X-ray diffraction study of a three-component lamellar phase

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 1995.Includes bibliographical references (p. 140-142).by Reiko Oda.Ph.D

Dynamics of ion-regulated photoinduced electron transfer in BODIPY-BAPTA conjugates

International audienceEfficient Ca2+-switched fluorescent sensors, where fluorescence output is governed by a light-activated ion-gated electron transfer pathway, can be obtained on combining BODIPY chromophores with a readily oxidized biocompatible and selective BAPTA receptor. Herein we report the synthesis and studies of two such conjugates, which vary in the nature of the spacer separating the two electroactive components, namely none (1) or phenyl (2). Single crystal X-ray crystallography and molecular modelling structures and calculations give information on molecular and electronic structure, while steady-state fluorescence experiments show high Ca2+-induced fluorescence enhancement factors of 122 and 23 and Kd values of 0.50 μM and 0.13 μM for 1 and 2, respectively. Notably, studies of the ultrafast photoinduced processes (through transient absorption spectroscopy) give access to electron transfer dynamics in pseudophysiological media as well as in a polar non-protic solvent and information about the fate of the excited molecules in the presence and absence of calcium. In water, electron transfer rates as high as 3.3 × 1012 s−1 and 8.3 × 1011 s−1 are measured for the ion-free, directly connected conjugate and the variant incorporating a phenyl spacer, respectively. This electron transfer pathway is efficiently blocked by the presence of an ion, restoring fluorescence

Social communication impairments and restricted, repetitive patterns ("Kodawari") considered from the "Comprehension" section of the WISC-IV in autism spectrum disorder

Background: Many studies have used the Wechsler Intelligence Scale (WISC) to examine the characteristics of autism spectrum disorder (ASD). However, most studies have been based on profile analysis, not on content analysis. Objective: The objective of the present study was to apply the WISC-IV to clinical assessment of ASD and clarify how the characteristics of the disorder were reflected in specific items. Methods: The study participants were 20 patients aged 5-16 years diagnosed with ASD according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). We recruited 20 patients with attention-deficit/hyperactivity disorder (ADHD) and 20 patients with other disorders (neurotic disorders) as controls. We then compared the scores of the ninth item of the WISC-IV ("Comprehension") among the three groups. Results: The differences observed between the ASD vs. the other disorders group were not significant by the standard scoring method. Thus, a two-level scoring method of 0 and ≥1 point was adopted. As a result, significantly more participants in the ASD group scored 0 points compared with the ADHD and other disorders grou

Common mechanism for helical nanotube formation by anodic polymerization and by cathodic deposition using helical pores on silicon electrodes

We report that platinum-assisted chemical etching formed self-organized helical pores in silicon substrates can be utilized as platforms for the electrochemical production of nanohelices of conducting polymers (polypyrrole) and metals (gold). Surprisingly, the nanohelices thus created are tubes although the polymerization and deposition were carried out by anodic and cathodic reactions, respectively. Based on our results, we propose a common mechanism for the formation of tubular nanohelices by both anodic polymerization and cathodic deposition through the accumulation of reactants in microporous silicon which covers the wall surface of the helical pores

Dynamics of proteins with different molecular structures under solution condition

Incoherent quasielastic neutron scattering (iQENS) is a fascinating technique for investigating the internal dynamics of protein. However, low flux of neutron beam, low signal to noise ratio of QENS spectrometers and unavailability of well-established analyzing method have been obstacles for studying internal dynamics under physiological condition (in solution). The recent progress of neutron source and spectrometer provide the fine iQENS profile with high statistics and as well the progress of computational technique enable us to quantitatively reveal the internal dynamic from the obtained iQENS profile. The internal dynamics of two proteins, globular domain protein (GDP) and intrinsically disordered protein (IDP) in solution, were measured with the state-of-the art QENS spectrometer and then revealed with the newly developed analyzing method. It was clarified that the average relaxation rate of IDP was larger than that of GDP and the fraction of mobile H atoms of IDP was also much higher than that of GDP. Combined with the structural analysis and the calculation of solvent accessible surface area of amino acid residue, it was concluded that the internal dynamics were related to the highly solvent exposed amino acid residues depending upon protein’s structure

Slow kinetic evolution of nanohelices based on gemini surfactant self-assemblies with various enantiomeric excess

Very slow kinetic evolution (days) of chiral nanoribbons based on amphiphilic molecular assemblies is investigated for various enantiomeric excess. In the early stage of ribbon formation, those formed for low enantiomeric excess (0 <= ee <= 0.5) show chiral segregation, and are made with a mixture of short-pitched right-handed and left-handed twisted ribbons. With time, these nano-ribbons merge to form ribbons with larger pitch and single-handedness, which is determined by the majority enantiomer.Initiative d'excellence de l'Université de Bordeau

Chem. Commun.

Hybrid nanometric helical structures formed by the molecular assemblies of dicationic gemini surfactants with tartrate counterions covered with helical silica walls interact differently with matching or mismatching enantiomers of the tartrate. The difference of the interaction is based on the cooperativity between the chiral crystalline gemini surfactant molecular organization/conformation and the rigid chiral nanospace formed by the helical silica wall

Inactivation of the Influenza Virus by a Supplemental Fermented Plant Product (Manda Koso)

Manda Koso is a commercial fermented plant product (FPP) made from 53 types of fruits and vegetables that are fermented for more than 3 years. We hypothesized that the FPP can prevent infection by influenza virus and human norovirus. Therefore, we investigated the effects of the FPP on influenza virus and feline calicivirus, a surrogate of human norovirus. We found that 10% FPP inactivated the influenza virus but not the feline calicivirus. Inhibition of the influenza virus was highly concentration-dependent: 1% and 0.3% FPP showed reduced inactivation efficacy. The effects of the FPP on the influenza virus-infected cells were investigated by addition of the FPP to the culture medium after virus infection. No suppressive effect of the FPP on influenza replication in MDCK cells was observed. The results showed that the FPP could inactivate influenza virus by affecting the virus particles

Successful Treatment of Metastatic Urothelial Carcinoma after Accurate Diagnosis by Immunohistochemistry

Urothelial carcinoma usually presents with hematuria, but cases of multiple lymphadenopathy with elevated S-pancreas-1 antigen (SPan-1) levels have not been reported. A 62-year-old Japanese man with lymphadenopathies was diagnosed with an adenocarcinoma of unknown origin and transferred to our hospital for further diagnosis. Serum carbohydrate antigen 19-9 and SPan-1 levels were extremely elevated. Uroplakin III immunostaining was positive in the inguinal lymph node, and cystoscopy revealed the presence of invasive urothelial carcinoma. Treatment with cisplatin and gemcitabine promoted a complete metabolic response for > 4 years. The detection of uroplakin III and serum SPan-1 might help diagnose urothelial carcinoma