gebhart/patrepeval huggingface dataset:
A versatile synthetic route to 1,5-dithiocins from <i>o</i>-mercapto aromatic aldehydes (1999)

An earlier procedure for the facile preparation of benzo-fused 1,5-dithiocins 2a-2c from o-mercapto- benzaldehydes has been improved and shown to be capable of extension to the preparation of several naphthalene-derived analogues. The general method also afforded several N-alkylated 1,5-dithiocins 4, 5 by replacing NH 3 with the appropriate primary amine. It was found that N-acylation of the 1,5-dithiocins was successful only with methyl chloroformate. Attempted N-phenylation met with limited success but was shown to be unnecessary since even the less reactive aniline readily undergoes the general reaction of primary amines. When simple α-amino acids, or their methyl esters, were employed as the primary amine in the reaction with o-mercaptobenzaldehyde, the formation of the N-alkylated 1,5-dithiocins 4a, 17a,17b with accompanying loss of -COOH or -COOMe was observed, in preparatively useful yields. A mechanism is proposed for this interesting transformation.Key words: 1,5-dithiocins, α-amino acids, N-acylation, decarboxylation.
In-fiber Bragg-grating temperature sensor system for medical applications (1997)

A novel quasidistributed in-fiber Bragg grating (FBG) temperature sensor system has been developed for temperature proving in vivo in the human body for medical applications, e.g., hyperthermia treatment. This paper provides the operating principle of FBG temperature sensors and then the design of the sensor head. High-resolution detection of the wavelength-shifts induced by temperature changes are achieved using drift-compensated interferometric detection while the return signals from the FBG sensor array are demultiplexed with a simple monochromator which offers crosstalk-free wavelength-division-multiplexing (WDM). A "strain-free" probe is designed by enclosing the FBG sensor array in a protection sleeve. A four FBG sensor system is demonstrated and the experimental results are in good agreement with those obtained by traditional electrical thermocouple sensors. A resolution of 0.1/spl deg/C and an accuracy of /spl plusmn/0.2/spl deg/C over a temperature range of 30-60/spl deg/C have been achieved, which meet established medical requirements.
Hyposensitization with extracts of <i>Dermatophagoides pteronyssinus</i> and house dust (1972)

Summary A clinical trial in thirty young persons with house dust asthma suggested that a house dust extract was more effective than an extract of Dermatophagoides pteronyssinus when used for hyposensitization. The concentration of D. pteronyssinus extract possibly was too dilute for clinical use.
Effect of the age of tobacco leaves on photosynthesis and photorespiration<xref ref-type="fn" rid="fn1"><sup>1</sup></xref> (1973)

Relationships among the activities of enzymes related to photosynthesis and photorespiration, and 14CO2 photosynthetic products were investigated with individual tobacco leaves attached to the stalk from the bottom to the top. P-glycolate phosphatase of the chloroplasts and glycolate oxidase of the peroxisomes had their maximum activities in the 25th leaf from the dicotyledons. Maximum photorespiration was similarly distributed. The highest ratio of serine-14C to glycine-14C in the photosynthesates and maximum glycolate formation were also observed in the 25th leaf. Glutamateglyoxylate aminotransferase, serine hydroxymethyltransferase and glycine decarboxylase were more active in the upper leaves. RuDP carboxylase had nearly constant activity in all leaves, except for the youngest in which activity decreased. Maximum CO2 photosynthesis and enzyme activity for the C4 dicarboxylic acid cycle occurred in the upper, youngest leaf. Distribution of photosynthetic CO2 fixation among the leaves did not coincide with RuDP carboxylase activity. The photosynthetic capacity appeared to be better related to the distribution pattern for enzymes of the C4 dicarboxylic acid pathway, i.e. PEP carboxylase, pyruvate Pi dikinase and 3-PGA phosphatase in the upper leaves. The results suggest that the C4 dicarboxylic acid pathway participates, to some extent, in photosynthesis in young leaves of tobacco, a dicotyledonous plant.
Aperiodic In-Fiber Bragg Gratings for Optical Fiber Dispersion Compensation (1994)

