gebhart/patrepeval huggingface dataset:
Alkaline degradation of clavulanic acid and high performance liquid chromatographic determination by post-column alkaline degradation. (1983)

Alkaline degradation of clavulanic acid in methanol and in aqueous solution has been investigated. Potassium clavulanate was degraded in methanol and in NaOH-saturated methanol to yield methyl 8-hydroxy-6-oxo-4-aza-2-octenoate (I). which showed ultraviolet (UV) absorption with λmax 268nm (methanol). The UV absorption of I almost disappeared in acidic conditions, and reappeared on subsequent realkalization, suggesting interconversion between I and its protonated form. It was suggested that potassium clavulanate might be rapidly hydrolyzed in alkaline aqueous solutions to 8-hydroxy-6-oxo-4-aza-2-octenoic acid (II), which has strong UV absorption around 260 nm. The acid-base interconversion was also observed between II and its protonated form, the latter exhibiting almost no UV absorption around 260 nm. An ion-pair reversed-phase high performance liquid chromatography method with the alkaline degradation reaction incorporated into post-column has been developed for the determination of clavulanic acid in plasma and urine. After separation from regular components of plasma and urine, clavulanic acid is degraded in NaOH solution in a reaction coil followed by detection of the UV absorbance of the degradation product at 270 nm. The procedure was quantitative over a wide range of clavulanic acid concentrations in plasma and urine down to 0.1 μg/ml.
Single-longitudinal mode Nd:YVO4/YVO4/KTP green solid state laser (2009)

Abstract We present the concept and practical realization of a single frequency, tuneable diode pumped Nd:YVO4/YVO4/KTP microchip laser operating at 532 nm. Theoretical analysis of the single mode operation of such a laser configuration is presented. The single frequency operation has been obtained in a birefringent filter, where an YVO4 beam displacer acts as an ideal polarizer. Experimental results are in good agreement with theoretical analysis. We have obtained stable single frequency operation, tuneable over 0.6 nm in the spectral range around 1064 nm. The laser operated with output power up to 110 mW at 53 nm. The total optical efficiency (808 nm to 532 nm) was 14%.
Ischemic preconditioning procedure induces behavioral deficits in the absence of brain injury? (2005)

Preconditioning describes a phenomenon whereby a sub-injury inducing insult can protect against a later larger injury. Thus, short-term cerebral ischemia can protect against a prolonged ischemia (ischemic preconditioning). This study examines rats undergoing ischemic preconditioning to test whether preconditioning may cause changes in behavior even though they do not cause an identifiable brain lesion. Rats had a transient (15 minutes) middle cerebral artery occlusion or a sham occlusion. Forelimb placing and forelimb use asymmetry tests were used to assess behavioral deficits. Brain histology, microglia activation, heat shock protein and ferritin levels were also examined. Ischemic preconditioning did not cause brain infarction, but induced behavioral changes. There were no significant differences between ischemic preconditioning and sham rats in the two behavioral tests at day one. However, the ischemic preconditioning group showed impaired forelimb placing at days 3, 7 and 14 (p<0.05). That group also had a significant (p<0.05) behavioral deficit in the forelimb use asymmetry test at days 3 and 7 (but not 14). Our present study demonstrated that a behavioral deficit occurred in ischemic preconditioning. This raises the question of whether induction of protective mechanisms by preconditioning stimuli necessarily involves some form of brain injury, detectable by changes in behavior though not by a lesion. This would be consistent with data suggesting that brain injury can initiate mechanisms potentially favorable to neuroplasticity and neuroprotection.
Rapid quantification of regurgitant flow through mitral valve models using the control volume method with segmented k-space magnetic resonance velocimetry (2002)

New approaches for the assessment of mitral regurgitation have focused on the quantification of the regurgitant flow volume, but they are accompanied by uncertainties. Recently, a control volume (CV) method applied via multi-slice and 3-directional magnetic resonance phase velocity mapping (MRPVM) showed potential for accurate quantification of the regurgitant volume. A limitation of conventional non-segmented MRPVM is its relatively long scan time. With the development of new rapid segmented k-space sequences, fast velocity measurements have become possible. The aim of this study was to evaluate in vitro the accuracy of segmented k-space MRPVM in quantifying the regurgitant volume using the CV method. Four mitral regurgitant orifices were tested under a variety of flow conditions. Five contiguous slices were placed in the sagittal direction and all three velocity components were measured with a segmented MRPVM sequence with nine lines per segment. Non-segmented MRPVM measurements were also performed to provide reference data. Rotameter readings provided true flow rates. Comparison between the segmented MRPVM results and the true flow rates showed close agreement when a medium-sized CV was used (> 0.5 cm in all directions). With a very small CV, significant errors were introduced because of aliasing and rapid acceleration very close to the orifice.
Multiple-Valued Computing Using Field Emission - Based Carbon Nanotube Controlled Switching (2010)

