gebhart/patrepeval huggingface dataset:
Polyamine Depletion Following Exposure to DL‐α‐Difluoromethylornithine Both In Vivo and In Vitro Initiates Morphological Alterations and Mitochondrial Activation in a Monomorphic Strain of <i>Trypanosoma brucei brucei</i> (1986)

DL-alpha-difluoromethylornithine (DFMO), a specific irreversible inhibitor of ornithine decarboxylase (ODC), rapidly depletes cells of intracellular putrescine. When administered to animals and humans, DFMO cures acute infections of trypanosomiasis. In order to determine if the mechanism of drug action is related to initiation of transformation and biochemical alterations subsequent to polyamine depletion, trypanosome morphology and mitochondrial activation were studied in a monomorphic strain of Trypanosoma brucei brucei. Exposure of trypanosomes to DFMO in vivo in infected rodents or in vitro in culture resulted in a depletion of intracellular putrescine and a cessation of cell division without specific cytotoxicity. These events were followed by a transformation of the long slender bloodstream form to a short stumpy form via an intermediate morphology. Putrescine, the product of the ODC reaction, abrogates this effect. When introduced into SDM-79 medium, the intermediate form is capable of further transformation to an "insect" procyclic trypomastigote whereas the long slender form and short stumpy form are not. Short stumpy forms are incapable of binary fission and have lost their infectivity for the vertebrate host. In addition, the mitochondrial marker enzyme, NAD diaphorase, was found only in the short stumpy and intermediate forms. We hypothesize that the short stumpy phenotype may not be a viable stage in the natural transformation of the trypanosome from its mammalian host to the insect vector.
Product Recirculation and Mixing Studies in a Stagnation Point Reverse Flow Combustor (2007)

Gas turbine combustor design is being driven towards leaner operation to conform to increasingly stringent emissions regulations. The low temperatures reduce NOx emissions but adversely impact the stability of the combustor. A novel combustor design, referred to as a Stagnation-Point Reverse-Flow (SPRF) combustor, was recently developed that is able to operate stably at very lean fuel-air mixtures, over a range of loadings, and with low NOx emissions making it an exciting option for ground power and aircraft gas turbines. Various optical diagnostic techniques are employed to investigate the flame and mixing characteristics of the SPRF combustor operating at atmospheric pressure. These measurements include chemiluminescence imaging, Particle Image Velocimetry (PIV) for velocity fields and Spontaneous Raman Scattering (SRS) for species concentrations. This unique reverse flow design allows hot product gases to mix with and preheat the incoming reactants. The flow reversal also gives rise to a low velocity stagnation zone in the combustor with a high turbulence level facilitating robust flame stabilization over a variety of flow conditions. Product entrainment has been quantified in terms of the recirculation ratio (Kv), defined as the ratio of recirculated mass of product gas to the mass of fuel and air entering the flame zone. Although reactants are found to burn in a highly preheated (1300 K) and turbulent environment due to mixing with hot product gases, the residence times are sufficiently long compared to the ignition timescales such that the reactants do not autoignite. Turbulent flame structure analysis indicates that the flame is primarily in the thin reaction zones regime throughout the combustor. The flame tends to become more flamelet like, however, for increasing distance from the injector. Fuel-air mixing measurements indicate that the fuel is shielded from hot products until it is fully mixed with air, providing almost premixed performance without its associated safety issues. The effect of changing the air injector dimensions on the mixing of fuel and air is also investigated.
Photonic integrated tunable receivers with optical preamplifiers for direct detection (1993)

We propose and demonstrate a photonic integrated tunable receiver which cascades a traveling-wave optical preamplifier, a passive tunable grating-assisted codirectional coupler filter, and a waveguide photodetector. The devices contain three strained InGaAs quantum wells and operate around λ=0.98 μm. The spectral responses have been measured using the broadband spontaneous emission from the integrated amplifier. Optical filters ∼4-nm wide, ∼10-nm apart with grating pitches ranging from 7.4 to 10.6 μm were observed. Wavelength selective photodetection of a channel ∼3-nm wide, tunable over 4.3 nm with a reverse bias is in relatively good agreement with theory.
Progress on W/O Emulsification Technique. (1993)

