gebhart/patrepeval huggingface dataset:
N‘-Alkylated Guanidiniocarbonyl Pyrroles:  New Receptors for Amino Acid Recognition in Water (2003)

[reaction: see text] N'-Substituted guanidiniocarbonyl pyrroles 7 were synthesized for the first time by activation of a Boc-protected guanidiniocarbonyl pyrrole 3 with triflic anhydride and subsequent reaction with a primary amine. These guanidinium cations are efficient receptors for the complexation of amino acid carboxylates even in water (K(assoc) > 10(3) M(-1)) as could be shown by UV titration studies.
A discrete population of squamocolumnar junction cells implicated in the pathogenesis of cervical cancer (2012)

Infection by carcinogenic human papillomaviruses (HPV) results in precancers [cervical intraepithelial neoplasia (CIN)] and cancers near the ectoendocervical squamocolumnar (SC) junction of the cervix. However, the specific cells targeted by HPV have not been identified and the cellular origin of cervical cancer remains elusive. In this study, we uncovered a discrete population of SC junctional cells with unique morphology and gene-expression profile. We also demonstrated that the selected junctional biomarkers were expressed by a high percentage of high-grade CIN and cervical cancers associated with carcinogenic HPVs but rarely in ectocervical/transformation zone CINs or those associated with noncarcinogenic HPVs. That the original SC junction immunophenotype was not regenerated at new SC junctions following excision, not induced by expression of viral oncoproteins in foreskin keratinocytes, and not seen in HPV-related precursors of the vagina, vulva, and penis further support the notion that junctional cells are the source of cervical cancer. Taken together, our findings suggest that carcinogenic HPV-related CINs and cervical cancers are linked to a small, discrete cell population that localizes to the SC junction of the cervix, expresses a unique gene expression signature, and is not regenerated after excision. The findings in this study uncover a potential target for cervical cancer prevention, provide insight into the risk assessment of cervical lesions, and establish a model for elucidating the pathway to cervical cancer following carcinogenic HPV infection.
Methylation of RUNX1 by the Nuclear PRMT5/COPR5 Complex Regulates Its Cellular Location in Leukemia Cells, (2011)

Abstract Abstract 3403 RUNX1 is a transcription factor that is required for definitive hematopoietic development, and helps regulate long term hematopoietic stem cell self-renewal, platelet production, and lymphocyte development during adult hematopoiesis. RUNX1 is known to be modified via phosphorylation, acetylation, ubiquitination and methylation, for example on R208 and R210 by PRMT1, which activates its activating function. We continue to investigate how the methylation of RUNX1 by other protein arginine methyl transferases (PRMTs) regulates its function. Loop 9 of the DNA binding domain (the Runt domain) of RUNX1 contains an SGRGK sequence that is also present on the tails of histone H2A and H4. The histone tails of H4 and H2A can be methylated by a purified PRMT5 complex in vitro. An enzymatically active in vitro PRMT5 complex capable of methylating histones and SM proteins requires two subunits: both PRMT5 and MEP50, a WD 40 repeat domain protein. Nevertheless, this purified PRMT5/MEP50 complex cannot methylate the DNA binding domain of the RUNX1 protein in vitro. We show that RUNX1 also can be symmetrically methylated at R142 within the SGRGK motif in vitro by a nuclear PRMT5/MEP50 complex which also contains COPR5. We show after RUNX1 is methylated on R142 within the nucleus of HEL cells, RUNX1 is exported to the cytoplasm in a CRM1 dependent manner, as the export of methylated RUNX1 is blocked by lemptomycin B. CRM1 interacts with PRMT5, supporting that PRMT5 mediated arginine methylation tags protein for nuclear export. Therefore, PRMT5 not only involves in epigenetic regulation by methylation of histones but also it can directly controls the level of transcription factor proteins within the nucleus. Polycytocemia Vera patients who express the Jak2V617F mutation have low PRMT5 activity due to JAK2V617F mediated PRMT5 phosphorylation (Liu et al 2011). How Jak2 signaling affects RUNX1 methylation and RUNX1 localization within the nucleus is still under investigation. By controlling the amount of RUNX1 available within the cell nucleus, PRMT5 may regulate lineage differentiation potential and growth potential of hematopoietic stem and progenitor cells. The nuclear localization of RUNX1 can be changed through post translational modification such as arginine methylation in addition to point mutations and translocations involving RUNX1 found patients with leukemia and pre-leukemic diseases. Disclosures: No relevant conflicts of interest to declare.
A New Simple Semimicro Method for Colorimetric Determination of Urea (1963)

