Integrated AlGaN quadruple-band ultraviolet photodetectors

Cataloged from PDF version of article.Monolithically integrated quadruple back-illuminated ultraviolet metalsemiconductormetal photodetectors with four different spectral responsivity bands were demonstrated on each of two different Al xGa 1-xN heterostructures. The average of the full-width at half-maximum (FWHM) of the quantum efficiency peaks was 18.15nm for sample A, which incorporated five 1000nm thick epitaxial layers. In comparison, the average FWHM for sample B was 9.98 nm, which incorporated nine 500nm thick epitaxial layers. © 2012 IOP Publishing Ltd

AMPK Is the Crucial Target for the CDK4/6 Inhibitors Mediated Therapeutic Responses in PANC-1 and MIA PaCa-2 Pancreatic Cancer Cell Lines

The survival rate of pancreatic ductal adenocarcinoma (PDAC) patients is short, and PDAC is a cancer type that ranks fourth in the statistics regarding death due to cancer. Mutation in the KRAS gene, which plays a role in pancreatic cancer development, activates the PI3K/AKT/mTOR signaling pathway. The activity of the AMPK as a cellular energy sensor is one of the fundamental mechanisms that can induce effective therapeutic responses against CDK4/6 inhibitors via adjusting the cellular and tumor microenvironment stress management. The phosphorylation of AMPKα at the different phosphorylation residues such as Thr172 and Ser 377 causes metabolic differentiation in the cells following CDK4/6 inhibitor treatment in accordance with an increased cell cycle arrest and senescence under the control of different cellular players. In this study, we examined the competencies of the CDK4/6 inhibitors LY2835219 and PD-0332991 on the mechanism of cell survival and death based on AMPK signaling. Both CDK4/6 inhibitors LY2835219 and PD-0332991 modulated different molecular players on the PI3K/AKT/mTOR and AMPK signaling axis in different ways to reduce cell survival in a cell type dependent manner. These drugs are potential inducers of apoptosis and senescence that can alter the therapeutic efficacy cells

Emulation of X-ray Light-Field Cameras

X-ray plenoptic cameras acquire multi-view X-ray transmission images in a single exposure (light-field). Their development is challenging: designs have appeared only recently, and they are still affected by important limitations. Concurrently, the lack of available real X-ray light-field data hinders dedicated algorithmic development. Here, we present a physical emulation setup for rapidly exploring the parameter space of both existing and conceptual camera designs. This will assist and accelerate the design of X-ray plenoptic imaging solutions, and provide a tool for generating unlimited real X-ray plenoptic data. We also demonstrate that X-ray light-fields allow for reconstructing sharp spatial structures in three-dimensions (3D) from single-shot data

Dating and provenancing the <i>Woman with lantern</i> sculpture – A contribution towards attribution of Netherlandish art

Studying the wood of art objects such as sculptures, panel paintings and furniture can be crucial to elucidate their chronology and production centre. Here we present an approach that considers the provenance of the wood and its potential availability in different areas as a means to identify the provenance of wooden art objects. We illustrate this approach with an interdisciplinary study aimed to determine the date and provenance of the Woman with lantern, a carved altar fragment from the Rijksmuseum's collections (Amsterdam, The Netherlands). The origin of this object is undocumented, but based on stylistic and iconographic features its provenance was proposed to be the altarpiece of Rennes cathedral (France), carved in Antwerp (Belgium) around 1520 C.E. However, doubts arose when curators tested the potential fit of the sculpture in that altarpiece and could not find a neat match. Dating and provenancing the wood of the sculpture by standard dendrochronological means failed to produce a date, and comparison of the tree-ring pattern from the sculpture with those of the sculptures from Rennes altarpiece delivered no results either, supporting the suspicion that the Woman with lantern belonged elsewhere. In 2019, X-ray computed tomography (CT) provided digital cross-sections throughout the sculpture and a longer tree-ring series was obtained. This time, the outermost ring was dated to the year 1487 C.E. The tree was estimated to have been cut after 1495 C.E., indicating a likely production in the first quarter of the 16th century. The origin of the timber in the eastern Netherlands/northwest Germany, combined with empirical evidence about timber availability in various regions of the Low Countries at that time, suggests that the sculpture was made in a workshop located north of the Rhine in the (current) Netherlands, rather than Antwerp. This research has led to the hypothesis that workshops north and south of the Rhine river branches in the Low Countries were supplied by forests located in different areas. If proven correct, establishing the wood provenance will assist in determining the origin of Netherlandish works of art from the late-Gothic and Northern Renaissance periods

