gebhart/patrepeval huggingface dataset:
Neutralization of influenza virus by low concentrations of hemagglutinin-specific polymeric immunoglobulin A inhibits viral fusion activity, but activation of the ribonucleoprotein is also inhibited (1992)

High concentrations of hemagglutinin-specific neutralizing polymeric monoclonal immunoglobulin A (IgA) inhibit attachment of the majority of type A influenza virus virions to cell monolayers and tracheal epithelium (H. P. Taylor and N. J. Dimmock, J. Exp. Med. 161:198-209, 1985; M. C. Outlaw and N. J. Dimmock, J. Gen. Virol. 71:69-76, 1990). A minority of virions attaches but is not infectious. Here, we report that a different mechanism operates when influenza virus A/Puerto Rico/8/34 (H1N1) is neutralized by low concentrations of monoclonal polymeric IgA or when A/fowl plague virus/Rostock/34 (H7N1) is neutralized by low concentrations of polyclonal rat secretory IgA. Under these conditions, neutralized virus attaches to cells and is taken up by them. However, upon entering the cell, the nucleoprotein (NP) of neutralized virus is found in the perinuclear cytoplasm, whereas NP from nonneutralized virus is concentrated in the nucleus itself. Further data show that the low-pH-mediated cell fusion activity of virions is inhibited by IgA in proportion to loss of infectivity. The possibilities that neutralization by low amounts of polymeric IgA is caused by inhibition of the virion fusion activity and that the aberrant distribution of NP from neutralized virus results from its failure to escape from the endosomal system were investigated by using A/PR/8/34 and the fusogenic agent polyethylene glycol (PEG) at pH 5.4. A/PR/8/34 attached to cells at 4 degrees C, with minimal internalization of the virus; treatment with PEG at pH 5.4 and 4 degrees C for 1 min led to infectious fusion of nonneutralized virus with the plasma membrane and, under these conditions, was more efficient than PEG at pH 7 or medium at pH 5.4. Neutralized virus which was attached to cells and treated with acidified PEG appeared to undergo primary and secondary uncoating, with its NP protein becoming concentrated in the nucleus and M1 becoming concentrated in the perinuclear cytoplasm. Although the distribution of NP and M1 was indistinguishable from infectious virus, infectivity was not restored. Thus, even when IgA-induced inhibition of fusion is reversed, virus is still neutralized. We suggest that infectious influenza virus undergoes an activation stage which may be the relaxation of the ribonucleoprotein structure needed to permit transcription or may be the removal of M1 bound to the ribonucleoprotein.(ABSTRACT TRUNCATED AT 400 WORDS)
Field Conjugation Adaptive Arrays in Free-Space Coherent Laser Communications (2011)

We analyze the performance of adaptive field conjugation array receivers in coherent laser communications through the turbulent atmosphere. We consider coherent fiber arrays consisting of densely packed multiple subapertures, with each subaperture interfaced to a single-mode fiber. In a field conjugation fiber array, the single-mode fiber outputs are detected, and the photocurrents are adaptively co-phased and scaled, and then summed to mitigate signal fading associated with atmospheric turbulence and compensate for imperfect fiber coupling efficiency. We quantify how field conjugation processing improves performance in the presence of turbulence, as compared to a monolithic-aperture coherent receiver having an equal total cross-sectional area.
Autocorrelation of ultrashort pulses at 1.5 µmbased on nonlinear response of silicon photodiodes (1996)

Measurements of the autocorrelation function of picosecond pulses at 1.5 µm from an erbium-doped fibre laser and amplifier have been carried out, exploiting a nonlinear intensity-dependent response in a silicon photodiode. The same photodiode is used both for the generation and the detection of the autocorrelation signal, allowing the construction of a compact and inexpensive optical autocorrelator.
Performance analysis for UMTS networks with queued radio access bearers (2002)

