gebhart/patrepeval huggingface dataset:
Remarkably Active Catalysts for the Electroreduction of O[sub 2] to H[sub 2]O for Use in an Acidic Electrolyte Containing Concentrated Methanol (2000)

Focusing on methanol tolerance, a series of heat‐treated metalloporphyrins were investigated by steady‐state voltammetry with a rotating disk electrode. The heat‐treated CoTPP/FeTPP (tetraphenylporphyrin) shows the optimum catalytic activity for oxygen reduction with an onset catalytic potential [0.9 V vs. reversible hydrogen electrode (RHE)] close to that of platinum black catalyst (1.0 V vs. RHE). However, the catalytic activity for oxygen reduction on platinum black catalyst is severely affected by the presence of 1.0 M methanol, resulting in a negative shift of the catalytic potential and a significant decrease in catalytic current. The catalytic activity for oxygen reduction on the heat‐treated metalloporphyrin is not appreciably affected by the presence of the same amount of methanol in an acidic electrolytic solution. The catalytic activity of the heat‐treated binary metalloporphyrin catalyst is better than that of only a heat‐treated single metalloporphyrin. The best heat‐treatment (HT) temperature for HT‐CoTPP/FeTPP is 600°C. The catalytic kinetic process is analyzed using various polarization curves for oxygen reduction at different rotation rates. The slopes obtained from the Koutecký‐Levich plots have verified that the heat‐treated metalloporphyrins can catalyze a four‐electron reduction of oxygen to water over a wide potential range. © 2000 The Electrochemical Society. All rights reserved.
Un vistazo a ping (2006)

?Intenta averiguar si su portatil esta conectado a la red de su casa u oficina? Hagale ping.
Glucose /Oxygen Sensor (1987)

Oxygen concentration has been measured using fluorescence quenching in solid polymer hosts. The feasibility of generalizing these oxygen transducers to a wider class of chemical sensors through coupling to other chemistries is proposed. An example of such coupling is given in a glucose/oxygen transducer. The glucose transducer is produced by entrapping an enzyme, glucose oxidase, in' the composite matrix of a hydrophilic oxygen transducer. Glucose oxidase catalyzes a reaction between glucose and oxygen, thereby lowering the local oxygen concentration. This transducer yields a glucose modified optical oxygen signal. The specific focus of this research is the development of a theoretical model that describes the coupling of glucose concentration to relative fluorescence intensity, the experimental measurement of the key parameters in this model, and the evaluation of the sensitivity of the variation in relative fluorescence intensity with changes in glucose concentration. The experimental parameters include the diffusivity of oxygen in PHEMA (1.36 x 10-7 cm2/s), the solubility ofoglucose in PHEMA (0.24 g in PHEMA/g in buffer), and the diffusivity of glucose in PHEMA (8.25 x 10-8 cm2/s). When these experimental parameters are incorporated, the model developed predicts critical design requirements of the transducer.
Effects of Monovalent and Divalent Anionic Dodecyl Sulfate Surfactants on the Dediazoniation of 2-, 3-, and 4-Methylbenzenediazonium Tetrafluoroborate (1998)

We have examined the kinetics and mechanism of dediazoniation of 2-, 3- and 4-methylbenzenediazonium tetrafluoroborate (OMBD, MMBD, and PMBD) in aqueous micellar solutions of sodium dodecyl sulfate and copper dodecyl sulfate at two different NaCl concentrations by combining spectrophotometric and high-performance liquid chromatography (HPLC) measurements. The method allows simultaneous determination of product yields and rates of formation for all dediazoniation products and, indirectly, the rate of decomposition of the diazonium salt. The preferential location of OMBD, MMBD, and PMBD is in the Stern layer, a very anisotropic region. A substantial fraction of diazonium ions are bonded to the micellar aggregates, and formation of strong ion pairs between OMBD, MMBD, and PMBD diazonium salts with the sulfate headgroup of the surfactants is not significant. HPLC analysis of dediazoniation products indicates that, within experimental error, quantitative conversion to products is achieved, with cresol as the major product. Observed rate constants for the dediazoniation reaction in the presence of both monovalent and divalent surfactants are constant for OMBD but decrease slightly for MMBD and PMBD with increasing surfactant concentration. The data are interpreted in terms of the polarity of the environment of diazonium salts in the micellar aggregate. All evidence is consistent with an Dn + An mechanism, i.e., rate-determining formation of an aryl cation that reacts immediately with any available nucleophile.
A Ground-Lightning Environment for Engineering Usage (1972)

