gebhart/patrepeval huggingface dataset:
Full-field digital gradient sensing method for evaluating stress gradients in transparent solids (2012)

A full-field digital gradient sensing method is proposed for measuring small angular deflections of light rays due to local stresses in transparent planar solids. The working principle of the method is explained, and the governing equations are derived. The analysis shows that angular deflections of light rays can be linked to nonuniform changes in thickness and refractive index of the material. In mechanically loaded planar solids, the angular deflections can be further related to spatial gradients of first invariant of stresses under plane stress conditions. The proposed method is first demonstrated by capturing the angular deflection fields in two orthogonal directions for a thin plano-convex lens. The measured contours of constant angular deflection of light rays are in good agreement with the expected ones for a spherical wavefront. The method is also successfully implemented to study a stress concentration problem involving a line load acting on an edge of a large planar sheet. Again, the stress gradients, measured simultaneously along and perpendicular to the loading directions, are in good agreement with the analytical predictions. The measured stress gradients have also been used to estimate stresses in the load point vicinity where plane stress results hold.
A Subgraph Operator for Graph Transformation Languages (2024)

In practical applications of graph transformation techniques to model transformations one often has the need for copying, deleting, or moving entire subgraphs that match a certain graph pattern. While this can be done using elementary node and edge operations, the transformation is rather cumbersome to write. To simplify the transformation, we have recently developed a novel approach that allows selecting subgraphs from the matched portion of the host graph, applying a filter condition to the selection, and performing a delete, move, or copy operation on the filtered result in the context of a transformation rule. The approach has been implemented in the GReAT language and tested on examples that show the practical efficacy of the technique. The paper describes the technique in detail and illustrates its use on a real-life example.
Aging of Hydrogenated and Oxidized Diamond (2009)

Single-molecule force spectroscopy experiments demonstrate that hydrogenation and oxidation of polycrystalline diamond effectively control molecular adhesion (see figure). Aging changes these properties and originates from the rapid formation of a thin and resistant contamination layer, as well as degradation of the artificial surface termination on longer time scales. This aging also affects the wettability, morphology, and the electrical properties of the surfaces. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Design of demodulators using time-varying adaptive digital filters (2002)

A discussion is presented of the design of time-varying adaptive digital filters used for amplitude-shift keying (ASK), frequency-shift keying (FSK), and phase-shift keying (PSK) demodulation in communication systems. It is shown that these time-varying time domain algorithms require less computations and hence are more efficient than frequency domain algorithms. An efficient inversion technique is exploited in these time domain formulations. Simulations are presented and discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Expression and site-directed mutagenesis of human protein disulfide isomerase in Escherichia coli. This multifunctional polypeptide has two independently acting catalytic sites for the isomerase activity. (1992)

Protein disulfide isomerase (PDI, EC 5.3.4.1) is a highly unusual multifunctional polypeptide, being identical to the beta subunit of prolyl 4-hydroxylase, a cellular thyroid hormone binding protein and a component of the microsomal triglyceride transfer protein complex, and highly similar to a polypeptide acting in vitro as a glycosylation site binding protein. It has two -Cys-Gly-His-Cys- sequences which, it has been proposed, act as catalytic sites for the isomerase activity, but few data have been available to indicate whether one or both of them do indeed act as catalytic sites and whether the two presumed catalytic sites act independently or cooperatively. We report here on the expression of human PDI in Escherichia coli with three different signal sequences. All three polypeptide variants were secreted into the periplasmic space as fully active enzymes. Oligonucleotide-directed mutagenesis was used to convert either one or both of the -Cys-Gly-His-Cys- sequences to -Ser-Gly-His-Cys-. The PDI activity of both polypeptides containing a single modified sequence was about 50% of that of the wild-type polypeptide, whereas the polypeptide with two modified sequences had no isomerase activity. It is thus concluded that both -Cys-Gly-His-Cys- sequences act as catalytic sites for the isomerase activity, and the two catalytic sites appear to operate independently of one another.
Comparison ofbax,waf1, and IMP dehydrogenase regulation in response to wild-type p53 expression under normal growth conditions (1998)

