gebhart/patrepeval huggingface dataset:
Usability of CAPTCHAs or usability issues in CAPTCHA design (2008)

CAPTCHA is now almost a standard security technology, and has found widespread application in commercial websites. Usability and robustness are two fundamental issues with CAPTCHA, and they often interconnect with each other. This paper discusses usability issues that should be considered and addressed in the design of CAPTCHAs. Some of these issues are intuitive, but some others have subtle implications for robustness (or security). A simple but novel framework for examining CAPTCHA usability is also proposed.
Mechanisms of human insulin resistance and thiazolidinedione-mediated insulin sensitization (2009)

Cellular and tissue defects associated with insulin resistance are coincident with transcriptional abnormalities and are improved after insulin sensitization with thiazolidinedione (TZD) PPARgamma ligands. We characterized 72 human subjects by relating their clinical phenotypes with functional pathway alterations. We transcriptionally profiled 364 biopsies harvested before and after hyperinsulinemic-euglycemic clamp studies, at baseline and after 3-month TZD treatment. We have identified molecular and functional characteristics of insulin resistant subjects and distinctions between TZD treatment responder and nonresponder subjects. Insulin resistant subjects exhibited alterations in skeletal muscle (e.g., glycolytic flux and intramuscular adipocytes) and adipose tissue (e.g., mitochondrial metabolism and inflammation) that improved relative to TZD-induced insulin sensitization. Pre-TZD treatment expression of MLXIP in muscle and HLA-DRB1 in adipose tissue from insulin resistant subjects was linearly predictive of post-TZD insulin sensitization. We have uniquely characterized coordinated cellular and tissue functional pathways that are characteristic of insulin resistance, TZD-induced insulin sensitization, and potential TZD responsiveness.
Enabling Electronic Healthcare Information Exchange (2007)

The Unified Medical Language System (UMLS) Metathesaurus enables the standardized representation of healthcare information so that it can be correctly stored, manipulated, retrieved, and exchanged.
3.5 A 0.6V 13b 20MS/s Two-Step TDC-Assisted SAR ADC with PVT Tracking and Speed-Enhanced Techniques (2019)

The two-step SAR ADC is an energy-efficient architecture for high-resolution applications, which faces headroom challenges from the voltage-domain residue amplification under a low power supply. A TDC-assisted SAR ADC [1] uses a voltage-to-time converter (VTC) and a TDC as the back-end to quantize the residue voltage of the SAR ADC, which is attractive to the low power supply scenarios by moving the voltage domain quantization of a two-step SAR ADC into the time domain. However, the TDC-assisted SAR ADC encounters several design challenges. For example, it is sensitive to PVT variations due to partial time-domain operation, and its conversion speed is limited significantly by the long VTC latency when there is a small residue input voltage. This paper presents both PVT tracking and speed enhancement techniques for a 13b two-step TDC-assisted SAR ADC with 0.6V supply. The VTC and the back-end TDC are designed to have a common operation characteristic; thereby, their variations over PVT are inherently tracked without the need of any extra power or circuit overheads. The prototype ADC achieves less than 0.8dB SNDR drop across - 50°C to 90°C and ±5% power supply variation at 20MS/s. The Walden FoM is 1.4fJ/conversion-step.
Effect of poly(propylene carbonate) on the crystallization and melting behavior of poly(β‐hydroxybutyrate‐<i>co</i>‐β‐hydroxyvalerate) (2004)

Abstract The crystallization and melting behavior of poly(β‐hydroxybutyrate‐ co ‐β‐hydroxyvalerate) (PHBV) and a 30/70 (w/w) PHBV/poly(propylene carbonate) (PPC) blend was investigated with differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR). The transesterification reaction between PHBV and PPC was detected in the melt‐blending process. The interaction between the two macromolecules was confirmed by means of FTIR analysis. During the crystallization process from the melt, the crystallization temperature of the PHBV/PPC blend decreased about 8°C, the melting temperature was depressed by 4°C, and the degree of crystallinity of PHBV in the blend decreased about 9.4%; this was calculated through a comparison of the DSC heating traces for the blend and pure PHBV. These results indicated that imperfect crystals of PHBV formed, crystallization was inhibited, and the crystallization ability of PHBV was weakened in the blend. The equilibrium melting temperatures of PHBV and the 30/70 PHBV/PPC blend isothermally crystallized were 187.1 and 179°C, respectively. The isothermal crystallization kinetics were also studied. The fold surface free energy of the developing crystals of PHBV isothermally crystallized from the melt decreased; however, a depression in the relative degree of crystallization, a reduction of the linear growth rate of the spherulites, and decreases in the equilibrium melting temperature and crystallization capability of PHBV were detected with the addition of PPC. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2514–2521, 2004
Focusing properties of curved x-ray diffractors (1990)