Abstract : Data on lightning incidence are first examined. Expressions are derived relating lightning incidence to the monthly thunderstorm-day statistic, to diurnal variation of activity, and to structure height. By using these expressions the number of lightning strikes to be expected over any period of time can be estimated, on a climatological basis, for a structure of known height located anywhere in the world. The following physical parameters of lightning are then discussed: peak current, time to peak current, rate of current rise, magnitude and duration of continuing currents, total charge transfer, number of strokes, and time between strokes. Median values and statistical distributions for the parameters are deduced; the statistics can usually be conveniently expressed in terms of a log-normal law. Several models for lightning are derived and expressed in convenient analytical forms. Two types of models are identified--basic models developed solely from the physical properties of lightning, and applied models modified appropriately for use with equipment, the lightning sensitivity of which is partially defined. While the main emphasis of the report is on the direct effects of flashes to ground, discussions are also given of the physical characteristics of intracloud discharges, and of the static and electromagnetic fields generated by lightning.
Nesting of reducible and irreducible loops (1997)

Recognizing and transforming loops are essential steps in any attempt to improve the running time of a program. Aggressive restructuring techniques have been developed for single-entry (reducible) loops, but restructurers and the dataflow and dependence analysis they rely on often give up in the presence of multientry (irreducible) loops. Thus one irreducible loop can prevent the improvement of all loops in a procedure. This article give an algorithm to build a loop nesting tree for a procedure with arbitrary control flow. The algorithm uses definitions of reducible and irreducible loops which allow either kind of loop to be nested in the other. The tree construction algorithm, an extension of Tarjan's algorithm for testing reducibility, runs in almost linear time. In the presence of irreducible loops, the loop nesting tree can depend on the depth-first spanning tree used to build it. In particular, the header node representing a reducible loop in one version of the loop nesting tree can be the representative of an irreducible loop in another. We give a normalization method that maximizes the set of reducible loops discovered, independent of the depth-first spanning tree used. The normalization require the insertion of at most one node and one edge per reducible loop.
Solution structure and thermal stability of ribosomal protein L30e from hyperthermophilic archaeon <i>Thermococcus celer</i> (2003)

To understand the structural basis of thermostability, we have determined the solution structure of a thermophilic ribosomal protein L30e from Thermococcus celer by NMR spectroscopy. The conformational stability of T. celer L30e was measured by guanidine and thermal-induced denaturation, and compared with that obtained for yeast L30e, a mesophilic homolog. The melting temperature of T. celer L30e was 94 degrees C, whereas the yeast protein denatured irreversibly at temperatures >45 degrees C. The two homologous proteins also differ greatly in their stability at 25 degrees C: the free energy of unfolding was 45 kJ/mole for T. celer L30e and 14 kJ/mole for the yeast homolog. The solution structure of T. celer L30e was compared with that of the yeast homolog. Although the two homologous proteins do not differ significantly in their number of hydrogen bonds and the amount of solvent accessible surface area buried with folding, the thermophilic T. celer L30e was found to have more long-range ion pairs, more proline residues in loops, and better helix capping residues in helix-1 and helix-4. A K9A variant of T. celer L30e was created by site-directed mutagenesis to examine the role of electrostatic interactions on protein stability. Although the melting temperatures of the K9A variant is approximately 8 degrees C lower than that of the wild-type L30e, their difference in T(m) is narrowed to approximately 4.2 degrees C at 0.5 M NaCl. This salt-dependency of melting temperatures strongly suggests that electrostatic interactions contribute to the thermostability of T. celer L30e.
Bismuth Formation in Lead-Free Cu–Zn–Si Yellow Brass with Various Bismuth–Tin Alloy Additions (2018)