Two types of new water-in-oil (w/o) type emulsification techniques were described in this review.
Biogenesis and transmembrane topology of the CHIP28 water channel at the endoplasmic reticulum. (1994)

CHIP28 is a 28-kD hydrophobic integral membrane protein that functions as a water channel in erythrocytes and renal tubule epithelial cell membranes. We examined the transmembrane topology of CHIP28 in the ER by engineering a reporter of translocation (derived from bovine prolactin) into nine sequential sites in the CHIP28 coding region. The resulting chimeras were expressed in Xenopus oocytes, and the topology of the reporter with respect to the ER membrane was determined by protease sensitivity. We found that although hydropathy analysis predicted up to seven potential transmembrane regions, CHIP28 spanned the membrane only four times. Two putative transmembrane helices, residues 52-68 and 143-157, reside on the lumenal and cytosolic surfaces of the ER membrane, respectively. Topology derived from these chimeric proteins was supported by cell-free translation of five truncated CHIP28 cDNAs, by N-linked glycosylation at an engineered consensus site in native CHIP28 (residue His69), and by epitope tagging of the CHIP28 amino terminus. Defined protein chimeras were used to identify internal sequences that direct events of CHIP28 topogenesis. A signal sequence located within the first 52 residues initiated nascent chain translocation into the ER lumen. A stop transfer sequence located in the hydrophobic region from residues 90-120 terminated ongoing translocation. A second internal signal sequence, residues 155-186, reinitiated translocation of a COOH-terminal domain (residues 186-210) into the ER lumen. Integration of the nascent chain into the ER membrane occurred after synthesis of 107 residues and required the presence of two membrane-spanning regions. From this data, we propose a structural model for CHIP28 at the ER membrane in which four membrane-spanning alpha-helices form a central aqueous channel through the lipid bilayer and create a pathway for water transport.
Design of a message interworking function for converged IP messaging in Next Generation Networks (2009)

The Internet and the Internet protocol (IP) have influenced the way of communication in the contemporary society. At the same time, the fixed-mobile convergence leads to next generation networks (NGNs) where messaging is looked upon as one of the killer services. Unfortunately, most of the messaging systems are not interoperable and operate in isolation, so users might typically not be able to communicate among different systems. In this paper, we present the architecture of a NGN-based converged messaging enabler to allow transparent and seamless interworking between legacy messaging services as short messaging service (SMS), multimedia messaging service (MMS) and IP-based messaging as XMPP (extensible messaging and presence protocol) and E-Mail. The system provides a generic approach of message interworking that allows easy and straightforward integration of heterogeneous messaging services. A prototype is developed to demonstrate a complex scenario including messaging convergence and the interaction with other telecommunications enablers. We also anticipate the feasibility of the implementation to support multi-media communication.
Identification of a specific binding protein for 1 alpha,25-dihydroxyvitamin D3 in basal-lateral membranes of chick intestinal epithelium and relationship to transcaltachia. (1994)

The steroid hormone 1 alpha,25-dihydroxyvitamin D3 (1 alpha,25-(OH)2D3) elicits biological responses by both genomic and nongenomic pathways. This report describes purification of a receptor for 1 alpha,25-(OH)2D3 (VDR) located in the basal-lateral membrane (BLM) of vitamin D-replete chick intestinal epithelium, which is implicated in the nongenomic stimulation of calcium transport (transcaltachia). The BLM-VDR exhibited saturable binding for [3H]1,25-(OH)2D3 (KD = 0.72 x 10(-9)M, Bmax = 0.24 pmol/mg of protein). A 4500-fold purification of the BLM-VDR receptor was achieved. In addition, saturable binding was observed for [3H]24R,25-(OH)2D3 at physiologically relevant levels (KD = 19 x 10(-9) M, Bmax = 2.4 pmol/mg of protein) to a component apparently distinct from the 1 alpha,25-(OH)2D3 BLM-VDR. A functional correlation between the BLM-VDR and transcaltachia was observed in three experimental situations: (i) vitamin D deficiency, which suppresses transcaltachia, resulted in reduced specific [3H]1 alpha,25-(OH)2D3 binding in the BLM-VDR, relative to corresponding fractions from vitamin D-replete chicks; (ii) the BLM-VDR exhibited down-regulation of specific [3H]1 alpha,25-(OH)2D3 binding following exposure to nonradioactive 1 alpha,25-(OH)2D3; and (iii) the relative potencies of two "6-s-cis" analogs of 1 alpha,25-(OH)2D3 to initiate transcaltachia and their ability to compete with [3H]1 alpha,25-(OH)2D3 for binding to the BLM-VDR were parallel. The combined results support the existence of a plasmalemal 1 alpha,25-(OH)2D3 receptor which is a prime candidate for signal transduction in transcaltachia.
Ligand-independent oligomerization of cell-surface erythropoietin receptor is mediated by the transmembrane domain (2001)