Calculations are described and results are given for the focusing properties of six curved x-ray diffractors for Bragg angles ranging from 15° to 75°. The geometries considered include cylindrical, spherical, and toroidal cases. The type of slit necessary to eliminate stray radiation in applications of doubly curved diffractors to scanning monochromators is discussed. Three of the most efficient diffractors are compared with respect to the solid angle for collection of x rays and the possible spectral resolution. A diffractor with spherically curved planes and toroidally curved surface is shown to be superior to the Johansson geometry and the spherically curved plate.
Structure-Performance Relationships in Surfactants (2003)

Focuses on the relationships between surfactant structure and performance. The text offers coverage of a range of topics in the field, including theories of micelle formation and adsorption, the dynamics of surfactant solutions, the physiochemical properties of structured surfactant and emulsions, adsorption characteristics, and the preparation of microparticles in reversed micelles.
A simple method for the synthesis of long-chain alkyl esters of amino acids (1985)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA simple method for the synthesis of long-chain alkyl esters of amino acidsChristopher L. Penney, Pravinkant Shah, and Silvio LandiCite this: J. Org. Chem. 1985, 50, 9, 1457–1459Publication Date (Print):May 1, 1985Publication History Published online1 May 2002Published inissue 1 May 1985https://pubs.acs.org/doi/10.1021/jo00209a018https://doi.org/10.1021/jo00209a018research-articleACS PublicationsRequest reuse permissionsArticle Views857Altmetric-Citations28LEARN 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
Response-Locked Brain Dynamics of Word Production (2013)

The cortical regions involved in the different stages of speech production are relatively well-established, but their spatio-temporal dynamics remain poorly understood. In particular, the available studies have characterized neural events with respect to the onset of the stimulus triggering a verbal response. The core aspect of language production, however, is not perception but action. In this context, the most relevant question may not be how long after a stimulus brain events happen, but rather how long before the production act do they occur. We investigated speech production-related brain activity time-locked to vocal onset, in addition to the common stimulus-locked approach. We report the detailed temporal interplay between medial and left frontal activities occurring shortly before vocal onset. We interpret those as reflections of, respectively, word selection and word production processes. This medial-lateral organization is in line with that described in non-linguistic action control, suggesting that similar processes are at play in word production and non-linguistic action production. This novel view of the brain dynamics underlying word production provides a useful background for future investigations of the spatio-temporal brain dynamics that lead to the production of verbal responses.
Antiangiogenesis by cyclosporine. (1998)

The effects of cyclosporine on certain endothelial cell functions, namely matrix metalloprotease (MMP)-2 and MMP-9 secretion, proliferation, chemotaxis, and morphogenesis, were investigated in vitro, and its effects on angiogenesis were studied in vivo by using the chick embryo chorioallantoic membrane (CAM) model. In vitro, at low noncytotoxic doses (2, 4, 8, and 16 microg/mL), cyclosporine inhibited all these functions in a dose-dependent manner, although MMP-2 secretion was inhibited only at 16 microg/mL. The absence of cytotoxicity was confirmed morphologically and also because inhibition was rapidly reversed as soon as cyclosporine was removed. In vivo, cyclosporine at 0.012 and 0.024 microg per CAM displayed noncytotoxic, dose-dependent antiangiogenic activity. Biochemically, the drug inhibited the activity of the endothelial cell respiratory chain enzymes succinate oxidase and cytochrome-c oxidase, again in a dose-dependent manner. This finding could explain the effects observed in vitro and in vivo. These antiangiogenic properties of low-dose cyclosporine warrant further investigation in certain autoimmune and neoplastic diseases characterized by enhanced angiogenesis.
Data Mining the NCI60 to Predict Generalized Cytotoxicity (2008)

