gebhart/patrepeval huggingface dataset:
The azomethine ylide strategy for β-lactam synthesis. An evaluation of alternative pathways for azomethine ylide generation (2001)

Following the generation of azomethine ylide 3 from the β-lactam-based oxazolidinone 1, a series of alternative entries to this and related 1,3-dipoles have been explored. The first approach is based on the use of monocyclic azetidinones 6–12 and 14 carrying a leaving group at C(4) and an activated (acidic) proton adjacent to the ring nitrogen, structural moieties which are both associated with 1. These monocyclic substrates show no tendency towards azomethine ylide formation, which points towards the ring strain present in 1 as an important prerequisite for azomethine ylide formation. The reactivity associated with the racemic Glaxo betaine 17, the structure of which has now been confirmed by X-ray crystallography, appears to involve an azomethine ylide 19, which is very similar to 3. However, attempts to trap 19 using an intermolecular cycloaddition failed; the intramolecular process involving an enolate as a trapping agent to give oxapenem 18 is more effective. Two novel thia-substituted bicyclic oxazolidinones 22 and 23, as well as the unsubstituted variant 33, have been prepared. In the case of 22 and 23, products derived from an alternative mode of iminium ion formation are observed. This pathway is a consequence of C–S bond cleavage, and this reactivity profile has been evaluated computationally. The data suggest that relief of strain within the four-membered ring—as opposed to 1 in which five-membered ring cleavage leads to an iminium ion—provides a driving force for C–S bond cleavage. As a result, the ability of 22 and 23 to give a synthetically useful azomethine ylide is compromised by the siting of an alternative leaving group adjacent to the azetidinone nitrogen. The unsubstituted bicyclic oxazolidinone 33 is thermally unstable, and no cycloadducts have been characterized from this system. Again, computational studies suggest that both direct and stepwise decarboxylation of 33 are energetically demanding processes.
1,3-Dimethyl-3-acyltriazenes: synthesis and chemistry of a novel class of biological methylating agents (1986)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXT1,3-Dimethyl-3-acyltriazenes: synthesis and chemistry of a novel class of biological methylating agentsRichard H. Smith Jr., Andrew F. Mehl, Anne Hicks, Cheryl L. Denlinger, Lisa Kratz, A. Wesley Andrews, and Christopher J. MichejdaCite this: J. Org. Chem. 1986, 51, 20, 3751–3757Publication Date (Print):October 1, 1986Publication History Published online1 May 2002Published inissue 1 October 1986https://doi.org/10.1021/jo00370a002RIGHTS & PERMISSIONSArticle Views149Altmetric-Citations18LEARN 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 InReddit PDF (971 KB) Get e-Alerts Get e-Alerts
Telemedicine in veterinary practice (2006)

Veterinary surgeons have a long tradition of consulting one another about problem cases and many have unwittingly practised telemedicine when discussing cases by telephone or by sending laboratory reports by telefax. Specific veterinary telemedicine applications have been in use since the early 1980s, but little research has been undertaken in this field. The Pubmed and CAB International databases were searched for the following Boolean logic-linked keywords; veterinary and telemedicine, veterinary and telecare, animal and telemedicine, animal and telecare and veterinary and e-mail and an additional search was made of the worldwide web, using Google Scholar. This returned 25 papers which were reviewed. Of these only 2 report research. Sixteen papers had no references and 1 author was associated with 13 papers. Several themes emerge in the papers reviewed. These include remarks about the use of telemedicine, the benefits that can and are derived from the use of telemedicine, areas of practice in which telemedicine is being used, ethical and legal issues around the practice of telemedicine, image standards required for telemedicine, the equipment that is required for the practice of telemedicine, advice on ways in which digital images can be obtained and educational aspects of telemedicine. These are discussed. Veterinary practice has lagged behind its human counterpart in producing research on the validity and efficacy of telemedicine. This is an important field which requires further research.
Significance of ammonia produced by Helicobacter pylori (1994)

Objective To clarify the effect of ammonia produced by Helicobacter pylori, which has strong urease activity, on the blood ammonia level. Design (1) The quantification of ammonia production by live H. pylori in vitro. (2) The measurement of venous and portal ammonia levels following the instillation of H. pylori into the stomachs of normal or cirrhotic rats. Methods (1) The urease reaction was carried out at 37C with bacteria suspended in phosphate-buffered saline and 400 mmol/l urea solution in acetate buffer, pH 5.0. (2) Bacterial suspensions with or without urea solution were instilled into the stomachs of male normal Wistar rats or into rats in which cirrhosis had been induced by injection of carbon tetrachloride; venous and portal ammonia levels were then measured. Results (1) Ammonia production by 105 CFU/ml of live H. pylori was about 5.88–11.76 mmol/l (0.01–0.02%) at 37C over 120 min. (2) In the normal rats, when 107CFU/ml of H. pylori was instilled into the stomach, the venous ammonia level reached about 120 xmol/l after 120min, and about 210 mUmol/l in the cirrhotic rats. Conclusions These data suggest that the ammonia produced by H. pylori may play a role in the pathogenesis of hyperammonemia if this organism is widely distributed and is present in large numbers in the stomach, particularly in the presence of hepatic cirrhosis.
Frederick Grant Banting, 1891-1941 (1942)

