We demonstrate a smartphone based spectrometer design that is standalone and supported on a wireless platform. The device is inherently low-cost and the power consumption is minimal making it ...portable to carry out a range of studies in the field. All essential components of the device like the light source, spectrometer, filters, microcontroller and wireless circuits have been assembled in a housing of dimensions 88 mm × 37 mm × 22 mm and the entire device weighs 48 g. The resolution of the spectrometer is 15 nm, delivering accurate and repeatable measurements. The device has a dedicated app interface on the smartphone to communicate, receive, plot and analyze spectral data. The performance of the smartphone spectrometer is comparable to existing bench-top spectrometers in terms of stability and wavelength resolution. Validations of the device were carried out by demonstrating non-destructive ripeness testing in fruit samples. Ultra-Violet (UV) fluorescence from Chlorophyll present in the skin was measured across various apple varieties during the ripening process and correlated with destructive firmness tests. A satisfactory agreement was observed between ripeness and fluorescence signals. This demonstration is a step towards possible consumer, bio-sensing and diagnostic applications that can be carried out in a rapid manner.
We demonstrate a fast and cost-effective technique to perform three dimensional (3D) scanning and replication of large paleontological specimens, in this case the entire skull of a Tyrannosaurus rex ...(T.rex) with a volume in the range of 2 m3. The technique involves time-of-flight (TOF) depth sensing using the Kinect scanning module commonly used in gesture recognition in gaming. Raw data from the Kinect sensor was captured using open source software and the reconstruction was done rapidly making this a viable method that can be adopted by museums and researchers in paleontology. The current method has the advantage of being low-cost as compared to industrial scanners and photogrammetric methods but also of accurately scanning a substantial volume range which is well suited for large specimens. The depth resolution from the Kinect sensor was measured to be around 0.6 mm which is ideal for scanning large specimens with reasonable structural detail. We demonstrate the efficacy of this method on the skull of FMNH PR 2081, also known as SUE, a near complete T.rex at the Field Museum of Natural History.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Many 'non-enveloped' viruses, including hepatitis A virus (HAV), are released non-lytically from infected cells as infectious, quasi-enveloped virions cloaked in host membranes. Quasi-enveloped HAV ...(eHAV) mediates stealthy cell-to-cell spread within the liver, whereas stable naked virions shed in feces are optimized for environmental transmission. eHAV lacks virus-encoded surface proteins, and how it enters cells is unknown. We show both virion types enter by clathrin- and dynamin-dependent endocytosis, facilitated by integrin β
, and traffic through early and late endosomes. Uncoating of naked virions occurs in late endosomes, whereas eHAV undergoes ALIX-dependent trafficking to lysosomes where the quasi-envelope is enzymatically degraded and uncoating ensues coincident with breaching of endolysosomal membranes. Neither virion requires PLA2G16, a phospholipase essential for entry of other picornaviruses. Thus naked and quasi-enveloped virions enter via similar endocytic pathways, but uncoat in different compartments and release their genomes to the cytosol in a manner mechanistically distinct from other
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The analysis and identification of different attributes of produce such as taxonomy, vendor, and organic nature is vital to verifying product authenticity in a distribution network. Though a variety ...of analysis techniques have been studied in the past, we present a novel data-centric approach to classifying produce attributes. We employed visible and near infrared (NIR) spectroscopy on over 75,000 samples across several fruit and vegetable varieties. This yielded 0.90-0.98 and 0.98-0.99 classification accuracies for taxonomy and farmer classes, respectively. The most significant factors in the visible spectrum were variations in the produce color due to chlorophyll and anthocyanins. In the infrared spectrum, we observed that the varying water and sugar content levels were critical to obtaining high classification accuracies. High quality spectral data along with an optimal tuning of hyperparameters in the support vector machine (SVM) was also key to achieving high classification accuracies. In addition to demonstrating exceptional accuracies on test data, we explored insights behind the classifications, and identified the highest performing approaches using cross validation. We presented data collection guidelines, experimental design parameters, and machine learning optimization parameters for the replication of studies involving large sample sizes.
The machining of nickel-based super alloys is challenging, owing to the generation of high cutting temperatures, as well as difficulty in maintaining dimensional accuracy and minimizing surface ...roughness, which compels the use of cutting fluids for reducing these issues due to efficient cooling/lubrication strategies. The present work investigates the comparative performance of four cooling/lubrication techniques: dry cutting, wet, minimum quantity lubricant (MQL) and compressed-air modes in turning Nitronic 60 steel using a new-generation SiAlON ceramic inserts. Several machinability parameters were analyzed for performance evaluation. For this purpose, 16 cycles of turning trials were performed based on Taguchi's L
orthogonal array experimental design by varying cutting conditions and lubrication modes. MQL exhibits beneficial effects as compared to the other lubrication conditions concerning low cutting force, improved surface finish, decreased cutting temperature, longer tool life, and lower white layer thickness on machined surface. Burr formation on the saw-tooth chip surface, as well as friction, greatly influenced the tool flank wear due to improper cooling and poor lubrication approach in dry, wet, and compressed-air-cooled machining environments in comparison to MQL-machining. From an economical perspective, the tool life in MQL machining improved by 11%, 72%, and 138% in the comparison with flooded, compressed-air, and dry conditions, respectively. The results of the study demonstrate that using the MQL system can help with heat extraction capability, and provide some promising outcomes.
