gebhart/patrepeval huggingface dataset:
Antiviral nucleoside diphosphate diglycerides: improved synthesis and facilitated purification. (1992)

Cytidine diphosphate diglyceride and its analogs have previously been synthesized by condensing phosphatidic acid with the monophosphomorpholidates of the various nucleosides. Yields have been low and purification of the product has been difficult. We report here an improved method for the synthesis of nucleoside diphosphate diglycerides with potential antiviral activity. Phosphatidic acid was activated with morpholine in the presence of dicyclohexylcarbodiimide to phosphatidic acid morpholidate. This compound was condensed with the 5'-monophosphate of the anti-HIV agents 3'-azido-3'-deoxythymidine, 3'-deoxythymidine or 2',3'-dideoxycytidine, and the monophosphate of the anti-HSV agent acyclovir. The resulting nucleoside diphosphate diglycerides are potential candidates for improved antiviral action when compared to the parent nucleoside analogs. Compared to the older method for the preparation of cytidine diphosphate diglyceride and analogs thereof, the new method has several advantages: reaction times are reduced from several days to several hours and the yield of the reactions is generally increased from 20-40% to between 50 and 80%. In addition, the purification of the compounds is greatly facilitated due to the small amount of phosphatidic acid remaining in the reaction mixture.
Frequency Dependence of Gold Nanoparticle Superassembly by Dielectrophoresis (2007)

Dielectrophoresis is an effective method for capturing nanoparticles and assembling them into nanostructures. The frequency of the dielectrophoretic alternating current (ac) electric field greatly influences the morphology of resultant nanoparticle assemblies. In this study, frequency regimes associated with specific gold nanoparticle assembly morphologies were identified. Gold nanoparticles suspended in water were captured by microelectrodes at different electric field frequencies onto thin silicon nitride membranes. The resultant assemblies were examined by transmission electron microscopy. For this system, the major frequency-dependent influence on morphology appears to arise not from the Clausius-Mossotti factor of the dielectrophoretic force itself, but instead from ac electroosmotic fluid flow and the influence of the electrical double layer at the electrode-solution interface. Frequency regimes of technological interest include those forming one-dimensional nanoparticle chains, microwires, combinations of microwires and nanoparticle chains suitable for nanogap electrode formation, and dense three-dimensional assemblies with very high surface area.
Enhancement of echo-signal correlation in elastography using temporal stretching (1997)

Echo-signal decorrelation due to tissue compression is a significant source of error in tissue displacement estimates obtained using crosscorrelation. Tissue displacement estimates are used to compute strain values for imaging the elasticity of biological soft tissues. The correlation coefficient between the pre- and post-compression echo rf signals reduces rapidly with signal decorrelation due to increased compression. Miniscule reductions in the value of the correlation coefficient can have a significant impact on the performance of the strain estimator as illustrated by the strain filter. Reducing the rate of signal decorrelation using temporal stretching (which improves the value of the correlation coefficient), significantly improves the performance of the strain filter. The reduction in the rate of signal decorrelation with the subsequent increase in the correlation coefficient using temporal stretching is discussed in this paper. Theoretical, simulation and experimental results quantify the enhancement in the value of the correlation coefficient attained with temporal stretching.
Theoretical characterization of flux reversal machine in low-speed servo drives-the pole-PM configuration (2002)

This paper introduces and analyzes a flux reversal machine (FRM) configuration for low-speed (below 150 r/min) servo drives. The FRM configuration includes stator poles with three-phase concentrated coils and 2n/sub p/ alternate polarity permanent magnets per stator pole and a salient multiple-pole passive rotor. In-depth finite-element method analysis shows high torque density and less than 3% torque pulsation (through adequate rotor skewing) with sinusoidal three-phase vector control.
Quercetin: potentials in the prevention and therapy of disease (2008)

Quercetin is a most promising compound for disease prevention and therapy; however, many of the effects still need confirmation by human intervention trials.
Management of Hypertension in Pregnancy (1999)

