gebhart/patrepeval huggingface dataset:
EM reconstruction algorithms for emission and transmission tomography. (1984)

Two proposed likelihood models for emission and transmission image reconstruction accurately incorporate the Poisson nature of photon counting noise and a number of other relevant physical features. As in most algebraic schemes, the region to be reconstructed is divided into small pixels. For each pixel a concentration or attenuation coefficient must be estimated. In the maximum likelihood approach these parameters are estimated by maximizing the likelihood (probability of the observations). EM algorithms are iterative techniques for finding maximum likelihood estimates. In this paper we discuss the general principles behind all EM algorithms and derive in detail the specific algorithms for emission and transmission tomography. The virtues of the EM algorithms include (a) accurate incorporation of a good physical model, (b) automatic inclusion of non-negativity constraints on all parameters, (c) an excellent measure of the quality of a reconstruction, and (d) global convergence to a single vector of parameter estimates. We discuss the specification of necessary physical features such as source and detector geometries. Actual reconstructions are deferred to a later time.
Memory management for scalable Web data servers (2002)

Popular Web sites are already experiencing very heavy loads, and these loads will only increase as the number of users accessing them grows. These loads create both CPU and I/O bottlenecks. One promising solution already being employed to eliminate the CPU bottleneck is to replace a single processor server with a cluster of servers. Our goal in this paper is to develop buffer management algorithms that exploit the aggregate memory capacity of the machines in such a server cluster to attack the I/O bottleneck. The key challenge in designing such buffer management algorithms turns out to be controlling data replication so as to achieve a good balance between intra-cluster network traffic and disk I/O. At one extreme, the straightforward application of client-server memory management techniques to this cluster architecture causes duplication in memory among the servers and this tends to reduce network traffic but increases disk I/O, whereas at the other extreme, eliminating all duplicates tends to increase network traffic while reducing disk I/O. Accordingly, we present a new algorithm, called Hybrid, that dynamically controls the amount of duplication. Through a detailed simulation, we show that, on workloads that are characteristic of those experienced by Web servers, the Hybrid algorithm correctly trades off intra-cluster network traffic and disk I/O to minimize average response time.
Removable biliary endoprosthesis (1983)

Removable biliary endoprosthesisJC Palmaz and EJ BurbigeAudio Available | Share
Cell Death Mechanisms Following Traumatic Brain Injury (2004)

Neuronal and glial cell death and traumatic axonal injury contribute to the overall pathology of traumatic brain injury (TBI) in both humans and animals. In both head-injured humans and following experimental brain injury, dying neural cells exhibit either an apoptotic or a necrotic morphology. Apoptotic and necrotic neurons have been identified within contusions in the acute post-traumatic period, and in regions remote from the site of impact in the days and weeks after trauma, while degenerating oligodendrocytes and astrocytes have been observed within injured white matter tracts. We review and compare the regional and temporal patterns of apoptotic and necrotic cell death following TBI and the possible mechanisms underlying trauma-induced cell death. While excitatory amino acids, increases in intracellular calcium and free radicals can all cause cells to undergo apoptosis, in vitro studies have determined that neural cells can undergo apoptosis via many other pathways. It is generally accepted that a shift in the balance between pro- and anti-apoptotic protein factors towards the expression of proteins that promote death may be one mechanism underlying apoptotic cell death. The effect of TBI on cellular expression of survival promoting-proteins such as Bcl-2, Bcl-xL, and extracellular signal-regulated kinases, and death-inducing proteins such as Bax, c-Jun N-terminal kinase, tumor-suppressor gene, p53, and the calpain and caspase families of proteases are reviewed. In light of pharmacologic strategies that have been devised to reduce the extent of apoptotic cell death in animal models of TBI, our review also considers whether apoptosis may serve a protective role in the injured brain. Together, these observations suggest that cell death mechanisms may be representative of a continuum between apoptotic and necrotic pathways.
Chemical Constitution, Electrochemical, Photographic and Allergenic Properties of p-Amino-N-dialkylanilines1 (1951)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemical Constitution, Electrochemical, Photographic and Allergenic Properties of p-Amino-N-dialkylanilines1R. L. Bent, J. C. Dessloch, F. C. Duennebier, D. W. Fassett, D. B. Glass, T. H. James, D. B. Julian, W. R. Ruby, J. M. Snell, J. H. Sterner, J. R. Thirtle, P. W. Vittum, and A. WeissbergerCite this: J. Am. Chem. Soc. 1951, 73, 7, 3100–3125Publication Date (Print):July 1, 1951Publication History Published online1 May 2002Published inissue 1 July 1951https://pubs.acs.org/doi/10.1021/ja01151a037https://doi.org/10.1021/ja01151a037research-articleACS PublicationsRequest reuse permissionsArticle Views618Altmetric-Citations72LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Improvements in Capacitance-Resistive Modeling and Optimization of Large Scale Reservoirs (2009)

