gebhart/patrepeval huggingface dataset:
Handheld bio-impedance measurement system based on an instrument-on-chip (2011)

In this paper we present a compact system for impedance measurement in the kHz-MHz frequency range with attoFarad resolution. It has been designed to address micro- and nano-scale bio-sensing applications, such as impedimetric flow cytometry or molecular affinity bio-sensors. The core of the detection system is an integrated circuit that features a low noise current amplifier, a two-phase square waveform lock-in detector and two ΣΔ analog-to-digital converters. The CMOS chip is complemented by all the blocks needed to perform spectroscopy measurements, including versatile signal generation, digital processing and PC data transmission. The whole stand-alone system is USB powered and can reach sub-fF resolution in capacitive tracking on a sub-millisecond time scale.
Scale-up of Extrusion Foaming Process for Manufacture of Polystyrene Foams Using Carbon Dioxide (2010)

An initial evaluation of the scalability of extrusion foaming technology is conducted in this thesis. Both lab- and pilot-scale foam extrusion systems along with annular dies and flat dies were used to investigate the effects of extrusion system scale on the foam expansion. The effects of the processing conditions including die temperature and blowing agent content on the volume expansion of extruded polystyrene foams blown with carbon dioxide are presented. A systematic comparison of the effects of extrusion system scale on the expansion behavior of polystyrene foams blown with carbon dioxide at the consistent pressure-drop rate, demonstrated that the scale of the foam extrusion system does not affect the principles of the foaming process, and the effects of extrusion system size on the scale-up of foam techniques, such as shear rate and temperature uniformity, could be suppressed by tailoring the processing conditions and experimental parameters.
Neurotropic Pyrimidine Heterocyclic Compounds. II. Effects of Novel Neurotropic Pyrimidine Derivatives on Astrocytic Morphological Differentiation. (1997)

Astrocytes play an important role in supporting nerve regeneration after brain injuries. In this study, the effects of novel neurotropic synthesized pyrimidine compounds on astrocytic morphological differentiation were examined. Treatment of protoplasmic cultured astrocytes with 2-piperidino-5,6-dihydro-7-methyl-6-oxo(7 H)pyrrolo[2,3-d]pyrimidine maleate (MS-430) and the related compounds caused astrocytic process formation in 60 min. The morphology of MS-430-treated cells was similar to that of dibutyryl cAMP (DBcAMP)-treated cells. The astrocytic process formation by MS-430 was observed within 60 min and the maximum effect was obtained at the drug concentration of 0.5-1.0 mM. Rhodamine-phalloidin staining showed that astrocytic cytoskeletal actin was reorganized by MS-430 and DBcAMP. MS-430 did not increase cAMP accumulation in cultured astrocytes. These results suggest that the neurotropic pyrimidines induced astrocytic morphological differentiation through a cAMP-independent mechanism.
QoS and channel aware packet bundling for VoIP and data traffic in multi-carrier cellular networks (2010)

We study the problem of multiple packet bundling in multi-carrier cellular networks for VoIP and data traffic. In a time-slotted system such as the cdma2000 1xEV-DO downlink, part of a time-slot may not be fully utilized, if the packet sizes are small, as in the case of real-time VoIP traffic. Packet bundling can alleviate such a problem by sharing a time slot among multiple users, as proposed in the EV-DO Revision A system. A recent revision, EV-DO Revision B, enables further increased system capacity through multiple carriers. However, the efficacy of packet bundling, especially across multiple carriers, is not well understood. When packets are bundled, the packet with the lowest channel quality dictates the modulation and coding format of the entire bundle, possibly wasting significant slot space due to unnecessary coding bits for the other packets. We first present how multiple carriers, together with packet bundling, improve spectral efficiency, but lose some of that benefit in realistic channel scenarios. Then we propose an effective heuristic algorithm to effectively exploit the multi-carrier with bundling system. We consider QoS requirements as well as time-varying and user-dependent channel conditions, and then show how channel utilization can be significantly improved while keeping delays of real-time packets limited.
“Oncogenic Shock”: Turning an Activated Kinase against the Tumor Cell (2006)

