Jose Navarrete v. USA

USDC for the District of New Jerse

Comparison of the Methods for the Background Reduction of Thick Targets in Routine PIXE Analysis

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Impact of the Intermolecular Interactions on the Electronic and Charge-Transport Properties of Organic Materials: A Joint Experimental and Theoretical Approach

The use of organic materials to design electronic devices has actually presented a broad interest because they constitute an ecological and suitable resource for our current "electronic world". These materials provide several advantages (low cost, light weight, good flexibility and solubility to be easily printed) that cannot be afforded with silicon.[1] They can also potentially interact with biological systems, something impossible with inorganic devices. The performance of the organic-based electronic devices critically depends not only to the intrinsic properties of the conjugated cores but also to the supramolecular arrangement.[2] In this contribution, we present some of our more recent investigations on this field dealing with the better understanding of the complex structure-properties relationships of organic nanomaterials.[3] For this purpose, we use a joint experimental and theoretical approach that includes spectroscopic measurements and molecular modeling.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Formation of stimuli-responsive cyclophanes by self-assembly: the case of carbazole-based biradicals

Dynamic covalent bonds has recently received lot of attention because of their unique feature to become reversible under mild conditions.[1] In this context, π-conjugated biradical compounds has emerged as essential building blocks.[2] For instance, we have demonstrated that 2,7-dicyanomethylene-9-(2-ethylhexyl)carbazole biradical reversibly converts to a macrocycle cyclophane upon soft stimuli (temperature, pressure, light), showing strong chromic effects.[3] We now extent this study towards longer conjugated carbazole backbone (i.e., indolocarbazole shown in Figure 1), aiming at investigating how the elongation of the conjugated backbone impacts on the formation of stimuli-responsive cyclophanes. The self-assembly process is investigated both in solution and solid state by linking theory and experiments.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Multiresponsive chromic soft materials: formation of macrocycles from carbazole-based biradicaloids

-conjugated biradical compounds become essential building blocks in DCC (dynamic covalent chemistry).1 This field is based on the creation of structural scaffolds based on chemical components which interact through strong but reversible bonds. Importantly, dynamic covalent bonds will be at the center of attention because of their unique feature to become reversible under mild conditions.2 Recently, we have demonstrated the reversible interconversion between a stable quinoid precursor based on a para-substituted carbazole with terminal dicyanomethylene groups and a macrocycle cyclophane upon soft external stimuli (temperature, pressure, light), which results on strong chromic features.3 In this work, we investigate the interconversion of the monomer/cyclophane transformation in carbazole-based systems, both in solution and solid state, upon external stimuli. To this end, we use a combined experimental and theoretical study that links vibrational spectroscopy (Raman and IR) with DFT calculations.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Carbazole-based biradicaloids as potential building blocks for dynamic covalent chemistry

Pi-conjugated biradical compounds become essential building blocks in DCC (dynamic covalent chemistry).1 This field is based on the creation of structural scaffolds based on chemical components which interact through strong but reversible bonds. Importantly, dynamic covalent bonds will be at the center of attention because of their unique feature to become reversible under mild conditions.2 Recently, we have demonstrated the reversible interconversion between a stable quinoid precursor based on a para-substituted carbazole with terminal dicyanomethylene groups and a macrocycle cyclophane upon soft external stimuli (temperature, pressure, light), which results on strong chromic features.3 In this work, we investigate the impact of the substitution pattern (i.e., the insertion of dicyanomethylene groups at the 2,7 (para) or 3,6 (meta) positions or the elongation of the carbazole backbone) on the formation of stimuli-responsive cyclophanes by self-assembly. To this end, we use a combined experimental and theoretical study that links vibrational spectroscopy (Raman and IR) with DFT calculations.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Multiresponsive chromic soft materials: formation of strongly coupled σ-dimers from IndoloCarbazole-based biradicaloids

Dynamic covalent chemistry is focused on the creation of structural scaffolds based on chemical components that interact through strong but reversible bonds. In fact, dynamic covalent bonds receive lot of attention because of their unique feature to become reversible under mild conditions.1 π-conjugated biradical compounds has emerged as essential building blocks in DCC (dynamic covalent chemistry).2 We have recently demonstrated the potential of a para-substituted carbazole with terminal dicyanomethylene groups to act as building blocks in DCC.3 In fact, this quinoid carbazole monomer transform to a macrocycle cyclophane upon soft external stimuli (temperature, pressure, light), showing strong chromic features. Here, we explore the effect of the elongation of the carbazole backbone on the formation of stimuli-responsive cyclophanes by self-assembly. To this end, we use a join experimental and theoretical approach that links vibrational spectroscopy (Raman and IR) with DFT calculationsUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Impact of the dicyanomethylene substitution position on the cyclophane macrocycle formation in carbazole-based biradicals

π-Conjugated biradical compounds, featuring unique unsaturated valences and radical centers in the ground state, are fundamentally important for understanding the nature of chemical bonds and have potential applications in material science. [1] Recently, it has been demonstrated that several -conjugated mono- and biradicals systems form long strain -bonds between two unpaired electrons resulting in macrocyclic or staircase oligomers or polymers by self-assembly processes. [2] Therefore, these materials are potential building blocks for dynamic covalent chemistry (DCC) since the aggregates can be formed or broken upon soft external stimuli. For instance, 2,7-dicyanomethylene-9-(2-ethylhexyl)carbazole biradical (p-Cz-alkyl in Figure 1) reversibly converts upon soft stimuli (temperature, pressure, light) to a cyclophane tetramer as a result from the formation (or bond cleavage) of long C-C single bonds.[3] Here, we present an experimental and theoretical study in order to investigate how the N-substitution and the change from para- to meta-dicyanomethylene substitution on carbazole-based biradicals affects their biradical character and thus, their tendency to act as useful motifs for DCC (see Figure 1).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Impaired Intracellular Transport and Cell Surface Expression of Nonpolymorphic HLA-E

The assembly of the classical, polymorphic major histocompatibility complex class I molecules in the endoplasmic reticulum requires the presence of peptide ligands and ~2-microglobulin (~2m). Formation of this trimolecular complex is a prerequisite for e~cient transport to the cell surface, where presented peptides are scanned by T lymphocytes. The function of the other class I molecules is in dispute. The human, nonclassical class I gene, HLA-E, was found to be ubiquitously transcribed, whereas cell surface expression was dif~cult to detect upon transfection. Pulse chase experiments revealed that the HLA-E heavy chain in transfectants, obtained with the murine myeloma cell line P3X63-Ag8.653 (X63), displays a significant reduction in oligosaccharide maturation and intracellular transport compared with HLA-B27 in corresponding transfectants. The accordingly low HLA-E cell surface expression could be significantly enhanced by either reducing the culture temperature or by supplementing the medium with human ~2m, suggesting inefficient binding of endogenous peptides to HLA-E. To analyze whether HLA-E binds peptides and to identify the corresponding ligands, fractions of acid-extracted material from HLA-E/X63 transfectants were separated by reverse phase HPLC and were tested for their ability to enhance HLA-E cell surface expression. Two fractions specifically increased the HLA class I expression on the HLA-E transfectant clone