pKa tuning in quadrupolar-type two-photon ratiometric fluorescent membrane probes

International audienceTwo bolaamphiphilic quadrupoles built from a fluorene core conjugated with azine endgroups were designed and successfully used to stain GUV membranes. Their quadrupolar character induces both a shift of the pKa values close to the physiological pH and large two-photon absorption responses (i.e. over 1000 GM for acidic forms). As such they hold promise as ratiometric two-photon pH probes for monitoring slight variations of pH near cell membranes using two-photon excitation in the NIR regio

Influence of the synthetic method on the properties of two-photon-sensitive mesoporous organosilica nanoparticles

International audienceHerein we report the modulation of the properties of mesoporous silica nanoparticles (NPs) via various synthetic approaches. Three types of elaborations were compared, one in aqueous media at 25 °C, and the other two at 80 °C in water or in a water–ethanol mixture. For all these methods, an alkoxysilylated two-photon photosensitizer (2PS) was co-condensed with tetraethylorthosilicate (TEOS) in the presence of cetyltrimethylammonium bromide (CTAB), leading to five two-photon-sensitive mesoporous silica (M2PS) NPs. The M2PS NP porous structure could be tuned from radial to worm-like and MCM-41 types of organization. Besides, the 2PS precursor spatial dispersion was found to be highly dependent on both the 2PS initial concentration and the elaboration process. As a result, two-photon properties were modulated by the choice of the synthesis, the best results being found in aqueous media at 25 or 80 °C. Finally, the M2PS NPs were used for in vitro two-photon imaging of cancer cells

Paroxysmal Exercise-induced Dyskinesias Caused by GLUT1 Deficiency Syndrome

Background: Glucose transporter type 1 deficiency syndrome is due to de novo mutations in the SLC2A1 gene encoding the glucose transporter type 1. Phenomenology Shown: Paroxysmal motor manifestations induced by exercise or fasting may be the main manifestations of glucose transporter type 1 deficiency syndrome. Educational Value: Proper identification of the paroxysmal events and early diagnosis is important since the disease is potentially treatable

Letter Ruling 99-1: Electronic Retailers

The synthesis and characterization of a set of redox-active iron and ruthenium alkynyl complexes of general formula [[M]­Cl_{(1–<i>p</i>)}{CCC₆H_5–<i>m</i>(CCFlu)_<i>m</i>}_(1+<i>p</i>)]­[PF₆]_<i>n</i> are reported (<i>n</i> = 0–1; <i>m</i> = 1–2; [M] = [Fe­(η⁵-C₅Me₅)­(κ²-dppe)] and <i>p</i> = 1 or [M] = [<i>trans</i>-Ru­(κ²-dppe)₂] and <i>p</i> = 0–1). The linear and third-order nonlinear optical properties of these new organometallic complexes featuring phenylalkynyl ligands functionalized by 2-fluorenyl (Flu) groups were studied in their stable redox states. Their first electronic transitions are assigned with the help of DFT calculations. We show here that these compounds possess significant third-order NLO responses in the near-IR range for molecules of their size. In particular, the remarkably large 2PA activities of the new Ru­(II) compounds in the 600–800 nm range (<i>Z</i>-scan) make them attractive nonlinear chromophores. Structure–property studies emphasize the importance of para- versus meta-connection of the 2-fluorenylethynyl units on the phenylalkynyl core and reveal that upon progressing from mono- to bis-alkynyl complexes a further increase of the 2PA cross section can be obtained while maintaining linear transparency in the visible range

Progressive Ataxia and Palatal Tremor: Think about POLG Mutations

Background: Progressive ataxia and palatal tremor (PAPT) can be observed in both acquired brainstem or cerebellar lesions and genetic disorders. Phenomenology shown: PAPT due to mutation in POLG, the gene encoding the mitochondrial DNA polymerase. Educational value: POLG mutation should be considered in patients with PAPT, particularly when additional clues such as a sensory neuronopathy or an ophthalmoplegia are present

Nonlinear optical properties of meso-Tetra(fluorenyl)porphyrins peripherally functionalized with one to four ruthenium alkynyl substituents

