40 research outputs found

    Experimental Measurement of Local Burning Velocity Within a Rotating Flow

    Get PDF
    The final publication is available at link.springer.com.The work presented in this paper details the implementation of a new technique for the measurement of local burning velocity using asynchronous particle image velocimetry. This technique uses the local flow velocity ahead of the flame front to measure the movement of the flame by the surrounding fluid. This information is then used to quantify the local burning velocity by taking into account the translation of the flame via convection. In this paper the developed technique is used to study the interaction between a flame front and a single toroidal vortex for the case of premixed stoichiometric methane and air combustion. This data is then used to assess the impact of vortex structure on flame propagation rates. The burning velocity data demonstrates that there is a significant enhancement to the rate of flame propagation where the flame directly interacts with the rotating vortex. The increases found were significantly higher than expected but are supported by burning velocities [22-24] found in turbulent flames of the same mixture composition. Away from this interaction with the main vortex core, the flame exhibits propagation rates around the value recorded in literature for unperturbed laminar combustion [18-21]

    The Unusual Late-Onset Graves’ Disease following Hashimoto’s Related Hypothyroidism: A Case Report and Literature Review

    No full text
    Background. The shift of Graves’ disease (GD) to Hashimoto’s disease- (HD-) related hypothyroidism is well established. However, the opposite is rare. This is likely to the loss of critical thyroid mass available for stimulation by thyroid hormone receptor stimulating antibody, making this shift unusual. Herein, we report a young lady with a late shift from HD into GD and present a scoping literature review. Case presentation. We report a twenty-five-year-old lady with a sixteen-year-history of Hashimoto’s-related hypothyroidism stable on levothyroxine. While following in the clinic, she started developing thyrotoxic symptoms in the form of anxiety, weight loss, and palpitation. Physical examination was remarkable for mild exophthalmos. The thyroid function test confirmed hyperthyroidism. Levothyroxine-induced hyperthyroidism was initially suspected; however, the symptoms did not improve despite reducing and stopping levothyroxine. Subsequent workup confirmed the diagnosis of GD. Discussion and Conclusion. This case highlights a unique association that has significant diagnostic and management implications. This shift should be considered when hyperthyroidism persists despite reducing or stopping levothyroxine. The diagnosis is made utilizing antibody titers and radioiodine update scan. While the management depends on the disease’s stage and the treating physician preference, antithyroid agents can be used initially. Following up these patients is essential as the shift can be transient

    The PHOENICE Project: A Synergic Use of Innovative Technologies for the Next Generation of Green Hybrid Powertrains

    No full text
    The PHOENICE project aims at developing a C SUV-class plug-in hybrid (P0/P4) vehicle demonstrator whose fuel consumption and pollutant emissions are jointly minimized for real-world driving conditions. Technologies developed in PHOENICE are targeting a TRL 7 paying a specific attention to cost, industrialization, and to the use opportunity for various vehicle classes so as to maximize the economic and environmental impacts. This project is aiming to support the European automobile industry in the medium term and speed up the transition towards a more environmentally friendly mobility in terms of air quality and GHG emissions. The achievement of these ambitious goals will require the optimization of a highly efficient gasoline engine, relying on a dual dilution combustion approach with excess air and EGR, synergizing an innovative in-cylinder charge motion with high-pressure injection, novel ignition technologies, and an electrified turbocharger particularly relevant for hybrid architectures. The potential of alternative fuels produced by P2X processes will also be considered. To achieve the targeted near-zero-emissions in real driving conditions, the demonstrator vehicle will be equipped with a complete and dedicated aftertreatment system, including an electrically heated catalyst, a SCR and a GPF for abating NOx, particle number down to 10 nm, and non-regulated gaseous emissions. Finally, the vehicle overall efficiency will be increased with an exhaust waste heat recovery system for generating an additional electric power contribution for cabin heating or cooling, or for reducing the switch-on time of the internal combustion engine in cold conditions, thereby limiting the engine-out pollutant emissions such as particles

    Leucettines, a family of pharmacological inhibitors of DYRKs and CLKs kinases derived from the marine sponge Leucettamine B

