gebhart/patrepeval huggingface dataset:
High‐pressure freezing causes structural alterations in phospholipid model membranes (1998)

The influence of high-pressure freezing (HPF) on the lipid arrangement in phospholipid model membranes has been investigated. Liposomes consisting of pure dipalmitoyl-phosphatidylcholine (DPPC) and of DPPC mixed with a branched-chain phosphocholine (1,2-di(4-dodecyl-palmitoyl)- sn-glycero-3-phosphocholine) have been analysed by freeze-fracture electron microscopy. The liposomes were frozen either by plunging into liquid propane or by HPF. The characteristic macroripple-phase of the two-component liposome system is drastically changed in its morphology when frozen under high-pressure conditions. The influence of ethanol which acts as pressure transfer medium was ruled out by control experiments. In contrast, no high-pressure alterations of the pure DPPC bilayer membrane have been observed. We assume that the modification of the binary system is due to a pressure-induced relaxation of a stressed and unstable lipid molecule packing configuration. HPF was performed with a newly designed sample holder, for using sandwiched copper platelets with the high-pressure freezing machine Balzers HPM010. The sandwich construction turned out to be superior to the original holder system with regard to freeze-fracturing of fluid samples. By inserting a spacer between the supports samples with a thickness of 20-100 microns can be high-pressure frozen. The sandwich holder is provided with a thermocouple to monitor cooling rates and allows exact sample temperature control. Despite a two-fold mass reduction compared to the original holder no HPF cooling rate improvement has been achieved (4000 degrees Cs-1). We conclude that the cooling process in high-pressure freezing is determined mainly by cryogen velocity.
Effect of Aircraft-Cabin Altitude on Passenger Discomfort (2007)

Ascent from ground level to the conditions of 7000 to 8000 ft lowered oxygen saturation by approximately 4 percentage points. This level of hypoxemia was insufficient to affect the occurrence of acute mountain sickness but did contribute to the increased frequency of reports of discomfort in unacclimatized participants after 3 to 9 hours. (ClinicalTrials.gov number, NCT00326703 [ClinicalTrials.gov].).
Moderate Maternal Alcohol Consumption and Risk of Spontaneous Abortion (1997)

Maternal alcoholism is known to have adverse effects on reproduction and fetal development, but the effects of moderate consumption remain controversial. In a previous case-control study, we found a doubled risk of spontaneous abortion with an average consumption of seven or more drinks per week during the first trimester. To confirm this finding while avoiding potential biases from the case-control design, we examined moderate alcohol consumption in a prospective cohort study of over 5,000 pregnant women. An interview in the first trimester asked about alcohol consumption during the week before interview ("during the first trimester") and before pregnancy. We found an increased risk of spontaneous abortion in women who drank more than three drinks per week during the first trimester, with an adjusted odds ratio (OR) of 2.3 [95% confidence interval (CI) = 1.1-4.5]. The increased risk associated with this moderate alcohol consumption may be higher in first than in second trimester abortions, and it is even higher in the first 10 weeks (OR = 3.8; 95% CI = 1.7-8.7), based on small numbers. Consumption of alcohol before pregnancy was not strongly associated with spontaneous abortion.
The Poly-β-hydroxybutyrate Granule in vivo (1989)

High resolution 13C NMR spectroscopy of live cells has been used to show that poly-beta-hydroxybutyrate (PHB) is predominantly in a mobile state within the storage granules of Alcaligenes eutrophus, Methylobacterium extorquens, and Methylobacterium AM1. Comparison of chemical and NMR analysis of PHB indicates that about 70% of the polymer in A. eutrophus gives sharp observable resonances. Temperature-dependent line widths and relaxation rates together with nuclear Overhauser effect measurements demonstrate that the observed material is effectively a mobile amorphous elastomer that is well above its glass transition temperature. The hydroxyvalerate-hydroxybutyrate copolymer produced by propionate-fed A. eutrophus has virtually the same mobility as the homopolymer. Evidence is presented indicating that water is an integral component of the PHB granule and that this component acts as a plasticizer for the polymer. These observations strongly suggest that the enzyme(s) responsible for PHB biosynthesis and consumption operate only on mobile hydrated material and that the solid granules characteristic of dried cells are partially artifactual. This model is supported by a reinterpretation of previously inexplicable biochemical results.
THE BROOKHAVEN ALTERNATING GRADIENT SYNCHROTRON (1960)