Hypertension in pregnancy is generally defined as either an absolute BP > 140/90 mm Hg or a rise in systolic BP > or = 25 mm Hg and/or diastolic BP > or = 15 mm Hg from pre-conception or 1st trimester BP. Hypertension in pregnancy is classified as: a) Chronic--essential or secondary hypertension, b) De novo--pre-eclampsia or gestational hypertension, and c) Pre-eclampsia superimposed on chronic hypertension. Pre-eclampsia is a multisystem disorder in which hypertension is but one sign. The major maternal abnormalities occur in kidneys, liver, brain and coagulation systems. Impaired uteroplacental blood flow causes fetal growth retardation or intrauterine death. There is general agreement that BP > or = 170/110 mm Hg should be lowered rapidly to protect the mother against risk of stroke or eclampsia. There is dispute concerning the level at which lesser degrees of hypertension should be treated, and lowering BP is treating only one aspect of pre-eclampsia. Delivery remains the definitive management.
Conditioning reservoir models to dynamic data - A forward modeling perspective (2000)

Abstract In order to predict accurately future production performance, a reservoir model should reflect the actual patterns of permeability connectivity (flow paths and barriers). Information about such patterns of connectivity is carried by flow response data recorded at wells. However, the flow response data are influenced by many factors other than permeability connectivity such as boundary conditions and fluid property variations. This paper presents a neural network-based procedure for filtering the information related to the permeability field in flow response data. The flow response data is modeled as specific multiple point averages of permeability values in the neighborhood of the well. Such multiple point averages allow accounting for the spatial connectivity of the permeability field. The superiority of such multiple point averages over single point permeability averages for representing flow response data is demonstrated over several reservoir examples. The ultimate quest is to integrate the permeability connectivity information contained in the flow response data into the numerical reservoir models. This amounts to ascertain that the permeability numerical models identify the previous multiple point averages. A Markov chain Monte Carlo simulation algorithm is implemented to perform this identification. Alternative equiprobable permeability fields are generated which, in addition to reproducing the production data, conform to a prior model for the spatial variability of the permeability field. The results demonstrate that flow simulation on the simulated permeability fields do indeed match historic well test data accurately. More importantly, future reservoir performance predictions are rendered more accurate.
Phenylenediamine-based bivalent glycocyclophanes: synthesis and analysis of the influence of scaffold rigidity and ligand spacing on lectin binding in cell systems with different glycomic profiles (2009)

The conjugation of carbohydrates to synthetic scaffolds has the goal of preparing potent inhibitors of lectin binding. We herein report the synthesis of a panel of bivalent compounds (cyclophane and terephthalamide-derivatives) then used to establish the influence of scaffold flexibility on respective inhibitory potency in a medically relevant test system. Synthetic routes to two phenylenediamine-based glycocyclophanes involving Ugi reactions of glucuronic acid derivatives and subsequent ring closing metathesis are described, as are improvements for producing terephthalamide-based carbohydrate carriers. Assays were performed with human tumour cells measuring quantitatively the influence of the test compounds on fluorescent surface staining by labelled lectins. Biological evaluation using two different lines of cancer cells as well as cells with known alterations in the glycomic profile (cells treated with an inhibitor of glycan processing and a glycosylation mutant) reduced the risk of generating premature generalizations regarding inhibitor potency. Bioactivity relative to free mannose was invariably determined for the synthetic compounds. A clear trend for enhanced inhibitory properties for macrocyclic compounds compared to non-macrocyclic derivatives was discerned for one type of glycocyclophane. Herein we also document the impact of altering the spacing between the mannose residues, altering cell surface ligand density and cell-type reactivity. The applied strategy for the cell assays is proposed to be of general importance in the quest to identify medically relevant lectin inhibitors.
Characteristics of high-density recording using a single-layer perpendicular medium and a merged MR head (1996)

The combination of a merged MR head and a single-layer perpendicular medium is a promising technology for high-density recording. This paper describes a system that provides high-linear-density recording (over 150 kFCI) without requiring a contact recording method. Both-the large magnetic anisotropy and the large crystalline orientation of a Cr-rich Co/sub 72/Cr/sub 28/ medium hold out the promise of higher linear density. The large output signal also shows the possibility of increasing the track density. The baseline shift for narrow track widths is an issue that must be solved by equalization before this system can be used to realize future hard disk drive products.
Treatment of restless legs syndrome with pregabalin (2010)

