111 research outputs found

    ChronoMIDā€”Cross-modal neural networks for 3-D temporal medical imaging data

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    ChronoMIDā€”neural networks for temporally-varying, hence Chrono, Medical Imaging Dataā€”makes the novel application of cross-modal convolutional neural networks (X-CNNs) to the medical domain. In this paper, we present multiple approaches for incorporating temporal information into X-CNNs and compare their performance in a case study on the classification of abnormal bone remodelling in mice. Previous work developing medical models has predominantly focused on either spatial or temporal aspects, but rarely both. Our models seek to unify these complementary sources of information and derive insights in a bottom-up, data-driven approach. As with many medical datasets, the case study herein exhibits deep rather than wide data; we apply various techniques, including extensive regularisation, to account for this. After training on a balanced set of approximately 70000 images, two of the modelsā€”those using difference maps from known reference pointsā€”outperformed a state-of-the-art convolutional neural network baseline by over 30pp (> 99% vs. 68.26%) on an unseen, balanced validation set comprising around 20000 images. These models are expected to perform well with sparse data sets based on both previous findings with X-CNNs and the representations of time used, which permit arbitrarily large and irregular gaps between data points. Our results highlight the importance of identifying a suitable description of time for a problem domain, as unsuitable descriptors may not only fail to improve a model, they may in fact confound it

    Longevity, body dimension and reproductive mode drive differences in aquatic versus terrestrial life-history strategies

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    1. Aquatic and terrestrial environments display stark differences in key environmental factors and phylogenetic composition but their consequences for the evolution of species' life-history strategies remain poorly understood. 2. Here, we examine whether and how life-history strategies vary between terrestrial and aquatic species. We use demographic information for 685 terrestrial and 122 aquatic animal and plant species to estimate key life-history traits. We then use phylogenetically corrected least squares regression to explore potential differences in trade-offs between life-history traits between both environments. We contrast life-history strategies of aquatic versus terrestrial species in a principal component analysis while accounting for body dimensions and phylogenetic relationships. 3. Our results show that the same trade-offs structure terrestrial and aquatic life histories, resulting in two dominant axes of variation that describe species' pace of life and reproductive strategies. Terrestrial plants display a large diversity of strategies, including the longest-lived species in this study. Aquatic animals exhibit higher reproductive frequency than terrestrial animals. When correcting for body size, mobile and sessile terrestrial organisms show slower paces of life than aquatic ones. 4. Aquatic and terrestrial species are ruled by the same life-history trade-offs, but have evolved different strategies, likely due to distinct environmental selective pressures. Such contrasting life-history strategies have important consequences for the conservation and management of aquatic and terrestrial species

    Promene polipeptidne strukture sojinog proteinskog izolata pri termičkoj inaktivaciji antinutritivnih komponenti

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    The change of polypeptide composition of soybean isolates, prepared from samples treated by autoclaving in the aim of trypsin inhibitors inactivation (0.5 bar; 5,10 and 15 min.) was investigated. By densitometric analysis of SDS-PAGE-gels, the composition of soybean isolated protein was determined. According to our results, glycinin showed the highest content among proteins of soybean isolates. Depending on duration of soybeans heating, the percentage of glycinin in resulting isolate was 47.14-53.08%. High content of acidic (30.02-30.98%) and basic (15.12-18.24%) polypeptides of glycinin was registered. High content of a-subunit of P-conlycinin was determined (11.49-8.99%). The presence of Bowman-Birk TI as well as lypoxigenase, was not registered in any of protein isolates.Cilj ovog rada bio je da se ispita uticaj nadpritiska 0,5 bara, radne temperature 96Ā°C u trajanju od 5,10 i 15 minuta u autoklavu na promene polipeptidne strukture dobijenih proteinskih Izolata iz lomljenog sojinog zrna. Potvrđena je termostabilnost molekulaglicinina (47,14-53,08%), i manja stabilnost B-konglicinina (15,31-25,45%). Denzitomelrijska analiza SDS-elektroforegrama ukazuje na izraženu termostabilnost kiselih A1,2,4(27,50-26,31%) i baznih B1,2,3,4(18,24-15,12%) polipeptlda glicinina. Sadržaj a-polipeptida fikonglicinina pokazuje linearnu zavisnost od trajanja primenjenih tretmana (10,92-8,99%). Nakon ovih tretmana zapažena je smanjena tripsininhibitorska aktivnost (TIA), pri čemu je nosilac TIA Kunitz-ov TI (5,00-8,80%), dok je Bowman-Birk-ov inhibitor registrovan samo kod izolata iz netretiranog lomljenog sojinog zrna (3,92%)

