation to carbon dioxide. The tetranitromethane which can be isolated by further nitration always represents considerably more than that which can be estimated as nitroform in the reaction mixture. Hence there are present in the product substances other than trinitronethane, but possibly intermediate to its formation, which are capable on further nitration of yielding tetranitromethane. Evidence is adduced that the reaction is in all cases one of simple addition to the unsaturated bond of the component parts of the nitric acid molecule, analogous to the addition to unsaturated compounds of the component parts of oxides of nitrogen. Hence, the nitric acid, through the medium of addition, is able to exercise its function both as a nitrating and as an oxidising agent, one carbon of the hydrocarbon molecule becoming nitrated, the other becoming oxidised, finally to carbon dioxide. The influence of mercuric nitrate is largely to increase the rate of absorption and hence of interaction. The mechanism of its effect is complex, but is largely to prevent the alternate reaction of simple oxidation, and hence to increase proportionally the addition reaction producing the nitro alcohol. A similar activating influence of the mercury salt is noticed in the nitration of aromatic compounds, and from this a theory of the mechanism of aromatic nitration is developed.<p
Laser Ultrasonic Thermoelastic/Ablation Generation with Laser Interferometric Detection in Graphite/Polymer Composites
Ultrasonic signals have been generated and detected in graphite/polymer composites by optical methods. A Doppler interferometric technique was used for detection. The output voltage of this type of interferometer is proportional to the surface velocity of a sample area which is illuminated by cw laser light. Ultrasonic signals were generated by thermoelastic and ablation processes which occur as a consequence of laser pulses incident on the opposite surface of the sample. The evolution of the magnitude and shape of the detected signals was measured as a function of the pulse energy of the generating laser. Low-energy laser pulses generated ultrasound without causing obvious surface damage. At higher energies surface damage was observable in post inspection but could also be detected by observing (through protective goggles) bright flashes near the illuminated area. The energy at which these processes first occur is qualitatively referred to as the ablation threshold. Changes in the observed waveform were evident at energies above the ablation threshold. The higher-energy waveforms were found to consist of a superposition of a thermoelastic component and an ablatic component, whose relative magnitudes changed with laser power. A delay in the initiation of the ablatic wave relative to the thermoelastic wave was observed to be of the order of 0.3 μs, consistent with observations in pure polymer. [1] Photoelectric detection measurements of the ablation plume also showed a clear threshold and a time scale for growth of the ablation products with a characteristic time scale on the order of 0.3 μs
Windows and mirrors: reflections of a module team teaching the arts in nurse education.
The five-year experience of a group of nursing lecturers teaching the expressive arts within a Scottish degree programme is outlined and discussed. The place of the arts is contextualised within curriculum developments and module content, sequencing, thematic development, mode of delivery, assessment, student evaluation and pedagogical approaches are all addressed. Relationship to practice is discussed in terms of the art of nursing, reflection, ethics and spirituality. Future developments are discussed in terms of drawing upon the wider resources of the humanities, rather than merely expressivist sources of art. The paper concludes by encouraging the teaching of the arts in nurse education to remain responsive to practice issues and to consideration of students' learning needs
Effects of ulotaront on brain circuits of reward, working memory, and emotion processing in healthy volunteers with high or low schizotypy
Ulotaront, a trace amine-associated receptor 1 (TAAR1) and serotonin 5-HT1A receptor agonist without antagonist activity at dopamine D2 or the serotonin 5-HT2A receptors, has demonstrated efficacy in the treatment of schizophrenia. Here we report the phase 1 translational studies that profiled the effect of ulotaront on brain responses to reward, working memory, and resting state connectivity (RSC) in individuals with low or high schizotypy (LS or HS). Participants were randomized to placebo (n = 32), ulotaront (50 mg; n = 30), or the D2 receptor antagonist amisulpride (400 mg; n = 34) 2 h prior to functional magnetic resonance imaging (fMRI) of blood oxygen level-dependent (BOLD) responses to task performance. Ulotaront increased subjective drowsiness, but reaction times were impaired by less than 10% and did not correlate with BOLD responses. In the Monetary Incentive Delay task (reward processing), ulotaront significantly modulated striatal responses to incentive cues, induced medial orbitofrontal responses, and prevented insula activation seen in HS subjects. In the N-Back working memory task, ulotaront modulated BOLD signals in brain regions associated with cognitive impairment in schizophrenia. Ulotaront did not show antidepressant-like biases in an emotion processing task. HS had significantly reduced connectivity in default, salience, and executive networks compared to LS participants and both drugs reduced this difference. Although performance impairment may have weakened or contributed to the fMRI findings, the profile of ulotaront on BOLD activations elicited by reward, memory, and resting state is compatible with an indirect modulation of dopaminergic function as indicated by preclinical studies. This phase 1 study supported the subsequent clinical proof of concept trial in people with schizophrenia.
