gebhart/patrepeval huggingface dataset:
Atom transfer graft copolymerization of 2‐ethyl hexylacrylate from labile chlorines of poly(vinyl chloride) in an aqueous suspension (2006)

Abstract Copper‐mediated atom transfer radical polymerization (ATRP) is presented as a versatile tool for the graft copolymerization of 2‐ethyl hexylacrylate with poly(vinyl chloride) (PVC) in an aqueous suspension. The appreciable solubility of PVC in 2‐ethyl hexylacrylate (30%) at temperatures around 130 °C makes grafting of the monomer possible from labile chlorines of PVC in aqueous suspensions without the use of additional solvent. The first‐order kinetics (rate constant k = 4.2 × 10 −6 s −1 ) of the mass percentage increase reveals a typical ATRP fashion of the graft copolymerization at low conversions. The use of a completely organosoluble copper(I) complex of hexylated triethylene tetramine, in combination with α‐methylcellulose as a stabilizer, makes the graft copolymerization possible in a dispersed organic phase. Nearly spherical, green particles can be obtained with moderate stirring rates (1000 rpm) in high graft yields. Although the kinetics of the reaction deviates from the first order at high conversions, reasonable graft yields (146%) can be attained within a reaction period of 24 h. In this study, the reaction conditions of the grafting have been studied, and graft products have been confirmed by common techniques such as 1 H NMR, gel permeation chromatography, and differential scanning calorimetry. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1900–1907, 2006
Quantum dynamics of the molecular magnet driven by external magnetic fields (2004)

The quantum dynamics of the mesoscopic molecular magnet under the influence of external magnetic fields is studied. We show that when the frequency and the reduced amplitude of the longitudinal magnetic field are related in a specific manner, the magnetization tunneling will be dynamically suppressed during time evolution. The effects of external noise and anisotropy on this dynamic spin localization are studied. In particular, we show that the anisotropy interaction may enhance the spin localization phenomenon.
Detection of Activity Centers in Cellular Pathways Using Transcript Profiling (2004)

We present a new computational method for identifying regulated pathway components in transcript profiling (TP) experiments by evaluating transcriptional activity in the context of known biological pathways. We construct a graph representing thousands of protein functional relationships by integrating knowledge from public databases and review articles. We use the notion of distance in a graph to define pathway neighborhoods. The pathways perturbed in an experiment are then identified as the subgraph induced by the genes, referred to as activity centers, having significant density of transcriptional activity in their functional neighborhoods. We illustrate the predictive power of this approach by performing and analyzing an experiment of TP53 overexpression in NCI-H125 cells. The detected activity centers are in agreement with the known TP53 activation effects and our independent experimental results. We also apply the method to a serum starvation experiment using HEY cells and investigate the predicted activity of the transcription factor MYC. Finally, we discuss interesting properties of the activity center approach and its possible applications beyond the comparison of two experiments.
Some effects of mill practice on the stress strain behavior of ACSR (1999)

Operating temperatures of overhead lines have risen. Tests have indicated that conventional sag tension calculations may underestimate sags that occur at the higher temperatures in ACSR (aluminum conductor steel reinforced) spans. Search for the source of the disparities has identified two effects associated with the manner in which conductors are manufactured. One effect involves residual stresses, resulting from stranding practice, in the finished conductor. The other is caused by the ability of the aluminum part of ACSR to bear axial compression. Analysis of these effects appears to explain the disparity in at least one of the test programs that revealed it.
One-dimensional, nonlinear determinism characterizes heart rate pattern during paced respiration (1998)

This study focuses on the dynamic pattern of heart rate variability in the frequency range of respiration, the so-called respiratory sinus arrhythmia. Forty experimental time series of heart rate data from four healthy adult volunteers undergoing a paced respiration protocol were used as an empirical basis. For pacing-cycle lengths >8 s, the heartbeat intervals are shown to obey a rule that can be expressed by a one-dimensional circle map (next-angle map). Circle maps are introduced as a new type of model for time series analyses to characterize the nonlinear dynamic pattern underlying the respiratory sinus arrhythmia during voluntary paced respiration. Although these maps are not chaotic, the dynamic pattern shows typical imprints of nonlinearity. By starting from a piecewise linear model, which describes the different circle maps obtained from the empirical time series for various pacing frequencies, time invariant measures can be introduced that characterize the dynamic pattern of heart rate variability during voluntary slow-paced respiration.
<scp>PPAR‐γ</scp> – a possible drug target for complicated pregnancies (2012)

