gebhart/patrepeval huggingface dataset:
Hydroxyl Group Catalysis. II. The Reactivity of the Hydroxyl Group of Serine. The Nucleophilicity of Alcohols and the Ease of Hydrolysis of Their Acetyl Esters as Related to Their pKa'<sup>*</sup> (1962)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHydroxyl Group Catalysis. II. The Reactivity of the Hydroxyl Group of Serine. The Nucleophilicity of Alcohols and the Ease of Hydrolysis of Their Acetyl Esters as Related to Their pKa'*Thomas C. Bruice, Thomas H. Fife, J. J. Bruno, and Nancy E. BrandonCite this: Biochemistry 1962, 1, 1, 7–12Publication Date (Print):January 1, 1962Publication History Published online1 May 2002Published inissue 1 January 1962https://doi.org/10.1021/bi00907a002RIGHTS & PERMISSIONSArticle Views827Altmetric-Citations66LEARN 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 InReddit PDF (655 KB) Get e-Alerts Get e-Alerts
Two-Timescale Radio Resource Management for Heterogeneous Networks with Flexible Backhaul (2015)

In this paper, we focus on the problem of hierarchical cross-layer dynamic resource allocation for heterogeneous networks with flexible backhaul. We formulate the radio resource management problem as a two timescale non-convex stochastic optimisation problem which jointly optimizes flow control, routing control, interference mitigation and link scheduling in order to maximize a generic network utility. We propose an iterative hierarchical control structure where the long-term controls are adaptive to large scale fading and the short-term control is adaptive to the local CSI within a pico or macro BS, to find the optimal solution. The proposed solution benefits from low complexity and requires low signalling and message passing among different nodes, which makes it scalable. Moreover, due to the proposed two-timescale hierarchical design, it is robust to the backhaul signalling latency as well. Simulation results demonstrate the significant performance gain of the proposed solution over various baselines.
The Chemistry, Photophysics and Photosensitizing Properties of Phthalocyanines (2007)

Phthalocyanines (Pcs) and naphthalocyanines (Ncs) are being extensively studied as photosensitizers for photodynamic therapy (PDT) of cancer. They strongly absorb clinically useful red light, with maxima around 670 nm and 770 nm respectively. Chelated with appropriate diamagnetic metal ions, they exhibit high triplet yields and long triplet lifetimes. Energy transfer from the triplet dye to ground-state oxygen to yield singlet oxygen appears to be the main photosensitizing pathway in biological systems. Underivatized Pcs and Ncs can be incorporated in liposomes for in vivo administration. Sulphonation renders the dyes water soluble but also enhances dimerization to yield photochemically inactive aggregates. Tumour retention and cell membrane penetration of the dyes are strongly affected by the polarity of the macrocycle as well as the nature of the central metal ion and axial ligands. Among the sulphonated dyes, amphiphilic mono- and disulphonated derivatives exhibit particularly good cell membrane-penetrating properties, although the more highly sulphonated dyes show better tumour retention in vivo. At least in vitro, Pc dyes are more photoactive than the corresponding Nc dyes, which probably reflects the lower photostability of the latter.
Pharmacological <i>in vivo</i> test to evaluate the bioavailability of some St John's Wort innovative oral preparations (2008)

In this study, the optimisation of biopharmaceutical properties of a dried commercial extract of St John's Wort were evaluated employing the in vivo forced swimming test (FST). Three new dosage forms containing beta-cyclodextrin and surfactants (SDS, ASC8) were compared in the FST with the commercial extract. The commercial extract showed antidepressant activity in mice after 60 min at a dosage of 100 mg/kg. The same antidepressant activity appeared in 30 min with a micellar solution of SDS containing the same quantity of extract (100 mg/kg), while with micelles of ASC8 the effect appeared at 15 min and with a dosage of 30 mg/kg. In the case of beta-cyclodextrin the best results were obtained at 30 min, administering 60 mg/kg of the extract. Finally, the influence of the formulations on the water solubility of the constituents of the extract is reported. The tensides dramatically enhanced solubility, in particular that of the more lipophilic compounds, in the case of beta-cyclodextrin this effect was very pronounced for flavonoids and biapigenin, lower for hypericins and practically insignificant for hyperforins.
Topology Optimization for Additive Manufacturing as an Enabler for Light Weight Flight Hardware (2018)

