gebhart/patrepeval huggingface dataset:
Dual‐functional catalysis for ethylene polymerization to branched polyethylene. II. Kinetics of ethylene polymerization with a mixed homogeneous–heterogeneous Ziegler–Natta catalyst system (1986)

Abstract The previous paper in this series described several catalytic systems which can be used for simultaneous ethylene dimerization to 1‐butene and copolymerization of the in situ ‐formed olefin with ethylene to form branched polyethylene. Such catalytic systems allow the synthesis of linear low‐density polyethylene from a single monomer source. This article presents a more detailed description of one of the dual‐functional catalyst systems studied, a mixed homogeneous–heterogeneous Ziegler–Natta catalyst, Al(C 2 H 2 ) 3 –Ti(Oi‐C 3 H 7 ) 4 –TiCl 4 /MgCl 2 /polyethylene, at 90°C. Discussed are kinetics of ethylene dimerization with the soluble component, Al(C 2 H 5 ) 3 –Ti(Oi–C 3 H 7 ) 4 , and the effects of aluminum alkoxides on the system. Addition of the ethylene dimerization catalyst to the solid component, Al(C 2 H 5 ) 3 –TiCl 4 /MgCl 2 /polyethylene, results in a partial decrease in polymerization activity. Some of the decrease can be attributed to the presence of 1‐butene in the reaction medium. Measurement of the reactivity ratio k EE / k EB for two catalytic systems, the solid component and the title dual‐functional catalyst, demonstrated that the presence of the dimerization component results in a twofold increase in the reactivity ratio, from 20 to ca. 40.
Mexico's preschools : coverage, equity and impact (1998)

After a brief description of the role of preschool education in child development, the study reviews the preschool system in Mexico and examines the pedagogical function, the family need for substitute childcare, and the social concern for equity. Findings indicate that coverage is high, though the system is costly with very little impact on school readiness, or on mothers' decision to work. These are legitimate and intertwined issues, though the extent to which each one operates should play a role in policy formulation. The study provides a cautionary note, pointing out inadequate existing data sources. Recommendations include modifications in the preschool system and ways to develop better evaluation data.
Magnetic Resonance in Chalk Horizontal Well Logged With LWD (2010)

Summary This paper describes geological and petrophysical evaluation of a new structure of a mature field to evaluate the reservoir potential in unproduced reservoir zones. The well was drilled in a carbonate with variations in rock quality and with minor subfaulting occurring. Gamma ray (GR), resistivity, density, neutron, and image services were used in the horizontal part of the well in addition to magnetic resonance (MR). To achieve the best possible real-time wellbore placement, reservoir navigation and continuous follow-up on the horizontal log interpretation were performed during drilling. For the first time, a low-gradient-MR-while-drilling technology was deployed in a virgin carbonate horizontal well on the Norwegian Continental Shelf. The MR service was run to obtain porosities (including partitioning of movable and bound fluids), hydrocarbon (HC) saturations, and permeability estimates. Fluid saturations based on traditional methods and the MR were evaluated and compared by core data, enhancing the understanding of the measurement and the reservoir. For post-processing, the MR data were integrated and interpreted together with the other measurements performed in the well, delivering an accurate and consistent reservoir description. The first part of the horizontal part of the well was drilled with conductive drilling fluid and the latter part with nonconductive drilling fluid. Laboratory measurements for the two mud filtrates were performed to understand the influence of the two different drilling-fluid types on the MR measurements. In the absence of water-based mudfiltrate invasion, the MR data show good agreement with saturations from core, confirming the quality and reliability of the MR data. Comparison of the MR T2 distributions and volumetrics with image data indicates that even fine variations in rock quality and lithology are reliably resolved by the MR data. Before logging, old core data were used to refine the constants used in the Timur-Coates MR permeability equation, which quantitatively tracks changes in reservoir quality. The values were calibrated when Timur-Coates constants were derived from the well's core plugs.
Retinal polarization effects (1982)

