28 research outputs found
All-Optical tunability of metalenses infiltrated with liquid crystals
Metasurfaces have been extensively engineered to produce a wide range of
optical phenomena, allowing unprecedented control over the propagation of
light. However, they are generally designed as single-purpose devices without a
modifiable post-fabrication optical response, which can be a limitation to
real-world applications. In this work, we report a nanostructured planar fused
silica metalens permeated with a nematic liquid crystal (NLC) and gold
nanoparticle solution. The physical properties of embedded NLCs can be
manipulated with the application of external stimuli, enabling reconfigurable
optical metasurfaces. We report all-optical, dynamic control of the metalens
optical response resulting from thermo-plasmonic induced changes of the NLC
solution associated with the nematic-isotropic phase transition. A continuous
and reversible tuning of the metalens focal length is experimentally
demonstrated, with a variation of 80 um (0.16% of the 5 cm nominal focal
length) along the optical axis. This is achieved without direct mechanical or
electrical manipulation of the device. The reconfigurable properties are
compared with corroborating numerical simulations of the focal length shift and
exhibit close correspondence.Comment: Main tex
The Role of microRNA in Head and Neck Cancer: Current Knowledge and Perspectives
Head and neck cancer is one of the most commonly diagnosed malignancies worldwide. Patients with advanced disease stages frequently develop recurrences or distant metastasis, which results a five-year survival rates of less than 60% despite considerable advances in multimodality therapy. A better understanding of molecular basis of tumorigenesis is required to improve clinical outcomes and to develop new anti-cancer drugs. microRNAs (miRNAs) are a class of small, non-coding, RNA molecules that modulate gene expression post-transcriptionally. They are important regulator in normal biological process; however miRNAs deregulation has been observed in many different tumors and is involved in tumorigenesis. miRNAs may act as tumor suppressors or as oncogenes. Several studies on head and neck cancer demonstrated how aberrant expression of miRNAs is involved in proliferation, metastasis, chemoresistence, and radioresistance. In addition, miRNAs are excellent biomarker targets because they circulate stable in human body fluids and can be obtained with non-invasive methods. Moreover, miRNAs up and down regulation has been correlated with specific cancer phenotype (poor prognosis, aggressiveness and resistance to treatment), playing a role as prognostic biomarkers. This review summarizes current finding on miRNAs in head and neck cancer and their potential role as target for next drug therapy
Longâterm survival of an advanced colorectal cancer patient treated with Regorafenib: Case report and literature review
Protective effect of pioglitazone, a PPARÎł ligand, in a 3 nitropropionic acid model of Huntington's disease
The peroxisome proliferator-activated receptor gamma (PPAR gamma) is a member of the PPAR family. PPAR gamma is the target of insulin-sensitising thiazolidinediones (TZDs), drugs used for the treatment of non-insulin-dependent diabetes. Recently, several studies have shown that PPAR gamma activators can also prevent or attenuate neurodegeneration. The PPAR gamma agonist pioglitazone provides neuroprotection to dopaminergic neurons in lipopolysaccharide (LPS) and MPTP-induced Parkinson's disease experimental models. Here, we investigated whether PPAR gamma activation by pioglitazone protected striatal cells from mitochondrial dysfunction and oxidative stress in a 3 nitropropionic acid (3NP)-induced experimental model of Huntington's disease (HD). Our results suggested that pioglitazone has beneficial effects on mitochondrial dysfunction by interfering with the NF-kappa B signalling pathway, which has been implicated in the pathogenesis of HD. Additionally, we demonstrated that the nuclear translocation of HDAC3 is regulated by 3NP via I kappa B alpha and that treatment with pioglitazone prevented these effects. These results suggested that I kappa B alpha-dependent nuclear translocation is responsible for PPAR gamma inhibition by 3NP and pointed to histone modifications as a novel approach for treating HD. (C) 2011 Elsevier Inc. All rights reserved
A Luminescent, Water-Soluble Ir(III) Complex as a Potential Photosensitizer for Two-Photon Photodynamic Therapy
International audienceThis work reports the study of two-photon induced properties of a highly luminescent cyclometalated Ir(III) complex, [Ir(ppy)2(en)] OOCCH3 (1), ppy = 2-phenylpyridine, en = ethylenediamine. Steady-state and time-resolved fluorescence measurements were performed by exciting 1 at the biologically relevant wavelength of 800 nm, whereas, the generation of singlet oxygen (1O2) was evaluated using 9,10-Anthracenediyl-bis(methylene)dimalonic acid (ABDA) as a detection probe. Preliminary in vitro experiments with U87-MG cells were performed, showing the potential of this compound as a two-photon photodynamic therapy (2P-PDT) agent at NIR wavelengths
Third-line trabectedin for a metastatic desmoplastic small round cell tumour treated with multimodal therapy
Desmoplastic small round cell tumour (DSRCT) is a rare and aggressive cancer that usually develops in the peritoneal cavity of young males. Its prognosis is dismal, with current treatment options including the combination of multi-agent chemotherapy, aggressive surgery, radiation therapy, and autologous stem cell transplantation. Hyperthermic intraperitoneal chemotherapy (HIPEC) may also be an option
Cognitive-behavioural phenotype in a group of girls from 1.2 to 12 years old with the Incontinentia Pigmenti syndrome: recommendations for clinical management
Incontinentia Pigmenti (IP, OMIM#308300) is a rare X-linked genomic disorder (about 1,400 cases)
that affects the neuroectodermal tissue and Central Nervous System (CNS). The objective of this
study was to describe the cognitive-behavioural profile in children in order to plan a clinical
intervention to improve their quality of life. A total of 14 girls (age range: from 1 year and 2 months
to 12 years and 10 months) with IP and the IKBKG/NEMO gene deletion were submitted to a
cognitive assessment including intelligence scales, language and visuo-spatial competence tests,
learning ability tests, and a behavioural assessment. Five girls had severe to mild intellectual
deficiencies and the remaining nine had a normal neurodevelopment. Four girls were of school age
and two of these showed no intellectual disability, but had specific disabilities in calculation and
arithmetic reasoning. This is the first description of the cognitive-behavioural profile in relation to
developmental age. We stress the importance of an early assessment of learning abilities in
individuals with IP without intellectual deficiencies to prevent the onset of any such deficit
Thermoplasmonic Effects in Gain-Assisted Nanoparticle Solutions
We
report a detailed characterization of the photoinduced heating
observed in gain-assisted solutions of gold nanoparticles (AuNPs).
AuNPs, with sizes ranging from 14 to 48 nm and concentration of 2.5
Ă 10<sup>â10</sup> M, are exposed to different intensity
values of a resonant continuous laser (532 nm), used to excite their
localized surface plasmon resonance (LSPR), responsible for the photogeneration
process. In this way the optimal conditions to achieve the maximum
temperature variation with the least laser dosage are obtained. By
addition of an organic dye to the solutions, whose emission band overlaps
to the LSPR, we found that the contribution to the photothermal efficiency
is enhanced if the solutions are excited at 405 nm. This happens in
the case of smaller NPs, due to a strong coupling effect between the
two subunits, which causes an increase of the extinction cross section
of the whole gain-assisted system. On the other hand, for the larger
AuNPs, an opposite behavior is found: a loss compensation mechanism,
based on a resonant energy transfer process from gain units to plasmonic
nanoparticles, limits the increase of the absorption cross section
with a consequent lowering of the photothermal efficiency. The presented
quantitative analysis of a dispersion of AuNPs results as fundamental
for biomedical applications as well as for integrated plasmonic devices
based on loss compensation effects, where the impact of undesirable
thermal effects cannot be ignored