gebhart/patrepeval huggingface dataset:
Synthesis, Properties, and Pharmacokinetic Studies of N2-Phenylguanine Derivatives as Inhibitors of Herpes Simplex Virus Thymidine Kinases (1995)

Two series of selective inhibitors of herpes simplex virus types 1 and 2 (HSV1,2) thymidine kinases (TK) have been developed as potential treatment of recurrent virus infections. Among compounds related to the potent base analog N2-[m-(trifluoromethyl)phenyl]guanine (mCF3-PG), none was a more potent inhibitor than mCF3PG itself. Compounds related to the nucleoside N2-phenyl-2'-deoxyguanosine (PhdG), but with alkyl, hydroxyalkyl, and related substituents at the 9-position in place of the glycosyl group of PhdG, retained significant but variable inhibitory potencies against the HSV TKs. The most potent inhibitor of HSV1 TK among 9-substituted derivatives, 9-(4-hydroxybutyl)-N2-phenylguanine (HBPG), was a competitive inhibitor with respect to the substrate thymidine but was not itself a substrate for the enzyme. Water solubilities and 1-octanol:water partition coefficients for the 9-substituted N2-phenylguanines were linearly but oppositely related to the sum of hydrophobic fragmental constants (sigma f) of the 9-substituents. Four of the inhibitors were given as solutions to mice by iv and ip routes, and the time course of their plasma concentrations was determined by HPLC analysis of the parent compounds. HBPG was completely absorbed by the ip route, and the plasma concentration could be prolonged by use of suspension formulations. HBPG is a candidate for animal trials of the ability of TK inhibitors to prevent recurrent herpes virus infections.
Electrochemical Corrosion and In Vitro Bioactivity of Nano-Grained Biomedical Ti-20Nb-13Zr Alloy in a Simulated Body Fluid (2017)

The bioactivity and the corrosion protection for a novel nano-grained Ti-20Nb-13Zr at % alloy were examined in a simulated body fluid (SBF). The effect of the SPS’s temperature on the corrosion performance was investigated. The phases and microstructural details of the developed alloy were analyzed by XRD (X-ray Diffraction), SEM (Scanning Electron Microscopy), and TEM (Transmission Electron Microscope). The electrochemical study was investigated using linear potentiodynamic polarization and electrochemical impedance spectroscopy in a SBF, and the bioactivity was examined by immersing the developed alloy in a SBF for 3, 7, and 14 days. The morphology of the depositions after immersion was examined using SEM. Alloy surface analysis after immersion in the SBF was characterized by XPS (X-ray Photoelectron Spectroscopy). The results of the bioactivity test in SBF revealed the growth of a hydroxyapatite layer on the surface of the alloy. The analysis of XPS showed the formation of protective oxides of TiO2, Ti2O3, ZrO2, Nb2O5, and a Ca3(PO4)2 compound (precursor of hydroxyapatite) deposited on the alloy surface, indicating that the presented alloy can stimulate bone formation. The corrosion resistance increased by increasing the sintering temperature and the highest corrosion resistance was obtained at 1200 °C. The improved corrosion protection was found to be related to the alloy densification. The bioactivity and the corrosion resistance of the developed nanostructured alloy in a SBF renders the nanostructured Ti-20Nb-13Zr alloy a promising candidate as an implant material.
Synthesis of Ciguatoxin (CTX1B) (2006)

This awesome synthesis of ciguatoxin features the use of a thioether group to (a) promote linkage of fragments A and B via the formation of an O,S-acetal C and (b) serve as a radical precursor in the cyclization of D to E.
3D Analytic Cone‐Beam Reconstruction for Multiaxial CT Acquisitions (2009)

