gebhart/patrepeval huggingface dataset:
Design of atomic force microscope cantilevers for combined thermomechanical writing and thermal reading in array operation (2002)

In thermomechanical data writing, a resistively-heated atomic force microscope (AFM) cantilever tip forms indentations in a thin polymer film. The same cantilever operates as a thermal proximity sensor to detect the presence of previously written data bits. This paper uses recent progress in thermal analysis of the writing and reading modes to develop new cantilever designs for increased speed, sensitivity, and reduced power consumption in both writing and reading operation. Measurements of cantilever electrical resistance during heating reveals physical limits of cantilever writing and reading, and verifies a finite-difference thermal and electrical simulation of cantilever operation. This work proposes two new cantilever designs that correspond to fabrication technology benchmarks. Simulations predict that the proposed cantilevers have a higher data rate and are more sensitive than the present cantilever. The various cantilever designs offer single-bit writing times of 0.2 /spl mu/s-25 /spl mu/s for driving voltages of 2-25 V. The thermal reading /spl Delta/R/R sensitivity is as high as 4/spl times/10/sup -4/ per vertical nm in near steady-state operation.
Spontaneous polarization effects in wurtzite GaN/AlGaN quantum wells and comparison with experiment (2000)

Electronic and optical properties of wurtzite GaN/AlGaN quantum well (QW) structures with the spontaneous (SP) and piezoelectric (PZ) polarizations are investigated. Although the PZ field in the well is zero where there is no strain if the QW structures are grown on a thick GaN layer, there may still exist a strong field in the well due to the difference between the SP polarizations in the well and barrier regions. It is shown that the transition energies have significant dependence on both the well and the barrier widths and the many-body optical gain is reduced largely due to the SP polarization. In particular, in the case of a QW structure with a large well width, the reduction of the optical gain is dominant due to larger spatial separation between the electron and hole wave functions. These results suggest that a QW structure with a thin well width below 30 Å is desirable for QW lasers. We show that the theoretical transition energies agree very well with the experimental results for several Al compositions and barrier widths. The estimated SP polarization constant for AlN is about −0.040 C/m2, which is smaller than the value (−0.081 C/m2) predicted by previous theory.
Prevalence of Infectious Diseases Among Immigrants Detected in Kuwait (2008)

Background: More than 400,000 immigrants come to Kuwait every year and majority of them from developing countries where infectious diseases are endemic. Our aim was to evaluate the prevalence of six infectious diseases among immigrants and to control the spread of these infections in Kuwait. Methods:. Blood samples from all the immigrants were checked for infectious diseases like, malaria, filaria, HIV, hepatitis B and C and chest x-ray for tuberculosis Results: The total population screened for malaria and filaria were 682,713; for HIV, tuberculosis, hepatitis B and hepatitis C were 1354,151, respectively. Over all incidence of positivity for these diseases were 9,444 (0.5%). About 226 (0.033%) individuals were infected with malaria and the same number with filaria; 301 (0.022%) with HIV; 3,182 (0.23%) with hepatitis B; 3,247 (0.24%) with hepatitis C and 2,262 (0.17%) with tuberculosis. Most of these infectious diseases were found among Indians, Bangladeshis and Pakistanis, respectively. Conclusion: The infected individuals with malaria were treated in Infectious Diseases Hospital, whereas, those with filaria, HIV, hepatitis B and C were sent back to their countries because of the risk of transmission. The dominant species of malaria was Plasmodium vivax followed by Plasmodium falciparum.
Some Properties of the Pyruvate Carboxylase from Pseudomonas fluorescens (1976)

The pyruvate carboxylase of Pseudonomas fluorescens was purified 160-fold from cells grown on glucose at 20 degrees C. The activity of this purified enzyme was not affected by acetyl-coenzyme A or L-aspartate, but was strongly inhibited by ADP, which was competitive towards ATP. Pyruvate gave a broken double reciprocal plot, from which two apparent Km values could be determined, namely 0-08 and 0-21 mM, from the lower and the higher concentration ranges, respectively. The apparent Km for HCO3 at pH 6-9, in the presence of the manganese ATP ion (MnATP2-), was 3-1 mM. The enzyme reaction had an optimum pH value of 7-1 or 9-0 depending on the use of MnATP2- or MgATP2-, respectively, as substrate. Free Mg2+ was an activator at pH values below 9-0. The enzyme was strongly activated by monovalent cations; NH4+ and K+ were the better activators, with apparent Ka values of 0-7 and 1-6 mM, respectively. Partially purified enzymes from cells grown on glucose at 1 or 20 degrees C had the same properties, including the thermal stability. In both cases 50% of the enzyme activity was lost after pre-incubation for 10 min at 46 degrees C. The molecular weight was estimated to be about 300000 daltons by gel filtration on Sephadex G-200. The regulatory properties and molecular weight are thus similar to those determined for the pyruvate carboxylases from Pseudomonas citronellolis and Azotobacter vinelandii.
On-Demand Capture and Release of Organic Droplets Using Surfactant-Doped Polypyrrole Surfaces (2017)

