gebhart/patrepeval huggingface dataset:
Properties of the 40 kDa antigen of Mycobacterium tuberculosis, a functional L-alanine dehydrogenase (1999)

The 40 kDa antigen of Mycobacterium tuberculosis is the first antigen reported to be present in the pathogenic M. tuberculosis, but not in the vaccine strain Mycobacterium bovis BCG. It is a functional L-alanine dehydrogenase (EC 1.4.1.1) and hence one of the few antigens possessing an enzymic activity. This makes the 40 kDa antigen attractive for potential diagnostic and therapeutic interventions. Recently, we developed a strategy to purify quantities of the recombinant protein in active form, and here we describe the biochemical properties of this enzyme. In the oxidative-deamination reaction, the enzyme showed K(m) values of 13. 8 mM and 0.31 mM for L-alanine and NAD(+), respectively, in a random-ordered mechanism. K(m, app) values in the reductive-amination reaction are 35.4 mM, 1.45 mM and 98.2 microM for ammonium, pyruvate and NADH, respectively. The enzyme is highly specific for all of its substrates in both directions. The pH profile indicates that oxidative deamination virtually may not occur at physiological pH. Hence L-alanine most likely is the product of the reaction catalysed in vivo. The enzyme is heat-stable, losing practically no activity at 60 degrees C for several hours.
Optical, electrical, and structural properties of amorphous Ag–Ge–S and Ag–Ge–Se films and comparison of photoinduced and thermally induced phenomena of both systems (1996)

To understand the nature of Ag-rich chalcogenide glasses, the optical, electrical, and structural properties of evaporated amorphous (Ge0.3S0.7)100−xAgx and (Ge0.3Se0.7)100−yAgy films have been examined and compared with each other over a wide compositional range in Ag content. The maximum Ag content for the amorphous films was 67 at. % for the S-based system and 40 at. % for the Se-based system. The physical properties of both systems depended significantly on the Ag content but the compositional trends resembled each other. All the photoinduced and thermally induced phenomena observed for the S-based system were also observed for the Se-based system but with the compositional ranges shifted to lower Ag concentration: the photo- and thermal bleachings (0≤y&lt;22 for the Se-based system, 0≤x&lt;40 for the S-based system), the photoinduced surface deposition (PSD) of metallic Ag phenomenon, and the phase separation on annealing (25&lt;y≤40, 50&lt;x≤67). The Se-based system was found to exhibit the PSD phenomenon at low Ag concentrations where the S-based system never exhibits this effect.
Correction to: Simple Model of Corner Reflector Phenomena (1971)

Get PDF Email Share Share with Facebook Tweet This Post on reddit Share with LinkedIn Add to CiteULike Add to Mendeley Add to BibSonomy Get Citation Copy Citation Text H. D. Eckhardt, "Correction to: Simple Model of Corner Reflector Phenomena," Appl. Opt. 10, 2547-2547 (1971) Export Citation BibTex Endnote (RIS) HTML Plain Text Citation alert Save article
Defining the Role of Oxygen Tension in Human Neural Progenitor Fate (2014)

Hypoxia augments human embryonic stem cell (hESC) self-renewal via hypoxia-inducible factor 2α-activated OCT4 transcription. Hypoxia also increases the efficiency of reprogramming differentiated cells to a pluripotent-like state. Combined, these findings suggest that low O2 tension would impair the purposeful differentiation of pluripotent stem cells. Here, we show that low O2 tension and hypoxia-inducible factor (HIF) activity instead promote appropriate hESC differentiation. Through gain- and loss-of-function studies, we implicate O2 tension as a modifier of a key cell fate decision, namely whether neural progenitors differentiate toward neurons or glia. Furthermore, our data show that even transient changes in O2 concentration can affect cell fate through HIF by regulating the activity of MYC, a regulator of LIN28/let-7 that is critical for fate decisions in the neural lineage. We also identify key small molecules that can take advantage of this pathway to quickly and efficiently promote the development of mature cell types.
Equilibrium and Dynamic Surface Tension Properties of Partially Fluorinated Quaternary Ammonium Salt Gemini Surfactants (2006)