Recently, we demonstrated that downregulation of inosine-5'-monophosphate dehydrogenase (IMPD; IMP:NAD oxidoreductase, EC 1.2.1.14), the rate-limiting enzyme for guanine nucleotide biosynthesis, is required for p53-dependent growth suppression. These studies were performed with cell lines derived from immortal, nontumorigenic fibroblasts that express wild-type p53 conditionally by virtue of a metal-responsive promoter. Here, the p53-dependent properties of the original "p53-inducible" fibroblasts are presented in detail and compared to related properties of epithelial cells that also express wild-type p53 conditionally, but by virtue of a temperature-responsive promoter. Both types of p53-inducible cells were designed to approximate normal physiologic relationships between the host cell and the regulated p53 protein. Together, they were used to investigate expression relationships between IMPD and other p53-responsive genes proposed as mediators of p53-dependent growth suppression. In both types of cells, IMPD activity, protein, and mRNA were consistently coordinately reduced in response to p53 expression. In contrast, mRNAs for waf1, bax, and mdm2 showed disparate patterns of expression, being induced in one conditional cell type, but not the other. This distinction in regulation pattern suggests that under normal growth conditions, unlike IMPD downregulation, bax and waf1 induction is not a rate-determining event for p53-dependent growth suppression.
Optical add-drop multiplexers based on the antisymmetric waveguide Bragg grating (2006)

A novel optical add-drop multiplexer (OADM) based on a null coupler with an antisymmetric grating was designed and experimentally demonstrated. The antisymmetric grating exclusively produces a reflection with mode conversion in a two-mode waveguide. This improves the performance compared with previous demonstrations that used tilted Bragg gratings. Our design minimizes noise and cross talk produced by reflection without mode conversion. In addition, operational bandwidth and, versatility are improved while the compactness and simplicity of the null coupler OADM are maintained.
A thrombin-based peptide corresponding to the sequence of the thrombomodulin-binding site blocks the procoagulant activities of thrombin. (1991)

Thrombomodulin, a cofactor in the thrombin-catalyzed activation of protein C, blocks the procoagulant activities of thrombin such as fibrinogen clotting, Factor V activation, and platelet activation. The binding site for thrombomodulin within human thrombin has been localized at a region comprising residues Thr147-Ser158 of the B-chain of thrombin. The dodecapeptide sequence, TWTANVGKGQPS, corresponding to these residues inhibits thrombin binding to thrombomodulin with an apparent Ki = 94 microM (Suzuki, K., Nishioka, J., and Hayashi, T. (1990) J. Biol. Chem. 265, 13263-13267). We have found that the inhibitory effect of the dodecapeptide on the thrombin-thrombomodulin interaction is sequence-specific, and that residues Asn151, Lys154, and Gln156 are essential for thrombomodulin binding. The dodecapeptide was also found to directly block thrombin procoagulant activities, fibrinogen clotting (concentration for half-maximum inhibition, 385 microM). Factor V activation (concentration for half-maximum inhibition, 33 microM), and platelet activation (concentration for half-maximum inhibition, 645 microM). This peptide did not block thrombin inhibition by antithrombin III, but blocked thrombin inhibition by hirudin. These findings suggest that the binding site for thrombomodulin in thrombin is shared with the sites for fibrinogen, Factor V, platelets, and hirudin, and that, therefore, the inhibition of thrombin procoagulant activities by thrombomodulin in part results from blocking of the interaction between thrombin and the procoagulant protein substrates by thrombomodulin.
Automatic detection of ST-T complex changes on the ECG using filtered RMS difference series: application to ambulatory ischemia monitoring (2000)

