pinecone/core-2020-05-10-deduplication huggingface dataset:
Selective Automated Indexing of Findings and Diagnoses in Radiology Reports

AbstractThe recent improvements in capabilities of desktop computers and communications networks give impetus for the development of clinical image repositories that can be used for patient care and medical education. A challenge in the use of these systems is the accurate indexing of images for retrieval performance acceptable to users. This paper describes a series of experiments aiming to adapt the SAPHIRE system, which matches text to concepts in the UMLS Metathesaurus, for the automated indexing of image reports. A series of enhancements to the baseline system resulted in a recall of 63% but a precision of only 30% in detecting concepts. At this level of performance, such a system might be problematic for users in a purely automated indexing environment. However, if the ability to retrieve images in repositories based on content in their reports is desired by clinical users, and no other current systems offer this functionality, then follow-up research questions include whether these imperfect results would be useful in a completely or partially automated indexing environment and/or whether other approaches can improve upon them
Patient Safety, Potential Adverse Drug Events, and Medical Device Design: A Human Factors Engineering Approach

AbstractAdverse drug events are the single leading threat to patient safety. Human factors engineering has been repeatedly proposed, but largely untested, as the key to improving patient safety. The value of this approach was investigated in the context of a commercially available patient-controlled analgesia device that has been linked with several alleged patient injuries and deaths. Several reports have stated that errors in programming drug concentration were made during these adverse drug events. A simulation of the commercially available interface was compared experimentally with a simulated prototype of a new interface designed according to a human factors process. Professional nurses, averaging over 5 years of clinical experience with the commercially available interface and only minimal experience with the new interface, programmed both interfaces. The new interface eliminated drug concentration errors, whereas the simulated commercially available interface did not. Also, the new interface led to significantly fewer total errors and faster performance. These findings may have broad implications for the design, regulation, and procurement of biomedical devices, products, or systems that improve patient safety in clinical settings
A Simple Algorithm for Identifying Negated Findings and Diseases in Discharge Summaries

AbstractNarrative reports in medical records contain a wealth of information that may augment structured data for managing patient information and predicting trends in diseases. Pertinent negatives are evident in text but are not usually indexed in structured databases. The objective of the study reported here was to test a simple algorithm for determining whether a finding or disease mentioned within narrative medical reports is present or absent. We developed a simple regular expression algorithm called NegEx that implements several phrases indicating negation, filters out sentences containing phrases that falsely appear to be negation phrases, and limits the scope of the negation phrases. We compared NegEx against a baseline algorithm that has a limited set of negation phrases and a simpler notion of scope. In a test of 1235 findings and diseases in 1000 sentences taken from discharge summaries indexed by physicians, NegEx had a specificity of 94.5% (versus 85.3% for the baseline), a positive predictive value of 84.5% (versus 68.4% for the baseline) while maintaining a reasonable sensitivity of 77.8% (versus 88.3% for the baseline). We conclude that with little implementation effort a simple regular expression algorithm for determining whether a finding or disease is absent can identify a large portion of the pertinent negatives from discharge summaries
Symbolic Representation of Anatomical Knowledge: Concept Classification and Development Strategies

AbstractIn this paper a novel approach to anatomy knowledge representation is described. The focus of the present research has been on the development of a representational framework where the conceptual level has been implemented by using hierarchical and nonhierarchical conceptual networks. This has allowed handling the demand for multiple views of anatomy (systemic and topographical views). The terminological level of the knowledge representation has been implemented by using a compositional strategy which has avoided the explicit storage of the terms used to express composite concepts. Hierarchical relations and composite concept representations have required supervision of both the inheritance and concept reconstruction. For this purpose heuristic knowledge has been stored in terms of consistency rules in the knowledge base. As proof of the capability of this system, we show how the knowledge base has been used to provide symbolic access to spatial information consisting of a reduced set of images from the Visible Human Dataset
An Evaluation of Extended vs Weighted Least Squares for Parameter Estimation in Physiological Modeling

AbstractWeighted least squares (WLS) is the technique of choice for parameter estimation from noisy data in physiological modeling. WLS can be derived from maximum likelihood theory, provided that the measurement error variance is known and independent of the model parameters and the weights are calculated as the inverse of the measurement error variance. However, using measured values in lieu of predicted values to quantify the measurement error variance is approximately valid only when the noise in the data is relatively low. This practice may thus introduce sampling variation in the resulting estimates, as weights can be seriously misspecified. To avoid this, extended least squares (ELS) has been used, especially in pharmacokinetics. ELS uses an augmented objective function where the measurement error variance depends explicitly on the model parameters. Although it is more complex, ELS accounts for the Gaussian maximum likelihood statistical model of the data better than WLS, yet its usage is not as widespread. The use of ELS in high data noise situations will result in more accurate parameter estimates than WLS (when the underlying model is correct). To support this claim, we have undertaken a simulation study using four different models with varying amounts of noise in the data and further assuming that the measurement error standard deviation is proportional to the model prediction. We also motivate this in terms of maximum likelihood and comment on the practical consequences of using WLS and ELS as well as give practical guidelines for choosing one method over the other
Use of an Interactive Tool to Assess Patients' Willingness-to-Pay

