gebhart/patrepeval huggingface dataset:
In-Tube Solid-Phase Microextraction Coupled to Capillary LC for Carbamate Analysis in Water Samples (2000)

Recently, the on-line sample preparation technique, intube solid-phase microextraction (SPME), was successfully implemented with a Hewlett-Packard 1100 HPLC system for analysis of carbamates in water samples. This paper describes the coupling of in-tube SPME to capillary LC and explores its utility as a sample preparation method in that format, relative to conventional LC. The Hewlett-Packard HPLC system was upgraded to a capillary LC system using commercially available accessories from LC Packings. The combination of in-tube SPME with a capillary LC system was expected to build on the merits of both in-tube SPME and the capillary LC to generate a sensitive method with an easy, effective, and efficient sample preparation. Due to the relatively large effective injection volume of the in-tube SPME technique (30-45 microL), on-column focusing was employed in order to achieve good chromatographic efficiency. Excellent sensitivity was achieved with very good method precision. For all carbamates studied, the RSD of retention time was between 0.5 and 0.8% under 4 microL/min microgradient conditions. The RSD of peak area counts was between 1.5 and 4.6%. The detection limits for all carbamates studied were less than 0.3 microg/L and, for carbaryl, just 0.02 microg/L (20 ppt). Compared with the conventional in-tube SPME/LC method, the LODs were lowered for carbaryl, propham, methiocarb, promecarb, chlorpropham, and barban, by factors of 24, 45, 42, 81, 62, and 56, respectively. The optimized method was successfully applied to the analysis of carbamates in surface water samples.
[Imidazole nucleosides, III. Nucleosides of 4(5)-aminoimidazole-5(4)-carboxamide (author's transl)]. (1977)

The synthesis and properties of 13 nucleosides derived from 5-aminoimidazole-4-carboxamide and from 4-aminoimidazole-5-carboxamide are described. The isomers were oriented by comparison of their spectra and colour reactions. All compounds were tested for anticancer activity. 4-Amino-1-(alpha-D-arabinopyranosyl)-imidazole-5-carboxamide significantly inhibits the growth of Ehrlich ascites carcinoma (fluid form) in mice.
A conceptual model for computer security risk analysis (2003)

Risk analysis is required by a number of organizations to provide a basis for deciding which safeguards to implement to protect information systems. A variety of risk analysis techniques and tools have been developed. Each technique or tool is based, implicitly or explicitly, on a conceptual model of risk. The high-level conceptual model of disclosure risk for information systems used in the Analysis of Networked Systems Security Risks (ANSSR) prototype is presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
An adaptive high speed wireless transceiver for personal communications (2002)

In personal communications systems, users contend for the resources of frequency and time, with re-use determined by the spatial separation, power allocation, antenna beam patterns, data rate, and the required signal to interference ratio for reliable operation. We describe a highly adaptive transceiver which implements distributed control of power, channel assignments, and antenna weights, to maximize the network throughput. That is, each link is optimized independently, with coupling only via the mutual interference.
SUBSTITUTION CIPHER WITH PSEUDO-RANDOM SHUFFLING: THE DYNAMIC SUBSTITUTION COMBINER (1990)

A cipher mechanism or process which can be viewed as a modified substitution cipher. A translation table is used to replace plaintext symbols with ciphertext symbols; the modification consists of changing the contents of the translation table after each substitution. The dynamic translation table acts to confuse symbol frequency statistics and so frustrate the usual cryptanalytic attacks. The same mechanism can also be viewed as a cryptographic combiner, and can replace the exclusive-OR combining function used in Vernam stream ciphers. The dynamic translation table acts as one-way function to protect the pseudo-random sequence, and consequently helps to prevent cryptanalysis.
Synthesis and Biological Evaluation of Epidithio-, Epitetrathio-, and bis-(Methylthio)diketopiperazines: Synthetic Methodology, Enantioselective Total Synthesis of Epicoccin G, 8,8′-<i>epi</i>-<i>ent</i>-Rostratin B, Gliotoxin, Gliotoxin G, Emethallicin E, and Haematocin and Discovery of New Antiviral and Antimalarial Agents (2012)