Three case studies utilizing topology optimization and Additive Manufacturing for the development of space flight hardware are described. The Additive Manufacturing (AM) modality that was used in this work is powder bed laser based fusion. The case studies correspond to the redesign and manufacture of two heritage parts for a Surrey Satellite Technology LTD (SSTL) Technology Demonstrator Space Mission that are currently functioning in orbit (case studies 1 and 2), and a system of five components for the SpaceIL’s lunar launch vehicle planned for launch in the near future (case study 3). In each case, the nominal or heritage part has undergone topology optimization, incorporating the AM manufacturing constraints that include: minimization of support structures, ability to remove unsintered powder, and minimization of heat transfer jumps that will cause artifact warpage. To this end the topology optimization exercise must be coupled to the Additive Manufacturing build direction, and steps are incorporated to integrate the AM constraints. After design verification by successfully passing a Finite Element Analysis routine, the components have been fabricated and the AM artifacts and in-process testing coupons have undergone verification and qualification testing in order to deliver structural components that are suitable for their respective missions.
Brain structural deficits and working memory fMRI dysfunction in young adults who were diagnosed with ADHD in adolescence (2015)

When adolescents with ADHD enter adulthood, some no longer meet disorder diagnostic criteria but it is unknown if biological and cognitive abnorma lities persist. We tested the hypothesis that people diagnosed with ADHD during adolescence present residual brain abnormalities both in brain structure and in working memory brain function. 83 young adults (aged 20-24 years) from the Northern Finland 1986 Birth Cohort were classified as diagnosed with ADHD in adolescence (adolescence ADHD, n = 49) or a control group (n = 34). Only one patient had received medication for ADHD. T1-weighted brain scans were acquired and processed in a voxel-based analysis using permutation-based statistics. A sub-sample of both groups (ADHD, n = 21; controls n = 23) also performed a Sternberg working memory task whilst acquiring fMRI data. Areas of structural difference were used as a region of interest to evaluate the implications that structural abnormalities found in the ADHD group might have on working memory function. There was lower grey matter volume bilaterally in adolescence ADHD participants in the caudate (p < 0.05 FWE corrected across the whole brain) at age 20-24. Working memory was poorer in adolescence ADHD participants, with associated failure to show normal load-dependent caudate activation. Young adults diagnosed with ADHD in adolescence have structural and functional deficits in the caudate associated with abnormal working memory function. These findings are not secondary to stimulant treatment, and emphasise the importance of taking a wider perspective on ADHD outcomes than simply whether or not a particular patient meets diagnostic criteria at any given point in time.
Production of cumulative jets by ablatively-driven implosion of hollow cones and wedges (2008)

Cumulative plasma jets formed by hollow cones imploded via laser ablation of their outer surfaces were observed. The velocity, shape, and density of the jets are measured with monochromatic 0.65keV x-ray imaging. Depending on cone geometry, cumulative jets with ion density ∼2×1020cm−3 and propagation velocities &gt;10km∕s are formed. Similar results are observed when jets are formed by imploding wedges. Such jets can be used to simulate hydrodynamics of astrophysical jets interacting with stellar or interstellar matter.
Glycolic Acid Peels Compared to Microdermabrasion: A Right-Left Controlled Trial of Efficacy and Patient Satisfaction (2002)

In this study, patients appeared to prefer low-strength glycolic acid peels to low-intensity microdermabrasion for facial rejuvenation. Differences in patient satisfaction were subtle and may be technique dependent.
Performance Characterization of Distributed Programs (1984)

