gebhart/patrepeval huggingface dataset:
Synthesis of Potential Anticancer Agents. XIX. 2-Substituted N<sup>6</sup>-Alkyladenines (1959)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of Potential Anticancer Agents. XIX. 2-Substituted N6-AlkyladeninesJohn A. Montgomery, Lee B. Holum, and Thomas P. JohnstonCite this: J. Am. Chem. Soc. 1959, 81, 15, 3963–3967Publication Date (Print):August 1, 1959Publication History Published online1 May 2002Published inissue 1 August 1959https://pubs.acs.org/doi/10.1021/ja01524a037https://doi.org/10.1021/ja01524a037research-articleACS PublicationsRequest reuse permissionsArticle Views102Altmetric-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 InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Studies on the chemical constituents of rutaceous plants. L. Development of a versatile method for the synthesis of antitumor-active benzo(c)phenanthridine alkaloids. 2. Preparation of 2-aryl-1-tetralone derivatives. (1983)

The synthetic pathway from 2, 4-bisaryl-4-oxobutyramide (3) to 2-aryl-1-tetralone (4), which is the key intermediate in the Robinson synthesis of antitumor-active benzo [c] phenanthridine alkaloids was improved. Treatment of the model keto-amide (3a) under the reported basic conditions gave a γ-keto-α, β-unsaturated acid (9) and degradation products. Reduction of the 2, 4-bisaryl-4-oxobutyramide (3) with sodium borohydride gave 2, 4-bisaryl-4-hydroxybutyramide (16), which could easily be hydrogenolyzed to give 2, 4-bisarylbutyramide (15). However, this transformation also tended to give a γ-lactam derivative (17), unfortunately. We succeeded in the direct hydrogenolysis of the 2, 4-bisaryl-4-oxobutyramide (3) to the 2, 4-bisarylbutyramide (15), which could be hydrolyzed to the corresponding acid (5) without difficulty. The direct hydrolysis of the 2, 4-bisaryl-4-oxobutyronitrile (2) to the 2, 4-bisaryl-4-oxobutyric acid (6) as reported by Cheng et al. was also examined. Ten 2-aryl-1-tetralones (4) required as starting materials for syntheses of various benzo [c] phenanthridine alkaloids were prepared.
The Paradox of State Power in Africa: Debt Management Policies in Kenya and Zimbabwe (1992)

A central debate in the literature on the state has focused on the state's relative strength and weakness in relation to society (Skocpol 1979; Nordlinger 1981, 1987; Evans, et al., 1985; Carnoy 1984). While this debate initially examined developed states and, more recently, semi-industrialized states in Latin America, increasing attention has shifted to African states. It is here where a paradox has emerged that has generated further questions about state power and state-society relations. Africa is plagued with political instability, coup d'etats, deteriorating economic conditions, and ineffective policy implementation (Sandbrook 1985). The current difficulties in meeting scheduled debt repayment deadlines and the pressure to make significant economic adjustments further illustrate the precarious financial status of many African states. Yet, African societies are well known for their heavily centralized bureaucratic apparatus that consumes a substantial portion of expenditures and capital investments. One indicator of state influence is the steady growth of parastatals in African countries. As they have expanded in number and in function, state power over these firms also has grown. And, in response to rapidly deteriorating economic conditions, many African states have enacted widescale debt management controls on foreign investment, public borrowing, and public sector investment. Scholars, whether conceptualizing this influential social group as an “organizational bourgeoisie” or a “managerial bourgeoisie,” consider African state bureaucracies to have their own power capabilities and defined interests (Markowitz 1977; Sklar 1979).
The last of the Victorian mental hospitals (1996)

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Oligonucleotide Synthesis Using Ionic Liquids as Soluble Supports (2007)

The continuing evolution of the methodology for the solution-phase synthesis of oligonucleotides using soluble ionic tags as handles for easy purification is described. This methodology may provide a more cost efficient route for the large scale synthesis of oligonucleotides.
Costing excitement in leisure betting (1995)

The objective of this paper is to explore the effects of excitement on the nature of betting decisions. As such, it addresses an area of inquiry, the relationship between excitement and leisure, which has received only limited attention in the literature. A distinctive feature of the paper is its use of a large and geographically dispersed sample of real betting decisions made in UK betting offices. Two procedures are employed to test the existence and magnitude of the effects of excitement. Those subgroups of the aggregate population which are most subject to excitement are shown to display significantly inferior decision-making performance, despite apparent informational advantages. Evidence is also presented which suggests that they bet with significantly higher stakes and it is argued that the results support the notion that the consumption of excitement involves a financial penalty.
Sparse network coding with overlapping classes (2009)