Abstract Oil production strategies traditionally attempt to combine and balance complex geophysical, petrophysical, thermodynamic and economic factors to determine an optimal method to recover hydrocarbons from a given reservoir. Reservoir simulators have traditionally been too large and run times too long to allow for rigorous solution in conjunction with an optimization algorithm. It has also proven very difficult to marry an optimizer with the large set of nonlinear partial differential equations required for accurate reservoir simulation. A simple capacitance-resistive model that characterizes the connectivity between injection and production wells can determine an injection scheme that maximizes the value of the reservoir asset. Model parameters are identified using linear and nonlinear regression. The model is then used together with a nonlinear optimization algorithm to compute a set of future injection rates which maximize discounted net profit. Research previously conducted has shown that this simple dynamic model provides an excellent match to historic data. Based on a number of simulated and two actual fields, the optimal injection schemes based on the capacitance-resistive model yield a predicted increase in hydrocarbon recovery of up to 60% over the extrapolated historic decline. An advantage of using a simple model is its ability to describe large scale systems in a straightforward way with computation times that are short to moderate. However, applying the capacitance-resistive model to large reservoirs with many wells presents several new challenges. Reservoirs with hundreds of wells have longer production histories that often represent a variety of different reservoir conditions. New wells are created, wells are shut in for varying periods of time and production wells are converted to injection wells. Additionally, history matching large reservoirs by nonlinear regression is more likely to produce parameters that are statistically insignificant, resulting in a parameter dense model that does not accurately reflect the physical properties of the reservoir. Several modeling techniques and heuristics are presented that provide a simple, accurate reservoir model that can be used to optimize the value of the reservoir over future time periods.
In vivo Molecular Imaging of Cancer with a Quenching Near-Infrared Fluorescent Probe Using Conjugates of Monoclonal Antibodies and Indocyanine Green (2009)

Near-infrared (NIR) fluorophores have several advantages over visible fluorophores, including improved tissue penetration and lower autofluorescence; however, only indocyanine green (ICG) is clinically approved. Its use in molecular imaging probes is limited because it loses its fluorescence after protein binding. This property can be harnessed to create an activatable NIR probe. After cell binding and internalization, ICG dissociates from the targeting antibody, thus activating fluorescence. ICG was conjugated to the antibodies daclizumab (Dac), trastuzumab (Tra), or panitumumab (Pan). The conjugates had almost no fluorescence in PBS but became fluorescent after SDS and 2-mercaptoethanol, with a quenching capacity of 10-fold for 1:1 conjugates and 40- to 50-fold for 1:5 conjugates. In vitro microscopy showed activation within the endolysosomes in target cells. In vivo imaging in mice showed that CD25-expressing tumors were specifically visualized with Dac-ICG. Furthermore, tumors overexpressing HER1 and HER2 were successfully characterized in vivo by using Pan-ICG(1:5) and Tra-ICG(1:5), respectively. Thus, we have developed an activatable NIR optical probe that "switches on" only in target cells. Because both the antibody and the fluorophore are Food and Drug Administration approved, the likelihood of clinical translation is improved.
Effect of docetaxel with cisplatin or vinorelbine on lung cancer cell lines. (1999)

Docetaxel shows substantial activity against lung cancer. To find the optimal drug combination for docetaxel, we evaluated the effects of cisplatin, etoposide, mitomycin C, irinotecan, vindesine, and vinorelbine using three human lung cancer cell lines, ABC-1, EBC-1, and SBC-3. Drug cytotoxicity was determined by MTT assay. Tumor cells were incubated for 96 hours in the presence of docetaxel and each of the test drugs stated above. The combined drug interaction was evaluated by median-effect plot analysis and improved IC50-isobologram analysis. Both methods showed strong antagonism (subadditive or protective effect) between docetaxel and etoposide when tested on ABC-1 and EBC-1 cells. Docetaxel and cisplatin displayed additive effects on all cell lines tested, when evaluated by improved IC50-isobologram analysis. The combination of docetaxel and vinorelbine exerted synergistic effect on the growth inhibition of SBC-3 cells, which showed a wide range of fractional cytotoxicity when analyzed by median-effect plot and supraadditive when analyzed by improved IC50-isobologram. These observations suggest a possibility that docetaxel can be used in combination with vinorelbine or cisplatin in the treatment of lung cancer.
Intrinsic Physical Unclonable Functions in Field Programmable Gate Arrays (2007)