    No full text
    International audienceWe here report on leucettines, a family of kinase inhibitors derived from the marine sponge leucettamine B. Stepwise synthesis of analogues, followed by activity testing on 8 purified kinases led to highly potent inhibitors of CLKs & DYRKs, two families of kinases involved in pre-mRNA splicing and Alzheimer's disease. Leucettine L41 was co-crystallized with DYRK1A, -2, CLK3 and PIM1. Leucettine L41 inhibits phosphorylation of pre-RNA splicing regulating Ser/Arg-rich proteins. Leucettine L41 modulates alternative pre-mRNA splicing in a cellular systems. The selectivity of Leucettine L41 was extensively characterized. Leucettine L41 provides protection against glutamate-induced cell death in cultured HT22 hippocampal cells. It also provides neuroprotection against APP-induced cell death in mouse brain slices. Finally it prevents in vivo cognitive impairments due to icv injection of amyloid-β 25-35. Leucettines should be further explored as pharmacological tools to study and modulate pre-RNA splicing. Leucettines should also be investigated as potential therapeutic drugs in Alzheimer's disease and in diseases involving abnormal pre-mRNA splicing

    Myxedema Psychosis: Neuropsychiatric Manifestations and Rhabdomyolysis Unmasking Hypothyroidism

    No full text
    Background. Hypothyroidism is a prevalent endocrine disorder, often presenting with a spectrum of symptoms reflecting a hypothyroid state. It is also generally linked to causing mood swings, psychomotor slowing, and fatigue; however, in rare instances, it may lead to or induce acute psychosis, a condition referred to as myxedema psychosis (MP). We report a case of myxedema psychosis and present a literature review discussing its presentation, diagnosis, management, and prognosis. Case Presentation. A 36-year-old lady presented with one-week history of persecutory and paranoid delusions, along with visual and auditory hallucinations. She had no prior history of psychiatric illnesses. She underwent total thyroidectomy three years before the current presentation due to papillary thyroid cancer. She was not on regular follow-up, nor any specific therapy. On examination, she was agitated and violent. There were no signs of myxedema, and the physical exam was unremarkable. The initial workup showed a mild elevation in serum creatinine. Additional investigations revealed a high thyroid-stimulating hormone (TSH) of 56.6 mIU/L, low free T4<0.5 pmol/L, elevated creatine kinase of 3601 U/L, and urine dipstick positive for blood, suggestive of myoglobinuria. MRI of the head was unremarkable. We diagnosed her as a case of myxedema psychosis and mild rhabdomyolysis. She was started on oral thyroxine 100 mcg/day, fluoxetine 20 mg daily, and as-needed haloperidol. She was closely followed and later transferred to the Psychiatry Hospital for further management. Within one week, her symptoms improved completely, and she was discharged off antipsychotics with additional scheduled follow-ups to monitor TFTs and observe for any recurrence. Discussion and Conclusion. Myxedema psychosis is a rare presentation of hypothyroidism—a common endocrine disorder. Scarce data are describing this entity; hence, there is currently a lack of awareness amongst clinicians regarding proper identification and management. Moreover, the atypical nature of presentations occasionally adds to a diagnostic dilemma. Thus, any patient with new-onset psychosis should be screened for hypothyroidism, and awareness of this entity must be emphasized amongst clinicians and guideline makers

    Selectivity, cocrystal structures, and neuroprotective properties of leucettines, a family of protein kinase inhibitors derived from the marine sponge alkaloid leucettamine B.

    No full text
    DYRKs (dual specificity, tyrosine phosphorylation regulated kinases) and CLKs (cdc2-like kinases) are implicated in the onset and development of Alzheimer's disease and Down syndrome. The marine sponge alkaloid leucettamine B was recently identified as an inhibitor of DYRKs/CLKs. Synthesis of analogues (leucettines) led to an optimized product, leucettine L41. Leucettines were cocrystallized with DYRK1A, DYRK2, CLK3, PIM1, and GSK-3β. The selectivity of L41 was studied by activity and interaction assays of recombinant kinases and affinity chromatography and competition affinity assays. These approaches revealed unexpected potential secondary targets such as CK2, SLK, and the lipid kinase PIKfyve/Vac14/Fig4. L41 displayed neuroprotective effects on glutamate-induced HT22 cell death. L41 also reduced amyloid precursor protein-induced cell death in cultured rat brain slices. The unusual multitarget selectivity of leucettines may account for their neuroprotective effects. This family of kinase inhibitors deserves further optimization as potential therapeutics against neurodegenerative diseases such as Alzheimer's disease
    corecore