10 research outputs found
Determination of the liquid-phase speciation in the MDEA-H2O-CO2 system
AbstractAqueous solutions of alkanolamines are commonly used in CO2 capture processes. To describe these complex processes rigorous mass transfer models are needed, in which all mass transfer, kinetics and thermodynamics are incorporated correctly. To improve the quality of the thermodynamic models, not only commonly used P-α (CO2 partial pressure versus CO2 liquid loading) experimental data, but also liquid phase speciation data are important. Speciation data of amine-H2O-CO2 data are very scarce in literature. In this work speciation data of MDEA-H2O-CO2 have been determined experimentally with a Fourier Transform Infra-Red spectrometer (FTIR) at ambient temperature. After several calibration lines were prepared, the speciation of this system was determined online in the FTIR. The experimental data presented in this work were well in line with speciation from open literature
The genetics of the mood disorder spectrum:genome-wide association analyses of over 185,000 cases and 439,000 controls
Background
Mood disorders (including major depressive disorder and bipolar disorder) affect 10-20% of the population. They range from brief, mild episodes to severe, incapacitating conditions that markedly impact lives. Despite their diagnostic distinction, multiple approaches have shown considerable sharing of risk factors across the mood disorders.
Methods
To clarify their shared molecular genetic basis, and to highlight disorder-specific associations, we meta-analysed data from the latest Psychiatric Genomics Consortium (PGC) genome-wide association studies of major depression (including data from 23andMe) and bipolar disorder, and an additional major depressive disorder cohort from UK Biobank (total: 185,285 cases, 439,741 controls; non-overlapping N = 609,424).
Results
Seventy-three loci reached genome-wide significance in the meta-analysis, including 15 that are novel for mood disorders. More genome-wide significant loci from the PGC analysis of major depression than bipolar disorder reached genome-wide significance. Genetic correlations revealed that type 2 bipolar disorder correlates strongly with recurrent and single episode major depressive disorder. Systems biology analyses highlight both similarities and differences between the mood disorders, particularly in the mouse brain cell-types implicated by the expression patterns of associated genes. The mood disorders also differ in their genetic correlation with educational attainment – positive in bipolar disorder but negative in major depressive disorder.
Conclusions
The mood disorders share several genetic associations, and can be combined effectively to increase variant discovery. However, we demonstrate several differences between these disorders. Analysing subtypes of major depressive disorder and bipolar disorder provides evidence for a genetic mood disorders spectrum
Integrated analysis of environmental and genetic influences on cord blood DNA methylation in new-borns
Epigenetic processes, including DNA methylation (DNAm), are among the mechanisms allowing integration of genetic and environmental factors to shape cellular function. While many studies have investigated either environmental or genetic contributions to DNAm, few have assessed their integrated effects. Here we examine the relative contributions of prenatal environmental factors and genotype on DNA methylation in neonatal blood at variably methylated regions (VMRs) in 4 independent cohorts (overall n = 2365). We use Akaike’s information criterion to test which factors best explain variability of methylation in the cohort-specific VMRs: several prenatal environmental factors (E), genotypes in cis (G), or their additive (G + E) or interaction (GxE) effects. Genetic and environmental factors in combination best explain DNAm at the majority of VMRs. The CpGs best explained by either G, G + E or GxE are functionally distinct. The enrichment of genetic variants from GxE models in GWAS for complex disorders supports their importance for disease risk
Kinetics of absorption of carbon dioxide in aqueous MDEA solutions with carbonic anhydrase at 298 K
In present work the absorption of carbon dioxide in aqueous N-methyldiethanolamine (MDEA) solutions with and without the enzyme carbonic anhydrase has been studied in a stirred cell at 298 K, with MDEA concentrations ranging from 0.5 to 4 kmol m−3 and carbonic anhydrase concentrations ranging from 0 to 2275 g m−3, respectively. The obtained experimental results show that carbonic anhydrase significantly enhances the absorption of carbon dioxide in aqueous MDEA solution. When the enzyme is present in the absorption solution, MDEA concentration does not materially influence on the absorption rate. Therefore, the enzyme does not enhance the reaction of CO2 with MDEA, since the rate of this reaction is a function of the MDEA concentration. Rather, the enzyme enhances the reaction of carbon dioxide with water. In the presence of enzyme this reaction is not only first order in CO2, but also first order in water. Thus, carbonic anhydrase may provide a solution for the efficient capture of carbon dioxide from flue gases by significantly increasing the kinetics of its absorption in MDEA, a tertiary amine which requires less energy for regeneration than monoethanolamine (MEA), the current industry benchmark.
Carbon dioxide removal by alkanolamines in aqueous organic solvents. A method for enhancing the desorption process
Process concepts of using alkanolamines in aqueous organic solvents have been evaluated by experimental work and process simulations using the Procede Process Simulator. N-methyldiethanolamine (MDEA), methanol, and ethanol were chosen as the respective alkanolamine and organic compounds in the current work.