Binding of erythropoietin (Epo) to the Epo receptor (EpoR) is crucial for production of mature red cells. Although it is well established that the Epo-bound EpoR is a dimer, it is not clear whether, in the absence of ligand, the intact EpoR is a monomer or oligomer. Using antibody-mediated immunofluorescence copatching (oligomerizing) of epitope-tagged receptors at the surface of live cells, we show herein that a major fraction of the full-length murine EpoR exists as preformed dimers/oligomers in BOSC cells, which are human embryo kidney 293T-derived cells. This observed oligomerization is specific because, under the same conditions, epitope-tagged EpoR did not oligomerize with several other tagged receptors (thrombopoietin receptor, transforming growth factor beta receptor type II, or prolactin receptor). Strikingly, the EpoR transmembrane (TM) domain but not the extracellular or intracellular domains enabled the prolactin receptor to copatch with EpoR. Preformed EpoR oligomers are not constitutively active and Epo binding was required to induce signaling. In contrast to tyrosine kinase receptors (e.g., insulin receptor), which cannot signal when their TM domain is replaced by the strongly dimerizing TM domain of glycophorin A, the EpoR could tolerate the replacement of its TM domain with that of glycophorin A and retained signaling. We propose a model in which TM domain-induced dimerization maintains unliganded EpoR in an inactive state that can readily be switched to an active state by physiologic levels of Epo.
The Irritant Effects of Pharmaceutically Applied Surfactants (2013)

Abstract Dermal or transdermal medication may lead to irritant contact dermatitis. However, little information is available on the irritant effect of surfactants which are applied in topical formulations. Our aim was to examine the irritant effect of the most frequent compounds in topical products. A murine model was applied. The following compounds were examined: sodium lauryl sulphate (SLS), polyethoxylated (40EO) hydrogenated castor oil and sucrose laurate. SLS led to severe erythema, increase in transepidermal water loss (TEWL) and induced necrosis and accumulation of neutrophylic granulocytes and lymphocytes. Exposure to sucrose laurate resulted in an elevation of TEWL, but histology did not reveal impairment of the skin structure. Application of polyethoxylated (40EO) hydrogenated castor oil was not accompanied by tissue damage. Special attention should be paid to the irritant effect of SLS. Polyethoxylated (40EO) hydrogenated castor oil seems to be a non‐irritant agent and sucrose laurate is also a promising candidate for application in topical preparations.
O/e-MCM packaging with new, patternable dielectric and optical materials (1998)

This paper presents a novel o/e-MCM-L/D concept for fully integrated opto-electronic MCM-packaging aiming at: very low cost, very high interconnect density and high performance. The polymer thin film materials technology allowing the integration of optical waveguides and high density electrical interconnects in just 3 thin film layers is also discussed in terms of chemistry, processes and properties. Very good processability and planarization of the new inorganic-organic photo-polymers, ORMOCERs, (ORganically MOdified CERamics) in combination with a much lower post-curing temperature (120/spl deg/C-170/spl deg/C) than alternative materials (such as polyimide and benzocyclobutene) enables the use of low cost polymer substrates such as FR-4 epoxy. Novel surface mountable waveguide-connectors for passive precision alignment, compatible with standard MT-opto-connectors can be used for coupling light in and out from the o/e-MCM-L/D's. In the demonstrator, laser-arrays (VCSEL's) and photodiode-arrays are flip-chip mounted above UV-excimer laser ablated 45-degree mirrors in the waveguides. Driver-chips and passive components are wirebonded and surface mounted respectively. The modules are also supplied with microvias in the FR4-epoxy-substrate connecting to a ball grid array (BGA) underneath. The need of any extra package for connection to next packaging level is thus eliminated. In conclusion the versatility and the low-cost potential of the presented technologies are emphasized.
A reproducible brain tumour model established from human glioblastoma biopsies (2009)