Retinal photographs taken with crossed polarizers in the input and recording light paths show a cross or brush pattern overlying the macula. Experiments were done indicating that this pattern is due to the birefringence in cone-photoreceptor outer segments. Haidinger’s brushes are also attributed to cone outer segments, but the effect is due to a combination of the dispersion in the birefringence and the dichroism of the outer segments. The objective, polarized-light retinal pattern is shown to be a useful clinical tool for diagnosing diseases affecting the macula.
Submillimeter high-resolution FT spectrometer for atmospheric studies (1984)

The rationale, design, and performance of a high-resolution Fourier transform spectrometer are discussed. The instrument was employed in the measurement of stratospheric emissionin the 7–90-cm−1 spectral interval with a 0.0033-cm−1 resolution (unapodized) from a balloon-borne platform at ~40-km altitude.
K2P channel gating mechanisms revealed by structures of TREK-2 and a complex with Prozac (2015)

TREK-2 (KCNK10/K2P10), a two-pore domain potassium (K2P) channel, is gated by multiple stimuli such as stretch, fatty acids, and pH and by several drugs. However, the mechanisms that control channel gating are unclear. Here we present crystal structures of the human TREK-2 channel (up to 3.4 angstrom resolution) in two conformations and in complex with norfluoxetine, the active metabolite of fluoxetine (Prozac) and a state-dependent blocker of TREK channels. Norfluoxetine binds within intramembrane fenestrations found in only one of these two conformations. Channel activation by arachidonic acid and mechanical stretch involves conversion between these states through movement of the pore-lining helices. These results provide an explanation for TREK channel mechanosensitivity, regulation by diverse stimuli, and possible off-target effects of the serotonin reuptake inhibitor Prozac.
Increase on Siemens Reactor Throughput by Tailoring Temperature Profile of Polysilicon Rods (2007)

Siemens process productivity can be limited by non homogeneous temperature profile in polysilicon rods. To overcome this limitation high frequency current sources have been proposed. An analysis is presented which, based on electromagnetic and heat transfer theory, studies temperature and current density profiles within the rods. Two linked differential equations have been numerically solved by use of non-linear methods. The solution of these equations shows that by means of an increase in current frequency, skin effect takes place, heat generation in the inner part of the rod is decreased and therefore temperature homogeneity increases. The effect of high frequency current sources in the rod stability is also analyzed, and it can be derived that resonance problems could appear.
Expression of basal cell keratins in human prostate cancer metastases and cell lines (2001)

Within normal human prostate epithelium, basal and luminal cells can be discriminated by their expression of keratins (K). While basal cells express K5/14, luminal cells show expression of K8/18 and an intermediate cell population can be identified by co-expression of K5/18. Prostate cancer is predominantly composed of luminal and neuroendocrine cells, while a minority of cells have a basal phenotype. In order to distinguish between basal and intermediate cells, and to assess the effects of androgen deprivation on prostate cancer, 56 human prostate cancer metastases and three cancer cell lines were characterized using antibodies to K5, K14, K18, and the neuroendocrine marker chromogranin A (ChA). The staining was performed on paraffin tissue and visualized by the avidin-biotin-peroxidase complex method. Protein expression was quantified as the number of positive cells in 20 high power fields (HPF; 400x). Keratin expression in the prostate cancer cell lines LNCaP, DU145, and PC3 was analysed by immunofluorescence with triple staining and confocal laser scanning microscopy. Prostate cancer metastases were consistently positive for K18 and negative for K14, irrespective of hormonal therapy. K5 expression was displayed in 28.9% of the tumours without treatment, in 75% after androgen deprivation, and in 57.1% of hormone-escaped prostate carcinomas. After androgen deprivation, the number of K5-expressing cells increased significantly. While androgen-dependent prostate cancer showed a median of 0 cells/20 HPF (range 0-50), regressed tumours displayed 22.5 (range 0-65) and hormone-escaped tumours 7.5 (range 0-361) positive cells/20 HPF. Expression of ChA was observed in 47.4% of the androgen-dependent tumours. The number of neuroendocrine cells was not significantly affected in regressed or hormone-escaped disease. The androgen-dependent cell line LNCaP stained for K18, while the androgen-independent lines DU145 and PC3 both expressed K5 and 18. Expression of K5 in the absence of K14 identifies the existence of an intermediate cell population in prostate carcinoma. Accumulation of intermediate cells in regressed and hormone-escaped prostate cancer indicates that for their survival, these cells are androgen-independent.
2-HALOVINYL ARYL SULFONES: NEW COUPLING REAGENTS FOR CARBOXAMIDE FORMATION<sup>1</sup> (1983)

