gebhart/patrepeval huggingface dataset:
Modularly Designed Transition Metal PNP and PCP Pincer Complexes based on Aminophosphines: Synthesis and Catalytic Applications (2008)

Transition metal complexes are indispensable tools for any synthetic chemist. Ideally, any metal-mediated process should be fast, clean, efficient, and selective and take place in a catalytic manner. These criteria are especially important considering that many of the transition metals employed in catalysis are rare and expensive. One of the ways of modifying and controlling the properties of transition metal complexes is the use of appropriate ligand systems, such as pincer ligands. Usually consisting of a central aromatic backbone tethered to two two-electron donor groups by different spacers, this class of tridentate ligands have found numerous applications in various areas of chemistry, including catalysis, due to their combination of stability, activity, and variability. As we focused on pincer ligands featuring phosphines as donor groups, the lack of a general method for the preparation of both neutral (PNP) and anionic (PCP) pincer ligands using similar precursor compounds as well as the difficulty of introducing chirality into the structure of pincer ligands prompted us to investigate the use of amines as spacers between the aromatic ring and the phosphines. By introduction of aminophosphine and phosphoramidite moieties into their structure, the synthesis of both PNP and PCP ligands can be achieved via condensation reactions between aromatic diamines and electrophilic chlorophosphines (or chlorophosphites). Moreover, chiral pincer complexes can be easily obtained by using building blocks obtained from the chiral pool. Thus, we have developed a modular synthetic strategy with which the steric, electronic, and stereochemical properties of the ligands can be varied systematically. With the ligands in hand, we studied their reactivity towards different transition metal precursors, such as molybdenum, ruthenium, iron, nickel, palladium, and platinum. This has resulted in the preparation of a range of new pincer complexes, including various iron complexes, as well as the first heptacoordinated molybdenum pincer complexes and several pentacoordinated nickel complexes by using a controlled ligand decomposition pathway. In addition, we have investigated the use of some of the complexes as catalysts in different C-C coupling reactions: for example, the palladium PNP and PCP pincer complexes can be employed as catalysts in the well known Suzuki-Miyaura coupling, while the iron PNP complexes catalyze the coupling of aromatic aldehydes with ethyl diazoacetate under very mild reaction conditions to give selectively 3-hydroxyacrylates, which are otherwise difficult to prepare. While this Account presents an overview of current research on the chemistry of P-N bond containing pincer ligands and complexes, we believe that further investigations will give deeper insights into the reactivity and applicability of aminophosphine-based pincer complexes.
Comparative Analysis of Methods to DenoiseCT Scan Images (2013)

Medical images are generally noisy due to the physical mechanisms of the acquisition process. In CT Scan there is a scope to adapt patient image quality and dose. Reduction in radiation dose (i.e the amount of X-rays) affects the quality of image and is responsible for image noise in CT. Most of the denoising algorithms assume additive white Gaussian noise but however most medical images may contain non Gaussian noise like poisson noise in CT. This paper contains the comparative analysis of a number of denoising algorithms namely wiener filtering, wavelet decomposition, anisotropic diffusion, anisotropic diffusion in wavelet domain, wave atom decomposition, median filtering and NL-means filtering. Then, some quantitative performance metrics like PSNR, SNR, MSE, S/MSE and MAD are computed. This comparison helps in the assessment of image quality and fidelity. We conclude that the anisotropic diffusion in wavelet domain is the most efficient method in removing poisson noise from CT Scan images.
From RBAC to ABAC: Constructing Flexible Data Access Control for Cloud Storage Services (2014)

This paper addresses how to construct an RBAC-compatible secure cloud storage service with a user-friendly and easy-to-manage attribute-based access control (ABAC) mechanism. Similar to role hierarchies in RBAC, attribute hierarchies (considered as partial ordering relations) are introduced into attribute-based encryption (ABE) in order to define a seniority relation among all values of an attribute, whereby a user holding senior attribute values acquires permissions of his/her juniors. Based on these notations, we present a new ABE scheme called attribute-based encryption with attribute hierarchies (ABE-AH) to provide an efficient approach to implement comparison operations between attribute values on a poset derived from an attribute lattice. By using bilinear groups of a composite order, we present a practical construction of ABE-AH based on forward and backward derivation functions. Compared with prior solutions, our scheme offers a compact policy representation approach that can significantly reduce the size of private-keys and ciphertexts. To demonstrate how to use the presented solution, we illustrate how to provide richer expressive access policies to facilitate flexible access control for data access services in clouds.
Stochastic boundary element analysis of stress variation due to shape uncertainty. (1985)