A conventional 3rd generation Computed Tomography (CT) system with a single circular source trajectory is limited in terms of longitudinal scan coverage since extending the scan coverage beyond 40 mm results in significant cone-beam artifacts. A multiaxial CT acquisition is achieved by combining multiple sequential 3rd generation axial scans or by performing a single axial multisource CT scan with multiple longitudinally offset sources. Data from multiple axial scans or multiple sources provide complementary information. For full-scan acquisitions, we present a window-based 3D analytic cone-beam reconstruction algorithm by tessellating data from neighboring axial datasets. We also show that multi-axial CT acquisition can extend the axial scan coverage while minimizing cone-beam artifacts. For half-scan acquisitions, one cannot take advantage of conjugate rays. We propose a cone-angle dependent weighting approach to combine multi-axial half-scan data. We compute the relative contribution from each axial dataset to each voxel based on the X-ray beam collimation, the respective cone-angles, and the spacing between the axial scans. We present numerical experiments to demonstrate that the proposed techniques successfully reduce cone-beam artifacts at very large volumetric coverage.
Detecting hunts in wildlife videos (2003)

The propose a three-level algorithm to detect animal hunt events in wildlife documentaries. The first level extracts texture, color and motion features, and detects motion blobs. The mid-level employs a neural network to verify the relevance of the detected motion blobs using the extracted color and texture features. This level also generates shot summaries in terms of intermediate-level descriptors which combine low-level features from the first level and contain results of mid-level, domain specific inferences made on the basis of shot features. The shot summaries are then used by a domain-specific inference process at the third level to detect the video segments that contain hunts.
Synthetic and Mechanistic Studies on the Azabicyclo[7.3.1]enediyne Core and Naphtho[2,3-<i>h</i>]quinoline Portions of Dynemicin A (1997)

The synthesis of the 13-keto-10-azabicyclo[7.3.1]enediyne core structure of dynemicin A has been achieved by two routes, Schemes 4 and 6. The chemistry of the 13-keto core structure is dominated by the unusually facile bridgehead enolization. Comparison of the rates of cycloaromatization of a variety of enediynes revealed that substantial rate differences occurred even though the distance between the bonding acetylenes was virtually identical. A non-radical cycloaromatization pathway, initiated by thiol addition to the enediyne system, was discovered, and the simple core amine 26 exhibits modest in vitro and in vivo antitumor activity. Finally, two methods for the synthesis of the naphtho[2,3-h]quinoline portion of dynemicin A are described, and both these compounds also exhibit antitumor activity.
InP-Based Monolithic Photonic Integrated Devices (2009)

We present our recent work on monolithically integrated devices comprising a variety of functional elements such as high speed optical transmitters and receivers, electro-absorption modulators integrated with tunable dispersion compensators and fast-tunable wavelength converters.
<title>Real Time Interferogram Simulation</title> (1979)

An electronic analog device has been constructed which displays synthesized interferograms on a cathode-ray tube (CRT) for real time viewing. First- and third-order aberrations are generated individually or in combination. The exact amount of each aberration (in waves) appearing in the simulated interferogram is also displayed. A radial line cursor adjustable over 360 degrees in the artificial exit pupil provides profile information about the wavefront along the vector. A 3-D presentation of the wavefront is also included.
Comb offset frequency measurement using two-photon—three-photon quantum interference control (2017)

Using the directional photocurrent induced by quantum interference between two- and three-photon absorption in a semiconductor (AlGaAs), we measure the comb offset frequency of a mode-lock fiber laser.
Piezoelectric materials mimic the function of the cochlear sensory epithelium (2011)

Cochlear hair cells convert sound vibration into electrical potential, and loss of these cells diminishes auditory function. In response to mechanical stimuli, piezoelectric materials generate electricity, suggesting that they could be used in place of hair cells to create an artificial cochlear epithelium. Here, we report that a piezoelectric membrane generated electrical potentials in response to sound stimuli that were able to induce auditory brainstem responses in deafened guinea pigs, indicating its capacity to mimic basilar membrane function. In addition, sound stimuli were transmitted through the external auditory canal to a piezoelectric membrane implanted in the cochlea, inducing it to vibrate. The application of sound to the middle ear ossicle induced voltage output from the implanted piezoelectric membrane. These findings establish the fundamental principles for the development of hearing devices using piezoelectric materials, although there are many problems to be overcome before practical application.
Chitosan-Coated Wires: Conferring Electrical Properties to Chitosan Fibers (2009)