In previous work, the dissociation constants of protonated MDEA at infinite dilution in methanol–water and ethanol–water solvents and the initial mass transfer rates of CO2 in 3 kmol m-3 MDEA in methanol–water and ethanol–water solvents were determined. In the current work, experimental values of the CO2 vapor liquid equilibria in 3 kmol m-3 MDEA have been determined in methanol-water and ethanol-water solvents.
The experimentally determined results have been implemented into the Procede Process Simulator, which has been used to simulate a CO2 removal plant with 90% CO2 removal based on the specification of the flue gas of an 827 MWe pulverized coal fired power plant. A solvent of 3 kmol m-3 MDEA in aqueous methanol solution was considered for conceptual purposes. The results indicatively show a maximum decrease in the reboiler duty of the desorber of about 7.5% at methanol fractions of about 0.06 compared to purely aqueous solutions and a reboiler temperature decrease with increasing methanol fractions. Further experimental results are, however, necessary in order to more precisely simulate CO2 removal processes by alkanolamines in aqueous organic solvents.
Diffusion Coefficients of N2O in Aqueous Piperazine Solutions Using the Taylor Dispersion Technique from (293 to 333) K and (0.3 to 1.4) mol·dm−3
The diffusion coefficients of N2O in aqueous piperazine (PZ) solutions have been determined using the Taylor dispersion technique over a temperature range from (293 to 333) K and a concentration range from (0.3 to 1.4) mol·dm−3 PZ. The experimental results have been compared to literature values. Diffusion coefficients of N2O in aqueous PZ solutions can be estimated by using a modified Stokes−Einstein relation with sufficient accuracy for engineering purposes. The diffusion coefficient of CO2 in an aqueous PZ solution can be estimated by means of the “N2O analogy”. The use of the Taylor dispersion technique for determination of gas diffusivities in liquids is given in detail
Carbon dioxide removal by alkanolamines in aqueous organic solvents. A method for enhancing the desorption process
Targeted Apoptosis of Senescent Cells Restores Tissue Homeostasis in Response to Chemotoxicity and Aging
Accession Number: GSE94395 Platform: GPL16791: Illumina HiSeq 2500 (Homo sapiens) Organism: Homo sapiens Published on 2017-03-01 Summary: The accumulation of irreparable cellular damage restricts healthy lifespan after acute stress or natural aging. Senescent cells are thought to impair tissue function and their genetic clearance can successfully delay features of aging. Identifying how senescent cells avoid apoptosis would allow for the prospective design of anti-senescence compounds to address whether homeostasis can be restored. Here, we identify FOXO4 as a pivot in the maintenance of senescent cell viability. We designed a FOXO4-based peptide which selectively competes for interaction of FOXO4 with p53. In senescent cells, this results in p53 nuclear exclusion and cell-intrinsic apoptosis. Importantly, under conditions where it was well tolerated, the FOXO4 peptide restored liver function after Doxorubicin-induced chemotoxicity. Moreover, in fast aging XpdTTD/TTD, as well as in naturally aged mice the FOXO4 peptide could counteract the loss of fitness, fur density and renal function. Thus, it is possible to therapeutically target senescent cells and thereby effectively counteract senescence-associated loss of tissue homeostasis. Overall Design: mRNA expression levels are compared between IR-induced senescent and proliferating IMR90 cells in triplicate Contact: Name: Peter L.J. de Keizer Organization: Erasmus University Medical Center Laboratory: Senescence in Cancer and Aging Deparment: Molecular Genetics Address: Wytemaweg 80 Rotterdam Netherlands Email: [email protected] Organization: GEO Address: US
Targeted Apoptosis of Senescent Cells Restores Tissue Homeostasis in Response to Chemotoxicity and Aging
Accession Number: GSE94395 Platform: GPL16791: Illumina HiSeq 2500 (Homo sapiens) Organism: Homo sapiens Published on 2017-03-01 Summary: The accumulation of irreparable cellular damage restricts healthy lifespan after acute stress or natural aging. Senescent cells are thought to impair tissue function and their genetic clearance can successfully delay features of aging. Identifying how senescent cells avoid apoptosis would allow for the prospective design of anti-senescence compounds to address whether homeostasis can be restored. Here, we identify FOXO4 as a pivot in the maintenance of senescent cell viability. We designed a FOXO4-based peptide which selectively competes for interaction of FOXO4 with p53. In senescent cells, this results in p53 nuclear exclusion and cell-intrinsic apoptosis. Importantly, under conditions where it was well tolerated, the FOXO4 peptide restored liver function after Doxorubicin-induced chemotoxicity. Moreover, in fast aging XpdTTD/TTD, as well as in naturally aged mice the FOXO4 peptide could counteract the loss of fitness, fur density and renal function. Thus, it is possible to therapeutically target senescent cells and thereby effectively counteract senescence-associated loss of tissue homeostasis. Overall Design: mRNA expression levels are compared between IR-induced senescent and proliferating IMR90 cells in triplicate Contact: Name: Peter L.J. de Keizer Organization: Erasmus University Medical Center Laboratory: Senescence in Cancer and Aging Deparment: Molecular Genetics Address: Wytemaweg 80 Rotterdam Netherlands Email: [email protected] Organization: GEO Address: US