AbstractAssessment of willingness to pay (WTP) has become an important issue in health care technology assessment and in providing insight into the risks and benefits of treatment options. We have accordingly explored the use of an interactive method for assessment of WTP. To illustrate our methodology, we describe the development and testing of an interactive tool to administer a WTP survey in a dental setting. The tool was developed to measure patient preference and strength of preference for three dental anesthetic options in a research setting. It delivered written and verbal formats simultaneously, including information about the risks and benefits of treatment options, insurance, and user-based WTP scenarios and questions on previous dental experience. Clinical information was presented using a modified decision aid. Subjects could request additional clinical information and review this information throughout the survey. Information and question algorithms were individualized, depending on the subject's reported clinical status and previous responses. Initial pretesting resulted in substantial modifications to the initial tool: shortening the clinical information (by making more of it optional reading) and personalizing the text to more fully engage the user. In terms of results 196 general population subjects were recruited using random-digit dialing in southwestern Ontario, Canada. Comprehension was tested to ensure the instrument clearly conveyed the clinical information; the average score was 97%. Subjects rated the instrument as easy/very easy to use (99%), interesting/very interesting (91%), and neither long nor short (72.4%). Most subjects were comfortable/very comfortable with a computer (84%). Indirect evaluation revealed most subjects completed the survey in the expected time (30 min). Additional information was requested by 50% of subjects, an average of 2.9 times each. Most subjects wanted this type of information available in the provider's office for use in clinical decision making (92%). Despite extensive pretesting, three “bugs” remained undiscovered until live use. We have demonstrated that the detailed information, complex algorithms, and cognitively challenging questions involved in a WTP survey can be successfully administered using a tailor-made, patient-based, interactive computer tool. Key lessons regarding the use of such tools include allowing the user to set the pace of information flow and tailor the content, engaging the user by personalizing the textual information, inclusion of tests of comprehension and offering opportunities for correction, and pretesting by fully mimicking the live environment
Methodology Used for “Software for Automated Linkage in Italy” (SALI)

AbstractLinkage of epidemiological registries can provide cost-effective information on the associations between different diseases or exposures in the population under study and on completeness of surveillance system databases. We describe the program SALI (software for automated linkage in Italy) aimed at matching individual records from medium-sized registries (in the order of 100,000 records), where the desired outcome is to miss as few links as possible and, because of low link-likelihood (<1%), a manual revision of matched pairs is feasible. SALI, developed in CA-Clipper language, uses registry files in dBase format. It requires only name, surname, and date of birth as key fields, and it allows for spelling errors in Italian or other Latin languages through a specific algorithm. Furthermore, a double-blind procedure ensures data confidentiality. The main linkage procedure is based on four stages, two automatic ones, and two where the operator can decide through specific windows whether to accept stage-selected matches. SALI takes into account possible errors in key fields thus reducing false negatives. It was used to solve the problem of linkage between AIDS and cancer registries in Italy. It can be used with every IBM-compatible computer system, assuring uniquely high portability
CO oxidation over nonstoichiometric nickel manganite spinels

Nonstoichiometric nickel–manganese spinel oxides, NixMn3−x ▭3δ/4O4+δ (1≥x≥0), have been synthesized by calcination in air of mixed oxalates at 623 K. These materials are shown to be highly reactive for CO oxidation, some conversion being observed at room temperature for the most active solid (x=1.0). The interaction of CO and O2 with these oxides has been studied by in situ IR spectroscopy under steady-state and transient reaction conditions. A detailed mechanism is proposed wherein CO reacts with coordinatively unsaturated cations to give carbonyl complexes which in turn react with surface oxygen activated on anionic vacancies. Adsorbed and gaseous CO2 also undergo much slower side reactions with lattice oxygen or surface hydroxide groups to give more stable hydrogen carbonate and carbonates species, which lead to catalyst deactivation. Marked effects of pretreatment are explained on the basis of the observed kinetics and the proposed mechanis
TiO2-Photocatalyzed Epoxidation of 1-Decene by H2O2 under Visible Light