In the synchrotron, nuclear particles are accelerated to energies of several billions of electron volts. Alternating gradient focusing has brought economies to the synchrotron art which make practicable the attainment of energies in the tens of billions of electron volts. The alternating gradient proton synchrotron now nearing completion at the Brookhaven National Laboratory is described. When this machine comes into operation it will yield 30-Bev protons-this energy will be the highest available anywhere in the world. The basic operating principles and parameters of the Brookhaven machine are discussed. (auth)
Design and performance evaluation of scalable TWIN networks (2005)

TWIN has been introduced as an efficient and cost-effective network architecture that can provide multiple types of services without relying on packet switching or TDM switching in the network core. In the basic TWIN, the maximum number of nodes N in a network is limited by the number of available wavelengths W. In this paper, we propose a scalable TWIN whereby a given color may be reused on multiple destinations. Given a physical topology and a traffic matrix, we propose an effective approach that assigns W colors to N destinations and designs a multipoint-to-point tree for each destination to construct a virtual topology. We evaluate the performance of our approach using the single-hop throughput and a multi-hop congestion measure. The performance results reveal both the effectiveness of our approach compared to an upper bound and the robustness of the virtual topology in the face of changing traffic patterns.
Arabinoxylan Content of Commercial Beers (1995)

Fifteen commercial beers representing four product categories were screened for arabinoxylan and β-glucan content. Significant differences (P< 0.05) in the levels both of arabinoxylans and β-glucans were detected between the beers and probably reflect differences in the levels of adjunct utilized. Beer arabinoxylan content ranged from 514 μg/ml in a domestic light beer to 4,211 μg/ml in a German wheat beer. The concentration of β-glucan in all beers was several-fold lower than the corresponding arabinoxylan content. Beer β-glucan content ranged from 0.3 μg/ml to 247.7 μg/ml. Both arabinoxylan and β-glucan content were found to be significantly related to beer viscosity. The results of this study suggest that arabinoxylans may account for up to 10% of the total beer carbohydrate, and further that the role of arabinoxylans in malting, brewing, and beer quality should be more intensely investigated.
Ring-Opening Co- and Terpolymerization of an Alicyclic Oxirane with Carboxylic Acid Anhydrides and CO<sub>2</sub> in the Presence of Chromium Porphyrinato and Salen Catalysts (2011)

Copolymerization of cyclohexene oxide (CHO) with alicyclic anhydrides applying chromium tetraphenylprophyrinato (TPPCrCl, 1) and salophen (SalophenCrCl, 2) catalysts resulted in polyesters or poly(ester-co-ether)s, depending on the nature of the catalyst, presence of a cocatalyst, solvent and type of anhydride. The combination of 1 as catalyst and 4-N,N-dimethylamino-pyridine (DMAP) as cocatalyst in the copolymerization of CHO with succinic anhydride (SA), cyclopropane-1,2-dicarboxylic acid anhydride (CPrA), cyclopentane-1,2-dicarboxylic acid anhydride (CPA) or phthalic anhydride (PA) invariably resulted in a completely alternating topology and therefore a pure polyester. Contrarily, 2 in combination with DMAP did not afford pure polyesters for the copolymerization of CHO with SA or CPrA but did render the alternating topology when CPA or PA was used as anhydride comonomer. Water proved to be an efficient bifunctional CTA affording α,ω-hydroxyl-terminated polyesters without loss of catalytic activity. When CO2 was introduced as additional monomer to CHO and the anhydrides, both 1 and 2 in combination with DMAP as cocatalyst afforded perfect poly(ester-co-carbonate)s. The presence of CO2 effectively prevents the undesirable side reaction of oxirane homopolymerization.
DNA Replication Fork Pause Sites Dependent on Transcription (1996)

Replication fork pause (RFP) sites transiently arresting replication fork movement were mapped to transfer RNA (tRNA) genes of Saccharomyces cerevisiae in vivo. RFP sites are polar, stalling replication forks only when they oppose the direction of tRNA transcription. Mutant tRNA genes defective in assembly of transcription initiation complexes and a temperature-sensitive RNA polymerase III mutant (rpc160-41) defective in initiation of transcription do not stall replication forks, suggesting that transcription is required for RFP activity.
Réactions des Méthylazide et Phénylazide Avec Quelques Alcynes et Oléfines α‐Nitrées. Synthèse Régiospécifique des 1,2,3 Triazoles (1996)