Abstract Frederick Grant Banting was born on 14 November 1891, on a farm near the town of Alliston, Ontario. His father, William Thompson Banting, was of Irish extraction, and his mother, Margaret Grant, of Scottish ancestry. Banting attended the rural school and the high school in Alliston. He had a remarkably robust physique and a most enquiring mind, both of which were to stand him in good stead in later life. He was fond of athletic exercise in his early days, but in later life spent little time in recreations with the exception of drawing and painting. He entered the University of Toronto, Victoria College, in 1912. Banting was not a brilliant medical student but his enquiring mind impressed his instructors and his classmates. There are many stories about the small impromptu investigations which he conducted as a part of his undergraduate course. His studies were interrupted in 1915 when he joined the R.C.A.M.C. as a private. He was later sent back to complete his course in medicine, and he was given his commission in the Medical Corps immediately after his graduation in 1916. He saw service in England and in France, and received the Military Cross for exceptional bravery while attending the wounded under fire. He was wounded at Cambrai and for a time it was thought that he would lose his right arm.
Area Efficient Integrated Gate Drivers Based on High-Voltage Charge Storing (2015)

For area reasons, NMOS transistors are preferred over PMOS for the pull-up path in gate drivers. Bootstrapping has to ensure sufficient NMOS gate overdrive. Especially in high-current gate drivers with large transistors, the bootstrap capacitor is too large for integration. This paper proposes three options of fully integrated bootstrap circuits. The key idea is that the main bootstrap capacitor is supported by a second bootstrap capacitor, which is charged to a higher voltage and ensures high charge allocation when the driver turns on. A capacitor sizing guideline and the overall driver implementation including a suitable charge pump for permanent driver activation is provided. A linear regulator is used for bootstrap supply and it also compensates the voltage drop of the bootstrap diode. Measurements from a testchip in 180 nm high-voltage BiCMOS confirm the benefit of high-voltage charge storing. The fully integrated bootstrap circuit with two stacked 75.8 pF and 18.9 pF capacitors results in an expected voltage dip of lower than 1 V. Both bootstrap capacitors require 70% less area compared to a conventional bootstrap circuit. Besides drivers, the proposed bootstrap can also be directly applied to power stages to achieve fully integrated switched mode power supplies or class-D output stages.
Growth and Organized Development of Cultured Cells. IV. The Behavior of the Nucleus (1960)

Mitra, J., Marion O. Mapes, and F. C. Steward. (Cornell U., Ithaca, New York.) Growth and organized development of cultured cells. IV. The behavior of the nucleus. Amer. Jour. Bot. 47(5) : 357—368. Illus. 1960.–The nuclei and the chromosomes of carrot cells have been examined at various stages throughout the following sequence: (1) growth of a tissue culture from a preformed explant of secondary phloem from the carrot root; (2) growth and multiplication of carrot cells freely suspended in a liquid medium; (3) growth and re-formation of organs (roots) and whole plants (including flowers) from cells in the freely suspended state. The cells of the carrot are normally diploid (2n = 18), the cells which develop in the explant are also diploid, and the cells of the re-formed organs, and even the flowers developed upon plants grown from cells, are also normal and diploid; normal meioses also occur. Nevertheless, the wide range in growth and form of the freely suspended cells is accompanied by a rich diversity of cytological conditions; these include tetraploid and highly polyploid nuclei which divide, haploidy and such chromosomal aberrations as di- and even tri-centric bridges. Two division figures showing chromosome numbers at different levels of ploidy were seen within the confines of one large cell, and, in another, 2 adjacent division figures were observed with chromosome numbers lower than diploid. Small thick-walled, densely protoplasmic cells divide to form bi- and tetra-nucleate conditions, and in a giant cell a highly multinucleate condition has been seen. Despite this, however, all the regenerated roots and plants yet examined are normally diploid. The implications of these events are discussed.
Polyhydric Alcohol Pulping at Atmospheric Pressure: An Effective Method for Organosolv Pulping of Softwoods (1999)