不確定形状を有する弾性体の応力変動を効率よく解析する手法を, 二次摂動法と組合せた境界要素法により定式化した. 板厚が確率的に変動している平板等を想定し, 平面ひずみ状態にあり面内引張りをうける細長い長方形材の長辺輪郭が一次元的に不確定な場合の内部と表面の応力の分散を一定要素により解析した. 表面形状の不確定変動を自己相関関数により入力として与え, 出力である応力の分散に及ぼす影響を定量的に示した.
ChemInform Abstract: DILITHIUM‐NICKEL‐OLEFIN COMPLEXES. NOVEL BIMETAL COMPLEXES FROM A TRANSITION METAL AND A MAIN GROUP METAL (1976)

Abstract Der Ni(0)‐Komplex (I) in THF‐Lösung reagiert mit Li‐Sand und Tetramethyläthylendiamin zu dem Komplex (II), dessen Struktur anhand NMR‐spektroskopischer Daten diskutiert wird.
In Vitro and In Vivo Evaluation of Glibenclamide in Solid Dispersion Systems (2004)

The purpose of this work is to improve the dissolution and bioavailability characteristics of glibenclamide as compared to Daonil tablets (Hoechst). Solid dispersions of glibenclamide in Gelucire 44/14 (Formula 1) and in polyethylene glycol 6000 (PEG 6000) (Formula 2) were prepared by fusion method. In vitro dissolution studies showed that the dispersing systems containing glibenclamide and Gelucire 44/ 14 or PEG 6000 gave faster dissolution rates than the reference product Daonil. The in vivo bioavailability study was assessed in six healthy male volunteers in crossover design with a 1-week washout period. Both formulas were found to be significantly different from Daonil with regard to the extent of absorption as indicated by the area under serum concentration-time curve. Both formulas are not significantly different from Daonil with respect to time of peak plasma concentration Tmax. It is concluded from this pilot study that the ranking of the in vitro dissolution is similar to the ranking of in vivo availability. The ranking of the three preparations in term of dissolution rate and extent of absorption is as follows: Formula 2>Formula 1 >Daonil.
Basophils, IgE, and Autoantibody-Mediated Kidney Disease (2011)

Basophils are of interest in immunology due to their ability to produce a Th2-signature cytokine, IL-4, following activation. A new understanding of the role of basophils in immunity shows novel functions at a cellular level through which basophils influence adaptive immunity. This review summarizes new advances in basophil biology and discusses new roles for basophils in human disease, especially in the mediation of the pathogenesis of lupus nephritis. Recently, basophils have been shown to contribute to self-reactive Ab production in systemic lupus erythematosus and may enhance pre-existing loss of B cell tolerance, suggesting that basophils, IL-4, and IgE mediate the pathogenesis of lupus nephritis by promoting the Th2 environment and activating autoreactive B cells. In addition to envisaging exciting therapeutic prospects, these novel findings open the way for the study of basophils in other autoimmune and renal diseases.
Sub-parts-per-trillion level sensitivity in trace gas detection by cantilever-enhanced photo-acoustic spectroscopy (2018)

An exceptional property of photo-acoustic spectroscopy is the zero-background in wavelength modulation configuration while the signal varies linearly as a function of absorbed laser power. Here, we make use of this property by combining a highly sensitive cantilever-enhanced photo-acoustic detector, a particularly stable high-power narrow-linewidth mid-infrared continuous-wave optical parametric oscillator, and a strong absorption cross-section of hydrogen fluoride to demonstrate the ability of cantilever-enhanced photo-acoustic spectroscopy to reach sub-parts-per-trillion level sensitivity in trace gas detection. The high stability of the experimental setup allows long averaging times. A noise equivalent concentration of 650 parts-per-quadrillion is reached in 32 minutes.
Dissipation measurements of vacuum-operated single-crystal silicon microresonators (1995)