A light harvesting device geometry is implemented for polymer solar cells that retain efficiency when the device area is scaled up. Patterning devices and incorporating suitable fluorescent dye doped ...polymers in the spaces between the patterns leads to 12% efficiency enhancement. Vacuum free deposition of electrodes is carried out using meltable alloys giving rise to device efficiency of 6%. The fluorescent layer along with the electrode serves as an active encapsulant leading to improved device stability.
The alloy steels commonly used for manufacturing of moulds and dies are the metals under hard-to-cut category because of their hardness above 50 HRC in order to attain high performance. In general, ...ceramic and CBN tools are used for machining hardened steel but its higher cost makes the use for limited applications. However, the usefulness of carbide tool with selective coatings is the best substitute having comparable tool life, and in terms of cost is approximately one-third of ceramic tool while one-tenth of CBN tool. This study addresses the comparative machining performance evaluation and machinability investigation between newly developed second-generation supernitride nanocomposite HSN
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-TiAlxN coating with conventional TiCN coated carbide insert in turning of hardened AISI D6 die steel (65 HRC) under dry environment. Several machinability characteristics such as cutting temperature, tool (flank & crater) wear, surface finish, chip morphology, and principal cutting force were analyzed for machining performance evaluation under varying cutting variables (depth of cut, feed, speed). Finally, considering the motivational idea of “Go Green-Think Green-Act Green”, a unique novel approach has been proposed concerning economic evaluation and sustainability assessment in hard turning. Among the tools used, HSN
2
-TiAlxN coated carbide tool for hard turning application promises, and excellent machinability performances in terms of (i) longer tool life due to lower value of flank & crater wears, (ii) minimum cutting force, (iii) improved surface finish, (iv) lower cutting temperature, and (v) considerable economic advantages as the production cost is reduced by 12%. With the increase in feed, the orientations of all the considered machinability characteristics show an increasing trend. The development of serrated type saw tooth chips was confirmed by chip morphology. In comparison to wet condition, machining in absence of cutting fluid provides an environment friendliness, techno-economical feasible approach to improve sustainability.
Hepatotropic viruses are important causes of human disease, but the intrahepatic immune response to hepatitis viruses is poorly understood because of a lack of tractable smallanimal models. We ...describe a murine model of hepatitis A virus (HAV) infection that recapitulates critical features of type A hepatitis in humans. We demonstrate that the capacity of HAV to evade MAVS-mediated type I interferon responses defines its host species range. HAV-induced liver injury was associated with interferon-independent intrinsic hepatocellular apoptosis and hepatic inflammation that unexpectedly resulted from MAVS and IRF3/7 signaling. This murine model thus reveals a previously undefined link between innate immune responses to virus infection and acute liver injury, providing a new paradigm for viral pathogenesis in the liver.
Current models of cell-intrinsic immunity to RNA viruses centre on virus-triggered inducible antiviral responses initiated by RIG-I-like receptors or Toll-like receptors that sense ...pathogen-associated molecular patterns, and signal downstream through interferon regulatory factors (IRFs), transcription factors that induce synthesis of type I and type III interferons
. RNA viruses have evolved sophisticated strategies to disrupt these signalling pathways and evade elimination by cells, attesting to their importance
. Less attention has been paid to how IRFs maintain basal levels of protection against viruses. Here, we depleted antiviral factors linked to RIG-I-like receptor and Toll-like receptor signalling to map critical host pathways restricting positive-strand RNA virus replication in immortalized hepatocytes and identified an unexpected role for IRF1. We show that constitutively expressed IRF1 acts independently of mitochondrial antiviral signalling (MAVS) protein, IRF3 and signal transducer and activator of transcription 1 (STAT1)-dependent signalling to provide intrinsic antiviral protection in actinomycin D-treated cells. IRF1 localizes to the nucleus, where it maintains the basal transcription of a suite of antiviral genes that protect against multiple pathogenic RNA viruses, including hepatitis A and C viruses, dengue virus and Zika virus. Our findings reveal an unappreciated layer of hepatocyte-intrinsic immunity to these positive-strand RNA viruses and identify previously unrecognized antiviral effector genes.
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