gebhart/patrepeval huggingface dataset:
Electrochemical Water Oxidation Catalysis Beginning with Co(II) Polyoxometalates: The Case of the Precatalyst Co<sub>4</sub>V<sub>2</sub>W<sub>18</sub>O<sub>68</sub><sup>10–</sup> (2016)

The question is addressed of whether the cobalt polyoxometalate (Co-POM) precatalyst Co4V2W18O6810– (hereafter Co4V2W18) is a stable, homogeneous water oxidation catalyst under electrochemically driven conditions and in 0.1 M pH 5.8 and 8.0 NaPi buffer as well as pH 9.0 sodium borate (NaB) buffer. This question is of considerable interest since Co4V2W18 has been reported to be highly stable and a 200-fold faster water oxidation catalyst than its P congener Co4P2W18O6810– (hereafter Co4V2W18), for reasons that were not specified. The nature of the true water oxidation catalyst with Co4V2W18 as the starting material is of further fundamental interest because a recent report reveals that the 51V NMR peak at ca. −507 ppm assigned by others to Co4V2W18 and used to argue for its solution stability is, instead, correctly assigned to the highly stable cis-V2W4O194–, in turn raising the question of the true stability of Co4V2W18 under water oxidation catalysis conditions. A battery of physical methods is used to address the questions of the stability and true water oxidation catalyst with Co4V2W18 as the precatalyst: 31P line-broadening detection of Co(II) present in solution from leaching or as a counterion impurity; a check of those Co(II) concentration results by the second method of cathodic stripping; the O2 yield (and, hence, Faradaic efficiency) of electrocatalytic water oxidation; electrochemical, SEM, EDX, and XPS characterization of CoOx films produced on the electrode; and multiple controls and other experiments designed to test alternative hypotheses that might explain the observed results. The collective evidence provides a compelling case that Co(II) derived from Co4V2W18 forms a CoOx film on the electrode which, in turn, carries all the observed, electrochemically driven water-oxidation catalysis current within experimental error. A list of seven main findings is provided as a summary.
Production of D-Alanine by <i>Corynebacterium fascians</i> (1973)

A strain identified as Corynebacterium fascians was found to accumulate extracellular D-alanine from glycerol. Cultural conditions for the accumulation of D-alanine were investigated and, as a result, a yield of 7 g of D-alanine per liter was obtained after a 96-h incubation in a medium containing 5% glycerol, 4% (NH(4))(2)HPO(4), and 0.3% corn steep liquor. Optical purity of D-alanine was dependent upon the concentration of corn steep liquor. At the optimal condition, almost optically pure D-alanine was formed and readily isolated (5 g/liter) from the fermentation broth. The product was not contaminated with any detectable amount of other amino acids, except for glycine which was present at a concentration of less than 1 percent.
Radioimmunoassay of hair for determining opiate-abuse histories. (1979)

Heroin and morphine metabolites can be detected in hair with the use of commercially available radioimmunoassay reagents and with minor sample preparation. Hair samples obtained from morphine-treated mice and heroin users contained nanogram levels of the drug per milligram of hair (single human hair). The results of the hair analyses for all subjects admitting the use of heroin were positive, whereas the results of only 30% of thin-layer chromatographic urinanalyses of these same subjects were positive. In addition, differences in drug concentration for sections of hair near the scalp and near the distal end correlated with the length of time the drug had been used. These results exemplify the potential advantages of the use of hair analysis over urine and serum analyses in terms of accessibility, sample stability, and long-term retention of information.
Increasing believability: agents that justify their actions (2002)

Creating believable agents that can communicate and collaborate with the player is one of the big challenges in developing computer games. We propose an architecture that uses a logic-based truth maintenance system coupled with a rule engine to create articulate agents capable of having conversations with the player. Our preliminary investigation shows that this framework can be used to develop a new style of computer game where the player actively learns through interacting with the computer characters.
Performance enhancement for TCP/IP on a satellite channel (2002)

