gebhart/patrepeval huggingface dataset:
Reactivity of Iridium Complexes of a Triphosphorus-Pincer Ligand Based on a Secondary Phosphine. Catalytic Alkane Dehydrogenation and the Origin of Extremely High Activity (2021)

The selective functionalization of alkanes and alkyl groups is a major goal of chemical catalysis. Toward this end, a bulky triphosphine with a central secondary phosphino group, bis(2 di-t-butyl-phosphinophenyl)phosphine (tBuPHPP), has been synthesized. When complexed to iridium it adopts a meridional (“pincer”) configuration. The secondary phosphino H atom can undergo migration to iridium to give an anionic phosphido-based-pincer (tBuPPP) complex. We describe novel metal-ligand cooperativity of the iridium-phosphido unit. Stoichiometric reactions of the (tBuPPP)Ir complexes reflect a distribution of steric bulk around the iridium center in which the coordination site trans to the phosphido group is quite crowded, one coordination site cis to the phosphido is even more crowded, while the remaining site is particularly open. The (tBuPPP)Ir precursors are the most active catalysts reported to date for dehydrogenation of n-alkanes, by about two orders of magnitude. The electronic properties of the iridium center are very similar to that of well-known analogous (RPCP)Ir catalysts. Accordingly, DFT calculations predict that (tBuPPP)Ir and (tBuPCP)Ir are, intrinsically, comparably active for alkane dehydrogenation. While dehydrogenation by (RPCP)Ir proceeds through an intermediate trans-(PCP)IrH2(alkene), (tBuPPP)Ir follows a pathway proceeding via cis-(PPP)IrH2(alkene), thereby circumventing unfavorable placement of the alkene at the bulky site trans to phosphorus. (tBuPPP)Ir and (tBuPCP)Ir, however, have analogous resting states: square planar (pincer)Ir(alkene). Alkene coordination at the crowded trans site is therefore unavoidable in the resting states. Thus the resting state of the (tBuPPP)Ir catalyst is destabilized by the unusual architecture of the ligand, and this is largely responsible for its unusually high catalytic activity.
Microbiology: Principles and applications (1990)

Microbiology: Principles and applications , Microbiology: Principles and applications , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی
Regeneration and Recycling of Aqueous Periodate Solution in Dialdehyde Cellulose Production (2013)

Abstract The regeneration of aqueous iodate solution from the regioselective periodate oxidation of softwood cellulose pulp to dialdehyde cellulose using hypochlorite as a secondary oxidant was studied. The influence of oxidation time on the pulp dissolution and regeneration efficacy was examined in particular. In addition, the recycling of regenerated periodate solution back to oxidation was clarified. The solutions from the 10 and 15 min oxidations were regenerated with 100% conversion efficacy when 1.2–1.4 times the stoichiometric amounts of hypochlorite were used. However, the regeneration efficacy decreased when the reaction time in the oxidation increased to 30 min because the content of soluble impurities, which consumed the hypochlorite in the side-reactions, increased significantly as the oxidation reaction proceeded. The regenerated solutions possessed good oxidation performance, showing that periodate was successfully regenerated using hypochlorite and supporting the assumption that periodate can be effectively recycled in the process when short oxidation times are used.
Nucleotide polymorphism and evolution in the glyceraldehyde-3-phosphate dehydrogenase gene (gapA) in natural populations of Salmonella and Escherichia coli. (1991)

Nucleotide sequences of the gapA gene, encoding the glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase, were determined for 16 strains of Salmonella and 13 strains of Escherichia coli recovered from natural populations. Pairs of sequences from strains representing the eight serovar groups of Salmonella differed, on average, at 3.8% of nucleotide sites and 1.1% of inferred amino acids, and comparable values for E. coli were an order of magnitude smaller (0.2% and 0.1%, respectively). The rate of substitution at synonymous sites was significantly higher for codons specifying the catalytic domain of the enzyme than for those encoding the NAD(+)-binding domain, but the nonsynonymous substitution rate showed the opposite relationship. For Salmonella, statistical tests for nonrandom clustering of polymorphic sites failed to provide evidence that intragenic recombination or gene conversion has contributed to the generation of allelic diversity. The topology of a tree constructed from the gapA sequences was generally similar to that of phylogenetic trees of the strains based on multilocus enzyme electrophoresis, but the level of divergence of gapA in Salmonella group V from other Salmonella and E. coli strains is much greater than that indicated by DNA hybridization for the genome as a whole.
Kinetic Dependence of Paramyxovirus Entry Inhibition (2009)