Clinical trial registration: Registry# and URL: ClinicalTrials.gov NCT01972711, https://clinicaltrials.gov/ct2/show/NCT0197271
Draft Nuclear Genome, Complete Chloroplast Genome, and Complete Mitochondrial Genome for the Biofuel/ Bioproduct Feedstock Species Scenedesmus obliquus Strain DOE0152z
The green alga Scenedesmus obliquus is an emerging platform species for the industrial production of biofuels. Here, we report the draft assembly and annotation for the nuclear, plastid, and mitochondrial genomes of S. obliquus strain DOE0152z
The occurrence of α chain gene deletions and triplications among pediatric Hb S homozygotes
Approximately 40% of more than 100 young Hb S homozygotes attending the
Pediatric Clinic of the Comprehensive Sickle Cell Center of the Medical College
of Georgia in Augusta have an associated α-thalassemia-2 (α-thal-2) heteroztgosity, i.e. the -α/-α; βs/βs condition, or homozygosity, i.e. the -α/-α; βs/βs condition. These conditions are documented by pulse incubations of peripheral blood reticulocytes and by gene mapping using recombinant DNA probes. All α-thal-2 deletions are associated with a 16 Kb Bgl II α chain DNA
fragment which arises from a deletion of the 3' end of the α2 gene, the 5' end
of the α1 gene and includes the intergenic DNA. Fusion of the residual 3' and
5' ends of the α2 and α1 genes results in a single active a chain gene, i.e.
the -3.7 Kb or Rightward type of deletion. Its 3' sequences belong to the α1
gene. The homozygosity for the condition and Hb S is characterized by higher
Hb levels without an accompanying increase of Hb F percentages; a distinct
microcytosis and hypochromia; splenomegaly and decreased α/non-α values.peer-reviewe
Selective in vitro replication of herpes simplex virus type 1 (HSV-1) ICP34.5 null mutants in primary human CNS tumours--evaluation of a potentially effective clinical therapy.
Primary tumours of the central nervous system (CNS) are an important cause of cancer-related deaths in adults and children. CNS tumours are mostly glial cell in origin and are predominantly astrocytomas. Conventional therapy of high-grade gliomas includes maximal resection followed by radiation treatment. The addition of adjuvant chemotherapy provides little improvement in survival time and hence assessment of novel therapies is imperative. We have evaluated the potential therapeutic use of the herpes simplex virus (HSV) mutant 1716 in the treatment of primary brain tumours. The mutant is deleted in the RL1 gene and fails to produce the virulence factor ICP34.5. 1716 replication was analysed in both established human glioma cell lines and in primary cell cultures derived from human tumour biopsy material. In the majority of cultures, virus replication occurred and consequential cell death resulted. In the minority of tumour cell lines which are non-permissive for mutant replication, premature shut-off of host cell protein synthesis was induced in response to lack of expression of ICP34.5. Hence RL1-negative mutants have the distinct advantage of providing a double hit phenomenon whereby cell death could occur by either pathway. Moreover, 1716, by virtue of its ability to replicate selectively within a tumour cell, has the potential to deliver a 'suicide' gene product to the required site immediately. It is our opinion that HSV which fails to express ICP34.5 could provide an effective tumour therapy
C-Type natriuretic peptide: a potential urinary biomarker for renal remodeling and fibrosis during aging
Rat thimet oligopeptidase: large-scale expression in Escherichia coli and characterization of the recombinant enzyme
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