The quality factors of vacuum-operated single-crystal silicon microresonators have been measured, to identify their important sources of mechanical loss when medium-related loss is absent. The microresonators are torsional structures consisting of beams of width ≈ 0.7 μm, fabricated by reactive-ion etching from a single-crystal silicon substrate. For torsional microresonators having Q-factors around 50 000, doping-impurity and support-related losses do not seem to be significant. Rather, it appears that losses originating from beam surfaces, which are dry-etched, are important. This etched-surface loss can be halved by thermal oxidation, resulting in microresonators with Q-values consistently in the range 80 000–100 000. A model for this surface-related loss is presented.
Reduction of Artifacts Caused by Translational and Rotational Rigid Motion in Projection Reconstruction Magnetic Resonance Imaging (2007)

We present a new projection reconstruction magnetic resonance (MR) imaging sequence for the correction of artifacts caused by translational and/or rotational rigid motion. We performed brain imaging during which a volunteer &amp;apos;s head was moving in a combined translational and rotational rigid way. The MR signals were ordered in an interleaved way in order to reduce the motion sensitivity drastically. By using an original motion-determination technique, it was possible to determine the limited number of MR signals being distorted by motion with an accuracy of one repetition time. These signals were modified in order to correct for the translational and rotational motion that was present during the signal acquisition by calculating the translational shift and rotation angle of the object. Finally, it was possible to calculate a modified raw-data set that contained only very small distortions caused by motion. In conclusion, motion parameters are extracted from the measured raw data and use...
A Trajectory Generation Scheme for Precise and Safe Lunar Landing (2011)

Execution of scientific objectives such as to investigate the central peaks of a big crater of the moon is thought to be the most scientifically interesting. Precise and safe autonomous landing ability is a productive issue for this investigation. Here it is proposed a scheme of trajectory generation for lunar descent. This research includes a sketch of a qualitative scheme on solutions of motion control equations for lunar descent vehicle from orbital speed condition down to the terminal descent situation. A trajectory generation algorithm is developed accumulating more than one step with variable thrust to mass ratio. Mathematical modeling, algorithm design, simulations and results are presented in this paper. In fact, the proposed trajectory generation scheme can readily be used to develop real-time guidance algorithm for future precise and safe lunar landing missions reducing the computational burden.
Technical Note: Corrosion Behavior of Post-Deposition Polished Droplet-Embedded Arc Evaporated and Droplet-Free High Power Impulse Magnetron Sputtering/Direct Current Magnetron Sputtering Coatings (2017)

In this study, the effect of metal-rich core of the droplets on the corrosion properties of TiN, CrN, and ZrN arc evaporated nitride coatings has been investigated and the corrosion properties of such coatings have been compared with droplet-free, highly dense coatings grown by combined high power impulse magnetron sputtering (HIPIMS) and direct current magnetron sputtering (DCMS) technique. An industrial size coating deposition system enabled with HIPIMS technology was used for the deposition of combined HIPIMS/DCMS coatings. The corrosion behavior of the coatings was studied by potentiodynamic polarization test (−1 V to +1 V) using 3.5% NaCl solution. Initially, as-deposited arc evaporated coatings with an exposed surface area of 1 cm2 were subjected to corrosion. Then, the coatings were gently polished to expose the metal-rich core of the droplets. Subsequently, fresh uncorroded area of the polished coating was subjected to corrosion with previously corroded area masked. It has been found that mechanical polishing considerably deteriorated the corrosion performance of arc coatings by forming more than one galvanic couple between the two parts (metal-rich and nitrogen-rich) of the same droplet itself or between the metal-rich part and the adjoining coating/exposed substrate. It has been further demonstrated that the droplet-free highly dense HIPIMS/DCMS coatings exhibited superior corrosion resistance as compared to the arc evaporated coatings. Raman analysis was used to study the constituents of the corrosion products. Scanning electron microscopy (SEM, planar view) was used to examine the as-deposited and corroded coating surfaces to define morphological differences. Energy dispersive x-ray analysis was done to study the composition of the coatings. Cross-section SEM and ball cratering techniques were used to measure the thickness of the coatings.
Extraction of a low-current discharge from a microplasma for nanoscale patterning applications at atmospheric pressure (2011)

