New Use for a Compound as a Matrix in the Specific Detection, Identification and/or Quantification of Alkaloids by MALDI-TOF Mass Spectrometry

The present invention relates to (i) a method of analysing small molecules that may have a mass of < 800 Da, in particular alkaloids, said method being generally referred to as MALDI-TOF-MS (or MALDI Time-of-Flight MAss Spectrometry) which is an acronym for a method of analysis by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry, to (ii) a molecule according to formula (I) and to the use thereof as a matrix in such an analysis method

Matrix for specific detection of alkaloids by MALDI-​TOF mass spectrometry

The présent invention relates to a novel bithiophenic matrix for spécifie détection of alkaloids by MALDI-TOF mass spectrometr

Effects of structural factors on the pi-dimerization and/or disproportionation of the cation radical of extended TTF containing thiophene-based pi-conjugated spacers.

The electrochemical and chemical oxidation of extended TTF 4 and 5 are analysed by cyclic voltammetry, Visible/NIR and ESR spectroscopies, and the X-ray structures of the new salts 5·BF4(CH2Cl2) and 4·ClO4(THF)1/2 are presented. The effects of structural factors on the π-dimerization or the disproportionation reaction of the cation radical are shown. The oxidation of compound 4 presents the successive formation of stable cation radical and dication species both in dichloromethane (DCM) and in a CH3CN/THF mixture. In contrast, for compound 5, the stability of the oxidation states strongly depends on the nature of the solvent. In DCM, the oxidation of 5 proceeds by two close one-electron transfers while in CH3CN/THF the dication is directly formed via a two-electron process. The X-ray structures of the two salts reveal the formation of pi-dimers of cation radical. While the dimer (5(2))2+ is due mainly to π–π interactions between the conjugating spacer, the multiplication of the sulfur atoms in compound 4 contributes to stabilize the dimer by the combined effects of S–S and π–π interactions. Visible/NIR and ESR experiments confirm the higher tendency of 4+· to dimerize with the occurrence of dimer and monomer in solution, while for 5+· only the monomer is detected in DCM. On the other hand, by dissolution of 5·BF4(CH2Cl2) in CH3CN, only the neutral and the dicationic states of compounds 5 are observed owing to the disproportionation reaction

On making nD images well-composed by a self-dual local interpolation

International audienceNatural and synthetic discrete images are generally not well-composed, leading to many topological issues: connectivities in binary images are not equivalent, the Jordan Separation theorem is not true anymore, and so on. Conversely, making images well-composed solves those problems and then gives access to many powerful tools already known in mathematical morphology as the Tree of Shapes which is of our principal interest. In this paper, we present two main results: a characterization of 3D well-composed gray-valued images; and a counter-example showing that no local self-dual interpolation satisfying a classical set of properties makes well-composed images with one subdivision in 3D, as soon as we choose the mean operator to interpolate in 1D. Then, we briefly discuss various constraints that could be interesting to change to make the problem solvable in nD

Free and immobilized matrix molecules: impairing ionization by quenching secondary ion formation in laser desorption MS

Within the last 25 years, matrix-assisted laser desorption ionization (MALDI) has become a powerful analytical tool in mass spectrometry (MS). While the method has been successfully applied to characterize large organic molecules such as proteins, sugars and polymers, its utilization for small molecules (≤ 600 Da) is significantly impaired by the coformation of matrix ions. Reducing or eliminating matrix-related signals has been subject of many studies. Some of which propose the enhancement of so-called matrix suppression effects, while others suggest the replacement of matrix molecules by materials such as microporous silicon. Alternatively, the immobilization of matrix molecules by utilizing them as self-assembled monolayers (SAMs) has been discussed. In continuation of this research, the current manuscript focuses on the elucidation of ion formation processes occurring on the surface of light absorbing SAMs. Ion yields obtained by free and immobilized matrix molecules as well as those generated by matrix-free gold film-assisted laser desorption ionization (GF-LDI) were compared. Experiments showed that the formation of strong analyte signals essentially required the presence of free matrix molecules, while the immobilization of the latter severely impaired ionization. The observed effect inversely correlated with the surface coverage of SAMs determined by cyclic voltammetry (CV). Based on these findings, the MS signal generated on light absorbing SAMs could be used supplementary to CV for determining the surface coverage of light absorbing SAMs

