gebhart/patrepeval huggingface dataset:
Circularly Permuted β-Lactamase from <i>Staphylococcus aureus</i> PC1<sup>,</sup> (1997)

The role that domain flexibility plays in the enzymatic activity of beta-lactamase from Staphylococcus aureus PC1 was investigated by producing two circularly permuted molecules. The C- and N-termini of the wild-type enzyme are adjacent to each other and remote from the active site, which is located between two domains. The polypeptide chain crosses over from one domain to the other twice. For the circularly permuted molecules, the termini were joined by an eight amino acid residue insertion, and new termini were introduced elsewhere. The first construct, termed cp254, was cleaved in a loop remote from the domain interface. The crystal structure of cp254 has been determined and refined at 1.8 A resolution, revealing essentially the same structure as that of the native protein. The activity profile with a representative sample of beta-lactam antibiotics is also very similar to that of wild-type beta-lactamase. The termini of the second circularly permuted mutant, cp228, occur within the second crossover region and therefore may enhance the flexibility of the molecule. Cp228 beta-lactamase shows a large decrease in enzymatic activity toward the sample of beta-lactam antibiotics, with catalytic rates that are 0.5-1% of those of the wild-type enzyme. One exception is the hydrolysis of the third generation cephalosporin, cefotaxime, which is hydrolyzed by the cp228 enzyme 10-fold faster than by wild-type beta-lactamase. Cp228 has not been crystallized. However, the circular dichroism spectra of the two circularly permuted proteins are very similar, indicating that, by analogy to cp254, cp228 adopts a global folded state. Thermal denaturation experiments reveal that cp254 is somewhat less stable than the wild-type enzyme, whereas cp228 is substantially less stable. Together, the data highlight the profound consequences that introducing flexibility at the domain interface has on both enzyme activity and protein stability.
The Development of Alkoxy-Based Sol -Gel Processing for Magnetoresistive Manganite Thin Films (2005)

This dissertation presents, for the first time, the successful development of an all-alkoxy based, sol-gel process for integrating thin films of magnetoresistive doped-lanthanide manganites onto silicon-based substrates. Crystallization of the requisite perovskite phase at temperatures below 650°C resulted from the incorporation of all-alkoxide precursors, and in particular, Mn[OC(CH 3 ) 3 )] 2 . This latter precursor, when combined with the polyfunctional solvent, 2-methoxyethanol, exhibited high solubility and hydrolytic reactivity. This accomplishment represents a significant new contribution because low carbon-content manganese(II) alkoxides are stable, insoluble coordinate polymers.\n\nOrange and pinkish-orange solutions, also synthesized for the first time, were free from products of aerobic oxidation, and hence, contained no brown discoloration. A partial hydrolysis of h = 0.25 produced a polymeric sol system, conferring both spinnable viscosities and excellent sol longevity. Post-coating hydrolysis via humidified air proved essential to yield transparent, dense, and defect-free amorphous coatings. Conversion into a fine-grain, polycrystalline microstructure occurred above 600°C on platinized-Si(100) and above 650°C on Si(100).\n\nThe cubic lattice parameters of the films (i.e., a = ∼ 3.90 Å) were in excellent agreement with values published in the literature for bulk, polycrystalline powders. Typical grain sizes started at 10-15 nm, increasing to 20-25 nm by 750°C. For films deposited on Si(100), magnetoresistance was observed in specimens heat treated at 700°C and 750°C, and for platinized-Si(100), 650°C, 700°C, and 750°C. Magnetoresistive response improved with heat-treatment temperature for the more refractory La0.67Ba 0.33 MnO 3 composition. The lead-doped counterpart offered the best property evolution, with T C = 320 K and T IM = 254 K by 750°C on platinized-Si(100). All corresponding transport curves were symmetric, demonstrating clear metal-insulator transitions (i.e., T IM ). High resistivities (i.e., ∼ 10 6 Ω-cm) were attributed to the fine-grain microstructure. Weak-field cycling between ±500 Oe yielded symmetrical loops with appreciable linear regions, a highly-desirable characteristic for magnetic sensing applications.
Enhancement of drug susceptibility of multi-drug resistant strains of <i>Mycobacterium tuberculosis</i> by ethambutol and dimethyl sulphoxide (1995)