Abstract A new simple and rapid method for quantitative semimicro determination of blood urea is presented. Diacetyl monoxime and thiosemicarbazide form in acid medium with urea a red color complex with a maximum adsorption at 530 mµ stable at room temperature and requiring 0.2 ml. of 1:10 blood filtrate.
Traffic-driven power saving in operational 3G cellular networks (2011)

Base stations (BSes) in the 3G cellular network are not energy proportional with respect to their carried traffic load. Our mea- surements show that 3G traffic exhibits high fluctuations both in time and over space, thus incurring energy waste. In this paper, we propose a profile-based approach to green cellular infrastruc- ture. We profile BS traffic and approximate network-wide energy proportionality using non-load-adaptive BSes. The instrument is to leverage temporal-spatial traffic diversity and node deployment heterogeneity, and power off under-utilized BSes under light traf- fic. Our evaluation on four regional 3G networks shows that this simple scheme yields up to 53% energy savings in a dense large city and 23% in a sparse, mid-sized city.
Antimicrobial Properties of Substituted Salicylaldehydes and Related Compounds (2007)

A systematic survey of the antimicrobial properties of substituted salicylaldehydes and some related aromatic aldehydes is reported. A total of 23 different compounds, each at four different concentrations, were studied using a panel of seven microbes (Aspergillus niger, Bacillus cereus, Candida albicans, Escherichia coli, Pseudomonas aeruginosa, Saccharomyces cerevisiae and Staphylococcus epidermidis) and employing the paper disc agar diffusion method. Several aldehydes, most notably halogenated, nitro-substituted and hydroxylated salicylaldehydes, displayed highly potent activity against the microbes studied, giving inhibitory zones up to 49 mm in diameter (paper disc diameter 6 mm), while unsubstituted benzaldehyde and salicylaldehyde had minimal activity. Further, 4,6-dimethoxysalicylaldehyde had considerable activity against C albicans and slight activity against S. cerevisiae, while displaying minimal activity against bacteria. Also two aromatic dialdehydes had interesting activity. In general, P. aeruginosa was the least sensitive microbe, a result that is in line with observations from a large screening project, in which this microbe was the one against which the least number of active substances was found. Interestingly, the structure-activity relationships of the aldehydes studied were clearly different for different microbes. Many of the aldehydes tested had such high antimicrobial activity that they are noteworthy candidates for practical applications as well as interesting lead compounds for the development of novel antimicrobial drugs and disinfectants. The structure-activity relationships are discussed in detail. For high activity, substituents are required in benzaldehyde as well as in its 2-hydroxy derivative salicylaldehyde. One hydroxy group alone (at the 2-position) is not enough, but further hydroxylation may produce high activity. The effects of substituents are in some cases dramatic. Halogenation, hydroxylation and nitro substitution may produce highly active compounds, but the effects are not easily predicted nor can they be extrapolated from one microbe to another.
Electrochemical studies of the hexaheme nitrite reductase from <i>Desulfovibrio desulfuricans</i> ATCC 27774 (1993)