It is well known that aperiodic (chirped) refractive index Bragg gratings can be used for compensating the dispersion of optical fiber waveguides [1]. When used in reflection mode (in contrast to transmission mode), such Bragg gratings exhibit large dispersion. As well, the sign of the dispersion in reflection mode is easily controlled. Together these two characteristics suggest the use of aperiodic Bragg gratings for dispersion compensation in optical fiber systems. Simple theoretical calculations show that a relatively short Bragg grating device can compensate, over a useful bandwidth, for the dispersion of an optical fiber that is tens of kilometers long.
The Serology of Sd^a Effects of Transfusion and Pregnancy (1982)

Pre- and posttransfusion antibody titers were performed on 6 patients with anti-Sd^a transfused with incompatible blood. In 3 of these patients a significant rise in IgG antibody titer was found. The data suggest that in occasional patients the Sda antigen does evoke a secondary immune response. We evaluated 245 pregnant women for the presence of Sd^a and found that 30% were Sd(a-). This incidence was significantly higher than that found in normal blood donors (4%), but was lower than that described in previous reports. We found that 22% of pregnant women in their first trimester were Sd(a-) whereas at term 36% were Sd(a-). These significantly different incidences of antigen positivity suggest decreased antigen expression with progressing pregnancy, as seen in the Lewis system. No difference was found in the incidence of anti-Sd^a between pregnant women, either during their first trimester or at term, and normal donors.
Potential Use of Intravenous Immune Globulin for Group B Streptococcal Infection (1990)

Several lines of evidence suggest that passive immunization as adjunctive therapy for or prevention of group B streptococcal (GBS) sepsis in neonates will require the use of preparations of human intravenous immune globulin (IVIG) that are hyperimmune for protective antibodies to GBS. Results from both in vitro and in vivo experiments utilizing commercially available IVIG preparations suggest that the doses necessary for achieving levels of pathogen-specific antibody capable of promoting efficient opsonization and phagocytosis of GBS may be prohibitive. Several laboratories have reported that standard IVIG preparations contain only modest levels of antibodies to the four capsular polysaccharides of GBS (the protective moieties), are variable in their effect on in vitro opsonophagocytosis by dose and method of preparation, and are significantly less protective in animal models than is IVIG prepared from adults immunized with GBS polysaccharide vaccines. Further, when we gave a single infusion of standard IVIG at a dose of either 500 or 750 mg/kg to 10 premature neonates during the first week of life, opsonophagocytosis of type III GBS by their sera and adult neutrophils was observed only when high levels of specific antibody were achieved, levels only transiently achieved in nonimmune infants. Commercial preparation of human immune globulin hyperimmune for GBS will be required for optimal adjunctive therapy in patients with sepsis due to GBS and for the possible prevention of late-onset infant disease.
Multiscale Modeling of Inflammation-Induced Tumorigenesis Reveals Competing Oncogenic and Oncoprotective Roles for Inflammation (2017)

Chronic inflammation is a serious risk factor for cancer; however, the routes from inflammation to cancer are poorly understood. On the basis of the processes implicated by frequently mutated genes associated with inflammation and cancer in three organs (stomach, colon, and liver) extracted from the Gene Expression Omnibus, The Cancer Genome Atlas, and Gene Ontology databases, we present a multiscale model of the long-term evolutionary dynamics leading from inflammation to tumorigenesis. The model incorporates cross-talk among interactions on several scales, including responses to DNA damage, gene mutation, cell-cycle behavior, population dynamics, inflammation, and metabolism-immune balance. Model simulations revealed two stages of inflammation-induced tumorigenesis: a precancerous state and tumorigenesis. The precancerous state was mainly caused by mutations in the cell proliferation pathway; the transition from the precancerous to tumorigenic states was induced by mutations in pathways associated with apoptosis, differentiation, and metabolism-immune balance. We identified opposing effects of inflammation on tumorigenesis. Mild inflammation removed cells with DNA damage through DNA damage-induced cell death, whereas severe inflammation accelerated accumulation of mutations and hence promoted tumorigenesis. These results provide insight into the evolutionary dynamics of inflammation-induced tumorigenesis and highlight the combinatorial effects of inflammation and metabolism-immune balance. This approach establishes methods for quantifying cancer risk, for the discovery of driver pathways in inflammation-induced tumorigenesis, and has direct relevance for early detection and prevention and development of new treatment regimes. <i>Cancer Res; 77(22); 6429-41. ©2017 AACR</i>.
Endothelial Heme Oxygenase-1 Induction by Hypoxia (2000)