The authors present a scheme to extract a low-current discharge from a microplasma at atmospheric pressure for nanopatterning applications. The extracted discharge is generated by applying a high positive voltage to an independent electrode and accelerating electrons from the microplasma. Current-voltage (I–V) characteristics of the extracted discharge show high stability at low currents and tunability over a wide range of currents. Exposure of metal precursor loaded films to the extracted discharge results in electrochemical reduction of metal ions to solid metal, as confirmed by X-ray photoelectron spectroscopy. Combining this approach with masking techniques allows the transfer of nanoscale patterns of metal at ambient conditions.
Measurement of electron density in dual‐energy x‐ray CT with monochromatic x rays and evaluation of its accuracy (2008)

Information on electron density is important for radiotherapy treatment planning in order to optimize the dose distribution in the target volume of a patient. At present, the electron density is derived from a computed tomography (CT) number measured in x-ray CT scanning; however, there are uncertainties due to the beam hardening effect and the method by which the electron density is converted from the CT number. In order to measure the electron density with an accuracy of +/-1%, the authors have developed dual-energy x ray CT using monochromatic x rays. They experimentally proved that the measured linear attenuation coefficients were only a few percent lower than the theoretical ones, which led to an accuracy within 2% for the electron density. There were three factors causing inaccuracy in the linear attenuation coefficient and the electron density: the influence of scattered radiation, the nonlinearity in the detector response function, and a theoretical process to derive the electron density from the linear attenuation coefficients. The linear attenuation coefficients of water were experimentally proved to differ by 1%-2% from the theoretical one even when the scattering effect was negligible. The nonlinearity of the response function played an important role in correcting the difference in the linear attenuation coefficient. Furthermore, the theoretical process used for deriving the electron density from the linear attenuation coefficients introduces about 0.6% deviation from the theoretical value into the resultant electron density. This deviation occurs systematically so that it can be corrected. The authors measured the electron densities for seven samples equivalent to soft tissue in dual-energy x-ray CT, and finally obtained them with an accuracy of around +/-1%.
P04.03: Frontomaxillary facial angle at 11 + 0 to 13 + 6 weeks in Chinese population (2010)

To establish the normal range of frontomaxillary facial (FMF) angle in the first trimester in a Chinese population. In a prospective study from March 2007 to June 2007, three-dimensional (3D) volumes of the fetal profile in the mid-sagittal plane were recorded from 129 normal pregnancies screened for trisomy 21 by the combination of fetal nuchal translucency (NT) thickness, maternal serum free β-human chorionic gonadotropin (β-hCG) and pregnancy-associated plasma protein-A (PAPP-A) at 11–13 + 6 weeks. 3D volumes were examined using multiplanar techniques. The FMF angle of each case was measured. The relationship between the measured FMF angle with the other parameter was also examined. The mean FMF angle decreased from 86.8° for a crown–rump length (CRL) of 45 mm to 76.0° for a CRL of 84 mm (FMF angle = 99.49–0.28 × CRL, P < 0.0001). The mean (SD) delta FMF angle derived from our formula, 0.07 (4.26), was significantly larger than that from the published reference equation, − 1.40 (4.31) (P < 0.0001). In the first trimester, the FMF angle decreases with fetal CRL. There was small and clinically insignificant difference in the normal value of FMF angle between the Chinese and Caucasian population. Supporting information can be found in the online version of this abstract. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.
Study on detection of EDM discharging position. 2nd report.Detection of wire EDM discharging position. (1990)

Local concentration of dischargings during machining causes poor cut results on Vertical EDM, also wire breakage on WIRE EDM. If discharging position is detected during machining, various controls are possible, examples ; prevention of wire breakage, current wave control depending on working area or to avoide corner wear of electrode and control of reverse direction on Vertical EDM. 1) In previous report we measured discharging position for insulated plates on WIRE EDM and found local concentration of dischargings took place just before wire breaks down. But this measuring method is not useful for nomall machining.
Analysis of a tractable model for combustion instability: the effect of delay and low pass filtering (2006)

