Polarization-Tailored Raman Frequency Conversion in Chiral Gas-Filled Hollow Core Photonic Crystal Fibers

Broadband-tunable sources of circularly-polarized light are crucial in fields such as laser science, biomedicine and spectroscopy. Conventional sources rely on nonlinear wavelength conversion and polarization control using standard optical components, and are limited by the availability of suitably transparent crystals and glasses. Although gas-filled hollow-core photonic crystal fiber provides pressure-tunable dispersion, long well-controlled optical path-lengths, and high Raman conversion efficiency, it is unable to preserve circular polarization state, typically exhibiting weak linear birefringence. Here we report a revolutionary approach based on helically-twisted hollow-core photonic crystal fiber, which displays circular birefringence, thus robustly maintaining circular polarization state against external perturbations. This makes it possible to generate pure circularly-polarized Stokes and anti-Stokes signals by rotational Raman scattering in hydrogen. The polarization state of the frequency-shifted Raman bands can be continuously varied by tuning the gas pressure in the vicinity of the gain suppression point. The results pave the way to a new generation of compact and efficient fiber-based sources of broadband light with fully-controllable polarization state.Comment: 5 pages, 4 figure

Continuous atom laser with Bose-Einstein condensates involving three-body interactions

We demonstrate, through numerical simulations, the emission of a coherent continuous matter wave of constant amplitude from a Bose-Einstein Condensate in a shallow optical dipole trap. The process is achieved by spatial control of the variations of the scattering length along the trapping axis, including elastic three body interactions due to dipole interactions. In our approach, the outcoupling mechanism are atomic interactions and thus, the trap remains unaltered. We calculate analytically the parameters for the experimental implementation of this CW atom laser.Comment: 11 pages, 4 figure

Effects of Urbanization and Other Factors on Synthetic Unit Hydrographs

Paper by Albert H. Halff, Jose I. Novoa, and Louis M. Salced

Effect of a plasma grating on pump-probe experiments near the ionization threshold in gases

Calculations are performed of the phase shift caused by the spatial modulation in the plasma density due to interference between a strong pump pulse and a weak probe pulse. It is suggested that a recent experiment [Loriot et al., Opt. Express v. 17, 13429 (2009)] observed an effective birefringence from this plasma grating rather than from the higher-order Kerr effect.Comment: 3 pages, 1 figure. Fix typos and correct number

Synthesis, molecular modelling and NLO properties of new ytterbium(iii) complexes with vildagliptin

Two nonlinear optical ytterbium(III) complexes with vildagliptin have been synthesized and their ground state geometries have been predicted by semi-empirical quantum chemistry methods: [Yb(vilda)3(acac)] and [Yb(vilda)2(acac)(bipy)], where vilda = vildagliptin, acac = acetylacetonate and bipy = 2,2'-bipyridine. ATR-Fourier transform infrared (ATR-FTIR) spectral studies have been carried out to identify the functional groups of the novel complexes. The third order nonlinear optical response has been experimentally studied using Z-scan and P-scan methods, and static and frequency dependent second hyperpolarizabilities have been theoretically investigated using the Sparkle/PM6 model. The novel materials in diluted solutions have nonlinear refractive indices comparable to that of carbon disulphide.J.A. Novoa-López would like to thank University of Vigo for its financial support under “Axudas predoutorais: Áreas de especial dificultade” PhD scholarship program. Support by Xunta de Galicia under projects K133131H64102 and K044131H64502 is gratefully acknowledged by P. Chamorro-Posada, H. Michinel and P. Martín-Ramos are grateful to Junta de Castilla y León for providing funds under project VA300A12-1

The Forel-Ule scale revisited spectrally: preparation protocol, transmission measurements and chromaticity

Within the EC-funded project CITLOPS (Citizens' Observatory for Coast and Ocean Optical Monitoring), with its main goal to empower endusers, willing to employ community-based environmental monitoring, our aim is to digitalize the colours of the Forel-Ule scale to establish the colour of natural waters through smartphone imaging. The objective of this study was to reproduce the Forel-Ule scale following the original recipes, measure the transmission of the solutions and calculate the chromaticity coordinates of the scale as Wernand and Van der Woerd did in 2010, for the future development of a smartphone application. Some difficulties were encountered when producing the scale, so a protocol for its consistent reproduction was developed and is described in this study. Recalculated chromaticity coordinates are presented and compared to measurements conducted by former scientists. An error analysis of the spectral and colourimetric information shows negligible experimental errors

Functional Interplay of Type-2 Corticotrophin Releasing Factor and Dopamine Receptors in the Basolateral Amygdala-Medial Prefrontal Cortex Circuitry

