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Reductive openings of benzylidene acetals revisited: a mechanistic scheme for regio- and stereoselectivity.

Despite the importance of regioselective reductive openings of cyclic acetals, mechanistic details are scarce. In this study 4,6-O-benzylidene acetals were used as model compounds for deciphering the mechanism of regioselective openings using a variety of reducing agents. Competitive isotopic studies aiming at primary and secondary isotope effects, as well as an electron-deficient substrate, were

The leaf-level emission factor of volatile isoprenoids: caveats, model algorithms, response shapes and scaling

In models of plant volatile isoprenoid emissions, the instantaneous compound emission rate typically scales with the plant's emission potential under specified environmental conditions, also called as the emission factor, ES. In the most widely employed plant isoprenoid emission models, the algorithms developed by Guenther and colleagues (1991, 1993), instantaneous variation of the steady-state em

Randomised controlled trial for emphysema with a selective agonist of the gamma-type retinoic acid receptor

Palovarotene is an oral gamma-selective retinoid agonist. In animal emphysema models, palovarotene reduced inflammation, promoted structural repair and functional improvement. REPAIR (Retinoid treatment of Emphysema in Patients on the alpha(1)-antitrypsin International Registry), was an investigator-initiated, double-blind, placebo-controlled randomised study to assess the safety and efficacy of 5

Vicariance and marine migration in continental island populations of a frog endemic to the Atlantic Coastal forest

The theory of island biogeography is most often studied in the context of oceanic islands where all island inhabitants are descendants from founding events involving migration from mainland source populations. Far fewer studies have considered predictions of island biogeography in the case of continental islands, where island formation typically splits continuous populations and thus vicariance al

Gas-phase dehydration of glycerol to acrolein over Al2O3-, SiO2- and TiO2-supported Nb- and W-oxide catalysts

Hypothetical monolayers loadings of niobium and tungsten oxide supported on alumina, silica and titania were investigated as catalysts for the dehydration of glycerol to produce acrolein. Besides activity measurements, to have information about the supported structures the catalysts were characterized by XRD, Raman spectroscopy, XPS, XANES and FTIR combined with adsorption of pyridine and CO2. Com

Anthropometric measures and bladder cancer risk: A prospective study in the EPIC cohort

Anthropometric measures have been related to risk of several cancers. For bladder cancer, however, evidence is sparse. Comparability of existing studies is hampered by use of different obesity-measures, inadequate control for smoking, and few female cases. This study examined associations between height, weight, waist and hip circumference, waist-hip ratio, waist-height ratio, body mass index (BMI

A beta 1-15/16 as a Potential Diagnostic Marker in Neurodegenerative Diseases

Cerebrospinal fluid (CSF) biomarkers for Alzheimer's disease (AD) reflect brain biochemistry. Using combined immunoprecipitation and mass spectrometry, we have shown that amyloid beta 1-15 (A beta 1-15) is produced by concerted beta- and alpha-secretase cleavage of amyloid precursor protein (APP) and that the relative levels of A beta 1-16 in AD compared to controls are increased. Furthermore, dru

Null Referential Subjects in Övdalian

In this article, Övdalian null subjects are introduced and analysed. A general background to Övdalian is provided, whereupon the possible null subjects (wįð ('we') and ið ('you')) are presented. Interestingly, these null subjects do not appear in the same syntactic positions; whereas null ið seems to be unrestricted, null wįð may only appear in positions immediately preceding the finite verb. It i

Endovascular Technique for Arterial Shunting to Prevent Intraoperative Ischemia.

The use of an intraoperative shunt is an established technique used to reduce the ischemic time after acute arterial obstruction or in the prevention of hypoperfusion due to complex open vascular or endovascular operative procedures. To date, described methods of temporary extremity blood perfusion have required open surgical techniques.

snoRNPs Regulate Telomerase Activity in Neuroblastoma and Are Associated with Poor Prognosis.

