131 research outputs found

    Ultrathin 2 nm gold as ideal impedance-matched absorber for infrared light

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    Thermal detectors are a cornerstone of infrared (IR) and terahertz (THz) technology due to their broad spectral range. These detectors call for suitable broad spectral absorbers with minimalthermal mass. Often this is realized by plasmonic absorbers, which ensure a high absorptivity butonly for a narrow spectral band. Alternativly, a common approach is based on impedance-matching the sheet resistance of a thin metallic film to half the free-space impedance. Thereby, it is possible to achieve a wavelength-independent absorptivity of up to 50 %, depending on the dielectric properties of the underlying substrate. However, existing absorber films typicallyrequire a thickness of the order of tens of nanometers, such as titanium nitride (14 nm), whichcan significantly deteriorate the response of a thermal transducers. Here, we present the application of ultrathin gold (2 nm) on top of a 1.2 nm copper oxide seed layer as an effective IR absorber. An almost wavelength-independent and long-time stable absorptivity of 47(3) %, ranging from 2 μ\mum to 20 μ\mum, could be obtained and is further discussed. The presented gold thin-film represents analmost ideal impedance-matched IR absorber that allows a significant improvement of state-of-the-art thermal detector technology

    Effect of obesity on intraoperative bleeding volume in open gastrectomy with D2 lymph-node dissection for gastric cancer

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    <p>Abstract</p> <p>Background</p> <p>To investigate the effect of obesity on open gastrectomy with D2 lymph-node dissection.</p> <p>Methods</p> <p>Between January 2005 and March 2007, 100 patients with preoperatively diagnosed gastric cancer who underwent open gastrectomy with D2 lymph-node dissection were enrolled in this study. Of these, 61 patients underwent open distal gastrectomy (ODG) and 39 patients underwent open total gastrectomy (OTG). Patients were classified as having a high body-mass index (BMI; ≥ 25.0 kg/m<sup>2</sup>; <it>n </it>= 21) or a normal BMI (<25.0 kg/m<sup>2</sup>; <it>n </it>= 79). The visceral fat area (VFA) and subcutaneous fat area (SFA) were assessed as identifiers of obesity using FatScan software. Patients were classified as having a high VFA (≥ 100 cm<sup>2</sup>; <it>n </it>= 34) or a normal VFA (<100 cm<sup>2</sup>; <it>n </it>= 66). The relationship between obesity and short-term patient outcomes after open gastrectomy was evaluated. Patients were classified as having high intraoperative blood loss (IBL; ≥ 300 ml; <it>n </it>= 42) or low IBL (<300 ml; <it>n </it>= 58). Univariate and multivariate analyses were used to identify predictive factors for high IBL.</p> <p>Results</p> <p>Significantly increased IBL was seen in the following: patients with high BMI versus normal BMI; patients with gastric cancer in the upper third of the stomach versus gastric cancer in the middle or lower third of the stomach; patients who underwent OTG versus ODG; patients who underwent splenectomy versus no splenectomy; and patients with high VFA versus low VFA. BMI and VFA were significantly greater in the high IBL group than in the low IBL group. There was no significant difference in morbidity between the high IBL group and the low IBL group. Multivariate analysis revealed that patient age, OTG and high BMI or high VFA independently predicted high IBL.</p> <p>Conclusion</p> <p>It is necessary to perform operative manipulations with particular care in patients with high BMI or high VFA in order to reduce the IBL during D2 gastrectomy.</p

    Injection of Human Bone Marrow and Mononuclear Cell Extract into Infarcted Mouse Hearts Results in Functional Improvement

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    Background: We have previously shown that mouse whole bone marrow cell (BMC) extract results in improvement of cardiac function and decreases scar size in a mouse model of myocardial infarction (MI), in the absence of intact cells. It is not clear if thes

    MIQuant – Semi-Automation of Infarct Size Assessment in Models of Cardiac Ischemic Injury

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    BACKGROUND: The cardiac regenerative potential of newly developed therapies is traditionally evaluated in rodent models of surgically induced myocardial ischemia. A generally accepted key parameter for determining the success of the applied therapy is the infarct size. Although regarded as a gold standard method for infarct size estimation in heart ischemia, histological planimetry is time-consuming and highly variable amongst studies. The purpose of this work is to contribute towards the standardization and simplification of infarct size assessment by providing free access to a novel semi-automated software tool. The acronym MIQuant was attributed to this application. METHODOLOGY/PRINCIPAL FINDINGS: Mice were subject to permanent coronary artery ligation and the size of chronic infarcts was estimated by area and midline-length methods using manual planimetry and with MIQuant. Repeatability and reproducibility of MIQuant scores were verified. The validation showed high correlation (r(midline length) = 0.981; r(area) = 0.970 ) and agreement (Bland-Altman analysis), free from bias for midline length and negligible bias of 1.21% to 3.72% for area quantification. Further analysis demonstrated that MIQuant reduced by 4.5-fold the time spent on the analysis and, importantly, MIQuant effectiveness is independent of user proficiency. The results indicate that MIQuant can be regarded as a better alternative to manual measurement. CONCLUSIONS: We conclude that MIQuant is a reliable and an easy-to-use software for infarct size quantification. The widespread use of MIQuant will contribute towards the standardization of infarct size assessment across studies and, therefore, to the systematization of the evaluation of cardiac regenerative potential of emerging therapies