Accumulating evidence indicates that mutationally activated kinases are especially good targets for anti-cancer drugs. It has been suggested that this reflects a state of "oncogene addiction" of tumor cells. We recently reported experimental studies that may provide a molecular mechanism to explain such apparent dependency. We find that oncogenic kinases produce both pro-survival and pro-apoptotic signals that decay at different rates upon oncogene inactivation. Pro-survival signals are rapidly attenuated, whereas pro-apoptotic signals are relatively longer-lived. This differential signal decay creates a temporal window during which pro-apoptotic outputs from the oncogenic kinase predominate to actively promote tumor cell death upon kinase inhibition. We refer to this mechanism as "oncogenic shock", and suggest that it has significant implications for the optimal therapeutic use of targeted kinase inhibitors.
Enhancing Colorimetric Loop-mediated Isothermal Amplification Speed and Sensitivity with Guanidine Chloride (2020)

Loop-mediated isothermal amplification (LAMP) is a versatile technique for detection of target DNA and RNA, enabling rapid molecular diagnostic assays with minimal equipment. The global SARS-CoV-2 pandemic has presented an urgent need for new and better diagnostic methods, with colorimetric LAMP utilized in numerous studies for SARS-CoV-2 detection. However, the sensitivity of colorimetric LAMP in early reports has been below that of the standard RT-qPCR tests, and we sought to improve performance. Here we report the use of guanidine hydrochloride and combined primer sets to increase speed and sensitivity in colorimetric LAMP, bringing this simple method up to the standards of sophisticated techniques and enabling accurate, high-throughput diagnostics.
Alkyl Derivatives of Iminodiacetic Acid (1955)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAlkyl Derivatives of Iminodiacetic AcidAlvin Stein, Harry P. Gregor, and Paul E. SpoerriCite this: J. Am. Chem. Soc. 1955, 77, 1, 191–192Publication Date (Print):January 1, 1955Publication History Published online1 May 2002Published inissue 1 January 1955https://pubs.acs.org/doi/10.1021/ja01606a069https://doi.org/10.1021/ja01606a069research-articleACS PublicationsRequest reuse permissionsArticle Views343Altmetric-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 InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
A new concept for a realtime feedback system in angioplasty with a flashlamp pumped dye laser (1991)

The feasibility of using a pulsed dye laser in angioplasty for detection and disintegration of calcified plaques was studied in vitro. A flashlamp-pumped dye laser (495 nm, 2 microseconds) was used as the exciting source for laser-induced-fluorescence (LIF) signals. Spectral data in the 520 nm to 800 nm region of normal intima, calcified plaque and fibro-fatty plaques were analyzed with an optical multichannel analyzer, using the same fiber for energy delivery and fluorescence diagnostic. Good signal to noise ratio and different spectra for different specimens were obtained within only 2 microseconds. The spectral difference is caused by selective reabsorption of oxyhemoglobin in the vessel wall. Time resolved LIF-spectroscopy shows that the fluorescence intensity reaches its maximum value before the maximum laser intensity is delivered. Fluorescence analysis can be performed in less than 300 ns and therefore the laser can be controlled before plasma threshold is reached. The described in vitro results can lead to a clinical useful feedbacksystem for energy control of microseconds lasers in angioplasty if the blood interference effects can be minimized by changing the laser excitation wavelength or staining the tissue.
Postsynthesis, Characterization, and Catalytic Properties in Alkene Epoxidation of Hydrothermally Stable Mesoporous Ti-SBA-15 (2002)

