32 research outputs found
Giant photoelasticity of polaritons for detection of coherent phonons in a superlattice with quantum sensitivity
The functionality of phonon-based quantum devices largely depends on the
efficiency of interaction of phonons with other excitations. For phonon
frequencies above 20 GHz, generation and detection of the phonon quanta can be
monitored through photons. The photon-phonon interaction can be enormously
strengthened by involving an intermediate resonant quasiparticle, e.g. an
exciton, with which a photon forms a polariton. In this work, we discover a
giant photoelasticity of exciton-polaritons in a short-period superlattice and
exploit it for detecting propagating acoustic phonons. We demonstrate that 42
GHz coherent phonons can be detected with extremely high sensitivity in the
time domain Brillouin oscillations by probing with photons in the spectral
vicinity of the polariton resonance.Comment: 6 pages, 3 figures, Supplemental Material
On-chip phonon-magnon reservoir for neuromorphic computing
Reservoir computing is a concept involving mapping signals onto a high-dimensional phase space of a dynamical system called “reservoir” for subsequent recognition by an artificial neural network. We implement this concept in a nanodevice consisting of a sandwich of a semiconductor phonon waveguide and a patterned ferromagnetic layer. A pulsed write-laser encodes input signals into propagating phonon wavepackets, interacting with ferromagnetic magnons. The second laser reads the output signal reflecting a phase-sensitive mix of phonon and magnon modes, whose content is highly sensitive to the write- and read-laser positions. The reservoir efficiently separates the visual shapes drawn by the write-laser beam on the nanodevice surface in an area with a size comparable to a single pixel of a modern digital camera. Our finding suggests the phonon-magnon interaction as a promising hardware basis for realizing on-chip reservoir computing in future neuromorphic architectures
On-chip phonon-magnon reservoir for neuromorphic computing
Reservoir computing is a concept involving mapping signals onto a high-dimensional phase space of a dynamical system called "reservoir" for subsequent recognition by an artificial neural network. We implement this concept in a nanodevice consisting of a sandwich of a semiconductor phonon waveguide and a patterned ferromagnetic layer. A pulsed write-laser encodes input signals into propagating phonon wavepackets, interacting with ferro-magnetic magnons. The second laser reads the output signal reflecting a phase-sensitive mix of phonon and magnon modes, whose content is highly sensitive to the write-and read-laser positions. The reservoir efficiently separates the visual shapes drawn by the write-laser beam on the nanodevice surface in an area with a size comparable to a single pixel of a modern digital camera. Our finding suggests the phonon-magnon interaction as a promising hardware basis for realizing on-chip reservoir computing in future neuro-morphic architectures
A high throughput genotyping approach reveals distinctive autosomal genetic signatures for European and Near Eastern wild boar
The lack of a Near Eastern genetic signature in modern European porcine breeds indicates that, although domestic pigs from the Fertile Crescent entered Europe during the Neolithic, they were completely replaced by their European counterparts in a short window of time. Whilst the absence of such genetic signature has been convincingly demonstrated at the mitochondrial level, variation at the autosomal genomes of European and Near Eastern Sus scrofa has not been compared yet. Herewith, we have explored the genetic relationships among 43 wild boar from Europe (N = 21), Near East (N = 19) and Korea (N = 3), and 40 Iberian (N = 16), Canarian (N = 4) and Mangalitza (N = 20) pigs by using a high throughput SNP genotyping platform. After data filtering, 37,167 autosomal SNPs were used to perform population genetics analyses. A multidimensional scaling plot based on genome-wide identity-by-state pairwise distances inferred with PLINK showed that Near Eastern and European wild boar populations are genetically differentiated. Maximum likelihood trees built with TreeMix supported this conclusion i.e. an early population split between Near Eastern and European Sus scrofa was observed. Moreover, analysis of the data with Structure evidenced that the sampled Iberian, Canarian and Mangalitza pigs did not carry any autosomal signature compatible with a Near Eastern ancestry, a finding that agrees well with previous mitochondrial studies
Targeting AKT Kinase in Hydroxytamoxifen-Resistant Breast Cancer Cells