Worldwide usage of the Internet is currently growing at an exponential rate, resulting in a dramatic increase in the demand for the transmission of Internet data via satellite. The TCP/IP protocol suite, which forms the basis of the Internet, performs sub-optimally when confronted with a geostationary satellite link. This may result in poor performance as seen by an interactive user and/or inefficient utilization of precious satellite resources. In response to military needs, MIT Lincoln Laboratory has developed the wireless IP suite enhancer (WISE) which dramatically improves the performance of TCP/IP when it is extended via a satellite link. Tests of a prototype unit conducted on the satellite networking test-bed at Lincoln Laboratory show that WISE yields nearly optimal utilization of the satellite link.
An algorithm for approximate closest-point queries (1994)

This paper gives an algorithm for approximately solving the post office problem: given n points (called sites) in d dimensions, build a data structure so that, given a query point q, a closest site to q can be found quickly. The algorithm is also given a relative error bound ε, and depends on a ratio ρ, which is no more than the ratio of the distance between the farthest pair of sites to the distance between the closest pair of sites. The algorithm builds a data structure of size O(nη)O(1/ε)(d−1)/2 in time O(n2η)O(1/ε)(d−1). Here η=log(ρ/ε). With this data structure, a site is returned whose distance to a query point q is within 1+ε of the distance of the closest site. A query needs O(logn)O(1/ε)(d−1)/2 time, with high probability.
A microsensor for direct measurement of O<sub>2</sub>partial pressure within plant tissues3 (1996)

Widespread use of O2 microsensors to measure O2 partial pressure (pO2) in plant tissues has been limited in part because of difficulty of construction and other technical obstacles. By modifying published techniques, an O2 microsensor was constructed that combined the advantages of Clark-type microsensors with less complicated construction techniques. The specifications and some performance characteristics of the microsensor are: tip diameter 1–5 μm; sensitivity 7.5–25 pA kPa−1; negligible stir-induced current; response time 540 ms. The microsensor can be used in air or solution, and each sensor can be used for several experiments. The sensitivity of the microsensor was unchanged during measurements over the physiological range of pO2 in intact, growing maize (Zea mays L.) primary roots, and was thus unaffected by cellular fluids and turgor pressure. Use of the microsensor to compare pO2 profiles in vermiculite- and solution-grown roots is described. The O2 microsensor could find application in studies in which information on tissue pO2 is needed, but for which conventional O2 probes are too large.
Rad51 gain-of-function mutants that exhibit high affinity DNA binding cause DNA damage sensitivity in the absence of Srs2 (2008)

We previously identified several rad51 gain-of-function alleles that partially suppress the requirement for RAD55 and RAD57 in DNA repair. To gain further insight into the mechanism of action of these alleles, we compared the activities of Rad51-V328A, Rad51-P339S and Rad51-I345T with wild-type Rad51, for DNA binding, filament stability, strand exchange and interaction with the antirecombinase helicase, Srs2. These alleles were chosen because they show the highest activity in suppression of ionizing radiation sensitivity of the rad57 mutant, and Val 328 and Ile 345 are conserved in the human Rad51 protein. All three mutant proteins exhibited higher affinity for single-stranded DNA (ssDNA) and showed more robust strand exchange activity with oligonucleotide substrates than wild-type Rad51, with the Rad51-I345T and Rad51-V328A proteins displaying higher activity than Rad51-P339S. However, the Srs2 antirecombinase was able to disrupt Rad51-ssDNA complexes formed with all the mutant proteins. In vivo, the rad51-I345T mutant strain exhibited high resistance to methyl methane sulfonate that was dependent on functional SRS2. These results suggest the Srs2 translocase is able to disrupt Rad51-ssDNA complexes at stalled replication forks, but in the absence of Srs2 the enhanced DNA binding of the Rad51-I345T protein is detrimental to cell survival.
Specification and Simulation of Statistical Query Algorithms for Efficiency and Noise Tolerance (1998)