Typically, bismuth added in traditional Cu–Zn brass segregates as films or particles along the alpha-beta phase boundary and induces cracks after casting. The present work investigated the bismuth formation in lead-free Cu–Zn–Si yellow brass with various amounts of recycled bismuth–tin (Bi–Sn) solder. The results showed that no bismuth film segregated at the phase boundaries. In contrast, round particles of bismuth formed in the beta phase and at the alpha-beta phase boundaries when added 1 mass% Bi–Sn alloy and the bismuth particles embedded only in the alpha phase when added 2 to 4 mass% Bi–Sn alloy, respectively. The morphology of the fracture surfaces was significantly modified when Bi–Sn alloy content was increased. More importantly, there was no crack observed in as-cast samples and samples did not subject to any heat treatment process unlike the bismuth formation in other work. Thus, this work suggests that the addition of recycled Bi–Sn solder in lead-free Cu–Zn–Si yellow brass is beneficial to avoid cracks in castings and offer an original lead-free brass alloy with superior properties.
ABT-737 Synergizes with Cisplatin Bypassing Aberration of Apoptotic Pathway in Non-small Cell Lung Cancer (2017)

A subset of non-small cell lung cancer (NSCLC), which does not have a druggable driver mutation, is treated with platinum-based cytotoxic chemotherapy, but it develops resistance triggered by DNA damage responses. Here, we investigated the effect of activation of STAT3 by cisplatin on anti-apoptotic proteins and the effectiveness of a co-treatment with cisplatin and a BH3 mimetic, ABT-737. We analyzed the relationship between cisplatin and STAT3 pathway and effect of ABT-737, when combined with cisplatin in NSCLC cells and K-ras mutant mouse models. The synergism of this combination was evaluated by the Chou-Talalay Combination Index method. In vivo activity was evaluated by micro-CT. In NSCLC cells, there was a time and dose-dependent phosphorylation of SRC-JAK2-STAT3 by cisplatin, followed by increased expression of anti-apoptotic molecules. When the expression of the BCL-2 protein family members was evaluated in clinical samples, BCL-xL was most frequently overexpressed. Dominant negative STAT3 suppressed their expression, suggesting that STAT3 mediates cisplatin mediated overexpression of the anti-apoptotic molecules. ABT-737 displaced BCL-xL from mitochondria and induced oligomerization of BAK. ABT-737 itself showed cytotoxic effects and a combination of ABT-737 with cisplatin showed strong synergistic cytotoxicity. In a murine lung cancer model, co-treatment with ABT-737 and cisplatin induced significant tumor regression. These findings reveal a synergistic cytotoxic and anti-tumor activity of ABT-737 and cisplatin co-treatment in preclinical models, and suggest that clinical trials using this strategy may be beneficial in advanced NSCLC.
A double-MOSFET switched-capacitor auto-tuned high frequency filter (2002)

This paper proposes an auto-tuned high frequency low distortion double-MOSFET filter. A 7 MHz fourth-order Butterworth lowpass filter for a disk-drive servo PES (Position Error Signal) system is designed and laid out using a single power supply 5 V 0.8 /spl mu/m DPDM (double-poly double-metal) N-well CMOS technology. The f/sub 3dB/ cutoff frequency tolerance is 1.1% simulated according to process variation and temperature change in the 0/spl deg/-75/spl deg/C range. The active area, including biasing, the double-MOSFET SC tuned system, and the filter, is 0.8 mm/spl times/1.3 mm, and the filter consumes 68 mW.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Pseudobase Formation from Quaternary Pyridinium, Quinolinium and Isoquinolinium Cations (1977)

A review of recent studies of addition reactions of the hydroxide ion with some quaternary aromatic nitrogen compounds has been presented.1. Introduction 2 .1-Substituted Pyridinium Ion 3. 1-Substituted Quinolinium Ion 4 .2-Substituted Isoquinolinium and 3,4-Dihydroisoquinolinium Ion 5 .5.6-Dihydrodibenzo/a,g/quinolizinium Ion 6. 5-Substituted Benzo/c/phenanthridinium Ion 7. Conclusion 8. References
Porosity decrease in laser welds of stainless steel using plasma control (1983)