Writing distributed programs is difficult for at least two reasons. The first reason is that distributed computing environments present new problems caused by asynchrony, independent time bases, and communications delays. The second reason is that there is a lack of tools available to help the programmer understand the program he/she has written. The tools we use for single machine environments do not easily generalize to a distributed environment. There has been only limited success with previous systems that have tried to help the programmer in developing, debugging, and measuring distributed programs. <p> To better understand distributed programs we have: specified a model for distributed computations, developed a measurement methodology from this model, constructed tools to implement the measurements, and developed data analysis techniques to obtain useful results from the measurements. The most important feature of the models, methodology, and tools is consistency between the programmer's view, the computation model, the measurement methodology, and the analysis. <p> This consistency has resulted in several benefits. The first is a simplicity of structure throughout the measurement and analysis tools. The second benefit is the ease of obtaining useful information about a program's behavior. <p> The model of distributed programs defines the two basic actions of a program to be computation and communication. Our research focuses on the communications performed by a program. The measurement model is based on the monitoring of communications between the parts of a program. Given our definition of a program, monitoring communications completely encapsulates the behavior of a computation. From the measurement model, we have constructed tools to measure distributed programs for two working operating systems, UNIX and DEMOS/MP. These measurement tools provide data on the interactions between the parts of a distributed program. <p> We have developed a number of analysis techniques to provide information from the data collected. We can report communications statistics on message counts, queue lengths, and message waiting times. We can perform more complex analyses, such as measuring the amount of parallelism in the execution of a distributed program. The analyses also include detecting paths of causality through the parts of a distributed program. The measurement tools and analyses can be structured so that results can be fed back into the operating system to help with scheduling decisions
Preparation and Mechanical Property of Mg-Zn-Y Alloy with a Long Period Ordered Phase (2010)

The composition dependence of yield strength and elongation of the Mg-Zn-Y ternary alloy system were investigated. Yield strength was found to increase with the increasing Zn and Y contents, while elongation decreased in Zn- and Y- rich- regions in the system. The composition ratio of Zn to Y, both of which shows large elongation and comparatively high yield strength, was 1:1 in the Mg-rich region of the alloy system. Mg98Zn1Y1, Mg96Zn2Y2, and Mg94Zn3Y3 (at.%) cast alloys exhibited yield strength of 107, 129, and 173 MPa, and elongations of 17, 8, and 12 %, respectively. These alloys consist of Mg-, LPO-, and Mg3Zn3Y2- phases. We also prepared Mg-Zn-Y alloy sheets by hot rolling using cast alloys, and we investigated their microstructure and mechanical properties. The Mg98Zn1Y1, Mg96Zn2Y2, and Mg94Zn3Y3, alloy sheets exhibited yield strength of 276, 319, and 379 MPa, and elongations of 12, 11, and 8 %, respectively. After annealing at 673 K for 3 h, large elongations above 20 % were achieved both of the Mg98Zn1Y1 and Mg96Zn2Y2 alloy sheets.
Towards preparative-scale, biocatalytic alkene reductions (2010)

Simple strategies for using alkene reductase enzymes to produce gram-scale quantities of both (R)- and (S)-citronellal have been developed. The methodology is easily accessible to non-specialist laboratories, allowing alkene reductases to be added to the toolbox of routine synthetic transformations.
The flavoprotein-catalyzed reduction of aliphatic nitro-compounds represents a biocatalytic equivalent to the Nef-reaction (2010)

The bioreduction of aliphatic sec-nitro compounds catalyzed by purified flavoproteins from the old-yellow-enzyme family unexpectedly furnished the corresponding carbonyl compounds instead of the expected amines and thus represents a biocatalytic equivalent to the Nef-reaction. The pathway was shown to proceed via initial reduction of the nitro-group to yield the nitroso-derivative, which spontaneously tautomerized to yield the more stable oxime, which was enzymatically reduced in a second step to furnish a hydrolytically unstable imine-species, which spontaneously hydrolyzed to finally give a carbonyl compound and ammonia.
Overexpression of the granulocyte colony-stimulating factor gene leads to osteoporosis in mice. (1996)