A recent innovation in computational learning theory is the statistical query (SQ) model. The advantage of specifying learning algorithms in this model is that SQ algorithms can be simulated in the probably approximately correct (PAC) model, both in the absenceandin the presence of noise. However, simulations of SQ algorithms in the PAC model have non-optimal time and sample complexities. In this paper, we introduce a new method for specifying statistical query algorithms based on a type ofrelative errorand provide simulations in the noise-free and noise-tolerant PAC models which yield more efficient algorithms. Requests for estimates of statistics in this new model take the following form: “Return an estimate of the statistic within a 1±μfactor, or return ⊥, promising that the statistic is less thanθ.” In addition to showing that this is a very natural language for specifying learning algorithms, we also show that this new specification is polynomially equivalent to standard SQ, and thus, known learnability and hardness results for statistical query learning are preserved. We then give highly efficient PAC simulations of relative error SQ algorithms. We show that the learning algorithms obtained by simulating efficient relative error SQ algorithms both in the absence of noise and in the presence of malicious noise have roughly optimal sample complexity. We also show that the simulation of efficient relative error SQ algorithms in the presence of classification noise yields learning algorithms at least as efficient as those obtained through standard methods, and in some cases improved, roughly optimal results are achieved. The sample complexities for all of these simulations are based on thedνmetric, which is a type of relative error metric useful for quantities which are small or even zero. We show that uniform convergence with respect to thedνmetric yields “uniform convergence” with respect to (μ, θ) accuracy. Finally, while we show that manyspecificlearning algorithms can be written as highly efficient relative error SQ algorithms, we also show, in fact, thatallSQ algorithms can be written efficiently by proving general upper bounds on the complexity of (μ, θ) queries as a function of the accuracy parameterε. As a consequence of this result, we give general upper bounds on the complexity of learning algorithms achieved through the use of relative error SQ algorithms and the simulations described above.
Roaming Real-Time Applications - Mobility Services in IPv6 Networks (2004)

Emerging mobility standards within the next generation Internet Protocol, IPv6, promise to continuously operate devices roaming between IP networks. Associated with the paradigm of ubiquitous computing and communication, network technology is on the spot to deliver voice and videoconferencing as a standard internet solution. However, current roaming procedures are too slow, to remain seamless for real-time applications. Multicast mobility still waits for a convincing design. This paper investigates the temporal behaviour of mobile IPv6 with dedicated focus on topological impacts. Extending the hierarchical mobile IPv6 approach we suggest protocol improvements for a continuous handover, which may serve bidirectional multicast communication, as well. Along this line a multicast mobility concept is introduced as a service for clients and sources, as they are of dedicated importance in multipoint conferencing applications. The mechanisms introduced do not rely on assumptions of any specific multicast routing protocol in use.
Myringotomy Made by CO<sub>2</sub>Laser An Alternative to the Ventilation Tube?:An Experimental Study (1984)

In order to examine whether a myringotomy made with a CO2-laser might be alternative to a ventilation tube, a perforation was made in the upper rear quadrant bilaterally, of 22 rats. The laser-made perforations showed a delayed healing pattern, about twice the closing time of a similar-sized perforation made with a myringotomy lancet. Serous effusion was constantly observed in the attic space during the first 9 days but only in one ear was there actual discharge through the perforation. The size of the perforation started to diminish when the hyperplastic keratinizing squamous epithelium reached the perforation border.
Chemical dissolution of a porous medium by a reactive fluid (1987)

Chemical dissolution of a two-dimensional porous medium by a reactive fluid which produces fractal patterns is studied. A new model is proposed that introduces a cumulative erosion process which broadens the branches of the cluster and gives structures very similar to the experimental ones. Diffusion-limited aggregation is a limiting case of this model. An interpretation of the evolution of the injection pressure with time which yields the fractal dimension is also presented, and agrees with the experimental results.
Rheological Characterization of Hydroxypropylcellulose Gels (1999)

