gebhart/patrepeval huggingface dataset:
Catheter segmentation in X-ray fluoroscopy using synthetic data and transfer learning with light U-nets (2020)

Background and objectivesAutomated segmentation and tracking of surgical instruments and catheters under X-ray fluoroscopy hold the potential for enhanced image guidance in catheter-based endovascular procedures. This article presents a novel method for real-time segmentation of catheters and guidewires in 2d X-ray images. We employ Convolutional Neural Networks (CNNs) and propose a transfer learning approach, using synthetic fluoroscopic images, to develop a lightweight version of the U-Net architecture. Our strategy, requiring a small amount of manually annotated data, streamlines the training process and results in a U-Net model, which achieves comparable performance to the state-of-the-art segmentation, with a decreased number of trainable parameters. MethodsThe proposed transfer learning approach exploits high-fidelity synthetic images generated from real fluroscopic backgrounds. We implement a two-stage process, initial end-to-end training and fine-tuning, to develop two versions of our model, using synthetic and phantom fluoroscopic images independently. A small number of manually annotated in-vivo images is employed to fine-tune the deepest 7 layers of the U-Net architecture, producing a network specialized for pixel-wise catheter/guidewire segmentation. The network takes as input a single grayscale image and outputs the segmentation result as a binary mask against the background. ResultsEvaluation is carried out with images from in-vivo fluoroscopic video sequences from six endovascular procedures, with different surgical setups. We validate the effectiveness of developing the U-Net models using synthetic data, in tests where fine-tuning and testing in-vivo takes place both by dividing data from all procedures into independent fine-tuning/testing subsets as well as by using different in-vivo sequences. Accurate catheter/guidewire segmentation (average Dice coefficient of ~ 0.55, ~ 0.26 and ~ 0.17) is obtained with both U-Net models. Compared to the state-of-the-art CNN models, the proposed U-Net achieves comparable performance ( ± 5% average Dice coefficients) in terms of segmentation accuracy, while yielding a 84% reduction of the testing time. This adds flexibility for real-time operation and makes our network adaptable to increased input resolution. ConclusionsThis work presents a new approach in the development of CNN models for pixel-wise segmentation of surgical catheters in X-ray fluoroscopy, exploiting synthetic images and transfer learning. Our methodology reduces the need for manually annotating large volumes of data for training. This represents an important advantage, given that manual pixel-wise annotations is a key bottleneck in developing CNN segmentation models. Combined with a simplified U-Net model, our work yields significant advantages compared to current state-of-the-art solutions.
Seed Biology of Ten Common Roadside Sri Lankan Weed Species (2020)

Weeds are undesirable in habitats where they grow and cause negative economic and environmental impacts. Understanding in weed seed germination is important to deploy control measures. This study was conducted to evaluate the effect of seed dormancy, smoke, KAR1, salinity and pH on germination of ten common roadside weed species in Sri Lanka. Freshly collected seeds of ten weed species were subjected to five treatments vis, (1) 0 and 500 ppm GA3; (2) Smoke solutions of 0%, 5%, 25%, 50%, 75%, and 100% strength; (3) 0 nM, 10 nM, 100 nM and 1 μM KAR1 solutions; (4) 0 nM, 25 mM, 50 mM, 75 mM, 100 mM, and 200 mM NaCl solutions; and (5) 4,5,6,7,8,9 and 10 pH buffer solutions. All the treatments were applied on 100 seeds (five replicates, 20 seeds each) and incubated at 25° C under 12/12 hrs light/dark for 4 weeks. Final germination percentages were calculated. Seeds of Bidens pilosa, Mikania micrantha, Rivina humilis, Tridax procumbens, and Vernonia cinerea were identified as non-dormant (germination>90%) and seeds of Ageratum conyzoides, Hyptis capitata, Oldenlandia herbacea, Ocimum tenuiflorum and Spilanthes iabadicensis were identified as dormant (germination 50% germination. R. humilis exhibited a wide range of pH tolerance (pH 5-8) with >50% germination. Seed dormancy of four species were broken by GA3 and KAR1 treatments indicating physiological seed dormancy (PD). Due to unresponsiveness to dormancy breaking treatments, it can be assumed that seed of O. tenuiflorum possess deep-PD. The study confirmed that responsiveness to KAR1, smoke, salinity and pH is species specific and seed dormancy may lead to the formation of persistent soil weed seed banks. These traits may facilitate the weed seeds to compete with other species and dominate the vegetation.Keywords: Karrikinolide (KAR1), pH, Smoke water, Salinity, Weed species
Topochemical Reactions in Langmuir-Blodgett Multilayers (1981)