Strategies to augment conventional methods of drug delivery in treatment of multiple drug resistant tuberculosis are needed to achieve optimum results with available drugs. We have studied the effect of sub-minimum inhibitory concentrations (sub-MIC) of ethambutol and dimethyl sulphoxide on drug susceptibility of Mycobacterium tuberculosis strains both in vitro and in macrophages. At sub-MIC ethambutol between caused four and 64 fold increase in susceptibility to isoniazid rifampicin and streptomycin in four M. tuberculosis strains, resistant to these drugs. Incubation of the organisms with isoniazid and sub-MIC of dimethyl sulphoxide (2.5%) resulted in an eight-fold increase in susceptibility to the drug. Previous exposure of the organisms to sub-MIC of dimethyl sulphoxide also caused similar enhancement of susceptibility. Both ethambutol and dimethyl sulphoxide at the sub-MIC of sulphoxide also caused similar enhancement of susceptibility. Both ethambutol and dimethyl sulphoxide at the sub-MIC enhanced the activity of the anti-tuberculosis drugs against multiple drug resistant M. tuberculosis strains growing inside macrophages. Our data indicate that the agents which modify cell wall permeability can enhance the susceptibility of multiple drug resistant strains to drugs to which they were originally resistant. This could provide a new approach to treating drug resistant tuberculosis.
Flight Trial Architectures Supporting Migration to Broadband IP for AOC and ATS (2006)

This paper introduces architectural concepts that address the migration from the current AOC ACARS and ATS ACARS (FANS) data link applications over the existing narrowband A/G subnetworks to the use of IP based broadband subnetworks. The first proposed transition step is the tunneling of AOC ACARS and ATS ACARS messages over broadband IP networks such as Gate link and the Inmarsat's SwiftBroadBand service. Proposed operational architectures are introduced along with lab demonstration/flight trial architectures alternatives that provide lower cost and risk options
Impacts of Array Configuration on Land-Use Requirements for Large-Scale Photovoltaic Deployment in the United States: Preprint (2008)

Land use is often cited as an important issue for renewable energy technologies. In this paper we examine the relationship between land-use requirements for large-scale photovoltaic (PV) deployment in the U.S. and PV-array configuration. We estimate the per capita land requirements for solar PV and find that array configuration is a stronger driver of energy density than regional variations in solar insolation. When deployed horizontally, the PV land area needed to meet 100% of an average U.S. citizen's electricity demand is about 100 m2. This requirement roughly doubles to about 200 m2 when using 1-axis tracking arrays. By comparing these total land-use requirements with other current per capita land uses, we find that land-use requirements of solar photovoltaics are modest, especially when considering the availability of zero impact 'land' on rooftops. Additional work is need to examine the tradeoffs between array spacing, self-shading losses, and land use, along with possible techniques to mitigate land-use impacts of large-scale PV deployment.
Touch Screen Maneuver Approval Mechanisms for Highly Automated Vehicles (2017)

Prototypes of highly automated vehicles are already able to drive on public roads, however fully automated rides where humans in the vehicle have only the role of a passenger regardless in which environment they travel are far away. Major issues are limited sensor range, mixed traffic, and an insufficient capability of classifying situations. We propose that vehicles can cooperate with the human inside to overcome such system boundaries. A possible input modality for driver-vehicle interaction in such scenarios are touch screens. We investigated three implementations regarding different confirmation processes to avoid erroneous inputs. Our evaluation in a driving simulator with 18 participants indicates that drivers prefer a one-tap selection, however they accept error prevention mechanisms like a confirmation dialog to approve maneuvers in more dynamic and complex scenarios. Moreover, these mechanisms did not have a negative effect on usability and workload.
71. Mesomorphism and chemical constitution. Part VIII. The effect of 3′-substituents on the mesomorphism of the 4′-n-alkoxydiphenyl-4-carboxylic acids and their alkyl esters (1957)