    Liver fibrosis secondary to bile duct injury: correlation of Smad7 with TGF-β and extracellular matrix proteins

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    <p>Abstract</p> <p>Background</p> <p>Liver fibrosis is the result of continuous liver injury stemming from different etiological factors. Bile duct injury induces an altered expression of TGF-β, which has an important role in liver fibrosis because this cytokine induces the expression of target genes such as collagens, PAI-1, TIMPs, and others that lead to extracellular matrix deposition. Smad7 is the principal inhibitor that regulates the target gene transcription of the TGF-β signaling. The aim of the study was to determine whether Smad7 mRNA expression correlates with the gene expression of <it>TGF-β, Col I</it>, <it>Col III</it>, <it>Col IV</it>, or <it>PAI-1 </it>in liver fibrosis secondary to bile duct injury (BDI).</p> <p>Results</p> <p>Serum TGF-β concentration was higher in BDI patients (39 296 pg/ml) than in liver donors (9008 pg/ml). Morphometric analysis of liver sections showed 41.85% of tissue contained fibrotic deposits in BDI patients. mRNA expression of Smad7, Col I, and PAI-1 was also significantly higher (<it>P </it>< 0.05) in patients with BDI than in controls. Smad7 mRNA expression correlated significantly with TGF-β concentration, Col I and Col III expression, and the amount of fibrosis.</p> <p>Conclusion</p> <p>We found augmented serum concentration of TGF-β and an increase in the percentage of fibrotic tissue in the liver of BDI patients. Contrary to expected results, the 6-fold increase in <it>Smad7 </it>expression did not inhibit the expression of <it>TGF-β, collagens</it>, and <it>PAI-1</it>. We also observed greater expression of Col I and Col III mRNA in BDI patients and significant correlations between their expression and TGF-β concentration and Smad7 mRNA expression.</p

    Citizen science: a new approach to advance ecology, education, and conservation

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    Citizen science has a long history in the ecological sciences and has made substantial contributions to science, education, and society. Developments in information technology during the last few decades have created new opportunities for citizen science to engage ever larger audiences of volunteers to help address some of ecology’s most pressing issues, such as global environmental change. Using online tools, volunteers can find projects that match their interests and learn the skills and protocols required to develop questions, collect data, submit data, and help process and analyze data online. Citizen science has become increasingly important for its ability to engage large numbers of volunteers to generate observations at scales or resolutions unattainable by individual researchers. As a coupled natural and human approach, citizen science can also help researchers access local knowledge and implement conservation projects that might be impossible otherwise. In Japan, however, the value of citizen science to science and society is still underappreciated. Here we present case studies of citizen science in Japan, the United States, and the United Kingdom, and describe how citizen science is used to tackle key questions in ecology and conservation, including spatial and macro-ecology, management of threatened and invasive species, and monitoring of biodiversity. We also discuss the importance of data quality, volunteer recruitment, program evaluation, and the integration of science and human systems in citizen science projects. Finally, we outline some of the primary challenges facing citizen science and its future.Dr. Janis L. Dickinson was the keynote speaker at the international symposium at the 61th annual meeting of the Ecological Society of Japan. We appreciate the Ministry of Education, Culture, Sports, Science and Technology in Japan for providing grant to Hiromi Kobori (25282044). Tatsuya Amano is financially supported by the European Commission’s Marie Curie International Incoming Fellowship Programme (PIIF-GA-2011- 303221). The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the funding agencies or the Department of the Interior or the US Government.This is the final version of the article. It was first available from Springer via http://dx.doi.org/10.1007/s11284-015-1314-

    Glutamate, GABA and Acetylcholine Signaling Components in the Lamina of the Drosophila Visual System

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    Synaptic connections of neurons in the Drosophila lamina, the most peripheral synaptic region of the visual system, have been comprehensively described. Although the lamina has been used extensively as a model for the development and plasticity of synaptic connections, the neurotransmitters in these circuits are still poorly known. Thus, to unravel possible neurotransmitter circuits in the lamina of Drosophila we combined Gal4 driven green fluorescent protein in specific lamina neurons with antisera to γ-aminobutyric acid (GABA), glutamic acid decarboxylase, a GABAB type of receptor, L-glutamate, a vesicular glutamate transporter (vGluT), ionotropic and metabotropic glutamate receptors, choline acetyltransferase and a vesicular acetylcholine transporter. We suggest that acetylcholine may be used as a neurotransmitter in both L4 monopolar neurons and a previously unreported type of wide-field tangential neuron (Cha-Tan). GABA is the likely transmitter of centrifugal neurons C2 and C3 and GABAB receptor immunoreactivity is seen on these neurons as well as the Cha-Tan neurons. Based on an rdl-Gal4 line, the ionotropic GABAA receptor subunit RDL may be expressed by L4 neurons and a type of tangential neuron (rdl-Tan). Strong vGluT immunoreactivity was detected in α-processes of amacrine neurons and possibly in the large monopolar neurons L1 and L2. These neurons also express glutamate-like immunoreactivity. However, antisera to ionotropic and metabotropic glutamate receptors did not produce distinct immunosignals in the lamina. In summary, this paper describes novel features of two distinct types of tangential neurons in the Drosophila lamina and assigns putative neurotransmitters and some receptors to a few identified neuron types
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