The Universal Mobile Telecommunications System (UMTS) network consists of a core network (CN) and a UMTS terrestrial radio access network (UTRAN). The UTRAN offers radio access bearer (RAB) services between the user equipment (UE) and the CN to support mobile multimedia applications with different quality of service (QoS) requirements. Depending on the requested QoS, different types of RABs can be established at the request of the CN. The UTRAN then has to establish and maintain the RAB with the requested QoS. We study the queueing of RABs as a means for improving the bandwidth utilization while minimizing the RAB blocking probability. We develop an analytical model to study the performance for UTRAN with queued RABs in terms of RAB blocking probability and average queueing time of queued RABs. From an analytic point of view, the main contribution of this paper is the introduction of a novel recursion for the computation of the performance measures.
Automated design of folded-cascode op-amps with sensitivity analysis (2002)

We present a method for optimizing and automating component and transistor sizing in CMOS operational amplifiers. We observe that a wide variety of performance measures can be formulated as posynomial functions of the design variables. As a result, amplifier design problems can be expressed as geometric programs, as special type of convex problem for which very efficient global optimization methods exist. A side benefit of using convex optimization is that a sensitivity analysis is obtained with the final solution with no additional computation. This information is of great interest to analog circuit designers. The method we present can be applied to a wide variety of amplifier architectures, but in this paper we apply the method to a specific two-stage amplifier architecture.
Synthesis of Carbon-Encapsulated Metal Nanoparticles from Wood Char (2010)

Carbon-encapsulated metal nanoparticles were synthesized by thermal treatment of wood char, with or without transition metal ions pre-impregnated, at 900&deg;C to 1,100&deg;C. Nanoparticles with concentric multilayer shells were observed. The nanoparticles were analyzed by scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), and energy dispersive X-ray (EDX) spectroscopy. The EDX spectrum showed that carbon was the dominant element in the shells. TEM and XRD analysis indicated that the generated carbon shells had structures similar to that of graphite with an average interplanar distance of 0.34 nm. The effects of temperature and pre-impregnation of metal ions on the yield of carbon-encapsulated metal nanoparticles were studied.
Modeling of a Shape Memory Integrated Actuator for Vibration Control of Large Space Structures (1991)

Martin Marietta is developing a shape memory material actuator to pro vide active vibration and shape control for large, adaptive space structures. An important facet of this work is the development of analytical modeling capabilities for shape memory material behavior. These alloys exhibit a very interdependent force-length-temperature (FLT) response, which must be understood to best exploit their behavior for the efficient and timely conversion of heat into mechanical work. Also, the modal response of large, flexible space structures will be affected by the use of inherently non-linear, hysteretic shape memory actuators, and specialized control methodologies need to be developed spe cific to this application. In this work, Cory and McNichols' theory of non-equilibrium thermostatics (NET) was modified to account for the multiple quadrant (i.e., tension and compression) hysteretic behavior of shape memory alloys. Experimental results were used to provide the basis for spatial mapping of the austenite-to-martensite ( AM) and mar tensite-to-austenite ( MA) phase transformation boundaries, along with the relative loca tions of the 100% austenite ( Z A ) and 100% aligned martensite ( Z M ) saturation surfaces in the three-dimensional FLT material behavior domain. A Fortran subroutine, describing the shape memory material actuator, was incorporated into dynamic analyses of a simpli fied finite element model based on the Spacecraft Control Laboratory Experiment (SCOLE) structure. A slewing maneuver of 20 degrees in 12 seconds was used to study a number of cases for the shape memory actuator which utilized a biasing force (e.g., the biasing effect of a matrix in a strain-compliant shape memory composite) acting against 150 NiTi wires (0.5 mm dia. by 0.50 m in length). Temperature was used as the command variable to demonstrate active vibration control during and after the slew maneuver. Sig nificant passive damping was noted, in addition to effective active control when the actua tor's temperature was pulsed. This analytic "test bed" will provide critical insight into the design and analysis of smart, adaptive shape memory space truss tubes and actuators for vibration and shape control, as well as the vehicle by which future shape memory actuator control algorithms and methodologies can be assessed.
O curso de biblioteconomia na Universidade de Brasília (2012)

Entrevista do prof. Edson Nery da Fonseca, professor emérito da Universidade de Brasília, a profª Maria Alice Borges Guimarães, que apresenta um panorama das bibliotecas brasileiras. &nbsp; A entrevista foi promovida pelo Projeto Informação e Memória, desenvolvido pelo Núcleo de Editoração e Comunicação da Faculdade de Ciência da Informação e integra a Série Diálogos produzida pela UnBTV. Confira também o vídeo da entrevista, disponível nesta edição.
Integration of a Highly Selective Demethylation of a Quaternized Ergoline into a One-Pot Synthesis of Pergolide (1997)