An improved sulfenylation method for the preparation of epidithio-, epitetrathio-, and bis-(methylthio)diketopiperazines from diketopiperazines has been developed. Employing NaHMDS and related bases and elemental sulfur or bis[bis(trimethylsilyl)amino]trisulfide (23) in THF, the developed method was applied to the synthesis of a series of natural and designed molecules, including epicoccin G (1), 8,8'-epi-ent-rostratin B (2), gliotoxin (3), gliotoxin G (4), emethallicin E (5), and haematocin (6). Biological screening of selected synthesized compounds led to the discovery of a number of nanomolar antipoliovirus agents (i.e., 46, 2,2'-epi-46, and 61) and several low-micromolar anti- Plasmodium falciparum lead compounds (i.e., 46, 2,2'-epi-46, 58, 61, and 1).
Infrared absorption measurements in the field using LED sources (1992)

Infrared absorption measurements allow the concentrations of specific liquids and gases to be measured. When infrared light-emitting-diode (LED) sources are employed, the infrared monitor can be made compact, low-powered and stable, and therefore suitable for portable applications. The characteristics and advantages of LED technology are discussed, and examples are given of commercial instruments developed to measure moisture in oil and carbon dioxide in air.
Current state of Alzheimer’s fluid biomarkers (2018)

Alzheimer's disease (AD) is a progressive neurodegenerative disease with a complex and heterogeneous pathophysiology. The number of people living with AD is predicted to increase; however, there are no disease-modifying therapies currently available and none have been successful in late-stage clinical trials. Fluid biomarkers measured in cerebrospinal fluid (CSF) or blood hold promise for enabling more effective drug development and establishing a more personalized medicine approach for AD diagnosis and treatment. Biomarkers used in drug development programmes should be qualified for a specific context of use (COU). These COUs include, but are not limited to, subject/patient selection, assessment of disease state and/or prognosis, assessment of mechanism of action, dose optimization, drug response monitoring, efficacy maximization, and toxicity/adverse reactions identification and minimization. The core AD CSF biomarkers Aβ42, t-tau, and p-tau are recognized by research guidelines for their diagnostic utility and are being considered for qualification for subject selection in clinical trials. However, there is a need to better understand their potential for other COUs, as well as identify additional fluid biomarkers reflecting other aspects of AD pathophysiology. Several novel fluid biomarkers have been proposed, but their role in AD pathology and their use as AD biomarkers have yet to be validated. In this review, we summarize some of the pathological mechanisms implicated in the sporadic AD and highlight the data for several established and novel fluid biomarkers (including BACE1, TREM2, YKL-40, IP-10, neurogranin, SNAP-25, synaptotagmin, α-synuclein, TDP-43, ferritin, VILIP-1, and NF-L) associated with each mechanism. We discuss the potential COUs for each biomarker.
Carcinoembryonic antigens are targeted by diverse strains of typable and non‐typable <i>Haemophilus influenzae</i> (2000)

Haemophilus influenzae (Hi), a commensal of the human respiratory mucosa, is an important cause of localized and systemic infections. We show that distinct strains belonging to typable (THi) and non-typable (NTHi) H. influenzae target human carcinoembryonic antigens (the membrane associated CEA family of cell adhesion molecules, are now termed CEACAMs). All strains of H. influenzae biogroup aegyptius (Hi-aeg) and more than 70% of THi and NTHi strains tested specifically recognize CEACAMI-Fc soluble constructs. Furthermore, transfection of Chinese hamster ovary cells with human CEACAM1 cDNA alone was sufficient for promoting Hi interactions with the transfected cells. The majority of the Hi-aeg strains tested interacted with soluble constructs containing only the N-terminal domain. In contrast, several THi and NTHi strains reacted with soluble constructs only when additional extracellular A and B domains of the receptor were present. The use of monoclonal antibodies confirmed that THi and NTHi strains also interact primarily at the N-domain. We used site-directed mutants of CEACAM1 that contained substitutions at surface exposed amino acids and a molecular model of the N-domain to identify the residues involved in interactions with Hi ligands. The studies show that a common region exposed at the CFG face of the molecule is targeted by diverse Hi strains. However, mutation at distinct sites within this area affected the interactions of distinct strains signifying the potential for tissue tropism via this receptor. Analyses of the molecular basis of interaction with human cell lines and purified CEA show that Hi strains, especially those belonging to Hi-aeg, interact with multiple CEACAMs. Because Neisseria meningitidis (Nm) strains are also known to bind at the CFG face of the receptor, we used Nm and Hi strains in co-infection experiments and demonstrate competition between these mucosal pathogens in colonization of target cells via CEACAMs.
Theoretical and experimental investigation of the aeroelastic stability of an advanced bearingless rotor in hover and forward flight (1989)