In vivo passaging of patient GBM biopsies produced tumours representative of the patient tumours, with high take rates and a reproducible disease course. The model provides combinations of angiogenic and invasive phenotypes and represents a good alternative to in vitro propagated cell lines for dissecting mechanisms of brain tumour progression.
Silicon solar cells realized by laser induced diffusion of vacuum-deposited dopants (1981)

A technique for solar cell preparation based on vacuum deposition of thin films of dopants on silicon, followed by irradiation with a high-energy (∼1.5 J/cm2) ruby laser pulse is described. Several dopants like phosphorus, antimony, bismuth, aluminium, gallium, and indium have been investigated. Electrical and Rutherford backscattering measurements indicate that the dopant is dissolved in the silicon and becomes electrically active, as a result of the irradiation. The P-N junctions which are formed are shallow (depth &lt;4000 Å) but heavily doped, since after the laser treatment the solubility of the dopant is generally higher than after a thermal diffusion. Therefore good diode characteristics can be achieved by this simple method, and solar cells up to 14 % efficiency under AM1 (air mass 1) illumination have been realized using dopants like phosphorus, antimony, bismuth, aluminium, or gallium.
Mechanism of Delayed Increases in Kynurenine Pathway Metabolism in Damaged Brain Regions Following Transient Cerebral Ischemia (1993)

Delayed increases in the levels of an endogenous N-methyl-D-aspartate receptor agonist, quinolinic acid (QUIN), have been demonstrated following transient ischemia in the gerbil and were postulated to be secondary to induction of indoleamine-2,3-dioxygenase (IDO) and other enzymes of the L-tryptophan-kynurenine pathway. In the present study, proportional increases in IDO activity and QUIN concentrations were found 4 days after 10 min of cerebral ischemia, with both responses in hippocampus > striatum > cerebral cortex > thalamus. These increases paralleled the severity of local brain injury and inflammation. IDO activity and QUIN concentrations were unchanged in the cerebellum of postischemic gerbils, which is consistent with the preservation of blood flow and resultant absence of pathology in this region. Blood QUIN and L-kynurenine concentrations were not affected by ischemia. Brain tissue QUIN levels at 4 days postischemia exceeded blood concentrations, minimizing a role for breakdown of the blood-brain barrier. Marked increases in the activity of kynureninase, kynurenine 3-hydroxylase, and 3-hydroxyanthranilate-3,4-dioxygenase were also detected in hippocampus but not in cerebellum on day 4 of recirculation. In vivo synthesis of [13C6]QUIN was demonstrated, using mass spectrometry, in hippocampus but not in cerebellum of 4-day postischemic animals 1 h after intracisternal administration of L-[13C6]tryptophan. However, accumulation of QUIN was demonstrated in both cerebellum and hippocampus of control gerbils following an intracisternal injection of 3-hydroxyanthranilic acid, which verifies the availability of precursor to both regions when administered intracisternally. Notably, although IDO activity and QUIN concentrations were unchanged in the cerebellum of ischemic gerbils, both IDO activity and QUIN content were increased in cerebellum to approximately the same degree as in hippocampus, striatum, cerebral cortex, and thalamus 24 h after immune stimulation by systemic pokeweed mitogen administration, demonstrating that the cerebellum can increase IDO activity and QUIN content in response to immune activation. No changes in kynurenic acid concentrations in either hippocampus, cerebellum, or cerebrospinal fluid were observed in the postischemic gerbils compared with controls, in accordance with the unaffected activity of kynurenine aminotransferase activity. Collectively, these results support roles for IDO, kynureninase, kynurenine 3-hydroxylase, and 3-hydroxyanthranilate-3,4-dioxygenase in accelerating the conversion of L-tryptophan and other substrates to QUIN in damaged brain regions following transient cerebral ischemia. Immunocytochemical results demonstrated the presence of macrophage infiltrates in hippocampus and other brain regions that parallel the extent of these biochemical changes.(ABSTRACT TRUNCATED AT 400 WORDS)
Identification of the acidic and basic subunit complexes of glycinin. (1981)