In this paper, we demonstrate the controlled capture and release of dichloromethane (DCM) droplets on dodecylbenzenesulfonate-doped polypyrrole (PPy(DBS)) surfaces in an aqueous environment. The droplets captured on oxidized PPy(DBS) surfaces were released on-demand via a reduction process at ∼0.9 V, with controlled release time and droplet morphology. The release time of an entire droplet (2 ± 1 μL) was proportional to the thickness of the PPy(DBS) coating, increasing from 11.5 to 26.3 s for thicknesses ranging from 0.6 to 5.1 μm. The droplet-release time was also affected by the redox voltages, and among the tested redox voltages, the fastest release was achieved at -0.9/0.1 V. The PPy(DBS) surfaces with larger thicknesses were more durable for the droplet capture and release. The droplets were more rapidly released from PPy(DBS) surfaces with increased surface roughness ratios, such as 6.0 s on a micropillared surface and 10.3 s on a meshed surface, as compared to 14.6 s on the 1.8 μm thick PPy(DBS) surfaces coated on frosted-glass substrates (i.e., with random microstructures). The release of a single droplet was achieved by increasing the underwater oleophobicity of PPy(DBS) surface via O<sub>2</sub> plasma treatment.
Absence of CD43 Fails to Alter T Cell Development and Responsiveness (2001)

Genetic elimination of CD43 has been associated with increased T cell adhesiveness and T cell hyperresponsiveness to mitogens and alloantigens. Therefore, we investigated whether T cell development was perturbed in CD43-deficient mice by breeding CD43(null) mice with male Ag (Hy)-specific TCR-transgenic mice. Neither positive nor negative thymic selection of male Ag-specific T cells were affected by CD43 status. Furthermore, we did not observe a substantial or consistent hyperresponsive pattern in HY-CD43(null) lymph node cells compared with littermate HY-CD43(+/-) lymph node cells upon analysis of in vitro T cell stimulation with male Ag or mitogen. These observations challenged original conclusions associating absence of CD43 with T cell hyperresponsiveness and led us to re-examine this association. Reported phenotypes of CD43(null) mice have been based on mice with a mixed 129xC57BL/6 genetic background. To exclude a possible influence of genetic background differences among individual mice we analyzed CD43(null) littermates that had been back-bred onto the C57BL/6 background for seven to eight generations. We found that CD43(+) and CD43(null) littermates with the C57BL/6 background exhibited no differences in response to mitogen or alloantigen, thereby establishing that T cell hyperresponsiveness is not a general correlate of CD43 absence.
Enhancing Hydrogen Evolution Activity in Water Splitting by Tailoring Li + -Ni(OH) 2 -Pt Interfaces (2011)

Improving the sluggish kinetics for the electrochemical reduction of water to molecular hydrogen in alkaline environments is one key to reducing the high overpotentials and associated energy losses in water-alkali and chlor-alkali electrolyzers. We found that a controlled arrangement of nanometer-scale Ni(OH)(2) clusters on platinum electrode surfaces manifests a factor of 8 activity increase in catalyzing the hydrogen evolution reaction relative to state-of-the-art metal and metal-oxide catalysts. In a bifunctional effect, the edges of the Ni(OH)(2) clusters promoted the dissociation of water and the production of hydrogen intermediates that then adsorbed on the nearby Pt surfaces and recombined into molecular hydrogen. The generation of these hydrogen intermediates could be further enhanced via Li(+)-induced destabilization of the HO-H bond, resulting in a factor of 10 total increase in activity.
Opioids Hyperpolarize β-Endorphin Neurons via μ-Receptor Activation of a Potassium Conductance (1990)