High energy laser welding incorporating plasma control has been studied and reported by numerous investigators. These investigators demonstrated significant increases in laser weld penetration by use of plasma control. In this report we show, in addition to variations in weld penetration, drastic decrease in porosity and variation in weld bead shapes resulting from laser welds incorporating plasma control. In particular, deep laser welds (greater than 6 mm) have been produced in 304L stainless steel that show no root porosity and only very few, if any, detectable micropores.
Qwerty versus Alphabetic Keyboards as a Function of Typing Skill (1971)

A comparison was made of performance on two keyboards, a three-row alphabetic arrangement (ALPHA) and the standard typewriter array (QWERTY). Thirty subjects who ranged in typing skill from almost none to secretarial level operated the keyboards for ten half-hour sessions. Half of the subjects started on ALPHA and half on QWERTY, switching from one keyboard to the other after five sessions. Input material was a list of names and addresses taken from telephone directories. Keying rates and work output, as measured by the number of names and addresses correctly keyed, was found to be greater for skilled and semiskilled typists on the QWERTY keyboard. Performance on the two keyboards was essentially equal for unskilled typists.
Are Organisations Prepared for Crisis?: An Evaluation of Crisis Planning in the Accommodation Industry in Australia (2011)

Crisis planning is expected to be an important strategy in business in turbulent times and it could determine the sustainable development of organisations. However, the majority of the accommodation crisis management studies are concerned with crisis response or recovery rather than crisis planning. Furthermore, only a limited number of former studies used quantitative methods to inform accommodation crisis planning, and few are explanatory. With the aim of evaluating the current level of crisis planning, as well as the relationship between organisational factors and crisis planning and crisis preparedness within the accommodation industry in Australia, an online survey was used to measure managers' perceptions of their organisations' level of crisis planning and crisis preparedness. In the sample of 384 managers surveyed, two thirds of respondents indicated that their organisation had undertaken crisis planning activities in the past six months. This study found strong support for the hypotheses that organisational type and organisation size had an impact on the implementation of crisis planning and the perceived level of crisis preparedness. It also found support for the hypothesis that increasing organisational age is associated with increasing crisis planning activities; however, increasing age is not associated with increasing crisis preparedness. Data on these relationships are useful in determining which factors influence accommodation crisis planning and offer suggestions for accommodation operators interested in increasing their crisis preparedness.
Emergency peripartum hysterectomy: Incidence, indications, risk factors and outcome (2011)

Emergency peripartum hysterectomy is a most demanding obstetric surgery performed in very trying circumstances of life threatening hemorrhage. The indication for emergency peripartum hysterectomy in recent years has changed from traditional uterine atony to abnormal placentation. Antenatal anticipation of the risk factors, involvement of an experienced obstetrician at an early stage of management and a prompt hysterectomy after adequate resuscitation would go a long way in reducing morbidity and mortality.
A simple and flexible driver for OLED (2003)

A microcontroller-based driver was designed and developed for dot-matrix displays made with organic light emitting diodes (OLEDs). It was made by modifying driver designed for dot matrix LEDs made with inorganic semiconductors. The driver was designed with adjustable driving frequency, pulse-width, polarity and pulse-amplitude. It is a generalized driver suitable for operating OLED dot matrices made with different electroluminescent organic materials or in different device structures. A driver system was fabricated to drive an OLED panel in 40/spl times/7 format.
Circulating Cell-Free DNA: The Blood Biopsy in Cancer Management (2015)

Currently, tissue biopsy, generally from the primary tumor, is used to determine molecular profiles at a single time point, before targeted therapy commences. Tissue biopsies carry some risks for patients, they are painful, costly, time-consuming, and most importantly, may not be a true representation of tumor heterogeneity. Tumor genomes are remarkably unstable and prone to clonal expansion under selection pressure, blood biopsies via circulating cell-free DNA (cfDNA) offer what tissue biopsies can’t, the opportunity to take serial samples for longitudinal monitoring of tumor genomic evolution in real time. Blood biopsy-based testing will allow clinicians to ensure treatment efficacy, monitor drug resistance, metastasis and recurrence, tailoring patients to the right treatment for the right target without delay. Tumor genome sequencing on circulating cfDNA to guide treatment decisions would be the standard-of-care of new-generation cancer management. In this review, we will briefly discuss cfDNA and its advantage over tissue biopsy, challenges and future perspectives for cancer management.
Filtering and System Identification (2007)

