gebhart/patrepeval huggingface dataset:
Cardiovascular Magnetic Resonance (2009)

Extract Summary This chapter summarizes the contemporary clinical role of cardiovascular magnetic resonance (CMR) in clinical cardiology. Techniques are described which can be applied widely in the cardiovascular system, and these include assessment of anatomy and function, blood flow, ventricular volumes and mass, myocardial abnormality, and the response to stress. The longest established indications for CMR are anatomical, including the great vessels, congenital heart disease, pericardium, and cardiac masses, but more recently increasing importance has been placed on assessment of myocardial abnormality. This has opened up new avenues of infarction and viability assessment in coronary artery disease, and phenotyping in cardiomyopathy with distinct distribution patterns of abnormality. The prognostic value of myocardial fibrosis in these settings is now under investigation. CMR is also becoming more widely used to assess ischaemia, particularly with stress ventriculography and myocardial perfusion imaging. Both techniques have substantial clinical application, and the avoidance of X-ray exposure for high resolution myocardial perfusion imaging is very attractive. Coronary imaging is currently still limited to assessing the course of anomalous coronaries, for which it is ideally suited. Work in acute coronary syndromes has been promising with new techniques to assess areas at risk, as has the visualization of vessel wall changes for the earliest detection of atherosclerosis. Finally, interventional CMR continues to develop, but the question of whether MR might or might not replace X-ray based techniques remains an open long-term question.
Relevance of ultraviolet-induced N-ras oncogene point mutations in development of primary human cutaneous melanoma. (1996)

Intermittent or recreational exposure to sunlight is thought to contribute to development of human cutaneous melanoma. We investigated the incidence of ras oncogene mutation in human cutaneous melanoma in connection to sun-exposed body sites in the patient, using a large series of DNA samples derived from paraffin-embedded material as well as from fresh tumor samples and cell lines. We first show that, of the ras family, predominantly N-ras is activated (15%), whereas rarely H-ras or K-ras are mutated. The occurrence of N-ras mutations correlates with continuous exposure to sunlight of the primary tumor site. Of all tumors initiated on chronically sun-exposed body sites, 26% contained mutated N-ras, in contrast to 0% of sun-protected melanomas. Melanoma lesions obtained from patients from North or Central Europe contained fewer N-ras mutations (12%) as compared with patients from Australia (24%). Mutations were specifically associated with nodular melanoma and to a lesser extent with lentigo malignant melanoma. N-ras mutations did not correlate with metastasis or survival parameters. This study identifies a subset of cutaneous melanomas that contain in the primary lesion ultraviolet-induced N-ras mutations, which are maintained through further progression.
Bioactive Silk‐Based Nerve Guidance Conduits for Augmenting Peripheral Nerve Repair (2018)

Repair of peripheral nerve injuries depends upon complex biology stemming from the manifold and challenging injury-healing processes of the peripheral nervous system. While surgical treatment options are available, they tend to be characterized by poor clinical outcomes for the injured patients. This is particularly apparent in the clinical management of a nerve gap whereby nerve autograft remains the best clinical option despite numerous limitations; in addition, effective repair becomes progressively more difficult with larger gaps. Nerve conduit strategies based on tissue engineering approaches and the use of silk as scaffolding material have attracted much attention in recent years to overcome these limitations and meet the clinical demand of large gap nerve repair. This review examines the scientific advances made with silk-based conduits for peripheral nerve repair. The focus is on enhancing bioactivity of the conduits in terms of physical guidance cues, inner wall and lumen modification, and imbuing novel conductive functionalities.
Development and optimization of a stove-powered thermoelectric generator (2008)

