39 research outputs found

    Combining scanning probe microscopy and x-ray spectroscopy

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    A new versatile tool, combining Shear Force Microscopy and X-Ray Spectroscopy was designed and constructed to obtain simultaneously surface topography and chemical mapping. Using a sharp optical fiber as microscope probe, it is possible to collect locally the visible luminescence of the sample. Results of tests on ZnO and on ZnWO4 thin layers are in perfect agreement with that obtained with other conventional techniques. Twin images obtained by simultaneous acquisition in near field of surface topography and of local visible light emitted by the sample under X-Ray irradiation in synchrotron environment are shown. Replacing the optical fibre by an X-ray capillary, it is possible to collect local X-ray fluorescence of the sample. Preliminary results on Co-Ti sample analysis are presented

    Gelatin-based microspheres crosslinked with glutaraldehyde and rutin oriented to cosmetics

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    ABSTRACT Glutaraldehyde (GTA) has been extensively used as a gelatin crosslinking agent, however, new natural ones have been suggested as more biocompatible. Polyphenols are possible candidates and the flavonols, such as rutin (RUT), also exhibit potential synergism with sunscreens and antioxidant agents used in cosmetics. In this work, gelatin microspheres (M0) were obtained and crosslinked with GTA 10 mM (MG) or RUT 10 mM (MR), dissolved in acetone:NaOH 0,01M (70:30 v/v). MG exhibited crosslinking extent of 54.4%. Gelatin, M0, MG and MR did not elicit any signs of skin damage, regarding the formation of erythema, the barrier function disruption and negative interference in the stratum corneum hydration. Oily dispersions containing M0, MG or MR, isolated or combined with benzophenone-3 or octyl methoxycinnamate, suggested that the microspheres, at a 5.0% w/w, had no additional chemical or physical photoprotective effect in vitro. Crosslinking with RUT had occurred, but in a lower degree than GTA. Microspheres had not improved sun protection parameters, although, non-treated gelatin interfered positively with the SPF for both UV filters. The in vivo studies demonstrated that these materials had very good skin compatibility

    New perspectives in Autism spectrum disorder associated with tuberous sclerosis

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    Recent advances inmolecular genetics and preclinical studies of tuberous sclerosis complex (TSC) have helped to better understand the pathophysiology of TSC-related autism spectrum disorder (ASD). Furthermore, developmental studies have shown that infants with TSC begin to diverge from the neurotypical trajectories at the age of 6 months. Early abnormalities are often characterized by a delay in nonverbal cognitive skills, such as fine motor and visual reception domains followed by qualitative impairment of social communication. The expanding possibilities of an early diagnosis of TSC should increasingly allow the prompt identification of a population of infants at high risk for developing ASD. A presymptomatic diagnosis of TSC could facilitate not only the prospective investigation of developmental trajectories and early markers of ASD but also the evaluation of the efficacy of early interventions. Early identification of infants at high-risk for ASD, such as TSC infants, can allow designing individualized treatment strategies to address deficits in specific developmental domains associated with autism. The involvement of mammalian target of rapamycin (mTOR) in determining the behavioral phenotypes associated with TSC led to the hypothesis that mTOR inhibitors could also have a benefit on ASD symptoms. After the promising results from preclinical studies administrating rapamycin, clinical trials studying mTOR inhibitors are now undergoing

    RNA complementary to the 5'UTR of mRNA triggers effective silencing in Saccharomyces cerevisiae

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    Conditional silencing of target genes in Saccharomyces cerevisiae by antisense RNAs expressed in vivo has been challenged. The MFa1::lacZ fusion present in S. cerevisiae SF51-3 was chosen as a model target, and fragments of this gene were cloned in reverse orientation into the expression vector pYES2, bearing the GAL1 promoter. Among the different antisense constructs tested, only the one complementary to the 5’ UTR of target mRNA featured effective silencing. Nevertheless, the expression in vivo of this antisense RNA could not be properly tuned by the absence or presence of galactose in the culture medium. Accordingly, conditional silencing could not be attained by this antisense hosted into pYES2. On the contrary, cloning the same antisense construct into the expression vector pSAL4 yielded a fully conditional silencing linked to the control of antisense expression by the absence or presence of Cu2+ into the culture medium
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