More than 650,000 people die each year from breast cancer, making it a particularly significant disease worldwide. The development of about 70% of breast tumors depends on steroid hormones, namely, estrogens. Estrogens trigger signaling pathways that support tumor growth and progression. Hydroxytamoxifen (HT) halting estrogen-induced tumor growth is among the most effective drugs in current anticancer therapy. The purpose of this work was to investigate approaches to overcome breast cancer cell resistance to hydroxytamoxifen. Cells with resistance to the antiestrogen hydroxytamoxifen were obtained by long-term incubation of parental MCF7 cells with this drug. Estrogen receptor α (ERα) expression and progesterone receptor (PR) expression were analyzed by immunoblotting. The resistant MCF7/HT cells were found not to lose ERα expression. These cells were found to have slightly reduced ERα activity when compared to parental MCF7 cells. The expression of PR, one of the ERα targets, was downregulated in hydroxytamoxifen-resistant cells. AKT kinase belongs to the PI3K/AKT/mTOR signaling pathway, and its activity is associated with resistance. Three types of AKT inhibitors were evaluated, including AKT inhibitor IV (6-(2-benzothiazolyl)-1-ethyl-2-[2-(methylphenylamino)ethenyl]-3-phenyl-1H-benzimidazolium, monoiodide), 10-DEBC (2-chloro-N,N-diethyl-10H-phenoxazine-10-butanamine, monohydrochloride), and luminespib (HSP90 inhibitor, 5-[2,4-dihydroxy-5-(1-methylethyl)phenyl]-N-ethyl-4-[4-(4-morpholinylmethyl)phenyl]-3-isoxazolecarboxamide). All three compounds showed high antiproliferative activity against hydroxytamoxifen-resistant cells. The IC50 value of 10-DEBC was 4.2 µM, and this was when the AKT inhibitor IV was more active with IC50 value of 390 nM. The HSP90 inhibitor luminespib, which reduces AKT expression, showed the highest activity against parental and hydroxytamoxifen-resistant breast cancer cells, with IC50 values of 14 and 18 nM, respectively. Thus, the hydroxytamoxifen-resistant cells were found to partially retain hormone signaling and to be sensitive to selective AKT inhibitors. The best effects were discovered for HSP90-AKT blocker luminespib, with an IC50 value of about 20 nM
Novel Water-Soluble Far-Red Nitroreductase-Responsive Bodipy-Based Fluorescent Probe for the Detection of Hypoxic Status in A549 Non-Small Cell Lung Cancer Cells
Over expression of nitroreductase (NTR) enzymes is closely related to the hypoxic status in living organisms for which molecular oxygen is vital. The development of effective methods for real-time monitoring of NTR activity is of great significance for medical diagnosis and cancer research. Here, we present a novel water-soluble Bodipy-based chemodosimeter (NBB) effective in imaging the hypoxic status of human non-small-cell lung cancer A549 cells. We assumed that NTR-mediated activation of the probe NBB is based on the reductive release of meso-phenol Bodipy dye to finally produce unusual fluorescence "ON-OFF" response
Essential Oil from Melaleuca leucadendra: Antimicrobial, Antikinetoplastid, Antiproliferative and Cytotoxic Assessment
Essential oils (EOs) are known for their use in cosmetics, food industries, and traditional medicine. This study presents the chemical composition and therapeutic properties against kinetoplastid and eukaryotic cells of the EO from Melaleucaleucadendra (L.) L. (Myrtaceae). Forty-five compounds were identified in the oil by GC-MS, containing a major component the 1,8-cineole (61%). The EO inhibits the growth of Leishmania amazonensis and Trypanosoma brucei at IC50 values <10 μg/mL. However, 1,8 cineole was not the main compound responsible for the activity. Against malignant (22Rv1, MCF-7, EFO-21, including resistant sublines MCF-7/Rap and MCF-7/4OHTAMO) and non-malignant (MCF-10A, J774A.1 and peritoneal macrophage) cells, IC50 values from 55 to 98 μg/mL and from 94 to 144 μg/mL were obtained, respectively. However, no activity was observed on Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Pseudomonas aeruginosa, Aspergillus niger, Candida parapsilosis, Microsporum canis, or Trypanosoma cruzi. The EO was able to control the lesion size and parasite burden in the model of cutaneous leishmaniasis in BALB/c mice caused by L. amazonensis compared to untreated animals (p < 0.05) and similar with those treated with Glucantime® (p > 0.05). This work constitutes the first evidence of antiproliferative potentialities of EO from M. leucadendra growing in Cuba and could promote further preclinical investigations to confirm the medical value of this plant, in particular for leishmaniasis treatment
Essential oil from Melaleuca leucadendra : antimicrobial, antikinetoplastid, antiproliferative and cytotoxic assessment
Results and prospects of development of new polyphenolic drugs for cancer patients
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