Mesoporous Ti-SBA-15 has been postsynthesized by the titanation of pure silica SBA-15 in glycerol with the assistance of quaternary organic ammonium hydroxides, and has been extensively characterized by various techniques to investigate the mesostructural and catalytic properties, and the chemical nature of the incorporated Ti species, in comparison with those of Ti-MCM-41. To incorporate tetrahedral Ti species into the silica walls of SAB-15, the titanation needs to be carried out at elevated temperature and using an optimum amount of organic ammonium hydroxide. Ti-SBA-15 samples with a Si/Ti ratio ranging from 376 to 16 are successfully prepared with the retention of hexagonal mesostructure by elaborately conducting the titanation. The nature of the Ti species depends greatly on the Ti loading. At Si/Ti ratios higher than 50, the Ti species are mainly tetrahedrally coordinated in isolated states, while poorly dispersed Ti species of octahedral coordination are formed at higher Ti incorporation levels; however, no anatase phase is formed in all cases. The IR band at 948 cm-1 due to Si−O−Ti bonds can be used to characterize the tetrahedral Ti species in mesoporous materials, but the techniques of dehydration or trimethylsilylation should be adopted to get rid of the influence of silanol groups. In an actual catalytic reaction, Ti-SBA-15 exhibits not only extremely high thermal stability but also outstanding endurance against Ti leaching not observed for Ti-MCM-41. Ti-SBA-15 is thus presumed to be a promising liquid-phase oxidation catalyst.
Neue Synthese von Aminosäuren aus Halogencarbonsäureestern (1979)

Chemisch synthetisierte α-Aminosäuren als Nahrungs- und Futtermittelzusatz werden schon heute gebraucht. Nachteile früherer Syntheseverfahren lassen sich mit der Reaktionsfolge (1)→ (2)→ (3)→ vermeiden, die z. B. in 52% Gesamtausbeute zu Lysin führt (X = Cl, Br; R1 = Me, Et; M = K, Na, Li).
The collapse of the keyhole in the laser welding of materials (1993)

The collapse time of a keyhole following the extinction of a continuous CO2 laser beam during the process of laser welding is calculated for a variety of processing conditions. It is assumed that in a period of time much shorter than the collapse time of the keyhole the pressure in the keyhole drops to the ambient atmospheric pressure outside. The initial keyhole geometry is calculated using the integrated model of Ducharme et al (1992). It is argued that the keyhole collapses as a result of the considerable surface tension forces operating in the keyhole wall. The boundary condition for the pressure on the keyhole wall at the mouth of the keyhole is the ambient atmospheric pressure and an additional tangential contribution arises from the surface tension forces operating on the keyhole wall. The radial velocity of the keyhole wall is calculated as a function of time and the collapse time of the keyhole is then deduced knowing the initial keyhole radius from the model of Ducharme et al. (1993). In calculating the collapse time of the keyhole a full numerical solution for the three-dimensional time-dependent velocity field in the weld pool is obtained using the finite difference method. This work represents an extension of previous work in this area carried out by Kroos, Gratzke, Vicanek and Simon (1993). The results of the calculation are discussed in relation to the analysis of infrared and ultraviolet sensor data from the keyhole and the weld pool given by Kapadia et al. (1992). The understanding so gained will be of value in clarifying the radiative spectrum produced by the keyhole and will be of additional practical help in the use of radiative sensors to monitor laser welding. It will, furthermore, also provide insight into the behaviour of the keyhole when pulsed lasers are used to carry out laser welding.
Low coupling losses in YBa2Cu3O7 coated conductors with current sharing between the superconducting stripes (2007)

The authors calculate the coupling losses in striated YBa2Cu3O7 coated conductors covered partially with normal conducting layers in the form of segmented pieces, connecting the individual superconducting stripes. The authors propose a system of coating that fulfills the requirements of both acceptable coupling losses and sufficient current sharing between the stripes. This structure can be used in ac applications without twisting the superconducting stripes. The frequency range, in which the model and the calculations can be applied, is also given.
Zero DC offset active RC filter designs. (2008)

A class of RC active filters in which the DC offset of the operational amplifier (op-amp) is completely absent from the filter output [1]. Individual filter configurations (Low Pass, High Pass, Band Pass, Band Stop, All Pass) are discussed and corresponding transfer functions are defined. The effects of op-amp gain bandwidth product on filter responses are accounted for and presented in a table. In order to understand the upper limit of dynamic responses, maximum signal magnitude and corresponding frequency of maximum magnitude are calculated. The effects of noise generating components are defined and included, thus establishing the lower limit of dynamic responses for all filter configurations. Step-by-step design procedures are given for most common filter configurations. Sample filters are designed based on chosen values for critical frequency ù 0 and filter quality factor Q. Filter schematics are captured and their frequency responses are simulated using circuit simulation software. Sample filters are built and their frequency responses are confirmed using a network analyzer. Extension to higher order filters is discussed and demonstrated.
Thoughts beyond words: When language overshadows insight. (1993)