We have developed a high-yielding one-pot synthesis of pergolide (10) from dihydrolysergol (1), which was isolated as pergolide mesylate (6, Permax), a semisynthetic ergot alkaloid marketed for the adjunctive treatment of Parkinson's disease. The process involved the formation of quaternized amine intermediates, followed by a highly selective demethylation and thioether formation via thiomethoxide ion. A novel tandem chromatography procedure was used to remove closely related byproducts, which included an unexpected and unusual thiomethyl ether homologue of pergolide.
v-Myb of E26 leukemia virus up-regulates bcl-2 and suppresses apoptosis in myeloid cells. (1996)

Many oncogenes have been shown to be deregulated transcription factors, yet direct target genes mediating cell transformation remain elusive. Here we describe such a target for v-Myb by exploiting a temperature-sensitive mutant of the E26 avian leukemia virus encoding Myb-Ets. Myeloblasts transformed by the mutant differentiate into macrophages or die by apoptosis when shifted to the nonpermissive temperature as a result of inactivation of v-Myb. During this process mRNA of the antiapoptotic oncoprotein Bcl-2 is down-regulated with kinetics similar to those of Mim-1, a differentiation-related protein whose expression is directly regulated by Myb. Forced expression of bcl-2 rescues the cells from apoptosis, without preventing either their withdrawal from the cell cycle or their differentiation. v-Myb appears to act directly on the bcl-2 gene, because a bcl-2 promoter-driven reporter is activated by Myb-Ets and v-Myb-VP16 and requires intact Myb binding sites within the promoter. Surprisingly, inactivation of v-Myb in multipotent progenitors transformed by E26 virus does not induce apoptosis, indicating that bcl-2 regulation by the oncoprotein is required for the transformation of some cell types but not others.
New Triterpenoid Saponins from <i>Gynostemma </i><i>pentaphyllum</i> (1996)

Three new triterpenoidal saponins (1-3), together with the known compound 4, were isolated from a MeOH extract of the aerial parts of Gynostemma pentaphyllum. Their structures were elucidated on the basis of chemical and spectral methods, such as 1H-1H DQFCOSY, HMQC, HMBC, and TOCSY NMR spectra. The aglycon moiety of 1 and 2 is a new dammarane-type triterpene 12-oxo-2 alpha, 3 beta, 20 (S)-trihydroxydammar- 24-ene.
Continuous Cold-Atom Inertial Sensor with<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mn>1</mml:mn><mml:mtext> </mml:mtext><mml:mtext> </mml:mtext><mml:mi>nrad</mml:mi><mml:mo>/</mml:mo><mml:mi>sec</mml:mi></mml:mrow></mml:math>Rotation Stability (2016)

We report the operation of a cold-atom inertial sensor which continuously captures the rotation signal. Using a joint interrogation scheme, where we simultaneously prepare a cold-atom source and operate an atom interferometer (AI), enables us to eliminate the dead times. We show that such continuous operation improves the short-term sensitivity of AIs, and demonstrate a rotation sensitivity of $100\text{ }\text{ }\mathrm{nrad}/\mathrm{sec}/\sqrt{\mathrm{Hz}}$ in a cold-atom gyroscope of $11\text{ }\text{ }{\mathrm{cm}}^{2}$ Sagnac area. We also demonstrate a rotation stability of $1\text{ }\text{ }\mathrm{nrad}/\mathrm{sec}$ at ${10}^{4}\text{ }\text{ }\mathrm{sec}$ of integration time, which represents the state of the art for atomic gyroscopes. The continuous operation of cold-atom inertial sensors will lead to large area AIs at their full sensitivity potential, determined by the quantum noise limit.
Mapping genes of complex psychiatric diseases in Daghestan genetic isolates (2004)