Almost a third of the world's population still lacks access to electricity. Most of these people use biomass stoves for cooking which produce significant amounts of wasted thermal energy, but no electricity. Less than 1% of this energy in the form of electricity would be adequate for basic tasks such as lighting and communications. However, an affordable and reliable means of accomplishing this is currently nonexistent. The goal of this work is to develop a thermoelectric generator to convert a small amount of wasted heat into electricity. Although this concept has been around for decades, previous attempts have failed due to insufficient analysis of the system as a whole, leading to ineffective and costly designs. In this work, a complete design process is undertaken including concept generation, prototype testing, field testing, and redesign/optimization. Detailed component models are constructed and integrated to create a full system model. The model encompasses the stove operation, thermoelectric module, heat sinks, charging system and battery. A 3000 cycle endurance test was also conducted to evaluate the effects of operating temperature, module quality, and thermal interface quality on the generator's reliability, lifetime and cost effectiveness. The results from this testing are integrated into the system model to determine the lowest system cost in $/Watt over a five year period. Through this work the concept of a stove-based thermoelectric generator is shown to be technologically and economically feasible. In addition, a methodology is developed for optimizing the system for specific regional stove usage habits.
Targeting the maize T-urf13 product into tobacco mitochondria confers methomyl sensitivity to mitochondrial respiration. (1995)

The URF13 protein, which is encoded by the maize mitochondrial T-urf13 gene, is thought to be responsible for pathotoxin and methomyl sensitivity and male sterility. We have investigated whether T-urf13 confers toxin sensitivity and male sterility when expressed in another plant species. The coding sequence of T-urf13 was fused to a mitochondrial targeting presequence, placed under the control of the cauliflower mosaic virus 35S promoter, and introduced into tobacco by Agrobacterium tumefaciens-mediated transformation. Plants expressing high levels of URF13 were methomyl sensitive. Subcellular analysis indicated that URF13 is mainly associated with the mitochondria. Adding methomyl to isolated mitochondria stimulated NADH-linked respiration and uncoupled oxidative phosphorylation, indicating that URF13 was imported into the mitochondria, and conferred toxin sensitivity. Most control plants, which expressed the T-urf13c construct lacking the mitochondrial presequence, were methomyl sensitive and contained URF13 in a membrane fraction. Subcellular fractionation by sucrose gradient centrifugation showed that URF13 sedimented at several positions, suggesting the protein is associated with various organelles, including mitochondria. No methomyl effect was observed in isolated mitochondria, however, indicating that URF13 was not imported and did not confer toxin sensitivity to the mitochondria. Thus, URF13 confers toxin sensitivity to transgenic tobacco with or without import into the mitochondria. There was no correlation between the expression of URF13 and male sterility, suggesting either that URF13 does not cause male sterility in transgenic tobacco or that URF13 is not expressed in sufficient amounts in the appropriate anther cells.
Sub-centimeter micromachined electron microscope (1992)

A new approach for fabricating macroscopic (∼10×10×10 mm3) structures with micrometer accuracy has been developed. This approach combines the precision of semiconductor processing and fiber optic technologies. A (100) silicon wafer is anisotropically etched to create four orthogonal v-grooves and an aperture on each 10×12 mm die. Precision 308 μm optical fibers are sandwiched between the die to align the v-grooves. The fiber is then anodically bonded to the die above and below it. This procedure is repeated to create thick structures and a stack of 5 or 6 die will be used to create a miniature scanning electron microscope (MSEM). Two die in the structure will have a segmented electrode to deflect the beam and correct for astigmatism. The entire structure is ultrahigh vacuum compatible. The performance of a SEM improves as its length is reduced and a sub-cm 2 keV MSEM with a field emission source should have approximately 1 nm resolution. A low-voltage high-resolution MSEM would be useful for the examination of biological specimens and semiconductors with a minimum of damage. The first MSEM will be tested with existing 6 μm thermionic sources. In the future a micromachined field emission source will be used. The stacking technology presented in this paper can produce an array of MSEMs 1–30 mm in length with a 1 mm or larger period. A key question being addressed by this research is the optimum size for a low-voltage MSEM which will be determined by the required spatial resolution, field of view, and working distance.
Oil and Gas Produced Water Reuse: Opportunities, Treatment Needs, and Challenges (2021)