Abstract- A new carbon nanotube (CNT)- based controlled switch is introduced. The new CNT device is a field emission – based device that uses field electron emission from the CNT to implement the functionality of controlled switching. To implement the field emission CNT controlled switch, four field emission CNTs that have single carbon nanotubes as the emitters were tested; two with single-walled CNT and two with multi-walled CNT. A tube with a tungsten tip was also used for comparison. The Fowler-Nordheim analysis of the DC currentvoltage data provided reasonable values for the local fields at the emitters and the sizes of the emitters. It is also shown within the new implementation of the controlled switch that squarewave pulses from a single laser diode with 20 mW power and 658 nm wavelength which is focused on each emitter increased the emitted current by 5.2 % with the CNT and 0.19 % with the compared tungsten tip. The extension of the new device from the two-valued to the general m-valued case is introduced, and the implementation of multiple-valued Galois circuits and systems utilizing the new CNT field emission – based device is also shown. Since the controlled switch is a basic block in the design of modern digital systems, the new CNT device can have a wide range of applications in a wide variety of nano circuits.
ChemInform Abstract: SYNTHESIS OF PYRROLIDINE DERIVATIVES WITH PHARMACOLOGICAL ACTIVITIES. PART VII. ANTICHOLINERGIC AGENTS. SYNTHESIS OF 1,1,4‐TRIMETHYL‐ AND 1,1,5‐TRIMETHYL‐3‐DIPHENYLMETHYLENEPYRROLIDINIUM HALIDES (1976)

Abstract Die Diphenylmethylenbernsteinsäuren (I) werden mit Aminen (II) zu den Succinimiden (III) cyclisiert und nach der Reduktion zu Pyrrolidinen N‐methyliert.
Kinetics of tetramolecular quadruplexes (2005)

The melting of tetramolecular DNA or RNA quadruplexes is kinetically irreversible. However, rather than being a hindrance, this kinetic inertia allows us to study association and dissociation processes independently. From a kinetic point of view, the association reaction is fourth order in monomer and the dissociation first order in quadruplex. The association rate constant k (on), expressed in M(-3) x s(-1) decreases with increasing temperature, reflecting a negative activation energy (E (on)) for the sequences presented here. Association is favored by an increase in monocation concentration. The first-order dissociation process is temperature dependent, with a very positive activation energy E (off), but nearly ionic strength independent. General rules may be drawn up for various DNA and RNA sequence motifs, involving 3-6 consecutive guanines and 0-5 protruding bases. RNA quadruplexes are more stable than their DNA counterparts as a result of both faster association and slower dissociation. In most cases, no dissociation is found for G-tracts of 5 guanines or more in sodium, 4 guanines or more in potassium. The data collected here allow us to predict the amount of time required for 50% (or 90%) quadruplex formation as a function of strand sequence and concentration, temperature and ionic strength.
Selective Stabilization of DNA Triple Helixes by Benzopyridoindole Derivatives (1995)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSelective Stabilization of DNA Triple Helixes by Benzopyridoindole DerivativesChristophe Escude, Chi Hung Nguyen, Jean-Louis Mergny, Jian-Sheng Sun, Emile Bisagni, Therese Garestier, and Claude HeleneCite this: J. Am. Chem. Soc. 1995, 117, 41, 10212–10219Publication Date (Print):October 1, 1995Publication History Published online1 May 2002Published inissue 1 October 1995https://pubs.acs.org/doi/10.1021/ja00146a006https://doi.org/10.1021/ja00146a006research-articleACS PublicationsRequest reuse permissionsArticle Views276Altmetric-Citations56LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Using Twitter to Characterize Public Opinion in Brazil During Political Events (2022)

In this work, the authors characterize Brazilian online population sentiment on different political events using data from Twitter and discuss the advantages of the usage of this social media as a data source. The results demonstrated that the Brazilian population uses Twitter to manifest their political view, expressing both positive and negative sentiments regarding political events. This kind of characterization may contribute to build a critical opinion of Brazilian people, once they would not be limited by what is being divulgated by typical media, such as television and newspapers. Additionally, the authors reinforced the applicability of social media, as Twitter, to make this kind of characterization.
BOUNDARY DOMINATED VERSUS BULK DOMINATED REGIME IN OPTICAL SPACE-TIME COMPLEXITY (1994)

By increasing the aspect ratio of an optical cavity with a photorefractive crystal, we observe the transition from a boundary-controlled regime, where the size of the transverse patterns scales with the aspect ratio, to a bulk-controlled regime where the pattern size is independent of the aspect ratio. In this new regime, the size corresponds to an intrinsic correlation length imposed by diffusion processes within the material. Such a new behavior is explained by the wave-number dependence of the gain within the instability region. Model equations provide good agreement with the two asymptotic cases of small aspect ratio (diffraction limited regime) and large aspect ratio (diffusion limited regime).
Functional Redundancy of FMRFamide-Related Peptides at theDrosophilaLarval Neuromuscular Junction (1998)