Peptides derived from conserved heptad repeat (HR) regions of paramyxovirus fusion (F) proteins inhibit viral fusion by interfering with the formation of the fusogenic six-helix bundle structure. Peptide efficacy is affected by the strength of the peptide association with the target virus's complementary HR region. Here, we show that a second basis for peptide efficacy lies in the kinetics of F activation by the homotypic attachment protein: efficient F activation by the attachment protein shortens the period during which antiviral molecules targeting intermediate states of F may act, thereby modulating the effectiveness of inhibitory peptides. These results highlight new issues to be considered in developing strategies for fusion inhibitors.
Ghrelin Plasma Levels Are Not Altered in Major Depression (2009)

This is the first comparison of ghrelin secretion patterns in patients with major depression and healthy controls. Surprisingly, no relevant differences were ascertained between the two groups.
Intracytoplasmic Sperm Injection: Technical Improvement (2005)

Successful fertilization using intracytoplasmic sperm injection (ICSI) was first reported in 1988 and the first successful ICSI pregnancy was in 1992. Since then, this technology has quickly become an indispensable technique in reproductive medicine, and its validity has been verified through several clinical studies over the past 10 years. After several technologic improvements, the rate of ICSI fertilization is comparable to that of conventional in vitro fertilization. In this article, we discuss how ICSI has improved fertilization and pregnancy rates.
(Invited) Photocatalytic Conversion of CO2 By H2o As an Electron Donor over Ag/ZnGa2O4/Ga2O3 (2015)

Many research groups have already made significant progress in the field of water splitting to produce pure H2 and O2; in contrast, studies on the photocatalytic conversion of CO2 using H2O as a reductant are very few. This is because in such systems, overall water splitting occurs together with the reduction of CO2, resulting in H2 being the main product. Thus, it is very important to control the reduction of protons in the presence of both CO2 and H2O in order to achieve the reduction of CO2 by H2O. In this study, we found that Ag/ZnGa2O4/Ga2O3 exhibits a higher conversion of CO2 as compared to several photocatalysts reported previously. CO was evolved as the main product during the photocatalytic conversion of CO2 over 1 wt% Ag/ZnGa2O4/Ga2O3 under UV irradiation. H2 was simultaneously generated as the reduction product similar to CO, although the amount of H2 evolved was tiny as compared to that of CO. Expectedly, the evolution of O2 was observed together with those of CO and H2. After 7 h of photoirradiation, we obtained 815 μmol of CO, 65.7 μmol of H2, and 479 μmol of O2. The reaction could be carried out stably over three times, indicating that Ag/ZnGa2O4/Ga2O3 is very stable in water and under photoirradiation.
<b>SYNTHESIS AND ANTIBACTERIAL ACTIVITY OF INSIGNIN AND ITS 8-METHOXY- AND 6-DEMETHOXY DERIVATIVES</b> (2006)

A short and efficient synthesis of insignin (8-hydroxy-6-methoxy-3-heptyl- isocoumarin) (1), a metabolite of natural lichens, has been described. Reaction of 3,5-dimethoxyhomophthalic anhydride (2) with octanoyl chloride in the presence of 1,1,3,3-tetramethylguanidine (TMG) and triethyl amine afforded the 6,8-dimethoxy-3-heptylisocoumarin (3) in high yield. Regioselective demethylation of the latter using anhydrous aluminum chloride furnished the 8-hydroxy-6-methoxy-3-heptylisocoumarin (1) whereas, the complete demethylation of (3) yielded 6,8-dihydroxy-3-heptylisocoumarin (4). The isocoumarins (1, 3, and 4) were examined in vitro for antibacterial activity and were shown to exhibit moderate activity. KEY WORDS: Isocoumarin, Insignin, Antibacterial, Porpidia glaucophaea, Haematomma pachycarpum, 3,5-Dimethoxyhomophthalic anhydride Bull. Chem. Soc. Ethiop. 2006, 20(1), 83-87.
A 10-bit 2GHz Current-Steering CMOS D/A Converter (2007)