Abstract The reactions of alkynes and α‐nitro‐olefines with methylazide and phenylazide was studied. In contrast to known reactions with alkynes which are non‐regioselective, methylazide and phenylazide react regiospecifically with α‐nitro‐olefines and give only one type of triazole after elimination of HNO 2 . These reactions are very useful synthetic approaches to 1,2,3 triazoles.
Power series analyses of back-propagation neural networks (2002)

Presents a technique for analyzing backpropagation neural networks. Each hidden unit in the network is modeled as a power series of the net function. This approach allows determination of the degree of the overall polynomial discriminant, which approximates the network, potentially revealing the complexity of the decision boundary for the training data. Hidden units whose models are constant or have degree 1 can be pruned, thereby simplifying the network. The modeling technique can be used as a probe to investigate the success or failure of training. The approximation was applied to two example neural nets designed to perform nonlinear filtering tasks.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
SILICATE DUST SIZE DISTRIBUTION FROM HYPERVELOCITY COLLISIONS: IMPLICATIONS FOR DUST PRODUCTION IN DEBRIS DISKS (2011)

Fragments generated by high-velocity collisions between solid planetary bodies are one of the main sources of new interplanetary dust particles. However, only limited ranges of collision velocity, ejecta size, and target materials have been studied in previous laboratory experiments, and the collision condition that enables the production of dust-sized particles remains unclear. We conducted hypervelocity impact experiments on silicate rocks at relative velocities of 9 to 61 km s−1, which is beyond the upper limit of previous laboratory studies. Sub-millimeter–diameter aluminum and gold spheres were accelerated by laser ablation and were shot into dunite and basalt targets. We analyzed the surfaces of aerogel blocks deployed near the targets using an electron probe micro analyzer and counted the number of particles that contained the target material. The size distributions of ejecta ranged from five to tens of microns in diameter. The total cross-sectional area of dust-sized ejecta monotonically increased with the projectile kinetic energy, independent of impact velocity, projectile diameter, and projectile and target material compositions. The slopes of the cumulative ejecta-size distributions ranged from −2 to −5. Most of the slopes were steeper than the −2.5 or −2.7 that is expected for a collisional equilibrium distribution in a collision cascade with mass-independent or mass-dependent catastrophic disruption thresholds, respectively. This suggests that the steep dust size-distribution proposed for the debris disk around HD172555 (an A5V star) could be due to a hypervelocity collision.
Novel mechanism for the generation of human xeno-autoantibodies against the nonhuman sialic acid <i>N</i>-glycolylneuraminic acid (2010)

The nonhuman sialic acid N-glycolylneuraminic acid (Neu5Gc) is metabolically incorporated into human tissues from certain mammalian-derived foods, and this occurs in the face of an anti-Neu5Gc "xeno-autoantibody" response. Given evidence that this process contributes to chronic inflammation in some diseases, it is important to understand when and how these antibodies are generated in humans. We show here that human anti-Neu5Gc antibodies appear during infancy and correlate with weaning and exposure to dietary Neu5Gc. However, dietary Neu5Gc alone cannot elicit anti-Neu5Gc antibodies in mice with a humanlike Neu5Gc deficiency. Other postnatally appearing anti-carbohydrate antibodies are likely induced by bacteria expressing these epitopes; however, no microbe is known to synthesize Neu5Gc. Here, we show that trace exogenous Neu5Gc can be incorporated into cell surface lipooligosaccharides (LOS) of nontypeable Haemophilus influenzae (NTHi), a human-specific commensal/pathogen. Indeed, infant anti-Neu5Gc antibodies appear coincident with antibodies against NTHi. Furthermore, NTHi that express Neu5Gc-containing LOS induce anti-Neu5Gc antibodies in Neu5Gc-deficient mice, without added adjuvant. Finally, Neu5Gc from baby food is taken up and expressed by NTHi. As the flora residing in the nasopharynx of infants can be in contact with ingested food, we propose a novel model for how NTHi and dietary Neu5Gc cooperate to generate anti-Neu5Gc antibodies in humans.
Symbolleisten: Übersicht (1) (1992)