This study provides Class II evidence that pregabalin is effective for the treatment of restless legs syndrome and improves sleep architecture and periodic limb movements in placebo-unresponsive patients.
Oxygen as attractant and repellent in bacterial chemotaxis (1987)

Studies of bacterial chemotaxis to oxygen (aerotaxis) over a broad range of oxygen concentrations showed that at high concentrations, oxygen was a repellent of Salmonella typhimurium, Escherichia coli, and some bacilli, whereas it is known that at lower concentrations (less than or equal to 0.25 mM dissolved oxygen), oxygen is an attractant. In a temporal assay of aerotaxis, S. typhimurium in medium equilibrated with air (0.25 mM dissolved oxygen) and then exposed to pure oxygen (1.2 mM) tumbled continuously for approximately 20 s. The oxygen concentration that elicited a half-maximal negative (repellent) response was 1.0 mM for both S. typhimurium and E. coli. The receptor for the negative chemoresponse to high concentrations of oxygen is apparently different from the receptor for the positive chemoresponse to low concentrations of oxygen, since the oxygen concentration that elicits a half-maximal positive (attractant) response in S. typhimurium and E. coli is reported to be 0.7 microM. Adaptation to high concentrations of oxygen, like adaptation to low concentrations of oxygen, was independent of methylation of a transducer protein. Only the response to low oxygen concentrations, however, was altered by interaction with the amidated Tsr transducer in cheB mutants.
Abundant transcription of a cellular gene in T cells infected with human T-cell leukemia-lymphoma virus. (1983)

Human T-cell leukemia-lymphoma virus (HTLV) is a type C retrovirus associated with a subtype of mature T-cell malignancy in humans. HTLV also infects normal human cord blood mature T lymphocytes in vitro and induces a number of phenotypic changes in these cells, including their continuous growth and partial or complete independence of T-cell growth factor (TCGF). As part of our initial study designed to analyze gene(s) specifically activated by HTLV infection, we have isolated a recombinant DNA clone by differential screening of a cDNA library made from mRNA of a human T-cell lymphoma cell line producing HTLV. This cDNA identifies a single-copy gene in all human DNAs and a single mRNA species of 2.3 kilobases expressed at several hundred copies per cell in five HTLV-positive neoplastic T-cell lines. In addition, cord blood T lymphocytes infected with HTLV, but not the uninfected counterparts, express high levels of mRNA from this gene. A survey of different human hematopoietic cell types showed that this gene is expressed at low or undetectable levels (less than 10 copies) in human T, B, myeloid, or erythroid cell lines; in moderate amounts in lymphoid precursor (immature) cell lines; and in high amounts in lectin-activated mature T-cells, comparable to those of HTLV-infected T-cell lines. The precise function of this gene has not yet been determined.
Dual Types of Spherulites in Poly(octamethylene terephthalate) Confined in Thin-Film Growth (2008)

Spherulite morphology and growth kinetics of poly(octamethylene terephthalate) (POT), cast on single-side glass or confined between two slides in thin-film forms, were characterized using polarized versus nonpolarized optical microscopy, scanning electron microscopy (SEM), and wide-angle X-ray (WAXD) analysis. POT can simultaneously display solely one type of spherulite or dual types of spherulites (double-ring-banded and ringless ones), depending on T c or T max imposed. Fractions of these two types depend on T c when quenched from a fixed T max = 160 degrees C. At lower T c's, POT exhibits higher crystallization rates leading to higher fractions of ringless spherulites; at higher T c's, POT exhibits lower crystallization rates leading to ring-banded spherulites. At intermediate to high T c's where the growth kinetics of POT could be monitored, the ring-band type dominates and the fraction of ringless spherulites is insignificantly small. Both ringless and ring-banded spherulites can be seen in regime III ( T c = 70-110 degrees C), with fractions of ringless type of spherulites decreasing with temperature. Thus, growth kinetics for POT was mainly focused on the regime of ring-banded spherulites. In regime III, the ring-band pattern is more orderly concentric with smaller inter-ring spacing (1-2 mum) for lower T c's but intermediately larger spacing (3-5 mum) for higher T c's. The orderly lamellar orientation in the ring-bands in contrast with the inter-ring valley region is discussed. In regime II (115 degrees C and above), the ring-band pattern is first distorted to highly zigzag irregularity at higher T c's and then eventually disappears at extremely high T c, with the lamellar crystals eventually turning dendritic with no rings. Apparently, the types of spherulites in polymers are more influenced by the growth rates as determined by T c and slightly less by T max, but not by the substrate surface nucleation.
High-dimensional orbital angular momentum entanglement concentration based on Laguerre–Gaussian mode selection (2013)