The Drosophila FMRFamide gene encodes multiple FMRFamide-related peptides. These peptides are expressed by neurosecretory cells and may be released into the blood to act as neurohormones. We analyzed the effects of eight of these peptides on nerve-stimulated contraction (twitch tension) of Drosophila larval body-wall muscles. Seven of the peptides strongly enhanced twitch tension, and one of the peptides was inactive. Their targets were distributed widely throughout the somatic musculature. The effects of one peptide, DPKQDFMRFamide, were unchanged after the onset of metamorphosis. The seven active peptides showed similar dose-response curves. Each had a threshold concentration near 1 nM, and the EC50 for each peptide was approximately 40 nM. At concentrations <0.1 microM, the responses to each of the seven excitatory peptides followed a time course that matched the fluctuations of the peptide concentration in the bath. At higher concentrations, twitch tension remained elevated for 5-10 min or more after wash-out of the peptide. When the peptides were presented as mixtures predicted by their stoichiometric ratios in the dFMRFamide propeptide, the effects were additive, and there were no detectable higher-order interactions among them. One peptide was tested and found to enhance synaptic transmission. At 0.1 microM, DPKQDFMRFamide increased the amplitude of the excitatory junctional current to 151% of baseline within 3 min. Together, these results indicate that the products of the Drosophila FMRFamide gene function as neurohormones to modulate the strength of contraction at the larval neuromuscular junction. In this role these seven peptides appear to be functionally redundant.
ChemInform Abstract: SYNTHESIS AND H2‐ANTIHISTAMINIC EFFECT OF N,N′‐BISHETEROARYL‐SUBSTITUTED CYANOGUANIDINES AND 2‐NITRO‐1,1‐ETHENEDIAMINES. 17. H2‐ANTIHISTAMINICS (1984)

In studies on structure-activity relationships of histamine H2-receptor antagonists, cyanoguanidines and 2-nitro-1,1-ethendiamines, which contain the heterocyclic rings of ranitidine and cimetidine twofold, were prepared and tested for their H2-antihistaminic activity on the isolated guinea-pig atrium and on the histamine stimulated acid secretion of the anaesthetized rat. While the N,N'-disubstituted keten-N,N-acetales 8 and 11 possess markedly stronger H2-antagonistic activity than Ranitidine, the analogously substituted cyanoguanidines 3b and 6 proved to be as effective as the reference substance. The substances 3a and 13, with unsubstituted C-5 position of one heterocyclus, showed lower potency.
ChemInform Abstract: Nonpeptidic HIV Protease Inhibitors: 6‐Alkyl‐5,6‐dihydropyran‐2‐ones Possessing a Novel and Achiral 3‐(2‐t‐Butyl‐5‐methyl‐4‐sulfamate)phenylthio Moiety. (1999)

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Clostridium difficile in pork and retail meat in Texas (2011)

The incidence and severity of disease associated with toxigenic Clostridium difficile (Cd) have increased in hospitals in North America from the emergence of newer, more virulent strains of Cd. Toxigenic Cd has been isolated from food animals and retail meat with potential implications of transfer to humans. The objective of the present study was to determine the prevalence of Cd in pork from sausage manufacturing plants and retail meat in Texas, and to compare two different enrichment techniques for isolation of Cd from meat. We detected 23 Cd isolates from 243 meat samples (9.5%) from three sausage manufacturing plants and five different retail meat outlets from 2004 to 2009. Twenty-two isolates were toxin A+, toxin B+, binary toxin+, and were characterized as toxinotype V, PFGE type-NAP7 or "NAP7-variant". Susceptibilities to 11 antimicrobial agents in this study were similar to those reported previously for toxinotype V isolates, although our results suggested somewhat less resistance than reported for other meat, animal, or human clinical toxinotype V isolates. Comparison of the enrichment techniques demonstrated that an extended enrichment of 15 days produced 23 isolates whereas a 7 day enrichment method produced 11 isolates (P = 0.03).
Role of Diastolic Stress Testing in the Evaluation for Heart Failure With Preserved Ejection Fraction (2016)

URL: http://www.clinicaltrials.gov. Unique Identifier: NCT01418248.
The Physiology and Biochemistry of Skeletal Muscle Atrophy as a Function of Age (1994)

