High-order harmonic generation driven by chirped laser pulses induced by linear and non linear phenomena

We present a theoretical study of high-order harmonic generation (HHG) driven by ultrashort optical pulses with different kind of chirps. The goal of the present work is perform a detailed study to clarify the relevant parameters in the chirped pulses to achieve a noticeable cut-off extensions in HHG. These chirped pulses are generated using both linear and nonlinear dispersive media.The description of the origin of the physical mechanisms responsible of this extension is, however, not usually reported with enough detail in the literature. The study of the behaviour of the harmonic cut-off with these kind of pulses is carried out in the classical context, by the integration of the Newton-Lorentz equation complemented with the quantum approach, based on the integration of the time dependent Schr\"odinger equation in full dimensions (TDSE-3D), we are able to understand the underlying physics.Comment: 13 pages, 8 figure

Buried waveguides in Nd:YLF crystals obtained by femtosecond laser writing under double line approach

In this paper, we present buried waveguides fabricated by fs laser writing in Nd3+ doped YLF crystal under double line approach (Miura et al. in Appl. Phys. Lett. 71:3329–3331, 1997). The waveguides were made by focusing two consecutive optical breakdown tracks (OBT) separated by about 20 μm. To make the optimal OBT, we focused the fs-laser pulses 200 μm below surface at intensities above the OB threshold for the material and controlled the writing speed. The guiding structures were fabricated by using a Chirped Pulse Amplification (CPA) femtosecond (fs) laser system. We chose the optimal writing parameters in order to obtain suitable waveguides, using around 3 μJ energy and writing speed from 15 to 50 μm/s. After optically exploring the waveguides by end-fire coupling, the guiding structures showed good optical performance. Guiding index profiles were retrieved from modal analysis by using BeamProp (RSoft) commercial software. This spatial distribution of the index increment, taking into account a lower refractive barrier on the OBT region plus the compressed region between the tracks, was obtained correctly fitting profiles modes. Finally, optical spectroscopy measurements were also performed in the waveguides. The results showed that the luminescence properties of Nd3+ ions are preserved in the waveguides compared with the values obtained for bulk.This work was partially supported by Agencia Nacional de Promoción Científica y Tecnólogica. (Argentina) under project PICT-2575 and CONICET (Argentina) under project PIP 0394 and by “Ministerio de Educación y Ciencia,” Spain (Grant no FIS2009-09522 and Consolider Program SAUUL CSD2007-00013). D.B. wishes to thank Comisión de Investigaciones Científicas (Bs. As., Argentina) for his student fellowship

“Working the system”: The experience of being a primary care patient

Health care providers and system administrators are in the midst of a paradigm shift; moving from paternalism toward an egalitarian approach. For patient centred care to occur, health care providers must prioritize patient needs; provide information regarding treatments while taking patient preferences and expectations into account. While there is literature regarding patient centredness, there is less information from the patient perspective about the experience of being a patient and the influence on behaviour. Using phenomenological research methods and the theory of planned behaviour as a theoretical framework, this study addressed the questions, a) what is the essence of being a primary health care patient, and b) what influence do beliefs, attitudes, and experience have on people’s behaviour as a patient? Nineteen individuals participated. Seven shared elements of being a primary health care patient were identified and contributed to the development of a composite vignette. The patient experience was a socially oriented, governed and reinforced cyclical process. Patients described themselves as actively engaged in their health care – “working the system” to get what they needed, when they needed it. Patients changed their beliefs, attitudes and behaviour as a result of experiences with their physicians, and their perceived success or failure in acquiring the best health care possible. Being a patient was not a single, observable behaviour, but rather a set of contextually dependent strategies patients’ directed at the specific goal of getting the best healthcare possible. The theory of planned behaviour was unsuitable for understanding patients’ beliefs, attitudes and behaviour

Identification of a rare de novo three-way complex t(5;20;8)(q31;p11.2;p21) with microdeletions on 5q31.2, 5q31.3, and 8p23.2 in a patient with hearing loss and global developmental delay: case report

<p>Abstract</p> <p>Background</p> <p>Complex chromosome rearrangements (CCRs), which involve more than two breakpoints on two or more chromosomes, are uncommon occurrences. Although most CCRs appear balanced at the level of the light microscope, many demonstrate cryptic, submicroscopic imbalances at the translocation breakpoints.</p> <p>Results</p> <p>We report a female with hearing loss and global developmental delay with a complex three-way unbalanced translocation (5;20;8)(q31;p11.2;p21) resulting in microdeletions on 5q31.2, 5q31.3, and 8p23.2 identified by karyotyping, microarray analysis and fluorescence in situ hybridization.</p> <p>Discussion</p> <p>The microdeletion of bands 8p23.2 may be associated with the hearing impairment. Furthermore, the characterization of this patient's chromosomal abnormalities demonstrates the importance of integrated technologies within contemporary cytogenetics laboratories.</p

Disrupting the DREAM transcriptional repressor complex induces apolipoprotein overexpression and systemic amyloidosis in mice

DREAM (Dp, Rb-like, E2F, and MuvB) is a transcriptional repressor complex that regulates cell proliferation, and its loss causes neonatal lethality in mice. To investigate DREAM function in adult mice, we used an assembly-defective p107 protein and conditional deletion of its redundant family member p130. In the absence of DREAM assembly, mice displayed shortened survival characterized by systemic amyloidosis but no evidence of excessive cellular proliferation. Amyloid deposits were found in the heart, liver, spleen, and kidneys but not the brain or bone marrow. Using laser-capture microdissection followed by mass spectrometry, we identified apolipoproteins as the most abundant components of amyloids. Intriguingly, apoA-IV was the most detected amyloidogenic protein in amyloid deposits, suggesting apoA-IV amyloidosis (AApoAIV). AApoAIV is a recently described form, whereby WT apoA-IV has been shown to predominate in amyloid plaques. We determined by ChIP that DREAM directly regulated Apoa4 and that the histone variant H2AZ was reduced from the Apoa4 gene body in DREAM\u27s absence, leading to overexpression. Collectively, we describe a mechanism by which epigenetic misregulation causes apolipoprotein overexpression and amyloidosis, potentially explaining the origins of nongenetic amyloid subtypes