There is considerable interest in creating convenient biosensing platforms that couple the capabilities of biology for selective detection with the power of electronics for signal transduction. Here, the capabilities of a polymeric fiber for facile biofunctionalization is coupled with the signal transduction capabilities of a conducting wire to generate a hybrid platform that can be viewed as either a biofunctionalized wire or a conducting fiber. Integral to this hybrid platform is the interface material chitosan that enables simple electrical signals to be employed to biofunctionalize conducting wires. Specifically, we use cathodic signals to direct chitosan to electrodeposit onto gold wires and anodic signals to conjugate proteins (e.g., for biosensing) to the chitosan-coated wire. In addition, the chitosan-coating is permeable to small molecules, which allows for the electrical detection of electrochemically active compounds that are either present in the external environment or generated by a biofunctionalized chitosan coating. The capabilities for biofunctionalization and transduction are demonstrated for the detection of glucose by chitosan-coated wires functionalized with the enzyme glucose oxidase. Chitosan-coated wires (or alternatively conducting chitosan fibers) are a simple platform that may permit multiplexed biosensing outside the laboratory.
Improved corrosion resistance of cation substituted YBa2Cu3O7−δ (1995)

A cosubstitution of Ca2+ for Y3+and La3+ for Ba2+ in YBa2Cu3O7−δ is found to improve the corrosion resistance of this high- Tc superconductor. The reactivity characteristics of bulk and thin film samples of Y1−zCazBa2−yLayCu3O7−δ indicate that the corrosion resistance in water environments increases with increasing degree of cation substitution up to z=y=0.4. The composition of Y0.6Ca0.4Ba1.6La0.4Cu3O6.96 with a Tc of 80 K is found to be at least 100 times more stable than YBa2Cu3O6.94. Possible contributing factors that could be responsible for the marked improvement in the corrosion resistance of this high-Tc phase are discussed.
An End-to-End Signal Strength Model for Underwater Optical Communications (2013)

In this paper, we present a generic model of signal strength in underwater optical communications. The model includes light sources, detectors, amplifier and detector circuitry, optics, as well as a simple extinction model of the water channel. The end-to-end model provides insights into optimization approaches for underwater optical modems and enables relative pose estimation between underwater optical transmitters and receivers. We instantiate our model to the AquaOptical model by determining its parameters and verifying the model prediction in a suite of pool experiments.
Learning Early Exit Strategies for Additive Ranking Ensembles (2021)

Modern search engine ranking pipelines are commonly based on large machine-learned ensembles of regression trees. We propose LEAR, a novel - learned - technique aimed to reduce the average number of trees traversed by documents to accumulate the scores, thus reducing the overall query response time. LEAR exploits a classifier that predicts whether a document can early exit the ensemble because it is unlikely to be ranked among the final top-k results. The early exit decision occurs at a sentinel point, i.e., after having evaluated a limited number of trees, and the partial scores are exploited to filter out non-promising documents. We evaluate LEAR by deploying it in a production-like setting, adopting a state-of-the-art algorithm for ensembles traversal. We provide a comprehensive experimental evaluation on two public datasets. The experiments show that LEAR has a significant impact on the efficiency of the query processing without hindering its ranking quality. In detail, on a first dataset, LEAR is able to achieve a speedup of 3x without any loss in [email protected], while on a second dataset the speedup is larger than 5x with a negligible [email protected] loss (< 0.05%).
Simulation of the stepped surface of a high-resolution X-ray diffractor (2000)

Three possible schemes of a high-resolution stepped X-ray diffractor have been analyzed, including those based on the steps of equal angular widths, the steps of equal heights (i.e., distances from the step edge to the beginning of the next step), and the symmetric steps (where a distance from the step edge to the focusing circumference is equal to the distance from the focusing circumference to the edge of the next step). It is shown that the first and the third schemes provide most stable characteristics.
A new method for body posture detection using a kinematic sensor (1999)

The objective of this study is to present a new method of physical activity monitoring, able to detect body postures (sitting, standing and lying) from only one kinematic sensor attached on the chest. Wavelet analysis in conjunction with a simple kinematics model is used to recognize different posture transitions during daily physical activity. The postures observed with this technique matched those obtained with a reference optical motion system. Accurate results were also obtained during real-life testing outside of the laboratory. This new method shows promises for efficient body posture classification
Local amplitude and phase retrieval method for digital holography applied to microscopy (2003)