The present paper describes the rheological properties of hydroxypropylcellulose (HPC) gels formulated in propylene glycol (PG), water, ethanol, and mixtures of these components. The effects of molecular weight, polymer concentration, and solvent composition on the apparent viscosity and flow characteristics have been studied by continuous shear rheometry. The HPC gels are shear thinning and do not exhibit significant yield or hysteresis in their rheograms. The apparent viscosity increases with increasing molecular weight and concentration of the polymer, as expected. Although not so pronounced at lower concentrations (< or = 1.5%), HPC gels tend to become increasingly non-Newtonian with increasing molecular weight at higher polymer concentrations (3%). A mathematical model has been proposed for the prediction of viscosities of HPC gels. There exists a high degree of dependence on molecular interactions between various solvent molecules in the prediction of mixture viscosities in ternary systems. The effects of solvent composition on the viscoelastic behavior of these gels have also been examined by dynamic mechanical analysis. The HPC gels are highly viscoelastic and exhibit greater degrees of elasticity with increased PG content in ternary solvent mixtures with water and ethanol. The study also suggests that dynamic mechanical analysis could prove to be a useful tool in the determination of zero-shear viscosities, viscosities that are representative of most realistic situations.
Beta 1 integrin-dependent and -independent polymerization of fibronectin. (1996)

The mouse cell line GD25, which lacks expression of the beta 1 family of integrin heterodimers due to disruption of the beta 1 integrin subunit gene, was used for expression of full-length cDNA coding for splice variant A of the mouse beta 1 integrin subunit. In a stably transformed clone (GD25-beta 1A), the expressed protein was found to form functional heterodimeric receptors together with the subunits alpha 3, alpha 5, and alpha 6. Both GD25 and GD25-beta 1A attached to fibronectin and formed focal contacts which contained alpha v beta 3, but no detectable alpha 5 beta 1A. The presence of GRGDS peptide allowed alpha 5 beta 1A to locate to focal contacts of GD25-beta 1A cultured on fibronectin, while the beta 1-null GD25 cells were unable to attach under these conditions. Affinity chromatography revealed that alpha 5 beta 1A and alpha v beta 3 could bind to a large cell-binding fragment of fibronectin. alpha 5 beta 1A strongly promoted polymerization of fibronectin into a fibrillar network on top of the cells. Whereas little alpha v beta 3 was colocalized with the fibronectin fibrils in GD25-beta 1A cells, this integrin was able to support fibronectin fibril polymerization in GD25 cells. However, the alpha v beta 3-induced polymerization was less efficient and occurred mainly in dense cultures of the GD25 cells. Thus, while both alpha 5 beta 1A and alpha v beta 3 are able to support adhesion to fibronectin, alpha v beta 3 dominates in the formation of focal contacts, and alpha 5 beta 1A has a prime function in fibronectin matrix assembly. This is the first report on fibronectin matrix assembly in the absence of beta 1 integrins.
Retinoic acid inhibits chondrogenesis of mesenchymal cells by sustaining expression of N‐cadherin and its associated proteins (2003)

Retinoic acid (RA) is a well-known regulator of chondrocyte phenotype. RA inhibits chondrogenic differentiation of mesenchymal cells and also causes loss of differentiated chondrocyte phenotype. The present study investigated the mechanisms underlying RA regulation of chondrogenesis. RA treatment in chondrifying mesenchymal cells did not affect precartilage condensation, but blocked progression from precartilage condensation to cartilage nodule formation. This inhibitory effect of RA was independent of protein kinase C and extracellular signal-regulated protein kinase, which are positive and negative regulators of cartilage nodule formation, respectively. The progression from precartilage condensation to cartilage nodule requires downregulation of N-cadherin expression. However, RA treatment caused sustained expression of N-cadherin and its associated proteins including alpha- and beta-catenin suggesting that modulation of expression of these molecules is associated with RA-induced inhibition of chondrogenesis. This hypothesis was supported by the observation that disruption of the actin cytoskeleton by cytochalasin D (CD) blocks RA-induced sustained expression of cell adhesion molecules and overcomes RA-induced inhibition of chondrogenesis. Taken together, our results suggest RA inhibits chondrogenesis by stabilizing cell-to-cell interactions at the post-precartilage condensation stage.
Anticardiolipin antibodies in rheumatoid arthritis: their relation to rheumatoid nodules and cutaneous vascular manifestations (1994)

