Neutron spectroscopy of 26Mg states : Constraining the stellar neutron source 22Ne(α,n)25Mg

This work reports on accurate, high-resolution measurements of the 25Mg(n,γ)26Mg and 25Mg(n,tot) cross sections in the neutron energy range from thermal to about 300 keV, leading to a significantly improved 25Mg(n,γ)26Mg parametrization. The relevant resonances for n+25Mg were characterized from a combined R-matrix analysis of the experimental data. This resulted in an unambiguous spin/parity assignment of the corresponding excited states in 26Mg. With this information experimental upper limits of the reaction rates for 22Ne(α,n)25Mg and 22Ne(α,γ)26Mg were established, potentially leading to a significantly higher (α,n)/(α,γ) ratio than previously evaluated. The impact of these results has been studied for stellar models in the mass range 2 to 25 M⊙

Insulin and estrogen independently and differentially reduce macronutrient intake in healthy men.

Context: Insulin administration to the central nervous system inhibits food intake, but this effect has been found to be less pronounced in female compared with male organisms. This sex-specific pattern has been suggested to arise from a modulating influence of estrogen signaling on the insulin effect. Objective: We assessed in healthy young men whether pretreatment with transdermal estradiol interacts with the hypophagic effect of central nervous insulin administration via the intranasal pathway. Design, Setting, Participants, and Intervention: According to a 2×2 design, two groups of men (n = 16 in each group) received a 3-day transdermal estradiol (100 µg/24 h) or placebo pretreatment and on two separate mornings were intranasally administered 160 IU regular human insulin or placebo. Main Outcome Measures: We assessed free-choice ad libitum calorie intake from a rich breakfast buffet and relevant blood parameters in samples collected before and after breakfast. Results: Estrogen treatment induced a 3.5-fold increase in serum estradiol concentrations and suppressed serum testosterone concentrations by 70%. Independent of estradiol administration, intranasal insulin reduced the intake of carbohydrates during breakfast, attenuating in particular the consumption of sweet, palatable foods. Estradiol treatment per se decreased protein consumption. We did not find indicators of eating-related interactions between both hormones. Conclusions: Results indicate that, in an acute setting, estrogen does not interact with central nervous insulin signaling in the control of eating behavior in healthy men. Insulin and estradiol rather exert independent inhibiting effects on macronutrient intake

Entwicklung eines verputzten Zelluloseabsorbers

Im Rahmen von abgeschlossenen Forschungsprojekten wurde die überwiegend als Einblasdämmstoff verwendete Altpapierzellulosedämmung zu einem tragfähigen, verputzbaren Wandsystem entwickelt, das als thermische Innendämmung ohne Dampfsperre einsetzbar ist. Dabei wurden die positiven Eigenschaften des Materials weiterentwickelt, so dass ein tragfähiger und mittels Spezialputz verputzbarer Dämmkörper zur Verfügung steht. Der Vortrag berichtet über ein laufendes Projekt, in dem der verputzbare Zellulosedämmkörper zu einem akustischen Absorber weiterentwickelt wird, der vor allem im mitten- und tieffrequenten Bereich wirksam sein soll. Basierend auf dem Prinzip des klassischen Schlitzabsorbers wird auf einer 5 bis 6 cm dicken vor Ort aufgespritzten Zelluloseschicht ein zweischichtiges Putzsystem aufgebracht, das -als Innovation bei Schlitzabsorbern- auch mit einer fugenlosen Oberfläche ausgeführt werden kann. Damit wird dem Bedarf vieler Planer nach 'Unsichtbarkeit' der akustischen Maßnahmen bei gleichzeitiger Bedämpfung tiefer Frequenzen Rechnung getragen. Aufgrund des positiven hygrothermischen Verhaltens kann der verputzte Zelluloseabsorber auch an der Innenseite von Außenwänden eingesetzt werden, wo konventionelle Absorber Probleme mit unzulässiger Wasserdampfkondensation hervorrufen können. Der neuartige Absorber ist auch auf unebenen oder gekrümmten Wänden oder Decken applizierbar. Der Einsatz des verputzten Zelluloseabsorbers zur akustischen Sanierung eines Klassenzimmers wird vorgestellt

The effect of polymer backbone chemistry on the induction of the accelerated blood clearance in polymer modified liposomes

A variety of water-soluble polymers, when attached to a liposome, substantially increase liposome circulation half-life in animals. However, in certain conditions, liposomes modified with the most widely used polymer, polyethylene glycol (PEG), induce an IgM response resulting in an accelerated blood clearance (ABC) of the liposome upon the second injection. Modification of liposomes with other water-soluble polymers: HPMA (poly[N-(2-hydroxypropyl) methacrylamide]), PVP (poly(vinylpyrrolidone)), PMOX (poly(2-methyl-2-oxazoline)), PDMA (poly(N,N-dimethyl acrylamide)), and PAcM (poly(N-acryloyl morpholine)), increase circulation times of liposomes; but a precise comparison of their ability to promote long circulation or induce the ABC effect has not been reported. To obtain a more nuanced understanding of the role of polymer structure/MW to promote long circulation, we synthesized a library of polymer diacyl chain lipids with low polydispersity (1.04–1.09), similar polymer molecular weights (2.1–2.5 kDa) and incorporated them into 100 nm liposomes of a narrow polydispersity (0.25–1.3) composed of polymer-lipid/hydrogenated soy phosphatidylcholine/cholesterol/diD: 5.0/54.5/40/0.5. We confirm that HPMA, PVP, PMOX, PDMA and PAcM modified liposome have increased circulation times in rodents and that PVP, PDMA, PAcM do not induce the ABC effect. We demonstrate for the first time, that HPMA does not cause an ABC effect whereas PMOX induces a pronounced ABC effect in rats. We find that a single dose of liposomes coated with PEG and PMOX generate an IgM response in rats towards the respective polymer. Finally, in this homologous polymer series, we observe a positive correlation (R = 0.84 in rats, R = 0.92 in mice) between the circulation time of polymer-modified liposomes and polymer viscosity; PEG and PMOX, the polymers that can initiate an ABC response were the two most viscous polymers. Our findings suggest that that polymers that do not cause an ABC effect such as, HPMA or PVP, deserve further consideration as polymer coatings to improve the circulation of liposomes and other nanoparticles