gebhart/patrepeval huggingface dataset:
Proposal to produce novel, transparent radiation hard low refractive index polymers. Final report, 1 October-31 December 1993 (1994)

Low and high molecular weight polymers of heptafluorobutyl methacrylate, HFBM, were prepared for commercial evaluation by Bicron, an optical fiber manufacturer. Polymers were evaluated as low refractive index fiber cladding materials. Test results of Low MW polymer solutions gave excellent results. Higher MW polymers were prepared for cladding by melt co-extrusion. Corning Glass Corp, also expressed an interest in these cladding materials. These results appear to be sufficiently unique that a search has been initiated to determine patentability of the soluble fluorocarbon acrylate, methacrylate and copolymer compositions for cladding use. This research resulted in identifying a radiation hard, low refractive index polymer, poly(heptafluorobutyl methacrylate), P(HFBM) as the best candidate for a novel cladding material. P(HFBM) has a refractive index of 1.387. When used to clad a styrene core, the theoretical light propagation efficiency is 50% greater than that of styrene fiber core clad with PMMA, a common commercial cladding material. These polymers will be the only commercial fluorocarbon acrylic cladding polymers available to U.S. manufacturers. Japanese optical fiber manufacturers produce fluorocarbon clad fibers but their polymers are not available to U.S. manufacturers. These polymers can fill an urgent need in the optical fiber market.
Wnt signaling directs human pluripotent stem cells into vascularized cardiac organoids with chamber-like structures (2022)

Heart diseases are leading cause of death around the world. Given their unique capacity to self-renew and differentiate into all types of somatic cells, human pluripotent stem cells (hPSCs) hold great promise for heart disease modeling and cardiotoxic drug screening. hPSC-derived cardiac organoids are emerging biomimetic models for studying heart development and cardiovascular diseases, but it remains challenging to make mature organoids with a native-like structure <i>in vitro</i>. In this study, temporal modulation of Wnt signaling pathway co-differentiated hPSCs into beating cardiomyocytes and cardiac endothelial-like cells in 3D organoids, resulting in cardiac endothelial-bounded chamber formation. These chambered cardiac organoids exhibited more mature membrane potential compared to cardiac organoids composed of only cardiomyocytes. Furthermore, a better response to toxic drugs was observed in chamber-contained cardiac organoids. In summary, spatiotemporal signaling pathway modulation may lead to more mature cardiac organoids for studying cardiovascular development and diseases.
Importance Sampling Techniques for Path Tracing in Participating Media (2012)

Abstract We introduce a set of robust importance sampling techniques which allow efficient calculation of direct and indirect lighting from arbitrary light sources in both homogeneous and heterogeneous media. We show how to distribute samples along a ray proportionally to the incoming radiance for point and area lights. In heterogeneous media, we decouple ray marching from light calculations by computing a representation of the transmittance function that can be quickly evaluated during sampling, at the cost of a small amount of bias. This representation also allows the calculation of another probability density function which can direct samples to regions most likely to scatter light. These techniques are orthogonal and can be combined via multiple importance sampling to further reduce variance. Our method has very modest per‐ray memory requirements and does not require any preprocessing, making it simple to integrate into production ray tracing based renderers.
Synthese primärer und sekundärer Phosphane durch selektive Alkylierung von PH<sub>3</sub> unter Phasentransferbedingungen / Synthesis of Primary and Secondary Phosphines by Selective Alkylation of PH<sub>3</sub> under Phase Transfer Conditions (1990)

Primary phosphines, RPH 2 , may be synthesized selectively by alkylation of phosphine, PH 3 , with alkyl halides RX (R = Me, Et, n-Bu, 2-Bu, C 16 H 33 , CH 2 =CH–CH 2 , Ph–CH 2 , 2-Py–CH 2 –CH 2 ; X = Cl, Br) and concentrated aqueous KOH as auxilliary base in dimethylsulfoxide as a solvent or in two phase systems employing phase transfer catalysts. Under more rigorous conditions secondary phosphines R 2 PH (R = Me, n-Bu, CH 2 =CH–CH 2 ) are also accessible in good yields. Using 1,3-dibromo(chloro)-propane or -butane diprimary phosphines H 2 P–(CH 2 ) 2 –CHR–PH 2 (R = H, Me) are obtained, while 1,4-dibromopentane in a high yield cyclization reaction leads to 2-methylphospholane (12) with a chiral C-atom in a-position.
Optimization of a Series of Mu Opioid Receptor (MOR) Agonists with High G Protein Signaling Bias (2018)