Abstract The topochemical polymerization of diacetylenes and.the dimerization of cinnamic acid derivatives have been studied in Langmuir-Blodgett-multilayers. The resulting polymer films are of controlled thickness and morphology and exhibit excellent stability. Structure, morphology and phase changes occuring in monomer and polymer films have been investigated using spectroscopic methods, electron and x-ray diffraction. Possible applications of the polymer films are discussed.
<title>Effect of spatial behavior of scatter on 3D PET</title> (1997)

In 3D positron emission tomography (PET), all the coincidence events can be collected to increase the sensitivity of signal detection. However, the sensitivity increase results in the enlargement of scatter fraction which degrades image quality. For improving the accuracy of PET images, an effective scatter correction technique is necessary. In this paper, Monte Carlo simulations were done according to the system configuration of the animal PET design at the Institute of Nuclear Energy Research. From the simulation data we could understand what the scatter effect of our planned system will be. The convolution-subtraction method was chosen to correct for the scatter. A new approach to determine the scatter kernel function which could do better job on scatter correction will be presented.
Spline subdivision schemes for compact sets with metric averages (2001)

Abstract. Attempts at extending spline subdivision schemes to operate on compact sets are reviewed. The aim is to develop a procedure for ap-proximating a set-valued function with compact images from a finite set of its samples. This is motivated by the problem of reconstructing a 3D object from a finite set of its parallel cross sections. The first attempt is limited to the case of convex sets, where the Minkowski sum of sets is successfully ap-plied to replace addition of scalars. Since for nonconvex sets the Minkowski sum is too big and there is no approximation result as in the case of convex sets, a binary operation, called metric average, is used instead. With the metric average, spline subdivision schemes constitute approximating opera-tors for set-valued functions which are Lipschitz continuous in the Hausdorff metric. Yet this result is not completely satisfactory, since 3D objects are not continuous in the Hausdorff metric near points of change of topology, and a special treatment near such points has yet to be designed.
The next big step in digital transformation (2018)

Fabio Mielli looks at blockchain technology - is it the step in the digital transformation of mining?
Efficient triangulation-based pathfinding (2006)

In this paper we present a method for abstracting an environ-ment represented using constrained Delaunay triangulations in a way that significantly reduces pathfinding search effort, as well as better representing the basic structure of the envi-ronment. The techniques shown here are ideal for objects of varying sizes and environments that are not axis-aligned or that contain many dead-ends, long corridors, or jagged walls that complicate other search techniques. In fact, the abstrac-tion simplifies pathfinding to deciding to which side of each obstacle to go. This technique is suited to real-time computa-tion both because of its speed and because it lends itself to an anytime algorithm, allowing it to work when varying amounts of resources are assigned to pathfinding. We test search algo-rithms running on both the base triangulation (Triangulation A * – TA*) and our abstraction (Triangulation Reduction A* – TRA*) against A * and PRA * on grid-based maps from the commercial games Baldur’s Gate and WarCraft III. We find that in these cases almost all paths are found much faster us-ing TA*, and more so using TRA*.
Urine Electrolytes and Osmolality: When and How to Use Them (1990)

The purpose of this review is to provide an update on the use of the urine electrolyte and osmolality measurements in patients with disorders of fluid, electrolytes, and/or acid-base metabolism. It is critical to appreciate that there are no 'normal values' for these parameters, only 'expected values' relative to clinical situations. Pitfalls in the interpretation of each electrolyte in the urine are also provided. To detect a mild to moderate degree of reduction of the 'effective' intravascular volume, both urine sodium (Na) and chloride (Cl) concentrations should be measured. Pitfalls in this assessment are abnormal renal and adrenal function and the use of diuretics. Insights into the etiology of the low 'effective' intravascular volume can be deduced by comparing the urine Na, potassium (K), and Cl concentrations. The urine net charge (Cl vs. Na + K) is the most reliable way to estimate the urine ammonium concentration short of its direct measurement, an assay that is not provided by most laboratories. This measurement is important in the differential diagnosis of hyperchloremic metabolic acidosis. To examine the renal response to hypokalemia or hyperkalemia, the two components of K excretion (K secretion and urine flow rate) should be examined separately. The former is evaluated using the transtubular K, concentration gradient. The urine osmolality is used to assess antidiuretic hormone action and the osmolality of the renal medulla and to determine the etiology of polyuria and/or hypernatremia. The urine osmolality can also be used to assess the ammonium concentration, using the urine osmolal gap, and to detect unusual urine osmoles.
Low-temperature specific heat of structural and orientational glasses of simple alcohols (2003)