A new detector is presented which finds changes in the repolarization phase (ST-T complex) of the cardiac cycle. It operates by applying a detection algorithm to the filtered root mean square (rms) series of differences between the beat segment (ST segment or ST-T complex) and an average pattern segment. The detector has been validated using the European ST-T database, which contains ST-T complex episodes manually annotated by cardiologists, resulting in sensitivity/positive predictivity of 85/86%, and 85/76%, for ST segment deviations and ST-T complex changes, respectively. The proposed detector has a performance similar to those which have a more complicated structure. The detector has the advantage of finding both ST segment deviations and entire ST-T complex changes thereby providing a wider characterization of the potential ischemic events. A post-processing stage, based on a cross-correlation analysis for the episodes in the rms series, is presented. With this stage subclinical events with repetitive pattern were found in around 20% of the recordings and improved the performance to 90/85%, and 89/76%, for ST segment and ST-T complex changes, respectively.
Fusing diverse monitoring algorithms for robust change detection (2006)

Change detection is an important task in remotely monitoring and diagnosing equipment and other processes. Specifically, early detection of differences that indicate abnormal conditions has the promise to provide considerable savings in averting secondary damage and preventing system outage. Of course, accurate early detection has to be balanced against the successful rejection of false positive alarms. In noisy environments, such as aircraft engine monitoring, this proves to be a difficult undertaking for any one algorithm. In this paper, we investigate the performance improvement that can be gained by aggregating the information from a set of diverse change detection algorithms. Specifically, we examine a set of change detectors that utilize a variety of different techniques such as neural nets, random forests, and support vector machines. The different techniques have different detection sensitivities and different regression technique that operates well for time series as well as averaging schemes, and a meta-classifiers. We provide results using illustrative examples from aircraft engine monitoring.
A comparison study of low bit rate DE-QPSK and TCM 8-PSK fully digital demodulators over a land mobile satellite link (2002)

The synchronization and detection techniques used to overcome the Rician channel impairments are described. The acquisition and bit error rate (BER) performances of this modem have been evaluated by computer simulation over an AWGN (additive white Gaussian noise) and a Rician faded channel, and compared with a DE-QPSK demodulator with similar architecture. In an AWGN channel the TCM (trellis coded modulation) 8-PSK system is found superior to the DE-QPSK. In terms of the overall BER over realistic satellite channel conditions the two systems show comparable results because of the greater susceptibility of TCM schemes to carrier synchronization errors. However, the outage of the coded 8-PSK system is superior to the DE-QPSK one. The errors of the coded 8-PSK are characterized by short periods of high error rates with longer gaps of very low error rates. In contrast, the errors of the DP-QPSK system are distributed uniformly and occur more frequently.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Trimetrexate: molecular structures and conformational similarities in two crystal forms. (1988)

The structure of the non-classical quinazoline antifolate trimetrexate (TMQ) has been determined in two crystal forms, TMQ acetate monohydrate, and hydrated TMQ free base. Trimetrexate has an extended conformation in both structures, and the quinazoline and phenyl rings are mutually perpendicular. Protonation occurs at N1 in the acetate salt. The TMQ conformation is similar to corresponding parts of quinespar, the only other quinazoline antifolate structurally determined, and the hydrated strontium salt of methotrexate.
Differential effects of antibodies to Lyt-2 and L3T4 on cytolysis by cloned, Ia-restricted T cells expressing both proteins. (1987)

Cloned T cell lines specific for the antigen ovalbumin (OVA) in the context of self I-A or I-E class II MHC-encoded molecules were found to express equivalent levels of the Lyt-2 and L3T4 surface molecules by FACS analysis. Functionally, these cloned T cell lines will kill OVA-pulsed, class II MHC-bearing B lymphoma cells. This system allowed us to examine the relative contribution of the Lyt-2 and L3T4 molecules to recognition of antigen in the context of self class II MHC molecules. We find that anti-L3T4 is 25- to 100-fold more potent at inhibiting cytotoxicity by these cloned lines than is anti-Lyt-2, where potency is calculated as the ratio of the concentration needed for inhibition divided by the concentration needed for binding. Both antibodies can completely inhibit cytotoxicity. These results suggest that the accessory molecules Lyt-2 and L3T4 can play two different roles in antigen:MHC recognition. In class II MHC recognition, L3T4 plays a dominant role, highly sensitive to inhibition by anti-L3T4. By contrast, Lyt-2 plays a minor yet important role in the cell interaction, perhaps by adhesion strengthening. Previous analysis in several laboratories supports the concept that the ligand for L3T4 is class II MHC, whereas the ligand for Lyt-2 is class I MHC. The present results are consistent with the hypothesis that these molecules are actually part of the T cell antigen:MHC recognition complex, and play an important role in the class of MHC molecule recognized by a T cell alpha:beta heterodimeric receptor. As such, they are not accessory proteins, but a direct part of the recognition apparatus, and the term accessory protein may apply only in those cases in which the specificity of the T cell receptor is for a different class of MHC than that normally associated with the L3T4 or Lyt-2 molecule.
Enhanced generation of twin single-photon states via quantum interference in parametric down-conversion: Application to two-photon quantum photolithography (2003)

