795 research outputs found
Preparation, structural characterisation and antibacterial properties of Ga-doped sol-gel phosphate-based glass
A sol-gel preparation of Ga-doped phosphate-based glass with potential application in antimicrobial devices has been developed. Samples of composition (CaO)(0.30)(Na2O)(0.20-x) (Ga2O3) (x) (P2O5)(0.50) where x = 0 and 0.03 were prepared, and the structure and properties of the gallium-doped sample compared with those of the sample containing no gallium. Analysis of the P-31 MAS NMR data demonstrated that addition of gallium to the sol-gel reaction increases the connectivity of the phosphate network at the expense of hydroxyl groups. This premise is supported by the results of the elemental analysis, which showed that the gallium-free sample contains significantly more hydrogen and by FTIR spectroscopy, which revealed a higher concentration of -OH groups in that sample. Ga K-edge extended X-ray absorption fine structure and X-ray absorption near-edge structure data revealed that the gallium ions are coordinated by six oxygen atoms. In agreement with the X-ray absorption data, the high-energy XRD results also suggest that the Ga3+ ions are octahedrally coordinated with respect to oxygen. Antimicrobial studies demonstrated that the sample containing Ga3+ ions had significant activity against Staphylococcus aureus compared to the control
2012 update of French guidelines for the pharmacological treatment of postmenopausal osteoporosis
OBJECTIVES: To update the evidence-based position statement published by the French National Authority for Health (HAS) in 2006 regarding the pharmacological treatment of postmenopausal osteoporosis, under the auspices of the French Society for Rheumatology and Groupe de Recherche et d\u27Information sur les Ostéoporoses (GRIO), and with the participation of several learned societies (Collège National des Gynécologues et Obstétriciens Français, Groupe d\u27Étude de la Ménopause et du Vieillissement hormonal, Société Française de Chirurgie Orthopédique, Société Française d\u27Endocrinologie, and Société Française de Gériatrie et de Gérontologie).
METHODS: A multidisciplinary panel representing the spectrum of clinical specialties involved in managing patients with postmenopausal osteoporosis developed updated recommendations based on a systematic literature review conducted according to the method advocated by the HAS.
RESULTS: The updated recommendations underline the need for osteoporosis pharmacotherapy in women with a history of severe osteoporotic fracture. In these patients, any osteoporosis medication can be used; however, zoledronic acid is the preferred first-line medication after a hip fracture. In patients with non-severe fractures or no fractures, the appropriateness of osteoporosis pharmacotherapy depends on the bone mineral density and FRAX(®) values; any osteoporosis medication can be used, but raloxifene and ibandronate should be reserved for patients at low risk for peripheral fractures. Initially, osteoporosis pharmacotherapy should be prescribed for 5 years. The results of the evaluation done at the end of the 5-year period determine whether further treatment is in order.
CONCLUSIONS: These updated recommendations are intended to provide clinicians with clarifications about the pharmacological treatment of osteoporosis
Core/clad phosphate glass fibres containing iron and/or titanium
Phosphate glasses are novel amorphous biomaterials due to their fully resorbable characteristics, with controllable degradation profiles. In this study, phosphate glasses containing titanium and/or iron were identified to exhibit sufficiently matched thermal properties (glass transition temperature, thermal expansion coefficient and viscosity) which enabled successful co-extrusion of glass billets to form a core/clad preform. The cladding composition for the core/clad preforms were also reversed. Fe clad and Ti clad fibres were successfully drawn with an average diameter of between 30~50 μm. The average cladding annular thickness was estimated to be less than 2 μm. Annealed core/clad fibres were degraded in PBS for a period of 27 days. The strength of the Fe clad fibres appeared to increase from 303 ± 73 MPa to 386 ± 45 MPa after nearly 2 weeks in the dissolution medium (phosphate buffered solution) before decreasing by day 27. The strength of the Ti clad fibres revealed an increase from 236 ± 53 MPa to 295 ± 61 MPa when compared at week 3. The tensile modulus measured for both core/clad fibres ranged between 51 GPa to 60 GPa. During the dissolution study, Fe clad fibres showed a peeling mechanism compared to the Ti clad fibres
Design and development of the ALICE common readout unit user logic firmware for the Muon Identifier readout chain
A Large Ion Collider Experiment (ALICE) at the Large Hadron Collider (LHC) at
CERN went through a major upgrade in which some of its subdetectors were
replaced with new ones, while others are equipped with new electronics. The aim
of the upgrade is to withstand higher collision rates during the third running
period (Run 3), which started in 2022. As part of the upgrade, certain
subdetectors such as the Muon Trigger, renamed to Muon Identifier, now operate
in a continuous, triggerless readout mode, in addition to the previous
triggered readout mode. Due to the increased quantity of data, typical
methodologies are impossible to employ without massive efforts to expand the
processing capacity. Since the new ALICE computing system cannot keep up with
the increased data flow of the Muon Identifier, a new processing algorithm has
been established. These proceedings provide a insight to the new approach of
processing the Muon Identifier readout data based on a customized user logic
FPGA firmware
IDST 190 Experiencing Latin America - Movie Blurb
This entails details about a scene for a movie project that was completed entirely in Spanish
One-Pot Three-Component Synthesis of Vicinal Diamines via In Situ Aminal Formation and Carboamination
A synthesis of vicinal diamines via in situ aminal formation and carboamination of allyl amines is reported. Employing highly electron-poor trifluoromethyl aldimines in their stable hemiaminal form was key to enable both a fast and complete aminal formation as well as the palladium-catalyzed carboamination step. The conditions developed allow the introduction of a wide variety of alkynyl, vinyl, aryl, and hetereoaryl groups with complete regioselectivity and high diastereoselectivity. The reaction exhibits a high functional-group tolerance. Importantly, either nitrogen atom of the imidazolidine products can be selectively deprotected, while removal of the aminal tether can be achieved in a single step under mild conditions to reveal the free diamine. We expect that this work will promote the further use of mixed aminal tethers in organic synthesis
In situ tether formation from amines and alcohols enabling highly selective Tsuji-Trost allylation and olefin functionalization
The use of tethers allows to overcome reactivity and selectivity issues often encountered with intermolecular reactions. Although tethers have been successfully applied for decades, their installation and removal usually requires additional steps. This minireview highlights the recent development of tethers that can be installed in situ on (homo)-allyl amines or alcohols for Tsuji-Trost allylation or double bond functionalization. In particular, the use of (hemi-)acetal tethers for highly regioselective and enantioselective Tsuji-Trost allylation was recently reported. Hydroamination of olefins starting from allylic amines could be achieved via a retro Cope-elimination using catalytic amount of an aldehyde for tether formation. Finally, bifunctionalizations of olefins were developed using either carbon dioxide or carbonyls/imines as tether precursors. These recent breakthroughs greatly enhanced the efficiency of the tethering approach for olefin functionalization, and will make it even more attractive for synthetic chemists in the future
Palladium-Catalyzed Vicinal Amino Alcohols Synthesis from Allyl Amines by In Situ Tether Formation and Carboetherification
Vicinal amino alcohols are important structural motifs of bioactive compounds. Reported herein is an efficient method for their synthesis based on the palladium-catalyzed oxy-alkynylation, oxy-arylation, or oxy-vinylation of allylic amines. High regio- and stereoselectivity were ensured through the in situ formation of a hemiaminal tether using the cheap commercially available trifluoroacetaldehyde in its hemiacetal form. The obtained compounds are important building blocks, which can be orthogonally deprotected to give either free alcohols, amines, or terminal alkynes
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