This paper presents a novel approach to network coding for distribution of large files. Instead of the usual approach of splitting packets into disjoint classes (also known as generations) we propose the use of overlapping classes. The overlapping allows the decoder to alternate between Gaussian elimination and back substitution, simultaneously boosting the performance and reducing the decoding complexity. Our approach can be seen as a combination of fountain coding and network coding. Simulation results are presented that demonstrate the promise of our approach.
Theoretical Study of Ionization of Air by Intense Laser Pulses (1972)

A detailed theoretical study of cascade ionization of air by rf fields and by laser beams is given. Experimental rate constants for energy loss, ionization, and attachment are used. The Boltzmann equation for the electrons is solved in both classical and quantum form. Provision is made for both single-photon and multiphoton ionization and detachment processes. The latter processes have been incorporated parametrically in our calculations owing to the lack of a quantitative description of multiphoton absorption. Possible anomalies in comparison with available experiments are noted for photons in the 1-2-eV range when the illuminated volume is large.
Die 2.2.2-Trichlor -tert-butyloxycarbonyl -Gruppe als N-Schutzgruppe bei Oligonukleotidsynthesen / The 2,2,2-Trichloro-tert-butoxycarbonyl Group, an N-Protecting Group in Oligonucleotide Synthesis (1981)

Abstract The preparation and properties of N 6 -2,2,2 -trichloro -tert-butoxycarbonyl -adenosine axe described as a model of a new protecting group technique for amino groups in oligo-nucleotide syntheses.
Sumatriptan (GR43175) inhibits cyclic‐AMP accumulation in dog isolated saphenous vein (1990)

Sumatriptan (GR43175) contracts rings of dog isolated saphenous vein by an action at 5-HT1-like receptors. We have now examined the effects of sumatriptan on prostaglandin E2(PGE2)-stimulated adenosine 3':5'-cyclic monophosphate (cyclic AMP) accumulation in this tissue. Sumatriptan and 5-hydroxytryptamine (5-HT) produced a concentration-dependent inhibition of PGE2-stimulated cyclic AMP accumulation (EC50 values of 250 nM and 80 nM respectively), responses that were mimicked by 5-carboxamidotryptamine but not by U-46619 or methoxamine. The response to sumatriptan (1 microM) was antagonised by methiothepin (1 microM), but not by metergoline (0.1 microM), spiperone (1 microM) or ondansetron (GR38032, 1 microM). These results suggest that 5-HT1-like receptors which mediate contraction of the dog isolated saphenous vein are negatively coupled to adenylate cyclase in this preparation.
The neural tube/notochord complex is necessary for vertebral but not limb and body wall striated muscle differentiation (1992)

The aim of this work was to investigate the role played by the axial organs, neural tube and notochord, on the differentiation of muscle cells from the somites in the avian embryo. Two of us have previously shown that neuralectomy and notochordectomy is followed by necrosis of the somites and consecutive absence of vertebrae and of most muscle cells derived from the myotomes while the limbs develop normally with muscles. Here we have focused our attention on muscle cell differentiation by using the 13F4 mAb that recognizes a cytoplasmic antigen specific of all types of muscle cells. We show that differentiation of muscle cells of myotomes can occur in the absence of notochord and neural tube provided that the somites from which they are derived have been in contact with the axial organs for a defined period of time, about 10 hours for the first somites formed at the cervical level, a duration that progressively reduces caudalward (i.e. for thoracic and lumbar somites). Either one or the other of the two axial organs, the neural tube or the notochord can prevent somitic cell death and fulfill the requirements for myotomal muscle cell differentiation. Separation of the neural tube/notochord complex from the somites by a surgical slit on one side of the embryo gave the same results as extirpation of these organs and provided a perfect control on the non-operated side. A striking finding was that limb and body wall muscles, although derived from the somites, differentiated in the absence of the axial organs. However, limb muscles that develop after excision of the neural tube started to degenerate from E10 onward due to lack of innervation. In vitro explantation of somites from different axial levels confirmed and defined precisely the chronology of muscle cell commitment in the myotomes as revealed by the in vivo experiments.
Classification-Based Adaptive Web Scraper (2017)

Web scraping is an important problem in computer science. The problem with the commonly-used position or structure-based web scraping tools is that they need to be manually reconfigured as soon as the structure of the web page changes. In this paper, we try to solve this problem of information extraction for web pages consisting of repetitive blocks. We extract these blocks and their constituent attributes, using a novel classification-based approach. Our approach gives high accuracy when used to extract product-offers from an offer-aggregator website. It is also highly adaptive to the changing structure of a website.
<i>In Vivo</i> Sampling: A Promising Technique for Detecting and Profiling Endogenous Substances in Living Systems (2019)