    Antioxidant activity, the content of total phenols and flavonoids in the ethanol extracts of Mentha longifolia (L.) Hudson dried by the use of different techniques

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    In this study, we have examined the yield of extracted substances obtained by means of extraction using 70 % ethanol (v/v), the content of total phenols and flavonoids, as well as the antioxidant activity of the extracts obtained from the samples of the herbs dried by means of different techniques. Wild mint Mentha longifolia (L.) Hudson was dried naturally in a laboratory oven at a temperature of 45 Ā°C and in an absorptive low temperature condensation oven at 35Ā°C. The highest yield of extracts was obtained from the naturally dried herbs and the lowest from the herbs dried in the low temperature condensation drying oven. The content of total phenols and flavonoids was determined by spectrophotometric methods with an FC reagent and by the complexation reaction with aluminium-chloride, respectively. The extract of the naturally dried herbs had the highest overall content of phenols (113.8Ā±2.0 mg of gallic acid/g of the dry extract) and flavonoids (106.7Ā±0.3 mg of rutin/g of the dry extract). The highest antioxidant activity determined by the FRAP and DPPH assay was determined in the extracts obtained from naturally dried herbs (2.76Ā±0.15 mmol Fe2+/mg of the dry extract and EC50=0.022Ā±0.001 mg/ml), while the lowest was obtained from the extracts of herbs dried in the laboratory oven (1.13Ā±0.11 mmol Fe2+/mg of the dry extract and EC50=0.033Ā±0.001 mg/ml). The HPLC-DAD analysis result show that the greatest content of phenolic compounds show extract obtained from naturally dried plant material. The dominant phenolic component in the all extracts is Kaempferol 3-O-glucoside. The content of all phenolic compound strongly depend on the drying conditions

    Analysis of 4,4ā€²-bis(2,2ā€²diphenyl vinyl)-1,1ā€²- biphenyl using the atmospheric-pressure solids analysis probe for ionization

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    An Atmospheric pressure Solids Analysis Probe (ASAP) mass spectrometer are used for investigation the ionization mechanism and fragmentation pathways of 4,4ā€²-bis(2,2ā€²diphenyl vinyl)-1,1ā€²-biphenyl (DPVBi). DPVBi is material used in OLEDs (organic light-emitting diode). Results obtained indicate that by controlling ion source conditions it is possible to optimize forming of desired precursor ion, primarily radical cation and in less content protonated ion of DPVBi. The results presented illustrate the usefulness of ASAP MS in the characterization of DPVBi compounds

    Negative-Mode LDI-MS of corrosion products on the surface of AgCu-X (X- Zn, Pd, In) alloys

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    Copper-silver alloys have widely applied in many different areas such as information and communication technology, rail transportation, power transmission lines, microelectronics, machinery manufacturing, chemical processing industries, coinage, ornamental parts, etc [1, 2]. A group of ternary Ag-Cu alloys with different elements is used for binding different materials (brazing, fillers, and pastes). For example, Ag-Cu-Pd alloys are used in dentistry, as amalgams improvers or joint fillers for different dental materials [3]. Ternary AgCuIn alloy uses as a bonding metal layer; the use of AgCuIn as the bonding metal, greatly reduces the manufacturing costs of LED chip and helps to improve the life of the LED chip. Copper and its alloys belong to the group of semi-noble metals however they are not highly resistant to corrosion in some of the environments [4, 5]. Corrosion has particularly attracted attention due to the significant impact on the performance and reliability of this industrially important material group in their applications, as well as on the economy. Standard methods for characterization of corrosion films are: X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM) with Energy Dispersive Spectroscopy (EDS) [6, 7]. The positive mode laser desorption ionization (LDI) mass spectrometry method can be successfully applied to analyze the composition of the corrosion film. In our previous work, it has been shown that the amount of sample required for the LDI method is much smaller than the sample quantity required for the methods mentioned above [8]. The purpose of this work was to study the possibilities of direct analysis of the corrosion films formed on Ag60Cu26Zn14, Ag58.5Cu31.5Pd10, and Ag63Cu27In10 alloys using the negative mode laser desorption ionization (LDI) mass spectrometry method. The corrosion films of Ag60Cu26Zn14, Ag58.5Cu31.5Pd10, and Ag63Cu27In10 alloys were obtained after anodic potentiostatic polarization treatment (at +0.25 V for 5 min in 3.5% wt. NaCl solution). Preliminary results show that the negative mode LDI mass spectra measured from the corrosion film of these alloys contains same ionsAgCl2 - , AgCuCl3 - , CuCl2 - , Cu2Cl3 - , Cu3Cl4 - . This result suggested that main reactions are the formation of CuCl layer on the surface of the Cu rich metallurgical phase and formation of AgCl film on the surface of Ag rich metallurgical phase. ACKNOWLEDGEMENT: This work is the result of the Projects OI 172019 and TR 34033, funded by the Ministry of Education, Science and Technological Development of the Republic of Serbia.VII International School and Conference on Photonics : PHOTONICA2019 : Abstracts of Tutorial, Keynote, Invited Lectures, Progress Reports and Contributed Papers; August 26-30; Belgrad