The equilibrium and dynamic surface tension properties of a partially fluorinated quaternary ammonium salt gemini surfactant 1,2-bis[dimethyl-(3-perfluoroalkyl-2-hydroxypropyl)ammonium]ethane bromide (C(n)(F)C3-2-C3C(n)F, where n represents fluorocarbon chain lengths of 4, 6, and 8) were investigated, and the effects of the fluorocarbon chain length and the number of chains on them were discussed. The plot of the logarithm of the critical micelle concentration (cmc) against the fluorocarbon chain length for C(n)(F)C3-2-C3C(n)F showed a linear decrease with an increase in chain length. On the basis of the slope of this plot, it was found that the variation in cmc with respect to the chain length is large for fluorinated gemini surfactants. The surface tension at the cmc decreased significantly; this surface tension value is lower than that of conventional fluorinated monomeric surfactants. In particular, the lowest value was 13.7 mN m(-1) for n = 8. Furthermore, it was confirmed that the kinetics of adsorption at the interface decrease with an increase in the fluorocarbon chain length and the concentration.
Pharmacodynamic biomarkers of outcomes in the phase III study of lenvatinib in <sup>131</sup>I-refractory differentiated thyroid cancer (SELECT). (2015)

6014 Background: Lenvatinib (LEN)–an oral multikinase inhibitor of VEGFR1–3, FGFR1–4, PDGFRα, RET, and KIT—significantly prolonged progression-free survival (PFS) vs placebo (PBO) in the SELECT study. Baseline (BL) Ang2 levels were previously identified as prognostic and predictive of LEN response, and increase in FGF23 levels is a surrogate pharmacodynamic biomarker of FGFR1 inhibition. Here we investigated serum circulating cytokine/angiogenic factors (CAFs) as potential pharmacodynamic biomarkers of LEN efficacy and disease progression in SELECT. Methods: Blood samples from 387/392 (99%) randomized patients (pts) were collected at baseline, cycle 1 day 15 (C1D15), day 1 of subsequent cycles, and treatment end. TG and CAF levels (Ang2, VEGF, sTie2, and FGF23) were measured by ELISA. Results: From cycle 1,VEGF levels were consistently elevated for pts on LEN, whereas Ang2 and sTie2 levels were consistently decreased compared with PBO. FGF23 levels increased by 20.8% (C1D15) and 28.6% (C2D1). Although TG decreases in LEN pts were correlated with tumor shrinkage (TS; P < 0.0001) and objective response rate (ORR; P < 0.05, through C9D1), TG decreases also occurred in pts with stable or progressive disease. Increased VEGF (P < 0.0001) and decreased Ang2 (P < 0.0001) and sTie2 (P < 0.0001) levels also correlated with TS, but not with ORR. Amongst LEN-treated pts with disease progression, decreased levels of TG (31/34 pts, P < 0.0001), Ang2 (32/38 pts, P < 0.0001), and sTie2 (39/42 pts, P < 0.0001) at C2D1 compared to BL were observed. However, at treatment end, increased levels of TG, Ang2, and sTie2 from C2D1 were observed in 79.4%, 78.9%, and 81.0% of these pts, respectively. In some cases, these increases occurred prior to disease progression. Conclusions: TG changes were correlated with TS and ORR in the LEN arm of SELECT; CAF analyses may provide additional information.Increased levels of VEGF and FGF23 may indicate that LEN is targeting these signaling networks in pts with RR-DTC in SELECT. Preliminary analyses of pts who progressed on LEN indicated elevated levels of Ang2 and sTie2. Further analyses of the Ang2/Tie2 axis using serum biomarkers are warranted. Clinical trial information: NCT01321554.
Experimental lung nodule model: CT numbers, nodule size, and actual calcium content. (1983)

An experimental pulmonary nodule model was developed to study the effect of nodule size, nodule environment, and calcium content on the attenuation values in two computed tomography (CT) scanners. The experimental results show that (a) calcium is the moiety most responsible for the CT number, (b) small nodules may have falsely low CT numbers, (c) CT numbers vary from scanner to scanner when scanning the same nodule, and (d) higher CT numbers are obtained when experimental nodules are scanned in air rather than water.
Monoamine depletion studies: implications for antidepressant discontinuation syndrome. (2006)