Summary Polyhydric alcohol pulping was developed to separate components of low-quality softwoods that are produced by thinning and improvement cutting as well as to establish a self-supporting pulping system. Propylene glycol (PG) was superior to ethylene glycol (EG) as solvent for polyhydric alcohol pulping at atmospheric pressure. PG pulping of fir, larch and cedar, with sulfuric acid as a catalyst, gave satisfactory pulps with few rejects and a very low level of residual lignin as compared with EG pulping. The PG pulps were readily bleached to approximately Kappa number 1 and 80% brightness by one treatment with sodium chlorite. The yield of bleached pulp from fir was 44.7% based on chips. The bleached pulps had very high α-cellulose content and crystallinity, and their mechanical properties were similar to those of kraft pulp. Therefore, polyhydric alcohol pulping appears to be promising for pulping of softwoods by an organosolv method.
Degradation of PCBs by ferric ion, hydrogen peroxide and UV light (1994)

Abstract A 1-g/L two-phase mixture of the commercial PCB oil Aroclor 1242 in acidified water at 66°C was degraded by a photoassisted Fenton-type reaction consisting of Fe3+, H2O2, and UV light (300-400 nm). Up to 88% PCB removal and 85% dechlorination were obtained, without attempts at optimization. The order of reactivity was di- &gt; tri-&gt; tetra- - – higher chlorinated biphenyls, but the selectivity was weak. Perfluorinated surfactants added to increase PCB solubility or rates of dissolution had a detrimental effect on degradation. Minimal reaction was observed at room temperature.
Detector-based luminous-flux calibration using the Absolute Integrating-Sphere Method (1998)

The Absolute Integrating-Sphere Method was developed and introduced by the NIST for the realization of the luminous-flux unit using an integrating sphere rather than a goniophotometer. The total luminous flux of a lamp inside the sphere is calibrated against the known amount of flux introduced into the sphere from the external source through a calibrated aperture. The key element of this method is the correction for the spatial nonuniformity of the integrating sphere, which has been made possible by a technique using a scanning-beam source. This method is to be applied directly to routine calibration measurements of luminous flux. A new luminous-flux calibration facility with a 2.5 m integrating sphere has been recently completed at the NIST and will allow the calibration of test lamps with no need for luminous-flux standard lamps. Calibrations will be performed based on the illuminance measurement of the external source by standard photometers. This method makes the luminous-flux calibration a detector-based procedure, thereby eliminating the uncertainties associated with the use of standard lamps while achieving lower uncertainties by shortening the calibration chain. The characteristics of the new integrating sphere obtained by computer simulation and measurements are reported.
A randomized controlled trial with 4-month follow-up of adjunctive repetitive transcranial magnetic stimulation of the left prefrontal cortex for depression (2007)

Adjunctive rTMS of the left DLPFC could not be shown to be more effective than sham rTMS for treating depression.
Insulin and Cortisol Promote Leptin Production in Cultured Human Fat Cells (1996)

The aim of this study was to investigate the regulation of leptin expression and production in cultured human adipocytes using the model of in vitro differentiated human adipocytes. Freshly isolated human preadipocytes did not exhibit significant leptin mRNA and protein levels as assessed by reverse transcriptase (RT)-polymerase chain reaction (PCR) and radioimmunoassay (RIA). However, during differentiation induced by a defined adipogenic serum-free medium, cellular leptin mRNA and leptin protein released into the medium increased considerably in accordance with the cellular lipid accumulation. In fully differentiated human fat cells, insulin provoked a dose-dependent rise in leptin protein. Cortisol at a near physiological concentration of 10(-8) mol/l was found to potentiate this insulin effect by almost threefold. Removal of insulin and cortisol, respectively, was followed by a rapid decrease in leptin expression, which was reversible after readdition of the hormones. These results clearly indicate that both insulin and cortisol are potent and possibly physiological regulators of leptin expression in human adipose tissue.
Low-cost motivated rehabilitation system for post-operation exercises (2006)

The incidence of joint fractures is increasing and has become one of the major health problems in developed countries. Our low-cost motivated rehabilitation system enables clinicians to prescribe, demonstrate and monitor patient rehabilitation protocols during and between clinical visits. With its unique biofeedback feature it is useful for continuous patient's motivation. The proposed system can be used in wide spectrum of rehabilitation scenarios by simply downloading appropriate protocols. The hardware and software architecture(communication protocols, power management policies and application-level control) have been tuned to optimize cost,battery autonomy and real-time performance required for this application. The main advantages of the proposed system is home-based rehabilitation, low-cost and good user acceptability.
Long-range plasmons in lossy metal films on photonic crystal surfaces (2009)

A one-dimensional (1D) photonic crystal structure with a terminal palladium layer supporting long-range surface plasmon polariton (LRSPP) waves in any gaseous environment is described. We show that LRSPP propagation may be achieved not only along "good plasmonic" metals such as Ag and Au but also along lossy metals such as Pd, which does not usually support plasmon propagation in the visible spectral range with ordinary Kretschmann excitation. The possibility of the LRSPP propagation along catalytically active metals such as Pd or Pt opens up new perspectives for studying of (photo)chemical surface reactions and offers the potential for more applications in the general area of catalysis, photocatalysis, and plasmon-mediated chemistry. We present experimental results that demonstrate the hydrogen sensitivity of this photonic structure incorporating a catalytically active 8-nm-thick Pd final layer. A 3% hydrogen concentration in nitrogen is detected with a signal-to-noise ratio of approximately 300, with a response time of about 10 s at room temperature.
Stem cell engineering for treatment of heart diseases: Potentials and challenges (2008)