In this paper a new analytically tractable model for combustion instability is proposed. The model is based on two coupled resonators in a feedforward path, and a feedback path composed of a delay, generalized Van der Pol term and a low pass filter. The model is analyzed and approximated using a refined Krylov-Bogoliubov (K-B) method. The analysis shows that the model captures the phenomenon of two coexisting oscillating modes which has been noted in combustion instability by Dunstan (2003). Conditions for the occurrence of various operation regimes have been established. The importance of delay and low pass filtering is discussed in this article. A frequency domain comparison between K-B approximations and the true outputs of the model has been provided in the end of the paper
A 77 GHz SiGe power amplifier for potential applications in automotive radar systems (2004)

We present the performance of a 77 GHz power amplifier for potential applications directed towards automotive radar systems. The circuit was fabricated in a SiGe bipolar preproduction technology. A balanced two-stage common emitter circuit topology was used to achieve 6.1 dB of power gain at 77 GHz and 11.6 dBm output power at 1dB compression. The power amplifier uses a single 2.5 V supply and was fully integrated (including matching elements) to demonstrate its low-cost potential. First experimental results show its broadband characteristic from 40 GHz to 80 GHz and its temperature dependence up to 130/spl deg/C.
Mef2C is a lineage-restricted target of Scl/Tal1 and regulates megakaryopoiesis and B-cell homeostasis (2009)

The basic helix-loop-helix transcription factor stem cell leukemia gene (Scl) is a master regulator for hematopoiesis essential for hematopoietic specification and proper differentiation of the erythroid and megakaryocyte lineages. However, the critical downstream targets of Scl remain undefined. Here, we identified a novel Scl target gene, transcription factor myocyte enhancer factor 2 C (Mef2C) from Scl(fl/fl) fetal liver progenitor cell lines. Analysis of Mef2C(-/-) embryos showed that Mef2C, in contrast to Scl, is not essential for specification into primitive or definitive hematopoietic lineages. However, adult VavCre(+)Mef2C(fl/fl) mice exhibited platelet defects similar to those observed in Scl-deficient mice. The platelet counts were reduced, whereas platelet size was increased and the platelet shape and granularity were altered. Furthermore, megakaryopoiesis was severely impaired in vitro. Chromatin immunoprecipitation microarray hybridization analysis revealed that Mef2C is directly regulated by Scl in megakaryocytic cells, but not in erythroid cells. In addition, an Scl-independent requirement for Mef2C in B-lymphoid homeostasis was observed in Mef2C-deficient mice, characterized as severe age-dependent reduction of specific B-cell progenitor populations reminiscent of premature aging. In summary, this work identifies Mef2C as an integral member of hematopoietic transcription factors with distinct upstream regulatory mechanisms and functional requirements in megakaryocyte and B-lymphoid lineages.
Kudos to Bob Glass and Rebecca Wirfs-Brock (2010)

These letters deal with the retirement of Rebecca Wirfs-Brock and Bob Glass, systems architecture, domain-specific languages, the certification of requirements analysts, measurement, and reading classics.
A Multiple‐Access Time and Frequency Spectrum‐Spreading Modulation (2018)

In this paper a novel modulation scheme called Carrier Interleaved Multiple Access (CIMA) is proposed. CIMA provides an alternative for multiple‐access modulation accommodating resistance to noise and channel interference. The approach is based on polar signaling modulated with an FM‐like composite sinusoidal function. The user assigned frequency deviation and modulation index are strictly related and unique. The latter parameters are generated using a nontraditional pseudorandom noise generator (PRNG). This PRNG provides CIMA with low interference capability between cochannels and adjacent channels. CIMA can be considered for a single‐user or multiple‐access technique. Selected CIMA characteristics are presented. In order to numerically illustrate the effectiveness of the proposed modulation scheme, the performance of CIMA is compared with the conventional direct‐sequence spread spectrum binary phase‐shift keying (DSSS‐BPSK) modulation.