Abstract E-2-Chlorovinyl p-nitrophenyl sulfone 6 and 2-bromo-2-trifluoromethylvinyl phenyl sulfone 7a reacted with carboxylic acids in the presence of a molar equiv of Et3N affording the corresponding 2-acyloxyvinyl sulfones 8, 11, 17, 18, 22, 25, 28 and 29. The latter, on treatment with amines, gave amides 9, 13, 19, 23 and 26 and peptides 30 and 32. These reagents 6 and 7a were also used for the formation of N-methylanilides 13d, 13e, 19d, 23 and 26. Particularly, 6 was successfully used for synthesis of a macrocyclic lactam 23 involving a N-methylanilide moiety. The amidation reactions proceeded under essentially neutral conditions. Therefore, base-sensitive β-hydroxycarboxy-N-methylanilides such as 26, whose structural unit was involved in maytansine 5, could be prepared by the present method. The reagent 6 was also effective for the preparation of peptides such as Val-N-MeVal derivatives (e.g. 32), which were difficult to prepare by other methods.
Intravitreal Treatment of Cytomegalovirus Retinitis and the Need for Controlled Release Systems (1998)

As a topic of considerable contemporary interest, cytomegalovirus (CMV) retinitis is briefly reviewed and its relevance to the acquired immunodeficiency syndrome (AIDS) has been highlighted. Traditional therapies for halting the progression of CMV retinitis, which culminates in loss of eyesight, are outlined, and limitations to these therapies are analyzed. The local route for controlled drug delivery through intravitreal application is advocated as the choice strategy. Among the intravitreal controlled release systems that show some promise are (a) non-absorbable implants for administering ganciclovir; and (b) intravitreal liposomal formulations of antiviral agents. The latter approach was cited among the emerging trends along with the use of minimally invasive injectable gel-forming liquids for the controlled release of highly potent, but considerably toxic drugs such as cidofovir.
Topology optimization of multi-material for the heat conduction problem based on the level set method (2010)

This article presents a numerical approach of topology optimization with multiple materials for the heat conduction problem. The multiphase level set model is used to implicitly describe the geometric boundaries of material regions with different conductivities. The model of multi-material representation has no emergence of the intermediate density. The optimization objective is to construct the optimal heat conductive paths which improve the efficiency of heat transfer. The dissipation of thermal transport potential capacity is taken as the objective function. The sensitivity analysis is implemented by the adjoint variable method, which is the foundation of constructing the velocity field of the level set equation. The optimal result is gradually realized by the evolution of multi-material boundaries, and the topological changes are naturally handled during the optimization process. Finally, the numerical examples are presented to demonstrate the feasibility and validity of the proposed method for topology optimization of the heat conduction problem.
Binaural reproduction of Spatially Squeezed Surround Audio (2008)

Spatially Squeezed Surround Audio Coding (S <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> AC) has been previously proposed as an efficient approach to multi-channel spatial audio coding with stereo/mono backward compatibility. This paper presents a binaural reproduction scheme that exploits source localisation information in the S <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> AC squeezed soundfield or S <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> AC cues to simulate surround audio scene over headphones. The approach utilises interpolated HRTFs to bring the S <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> AC advantages of accurate, localised sound sources to stereo headphone systems. The integration of the HRTF approach to reproduction also exploits human localisation ability to reduce interpolation complexity. Subjective experiments demonstrate that accurate localisation is achieved from binaural, interpolated HRTF playback when compared to multi-channel playback.
One-pot synthesis of lignin-stabilised platinum and palladium nanoparticles and their catalytic behaviour in oxidation and reduction reactions (2012)