1-Decene was converted to 1,2-epoxydecane on UV-irradiated TiO2 powder using molecular oxygen as the oxygen source. Other main products were nonanal and 2-decanone. For anatase-form TiO2 powders, the reaction rate was hardly affected by addition of hydrogen peroxide to the solution. In contrast, for rutile-form TiO2 powders, the rate of epoxide generation was significantly increased by addition of hydrogen peroxide. In this case, the reaction occurred under visible light as well as UV light. The selectivity of the production of 1,2-epoxydecane was higher under visible light than under UV light. The conversion efficiency of an incident photon to 1,2-epoxydecane was about 2% when irradiated with visible light in the range 440–480 nm. UV–visible diffuse reflection spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy suggested the generation of a Ti–η2-peroxide on rutile TiO2 surface after treatment with hydrogen peroxide. The initial step of the reaction under visible light was attributed to a photochemical reaction of this peroxide with 1-decene
The Politics of Co-optation

Our model consists of two groups. Group 1 holds political power and Group 2 threatens this power. Group 1 decreases the probability of its upheaval by co-opting some agents from Group 2 into a more benign third group. Improvements in the upheaval technology lead to fewer but better co-optation offers. Increasing the size and/or the degree of fragmentation of Group 2 has the opposite effect. If the co-opted group also threatens Group 1, co-optation transfers are reduced. Our model provides a new explanation of why growth is a politically stabilizing force. The theory suggests that, in post-Communist privatizations, unstable governments will give large benefits to a small number of beneficiaries while stable governments will give small benefits to a large group
Physicochemical Characterization of Natural and ex-Situ Reconstructed Sea-Surface Microlayers

Chemical composition and physico-chemical characteristics of natural and ex-situ reconstructed sea surface microlayer samples were studied using a complex methodological approach. Surface microlayer samples and the underlying seawater were collected in different seasons and different conditions in the northern most part of the Adriatic Sea. The techniques used were thin layer chromatography with flame ionization detection for lipid classes analysis, electrochemical characterization of adsorbable organic substances using the ONP probe, and monolayer techniques for surface pressure and surface potential measurements, as well as Brewster angle microscopy. Our results indicated higher enrichment of organic matter for the microlayer sample collected in the warm period of the year (summer). This was reflected in the high surface activity of the present organic substances, and formation of a more condensed layer than for the other two samples collected in the spring. Of the two spring samples, the one sampled on a sunny day was reacher in surface active organic material. We concluded that the most important source of surface active substances in the in-situ production of organic substances by the present plankton and bacteria, promoted by sunlight, while antrophogenic input comprises a smaller part of the present organic matter, around 10% for all samples
Mechanism of Formation of Monodispersed Colloids by Aggregation of
  Nanosize Precursors

It has been experimentally established in numerous cases that precipitation
of monodispersed colloids from homogeneous solutions is a complex process.
Specifically, it was found that in many systems nuclei, produced rapidly in a
supersaturated solution, grow to nanosize primary particles (singlets), which
then coagulate to form much larger final colloids in a process dominated by
irreversible capture of these singlets. This paper describes a kinetic model
that explains the formation of dispersions of narrow size distribution in such
systems. Numerical simulations of the kinetic equations, with experimental
model parameter values, are reported. The model was tested for a system
involving formation of uniform spherical gold particles by reduction of auric
chloride in aqueous solutions. The calculated average size, the width of the
particle size distribution, and the time scale of the process, agreed
reasonably well with the experimental values.Comment: 38 pages in plain TeX and 7 JPG figure
Equilibrium and kinetics of NO and CO chemisorptions on nonstoichiometric nickel-copper manganites

The equilibrium and kinetics of adsorption of NO and CO on nonstoichiometric nickel-copper manganites have been investigated through volumetric measurements. The adsorption isotherms were satisfactorily fitted to the Freundlich equation. The equilibrium coverages at 298 K were found to depend closely on the chemical composition of the oxide; thus, a decrease in the coverage beyond a maximum copper extent was observed. The adsorption isotherms of NO at various temperatures in the range from 298 to 473 K showed that the equilibrium coverage decreases with increasing temperature. This behavior enabled us to follow the logarithmic decrease of the heat of adsorption of NO on such surfaces. The adsorptions of NO and CO on surfaces preadsorbed with CO and NO, respectively, were also studied. These experiments showed the ability of NO to displace CO preadsorbed molecules whereas the contrary did not hold, suggesting the existence of common adsorption sites as well as some specific CO adsorption sites. Finally, some kinetic data are reported showing that the experimental adsorption results fit the Elovich equation (with t(0) approximate to 0), although two distinct rate processes could be identified
Deintercalation of hydrazine-intercalated kaolinite in dry and moist air

