12 research outputs found
Experimental and Kinetic Modeling Studies on the Conversion of Sucrose to Levulinic Acid and 5-Hydroxymethylfurfural Using Sulfuric Acid in Water
We
here report experimental and kinetic modeling studies on the
conversion of sucrose to levulinic acid (LA) and 5-hydroxymethylfurfural
(HMF) in water using sulfuric acid as the catalyst. Both compounds
are versatile building blocks for the synthesis of various biobased
(bulk) chemicals. A total of 24 experiments were performed in a temperature
window of 80–180 °C, a sulfuric acid concentration between
0.005 and 0.5 M, and an initial sucrose concentration between 0.05
and 0.5 M. Glucose, fructose, and HMF were detected as the intermediate
products. The maximum LA yield was 61 mol %, obtained at 160 °C,
an initial sucrose concentration of 0.05 M, and an acid concentration
of 0.2 M. The maximum HMF yield (22 mol %) was found for an acid concentration
of 0.05 M, an initial sucrose concentration of 0.05 M, and a temperature
of 140 °C. The experimental data were modeled using a number
of possible reaction networks. The best model was obtained when using
a first order approach in substrates (except for the reversion of
glucose) and agreement between experiment and model was satisfactorily.
The implication of the model regarding batch optimization is also
discussed
Experimental and Kinetic Modeling Studies on the Conversion of Sucrose to Levulinic Acid and 5Hydroxymethylfurfural Using Sulfuric Acid in Water
Raman study of single wall carbon nanotube thin films treated by laser irradiation and dynamic and isothermal oxidation
Dominant-negative NFKBIA mutation promotes IL-1β production causing hepatic disease with severe immunodeficiency
Although IKK-β has previously been shown as a negative regulator of IL-1β secretion in mice, this role has not been proven in humans. Genetic studies of NF-κB signaling in humans with inherited diseases of the immune system have not demonstrated the relevance of the NF-κB pathway in suppressing IL-1β expression. Here, we report an infant with a clinical pathology comprising neutrophil-mediated autoinflammation and recurrent bacterial infections. Whole-exome sequencing revealed a de novo heterozygous missense mutation of NFKBIA, resulting in a L34P IκBα variant that severely repressed NF-κB activation and downstream cytokine production. Paradoxically, IL-1β secretion was elevated in the patient’s stimulated leukocytes, in her induced pluripotent stem cell–derived macrophages, and in murine bone marrow–derived macrophages containing the L34P mutation. The patient’s hypersecretion of IL-1β correlated with activated neutrophilia and liver fibrosis with neutrophil accumulation. Hematopoietic stem cell transplantation reversed neutrophilia, restored a resting state in neutrophils, and normalized IL-1β release from stimulated leukocytes. Additional therapeutic blockade of IL-1 ameliorated liver damage, while decreasing neutrophil activation and associated IL-1β secretion. Our studies reveal a previously unrecognized role of human IκBα as an essential regulator of canonical NF-κB signaling in the prevention of neutrophil-dependent autoinflammatory diseases. These findings also highlight the therapeutic potential of IL-1 inhibitors in treating complications arising from systemic NF-κB inhibition