While mu opioid receptor (MOR) agonists are especially effective as broad-spectrum pain relievers, it has been exceptionally difficult to achieve a clear separation of analgesia from many problematic side effects. Recently, many groups have sought MOR agonists that induce minimal βarrestin-mediated signaling because MOR agonist-treated βarrestin2 knockout mice were found to display enhanced antinociceptive effects with significantly less respiratory depression and tachyphylaxis. Substantial data now exists to support the premise that G protein signaling biased MOR agonists can be effective analgesic agents. We recently showed that, within a chemical series, the degree of bias correlates linearly with the magnitude of the respiratory safety index. Herein we describe the synthesis and optimization of piperidine benzimidazolone MOR agonists that together display a wide range of bias (G/βarr2). We identify structural features affecting potency and maximizing bias and show that many compounds have desirable properties, such as long half-lives and high brain penetration.
Neuronal Activity–Induced Gadd45b Promotes Epigenetic DNA Demethylation and Adult Neurogenesis (2009)

The mammalian brain exhibits diverse types of neural plasticity, including activity-dependent neurogenesis in the adult hippocampus. How transient activation of mature neurons leads to long-lasting modulation of adult neurogenesis is unknown. Here we identify Gadd45b as a neural activity-induced immediate early gene in mature hippocampal neurons. Mice with Gadd45b deletion exhibit specific deficits in neural activity-induced proliferation of neural progenitors and dendritic growth of newborn neurons in the adult hippocampus. Mechanistically, Gadd45b is required for activity-induced DNA demethylation of specific promoters and expression of corresponding genes critical for adult neurogenesis, including brain-derived neurotrophic factor and fibroblast growth factor. Thus, Gadd45b links neuronal circuit activity to epigenetic DNA modification and expression of secreted factors in mature neurons for extrinsic modulation of neurogenesis in the adult brain.
Cellular and humoral immune responses to recombinant antigens in sheep infected with <i>Toxoplasma gondii</i> (1995)

Immune responses to recombinant fragments of the Toxoplasma gondii antigens ROP2 and GRA2 were investigated in sheep naturally and experimentally infected with T. gondii oocysts. Specific serum antibodies to C-terminal fragments were detected by ELISA. Cell-mediated responses in peripheral blood mononuclear cells were demonstrated by proliferation and interferon-gamma production following in vitro stimulation with the ROP2 fragment. This data indicates the presence of epitopes for sheep B cells in the recombinant GRA2 fragment and for both B and T cells in the ROP2 fragment.
High-resolution restoration of images distorted by the atmosphere, based on an average atmospheric modulation transfer function (1995)

A new method of real-time high-resolution imaging through the atmosphere is presented. This technique is based on knowledge of average atmospheric modulation transfer function (MTF) at the time the image is received. Atmospheric effects are modeled by a noisy spatial frequency filter including an average component described by the average atmospheric MTF and a noisy component modeled by the atmospheric point spread function's power spectral density. The noisy component represents random changes in the atmospheric MTF. Analytical results are accompanied by experimental image restoration examples, indicating significant image quality improvement based on knowledge of average atmospheric MTF, which includes both turbulence and aerosol MTF components. This method can be used to help overcome the jitter characteristics of turbulence, and is capable of yielding real-time image restoration with resolution limited essentially only by the hardware itself. Turbulence blur, aerosol blur, and contrast degradation are all corrected simultaneously, unlike adaptive optics, which corrects for turbulence only.
EPIQ: A new Active Queue Management paradigm for Packet video (2016)

In this paper, we introduce a new Active Queue Management (AQM) paradigm and a corresponding congestion control mechanism for a novel video-streaming framework. We call the proposed framework Erasable Packets within Internet Queues (EPIQ). EPIQ exhibits best-effort complexity within the network, similar to the networking complexity of HTTP-based Adaptive Streaming (HAS); yet EPIQ can provide optimal quality-of-experience performance similar to the performance of high-complexity multi-queue solutions. EPIQ exploits the inherent multi-priority nature of video to deliver optimal quality-of-experience without requiring any additional overhead in terms of redundant packets or network resources such as multiple queues and without the need to maintain state information about flows. The novelty of EPIQ is rooted in its packetization. Each EPIQ packet consists of multiple segments, and where each segment carries different priority video content. Under congestion, a network router can simply partially erase only small portions of the EPIQ packets instead of dropping complete packets. We show through an analytical model and extensive simulations that this new paradigm in video streaming provides significant improvements over HAS solutions in terms of quality-of-experience metrics. These significant improvements are achieved while maintaining fairness, stability, and low-complexity within the network.
Direct Method for Optimization of a Centrifugal Compressor Vaneless Diffuser (2000)