Endogenous substances, naturally occurring in living organisms, are critical components with physiological and biological functions. Discovery and quantitative measurement of endogenous substances in living biotas are important for food analysis, crop cultivation, and quality assessment. Low or non-invasive in vivo sampling techniques offer the advantages of minimal perturbation to the investigated system and potentially obtain more accurate feedback compared to in vitro sampling. In this perspective, we summarize the up-to-date progress in the development of microdialysis and solid-phase microextraction as valuable tools for in vivo sampling of endogenous substances in food and agriculture chemistry. We discuss their feasibility for on-site and real-time in vivo monitoring and highlight the prospects in searching for highly specific coatings, miniaturized sampling devices, and instruments that well meet the trend for high-efficient and high-throughput analyses.
Wettability of Polyhedral Oligomeric Silsesquioxane Nanostructured Polymer Surfaces (2005)

Abstract Summary: Some model structures of waterborne polyurethane anionomers containing various amounts (ca. 3–20%) of a diol functionalized polyhedral oligomeric silsesquioxane (POSS) nanofiller were prepared. X‐ray diffraction showed the formation of a nanocrystalline structure in all copolymers considered. Static contact angle measurements indicated a significant enhancement of surface hydrophobicity as well as reduction in surface tension components even at the least POSS level (3%). Dynamic contact angle cycles allowed the evaluation of the hysteresis, which was found to be large and kinetically increasing in POSS‐modified samples. Film topography was analyzed by AFM, showing a more pronounced roughness in the nanostructured surface. The AFM image showing a moderate roughness increase. magnified image The AFM image showing a moderate roughness increase.
Effect of resin disinfectants-I3 and -I5 on Giardia muris and Giardia lamblia (1983)

The resin-I5 column developed in our laboratories rendered aqueous suspensions containing up to 5 X 10(4) cysts of Giardia muris or Giardia lamblia per ml incapable of excystation. The inhibition of excystation was effective at both 4 and 25 degrees C. The addition of Na2S2O3 to column eluates containing cysts appeared to partially reverse the disinfectant action, and the reversal was more pronounced at 4 degrees C than at 25 degrees C. In contrast, the rapid removal of cysts from the column eluates by centrifugation and filtration or the use of other reductants, notably cysteine and glutathione, did not similarly reverse the disinfectant properties of the column. Based on these data, we suggest that the disinfecting agent is acquired by the cyst in its passage through the resin column and that either the disinfecting agent or its reaction can be partially and specifically neutralized by Na2S2O3. We hypothesize that the time between disinfectant acquisition and activity is a function of the thickness of the Giardia cyst wall and consequently takes longer at the lower temperature. Nevertheless, resin-I5 appears to inactivate a larger number of cysts in a shorter period of time with lower residual halogen levels than do agents of other published methods.
Inverse Emulsion Polymerization (1962)

In an inverse emulsion polymerization, a hydrophilic monomer, frequently in aqueous solution, is emulsified in a continuous oil phase using a water-in-oil emulsifier and polymerized using either an oil-soluble or water-soluble initiator; the products are viscous latices comprised of submicroscopic, water-swollen, hydrophilic polymer particles colloidally suspended in the continuous oil phase. The average particle sizes of these latices are as small as 0.05 microns. The technique is applicable to a wide variety of hydrophilic monomers and oil media. The inverse emulsion polymerization of sodium p-vinylbenzene sulfonate initiated by both benzoyl peroxide and potassium persulfate was compared to the persulfate-initiated polymerization in aqueous solution. Hypotheses for the mechanism and kinetics of polymerization were developed and used to calculate the various kinetic parameters of this monomer.
Differential redistribution of platelet glycoproteins Ib and IIb-IIIa after plasmin stimulation [published erratum appears in Blood 1991 Jul 15;78(2):545] (1991)

The subcellular localization of the platelet membrane receptors glycoproteins (GP) Ib and IIb/IIIa [corrected] has been studied within resting platelets by a combination of biochemical and cytochemical techniques. While both GPIb and GPIIb/IIIa are localized within the plasma membrane and surface-connected canalicular system (SCCS) membranes, only GPIIb/IIIa is present within the internal face of alpha- granular membranes. Previous studies demonstrated that plasmin can induce platelet stimulation and also decrease ristocetin-induced platelet aggregation; it was suggested that this was because of GPIb degradation by plasmin. In this study, the respective localizations of both GPIb and GPIIb/IIIa were visualized during in vitro plasmin stimulation of platelets. Generally, plasmin induced shape change, pseudopod formation, organelle centralization either with or without alpha-granule release depending on the conditions of stimulation. Plasmin treatment of platelets at 37 degrees C resulted in the disappearance of GPIb from the cell surface and its subsequent redistribution into the channels and vesicles of the SCCS with no significant modification of GPIIb/IIIa remaining on the plasma membrane. Within degranulated platelets, GPIIb/IIIa was expressed on the plasma membrane and within membranes of large vacuoles containing the alpha-granule proteins. GPIb was virtually absent from these structures and mainly restricted to the SCCS. Addition of cytochalasin D inhibited the migration of GPIb to the SCCS. Biochemical measurements confirmed that no important hydrolysis of GPIb had occurred because only very little amounts of glycocalicin were generated during the reaction. In conclusion, in plasmin-treated platelets GPIIb/IIIa is externalized to the plasma membrane while GPIb is internalized into the SCCS. Although previous studies have suggested that plasmin degrades GPIb, the reduction in ristocetin-induced aggregation may be explained by its apparent redistribution within the membranes of the SCCS.
Synthesis of poly(ethylene glycol)‐bound NADP by selective modification at the 6‐amino group of NADP (1985)