This paper presents a 2GS/s 10-bit CMOS digital-to-analog converter (DAC). This DAC consists of a unit current-cell matrix for 6MSBs and another unit current-cell matrix for 4LSBs, trading off between the precision and size of the chip. The current mode logic (CML) is used to ensure high speed, and a double centro-symmetric current matrix is designed by the Q <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> random walk strategy in order to ensure the linearity of the DAC. The DAC occupies 2.2 times 2.2 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> of die area, and consumes 790mw at a single 3.3V power supply
Co‐evolution of HAD phosphatase and hotdog‐fold thioesterase domain function in the menaquinone‐pathway fusion proteins BF1314 and PG1653 (2013)

The function of a Bacteroidetes menaquinone biosynthetic pathway fusion protein comprised of an N-terminal haloacid dehalogenase (HAD) family domain and a C-terminal hotdog-fold family domain is described. Whereas the thioesterase domain efficiently catalyzes 1,4-dihydroxynapthoyl-CoA hydrolysis, an intermediate step in the menaquinone pathway, the HAD domain is devoid of catalytic activity. In some Bacteroidetes a homologous, catalytically active 1,4-dihydroxynapthoyl-CoA thioesterase replaces the fusion protein. Following the gene fusion event, sequence divergence resulted in a HAD domain that functions solely as the oligomerization domain of an otherwise inactive thioesterase domain.
Isotope sensitive branching and kinetic isotope effects to analyse multiproduct terpenoid synthases from Zea mays (2015)

Multiproduct terpene synthases TPS4-B73 and TPS5-Delprim from Zea mays exhibit isotopically sensitive branching in the formation of mono- and sesquiterpene volatiles. The impact of the kinetic isotope effects and the stabilization of the reactive intermediates by hyperconjugation along with the shift of products from alkenes to alcohols are discussed.
<title>DC bias modulation characteristics of longitudinal KD*P modulators</title> (1992)

A test program designed to study the DC modulation characteristics of longitudinal KD*P modulators and to determine what electrode structure might improve the performance of these devices is presented which was developed in the Marshall Space Flight Center. The physical constraints of these devices and the necessary electrical characteristics that the KD*P modulators must have to be used in the MSFC polarimeter are discussed.
A Cybersecurity Architecture for the L-band Digital Aeronautical Communications System (LDACS) (2018)

With air transportation growing and current civil aeronautical communication systems reaching their capacity limit in high density areas, the need for new aeronautical communication technologies becomes apparent. The biggest challenge in recent years is the transition from analogue voice to digital data communication and the related trend towards an increased autonomous data processing. A promising candidate for the digital future communication infrastructure in continental areas is the terrestrial long-range L-band Digital Aeronautical Communications System (LDACS), which is currently in the process of being standardized by the International Civil Aviation Organization (ICAO). As safety and security are strongly intertwined in civil aviation, every installation of LDACS requires protection against cyber-attacks. This paper introduces a cybersecurity architecture for LDACS and proposes suitable security algorithm, which can achieve the security objectives on top of the architecture. Therefore we integrate new security functions within the existing protocol stack of LDACS. We provide an architecture for user data encryption, data integrity, authenticated key agreement, entity authentication, broadcast channel protection, and key and access management.
Mechanism of non-Shockley conduction in almost ideal silicon junction diodes (1984)

Well-gettered diodes behave as ideal Shockley diodes for forward bias. For reverse bias their characteristics may deviate from the Shockley theory according to the preparation precedure. A model for this behavior is presented; it ascribes the deviation to a generation current produced at donor-acceptor shallow levels in the depletion layer.
Atomic force microscopy visualizes mobility of photosynthetic proteins in grana thylakoid membranes (2018)

