534 research outputs found
Growth of [110] LaSrMnO - YBaCuO heterostructures
YBaCuO - LaSrMnO heterostructures
of [110] orientation are grown to allow direct injection of spin polarized
holes from the LaSrMnO into the CuO
superconducting planes. The magnetic response of the structure at T
T shows both diamagnetic and ferromagnetic moments with [001] direction
as magnetic easy axis. While the superconducting transition temperature
(T) of these structures is sharp (T 2.5 K), the
critical current density (J) follows a dependence of the type with highly suppressed J ( A/cm) indicating strong pair breaking effects of the ferromagnetic
boundary.Comment: 12 pages five figure
Solar Carports: Assessment of Open Parking Lots to Locate Potential Solar Carport Installations for Power Generation at the University of Illinois at Urbana-Champaign
This report documents the requirements, methodologies and results of performing an assessment of the open parking lots at the campus of the University of Illinois at Urbana-Champaign for identifying potential locations for installation of solar carports and the generation of clean energy. The assessment of feasibility for the installation of solar carports in the open parking lots on campus can be regarded as an attempt at evaluating analytically the prospective contribution of such an installation towards the achievement of carbon neutrality on campus. The report also suggests the ways in which the results can be utilized by the campus and enumerates the learnings and limitations from the exercise carried out. The methodology to ascertain the solar power generation potential from solar carports involved identification of open parking lots, delineation of parking spaces for possible solar carport installation and calculation of the energy potential. All open parking lots on campus were assessed and 65.75 acres of parking lot areas were delineated for possible solar carport installation. The potential to harness clean energy from these solar carports ranges from 28.94 GWh to 46.3 GWh.University of Illinois Facilities and ServicesOpe
Adaptive resistance to RAF inhibitors in melanoma.
The discovery of activating mutations in BRAF at high frequency in cutaneous melanoma opened the door to new treatment options, which have resulted in significantly better patient outcomes. Treatments such as the FDA-approved RAF inhibitor vemurafenib and the more recently approved dabrafenib and trametinib combination therapy are designed to target the ERK1/2 pathway. Initial success in targeting this pathway is evidenced by the high percentage of melanoma patients who undergo tumor remission. However, the beneficial effects of these targeted therapies are usually short-lived due to the development of resistance, which leads to disease progression. As a result, studies have focused on the acquired forms of resistance that develop following continued exposure to therapy. Conversely, far fewer studies have investigated the adaptive forms of resistance, which activate rapidly, promote cell survival, and may underlie the development of acquired resistance by providing melanoma cells the time to develop additional mutations. We provide a detailed review of the known mechanisms of adaptive resistance in melanoma and relate them to similar responses to targeted therapies in other tumor types
Percolative transport in the vicinity of charge-order ferromagnetic transition in a hole-doped manganite
We report measurements of non-linear charge transport in epitaxial (La1-x Pr x )0.7Ca0.3MnO3 thin films fabricated on (100) oriented SrTiO3 single crystals by pulsed laser deposition. The end members of this series, namely Pr0.7Ca0.3MnO3 and La0.7Ca0.3MnO3 are canonical charge-ordered (CO) and ferromagnetic manganites, respectively. The onset of the CO state in Pr0.7Ca0.3MnO3 is manifested by a pronounced insulating behavior below ~ 200 K. The CO state remains stable even when a large (~ 2×105 V/cm) electric field is applied across the thin film samples. However, on substitution of Pr with La, a crossover from the highly resistive CO state to a state of metallic character is observed at relatively low electric fields. The current-voltage characteristics of the samples at low temperatures show hysteretic and history dependent effects. The electric field driven charge transport in the system is modelled on the basis of an inhomogeneous medium consisting of ferromagnetic metallic clusters dispersed in a CO background