Background: Basolateral amygdala (BLA) excitatory projections to medial prefrontal cortex (PFC) play a key role controlling stress behavior, pain, and fear. Indeed, stressful events block synaptic plasticity at the BLA-PFC circuit. The stress responses involve the action of corticotrophin releasing factor (CRF) through type 1 and type 2 CRF receptors (CRF1 and CRF2). Interestingly, it has been described that dopamine receptor 1 (D1R) and CRF peptide have a modulatory role of BLA-PFC transmission. However, the participation of CRF1 and CRF2 receptors in BLA-PFC synaptic transmission still is unclear. Methods: We used in vivo microdialysis to determine dopamine and glutamate (GLU) extracellular levels in PFC after BLA stimulation. Immunofluorescence anatomical studies in rat PFC synaptosomes devoid of postsynaptic elements were performed to determine the presence of D1R and CRF2 receptors in synaptical nerve endings. Results: Here, we provide direct evidence of the opposite role that CRF receptors exert over dopamine extracellular levels in the PFC. We also show that D1R colocalizes with CRF2 receptors in PFC nerve terminals. Intra-PFC infusion of antisauvagine-30, a CRF2 receptor antagonist, increased PFC GLU extracellular levels induced by BLA activation. Interestingly, the increase in GLU release observed in the presence of antisauvagine-30 was significantly reduced by incubation with SCH23390, a D1R antagonist. Conclusion: PFC CRF2 receptor unmasks D1R effect over glutamatergic transmission of the BLA-PFC circuit. Overall, CRF2 receptor emerges as a new modulator of BLA to PFC glutamatergic transmission, thus playing a potential role in emotional disorders. Keywords: CRF2 receptor; D1 receptor; dopaminergic transmission; glutamatergic transmission; prefrontal cortex

PTHrP and SPARC expressions in human colorectal cancer: An in silico analysis

PTHrP is a paraneoplastic factor involved in the progression and theacquisition of the aggressive behavior of different types of tumors. Employing in vitroand in vivo models of colorectal cancer (CRC), our research group observed thatPTHrP promotes cell survival, proliferation, migration, angiogenesis, epithelial tomesenchymal transition (EMT) program, cancer stem cell (CSC) phenotype, andchemoresistance through different signaling pathways. Recently, in HCT116 cellsderived from CRC we found that PTHrP acts increasing SPARC protein expression, arelevant protein involved in CRC progression. Moreover, SPARC treatment on HCT116cells potentiated PTHrP effects. In vivo model, PTHrP also increased SPARC expression. Based on these findings, the aim of this work is explore the clinical relevance ofPTHrP and SPARC tumor expression in human CRC using in silico analysis.Methods: Cytoscape 3.8.2 stringApp was employed to visualize molecular networksfrom the STRING database related to CRC, and proteins associated with prognosticfactors were selected to analysis. Using STRING Enrichment App, the proteins networks (PN) merged were compared to establish enrichment. Finally, in silico tool andonline data sets (GEPIA2 and STRING 11.0) were used to explore the association ofPTHrP and SPARC and their prognostic value in 362 CRC human samples.Results: In GEPIA2 database, a significant correlation between the expressions ofPTHrP and SPARC in CRC was observed (p-value¼0.01). Also, SPARC expression washigher in CRC respect to colorectal normal samples (p-value¼0.01). In the same way,SPARC expression was significantly higher in CRC advanced than in early disease.Employing STRING 11.0 database, we observed a strong association between PTHrPand several oncogenic markers (CDH2, CD44, VIM, among others) that previouslywere evaluated in vitro by us linked through SPARC with a Protein-Protein interactionenrichment (p-value 0.95). This PN was merged with the PN obtained from the search?colorectal cancer? with a high disease score (SD> 3.2). From this analysis, VEGFA wasemerged as a central nexus between PTHrP and SPARC proteins. Finally, GEPIA2 wasused to evaluate the survival rate in CRC patients that express PTHrP and/or SPARC.No significant impact in overall survival was found taken account high or lowexpression of each protein.Conclusions: In CRC tumor samples, a strong relationship between PTHrP and SPARCexpression was found, suggesting that both proteins could be involved in the progression of the disease. Despite VEGFA was also associated with PTHrP/SPARC, morestudies are necessary to evaluate their clinical relevancy.Fil: Carriere, Pedro Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Novoa Díaz, María Belén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: López Moncada, Fernanda. Universidad de Chile. Facultad de Medicina.; ChileFil: Zwenger, A.. Centro de Estudios Clinicos SAGA; ChileFil: Contreras, H.. Universidad de Chile. Facultad de Medicina.; ChileFil: Calvo, Natalia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaFil: Gentili, Claudia Rosana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; ArgentinaESMO World Congress on Gastrointestinal Cancer 2021Modalidad virtualEstados UnidosEuropean Society for Medical Oncolog