In der Version 4 haben die EXCEL-Entwickler das Steuern eines Anwendungsprogramms mit graphischen Elementen stark in den Vordergrund gestellt. Die Übersicht soll Ihnen eine Orientierung geben.
A Facile Synthesis of Polypyrrole/Carbon Nanotube Composites with Ultrathin, Uniform and Thickness-Tunable Polypyrrole Shells (2011)

An improved approach to assemble ultrathin and thickness-tunable polypyrrole (PPy) films onto multiwall carbon nanotubes (MWCNTs) has been investigated. A facile procedure is demonstrated for controlling the morphology and thickness of PPy film by adding ethanol in the reaction system and a possible mechanism of the coating formation process is proposed. The coated PPy films can be easily tuned by adding ethanol and adjusting a mass ratio of pyrrole to MWCNTs. Moreover, the thickness of PPy significantly influences the electronic conductivity and capacitive behavior of the PPy/MWCNT composites. The method may provide a facile strategy for tailoring the polymer coating on carbon nanotubes (CNTs) for carbon-based device applications.
Synthesis and Characterization of Ultra‐Fine Tin Oxide Fibers Using Electrospinning (2005)

Ultrafine tin oxide (SnO 2 ) fibers having a rutile structure, with diameter ranging from 100 nm to several micrometers, were synthesized using electrospinning and metallorganic decomposition techniques. In this work, we propose a precursor solution that is a mixture of pure SnO 2 sol made from SnCl 4 :H 2 O:C 3 H 7 OH:2‐C 3 H 7 OH at a molar ratio of 1:9:9:6, and a viscous solution made from poly(ethylene oxide) (PEO) (molecular weight 900 000) and chloroform (CHCl 3 ) at a ratio of 200 mg PEO/10 mL CHCl 3 . This solution allows to obtain an appropriate viscosity for the electrospinning process. The as‐deposited fibers were sintered at 400°, 500°, 600°, 700°, and 800°C in air for 2 h. Scanning electron microscopy, scanning probe microscopy, X‐ray diffraction, Raman microspectrometry, and X‐ray photoelectron spectroscopy (XPS) were used to characterize the sintered fibers and elucidate the chemical reaction during sintering. The results showed that up to the sintering temperature of 700°C, the synthesized fibers are composed of SnO 2 . XPS was found to reflect the complicate chemical changes caused by the sintering process.
Increasing Student Engagement in Math: The Use of Khan Academy in Chilean Classrooms (2014)

Khan Academy, an online platform offering educational videos and exercises in different content areas, has awakened intense interest among foundations, multilateral organizations, policy makers, and educators about how this tool can help meet the educational challenges facing countries around the world. With support from Intel, Education Development Center (EDC) researchers sought to understand how this technology fits into the complex realities of schools in a developing country. In August of 2013, researchers traveled to Santiago, Chile to conduct research in five schools where teachers are using Khan Academy. We found that the way Khan Academy functions as a digital learning environment changes the ways and the degree to which students engage with and are engaged by the math content; it also changes the way teachers and students interact with each other. Even though the use of Khan Academy may plant the seeds of deeper pedagogical changes such as mastery learning or differentiated instruction, teachers did not need to change their entire teaching model to start using it. Khan Academyâs straightforward approach of providing an endless bank of practice exercises makes it an inviting and universally adaptable tool across different types of teachers, classrooms, and countries.
Expression of Estrogen Receptor β in Rat Bone (1997)