The aeroelastic stability of a shaft-fixed, 1/8th Froude scaled bearingless rotor was investigated in a series of wind tunnel experiments simulating a wide range of operating conditions. A finite element formulation was used to perform a parallel theoretical analysis, with the goal of determining whether a bearingless rotor system could be made aeroelastically stable without the incorporation of auxilliary dampers. A quick estimate of lag mode damping was provided by a refined moving-block analysis implemented in real time which predicted similar damping values. Model rotor and blade properties were also determined, and these properties were used as inputs for a newly refined bearingless rotor analysis. Predicted results were compared with experimental results in hover and forward flight. Results indicated that soft pitch link stiffness increases pitch-lag coupling and stabilizes lag mode stability in hover and at low advance ratios, but destabilizes at higher advance ratios.
Spectrum sharing for unlicensed bands (2007)

We study a spectrum sharing problem in an unlicensed band where multiple systems coexist and interfere with each other. Due to asymmetries and selfish system behavior, unfair and inefficient situations may arise. We investigate whether efficiency and fairness can be obtained with self-enforcing spectrum sharing rules. These rules have the advantage of not requiring a central authority that verifies compliance to the protocol. Any self-enforcing protocol must correspond to an equilibrium of a game. We first analyze the possible outcomes of a one shot game, and observe that in many cases an inefficient solution results. However, systems often coexist for long periods and a repeated game is more appropriate to model their interaction. In this repeated game the possibility of building reputations and applying punishments allows for a larger set of self-enforcing outcomes. When this set includes the optimal operating point, efficient, fair, and incentive compatible spectrum sharing becomes possible. We present examples that illustrate that in many cases the performance loss due to selfish behavior is small. We also prove that our results are tight and quantify the best achievable performance in a non-cooperative scenario
Sequential parametric optimization of methane production from different sources of forest raw material (2015)

The increase in environmental problems and the shortage of fossil fuels have led to the need for action in the development of sustainable and renewable fuels. Methane is produced through anaerobic digestion of organic materials and is a biofuel with very promising characteristics. The success in using methane as a biofuel has resulted in the operation of several commercial-scale plants and the need to exploit novel materials to be used. Forest biomass can serve as an excellent candidate for use as raw material for anaerobic digestion. During this work, both hardwood and softwood species-which are representative of the forests of Sweden-were used for the production of methane. Initially, when untreated forest materials were used for the anaerobic digestion, the yields obtained were very low, even with the addition of enzymes, reaching a maximum of only 40 mL CH4/g VS when birch was used. When hydrothermal pretreatment was applied, the enzymatic digestibility improved up to 6.7 times relative to that without pretreatment, and the yield of methane reached up to 254 mL CH4/g VS. Then the effect of chemical/enzymatic detoxification was examined, where laccase treatment improved the methane yield from the more harshly pretreated materials while it had no effect on the more mildly pretreated material. Finally, addition of cellulolytic enzymes during the digestion improved the methane yields from spruce and pine, whereas for birch separate saccharification was more beneficial. To achieve high yields in spruce 30 filter paper units (FPU)/g was necessary, whereas 15 FPU/g was enough when pine and birch were used. During this work, the highest methane yields obtained from pine and birch were 179.9 mL CH4/g VS and 304.8 mL CH4/g VS, respectively. For mildly and severely pretreated spruce, the methane yields reached 259.4 mL CH4/g VS and 276.3 mL CH4/g VS, respectively. We have shown that forest material can serve as raw material for efficient production of methane. The initially low yields from the untreated materials were significantly improved by the introduction of a hydrothermal pretreatment. Moreover, enzymatic detoxification was beneficial, but mainly for severely pretreated materials. Finally, enzymatic saccharification increased the methane yields even further.
Reprogramming of TAM toward proimmunogenic type through regulation of MAP kinases using a redox-active copper chelate (2012)