    Degradation of thin 4,4ā€²-bis(2,2ā€²diphenyl vinyl)-1,1ā€²-biphenyl films by UV light

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    We studied degradation of 4,4ā€²-bis(2,2ā€²diphenyl vinyl)-1,1ā€²-biphenyl (DPVBi), well know OLED material. Thermally evaporated thin films of DPVBi were irradiated with UV light in ambient, vacuum and under different oxygen pressures. The cause of degradation is reaction between UV excited DPVBi molecules and oxygen, via formation of singlet oxygen or electron transfer from excited DPVBi to molecular oxygen. Reaction rates depend on oxygen concentration and UV light intensity. These reactions lead to formation of oxidized species as evidenced by ASAP and MALDI-TOF mass spectroscopy. Photoluminescence quenching has two parts. One part is reversible and may imply formation of charge transfer complexes and the other is irreversible, caused by formation of oxidized species. IR and absorption spectra are studied by Density Functional Theory and results compared with the experiment.SIXTEENTH ANNUAL CONFERENCE YUCOMAT 2014 Hunguest Hotel Sun Resort Herceg Novi, Montenegro, September 1-5, 201

    Prospective of the LDI MS to characterization the corrosion products of silver-copper alloys on an example of the Ag-Cu-X (X- Zn, Pd, In) system

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    This work presents the perspective of applying the laser desorption/ionization mass spectrometry (LDI MS) for characterization the anode film of the Ag60Cu26Zn14, Ag58.5Cu31.5Pd10, and Ag63Cu27In10 alloys (at high concentrations of chloride ions in solutions). The reference LDI mass spectra of anode films of pure Ag and Cu have been used for the identification of product corrosion. Knowing the clusters detected in the reference spectra lead to the facilitating identification of the LDI mass spectrum of the sample and reduces the analysis time. The LDI MS analysis of these alloys revealed that the predominant corrosion product are AgCl (from AgnCln+1āˆ’/+, nĀ =Ā 1ā€“3), and CuCl (from ā€œsuperhalogenā€ CumClnāˆ’ clusters, mĀ =Ā 1ā€“2, nĀ =Ā 2ā€“6); it also revealed Cu2(OH)3Cl (from Cu2(OH)(H2O)2+) and Cu2O (from Cu(H2O)+, Cu2O doped with chlorine). These results are in accordance with the X-ray diffraction and Raman analysis. The LDI MS spectra of alloys contain the additional peaks formed due to the mutual influences of different metals in the alloys (AgCuCl3āˆ’ (AgCl-CuCl2āˆ’), AgCu2Cl4āˆ’ (AgCl-CuCl-CuCl2āˆ’), and Ag2CuCl4āˆ’ (AgCl-AgCl-CuClāˆ’), which is consistent with the identified corrosion products. It should be noted that the LDI MS suggest the presence of CuCl2, which can be interpreted as the corrosion products retained in the porous films of alloys, and not detected by the other methods due to a small amount. The future theoretical and experimental studies of metal clusters, significant for metallurgy, can contribute that the LDI MS is becoming a powerful analytical tool for characterization the metal surfaces
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