A novel estrogen receptor, estrogen receptor beta (ERbeta), has recently been cloned from a rat prostate cDNA library. In bone, which is an important target tissue of estrogen, ER alpha has been reported to be present preferentially in osteoblasts, but the mechanism of action of estrogen in bone is still not known. In the present study, we examined expression of ERbeta mRNA in bone. Expression of ERbeta mRNA was evident in primary osteoblastic cells isolated from 1-day-old rat calvaria and rat osteosarcoma cells (ROS 17/2.8), and its level was higher than that of ER alpha mRNA. When osteoblastic cells were cultured for 28 days to induce differentiation into mature osteoblasts capable of forming bone nodules, ERbeta mRNA was constantly and highly expressed during the entire culture period. In contrast, the level of ER alpha mRNA was very low at the beginning of culture and it gradually increased during the differentiation of osteoblastic cells. Various tissues including bone were isolated from 8-week-old rats of both sexes, and total RNA was extracted to compare the tissue distribution of expression levels of ERbeta mRNA. In cancellous bone of the distal femoral metaphysis and lumbar vertebra, expression of ERbeta mRNA was obvious, and its level was equivalent to those in the uterus and testis, but lower than those in the ovary and prostate. The level of ERbeta mRNA in femoral cortical bone was lower than that in cancellous bone. There was no appreciable differences between female and male rats in the distribution and expression levels of ERbeta mRNA in bone. These results indicate that ERbeta mRNA is highly expressed in osteoblasts in rat bone, suggesting that there is a distinct mechanism of estrogen action mediated by ERbeta in bone.
A theoretical analysis of interrupter technique for measuring respiratory mechanics (1988)

The application of the flow interrupter technique to series and parallel models of the respiratory system is examined theoretically, assuming instantaneous transmission of pressures and incompressible gases in the lung air spaces. The initial pressure change observed immediately after occlusion divided by the preocclusion flow gives an initial resistance (Rinit) equal to that of the airway tree when the model consists of compartments connected in parallel. When the compartments are connected in series, Rinit is the resistance of the most proximal airway only. In general, the initial pressure change is followed by a second slower change, reflecting equilibration of pressures between the compartments. The total postocclusion pressure change divided by the flow gives a steady-state resistance (Rss) whose value depends on the ventilation history before occlusion. When this history consists of a relaxed expiration Rss asymptotes from Rinit to a value higher than the zero-frequency resistance of the model as the expiratory time increases. However, the relative contributions of serial and parallel pendelluft and viscoelasticity to Rss cannot be determined from pressure and flow measurements made at the airway opening. Therefore in disease, the interrupter method does not permit one to say whether ventilation inhomogeneity or alteration in lung tissue properties is the predominant abnormality.
Origin of the endurance degradation in the novel HfO<inf>2</inf>-based 1T ferroelectric non-volatile memories (2014)

Novel HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -based non-volatile ferroelectric field effect transistors (FeFETs) reveal integration and scaling properties superior to the devices utilizing perovskite-type ferroelectrics. However, until now the switching endurance of only 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sup> program/erase cycles could be proven. The mechanisms responsible for the cycling degradation have been scarcely studied so far. Therefore, the scope of this paper is to clarify the origin of the cycling degradation in HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -based FeFETs. Several possible degradation mechanisms - fatigue of the ferroelectric layer and degradation of the transistor gate stack - are proposed and investigated. The limited endurance properties were found to be linked to the transistor gate stack reliability rather than to the ferroelectric material itself. The gate leakage current measurements and the trapping analyses presented in this paper identified a degradation of the interfacial layer in the gate stack, which in turn is strongly linked to a reduction of ferroelectric memory window.
Container System Design Developments Over Two Decades (1982)

This paper reviews the progress made over the past 20 years in the design and handling of containers. Factors influencing present container dimensions and strength criteria are discussed, as well as the crucial activity to establish container standardization. The container itself—"the common denominator"—is addressed from the viewpoint of its fittings, design loads and construction materials; and the containership from the viewpoint of arrangements, size, speed, stability, stowage and economics. The author offers several conclusions following the last two sections of the paper, which cover the remaining components of the system, namely, the shoreside gantry cranes and terminal facilities.
Fabrication of Silver Nanowire-Graphene Oxide Hybrid Transparent Conductive Thin Film with Improved Mechanical Stability (2015)

In this study, we used GO (graphene oxide) in order to enhance the adhesion between Ag NWs (nanowires) and substrates. By using a mixture solution of GO and Ag NW, a vacuum filtration process was used to fabricate a 50nm diameter thin film. Next, by using a light annealing process, the mechanical and electrical stability of Ag NW network was improved without any other treatment. The physical properties of the Ag NW - GO hybrid transparent conductive thin film was characterized in terms of a bending test, resistance and transmittance test, and nanoscale imaging using field-emission scanning electron microscopy.