Singlet Oxygen in Microporous Silica Xerogel:Quantum Yield and Oxidation at the Gas–Solid Interface

The quantum yields of singlet oxygen production and lifetimes at the gas–solid interface in silica gel material are determined. Different photosensitizers (PS) are encapsulated in parallelepipedic xerogel monoliths (PS-SG). PS were chosen according to their known photooxidation properties: 9,10-dicyanoanthracene (DCA), 9,10-anthraquinone (ANT), and a benzophenone derivative, 4-benzoyl benzoic acid (4BB). These experiments are mainly based on time-resolved 1O2 phosphorescence detection, and the obtained FD and tD values are compared with those of a reference sensitizer for production, 1H-phenalen-1- one (PN), included in the same xerogel. The trend between their ability to oxidize organic pollutants in the gas phase and their efficiency for production is investigated through photooxidation experiments of a test pollutant dimethylsulfide (DMS). The FD value is high for DCA-SG relative to the PN reference, whereas it is slightly lower for 4BB-SG and for ANT-SG. FD is related to the production of sulfoxide and sulfone as the main oxidation products for DMS photosensitized oxidation. Additional mechanisms, leading to C!S bond cleaveage, appear to mainly occur for the less efficient singlet oxygen sensitizers 4BB-SG and ANTSG.

(7,9,10)Be elastic scattering and total reaction cross sections on a (12)C target

Elastic scattering angular distributions for (7)Be, (9)Be, and (10)Be isotopes on (12)C target were measured at laboratory energies of 18.8, 26.0, and 23.2 MeV, respectively. The analysis was performed in terms of optical model potentials using Woods-Saxon and double-folding form factors. Also, continuum discretized coupled-channels calculations were performed for (7)Be and (9)Be + (12)C systems to infer the role of breakup in the elastic scattering. For the (10)Be + (12)C system, bound states coupled-channels calculations were considered. Moreover, total reaction cross sections were deduced from the elastic scattering analysis and compared with published data on other weakly and tightly bound projectiles elastically scattered on the (12)C target, as a function of energy.

Singlet molecular oxygen trapping by the fluorescent probe diethyl-3,3 '-(9,10-anthracenediyl)bisacrylate synthesized by the Heck reaction

Singlet molecular oxygen O(2)((1)Delta(g)) is a potent oxidant that can react with different biomolecules, including DNA, lipids and proteins. Many polycyclic aromatic hydrocarbons have been studied as O(2)((1)Delta(g)) chemical traps. Nevertheless, a suitable modification in the polycyclic aromatic ring must be made to increase the yield of O(2)((1)Delta(g)) chemical trapping. With this goal, an anthracene derivative, diethyl-3,3 '-(9,10-anthracenediyl)bisacrylate (DADB), was obtained from the reaction of 9,10-dibromoanthracene and ethyl acrylate through the Heck coupling reaction. The coupling of ethyl acrylate with the anthracene ring produced a new lipophilic, esterified, fluorescent probe reactive toward O(2)((1)Delta(g)). This compound reacts with O(2)((1)Delta(g)) at a rate of k(r) = 1.69 x 10(6) M(-1) s(-1) forming a stable endoperoxide (DADBO(2)), which was characterized by UV-Vis, fluorescence, HPLC/MS and (1)H and (13)C NMR techniques. The photophysical, photochemical and thermostability features of DADB were also evaluated. Furthermore, this compound has the potential for great application in biological systems because it is easily synthetized in large amount and generates specific endoperoxide (DADBO(2)), which can be easily detected by HPLC tandem mass spectrometry (HPLC/MS/MS).

9,10-Dihydroxy-1,8-cineole (1,3,3-Trimethyl-2-oxabicyclo[2.2.2]octane-10,11-diol)

The title compound (3) has been synthesized and its presence sought in the urinary metabolites of the brushtail possum. © CSIRO 2001

Factors associated with arterial stiffness in children aged 9-10 years

OBJECTIVE To analyze the factors associated with stiffness of the great arteries in prepubertal children.METHODS This study with convenience sample of 231 schoolchildren aged 9-10 years enrolled in public and private schools in Vitória, ES, Southeastern Brazil, in 2010-2011. Anthropometric and hemodynamic data, blood pressure, and pulse wave velocity in the carotid-femoral segment were obtained. Data on current and previous health conditions were obtained by questionnaire and notes on the child’s health card. Multiple linear regression was applied to identify the partial and total contribution of the factors in determining the pulse wave velocity values.RESULTS Among the students, 50.2% were female and 55.4% were 10 years old. Among those classified in the last tertile of pulse wave velocity, 60.0% were overweight, with higher mean blood pressure, waist circumference, and waist-to-height ratio. Birth weight was not associated with pulse wave velocity. After multiple linear regression analysis, body mass index (BMI) and diastolic blood pressure remained in the model.CONCLUSIONS BMI was the most important factor in determining arterial stiffness in children aged 9-10 years.

საერთაშორისო კონფერენცია “გეოფიზიკის აქტუალური პრობლემები”, თბილისი, 2013 წ. 9-10 დეკემბერი

წინამდებარე კრებულში შესულია მ. ნოდიას გეოფიზიკის ინსტიტუტის 80 წლისადმი მიძღვნილი სამეცნიერო კონფერენციის, “გეოფიზიკის აქტუალური პრობლემები”, მასალები. კრებული განკუთვნილია გეოფიზიკურ მეცნიერებათა სხვადასხვა დარგში მომუშავე სპეციალისტებისათვის.

Footnotes, September/October 2002, Vol.26 no.9/10

Monthly newletters for the State Library of Iowa

Footnotes, September-October 2004, Vol. 28, no. 9-10

Monthly newsletter of the State Library

Footnotes, September/October 2005, Vol. 29, no. 9/10

Monthly newsletter of the State Library

Eduskunnan Puhemies V.J. Sukselainen 9/10 1975

Kirje 9.10.1975