Intracellular recordings were made from hypothalamic arcuate (ARC) neurons with biocytin-filled electrodes under current- and voltage-clamp in slices prepared from ovariectomized guinea pigs which were pretreated with estradiol. Forty-three neurons were identified after linking the intracellular biocytin with streptavidin-FITC and subsequently were examined for beta-endorphin immunoreactivity. Ten of these neurons were immunoreactive for beta-endorphin. beta-Endorphin neurons displayed the following passive membrane properties: RMP:-56 +/- 2 mV; Rin: 439 +/- 66 M omega; tau: 17.5 +/- 2.4 ms; and often fired spontaneously (5.9 +/- 2.2 Hz). These membrane characteristics were not different from identified neurons in the ARC that were not immunoreactive for beta-endorphin. beta-Endorphin neurons exhibited instantaneous inward rectification and time-dependent rectification. The mu-opioid agonist Tyr-D-Ala-Gly-MePhe-Gly-ol (DAGO) decreased spontaneous firing, induced membrane hyperpolarization (12 +/- 2 mV; range 6-22 mV) and decreased the Rin (38 +/- 4%) of the beta-endorphin neurons. These effects of DAGO were blocked by the opioid antagonist naloxone (1 microM) and were not blocked by 1 microM TTX. DAGO-responsive cells were unaffected by either kappa- or delta-receptor opioid agonists. These results indicate that mu-receptors may be autoreceptors on ARC beta-endorphin neurons and that activation of opioid mu-receptors hyperpolarizes beta-endorphin neurons via an increase in K+ conductance. Therefore, opioid peptides may modulate opioid tone through an 'ultra-short loop' feedback control mechanism.
Nuclear transfer and reprogramming (1997)

Nuclear transfer techniques for mammalian embryos have been developed in the last decade. Embryonic nuclei from advanced stages of preimplantation development can be fully reprogrammed and the totipotency is restored when nuclei are transferred into ooplasts. Transfer of nuclei after gene expression from the embryonic genome has started does not appear to restrict the reprogramming of these nuclei. The principles of nuclear transfer are outlined with respect to nuclear remodelling, nucleocytoplasmic interactions and effects of the cell cycle. However, the molecular mechanisms involved in reprogramming donor nuclei remain unknown. It is proposed that epigenetic DNA modification, such as DNA methylation that regulates gene expression, is related to the reprogramming of transplanted nuclei.
T84 cells in culture as a model for enteroaggregative Escherichia coli pathogenesis (1996)

Enteroaggregative Escherichia coli (EAEC) is an important cause of persistent diarrhea in many developing parts of the world, yet the pathogenetic mechanisms of EAEC diarrhea are unknown. Experiments with animal models suggest that EAEC strains damage the intestinal mucosa, and a putative cytotoxin has been described. To characterize the mucosal effects of EAEC, we studied strain 042, which we have shown to cause diarrhea in adult volunteers. Strain 042 was incubated in an in vitro organ culture model with biopsy-derived normal intestinal mucosa from pediatric patients. Strain 042 adhered strongly to samples of jejunal, ileal, and colonic mucosa. In addition, scanning electron microscopic examination of in vitro-infected intestinal biopsies revealed cytotoxic effects marked by exfoliation of mucosal epithelial cells. To develop an in vitro model to study these effects, we incubated 042 with polarized monolayers of the human intestinal epithelial cell lines Caco-2 and T84. Strain 042 adhered strongly to T84 cells but not to Caco-2 cells. T84 cells infected with 042 displayed marked toxic effects, most prominently in areas where bacteria were adhering. The apical membrane of damaged cells exhibited vesiculation and shedding of microvilli. The cytoplasm of affected cells displayed subnuclear vacuolization, and in some cases, nuclei of affected cells became separated from the surrounding cytoplasm. Severely affected cells ruptured, releasing their nuclei. Vacuolated remnant cells were seen throughout the monolayer. Strain 042 was not internalized by T84 cells. We concluded that EAEC strain 042 alters intestinal cell morphology, ultimately leading to cell death. Although the factor(s) required for this effect remains to be elucidated, T84 cells may serve as a valuable model in EAEC pathogenesis studies.
Abi-2, a novel SH3-containing protein interacts with the c-Abl tyrosine kinase and modulates c-Abl transforming activity. (1995)

A protein has been identified that interacts specifically with both the Src homologous 3 (SH3) domain and carboxy-terminal sequences of the c-Abl tyrosine kinase. The cDNA encoding the Abl interactor protein (Abi-2), was isolated from a human lymphocyte library using the yeast two-hybrid system with the Abl SH3 domain as bait. Abi-2 binds to c-Abl in vitro and in vivo. Abi-2 is a novel protein that contains an SH3 domain and proline-rich sequences critical for binding to c-Abl. A basic region in the amino terminus of Abi-2 is homologous to the DNA-binding sequence of homeo-domain proteins. We show that Abi-2 is a substrate for the c-Abl tyrosine kinase. Expression of an Abi-2 mutant protein that lacks sequences required for binding to the Abl SH3 domain but retains binding to the Abl carboxyl terminus activates the transforming capacity of c-Abl. The properties of Abi-2 are consistent with a dual role as regulator and potential effector of the c-Abl protein and suggest that Abi-2 may function as a tumor suppressor in mammalian cells.
Arene oxides of quinoline: epoxidation, N-oxidation and N-methylation reactions (1991)