Two-photon interferometric quantum photon lithography for light of wavelength \ensuremath{\lambda} is capable of beating the Rayleigh diffraction limit of resolution \ensuremath{\lambda}/4 to the level of \ensuremath{\lambda}/8. The required twin single-photon states $|1{〉}_{a}|1{〉}_{b},$ which are converted into maximally entangled states by a 50:50 beam splitter, can be generated from a nondegenerate parametric amplifier initially in vacuum states and with a weak pump field. Increasing the pump strength can slightly increase the production rate of the desired state and it will also increase the production of the twin two-photon states $|2{〉}_{a}|2{〉}_{b},$ which leads to an unwanted background term. In this paper we show that, assuming a weak pair coherent state as input to the amplifier, quantum interference can be used to quench the production of the $|2{〉}_{a}|2{〉}_{b}$ state and to enhance the production of the $|1{〉}_{a}|1{〉}_{b}$ state by almost sixfold.
Comparison of surface EMG monitoring electrodes for long-term use in rehabilitation device control (2009)

In this paper different types of electrodes for long-term surface EMG recording are compared to a reference electrode that is established for clinical use. The electrode materials include four different polymers with conductive load and a fabric of threads coated by a conductive layer. Different criteria are used to evaluate surface EMG recording: the signal quality, including signal-to-noise (SNR) ratio, and impedance in long-term monitoring. The aim of the study is to find an EMG electrode that allows for both silicone liner and textile integration for control of rehabilitation devices for quadriplegics with a partial residual function of the upper limb and for multifunctional prosthetic hands. Besides electrical properties, the biocompatibility and the wearing comfort have to be considered to achieve a wide acceptance by the patients. Except for one evaluated electrode, the signal quality of the four different surface electrodes is comparable to commercial Ag/AgCl gel electrodes in long-term monitoring.
Upstream DNA sequences required for tissue-specific expression of the HLA-DR alpha gene. (1987)

We have used in vitro deletion mutagenesis in combination with DNA transfection to search for cis-acting regulatory elements involved in the tissue-specific expression of a human class II major histocompatibility complex gene. A 140-base-pair 5' flanking fragment that contains the class II box consensus sequences and an octamer sequence (ATTTGCAT) confers tissue specificity on the promoter of the HLA-DR alpha gene. Recombinant DNA plasmids containing this DR alpha gene segment fused to the coding sequence of the bacterial chloramphenicol acetyltransferase gene are expressed at higher levels in human B-cell lines than in human T-cell lines. We have demonstrated that the most 5' of the class II boxes is essential for tissue-specific DR alpha promoter function. In addition, using an electrophoretic mobility shift assay to identify DNA binding proteins, we have detected binding of nuclear proteins to DNA probes containing the class II boxes and the octamer sequence. A protein that binds to the octamer is present at higher levels in nuclear extracts of B-cell lines than in other cell lines examined. This protein may be important for the tissue-specific expression of the HLA-DR alpha gene.
Bispectral Index Monitoring during Sedation with Sevoflurane, Midazolam, and Propofol (2001)

Individual BIS scores demonstrate significant variability, making it difficult to predict sedation depth. The relation between BIS and sedation depth may not be independent of anesthetic agent. Quality of recovery was similar between drugs, but excitement occurred frequently with sevoflurane.
Determination of the Concentration of Single-Walled Carbon Nanotubes in Aqueous Dispersions Using UV−Visible Absorption Spectroscopy (2006)