Four experiments examined whether verbalization can interfere with insight problem solving. In Experiment 1, Ss were interrupted during problem solving and asked either to verbalize their strategies (retrospective verbalization) or engage in an unrelated activity (control). Ss in the retrospective verbalization condition were significantly less successful than control subjects at solving the problems. Experiment 2 replicated the finding of Experiment 1 and demonstrated that the control Ss' advantage was not due to any beneficial effect of the interruption. In Experiment 3, concurrent, nondirective verbalization impaired the solving of insight problems but had no effect on noninsight problems. In Experiment 4, the effect of concurrent verbalization on insight was maintained even when Ss were encouraged to consider alternative approaches. Together, these findings are consistent with the hypothesis that verbalization can result in the disruption of nonreportable processes that are critical to achieving insight solutions.
Binding of Mg<sup>2+</sup> and Ca<sup>2+</sup> to Palmitic Acid and Deprotonation of the COOH Headgroup Studied by Vibrational Sum Frequency Generation Spectroscopy (2010)

At the air/liquid interface, cation binding specificity of alkaline earth cations, Mg(2+) and Ca(2+), with the biologically relevant ligand carboxylate (COO(-)) using vibrational sum frequency generation spectroscopy is reported. The empirical evidence strongly supports that the ionic binding strength is much stronger for Ca(2+) to COO(-) than that for Mg(2+). We conclude that at a near-neutral pH, the mechanism that governs Ca(2+) binding to COO(-) is accompanied by commensurate deprotonation of the carboxyl headgroup. In addition, surface molecular structure and ion concentration influence the cation binding behavior at the air/liquid interface. In a 0.1 M Ca(2+)(aq) solution, Ca(2+) initially favors forming ionic complexes in a 2:1 bridging configuration (2Ca(2+):1COO(-)) but 1:1 chelating bidentate complexes (1Ca(2+):1COO(-)) gradually emerge as secondary species as the system reaches equilibrium. As the Ca(2+) concentration rises to 0.3 M, the primary complexed species exists in the 2:1 bridging configuration. Unlike Ca(2+), Mg(2+) at 0.1 and 0.3 M favors a solvent-separated ionic complex with COO(-).
An Adaptive IHS Pan-Sharpening Method (2010)

The goal of pan-sharpening is to fuse a low spatial resolution multispectral image with a higher resolution panchromatic image to obtain an image with high spectral and spatial resolution. The Intensity-Hue-Saturation (IHS) method is a popular pan-sharpening method used for its efficiency and high spatial resolution. However, the final image produced experiences spectral distortion. In this letter, we introduce two new modifications to improve the spectral quality of the image. First, we propose image-adaptive coefficients for IHS to obtain more accurate spectral resolution. Second, an edge-adaptive IHS method was proposed to enforce spectral fidelity away from the edges. Experimental results show that these two modifications improve spectral resolution compared to the original IHS and we propose an adaptive IHS that incorporates these two techniques. The adaptive IHS method produces images with higher spectral resolution while maintaining the high-quality spatial resolution of the original IHS.
Tag-Based Image Retrieval Improved by Augmented Features and Group-Based Refinement (2012)