Peroxisome proliferator activated receptors (PPARs) are ligand-activated transcription factors expressed in trophoblasts, which regulate both cell differentiation and proliferation. In recent years, evidence has linked PPARs to playing an integral role in pregnancy; specifically, PPAR-β and PPAR-γ have been shown to play an integral role in placentation, with PPAR-γ additionally serving to regulate trophoblast differentiation. Recent evidence has shown that PPAR-γ expression is altered in many complications of pregnancy such as intrauterine growth restriction (IUGR), preterm birth, pre-clampsia and gestational diabetes. Thus, at present, accumulating evidence from the literature suggests both a pivotal role for PPAR-γ in the progression of a healthy pregnancy and the possibility that PPAR-γ may act as a therapeutic target in complicated pregnancies. This review aims to provide a succinct and comprehensive assessment of the role of PPAR-γ in normal pregnancy and pregnancy complications, and finally its potential as a therapeutic target in the treatment and/or prevention of adverse pregnancy outcomes.
Chemobiosynthesis of Novel 6-Deoxyerythronolide B Analogues by Mutation of the Loading Module of 6-Deoxyerythronolide B Synthase 1 (2005)

Chemobiosynthesis (J. R. Jacobsen, C. R. Hutchinson, D. E. Cane, and C. Khosla, Science 277:367-369, 1997) is an important route for the production of polyketide analogues and has been used extensively for the production of analogues of 6-deoxyerythronolide B (6-dEB). Here we describe a new route for chemobiosynthesis using a version of 6-deoxyerythronolide B synthase (DEBS) that lacks the loading module. When the engineered DEBS was expressed in both Escherichia coli and Streptomyces coelicolor and fed a variety of acyl-thioesters, several novel 15-R-6-dEB analogues were produced. The simpler "monoketide" acyl-thioester substrates required for this route of 15-R-6-dEB chemobiosynthesis allow greater flexibility and provide a cost-effective alternative to diketide-thioester feeding to DEBS KS1(o) for the production of 15-R-6-dEB analogues. Moreover, the facile synthesis of the monoketide acyl-thioesters allowed investigation of alternative thioester carriers. Several alternatives to N-acetyl cysteamine were found to work efficiently, and one of these, methyl thioglycolate, was verified as a productive thioester carrier for mono- and diketide feeding in both E. coli and S. coelicolor.
Fast solution techniques for a class of optimal trajectory planning problems with applications to automated spray coating (1997)

Optimal trajectory planning problems are often formulated as constrained variational problems. In general, solutions to variational problems are determined by appropriately discretizing the underlying objective functional and solving the resulting nonlinear differential equation(s) and/or nonlinear programming problem(s) numerically. These general solution techniques often require a significant amount of time to be computed, and therefore are of limited value when optimal trajectories need to be frequently computed and/or recomputed. In this paper, a realistic class of optimal trajectory planning problems is defined for which the existence of fast numerical solution techniques are demonstrated. To illustrate the practicality of this class of trajectory planning problems and the proposed solution techniques, three optimal trajectory planning problems for spray coating applications are formulated and solved. Based on the proposed discretization technique, it is shown that these problems can be reduced to either a linear program or a quadratic program, which are readily solved.
Biology of Arizona termites with emphasis on swarming (1948)

(Uploaded by Plazi from the Biodiversity Heritage Library) No abstract provided.
Performance Optimization Using Multipath Routing in Mobile Ad Hoc and Wireless Sensor Networks (2006)

Multipath routing has been a promising technique in MANETs and WSNs. It has been shown through both theoretical analysis and simulation results that multipath routing provides many performance benefits, including improved fault tolerance, security, and reliability, improved routing efficiency and reduced routing overhead, more balanced traffic load and energy consumption, reduced end-to-end latency, and aggregated network bandwidth, etc. Significant research efforts have been made and are continuously being made in developing multipath routing protocols and multipath packet forwarding techniques in order to achieve the above-mentioned performance gains effectively and efficiently. Nevertheless, many issues that are directly related to the application of multipath routing remain untouched, such as the integration of the multipath routing into the current single-path routing paradigm, the synchronization of the packets among the multiple paths, and the interfaces of multipath routing protocols to other layers of protocol in the network protocol stack, etc. Due to space limitations, we are only able to introduce the basic concept of multipath routing, highlight the fundamental techniques used to find the multiple paths, and outline the essential idea of what and why it can help in performance. For detailed algorithms/protocols as well as performance evaluations, interested readers are referred to respective publications.
Robust color image segmentation based on mean shift and marker-controlled watershed algorithm (2004)