We present a numerical two-step reconstruction procedure for digital off-axis Fresnel holograms. First, we retrieve the amplitude and phase of the object wave in the CCD plane. For each point we solve a weighted linear set of equations in the least-squares sense. The algorithm has O(N) complexity and gives great flexibility. Second, we numerically propagate the obtained wave to achieve proper focus. We apply the method to microscopy and demonstrate its suitability for the real time imaging of biological samples.
Sex Pheromone Production and Calling inHelicoverpa zea(Lepidoptera: Noctuidae): Effect of Temperature and Light (1991)

Sex pheromone production in females of the corn earworm, Helicoverpa zea (Boddie), starts with the onset of scotophase and when the titer of the pheromone reaches ≍30 ng (usually within 30 min), females start calling. Brief exposure of scotophase females to light increased calling significantly, with a corresponding decrease in pheromone titer. Females in photophase can produce pheromone if injected with the pheromone biosynthesis activating neuropeptide (PBAN), but the titer declines rapidly after 1 h. The titer continues to increase in scotophase females for 4 h. The observed lack of pheromone production at low temperatures (14°C) is probably attributable to inhibition of PBAN release and to lower pheromone biosynthetic activity.
SiGe based Ka-band reflection type phase shifter for integrated phased array transceivers (2016)

Phase shifters are key components in phased array systems. A low loss and low loss variations SiGe differential phase shifter for the Ka-band is described. This bidirectional differential reflection type phase shifter (RTPS) design employs a novel diagonal configuration for the coupler and it is controlled by a single voltage node. The measured results show state of the art insertion loss of 5±1 dB, phase tuning range larger than 180 degrees, for a frequency range of 26.5 GHz to 32.8 GHz (21%). At 30 GHz, the phase shifter exhibits insertion loss of 4.8 dB, loss variation of ±0.4 dB, and more than 206 degrees of phase shift range. The RTPS was fabricated in a standard BiCMOS SiGe process and occupies 0.64 mm2 die area.
Long-term and instantaneous burnout in GaAs power FET's: Mechanisms and solutions (1981)

Catastrophic source-drain burnout is an important failure mode in GaAs power FET's. In this paper we show that short-term (instantaneous) and long-term (aging) failures have different physical origins provided the underlying drain ohmic-contact weakness has been suppressed by use of a recessed n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> drain ledge geometry. With this drain configuration, instantaneous burnout is due to thermal runaway of the buffer/substrate when local temperatures reach the 500-550°C range. For our typical devices With 30-50-µm-thick substrates, the associated de burnout power is 4-5 W/mm of gate periphery. Long-term aging failure, on the other hand, results from chemical changes at the GaAs surface between gate and drain. These changes induce localized areas of avalanche white-light emission, particularly along the n <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> ledge, which serve as burnout precursors. A series of aging, surface etching, and passivation experiments has revealed that oxygen probably plays a major role in the aging process, perhaps through its known effect on free arsenic formation. Moreover, it is found that minimization of the oxygen content at the top surface by using si <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> N <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> :H passivation rather than SiO <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> not only prevents white-light emission but increases the median life at 310°C channel temperature from 2.5 to more than 500 h.
Artifact analysis of approximate helical cone‐beam CT reconstruction algorithms (2001)

In this paper, four approximate cone-beam CT reconstruction algorithms are compared: Advanced single slice rebinning (ASSR) as a representative of algorithms employing a two dimensional approximation, PI, PI-SLANT, and 3-PI which all use a proper three dimensional back-projection. A detailed analysis of the image artifacts produced by these techniques shows that aliasing in the z-direction is the predominant source of artifacts for a 16-row scanner with 1.25 mm nominal slice thickness. For a detector with isotropic resolution of 0.5 mm, we found that ASSR and PI produce different kinds of artifacts which are almost at the same level, while PI-SLANT produces none of these artifacts. It is shown that the use of redundant data in the 3-PI method suppresses aliasing artifacts efficiently for both scanners.
An erbium-doped multimode optical fiber amplifier (1991)