Although granulocyte colony-stimulating factor (G-CSF) was originally isolated as an activity for the growth and differentiation of cells in granulocytic lineage, it has been gradually accepted that G-CSF may have a function on a wide variety of cells besides granulocytes. To elucidate the function of G-CSF on bone cells in vivo, we examined the bone tissue of transgenic mice that overexpress G-CSF. Transgenic mice express human G-CSF at an elevated level (1041 +/- 242 pg/ml in sera) under the direction of SRalpha promoter. We performed radiographic, routine histologic, and histomorphometric analyses of the bone tissue and serum biochemical assay. Nontransgenic littermates were examined as age-matched, wild-type controls in all experiments. Radiographic analysis revealed cortical thinning accompanied by enlarged bone marrow cavities in both vertebral bodies and long bones. Histologically, a decreased number and thickness of trabecular bones and cortical thinning were observed in lumber vertebrae as well as in femur specimens. The enlarged bone marrow cavities exhibited an increased number of mature neutrophilic granulocytes without apparent changes in other types of cells. The static and dynamic parameters reflecting bone resorption were found to be significantly increased in the transgenic mice. By contrast, no significant differences were detected in the parameters reflecting bone formation. Transgenic mice and littermate controls had similar serum calcium, phosphorous, and alkaline phosphatase levels. However, the serum osteocalcin level was significantly higher in transgenic mice. These findings indicate that G-CSF-expressing transgenic mice developed osteoporosis because of increased osteoclastic activity. Collectively, G-CSF could have a negative influence on bone homeostasis in vivo.
Elimination of the feed-through effect in vortex flow transistors (1991)

The capacitive feed-through effect in a VFT (vortex flow transistor) has been identified as a major limiting factor for high-frequency distributed amplifier applications. Two techniques to eliminate this effect are proposed and discussed. They are the use of a balanced controlled VFT and the use of a modified super current injection transistor. The balanced controlled configuration consists of a pair of Josephson junctions driven by control lines excited by push-pull. The simulations show more than 100-dB improvement in S12 over a single-ended device up to 175 GHz. The modified superconducting current injection transistor is a current controlled current source allowing the output line to be fed against ground. Hence, capacitive feed-through effects are greatly reduced. Device layouts and fabrication techniques are discussed.
New Azasterols against <i>Trypanosoma brucei</i> : Role of 24-Sterol Methyltransferase in Inhibitor Action (2006)

A series of azasterol derivatives, designed as potential inhibitors of the Delta(24)-sterol methyltransferase enzyme (24-SMT), were synthesized and evaluated for their activities against parasitic protozoa. Values in the nanomolar range were obtained for 50% effective dose against the Trypanosoma brucei subsp. rhodesiense bloodstream form cultured in vitro. In order to investigate the mode of action, Trypanosoma brucei subsp. brucei 24-SMT was cloned and overexpressed and compounds were assayed for inhibitory activity. None of the inhibitors tested appeared to be active against the enzyme. Sterol composition analysis showed that only cholestane type sterols are present in membranes of bloodstream forms while ergosterol is a major component of procyclic sterol extracts. Interestingly, Northern blot analysis showed the presence of 24-SMT mRNA in both the procyclic and the bloodstream forms of the parasite, although levels of mRNA were threefold lower in the latter. Likewise, Western blot analysis and activity determinations evidenced the existence of active enzyme in both forms of the parasite. We conclude that the designed compounds act at sites other than 24-SMT in Trypanosoma brucei.
Kinetics of Enzyme-Catalyzed Alcoholysis of Soybean Oil in n-Hexane (2005)

