206 research outputs found
From the microcosm of the atomic nuclei to the macrocosm of the stars
A necessary condition for the reliable modelling of the structure or
evolution of the stars and of their concomitant nucleosynthesis is the
availability of good quality nuclear data in a very wide area of the chart of
nuclides. This short review presents a non-exhaustive list of nuclear data of
astrophysics interest (masses, -decays, thermonuclear and
non-thermonuclear reaction rates) for nuclides at the bottom of the valley of
nuclear stability (mainly involved in the modelling of non-explosive phases of
stellar evolution), or for more or less highly exotic nuclides (to be
considered in the description of stellar explosions). Special emphasis is put
on the importance of providing quality nuclear data bases that can be easily
used by astrophysicists.Comment: 6 pages, To appear in Proceedings of International Conference on
Nuclear Data for Science and Technology 2007 (ND2007), Nice, Franc
Direct triple- process in non-adiabatic approach
Triple- reaction rates have been determined well with the sequential
process via the narrow resonances. However, the direct triple- process
at off-resonant energies still remains in unsolved problems. In the present
report, the direct triple- contribution is estimated with a
non-adiabatic method, and it is found to be 10--10 pb order in
photodisintegration cross sections of C(2 0) for
MeV. This is far below the values predicted by the recent
adiabatic models. In spite of the large difference, the derived rates are found
to be concordant with NACRE at the helium burning temperatures.Comment: 4 pages, 2 figures; Proceedings of 16th International Symposium on
Origin of Matter and Evolution of Galaxies (OMEG16), 25-28 October 2022,
Hanoi, Vietna
Theoretical photo-disintegration of O
The photodisintegration of O is predicted to be dominated by 2
excitation in the vicinity of the -particle threshold.
The reaction rates of C(,)O are expected to be
determined from this reaction.Comment: 3 pages, 2 figures, Proceedings of Nuclei in the Cosmos (NIC-XIV).
19-24 June 2016, Niigata, Japa
Farnesoid X Receptor Deficiency Improves Glucose Homeostasis in Mouse Models of Obesity
International audienceOBJECTIVE Bile acids (BA) participate in the maintenance of metabolic homeostasis acting through different signaling pathways. The nuclear BA receptor farnesoid X receptor (FXR) regulates pathways in BA, lipid, glucose, and energy metabolism, which become dysregulated in obesity. However, the role of FXR in obesity and associated complications, such as dyslipidemia and insulin resistance, has not been directly assessed. RESEARCH DESIGN AND METHODS Here, we evaluate the consequences of FXR deficiency on body weight development, lipid metabolism, and insulin resistance in murine models of genetic and diet-induced obesity. RESULTS FXR deficiency attenuated body weight gain and reduced adipose tissue mass in both models. Surprisingly, glucose homeostasis improved as a result of an enhanced glucose clearance and adipose tissue insulin sensitivity. In contrast, hepatic insulin sensitivity did not change, and liver steatosis aggravated as a result of the repression of β-oxidation genes. In agreement, liver-specific FXR deficiency did not protect from diet-induced obesity and insulin resistance, indicating a role for nonhepatic FXR in the control of glucose homeostasis in obesity. Decreasing elevated plasma BA concentrations in obese FXR-deficient mice by administration of the BA sequestrant colesevelam improved glucose homeostasis in a FXR-dependent manner, indicating that the observed improvements by FXR deficiency are not a result of indirect effects of altered BA metabolism. CONCLUSIONS Overall, FXR deficiency in obesity beneficially affects body weight development and glucose homeostasis
Support for UNRWA's survival
The United Nations Relief and Works Agency for Palestine Refugees in the Near East (UNRWA) provides life-saving humanitarian aid for 5·4 million Palestine refugees now entering their eighth decade of statelessness and conflict. About a third of Palestine refugees still live in 58 recognised camps. UNRWA operates 702 schools and 144 health centres, some of which are affected by the ongoing humanitarian disasters in Syria and the Gaza Strip. It has dramatically reduced the prevalence of infectious diseases, mortality, and illiteracy. Its social services include rebuilding infrastructure and homes that have been destroyed by conflict and providing cash assistance and micro-finance loans for Palestinians whose rights are curtailed and who are denied the right of return to their homeland
Fabrication of Functionalized Double-Lamellar Multifunctional Envelope-Type Nanodevices Using a Microfluidic Chip with a Chaotic Mixer Array
Multifunctional envelope-type nanodevices (MENDs) are very promising non-viral gene delivery vectors because they are biocompatible and enable programmed packaging of various functional elements into an individual nanostructured liposome. Conventionally MENDs have been fabricated by complicated, labor-intensive, time-consuming bulk batch methods. To avoid these problems in MEND fabrication, we adopted a microfluidic chip with a chaotic mixer array on the floor of its reaction channel. The array was composed of 69 cycles of the staggered chaotic mixer with bas-relief structures. Although the reaction channel had very large Péclet numbers (>105) favorable for laminar flows, its chaotic mixer array led to very small mixing lengths (<1.5 cm) and that allowed homogeneous mixing of MEND precursors in a short time. Using the microfluidic chip, we fabricated a double-lamellar MEND (D-MEND) composed of a condensed plasmid DNA core and a lipid bilayer membrane envelope as well as the D-MEND modified with trans-membrane peptide octaarginine. Our lab-on-a-chip approach was much simpler, faster, and more convenient for fabricating the MENDs, as compared with the conventional bulk batch approaches. Further, the physical properties of the on-chip-fabricated MENDs were comparable to or better than those of the bulk batch-fabricated MENDs. Our fabrication strategy using microfluidic chips with short mixing length reaction channels may provide practical ways for constructing more elegant liposome-based non-viral vectors that can effectively penetrate all membranes in cells and lead to high gene transfection efficiency
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