The deintercalation of a low defect kaolinite intercalated with hydrazine has been followed by X-ray diffraction, diffuse reflectance infrared spectroscopy (DRIFT) and Raman microscopy over an extended period of time. X-ray diffraction showed the kaolinite was totally intercalated and that more than 120 hours were required for the hydrazine intercalate to be decomposed. The Raman spectra of the hydrazine intercalate showed only a single band at 3620 cm-1 attributed to the inner hydroxyl group. Upon deintercalation additional Raman bands were observed at 3626 and 3613 cm-1. These bands decreased in intensity with further deintercalation. As deintercalation occurs the bands assigned to the inner surface hydroxyl groups at 3695, 3682, 3670 and 3650 cm-1 appeared and increased in intensity. DRIFT spectra showed two bands at 3620 and 3626 cm-1 for the fully intercalated kaolinite only. Upon deintercalation an additional band assigned to intercalated water was observed at 3599 cm-1 and increased in intensity at the expense of the 3626 cm-1 band. Further, the bands attributed to the inner surface hydroxyl groups increased in intensity with deintercalation. Both the Raman and DRIFT spectra showed complexity in the NH stretching region with two sets of NH symmetric and asymmetric stretching bands observed. Deintercalation was easily followed by the loss of intensity of these bands. Significant changes were also observed in the hydroxyl deformation and water bending modes as a result of deintercalation. A new model of hydrazine intercalation of kaolinite based on the insertion of a hydrazine-water unit is proposed. The hydrated end of the hydrazine molecule hydrogen bonds with the inner surface hydroxyl groups resulting in the formation of the new band at 3626 cm-1 in the DRIFT spectra
Dielectrophoretic behavior of latex nanospheres: Low-frequency dispersion

The electrostatic manipulation of nanoparticles using nonuniform electric fields (dielectrophoresis) has proved a useful method of investigating the movement of charge around colloidal particles. While previous work has explained many of the ways in which particle behavior deviates from that predicted by classical Maxwell-Wagner interfacial polarization theory, there exists an additional, anomalous polarization mechanism observed in media of high conductivity, causing an unexpected observation of positive dielectrophoresis. Here this is suggested that this may be explained in terms of the polarization of the Stern layer
Complexity of Intercalation of Hydrazine into Kaolinite - A Controlled Rate Thermal Analysis and DRIFT Spectroscopic Study

Controlled rate thermal analysis (CRTA) allows the separation of adsorbed and intercalated hydrazine. CRTA displays the presence of three different types of hydrogen-bonded hydrazine in the intercalation complex: (a) The first is adsorbed loosely bonded on the kaolinite structure fully expanded by hydrazine–hydrate and liberated between approx 50 and 70 degrees Celsius (b) The second intercalated hydrazine is lost between approx 70 and 85 degrees Celsius. (c) The third type of intercalated-hydrazine molecule is lost in the 85–130 degrees Celsius range. CRTA at 70 degrees Celsius enables the removal of hydrazine–water and results in the partial collapse of the hydrazine-intercalated kaolinite structure to form a hydrazine-intercalated kaolinite. Removal of the adsorbed hydrazine enables the DRIFT spectra of the hydrazine-intercalated complex without any adsorbed hydrazine to be obtained. A band at 3626 cm−1 attributed to the inner surface hydroxyls of kaolinite hydrogen bonded to hydrazine is observed. The intercalation of hydrazine–hydrate into kaolinite is complex and results from the different types of surface interactions of the hydrazine with the kaolinite surfaces
Information Complexity of Multivariate Fredholm Integral Equations in Sobolev Classes

AbstractIn this paper, the complexity of full solution of Fredholm integral equations of the second kind with data from the Sobolev classWr2is studied. The exact order of information complexity is derived. The lower bound is proved using a Gelfand number technique. The upper bound is shown by providing a concrete algorithm of optimal order, based on a specific hyperbolic cross approximation of the kernel function. Numerical experiments are included, comparing the optimal algorithm with the standard Galerkin method
n-Widths, Faber Expansion, and Computation of Analytic Functions

AbstractLetBH∞(Ω) be the space of analytic functionsfin the region Ω for which |f(z)| ≤ 1,z∈ Ω, and letKbe a compact subset of Ω. How can we compute the values of any functionf∈BH∞(Ω) at an arbitrary pointz∈K? One of the approaches to this problem applies the results concerning then-widths and ϵ-entrophy of classBH∞(Ω) in the metricC(K). In the case whenKhas a simply connected complement inC and Ω is a canonical neighbourhood ofK, the classical tools for approximation off∈BH∞(Ω) inC(K) give the Faber series. This work is concerned with the following: the exact values of Kolmogorov and othern-widths of Hardy spacesHp, then-widths and ϵ-entrophy of classBH∞(Ω), the optimality of Faber approximations, and computing values of analytic functions with the help of Faber series