Malarial Hemozoin Is a Nalp3 Inflammasome Activating Danger Signal

BACKGROUND: Characteristic symptoms of malaria include recurrent fever attacks and neurodegeneration, signs that are also found in patients with a hyperactive Nalp3 inflammasome. Plasmodium species produce a crystal called hemozoin that is generated by detoxification of heme after hemoglobin degradation in infected red blood cells. Thus, we hypothesized that hemozoin could activate the Nalp3 inflammasome, due to its particulate nature reminiscent of other inflammasome-activating agents. METHODOLOGY/PRINCIPAL FINDINGS: We found that hemozoin acts as a proinflammatory danger signal that activates the Nalp3 inflammasome, causing the release of IL-1beta. Similar to other Nalp3-activating particles, hemozoin activity is blocked by inhibiting phagocytosis, K(+) efflux and NADPH oxidase. In vivo, intraperitoneal injection of hemozoin results in acute peritonitis, which is impaired in Nalp3-, caspase-1- and IL-1R-deficient mice. Likewise, the pathogenesis of cerebral malaria is dampened in Nalp3-deficient mice infected with Plasmodium berghei sporozoites, while parasitemia remains unchanged. SIGNIFICANCE/CONCLUSIONS: The potent pro-inflammatory effect of hemozoin through inflammasome activation may possibly be implicated in plasmodium-associated pathologies such as cerebral malaria

Malarial Hemozoin Is a Nalp3 Inflammasome Activating Danger Signal

BACKGROUND: Characteristic symptoms of malaria include recurrent fever attacks and neurodegeneration, signs that are also found in patients with a hyperactive Nalp3 inflammasome. Plasmodium species produce a crystal called hemozoin that is generated by detoxification of heme after hemoglobin degradation in infected red blood cells. Thus, we hypothesized that hemozoin could activate the Nalp3 inflammasome, due to its particulate nature reminiscent of other inflammasome-activating agents. METHODOLOGY/PRINCIPAL FINDINGS: We found that hemozoin acts as a proinflammatory danger signal that activates the Nalp3 inflammasome, causing the release of IL-1beta. Similar to other Nalp3-activating particles, hemozoin activity is blocked by inhibiting phagocytosis, K(+) efflux and NADPH oxidase. In vivo, intraperitoneal injection of hemozoin results in acute peritonitis, which is impaired in Nalp3-, caspase-1- and IL-1R-deficient mice. Likewise, the pathogenesis of cerebral malaria is dampened in Nalp3-deficient mice infected with Plasmodium berghei sporozoites, while parasitemia remains unchanged. SIGNIFICANCE/CONCLUSIONS: The potent pro-inflammatory effect of hemozoin through inflammasome activation may possibly be implicated in plasmodium-associated pathologies such as cerebral malaria

Effects of HIV-1 TAT protein and methamphetamine exposure on visual discrimination and executive function in mice

Mild neurocognitive impairments are common in people with human immunodeficiency virus (HIV) infection. HIV-encoded proteins, such as trans-activator of transcription (TAT), contribute to neuropathology and cognitive function in medicated subjects. The combination of TAT and comorbid methamphetamine use may further impair neurocognitive function in HIV-positive individuals by affecting dopaminergic systems in the brain. The current study examined the effects of TAT protein expression and methamphetamine exposure on cognitive function and dopamine systems in mice. Transgenic mice with inducible brain expression of the TAT protein were exposed to a binge methamphetamine regimen. TAT expression was induced via a doxycycline-containing diet during the final stage of the regimen and maintained throughout cognitive testing. Learning and executive function were assessed using an operant visual discrimination protocol, with a strategy switch and reversal. TAT expression and methamphetamine exposure improved visual discrimination learning. Combined TAT expression and methamphetamine exposure increased perseverative errors during reversal learning. TAT expression altered reversal learning by improving early stage, but impairing late stage, learning. TAT expression was also associated with an increase in dopamine transporter expression in the caudate putamen. These results highlight that TAT expression and methamphetamine exposure likely affect a range of selective cognitive processes, with some potentially improving function under certain conditions