The synthesis of a series of four porphyrin derivatives based on a meso-tetrafluorenylporphyrin core functionalized with one to four trans-chlorobis(dppe)ruthenium alkynyl units (dppe = 1,2-bis(diphenylphosphino)ethane) at the periphery, together with cyclic voltammetry (CV) and UV–Vis absorption and emission spectroscopy studies, are reported. In these multipolar assemblies, the organoruthenium endgroups are potential electron-donors and the central porphyrin core is a potential electron-acceptor. The third-order nonlinear optical (NLO) responses have been assessed by Z-scan, revealing that these extended π-networks incorporating polarizable organometallic units behave as nonlinear absorbers in the near-IR range. The role of the peripheral transition metal centers on the third-order NLO properties is discussed

Linear and Third-Order Nonlinear Optical Properties of Fe(n5-C5Me5)(k2-dppe)- and trans-Ru(k2-dppe)2-Alkynyl Complexes Containing 2-Fluorenyl End Groups

The synthesis and characterization of a set of redox-active iron and ruthenium alkynyl complexes of general formula [[M]Cl(1–p){C≡CC6H5–m(C≡CFlu)m}(1+p)][PF6]n are reported (n = 0–1; m = 1–2; [M] = [Fe(η5-C5Me5)(κ2-dppe)] and p = 1 or [M] = [trans-Ru(κ2-dppe)2] and p = 0–1). The linear and third-order nonlinear optical properties of these new organometallic complexes featuring phenylalkynyl ligands functionalized by 2-fluorenyl (Flu) groups were studied in their stable redox states. Their first electronic transitions are assigned with the help of DFT calculations. We show here that these compounds possess significant third-order NLO responses in the near-IR range for molecules of their size. In particular, the remarkably large 2PA activities of the new Ru(II) compounds in the 600–800 nm range (Z-scan) make them attractive nonlinear chromophores. Structure–property studies emphasize the importance of para- versus meta-connection of the 2-fluorenylethynyl units on the phenylalkynyl core and reveal that upon progressing from mono- to bis-alkynyl complexes a further increase of the 2PA cross section can be obtained while maintaining linear transparency in the visible range

Nucleus accumbens deep brain stimulation in adult patients suffering from severe and enduring anorexia nervosa (STIMARS): protocol for a pilot study

BackgroundAffecting adolescent and young adults, anorexia nervosa (AN) has the highest death rate of all mental disorders. Effective treatment options are lacking and a significant proportion of patients develop severe and chronic forms of the disease with long-lasting functional impairment. Neurobiology of AN implicates the nucleus accumbens as a core structure of the ventral striatum highly connected to the prefrontal cortex, the insula and the limbic system. Several studies reported promising results of deep brain stimulation for treatment-resistant AN. The aim of this study was to investigate the safety and efficacy of bilateral nucleus accumbens deep brain stimulation in severe and enduring AN.Methods and analysisThis is a prospective, multicentre, single-arm, open-label, non-randomized pilot trial of bilateral nucleus accumbens deep brain stimulation for severe and enduring AN. Patients will be followed up for 24 months after deep brain stimulation. The main objective of this study is to measure the safety and feasibility of nucleus accumbens deep brain stimulation in this population. The recruitment rate will be collected prospectively. Potential deep brain stimulation efficacy will be monitored by changes in: 1) health-related quality of life; 2) weight; 3) eating disorder symptomatology; 4) neuropsychological changes of cognitive flexibility, habits formation, emotional processing and central coherence; 5) psychiatric comorbidities (anxiety, depression, obsession). Local field potential recordings during an exposure task will be proposed to the patients. Additionally, caregiver quality of life will be assessed.DiscussionWe present the design and rationale for a pilot study investigating the safety of nucleus accumbens deep brain stimulation for treatment resistant anorexia nervosa. This trial will provide an estimated effect size of nucleus accumbens deep brain stimulation for treatment-resistant anorexia nervosa to support future larger-scale clinical trials

Le Valanginien du Mont-Rose de la Madrague (massif de Marseilleveyre, Bouches-du-Rhone)

Abstract A report on the stratigraphy, foraminifers (by Marie), and mollusks (by Mongin) of the Valanginian (Cretaceous) deposits of Mont-Rose de la Madrague in the Marseilleveyre massif, Bouches-du-Rhone, France. The so-called lower white limestone, formerly included in the upper Jurassic, represents beds belonging to the Infravalanginian.</jats:p