G. W. Gray, B. Jones and F. Marson, J. Chem. Soc., 1957, 393 DOI: 10.1039/JR9570000393
A dynamic electron image information store (1966)

A cascade image intensifier with low velocity electron image storage is being developed. The device has been used successfully as a framing camera: more than 108 frames per sec have been recorded. It is shown that the time delay introduced in the electron image could be used in nuclear physics to give resolving times of a few nanoseconds. The possibility of using the device as the fast store in an opto-electronic computer system is being investigated. It is further shown that the device may be adapted to extend sampling oscilloscope techniques in order to display transient phenomena.
Alternative stabilities of a proline‐rich antibacterial peptide in vitro and in vivo (2008)

The proline-rich designer antibacterial peptide dimer A3-APO is currently under preclinical development for the treatment of systemic infections caused by antibiotic-resistant Gram-negative bacteria. The peptide showed remarkable stability in 25% mouse serum in vitro, exhibiting a half-life of approximately 100 min as documented by reversed-phase chromatography. Indeed, after a 30-min incubation period in undiluted mouse serum ex vivo, mass spectrometry failed to identify any degradation product. The peptide was still a major peak in full blood ex vivo, however, with degradation products present corresponding to amino-terminal cleavage. When injected into mice intravenously, very little, if any unmodified peptide could be detected after 30 min. Nevertheless, the major early metabolite, a full single-chain fragment, was detectable until 90 min, and this fragment exhibited equal or slightly better activity in the broth microdilution antimicrobial assay against a panel of resistant Enterobactericeae strains. The Chex1-Arg20 metabolite, when administered three times at 20 mg/kg to mice infected with a sublethal dose (over LD(50)) of an extended spectrum beta-lactamase-producing Escherichia coli strain, completely sterilized the mouse blood, similar to imipenem added at a higher dose. The longer and presumably more immunogenic prodrug A3-APO, injected subcutaneously twice over a 3-wk period, did not induce any antibody production, indicating the suitability of this peptide or its active metabolite for clinical development.
Estimation of angular velocity and acceleration from shaft encoder measurements (2003)

The output of a shaft encoder is basically a quantized measurement of the shaft angle. One method of angular velocity and acceleration measurement is by finite difference of angle measurements (net pulse counts) at regular time samples. It is shown that these estimates become significantly degraded as sampling rates increase. Kalman filtering of the angle measurements, based on some model of signal generation, is proposed. Asymptotic analysis of constant sampling rate as the intersample time tends to zero shows that the error variances tend to zero, but at decreasing rates for the angle, velocity, and acceleration errors. The analysis also suggests the use of multiple-integrator systems to model the angle signal.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
Cutting Edge: Precursor Frequency Affects the Helper Dependence of Cytotoxic T Cells (2002)

Generation of CTL immunity often depends on the availability of CD4 T cell help. In this report, we show that CTL responses induced by cross-priming can be converted from CD4-dependent to CD4-independent by increasing the frequency of CTL precursors. In the absence of CD4 T cells, high numbers of CTL precursors were able to expand in number and become effector CTL. The ability of high frequencies of CD8 T cells to override help was not due to their ability to signal CD40 via expression of CD154. These findings suggest that when precursor frequencies are high, priming of CD8 T cell responses may not require CD4 T cell help.
Interoperability And Performance Analysis Of Iec61850 Based Substation Protection System (2013)