Genetic isolates, which provide outstanding opportunities for identification of susceptibility genes for complex diseases, can be classified as primary (having an ancient demographic history in a stable environment) or secondary (having a younger demographic history) Neel [1992: Minority populations: Genetics, demography, and health, pp. 1-13]. Daghestan contains 26 out of 50 indigenous Caucasus ethnicities that have been in existence for hundreds of generations in the same highland region. The ethnic groups are subdivided into numerous primary isolates. The founder effect and gene drift in these primary isolates may have caused aggregation of specific haplotypes with limited numbers of pathogenic alleles and loci in some isolates relative to others. These are expressed as inter-population differences in lifetime prevalence and features of certain complex clinical phenotypes and in patterns of genetic linkage and linkage disequilibrium (LD). Stable highland and ethnic-cultural environments have led to increased penetrance and a reduced number of phenocopies, which typically hamper the identification of any susceptibility genes for complex diseases. Owing to these characteristics of the primary isolates, a comparative linkage study in the primary isolates allows us to define the number of susceptibility genes for any complex disease and to identify the source of variability and non-replication of linkage analysis results. As part of an ongoing study, seven extended schizophrenia and one nonspecific mental retardation kindreds have been ascertained from Daghestan isolates. Lifetime morbid risk for schizophrenia in the isolates varied from 0 to 5%. A genome scan with markers spaced 10 cM apart was carried out on these pedigrees and linkage analysis was performed using descent graph methods, as implemented in Simwalk2. To identify regions containing susceptibility genes within these kindreds, we followed up those regions with non-parametric and parametric linkage analyses, with the choice of genetic model guided by the results obtained in the NPL. While the analyses are ongoing, the most positive findings were made in different isolated pedigrees on chromosomes 17p11, 3q24, and 22q for schizophrenia and on chromosome 12q for nonspecific mental retardation.
Self‐reported use of shared decision‐making among breast cancer specialists and perceived barriers and facilitators to implementing this approach (2004)

The response rate was 79% for oncologists and 72% for surgeons. More physicians from each specialty (87% of oncologists and 89% of surgeons) expressed high levels of comfort with clinical example 4 (designed to illustrate a shared approach) than with any of the other examples presented (e.g. the informed and paternalistic approach). Similarly, more oncologists and surgeons reported that their usual approach to treatment decision-making was like example 4 than like any other approach presented (56% of oncologists and 69% of surgeons, respectively). Comfort levels with example 4 for oncologists and surgeons were 31% and 20% higher, respectively, than the reported use of this approach. Lack of time and patient anxiety, patient lack of information and/or misinformation, and patient unwillingness or inability to participate were perceived by a substantial minority of both oncologists and surgeons as barriers to patient involvement in treatment decision-making. Key facilitators identified included patients' emotional readiness, support, information and trust in the physician. More research is needed to identify contextual, physician, patient, and interaction factors that will facilitate shared decision-making in the medical encounter and help both parties create an environment conducive to implementing this approach to the extent desired.
Minimum-Weight Design for Pressure Vessels Reinforced With Inextensible Fibers (1963)

Axially symmetric membranes composed of inextensible fibers are considered. When the shape of the membrane and the tensile strength of the fibers are given, the minimum weight of fiber which can support a given internal pressure is proportional to the volume enclosed by the membrane. Minimum weight designs are isotensoid, i.e., every fiber is under the same tension. Every isotensoid design is a minimum weight design. Particular attention is devoted to geodesic isotensoid designs, in which fibers are required to lie along geodesics on the membrane. The equation relating the shape of the membrane to the distribution of fibers on it is obtained. When the shape is given, this equation is an integral equation for the fiber distribution, which is solved by using the Laplace transform. Illustrative examples involving cones, spheres, ellipsoids, and cylinders are solved.
Follistatin Suppresses the Production of Experimental Multiple-Organ Metastasis by Small Cell Lung Cancer Cells in Natural Killer Cell–Depleted SCID Mice (2008)

These results suggest that FST plays a critical role in the production of multiple-organ metastasis, predominantly by inhibiting the angiogenesis. This is the first report to show the role of FST in metastases.
Influence of Oilfield Chemicals on the Surface Tension of Stimulating Fluids (1999)