In today’s globalized economy, it has become standard business practice to include third party Intellectual Property (IP) into products. However, licensing IP to third parties forces IP vendors to ensure that they can generate revenue from their internally developed IP blocks. This is only guaranteed if designs are properly protected against theft, cloning, and grey market overproduction. In this paper, we describe a solution for the IP protection problem on Field Programmable Gate Arrays (FPGAs) based on the use of Physical Unclonable Functions (PUFs). Our solution includes optimizations at the protocol level, making the resulting protocols more efficient than previously proposed ones. In addition, we show how SRAM memory blocks present in current FPGAs can be used as a PUF. This leads to a solution which allows unique identification of FPGAs without requiring significant additional hardware resources, and to ensure code can only run on authorized platforms.
Isotachophoresis with ionic spacer and two-stage separation for high sensitivity DNA hybridization assay (2013)

We present an on-chip electrophoretic assay for rapid and high sensitivity nucleic acid (NA) detection. The assay uses isotachophoresis (ITP) to enhance NA hybridization and an ionic spacer molecule to subsequently separate reaction products. In the first stage, the probe and target focus and mix rapidly in free solution under ITP. The reaction mixture then enters a region containing a sieving matrix, which allows the spacer ion to overtake and separate the slower probe-target complex from free, unhybridized probes. This results in the formation of two focused ITP peaks corresponding to probe and probe-target complex signals. For a 149 nt DNA target, we achieve a 220 fM limit of detection (LOD) within 10 min, with a 3.5 decade dynamic range. This LOD constitutes a 12× improvement over previous ITP-based hybridization assays. The technique offers an alternative to traditional DNA hybridization assays, and can be multiplexed and extended to detect other biomolecules.
Oral Administration of Insulin as Poly(Vinyl Alcohol)-Gel Spheres in Diabetic Rats. (1996)

The oral administration of insulin in poly(vinyl alcohol)-gel spheres (PVA-GS), an oral dosage form with prolonged residence time in the ileum, was examined in streptozotocin-induced diabetic rats. Intragastric administration of PVA-GS containing insulin and a protease inhibitor, aprotinin or bacitracin, caused a significant and prolonged reduction of blood glucose levels, suggesting insulin absorption. The bioavailability of insulin estimated from the hypoglycemic effect was about 2% in the presence of either protease inhibitor. The release profiles of insulin and the protease inhibitors from the PVA-GS could be explained by Higuchi's plot, and the rates were similar to each other. The site dependency of insulin absorption in the intestinal tract was examined by an in situ loop method. Insulin absorption estimated by plasma insulin levels was larger in the ileum and the large intestine than in the jejunum. The prolonged residence time of PVA-GS in the absorption site, the lower intestine, and the synchronous release of insulin and the protease inhibitors from the PVA-GS are the two major explanations for the improved bioavailability of insulin administered as PVA-GS containing a protease inhibitor.
Inner Workings of Shrouded and Unshrouded Transonic Fan Blades (2008)

This paper reports on the numerical assessment of the differences in aerodynamic performance between part span shrouded and unshrouded fan blades generally found in the first stage of multistage fans in low bypass ratio aircraft engines. Rotor flow fields for both blade designs were investigated at two operating conditions using a three-dimensional viscous flow analysis. Although designed to the same radius ratio, aspect ratio, and solidity, the unshrouded fan rotor had a slightly increased tip speed (+3%) and somewhat lower pressure ratio (−3.2%) due to engine cycle requirements. Even when allowing for these small differences, the analysis reveals interesting differences in the level and in the radial distribution of efficiency between these two rotors. The reason for the improved performance of the shrouded rotor in part can be attributed to the shroud blocking off the radial migration of boundary layer fluid centrifuged from the hub on the suction side. As a result, the shock boundary layer interaction seems to be improved on the shrouded blade. At the cruise condition, the efficiency is the same for both rotors. The slightly better efficiency of the shrouded blade in the outer panel is nullified by the large efficiency penalty in the vicinity of the shroud. As there is no significant radial migration of fluid in the suction side boundary layer, as indicated by the analysis at this condition relative to the design speed case, the benefit due to the shroud is greatly reduced. At this speed and at lower speeds, the shroud becomes a net additional loss for the blade. Also of interest from the numerical results is the indication that significant blade ruggedization penalties to performance can be reduced in the case of the unshrouded blade through custom tailoring of its mean camber line.
Chemotactic migration of normal dermal fibroblasts towards epidermal growth factor and its modulation by platelet-derived growth factor and transforming growth factor-beta. (1990)