The stress protein heme oxygenase-1 (HO-1) is induced in endothelial cells exposed to nitric oxide (NO)-releasing agents, and this process is finely modulated by thiols (Foresti, R., Clark, J. E., Green, C. J., and Motterlini R. (1997) J. Biol. Chem. 272, 18411-18417). Here, we report that up-regulation of HO-1 in aortic endothelial cells by severe hypoxic conditions (pO(2) </= 2 mm Hg) is preceded by increased inducible NO synthase and NO synthase activity. This effect is accompanied by oxidation of intracellular glutathione and formation of S-nitrosothiols. Incubation of cells with a selective inhibitor of inducible NO synthase (S-(2-aminoethyl)-isothiourea) or a NO scavenger ([2-(4-carboxyphenyl)-4,4,5, 5-tetramethylimidazoline-1-oxyl-3-oxide]) significantly attenuated the increase in heme oxygenase activity caused by reduced oxygen availability. A series of antioxidant agents did not prevent the elevation in heme oxygenase activity by hypoxia; however, the precursor of glutathione synthesis and thiol donor, N-acetylcysteine, completely abolished HO-1 induction. We also found that the hypoxia-mediated increase in endothelial heme oxygenase activity was potentiated by the presence of S-nitrosoglutathione. These results indicate that intracellular interaction of thiols with NO is an important determinant in the mechanism leading to HO-1 induction by reduced oxygen levels. We suggest that in addition to oxidative stress, HO-1 gene expression can be regulated by redox reactions involving NO and S-nitrosothiols (nitrosative stress), emphasizing a versatile role for the heme oxygenase pathway in the cellular adaptation to a variety of stressful conditions.
Ultrathin Palladium Nanomesh for Electrocatalysis (2018)

An ordered mesh of palladium with a thickness of about 3 nm was synthesized by a solution-based oxidative etching. The ultrathin palladium nanomeshes have an interconnected two-dimensional network of densely arrayed, ultrathin quasi-nanoribbons that form ordered open holes. The unique mesoporous structure and high specific surface area make these ultrathin Pd nanomeshes display superior catalytic performance for ethanol electrooxidation (mass activity of 5.40 Am g<sup>-1</sup> and specific activity of 7.09 mA cm<sup>-2</sup> at 0.8 V vs. RHE). Furthermore, the regular mesh structure can be applied to support other noble metals, such as platinum, which exhibits extremely high hydrogen evolution reaction (HER) activity and durability.
Protective Mechanism of the Mexican Bean Weevil against High Levels of α--Amylase Inhibitor in the Common Bean (1996)

Alpha-amylase inhibitor (alpha AI) protects seeds of the common bean (Phaseolus vulgaris) against predation by certain species of bruchids such as the cowpea weevil (Callosobruchus maculatus) and the azuki bean weevil (Callosobruchus chinensis), but not against predation by the bean weevil (Acanthoscelides obtectus) or the Mexican bean weevil (Zabrotes subfasciatus), insects that are common in the Americas. We characterized the interaction of alpha AI-1 present in seeds of the common bean, of a different isoform, alpha AI-2, present in seeds of wild common bean accessions, and of two homologs, alpha AI-Pa present in seeds of the tepary bean (Phaseolus acutifolius) and alpha AI-Pc in seeds of the scarlet runner bean (Phaseolus coccineus), with the midgut extracts of several bruchids. The extract of the Z. subfasciatus larvae rapidly digests and inactivates alpha AI-1 and alpha AI-Pc, but not alpha AI-2 or alpha AI-Pa. The digestion is caused by a serine protease. A single proteolytic cleavage in the beta subunit of alpha AI-1 occurs at the active site of the protein. When degradation is prevented, alpha AI-1 and alpha AI-Pc do not inhibit the alpha-amylase of Z. subfasciatus, although they are effective against the alpha-amylase of C. chinensis. Alpha AI-2 and alpha AI-Pa, on the other hand, do inhibit the alpha-amylase of Z. subfasciatus, suggesting that they are good candidates for genetic engineering to achieve resistance to Z. subfasciatus.
Experimental Investigation of Dimethyl Ether/Polymer Hybrid as an Enhanced Oil Recovery Method (2016)