In this work, we review, extend and discuss low-temperature specific-heat experiments, that we have conducted on different molecular (hydrogen-bonded) solids both in crystalline and glassy (either amorphous or orientationally disordered) phases. In particular, we have measured the low-temperature specific heat Cp for a set of simple, well known alcohols: glycerol, propanol and ethanol. For glycerol, we have prepared and measured Cp of both glass and crystal phases down to 0.5 K. The same has been done for propanol, in this case comparing the strikingly different values observed for the two chemical isomers, 1-propanol and 2-propanol. Moreover, ethanol exhibits a very interesting polymorphism presenting three different solid phases at low temperature: a fully ordered (monoclinic) crystal, an orientationally disordered (cubic) crystal or 'orientational glass' and the ordinary structural (amorphous) glass. By measuring and comparing the low-temperature specific heat of the three phases, in the boson peak range 2–10 K as well as in the tunnelling-state range below 1 K, we provide a quantitative confirmation that 'glassy behaviour', either concerning low-temperature properties or the glass-transition phenomenon itself, is not directly related to the lack of long-range crystalline order occurring in amorphous solids.
DETROIT FREEWAY CORRIDOR ITS EVALUATION (2001)

This study evaluated the impacts of the Michigan Department of Transportation's Intelligent Transportation Systems (ITS) on congestion in the John C. Lodge corridor of Detroit. The ITS systems deployed included Internet-based pre-trip information, highway advisory radio (HAR), ramp metering, and variable message signs. The analysis was performed primarily using a simulation modeling approached. In addition, the study evaluated the impacts of a potential future policy and operational changes, including arterial signal coordination, accident-responsive signal coordination, and ramp metering modifications. The study also addressed a second issue, that of commuters' perceived preference for freeway routes through the Lodge corridor in the presence of shorter, time-based arterial routes also known as freeway bias.
Phenidone and Hydroxyurea Reduce Sulfur Mustard-Increased Proteolysis in Hairless Guinea Pig Skin (1995)

Increased proteolytic activity at the dermal-epidermal junction is postulated as being involved in sulfur-mustard-induced cutaneous injury. Homogenates of skin punch biopsy specimens from the skin of hairless guinea pig at 6, 9, 12, and 24 h after a 7 min vapor cup exposure to sulfur mustard (HD) demonstrated enhanced proteolytic activity. Homogenates from the biopsy specimens of exposed animals produced from 3 to 10 times the hydrolysis of the chromogenic peptide substrate Chromzym TH (tosyl-gly-pro-arg-p-nitranilide) and human elastase substrate N-methoxysuccinyl-ala-ala-pro-val-p-nitranilide than did the homogenates from control samples. In this study HD-increased proteolysis of the TH substrate by extracts of hairless guinea pig skin biopsies was nearly eliminated by systemic treatment with hydroxyurea and greatly reduced by topical application of the anti-inflammatory compound phenidone. Compounds that reduce HD-increased proteolytic activity, such as phenidone and hydroxyurea, can serve as probes to examine the role of proteolysis in HD-induced pathology. HD-increased proteolysis provides a biochemical correlate for investigating cutaneous exposure to HD. Increased proteolysis may therefore serve as a biomarker for HD-induced pathology that might be used as an index of efficacy for potential treatment compounds.
Comparative study of antibacterial properties of polystyrene films with TiOx and Cu nanoparticles fabricated using cluster beam technique (2018)