trans- 5,6,7,8- Diepoxy-5,6,7,8-tetrahydroquinoline 5, 5,6-epoxy-5,6-dihydroquinoline 1-oxide 3, 7,8-epoxy-7,8-dihydroquinoline 1 -oxide 4 and trans- 5,6,7,8 -diepoxy - 5,6,7,8 -tetrahydroquinoline1-oxide 6 have been formed by oxidation of the corresponding arene oxides of quinoline, 5,6-epoxy5,6-dihydroquinoline 1 and 7,8-epoxy-7,8-dihydroquinoline 2. The cis-diepoxides, cis-5,6,7,8-diepoxy-5,6,7,8-tetrahydroquinoline 8 and cis-5,6,7,8-diepoxy-5,6,7,8-tetrahydroquinoline 1-oxide 9 were both obtained by a stepwise synthesis from 7,8-epoxy-7,8-dihydroquinoline 2via the bromohydrin 7. N-Methylation of 5,6-epoxy-5,6-dihydroquinoline 1 and 7,8-epoxy-7,8-dihydroquinoline 2 with methyl trifIuoromethanesulphonate yielded the corresponding N-methylquinolinium arene oxide salts 10 and 11.
Lower respiratory tract lactoferrin and lysozyme arise primarily in the airways and are elevated in association with chronic bronchitis. (1990)

Lactoferrin and lysozyme are proteins found in high concentrations on mucosal surfaces, and they have activities potentially important for the modulation of inflammation. To investigate whether these proteins might contribute to the modulation of the intraluminal airway inflammation associated with chronic bronchitis, lactoferrin and lysozyme were measured in bronchoalveolar lavage (BAL) fluid from 22 subjects with chronic bronchitis and, for comparison, with 10 symptom-free smokers and 16 normal subjects. As a further control, transferrin, a protein structurally homologous to lactoferrin but not known to arise in airway epithelial cells, was also measured. BAL was performed by sequentially instilling and retrieving five 20 ml aliquots of normal saline solution into each of three sites. Analyzing the first aliquots separately from the later four provided fluid that was enriched for airway contents. The concentration of lactoferrin (11.83 +/- 2.86 micrograms/ml vs 0.68 +/- 0.18 micrograms/ml, p less than 0.00001), and lysozyme (6.75 +/- 1.51 micrograms/ml vs 0.52 +/- 0.09 microgram/ml, p less than 0.00001), but not transferrin (3.22 +/- 0.38 microgram/ml vs 2.68 +/- 0.24 micrograms/ml, p = 0.55) was higher in the bronchial sample lavage fluid, suggesting an airway origin for lactoferrin and lysozyme. In subjects with chronic bronchitis, bronchial sample lactoferrin (23.1 +/- 0.5 micrograms/ml) and lysozyme (12.6 +/- 3.5 micrograms/ml) were elevated compared with the normal subjects' lactoferrin (1.9 +/- 0.5 micrograms/ml, p less than 0.0001) and lysozyme (0.77 +/- 0.22 microgram/ml, p less than 0.0001) and the symptom-free smokers' lactoferrin (4.1 +/- 0.8 micrograms/ml, p = 0.005) and lysozyme (4.9 +/- 1.3 micrograms/ml, p = 0.02). Transferrin concentrations did not demonstrate the same relationships. Finally, when the content of bronchial sample lactoferrin and lysozyme were compared with the content of bronchial sample neutrophils, poor correlations were found, which may imply an airway epithelial origin for the two proteins. Thus lactoferrin and lysozyme appear to arise in the lower respiratory tract within the airways and their levels are elevated in association with chronic bronchitis. This suggests that lactoferrin and lysozyme may contribute to the modulation of airway inflammation in chronic bronchitis.
ChemInform Abstract: THE ACETOXYFULVENE SYNTHESIS OF PROSTAGLANDINS. PART 1. SYNTHESIS OF THE COREY ALDEHYDE (1979)

Abstract Die im Schema angegebene Synthese der Titelverbindung (XII) ist für Ansätze im Kilogramm‐Maßstab geeignet und vermeidet die Verwendung gefährlicher Hilfsstoffe.
Sialyl Lewis x Liposomes as a Multivalent Ligand and Inhibitor of E-Selectin Mediated Cellular Adhesion (1996)