A one-pot green method to synthesise Pt and Pd nanoparticles is reported. Two natural aromatic polymers, lignin and fulvic acid, were used as both reducing and stabilising agents at moderate temperature (80 °C) in water and under aerobic conditions. Full characterisation was performed using TEM, UV-vis, XRD, 195Pt and 1H NMR, FT-IR and GC-MS techniques. In the TEM images, we observed spherical nanoparticles of diameters in the range of 16 nm to 20 nm, in the case of Pd, and smaller ones of not so well defined shapes for Pt. GC-MS of the organic fractions formed during the preparation of the nanoparticles showed defined amounts of vanillin, a well known degradation product of these polymers. This finding indicates that the active participation of lignins and fulvic acids in the metal reduction step. The catalytic activity of the nanoparticles was tested for the NaBH4 reduction of 4-nitrophenol and for the aerobic oxidation of alcohols, reactions that are always conducted under green conditions. Both Pt and Pd nanoparticles show good catalytic activity in the reduction reaction, while in the aerobic oxidation reaction only the Pt nanoparticles were effective.
A fuzzy logic approach in feature based robot navigation using interval analysis and UKF (2004)

Multiple sensor fusion for robot localisation and navigation has attracted a lot of interest in recent years. This paper describes a sensor based navigation approach using an interval analysis (IA) based adaptive mechanism for an unscented Kalman filter (UKF). The robot is equipped with inertial sensors (INS), encoders and ultrasonic sensors. An UKF is used to estimate the robot position using the inertial sensors and encoders. Since the UKF estimates may be affected by bias, drift etc., an adaptive mechanism using IA to correct these defects in estimates is proposed. The IA robot position estimate may be conservative, in which case multiple measurements are taken and the multiple interval robot position is fused together using fuzzy logic to obtain a single interval robot position estimate. In the presence of landmarks the complementary robot position information from the IA algorithm using ultrasonic sensors is used to estimate and bound the errors in the UKF robot position estimate.
On WiFi Offloading in Heterogeneous Networks: Various Incentives and Trade-off Strategies (2016)

Due to the rapid development of wireless access technologies and smart terminals, mobile data traffic is continuously increasing, which is expected to lead to an explosive growth of data in heterogeneous networks especially cellular networks. It is significant for network operators to expand the capacity of cellular networks to avoid congestion and overload so as to guarantee users' satisfaction. Given that contemporary terminals are capable of both WiFi and cellular networks, WiFi offloading is envisioned as a promising solution to utilize the various benefits of WiFi and cellular networks to migrate traffic from cellular networks to WiFi networks. This paper surveys the state-of-the-art progress in the field of WiFi offloading. After discussing the requirements from the emerging 5G technology regarding the coexistence of WiFi and cellular networks, selecting and switching schemes are presented. The bandwidth and capacity of WiFi networks are usually excellent, whereas the coverage and energy efficiency may be unacceptable. We elaborate on several existing solutions of WiFi offloading schemes and discuss how the parameters of several kinds of heterogeneous networks affect the offloading decision. We also illustrate how multiple networks cooperate in heterogeneous networks in order to balance the offloading performance. We classify current various incentives of WiFi offloading into five categories: 1) capacity; 2) cost; 3) energy; 4) rate; and 5) continuity. Improving the capacity is the basic incentive, which can be further classified in terms of delay techniques. From operators' and users' perspectives, we also investigate various state-of-the-art incentives of WiFi offloading such as minimizing cost, saving energy consumption, and improving rate. Furthermore, WiFi offloading schemes that attempt to enhance continuity to deal with frequent disruption problems are further investigated, especially for vehicular scenarios. Finally, future research directions and challenges for WiFi offloading strategies are presented in various incentives of WiFi offloading.
Towards automated detection of feature interactions. (1994)