A Direct Method for Optimization (DMO) is developed for investigating pressure rise and energy loss in a vaneless diffuser of a generic compressor used in shipboard air-conditioning systems. The scheme uses Reynolds-Averaged Navier–Stokes (RANS) results and evaluates gradients of a predetermined objective function. The current Direct Method for Optimization differs from the popular Inverse Design Method in the process of obtaining final configurations and in the final configurations obtained. The Direct Method for Optimization achieves a final shape from maximizing/minimizing a nonlinear function, i.e., the objective function. Both gradient and nongradient Direct Methods for Optimization are compared with respect to accuracy and efficiency. The coupled DMO/RANS optimization code is benchmarked using a plane turbulent diffuser also investigated by Zhang et al. using an adjoint method. The benchmark indicates that if a global optimum exists, the result should be independent of the methodologies or design parameters used. The DMO/RANS method is applied to redesign a three-dimensional centrifugal vaneless diffuser used in a modern generic compressor. The objective function is a composite function of the diffuser’s pressure rise and total energy loss. The new optimum diffuser has a minimum width at a location far beyond the conventional diffuser pinch point. The new diffuser also provides an efficient section for pressure recovery, which takes place after the minimum width location. Test data for the new diffuser validate the current approach at the design condition. Furthermore, improved performance is also recorded experimentally at off-design conditions for the optimized diffuser.
Confidence measures for statistical machine translation (2003)

In this paper, we present several confidence measures for (statistical) machine translation. We introduce word posterior probabilities for words in the target sentence that can be determined either on a word graph or on an N best list. Two alternative confidence measures that can be calculated on N best lists are proposed. The performance of the measures is evaluated on two different translation tasks: on spontaneously spoken dialogues from the domain of appointment scheduling, and on a collection of technical manuals. 1
Plasmon–Plasmon Hybridization and Bandwidth Enhancement in Nanostructured Graphene (2015)

Graphene plasmonic structures with long-range layering periodicity are presented. Resonance energy scaling with the number of graphene layers involved in plasmonic excitation allows these structures to support multiple plasmonic modes that couple and hybridize due to their physical proximity. Hybridized states exhibit bandwidth enhancements of 100-200% compared to unhybridized modes, and resonance energies deviate from what is usually observed in coupled plasmonic systems. Origins of this behavior are discussed, and experimental observations are computationally modeled. This work is a precursor and template for the study of plasmonic hybridization in other two-dimensional material systems with layering periodicity.
Inside Cover: A Touchscreen as a Biomolecule Detection Platform (Angew. Chem. Int. Ed. 3/2012) (2011)

Touchscreen technology could be used for biomolecule detection. In their Communication on page 748 ff., H. G. Park and B. Y. Won describe a detection platform that utilizes a capacitive touchscreen to measure DNA concentration, which could lead the way to personalized portable biosensors.
Facile and eco-friendly extraction of cellulose nanocrystals<i>via</i>electron beam irradiation followed by high-pressure homogenization (2018)

Cellulose nanocrystals were prepared<italic>via</italic>short-time pretreatment by electron-beam irradiation in the solid state and disintegration using high pressure homogenization.
Molecular-dynamics simulation of substituted conjugated ionic polyacetylenes (1993)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMolecular-dynamics simulation of substituted conjugated ionic polyacetylenesStuart B. Clough, Xiao Fang Sun, Sundar Subramanyam, Nagendra Beladakere, Alexandre Blumstein, and Sukant K. TripathyCite this: Macromolecules 1993, 26, 4, 597–600Publication Date (Print):February 1, 1993Publication History Published online1 May 2002Published inissue 1 February 1993https://doi.org/10.1021/ma00056a007Request reuse permissionsArticle Views94Altmetric-Citations14LEARN 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 InReddit PDF (469 KB) Get e-Alertsclose Get e-Alerts
miRNA expression as a predictor of survival in patients with metastatic colorectal cancer treated with EGFR inhibitors. (2012)

e14059 Background: The epidermal growth factor receptor (EGFR) pathway is crucial in the development and progression of human epithelial cancers. EGFR inhibitors have been tested for treatment of a variety of cancers but they are generally plagued by low response rates, leading to ineffective or non-optimal chemotherapy, unnecessary drug toxicity and expense. In colorectal cancer, KRAS mutations are clearly associated with resistance to anti-EGFR antibodies. A major challenge is to identify, in non-mutated KRAS patients, markers that can predict response to this therapy. This study aimed to develop a miRNA expression-based model for evaluating the responsiveness of patients with KRAS wild-type metastatic colorectal cancer to one or more EGFR inhibitors prior to treatment. Methods: miRNA profiling of KRAS wild-type tumors was performed on a discovery set of 44 patients with metastatic colorectal cancer treated with anti-EGFR inhibitors. A miRNA expression-based predictor of survival risk group was calculated by combining a Cox proportional hazards model and a supervised principal component method. Results: miRNA profiling of the discovery set identified hsa-miRNA-31* whose expression in tumor samples was highly correlated with survival and displayed prediction prospective for disease-free and overall survivals. Parameters of the hsa-miRNA-31* expression-based prediction model were determined on a subgroup of 23 patients. Its discriminative ability was evaluated on the complementary 21 samples that included 19 events. In this validation set, 4 of the 6 patients classified as “low risk” by the model survived for more than 25 weeks as disease-free whereas 11 of the 13 patients classified as “high risk” displayed disease progression within 25 weeks, suggesting a specificity of 85% [95% CI: 54%-98%] and a sensitivity of 67% [95% CI: 22%-96%] for the prediction model. These values were associated with a PPV of 67%, [95% CI: 22%-95%] and a NPV of 85% [95% CI: 54%-98%]. Conclusions: Our findings demonstrated that a prediction model based on the level of expression of hsa-miRNA-31* could evaluate whether a patient with a KRAS wild-type metastatic colorectal cancer is likely to respond to an EGFR inhibitor.
MULTISPECTRAL DETECTION OF FECAL CONTAMINATION ON APPLES BASED ON HYPERSPECTRAL IMAGERY: PART I. APPLICATION OF VISIBLE AND NEARINFRARED REFLECTANCE IMAGING (2002)