A sialyl Lewis x−PEG−DSPE derivative (3) has been prepared using a combined chemical enzymatic approach and incorporated into mPEG−DSPE containing liposomes (PEG, poly(ethylene glycol); mPEG, methoxypoly(ethylene glycol); DSPE, distearoylphosphatidylethanolamine). Several liposomal formulations of 3 were evaluated as inhibitors of E-selectin mediated cellular adhesion in an ELISA assay and were found to be ∼750-fold more potent than the nonliposomal oligosaccharide (2) and greater than 5000-fold more potent than the natural glycotope structure (1). The dramatic increase in potency of the liposomal formulations suggests that oligosaccharide multivalency enhances inhibition of E-selectin adhesion and is an effective approach to the design of more potent selectin cell adhesion inhibitors.
The induction of heat shock proteins as a potential strategy to treat neurodegenerative disorders (2004)

Neurodegenerative diseases, whether acute or chronic, are a tremendous medical problem in the modern world. Therapies are rare and only applied after a vast amount of neurons are lost. Many efforts have been made to develop new strategies to treat these disorders, but so far, there has been no breakthrough. A characteristic shared by some experimental neuroprotective substances is the induction of the heat shock response, in particular the expression of the heat shock proteins Hsp70 and Hsp27. These Hsps protect cells from cell death induced by various noxious stimuli and inhibit various cellular death pathways. Gene therapy, transgenic mice and drugs inducing Hsps in the brain decrease the infarction area after ischemia and protect neurons and nonneuronal cells of the brain. Furthermore, recent data hint toward a protective role of Hsps in chronic neurological diseases. The induction of Hsps as a possible treatment for stroke, Alzheimer's disease and Huntington's disease is discussed.
Including absorption in Gordon’s optical metric (2009)

We show that Gordon's optical metric on a curved spacetime can be generalized to include absorption by allowing the metric to become complex. We demonstrate its use in the realm of geometrical optics by giving three simple examples. We use one of these examples to compute corrected distance-redshift relations for Friedman-Lema\^{\i}tre-Robertson-Walker models in which the cosmic fluid has an associated complex index of refraction that represents grey extinction. We then fit this corrected Hubble curve to the type Ia supernovae data and provide a possible explanation (other than dark energy) of the deviation of these observations from dark matter predictions.
Efficient and transparent dynamic content updates for mobile clients (2006)

We introduce a novel infrastructure supporting automatic updates for dynamic content browsing on resource constrained mobile devices. Currently, the client is forced to continuously poll for updates from potentially different data sources, such as, e-commerce, on-line auctions, stock and weather sites, to stay up to date with potential changes in content. We employ a pair of proxies, located on the mobile client and on a fully-connected edge server, respectively, to minimize the battery consumption caused by wireless data transfers to and from the mobile device. The client specifies her interest in changes to specific parts of pages by highlighting portions of already loaded web pages in her browser. The edge proxy polls the web servers involved, and if relevant changes have occurred, it aggregates the updates as one batch to be sent to the client. The proxy running on the mobile device can pull these updates from the edge proxy, either on-demand or periodically, or can listen for "pushed" updates initiated by the edge proxy. We also use SMS messages to indicate available updates and inform the user of which pages have changed. Our approach is fully implemented using two alternative wireless networking technologies, 802.11 and GPRS, and evaluated on real world dynamic content traces. Our evaluation explores the data transfer savings enabled by our proxy-based infrastructure and the energy consumption when using each of the two networking capabilities. Our results show that our proxy system saves data transfers to and from the mobile device by an order of magnitude and battery consumption by up to a factor of 4.5, compared to the client-initiated continuous polling approach. Our results also show even in the case where users never visit the same page twice, energy consumption is reduced by the pre-fetching and batching or our proxy system.
The Evolving Roles of Vehicular Navigation (1987)

This paper examines existing and potential applications of navigation technology to motor vehicles that operate primarily upon streets and highways. Applications are described and representative systems approaches are outlined in three broad categories; driver information, traffic management, and fleet management. Driver information systems include those that develop and present navigation information in various forms to aid the driver in reaching the desired destination. The traffic management category includes navigation systems that consider real-time traffic conditions in determining optimum routes and, consequently, contribute to the overall improvement of traffic flow. Fleet management applications include automatic vehicle location monitoring systems (which do not necessarily provide navigation information to vehicle drivers) as well as systems which provide routing or step-by-step route guidance. The most comprehensive fleet management applications of vehicular navigation may also include command and control functions.