Heart disorders are a major health concern worldwide responsible for millions of deaths every year. Among the many disorders of the heart, myocardial infarction, which can lead to the development of congestive heart failure, arrhythmias, or even death, has the most severe social and economic ramifications. Lack of sufficient available donor hearts for heart transplantation, the only currently viable treatment for heart failure other than medical management options (ACE inhibition, beta blockade, use of AICDs, etc.) that improve the survival of patients with heart failure emphasises the need for alternative therapies. One promising alternative replaces cardiac muscle damaged by myocardial infarction with new contractile cardiomyocytes and vessels obtained through stem cell-based regeneration. We report on the state of the art of recovery of cardiac functions by using stem cell engineering. Current research focuses on (a) inducing stem cells into becoming cardiac cells before or after injection into a host, (b) growing replacement heart tissue in vitro, and (c) stimulating the proliferation of the post-mitotic cardiomyocytes in situ. The most promising treatment option for patients is the engineering of new heart tissue that can be implanted into damaged areas. Engineering of cardiac tissue currently employs the use of co-culture of stem cells with scaffold microenvironments engineered to improve tissue survival and enhance differentiation. Growth of heart tissue in vitro using scaffolds, soluble collagen, and cell sheets has unique advantages. To compensate for the loss of ventricular mass and contractility of the injured cardiomyocytes, different stem cell populations have been extensively studied as potential sources of new cells to ameliorate the injured myocardium and eventually restore cardiac function. Unresolved issues including insufficient cell generation survival, growth, and differentiation have led to mixed results in preclinical and clinical studies. Addressing these limitations should ensure the successful production of replacement heart tissue to benefit cardiac patients.
Bio-Based Hydrogels Prepared by Cross-Linking of Microbial Poly(γ-glutamic acid) with Various Saccharides (2006)

Novel bio-based hydrogels were prepared by cross-linking of microbial poly(gamma-glutamic acid) (PGA) with saccharides such as glucose, maltotriose, and cyclodextrin (CD) in the presence of water-soluble carbodiimide in dimethyl sulfoxide (DMSO) by one-pot synthesis at 25 degrees C for 24 h. The degradation of the gels in alkaline solution (pH 9) at 37 degrees C was also investigated. The PGA gels cross-linked with various neutral saccharides were obtained in relatively high recovery yields by use of a base like 4,4-(dimethylamino)pyridine. The PGA gel cross-linked by glucose showed the highest water absorption of 3000 g/g. The PGA gels cross-linked by CDs showed higher water absorption than those cross-linked by the corresponding linear saccharides. It was revealed that the water absorption of the PGA gel was affected by the cross-linker content and also the structure of cross-linkers as they had an effect on the cross-linking density of the PGA gel. The PGA gels were hydrolyzed under alkaline condition (pH 9) at 37 degrees C. The degradation rate was higher when the cross-linker content of the gel was lower.
Real-time obstacle detection in complex scenarios using dense stereo vision and optical flow (2010)

Mobile robots as well as tomorrows intelligent vehicles acting in complex dynamic environments must be able to detect both static and moving obstacles. In intersections or crowded urban areas this task proves to be highly demanding. Stereo vision has been extensively used for this task, as it provides a large amount of data. Since it does not reveal any motion information, static and dynamic objects immediately next to each other, or closely positioned obstacles moving in different directions are often merged into a single obstacle. In this paper we address these problems through a powerful fusion between 3D position information delivered by the stereo sensor and 3D motion information, derived from optical flow, in a depth-adaptive occupancy grid. The proposed model is presented and then applied for determining obstacle localization, orientation and speed.
Generalized d-sequences and their applications to CDMA systems (2003)

Code Division Multiple Access (CDMA), a form of spread spectrum communications is used widely in cellular telephony. CDMA systems employ Walsh-Hadamard orthogonal codes, jointly with Pseudo-Noise (PN) sequences, Gold sequences and Kasami sequences to achieve spreading. This thesis investigates properties of generalized d-sequences and their applications as spreading sequences in CDMA systems. The correlation properties of these sequences are studied. The autocorrelation function of these sequences is not exactly two-valued but the cross correlation values are zero for certain class of these sequences. The zero cross correlation property can be useful in solving the near-far problem in CDMA communication systems, thus obviating the need for power control. The performance of these sequences is analyzed and their application to CDMA systems is investigated.