Since IEC61850 substation communication standard represents the trend to develop new generations of Substation Automation System (SAS), many IED manufacturers pursue this technique and apply for KEMA. In order to put on the market to meet customer demand as fast as possible, manufacturers often apply their products only for basic environment standard certification but claim to conform to IEC61850 certification. Since verification institutes generally perform verification tests only on specific IEDs of the manufacturers, the interoperability between all certified IEDs cannot be guaranteed. Therefore the interoperability between IEDs from different manufacturers needs to be tested. Based upon the above reasons, this study applies the definitions of the information models, communication service, GOOSE functionality and Substation Configuration Language (SCL) of the IEC61850 to build the concept of communication protocols, and build the test environment. The procedures of the test of the data collection and exchange of the P2P communication mode and Client / Server communication mode in IEC61850 are outlined as follows. First, test the IED GOOSE messages communication capability from different manufacturers. Second, collect IED data from each IED with SCADA system and use HMI to display the SCADA platform. Finally, problems generally encountered in the test procedure are summarized.
Effects of advertised receive buffer size and timer granularity on TCP performance over erroneous links in a LEO satellite network (2002)

This paper presents a preliminary investigation into the impact of TCP's advertised receive buffer size and timer granularity on TCP performance over erroneous links in a LEO satellite environment. Conducted simulations include over 200 different combinations of TCP flavor, advertised receive buffer size, timer granularity, and bit error rate. Results show that TCP can only approximate the variable propagation delay for unsaturated links and that the minimum timer granularity which prevents a premature expiration of the RTO depends on the advertised receive buffer size. Low BERs do not influence TCP's capability to track the variable propagation delay in contrast to high BERs. Final results indicate that the relative performance degradation of TCP over erroneous links does not depend on the ability to estimate the variable propagation delay.
Validity and Reliability of Malay Version of the Job Content Questionnaire among Public Hospital Female Nurses in Malaysia (2015)

The M-JCQ is a reliable and valid instrument to measure psychosocial and physical stressors in the workplace of public hospital nurses in Malaysia.
A channel-adaptive and throughput-efficient scheduling scheme in voice/data DS-CDMA networks with constrained transmission power (2004)

In this paper, we study the throughput optimization of data traffic for a power-constrained voice/data CDMA system by the scheduling of the data users. It is found that under a given received power budget and the constraints of transmission powers, the throughput of data traffic is maximized by selecting simultaneous data users and allocating powers according to the descending order of their received power capabilities, which is defined as the product between the transmission power limit and the channel gain. Based on this principle, a novel dynamic and channel adaptive scheduling is proposed to enhance the throughput performance of data traffic. The validity of the proposed scheme and its robustness to channel estimation error is verified by comparing with the conventional fair-sharing scheme and round-robin scheme via power simulation.
Chromatin structure of the EGFR gene suggests a role for intron 1 sequences in its regulation in breast cancer cells (1993)

The chromatin structure of the epidermal growth factor receptor gene (EGFR) has been analyzed in several human breast cancer cell lines exhibiting a wide range of EGFR expression. Using DNase I, structural differences were identified in the promoter, first exon, and intron 1 of the EGFR gene that correlate with its expression. Specifically, a DNase I hypersensitive site (DH site) around the exon 1/intron 1 boundary occurred preferentially in estrogen receptor positive breast cancer cell lines with low levels of EGFR expression, while a group of DH sites in intron 1 were observed in estrogen receptor negative, high EGFR expressors. Additionally, a region in the promoter was sensitive to DNase I in all breast cancer cells expressing EGFR, but showed differences in both the level of nuclease sensitivity and the extent of the area that was susceptible. Fine mapping by native genomic blotting revealed the presence of multiple protein footprints in both the promoter and first intron of the EGFR gene in MDA-MB-468 cells, a breast cancer cell line that overexpresses the EGFR gene. The appearance of DH sites in intron 1 associated with high levels of EGFR expression suggests that these regions of the gene contain potential enhancer elements, while the absence of a DH site at the exon 1/intron 1 boundary when the gene is up-regulated suggests the action of a repressor that may block transcriptional elongation.
Lecithin (2014)