Abstract Surface tension plays a very important role in the stimulation of gas wells. A low surface tension is required to reduce capillary forces that trap the aqueous phase in the formation. Accumulation of the aqueous phase near the wellbore area, known as water blockage, leads to a significant reduction in gas production. An experimental study was conducted to examine the effects of various acids and stimulation additives on surface tension. A Krüss tensiometer (Model K-12) was used to conduct surface tension measurements. Acids examined included: HCl, acetic, citric, formic, and combinations of these acids. Stimulation additives tested included: mutual solvent, short-chain alcohols, corrosion inhibitors, hydrogen sulfide scavengers, iron-control agents, and clay stabilizers. In addition, the effects of three classes of surfactants (nonionic, cationic and anionic) on surface tension of acid solutions were investigated. The surface tension of acid stimulating fluids is a complex function of acid type, concentration, and additive type and concentration. Acetic and formic acids had lower surface tension values than HCl, especially at high acid concentrations. The surface tension of the organic acids examined depended on the pKa value of the acid. Organic acids with high pKa values had low surface tension values. The surface tension of hydrochloric acid can be reduced by mixing with acetic acid. EGMBE lowered the surface tension of acetic, formic and hydrochloric acids up to 10 wt%. Increasing the concentration of EGMBE above 10 wt% had no significant effect on the surface tension of these acids. The effect of organic acid strength on surface tension diminished in the presence of EGMBE. Short-chain alcohols reduced the surface tension of 15 wt% HCl with the greatest reduction obtained with n-butanol. Citric and erythorbic acids, which are usually used as iron control agents significantly reduced the surface tension of 15 wt% HCl. Ionic surfactants reduced the surface tension of hydrochloric acid more than the two nonionic surfactants tested. The three corrosion inhibitors examined reduced surface tension up to a critical concentration beyond which they had no effect on surface tension. An aldehyde-based H2S scavenger lowered the surface tension of 15 wt% acid solutions at very low concentrations. Clay stabilizers (cationic polymers) did not significantly affect the surface tension of 15 wt% HCl. Addition of a hydrogen sulfide scavenger, a nonionic surfactant or a corrosion inhibitor into solutions of 15 wt% HCl and EGMBE had a small effect on the surface tension of the acid.
Alterations in myofibrillar function and protein profiles after complete global ischemia in rat hearts. (1992)

We studied changes in myofibrillar function and protein profiles after complete global ischemia with anoxia in rat hearts. Hearts were exposed to global ischemia and anoxia (CGI) for 30 or 60 minutes at 37 degrees C, and myofibrils were prepared for measurement of Ca(2+)-dependent Mg(2+)-ATPase activity at pH 7.0 and 6.5. Hearts incubated in cold saline (1 +/- 1 degrees C) and nonincubated hearts served as controls. Maximum ATPase activity was unchanged at pH 7.0 and pH 6.5 in myofibrils from hearts treated with 30 or 60 minutes of CGI. At pH 7.0, the Hill coefficient, which is an index of cooperative interactions among thin-filament proteins, was unchanged after 30 minutes of CGI but was significantly increased after 60 minutes of CGI. A similar trend for increased cooperativity was observed when myofibrillar ATPase activity was measured at pH 6.5 in myofibrils from rat hearts made ischemic for 30 or 60 minutes. Both 30 and 60 minutes of CGI resulted in increased pCa50 values (half-maximally activating free [Ca2+]) at pH 7.0 and pH 6.5. Densitometric analysis of myofibrillar proteins separated with sodium dodecyl sulfate-polyacrylamide gel electrophoresis indicated that troponin I and troponin T were degraded during 60 minutes of CGI. Two new protein bands appearing in ischemia-treated myofibrils were identified as partially degraded troponin I and troponin T with Western blots. The troponin I fragment could be phosphorylated by cAMP-dependent protein kinase. In addition, we observed phosphorylation of a protein band that corresponded to myosin light chain-2 in myofibrils from CGI-treated hearts. These results suggest that degradation of thin-filament proteins may contribute to the changes in cooperativity of Ca2+ regulation of ATPase activity observed in the myofibrils from rat hearts exposed to CGI.
Lower serum activity of prolyl endopeptidase in fibromyalgia is related to severity of depressive symptoms and pressure hyperalgesia (1998)

The results show that fibromyalgia, and aberrant pain perception and depressive symptoms in fibromyalgia are related to lower serum PEP activity. It is hypothesized that lower serum PEP activity may play a role in the biophysiology of fibromyalgia through diminished inactivation of algesic and depression-related peptides.