ABSTRACT Thylakoid membranes in chloroplasts contain photosynthetic protein complexes that convert light energy into chemical energy. Photosynthetic protein complexes are considered to undergo structural reorganization to maintain the efficiency of photochemical reactions. A detailed description of the mobility of photosynthetic complexes in real-time is necessary to understand how macromolecular organization of the membrane is altered by environmental fluctuations. Here, we used high-speed atomic force microscopy to visualize and characterize the in situ mobility of individual protein complexes in grana thylakoid membranes isolated from Spinacia oleracea . Our observations reveal that these membranes can harbor complexes with at least two distinctive classes of mobility. A large fraction of grana membranes contained proteins with quasi-static mobility, exhibiting molecular displacements smaller than 10 nm 2 . In the remaining fraction, the protein mobility is variable with molecular displacements of up to 100 nm 2 . This visualization at high-spatiotemporal resolution enabled us to estimate an average diffusion coefficient of ∼1 nm 2 s -1 . Interestingly, both confined and Brownian diffusion models could describe the protein mobility of the second group of membranes. We also provide the first direct evidence of rotational diffusion of photosynthetic complexes. The rotational diffusion of photosynthetic complexes could be an adaptive response to the high protein density in the membrane to guarantee the efficiency of electron transfer reactions. This characterization of the mobility of individual photosynthetic complexes in grana membranes establishes a foundation that could be adapted to study the dynamics of the complexes inside the intact and photosynthetically functional thylakoid membranes to be able to understand its structural responses to diverse environmental fluctuations. STATEMENT OF SIGNIFICANCE We characterized the dynamics of individual photosynthetic protein complexes in grana thylakoid membranes from Spinacia oleracea by high-speed atomic microscopy (HS-AFM). Direct visualization at high spatiotemporal resolution unveils that the mobility of photosynthetic proteins is heterogeneous but governed by the confinement effect imposed by the high protein density in the thylakoid membrane. The photosynthetic complexes display rotational diffusion, which might be a consequence of the crowded environment in the membrane and a mechanism to sustain an efficient electron transfer chain.
Fair Allocation of Asymmetric Operations in Storage Systems (2020)

Managing the trade-off between efficiency and fairness in a storage system is challenging due to high variability in workload behavior. Most workloads are made up of a mix of asymmetric operations (e.g. read/write, sequential/random, or striped/isolated I/Os) in different proportions, which places different resource demands on the storage device. The problem is to allocate device resources to the heterogeneous workloads fairly while maintaining high device throughput. In this paper, we present a new model for fair allocation of heterogeneous workloads with different ratios of asymmetric operations. We propose an adaptive scheme that chooses between two policies-the traditional Time-Balanced Allocation (TBA) and our proposed Bottleneck-Balanced Allocation (BBA)-based on workload characteristics. The fairness and throughput of these allocation policies are established through formal analysis. Our algorithms are tested with an adaptive, dynamic scheduler implemented in a simulation testbed, and the results validate the performance benefits of our approach.
Long-term Visual Outcome after Nonradical Microsurgery in Patients with Parasellar and Cavernous Sinus Meningiomas (2000)

Radical surgery is not required to achieve long-term useful visual function for patients with parasellar or cavernous sinus meningiomas.
Bertrand Tavernier: the film-maker of Lyon (2001)

Bertrand Tavernier political film-maker humanist film-maker l'horloger de Saint-Paul, 1973 que fete commence..., 1975 le juge et l'assassin, 1976 des enfants gates, 1977 death watch, 1979 une semaine de vacances, 1980 coup de Torchon, 1981 un dimanche a campagne, 1984 round midnight, 1986 la passion Beatrice, 1987 la vie et rien d'autre, 1989 daddy nostalgie, 1991 L.627, 1992 la fille de D'Artagnan, 1994 l'appat, 1995 capitaine Conan, 1996 ca commence aujord'hui, 1999 directing the film-maker of Lyon.
Microscopic Study on Hydrogenation Mechanism of MgH<sub>2</sub> Catalyzed by Nb<sub>2</sub>O<sub>5</sub> (2014)