Filtering and system identification are powerful techniques for building models of complex systems. This 2007 book discusses the design of reliable numerical methods to retrieve missing information in models derived using these techniques. Emphasis is on the least squares approach as applied to the linear state-space model, and problems of increasing complexity are analyzed and solved within this framework, starting with the Kalman filter and concluding with the estimation of a full model, noise statistics and state estimator directly from the data. Key background topics, including linear matrix algebra and linear system theory, are covered, followed by different estimation and identification methods in the state-space model. With end-of-chapter exercises, MATLAB simulations and numerous illustrations, this book will appeal to graduate students and researchers in electrical, mechanical and aerospace engineering. It is also useful for practitioners. Additional resources for this title, including solutions for instructors, are available online at www.cambridge.org/9780521875127.
Detoxification of electrophilic compounds by glutathione S‐transferase catalysis: Determinants of individual response to chemical carcinogens and chemotherapeutic drugs? (2003)

The glutathione S-transferases (GSTs) catalyze the GSH-dependent detoxification of reactive electrophiles such as genotoxic chemical carcinogens and cytotoxic chemotherapeutic agents. Allelic polymorphism in the GSTs has been used to investigate the hypothesis that GSTs are involved in susceptibility to human cancers. Such studies have resulted in low penetrance, high prevalence associations between cancer risk and GST polymorphisms. By examination of interindividual variation of GST expression it becomes clear that GST genotype alone is not an accurate predictor of GST expression. GST expression is tissue specific and interindividual variation of expression is at least 7-fold in normal tissues. Thus, populations of the same genotype are actually heterogeneous as regards expression. Similarly, polymorphisms are not effective in all tissues and GST induction is not independent of genotype. Mechanistic models for chemical aspects of colorectal cancer and chemotherapy for breast cancer demonstrate some of the ways by which such interactions can be studied and the potential for future studies.
Using the Micro (1985)

BASIC is the most popular programming language because it is the most conversational and so the easiest to read and understand. BASIC comes in many dialects to suit individual micros, but conversation between one dialect and another is a relatively simple task.
Democracia, escuelas inteligentes y ciudadanía (2006)

Iniciar una investigación que tenga que ver con democracia, usando experiencias del proceso educativo formal, requiere unas premisas básicas que tienen que ver no solo con la pedagogía como ciencia, sino también con una disposición del espíritu que se ha denominado justicia. La justicia tiene que ver con la bondad, la tolerancia, el reconocimiento de los méritos, la proporcionalidad, la solidaridad, el equilibrio, la honestidad, la rectitud, la responsabilidad, en síntesis, con todo lo que tiene que ver con el respeto y el ejercicio de la dignidad humana. No se trata de una opción a ser considerada sólo por personas caritativas y sensibles, en cuanto a su ayuda al prójimo, sino de una disposición que debe obligar a cada persona a reconocer el valor propio de cualquier semejante. En este sentido estamos en el campo de la ética y por el lado de la escuela en el del desarrollo moral como uno de los planteamientos necesarios de la escolaridad.
Mechanistic Studies on Thiazolidine Formation in Aldehyde/Cysteamine Model Systems (1998)

A mechanism was proposed to elucidate the formation of a thiazolidine in aldehyde/cysteamine model systems. Buffer dramatically promotes thiazolidine formation from formaldehyde and cysteamine. Phosphate tends to stabilize the primary carbocation formed, and this may lead to completion of the cyclization by attack of the amino nitrogen on the activated carbon. Protic solvent, by removing the water molecule, further enhances thiazolidine formation. Redox reaction catalyzed by phosphate ions results in the conversion of thiazolidine to the corresponding thiazoline through hydride transfer.