The skeletal muscles are an important entity in the proper function of aging animals and humans. Studies have shown that until humans are 60-70 years old, age-related changes in muscle function and structure are relatively small, while after 70 years, these alterations are accelerated considerably. Factors responsible for the "aging" of skeletal muscles are complex and include intrinsic biochemical changes in muscle metabolism, changes in the distribution and size of muscle fibers, and a general loss of muscle mass. In addition, other factors like the control of muscle contraction by the motor neural system and the influence of external conditions such as exercise, immobility, nutrition and others may also contribute to the age-related decrease in muscle functions. Studies have shown that with age there is some loss of peripheral motor neurons, reduction in the number of motor units, alterations in the neuromuscular junctions, and selective denervation of Type II muscle fibers. These findings led to the concept of denervation atrophy of skeletal muscles as one of the major mechanisms for muscle degeneration in old age. However, it should be emphasized that the extent of age-related changes varies from muscle to muscle, and some do not seem to be affected by age. For example, it has been shown recently, in animal studies, that weight-bearing muscles are much more susceptible to senescent processes than non-weight-bearing muscles. More work is needed to clarify the contributions of the various factors, especially the role of muscle training in alleviating the symptoms of age-related muscle atrophy.
Misstatements of thermodynamic properties of tetracyanoethylene-aromatic donor molecular compounds (1969)

ADVERTISEMENT RETURN TO ISSUEPREVArticleMisstatements of thermodynamic properties of tetracyanoethylene-aromatic donor molecular compoundsWilliam C. Herndon and Richard D. GoodinCite this: J. Phys. Chem. 1969, 73, 8, 2793–2794Publication Date (Print):August 1, 1969Publication History Published online1 May 2002Published inissue 1 August 1969https://pubs.acs.org/doi/10.1021/j100842a064https://doi.org/10.1021/j100842a064research-articleACS PublicationsRequest reuse permissionsArticle Views21Altmetric-Citations1LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts
Diffusion Changes During Human Brain Maturation (2000)

Introduction During human brain maturation various anatomical changes occur. The water content decreases, number of cells and number of neuronal connections change, the myelination continues (1). It would be important to quantify these changes so that developmentally delayed infants can be diagnosed early. Since MR has a very good tissue contrast, it has been used extensively to monitor myelination changes in developing brain (Z-S). Also, recently MR diffusion tensor imaging is used in newborns to assess white matter, quantitatively (6). Diffusion of water in human brain is sensitive to the water content and tissue microstructure. So by monitoring the diffusion changes in the developing human brain microscopic information can be obtained using macroscopic imaging means. In this preliminary work, we report age dependency of diffusion changes in normal patients.
Heat Transfer and Simulated Sterilization of Particulate Solids in a Continuously Flowing System (1989)

ABSTRACT The heat transfer coefficients (h) between a cube and water were 239 and 303 W/m 2 K at 0 and 0.86 cm/s relative velocity. In 35% sucrose and 0 cm/sec, h was 146 W/m 2 K. A model for heat lethality in cubes during continuous sterilization which used finite difference equations for heat conduction and above values of h, revealed that hold times for 6D inactivation of PA 3679 (F 0 = 7.2 min) in an isothermal fluid at 132.2°C were 1.78 and 5.2 min for 1 and 2 cm cubes when h was 303 W/m 2 K and 1.23 and 4.13 min when h was 2500 or higher. When h was 239 W/m 2 K, hold times were 2.36 and 6.02 min for 1 and 2 cm cubes. When fluid entered the hold tube at 132.2°C and particle to fluid ratio was 0.56, fluid‐particle heat exchange increased hold time to 12.2 and 119 min for 1 and 2 cm cubes.
Feasibility and applications of programmed speed control at rotating ring-disk electrodes (1972)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFeasibility and applications of programmed speed control at rotating ring-disk electrodesBarry. Miller, Maria I. Bellavance, and Stanley. BruckensteinCite this: Anal. Chem. 1972, 44, 12, 1983–1992Publication Date (Print):October 1, 1972Publication History Published online1 May 2002Published inissue 1 October 1972https://pubs.acs.org/doi/10.1021/ac60320a010https://doi.org/10.1021/ac60320a010research-articleACS PublicationsRequest reuse permissionsArticle Views95Altmetric-Citations32LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Coronary Computed Tomography Angiography in Diagnosing Obstructive Coronary Artery Disease in Patients with Advanced Chronic Kidney Disease: A Systematic Review and Meta-Analysis (2020)

Based on limited data, CCTA appears to have comparable sensitivity but lower specificity relative to the non-kidney disease population.
Internal charge transfer in proteins to the Schiff bases of their lysine side chains (1978)

Stereochemical investigations carried out with the aid of molecular models show that the Schiff bases formed between methylglyoxal and the primary amino groups of the lysine side chains of proteins can bend back in such a way to the N atoms of the peptide groups that a charge transfer can occur between these groups and the oxygen atoms of the Schiff bases. Ab initio molecular orbital calculations support this finding.