Advances in water treatment technologies paired with potential restrictions on oil and gas (O&G) produced water disposal could incentivize the beneficial reuse of treated produced water in the O&G industry. However, the remote nature of O&G operations limits the applicability of many of these solutions, which may be spatially inefficient, require operator supervision, or are ill-suited for the complex nature of produced water. Furthermore, the responsible, sustainable reuse of produced water as an alternative water source requires standardized analytical techniques for characterizing and determining the toxicity of treated produced water and improving our understanding of the fate and transport of various constituents. In the past decade, we made little progress in economically treating produced water for beneficial reuse outside of oilfield operations; the sole major breakthrough has been in the development of salt-tolerant fracturing chemicals that allow for reuse of produced water for fracking operations. Guided research should assist in the development of fit-for-purpose solutions to maximize the reuse of treated produced water. This is exemplified by the case studies presented here that detail currently operating treatment facilities for reclamation and reuse of produced water.
Hierarchical control for autonomous mobile robots with behavior-decision fuzzy algorithm (2003)

The authors propose a construction method of a behavior-decision system using fuzzy algorithms capable of expressing sequence flow which includes a mixture of both crisp and fuzzy processing. They also propose a method of tuning algorithms for giving robots the autonomous ability to judge purposes of actions like humans. In this method, an attempt is made to express ambiguous situations which a robot will encounter and behavior-decision algorithm flow by using the modified fuzzy algorithm with fuzzy branch controlled threshold, called a behavior-decision fuzzy algorithm. Results of computer simulations for a simple indoor environment and experiments using a real autonomous mobile robot are shown to prove the effectiveness of the proposed method.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
New Insights into the Genetic Organization of the FK228 Biosynthetic Gene Cluster in <i>Chromobacterium violaceum</i> No. 968 (2010)

The biosynthetic gene cluster of FK228, an FDA-approved anticancer natural product, was identified and sequenced previously. The genetic organization of this gene cluster has now been delineated through systematic gene deletion and transcriptional analysis. As a result, the gene cluster is redefined to contain 12 genes: depA through depJ, depM, and a newly identified pathway regulatory gene, depR.
Purification and Cloning of the GTP Cyclohydrolase I Feedback Regulatory Protein, GFRP (1996)

The activity of GTP cyclohydrolase I, the initial enzyme of the de novo pathway for biosynthesis of tetrahydrobiopterin, the cofactor required for aromatic amino acid hydroxylations and nitric oxide synthesis, is sensitive to end-product feedback inhibition by tetrahydrobiopterin. This inhibition by tetrahydrobiopterin is mediated by the GTP cyclohydrolase I feedback regulatory protein GFRP, previously named p35 (Harada, T., Kagamiyama, H., and Hatakeyama, K. (1993) Science 260, 1507-1510), and -phenylalanine specifically reverses the tetrahydrobiopterin-dependent inhibition. As a first step in the investigation of the physiological role of this unique mechanism of regulation, a convenient procedure has been developed to co-purify to homogeneity both GTP cyclohydrolase I and GFRP from rat liver. GTP cyclohydrolase I and GFRP exist in a complex which can be bound to a GTP-affinity column from which GTP cyclohydrolase I and GFRP are separately and selectively eluted. GFRP is dissociated from the GTP agarose-bound complex with 0.2 NaCl, a concentration of salt which also effectively blocks the tetrahydrobiopterin-dependent inhibitory activity of GFRP. GTP cyclohydrolase I is then eluted from the GTP-agarose column with GTP. Both GFRP and GTP cyclohydrolase I were then purified separately to near homogeneity by sequential high performance anion exchange and gel filtration chromatography. GFRP was found to have a native molecular mass of 20 kDa and consist of a homodimer of 9.5-kDa subunits. Based on peptide sequences obtained from purified GFRP, oligonucleotides were synthesized and used to clone a cDNA from a rat liver cDNA library by polymerase chain reaction-based methods. The cDNA contained an open reading frame that encoded a novel protein of 84 amino acids (calculated molecular mass 9665 daltons). This protein when expressed in Escherichia coli as a thioredoxin fusion protein had tetrahydrobiopterin-dependent GTP cyclohydrolase I inhibitory activity. Northern blot analysis indicated the presence of an 0.8-kilobase GFRP mRNA in most rat tissues, the amounts generally correlating with levels of GTP cyclohydrolase I and tetrahydrobiopterin. Thus, mRNA levels were relatively high in liver and kidney and somewhat lower in testis, heart, brain, and lung. These results suggest that GFRP is widely expressed and may play a role in regulating not only phenylalanine metabolism in the liver, but also the production of biogenic amine neurotransmitters as well as nitric oxide synthesis.
Agonists and Antagonists of Metabotropic Glutamate Receptors: Anticonvulsants and Antiepileptogenic Agents? (2005)