A new method for color image segmentation is presented. It combines mean shift with watershed algorithm to get robust results. First, mean shift procedure is used to find the highest density regions which correspond to clusters centered on the modes (local maxima) of the underlying probability distribution in the feature space. The principal component of each significant color is extracted by mode. Second, homogeneous regions corresponding to the modes are as markers to label an image, then marker-controlled watershed transformation is applied to the image segmentation. The segmentation of blood cells is discussed. The input parameters are a few initial color markers that represent significant colors. By combining both methods, the oversegmentation is able to be prevented, touching and overlapping nucleated cells can be separated, and running time is reduced too. The proposed algorithm is very robust to different color space, varied preparation and illumination for blood cell images. It is suitable to segment color microscope images.
PZT thin film actuated elastic fin micromotor (1998)

A piezoelectric elastic fin micromotor based on a PbZr(0.53 )Ti(0.47)O(3) thin film driving a micromachined silicon membrane was fabricated and studied. The stator was characterized by interferometry, and a laser set-up was used to measure the angular velocity and acceleration of the motor. The torque, the output power, and the efficiency of the device were extracted from these measurements. Values up to 1020 rpm and 0.94 microNm were observed for the velocity and the torque, respectively, which would be sufficient for a wristwatch application. The present version exhibited an efficiency of 0.17%, which could theoretically be increased to 4.8%
Catalytic Cleavage of Vasopressin by Human Bence Jones Proteins at the Arginylglycinamide Bond (1996)

Bence Jones proteins were capable of hydrolyzing a peptide bond between arginine-8 and the C-terminal glycinamide of vasopressin. This peptidolytic activity obeyed typical Michaelis-Menten kinetics and exhibited optimal activity at pH 8.2 and Km of 0.6-1.9 mM. The catalytic efficiency, kcat/Km, was calculated to be 0.8 to 5.8 min(-1)M(-1). The Bence Jones proteins displayed turnover, an essential feature of enzymes. These results suggest that slow proteolysis, especially in the renal tubules which are 'saturated' with Bence Jones proteins, may have a pathophysiological significance for various nephropathies often associated with multiple myeloma with Bence Jones proteinuria.
Measurement of Si Epitaxial Thickness Using a Michelson Interferometer (1973)

A system has been designed to measure the thickness of silicon epitaxial material using a scanning Michelson interferometer rather than a conventional dispersive IR spectrometer. The sampling capacity of this system with a 5–6 sec sampling time exceeds that of several dispersive instruments. The long‐term precision on a single machine (3σ) is , where is the film thickness. Computer processing of the reflection interferogram from an epitaxial wafer provides film thickness data by a Fourier transform method. This method is shown to be mathematically equivalent to the method used for dispersion spectrometers as given by ASTM procedure F95‐68T. The two measurements are in agreement within the published interlaboratory precision of the ASTM method: for P‐type material and for N‐type. The lack of moving mechanical parts in the interferometer system contributes to making this type of instrument very reliable. Down time due to system failure has been minimal, and two systems have been in operation a total of over 4 machine years.
Experimental Investigation of the Statistics of Sound-Power Radiation in a Reverberant Room (1972)

The measurement of sound-power injection into a reverberant room is subject to statistical uncertainties owing to the large fluctuations of SPL with variation of source and/or receiver position. Low-frequency pure-tone sources generally require many microphone and source positions if radiated sound power is to be accurately measured. An experimental investigation of low-frequency pure-tone sound radiation into a reverberant room has been conducted using both an 8-in. loudspeaker and a 30-in. loudspeaker at five source positions. The resulting standard deviation of sound-power output of the smaller speaker with source position is in excellent agreement with existing theory if the data is adjusted to account for the finite number of independent microphone readings. Standard deviation of the sound-power output of the larger speaker with source position is significantly lower than the theory at frequencies below 500 Hz. [NASA is acknowledged for partial sponsorship of this work.]
High-average-power (>20-W) Nd:YVO-4 lasers mode locked by strain-compensated saturable Bragg reflectors (2000)

Strain-compensated double InGaAs quantum-well saturable Bragg reflectors (SBR’s) with high damage thresholds have been developed for use as mode-locking elements in high-average-power neodymium lasers. Nd:YVO4 lasers have been developed with these new SBR’s, which produce transform-limited pulses of 21-ps duration at 90 MHz and an average power of 20 W in a diffraction-limited output beam. The peak pulse power at an output power of 20 W was 10.6 kW. A comparison of the operating parameters of strained single and strain-compensated double-well SBR’s indicates that the damage threshold increased by a factor of at least 2–3. Long cavity laser variants were nvestigated to assess the limitations of further power scaling. At a repetition frequency of 36-MHz stable mode-locked pulses with peak pulse powers of 24.4 kW and pulse energies of 0.6 mJ could be generated.
Premalignant alterations in the lipid composition and fluidity of colonic brush border membranes of rats administered 1,2 dimethylhydrazine. (1986)