One hundred and seventy-three consecutive patients with rheumatoid arthritis were examined for the presence of anticardiolipin antibodies (ACA), and for the clinical relevance and the relation of these antibodies to skin manifestations. Abnormally elevated IgG- and/or IgM-ACA levels were detected by an enzyme-linked immunosorbent assay in the sera of 55 (32%) patients. There was no statistical evidence of an association between ACA and a history of thrombosis in these patients. However, ACA were statistically significantly linked to the presence of rheumatoid nodules, which were found in 36 (21%) patients. In three patients, ACA were associated with vascular manifestations, including livedo reticularis, thrombophlebitis, and leucocytoclastic vasculitis. Our findings suggest that, although a subset of ACA may be linked to cutaneous vascular conditions, the major fraction of ACA in rheumatoid arthritis may have a different specificity than in other diseases, in which ACA are often linked to thrombotic events.
Transient Impact of Prolonged Versus Repetitive Stretch on Hand Motor Control in Chronic Stroke (2011)

Repetitive PROM stretching exhibited trends to be more effective than prolonged stretching for improving hand motor control. Although the results were highly variable and the effects are undoubtedly transient, an extended period of repetitive PROM stretching may prove advantageous prior to hand therapy sessions to maximize treatment.
Antisense Inhibition of Cyclin D1 in Human Head and Neck Squamous Cell Carcinoma (2000)

These studies provided evidence that overexpression of cyclin D1 may play an important role in growth rates and biological behavior of human head and neck cancer. Additionally, expression of cyclin D1 may make human head and neck cancer cells resistant to platinum-based chemotherapeutic approaches. The ability to suppress the malignant phenotype by down-regulating cyclin D1 expression may provide a new gene therapy approach for patients with head and neck cancer.
Cardiac Disease in Chronic Obstructive Pulmonary Disease (2008)

The cardiac manifestations of chronic obstructive pulmonary disease (COPD) are numerous. Impairments of right ventricular dysfunction and pulmonary vascular disease are well known to complicate the clinical course of COPD and correlate inversely with survival. The pathogenesis of pulmonary vascular disease in COPD is likely multifactorial and related to alterations in gas exchange and vascular biology, as well as structural changes of the pulmonary vasculature and mechanical factors. Several modalities currently exist for the assessment of pulmonary vascular disease in COPD, but right heart catheterization remains the gold standard. Although no specific therapy other than oxygen has been generally accepted for the treatment of pulmonary hypertension in this population, there has been renewed interest in specific pulmonary vasodilators. The coexistence of COPD and coronary artery disease occurs frequently. This association is likely related to shared risk factors as well as similar pathogenic mechanisms, such as systemic inflammation. Management strategies for the care of patients with COPD and coronary artery disease are similar to those without COPD, but care must be given to address their respiratory limitations. Arrhythmias occur frequently in patients with COPD, but are rarely fatal and can generally be treated medically. Use of beta-blockers in the management of cardiac disease, while a theoretical concern in patients with increased airway resistance, is generally safe with the use of cardioselective agents.
Changes in surface roughness and color stability of two composites caused by different bleaching agents (2012)

The objective of this study was to evaluate the effect of two bleaching agents (10% and 35% hydrogen peroxide) on the color stability and surface roughness of two composites, one nanohybrid and one nanoparticle. Specimens were polished, aged, stained, bleached and polished again. The action of the bleaching agents on the composites was analyzed using a profilometer (surface roughness) and a spectrophotometer (color stability). The effect of polishing the composites on the surface roughness and the resumption of the composite color was also evaluated. The results were analyzed statistically by ANOVA and Tukey's test at 5% significance level. The analysis indicated that the nanohybrid composite was more affected by staining. The bleaching agents were not able to promote bleaching of either composite over the evaluation period. Surface polishing returned nanohybrid composite to its original color condition, which did not occur for the nanoparticle composite. Additionally, polishing did not return the surface roughness of either composite to its original value. It may be concluded that polishing surface after bleaching should not be the treatment of choice, as it was not possible to reverse the roughness of the composites to their original values, suggesting that a more extensive and irreversible degradation might have occurred.