Elimination of cytotoxic compounds in the early and later stages of drug discovery can help reduce the costs of research and development. Through the application of principal components analysis (PCA), we were able to data mine and prove that approximately 89% of the total log GI 50 variance is due to the nonspecific cytotoxic nature of substances. Furthermore, PCA led to the identification of groups of structurally unrelated substances showing very specific toxicity profiles, such as a set of 45 substances toxic only to the Leukemia_SR cancer cell line. In an effort to predict nonspecific cytotoxicity on the basis of the mean log GI 50, we created a decision tree using MACCS keys that can correctly classify over 83% of the substances as cytotoxic/noncytotoxic in silico, on the basis of the cutoff of mean log GI 50 = -5.0. Finally, we have established a linear model using least-squares in which nine of the 59 available NCI60 cancer cell lines can be used to predict the mean log GI 50. The model has R (2) = 0.99 and a root-mean-square deviation between the observed and calculated mean log GI 50 (RMSE) = 0.09. Our predictive models can be applied to flag generally cytotoxic molecules in virtual and real chemical libraries, thus saving time and effort.
The Revealing Role of Pressure in the Condensed Matter Sciences (1998)

Matter in bulk has both a microscopic and macroscopic description, with the latter going back to the very earliest days of thermodynamics. Of the common thermodynamic variables pressure (p) and temperature (T), it is temperature that has played by far the most prominent role in probing condensed matter and in our fundamental understanding of it. However, even as far back as 1660, Robert Boyle declared in his famous treatise commonly known as Touching the Spring of the Air that “perhaps the pressure of the air might have an interest in more phenomena than men have hitherto thought.” More than three centuries later, we can see how right he was, as systematic use of pressure has led to considerable insight into the properties of matter, especially its electronic properties. As A. Jayaraman noted when he was at AT&T Bell Laboratories, of all physical variables, pressure possesses one of the greatest ranges—over 60 orders of magnitude. At the high end, the pressures are those of the interiors of neutron stars; at the other, they gauge the conditions of the remotest vacua of outer space. And as Claude Berthelot demonstrated in early experiments on simple fluids, the pressure is not even obliged to be positive. (Negative pressure is created by, for example, pulling on the surface of a solid or on a wall of a sealed vessel full of fluid.)
Effects of Enzyme Preparations Supplementation on Performance in Broilers (2008)

The aim of this study was to investigate the effects of enzyme preparations supplementation on performance in broilers. A total of 240 1-day-old male Avian broilers were randomly divided into 2 groups with 4 replicates per group and 20 birds in each replicate. The experimental period was 42 days. The results showed that the average body weight increased by 6.63% in enzyme preparations-supplemented broilers at 42 d of age (P0.05) and average daily gain was increased by 6.77% from 1 to 42 d of age (P0.05). There were no significant differences in average daily feed intake of broilers in each phase(P0.05) and enzyme supplementation decreased by 9.18% of F∶G from 1 to 42 d of age (P0.05). Average feed cost decreased by 1.83% from 1 to 42 d of age (P 0.05) and average income increased by 6.65% (P0.05).
Cast and Splint Immobilization: Complications (2008)

During the past three decades, internal fixation has become increasingly popular for fracture management and limb reconstruction. As a result, during their training, orthopaedic surgeons receive less formal instruction in the art of extremity immobilization and cast application and removal. Casting is not without risks and complications (eg, stiffness, pressure sores, compartment syndrome); the risk of morbidity is higher when casts are applied by less experienced practitioners. Certain materials and methods of ideal cast and splint application are recommended to prevent morbidity in the patient who is at high risk for complications with casting and splinting. Those at high risk include the obtunded or comatose multitrauma patient, the patient under anesthesia, the very young patient, the developmentally delayed patient, and the patient with spasticity.
Countering beam divergence effects with focused segmented scintillators for high DQE megavoltage active matrix imagers (2012)

The imaging performance of active matrix flat-panel imagers designed for megavoltage imaging (MV AMFPIs) is severely constrained by relatively low x-ray detection efficiency, which leads to a detective quantum efficiency (DQE) of only ∼1%. Previous theoretical and empirical studies by our group have demonstrated the potential for addressing this constraint through the utilization of thick, two-dimensional, segmented scintillators with optically isolated crystals. However, this strategy is constrained by the degradation of high-frequency DQE resulting from spatial resolution loss at locations away from the central beam axis due to oblique incidence of radiation. To address this challenge, segmented scintillators constructed so that the crystals are individually focused toward the radiation source are proposed and theoretically investigated. The study was performed using Monte Carlo simulations of radiation transport to examine the modulation transfer function and DQE of focused segmented scintillators with thicknesses ranging from 5 to 60 mm. The results demonstrate that, independent of scintillator thickness, the introduction of focusing largely restores spatial resolution and DQE performance otherwise lost in thick, unfocused segmented scintillators. For the case of a 60 mm thick BGO scintillator and at a location 20 cm off the central beam axis, use of focusing improves DQE by up to a factor of ∼130 at non-zero spatial frequencies. The results also indicate relatively robust tolerance of such scintillators to positional displacements, of up to 10 cm in the source-to-detector direction and 2 cm in the lateral direction, from their optimal focusing position, which could potentially enhance practical clinical use of focused segmented scintillators in MV AMFPIs.
Suppression of Dewetting in Nanoparticle-Filled Polymer Films (2000)