Five complexes consisting of one acidic and one basic subunit that were linked via disulfide bonds were purified from unreduced S-alkylated glycinin. The acidic and basic subunits were identified unambiguously using NH2-terminal sequence analysis, sodium dodecyl sulfate (SDS)-electrophoresis, and analytical isoelectric focusing. The subunit pairings are A1aB2, A1bB1b, A2B1a, A3B4, and F2(2)B3. Polypeptide A4 was not linked to a corresponding basic subunit via a disulfide bond. The study shows that pairing between subunits is nonrandom, which is consistent with evidence that glycinin is synthesized as a Mr = 60,000 precursor that undergoes post-translational modification to form the individual linked subunits.
Multiresolution on-line path planning for small unmanned aerial vehicles (2008)

In this article we propose a new online multiresolution path planning algorithm for a small unmanned air vehicle (UAV) with limited on-board computational resources. The proposed approach assumes that the UAV has detailed information of the environment only in the vicinity of its current position. Information about far away obstacles is also available, albeit with less accuracy. The proposed algorithm uses an integer arithmetic implementation of the fast lifting wavelet transform (FLWT) to get a multiresolution cell decomposition of the environment, whose dimension is commensurate to the onboard computational resources. A topological graph representation of the multiresolution cell decomposition is constructed efficiently, directly from the approximation and detail wavelet coefficients. Hardware-in-the-loop simulation (HILS) results validate the applicability of the algorithm on a small UAV autopilot. Comparisons with the standard D*-lite algorithm are also presented.
Molecular characterization of a β‐type proteasome subunit from <i>Arabidopsis thaliana</i> co‐expressed at a high level with an α‐type proteasome subunit early in the cell cycle (1994)

Proteasomes are the essential components of complexes involved in an extralysosomal energy- and ubiquitin-dependent proteolytic pathway. The first alpha-type proteasome subunit in plants has recently been described. In this work, the sequence of the first beta-type proteasome subunit in plants, isolated from Arabidopsis thaliana cDNA libraries is reported. The mRNA accumulation of both subunits was analysed and compared with those of the ubiquitin and histone mRNAs, in different tissues and during re-initiation of mitotic activity. It is demonstrated that in plants, as in animal cells, the transcripts of both the alpha-type and beta-type proteasome subunits accumulate to high levels during cell proliferation, in parallel with mRNAs coding for a ubiquitin fusion protein and several polyubiquitins, but earlier than those coding for histone H4 whose expression is known to be coupled to DNA synthesis. These results suggest that, as in animal cells, proteasomes may be involved in the progression of the cell cycle.
Genetic Diversity among U.S. Garlic Clones as Detected Using AFLP Methods (2004)

Garlic ( Allium sativum L.) has been clonally propagated for thousands of years because it does not produce seed under standard cultivation conditions. A single garlic accession frequently displays a high degree of phenotypic plasticity that is likely to be dependent upon soil type, moisture, latitude, altitude, and cultural practices. The diversity observed by collectors has occasionally led to the renaming of varieties as they are exchanged among growers and gardeners. As a result, there are numerous garlic varieties available both commercially and within the USDA National Plant Germplasm System (NPGS) that may be identical genotypically, yet have unique cultivar names. To address this possibility, we performed amplified fragment-length polymorphism (AFLP) analysis on a comprehensive selection of 211 Allium sativum and Allium longicuspis accessions from NPGS and commercial sources. We used several statistical approaches to evaluate how these clonal lineages are genetically differentiated and how these patterns of differentiation correspond to recognized phenotypic classifications. These data suggest that while there are extensive duplications within the surveyed accessions, parsimony and distance based analyses reveal substantial diversity that is largely consistent with major phenotypic classes.
Gadolinium diethylenetriaminepentaacetic acid hyaluronan conjugates: preparation, properties and applications (2002)

We have prepared new hyaluronan (HA) gadolinium diethylenetriaminepentaacetic acid (DTPA) conjugates that have potential as tumor specific contrast agents for magnetic resonance imaging. Conjugates were synthesized, starting with a high molecular weight HA or with HA oligomers, by an efficient 2-step procedure involving first, reaction of ethylenediamine with HA carboxylic acid groups and, second, covalent linkage of DTPA to aminated HA. The final polymers were compared in terms of molar masses and DTPA content. Tapping mode atomic force microscopy has been used to examine the morphology of the polymers in aqueous solution.