Anticonvulsant and neuroprotective effects of agonist and antagonist of metabotropic glutamate receptors (mGluRs) have been known for more than 10 years from multiple studies. However, it is not certain whether these candidate drugs are also antiepileptic and antiepileptogenic, as few studies included the chronic stages to determine whether spontaneous recurrent seizures could be prevented or stopped. Even in the acute stage, differences in experimental design such as timing and route of administration of candidate drugs, age, species and strain of experimental animal and experimental model make it difficult to determine the anticonvulsant and europrotective effects of each candidate drug. This paper, reviews in vivo neuropharmacological studies on agonsists and antagonists of mGluRs in different seizure and epilepsy models in last more than ten years. By combining with our neuropharmacological studies on the effect of mGluR agonists and antagonists in the mouse pilocarpine model of temporal lobe epilepsy, an ideal model for future development of mGluR agonists and antagonists as antiepileptogenic drugs will be proposed.
Hydroxytryptamines. Part III. Synthesis of an azepindole derivative by molecular rearrangement (1955)

J. Harley-Mason and A. H. Jackson, J. Chem. Soc., 1955, 374 DOI: 10.1039/JR9550000374
Kinetics of the Secondary Reaction of HF on Alumino-Silicates (1999)

Summary The standard description of HF acidizing chemistry clearly demonstrates a primary and secondary reaction of HF with alumino-silicates.1–7 Field experience has taught us that possible precipitation during the secondary reaction can adversely affect treatment success,8 especially in formations with high K-feldspar content or temperatures above 300°F. Recent work has also reported the existence of a tertiary reaction of HF with alumino-silicates.9 This paper reports the determination of the rate law for the secondary reaction and the kinetics for that reaction on kaolinite and feldspar over a broad temperature range. In addition, the kinetics of fluosilicate precipitation during the secondary reaction were studied and found to be fast but not instantaneous. These findings were made possible by recently applied experimental techniques including 19F nuclear magnetic resonance spectroscopy,9 fractional pore-volume flow experiments,10 and an accurate knowledge of the HF stoichiometry.11 Laboratory find- ings have been verified based on detailed analysis of flowback samples from field treatments.12 The reaction rate for the secondary reaction is much slower on feldspars than on clays. At temperatures below 125°F, the secondary reaction rate is very slow, which makes spent HF susceptible to fluosilicate precipitation if the HF is mixed with brines as it often is for disposal or injection well treatments. The difference in the kinetics between clays and feldspar allows one to design treatments at lower temperatures based on just the clay fraction. At temperatures above 150°F, the average mineralogy, clay mineralogy, and feldspar mineralogy should each be evaluated separately for potential fluosilicate precipitation. The fluid of choice is the one that passes all three conditions. The rate law indicates that the speed of the reaction is independent of HCl concentration and would proceed to completion even in the absence of HCl. Chemically, one can accomplish this effect by using water as a proton source and by adjusting the stoichiometry based on a previously reported equilibrium.11 The kinetics for fluosilicate precipitation were fast, but not instantaneous. At very high temperatures, the secondary reaction is fast enough that fluosilicate precipitations can largely be avoided. Unfortunately, the silica gel precipitation then occurs so close to the wellbore that damage to permeability will likely occur. The equations recently developed for the HF acidizing process have been incorporated into a fully kinetic geochemical radial flow simulator. Calculations performed with this simulator have confirmed that a good knowledge of the formation mineralogy and acidizing kinetics is necessary for proper optimization of HF acidizing treatments.
Imaging microseismic events by diffraction stacking with moment tensor inversion (2013)