We propose the microstructural change model of magnesium hydride catalyzed by Nb2O5 during hydrogenation. The ball-milled composites, MgH2 and 1 mol% Nb2O5, were dehydrogenated and then rehydrogenated for varied time at room temperature under 0.1 MPa H2 atmosphere. The crystallite size of Mg and MgH2 was evaluated by powder X-ray diffraction (XRD) measurement and confirmed by transmission electron microscopy (TEM) observation. The crystallite size of generated MgH2 was smaller than that of Mg and did not change significantly with increasing time of hydrogenation. It is suggested that the number density of MgH2 crystallites increases during the hydrogenation process.
Quantitative Characterization of Regenerating Axons after End-to-Side and End-to-End Coaptation in a Rat Brachial Plexus Model: A Retrograde Tracer Study (2007)

The efficacy of end-to-side repair as a method of nerve reconstruction has been questioned, and most studies that characterize the mode of re-innervation are marred by inappropriate experimental design and lack quantitative analysis. This makes characterization of re-innervating neurons confusing and consequently controversy remains as to the extent and source of reinnervating axons. In an experimental brachial plexus rat model, we transected the musculocutaneous nerve, labeled its neuron pool with Fast-Blue and joined the distal stump to the side of the intact ulnar nerve, or to the proximal stump of the divided ulnar nerve, to characterize neurons that reinnervate the recipient nerve. Tetramethyl-rhodamine dextran (TMRD) or fluoro-gold was used to map the reinnervating motor and sensory neurons at 12 weeks post-transection. No neurons originally labeled from musculocutaneous nerve were subsequently labeled with TMRD or fluoro-gold, showing that this original neuron pool does not contribute to re-innervation of the distal musculocutaneous nerve, but that reinnervation occurs solely by ulnar nerve motor and sensory axons. In the end-to-side group, 16.4% of the motor and 7% of the sensory donor ulnar nerve neurons re-innervated the musculocutaneous nerve exclusively, and a further 10% motor and 11.6% sensory innervated the musculocutaneous nerve by collateral sprouting of their axons. This compared to re-innervation by 62.6% of motor and 70.4% of ulnar nerve sensory neurons in the positive control that underwent end-to-end repair. Our results confirm the concept of collateral sprouting and support the use of end-to-side repair.
Thin-film induced stress in GaAs ridge-waveguide structures integrated with sputter-deposited ZnO films (1994)

ZnO films were deposited on a GaAs ridge structure using radio-frequency (rf)-magnetron sputtering. A SiO2 thin buffer layer was introduced to alleviate a thermal mismatching problem between the ZnO film and the GaAs substrate. Deposition parameters such as rf power, distance, and gas composition/pressure were optimized to obtain highly c-axis oriented and highly resistive ZnO films. Postdeposition anneal treatment at 430 °C for 5–10 min was found to enhance c-axis orientation of the ZnO films dramatically and to reduce intrinsic stress significantly. Stress on the cleaved facet of the waveguide was imaged with a spatially resolved and polarization-resolved photoluminescence technique. The results showed that the GaAs mesa is stressed up to 1×109 dyn/cm2 (10−3 strain) due to residual stress from the ZnO/SiO2/GaAs structure.
Hole trapping in SiO2 films annealed in low-pressure oxygen atmosphere (1987)

The generation of hole traps in thermal SiO2 films on Si(100) has been characterized as a function of O2 partial pressure in the annealing ambient in order to address the chemistry associated with the hole traps. The annealing treatments were carried out in ultrahigh vacuum (base pressure∼5×10−9 Torr) without and with the presence of an intentional (controlled) partial pressure of O2 in the range 10−6–5×10−2 Torr. Hole trapping was characterized using the avalanche injection technique. Annealing in vacuum results in an increased hole trapping rate similar to that observed for high-temperature (T&amp;gt;900 °C) furnace annealing in N2. The hole trapping is reduced upon annealing in O2 containing ambients if the O2 partial pressure exceeds the SiO vapor pressure by at least one order of magnitude. Thus, the presence of sufficient O2 in the postoxidation annealing process suppresses hole trapping. These results appear analogous to the reduction in low-field breakdown when O2 is present, as recently reported. In both cases, it is likely that the O2 serves to reoxidize a defect related SiO product which is generated by Si-SiO2 reaction at the interface.