Twisted photons enable the definition of a Hilbert space beyond two dimensions by orbital angular momentum (OAM) eigenstates. Here we propose a feasible entanglement concentration experiment, to enhance the quality of high-dimensional entanglement shared by twisted photon pairs. Our approach is started from the full characterization of entangled spiral bandwidth, and is then based on the careful selection of the Laguerre–Gaussian (LG) modes with specific radial and azimuthal indices p and l. In particular, we demonstrate the possibility of high-dimensional entanglement concentration residing in the OAM subspace of up to 21 dimensions. By means of LabVIEW simulations with spatial light modulators, we show that the Shannon dimensionality could be employed to quantify the quality of the present concentration. Our scheme holds promise in quantum information applications defined in high-dimensional Hilbert space.
Bacterial wilt: the disease and its causative agent, Pseudomonas solanacearum. (1994)

Bacterial wilt is an important disease that limits the production of many crop plants in the warm temperate, subtropical and tropical regions of the world. Few other plant diseases are comparable in terms of diversity of host range and wide geographic distribution, as well as of economic importance. Host plants include banana, eggplant, ginger, peanut, pepper, potato, tobacco and tomato. This book is the first to provide a general but comprehensive review of the disease and the bacterium that causes it. It considers topics ranging from taxonomy, phylogeny and genetics, to control strategies, and provides up-to-date information on recent advances derived from molecular biological approaches. The bacterium is also increasingly being used as a model system for the study of host-parasite interactions. Therefore the book represents a standard reference volume for both bacteriologists and plant pathologists.
A Technical and Economical Evaluation of Steam Foam Injection Based on a Critical Analysis of Field Applications (1996)

Abstract The use of foam to improve sweep efficiency during gas or steam injection has been studied since the end of the 50s. Foam reduces the mobility of gas or steam and this effect is amplified when the permeability increases, thereby correcting the effect of heterogeneity. However, although the consequences of the process are now generally recognized, it is still impossible to quantify them in terms of increase in oil production or reduction of quantities of gas/steam injected. The analysis of the field tests that have been performed in the past 20 years can help in the quantification and forecast of foam performance. This paper presents conclusions resulting from a comprehensive analysis of steam-foam field tests. They show that, at the present time, steam-foam injection is most efficient in layered reservoirs. Injection of slugs of surfactant with steam in this type of reservoirs can yield an average 3.9bbl of incremental oil per kilogram of surfactant injected. The process is economically attractive even in these times of low oil prices, with a cost of $2 to $3 per barrel of incremental oil. Continuous injection of surfactant with steam, more adapted to in-depth mobility control in non-stratified, heterogeneous reservoirs. It is a much less efficient method, with an average efficiency of 0.3 bbl of incremental oil per kilogram of surfactant injected, and is not economical. Finally, guidelines for the design of steam-foam injection tests are provided, and injection pressure during steam-foam is related to steam quality and concentration of the surfactant.
Relative debugging for data-parallel programs: a ZPL case study (2000)

Relative debugging is a powerful paradigm that lets us locate errors in programs that result from porting or rewriting code. The authors describe their experience using relative debugging to compare a program written in a sequential language with one that was ported to the data-parallel language ZPL.
Biodegradation of Synthetic Polymers Containing Ester Bonds (1990)