The likelihood of a connection between serotonin reuptake inhibitor (SRI) discontinuation and an acute reduction in synaptic serotonin (5-HT) has ignited interest in the similarities between SRI discontinuation syndrome and the symptoms observed after acute tryptophan depletion, which reduces synaptic 5-HT levels. An open question is whether these 2 phenomena have shared characteristics because of a similar underlying mechanism. The evidence in support of a similar underlying mechanism includes the observation that comparable proportions of SRI-treated patients experience depressive symptoms following tryptophan depletion and SRI discontinuation. Furthermore, the proportion of people who have emotional changes with rapid antidepressant discontinuation may be parallel to the proportion of people who experience those changes with rapid tryptophan depletion.
Melatonin in seasonal affective disorder and phototherapy. (1986)

In several studies we have found that treatment with bright environmental light, capable of suppressing human melatonin, reverses the winter depressive symptoms of patients with seasonal affective disorder (SAD), whereas light too dim to suppress human melatonin is therapeutically ineffective. This finding, as well as the central importance of melatonin as a hormonal mediator of photoperiodic changes on seasonal rhythms in animals, led us to test the hypothesis that melatonin mediates the effects of shortening days on the winter symptoms of SAD and that the modification of melatonin secretion by bright light mediates its antidepressant effects. We partially reversed the antidepressant effects of phototherapy in 8 SAD patients by oral melatonin administration, but in another study of 19 SAD patients we failed to find any therapeutic difference between the beta-adrenergic blocker, atenolol, which inhibits melatonin secretion, and placebo. In a third study of 7 SAD patients we showed that the anti-depressant effects of phototherapy were not photoperiodic and appeared to be independent of melatonin suppression. There is some preliminary evidence that melatonin secretion may be abnormal in SAD. We conclude that while melatonin may play some role in the symptoms of SAD and the effects of phototherapy, it cannot by itself account for these phenomena.
Functional Immaturity of the Colon (2012)

▶ Contrast enema (right) demonstrates small caliber of the left colon (arrowheads) but normal rectosigmoid ratio, and an abrupt transition at the splenic flexure (arrow). The patient passed a meconium plug at the end of the procedure....
Protease‐catalyzed incorporation of <sup>18</sup>O into peptide fragments and its application for protein sequencing by electrospray and matrix‐assisted laser desorption/ionization mass spectrometry (1996)

Proteins were digested in normal and highly 18O-enriched water using proteases commonly employed for protein sequencing. The extent of 18O incorporation into the resulting peptide fragments was characterized by electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS). The endoproteinases trypsin, Lys-C and Glu-C incorporate two atoms of 18O, resulting in a mass shift of +4 D for the peptide fragments. This indicates that, following proteolytic cleavage, peptide products continue to interact with these proteases and undergo repeated binding/hydrolysis cycles, resulting in complete equilibration of both oxygens in the carboxy terminus of the fragments with oxygen from solvent water. In contrast, chymotrypsin and Asp-N incorporate only one atom of 18O, resulting in a mass shift of +2 D, indicating that after the cleavage step these proteases do not accept the peptides as substrates. In addition, it was found that the proteases trypsin, Glu-C, and Lys-C exhibit minor or nontypical sequence specificities, resulting in unexpected peptide fragments. These fragments incorporate only one 18O atom, indicating that they do not undergo further binding/hydrolysis cycles with the enzyme. Thus, it is possible to discriminate between enzyme-typical peptide fragments with mass shifts of +4 D and nontypical fragments with mass shifts of only +2 D. Based on these observations, protein digest strategies are described for the generation of 1:1 ion doublets spaced either by 2 or 4 D. In addition, the C-terminus of a protein can be identified by the absence of an ion doublet in the corresponding peptide fragment. In protein sequencing by mass spectrometry, digest protocols generating ion doublets provide the most clear-cut analytical results for the recognition of ion series in ESI-MS/MS and MALDI post-source decay (PSD) product ion spectra. Only the mass spectrometric fragment ions of a C-terminal series show ion doublets spaced either by 2 or 4 D, whereas the fragment ions belonging to an N-terminal series remain unshifted. This assignment unequivocally reveals the direction of the identified sequence.
The impact of phenylalanine levels on cognitive outcomes in adults with phenylketonuria: Effects across tasks and developmental stages. (2017)