In this paper, we propose a new tag-based image retrieval framework to improve the retrieval performance of a group of related personal images captured by the same user within a short period of an event by leveraging millions of training web images and their associated rich textual descriptions. For any given query tag (e.g., “car”), the inverted file method is employed to automatically determine the relevant training web images that are associated with the query tag and the irrelevant training web images that are not associated with the query tag. Using these relevant and irrelevant web images as positive and negative training data respectively, we propose a new classification method called support vector machine (SVM) with augmented features (AFSVM) to learn an adapted classifier by leveraging the prelearned SVM classifiers of popular tags that are associated with a large number of relevant training web images. Treating the decision values of one group of test photos from AFSVM classifiers as the initial relevance scores, in the subsequent group-based refinement process, we propose to use the Laplacian regularized least squares method to further refine the relevance scores of test photos by utilizing the visual similarity of the images within the group. Based on the refined relevance scores, our proposed framework can be readily applied to tag-based image retrieval for a group of raw consumer photos without any textual descriptions or a group of Flickr photos with noisy tags. Moreover, we propose a new method to better calculate the relevance scores for Flickr photos. Extensive experiments on two datasets demonstrate the effectiveness of our framework.
N-Benzylation of phthalimide under the catalytic action of A1_2O_3 supported KF reagent (2003)

N-benzylation of phthalimide was carried out under the catalytic action of Al2O3 supported KF reagent. Various reaction factors affecting the yield have been studied. The optimal reaction conditions were,phthalimide and benzyl bromide molar ratio 1 :1. 2,reaction temperature 90℃ .reaction time 6h in DMF. The yield of N-benzy-lation of phthalimide was 92. 5%.
Visualizing High‐Dimensional Structures by Dimension Ordering and Filtering using Subspace Analysis (2011)

Abstract High‐dimensional data visualization is receiving increasing interest because of the growing abundance of high‐dimensional datasets. To understand such datasets, visualization of the structures present in the data, such as clusters, can be an invaluable tool. Structures may be present in the full high‐dimensional space, as well as in its subspaces. Two widely used methods to visualize high‐dimensional data are the scatter plot matrix (SPM) and the parallel coordinate plot (PCP). SPM allows a quick overview of the structures present in pairwise combinations of dimensions. On the other hand, PCP has the potential to visualize not only bi‐dimensional structures but also higher dimensional ones. A problem with SPM is that it suffers from crowding and clutter which makes interpretation hard. Approaches to reduce clutter are available in the literature, based on changing the order of the dimensions. However, usually this reordering has a high computational complexity. For effective visualization of high‐dimensional structures, also PCP requires a proper ordering of the dimensions. In this paper, we propose methods for reordering dimensions in PCP in such a way that high‐dimensional structures (if present) become easier to perceive. We also present a method for dimension reordering in SPM which yields results that are comparable to those of existing approaches, but at a much lower computational cost. Our approach is based on finding relevant subspaces for clustering using a quality criterion and cluster information. The quality computation and cluster detection are done in image space, using connected morphological operators. We demonstrate the potential of our approach for synthetic and astronomical datasets, and show that our method compares favorably with a number of existing approaches.
Tentative Identification of the Second Substrate Binding Site in Arabidopsis Phytochelatin Synthase (2013)

Phytochelatin synthase (PCS) uses the substrates glutathione (GSH, γGlu-Cys-Gly) and a cadmium (Cd)-bound GSH (Cd∙GS2) to produce the shortest phytochelatin product (PC2, (γGlu-Cys)2-Gly) through a ping-pong mechanism. The binding of the 2 substrates to the active site, particularly the second substrate binding site, is not well-understood. In this study, we generated a structural model of the catalytic domain of Arabidopsis AtPCS1 (residues 12-218) by using the crystal structure of the γGlu-Cys acyl-enzyme complex of the PCS of the cyanobacterium Nostoc (NsPCS) as a template. The modeled AtPCS1 revealed a cavity in proximity to the first substrate binding site, consisting of 3 loops containing several conserved amino acids including Arg152, Lys185, and Tyr55. Substitutions of these amino acids (R152K, K185R, or double mutation) resulted in the abrogation of enzyme activity, indicating that the arrangement of these 2 positive charges is crucial for the binding of the second substrate. Recombinant AtPCS1s with mutations at Tyr55 showed lower catalytic activities because of reduced affinity (3-fold for Y55W) for the Cd∙GS2, further suggesting the role of the cation-π interaction in recognition of the second substrate. Our study results indicate the mechanism for second substrate recognition in PCS. The integrated catalytic mechanism of PCS is further discussed.