Oligomers of synthetic polymers are biodegradable, whereas only few polymers are biodegradable. Polyethylene adipate with Mn 3000 and polycaprolactone with Mn 25,000 were completely degraded by Penicillium spp. Aliphatic and alicyclic polyesters, ester type polyurethanes (I), copolyamide-esters (II) and copolyesters (III) of aliphatic and aromatic polyesters were hydrolyzed by lipases from various microorganisms and hog pancreas, and hog liver esterase. When aliphatic polyesters were used as enzyme substrates, it was found that their melting points (Tm) had a effect, in addition to their chemical structure, on biodegradability. It was assumed that the hydrogen bonds in the I, II chains and aromatic ring in the III chains, which were related to high Tm of I, II and III, influenced their biodegradation by lipases.
Anionic polymerization of monomers containing functional groups, 11. Anionic polymerizations of alkynyl methacrylates (1998)

Anionic polymerization of 2-propynyl methacrylate (1), 3-trimethylsilyl-2-propynyl methacrylate (2), 2-butynyl methacrylate (3), and 3-pentynyl methacrylate (4) was carried out in tetrahydrofuran at −78°C for 1 h. The employed initiator systems were (diphenylmethyl)potassium/diethylzinc (Et2Zn) and 1,1-bis(4′-trimethylsilyphenyl)-3-methylpentyllithium/lithium chloride (LiCl). Although poly(1) was obtained quantitatively with each initiator system, the observed molecular weights were always higher than the predicted values and the molecular weight distributions were rather broad (M̄w/M̄n > 1.3), indicating a side reaction at the acidic acetylenic proton. On the other hand, the polymerization of 2–4, i.e., methacrylate monomers having no terminal acetylenic protons in the ester moieties, proceeded quantitatively under similar conditions. The resulting poly(2–4)s were found to possess the predicted molecular weights and narrow molecular weight distributions (M̄w/M̄n < 1.1), indicating the living character of the polymerization systems. The trimethylsilyl protecting group of poly(2) was completely removed to form a poly(1) having well-defined chain structures by treating it with potassium carbonate in a mixed solvent of THF and methanol at room temperature for 1 h.
An object-oriented VHDL design environment (1990)

A system-level design environment (SDE) for the VHSIC hardware description language (VHDL) is presented. The object-oriented approach is used for modeling the VHDL entities, design constraints, and even design patterns. The data model and its internal schema, which are suitable for the VHDL semantics, are proposed. SDE allows a designer to reconfigure the designed schematic by binding its generic components to technology-specific ones. It is effectively used for version control. SDE verifies the design by dynamically checking the constraints. The standard VHDL is extended in order to represent the constraints properly. >
Improving Flooding Performance for Countercurrent Monolith Reactors (2004)

The limiting factors on the flooding performance of monoliths have been investigated in detail. In addition to the channel size and the void fraction of the monolith itself, the flooding limits are strongly impacted by inlet and outlet effects of the reactor bed as well as the stacking of monolith segments. Solutions to overcome these additional hydraulic restrictions, based on stacking slices of high-void-fraction monoliths with strategic step changes in cell density, are identified and evaluated. Implementation of the improvements allowed for the countercurrent operation of monoliths with a channel size as small as 1.25 mm even when a high-surface-tension liquid (water) is used. With the enhanced configurations, flooding experiments over a wide range of channel geometries of single and multiple monoliths were performed. Results from small-scale testing are in fair agreement with those obtained from the large-diameter tests, indicating a good scale-up behavior of the technology. The flooding limits are conveniently described with a flooding correlation based on an adjusted capacity plot taking the geometry properties of the monolith into account: = −0.025 + 0.12FLG-0.475 for 0.1 ≤ FLG ≤ 10. The measured flooding performance is in good agreement with recently reported data for flooding investigations of a falling film in an annular-flow configuration (Stockfleth, R.; Brunner, G. Ind. Eng. Chem. Res. 2001, 40, 6014−6020) that were performed with a significantly larger hydraulic diameter (12.5 mm). Monoliths enable stable countercurrent film flow operation with capillary-sized channels (1.25−4.0 mm), which so far was not feasible for any other packing structure. The findings are summarized in a design guide for the configuration of a monolith reactor for countercurrent operation.