Applying the theory of planned behavior to examine adjuvant endocrine therapy adherence intentions

Objective:Adherence to adjuvant endocrine therapy (AET) in breast cancersurvivors is suboptimal. Using the theory of planned behavior (TPB), this study aimedto identify the strongest predictors from theTPB of AET intentions and past behaviorand assessed whether ambivalence and anticipatory emotions increased thepredictive capacity of TPB.Methods:Two hundred eighty women diagnosed with hormone positive (HR+)breast cancer who filled at least one prescription of AET responded to a surveymeasuring TPB constructs, attitudinal ambivalence, and anticipatory emotions. Theoutcomes were intentions to adhere to AET and past medication adherence (previous2 weeks).Results:TheTPB explained 66% of intentions to adhere to AET (P< 0.001). Ambiva-lence did not improve theTPB model's predictive value. When emotions were includedwithTPB, the model explained 70% of adherence intentionsF11,226= 52.84,P< 0.001(R2c= .70). This increase of 4% in predictability was statistically significant (ΔR2= 0.04),F6, 226= 7.90,P< 0.001. Women who self‐reported nonadherence in the past 2 weeksdiffered significantly in theTPB variables, ambivalence, and anticipatory emotions fromadherent women. Nonadherent participants reported lower‐future intentions toadhereF1, 236= 5.63,P= 0.018.Conclusions:Results suggest key concepts, such as anticipatory positive emotionsthat should be addressed in future interventions to enhance AET adherenceand survivorshipNational Center for Advancing Translational Sciences (KL2TR001432) National Cancer Institute (R01CA154848

A quasi-linear algorithm to compute the tree of shapes of n-D images

International audienceTo compute the morphological self-dual representation of images, namely the tree of shapes, the state-of-the-art algorithms do not have a satisfactory time complexity. Furthermore the proposed algorithms are only effective for 2D images and they are far from being simple to implement. That is really penalizing since a self-dual representation of images is a structure that gives rise to many powerful operators and applications, and that could be very useful for 3D images. In this paper we propose a simple-to-write algorithm to compute the tree of shapes; it works for \nD images and has a quasi-linear complexity when data quantization is low, typically 12~bits or less. To get that result, this paper introduces a novel representation of images that has some amazing properties of continuity, while remaining discrete

Short-term foetal immobility temporally and progressively affects chick spinal curvature and anatomy and rib development

Congenital spine deformities may be influenced by movements in utero, but the effects of foetal immobility on spine and rib development remain unclear. The purpose of the present study was to determine (1) critical time-periods when rigid paralysis caused the most severe disruption in spine and rib development and (2) how the effects of an early, short-term immobilisation were propagated to the different features of spine and rib development. Chick embryos were immobilised once per single embryonic day (E) between E3 and E6 and harvested at E9. To assess the ontogenetic effects following single-day immobilisation, other embryos were immobilised at E4 and harvested daily between E5 and E9. Spinal curvature, vertebral shape and segmentation and rib development were analysed by optical projection tomography and histology. The results demonstrated that periods critical for movement varied for different aspects of spine and rib development. Single-day immobilisation at E3 or E4 resulted in the most pronounced spinal curvature abnormalities, multiple wedged vertebrae and segmentation defects, while single-day immobilisation at E5 led to the most severe rib abnormalities. Assessment of ontogenetic effects following single-day immobilisation at E4 revealed that vertebral segmentation defects were subsequent to earlier vertebral body shape and spinal curvature abnormalities, while rib formation (although delayed) was independent from thoracic vertebral shape or curvature changes. A day-long immobilisation in chicks severely affected spine and rib development, highlighting the importance of abnormal foetal movements at specific time-points and motivating targeted prenatal monitoring for early diagnosis of congenital scoliosis