Microseismic monitoring can greatly benefit from imaging events with low signal-to-noise ratio as the number of low signal events grows exponentially. Hence, developing a migration-type detection and location technique has a potential to greatly improve microseismic monitoring. We developed a new methodology using stacking of seismic phases and amplitudes along diffraction traveltime curves together with polarization correction by seismic moment tensor inversion. This provided a calibrated model and imaged the perforation shots as non-shear events. We processed one day of data from microseismic monitoring of shale stimulation. The induced events are mostly shear events forming trends along the maximum horizontal stress direction and above the injection intervals.
Feature-level sentiment analysis for Chinese product reviews (2011)

The sentiment analysis for English product reviews has been widely researched in recent years, followed with many important achievements. Due to the special language traits of Chinese, the study on Chinese product reviews is much more difficult than the former. In this work, we focus on the finer-grained sentiment analysis for Chinese product reviews, that is feature-level based sentiment analysis. We propose a hybrid method which combines association rules and point-wise mutual information to extract the product features, and then take advantage of the sentiment dictionary - HowNet to analyze the opinion orientation expressed on the product features. The experiment result obtained shows the effectiveness and efficiency of our approach.
Absolute Binding Free Energies:  A Quantitative Approach for Their Calculation (2003)

The computation of absolute binding affinities by molecular dynamics (MD) based free energy simulations is analyzed, and an exact method to carry out such a computation is presented. The key to obtaining converged results is the introduction of suitable, auxiliary restraints to prevent the ligand from leaving the binding site when the native ligand−receptor interactions are turned off alchemically. We describe a versatile set of restraints that (i) can be used in MD simulations, that (ii) restricts both the position and the orientation of the ligand, and that (iii) is defined relative to the receptor rather than relative to a fixed point in space. The free energy cost, ΔAr, for this set of restraints can be evaluated analytically. Although the techniques were originally developed for the gas phase, the resulting expression is exact, since all contributions from solute−solvent interactions cancel from the final result. The value of ΔAr depends only on the equilibrium values and force constants of the chosen harmonic restraint terms and, therefore, can be easily calculated. The standard state dependence of binding free energies is also investigated, and it is shown that the present approach takes this into account correctly. The analytical expression for ΔAr is verified numerically by calculations on the complex formed by benzene with the L99A mutant of T4 lysozyme. The overall approach is illustrated by a complete binding free energy calculation for a complex based on a simplified model for tyrosine bound to tyrosyl-tRNA-synthetase. The results demonstrate the usefulness of the proposed set of restraints and confirm that the calculated binding free energy is independent of the details of the restraints. Comparisons are made with earlier formulations for the calculation of binding free energies, and certain limitations of that work are described. The relationship between ΔAr and the loss of translational and rotational entropy during a binding process is analyzed.
Performance of particle swarm optimization techniques on papr reduction for OFDM systems (2008)

Partial transmit sequence (PTS) technique requires an exhaustive search over all combinations of allowed phase weighting factors, the search complexity increases exponentially with the number of sub-blocks. In this paper, a novel combing strategy that employs sub-block partition scheme and phase factors for PTS in orthogonal frequency division multiplexing (OFDM) system is proposed. We present an OFDM system, which through the use of sub-optimal PTS based on particle swarm optimization (PSO) algorithm, achieves low computation complexity to find optimum phase weighting factors and reduce the peak-to-average power ratio (PAPR). Furthermore, to work around potentially computational intractability, the proposed scheme exploits heuristics in consideration of both global and local exploration partial transmit sequence. Simulation results show that the proposed PSO-based PTS can efficiently find the optimum phase weighting factor, and can achieve the lower PAPR with moderate complexity.