<b>Background:</b> Antibacterial materials are of high importance for medicine, and for the production and conservation of food. Among these materials, polymer films with metal nanoparticles (NPs) are of considerable interest for many practical applications. <b>Results:</b> The paper describes a novel approach for the formation of bactericidal polymer thin films (polystyrene in this case), produced by spin-coating, with Ti and Cu NPs deposited from cluster beams. Ti NPs are treated in three different ways in order to study different approaches for oxidation and, thus, efficiency in formation of the particles with semiconducting properties required for the catalytic formation of reactive oxygen species. Cu NPs are used as deposited. Partial NP embedding into polystyrene is realised in a controllable manner using thermal annealing in order to improve surface adhesion and make the particles resistant against wash-out. The formed composite films with TiO <i><sub>x</sub></i> and Cu species are tested as bactericidal media using <i>E.coli</i> bacteria as model microorganisms. <b>Conclusion:</b> The obtained results show considerable efficiency in destroying the bacteria and a good possibility of multiple re-use of the same composite films making the suggested approach attractive for the cases requiring reusable polymer-based antibacterial media.
A New Member of Gamma-Conotoxin Family Isolated from Conus princeps Displays a Novel Molecular Target (2016)

A novel conotoxin, named as PiVIIA, was isolated from the venom of Conus princeps, a marine predatory cone snail collected in the Pacific Southern Coast of Mexico. Chymotryptic digest of the S-alkylated peptide in combination with liquid chromatography coupled to tandem mass spectrometry, were used to define the sequencing of this peptide. Eleven N-terminal amino acids were verified by automated Edman degradation. PiVIIA is a 25-mer peptide (CDAOTHYCTNYWγCCSGYCγHSHCW) with six cysteine residues forming three disulphide bonds, a hydroxyproline (O) and two gamma carboxyglutamic acid (γ) residues. Based on the arrangement of six Cys residues (C-C-CC-C-C), this conotoxin might belong to the O2-superfamily. Moreover, PiVIIA has a conserved motif (-γCCS-) that characterizes γ-conotoxins from molluscivorous Conus. Peptide PiVIIA has 45% sequence identity with γ-PnVIIA-the prototype of this family. Biological activity of PiVIIA was assessed by voltage-clamp recording in rat dorsal root ganglion neurons. Perfusion of PiVIIA in the µM range produces a significant increase in the Ca(2+) currents, without significantly modifying the Na⁺, K⁺ or proton-gated acid sensing ionic currents. These results indicate that PiVIIA is a new conotoxin whose activity deserves further studies to define its potential use as a positive modulator of neuronal activity.
Electrochemical conversion of fatty acids (2011)

Abstract Electrochemical conversions combine an electron transfer with a chemical reaction, which allows conversions that are not available in non‐electrochemical reactions. Electrochemical conversions usually need fewer steps, produce less waste, provide a cheaper reagent, require less auxiliaries, and allow often an easier scale‐up than non‐electrochemical syntheses. In addition, they can be conducted at ambient temperature and pressure. All these qualities agree well with the rules of green chemistry. Electroactive sites for fatty acids are the carboxyl group, the CC double bond and the activated CH bond. The deprotonated carboxyl group is anodically decarboxylated to afford an alkyl radical. The radical can couple or add to a CC double bond. Radical coupling provides diesters, pheromones, or C‐glycosides. At the anode the double bond can be substituted in allylic position, add two nucleophiles or can be cleaved. Cathodic reduction of fatty acids with an enone group affords dimer fatty acids in a hydrodimerization. Non‐activated CH bonds in fatty acids can be oxygenated at the anode; the conversion occurs preferentially at the remote CH bonds.
Prices of Single Family Homes Since 1970: New Indexes for Four Cities (1987)

This paper uses data on nearly a million homes sold in four metropolitan areas -- Atlanta, Chicago, Dallas and San Francisco -- to construct quarterly indexes of existing home prices between 1970 and 1986. We propose and apply a new method of constructing such indexes which we call the method of constructing such indexes which we call the weighted repeat sales method (WRS). We believe the results give an accurate picture of the actual rate of appreciation in home prices in the four cities. The paper explains the construction of the index, discusses the results and compares them with the National Association of Realtors data on the median price of existing single family homes for the period 1981-1986.
1-W green generation by frequency-doubling of a diode end-pumped Nd:GdVO/sub 4/ laser in a bulk periodically poled MgO:LiNbO/sub 3/ at room temperature (2004)