The authors describe the first experimental study of an erbium-doped multimode fiber amplifier. The focus has been to characterize an intermediate core erbium-doped optical fiber, a fiber that is capable of propagating many guided modes at both the signal and pump wavelengths, and to determine the feasibility of using such an active fiber as a multimode fiber amplifier, by measuring its gain, noise, and pump power requirements. For a 2-m length of a 13- mu m-core erbium-doped fiber, the authors measured gain as high as 16 dB at a signal wavelength of 1543 nm, with approximately 100 mW pump power (980 nm). For these same test conditions, the smallest excess noise factor beta was 42.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Improved Viterbi Decoder Metrics for Two-Stage Detectors in DS-CDMA (2004)

Modified branch metrics are proposed for single-user Viterbi decoders in two-stage detectors for convolutionally-encoded code-division multiple-access (CDMA) systems with random spreading sequences. The modifications are based on modeling the residual multiple-access interference (RMAI) after subtractive interference cancellation as conditionally Gaussian with time-dependent variance, where the conditioning is on the time-varying user crosscorrelations. A novel estimate of the variance of the total RMAI is presented, and used in the proposed branch metrics. Significant performance gains are demonstrated over the Euclidean branch metric of the standard Viterbi decoder.
Holographic Television at the MIT Media Lab (2012)

Several recent advances point the way toward real‐time holographic television for telepresence, entertainment, and teleoperation. This article introduces the concepts and requirements for such systems, then presents the MIT Media Lab's work to make them practical and inexpensive.
A Cooperative Backup System (2003)

We present a novel peer-to-peer backup technique that allows computers connected to the Internet to back up their data cooperatively: Each computer has a set of partner computers, which collectively hold its backup data. In return, it holds a part of each partnerâs backup data. By adding redundancy and distributing the backup data across many partners, a highly-reliable backup can be obtained in spite of the low reliability of the average Internet machine. Because our scheme requires cooperation, it is potentially vulnerable to several novel attacks involving free riding (e.g., holding a partnerâs data is costly, which tempts cheating) or disruption. We defend against these attacks using a number of new methods, including the use of periodic random challenges to ensure partners continue to hold data and the use of disk-space wasting to make cheating unprofitable. Results from an initial prototype show that our technique is feasible and very inexpensive: it appears to be one to two orders of magnitude cheaper than existing Internet backup services.
Complement C5b-9-stimulated platelet secretion is associated with a Ca2+-initiated activation of cellular protein kinases. (1987)

Membrane assembly of the C5b-9 proteins on gel-filtered human platelets has been shown to initiate the nonlytic release of alpha-granule contents and expression of membrane prothrombinase sites, suggesting cellular activation by these ostensibly cytolytic plasma proteins (Wiedmer, T., Esmon, C. T., and Sims, P. J. (1986) J. Biol. Chem. 261, 14587-14592). We now examine the mechanism of the C5b-9-induced release reaction. The release of alpha-granule contents upon C5b-9 assembly is accompanied by expression of alpha-granule membrane glycoprotein 140 on the platelet surface, confirming that the complement-mediated release reaction occurs by secretory fusion of the alpha-granule with the plasma membrane. C5b-9 binding initiates the phosphorylation of both 40- and 20-kDa platelet proteins, indicative of activation of protein kinase C and myosin light chain kinase, respectively. Activation of cellular protein kinases under these conditions was not accompanied by the formation of inositol phosphates and was found to strictly depend upon extracellular Ca2+, suggesting that the platelet's secretory response to the C5b-9 proteins is triggered directly by the influx of Ca2+ across the plasma membrane. measurement of intracellular Ca2+ confirmed that elevation of this ion in the cytosol was strictly dependent upon increased plasma membrane permeability due to C5b-9 assembly and was not accompanied by mobilization of this ion from internal storage pools. The C5b-9-mediated secretory response was blocked by sphingosine, a potent inhibitor of protein kinase C, but was unaffected by the cyclooxygenase inhibitor indomethacin, suggesting that feedback (receptor-linked) by thromboxane is not required for platelet activation after C5b-9 insertion.