The perturbing influence of nanosize filler particles on the dewetting of spun-cast polymer films is investigated. Previous studies have shown that spun-cast films of unentangled polystyrene (PS) and polybutadiene (PB) dewet acid-cleaned silicon wafers when the films are annealed above their bulk glass transition temperature Tg. It is also known that “impurity” particles tend to promote dewetting in thin polymer films. Here we demonstrate that the addition of a small amount of C60 fullerene nanoparticles to the spin-casting polymer solution leads to an inhibition of dewetting in thin (L < 100 nm) PS and PB films cast on both acid-cleaned and carbon-coated silicon wafer substrates. Neutron reflection measurements indicate that this effect is associated with the formation of a diffuse fullerene layer near the solid substrate. Evidently, the immobilized fullerene particles form an enrichment layer at the solid boundary and “pin” the contact line of the growing dewetted (“dry”) regions so that hole growth in the filled films becomes arrested at a scale which diminishes with increasing filler concentration. Above a relative filler−polymer mass fraction of 1%, we no longer observe hole formation by atomic force microscopy on the time scales of our measurements (typically on the order of hours), suggesting the existence of a critical filler surface coverage for the suppression of dewetting. The roughness of the fullerene layer probably also contributes to the modification of the surface wetting properties through a change in the surface energy of the substrate, as suggested by recent measurements on substrates “roughened” by other means such as irradiation of polymer film substrates, grafting of polymer chains, etc.
Recent advances in the discovery of non-peptidic direct renin inhibitors as antihypertensives: new patent applications in years 2000 – 2008 (2008)

Background: The renin-angiotensin-aldosterone system (RAAS) is essential for the regulation of blood pressure and may play a critical role in the pathogenesis of cardiovascular diseases. A strong rationale suggests a more efficient control of RAAS by direct rather than downstream blockade of renin, an angiotensinogen-specific aspartic protease acting at the first, rate-limiting step of the pathway. Vast research efforts since the late 1970s have aimed at developing clinically useful renin inhibitors for the treatment of hypertension and associated co-morbidities. In 2007, aliskiren (Tekturna®, Rasilez®; Novartis) was launched as the first orally efficacious direct renin inhibitor. The evolution of non-peptide renin inhibitors interacting with non-substrate recognition sites of the enzyme, such as aliskiren and the 4-aryl-piperidines, during the 1990s encouraged an increasing number of pharmaceutical companies to resume, or newly embark on, drug discovery programs. Objective: This review summarizes the various structural design concepts and the apparent focus of activities presently employed to develop follow-up generations of oral renin inhibitors. Methods: Information was collected from patents, scientific literatures and public sources disclosed during the years 2000 – 2008. Results/conclusion: The structural diversity of small-molecule inhibitors has further increased, including novel basic surrogate transition-state mimetic motifs. Several inhibitors emerged as (pre)clinical candidates, the most advanced having entered Phase II clinical trials.
Investigation of thin aluminium films on the rear of monocrystalline silicon solar cells for back surface field formation (2003)

The trend to thinner crystalline silicon wafers in the production of silicon solar cells instigates a re-evaluation of the back surface field (BSF) formation. Aluminium layers, whose thickness is typically over 10 /spl mu/m, are commonly used for BSF formation. Such thick films, however, cause severe warping on thin solar cells (<250 /spl mu/m). This study investigates the use of thin Al films of between 0.1 and 2.0 /spl mu/m and focuses on the aluminium/rear surface structure after sintering in a mixed nitrogen and oxygen gas atmosphere at temperatures between 820/spl deg/C and 995/spl deg/C. It is shown that the rear surface morphology has a strong influence on the reaction of Al with Si. Secondary electron and focused ion beam microscopy reveal that thin Al layers form Al islands on smooth surfaces but the Al agglomerates at the apex of pyramids when the surface is textured. In both cases the Al dissolves the Si rear surface inhomogeneously. The structural results are correlated with electrical measurements of laser grooved buried contact solar cells. The correlation shows increasing short circuit current with increasing Al film thickness. The results are used to explain deviations of the standard theory of the Al:BSF formation when using thin Al films.