Molecular alterations of Ras-Raf-mitogen-activated protein kinase and phosphatidylinositol 3-kinase-Akt signaling pathways in colorectal cancers from a tertiary hospital at Kuala Lumpur, Malaysia
Molecular alterations in KRAS, BRAF, PIK3CA, and PTEN have been implicated in designing targeted therapy for colorectal cancer (CRC). The present study aimed to determine the status of these molecular alterations in Malaysian CRCs as such data are not available in the literature. We investigated the mutations of KRAS, BRAF, and PTEN, the gene amplification of PIK3CA, and the protein expression of PTEN and phosphatidylinositol 3-kinase (PI3K) catalytic subunit (p110α) by direct DNA sequencing, quantitative real-time PCR, and immunohistochemistry, respectively, in 49 CRC samples. The frequency of KRAS (codons 12, 13, and 61), BRAF (V600E), and PTEN mutations, and PIK3CA amplification was 25.0% (11/44), 2.3% (1/43), 0.0% (0/43), and 76.7% (33/43), respectively. Immunohistochemical staining demonstrated loss of PTEN protein in 54.5% (24/44) of CRCs and no significant difference in PI3K p110α expression between CRCs and the adjacent normal colonic mucosa (p = 0.380). PIK3CA amplification was not associated with PI3K p110α expression level, but associated with male cases (100% of male cases vs 56% of female cases harbored amplified PIK3CA, p = 0.002). PI3K p110α expression was significantly higher (p = 0.041) in poorly/moderately differentiated carcinoma compared with well-differentiated carcinoma. KRAS mutation, PIK3CA amplification, PTEN loss, and PI3K p110α expression did not correlate with Akt phosphorylation or Ki-67 expression. KRAS mutation, PIK3CA amplification, and PTEN loss were not mutually exclusive. This is the first report on CRC in Malaysia showing comparable frequency of KRAS mutation and PTEN loss, lower BRAF mutation rate, higher PIK3CA amplification frequency, and rare PTEN mutation, as compared with published reports
Tumour Cell Heterogeneity.
The population of cells that make up a cancer are manifestly heterogeneous at the genetic, epigenetic, and phenotypic levels. In this mini-review, we summarise the extent of intra-tumour heterogeneity (ITH) across human malignancies, review the mechanisms that are responsible for generating and maintaining ITH, and discuss the ramifications and opportunities that ITH presents for cancer prognostication and treatment
Visible light-mediated difluoromethylation/cyclization in batch and flow: scalable synthesis of CHF<sub>2</sub>-containing benzimidazo- and indolo[2,1-<i>a</i>]isoquinolin-6(5<i>H</i>)-ones
We report here a practical and cost-effective method for the synthesis of CHF2-containing benzimidazo- and indolo[2,1,a]-isoquinolin-6(5H)-ones through a visible light-mediated difluoromethylation/cyclization cascade. The method, which affords functionalized multifused N-heterocyclic scaffolds in moderate to high yields under mild reaction conditions, is also easily scalable using low-cost 3D printed photoflow reactors
Unresponsiveness of colon cancer to BRAF(V600E) inhibition through feedback activation of EGFR
Withania somnifera Root Extract Enhances Chemotherapy through ‘Priming’
Withania somnifera extracts are known for their anti-cancerous, anti-inflammatory and antioxidative properties. One of their mechanisms of actions is to modulate mitochondrial function through increasing oxidative stress. Recently ‘priming’ has been suggested as a potential mechanism for enhancing cancer cell death. In this study we demonstrate that ‘priming’, in HT-29 colon cells, with W. somnifera root extract increased the potency of the chemotherapeutic agent cisplatin. We have also showed the W. somnifera root extract enhanced mitochondrial dysfunction and that the underlying mechanism of ‘priming’ was selectively through increased ROS. Moreover, we showed that this effect was not seen in non-cancerous cells
The spoken web search task at MediaEval 2011
In this paper, we describe the “Spoken Web Search” Task, which was held as part of the 2011 MediaEval benchmark campaign. The purpose of this task was to perform audio search with audio input in five languages, with very little resources being available in each language. The data was taken from “spoken web” material collected over a mobile phone connection by IBM India. We present results from several ndependent systems, developed by five teams and using different approaches, compare and fus
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