The electron-transfer kinetics between three different mediators and the hexahemic enzyme nitrite reductase isolated from Desulfovibrio desulfuricans (ATCC 27774) were investigated by cyclic voltammetry and by chronoamperometry. The mediators, methyl viologen, Desulfovibrio vulgaris (Hildenborough) cytochrome c3 and D. desulfuricans (ATCC 27774) cytochrome c3 differ in structure, redox potential and charge. The reduced form of each mediator exchanged electrons with nitrite reductase. Second-order rate constants, k, were calculated on the basis of the theory for a simple catalytic mechanism and the results, obtained by cyclic voltammetry, were compared with those obtained by chronoamperometry. Values for k are in the range 10(6)-10(8) M-1 s-1 and increase in the direction D. desulfuricans cytochrome c3-->D. vulgaris cytochrome c3-->methyl viologen. An explanation is advanced on the basis of electrostatic interactions and relative orientation between the partners involved. Chronoamperometry (computer controlled) offers advantages over cyclic voltammetry in the determination of homogeneous rate constants (faster, more accurate and better reproducibility). Direct, unmediated electrochemical responses of the hexaheme nitrite reductase were also reported.
Experimental Determination of Diffusion and Formation Energies of Thermal Vacancies in Germanium (1966)

Intrinsic germanium semiconductor specimens with various dislocation densities were quenched from high temperatures to introduce vacancies, after purification by the surface oxidation technique. The contamination due to copper atoms diffused into these specimens was below 1×10 13 atoms/c.c.. Annealing curves of exponential decay type were observed for specimens with dislocation densities ( n D ∼5×10 3 ∼10 5 ). The activation energy for diffusion and diffusion are found to be: 1.2∼1.3 eV and D V ( T )=2×exp (-1.2 eV/ k T )cm 2 /sec.. After annealing of quenched-in vacancies, copper atoms were introduced into the specimens by diffusion procedures. By the analysis of precipitating manner of supersaturated copper atoms thus introduced, the formation energy of a vacancy is found to be 1.9 eV. Considering the number of quenched-in vacancies obtained by the quenching experiments, the concentration of quenched-in vacancies is concluded to be: N V ( T )=1.85×10 23 exp (-1.9 eV/ k T )/c.c..
Apatite Coating on Yttria Doped Partially Stabilized Zirconia Plate in the Presence of Water Vapor (1992)

A new method of apatite coating on yttria partially stabilized zirconia plate was studied. Firstly, calcium metaphosphate was heated and fused onto 3mol% yttria partially stabilized zirconia plate to form an interlayer. Then a mixture of calcium metaphosphate and tetracalcium phosphate was applied on the zirconia plate, followed by heating in the presence of water vapor. Apatite and tricalcium phosphate formed on the surface of the zirconia plate by heating at 1100°C while calcium pyrophosphate and tricalcium phosphate but apatite formed above 1200°C. The products of the coated layer were discussed in relation to the reaction at the interface between zirconia plate and coated layer.
ChemInform Abstract: Analysis of Bonding‐Related Gas Enclosure in Micromachined Cavities Sealed by Silicon Wafer Bonding. (1997)

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.
The Implementation of a Secure RTP Transmission Method Based on DTLS (2013)

Neither the Real-time Transport Protocol security (RTP) nor the Secure Real-time Transport Protocol (SRTP) key management mechanisms is adequate, the complexity of SRTP based on Data gram Transport Layer Security (DTLS) is too high to reduce the scope of use, so this paper designs a real-time encrypted transport mechanism, using DTLS to achieve key management and negotiating encryption algorithms. Extend the DTLS, and then achieve encryption of RTP based on the DTLS and packaging transmission. To be compared in the particular case, the method, under certain safety requirements, is better suited for the high efficiency transmission network. The mechanism provides a good foundation for real-time multipath transmission.
Hepatic Progenitor Cells in Hepatocellular Adenomas (2001)