Abstract The name lecithin was first used to describe a sticky, orange colored phosphorus and nitrogen‐containing material, initially isolated from egg yolk. Lecithin and other phospholipids are of universal occurrence in living organisms. Industrial lecithin from various sources are utilized. The main sources include vegetable oils and animal tissues. However egg lecithin and in particular soy lecithin are the most important. Crude soy lecithin is obtained by the degumming process of soy oil. There are six commercial grades of lecithin: crude; fluidized; highly filtered; compound; chemically modified; and fractionated. Soybeans are listed by the U.S. FDA as one of the major food allergens. However, soy lecithin does not contain sufficient soy protein to provoke allergic reactions. Soy lecithin has many uses in foods, beverages, health and nutrition products, cosmetics, and industrial products.
Synergistic Interplay between Curcumin and Polyphenol-Rich Foods in the Mediterranean Diet: Therapeutic Prospects for Neurofibromatosis 1 Patients (2017)

Neurofibromas are the hallmark lesions in Neurofibromatosis 1 (NF1); these tumors are classified as cutaneous, subcutaneous and plexiform. In contrast to cutaneous and subcutaneous neurofibromas, plexiform neurofibromas can grow quickly and progress to malignancy. Curcumin, a turmeric-derived polyphenol, has been shown to interact with several molecular targets implicated in carcinogenesis. Here, we describe the impact of different dietary patterns, namely Mediterranean diet (MedDiet) compared to the Western diet (WesDiet), both with or without curcumin, on NF1 patients' health. After six months, patients adopting a traditional MedDiet enriched with 1200 mg curcumin per day (MedDietCurcumin) presented a significant reduction in the number and volume of cutaneous neurofibromas; these results were confirmed in subsequent evaluations. Notably, in one patient, a large cranial plexiform neurofibroma exhibited a reduction in volume (28%) confirmed by Magnetic Resonance Imaging. Conversely, neither unenriched MedDiet nor WesDiet enriched with curcumin exhibited any significant positive effect. We hypothesize that the combination of a polyphenol-rich Mediterranean diet and curcumin was responsible for the beneficial effect observed on NF1. This is, to the best of our knowledge, the first experience with curcumin supplementation in NF1 patients. Our report suggests that an integrated nutritional approach may effectively aid in the management of NF1.
Carbohydrate C-Nitroalcohols: 6-Nitro-6-desoxy-D-sorbitol: A Convenient Source of L-Gulose (1945)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCarbohydrate C-Nitroalcohols: 6-Nitro-6-desoxy-D-sorbitol: A Convenient Source of L-GuloseJohn C. Sowden and Hermann O. L. FischerCite this: J. Am. Chem. Soc. 1945, 67, 10, 1713–1715Publication Date (Print):October 1, 1945Publication History Published online1 May 2002Published inissue 1 October 1945https://pubs.acs.org/doi/10.1021/ja01226a029https://doi.org/10.1021/ja01226a029research-articleACS PublicationsRequest reuse permissionsArticle Views135Altmetric-Citations25LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Cyclin-dependent kinase control of centrosome duplication (1999)

Centrosomes nucleate microtubules and duplicate once per cell cycle. This duplication and subsequent segregation in mitosis results in maintenance of the one centrosome/cell ratio. Centrosome duplication occurs during the G1/S transition in somatic cells and must be coupled to the events of the nuclear cell cycle; failure to coordinate duplication and mitosis results in abnormal numbers of centrosomes and aberrant mitoses. Using both in vivo and in vitro assays, we show that centrosome duplication in Xenopus laevis embryos requires cyclin/cdk2 kinase activity. Injection of the cdk (cyclin-dependent kinase) inhibitor p21 into one blastomere of a dividing embryo blocks centrosome duplication in that blastomere; the related cdk inhibitor p27 has a similar effect. An in vitro system using Xenopus extracts carries out separation of the paired centrioles within the centrosome. This centriole separation activity is dependent on cyclin/cdk2 activity; depletion of either cdk2 or of the two activating cyclins, cyclin A and cyclin E, eliminates centriole separation activity. In addition, centriole separation is inhibited by the mitotic state, suggesting a mechanism of linking the cell cycle to periodic duplication of the centrosome.