The N-1 position of the adenine ring of NADP was selectively alkylated by the reaction of 2',3'-cyclic NADP with 3-propiolactone to yield 2',3'-cyclic 1-(2-carboxyethyl)-NADP (I). Derivative I was converted to a mixture of the isomers of N6-(2-carboxyethyl)-NADP with their phosphate groups at the 2' or 3' position (IIa and IIb) by chemical reduction, alkaline rearrangement and chemical reoxidation. Carbodiimide coupling of the mixture of IIa and IIb to alpha, omega-diaminopoly(ethylene glycol) gave the 2', 3'-cyclic derivative of poly(ethylene glycol)-bound NADP (III), which was enzymically hydrolyzed to yield poly(ethylene glycol)-bound NADP (PEG-NADP). PEG-NADP has good cofactor activity (16-100% of that of NADP) for NADP-specific and NAD(P)-specific dehydrogenases except isocitrate and glucose dehydrogenases. For NAD-specific enzymes, PEG-NADP has higher cofactor activity than NADP: for horse liver alcohol dehydrogenase, the cofactor activity of PEG-NADP is 40 times that of NADP and 14% of that of NAD. Kinetic studies show that for most of enzymes tested, Km values for PEG-NADP are larger than those for NADP and V values for PEG-NADP are similar to those for NADP. PEG-NADP proved to be applicable in a continuous enzyme reactor, in which reactions of glutamate dehydrogenase and glucose-6-phosphate dehydrogenase were coupled by the recycling of PEG-NADP.
Synthesis and Biological Properties of Fungal Glucosylceramide (2014)

Department of Molecular Genetics and Microbiology, Stony Brook University, United States
A study of D52S hen lysozyme‐G1cNAc oligosaccharide complexes by NMR spectroscopy and electrospray mass spectrometry (1992)

The production of a mutant hen lysozyme is described in which Asp-52, one of the catalytically important residues, is replaced by Ser. The mutant enzyme has very low catalytic activity but NMR studies show that its structure is closely similar to that of the wild-type protein. NMR experiments also show that well defined complexes are formed with GlcNAc4 and GlcNAc6 bound in the active site of the mutant enzyme. These complexes have been examined using electrospray mass spectrometry (ESMS). The most intense peaks arise from the uncomplexed protein indicating that dissociation takes place in the mass spectrometer under the conditions used here. Peaks from minor species corresponding to complexes between the protein and the oligosaccharides are, however, also observed. The possibility that the latter arise from novel covalent enzyme-saccharide complexes is discussed.
A twin-well CMOS process employing high-energy ion implantation (1986)

A twin-well CMOS process has been developed using ion implantation with energies up to 1 MeV. The high-energy ion-implantation steps eliminate the need for extended processing times at high temperatures. As a consequence, this permits an increase in packing density, independent control of critical electrical parameters, and simplified processing. The resulting process includes advantages of recent developments in bulk CMOS: an n-type isolation well in a p-p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> substrate and retrograde wells. This paper discusses the processing steps involved and provides the resulting device characteristics. An interesting application of the process is also presented, which is the realization of a gate array with TTL-compatible input and output buffers.
Visualization of Spatial Sensor Data in the Context of Automotive Environment Perception Systems (2007)

Spatial sensor systems in cars are gaining more and more importance. Such sensor systems are the foundation of future safety systems, such as automatic emergency brakes, as well as for interactive driver assistance systems. We have developed a system that can visualize such spatial sensor data. Two environments are supported: a laboratory setup for off-line experience and a car setup that enables live experience of spatially aligned laser scanner and video data in real traffic. We have used two visualization devices, a video see-through LCD flat panel (TFT) and an optical see-through head-mounted display (HMD) in both setups. For the laboratory setup, a back-projection table has been integrated as well. To present data in correct spatial alignment, we have installed tracking systems in both environments. Visualization schemes for spatial sensor data and for geometric models that outline recognized objects have been developed. We report on our system and discuss experiences from the development and realization phases. The system is not intended to be used as a component of real driver assistance systems. Rather, it can bridge the gap between human machine interface (HMI) designers and sensing engineers during the development phase. Furthermore, it can be both a debugging tool for the realization of environmental perception systems and an experimental platform for the design of presentation schemes for upcoming driver assistance systems.