Hepatocellular adenoma is a benign tumor of the liver that has a small but not negligible risk of malignant transformation into hepatocellular carcinoma. In analogy with the established role of oval cells in hepatocarcinogenesis in rodent models, human hepatic progenitor cells may have a function in the development of liver tumors. To investigate this issue, we performed immunohistochemistry on biopsies of 10 consecutively resected hepatocellular adenomas using markers for hepatic progenitor cells. Sections of paraffin-embedded and frozen biopsies were stained using antibodies against cytokeratins 7, 8, 18, and 19, chromogranin-A, OV-6, and neural cell adhesion molecule. Hepatic progenitor cells were observed in five of 10 hepatocellular adenomas. These five tumors also contained cells with an immunohistochemical phenotype intermediate between hepatic progenitor cells and hepatocytes. Hepatic progenitor cells and intermediate hepatocyte-like cells were scattered throughout the tumors with a density that varied from area to area. Ultrastructural examination confirmed the presence of hepatic progenitor cells. Our study shows that hepatic progenitor cells are present in a considerable proportion of hepatocellular adenomas, supporting the hypothesis that human hepatic progenitor cells can play a role in the development of hepatocellular tumors.
No symbol left behind (2012)

Recently, rateless codes have introduced a promising approach to obtaining wireless throughput higher than what is achieved by fixed-rate codes, especially over time-varying channels. Rateless codes like Raptor, Strider, and spinal codes naturally process all the information available at the receiver corresponding to a packet, whether from one or many frame transmissions. However, a profitable deployment of rateless codes in a wireless network requires a link-layer protocol to coordinate between sender and receiver. This protocol needs to determine how much coded data should be sent before the sender pauses for feedback from the receiver. Without such feedback, an open-loop sender would not know when the packet has been decoded, but sending this feedback is not free and consumes a significant fraction of the packet transmission time. This paper develops RateMore, a protocol that learns the probability distribution of the number of symbols required to decode a packet (the decoding CDF), and uses the learned distribution in a dynamic programming strategy to produce an optimal transmission schedule. Our experiments show that RateMore reduces overhead by between 2.6x and 3.9x compared to 802.11-style ARQ and between 2.8x and 5.4x compared to 3GPP-style "Try-after-n" HARQ.
Critical evaluation of Saltzman technique for NOx analysis in the 0-100 pgm range (1972)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCritical evaluation of Saltzman technique for NOx analysis in the 0-100 pgm rangeDavid H. FineCite this: Environ. Sci. Technol. 1972, 6, 4, 348–350Publication Date (Print):April 1, 1972Publication History Published online1 May 2002Published inissue 1 April 1972https://pubs.acs.org/doi/10.1021/es60063a002https://doi.org/10.1021/es60063a002research-articleACS PublicationsRequest reuse permissionsArticle Views80Altmetric-Citations13LEARN 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
Molecules of ruthenium-based olefin metathesis catalysts as two- and three-photon absorbers (2012)

Three ruthenium-based complexes exhibiting catalytic activity in olefin metathesis have been examined for the presence of interesting nonlinear optical (NLO) properties. Measurements were performed by the Z-scan technique using a tunable femtosecond laser system. This initial screening for potential new applications in photonics of complexes representative of a wide family of ruthenium-based olefin metathesis catalysts has found moderately strong two-photon and three-photon absorption properties in relatively simple molecules that may lead to the development of a new class of strong nonlinear absorbers.
Fatigue Resistant Threaded and Coupled Connectors for Deepwater Riser Systems: Design and Performance Evaluation by Analysis and Full Scale Tests (2008)

Threaded and Coupled (T&C) riser connectors with High Strength Steels have been developed for deepwater top tensioned riser (TTR) applications up to 10,000ft Water Depth. These developments have been ongoing for a decade, and the resulting solutions are now becoming the standard in the industry. Due to the stringent fatigue requirements involved, new design and performance evaluation methods were needed and have been built over time. In this article, we will demonstrate how these methods were implemented into the standard development process of T&C connectors, with a focus on finite element analysis (FEA) techniques. This process includes full scale tests programs on resonant fatigue frames, statistical post treatment of the resulting data, and fatigue cracks expertise for failure mechanism analysis. These elements are a key for the evaluation of T&C connectors’ fatigue performance and for the determination of influencing parameters, leading to the proper design optimization possibilities. The application of these methods will be illustrated with actual examples on T&C connectors’ recent developments. Namely, we will describe FEA methodologies, testing methods and results post-treatment techniques. We will show how the connectors’ performance is eventually derived after such analysis and test data accumulation. The reader will see that innovative and effective fatigue enhancement techniques have resulted, along with premium fatigue compliant sealing devices. The experience and expertise gained, together with a continuous improvement process of our methods have made T&C riser connectors a viable solution to meet emerging needs within deepwater industry, including xHP-HT, SCR and flow lines.
The application of multiple model adaptive control to superheated steam temperature (2009)