Results show the importance of selecting the right tasks to monitor outcomes across ages, but also that the impact of bio-chemical disruptions is different for different functions, at different ages. We show how inherited metabolic diseases offer us a unique vantage point to inform our understanding of brain development and functioning. (PsycINFO Database Record
Shared cache - the future of parallel databases (2005)

It is a common misconception that the shared nothing database is the preferred parallel database architecture for both scalability as well as price/ performance. This paper explains that, contrary to popular belief, a shared-cache architecture as implemented in Oracle 9i Real Application Clusters (RAC) is not only viable but also the future of parallel database architectures. We argue that business needs, hardware trends and database application trends favor shared-cache architectures for both OLTP and DSS workloads. We show that the shared-cache architecture allows the DBMS to choose from a superset of the parallel execution strategies that can be used in a shared nothing system. Shared cache uses SMP-like global buffer cache coherence protocol for OLTP transactions and shared-nothing-like partitioned parallelism for DSS workloads. We then explain the innovations present in Oracle 9i RAC to implement a shared-cache database using commodity hardware components. Finally, we explore future directions to further improve the shared-cache architecture on commodity clusters.
Dynamic analysis of load sense steering hydraulic system priority valve (2011)

Priority valve is one of the key components of hydraulic steering-system and its performance decides the stability of steering-system. Taking the YXL priority valve as an example, Basing on analytical method and SIMULINK, establish the priority valve dynamic mathematical model and simulation model and analyze the laws and the influences of the key parameters such as the steering wheel rotation speed, steering system load quality, flow gain, pressure-flow coefficient and steering cylinders effective area on dynamic response characteristics with the simulation analysis. This part of work lays the solid foundation for optimization design of priority valve.
Real-time monitoring system of RF near-field distribution images on the basis of 64-channel parallel electro-optic data acquisition (2005)

Described in this paper is a system for the real-time image monitoring of electromagnetic near-field distributions over devices and circuits at a specific radio frequency (RF), which is the first to the best of our knowledge. It is based on a 64-channel parallel electro-optic heterodyne detection scheme, in which arrays of photodiodes and mixers allow simultaneous acquisition of 8 × 8pixel data. Its highest frame rate of 10Hz enables even a motion picture display of RF near-field images. It has been applied to a patch antenna and a moving RF emitter for performance demonstration.
Asymmetric s-curve trajectory planning for robot point-to-point motion (2009)

In this paper, we develop an asymmetric s-curve profile method with jerk bounded to obtain high-precision motion and reduce the residual vibration. All possible instances for asymmetric s-curve profile planning are analyzed. The algorithm and its implementation are proposed with a direct and complete method. Simulation results are presented to verify the effectiveness and reliability of the proposed approach.
Effect of Peritoneal Trauma on Peritoneal Fibrinolytic Activity and Intraperitoneal Adhesion Formation (1981)

Changes in peritoneal fibrinolytic activity have been studied following four types of insult which may occur in the course of abdominal surgery, namely (1) creation of peritoneal defects, (2) free peritoneal grafting, (3) diathermy coagulation and (4) peritoneal ischaemia. Free peritoneal grafting, diathermy, and peritoneal ischaemia are associated with a significant depression of fibrinolytic activity compared with unsutured peritoneal defects and are also associated with a significant increase in adhesion formation. Fibrinolytic activity is not maximally depressed at the time of operation and further depression occurs during the first 24 h post-operatively. Depression of fibrinolytic activity may be a significant factor in the aetiology of intraperitoneal adhesions.
Dynamic and Distributed Load Balancing Scheme in Multi-gateway Based 6LoWPAN (2014)

In 6LoWPAN, all the nodes access the Internet through the gateways, which are on the border to legacy IP networks and handle ingress and egress data traffic. A gateway as the traffic center may easily become the congestion-concentrated point so that causes reliability problems and performance degradation. Gateway bottleneck is the dominant reason for network capacity and throughput constriction, since all traffic should pass through the GW. Even though we apply multiple gateways, the network capacity and network throughput cannot increase linearly with the number of gateways because of the imbalance of traffic load among gateways. The load balancing between gateways is a key technology to reduce the traffic congestion thereby enlarging the network capacity, satisfying the capacity fairness among nodes, and removing network reliability issue. In this paper, we propose a dynamic and distributed load balancing scheme to achieve a global load fairness, motivated by water flow behavior, named MLEq (Multi-gateway Load Balancing Scheme for Equilibrium). We implement our load balancing scheme in ns-2 simulator and it is verified by extensive simulations. As a result, we show that throughput can be improved by the proposed scheme and the load can be fairly distributed over LoWPAN. More importantly, the results show that network capacity and throughput can increase linearly with the number of gateways.
Involvement of the proteasome and antizyme in ornithine decarboxylase degradation by a reticulocyte lysate (1993)