Fecal contamination of apples is an important food safety issue. To develop automated methods to detect suchcontamination, a recently developed hyperspectral imaging system with a range of 450 to 851 nm was used to examinereflectance images of experimentally contaminated apples. Fresh feces from dairy cows were applied simultaneously as athick patch and as a thin, transparent (not readily visible to the human eye), smear to four cultivars of apples (Red Delicious,Gala, Fuji, and Golden Delicious). To address differences in coloration due to environmental growth conditions, apples wereselected to represent the range of green to red colorations. Hyperspectral images of the apples and fecal contamination siteswere evaluated using principal component analysis with the goal of identifying two to four wavelengths that could potentiallybe used in an online multispectral imaging system. Results indicate that contamination could be identified using either threewavelengths in the green, red, and NIR regions, or using two wavelengths at the extremes of the NIR region underinvestigation. The three wavelengths in the visible and nearinfrared regions offer the advantage that the acquired imagescould also be used commercially for color sorting. However, detection using the two NIR wavelengths was found to be lesssensitive to variations in apple coloration. For both sets of wavelengths, thick contamination could easily be detected usinga simple threshold unique to each cultivar. In contrast, results suggest that more computationally complex analyses, such ascombining threshold detection with morphological filtering, would be necessary to detect thin contamination spots usingreflectance imaging techniques.
Neutron-Stimulated Gamma Ray Measurements for Chlorine Detection (2021)

Applications of neutron-gamma analysis for chlorine determination in different materials (e.g., solids, aqueous solutions, and surface contaminations) are discussed. Solid samples were measured with a pulsed fast/thermal neutron analysis (PFTNA) system consisting of a pulsed neutron generator and sodium iodide gamma detectors and an associated particle imaging (API) system consisting of a neutron generator (with a built-in alpha detector) and sodium iodide gamma detector; all sample measurements were made under similar conditions (neutron flux values and detector-side area for crossing gamma flux). The advantages of PFTNA over the API method were demonstrated based on comparison of metrological parameters (i.e., minimal detectible level for a 1-h measurement period and clock time required to reach 5% measurement accuracy). For these reasons, the PFTNA system in scanning mode effectively identified areas of artificial chlorine contamination in the field. Paired with GPS, a chlorine contamination map was created from PFTNA scanning results; this map accurately identified the actual position and size of chlorine contaminated locations in the field. Chlorine-contaminated areas of ~4.5 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> were effectively located within the ~500 m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> field during a ~2-h scanning period. Based on the results from this work, promising directions for further application of the PFTNA method are disclosure of chlorine contamination in soil and measurements of marine water salinity.
Interference-Free Insertion of a Solid Body Into a Cavity: An Algorithm and a Medical Application (1996)

This article presents a novel algorithm for efficiently computing an interference-free insertion path of a body into a cavity and shows its practical use in the insertability analysis of custom orthopedic hip implants. The algorithm is designed to handle tightly fit, very complex three-dimensional bodies requiring fine, complex, coupled six-degree-of-freedom motions in a preferred direction. It provides a practical method for efficiently handling the geometric complexity of tight-fit insertions. The algorithm computes an insertion path consisting of small interference-free body motion steps. It formulates local, linearized configuration space constraints derived from the shapes and computes suc cessive motion steps by solving a series of linear optimization problems whose solution corresponds to the maximum allowed displacement in a preferred direction satisfying the constraints. It either finds a successful insertion path or a stuck conftgura tion. We demonstrate the algorithm with EXTRACT, a program for analyzing the insertability of cementless custom orthopedic hip implants. EXTRACT computes interference-free insertion paths for tightly fit implant and canal shapes described with 10,000 facets to an accuracy of 0.01 inch in 30 minutes on a workstation. It has been successfully tested on 30 real cases provided by a medical equipment manufacturer.