Abstract Injection of Dimethyl Ether (DME) dissolved in water can enhance the recovery efficiency with respect to water flooding. In this Shell Proprietary Technology, DME partitions from water into the oil; decreases oil viscosity and increases its volume, and mobilizes the trapped oil again. In this work DME-enhanced water flooding is combined with polymer and considered for cases in which a favorable mobility control between water and oil does not exist. In order to reduce the remaining oil, slugs of the mixed solution of DME and polymer was injected into the cores containing oil and then followed by injection of a chase fluid. This recovery method benefits both (a) from the presence of polymer, and the oil viscosity reduction caused by DME dissolution and (b) from oil swelling due to DME dissolution. It appears from experimental data the injectivity of a DME/polymer (DMEP) solution is higher than the injectivity of a polymer solution without DME indicating that presence of DME can reduce the viscosifying effect of the polymer. The main experimental observations are: (1) a higher oil recovery is obtained from continuous DMEP flooding than from continuous DME-brine Flooding, (2) the presence of polymer in the DME slug and in the chase phase reduced the remaining oil after a finite slug injection, (3) a larger DME slug and mobility control of the chase phase can improve the oil recovery after a finite slug injection. In summary, the experiments show that combining polymer and DME improves the ultimate recovery significantly and shortens the duration of oil production.
Influence of the Mixed Propoxy/Ethoxy Spacer Arrangement Order and of the Ionic Head Group Nature on the Adsorption and Aggregation of Extended Surfactants (2010)

Abstract Two families of extended surfactants were prepared with the same head groups (carboxylate, sulfate, disodium phosphate) and different intermediate spacer structures. In one there was an average of 7 propylene oxide groups on the side of the tail and an average of 7 ethylene oxide groups on the side of the head, to produce a sequence of two different polarity segments. In the other case the spacer contained the same average numbers of propylene and ethylene oxide groups but in some homogeneous arrangement. The intermediate spacer structure, without ionic head group and in the cases of the carboxylate and sulfate extended surfactants, had a packing density reduction which is associated to the homogeneously alkoxide arrangement in the spacer. Such an arrangement was found to produce about 20% more surface area at the interface, apparently because it results in some plumpness due to the spacer folding to remain close to the interface. Both the critical micelle concentration and occupied interfacial area of the extended surfactant increased with the ionization of the anionic group associated with the electrostatic repulsion effect.
Proinflammatory cytokine regulation of cyclic AMP‐phosphodiesterase 4 signaling in microglia <i>in vitro</i> and following CNS injury (2012)

Cyclic AMP suppresses immune cell activation and inflammation. The positive feedback loop of proinflammatory cytokine production and immune activation implies that cytokines may not only be regulated by cyclic AMP but also conversely regulate cyclic AMP. This study examined the effects of tumor necrosis factor (TNF)-α and interleukin (IL)-1β on cyclic AMP-phosphodiesterase (PDE) signaling in microglia in vitro and after spinal cord injury (SCI) or traumatic brain injury (TBI). TNF-α or IL-1β stimulation produced a profound reduction (>90%) of cyclic AMP within EOC2 microglia from 30 min that then recovered after IL-1β but remained suppressed with TNF-α through 24 h. Cyclic AMP was also reduced in TNF-α-stimulated primary microglia, albeit to a lesser extent. Accompanying TNF-α-induced cyclic AMP reductions, but not IL-1β, was increased cyclic AMP-PDE activity. The role of PDE4 activity in cyclic AMP reductions was confirmed by using Rolipram. Examination of pde4 mRNA revealed an immediate, persistent increase in pde4b with TNF-α; IL-1β increased all pde4 mRNAs. Immunoblotting for PDE4 showed that both cytokines increased PDE4A1, but only TNF-α increased PDE4B2. Immunocytochemistry revealed PDE4B nuclear translocation with TNF-α but not IL-1β. Acutely after SCI/TBI, where cyclic AMP levels are reduced, PDE4B was localized to activated OX-42(+) microglia; PDE4B was absent in OX-42(+) cells in uninjured spinal cord/cortex or inactive microglia. Immunoblotting showed PDE4B2 up-regulation from 24 h to 1 wk post-SCI, the peak of microglia activation. These studies show that TNF-α and IL-1β differentially affect cyclic AMP-PDE signaling in microglia. Targeting PDE4B2 may be a putative therapeutic direction for reducing microglia activation in CNS injury and neurodegenerative diseases.
Thermal conductivity of graphene nanoribbons under shear deformation: A molecular dynamics simulation (2017)