Stable, homogeneous, aqueous dispersions of single-walled carbon nanotubes (SWNTs) are prepared by nonspecific physical adsorption of surfactants enhanced by sonication. Upon centrifugation, supernatant and precipitate phases are obtained. The initial weights of the SWNTs and the surfactant are divided between these two phases, and the respective SWNT concentration in each phase is unknown. The focus of this work is on the determination of the true concentration of raw, exfoliated HiPCO SWNTs in the supernatant phase. A UV-visible absorption-based approach is suggested for a direct measurement of the SWNT and the surfactant concentration in the supernatant. UV-visible absorbance spectra of SWNTs-surfactant dispersions and surfactants alone reveal that the intensity of a certain peak, attributed to the pi-plasmon resonance absorption, is unaffected by the presence of most surfactants. A calibration plot is then made by monitoring the intensity of the peak as a function of the true concentration of the exfoliated SWNTs. Thus, we are able to determine the unknown concentration of surfactant-dispersed HiPCO SWNTs in the supernatant solution, simply by measuring its optical absorbance. Moreover, we can now calculate the surfactant efficiency in dispersing SWNTs. Cryogenic-transmission electron microscopy and thermogravimetric analysis techniques are used for the characterization of these dispersions and to complement the UV-visible measurements.
The<i>In Vivo</i>and<i>In Vitro</i>Conversion of Testosterone to 17β-Hydroxy-5α-Androstan-3-One (Dihydrotestosterone) by the Sebaceous Gland of Hamsters (1972)

We studied the in vivo and in vitro conversion of testosterone to dihydrotestosterone in sebaceous glands microdissected from the costovertebral glands of Syrian hamsters. After the intraperitoneal injection of testosterone- 1,2-3H, dihydrotestosterone was the major radioactive steroid not only in the sebaceous glands but also in the prostate and seminal vesicles. On the other hand, other nontarget organs and the plasma contained very little or no radioactive dihydrotestosterone. Using the newly devised micromethod for 5α-reductase assay with 15 to 25 μg of tissue samples, we found that the sebaceous glands contained sufficient 5α-reductase activity to convert in vivo testosterone to dihydrotestosterone. After castration, the uptake of radioactive dihydrotestosterone after the injection of testosterone- 1,2-3H in the sebaceous glands rapidly decreased, whereas the 5α-reductase activity on a dry tissue weight basis steadily increased. The endogenous level of TPNH, which is essential for 5α-reduction, decre...
Synthesis of the bulky <i>m</i>-terphenyl phenol Ar*OH (Ar* = C<sub>6</sub>H<sub>3</sub>-2,6-Mes<sub>2</sub>, Mes = 2,4,6-trimethylphenyl) and the preparation and structural characterization of several of its metal complexes (2008)

The bulky m-terphenyl phenol Ar*OH 1 (Ar* = C 6 H 3 -2,6-Mes 2 , Mes = 2,4,6-trimethylphenyl) was synthesized via the treatment of Ar*Li with nitrobenzene. The phenol 1 is prepared in modest to good yield using this method. Attempts were also made to prepare 1 through oxidation of the bulky boronic acid Ar*B(OH) 2 with Oxone ® , but this reaction was not suitable for preparative-scale reactions. Side products of the reaction between Ar*Li and nitrobenzene were identified as Ar*[N(O)Ph] and [C 6 H 5 N(O)] 2 and were characterized by X-ray crystallography and EPR spectroscopy. A variety of main-group and transition-metal complexes of Ar*OH were prepared, namely Sn(OAr*) 2 , Ge(OAr*) 2 , [N(SiMe 3 ) 2 ]Ge(OAr*), [Me 2 Al(OAr*)] 2 , and Ti(NMe 2 )(OAr*) 2 . All compounds were characterized spectroscopically and most were studied by single-crystal X-ray diffraction as well.Key words: m-terphenyl, main-group compounds, X-ray crystallography, multinuclear NMR spectroscopy, EPR spectroscopy.