TAMs, present in the tumor microenvironment, play an immunosuppressive role, leading to tumor progression and metastasis. Recently, numerous attempts have been made to switch immunosuppressive TAMs into an immunostimulatory type. Previously, we showed that a copper chelate, viz., copper N-(2-hydroxy acetophenone) glycinate [CuNG], can reprogram TAMs toward the proimmunogenic type to mount an antitumor immune response, but the underlying molecular mechanisms of skewing TAMs toward the proimmunogenic type remain elusive. Herein, we tried to explore the signaling mechanisms responsible for the reprogramming of TAMs. We observed that CuNG-induced ROS generation triggers activation of two MAPKs, i.e., p38MAPK and ERK1/2, and also causes up-regulation of intracellular glutathione. Furthermore, activation of p38 MAPK up-regulated the initial IL-12 production and the activation of ERK1/2 in tandem with GSH, found responsible for IFN-γ production by TAMs. This IFN-γ, in turn, prolonged IL-12 production and down-regulated TGF-β production and thus, plays the decisive role in CuNG-mediated reprogramming of regulatory cytokine production by TAMs. Our work highlights that ROS-mediated activation of MAPKs can convert suppressive macrophages toward the proimmunogenic type. Thus, the present study opens the possibility of targeting TAMs by the use of redox-active compounds for designing a novel, therapeutic strategy against cancer.
Distinct hematopoietic progenitor compartments are delineated by the expression of aldehyde dehydrogenase and CD34 (2005)

A broad range of hematopoietic stem cells and progenitors reside within a fraction of umbilical cord blood (UCB) that exhibits low light scatter properties (SSC(lo)) and high expression of aldehyde dehydrogenase (ALDH(br)). Many SSC(lo) ALDH(br) cells coexpress CD34; however, other cells express either ALDH or CD34. To investigate the developmental potential of these cell subsets, purified ALDH(br) CD34+, ALDH(neg) CD34+, and ALDH(br) CD34(neg) UCB cells were characterized within a variety of in vivo and in vitro assays. Primitive progenitors capable of multilineage development were monitored in long- and short-term repopulation assays performed on nonobese diabetic/severe combined immunodeficiency (NOD/SCID) mice, and in primary and secondary long-term culture assays. These progenitors were highly enriched within the ALDH(br) CD34+ fraction. This cell fraction also enriched short-term myeloid progenitors that were detected in vitro. By comparison, ALDH(neg) CD34+ cells contained few primitive progenitors and had diminished short-term myeloid potential but exhibited enhanced short-term natural killer (NK) cell development in vitro. The ALDH(br) CD34(neg) cells were not efficiently supported by any of the assays used. These studies suggested that in particular the expression of ALDH delineated distinct CD34+ stem cell and progenitor compartments. The differential expression of ALDH may provide a means to explore normal and malignant processes associated with myeloid and lymphoid development.
An integrated experimental environment for distributed systems and networks (2002)