Tensile strain and compress strain can greatly affect the thermal conductivity of graphene nanoribbons (GNRs). However, the effect of GNRs under shear strain, which is also one of the main strain effect, has not been studied systematically yet. In this work, we employ reverse nonequilibrium molecular dynamics (RNEMD) to the systematical study of the thermal conductivity of GNRs (with model size of 4 nm × 15 nm) under the shear strain. Our studies show that the thermal conductivity of GNRs is not sensitive to the shear strain, and the thermal conductivity decreases only 12-16% before the pristine structure is broken. Furthermore, the phonon frequency and the change of the micro-structure of GNRs, such as band angel and bond length, are analyzed to explore the tendency of thermal conductivity. The results show that the main influence of shear strain is on the in-plane phonon density of states (PDOS), whose G band (higher frequency peaks) moved to the low frequency, thus the thermal conductivity is decreased. The unique thermal properties of GNRs under shear strains suggest their great potentials for graphene nanodevices and great potentials in the thermal managements and thermoelectric applications.
Multi‐template approach to modeling engineered disulfide bonds (2006)

The key issue for disulfide bond engineering is to select the most appropriate location in the protein. By surveying the structure of experimentally engineered disulfide bonds, we found about half of them that have geometry incompatible with any native disulfide bond geometry. To improve the current prediction methods that tend to apply either ideal geometrical or energetical criteria to single three-dimensional structures, we have combined a novel computational protocol with the usage of multiple protein structures to take into account protein backbone flexibility. The multiple structures can be selected from either independently determined crystal structures for identical proteins, models of nuclear magnetic resonance experiments, or crystal structures of homology-related proteins. We have validated our approach by comparing the predictions with known disulfide bonds. The accuracy of prediction for native disulfide bonds reaches 99.6%. In a more stringent test on the reported engineered disulfide bonds, we have obtained a success rate of 93%. Our protocol also determines the oxido-reduction state of a predicted disulfide bond and the corresponding mutational cost. From the energy ranking, the user can easily choose top predicted sites for mutagenesis experiments. Our method provides information about local stability of the engineered disulfide bond surroundings.
Passive compensation scheme suitable for use in the single-mode fibre interferometer (1982)

The feasibility of a passive compensation scheme for the SMFI is investigated using a conventional Mach-Zehnder interferometer. Problems normally associated with active feedback stabilisation are eliminated, resulting in infinite range compensation. Minimum detectable phase sensitivities less than 10−6 rad are achievable at frequencies > 1 kHz with the interferometer working in an unshielded environment.
Single Crystal Growth of Ba(Pb, Bi)O<sub>3</sub> from Molten KCl Solvent (1982)

A flux method using KCl as a solvent is proposed for the growth of Ba(Pb, Bi)O 3 single crystals. The single crystals are obtained from a mixture of polycrystalline BaPb 0.9 Bi 0.1 O 3 and KCl. The Meissner effect results and four-probe electrical resistance measurements indicate that the as-grown crystals are superconducting with a critical onset temperature of 10.2 to 10.8 K.
A new approach to suppress arcing in current interruption (2002)

In an existing circuit breaker, mechanical relay, contactor, or switchgear, almost 100% of the interruption energy is consumed by arcing during a current interruption. A new approach to suppress arc is to convert up to 100% interruption energy into thermal energy with a positive temperature coefficient resistivity (PTC) material. The PTC material could be doped-BaTiO/sub 3/-ceramics, conductive polymer, or metallic PTC element. A computer simulation was conducted to guide a short circuit experiment of a circuit breaker prototype. In the prototype a PTC tungsten wire was connected in parallel with a first pair of contacts but in series with a second pair contacts. During a short circuit interruption in the experiment, the first pair contacts was opened first by an insulating wedge. The arc was suppressed and extinguished quickly around the first pair contacts. The current was then shunted to the tungsten and the second contacts. The tungsten limited the current and dissipated most of the energy. The second contacts finally interrupted the current within the first half cycle. Simulations and tests were completed at single phase circuit levels of 138 V/100 kA and 284 V/100 kA. Results indicate that 80% interruption energy was consumed by the tungsten and only 20% the energy by arcing.
Fast and accurate characterization of fiber Bragg gratings with high spatial and spectral resolution (2004)

The complex reflectivity of fiber Bragg gratings is measured by optical frequency-domain reflectometry. By inverse scattering the complex coupling coefficient is reconstructed. A spatial resolution of 20 nm is achieved, while measurement time is only a few seconds.