Amplification of the MYCN oncogene is strongly associated with poor prognosis in neuroblastoma (NB). In addition to MYCN amplification, many studies have focused on identifying patients with a poor prognosis based on gene expression profiling. The majority of prognostic signatures today are comprised of large gene lists limiting their clinical application. In addition, although of prognostic signi

Impact of gene dosage, loss of wild-type allele, and FLT3 ligand on Flt3-ITD-induced myeloproliferation

Acquisition of homozygous activating growth factor receptor mutations might accelerate cancer progression through a simple gene-dosage effect. Internal tandem duplications (ITDs) of FLT3 occur in approximately 25% cases of acute myeloid leukemia and induce ligand-independent constitutive signaling. Homozygous FLT3-ITDs confer an adverse prognosis and are frequently detected at relapse. Using a mou

Search for nonpointing photons in the diphoton and E-T(miss) final state in root s=7 TeV proton-proton collisions using the ATLAS detector

A search has been performed for photons originating in the decay of a neutral long-lived particle, exploiting the capabilities of the ATLAS electromagnetic calorimeter to make precise measurements of the flight direction of photons, as well as the calorimeter's excellent time resolution. The search has been made in the diphoton plus missing transverse energy final state, using the full data sample

Testing for Predictability in Conditionally Heteroskedastic Stock Returns

The difficulty of predicting stock returns has recently motivated researchers to start looking for more powerful tests, and the current paper takes a step in this direction. Unlike existing tests, the test proposed here exploits the information contained in the heteroskedasticity of findings, which is expected to lead to higher power, a result that is confirmed by our results. In order to also mai

Paediatricians' referral preference of patients with embolised intravascular foreign bodies: a survey-based study

Background: Central line insertion is a routine procedure in medical practice. Dislodgement of lines into the vascular system is a rare complication. We noticed that paediatric health care providers (PHCP) contact the cardiac or general paediatric surgeon for extraction of dislodged lines more frequently than using the less invasive percutaneous approach. Aim: To study the referral preference of P

Overview of the synoptic and pollution situation over Europe during the EUCAARI-LONGREX field campaign

In May 2008 the EUCAARI-LONGREX aircraft field campaign was conducted within the EUCAARI intensive observational period. The campaign aimed at studying the distribution and evolution of air mass properties on a continental scale. Airborne aerosol and trace gas measurements were performed aboard the German DLR Falcon 20 and the British FAAM B.4e-146 aircraft. This paper outlines the meteorological

Self-assembled quantum dots in a nanowire system for quantum photonics

Quantum dots embedded within nanowires represent one of the most promising technologies for applications in quantum photonics. Whereas the top-down fabrication of such structures remains a technological challenge, their bottom-up fabrication through self-assembly is a potentially more powerful strategy. However, present approaches often yield quantum dots with large optical linewidths, making repr

Hygroscopic growth and cloud forming potential of Arctic aerosol based on observed chemical and physical characteristics (a 1 year study 2007-2008)

Aerosol particle samples were collected, and the particle size distribution was measured during 1 year at the Zeppelin station (474 m asl) on Svalbard. The chemical constituents, hygroscopicity, and cloud forming properties of the aerosol were analyzed. The aerosol contained mostly sulfate and nitrate during the summer, whereas from September to February the main components were sodium and chlorid

Trait matching of flower visitors and crops predicts fruit set better than trait diversity

Understanding the relationships between trait diversity, species diversity and ecosystem functioning is essential for sustainable management. For functions comprising two trophic levels, trait matching between interacting partners should also drive functioning. However, the predictive ability of trait diversity and matching is unclear for most functions, particularly for crop pollination, where in

Bioinspired Citrate-Apatite Nanocrystals Doped with Divalent Transition Metal Ions

Bioinspired citrate-carbonate-apatite (cAp) nanocrystals doped with divalent transition metal (M) ions, i.e., Mn2+, Co2+, and Ni2+, were prepared by batch thermal decomplexing of Ca2+/M/citrate/phosphate/carbonate solutions at 80 and 37 degrees C, with initial Ca2+/M molar ratios of 9:1 and 5:5, and at different crystallization times ranging from 1 to 96 h. A thorough chemical, crystallographic, a