This work investigated the production of fatty acid ethyl esters (FAEEs) from soybean oil using n-hexane as solvent and two commercial lipases as catalysts, Novozym 435 and Lipozyme IM. A Taguchi experimental design was adopted considering the variables temperature (35–65°C), addition of water (0–10 wt/wt%), enzyme (5–20 wt/wt%) concentration, and oil-to-ethanol molar ratio (1:3–1:10). It is shown that complete conversion in FAEE is achieved for some experimental conditions. The effects of process variables on reaction conversion and kinetics of the enzymatic reactions are presented for all experimental conditions investigated in the factorial design.
Synthesis of [2,3-b]thieno- and furoquinoxalines by the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si1.gif" overflow="scroll"><mml:mrow><mml:msubsup><mml:mtext>S</mml:mtext><mml:mtext>N</mml:mtext><mml:mtext>H</mml:mtext></mml:msubsup></mml:mrow></mml:math> and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" altimg="si2.gif" overflow="scroll"><mml:mrow><mml:msubsup><mml:mtext>S</mml:mtext><mml:mtext>N</mml:mtext><mml:mrow><mml:mi>i</mml:mi><mml:mi>p</mml:mi><mml:mi>s</mml:mi><mml:mi>o</mml:mi></mml:mrow></mml:msubsup></mml:mrow></mml:math> reactions of 2-substituted quinoxalines with acetophenones (2006)

The treatment of quinoxalin-2-one with acetophenones in the presence of boron trifluoride gives 3-(2-hydroxy-2-R-vinyl)-quinoxalin-2-ones, which can be transformed into [2,3-b]thienoquinoxalines by reactions with P2S5.
Sublinear Zero-Knowledge Arguments for RAM Programs. (2017)

We describe a new succinct zero-knowledge argument protocol with the following properties. The prover commits to a large data-set M, and can thereafter prove many statements of the form \(\exists w : \mathcal {R}_i(M,w)=1\), where \(\mathcal {R}_i\) is a public function. The protocol is succinct in the sense that the cost for the verifier (in computation & communication) does not depend on |M|, not even in any initialization phase In each proof, the computation/communication cost for both the prover and the verifier is proportional only to the running time of an oblivious RAM program implementing \(\mathcal {R}_i\) (in particular, this can be sublinear in |M|). The only costs that scale with |M| are the computational costs of the prover in a one-time initial commitment to M.
Registration-based segmentation of murine 4D cardiac micro-CT data using symmetric normalization (2012)

Micro-CT can play an important role in preclinical studies of cardiovascular disease because of its high spatial and temporal resolution. Quantitative analysis of 4D cardiac images requires segmentation of the cardiac chambers at each time point, an extremely time consuming process if done manually. To improve throughput this study proposes a pipeline for registration-based segmentation and functional analysis of 4D cardiac micro-CT data in the mouse. Following optimization and validation using simulations, the pipeline was applied to in vivo cardiac micro-CT data corresponding to ten cardiac phases acquired in C57BL/6 mice (n = 5). After edge-preserving smoothing with a novel adaptation of 4D bilateral filtration, one phase within each cardiac sequence was manually segmented. Deformable registration was used to propagate these labels to all other cardiac phases for segmentation. The volumes of each cardiac chamber were calculated and used to derive stroke volume, ejection fraction, cardiac output, and cardiac index. Dice coefficients and volume accuracies were used to compare manual segmentations of two additional phases with their corresponding propagated labels. Both measures were, on average, >0.90 for the left ventricle and >0.80 for the myocardium, the right ventricle, and the right atrium, consistent with trends in inter- and intra-segmenter variability. Segmentation of the left atrium was less reliable. On average, the functional metrics of interest were underestimated by 6.76% or more due to systematic label propagation errors around atrioventricular valves; however, execution of the pipeline was 80% faster than performing analogous manual segmentation of each phase.
Received Signal Strength Models for Narrowband Radios (2017)

The advancements in wireless communication technologies have enabled new sensing possibilities where the channel measurements of the radio are used for inferring physical changes in the surrounding environment. Relating the channel measurements to the location and actions of people has been of particular interest due to the wide range of application opportunities enabled by such a sensing capability. As an example, the low-amplitude received signal measurements of low-cost wireless communication systems have been used to detect the presence of a person, to locate and track them, identify gestures and activities of the person, and even monitor their vital signs. This chapter aims to give a deep insight on how people influence radio signals, how these effects are observed at the receiver antenna, and how the measurement system impacts the recorded measurements. These topics are presented to shed light on the relation between the location of people and signal strength measurements of narrowband radios.