1.38 W continuous-wave power at 531 nm with 19.6% internal conversion efficiency is obtained at room temperature by single-pass extracavity frequency doubling of a Nd:GdVO/sub 4/ laser through a 2-mm-thick, 25-mm-long periodically polled MgO:LiNbO/sub 3/.
Pavement Subgrade Stabilization Using Polymers: Characterization and Performance (2012)

This paper reports a laboratory investigation aimed at evaluating the potential of polymer binders to stabilize pavement subgrades in Qatar. The conclusions regarding the impact of the polymer stabilizers are based on comparisons with selected physical, chemical, mechanical, and microstructural properties of natural Qatari subgrade soil and soils stabilized with the traditional standard, portland cement (PC). The results demonstrate that the polymer binders modify the Qatari subgrade soils resulting in more favorable engineering properties: for example, the compressive strengths of the polymer-stabilized soils are superior to those of the unstabilized soils and those stabilized using PC. The mechanical properties of the stabilized and unstabilized soils were incorporated in the analysis of asphalt pavement sections using the state-of-the-art protocol for pavement design and analysis. Results of the analysis further demonstrated the benefits of using stabilized subgrade soils in improving pavement performance. Of particular practical importance is that polymer subgrade stabilization significantly reduces subgrade rutting. Consequently, polymer subgrade stabilization is a key consideration for perpetual pavements, especially considering the extremely high truck traffic in Qatar. Although the work reported in this paper was carried out with Qatari soil, the results are expected to be relevant to other types of soil and weather conditions experienced throughout the Middle East and in similar climates throughout the world.
Activation of ERK signaling upon alternative protease nexin‐1 internalization mediated by syndecan‐1 (2006)

Protease nexin-1 (PN-1), an inhibitor of serine proteases, contributes to tissue homeostasis and influences the behavior of some tumor cells. The internalization of PN-1 protease complexes is considered to be mediated by the low-density lipoprotein receptor related protein 1 (LRP1). In this study, both wild-type and LRP1-/- mouse embryonic fibroblasts (MEF) were shown to internalize PN-1. Receptor associated protein (RAP) interfered with PN-1 uptake only in wild-type MEF cells, indicating that another receptor mediates PN-1 uptake in the absence of LRP1. In LRP1-/- MEF cells, inhibitor sensitivity and kinetic values (t(1/2) at 45 min) of PN-1 uptake showed a similarity to syndecan-1-mediated endocytosis. In these cells, PN-1 uptake was increased by overexpression of full-length syndecan-1 and decreased by RNA interference targeting this proteoglycan. Most important, in contrast to PKA activation known to be triggered by LRP1-mediated internalization, our study shows that syndecan-1-mediated internalization of PN-1 stimulated the Ras-ERK signaling pathway.
Pore Sizes in Hydrated Dextran Microspheres (2000)

The average pore size of hydrated dextran microspheres is derived from rheological and protein release data. The microspheres were prepared by cross-linking an aqueous solution of methacrylated dextran emulsified in a continuous poly(ethylene glycol) phase. The rheological data were obtained using a novel micromanipulation technique, which enables the compression of a single microsphere. The so obtained pseudoelasticity moduli of the microspheres were derived from these compression data and corresponded well with the elasticity moduli of macroscopic hydrogels of the same composition, as determined with dynamic mechanical analysis. The modulus increased with decreasing water contents of the microspheres and with increasing degrees of methacrylate substitution of the dextran used. Furthermore, the average pore sizes calculated from the pseudoelasticity moduli were in good agreement with the pore sizes derived from protein release data. In conclusion, this study shows that micromanipulation provides insight into the average pore sizes of dextran microspheres, which is an important characteristic that will modulate the release of encapsulated proteins.
Waveguide avalanche photodiode operating at 1.55 μm with a gain-bandwidth product of 320 GHz (2001)

An In/sub 0.52/Al/sub 0.48/As-In/sub 0.53/Ga/sub 0.47/As waveguide avalanche photodiode with a record gain-bandwidth product of over 320 GHz has been demonstrated. A bandwidth of 28 GHz was achieved at low gains with low excess noise and a quantum efficiency of 16% at 1.55 μm.