. The feature interaction problem occurs when the addition of a new feature to a system disrupts the existing services and features. This paper describes a tabular notation for specifying the functional behavior of telephony features. It also describes how four classes of feature interactions can be detected when features are specified in this new notation. The goal of this research is to develop a tool to automatically analyze feature specifications and detect interactions at the specification stage. 1 Introduction How does one add features to a system without disrupting the services and features already provided? A more difficult but related problem is: how can one ensure that combinations of independently developed services and features behave as expected? These questions, and other variations of the feature interaction problem, have plagued the telecommunications industry for several years [7]. More generally, they are problems that affect the development and evolution of ...
Correlation of imaging and histopathology of thrombi in acute ischemic stroke with etiology and outcome: a systematic review (2016)

The hyperdense artery sign is associated with RBC-rich thrombi and improved recanalization rates. However, there was no association between the histopathological characteristics of thrombi and stroke etiology and angiographic outcomes.
Coronary vasodilation and positive inotropic effect of non steroidal cardiotonics. (1986)

The effects of several cardiotonic agents (ARL-115, Amrinone, RMI 82-249, Milrinone, CI-914, RO 13-6438 and APP 201-533) were compared with those of ouabain on pig isolated coronary artery, guinea-pig isolated atria and guinea-pig perfused heart to compare vasodilatory and inotropic responses. Like ouabain, all compounds tested produce positive inotropic and chronotropic effects in isolated atria and on perfused heart, and induce relaxation in precontracted pig coronary artery and coronary vasodilation on perfused heart, except ouabain which induces vasoconstriction. The results indicate that non steroidal cardiotonics exert positive inotropic and coronary vasodilatory effects.
Laboratory versus Nondestructive Testing for Pavement Design (1992)

A detailed comparison of moduli measured in the laboratory by resilient modulus testing with moduli measured in the field by falling weight deflec‐tometer (FWD) testing is made. This comparison includes an analysis of whether good agreement between lab and field values should be expected as well as an assessment of relative quality of the results and relative testing costs. Good agreement between lab and field measured moduli should not be expected when following the usual practice of sampling and testing only the top 1 or 2 ft (0.3 or 0.6 m) of the subgrade. Agreement is not to be expected because different volumes of the material are being tested in the laboratory compared to field testing by FWD. Because different volumes of material are tested, heterogeneity in any layer contributes to different measured moduli by lab and field testing. It is also concluded that the cost of determining moduli by laboratory resilent modulus testing is typically 60–80 times greater than the cost of an equivalent field testing program with the FWD. When the added costs of traffic control during sampling and project delays are included, the cost ratio may exceed 100. Furthermore, the moduli from field FWD testing are typically of higher quality and more appropriate for mechanistic pavement design than lab‐measured moduli. This conclusion arises from the fact that it is very difficult, if not impossible, to erase completely the effects of sample disturbance on lab‐measured moduli. In addition, when moduli are back‐calculated from FWD testing, a proper weighting factor is automatically applied to all zones contributing to deformations, it is also possible to take advantage of compensating errors in back‐calculated moduli.
How many molecular subtypes? Implications of the unique tumor principle in personalized medicine (2012)

Cancers are complex multifactorial diseases. For centuries, conventional organ-based classification system (i.e., breast cancer, lung cancer, colon cancer, colorectal cancer, prostate cancer, lymphoma, leukemia, and so on) has been utilized. Recently, molecular diagnostics has become an essential component in clinical decision-making. However, tumor evolution and behavior cannot accurately be predicted, despite numerous research studies reporting promising tumor biomarkers. To advance molecular diagnostics, a better understanding of intratumor and intertumor heterogeneity is essential. Tumor cells interact with the extracellular matrix and host non-neoplastic cells in the tumor microenvironment, which is influenced by genomic variation, hormones, and dietary, lifestyle and environmental exposures, implicated by molecular pathological epidemiology. Essentially, each tumor possesses its own unique characteristics in terms of molecular make-up, tumor microenvironment and interactomes within and between neoplastic and host cells. Starting from the unique tumor concept and paradigm, we can better classify tumors by molecular methods, and move closer toward personalized cancer medicine and prevention.