Ornithine decarboxylase (ODC) degradation in a freshly prepared reticulocyte lysate was examined. Immunodepletion of proteasomes from the reticulocyte lysate resulted in almost complete loss of ODC degradation. In contrast with the previously reported degradation in extracts of hepatoma tissue-culture (HTC) and Chinese-hamster ovary (CHO) cells or that by the purified 26 S proteasome, efficient degradation of ODC was observed in the lysate without exogenous antizyme, an ODC protein inhibitor induced by polyamines, owing to the presence of a significant amount of antizyme in the lysate. The degradation of ODC in the lysate was strongly suppressed on inactivation of antizyme in the lysate with antizyme inhibitor, a protein which binds to the antizyme and releases ODC from the ODC-antizyme complex. Thus the main pathway for ODC degradation in a reticulocyte lysate was essentially the same as that characterized previously in extracts of HTC and CHO cells, namely an ATP- and antizyme-dependent 26 S proteasome-catalysed pathway that is presumed to be responsible for ODC degradation in whole cells.
In Situ Ellipsometric Observations of the Growth of Silicon Thin Films from Fluorinated Precursors, SiF<sub>n</sub>H<sub>m</sub> (n+m≤3) (1993)

The growth of silicon thin films fabricated from fluorinated precursors SiF n H m ( m + n ≤3), was investigated for the first time by in situ ellipsometric observation. Specific dependencies were recognized of the ellipsometric trajectories in the (Ψ, Δ) plane on chemical species used as the precursors. Under certain film preparation condition wherein the structures formed depend greatly on parameters such as the substrate temperature and the substrate material, the film structure was altered from amorphous to polycrystalline or epitaxial. The ordering of the structure was gradually improved with an increase in the thickness. Under the other condition, µ-crystalline films with columnar texture were fabricated independently of substrate temperature or material.
The Development of Advanced Optical Fibers for Long-Wave Infrared Transmission (2013)

Long-wave infrared fibers are used in an increasing number of applications ranging from thermal imaging to bio-sensing. However, the design of optical fiber with low-loss in the far-infrared requires a combination of properties including good rheological characteristics for fiber drawing and low phonon energy for wide optical transparency, which are often mutually exclusive and can only be achieved through fine materials engineering. This paper presents strategies for obtaining low loss fibers in the far-infrared based on telluride glasses. The composition of the glasses is systematically investigated to obtained fibers with minimal losses. The fiber attenuation is shown to depend strongly on extrinsic impurity but also on intrinsic charge carrier populations in these low band-gap amorphous semiconductor materials.
Quantigraphic Imaging: Estimating the camera response and exposures from differently exposed images (2005)

Multiple differently exposed pictures of the same subject matter arise naturally whenever a video camera having automatic exposure captures multiple frames of video with the same subject matter appearing in regions of overlap between at least some of the successive video frames. Almost all cameras have some kind of automatic exposure feature. Generally automatic exposure is center weighted, so that when a light object falls in the center of the frame the exposure is automatically decreased, whereas the exposure is automatically increased when the camera swings around to point at a darker object. In this paper, it is assumed that the spatial (e.g. projective) coordinate transformation between successive frames of the sequence is known (or equivalently that it is the identity), and the contribution of the paper is an efficient way to estimate the tonal relationship between successive frames of the sequence. In particular methods are proposed to simultaneously estimate the unknown camera response function, as well as the set of unknown relative exposure changes among images, up to a single unknown scalar constant. The method comprises a succession of guesses each of which is a refinement of the previous. The first guess is often sufficient, so that no initial solution needs to be provided by the user. Each subsequent guess is a least squares solution so that no computationally expensive optimization is required. Since the method makes use of all the data, it is extremely immune to noise. The method is tested against state-of-the art laboratory measurement instruments to confirm the accuracy of the results.