Laser operation of Yb3+ in the acentric RbTiOPO4 codoped with Nb5+

We report on continuous-wave lasing of Yb(3+) at room temperature in the noncentrosymmetric RbTiOPO(4) crystal, codoped with Nb(5+), for all three possible polarizations. A maximum output power of 154 mW at 1050 nm was obtained for an absorbed power of 386 mW. The highest slope efficiency reached approximately 60% and the lowest threshold (with respect to the absorbed power) was 18 mW. The laser was tunable from 1009 to 1081 nm.     

Efficient high-power laser operation of Yb:KLu(WO4)2 crystals cut along the principal optical axes

High-power continuous-wave laser operation was demonstrated with Yb:KLu(WO(4))(2) crystals cut along the N(p), N(m), and N(g) principal optical axes, achieving a nearly equal slope efficiency of 79%-80% in the absence of thermal effects. The N(g)-cut crystal proved to be the most advantageous for power scaling as well as efficient pumping. A maximum output power of 11.0 W was produced from a 2 mm thick uncoated N(g)-cut crystal in a approximately 7 mm long plano-concave resonator end pumped by a fiber-coupled diode; the corresponding optical-to-optical efficiency was 68%.     

Chromatographic and electrophoretic methods for the analysis of biomarkers of oxidative damage to macromolecules (DNA, lipids, and proteins)

Free radicals and other reactive species can cause oxidative damage to biomolecules when oxidant species exceed the antioxidant defences in the body, resulting in oxidative stress. Oxidatively damaged products have been associated with aging as well as with the development of pathologies like cancer, cardiovascular disease, neurodegenerative disorders, diabetes, inflammation, etc. Reliable measurements of biomarkers of oxidative damage to macromolecules would afford information on the pre-disposition and prognosis of certain pathologies, being of utmost importance in evaluation of the effect of intervention with antioxidants on the incidence of diseases associated to oxidative stress. This review will present and compare different analytical methods, especially those involving chromatographic and electrophoretic techniques, commonly used for the analysis of biomarkers of oxidative damage to the three main macromolecules, namely oxidised DNA, lipid peroxidation products, and protein carbonyls.     

Efficient thin-disk Tm-laser operation based on Tm:KLu(WO4)2/KLu(WO4)2 epitaxies

A diode-pumped thin-disk laser based on Tm:KLu(WO4)2/KLu(WO4)2 epitaxies is realized. The emission is in the 1850-1945 nm spectral range for Tm-doping between 5 and 15 at. %. The maximum slope efficiency of 47% with respect to the absorbed power obtained with 5 at. % Tm:KLu(WO4)2/KLu(WO4)2 corresponds to a maximum output power of ~6 W in cw operation.     

Bistable laser operation of a Yb0.0054:Y0.3481Gd0.6465VO4 mixed crystal

Spectroscopic properties and cw laser performance of a new Yb0.0054:Y0.3481Gd0.6465VO4 mixed crystal are reported. A sizable bistability is displayed in the laser operation with a bistability range of 1.9-3.4 W in terms of absorbed pump power, in which the coexistence and switching of the sigma and pi polarization states occur accompanied by wavelength shifting upon decreasing the pump power.     

Green and scalable procedure for extremely fast ligandless Suzuki–Miyaura cross-coupling reactions in aqueous IPA using solid-supported Pd in continuous flow

An environmentally friendly continuous-flow protocol for the Suzuki coupling of boronic acids and aryl halides under ligand-free conditions using solid-supported Pd is presented. The process described herein uses very simple reaction conditions and equipment setup and can be readily scaled up to provide multigram quantities of products containing low levels of residual Pd.     

99mTc Radiolabeling and Biological Evaluation of Nanoparticles Functionalized with a Versatile Coating Ligand

Radiolabeling allows noninvasive imaging by single photon emission computed tomography (SPECT) or positron emission tomography (PET) for assessing the biodistribution of nanostructures. Herein, the synthesis of a new coating ligand for gold nanoparticles (AuNPs) and quantum dots (QDs) is reported. This ligand is multifunctional; it combines the metal chelate with conjugating functions to biological vectors. The concept allows the coupling of any targeting function to the chelator; an example for the prostate specific membrane antigen is given. Derivatized NPs can directly be labeled in one step with [^99mTc(OH₂)₃(CO)₃]⁺. AuNPs in particular are highly stable, a prerequisite for in vivo studies excluding misinterpretation of the biodistribution data. AuNPs with differing sizes (7 and 14 nm core diameter) were administered intravenously into nude NMRI mice bearing LNCaP xenografts. MicroSPECT images show for both probes rapid clearance from the blood pool through the hepatobiliary pathway. The 7 nm AuNPs revealed a significantly higher bone uptake than the 14 nm AuNPs. The high affinity towards bone mineral is further confirmed in vitro with hydroxyapatite.     

New photopolymer with trifunctional monomer for holographic applications

New holographic recording materials based on photopolymerizable systems have contributed significantly to the recent growth of holographic applications. Previously, we reported that in photopolymerizable systems with a difunctional monomer, Ethylene Glycol DiMethAcrylate (EGDMA) improves the behaviour of the system and explains the role played by an eosin ester that has an oxo-oxime group in the production of amine initiator radicals. This comparative study was carried out in our laboratory using differential scanning photo-calorimetry and holography. The results of the new photosensitive recording materials for holography indicate that this system can be used for the formulation of very promising photopolymers that have a better performance. The aim of this study was to change the crosslinking monomer in order to increase the energetic sensitivity and discover the rest of the behavior. The new photo-polymerizable mixture contains PentaErythritol TriAcrylate (PETA) in a 1:1 ratio of volume and a 2-Hydroxy-Ethylene MethAcrylate monomer (HEMA). A diffraction efficiency of 80% is achieved with an energetic sensitivity of 3 J/cm² at 514 nm, and the spatial resolution is up to 2000 lines/mm.Part of this paper was presented at the IS&T/SPIE Symposium in Electronic Imaging, Science and Technology (Holographic Materials), February 5–10, San Jose, CA, USA