Considering the characteristics of time delay, large inertia and time-varying in superheated steam temperature system, the internal model control (IMC) method based on multiple models is suggested. Every model of the model family is created by practical tests with different load. Their corresponding internal controllers are designed. The output of the general controllers is gotten by calculating the sum of the product of the output of every sun-controller and its weighted factor. By this way, the adaptive control of the total operating conditions is realized. The simulation results show that the control strategy has better control performance than the conventional internal model control.
Purification and Characterization of Cell-associated Glucosyltransferase Synthesizing Insoluble Glucan from Streptococcus mutans Serotype c (1989)

Streptococcus mutans Ingbritt (serotype c) was shown to have a significant amount of cell-associated glucosyltransferase activity which synthesizes water-insoluble glucan from sucrose. The enzyme was extracted from the washed cells with SDS, renatured with Triton X-100, adsorbed to 1,3-alpha-D-glucan gel, and then eluted with SDS. The enzyme preparation was electrophoretically homogeneous, and the specific activity was 7.3 i.u. (mg protein)-1. The enzyme had an Mr of 158,000 as determined by SDS-PAGE, and was a strongly hydrophilic protein, as judged by its amino acid composition. The enzyme gradually aggregated in the absence of SDS. The enzyme had an optimum pH of 6.5 and a Km value of 16.3 mm for sucrose. Activity was stimulated 1.7-fold by dextran T10, but was not stimulated by high concentrations of ammonium sulphate. Below a sodium phosphate buffer concentration of 50 mm, activity was reduced by 75%. This enzyme synthesized an insoluble D-glucan consisting of 76 mol% 1,3-alpha-linked glucose and 24 mol% 1,6-alpha-linked glucose.
Optically Active Iridium Imidazol-2-ylidene-oxazoline Complexes:  Preparation and Use in Asymmetric Hydrogenation of Arylalkenes (2002)

This work explores the potential of iridium complexes of the N-heterocyclic carbene oxazoline ligands 1 in asymmetric hydrogenations of arylalkenes. The accessible carbene precursors, imidazolium salts 2, and robust iridium complexes 5 facilitated a discovery/optimization approach that featured preparation of a small library of iridium complexes, parallel hydrogenation reactions, and automated analysis. Three of the complexes (5ab, 5ad, and 5dp) and a similar rhodium complex (6ap) were studied by single-crystal X-ray diffraction techniques. This revealed molecular features of 6ap, and presumably the corresponding iridium complex 5ap, that the others do not have. In enantioselective hydrogenations of arylalkenes complex 5ap was the best for many, but not all, substrates. The enantioselectivities and conversions observed were sensitive to minor changes to the catalyst and substrate structure. Ligands with aliphatic N-heterocyclic carbene substituents gave complexes that are inactive, and do not lose the 1,5-cyclooctadiene ligands under the hydrogenation conditions. Experiments to investigate this unexpected observation imply that it is of a steric, rather than an electronic, origin. Temperature and pressure effects on the conversions and enantioselectivities of these reactions had minimal effects for some alkenes, but profound effects for others. In one case, the enantioselectivities obtained at high-pressure/low-temperature conditions were opposite to those obtained under high-temperature/low-pressure conditions (-64% enantiomeric excess versus +89% enantiomeric excess); a transformation from one prevalent mechanism to another is inferred from this. The studies of pressure dependence revealed that many reactions proceeded with high conversions, and optimal enantioselectivities in approximately 2 h when only 1 bar of hydrogen was used. Deuterium-labeling experiments provide evidence for other types of competing mechanisms that lead to D-incorporation at positions that do not correspond to direct addition to the double bond.