Three experimental environments traditionally support network and distributed systems research: network emulators, network simulators, and live networks. The continued use of multiple approaches highlights both the value and inadequacy of each. Netbed, a descendant of Emulab, provides an experimentation facility that integrates these approaches, allowing researchers to configure and access networks composed of emulated, simulated, and wide-area nodes and links. Netbed's primary goals are ease of use, control, and realism, achieved through consistent use of virtualization and abstraction.By providing operating system-like services, such as resource allocation and scheduling, and by virtualizing heterogeneous resources, Netbed acts as a virtual machine for network experimentation. This paper presents Netbed's overall design and implementation and demonstrates its ability to improve experimental automation and efficiency. These, in turn, lead to new methods of experimentation, including automated parameter-space studies within emulation and straightforward comparisons of simulated, emulated, and wide-area scenarios.
Multiagent Charging of Electric Vehicles Respecting Distribution Transformer Loading and Voltage Limits (2014)

In this paper, a market based multiagent control mechanism that incorporates distribution transformer and voltage constraints for the charging of a fleet of electric vehicles (EVs) is presented. The algorithm solves a utility maximization problem in a distributed way, assigning most charging power to the EVs with the highest need for energy. The algorithm does not rely on an iterative exchange of messages, but finds the optimal solution after the exchange of just one single message. A substation agent is responsible for guaranteeing a safe network operation. It uses the remaining capacity of each of the EV chargers for reactive voltage control. The performance of the algorithm is evaluated on an existing three-phase four-wire distribution grid. Simulation results show that the fleet of EVs can be charged at a minimal increase of costs, without jeopardizing the network.
A useful and versatile procedure for the acylation of nucleosides through an enzymic reaction (1993)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA useful and versatile procedure for the acylation of nucleosides through an enzymic reactionFrancisco Moris and Vicente GotorCite this: J. Org. Chem. 1993, 58, 3, 653–660Publication Date (Print):January 1, 1993Publication History Published online1 May 2002Published inissue 1 January 1993https://pubs.acs.org/doi/10.1021/jo00055a018https://doi.org/10.1021/jo00055a018research-articleACS PublicationsRequest reuse permissionsArticle Views696Altmetric-Citations92LEARN 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
Palaeoproterozoic magnesite: lithological and isotopic evidence for playa/sabkha environments (2001)

Magnesite forms a series of 1‐ to 15‐m‐thick beds within the ≈2·0 Ga (Palaeoproterozoic) Tulomozerskaya Formation, NW Fennoscandian Shield, Russia. Drillcore material together with natural exposures reveal that the 680‐m‐thick formation is composed of a stromatolite–dolomite–‘red bed’ sequence formed in a complex combination of shallow‐marine and non‐marine, evaporitic environments. Dolomite‐collapse breccia, stromatolitic and micritic dolostones and sparry allochemical dolostones are the principal rocks hosting the magnesite beds. All dolomite lithologies are marked by δ 13 C values from +7·1‰ to +11·6‰ (V‐PDB) and δ 18 O ranging from 17·4‰ to 26·3‰ (V‐SMOW). Magnesite occurs in different forms: finely laminated micritic; stromatolitic magnesite; and structureless micritic, crystalline and coarsely crystalline magnesite. All varieties exhibit anomalously high δ 13 C values ranging from +9·0‰ to +11·6‰ and δ 18 O values of 20·0–25·7‰. Laminated and structureless micritic magnesite forms as a secondary phase replacing dolomite during early diagenesis, and replaced dolomite before the major phase of burial. Crystalline and coarsely crystalline magnesite replacing micritic magnesite formed late in the diagenetic/metamorphic history. Magnesite apparently precipitated from sea water‐derived brine, diluted by meteoric fluids. Magnesitization was accomplished under evaporitic conditions (sabkha to playa lake environment) proposed to be similar to the Coorong or Lake Walyungup coastal playa magnesite. Magnesite and host dolostones formed in evaporative and partly restricted environments; consequently, extremely high δ 13 C values reflect a combined contribution from both global and local carbon reservoirs. A 13 C‐rich global carbon reservoir (δ 13 C at around +5‰) is related to the perturbation of the carbon cycle at 2·0 Ga, whereas the local enhancement in 13 C (up to +12‰) is associated with evaporative and restricted environments with high bioproductivity.