Dimethylhydrazine (DMH) is a potent procarcinogen with se- lectivity for the colon. To determine whether alterations in the lipid composition and fluidity of rat colonic brush border mem- branes existed before the development of DMH-induced colon cancer, rats were injected s.c. with this agent (20 mg/kg body weight per wk) or diluent for 5, 10, and 15 wk. Animals were killed at these time periods and brush border membranes were prepared from proximal and distal colonocytes of each group. The "static" and "dynamic" components of fluidity of each membrane were then assessed, by steady-state fluorescence po- larization techniques using limiting hindered fluorescence an- isotropy and order parameter values of the fluorophore 1,6 di- phenyl-1,3,5-hexatriene (DPH) and fluorescence anisotropy values of DL-249-anthroyl) stearic acid and DL-12(9-anthroyl) stearic acid, respectively. Membrane lipids were extracted and analyzed by thin-layer chromatography and gas-liquid chroma- tography. Phospholipid methylation activity in these membranes was also measured using S-adenosyl-L-methionine as the methyl donor.
Quality and quantity of bone following alveolar distraction osteogenesis in the human mandible (2006)

Results from this study showed that (a) distraction osteogenesis is a reliable technique for the correction of vertically deficient edentulous ridges, (b) the regenerated bone withstood the functional demands of implant loading, (c) survival and success rates of implants placed in the distracted areas were consistent with those of implants placed in native bone, and (d) there is sufficient bone volume and maturity in the distracted region for primary stability of the implant.
Joint ml estimation of frame timing and carrier frequency offset for OFDM systems employing time-domain repeated preamble (2010)

When a preamble signal is repeated multiple times in OFDM systems, we derive joint maximum likelihood (ML) estimation of the frame timing (FT) and carrier frequency offset (CFO). Unlike conventional estimators which use correlation of adjacent repetition patterns only or some specific sets of patterns, the joint ML estimation exploits correlation of any pair of repetition patterns, providing optimized performance. To reduce the implementation complexity involved in the joint ML estimation, we also propose a near-ML estimation method that separates estimation of the FT and the CFO. The performance of the proposed methods is verified by computer simulation.
Alkyne Phosphonites for Sequential Azide–Azide Couplings (2013)

When Staudinger meets Huisgen! A combination of the copper-catalyzed variant of the Huisgen azide–alkyne cycloaddition (CuAAC) and the Staudinger reaction, the two most successful chemoselective reactions for the transformation of azides, leads to a chemical method that allows the sequential coupling of two different azido building blocks in high yields. This modular procedure enables a final metal-free conjugation of functional building blocks to azides. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to 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.
A MHz Repetition Rate OPO System for Ultra-high Frame Rate PLIF Imaging (2005)

We demonstrate the ability to generate ultra-high frequency sequences of broadly wavelength tunable, high intensity laser pulses using a custom built Optical Parametric Oscillator (OPO) pumped by the third harmonic output of a “burst” mode Nd:YAG laser. Burst sequences consisting of 6 – 10 pulses separated in time by between 6 and 10 microseconds are obtained, with average conversion efficiency from 355 nm pump to ~651 nm signal of approximately 12%, corresponding to individual 651 nm single pulse energy of ~ 1.7 mJ. In a manner similar to that employed previously for narrowing the output of a Titanium:Sapphire laser, an external cavity diode laser at 780 nm is used to injection seed the OPO cavity, resulting in substantial narrowing, from ~25 to ~ 2.5 cm (or less), for both the signal and idler waves. Similar, albeit more preliminary, results were obtained for 532 nm pumping.
Rapid DNA Amplification Using a Battery-Powered Thin-Film Resistive Thermocycler (2009)

A prototype handheld, compact, rapid thermocycler was developed for multiplex analysis of nucleic acids in an inexpensive, portable configuration. Instead of the commonly used Peltier heating/cooling element, electric thin-film resistive heater and a miniature fan enable rapid heating and cooling of glass capillaries leading to a simple, low-cost Thin-Film Resistive Thermocycler (TFRT). Computer-based pulse width modulation control yields heating rates of 6-7 K/s and cooling rates of 5 K/s. The four capillaries are closely coupled to the heater, resulting in low power consumption. The energy required by a nominal PCR cycle (20 s at each temperature) was found to be 57+/-2 J yielding an average power of approximately 1.0 W (not including the computer and the control system). Thus the device can be powered by a standard 9 V alkaline battery (or other 9 V power supply). The prototype TFRT was demonstrated (in a benchtop configuration) for detection of three important food pathogens (E. coli ETEC, Shigella dysenteriae, and Salmonella enterica). PCR amplicons were analyzed by gel electrophoresis. The 35 cycle PCR protocol using a single channel was completed in less then 18 min. Simple and efficient heating/cooling, low cost, rapid amplification, and low power consumption make the device suitable for portable DNA amplification applications including clinical point of care diagnostics and field use.