During the repair phase of wound healing, fibroblasts migrate to the site of injury where they proliferate and synthesize constituents of the extracellular matrix of connective tissue. Their activity is regulated by mediators originating from cells of the blood clotting and inflammatory stage such as platelet-derived growth factor, epidermal growth factor, transforming growth factor-beta and other cytokines. This communication shows that chemotactic migration of normal dermal fibroblasts is elicited by epidermal growth factor in vitro and that platelet-derived growth factor and transforming growth factor-beta can down-regulate this activity. This suggests that in vivo these growth factors are part of an intricate network which connects and coordinates proliferation, protein synthesis and chemotactic migration of fibroblasts.
Synthesis of δ‐stearolactone from oleic acid (2000)

Abstract δ‐Stearolactone was prepared from oleic acid using concentrated sulfuric acid under various conditions in the presence of polar, nonparticipating solvents. δ‐Stearolactone was formed in as high as 15∶1 ratios over the thermodynamic product, ψ‐lactone, in the presence of methylene chloride, 100% wt/vol, at room temperature with two equivalents of sulfuric acid for 24 h. This procedure is applicable to other olefinic fatty acids such as estolides and fatty acid methyl esters. Temperature plays a role in the regioselectivity of the cyclization for δ‐lactone, as lower temperatures (20°C) gave higher σ/ψ ratios. At higher temperatures (50°C) in the presence of sulfuric acid and methylene chloride the yield of lactone was 75% but with a σ/ψ ratio of only 0.3∶1. Cyclization of oleic acid to lactone also occurred with other acids. Oleic acid underwent reaction with perchloric acid, one equivalent, in the absence of solvent at 50°C, which yielded σ‐lactone in a modest yield with a 3.1 σ/ψ ratio. The same temperature effect was observed with perchloric acid that was observed in the case of sulfiric acid. Because σ‐stearolactone is much more reactive than the corresponding fatty acid, fatty acid ester, or ψ‐lactone, we believe that it will be a useful synthon for many new industrial products including new biodegradable detergents.
Mechanisms of Failure of Locked-Plate Fixation of the Proximal Humerus (2012)

Cancellous bone density and total cancellous screw depth penetration seem to be critical variables. Although the patients' bone density cannot be controlled, surgeons may decrease the risk of failure by maximizing the length of the screws within the cancellous bone. Analysis of microcrack formation revealed that failures begin at the midportion and tips of the inferior screws and at the bone-plate interface of the inferior screws.
Fluorescence of Eu2+-Activated Phases in Binary Alkaline Earth Orthosilicate Systems (1968)

The dependence of the emission spectra on compositional variations has been studied in binary alkaline earth orthosilicate systems activated by divalent europium. Isotherms at 1200°C were run in the systems (i) , (ii) , and (iii) . Phosphors produced in the system were considerably more efficient than those in either of the other two systems and consequently were studied in much greater detail. A complete series of crystalline solutions exist between the end‐members at 1200°C. The corresponding emission spectra vary in a fairly continuous manner from 505 nm for the pure barium end‐member to 575 nm for the pure strontium end‐member. X‐ray diffraction data revealed complete crystalline solution between and at 1200°C. However, the low level of brightness and the pronounced asymmetry of the emission peaks rendered this system less amenable to a detailed investigation. Emission spectra indicated the formation of an intermediate compound in the system. The existence of this compound, , was verified by x‐ray diffraction. The emission spectrum of this compound peaks at a considerably lower wavelength (∼490 nm) than those of its bounding compositions. The two later systems were further complicated due to the polymorphism of . Frequently the phase was partially converted from to .
MPLS advantages for traffic engineering (1999)

This article discusses the architectural aspects of MPLS which enable it to address IP traffic management. Specific MPLS architectural features discussed are separation of control and forwarding, the label stack, multiple control planes, and integrated IP and constraint-based routing. The article then discusses how these features address network scalability, simplify network service integration, offer integrated recovery, and simplify network management. Scalability is addressed through integrated routing enabling a natural assignment of traffic to the appropriate traffic engineering tunnels without requiring special mechanisms for loop prevention. Change is greatly reduced. The label stack enables an effective means for local tunnel repair providing fast restoration. Feedback through the routing system permits fast and intelligent reaction to topology changes. Service integration is simplified through a unified QoS paradigm which makes it simple for services to request QoS and have it mapped through to traffic engineering.